Add remotePort getter to Socket.

runtime/bin/socket_macos.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include <arpa/inet.h>
 #include <errno.h>
 #include <netdb.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ skipping 84 matching lines @@
           getsockname(fd,
                       reinterpret_cast<struct sockaddr *>(&socket_address),
                       &size))) {
     fprintf(stderr, "Error getsockname: %s\n", strerror(errno));
     return 0;
   }
   return ntohs(socket_address.sin_port);
 }
 
 
+intptr_t Socket::GetRemotePort(intptr_t fd) {
+  ASSERT(fd >= 0);
+  struct sockaddr_in socket_address;
+  socklen_t size = sizeof(socket_address);
+  if (TEMP_FAILURE_RETRY(
+          getpeername(fd,
+                      reinterpret_cast<struct sockaddr *>(&socket_address),
+                      &size))) {
+    fprintf(stderr, "Error getpeername: %s\n", strerror(errno));
+    return 0;
+  }
+  return ntohs(socket_address.sin_port);
+}
+
+
 void Socket::GetError(intptr_t fd, OSError* os_error) {
   int len = sizeof(errno);
   getsockopt(fd,
              SOL_SOCKET,
              SO_ERROR,
              &errno,
              reinterpret_cast<socklen_t*>(&len));
   os_error->SetCodeAndMessage(OSError::kSystem, errno);
 }
 
@@ skipping 86 matching lines @@
       // error. We got woken up from the poll on the listening socket,
       // but there is no connection ready to be accepted.
       ASSERT(kTemporaryFailure != -1);
       socket = kTemporaryFailure;
     }
   } else {
     FDUtils::SetNonBlocking(socket);
   }
   return socket;
 }