blob: c7721fd2954d41c9996801f7d3127ccb8c76629a [file] [log] [blame]
import sys
import copy
try:
import scapy.all as scapy
except:
try:
import scapy as scapy
except:
sys.exit("Need to install scapy for packet parsing")
import oftest.controller as controller
import oftest.cstruct as ofp
import oftest.message as message
import oftest.dataplane as dataplane
import oftest.action as action
import oftest.parse as parse
import logging
import types
global skipped_test_count
skipped_test_count = 0
# Some useful defines
IP_ETHERTYPE = 0x800
TCP_PROTOCOL = 0x6
UDP_PROTOCOL = 0x11
def clear_switch(parent, port_list, logger):
"""
Clear the switch configuration
@param parent Object implementing controller and assert equal
@param logger Logging object
"""
for port in port_list:
clear_port_config(parent, port, logger)
delete_all_flows(parent.controller, logger)
def delete_all_flows(ctrl, logger):
"""
Delete all flows on the switch
@param ctrl The controller object for the test
@param logger Logging object
"""
logger.info("Deleting all flows")
msg = message.flow_mod()
msg.match.wildcards = ofp.OFPFW_ALL
msg.out_port = ofp.OFPP_NONE
msg.command = ofp.OFPFC_DELETE
msg.buffer_id = 0xffffffff
return ctrl.message_send(msg)
def clear_port_config(parent, port, logger):
"""
Clear the port configuration (currently only no flood setting)
@param parent Object implementing controller and assert equal
@param logger Logging object
"""
rv = port_config_set(parent.controller, port,
0, ofp.OFPPC_NO_FLOOD, logger)
self.assertEqual(rv, 0, "Failed to reset port config")
def simple_tcp_packet(pktlen=100,
dl_dst='00:01:02:03:04:05',
dl_src='00:06:07:08:09:0a',
dl_vlan_enable=False,
dl_vlan=0,
dl_vlan_pcp=0,
dl_vlan_cfi=0,
ip_src='192.168.0.1',
ip_dst='192.168.0.2',
ip_tos=0,
tcp_sport=1234,
tcp_dport=80
):
"""
Return a simple dataplane TCP packet
Supports a few parameters:
@param len Length of packet in bytes w/o CRC
@param dl_dst Destinatino MAC
@param dl_src Source MAC
@param dl_vlan_enable True if the packet is with vlan, False otherwise
@param dl_vlan VLAN ID
@param dl_vlan_pcp VLAN priority
@param ip_src IP source
@param ip_dst IP destination
@param ip_tos IP ToS
@param tcp_dport TCP destination port
@param ip_sport TCP source port
Generates a simple TCP request. Users
shouldn't assume anything about this packet other than that
it is a valid ethernet/IP/TCP frame.
"""
# Note Dot1Q.id is really CFI
if (dl_vlan_enable):
pkt = scapy.Ether(dst=dl_dst, src=dl_src)/ \
scapy.Dot1Q(prio=dl_vlan_pcp, id=dl_vlan_cfi, vlan=dl_vlan)/ \
scapy.IP(src=ip_src, dst=ip_dst, tos=ip_tos)/ \
scapy.TCP(sport=tcp_sport, dport=tcp_dport)
else:
pkt = scapy.Ether(dst=dl_dst, src=dl_src)/ \
scapy.IP(src=ip_src, dst=ip_dst, tos=ip_tos)/ \
scapy.TCP(sport=tcp_sport, dport=tcp_dport)
pkt = pkt/("D" * (pktlen - len(pkt)))
return pkt
def simple_icmp_packet(pktlen=60,
dl_dst='00:01:02:03:04:05',
dl_src='00:06:07:08:09:0a',
dl_vlan_enable=False,
dl_vlan=0,
dl_vlan_pcp=0,
ip_src='192.168.0.1',
ip_dst='192.168.0.2',
ip_tos=0,
icmp_type=8,
icmp_code=0
):
"""
Return a simple ICMP packet
Supports a few parameters:
@param len Length of packet in bytes w/o CRC
@param dl_dst Destinatino MAC
@param dl_src Source MAC
@param dl_vlan_enable True if the packet is with vlan, False otherwise
@param dl_vlan VLAN ID
@param dl_vlan_pcp VLAN priority
@param ip_src IP source
@param ip_dst IP destination
@param ip_tos IP ToS
@param icmp_type ICMP type
@param icmp_code ICMP code
Generates a simple ICMP ECHO REQUEST. Users
shouldn't assume anything about this packet other than that
it is a valid ethernet/ICMP frame.
"""
if (dl_vlan_enable):
pkt = scapy.Ether(dst=dl_dst, src=dl_src)/ \
scapy.Dot1Q(prio=dl_vlan_pcp, id=0, vlan=dl_vlan)/ \
scapy.IP(src=ip_src, dst=ip_dst, tos=ip_tos)/ \
scapy.ICMP(type=icmp_type, code=icmp_code)
else:
pkt = scapy.Ether(dst=dl_dst, src=dl_src)/ \
scapy.IP(src=ip_src, dst=ip_dst, tos=ip_tos)/ \
scapy.ICMP(type=icmp_type, code=icmp_code)
pkt = pkt/("0" * (pktlen - len(pkt)))
return pkt
def do_barrier(ctrl):
b = message.barrier_request()
ctrl.transact(b)
def port_config_get(controller, port_no, logger):
"""
Get a port's configuration
Gets the switch feature configuration and grabs one port's
configuration
@returns (hwaddr, config, advert) The hwaddress, configuration and
advertised values
"""
request = message.features_request()
reply, pkt = controller.transact(request, timeout=2)
logger.debug(reply.show())
if reply is None:
logger.warn("Get feature request failed")
return None, None, None
for idx in range(len(reply.ports)):
if reply.ports[idx].port_no == port_no:
return (reply.ports[idx].hw_addr, reply.ports[idx].config,
reply.ports[idx].advertised)
logger.warn("Did not find port number for port config")
return None, None, None
def port_config_set(controller, port_no, config, mask, logger):
"""
Set the port configuration according the given parameters
Gets the switch feature configuration and updates one port's
configuration value according to config and mask
"""
logger.info("Setting port " + str(port_no) + " to config " + str(config))
request = message.features_request()
reply, pkt = controller.transact(request, timeout=2)
if reply is None:
return -1
logger.debug(reply.show())
for idx in range(len(reply.ports)):
if reply.ports[idx].port_no == port_no:
break
if idx >= len(reply.ports):
return -1
mod = message.port_mod()
mod.port_no = port_no
mod.hw_addr = reply.ports[idx].hw_addr
mod.config = config
mod.mask = mask
mod.advertise = reply.ports[idx].advertised
rv = controller.message_send(mod)
return rv
def receive_pkt_check(dataplane, pkt, yes_ports, no_ports, assert_if, logger,
config):
"""
Check for proper receive packets across all ports
@param dataplane The dataplane object
@param pkt Expected packet; may be None if yes_ports is empty
@param yes_ports Set or list of ports that should recieve packet
@param no_ports Set or list of ports that should not receive packet
@param assert_if Object that implements assertXXX
"""
exp_pkt_arg = None
if config and config["relax"]:
exp_pkt_arg = pkt
for ofport in yes_ports:
logger.debug("Checking for pkt on port " + str(ofport))
(rcv_port, rcv_pkt, pkt_time) = dataplane.poll(
port_number=ofport, timeout=1, exp_pkt=exp_pkt_arg)
assert_if.assertTrue(rcv_pkt is not None,
"Did not receive pkt on " + str(ofport))
assert_if.assertEqual(str(pkt), str(rcv_pkt),
"Response packet does not match send packet " +
"on port " + str(ofport))
for ofport in no_ports:
logger.debug("Negative check for pkt on port " + str(ofport))
(rcv_port, rcv_pkt, pkt_time) = dataplane.poll(
port_number=ofport, timeout=1, exp_pkt=exp_pkt_arg)
assert_if.assertTrue(rcv_pkt is None,
"Unexpected pkt on port " + str(ofport))
def receive_pkt_verify(parent, egr_port, exp_pkt):
"""
Receive a packet and verify it matches an expected value
parent must implement dataplane, assertTrue and assertEqual
"""
exp_pkt_arg = None
if parent.config["relax"]:
exp_pkt_arg = exp_pkt
(rcv_port, rcv_pkt, pkt_time) = parent.dataplane.poll(port_number=egr_port,
timeout=1,
exp_pkt=exp_pkt_arg)
if rcv_pkt is None:
parent.logger.error("ERROR: No packet received from " + str(egr_port))
parent.assertTrue(rcv_pkt is not None,
"Did not receive packet port " + str(egr_port))
parent.logger.debug("Packet len " + str(len(rcv_pkt)) + " in on " +
str(rcv_port))
if str(exp_pkt) != str(rcv_pkt):
parent.logger.error("ERROR: Packet match failed.")
parent.logger.debug("Expected len " + str(len(exp_pkt)) + ": "
+ str(exp_pkt).encode('hex'))
parent.logger.debug("Received len " + str(len(rcv_pkt)) + ": "
+ str(rcv_pkt).encode('hex'))
parent.assertEqual(str(exp_pkt), str(rcv_pkt),
"Packet match error on port " + str(egr_port))
def match_verify(parent, req_match, res_match):
"""
Verify flow matches agree; if they disagree, report where
parent must implement assertEqual
Use str() to ensure content is compared and not pointers
"""
parent.assertEqual(req_match.wildcards, res_match.wildcards,
'Match failed: wildcards: ' + hex(req_match.wildcards) +
" != " + hex(res_match.wildcards))
parent.assertEqual(req_match.in_port, res_match.in_port,
'Match failed: in_port: ' + str(req_match.in_port) +
" != " + str(res_match.in_port))
parent.assertEqual(str(req_match.dl_src), str(res_match.dl_src),
'Match failed: dl_src: ' + str(req_match.dl_src) +
" != " + str(res_match.dl_src))
parent.assertEqual(str(req_match.dl_dst), str(res_match.dl_dst),
'Match failed: dl_dst: ' + str(req_match.dl_dst) +
" != " + str(res_match.dl_dst))
parent.assertEqual(req_match.dl_vlan, res_match.dl_vlan,
'Match failed: dl_vlan: ' + str(req_match.dl_vlan) +
" != " + str(res_match.dl_vlan))
parent.assertEqual(req_match.dl_vlan_pcp, res_match.dl_vlan_pcp,
'Match failed: dl_vlan_pcp: ' +
str(req_match.dl_vlan_pcp) + " != " +
str(res_match.dl_vlan_pcp))
parent.assertEqual(req_match.dl_type, res_match.dl_type,
'Match failed: dl_type: ' + str(req_match.dl_type) +
" != " + str(res_match.dl_type))
if (not(req_match.wildcards & ofp.OFPFW_DL_TYPE)
and (req_match.dl_type == IP_ETHERTYPE)):
parent.assertEqual(req_match.nw_tos, res_match.nw_tos,
'Match failed: nw_tos: ' + str(req_match.nw_tos) +
" != " + str(res_match.nw_tos))
parent.assertEqual(req_match.nw_proto, res_match.nw_proto,
'Match failed: nw_proto: ' + str(req_match.nw_proto) +
" != " + str(res_match.nw_proto))
parent.assertEqual(req_match.nw_src, res_match.nw_src,
'Match failed: nw_src: ' + str(req_match.nw_src) +
" != " + str(res_match.nw_src))
parent.assertEqual(req_match.nw_dst, res_match.nw_dst,
'Match failed: nw_dst: ' + str(req_match.nw_dst) +
" != " + str(res_match.nw_dst))
if (not(req_match.wildcards & ofp.OFPFW_NW_PROTO)
and ((req_match.nw_proto == TCP_PROTOCOL)
or (req_match.nw_proto == UDP_PROTOCOL))):
parent.assertEqual(req_match.tp_src, res_match.tp_src,
'Match failed: tp_src: ' +
str(req_match.tp_src) +
" != " + str(res_match.tp_src))
parent.assertEqual(req_match.tp_dst, res_match.tp_dst,
'Match failed: tp_dst: ' +
str(req_match.tp_dst) +
" != " + str(res_match.tp_dst))
def flow_removed_verify(parent, request=None, pkt_count=-1, byte_count=-1):
"""
Receive a flow removed msg and verify it matches expected
@params parent Must implement controller, assertEqual
@param pkt_count If >= 0, verify packet count
@param byte_count If >= 0, verify byte count
"""
(response, raw) = parent.controller.poll(ofp.OFPT_FLOW_REMOVED, 2)
parent.assertTrue(response is not None, 'No flow removed message received')
if request is None:
return
parent.assertEqual(request.cookie, response.cookie,
"Flow removed cookie error: " +
hex(request.cookie) + " != " + hex(response.cookie))
req_match = request.match
res_match = response.match
verifyMatchField(req_match, res_match)
if (req_match.wildcards != 0):
parent.assertEqual(request.priority, response.priority,
'Flow remove prio mismatch: ' +
str(request,priority) + " != " +
str(response.priority))
parent.assertEqual(response.reason, ofp.OFPRR_HARD_TIMEOUT,
'Flow remove reason is not HARD TIMEOUT:' +
str(response.reason))
if pkt_count >= 0:
parent.assertEqual(response.packet_count, pkt_count,
'Flow removed failed, packet count: ' +
str(response.packet_count) + " != " +
str(pkt_count))
if byte_count >= 0:
parent.assertEqual(response.byte_count, byte_count,
'Flow removed failed, byte count: ' +
str(response.byte_count) + " != " +
str(byte_count))
def flow_msg_create(parent, pkt, ing_port=None, action_list=None, wildcards=0,
egr_port=None, egr_queue=None, check_expire=False, in_band=True):
"""
Create a flow message
Match on packet with given wildcards.
See flow_match_test for other parameter descriptoins
@param egr_queue if not None, make the output an enqueue action
@param in_band if True, do not wildcard ingress port
"""
match = parse.packet_to_flow_match(pkt)
parent.assertTrue(match is not None, "Flow match from pkt failed")
if in_band:
wildcards &= ~ofp.OFPFW_IN_PORT
match.wildcards = wildcards
match.in_port = ing_port
request = message.flow_mod()
request.match = match
request.buffer_id = 0xffffffff
if check_expire:
request.flags |= ofp.OFPFF_SEND_FLOW_REM
request.hard_timeout = 1
if action_list is not None:
for act in action_list:
parent.logger.debug("Adding action " + act.show())
rv = request.actions.add(act)
parent.assertTrue(rv, "Could not add action" + act.show())
# Set up output/enqueue action if directed
if egr_queue is not None:
parent.assertTrue(egr_port is not None, "Egress port not set")
act = action.action_enqueue()
act.port = egr_port
act.queue_id = egr_queue
rv = request.actions.add(act)
parent.assertTrue(rv, "Could not add enqueue action " +
str(egr_port) + " Q: " + str(egr_queue))
elif egr_port is not None:
act = action.action_output()
act.port = egr_port
rv = request.actions.add(act)
parent.assertTrue(rv, "Could not add output action " + str(egr_port))
parent.logger.debug(request.show())
return request
def flow_msg_install(parent, request, clear_table=True):
"""
Install a flow mod message in the switch
@param parent Must implement controller, assertEqual, assertTrue
@param request The request, all set to go
@param clear_table If true, clear the flow table before installing
"""
if clear_table:
parent.logger.debug("Clear flow table")
rc = delete_all_flows(parent.controller, parent.logger)
parent.assertEqual(rc, 0, "Failed to delete all flows")
do_barrier(parent.controller)
parent.logger.debug("Insert flow")
rv = parent.controller.message_send(request)
parent.assertTrue(rv != -1, "Error installing flow mod")
do_barrier(parent.controller)
def flow_match_test_port_pair(parent, ing_port, egr_port, wildcards=0,
dl_vlan=-1, pkt=None, exp_pkt=None,
action_list=None, check_expire=False):
"""
Flow match test on single TCP packet
Run test with packet through switch from ing_port to egr_port
See flow_match_test for parameter descriptions
"""
parent.logger.info("Pkt match test: " + str(ing_port) + " to " + str(egr_port))
parent.logger.debug(" WC: " + hex(wildcards) + " vlan: " + str(dl_vlan) +
" expire: " + str(check_expire))
if pkt is None:
pkt = simple_tcp_packet(dl_vlan_enable=(dl_vlan >= 0), dl_vlan=dl_vlan)
request = flow_msg_create(parent, pkt, ing_port=ing_port,
wildcards=wildcards, egr_port=egr_port,
action_list=action_list)
flow_msg_install(parent, request)
parent.logger.debug("Send packet: " + str(ing_port) + " to " + str(egr_port))
parent.dataplane.send(ing_port, str(pkt))
if exp_pkt is None:
exp_pkt = pkt
receive_pkt_verify(parent, egr_port, exp_pkt)
if check_expire:
#@todo Not all HW supports both pkt and byte counters
flow_removed_verify(parent, request, pkt_count=1, byte_count=len(pkt))
def flow_match_test(parent, port_map, wildcards=0, dl_vlan=-1, pkt=None,
exp_pkt=None, action_list=None, check_expire=False,
max_test=0):
"""
Run flow_match_test_port_pair on all port pairs
@param max_test If > 0 no more than this number of tests are executed.
@param parent Must implement controller, dataplane, assertTrue, assertEqual
and logger
@param pkt If not None, use this packet for ingress
@param wildcards For flow match entry
@param dl_vlan If not -1, and pkt is None, create a pkt w/ VLAN tag
@param exp_pkt If not None, use this as the expected output pkt; els use pkt
@param action_list Additional actions to add to flow mod
@param check_expire Check for flow expiration message
"""
of_ports = port_map.keys()
of_ports.sort()
parent.assertTrue(len(of_ports) > 1, "Not enough ports for test")
test_count = 0
for ing_idx in range(len(of_ports)):
ingress_port = of_ports[ing_idx]
for egr_idx in range(len(of_ports)):
if egr_idx == ing_idx:
continue
egress_port = of_ports[egr_idx]
flow_match_test_port_pair(parent, ingress_port, egress_port,
wildcards=wildcards, dl_vlan=dl_vlan,
pkt=pkt, exp_pkt=exp_pkt,
action_list=action_list,
check_expire=check_expire)
test_count += 1
if (max_test > 0) and (test_count > max_test):
parent.logger.info("Ran " + str(test_count) + " tests; exiting")
return
def test_param_get(config, key, default=None):
"""
Return value passed via test-params if present
@param config The configuration structure for OFTest
@param key The lookup key
@param default Default value to use if not found
If the pair 'key=val' appeared in the string passed to --test-params
on the command line, return val (as interpreted by exec). Otherwise
return default value.
"""
try:
exec config["test_params"]
except:
return default
s = "val = " + str(key)
try:
exec s
return val
except:
return default
def action_generate(parent, field_to_mod, mod_field_vals):
"""
Create an action to modify the field indicated in field_to_mod
@param parent Must implement, assertTrue
@param field_to_mod The field to modify as a string name
@param mod_field_vals Hash of values to use for modified values
"""
act = None
if field_to_mod in ['pktlen']:
return None
if field_to_mod == 'dl_dst':
act = action.action_set_dl_dst()
act.dl_addr = parse.parse_mac(mod_field_vals['dl_dst'])
elif field_to_mod == 'dl_src':
act = action.action_set_dl_src()
act.dl_addr = parse.parse_mac(mod_field_vals['dl_src'])
elif field_to_mod == 'dl_vlan_enable':
if not mod_field_vals['dl_vlan_enable']: # Strip VLAN tag
act = action.action_strip_vlan()
# Add VLAN tag is handled by dl_vlan field
# Will return None in this case
elif field_to_mod == 'dl_vlan':
act = action.action_set_vlan_vid()
act.vlan_vid = mod_field_vals['dl_vlan']
elif field_to_mod == 'dl_vlan_pcp':
act = action.action_set_vlan_pcp()
act.vlan_pcp = mod_field_vals['dl_vlan_pcp']
elif field_to_mod == 'ip_src':
act = action.action_set_nw_src()
act.nw_addr = parse.parse_ip(mod_field_vals['ip_src'])
elif field_to_mod == 'ip_dst':
act = action.action_set_nw_dst()
act.nw_addr = parse.parse_ip(mod_field_vals['ip_dst'])
elif field_to_mod == 'ip_tos':
act = action.action_set_nw_tos()
act.nw_tos = mod_field_vals['ip_tos']
elif field_to_mod == 'tcp_sport':
act = action.action_set_tp_src()
act.tp_port = mod_field_vals['tcp_sport']
elif field_to_mod == 'tcp_dport':
act = action.action_set_tp_dst()
act.tp_port = mod_field_vals['tcp_dport']
else:
parent.assertTrue(0, "Unknown field to modify: " + str(field_to_mod))
return act
def pkt_action_setup(parent, start_field_vals={}, mod_field_vals={},
mod_fields={}, check_test_params=False):
"""
Set up the ingress and expected packet and action list for a test
@param parent Must implement, assertTrue, config hash and logger
@param start_field_values Field values to use for ingress packet (optional)
@param mod_field_values Field values to use for modified packet (optional)
@param mod_fields The list of fields to be modified by the switch in the test.
@params check_test_params If True, will check the parameters vid, add_vlan
and strip_vlan from the command line.
Returns a triple: pkt-to-send, expected-pkt, action-list
"""
new_actions = []
base_pkt_params = {}
base_pkt_params['pktlen'] = 100
base_pkt_params['dl_dst'] = '00:DE:F0:12:34:56'
base_pkt_params['dl_src'] = '00:23:45:67:89:AB'
base_pkt_params['dl_vlan_enable'] = False
base_pkt_params['dl_vlan'] = 2
base_pkt_params['dl_vlan_pcp'] = 0
base_pkt_params['ip_src'] = '192.168.0.1'
base_pkt_params['ip_dst'] = '192.168.0.2'
base_pkt_params['ip_tos'] = 0
base_pkt_params['tcp_sport'] = 1234
base_pkt_params['tcp_dport'] = 80
for keyname in start_field_vals.keys():
base_pkt_params[keyname] = start_field_vals[keyname]
mod_pkt_params = {}
mod_pkt_params['pktlen'] = 100
mod_pkt_params['dl_dst'] = '00:21:0F:ED:CB:A9'
mod_pkt_params['dl_src'] = '00:ED:CB:A9:87:65'
mod_pkt_params['dl_vlan_enable'] = False
mod_pkt_params['dl_vlan'] = 3
mod_pkt_params['dl_vlan_pcp'] = 7
mod_pkt_params['ip_src'] = '10.20.30.40'
mod_pkt_params['ip_dst'] = '50.60.70.80'
mod_pkt_params['ip_tos'] = 0xf0
mod_pkt_params['tcp_sport'] = 4321
mod_pkt_params['tcp_dport'] = 8765
for keyname in mod_field_vals.keys():
mod_pkt_params[keyname] = mod_field_vals[keyname]
# Check for test param modifications
strip = False
if check_test_params:
add_vlan = test_param_get(parent.config, 'add_vlan')
strip_vlan = test_param_get(parent.config, 'strip_vlan')
vid = test_param_get(parent.config, 'vid')
if add_vlan and strip_vlan:
parent.assertTrue(0, "Add and strip VLAN both specified")
if vid:
base_pkt_params['dl_vlan_enable'] = True
base_pkt_params['dl_vlan'] = vid
if 'dl_vlan' in mod_fields:
mod_pkt_params['dl_vlan'] = vid + 1
if add_vlan:
base_pkt_params['dl_vlan_enable'] = False
mod_pkt_params['dl_vlan_enable'] = True
mod_pkt_params['pktlen'] = base_pkt_params['pktlen'] + 4
mod_fields.append('pktlen')
mod_fields.append('dl_vlan_enable')
if 'dl_vlan' not in mod_fields:
mod_fields.append('dl_vlan')
elif strip_vlan:
base_pkt_params['dl_vlan_enable'] = True
mod_pkt_params['dl_vlan_enable'] = False
mod_pkt_params['pktlen'] = base_pkt_params['pktlen'] - 4
mod_fields.append('dl_vlan_enable')
mod_fields.append('pktlen')
# Build the ingress packet
ingress_pkt = simple_tcp_packet(**base_pkt_params)
# Build the expected packet, modifying the indicated fields
for item in mod_fields:
base_pkt_params[item] = mod_pkt_params[item]
act = action_generate(parent, item, mod_pkt_params)
if act:
new_actions.append(act)
expected_pkt = simple_tcp_packet(**base_pkt_params)
return (ingress_pkt, expected_pkt, new_actions)
# Generate a simple "drop" flow mod
# If in_band is true, then only drop from first test port
def flow_mod_gen(port_map, in_band):
request = message.flow_mod()
request.match.wildcards = ofp.OFPFW_ALL
if in_band:
request.match.wildcards = ofp.OFPFW_ALL - ofp.OFPFW_IN_PORT
for of_port, ifname in port_map.items(): # Grab first port
break
request.match.in_port = of_port
request.buffer_id = 0xffffffff
return request
def skip_message_emit(parent, s):
"""
Print out a 'skipped' message to stderr
@param s The string to print out to the log file
@param parent Must implement config and logger objects
"""
global skipped_test_count
skipped_test_count += 1
parent.logger.info("Skipping: " + s)
if parent.config["dbg_level"] < logging.WARNING:
sys.stderr.write("(skipped) ")
else:
sys.stderr.write("(S)")