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, 104 insertions, 0 deletions

diff --git a/source4/scripting/python/samba_external/dnspython/dns/opcode.py b/source4/scripting/python/samba_external/dnspython/dns/opcode.py
new file mode 100644
index 0000000000..735d3a1f7d
--- /dev/null
+++ b/source4/scripting/python/samba_external/dnspython/dns/opcode.py
@@ -0,0 +1,104 @@
+# 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 Opcodes."""
+
+import dns.exception
+
+QUERY = 0
+IQUERY = 1
+STATUS = 2
+NOTIFY = 4
+UPDATE = 5
+
+_by_text = {
+    'QUERY' : QUERY,
+    'IQUERY' : IQUERY,
+    'STATUS' : STATUS,
+    'NOTIFY' : NOTIFY,
+    'UPDATE' : UPDATE
+}
+
+# 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()])
+
+
+class UnknownOpcode(dns.exception.DNSException):
+    """Raised if an opcode is unknown."""
+    pass
+
+def from_text(text):
+    """Convert text into an opcode.
+
+    @param text: the textual opcode
+    @type text: string
+    @raises UnknownOpcode: the opcode is unknown
+    @rtype: int
+    """
+
+    if text.isdigit():
+        value = int(text)
+        if value >= 0 and value <= 15:
+            return value
+    value = _by_text.get(text.upper())
+    if value is None:
+        raise UnknownOpcode
+    return value
+
+def from_flags(flags):
+    """Extract an opcode from DNS message flags.
+
+    @param flags: int
+    @rtype: int
+    """
+
+    return (flags & 0x7800) >> 11
+
+def to_flags(value):
+    """Convert an opcode to a value suitable for ORing into DNS message
+    flags.
+    @rtype: int
+    """
+
+    return (value << 11) & 0x7800
+
+def to_text(value):
+    """Convert an opcode to text.
+
+    @param value: the opcdoe
+    @type value: int
+    @raises UnknownOpcode: the opcode is unknown
+    @rtype: string
+    """
+
+    text = _by_value.get(value)
+    if text is None:
+        text = str(value)
+    return text
+
+def is_update(flags):
+    """True if the opcode in flags is UPDATE.
+
+    @param flags: DNS flags
+    @type flags: int
+    @rtype: bool
+    """
+
+    if (from_flags(flags) == UPDATE):
+        return True
+    return False