[RFC PATCH 1/2] cfg80211: Add support for ITS-G5 band (5.9 GHz)

[RFC PATCH 1/2] cfg80211: Add support for ITS-G5 band (5.9 GHz)

[Jan Kaisrlik]

The patch adds support for Intelligent Transportation System (ITS-G5)
band as defined by ETSI EN 302 663 standard. This band is enabled by
a new configuration option CFG80211_REG_ITSG5_BAND, which depends on
CFG80211_CERTIFICATION_ONUS.

Signed-off-by: Jan Kaisrlik <kaisrja1@fel.cvut.cz>
Cc: Michal Sojka <sojkam1@fel.cvut.cz>
---
 include/uapi/linux/nl80211.h |  2 ++
 net/wireless/Kconfig         | 21 +++++++++++++++++++++
 net/wireless/reg.c           |  4 ++++
 3 files changed, 27 insertions(+)

diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index c0ab6b0..9defe0a 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -2838,6 +2838,7 @@ enum nl80211_sched_scan_match_attr {
  * @NL80211_RRF_NO_HT40PLUS: channels can't be used in HT40+ operation
  * @NL80211_RRF_NO_80MHZ: 80MHz operation not allowed
  * @NL80211_RRF_NO_160MHZ: 160MHz operation not allowed
+ * @NL80211_RRF_ITSG5: band is reserved for Intelligent Transportation System
  */
 enum nl80211_reg_rule_flags {
 	NL80211_RRF_NO_OFDM		= 1<<0,
@@ -2855,6 +2856,7 @@ enum nl80211_reg_rule_flags {
 	NL80211_RRF_NO_HT40PLUS		= 1<<14,
 	NL80211_RRF_NO_80MHZ		= 1<<15,
 	NL80211_RRF_NO_160MHZ		= 1<<16,
+	NL80211_RRF_ITSG5		= 1<<17,
 };
 
 #define NL80211_RRF_PASSIVE_SCAN	NL80211_RRF_NO_IR
diff --git a/net/wireless/Kconfig b/net/wireless/Kconfig
index 4f5543d..2f7767c 100644
--- a/net/wireless/Kconfig
+++ b/net/wireless/Kconfig
@@ -132,6 +132,27 @@ config CFG80211_REG_RELAX_NO_IR
 	 support this feature by declaring the appropriate channel flags and
 	 capabilities in their registration flow.
 
+config CFG80211_REG_ITSG5_BAND
+	bool "cfg80211 support for ITS-G5 bands (5.9 GHz)"
+	def_bool n
+	depends on CFG80211_CERTIFICATION_ONUS
+	---help---
+	This option enables support for Inteligent Transportation System (ITS)
+	band 5.855 to 5.925 GHz. The band is standardized for Europe in the ETSI
+	EN 302 663 standard. This band is split into several sub-bands:
+
+	- ITS-G5A (5.875 to 5.905 GHz) band is reserved for ITS road safety
+	  related applications and is regulated by Commission Decision 2008/671/EC.
+
+	- ITS-G5B (5.855 to 5.875 GHz) band is reserved for ITS non-safety
+	  applications and is regulated by ECC Recommendation ECC/REC/(08)01.
+
+	- ITS-G5D (5.905 to 5.925 GHz) band is reserved for future ITS
+	  applications and is regulated by ECC Decision ECC/DEC(02)01.
+
+	Enable this option only if you work on the above mentioned applications
+	and comply with the regulatory documents.
+
 config CFG80211_DEFAULT_PS
 	bool "enable powersave by default"
 	depends on CFG80211
diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index 2510b231..82e7b3b 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -1020,6 +1020,10 @@ freq_reg_info_regd(struct wiphy *wiphy, u32 center_freq,
 		rr = &regd->reg_rules[i];
 		fr = &rr->freq_range;
 
+		if (!config_enabled(CONFIG_CFG80211_REG_ITSG5_BAND) &&
+			 (rr->flags & NL80211_RRF_ITSG5))
+			return ERR_PTR(-EPERM);
+
 		/*
 		 * We only need to know if one frequency rule was
 		 * was in center_freq's band, that's enough, so lets
-- 
2.1.4

[RFC PATCH 2/2] ath9k: Add support for ITS-G5 band (5.9 GHz)

[Jan Kaisrlik]

The patch adds support for Inteligent Transportation System (ITS-G5)
band to the ath9k drivers.

Signed-off-by: Jan Kaisrlik <kaisrja1@fel.cvut.cz>
Cc: Michal Sojka <sojkam1@fel.cvut.cz>
---
 drivers/net/wireless/ath/ath9k/common-init.c | 21 +++++++++++++++++++++
 drivers/net/wireless/ath/ath9k/hw.h          |  6 +++++-
 drivers/net/wireless/ath/regd.c              | 18 +++++++++++++-----
 3 files changed, 39 insertions(+), 6 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/common-init.c b/drivers/net/wireless/ath/ath9k/common-init.c
index a006c14..0f630b1 100644
--- a/drivers/net/wireless/ath/ath9k/common-init.c
+++ b/drivers/net/wireless/ath/ath9k/common-init.c
@@ -86,6 +86,27 @@ static const struct ieee80211_channel ath9k_5ghz_chantable[] = {
 	CHAN5G(5785, 35), /* Channel 157 */
 	CHAN5G(5805, 36), /* Channel 161 */
 	CHAN5G(5825, 37), /* Channel 165 */
+
+#ifdef CONFIG_CFG80211_REG_ITSG5_BAND
+	/* ITS-G5B */
+	CHAN5G(5855, 38), /* Channel 171 */
+	CHAN5G(5860, 39), /* Channel 172 */
+	CHAN5G(5865, 40), /* Channel 173 */
+	CHAN5G(5870, 41), /* Channel 174 */
+	/* ITS-G5A */
+	CHAN5G(5875, 42), /* Channel 175 */
+	CHAN5G(5880, 43), /* Channel 176 */
+	CHAN5G(5885, 44), /* Channel 177 */
+	CHAN5G(5890, 45), /* Channel 178 */
+	CHAN5G(5895, 46), /* Channel 179 */
+	CHAN5G(5900, 47), /* Channel 180 */
+	CHAN5G(5905, 48), /* Channel 181 */
+	/* ITS-G5D */
+	CHAN5G(5910, 49), /* Channel 182 */
+	CHAN5G(5915, 50), /* Channel 183 */
+	CHAN5G(5920, 51), /* Channel 184 */
+	CHAN5G(5925, 52), /* Channel 185 */
+#endif
 };
 
 /* Atheros hardware rate code addition for short premble */
diff --git a/drivers/net/wireless/ath/ath9k/hw.h b/drivers/net/wireless/ath/ath9k/hw.h
index e8454db..38da6780 100644
--- a/drivers/net/wireless/ath/ath9k/hw.h
+++ b/drivers/net/wireless/ath/ath9k/hw.h
@@ -73,7 +73,11 @@
 
 #define ATH9K_RSSI_BAD			-128
 
-#define ATH9K_NUM_CHANNELS	38
+#ifdef CONFIG_CFG80211_REG_ITSG5_BAND
+#define ATH9K_NUM_CHANNELS		53
+#else
+#define ATH9K_NUM_CHANNELS		38
+#endif
 
 /* Register read/write primitives */
 #define REG_WRITE(_ah, _reg, _val) \
diff --git a/drivers/net/wireless/ath/regd.c b/drivers/net/wireless/ath/regd.c
index 06ea6cc..28bbbe0 100644
--- a/drivers/net/wireless/ath/regd.c
+++ b/drivers/net/wireless/ath/regd.c
@@ -50,6 +50,9 @@ static int __ath_regd_init(struct ath_regulatory *reg);
 #define ATH9K_5GHZ_5725_5850	REG_RULE(5725-10, 5850+10, 80, 0, 30,\
 					 NL80211_RRF_NO_IR)
 
+#define ATH9K_5GHZ_ITSG5	REG_RULE(5855-5, 5925+5, 10, 0, 33,\
+					 NL80211_RRF_ITSG5)
+
 #define ATH9K_2GHZ_ALL		ATH9K_2GHZ_CH01_11, \
 				ATH9K_2GHZ_CH12_13, \
 				ATH9K_2GHZ_CH14
@@ -64,53 +67,58 @@ static int __ath_regd_init(struct ath_regulatory *reg);
 /* Can be used for:
  * 0x60, 0x61, 0x62 */
 static const struct ieee80211_regdomain ath_world_regdom_60_61_62 = {
-	.n_reg_rules = 5,
+	.n_reg_rules = 6,
 	.alpha2 =  "99",
 	.reg_rules = {
 		ATH9K_2GHZ_ALL,
 		ATH9K_5GHZ_ALL,
+		ATH9K_5GHZ_ITSG5,
 	}
 };
 
 /* Can be used by 0x63 and 0x65 */
 static const struct ieee80211_regdomain ath_world_regdom_63_65 = {
-	.n_reg_rules = 4,
+	.n_reg_rules = 5,
 	.alpha2 =  "99",
 	.reg_rules = {
 		ATH9K_2GHZ_CH01_11,
 		ATH9K_2GHZ_CH12_13,
 		ATH9K_5GHZ_NO_MIDBAND,
+		ATH9K_5GHZ_ITSG5,
 	}
 };
 
 /* Can be used by 0x64 only */
 static const struct ieee80211_regdomain ath_world_regdom_64 = {
-	.n_reg_rules = 3,
+	.n_reg_rules = 4,
 	.alpha2 =  "99",
 	.reg_rules = {
 		ATH9K_2GHZ_CH01_11,
 		ATH9K_5GHZ_NO_MIDBAND,
+		ATH9K_5GHZ_ITSG5,
 	}
 };
 
 /* Can be used by 0x66 and 0x69 */
 static const struct ieee80211_regdomain ath_world_regdom_66_69 = {
-	.n_reg_rules = 3,
+	.n_reg_rules = 4,
 	.alpha2 =  "99",
 	.reg_rules = {
 		ATH9K_2GHZ_CH01_11,
 		ATH9K_5GHZ_ALL,
+		ATH9K_5GHZ_ITSG5,
 	}
 };
 
 /* Can be used by 0x67, 0x68, 0x6A and 0x6C */
 static const struct ieee80211_regdomain ath_world_regdom_67_68_6A_6C = {
-	.n_reg_rules = 4,
+	.n_reg_rules = 5,
 	.alpha2 =  "99",
 	.reg_rules = {
 		ATH9K_2GHZ_CH01_11,
 		ATH9K_2GHZ_CH12_13,
 		ATH9K_5GHZ_ALL,
+		ATH9K_5GHZ_ITSG5,
 	}
 };
 
-- 
2.1.4

Re: [RFC PATCH 1/2] cfg80211: Add support for ITS-G5 band (5.9 GHz)

[Johannes Berg]

On Fri, 2015-10-16 at 13:28 +0200, Jan Kaisrlik wrote:
> The patch adds support for Intelligent Transportation System (ITS-G5)
> band as defined by ETSI EN 302 663 standard. This band is enabled by
> a new configuration option CFG80211_REG_ITSG5_BAND, which depends on
> CFG80211_CERTIFICATION_ONUS.

That Kconfig option seems unnecessary - after all, the regulatory
database still has a say in this?

Even the NL80211_RRF_ITSG5 flag seems somewhat unnecessary - if the
regulatory database did in fact provide information on these channels,
then we can assume they're usable, no?

IOW - I don't really see the point of this patch - can't we treat these
channels just like regular ones, and rely on the regulatory information
to prevent their use in all but special scenarios (where the integrator
is providing a proper database)?

johannes

Re: [RFC PATCH 1/2] cfg80211: Add support for ITS-G5 band (5.9 GHz)

[Michal Sojka]

Hi all,

(I added wireless-regdb@lists.infradead.org to recipients, the original
mail is at http://marc.info/?l=linux-wireless&m=144499490005262)

On Fri, Oct 16 2015, Johannes Berg wrote:
> On Fri, 2015-10-16 at 13:28 +0200, Jan Kaisrlik wrote:
>> The patch adds support for Intelligent Transportation System (ITS-G5)
>> band as defined by ETSI EN 302 663 standard. This band is enabled by
>> a new configuration option CFG80211_REG_ITSG5_BAND, which depends on
>> CFG80211_CERTIFICATION_ONUS.
>
> That Kconfig option seems unnecessary - after all, the regulatory
> database still has a say in this?

I thought that the regdb is for unlicensed bands with unrestricted use.
The 5.9 GHz band is not licensed but it is restricted for ITS
applications. In http://marc.info/?l=linux-wireless&m=140183393707445&w=2
Luis Rodriguez suggested that having a Kconfig option may be the way to
go, but we may misread what he was saying.

I assume that if this band will be in regdb, it will be too easy to use
this band (e.g. by mistake) for non-ITS applications.

> Even the NL80211_RRF_ITSG5 flag seems somewhat unnecessary - if the
> regulatory database did in fact provide information on these channels,
> then we can assume they're usable, no?
>
> IOW - I don't really see the point of this patch - can't we treat these
> channels just like regular ones, and rely on the regulatory information
> to prevent their use in all but special scenarios (where the integrator
> is providing a proper database)?

Our goal is to make it easier for people to experiment with ITS in
controlled environment (e.g. in a university lab). So you suggest that
this should be enabled by providing custom regdb rather than recompiling
the kernel with CFG80211_CERTIFICATION_ONUS?

-Michal

Re: [RFC PATCH 1/2] cfg80211: Add support for ITS-G5 band (5.9 GHz)

[Johannes Berg]

Hi,

> I thought that the regdb is for unlicensed bands with unrestricted use.
> The 5.9 GHz band is not licensed but it is restricted for ITS
> applications. 

It kind of is, at least the current one is.

> In http://marc.info/?l=linux-wireless&m=140183393707445&w=2
> Luis Rodriguez suggested that having a Kconfig option may be the way to
> go, but we may misread what he was saying.

I didn't really follow this.

> I assume that if this band will be in regdb, it will be too easy to use
> this band (e.g. by mistake) for non-ITS applications.

Does the *regulatory* actually prohibit that anyway though?

> Our goal is to make it easier for people to experiment with ITS in
> controlled environment (e.g. in a university lab). So you suggest that
> this should be enabled by providing custom regdb rather than recompiling
> the kernel with CFG80211_CERTIFICATION_ONUS?

Yes, that was exactly my thought.

johannes

Re: [RFC PATCH 1/2] cfg80211: Add support for ITS-G5 band (5.9 GHz)

[Michal Sojka]

On Fri, Oct 16 2015, Johannes Berg wrote:
> Hi,
>
>> I thought that the regdb is for unlicensed bands with unrestricted use.
>> The 5.9 GHz band is not licensed but it is restricted for ITS
>> applications. 
>
> It kind of is, at least the current one is.
>
>> In http://marc.info/?l=linux-wireless&m=140183393707445&w=2
>> Luis Rodriguez suggested that having a Kconfig option may be the way to
>> go, but we may misread what he was saying.
>
> I didn't really follow this.
>
>> I assume that if this band will be in regdb, it will be too easy to use
>> this band (e.g. by mistake) for non-ITS applications.
>
> Does the *regulatory* actually prohibit that anyway though?

Regulatory (ECC Decision (08)01) reads:

    ... decides ... that CEPT administrations shall designate the
    frequency sub-band 5875-5905 MHz on a non-exclusive basis for ITS
    traffic safety applications;

I'm not sure about the exact meaning of words "designate" and
"non-exclusive". If anyone can clarify that for me, I'd appreciate it. I
tend to understand that this band can be only used by ITS applications
(without license) or by other devices that have a proper license.

Thanks.
-Michal