[NaCl SDK] nacl_io: Add initial support for getsockopt

native_client_sdk/src/libraries/nacl_io/mount_node_socket.cc

Index: native_client_sdk/src/libraries/nacl_io/mount_node_socket.cc
diff --git a/native_client_sdk/src/libraries/nacl_io/mount_node_socket.cc b/native_client_sdk/src/libraries/nacl_io/mount_node_socket.cc
index abaf55ba1e9e48ae0a89fa16d08b65d87ce62962..4aa780947081ba8e330f2a0d3081b767a5a20e56 100644
--- a/native_client_sdk/src/libraries/nacl_io/mount_node_socket.cc
+++ b/native_client_sdk/src/libraries/nacl_io/mount_node_socket.cc
@@ -204,6 +204,18 @@ Error MountNodeSocket::GetSockOpt(int lvl,
                                   int optname,
                                   void* optval,
                                   socklen_t* len) {
+  if (lvl != SOL_SOCKET)
+    return EINVAL;
+
+  switch (optname) {
+    case SO_ERROR:
+      if (*len < sizeof(int))

[binji, 2013/09/30 16:37:48]

http://pubs.opengroup.org/onlinepubs/009695399/functions/getsockopt.html

It says here that the value should be truncated if the size is too small: "If
the size of the option value is greater than option_len, the value stored in the
object pointed to by the option_value argument shall be silently truncated."

[Sam Clegg, 2013/09/30 17:33:25]

Done.

+        return EINVAL;
+      *static_cast<int*>(optval) = 0;

[binji, 2013/09/30 16:37:48]

always 0? This probably needs to be a virtual function so the TCP/UDP socket can
retrieve error if it has one and clear it. Or their error member variables
should move up here.

[Sam Clegg, 2013/09/30 17:33:25]

Done.

+      *len = sizeof(int);
+      return 0;
+  }
+
   return EINVAL;
 }
 
@@ -372,4 +384,4 @@ Error MountNodeSocket::GetSockName(struct sockaddr* addr, socklen_t* len) {
 
 }  // namespace nacl_io
 
-#endif  // PROVIDES_SOCKET_API
+#endif  // PROVIDES_SOCKET_API