[RFC PATCH v3 08/11] net: dgram: move mcast specific code from net_socket_fd_init_dgram()

[Laurent Vivier <lvivier@redhat.com>]

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