src/net/socket/socks_client_socket.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "net/socket/socks_client_socket.h"
   6
   7 #include "base/basictypes.h"
   8 #include "base/bind.h"
   9 #include "base/compiler_specific.h"
  10 #include "base/sys_byteorder.h"
  11 #include "net/base/io_buffer.h"
  12 #include "net/base/net_log.h"
  13 #include "net/base/net_util.h"
  14 #include "net/socket/client_socket_handle.h"
  15
  16 namespace net {
  17
  18 // Every SOCKS server requests a user-id from the client. It is optional
  19 // and we send an empty string.
  20 static const char kEmptyUserId[] = "";
  21
  22 // For SOCKS4, the client sends 8 bytes  plus the size of the user-id.
  23 static const unsigned int kWriteHeaderSize = 8;
  24
  25 // For SOCKS4 the server sends 8 bytes for acknowledgement.
  26 static const unsigned int kReadHeaderSize = 8;
  27
  28 // Server Response codes for SOCKS.
  29 static const uint8 kServerResponseOk  = 0x5A;
  30 static const uint8 kServerResponseRejected = 0x5B;
  31 static const uint8 kServerResponseNotReachable = 0x5C;
  32 static const uint8 kServerResponseMismatchedUserId = 0x5D;
  33
  34 static const uint8 kSOCKSVersion4 = 0x04;
  35 static const uint8 kSOCKSStreamRequest = 0x01;
  36
  37 // A struct holding the essential details of the SOCKS4 Server Request.
  38 // The port in the header is stored in network byte order.
  39 struct SOCKS4ServerRequest {
  40   uint8 version;
  41   uint8 command;
  42   uint16 nw_port;
  43   uint8 ip[4];
  44 };
  45 COMPILE_ASSERT(sizeof(SOCKS4ServerRequest) == kWriteHeaderSize,
  46                socks4_server_request_struct_wrong_size);
  47
  48 // A struct holding details of the SOCKS4 Server Response.
  49 struct SOCKS4ServerResponse {
  50   uint8 reserved_null;
  51   uint8 code;
  52   uint16 port;
  53   uint8 ip[4];
  54 };
  55 COMPILE_ASSERT(sizeof(SOCKS4ServerResponse) == kReadHeaderSize,
  56                socks4_server_response_struct_wrong_size);
  57
  58 SOCKSClientSocket::SOCKSClientSocket(
  59     scoped_ptr<ClientSocketHandle> transport_socket,
  60     const HostResolver::RequestInfo& req_info,
  61     RequestPriority priority,
  62     HostResolver* host_resolver)
  63     : transport_(transport_socket.Pass()),
  64       next_state_(STATE_NONE),
  65       completed_handshake_(false),
  66       bytes_sent_(0),
  67       bytes_received_(0),
  68       host_resolver_(host_resolver),
  69       host_request_info_(req_info),
  70       priority_(priority),
  71       net_log_(transport_->socket()->NetLog()) {}
  72
  73 SOCKSClientSocket::~SOCKSClientSocket() {
  74   Disconnect();
  75 }
  76
  77 int SOCKSClientSocket::Connect(const CompletionCallback& callback) {
  78   DCHECK(transport_.get());
  79   DCHECK(transport_->socket());
  80   DCHECK_EQ(STATE_NONE, next_state_);
  81   DCHECK(user_callback_.is_null());
  82
  83   // If already connected, then just return OK.
  84   if (completed_handshake_)
  85     return OK;
  86
  87   next_state_ = STATE_RESOLVE_HOST;
  88
  89   net_log_.BeginEvent(NetLog::TYPE_SOCKS_CONNECT);
  90
  91   int rv = DoLoop(OK);
  92   if (rv == ERR_IO_PENDING) {
  93     user_callback_ = callback;
  94   } else {
  95     net_log_.EndEventWithNetErrorCode(NetLog::TYPE_SOCKS_CONNECT, rv);
  96   }
  97   return rv;
  98 }
  99
 100 void SOCKSClientSocket::Disconnect() {
 101   completed_handshake_ = false;
 102   host_resolver_.Cancel();
 103   transport_->socket()->Disconnect();
 104
 105   // Reset other states to make sure they aren't mistakenly used later.
 106   // These are the states initialized by Connect().
 107   next_state_ = STATE_NONE;
 108   user_callback_.Reset();
 109 }
 110
 111 bool SOCKSClientSocket::IsConnected() const {
 112   return completed_handshake_ && transport_->socket()->IsConnected();
 113 }
 114
 115 bool SOCKSClientSocket::IsConnectedAndIdle() const {
 116   return completed_handshake_ && transport_->socket()->IsConnectedAndIdle();
 117 }
 118
 119 const BoundNetLog& SOCKSClientSocket::NetLog() const {
 120   return net_log_;
 121 }
 122
 123 void SOCKSClientSocket::SetSubresourceSpeculation() {
 124   if (transport_.get() && transport_->socket()) {
 125     transport_->socket()->SetSubresourceSpeculation();
 126   } else {
 127     NOTREACHED();
 128   }
 129 }
 130
 131 void SOCKSClientSocket::SetOmniboxSpeculation() {
 132   if (transport_.get() && transport_->socket()) {
 133     transport_->socket()->SetOmniboxSpeculation();
 134   } else {
 135     NOTREACHED();
 136   }
 137 }
 138
 139 bool SOCKSClientSocket::WasEverUsed() const {
 140   if (transport_.get() && transport_->socket()) {
 141     return transport_->socket()->WasEverUsed();
 142   }
 143   NOTREACHED();
 144   return false;
 145 }
 146
 147 bool SOCKSClientSocket::UsingTCPFastOpen() const {
 148   if (transport_.get() && transport_->socket()) {
 149     return transport_->socket()->UsingTCPFastOpen();
 150   }
 151   NOTREACHED();
 152   return false;
 153 }
 154
 155 bool SOCKSClientSocket::WasNpnNegotiated() const {
 156   if (transport_.get() && transport_->socket()) {
 157     return transport_->socket()->WasNpnNegotiated();
 158   }
 159   NOTREACHED();
 160   return false;
 161 }
 162
 163 NextProto SOCKSClientSocket::GetNegotiatedProtocol() const {
 164   if (transport_.get() && transport_->socket()) {
 165     return transport_->socket()->GetNegotiatedProtocol();
 166   }
 167   NOTREACHED();
 168   return kProtoUnknown;
 169 }
 170
 171 bool SOCKSClientSocket::GetSSLInfo(SSLInfo* ssl_info) {
 172   if (transport_.get() && transport_->socket()) {
 173     return transport_->socket()->GetSSLInfo(ssl_info);
 174   }
 175   NOTREACHED();
 176   return false;
 177
 178 }
 179
 180 // Read is called by the transport layer above to read. This can only be done
 181 // if the SOCKS handshake is complete.
 182 int SOCKSClientSocket::Read(IOBuffer* buf, int buf_len,
 183                             const CompletionCallback& callback) {
 184   DCHECK(completed_handshake_);
 185   DCHECK_EQ(STATE_NONE, next_state_);
 186   DCHECK(user_callback_.is_null());
 187
 188   return transport_->socket()->Read(buf, buf_len, callback);
 189 }
 190
 191 // Write is called by the transport layer. This can only be done if the
 192 // SOCKS handshake is complete.
 193 int SOCKSClientSocket::Write(IOBuffer* buf, int buf_len,
 194                              const CompletionCallback& callback) {
 195   DCHECK(completed_handshake_);
 196   DCHECK_EQ(STATE_NONE, next_state_);
 197   DCHECK(user_callback_.is_null());
 198
 199   return transport_->socket()->Write(buf, buf_len, callback);
 200 }
 201
 202 bool SOCKSClientSocket::SetReceiveBufferSize(int32 size) {
 203   return transport_->socket()->SetReceiveBufferSize(size);
 204 }
 205
 206 bool SOCKSClientSocket::SetSendBufferSize(int32 size) {
 207   return transport_->socket()->SetSendBufferSize(size);
 208 }
 209
 210 void SOCKSClientSocket::DoCallback(int result) {
 211   DCHECK_NE(ERR_IO_PENDING, result);
 212   DCHECK(!user_callback_.is_null());
 213
 214   // Since Run() may result in Read being called,
 215   // clear user_callback_ up front.
 216   CompletionCallback c = user_callback_;
 217   user_callback_.Reset();
 218   DVLOG(1) << "Finished setting up SOCKS handshake";
 219   c.Run(result);
 220 }
 221
 222 void SOCKSClientSocket::OnIOComplete(int result) {
 223   DCHECK_NE(STATE_NONE, next_state_);
 224   int rv = DoLoop(result);
 225   if (rv != ERR_IO_PENDING) {
 226     net_log_.EndEventWithNetErrorCode(NetLog::TYPE_SOCKS_CONNECT, rv);
 227     DoCallback(rv);
 228   }
 229 }
 230
 231 int SOCKSClientSocket::DoLoop(int last_io_result) {
 232   DCHECK_NE(next_state_, STATE_NONE);
 233   int rv = last_io_result;
 234   do {
 235     State state = next_state_;
 236     next_state_ = STATE_NONE;
 237     switch (state) {
 238       case STATE_RESOLVE_HOST:
 239         DCHECK_EQ(OK, rv);
 240         rv = DoResolveHost();
 241         break;
 242       case STATE_RESOLVE_HOST_COMPLETE:
 243         rv = DoResolveHostComplete(rv);
 244         break;
 245       case STATE_HANDSHAKE_WRITE:
 246         DCHECK_EQ(OK, rv);
 247         rv = DoHandshakeWrite();
 248         break;
 249       case STATE_HANDSHAKE_WRITE_COMPLETE:
 250         rv = DoHandshakeWriteComplete(rv);
 251         break;
 252       case STATE_HANDSHAKE_READ:
 253         DCHECK_EQ(OK, rv);
 254         rv = DoHandshakeRead();
 255         break;
 256       case STATE_HANDSHAKE_READ_COMPLETE:
 257         rv = DoHandshakeReadComplete(rv);
 258         break;
 259       default:
 260         NOTREACHED() << "bad state";
 261         rv = ERR_UNEXPECTED;
 262         break;
 263     }
 264   } while (rv != ERR_IO_PENDING && next_state_ != STATE_NONE);
 265   return rv;
 266 }
 267
 268 int SOCKSClientSocket::DoResolveHost() {
 269   next_state_ = STATE_RESOLVE_HOST_COMPLETE;
 270   // SOCKS4 only supports IPv4 addresses, so only try getting the IPv4
 271   // addresses for the target host.
 272   host_request_info_.set_address_family(ADDRESS_FAMILY_IPV4);
 273   return host_resolver_.Resolve(
 274       host_request_info_,
 275       priority_,
 276       &addresses_,
 277       base::Bind(&SOCKSClientSocket::OnIOComplete, base::Unretained(this)),
 278       net_log_);
 279 }
 280
 281 int SOCKSClientSocket::DoResolveHostComplete(int result) {
 282   if (result != OK) {
 283     // Resolving the hostname failed; fail the request rather than automatically
 284     // falling back to SOCKS4a (since it can be confusing to see invalid IP
 285     // addresses being sent to the SOCKS4 server when it doesn't support 4A.)
 286     return result;
 287   }
 288
 289   next_state_ = STATE_HANDSHAKE_WRITE;
 290   return OK;
 291 }
 292
 293 // Builds the buffer that is to be sent to the server.
 294 const std::string SOCKSClientSocket::BuildHandshakeWriteBuffer() const {
 295   SOCKS4ServerRequest request;
 296   request.version = kSOCKSVersion4;
 297   request.command = kSOCKSStreamRequest;
 298   request.nw_port = base::HostToNet16(host_request_info_.port());
 299
 300   DCHECK(!addresses_.empty());
 301   const IPEndPoint& endpoint = addresses_.front();
 302
 303   // We disabled IPv6 results when resolving the hostname, so none of the
 304   // results in the list will be IPv6.
 305   // TODO(eroman): we only ever use the first address in the list. It would be
 306   //               more robust to try all the IP addresses we have before
 307   //               failing the connect attempt.
 308   CHECK_EQ(ADDRESS_FAMILY_IPV4, endpoint.GetFamily());
 309   CHECK_LE(endpoint.address().size(), sizeof(request.ip));
 310   memcpy(&request.ip, &endpoint.address()[0], endpoint.address().size());
 311
 312   DVLOG(1) << "Resolved Host is : " << endpoint.ToStringWithoutPort();
 313
 314   std::string handshake_data(reinterpret_cast<char*>(&request),
 315                              sizeof(request));
 316   handshake_data.append(kEmptyUserId, arraysize(kEmptyUserId));
 317
 318   return handshake_data;
 319 }
 320
 321 // Writes the SOCKS handshake data to the underlying socket connection.
 322 int SOCKSClientSocket::DoHandshakeWrite() {
 323   next_state_ = STATE_HANDSHAKE_WRITE_COMPLETE;
 324
 325   if (buffer_.empty()) {
 326     buffer_ = BuildHandshakeWriteBuffer();
 327     bytes_sent_ = 0;
 328   }
 329
 330   int handshake_buf_len = buffer_.size() - bytes_sent_;
 331   DCHECK_GT(handshake_buf_len, 0);
 332   handshake_buf_ = new IOBuffer(handshake_buf_len);
 333   memcpy(handshake_buf_->data(), &buffer_[bytes_sent_],
 334          handshake_buf_len);
 335   return transport_->socket()->Write(
 336       handshake_buf_.get(),
 337       handshake_buf_len,
 338       base::Bind(&SOCKSClientSocket::OnIOComplete, base::Unretained(this)));
 339 }
 340
 341 int SOCKSClientSocket::DoHandshakeWriteComplete(int result) {
 342   if (result < 0)
 343     return result;
 344
 345   // We ignore the case when result is 0, since the underlying Write
 346   // may return spurious writes while waiting on the socket.
 347
 348   bytes_sent_ += result;
 349   if (bytes_sent_ == buffer_.size()) {
 350     next_state_ = STATE_HANDSHAKE_READ;
 351     buffer_.clear();
 352   } else if (bytes_sent_ < buffer_.size()) {
 353     next_state_ = STATE_HANDSHAKE_WRITE;
 354   } else {
 355     return ERR_UNEXPECTED;
 356   }
 357
 358   return OK;
 359 }
 360
 361 int SOCKSClientSocket::DoHandshakeRead() {
 362   next_state_ = STATE_HANDSHAKE_READ_COMPLETE;
 363
 364   if (buffer_.empty()) {
 365     bytes_received_ = 0;
 366   }
 367
 368   int handshake_buf_len = kReadHeaderSize - bytes_received_;
 369   handshake_buf_ = new IOBuffer(handshake_buf_len);
 370   return transport_->socket()->Read(
 371       handshake_buf_.get(),
 372       handshake_buf_len,
 373       base::Bind(&SOCKSClientSocket::OnIOComplete, base::Unretained(this)));
 374 }
 375
 376 int SOCKSClientSocket::DoHandshakeReadComplete(int result) {
 377   if (result < 0)
 378     return result;
 379
 380   // The underlying socket closed unexpectedly.
 381   if (result == 0)
 382     return ERR_CONNECTION_CLOSED;
 383
 384   if (bytes_received_ + result > kReadHeaderSize) {
 385     // TODO(eroman): Describe failure in NetLog.
 386     return ERR_SOCKS_CONNECTION_FAILED;
 387   }
 388
 389   buffer_.append(handshake_buf_->data(), result);
 390   bytes_received_ += result;
 391   if (bytes_received_ < kReadHeaderSize) {
 392     next_state_ = STATE_HANDSHAKE_READ;
 393     return OK;
 394   }
 395
 396   const SOCKS4ServerResponse* response =
 397       reinterpret_cast<const SOCKS4ServerResponse*>(buffer_.data());
 398
 399   if (response->reserved_null != 0x00) {
 400     LOG(ERROR) << "Unknown response from SOCKS server.";
 401     return ERR_SOCKS_CONNECTION_FAILED;
 402   }
 403
 404   switch (response->code) {
 405     case kServerResponseOk:
 406       completed_handshake_ = true;
 407       return OK;
 408     case kServerResponseRejected:
 409       LOG(ERROR) << "SOCKS request rejected or failed";
 410       return ERR_SOCKS_CONNECTION_FAILED;
 411     case kServerResponseNotReachable:
 412       LOG(ERROR) << "SOCKS request failed because client is not running "
 413                  << "identd (or not reachable from the server)";
 414       return ERR_SOCKS_CONNECTION_HOST_UNREACHABLE;
 415     case kServerResponseMismatchedUserId:
 416       LOG(ERROR) << "SOCKS request failed because client's identd could "
 417                  << "not confirm the user ID string in the request";
 418       return ERR_SOCKS_CONNECTION_FAILED;
 419     default:
 420       LOG(ERROR) << "SOCKS server sent unknown response";
 421       return ERR_SOCKS_CONNECTION_FAILED;
 422   }
 423
 424   // Note: we ignore the last 6 bytes as specified by the SOCKS protocol
 425 }
 426
 427 int SOCKSClientSocket::GetPeerAddress(IPEndPoint* address) const {
 428   return transport_->socket()->GetPeerAddress(address);
 429 }
 430
 431 int SOCKSClientSocket::GetLocalAddress(IPEndPoint* address) const {
 432   return transport_->socket()->GetLocalAddress(address);
 433 }
 434
 435 }  // namespace net