man/man4/ath.4

.\"	$OpenBSD: ath.4,v 1.60 2014/02/15 20:28:19 tedu 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.
.\""
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.\" modification, are permitted provided that the following conditions
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.\"    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.
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.\" 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
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.\"
.\" 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: February 15 2014 $
.Dt ATH 4
.Os
.Sh NAME
.Nm ath
.Nd Atheros IEEE 802.11a/b/g wireless network device with GPIO
.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.
.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.
.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
The
.Nm
driver can be configured to use
Wired Equivalent Privacy (WEP) or
Wi-Fi Protected Access (WPA-PSK and WPA2-PSK).
WPA is the current encryption standard for wireless networks.
It is strongly recommended that WEP
not be used as the sole mechanism
to secure wireless communication,
due to serious weaknesses in it.
.Pp
AR5211 and AR5212 support the AES, TKIP, and Michael cryptographic
operations required for WPA in hardware but at this time the driver
does not support them.
.Pp
The
.Nm
driver can be configured at runtime with
.Xr ifconfig 8
or on boot with
.Xr hostname.if 5 .
.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:
.Bl -column "Proxim Skyline 4030" "AR5212" "Mini PCI" "Standard" -offset 6n
.It Em Card Ta Em Chip Ta Em Bus Ta Em Standard
.It "3Com 3CRPAG175" Ta AR5212 Ta CardBus Ta a/b/g
.\"It "Aztech WL830PC" Ta AR5212 Ta CardBus Ta b/g
.It "Cisco AIR-CB21AG" Ta AR5212 Ta CardBus Ta a/b/g
.It "D-Link DWL-A650" Ta AR5210 Ta CardBus Ta a
.It "D-Link DWL-AB650" Ta AR5211 Ta CardBus Ta a/b
.It "D-Link DWL-A520" Ta AR5210 Ta PCI Ta a
.\"It "D-Link DWL-AG520" Ta AR5212 Ta PCI Ta a/b/g
.\"It "D-Link DWL-AG650" Ta AR5212 Ta CardBus Ta a/b/g
.\"It "D-Link DWL-G520" Ta AR5212 Ta PCI Ta b/g
.\"It "D-Link DWL-G650B" Ta AR5212 Ta CardBus Ta b/g
.\"It "Elecom LD-WL54AG" Ta AR5212 Ta CardBus Ta a/b/g
.It "Elecom LD-WL54" Ta AR5211 Ta CardBus Ta a
.\"It "Fujitsu E5454" Ta AR5212 Ta CardBus Ta a/b/g
.\"It "Fujitsu FMV-JW481" Ta AR5212 Ta CardBus Ta a/b/g
.\"It "Fujitsu E5454" Ta AR5212 Ta CardBus Ta a/b/g
.\"It "HP NC4000" Ta AR5212 Ta PCI Ta a/b/g
.It "IBM 11ABG WL LAN" Ta AR5212 Ta Mini PCI Ta a/b/g
.\"It "I/O Data WN-AB" Ta AR5212 Ta CardBus Ta a/b
.\"It "I/O Data WN-AG" Ta AR5212 Ta CardBus Ta a/b/g
.\"It "I/O Data WN-A54" Ta AR5212 Ta CardBus Ta a
.\"It "Linksys WMP55AG" Ta AR5212 Ta PCI Ta a/b/g
.It "Linksys WPC51AB" Ta AR5211 Ta CardBus Ta a/b
.\"It "Linksys WPC55AG" Ta AR5212 Ta CardBus Ta a/b/g
.\"It "NEC PA-WL/54AG" Ta AR5212 Ta CardBus Ta a/b/g
.\"It "Netgear WAG311" Ta AR5212 Ta PCI Ta a/b/g
.It "Netgear WAB501" Ta AR5211 Ta CardBus Ta a/b
.\"It "Netgear WAG511" Ta AR5212 Ta CardBus Ta a/b/g
.\"It "Netgear WG311 rev1" Ta AR5212 Ta PCI Ta b/g
.\"It "Netgear WG511T" Ta AR5212 Ta CardBus Ta b/g
.\"It "Orinoco 8480" Ta AR5212 Ta CardBus Ta a/b/g
.\"It "Orinoco 8470WD" Ta AR5212 Ta CardBus Ta a/b/g
.It "Planet WL-3560" Ta AR5211 Ta CardBus Ta a/b/g
.It "Proxim Skyline 4030" Ta AR5210 Ta CardBus Ta a
.It "Proxim Skyline 4032" Ta AR5210 Ta PCI Ta a
.\"It "Samsung SWL-5200N" Ta AR5212 Ta CardBus Ta a/b/g
.It "Senao NL-5354MP" Ta AR5212 Ta Mini PCI Ta a/b/g
.It "SMC SMC2735W" Ta AR5210 Ta CardBus Ta a
.\"It "Sony PCWA-C700" Ta AR5212 Ta CardBus Ta a/b
.\"It "Sony PCWA-C300S" Ta AR5212 Ta CardBus Ta b/g
.It "Sony PCWA-C500" Ta AR5210 Ta CardBus Ta a
.It "Wistron CM9" Ta AR5212 Ta Mini PCI Ta a/b/g
.El
.Sh EXAMPLES
The following example scans for available networks:
.Pp
.Dl # ifconfig ath0 scan
.Pp
The following
.Xr hostname.if 5
example configures ath0 to join network
.Dq mynwid ,
using WPA key
.Dq mywpakey ,
obtaining an IP address using DHCP:
.Bd -literal -offset indent
nwid mynwid
wpakey mywpakey
dhcp
.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
mediaopt hostap
nwid mynwid
wpakey mywpakey
.Ed
.Sh DIAGNOSTICS
.Bl -diag
.It "ath0: unable to attach hardware; HAL status N"
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 "ath0: failed to allocate descriptors: N"
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 "ath0: 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 "ath0: 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 "ath0: 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 "ath0: 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 "ath0: unable to reset hardware; hal status N"
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 "ath0: unable to initialize the key cache"
The driver was unable to initialize the hardware key cache.
This should not happen.
.It "ath0: unable to start recv logic"
The driver was unable to restart frame reception.
This should not happen.
.It "ath0: 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 "ath0: bogus xmit rate 0xNNNN"
An invalid transmit rate was specified for an outgoing frame.
The frame is discarded.
This should not happen.
.It "ath0: ath_chan_set: unable to reset channel N (X MHz)"
The Hardware Access Layer was unable to reset the hardware
when switching channels during scanning.
This should not happen.
.It "ath0: unable to allocate channel table"
The driver was unable to allocate memory for the table used to hold
the set of available channels.
.It "ath0: 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 "ath0: 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 "ath0: 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 "ath0: cannot map register space"
The driver was unable to map the device registers into the host address space.
This should not happen.
.It "ath0: could not map interrupt"
The driver was unable to allocate an IRQ for the device interrupt.
This should not happen.
.It "ath0: 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 ,
.Xr intro 4 ,
.Xr netintro 4 ,
.Xr pci 4 ,
.Xr hostname.if 5 ,
.Xr gpioctl 8 ,
.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 Mt 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.
.Pp
Host AP mode doesn't support power saving.
Clients attempting to use power saving mode may experience significant
packet loss (disabling power saving on the client will fix this).
.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.