premiere-libtorrent/src/socks5_stream.cpp

518 lines
12 KiB
C++

/*
Copyright (c) 2007, Arvid Norberg
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* 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.
* Neither the name of the author nor the names of its
contributors may be used to endorse or promote products derived
from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 COPYRIGHT OWNER OR CONTRIBUTORS 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 "libtorrent/pch.hpp"
#include "libtorrent/socks5_stream.hpp"
#include "libtorrent/assert.hpp"
#include "libtorrent/socket_io.hpp"
namespace libtorrent
{
socks_error_category socks_category;
#if BOOST_VERSION >= 103500
const char* socks_error_category::name() const
{
return "socks error";
}
std::string socks_error_category::message(int ev) const
{
static char const* messages[] =
{
"SOCKS no error",
"SOCKS unsupported version",
"SOCKS unsupported authentication method",
"SOCKS unsupported authentication version",
"SOCKS authentication error",
"SOCKS username required",
"SOCKS general failure",
"SOCKS command not supported",
"SOCKS no identd running",
"SOCKS identd could not identify username"
};
if (ev < 0 || ev > socks_error::num_errors) return "unknown error";
return messages[ev];
}
#endif
void socks5_stream::name_lookup(error_code const& e, tcp::resolver::iterator i
, boost::shared_ptr<handler_type> h)
{
if (e || i == tcp::resolver::iterator())
{
(*h)(e);
error_code ec;
close(ec);
return;
}
error_code ec;
m_sock.open(i->endpoint().protocol(), ec);
if (ec)
{
(*h)(ec);
close(ec);
return;
}
// TOOD: we could bind the socket here, since we know what the
// target endpoint is of the proxy
m_sock.async_connect(i->endpoint(), boost::bind(
&socks5_stream::connected, this, _1, h));
}
void socks5_stream::connected(error_code const& e, boost::shared_ptr<handler_type> h)
{
if (e)
{
(*h)(e);
error_code ec;
close(ec);
return;
}
using namespace libtorrent::detail;
if (m_version == 5)
{
// send SOCKS5 authentication methods
m_buffer.resize(m_user.empty()?3:4);
char* p = &m_buffer[0];
write_uint8(5, p); // SOCKS VERSION 5
if (m_user.empty())
{
write_uint8(1, p); // 1 authentication method (no auth)
write_uint8(0, p); // no authentication
}
else
{
write_uint8(2, p); // 2 authentication methods
write_uint8(0, p); // no authentication
write_uint8(2, p); // username/password
}
async_write(m_sock, asio::buffer(m_buffer)
, boost::bind(&socks5_stream::handshake1, this, _1, h));
}
else if (m_version == 4)
{
socks_connect(h);
}
else
{
(*h)(error_code(socks_error::unsupported_version, socks_category));
error_code ec;
close(ec);
}
}
void socks5_stream::handshake1(error_code const& e, boost::shared_ptr<handler_type> h)
{
if (e)
{
(*h)(e);
error_code ec;
close(ec);
return;
}
m_buffer.resize(2);
async_read(m_sock, asio::buffer(m_buffer)
, boost::bind(&socks5_stream::handshake2, this, _1, h));
}
void socks5_stream::handshake2(error_code const& e, boost::shared_ptr<handler_type> h)
{
if (e)
{
(*h)(e);
error_code ec;
close(ec);
return;
}
using namespace libtorrent::detail;
char* p = &m_buffer[0];
int version = read_uint8(p);
int method = read_uint8(p);
if (version < m_version)
{
(*h)(error_code(socks_error::unsupported_version, socks_category));
error_code ec;
close(ec);
return;
}
if (method == 0)
{
socks_connect(h);
}
else if (method == 2)
{
if (m_user.empty())
{
(*h)(error_code(socks_error::username_required, socks_category));
error_code ec;
close(ec);
return;
}
// start sub-negotiation
m_buffer.resize(m_user.size() + m_password.size() + 3);
char* p = &m_buffer[0];
write_uint8(1, p);
write_uint8(m_user.size(), p);
write_string(m_user, p);
write_uint8(m_password.size(), p);
write_string(m_password, p);
async_write(m_sock, asio::buffer(m_buffer)
, boost::bind(&socks5_stream::handshake3, this, _1, h));
}
else
{
(*h)(error_code(socks_error::unsupported_authentication_method, socks_category));
error_code ec;
close(ec);
return;
}
}
void socks5_stream::handshake3(error_code const& e
, boost::shared_ptr<handler_type> h)
{
if (e)
{
(*h)(e);
error_code ec;
close(ec);
return;
}
m_buffer.resize(2);
async_read(m_sock, asio::buffer(m_buffer)
, boost::bind(&socks5_stream::handshake4, this, _1, h));
}
void socks5_stream::handshake4(error_code const& e
, boost::shared_ptr<handler_type> h)
{
if (e)
{
(*h)(e);
error_code ec;
close(ec);
return;
}
using namespace libtorrent::detail;
char* p = &m_buffer[0];
int version = read_uint8(p);
int status = read_uint8(p);
if (version != 1)
{
(*h)(error_code(socks_error::unsupported_authentication_version, socks_category));
error_code ec;
close(ec);
return;
}
if (status != 0)
{
(*h)(error_code(socks_error::authentication_error, socks_category));
error_code ec;
close(ec);
return;
}
std::vector<char>().swap(m_buffer);
socks_connect(h);
}
void socks5_stream::socks_connect(boost::shared_ptr<handler_type> h)
{
using namespace libtorrent::detail;
if (m_version == 5)
{
// send SOCKS5 connect command
m_buffer.resize(6 + (!m_dst_name.empty()
?m_dst_name.size() + 1
:(m_remote_endpoint.address().is_v4()?4:16)));
char* p = &m_buffer[0];
write_uint8(5, p); // SOCKS VERSION 5
write_uint8(m_command, p); // CONNECT/BIND command
write_uint8(0, p); // reserved
if (!m_dst_name.empty())
{
write_uint8(3, p); // address type
TORRENT_ASSERT(m_dst_name.size() <= 255);
write_uint8(m_dst_name.size(), p);
std::copy(m_dst_name.begin(), m_dst_name.end(), p);
p += m_dst_name.size();
}
else
{
write_uint8(m_remote_endpoint.address().is_v4()?1:4, p); // address type
write_address(m_remote_endpoint.address(), p);
}
write_uint16(m_remote_endpoint.port(), p);
}
else if (m_version == 4)
{
m_buffer.resize(m_user.size() + 9);
char* p = &m_buffer[0];
write_uint8(4, p); // SOCKS VERSION 4
write_uint8(m_command, p); // CONNECT/BIND command
write_uint16(m_remote_endpoint.port(), p);
write_uint32(m_remote_endpoint.address().to_v4().to_ulong(), p);
std::copy(m_user.begin(), m_user.end(), p);
p += m_user.size();
write_uint8(0, p); // NULL terminator
}
else
{
(*h)(error_code(socks_error::unsupported_version, socks_category));
error_code ec;
close(ec);
return;
}
async_write(m_sock, asio::buffer(m_buffer)
, boost::bind(&socks5_stream::connect1, this, _1, h));
}
void socks5_stream::connect1(error_code const& e, boost::shared_ptr<handler_type> h)
{
if (e)
{
(*h)(e);
error_code ec;
close(ec);
return;
}
if (m_version == 5)
m_buffer.resize(6 + 4); // assume an IPv4 address
else if (m_version == 4)
m_buffer.resize(8);
async_read(m_sock, asio::buffer(m_buffer)
, boost::bind(&socks5_stream::connect2, this, _1, h));
}
void socks5_stream::connect2(error_code const& e, boost::shared_ptr<handler_type> h)
{
if (e)
{
(*h)(e);
error_code ec;
close(ec);
return;
}
using namespace libtorrent::detail;
// send SOCKS5 connect command
char* p = &m_buffer[0];
int version = read_uint8(p);
int response = read_uint8(p);
if (m_version == 5)
{
if (version < m_version)
{
(*h)(error_code(socks_error::unsupported_version, socks_category));
error_code ec;
close(ec);
return;
}
if (response != 0)
{
error_code e(socks_error::general_failure, socks_category);
switch (response)
{
case 2: e = asio::error::no_permission; break;
case 3: e = asio::error::network_unreachable; break;
case 4: e = asio::error::host_unreachable; break;
case 5: e = asio::error::connection_refused; break;
case 6: e = asio::error::timed_out; break;
case 7: e = error_code(socks_error::command_not_supported, socks_category); break;
case 8: e = asio::error::address_family_not_supported; break;
}
(*h)(e);
error_code ec;
close(ec);
return;
}
p += 1; // reserved
int atyp = read_uint8(p);
// we ignore the proxy IP it was bound to
if (atyp == 1)
{
if (m_command == 2)
{
if (m_listen == 0)
{
m_listen = 1;
connect1(e, h);
return;
}
m_remote_endpoint.address(read_v4_address(p));
m_remote_endpoint.port(read_uint16(p));
std::vector<char>().swap(m_buffer);
(*h)(e);
}
else
{
std::vector<char>().swap(m_buffer);
(*h)(e);
}
return;
}
int extra_bytes = 0;
if (atyp == 4)
{
extra_bytes = 12;
}
else if (atyp == 3)
{
extra_bytes = read_uint8(p) - 3;
}
else
{
(*h)(asio::error::address_family_not_supported);
error_code ec;
close(ec);
return;
}
m_buffer.resize(m_buffer.size() + extra_bytes);
TORRENT_ASSERT(extra_bytes > 0);
async_read(m_sock, asio::buffer(&m_buffer[m_buffer.size() - extra_bytes], extra_bytes)
, boost::bind(&socks5_stream::connect3, this, _1, h));
}
else if (m_version == 4)
{
if (version != 0)
{
(*h)(error_code(socks_error::general_failure, socks_category));
error_code ec;
close(ec);
return;
}
// access granted
if (response == 90)
{
if (m_command == 2)
{
if (m_listen == 0)
{
m_listen = 1;
connect1(e, h);
return;
}
m_remote_endpoint.address(read_v4_address(p));
m_remote_endpoint.port(read_uint16(p));
std::vector<char>().swap(m_buffer);
(*h)(e);
}
else
{
std::vector<char>().swap(m_buffer);
(*h)(e);
}
return;
}
int code = socks_error::general_failure;
switch (response)
{
case 91: code = socks_error::authentication_error; break;
case 92: code = socks_error::no_identd; break;
case 93: code = socks_error::identd_error; break;
}
error_code e(code, socks_category);
(*h)(e);
close(e);
}
}
void socks5_stream::connect3(error_code const& e, boost::shared_ptr<handler_type> h)
{
using namespace libtorrent::detail;
if (e)
{
(*h)(e);
error_code ec;
close(ec);
return;
}
if (m_command == 2)
{
if (m_listen == 0)
{
m_listen = 1;
connect1(e, h);
return;
}
char* p = &m_buffer[0];
p += 2; // version and response code
int atyp = read_uint8(p);
TORRENT_ASSERT(atyp == 3 || atyp == 4);
if (atyp == 4)
{
// we don't support resolving the endpoint address
// if we receive a domain name, just set the remote
// endpoint to INADDR_ANY
m_remote_endpoint = tcp::endpoint();
}
else if (atyp == 3)
{
m_remote_endpoint.address(read_v4_address(p));
m_remote_endpoint.port(read_uint16(p));
}
}
std::vector<char>().swap(m_buffer);
(*h)(e);
}
}