cfg80211: Add new wireless regulatory infrastructure

This adds the new wireless regulatory infrastructure. The
main motiviation behind this was to centralize regulatory
code as each driver was implementing their own regulatory solution,
and to replace the initial centralized code we have where:

* only 3 regulatory domains are supported: US, JP and EU
* regulatory domains can only be changed through module parameter
* all rules were built statically in the kernel

We now have support for regulatory domains for many countries
and regulatory domains are now queried through a userspace agent
through udev allowing distributions to update regulatory rules
without updating the kernel.

Each driver can regulatory_hint() a regulatory domain
based on either their EEPROM mapped regulatory domain value to a
respective ISO/IEC 3166-1 country code or pass an internally built
regulatory domain. We also add support to let the user set the
regulatory domain through userspace in case of faulty EEPROMs to
further help compliance.

Support for world roaming will be added soon for cards capable of
this.

For more information see:

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

For now we leave an option to enable the old module parameter,
ieee80211_regdom, and to build the 3 old regdomains statically
(US, JP and EU). This option is CONFIG_WIRELESS_OLD_REGULATORY.
These old static definitions and the module parameter is being
scheduled for removal for 2.6.29. Note that if you use this
you won't make use of a world regulatory domain as its pointless.
If you leave this option enabled and if CRDA is present and you
use US or JP we will try to ask CRDA to update us a regulatory
domain for us.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 160 insertions, 2 deletions

diff --git a/net/wireless/core.c b/net/wireless/core.c
index 7e995ac06a0c..a910cd2d0fd1 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -13,12 +13,14 @@
 #include <linux/debugfs.h>
 #include <linux/notifier.h>
 #include <linux/device.h>
+#include <linux/list.h>
 #include <net/genetlink.h>
 #include <net/cfg80211.h>
 #include <net/wireless.h>
 #include "nl80211.h"
 #include "core.h"
 #include "sysfs.h"
+#include "reg.h"
 
 /* name for sysfs, %d is appended */
 #define PHY_NAME "phy"
@@ -27,6 +29,107 @@ MODULE_AUTHOR("Johannes Berg");
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("wireless configuration support");
 
+struct list_head regulatory_requests;
+
+/* Central wireless core regulatory domains, we only need two,
+ * the current one and a world regulatory domain in case we have no
+ * information to give us an alpha2 */
+struct ieee80211_regdomain *cfg80211_regdomain;
+
+/* We keep a static world regulatory domain in case of the absence of CRDA */
+const struct ieee80211_regdomain world_regdom = {
+        .n_reg_rules = 1,
+        .alpha2 =  "00",
+        .reg_rules = {
+                REG_RULE(2402, 2472, 40, 6, 20,
+                        NL80211_RRF_PASSIVE_SCAN |
+                        NL80211_RRF_NO_IBSS),
+        }
+};
+
+#ifdef CONFIG_WIRELESS_OLD_REGULATORY
+/* All this fucking static junk will be removed soon, so
+ * don't fucking count on it !@#$ */
+
+static char *ieee80211_regdom = "US";
+module_param(ieee80211_regdom, charp, 0444);
+MODULE_PARM_DESC(ieee80211_regdom, "IEEE 802.11 regulatory domain code");
+
+/* We assume 40 MHz bandwidth for the old regulatory work.
+ * We make emphasis we are using the exact same frequencies
+ * as before */
+
+const struct ieee80211_regdomain us_regdom = {
+        .n_reg_rules = 6,
+        .alpha2 =  "US",
+        .reg_rules = {
+                /* IEEE 802.11b/g, channels 1..11 */
+                REG_RULE(2412-20, 2462+20, 40, 6, 27, 0),
+                /* IEEE 802.11a, channel 36 */
+                REG_RULE(5180-20, 5180+20, 40, 6, 23, 0),
+                /* IEEE 802.11a, channel 40 */
+                REG_RULE(5200-20, 5200+20, 40, 6, 23, 0),
+                /* IEEE 802.11a, channel 44 */
+                REG_RULE(5220-20, 5220+20, 40, 6, 23, 0),
+                /* IEEE 802.11a, channels 48..64 */
+                REG_RULE(5240-20, 5320+20, 40, 6, 23, 0),
+                /* IEEE 802.11a, channels 149..165, outdoor */
+                REG_RULE(5745-20, 5825+20, 40, 6, 30, 0),
+        }
+};
+
+const struct ieee80211_regdomain jp_regdom = {
+        .n_reg_rules = 3,
+        .alpha2 =  "JP",
+        .reg_rules = {
+                /* IEEE 802.11b/g, channels 1..14 */
+                REG_RULE(2412-20, 2484+20, 40, 6, 20, 0),
+                /* IEEE 802.11a, channels 34..48 */
+                REG_RULE(5170-20, 5240+20, 40, 6, 20,
+                        NL80211_RRF_PASSIVE_SCAN),
+                /* IEEE 802.11a, channels 52..64 */
+                REG_RULE(5260-20, 5320+20, 40, 6, 20,
+                        NL80211_RRF_NO_IBSS |
+                        NL80211_RRF_DFS),
+        }
+};
+
+const struct ieee80211_regdomain eu_regdom = {
+        .n_reg_rules = 6,
+        /* This alpha2 is bogus, we leave it here just for stupid
+         * backward compatibility */
+        .alpha2 =  "EU",
+        .reg_rules = {
+                /* IEEE 802.11b/g, channels 1..13 */
+                REG_RULE(2412-20, 2472+20, 40, 6, 20, 0),
+                /* IEEE 802.11a, channel 36 */
+                REG_RULE(5180-20, 5180+20, 40, 6, 23,
+                        NL80211_RRF_PASSIVE_SCAN),
+                /* IEEE 802.11a, channel 40 */
+                REG_RULE(5200-20, 5200+20, 40, 6, 23,
+                        NL80211_RRF_PASSIVE_SCAN),
+                /* IEEE 802.11a, channel 44 */
+                REG_RULE(5220-20, 5220+20, 40, 6, 23,
+                        NL80211_RRF_PASSIVE_SCAN),
+                /* IEEE 802.11a, channels 48..64 */
+                REG_RULE(5240-20, 5320+20, 40, 6, 20,
+                        NL80211_RRF_NO_IBSS |
+                        NL80211_RRF_DFS),
+                /* IEEE 802.11a, channels 100..140 */
+                REG_RULE(5500-20, 5700+20, 40, 6, 30,
+                        NL80211_RRF_NO_IBSS |
+                        NL80211_RRF_DFS),
+        }
+};
+
+#endif
+
+struct ieee80211_regdomain *cfg80211_world_regdom =
+        (struct ieee80211_regdomain *) &world_regdom;
+
+LIST_HEAD(regulatory_requests);
+DEFINE_MUTEX(cfg80211_reg_mutex);
+
 /* RCU might be appropriate here since we usually
  * only read the list, and that can happen quite
  * often because we need to do it for each command */
@@ -302,7 +405,9 @@ int wiphy_register(struct wiphy *wiphy)
         ieee80211_set_bitrate_flags(wiphy);
 
         /* set up regulatory info */
-        wiphy_update_regulatory(wiphy);
+        mutex_lock(&cfg80211_reg_mutex);
+        wiphy_update_regulatory(wiphy, REGDOM_SET_BY_CORE);
+        mutex_unlock(&cfg80211_reg_mutex);
 
         mutex_lock(&cfg80211_drv_mutex);
 
@@ -409,9 +514,35 @@ static struct notifier_block cfg80211_netdev_notifier = {
         .notifier_call = cfg80211_netdev_notifier_call,
 };
 
+#ifdef CONFIG_WIRELESS_OLD_REGULATORY
+const struct ieee80211_regdomain *static_regdom(char *alpha2)
+{
+        if (alpha2[0] == 'U' && alpha2[1] == 'S')
+                return &us_regdom;
+        if (alpha2[0] == 'J' && alpha2[1] == 'P')
+                return &jp_regdom;
+        if (alpha2[0] == 'E' && alpha2[1] == 'U')
+                return &eu_regdom;
+        /* Default, as per the old rules */
+        return &us_regdom;
+}
+#endif
+
 static int cfg80211_init(void)
 {
-        int err = wiphy_sysfs_init();
+        int err;
+
+#ifdef CONFIG_WIRELESS_OLD_REGULATORY
+        cfg80211_regdomain =
+                (struct ieee80211_regdomain *) static_regdom(ieee80211_regdom);
+        /* Used during reset_regdomains_static() */
+        cfg80211_world_regdom = cfg80211_regdomain;
+#else
+        cfg80211_regdomain =
+                (struct ieee80211_regdomain *) cfg80211_world_regdom;
+#endif
+
+        err = wiphy_sysfs_init();
         if (err)
                 goto out_fail_sysfs;
 
@@ -425,8 +556,33 @@ static int cfg80211_init(void)
 
         ieee80211_debugfs_dir = debugfs_create_dir("ieee80211", NULL);
 
+        err = regulatory_init();
+        if (err)
+                goto out_fail_reg;
+
+#ifdef CONFIG_WIRELESS_OLD_REGULATORY
+        printk(KERN_INFO "cfg80211: Using old static regulatory domain:\n");
+        print_regdomain_info(cfg80211_regdomain);
+        /* The old code still requests for a new regdomain and if
+         * you have CRDA you get it updated, otherwise you get
+         * stuck with the static values. We ignore "EU" code as
+         * that is not a valid ISO / IEC 3166 alpha2 */
+        if (ieee80211_regdom[0] != 'E' &&
+                        ieee80211_regdom[1] != 'U')
+                err = __regulatory_hint(NULL, REGDOM_SET_BY_CORE,
+                        ieee80211_regdom, NULL);
+#else
+        err = __regulatory_hint(NULL, REGDOM_SET_BY_CORE, "00", NULL);
+        if (err)
+                printk(KERN_ERR "cfg80211: calling CRDA failed - "
+                        "unable to update world regulatory domain, "
+                        "using static definition\n");
+#endif
+
         return 0;
 
+out_fail_reg:
+        debugfs_remove(ieee80211_debugfs_dir);
 out_fail_nl80211:
         unregister_netdevice_notifier(&cfg80211_netdev_notifier);
 out_fail_notifier:
@@ -434,6 +590,7 @@ out_fail_notifier:
 out_fail_sysfs:
         return err;
 }
+
 subsys_initcall(cfg80211_init);
 
 static void cfg80211_exit(void)
@@ -442,5 +599,6 @@ static void cfg80211_exit(void)
         nl80211_exit();
         unregister_netdevice_notifier(&cfg80211_netdev_notifier);
         wiphy_sysfs_exit();
+        regulatory_exit();
 }
 module_exit(cfg80211_exit);