Adds a modified copy of talk/base to webrtc/base. It is the first step in
migrating talk/base to webrtc/base.
BUG=N/A
R=niklas.enbom@webrtc.org
Review URL: https://webrtc-codereview.appspot.com/17479005
git-svn-id: http://webrtc.googlecode.com/svn/trunk@6129 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/base/natserver.cc b/webrtc/base/natserver.cc
new file mode 100644
index 0000000..0ce04d7
--- /dev/null
+++ b/webrtc/base/natserver.cc
@@ -0,0 +1,186 @@
+/*
+ * Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ * Use of this source code is governed by a BSD-style license
+ * that can be found in the LICENSE file in the root of the source
+ * tree. An additional intellectual property rights grant can be found
+ * in the file PATENTS. All contributing project authors may
+ * be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/natsocketfactory.h"
+#include "webrtc/base/natserver.h"
+#include "webrtc/base/logging.h"
+
+namespace rtc {
+
+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 ^= HashIP(a.ipaddr());
+ 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.ipaddr() < a2.ipaddr()))
+ return true;
+ if (use_ip && (a2.ipaddr() < a1.ipaddr()))
+ 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.ipaddr(), 0) {
+ nat_ = NAT::Create(type);
+
+ server_socket_ = AsyncUDPSocket::Create(internal, 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(
+ AsyncPacketSocket* socket, const char* buf, size_t size,
+ const SocketAddress& addr, const PacketTime& packet_time) {
+
+ // Read the intended destination from the wire.
+ SocketAddress dest_addr;
+ size_t length = UnpackAddressFromNAT(buf, size, &dest_addr);
+
+ // 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->WhitelistInsert(dest_addr);
+
+ // Send the packet to its intended destination.
+ rtc::PacketOptions options;
+ iter->second->socket->SendTo(buf + length, size - length, dest_addr, options);
+}
+
+void NATServer::OnExternalPacket(
+ AsyncPacketSocket* socket, const char* buf, size_t size,
+ const SocketAddress& remote_addr, const PacketTime& packet_time) {
+
+ 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 (ShouldFilterOut(iter->second, remote_addr)) {
+ LOG(LS_INFO) << "Packet from " << remote_addr.ToSensitiveString()
+ << " was filtered out by the NAT.";
+ return;
+ }
+
+ // Forward this packet to the internal address.
+ // First prepend the address in a quasi-STUN format.
+ scoped_ptr<char[]> real_buf(new char[size + kNATEncodedIPv6AddressSize]);
+ size_t addrlength = PackAddressForNAT(real_buf.get(),
+ size + kNATEncodedIPv6AddressSize,
+ remote_addr);
+ // Copy the data part after the address.
+ rtc::PacketOptions options;
+ memcpy(real_buf.get() + addrlength, buf, size);
+ server_socket_->SendTo(real_buf.get(), size + addrlength,
+ iter->second->route.source(), options);
+}
+
+void NATServer::Translate(const SocketAddressPair& route) {
+ AsyncUDPSocket* socket = AsyncUDPSocket::Create(external_, external_ip_);
+
+ if (!socket) {
+ LOG(LS_ERROR) << "Couldn't find a free port!";
+ return;
+ }
+
+ TransEntry* entry = new TransEntry(route, socket, nat_);
+ (*int_map_)[route] = entry;
+ (*ext_map_)[socket->GetLocalAddress()] = entry;
+ socket->SignalReadPacket.connect(this, &NATServer::OnExternalPacket);
+}
+
+bool NATServer::ShouldFilterOut(TransEntry* entry,
+ const SocketAddress& ext_addr) {
+ return entry->WhitelistContains(ext_addr);
+}
+
+NATServer::TransEntry::TransEntry(
+ const SocketAddressPair& r, AsyncUDPSocket* s, NAT* nat)
+ : route(r), socket(s) {
+ whitelist = new AddressSet(AddrCmp(nat));
+}
+
+NATServer::TransEntry::~TransEntry() {
+ delete whitelist;
+ delete socket;
+}
+
+void NATServer::TransEntry::WhitelistInsert(const SocketAddress& addr) {
+ CritScope cs(&crit_);
+ whitelist->insert(addr);
+}
+
+bool NATServer::TransEntry::WhitelistContains(const SocketAddress& ext_addr) {
+ CritScope cs(&crit_);
+ return whitelist->find(ext_addr) == whitelist->end();
+}
+
+} // namespace rtc