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/
