WLAN(4) MidnightBSD Kernel Interfaces Manual WLAN(4)

NAME

wlan — generic 802.11 link-layer support

SYNOPSIS

device wlan

DESCRIPTION

The wlan module provides generic code to support 802.11 drivers. Where a device does not directly support 802.11 functionality this layer fills in. The wlan is required for the an(4), ath(4), awi(4), ipw(4), iwi(4), ral(4), rum(4), ural(4), wi(4), and zyd(4) drivers, with other drivers to follow.

The wlan module supports multi-mode devices capable of operating in both 2.4GHz and 5GHz bands and supports numerous 802.11 protocols: 802.11a, 802.11b, and 802.11g. The WPA, 802.11i, and 802.1x security protocols are supported through a combination of in-kernel code and user-mode applications. The WME and WMM multi-media protocols are supported entirely within the wlan module but require a suitably capable hardware device.

The wlan module defines several mechanisms by which plugin modules may be used to extend functionality. Cryptographic support such as WEP, TKIP, and AES-CCMP are implemented as modules that are loaded on demand (if not statically configured into a system). Similarly there is an authenticator framework for defining 802.11 authentication services and a framework for integrating access control mechanisms specific to the 802.11 protocol.

DEBUGGING

If the associated interface is marked for debugging with, for example,

ifconfig wi0 debug

then messages describing the operation of the 802.11 protocol will be sent to the console. Complete debugging controls are available using:

sysctl net.wlan.X.debug=mask

where X is the number of the wlan instance and mask is a bit-or of control bits that determine which debugging messages to enable. For example,

sysctl net.wlan.0.debug=0x00200000

enables debugging messages related to scanning for an access point, adhoc neighbor, or an unoccupied channel when operation as an access point. The 80211debug tool provides a more user-friendly mechanism for doing the same thing.

Many drivers will also display the contents of each 802.11 frame sent and received when the interface is marked with both debugging and link2; e.g.,

ifconfig wi0 debug link2

Beware however that some management frames may be processed entirely within the device and not be received by the host.

COMPATIBILITY

The module name of wlan was used to be compatible with NetBSD.

SEE ALSO

an(4), ath(4), awi(4), ipw(4), iwi(4), netintro(4), ral(4), rum(4), ural(4), wi(4), wlan_acl(4), wlan_ccmp(4), wlan_tkip(4), wlan_wep(4), wlan_xauth(4), zyd(4)

STANDARDS

More information can be found in the IEEE 802.11 Standard.

HISTORY

The wlan driver first appeared in FreeBSD 5.0.

AUTHORS

Atsushi Onoe is the author of original NetBSD software from which this work began. Sam Leffler brought the code into FreeBSD and then rewrote it to support multi-mode devices, 802.11g, WPA/802.11i, WME, and add the extensible frameworks for cryptographic, authentication, and access control plugins. This manual page was written by Tom Rhodes 〈trhodes@FreeBSD.org〉.

MidnightBSD 0.3 September 6, 2007 MidnightBSD 0.3