[RESEND PULL 0/4] Net patches

[RESEND PULL 0/4] Net patches

[Jason Wang]

The following changes since commit e81eb5e6d108008445821e4f891fb9563016c71b:

  Merge remote-tracking branch 'remotes/bonzini-gitlab/tags/for-upstream' into staging (2021-01-23 22:34:21 +0000)

are available in the git repository at:

  https://github.com/jasowang/qemu.git tags/net-pull-request

for you to fetch changes up to f574633529926697ced51b6865e5c50bbb78bf1b:

  net: checksum: Introduce fine control over checksum type (2021-01-25 17:04:56 +0800)

----------------------------------------------------------------

----------------------------------------------------------------
Bin Meng (1):
      net: checksum: Introduce fine control over checksum type

Guishan Qin (1):
      net: checksum: Add IP header checksum calculation

Markus Armbruster (1):
      net: Fix handling of id in netdev_add and netdev_del

Markus Carlstedt (1):
      net: checksum: Skip fragmented IP packets

 hw/net/allwinner-sun8i-emac.c |  2 +-
 hw/net/cadence_gem.c          |  2 +-
 hw/net/fsl_etsec/rings.c      | 18 +++++++++---------
 hw/net/ftgmac100.c            | 13 ++++++++++++-
 hw/net/imx_fec.c              | 20 ++++++++------------
 hw/net/virtio-net.c           |  2 +-
 hw/net/xen_nic.c              |  2 +-
 include/net/checksum.h        |  7 ++++++-
 net/checksum.c                | 24 +++++++++++++++++++++---
 net/filter-rewriter.c         |  4 ++--
 net/net.c                     | 20 ++++++++++++++++++--
 11 files changed, 80 insertions(+), 34 deletions(-)

[RESEND PULL 1/4] net: Fix handling of id in netdev_add and netdev_del

[Jason Wang]

From: Markus Armbruster <armbru@redhat.com>

CLI -netdev accumulates in option group "netdev".

Before commit 08712fcb85 "net: Track netdevs in NetClientState rather
than QemuOpt", netdev_add added to the option group, and netdev_del
removed from it, both HMP and QMP.  Thus, every netdev had a
corresponding QemuOpts in this option group.

Commit 08712fcb85 dropped this for QMP netdev_add and both netdev_del.
Now a netdev has a corresponding QemuOpts only when it was created
with CLI or HMP.  Two issues:

* QMP and HMP netdev_del can leave QemuOpts behind, breaking HMP
  netdev_add.  Reproducer:

    $ qemu-system-x86_64 -S -display none -nodefaults -monitor stdio
    QEMU 5.1.92 monitor - type 'help' for more information
    (qemu) netdev_add user,id=net0
    (qemu) info network
    net0: index=0,type=user,net=10.0.2.0,restrict=off
    (qemu) netdev_del net0
    (qemu) info network
    (qemu) netdev_add user,id=net0
    upstream-qemu: Duplicate ID 'net0' for netdev
    Try "help netdev_add" for more information

  Fix by restoring the QemuOpts deletion in qmp_netdev_del(), but with
  a guard, because the QemuOpts need not exist.

* QMP netdev_add loses its "no duplicate ID" check.  Reproducer:

    $ qemu-system-x86_64 -S -display none -qmp stdio
    {"QMP": {"version": {"qemu": {"micro": 92, "minor": 1, "major": 5}, "package": "v5.2.0-rc2-1-g02c1f0142c"}, "capabilities": ["oob"]}}
    {"execute": "qmp_capabilities"}
    {"return": {}}
    {"execute": "netdev_add", "arguments": {"type": "user", "id":"net0"}}
    {"return": {}}
    {"execute": "netdev_add", "arguments": {"type": "user", "id":"net0"}}
    {"return": {}}

  Fix by adding a duplicate ID check to net_client_init1() to replace
  the lost one.  The check is redundant for callers where QemuOpts
  still checks, i.e. for CLI and HMP.

Reported-by: Andrew Melnichenko <andrew@daynix.com>
Fixes: 08712fcb851034228b61f75bd922863a984a4f60
Cc: qemu-stable@nongnu.org
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 net/net.c | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/net/net.c b/net/net.c
index e1035f2..c1cd9c7 100644
--- a/net/net.c
+++ b/net/net.c
@@ -983,6 +983,7 @@ static int (* const net_client_init_fun[NET_CLIENT_DRIVER__MAX])(
 static int net_client_init1(const Netdev *netdev, bool is_netdev, Error **errp)
 {
     NetClientState *peer = NULL;
+    NetClientState *nc;
 
     if (is_netdev) {
         if (netdev->type == NET_CLIENT_DRIVER_NIC ||
@@ -1010,6 +1011,12 @@ static int net_client_init1(const Netdev *netdev, bool is_netdev, Error **errp)
         }
     }
 
+    nc = qemu_find_netdev(netdev->id);
+    if (nc) {
+        error_setg(errp, "Duplicate ID '%s'", netdev->id);
+        return -1;
+    }
+
     if (net_client_init_fun[netdev->type](netdev, netdev->id, peer, errp) < 0) {
         /* FIXME drop when all init functions store an Error */
         if (errp && !*errp) {
@@ -1020,8 +1027,6 @@ static int net_client_init1(const Netdev *netdev, bool is_netdev, Error **errp)
     }
 
     if (is_netdev) {
-        NetClientState *nc;
-
         nc = qemu_find_netdev(netdev->id);
         assert(nc);
         nc->is_netdev = true;
@@ -1135,6 +1140,7 @@ void qmp_netdev_add(Netdev *netdev, Error **errp)
 void qmp_netdev_del(const char *id, Error **errp)
 {
     NetClientState *nc;
+    QemuOpts *opts;
 
     nc = qemu_find_netdev(id);
     if (!nc) {
@@ -1149,6 +1155,16 @@ void qmp_netdev_del(const char *id, Error **errp)
     }
 
     qemu_del_net_client(nc);
+
+    /*
+     * Wart: we need to delete the QemuOpts associated with netdevs
+     * created via CLI or HMP, to avoid bogus "Duplicate ID" errors in
+     * HMP netdev_add.
+     */
+    opts = qemu_opts_find(qemu_find_opts("netdev"), id);
+    if (opts) {
+        qemu_opts_del(opts);
+    }
 }
 
 static void netfilter_print_info(Monitor *mon, NetFilterState *nf)
-- 
2.7.4

[RESEND PULL 2/4] net: checksum: Skip fragmented IP packets

[Jason Wang]

From: Markus Carlstedt <markus.carlstedt@windriver.com>

To calculate the TCP/UDP checksum we need the whole datagram. Unless
the hardware has some logic to collect all fragments before sending
the whole datagram first, it can only be done by the network stack,
which is normally the case for the NICs we have seen so far.

Skip these fragmented IP packets to avoid checksum corruption.

Signed-off-by: Markus Carlstedt <markus.carlstedt@windriver.com>
Signed-off-by: Bin Meng <bin.meng@windriver.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 net/checksum.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/net/checksum.c b/net/checksum.c
index aaa4000..5cb8b2c 100644
--- a/net/checksum.c
+++ b/net/checksum.c
@@ -106,6 +106,10 @@ void net_checksum_calculate(uint8_t *data, int length)
         return; /* not IPv4 */
     }
 
+    if (IP4_IS_FRAGMENT(ip)) {
+        return; /* a fragmented IP packet */
+    }
+
     ip_len = lduw_be_p(&ip->ip_len);
 
     /* Last, check that we have enough data for the all IP frame */
-- 
2.7.4

[RESEND PULL 3/4] net: checksum: Add IP header checksum calculation

[Jason Wang]

From: Guishan Qin <guishan.qin@windriver.com>

At present net_checksum_calculate() only calculates TCP/UDP checksum
in an IP packet, but assumes the IP header checksum to be provided
by the software, e.g.: Linux kernel always calculates the IP header
checksum. However this might not always be the case, e.g.: for an IP
checksum offload enabled stack like VxWorks, the IP header checksum
can be zero.

This adds the checksum calculation of the IP header.

Signed-off-by: Guishan Qin <guishan.qin@windriver.com>
Signed-off-by: Yabing Liu <yabing.liu@windriver.com>
Signed-off-by: Bin Meng <bin.meng@windriver.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 net/checksum.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/net/checksum.c b/net/checksum.c
index 5cb8b2c..dabd290 100644
--- a/net/checksum.c
+++ b/net/checksum.c
@@ -61,6 +61,7 @@ void net_checksum_calculate(uint8_t *data, int length)
 {
     int mac_hdr_len, ip_len;
     struct ip_header *ip;
+    uint16_t csum;
 
     /*
      * Note: We cannot assume "data" is aligned, so the all code uses
@@ -106,6 +107,11 @@ void net_checksum_calculate(uint8_t *data, int length)
         return; /* not IPv4 */
     }
 
+    /* Calculate IP checksum */
+    stw_he_p(&ip->ip_sum, 0);
+    csum = net_raw_checksum((uint8_t *)ip, IP_HDR_GET_LEN(ip));
+    stw_be_p(&ip->ip_sum, csum);
+
     if (IP4_IS_FRAGMENT(ip)) {
         return; /* a fragmented IP packet */
     }
@@ -122,7 +128,6 @@ void net_checksum_calculate(uint8_t *data, int length)
     switch (ip->ip_p) {
     case IP_PROTO_TCP:
     {
-        uint16_t csum;
         tcp_header *tcp = (tcp_header *)(ip + 1);
 
         if (ip_len < sizeof(tcp_header)) {
@@ -143,7 +148,6 @@ void net_checksum_calculate(uint8_t *data, int length)
     }
     case IP_PROTO_UDP:
     {
-        uint16_t csum;
         udp_header *udp = (udp_header *)(ip + 1);
 
         if (ip_len < sizeof(udp_header)) {
-- 
2.7.4

[RESEND PULL 4/4] net: checksum: Introduce fine control over checksum type

[Jason Wang]

From: Bin Meng <bin.meng@windriver.com>

At present net_checksum_calculate() blindly calculates all types of
checksums (IP, TCP, UDP). Some NICs may have a per type setting in
their BDs to control what checksum should be offloaded. To support
such hardware behavior, introduce a 'csum_flag' parameter to the
net_checksum_calculate() API to allow fine control over what type
checksum is calculated.

Existing users of this API are updated accordingly.

Signed-off-by: Bin Meng <bin.meng@windriver.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 hw/net/allwinner-sun8i-emac.c |  2 +-
 hw/net/cadence_gem.c          |  2 +-
 hw/net/fsl_etsec/rings.c      | 18 +++++++++---------
 hw/net/ftgmac100.c            | 13 ++++++++++++-
 hw/net/imx_fec.c              | 20 ++++++++------------
 hw/net/virtio-net.c           |  2 +-
 hw/net/xen_nic.c              |  2 +-
 include/net/checksum.h        |  7 ++++++-
 net/checksum.c                | 18 ++++++++++++++----
 net/filter-rewriter.c         |  4 ++--
 10 files changed, 55 insertions(+), 33 deletions(-)

diff --git a/hw/net/allwinner-sun8i-emac.c b/hw/net/allwinner-sun8i-emac.c
index 38d3285..0427689 100644
--- a/hw/net/allwinner-sun8i-emac.c
+++ b/hw/net/allwinner-sun8i-emac.c
@@ -514,7 +514,7 @@ static void allwinner_sun8i_emac_transmit(AwSun8iEmacState *s)
         /* After the last descriptor, send the packet */
         if (desc.status2 & TX_DESC_STATUS2_LAST_DESC) {
             if (desc.status2 & TX_DESC_STATUS2_CHECKSUM_MASK) {
-                net_checksum_calculate(packet_buf, packet_bytes);
+                net_checksum_calculate(packet_buf, packet_bytes, CSUM_ALL);
             }
 
             qemu_send_packet(nc, packet_buf, packet_bytes);
diff --git a/hw/net/cadence_gem.c b/hw/net/cadence_gem.c
index 7a53469..9a4474a 100644
--- a/hw/net/cadence_gem.c
+++ b/hw/net/cadence_gem.c
@@ -1266,7 +1266,7 @@ static void gem_transmit(CadenceGEMState *s)
 
                 /* Is checksum offload enabled? */
                 if (s->regs[GEM_DMACFG] & GEM_DMACFG_TXCSUM_OFFL) {
-                    net_checksum_calculate(s->tx_packet, total_bytes);
+                    net_checksum_calculate(s->tx_packet, total_bytes, CSUM_ALL);
                 }
 
                 /* Update MAC statistics */
diff --git a/hw/net/fsl_etsec/rings.c b/hw/net/fsl_etsec/rings.c
index 628648a..121415a 100644
--- a/hw/net/fsl_etsec/rings.c
+++ b/hw/net/fsl_etsec/rings.c
@@ -183,13 +183,11 @@ static void process_tx_fcb(eTSEC *etsec)
     uint8_t *l3_header = etsec->tx_buffer + 8 + l3_header_offset;
     /* L4 header */
     uint8_t *l4_header = l3_header + l4_header_offset;
+    int csum = 0;
 
     /* if packet is IP4 and IP checksum is requested */
     if (flags & FCB_TX_IP && flags & FCB_TX_CIP) {
-        /* do IP4 checksum (TODO This function does TCP/UDP checksum
-         * but not sure if it also does IP4 checksum.) */
-        net_checksum_calculate(etsec->tx_buffer + 8,
-                etsec->tx_buffer_len - 8);
+        csum |= CSUM_IP;
     }
     /* TODO Check the correct usage of the PHCS field of the FCB in case the NPH
      * flag is on */
@@ -201,9 +199,7 @@ static void process_tx_fcb(eTSEC *etsec)
             /* if checksum is requested */
             if (flags & FCB_TX_CTU) {
                 /* do UDP checksum */
-
-                net_checksum_calculate(etsec->tx_buffer + 8,
-                        etsec->tx_buffer_len - 8);
+                csum |= CSUM_UDP;
             } else {
                 /* set checksum field to 0 */
                 l4_header[6] = 0;
@@ -211,10 +207,14 @@ static void process_tx_fcb(eTSEC *etsec)
             }
         } else if (flags & FCB_TX_CTU) { /* if TCP and checksum is requested */
             /* do TCP checksum */
-            net_checksum_calculate(etsec->tx_buffer + 8,
-                                   etsec->tx_buffer_len - 8);
+            csum |= CSUM_TCP;
         }
     }
+
+    if (csum) {
+        net_checksum_calculate(etsec->tx_buffer + 8,
+                               etsec->tx_buffer_len - 8, csum);
+    }
 }
 
 static void process_tx_bd(eTSEC         *etsec,
diff --git a/hw/net/ftgmac100.c b/hw/net/ftgmac100.c
index 782ff19..25685ba 100644
--- a/hw/net/ftgmac100.c
+++ b/hw/net/ftgmac100.c
@@ -564,6 +564,7 @@ static void ftgmac100_do_tx(FTGMAC100State *s, uint32_t tx_ring,
         ptr += len;
         frame_size += len;
         if (bd.des0 & FTGMAC100_TXDES0_LTS) {
+            int csum = 0;
 
             /* Check for VLAN */
             if (flags & FTGMAC100_TXDES1_INS_VLANTAG &&
@@ -573,8 +574,18 @@ static void ftgmac100_do_tx(FTGMAC100State *s, uint32_t tx_ring,
             }
 
             if (flags & FTGMAC100_TXDES1_IP_CHKSUM) {
-                net_checksum_calculate(s->frame, frame_size);
+                csum |= CSUM_IP;
             }
+            if (flags & FTGMAC100_TXDES1_TCP_CHKSUM) {
+                csum |= CSUM_TCP;
+            }
+            if (flags & FTGMAC100_TXDES1_UDP_CHKSUM) {
+                csum |= CSUM_UDP;
+            }
+            if (csum) {
+                net_checksum_calculate(s->frame, frame_size, csum);
+            }
+
             /* Last buffer in frame.  */
             qemu_send_packet(qemu_get_queue(s->nic), s->frame, frame_size);
             ptr = s->frame;
diff --git a/hw/net/imx_fec.c b/hw/net/imx_fec.c
index 2c14804..f03450c 100644
--- a/hw/net/imx_fec.c
+++ b/hw/net/imx_fec.c
@@ -561,22 +561,18 @@ static void imx_enet_do_tx(IMXFECState *s, uint32_t index)
         ptr += len;
         frame_size += len;
         if (bd.flags & ENET_BD_L) {
+            int csum = 0;
+
             if (bd.option & ENET_BD_PINS) {
-                struct ip_header *ip_hd = PKT_GET_IP_HDR(s->frame);
-                if (IP_HEADER_VERSION(ip_hd) == 4) {
-                    net_checksum_calculate(s->frame, frame_size);
-                }
+                csum |= (CSUM_TCP | CSUM_UDP);
             }
             if (bd.option & ENET_BD_IINS) {
-                struct ip_header *ip_hd = PKT_GET_IP_HDR(s->frame);
-                /* We compute checksum only for IPv4 frames */
-                if (IP_HEADER_VERSION(ip_hd) == 4) {
-                    uint16_t csum;
-                    ip_hd->ip_sum = 0;
-                    csum = net_raw_checksum((uint8_t *)ip_hd, sizeof(*ip_hd));
-                    ip_hd->ip_sum = cpu_to_be16(csum);
-                }
+                csum |= CSUM_IP;
+            }
+            if (csum) {
+                net_checksum_calculate(s->frame, frame_size, csum);
             }
+
             /* Last buffer in frame.  */
 
             qemu_send_packet(qemu_get_queue(s->nic), s->frame, frame_size);
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 09ceb02..5150f29 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -1464,7 +1464,7 @@ static void work_around_broken_dhclient(struct virtio_net_hdr *hdr,
         (buf[12] == 0x08 && buf[13] == 0x00) && /* ethertype == IPv4 */
         (buf[23] == 17) && /* ip.protocol == UDP */
         (buf[34] == 0 && buf[35] == 67)) { /* udp.srcport == bootps */
-        net_checksum_calculate(buf, size);
+        net_checksum_calculate(buf, size, CSUM_UDP);
         hdr->flags &= ~VIRTIO_NET_HDR_F_NEEDS_CSUM;
     }
 }
diff --git a/hw/net/xen_nic.c b/hw/net/xen_nic.c
index 00a7fdf..5c815b4 100644
--- a/hw/net/xen_nic.c
+++ b/hw/net/xen_nic.c
@@ -174,7 +174,7 @@ static void net_tx_packets(struct XenNetDev *netdev)
                     tmpbuf = g_malloc(XC_PAGE_SIZE);
                 }
                 memcpy(tmpbuf, page + txreq.offset, txreq.size);
-                net_checksum_calculate(tmpbuf, txreq.size);
+                net_checksum_calculate(tmpbuf, txreq.size, CSUM_ALL);
                 qemu_send_packet(qemu_get_queue(netdev->nic), tmpbuf,
                                  txreq.size);
             } else {
diff --git a/include/net/checksum.h b/include/net/checksum.h
index 05a0d27..7dec37e 100644
--- a/include/net/checksum.h
+++ b/include/net/checksum.h
@@ -21,11 +21,16 @@
 #include "qemu/bswap.h"
 struct iovec;
 
+#define CSUM_IP     0x01
+#define CSUM_TCP    0x02
+#define CSUM_UDP    0x04
+#define CSUM_ALL    (CSUM_IP | CSUM_TCP | CSUM_UDP)
+
 uint32_t net_checksum_add_cont(int len, uint8_t *buf, int seq);
 uint16_t net_checksum_finish(uint32_t sum);
 uint16_t net_checksum_tcpudp(uint16_t length, uint16_t proto,
                              uint8_t *addrs, uint8_t *buf);
-void net_checksum_calculate(uint8_t *data, int length);
+void net_checksum_calculate(uint8_t *data, int length, int csum_flag);
 
 static inline uint32_t
 net_checksum_add(int len, uint8_t *buf)
diff --git a/net/checksum.c b/net/checksum.c
index dabd290..70f4eae 100644
--- a/net/checksum.c
+++ b/net/checksum.c
@@ -57,7 +57,7 @@ uint16_t net_checksum_tcpudp(uint16_t length, uint16_t proto,
     return net_checksum_finish(sum);
 }
 
-void net_checksum_calculate(uint8_t *data, int length)
+void net_checksum_calculate(uint8_t *data, int length, int csum_flag)
 {
     int mac_hdr_len, ip_len;
     struct ip_header *ip;
@@ -108,9 +108,11 @@ void net_checksum_calculate(uint8_t *data, int length)
     }
 
     /* Calculate IP checksum */
-    stw_he_p(&ip->ip_sum, 0);
-    csum = net_raw_checksum((uint8_t *)ip, IP_HDR_GET_LEN(ip));
-    stw_be_p(&ip->ip_sum, csum);
+    if (csum_flag & CSUM_IP) {
+        stw_he_p(&ip->ip_sum, 0);
+        csum = net_raw_checksum((uint8_t *)ip, IP_HDR_GET_LEN(ip));
+        stw_be_p(&ip->ip_sum, csum);
+    }
 
     if (IP4_IS_FRAGMENT(ip)) {
         return; /* a fragmented IP packet */
@@ -128,6 +130,10 @@ void net_checksum_calculate(uint8_t *data, int length)
     switch (ip->ip_p) {
     case IP_PROTO_TCP:
     {
+        if (!(csum_flag & CSUM_TCP)) {
+            return;
+        }
+
         tcp_header *tcp = (tcp_header *)(ip + 1);
 
         if (ip_len < sizeof(tcp_header)) {
@@ -148,6 +154,10 @@ void net_checksum_calculate(uint8_t *data, int length)
     }
     case IP_PROTO_UDP:
     {
+        if (!(csum_flag & CSUM_UDP)) {
+            return;
+        }
+
         udp_header *udp = (udp_header *)(ip + 1);
 
         if (ip_len < sizeof(udp_header)) {
diff --git a/net/filter-rewriter.c b/net/filter-rewriter.c
index fc0e64c..10fe393 100644
--- a/net/filter-rewriter.c
+++ b/net/filter-rewriter.c
@@ -114,7 +114,7 @@ static int handle_primary_tcp_pkt(RewriterState *rf,
             tcp_pkt->th_ack = htonl(ntohl(tcp_pkt->th_ack) + conn->offset);
 
             net_checksum_calculate((uint8_t *)pkt->data + pkt->vnet_hdr_len,
-                                   pkt->size - pkt->vnet_hdr_len);
+                                   pkt->size - pkt->vnet_hdr_len, CSUM_TCP);
         }
 
         /*
@@ -216,7 +216,7 @@ static int handle_secondary_tcp_pkt(RewriterState *rf,
             tcp_pkt->th_seq = htonl(ntohl(tcp_pkt->th_seq) - conn->offset);
 
             net_checksum_calculate((uint8_t *)pkt->data + pkt->vnet_hdr_len,
-                                   pkt->size - pkt->vnet_hdr_len);
+                                   pkt->size - pkt->vnet_hdr_len, CSUM_TCP);
         }
     }
 
-- 
2.7.4

Re: [RESEND PULL 0/4] Net patches

[Peter Maydell]

On Mon, 25 Jan 2021 at 12:23, Jason Wang <jasowang@redhat.com> wrote:
>
> The following changes since commit e81eb5e6d108008445821e4f891fb9563016c71b:
>
>   Merge remote-tracking branch 'remotes/bonzini-gitlab/tags/for-upstream' into staging (2021-01-23 22:34:21 +0000)
>
> are available in the git repository at:
>
>   https://github.com/jasowang/qemu.git tags/net-pull-request
>
> for you to fetch changes up to f574633529926697ced51b6865e5c50bbb78bf1b:
>
>   net: checksum: Introduce fine control over checksum type (2021-01-25 17:04:56 +0800)
>
> ----------------------------------------------------------------
>
> ----------------------------------------------------------------


Applied, thanks.

Please update the changelog at https://wiki.qemu.org/ChangeLog/6.0
for any user-visible changes.

-- PMM