hostap/tests/hwsim/test_ap_tdls.py
Janusz Dziedzic 4a264a6fa1 tests: Pass full apdev to add_ap() function (5)
Pass the full apdev to the add_ap() function instead of just ifname.
This allows us to handle also remote hosts while we can check
apdev['hostname'], apdev['port'].

This step (5) converts the cases that use the start_ap_wpa2_psk() helper
function.

Signed-off-by: Janusz Dziedzic <janusz.dziedzic@tieto.com>
2016-04-03 22:46:14 +03:00

552 lines
21 KiB
Python

# TDLS tests
# Copyright (c) 2013-2014, Jouni Malinen <j@w1.fi>
#
# This software may be distributed under the terms of the BSD license.
# See README for more details.
import time
import logging
logger = logging.getLogger()
import subprocess
import hwsim_utils
from hostapd import HostapdGlobal
from hostapd import Hostapd
import hostapd
from utils import HwsimSkip, skip_with_fips
from wlantest import Wlantest
from test_ap_vht import vht_supported
def start_ap_wpa2_psk(ap):
params = hostapd.wpa2_params(ssid="test-wpa2-psk", passphrase="12345678")
return hostapd.add_ap(ap, params)
def connectivity(dev, hapd):
hwsim_utils.test_connectivity_sta(dev[0], dev[1])
hwsim_utils.test_connectivity(dev[0], hapd)
hwsim_utils.test_connectivity(dev[1], hapd)
def connect_2sta(dev, ssid, hapd):
dev[0].connect(ssid, psk="12345678", scan_freq="2412")
dev[1].connect(ssid, psk="12345678", scan_freq="2412")
connectivity(dev, hapd)
def connect_2sta_wpa2_psk(dev, hapd):
connect_2sta(dev, "test-wpa2-psk", hapd)
def connect_2sta_wpa_psk(dev, hapd):
connect_2sta(dev, "test-wpa-psk", hapd)
def connect_2sta_wpa_psk_mixed(dev, hapd):
dev[0].connect("test-wpa-mixed-psk", psk="12345678", proto="WPA",
scan_freq="2412")
dev[1].connect("test-wpa-mixed-psk", psk="12345678", proto="WPA2",
scan_freq="2412")
connectivity(dev, hapd)
def connect_2sta_wep(dev, hapd):
dev[0].connect("test-wep", key_mgmt="NONE", wep_key0='"hello"',
scan_freq="2412")
dev[1].connect("test-wep", key_mgmt="NONE", wep_key0='"hello"',
scan_freq="2412")
connectivity(dev, hapd)
def connect_2sta_open(dev, hapd, scan_freq="2412"):
dev[0].connect("test-open", key_mgmt="NONE", scan_freq=scan_freq)
dev[1].connect("test-open", key_mgmt="NONE", scan_freq=scan_freq)
connectivity(dev, hapd)
def wlantest_setup():
wt = Wlantest()
wt.flush()
wt.add_passphrase("12345678")
wt.add_wepkey("68656c6c6f")
def wlantest_tdls_packet_counters(bssid, addr0, addr1):
wt = Wlantest()
dl = wt.get_tdls_counter("valid_direct_link", bssid, addr0, addr1)
inv_dl = wt.get_tdls_counter("invalid_direct_link", bssid, addr0, addr1)
ap = wt.get_tdls_counter("valid_ap_path", bssid, addr0, addr1)
inv_ap = wt.get_tdls_counter("invalid_ap_path", bssid, addr0, addr1)
return [dl,inv_dl,ap,inv_ap]
def tdls_check_dl(sta0, sta1, bssid, addr0, addr1):
wt = Wlantest()
wt.tdls_clear(bssid, addr0, addr1)
hwsim_utils.test_connectivity_sta(sta0, sta1)
[dl,inv_dl,ap,inv_ap] = wlantest_tdls_packet_counters(bssid, addr0, addr1)
if dl == 0:
raise Exception("No valid frames through direct link")
if inv_dl > 0:
raise Exception("Invalid frames through direct link")
if ap > 0:
raise Exception("Unexpected frames through AP path")
if inv_ap > 0:
raise Exception("Invalid frames through AP path")
def tdls_check_ap(sta0, sta1, bssid, addr0, addr1):
wt = Wlantest()
wt.tdls_clear(bssid, addr0, addr1);
hwsim_utils.test_connectivity_sta(sta0, sta1)
[dl,inv_dl,ap,inv_ap] = wlantest_tdls_packet_counters(bssid, addr0, addr1)
if dl > 0:
raise Exception("Unexpected frames through direct link")
if inv_dl > 0:
raise Exception("Invalid frames through direct link")
if ap == 0:
raise Exception("No valid frames through AP path")
if inv_ap > 0:
raise Exception("Invalid frames through AP path")
def check_connectivity(sta0, sta1, hapd):
hwsim_utils.test_connectivity_sta(sta0, sta1)
hwsim_utils.test_connectivity(sta0, hapd)
hwsim_utils.test_connectivity(sta1, hapd)
def setup_tdls(sta0, sta1, ap, reverse=False, expect_fail=False):
logger.info("Setup TDLS")
hapd = hostapd.Hostapd(ap['ifname'])
check_connectivity(sta0, sta1, hapd)
bssid = ap['bssid']
addr0 = sta0.p2p_interface_addr()
addr1 = sta1.p2p_interface_addr()
wt = Wlantest()
wt.tdls_clear(bssid, addr0, addr1);
wt.tdls_clear(bssid, addr1, addr0);
sta0.tdls_setup(addr1)
time.sleep(1)
if expect_fail:
tdls_check_ap(sta0, sta1, bssid, addr0, addr1)
return
if reverse:
addr1 = sta0.p2p_interface_addr()
addr0 = sta1.p2p_interface_addr()
conf = wt.get_tdls_counter("setup_conf_ok", bssid, addr0, addr1);
if conf == 0:
raise Exception("No TDLS Setup Confirm (success) seen")
tdls_check_dl(sta0, sta1, bssid, addr0, addr1)
check_connectivity(sta0, sta1, hapd)
def teardown_tdls(sta0, sta1, ap, responder=False, wildcard=False):
logger.info("Teardown TDLS")
hapd = hostapd.Hostapd(ap['ifname'])
check_connectivity(sta0, sta1, hapd)
bssid = ap['bssid']
addr0 = sta0.p2p_interface_addr()
addr1 = sta1.p2p_interface_addr()
if responder:
sta1.tdls_teardown(addr0)
elif wildcard:
sta0.tdls_teardown("*")
else:
sta0.tdls_teardown(addr1)
time.sleep(1)
wt = Wlantest()
teardown = wt.get_tdls_counter("teardown", bssid, addr0, addr1);
if teardown == 0:
raise Exception("No TDLS Setup Teardown seen")
tdls_check_ap(sta0, sta1, bssid, addr0, addr1)
check_connectivity(sta0, sta1, hapd)
def check_tdls_link(sta0, sta1, connected=True):
addr0 = sta0.own_addr()
addr1 = sta1.own_addr()
status0 = sta0.tdls_link_status(addr1).rstrip()
status1 = sta1.tdls_link_status(addr0).rstrip()
logger.info("%s: %s" % (sta0.ifname, status0))
logger.info("%s: %s" % (sta1.ifname, status1))
if status0 != status1:
raise Exception("TDLS link status differs between stations")
if "status: connected" in status0:
if not connected:
raise Exception("Expected TDLS link status NOT to be connected")
else:
if connected:
raise Exception("Expected TDLS link status to be connected")
def test_ap_tdls_discovery(dev, apdev):
"""WPA2-PSK AP and two stations using TDLS discovery"""
hapd = start_ap_wpa2_psk(apdev[0])
wlantest_setup()
connect_2sta_wpa2_psk(dev, hapd)
dev[0].request("TDLS_DISCOVER " + dev[1].p2p_interface_addr())
time.sleep(0.2)
def test_ap_wpa2_tdls(dev, apdev):
"""WPA2-PSK AP and two stations using TDLS"""
hapd = start_ap_wpa2_psk(apdev[0])
wlantest_setup()
connect_2sta_wpa2_psk(dev, hapd)
setup_tdls(dev[0], dev[1], apdev[0])
teardown_tdls(dev[0], dev[1], apdev[0])
setup_tdls(dev[1], dev[0], apdev[0])
#teardown_tdls(dev[0], dev[1], apdev[0])
def test_ap_wpa2_tdls_concurrent_init(dev, apdev):
"""Concurrent TDLS setup initiation"""
hapd = start_ap_wpa2_psk(apdev[0])
wlantest_setup()
connect_2sta_wpa2_psk(dev, hapd)
dev[0].request("SET tdls_testing 0x80")
setup_tdls(dev[1], dev[0], apdev[0], reverse=True)
def test_ap_wpa2_tdls_concurrent_init2(dev, apdev):
"""Concurrent TDLS setup initiation (reverse)"""
hapd = start_ap_wpa2_psk(apdev[0])
wlantest_setup()
connect_2sta_wpa2_psk(dev, hapd)
dev[1].request("SET tdls_testing 0x80")
setup_tdls(dev[0], dev[1], apdev[0])
def test_ap_wpa2_tdls_decline_resp(dev, apdev):
"""Decline TDLS Setup Response"""
hapd = start_ap_wpa2_psk(apdev[0])
wlantest_setup()
connect_2sta_wpa2_psk(dev, hapd)
dev[1].request("SET tdls_testing 0x200")
setup_tdls(dev[1], dev[0], apdev[0], expect_fail=True)
def test_ap_wpa2_tdls_long_lifetime(dev, apdev):
"""TDLS with long TPK lifetime"""
hapd = start_ap_wpa2_psk(apdev[0])
wlantest_setup()
connect_2sta_wpa2_psk(dev, hapd)
dev[1].request("SET tdls_testing 0x40")
setup_tdls(dev[1], dev[0], apdev[0])
def test_ap_wpa2_tdls_long_frame(dev, apdev):
"""TDLS with long setup/teardown frames"""
hapd = start_ap_wpa2_psk(apdev[0])
wlantest_setup()
connect_2sta_wpa2_psk(dev, hapd)
dev[0].request("SET tdls_testing 0x1")
dev[1].request("SET tdls_testing 0x1")
setup_tdls(dev[1], dev[0], apdev[0])
teardown_tdls(dev[1], dev[0], apdev[0])
setup_tdls(dev[0], dev[1], apdev[0])
def test_ap_wpa2_tdls_reneg(dev, apdev):
"""Renegotiate TDLS link"""
hapd = start_ap_wpa2_psk(apdev[0])
wlantest_setup()
connect_2sta_wpa2_psk(dev, hapd)
setup_tdls(dev[1], dev[0], apdev[0])
setup_tdls(dev[0], dev[1], apdev[0])
def test_ap_wpa2_tdls_wrong_lifetime_resp(dev, apdev):
"""Incorrect TPK lifetime in TDLS Setup Response"""
hapd = start_ap_wpa2_psk(apdev[0])
wlantest_setup()
connect_2sta_wpa2_psk(dev, hapd)
dev[1].request("SET tdls_testing 0x10")
setup_tdls(dev[0], dev[1], apdev[0], expect_fail=True)
def test_ap_wpa2_tdls_diff_rsnie(dev, apdev):
"""TDLS with different RSN IEs"""
hapd = start_ap_wpa2_psk(apdev[0])
wlantest_setup()
connect_2sta_wpa2_psk(dev, hapd)
dev[1].request("SET tdls_testing 0x2")
setup_tdls(dev[1], dev[0], apdev[0])
teardown_tdls(dev[1], dev[0], apdev[0])
def test_ap_wpa2_tdls_wrong_tpk_m2_mic(dev, apdev):
"""Incorrect MIC in TDLS Setup Response"""
hapd = start_ap_wpa2_psk(apdev[0])
wlantest_setup()
connect_2sta_wpa2_psk(dev, hapd)
dev[0].request("SET tdls_testing 0x800")
addr0 = dev[0].p2p_interface_addr()
dev[1].tdls_setup(addr0)
time.sleep(1)
def test_ap_wpa2_tdls_wrong_tpk_m3_mic(dev, apdev):
"""Incorrect MIC in TDLS Setup Confirm"""
hapd = start_ap_wpa2_psk(apdev[0])
wlantest_setup()
connect_2sta_wpa2_psk(dev, hapd)
dev[1].request("SET tdls_testing 0x800")
addr0 = dev[0].p2p_interface_addr()
dev[1].tdls_setup(addr0)
time.sleep(1)
def test_ap_wpa_tdls(dev, apdev):
"""WPA-PSK AP and two stations using TDLS"""
skip_with_fips(dev[0])
hapd = hostapd.add_ap(apdev[0],
hostapd.wpa_params(ssid="test-wpa-psk",
passphrase="12345678"))
wlantest_setup()
connect_2sta_wpa_psk(dev, hapd)
setup_tdls(dev[0], dev[1], apdev[0])
teardown_tdls(dev[0], dev[1], apdev[0])
setup_tdls(dev[1], dev[0], apdev[0])
def test_ap_wpa_mixed_tdls(dev, apdev):
"""WPA+WPA2-PSK AP and two stations using TDLS"""
skip_with_fips(dev[0])
hapd = hostapd.add_ap(apdev[0],
hostapd.wpa_mixed_params(ssid="test-wpa-mixed-psk",
passphrase="12345678"))
wlantest_setup()
connect_2sta_wpa_psk_mixed(dev, hapd)
setup_tdls(dev[0], dev[1], apdev[0])
teardown_tdls(dev[0], dev[1], apdev[0])
setup_tdls(dev[1], dev[0], apdev[0])
def test_ap_wep_tdls(dev, apdev):
"""WEP AP and two stations using TDLS"""
hapd = hostapd.add_ap(apdev[0],
{ "ssid": "test-wep", "wep_key0": '"hello"' })
wlantest_setup()
connect_2sta_wep(dev, hapd)
setup_tdls(dev[0], dev[1], apdev[0])
teardown_tdls(dev[0], dev[1], apdev[0])
setup_tdls(dev[1], dev[0], apdev[0])
def test_ap_open_tdls(dev, apdev):
"""Open AP and two stations using TDLS"""
hapd = hostapd.add_ap(apdev[0], { "ssid": "test-open" })
wlantest_setup()
connect_2sta_open(dev, hapd)
setup_tdls(dev[0], dev[1], apdev[0])
teardown_tdls(dev[0], dev[1], apdev[0])
setup_tdls(dev[1], dev[0], apdev[0])
teardown_tdls(dev[1], dev[0], apdev[0], wildcard=True)
def test_ap_wpa2_tdls_bssid_mismatch(dev, apdev):
"""TDLS failure due to BSSID mismatch"""
try:
ssid = "test-wpa2-psk"
passphrase = "12345678"
params = hostapd.wpa2_params(ssid=ssid, passphrase=passphrase)
params['bridge'] = 'ap-br0'
hapd = hostapd.add_ap(apdev[0], params)
hostapd.add_ap(apdev[1], params)
wlantest_setup()
subprocess.call(['brctl', 'setfd', 'ap-br0', '0'])
subprocess.call(['ip', 'link', 'set', 'dev', 'ap-br0', 'up'])
dev[0].connect(ssid, psk=passphrase, scan_freq="2412",
bssid=apdev[0]['bssid'])
dev[1].connect(ssid, psk=passphrase, scan_freq="2412",
bssid=apdev[1]['bssid'])
hwsim_utils.test_connectivity_sta(dev[0], dev[1])
hwsim_utils.test_connectivity_iface(dev[0], hapd, "ap-br0")
hwsim_utils.test_connectivity_iface(dev[1], hapd, "ap-br0")
addr0 = dev[0].p2p_interface_addr()
dev[1].tdls_setup(addr0)
time.sleep(1)
hwsim_utils.test_connectivity_sta(dev[0], dev[1])
finally:
subprocess.call(['ip', 'link', 'set', 'dev', 'ap-br0', 'down'])
subprocess.call(['brctl', 'delbr', 'ap-br0'])
def test_ap_wpa2_tdls_responder_teardown(dev, apdev):
"""TDLS teardown from responder with WPA2-PSK AP"""
hapd = start_ap_wpa2_psk(apdev[0])
wlantest_setup()
connect_2sta_wpa2_psk(dev, hapd)
setup_tdls(dev[0], dev[1], apdev[0])
teardown_tdls(dev[0], dev[1], apdev[0], responder=True)
def test_ap_open_tdls_vht(dev, apdev):
"""Open AP and two stations using TDLS"""
params = { "ssid": "test-open",
"country_code": "DE",
"hw_mode": "a",
"channel": "36",
"ieee80211n": "1",
"ieee80211ac": "1",
"ht_capab": "",
"vht_capab": "",
"vht_oper_chwidth": "0",
"vht_oper_centr_freq_seg0_idx": "0" }
try:
hapd = hostapd.add_ap(apdev[0], params)
wlantest_setup()
connect_2sta_open(dev, hapd, scan_freq="5180")
setup_tdls(dev[0], dev[1], apdev[0])
teardown_tdls(dev[0], dev[1], apdev[0])
setup_tdls(dev[1], dev[0], apdev[0])
teardown_tdls(dev[1], dev[0], apdev[0], wildcard=True)
finally:
dev[0].request("DISCONNECT")
dev[1].request("DISCONNECT")
if hapd:
hapd.request("DISABLE")
subprocess.call(['iw', 'reg', 'set', '00'])
dev[0].flush_scan_cache()
dev[1].flush_scan_cache()
def test_ap_open_tdls_vht80(dev, apdev):
"""Open AP and two stations using TDLS with VHT 80"""
params = { "ssid": "test-open",
"country_code": "US",
"hw_mode": "a",
"channel": "36",
"ht_capab": "[HT40+]",
"ieee80211n": "1",
"ieee80211ac": "1",
"vht_capab": "",
"vht_oper_chwidth": "1",
"vht_oper_centr_freq_seg0_idx": "42" }
try:
hapd = None
hapd = hostapd.add_ap(apdev[0], params)
wlantest_setup()
connect_2sta_open(dev, hapd, scan_freq="5180")
sig = dev[0].request("SIGNAL_POLL").splitlines()
if "WIDTH=80 MHz" not in sig:
raise Exception("Unexpected SIGNAL_POLL value(2): " + str(sig))
setup_tdls(dev[0], dev[1], apdev[0])
for i in range(10):
check_connectivity(dev[0], dev[1], hapd)
for i in range(2):
cmd = subprocess.Popen(['iw', dev[0].ifname, 'station', 'dump'],
stdout=subprocess.PIPE)
res = cmd.stdout.read()
cmd.stdout.close()
logger.info("Station dump on dev[%d]:\n%s" % (i, res))
except Exception, e:
if isinstance(e, Exception) and str(e) == "AP startup failed":
if not vht_supported():
raise HwsimSkip("80/160 MHz channel not supported in regulatory information")
raise
finally:
dev[0].request("DISCONNECT")
dev[1].request("DISCONNECT")
if hapd:
hapd.request("DISABLE")
subprocess.call(['iw', 'reg', 'set', '00'])
dev[0].flush_scan_cache()
dev[1].flush_scan_cache()
def test_ap_open_tdls_vht80plus80(dev, apdev):
"""Open AP and two stations using TDLS with VHT 80+80"""
params = { "ssid": "test-open",
"country_code": "US",
"hw_mode": "a",
"channel": "36",
"ht_capab": "[HT40+]",
"ieee80211n": "1",
"ieee80211ac": "1",
"vht_capab": "",
"vht_oper_chwidth": "3",
"vht_oper_centr_freq_seg0_idx": "42",
"vht_oper_centr_freq_seg1_idx": "155" }
try:
hapd = None
hapd = hostapd.add_ap(apdev[0], params)
wlantest_setup()
connect_2sta_open(dev, hapd, scan_freq="5180")
sig = dev[0].request("SIGNAL_POLL").splitlines()
if "FREQUENCY=5180" not in sig:
raise Exception("Unexpected SIGNAL_POLL value(1): " + str(sig))
if "WIDTH=80+80 MHz" not in sig:
raise Exception("Unexpected SIGNAL_POLL value(2): " + str(sig))
if "CENTER_FRQ1=5210" not in sig:
raise Exception("Unexpected SIGNAL_POLL value(3): " + str(sig))
if "CENTER_FRQ2=5775" not in sig:
raise Exception("Unexpected SIGNAL_POLL value(4): " + str(sig))
setup_tdls(dev[0], dev[1], apdev[0])
for i in range(10):
check_connectivity(dev[0], dev[1], hapd)
for i in range(2):
cmd = subprocess.Popen(['iw', dev[0].ifname, 'station', 'dump'],
stdout=subprocess.PIPE)
res = cmd.stdout.read()
cmd.stdout.close()
logger.info("Station dump on dev[%d]:\n%s" % (i, res))
except Exception, e:
if isinstance(e, Exception) and str(e) == "AP startup failed":
if not vht_supported():
raise HwsimSkip("80/160 MHz channel not supported in regulatory information")
raise
finally:
dev[0].request("DISCONNECT")
dev[1].request("DISCONNECT")
if hapd:
hapd.request("DISABLE")
subprocess.call(['iw', 'reg', 'set', '00'])
dev[0].flush_scan_cache()
dev[1].flush_scan_cache()
def test_ap_open_tdls_vht160(dev, apdev):
"""Open AP and two stations using TDLS with VHT 160"""
params = { "ssid": "test-open",
"country_code": "ZA",
"hw_mode": "a",
"channel": "104",
"ht_capab": "[HT40-]",
"ieee80211n": "1",
"ieee80211ac": "1",
"vht_oper_chwidth": "2",
"vht_oper_centr_freq_seg0_idx": "114" }
try:
hapd = None
hapd = hostapd.add_ap(apdev[0], params, wait_enabled=False)
ev = hapd.wait_event(["AP-ENABLED"], timeout=2)
if not ev:
cmd = subprocess.Popen(["iw", "reg", "get"], stdout=subprocess.PIPE)
reg = cmd.stdout.readlines()
for r in reg:
if "5490" in r and "DFS" in r:
raise HwsimSkip("ZA regulatory rule did not have DFS requirement removed")
raise Exception("AP setup timed out")
wlantest_setup()
connect_2sta_open(dev, hapd, scan_freq="5520")
sig = dev[0].request("SIGNAL_POLL").splitlines()
if "WIDTH=160 MHz" not in sig:
raise Exception("Unexpected SIGNAL_POLL value(2): " + str(sig))
setup_tdls(dev[0], dev[1], apdev[0])
for i in range(10):
check_connectivity(dev[0], dev[1], hapd)
for i in range(2):
cmd = subprocess.Popen(['iw', dev[0].ifname, 'station', 'dump'],
stdout=subprocess.PIPE)
res = cmd.stdout.read()
cmd.stdout.close()
logger.info("Station dump on dev[%d]:\n%s" % (i, res))
except Exception, e:
if isinstance(e, Exception) and str(e) == "AP startup failed":
if not vht_supported():
raise HwsimSkip("80/160 MHz channel not supported in regulatory information")
raise
finally:
dev[0].request("DISCONNECT")
dev[1].request("DISCONNECT")
if hapd:
hapd.request("DISABLE")
subprocess.call(['iw', 'reg', 'set', '00'])
dev[0].flush_scan_cache()
dev[1].flush_scan_cache()
def test_tdls_chan_switch(dev, apdev):
"""Open AP and two stations using TDLS"""
flags = int(dev[0].get_driver_status_field('capa.flags'), 16)
if flags & 0x800000000 == 0:
raise HwsimSkip("Driver does not support TDLS channel switching")
hapd = hostapd.add_ap(apdev[0], { "ssid": "test-open" })
connect_2sta_open(dev, hapd)
setup_tdls(dev[0], dev[1], apdev[0])
if "OK" not in dev[0].request("TDLS_CHAN_SWITCH " + dev[1].own_addr() + " 81 2462"):
raise Exception("Failed to enable TDLS channel switching")
if "OK" not in dev[0].request("TDLS_CANCEL_CHAN_SWITCH " + dev[1].own_addr()):
raise Exception("Could not disable TDLS channel switching")
if "FAIL" not in dev[0].request("TDLS_CANCEL_CHAN_SWITCH " + dev[1].own_addr()):
raise Exception("TDLS_CANCEL_CHAN_SWITCH accepted even though channel switching was already disabled")
def test_ap_tdls_link_status(dev, apdev):
"""Check TDLS link status between two stations"""
hapd = start_ap_wpa2_psk(apdev[0])
wlantest_setup()
connect_2sta_wpa2_psk(dev, hapd)
check_tdls_link(dev[0], dev[1], connected=False)
setup_tdls(dev[0], dev[1], apdev[0])
check_tdls_link(dev[0], dev[1], connected=True)
teardown_tdls(dev[0], dev[1], apdev[0])
check_tdls_link(dev[0], dev[1], connected=False)
if "FAIL" not in dev[0].request("TDLS_LINK_STATUS foo"):
raise Exception("Unexpected TDLS_LINK_STATUS response for invalid argument")