add initial version of dnstraceroute utility

- also updated README and TODO
- made a symlink to dns directory under dnspython module directory (I
  could not figure out an smarter way to do this)
This commit is contained in:
Babak Farrokhi 2016-04-07 14:23:28 +04:30
parent bbdeb0b032
commit fb68ba76d7
4 changed files with 216 additions and 6 deletions

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DNS Diagnostics and Performance Measurement Tools DNS Diagnostics and Performance Measurement Tools
# prerequisites # prerequisites
This script requires python3 as well as latest [dnspython](http://www.dnspython.org/) This script requires python3 as well as latest [dnspython](http://www.dnspython.org/).
Please note that "dnstraceroute" requires a modified version of dnspython module, which is included. You just need to run `git submodule update --init`
# dnsping # dnsping
dnsping pings a DNS resolver by sending an arbitrary DNS query for given number of times: dnsping pings a DNS resolver by sending an arbitrary DNS query for given number of times:
@ -35,7 +36,22 @@ server avg(ms) min(ms) max(ms) stddev(ms) lost(%)
208.67.222.222 179.068 135.975 258.582 50.681 %0 208.67.222.222 179.068 135.975 258.582 50.681 %0
208.67.220.220 137.817 135.822 140.113 1.504 %0 208.67.220.220 137.817 135.822 140.113 1.504 %0
``` ```
# todo
- input sanitization # dnstraceroute
- new tool: DNS traceroute dnstraceroute is a traceroute utility to figure out the path that your DNS request is passing through to get to its destination. You may want to compare it to your actual network traceroute and make sure your DNS traffic is not routed to any unwanted path.
```
% ./dnstraceroute.py -s 4.2.2.1 yahoo.com
dnstraceroute.py 4.2.2.1: hostname=yahoo.com rdatatype=A
1 192.168.199.57 (192.168.199.57) 47 ms
2 192.168.198.21 (192.168.198.21) 21 ms
3 192.168.169.169 (192.168.169.169) 27 ms
4 192.168.168.137 (192.168.168.137) 28 ms
5 so-5-0-0.franco71.fra.seabone.net (89.221.34.6) 23 ms
6 xe-5-3-1.fra44.ip4.gtt.net (89.149.129.185) 62 ms
7 * 1126 ms
8 ae-1-60.edge5.Frankfurt1.Level3.net (4.69.154.9) 62 ms
9 ae-1-60.edge5.Frankfurt1.Level3.net (4.69.154.9) 12 ms
10 a.resolvers.level3.net (4.2.2.1) 171 ms
```

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# todo # todo
- input sanitization - input sanitization
- new tool: DNS traceroute

1
dns Symbolic link
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dnspython/dns

194
dnstraceroute.py Executable file
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#!/usr/bin/env python3
#
# Copyright (c) 2016, Babak Farrokhi
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# * Redistributions of source code must retain the above copyright notice, this
# list of conditions and the following disclaimer.
#
# * Redistributions in binary form must reproduce the above copyright notice,
# this list of conditions and the following disclaimer in the documentation
# and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
import getopt
import signal
import sys
import socket
import time
import dns.rdatatype
import dns.resolver
__VERSION__ = 1.0
__PROGNAME__ = sys.argv[0]
should_stop = False
def usage():
print('%s version %1.1f\n' % (__PROGNAME__, __VERSION__))
print('syntax: %s [-h] [-q] [-s server] [-c count] [-t type] [-w wait] hostname' % __PROGNAME__)
print(' -h --help show this help')
print(' -q --quiet quiet')
print(' -s --server dns server to use (default: 8.8.8.8)')
print(' -c --count maximum number of hops (default: 30)')
print(' -w --wait maximum wait time for a reply (default: 5)')
print(' -t --type DNS request record type (default: A)')
print(' ')
exit()
def signal_handler(sig, frame):
global should_stop
if should_stop: # pressed twice, so exit immediately
exit(0)
should_stop = True # pressed once, exit gracefully
def main():
signal.signal(signal.SIGTSTP, signal.SIG_IGN) # ignore CTRL+Z
signal.signal(signal.SIGINT, signal_handler) # custom CTRL+C handler
if len(sys.argv) == 1:
usage()
dnsrecord = 'A'
count = 30
timeout = 1
quiet = False
dnsserver = '8.8.8.8'
hostname = 'wikipedia.org'
dnsport = 53
hops = 0
try:
opts, args = getopt.getopt(sys.argv[1:], "qhc:s:t:w:",
["help", "output=", "count=", "server=", "quiet", "type=", "wait="])
except getopt.GetoptError as err:
# print help information and exit:
print(err) # will print something like "option -a not recognized"
usage()
if args and len(args) == 1:
hostname = args[0]
else:
usage()
for o, a in opts:
if o in ("-h", "--help"):
usage()
elif o in ("-c", "--count"):
count = int(a)
elif o in ("-s", "--server"):
dnsserver = a
elif o in ("-q", "--quiet"):
quiet = True
elif o in ("-w", "--wait"):
timeout = int(a)
elif o in ("-t", "--type"):
dnsrecord = a
else:
usage()
resolver = dns.resolver.Resolver()
resolver.nameservers = [dnsserver]
resolver.timeout = timeout
resolver.lifetime = timeout
resolver.retry_servfail = 0
icmp = socket.getprotobyname('icmp')
response_time = []
i = 0
ttl = 1
reached = False
print("%s %s: hostname=%s rdatatype=%s" % (__PROGNAME__, dnsserver, hostname, dnsrecord))
while True:
if should_stop:
break
icmp_socket = socket.socket(socket.AF_INET, socket.SOCK_RAW, icmp)
icmp_socket.bind(("", dnsport))
icmp_socket.settimeout(timeout)
try: # send DNS request
stime = time.time()
answers = resolver.query(hostname, dnsrecord, ipttl = ttl)
except dns.resolver.NoNameservers as e:
if not quiet:
print("no response:", e)
exit(1)
except dns.resolver.NXDOMAIN as e:
if not quiet:
print("Invalid hostname:", e)
exit(1)
except dns.resolver.Timeout:
pass
except dns.resolver.NoAnswer:
if not quiet:
print("invalid answer")
pass
except:
print("unxpected error: ", sys.exc_info()[0])
exit(1)
else:
reached = True
curr_addr = None
curr_host = None
try: # expect ICMP response
_, curr_addr = icmp_socket.recvfrom(512)
curr_addr = curr_addr[0]
except socket.error:
pass
finally:
icmp_socket.close()
etime = time.time()
elapsed = (etime - stime) * 1000 # convert to milliseconds
if reached:
curr_addr = dnsserver
elapsed -= timeout*1000
try:
if curr_addr != "*":
curr_name = socket.gethostbyaddr(curr_addr)[0]
except socket.error:
curr_name = curr_addr
except:
print("unxpected error: ", sys.exc_info()[0])
if curr_addr:
curr_host = "%s (%s)" % (curr_name, curr_addr)
else:
curr_host = "*"
print("%d\t%s %d ms" % (ttl, curr_host, elapsed))
ttl += 1
hops += 1
if (hops >= count) or (curr_addr == dnsserver) or reached:
break
if __name__ == '__main__':
main()