CRDA(8)                 (23 January 2009)                 CRDA(8)

     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 ini-
          tialization 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 regula-
          tory 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
          RSA public keys from John Linville (the Linux wireless
          kernel and Seth Forshee (the wireless regulatory databse and
          as such will only read regulatory.bin files signed by one of
          them. 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 (usu-
          ally in /lib/udev/rules.d/85-regulatory.rules ):

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

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     CRDA(8)                 (23 January 2009)                 CRDA(8)

     Environment variable
          Set the COUNTRY environment variable with a specific ISO /
          IEC 3166 alpha2 country code and then run crda without argu-
          ments. 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/

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