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

[idra/samba.git] / source4 / scripting / python / samba_external / dnspython / dns / flags.py

diff --git a/source4/scripting/python/samba_external/dnspython/dns/flags.py b/source4/scripting/python/samba_external/dnspython/dns/flags.py
new file mode 100644 (file)
index 0000000..79375ea
--- /dev/null
+++ b/source4/scripting/python/samba_external/dnspython/dns/flags.py
@@ -0,0 +1,106 @@
+# 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 Message Flags."""
+
+# Standard DNS flags
+
+QR = 0x8000
+AA = 0x0400
+TC = 0x0200
+RD = 0x0100
+RA = 0x0080
+AD = 0x0020
+CD = 0x0010
+
+# EDNS flags
+
+DO = 0x8000
+
+_by_text = {
+    'QR' : QR,
+    'AA' : AA,
+    'TC' : TC,
+    'RD' : RD,
+    'RA' : RA,
+    'AD' : AD,
+    'CD' : CD
+}
+
+_edns_by_text = {
+    'DO' : DO
+}
+
+
+# We construct the inverse mappings programmatically to ensure that we
+# cannot make any mistakes (e.g. omissions, cut-and-paste errors) that
+# would cause the mappings not to be true inverses.
+
+_by_value = dict([(y, x) for x, y in _by_text.iteritems()])
+
+_edns_by_value = dict([(y, x) for x, y in _edns_by_text.iteritems()])
+
+def _order_flags(table):
+    order = list(table.iteritems())
+    order.sort()
+    order.reverse()
+    return order
+
+_flags_order = _order_flags(_by_value)
+
+_edns_flags_order = _order_flags(_edns_by_value)
+
+def _from_text(text, table):
+    flags = 0
+    tokens = text.split()
+    for t in tokens:
+        flags = flags | table[t.upper()]
+    return flags
+
+def _to_text(flags, table, order):
+    text_flags = []
+    for k, v in order:
+        if flags & k != 0:
+            text_flags.append(v)
+    return ' '.join(text_flags)
+
+def from_text(text):
+    """Convert a space-separated list of flag text values into a flags
+    value.
+    @rtype: int"""
+
+    return _from_text(text, _by_text)
+
+def to_text(flags):
+    """Convert a flags value into a space-separated list of flag text
+    values.
+    @rtype: string"""
+
+    return _to_text(flags, _by_value, _flags_order)
+
+
+def edns_from_text(text):
+    """Convert a space-separated list of EDNS flag text values into a EDNS
+    flags value.
+    @rtype: int"""
+
+    return _from_text(text, _edns_by_text)
+
+def edns_to_text(flags):
+    """Convert an EDNS flags value into a space-separated list of EDNS flag
+    text values.
+    @rtype: string"""
+
+    return _to_text(flags, _edns_by_value, _edns_flags_order)