220 lines
6.4 KiB
Groff
220 lines
6.4 KiB
Groff
.\"
|
|
.\" Copyright (c) 2003 Tom Rhodes
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd February 22, 2012
|
|
.Dt WLAN 4
|
|
.Os
|
|
.Sh NAME
|
|
.Nm wlan
|
|
.Nd generic 802.11 link-layer support
|
|
.Sh SYNOPSIS
|
|
.Cd "device wlan"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Nm
|
|
module provides generic code to support 802.11 drivers.
|
|
Where a device does not directly support 802.11 functionality
|
|
this layer fills in.
|
|
The
|
|
.Nm
|
|
module is required by all native 802.11 drivers as well as the
|
|
.Xr ndis 4
|
|
support.
|
|
.Pp
|
|
.Nm
|
|
supports multi-mode devices capable of
|
|
operating in both 2.4GHz and 5GHz bands and supports numerous
|
|
802.11 standards: 802.11a, 802.11b, 802.11g, 802.11n, and 802.11s (Draft 3.0).
|
|
The WPA, 802.11i, and 802.1x security protocols are supported
|
|
through a combination of in-kernel code and user-mode applications.
|
|
The WME/WMM multi-media protocols are supported entirely within
|
|
the
|
|
.Nm
|
|
module but require a suitably capable hardware device.
|
|
Likewise the 802.11h specification is supported only by suitably
|
|
capable devices.
|
|
.Pp
|
|
Drivers provide 802.11 functionality through
|
|
.Nm
|
|
interfaces that are created at runtime using interface cloning.
|
|
This is done with the
|
|
.Xr ifconfig 8
|
|
.Cm create
|
|
command or using the
|
|
.Va wlans_IFX
|
|
variable in
|
|
.Xr rc.conf 5 .
|
|
Some drivers support the creation of multiple
|
|
.Nm
|
|
interfaces that share the same underlying device;
|
|
this is the way by which ``multi-bss support'' is provided but it
|
|
can also be used to create WDS links and other interesting applications.
|
|
.Pp
|
|
There are several types of
|
|
.Nm
|
|
interfaces that may be created:
|
|
.Bl -tag -width monitor
|
|
.It Cm sta
|
|
A client station in an infrastructure bss
|
|
(i.e. one that associates to an access point).
|
|
.It Cm hostap
|
|
An access point in an infrastructure bss.
|
|
.It Cm mesh
|
|
A mesh station in an MBSS network.
|
|
.It Cm adhoc
|
|
A station in an IBSS network.
|
|
.It Cm ahdemo
|
|
A station operating in ``adhoc demo mode''.
|
|
This is essentially an IBSS station that does not use management
|
|
frames (e.g. no beacons are transmitted).
|
|
An
|
|
.Cm ahdemo
|
|
interface is especially useful for applications that want to transmit
|
|
and receive raw 802.11 packets.
|
|
.It Cm monitor
|
|
An interface used exclusively for capturing 802.11 frames.
|
|
In particular this specified to have read-only properties
|
|
which enables it to be operated on frequencies where one
|
|
would otherwise not be allowed.
|
|
.It Cm wds
|
|
A station that passes 4-address 802.11 traffic for the purpose
|
|
of tunneling traffic over a wireless link.
|
|
Typically this station would share the same MAC address as a
|
|
.Cm hostap
|
|
interface.
|
|
It may be possible to create
|
|
.Cm wds
|
|
interfaces without a companion
|
|
.Cm hostap
|
|
interface but that is not guaranteed; one may need to create a
|
|
.Cm hostap
|
|
interface that does not send beacon frames before
|
|
.Cm wds
|
|
interfaces may be created.
|
|
.El
|
|
.Pp
|
|
Note that an interface's type cannot be changed once it is created.
|
|
.Pp
|
|
.Nm
|
|
defines several mechanisms by which plugin modules may
|
|
be used to extend its functionality.
|
|
Cryptographic support such as WEP, TKIP, and AES-CCMP are implemented
|
|
as standalone modules (if not statically configured into a system)
|
|
that register with
|
|
.Nm .
|
|
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.
|
|
.Sh DEBUGGING
|
|
If the
|
|
.Dv IEEE80211_DEBUG
|
|
option is included in the kernel configuration,
|
|
debugging controls are available using:
|
|
.Pp
|
|
.Dl "sysctl net.wlan.X.debug=mask"
|
|
.Pp
|
|
where
|
|
.Ar X
|
|
is the number of the
|
|
.Nm
|
|
instance and mask is a bit-or of control bits that determine which
|
|
debugging messages to enable.
|
|
For example,
|
|
.Pp
|
|
.Dl "sysctl net.wlan.0.debug=0x00200000"
|
|
.Pp
|
|
enables debugging messages related to scanning for an access point,
|
|
adhoc neighbor, or an unoccupied channel when operation as an access point.
|
|
The
|
|
.Xr wlandebug 8
|
|
tool provides a more user-friendly mechanism for doing the same thing.
|
|
Note that
|
|
.Pp
|
|
.Dl "sysctl net.wlan.debug=mask"
|
|
.Pp
|
|
defines the initial value of the debugging flags for each cloned
|
|
.Nm
|
|
interface; this is useful to enable debug messages during interface creation.
|
|
.Sh COMPATIBILITY
|
|
The module name of
|
|
.Nm
|
|
was used to be compatible with
|
|
.Nx .
|
|
.Pp
|
|
Mesh stations follow the 802.11s Draft 3.0 specification which is
|
|
not ratified and subject to change.
|
|
Beware that this specification is incompatible with earlier drafts;
|
|
and stations implementing earlier drafts (e.g. Linux)
|
|
may not interoperate.
|
|
.Sh SEE ALSO
|
|
.Xr an 4 ,
|
|
.Xr ath 4 ,
|
|
.Xr bwi 4 ,
|
|
.Xr bwn 4 ,
|
|
.Xr ipw 4 ,
|
|
.Xr iwi 4 ,
|
|
.Xr iwn 4 ,
|
|
.Xr malo 4 ,
|
|
.Xr mwl 4 ,
|
|
.Xr netintro 4 ,
|
|
.Xr ral 4 ,
|
|
.Xr rum 4 ,
|
|
.Xr run 4 ,
|
|
.Xr uath 4 ,
|
|
.Xr upgt 4 ,
|
|
.Xr ural 4 ,
|
|
.Xr urtw 4 ,
|
|
.Xr wi 4 ,
|
|
.Xr wlan_acl 4 ,
|
|
.Xr wlan_ccmp 4 ,
|
|
.Xr wlan_tkip 4 ,
|
|
.Xr wlan_wep 4 ,
|
|
.Xr wlan_xauth 4 ,
|
|
.Xr wpi 4 ,
|
|
.Xr zyd 4
|
|
.Sh STANDARDS
|
|
More information can be found in the IEEE 802.11 Standards.
|
|
.Sh HISTORY
|
|
The
|
|
.Nm
|
|
driver first appeared in
|
|
.Fx 5.0 .
|
|
.Sh AUTHORS
|
|
Atsushi Onoe is the author of original
|
|
.Nx
|
|
software from which this work began.
|
|
.An -nosplit
|
|
.An Sam Leffler
|
|
brought the code into
|
|
.Fx
|
|
and then rewrote it to support multi-mode devices,
|
|
802.11g, 802.11n, WPA/802.11i, WME, multi-bss, and
|
|
add the extensible frameworks
|
|
for cryptographic, authentication, and access control plugins.
|
|
This manual page was written by
|
|
.An Tom Rhodes Aq Mt trhodes@FreeBSD.org .
|