From 4bbc3ff037026c72f3249f59c1b5af69a6ad6d69 Mon Sep 17 00:00:00 2001 From: Jelmer Vernooij Date: Mon, 29 Mar 2010 16:08:11 +0200 Subject: s4-python: Move dnspython to lib/, like the other Python modules This also avoids it from being installed if it's already present on the system. --- lib/dnspython/dns/opcode.py | 104 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 104 insertions(+) create mode 100644 lib/dnspython/dns/opcode.py (limited to 'lib/dnspython/dns/opcode.py') diff --git a/lib/dnspython/dns/opcode.py b/lib/dnspython/dns/opcode.py new file mode 100644 index 0000000000..735d3a1f7d --- /dev/null +++ b/lib/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 -- cgit