This is a regression test to verify the proper behavior of IP ID generation

code.  It will push 200000 packets, then report back what the min and max
periods it saw for different IDs were.

tools/regression/netinet/ip_id_period/ip_id_period.py

@@ -0,0 +1,76 @@
+# Copyright (C) 2008 Michael J. Silbersack.  All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 1. Redistributions of source code must retain the above copyright
+#    notice unmodified, this list of conditions, and the following
+#    disclaimer.
+# 2. 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 AUTHOR ``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 AUTHOR 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.
+#
+# $FreeBSD$
+#
+# This is a regression test to verify the proper behavior of IP ID generation
+# code.  It will push 200000 packets, then report back what the min and max
+# periods it saw for different IDs were.
+
+import os
+import signal
+import subprocess
+import time
+
+if os.path.exists('results.pcap'):
+    os.remove('results.pcap')
+tcpdump = subprocess.Popen('tcpdump -n -i lo0 -w results.pcap icmp', shell=True)
+time.sleep(1) # Give tcpdump time to start
+
+os.system('sysctl net.inet.icmp.icmplim=0')
+os.system('ping -q -i .001 -c 100000 127.0.0.1')
+
+time.sleep(3) # Give tcpdump time to catch up
+os.kill(tcpdump.pid, signal.SIGTERM)
+
+os.system('tcpdump -n -v -r results.pcap > results.txt')
+
+id_lastseen = {}
+id_minperiod = {}
+
+count = 0
+for line in open('results.txt').readlines():
+    id = int(line.split(' id ')[1].split(',')[0])
+    if id_lastseen.has_key(id):
+        period = count - id_lastseen[id]
+        if not id_minperiod.has_key(id) or period < id_minperiod[id]:
+            id_minperiod[id] = period
+    id_lastseen[id] = count
+    count += 1
+
+sorted_minperiod = zip(*reversed(zip(*id_minperiod.items())))
+sorted_minperiod.sort()
+
+print "Lowest 10 ID periods detected:"
+x = 0
+while x < 10:
+    id_tuple = sorted_minperiod.pop(0)
+    print "id: %d period: %d" % (id_tuple[1], id_tuple[0])
+    x += 1
+
+print "Highest 10 ID periods detected:"
+x = 0
+while x < 10:
+    id_tuple = sorted_minperiod.pop()
+    print "id: %d period: %d" % (id_tuple[1], id_tuple[0])
+    x += 1