1 files changed, 149 insertions, 0 deletions
diff --git a/netlib/socks.py b/netlib/socks.py
new file mode 100644
index 00000000..a3c4e9a2
--- /dev/null
+++ b/netlib/socks.py
@@ -0,0 +1,149 @@
+from __future__ import (absolute_import, print_function, division)
+import socket
+import struct
+import array
+from . import tcp
+
+
+class SocksError(Exception):
+    def __init__(self, code, message):
+        super(SocksError, self).__init__(message)
+        self.code = code
+
+
+class VERSION(object):
+    SOCKS4 = 0x04
+    SOCKS5 = 0x05
+
+
+class CMD(object):
+    CONNECT = 0x01
+    BIND = 0x02
+    UDP_ASSOCIATE = 0x03
+
+
+class ATYP(object):
+    IPV4_ADDRESS = 0x01
+    DOMAINNAME = 0x03
+    IPV6_ADDRESS = 0x04
+
+
+class REP(object):
+    SUCCEEDED = 0x00
+    GENERAL_SOCKS_SERVER_FAILURE = 0x01
+    CONNECTION_NOT_ALLOWED_BY_RULESET = 0x02
+    NETWORK_UNREACHABLE = 0x03
+    HOST_UNREACHABLE = 0x04
+    CONNECTION_REFUSED = 0x05
+    TTL_EXPIRED = 0x06
+    COMMAND_NOT_SUPPORTED = 0x07
+    ADDRESS_TYPE_NOT_SUPPORTED = 0x08
+
+
+class METHOD(object):
+    NO_AUTHENTICATION_REQUIRED = 0x00
+    GSSAPI = 0x01
+    USERNAME_PASSWORD = 0x02
+    NO_ACCEPTABLE_METHODS = 0xFF
+
+
+def _read(f, n):
+    try:
+        d = f.read(n)
+        if len(d) == n:
+            return d
+        else:
+            raise SocksError(
+                REP.GENERAL_SOCKS_SERVER_FAILURE,
+                "Incomplete Read"
+            )
+    except socket.error as e:
+        raise SocksError(REP.GENERAL_SOCKS_SERVER_FAILURE, str(e))
+
+
+class ClientGreeting(object):
+    __slots__ = ("ver", "methods")
+
+    def __init__(self, ver, methods):
+        self.ver = ver
+        self.methods = methods
+
+    @classmethod
+    def from_file(cls, f):
+        ver, nmethods = struct.unpack("!BB", _read(f, 2))
+        methods = array.array("B")
+        methods.fromstring(_read(f, nmethods))
+        return cls(ver, methods)
+
+    def to_file(self, f):
+        f.write(struct.pack("!BB", self.ver, len(self.methods)))
+        f.write(self.methods.tostring())
+
+
+class ServerGreeting(object):
+    __slots__ = ("ver", "method")
+
+    def __init__(self, ver, method):
+        self.ver = ver
+        self.method = method
+
+    @classmethod
+    def from_file(cls, f):
+        ver, method = struct.unpack("!BB", _read(f, 2))
+        return cls(ver, method)
+
+    def to_file(self, f):
+        f.write(struct.pack("!BB", self.ver, self.method))
+
+
+class Message(object):
+    __slots__ = ("ver", "msg", "atyp", "addr")
+
+    def __init__(self, ver, msg, atyp, addr):
+        self.ver = ver
+        self.msg = msg
+        self.atyp = atyp
+        self.addr = addr
+
+    @classmethod
+    def from_file(cls, f):
+        ver, msg, rsv, atyp = struct.unpack("!BBBB", _read(f, 4))
+        if rsv != 0x00:
+            raise SocksError(REP.GENERAL_SOCKS_SERVER_FAILURE,
+                             "Socks Request: Invalid reserved byte: %s" % rsv)
+
+        if atyp == ATYP.IPV4_ADDRESS:
+            # We use tnoa here as ntop is not commonly available on Windows.
+            host = socket.inet_ntoa(_read(f, 4))
+            use_ipv6 = False
+        elif atyp == ATYP.IPV6_ADDRESS:
+            host = socket.inet_ntop(socket.AF_INET6, _read(f, 16))
+            use_ipv6 = True
+        elif atyp == ATYP.DOMAINNAME:
+            length, = struct.unpack("!B", _read(f, 1))
+            host = _read(f, length)
+            use_ipv6 = False
+        else:
+            raise SocksError(REP.ADDRESS_TYPE_NOT_SUPPORTED,
+                             "Socks Request: Unknown ATYP: %s" % atyp)
+
+        port, = struct.unpack("!H", _read(f, 2))
+        addr = tcp.Address((host, port), use_ipv6=use_ipv6)
+        return cls(ver, msg, atyp, addr)
+
+    def to_file(self, f):
+        f.write(struct.pack("!BBBB", self.ver, self.msg, 0x00, self.atyp))
+        if self.atyp == ATYP.IPV4_ADDRESS:
+            f.write(socket.inet_aton(self.addr.host))
+        elif self.atyp == ATYP.IPV6_ADDRESS:
+            f.write(socket.inet_pton(socket.AF_INET6, self.addr.host))
+        elif self.atyp == ATYP.DOMAINNAME:
+            f.write(struct.pack("!B", len(self.addr.host)))
+            f.write(self.addr.host)
+        else:
+            raise SocksError(
+                REP.ADDRESS_TYPE_NOT_SUPPORTED,
+                "Unknown ATYP: %s" % self.atyp
+            )
+        f.write(struct.pack("!H", self.addr.port))
+