s4-python: import a copy of the python dns library

This library is not installed on enough systems for us to rely
on it being available. We use the system copy if possible, and
fallback to this local copy

Pair-Programmed-With: Andrew Bartlett <abartlet@samba.org>

1 files changed, 163 insertions, 0 deletions

diff --git a/source4/scripting/python/samba_external/dnspython/dns/ipv6.py b/source4/scripting/python/samba_external/dnspython/dns/ipv6.py
new file mode 100644
index 0000000000..33c6713796
--- /dev/null
+++ b/source4/scripting/python/samba_external/dnspython/dns/ipv6.py
@@ -0,0 +1,163 @@
+# Copyright (C) 2003-2007, 2009, 2010 Nominum, Inc.
+#
+# Permission to use, copy, modify, and distribute this software and its
+# documentation for any purpose with or without fee is hereby granted,
+# provided that the above copyright notice and this permission notice
+# appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+"""IPv6 helper functions."""
+
+import re
+
+import dns.exception
+import dns.ipv4
+
+_leading_zero = re.compile(r'0+([0-9a-f]+)')
+
+def inet_ntoa(address):
+    """Convert a network format IPv6 address into text.
+
+    @param address: the binary address
+    @type address: string
+    @rtype: string
+    @raises ValueError: the address isn't 16 bytes long
+    """
+
+    if len(address) != 16:
+        raise ValueError("IPv6 addresses are 16 bytes long")
+    hex = address.encode('hex_codec')
+    chunks = []
+    i = 0
+    l = len(hex)
+    while i < l:
+        chunk = hex[i : i + 4]
+        # strip leading zeros.  we do this with an re instead of
+        # with lstrip() because lstrip() didn't support chars until
+        # python 2.2.2
+        m = _leading_zero.match(chunk)
+        if not m is None:
+            chunk = m.group(1)
+        chunks.append(chunk)
+        i += 4
+    #
+    # Compress the longest subsequence of 0-value chunks to ::
+    #
+    best_start = 0
+    best_len = 0
+    start = -1
+    last_was_zero = False
+    for i in xrange(8):
+        if chunks[i] != '0':
+            if last_was_zero:
+                end = i
+                current_len = end - start
+                if current_len > best_len:
+                    best_start = start
+                    best_len = current_len
+                last_was_zero = False
+        elif not last_was_zero:
+            start = i
+            last_was_zero = True
+    if last_was_zero:
+        end = 8
+        current_len = end - start
+        if current_len > best_len:
+            best_start = start
+            best_len = current_len
+    if best_len > 0:
+        if best_start == 0 and \
+           (best_len == 6 or
+            best_len == 5 and chunks[5] == 'ffff'):
+            # We have an embedded IPv4 address
+            if best_len == 6:
+                prefix = '::'
+            else:
+                prefix = '::ffff:'
+            hex = prefix + dns.ipv4.inet_ntoa(address[12:])
+        else:
+            hex = ':'.join(chunks[:best_start]) + '::' + \
+                  ':'.join(chunks[best_start + best_len:])
+    else:
+        hex = ':'.join(chunks)
+    return hex
+
+_v4_ending = re.compile(r'(.*):(\d+)\.(\d+)\.(\d+)\.(\d+)$')
+_colon_colon_start = re.compile(r'::.*')
+_colon_colon_end = re.compile(r'.*::$')
+
+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 text == '::':
+        text = '0::'
+    #
+    # Get rid of the icky dot-quad syntax if we have it.
+    #
+    m = _v4_ending.match(text)
+    if not m is None:
+        text = "%s:%04x:%04x" % (m.group(1),
+                                 int(m.group(2)) * 256 + int(m.group(3)),
+                                 int(m.group(4)) * 256 + int(m.group(5)))
+    #
+    # 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(':')
+    l = len(chunks)
+    if l > 8:
+        raise dns.exception.SyntaxError
+    seen_empty = False
+    canonical = []
+    for c in chunks:
+        if c == '':
+            if seen_empty:
+                raise dns.exception.SyntaxError
+            seen_empty = True
+            for i in xrange(0, 8 - l + 1):
+                canonical.append('0000')
+        else:
+            lc = len(c)
+            if lc > 4:
+                raise dns.exception.SyntaxError
+            if lc != 4:
+                c = ('0' * (4 - lc)) + c
+            canonical.append(c)
+    if l < 8 and not seen_empty:
+        raise dns.exception.SyntaxError
+    text = ''.join(canonical)
+
+    #
+    # Finally we can go to binary.
+    #
+    try:
+        return text.decode('hex_codec')
+    except TypeError:
+        raise dns.exception.SyntaxError