net: dgram: make dgram_dst generic

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

Rename it dest_addr, and store socket length in dest_len.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>
diff --git a/net/dgram.c b/net/dgram.c
index 5339585..e20be9c 100644
--- a/net/dgram.c
+++ b/net/dgram.c
@@ -40,9 +40,11 @@
     NetClientState nc;
     int fd;
     SocketReadState rs;
-    struct sockaddr_in dgram_dst; /* contains destination iff connectionless */
     bool read_poll;               /* waiting to receive data? */
     bool write_poll;              /* waiting to transmit data? */
+    /* contains destination iff connectionless */
+    struct sockaddr *dest_addr;
+    socklen_t dest_len;
 } NetDgramState;
 
 static void net_dgram_send(void *opaque);
@@ -84,10 +86,8 @@
     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->dest_addr) {
+            ret = sendto(s->fd, buf, size, 0, s->dest_addr, s->dest_len);
         } else {
             ret = send(s->fd, buf, size, 0);
         }
@@ -244,6 +244,9 @@
         close(s->fd);
         s->fd = -1;
     }
+    g_free(s->dest_addr);
+    s->dest_addr = NULL;
+    s->dest_len = 0;
 }
 
 static NetClientInfo net_dgram_socket_info = {
@@ -260,7 +263,7 @@
                                         SocketAddress *mcast,
                                         Error **errp)
 {
-    struct sockaddr_in saddr;
+    struct sockaddr_in *saddr = NULL;
     int newfd;
     NetClientState *nc;
     NetDgramState *s;
@@ -275,31 +278,32 @@
     qapi_free_SocketAddress(sa);
 
     /*
-     * fd passed: multicast: "learn" dgram_dst address from bound address and
+     * fd passed: multicast: "learn" dest_addr 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) {
+            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);
@@ -311,21 +315,20 @@
     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->dest_addr == NULL);
+        s->dest_addr = (struct sockaddr *)saddr;
+        s->dest_len = sizeof(*saddr);
         qemu_set_info_str(nc, "fd=%d (cloned mcast=%s:%d)", fd,
-                          inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
+                          inet_ntoa(saddr->sin_addr), ntohs(saddr->sin_port));
     } else {
-        if (sa_type == SOCKET_ADDRESS_TYPE_UNIX) {
-            s->dgram_dst.sin_family = AF_UNIX;
-        }
-
         qemu_set_info_str(nc, "fd=%d %s", fd, SocketAddressType_str(sa_type));
     }
 
     return s;
 
 err:
+    g_free(saddr);
     closesocket(fd);
     return NULL;
 }
@@ -339,21 +342,24 @@
 {
     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 {
@@ -362,13 +368,15 @@
             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;
@@ -376,16 +384,19 @@
         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;
         }
@@ -395,13 +406,17 @@
                           local->type == SOCKET_ADDRESS_TYPE_FD,
                           remote, errp);
     if (!s) {
+        g_free(saddr);
         return -1;
     }
 
-    s->dgram_dst = saddr;
+    g_assert(s->dest_addr == NULL);
+    s->dest_addr = (struct sockaddr *)saddr;
+    s->dest_len = sizeof(*saddr);
 
-    qemu_set_info_str(&s->nc, "mcast=%s:%d", inet_ntoa(saddr.sin_addr),
-                      ntohs(saddr.sin_port));
+    qemu_set_info_str(&s->nc, "mcast=%s:%d", inet_ntoa(saddr->sin_addr),
+                      ntohs(saddr->sin_port));
+
     return 0;
 
 }
@@ -412,9 +427,10 @@
 {
     NetDgramState *s;
     int fd, ret;
-    struct sockaddr_in raddr_in;
-    struct sockaddr_in laddr_in;
     SocketAddress *remote, *local;
+    struct sockaddr *dest_addr;
+    struct sockaddr_in laddr_in, raddr_in;
+    socklen_t dest_len;
 
     assert(netdev->type == NET_CLIENT_DRIVER_DGRAM);
 
@@ -491,6 +507,10 @@
             return -1;
         }
         qemu_socket_set_nonblock(fd);
+
+        dest_len = sizeof(raddr_in);
+        dest_addr = g_malloc(dest_len);
+        memcpy(dest_addr, &raddr_in, dest_len);
         break;
     case SOCKET_ADDRESS_TYPE_FD:
         fd = monitor_fd_param(monitor_cur(), local->u.fd.str, errp);
@@ -503,6 +523,8 @@
                              name, fd);
             return -1;
         }
+        dest_addr = NULL;
+        dest_len = 0;
         break;
     default:
         error_setg(errp, "only support inet or fd type for local");
@@ -515,7 +537,9 @@
     }
 
     if (remote) {
-        s->dgram_dst = raddr_in;
+        g_assert(s->dest_addr == NULL);
+        s->dest_addr = dest_addr;
+        s->dest_len = dest_len;
     }
 
     switch (local->type) {