premiere-libtorrent/src/socks5_stream.cpp

422 lines
11 KiB
C++

/*
Copyright (c) 2007-2016, 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/socks5_stream.hpp"
#include "libtorrent/socket_io.hpp"
using namespace std::placeholders;
namespace libtorrent {
namespace socks_error
{
boost::system::error_code make_error_code(socks_error_code e)
{
return error_code(e, socks_category());
}
}
struct socks_error_category : boost::system::error_category
{
const char* name() const BOOST_SYSTEM_NOEXCEPT override
{ return "socks error"; }
std::string message(int ev) const override
{
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];
}
boost::system::error_condition default_error_condition(
int ev) const BOOST_SYSTEM_NOEXCEPT override
{ return boost::system::error_condition(ev, *this); }
};
boost::system::error_category& socks_category()
{
static socks_error_category cat;
return cat;
}
void socks5_stream::name_lookup(error_code const& e, tcp::resolver::iterator i
, handler_type& h)
{
COMPLETE_ASYNC("socks5_stream::name_lookup");
if (handle_error(e, h)) return;
error_code ec;
if (!m_sock.is_open())
{
m_sock.open(i->endpoint().protocol(), ec);
if (handle_error(ec, h)) return;
}
// TODO: we could bind the socket here, since we know what the
// target endpoint is of the proxy
ADD_OUTSTANDING_ASYNC("socks5_stream::connected");
m_sock.async_connect(i->endpoint(), std::bind(
&socks5_stream::connected, this, _1, std::move(h)));
}
void socks5_stream::connected(error_code const& e, handler_type& h)
{
COMPLETE_ASYNC("socks5_stream::connected");
if (handle_error(e, h)) 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
}
ADD_OUTSTANDING_ASYNC("socks5_stream::handshake1");
async_write(m_sock, boost::asio::buffer(m_buffer)
, std::bind(&socks5_stream::handshake1, this, _1, std::move(h)));
}
else if (m_version == 4)
{
socks_connect(std::move(h));
}
else
{
h(socks_error::unsupported_version);
}
}
void socks5_stream::handshake1(error_code const& e, handler_type& h)
{
COMPLETE_ASYNC("socks5_stream::handshake1");
if (handle_error(e, h)) return;
ADD_OUTSTANDING_ASYNC("socks5_stream::handshake2");
m_buffer.resize(2);
async_read(m_sock, boost::asio::buffer(m_buffer)
, std::bind(&socks5_stream::handshake2, this, _1, std::move(h)));
}
void socks5_stream::handshake2(error_code const& e, handler_type& h)
{
COMPLETE_ASYNC("socks5_stream::handshake2");
if (handle_error(e, h)) 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(socks_error::unsupported_version);
return;
}
if (method == 0)
{
socks_connect(std::move(h));
}
else if (method == 2)
{
if (m_user.empty())
{
h(socks_error::username_required);
return;
}
// start sub-negotiation
m_buffer.resize(m_user.size() + m_password.size() + 3);
p = &m_buffer[0];
write_uint8(1, p);
TORRENT_ASSERT(m_user.size() < 0x100);
write_uint8(uint8_t(m_user.size()), p);
write_string(m_user, p);
TORRENT_ASSERT(m_password.size() < 0x100);
write_uint8(uint8_t(m_password.size()), p);
write_string(m_password, p);
ADD_OUTSTANDING_ASYNC("socks5_stream::handshake3");
async_write(m_sock, boost::asio::buffer(m_buffer)
, std::bind(&socks5_stream::handshake3, this, _1, std::move(h)));
}
else
{
h(socks_error::unsupported_authentication_method);
return;
}
}
void socks5_stream::handshake3(error_code const& e
, handler_type& h)
{
COMPLETE_ASYNC("socks5_stream::handshake3");
if (handle_error(e, h)) return;
ADD_OUTSTANDING_ASYNC("socks5_stream::handshake4");
m_buffer.resize(2);
async_read(m_sock, boost::asio::buffer(m_buffer)
, std::bind(&socks5_stream::handshake4, this, _1, std::move(h)));
}
void socks5_stream::handshake4(error_code const& e
, handler_type& h)
{
COMPLETE_ASYNC("socks5_stream::handshake4");
if (handle_error(e, h)) return;
using namespace libtorrent::detail;
char* p = &m_buffer[0];
int version = read_uint8(p);
int status = read_uint8(p);
if (version != 1)
{
h(socks_error::unsupported_authentication_version);
return;
}
if (status != 0)
{
h(socks_error::authentication_error);
return;
}
std::vector<char>().swap(m_buffer);
socks_connect(std::move(h));
}
void socks5_stream::socks_connect(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(std::uint8_t(m_command), p); // CONNECT command
write_uint8(0, p); // reserved
if (!m_dst_name.empty())
{
write_uint8(3, p); // address type
TORRENT_ASSERT(m_dst_name.size() < 0x100);
write_uint8(uint8_t(m_dst_name.size()), p);
std::copy(m_dst_name.begin(), m_dst_name.end(), p);
p += m_dst_name.size();
}
else
{
// we either need a hostname or a valid endpoint
TORRENT_ASSERT(m_remote_endpoint.address() != address());
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)
{
// SOCKS4 only supports IPv4
if (!m_remote_endpoint.address().is_v4())
{
h(boost::asio::error::address_family_not_supported);
return;
}
m_buffer.resize(m_user.size() + 9);
char* p = &m_buffer[0];
write_uint8(4, p); // SOCKS VERSION 4
write_uint8(std::uint8_t(m_command), p); // CONNECT 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); // 0-terminator
}
else
{
h(socks_error::unsupported_version);
return;
}
ADD_OUTSTANDING_ASYNC("socks5_stream::connect1");
async_write(m_sock, boost::asio::buffer(m_buffer)
, std::bind(&socks5_stream::connect1, this, _1, std::move(h)));
}
void socks5_stream::connect1(error_code const& e, handler_type& h)
{
COMPLETE_ASYNC("socks5_stream::connect1");
if (handle_error(e, h)) return;
if (m_version == 5)
m_buffer.resize(6 + 4); // assume an IPv4 address
else if (m_version == 4)
m_buffer.resize(8);
ADD_OUTSTANDING_ASYNC("socks5_stream::connect2");
async_read(m_sock, boost::asio::buffer(m_buffer)
, std::bind(&socks5_stream::connect2, this, _1, std::move(h)));
}
void socks5_stream::connect2(error_code const& e, handler_type& h)
{
COMPLETE_ASYNC("socks5_stream::connect2");
if (handle_error(e, h)) return;
using namespace libtorrent::detail;
char const* p = &m_buffer[0];
int const version = read_uint8(p);
int const response = read_uint8(p);
if (m_version == 5)
{
if (version < m_version)
{
h(socks_error::unsupported_version);
return;
}
if (response != 0)
{
error_code ec(socks_error::general_failure);
switch (response)
{
case 2: ec = boost::asio::error::no_permission; break;
case 3: ec = boost::asio::error::network_unreachable; break;
case 4: ec = boost::asio::error::host_unreachable; break;
case 5: ec = boost::asio::error::connection_refused; break;
case 6: ec = boost::asio::error::timed_out; break;
case 7: ec = socks_error::command_not_supported; break;
case 8: ec = boost::asio::error::address_family_not_supported; break;
}
h(ec);
return;
}
p += 1; // reserved
int const atyp = read_uint8(p);
// read the proxy IP it was bound to (this is variable length depending
// on address type)
if (atyp == 1)
{
std::vector<char>().swap(m_buffer);
h(e);
return;
}
std::size_t extra_bytes = 0;
if (atyp == 4)
{
// IPv6
extra_bytes = 12;
}
else if (atyp == 3)
{
// hostname with length prefix
extra_bytes = read_uint8(p) - 3;
}
else
{
h(boost::asio::error::address_family_not_supported);
return;
}
m_buffer.resize(m_buffer.size() + extra_bytes);
ADD_OUTSTANDING_ASYNC("socks5_stream::connect3");
TORRENT_ASSERT(extra_bytes > 0);
async_read(m_sock, boost::asio::buffer(&m_buffer[m_buffer.size() - extra_bytes], extra_bytes)
, std::bind(&socks5_stream::connect3, this, _1, std::move(h)));
}
else if (m_version == 4)
{
if (version != 0)
{
h(socks_error::general_failure);
return;
}
// access granted
if (response == 90)
{
std::vector<char>().swap(m_buffer);
h(e);
return;
}
error_code ec(socks_error::general_failure);
switch (response)
{
case 91: ec = boost::asio::error::connection_refused; break;
case 92: ec = socks_error::no_identd; break;
case 93: ec = socks_error::identd_error; break;
}
h(ec);
}
}
void socks5_stream::connect3(error_code const& e, handler_type& h)
{
COMPLETE_ASYNC("socks5_stream::connect3");
using namespace libtorrent::detail;
if (handle_error(e, h)) return;
std::vector<char>().swap(m_buffer);
h(e);
}
}