#ifndef SOCKS_H__ #define SOCKS_H__ #include #include #include #include "Identity.h" #include "Streaming.h" #include "I2PTunnel.h" namespace i2p { namespace proxy { const size_t socks_buffer_size = 8192; const size_t max_socks_hostname_size = 255; // Limit for socks5 and bad idea to traverse struct SOCKSDnsAddress { uint8_t size; char value[max_socks_hostname_size]; void FromString (std::string str) { size = str.length(); if (str.length() > max_socks_hostname_size) size = max_socks_hostname_size; memcpy(value,str.c_str(),size); } std::string ToString() { return std::string(value, size); } void push_back (char c) { value[size++] = c; } }; class SOCKSServer; class SOCKSHandler { private: enum state { GET_VERSION, // Get SOCKS version SOCKS5_AUTHNEGO, //Authentication negotiation SOCKS5_AUTH, //Authentication SOCKS_REQUEST, //Request READY // Ready to connect }; enum parseState { GET_COMMAND, GET_PORT, GET_IPV4, GET4_IDENT, GET4A_HOST, GET5_AUTHNUM, GET5_AUTH, GET5_REQUESTV, GET5_GETRSV, GET5_GETADDRTYPE, GET5_IPV6, GET5_HOST_SIZE, GET5_HOST, DONE }; enum authMethods { AUTH_NONE = 0, //No authentication, skip to next step AUTH_GSSAPI = 1, //GSSAPI authentication AUTH_USERPASSWD = 2, //Username and password AUTH_UNACCEPTABLE = 0xff //No acceptable method found }; enum addrTypes { ADDR_IPV4 = 1, //IPv4 address (4 octets) ADDR_DNS = 3, // DNS name (up to 255 octets) ADDR_IPV6 = 4 //IPV6 address (16 octets) }; enum errTypes { SOCKS5_OK = 0, // No error for SOCKS5 SOCKS5_GEN_FAIL = 1, // General server failure SOCKS5_RULE_DENIED = 2, // Connection disallowed by ruleset SOCKS5_NET_UNREACH = 3, // Network unreachable SOCKS5_HOST_UNREACH = 4, // Host unreachable SOCKS5_CONN_REFUSED = 5, // Connection refused by the peer SOCKS5_TTL_EXPIRED = 6, // TTL Expired SOCKS5_CMD_UNSUP = 7, // Command unsuported SOCKS5_ADDR_UNSUP = 8, // Address type unsuported SOCKS4_OK = 90, // No error for SOCKS4 SOCKS4_FAIL = 91, // Failed establishing connecting or not allowed SOCKS4_IDENTD_MISSING = 92, // Couldn't connect to the identd server SOCKS4_IDENTD_DIFFER = 93 // The ID reported by the application and by identd differ }; enum cmdTypes { CMD_CONNECT = 1, // TCP Connect CMD_BIND = 2, // TCP Bind CMD_UDP = 3 // UDP associate }; enum socksVersions { SOCKS4 = 4, // SOCKS4 SOCKS5 = 5 // SOCKS5 }; union address { uint32_t ip; SOCKSDnsAddress dns; uint8_t ipv6[16]; }; std::size_t HandleData(uint8_t *sock_buff, std::size_t len); std::size_t HandleVersion(uint8_t *sock_buff); std::size_t HandleSOCKS5AuthNego(uint8_t *sock_buff, std::size_t len); std::size_t HandleSOCKSRequest(uint8_t *sock_buff, std::size_t len); bool ValidateSOCKSRequest(); void HandleSockRecv(const boost::system::error_code & ecode, std::size_t bytes_transfered); void Terminate(); void CloseSock(); void CloseStream(); void AsyncSockRead(); boost::asio::const_buffers_1 GenerateSOCKS5SelectAuth(authMethods method); boost::asio::const_buffers_1 GenerateSOCKS4Response(errTypes error, uint32_t ip, uint16_t port); boost::asio::const_buffers_1 GenerateSOCKS5Response(errTypes error, addrTypes type, const address &addr, uint16_t port); void Socks5AuthNegoFailed(); void Socks5ChooseAuth(); void SocksRequestFailed(errTypes error); void SocksRequestSuccess(); //HACK: we need to pass the shared_ptr to ensure the buffer will live enough void SentSocksFailed(const boost::system::error_code & ecode); void SentSocksResponse(const boost::system::error_code & ecode); void HandleStreamRequestComplete (std::shared_ptr stream); uint8_t m_sock_buff[socks_buffer_size]; SOCKSServer * m_parent; boost::asio::ip::tcp::socket * m_sock; std::shared_ptr m_stream; state m_state; parseState m_pstate; uint8_t m_command; uint16_t m_port; uint32_t m_4aip; //Used in 4a requests uint8_t m_authleft; //Authentication methods left //TODO: this will probably be more elegant as enums authMethods m_authchosen; //Authentication chosen addrTypes m_addrtype; //Address type chosen address m_address; //Address uint8_t m_addrleft; //Octets of current address left socksVersions m_socksv; //Socks version cmdTypes m_cmd; // Command requested bool m_need_more; //The parser still needs to receive more data uint8_t response[7+max_socks_hostname_size]; public: SOCKSHandler(SOCKSServer * parent, boost::asio::ip::tcp::socket * sock) : m_parent(parent), m_sock(sock), m_stream(nullptr), m_state(GET_VERSION), m_authchosen(AUTH_UNACCEPTABLE), m_addrtype(ADDR_IPV4) { m_address.ip = 0; AsyncSockRead(); } ~SOCKSHandler() { CloseSock(); CloseStream(); } }; class SOCKSServer: public i2p::client::I2PTunnel { public: SOCKSServer(int port) : I2PTunnel(nullptr), m_Acceptor (GetService (), boost::asio::ip::tcp::endpoint (boost::asio::ip::tcp::v4(), port)), m_Timer (GetService ()) {}; ~SOCKSServer() { Stop(); } void Start (); void Stop (); private: void Accept(); void HandleAccept(const boost::system::error_code& ecode, boost::asio::ip::tcp::socket * socket); private: boost::asio::ip::tcp::acceptor m_Acceptor; boost::asio::deadline_timer m_Timer; }; typedef SOCKSServer SOCKSProxy; } } #endif