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[socks] try fix SOCKS5 upstream connection

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Signed-off-by: R4SAS <r4sas@i2pmail.org>
socks5
R4SAS 3 years ago
parent 18cb3912e5
commit cb54a50dc5
1 changed files with 96 additions and 59 deletions
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155
libi2pd_client/SOCKS.cpp
Unescape Escape View File

@ -30,6 +30,8 @@ namespace proxy
static const size_t SOCKS_FORWARDER_BUFFER_SIZE = 8192;
static const size_t SOCKS_UPSTREAM_SOCKS4A_REPLY_SIZE = 8;
static const size_t SOCKS_UPSTREAM_SOCKS5_INIT_REPLY_SIZE = 2;
static const size_t SOCKS_UPSTREAM_SOCKS5_CONNECT_REPLY_MIN_SIZE = 10;
struct SOCKSDnsAddress
{
@ -73,43 +75,43 @@ namespace proxy
};
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
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)
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 unsupported
SOCKS5_ADDR_UNSUP = 8, // Address type unsupported
SOCKS4_OK = 90, // No error for SOCKS4
SOCKS4_FAIL = 91, // Failed establishing connecting or not allowed
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 unsupported
SOCKS5_ADDR_UNSUP = 8, // Address type unsupported
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
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
CMD_CONNECT = 1, // TCP Connect
CMD_BIND = 2, // TCP Bind
CMD_UDP = 3 // UDP associate
};
enum socksVersions
{
SOCKS4 = 4, // SOCKS4
SOCKS5 = 5 // SOCKS5
SOCKS4 = 4, // SOCKS4
SOCKS5 = 5 // SOCKS5
};
union address
{
@ -127,7 +129,7 @@ namespace proxy
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);
boost::asio::const_buffers_1 GenerateUpstreamRequest();
boost::asio::const_buffers_1 GenerateUpstreamRequest(int version, bool initial);
bool Socks5ChooseAuth();
void SocksRequestFailed(errTypes error);
void SocksRequestSuccess();
@ -139,7 +141,7 @@ namespace proxy
void SocksUpstreamSuccess();
void AsyncUpstreamSockRead();
void SendUpstreamRequest();
void SendUpstreamRequest(int version, bool initial);
void HandleUpstreamData(uint8_t * buff, std::size_t len);
void HandleUpstreamSockSend(const boost::system::error_code & ecode, std::size_t bytes_transfered);
void HandleUpstreamSockRecv(const boost::system::error_code & ecode, std::size_t bytes_transfered);
@ -154,9 +156,9 @@ namespace proxy
std::shared_ptr<i2p::stream::Stream> m_stream;
uint8_t *m_remaining_data; //Data left to be sent
uint8_t *m_remaining_upstream_data; //upstream data left to be forwarded
uint8_t m_response[7+max_socks_hostname_size];
uint8_t m_response[7 + max_socks_hostname_size];
uint8_t m_upstream_response[SOCKS_UPSTREAM_SOCKS4A_REPLY_SIZE];
uint8_t m_upstream_request[14+max_socks_hostname_size];
uint8_t m_upstream_request[14 + max_socks_hostname_size];
std::size_t m_upstream_response_len;
address m_address; //Address
std::size_t m_remaining_data_len; //Size of the data left to be sent
@ -274,33 +276,49 @@ namespace proxy
return boost::asio::const_buffers_1(m_response, size);
}
boost::asio::const_buffers_1 SOCKSHandler::GenerateUpstreamRequest()
boost::asio::const_buffers_1 SOCKSHandler::GenerateUpstreamRequest(int version, bool initial)
{
size_t upstreamRequestSize = 0;
// TODO: negotiate with upstream
// SOCKS 4a
m_upstream_request[0] = '\x04'; //version
m_upstream_request[1] = m_cmd;
htobe16buf(m_upstream_request + 2, m_port);
m_upstream_request[4] = 0;
m_upstream_request[5] = 0;
m_upstream_request[6] = 0;
m_upstream_request[7] = 1;
// user id
m_upstream_request[8] = 'i';
m_upstream_request[9] = '2';
m_upstream_request[10] = 'p';
m_upstream_request[11] = 'd';
m_upstream_request[12] = 0;
upstreamRequestSize += 13;
if (m_address.dns.size <= max_socks_hostname_size - ( upstreamRequestSize + 1) ) {
// bounds check okay
memcpy(m_upstream_request + upstreamRequestSize, m_address.dns.value, m_address.dns.size);
upstreamRequestSize += m_address.dns.size;
// null terminate
m_upstream_request[++upstreamRequestSize] = 0;
} else {
LogPrint(eLogError, "SOCKS: BUG!!! m_addr.dns.sizs > max_socks_hostname - ( upstreamRequestSize + 1 ) )");
if (version == 5) // SOCKS5
{
if (initial)
{
m_upstream_request[0] = '\x05'; // VER
m_upstream_request[1] = 1; // NAUTH
m_upstream_request[2] = 0; // AUTH
upstreamRequestSize += 3;
}
else
{
return GenerateSOCKS5Response(SOCKS5_GEN_FAIL, m_addrtype, m_address, m_port); // dirty hack, SOCKS5_GEN_FAIL == 1, that's a "establish a TCP/IP stream connection" command
}
}
else if (version == 4) // SOCKS4a
{
m_upstream_request[0] = '\x04'; // VER
m_upstream_request[1] = m_cmd;
htobe16buf(m_upstream_request + 2, m_port);
m_upstream_request[4] = 0;
m_upstream_request[5] = 0;
m_upstream_request[6] = 0;
m_upstream_request[7] = 1;
// user id
m_upstream_request[8] = 'i';
m_upstream_request[9] = '2';
m_upstream_request[10] = 'p';
m_upstream_request[11] = 'd';
m_upstream_request[12] = 0;
upstreamRequestSize += 13;
if (m_address.dns.size <= max_socks_hostname_size - ( upstreamRequestSize + 1) ) {
// bounds check okay
memcpy(m_upstream_request + upstreamRequestSize, m_address.dns.value, m_address.dns.size);
upstreamRequestSize += m_address.dns.size;
// null terminate
m_upstream_request[++upstreamRequestSize] = 0;
} else {
LogPrint(eLogError, "SOCKS: BUG!!! m_addr.dns.size > max_socks_hostname - ( upstreamRequestSize + 1 ) )");
}
}
return boost::asio::const_buffers_1(m_upstream_request, upstreamRequestSize);
}
@ -417,6 +435,7 @@ namespace proxy
{
case GET_SOCKSV:
m_socksv = (SOCKSHandler::socksVersions) *sock_buff;
LogPrint(eLogInfo, "SOCKS: received version: ", ((int)*sock_buff));
switch (*sock_buff)
{
case SOCKS4:
@ -704,7 +723,7 @@ namespace proxy
break;
case SOCKS5:
LogPrint(eLogInfo, "SOCKS: v5 connection success");
//HACK only 16 bits passed in port as SOCKS5 doesn't allow for more
// HACK only 16 bits passed in port as SOCKS5 doesn't allow for more
response = GenerateSOCKS5Response(SOCKS5_OK, ADDR_DNS, m_address, m_port);
break;
}
@ -715,7 +734,6 @@ namespace proxy
GetOwner()->AddHandler(forwarder);
forwarder->Start();
Terminate();
}
void SOCKSHandler::HandleUpstreamData(uint8_t * dataptr, std::size_t len)
@ -723,14 +741,33 @@ namespace proxy
if (m_state == UPSTREAM_HANDSHAKE) {
m_upstream_response_len += len;
// handle handshake data
if (m_upstream_response_len < SOCKS_UPSTREAM_SOCKS4A_REPLY_SIZE) {
if (m_upstream_response_len == SOCKS_UPSTREAM_SOCKS5_INIT_REPLY_SIZE) {
if (m_upstream_response[0] == '\x05' && m_upstream_response[1] != AUTH_UNACCEPTABLE) {
LogPrint(eLogInfo, "SOCKS: upstream proxy: success greeting");
SendUpstreamRequest(m_socksv, false);
} else {
LogPrint(eLogError, "SOCKS: upstream proxy failure: no acceptable methods were offered");
SocksRequestFailed(SOCKS5_GEN_FAIL);
}
}
else if (m_upstream_response[0] == '\x05' && m_upstream_response_len >= SOCKS_UPSTREAM_SOCKS5_CONNECT_REPLY_MIN_SIZE)
{
uint8_t resp = m_upstream_response[1];
if (resp == SOCKS5_OK) {
SocksUpstreamSuccess();
} else {
LogPrint(eLogError, "SOCKS: upstream proxy failure: ", (int) resp);
SocksRequestFailed(SOCKS5_GEN_FAIL);
}
}
else if (m_upstream_response_len < SOCKS_UPSTREAM_SOCKS4A_REPLY_SIZE) {
// too small, continue reading
AsyncUpstreamSockRead();
} else if (len == SOCKS_UPSTREAM_SOCKS4A_REPLY_SIZE) {
// just right
uint8_t resp = m_upstream_response[1];
if (resp == SOCKS4_OK) {
// we have connected !
// we have connected!
SocksUpstreamSuccess();
} else {
// upstream failure
@ -748,12 +785,12 @@ namespace proxy
}
}
void SOCKSHandler::SendUpstreamRequest()
void SOCKSHandler::SendUpstreamRequest(int version, bool initial)
{
LogPrint(eLogInfo, "SOCKS: Negotiating with upstream proxy");
EnterState(UPSTREAM_HANDSHAKE);
if (m_upstreamSock) {
boost::asio::write(*m_upstreamSock, GenerateUpstreamRequest());
boost::asio::write(*m_upstreamSock, GenerateUpstreamRequest(version, initial));
AsyncUpstreamSockRead();
} else {
LogPrint(eLogError, "SOCKS: No upstream socket to send handshake to");
@ -768,7 +805,7 @@ namespace proxy
return;
}
LogPrint(eLogInfo, "SOCKS: Connected to upstream proxy");
SendUpstreamRequest();
SendUpstreamRequest(m_socksv, true); // try SOCKS5 first
}
void SOCKSHandler::HandleUpstreamResolved(const boost::system::error_code & ecode, boost::asio::ip::tcp::resolver::iterator itr)

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