[wireless-regdb] [RFC] [PATCH] crda: enforce ETSI CAC timer of 600s on the weather band

[Seth Forshee]

On Mon, Apr 13, 2015 at 05:31:14PM +0200, Jean-Pierre Tosoni wrote:
> A really weird patch that splits the U-NII-2e band into 1, 2 or 3
> sub-bands to enforce a CAC time of 10 minutes in the range 5600-5650 MHz.

Wrong maintainer / list. CRDA patches should be directed to Luis and the
linux-wireless list (feel free to Cc wireless-regdb if you like).

Seth

> ---
> 
> I came with the following patch to enforce ETSI regulation in Europe for
> weather channels.
> It applies to crda and when it encounters this frequency range, it splits it
> out and enforces the 10 minutes CAC.
> I know it's weird as is, I just wonder if it's the good way of solving this
> until CAC is in regulatory.bin or the kernel takes care of it.
> 
>  crda.c |  104
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++------
>  1 files changed, 94 insertions(+), 10 deletions(-)
> 
> diff --git a/crda.c b/crda.c
> index f40131f..4c4aeba 100644
> --- a/crda.c
> +++ b/crda.c
> @@ -140,6 +140,36 @@ nla_put_failure:
>  	return -1;
>  }
>  
> +static int put_dom_reg_rule(struct ieee80211_reg_rule *rule, struct nl_msg
> *msg, int i)
> +{
> +	int r;
> +	struct nlattr *nl_reg_rule;
> +	unsigned long width;
> +
> +	width = rule->freq_range.end_freq_khz -
> rule->freq_range.start_freq_khz;
> +	if (width <= 0)
> +		return 0; // nothing to do -- assert success
> +
> +	nl_reg_rule = nla_nest_start(msg, i);
> +	if (!nl_reg_rule)
> +		return 1;
> +
> +	if (width < rule->freq_range.max_bandwidth_khz) {
> +		if (width >= 160000) rule->freq_range.max_bandwidth_khz =
> 160000;
> +		else if (width >= 80000) rule->freq_range.max_bandwidth_khz
> = 80000;
> +		else if (width >= 40000) rule->freq_range.max_bandwidth_khz
> = 40000;
> +		else if (width >= 20000) rule->freq_range.max_bandwidth_khz
> = 20000;
> +		else if (width >= 10000) rule->freq_range.max_bandwidth_khz
> = 10000;
> +		else rule->freq_range.max_bandwidth_khz = 5000;
> +	}
> +	r = put_reg_rule(rule, msg);
> +	if (r)
> +		return 1;
> +
> +	nla_nest_end(msg, nl_reg_rule);
> +	return 0;
> +}
> +
>  int main(int argc, char **argv)
>  {
>  	int fd = -1;
> @@ -228,16 +258,70 @@ int main(int argc, char **argv)
>  	}
>  
>  	for (j = 0; j < rd->n_reg_rules; j++) {
> -		struct nlattr *nl_reg_rule;
> -		nl_reg_rule = nla_nest_start(msg, i);
> -		if (!nl_reg_rule)
> -			goto nla_put_failure;
> -
> -		r = put_reg_rule(&rd->reg_rules[j], msg);
> -		if (r)
> -			goto nla_put_failure;
> -
> -		nla_nest_end(msg, nl_reg_rule);
> +		const struct ieee80211_reg_rule *rule = &rd->reg_rules[j];
> +
> +#define METEO_BAND_START	(5600 * 1000)
> +#define METEO_BAND_BEFORE_START	(5570 * 1000)	// to allow BW=40
> and 80
> +#define METEO_BAND_END		(5650 * 1000)
> +		if (rd->dfs_region == REGDB_DFS_ETSI
> +		  && rule->freq_range.start_freq_khz < METEO_BAND_END
> +		  && rule->freq_range.end_freq_khz > METEO_BAND_START) {
> +			struct ieee80211_reg_rule split_rule;
> +			/*
> +			 * ETSI rule including all or part of the weather
> band
> +			 *
> +			 * If necessary the frequency range is split in 3
> +			 * to allow inserting the 10 minutes CAC in the 2nd
> one
> +			 */
> +			/* If the range overlaps the 5600 MHz frequency */
> +			if (rule->freq_range.start_freq_khz <
> METEO_BAND_BEFORE_START) {
> +
> +				/* copy band data (CAC, BW...) */
> +				split_rule = *rule;
> +				/* remove upper channels */
> +				split_rule.freq_range.end_freq_khz =
> METEO_BAND_BEFORE_START;
> +
> +				/* configure lower channels */
> +				if (put_dom_reg_rule(&split_rule, msg, i))
> +					goto nla_put_failure;
> +			}
> +
> +			/* The rest necessarily begins before 5650 MHz */
> +			/* copy band data (CAC, BW...) */
> +			split_rule = *rule;
> +			if (rule->freq_range.start_freq_khz <
> METEO_BAND_BEFORE_START) {
> +				split_rule.freq_range.start_freq_khz =
> METEO_BAND_BEFORE_START;
> +			}
> +
> +			/* compute center range */
> +			if (rule->freq_range.end_freq_khz <= METEO_BAND_END)
> +				split_rule.freq_range.end_freq_khz =
> rule->freq_range.end_freq_khz;
> +			else
> +				split_rule.freq_range.end_freq_khz =
> METEO_BAND_END;
> +			split_rule.dfs_cac_ms = 10 * 60 * 1000; /* 10
> minutes */
> +
> +			/* configure weather frequencies */
> +			if (put_dom_reg_rule(&split_rule, msg, i))
> +				goto nla_put_failure;
> +
> +			/* If the range overlaps the 5650 MHz frequency */
> +			if (rule->freq_range.end_freq_khz > METEO_BAND_END)
> {
> +
> +				/* copy band data (CAC, BW...) */
> +				split_rule = *rule; /* copie les donnees de
> la bande */
> +				/* remove lower channels */
> +				split_rule.freq_range.start_freq_khz =
> METEO_BAND_END;
> +
> +				/* configure higher channels */
> +				if (put_dom_reg_rule(&split_rule, msg, i))
> +					goto nla_put_failure;
> +			}
> +		} else {
> +			/* configure the whole range */
> +			/* WARNING: this fonction may change
> (const)rule->...max_bandwidth_khz */
> +			if (put_dom_reg_rule((struct ieee80211_reg_rule
> *)rule, msg, i))
> +				goto nla_put_failure;
> +		}
>  	}
>  
>  	nla_nest_end(msg, nl_reg_rules);
> -- 
> 1.7.2.5
> 
>