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* [RFC PATCH v3 00/11] qapi: net: add unix socket type support to netdev backend
@ 2022-06-20 10:18 Laurent Vivier
  2022-06-20 10:18 ` [RFC PATCH v3 01/11] net: introduce convert_host_port() Laurent Vivier
                   ` (11 more replies)
  0 siblings, 12 replies; 28+ messages in thread
From: Laurent Vivier @ 2022-06-20 10:18 UTC (permalink / raw)
  To: qemu-devel
  Cc: Markus Armbruster, Eric Blake, Dr. David Alan Gilbert,
	Paolo Bonzini, Daniel P. Berrangé,
	Jason Wang, Laurent Vivier, Ralph Schmieder, Stefano Brivio

"-netdev socket" only supports inet sockets.

It's not a complex task to add support for unix sockets, but
the socket netdev parameters are not defined to manage well unix
socket parameters.

As discussed in:

  "socket.c added support for unix domain socket datagram transport"
  https://lore.kernel.org/qemu-devel/1C0E1BC5-904F-46B0-8044-68E43E67BE60@gmail.com/

This series adds support of unix socket type using SocketAddress QAPI structure.

Two new netdev backends, "stream" and "dgram" are added, that are barely a copy of "socket"
backend but they use the SocketAddress QAPI to provide socket parameters.
And then they also implement unix sockets (TCP and UDP).

Some examples of CLI syntax:

  for TCP:

  -netdev stream,id=socket0,addr.type=inet,addr.host=localhost,addr.port=1234
  -netdev stream,id=socket0,server=off,addr.type=inet,addr.host=localhost,addr.port=1234

  -netdev dgram,id=socket0,\
          local.type=inet,local.host=localhost,local.port=1234,\
          remote.type=inet,remote.host=localhost,remote.port=1235

  for UNIX:

  -netdev stream,id=socket0,addr.type=unix,addr.path=/tmp/qemu0
  -netdev stream,id=socket0,server=off,addr.type=unix,addr.path=/tmp/qemu0

  -netdev dgram,id=socket0,\
          local.type=unix,local.path=/tmp/qemu0,\
          remote.type=unix,remote.path=/tmp/qemu1

  for FD:

  -netdev stream,id=socket0,addr.type=fd,addr.str=4
  -netdev stream,id=socket0,server=off,addr.type=fd,addr.str=5

  -netdev dgram,id=socket0,local.type=fd,addr.str=4

v3:
  - remove support of "-net" for dgram and stream. They are only
    supported with "-netdev" option.
  - use &error_fatal directly in net_client_inits()
  - update qemu-options.hx
  - move to QIO for stream socket

v2:
  - use "stream" and "dgram" rather than "socket-ng,mode=stream"
    and ""socket-ng,mode=dgram"
  - extract code to bypass qemu_opts_parse_noisily() to
    a new patch
  - do not ignore EINVAL (Stefano)
  - fix "-net" option

CC: Ralph Schmieder <ralph.schmieder@gmail.com>
CC: Stefano Brivio <sbrivio@redhat.com>
CC: Daniel P. Berrangé <berrange@redhat.com>
CC: Markus Armbruster <armbru@redhat.com>

Laurent Vivier (10):
  net: introduce convert_host_port()
  net: remove the @errp argument of net_client_inits()
  qapi: net: introduce a way to bypass qemu_opts_parse_noisily()
  qapi: net: add stream and dgram netdevs
  net: stream: add unix socket
  net: dgram: make dgram_dst generic
  net: dgram: move mcast specific code from net_socket_fd_init_dgram()
  net: dgram: add unix socket
  qemu-sockets: introduce socket_uri()
  net: stream: move to QIO

Stefano Brivio (1):
  net: stream: Don't ignore EINVAL on netdev socket connection

 hmp-commands.hx        |   2 +-
 include/net/net.h      |   3 +-
 include/qemu/sockets.h |   4 +-
 monitor/hmp-cmds.c     |  23 +-
 net/clients.h          |   6 +
 net/dgram.c            | 706 +++++++++++++++++++++++++++++++++++++++++
 net/hub.c              |   2 +
 net/meson.build        |   2 +
 net/net.c              | 149 ++++++---
 net/stream.c           | 371 ++++++++++++++++++++++
 qapi/net.json          |  40 ++-
 qemu-options.hx        |  12 +
 softmmu/vl.c           |   5 +-
 util/qemu-sockets.c    |  20 ++
 14 files changed, 1277 insertions(+), 68 deletions(-)
 create mode 100644 net/dgram.c
 create mode 100644 net/stream.c

-- 
2.36.1



^ permalink raw reply	[flat|nested] 28+ messages in thread

* [RFC PATCH v3 01/11] net: introduce convert_host_port()
  2022-06-20 10:18 [RFC PATCH v3 00/11] qapi: net: add unix socket type support to netdev backend Laurent Vivier
@ 2022-06-20 10:18 ` Laurent Vivier
  2022-06-20 10:18 ` [RFC PATCH v3 02/11] net: remove the @errp argument of net_client_inits() Laurent Vivier
                   ` (10 subsequent siblings)
  11 siblings, 0 replies; 28+ messages in thread
From: Laurent Vivier @ 2022-06-20 10:18 UTC (permalink / raw)
  To: qemu-devel
  Cc: Markus Armbruster, Eric Blake, Dr. David Alan Gilbert,
	Paolo Bonzini, Daniel P. Berrangé,
	Jason Wang, Laurent Vivier, Stefano Brivio

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
---
 include/qemu/sockets.h |  2 ++
 net/net.c              | 62 ++++++++++++++++++++++--------------------
 2 files changed, 34 insertions(+), 30 deletions(-)

diff --git a/include/qemu/sockets.h b/include/qemu/sockets.h
index 038faa157f59..47194b9732f8 100644
--- a/include/qemu/sockets.h
+++ b/include/qemu/sockets.h
@@ -47,6 +47,8 @@ void socket_listen_cleanup(int fd, Error **errp);
 int socket_dgram(SocketAddress *remote, SocketAddress *local, Error **errp);
 
 /* Old, ipv4 only bits.  Don't use for new code. */
+int convert_host_port(struct sockaddr_in *saddr, const char *host,
+                      const char *port, Error **errp);
 int parse_host_port(struct sockaddr_in *saddr, const char *str,
                     Error **errp);
 int socket_init(void);
diff --git a/net/net.c b/net/net.c
index 2db160e0634d..d2288bd3a929 100644
--- a/net/net.c
+++ b/net/net.c
@@ -66,55 +66,57 @@ static QTAILQ_HEAD(, NetClientState) net_clients;
 /***********************************************************/
 /* network device redirectors */
 
-int parse_host_port(struct sockaddr_in *saddr, const char *str,
-                    Error **errp)
+int convert_host_port(struct sockaddr_in *saddr, const char *host,
+                      const char *port, Error **errp)
 {
-    gchar **substrings;
     struct hostent *he;
-    const char *addr, *p, *r;
-    int port, ret = 0;
+    const char *r;
+    long p;
 
     memset(saddr, 0, sizeof(*saddr));
 
-    substrings = g_strsplit(str, ":", 2);
-    if (!substrings || !substrings[0] || !substrings[1]) {
-        error_setg(errp, "host address '%s' doesn't contain ':' "
-                   "separating host from port", str);
-        ret = -1;
-        goto out;
-    }
-
-    addr = substrings[0];
-    p = substrings[1];
-
     saddr->sin_family = AF_INET;
-    if (addr[0] == '\0') {
+    if (host[0] == '\0') {
         saddr->sin_addr.s_addr = 0;
     } else {
-        if (qemu_isdigit(addr[0])) {
-            if (!inet_aton(addr, &saddr->sin_addr)) {
+        if (qemu_isdigit(host[0])) {
+            if (!inet_aton(host, &saddr->sin_addr)) {
                 error_setg(errp, "host address '%s' is not a valid "
-                           "IPv4 address", addr);
-                ret = -1;
-                goto out;
+                           "IPv4 address", host);
+                return -1;
             }
         } else {
-            he = gethostbyname(addr);
+            he = gethostbyname(host);
             if (he == NULL) {
-                error_setg(errp, "can't resolve host address '%s'", addr);
-                ret = -1;
-                goto out;
+                error_setg(errp, "can't resolve host address '%s'", host);
+                return -1;
             }
             saddr->sin_addr = *(struct in_addr *)he->h_addr;
         }
     }
-    port = strtol(p, (char **)&r, 0);
-    if (r == p) {
-        error_setg(errp, "port number '%s' is invalid", p);
+    if (qemu_strtol(port, &r, 0, &p) != 0) {
+        error_setg(errp, "port number '%s' is invalid", port);
+        return -1;
+    }
+    saddr->sin_port = htons(p);
+    return 0;
+}
+
+int parse_host_port(struct sockaddr_in *saddr, const char *str,
+                    Error **errp)
+{
+    gchar **substrings;
+    int ret;
+
+    substrings = g_strsplit(str, ":", 2);
+    if (!substrings || !substrings[0] || !substrings[1]) {
+        error_setg(errp, "host address '%s' doesn't contain ':' "
+                   "separating host from port", str);
         ret = -1;
         goto out;
     }
-    saddr->sin_port = htons(port);
+
+    ret = convert_host_port(saddr, substrings[0], substrings[1], errp);
 
 out:
     g_strfreev(substrings);
-- 
2.36.1



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* [RFC PATCH v3 02/11] net: remove the @errp argument of net_client_inits()
  2022-06-20 10:18 [RFC PATCH v3 00/11] qapi: net: add unix socket type support to netdev backend Laurent Vivier
  2022-06-20 10:18 ` [RFC PATCH v3 01/11] net: introduce convert_host_port() Laurent Vivier
@ 2022-06-20 10:18 ` Laurent Vivier
  2022-06-20 11:39   ` Markus Armbruster
  2022-06-20 10:18 ` [RFC PATCH v3 03/11] qapi: net: introduce a way to bypass qemu_opts_parse_noisily() Laurent Vivier
                   ` (9 subsequent siblings)
  11 siblings, 1 reply; 28+ messages in thread
From: Laurent Vivier @ 2022-06-20 10:18 UTC (permalink / raw)
  To: qemu-devel
  Cc: Markus Armbruster, Eric Blake, Dr. David Alan Gilbert,
	Paolo Bonzini, Daniel P. Berrangé,
	Jason Wang, Laurent Vivier

The only caller passes &error_fatal, so use this directly in the function.

It's what we do for -blockdev, -device, and -object.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
---
 include/net/net.h |  2 +-
 net/net.c         | 20 +++++++-------------
 softmmu/vl.c      |  2 +-
 3 files changed, 9 insertions(+), 15 deletions(-)

diff --git a/include/net/net.h b/include/net/net.h
index 523136c7acba..c53c64ac18c4 100644
--- a/include/net/net.h
+++ b/include/net/net.h
@@ -216,7 +216,7 @@ extern const char *host_net_devices[];
 /* from net.c */
 int net_client_parse(QemuOptsList *opts_list, const char *str);
 void show_netdevs(void);
-int net_init_clients(Error **errp);
+void net_init_clients(void);
 void net_check_clients(void);
 void net_cleanup(void);
 void hmp_host_net_add(Monitor *mon, const QDict *qdict);
diff --git a/net/net.c b/net/net.c
index d2288bd3a929..15958f881776 100644
--- a/net/net.c
+++ b/net/net.c
@@ -1562,27 +1562,21 @@ out:
     return ret;
 }
 
-int net_init_clients(Error **errp)
+void net_init_clients(void)
 {
     net_change_state_entry =
         qemu_add_vm_change_state_handler(net_vm_change_state_handler, NULL);
 
     QTAILQ_INIT(&net_clients);
 
-    if (qemu_opts_foreach(qemu_find_opts("netdev"),
-                          net_init_netdev, NULL, errp)) {
-        return -1;
-    }
-
-    if (qemu_opts_foreach(qemu_find_opts("nic"), net_param_nic, NULL, errp)) {
-        return -1;
-    }
+    qemu_opts_foreach(qemu_find_opts("netdev"), net_init_netdev, NULL,
+                      &error_fatal);
 
-    if (qemu_opts_foreach(qemu_find_opts("net"), net_init_client, NULL, errp)) {
-        return -1;
-    }
+    qemu_opts_foreach(qemu_find_opts("nic"), net_param_nic, NULL,
+                      &error_fatal);
 
-    return 0;
+    qemu_opts_foreach(qemu_find_opts("net"), net_init_client, NULL,
+                      &error_fatal);
 }
 
 int net_client_parse(QemuOptsList *opts_list, const char *optarg)
diff --git a/softmmu/vl.c b/softmmu/vl.c
index 4c1e94b00eaa..8eed0f31c073 100644
--- a/softmmu/vl.c
+++ b/softmmu/vl.c
@@ -1925,7 +1925,7 @@ static void qemu_create_late_backends(void)
         qtest_server_init(qtest_chrdev, qtest_log, &error_fatal);
     }
 
-    net_init_clients(&error_fatal);
+    net_init_clients();
 
     object_option_foreach_add(object_create_late);
 
-- 
2.36.1



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* [RFC PATCH v3 03/11] qapi: net: introduce a way to bypass qemu_opts_parse_noisily()
  2022-06-20 10:18 [RFC PATCH v3 00/11] qapi: net: add unix socket type support to netdev backend Laurent Vivier
  2022-06-20 10:18 ` [RFC PATCH v3 01/11] net: introduce convert_host_port() Laurent Vivier
  2022-06-20 10:18 ` [RFC PATCH v3 02/11] net: remove the @errp argument of net_client_inits() Laurent Vivier
@ 2022-06-20 10:18 ` Laurent Vivier
  2022-06-20 12:43   ` Markus Armbruster
  2022-06-22  8:00   ` Markus Armbruster
  2022-06-20 10:18 ` [RFC PATCH v3 04/11] qapi: net: add stream and dgram netdevs Laurent Vivier
                   ` (8 subsequent siblings)
  11 siblings, 2 replies; 28+ messages in thread
From: Laurent Vivier @ 2022-06-20 10:18 UTC (permalink / raw)
  To: qemu-devel
  Cc: Markus Armbruster, Eric Blake, Dr. David Alan Gilbert,
	Paolo Bonzini, Daniel P. Berrangé,
	Jason Wang, Laurent Vivier

As qemu_opts_parse_noisily() flattens the QAPI structures ("type" field
of Netdev structure can collides with "type" field of SocketAddress),
we introduce a way to bypass qemu_opts_parse_noisily() and use directly
visit_type_Netdev() to parse the backend parameters.

More details from Markus:

qemu_init() passes the argument of -netdev, -nic, and -net to
net_client_parse().

net_client_parse() parses with qemu_opts_parse_noisily(), passing
QemuOptsList qemu_netdev_opts for -netdev, qemu_nic_opts for -nic, and
qemu_net_opts for -net.  Their desc[] are all empty, which means any
keys are accepted.  The result of the parse (a QemuOpts) is stored in
the QemuOptsList.

Note that QemuOpts is flat by design.  In some places, we layer non-flat
on top using dotted keys convention, but not here.

net_init_clients() iterates over the stored QemuOpts, and passes them to
net_init_netdev(), net_param_nic(), or net_init_client(), respectively.

These functions pass the QemuOpts to net_client_init().  They also do
other things with the QemuOpts, which we can ignore here.

net_client_init() uses the opts visitor to convert the (flat) QemOpts to
a (non-flat) QAPI object Netdev.  Netdev is also the argument of QMP
command netdev_add.

The opts visitor was an early attempt to support QAPI in
(QemuOpts-based) CLI.  It restricts QAPI types to a certain shape; see
commit eb7ee2cbeb "qapi: introduce OptsVisitor".

A more modern way to support QAPI is qobject_input_visitor_new_str().
It uses keyval_parse() instead of QemuOpts for KEY=VALUE,... syntax, and
it also supports JSON syntax.  The former isn't quite as expressive as
JSON, but it's a lot closer than QemuOpts + opts visitor.

This commit paves the way to use of the modern way instead.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
---
 include/net/net.h |  1 +
 net/net.c         | 60 +++++++++++++++++++++++++++++++++++++++++++++++
 softmmu/vl.c      |  3 ++-
 3 files changed, 63 insertions(+), 1 deletion(-)

diff --git a/include/net/net.h b/include/net/net.h
index c53c64ac18c4..4ae8ed480f73 100644
--- a/include/net/net.h
+++ b/include/net/net.h
@@ -214,6 +214,7 @@ extern NICInfo nd_table[MAX_NICS];
 extern const char *host_net_devices[];
 
 /* from net.c */
+int netdev_parse_modern(const char *optarg);
 int net_client_parse(QemuOptsList *opts_list, const char *str);
 void show_netdevs(void);
 void net_init_clients(void);
diff --git a/net/net.c b/net/net.c
index 15958f881776..c337d3d753fe 100644
--- a/net/net.c
+++ b/net/net.c
@@ -54,6 +54,7 @@
 #include "net/colo-compare.h"
 #include "net/filter.h"
 #include "qapi/string-output-visitor.h"
+#include "qapi/qobject-input-visitor.h"
 
 /* Net bridge is currently not supported for W32. */
 #if !defined(_WIN32)
@@ -63,6 +64,16 @@
 static VMChangeStateEntry *net_change_state_entry;
 static QTAILQ_HEAD(, NetClientState) net_clients;
 
+typedef struct NetdevQueueEntry {
+    Netdev *nd;
+    Location loc;
+    QSIMPLEQ_ENTRY(NetdevQueueEntry) entry;
+} NetdevQueueEntry;
+
+typedef QSIMPLEQ_HEAD(, NetdevQueueEntry) NetdevQueue;
+
+static NetdevQueue nd_queue = QSIMPLEQ_HEAD_INITIALIZER(nd_queue);
+
 /***********************************************************/
 /* network device redirectors */
 
@@ -1562,6 +1573,20 @@ out:
     return ret;
 }
 
+static void netdev_init_modern(void)
+{
+    while (!QSIMPLEQ_EMPTY(&nd_queue)) {
+        NetdevQueueEntry *nd = QSIMPLEQ_FIRST(&nd_queue);
+
+        QSIMPLEQ_REMOVE_HEAD(&nd_queue, entry);
+        loc_push_restore(&nd->loc);
+        net_client_init1(nd->nd, true, &error_fatal);
+        loc_pop(&nd->loc);
+        qapi_free_Netdev(nd->nd);
+        g_free(nd);
+    }
+}
+
 void net_init_clients(void)
 {
     net_change_state_entry =
@@ -1569,6 +1594,8 @@ void net_init_clients(void)
 
     QTAILQ_INIT(&net_clients);
 
+    netdev_init_modern();
+
     qemu_opts_foreach(qemu_find_opts("netdev"), net_init_netdev, NULL,
                       &error_fatal);
 
@@ -1579,6 +1606,39 @@ void net_init_clients(void)
                       &error_fatal);
 }
 
+/*
+ * netdev_is_modern() returns true when the backend needs to bypass
+ * qemu_opts_parse_noisily()
+ */
+static bool netdev_is_modern(const char *optarg)
+{
+    return false;
+}
+
+/*
+ * netdev_parse_modern() uses modern, more expressive syntax than
+ * net_client_parse(), supports only the netdev option.
+ */
+int netdev_parse_modern(const char *optarg)
+{
+    Visitor *v;
+    NetdevQueueEntry *nd;
+
+    if (!netdev_is_modern(optarg)) {
+        return -1;
+    }
+
+    v = qobject_input_visitor_new_str(optarg, "type", &error_fatal);
+    nd = g_new(NetdevQueueEntry, 1);
+    visit_type_Netdev(v, NULL, &nd->nd, &error_fatal);
+    visit_free(v);
+    loc_save(&nd->loc);
+
+    QSIMPLEQ_INSERT_TAIL(&nd_queue, nd, entry);
+
+    return 0;
+}
+
 int net_client_parse(QemuOptsList *opts_list, const char *optarg)
 {
     if (!qemu_opts_parse_noisily(opts_list, optarg, true)) {
diff --git a/softmmu/vl.c b/softmmu/vl.c
index 8eed0f31c073..838f5b48c447 100644
--- a/softmmu/vl.c
+++ b/softmmu/vl.c
@@ -2839,7 +2839,8 @@ void qemu_init(int argc, char **argv, char **envp)
                 break;
             case QEMU_OPTION_netdev:
                 default_net = 0;
-                if (net_client_parse(qemu_find_opts("netdev"), optarg) == -1) {
+                if (netdev_parse_modern(optarg) == -1 &&
+                    net_client_parse(qemu_find_opts("netdev"), optarg) == -1) {
                     exit(1);
                 }
                 break;
-- 
2.36.1



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* [RFC PATCH v3 04/11] qapi: net: add stream and dgram netdevs
  2022-06-20 10:18 [RFC PATCH v3 00/11] qapi: net: add unix socket type support to netdev backend Laurent Vivier
                   ` (2 preceding siblings ...)
  2022-06-20 10:18 ` [RFC PATCH v3 03/11] qapi: net: introduce a way to bypass qemu_opts_parse_noisily() Laurent Vivier
@ 2022-06-20 10:18 ` Laurent Vivier
  2022-06-20 15:21   ` Markus Armbruster
  2022-06-20 10:18 ` [RFC PATCH v3 05/11] net: stream: Don't ignore EINVAL on netdev socket connection Laurent Vivier
                   ` (7 subsequent siblings)
  11 siblings, 1 reply; 28+ messages in thread
From: Laurent Vivier @ 2022-06-20 10:18 UTC (permalink / raw)
  To: qemu-devel
  Cc: Markus Armbruster, Eric Blake, Dr. David Alan Gilbert,
	Paolo Bonzini, Daniel P. Berrangé,
	Jason Wang, Laurent Vivier, Stefano Brivio

Copied from socket netdev file and modified to use SocketAddress
to be able to introduce new features like unix socket.

"udp" and "mcast" are squashed into dgram netdev, multicast is detected
according to the IP address type.
"listen" and "connect" modes are managed by stream netdev. An optional
parameter "server" defines the mode (server by default)

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
---
 hmp-commands.hx |   2 +-
 net/clients.h   |   6 +
 net/dgram.c     | 630 ++++++++++++++++++++++++++++++++++++++++++++++++
 net/hub.c       |   2 +
 net/meson.build |   2 +
 net/net.c       |  19 +-
 net/stream.c    | 425 ++++++++++++++++++++++++++++++++
 qapi/net.json   |  40 ++-
 qemu-options.hx |  12 +
 9 files changed, 1133 insertions(+), 5 deletions(-)
 create mode 100644 net/dgram.c
 create mode 100644 net/stream.c

diff --git a/hmp-commands.hx b/hmp-commands.hx
index 564f1de364df..2938d13725cc 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -1269,7 +1269,7 @@ ERST
     {
         .name       = "netdev_add",
         .args_type  = "netdev:O",
-        .params     = "[user|tap|socket|vde|bridge|hubport|netmap|vhost-user"
+        .params     = "[user|tap|socket|stream|dgram|vde|bridge|hubport|netmap|vhost-user"
 #ifdef CONFIG_VMNET
                       "|vmnet-host|vmnet-shared|vmnet-bridged"
 #endif
diff --git a/net/clients.h b/net/clients.h
index c9157789f2ce..ed8bdfff1e7c 100644
--- a/net/clients.h
+++ b/net/clients.h
@@ -40,6 +40,12 @@ int net_init_hubport(const Netdev *netdev, const char *name,
 int net_init_socket(const Netdev *netdev, const char *name,
                     NetClientState *peer, Error **errp);
 
+int net_init_stream(const Netdev *netdev, const char *name,
+                    NetClientState *peer, Error **errp);
+
+int net_init_dgram(const Netdev *netdev, const char *name,
+                   NetClientState *peer, Error **errp);
+
 int net_init_tap(const Netdev *netdev, const char *name,
                  NetClientState *peer, Error **errp);
 
diff --git a/net/dgram.c b/net/dgram.c
new file mode 100644
index 000000000000..aa4240501ed0
--- /dev/null
+++ b/net/dgram.c
@@ -0,0 +1,630 @@
+/*
+ * QEMU System Emulator
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#include "qemu/osdep.h"
+
+#include "net/net.h"
+#include "clients.h"
+#include "monitor/monitor.h"
+#include "qapi/error.h"
+#include "qemu/error-report.h"
+#include "qemu/option.h"
+#include "qemu/sockets.h"
+#include "qemu/iov.h"
+#include "qemu/main-loop.h"
+#include "qemu/cutils.h"
+
+typedef struct NetDgramState {
+    NetClientState nc;
+    int listen_fd;
+    int fd;
+    SocketReadState rs;
+  /* contains inet host and port destination iff connectionless (SOCK_DGRAM) */
+    struct sockaddr_in dgram_dst;
+    IOHandler *send_fn;           /* differs between SOCK_STREAM/SOCK_DGRAM */
+    bool read_poll;               /* waiting to receive data? */
+    bool write_poll;              /* waiting to transmit data? */
+} NetDgramState;
+
+static void net_dgram_accept(void *opaque);
+static void net_dgram_writable(void *opaque);
+
+static void net_dgram_update_fd_handler(NetDgramState *s)
+{
+    qemu_set_fd_handler(s->fd,
+                        s->read_poll ? s->send_fn : NULL,
+                        s->write_poll ? net_dgram_writable : NULL,
+                        s);
+}
+
+static void net_dgram_read_poll(NetDgramState *s, bool enable)
+{
+    s->read_poll = enable;
+    net_dgram_update_fd_handler(s);
+}
+
+static void net_dgram_write_poll(NetDgramState *s, bool enable)
+{
+    s->write_poll = enable;
+    net_dgram_update_fd_handler(s);
+}
+
+static void net_dgram_writable(void *opaque)
+{
+    NetDgramState *s = opaque;
+
+    net_dgram_write_poll(s, false);
+
+    qemu_flush_queued_packets(&s->nc);
+}
+
+static ssize_t net_dgram_receive_dgram(NetClientState *nc,
+                                       const uint8_t *buf, size_t size)
+{
+    NetDgramState *s = DO_UPCAST(NetDgramState, nc, nc);
+    ssize_t ret;
+
+    do {
+        if (s->dgram_dst.sin_family != AF_UNIX) {
+            ret = sendto(s->fd, buf, size, 0,
+                         (struct sockaddr *)&s->dgram_dst,
+                         sizeof(s->dgram_dst));
+        } else {
+            ret = send(s->fd, buf, size, 0);
+        }
+    } while (ret == -1 && errno == EINTR);
+
+    if (ret == -1 && errno == EAGAIN) {
+        net_dgram_write_poll(s, true);
+        return 0;
+    }
+    return ret;
+}
+
+static void net_dgram_send_completed(NetClientState *nc, ssize_t len)
+{
+    NetDgramState *s = DO_UPCAST(NetDgramState, nc, nc);
+
+    if (!s->read_poll) {
+        net_dgram_read_poll(s, true);
+    }
+}
+
+static void net_dgram_rs_finalize(SocketReadState *rs)
+{
+    NetDgramState *s = container_of(rs, NetDgramState, rs);
+
+    if (qemu_send_packet_async(&s->nc, rs->buf,
+                               rs->packet_len,
+                               net_dgram_send_completed) == 0) {
+        net_dgram_read_poll(s, false);
+    }
+}
+
+static void net_dgram_send(void *opaque)
+{
+    NetDgramState *s = opaque;
+    int size;
+    int ret;
+    uint8_t buf1[NET_BUFSIZE];
+    const uint8_t *buf;
+
+    size = recv(s->fd, buf1, sizeof(buf1), 0);
+    if (size < 0) {
+        if (errno != EWOULDBLOCK) {
+            goto eoc;
+        }
+    } else if (size == 0) {
+        /* end of connection */
+    eoc:
+        net_dgram_read_poll(s, false);
+        net_dgram_write_poll(s, false);
+        if (s->listen_fd != -1) {
+            qemu_set_fd_handler(s->listen_fd, net_dgram_accept, NULL, s);
+        }
+        closesocket(s->fd);
+
+        s->fd = -1;
+        net_socket_rs_init(&s->rs, net_dgram_rs_finalize, false);
+        s->nc.link_down = true;
+        memset(s->nc.info_str, 0, sizeof(s->nc.info_str));
+
+        return;
+    }
+    buf = buf1;
+
+    ret = net_fill_rstate(&s->rs, buf, size);
+
+    if (ret == -1) {
+        goto eoc;
+    }
+}
+
+static void net_dgram_send_dgram(void *opaque)
+{
+    NetDgramState *s = opaque;
+    int size;
+
+    size = recv(s->fd, s->rs.buf, sizeof(s->rs.buf), 0);
+    if (size < 0) {
+        return;
+    }
+    if (size == 0) {
+        /* end of connection */
+        net_dgram_read_poll(s, false);
+        net_dgram_write_poll(s, false);
+        return;
+    }
+    if (qemu_send_packet_async(&s->nc, s->rs.buf, size,
+                               net_dgram_send_completed) == 0) {
+        net_dgram_read_poll(s, false);
+    }
+}
+
+static int net_dgram_mcast_create(struct sockaddr_in *mcastaddr,
+                                  struct in_addr *localaddr,
+                                  Error **errp)
+{
+    struct ip_mreq imr;
+    int fd;
+    int val, ret;
+#ifdef __OpenBSD__
+    unsigned char loop;
+#else
+    int loop;
+#endif
+
+    if (!IN_MULTICAST(ntohl(mcastaddr->sin_addr.s_addr))) {
+        error_setg(errp, "specified mcastaddr %s (0x%08x) "
+                   "does not contain a multicast address",
+                   inet_ntoa(mcastaddr->sin_addr),
+                   (int)ntohl(mcastaddr->sin_addr.s_addr));
+        return -1;
+    }
+
+    fd = qemu_socket(PF_INET, SOCK_DGRAM, 0);
+    if (fd < 0) {
+        error_setg_errno(errp, errno, "can't create datagram socket");
+        return -1;
+    }
+
+    /*
+     * Allow multiple sockets to bind the same multicast ip and port by setting
+     * SO_REUSEADDR. This is the only situation where SO_REUSEADDR should be set
+     * on windows. Use socket_set_fast_reuse otherwise as it sets SO_REUSEADDR
+     * only on posix systems.
+     */
+    val = 1;
+    ret = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
+    if (ret < 0) {
+        error_setg_errno(errp, errno, "can't set socket option SO_REUSEADDR");
+        goto fail;
+    }
+
+    ret = bind(fd, (struct sockaddr *)mcastaddr, sizeof(*mcastaddr));
+    if (ret < 0) {
+        error_setg_errno(errp, errno, "can't bind ip=%s to socket",
+                         inet_ntoa(mcastaddr->sin_addr));
+        goto fail;
+    }
+
+    /* Add host to multicast group */
+    imr.imr_multiaddr = mcastaddr->sin_addr;
+    if (localaddr) {
+        imr.imr_interface = *localaddr;
+    } else {
+        imr.imr_interface.s_addr = htonl(INADDR_ANY);
+    }
+
+    ret = setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP,
+                     &imr, sizeof(struct ip_mreq));
+    if (ret < 0) {
+        error_setg_errno(errp, errno,
+                         "can't add socket to multicast group %s",
+                         inet_ntoa(imr.imr_multiaddr));
+        goto fail;
+    }
+
+    /* Force mcast msgs to loopback (eg. several QEMUs in same host */
+    loop = 1;
+    ret = setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP,
+                     &loop, sizeof(loop));
+    if (ret < 0) {
+        error_setg_errno(errp, errno,
+                         "can't force multicast message to loopback");
+        goto fail;
+    }
+
+    /* If a bind address is given, only send packets from that address */
+    if (localaddr != NULL) {
+        ret = setsockopt(fd, IPPROTO_IP, IP_MULTICAST_IF,
+                         localaddr, sizeof(*localaddr));
+        if (ret < 0) {
+            error_setg_errno(errp, errno,
+                             "can't set the default network send interface");
+            goto fail;
+        }
+    }
+
+    qemu_socket_set_nonblock(fd);
+    return fd;
+fail:
+    if (fd >= 0) {
+        closesocket(fd);
+    }
+    return -1;
+}
+
+static void net_dgram_cleanup(NetClientState *nc)
+{
+    NetDgramState *s = DO_UPCAST(NetDgramState, nc, nc);
+    if (s->fd != -1) {
+        net_dgram_read_poll(s, false);
+        net_dgram_write_poll(s, false);
+        close(s->fd);
+        s->fd = -1;
+    }
+    if (s->listen_fd != -1) {
+        qemu_set_fd_handler(s->listen_fd, NULL, NULL, NULL);
+        closesocket(s->listen_fd);
+        s->listen_fd = -1;
+    }
+}
+
+static NetClientInfo net_dgram_socket_info = {
+    .type = NET_CLIENT_DRIVER_DGRAM,
+    .size = sizeof(NetDgramState),
+    .receive = net_dgram_receive_dgram,
+    .cleanup = net_dgram_cleanup,
+};
+
+static NetDgramState *net_dgram_fd_init_dgram(NetClientState *peer,
+                                              const char *model,
+                                              const char *name,
+                                              int fd, int is_fd,
+                                              SocketAddress *mcast,
+                                              Error **errp)
+{
+    struct sockaddr_in saddr;
+    int newfd;
+    NetClientState *nc;
+    NetDgramState *s;
+    SocketAddress *sa;
+    SocketAddressType sa_type;
+
+    sa = socket_local_address(fd, errp);
+    if (!sa) {
+        return NULL;
+    }
+    sa_type = sa->type;
+    qapi_free_SocketAddress(sa);
+
+    /*
+     * fd passed: multicast: "learn" dgram_dst address from bound address and
+     * save it. Because this may be "shared" socket from a "master" process,
+     * datagrams would be recv() by ONLY ONE process: we must "clone" this
+     * dgram socket --jjo
+     */
+
+    if (is_fd && mcast != NULL) {
+            if (convert_host_port(&saddr, mcast->u.inet.host,
+                                  mcast->u.inet.port, errp) < 0) {
+                goto err;
+            }
+            /* must be bound */
+            if (saddr.sin_addr.s_addr == 0) {
+                error_setg(errp, "can't setup multicast destination address");
+                goto err;
+            }
+            /* clone dgram socket */
+            newfd = net_dgram_mcast_create(&saddr, NULL, errp);
+            if (newfd < 0) {
+                goto err;
+            }
+            /* clone newfd to fd, close newfd */
+            dup2(newfd, fd);
+            close(newfd);
+
+    }
+
+    nc = qemu_new_net_client(&net_dgram_socket_info, peer, model, name);
+
+    s = DO_UPCAST(NetDgramState, nc, nc);
+
+    s->fd = fd;
+    s->listen_fd = -1;
+    s->send_fn = net_dgram_send_dgram;
+    net_socket_rs_init(&s->rs, net_dgram_rs_finalize, false);
+    net_dgram_read_poll(s, true);
+
+    /* mcast: save bound address as dst */
+    if (is_fd && mcast != NULL) {
+        s->dgram_dst = saddr;
+        snprintf(nc->info_str, sizeof(nc->info_str),
+                 "fd=%d (cloned mcast=%s:%d)",
+                 fd, inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
+    } else {
+        if (sa_type == SOCKET_ADDRESS_TYPE_UNIX) {
+            s->dgram_dst.sin_family = AF_UNIX;
+        }
+
+        snprintf(nc->info_str, sizeof(nc->info_str), "fd=%d %s", fd,
+                 SocketAddressType_str(sa_type));
+    }
+
+    return s;
+
+err:
+    closesocket(fd);
+    return NULL;
+}
+
+static void net_dgram_connect(void *opaque)
+{
+    NetDgramState *s = opaque;
+    s->send_fn = net_dgram_send;
+    net_dgram_read_poll(s, true);
+}
+
+static void net_dgram_accept(void *opaque)
+{
+    NetDgramState *s = opaque;
+    struct sockaddr_in saddr;
+    socklen_t len;
+    int fd;
+
+    for (;;) {
+        len = sizeof(saddr);
+        fd = qemu_accept(s->listen_fd, (struct sockaddr *)&saddr, &len);
+        if (fd < 0 && errno != EINTR) {
+            return;
+        } else if (fd >= 0) {
+            qemu_set_fd_handler(s->listen_fd, NULL, NULL, NULL);
+            break;
+        }
+    }
+
+    s->fd = fd;
+    s->nc.link_down = false;
+    net_dgram_connect(s);
+    snprintf(s->nc.info_str, sizeof(s->nc.info_str), "connection from %s:%d",
+             inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
+}
+
+static int net_dgram_mcast_init(NetClientState *peer,
+                                const char *model,
+                                const char *name,
+                                SocketAddress *remote,
+                                SocketAddress *local,
+                                Error **errp)
+{
+    NetDgramState *s;
+    int fd, ret;
+    struct sockaddr_in saddr;
+
+    if (remote->type != SOCKET_ADDRESS_TYPE_INET) {
+        error_setg(errp, "multicast only support inet type");
+        return -1;
+    }
+
+    if (convert_host_port(&saddr, remote->u.inet.host, remote->u.inet.port,
+                          errp) < 0) {
+        return -1;
+    }
+
+    if (!local) {
+        fd = net_dgram_mcast_create(&saddr, NULL, errp);
+        if (fd < 0) {
+            return -1;
+        }
+    } else {
+        switch (local->type) {
+        case SOCKET_ADDRESS_TYPE_INET: {
+            struct in_addr localaddr;
+
+            if (inet_aton(local->u.inet.host, &localaddr) == 0) {
+                error_setg(errp, "localaddr '%s' is not a valid IPv4 address",
+                           local->u.inet.host);
+                return -1;
+            }
+
+            fd = net_dgram_mcast_create(&saddr, &localaddr, errp);
+            if (fd < 0) {
+                return -1;
+            }
+            break;
+        }
+        case SOCKET_ADDRESS_TYPE_FD:
+            fd = monitor_fd_param(monitor_cur(), local->u.fd.str, errp);
+            if (fd == -1) {
+                return -1;
+            }
+            ret = qemu_socket_try_set_nonblock(fd);
+            if (ret < 0) {
+                error_setg_errno(errp, -ret, "%s: Can't use file descriptor %d",
+                                 name, fd);
+                return -1;
+            }
+            break;
+        default:
+            error_setg(errp, "only support inet or fd type for local");
+            return -1;
+        }
+    }
+
+    s = net_dgram_fd_init_dgram(peer, model, name, fd,
+                                 local->type == SOCKET_ADDRESS_TYPE_FD,
+                                 remote, errp);
+    if (!s) {
+        return -1;
+    }
+
+    s->dgram_dst = saddr;
+
+    snprintf(s->nc.info_str, sizeof(s->nc.info_str), "mcast=%s:%d",
+             inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
+    return 0;
+
+}
+
+static int net_dgram_udp_init(NetClientState *peer,
+                              const char *model,
+                              const char *name,
+                              SocketAddress *remote,
+                              SocketAddress *local,
+                              Error **errp)
+{
+    NetDgramState *s;
+    int fd, ret;
+    struct sockaddr_in raddr_in;
+    gchar *info_str;
+
+    if (remote) {
+        if (local->type == SOCKET_ADDRESS_TYPE_FD) {
+            error_setg(errp, "don't set remote with local.fd");
+            return -1;
+        }
+        if (remote->type != local->type) {
+            error_setg(errp, "remote and local types must be the same");
+            return -1;
+        }
+    } else {
+        if (local->type != SOCKET_ADDRESS_TYPE_FD) {
+            error_setg(errp, "type=inet requires remote parameter");
+            return -1;
+        }
+    }
+
+    switch (local->type) {
+    case SOCKET_ADDRESS_TYPE_INET: {
+        struct sockaddr_in laddr_in;
+
+        if (convert_host_port(&laddr_in, local->u.inet.host, local->u.inet.port,
+                              errp) < 0) {
+            return -1;
+        }
+
+        if (convert_host_port(&raddr_in, remote->u.inet.host,
+                              remote->u.inet.port, errp) < 0) {
+            return -1;
+        }
+
+        fd = qemu_socket(PF_INET, SOCK_DGRAM, 0);
+        if (fd < 0) {
+            error_setg_errno(errp, errno, "can't create datagram socket");
+            return -1;
+        }
+
+        ret = socket_set_fast_reuse(fd);
+        if (ret < 0) {
+            error_setg_errno(errp, errno,
+                             "can't set socket option SO_REUSEADDR");
+            closesocket(fd);
+            return -1;
+        }
+        ret = bind(fd, (struct sockaddr *)&laddr_in, sizeof(laddr_in));
+        if (ret < 0) {
+            error_setg_errno(errp, errno, "can't bind ip=%s to socket",
+                             inet_ntoa(laddr_in.sin_addr));
+            closesocket(fd);
+            return -1;
+        }
+        qemu_socket_set_nonblock(fd);
+
+        info_str = g_strdup_printf("udp=%s:%d/%s:%d",
+                 inet_ntoa(laddr_in.sin_addr), ntohs(laddr_in.sin_port),
+                 inet_ntoa(raddr_in.sin_addr), ntohs(raddr_in.sin_port));
+
+        break;
+    }
+    case SOCKET_ADDRESS_TYPE_FD:
+        fd = monitor_fd_param(monitor_cur(), local->u.fd.str, errp);
+        if (fd == -1) {
+            return -1;
+        }
+        ret = qemu_socket_try_set_nonblock(fd);
+        if (ret < 0) {
+            error_setg_errno(errp, -ret, "%s: Can't use file descriptor %d",
+                             name, fd);
+            return -1;
+        }
+        break;
+    default:
+        error_setg(errp, "only support inet or fd type for local");
+        return -1;
+    }
+
+    s = net_dgram_fd_init_dgram(peer, model, name, fd, 0, NULL, errp);
+    if (!s) {
+        return -1;
+    }
+
+    if (remote) {
+        s->dgram_dst = raddr_in;
+
+        pstrcpy(s->nc.info_str, sizeof(s->nc.info_str), info_str);
+        g_free(info_str);
+    }
+    return 0;
+}
+
+static int net_dgram_init(NetClientState *peer,
+                          const char *model,
+                          const char *name,
+                          SocketAddress *remote,
+                          SocketAddress *local,
+                          Error **errp)
+{
+    /* detect multicast address */
+    if (remote && remote->type == SOCKET_ADDRESS_TYPE_INET) {
+        struct sockaddr_in mcastaddr;
+
+        if (convert_host_port(&mcastaddr, remote->u.inet.host,
+                              remote->u.inet.port, errp) < 0) {
+            return -1;
+        }
+
+        if (IN_MULTICAST(ntohl(mcastaddr.sin_addr.s_addr))) {
+            return net_dgram_mcast_init(peer, model, name, remote, local,
+                                           errp);
+        }
+    }
+    /* unicast address */
+    if (!local) {
+        error_setg(errp, "dgram requires local= parameter");
+        return -1;
+    }
+    return net_dgram_udp_init(peer, model, name, remote, local, errp);
+}
+
+int net_init_dgram(const Netdev *netdev, const char *name,
+                   NetClientState *peer, Error **errp)
+{
+    const NetdevDgramOptions *sock;
+
+    assert(netdev->type == NET_CLIENT_DRIVER_DGRAM);
+    sock = &netdev->u.dgram;
+
+    return net_dgram_init(peer, "dgram", name, sock->remote, sock->local,
+                          errp);
+}
diff --git a/net/hub.c b/net/hub.c
index 1375738bf121..67ca53485638 100644
--- a/net/hub.c
+++ b/net/hub.c
@@ -313,6 +313,8 @@ void net_hub_check_clients(void)
             case NET_CLIENT_DRIVER_USER:
             case NET_CLIENT_DRIVER_TAP:
             case NET_CLIENT_DRIVER_SOCKET:
+            case NET_CLIENT_DRIVER_STREAM:
+            case NET_CLIENT_DRIVER_DGRAM:
             case NET_CLIENT_DRIVER_VDE:
             case NET_CLIENT_DRIVER_VHOST_USER:
                 has_host_dev = 1;
diff --git a/net/meson.build b/net/meson.build
index 754e2d1d405c..896d86d43914 100644
--- a/net/meson.build
+++ b/net/meson.build
@@ -13,6 +13,8 @@ softmmu_ss.add(files(
   'net.c',
   'queue.c',
   'socket.c',
+  'stream.c',
+  'dgram.c',
   'util.c',
 ))
 
diff --git a/net/net.c b/net/net.c
index c337d3d753fe..440957b272ee 100644
--- a/net/net.c
+++ b/net/net.c
@@ -48,6 +48,7 @@
 #include "qemu/qemu-print.h"
 #include "qemu/main-loop.h"
 #include "qemu/option.h"
+#include "qemu/keyval.h"
 #include "qapi/error.h"
 #include "qapi/opts-visitor.h"
 #include "sysemu/runstate.h"
@@ -1014,6 +1015,8 @@ static int (* const net_client_init_fun[NET_CLIENT_DRIVER__MAX])(
 #endif
         [NET_CLIENT_DRIVER_TAP]       = net_init_tap,
         [NET_CLIENT_DRIVER_SOCKET]    = net_init_socket,
+        [NET_CLIENT_DRIVER_STREAM]    = net_init_stream,
+        [NET_CLIENT_DRIVER_DGRAM]     = net_init_dgram,
 #ifdef CONFIG_VDE
         [NET_CLIENT_DRIVER_VDE]       = net_init_vde,
 #endif
@@ -1101,6 +1104,8 @@ void show_netdevs(void)
     int idx;
     const char *available_netdevs[] = {
         "socket",
+        "stream",
+        "dgram",
         "hubport",
         "tap",
 #ifdef CONFIG_SLIRP
@@ -1612,7 +1617,19 @@ void net_init_clients(void)
  */
 static bool netdev_is_modern(const char *optarg)
 {
-    return false;
+    QDict *args;
+    const char *type;
+    bool is_modern;
+
+    args = keyval_parse(optarg, "type", NULL, NULL);
+    if (!args) {
+        return false;
+    }
+    type = qdict_get_try_str(args, "type");
+    is_modern = !g_strcmp0(type, "stream") || !g_strcmp0(type, "dgram");
+    qobject_unref(args);
+
+    return is_modern;
 }
 
 /*
diff --git a/net/stream.c b/net/stream.c
new file mode 100644
index 000000000000..fdc97ee43a56
--- /dev/null
+++ b/net/stream.c
@@ -0,0 +1,425 @@
+/*
+ * QEMU System Emulator
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#include "qemu/osdep.h"
+
+#include "net/net.h"
+#include "clients.h"
+#include "monitor/monitor.h"
+#include "qapi/error.h"
+#include "qemu/error-report.h"
+#include "qemu/option.h"
+#include "qemu/sockets.h"
+#include "qemu/iov.h"
+#include "qemu/main-loop.h"
+#include "qemu/cutils.h"
+
+typedef struct NetStreamState {
+    NetClientState nc;
+    int listen_fd;
+    int fd;
+    SocketReadState rs;
+    unsigned int send_index;      /* number of bytes sent*/
+    IOHandler *send_fn;
+    bool read_poll;               /* waiting to receive data? */
+    bool write_poll;              /* waiting to transmit data? */
+} NetStreamState;
+
+static void net_stream_accept(void *opaque);
+static void net_stream_writable(void *opaque);
+
+static void net_stream_update_fd_handler(NetStreamState *s)
+{
+    qemu_set_fd_handler(s->fd,
+                        s->read_poll ? s->send_fn : NULL,
+                        s->write_poll ? net_stream_writable : NULL,
+                        s);
+}
+
+static void net_stream_read_poll(NetStreamState *s, bool enable)
+{
+    s->read_poll = enable;
+    net_stream_update_fd_handler(s);
+}
+
+static void net_stream_write_poll(NetStreamState *s, bool enable)
+{
+    s->write_poll = enable;
+    net_stream_update_fd_handler(s);
+}
+
+static void net_stream_writable(void *opaque)
+{
+    NetStreamState *s = opaque;
+
+    net_stream_write_poll(s, false);
+
+    qemu_flush_queued_packets(&s->nc);
+}
+
+static ssize_t net_stream_receive(NetClientState *nc, const uint8_t *buf,
+                                  size_t size)
+{
+    NetStreamState *s = DO_UPCAST(NetStreamState, nc, nc);
+    uint32_t len = htonl(size);
+    struct iovec iov[] = {
+        {
+            .iov_base = &len,
+            .iov_len  = sizeof(len),
+        }, {
+            .iov_base = (void *)buf,
+            .iov_len  = size,
+        },
+    };
+    size_t remaining;
+    ssize_t ret;
+
+    remaining = iov_size(iov, 2) - s->send_index;
+    ret = iov_send(s->fd, iov, 2, s->send_index, remaining);
+
+    if (ret == -1 && errno == EAGAIN) {
+        ret = 0; /* handled further down */
+    }
+    if (ret == -1) {
+        s->send_index = 0;
+        return -errno;
+    }
+    if (ret < (ssize_t)remaining) {
+        s->send_index += ret;
+        net_stream_write_poll(s, true);
+        return 0;
+    }
+    s->send_index = 0;
+    return size;
+}
+
+static void net_stream_send_completed(NetClientState *nc, ssize_t len)
+{
+    NetStreamState *s = DO_UPCAST(NetStreamState, nc, nc);
+
+    if (!s->read_poll) {
+        net_stream_read_poll(s, true);
+    }
+}
+
+static void net_stream_rs_finalize(SocketReadState *rs)
+{
+    NetStreamState *s = container_of(rs, NetStreamState, rs);
+
+    if (qemu_send_packet_async(&s->nc, rs->buf,
+                               rs->packet_len,
+                               net_stream_send_completed) == 0) {
+        net_stream_read_poll(s, false);
+    }
+}
+
+static void net_stream_send(void *opaque)
+{
+    NetStreamState *s = opaque;
+    int size;
+    int ret;
+    uint8_t buf1[NET_BUFSIZE];
+    const uint8_t *buf;
+
+    size = recv(s->fd, buf1, sizeof(buf1), 0);
+    if (size < 0) {
+        if (errno != EWOULDBLOCK) {
+            goto eoc;
+        }
+    } else if (size == 0) {
+        /* end of connection */
+    eoc:
+        net_stream_read_poll(s, false);
+        net_stream_write_poll(s, false);
+        if (s->listen_fd != -1) {
+            qemu_set_fd_handler(s->listen_fd, net_stream_accept, NULL, s);
+        }
+        closesocket(s->fd);
+
+        s->fd = -1;
+        net_socket_rs_init(&s->rs, net_stream_rs_finalize, false);
+        s->nc.link_down = true;
+        memset(s->nc.info_str, 0, sizeof(s->nc.info_str));
+
+        return;
+    }
+    buf = buf1;
+
+    ret = net_fill_rstate(&s->rs, buf, size);
+
+    if (ret == -1) {
+        goto eoc;
+    }
+}
+
+static void net_stream_cleanup(NetClientState *nc)
+{
+    NetStreamState *s = DO_UPCAST(NetStreamState, nc, nc);
+    if (s->fd != -1) {
+        net_stream_read_poll(s, false);
+        net_stream_write_poll(s, false);
+        close(s->fd);
+        s->fd = -1;
+    }
+    if (s->listen_fd != -1) {
+        qemu_set_fd_handler(s->listen_fd, NULL, NULL, NULL);
+        closesocket(s->listen_fd);
+        s->listen_fd = -1;
+    }
+}
+
+static void net_stream_connect(void *opaque)
+{
+    NetStreamState *s = opaque;
+    s->send_fn = net_stream_send;
+    net_stream_read_poll(s, true);
+}
+
+static NetClientInfo net_stream_info = {
+    .type = NET_CLIENT_DRIVER_STREAM,
+    .size = sizeof(NetStreamState),
+    .receive = net_stream_receive,
+    .cleanup = net_stream_cleanup,
+};
+
+static NetStreamState *net_stream_fd_init_stream(NetClientState *peer,
+                                                 const char *model,
+                                                 const char *name,
+                                                 int fd, int is_connected)
+{
+    NetClientState *nc;
+    NetStreamState *s;
+
+    nc = qemu_new_net_client(&net_stream_info, peer, model, name);
+
+    snprintf(nc->info_str, sizeof(nc->info_str), "fd=%d", fd);
+
+    s = DO_UPCAST(NetStreamState, nc, nc);
+
+    s->fd = fd;
+    s->listen_fd = -1;
+    net_socket_rs_init(&s->rs, net_stream_rs_finalize, false);
+
+    /* Disable Nagle algorithm on TCP sockets to reduce latency */
+    socket_set_nodelay(fd);
+
+    if (is_connected) {
+        net_stream_connect(s);
+    } else {
+        qemu_set_fd_handler(s->fd, NULL, net_stream_connect, s);
+    }
+    return s;
+}
+
+static void net_stream_accept(void *opaque)
+{
+    NetStreamState *s = opaque;
+    struct sockaddr_in saddr;
+    socklen_t len;
+    int fd;
+
+    for (;;) {
+        len = sizeof(saddr);
+        fd = qemu_accept(s->listen_fd, (struct sockaddr *)&saddr, &len);
+        if (fd < 0 && errno != EINTR) {
+            return;
+        } else if (fd >= 0) {
+            qemu_set_fd_handler(s->listen_fd, NULL, NULL, NULL);
+            break;
+        }
+    }
+
+    s->fd = fd;
+    s->nc.link_down = false;
+    net_stream_connect(s);
+    snprintf(s->nc.info_str, sizeof(s->nc.info_str),
+             "connection from %s:%d",
+             inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
+}
+
+static int net_stream_server_init(NetClientState *peer,
+                                  const char *model,
+                                  const char *name,
+                                  SocketAddress *addr,
+                                  Error **errp)
+{
+    NetClientState *nc;
+    NetStreamState *s;
+    int fd, ret;
+
+    switch (addr->type) {
+    case SOCKET_ADDRESS_TYPE_INET: {
+        struct sockaddr_in saddr_in;
+
+        if (convert_host_port(&saddr_in, addr->u.inet.host, addr->u.inet.port,
+                              errp) < 0) {
+            return -1;
+        }
+
+        fd = qemu_socket(PF_INET, SOCK_STREAM, 0);
+        if (fd < 0) {
+            error_setg_errno(errp, errno, "can't create stream socket");
+            return -1;
+        }
+        qemu_socket_set_nonblock(fd);
+
+        socket_set_fast_reuse(fd);
+
+        ret = bind(fd, (struct sockaddr *)&saddr_in, sizeof(saddr_in));
+        if (ret < 0) {
+            error_setg_errno(errp, errno, "can't bind ip=%s to socket",
+                             inet_ntoa(saddr_in.sin_addr));
+            closesocket(fd);
+            return -1;
+        }
+        break;
+    }
+    case SOCKET_ADDRESS_TYPE_UNIX: {
+        error_setg(errp, "only support inet type");
+        return -1;
+    }
+    case SOCKET_ADDRESS_TYPE_FD:
+        fd = monitor_fd_param(monitor_cur(), addr->u.fd.str, errp);
+        if (fd == -1) {
+            return -1;
+        }
+        ret = qemu_socket_try_set_nonblock(fd);
+        if (ret < 0) {
+            error_setg_errno(errp, -ret, "%s: Can't use file descriptor %d",
+                             name, fd);
+            return -1;
+        }
+        break;
+    default:
+        g_assert_not_reached();
+    }
+
+    ret = listen(fd, 0);
+    if (ret < 0) {
+        error_setg_errno(errp, errno, "can't listen on socket");
+        closesocket(fd);
+        return -1;
+    }
+
+    nc = qemu_new_net_client(&net_stream_info, peer, model, name);
+    s = DO_UPCAST(NetStreamState, nc, nc);
+    s->fd = -1;
+    s->listen_fd = fd;
+    s->nc.link_down = true;
+    net_socket_rs_init(&s->rs, net_stream_rs_finalize, false);
+
+    qemu_set_fd_handler(s->listen_fd, net_stream_accept, NULL, s);
+    return 0;
+}
+
+static int net_stream_client_init(NetClientState *peer,
+                                  const char *model,
+                                  const char *name,
+                                  SocketAddress *addr,
+                                  Error **errp)
+{
+    NetStreamState *s;
+    int fd, connected, ret;
+    gchar *info_str;
+
+    switch (addr->type) {
+    case SOCKET_ADDRESS_TYPE_INET: {
+        struct sockaddr_in saddr_in;
+
+        if (convert_host_port(&saddr_in, addr->u.inet.host, addr->u.inet.port,
+                              errp) < 0) {
+            return -1;
+        }
+
+        fd = qemu_socket(PF_INET, SOCK_STREAM, 0);
+        if (fd < 0) {
+            error_setg_errno(errp, errno, "can't create stream socket");
+            return -1;
+        }
+        qemu_socket_set_nonblock(fd);
+
+        connected = 0;
+        for (;;) {
+            ret = connect(fd, (struct sockaddr *)&saddr_in, sizeof(saddr_in));
+            if (ret < 0) {
+                if (errno == EINTR || errno == EWOULDBLOCK) {
+                    /* continue */
+                } else if (errno == EINPROGRESS ||
+                           errno == EALREADY ||
+                           errno == EINVAL) {
+                    break;
+                } else {
+                    error_setg_errno(errp, errno, "can't connect socket");
+                    closesocket(fd);
+                    return -1;
+                }
+            } else {
+                connected = 1;
+                break;
+            }
+        }
+        info_str = g_strdup_printf("connect to %s:%d",
+                                   inet_ntoa(saddr_in.sin_addr),
+                                   ntohs(saddr_in.sin_port));
+        break;
+    }
+    case SOCKET_ADDRESS_TYPE_FD:
+        fd = monitor_fd_param(monitor_cur(), addr->u.fd.str, errp);
+        if (fd == -1) {
+            return -1;
+        }
+        ret = qemu_socket_try_set_nonblock(fd);
+        if (ret < 0) {
+            error_setg_errno(errp, -ret, "%s: Can't use file descriptor %d",
+                             name, fd);
+            return -1;
+        }
+        connected = 1;
+        info_str = g_strdup_printf("connect to fd %d", fd);
+        break;
+    default:
+        error_setg(errp, "only support inet or fd type");
+        return -1;
+    }
+
+    s = net_stream_fd_init_stream(peer, model, name, fd, connected);
+
+    pstrcpy(s->nc.info_str, sizeof(s->nc.info_str), info_str);
+    g_free(info_str);
+
+    return 0;
+}
+
+int net_init_stream(const Netdev *netdev, const char *name,
+                    NetClientState *peer, Error **errp)
+{
+    const NetdevStreamOptions *sock;
+
+    assert(netdev->type == NET_CLIENT_DRIVER_STREAM);
+    sock = &netdev->u.stream;
+
+    if (!sock->has_server || sock->server) {
+        return net_stream_server_init(peer, "stream", name, sock->addr, errp);
+    }
+    return net_stream_client_init(peer, "stream", name, sock->addr, errp);
+}
diff --git a/qapi/net.json b/qapi/net.json
index d6f7cfd4d656..5f72995b1d24 100644
--- a/qapi/net.json
+++ b/qapi/net.json
@@ -7,6 +7,7 @@
 ##
 
 { 'include': 'common.json' }
+{ 'include': 'sockets.json' }
 
 ##
 # @set_link:
@@ -566,6 +567,37 @@
     '*isolated':  'bool' },
   'if': 'CONFIG_VMNET' }
 
+##
+# @NetdevStreamOptions:
+#
+# Configuration info for stream socket netdev
+#
+# @addr: socket address to listen on (server=true)
+#        or connect to (server=false)
+# @server: create server socket (default: true)
+#
+# Since: 7.1
+##
+{ 'struct': 'NetdevStreamOptions',
+  'data': {
+    'addr':   'SocketAddress',
+    '*server': 'bool' } }
+
+##
+# @NetdevDgramOptions:
+#
+# Configuration info for datagram socket netdev.
+#
+# @remote: remote address
+# @local: local address
+#
+# Since: 7.1
+##
+{ 'struct': 'NetdevDgramOptions',
+  'data': {
+    '*local':  'SocketAddress',
+    '*remote': 'SocketAddress' } }
+
 ##
 # @NetClientDriver:
 #
@@ -579,9 +611,9 @@
 #        @vmnet-bridged since 7.1
 ##
 { 'enum': 'NetClientDriver',
-  'data': [ 'none', 'nic', 'user', 'tap', 'l2tpv3', 'socket', 'vde',
-            'bridge', 'hubport', 'netmap', 'vhost-user', 'vhost-vdpa',
-            { 'name': 'vmnet-host', 'if': 'CONFIG_VMNET' },
+  'data': [ 'none', 'nic', 'user', 'tap', 'l2tpv3', 'socket', 'stream',
+            'dgram', 'vde', 'bridge', 'hubport', 'netmap', 'vhost-user',
+            'vhost-vdpa', { 'name': 'vmnet-host', 'if': 'CONFIG_VMNET' },
             { 'name': 'vmnet-shared', 'if': 'CONFIG_VMNET' },
             { 'name': 'vmnet-bridged', 'if': 'CONFIG_VMNET' }] }
 
@@ -610,6 +642,8 @@
     'tap':      'NetdevTapOptions',
     'l2tpv3':   'NetdevL2TPv3Options',
     'socket':   'NetdevSocketOptions',
+    'stream':   'NetdevStreamOptions',
+    'dgram':    'NetdevDgramOptions',
     'vde':      'NetdevVdeOptions',
     'bridge':   'NetdevBridgeOptions',
     'hubport':  'NetdevHubPortOptions',
diff --git a/qemu-options.hx b/qemu-options.hx
index 60cf188da429..c87dcdc65ece 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -2727,6 +2727,18 @@ DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
     "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n"
     "                configure a network backend to connect to another network\n"
     "                using an UDP tunnel\n"
+    "-netdev stream,id=str[,server=on|off],addr.type=inet,addr.host=host,addr.port=port\n"
+    "-netdev stream,id=str[,server=on|off],addr.type=fd,addr.str=h\n"
+    "                configure a network backend to connect to another network\n"
+    "                using a socket connection in stream mode.\n"
+    "-netdev dgram,id=str,remote.type=inet,remote.host=maddr,remote.port=port[,local.type=inet,local.host=addr]\n"
+    "-netdev dgram,id=str,remote.type=inet,remote.host=maddr,remote.port=port[,local.type=fd,local.str=h]\n"
+    "                configure a network backend to connect to a multicast maddr and port\n"
+    "                use 'local.host=addr' to specify the host address to send packets from\n"
+    "-netdev dgram,id=str,local.type=inet,local.host=host,local.port=port[,remote.type=inet,remote.host=host,remote.port=port]\n"
+    "-netdev dgram,id=str,local.type=fd,local.str=h\n"
+    "                configure a network backend to connect to another network\n"
+    "                using an UDP tunnel\n"
 #ifdef CONFIG_VDE
     "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
     "                configure a network backend to connect to port 'n' of a vde switch\n"
-- 
2.36.1



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* [RFC PATCH v3 05/11] net: stream: Don't ignore EINVAL on netdev socket connection
  2022-06-20 10:18 [RFC PATCH v3 00/11] qapi: net: add unix socket type support to netdev backend Laurent Vivier
                   ` (3 preceding siblings ...)
  2022-06-20 10:18 ` [RFC PATCH v3 04/11] qapi: net: add stream and dgram netdevs Laurent Vivier
@ 2022-06-20 10:18 ` Laurent Vivier
  2022-06-20 10:18 ` [RFC PATCH v3 06/11] net: stream: add unix socket Laurent Vivier
                   ` (6 subsequent siblings)
  11 siblings, 0 replies; 28+ messages in thread
From: Laurent Vivier @ 2022-06-20 10:18 UTC (permalink / raw)
  To: qemu-devel
  Cc: Markus Armbruster, Eric Blake, Dr. David Alan Gilbert,
	Paolo Bonzini, Daniel P. Berrangé,
	Jason Wang, Stefano Brivio, Laurent Vivier

From: Stefano Brivio <sbrivio@redhat.com>

Other errors are treated as failure by net_stream_client_init(),
but if connect() returns EINVAL, we'll fail silently. Remove the
related exception.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
[lvivier: applied to net/stream.c]
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
---
 net/stream.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/net/stream.c b/net/stream.c
index fdc97ee43a56..12fc26b9f4c7 100644
--- a/net/stream.c
+++ b/net/stream.c
@@ -365,8 +365,7 @@ static int net_stream_client_init(NetClientState *peer,
                 if (errno == EINTR || errno == EWOULDBLOCK) {
                     /* continue */
                 } else if (errno == EINPROGRESS ||
-                           errno == EALREADY ||
-                           errno == EINVAL) {
+                           errno == EALREADY) {
                     break;
                 } else {
                     error_setg_errno(errp, errno, "can't connect socket");
-- 
2.36.1



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* [RFC PATCH v3 06/11] net: stream: add unix socket
  2022-06-20 10:18 [RFC PATCH v3 00/11] qapi: net: add unix socket type support to netdev backend Laurent Vivier
                   ` (4 preceding siblings ...)
  2022-06-20 10:18 ` [RFC PATCH v3 05/11] net: stream: Don't ignore EINVAL on netdev socket connection Laurent Vivier
@ 2022-06-20 10:18 ` Laurent Vivier
  2022-06-20 10:18 ` [RFC PATCH v3 07/11] net: dgram: make dgram_dst generic Laurent Vivier
                   ` (5 subsequent siblings)
  11 siblings, 0 replies; 28+ messages in thread
From: Laurent Vivier @ 2022-06-20 10:18 UTC (permalink / raw)
  To: qemu-devel
  Cc: Markus Armbruster, Eric Blake, Dr. David Alan Gilbert,
	Paolo Bonzini, Daniel P. Berrangé,
	Jason Wang, Laurent Vivier, Stefano Brivio

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
---
 net/stream.c | 106 +++++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 99 insertions(+), 7 deletions(-)

diff --git a/net/stream.c b/net/stream.c
index 12fc26b9f4c7..dca50508ed84 100644
--- a/net/stream.c
+++ b/net/stream.c
@@ -234,7 +234,7 @@ static NetStreamState *net_stream_fd_init_stream(NetClientState *peer,
 static void net_stream_accept(void *opaque)
 {
     NetStreamState *s = opaque;
-    struct sockaddr_in saddr;
+    struct sockaddr_storage saddr;
     socklen_t len;
     int fd;
 
@@ -252,9 +252,27 @@ static void net_stream_accept(void *opaque)
     s->fd = fd;
     s->nc.link_down = false;
     net_stream_connect(s);
-    snprintf(s->nc.info_str, sizeof(s->nc.info_str),
-             "connection from %s:%d",
-             inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
+    switch (saddr.ss_family) {
+    case AF_INET: {
+        struct sockaddr_in *saddr_in = (struct sockaddr_in *)&saddr;
+
+        snprintf(s->nc.info_str, sizeof(s->nc.info_str),
+                 "connection from %s:%d",
+                 inet_ntoa(saddr_in->sin_addr), ntohs(saddr_in->sin_port));
+        break;
+    }
+    case AF_UNIX: {
+        struct sockaddr_un saddr_un;
+
+        len = sizeof(saddr_un);
+        getsockname(s->listen_fd, (struct sockaddr *)&saddr_un, &len);
+        snprintf(s->nc.info_str, sizeof(s->nc.info_str),
+                 "connect from %s", saddr_un.sun_path);
+        break;
+    }
+    default:
+        g_assert_not_reached();
+    }
 }
 
 static int net_stream_server_init(NetClientState *peer,
@@ -295,8 +313,40 @@ static int net_stream_server_init(NetClientState *peer,
         break;
     }
     case SOCKET_ADDRESS_TYPE_UNIX: {
-        error_setg(errp, "only support inet type");
-        return -1;
+        struct sockaddr_un saddr_un;
+
+        ret = unlink(addr->u.q_unix.path);
+        if (ret < 0 && errno != ENOENT) {
+            error_setg_errno(errp, errno, "failed to unlink socket %s",
+                             addr->u.q_unix.path);
+            return -1;
+        }
+
+        saddr_un.sun_family = PF_UNIX;
+        ret = snprintf(saddr_un.sun_path, sizeof(saddr_un.sun_path), "%s",
+                       addr->u.q_unix.path);
+        if (ret < 0 || ret >= sizeof(saddr_un.sun_path)) {
+            error_setg(errp, "UNIX socket path '%s' is too long",
+                       addr->u.q_unix.path);
+            error_append_hint(errp, "Path must be less than %zu bytes\n",
+                              sizeof(saddr_un.sun_path));
+        }
+
+        fd = qemu_socket(PF_UNIX, SOCK_STREAM, 0);
+        if (fd < 0) {
+            error_setg_errno(errp, errno, "can't create stream socket");
+            return -1;
+        }
+        qemu_socket_set_nonblock(fd);
+
+        ret = bind(fd, (struct sockaddr *)&saddr_un, sizeof(saddr_un));
+        if (ret < 0) {
+            error_setg_errno(errp, errno, "can't create socket with path: %s",
+                             saddr_un.sun_path);
+            closesocket(fd);
+            return -1;
+        }
+        break;
     }
     case SOCKET_ADDRESS_TYPE_FD:
         fd = monitor_fd_param(monitor_cur(), addr->u.fd.str, errp);
@@ -382,6 +432,48 @@ static int net_stream_client_init(NetClientState *peer,
                                    ntohs(saddr_in.sin_port));
         break;
     }
+    case SOCKET_ADDRESS_TYPE_UNIX: {
+        struct sockaddr_un saddr_un;
+
+        saddr_un.sun_family = PF_UNIX;
+        ret = snprintf(saddr_un.sun_path, sizeof(saddr_un.sun_path), "%s",
+                       addr->u.q_unix.path);
+        if (ret < 0 || ret >= sizeof(saddr_un.sun_path)) {
+            error_setg(errp, "UNIX socket path '%s' is too long",
+                       addr->u.q_unix.path);
+            error_append_hint(errp, "Path must be less than %zu bytes\n",
+                              sizeof(saddr_un.sun_path));
+        }
+
+        fd = qemu_socket(PF_UNIX, SOCK_STREAM, 0);
+        if (fd < 0) {
+            error_setg_errno(errp, errno, "can't create stream socket");
+            return -1;
+        }
+        qemu_socket_set_nonblock(fd);
+
+        connected = 0;
+        for (;;) {
+            ret = connect(fd, (struct sockaddr *)&saddr_un, sizeof(saddr_un));
+            if (ret < 0) {
+                if (errno == EINTR || errno == EWOULDBLOCK) {
+                    /* continue */
+                } else if (errno == EAGAIN ||
+                           errno == EALREADY) {
+                    break;
+                } else {
+                    error_setg_errno(errp, errno, "can't connect socket");
+                    closesocket(fd);
+                    return -1;
+                }
+            } else {
+                connected = 1;
+                break;
+            }
+        }
+        info_str = g_strdup_printf(" connect to %s", saddr_un.sun_path);
+        break;
+    }
     case SOCKET_ADDRESS_TYPE_FD:
         fd = monitor_fd_param(monitor_cur(), addr->u.fd.str, errp);
         if (fd == -1) {
@@ -397,7 +489,7 @@ static int net_stream_client_init(NetClientState *peer,
         info_str = g_strdup_printf("connect to fd %d", fd);
         break;
     default:
-        error_setg(errp, "only support inet or fd type");
+        error_setg(errp, "only support inet, unix or fd type");
         return -1;
     }
 
-- 
2.36.1



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* [RFC PATCH v3 07/11] net: dgram: make dgram_dst generic
  2022-06-20 10:18 [RFC PATCH v3 00/11] qapi: net: add unix socket type support to netdev backend Laurent Vivier
                   ` (5 preceding siblings ...)
  2022-06-20 10:18 ` [RFC PATCH v3 06/11] net: stream: add unix socket Laurent Vivier
@ 2022-06-20 10:18 ` Laurent Vivier
  2022-06-20 10:18 ` [RFC PATCH v3 08/11] net: dgram: move mcast specific code from net_socket_fd_init_dgram() Laurent Vivier
                   ` (4 subsequent siblings)
  11 siblings, 0 replies; 28+ messages in thread
From: Laurent Vivier @ 2022-06-20 10:18 UTC (permalink / raw)
  To: qemu-devel
  Cc: Markus Armbruster, Eric Blake, Dr. David Alan Gilbert,
	Paolo Bonzini, Daniel P. Berrangé,
	Jason Wang, Laurent Vivier, Stefano Brivio

dgram_dst is a sockaddr_in structure. To be able to use it with
unix socket, use a pointer to a generic sockaddr structure.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
---
 net/dgram.c | 76 +++++++++++++++++++++++++++++++----------------------
 1 file changed, 45 insertions(+), 31 deletions(-)

diff --git a/net/dgram.c b/net/dgram.c
index aa4240501ed0..16b4d4c94c81 100644
--- a/net/dgram.c
+++ b/net/dgram.c
@@ -39,9 +39,8 @@ typedef struct NetDgramState {
     int listen_fd;
     int fd;
     SocketReadState rs;
-  /* contains inet host and port destination iff connectionless (SOCK_DGRAM) */
-    struct sockaddr_in dgram_dst;
-    IOHandler *send_fn;           /* differs between SOCK_STREAM/SOCK_DGRAM */
+    struct sockaddr *dgram_dst; /* contains destination iff connectionless */
+    IOHandler *send_fn;
     bool read_poll;               /* waiting to receive data? */
     bool write_poll;              /* waiting to transmit data? */
 } NetDgramState;
@@ -85,10 +84,9 @@ static ssize_t net_dgram_receive_dgram(NetClientState *nc,
     ssize_t ret;
 
     do {
-        if (s->dgram_dst.sin_family != AF_UNIX) {
-            ret = sendto(s->fd, buf, size, 0,
-                         (struct sockaddr *)&s->dgram_dst,
-                         sizeof(s->dgram_dst));
+        if (s->dgram_dst) {
+            ret = sendto(s->fd, buf, size, 0, s->dgram_dst,
+                         sizeof(struct sockaddr_in));
         } else {
             ret = send(s->fd, buf, size, 0);
         }
@@ -289,6 +287,8 @@ static void net_dgram_cleanup(NetClientState *nc)
         closesocket(s->listen_fd);
         s->listen_fd = -1;
     }
+    g_free(s->dgram_dst);
+    s->dgram_dst = NULL;
 }
 
 static NetClientInfo net_dgram_socket_info = {
@@ -305,7 +305,7 @@ static NetDgramState *net_dgram_fd_init_dgram(NetClientState *peer,
                                               SocketAddress *mcast,
                                               Error **errp)
 {
-    struct sockaddr_in saddr;
+    struct sockaddr_in *saddr = NULL;
     int newfd;
     NetClientState *nc;
     NetDgramState *s;
@@ -327,24 +327,25 @@ static NetDgramState *net_dgram_fd_init_dgram(NetClientState *peer,
      */
 
     if (is_fd && mcast != NULL) {
-            if (convert_host_port(&saddr, mcast->u.inet.host,
-                                  mcast->u.inet.port, errp) < 0) {
+            saddr = g_new(struct sockaddr_in, 1);
+
+            if (convert_host_port(saddr, mcast->u.inet.host, mcast->u.inet.port,
+                                  errp) < 0) {
                 goto err;
             }
             /* must be bound */
-            if (saddr.sin_addr.s_addr == 0) {
+            if (saddr->sin_addr.s_addr == 0) {
                 error_setg(errp, "can't setup multicast destination address");
                 goto err;
             }
             /* clone dgram socket */
-            newfd = net_dgram_mcast_create(&saddr, NULL, errp);
+            newfd = net_dgram_mcast_create(saddr, NULL, errp);
             if (newfd < 0) {
                 goto err;
             }
             /* clone newfd to fd, close newfd */
             dup2(newfd, fd);
             close(newfd);
-
     }
 
     nc = qemu_new_net_client(&net_dgram_socket_info, peer, model, name);
@@ -358,16 +359,13 @@ static NetDgramState *net_dgram_fd_init_dgram(NetClientState *peer,
     net_dgram_read_poll(s, true);
 
     /* mcast: save bound address as dst */
-    if (is_fd && mcast != NULL) {
-        s->dgram_dst = saddr;
+    if (saddr) {
+        g_assert(s->dgram_dst == NULL);
+        s->dgram_dst = (struct sockaddr *)saddr;
         snprintf(nc->info_str, sizeof(nc->info_str),
                  "fd=%d (cloned mcast=%s:%d)",
-                 fd, inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
+                 fd, inet_ntoa(saddr->sin_addr), ntohs(saddr->sin_port));
     } else {
-        if (sa_type == SOCKET_ADDRESS_TYPE_UNIX) {
-            s->dgram_dst.sin_family = AF_UNIX;
-        }
-
         snprintf(nc->info_str, sizeof(nc->info_str), "fd=%d %s", fd,
                  SocketAddressType_str(sa_type));
     }
@@ -375,6 +373,7 @@ static NetDgramState *net_dgram_fd_init_dgram(NetClientState *peer,
     return s;
 
 err:
+    g_free(saddr);
     closesocket(fd);
     return NULL;
 }
@@ -420,21 +419,24 @@ static int net_dgram_mcast_init(NetClientState *peer,
 {
     NetDgramState *s;
     int fd, ret;
-    struct sockaddr_in saddr;
+    struct sockaddr_in *saddr;
 
     if (remote->type != SOCKET_ADDRESS_TYPE_INET) {
         error_setg(errp, "multicast only support inet type");
         return -1;
     }
 
-    if (convert_host_port(&saddr, remote->u.inet.host, remote->u.inet.port,
+    saddr = g_new(struct sockaddr_in, 1);
+    if (convert_host_port(saddr, remote->u.inet.host, remote->u.inet.port,
                           errp) < 0) {
+        g_free(saddr);
         return -1;
     }
 
     if (!local) {
-        fd = net_dgram_mcast_create(&saddr, NULL, errp);
+        fd = net_dgram_mcast_create(saddr, NULL, errp);
         if (fd < 0) {
+            g_free(saddr);
             return -1;
         }
     } else {
@@ -443,13 +445,15 @@ static int net_dgram_mcast_init(NetClientState *peer,
             struct in_addr localaddr;
 
             if (inet_aton(local->u.inet.host, &localaddr) == 0) {
+                g_free(saddr);
                 error_setg(errp, "localaddr '%s' is not a valid IPv4 address",
                            local->u.inet.host);
                 return -1;
             }
 
-            fd = net_dgram_mcast_create(&saddr, &localaddr, errp);
+            fd = net_dgram_mcast_create(saddr, &localaddr, errp);
             if (fd < 0) {
+                g_free(saddr);
                 return -1;
             }
             break;
@@ -457,16 +461,19 @@ static int net_dgram_mcast_init(NetClientState *peer,
         case SOCKET_ADDRESS_TYPE_FD:
             fd = monitor_fd_param(monitor_cur(), local->u.fd.str, errp);
             if (fd == -1) {
+                g_free(saddr);
                 return -1;
             }
             ret = qemu_socket_try_set_nonblock(fd);
             if (ret < 0) {
+                g_free(saddr);
                 error_setg_errno(errp, -ret, "%s: Can't use file descriptor %d",
                                  name, fd);
                 return -1;
             }
             break;
         default:
+            g_free(saddr);
             error_setg(errp, "only support inet or fd type for local");
             return -1;
         }
@@ -476,13 +483,16 @@ static int net_dgram_mcast_init(NetClientState *peer,
                                  local->type == SOCKET_ADDRESS_TYPE_FD,
                                  remote, errp);
     if (!s) {
+        g_free(saddr);
         return -1;
     }
 
-    s->dgram_dst = saddr;
+    g_assert(s->dgram_dst == NULL);
+    s->dgram_dst = (struct sockaddr *)saddr;
 
     snprintf(s->nc.info_str, sizeof(s->nc.info_str), "mcast=%s:%d",
-             inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
+             inet_ntoa(saddr->sin_addr), ntohs(saddr->sin_port));
+
     return 0;
 
 }
@@ -496,8 +506,8 @@ static int net_dgram_udp_init(NetClientState *peer,
 {
     NetDgramState *s;
     int fd, ret;
-    struct sockaddr_in raddr_in;
     gchar *info_str;
+    struct sockaddr *dgram_dst;
 
     if (remote) {
         if (local->type == SOCKET_ADDRESS_TYPE_FD) {
@@ -517,7 +527,7 @@ static int net_dgram_udp_init(NetClientState *peer,
 
     switch (local->type) {
     case SOCKET_ADDRESS_TYPE_INET: {
-        struct sockaddr_in laddr_in;
+        struct sockaddr_in laddr_in, raddr_in;
 
         if (convert_host_port(&laddr_in, local->u.inet.host, local->u.inet.port,
                               errp) < 0) {
@@ -551,9 +561,12 @@ static int net_dgram_udp_init(NetClientState *peer,
         }
         qemu_socket_set_nonblock(fd);
 
+        dgram_dst = g_malloc(sizeof(raddr_in));
+        memcpy(dgram_dst, &raddr_in, sizeof(raddr_in));
+
         info_str = g_strdup_printf("udp=%s:%d/%s:%d",
-                 inet_ntoa(laddr_in.sin_addr), ntohs(laddr_in.sin_port),
-                 inet_ntoa(raddr_in.sin_addr), ntohs(raddr_in.sin_port));
+                        inet_ntoa(laddr_in.sin_addr), ntohs(laddr_in.sin_port),
+                        inet_ntoa(raddr_in.sin_addr), ntohs(raddr_in.sin_port));
 
         break;
     }
@@ -580,7 +593,8 @@ static int net_dgram_udp_init(NetClientState *peer,
     }
 
     if (remote) {
-        s->dgram_dst = raddr_in;
+        g_assert(s->dgram_dst == NULL);
+        s->dgram_dst = dgram_dst;
 
         pstrcpy(s->nc.info_str, sizeof(s->nc.info_str), info_str);
         g_free(info_str);
-- 
2.36.1



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* [RFC PATCH v3 08/11] net: dgram: move mcast specific code from net_socket_fd_init_dgram()
  2022-06-20 10:18 [RFC PATCH v3 00/11] qapi: net: add unix socket type support to netdev backend Laurent Vivier
                   ` (6 preceding siblings ...)
  2022-06-20 10:18 ` [RFC PATCH v3 07/11] net: dgram: make dgram_dst generic Laurent Vivier
@ 2022-06-20 10:18 ` Laurent Vivier
  2022-06-20 10:18 ` [RFC PATCH v3 09/11] net: dgram: add unix socket Laurent Vivier
                   ` (3 subsequent siblings)
  11 siblings, 0 replies; 28+ messages in thread
From: Laurent Vivier @ 2022-06-20 10:18 UTC (permalink / raw)
  To: qemu-devel
  Cc: Markus Armbruster, Eric Blake, Dr. David Alan Gilbert,
	Paolo Bonzini, Daniel P. Berrangé,
	Jason Wang, Laurent Vivier, Stefano Brivio

It is less complex to manage special cases directly in
net_dgram_mcast_init() and net_dgram_udp_init().

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
---
 net/dgram.c | 143 +++++++++++++++++++++++++++-------------------------
 1 file changed, 73 insertions(+), 70 deletions(-)

diff --git a/net/dgram.c b/net/dgram.c
index 16b4d4c94c81..c0cf0410792e 100644
--- a/net/dgram.c
+++ b/net/dgram.c
@@ -301,52 +301,11 @@ static NetClientInfo net_dgram_socket_info = {
 static NetDgramState *net_dgram_fd_init_dgram(NetClientState *peer,
                                               const char *model,
                                               const char *name,
-                                              int fd, int is_fd,
-                                              SocketAddress *mcast,
+                                              int fd,
                                               Error **errp)
 {
-    struct sockaddr_in *saddr = NULL;
-    int newfd;
     NetClientState *nc;
     NetDgramState *s;
-    SocketAddress *sa;
-    SocketAddressType sa_type;
-
-    sa = socket_local_address(fd, errp);
-    if (!sa) {
-        return NULL;
-    }
-    sa_type = sa->type;
-    qapi_free_SocketAddress(sa);
-
-    /*
-     * fd passed: multicast: "learn" dgram_dst address from bound address and
-     * save it. Because this may be "shared" socket from a "master" process,
-     * datagrams would be recv() by ONLY ONE process: we must "clone" this
-     * dgram socket --jjo
-     */
-
-    if (is_fd && mcast != NULL) {
-            saddr = g_new(struct sockaddr_in, 1);
-
-            if (convert_host_port(saddr, mcast->u.inet.host, mcast->u.inet.port,
-                                  errp) < 0) {
-                goto err;
-            }
-            /* must be bound */
-            if (saddr->sin_addr.s_addr == 0) {
-                error_setg(errp, "can't setup multicast destination address");
-                goto err;
-            }
-            /* clone dgram socket */
-            newfd = net_dgram_mcast_create(saddr, NULL, errp);
-            if (newfd < 0) {
-                goto err;
-            }
-            /* clone newfd to fd, close newfd */
-            dup2(newfd, fd);
-            close(newfd);
-    }
 
     nc = qemu_new_net_client(&net_dgram_socket_info, peer, model, name);
 
@@ -358,24 +317,7 @@ static NetDgramState *net_dgram_fd_init_dgram(NetClientState *peer,
     net_socket_rs_init(&s->rs, net_dgram_rs_finalize, false);
     net_dgram_read_poll(s, true);
 
-    /* mcast: save bound address as dst */
-    if (saddr) {
-        g_assert(s->dgram_dst == NULL);
-        s->dgram_dst = (struct sockaddr *)saddr;
-        snprintf(nc->info_str, sizeof(nc->info_str),
-                 "fd=%d (cloned mcast=%s:%d)",
-                 fd, inet_ntoa(saddr->sin_addr), ntohs(saddr->sin_port));
-    } else {
-        snprintf(nc->info_str, sizeof(nc->info_str), "fd=%d %s", fd,
-                 SocketAddressType_str(sa_type));
-    }
-
     return s;
-
-err:
-    g_free(saddr);
-    closesocket(fd);
-    return NULL;
 }
 
 static void net_dgram_connect(void *opaque)
@@ -420,6 +362,7 @@ static int net_dgram_mcast_init(NetClientState *peer,
     NetDgramState *s;
     int fd, ret;
     struct sockaddr_in *saddr;
+    gchar *info_str;
 
     if (remote->type != SOCKET_ADDRESS_TYPE_INET) {
         error_setg(errp, "multicast only support inet type");
@@ -439,6 +382,9 @@ static int net_dgram_mcast_init(NetClientState *peer,
             g_free(saddr);
             return -1;
         }
+        info_str = g_strdup_printf("mcast=%s:%d",
+                                   inet_ntoa(saddr->sin_addr),
+                                   ntohs(saddr->sin_port));
     } else {
         switch (local->type) {
         case SOCKET_ADDRESS_TYPE_INET: {
@@ -456,9 +402,14 @@ static int net_dgram_mcast_init(NetClientState *peer,
                 g_free(saddr);
                 return -1;
             }
+            info_str = g_strdup_printf("mcast=%s:%d",
+                                       inet_ntoa(saddr->sin_addr),
+                                       ntohs(saddr->sin_port));
             break;
         }
-        case SOCKET_ADDRESS_TYPE_FD:
+        case SOCKET_ADDRESS_TYPE_FD: {
+            int newfd;
+
             fd = monitor_fd_param(monitor_cur(), local->u.fd.str, errp);
             if (fd == -1) {
                 g_free(saddr);
@@ -471,7 +422,46 @@ static int net_dgram_mcast_init(NetClientState *peer,
                                  name, fd);
                 return -1;
             }
+
+            /*
+             * fd passed: multicast: "learn" dgram_dst address from bound
+             * address and save it. Because this may be "shared" socket from a
+             * "master" process, datagrams would be recv() by ONLY ONE process:
+             * we must "clone" this dgram socket --jjo
+             */
+
+            saddr = g_new(struct sockaddr_in, 1);
+
+            if (convert_host_port(saddr, local->u.inet.host, local->u.inet.port,
+                                  errp) < 0) {
+                g_free(saddr);
+                closesocket(fd);
+                return -1;
+            }
+
+            /* must be bound */
+            if (saddr->sin_addr.s_addr == 0) {
+                error_setg(errp, "can't setup multicast destination address");
+                g_free(saddr);
+                closesocket(fd);
+                return -1;
+            }
+            /* clone dgram socket */
+            newfd = net_dgram_mcast_create(saddr, NULL, errp);
+            if (newfd < 0) {
+                g_free(saddr);
+                closesocket(fd);
+                return -1;
+            }
+            /* clone newfd to fd, close newfd */
+            dup2(newfd, fd);
+            close(newfd);
+
+            info_str = g_strdup_printf("fd=%d (cloned mcast=%s:%d)",
+                                       fd, inet_ntoa(saddr->sin_addr),
+                                       ntohs(saddr->sin_port));
             break;
+        }
         default:
             g_free(saddr);
             error_setg(errp, "only support inet or fd type for local");
@@ -479,9 +469,7 @@ static int net_dgram_mcast_init(NetClientState *peer,
         }
     }
 
-    s = net_dgram_fd_init_dgram(peer, model, name, fd,
-                                 local->type == SOCKET_ADDRESS_TYPE_FD,
-                                 remote, errp);
+    s = net_dgram_fd_init_dgram(peer, model, name, fd, errp);
     if (!s) {
         g_free(saddr);
         return -1;
@@ -490,8 +478,8 @@ static int net_dgram_mcast_init(NetClientState *peer,
     g_assert(s->dgram_dst == NULL);
     s->dgram_dst = (struct sockaddr *)saddr;
 
-    snprintf(s->nc.info_str, sizeof(s->nc.info_str), "mcast=%s:%d",
-             inet_ntoa(saddr->sin_addr), ntohs(saddr->sin_port));
+    pstrcpy(s->nc.info_str, sizeof(s->nc.info_str), info_str);
+    g_free(info_str);
 
     return 0;
 
@@ -570,7 +558,10 @@ static int net_dgram_udp_init(NetClientState *peer,
 
         break;
     }
-    case SOCKET_ADDRESS_TYPE_FD:
+    case SOCKET_ADDRESS_TYPE_FD: {
+        SocketAddress *sa;
+        SocketAddressType sa_type;
+
         fd = monitor_fd_param(monitor_cur(), local->u.fd.str, errp);
         if (fd == -1) {
             return -1;
@@ -581,23 +572,35 @@ static int net_dgram_udp_init(NetClientState *peer,
                              name, fd);
             return -1;
         }
+
+        sa = socket_local_address(fd, errp);
+        if (sa) {
+            sa_type = sa->type;
+            qapi_free_SocketAddress(sa);
+
+            info_str = g_strdup_printf("fd=%d %s", fd,
+                                       SocketAddressType_str(sa_type));
+        } else {
+            info_str = g_strdup_printf("fd=%d", fd);
+        }
         break;
+    }
     default:
         error_setg(errp, "only support inet or fd type for local");
         return -1;
     }
 
-    s = net_dgram_fd_init_dgram(peer, model, name, fd, 0, NULL, errp);
+    s = net_dgram_fd_init_dgram(peer, model, name, fd, errp);
     if (!s) {
         return -1;
     }
 
+    pstrcpy(s->nc.info_str, sizeof(s->nc.info_str), info_str);
+    g_free(info_str);
+
     if (remote) {
         g_assert(s->dgram_dst == NULL);
         s->dgram_dst = dgram_dst;
-
-        pstrcpy(s->nc.info_str, sizeof(s->nc.info_str), info_str);
-        g_free(info_str);
     }
     return 0;
 }
-- 
2.36.1



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* [RFC PATCH v3 09/11] net: dgram: add unix socket
  2022-06-20 10:18 [RFC PATCH v3 00/11] qapi: net: add unix socket type support to netdev backend Laurent Vivier
                   ` (7 preceding siblings ...)
  2022-06-20 10:18 ` [RFC PATCH v3 08/11] net: dgram: move mcast specific code from net_socket_fd_init_dgram() Laurent Vivier
@ 2022-06-20 10:18 ` Laurent Vivier
  2022-06-20 10:18 ` [RFC PATCH v3 10/11] qemu-sockets: introduce socket_uri() Laurent Vivier
                   ` (2 subsequent siblings)
  11 siblings, 0 replies; 28+ messages in thread
From: Laurent Vivier @ 2022-06-20 10:18 UTC (permalink / raw)
  To: qemu-devel
  Cc: Markus Armbruster, Eric Blake, Dr. David Alan Gilbert,
	Paolo Bonzini, Daniel P. Berrangé,
	Jason Wang, Laurent Vivier, Stefano Brivio

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
---
 net/dgram.c | 65 ++++++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 62 insertions(+), 3 deletions(-)

diff --git a/net/dgram.c b/net/dgram.c
index c0cf0410792e..9f20bdbc163c 100644
--- a/net/dgram.c
+++ b/net/dgram.c
@@ -85,8 +85,15 @@ static ssize_t net_dgram_receive_dgram(NetClientState *nc,
 
     do {
         if (s->dgram_dst) {
-            ret = sendto(s->fd, buf, size, 0, s->dgram_dst,
-                         sizeof(struct sockaddr_in));
+            socklen_t len;
+
+            if (s->dgram_dst->sa_family == AF_INET) {
+                len = sizeof(struct sockaddr_in);
+            } else {
+                len = sizeof(struct sockaddr_un);
+            }
+
+            ret = sendto(s->fd, buf, size, 0, s->dgram_dst, len);
         } else {
             ret = send(s->fd, buf, size, 0);
         }
@@ -508,7 +515,7 @@ static int net_dgram_udp_init(NetClientState *peer,
         }
     } else {
         if (local->type != SOCKET_ADDRESS_TYPE_FD) {
-            error_setg(errp, "type=inet requires remote parameter");
+            error_setg(errp, "type=inet or unix require remote parameter");
             return -1;
         }
     }
@@ -558,6 +565,58 @@ static int net_dgram_udp_init(NetClientState *peer,
 
         break;
     }
+    case SOCKET_ADDRESS_TYPE_UNIX: {
+        struct sockaddr_un laddr_un, raddr_un;
+
+        ret = unlink(local->u.q_unix.path);
+        if (ret < 0 && errno != ENOENT) {
+            error_setg_errno(errp, errno, "failed to unlink socket %s",
+                             local->u.q_unix.path);
+            return -1;
+        }
+
+        laddr_un.sun_family = PF_UNIX;
+        ret = snprintf(laddr_un.sun_path, sizeof(laddr_un.sun_path), "%s",
+                       local->u.q_unix.path);
+        if (ret < 0 || ret >= sizeof(laddr_un.sun_path)) {
+            error_setg(errp, "UNIX socket path '%s' is too long",
+                       local->u.q_unix.path);
+            error_append_hint(errp, "Path must be less than %zu bytes\n",
+                              sizeof(laddr_un.sun_path));
+        }
+
+        raddr_un.sun_family = PF_UNIX;
+        ret = snprintf(raddr_un.sun_path, sizeof(raddr_un.sun_path), "%s",
+                       remote->u.q_unix.path);
+        if (ret < 0 || ret >= sizeof(raddr_un.sun_path)) {
+            error_setg(errp, "UNIX socket path '%s' is too long",
+                       remote->u.q_unix.path);
+            error_append_hint(errp, "Path must be less than %zu bytes\n",
+                              sizeof(raddr_un.sun_path));
+        }
+
+        fd = qemu_socket(PF_UNIX, SOCK_DGRAM, 0);
+        if (fd < 0) {
+            error_setg_errno(errp, errno, "can't create datagram socket");
+            return -1;
+        }
+
+        ret = bind(fd, (struct sockaddr *)&laddr_un, sizeof(laddr_un));
+        if (ret < 0) {
+            error_setg_errno(errp, errno, "can't bind unix=%s to socket",
+                             laddr_un.sun_path);
+            closesocket(fd);
+            return -1;
+        }
+        qemu_socket_set_nonblock(fd);
+
+        dgram_dst = g_malloc(sizeof(raddr_un));
+        memcpy(dgram_dst, &raddr_un, sizeof(raddr_un));
+
+        info_str = g_strdup_printf("udp=%s:%s",
+                                   laddr_un.sun_path, raddr_un.sun_path);
+        break;
+    }
     case SOCKET_ADDRESS_TYPE_FD: {
         SocketAddress *sa;
         SocketAddressType sa_type;
-- 
2.36.1



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* [RFC PATCH v3 10/11] qemu-sockets: introduce socket_uri()
  2022-06-20 10:18 [RFC PATCH v3 00/11] qapi: net: add unix socket type support to netdev backend Laurent Vivier
                   ` (8 preceding siblings ...)
  2022-06-20 10:18 ` [RFC PATCH v3 09/11] net: dgram: add unix socket Laurent Vivier
@ 2022-06-20 10:18 ` Laurent Vivier
  2022-06-20 10:18 ` [RFC PATCH v3 11/11] net: stream: move to QIO Laurent Vivier
  2022-06-20 18:24 ` [RFC PATCH v3 00/11] qapi: net: add unix socket type support to netdev backend Dr. David Alan Gilbert
  11 siblings, 0 replies; 28+ messages in thread
From: Laurent Vivier @ 2022-06-20 10:18 UTC (permalink / raw)
  To: qemu-devel
  Cc: Markus Armbruster, Eric Blake, Dr. David Alan Gilbert,
	Paolo Bonzini, Daniel P. Berrangé,
	Jason Wang, Laurent Vivier

Format a string URI from a SocketAddress.

Original code from hmp-cmds.c:SocketAddress_to_str()

Replace 'tcp:' by 'inet:' (because 'inet' can be also 'udp').
Replace 'tcp:' by 'vsock:' with vsock socket type.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
---
 include/qemu/sockets.h |  2 +-
 monitor/hmp-cmds.c     | 23 +----------------------
 util/qemu-sockets.c    | 20 ++++++++++++++++++++
 3 files changed, 22 insertions(+), 23 deletions(-)

diff --git a/include/qemu/sockets.h b/include/qemu/sockets.h
index 47194b9732f8..3e2ae7e21705 100644
--- a/include/qemu/sockets.h
+++ b/include/qemu/sockets.h
@@ -41,6 +41,7 @@ int unix_listen(const char *path, Error **errp);
 int unix_connect(const char *path, Error **errp);
 
 SocketAddress *socket_parse(const char *str, Error **errp);
+char *socket_uri(SocketAddress *addr);
 int socket_connect(SocketAddress *addr, Error **errp);
 int socket_listen(SocketAddress *addr, int num, Error **errp);
 void socket_listen_cleanup(int fd, Error **errp);
@@ -123,5 +124,4 @@ SocketAddress *socket_address_flatten(SocketAddressLegacy *addr);
  * Return 0 on success.
  */
 int socket_address_parse_named_fd(SocketAddress *addr, Error **errp);
-
 #endif /* QEMU_SOCKETS_H */
diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
index 622c783c32e1..dcea71210e30 100644
--- a/monitor/hmp-cmds.c
+++ b/monitor/hmp-cmds.c
@@ -195,27 +195,6 @@ void hmp_info_mice(Monitor *mon, const QDict *qdict)
     qapi_free_MouseInfoList(mice_list);
 }
 
-static char *SocketAddress_to_str(SocketAddress *addr)
-{
-    switch (addr->type) {
-    case SOCKET_ADDRESS_TYPE_INET:
-        return g_strdup_printf("tcp:%s:%s",
-                               addr->u.inet.host,
-                               addr->u.inet.port);
-    case SOCKET_ADDRESS_TYPE_UNIX:
-        return g_strdup_printf("unix:%s",
-                               addr->u.q_unix.path);
-    case SOCKET_ADDRESS_TYPE_FD:
-        return g_strdup_printf("fd:%s", addr->u.fd.str);
-    case SOCKET_ADDRESS_TYPE_VSOCK:
-        return g_strdup_printf("tcp:%s:%s",
-                               addr->u.vsock.cid,
-                               addr->u.vsock.port);
-    default:
-        return g_strdup("unknown address type");
-    }
-}
-
 void hmp_info_migrate(Monitor *mon, const QDict *qdict)
 {
     MigrationInfo *info;
@@ -373,7 +352,7 @@ void hmp_info_migrate(Monitor *mon, const QDict *qdict)
         monitor_printf(mon, "socket address: [\n");
 
         for (addr = info->socket_address; addr; addr = addr->next) {
-            char *s = SocketAddress_to_str(addr->value);
+            char *s = socket_uri(addr->value);
             monitor_printf(mon, "\t%s\n", s);
             g_free(s);
         }
diff --git a/util/qemu-sockets.c b/util/qemu-sockets.c
index 13b5b197f9ea..4efc2ce8b074 100644
--- a/util/qemu-sockets.c
+++ b/util/qemu-sockets.c
@@ -1098,6 +1098,26 @@ int unix_connect(const char *path, Error **errp)
     return sock;
 }
 
+char *socket_uri(SocketAddress *addr)
+{
+    switch (addr->type) {
+    case SOCKET_ADDRESS_TYPE_INET:
+        return g_strdup_printf("inet:%s:%s",
+                               addr->u.inet.host,
+                               addr->u.inet.port);
+    case SOCKET_ADDRESS_TYPE_UNIX:
+        return g_strdup_printf("unix:%s",
+                               addr->u.q_unix.path);
+    case SOCKET_ADDRESS_TYPE_FD:
+        return g_strdup_printf("fd:%s", addr->u.fd.str);
+    case SOCKET_ADDRESS_TYPE_VSOCK:
+        return g_strdup_printf("vsock:%s:%s",
+                               addr->u.vsock.cid,
+                               addr->u.vsock.port);
+    default:
+        return g_strdup("unknown address type");
+    }
+}
 
 SocketAddress *socket_parse(const char *str, Error **errp)
 {
-- 
2.36.1



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* [RFC PATCH v3 11/11] net: stream: move to QIO
  2022-06-20 10:18 [RFC PATCH v3 00/11] qapi: net: add unix socket type support to netdev backend Laurent Vivier
                   ` (9 preceding siblings ...)
  2022-06-20 10:18 ` [RFC PATCH v3 10/11] qemu-sockets: introduce socket_uri() Laurent Vivier
@ 2022-06-20 10:18 ` Laurent Vivier
  2022-06-20 18:24 ` [RFC PATCH v3 00/11] qapi: net: add unix socket type support to netdev backend Dr. David Alan Gilbert
  11 siblings, 0 replies; 28+ messages in thread
From: Laurent Vivier @ 2022-06-20 10:18 UTC (permalink / raw)
  To: qemu-devel
  Cc: Markus Armbruster, Eric Blake, Dr. David Alan Gilbert,
	Paolo Bonzini, Daniel P. Berrangé,
	Jason Wang, Laurent Vivier

Use QIOChannel, QIOChannelSocket and QIONetListener.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
---
 net/stream.c | 475 ++++++++++++++++++---------------------------------
 1 file changed, 165 insertions(+), 310 deletions(-)

diff --git a/net/stream.c b/net/stream.c
index dca50508ed84..d976fc37b60b 100644
--- a/net/stream.c
+++ b/net/stream.c
@@ -33,48 +33,36 @@
 #include "qemu/iov.h"
 #include "qemu/main-loop.h"
 #include "qemu/cutils.h"
+#include "io/channel.h"
+#include "io/channel-socket.h"
+#include "io/net-listener.h"
 
 typedef struct NetStreamState {
     NetClientState nc;
-    int listen_fd;
-    int fd;
+    QIOChannel *listen_ioc;
+    QIONetListener *listener;
+    QIOChannel *ioc;
+    guint ioc_read_tag;
+    guint ioc_write_tag;
     SocketReadState rs;
     unsigned int send_index;      /* number of bytes sent*/
-    IOHandler *send_fn;
-    bool read_poll;               /* waiting to receive data? */
-    bool write_poll;              /* waiting to transmit data? */
 } NetStreamState;
 
-static void net_stream_accept(void *opaque);
-static void net_stream_writable(void *opaque);
+static void net_stream_listen(QIONetListener *listener,
+                              QIOChannelSocket *cioc,
+                              void *opaque);
 
-static void net_stream_update_fd_handler(NetStreamState *s)
+static gboolean net_stream_writable(QIOChannel *ioc,
+                                    GIOCondition condition,
+                                    gpointer data)
 {
-    qemu_set_fd_handler(s->fd,
-                        s->read_poll ? s->send_fn : NULL,
-                        s->write_poll ? net_stream_writable : NULL,
-                        s);
-}
-
-static void net_stream_read_poll(NetStreamState *s, bool enable)
-{
-    s->read_poll = enable;
-    net_stream_update_fd_handler(s);
-}
-
-static void net_stream_write_poll(NetStreamState *s, bool enable)
-{
-    s->write_poll = enable;
-    net_stream_update_fd_handler(s);
-}
-
-static void net_stream_writable(void *opaque)
-{
-    NetStreamState *s = opaque;
+    NetStreamState *s = data;
 
-    net_stream_write_poll(s, false);
+    s->ioc_write_tag = 0;
 
     qemu_flush_queued_packets(&s->nc);
+
+    return G_SOURCE_REMOVE;
 }
 
 static ssize_t net_stream_receive(NetClientState *nc, const uint8_t *buf,
@@ -91,12 +79,15 @@ static ssize_t net_stream_receive(NetClientState *nc, const uint8_t *buf,
             .iov_len  = size,
         },
     };
+    struct iovec local_iov[2];
+    unsigned int nlocal_iov;
     size_t remaining;
     ssize_t ret;
 
-    remaining = iov_size(iov, 2) - s->send_index;
-    ret = iov_send(s->fd, iov, 2, s->send_index, remaining);
 
+    remaining = iov_size(iov, 2) - s->send_index;
+    nlocal_iov = iov_copy(local_iov, 2, iov, 2, s->send_index, remaining);
+    ret = qio_channel_writev(s->ioc, local_iov, nlocal_iov, NULL);
     if (ret == -1 && errno == EAGAIN) {
         ret = 0; /* handled further down */
     }
@@ -106,19 +97,25 @@ static ssize_t net_stream_receive(NetClientState *nc, const uint8_t *buf,
     }
     if (ret < (ssize_t)remaining) {
         s->send_index += ret;
-        net_stream_write_poll(s, true);
+        s->ioc_write_tag = qio_channel_add_watch(s->ioc, G_IO_OUT,
+                                                 net_stream_writable, s, NULL);
         return 0;
     }
     s->send_index = 0;
     return size;
 }
 
+static gboolean net_stream_send(QIOChannel *ioc,
+                                GIOCondition condition,
+                                gpointer data);
+
 static void net_stream_send_completed(NetClientState *nc, ssize_t len)
 {
     NetStreamState *s = DO_UPCAST(NetStreamState, nc, nc);
 
-    if (!s->read_poll) {
-        net_stream_read_poll(s, true);
+    if (!s->ioc_read_tag) {
+        s->ioc_read_tag = qio_channel_add_watch(s->ioc, G_IO_IN,
+                                                net_stream_send, s, NULL);
     }
 }
 
@@ -129,19 +126,24 @@ static void net_stream_rs_finalize(SocketReadState *rs)
     if (qemu_send_packet_async(&s->nc, rs->buf,
                                rs->packet_len,
                                net_stream_send_completed) == 0) {
-        net_stream_read_poll(s, false);
+        if (s->ioc_read_tag) {
+            g_source_remove(s->ioc_read_tag);
+            s->ioc_read_tag = 0;
+        }
     }
 }
 
-static void net_stream_send(void *opaque)
+static gboolean net_stream_send(QIOChannel *ioc,
+                                GIOCondition condition,
+                                gpointer data)
 {
-    NetStreamState *s = opaque;
+    NetStreamState *s = data;
     int size;
     int ret;
-    uint8_t buf1[NET_BUFSIZE];
-    const uint8_t *buf;
+    char buf1[NET_BUFSIZE];
+    const char *buf;
 
-    size = recv(s->fd, buf1, sizeof(buf1), 0);
+    size = qio_channel_read(s->ioc, buf1, sizeof(buf1), NULL);
     if (size < 0) {
         if (errno != EWOULDBLOCK) {
             goto eoc;
@@ -149,52 +151,63 @@ static void net_stream_send(void *opaque)
     } else if (size == 0) {
         /* end of connection */
     eoc:
-        net_stream_read_poll(s, false);
-        net_stream_write_poll(s, false);
-        if (s->listen_fd != -1) {
-            qemu_set_fd_handler(s->listen_fd, net_stream_accept, NULL, s);
+        s->ioc_read_tag = 0;
+        if (s->ioc_write_tag) {
+            g_source_remove(s->ioc_write_tag);
+            s->ioc_write_tag = 0;
+        }
+        if (s->listener) {
+            qio_net_listener_set_client_func(s->listener, net_stream_listen,
+                                             s, NULL);
         }
-        closesocket(s->fd);
+        object_unref(OBJECT(s->ioc));
+        s->ioc = NULL;
 
-        s->fd = -1;
         net_socket_rs_init(&s->rs, net_stream_rs_finalize, false);
         s->nc.link_down = true;
         memset(s->nc.info_str, 0, sizeof(s->nc.info_str));
 
-        return;
+        return G_SOURCE_REMOVE;
     }
     buf = buf1;
 
-    ret = net_fill_rstate(&s->rs, buf, size);
+    ret = net_fill_rstate(&s->rs, (const uint8_t *)buf, size);
 
     if (ret == -1) {
         goto eoc;
     }
+
+    return G_SOURCE_CONTINUE;
 }
 
 static void net_stream_cleanup(NetClientState *nc)
 {
     NetStreamState *s = DO_UPCAST(NetStreamState, nc, nc);
-    if (s->fd != -1) {
-        net_stream_read_poll(s, false);
-        net_stream_write_poll(s, false);
-        close(s->fd);
-        s->fd = -1;
+    if (s->ioc) {
+        if (QIO_CHANNEL_SOCKET(s->ioc)->fd != -1) {
+            if (s->ioc_read_tag) {
+                g_source_remove(s->ioc_read_tag);
+                s->ioc_read_tag = 0;
+            }
+            if (s->ioc_write_tag) {
+                g_source_remove(s->ioc_write_tag);
+                s->ioc_write_tag = 0;
+            }
+        }
+        object_unref(OBJECT(s->ioc));
+        s->ioc = NULL;
     }
-    if (s->listen_fd != -1) {
-        qemu_set_fd_handler(s->listen_fd, NULL, NULL, NULL);
-        closesocket(s->listen_fd);
-        s->listen_fd = -1;
+    if (s->listen_ioc) {
+        if (s->listener) {
+            qio_net_listener_disconnect(s->listener);
+            object_unref(OBJECT(s->listener));
+            s->listener = NULL;
+        }
+        object_unref(OBJECT(s->listen_ioc));
+        s->listen_ioc = NULL;
     }
 }
 
-static void net_stream_connect(void *opaque)
-{
-    NetStreamState *s = opaque;
-    s->send_fn = net_stream_send;
-    net_stream_read_poll(s, true);
-}
-
 static NetClientInfo net_stream_info = {
     .type = NET_CLIENT_DRIVER_STREAM,
     .size = sizeof(NetStreamState),
@@ -202,77 +215,64 @@ static NetClientInfo net_stream_info = {
     .cleanup = net_stream_cleanup,
 };
 
-static NetStreamState *net_stream_fd_init_stream(NetClientState *peer,
-                                                 const char *model,
-                                                 const char *name,
-                                                 int fd, int is_connected)
+static void net_stream_listen(QIONetListener *listener,
+                              QIOChannelSocket *cioc,
+                              void *opaque)
 {
-    NetClientState *nc;
-    NetStreamState *s;
+    NetStreamState *s = opaque;
+    SocketAddress *addr;
+    char *uri;
 
-    nc = qemu_new_net_client(&net_stream_info, peer, model, name);
+    object_ref(OBJECT(cioc));
 
-    snprintf(nc->info_str, sizeof(nc->info_str), "fd=%d", fd);
+    qio_net_listener_set_client_func(s->listener, NULL, s, NULL);
 
-    s = DO_UPCAST(NetStreamState, nc, nc);
+    s->ioc = QIO_CHANNEL(cioc);
+    qio_channel_set_name(s->ioc, "stream-server");
+    s->nc.link_down = false;
 
-    s->fd = fd;
-    s->listen_fd = -1;
-    net_socket_rs_init(&s->rs, net_stream_rs_finalize, false);
+    s->ioc_read_tag = qio_channel_add_watch(s->ioc, G_IO_IN, net_stream_send,
+                                            s, NULL);
 
-    /* Disable Nagle algorithm on TCP sockets to reduce latency */
-    socket_set_nodelay(fd);
+    addr = qio_channel_socket_get_remote_address(cioc, NULL);
+    g_assert(addr != NULL);
+    uri = socket_uri(addr);
+    pstrcpy(s->nc.info_str, sizeof(s->nc.info_str), uri);
+    g_free(uri);
+    qapi_free_SocketAddress(addr);
 
-    if (is_connected) {
-        net_stream_connect(s);
-    } else {
-        qemu_set_fd_handler(s->fd, NULL, net_stream_connect, s);
-    }
-    return s;
 }
 
-static void net_stream_accept(void *opaque)
+static void net_stream_server_listening(QIOTask *task, gpointer opaque)
 {
     NetStreamState *s = opaque;
-    struct sockaddr_storage saddr;
-    socklen_t len;
-    int fd;
-
-    for (;;) {
-        len = sizeof(saddr);
-        fd = qemu_accept(s->listen_fd, (struct sockaddr *)&saddr, &len);
-        if (fd < 0 && errno != EINTR) {
-            return;
-        } else if (fd >= 0) {
-            qemu_set_fd_handler(s->listen_fd, NULL, NULL, NULL);
-            break;
-        }
-    }
-
-    s->fd = fd;
-    s->nc.link_down = false;
-    net_stream_connect(s);
-    switch (saddr.ss_family) {
-    case AF_INET: {
-        struct sockaddr_in *saddr_in = (struct sockaddr_in *)&saddr;
+    QIOChannelSocket *listen_sioc = QIO_CHANNEL_SOCKET(s->listen_ioc);
+    SocketAddress *addr;
+    int ret;
 
-        snprintf(s->nc.info_str, sizeof(s->nc.info_str),
-                 "connection from %s:%d",
-                 inet_ntoa(saddr_in->sin_addr), ntohs(saddr_in->sin_port));
-        break;
+    if (listen_sioc->fd < 0) {
+        snprintf(s->nc.info_str, sizeof(s->nc.info_str), "connection error");
+        return;
     }
-    case AF_UNIX: {
-        struct sockaddr_un saddr_un;
 
-        len = sizeof(saddr_un);
-        getsockname(s->listen_fd, (struct sockaddr *)&saddr_un, &len);
+    addr = qio_channel_socket_get_local_address(listen_sioc, NULL);
+    g_assert(addr != NULL);
+    ret = qemu_socket_try_set_nonblock(listen_sioc->fd);
+    if (addr->type == SOCKET_ADDRESS_TYPE_FD && ret < 0) {
         snprintf(s->nc.info_str, sizeof(s->nc.info_str),
-                 "connect from %s", saddr_un.sun_path);
-        break;
-    }
-    default:
-        g_assert_not_reached();
+                 "can't use file descriptor %s (errno %d)",
+                 addr->u.fd.str, -ret);
+        return;
     }
+    g_assert(ret == 0);
+    qapi_free_SocketAddress(addr);
+
+    s->nc.link_down = true;
+    s->listener = qio_net_listener_new();
+
+    net_socket_rs_init(&s->rs, net_stream_rs_finalize, false);
+    qio_net_listener_set_client_func(s->listener, net_stream_listen, s, NULL);
+    qio_net_listener_add(s->listener, listen_sioc);
 }
 
 static int net_stream_server_init(NetClientState *peer,
@@ -283,103 +283,55 @@ static int net_stream_server_init(NetClientState *peer,
 {
     NetClientState *nc;
     NetStreamState *s;
-    int fd, ret;
+    QIOChannelSocket *listen_sioc = qio_channel_socket_new();
 
-    switch (addr->type) {
-    case SOCKET_ADDRESS_TYPE_INET: {
-        struct sockaddr_in saddr_in;
+    nc = qemu_new_net_client(&net_stream_info, peer, model, name);
+    s = DO_UPCAST(NetStreamState, nc, nc);
 
-        if (convert_host_port(&saddr_in, addr->u.inet.host, addr->u.inet.port,
-                              errp) < 0) {
-            return -1;
-        }
+    s->listen_ioc = QIO_CHANNEL(listen_sioc);
+    qio_channel_socket_listen_async(listen_sioc, addr, 0,
+                                    net_stream_server_listening, s,
+                                    NULL, NULL);
 
-        fd = qemu_socket(PF_INET, SOCK_STREAM, 0);
-        if (fd < 0) {
-            error_setg_errno(errp, errno, "can't create stream socket");
-            return -1;
-        }
-        qemu_socket_set_nonblock(fd);
+    return 0;
+}
 
-        socket_set_fast_reuse(fd);
+static void net_stream_client_connected(QIOTask *task, gpointer opaque)
+{
+    NetStreamState *s = opaque;
+    QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(s->ioc);
+    SocketAddress *addr;
+    gchar *uri;
+    int ret;
 
-        ret = bind(fd, (struct sockaddr *)&saddr_in, sizeof(saddr_in));
-        if (ret < 0) {
-            error_setg_errno(errp, errno, "can't bind ip=%s to socket",
-                             inet_ntoa(saddr_in.sin_addr));
-            closesocket(fd);
-            return -1;
-        }
-        break;
+    if (sioc->fd < 0) {
+        snprintf(s->nc.info_str, sizeof(s->nc.info_str), "connection error");
+        return;
     }
-    case SOCKET_ADDRESS_TYPE_UNIX: {
-        struct sockaddr_un saddr_un;
-
-        ret = unlink(addr->u.q_unix.path);
-        if (ret < 0 && errno != ENOENT) {
-            error_setg_errno(errp, errno, "failed to unlink socket %s",
-                             addr->u.q_unix.path);
-            return -1;
-        }
-
-        saddr_un.sun_family = PF_UNIX;
-        ret = snprintf(saddr_un.sun_path, sizeof(saddr_un.sun_path), "%s",
-                       addr->u.q_unix.path);
-        if (ret < 0 || ret >= sizeof(saddr_un.sun_path)) {
-            error_setg(errp, "UNIX socket path '%s' is too long",
-                       addr->u.q_unix.path);
-            error_append_hint(errp, "Path must be less than %zu bytes\n",
-                              sizeof(saddr_un.sun_path));
-        }
 
-        fd = qemu_socket(PF_UNIX, SOCK_STREAM, 0);
-        if (fd < 0) {
-            error_setg_errno(errp, errno, "can't create stream socket");
-            return -1;
-        }
-        qemu_socket_set_nonblock(fd);
-
-        ret = bind(fd, (struct sockaddr *)&saddr_un, sizeof(saddr_un));
-        if (ret < 0) {
-            error_setg_errno(errp, errno, "can't create socket with path: %s",
-                             saddr_un.sun_path);
-            closesocket(fd);
-            return -1;
-        }
-        break;
-    }
-    case SOCKET_ADDRESS_TYPE_FD:
-        fd = monitor_fd_param(monitor_cur(), addr->u.fd.str, errp);
-        if (fd == -1) {
-            return -1;
-        }
-        ret = qemu_socket_try_set_nonblock(fd);
-        if (ret < 0) {
-            error_setg_errno(errp, -ret, "%s: Can't use file descriptor %d",
-                             name, fd);
-            return -1;
-        }
-        break;
-    default:
-        g_assert_not_reached();
-    }
+    addr = qio_channel_socket_get_remote_address(sioc, NULL);
+    g_assert(addr != NULL);
+    uri = socket_uri(addr);
+    pstrcpy(s->nc.info_str, sizeof(s->nc.info_str), uri);
+    g_free(uri);
 
-    ret = listen(fd, 0);
-    if (ret < 0) {
-        error_setg_errno(errp, errno, "can't listen on socket");
-        closesocket(fd);
-        return -1;
+    ret = qemu_socket_try_set_nonblock(sioc->fd);
+    if (addr->type == SOCKET_ADDRESS_TYPE_FD && ret < 0) {
+        snprintf(s->nc.info_str, sizeof(s->nc.info_str),
+                 "can't use file descriptor %s (errno %d)",
+                 addr->u.fd.str, -ret);
+        return;
     }
+    g_assert(ret == 0);
+    qapi_free_SocketAddress(addr);
 
-    nc = qemu_new_net_client(&net_stream_info, peer, model, name);
-    s = DO_UPCAST(NetStreamState, nc, nc);
-    s->fd = -1;
-    s->listen_fd = fd;
-    s->nc.link_down = true;
     net_socket_rs_init(&s->rs, net_stream_rs_finalize, false);
 
-    qemu_set_fd_handler(s->listen_fd, net_stream_accept, NULL, s);
-    return 0;
+    /* Disable Nagle algorithm on TCP sockets to reduce latency */
+    qio_channel_set_delay(s->ioc, false);
+
+    s->ioc_read_tag = qio_channel_add_watch(s->ioc, G_IO_IN, net_stream_send,
+                                            s, NULL);
 }
 
 static int net_stream_client_init(NetClientState *peer,
@@ -389,114 +341,17 @@ static int net_stream_client_init(NetClientState *peer,
                                   Error **errp)
 {
     NetStreamState *s;
-    int fd, connected, ret;
-    gchar *info_str;
-
-    switch (addr->type) {
-    case SOCKET_ADDRESS_TYPE_INET: {
-        struct sockaddr_in saddr_in;
-
-        if (convert_host_port(&saddr_in, addr->u.inet.host, addr->u.inet.port,
-                              errp) < 0) {
-            return -1;
-        }
-
-        fd = qemu_socket(PF_INET, SOCK_STREAM, 0);
-        if (fd < 0) {
-            error_setg_errno(errp, errno, "can't create stream socket");
-            return -1;
-        }
-        qemu_socket_set_nonblock(fd);
-
-        connected = 0;
-        for (;;) {
-            ret = connect(fd, (struct sockaddr *)&saddr_in, sizeof(saddr_in));
-            if (ret < 0) {
-                if (errno == EINTR || errno == EWOULDBLOCK) {
-                    /* continue */
-                } else if (errno == EINPROGRESS ||
-                           errno == EALREADY) {
-                    break;
-                } else {
-                    error_setg_errno(errp, errno, "can't connect socket");
-                    closesocket(fd);
-                    return -1;
-                }
-            } else {
-                connected = 1;
-                break;
-            }
-        }
-        info_str = g_strdup_printf("connect to %s:%d",
-                                   inet_ntoa(saddr_in.sin_addr),
-                                   ntohs(saddr_in.sin_port));
-        break;
-    }
-    case SOCKET_ADDRESS_TYPE_UNIX: {
-        struct sockaddr_un saddr_un;
-
-        saddr_un.sun_family = PF_UNIX;
-        ret = snprintf(saddr_un.sun_path, sizeof(saddr_un.sun_path), "%s",
-                       addr->u.q_unix.path);
-        if (ret < 0 || ret >= sizeof(saddr_un.sun_path)) {
-            error_setg(errp, "UNIX socket path '%s' is too long",
-                       addr->u.q_unix.path);
-            error_append_hint(errp, "Path must be less than %zu bytes\n",
-                              sizeof(saddr_un.sun_path));
-        }
+    NetClientState *nc;
+    QIOChannelSocket *sioc = qio_channel_socket_new();
 
-        fd = qemu_socket(PF_UNIX, SOCK_STREAM, 0);
-        if (fd < 0) {
-            error_setg_errno(errp, errno, "can't create stream socket");
-            return -1;
-        }
-        qemu_socket_set_nonblock(fd);
-
-        connected = 0;
-        for (;;) {
-            ret = connect(fd, (struct sockaddr *)&saddr_un, sizeof(saddr_un));
-            if (ret < 0) {
-                if (errno == EINTR || errno == EWOULDBLOCK) {
-                    /* continue */
-                } else if (errno == EAGAIN ||
-                           errno == EALREADY) {
-                    break;
-                } else {
-                    error_setg_errno(errp, errno, "can't connect socket");
-                    closesocket(fd);
-                    return -1;
-                }
-            } else {
-                connected = 1;
-                break;
-            }
-        }
-        info_str = g_strdup_printf(" connect to %s", saddr_un.sun_path);
-        break;
-    }
-    case SOCKET_ADDRESS_TYPE_FD:
-        fd = monitor_fd_param(monitor_cur(), addr->u.fd.str, errp);
-        if (fd == -1) {
-            return -1;
-        }
-        ret = qemu_socket_try_set_nonblock(fd);
-        if (ret < 0) {
-            error_setg_errno(errp, -ret, "%s: Can't use file descriptor %d",
-                             name, fd);
-            return -1;
-        }
-        connected = 1;
-        info_str = g_strdup_printf("connect to fd %d", fd);
-        break;
-    default:
-        error_setg(errp, "only support inet, unix or fd type");
-        return -1;
-    }
+    nc = qemu_new_net_client(&net_stream_info, peer, model, name);
+    s = DO_UPCAST(NetStreamState, nc, nc);
 
-    s = net_stream_fd_init_stream(peer, model, name, fd, connected);
+    s->ioc = QIO_CHANNEL(sioc);
 
-    pstrcpy(s->nc.info_str, sizeof(s->nc.info_str), info_str);
-    g_free(info_str);
+    qio_channel_socket_connect_async(sioc, addr,
+                                     net_stream_client_connected, s,
+                                     NULL, NULL);
 
     return 0;
 }
-- 
2.36.1



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* Re: [RFC PATCH v3 02/11] net: remove the @errp argument of net_client_inits()
  2022-06-20 10:18 ` [RFC PATCH v3 02/11] net: remove the @errp argument of net_client_inits() Laurent Vivier
@ 2022-06-20 11:39   ` Markus Armbruster
  0 siblings, 0 replies; 28+ messages in thread
From: Markus Armbruster @ 2022-06-20 11:39 UTC (permalink / raw)
  To: Laurent Vivier
  Cc: qemu-devel, Eric Blake, Dr. David Alan Gilbert, Paolo Bonzini,
	Daniel P. Berrangé,
	Jason Wang

Laurent Vivier <lvivier@redhat.com> writes:

> The only caller passes &error_fatal, so use this directly in the function.
>
> It's what we do for -blockdev, -device, and -object.
>
> Signed-off-by: Laurent Vivier <lvivier@redhat.com>

Reviewed-by: Markus Armbruster <armbru@redhat.com>



^ permalink raw reply	[flat|nested] 28+ messages in thread

* Re: [RFC PATCH v3 03/11] qapi: net: introduce a way to bypass qemu_opts_parse_noisily()
  2022-06-20 10:18 ` [RFC PATCH v3 03/11] qapi: net: introduce a way to bypass qemu_opts_parse_noisily() Laurent Vivier
@ 2022-06-20 12:43   ` Markus Armbruster
  2022-06-20 13:46     ` Laurent Vivier
  2022-06-22  8:00   ` Markus Armbruster
  1 sibling, 1 reply; 28+ messages in thread
From: Markus Armbruster @ 2022-06-20 12:43 UTC (permalink / raw)
  To: Laurent Vivier
  Cc: qemu-devel, Eric Blake, Dr. David Alan Gilbert, Paolo Bonzini,
	Daniel P. Berrangé,
	Jason Wang

Laurent Vivier <lvivier@redhat.com> writes:

> As qemu_opts_parse_noisily() flattens the QAPI structures ("type" field
> of Netdev structure can collides with "type" field of SocketAddress),
> we introduce a way to bypass qemu_opts_parse_noisily() and use directly
> visit_type_Netdev() to parse the backend parameters.
>
> More details from Markus:
>
> qemu_init() passes the argument of -netdev, -nic, and -net to
> net_client_parse().
>
> net_client_parse() parses with qemu_opts_parse_noisily(), passing
> QemuOptsList qemu_netdev_opts for -netdev, qemu_nic_opts for -nic, and
> qemu_net_opts for -net.  Their desc[] are all empty, which means any
> keys are accepted.  The result of the parse (a QemuOpts) is stored in
> the QemuOptsList.
>
> Note that QemuOpts is flat by design.  In some places, we layer non-flat
> on top using dotted keys convention, but not here.
>
> net_init_clients() iterates over the stored QemuOpts, and passes them to
> net_init_netdev(), net_param_nic(), or net_init_client(), respectively.
>
> These functions pass the QemuOpts to net_client_init().  They also do
> other things with the QemuOpts, which we can ignore here.
>
> net_client_init() uses the opts visitor to convert the (flat) QemOpts to
> a (non-flat) QAPI object Netdev.  Netdev is also the argument of QMP
> command netdev_add.
>
> The opts visitor was an early attempt to support QAPI in
> (QemuOpts-based) CLI.  It restricts QAPI types to a certain shape; see
> commit eb7ee2cbeb "qapi: introduce OptsVisitor".
>
> A more modern way to support QAPI is qobject_input_visitor_new_str().
> It uses keyval_parse() instead of QemuOpts for KEY=VALUE,... syntax, and
> it also supports JSON syntax.  The former isn't quite as expressive as
> JSON, but it's a lot closer than QemuOpts + opts visitor.
>
> This commit paves the way to use of the modern way instead.
>
> Signed-off-by: Laurent Vivier <lvivier@redhat.com>
> ---
>  include/net/net.h |  1 +
>  net/net.c         | 60 +++++++++++++++++++++++++++++++++++++++++++++++
>  softmmu/vl.c      |  3 ++-
>  3 files changed, 63 insertions(+), 1 deletion(-)
>
> diff --git a/include/net/net.h b/include/net/net.h
> index c53c64ac18c4..4ae8ed480f73 100644
> --- a/include/net/net.h
> +++ b/include/net/net.h
> @@ -214,6 +214,7 @@ extern NICInfo nd_table[MAX_NICS];
>  extern const char *host_net_devices[];
>  
>  /* from net.c */
> +int netdev_parse_modern(const char *optarg);
>  int net_client_parse(QemuOptsList *opts_list, const char *str);
>  void show_netdevs(void);
>  void net_init_clients(void);
> diff --git a/net/net.c b/net/net.c
> index 15958f881776..c337d3d753fe 100644
> --- a/net/net.c
> +++ b/net/net.c
> @@ -54,6 +54,7 @@
>  #include "net/colo-compare.h"
>  #include "net/filter.h"
>  #include "qapi/string-output-visitor.h"
> +#include "qapi/qobject-input-visitor.h"
>  
>  /* Net bridge is currently not supported for W32. */
>  #if !defined(_WIN32)
> @@ -63,6 +64,16 @@
>  static VMChangeStateEntry *net_change_state_entry;
>  static QTAILQ_HEAD(, NetClientState) net_clients;
>  
> +typedef struct NetdevQueueEntry {
> +    Netdev *nd;
> +    Location loc;
> +    QSIMPLEQ_ENTRY(NetdevQueueEntry) entry;
> +} NetdevQueueEntry;
> +
> +typedef QSIMPLEQ_HEAD(, NetdevQueueEntry) NetdevQueue;
> +
> +static NetdevQueue nd_queue = QSIMPLEQ_HEAD_INITIALIZER(nd_queue);
> +
>  /***********************************************************/
>  /* network device redirectors */
>  
> @@ -1562,6 +1573,20 @@ out:
>      return ret;
>  }
>  
> +static void netdev_init_modern(void)
> +{
> +    while (!QSIMPLEQ_EMPTY(&nd_queue)) {
> +        NetdevQueueEntry *nd = QSIMPLEQ_FIRST(&nd_queue);
> +
> +        QSIMPLEQ_REMOVE_HEAD(&nd_queue, entry);
> +        loc_push_restore(&nd->loc);
> +        net_client_init1(nd->nd, true, &error_fatal);
> +        loc_pop(&nd->loc);
> +        qapi_free_Netdev(nd->nd);
> +        g_free(nd);
> +    }
> +}
> +
>  void net_init_clients(void)
>  {
>      net_change_state_entry =
> @@ -1569,6 +1594,8 @@ void net_init_clients(void)
>  
>      QTAILQ_INIT(&net_clients);
>  
> +    netdev_init_modern();
> +
>      qemu_opts_foreach(qemu_find_opts("netdev"), net_init_netdev, NULL,
>                        &error_fatal);
>  
> @@ -1579,6 +1606,39 @@ void net_init_clients(void)
>                        &error_fatal);
>  }
>  
> +/*
> + * netdev_is_modern() returns true when the backend needs to bypass
> + * qemu_opts_parse_noisily()
> + */
> +static bool netdev_is_modern(const char *optarg)
> +{
> +    return false;
> +}
> +
> +/*
> + * netdev_parse_modern() uses modern, more expressive syntax than
> + * net_client_parse(), supports only the netdev option.
> + */
> +int netdev_parse_modern(const char *optarg)
> +{
> +    Visitor *v;
> +    NetdevQueueEntry *nd;
> +
> +    if (!netdev_is_modern(optarg)) {
> +        return -1;
> +    }
> +
> +    v = qobject_input_visitor_new_str(optarg, "type", &error_fatal);
> +    nd = g_new(NetdevQueueEntry, 1);
> +    visit_type_Netdev(v, NULL, &nd->nd, &error_fatal);
> +    visit_free(v);
> +    loc_save(&nd->loc);
> +
> +    QSIMPLEQ_INSERT_TAIL(&nd_queue, nd, entry);
> +
> +    return 0;
> +}
> +
>  int net_client_parse(QemuOptsList *opts_list, const char *optarg)
>  {
>      if (!qemu_opts_parse_noisily(opts_list, optarg, true)) {
> diff --git a/softmmu/vl.c b/softmmu/vl.c
> index 8eed0f31c073..838f5b48c447 100644
> --- a/softmmu/vl.c
> +++ b/softmmu/vl.c
> @@ -2839,7 +2839,8 @@ void qemu_init(int argc, char **argv, char **envp)
>                  break;
>              case QEMU_OPTION_netdev:
>                  default_net = 0;
> -                if (net_client_parse(qemu_find_opts("netdev"), optarg) == -1) {
> +                if (netdev_parse_modern(optarg) == -1 &&
> +                    net_client_parse(qemu_find_opts("netdev"), optarg) == -1) {
>                      exit(1);
>                  }
>                  break;

To make this work, netdev_parse_modern() must

* either succeeed, or

* fail without reporting an error, or

* report an error and exit()

Recommend to spell that out in its function comment.

Alternatively:

                   if (netdev_is_modern(optarg)) {
                       netdev_parse_modern(optarg);
                   } else {
                       if (net_client_parse(qemu_find_opts("netdev"), optarg) == -1) {
                           exit(1);
                       }
                   }

netdev_is_modern() needs external linkage, and netdev_parse_modern()
loses its return value.

Note that all callers net_client_parse() handle failure exactly the same
way.  If we let net_client_parse() exit(), then this becomes

                   if (netdev_is_modern(optarg)) {
                       netdev_parse_modern(optarg);
                   } else {
                       net_client_parse(qemu_find_opts("netdev"), optarg);
                   }

I like this one best.  What do you think?

Regardless of which alternative we pick: error reporting depends on
netdev_is_modern().  To be discussed in my review of the next patch.



^ permalink raw reply	[flat|nested] 28+ messages in thread

* Re: [RFC PATCH v3 03/11] qapi: net: introduce a way to bypass qemu_opts_parse_noisily()
  2022-06-20 12:43   ` Markus Armbruster
@ 2022-06-20 13:46     ` Laurent Vivier
  0 siblings, 0 replies; 28+ messages in thread
From: Laurent Vivier @ 2022-06-20 13:46 UTC (permalink / raw)
  To: Markus Armbruster
  Cc: qemu-devel, Eric Blake, Dr. David Alan Gilbert, Paolo Bonzini,
	Daniel P. Berrangé,
	Jason Wang

On 20/06/2022 14:43, Markus Armbruster wrote:
> Laurent Vivier <lvivier@redhat.com> writes:
> 
>> As qemu_opts_parse_noisily() flattens the QAPI structures ("type" field
>> of Netdev structure can collides with "type" field of SocketAddress),
>> we introduce a way to bypass qemu_opts_parse_noisily() and use directly
>> visit_type_Netdev() to parse the backend parameters.
>>
>> More details from Markus:
>>
>> qemu_init() passes the argument of -netdev, -nic, and -net to
>> net_client_parse().
>>
>> net_client_parse() parses with qemu_opts_parse_noisily(), passing
>> QemuOptsList qemu_netdev_opts for -netdev, qemu_nic_opts for -nic, and
>> qemu_net_opts for -net.  Their desc[] are all empty, which means any
>> keys are accepted.  The result of the parse (a QemuOpts) is stored in
>> the QemuOptsList.
>>
>> Note that QemuOpts is flat by design.  In some places, we layer non-flat
>> on top using dotted keys convention, but not here.
>>
>> net_init_clients() iterates over the stored QemuOpts, and passes them to
>> net_init_netdev(), net_param_nic(), or net_init_client(), respectively.
>>
>> These functions pass the QemuOpts to net_client_init().  They also do
>> other things with the QemuOpts, which we can ignore here.
>>
>> net_client_init() uses the opts visitor to convert the (flat) QemOpts to
>> a (non-flat) QAPI object Netdev.  Netdev is also the argument of QMP
>> command netdev_add.
>>
>> The opts visitor was an early attempt to support QAPI in
>> (QemuOpts-based) CLI.  It restricts QAPI types to a certain shape; see
>> commit eb7ee2cbeb "qapi: introduce OptsVisitor".
>>
>> A more modern way to support QAPI is qobject_input_visitor_new_str().
>> It uses keyval_parse() instead of QemuOpts for KEY=VALUE,... syntax, and
>> it also supports JSON syntax.  The former isn't quite as expressive as
>> JSON, but it's a lot closer than QemuOpts + opts visitor.
>>
>> This commit paves the way to use of the modern way instead.
>>
>> Signed-off-by: Laurent Vivier <lvivier@redhat.com>
>> ---
>>   include/net/net.h |  1 +
>>   net/net.c         | 60 +++++++++++++++++++++++++++++++++++++++++++++++
>>   softmmu/vl.c      |  3 ++-
>>   3 files changed, 63 insertions(+), 1 deletion(-)
>>
>> diff --git a/include/net/net.h b/include/net/net.h
>> index c53c64ac18c4..4ae8ed480f73 100644
>> --- a/include/net/net.h
>> +++ b/include/net/net.h
>> @@ -214,6 +214,7 @@ extern NICInfo nd_table[MAX_NICS];
>>   extern const char *host_net_devices[];
>>   
>>   /* from net.c */
>> +int netdev_parse_modern(const char *optarg);
>>   int net_client_parse(QemuOptsList *opts_list, const char *str);
>>   void show_netdevs(void);
>>   void net_init_clients(void);
>> diff --git a/net/net.c b/net/net.c
>> index 15958f881776..c337d3d753fe 100644
>> --- a/net/net.c
>> +++ b/net/net.c
>> @@ -54,6 +54,7 @@
>>   #include "net/colo-compare.h"
>>   #include "net/filter.h"
>>   #include "qapi/string-output-visitor.h"
>> +#include "qapi/qobject-input-visitor.h"
>>   
>>   /* Net bridge is currently not supported for W32. */
>>   #if !defined(_WIN32)
>> @@ -63,6 +64,16 @@
>>   static VMChangeStateEntry *net_change_state_entry;
>>   static QTAILQ_HEAD(, NetClientState) net_clients;
>>   
>> +typedef struct NetdevQueueEntry {
>> +    Netdev *nd;
>> +    Location loc;
>> +    QSIMPLEQ_ENTRY(NetdevQueueEntry) entry;
>> +} NetdevQueueEntry;
>> +
>> +typedef QSIMPLEQ_HEAD(, NetdevQueueEntry) NetdevQueue;
>> +
>> +static NetdevQueue nd_queue = QSIMPLEQ_HEAD_INITIALIZER(nd_queue);
>> +
>>   /***********************************************************/
>>   /* network device redirectors */
>>   
>> @@ -1562,6 +1573,20 @@ out:
>>       return ret;
>>   }
>>   
>> +static void netdev_init_modern(void)
>> +{
>> +    while (!QSIMPLEQ_EMPTY(&nd_queue)) {
>> +        NetdevQueueEntry *nd = QSIMPLEQ_FIRST(&nd_queue);
>> +
>> +        QSIMPLEQ_REMOVE_HEAD(&nd_queue, entry);
>> +        loc_push_restore(&nd->loc);
>> +        net_client_init1(nd->nd, true, &error_fatal);
>> +        loc_pop(&nd->loc);
>> +        qapi_free_Netdev(nd->nd);
>> +        g_free(nd);
>> +    }
>> +}
>> +
>>   void net_init_clients(void)
>>   {
>>       net_change_state_entry =
>> @@ -1569,6 +1594,8 @@ void net_init_clients(void)
>>   
>>       QTAILQ_INIT(&net_clients);
>>   
>> +    netdev_init_modern();
>> +
>>       qemu_opts_foreach(qemu_find_opts("netdev"), net_init_netdev, NULL,
>>                         &error_fatal);
>>   
>> @@ -1579,6 +1606,39 @@ void net_init_clients(void)
>>                         &error_fatal);
>>   }
>>   
>> +/*
>> + * netdev_is_modern() returns true when the backend needs to bypass
>> + * qemu_opts_parse_noisily()
>> + */
>> +static bool netdev_is_modern(const char *optarg)
>> +{
>> +    return false;
>> +}
>> +
>> +/*
>> + * netdev_parse_modern() uses modern, more expressive syntax than
>> + * net_client_parse(), supports only the netdev option.
>> + */
>> +int netdev_parse_modern(const char *optarg)
>> +{
>> +    Visitor *v;
>> +    NetdevQueueEntry *nd;
>> +
>> +    if (!netdev_is_modern(optarg)) {
>> +        return -1;
>> +    }
>> +
>> +    v = qobject_input_visitor_new_str(optarg, "type", &error_fatal);
>> +    nd = g_new(NetdevQueueEntry, 1);
>> +    visit_type_Netdev(v, NULL, &nd->nd, &error_fatal);
>> +    visit_free(v);
>> +    loc_save(&nd->loc);
>> +
>> +    QSIMPLEQ_INSERT_TAIL(&nd_queue, nd, entry);
>> +
>> +    return 0;
>> +}
>> +
>>   int net_client_parse(QemuOptsList *opts_list, const char *optarg)
>>   {
>>       if (!qemu_opts_parse_noisily(opts_list, optarg, true)) {
>> diff --git a/softmmu/vl.c b/softmmu/vl.c
>> index 8eed0f31c073..838f5b48c447 100644
>> --- a/softmmu/vl.c
>> +++ b/softmmu/vl.c
>> @@ -2839,7 +2839,8 @@ void qemu_init(int argc, char **argv, char **envp)
>>                   break;
>>               case QEMU_OPTION_netdev:
>>                   default_net = 0;
>> -                if (net_client_parse(qemu_find_opts("netdev"), optarg) == -1) {
>> +                if (netdev_parse_modern(optarg) == -1 &&
>> +                    net_client_parse(qemu_find_opts("netdev"), optarg) == -1) {
>>                       exit(1);
>>                   }
>>                   break;
> 
> To make this work, netdev_parse_modern() must
> 
> * either succeeed, or
> 
> * fail without reporting an error, or
> 
> * report an error and exit()
> 
> Recommend to spell that out in its function comment.
> 
> Alternatively:
> 
>                     if (netdev_is_modern(optarg)) {
>                         netdev_parse_modern(optarg);
>                     } else {
>                         if (net_client_parse(qemu_find_opts("netdev"), optarg) == -1) {
>                             exit(1);
>                         }
>                     }
> 
> netdev_is_modern() needs external linkage, and netdev_parse_modern()
> loses its return value.
> 
> Note that all callers net_client_parse() handle failure exactly the same
> way.  If we let net_client_parse() exit(), then this becomes
> 
>                     if (netdev_is_modern(optarg)) {
>                         netdev_parse_modern(optarg);
>                     } else {
>                         net_client_parse(qemu_find_opts("netdev"), optarg);
>                     }
> 
> I like this one best.  What do you think?
> 

Me too.

I wanted to have only entry point in net.c it's why I didn't export netdev_is_modern() but 
I think it's better to export it not to mix error return (parse has failed) and checking 
result (is modern or not).

And I agree it's more consistent to have both parse functions behaving in the same way 
(exit or not exit...).

I update the patch in that way.

Thanks,
Laurent



^ permalink raw reply	[flat|nested] 28+ messages in thread

* Re: [RFC PATCH v3 04/11] qapi: net: add stream and dgram netdevs
  2022-06-20 10:18 ` [RFC PATCH v3 04/11] qapi: net: add stream and dgram netdevs Laurent Vivier
@ 2022-06-20 15:21   ` Markus Armbruster
  2022-06-20 17:52     ` Laurent Vivier
  0 siblings, 1 reply; 28+ messages in thread
From: Markus Armbruster @ 2022-06-20 15:21 UTC (permalink / raw)
  To: Laurent Vivier
  Cc: qemu-devel, Eric Blake, Dr. David Alan Gilbert, Paolo Bonzini,
	Daniel P. Berrangé,
	Jason Wang, Stefano Brivio

Laurent Vivier <lvivier@redhat.com> writes:

> Copied from socket netdev file and modified to use SocketAddress
> to be able to introduce new features like unix socket.
>
> "udp" and "mcast" are squashed into dgram netdev, multicast is detected
> according to the IP address type.
> "listen" and "connect" modes are managed by stream netdev. An optional
> parameter "server" defines the mode (server by default)
>
> Signed-off-by: Laurent Vivier <lvivier@redhat.com>
> Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
> ---
>  hmp-commands.hx |   2 +-
>  net/clients.h   |   6 +
>  net/dgram.c     | 630 ++++++++++++++++++++++++++++++++++++++++++++++++
>  net/hub.c       |   2 +
>  net/meson.build |   2 +
>  net/net.c       |  19 +-
>  net/stream.c    | 425 ++++++++++++++++++++++++++++++++
>  qapi/net.json   |  40 ++-
>  qemu-options.hx |  12 +
>  9 files changed, 1133 insertions(+), 5 deletions(-)
>  create mode 100644 net/dgram.c
>  create mode 100644 net/stream.c
>
> diff --git a/hmp-commands.hx b/hmp-commands.hx
> index 564f1de364df..2938d13725cc 100644
> --- a/hmp-commands.hx
> +++ b/hmp-commands.hx
> @@ -1269,7 +1269,7 @@ ERST
>      {
>          .name       = "netdev_add",
>          .args_type  = "netdev:O",
> -        .params     = "[user|tap|socket|vde|bridge|hubport|netmap|vhost-user"
> +        .params     = "[user|tap|socket|stream|dgram|vde|bridge|hubport|netmap|vhost-user"
>  #ifdef CONFIG_VMNET
>                        "|vmnet-host|vmnet-shared|vmnet-bridged"
>  #endif
> diff --git a/net/clients.h b/net/clients.h
> index c9157789f2ce..ed8bdfff1e7c 100644
> --- a/net/clients.h
> +++ b/net/clients.h
> @@ -40,6 +40,12 @@ int net_init_hubport(const Netdev *netdev, const char *name,
>  int net_init_socket(const Netdev *netdev, const char *name,
>                      NetClientState *peer, Error **errp);
>  
> +int net_init_stream(const Netdev *netdev, const char *name,
> +                    NetClientState *peer, Error **errp);
> +
> +int net_init_dgram(const Netdev *netdev, const char *name,
> +                   NetClientState *peer, Error **errp);
> +
>  int net_init_tap(const Netdev *netdev, const char *name,
>                   NetClientState *peer, Error **errp);
>  
> diff --git a/net/dgram.c b/net/dgram.c
> new file mode 100644
> index 000000000000..aa4240501ed0
> --- /dev/null
> +++ b/net/dgram.c
> @@ -0,0 +1,630 @@
> +/*
> + * QEMU System Emulator
> + *
> + * Copyright (c) 2003-2008 Fabrice Bellard
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a copy
> + * of this software and associated documentation files (the "Software"), to deal
> + * in the Software without restriction, including without limitation the rights
> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
> + * copies of the Software, and to permit persons to whom the Software is
> + * furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
> + * THE SOFTWARE.
> + */

Blank line here, please.

> +#include "qemu/osdep.h"
> +
> +#include "net/net.h"
> +#include "clients.h"
> +#include "monitor/monitor.h"
> +#include "qapi/error.h"
> +#include "qemu/error-report.h"
> +#include "qemu/option.h"
> +#include "qemu/sockets.h"
> +#include "qemu/iov.h"
> +#include "qemu/main-loop.h"
> +#include "qemu/cutils.h"
> +
> +typedef struct NetDgramState {
> +    NetClientState nc;
> +    int listen_fd;
> +    int fd;
> +    SocketReadState rs;
> +  /* contains inet host and port destination iff connectionless (SOCK_DGRAM) */
> +    struct sockaddr_in dgram_dst;
> +    IOHandler *send_fn;           /* differs between SOCK_STREAM/SOCK_DGRAM */
> +    bool read_poll;               /* waiting to receive data? */
> +    bool write_poll;              /* waiting to transmit data? */
> +} NetDgramState;
> +
> +static void net_dgram_accept(void *opaque);
> +static void net_dgram_writable(void *opaque);
> +
> +static void net_dgram_update_fd_handler(NetDgramState *s)
> +{
> +    qemu_set_fd_handler(s->fd,
> +                        s->read_poll ? s->send_fn : NULL,
> +                        s->write_poll ? net_dgram_writable : NULL,
> +                        s);
> +}
> +
> +static void net_dgram_read_poll(NetDgramState *s, bool enable)
> +{
> +    s->read_poll = enable;
> +    net_dgram_update_fd_handler(s);
> +}
> +
> +static void net_dgram_write_poll(NetDgramState *s, bool enable)
> +{
> +    s->write_poll = enable;
> +    net_dgram_update_fd_handler(s);
> +}
> +
> +static void net_dgram_writable(void *opaque)
> +{
> +    NetDgramState *s = opaque;
> +
> +    net_dgram_write_poll(s, false);
> +
> +    qemu_flush_queued_packets(&s->nc);
> +}
> +
> +static ssize_t net_dgram_receive_dgram(NetClientState *nc,
> +                                       const uint8_t *buf, size_t size)
> +{
> +    NetDgramState *s = DO_UPCAST(NetDgramState, nc, nc);
> +    ssize_t ret;
> +
> +    do {
> +        if (s->dgram_dst.sin_family != AF_UNIX) {
> +            ret = sendto(s->fd, buf, size, 0,
> +                         (struct sockaddr *)&s->dgram_dst,
> +                         sizeof(s->dgram_dst));
> +        } else {
> +            ret = send(s->fd, buf, size, 0);
> +        }
> +    } while (ret == -1 && errno == EINTR);
> +
> +    if (ret == -1 && errno == EAGAIN) {
> +        net_dgram_write_poll(s, true);
> +        return 0;
> +    }
> +    return ret;
> +}
> +
> +static void net_dgram_send_completed(NetClientState *nc, ssize_t len)
> +{
> +    NetDgramState *s = DO_UPCAST(NetDgramState, nc, nc);
> +
> +    if (!s->read_poll) {
> +        net_dgram_read_poll(s, true);
> +    }
> +}
> +
> +static void net_dgram_rs_finalize(SocketReadState *rs)
> +{
> +    NetDgramState *s = container_of(rs, NetDgramState, rs);
> +
> +    if (qemu_send_packet_async(&s->nc, rs->buf,
> +                               rs->packet_len,
> +                               net_dgram_send_completed) == 0) {
> +        net_dgram_read_poll(s, false);
> +    }
> +}
> +
> +static void net_dgram_send(void *opaque)
> +{
> +    NetDgramState *s = opaque;
> +    int size;
> +    int ret;
> +    uint8_t buf1[NET_BUFSIZE];
> +    const uint8_t *buf;
> +
> +    size = recv(s->fd, buf1, sizeof(buf1), 0);
> +    if (size < 0) {
> +        if (errno != EWOULDBLOCK) {
> +            goto eoc;
> +        }
> +    } else if (size == 0) {
> +        /* end of connection */
> +    eoc:
> +        net_dgram_read_poll(s, false);
> +        net_dgram_write_poll(s, false);
> +        if (s->listen_fd != -1) {
> +            qemu_set_fd_handler(s->listen_fd, net_dgram_accept, NULL, s);
> +        }
> +        closesocket(s->fd);
> +
> +        s->fd = -1;
> +        net_socket_rs_init(&s->rs, net_dgram_rs_finalize, false);
> +        s->nc.link_down = true;
> +        memset(s->nc.info_str, 0, sizeof(s->nc.info_str));
> +
> +        return;
> +    }
> +    buf = buf1;
> +
> +    ret = net_fill_rstate(&s->rs, buf, size);
> +
> +    if (ret == -1) {
> +        goto eoc;
> +    }
> +}
> +
> +static void net_dgram_send_dgram(void *opaque)
> +{
> +    NetDgramState *s = opaque;
> +    int size;
> +
> +    size = recv(s->fd, s->rs.buf, sizeof(s->rs.buf), 0);
> +    if (size < 0) {
> +        return;
> +    }
> +    if (size == 0) {
> +        /* end of connection */
> +        net_dgram_read_poll(s, false);
> +        net_dgram_write_poll(s, false);
> +        return;
> +    }
> +    if (qemu_send_packet_async(&s->nc, s->rs.buf, size,
> +                               net_dgram_send_completed) == 0) {
> +        net_dgram_read_poll(s, false);
> +    }
> +}
> +
> +static int net_dgram_mcast_create(struct sockaddr_in *mcastaddr,
> +                                  struct in_addr *localaddr,
> +                                  Error **errp)
> +{
> +    struct ip_mreq imr;
> +    int fd;
> +    int val, ret;
> +#ifdef __OpenBSD__
> +    unsigned char loop;
> +#else
> +    int loop;
> +#endif
> +
> +    if (!IN_MULTICAST(ntohl(mcastaddr->sin_addr.s_addr))) {
> +        error_setg(errp, "specified mcastaddr %s (0x%08x) "
> +                   "does not contain a multicast address",
> +                   inet_ntoa(mcastaddr->sin_addr),
> +                   (int)ntohl(mcastaddr->sin_addr.s_addr));
> +        return -1;
> +    }
> +
> +    fd = qemu_socket(PF_INET, SOCK_DGRAM, 0);
> +    if (fd < 0) {
> +        error_setg_errno(errp, errno, "can't create datagram socket");
> +        return -1;
> +    }
> +
> +    /*
> +     * Allow multiple sockets to bind the same multicast ip and port by setting
> +     * SO_REUSEADDR. This is the only situation where SO_REUSEADDR should be set
> +     * on windows. Use socket_set_fast_reuse otherwise as it sets SO_REUSEADDR
> +     * only on posix systems.
> +     */
> +    val = 1;
> +    ret = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
> +    if (ret < 0) {
> +        error_setg_errno(errp, errno, "can't set socket option SO_REUSEADDR");
> +        goto fail;
> +    }
> +
> +    ret = bind(fd, (struct sockaddr *)mcastaddr, sizeof(*mcastaddr));
> +    if (ret < 0) {
> +        error_setg_errno(errp, errno, "can't bind ip=%s to socket",
> +                         inet_ntoa(mcastaddr->sin_addr));
> +        goto fail;
> +    }
> +
> +    /* Add host to multicast group */
> +    imr.imr_multiaddr = mcastaddr->sin_addr;
> +    if (localaddr) {
> +        imr.imr_interface = *localaddr;
> +    } else {
> +        imr.imr_interface.s_addr = htonl(INADDR_ANY);
> +    }
> +
> +    ret = setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP,
> +                     &imr, sizeof(struct ip_mreq));
> +    if (ret < 0) {
> +        error_setg_errno(errp, errno,
> +                         "can't add socket to multicast group %s",
> +                         inet_ntoa(imr.imr_multiaddr));
> +        goto fail;
> +    }
> +
> +    /* Force mcast msgs to loopback (eg. several QEMUs in same host */
> +    loop = 1;
> +    ret = setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP,
> +                     &loop, sizeof(loop));
> +    if (ret < 0) {
> +        error_setg_errno(errp, errno,
> +                         "can't force multicast message to loopback");
> +        goto fail;
> +    }
> +
> +    /* If a bind address is given, only send packets from that address */
> +    if (localaddr != NULL) {
> +        ret = setsockopt(fd, IPPROTO_IP, IP_MULTICAST_IF,
> +                         localaddr, sizeof(*localaddr));
> +        if (ret < 0) {
> +            error_setg_errno(errp, errno,
> +                             "can't set the default network send interface");
> +            goto fail;
> +        }
> +    }
> +
> +    qemu_socket_set_nonblock(fd);
> +    return fd;
> +fail:
> +    if (fd >= 0) {
> +        closesocket(fd);
> +    }
> +    return -1;
> +}
> +
> +static void net_dgram_cleanup(NetClientState *nc)
> +{
> +    NetDgramState *s = DO_UPCAST(NetDgramState, nc, nc);
> +    if (s->fd != -1) {
> +        net_dgram_read_poll(s, false);
> +        net_dgram_write_poll(s, false);
> +        close(s->fd);
> +        s->fd = -1;
> +    }
> +    if (s->listen_fd != -1) {
> +        qemu_set_fd_handler(s->listen_fd, NULL, NULL, NULL);
> +        closesocket(s->listen_fd);
> +        s->listen_fd = -1;
> +    }
> +}
> +
> +static NetClientInfo net_dgram_socket_info = {
> +    .type = NET_CLIENT_DRIVER_DGRAM,
> +    .size = sizeof(NetDgramState),
> +    .receive = net_dgram_receive_dgram,
> +    .cleanup = net_dgram_cleanup,
> +};
> +
> +static NetDgramState *net_dgram_fd_init_dgram(NetClientState *peer,
> +                                              const char *model,
> +                                              const char *name,
> +                                              int fd, int is_fd,
> +                                              SocketAddress *mcast,
> +                                              Error **errp)
> +{
> +    struct sockaddr_in saddr;
> +    int newfd;
> +    NetClientState *nc;
> +    NetDgramState *s;
> +    SocketAddress *sa;
> +    SocketAddressType sa_type;
> +
> +    sa = socket_local_address(fd, errp);
> +    if (!sa) {
> +        return NULL;
> +    }
> +    sa_type = sa->type;
> +    qapi_free_SocketAddress(sa);
> +
> +    /*
> +     * fd passed: multicast: "learn" dgram_dst address from bound address and
> +     * save it. Because this may be "shared" socket from a "master" process,
> +     * datagrams would be recv() by ONLY ONE process: we must "clone" this
> +     * dgram socket --jjo
> +     */
> +
> +    if (is_fd && mcast != NULL) {
> +            if (convert_host_port(&saddr, mcast->u.inet.host,
> +                                  mcast->u.inet.port, errp) < 0) {
> +                goto err;
> +            }
> +            /* must be bound */
> +            if (saddr.sin_addr.s_addr == 0) {
> +                error_setg(errp, "can't setup multicast destination address");
> +                goto err;
> +            }
> +            /* clone dgram socket */
> +            newfd = net_dgram_mcast_create(&saddr, NULL, errp);
> +            if (newfd < 0) {
> +                goto err;
> +            }
> +            /* clone newfd to fd, close newfd */
> +            dup2(newfd, fd);
> +            close(newfd);
> +
> +    }
> +
> +    nc = qemu_new_net_client(&net_dgram_socket_info, peer, model, name);
> +
> +    s = DO_UPCAST(NetDgramState, nc, nc);
> +
> +    s->fd = fd;
> +    s->listen_fd = -1;
> +    s->send_fn = net_dgram_send_dgram;
> +    net_socket_rs_init(&s->rs, net_dgram_rs_finalize, false);
> +    net_dgram_read_poll(s, true);
> +
> +    /* mcast: save bound address as dst */
> +    if (is_fd && mcast != NULL) {
> +        s->dgram_dst = saddr;
> +        snprintf(nc->info_str, sizeof(nc->info_str),
> +                 "fd=%d (cloned mcast=%s:%d)",
> +                 fd, inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
> +    } else {
> +        if (sa_type == SOCKET_ADDRESS_TYPE_UNIX) {
> +            s->dgram_dst.sin_family = AF_UNIX;
> +        }
> +
> +        snprintf(nc->info_str, sizeof(nc->info_str), "fd=%d %s", fd,
> +                 SocketAddressType_str(sa_type));
> +    }
> +
> +    return s;
> +
> +err:
> +    closesocket(fd);
> +    return NULL;
> +}
> +
> +static void net_dgram_connect(void *opaque)
> +{
> +    NetDgramState *s = opaque;
> +    s->send_fn = net_dgram_send;
> +    net_dgram_read_poll(s, true);
> +}
> +
> +static void net_dgram_accept(void *opaque)
> +{
> +    NetDgramState *s = opaque;
> +    struct sockaddr_in saddr;
> +    socklen_t len;
> +    int fd;
> +
> +    for (;;) {
> +        len = sizeof(saddr);
> +        fd = qemu_accept(s->listen_fd, (struct sockaddr *)&saddr, &len);
> +        if (fd < 0 && errno != EINTR) {
> +            return;
> +        } else if (fd >= 0) {
> +            qemu_set_fd_handler(s->listen_fd, NULL, NULL, NULL);
> +            break;
> +        }
> +    }
> +
> +    s->fd = fd;
> +    s->nc.link_down = false;
> +    net_dgram_connect(s);
> +    snprintf(s->nc.info_str, sizeof(s->nc.info_str), "connection from %s:%d",
> +             inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
> +}
> +
> +static int net_dgram_mcast_init(NetClientState *peer,
> +                                const char *model,
> +                                const char *name,
> +                                SocketAddress *remote,
> +                                SocketAddress *local,
> +                                Error **errp)
> +{
> +    NetDgramState *s;
> +    int fd, ret;
> +    struct sockaddr_in saddr;
> +
> +    if (remote->type != SOCKET_ADDRESS_TYPE_INET) {
> +        error_setg(errp, "multicast only support inet type");
> +        return -1;
> +    }
> +
> +    if (convert_host_port(&saddr, remote->u.inet.host, remote->u.inet.port,
> +                          errp) < 0) {
> +        return -1;
> +    }
> +
> +    if (!local) {
> +        fd = net_dgram_mcast_create(&saddr, NULL, errp);
> +        if (fd < 0) {
> +            return -1;
> +        }
> +    } else {
> +        switch (local->type) {
> +        case SOCKET_ADDRESS_TYPE_INET: {
> +            struct in_addr localaddr;
> +
> +            if (inet_aton(local->u.inet.host, &localaddr) == 0) {
> +                error_setg(errp, "localaddr '%s' is not a valid IPv4 address",
> +                           local->u.inet.host);
> +                return -1;
> +            }
> +
> +            fd = net_dgram_mcast_create(&saddr, &localaddr, errp);
> +            if (fd < 0) {
> +                return -1;
> +            }
> +            break;
> +        }
> +        case SOCKET_ADDRESS_TYPE_FD:
> +            fd = monitor_fd_param(monitor_cur(), local->u.fd.str, errp);
> +            if (fd == -1) {
> +                return -1;
> +            }
> +            ret = qemu_socket_try_set_nonblock(fd);
> +            if (ret < 0) {
> +                error_setg_errno(errp, -ret, "%s: Can't use file descriptor %d",
> +                                 name, fd);
> +                return -1;
> +            }
> +            break;
> +        default:
> +            error_setg(errp, "only support inet or fd type for local");
> +            return -1;
> +        }
> +    }
> +
> +    s = net_dgram_fd_init_dgram(peer, model, name, fd,
> +                                 local->type == SOCKET_ADDRESS_TYPE_FD,
> +                                 remote, errp);
> +    if (!s) {
> +        return -1;
> +    }
> +
> +    s->dgram_dst = saddr;
> +
> +    snprintf(s->nc.info_str, sizeof(s->nc.info_str), "mcast=%s:%d",
> +             inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
> +    return 0;
> +
> +}
> +
> +static int net_dgram_udp_init(NetClientState *peer,
> +                              const char *model,
> +                              const char *name,
> +                              SocketAddress *remote,
> +                              SocketAddress *local,
> +                              Error **errp)
> +{
> +    NetDgramState *s;
> +    int fd, ret;
> +    struct sockaddr_in raddr_in;
> +    gchar *info_str;
> +
> +    if (remote) {
> +        if (local->type == SOCKET_ADDRESS_TYPE_FD) {
> +            error_setg(errp, "don't set remote with local.fd");
> +            return -1;
> +        }
> +        if (remote->type != local->type) {
> +            error_setg(errp, "remote and local types must be the same");
> +            return -1;
> +        }
> +    } else {
> +        if (local->type != SOCKET_ADDRESS_TYPE_FD) {
> +            error_setg(errp, "type=inet requires remote parameter");
> +            return -1;
> +        }
> +    }
> +
> +    switch (local->type) {
> +    case SOCKET_ADDRESS_TYPE_INET: {
> +        struct sockaddr_in laddr_in;
> +
> +        if (convert_host_port(&laddr_in, local->u.inet.host, local->u.inet.port,
> +                              errp) < 0) {
> +            return -1;
> +        }
> +
> +        if (convert_host_port(&raddr_in, remote->u.inet.host,
> +                              remote->u.inet.port, errp) < 0) {
> +            return -1;
> +        }
> +
> +        fd = qemu_socket(PF_INET, SOCK_DGRAM, 0);
> +        if (fd < 0) {
> +            error_setg_errno(errp, errno, "can't create datagram socket");
> +            return -1;
> +        }
> +
> +        ret = socket_set_fast_reuse(fd);
> +        if (ret < 0) {
> +            error_setg_errno(errp, errno,
> +                             "can't set socket option SO_REUSEADDR");
> +            closesocket(fd);
> +            return -1;
> +        }
> +        ret = bind(fd, (struct sockaddr *)&laddr_in, sizeof(laddr_in));
> +        if (ret < 0) {
> +            error_setg_errno(errp, errno, "can't bind ip=%s to socket",
> +                             inet_ntoa(laddr_in.sin_addr));
> +            closesocket(fd);
> +            return -1;
> +        }
> +        qemu_socket_set_nonblock(fd);
> +
> +        info_str = g_strdup_printf("udp=%s:%d/%s:%d",
> +                 inet_ntoa(laddr_in.sin_addr), ntohs(laddr_in.sin_port),
> +                 inet_ntoa(raddr_in.sin_addr), ntohs(raddr_in.sin_port));
> +
> +        break;
> +    }
> +    case SOCKET_ADDRESS_TYPE_FD:
> +        fd = monitor_fd_param(monitor_cur(), local->u.fd.str, errp);
> +        if (fd == -1) {
> +            return -1;
> +        }
> +        ret = qemu_socket_try_set_nonblock(fd);
> +        if (ret < 0) {
> +            error_setg_errno(errp, -ret, "%s: Can't use file descriptor %d",
> +                             name, fd);
> +            return -1;
> +        }
> +        break;
> +    default:
> +        error_setg(errp, "only support inet or fd type for local");
> +        return -1;
> +    }
> +
> +    s = net_dgram_fd_init_dgram(peer, model, name, fd, 0, NULL, errp);
> +    if (!s) {
> +        return -1;
> +    }
> +
> +    if (remote) {
> +        s->dgram_dst = raddr_in;
> +
> +        pstrcpy(s->nc.info_str, sizeof(s->nc.info_str), info_str);
> +        g_free(info_str);
> +    }
> +    return 0;
> +}
> +
> +static int net_dgram_init(NetClientState *peer,
> +                          const char *model,
> +                          const char *name,
> +                          SocketAddress *remote,
> +                          SocketAddress *local,
> +                          Error **errp)
> +{
> +    /* detect multicast address */
> +    if (remote && remote->type == SOCKET_ADDRESS_TYPE_INET) {
> +        struct sockaddr_in mcastaddr;
> +
> +        if (convert_host_port(&mcastaddr, remote->u.inet.host,
> +                              remote->u.inet.port, errp) < 0) {
> +            return -1;
> +        }
> +
> +        if (IN_MULTICAST(ntohl(mcastaddr.sin_addr.s_addr))) {
> +            return net_dgram_mcast_init(peer, model, name, remote, local,
> +                                           errp);
> +        }
> +    }
> +    /* unicast address */
> +    if (!local) {
> +        error_setg(errp, "dgram requires local= parameter");
> +        return -1;
> +    }
> +    return net_dgram_udp_init(peer, model, name, remote, local, errp);
> +}
> +
> +int net_init_dgram(const Netdev *netdev, const char *name,
> +                   NetClientState *peer, Error **errp)
> +{
> +    const NetdevDgramOptions *sock;
> +
> +    assert(netdev->type == NET_CLIENT_DRIVER_DGRAM);
> +    sock = &netdev->u.dgram;
> +
> +    return net_dgram_init(peer, "dgram", name, sock->remote, sock->local,
> +                          errp);
> +}
> diff --git a/net/hub.c b/net/hub.c
> index 1375738bf121..67ca53485638 100644
> --- a/net/hub.c
> +++ b/net/hub.c
> @@ -313,6 +313,8 @@ void net_hub_check_clients(void)
>              case NET_CLIENT_DRIVER_USER:
>              case NET_CLIENT_DRIVER_TAP:
>              case NET_CLIENT_DRIVER_SOCKET:
> +            case NET_CLIENT_DRIVER_STREAM:
> +            case NET_CLIENT_DRIVER_DGRAM:
>              case NET_CLIENT_DRIVER_VDE:
>              case NET_CLIENT_DRIVER_VHOST_USER:
>                  has_host_dev = 1;
> diff --git a/net/meson.build b/net/meson.build
> index 754e2d1d405c..896d86d43914 100644
> --- a/net/meson.build
> +++ b/net/meson.build
> @@ -13,6 +13,8 @@ softmmu_ss.add(files(
>    'net.c',
>    'queue.c',
>    'socket.c',
> +  'stream.c',
> +  'dgram.c',
>    'util.c',
>  ))
>  
> diff --git a/net/net.c b/net/net.c
> index c337d3d753fe..440957b272ee 100644
> --- a/net/net.c
> +++ b/net/net.c
> @@ -48,6 +48,7 @@
>  #include "qemu/qemu-print.h"
>  #include "qemu/main-loop.h"
>  #include "qemu/option.h"
> +#include "qemu/keyval.h"
>  #include "qapi/error.h"
>  #include "qapi/opts-visitor.h"
>  #include "sysemu/runstate.h"
> @@ -1014,6 +1015,8 @@ static int (* const net_client_init_fun[NET_CLIENT_DRIVER__MAX])(
>  #endif
>          [NET_CLIENT_DRIVER_TAP]       = net_init_tap,
>          [NET_CLIENT_DRIVER_SOCKET]    = net_init_socket,
> +        [NET_CLIENT_DRIVER_STREAM]    = net_init_stream,
> +        [NET_CLIENT_DRIVER_DGRAM]     = net_init_dgram,
>  #ifdef CONFIG_VDE
>          [NET_CLIENT_DRIVER_VDE]       = net_init_vde,
>  #endif
> @@ -1101,6 +1104,8 @@ void show_netdevs(void)
>      int idx;
>      const char *available_netdevs[] = {
>          "socket",
> +        "stream",
> +        "dgram",
>          "hubport",
>          "tap",
>  #ifdef CONFIG_SLIRP
> @@ -1612,7 +1617,19 @@ void net_init_clients(void)
>   */
>  static bool netdev_is_modern(const char *optarg)
>  {
> -    return false;
> +    QDict *args;
> +    const char *type;
> +    bool is_modern;
> +
> +    args = keyval_parse(optarg, "type", NULL, NULL);
> +    if (!args) {
> +        return false;
> +    }
> +    type = qdict_get_try_str(args, "type");
> +    is_modern = !g_strcmp0(type, "stream") || !g_strcmp0(type, "dgram");
> +    qobject_unref(args);
> +
> +    return is_modern;
>  }

You could use g_autoptr here:

       g_autoptr(QDict) args = NULL;
       const char *type;
       bool is_modern;

       args = keyval_parse(optarg, "type", NULL, NULL);
       if (!args) {
           return false;
       }
       type = qdict_get_try_str(args, "type");
       return !g_strcmp0(type, "stream") || !g_strcmp0(type, "dgram");

Matter of taste; you decide.

Now recall how this function is used: it decides whether to parse the
modern way (with qobject_input_visitor_new_str()) or the traditional way
(with qemu_opts_parse_noisily()).

qemu_opts_parse_noisily() parses into a QemuOpts, for later use with the
opts visitor.

qobject_input_visitor_new_str() supports both dotted keys and JSON.  The
former is parsed with keyval_parse(), the latter with
qobject_from_json().  It returns the resulting parse tree wrapped in a
suitable QAPI input visitor.

Issue 1: since we get there only when keyval_parse() succeeds, JSON is
unreachable.  Reproducer:

    $ qemu-system-x86_64 -netdev '{"id":"foo"}'
    upstream-qemu: -netdev {"id":"foo"}: Parameter 'id' is missing

This is parsed with qemu_opts_parse_noisily(), resulting in a QemuOpts
with a single option 'type' with value '{"id":"foo"}'.  The error
message comes from the opts visitor.

To fix this, make netdev_is_modern() return true when optarg[0] == '{'.
This matches how qobject_input_visitor_new_str() recognizes JSON.

Issue 2: when keyval_parse() detects an error, we throw it away and fall
back to QemuOpts.  This is commonly what we want.  But not always.  For
instance:

    $ qemu-system-x86_64 -netdev 'type=stream,id=foo,addr.type=inet,addr.host=localhost,addr.port=1234,addr.ipv4-off'

Note the typo "ipv4-off" instead of ipv4=off.  The error reporting is crap:

    qemu-system-x86_64: -netdev type=stream,id=foo,addr.type=inet,addr.host=localhost,addr.port=1234,addr.ipv4-off: warning: short-form boolean option 'addr.ipv4-off' deprecated
    Please use addr.ipv4-off=on instead
    qemu-system-x86_64: -netdev type=stream,id=foo,addr.type=inet,addr.host=localhost,addr.port=1234,addr.ipv4-off: Parameter 'type' is missing

We get this because netdev_is_modern() guesses wrongly: keyval_parse()
fails with the perfectly reasonable error message "Expected '=' after
parameter 'addr.ipv4-off'", but netdev_is_modern() ignores the error,
and fails.  We fall back to QemuOpts, and confusion ensues.

I'm not sure we can do much better with reasonable effort.  If we decide
to accept this behavior, it should be documented at least in the source
code.

>  
>  /*
> diff --git a/net/stream.c b/net/stream.c
> new file mode 100644
> index 000000000000..fdc97ee43a56
> --- /dev/null
> +++ b/net/stream.c
> @@ -0,0 +1,425 @@
> +/*
> + * QEMU System Emulator
> + *
> + * Copyright (c) 2003-2008 Fabrice Bellard
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a copy
> + * of this software and associated documentation files (the "Software"), to deal
> + * in the Software without restriction, including without limitation the rights
> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
> + * copies of the Software, and to permit persons to whom the Software is
> + * furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
> + * THE SOFTWARE.
> + */

Blank line here, please.

> +#include "qemu/osdep.h"
> +
> +#include "net/net.h"
> +#include "clients.h"
> +#include "monitor/monitor.h"
> +#include "qapi/error.h"
> +#include "qemu/error-report.h"
> +#include "qemu/option.h"
> +#include "qemu/sockets.h"
> +#include "qemu/iov.h"
> +#include "qemu/main-loop.h"
> +#include "qemu/cutils.h"
> +
> +typedef struct NetStreamState {
> +    NetClientState nc;
> +    int listen_fd;
> +    int fd;
> +    SocketReadState rs;
> +    unsigned int send_index;      /* number of bytes sent*/
> +    IOHandler *send_fn;
> +    bool read_poll;               /* waiting to receive data? */
> +    bool write_poll;              /* waiting to transmit data? */
> +} NetStreamState;
> +
> +static void net_stream_accept(void *opaque);
> +static void net_stream_writable(void *opaque);
> +
> +static void net_stream_update_fd_handler(NetStreamState *s)
> +{
> +    qemu_set_fd_handler(s->fd,
> +                        s->read_poll ? s->send_fn : NULL,
> +                        s->write_poll ? net_stream_writable : NULL,
> +                        s);
> +}
> +
> +static void net_stream_read_poll(NetStreamState *s, bool enable)
> +{
> +    s->read_poll = enable;
> +    net_stream_update_fd_handler(s);
> +}
> +
> +static void net_stream_write_poll(NetStreamState *s, bool enable)
> +{
> +    s->write_poll = enable;
> +    net_stream_update_fd_handler(s);
> +}
> +
> +static void net_stream_writable(void *opaque)
> +{
> +    NetStreamState *s = opaque;
> +
> +    net_stream_write_poll(s, false);
> +
> +    qemu_flush_queued_packets(&s->nc);
> +}
> +
> +static ssize_t net_stream_receive(NetClientState *nc, const uint8_t *buf,
> +                                  size_t size)
> +{
> +    NetStreamState *s = DO_UPCAST(NetStreamState, nc, nc);
> +    uint32_t len = htonl(size);
> +    struct iovec iov[] = {
> +        {
> +            .iov_base = &len,
> +            .iov_len  = sizeof(len),
> +        }, {
> +            .iov_base = (void *)buf,
> +            .iov_len  = size,
> +        },
> +    };
> +    size_t remaining;
> +    ssize_t ret;
> +
> +    remaining = iov_size(iov, 2) - s->send_index;
> +    ret = iov_send(s->fd, iov, 2, s->send_index, remaining);
> +
> +    if (ret == -1 && errno == EAGAIN) {
> +        ret = 0; /* handled further down */
> +    }
> +    if (ret == -1) {
> +        s->send_index = 0;
> +        return -errno;
> +    }
> +    if (ret < (ssize_t)remaining) {
> +        s->send_index += ret;
> +        net_stream_write_poll(s, true);
> +        return 0;
> +    }
> +    s->send_index = 0;
> +    return size;
> +}
> +
> +static void net_stream_send_completed(NetClientState *nc, ssize_t len)
> +{
> +    NetStreamState *s = DO_UPCAST(NetStreamState, nc, nc);
> +
> +    if (!s->read_poll) {
> +        net_stream_read_poll(s, true);
> +    }
> +}
> +
> +static void net_stream_rs_finalize(SocketReadState *rs)
> +{
> +    NetStreamState *s = container_of(rs, NetStreamState, rs);
> +
> +    if (qemu_send_packet_async(&s->nc, rs->buf,
> +                               rs->packet_len,
> +                               net_stream_send_completed) == 0) {
> +        net_stream_read_poll(s, false);
> +    }
> +}
> +
> +static void net_stream_send(void *opaque)
> +{
> +    NetStreamState *s = opaque;
> +    int size;
> +    int ret;
> +    uint8_t buf1[NET_BUFSIZE];
> +    const uint8_t *buf;
> +
> +    size = recv(s->fd, buf1, sizeof(buf1), 0);
> +    if (size < 0) {
> +        if (errno != EWOULDBLOCK) {
> +            goto eoc;
> +        }
> +    } else if (size == 0) {
> +        /* end of connection */
> +    eoc:
> +        net_stream_read_poll(s, false);
> +        net_stream_write_poll(s, false);
> +        if (s->listen_fd != -1) {
> +            qemu_set_fd_handler(s->listen_fd, net_stream_accept, NULL, s);
> +        }
> +        closesocket(s->fd);
> +
> +        s->fd = -1;
> +        net_socket_rs_init(&s->rs, net_stream_rs_finalize, false);
> +        s->nc.link_down = true;
> +        memset(s->nc.info_str, 0, sizeof(s->nc.info_str));
> +
> +        return;
> +    }
> +    buf = buf1;
> +
> +    ret = net_fill_rstate(&s->rs, buf, size);
> +
> +    if (ret == -1) {
> +        goto eoc;
> +    }
> +}
> +
> +static void net_stream_cleanup(NetClientState *nc)
> +{
> +    NetStreamState *s = DO_UPCAST(NetStreamState, nc, nc);
> +    if (s->fd != -1) {
> +        net_stream_read_poll(s, false);
> +        net_stream_write_poll(s, false);
> +        close(s->fd);
> +        s->fd = -1;
> +    }
> +    if (s->listen_fd != -1) {
> +        qemu_set_fd_handler(s->listen_fd, NULL, NULL, NULL);
> +        closesocket(s->listen_fd);
> +        s->listen_fd = -1;
> +    }
> +}
> +
> +static void net_stream_connect(void *opaque)
> +{
> +    NetStreamState *s = opaque;
> +    s->send_fn = net_stream_send;
> +    net_stream_read_poll(s, true);
> +}
> +
> +static NetClientInfo net_stream_info = {
> +    .type = NET_CLIENT_DRIVER_STREAM,
> +    .size = sizeof(NetStreamState),
> +    .receive = net_stream_receive,
> +    .cleanup = net_stream_cleanup,
> +};
> +
> +static NetStreamState *net_stream_fd_init_stream(NetClientState *peer,
> +                                                 const char *model,
> +                                                 const char *name,
> +                                                 int fd, int is_connected)
> +{
> +    NetClientState *nc;
> +    NetStreamState *s;
> +
> +    nc = qemu_new_net_client(&net_stream_info, peer, model, name);
> +
> +    snprintf(nc->info_str, sizeof(nc->info_str), "fd=%d", fd);
> +
> +    s = DO_UPCAST(NetStreamState, nc, nc);
> +
> +    s->fd = fd;
> +    s->listen_fd = -1;
> +    net_socket_rs_init(&s->rs, net_stream_rs_finalize, false);
> +
> +    /* Disable Nagle algorithm on TCP sockets to reduce latency */
> +    socket_set_nodelay(fd);
> +
> +    if (is_connected) {
> +        net_stream_connect(s);
> +    } else {
> +        qemu_set_fd_handler(s->fd, NULL, net_stream_connect, s);
> +    }
> +    return s;
> +}
> +
> +static void net_stream_accept(void *opaque)
> +{
> +    NetStreamState *s = opaque;
> +    struct sockaddr_in saddr;
> +    socklen_t len;
> +    int fd;
> +
> +    for (;;) {
> +        len = sizeof(saddr);
> +        fd = qemu_accept(s->listen_fd, (struct sockaddr *)&saddr, &len);
> +        if (fd < 0 && errno != EINTR) {
> +            return;
> +        } else if (fd >= 0) {
> +            qemu_set_fd_handler(s->listen_fd, NULL, NULL, NULL);
> +            break;
> +        }
> +    }
> +
> +    s->fd = fd;
> +    s->nc.link_down = false;
> +    net_stream_connect(s);
> +    snprintf(s->nc.info_str, sizeof(s->nc.info_str),
> +             "connection from %s:%d",
> +             inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
> +}
> +
> +static int net_stream_server_init(NetClientState *peer,
> +                                  const char *model,
> +                                  const char *name,
> +                                  SocketAddress *addr,
> +                                  Error **errp)
> +{
> +    NetClientState *nc;
> +    NetStreamState *s;
> +    int fd, ret;
> +
> +    switch (addr->type) {
> +    case SOCKET_ADDRESS_TYPE_INET: {
> +        struct sockaddr_in saddr_in;
> +
> +        if (convert_host_port(&saddr_in, addr->u.inet.host, addr->u.inet.port,
> +                              errp) < 0) {
> +            return -1;
> +        }
> +
> +        fd = qemu_socket(PF_INET, SOCK_STREAM, 0);
> +        if (fd < 0) {
> +            error_setg_errno(errp, errno, "can't create stream socket");
> +            return -1;
> +        }
> +        qemu_socket_set_nonblock(fd);
> +
> +        socket_set_fast_reuse(fd);
> +
> +        ret = bind(fd, (struct sockaddr *)&saddr_in, sizeof(saddr_in));
> +        if (ret < 0) {
> +            error_setg_errno(errp, errno, "can't bind ip=%s to socket",
> +                             inet_ntoa(saddr_in.sin_addr));
> +            closesocket(fd);
> +            return -1;
> +        }
> +        break;
> +    }
> +    case SOCKET_ADDRESS_TYPE_UNIX: {
> +        error_setg(errp, "only support inet type");
> +        return -1;
> +    }
> +    case SOCKET_ADDRESS_TYPE_FD:
> +        fd = monitor_fd_param(monitor_cur(), addr->u.fd.str, errp);
> +        if (fd == -1) {
> +            return -1;
> +        }
> +        ret = qemu_socket_try_set_nonblock(fd);
> +        if (ret < 0) {
> +            error_setg_errno(errp, -ret, "%s: Can't use file descriptor %d",
> +                             name, fd);
> +            return -1;
> +        }
> +        break;
> +    default:
> +        g_assert_not_reached();
> +    }
> +
> +    ret = listen(fd, 0);
> +    if (ret < 0) {
> +        error_setg_errno(errp, errno, "can't listen on socket");
> +        closesocket(fd);
> +        return -1;
> +    }
> +
> +    nc = qemu_new_net_client(&net_stream_info, peer, model, name);
> +    s = DO_UPCAST(NetStreamState, nc, nc);
> +    s->fd = -1;
> +    s->listen_fd = fd;
> +    s->nc.link_down = true;
> +    net_socket_rs_init(&s->rs, net_stream_rs_finalize, false);
> +
> +    qemu_set_fd_handler(s->listen_fd, net_stream_accept, NULL, s);
> +    return 0;
> +}
> +
> +static int net_stream_client_init(NetClientState *peer,
> +                                  const char *model,
> +                                  const char *name,
> +                                  SocketAddress *addr,
> +                                  Error **errp)
> +{
> +    NetStreamState *s;
> +    int fd, connected, ret;
> +    gchar *info_str;
> +
> +    switch (addr->type) {
> +    case SOCKET_ADDRESS_TYPE_INET: {
> +        struct sockaddr_in saddr_in;
> +
> +        if (convert_host_port(&saddr_in, addr->u.inet.host, addr->u.inet.port,
> +                              errp) < 0) {
> +            return -1;
> +        }
> +
> +        fd = qemu_socket(PF_INET, SOCK_STREAM, 0);
> +        if (fd < 0) {
> +            error_setg_errno(errp, errno, "can't create stream socket");
> +            return -1;
> +        }
> +        qemu_socket_set_nonblock(fd);
> +
> +        connected = 0;
> +        for (;;) {
> +            ret = connect(fd, (struct sockaddr *)&saddr_in, sizeof(saddr_in));
> +            if (ret < 0) {
> +                if (errno == EINTR || errno == EWOULDBLOCK) {
> +                    /* continue */
> +                } else if (errno == EINPROGRESS ||
> +                           errno == EALREADY ||
> +                           errno == EINVAL) {
> +                    break;
> +                } else {
> +                    error_setg_errno(errp, errno, "can't connect socket");
> +                    closesocket(fd);
> +                    return -1;
> +                }
> +            } else {
> +                connected = 1;
> +                break;
> +            }
> +        }
> +        info_str = g_strdup_printf("connect to %s:%d",
> +                                   inet_ntoa(saddr_in.sin_addr),
> +                                   ntohs(saddr_in.sin_port));
> +        break;
> +    }
> +    case SOCKET_ADDRESS_TYPE_FD:
> +        fd = monitor_fd_param(monitor_cur(), addr->u.fd.str, errp);
> +        if (fd == -1) {
> +            return -1;
> +        }
> +        ret = qemu_socket_try_set_nonblock(fd);
> +        if (ret < 0) {
> +            error_setg_errno(errp, -ret, "%s: Can't use file descriptor %d",
> +                             name, fd);
> +            return -1;
> +        }
> +        connected = 1;
> +        info_str = g_strdup_printf("connect to fd %d", fd);
> +        break;
> +    default:
> +        error_setg(errp, "only support inet or fd type");
> +        return -1;
> +    }
> +
> +    s = net_stream_fd_init_stream(peer, model, name, fd, connected);
> +
> +    pstrcpy(s->nc.info_str, sizeof(s->nc.info_str), info_str);
> +    g_free(info_str);
> +
> +    return 0;
> +}
> +
> +int net_init_stream(const Netdev *netdev, const char *name,
> +                    NetClientState *peer, Error **errp)
> +{
> +    const NetdevStreamOptions *sock;
> +
> +    assert(netdev->type == NET_CLIENT_DRIVER_STREAM);
> +    sock = &netdev->u.stream;
> +
> +    if (!sock->has_server || sock->server) {
> +        return net_stream_server_init(peer, "stream", name, sock->addr, errp);
> +    }
> +    return net_stream_client_init(peer, "stream", name, sock->addr, errp);
> +}
> diff --git a/qapi/net.json b/qapi/net.json
> index d6f7cfd4d656..5f72995b1d24 100644
> --- a/qapi/net.json
> +++ b/qapi/net.json
> @@ -7,6 +7,7 @@
>  ##
>  
>  { 'include': 'common.json' }
> +{ 'include': 'sockets.json' }
>  
>  ##
>  # @set_link:
> @@ -566,6 +567,37 @@
>      '*isolated':  'bool' },
>    'if': 'CONFIG_VMNET' }
>  
> +##
> +# @NetdevStreamOptions:
> +#
> +# Configuration info for stream socket netdev
> +#
> +# @addr: socket address to listen on (server=true)
> +#        or connect to (server=false)
> +# @server: create server socket (default: true)
> +#
> +# Since: 7.1
> +##
> +{ 'struct': 'NetdevStreamOptions',
> +  'data': {
> +    'addr':   'SocketAddress',
> +    '*server': 'bool' } }
> +
> +##
> +# @NetdevDgramOptions:
> +#
> +# Configuration info for datagram socket netdev.
> +#
> +# @remote: remote address
> +# @local: local address
> +#
> +# Since: 7.1
> +##
> +{ 'struct': 'NetdevDgramOptions',
> +  'data': {
> +    '*local':  'SocketAddress',
> +    '*remote': 'SocketAddress' } }

In review of v2, I inquired about behavior when members are absent.
You wrote:

    The code checks there is at least one of these options and reports an error if not.

    if remote address is present and it's a multicast address, local address is optional.

    otherwise local address is required and remote address is optional.

Please work that into the doc comment.

> +
>  ##
>  # @NetClientDriver:
>  #
> @@ -579,9 +611,9 @@
>  #        @vmnet-bridged since 7.1
>  ##
>  { 'enum': 'NetClientDriver',
> -  'data': [ 'none', 'nic', 'user', 'tap', 'l2tpv3', 'socket', 'vde',
> -            'bridge', 'hubport', 'netmap', 'vhost-user', 'vhost-vdpa',
> -            { 'name': 'vmnet-host', 'if': 'CONFIG_VMNET' },
> +  'data': [ 'none', 'nic', 'user', 'tap', 'l2tpv3', 'socket', 'stream',
> +            'dgram', 'vde', 'bridge', 'hubport', 'netmap', 'vhost-user',
> +            'vhost-vdpa', { 'name': 'vmnet-host', 'if': 'CONFIG_VMNET' },
>              { 'name': 'vmnet-shared', 'if': 'CONFIG_VMNET' },
>              { 'name': 'vmnet-bridged', 'if': 'CONFIG_VMNET' }] }

Opportunity to put vmnet-host on its own line for readability.

>  
> @@ -610,6 +642,8 @@
>      'tap':      'NetdevTapOptions',
>      'l2tpv3':   'NetdevL2TPv3Options',
>      'socket':   'NetdevSocketOptions',
> +    'stream':   'NetdevStreamOptions',
> +    'dgram':    'NetdevDgramOptions',
>      'vde':      'NetdevVdeOptions',
>      'bridge':   'NetdevBridgeOptions',
>      'hubport':  'NetdevHubPortOptions',
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 60cf188da429..c87dcdc65ece 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -2727,6 +2727,18 @@ DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
>      "-netdev socket,id=str[,fd=h][,udp=host:port][,localaddr=host:port]\n"
>      "                configure a network backend to connect to another network\n"
>      "                using an UDP tunnel\n"
> +    "-netdev stream,id=str[,server=on|off],addr.type=inet,addr.host=host,addr.port=port\n"
> +    "-netdev stream,id=str[,server=on|off],addr.type=fd,addr.str=h\n"
> +    "                configure a network backend to connect to another network\n"
> +    "                using a socket connection in stream mode.\n"
> +    "-netdev dgram,id=str,remote.type=inet,remote.host=maddr,remote.port=port[,local.type=inet,local.host=addr]\n"
> +    "-netdev dgram,id=str,remote.type=inet,remote.host=maddr,remote.port=port[,local.type=fd,local.str=h]\n"
> +    "                configure a network backend to connect to a multicast maddr and port\n"
> +    "                use 'local.host=addr' to specify the host address to send packets from\n"
> +    "-netdev dgram,id=str,local.type=inet,local.host=host,local.port=port[,remote.type=inet,remote.host=host,remote.port=port]\n"
> +    "-netdev dgram,id=str,local.type=fd,local.str=h\n"
> +    "                configure a network backend to connect to another network\n"
> +    "                using an UDP tunnel\n"
>  #ifdef CONFIG_VDE
>      "-netdev vde,id=str[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
>      "                configure a network backend to connect to port 'n' of a vde switch\n"



^ permalink raw reply	[flat|nested] 28+ messages in thread

* Re: [RFC PATCH v3 04/11] qapi: net: add stream and dgram netdevs
  2022-06-20 15:21   ` Markus Armbruster
@ 2022-06-20 17:52     ` Laurent Vivier
  2022-06-21  8:49       ` Markus Armbruster
  0 siblings, 1 reply; 28+ messages in thread
From: Laurent Vivier @ 2022-06-20 17:52 UTC (permalink / raw)
  To: Markus Armbruster
  Cc: qemu-devel, Eric Blake, Dr. David Alan Gilbert, Paolo Bonzini,
	Daniel P. Berrangé,
	Jason Wang, Stefano Brivio

On 20/06/2022 17:21, Markus Armbruster wrote:
> Laurent Vivier <lvivier@redhat.com> writes:
> 
>> Copied from socket netdev file and modified to use SocketAddress
>> to be able to introduce new features like unix socket.
>>
>> "udp" and "mcast" are squashed into dgram netdev, multicast is detected
>> according to the IP address type.
>> "listen" and "connect" modes are managed by stream netdev. An optional
>> parameter "server" defines the mode (server by default)
>>
>> Signed-off-by: Laurent Vivier <lvivier@redhat.com>
>> Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
>> ---
>>   hmp-commands.hx |   2 +-
>>   net/clients.h   |   6 +
>>   net/dgram.c     | 630 ++++++++++++++++++++++++++++++++++++++++++++++++
>>   net/hub.c       |   2 +
>>   net/meson.build |   2 +
>>   net/net.c       |  19 +-
>>   net/stream.c    | 425 ++++++++++++++++++++++++++++++++
>>   qapi/net.json   |  40 ++-
>>   qemu-options.hx |  12 +
>>   9 files changed, 1133 insertions(+), 5 deletions(-)
>>   create mode 100644 net/dgram.c
>>   create mode 100644 net/stream.c
>>
...
>> diff --git a/net/dgram.c b/net/dgram.c
>> new file mode 100644
>> index 000000000000..aa4240501ed0
>> --- /dev/null
>> +++ b/net/dgram.c
>> @@ -0,0 +1,630 @@
>> +/*
>> + * QEMU System Emulator
>> + *
>> + * Copyright (c) 2003-2008 Fabrice Bellard
>> + *
>> + * Permission is hereby granted, free of charge, to any person obtaining a copy
>> + * of this software and associated documentation files (the "Software"), to deal
>> + * in the Software without restriction, including without limitation the rights
>> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
>> + * copies of the Software, and to permit persons to whom the Software is
>> + * furnished to do so, subject to the following conditions:
>> + *
>> + * The above copyright notice and this permission notice shall be included in
>> + * all copies or substantial portions of the Software.
>> + *
>> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
>> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
>> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
>> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
>> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
>> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
>> + * THE SOFTWARE.
>> + */
> 
> Blank line here, please.

Done

...

>> diff --git a/net/net.c b/net/net.c
>> index c337d3d753fe..440957b272ee 100644
>> --- a/net/net.c
>> +++ b/net/net.c
...
>> @@ -1612,7 +1617,19 @@ void net_init_clients(void)
>>    */
>>   static bool netdev_is_modern(const char *optarg)
>>   {
>> -    return false;
>> +    QDict *args;
>> +    const char *type;
>> +    bool is_modern;
>> +
>> +    args = keyval_parse(optarg, "type", NULL, NULL);
>> +    if (!args) {
>> +        return false;
>> +    }
>> +    type = qdict_get_try_str(args, "type");
>> +    is_modern = !g_strcmp0(type, "stream") || !g_strcmp0(type, "dgram");
>> +    qobject_unref(args);
>> +
>> +    return is_modern;
>>   }
> 
> You could use g_autoptr here:
> 
>         g_autoptr(QDict) args = NULL;
>         const char *type;
>         bool is_modern;
> 
>         args = keyval_parse(optarg, "type", NULL, NULL);
>         if (!args) {
>             return false;
>         }
>         type = qdict_get_try_str(args, "type");
>         return !g_strcmp0(type, "stream") || !g_strcmp0(type, "dgram");
> 
> Matter of taste; you decide.

Looks good. We already had some series to convert existing code to g_autoptr(), so it 
seems the way to do.

> 
> Now recall how this function is used: it decides whether to parse the
> modern way (with qobject_input_visitor_new_str()) or the traditional way
> (with qemu_opts_parse_noisily()).
> 
> qemu_opts_parse_noisily() parses into a QemuOpts, for later use with the
> opts visitor.
> 
> qobject_input_visitor_new_str() supports both dotted keys and JSON.  The
> former is parsed with keyval_parse(), the latter with
> qobject_from_json().  It returns the resulting parse tree wrapped in a
> suitable QAPI input visitor.
> 
> Issue 1: since we get there only when keyval_parse() succeeds, JSON is
> unreachable.  Reproducer:
> 
>      $ qemu-system-x86_64 -netdev '{"id":"foo"}'
>      upstream-qemu: -netdev {"id":"foo"}: Parameter 'id' is missing
> 
> This is parsed with qemu_opts_parse_noisily(), resulting in a QemuOpts
> with a single option 'type' with value '{"id":"foo"}'.  The error
> message comes from the opts visitor.
> 
> To fix this, make netdev_is_modern() return true when optarg[0] == '{'.
> This matches how qobject_input_visitor_new_str() recognizes JSON.

OK

> 
> Issue 2: when keyval_parse() detects an error, we throw it away and fall
> back to QemuOpts.  This is commonly what we want.  But not always.  For
> instance:
> 
>      $ qemu-system-x86_64 -netdev 'type=stream,id=foo,addr.type=inet,addr.host=localhost,addr.port=1234,addr.ipv4-off'
> 
> Note the typo "ipv4-off" instead of ipv4=off.  The error reporting is crap:
> 
>      qemu-system-x86_64: -netdev type=stream,id=foo,addr.type=inet,addr.host=localhost,addr.port=1234,addr.ipv4-off: warning: short-form boolean option 'addr.ipv4-off' deprecated
>      Please use addr.ipv4-off=on instead
>      qemu-system-x86_64: -netdev type=stream,id=foo,addr.type=inet,addr.host=localhost,addr.port=1234,addr.ipv4-off: Parameter 'type' is missing
> 
> We get this because netdev_is_modern() guesses wrongly: keyval_parse()
> fails with the perfectly reasonable error message "Expected '=' after
> parameter 'addr.ipv4-off'", but netdev_is_modern() ignores the error,
> and fails.  We fall back to QemuOpts, and confusion ensues.
> 
> I'm not sure we can do much better with reasonable effort.  If we decide
> to accept this behavior, it should be documented at least in the source
> code.

What about using modern syntax by default?

     args = keyval_parse(optarg, "type", NULL, NULL);
     if (!args) {
         /* cannot detect the syntax, use new style syntax */
         return true;
     }

>>   
>>   /*
>> diff --git a/net/stream.c b/net/stream.c
>> new file mode 100644
>> index 000000000000..fdc97ee43a56
>> --- /dev/null
>> +++ b/net/stream.c
>> @@ -0,0 +1,425 @@
>> +/*
>> + * QEMU System Emulator
>> + *
>> + * Copyright (c) 2003-2008 Fabrice Bellard
>> + *
>> + * Permission is hereby granted, free of charge, to any person obtaining a copy
>> + * of this software and associated documentation files (the "Software"), to deal
>> + * in the Software without restriction, including without limitation the rights
>> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
>> + * copies of the Software, and to permit persons to whom the Software is
>> + * furnished to do so, subject to the following conditions:
>> + *
>> + * The above copyright notice and this permission notice shall be included in
>> + * all copies or substantial portions of the Software.
>> + *
>> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
>> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
>> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
>> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
>> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
>> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
>> + * THE SOFTWARE.
>> + */
> 
> Blank line here, please.

Done

...
>> diff --git a/qapi/net.json b/qapi/net.json
>> index d6f7cfd4d656..5f72995b1d24 100644
>> --- a/qapi/net.json
>> +++ b/qapi/net.json
...
>> @@ -566,6 +567,37 @@
>>       '*isolated':  'bool' },
>>     'if': 'CONFIG_VMNET' }
>>   
>> +##
>> +# @NetdevStreamOptions:
>> +#
>> +# Configuration info for stream socket netdev
>> +#
>> +# @addr: socket address to listen on (server=true)
>> +#        or connect to (server=false)
>> +# @server: create server socket (default: true)
>> +#
>> +# Since: 7.1
>> +##
>> +{ 'struct': 'NetdevStreamOptions',
>> +  'data': {
>> +    'addr':   'SocketAddress',
>> +    '*server': 'bool' } }
>> +
>> +##
>> +# @NetdevDgramOptions:
>> +#
>> +# Configuration info for datagram socket netdev.
>> +#
>> +# @remote: remote address
>> +# @local: local address
>> +#
>> +# Since: 7.1
>> +##
>> +{ 'struct': 'NetdevDgramOptions',
>> +  'data': {
>> +    '*local':  'SocketAddress',
>> +    '*remote': 'SocketAddress' } }
> 
> In review of v2, I inquired about behavior when members are absent.
> You wrote:
> 
>      The code checks there is at least one of these options and reports an error if not.
> 
>      if remote address is present and it's a multicast address, local address is optional.
> 
>      otherwise local address is required and remote address is optional.
> 
> Please work that into the doc comment.

OK

> 
>> +
>>   ##
>>   # @NetClientDriver:
>>   #
>> @@ -579,9 +611,9 @@
>>   #        @vmnet-bridged since 7.1
>>   ##
>>   { 'enum': 'NetClientDriver',
>> -  'data': [ 'none', 'nic', 'user', 'tap', 'l2tpv3', 'socket', 'vde',
>> -            'bridge', 'hubport', 'netmap', 'vhost-user', 'vhost-vdpa',
>> -            { 'name': 'vmnet-host', 'if': 'CONFIG_VMNET' },
>> +  'data': [ 'none', 'nic', 'user', 'tap', 'l2tpv3', 'socket', 'stream',
>> +            'dgram', 'vde', 'bridge', 'hubport', 'netmap', 'vhost-user',
>> +            'vhost-vdpa', { 'name': 'vmnet-host', 'if': 'CONFIG_VMNET' },
>>               { 'name': 'vmnet-shared', 'if': 'CONFIG_VMNET' },
>>               { 'name': 'vmnet-bridged', 'if': 'CONFIG_VMNET' }] }
> 
> Opportunity to put vmnet-host on its own line for readability.
> 

OK

Thanks,
Laurent



^ permalink raw reply	[flat|nested] 28+ messages in thread

* Re: [RFC PATCH v3 00/11] qapi: net: add unix socket type support to netdev backend
  2022-06-20 10:18 [RFC PATCH v3 00/11] qapi: net: add unix socket type support to netdev backend Laurent Vivier
                   ` (10 preceding siblings ...)
  2022-06-20 10:18 ` [RFC PATCH v3 11/11] net: stream: move to QIO Laurent Vivier
@ 2022-06-20 18:24 ` Dr. David Alan Gilbert
  2022-06-21  9:51   ` Laurent Vivier
  11 siblings, 1 reply; 28+ messages in thread
From: Dr. David Alan Gilbert @ 2022-06-20 18:24 UTC (permalink / raw)
  To: Laurent Vivier
  Cc: qemu-devel, Markus Armbruster, Eric Blake, Paolo Bonzini,
	Daniel P. Berrangé,
	Jason Wang, Ralph Schmieder, Stefano Brivio

* Laurent Vivier (lvivier@redhat.com) wrote:
> "-netdev socket" only supports inet sockets.
> 
> It's not a complex task to add support for unix sockets, but
> the socket netdev parameters are not defined to manage well unix
> socket parameters.
> 
> As discussed in:
> 
>   "socket.c added support for unix domain socket datagram transport"
>   https://lore.kernel.org/qemu-devel/1C0E1BC5-904F-46B0-8044-68E43E67BE60@gmail.com/
> 
> This series adds support of unix socket type using SocketAddress QAPI structure.
> 
> Two new netdev backends, "stream" and "dgram" are added, that are barely a copy of "socket"
> backend but they use the SocketAddress QAPI to provide socket parameters.
> And then they also implement unix sockets (TCP and UDP).

Had you considered a -netdev chardev?

Dave

> Some examples of CLI syntax:
> 
>   for TCP:
> 
>   -netdev stream,id=socket0,addr.type=inet,addr.host=localhost,addr.port=1234
>   -netdev stream,id=socket0,server=off,addr.type=inet,addr.host=localhost,addr.port=1234
> 
>   -netdev dgram,id=socket0,\
>           local.type=inet,local.host=localhost,local.port=1234,\
>           remote.type=inet,remote.host=localhost,remote.port=1235
> 
>   for UNIX:
> 
>   -netdev stream,id=socket0,addr.type=unix,addr.path=/tmp/qemu0
>   -netdev stream,id=socket0,server=off,addr.type=unix,addr.path=/tmp/qemu0
> 
>   -netdev dgram,id=socket0,\
>           local.type=unix,local.path=/tmp/qemu0,\
>           remote.type=unix,remote.path=/tmp/qemu1
> 
>   for FD:
> 
>   -netdev stream,id=socket0,addr.type=fd,addr.str=4
>   -netdev stream,id=socket0,server=off,addr.type=fd,addr.str=5
> 
>   -netdev dgram,id=socket0,local.type=fd,addr.str=4
> 
> v3:
>   - remove support of "-net" for dgram and stream. They are only
>     supported with "-netdev" option.
>   - use &error_fatal directly in net_client_inits()
>   - update qemu-options.hx
>   - move to QIO for stream socket
> 
> v2:
>   - use "stream" and "dgram" rather than "socket-ng,mode=stream"
>     and ""socket-ng,mode=dgram"
>   - extract code to bypass qemu_opts_parse_noisily() to
>     a new patch
>   - do not ignore EINVAL (Stefano)
>   - fix "-net" option
> 
> CC: Ralph Schmieder <ralph.schmieder@gmail.com>
> CC: Stefano Brivio <sbrivio@redhat.com>
> CC: Daniel P. Berrangé <berrange@redhat.com>
> CC: Markus Armbruster <armbru@redhat.com>
> 
> Laurent Vivier (10):
>   net: introduce convert_host_port()
>   net: remove the @errp argument of net_client_inits()
>   qapi: net: introduce a way to bypass qemu_opts_parse_noisily()
>   qapi: net: add stream and dgram netdevs
>   net: stream: add unix socket
>   net: dgram: make dgram_dst generic
>   net: dgram: move mcast specific code from net_socket_fd_init_dgram()
>   net: dgram: add unix socket
>   qemu-sockets: introduce socket_uri()
>   net: stream: move to QIO
> 
> Stefano Brivio (1):
>   net: stream: Don't ignore EINVAL on netdev socket connection
> 
>  hmp-commands.hx        |   2 +-
>  include/net/net.h      |   3 +-
>  include/qemu/sockets.h |   4 +-
>  monitor/hmp-cmds.c     |  23 +-
>  net/clients.h          |   6 +
>  net/dgram.c            | 706 +++++++++++++++++++++++++++++++++++++++++
>  net/hub.c              |   2 +
>  net/meson.build        |   2 +
>  net/net.c              | 149 ++++++---
>  net/stream.c           | 371 ++++++++++++++++++++++
>  qapi/net.json          |  40 ++-
>  qemu-options.hx        |  12 +
>  softmmu/vl.c           |   5 +-
>  util/qemu-sockets.c    |  20 ++
>  14 files changed, 1277 insertions(+), 68 deletions(-)
>  create mode 100644 net/dgram.c
>  create mode 100644 net/stream.c
> 
> -- 
> 2.36.1
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK



^ permalink raw reply	[flat|nested] 28+ messages in thread

* Re: [RFC PATCH v3 04/11] qapi: net: add stream and dgram netdevs
  2022-06-20 17:52     ` Laurent Vivier
@ 2022-06-21  8:49       ` Markus Armbruster
  2022-06-21 19:27         ` Laurent Vivier
  0 siblings, 1 reply; 28+ messages in thread
From: Markus Armbruster @ 2022-06-21  8:49 UTC (permalink / raw)
  To: Laurent Vivier
  Cc: qemu-devel, Eric Blake, Dr. David Alan Gilbert, Paolo Bonzini,
	Daniel P. Berrangé,
	Jason Wang, Stefano Brivio

Laurent Vivier <lvivier@redhat.com> writes:

> On 20/06/2022 17:21, Markus Armbruster wrote:
>> Laurent Vivier <lvivier@redhat.com> writes:
>> 
>>> Copied from socket netdev file and modified to use SocketAddress
>>> to be able to introduce new features like unix socket.
>>>
>>> "udp" and "mcast" are squashed into dgram netdev, multicast is detected
>>> according to the IP address type.
>>> "listen" and "connect" modes are managed by stream netdev. An optional
>>> parameter "server" defines the mode (server by default)
>>>
>>> Signed-off-by: Laurent Vivier <lvivier@redhat.com>
>>> Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
>>> ---

[...]

>>> diff --git a/net/net.c b/net/net.c
>>> index c337d3d753fe..440957b272ee 100644
>>> --- a/net/net.c
>>> +++ b/net/net.c
> ...
>>> @@ -1612,7 +1617,19 @@ void net_init_clients(void)
>>>    */
>>>   static bool netdev_is_modern(const char *optarg)
>>>   {
>>> -    return false;
>>> +    QDict *args;
>>> +    const char *type;
>>> +    bool is_modern;
>>> +
>>> +    args = keyval_parse(optarg, "type", NULL, NULL);
>>> +    if (!args) {
>>> +        return false;
>>> +    }
>>> +    type = qdict_get_try_str(args, "type");
>>> +    is_modern = !g_strcmp0(type, "stream") || !g_strcmp0(type, "dgram");
>>> +    qobject_unref(args);
>>> +
>>> +    return is_modern;
>>>   }
>> 
>> You could use g_autoptr here:
>> 
>>         g_autoptr(QDict) args = NULL;
>>         const char *type;
>>         bool is_modern;
>> 
>>         args = keyval_parse(optarg, "type", NULL, NULL);
>>         if (!args) {
>>             return false;
>>         }
>>         type = qdict_get_try_str(args, "type");
>>         return !g_strcmp0(type, "stream") || !g_strcmp0(type, "dgram");
>> 
>> Matter of taste; you decide.
>
> Looks good. We already had some series to convert existing code to g_autoptr(), so it 
> seems the way to do.
>
>> 
>> Now recall how this function is used: it decides whether to parse the
>> modern way (with qobject_input_visitor_new_str()) or the traditional way
>> (with qemu_opts_parse_noisily()).
>> 
>> qemu_opts_parse_noisily() parses into a QemuOpts, for later use with the
>> opts visitor.
>> 
>> qobject_input_visitor_new_str() supports both dotted keys and JSON.  The
>> former is parsed with keyval_parse(), the latter with
>> qobject_from_json().  It returns the resulting parse tree wrapped in a
>> suitable QAPI input visitor.
>> 
>> Issue 1: since we get there only when keyval_parse() succeeds, JSON is
>> unreachable.  Reproducer:
>> 
>>      $ qemu-system-x86_64 -netdev '{"id":"foo"}'
>>      upstream-qemu: -netdev {"id":"foo"}: Parameter 'id' is missing
>> 
>> This is parsed with qemu_opts_parse_noisily(), resulting in a QemuOpts
>> with a single option 'type' with value '{"id":"foo"}'.  The error
>> message comes from the opts visitor.
>> 
>> To fix this, make netdev_is_modern() return true when optarg[0] == '{'.
>> This matches how qobject_input_visitor_new_str() recognizes JSON.
>
> OK
>
>> 
>> Issue 2: when keyval_parse() detects an error, we throw it away and fall
>> back to QemuOpts.  This is commonly what we want.  But not always.  For
>> instance:
>> 
>>      $ qemu-system-x86_64 -netdev 'type=stream,id=foo,addr.type=inet,addr.host=localhost,addr.port=1234,addr.ipv4-off'
>> 
>> Note the typo "ipv4-off" instead of ipv4=off.  The error reporting is crap:
>> 
>>      qemu-system-x86_64: -netdev type=stream,id=foo,addr.type=inet,addr.host=localhost,addr.port=1234,addr.ipv4-off: warning: short-form boolean option 'addr.ipv4-off' deprecated
>>      Please use addr.ipv4-off=on instead
>>      qemu-system-x86_64: -netdev type=stream,id=foo,addr.type=inet,addr.host=localhost,addr.port=1234,addr.ipv4-off: Parameter 'type' is missing
>> 
>> We get this because netdev_is_modern() guesses wrongly: keyval_parse()
>> fails with the perfectly reasonable error message "Expected '=' after
>> parameter 'addr.ipv4-off'", but netdev_is_modern() ignores the error,
>> and fails.  We fall back to QemuOpts, and confusion ensues.
>> 
>> I'm not sure we can do much better with reasonable effort.  If we decide
>> to accept this behavior, it should be documented at least in the source
>> code.
>
> What about using modern syntax by default?
>
>      args = keyval_parse(optarg, "type", NULL, NULL);
>      if (!args) {
>          /* cannot detect the syntax, use new style syntax */
>          return true;
>      }

As is, netdev_is_modern() has three cases:

1. keyval_parse() fails

2. keyval_parse() succeeds, but value of @type is not modern

3. keyval_parse() succeeds, and value of @type is modern

In case 3. we're sure, because even if qemu_opts_parse_noisily() also
succeeded, it would result in the same value of @type.

In case 2, assuming traditional seems reasonable.  The assumption can be
wrong when the user intends modern, but fat-fingers the type=T part.

In case 1, we know nothing.

Guessing modern is wrong when the user intends traditional.  This
happens when a meant-to-be-traditional @optarg also parses as modern.
Quite possible.

Guessing traditional is wrong when the user intends modern.  This
happens when a meant-to-be-modern @optarg fails to parse as modern,
i.e. whenever the user screws up modern syntax.

Which guess is less bad?  I'm not sure.  Thoughts?

Note that additionally checking whether qemu_opts_parse() succeeds would
be next to useless, since qemu_opts_parse() accepts pretty much
anything.

[...]



^ permalink raw reply	[flat|nested] 28+ messages in thread

* Re: [RFC PATCH v3 00/11] qapi: net: add unix socket type support to netdev backend
  2022-06-20 18:24 ` [RFC PATCH v3 00/11] qapi: net: add unix socket type support to netdev backend Dr. David Alan Gilbert
@ 2022-06-21  9:51   ` Laurent Vivier
  2022-06-21 10:31     ` Dr. David Alan Gilbert
  0 siblings, 1 reply; 28+ messages in thread
From: Laurent Vivier @ 2022-06-21  9:51 UTC (permalink / raw)
  To: Dr. David Alan Gilbert
  Cc: qemu-devel, Markus Armbruster, Eric Blake, Paolo Bonzini,
	Daniel P. Berrangé,
	Jason Wang, Ralph Schmieder, Stefano Brivio

On 20/06/2022 20:24, Dr. David Alan Gilbert wrote:
> * Laurent Vivier (lvivier@redhat.com) wrote:
>> "-netdev socket" only supports inet sockets.
>>
>> It's not a complex task to add support for unix sockets, but
>> the socket netdev parameters are not defined to manage well unix
>> socket parameters.
>>
>> As discussed in:
>>
>>    "socket.c added support for unix domain socket datagram transport"
>>    https://lore.kernel.org/qemu-devel/1C0E1BC5-904F-46B0-8044-68E43E67BE60@gmail.com/
>>
>> This series adds support of unix socket type using SocketAddress QAPI structure.
>>
>> Two new netdev backends, "stream" and "dgram" are added, that are barely a copy of "socket"
>> backend but they use the SocketAddress QAPI to provide socket parameters.
>> And then they also implement unix sockets (TCP and UDP).
> 
> Had you considered a -netdev chardev?
> 

I think by definition a "chardev" doesn't behave like a "netdev". Moreover "chardev" is 
already a frontend for several backends (socket, udp, ...), this would mean we use the 
frontend "chardev" as a backend of a "netdev". More and more layers...

And in the case of "-netdev dgram", we can use unix socket and sendto()/recv() while 
something like "-chardev udp,id=char0 -netdev chardev,chardev=char0,id=net0" doesn't 
support unix (see qio_channel_socket_dgram_sync()/socket_dgram()) and uses a 
"connect()/sendmsg()/recv()" (that really changes the behaviour of the backend)

The aim of this series is to add unix socket support.

Thanks,
Laurent



^ permalink raw reply	[flat|nested] 28+ messages in thread

* Re: [RFC PATCH v3 00/11] qapi: net: add unix socket type support to netdev backend
  2022-06-21  9:51   ` Laurent Vivier
@ 2022-06-21 10:31     ` Dr. David Alan Gilbert
  2022-06-21 10:54       ` Daniel P. Berrangé
  0 siblings, 1 reply; 28+ messages in thread
From: Dr. David Alan Gilbert @ 2022-06-21 10:31 UTC (permalink / raw)
  To: Laurent Vivier
  Cc: qemu-devel, Markus Armbruster, Eric Blake, Paolo Bonzini,
	Daniel P. Berrangé,
	Jason Wang, Ralph Schmieder, Stefano Brivio

* Laurent Vivier (lvivier@redhat.com) wrote:
> On 20/06/2022 20:24, Dr. David Alan Gilbert wrote:
> > * Laurent Vivier (lvivier@redhat.com) wrote:
> > > "-netdev socket" only supports inet sockets.
> > > 
> > > It's not a complex task to add support for unix sockets, but
> > > the socket netdev parameters are not defined to manage well unix
> > > socket parameters.
> > > 
> > > As discussed in:
> > > 
> > >    "socket.c added support for unix domain socket datagram transport"
> > >    https://lore.kernel.org/qemu-devel/1C0E1BC5-904F-46B0-8044-68E43E67BE60@gmail.com/
> > > 
> > > This series adds support of unix socket type using SocketAddress QAPI structure.
> > > 
> > > Two new netdev backends, "stream" and "dgram" are added, that are barely a copy of "socket"
> > > backend but they use the SocketAddress QAPI to provide socket parameters.
> > > And then they also implement unix sockets (TCP and UDP).
> > 
> > Had you considered a -netdev chardev?
> > 
> 
> I think by definition a "chardev" doesn't behave like a "netdev". Moreover
> "chardev" is already a frontend for several backends (socket, udp, ...),
> this would mean we use the frontend "chardev" as a backend of a "netdev".
> More and more layers...

Yeh definitely more layers; but perhaps avoiding some duplication.

> And in the case of "-netdev dgram", we can use unix socket and
> sendto()/recv() while something like "-chardev udp,id=char0 -netdev
> chardev,chardev=char0,id=net0" doesn't support unix (see
> qio_channel_socket_dgram_sync()/socket_dgram()) and uses a
> "connect()/sendmsg()/recv()" (that really changes the behaviour of the
> backend)

It was -chardev socket, path=/unix/socket/path    that I was thinking
of; -chardev socket supports both tcp and unix already.

> The aim of this series is to add unix socket support.

Yes.

Dave

> Thanks,
> Laurent
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK



^ permalink raw reply	[flat|nested] 28+ messages in thread

* Re: [RFC PATCH v3 00/11] qapi: net: add unix socket type support to netdev backend
  2022-06-21 10:31     ` Dr. David Alan Gilbert
@ 2022-06-21 10:54       ` Daniel P. Berrangé
  2022-06-21 12:16         ` Dr. David Alan Gilbert
  0 siblings, 1 reply; 28+ messages in thread
From: Daniel P. Berrangé @ 2022-06-21 10:54 UTC (permalink / raw)
  To: Dr. David Alan Gilbert
  Cc: Laurent Vivier, qemu-devel, Markus Armbruster, Eric Blake,
	Paolo Bonzini, Jason Wang, Ralph Schmieder, Stefano Brivio

On Tue, Jun 21, 2022 at 11:31:36AM +0100, Dr. David Alan Gilbert wrote:
> * Laurent Vivier (lvivier@redhat.com) wrote:
> > On 20/06/2022 20:24, Dr. David Alan Gilbert wrote:
> > > * Laurent Vivier (lvivier@redhat.com) wrote:
> > > > "-netdev socket" only supports inet sockets.
> > > > 
> > > > It's not a complex task to add support for unix sockets, but
> > > > the socket netdev parameters are not defined to manage well unix
> > > > socket parameters.
> > > > 
> > > > As discussed in:
> > > > 
> > > >    "socket.c added support for unix domain socket datagram transport"
> > > >    https://lore.kernel.org/qemu-devel/1C0E1BC5-904F-46B0-8044-68E43E67BE60@gmail.com/
> > > > 
> > > > This series adds support of unix socket type using SocketAddress QAPI structure.
> > > > 
> > > > Two new netdev backends, "stream" and "dgram" are added, that are barely a copy of "socket"
> > > > backend but they use the SocketAddress QAPI to provide socket parameters.
> > > > And then they also implement unix sockets (TCP and UDP).
> > > 
> > > Had you considered a -netdev chardev?
> > > 
> > 
> > I think by definition a "chardev" doesn't behave like a "netdev". Moreover
> > "chardev" is already a frontend for several backends (socket, udp, ...),
> > this would mean we use the frontend "chardev" as a backend of a "netdev".
> > More and more layers...
> 
> Yeh definitely more layers; but perhaps avoiding some duplication.
> 
> > And in the case of "-netdev dgram", we can use unix socket and
> > sendto()/recv() while something like "-chardev udp,id=char0 -netdev
> > chardev,chardev=char0,id=net0" doesn't support unix (see
> > qio_channel_socket_dgram_sync()/socket_dgram()) and uses a
> > "connect()/sendmsg()/recv()" (that really changes the behaviour of the
> > backend)
> 
> It was -chardev socket, path=/unix/socket/path    that I was thinking
> of; -chardev socket supports both tcp and unix already.

IMHO we've over-used & abused chardevs in contexts where we really
should not have done. The chardev API is passable when all you need
is a persistent bidirectional channel, but is a really bad fit for
backends wanting to be aware of the dynamic connection oriented
semantics that sockets offer. The hoops we've had to jump through
in places to deal with having chardevs open asynchronously or deal
with automatic chardev re-connection is quite gross.

Chardev in the past was convenient to use, because we were not so
great at doing CLI syntax modelling & implementation, so it was
useful to re-use the chardev code for socket address handling on
the CLI.  We also didn't historically have nice APIs for dealing
with sockets - if you didn't use chardevs, you were stuck with
the raw sockets APIs. With our aim for CLI to be modelled &
implemented with QAPI these days, that benefit of re-using chardevs
for CLI is largely eliminated.  With our QIOChannel APIs, the
benefits of re-using chardevs from an impl POV is also largely
eliminated.


With regards,
Daniel
-- 
|: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org         -o-            https://fstop138.berrange.com :|
|: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange :|



^ permalink raw reply	[flat|nested] 28+ messages in thread

* Re: [RFC PATCH v3 00/11] qapi: net: add unix socket type support to netdev backend
  2022-06-21 10:54       ` Daniel P. Berrangé
@ 2022-06-21 12:16         ` Dr. David Alan Gilbert
  0 siblings, 0 replies; 28+ messages in thread
From: Dr. David Alan Gilbert @ 2022-06-21 12:16 UTC (permalink / raw)
  To: Daniel P. Berrangé
  Cc: Laurent Vivier, qemu-devel, Markus Armbruster, Eric Blake,
	Paolo Bonzini, Jason Wang, Ralph Schmieder, Stefano Brivio

* Daniel P. Berrangé (berrange@redhat.com) wrote:
> On Tue, Jun 21, 2022 at 11:31:36AM +0100, Dr. David Alan Gilbert wrote:
> > * Laurent Vivier (lvivier@redhat.com) wrote:
> > > On 20/06/2022 20:24, Dr. David Alan Gilbert wrote:
> > > > * Laurent Vivier (lvivier@redhat.com) wrote:
> > > > > "-netdev socket" only supports inet sockets.
> > > > > 
> > > > > It's not a complex task to add support for unix sockets, but
> > > > > the socket netdev parameters are not defined to manage well unix
> > > > > socket parameters.
> > > > > 
> > > > > As discussed in:
> > > > > 
> > > > >    "socket.c added support for unix domain socket datagram transport"
> > > > >    https://lore.kernel.org/qemu-devel/1C0E1BC5-904F-46B0-8044-68E43E67BE60@gmail.com/
> > > > > 
> > > > > This series adds support of unix socket type using SocketAddress QAPI structure.
> > > > > 
> > > > > Two new netdev backends, "stream" and "dgram" are added, that are barely a copy of "socket"
> > > > > backend but they use the SocketAddress QAPI to provide socket parameters.
> > > > > And then they also implement unix sockets (TCP and UDP).
> > > > 
> > > > Had you considered a -netdev chardev?
> > > > 
> > > 
> > > I think by definition a "chardev" doesn't behave like a "netdev". Moreover
> > > "chardev" is already a frontend for several backends (socket, udp, ...),
> > > this would mean we use the frontend "chardev" as a backend of a "netdev".
> > > More and more layers...
> > 
> > Yeh definitely more layers; but perhaps avoiding some duplication.
> > 
> > > And in the case of "-netdev dgram", we can use unix socket and
> > > sendto()/recv() while something like "-chardev udp,id=char0 -netdev
> > > chardev,chardev=char0,id=net0" doesn't support unix (see
> > > qio_channel_socket_dgram_sync()/socket_dgram()) and uses a
> > > "connect()/sendmsg()/recv()" (that really changes the behaviour of the
> > > backend)
> > 
> > It was -chardev socket, path=/unix/socket/path    that I was thinking
> > of; -chardev socket supports both tcp and unix already.
> 
> IMHO we've over-used & abused chardevs in contexts where we really
> should not have done. The chardev API is passable when all you need
> is a persistent bidirectional channel, but is a really bad fit for
> backends wanting to be aware of the dynamic connection oriented
> semantics that sockets offer. The hoops we've had to jump through
> in places to deal with having chardevs open asynchronously or deal
> with automatic chardev re-connection is quite gross.
> 
> Chardev in the past was convenient to use, because we were not so
> great at doing CLI syntax modelling & implementation, so it was
> useful to re-use the chardev code for socket address handling on
> the CLI.  We also didn't historically have nice APIs for dealing
> with sockets - if you didn't use chardevs, you were stuck with
> the raw sockets APIs. With our aim for CLI to be modelled &
> implemented with QAPI these days, that benefit of re-using chardevs
> for CLI is largely eliminated.  With our QIOChannel APIs, the
> benefits of re-using chardevs from an impl POV is also largely
> eliminated.

OK, fair enough.

Dave

> 
> With regards,
> Daniel
> -- 
> |: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
> |: https://libvirt.org         -o-            https://fstop138.berrange.com :|
> |: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange :|
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK



^ permalink raw reply	[flat|nested] 28+ messages in thread

* Re: [RFC PATCH v3 04/11] qapi: net: add stream and dgram netdevs
  2022-06-21  8:49       ` Markus Armbruster
@ 2022-06-21 19:27         ` Laurent Vivier
  2022-06-22 11:47           ` Markus Armbruster
  0 siblings, 1 reply; 28+ messages in thread
From: Laurent Vivier @ 2022-06-21 19:27 UTC (permalink / raw)
  To: Markus Armbruster
  Cc: qemu-devel, Eric Blake, Dr. David Alan Gilbert, Paolo Bonzini,
	Daniel P. Berrangé,
	Jason Wang, Stefano Brivio

On 21/06/2022 10:49, Markus Armbruster wrote:
> Laurent Vivier <lvivier@redhat.com> writes:
> 
>> On 20/06/2022 17:21, Markus Armbruster wrote:
>>> Laurent Vivier <lvivier@redhat.com> writes:
>>>
>>>> Copied from socket netdev file and modified to use SocketAddress
>>>> to be able to introduce new features like unix socket.
>>>>
>>>> "udp" and "mcast" are squashed into dgram netdev, multicast is detected
>>>> according to the IP address type.
>>>> "listen" and "connect" modes are managed by stream netdev. An optional
>>>> parameter "server" defines the mode (server by default)
>>>>
>>>> Signed-off-by: Laurent Vivier <lvivier@redhat.com>
>>>> Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
>>>> ---
> 
> [...]
> 
>>>> diff --git a/net/net.c b/net/net.c
>>>> index c337d3d753fe..440957b272ee 100644
>>>> --- a/net/net.c
>>>> +++ b/net/net.c
>> ...
>>>> @@ -1612,7 +1617,19 @@ void net_init_clients(void)
>>>>     */
>>>>    static bool netdev_is_modern(const char *optarg)
>>>>    {
>>>> -    return false;
>>>> +    QDict *args;
>>>> +    const char *type;
>>>> +    bool is_modern;
>>>> +
>>>> +    args = keyval_parse(optarg, "type", NULL, NULL);
>>>> +    if (!args) {
>>>> +        return false;
>>>> +    }
>>>> +    type = qdict_get_try_str(args, "type");
>>>> +    is_modern = !g_strcmp0(type, "stream") || !g_strcmp0(type, "dgram");
>>>> +    qobject_unref(args);
>>>> +
>>>> +    return is_modern;
>>>>    }
>>>
>>> You could use g_autoptr here:
>>>
>>>          g_autoptr(QDict) args = NULL;
>>>          const char *type;
>>>          bool is_modern;
>>>
>>>          args = keyval_parse(optarg, "type", NULL, NULL);
>>>          if (!args) {
>>>              return false;
>>>          }
>>>          type = qdict_get_try_str(args, "type");
>>>          return !g_strcmp0(type, "stream") || !g_strcmp0(type, "dgram");
>>>
>>> Matter of taste; you decide.
>>
>> Looks good. We already had some series to convert existing code to g_autoptr(), so it
>> seems the way to do.
>>
>>>
>>> Now recall how this function is used: it decides whether to parse the
>>> modern way (with qobject_input_visitor_new_str()) or the traditional way
>>> (with qemu_opts_parse_noisily()).
>>>
>>> qemu_opts_parse_noisily() parses into a QemuOpts, for later use with the
>>> opts visitor.
>>>
>>> qobject_input_visitor_new_str() supports both dotted keys and JSON.  The
>>> former is parsed with keyval_parse(), the latter with
>>> qobject_from_json().  It returns the resulting parse tree wrapped in a
>>> suitable QAPI input visitor.
>>>
>>> Issue 1: since we get there only when keyval_parse() succeeds, JSON is
>>> unreachable.  Reproducer:
>>>
>>>       $ qemu-system-x86_64 -netdev '{"id":"foo"}'
>>>       upstream-qemu: -netdev {"id":"foo"}: Parameter 'id' is missing
>>>
>>> This is parsed with qemu_opts_parse_noisily(), resulting in a QemuOpts
>>> with a single option 'type' with value '{"id":"foo"}'.  The error
>>> message comes from the opts visitor.
>>>
>>> To fix this, make netdev_is_modern() return true when optarg[0] == '{'.
>>> This matches how qobject_input_visitor_new_str() recognizes JSON.
>>
>> OK
>>
>>>
>>> Issue 2: when keyval_parse() detects an error, we throw it away and fall
>>> back to QemuOpts.  This is commonly what we want.  But not always.  For
>>> instance:
>>>
>>>       $ qemu-system-x86_64 -netdev 'type=stream,id=foo,addr.type=inet,addr.host=localhost,addr.port=1234,addr.ipv4-off'
>>>
>>> Note the typo "ipv4-off" instead of ipv4=off.  The error reporting is crap:
>>>
>>>       qemu-system-x86_64: -netdev type=stream,id=foo,addr.type=inet,addr.host=localhost,addr.port=1234,addr.ipv4-off: warning: short-form boolean option 'addr.ipv4-off' deprecated
>>>       Please use addr.ipv4-off=on instead
>>>       qemu-system-x86_64: -netdev type=stream,id=foo,addr.type=inet,addr.host=localhost,addr.port=1234,addr.ipv4-off: Parameter 'type' is missing
>>>
>>> We get this because netdev_is_modern() guesses wrongly: keyval_parse()
>>> fails with the perfectly reasonable error message "Expected '=' after
>>> parameter 'addr.ipv4-off'", but netdev_is_modern() ignores the error,
>>> and fails.  We fall back to QemuOpts, and confusion ensues.
>>>
>>> I'm not sure we can do much better with reasonable effort.  If we decide
>>> to accept this behavior, it should be documented at least in the source
>>> code.
>>
>> What about using modern syntax by default?
>>
>>       args = keyval_parse(optarg, "type", NULL, NULL);
>>       if (!args) {
>>           /* cannot detect the syntax, use new style syntax */
>>           return true;
>>       }
> 
> As is, netdev_is_modern() has three cases:
> 
> 1. keyval_parse() fails
> 
> 2. keyval_parse() succeeds, but value of @type is not modern
> 
> 3. keyval_parse() succeeds, and value of @type is modern
> 
> In case 3. we're sure, because even if qemu_opts_parse_noisily() also
> succeeded, it would result in the same value of @type.
> 
> In case 2, assuming traditional seems reasonable.  The assumption can be
> wrong when the user intends modern, but fat-fingers the type=T part.
> 
> In case 1, we know nothing.
> 
> Guessing modern is wrong when the user intends traditional.  This
> happens when a meant-to-be-traditional @optarg also parses as modern.
> Quite possible.

I don't see why keyval_parse() fails in this case. Any example?

> Guessing traditional is wrong when the user intends modern.  This
> happens when a meant-to-be-modern @optarg fails to parse as modern,
> i.e. whenever the user screws up modern syntax.

This one is the example you gave (ipv4-off)

> Which guess is less bad?  I'm not sure.  Thoughts?

Perhaps we can simply fail if keyval_parse() fails?

something like:

     args = keyval_parse(optarg, "type", NULL, &error_fatal);
     type = qdict_get_try_str(args, "type");
     return !g_strcmp0(type, "stream") || !g_strcmp0(type, "dgram");

Thanks,
Laurent





^ permalink raw reply	[flat|nested] 28+ messages in thread

* Re: [RFC PATCH v3 03/11] qapi: net: introduce a way to bypass qemu_opts_parse_noisily()
  2022-06-20 10:18 ` [RFC PATCH v3 03/11] qapi: net: introduce a way to bypass qemu_opts_parse_noisily() Laurent Vivier
  2022-06-20 12:43   ` Markus Armbruster
@ 2022-06-22  8:00   ` Markus Armbruster
  1 sibling, 0 replies; 28+ messages in thread
From: Markus Armbruster @ 2022-06-22  8:00 UTC (permalink / raw)
  To: Laurent Vivier
  Cc: qemu-devel, Eric Blake, Dr. David Alan Gilbert, Paolo Bonzini,
	Daniel P. Berrangé,
	Jason Wang

Laurent Vivier <lvivier@redhat.com> writes:

> As qemu_opts_parse_noisily() flattens the QAPI structures ("type" field
> of Netdev structure can collides with "type" field of SocketAddress),
> we introduce a way to bypass qemu_opts_parse_noisily() and use directly
> visit_type_Netdev() to parse the backend parameters.
>
> More details from Markus:
>
> qemu_init() passes the argument of -netdev, -nic, and -net to
> net_client_parse().
>
> net_client_parse() parses with qemu_opts_parse_noisily(), passing
> QemuOptsList qemu_netdev_opts for -netdev, qemu_nic_opts for -nic, and
> qemu_net_opts for -net.  Their desc[] are all empty, which means any
> keys are accepted.  The result of the parse (a QemuOpts) is stored in
> the QemuOptsList.
>
> Note that QemuOpts is flat by design.  In some places, we layer non-flat
> on top using dotted keys convention, but not here.
>
> net_init_clients() iterates over the stored QemuOpts, and passes them to
> net_init_netdev(), net_param_nic(), or net_init_client(), respectively.
>
> These functions pass the QemuOpts to net_client_init().  They also do
> other things with the QemuOpts, which we can ignore here.
>
> net_client_init() uses the opts visitor to convert the (flat) QemOpts to
> a (non-flat) QAPI object Netdev.  Netdev is also the argument of QMP
> command netdev_add.
>
> The opts visitor was an early attempt to support QAPI in
> (QemuOpts-based) CLI.  It restricts QAPI types to a certain shape; see
> commit eb7ee2cbeb "qapi: introduce OptsVisitor".
>
> A more modern way to support QAPI is qobject_input_visitor_new_str().
> It uses keyval_parse() instead of QemuOpts for KEY=VALUE,... syntax, and
> it also supports JSON syntax.  The former isn't quite as expressive as
> JSON, but it's a lot closer than QemuOpts + opts visitor.
>
> This commit paves the way to use of the modern way instead.
>
> Signed-off-by: Laurent Vivier <lvivier@redhat.com>
> ---
>  include/net/net.h |  1 +
>  net/net.c         | 60 +++++++++++++++++++++++++++++++++++++++++++++++
>  softmmu/vl.c      |  3 ++-
>  3 files changed, 63 insertions(+), 1 deletion(-)
>
> diff --git a/include/net/net.h b/include/net/net.h
> index c53c64ac18c4..4ae8ed480f73 100644
> --- a/include/net/net.h
> +++ b/include/net/net.h
> @@ -214,6 +214,7 @@ extern NICInfo nd_table[MAX_NICS];
>  extern const char *host_net_devices[];
>  
>  /* from net.c */
> +int netdev_parse_modern(const char *optarg);
>  int net_client_parse(QemuOptsList *opts_list, const char *str);
>  void show_netdevs(void);
>  void net_init_clients(void);
> diff --git a/net/net.c b/net/net.c
> index 15958f881776..c337d3d753fe 100644
> --- a/net/net.c
> +++ b/net/net.c
> @@ -54,6 +54,7 @@
>  #include "net/colo-compare.h"
>  #include "net/filter.h"
>  #include "qapi/string-output-visitor.h"
> +#include "qapi/qobject-input-visitor.h"
>  
>  /* Net bridge is currently not supported for W32. */
>  #if !defined(_WIN32)
> @@ -63,6 +64,16 @@
>  static VMChangeStateEntry *net_change_state_entry;
>  static QTAILQ_HEAD(, NetClientState) net_clients;
>  
> +typedef struct NetdevQueueEntry {
> +    Netdev *nd;
> +    Location loc;
> +    QSIMPLEQ_ENTRY(NetdevQueueEntry) entry;
> +} NetdevQueueEntry;
> +
> +typedef QSIMPLEQ_HEAD(, NetdevQueueEntry) NetdevQueue;
> +
> +static NetdevQueue nd_queue = QSIMPLEQ_HEAD_INITIALIZER(nd_queue);
> +
>  /***********************************************************/
>  /* network device redirectors */
>  
> @@ -1562,6 +1573,20 @@ out:
>      return ret;
>  }
>  
> +static void netdev_init_modern(void)
> +{
> +    while (!QSIMPLEQ_EMPTY(&nd_queue)) {
> +        NetdevQueueEntry *nd = QSIMPLEQ_FIRST(&nd_queue);
> +
> +        QSIMPLEQ_REMOVE_HEAD(&nd_queue, entry);
> +        loc_push_restore(&nd->loc);
> +        net_client_init1(nd->nd, true, &error_fatal);

Accepts malformed IDs:

    $ qemu-system-x86_64 -netdev type=stream,id=_,addr.type=inet,addr.host=localhost,addr.port=1234
    qemu-system-x86_64: warning: netdev _ has no peer

Compare:

    $ qemu-system-x86_64 -netdev type=user,id=_
    qemu-system-x86_64: -netdev type=user,id=_: Parameter 'id' expects an identifier
    Identifiers consist of letters, digits, '-', '.', '_', starting with a letter.

Calling qmp_netdev_add() instead catches the error.  It won't provide
the hint, though.  Some callers of id_wellformed() do, some don't.
Factoring out bool check_id_wellformed(const char *id, Error **errp)
could make sense.

> +        loc_pop(&nd->loc);
> +        qapi_free_Netdev(nd->nd);
> +        g_free(nd);
> +    }
> +}
> +

[...]



^ permalink raw reply	[flat|nested] 28+ messages in thread

* Re: [RFC PATCH v3 04/11] qapi: net: add stream and dgram netdevs
  2022-06-21 19:27         ` Laurent Vivier
@ 2022-06-22 11:47           ` Markus Armbruster
  2022-06-22 16:18             ` Laurent Vivier
  0 siblings, 1 reply; 28+ messages in thread
From: Markus Armbruster @ 2022-06-22 11:47 UTC (permalink / raw)
  To: Laurent Vivier
  Cc: qemu-devel, Eric Blake, Dr. David Alan Gilbert, Paolo Bonzini,
	Daniel P. Berrangé,
	Jason Wang, Stefano Brivio

Laurent Vivier <lvivier@redhat.com> writes:

> On 21/06/2022 10:49, Markus Armbruster wrote:
>> Laurent Vivier <lvivier@redhat.com> writes:
>> 
>>> On 20/06/2022 17:21, Markus Armbruster wrote:
>>>> Laurent Vivier <lvivier@redhat.com> writes:
>>>>
>>>>> Copied from socket netdev file and modified to use SocketAddress
>>>>> to be able to introduce new features like unix socket.
>>>>>
>>>>> "udp" and "mcast" are squashed into dgram netdev, multicast is detected
>>>>> according to the IP address type.
>>>>> "listen" and "connect" modes are managed by stream netdev. An optional
>>>>> parameter "server" defines the mode (server by default)
>>>>>
>>>>> Signed-off-by: Laurent Vivier <lvivier@redhat.com>
>>>>> Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
>>>>> ---
>> 
>> [...]
>> 
>>>>> diff --git a/net/net.c b/net/net.c
>>>>> index c337d3d753fe..440957b272ee 100644
>>>>> --- a/net/net.c
>>>>> +++ b/net/net.c
>>> ...
>>>>> @@ -1612,7 +1617,19 @@ void net_init_clients(void)
>>>>>     */
>>>>>    static bool netdev_is_modern(const char *optarg)
>>>>>    {
>>>>> -    return false;
>>>>> +    QDict *args;
>>>>> +    const char *type;
>>>>> +    bool is_modern;
>>>>> +
>>>>> +    args = keyval_parse(optarg, "type", NULL, NULL);
>>>>> +    if (!args) {
>>>>> +        return false;
>>>>> +    }
>>>>> +    type = qdict_get_try_str(args, "type");
>>>>> +    is_modern = !g_strcmp0(type, "stream") || !g_strcmp0(type, "dgram");
>>>>> +    qobject_unref(args);
>>>>> +
>>>>> +    return is_modern;
>>>>>    }
>>>>
>>>> You could use g_autoptr here:
>>>>
>>>>          g_autoptr(QDict) args = NULL;
>>>>          const char *type;
>>>>          bool is_modern;
>>>>
>>>>          args = keyval_parse(optarg, "type", NULL, NULL);
>>>>          if (!args) {
>>>>              return false;
>>>>          }
>>>>          type = qdict_get_try_str(args, "type");
>>>>          return !g_strcmp0(type, "stream") || !g_strcmp0(type, "dgram");
>>>>
>>>> Matter of taste; you decide.
>>>
>>> Looks good. We already had some series to convert existing code to g_autoptr(), so it
>>> seems the way to do.
>>>
>>>>
>>>> Now recall how this function is used: it decides whether to parse the
>>>> modern way (with qobject_input_visitor_new_str()) or the traditional way
>>>> (with qemu_opts_parse_noisily()).
>>>>
>>>> qemu_opts_parse_noisily() parses into a QemuOpts, for later use with the
>>>> opts visitor.
>>>>
>>>> qobject_input_visitor_new_str() supports both dotted keys and JSON.  The
>>>> former is parsed with keyval_parse(), the latter with
>>>> qobject_from_json().  It returns the resulting parse tree wrapped in a
>>>> suitable QAPI input visitor.
>>>>
>>>> Issue 1: since we get there only when keyval_parse() succeeds, JSON is
>>>> unreachable.  Reproducer:
>>>>
>>>>       $ qemu-system-x86_64 -netdev '{"id":"foo"}'
>>>>       upstream-qemu: -netdev {"id":"foo"}: Parameter 'id' is missing
>>>>
>>>> This is parsed with qemu_opts_parse_noisily(), resulting in a QemuOpts
>>>> with a single option 'type' with value '{"id":"foo"}'.  The error
>>>> message comes from the opts visitor.
>>>>
>>>> To fix this, make netdev_is_modern() return true when optarg[0] == '{'.
>>>> This matches how qobject_input_visitor_new_str() recognizes JSON.
>>>
>>> OK
>>>
>>>>
>>>> Issue 2: when keyval_parse() detects an error, we throw it away and fall
>>>> back to QemuOpts.  This is commonly what we want.  But not always.  For
>>>> instance:
>>>>
>>>>       $ qemu-system-x86_64 -netdev 'type=stream,id=foo,addr.type=inet,addr.host=localhost,addr.port=1234,addr.ipv4-off'
>>>>
>>>> Note the typo "ipv4-off" instead of ipv4=off.  The error reporting is crap:
>>>>
>>>>       qemu-system-x86_64: -netdev type=stream,id=foo,addr.type=inet,addr.host=localhost,addr.port=1234,addr.ipv4-off: warning: short-form boolean option 'addr.ipv4-off' deprecated
>>>>       Please use addr.ipv4-off=on instead
>>>>       qemu-system-x86_64: -netdev type=stream,id=foo,addr.type=inet,addr.host=localhost,addr.port=1234,addr.ipv4-off: Parameter 'type' is missing
>>>>
>>>> We get this because netdev_is_modern() guesses wrongly: keyval_parse()
>>>> fails with the perfectly reasonable error message "Expected '=' after
>>>> parameter 'addr.ipv4-off'", but netdev_is_modern() ignores the error,
>>>> and fails.  We fall back to QemuOpts, and confusion ensues.
>>>>
>>>> I'm not sure we can do much better with reasonable effort.  If we decide
>>>> to accept this behavior, it should be documented at least in the source
>>>> code.
>>>
>>> What about using modern syntax by default?
>>>
>>>       args = keyval_parse(optarg, "type", NULL, NULL);
>>>       if (!args) {
>>>           /* cannot detect the syntax, use new style syntax */
>>>           return true;
>>>       }
>> 
>> As is, netdev_is_modern() has three cases:
>> 
>> 1. keyval_parse() fails
>> 
>> 2. keyval_parse() succeeds, but value of @type is not modern
>> 
>> 3. keyval_parse() succeeds, and value of @type is modern
>> 
>> In case 3. we're sure, because even if qemu_opts_parse_noisily() also
>> succeeded, it would result in the same value of @type.
>> 
>> In case 2, assuming traditional seems reasonable.  The assumption can be
>> wrong when the user intends modern, but fat-fingers the type=T part.
>> 
>> In case 1, we know nothing.
>> 
>> Guessing modern is wrong when the user intends traditional.  This
>> happens when a meant-to-be-traditional @optarg also parses as modern.
>> Quite possible.
>
> I don't see why keyval_parse() fails in this case. Any example?

Brain cramp on my part, I'm afraid %-}  Let me start over.

Guessing modern is wrong when the user intends traditional.  Two
sub-cases then:

* @optarg parses fine as traditional.  For instance,

    $ qemu-system-x86_64 -netdev type=user,id=foo,ipv4

  parses with a warning:

    option 'ipv4' deprecated
    Please use ipv4=on instead

  This is how current master behaves.

  Guessing modern makes this fail instead:

    qemu-system-x86_64: -netdev type=user,id=foo,ipv4: Expected '=' after parameter 'ipv4'

  Regression.

* @optarg fails to parse traditional, too.  The error reporting is for
  modern even though the user intends traditional.  Can be misleading.
  Example:

    $ qemu-system-x86_64 -netdev type=user,id=_,ipv4

  Current master:

    qemu-system-x86_64: -netdev type=user,id=_,ipv4: Parameter 'id' expects an identifier
    Identifiers consist of letters, digits, '-', '.', '_', starting with a letter.

  Guessing modern instead:

    qemu-system-x86_64: -netdev type=user,id=_,ipv4: Expected '=' after parameter 'ipv4'

  This should be rare in practice, as traditional parsing detects very
  few errors.

>> Guessing traditional is wrong when the user intends modern.  This
>> happens when a meant-to-be-modern @optarg fails to parse as modern,
>> i.e. whenever the user screws up modern syntax.
>
> This one is the example you gave (ipv4-off)

Two sub-cases then:

* @optarg parses fine as traditional.  The parse result is unlikely to
  make sense, though.  For instance,

    $ qemu-system-x86_64 -netdev type=stream,id=foo,server

  parses with a warning:

    qemu-system-x86_64: -netdev type=stream,id=foo,server: warning: short-form boolean option 'server' deprecated
    Please use server=on instead

  But the result fails in the opts visitor:

    qemu-system-x86_64: -netdev type=stream,id=foo,server: Parameter 'type' is missing

  In this case, we're better off with guessing modern:

    qemu-system-x86_64: -netdev type=stream,id=foo,server: Expected '=' after parameter

* @optarg fails to parse traditional, too.  The error reporting is for
  traditional even though the user intends modern.  Can be misleading.

  This is my ipv4-off example.

Can't win.  Parsers simply don't compose that way.

>> Which guess is less bad?  I'm not sure.  Thoughts?
>
> Perhaps we can simply fail if keyval_parse() fails?
>
> something like:
>
>      args = keyval_parse(optarg, "type", NULL, &error_fatal);
>      type = qdict_get_try_str(args, "type");
>      return !g_strcmp0(type, "stream") || !g_strcmp0(type, "dgram");

This rejects working option arguments that don't also parse as modern,
such as "-netdev type=user,id=foo,ipv4".

Guessing traditional seems to be the least bad solution so far.

Supporting both traditional and modern syntax in an option argument is a
swamp.  Can we bypass it somehow?

-object uses traditional QemuOpts parsing for key=value,..., and modern
parsing for JSON.  Sticking to traditional sidesteps compatibility
issues.  But you have to use JSON for things traditional can't express.

Thoughts?



^ permalink raw reply	[flat|nested] 28+ messages in thread

* Re: [RFC PATCH v3 04/11] qapi: net: add stream and dgram netdevs
  2022-06-22 11:47           ` Markus Armbruster
@ 2022-06-22 16:18             ` Laurent Vivier
  2022-06-23 12:49               ` Markus Armbruster
  0 siblings, 1 reply; 28+ messages in thread
From: Laurent Vivier @ 2022-06-22 16:18 UTC (permalink / raw)
  To: Markus Armbruster
  Cc: qemu-devel, Eric Blake, Dr. David Alan Gilbert, Paolo Bonzini,
	Daniel P. Berrangé,
	Jason Wang, Stefano Brivio

On 22/06/2022 13:47, Markus Armbruster wrote:
> Laurent Vivier <lvivier@redhat.com> writes:
> 
>> On 21/06/2022 10:49, Markus Armbruster wrote:
>>> Laurent Vivier <lvivier@redhat.com> writes:
>>>
>>>> On 20/06/2022 17:21, Markus Armbruster wrote:
>>>>> Laurent Vivier <lvivier@redhat.com> writes:
>>>>>
>>>>>> Copied from socket netdev file and modified to use SocketAddress
>>>>>> to be able to introduce new features like unix socket.
>>>>>>
>>>>>> "udp" and "mcast" are squashed into dgram netdev, multicast is detected
>>>>>> according to the IP address type.
>>>>>> "listen" and "connect" modes are managed by stream netdev. An optional
>>>>>> parameter "server" defines the mode (server by default)
>>>>>>
>>>>>> Signed-off-by: Laurent Vivier <lvivier@redhat.com>
>>>>>> Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
>>>>>> ---
>>>
>>> [...]
>>>
>>>>>> diff --git a/net/net.c b/net/net.c
>>>>>> index c337d3d753fe..440957b272ee 100644
>>>>>> --- a/net/net.c
>>>>>> +++ b/net/net.c
>>>> ...
>>>>>> @@ -1612,7 +1617,19 @@ void net_init_clients(void)
>>>>>>      */
>>>>>>     static bool netdev_is_modern(const char *optarg)
>>>>>>     {
>>>>>> -    return false;
>>>>>> +    QDict *args;
>>>>>> +    const char *type;
>>>>>> +    bool is_modern;
>>>>>> +
>>>>>> +    args = keyval_parse(optarg, "type", NULL, NULL);
>>>>>> +    if (!args) {
>>>>>> +        return false;
>>>>>> +    }
>>>>>> +    type = qdict_get_try_str(args, "type");
>>>>>> +    is_modern = !g_strcmp0(type, "stream") || !g_strcmp0(type, "dgram");
>>>>>> +    qobject_unref(args);
>>>>>> +
>>>>>> +    return is_modern;
>>>>>>     }
>>>>>
>>>>> You could use g_autoptr here:
>>>>>
>>>>>           g_autoptr(QDict) args = NULL;
>>>>>           const char *type;
>>>>>           bool is_modern;
>>>>>
>>>>>           args = keyval_parse(optarg, "type", NULL, NULL);
>>>>>           if (!args) {
>>>>>               return false;
>>>>>           }
>>>>>           type = qdict_get_try_str(args, "type");
>>>>>           return !g_strcmp0(type, "stream") || !g_strcmp0(type, "dgram");
>>>>>
>>>>> Matter of taste; you decide.
>>>>
>>>> Looks good. We already had some series to convert existing code to g_autoptr(), so it
>>>> seems the way to do.
>>>>
>>>>>
>>>>> Now recall how this function is used: it decides whether to parse the
>>>>> modern way (with qobject_input_visitor_new_str()) or the traditional way
>>>>> (with qemu_opts_parse_noisily()).
>>>>>
>>>>> qemu_opts_parse_noisily() parses into a QemuOpts, for later use with the
>>>>> opts visitor.
>>>>>
>>>>> qobject_input_visitor_new_str() supports both dotted keys and JSON.  The
>>>>> former is parsed with keyval_parse(), the latter with
>>>>> qobject_from_json().  It returns the resulting parse tree wrapped in a
>>>>> suitable QAPI input visitor.
>>>>>
>>>>> Issue 1: since we get there only when keyval_parse() succeeds, JSON is
>>>>> unreachable.  Reproducer:
>>>>>
>>>>>        $ qemu-system-x86_64 -netdev '{"id":"foo"}'
>>>>>        upstream-qemu: -netdev {"id":"foo"}: Parameter 'id' is missing
>>>>>
>>>>> This is parsed with qemu_opts_parse_noisily(), resulting in a QemuOpts
>>>>> with a single option 'type' with value '{"id":"foo"}'.  The error
>>>>> message comes from the opts visitor.
>>>>>
>>>>> To fix this, make netdev_is_modern() return true when optarg[0] == '{'.
>>>>> This matches how qobject_input_visitor_new_str() recognizes JSON.
>>>>
>>>> OK
>>>>
>>>>>
>>>>> Issue 2: when keyval_parse() detects an error, we throw it away and fall
>>>>> back to QemuOpts.  This is commonly what we want.  But not always.  For
>>>>> instance:
>>>>>
>>>>>        $ qemu-system-x86_64 -netdev 'type=stream,id=foo,addr.type=inet,addr.host=localhost,addr.port=1234,addr.ipv4-off'
>>>>>
>>>>> Note the typo "ipv4-off" instead of ipv4=off.  The error reporting is crap:
>>>>>
>>>>>        qemu-system-x86_64: -netdev type=stream,id=foo,addr.type=inet,addr.host=localhost,addr.port=1234,addr.ipv4-off: warning: short-form boolean option 'addr.ipv4-off' deprecated
>>>>>        Please use addr.ipv4-off=on instead
>>>>>        qemu-system-x86_64: -netdev type=stream,id=foo,addr.type=inet,addr.host=localhost,addr.port=1234,addr.ipv4-off: Parameter 'type' is missing
>>>>>
>>>>> We get this because netdev_is_modern() guesses wrongly: keyval_parse()
>>>>> fails with the perfectly reasonable error message "Expected '=' after
>>>>> parameter 'addr.ipv4-off'", but netdev_is_modern() ignores the error,
>>>>> and fails.  We fall back to QemuOpts, and confusion ensues.
>>>>>
>>>>> I'm not sure we can do much better with reasonable effort.  If we decide
>>>>> to accept this behavior, it should be documented at least in the source
>>>>> code.
>>>>
>>>> What about using modern syntax by default?
>>>>
>>>>        args = keyval_parse(optarg, "type", NULL, NULL);
>>>>        if (!args) {
>>>>            /* cannot detect the syntax, use new style syntax */
>>>>            return true;
>>>>        }
>>>
>>> As is, netdev_is_modern() has three cases:
>>>
>>> 1. keyval_parse() fails
>>>
>>> 2. keyval_parse() succeeds, but value of @type is not modern
>>>
>>> 3. keyval_parse() succeeds, and value of @type is modern
>>>
>>> In case 3. we're sure, because even if qemu_opts_parse_noisily() also
>>> succeeded, it would result in the same value of @type.
>>>
>>> In case 2, assuming traditional seems reasonable.  The assumption can be
>>> wrong when the user intends modern, but fat-fingers the type=T part.
>>>
>>> In case 1, we know nothing.
>>>
>>> Guessing modern is wrong when the user intends traditional.  This
>>> happens when a meant-to-be-traditional @optarg also parses as modern.
>>> Quite possible.
>>
>> I don't see why keyval_parse() fails in this case. Any example?
> 
> Brain cramp on my part, I'm afraid %-}  Let me start over.
> 
> Guessing modern is wrong when the user intends traditional.  Two
> sub-cases then:
> 
> * @optarg parses fine as traditional.  For instance,
> 
>      $ qemu-system-x86_64 -netdev type=user,id=foo,ipv4
> 
>    parses with a warning:
> 
>      option 'ipv4' deprecated
>      Please use ipv4=on instead
> 
>    This is how current master behaves.
> 
>    Guessing modern makes this fail instead:
> 
>      qemu-system-x86_64: -netdev type=user,id=foo,ipv4: Expected '=' after parameter 'ipv4'
> 
>    Regression.
> 
> * @optarg fails to parse traditional, too.  The error reporting is for
>    modern even though the user intends traditional.  Can be misleading.
>    Example:
> 
>      $ qemu-system-x86_64 -netdev type=user,id=_,ipv4
> 
>    Current master:
> 
>      qemu-system-x86_64: -netdev type=user,id=_,ipv4: Parameter 'id' expects an identifier
>      Identifiers consist of letters, digits, '-', '.', '_', starting with a letter.
> 
>    Guessing modern instead:
> 
>      qemu-system-x86_64: -netdev type=user,id=_,ipv4: Expected '=' after parameter 'ipv4'
> 
>    This should be rare in practice, as traditional parsing detects very
>    few errors.
> 
>>> Guessing traditional is wrong when the user intends modern.  This
>>> happens when a meant-to-be-modern @optarg fails to parse as modern,
>>> i.e. whenever the user screws up modern syntax.
>>
>> This one is the example you gave (ipv4-off)
> 
> Two sub-cases then:
> 
> * @optarg parses fine as traditional.  The parse result is unlikely to
>    make sense, though.  For instance,
> 
>      $ qemu-system-x86_64 -netdev type=stream,id=foo,server
> 
>    parses with a warning:
> 
>      qemu-system-x86_64: -netdev type=stream,id=foo,server: warning: short-form boolean option 'server' deprecated
>      Please use server=on instead
> 
>    But the result fails in the opts visitor:
> 
>      qemu-system-x86_64: -netdev type=stream,id=foo,server: Parameter 'type' is missing
> 
>    In this case, we're better off with guessing modern:
> 
>      qemu-system-x86_64: -netdev type=stream,id=foo,server: Expected '=' after parameter
> 
> * @optarg fails to parse traditional, too.  The error reporting is for
>    traditional even though the user intends modern.  Can be misleading.
> 
>    This is my ipv4-off example.
> 
> Can't win.  Parsers simply don't compose that way.
> 
>>> Which guess is less bad?  I'm not sure.  Thoughts?
>>
>> Perhaps we can simply fail if keyval_parse() fails?
>>
>> something like:
>>
>>       args = keyval_parse(optarg, "type", NULL, &error_fatal);
>>       type = qdict_get_try_str(args, "type");
>>       return !g_strcmp0(type, "stream") || !g_strcmp0(type, "dgram");
> 
> This rejects working option arguments that don't also parse as modern,
> such as "-netdev type=user,id=foo,ipv4".
> 
> Guessing traditional seems to be the least bad solution so far.
> 
> Supporting both traditional and modern syntax in an option argument is a
> swamp.  Can we bypass it somehow?
> 
> -object uses traditional QemuOpts parsing for key=value,..., and modern
> parsing for JSON.  Sticking to traditional sidesteps compatibility
> issues.  But you have to use JSON for things traditional can't express.
> 
> Thoughts?
> 

I don't want to force user to switch to JSON to ease move from "-netdev socket" to 
"-netdev stream" and "-netdev dgram".
But I need to be able to parse SocketAddress to specify unix and inet socket address.

As we want to keep the same behavior on error cases (it's what I understand from your 
analysis), perhaps we can rely on traditional mechanism to detect the type: qemu_opts_parse()?

bool netdev_is_modern(const char *optarg)
{
     QemuOpts *opts;
     bool is_modern;
     const char *type;
     static QemuOptsList dummy_opts = {
         .name = "netdev",
         .implied_opt_name = "type",
         .head = QTAILQ_HEAD_INITIALIZER(dummy_opts.head),
         .desc = { { } },
     };

     if (optarg[0] == '{') {
         return true;
     }

     opts = qemu_opts_parse(&dummy_opts, optarg, true, &error_fatal);
     type = qemu_opt_get(opts, "type");
     is_modern = !g_strcmp0(type, "stream") || !g_strcmp0(type, "dgram");

     qemu_opts_reset(&dummy_opts);

     return is_modern;
}

The errors are directly reported by qemu_opts_parse(..., &error_fatal), and are the ones 
expected in the traditional case.

But the error reported for the modern case are not correct anymore.

I really don't think there is a good solution to our problem.

We must accept an incorrect error report in one of these cases.

To not break existing error report seems to be the way to go (qemu_opt_parse()).

Thanks,
Laurent



^ permalink raw reply	[flat|nested] 28+ messages in thread

* Re: [RFC PATCH v3 04/11] qapi: net: add stream and dgram netdevs
  2022-06-22 16:18             ` Laurent Vivier
@ 2022-06-23 12:49               ` Markus Armbruster
  0 siblings, 0 replies; 28+ messages in thread
From: Markus Armbruster @ 2022-06-23 12:49 UTC (permalink / raw)
  To: Laurent Vivier
  Cc: qemu-devel, Eric Blake, Dr. David Alan Gilbert, Paolo Bonzini,
	Daniel P. Berrangé,
	Jason Wang, Stefano Brivio

Laurent Vivier <lvivier@redhat.com> writes:

> On 22/06/2022 13:47, Markus Armbruster wrote:
>> Laurent Vivier <lvivier@redhat.com> writes:
>> 
>>> On 21/06/2022 10:49, Markus Armbruster wrote:
>>>> Laurent Vivier <lvivier@redhat.com> writes:
>>>>
>>>>> On 20/06/2022 17:21, Markus Armbruster wrote:
>>>>>> Laurent Vivier <lvivier@redhat.com> writes:
>>>>>>
>>>>>>> Copied from socket netdev file and modified to use SocketAddress
>>>>>>> to be able to introduce new features like unix socket.
>>>>>>>
>>>>>>> "udp" and "mcast" are squashed into dgram netdev, multicast is detected
>>>>>>> according to the IP address type.
>>>>>>> "listen" and "connect" modes are managed by stream netdev. An optional
>>>>>>> parameter "server" defines the mode (server by default)
>>>>>>>
>>>>>>> Signed-off-by: Laurent Vivier <lvivier@redhat.com>
>>>>>>> Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
>>>>>>> ---
>>>>
>>>> [...]
>>>>
>>>>>>> diff --git a/net/net.c b/net/net.c
>>>>>>> index c337d3d753fe..440957b272ee 100644
>>>>>>> --- a/net/net.c
>>>>>>> +++ b/net/net.c
>>>>> ...
>>>>>>> @@ -1612,7 +1617,19 @@ void net_init_clients(void)
>>>>>>>      */
>>>>>>>     static bool netdev_is_modern(const char *optarg)
>>>>>>>     {
>>>>>>> -    return false;
>>>>>>> +    QDict *args;
>>>>>>> +    const char *type;
>>>>>>> +    bool is_modern;
>>>>>>> +
>>>>>>> +    args = keyval_parse(optarg, "type", NULL, NULL);
>>>>>>> +    if (!args) {
>>>>>>> +        return false;
>>>>>>> +    }
>>>>>>> +    type = qdict_get_try_str(args, "type");
>>>>>>> +    is_modern = !g_strcmp0(type, "stream") || !g_strcmp0(type, "dgram");
>>>>>>> +    qobject_unref(args);
>>>>>>> +
>>>>>>> +    return is_modern;
>>>>>>>     }
>>>>>>
>>>>>> You could use g_autoptr here:
>>>>>>
>>>>>>           g_autoptr(QDict) args = NULL;
>>>>>>           const char *type;
>>>>>>           bool is_modern;
>>>>>>
>>>>>>           args = keyval_parse(optarg, "type", NULL, NULL);
>>>>>>           if (!args) {
>>>>>>               return false;
>>>>>>           }
>>>>>>           type = qdict_get_try_str(args, "type");
>>>>>>           return !g_strcmp0(type, "stream") || !g_strcmp0(type, "dgram");
>>>>>>
>>>>>> Matter of taste; you decide.
>>>>>
>>>>> Looks good. We already had some series to convert existing code to g_autoptr(), so it
>>>>> seems the way to do.
>>>>>
>>>>>>
>>>>>> Now recall how this function is used: it decides whether to parse the
>>>>>> modern way (with qobject_input_visitor_new_str()) or the traditional way
>>>>>> (with qemu_opts_parse_noisily()).
>>>>>>
>>>>>> qemu_opts_parse_noisily() parses into a QemuOpts, for later use with the
>>>>>> opts visitor.
>>>>>>
>>>>>> qobject_input_visitor_new_str() supports both dotted keys and JSON.  The
>>>>>> former is parsed with keyval_parse(), the latter with
>>>>>> qobject_from_json().  It returns the resulting parse tree wrapped in a
>>>>>> suitable QAPI input visitor.
>>>>>>
>>>>>> Issue 1: since we get there only when keyval_parse() succeeds, JSON is
>>>>>> unreachable.  Reproducer:
>>>>>>
>>>>>>        $ qemu-system-x86_64 -netdev '{"id":"foo"}'
>>>>>>        upstream-qemu: -netdev {"id":"foo"}: Parameter 'id' is missing
>>>>>>
>>>>>> This is parsed with qemu_opts_parse_noisily(), resulting in a QemuOpts
>>>>>> with a single option 'type' with value '{"id":"foo"}'.  The error
>>>>>> message comes from the opts visitor.
>>>>>>
>>>>>> To fix this, make netdev_is_modern() return true when optarg[0] == '{'.
>>>>>> This matches how qobject_input_visitor_new_str() recognizes JSON.
>>>>>
>>>>> OK
>>>>>
>>>>>>
>>>>>> Issue 2: when keyval_parse() detects an error, we throw it away and fall
>>>>>> back to QemuOpts.  This is commonly what we want.  But not always.  For
>>>>>> instance:
>>>>>>
>>>>>>        $ qemu-system-x86_64 -netdev 'type=stream,id=foo,addr.type=inet,addr.host=localhost,addr.port=1234,addr.ipv4-off'
>>>>>>
>>>>>> Note the typo "ipv4-off" instead of ipv4=off.  The error reporting is crap:
>>>>>>
>>>>>>        qemu-system-x86_64: -netdev type=stream,id=foo,addr.type=inet,addr.host=localhost,addr.port=1234,addr.ipv4-off: warning: short-form boolean option 'addr.ipv4-off' deprecated
>>>>>>        Please use addr.ipv4-off=on instead
>>>>>>        qemu-system-x86_64: -netdev type=stream,id=foo,addr.type=inet,addr.host=localhost,addr.port=1234,addr.ipv4-off: Parameter 'type' is missing
>>>>>>
>>>>>> We get this because netdev_is_modern() guesses wrongly: keyval_parse()
>>>>>> fails with the perfectly reasonable error message "Expected '=' after
>>>>>> parameter 'addr.ipv4-off'", but netdev_is_modern() ignores the error,
>>>>>> and fails.  We fall back to QemuOpts, and confusion ensues.
>>>>>>
>>>>>> I'm not sure we can do much better with reasonable effort.  If we decide
>>>>>> to accept this behavior, it should be documented at least in the source
>>>>>> code.
>>>>>
>>>>> What about using modern syntax by default?
>>>>>
>>>>>        args = keyval_parse(optarg, "type", NULL, NULL);
>>>>>        if (!args) {
>>>>>            /* cannot detect the syntax, use new style syntax */
>>>>>            return true;
>>>>>        }
>>>>
>>>> As is, netdev_is_modern() has three cases:
>>>>
>>>> 1. keyval_parse() fails
>>>>
>>>> 2. keyval_parse() succeeds, but value of @type is not modern
>>>>
>>>> 3. keyval_parse() succeeds, and value of @type is modern
>>>>
>>>> In case 3. we're sure, because even if qemu_opts_parse_noisily() also
>>>> succeeded, it would result in the same value of @type.
>>>>
>>>> In case 2, assuming traditional seems reasonable.  The assumption can be
>>>> wrong when the user intends modern, but fat-fingers the type=T part.
>>>>
>>>> In case 1, we know nothing.
>>>>
>>>> Guessing modern is wrong when the user intends traditional.  This
>>>> happens when a meant-to-be-traditional @optarg also parses as modern.
>>>> Quite possible.
>>>
>>> I don't see why keyval_parse() fails in this case. Any example?
>> 
>> Brain cramp on my part, I'm afraid %-}  Let me start over.
>> 
>> Guessing modern is wrong when the user intends traditional.  Two
>> sub-cases then:
>> 
>> * @optarg parses fine as traditional.  For instance,
>> 
>>      $ qemu-system-x86_64 -netdev type=user,id=foo,ipv4
>> 
>>    parses with a warning:
>> 
>>      option 'ipv4' deprecated
>>      Please use ipv4=on instead
>> 
>>    This is how current master behaves.
>> 
>>    Guessing modern makes this fail instead:
>> 
>>      qemu-system-x86_64: -netdev type=user,id=foo,ipv4: Expected '=' after parameter 'ipv4'
>> 
>>    Regression.
>> 
>> * @optarg fails to parse traditional, too.  The error reporting is for
>>    modern even though the user intends traditional.  Can be misleading.
>>    Example:
>> 
>>      $ qemu-system-x86_64 -netdev type=user,id=_,ipv4
>> 
>>    Current master:
>> 
>>      qemu-system-x86_64: -netdev type=user,id=_,ipv4: Parameter 'id' expects an identifier
>>      Identifiers consist of letters, digits, '-', '.', '_', starting with a letter.
>> 
>>    Guessing modern instead:
>> 
>>      qemu-system-x86_64: -netdev type=user,id=_,ipv4: Expected '=' after parameter 'ipv4'
>> 
>>    This should be rare in practice, as traditional parsing detects very
>>    few errors.
>> 
>>>> Guessing traditional is wrong when the user intends modern.  This
>>>> happens when a meant-to-be-modern @optarg fails to parse as modern,
>>>> i.e. whenever the user screws up modern syntax.
>>>
>>> This one is the example you gave (ipv4-off)
>> 
>> Two sub-cases then:
>> 
>> * @optarg parses fine as traditional.  The parse result is unlikely to
>>    make sense, though.  For instance,
>> 
>>      $ qemu-system-x86_64 -netdev type=stream,id=foo,server
>> 
>>    parses with a warning:
>> 
>>      qemu-system-x86_64: -netdev type=stream,id=foo,server: warning: short-form boolean option 'server' deprecated
>>      Please use server=on instead
>> 
>>    But the result fails in the opts visitor:
>> 
>>      qemu-system-x86_64: -netdev type=stream,id=foo,server: Parameter 'type' is missing
>> 
>>    In this case, we're better off with guessing modern:
>> 
>>      qemu-system-x86_64: -netdev type=stream,id=foo,server: Expected '=' after parameter
>> 
>> * @optarg fails to parse traditional, too.  The error reporting is for
>>    traditional even though the user intends modern.  Can be misleading.
>> 
>>    This is my ipv4-off example.
>> 
>> Can't win.  Parsers simply don't compose that way.
>> 
>>>> Which guess is less bad?  I'm not sure.  Thoughts?
>>>
>>> Perhaps we can simply fail if keyval_parse() fails?
>>>
>>> something like:
>>>
>>>       args = keyval_parse(optarg, "type", NULL, &error_fatal);
>>>       type = qdict_get_try_str(args, "type");
>>>       return !g_strcmp0(type, "stream") || !g_strcmp0(type, "dgram");
>> 
>> This rejects working option arguments that don't also parse as modern,
>> such as "-netdev type=user,id=foo,ipv4".
>> 
>> Guessing traditional seems to be the least bad solution so far.
>> 
>> Supporting both traditional and modern syntax in an option argument is a
>> swamp.  Can we bypass it somehow?
>> 
>> -object uses traditional QemuOpts parsing for key=value,..., and modern
>> parsing for JSON.  Sticking to traditional sidesteps compatibility
>> issues.  But you have to use JSON for things traditional can't express.
>> 
>> Thoughts?
>> 
>
> I don't want to force user to switch to JSON to ease move from "-netdev socket" to 
> "-netdev stream" and "-netdev dgram".
> But I need to be able to parse SocketAddress to specify unix and inet socket address.

That's fair.

> As we want to keep the same behavior on error cases (it's what I understand from your 
> analysis),

We must not break working usage.

We may change how erroneous usage fails, but we should try to avoid bad
error reporting.  Common errors are more important here.  Whether they
are in existing or in new options doesn't matter.

>            perhaps we can rely on traditional mechanism to detect the type: qemu_opts_parse()?
>
> bool netdev_is_modern(const char *optarg)
> {
>      QemuOpts *opts;
>      bool is_modern;
>      const char *type;
>      static QemuOptsList dummy_opts = {
>          .name = "netdev",
>          .implied_opt_name = "type",
>          .head = QTAILQ_HEAD_INITIALIZER(dummy_opts.head),
>          .desc = { { } },
>      };
>
>      if (optarg[0] == '{') {
>          return true;
>      }
>
>      opts = qemu_opts_parse(&dummy_opts, optarg, true, &error_fatal);
>      type = qemu_opt_get(opts, "type");
>      is_modern = !g_strcmp0(type, "stream") || !g_strcmp0(type, "dgram");
>
>      qemu_opts_reset(&dummy_opts);
>
>      return is_modern;
> }
>
> The errors are directly reported by qemu_opts_parse(..., &error_fatal), and are the ones 
> expected in the traditional case.
>
> But the error reported for the modern case are not correct anymore.
>
> I really don't think there is a good solution to our problem.
>
> We must accept an incorrect error report in one of these cases.
>
> To not break existing error report seems to be the way to go (qemu_opt_parse()).

I'm not sure about passing &error_fatal to qemu_opts_parse().  Let's
examine the possible errors.

qemu_opts_parse() calls opts_parse().

opts_parse() extracts the value of parameter "id" with opts_parse_id().

It then creates a QemuOpts with qemu_opts_create().  Errors:

* "Invalid parameter 'id'" is impossible since !dummy_opts.merge_lists.

* "Parameter "id" expects an identifier" when value of "id" is not
  wellformed.

* "Duplicate ID 'FOO' for netdev" is impossible since @dummy_opts is
  always empty.

It then parses for real with opts_do_parse().  Errors can only come from
opt_validate():

* "Invalid parameter 'FOO'" is impossible since
  opts_accepts_any(&dummy_opts)

* a bunch from qemu_opt_parse(), all impossible since !dummy_opt.desc.

Conclusion: can only error out when value of "id" is not wellformed.

Detecting this error is counter-productive here, because it masks the
value of "type", which is what we're after.

Better, I think: use opts_do_parse() directly.  Something like

    opts = qemu_opts_create(&dummy_opts, NULL, false, &error_abort);
    qemu_opts_do_parse(opts, optarg, dummy_opts.implied_opt_name,
                       &error_abort);
    type = qemu_opt_get(opts, "type");

Note this cannot fail.  It may be unable to extract the value of type if
the user messes up badly enough.  We then assume traditional syntax.
Least bad option so far, I think.

For once, QemuOpts having basically no syntax checks comes it handy.
I'm surprised.



^ permalink raw reply	[flat|nested] 28+ messages in thread

end of thread, other threads:[~2022-06-23 12:52 UTC | newest]

Thread overview: 28+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-06-20 10:18 [RFC PATCH v3 00/11] qapi: net: add unix socket type support to netdev backend Laurent Vivier
2022-06-20 10:18 ` [RFC PATCH v3 01/11] net: introduce convert_host_port() Laurent Vivier
2022-06-20 10:18 ` [RFC PATCH v3 02/11] net: remove the @errp argument of net_client_inits() Laurent Vivier
2022-06-20 11:39   ` Markus Armbruster
2022-06-20 10:18 ` [RFC PATCH v3 03/11] qapi: net: introduce a way to bypass qemu_opts_parse_noisily() Laurent Vivier
2022-06-20 12:43   ` Markus Armbruster
2022-06-20 13:46     ` Laurent Vivier
2022-06-22  8:00   ` Markus Armbruster
2022-06-20 10:18 ` [RFC PATCH v3 04/11] qapi: net: add stream and dgram netdevs Laurent Vivier
2022-06-20 15:21   ` Markus Armbruster
2022-06-20 17:52     ` Laurent Vivier
2022-06-21  8:49       ` Markus Armbruster
2022-06-21 19:27         ` Laurent Vivier
2022-06-22 11:47           ` Markus Armbruster
2022-06-22 16:18             ` Laurent Vivier
2022-06-23 12:49               ` Markus Armbruster
2022-06-20 10:18 ` [RFC PATCH v3 05/11] net: stream: Don't ignore EINVAL on netdev socket connection Laurent Vivier
2022-06-20 10:18 ` [RFC PATCH v3 06/11] net: stream: add unix socket Laurent Vivier
2022-06-20 10:18 ` [RFC PATCH v3 07/11] net: dgram: make dgram_dst generic Laurent Vivier
2022-06-20 10:18 ` [RFC PATCH v3 08/11] net: dgram: move mcast specific code from net_socket_fd_init_dgram() Laurent Vivier
2022-06-20 10:18 ` [RFC PATCH v3 09/11] net: dgram: add unix socket Laurent Vivier
2022-06-20 10:18 ` [RFC PATCH v3 10/11] qemu-sockets: introduce socket_uri() Laurent Vivier
2022-06-20 10:18 ` [RFC PATCH v3 11/11] net: stream: move to QIO Laurent Vivier
2022-06-20 18:24 ` [RFC PATCH v3 00/11] qapi: net: add unix socket type support to netdev backend Dr. David Alan Gilbert
2022-06-21  9:51   ` Laurent Vivier
2022-06-21 10:31     ` Dr. David Alan Gilbert
2022-06-21 10:54       ` Daniel P. Berrangé
2022-06-21 12:16         ` Dr. David Alan Gilbert

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