Security restrictions for P2P UDP Sockets.

content/browser/renderer_host/p2p_socket_host.cc

 // Copyright (c) 2011 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 "content/browser/renderer_host/p2p_socket_host.h"
 
+#include "build/build_config.h"
+
+#if defined(OS_WIN)
+#include <winsock2.h>  // for htonl
+#else
+#include <arpa/inet.h>
+#endif
+
 #include "content/browser/renderer_host/p2p_socket_host_udp.h"
 
-P2PSocketHost::P2PSocketHost(P2PSocketsHost* host, int routing_id, int id)
-    : host_(host), routing_id_(routing_id), id_(id) {
+namespace {
+const int kStunHeaderSize = 20;
+const uint32 kStunMagicCookie = 0x2112A442;
+}  // namespace
+
+P2PSocketHost::P2PSocketHost(IPC::Message::Sender* message_sender,
+                             int routing_id, int id)
+    : message_sender_(message_sender), routing_id_(routing_id), id_(id) {
 }
 
 P2PSocketHost::~P2PSocketHost() { }
 
+// Verifies that the packet |data| has a valid STUN header.
+bool P2PSocketHost::GetStunPacketType(
+    const char* data, int data_size, StunMessageType* type) {
+
+  if (data_size < kStunHeaderSize)
+    return false;
+
+  // TODO(sergeyu): Fix libjingle to format STUN message according to
+  // RFC5389 and validate STUN magic cookie here.
+  //
+  // uint32 cookie = ntohl(*reinterpret_cast<const uint32*>(data + 4));
+  // if (cookie != kStunMagicCookie)
+  //   return false;
+
+  uint16 length = ntohs(*reinterpret_cast<const uint16*>(data + 2));
+  if (length != data_size - kStunHeaderSize)
+    return false;
+
+  int message_type = ntohs(*reinterpret_cast<const uint16*>(data));
+
+  // Verify that the type is known:
+  switch (message_type) {
+    case STUN_BINDING_REQUEST:
+    case STUN_BINDING_RESPONSE:
+    case STUN_BINDING_ERROR_RESPONSE:
+    case STUN_SHARED_SECRET_REQUEST:
+    case STUN_SHARED_SECRET_RESPONSE:
+    case STUN_SHARED_SECRET_ERROR_RESPONSE:
+    case STUN_ALLOCATE_REQUEST:
+    case STUN_ALLOCATE_RESPONSE:
+    case STUN_ALLOCATE_ERROR_RESPONSE:
+    case STUN_SEND_REQUEST:
+    case STUN_SEND_RESPONSE:
+    case STUN_SEND_ERROR_RESPONSE:
+    case STUN_DATA_INDICATION:
+      *type = static_cast<StunMessageType>(message_type);
+      return true;
+
+    default:
+      return false;
+  }
+}
+
 // static
 P2PSocketHost* P2PSocketHost::Create(
-    P2PSocketsHost* host, int routing_id, int id, P2PSocketType type) {
+    IPC::Message::Sender* message_sender, int routing_id, int id,
+    P2PSocketType type) {
   switch (type) {
     case P2P_SOCKET_UDP:
-      return new P2PSocketHostUdp(host, routing_id, id);
+      return new P2PSocketHostUdp(message_sender, routing_id, id);
 
     case P2P_SOCKET_TCP_SERVER:
       // TODO(sergeyu): Implement TCP sockets support.
+      NOTIMPLEMENTED();
       return NULL;
 
     case P2P_SOCKET_TCP_CLIENT:
+      NOTIMPLEMENTED();
       return NULL;
   }
 
   NOTREACHED();
   return NULL;
 }