net/local/local_sockif.c:add local_getpeername function implementation

this testcast
TEST_IMPL(udp_send_unix) {
  /* Test that "uv_udp_send()" supports sending over
     a "sockaddr_un" address. */
  struct sockaddr_un addr;
  uv_udp_t handle;
  uv_udp_send_t req;
  uv_loop_t* loop;
  uv_buf_t buf = uv_buf_init("PING", 4);
  int fd;
  int r;

  loop = uv_default_loop();

  memset(&addr, 0, sizeof addr);
  addr.sun_family = AF_UNIX;
  ASSERT(strlen(TEST_PIPENAME) < sizeof(addr.sun_path));
  memcpy(addr.sun_path, TEST_PIPENAME, strlen(TEST_PIPENAME));

  fd = socket(AF_UNIX, SOCK_STREAM, 0);
  ASSERT(fd >= 0);

  unlink(TEST_PIPENAME);
  ASSERT(0 == bind(fd, (const struct sockaddr*)&addr, sizeof addr));
  ASSERT(0 == listen(fd, 1));

  r = uv_udp_init(loop, &handle);
  ASSERT(r == 0);
  r = uv_udp_open(&handle, fd);
  ASSERT(r == 0);
  uv_run(loop, UV_RUN_DEFAULT);

  r = uv_udp_send(&req,
                  &handle,
                  &buf,
                  1,
                  (const struct sockaddr*) &addr,
                  NULL);
  ASSERT(r == 0);

  uv_close((uv_handle_t*)&handle, NULL);
  uv_run(loop, UV_RUN_DEFAULT);
  close(fd);
  unlink(TEST_PIPENAME);

  MAKE_VALGRIND_HAPPY();
  return 0;
}

Signed-off-by: wangchen <wangchen41@xiaomi.com>

net/local/local.h

@@ -122,9 +122,9 @@ struct local_conn_s
   char lc_path[UNIX_PATH_MAX];   /* Path assigned by bind() */
   int32_t lc_instance_id;        /* Connection instance ID for stream
                                   * server<->client connection pair */
-#ifdef CONFIG_NET_LOCAL_SCM
   FAR struct local_conn_s *
                         lc_peer; /* Peer connection instance */
+#ifdef CONFIG_NET_LOCAL_SCM
   uint16_t lc_cfpcount;          /* Control file pointer counter */
   FAR struct file *
      lc_cfps[LOCAL_NCONTROLFDS]; /* Socket message control filep */

net/local/local_accept.c

@@ -169,10 +169,8 @@ int local_accept(FAR struct socket *psock, FAR struct sockaddr *addr,
               conn->lc_type   = LOCAL_TYPE_PATHNAME;
               conn->lc_state  = LOCAL_STATE_CONNECTED;
               conn->lc_psock  = psock;
-#ifdef CONFIG_NET_LOCAL_SCM
               conn->lc_peer   = client;
               client->lc_peer = conn;
-#endif /* CONFIG_NET_LOCAL_SCM */
 
               strlcpy(conn->lc_path, client->lc_path, sizeof(conn->lc_path));
               conn->lc_instance_id = client->lc_instance_id;

net/local/local_conn.c

@@ -168,13 +168,11 @@ void local_free(FAR struct local_conn_s *conn)
   net_lock();
   dq_rem(&conn->lc_conn.node, &g_local_connections);
 
-#ifdef CONFIG_NET_LOCAL_SCM
   if (local_peerconn(conn) && conn->lc_peer)
     {
       conn->lc_peer->lc_peer = NULL;
       conn->lc_peer = NULL;
     }
-#endif /* CONFIG_NET_LOCAL_SCM */
 
   net_unlock();
 

net/local/local_sockif.c

@@ -463,7 +463,82 @@ static int local_getpeername(FAR struct socket *psock,
                              FAR struct sockaddr *addr,
                              FAR socklen_t *addrlen)
 {
-  return local_getsockname(psock, addr, addrlen);
+  FAR struct sockaddr_un *unaddr = (FAR struct sockaddr_un *)addr;
+  FAR struct local_conn_s *conn;
+  FAR struct local_conn_s *peer;
+
+  DEBUGASSERT(psock != NULL && psock->s_conn != NULL &&
+              unaddr != NULL && addrlen != NULL);
+
+  if (*addrlen < sizeof(sa_family_t))
+    {
+      /* This is apparently not an error */
+
+      *addrlen = 0;
+      return OK;
+    }
+
+  /* Verify that the socket has been connected */
+
+  conn = psock->s_conn;
+
+  if (conn->lc_state != LOCAL_STATE_CONNECTED)
+    {
+      return -ENOTCONN;
+    }
+
+  peer = conn->lc_peer;
+
+  /* Save the address family */
+
+  unaddr->sun_family = AF_LOCAL;
+  if (*addrlen > sizeof(sa_family_t))
+    {
+      /* Now copy the address description.  */
+
+      if (peer->lc_type == LOCAL_TYPE_UNNAMED)
+        {
+          /* Zero-length sun_path... This is an abstract Unix domain socket */
+
+          *addrlen = sizeof(sa_family_t);
+        }
+      else /* conn->lc_type = LOCAL_TYPE_PATHNAME */
+        {
+          /* Get the full length of the socket name (incl. null terminator) */
+
+          size_t namelen = strlen(peer->lc_path) + 1 +
+                           (peer->lc_type == LOCAL_TYPE_ABSTRACT);
+
+          /* Get the available length in the user-provided buffer. */
+
+          size_t pathlen = *addrlen - sizeof(sa_family_t);
+
+          /* Clip the socket name size so that if fits in the user buffer */
+
+          if (pathlen < namelen)
+            {
+              namelen = pathlen;
+            }
+
+          /* Copy the path into the user address structure */
+
+          if (peer->lc_type == LOCAL_TYPE_ABSTRACT)
+            {
+              unaddr->sun_path[0] = '\0';
+              strlcpy(&unaddr->sun_path[1],
+                      peer->lc_path, namelen - 1);
+            }
+          else
+            {
+               strlcpy(unaddr->sun_path,
+                      peer->lc_path, namelen);
+            }
+
+          *addrlen = sizeof(sa_family_t) + namelen;
+        }
+    }
+
+  return OK;
 }
 
 #ifdef CONFIG_NET_SOCKOPTS