tests: hitless restart test

This test verifies that an IVS started with the --hitless flag waits until it
receives a bsn_takeover message before revalidating the kernel flowtable.

This is the first non-OFTest here. OFTest isn't designed to do things like
killing and restarting the IVS daemon, so we needed something different. We'll
probably add more tests like this in the future and factor out some of the
netns code into a library.

tests/hitless.py

@@ -0,0 +1,109 @@
+#!/usr/bin/env python
+"""
+This test verifies that an IVS started with the --hitless flag waits until it
+receives a bsn_takeover message before revalidating the kernel flowtable.
+"""
+import subprocess
+import logging
+import time
+import os
+import signal
+import sys
+
+sys.path.insert(1, "submodules/loxigen-artifacts/pyloxi")
+import loxi.of14 as ofp
+import loxi.connection
+from loxi.pp import pp
+
+IVS = "./targets/ivs/build/gcc-local/bin/ivs"
+
+logging.basicConfig(level=logging.INFO)
+
+logfile = file("ivs.log", "w")
+ivs = None
+
+def start_ivs():
+    global ivs
+    logging.info("Starting IVS")
+    ivs = subprocess.Popen(
+        [IVS, '-v', '-l', '127.0.0.1:6634', '--hitless', '-V', '1.3'],
+        stdout=logfile, stderr=logfile)
+
+def insert_flows():
+    logging.info("Inserting flows")
+    cxn = loxi.connection.connect("127.0.0.1", port=6634)
+    port_descs = cxn.transact_multipart(ofp.message.port_desc_stats_request())
+    port_numbers = { x.name: x.port_no for x in port_descs }
+
+    cxn.send(ofp.message.flow_add(
+        match=ofp.match([
+            ofp.oxm.in_port(port_numbers["test1"])]),
+        instructions=[
+            ofp.instruction.apply_actions([
+                ofp.action.output(port_numbers["test2"])])]))
+    cxn.send(ofp.message.flow_add(
+        match=ofp.match([
+            ofp.oxm.in_port(port_numbers["test2"])]),
+        instructions=[
+            ofp.instruction.apply_actions([
+                ofp.action.output(port_numbers["test1"])])]))
+    cxn.send(ofp.message.bsn_takeover())
+    cxn.transact(ofp.message.barrier_request())
+
+def cmd(*args):
+    logging.debug("Running %s", ' '.join(args))
+    subprocess.check_call(args)
+
+
+subprocess.call(["ivs-ctl", "del-dp"])
+
+try:
+    if os.path.exists("/var/run/netns/test1"):
+        cmd("ip", "netns", "delete", "test1")
+
+    if os.path.exists("/var/run/netns/test2"):
+        cmd("ip", "netns", "delete", "test2")
+
+    start_ivs()
+
+    cmd("ip", "netns", "add", "test1")
+    cmd("ip", "netns", "add", "test2")
+
+    cmd("ip", "link", "add", "name", "test1", "type", "veth", "peer", "name", "test1-peer")
+    cmd("ip", "link", "set", "test1-peer", "up", "netns", "test1", "name", "eth0")
+    cmd("ip", "netns", "exec", "test1", "ip", "addr", "add", "dev", "eth0", "192.168.248.1/24")
+
+    cmd("ip", "link", "add", "name", "test2", "type", "veth", "peer", "name", "test2-peer")
+    cmd("ip", "link", "set", "test2-peer", "up", "netns", "test2", "name", "eth0")
+    cmd("ip", "netns", "exec", "test2", "ip", "addr", "add", "dev", "eth0", "192.168.248.2/24")
+
+    cmd("ivs-ctl", "add-port", "test1")
+    cmd("ivs-ctl", "add-port", "test2")
+
+    insert_flows()
+
+    logging.info("Normal ping")
+    cmd("ip", "netns", "exec", "test1", "ping", "-c", "10", "-i", "0.1", "192.168.248.2")
+    ivs.kill()
+
+    logging.info("Pinging while IVS is dead")
+    cmd("ip", "netns", "exec", "test1", "ping", "-c", "10", "-i", "0.1", "192.168.248.2")
+
+    start_ivs()
+
+    logging.info("Pinging after IVS has restarted but before takeover")
+    cmd("ip", "netns", "exec", "test1", "ping", "-c", "10", "-i", "0.1", "192.168.248.2")
+
+    insert_flows()
+
+    logging.info("Pinging after takeover")
+    cmd("ip", "netns", "exec", "test1", "ping", "-c", "10", "-i", "0.1", "192.168.248.2")
+finally:
+    if ivs:
+        ivs.kill()
+
+    if os.path.exists("/var/run/netns/test1"):
+        cmd("ip", "netns", "delete", "test1")
+
+    if os.path.exists("/var/run/netns/test2"):
+        cmd("ip", "netns", "delete", "test2")