path: root/share/man/man4/atw.4

.\"     $OpenBSD: atw.4,v 1.15 2005/04/13 16:46:53 jmc Exp $
.\"	$NetBSD: atw.4,v 1.8 2004/06/06 04:05:49 wiz Exp $
.\"
.\" Copyright (c) 2003
.\"	David Young <dyoung@NetBSD.org>. All rights reserved.
.\"
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.\" modification, are permitted provided that the following conditions
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.\" THIS SOFTWARE IS PROVIDED BY David Young AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.Dd June 5, 2004
.Dt ATW 4
.Os
.Sh NAME
.Nm atw
.Nd ADMtek ADM8211 IEEE 802.11b wireless network driver
.Sh SYNOPSIS
.Cd "atw* at cardbus?"
.Cd "atw* at pci?"
.Sh DESCRIPTION
The
.Nm
driver supports PCI/CardBus 802.11b wireless adapters based on the
ADMtek ADM8211.
.Pp
The ADM8211 is a bus-mastering 802.11 Media Access Controller (MAC)
which is derived from ADMtek's DEC/Intel 21143 clones (see
.Xr dc 4
for more information).
It supports contention-free traffic (with an 802.11 Point Coordinator).
The ADM8211 integrates an RF3000 baseband processor (BBP) by RF
Microdevices.
.Pp
In a typical application, the ADM8211 is coupled with an RF front-end
by RFMD and a Silicon Laboratories Si4126 RF/IF synthesizer.
.Pp
With the ADM8211, the division of labor between the host and NIC
is different than with firmware-based NICs such as
.Xr an 4 ,
.Xr awi 4 ,
and
.Xr wi 4 .
The ADM8211 is still responsible for real-time 802.11 functions
such as sending ACK/RTS/CTS/ATIM frames, sending beacons, and
answering CF polls from the access point, but the host takes
responsibility for providing 802.11 functions such as scanning,
association, and authentication.
The host is also responsible for programming both the BBP and the
RF/IF synthesizer.
.Pp
These are the modes the
.Nm
driver can operate in:
.Bl -tag -width "IBSS-masterXX"
.It BSS mode
Also known as
.Em infrastructure
mode, this is used when associating with an access point, through
which all traffic passes.
This mode is the default.
.It IBSS mode
Also known as
.Em IEEE ad-hoc
mode or
.Em peer-to-peer
mode.
This is the standardized method of operating without an access point.
Stations associate with a service set.
However, actual connections between stations are peer-to-peer.
.El
.Pp
.Nm
supports hardware WEP (though see
.Sx CAVEATS
below).
Wired Equivalent Privacy (WEP) is the de facto encryption standard
for wireless networks.
It can be typically configured in one of three modes:
no encryption; 40-bit encryption; or 104-bit encryption.
Unfortunately, due to serious weaknesses in WEP protocol
it is strongly recommended that it not be used as the
sole mechanism to secure wireless communication.
WEP is not enabled by default.
.Sh CONFIGURATION
The
.Nm
driver can be configured at runtime with
.Xr ifconfig 8
or on boot with
.Xr hostname.if 5
using the following parameters:
.Bl -tag -width Ds
.It Cm bssid Ar bssid
Set the desired BSSID.
.It Fl bssid
Unset the desired BSSID.
The interface will automatically select a BSSID in this mode, which is
the default.
.It Cm chan Ar n
Set the channel (radio frequency) to be used by the driver based on
the given channel ID
.Ar n .
.It Fl chan
Unset the desired channel to be used by the driver.
The driver will automatically select a channel in this mode, which is
the default.
.It Cm media Ar media
The
.Nm
driver supports the following
.Ar media
types:
.Pp
.Bl -tag -width autoselect -compact
.It Cm autoselect
Enable autoselection of the media type and options.
.It Cm DS1
Set 802.11b DS 1Mbps operation.
.It Cm DS2
Set 802.11b DS 2Mbps operation.
.It Cm DS5
Set 802.11b DS 5.5Mbps operation.
.It Cm DS11
Set 802.11b DS 11Mbps operation.
.El
.It Cm mediaopt Ar opts
The
.Nm
driver supports the following media options:
.Pp
.Bl -tag -width monitor -compact
.It Cm ibss
Select IBSS operation.
.El
.It Fl mediaopt Ar opts
Disable the specified media options on the driver and return it to the
default mode of operation (BSS).
.It Cm nwid Ar id
Set the network ID.
The
.Ar id
can either be any text string up to 32 characters in length,
or a series of hexadecimal digits up to 64 digits.
An empty
.Ar id
string allows the interface to connect to any available access points.
By default the
.Nm
driver uses an empty string.
.It Cm nwkey Ar key
Enable WEP encryption using the specified
.Ar key .
The
.Ar key
can either be a string, a series of hexadecimal digits (preceded by
.Sq 0x ) ,
or a set of keys of the form
.Dq n:k1,k2,k3,k4 ,
where
.Sq n
specifies which of the keys will be used for transmitted packets,
and the four keys,
.Dq k1
through
.Dq k4 ,
are configured as WEP keys.
If a set of keys is specified, a comma
.Pq Sq \&,
within the key must be escaped with a backslash.
Note that if multiple keys are used, their order must be the same within
the network.
.Nm
is capable of using both 40-bit (5 characters or 10 hexadecimal digits)
or 104-bit (13 characters or 26 hexadecimal digits) keys.
.It Fl nwkey
Disable WEP encryption.
This is the default mode of operation.
.It Cm nwkey persist
Enable WEP encryption with the persistent key stored in the network card.
.It Cm nwkey persist : Ns Ar key
Write
.Ar key
to the persistent memory of the network card,
and enable WEP encryption using that key.
.El
.Sh HARDWARE
The
.Nm
driver supports PCI and CardBus cards using revision 0x11 and 0x15
of the ADM8211 (aka ADM8211A).
This includes:
.Pp
.Bl -tag -width Ds -offset indent -compact
.It 3Com OfficeConnect 3CRSHPW796 CardBus
.It Belkin F5D6001 PCI (version 2 only)
.It Blitz NetWave Point CardBus
.It D-Link DWL-650 Rev. \&L1 CardBus
.It D-Link DWL-520 Rev. \&C1 PCI
.It LanReady WP2000 PCI
.It TrendNet TEW-221PC CardBus
.It Xterasys XN2511B PCI
.El
.Pp
The
.Nm
driver does not yet support cards using revision 0x20 (ADM8211B) or
0x30 (ADM8211C).
This includes:
.Pp
.Bl -tag -width Ds -offset indent -compact
.It SMC 2635W CardBus
.El
.Sh EXAMPLES
The following
.Xr hostname.if 5
example configures atw0 to join whatever network is available on boot,
using WEP key
.Dq 0x1deadbeef1 ,
channel 11, obtaining an IP address using DHCP:
.Bd -literal -offset indent
dhcp NONE NONE NONE nwkey 0x1deadbeef1 chan 11
.Ed
.Pp
Configure atw0 for WEP, using hex key
.Dq 0x1deadbeef1 :
.Bd -literal -offset indent
# ifconfig atw0 nwkey 0x1deadbeef1
.Ed
.Pp
Return atw0 to its default settings:
.Bd -literal -offset indent
# ifconfig atw0 -bssid -chan media autoselect \e
	nwid "" -nwkey
.Ed
.Pp
Join an existing BSS network,
.Dq my_net :
.Bd -literal -offset indent
# ifconfig atw0 192.168.1.1 netmask 0xffffff00 nwid my_net
.Ed
.Sh DIAGNOSTICS
.Bl -diag
.It "atw0: failed to tune channel %d"
The driver failed to tune the radio to a new channel.
The radio remains tuned to the old channel.
.It "atw0: atw_si4136_write wrote %08x, SYNCTL still busy"
The driver waited 100ms without seeing an indication that the
ADM8211 had finished writing a register on the Si4126 RF/IF
synthesizer.
.It "atw0: device timeout"
The ADM8211 failed to generate an interrupt to acknowledge a transmit
command.
.El
.Sh SEE ALSO
.Xr arp 4 ,
.Xr cardbus 4 ,
.Xr ifmedia 4 ,
.Xr intro 4 ,
.Xr netintro 4 ,
.Xr pci 4 ,
.Xr hostname.if 5 ,
.Xr ifconfig 8
.Rs
.%T ADMtek
.%O http://www.admtek.com.tw
.Re
.Rs
.%T Silicon Laboratories
.%O http://www.silabs.com
.Re
.Rs
.%T RF Micro Devices
.%O http://www.rfmd.com
.Re
.Sh HISTORY
The
.Nm
device driver first appeared in
.Ox 3.6 .
.Sh AUTHORS
The
.Nm
driver was written by
.An David Young
.Aq dyoung@NetBSD.org .
For features which the ADM8211 has in common with the DECchip 21x4x,
code was liberally borrowed from the
.Nx
tlp driver by
.An Jason Thorpe
.Aq thorpej@NetBSD.org .
.Sh BUGS
The author does not fully understand what processing the duration
fields for the PLCP header and the 802.11 header undergo before
they are applied to a transmitted frame.
If the duration fields in transmitted frames are incorrect,
network performance may suffer.
.Pp
The driver does not provide rate control when the media type is
set to autoselect.
.Pp
The driver lets you change to hostap mode, but it does not work
and it probably never will.
.Pp
The driver will sometimes complain that it cannot re-tune the radio
because the transmit process has not gone idle.
The author is investigating.
.Pp
Many features are still missing, especially WEP decryption and
802.11 power-saving.
.Pp
The ad-hoc mode has not been rigorously tested.
IBSSs with the same SSID may not coalesce, but this should not
matter for most applications.
.Pp
The driver is untested in the ad-hoc demo mode of Lucent WaveLAN
cards.
.Pp
The ADM8211 supports 802.11 power-saving; however,
.Nm
does not support it yet.
For time-bounded service, the ADM8211 will interoperate with an
access point which implements the 802.11 Point Coordination Function;
however, this is also not supported.
.Pp
Combinations of an ADM8211 with either an Intersil or a Marvell RF
front-end are not supported.
.Pp
.Nm
contains incomplete support for the ADM8211's WEP encryption/decryption
engine.
.Nm
does not yet support hardware WEP decryption; however, it will use
the ADM8211's crypto engine to encrypt transmitted frames.
Documentation from ADMtek claims that, in addition to the 4 104-bit
shared WEP keys, the ADM8211 will store WEP key pairs for up to 20
peers.
The documentation provides no details, hence
.Nm
does not support the 20 key-pairs.