nacl_io: only copy up to the size of the sockaddr_in*, not the given len.

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

Index: native_client_sdk/src/libraries/nacl_io/socket/socket_node.cc
diff --git a/native_client_sdk/src/libraries/nacl_io/socket/socket_node.cc b/native_client_sdk/src/libraries/nacl_io/socket/socket_node.cc
index 831345557bd91d5f3ee3e35d3f3715c6f1a3bfc6..1fa78645ce1d5d70afa6c72ff905a3634deba628 100644
--- a/native_client_sdk/src/libraries/nacl_io/socket/socket_node.cc
+++ b/native_client_sdk/src/libraries/nacl_io/socket/socket_node.cc
@@ -157,10 +157,11 @@ socklen_t SocketNode::ResourceToSockAddr(PP_Resource addr,
     addr4.sin_family = AF_INET;
     addr4.sin_port = ipv4.port;
     memcpy(&addr4.sin_addr, ipv4.addr, sizeof(ipv4.addr));
+    len = sizeof(addr4);

[jvoung (off chromium), 2014/06/03 19:24:23]

Hmm, not sure of the point of the len argument then?

[Sam Clegg, 2014/06/03 19:32:43]

I think we should mimik the behavior of getsockname here.

" The returned address is truncated if the buffer provided  is  too  small;  in 
this  case, addrlen will return a value greater than was supplied to the call."

So it sounds like we should always return sizeof(addr6), memcpy
MIN(sizeof(addr6), len) bytes.  We should have tests for this too,
although its not really your responsibility to add them in this
CL I guess.

[binji, 2014/06/03 20:10:05]

+1, the opengroup spec says the same thing.
http://pubs.opengroup.org/onlinepubs/9699919799/functions/getsockname.html

[jvoung (off chromium), 2014/06/03 21:59:32]

Done.

     memcpy(out_addr, &addr4, len);
 
-    // Returns required size not copied size like getpeername/getsockname.
-    return sizeof(sockaddr_in);
+    // Returns required size not like getpeername/getsockname.
+    return len;
   }
 
   if (PP_TRUE == NetInterface()->DescribeAsIPv6Address(addr, &ipv6)) {
@@ -168,10 +169,11 @@ socklen_t SocketNode::ResourceToSockAddr(PP_Resource addr,
     addr6.sin6_family = AF_INET6;
     addr6.sin6_port = ipv6.port;
     memcpy(&addr6.sin6_addr, ipv6.addr, sizeof(ipv6.addr));
+    len = sizeof(addr6);
     memcpy(out_addr, &addr6, len);
 
-    // Returns required size not copied size like getpeername/getsockname.
-    return sizeof(sockaddr_in6);
+    // Returns required size not like getpeername/getsockname.
+    return len;
   }
 
   return 0;