Wireless Utilities

As explained at wireless.overview the Linux IEEE 802.11 subsystem is fragmented. The available tools depend entirely on the driver associated with your wireless device. These have an API different from that of Ethernet devices because the specifications of IEEE 802.11 regulate quite precisely the communications process. Therefore it makes sense to not implement these requirements in each driver but only once for all drivers, and also because there is the problem of diverging frequency regulations worldwide.

Common drivers based on this kernel subsystem include most of driver.wlan: ath11k, mt76, rtl819x, mwlwifi, brcmfmac, etc.

iwinfo is a CLI frontend to the custom library, which assembles information from various places. It is also used by LuCI

• When in AP-mode, obtain a list of connected clients in STA-mode:

  iwinfo wlan0/wl0/ath0 assoclist

iw is the configuration utility for the nl80211 API.

• Add a new virtual interface with the given configuration:

  iw dev <devname> interface add <name> type <type> [mesh_id <meshid>] [4addr on|off] [flags <flag>*]

  Valid interface types are: managed, ibss, monitor, mesh, wds. See →wireless modes
  The flags are only used for monitor interfaces, valid flags are: none, fcsfail, control, otherbss, cook

• Add a new virtual interface with the given configuration:

  iw phy <phyname> interface add <name> type <type> [flags <flag>*]

• Getting the currently set regulatory domain:

  iw reg get

• When in AP-mode, obtain a list of connected clients in STA-mode:

  iw dev wlan0 station dump

  The above also lists retry and fail packet counts, which are helpful in determining if wireless congestion (e.g. from many nearby 2.4GHz networks on the same channel in an apartment complex) is the source of throughput issues.

• Setting regulatory domain. Set your country ISO 3166-1 alpha-2 in capital letters:

  iw reg set XX

Note: The ath9k driver (and all other softmac drivers?) sets its own regulatory restrictions based on its EEPROM, i.e. the ART (Atheros Radio Test) partition on flash. Setting the domain from userland can only further restrict the regulatory settings. So if EEPROM says Japan, you can use all 14 channels, if you then set it to US, you can use merely the 12. It does not work the other way around, i.e. if EEPROM says US, you only can use the allowed 12 channels, no matter what you set in userspace! The value 98 represents a synthesized regulatory domain, based on the intersection of the available source of regulatory information (which can include the EEPROM, the userland setting, and a country IE from your AP).

• Question: Is there any way to get/set these raw settings (like, whatever it has in EEPROM)?
• Answer: Your “expectation” of having the freedom to modify the EEPROM is valid as I agree with it too but current (US) legislation does not allow for it. So to support upstream drivers we just cannot allow for those type of changes. You won't get any support if you try to mess with that stuff unless we get a change in legislation that says otherwise. Please refer to:
  • https://wireless.wiki.kernel.org/en/vendors/VendorSupport
  • https://wireless.wiki.kernel.org/en/developers/Regulatory/statement
  • https://wireless.wiki.kernel.org/en/developers/Regulatory
  • Regulations per country

iwconfig (and /proc/net/wireless) is the configuration utility for the now obsolete Wext API scheduled for removal. Use iw or iwinfo.

The mac80211 subsystem moves all aspects of master mode (a.k.a. AP mode) into user space, thus it depends on hostapd (also read Hostapd) to

• handle authenticating clients,
• set encryption keys,
• establishing key rotation policy,
• handle other aspects of the wireless infrastructure.

Due to this, the old method of issuing iwconfig <wireless interface> mode master no longer works. Userspace programs like hostapd now use netlink (the nl80211 driver) to create a master mode interface for your traffic and a monitor mode interface for receiving and transmitting management frames.

Is a hostapd + wpa_supplicant multicall binary.

Are stripped down versions without OpenSSL dependency.

wpad package is a full featured IEEE 802.1x authenticator/supplicant (WPA/EAP/RADIUS), while wpad-mini only supports WPA-PSK (Pre-shared key). wpad obsoletes hostapd and wpa_supplicant as it offers both authentication service for the access point mode and supplicant services for the wireless client mode in one package.

Also see atheros.and.generic.mac80211.wifi

:

• As far as I understand, wpad is a wrapper around hostapd with multicall support and wpa_supplicant built.
• Both wpad and wpad-mini are just wrappers around 'hostapd' with support packages, see https://dev.openwrt.org/browser/trunk/package/hostapd/Makefile
  • wpad-mini is the base system with only WPA(2)-PSK authentication.
  • wpad supports IEEE 802.1x/WPA/EAP/RADIUS (adds the 'WPA supplicant' package with OpenSSL library)
• The hostapd-utils just adds a small hostapd_cli command line tool for messaging with the daemon.

• atheros.and.generic.mac80211.wifi

• Actually, it's the other way around: hostapd is symlink to wpad, cf. /usr/sbin/hostapd → wpad.
• Turning off debugging for wpa_supplicant decreased size of wpad-package from ~365 KiB to ~286 KiB. Turning off debugging for hostapd did nothing. Because it's a different binary, not included in wpad.

• When in AP-mode, obtain a list of connected clients in STA-mode

  wlanconfig ath0 list sta

• When in AP-mode, obtain a list of connected clients in STA-mode:

  wl assoclist
  wl sta_info macaddr