#!/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 ipaddress import os import signal import socket import sys import time from statistics import stdev import dns.flags import dns.rdatatype import dns.resolver __author__ = 'Babak Farrokhi (babak@farrokhi.net)' __license__ = 'BSD' __version__ = "1.6.4" __progname__ = os.path.basename(sys.argv[0]) shutdown = False def usage(): print("""%s version %s usage: %s [-ehqv] [-s server] [-p port] [-P port] [-S address] [-c count] [-t type] [-w wait] hostname -h --help Show this help -q --quiet Quiet -v --verbose Print actual dns response -s --server DNS server to use (default: first entry from /etc/resolv.conf) -p --port DNS server port number (default: 53) -T --tcp Use TCP instead of UDP -4 --ipv4 Use IPv4 as default network protocol -6 --ipv6 Use IPv6 as default network protocol -P --srcport Query source port number (default: 0) -S --srcip Query source IP address (default: default interface address) -c --count Number of requests to send (default: 10, 0 for infinity) -w --wait Maximum wait time for a reply (default: 2 seconds) -i --interval Time between each request (default: 1 seconds) -t --type DNS request record type (default: A) -e --edns Disable EDNS0 (default: Enabled) """ % (__progname__, __version__, __progname__)) sys.exit(0) def signal_handler(sig, frame): global shutdown if shutdown: # pressed twice, so exit immediately sys.exit(0) shutdown = True # pressed once, exit gracefully def main(): try: signal.signal(signal.SIGTSTP, signal.SIG_IGN) # ignore CTRL+Z signal.signal(signal.SIGINT, signal_handler) # custom CTRL+C handler except AttributeError: # OS Does not support some signals, probably windows pass if len(sys.argv) == 1: usage() # defaults dnsrecord = 'A' count = 10 timeout = 2 interval = 1 quiet = False verbose = False dnsserver = dns.resolver.get_default_resolver().nameservers[0] dst_port = 53 src_port = 0 src_ip = None use_tcp = False use_edns = True af = socket.AF_INET hostname = 'wikipedia.org' try: opts, args = getopt.getopt(sys.argv[1:], "qhc:s:t:w:i:vp:P:S:T46e", ["help", "count=", "server=", "quiet", "type=", "wait=", "interval=", "verbose", "port=", "srcip=", "tcp", "ipv4", "ipv6", "srcport=", "edns"]) except getopt.GetoptError as err: # print help information and exit: print(err, file=sys.stderr) # 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 = abs(int(a)) elif o in ("-v", "--verbose"): verbose = True elif o in ("-s", "--server"): dnsserver = a elif o in ("-p", "--port"): dst_port = int(a) elif o in ("-q", "--quiet"): quiet = True verbose = False elif o in ("-w", "--wait"): timeout = int(a) elif o in ("-i", "--interval"): interval = int(a) elif o in ("-t", "--type"): dnsrecord = a elif o in ("-T", "--tcp"): use_tcp = True elif o in ("-4", "--ipv4"): af = socket.AF_INET elif o in ("-6", "--ipv6"): af = socket.AF_INET6 elif o in ("-e", "--edns"): use_edns = False elif o in ("-P", "--srcport"): src_port = int(a) if src_port < 1024: print("WARNING: Source ports below 1024 are only available to superuser", flush=True) elif o in ("-S", "--srcip"): src_ip = a else: usage() # check if we have a valid dns server address try: ipaddress.ip_address(dnsserver) except ValueError: # so it is not a valid IPv4 or IPv6 address, so try to resolve host name try: dnsserver = socket.getaddrinfo(dnsserver, port=None, family=af)[1][4][0] except OSError: print('Error: cannot resolve hostname:', dnsserver, file=sys.stderr, flush=True) sys.exit(1) resolver = dns.resolver.Resolver() resolver.nameservers = [dnsserver] resolver.timeout = timeout resolver.lifetime = timeout resolver.port = dst_port resolver.retry_servfail = 0 if use_edns: resolver.use_edns(edns=0, payload=8192, ednsflags=dns.flags.edns_from_text('DO')) response_time = [] i = 0 print("%s DNS: %s:%d, hostname: %s, rdatatype: %s" % (__progname__, dnsserver, dst_port, hostname, dnsrecord), flush=True) while not shutdown: if 0 < count <= i: break else: i += 1 try: stime = time.perf_counter() answers = resolver.query(hostname, dnsrecord, source_port=src_port, source=src_ip, tcp=use_tcp, raise_on_no_answer=False) etime = time.perf_counter() except dns.resolver.NoNameservers as e: if not quiet: print("No response to dns request", file=sys.stderr, flush=True) if verbose: print("error:", e, file=sys.stderr, flush=True) sys.exit(1) except dns.resolver.NXDOMAIN as e: if not quiet: print("Hostname does not exist", file=sys.stderr, flush=True) if verbose: print("Error:", e, file=sys.stderr, flush=True) sys.exit(1) except dns.resolver.Timeout: if not quiet: print("Request timeout", flush=True) pass except dns.resolver.NoAnswer: if not quiet: print("No answer", flush=True) pass else: elapsed = answers.response.time * 1000 # convert to milliseconds response_time.append(elapsed) if not quiet: print( "%d bytes from %s: seq=%-3d time=%.3f ms" % ( len(str(answers.rrset)), dnsserver, i, elapsed), flush=True) if verbose: print(answers.rrset, flush=True) print("flags:", dns.flags.to_text(answers.response.flags), flush=True) time_to_next = (stime + interval) - etime if time_to_next > 0: time.sleep(time_to_next) r_sent = i + 1 r_received = len(response_time) r_lost = r_sent - r_received r_lost_percent = (100 * r_lost) / r_sent if response_time: r_min = min(response_time) r_max = max(response_time) r_avg = sum(response_time) / r_received if len(response_time) > 1: r_stddev = stdev(response_time) else: r_stddev = 0 else: r_min = 0 r_max = 0 r_avg = 0 r_stddev = 0 print('\n--- %s dnsping statistics ---' % dnsserver, flush=True) print('%d requests transmitted, %d responses received, %.0f%% lost' % (r_sent, r_received, r_lost_percent), flush=True) print('min=%.3f ms, avg=%.3f ms, max=%.3f ms, stddev=%.3f ms' % (r_min, r_avg, r_max, r_stddev), flush=True) if __name__ == '__main__': main()