Copyright (c) 2007 Marcus Glocker <mglocker@openbsd.org>
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.Dd $Mdocdate$ .Os .Dt BWI 4 .Sh NAME .Nm bwi .Nd Broadcom IEEE 802.11b/g wireless network device .Sh SYNOPSIS .Cd "bwi* at cardbus?" .Cd "bwi* at pci?" .Sh DESCRIPTION The .Nm driver provides support for Broadcom AirForce based PCI/Cardbus network adapters.
p
These are the modes the
.Nm
driver can operate in:
l -tag -width "IBSS-masterXX" t 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 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
p
.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
The transmit speed is user-selectable or can be adapted automatically by the
driver depending on the received signal strength and on the number of hardware
transmission retries.
.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:
l -tag -width Ds t Cm bssid Ar bssid Set the desired BSSID.
t Fl bssid Unset the desired BSSID.
The interface will automatically select a BSSID in this mode, which is
the default.
t Cm chan Ar n Set the channel (radio frequency) to be used by the driver based on
the given channel ID
.Ar n .
t 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.
t Cm media Ar media The
.Nm
driver supports the following
.Ar media
types:
p l -tag -width autoselect -compact t Cm autoselect Enable autoselection of the media type and options. t Cm DS1 Set 802.11b DS 1Mbps operation. t Cm DS2 Set 802.11b DS 2Mbps operation. t Cm DS5 Set 802.11b DS 5.5Mbps operation. t Cm DS11 Set 802.11b DS 11Mbps operation. t Cm OFDM6 Set 802.11g OFDM 6Mbps operation. t Cm OFDM9 Set 802.11g OFDM 9Mbps operation. t Cm OFDM12 Set 802.11g OFDM 12Mbps operation. t Cm OFDM18 Set 802.11g OFDM 18Mbps operation. t Cm OFDM24 Set 802.11g OFDM 24Mbps operation. t Cm OFDM36 Set 802.11g OFDM 36Mbps operation. t Cm OFDM48 Set 802.11g OFDM 48Mbps operation. t Cm OFDM54 Set 802.11g OFDM 54Mbps operation. .El t Cm mediaopt Ar opts The .Nm driver supports the following media options:
p
l -tag -width monitor -compact t Cm hostap Select Host AP operation.
t Cm ibss Select IBSS operation.
.It Cm monitor
Select monitor mode.
.El
t Fl mediaopt Ar opts Disable the specified media options on the driver and return it to the
default mode of operation (BSS).
t Cm mode Ar mode The
.Nm
driver supports the following modes:
p l -tag -width 11b -compact t Cm 11b Force 802.11b operation. t Cm 11g Force 802.11g operation. .El t 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). t Fl nwid Set the network ID to the empty string to allow the interface to connect to any available access point. t 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
q 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. t Fl nwkey Disable WEP encryption. This is the default mode of operation. .El .Sh FILES The driver needs a firmware file which is loaded when an interface is brought up:
p
l -tag -width Ds -offset indent -compact t Pa /etc/firmware/bwi-airforce .El
.Pp
These firmware files are not free because Marvell refuses
to grant distribution rights.
As a result, even though
.Ox
includes the driver, the firmware files cannot be included and
users have to download these files on their own.
p A prepackaged version of the firmware, designed to be used with .Xr pkg_add 1 , can be found at: d -literal -offset indent http://www.nazgul.ch/bwi/bwi-firmware-1.0.tgz .Ed .Sh HARDWARE The following cards are among those supported by the .Nm driver:
p l -column -compact "Microcom Travelcard" "MALO111" "CardBus" "a/b/g" -offset 6n .Em "Card Chip Bus Standard" Linksys WPC54G Ver 3 BCM4318 PCI b/g ? BCM4306 PCI b/g .El .Sh EXAMPLES The following .Xr hostname.if 5 example configures bwi0 to join whatever network is available on boot, using WEP key .Dq 0x1deadbeef1 , channel 11, obtaining an IP address using DHCP: d -literal -offset indent dhcp NONE NONE NONE nwkey 0x1deadbeef1 chan 11 .Ed
p The following .Xr hostname.if 5 example creates a host-based access point on boot: d -literal -offset indent inet 192.168.1.1 255.255.255.0 NONE media autoselect \e mediaopt hostap nwid my_net chan 11 .Ed
p Configure bwi0 for WEP, using hex key .Dq 0x1deadbeef1 : d -literal -offset indent # ifconfig bwi0 nwkey 0x1deadbeef1 .Ed
p Return bwi0 to its default settings: d -literal -offset indent # ifconfig bwi0 -bssid -chan media autoselect \e nwid "" -nwkey .Ed
p Join an existing BSS network, .Dq my_net : d -literal -offset indent # ifconfig bwi0 192.168.1.1 netmask 0xffffff00 nwid my_net .Ed .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 hostapd 8 , .Xr ifconfig 8 .Sh HISTORY The .Nm driver first appeared in .Ox 4.3 . .Sh AUTHORS .An -nosplit The .Nm driver was written for DragonFlyBSD by Sepherosa Ziehau and ported to OpenBSD by .An Jonathan Gray and .An Marcus Glocker .