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/*
* 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 "talk/base/bytebuffer.h"
#include "talk/p2p/base/stunserver.h"
#include <iostream>
#include <cstring>
#ifdef POSIX
extern "C" {
#include <errno.h>
}
#endif // POSIX
namespace cricket {
StunServer::StunServer(AsyncUDPSocket* socket) : socket_(socket) {
socket_->SignalReadPacket.connect(this, &StunServer::OnPacket);
}
StunServer::~StunServer() {
socket_->SignalReadPacket.disconnect(this);
}
void StunServer::OnPacket(
const char* buf, size_t size, const SocketAddress& remote_addr,
AsyncPacketSocket* socket) {
// TODO: If appropriate, look for the magic cookie before parsing.
// Parse the STUN message.
ByteBuffer bbuf(buf, size);
StunMessage msg;
if (!msg.Read(&bbuf)) {
SendErrorResponse(msg, remote_addr, 400, "Bad Request");
return;
}
// TODO: If this is UDP, then we shouldn't allow non-fully-parsed messages.
// TODO: If unknown non-optiional (<= 0x7fff) attributes are found, send a
// 420 "Unknown Attribute" response.
// TODO: Check that a message-integrity attribute was given (or send 401
// "Unauthorized"). Check that a username attribute was given (or send
// 432 "Missing Username"). Look up the username and password. If it
// is missing or the HMAC is wrong, send 431 "Integrity Check Failure".
// Send the message to the appropriate handler function.
switch (msg.type()) {
case STUN_BINDING_REQUEST:
OnBindingRequest(&msg, remote_addr);
return;
case STUN_ALLOCATE_REQUEST:
OnAllocateRequest(&msg, remote_addr);
return;
default:
SendErrorResponse(msg, remote_addr, 600, "Operation Not Supported");
}
}
void StunServer::OnBindingRequest(
StunMessage* msg, const SocketAddress& remote_addr) {
StunMessage response;
response.SetType(STUN_BINDING_RESPONSE);
response.SetTransactionID(msg->transaction_id());
// Tell the user the address that we received their request from.
StunAddressAttribute* mapped_addr =
StunAttribute::CreateAddress(STUN_ATTR_MAPPED_ADDRESS);
mapped_addr->SetFamily(1);
mapped_addr->SetPort(remote_addr.port());
mapped_addr->SetIP(remote_addr.ip());
response.AddAttribute(mapped_addr);
// Tell the user the address that we are sending the response from.
SocketAddress local_addr = socket_->GetLocalAddress();
StunAddressAttribute* source_addr =
StunAttribute::CreateAddress(STUN_ATTR_SOURCE_ADDRESS);
source_addr->SetFamily(1);
source_addr->SetPort(local_addr.port());
source_addr->SetIP(local_addr.ip());
response.AddAttribute(source_addr);
// TODO: Add username and message-integrity.
// TODO: Add changed-address. (Keep information about three other servers.)
SendResponse(response, remote_addr);
}
void StunServer::OnAllocateRequest(
StunMessage* msg, const SocketAddress& addr) {
SendErrorResponse(*msg, addr, 600, "Operation Not Supported");
}
void StunServer::OnSharedSecretRequest(
StunMessage* msg, const SocketAddress& addr) {
SendErrorResponse(*msg, addr, 600, "Operation Not Supported");
}
void StunServer::OnSendRequest(StunMessage* msg, const SocketAddress& addr) {
SendErrorResponse(*msg, addr, 600, "Operation Not Supported");
}
void StunServer::SendErrorResponse(
const StunMessage& msg, const SocketAddress& addr, int error_code,
const char* error_desc) {
StunMessage err_msg;
err_msg.SetType(GetStunErrorResponseType(msg.type()));
err_msg.SetTransactionID(msg.transaction_id());
StunErrorCodeAttribute* err_code = StunAttribute::CreateErrorCode();
err_code->SetErrorClass(error_code / 100);
err_code->SetNumber(error_code % 100);
err_code->SetReason(error_desc);
err_msg.AddAttribute(err_code);
SendResponse(err_msg, addr);
}
void StunServer::SendResponse(
const StunMessage& msg, const SocketAddress& addr) {
ByteBuffer buf;
msg.Write(&buf);
// TODO: Allow response addr attribute if sent from another stun server.
if (socket_->SendTo(buf.Data(), buf.Length(), addr) < 0)
std::cerr << "sendto: " << std::strerror(errno) << std::endl;
}
} // namespace cricket
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