utilities/ovs-pipegen.py

   1 #! /usr/bin/env python
   2 # Copyright (c) 2013, 2014, 2015 Nicira, Inc.
   3 #
   4 # Licensed under the Apache License, Version 2.0 (the "License");
   5 # you may not use this file except in compliance with the License.
   6 # You may obtain a copy of the License at:
   7 #
   8 #     http://www.apache.org/licenses/LICENSE-2.0
   9 #
  10 # Unless required by applicable law or agreed to in writing, software
  11 # distributed under the License is distributed on an "AS IS" BASIS,
  12 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13 # See the License for the specific language governing permissions and
  14 # limitations under the License.
  15
  16 import argparse
  17 import random
  18 import sys
  19 import textwrap
  20
  21
  22 def flow_str(stage, match, action, priority=32768):
  23     mtd_match = "metadata=%d" % stage
  24     if match:
  25         mtd_match += "," + match
  26
  27     return "priority=%d %s,actions=%s" % (priority, mtd_match, action)
  28
  29
  30 def resubmit(nxt):
  31     return "load:%d->OXM_OF_METADATA[],resubmit(,0)" % nxt
  32
  33
  34 def rand_ip_mask():
  35     return ("%d.%d.%d.%d" % (random.randint(0, 255), random.randint(0, 255),
  36                              random.randint(0, 255), random.randint(0, 255)),
  37             random.choice([8, 16, 24, 32]))
  38
  39
  40 def rand_bool():
  41     return bool(random.randint(0, 1))
  42
  43
  44 def l2(stage, action):
  45     mac = ["%x" % random.randint(0, 2 ** 8 - 1) for x in range(6)]
  46     mac = [x.zfill(2) for x in mac]
  47     mac = ":".join(mac)
  48     return flow_str(stage, "dl_dst=%s" % mac, action)
  49
  50
  51 def l3(stage, action):
  52     ip, mask = rand_ip_mask()
  53     return flow_str(stage, "ip,ip_dst=%s/%d" % (ip, mask), action,
  54                     priority=mask)
  55
  56
  57 def l4(stage, action):
  58     match = "tcp"
  59
  60     if rand_bool():
  61         match += ",ip_src=%s/%d" % rand_ip_mask()
  62
  63     if rand_bool():
  64         match += ",ip_dst=%s/%d" % rand_ip_mask()
  65
  66     src_dst = "tp_src" if rand_bool() else "tp_dst"
  67     match += ",%s=%d" % (src_dst, random.randint(1024, 2 ** 16 - 1))
  68     return flow_str(stage, match, action)
  69
  70
  71 def pipeline(size):
  72     pipeline = [l2, l3, l4, l2]
  73
  74     flows = []
  75     for stage in range(len(pipeline)):
  76         action = resubmit(stage + 1)
  77         flows += [pipeline[stage](stage, action) for _ in range(size)]
  78         flows.append(flow_str(stage, "", action, priority=1))
  79
  80     flows.append(flow_str(len(pipeline), "", "in_port"))
  81
  82     for f in flows:
  83         print(f)
  84
  85
  86 def main():
  87     description = textwrap.dedent(
  88         """
  89         Generate a test OpenFlow pipeline.
  90
  91         Open vSwitch relies heavily on flow caching to get good performance for
  92         packet processing.  While on average, this produces good results,
  93         performance is heavily depedent on the slow path OpenFlow tables, and
  94         how they're translated into datapath megaflows.  For this reason, when
  95         doing performance testing it's important to run with "realistic"
  96         OpenFlow tables to ensure results will stand up in the real world.
  97
  98         This script generates a simple OpenFlow pipeline intended to simulate
  99         realistic network virtualization workloads.  All traffic received is
 100         run through a series of OpenFlow tables designed to simulate a logical
 101         switch, router, and firewall, before forwarded back on the in_port.
 102         """)
 103
 104     epilog = textwrap.dedent(
 105         """
 106         typical usage:
 107           ovs-ofctl del-flows bridge \\
 108           && %s | ovs-ofctl add-flows bridge - \\
 109           && ovs-ofctl dump-flows bridge
 110         """ % sys.argv[0])
 111
 112     parser = argparse.ArgumentParser(description=description, epilog=epilog,
 113             formatter_class=argparse.RawDescriptionHelpFormatter)
 114     parser.add_argument("--size", dest="size", default=1000,
 115                         help="Size (rules) of each OpenFlow table.")
 116     args = parser.parse_args()
 117
 118     pipeline(int(args.size))
 119
 120
 121 if __name__ == "__main__":
 122     main()