New lookup-plugin: `dig' for performing DNS lookups

add support for argument qtype=XXX
remove spurious print
add dict returns
typo
Add dict returns for all major DNS types
Finish adding more types. For now. Until somebody complains.
I forgot to add NAPTR; here it is.
This commit is contained in:
Jan-Piet Mens 2015-02-21 12:18:33 +01:00
parent 1cb47c807e
commit a3618f619e

View file

@ -0,0 +1,212 @@
# (c) 2015, Jan-Piet Mens <jpmens(at)gmail.com>
#
# This file is part of Ansible
#
# Ansible is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Ansible is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Ansible. If not, see <http://www.gnu.org/licenses/>.
from ansible import utils, errors
import socket
HAVE_DNS=False
try:
import dns.resolver
import dns.reversename
from dns.rdatatype import *
from dns.exception import DNSException
HAVE_DNS=True
except ImportError:
pass
def make_rdata_dict(rdata):
''' While the 'dig' lookup plugin supports anything which dnspython supports
out of the box, the following supported_types list describes which
DNS query types we can convert to a dict.
Note: adding support for RRSIG is hard work. :)
'''
supported_types = {
A : ['address'],
AAAA : ['address'],
CNAME : ['target'],
DNAME : ['target'],
DLV : ['algorithm', 'digest_type', 'key_tag', 'digest'],
DNSKEY : ['flags', 'algorithm', 'protocol', 'key'],
DS : ['algorithm', 'digest_type', 'key_tag', 'digest'],
HINFO : ['cpu', 'os'],
LOC : ['latitude', 'longitude', 'altitude', 'size', 'horizontal_precision', 'vertical_precision'],
MX : ['preference', 'exchange'],
NAPTR : ['order', 'preference', 'flags', 'service', 'regexp', 'replacement'],
NS : ['target'],
NSEC3PARAM : ['algorithm', 'flags', 'iterations', 'salt'],
PTR : ['target'],
RP : ['mbox', 'txt'],
# RRSIG : ['algorithm', 'labels', 'original_ttl', 'expiration', 'inception', 'signature'],
SOA : ['mname', 'rname', 'serial', 'refresh', 'retry', 'expire', 'minimum'],
SPF : ['strings'],
SRV : ['priority', 'weight', 'port', 'target'],
SSHFP : ['algorithm', 'fp_type', 'fingerprint'],
TLSA : ['usage', 'selector', 'mtype', 'cert'],
TXT : ['strings'],
}
rd = {}
if rdata.rdtype in supported_types:
fields = supported_types[rdata.rdtype]
for f in fields:
val = rdata.__getattribute__(f)
if type(val) == dns.name.Name:
val = dns.name.Name.to_text(val)
if rdata.rdtype == DLV and f == 'digest':
val = dns.rdata._hexify(rdata.digest).replace(' ', '')
if rdata.rdtype == DS and f == 'digest':
val = dns.rdata._hexify(rdata.digest).replace(' ', '')
if rdata.rdtype == DNSKEY and f == 'key':
val = dns.rdata._base64ify(rdata.key).replace(' ', '')
if rdata.rdtype == NSEC3PARAM and f == 'salt':
val = dns.rdata._hexify(rdata.salt).replace(' ', '')
if rdata.rdtype == SSHFP and f == 'fingerprint':
val = dns.rdata._hexify(rdata.fingerprint).replace(' ', '')
if rdata.rdtype == TLSA and f == 'cert':
val = dns.rdata._hexify(rdata.cert).replace(' ', '')
rd[f] = val
return rd
# ==============================================================
# dig: Lookup DNS records
#
# --------------------------------------------------------------
class LookupModule(object):
def __init__(self, basedir=None, **kwargs):
self.basedir = basedir
if HAVE_DNS == False:
raise errors.AnsibleError("Can't LOOKUP(dig): module dns.resolver is not installed")
def run(self, terms, inject=None, **kwargs):
'''
terms contains a string with things to `dig' for. We support the
following formats:
example.com # A record
example.com qtype=A # same
example.com/TXT # specific qtype
example.com qtype=txt # same
192.168.1.2/PTR # reverse PTR
^^ shortcut for 2.1.168.192.in-addr.arpa/PTR
example.net/AAAA @nameserver # query specified server
^^^ can be comma-sep list of names/addresses
... flat=0 # returns a dict; default is 1 == string
'''
terms = terms.split()
# Create Resolver object so that we can set NS if necessary
myres = dns.resolver.Resolver()
edns_size = 4096
myres.use_edns(0, ednsflags=dns.flags.DO, payload=edns_size)
domain = None
qtype = 'A'
flat = True
for t in terms:
if t.startswith('@'): # e.g. "@10.0.1.2,192.168.1.1" is ok.
nsset = t[1:].split(',')
nameservers = []
for ns in nsset:
# Check if we have a valid IP address. If so, use that, otherwise
# try to resolve name to address using system's resolver. If that
# fails we bail out.
try:
socket.inet_aton(ns)
nameservers.append(ns)
except:
try:
nsaddr = dns.resolver.query(ns)[0].address
nameservers.append(nsaddr)
except Exception, e:
raise errors.AnsibleError("dns lookup NS: ", str(e))
myres.nameservers = nameservers
continue
if '=' in t:
try:
opt, arg = t.split('=')
except:
pass
if opt == 'qtype':
qtype = arg.upper()
elif opt == 'flat':
flat = int(arg)
continue
if '/' in t:
try:
domain, qtype = t.split('/')
except:
domain = t
else:
domain = t
# print "--- domain = {0} qtype={1}".format(domain, qtype)
ret = []
if qtype.upper() == 'PTR':
try:
n = dns.reversename.from_address(domain)
domain = n.to_text()
except dns.exception.SyntaxError:
pass
except Exception, e:
raise errors.AnsibleError("dns.reversename unhandled exception", str(e))
try:
answers = myres.query(domain, qtype)
for rdata in answers:
s = rdata.to_text()
if qtype.upper() == 'TXT':
s = s[1:-1] # Strip outside quotes on TXT rdata
if flat:
ret.append(s)
else:
try:
rd = make_rdata_dict(rdata)
rd['owner'] = answers.canonical_name.to_text()
rd['type'] = dns.rdatatype.to_text(rdata.rdtype)
rd['ttl'] = answers.rrset.ttl
ret.append(rd)
except Exception, e:
ret.append(str(e))
except dns.resolver.NXDOMAIN:
ret.append('NXDOMAIN')
except dns.resolver.NoAnswer:
ret.append("")
except dns.resolver.Timeout:
ret.append('')
except dns.exception.DNSException, e:
raise errors.AnsibleError("dns.resolver unhandled exception", e)
return ret