[NaCl SDK] nacl_io: Add support for basic socketpairs.

native_client_sdk/src/libraries/nacl_io/socket/socket_node.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "nacl_io/socket/socket_node.h"
 
 #include "nacl_io/ossocket.h"
 #ifdef PROVIDES_SOCKET_API
 
 #include <errno.h>
@@ skipping 357 matching lines @@
 }
 
 Error SocketNode::RecvFrom(const HandleAttr& attr,
                            void* buf,
                            size_t len,
                            int flags,
                            struct sockaddr* src_addr,
                            socklen_t* addrlen,
                            int* out_len) {
   PP_Resource addr = 0;
+  if (0 == socket_resource_)
+    return EBADF;
   Error err = RecvHelper(attr, buf, len, flags, &addr, out_len);
   if (0 == err && 0 != addr) {
     if (src_addr)
       *addrlen = ResourceToSockAddr(addr, *addrlen, src_addr);
 
     filesystem_->ppapi()->ReleaseResource(addr);
   }
 
   return err;
 }
 
 Error SocketNode::RecvHelper(const HandleAttr& attr,
                              void* buf,
                              size_t len,
                              int flags,
                              PP_Resource* addr,
                              int* out_len) {
-  if (0 == socket_resource_)
-    return EBADF;
-
   if (TestStreamFlags(SSF_RECV_ENDOFSTREAM)) {
     *out_len = 0;
     return 0;
   }
 
   int ms = read_timeout_;
   if ((flags & MSG_DONTWAIT) || !attr.IsBlocking())
     ms = 0;
 
   // TODO(bradnelson) BUG=295177
@@ skipping 14 matching lines @@
   if ((err == 0) && *out_len)
     QueueInput();
   return err;
 }
 
 Error SocketNode::Send(const HandleAttr& attr,
                        const void* buf,
                        size_t len,
                        int flags,
                        int* out_len) {
+  if (0 == socket_resource_)
+    return EBADF;
+
+  if (0 == remote_addr_)
+    return ENOTCONN;
   return SendHelper(attr, buf, len, flags, remote_addr_, out_len);
 }
 
 Error SocketNode::SendTo(const HandleAttr& attr,
                          const void* buf,
                          size_t len,
                          int flags,
                          const struct sockaddr* dest_addr,
                          socklen_t addrlen,
                          int* out_len) {
   if ((NULL == dest_addr) && (0 == remote_addr_))
     return EDESTADDRREQ;
 
   PP_Resource addr = SockAddrToResource(dest_addr, addrlen);
   if (0 == addr)
     return EINVAL;
 
+  if (0 == socket_resource_)
+    return EBADF;
+
   Error err = SendHelper(attr, buf, len, flags, addr, out_len);
   filesystem_->ppapi()->ReleaseResource(addr);
   return err;
 }
 
 Error SocketNode::SendHelper(const HandleAttr& attr,
                              const void* buf,
                              size_t len,
                              int flags,
                              PP_Resource addr,
                              int* out_len) {
-  if (0 == socket_resource_)
-    return EBADF;
-
-  if (0 == addr)
-    return ENOTCONN;
-
   int ms = write_timeout_;
   if ((flags & MSG_DONTWAIT) || !attr.IsBlocking())
     ms = 0;
 
   EventListenerLock wait(GetEventEmitter());
   Error err = wait.WaitOnEvent(POLLOUT, ms);
 
   // Timeout is treated as a would block for sockets.
   if (ETIMEDOUT == err)
     return EWOULDBLOCK;
@@ skipping 44 matching lines @@
     return 0;
   }
 
   *len = ResourceToSockAddr(local_addr_, *len, addr);
   return 0;
 }
 
 }  // namespace nacl_io
 
 #endif  // PROVIDES_SOCKET_API