initial version of dnsping utility

.gitignore

@@ -2,6 +2,7 @@
 __pycache__/
 *.py[cod]
 *$py.class
+.idea/
 
 # C extensions
 *.so

dnsping.py

@@ -0,0 +1,159 @@
+#!/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 time
+from statistics import stdev
+import sys
+import signal
+
+import dns.rdatatype
+import dns.resolver
+
+__VERSION__ = 1.0
+
+
+def usage():
+    print('dnsping version %1.1f\n' % __VERSION__)
+    print('syntax: dnsping [-h] [-q] [-s server] [-c count] [-t type] [-w wait] hostname')
+    print('  -h  --help      show this help')
+    print('  -q  --quiet     quiet')
+    print('  -v  --verbose   print actual dns response')
+    print('  -s  --server    dns server to use (default: 8.8.8.8)')
+    print('  -c  --count     number of requests to send (default: 10)')
+    print('  -w  --wait      maximum wait time for a reply (default: 5)')
+    print('  -t  --type      DNS request record type (default: A)')
+    print('  ')
+    exit()
+
+
+def main():
+    # if not __debug__:
+    #     signal.signal(signal.SIGTSTP, signal.SIG_IGN)  # ignore CTRL+Z
+    #     signal.signal(signal.SIGINT, signal.SIG_IGN)  # ignore CTRL+C
+
+    hostname = 'wikipedia.org'
+    dnsrecord = 'A'
+    count = 10
+    timeout = 5
+    verbose = False
+    dnsserver = '8.8.8.8'
+
+    try:
+        opts, args = getopt.getopt(sys.argv[1:], "qhc:s:t:w:v",
+                                   ["help", "output=", "count=", "server=", "quiet", "type=", "wait=", "verbose"])
+    except getopt.GetoptError as err:
+        # print help information and exit:
+        print(err)  # will print something like "option -a not recognized"
+        usage()
+        exit(2)
+
+    quiet = False
+    hn = [h for h in sys.argv[-1:] if not h.startswith('-')]
+    hostname = hn[0]
+
+    for o, a in opts:
+        if o in ("-h", "--help"):
+            usage()
+        elif o in ("-c", "--count"):
+            count = int(a)
+        elif o in ("-v", "--verbose"):
+            verbose = True
+        elif o in ("-s", "--server"):
+            dnsserver = a
+        elif o in ("-q", "--quiet"):
+            quiet = True
+            verbose = False
+        elif o in ("-w", "--wait"):
+            timeout = int(a)
+        elif o in ("-t", "--type"):
+            dnsrecord = a
+        else:
+            if a.startswith('-'):
+                print("unknown syntax: %s" % a)
+                usage()
+            else:
+                hostname = a
+
+    resolver = dns.resolver.Resolver()
+    resolver.nameservers.append(dnsserver)
+    resolver.timeout = timeout
+    resolver.lifetime = timeout
+    resolver.retry_servfail = 0
+
+    response_time = []
+
+    print("DNSPING %s: hostname=%s rdatatype=%s" % (dnsserver, hostname, dnsrecord))
+
+    for i in range(count):
+        try:
+            stime = time.time()
+            answers = resolver.query(hostname, dnsrecord)
+            etime = time.time()
+        except dns.resolver.NoNameservers:
+            if not quiet:
+                print("no response to dns request")
+            exit(1)
+        except dns.resolver.Timeout:
+            if not quiet:
+                print("request timeout")
+            pass
+        except dns.resolver.NoAnswer:
+            if not quiet:
+                print("invalid answer")
+            pass
+        else:
+            elapsed = (etime - stime) * 1000  # convert to milliseconds
+            response_time.append(elapsed)
+            if not quiet:
+                print(
+                        "%d bytes from %s: seq=%-3d time=%3.3f ms" % (
+                            len(str(answers.rrset)), dnsserver, i, elapsed))
+            if verbose:
+                print(answers.rrset)
+
+    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
+        r_stddev = stdev(response_time)
+    else:
+        r_min = 0
+        r_max = 0
+        r_avg = 0
+        r_stddev = 0
+
+    print('\n--- %s dnsping statistics ---' % dnsserver)
+    print('%d requests transmitted, %d responses received, %3.0f%% lost' % (r_sent, r_received, r_lost_percent))
+    print('min=%3.3f ms, avg=%3.3f ms, max=%3.3f ms, stddev=%3.3f ms' % (r_min, r_avg, r_max, r_stddev))
+
+
+if __name__ == '__main__':
+    main()