def inet_aton()

in functions/source/populate_NLB_TG_with_ALB/dns/ipv6.py [0:0]

• 44 lines of code
• 18 McCabe index (conditional complexity)

def inet_aton(text):
    """Convert a text format IPv6 address into network format.

    @param text: the textual address
    @type text: string
    @rtype: string
    @raises dns.exception.SyntaxError: the text was not properly formatted
    """

    #
    # Our aim here is not something fast; we just want something that works.
    #
    if not isinstance(text, binary_type):
        text = text.encode()

    if text == b'::':
        text = b'0::'
    #
    # Get rid of the icky dot-quad syntax if we have it.
    #
    m = _v4_ending.match(text)
    if not m is None:
        b = bytearray(dns.ipv4.inet_aton(m.group(2)))
        text = (u"%s:%02x%02x:%02x%02x" % (m.group(1).decode(), b[0], b[1],
                                           b[2], b[3])).encode()
    #
    # Try to turn '::<whatever>' into ':<whatever>'; if no match try to
    # turn '<whatever>::' into '<whatever>:'
    #
    m = _colon_colon_start.match(text)
    if not m is None:
        text = text[1:]
    else:
        m = _colon_colon_end.match(text)
        if not m is None:
            text = text[:-1]
    #
    # Now canonicalize into 8 chunks of 4 hex digits each
    #
    chunks = text.split(b':')
    l = len(chunks)
    if l > 8:
        raise dns.exception.SyntaxError
    seen_empty = False
    canonical = []
    for c in chunks:
        if c == b'':
            if seen_empty:
                raise dns.exception.SyntaxError
            seen_empty = True
            for i in xrange(0, 8 - l + 1):
                canonical.append(b'0000')
        else:
            lc = len(c)
            if lc > 4:
                raise dns.exception.SyntaxError
            if lc != 4:
                c = (b'0' * (4 - lc)) + c
            canonical.append(c)
    if l < 8 and not seen_empty:
        raise dns.exception.SyntaxError
    text = b''.join(canonical)

    #
    # Finally we can go to binary.
    #
    try:
        return binascii.unhexlify(text)
    except (binascii.Error, TypeError):
        raise dns.exception.SyntaxError