SOCKS v5 implementation

The implementation is incomplete as it does not support any authentication methods and does not have a UDP layer.

BUG=469
TEST=unittests (included)

Review URL: http://codereview.chromium.org/150187

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@20626 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 430 insertions, 0 deletions

diff --git a/net/socket/socks5_client_socket.cc b/net/socket/socks5_client_socket.cc
new file mode 100644
index 0000000..8876bb9
--- /dev/null
+++ b/net/socket/socks5_client_socket.cc
@@ -0,0 +1,430 @@
+// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "net/socket/socks5_client_socket.h"
+
+#include "base/basictypes.h"
+#include "build/build_config.h"
+#if defined(OS_WIN)
+#include <ws2tcpip.h>
+#elif defined(OS_POSIX)
+#include <netdb.h>
+#endif
+#include "base/compiler_specific.h"
+#include "base/trace_event.h"
+#include "net/base/io_buffer.h"
+#include "net/base/net_util.h"
+
+namespace net {
+
+const unsigned int SOCKS5ClientSocket::kGreetReadHeaderSize = 2;
+const unsigned int SOCKS5ClientSocket::kWriteHeaderSize = 10;
+const unsigned int SOCKS5ClientSocket::kReadHeaderSize = 5;
+const uint8 SOCKS5ClientSocket::kSOCKS5Version = 0x05;
+const uint8 SOCKS5ClientSocket::kTunnelCommand = 0x01;
+const uint8 SOCKS5ClientSocket::kNullByte = 0x00;
+
+COMPILE_ASSERT(sizeof(struct in_addr) == 4, incorrect_system_size_of_IPv4);
+COMPILE_ASSERT(sizeof(struct in6_addr) == 16, incorrect_system_size_of_IPv6);
+
+SOCKS5ClientSocket::SOCKS5ClientSocket(ClientSocket* transport_socket,
+    const HostResolver::RequestInfo& req_info,
+    HostResolver* host_resolver)
+    : ALLOW_THIS_IN_INITIALIZER_LIST(
+          io_callback_(this, &SOCKS5ClientSocket::OnIOComplete)),
+      transport_(transport_socket),
+      next_state_(STATE_NONE),
+      address_type_(kEndPointUnresolved),
+      user_callback_(NULL),
+      completed_handshake_(false),
+      bytes_sent_(0),
+      bytes_received_(0),
+      read_header_size(kReadHeaderSize),
+      host_resolver_(host_resolver),
+      host_request_info_(req_info) {
+}
+
+SOCKS5ClientSocket::~SOCKS5ClientSocket() {
+  Disconnect();
+}
+
+int SOCKS5ClientSocket::Connect(CompletionCallback* callback) {
+  DCHECK(transport_.get());
+  DCHECK(transport_->IsConnected());
+  DCHECK_EQ(STATE_NONE, next_state_);
+  DCHECK(!user_callback_);
+
+  // If already connected, then just return OK.
+  if (completed_handshake_)
+    return OK;
+
+  next_state_ = STATE_RESOLVE_HOST;
+
+  int rv = DoLoop(OK);
+  if (rv == ERR_IO_PENDING)
+    user_callback_ = callback;
+  return rv;
+}
+
+void SOCKS5ClientSocket::Disconnect() {
+  completed_handshake_ = false;
+  transport_->Disconnect();
+}
+
+bool SOCKS5ClientSocket::IsConnected() const {
+  return completed_handshake_ && transport_->IsConnected();
+}
+
+bool SOCKS5ClientSocket::IsConnectedAndIdle() const {
+  return completed_handshake_ && transport_->IsConnectedAndIdle();
+}
+
+// Read is called by the transport layer above to read. This can only be done
+// if the SOCKS handshake is complete.
+int SOCKS5ClientSocket::Read(IOBuffer* buf, int buf_len,
+                            CompletionCallback* callback) {
+  DCHECK(completed_handshake_);
+  DCHECK_EQ(STATE_NONE, next_state_);
+  DCHECK(!user_callback_);
+
+  return transport_->Read(buf, buf_len, callback);
+}
+
+// Write is called by the transport layer. This can only be done if the
+// SOCKS handshake is complete.
+int SOCKS5ClientSocket::Write(IOBuffer* buf, int buf_len,
+                             CompletionCallback* callback) {
+  DCHECK(completed_handshake_);
+  DCHECK_EQ(STATE_NONE, next_state_);
+  DCHECK(!user_callback_);
+
+  return transport_->Write(buf, buf_len, callback);
+}
+
+void SOCKS5ClientSocket::DoCallback(int result) {
+  DCHECK_NE(ERR_IO_PENDING, result);
+  DCHECK(user_callback_);
+
+  // Since Run() may result in Read being called,
+  // clear user_callback_ up front.
+  CompletionCallback* c = user_callback_;
+  user_callback_ = NULL;
+  DLOG(INFO) << "Finished setting up SOCKSv5 handshake";
+  c->Run(result);
+}
+
+void SOCKS5ClientSocket::OnIOComplete(int result) {
+  DCHECK_NE(STATE_NONE, next_state_);
+  int rv = DoLoop(result);
+  if (rv != ERR_IO_PENDING)
+    DoCallback(rv);
+}
+
+int SOCKS5ClientSocket::DoLoop(int last_io_result) {
+  DCHECK_NE(next_state_, STATE_NONE);
+  int rv = last_io_result;
+  do {
+    State state = next_state_;
+    next_state_ = STATE_NONE;
+    switch (state) {
+      case STATE_RESOLVE_HOST:
+        DCHECK_EQ(OK, rv);
+        rv = DoResolveHost();
+        break;
+      case STATE_RESOLVE_HOST_COMPLETE:
+        rv = DoResolveHostComplete(rv);
+        break;
+      case STATE_GREET_WRITE:
+        DCHECK_EQ(OK, rv);
+        rv = DoGreetWrite();
+        break;
+      case STATE_GREET_WRITE_COMPLETE:
+        rv = DoGreetWriteComplete(rv);
+        break;
+      case STATE_GREET_READ:
+        DCHECK_EQ(OK, rv);
+        rv = DoGreetRead();
+        break;
+      case STATE_GREET_READ_COMPLETE:
+        rv = DoGreetReadComplete(rv);
+        break;
+      case STATE_HANDSHAKE_WRITE:
+        DCHECK_EQ(OK, rv);
+        rv = DoHandshakeWrite();
+        break;
+      case STATE_HANDSHAKE_WRITE_COMPLETE:
+        rv = DoHandshakeWriteComplete(rv);
+        break;
+      case STATE_HANDSHAKE_READ:
+        DCHECK_EQ(OK, rv);
+        rv = DoHandshakeRead();
+        break;
+      case STATE_HANDSHAKE_READ_COMPLETE:
+        rv = DoHandshakeReadComplete(rv);
+        break;
+      default:
+        NOTREACHED() << "bad state";
+        rv = ERR_UNEXPECTED;
+        break;
+    }
+  } while (rv != ERR_IO_PENDING && next_state_ != STATE_NONE);
+  return rv;
+}
+
+int SOCKS5ClientSocket::DoResolveHost() {
+  DCHECK_EQ(kEndPointUnresolved, address_type_);
+
+  next_state_ = STATE_RESOLVE_HOST_COMPLETE;
+  return host_resolver_.Resolve(host_request_info_, &addresses_, &io_callback_);
+}
+
+int SOCKS5ClientSocket::DoResolveHostComplete(int result) {
+  DCHECK_EQ(kEndPointUnresolved, address_type_);
+
+  bool ok = (result == OK);
+  next_state_ = STATE_GREET_WRITE;
+  if (ok) {
+    DCHECK(addresses_.head());
+    struct sockaddr* host_info = addresses_.head()->ai_addr;
+    if (host_info->sa_family == AF_INET) {
+      address_type_ = kEndPointResolvedIPv4;
+    } else if (host_info->sa_family == AF_INET6) {
+      address_type_ = kEndPointResolvedIPv6;
+    }
+  } else {
+    address_type_ = kEndPointFailedDomain;
+  }
+
+  buffer_.clear();
+
+  // Even if DNS resolution fails, we send OK since the server
+  // resolves the domain.
+  return OK;
+}
+
+const char kSOCKS5GreetWriteData[] = { 0x05, 0x01, 0x00 };  // no authentication
+const char kSOCKS5GreetReadData[] = { 0x05, 0x00 };
+
+int SOCKS5ClientSocket::DoGreetWrite() {
+  if (buffer_.empty()) {
+    buffer_ = std::string(kSOCKS5GreetWriteData,
+                          arraysize(kSOCKS5GreetWriteData));
+    bytes_sent_ = 0;
+  }
+
+  next_state_ = STATE_GREET_WRITE_COMPLETE;
+  size_t handshake_buf_len = buffer_.size() - bytes_sent_;
+  handshake_buf_ = new IOBuffer(handshake_buf_len);
+  memcpy(handshake_buf_->data(), &buffer_.data()[bytes_sent_],
+         handshake_buf_len);
+  return transport_->Write(handshake_buf_, handshake_buf_len, &io_callback_);
+}
+
+int SOCKS5ClientSocket::DoGreetWriteComplete(int result) {
+  if (result < 0)
+    return result;
+
+  bytes_sent_ += result;
+  if (bytes_sent_ == buffer_.size()) {
+    buffer_.clear();
+    bytes_received_ = 0;
+    next_state_ = STATE_GREET_READ;
+  } else {
+    next_state_ = STATE_GREET_WRITE;
+  }
+  return OK;
+}
+
+int SOCKS5ClientSocket::DoGreetRead() {
+  next_state_ = STATE_GREET_READ_COMPLETE;
+  size_t handshake_buf_len = kGreetReadHeaderSize - bytes_received_;
+  handshake_buf_ = new IOBuffer(handshake_buf_len);
+  return transport_->Read(handshake_buf_, handshake_buf_len, &io_callback_);
+}
+
+int SOCKS5ClientSocket::DoGreetReadComplete(int result) {
+  if (result < 0)
+    return result;
+
+  if (result == 0)
+    return ERR_CONNECTION_CLOSED;  // Unexpected socket close
+
+  bytes_received_ += result;
+  buffer_.append(handshake_buf_->data(), result);
+  if (bytes_received_ < kGreetReadHeaderSize) {
+    next_state_ = STATE_GREET_READ;
+    return OK;
+  }
+
+  // Got the greet data.
+  if (buffer_[0] != kSOCKS5Version || buffer_[1] != 0x00)
+    return ERR_INVALID_RESPONSE;  // Unknown error
+
+  buffer_.clear();
+  next_state_ = STATE_HANDSHAKE_WRITE;
+  return OK;
+}
+
+int SOCKS5ClientSocket::BuildHandshakeWriteBuffer(std::string* handshake)
+    const {
+  DCHECK_NE(kEndPointUnresolved, address_type_);
+  DCHECK(handshake->empty());
+
+  handshake->push_back(kSOCKS5Version);
+  handshake->push_back(kTunnelCommand);  // Connect command
+  handshake->push_back(kNullByte);  // Reserved null
+
+  handshake->push_back(address_type_);  // The type of connection
+  if (address_type_ == kEndPointFailedDomain) {
+    if(256 <= host_request_info_.hostname().size())
+      return ERR_ADDRESS_INVALID;
+
+    // First add the size of the hostname, followed by the hostname.
+    handshake->push_back(static_cast<unsigned char>(
+        host_request_info_.hostname().size()));
+    handshake->append(host_request_info_.hostname());
+
+  } else if (address_type_ == kEndPointResolvedIPv4) {
+    struct sockaddr_in* ipv4_host =
+        reinterpret_cast<struct sockaddr_in*>(addresses_.head()->ai_addr);
+    handshake->append(reinterpret_cast<char*>(&ipv4_host->sin_addr),
+                      sizeof(ipv4_host->sin_addr));
+
+  } else if (address_type_ == kEndPointResolvedIPv6) {
+    struct sockaddr_in6* ipv6_host =
+        reinterpret_cast<struct sockaddr_in6*>(addresses_.head()->ai_addr);
+    handshake->append(reinterpret_cast<char*>(&ipv6_host->sin6_addr),
+                      sizeof(ipv6_host->sin6_addr));
+
+  } else {
+    NOTREACHED();
+  }
+
+  uint16 nw_port = htons(host_request_info_.port());
+  handshake->append(reinterpret_cast<char*>(&nw_port), sizeof(nw_port));
+  return OK;
+}
+
+// Writes the SOCKS handshake data to the underlying socket connection.
+int SOCKS5ClientSocket::DoHandshakeWrite() {
+  next_state_ = STATE_HANDSHAKE_WRITE_COMPLETE;
+
+  if (buffer_.empty()) {
+    int rv = BuildHandshakeWriteBuffer(&buffer_);
+    if (rv != OK)
+      return rv;
+    bytes_sent_ = 0;
+  }
+
+  int handshake_buf_len = buffer_.size() - bytes_sent_;
+  DCHECK_LT(0, handshake_buf_len);
+  handshake_buf_ = new IOBuffer(handshake_buf_len);
+  memcpy(handshake_buf_->data(), &buffer_[bytes_sent_],
+         handshake_buf_len);
+  return transport_->Write(handshake_buf_, handshake_buf_len, &io_callback_);
+}
+
+int SOCKS5ClientSocket::DoHandshakeWriteComplete(int result) {
+  DCHECK_NE(kEndPointUnresolved, address_type_);
+
+  if (result < 0)
+    return result;
+
+  // We ignore the case when result is 0, since the underlying Write
+  // may return spurious writes while waiting on the socket.
+
+  bytes_sent_ += result;
+  if (bytes_sent_ == buffer_.size()) {
+    next_state_ = STATE_HANDSHAKE_READ;
+    buffer_.clear();
+  } else if (bytes_sent_ < buffer_.size()) {
+    next_state_ = STATE_HANDSHAKE_WRITE;
+  } else {
+    NOTREACHED();
+  }
+
+  return OK;
+}
+
+int SOCKS5ClientSocket::DoHandshakeRead() {
+  DCHECK_NE(kEndPointUnresolved, address_type_);
+
+  next_state_ = STATE_HANDSHAKE_READ_COMPLETE;
+
+  if (buffer_.empty()) {
+    bytes_received_ = 0;
+    read_header_size = kReadHeaderSize;
+  }
+
+  int handshake_buf_len = read_header_size - bytes_received_;
+  handshake_buf_ = new IOBuffer(handshake_buf_len);
+  return transport_->Read(handshake_buf_, handshake_buf_len, &io_callback_);
+}
+
+int SOCKS5ClientSocket::DoHandshakeReadComplete(int result) {
+  DCHECK_NE(kEndPointUnresolved, address_type_);
+
+  if (result < 0)
+    return result;
+
+  // The underlying socket closed unexpectedly.
+  if (result == 0)
+    return ERR_CONNECTION_CLOSED;
+
+  buffer_.append(handshake_buf_->data(), result);
+  bytes_received_ += result;
+
+  // When the first few bytes are read, check how many more are required
+  // and accordingly increase them
+  if (bytes_received_ == kReadHeaderSize) {
+    // TODO(arindam): add error codes to net/error_list.h
+    if (buffer_[0] != kSOCKS5Version || buffer_[2] != kNullByte)
+      return ERR_INVALID_RESPONSE;
+    if (buffer_[1] != 0x00)
+      return ERR_FAILED;
+
+    // We check the type of IP/Domain the server returns and accordingly
+    // increase the size of the response. For domains, we need to read the
+    // size of the domain, so the initial request size is upto the domain
+    // size. Since for IPv4/IPv6 the size is fixed and hence no 'size' is
+    // read, we substract 1 byte from the additional request size.
+    SocksEndPointAddressType address_type =
+        static_cast<SocksEndPointAddressType>(buffer_[3]);
+    if (address_type == kEndPointFailedDomain)
+      read_header_size += static_cast<uint8>(buffer_[4]);
+    else if (address_type == kEndPointResolvedIPv4)
+      read_header_size += sizeof(struct in_addr) - 1;
+    else if (address_type == kEndPointResolvedIPv6)
+      read_header_size += sizeof(struct in6_addr) - 1;
+    else
+      return ERR_INVALID_RESPONSE;
+
+    read_header_size += 2;  // for the port.
+    next_state_ = STATE_HANDSHAKE_READ;
+    return OK;
+  }
+
+  // When the final bytes are read, setup handshake. We ignore the rest
+  // of the response since they represent the SOCKSv5 endpoint and have
+  // no use when doing a tunnel connection.
+  if (bytes_received_ == read_header_size) {
+    completed_handshake_ = true;
+    buffer_.clear();
+    next_state_ = STATE_NONE;
+    return OK;
+  }
+
+  next_state_ = STATE_HANDSHAKE_READ;
+  return OK;
+}
+
+#if defined(OS_LINUX)
+int SOCKS5ClientSocket::GetPeerName(struct sockaddr* name,
+                                    socklen_t* namelen) {
+  return transport_->GetPeerName(name, namelen);
+}
+#endif
+
+}  // namespace net
+