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, 114 insertions, 0 deletions

diff --git a/source4/scripting/python/samba_external/dnspython/dns/rdataclass.py b/source4/scripting/python/samba_external/dnspython/dns/rdataclass.py
new file mode 100644
index 0000000000..887fd1ad6b
--- /dev/null
+++ b/source4/scripting/python/samba_external/dnspython/dns/rdataclass.py
@@ -0,0 +1,114 @@
+# Copyright (C) 2001-2007, 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.
+
+"""DNS Rdata Classes.
+
+@var _by_text: The rdata class textual name to value mapping
+@type _by_text: dict
+@var _by_value: The rdata class value to textual name mapping
+@type _by_value: dict
+@var _metaclasses: If an rdataclass is a metaclass, there will be a mapping
+whose key is the rdatatype value and whose value is True in this dictionary.
+@type _metaclasses: dict"""
+
+import re
+
+import dns.exception
+
+RESERVED0 = 0
+IN = 1
+CH = 3
+HS = 4
+NONE = 254
+ANY = 255
+
+_by_text = {
+    'RESERVED0' : RESERVED0,
+    'IN' : IN,
+    'CH' : CH,
+    'HS' : HS,
+    'NONE' : NONE,
+    'ANY' : ANY
+    }
+
+# We construct the inverse mapping programmatically to ensure that we
+# cannot make any mistakes (e.g. omissions, cut-and-paste errors) that
+# would cause the mapping not to be true inverse.
+
+_by_value = dict([(y, x) for x, y in _by_text.iteritems()])
+
+# Now that we've built the inverse map, we can add class aliases to
+# the _by_text mapping.
+
+_by_text.update({
+    'INTERNET' : IN,
+    'CHAOS' : CH,
+    'HESIOD' : HS
+    })
+
+_metaclasses = {
+    NONE : True,
+    ANY : True
+    }
+
+_unknown_class_pattern = re.compile('CLASS([0-9]+)$', re.I);
+
+class UnknownRdataclass(dns.exception.DNSException):
+    """Raised when a class is unknown."""
+    pass
+
+def from_text(text):
+    """Convert text into a DNS rdata class value.
+    @param text: the text
+    @type text: string
+    @rtype: int
+    @raises dns.rdataclass.UnknownRdataClass: the class is unknown
+    @raises ValueError: the rdata class value is not >= 0 and <= 65535
+    """
+
+    value = _by_text.get(text.upper())
+    if value is None:
+        match = _unknown_class_pattern.match(text)
+        if match == None:
+            raise UnknownRdataclass
+        value = int(match.group(1))
+        if value < 0 or value > 65535:
+            raise ValueError("class must be between >= 0 and <= 65535")
+    return value
+
+def to_text(value):
+    """Convert a DNS rdata class to text.
+    @param value: the rdata class value
+    @type value: int
+    @rtype: string
+    @raises ValueError: the rdata class value is not >= 0 and <= 65535
+    """
+
+    if value < 0 or value > 65535:
+        raise ValueError("class must be between >= 0 and <= 65535")
+    text = _by_value.get(value)
+    if text is None:
+        text = 'CLASS' + `value`
+    return text
+
+def is_metaclass(rdclass):
+    """True if the class is a metaclass.
+    @param rdclass: the rdata class
+    @type rdclass: int
+    @rtype: bool"""
+
+    if _metaclasses.has_key(rdclass):
+        return True
+    return False