def stop_and_parse_result():
""" Terminates the pktgen process and parses the pktgen result. """
shared.run_ssh('pkill -2 pktgen_wrapper',
hostname=config.pktgen_host).wait()
time.sleep(2)
(state.pktgen_run_time, state.pktgen_sent_pkt_count) = _parse_result()
def add_rules(rule_count):
"""
Adds specified number of rules into the TCAM (table_id = 0). Ensures that
fewer than 8 rules are added every second. Returns the number of rules added
to the TCAM from this function call.
"""
initial_flow_count = len(dump_tables())
for flow_id in range(rule_count):
port = flow_id + 10000
p = shared.run_ssh(config.add_rule_cmd(config.new_rule(port)),
hostname=config.ofctl_ip, stdout=subprocess.PIPE,
verbose=False)
p.wait()
# Verifies the TCAM for every ten rules added.
if flow_id % 10 == 0:
assert len(dump_tables()) - initial_flow_count == flow_id + 1
sys.stdout.write('\radd_rules: %d left' % (rule_count - flow_id))
sys.stdout.flush()
print ''
return len(dump_tables()) - initial_flow_count
def dump_tables(filter='table_id=0'):
"""
Returns a list of rules in the TCAM (table_id = 0).
"""
p = shared.run_ssh(config.dump_flows_cmd,
hostname=config.ofctl_ip, stdout=subprocess.PIPE,
verbose=False)
return [line for line in p.stdout if line.find(filter) >= 0]
def reset_flow_table():
"""
Removes all entries from all the flow tables.
"""
p = shared.run_ssh(config.del_flow_cmd,
hostname=config.ofctl_ip)
p.wait()
# Let system stabilize.
time.sleep(4)
def send(pkt_count=56, pkt_size=1400, delay=0, flow_count=1):
"""
Sends packets. Returns a Popen handle.
"""
f = open('../script/pktgen_wrapper_template.sh')
pktgen_script = f.read()
f.close()
# Replace the place-holders in pktgen_wrapper.sh with actual parameters.
replacement_dict = {'[PKTGEN_PROC]': config.pktgen_proc,
'[PKTGEN_IFACE]': config.pktgen_iface,
'[PKT_COUNT]': str(pkt_count),
'[PKT_SIZE]': str(pkt_size),
'[DELAY]': str(delay),
'[MAX_PORT]': str((flow_count + 10000)),
'[SRC_IP]': config.source_ip_fake,
'[DST_IP]': config.dest_ip,
'[DST_MAC]': config.dest_mac
}
pktgen_script = _replace_string_with_dict(pktgen_script, replacement_dict)
f = open('/tmp/pktgen_wrapper.sh', 'w')
f.write(pktgen_script)
f.close()
# Copy the file to pktgen host's tmp.
p = shared.run_cmd('scp -q /tmp/pktgen_wrapper.sh ',
'root@', config.pktgen_host, ':/tmp; ',
'rm /tmp/pktgen_wrapper.sh')
p.wait()
# Execute the script remotely.
state.pktgen_run_time = state.pktgen_sent_pkt_count = None
return shared.run_ssh('chmod +x /tmp/pktgen_wrapper.sh; ',
'/tmp/pktgen_wrapper.sh',
hostname=config.pktgen_host)
def _parse_result():
"""
Parses the pktgen result file in /proc, extracts the actual run time (in
second) and packet count and returns them as a tuple.
We want to match the following line:
Result: OK: 8648151(c650366+d7997785) nsec, 87129 (1400byte,0frags)
[ ] <-exp time in us [ ] <- pkt sent
"""
p_proc = shared.run_ssh('cat ', config.pktgen_proc, config.pktgen_iface,
hostname=config.pktgen_host,
stdout=subprocess.PIPE)
result_regex = re.compile('OK: (\d+)\(.*\) nsec, (\d+) \(.*\)')
for line in p_proc.stdout:
r_obj = result_regex.search(line)
if r_obj:
print 'Parsing pktgen result:', line
return (int(r_obj.group(1)) / 1000000.0, int(r_obj.group(2)))
raise Exception('Unable to parse pktgen result.')
