Limnoria/src/utils/net.py

###
# Copyright (c) 2002-2005, Jeremiah Fincher
# Copyright (c) 2011, James Vega
# All rights reserved.
#
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# modification, are permitted provided that the following conditions are met:
#
#   * Redistributions of source code must retain the above copyright notice,
#     this list of conditions, and the following disclaimer.
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#     documentation and/or other materials provided with the distribution.
#   * Neither the name of the author of this software nor the name of
#     contributors to this software may be used to endorse or promote products
#     derived from this software without specific prior written consent.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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###

"""
Simple utility modules.
"""

import re
import socket

class EmailRe:
    """Fake class used for backward compatibility."""

    rfc822_specials = '()<>@,;:\\"[]'
    def match(self, addr):
        # From http://www.secureprogramming.com/?action=view&feature=recipes&recipeid=1

        # First we validate the name portion (name@domain)
        c = 0
        while c < len(addr):
            if addr[c] == '"' and (not c or addr[c - 1] == '.' or addr[c - 1] == '"'):
                c = c + 1
                while c < len(addr):
                    if addr[c] == '"': break
                    if addr[c] == '\\' and addr[c + 1] == ' ':
                        c = c + 2
                        continue
                    if ord(addr[c]) < 32 or ord(addr[c]) >= 127: return 0
                    c = c + 1
                else: return 0
                if addr[c] == '@': break
                if addr[c] != '.': return 0
                c = c + 1
                continue
            if addr[c] == '@': break
            if ord(addr[c]) <= 32 or ord(addr[c]) >= 127: return 0
            if addr[c] in self.rfc822_specials: return 0
            c = c + 1
        if not c or addr[c - 1] == '.': return 0

        # Next we validate the domain portion (name@domain)
        domain = c = c + 1
        if domain >= len(addr): return 0
        count = 0
        while c < len(addr):
            if addr[c] == '.':
                if c == domain or addr[c - 1] == '.': return 0
                count = count + 1
            if ord(addr[c]) <= 32 or ord(addr[c]) >= 127: return 0
            if addr[c] in self.rfc822_specials: return 0
            c = c + 1

        return count >= 1
emailRe = EmailRe()

def getSocket(host):
    """Returns a socket of the correct AF_INET type (v4 or v6) in order to
    communicate with host.
    """
    addrinfo = socket.getaddrinfo(host, None)
    host = addrinfo[0][4][0]
    if isIPV4(host):
        return socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    elif isIPV6(host):
        return socket.socket(socket.AF_INET6, socket.SOCK_STREAM)
    else:
        raise socket.error, 'Something wonky happened.'

def isIP(s):
    """Returns whether or not a given string is an IP address.

    >>> isIP('255.255.255.255')
    1

    >>> isIP('::1')
    0
    """
    return isIPV4(s) or isIPV6(s)

def isIPV4(s):
    """Returns whether or not a given string is an IPV4 address.

    >>> isIPV4('255.255.255.255')
    1

    >>> isIPV4('abc.abc.abc.abc')
    0
    """
    try:
        return bool(socket.inet_pton(socket.AF_INET, s))
    except socket.error:
        return False

def bruteIsIPV6(s):
    if s.count('::') <= 1:
        L = s.split(':')
        if len(L) <= 8:
            for x in L:
                if x:
                    try:
                        int(x, 16)
                    except ValueError:
                        return False
            return True
    return False

def isIPV6(s):
    """Returns whether or not a given string is an IPV6 address."""
    try:
        if hasattr(socket, 'inet_pton'):
            return bool(socket.inet_pton(socket.AF_INET6, s))
        else:
            return bruteIsIPV6(s)
    except socket.error:
        try:
            socket.inet_pton(socket.AF_INET6, '::')
        except socket.error:
            # We gotta fake it.
            return bruteIsIPV6(s)
        return False

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