twisted/internet/test/_win32ifaces.py

   1 # Copyright (c) Twisted Matrix Laboratories.
   2 # See LICENSE for details.
   3
   4 """
   5 Windows implementation of local network interface enumeration.
   6 """
   7
   8 from socket import socket, AF_INET6, SOCK_STREAM
   9 from ctypes import (
  10     WinDLL, byref, create_string_buffer, c_int, c_void_p,
  11     POINTER, Structure, cast, string_at)
  12
  13 WS2_32 = WinDLL('ws2_32')
  14
  15 SOCKET = c_int
  16 DWORD = c_int
  17 LPVOID = c_void_p
  18 LPSOCKADDR = c_void_p
  19 LPWSAPROTOCOL_INFO = c_void_p
  20 LPTSTR = c_void_p
  21 LPDWORD = c_void_p
  22 LPWSAOVERLAPPED = c_void_p
  23 LPWSAOVERLAPPED_COMPLETION_ROUTINE = c_void_p
  24
  25 # http://msdn.microsoft.com/en-us/library/ms741621(v=VS.85).aspx
  26 # int WSAIoctl(
  27 #         __in   SOCKET s,
  28 #         __in   DWORD dwIoControlCode,
  29 #         __in   LPVOID lpvInBuffer,
  30 #         __in   DWORD cbInBuffer,
  31 #         __out  LPVOID lpvOutBuffer,
  32 #         __in   DWORD cbOutBuffer,
  33 #         __out  LPDWORD lpcbBytesReturned,
  34 #         __in   LPWSAOVERLAPPED lpOverlapped,
  35 #         __in   LPWSAOVERLAPPED_COMPLETION_ROUTINE lpCompletionRoutine
  36 #       );
  37 WSAIoctl = WS2_32.WSAIoctl
  38 WSAIoctl.argtypes = [
  39     SOCKET, DWORD, LPVOID, DWORD, LPVOID, DWORD, LPDWORD,
  40     LPWSAOVERLAPPED, LPWSAOVERLAPPED_COMPLETION_ROUTINE]
  41 WSAIoctl.restype = c_int
  42
  43 # http://msdn.microsoft.com/en-us/library/ms741516(VS.85).aspx
  44 # INT WSAAPI WSAAddressToString(
  45 #         __in      LPSOCKADDR lpsaAddress,
  46 #         __in      DWORD dwAddressLength,
  47 #         __in_opt  LPWSAPROTOCOL_INFO lpProtocolInfo,
  48 #         __inout   LPTSTR lpszAddressString,
  49 #         __inout   LPDWORD lpdwAddressStringLength
  50 #       );
  51 WSAAddressToString = WS2_32.WSAAddressToStringA
  52 WSAAddressToString.argtypes = [
  53     LPSOCKADDR, DWORD, LPWSAPROTOCOL_INFO, LPTSTR, LPDWORD]
  54 WSAAddressToString.restype = c_int
  55
  56
  57 SIO_ADDRESS_LIST_QUERY = 0x48000016
  58 WSAEFAULT = 10014
  59
  60 class SOCKET_ADDRESS(Structure):
  61     _fields_ = [('lpSockaddr', c_void_p),
  62                 ('iSockaddrLength', c_int)]
  63
  64
  65
  66 def make_SAL(ln):
  67     class SOCKET_ADDRESS_LIST(Structure):
  68         _fields_ = [('iAddressCount', c_int),
  69                     ('Address', SOCKET_ADDRESS * ln)]
  70     return SOCKET_ADDRESS_LIST
  71
  72
  73
  74 def win32GetLinkLocalIPv6Addresses():
  75     """
  76     Return a list of strings in colon-hex format representing all the link local
  77     IPv6 addresses available on the system, as reported by
  78     I{WSAIoctl}/C{SIO_ADDRESS_LIST_QUERY}.
  79     """
  80     s = socket(AF_INET6, SOCK_STREAM)
  81     size = 4096
  82     retBytes = c_int()
  83     for i in range(2):
  84         buf = create_string_buffer(size)
  85         ret = WSAIoctl(
  86             s.fileno(),
  87             SIO_ADDRESS_LIST_QUERY, 0, 0, buf, size, byref(retBytes), 0, 0)
  88
  89         # WSAIoctl might fail with WSAEFAULT, which means there was not enough
  90         # space in the buffer we gave it.  There's no way to check the errno
  91         # until Python 2.6, so we don't even try. :/ Maybe if retBytes is still
  92         # 0 another error happened, though.
  93         if ret and retBytes.value:
  94             size = retBytes.value
  95         else:
  96             break
  97
  98     # If it failed, then we'll just have to give up.  Still no way to see why.
  99     if ret:
 100         raise RuntimeError("WSAIoctl failure")
 101
 102     addrList = cast(buf, POINTER(make_SAL(0)))
 103     addrCount = addrList[0].iAddressCount
 104     addrList = cast(buf, POINTER(make_SAL(addrCount)))
 105
 106     addressStringBufLength = 1024
 107     addressStringBuf = create_string_buffer(addressStringBufLength)
 108
 109     retList = []
 110     for i in range(addrList[0].iAddressCount):
 111         retBytes.value = addressStringBufLength
 112         addr = addrList[0].Address[i]
 113         ret = WSAAddressToString(
 114             addr.lpSockaddr, addr.iSockaddrLength, 0, addressStringBuf,
 115             byref(retBytes))
 116         if ret:
 117             raise RuntimeError("WSAAddressToString failure")
 118         retList.append(string_at(addressStringBuf))
 119     return [addr for addr in retList if '%' in addr]