1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
|
# -*- coding: utf-8 -*-
"""
digparser
---------
Encode/decode DNS packets from DiG textual representation. Parses
question (if present: +qr flag) & answer sections and returns list
of DNSRecord objects.
Unsupported RR types are skipped (this is different from the packet
parser which will store and encode the RDATA as a binary blob)
>>> dig = os.path.join(os.path.dirname(__file__),"test","dig","google.com-A.dig")
>>> with open(dig) as f:
... l = DigParser(f)
... for record in l:
... print('---')
... print(repr(record))
---
<DNS Header: id=0x5c9a type=QUERY opcode=QUERY flags=RD rcode='NOERROR' q=1 a=0 ns=0 ar=0>
<DNS Question: 'google.com.' qtype=A qclass=IN>
---
<DNS Header: id=0x5c9a type=RESPONSE opcode=QUERY flags=RD,RA rcode='NOERROR' q=1 a=16 ns=0 ar=0>
<DNS Question: 'google.com.' qtype=A qclass=IN>
<DNS RR: 'google.com.' rtype=A rclass=IN ttl=299 rdata='62.252.169.183'>
<DNS RR: 'google.com.' rtype=A rclass=IN ttl=299 rdata='62.252.169.152'>
<DNS RR: 'google.com.' rtype=A rclass=IN ttl=299 rdata='62.252.169.172'>
<DNS RR: 'google.com.' rtype=A rclass=IN ttl=299 rdata='62.252.169.177'>
<DNS RR: 'google.com.' rtype=A rclass=IN ttl=299 rdata='62.252.169.157'>
<DNS RR: 'google.com.' rtype=A rclass=IN ttl=299 rdata='62.252.169.153'>
<DNS RR: 'google.com.' rtype=A rclass=IN ttl=299 rdata='62.252.169.182'>
<DNS RR: 'google.com.' rtype=A rclass=IN ttl=299 rdata='62.252.169.168'>
<DNS RR: 'google.com.' rtype=A rclass=IN ttl=299 rdata='62.252.169.178'>
<DNS RR: 'google.com.' rtype=A rclass=IN ttl=299 rdata='62.252.169.162'>
<DNS RR: 'google.com.' rtype=A rclass=IN ttl=299 rdata='62.252.169.187'>
<DNS RR: 'google.com.' rtype=A rclass=IN ttl=299 rdata='62.252.169.167'>
<DNS RR: 'google.com.' rtype=A rclass=IN ttl=299 rdata='62.252.169.148'>
<DNS RR: 'google.com.' rtype=A rclass=IN ttl=299 rdata='62.252.169.173'>
<DNS RR: 'google.com.' rtype=A rclass=IN ttl=299 rdata='62.252.169.158'>
<DNS RR: 'google.com.' rtype=A rclass=IN ttl=299 rdata='62.252.169.163'>
>>> dig = os.path.join(os.path.dirname(__file__),"test","dig","google.com-ANY.dig")
>>> with open(dig) as f:
... l = DigParser(f)
... for record in l:
... print('---')
... print(repr(record))
---
<DNS Header: id=0xb294 type=QUERY opcode=QUERY flags=RD rcode='NOERROR' q=1 a=0 ns=0 ar=0>
<DNS Question: 'google.com.' qtype=ANY qclass=IN>
---
<DNS Header: id=0xb294 type=RESPONSE opcode=QUERY flags=RD,RA rcode='NOERROR' q=1 a=14 ns=0 ar=0>
<DNS Question: 'google.com.' qtype=ANY qclass=IN>
<DNS RR: 'google.com.' rtype=A rclass=IN ttl=299 rdata='216.58.212.110'>
<DNS RR: 'google.com.' rtype=AAAA rclass=IN ttl=299 rdata='2a00:1450:4009:807::200e'>
<DNS RR: 'google.com.' rtype=CAA rclass=IN ttl=86399 rdata='0 issue "symantec.com"'>
<DNS RR: 'google.com.' rtype=MX rclass=IN ttl=599 rdata='40 alt3.aspmx.l.google.com.'>
<DNS RR: 'google.com.' rtype=MX rclass=IN ttl=599 rdata='10 aspmx.l.google.com.'>
<DNS RR: 'google.com.' rtype=NS rclass=IN ttl=86399 rdata='ns2.google.com.'>
<DNS RR: 'google.com.' rtype=MX rclass=IN ttl=599 rdata='20 alt1.aspmx.l.google.com.'>
<DNS RR: 'google.com.' rtype=SOA rclass=IN ttl=59 rdata='ns2.google.com. dns-admin.google.com. 144578247 900 900 1800 60'>
<DNS RR: 'google.com.' rtype=NS rclass=IN ttl=86399 rdata='ns1.google.com.'>
<DNS RR: 'google.com.' rtype=NS rclass=IN ttl=86399 rdata='ns4.google.com.'>
<DNS RR: 'google.com.' rtype=NS rclass=IN ttl=86399 rdata='ns3.google.com.'>
<DNS RR: 'google.com.' rtype=MX rclass=IN ttl=599 rdata='50 alt4.aspmx.l.google.com.'>
<DNS RR: 'google.com.' rtype=TXT rclass=IN ttl=3599 rdata='"v=spf1 include:_spf.google.com ~all"'>
<DNS RR: 'google.com.' rtype=MX rclass=IN ttl=599 rdata='30 alt2.aspmx.l.google.com.'>
"""
from __future__ import print_function
import glob,os.path,string
from dnslib.lex import WordLexer
from dnslib.dns import (DNSRecord,DNSHeader,DNSQuestion,DNSError,
RR,RD,RDMAP,QR,RCODE,CLASS,QTYPE)
class DigParser:
"""
Parse Dig output
"""
def __init__(self,dig,debug=False):
self.debug = debug
self.l = WordLexer(dig)
self.l.commentchars = ';'
self.l.nltok = ('NL',None)
self.i = iter(self.l)
def parseHeader(self,l1,l2):
_,_,_,opcode,_,status,_,_id = l1.split()
_,flags,_ = l2.split(';')
header = DNSHeader(id=int(_id),bitmap=0)
header.opcode = getattr(QR,opcode.rstrip(','))
header.rcode = getattr(RCODE,status.rstrip(','))
for f in ('qr','aa','tc','rd','ra'):
if f in flags:
setattr(header,f,1)
return header
def expect(self,expect):
t,val = next(self.i)
if t != expect:
raise ValueError("Invalid Token: %s (expecting: %s)" % (t,expect))
return val
def parseQuestions(self,q,dns):
for qname,qclass,qtype in q:
dns.add_question(DNSQuestion(qname,
getattr(QTYPE,qtype),
getattr(CLASS,qclass)))
def parseAnswers(self,a,auth,ar,dns):
sect_map = {'a':'add_answer','auth':'add_auth','ar':'add_ar'}
for sect in 'a','auth','ar':
f = getattr(dns,sect_map[sect])
for rr in locals()[sect]:
rname,ttl,rclass,rtype = rr[:4]
rdata = rr[4:]
rd = RDMAP.get(rtype,RD)
try:
if rd == RD and \
any([ x not in string.hexdigits for x in rdata[-1]]):
# Only support hex encoded data for fallback RD
pass
else:
f(RR(rname=rname,
ttl=int(ttl),
rtype=getattr(QTYPE,rtype),
rclass=getattr(CLASS,rclass),
rdata=rd.fromZone(rdata)))
except DNSError as e:
if self.debug:
print("DNSError:",e,rr)
else:
# Skip records we dont understand
pass
def __iter__(self):
return self.parse()
def parse(self):
dns = None
section = None
paren = False
rr = []
try:
while True:
tok,val = next(self.i)
if tok == 'COMMENT':
if 'Sending:' in val or 'Got answer:' in val:
if dns:
self.parseQuestions(q,dns)
self.parseAnswers(a,auth,ar,dns)
yield(dns)
dns = DNSRecord()
q,a,auth,ar = [],[],[],[]
elif val.startswith('; ->>HEADER<<-'):
self.expect('NL')
val2 = self.expect('COMMENT')
dns.header = self.parseHeader(val,val2)
elif val.startswith('; QUESTION'):
section = q
elif val.startswith('; ANSWER'):
section = a
elif val.startswith('; AUTHORITY'):
section = auth
elif val.startswith('; ADDITIONAL'):
section = ar
elif val.startswith(';') or tok[1].startswith('<<>>'):
pass
elif dns and section == q:
q.append(val.split())
elif tok == 'ATOM':
if val == '(':
paren = True
elif val == ')':
paren = False
else:
rr.append(val)
elif tok == 'NL' and not paren and rr:
if self.debug:
print(">>",rr)
section.append(rr)
rr = []
except StopIteration:
if rr:
self.section.append(rr)
if dns:
self.parseQuestions(q,dns)
self.parseAnswers(a,auth,ar,dns)
yield(dns)
if __name__ == '__main__':
import argparse,doctest,sys
p = argparse.ArgumentParser(description="DigParser Test")
p.add_argument("--dig",action='store_true',default=False,
help="Parse DiG output (stdin)")
p.add_argument("--debug",action='store_true',default=False,
help="Debug output")
args = p.parse_args()
if args.dig:
l = DigParser(sys.stdin,args.debug)
for record in l:
print(repr(record))
else:
doctest.testmod()
|
