net/udp: Add support for send() with connected UDP sockets

ChangeLog

@@ -10806,4 +10806,7 @@
 	* Networking:  Allow receipt of empty UDP packets.  From Max Neklyudov
 	  (2015-08-11).
 	* drivers/sensors/mb7040.c and include/nuttx/sensors/mb7040.h: Add
-	  support Added MB7040 sonar.  From Paul Alexander Patience (2015-08-07).
+	  support Added MB7040 sonar.  From Paul Alexander Patience (2015-08-11).
+	* net/udp:  Add support for send() for connected UDP sockets
+	  (2015-08-11).
+

TODO

@@ -16,7 +16,7 @@ nuttx/
   (0)  Message Queues (sched/mqueue)
   (4)  C++ Support
   (6)  Binary loaders (binfmt/)
- (13)  Network (net/, drivers/net)
+ (12)  Network (net/, drivers/net)
   (4)  USB (drivers/usbdev, drivers/usbhost)
  (12)  Libraries (libc/, libm/)
  (11)  File system/Generic drivers (fs/, drivers/)
@@ -990,22 +990,6 @@ o Network (net/, drivers/net)
   Priority:    Low.  I don't know of any issues now, but I am sure that
                someone will encounter this in the future.
 
-  Title:       USING send() WITH UDP CONNECTIONS.
-  Description: Currently send is not implemented unless TCP is enabled.  If
-               TCP is enabled and send() is called with a UDP socket, send()
-               will fail with EDESTADDRREQ.  According to OpenGroup.org:
-
-                 "The send() function shall initiate transmission of a message
-                  from the specified socket to its peer. The send() function
-                  shall send a message only when the socket is connected
-                  (including when the peer of a connectionless socket has been
-                  set via connect()).
-
-               This means that, internally, send() should detect the "connected"
-               UDP socket and automatically call sendto().
-  Status:      Open
-  Priority:    Low, there is always the work-around of just calling sendto().
-
 o USB (drivers/usbdev, drivers/usbhost)
   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 

net/socket/Make.defs

@@ -1,7 +1,7 @@
 ############################################################################
 # net/socket/Make.defs
 #
-#   Copyright (C) 2014 Gregory Nutt. All rights reserved.
+#   Copyright (C) 2014-2015 Gregory Nutt. All rights reserved.
 #   Author: Gregory Nutt <gnutt@nuttx.org>
 #
 # Redistribution and use in source and binary forms, with or without
@@ -35,21 +35,19 @@
 
 # Include socket source files
 
-SOCK_CSRCS += bind.c connect.c getsockname.c recv.c recvfrom.c socket.c
+SOCK_CSRCS += bind.c connect.c getsockname.c recv.c recvfrom.c send.c
-SOCK_CSRCS += sendto.c net_sockets.c net_close.c net_dupsd.c net_dupsd2.c
+SOCK_CSRCS += sendto.c socket.c net_sockets.c net_close.c net_dupsd.c
-SOCK_CSRCS += net_clone.c net_poll.c net_vfcntl.c
+SOCK_CSRCS += net_dupsd2.c net_clone.c net_poll.c net_vfcntl.c
 
 # TCP/IP support
 
 ifeq ($(CONFIG_NET_TCP),y)
-SOCK_CSRCS += send.c listen.c accept.c net_monitor.c
+SOCK_CSRCS += listen.c accept.c net_monitor.c
-else
 
 # Local Unix domain support
 
-ifeq ($(CONFIG_NET_LOCAL_STREAM),y)
+else ifeq ($(CONFIG_NET_LOCAL_STREAM),y)
-SOCK_CSRCS += send.c listen.c accept.c
+SOCK_CSRCS += listen.c accept.c
-endif
 endif
 
 # Socket options

net/socket/connect.c

@@ -621,6 +621,14 @@ int psock_connect(FAR struct socket *psock, FAR const struct sockaddr *addr,
 #endif
             {
               ret = udp_connect(psock->s_conn, addr);
+              if (ret < 0 || addr == NULL)
+                {
+                  psock->s_flags &= ~_SF_CONNECTED;
+                }
+              else
+                {
+                  psock->s_flags |= _SF_CONNECTED;
+                }
             }
 #endif /* CONFIG_NET_UDP */
 

net/socket/send.c

@@ -38,13 +38,13 @@
  ****************************************************************************/
 
 #include <nuttx/config.h>
-#if defined(CONFIG_NET_TCP) || defined(CONFIG_NET_LOCAL_STREAM)
 
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <errno.h>
 
 #include "tcp/tcp.h"
+#include "udp/udp.h"
 #include "pkt/pkt.h"
 #include "local/local.h"
 #include "socket/socket.h"
@@ -168,6 +168,31 @@ ssize_t psock_send(FAR struct socket *psock, FAR const void *buf, size_t len,
         break;
 #endif /* CONFIG_NET_TCP || CONFIG_NET_LOCAL_STREAM */
 
+#ifdef CONFIG_NET_UDP
+      case SOCK_DGRAM:
+        {
+#ifdef CONFIG_NET_LOCAL_DGRAM
+#ifdef CONFIG_NET_UDP
+          if (psock->s_domain == PF_LOCAL)
+#endif
+            {
+#warning Missing logic
+              ret = -ENOSYS;
+            }
+#endif /* CONFIG_NET_LOCAL_DGRAM */
+
+#ifdef CONFIG_NET_UDP
+#ifdef CONFIG_NET_LOCAL_DGRAM
+          else
+#endif
+            {
+              ret = psock_udp_send(psock, buf, len);
+            }
+#endif /* CONFIG_NET_UDP */
+        }
+        break;
+#endif /* CONFIG_NET_UDP */
+
       default:
         {
           /* EDESTADDRREQ.  Signifies that the socket is not connection-mode
@@ -250,5 +275,3 @@ ssize_t send(int sockfd, FAR const void *buf, size_t len, int flags)
 {
   return psock_send(sockfd_socket(sockfd), buf, len, flags);
 }
-
-#endif /* CONFIG_NET_TCP || CONFIG_NET_LOCAL_STREAM */

net/socket/sendto.c

@@ -38,7 +38,6 @@
  ****************************************************************************/
 
 #include <nuttx/config.h>
-#ifdef CONFIG_NET
 
 #include <sys/types.h>
 #include <sys/socket.h>
@@ -319,5 +318,3 @@ ssize_t sendto(int sockfd, FAR const void *buf, size_t len, int flags,
 
   return psock_sendto(psock, buf, len, flags, to, tolen);
 }
-
-#endif /* CONFIG_NET */

net/udp/Make.defs

@@ -39,7 +39,7 @@ ifeq ($(CONFIG_NET_UDP),y)
 
 # Socket layer
 
-NET_CSRCS += udp_sendto.c
+NET_CSRCS += udp_psock_send.c udp_psock_sendto.c
 
 ifneq ($(CONFIG_DISABLE_POLL),y)
 ifeq ($(CONFIG_NET_UDP_READAHEAD),y)

net/udp/udp.h

@@ -425,6 +425,17 @@ FAR struct net_driver_s *udp_find_raddr_device(FAR struct udp_conn_s *conn);
 uint16_t udp_callback(FAR struct net_driver_s *dev,
                       FAR struct udp_conn_s *conn, uint16_t flags);
 
+/****************************************************************************
+ * Function: psock_udp_send
+ *
+ * Description:
+ *   Implements send() for connected UDP sockets
+ *
+ ****************************************************************************/
+
+ssize_t psock_udp_send(FAR struct socket *psock, FAR const void *buf,
+                       size_t len);
+
 /****************************************************************************
  * Function: psock_udp_sendto
  *

net/udp/udp_psock_send.c

@@ -0,0 +1,130 @@
+/****************************************************************************
+ * net/udp/udp_send.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>
+
+#include <sys/types.h>
+#include <string.h>
+#include <assert.h>
+#include <errno.h>
+
+#include <nuttx/net/net.h>
+
+#include "socket/socket.h"
+#include "udp/udp.h"
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Function: psock_udp_send
+ *
+ * Description:
+ *   Implements send() for connected UDP sockets
+ *
+ ****************************************************************************/
+
+ssize_t psock_udp_send(FAR struct socket *psock, FAR const void *buf,
+                       size_t len)
+{
+  FAR struct udp_conn_s *conn;
+  union
+  {
+    struct sockaddr     addr;
+#ifdef CONFIG_NET_IPv4
+    struct sockaddr_in  addr4;
+#endif
+#ifdef CONFIG_NET_IPv6
+    struct sockaddr_in6 addr6;
+#endif
+  } to;
+  socklen_t tolen;
+
+  DEBUGASSERT(psock != NULL && psock->s_crefs > 0);
+  DEBUGASSERT(psock->s_type != SOCK_DGRAM);
+
+  conn = (FAR struct udp_conn_s *)psock->s_conn;
+  DEBUGASSERT(conn);
+
+  /* Was the UDP socket connected via connect()? */
+
+  if (!_SS_ISCONNECTED(psock->s_flags))
+    {
+      /* Now, then it is not legal to call send */
+
+      return -ENOTCONN;
+    }
+
+  /* Yes, then let psock_sendto to the work */
+
+#ifdef CONFIG_NET_IPv4
+#ifdef CONFIG_NET_IPv6
+      if (conn->domain == PF_INET)
+#endif
+        {
+          tolen               = sizeof(struct sockaddr_in);
+          to.addr4.sin_family = AF_INET;
+          to.addr4.sin_port   = conn->rport;
+          net_ipv4addr_copy(to.addr4.sin_addr.s_addr, conn->u.ipv4.raddr);
+        }
+#endif /* CONFIG_NET_IPv4 */
+
+#ifdef CONFIG_NET_IPv6
+#ifdef CONFIG_NET_IPv4
+      else
+#endif
+        {
+          tolen               = sizeof(struct sockaddr_in6);
+          to.addr6.sin6_family = AF_INET6;
+          to.addr6.sin6_port   = conn->rport;
+          net_ipv6addr_copy(to.addr6.sin6_addr.s6_addr, conn->u.ipv6.raddr);
+        }
+#endif /* CONFIG_NET_IPv6 */
+
+  return psock_udp_sendto(psock, buf, len, 0, &to.addr, tolen);
+}

net/udp/udp_psock_sendto.c

@@ -1,5 +1,5 @@
 /****************************************************************************
- * net/udp/udp_sendto.c
+ * net/udp/udp_psock_sendto.c
  *
  *   Copyright (C) 2007-2009, 2011-2015 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>