wownero/src/net/socks.cpp

333 lines
12 KiB
C++
Raw Normal View History

// Copyright (c) 2018-2019, The Monero Project
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without modification, are
// permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this list of
// conditions and the following disclaimer.
//
// 2. 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.
//
// 3. Neither the name of the copyright holder 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 HOLDER 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 "socks.h"
#include <algorithm>
#include <boost/asio/buffer.hpp>
#include <boost/asio/read.hpp>
#include <boost/asio/write.hpp>
#include <boost/endian/arithmetic.hpp>
#include <boost/endian/conversion.hpp>
#include <cstring>
#include <limits>
#include <string>
#include "net/net_utils_base.h"
#include "net/tor_address.h"
2019-01-21 16:50:03 +00:00
#include "net/i2p_address.h"
namespace net
{
namespace socks
{
namespace
{
constexpr const unsigned v4_reply_size = 8;
constexpr const std::uint8_t v4_connect_command = 1;
constexpr const std::uint8_t v4tor_resolve_command = 0xf0;
constexpr const std::uint8_t v4_request_granted = 90;
struct v4_header
{
std::uint8_t version;
std::uint8_t command_code;
boost::endian::big_uint16_t port;
boost::endian::big_uint32_t ip;
};
std::size_t write_domain_header(epee::span<std::uint8_t> out, const std::uint8_t command, const std::uint16_t port, const boost::string_ref domain)
{
if (std::numeric_limits<std::size_t>::max() - sizeof(v4_header) - 2 < domain.size())
return 0;
const std::size_t buf_size = sizeof(v4_header) + domain.size() + 2;
if (out.size() < buf_size)
return 0;
// version 4, 1 indicates invalid ip for domain extension
const v4_header temp{4, command, port, std::uint32_t(1)};
std::memcpy(out.data(), std::addressof(temp), sizeof(temp));
out.remove_prefix(sizeof(temp));
*(out.data()) = 0;
out.remove_prefix(1);
std::memcpy(out.data(), domain.data(), domain.size());
out.remove_prefix(domain.size());
*(out.data()) = 0;
return buf_size;
}
struct socks_category : boost::system::error_category
{
explicit socks_category() noexcept
: boost::system::error_category()
{}
const char* name() const noexcept override
{
return "net::socks::error_category";
}
virtual std::string message(int value) const override
{
switch (socks::error(value))
{
case socks::error::rejected:
return "Socks request rejected or failed";
case socks::error::identd_connection:
return "Socks request rejected because server cannot connect to identd on the client";
case socks::error::identd_user:
return "Socks request rejected because the client program and identd report different user-ids";
case socks::error::bad_read:
return "Socks boost::async_read read fewer bytes than expected";
case socks::error::bad_write:
return "Socks boost::async_write wrote fewer bytes than expected";
case socks::error::unexpected_version:
return "Socks server returned unexpected version in reply";
default:
break;
}
return "Unknown net::socks::error";
}
boost::system::error_condition default_error_condition(int value) const noexcept override
{
switch (socks::error(value))
{
case socks::error::bad_read:
case socks::error::bad_write:
return boost::system::errc::io_error;
case socks::error::unexpected_version:
return boost::system::errc::protocol_error;
default:
break;
};
if (1 <= value && value <= 256)
return boost::system::errc::protocol_error;
return boost::system::error_condition{value, *this};
}
};
}
const boost::system::error_category& error_category() noexcept
{
static const socks_category instance{};
return instance;
}
struct client::completed
{
std::shared_ptr<client> self_;
void operator()(const boost::system::error_code error, const std::size_t bytes) const
{
static_assert(1 < sizeof(self_->buffer_), "buffer too small for v4 response");
if (self_)
{
client& self = *self_;
self.buffer_size_ = std::min(bytes, sizeof(self.buffer_));
if (error)
self.done(error, std::move(self_));
else if (self.buffer().size() < sizeof(v4_header))
self.done(socks::error::bad_read, std::move(self_));
else if (self.buffer_[0] != 0) // response version
self.done(socks::error::unexpected_version, std::move(self_));
else if (self.buffer_[1] != v4_request_granted)
self.done(socks::error(int(self.buffer_[1]) + 1), std::move(self_));
else
self.done(boost::system::error_code{}, std::move(self_));
}
}
};
struct client::read
{
std::shared_ptr<client> self_;
static boost::asio::mutable_buffers_1 get_buffer(client& self) noexcept
{
static_assert(sizeof(v4_header) <= sizeof(self.buffer_), "buffer too small for v4 response");
return boost::asio::buffer(self.buffer_, sizeof(v4_header));
}
void operator()(const boost::system::error_code error, const std::size_t bytes)
{
if (self_)
{
client& self = *self_;
if (error)
self.done(error, std::move(self_));
else if (bytes < self.buffer().size())
self.done(socks::error::bad_write, std::move(self_));
else
boost::asio::async_read(self.proxy_, get_buffer(self), self.strand_.wrap(completed{std::move(self_)}));
}
}
};
struct client::write
{
std::shared_ptr<client> self_;
static boost::asio::const_buffers_1 get_buffer(client const& self) noexcept
{
return boost::asio::buffer(self.buffer_, self.buffer_size_);
}
void operator()(const boost::system::error_code error)
{
if (self_)
{
client& self = *self_;
if (error)
self.done(error, std::move(self_));
else
boost::asio::async_write(self.proxy_, get_buffer(self), self.strand_.wrap(read{std::move(self_)}));
}
}
};
client::client(stream_type::socket&& proxy, socks::version ver)
: proxy_(std::move(proxy)), strand_(proxy_.get_io_service()), buffer_size_(0), buffer_(), ver_(ver)
{}
client::~client() {}
bool client::set_connect_command(const epee::net_utils::ipv4_network_address& address)
{
switch (socks_version())
{
case version::v4:
case version::v4a:
case version::v4a_tor:
break;
default:
return false;
}
static_assert(sizeof(v4_header) < sizeof(buffer_), "buffer size too small for request");
static_assert(0 < sizeof(buffer_), "buffer size too small for null termination");
// version 4
const v4_header temp{4, v4_connect_command, address.port(), boost::endian::big_to_native(address.ip())};
std::memcpy(std::addressof(buffer_), std::addressof(temp), sizeof(temp));
buffer_[sizeof(temp)] = 0;
buffer_size_ = sizeof(temp) + 1;
return true;
}
bool client::set_connect_command(const boost::string_ref domain, std::uint16_t port)
{
switch (socks_version())
{
case version::v4a:
case version::v4a_tor:
break;
default:
return false;
}
const std::size_t buf_used = write_domain_header(buffer_, v4_connect_command, port, domain);
buffer_size_ = buf_used;
return buf_used != 0;
}
bool client::set_connect_command(const net::tor_address& address)
{
if (!address.is_unknown())
return set_connect_command(address.host_str(), address.port());
return false;
2019-01-21 16:50:03 +00:00
}
bool client::set_connect_command(const net::i2p_address& address)
{
if (!address.is_unknown())
return set_connect_command(address.host_str(), address.port());
return false;
}
bool client::set_resolve_command(boost::string_ref domain)
{
if (socks_version() != version::v4a_tor)
return false;
const std::size_t buf_used = write_domain_header(buffer_, v4tor_resolve_command, 0, domain);
buffer_size_ = buf_used;
return buf_used != 0;
}
bool client::connect_and_send(std::shared_ptr<client> self, const stream_type::endpoint& proxy_address)
{
if (self && !self->buffer().empty())
{
client& alias = *self;
alias.proxy_.async_connect(proxy_address, alias.strand_.wrap(write{std::move(self)}));
return true;
}
return false;
}
bool client::send(std::shared_ptr<client> self)
{
if (self && !self->buffer().empty())
{
client& alias = *self;
boost::asio::async_write(alias.proxy_, write::get_buffer(alias), alias.strand_.wrap(read{std::move(self)}));
return true;
}
return false;
}
void client::async_close::operator()(boost::system::error_code error)
{
if (self_ && error != boost::system::errc::operation_canceled)
{
const std::shared_ptr<client> self = std::move(self_);
self->strand_.dispatch([self] ()
{
if (self && self->proxy_.is_open())
{
self->proxy_.shutdown(boost::asio::ip::tcp::socket::shutdown_both);
self->proxy_.close();
}
});
}
}
} // socks
} // net