I2P: End-to-End encrypted and anonymous Internet https://i2pd.website/
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 

480 lines
13 KiB

#include "SOCKS.h"
#include "Identity.h"
#include "NetDb.h"
#include "Destination.h"
#include "ClientContext.h"
#include "I2PEndian.h"
#include <cassert>
namespace i2p
{
namespace proxy
{
void SOCKSHandler::AsyncSockRead()
{
LogPrint(eLogDebug,"--- SOCKS async sock read");
if(m_sock) {
m_sock->async_receive(boost::asio::buffer(m_sock_buff, socks_buffer_size),
std::bind(&SOCKSHandler::HandleSockRecv, this,
std::placeholders::_1, std::placeholders::_2));
} else {
LogPrint(eLogError,"--- SOCKS no socket for read");
}
}
void SOCKSHandler::Terminate() {
CloseStream();
CloseSock();
delete this; // HACK: ew
}
void SOCKSHandler::Socks5AuthNegoFailed()
{
LogPrint(eLogWarning,"--- SOCKS5 authentication negotiation failed");
boost::asio::async_write(*m_sock, boost::asio::buffer("\x05\xff",2),
std::bind(&SOCKSHandler::SentSocksFailed, this,
std::placeholders::_1));
}
void SOCKSHandler::Socks5ChooseAuth()
{
LogPrint(eLogDebug,"--- SOCKS5 choosing authentication method");
//TODO: Choose right method
boost::asio::async_write(*m_sock, boost::asio::buffer("\x05\x00",2),
std::bind(&SOCKSHandler::SentSocksResponse, this,
std::placeholders::_1, nullptr));
}
static const char *socks5Replies[9] = {
"\x05\x00\x00\x01\x00\x00\x00\x00\x00\x00",
"\x05\x01\x00\x01\x00\x00\x00\x00\x00\x00",
"\x05\x02\x00\x01\x00\x00\x00\x00\x00\x00",
"\x05\x03\x00\x01\x00\x00\x00\x00\x00\x00",
"\x05\x04\x00\x01\x00\x00\x00\x00\x00\x00",
"\x05\x05\x00\x01\x00\x00\x00\x00\x00\x00",
"\x05\x06\x00\x01\x00\x00\x00\x00\x00\x00",
"\x05\x07\x00\x01\x00\x00\x00\x00\x00\x00",
"\x05\x08\x00\x01\x00\x00\x00\x00\x00\x00" };
/* All hope is lost */
void SOCKSHandler::SocksRequestFailed()
{
switch (m_socksv) {
case SOCKS4:
LogPrint(eLogWarning,"--- SOCKS4 failed");
//TODO: send the right response
boost::asio::async_write(*m_sock, boost::asio::buffer("\x00\x5b\x00\x00\x00\x00\x00\x00",8),
std::bind(&SOCKSHandler::SentSocksFailed, this, std::placeholders::_1));
break;
case SOCKS5:
assert(m_error <= SOCKS5_ADDR_UNSUP);
LogPrint(eLogWarning,"--- SOCKS5 failed");
//TODO: use error properly and address type m_error
boost::asio::async_write(*m_sock, boost::asio::buffer(socks5Replies[m_error],10),
std::bind(&SOCKSHandler::SentSocksFailed, this, std::placeholders::_1));
break;
}
}
void SOCKSHandler::SocksRequestSuccess()
{
std::shared_ptr<std::vector<uint8_t>> response(new std::vector<uint8_t>);
switch (m_socksv) {
case SOCKS4:
LogPrint(eLogInfo,"--- SOCKS4 connection success");
//TODO: send the right response
boost::asio::async_write(*m_sock, boost::asio::buffer("\x00\x5a\x00\x00\x00\x00\x00\x00",8),
std::bind(&SOCKSHandler::SentSocksResponse, this,
std::placeholders::_1, nullptr));
break;
case SOCKS5:
LogPrint(eLogInfo,"--- SOCKS5 connection success");
//TODO: send the right response using the port? and the localside i2p address
boost::asio::async_write(*m_sock, boost::asio::buffer("\x05\x00\x00\x01\x00\x00\x00\x00\x00\x00",10),
std::bind(&SOCKSHandler::SentSocksResponse, this,
std::placeholders::_1, response));
break;
}
}
void SOCKSHandler::CloseSock()
{
if (m_sock) {
LogPrint(eLogDebug,"--- SOCKS close sock");
m_sock->close();
delete m_sock;
m_sock = nullptr;
}
}
void SOCKSHandler::CloseStream()
{
if (m_stream) {
LogPrint(eLogDebug,"--- SOCKS close stream");
m_stream.reset ();
}
}
std::size_t SOCKSHandler::HandleData(uint8_t *sock_buff, std::size_t len)
{
assert(len); // This should always be called with a least a byte left to parse
switch (m_state) {
case GET_VERSION:
return HandleVersion(sock_buff);
case SOCKS5_AUTHNEGO:
return HandleSOCKS5AuthNego(sock_buff,len);
case SOCKS_REQUEST:
return HandleSOCKSRequest(sock_buff,len);
default:
LogPrint(eLogError,"--- SOCKS state?? ", m_state);
Terminate();
return 0;
}
}
std::size_t SOCKSHandler::HandleVersion(uint8_t *sock_buff)
{
switch (*sock_buff) {
case SOCKS4:
m_state = SOCKS_REQUEST; // Switch to the 4 handler
m_pstate = GET_COMMAND; //Initialize the parser at the right position
break;
case SOCKS5:
m_state = SOCKS5_AUTHNEGO; // Switch to the 5 handler
m_pstate = GET5_AUTHNUM; //Initialize the parser at the right position
break;
default:
LogPrint(eLogError,"--- SOCKS rejected invalid version: ", ((int)*sock_buff));
Terminate();
return 0;
}
m_socksv = (SOCKSHandler::socksVersions) *sock_buff;
return 1;
}
std::size_t SOCKSHandler::HandleSOCKS5AuthNego(uint8_t *sock_buff, std::size_t len)
{
std::size_t rv = 0;
while (len > 0) {
rv++;
switch (m_pstate)
{
case GET5_AUTHNUM:
m_authleft = *sock_buff;
m_pstate = GET5_AUTH;
break;
case GET5_AUTH:
m_authleft --;
if (*sock_buff == AUTH_NONE)
m_authchosen = AUTH_NONE;
if ( m_authleft == 0 ) {
if (m_authchosen == AUTH_UNACCEPTABLE) {
//TODO: we maybe want support for other methods!
LogPrint(eLogError,"--- SOCKS5 couldn't negotiate authentication");
Socks5AuthNegoFailed();
return 0;
}
m_pstate = GET5_REQUESTV;
m_state = SOCKS_REQUEST;
m_need_more = false;
Socks5ChooseAuth();
return rv;
}
break;
default:
LogPrint(eLogError,"--- SOCKS5 parse state?? ", m_pstate);
Terminate();
return 0;
}
sock_buff++;
len--;
}
return rv;
}
bool SOCKSHandler::ValidateSOCKSRequest() {
if ( m_cmd != CMD_CONNECT ) {
//TODO: we need to support binds and other shit!
LogPrint(eLogError,"--- SOCKS unsupported command: ", m_cmd);
m_error = SOCKS5_CMD_UNSUP;
SocksRequestFailed();
return false;
}
//TODO: we may want to support other address types!
if ( m_addrtype != ADDR_DNS ) {
switch (m_socksv) {
case SOCKS5:
LogPrint(eLogError,"--- SOCKS5 unsupported address type: ", m_addrtype);
m_error = SOCKS5_ADDR_UNSUP;
break;
case SOCKS4:
LogPrint(eLogError,"--- SOCKS4a rejected because it's actually SOCKS4");
break;
}
SocksRequestFailed();
return false;
}
//TODO: we may want to support other domains
if(m_addrtype == ADDR_DNS && m_destination.find(".i2p") == std::string::npos) {
LogPrint(eLogError,"--- SOCKS invalid hostname: ", m_destination);
m_error = SOCKS5_ADDR_UNSUP;
SocksRequestFailed();
return false;
}
return true;
}
std::size_t SOCKSHandler::HandleSOCKSRequest(uint8_t *sock_buff, std::size_t len)
{
std::size_t rv = 0;
while (len > 0) {
rv++;
switch (m_pstate)
{
case GET_COMMAND:
switch (*sock_buff) {
case CMD_CONNECT:
case CMD_BIND:
break;
case CMD_UDP:
if (m_socksv == SOCKS5) break;
default:
LogPrint(eLogError,"--- SOCKS invalid command: ", ((int)*sock_buff));
m_error = SOCKS5_GEN_FAIL;
SocksRequestFailed();
return 0;
}
m_cmd = (SOCKSHandler::cmdTypes)*sock_buff;
switch (m_socksv) {
case SOCKS5: m_pstate = GET5_GETRSV; break;
case SOCKS4: m_pstate = GET_PORT; m_addrleft = 2; break;
}
break;
case GET_PORT:
m_port = (m_port << 8)|((uint16_t)*sock_buff);
m_addrleft--;
if (m_addrleft == 0) {
switch (m_socksv) {
case SOCKS5: m_pstate = DONE; break;
case SOCKS4: m_pstate = GET_IPV4; m_addrleft = 4; break;
}
}
break;
case GET_IPV4:
m_ip = (m_ip << 8)|((uint32_t)*sock_buff);
m_addrleft--;
if (m_addrleft == 0) {
switch (m_socksv) {
case SOCKS5: m_pstate = GET_PORT; m_addrleft = 2; break;
case SOCKS4: m_pstate = GET4_IDENT; break;
}
}
break;
case GET4_IDENT:
if (!*sock_buff) {
if( m_ip == 0 || m_ip > 255 ) {
m_addrtype = ADDR_IPV4;
m_pstate = DONE;
} else {
m_addrtype = ADDR_DNS;
m_pstate = GET4A_HOST;
}
}
break;
case GET4A_HOST:
if (!*sock_buff) {
m_pstate = DONE;
break;
}
if (m_destination.size() > max_socks_hostname_size) {
LogPrint(eLogError,"--- SOCKS4a destination is too large");
SocksRequestFailed();
return 0;
}
m_destination.push_back(*sock_buff);
break;
case GET5_REQUESTV:
if (*sock_buff != SOCKS5) {
LogPrint(eLogError,"--- SOCKS5 rejected unknown request version: ", ((int)*sock_buff));
m_error = SOCKS5_GEN_FAIL;
SocksRequestFailed();
return 0;
}
m_pstate = GET_COMMAND;
break;
case GET5_GETRSV:
if ( *sock_buff != 0 ) {
LogPrint(eLogError,"--- SOCKS5 unknown reserved field: ", ((int)*sock_buff));
m_error = SOCKS5_GEN_FAIL;
SocksRequestFailed();
return 0;
}
m_pstate = GET5_GETADDRTYPE;
break;
case GET5_GETADDRTYPE:
switch (*sock_buff) {
case ADDR_IPV4: m_pstate = GET_IPV4; m_addrleft = 4; break;
case ADDR_IPV6: m_pstate = GET5_IPV6; m_addrleft = 16; break;
case ADDR_DNS : m_pstate = GET5_HOST_SIZE; break;
default:
LogPrint(eLogError,"--- SOCKS5 unknown address type: ", ((int)*sock_buff));
m_error = SOCKS5_GEN_FAIL;
SocksRequestFailed();
return 0;
}
m_addrtype = (SOCKSHandler::addrTypes)*sock_buff;
break;
case GET5_IPV6:
m_ipv6[16-m_addrleft] = *sock_buff;
m_addrleft--;
if (m_addrleft == 0) {
m_pstate = GET_PORT;
m_addrleft = 2;
}
break;
case GET5_HOST_SIZE:
m_addrleft = *sock_buff;
m_pstate = GET5_HOST;
break;
case GET5_HOST:
m_destination.push_back(*sock_buff);
m_addrleft--;
if (m_addrleft == 0) {
m_pstate = GET_PORT;
m_addrleft = 2;
}
break;
default:
LogPrint(eLogError,"--- SOCKS parse state?? ", m_pstate);
Terminate();
return 0;
}
if (m_pstate == DONE) {
m_state = READY;
m_need_more = false;
return (ValidateSOCKSRequest() ? rv : 0);
}
sock_buff++;
len--;
}
return rv;
}
void SOCKSHandler::HandleSockRecv(const boost::system::error_code & ecode, std::size_t len)
{
LogPrint(eLogDebug,"--- SOCKS sock recv: ", len);
if(ecode) {
LogPrint(eLogWarning," --- SOCKS sock recv got error: ", ecode);
Terminate();
return;
}
std::size_t pos = 0;
m_need_more = true;
while (pos != len && m_state != READY && m_need_more) {
assert(pos < len); //We are overflowing the buffer otherwise
std::size_t rv = HandleData(m_sock_buff + pos, len - pos);
if (!rv) return; //Something went wrong die misserably
pos += rv;
}
assert(!(m_state == READY && m_need_more));
if (m_state == READY) {
LogPrint(eLogInfo,"--- SOCKS requested ", m_destination, ":" , m_port);
if (pos != len) {
LogPrint(eLogError,"--- SOCKS rejected because we can't handle extra data");
SocksRequestFailed();
return ;
}
m_parent->GetLocalDestination ()->CreateStream (
std::bind (&SOCKSHandler::HandleStreamRequestComplete,
this, std::placeholders::_1), m_destination, m_port);
} else if (m_need_more) {
LogPrint (eLogDebug,"--- SOCKS Need more data");
AsyncSockRead();
}
}
void SOCKSHandler::SentSocksFailed(const boost::system::error_code & ecode)
{
if (!ecode) {
Terminate();
} else {
LogPrint (eLogError,"--- SOCKS Closing socket after sending failure because: ", ecode.message ());
Terminate();
}
}
void SOCKSHandler::SentSocksResponse(const boost::system::error_code & ecode, std::shared_ptr<std::vector<uint8_t>> response)
{
response.reset(); // Information wants to be free, so does memory
if (!ecode) {
if(m_state == READY) {
LogPrint (eLogInfo,"--- SOCKS New I2PTunnel connection");
auto connection = std::make_shared<i2p::client::I2PTunnelConnection>((i2p::client::I2PTunnel *)m_parent, m_sock, m_stream);
m_parent->AddConnection (connection);
connection->I2PConnect ();
} else {
LogPrint (eLogDebug,"--- SOCKS Go to next state");
AsyncSockRead();
}
}
else
{
LogPrint (eLogError,"--- SOCKS Closing socket after sending reply because: ", ecode.message ());
Terminate();
}
}
void SOCKSHandler::HandleStreamRequestComplete (std::shared_ptr<i2p::stream::Stream> stream)
{
if (stream) {
m_stream = stream;
SocksRequestSuccess();
} else {
m_error = SOCKS5_HOST_UNREACH;
LogPrint (eLogError,"--- SOCKS Issue when creating the stream, check the previous warnings for more info.");
SocksRequestFailed();
}
}
void SOCKSServer::Start ()
{
m_Acceptor.listen ();
Accept ();
}
void SOCKSServer::Stop ()
{
m_Acceptor.close();
m_Timer.cancel ();
ClearConnections ();
}
void SOCKSServer::Accept ()
{
auto newSocket = new boost::asio::ip::tcp::socket (GetService ());
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;
}
}
}
}