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

 // 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 139 matching lines @@
     return 0;
 
   PP_NetAddress_IPv4 ipv4;
   PP_NetAddress_IPv6 ipv6;
 
   if (PP_TRUE == NetInterface()->DescribeAsIPv4Address(addr, &ipv4)) {
     sockaddr_in addr4;
     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)) {
     sockaddr_in6 addr6;
     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;
 }
 
 bool SocketNode::IsEquivalentAddress(PP_Resource addr1, PP_Resource addr2) {
   if (addr1 == addr2)
     return true;
 
   char data1[sizeof(sockaddr_in6)];
@@ skipping 288 matching lines @@
     return 0;
   }
 
   *len = ResourceToSockAddr(local_addr_, *len, addr);
   return 0;
 }
 
 }  // namespace nacl_io
 
 #endif  // PROVIDES_SOCKET_API