net: stream: add unix socket

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com> (QAPI schema)
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>

net/stream.c

@@ -235,7 +235,7 @@ static NetStreamState *net_stream_fd_init(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;
 
@@ -253,8 +253,26 @@ static void net_stream_accept(void *opaque)
     s->fd = fd;
     s->nc.link_down = false;
     net_stream_connect(s);
-    qemu_set_info_str(&s->nc, "connection from %s:%d",
+    switch (saddr.ss_family) {
-                      inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
+    case AF_INET: {
+        struct sockaddr_in *saddr_in = (struct sockaddr_in *)&saddr;
+
+        qemu_set_info_str(&s->nc, "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);
+        qemu_set_info_str(&s->nc, "connect from %s", saddr_un.sun_path);
+        break;
+    }
+    default:
+        g_assert_not_reached();
+    }
 }
 
 static int net_stream_server_init(NetClientState *peer,
@@ -294,6 +312,43 @@ static int net_stream_server_init(NetClientState *peer,
         }
         break;
     }
+    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));
+            return -1;
+        }
+
+        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) {
@@ -337,6 +392,7 @@ static int net_stream_client_init(NetClientState *peer,
 {
     NetStreamState *s;
     struct sockaddr_in saddr_in;
+    struct sockaddr_un saddr_un;
     int fd, connected, ret;
 
     switch (addr->type) {
@@ -373,6 +429,45 @@ static int net_stream_client_init(NetClientState *peer,
             }
         }
         break;
+    case SOCKET_ADDRESS_TYPE_UNIX:
+        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));
+            return -1;
+        }
+
+        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;
+            }
+        }
+        break;
     case SOCKET_ADDRESS_TYPE_FD:
         fd = monitor_fd_param(monitor_cur(), addr->u.fd.str, errp);
         if (fd == -1) {
@@ -387,7 +482,7 @@ static int net_stream_client_init(NetClientState *peer,
         connected = 1;
         break;
     default:
-        error_setg(errp, "only support inet or fd type");
+        error_setg(errp, "only support inet, unix or fd type");
         return -1;
     }
 
@@ -399,13 +494,15 @@ static int net_stream_client_init(NetClientState *peer,
                           inet_ntoa(saddr_in.sin_addr),
                           ntohs(saddr_in.sin_port));
         break;
+    case SOCKET_ADDRESS_TYPE_UNIX:
+        qemu_set_info_str(&s->nc, " connect to %s", saddr_un.sun_path);
+        break;
     case SOCKET_ADDRESS_TYPE_FD:
         qemu_set_info_str(&s->nc, "connect to fd %d", fd);
         break;
     default:
         g_assert_not_reached();
     }
-
     return 0;
 }
 

qapi/net.json

@@ -586,7 +586,7 @@
 #        or connect to (server=false)
 # @server: create server socket (default: false)
 #
-# Only SocketAddress types 'inet' and 'fd' are supported.
+# Only SocketAddress types 'unix', 'inet' and 'fd' are supported.
 #
 # Since: 7.2
 ##

qemu-options.hx

@@ -2773,6 +2773,7 @@ DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
     "                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=unix,addr.path=path\n"
     "-netdev stream,id=str[,server=on|off],addr.type=fd,addr.str=file-descriptor\n"
     "                configure a network backend to connect to another network\n"
     "                using a socket connection in stream mode.\n"