.\"	$OpenBSD: ath.4,v 1.37 2007/05/31 19:19:49 jmc Exp $
.\"     $NetBSD: ath.4,v 1.5 2004/07/03 16:58:18 mycroft Exp $
.\"
.\" Copyright (c) 2002, 2003 Sam Leffler, Errno Consulting
.\" 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,
.\"    without modification.
.\" 2. Redistributions in binary form must reproduce at minimum a disclaimer
.\"    similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
.\"    redistribution must be conditioned upon including a substantially
.\"    similar Disclaimer requirement for further binary redistribution.
.\" 3. Neither the names of the above-listed copyright holders nor the names
.\"    of any contributors may be used to endorse or promote products derived
.\"    from this software without specific prior written permission.
.\"
.\" NO WARRANTY
.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
.\" LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
.\" AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
.\" THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR 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 DAMAGES.
.\"
.\"
.\" Note: This man page was taken by Perry Metzger almost entirely
.\" from the "ath" and "ath_hal" man pages in FreeBSD. I claim no
.\" copyright because there was nearly no original work performed in
.\" doing so. Maintainers should check the FreeBSD originals for
.\" updates against the following two revisions and incorporate them
.\" if needed:
.\"
.\" $FreeBSD: /repoman/r/ncvs/src/share/man/man4/ath.4,v 1.16 2004/02/18 08:30:08 maxim Exp $
.\" parts from $FreeBSD: /repoman/r/ncvs/src/share/man/man4/ath_hal.4,v 1.7 2004/01/07 20:49:51 blackend Exp $
.\"
.Dd $Mdocdate: May 31 2007 $
.Dt ATH 4
.Os
.Sh NAME
.Nm ath
.Nd Atheros IEEE 802.11a/b/g wireless network device
.Sh SYNOPSIS
.Cd "ath* at pci? dev ? function ?"
.Cd "ath* at cardbus? dev ? function ?"
.Cd "gpio* at ath?"
.Sh DESCRIPTION
The
.Nm
driver provides support for wireless network devices based on
the Atheros AR5210, AR5211, and AR5212 chips.
.Pp
All host/device interaction is via DMA.
The
.Nm
driver encapsulates all IP and ARP traffic as 802.11 frames, though
it can receive either 802.11 or 802.3 frames.
Transmit speed and operating mode is selectable and
depends on the specific chipset.
.Pp
Support for the various devices is as follows:
.Bl -tag -width "ARxxxx"
.It AR5210
These devices support 802.11a operation with transmit speeds
of 6 Mbps, 9 Mbps, 12 Mbps, 18 Mbps, 24 Mbps, 36 Mbps, 48 Mbps, and 54 Mbps.
.Pp
.It AR5211
These devices support 802.11a and 802.11b operation with
transmit speeds as above for 802.11a and
1Mbps, 2Mbps, 5.5 Mbps, and 11Mbps for 802.11b operation.
.Pp
.It AR5212
These devices support 802.11a, 802.11b, and 802.11g operation with
transmit speeds as above for 802.11a, 802.11b, and 802.11g operation
(802.11g speeds are the same as for 802.11a speeds).
.El
.Pp
All chips also support an Atheros Turbo Mode (TM) that operates in the
802.11a frequency range with 2x the transmit speeds.
(This mode is, however, only interoperable with other Atheros-based devices.)
.Pp
The actual transmit speed used is dependent on signal quality and the
.Dq rate control
algorithm employed by the driver.
.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.
.It Host AP
In this mode the adapter acts as an access point (base station)
for other cards.
.It monitor mode
In this mode the driver is able to receive packets without
associating with an access point.
This disables the internal receive filter and enables the card to
capture packets from networks which it wouldn't normally have access to,
or to scan for access points.
.El
.Pp
.Nm
supports hardware WEP.
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.
.Pp
AR5211 and AR5212 support the AES, TKIP, and Michael cryptographic
operations required for WPA but at this time the driver does not support them.
.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.
.It Cm OFDM6
Set 802.11a/g OFDM 6Mbps operation.
.It Cm OFDM9
Set 802.11a/g OFDM 9Mbps operation.
.It Cm OFDM12
Set 802.11a/g OFDM 12Mbps operation.
.It Cm OFDM18
Set 802.11a/g OFDM 18Mbps operation.
.It Cm OFDM24
Set 802.11a/g OFDM 24Mbps operation.
.It Cm OFDM36
Set 802.11a/g OFDM 36Mbps operation.
.It Cm OFDM48
Set 802.11a/g OFDM 48Mbps operation.
.It Cm OFDM54
Set 802.11a/g OFDM 54Mbps operation.
.El
.It Cm mediaopt Ar opts
The
.Nm
driver supports the following media options:
.Pp
.Bl -tag -width monitor -compact
.It Cm hostap
Select Host AP operation.
.It Cm ibss
Select IBSS operation.
.It Cm monitor
Select monitor mode.
.It Cm turbo
Select turbo mode.
.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 mode Ar mode
The
.Nm
driver supports the following modes:
.Pp
.Bl -tag -width 11b -compact
.It Cm 11a
Force 802.11a operation.
.It Cm 11b
Force 802.11b operation.
.It Cm 11g
Force 802.11g operation.
.El
.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.
Note that network ID is synonymous with Extended Service Set ID (ESSID).
.It Fl nwid
Set the network ID to the empty string to allow the interface to connect
to any available access point.
.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.
.It Cm powersave
Enable power saving mode.
.It Fl powersave
Disable power saving mode.
This is the default mode of operation.
.It Cm powersavesleep Ar duration
Set the receiver sleep duration (in milliseconds) for power saving mode.
.El
.Sh HARDWARE
Devices supported by the
.Nm
driver come in either CardBus or Mini PCI packages.
Wireless cards in CardBus slots may be inserted and ejected on the fly.
.Pp
The following cards are among those supported by the
.Nm
driver:
.Pp
.Bl -column -compact "Samsung SWL-5200N" "AR5212" "CardBus" "a/b/g" -offset 6n
.Em "Card	Chip	Bus	Standard"
3Com 3CRPAG175	AR5212	CardBus	a/b/g
.\"Aztech WL830PC	AR5212	CardBus	b/g
Cisco AIR-CB21AG	AR5212	CardBus	a/b/g
D-Link DWL-A650	AR5210	CardBus	a
D-Link DWL-AB650	AR5211	CardBus	a/b
D-Link DWL-A520	AR5210	PCI	a
.\"D-Link DWL-AG520	AR5212	PCI	a/b/g
.\"D-Link DWL-AG650	AR5212	CardBus	a/b/g
.\"D-Link DWL-G520	AR5212	PCI	b/g
.\"D-Link DWL-G650B	AR5212	CardBus	b/g
.\"Elecom LD-WL54AG	AR5212	CardBus	a/b/g
Elecom LD-WL54	AR5211	CardBus	a
.\"Fujitsu E5454	AR5212	CardBus	a/b/g
.\"Fujitsu FMV-JW481	AR5212	CardBus	a/b/g
.\"Fujitsu E5454	AR5212	CardBus	a/b/g
.\"HP NC4000	AR5212	PCI	a/b/g
IBM 11ABG WL LAN	AR5212	Mini PCI	a/b/g
.\"I/O Data WN-AB	AR5212	CardBus	a/b
.\"I/O Data WN-AG	AR5212	CardBus	a/b/g
.\"I/O Data WN-A54	AR5212	CardBus	a
.\"Linksys WMP55AG	AR5212	PCI	a/b/g
Linksys WPC51AB	AR5211	CardBus	a/b
.\"Linksys WPC55AG	AR5212	CardBus	a/b/g
.\"NEC PA-WL/54AG	AR5212	CardBus	a/b/g
.\"Netgear WAG311	AR5212	PCI	a/b/g
Netgear WAB501	AR5211	CardBus	a/b
.\"Netgear WAG511	AR5212	CardBus	a/b/g
.\"Netgear WG311 rev1	AR5212	PCI	b/g
.\"Netgear WG511T	AR5212	CardBus	b/g
.\"Orinoco 8480	AR5212	CardBus	a/b/g
.\"Orinoco 8470WD	AR5212	CardBus	a/b/g
Planet WL-3560	AR5211	CardBus	a/b/g
Proxim Skyline 4030	AR5210	CardBus	a
Proxim Skyline 4032	AR5210	PCI	a
.\"Samsung SWL-5200N	AR5212	CardBus	a/b/g
Senao NL-5354MP	AR5212	Mini PCI	a/b/g
SMC SMC2735W	AR5210	CardBus	a
.\"Sony PCWA-C700	AR5212	CardBus	a/b
.\"Sony PCWA-C300S	AR5212	CardBus	b/g
Sony PCWA-C500	AR5210	CardBus	a
Wistron CM9	AR5212	Mini PCI	a/b/g
.El
.Pp
An up to date list can be found at
.Pa http://customerproducts.atheros.com/customerproducts/default.asp .
.Sh EXAMPLES
The following
.Xr hostname.if 5
example configures ath0 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
The following
.Xr hostname.if 5
example creates a host-based access point on boot:
.Bd -literal -offset indent
inet 192.168.1.1 255.255.255.0 NONE media autoselect \e
	mediaopt hostap nwid my_net chan 11
.Ed
.Pp
Configure ath0 for WEP, using hex key
.Dq 0x1deadbeef1 :
.Bd -literal -offset indent
# ifconfig ath0 nwkey 0x1deadbeef1
.Ed
.Pp
Return ath0 to its default settings:
.Bd -literal -offset indent
# ifconfig ath0 -bssid -chan media autoselect \e
	nwid "" -nwkey -powersave
.Ed
.Pp
Join an existing BSS network,
.Dq my_net :
.Bd -literal -offset indent
# ifconfig ath0 192.168.1.1 netmask 0xffffff00 nwid my_net
.Ed
.Sh DIAGNOSTICS
.Bl -diag
.It "ath%d: unable to attach hardware; HAL status %u"
The Hardware Access Layer was unable to configure the hardware
as requested.
The status code is explained in the HAL include file
.Pa sys/dev/ic/ar5xxx.h .
.It "ath%d: failed to allocate descriptors: %d"
The driver was unable to allocate contiguous memory for the transmit
and receive descriptors.
This usually indicates system memory is scarce and/or fragmented.
.It "ath%d: unable to setup a data xmit queue!"
The request to the HAL to set up the transmit queue for normal
data frames failed.
This should not happen.
.It "ath%d: unable to setup a beacon xmit queue!"
The request to the HAL to set up the transmit queue for 802.11 beacon frames
failed.
This should not happen.
.It "ath%d: hardware error; resetting"
An unrecoverable error in the hardware occurred.
Errors of this sort include unrecoverable DMA errors.
The driver will reset the hardware and continue.
.It "ath%d: rx FIFO overrun; resetting"
The receive FIFO in the hardware overflowed before the data could be
transferred to the host.
This typically occurs because the hardware ran short of receive
descriptors and had no place to transfer received data.
The driver will reset the hardware and continue.
.It "ath%d: unable to reset hardware; hal status %u"
The Hardware Access Layer was unable to reset the hardware
as requested.
The status code is explained in the HAL include file
.Pa /sys/dev/ic/ar5xxx.h .
This should not happen.
.It "ath%d: unable to initialize the key cache"
The driver was unable to initialize the hardware key cache.
This should not happen.
.It "ath%d: unable to start recv logic"
The driver was unable to restart frame reception.
This should not happen.
.It "ath%d: device timeout"
A frame dispatched to the hardware for transmission did not complete in time.
The driver will reset the hardware and continue.
This should not happen.
.It "ath%d: bogus xmit rate 0x%x"
An invalid transmit rate was specified for an outgoing frame.
The frame is discarded.
This should not happen.
.It "ath%d: ath_chan_set: unable to reset channel %u (%u Mhz)"
The Hardware Access Layer was unable to reset the hardware
when switching channels during scanning.
This should not happen.
.It "ath%d: unable to allocate channel table"
The driver was unable to allocate memory for the table used to hold
the set of available channels.
.It "ath%d: unable to collect channel list from hal"
A problem occurred while querying the HAL to find the set of available
channels for the device.
This should not happen.
.It "ath%d: failed to enable memory mapping"
The driver was unable to enable memory-mapped I/O to the PCI device registers.
This should not happen.
.It "ath%d: failed to enable bus mastering"
The driver was unable to enable the device as a PCI bus master for doing DMA.
This should not happen.
.It "ath%d: cannot map register space"
The driver was unable to map the device registers into the host address space.
This should not happen.
.It "ath%d: could not map interrupt"
The driver was unable to allocate an IRQ for the device interrupt.
This should not happen.
.It "ath%d: could not establish interrupt"
The driver was unable to install the device interrupt handler.
This should not happen.
.El
.Sh SEE ALSO
.Xr arp 4 ,
.Xr cardbus 4 ,
.Xr gpio 4 ,
.Xr ifmedia 4 ,
.Xt intro 4 ,
.Xr netintro 4 ,
.Xr pci 4 ,
.Xr hostname.if 5 ,
.Xr hostapd 8 ,
.Xr ifconfig 8
.Sh HISTORY
The
.Nm
device driver first appeared in
.Fx 5.2
using a binary-only HAL module which was ported to
.Nx 2.0 .
The driver using a free HAL-replacement first appeared in
.Ox 3.7 .
.Sh AUTHORS
.An -nosplit
The
.Nm
driver was written by
.An Sam Leffler ,
and was ported to
.Ox
by
.An Reyk Floeter Aq reyk@openbsd.org
who also wrote a free replacement of the binary-only HAL.
.Sh CAVEATS
Different regulatory domains may not be able to communicate with each
other with 802.11a as different regulatory domains do not necessarily
have overlapping channels.
.Sh BUGS
Performance in lossy environments is suboptimal.
The algorithm used to select the rate for transmitted packets is
very simplistic.
There is no software retransmit; only hardware retransmit is used.
Contributors are encouraged to replace the existing rate control algorithm
with a better one.
.Pp
The driver does not fully enable power-save operation of the chip;
consequently power use is suboptimal.