[v6,07/14] net: stream: add unix socket

Commit Message

Laurent Vivier July 22, 2022, 6:56 p.m. UTC

Signed-off-by: Laurent Vivier <[e-mail]>
Reviewed-by: Stefano Brivio <[e-mail]>
---
 net/stream.c    | 108 +++++++++++++++++++++++++++++++++++++++++++++---
 qapi/net.json   |   2 +-
 qemu-options.hx |   1 +
 3 files changed, 105 insertions(+), 6 deletions(-)

Patch

diff --git a/net/stream.c b/net/stream.c
index e8afbaca50b6..0f91ff20df61 100644
--- a/net/stream.c
+++ b/net/stream.c
@@ -235,7 +235,7 @@  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;
 
@@ -253,9 +253,27 @@  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,
@@ -295,6 +313,43 @@  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) {
@@ -380,6 +435,49 @@  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));
+            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;
+            }
+        }
+        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) {
@@ -395,7 +493,7 @@  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;
     }
 
diff --git a/qapi/net.json b/qapi/net.json
index a7506a40ff12..518f288758b0 100644
--- a/qapi/net.json
+++ b/qapi/net.json
@@ -583,7 +583,7 @@ 
 #        or connect to (server=false)
 # @server: create server socket (default: true)
 #
-# Only SocketAddress types 'inet' and 'fd' are supported.
+# Only SocketAddress types 'unix', 'inet' and 'fd' are supported.
 #
 # Since: 7.1
 ##
diff --git a/qemu-options.hx b/qemu-options.hx
index 170117e1adf0..827a951a9ef2 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -2727,6 +2727,7 @@  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=h\n"
     "                configure a network backend to connect to another network\n"
     "                using a socket connection in stream mode.\n"