I2P: End-to-End encrypted and anonymous Internet https://i2pd.website/
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#ifndef SOCKS_H__
#define SOCKS_H__
#include <memory>
#include <string>
#include <set>
#include <boost/asio.hpp>
#include <mutex>
#include <atomic>
#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: public std::enable_shared_from_this<SOCKSHandler> {
private:
enum state {
GET_SOCKSV,
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];
};
void EnterState(state nstate, uint8_t parseleft = 1);
bool HandleData(uint8_t *sock_buff, std::size_t len);
bool ValidateSOCKSRequest();
void HandleSockRecv(const boost::system::error_code & ecode, std::size_t bytes_transfered);
void Done();
void Terminate();
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);
bool Socks5ChooseAuth();
void SocksRequestFailed(errTypes error);
void SocksRequestSuccess();
void SentSocksFailed(const boost::system::error_code & ecode);
void SentSocksDone(const boost::system::error_code & ecode);
void SentSocksResponse(const boost::system::error_code & ecode);
void HandleStreamRequestComplete (std::shared_ptr<i2p::stream::Stream> stream);
uint8_t m_sock_buff[socks_buffer_size];
SOCKSServer * m_parent;
boost::asio::ip::tcp::socket * m_sock;
std::shared_ptr<i2p::stream::Stream> m_stream;
uint8_t *m_remaining_data; //Data left to be sent
uint8_t m_response[7+max_socks_hostname_size];
address m_address; //Address
std::size_t m_remaining_data_len; //Size of the data left to be sent
uint32_t m_4aip; //Used in 4a requests
uint16_t m_port;
uint8_t m_command;
uint8_t m_parseleft; //Octets left to parse
authMethods m_authchosen; //Authentication chosen
addrTypes m_addrtype; //Address type chosen
socksVersions m_socksv; //Socks version
cmdTypes m_cmd; // Command requested
state m_state;
std::atomic<bool> dead; //To avoid cleaning up multiple times
public:
SOCKSHandler(SOCKSServer * parent, boost::asio::ip::tcp::socket * sock) :
m_parent(parent), m_sock(sock), m_stream(nullptr),
m_authchosen(AUTH_UNACCEPTABLE), m_addrtype(ADDR_IPV4), dead(false)
{ m_address.ip = 0; AsyncSockRead(); EnterState(GET_SOCKSV); }
~SOCKSHandler() { Terminate(); }
};
class SOCKSServer: public i2p::client::I2PTunnel
{
private:
std::set<std::shared_ptr<SOCKSHandler> > m_Handlers;
boost::asio::ip::tcp::acceptor m_Acceptor;
boost::asio::deadline_timer m_Timer;
std::mutex m_HandlersMutex;
private:
void Accept();
void HandleAccept(const boost::system::error_code& ecode, boost::asio::ip::tcp::socket * socket);
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 ();
void AddHandler (std::shared_ptr<SOCKSHandler> handler);
void RemoveHandler (std::shared_ptr<SOCKSHandler> handler);
void ClearHandlers ();
};
typedef SOCKSServer SOCKSProxy;
}
}
#endif