Unix domain: Add sendto logic for SOCK_DRAM protocoal

net/local/local.h

@@ -582,7 +582,7 @@ int local_open_receiver(FAR struct local_conn_s *conn);
  *
  ****************************************************************************/
 
-int local_open_sender(FAR struct local_conn_s *conn);
+int local_open_sender(FAR struct local_conn_s *conn, FAR char *path);
 
 #undef EXTERN
 #ifdef __cplusplus

net/local/local_fifo.c

@@ -79,7 +79,7 @@ static inline void local_cs_name(FAR struct local_conn_s *conn,
 {
   (void)snprintf(path, LOCAL_FULLPATH_LEN-1, "%s" LOCAL_CS_SUFFIX,
                  conn->lc_path);
-   path[LOCAL_FULLPATH_LEN-1] = '\0';
+  path[LOCAL_FULLPATH_LEN-1] = '\0';
 }
 
 /****************************************************************************
@@ -95,7 +95,7 @@ static inline void local_sc_name(FAR struct local_conn_s *conn,
 {
   (void)snprintf(path, LOCAL_FULLPATH_LEN-1, "%s" LOCAL_SC_SUFFIX,
                  conn->lc_path);
-   path[LOCAL_FULLPATH_LEN-1] = '\0';
+  path[LOCAL_FULLPATH_LEN-1] = '\0';
 }
 
 /****************************************************************************
@@ -106,12 +106,10 @@ static inline void local_sc_name(FAR struct local_conn_s *conn,
  *
  ****************************************************************************/
 
-static inline void local_hd_name(FAR struct local_conn_s *conn,
-                                 FAR char *path)
+static inline void local_hd_name(FAR const char *inpath, FAR char *outpath)
 {
-  (void)snprintf(path, LOCAL_FULLPATH_LEN-1, "%s" LOCAL_HD_SUFFIX,
-                 conn->lc_path);
-   path[LOCAL_FULLPATH_LEN-1] = '\0';
+  (void)snprintf(outpath, LOCAL_FULLPATH_LEN-1, "%s" LOCAL_HD_SUFFIX, inpath);
+  outpath[LOCAL_FULLPATH_LEN-1] = '\0';
 }
 
 /****************************************************************************
@@ -328,7 +326,7 @@ int local_create_halfduplex(FAR struct local_conn_s *conn)
 
   /* Create the half duplex FIFO if it does not already exist. */
 
-  local_hd_name(conn, path);
+  local_hd_name(conn->lc_path, path);
   return local_create_fifo(path);
 }
 
@@ -375,7 +373,7 @@ int local_destroy_halfduplex(FAR struct local_conn_s *conn)
 
   /* Destroy the half duplex FIFO if it exists. */
 
-  local_hd_name(conn, path);
+  local_hd_name(conn->lc_path, path);
   return local_destroy_fifo(path);
 }
 
@@ -477,7 +475,7 @@ int local_open_receiver(FAR struct local_conn_s *conn)
 
   /* Get the server-to-client path name */
 
-  local_hd_name(conn, path);
+  local_hd_name(conn->lc_path, path);
 
   /* Then open the file for read-only access */
 
@@ -492,17 +490,17 @@ int local_open_receiver(FAR struct local_conn_s *conn)
  *
  ****************************************************************************/
 
-int local_open_sender(FAR struct local_conn_s *conn)
+int local_open_sender(FAR struct local_conn_s *conn, FAR char *path)
 {
-  char path[LOCAL_FULLPATH_LEN];
+  char fullpath[LOCAL_FULLPATH_LEN];
 
   /* Get the server-to-client path name */
 
-  local_hd_name(conn, path);
+  local_hd_name(path, fullpath);
 
   /* Then open the file for read-only access */
 
-  return local_tx_open(conn, path);
+  return local_tx_open(conn, fullpath);
 }
 
 #endif /* CONFIG_NET && CONFIG_NET_LOCAL */

net/local/local_sendto.c

@@ -42,7 +42,10 @@
 
 #include <sys/types.h>
 #include <sys/socket.h>
+#include <unistd.h>
 #include <errno.h>
+#include <assert.h>
+#include <debug.h>
 
 #include <nuttx/net/net.h>
 
@@ -81,8 +84,76 @@ ssize_t psock_local_sendto(FAR struct socket *psock, FAR const void *buf,
                            size_t len, int flags, FAR const struct sockaddr *to,
                            socklen_t tolen)
 {
-#warning Missing logic
-  return -ENOSYS;
+  FAR struct local_conn_s *conn = (FAR struct local_conn_s *)psock->s_conn;
+  FAR struct sockaddr_un *unaddr = (FAR struct sockaddr_un *)to;
+  ssize_t nsent;
+  int ret;
+
+  /* We keep packet sizes in a uint16_t, so there is a upper limit to the
+   * 'len' that can be supported.
+   */
+
+  DEBUGASSERT(buf && len <= UINT16_MAX);
+
+  /* Verify that this is a bound, un-connected peer socket */
+
+  if (conn->lc_state != LOCAL_STATE_BOUND)
+    {
+      /* Either not bound to address or it is connected */
+
+      ndbg("ERROR: Connected or not bound\n");
+      return -EISCONN;
+    }
+
+  /* The outgoing FIFO should not be open */
+
+  DEBUGASSERT(conn->lc_outfd < 0);
+
+  /* At present, only standard pathname type address are support */
+
+  if (tolen < sizeof(sa_family_t) + 2)
+    {
+     /* EFAULT - An invalid user space address was specified for a parameter */
+
+     return -EFAULT;
+    }
+
+  /* Make sure that half duplex FIFO has been created.
+   * REVISIT:  Or should be just make sure that it already exists?
+   */
+
+  ret = local_create_halfduplex(conn);
+  if (ret < 0)
+    {
+      ndbg("ERROR: Failed to create FIFO for %s: %d\n",
+           conn->lc_path, ret);
+      return ret;
+    }
+
+  /* Open the sending side of the transfer */
+
+  ret = local_open_sender(conn, unaddr->sun_path);
+  if (ret < 0)
+    {
+      ndbg("ERROR: Failed to open FIFO for %s: %d\n",
+           unaddr->sun_path, ret);
+      return ret;
+    }
+
+  /* Send the packet */
+
+  nsent = local_send_packet(conn->lc_outfd, buf, len);
+  if (nsent < 0)
+    {
+      ndbg("ERROR: Failed to send the packet: %d\n", ret);
+    }
+
+  /* Now we can close the write-only socket descriptor */
+
+  close(conn->lc_outfd);
+  conn->lc_outfd = -1;
+
+  return nsent;
 }
 
 #endif /* CONFIG_NET && CONFIG_NET_LOCAL */