Initial commit

lib/win_inet_pton.py

@@ -0,0 +1,126 @@
+# This software released into the public domain. Anyone is free to copy,
+# modify, publish, use, compile, sell, or distribute this software,
+# either in source code form or as a compiled binary, for any purpose,
+# commercial or non-commercial, and by any means.
+
+import socket
+import os
+import sys
+
+
+def inject_into_socket():
+    import ctypes
+
+    class in_addr(ctypes.Structure):
+        _fields_ = [("S_addr", ctypes.c_ubyte * 4)]
+
+    class in6_addr(ctypes.Structure):
+        _fields_ = [("Byte", ctypes.c_ubyte * 16)]
+
+    if hasattr(ctypes, "windll"):
+        # InetNtopW(
+        #   INT         family,
+        #   const VOID  *pAddr,
+        #   PWSTR       pStringBuf,
+        #   size_t      StringBufSize
+        # ) -> PCWSTR
+        InetNtopW = ctypes.windll.ws2_32.InetNtopW
+
+        # InetPtonW(
+        #   INT         family,
+        #   PCWSTR      pszAddrString,
+        #   PVOID       pAddrBuf
+        # ) -> INT
+        InetPtonW = ctypes.windll.ws2_32.InetPtonW
+
+        # WSAGetLastError() -> INT
+        WSAGetLastError = ctypes.windll.ws2_32.WSAGetLastError
+    else:
+
+        def not_windows():
+            raise SystemError("Invalid platform. ctypes.windll must be available.")
+
+        InetNtopW = not_windows
+        InetPtonW = not_windows
+        WSAGetLastError = not_windows
+
+    def inet_pton(address_family, ip_string):
+        if sys.version_info[0] > 2 and isinstance(ip_string, bytes):
+            raise TypeError("inet_pton() argument 2 must be str, not bytes")
+
+        if address_family == socket.AF_INET:
+            family = 2
+            addr = in_addr()
+        elif address_family == socket.AF_INET6:
+            family = 23
+            addr = in6_addr()
+        else:
+            raise OSError("unknown address family")
+
+        ip_string = ctypes.c_wchar_p(ip_string)
+        ret = InetPtonW(ctypes.c_int(family), ip_string, ctypes.byref(addr))
+
+        if ret == 1:
+            if address_family == socket.AF_INET:
+                return ctypes.string_at(addr.S_addr, 4)
+            else:
+                return ctypes.string_at(addr.Byte, 16)
+        elif ret == 0:
+            raise socket.error("illegal IP address string passed to inet_pton")
+        else:
+            err = WSAGetLastError()
+            if err == 10047:
+                e = socket.error("unknown address family")
+            elif err == 10014:
+                e = OSError("bad address")
+            else:
+                e = OSError("unknown error from inet_ntop")
+            e.errno = err
+            raise e
+
+    def inet_ntop(address_family, packed_ip):
+        if address_family == socket.AF_INET:
+            addr = in_addr()
+            if len(packed_ip) != ctypes.sizeof(addr.S_addr):
+                raise ValueError("packed IP wrong length for inet_ntop")
+
+            ctypes.memmove(addr.S_addr, packed_ip, 4)
+            buffer_len = 16
+            family = 2
+
+        elif address_family == socket.AF_INET6:
+            addr = in6_addr()
+            if len(packed_ip) != ctypes.sizeof(addr.Byte):
+                raise ValueError("packed IP wrong length for inet_ntop")
+
+            ctypes.memmove(addr.Byte, packed_ip, 16)
+            buffer_len = 46
+            family = 23
+        else:
+            raise ValueError("unknown address family")
+
+        buffer = ctypes.create_unicode_buffer(buffer_len)
+
+        ret = InetNtopW(
+            ctypes.c_int(family),
+            ctypes.byref(addr),
+            ctypes.byref(buffer),
+            ctypes.sizeof(buffer),
+        )
+        if ret is None:
+            err = WSAGetLastError()
+            if err == 10047:
+                e = ValueError("unknown address family")
+            else:
+                e = OSError("unknown error from inet_ntop")
+            e.errno = err
+
+        return ctypes.wstring_at(buffer, buffer_len).rstrip("\x00")
+
+    # Adding our two functions to the socket library
+    socket.inet_pton = inet_pton
+    socket.inet_ntop = inet_ntop
+
+
+if os.name == "nt" and not hasattr(socket, "inet_pton"):
+    inject_into_socket()