1 files changed, 211 insertions, 0 deletions
diff --git a/third_party/libjingle/files/talk/base/natserver.cc b/third_party/libjingle/files/talk/base/natserver.cc
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+++ b/third_party/libjingle/files/talk/base/natserver.cc
@@ -0,0 +1,211 @@
+/*
+ * libjingle
+ * Copyright 2004--2005, Google Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without 
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright notice, 
+ *     this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright notice,
+ *     this list of conditions and the following disclaimer in the documentation
+ *     and/or other materials provided with the distribution.
+ *  3. The name of the author may not be used to endorse or promote products 
+ *     derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
+ * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <cassert>
+#include <cstring>
+#include <iostream>
+
+#ifdef POSIX
+extern "C" {
+#include <errno.h>
+}
+#endif // POSIX
+
+#include "talk/base/natserver.h"
+
+namespace talk_base {
+
+RouteCmp::RouteCmp(NAT* nat) : symmetric(nat->IsSymmetric()) {
+}
+  
+size_t RouteCmp::operator()(const SocketAddressPair& r) const {
+  size_t h = r.source().Hash();
+  if (symmetric)
+    h ^= r.destination().Hash();
+  return h;
+}
+
+bool RouteCmp::operator()(
+      const SocketAddressPair& r1, const SocketAddressPair& r2) const {
+  if (r1.source() < r2.source())
+    return true;
+  if (r2.source() < r1.source())
+    return false;
+  if (symmetric && (r1.destination() < r2.destination()))
+    return true;
+  if (symmetric && (r2.destination() < r1.destination()))
+    return false;
+  return false;
+}
+
+AddrCmp::AddrCmp(NAT* nat)
+    : use_ip(nat->FiltersIP()), use_port(nat->FiltersPort()) {
+}
+  
+size_t AddrCmp::operator()(const SocketAddress& a) const {
+  size_t h = 0;
+  if (use_ip)
+    h ^= a.ip();
+  if (use_port)
+    h ^= a.port() | (a.port() << 16);
+  return h;
+}
+
+bool AddrCmp::operator()(
+      const SocketAddress& a1, const SocketAddress& a2) const {
+  if (use_ip && (a1.ip() < a2.ip()))
+    return true;
+  if (use_ip && (a2.ip() < a1.ip()))
+    return false;
+  if (use_port && (a1.port() < a2.port()))
+    return true;
+  if (use_port && (a2.port() < a1.port()))
+    return false;
+  return false;
+}
+
+NATServer::NATServer(
+      NATType type, SocketFactory* internal, const SocketAddress& internal_addr,
+      SocketFactory* external, const SocketAddress& external_ip)
+      : external_(external), external_ip_(external_ip) {
+  nat_ = NAT::Create(type);
+
+  server_socket_ = CreateAsyncUDPSocket(internal);
+  server_socket_->Bind(internal_addr);
+  server_socket_->SignalReadPacket.connect(this, &NATServer::OnInternalPacket);
+
+  int_map_ = new InternalMap(RouteCmp(nat_));
+  ext_map_ = new ExternalMap();
+}
+
+NATServer::~NATServer() {
+  for (InternalMap::iterator iter = int_map_->begin();
+       iter != int_map_->end();
+       iter++)
+    delete iter->second;
+
+  delete nat_;
+  delete server_socket_;
+  delete int_map_;
+  delete ext_map_;
+}
+
+void NATServer::OnInternalPacket(
+    const char* buf, size_t size, const SocketAddress& addr,
+    AsyncPacketSocket* socket) {
+
+  // Read the intended destination from the wire.
+  SocketAddress dest_addr;
+  dest_addr.Read_(buf, size);
+
+  // Find the translation for these addresses (allocating one if necessary).
+  SocketAddressPair route(addr, dest_addr);
+  InternalMap::iterator iter = int_map_->find(route);
+  if (iter == int_map_->end()) {
+    Translate(route);
+    iter = int_map_->find(route);
+  }
+  assert(iter != int_map_->end());
+
+  // Allow the destination to send packets back to the source.
+  iter->second->whitelist->insert(dest_addr);
+
+  // Send the packet to its intended destination.
+  iter->second->socket->SendTo(
+      buf + dest_addr.Size_(), size - dest_addr.Size_(), dest_addr);
+}
+
+void NATServer::OnExternalPacket(
+    const char* buf, size_t size, const SocketAddress& remote_addr,
+    AsyncPacketSocket* socket) {
+
+  SocketAddress local_addr = socket->GetLocalAddress();
+
+  // Find the translation for this addresses.
+  ExternalMap::iterator iter = ext_map_->find(local_addr);
+  assert(iter != ext_map_->end());
+
+  // Allow the NAT to reject this packet.
+  if (Filter(iter->second, remote_addr)) {
+    std::cerr << "Packet from " << remote_addr.ToString()
+              << " was filtered out by the NAT." << std::endl;
+    return;
+  }
+
+  // Forward this packet to the internal address.
+
+  size_t real_size = size + remote_addr.Size_();
+  char*  real_buf  = new char[real_size];
+
+  remote_addr.Write_(real_buf, real_size);
+  std::memcpy(real_buf + remote_addr.Size_(), buf, size);
+
+  server_socket_->SendTo(real_buf, real_size, iter->second->route.source());
+
+  delete[] real_buf;
+}
+
+void NATServer::Translate(const SocketAddressPair& route) {
+  AsyncUDPSocket* socket = CreateAsyncUDPSocket(external_);
+
+  SocketAddress ext_addr = external_ip_;
+  for (int i = 0; i < 65536; i++) {
+    ext_addr.SetPort((route.source().port() + i) % 65536);
+    if (ext_map_->find(ext_addr) == ext_map_->end()) {
+      int result = socket->Bind(ext_addr);
+      if ((result < 0) && (socket->GetError() == EADDRINUSE))
+	 continue;
+      assert(result >= 0); // TODO: do something better
+
+      TransEntry* entry = new TransEntry(route, socket, nat_);
+      (*int_map_)[route] = entry;
+      (*ext_map_)[ext_addr] = entry;
+      socket->SignalReadPacket.connect(this, &NATServer::OnExternalPacket);
+      return;
+    }
+  }
+
+  std::cerr << "Couldn't find a free port!" << std::endl;
+  delete socket;
+  exit(1);
+}
+
+bool NATServer::Filter(TransEntry* entry, const SocketAddress& ext_addr) {
+  return entry->whitelist->find(ext_addr) == entry->whitelist->end();
+}
+
+NATServer::TransEntry::TransEntry(
+    const SocketAddressPair& r, AsyncUDPSocket* s, NAT* nat)
+    : route(r), socket(s) {
+  whitelist = new AddressSet(AddrCmp(nat));
+}
+
+NATServer::TransEntry::~TransEntry() {
+  delete socket;
+}
+
+} // namespace talk_base