1 /*
2 * Copyright 2004 The WebRTC Project Authors. All rights reserved.
3 *
4 * Use of this source code is governed by a BSD-style license
5 * that can be found in the LICENSE file in the root of the source
6 * tree. An additional intellectual property rights grant can be found
7 * in the file PATENTS. All contributing project authors may
8 * be found in the AUTHORS file in the root of the source tree.
9 */
10
11 #include "webrtc/p2p/base/stunserver.h"
12
13 #include "webrtc/base/bytebuffer.h"
14 #include "webrtc/base/logging.h"
15
16 namespace cricket {
17
StunServer(rtc::AsyncUDPSocket * socket)18 StunServer::StunServer(rtc::AsyncUDPSocket* socket) : socket_(socket) {
19 socket_->SignalReadPacket.connect(this, &StunServer::OnPacket);
20 }
21
~StunServer()22 StunServer::~StunServer() {
23 socket_->SignalReadPacket.disconnect(this);
24 }
25
OnPacket(rtc::AsyncPacketSocket * socket,const char * buf,size_t size,const rtc::SocketAddress & remote_addr,const rtc::PacketTime & packet_time)26 void StunServer::OnPacket(
27 rtc::AsyncPacketSocket* socket, const char* buf, size_t size,
28 const rtc::SocketAddress& remote_addr,
29 const rtc::PacketTime& packet_time) {
30 // Parse the STUN message; eat any messages that fail to parse.
31 rtc::ByteBuffer bbuf(buf, size);
32 StunMessage msg;
33 if (!msg.Read(&bbuf)) {
34 return;
35 }
36
37 // TODO: If unknown non-optional (<= 0x7fff) attributes are found, send a
38 // 420 "Unknown Attribute" response.
39
40 // Send the message to the appropriate handler function.
41 switch (msg.type()) {
42 case STUN_BINDING_REQUEST:
43 OnBindingRequest(&msg, remote_addr);
44 break;
45
46 default:
47 SendErrorResponse(msg, remote_addr, 600, "Operation Not Supported");
48 }
49 }
50
OnBindingRequest(StunMessage * msg,const rtc::SocketAddress & remote_addr)51 void StunServer::OnBindingRequest(
52 StunMessage* msg, const rtc::SocketAddress& remote_addr) {
53 StunMessage response;
54 GetStunBindReqponse(msg, remote_addr, &response);
55 SendResponse(response, remote_addr);
56 }
57
SendErrorResponse(const StunMessage & msg,const rtc::SocketAddress & addr,int error_code,const char * error_desc)58 void StunServer::SendErrorResponse(
59 const StunMessage& msg, const rtc::SocketAddress& addr,
60 int error_code, const char* error_desc) {
61 StunMessage err_msg;
62 err_msg.SetType(GetStunErrorResponseType(msg.type()));
63 err_msg.SetTransactionID(msg.transaction_id());
64
65 StunErrorCodeAttribute* err_code = StunAttribute::CreateErrorCode();
66 err_code->SetCode(error_code);
67 err_code->SetReason(error_desc);
68 err_msg.AddAttribute(err_code);
69
70 SendResponse(err_msg, addr);
71 }
72
SendResponse(const StunMessage & msg,const rtc::SocketAddress & addr)73 void StunServer::SendResponse(
74 const StunMessage& msg, const rtc::SocketAddress& addr) {
75 rtc::ByteBuffer buf;
76 msg.Write(&buf);
77 rtc::PacketOptions options;
78 if (socket_->SendTo(buf.Data(), buf.Length(), addr, options) < 0)
79 LOG_ERR(LS_ERROR) << "sendto";
80 }
81
GetStunBindReqponse(StunMessage * request,const rtc::SocketAddress & remote_addr,StunMessage * response) const82 void StunServer::GetStunBindReqponse(StunMessage* request,
83 const rtc::SocketAddress& remote_addr,
84 StunMessage* response) const {
85 response->SetType(STUN_BINDING_RESPONSE);
86 response->SetTransactionID(request->transaction_id());
87
88 // Tell the user the address that we received their request from.
89 StunAddressAttribute* mapped_addr;
90 if (!request->IsLegacy()) {
91 mapped_addr = StunAttribute::CreateAddress(STUN_ATTR_MAPPED_ADDRESS);
92 } else {
93 mapped_addr = StunAttribute::CreateXorAddress(STUN_ATTR_XOR_MAPPED_ADDRESS);
94 }
95 mapped_addr->SetAddress(remote_addr);
96 response->AddAttribute(mapped_addr);
97 }
98
99 } // namespace cricket
100