Wireless Driver README: Difference between revisions

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{{OLPC}}

== OVERVIEW ==

This page describes all the mechanisms available to configure the behaviour of the wireless subsystem. Through the times, some of these configuration features were removed from the driver, or implemented in another way. An old version of this page is kept [http://wiki.laptop.org/go/Wireless_Driver_OLDREADME here], as a reference (if you notice that a certain iwpriv command is not available any more, and it is listed in this old version, this means that the command was removed from the driver).

== DRIVER LOADING ==
== DRIVER LOADING ==
<pre>
<pre>
Line 15: Line 21:
Linux Driver. All the commands available in Wlanconfig will not be available
Linux Driver. All the commands available in Wlanconfig will not be available
in the iwpriv.
in the iwpriv.



SYNOPSIS
SYNOPSIS
iwpriv <ethX> <command> [sub-command] ...
iwpriv <ethX> <command> [sub-command] ...


Region Commands:
iwpriv ethX version
iwpriv ethX scantype [sub-command]
iwpriv ethX getSNR <n>
iwpriv ethX getNF <n>
iwpriv ethX getRSSI <n>
iwpriv ethX setrxant <n>
iwpriv ethX getrxant
iwpriv ethX settxant <n>
iwpriv ethX gettxant
iwpriv ethX authalgs <n>
iwpriv ethX pre-TBTT <n>
iwpriv ethX 8021xauthalgs <n>
iwpriv ethX encryptionmode <n>
iwpriv ethX setregioncode <n>
iwpriv ethX setregioncode <n>
iwpriv ethX getregioncode
iwpriv ethX getregioncode
iwpriv ethX setbcnavg <n>
iwpriv ethX getbcnavg
iwpriv ethX setdataavg <n>
iwpriv ethX setlisteninter <n>
iwpriv ethX getlisteninter
iwpriv ethX setmultipledtim <n>
iwpriv ethX getmultipledtim
iwpriv ethX atimwindow <n>
iwpriv ethX deauth
iwpriv ethX adhocstop
iwpriv ethX radioon
iwpriv ethX radiooff
iwpriv ethX reasso-on
iwpriv ethX reasso-off
iwpriv ethX scanmode [sub-command]
iwpriv ethX setwpaie <n>
iwpriv ethX wlanidle-off
iwpriv ethX wlanidle-on
iwpriv ethX getcis
iwpriv ethX getlog
iwpriv ethX getadhocstatus
iwpriv ethX adhocgrate <n>


LED Behaviour Commands:
Version 4 Command:
iwpriv ethX inactvityto <n>
iwpriv ethX sleeppd <n>
iwpriv ethX enable11d <n>
iwpriv ethX tpccfg <n>
iwpriv ethX powercfg <n>
iwpriv ethX setafc <n>
iwpriv ethX getafc

Version 5 Command:
iwpriv ethX ledgpio <n>
iwpriv ethX ledgpio <n>
iwpriv ethX scanprobes <n>
iwpriv ethX ledbhv <n>

iwpriv ethX lolisteninter <n>
WOL (Wake-on-Lan) Filter Commands:
iwpriv ethX rateadapt <n> <m>
[TODO: updating this information]
iwpriv ethX txcontrol <n>
iwpriv get_wol_rule, iwpriv set_wol_rule, iwpriv reset_wol_rule
iwpriv ethX psnullinterval <n>
iwpriv ethX prescan <n>
iwpriv ethX getrxinfo
iwpriv ethX gettxrate
iwpriv ethX beaconinterval


BT Commands:
Management Frames Control Commands:
iwpriv bcn_control <n> <m>
iwpriv setprspretrylt <n>

BT (Blinding Table) Commands:
The blinding table (BT) contains a list of mac addresses that will be,
The blinding table (BT) contains a list of mac addresses that will be,
by default, ignored by the firmware. It is also possible to invert this
by default, ignored by the firmware. It is also possible to invert this
Line 93: Line 57:
iwpriv ethX bt_set_invert <n>
iwpriv ethX bt_set_invert <n>


FWT Commands:
FWT (Forwarding Table) Commands:
The forwarding table (FWT) is a feature used to manage mesh network
The forwarding table (FWT) is a feature used to manage mesh network
routing in the firmware. The FWT is essentially a routing table that
routing in the firmware. The FWT is essentially a routing table that
Line 119: Line 83:


MESH Commands:
MESH Commands:

The MESH commands are used to configure various features of the mesh
The MESH commands are used to configure various features of the mesh
routing protocol. The following commands are supported:
routing protocol. The following commands are supported:
Line 140: Line 103:
The ethX parameter specifies the network device that is to be used to
The ethX parameter specifies the network device that is to be used to
perform this command on. it could be eth0, eth1 etc.
perform this command on. it could be eth0, eth1 etc.

version
This is used to get the current version of the driver and the firmware.

scantype
This command is used to set the scan type to be used by the driver in
the scan command. This setting will not be used while performing a scan
for a specific SSID, as it is always done with scan type being active.
where the sub-commands are: -
active -- to set the scan type to active
passive -- to set the scan type to passive
get -- to get the scan type set in the driver

getSNR
This command gets the average and non average value of Signal to Noise
Ratio of Beacon and Data.
where value is:-
0 -- Beacon non-average.
1 -- Beacon average.
2 -- Data non-average.
3 -- Data average.

If no value is given, all four values are returned in the order mentioned
above.

Note: This command is available only when STA is connected.

getRSSI
This command gets the average and non average value os Receive Signal
Strength of Beacon and Data.
where value is:-
0 -- Beacon non-average.
1 -- Beacon average.
2 -- Data non-average.
3 -- Data average.

Note: This command is available only when STA is connected.

getNF
This command gets the average and non average value of Noise Floor of
Beacon and Data.
where value is:-
0 -- Beacon non-average.
1 -- Beacon average.
2 -- Data non-average.
3 -- Data average.

Note: This command is available only when STA is connected.

setrxant
This command is used to set the mode for Rx antenna.
The options that can be sent are:-
1 -- Antenna 1.
2 -- Antenna 2.
0xFFFF -- Diversity.

Usage:
iwpriv ethX setrxant 0x01: select Antenna 1.

getrxant
This command is used to get the mode for Rx antenna.


settxant
This command is used to set the mode for Tx antenna.
The options that can be sent are:-
1 -- Antenna 1.
2 -- Antenna 2.
0xFFFF -- Diversity.
Usage:
iwpriv ethX settxant 0x01: select Antenna 1.

gettxant
This command is used to get the mode for Tx antenna.

authalgs
This command is used by the WPA supplicant to set the authentication
algorithms in the station.

8021xauthalgs
This command is used by the WPA supplicant to set the 8021.x authentication algorithm type
station.
where values can be:-
1 -- None
2 -- LEAP
4 -- TLS
8 -- TTLs
16 -- MD5


encryptionmode
This command is used by the WPA supplicant to set the encryption algorithm.
where values can be:-
0 -- NONE
1 -- WEP40
2 -- TKIP
3 -- CCMP
4 -- WEP104

pre-TBTT
This command is used to set pre-TBTT time period where value is in microseconds.


setregioncode
setregioncode
Line 260: Line 115:
This command is used to get the region code information set in the
This command is used to get the region code information set in the
station.
station.

setbcnavg
Set the weighting factor for calculating RSSI.

getbcnavg
Get weighting factor for calculating RSSI.

setdataavg
Set the weighting factor for calculating SNR.

setlisteninter
This command is used to set the listen interval in the
station.
where the value ranges between 1 - 255

getlisteninter
This command is used to get the listen interval value set in the
station.

setmultipledtim
This command is used to set the multiple dtim value in the
station.
where the value is 1,2,3,4,5,0xfffe
0xfffe means the firmware will use listen interval in association
command for waking up

getmultipledtim
This command is used to get the multiple dtim value set in the station.

atimwindow
This command is used to set the atim value in the
station.

where the value ranges between 0 - 50

deauth
This command is used to send the de-authentication to the AP with which
the station is associated. This command is valid only when
station is in Infrastructure mode.

Note: This command is available only when STA is connected.

adhocstop
This command is used to stop beacon transmission from the station and
go into idle state in ad-hoc mode.
Note: This command is available only when STA is connected.

radioon
This command is used to turn on the RF antenna.

radiooff
This command is sued to turn off the RF antenna.

scanmode
This command is used to set the station to scan for either IBSS
networks or BSS networks or both BSS and IBSS networks. This
command can be used with sub commands,

where the value for
bss -- Scan All the BSS networks.
ibss -- Scan All the IBSS networks.
any -- Scan both BSS and IBSS networks.


setwpaie
This command is used by WPA supplicant to send the WPA-IE to the driver.
wlanidle-off
This command is used to get into idle state.

Note: This command is available only when STA is connected.

wlanidle-on
This command is used to get off the idle state.

Note: This command is available only when STA is connected.


getlog
This command is used to get the 802.11 statistics available in the
station.
Note: This command is available only when STA is connected.

getadhocstatus
This command is used to get the ad-hoc Network Status.

The various status codes are:
AdhocStarted
AdhocJoined
AdhocIdle
InfraMode
AutoUnknownMode

Note: This command is available only when STA is connected.

adhocgrate
This command is used to enable(1) g_rate, Disable(0) g_rate
and request(2) the status which g_rate is disabled/enabled,
for Ad-hoc creator.

where value is:-
0 -- Disabled
1 -- Enabled
2 -- Get


ledgpio
ledgpio
Line 389: Line 136:


Note: LED0 is invalid
Note: LED0 is invalid
Note: Maximum Number of LEDs are 16.
Note: Maximum Number of LEDs are 16.
inactivityto
This command is used by the host to set/get the inactivity timeout value,
which specifies when WLAN device is put to sleep.
Usage:
iwpriv ethX inactivityto [<timeout>]

where the parameter are:
timeout: timeout value in milliseconds.

Example:
iwpriv eth1 inactivityto
"get the timeout value"

iwpriv eth1 inactivityto X
"set timeout value to X ms"


sleeppd
This command is used to configure the sleep period of the WLAN device.

Usage:
iwpriv ethX sleeppd [<sleep period>]

where the parameter are:
Period: sleep period in milliseconds. Range 10~60.

Example:
iwpriv eth1 sleeppd 10
"set period as 10 ms"
iwpriv eth1 sleeppd
"get the sleep period configuration"

enable11d
This command is used to control 11d
where value is:-
1 -- Enabled
0 -- Disabled
2 -- Get



ledbhv
This command can be used to change default LEDs behaviors.
A given LED behavior can be on, off or blinking. The duty/cycle can be set
when behavior is programmed as blinking.
Usage:
1. To get default LED behavior
iwpriv mshX ledbhv <firmware state>


2. To set or change default LED behavior
tpccfg
iwpriv mshX ledbhv <firmware state> <lednum> <behavior> <arg>
Enables or disables automatic transmit power control.
firmware state: The following are some of the relevant states.

00: disconnected
The first parameter turns this feature on (1) or off (0). When turning
01: firmware is scanning
on, the user must also supply four more parameters in the following
02: firmware is connected and awake
order:
03: firmware is sleeping
-UseSNR (Use SNR (in addition to PER) for TPC algorithm),
04: connected deep sleep
-P0 (P0 power level for TPC),
06: firmware disconnected link lost
-P1 (P1 power level for TPC),
07: firmware disconnected disassociated
-P2 (P2 power level for TPC).
09: data transfer while firmware is associated and not scanning.
(If firmware is already in this state, LED behavior does not change
on this data transfer).
10: firmware idle, not scanning, not disconnected or disassociated.
lednum: 1 or 2 for first and second LED.
behavior: 0 for steady ON, 1 - steady off and 2- blinking.
arg: It is used when behavior is 2 to set duty and cycle. It is defined as
(duty << 4 | cycle). Here duty could be 0..4 and cycle 0..5 for 34,
74, 149, 298, 596, 1192 ms respectively.
Examples:
1. To get default behavior for scan
iwpriv mshX ledbhv 1
2. To get default behavior while data transfer
iwpriv mshX ledbhv 9
3. To turn off LED 2 + iwpriv mshX ledbhv 2 2 1 0
iwpriv mshX ledbhv 10 2 1 0
4. To enable LED 2 and blink LED 1 while data transfer.
iwpriv mshX ledbhv 9 2 0 0
iwpriv mshX ledbhv 9 1 2 4
5. To change duty cycle of LED 2 during data transfer
iwpriv mshX ledbhv 9 2 2 36
6. To turn ON LED 2 when firmware is disassociated/disconnected.
iwpriv mshX ledbhv 0 2 0 0


bcn_control
Sets the beacon interval
Usage:
Usage:
iwpriv ethX tpccfg: Get current configuration
iwpriv ethX bcn_control 1|0 interval
iwpriv ethX tpccfg 0: disable auto TPC
1|0 = enable|disable beacons
interval is the time between beacons in milliseconds
iwpriv ethX tpccfg 0x01 0x00 0x05 0x0a 0x0d: enable auto TPC; do not use SNR;
P0=0x05; P1=0x0a; P2=0x0d;
iwpriv ethX tpccfg 0x01 0x01 0x05 0x0a 0x0d: enable auto TPC; use SNR;
P0=0x05; P1=0x0a; P2=0x0d.


setprspretrylt
powercfg
Sets the number of retries for probe responses
Enables or disables power adaptation.

The first parameter turns this feature on (1) or off (0). When turning
on, the user must also supply three more parameters in the following
order:
-P0 (P0 power level for Power Adaptation),
-P1 (P1 power level for Power Adaptation),
-P2 (P2 power level for Power Adaptation).


Usage:
Usage:
iwpriv ethX powercfg: Get current configuration
iwpriv ethX setprspretrylt <n>
n = number of retries (from 0 to 15)
iwpriv ethX powercfg 0: disable power adaptation
iwpriv ethX powercfg 1 0x0d 0x0f 0x12: enable power adaptation;
P0=0x0d; P1=0x0f; P2=0x12.


getafc
This command returns automatic frequency control parameters. It returns
three integers:
-P0: automatic is on (1), or off (0),
-P1: current timing offset in PPM (part per million), and
-P2: current frequency offset in PPM.

setafc
Set automatic frequency control options.

The first parameter turns automatic on (1) or off (0).
The user must supply two more parameters in either case, in the following
order:

When auto is on:

-P0 (automatic adjustment frequency threshold in PPM),
-P1 (automatic adjustment period in beacon period),

When auto is off:

-P0 (manual adjustment timing offset in PPM), and
-P1 (manual adjustment frequency offset in PPM).

Usage:
iwpriv ethX setafc 0 10 10: manual adjustment, both timing and frequcncy
offset are 10 PPM.

iwpriv ethX setafc 1 10 10 enable afc, automatic adjustment,
frequency threshold 10 PPM, for every 10 beacon periods.



scanprobes
This command sets number of probe requests per channel.

Usage:
iwpriv ethX scanprobes 3 (set scan probes to 3)
iwpriv ethX scanprobes (get scan probes)

lolisteninter
This command sets the value of listen interval.

Usage:
iwpriv ethX lolisteninter 234 (set the lolisteninter to 234)
iwpriv ethX lolisteninter (get the lolisteninter value)

rateadapt
This command sets the data rates bitmap.
Where <n>
0: Disable auto rate adapt
1: Enable auto rate adapt
<m>
data rate bitmap
Bit Data rate
0 1 Mbps
1 2 Mbps
2 5.5 Mbps
3 11 Mbps
4 Reserved
5 6 Mbps
6 9 Mbps
7 12 Mbps
8 18 Mbps
9 24 Mbps
10 36 Mbps
11 48 Mbps
12 54 Mbps
12-15 Reserved

Usage:
iwpriv ethX rateadapt
read the currect data rate setting
iwpriv ethX rateadapt 1 0x07
enable auto data rate adapt and
data rates are 1Mbps, 2Mbsp and 5.5Mbps

txcontrol
This command is used to set the Tx rate, ack policy, and retry limit on a per packet basis.

Where value <n> is:
if bit[4] == 1:
bit[3:0] -- 0 1 2 3 4 5 6 7 8 9 10 11 12 13-16
Data Rate(Mbps) -- 1 2 5.5 11 Rsv 6 9 12 18 24 36 48 54 Rsv

bit[12:8]
if bit[12] == 1, bit[11:8] specifies the Tx retry limit.

bit[14:13] specifies per packet ack policy:
bit[14:13]
1 0 use immediate ack policy for this packet
1 1 use no ack policy for this packet
0 x use the per-packet ack policy setting
Usage:
iwpriv ethX txcontrol 0x7513
Use no-ack policy, 5 retires for Tx, 11Mbps rate



psnullinterval
This command is used to set/request NULL package interval for Power Save
under infrastructure mode.

where value is:-
-1 -- Disabled
n>0 -- Set interval as n (seconds)

prescan
This command is used to enable (1)/disable(0) auto prescan before assoicate to the ap

where value is:-
0 -- Disabled
1 -- Enabled
2 -- Get

getrxinfo
This command gets non average value of Signal to Noise Ratio of Data and rate index.

The following table shows RateIndex and Rate

RateIndex Data rate
0 1 Mbps
1 2 Mbps
2 5.5 Mbps
3 11 Mbps
4 Reserved
5 6 Mbps
6 9 Mbps
7 12 Mbps
8 18 Mbps
9 24 Mbps
10 36 Mbps
11 48 Mbps
12 54 Mbps
13-15 Reserved

gettxrate
This command gets current Tx rate index of the first packet associated with Rate Adaptation.

The following table shows RateIndex and Rate

RateIndex Data rate
0 1 Mbps
1 2 Mbps
2 5.5 Mbps
3 11 Mbps
4 Reserved
5 6 Mbps
6 9 Mbps
7 12 Mbps
8 18 Mbps
9 24 Mbps
10 36 Mbps
11 48 Mbps
12 54 Mbps
13-15 Reserved

bcninterval
This command is used to sets beacon interval in adhoc mode when an argument is given, and gets current adhoc
beacon interval when no argument is given. The valid beacon interval is between 20 - 1000,
default beacon interval is 100.

Usage:
iwpriv ethX bcninterval 100 (set adhoc beacon interval to 100)
iwpriv ethX bcninterval (get adhoc beacon interval)


fwt_add
fwt_add
Line 674: Line 234:
default is 0)
default is 0)


The command does not return anything.
The command does not return anything.


fwt_del
fwt_del
This command is used to remove an entry to the FWT table. The list of
This command is used to remove an entry to the FWT table. The list of
parameters must follow the following structure:
parameters must follow the following structure:


iwpriv ethX fwt_del da ra [dir]
iwpriv ethX fwt_del da ra [dir]


where the different parameters are:-
where the different parameters are:-
da -- DA MAC address (in the form "00:11:22:33:44:55")
da -- DA MAC address (in the form "00:11:22:33:44:55")
ra -- RA MAC address (in the form "00:11:22:33:44:55")
ra -- RA MAC address (in the form "00:11:22:33:44:55")
dir -- direction (1 for direct, 0 for reverse,
dir -- direction (1 for direct, 0 for reverse,
default is 1)
default is 1)


The command does not return anything.
The command does not return anything.


fwt_lookup
fwt_lookup
This command is used to get the best route in the FWT table to a given
This command is used to get the best route in the FWT table to a given
host. The only parameter is the MAC address of the host that is being
host. The only parameter is the MAC address of the host that is being
looked for.
looked for.


iwpriv ethX fwt_lookup da
iwpriv ethX fwt_lookup da


where:-
where:-
da -- DA MAC address (in the form "00:11:22:33:44:55")
da -- DA MAC address (in the form "00:11:22:33:44:55")


The command returns an output string identical to the one returned by
The command returns an output string identical to the one returned by
fwt_list described below.
fwt_list described below.




fwt_list
fwt_list
This command is used to list a route from the FWT table. The only
This command is used to list a route from the FWT table. The only
parameter is the index into the table. If you want to list all the
parameter is the index into the table. If you want to list all the
routes in a table, start with index=0, and keep listing until you get a
routes in a table, start with index=0, and keep listing until you get a
"(null)" string. Note that the indicies may change as the fwt is
"(null)" string. Note that the indicies may change as the fwt is
updated. It is expected that most users will not use fwt_list directly,
updated. It is expected that most users will not use fwt_list directly,
but that a utility similar to the traditional route command will be used
but that a utility similar to the traditional route command will be used
to invoke fwt_list over and over.
to invoke fwt_list over and over.


iwpriv ethX fwt_list index
iwpriv ethX fwt_list index


The output is a string of the following form:
The output is a string of the following form:


da ra valid metric dir rate ssn dsn hopcount ttl expiration
da ra valid metric dir rate ssn dsn hopcount ttl expiration
sleepmode snr precursor
sleepmode snr precursor


where the different fields are:-
where the different fields are:-
da -- DA MAC address (in the form "00:11:22:33:44:55")
da -- DA MAC address (in the form "00:11:22:33:44:55")
ra -- RA MAC address (in the form "00:11:22:33:44:55")
ra -- RA MAC address (in the form "00:11:22:33:44:55")
valid -- whether the route is valid (0 if not valid)
valid -- whether the route is valid (0 if not valid)
metric -- route metric (cost: smaller-metric routes are preferred)
metric -- route metric (cost: smaller-metric routes are preferred)
dir -- direction (1 for direct, 0 for reverse)
dir -- direction (1 for direct, 0 for reverse)
rate -- data rate used for transmission to the RA,
rate -- data rate used for transmission to the RA,
as specified for the rateadapt command
as specified for the rateadapt command
ssn -- Source Sequence Number (time at the RA for reverse routes)
ssn -- Source Sequence Number (time at the RA for reverse routes)
dsn -- Destination Sequence Number (time at the DA for direct routes)
dsn -- Destination Sequence Number (time at the DA for direct routes)
hopcount -- hop count (currently unused)
hopcount -- hop count (currently unused)
ttl -- TTL (only used in reverse entries)
ttl -- TTL (only used in reverse entries)
expiration -- entry expiration (in ticks, where a tick is 1024us, or ~ 1ms. Use 0 for an indefinite entry)
expiration -- entry expiration (in ticks, where a tick is 1024us, or ~ 1ms. Use 0 for an indefinite entry)
sleepmode -- RA's sleep mode (currently unused)
sleepmode -- RA's sleep mode (currently unused)
snr -- SNR in the link to RA (currently unused)
snr -- SNR in the link to RA (currently unused)
precursor -- predecessor in direct routes
precursor -- predecessor in direct routes


fwt_list_route
fwt_list_route
This command is equivalent to fwt_list.
This command is equivalent to fwt_list.


fwt_list_neigh
fwt_list_neigh
This command is used to list a neighbor from the FWT table. The only
This command is used to list a neighbor from the FWT table. The only
parameter is the neighbor ID. If you want to list all the neighbors in a
parameter is the neighbor ID. If you want to list all the neighbors in a
table, start with nid=0, and keep incrementing nid until you get a
table, start with nid=0, and keep incrementing nid until you get a
"(null)" string. Note that the nid from a fwt_list_route command can be
"(null)" string. Note that the nid from a fwt_list_route command can be
used as an input to this command. Also note that this command is meant
used as an input to this command. Also note that this command is meant
mostly for debugging. It is expected that users will use fwt_lookup.
mostly for debugging. It is expected that users will use fwt_lookup.
One important reason for this is that the neighbor id may change as the
One important reason for this is that the neighbor id may change as the
neighbor table is altered.
neighbor table is altered.


iwpriv ethX fwt_list_neigh nid
iwpriv ethX fwt_list_neigh nid


The output is a string of the following form:
The output is a string of the following form:


ra sleepmode snr references
ra sleepmode snr references


where the different fields are:-
where the different fields are:-
ra -- RA MAC address (in the form "00:11:22:33:44:55")
ra -- RA MAC address (in the form "00:11:22:33:44:55")
sleepmode -- RA's sleep mode (currently unused)
sleepmode -- RA's sleep mode (currently unused)
snr -- SNR in the link to RA (currently unused)
snr -- SNR in the link to RA (currently unused)
references -- RA's reference counter
references -- RA's reference counter


fwt_reset
fwt_reset
This command is used to reset the FWT table, getting rid of all the
This command is used to reset the FWT table, getting rid of all the
entries. There are no input parameters.
entries. There are no input parameters.


iwpriv ethX fwt_reset
iwpriv ethX fwt_reset


The command does not return anything.
The command does not return anything.


fwt_cleanup
fwt_cleanup
This command is used to perform user-based garbage recollection. The
This command is used to perform user-based garbage recollection. The
FWT table is checked, and all the entries that are expired or invalid
FWT table is checked, and all the entries that are expired or invalid
are cleaned. Note that this is exported to the driver for debugging
are cleaned. Note that this is exported to the driver for debugging
purposes, as garbage collection is also fired by the firmware when in
purposes, as garbage collection is also fired by the firmware when in
space problems. There are no input parameters.
space problems. There are no input parameters.


iwpriv ethX fwt_cleanup
iwpriv ethX fwt_cleanup


The command does returns the number of invalid/expired routes deleted.
The command does returns the number of invalid/expired routes deleted.


fwt_time
fwt_time
This command returns a card's internal time representation. It is this
This command returns a card's internal time representation. It is this
time that is used to represent the expiration times of FWT entries. The
time that is used to represent the expiration times of FWT entries. The
number is not consistent from card to card; it is simply a timer count.
number is not consistent from card to card; it is simply a timer count.
The fwt_time command is used to inspect the timer so that expiration
The fwt_time command is used to inspect the timer so that expiration
times reported by fwt_list can be properly interpreted.
times reported by fwt_list can be properly interpreted.


iwpriv ethX fwt_time
iwpriv ethX fwt_time


mesh_get_ttl
mesh_get_ttl


The mesh ttl is the number of hops a mesh packet can traverse before it
The mesh ttl is the number of hops a mesh packet can traverse before it
is dropped. This parameter is used to prevent infinite loops in the
is dropped. This parameter is used to prevent infinite loops in the
mesh network. The value returned by this function is the ttl assigned
mesh network. The value returned by this function is the ttl assigned
to all mesh packets. Currently there is no way to control the ttl on a
to all mesh packets. Currently there is no way to control the ttl on a
per packet or per socket basis.
per packet or per socket basis.


iwpriv ethX mesh_get_ttl
iwpriv ethX mesh_get_ttl


mesh_set_ttl ttl
mesh_set_ttl ttl


Set the ttl. The argument must be between 0 and 255.
Set the ttl. The argument must be between 0 and 255.


iwpriv ethX mesh_set_ttl <ttl>
iwpriv ethX mesh_set_ttl <ttl>


mesh_get_bcastr
mesh_get_bcastr
Shows the rate index used for mesh broadcast and multicast packets. The
Shows the rate index used for mesh broadcast and multicast packets. The
mapping to actual rates is the same as for rateadapt command.
mapping to actual rates is the same as for rateadapt command.


iwpriv ethX mesh_get_bcastr rate
iwpriv ethX mesh_get_bcastr rate


mesh_set_bcastr rate
mesh_set_bcastr rate


Sets the rate index for mesh broadcast and muticast packets. The mapping
Sets the rate index for mesh broadcast and muticast packets. The mapping
to actual rates is the same as for rateadapt command.
to actual rates is the same as for rateadapt command.


iwpriv ethX mesh_set_bcastr rate
iwpriv ethX mesh_set_bcastr rate


get_rreq_delay
get_rreq_delay
Shows the delay to forward a RREQ frame. This delay allows the node to
Shows the delay to forward a RREQ frame. This delay allows the node to
forward just the best route in case the same RREQ arrives to the node
forward just the best route in case the same RREQ arrives to the node
through different routes. The argument is shown in 1/100 seconds.
through different routes. The argument is shown in 1/100 seconds.


iwpriv ethX get_rreq_delay
iwpriv ethX get_rreq_delay


set_rreq_delay delay
set_rreq_delay delay


Sets the RREQ forward delay. The delay is interpreted as 1/100 seconds.
Sets the RREQ forward delay. The delay is interpreted as 1/100 seconds.


iwpriv ethX set_rreq_delay delay
iwpriv ethX set_rreq_delay delay


get_route_exp
get_route_exp


Shows the mesh route expiration time, in seconds.
Shows the mesh route expiration time, in seconds.


iwpriv ethX get_route_exp
iwpriv ethX get_route_exp


set_route_exp time
set_route_exp time


Gets the mesh route, expiration time, in seconds.
Gets the mesh route, expiration time, in seconds.


iwpriv ethX set_route_exp time
iwpriv ethX set_route_exp time


get_link_costs
get_link_costs


Gets the mesh hop base cost for each used rate. The output gives us the
Gets the mesh hop base cost for each used rate. The output gives us the
base cost for hops at 54Mbps, 36Mbps, 11Mbps and 1Mbps, in that order.
base cost for hops at 54Mbps, 36Mbps, 11Mbps and 1Mbps, in that order.
The base cost gets divided by a battery state factor to get the actual
The base cost gets divided by a battery state factor to get the actual
cost. A cost of 0 means that rate is deactivated.
cost. A cost of 0 means that rate is deactivated.


iwpriv ethX get_link_costs
iwpriv ethX get_link_costs


set_link_costs "cost54 cost36 cost11 cost1"
set_link_costs "cost54 cost36 cost11 cost1"


Sets the mesh hop base cost for the used speeds. The input parameter
Sets the mesh hop base cost for the used speeds. The input parameter
will specify the cost for hops at 54Mbps, 36Mbps, 11Mbps and 1Mbps, in
will specify the cost for hops at 54Mbps, 36Mbps, 11Mbps and 1Mbps, in
that order. A cost of 0 will disable a specific rate.
that order. A cost of 0 will disable a specific rate.


iwpriv ethX set_link_costs "cost54 cost36 cost11 cost1"
iwpriv ethX set_link_costs "cost54 cost36 cost11 cost1"
</pre>
</pre>


Line 1,071: Line 631:
will be displayed upon completion by use of the getscantable ioctl.
will be displayed upon completion by use of the getscantable ioctl.
</pre>
</pre>
[[Category:Network]]
[[Category:Developers]]

Latest revision as of 00:42, 12 July 2012

  This page is monitored by the OLPC team.

OVERVIEW

This page describes all the mechanisms available to configure the behaviour of the wireless subsystem. Through the times, some of these configuration features were removed from the driver, or implemented in another way. An old version of this page is kept here, as a reference (if you notice that a certain iwpriv command is not available any more, and it is listed in this old version, this means that the command was removed from the driver).

DRIVER LOADING

	
	o. Copy the firmware image (e.g. usb8388.bin) to /lib/firmware/

	o. Load driver by using the following command:
	
		insmod usb8388.ko [fw_name=usb8388.bin]

IWPRIV COMMAND

NAME
	This manual describes the usage of private commands used in Marvell WLAN
	Linux Driver. All the commands available in Wlanconfig will not be available 
	in the iwpriv.


SYNOPSIS
	iwpriv <ethX> <command> [sub-command] ...

Region Commands: 
	iwpriv ethX setregioncode <n>
	iwpriv ethX getregioncode 

LED Behaviour Commands:
	iwpriv ethX ledgpio <n>
	iwpriv ethX ledbhv <n>

WOL (Wake-on-Lan) Filter Commands:
	[TODO: updating this information]
	iwpriv get_wol_rule, iwpriv set_wol_rule, iwpriv reset_wol_rule

Management Frames Control Commands:
	iwpriv bcn_control <n> <m>
	iwpriv setprspretrylt <n>

BT (Blinding Table) Commands:
	The blinding table (BT) contains a list of mac addresses that will be,
	by default, ignored by the firmware. It is also possible to invert this
	behavior so that we will ignore all traffic except for the portion
	coming from mac addresess in the list. It is primarily used for
	debugging and testing networks.  It can be edited and inspected with
	the following commands:

	iwpriv ethX bt_reset
	iwpriv ethX bt_add <mac_address>
	iwpriv ethX bt_del <mac_address>
	iwpriv ethX bt_list <id>
	iwpriv ethX bt_get_invert <n>
	iwpriv ethX bt_set_invert <n>

FWT (Forwarding Table) Commands:
	The forwarding table (FWT) is a feature used to manage mesh network
	routing in the firmware.  The FWT is essentially a routing table that
	associates a destination mac address (da) with a next hop receiver
	address (ra).  The FWT can be inspected and edited with the following
	iwpriv commands, which are described in greater detail below.
	Eventually, the table will be automatically maintained by a custom
	routing protocol.

	NOTE: FWT commands replace the previous DFT commands.  What were the DFT
	commands?, you might ask.  They were an earlier API to the firmware that
	implemented a simple MAC-layer forwarding mechanism.  In the unlikely
	event that you were using these commands, you must migrate to the new
	FWT commands which can be used to achieve the same functionality.

	iwpriv ethX fwt_add [parameters]
	iwpriv ethX fwt_del [parameters]
	iwpriv ethX fwt_lookup [parameters]
	iwpriv ethX fwt_list [parameters]
	iwpriv ethX fwt_list_route [parameters]
	iwpriv ethX fwt_list_neigh [parameters]
	iwpriv ethX fwt_reset [parameters]
	iwpriv ethX fwt_cleanup
	iwpriv ethX fwt_time

MESH Commands:
	The MESH commands are used to configure various features of the mesh
	routing protocol.  The following commands are supported:

	iwpriv ethX mesh_get_ttl
	iwpriv ethX mesh_set_ttl ttl
	iwpriv ethX mesh_get_bcastr rate
	iwpriv ethX mesh_set_bcastr rate
	iwpriv ethX get_rreq_delay
	iwpriv ethX set_rreq_delay delay
	iwpriv ethX get_route_exp
	iwpriv ethX set_route_exp time
	iwpriv ethX get_link_costs
	iwpriv ethX set_link_costs "cost54 cost36 cost11 cost1"

DESCRIPTION
	Those commands are used to send additional commands to the Marvell WLAN
	card via the Linux device driver.

	The ethX parameter specifies the network device that is to be used to 
		perform this command on. it could be eth0, eth1 etc.

	setregioncode           
		This command is used to set the region code in the station.
		where value is 'region code' for various regions like
		USA FCC, Canada IC, Spain, France, Europe ETSI,	Japan ...

		Usage:
			iwpriv ethX setregioncode 0x10: set region code to USA (0x10).

	getregioncode           
		This command is used to get the region code information set in the 
		station. 

	ledgpio
		This command is used to set/get LEDs.

		iwpriv ethX ledgpio <LEDs>
			will set the corresponding LED for the GPIO Line.

		iwpriv ethX ledgpio
			will give u which LEDs are Enabled.

		Usage:
			iwpriv eth1 ledgpio 1 0 2 1 3 4
				will enable 
				LED 1 -> GPIO 0
				LED 2 -> GPIO 1
				LED 3 -> GPIO 4

			iwpriv eth1 ledgpio 
				shows LED information in the format as mentioned above.

		Note: LED0 is invalid
		Note: Maximum Number of LEDs are 16.	

	ledbhv
		This command can be used to change default LEDs behaviors. 
		A given LED behavior can be on, off or blinking. The duty/cycle can be set 
		when behavior is programmed as blinking. 
		
		Usage: 
			1. To get default LED behavior
				iwpriv mshX ledbhv <firmware state> 

			2. To set or change default LED behavior 
				iwpriv mshX ledbhv <firmware state> <lednum> <behavior> <arg> 
				firmware state: The following are some of the relevant states. 
					00: disconnected 
					01: firmware is scanning 
					02: firmware is connected and awake 
					03: firmware is sleeping 
					04: connected deep sleep 
					06: firmware disconnected link lost 
					07: firmware disconnected disassociated 
					09: data transfer while firmware is associated and not scanning. 
					    (If firmware is already in this state, LED behavior does not change
					     on this data transfer). 
					10: firmware idle, not scanning, not disconnected or disassociated.
				lednum: 1 or 2 for first and second LED. 
				behavior: 0 for steady ON, 1 - steady off and 2- blinking. 
				arg: It is used when behavior is 2 to set duty and cycle. It is defined as 
				(duty << 4 | cycle). Here duty could be 0..4 and cycle 0..5 for 34, 
				74, 149, 298, 596, 1192 ms respectively.
				
		Examples: 
			1. To get default behavior for scan
				iwpriv mshX ledbhv 1
			2. To get default behavior while data transfer 
				iwpriv mshX ledbhv 9 
			3. To turn off LED 2 + iwpriv mshX ledbhv 2 2 1 0 
				iwpriv mshX ledbhv 10 2 1 0 
			4. To enable LED 2 and blink LED 1 while data transfer. 
				iwpriv mshX ledbhv 9 2 0 0
				iwpriv mshX ledbhv 9 1 2 4 
			5. To change duty cycle of LED 2 during data transfer 
				iwpriv mshX ledbhv 9 2 2 36 
			6. To turn ON LED 2 when firmware is disassociated/disconnected. 
				iwpriv mshX ledbhv 0 2 0 0  

	bcn_control
		Sets the beacon interval
	
		Usage:
			iwpriv ethX bcn_control 1|0 interval
				1|0 = enable|disable beacons 
				interval is the time between beacons in milliseconds	

	setprspretrylt
		Sets the number of retries for probe responses

		Usage:
			iwpriv ethX setprspretrylt <n>
				n = number of retries (from 0 to 15) 


	fwt_add
		This command is used to insert an entry into the FWT table. The list of 
		parameters must follow the following structure:

		iwpriv ethX fwt_add da ra [metric dir rate ssn dsn hopcount ttl expiration sleepmode snr]

		The parameters between brackets are optional, but they must appear in
		the order specified.  For example, if you want to specify the metric,
		you must also specify the dir, ssn, and dsn but you need not specify the
		hopcount, expiration, sleepmode, or snr.  Any unspecified parameters
		will be assigned the defaults specified below.

		The different parameters are:-
			da		-- DA MAC address in the form 00:11:22:33:44:55
			ra		-- RA MAC address in the form 00:11:22:33:44:55
			metric		-- route metric (cost: smaller-metric routes are
					   preferred, default is 0)
			dir		-- direction (1 for direct, 0 for reverse,
					   default is 1)
			rate		-- data rate used for transmission to the RA,
					   as specified for the rateadapt command,

		ssn		-- Source Sequence Number (time at the RA for
				   reverse routes.  Default is 0)
		dsn		-- Destination Sequence Number (time at the DA
				   for direct routes.  Default is 0)
		hopcount	-- hop count (currently unused, default is 0)
		ttl		-- TTL (Only used in reverse entries)
		expiration	-- entry expiration (in ticks, where a tick is
				   1024us, or ~ 1ms. Use 0 for an indefinite
				   entry, default is 0)
		sleepmode	-- RA's sleep mode (currently unused, default is
				   0)
		snr		-- SNR in the link to RA (currently unused,
				   default is 0)

		The command does not return anything.

	fwt_del
		This command is used to remove an entry to the FWT table. The list of
		parameters must follow the following structure:

		iwpriv ethX fwt_del da ra [dir]

		where the different parameters are:-
			da		-- DA MAC address (in the form "00:11:22:33:44:55")
			ra		-- RA MAC address (in the form "00:11:22:33:44:55")
			dir		-- direction (1 for direct, 0 for reverse,
					   default is 1)

		The command does not return anything.

	fwt_lookup
		This command is used to get the best route in the FWT table to a given
		host. The only parameter is the MAC address of the host that is being
		looked for.

		iwpriv ethX fwt_lookup da

		where:-
			da		-- DA MAC address (in the form "00:11:22:33:44:55")

		The command returns an output string identical to the one returned by
		fwt_list described below.


	fwt_list
		This command is used to list a route from the FWT table. The only
		parameter is the index into the table. If you want to list all the
		routes in a table, start with index=0, and keep listing until you get a
		"(null)" string.  Note that the indicies may change as the fwt is
		updated.  It is expected that most users will not use fwt_list directly,
		but that a utility similar to the traditional route command will be used
		to invoke fwt_list over and over.

		iwpriv ethX fwt_list index

		The output is a string of the following form:

			da ra valid metric dir rate ssn dsn hopcount ttl expiration
			sleepmode snr precursor

		where the different fields are:-
			da		-- DA MAC address (in the form "00:11:22:33:44:55")
			ra		-- RA MAC address (in the form "00:11:22:33:44:55")
			valid		-- whether the route is valid (0 if not valid)
			metric		-- route metric (cost: smaller-metric routes are preferred)
			dir		-- direction (1 for direct, 0 for reverse)
			rate		-- data rate used for transmission to the RA,
					   as specified for the rateadapt command
			ssn		-- Source Sequence Number (time at the RA for reverse routes)
			dsn		-- Destination Sequence Number (time at the DA for direct routes)
			hopcount	-- hop count (currently unused)
			ttl		-- TTL (only used in reverse entries)
			expiration	-- entry expiration (in ticks, where a tick is 1024us, or ~ 1ms. Use 0 for an indefinite entry)
			sleepmode	-- RA's sleep mode (currently unused)
			snr		-- SNR in the link to RA (currently unused)
			precursor	-- predecessor in direct routes

	fwt_list_route
		This command is equivalent to fwt_list.

	fwt_list_neigh
		This command is used to list a neighbor from the FWT table. The only
		parameter is the neighbor ID. If you want to list all the neighbors in a
		table, start with nid=0, and keep incrementing nid until you get a
		"(null)" string.  Note that the nid from a fwt_list_route command can be
		used as an input to this command.  Also note that this command is meant
		mostly for debugging.  It is expected that users will use fwt_lookup.
		One important reason for this is that the neighbor id may change as the
		neighbor table is altered.

		iwpriv ethX fwt_list_neigh nid

		The output is a string of the following form:

			ra sleepmode snr references

		where the different fields are:-
			ra		-- RA MAC address (in the form "00:11:22:33:44:55")
			sleepmode	-- RA's sleep mode (currently unused)
			snr		-- SNR in the link to RA (currently unused)
			references	-- RA's reference counter

	fwt_reset
		This command is used to reset the FWT table, getting rid of all the
		entries. There are no input parameters.

		iwpriv ethX fwt_reset

		The command does not return anything.

	fwt_cleanup
		This command is used to perform user-based garbage recollection. The
		FWT table is checked, and all the entries that are expired or invalid
		are cleaned. Note that this is exported to the driver for debugging
		purposes, as garbage collection is also fired by the firmware when in
		space problems. There are no input parameters.

		iwpriv ethX fwt_cleanup

		The command does returns the number of invalid/expired routes deleted. 

	fwt_time
		This command returns a card's internal time representation.  It is this
		time that is used to represent the expiration times of FWT entries.  The
		number is not consistent from card to card; it is simply a timer count.
		The fwt_time command is used to inspect the timer so that expiration
		times reported by fwt_list can be properly interpreted.

		iwpriv ethX fwt_time

	mesh_get_ttl

		The mesh ttl is the number of hops a mesh packet can traverse before it
		is dropped.  This parameter is used to prevent infinite loops in the
		mesh network.  The value returned by this function is the ttl assigned
		to all mesh packets.  Currently there is no way to control the ttl on a
		per packet or per socket basis.

		iwpriv ethX mesh_get_ttl

	mesh_set_ttl ttl

		Set the ttl.  The argument must be between 0 and 255.

		iwpriv ethX mesh_set_ttl <ttl>

	mesh_get_bcastr
	
		Shows the rate index used for mesh broadcast and multicast packets. The
		mapping to actual rates is the same as for rateadapt command.

		iwpriv ethX mesh_get_bcastr rate

	mesh_set_bcastr rate

		Sets the rate index for mesh broadcast and muticast packets. The mapping
		to actual rates is the same as for rateadapt command.

		iwpriv ethX mesh_set_bcastr rate

	get_rreq_delay
	
		Shows the delay to forward a RREQ frame. This delay allows the node to
		forward just the best route in case the same RREQ arrives to the node
		through different routes. The argument is shown in 1/100 seconds.

		iwpriv ethX get_rreq_delay

	set_rreq_delay delay

		Sets the RREQ forward delay. The delay is interpreted as 1/100 seconds. 

		iwpriv ethX set_rreq_delay delay

	get_route_exp

		Shows the mesh route expiration time, in seconds.

		iwpriv ethX get_route_exp

	set_route_exp time

		Gets the mesh route, expiration time, in seconds.

		iwpriv ethX set_route_exp time

	get_link_costs

		Gets the mesh hop base cost for each used rate. The output gives us the
		base cost for hops at 54Mbps, 36Mbps, 11Mbps and 1Mbps, in that order.
		The base cost gets divided by a battery state factor to get the actual
		cost. A cost of 0 means that rate is deactivated.

		iwpriv ethX get_link_costs

	set_link_costs "cost54 cost36 cost11 cost1"

		Sets the mesh hop base cost for the used speeds. The input parameter
		will specify the cost for hops at 54Mbps, 36Mbps, 11Mbps and 1Mbps, in
		that order. A cost of 0 will disable a specific rate.

		iwpriv ethX set_link_costs "cost54 cost36 cost11 cost1"

ETHTOOL

Use the -i option to retrieve version information from the driver.

# ethtool -i eth0
driver: libertas
version: COMM-USB8388-318.p4
firmware-version: 5.110.7
bus-info:

Use the -e option to read the EEPROM contents of the card.

	Usage:
	ethtool -e ethX [raw on|off] [offset N] [length N]

       -e     retrieves and prints an EEPROM dump for the  specified  ethernet
              device.   When raw is enabled, then it dumps the raw EEPROM data
              to stdout. The length and offset parameters allow  dumping  cer-
              tain portions of the EEPROM.  Default is to dump the entire EEP-
              ROM.

# ethtool -e eth0 offset 0 length 16
Offset          Values
------          ------
0x0000          38 33 30 58 00 00 34 f4 00 00 10 00 00 c4 17 00

DEBUGFS COMMANDS

those commands are used via debugfs interface

rdmac 
rdbbp
rdrf	
	These commands are used to read the MAC, BBP and RF registers from the 
	card.  These commands take one parameter that specifies the offset 
	location that is to be read.  This parameter must be specified in 
	hexadecimal (its possible to preceed preceding the number with a "0x").

	Path: /debugfs/libertas_wireless/ethX/registers/
		
	Usage:	
		echo "0xa123" > rdmac ; cat rdmac
		echo "0xa123" > rdbbp ; cat rdbbp
		echo "0xa123" > rdrf ; cat rdrf
wrmac 
wrbbp
wrrf	
	These commands are used to write the MAC, BBP and RF registers in the 
	card.  These commands take two parameters that specify the offset 
	location and the value that is to be written. This parameters must 
	be specified in hexadecimal (its possible to preceed the number 
	with a "0x").
	
	Usage:
		echo "0xa123 0xaa" > wrmac
		echo "0xa123 0xaa" > wrbbp
		echo "0xa123 0xaa" > wrrf

sleepparams       
	This command is used to set the sleepclock configurations

	Path: /debugfs/libertas_wireless/ethX/
	
	Usage:
		cat sleepparams: reads the current sleepclock configuration

		echo "p1 p2 p3 p4 p5 p6" > sleepparams: writes the sleepclock configuration.
			
		where:
			p1 is Sleep clock error in ppm (0-65535)
			p2 is Wakeup offset in usec (0-65535)
			p3 is Clock stabilization time in usec (0-65535)
			p4 is Control periodic calibration (0-2)
			p5 is Control the use of external sleep clock (0-2)
			p6 is reserved for debug (0-65535)

subscribed_events

	The subscribed_events directory contains the interface for the
	subscribed events API.

	Path: /debugfs/libertas_wireless/ethX/subscribed_events/

	Each event is represented by a filename. Each filename consists of the
	following three fields:
	Value Frequency Subscribed

	To read the current values for a given event, do:
		cat event
	To set the current values, do:
		echo "60 2 1" > event

	Frequency field specifies the reporting frequency for this event.
	If it is set to 0, then the event is reported only once, and then
	automatically unsubscribed. If it is set to 1, then the event is
	reported every time it occurs. If it is set to N, then the event is
	reported every Nth time it occurs.

	beacon_missed 
	Value field specifies the number of consecutive missing beacons which
	triggers the LINK_LOSS event. This event is generated only once after
	which the firmware resets its state. At initialization, the LINK_LOSS
	event is subscribed by default. The default value of MissedBeacons is
	60.

	failure_count
	Value field specifies the consecutive failure count threshold which
	triggers the generation of the MAX_FAIL event. Once this event is
	generated, the consecutive failure count is reset to 0. 
	At initialization, the MAX_FAIL event is NOT subscribed by
	default.

	high_rssi
	This event is generated when the average received RSSI in beacons goes
	above a threshold, specified by Value.

	low_rssi
	This event is generated when the average received RSSI in beacons goes
	below a threshold, specified by Value.

	high_snr
	This event is generated when the average received SNR in beacons goes
	above a threshold, specified by Value.

	low_snr
	This event is generated when the average received SNR in beacons goes
	below a threshold, specified by Value.

extscan
	This command is used to do a specific scan.

	Path: /debugfs/libertas_wireless/ethX/
	
	Usage: echo "SSID" > extscan

	Example:
		echo "LINKSYS-AP" > extscan

	To see the results of use getscantable command.

getscantable

	Display the current contents of the driver scan table (ie. get the
	scan results).

	Path: /debugfs/libertas_wireless/ethX/

	Usage:
		cat getscantable

setuserscan
	Initiate a customized scan and retrieve the results


	Path: /debugfs/libertas_wireless/ethX/

    Usage:
       echo "[ARGS]" > setuserscan

         where [ARGS]: 

      chan=[chan#][band][mode] where band is [a,b,g] and mode is 
                               blank for active or 'p' for passive
      bssid=xx:xx:xx:xx:xx:xx  specify a BSSID filter for the scan
      ssid="[SSID]"            specify a SSID filter for the scan
      keep=[0 or 1]            keep the previous scan results (1), discard (0)
      dur=[scan time]          time to scan for each channel in milliseconds
      probes=[#]               number of probe requests to send on each chan
      type=[1,2,3]             BSS type: 1 (Infra), 2(Adhoc), 3(Any)
 
    Any combination of the above arguments can be supplied on the command line.
      If the chan token is absent, a full channel scan will be completed by 
      the driver.  If the dur or probes tokens are absent, the driver default
      setting will be used.  The bssid and ssid fields, if blank, 
      will produce an unfiltered scan. The type field will default to 3 (Any)
      and the keep field will default to 0 (Discard).

    Examples:
    1) Perform an active scan on channels 1, 6, and 11 in the 'g' band:
            echo "chan=1g,6g,11g" > setuserscan

    2) Perform a passive scan on channel 11 for 20 ms:
            echo "chan=11gp dur=20" > setuserscan

    3) Perform an active scan on channels 1, 6, and 11; and a passive scan on
       channel 36 in the 'a' band:
	
            echo "chan=1g,6g,11g,36ap" > setuserscan

    4) Perform an active scan on channel 6 and 36 for a specific SSID:
            echo "chan=6g,36a ssid="TestAP"" > setuserscan

    5) Scan all available channels (B/G, A bands) for a specific BSSID, keep
       the current scan table intact, update existing or append new scan data:
            echo "bssid=00:50:43:20:12:82 keep=1" > setuserscan

    6) Scan channel 6, for all infrastructure networks, sending two probe 
       requests.  Keep the previous scan table intact. Update any duplicate
       BSSID/SSID matches with the new scan data:
            echo "chan=6g type=1 probes=2 keep=1" > setuserscan

    All entries in the scan table (not just the new scan data when keep=1) 
    will be displayed upon completion by use of the getscantable ioctl.