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
|
#!/usr/bin/env python
# 1156, Thu 8 Jun 2017 (NZDT)
# test-pldns-tcp.py: Demonstrate Ldns objects from tcp
# Copyright (C) 2017, Nevil Brownlee, U Auckland
import plt
import pldns
from plt_testing import *
t = plt.trace('pcapfile:dns_valid_response_tcp.pcap')
t.start()
n = 0; margin = ' '*7
for pkt in t:
n += 1 # Wireshark uses 1-org packet numbers
ip = pkt.ip
if not ip:
continue # Not IP
if ip.frag_offset != 0:
continue # Non-first fragment
tcp = pkt.tcp
if not tcp:
continue # Not TCP
if not (tcp.src_port == 53 or tcp.dst_port == 53):
continue
payload = tcp.payload
if not payload:
continue
ldns_obj = pldns.ldns(payload)
test_println("%5d: %s -> %s" % (n, tcp.src_prefix, tcp.dst_prefix), get_tag())
if not ldns_obj.is_ok():
test_println("%sCouldn't make ldns_obj, status = <%s>" % (
margin, ldns_obj.errorstr(ldns_obj.status)), get_tag())
continue
rk = 'query'
if ldns_obj.is_response:
rk = 'response'
test_println("%s%s, ident=%04x, opcode=%d (%s), rcode=%d (%s)" % (margin,
rk, ldns_obj.ident, ldns_obj.opcode, pldns.opcodestr(ldns_obj.opcode),
ldns_obj.rcode, pldns.rcodestr(ldns_obj.rcode)), get_tag())
q_rr_list = ldns_obj.query_rr_list
if not q_rr_list:
test_println("%sQuery list empty" % margin, get_tag())
else:
test_println("%sQuery list (%d items)" % (margin, len(q_rr_list)), get_tag())
for rr in q_rr_list:
test_println("%s %s\t%3d" % (margin, rr.owner, rr.type), get_tag())
if ldns_obj.is_response:
an_rr_list = ldns_obj.response_rr_list
if not an_rr_list:
test_println("%sResponse list empty" % margin, get_tag())
else:
test_println("%sResponse list (%d items)" % (margin, len(an_rr_list)), get_tag())
for rr in an_rr_list:
test_println("%s %s\t%3d\t%s\t%s" % (margin,
rr.owner, rr.ttl, pldns.typestr(rr.type), rr.rdata), get_tag())
au_rr_list = ldns_obj.auth_rr_list
if not au_rr_list:
test_println("%sAuthority list empty" % margin, get_tag())
else:
test_println("%sAuthority list (%d items)" % (margin, len(au_rr_list)), get_tag())
for rr in au_rr_list:
test_println("%s %s\t%3d\t%s\t%s" % (margin,
rr.owner, rr.ttl, pldns.typestr(rr.type), rr.rdata), get_tag())
ad_rr_list = ldns_obj.addit_rr_list
if not ad_rr_list:
test_println("%sAdditional list empty" % margin, get_tag())
else:
test_println("%sAdditional list (%d items)" % (margin, len(ad_rr_list)), get_tag())
for rr in ad_rr_list:
test_println("%s %s\t%3d\t%s\t%s" % (margin,
rr.owner, rr.ttl, pldns.typestr(rr.type), rr.rdata), get_tag())
test_println('', get_tag()) # Blank line
#if n == 20: # Packet 551 is a first fragment
# break
t.close() # Don't do this inside the loop!
test_println("%d packets read" % n, get_tag())
|
