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NAME

       crda  - send to the kernel a wireless regulatory domain for a given ISO
       / IEC 3166 alpha2

SYNOPSIS

       crda

Description

       crda is the Linux wireless central regulatory domain agent.  crda is
       intended to be used by udev scripts and should not be run manually
       unless debugging udev scripts.  crda is triggered to run by the kernel
       by sending a udev event upon a new regulatory domain change. Regulatory
       domain changes are triggered by the wireless kernel subsystem (upon
       initialization and on reception of country IEs), wireless drivers, or
       userspace (see iw ). Upon a regulatory domain change the kernel sends a
       udev change event for the regulatory platform. The kernel ignores
       regulatory domains sent to it if it does not expect them. The
       regulatory domain is read by crda from the regulatory.bin file.

RSA Digital Signature

       If built with openssl or gcrypt support crda will have embedded into it
       an RSA digital signature which will prevent it from reading corrupted
       or non-authored regulatory.bin files. Authorship is respected by the
       RSA public key packed into crda.  This specific crda package has been
       built with an RSA public key from John Linville (the Linux wireless
       kernel maintainer) and as such will only read regulatory.bin files
       signed by him. For further information see the regulatory.bin man page.

UDEV RULE

       A udev regulatory rule must be put in place in order to receive and
       parse udev events from the kernel in order to get udev to call crda
       with the passed ISO / IEC 3166 alpha2 country code.  An example udev
       rule which can be used (usually in
       /lib/udev/rules.d/85-regulatory.rules ):

       KERNEL=="regulatory*", ACTION=="change", SUBSYSTEM=="platform",
       RUN+="/sbin/crda"

Environment variable

       Set the COUNTRY environment variable with a specific ISO / IEC 3166
       alpha2 country code and then run crda without arguments. This will send
       a regulatory domain for that alpha2 to the kernel.

SEE ALSO

       iw(8) regulatory.bin(5)

       http://wireless.kernel.org/en/developers/Regulatory/