Networking: Add local Unix domain socket accept logic

1 files changed, 202 insertions, 0 deletions

diff --git a/nuttx/net/local/local_accept.c b/nuttx/net/local/local_accept.c
new file mode 100644
index 000000000..e1406168a
--- /dev/null
+++ b/nuttx/net/local/local_accept.c
@@ -0,0 +1,202 @@
+/****************************************************************************
+ * net/local/local_accept.c
+ *
+ *   Copyright (C) 2015 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#if defined(CONFIG_NET) && defined(CONFIG_NET_LOCAL)
+
+#include <string.h>
+#include <errno.h>
+#include <assert.h>
+#include <queue.h>
+
+#include <nuttx/net/net.h>
+
+#include "socket/socket.h"
+#include "local/local.h"
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Function: psock_local_accept
+ *
+ * Description:
+ *   This function implements accept() for Unix domain sockets.  See the
+ *   description of accept() for further information.
+ *
+ * Parameters:
+ *   psock    The listening Unix domain socket structure
+ *   addr     Receives the address of the connecting client
+ *   addrlen  Input: allocated size of 'addr', Return: returned size of 'addr'
+ *   newconn  The new, accepted  Unix domain connection structure
+ *
+ * Returned Value:
+ *   Returns zero (OK) on success or a negated errno value on failure.
+ *   See the description of accept of the possible errno values in the
+ *   description of accept().
+ *
+ * Assumptions:
+ *   Network is NOT locked.
+ *
+ ****************************************************************************/
+
+int psock_local_accept(FAR struct socket *psock, FAR struct sockaddr *addr,
+                       FAR socklen_t *addrlen, FAR void **newconn)
+
+{
+  FAR struct local_conn_s *server;
+  FAR struct local_conn_s *client;
+
+  /* Some sanity checks */
+
+  DEBUGASSERT(psock && psock->s_conn);
+  server = (FAR struct local_conn_s *)psock->s_conn;
+
+  if (server->lc_family != SOCK_STREAM ||
+      server->lc_state != LOCAL_STATE_LISTENING ||
+      server->lc_type != LOCAL_TYPE_PATHNAME)
+    {
+      return -EOPNOTSUPP;
+    }
+
+  /* Are there pending connections.  Remove the client from the
+   * head of the waiting list.
+   */
+
+try_again:
+
+  client = (FAR struct local_conn_s *)
+    dq_remfirst(&server->u.server.lc_waiters);
+
+  if (client)
+    {
+      /* Add the waiting connection to list of clients */
+
+      dq_addlast(&client->lc_node, &server->u.server.lc_conns);
+
+      /* Decrement the number of pending clients */
+
+      DEBUGASSERT(server->u.server.lc_pending > 0);
+      server->u.server.lc_pending--;
+
+      /* And signal the client that the connection was successful */
+
+      client->u.client.lc_result = OK;
+      sem_post(&client->lc_waitsem);
+
+      /* Return the address family */
+
+      if (addr)
+        {
+          FAR struct sockaddr_un *unaddr;
+          int totlen;
+          int pathlen;
+
+          /* If an address is provided, then the length must also be
+           * provided.
+           */
+
+          DEBUGASSERT(addrlen);
+
+          /* Get the length of the path (minus the NUL terminator)
+           * and the length of the whole client address.
+           */
+
+          pathlen = strnlen(client->lc_path, UNIX_PATH_MAX-1);
+          totlen  = sizeof(sa_family_t) + pathlen + 1;
+
+          /* If the length of the whole client address is larger
+           * than the buffer provided by the caller, then truncate
+           * the address to fit.
+           */
+
+          if (totlen > *addrlen)
+            {
+              pathlen    -= (totlen - *addrlen);
+              totlen      = *addrlen;
+            }
+
+          /* Copy the Unix domain address */
+
+          unaddr = (FAR struct sockaddr_un *)addr;
+          unaddr->sun_family = AF_LOCAL;
+          memcpy(unaddr->sun_path, client->lc_path, pathlen);
+          unaddr->sun_path[pathlen] = '\0';
+
+          /* Return the Unix domain address size */
+
+          *addrlen = totlen;
+        }
+
+      /* Return the client connection structure */
+
+      *newconn = (FAR void *)client;
+      return OK;
+    }
+  else
+    {
+      int ret;
+
+      /* No.. then there should be no pending connections */
+
+      DEBUGASSERT(server->u.server.lc_pending == 0);
+
+      /* Was the socket opened non-blocking? */
+
+      if (_SS_ISNONBLOCK(psock->s_flags))
+        {
+          /* Yes.. return EAGAIN */
+
+          return -EAGAIN;
+        }
+
+      /* Otherwise, listen for a connection and try again. */
+
+      ret = local_listen(server, server->u.server.lc_backlog);
+      if (ret < 0)
+        {
+          return ret;
+        }
+
+      goto try_again;
+    }
+}
+
+#endif /* CONFIG_NET && CONFIG_NET_LOCAL */