diff options
Diffstat (limited to 'src/net/socks.h')
| -rw-r--r-- | src/net/socks.h | 225 |
1 files changed, 225 insertions, 0 deletions
diff --git a/src/net/socks.h b/src/net/socks.h new file mode 100644 index 000000000..d29a51ccb --- /dev/null +++ b/src/net/socks.h @@ -0,0 +1,225 @@ +// Copyright (c) 2018, 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. + +#pragma once + +#include <cstdint> +#include <boost/asio/ip/tcp.hpp> +#include <boost/asio/io_service.hpp> +#include <boost/system/error_code.hpp> +#include <boost/type_traits/integral_constant.hpp> +#include <boost/utility/string_ref.hpp> +#include <memory> +#include <utility> + +#include "net/fwd.h" +#include "span.h" + +namespace epee +{ +namespace net_utils +{ + class ipv4_network_address; +} +} + +namespace net +{ +namespace socks +{ + //! Supported socks variants. + enum class version : std::uint8_t + { + v4 = 0, + v4a, + v4a_tor //!< Extensions defined in Tor codebase + }; + + //! Possible errors with socks communication. Defined in https://www.openssh.com/txt/socks4.protocol + enum class error : int + { + // 0 is reserved for success value + // 1-256 -> reserved for error values from socks server (+1 from wire value). + rejected = 92, + identd_connection, + identd_user, + // Specific to application + bad_read = 257, + bad_write, + unexpected_version + }; + + /* boost::system::error_code is extended for easier compatibility with + boost::asio errors. If std::error_code is needed (with expect<T> for + instance), then upgrade to boost 1.65+ or use conversion code in + develop branch at boost/system/detail/std_interoperability.hpp */ + + //! \return boost::system::error_category for net::socks namespace + const boost::system::error_category& error_category() noexcept; + + //! \return net::socks::error as a boost::system::error_code. + inline boost::system::error_code make_error_code(error value) noexcept + { + return boost::system::error_code{int(value), socks::error_category()}; + } + + //! Client support for socks connect and resolve commands. + class client + { + boost::asio::ip::tcp::socket proxy_; + std::uint16_t buffer_size_; + std::uint8_t buffer_[1024]; + socks::version ver_; + + /*! + Only invoked after `*send(...)` function completes or fails. + `bool(error) == false` indicates success; `self.get()` is always + `this` and allows implementations to skip + `std::enable_shared_from_this<T>` (ASIO callbacks need shared_ptr). + The design saves space and reduces cycles (everything uses moves, + so no atomic operations are ever necessary). + + \param error when processing last command (if any). + \param self `shared_ptr<client>` handle to `this`. + */ + virtual void done(boost::system::error_code error, std::shared_ptr<client> self) = 0; + + public: + using stream_type = boost::asio::ip::tcp; + + // defined in cpp + struct write; + struct read; + struct completed; + + /*! + \param proxy ownership is passed into `this`. Does not have to be + in connected state. + \param ver socks version for the connection. + */ + explicit client(stream_type::socket&& proxy, socks::version ver); + + client(const client&) = delete; + virtual ~client(); + client& operator=(const client&) = delete; + + //! \return Ownership of socks client socket object. + stream_type::socket take_socket() + { + return stream_type::socket{std::move(proxy_)}; + } + + //! \return Socks version. + socks::version socks_version() const noexcept { return ver_; } + + //! \return Contents of internal buffer. + epee::span<const std::uint8_t> buffer() const noexcept + { + return {buffer_, buffer_size_}; + } + + //! \post `buffer.empty()`. + void clear_command() noexcept { buffer_size_ = 0; } + + //! Try to set `address` as remote connection request. + bool set_connect_command(const epee::net_utils::ipv4_network_address& address); + + //! Try to set `domain` + `port` as remote connection request. + bool set_connect_command(boost::string_ref domain, std::uint16_t port); + + //! Try to set `address` as remote Tor hidden service connection request. + bool set_connect_command(const net::tor_address& address); + + //! Try to set `domain` as remote DNS A record lookup request. + bool set_resolve_command(boost::string_ref domain); + + /*! + Asynchronously connect to `proxy_address` then issue command in + `buffer()`. The `done(...)` method will be invoked upon completion + with `self` and potential `error`s. + + \note Must use one of the `self->set_*_command` calls before using + this function. + + \param self ownership of object is given to function. + \param proxy_address of the socks server. + \return False if `self->buffer().empty()` (no command set). + */ + static bool connect_and_send(std::shared_ptr<client> self, const stream_type::endpoint& proxy_address); + + /*! + Assume existing connection to proxy server; asynchronously issue + command in `buffer()`. The `done(...)` method will be invoked + upon completion with `self` and potential `error`s. + + \note Must use one of the `self->set_*_command` calls before using + the function. + + \param self ownership of object is given to function. + \return False if `self->buffer().empty()` (no command set). + */ + static bool send(std::shared_ptr<client> self); + }; + + template<typename Handler> + class connect_client : public client + { + Handler handler_; + + virtual void done(boost::system::error_code error, std::shared_ptr<client>) override + { + handler_(error, take_socket()); + } + + public: + explicit connect_client(stream_type::socket&& proxy, socks::version ver, Handler&& handler) + : client(std::move(proxy), ver), handler_(std::move(handler)) + {} + + virtual ~connect_client() override {} + }; + + template<typename Handler> + inline std::shared_ptr<client> + make_connect_client(client::stream_type::socket&& proxy, socks::version ver, Handler handler) + { + return std::make_shared<connect_client<Handler>>(std::move(proxy), ver, std::move(handler)); + } +} // socks +} // net + +namespace boost +{ +namespace system +{ + template<> + struct is_error_code_enum<net::socks::error> + : true_type + {}; +} // system +} // boost |