krackattacks/tests/hwsim/test_scan.py

# Scanning tests
# Copyright (c) 2013, 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 hostapd

def check_scan(dev, params, other_started=False):
    if not other_started:
        dev.dump_monitor()
    id = dev.request("SCAN " + params)
    if "FAIL" in id:
        raise Exception("Failed to start scan")
    id = int(id)

    if other_started:
        ev = dev.wait_event(["CTRL-EVENT-SCAN-STARTED"])
        if ev is None:
            raise Exception("Other scan did not start")
        if "id=" + str(id) in ev:
            raise Exception("Own scan id unexpectedly included in start event")

        ev = dev.wait_event(["CTRL-EVENT-SCAN-RESULTS"])
        if ev is None:
            raise Exception("Other scan did not complete")
        if "id=" + str(id) in ev:
            raise Exception("Own scan id unexpectedly included in completed event")

    ev = dev.wait_event(["CTRL-EVENT-SCAN-STARTED"])
    if ev is None:
        raise Exception("Scan did not start")
    if "id=" + str(id) not in ev:
        raise Exception("Scan id not included in start event")

    ev = dev.wait_event(["CTRL-EVENT-SCAN-RESULTS"])
    if ev is None:
        raise Exception("Scan did not complete")
    if "id=" + str(id) not in ev:
        raise Exception("Scan id not included in completed event")

def test_scan(dev, apdev):
    """Control interface behavior on scan parameters"""
    hostapd.add_ap(apdev[0]['ifname'], { "ssid": "test-scan" })
    bssid = apdev[0]['bssid']

    logger.info("Full scan")
    check_scan(dev[0], "use_id=1")

    logger.info("Limited channel scan")
    check_scan(dev[0], "freq=2412-2462,5180 use_id=1")
    if int(dev[0].get_bss(bssid)['age']) > 1:
        raise Exception("Unexpectedly old BSS entry")

    # wait long enough to allow next scans to be verified not to find the AP
    time.sleep(2)

    logger.info("Passive single-channel scan")
    check_scan(dev[0], "freq=2457 passive=1 use_id=1")
    logger.info("Active single-channel scan")
    check_scan(dev[0], "freq=2452 passive=0 use_id=1")
    if int(dev[0].get_bss(bssid)['age']) < 2:
        raise Exception("Unexpectedly updated BSS entry")

    logger.info("Active single-channel scan on AP's operating channel")
    check_scan(dev[0], "freq=2412 passive=0 use_id=1")
    if int(dev[0].get_bss(bssid)['age']) > 1:
        raise Exception("Unexpectedly old BSS entry")

def test_scan_only(dev, apdev):
    """Control interface behavior on scan parameters with type=only"""
    hostapd.add_ap(apdev[0]['ifname'], { "ssid": "test-scan" })
    bssid = apdev[0]['bssid']

    logger.info("Full scan")
    check_scan(dev[0], "type=only use_id=1")

    logger.info("Limited channel scan")
    check_scan(dev[0], "type=only freq=2412-2462,5180 use_id=1")
    if int(dev[0].get_bss(bssid)['age']) > 1:
        raise Exception("Unexpectedly old BSS entry")

    # wait long enough to allow next scans to be verified not to find the AP
    time.sleep(2)

    logger.info("Passive single-channel scan")
    check_scan(dev[0], "type=only freq=2457 passive=1 use_id=1")
    logger.info("Active single-channel scan")
    check_scan(dev[0], "type=only freq=2452 passive=0 use_id=1")
    if int(dev[0].get_bss(bssid)['age']) < 2:
        raise Exception("Unexpectedly updated BSS entry")

    logger.info("Active single-channel scan on AP's operating channel")
    check_scan(dev[0], "type=only freq=2412 passive=0 use_id=1")
    if int(dev[0].get_bss(bssid)['age']) > 1:
        raise Exception("Unexpectedly old BSS entry")

def test_scan_external_trigger(dev, apdev):
    """Avoid operations during externally triggered scan"""
    hostapd.add_ap(apdev[0]['ifname'], { "ssid": "test-scan" })
    bssid = apdev[0]['bssid']
    subprocess.call(['sudo', 'iw', dev[0].ifname, 'scan', 'trigger'])
    check_scan(dev[0], "use_id=1", other_started=True)

def test_scan_bss_expiration_count(dev, apdev):
    """BSS entry expiration based on scan results without match"""
    if "FAIL" not in dev[0].request("BSS_EXPIRE_COUNT 0"):
        raise Exception("Invalid BSS_EXPIRE_COUNT accepted")
    if "OK" not in dev[0].request("BSS_EXPIRE_COUNT 2"):
        raise Exception("BSS_EXPIRE_COUNT failed")
    hapd = hostapd.add_ap(apdev[0]['ifname'], { "ssid": "test-scan" })
    bssid = apdev[0]['bssid']
    dev[0].scan(freq="2412", only_new=True)
    if bssid not in dev[0].request("SCAN_RESULTS"):
        raise Exception("BSS not found in initial scan")
    hapd.request("DISABLE")
    dev[0].scan(freq="2412", only_new=True)
    if bssid not in dev[0].request("SCAN_RESULTS"):
        raise Exception("BSS not found in first scan without match")
    dev[0].scan(freq="2412", only_new=True)
    if bssid in dev[0].request("SCAN_RESULTS"):
        raise Exception("BSS found after two scans without match")

def test_scan_bss_expiration_age(dev, apdev):
    """BSS entry expiration based on age"""
    try:
        if "FAIL" not in dev[0].request("BSS_EXPIRE_AGE COUNT 9"):
            raise Exception("Invalid BSS_EXPIRE_AGE accepted")
        if "OK" not in dev[0].request("BSS_EXPIRE_AGE 10"):
            raise Exception("BSS_EXPIRE_AGE failed")
        hapd = hostapd.add_ap(apdev[0]['ifname'], { "ssid": "test-scan" })
        bssid = apdev[0]['bssid']
        dev[0].scan(freq="2412")
        if bssid not in dev[0].request("SCAN_RESULTS"):
            raise Exception("BSS not found in initial scan")
        hapd.request("DISABLE")
        logger.info("Waiting for BSS entry to expire")
        time.sleep(7)
        if bssid not in dev[0].request("SCAN_RESULTS"):
            raise Exception("BSS expired too quickly")
        ev = dev[0].wait_event(["CTRL-EVENT-BSS-REMOVED"], timeout=15)
        if ev is None:
            raise Exception("BSS entry expiration timed out")
        if bssid in dev[0].request("SCAN_RESULTS"):
            raise Exception("BSS not removed after expiration time")
    finally:
        dev[0].request("BSS_EXPIRE_AGE 180")