blob: 8cbd379ef7b5cbf7f1a2d69759727698b9b72b23 [file] [log] [blame]
// Copyright (c) 2012 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/socks_client_socket.h"
#include <utility>
#include "base/bind.h"
#include "base/callback_helpers.h"
#include "base/compiler_specific.h"
#include "base/sys_byteorder.h"
#include "net/base/io_buffer.h"
#include "net/log/net_log.h"
#include "net/log/net_log_event_type.h"
#include "net/socket/client_socket_handle.h"
namespace net {
// Every SOCKS server requests a user-id from the client. It is optional
// and we send an empty string.
static const char kEmptyUserId[] = "";
// For SOCKS4, the client sends 8 bytes plus the size of the user-id.
static const unsigned int kWriteHeaderSize = 8;
// For SOCKS4 the server sends 8 bytes for acknowledgement.
static const unsigned int kReadHeaderSize = 8;
// Server Response codes for SOCKS.
static const uint8_t kServerResponseOk = 0x5A;
static const uint8_t kServerResponseRejected = 0x5B;
static const uint8_t kServerResponseNotReachable = 0x5C;
static const uint8_t kServerResponseMismatchedUserId = 0x5D;
static const uint8_t kSOCKSVersion4 = 0x04;
static const uint8_t kSOCKSStreamRequest = 0x01;
// A struct holding the essential details of the SOCKS4 Server Request.
// The port in the header is stored in network byte order.
struct SOCKS4ServerRequest {
uint8_t version;
uint8_t command;
uint16_t nw_port;
uint8_t ip[4];
};
static_assert(sizeof(SOCKS4ServerRequest) == kWriteHeaderSize,
"socks4 server request struct has incorrect size");
// A struct holding details of the SOCKS4 Server Response.
struct SOCKS4ServerResponse {
uint8_t reserved_null;
uint8_t code;
uint16_t port;
uint8_t ip[4];
};
static_assert(sizeof(SOCKS4ServerResponse) == kReadHeaderSize,
"socks4 server response struct has incorrect size");
SOCKSClientSocket::SOCKSClientSocket(
std::unique_ptr<ClientSocketHandle> transport_socket,
const HostResolver::RequestInfo& req_info,
RequestPriority priority,
HostResolver* host_resolver)
: transport_(std::move(transport_socket)),
next_state_(STATE_NONE),
completed_handshake_(false),
bytes_sent_(0),
bytes_received_(0),
was_ever_used_(false),
host_resolver_(host_resolver),
host_request_info_(req_info),
priority_(priority),
net_log_(transport_->socket()->NetLog()) {}
SOCKSClientSocket::~SOCKSClientSocket() {
Disconnect();
}
int SOCKSClientSocket::Connect(const CompletionCallback& callback) {
DCHECK(transport_.get());
DCHECK(transport_->socket());
DCHECK_EQ(STATE_NONE, next_state_);
DCHECK(user_callback_.is_null());
// If already connected, then just return OK.
if (completed_handshake_)
return OK;
next_state_ = STATE_RESOLVE_HOST;
net_log_.BeginEvent(NetLogEventType::SOCKS_CONNECT);
int rv = DoLoop(OK);
if (rv == ERR_IO_PENDING) {
user_callback_ = callback;
} else {
net_log_.EndEventWithNetErrorCode(NetLogEventType::SOCKS_CONNECT, rv);
}
return rv;
}
void SOCKSClientSocket::Disconnect() {
completed_handshake_ = false;
request_.reset();
transport_->socket()->Disconnect();
// Reset other states to make sure they aren't mistakenly used later.
// These are the states initialized by Connect().
next_state_ = STATE_NONE;
user_callback_.Reset();
}
bool SOCKSClientSocket::IsConnected() const {
return completed_handshake_ && transport_->socket()->IsConnected();
}
bool SOCKSClientSocket::IsConnectedAndIdle() const {
return completed_handshake_ && transport_->socket()->IsConnectedAndIdle();
}
const NetLogWithSource& SOCKSClientSocket::NetLog() const {
return net_log_;
}
void SOCKSClientSocket::SetSubresourceSpeculation() {
if (transport_.get() && transport_->socket()) {
transport_->socket()->SetSubresourceSpeculation();
} else {
NOTREACHED();
}
}
void SOCKSClientSocket::SetOmniboxSpeculation() {
if (transport_.get() && transport_->socket()) {
transport_->socket()->SetOmniboxSpeculation();
} else {
NOTREACHED();
}
}
bool SOCKSClientSocket::WasEverUsed() const {
return was_ever_used_;
}
bool SOCKSClientSocket::WasNpnNegotiated() const {
if (transport_.get() && transport_->socket()) {
return transport_->socket()->WasNpnNegotiated();
}
NOTREACHED();
return false;
}
NextProto SOCKSClientSocket::GetNegotiatedProtocol() const {
if (transport_.get() && transport_->socket()) {
return transport_->socket()->GetNegotiatedProtocol();
}
NOTREACHED();
return kProtoUnknown;
}
bool SOCKSClientSocket::GetSSLInfo(SSLInfo* ssl_info) {
if (transport_.get() && transport_->socket()) {
return transport_->socket()->GetSSLInfo(ssl_info);
}
NOTREACHED();
return false;
}
void SOCKSClientSocket::GetConnectionAttempts(ConnectionAttempts* out) const {
out->clear();
}
int64_t SOCKSClientSocket::GetTotalReceivedBytes() const {
return transport_->socket()->GetTotalReceivedBytes();
}
// Read is called by the transport layer above to read. This can only be done
// if the SOCKS handshake is complete.
int SOCKSClientSocket::Read(IOBuffer* buf, int buf_len,
const CompletionCallback& callback) {
DCHECK(completed_handshake_);
DCHECK_EQ(STATE_NONE, next_state_);
DCHECK(user_callback_.is_null());
DCHECK(!callback.is_null());
int rv = transport_->socket()->Read(
buf, buf_len,
base::Bind(&SOCKSClientSocket::OnReadWriteComplete,
base::Unretained(this), callback));
if (rv > 0)
was_ever_used_ = true;
return rv;
}
// Write is called by the transport layer. This can only be done if the
// SOCKS handshake is complete.
int SOCKSClientSocket::Write(IOBuffer* buf, int buf_len,
const CompletionCallback& callback) {
DCHECK(completed_handshake_);
DCHECK_EQ(STATE_NONE, next_state_);
DCHECK(user_callback_.is_null());
DCHECK(!callback.is_null());
int rv = transport_->socket()->Write(
buf, buf_len,
base::Bind(&SOCKSClientSocket::OnReadWriteComplete,
base::Unretained(this), callback));
if (rv > 0)
was_ever_used_ = true;
return rv;
}
int SOCKSClientSocket::SetReceiveBufferSize(int32_t size) {
return transport_->socket()->SetReceiveBufferSize(size);
}
int SOCKSClientSocket::SetSendBufferSize(int32_t size) {
return transport_->socket()->SetSendBufferSize(size);
}
void SOCKSClientSocket::DoCallback(int result) {
DCHECK_NE(ERR_IO_PENDING, result);
DCHECK(!user_callback_.is_null());
// Since Run() may result in Read being called,
// clear user_callback_ up front.
DVLOG(1) << "Finished setting up SOCKS handshake";
base::ResetAndReturn(&user_callback_).Run(result);
}
void SOCKSClientSocket::OnIOComplete(int result) {
DCHECK_NE(STATE_NONE, next_state_);
int rv = DoLoop(result);
if (rv != ERR_IO_PENDING) {
net_log_.EndEventWithNetErrorCode(NetLogEventType::SOCKS_CONNECT, rv);
DoCallback(rv);
}
}
void SOCKSClientSocket::OnReadWriteComplete(const CompletionCallback& callback,
int result) {
DCHECK_NE(ERR_IO_PENDING, result);
DCHECK(!callback.is_null());
if (result > 0)
was_ever_used_ = true;
callback.Run(result);
}
int SOCKSClientSocket::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_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 SOCKSClientSocket::DoResolveHost() {
next_state_ = STATE_RESOLVE_HOST_COMPLETE;
// SOCKS4 only supports IPv4 addresses, so only try getting the IPv4
// addresses for the target host.
host_request_info_.set_address_family(ADDRESS_FAMILY_IPV4);
return host_resolver_->Resolve(
host_request_info_, priority_, &addresses_,
base::Bind(&SOCKSClientSocket::OnIOComplete, base::Unretained(this)),
&request_, net_log_);
}
int SOCKSClientSocket::DoResolveHostComplete(int result) {
if (result != OK) {
// Resolving the hostname failed; fail the request rather than automatically
// falling back to SOCKS4a (since it can be confusing to see invalid IP
// addresses being sent to the SOCKS4 server when it doesn't support 4A.)
return result;
}
next_state_ = STATE_HANDSHAKE_WRITE;
return OK;
}
// Builds the buffer that is to be sent to the server.
const std::string SOCKSClientSocket::BuildHandshakeWriteBuffer() const {
SOCKS4ServerRequest request;
request.version = kSOCKSVersion4;
request.command = kSOCKSStreamRequest;
request.nw_port = base::HostToNet16(host_request_info_.port());
DCHECK(!addresses_.empty());
const IPEndPoint& endpoint = addresses_.front();
// We disabled IPv6 results when resolving the hostname, so none of the
// results in the list will be IPv6.
// TODO(eroman): we only ever use the first address in the list. It would be
// more robust to try all the IP addresses we have before
// failing the connect attempt.
CHECK_EQ(ADDRESS_FAMILY_IPV4, endpoint.GetFamily());
CHECK_LE(endpoint.address().size(), sizeof(request.ip));
memcpy(&request.ip, &endpoint.address().bytes()[0],
endpoint.address().size());
DVLOG(1) << "Resolved Host is : " << endpoint.ToStringWithoutPort();
std::string handshake_data(reinterpret_cast<char*>(&request),
sizeof(request));
handshake_data.append(kEmptyUserId, arraysize(kEmptyUserId));
return handshake_data;
}
// Writes the SOCKS handshake data to the underlying socket connection.
int SOCKSClientSocket::DoHandshakeWrite() {
next_state_ = STATE_HANDSHAKE_WRITE_COMPLETE;
if (buffer_.empty()) {
buffer_ = BuildHandshakeWriteBuffer();
bytes_sent_ = 0;
}
int handshake_buf_len = buffer_.size() - bytes_sent_;
DCHECK_GT(handshake_buf_len, 0);
handshake_buf_ = new IOBuffer(handshake_buf_len);
memcpy(handshake_buf_->data(), &buffer_[bytes_sent_],
handshake_buf_len);
return transport_->socket()->Write(
handshake_buf_.get(),
handshake_buf_len,
base::Bind(&SOCKSClientSocket::OnIOComplete, base::Unretained(this)));
}
int SOCKSClientSocket::DoHandshakeWriteComplete(int result) {
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 {
return ERR_UNEXPECTED;
}
return OK;
}
int SOCKSClientSocket::DoHandshakeRead() {
next_state_ = STATE_HANDSHAKE_READ_COMPLETE;
if (buffer_.empty()) {
bytes_received_ = 0;
}
int handshake_buf_len = kReadHeaderSize - bytes_received_;
handshake_buf_ = new IOBuffer(handshake_buf_len);
return transport_->socket()->Read(
handshake_buf_.get(),
handshake_buf_len,
base::Bind(&SOCKSClientSocket::OnIOComplete, base::Unretained(this)));
}
int SOCKSClientSocket::DoHandshakeReadComplete(int result) {
if (result < 0)
return result;
// The underlying socket closed unexpectedly.
if (result == 0)
return ERR_CONNECTION_CLOSED;
if (bytes_received_ + result > kReadHeaderSize) {
// TODO(eroman): Describe failure in NetLog.
return ERR_SOCKS_CONNECTION_FAILED;
}
buffer_.append(handshake_buf_->data(), result);
bytes_received_ += result;
if (bytes_received_ < kReadHeaderSize) {
next_state_ = STATE_HANDSHAKE_READ;
return OK;
}
const SOCKS4ServerResponse* response =
reinterpret_cast<const SOCKS4ServerResponse*>(buffer_.data());
if (response->reserved_null != 0x00) {
DVLOG(1) << "Unknown response from SOCKS server.";
return ERR_SOCKS_CONNECTION_FAILED;
}
switch (response->code) {
case kServerResponseOk:
completed_handshake_ = true;
return OK;
case kServerResponseRejected:
DVLOG(1) << "SOCKS request rejected or failed";
return ERR_SOCKS_CONNECTION_FAILED;
case kServerResponseNotReachable:
DVLOG(1) << "SOCKS request failed because client is not running "
<< "identd (or not reachable from the server)";
return ERR_SOCKS_CONNECTION_HOST_UNREACHABLE;
case kServerResponseMismatchedUserId:
DVLOG(1) << "SOCKS request failed because client's identd could "
<< "not confirm the user ID string in the request";
return ERR_SOCKS_CONNECTION_FAILED;
default:
DVLOG(1) << "SOCKS server sent unknown response";
return ERR_SOCKS_CONNECTION_FAILED;
}
// Note: we ignore the last 6 bytes as specified by the SOCKS protocol
}
int SOCKSClientSocket::GetPeerAddress(IPEndPoint* address) const {
return transport_->socket()->GetPeerAddress(address);
}
int SOCKSClientSocket::GetLocalAddress(IPEndPoint* address) const {
return transport_->socket()->GetLocalAddress(address);
}
} // namespace net