man/man4/athn.4

.\" $OpenBSD: athn.4,v 1.42 2021/10/15 08:10:44 kn Exp $
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.\" Copyright (c) 2009 Damien Bergamini <damien.bergamini@free.fr>.
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.Dd $Mdocdate: October 15 2021 $
.Dt ATHN 4
.Os
.Sh NAME
.Nm athn
.Nd Atheros IEEE 802.11a/b/g/n wireless network device
.Sh SYNOPSIS
.Cd "athn* at cardbus?"
.Cd "athn* at pci?"
.Cd "athn* at uhub? port ?"
.Sh DESCRIPTION
The
.Nm
driver provides support for a wide variety of
Atheros 802.11n devices, ranging from the AR5008 up to the AR9287.
.Pp
The AR5008 (codenamed Owl) is the first generation of
Atheros 802.11n solutions.
It consists of two chips, a MAC/Baseband Processor and a Radio-on-a-Chip.
The MAC/Baseband Processor can be an AR5416 (PCI and CardBus form factors)
or an AR5418 (PCIe Mini Card form factor).
The radio can be an AR2122, AR2133, AR5122 or an AR5133 chip.
The AR2122 chip operates in the 2GHz spectrum and supports up to 2
transmit paths and 2 receiver paths (2T2R).
The AR2133 chip operates in the 2GHz spectrum and supports up to 3
transmit paths and 3 receiver paths (3T3R).
The AR5122 chip operates in the 2GHz and 5GHz spectra and supports
up to 2 transmit paths and 2 receiver paths (2T2R).
The AR5133 chip operates in the 2GHz and 5GHz spectra and supports
up to 3 transmit paths and 3 receiver paths (3T3R).
.Pp
The AR9001 (codenamed Sowl) is a Mini-PCI 802.11n solution.
It consists of two chips, an AR9160 MAC/Baseband Processor and an
AR9103 or AR9106 Radio-on-a-Chip.
The AR9103 chip operates in the 2GHz spectrum and supports up to 3
transmit paths and 3 receiver paths (3T3R).
The AR9106 chip operates in the 2GHz and 5GHz spectra and supports
up to 3 transmit paths and 3 receiver paths (3T3R).
.Pp
The AR9220, AR9223 and AR9280 (codenamed Merlin) are the
first generation of
Atheros single-chip 802.11n solutions.
The AR9220 and AR9223 exist in PCI and Mini-PCI form factors.
The AR9280 exists in PCIe (DT92), PCIe Mini Card (XB92),
half Mini Card (HB92) and USB 2.0 (AR9280+AR7010) form factors.
The AR9220 and AR9280 operate in the 2GHz and 5GHz spectra and
support 2 transmit paths and 2 receiver paths (2T2R).
The AR9223 operates in the 2GHz spectrum and supports 2
transmit paths and 2 receiver paths (2T2R).
.Pp
The AR9281 is a single-chip PCIe 802.11n solution.
It exists in PCIe Mini Card (XB91) and half Mini Card (HB91) form
factors.
It operates in the 2GHz spectrum and supports 1 transmit path and
2 receiver paths (1T2R).
.Pp
The AR9285 (codenamed Kite) is a single-chip PCIe 802.11n solution that
targets the value PC market.
It exists in PCIe half Mini Card (HB95) form factor only.
It operates in the 2GHz spectrum and supports a single stream (1T1R).
It can be combined with the AR3011 chip to form a combo WiFi/Bluetooth
device (WB195).
.Pp
The AR9271 is a single-chip USB 2.0 802.11n solution.
It operates in the 2GHz spectrum and supports a single stream (1T1R).
.Pp
The AR2427 is a single-chip PCIe 802.11b/g solution similar to the other
AR9280 solutions but with 802.11n capabilities removed.
It exists in PCIe Mini Card form factor only.
It operates in the 2GHz spectrum.
.Pp
The AR9227 and AR9287 are single-chip 802.11n solutions that
target mid-tier PCs.
The AR9227 exists in PCI and Mini-PCI form factors.
The AR9287 exists in PCIe half Mini Card (HB97)
and USB 2.0 (AR9287+AR7010) form factors.
They operate in the 2GHz spectrum and support 2 transmit paths and 2
receiver paths (2T2R).
.Pp
The following table summarizes the supported chips and their capabilities.
.Bl -column "AR9001-3NX2 (AR9160+AR9106)" "2GHz/5GHz" "3x3:3" "PCI/CardBus" -offset 6n
.It Em Chipset Ta Em Spectrum Ta Em TxR:S Ta Em Bus
.It "AR5008-2NG (AR5416+AR2122)" Ta 2GHz Ta 2x2:2 Ta PCI/CardBus
.It "AR5008-3NG (AR5416+AR2133)" Ta 2GHz Ta 3x3:2 Ta PCI/CardBus
.It "AR5008-2NX (AR5416+AR5122)" Ta 2GHz/5GHz Ta 2x2:2 Ta PCI/CardBus
.It "AR5008-3NX (AR5416+AR5133)" Ta 2GHz/5GHz Ta 3x3:2 Ta PCI/CardBus
.It "AR5008E-2NG (AR5418+AR2122)" Ta 2GHz Ta 2x2:2 Ta PCIe
.It "AR5008E-3NG (AR5418+AR2133)" Ta 2GHz Ta 3x3:2 Ta PCIe
.It "AR5008E-2NX (AR5418+AR5122)" Ta 2GHz/5GHz Ta 2x2:2 Ta PCIe
.It "AR5008E-3NX (AR5418+AR5133)" Ta 2GHz/5GHz Ta 3x3:2 Ta PCIe
.It "AR9001-2NG (AR9160+AR9103)" Ta 2GHz Ta 2x2:2 Ta PCI
.It "AR9001-3NG (AR9160+AR9103)" Ta 2GHz Ta 3x3:2 Ta PCI
.It "AR9001-3NX2 (AR9160+AR9106)" Ta 2GHz/5GHz Ta 3x3:2 Ta PCI
.It "AR9220" Ta 2GHz/5GHz Ta 2x2:2 Ta PCI
.It "AR9223" Ta 2GHz Ta 2x2:2 Ta PCI
.It "AR9280" Ta 2GHz/5GHz Ta 2x2:2 Ta PCIe
.It "AR9280+AR7010" Ta 2GHz/5GHz Ta 2x2:2 Ta USB 2.0
.It "AR9281" Ta 2GHz Ta 1x2:2 Ta PCIe
.It "AR9285" Ta 2GHz Ta 1x1:1 Ta PCIe
.It "AR9271" Ta 2GHz Ta 1x1:1 Ta USB 2.0
.It "AR2427" Ta 2GHz Ta 1x1:1 Ta PCIe
.It "AR9227" Ta 2GHz Ta 2x2:2 Ta PCI
.It "AR9287" Ta 2GHz Ta 2x2:2 Ta PCIe
.It "AR9287+AR7010" Ta 2GHz Ta 2x2:2 Ta USB 2.0
.El
.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 Host AP
In this mode the driver 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 (WPA1 and WPA2).
WPA2 is the current encryption standard for wireless networks.
It is strongly recommended that neither WEP nor WPA1
are used as the sole mechanism to secure wireless communication,
due to serious weaknesses.
WPA1 is disabled by default and may be enabled using the option
.Qq Cm wpaprotos Ar wpa1,wpa2 .
For standard WPA networks which use pre-shared keys (PSK),
keys are configured using the
.Qq Cm wpakey
option.
WPA-Enterprise networks require use of the wpa_supplicant package.
The
.Nm
driver offloads both encryption and decryption to the hardware for the
CCMP cipher.
.Pp
The transmit speed is user-selectable or can be adapted automatically by the
driver depending on the number of hardware transmission retries.
.Pp
In BSS mode,
the driver supports powersave mode,
which can be enabled via
.Xr ifconfig 8 .
In Host AP mode,
the driver is compatible with clients using powersave, except on AR7010
and AR9287 USB devices.
.Pp
The
.Nm
driver can be configured at runtime with
.Xr ifconfig 8
or on boot with
.Xr hostname.if 5 .
.Sh FILES
For USB devices, the driver needs at least version 1.1p4 of the following
firmware files, which are loaded when an interface is attached:
.Pp
.Bl -tag -width Ds -offset indent -compact
.It Pa /etc/firmware/athn-open-ar7010
.It Pa /etc/firmware/athn-open-ar9271
.El
.Pp
A prepackaged version of the firmware can be installed using
.Xr fw_update 1 .
Firmware source code is available under a mix of BSD and GPLv2 licences.
A port which cross-compiles the firmware can be found in
.Pa /usr/ports/devel/open-ath9k-htc-firmware .
.Sh EXAMPLES
The following example scans for available networks:
.Pp
.Dl # ifconfig athn0 scan
.Pp
The following
.Xr hostname.if 5
example configures athn0 to join network
.Dq mynwid ,
using WPA key
.Dq mywpakey ,
obtaining an IP address using DHCP:
.Bd -literal -offset indent
nwid mynwid wpakey mywpakey
inet autoconf
.Ed
.Pp
The following
.Xr hostname.if 5
example creates a host-based access point on boot:
.Bd -literal -offset indent
mediaopt hostap
nwid mynwid wpakey mywpakey
inet 192.168.1.1 255.255.255.0
.Ed
.Sh DIAGNOSTICS
.Bl -diag
.It "athn0: device timeout"
A frame dispatched to the hardware for transmission did not complete in time.
The driver will reset the hardware.
This should not happen.
.It "athn0: radio is disabled by hardware switch"
The radio transmitter is off and thus no packet can go out.
The driver will reset the hardware.
Make sure the laptop radio switch is on.
.It "athn0: radio switch turned off"
The radio switch has been turned off while the interface was up and running.
The driver will turn the interface down.
.It "athn0: error N, could not read firmware ..."
For some reason, the driver was unable to read the firmware file from the
filesystem.
The file might be missing or corrupted.
.El
.Sh SEE ALSO
.Xr arp 4 ,
.Xr cardbus 4 ,
.Xr ifmedia 4 ,
.Xr intro 4 ,
.Xr netintro 4 ,
.Xr pci 4 ,
.Xr usb 4 ,
.Xr hostname.if 5 ,
.Xr ifconfig 8
.Sh HISTORY
The
.Nm
driver first appeared in
.Ox 4.7 .
Support for USB 2.0 devices first appeared in
.Ox 4.9 .
.Sh AUTHORS
The
.Nm
driver was written by
.An Damien Bergamini Aq Mt damien.bergamini@free.fr
based on source code licensed under the ISC released in 2008 by
Atheros Communications for Linux.
.An Anthony J. Bentley Aq Mt bentley@openbsd.org
added the open source USB firmware and its cross-compiler to the ports tree.
.An Stefan Sperling Aq Mt stsp@openbsd.org
implemented driver support for the open source USB firmware.
.Sh CAVEATS
Support for 802.11n 40MHz channels and Tx aggregation is not yet implemented.
Additional work is required in
.Xr ieee80211 9
before those features can be supported.
.Pp
On USB devices, Host AP mode is limited to 7 concurrent clients and does
not support power saving.
Clients attempting to use power saving mode may experience significant
packet loss.