cfg80211/mac80211: Add 802.11d support
This adds country IE parsing to mac80211 and enables its usage
within the new regulatory infrastructure in cfg80211. We parse
the country IEs only on management beacons for the BSSID you are
associated to and disregard the IEs when the country and environment
(indoor, outdoor, any) matches the already processed country IE.
To avoid following misinformed or outdated APs we build and use
a regulatory domain out of the intersection between what the AP
provides us on the country IE and what CRDA is aware is allowed
on the same country.
A secondary device is allowed to follow only the same country IE
as it make no sense for two devices on a system to be in two
different countries.
In the case the AP is using country IEs for an incorrect country
the user may help compliance further by setting the regulatory
domain before or after the IE is parsed and in that case another
intersection will be performed.
CONFIG_WIRELESS_OLD_REGULATORY is supported but requires CRDA
present.
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index f0ff3d1..4dab993 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -60,12 +60,18 @@
* @intersect: indicates whether the wireless core should intersect
* the requested regulatory domain with the presently set regulatory
* domain.
+ * @country_ie_checksum: checksum of the last processed and accepted
+ * country IE
+ * @country_ie_env: lets us know if the AP is telling us we are outdoor,
+ * indoor, or if it doesn't matter
*/
struct regulatory_request {
struct wiphy *wiphy;
enum reg_set_by initiator;
char alpha2[2];
bool intersect;
+ u32 country_ie_checksum;
+ enum environment_cap country_ie_env;
};
/* Receipt of information from last regulatory request */
@@ -85,6 +91,11 @@
* information to give us an alpha2 */
static const struct ieee80211_regdomain *cfg80211_regdomain;
+/* We use this as a place for the rd structure built from the
+ * last parsed country IE to rest until CRDA gets back to us with
+ * what it thinks should apply for the same country */
+static const struct ieee80211_regdomain *country_ie_regdomain;
+
/* We keep a static world regulatory domain in case of the absence of CRDA */
static const struct ieee80211_regdomain world_regdom = {
.n_reg_rules = 1,
@@ -264,6 +275,18 @@
return false;
}
+static bool is_intersected_alpha2(const char *alpha2)
+{
+ if (!alpha2)
+ return false;
+ /* Special case where regulatory domain is the
+ * result of an intersection between two regulatory domain
+ * structures */
+ if (alpha2[0] == '9' && alpha2[1] == '8')
+ return true;
+ return false;
+}
+
static bool is_an_alpha2(const char *alpha2)
{
if (!alpha2)
@@ -292,6 +315,25 @@
return true;
}
+/**
+ * country_ie_integrity_changes - tells us if the country IE has changed
+ * @checksum: checksum of country IE of fields we are interested in
+ *
+ * If the country IE has not changed you can ignore it safely. This is
+ * useful to determine if two devices are seeing two different country IEs
+ * even on the same alpha2. Note that this will return false if no IE has
+ * been set on the wireless core yet.
+ */
+static bool country_ie_integrity_changes(u32 checksum)
+{
+ /* If no IE has been set then the checksum doesn't change */
+ if (unlikely(!last_request->country_ie_checksum))
+ return false;
+ if (unlikely(last_request->country_ie_checksum != checksum))
+ return true;
+ return false;
+}
+
/* This lets us keep regulatory code which is updated on a regulatory
* basis in userspace. */
static int call_crda(const char *alpha2)
@@ -379,6 +421,174 @@
return 0;
}
+/* Converts a country IE to a regulatory domain. A regulatory domain
+ * structure has a lot of information which the IE doesn't yet have,
+ * so for the other values we use upper max values as we will intersect
+ * with our userspace regulatory agent to get lower bounds. */
+static struct ieee80211_regdomain *country_ie_2_rd(
+ u8 *country_ie,
+ u8 country_ie_len,
+ u32 *checksum)
+{
+ struct ieee80211_regdomain *rd = NULL;
+ unsigned int i = 0;
+ char alpha2[2];
+ u32 flags = 0;
+ u32 num_rules = 0, size_of_regd = 0;
+ u8 *triplets_start = NULL;
+ u8 len_at_triplet = 0;
+ /* the last channel we have registered in a subband (triplet) */
+ int last_sub_max_channel = 0;
+
+ *checksum = 0xDEADBEEF;
+
+ /* Country IE requirements */
+ BUG_ON(country_ie_len < IEEE80211_COUNTRY_IE_MIN_LEN ||
+ country_ie_len & 0x01);
+
+ alpha2[0] = country_ie[0];
+ alpha2[1] = country_ie[1];
+
+ /*
+ * Third octet can be:
+ * 'I' - Indoor
+ * 'O' - Outdoor
+ *
+ * anything else we assume is no restrictions
+ */
+ if (country_ie[2] == 'I')
+ flags = NL80211_RRF_NO_OUTDOOR;
+ else if (country_ie[2] == 'O')
+ flags = NL80211_RRF_NO_INDOOR;
+
+ country_ie += 3;
+ country_ie_len -= 3;
+
+ triplets_start = country_ie;
+ len_at_triplet = country_ie_len;
+
+ *checksum ^= ((flags ^ alpha2[0] ^ alpha2[1]) << 8);
+
+ /* We need to build a reg rule for each triplet, but first we must
+ * calculate the number of reg rules we will need. We will need one
+ * for each channel subband */
+ while (country_ie_len >= 3) {
+ struct ieee80211_country_ie_triplet *triplet =
+ (struct ieee80211_country_ie_triplet *) country_ie;
+ int cur_sub_max_channel = 0, cur_channel = 0;
+
+ if (triplet->ext.reg_extension_id >=
+ IEEE80211_COUNTRY_EXTENSION_ID) {
+ country_ie += 3;
+ country_ie_len -= 3;
+ continue;
+ }
+
+ cur_channel = triplet->chans.first_channel;
+ cur_sub_max_channel = ieee80211_channel_to_frequency(
+ cur_channel + triplet->chans.num_channels);
+
+ /* Basic sanity check */
+ if (cur_sub_max_channel < cur_channel)
+ return NULL;
+
+ /* Do not allow overlapping channels. Also channels
+ * passed in each subband must be monotonically
+ * increasing */
+ if (last_sub_max_channel) {
+ if (cur_channel <= last_sub_max_channel)
+ return NULL;
+ if (cur_sub_max_channel <= last_sub_max_channel)
+ return NULL;
+ }
+
+ /* When dot11RegulatoryClassesRequired is supported
+ * we can throw ext triplets as part of this soup,
+ * for now we don't care when those change as we
+ * don't support them */
+ *checksum ^= ((cur_channel ^ cur_sub_max_channel) << 8) |
+ ((cur_sub_max_channel ^ cur_sub_max_channel) << 16) |
+ ((triplet->chans.max_power ^ cur_sub_max_channel) << 24);
+
+ last_sub_max_channel = cur_sub_max_channel;
+
+ country_ie += 3;
+ country_ie_len -= 3;
+ num_rules++;
+
+ /* Note: this is not a IEEE requirement but
+ * simply a memory requirement */
+ if (num_rules > NL80211_MAX_SUPP_REG_RULES)
+ return NULL;
+ }
+
+ country_ie = triplets_start;
+ country_ie_len = len_at_triplet;
+
+ size_of_regd = sizeof(struct ieee80211_regdomain) +
+ (num_rules * sizeof(struct ieee80211_reg_rule));
+
+ rd = kzalloc(size_of_regd, GFP_KERNEL);
+ if (!rd)
+ return NULL;
+
+ rd->n_reg_rules = num_rules;
+ rd->alpha2[0] = alpha2[0];
+ rd->alpha2[1] = alpha2[1];
+
+ /* This time around we fill in the rd */
+ while (country_ie_len >= 3) {
+ struct ieee80211_country_ie_triplet *triplet =
+ (struct ieee80211_country_ie_triplet *) country_ie;
+ struct ieee80211_reg_rule *reg_rule = NULL;
+ struct ieee80211_freq_range *freq_range = NULL;
+ struct ieee80211_power_rule *power_rule = NULL;
+
+ /* Must parse if dot11RegulatoryClassesRequired is true,
+ * we don't support this yet */
+ if (triplet->ext.reg_extension_id >=
+ IEEE80211_COUNTRY_EXTENSION_ID) {
+ country_ie += 3;
+ country_ie_len -= 3;
+ continue;
+ }
+
+ reg_rule = &rd->reg_rules[i];
+ freq_range = ®_rule->freq_range;
+ power_rule = ®_rule->power_rule;
+
+ reg_rule->flags = flags;
+
+ /* The +10 is since the regulatory domain expects
+ * the actual band edge, not the center of freq for
+ * its start and end freqs, assuming 20 MHz bandwidth on
+ * the channels passed */
+ freq_range->start_freq_khz =
+ MHZ_TO_KHZ(ieee80211_channel_to_frequency(
+ triplet->chans.first_channel) - 10);
+ freq_range->end_freq_khz =
+ MHZ_TO_KHZ(ieee80211_channel_to_frequency(
+ triplet->chans.first_channel +
+ triplet->chans.num_channels) + 10);
+
+ /* Large arbitrary values, we intersect later */
+ /* Increment this if we ever support >= 40 MHz channels
+ * in IEEE 802.11 */
+ freq_range->max_bandwidth_khz = MHZ_TO_KHZ(40);
+ power_rule->max_antenna_gain = DBI_TO_MBI(100);
+ power_rule->max_eirp = DBM_TO_MBM(100);
+
+ country_ie += 3;
+ country_ie_len -= 3;
+ i++;
+
+ BUG_ON(i > NL80211_MAX_SUPP_REG_RULES);
+ }
+
+ return rd;
+}
+
+
/* Helper for regdom_intersect(), this does the real
* mathematical intersection fun */
static int reg_rules_intersect(
@@ -663,16 +873,14 @@
return -EOPNOTSUPP;
return -EALREADY;
}
- /* Two consecutive Country IE hints on the same wiphy */
- if (!alpha2_equal(cfg80211_regdomain->alpha2, alpha2))
+ /* Two consecutive Country IE hints on the same wiphy.
+ * This should be picked up early by the driver/stack */
+ if (WARN_ON(!alpha2_equal(cfg80211_regdomain->alpha2,
+ alpha2)))
return 0;
return -EALREADY;
}
- /*
- * Ignore Country IE hints for now, need to think about
- * what we need to do to support multi-domain operation.
- */
- return -EOPNOTSUPP;
+ return REG_INTERSECT;
case REGDOM_SET_BY_DRIVER:
if (last_request->initiator == REGDOM_SET_BY_DRIVER)
return -EALREADY;
@@ -680,6 +888,11 @@
case REGDOM_SET_BY_USER:
if (last_request->initiator == REGDOM_SET_BY_COUNTRY_IE)
return REG_INTERSECT;
+ /* If the user knows better the user should set the regdom
+ * to their country before the IE is picked up */
+ if (last_request->initiator == REGDOM_SET_BY_USER &&
+ last_request->intersect)
+ return -EOPNOTSUPP;
return 0;
}
@@ -688,7 +901,9 @@
/* Caller must hold &cfg80211_drv_mutex */
int __regulatory_hint(struct wiphy *wiphy, enum reg_set_by set_by,
- const char *alpha2)
+ const char *alpha2,
+ u32 country_ie_checksum,
+ enum environment_cap env)
{
struct regulatory_request *request;
bool intersect = false;
@@ -711,9 +926,21 @@
request->initiator = set_by;
request->wiphy = wiphy;
request->intersect = intersect;
+ request->country_ie_checksum = country_ie_checksum;
+ request->country_ie_env = env;
kfree(last_request);
last_request = request;
+ /*
+ * Note: When CONFIG_WIRELESS_OLD_REGULATORY is enabled
+ * AND if CRDA is NOT present nothing will happen, if someone
+ * wants to bother with 11d with OLD_REG you can add a timer.
+ * If after x amount of time nothing happens you can call:
+ *
+ * return set_regdom(country_ie_regdomain);
+ *
+ * to intersect with the static rd
+ */
return call_crda(alpha2);
}
@@ -722,11 +949,120 @@
BUG_ON(!alpha2);
mutex_lock(&cfg80211_drv_mutex);
- __regulatory_hint(wiphy, REGDOM_SET_BY_DRIVER, alpha2);
+ __regulatory_hint(wiphy, REGDOM_SET_BY_DRIVER, alpha2, 0, ENVIRON_ANY);
mutex_unlock(&cfg80211_drv_mutex);
}
EXPORT_SYMBOL(regulatory_hint);
+static bool reg_same_country_ie_hint(struct wiphy *wiphy,
+ u32 country_ie_checksum)
+{
+ if (!last_request->wiphy)
+ return false;
+ if (likely(last_request->wiphy != wiphy))
+ return !country_ie_integrity_changes(country_ie_checksum);
+ /* We should not have let these through at this point, they
+ * should have been picked up earlier by the first alpha2 check
+ * on the device */
+ if (WARN_ON(!country_ie_integrity_changes(country_ie_checksum)))
+ return true;
+ return false;
+}
+
+void regulatory_hint_11d(struct wiphy *wiphy,
+ u8 *country_ie,
+ u8 country_ie_len)
+{
+ struct ieee80211_regdomain *rd = NULL;
+ char alpha2[2];
+ u32 checksum = 0;
+ enum environment_cap env = ENVIRON_ANY;
+
+ mutex_lock(&cfg80211_drv_mutex);
+
+ /* IE len must be evenly divisible by 2 */
+ if (country_ie_len & 0x01)
+ goto out;
+
+ if (country_ie_len < IEEE80211_COUNTRY_IE_MIN_LEN)
+ goto out;
+
+ /* Pending country IE processing, this can happen after we
+ * call CRDA and wait for a response if a beacon was received before
+ * we were able to process the last regulatory_hint_11d() call */
+ if (country_ie_regdomain)
+ goto out;
+
+ alpha2[0] = country_ie[0];
+ alpha2[1] = country_ie[1];
+
+ if (country_ie[2] == 'I')
+ env = ENVIRON_INDOOR;
+ else if (country_ie[2] == 'O')
+ env = ENVIRON_OUTDOOR;
+
+ /* We will run this for *every* beacon processed for the BSSID, so
+ * we optimize an early check to exit out early if we don't have to
+ * do anything */
+ if (likely(last_request->wiphy)) {
+ struct cfg80211_registered_device *drv_last_ie;
+
+ drv_last_ie = wiphy_to_dev(last_request->wiphy);
+
+ /* Lets keep this simple -- we trust the first AP
+ * after we intersect with CRDA */
+ if (likely(last_request->wiphy == wiphy)) {
+ /* Ignore IEs coming in on this wiphy with
+ * the same alpha2 and environment cap */
+ if (likely(alpha2_equal(drv_last_ie->country_ie_alpha2,
+ alpha2) &&
+ env == drv_last_ie->env)) {
+ goto out;
+ }
+ /* the wiphy moved on to another BSSID or the AP
+ * was reconfigured. XXX: We need to deal with the
+ * case where the user suspends and goes to goes
+ * to another country, and then gets IEs from an
+ * AP with different settings */
+ goto out;
+ } else {
+ /* Ignore IEs coming in on two separate wiphys with
+ * the same alpha2 and environment cap */
+ if (likely(alpha2_equal(drv_last_ie->country_ie_alpha2,
+ alpha2) &&
+ env == drv_last_ie->env)) {
+ goto out;
+ }
+ /* We could potentially intersect though */
+ goto out;
+ }
+ }
+
+ rd = country_ie_2_rd(country_ie, country_ie_len, &checksum);
+ if (!rd)
+ goto out;
+
+ /* This will not happen right now but we leave it here for the
+ * the future when we want to add suspend/resume support and having
+ * the user move to another country after doing so, or having the user
+ * move to another AP. Right now we just trust the first AP. This is why
+ * this is marked as likley(). If we hit this before we add this support
+ * we want to be informed of it as it would indicate a mistake in the
+ * current design */
+ if (likely(WARN_ON(reg_same_country_ie_hint(wiphy, checksum))))
+ goto out;
+
+ /* We keep this around for when CRDA comes back with a response so
+ * we can intersect with that */
+ country_ie_regdomain = rd;
+
+ __regulatory_hint(wiphy, REGDOM_SET_BY_COUNTRY_IE,
+ country_ie_regdomain->alpha2, checksum, env);
+
+out:
+ mutex_unlock(&cfg80211_drv_mutex);
+}
+EXPORT_SYMBOL(regulatory_hint_11d);
static void print_rd_rules(const struct ieee80211_regdomain *rd)
{
@@ -766,7 +1102,25 @@
static void print_regdomain(const struct ieee80211_regdomain *rd)
{
- if (is_world_regdom(rd->alpha2))
+ if (is_intersected_alpha2(rd->alpha2)) {
+ struct wiphy *wiphy = NULL;
+ struct cfg80211_registered_device *drv;
+
+ if (last_request->initiator == REGDOM_SET_BY_COUNTRY_IE) {
+ if (last_request->wiphy) {
+ wiphy = last_request->wiphy;
+ drv = wiphy_to_dev(wiphy);
+ printk(KERN_INFO "cfg80211: Current regulatory "
+ "domain updated by AP to: %c%c\n",
+ drv->country_ie_alpha2[0],
+ drv->country_ie_alpha2[1]);
+ } else
+ printk(KERN_INFO "cfg80211: Current regulatory "
+ "domain intersected: \n");
+ } else
+ printk(KERN_INFO "cfg80211: Current regulatory "
+ "intersected: \n");
+ } else if (is_world_regdom(rd->alpha2))
printk(KERN_INFO "cfg80211: World regulatory "
"domain updated:\n");
else {
@@ -789,10 +1143,39 @@
print_rd_rules(rd);
}
+#ifdef CONFIG_CFG80211_REG_DEBUG
+static void reg_country_ie_process_debug(
+ const struct ieee80211_regdomain *rd,
+ const struct ieee80211_regdomain *country_ie_regdomain,
+ const struct ieee80211_regdomain *intersected_rd)
+{
+ printk(KERN_DEBUG "cfg80211: Received country IE:\n");
+ print_regdomain_info(country_ie_regdomain);
+ printk(KERN_DEBUG "cfg80211: CRDA thinks this should applied:\n");
+ print_regdomain_info(rd);
+ if (intersected_rd) {
+ printk(KERN_DEBUG "cfg80211: We intersect both of these "
+ "and get:\n");
+ print_regdomain_info(rd);
+ return;
+ }
+ printk(KERN_DEBUG "cfg80211: Intersection between both failed\n");
+}
+#else
+static inline void reg_country_ie_process_debug(
+ const struct ieee80211_regdomain *rd,
+ const struct ieee80211_regdomain *country_ie_regdomain,
+ const struct ieee80211_regdomain *intersected_rd)
+{
+}
+#endif
+
/* Takes ownership of rd only if it doesn't fail */
static int __set_regdom(const struct ieee80211_regdomain *rd)
{
const struct ieee80211_regdomain *intersected_rd = NULL;
+ struct cfg80211_registered_device *drv = NULL;
+ struct wiphy *wiphy = NULL;
/* Some basic sanity checks first */
if (is_world_regdom(rd->alpha2)) {
@@ -809,10 +1192,18 @@
if (!last_request)
return -EINVAL;
- /* allow overriding the static definitions if CRDA is present */
- if (!is_old_static_regdom(cfg80211_regdomain) &&
- !regdom_changed(rd->alpha2))
- return -EINVAL;
+ /* Lets only bother proceeding on the same alpha2 if the current
+ * rd is non static (it means CRDA was present and was used last)
+ * and the pending request came in from a country IE */
+ if (last_request->initiator != REGDOM_SET_BY_COUNTRY_IE) {
+ /* If someone else asked us to change the rd lets only bother
+ * checking if the alpha2 changes if CRDA was already called */
+ if (!is_old_static_regdom(cfg80211_regdomain) &&
+ !regdom_changed(rd->alpha2))
+ return -EINVAL;
+ }
+
+ wiphy = last_request->wiphy;
/* Now lets set the regulatory domain, update all driver channels
* and finally inform them of what we have done, in case they want
@@ -853,9 +1244,47 @@
return 0;
}
- /* Country IE parsing coming soon */
+ /*
+ * Country IE requests are handled a bit differently, we intersect
+ * the country IE rd with what CRDA believes that country should have
+ */
+
+ BUG_ON(!country_ie_regdomain);
+
+ if (rd != country_ie_regdomain) {
+ /* Intersect what CRDA returned and our what we
+ * had built from the Country IE received */
+
+ intersected_rd = regdom_intersect(rd, country_ie_regdomain);
+
+ reg_country_ie_process_debug(rd, country_ie_regdomain,
+ intersected_rd);
+
+ kfree(country_ie_regdomain);
+ country_ie_regdomain = NULL;
+ } else {
+ /* This would happen when CRDA was not present and
+ * OLD_REGULATORY was enabled. We intersect our Country
+ * IE rd and what was set on cfg80211 originally */
+ intersected_rd = regdom_intersect(rd, cfg80211_regdomain);
+ }
+
+ if (!intersected_rd)
+ return -EINVAL;
+
+ drv = wiphy_to_dev(wiphy);
+
+ drv->country_ie_alpha2[0] = rd->alpha2[0];
+ drv->country_ie_alpha2[1] = rd->alpha2[1];
+ drv->env = last_request->country_ie_env;
+
+ BUG_ON(intersected_rd == rd);
+
+ kfree(rd);
+ rd = NULL;
+
reset_regdomains();
- WARN_ON(1);
+ cfg80211_regdomain = intersected_rd;
return 0;
}
@@ -887,6 +1316,17 @@
return r;
}
+/* Caller must hold cfg80211_drv_mutex */
+void reg_device_remove(struct wiphy *wiphy)
+{
+ if (!last_request->wiphy)
+ return;
+ if (last_request->wiphy != wiphy)
+ return;
+ last_request->wiphy = NULL;
+ last_request->country_ie_env = ENVIRON_ANY;
+}
+
int regulatory_init(void)
{
int err;
@@ -906,11 +1346,11 @@
* 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);
+ ieee80211_regdom, 0, ENVIRON_ANY);
#else
cfg80211_regdomain = cfg80211_world_regdom;
- err = __regulatory_hint(NULL, REGDOM_SET_BY_CORE, "00");
+ err = __regulatory_hint(NULL, REGDOM_SET_BY_CORE, "00", 0, ENVIRON_ANY);
if (err)
printk(KERN_ERR "cfg80211: calling CRDA failed - "
"unable to update world regulatory domain, "
@@ -926,6 +1366,9 @@
reset_regdomains();
+ kfree(country_ie_regdomain);
+ country_ie_regdomain = NULL;
+
kfree(last_request);
platform_device_unregister(reg_pdev);