mirror of
https://github.com/PurpleI2P/i2pd
synced 2024-11-05 15:11:13 +00:00
507 lines
14 KiB
C++
507 lines
14 KiB
C++
#include "SOCKS.h"
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#include "Identity.h"
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#include "NetDb.h"
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#include "Destination.h"
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#include "ClientContext.h"
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#include "I2PEndian.h"
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#include <cstring>
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#include <cassert>
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namespace i2p
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{
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namespace proxy
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{
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void SOCKSHandler::AsyncSockRead()
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{
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LogPrint(eLogDebug,"--- SOCKS async sock read");
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if(m_sock) {
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m_sock->async_receive(boost::asio::buffer(m_sock_buff, socks_buffer_size),
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std::bind(&SOCKSHandler::HandleSockRecv, this,
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std::placeholders::_1, std::placeholders::_2));
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} else {
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LogPrint(eLogError,"--- SOCKS no socket for read");
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}
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}
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void SOCKSHandler::Terminate() {
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CloseStream();
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CloseSock();
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delete this; // HACK: ew
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}
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boost::asio::const_buffers_1 SOCKSHandler::GenerateSOCKS5SelectAuth(SOCKSHandler::authMethods method)
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{
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response[0] = '\x05'; //Version
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response[1] = method; //Response code
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return boost::asio::const_buffers_1(response,2);
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}
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boost::asio::const_buffers_1 SOCKSHandler::GenerateSOCKS4Response(SOCKSHandler::errTypes error, uint32_t ip, uint16_t port)
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{
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assert(error >= SOCKS4_OK);
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assert(type == ADDR_IPV4);
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response[0] = '\x00'; //Version
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response[1] = error; //Response code
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htobe16buf(response+2,port); //Port
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htobe32buf(response+4,ip); //IP
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return boost::asio::const_buffers_1(response,8);
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}
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boost::asio::const_buffers_1 SOCKSHandler::GenerateSOCKS5Response(SOCKSHandler::errTypes error, SOCKSHandler::addrTypes type,
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const SOCKSHandler::address &addr, uint16_t port)
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{
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size_t size;
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assert(error <= SOCKS5_ADDR_UNSUP);
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response[0] = '\x05'; //Version
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response[1] = error; //Response code
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response[2] = '\x00'; //RSV
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response[3] = type; //Address type
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switch (type) {
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case ADDR_IPV4:
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size = 10;
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htobe32buf(response+4,addr.ip);
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break;
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case ADDR_IPV6:
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size = 22;
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memcpy(response+4,addr.ipv6, 16);
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break;
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case ADDR_DNS:
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size = 7+addr.dns.size;
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response[4] = addr.dns.size;
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memcpy(response+5,addr.dns.value, addr.dns.size);
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break;
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}
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htobe16buf(response+size-2,port); //Port
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return boost::asio::const_buffers_1(response,size);
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}
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/* Ah ah ah, you didn't say the magic word */
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void SOCKSHandler::Socks5AuthNegoFailed()
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{
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LogPrint(eLogWarning,"--- SOCKS5 authentication negotiation failed");
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boost::asio::async_write(*m_sock, GenerateSOCKS5SelectAuth(AUTH_UNACCEPTABLE),
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std::bind(&SOCKSHandler::SentSocksFailed, this, std::placeholders::_1));
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}
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void SOCKSHandler::Socks5ChooseAuth()
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{
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LogPrint(eLogDebug,"--- SOCKS5 choosing authentication method: ", m_authchosen);
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boost::asio::async_write(*m_sock, GenerateSOCKS5SelectAuth(m_authchosen),
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std::bind(&SOCKSHandler::SentSocksResponse, this, std::placeholders::_1));
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}
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/* All hope is lost beyond this point */
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void SOCKSHandler::SocksRequestFailed(SOCKSHandler::errTypes error)
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{
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boost::asio::const_buffers_1 response(nullptr,0);
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assert(error != SOCKS4_OK && error != SOCKS5_OK);
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switch (m_socksv) {
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case SOCKS4:
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LogPrint(eLogWarning,"--- SOCKS4 failed: ", error);
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if (error < SOCKS4_OK) error = SOCKS4_FAIL; //Transparently map SOCKS5 errors
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response = GenerateSOCKS4Response(error, m_4aip, m_port);
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break;
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case SOCKS5:
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LogPrint(eLogWarning,"--- SOCKS5 failed: ", error);
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response = GenerateSOCKS5Response(error, m_addrtype, m_address, m_port);
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break;
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}
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boost::asio::async_write(*m_sock, response, std::bind(&SOCKSHandler::SentSocksFailed, this, std::placeholders::_1));
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}
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void SOCKSHandler::SocksRequestSuccess()
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{
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boost::asio::const_buffers_1 response(nullptr,0);
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//TODO: this should depend on things like the command type and callbacks may change
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switch (m_socksv) {
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case SOCKS4:
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LogPrint(eLogInfo,"--- SOCKS4 connection success");
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response = GenerateSOCKS4Response(SOCKS4_OK, m_4aip, m_port);
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break;
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case SOCKS5:
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LogPrint(eLogInfo,"--- SOCKS5 connection success");
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auto s = i2p::client::context.GetAddressBook().ToAddress(m_parent->GetLocalDestination()->GetIdentHash());
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address ad; ad.dns.FromString(s);
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//HACK only 16 bits passed in port as SOCKS5 doesn't allow for more
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response = GenerateSOCKS5Response(SOCKS5_OK, ADDR_DNS, ad, m_stream->GetSendStreamID());
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break;
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}
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boost::asio::async_write(*m_sock, response, std::bind(&SOCKSHandler::SentSocksResponse, this, std::placeholders::_1));
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}
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void SOCKSHandler::CloseSock()
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{
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if (m_sock) {
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LogPrint(eLogDebug,"--- SOCKS close sock");
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m_sock->close();
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delete m_sock;
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m_sock = nullptr;
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}
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}
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void SOCKSHandler::CloseStream()
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{
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if (m_stream) {
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LogPrint(eLogDebug,"--- SOCKS close stream");
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m_stream.reset ();
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}
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}
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std::size_t SOCKSHandler::HandleData(uint8_t *sock_buff, std::size_t len)
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{
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assert(len); // This should always be called with a least a byte left to parse
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switch (m_state) {
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case GET_VERSION:
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return HandleVersion(sock_buff);
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case SOCKS5_AUTHNEGO:
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return HandleSOCKS5AuthNego(sock_buff,len);
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case SOCKS_REQUEST:
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return HandleSOCKSRequest(sock_buff,len);
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default:
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LogPrint(eLogError,"--- SOCKS state?? ", m_state);
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Terminate();
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return 0;
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}
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}
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std::size_t SOCKSHandler::HandleVersion(uint8_t *sock_buff)
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{
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switch (*sock_buff) {
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case SOCKS4:
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m_state = SOCKS_REQUEST; // Switch to the 4 handler
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m_pstate = GET_COMMAND; //Initialize the parser at the right position
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break;
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case SOCKS5:
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m_state = SOCKS5_AUTHNEGO; // Switch to the 5 handler
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m_pstate = GET5_AUTHNUM; //Initialize the parser at the right position
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break;
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default:
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LogPrint(eLogError,"--- SOCKS rejected invalid version: ", ((int)*sock_buff));
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Terminate();
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return 0;
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}
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m_socksv = (SOCKSHandler::socksVersions) *sock_buff;
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return 1;
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}
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std::size_t SOCKSHandler::HandleSOCKS5AuthNego(uint8_t *sock_buff, std::size_t len)
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{
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std::size_t rv = 0;
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while (len > 0) {
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rv++;
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switch (m_pstate)
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{
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case GET5_AUTHNUM:
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m_parseleft = *sock_buff;
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m_pstate = GET5_AUTH;
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break;
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case GET5_AUTH:
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m_parseleft --;
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if (*sock_buff == AUTH_NONE)
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m_authchosen = AUTH_NONE;
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if ( m_parseleft == 0 ) {
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if (m_authchosen == AUTH_UNACCEPTABLE) {
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//TODO: we maybe want support for other methods!
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LogPrint(eLogError,"--- SOCKS5 couldn't negotiate authentication");
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Socks5AuthNegoFailed();
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return 0;
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}
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m_pstate = GET5_REQUESTV;
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m_state = SOCKS_REQUEST;
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m_need_more = false;
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Socks5ChooseAuth();
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return rv;
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}
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break;
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default:
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LogPrint(eLogError,"--- SOCKS5 parse state?? ", m_pstate);
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Terminate();
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return 0;
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}
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sock_buff++;
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len--;
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}
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return rv;
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}
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bool SOCKSHandler::ValidateSOCKSRequest() {
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if ( m_cmd != CMD_CONNECT ) {
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//TODO: we need to support binds and other shit!
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LogPrint(eLogError,"--- SOCKS unsupported command: ", m_cmd);
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SocksRequestFailed(SOCKS5_CMD_UNSUP);
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return false;
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}
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//TODO: we may want to support other address types!
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if ( m_addrtype != ADDR_DNS ) {
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switch (m_socksv) {
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case SOCKS5:
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LogPrint(eLogError,"--- SOCKS5 unsupported address type: ", m_addrtype);
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break;
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case SOCKS4:
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LogPrint(eLogError,"--- SOCKS4a rejected because it's actually SOCKS4");
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break;
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}
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SocksRequestFailed(SOCKS5_ADDR_UNSUP);
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return false;
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}
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//TODO: we may want to support other domains
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if(m_addrtype == ADDR_DNS && m_address.dns.ToString().find(".i2p") == std::string::npos) {
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LogPrint(eLogError,"--- SOCKS invalid hostname: ", m_address.dns.ToString());
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SocksRequestFailed(SOCKS5_ADDR_UNSUP);
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return false;
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}
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return true;
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}
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std::size_t SOCKSHandler::HandleSOCKSRequest(uint8_t *sock_buff, std::size_t len)
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{
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std::size_t rv = 0;
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while (len > 0) {
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rv++;
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switch (m_pstate)
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{
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case GET_COMMAND:
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switch (*sock_buff) {
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case CMD_CONNECT:
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case CMD_BIND:
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break;
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case CMD_UDP:
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if (m_socksv == SOCKS5) break;
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default:
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LogPrint(eLogError,"--- SOCKS invalid command: ", ((int)*sock_buff));
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SocksRequestFailed(SOCKS5_GEN_FAIL);
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return 0;
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}
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m_cmd = (SOCKSHandler::cmdTypes)*sock_buff;
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switch (m_socksv) {
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case SOCKS5: m_pstate = GET5_GETRSV; break;
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case SOCKS4: m_pstate = GET_PORT; m_parseleft = 2; break;
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}
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break;
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case GET_PORT:
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m_port = (m_port << 8)|((uint16_t)*sock_buff);
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m_parseleft--;
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if (m_parseleft == 0) {
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switch (m_socksv) {
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case SOCKS5: m_pstate = DONE; break;
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case SOCKS4: m_pstate = GET_IPV4; m_address.ip = 0; m_parseleft = 4; break;
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}
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}
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break;
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case GET_IPV4:
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m_address.ip = (m_address.ip << 8)|((uint32_t)*sock_buff);
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m_parseleft--;
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if (m_parseleft == 0) {
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switch (m_socksv) {
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case SOCKS5: m_pstate = GET_PORT; m_parseleft = 2; break;
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case SOCKS4: m_pstate = GET4_IDENT; m_4aip = m_address.ip; break;
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}
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}
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break;
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case GET4_IDENT:
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if (!*sock_buff) {
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if( m_4aip == 0 || m_4aip > 255 ) {
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m_addrtype = ADDR_IPV4;
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m_pstate = DONE;
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} else {
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m_addrtype = ADDR_DNS;
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m_pstate = GET4A_HOST;
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m_address.dns.size = 0;
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}
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}
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break;
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case GET4A_HOST:
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if (!*sock_buff) {
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m_pstate = DONE;
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break;
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}
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if (m_address.dns.size >= max_socks_hostname_size) {
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LogPrint(eLogError,"--- SOCKS4a destination is too large");
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SocksRequestFailed(SOCKS4_FAIL);
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return 0;
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}
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m_address.dns.push_back(*sock_buff);
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break;
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case GET5_REQUESTV:
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if (*sock_buff != SOCKS5) {
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LogPrint(eLogError,"--- SOCKS5 rejected unknown request version: ", ((int)*sock_buff));
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SocksRequestFailed(SOCKS5_GEN_FAIL);
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return 0;
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}
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m_pstate = GET_COMMAND;
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break;
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case GET5_GETRSV:
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if ( *sock_buff != 0 ) {
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LogPrint(eLogError,"--- SOCKS5 unknown reserved field: ", ((int)*sock_buff));
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SocksRequestFailed(SOCKS5_GEN_FAIL);
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return 0;
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}
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m_pstate = GET5_GETADDRTYPE;
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break;
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case GET5_GETADDRTYPE:
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switch (*sock_buff) {
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case ADDR_IPV4: m_pstate = GET_IPV4; m_address.ip = 0; m_parseleft = 4; break;
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case ADDR_IPV6: m_pstate = GET5_IPV6; m_parseleft = 16; break;
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case ADDR_DNS : m_pstate = GET5_HOST_SIZE; break;
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default:
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LogPrint(eLogError,"--- SOCKS5 unknown address type: ", ((int)*sock_buff));
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SocksRequestFailed(SOCKS5_GEN_FAIL);
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return 0;
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}
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m_addrtype = (SOCKSHandler::addrTypes)*sock_buff;
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break;
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case GET5_IPV6:
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m_address.ipv6[16-m_parseleft] = *sock_buff;
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m_parseleft--;
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if (m_parseleft == 0) {
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m_pstate = GET_PORT;
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m_parseleft = 2;
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}
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break;
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case GET5_HOST_SIZE:
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m_parseleft = *sock_buff;
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m_address.dns.size = 0;
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m_pstate = GET5_HOST;
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break;
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case GET5_HOST:
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m_address.dns.push_back(*sock_buff);
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m_parseleft--;
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if (m_parseleft == 0) {
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m_pstate = GET_PORT;
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m_parseleft = 2;
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}
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break;
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default:
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LogPrint(eLogError,"--- SOCKS parse state?? ", m_pstate);
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Terminate();
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return 0;
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}
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if (m_pstate == DONE) {
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m_state = READY;
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m_need_more = false;
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return (ValidateSOCKSRequest() ? rv : 0);
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}
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sock_buff++;
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len--;
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}
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return rv;
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}
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void SOCKSHandler::HandleSockRecv(const boost::system::error_code & ecode, std::size_t len)
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{
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LogPrint(eLogDebug,"--- SOCKS sock recv: ", len);
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if(ecode) {
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LogPrint(eLogWarning," --- SOCKS sock recv got error: ", ecode);
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Terminate();
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return;
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}
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std::size_t pos = 0;
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m_need_more = true;
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while (pos != len && m_state != READY && m_need_more) {
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assert(pos < len); //We are overflowing the buffer otherwise
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std::size_t rv = HandleData(m_sock_buff + pos, len - pos);
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if (!rv) return; //Something went wrong die misserably
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pos += rv;
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}
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assert(!(m_state == READY && m_need_more));
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if (m_state == READY) {
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LogPrint(eLogInfo,"--- SOCKS requested ", m_address.dns.ToString(), ":" , m_port);
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if (pos != len) {
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LogPrint(eLogError,"--- SOCKS rejected because we can't handle extra data");
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SocksRequestFailed(SOCKS5_GEN_FAIL);
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return ;
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}
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m_parent->GetLocalDestination ()->CreateStream (
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std::bind (&SOCKSHandler::HandleStreamRequestComplete,
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this, std::placeholders::_1), m_address.dns.ToString(), m_port);
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} else if (m_need_more) {
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LogPrint (eLogDebug,"--- SOCKS Need more data");
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AsyncSockRead();
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}
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}
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void SOCKSHandler::SentSocksFailed(const boost::system::error_code & ecode)
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{
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if (!ecode) {
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Terminate();
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} else {
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LogPrint (eLogError,"--- SOCKS Closing socket after sending failure because: ", ecode.message ());
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Terminate();
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}
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}
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void SOCKSHandler::SentSocksResponse(const boost::system::error_code & ecode)
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{
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if (!ecode) {
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if(m_state == READY) {
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LogPrint (eLogInfo,"--- SOCKS New I2PTunnel connection");
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auto connection = std::make_shared<i2p::client::I2PTunnelConnection>((i2p::client::I2PTunnel *)m_parent, m_sock, m_stream);
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m_parent->AddConnection (connection);
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connection->I2PConnect ();
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} else {
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LogPrint (eLogDebug,"--- SOCKS Go to next state");
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AsyncSockRead();
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}
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}
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else
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{
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LogPrint (eLogError,"--- SOCKS Closing socket after sending reply because: ", ecode.message ());
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Terminate();
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}
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}
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void SOCKSHandler::HandleStreamRequestComplete (std::shared_ptr<i2p::stream::Stream> stream)
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{
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if (stream) {
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//TODO: test the stream is open if it isn't fail with connrefused
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m_stream = stream;
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SocksRequestSuccess();
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} else {
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LogPrint (eLogError,"--- SOCKS Issue when creating the stream, check the previous warnings for more info.");
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SocksRequestFailed(SOCKS5_HOST_UNREACH);
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}
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}
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void SOCKSServer::Start ()
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{
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m_Acceptor.listen ();
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Accept ();
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}
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void SOCKSServer::Stop ()
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{
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m_Acceptor.close();
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m_Timer.cancel ();
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ClearConnections ();
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}
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void SOCKSServer::Accept ()
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{
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auto newSocket = new boost::asio::ip::tcp::socket (GetService ());
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m_Acceptor.async_accept (*newSocket, std::bind (&SOCKSServer::HandleAccept, this,
|
|
std::placeholders::_1, newSocket));
|
|
}
|
|
|
|
void SOCKSServer::HandleAccept (const boost::system::error_code& ecode, boost::asio::ip::tcp::socket * socket)
|
|
{
|
|
if (!ecode)
|
|
{
|
|
LogPrint(eLogDebug,"--- SOCKS accepted");
|
|
new SOCKSHandler(this, socket);
|
|
Accept();
|
|
}
|
|
else
|
|
{
|
|
LogPrint (eLogError,"--- SOCKS Closing socket on accept because: ", ecode.message ());
|
|
delete socket;
|
|
}
|
|
}
|
|
|
|
}
|
|
}
|