启动 hostapd 失败 -- ACS：无法收集调查数据

Question 1

FWIW 我目前正在解决我认为类似的问题。我正在 RPi4 (2GB RAM) 上使用带有 hostapd + dnsmasq 的内置无线接口。当我手动指定通道时，它似乎工作正常，但是当我尝试自动选择最佳通道时，它会失败（有点无声地）。如果我启用大量调试日志记录，我可以看到以下输出，这表明测量调查数据的代码和将其连接到 hostapd 的部分之间存在问题。

为了代替更好的解决方案，我写了一个NodeJS用于选择频道号并将其发布的脚本这里。

配置概要

# cat /etc/hostapd/hostapd.conf
# This is the name of the WiFi interface we configured above
interface=wlan0

# (per RPi4 access-point instructions)
driver=nl80211

# This is the name of the network
ssid=MySSID

# Use 802.11g (2.4GHz)
hw_mode=g

# Channel number (IEEE 802.11)
# (default: 0, i.e., not set)
# Please note that some drivers do not use this value from hostapd and the
# channel will need to be configured separately with iwconfig.
#
# If CONFIG_ACS build option is enabled, the channel can be selected
# automatically at run time by setting channel=acs_survey or channel=0, both of
# which will enable the ACS survey based algorithm.
#
# Works fine when we set the channel manually
#channel=4
channel=acs_survey

# Enable 802.11n (doesn't seem to affect whether or not ACS works)
ieee80211n=1
#ieee80211n=0

# Disable Wifi MultiMedia
wmm_enabled=0

# Accept all MAC addresses
macaddr_acl=0

# Use WPA authentication
auth_algs=1

# Require clients to know the network name
ignore_broadcast_ssid=0

# Allow WPA1 or WPA2
wpa=3

# Use a pre-shared key
wpa_key_mgmt=WPA-PSK

# The network passphrase
wpa_passphrase=mypassphrase

# Default to (weak) TKIP for WPA1
wpa_pairwise=TKIP CCMP

# Use AES, instead of TKIP for RSN/WPA2
rsn_pairwise=CCMP


# hostapd event logger configuration
#
# Two output method: syslog and stdout (only usable if not forking to background).
#
# Module bitfield (ORed bitfield of modules that will be logged; -1 = all modules):
# bit 0 (1) = IEEE 802.11
# bit 1 (2) = IEEE 802.1X
# bit 2 (4) = RADIUS
# bit 3 (8) = WPA
# bit 4 (16) = driver interface
# bit 5 (32) = IAPP
# bit 6 (64) = MLME
#
# Levels (minimum value for logged events):
#  0 = verbose debugging
#  1 = debugging
#  2 = informational messages
#  3 = notification
#  4 = warning
#
logger_syslog=-1
logger_syslog_level=0
logger_stdout=-1
logger_stdout_level=0

输出

# hostapd -dd /etc/hostapd/hostapd.conf
random: getrandom() support available
Configuration file: /etc/hostapd/hostapd.conf
nl80211: Using driver-based roaming
nl80211: TDLS supported
nl80211: Supported cipher 00-0f-ac:1
nl80211: Supported cipher 00-0f-ac:5
nl80211: Supported cipher 00-0f-ac:2
nl80211: Supported cipher 00-0f-ac:4
nl80211: Supported cipher 00-0f-ac:6
nl80211: Using driver-based off-channel TX
nl80211: Supported vendor command: vendor_id=0x1018 subcmd=1
nl80211: Use separate P2P group interface (driver advertised support)
nl80211: Enable multi-channel concurrent (driver advertised support)
nl80211: use P2P_DEVICE support
nl80211: interface wlan0 in phy phy0
nl80211: Set mode ifindex 4 iftype 3 (AP)
nl80211: Setup AP(wlan0) - device_ap_sme=1 use_monitor=0
nl80211: Subscribe to mgmt frames with AP handle 0x5567d637a0 (device SME)
nl80211: Register frame type=0xd0 (WLAN_FC_STYPE_ACTION) nl_handle=0x5567d637a0 match=04
nl80211: Register frame type=0xd0 (WLAN_FC_STYPE_ACTION) nl_handle=0x5567d637a0 match=0501
nl80211: Register frame type=0xd0 (WLAN_FC_STYPE_ACTION) nl_handle=0x5567d637a0 match=0503
nl80211: Register frame type=0xd0 (WLAN_FC_STYPE_ACTION) nl_handle=0x5567d637a0 match=0504
nl80211: Register frame type=0xd0 (WLAN_FC_STYPE_ACTION) nl_handle=0x5567d637a0 match=06
nl80211: Register frame type=0xd0 (WLAN_FC_STYPE_ACTION) nl_handle=0x5567d637a0 match=08
nl80211: Register frame type=0xd0 (WLAN_FC_STYPE_ACTION) nl_handle=0x5567d637a0 match=09
nl80211: Register frame type=0xd0 (WLAN_FC_STYPE_ACTION) nl_handle=0x5567d637a0 match=0a
nl80211: Register frame type=0xd0 (WLAN_FC_STYPE_ACTION) nl_handle=0x5567d637a0 match=11
nl80211: Register frame type=0xd0 (WLAN_FC_STYPE_ACTION) nl_handle=0x5567d637a0 match=12
nl80211: Register frame type=0xd0 (WLAN_FC_STYPE_ACTION) nl_handle=0x5567d637a0 match=7f
nl80211: Enable Probe Request reporting nl_preq=0x5567d631d0
nl80211: Register frame type=0x40 (WLAN_FC_STYPE_PROBE_REQ) nl_handle=0x5567d631d0 match=
rfkill: initial event: idx=0 type=1 op=0 soft=0 hard=0
nl80211: Add own interface ifindex 4 (ifidx_reason -1)
nl80211: if_indices[16]: 4(-1)
phy: phy0
BSS count 1, BSSID mask 00:00:00:00:00:00 (0 bits)
nl80211: Regulatory information - country=00
nl80211: 2402-2472 @ 40 MHz 20 mBm
nl80211: 2457-2482 @ 20 MHz 20 mBm (no IR)
nl80211: 2474-2494 @ 20 MHz 20 mBm (no OFDM) (no IR)
nl80211: 5170-5250 @ 80 MHz 20 mBm (no IR)
nl80211: 5250-5330 @ 80 MHz 20 mBm (DFS) (no IR)
nl80211: 5490-5730 @ 160 MHz 20 mBm (DFS) (no IR)
nl80211: 5735-5835 @ 80 MHz 20 mBm (no IR)
nl80211: 57240-63720 @ 2160 MHz 0 mBm
nl80211: Added 802.11b mode based on 802.11g information
nl80211: Mode IEEE 802.11g: 2412 2417 2422 2427 2432 2437 2442 2447 2452 2457 2462 2467 2472 2484
nl80211: Mode IEEE 802.11a: 5170 5180 5190 5200 5210 5220 5230 5240 5260 5280 5300 5320 5500 5520 5540 5560 5580 5600 5620 5640 5660 5680 5700 5720 5745 5765 5785 5805 5825
nl80211: Mode IEEE 802.11b: 2412 2417 2422 2427 2432 2437 2442 2447 2452 2457 2462 2467 2472 2484
Allowed channel: mode=1 chan=1 freq=2412 MHz max_tx_power=20 dBm
Allowed channel: mode=1 chan=2 freq=2417 MHz max_tx_power=20 dBm
Allowed channel: mode=1 chan=3 freq=2422 MHz max_tx_power=20 dBm
Allowed channel: mode=1 chan=4 freq=2427 MHz max_tx_power=20 dBm
Allowed channel: mode=1 chan=5 freq=2432 MHz max_tx_power=20 dBm
Allowed channel: mode=1 chan=6 freq=2437 MHz max_tx_power=20 dBm
Allowed channel: mode=1 chan=7 freq=2442 MHz max_tx_power=20 dBm
Allowed channel: mode=1 chan=8 freq=2447 MHz max_tx_power=20 dBm
Allowed channel: mode=1 chan=9 freq=2452 MHz max_tx_power=20 dBm
Allowed channel: mode=1 chan=10 freq=2457 MHz max_tx_power=20 dBm
Allowed channel: mode=1 chan=11 freq=2462 MHz max_tx_power=20 dBm
Allowed channel: mode=1 chan=12 freq=2467 MHz max_tx_power=20 dBm
Allowed channel: mode=1 chan=13 freq=2472 MHz max_tx_power=20 dBm
Allowed channel: mode=1 chan=14 freq=2484 MHz max_tx_power=20 dBm
Allowed channel: mode=2 chan=34 freq=5170 MHz max_tx_power=3 dBm
Allowed channel: mode=2 chan=36 freq=5180 MHz max_tx_power=20 dBm
Allowed channel: mode=2 chan=38 freq=5190 MHz max_tx_power=20 dBm
Allowed channel: mode=2 chan=40 freq=5200 MHz max_tx_power=20 dBm
Allowed channel: mode=2 chan=42 freq=5210 MHz max_tx_power=20 dBm
Allowed channel: mode=2 chan=44 freq=5220 MHz max_tx_power=20 dBm
Allowed channel: mode=2 chan=46 freq=5230 MHz max_tx_power=20 dBm
Allowed channel: mode=2 chan=48 freq=5240 MHz max_tx_power=20 dBm
Allowed channel: mode=2 chan=52 freq=5260 MHz max_tx_power=20 dBm
Allowed channel: mode=2 chan=56 freq=5280 MHz max_tx_power=20 dBm
Allowed channel: mode=2 chan=60 freq=5300 MHz max_tx_power=20 dBm
Allowed channel: mode=2 chan=64 freq=5320 MHz max_tx_power=20 dBm
Allowed channel: mode=2 chan=100 freq=5500 MHz max_tx_power=20 dBm
Allowed channel: mode=2 chan=104 freq=5520 MHz max_tx_power=20 dBm
Allowed channel: mode=2 chan=108 freq=5540 MHz max_tx_power=20 dBm
Allowed channel: mode=2 chan=112 freq=5560 MHz max_tx_power=20 dBm
Allowed channel: mode=2 chan=116 freq=5580 MHz max_tx_power=20 dBm
Allowed channel: mode=2 chan=120 freq=5600 MHz max_tx_power=20 dBm
Allowed channel: mode=2 chan=124 freq=5620 MHz max_tx_power=20 dBm
Allowed channel: mode=2 chan=128 freq=5640 MHz max_tx_power=20 dBm
Allowed channel: mode=2 chan=132 freq=5660 MHz max_tx_power=20 dBm
Allowed channel: mode=2 chan=136 freq=5680 MHz max_tx_power=20 dBm
Allowed channel: mode=2 chan=140 freq=5700 MHz max_tx_power=20 dBm
Allowed channel: mode=2 chan=144 freq=5720 MHz max_tx_power=20 dBm
Allowed channel: mode=2 chan=149 freq=5745 MHz max_tx_power=20 dBm
Allowed channel: mode=2 chan=153 freq=5765 MHz max_tx_power=20 dBm
Allowed channel: mode=2 chan=157 freq=5785 MHz max_tx_power=20 dBm
Allowed channel: mode=2 chan=161 freq=5805 MHz max_tx_power=20 dBm
Allowed channel: mode=2 chan=165 freq=5825 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=1 freq=2412 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=2 freq=2417 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=3 freq=2422 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=4 freq=2427 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=5 freq=2432 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=6 freq=2437 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=7 freq=2442 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=8 freq=2447 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=9 freq=2452 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=10 freq=2457 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=11 freq=2462 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=12 freq=2467 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=13 freq=2472 MHz max_tx_power=20 dBm
Allowed channel: mode=0 chan=14 freq=2484 MHz max_tx_power=20 dBm
ACS: Automatic channel selection started, this may take a bit
ACS: Scanning 1 / 5
wlan0: nl80211: scan request
nl80211: Passive scan requested
nl80211: Scan frequency 2412 MHz
nl80211: Scan frequency 2417 MHz
nl80211: Scan frequency 2422 MHz
nl80211: Scan frequency 2427 MHz
nl80211: Scan frequency 2432 MHz
nl80211: Scan frequency 2437 MHz
nl80211: Scan frequency 2442 MHz
nl80211: Scan frequency 2447 MHz
nl80211: Scan frequency 2452 MHz
nl80211: Scan frequency 2457 MHz
nl80211: Scan frequency 2462 MHz
nl80211: Scan frequency 2467 MHz
nl80211: Scan frequency 2472 MHz
nl80211: Scan frequency 2484 MHz
Scan requested (ret=0) - scan timeout 10 seconds
wlan0: interface state UNINITIALIZED->ACS
wlan0: ACS-STARTED
Interface initialization will be completed in a callback (ACS)
ctrl_iface not configured!
nl80211: Event message available
nl80211: Drv Event 33 (NL80211_CMD_TRIGGER_SCAN) received for wlan0
wlan0: nl80211: Scan trigger
wlan0: Event SCAN_STARTED (46) received
Unknown event 46
RTM_NEWLINK: ifi_index=4 ifname=wlan0 wext ifi_family=0 ifi_flags=0x1003 ([UP])
nl80211: Event message available
nl80211: Drv Event 34 (NL80211_CMD_NEW_SCAN_RESULTS) received for wlan0
wlan0: nl80211: New scan results available
nl80211: Scan included frequencies: 2412 2417 2422 2427 2432 2437 2442 2447 2452 2457 2462 2467 2472 2484
wlan0: Event SCAN_RESULTS (3) received
ACS: Using survey based algorithm (acs_num_scans=5)
nl80211: Fetch survey data
wlan0: Event SURVEY (45) received
No survey data received
ACS: Scanning 2 / 5
wlan0: nl80211: scan request
nl80211: Passive scan requested
nl80211: Scan frequency 2412 MHz
nl80211: Scan frequency 2417 MHz
nl80211: Scan frequency 2422 MHz
nl80211: Scan frequency 2427 MHz
nl80211: Scan frequency 2432 MHz
nl80211: Scan frequency 2437 MHz
nl80211: Scan frequency 2442 MHz
nl80211: Scan frequency 2447 MHz
nl80211: Scan frequency 2452 MHz
nl80211: Scan frequency 2457 MHz
nl80211: Scan frequency 2462 MHz
nl80211: Scan frequency 2467 MHz
nl80211: Scan frequency 2472 MHz
nl80211: Scan frequency 2484 MHz
Scan requested (ret=0) - scan timeout 30 seconds
nl80211: Event message available
nl80211: Drv Event 33 (NL80211_CMD_TRIGGER_SCAN) received for wlan0
wlan0: nl80211: Scan trigger
wlan0: Event SCAN_STARTED (46) received
Unknown event 46
RTM_NEWLINK: ifi_index=4 ifname=wlan0 wext ifi_family=0 ifi_flags=0x1003 ([UP])
nl80211: Event message available
nl80211: Drv Event 34 (NL80211_CMD_NEW_SCAN_RESULTS) received for wlan0
wlan0: nl80211: New scan results available
nl80211: Scan included frequencies: 2412 2417 2422 2427 2432 2437 2442 2447 2452 2457 2462 2467 2472 2484
wlan0: Event SCAN_RESULTS (3) received
ACS: Using survey based algorithm (acs_num_scans=5)
nl80211: Fetch survey data
wlan0: Event SURVEY (45) received
No survey data received
ACS: Scanning 3 / 5
wlan0: nl80211: scan request
nl80211: Passive scan requested
nl80211: Scan frequency 2412 MHz
nl80211: Scan frequency 2417 MHz
nl80211: Scan frequency 2422 MHz
nl80211: Scan frequency 2427 MHz
nl80211: Scan frequency 2432 MHz
nl80211: Scan frequency 2437 MHz
nl80211: Scan frequency 2442 MHz
nl80211: Scan frequency 2447 MHz
nl80211: Scan frequency 2452 MHz
nl80211: Scan frequency 2457 MHz
nl80211: Scan frequency 2462 MHz
nl80211: Scan frequency 2467 MHz
nl80211: Scan frequency 2472 MHz
nl80211: Scan frequency 2484 MHz
Scan requested (ret=0) - scan timeout 30 seconds
nl80211: Event message available
nl80211: Drv Event 33 (NL80211_CMD_TRIGGER_SCAN) received for wlan0
wlan0: nl80211: Scan trigger
wlan0: Event SCAN_STARTED (46) received
Unknown event 46
RTM_NEWLINK: ifi_index=4 ifname=wlan0 wext ifi_family=0 ifi_flags=0x1003 ([UP])
nl80211: Event message available
nl80211: Drv Event 34 (NL80211_CMD_NEW_SCAN_RESULTS) received for wlan0
wlan0: nl80211: New scan results available
nl80211: Scan included frequencies: 2412 2417 2422 2427 2432 2437 2442 2447 2452 2457 2462 2467 2472 2484
wlan0: Event SCAN_RESULTS (3) received
ACS: Using survey based algorithm (acs_num_scans=5)
nl80211: Fetch survey data
wlan0: Event SURVEY (45) received
No survey data received
ACS: Scanning 4 / 5
wlan0: nl80211: scan request
nl80211: Passive scan requested
nl80211: Scan frequency 2412 MHz
nl80211: Scan frequency 2417 MHz
nl80211: Scan frequency 2422 MHz
nl80211: Scan frequency 2427 MHz
nl80211: Scan frequency 2432 MHz
nl80211: Scan frequency 2437 MHz
nl80211: Scan frequency 2442 MHz
nl80211: Scan frequency 2447 MHz
nl80211: Scan frequency 2452 MHz
nl80211: Scan frequency 2457 MHz
nl80211: Scan frequency 2462 MHz
nl80211: Scan frequency 2467 MHz
nl80211: Scan frequency 2472 MHz
nl80211: Scan frequency 2484 MHz
Scan requested (ret=0) - scan timeout 30 seconds
nl80211: Event message available
nl80211: Drv Event 33 (NL80211_CMD_TRIGGER_SCAN) received for wlan0
wlan0: nl80211: Scan trigger
wlan0: Event SCAN_STARTED (46) received
Unknown event 46
RTM_NEWLINK: ifi_index=4 ifname=wlan0 wext ifi_family=0 ifi_flags=0x1003 ([UP])
nl80211: Event message available
nl80211: Drv Event 34 (NL80211_CMD_NEW_SCAN_RESULTS) received for wlan0
wlan0: nl80211: New scan results available
nl80211: Scan included frequencies: 2412 2417 2422 2427 2432 2437 2442 2447 2452 2457 2462 2467 2472 2484
wlan0: Event SCAN_RESULTS (3) received
ACS: Using survey based algorithm (acs_num_scans=5)
nl80211: Fetch survey data
wlan0: Event SURVEY (45) received
No survey data received
ACS: Scanning 5 / 5
wlan0: nl80211: scan request
nl80211: Passive scan requested
nl80211: Scan frequency 2412 MHz
nl80211: Scan frequency 2417 MHz
nl80211: Scan frequency 2422 MHz
nl80211: Scan frequency 2427 MHz
nl80211: Scan frequency 2432 MHz
nl80211: Scan frequency 2437 MHz
nl80211: Scan frequency 2442 MHz
nl80211: Scan frequency 2447 MHz
nl80211: Scan frequency 2452 MHz
nl80211: Scan frequency 2457 MHz
nl80211: Scan frequency 2462 MHz
nl80211: Scan frequency 2467 MHz
nl80211: Scan frequency 2472 MHz
nl80211: Scan frequency 2484 MHz
Scan requested (ret=0) - scan timeout 30 seconds
nl80211: Event message available
nl80211: Drv Event 33 (NL80211_CMD_TRIGGER_SCAN) received for wlan0
wlan0: nl80211: Scan trigger
wlan0: Event SCAN_STARTED (46) received
Unknown event 46
nl80211: Event message available
nl80211: Drv Event 34 (NL80211_CMD_NEW_SCAN_RESULTS) received for wlan0
wlan0: nl80211: New scan results available
nl80211: Scan included frequencies: 2412 2417 2422 2427 2432 2437 2442 2447 2452 2457 2462 2467 2472 2484
wlan0: Event SCAN_RESULTS (3) received
ACS: Using survey based algorithm (acs_num_scans=5)
nl80211: Fetch survey data
wlan0: Event SURVEY (45) received
No survey data received
ACS: Trying survey-based ACS
ACS: Unable to collect survey data
ACS: All study options have failed
Interface initialization failed
wlan0: interface state ACS->DISABLED
wlan0: AP-DISABLED
ACS: Possibly channel configuration is invalid, please report this along with your config file.
ACS: Failed to start
wlan0: AP-DISABLED
wlan0: Deauthenticate all stations
nl80211: sta_remove -> DEL_STATION wlan0 ff:ff:ff:ff:ff:ff --> 0 (Success)
hostapd_free_hapd_data: Interface wlan0 wasn't started
hostapd_deinit_driver: driver=0x55587256e8 drv_priv=0x5567d5df30 -> hapd_deinit
nl80211: deinit ifname=wlan0 disabled_11b_rates=0
nl80211: Disable Probe Request reporting nl_preq=0x888888ddef5eb959
nl80211: Remove monitor interface: refcount=0
nl80211: Remove beacon (ifindex=4)
netlink: Operstate: ifindex=4 linkmode=0 (kernel-control), operstate=6 (IF_OPER_UP)
nl80211: Set mode ifindex 4 iftype 2 (STATION)
nl80211: Teardown AP(wlan0) - device_ap_sme=1 use_monitor=0
nl80211: Unsubscribe mgmt frames handle 0x888888ddef5ebf29 (AP teardown (dev SME))
hostapd_deinit_driver:bss[0]->drv_priv=0x5567d5df30
hostapd_cleanup_iface_partial(0x5567d5b980)
Interface wlan0 disabled
wlan0: interface state DISABLED->DISABLED
hostapd_interface_deinit_free(0x5567d5b980)
hostapd_interface_deinit_free: num_bss=1 conf->num_bss=1
hostapd_interface_deinit(0x5567d5b980)
wlan0: interface state DISABLED->DISABLED
hostapd_bss_deinit: deinit bss wlan0
wlan0: AP-DISABLED
hostapd_cleanup(hapd=0x5567d5ce80 (wlan0))
wlan0: CTRL-EVENT-TERMINATING
hostapd_free_hapd_data: Interface wlan0 wasn't started
hostapd_interface_deinit_free: driver=0x55587256e8 drv_priv=(nil) -> hapd_deinit
hostapd_interface_free(0x5567d5b980)
hostapd_interface_free: free hapd 0x5567d5ce80
hostapd_cleanup_iface(0x5567d5b980)
hostapd_cleanup_iface_partial(0x5567d5b980)
hostapd_cleanup_iface: free iface=0x5567d5b980

我能够使用iwlist wlan0 scanning或wavemon查看其他 AP 等

也可以看看：

Answer

FWIW 我目前正在解决我认为类似的问题。我正在 RPi4 (2GB RAM) 上使用带有 hostapd + dnsmasq 的内置无线接口。当我手动指定通道时，它似乎工作正常，但是当我尝试自动选择最佳通道时，它会失败（有点无声地）。如果我启用大量调试日志记录，我可以看到以下输出，这表明测量调查数据的代码和将其连接到 hostapd 的部分之间存在问题。