/share/man/man9/ieee80211_regdomain.9
https://bitbucket.org/freebsd/freebsd-head/ · Unknown · 143 lines · 143 code · 0 blank · 0 comment · 0 complexity · 52cda53a798de6251d170b2e76010e2a MD5 · raw file
- .\"
- .\" Copyright (c) 2009 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.
- .\" 2. Redistributions in binary form must reproduce the above copyright
- .\" notice, this list of conditions and the following disclaimer in the
- .\" documentation and/or other materials provided with the distribution.
- .\"
- .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
- .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- .\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
- .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, 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 DAMAGE.
- .\"
- .\" $FreeBSD$
- .\"
- .Dd August 4, 2009
- .Dt IEEE80211_REGDOMAIN 9
- .Os
- .Sh NAME
- .Nm ieee80211_regdomain
- .Nd 802.11 regulatory support
- .Sh SYNOPSIS
- .In net80211/ieee80211_var.h
- .In net80211/ieee80211_regdomain.h
- .Pp
- .Ft int
- .Fo ieee80211_init_channels
- .Fa "struct ieee80211com *"
- .Fa "const struct ieee80211_regdomain *"
- .Fa "const uint8_t bands[]"
- .Fc
- .\"
- .Ft void
- .Fo ieee80211_sort_channels
- .Fa "struct ieee80211_channel *"
- .Fa "int nchans"
- .Fc
- .\"
- .Ft "struct ieee80211_appie *"
- .Fn ieee80211_alloc_countryie "struct ieee80211com *"
- .Sh DESCRIPTION
- The
- .Nm net80211
- software layer provides a support framework for drivers that includes
- comprehensive regulatory support.
- .Nm net80211
- provides mechanisms that enforce
- .Em "regulatory policy"
- by privileged user applications.
- .Pp
- Drivers define a device's capabilities and can
- intercept and control regulatory changes requested through
- .Nm net80211 .
- The initial regulatory state, including the channel list, must be
- filled in by the driver before calling
- .Fn ieee80211_ifattach .
- The channel list should reflect the set of channels the device is
- .Em calibrated
- for use on.
- This list may also be requested later through the
- .Vt ic_getradiocaps
- method in the
- .Vt ieee80211com
- structure.
- The
- .Fn ieee80211_init_channels
- function is provided as a rudimentary fallback for drivers that do not
- (or cannot) fill in a proper channel list.
- Default regulatory state is supplied such as the regulatory SKU,
- ISO country code, location (e.g. indoor, outdoor), and a set of
- frequency bands the device is capable of operating on.
- .Nm net80211
- populates the channel table in
- .Vt ic_channels
- with a default set of channels and capabilities.
- Note this mechanism should be used with care as any mismatch between
- the channel list created and the device's capabilities can result
- in runtime errors (e.g. a request to operate on a channel the device
- does not support).
- The SKU and country information are used for generating 802.11h protocol
- elements and related operation such as for 802.11d; mis-setup by a
- driver is not fatal, only potentially confusing.
- .Pp
- Devices that do not have a fixed/default regulatory state can set
- the regulatory SKU to
- .Dv SKU_DEBUG
- and country code to
- .Dv CTRY_DEFAULT
- and leave proper setup to user applications.
- If default settings are known they can be installed and/or an event
- can be dispatched to user space using
- .Fn ieee80211_notify_country
- so that
- .Xr devd 8
- will do the appropriate setup work at system boot (or device insertion).
- .Pp
- The channel table is sorted to optimize lookups using the
- .Fn ieee80211_sort_channels
- routine.
- This should be done whenever the channel table contents are modified.
- .Pp
- The
- .Fn ieee80211_alloc_countryie
- function allocates an information element as specified by 802.11h.
- Because this is expensive to generate it is cached in
- .Vt ic_countryie
- and generated only when regulatory state changes.
- Drivers that call
- .Fn ieee80211_alloc_countryie
- directly should not help with this caching; doing so may confuse the
- .Nm net80211
- layer.
- .Sh DRIVER REGULATORY CONTROL
- Drivers can control regulatory change requests by overriding the
- .Vt ic_setregdomain
- method that checks change requests.
- While drivers can reject any request that does not meet its requirements
- it is recommended that one be lenient in what is accepted and, whenever
- possible, instead of rejecting a request, alter it to be correct.
- For example, if the transmit power cap for a channel is too high the
- driver can either reject the request or (better) reduce the cap to be
- compliant.
- Requests that include unacceptable channels should cause the request
- to be rejected as otherwise a mismatch may be created between application
- state and the state managed by
- .Nm net80211 .
- The exact rules by which to operate are still being codified.
- .Sh SEE ALSO
- .Xr regdomain 5 ,
- .Xr ifconfig 8 ,
- .Xr ieee80211 9