wireless: only use alpha2 regulatory information from country IE
[linux-2.6.git] / net / wireless / reg.c
index 1ac2bdd..678d0bd 100644 (file)
@@ -67,17 +67,9 @@ static struct platform_device *reg_pdev;
 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;
-
-/*
  * Protects static reg.c components:
  *     - cfg80211_world_regdom
  *     - cfg80211_regdom
- *     - country_ie_regdomain
  *     - last_request
  */
 static DEFINE_MUTEX(reg_mutex);
@@ -275,25 +267,6 @@ static bool is_user_regdom_saved(void)
        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;
-}
-
 static int reg_copy_regd(const struct ieee80211_regdomain **dst_regd,
                         const struct ieee80211_regdomain *src_regd)
 {
@@ -506,471 +479,6 @@ static bool freq_in_rule_band(const struct ieee80211_freq_range *freq_range,
 }
 
 /*
- * This is a work around for sanity checking ieee80211_channel_to_frequency()'s
- * work. ieee80211_channel_to_frequency() can for example currently provide a
- * 2 GHz channel when in fact a 5 GHz channel was desired. An example would be
- * an AP providing channel 8 on a country IE triplet when it sent this on the
- * 5 GHz band, that channel is designed to be channel 8 on 5 GHz, not a 2 GHz
- * channel.
- *
- * This can be removed once ieee80211_channel_to_frequency() takes in a band.
- */
-static bool chan_in_band(int chan, enum ieee80211_band band)
-{
-       int center_freq = ieee80211_channel_to_frequency(chan);
-
-       switch (band) {
-       case IEEE80211_BAND_2GHZ:
-               if (center_freq <= 2484)
-                       return true;
-               return false;
-       case IEEE80211_BAND_5GHZ:
-               if (center_freq >= 5005)
-                       return true;
-               return false;
-       default:
-               return false;
-       }
-}
-
-/*
- * Some APs may send a country IE triplet for each channel they
- * support and while this is completely overkill and silly we still
- * need to support it. We avoid making a single rule for each channel
- * though and to help us with this we use this helper to find the
- * actual subband end channel. These type of country IE triplet
- * scenerios are handled then, all yielding two regulaotry rules from
- * parsing a country IE:
- *
- * [1]
- * [2]
- * [36]
- * [40]
- *
- * [1]
- * [2-4]
- * [5-12]
- * [36]
- * [40-44]
- *
- * [1-4]
- * [5-7]
- * [36-44]
- * [48-64]
- *
- * [36-36]
- * [40-40]
- * [44-44]
- * [48-48]
- * [52-52]
- * [56-56]
- * [60-60]
- * [64-64]
- * [100-100]
- * [104-104]
- * [108-108]
- * [112-112]
- * [116-116]
- * [120-120]
- * [124-124]
- * [128-128]
- * [132-132]
- * [136-136]
- * [140-140]
- *
- * Returns 0 if the IE has been found to be invalid in the middle
- * somewhere.
- */
-static int max_subband_chan(enum ieee80211_band band,
-                           int orig_cur_chan,
-                           int orig_end_channel,
-                           s8 orig_max_power,
-                           u8 **country_ie,
-                           u8 *country_ie_len)
-{
-       u8 *triplets_start = *country_ie;
-       u8 len_at_triplet = *country_ie_len;
-       int end_subband_chan = orig_end_channel;
-
-       /*
-        * We'll deal with padding for the caller unless
-        * its not immediate and we don't process any channels
-        */
-       if (*country_ie_len == 1) {
-               *country_ie += 1;
-               *country_ie_len -= 1;
-               return orig_end_channel;
-       }
-
-       /* Move to the next triplet and then start search */
-       *country_ie += 3;
-       *country_ie_len -= 3;
-
-       if (!chan_in_band(orig_cur_chan, band))
-               return 0;
-
-       while (*country_ie_len >= 3) {
-               int end_channel = 0;
-               struct ieee80211_country_ie_triplet *triplet =
-                       (struct ieee80211_country_ie_triplet *) *country_ie;
-               int cur_channel = 0, next_expected_chan;
-
-               /* means last triplet is completely unrelated to this one */
-               if (triplet->ext.reg_extension_id >=
-                               IEEE80211_COUNTRY_EXTENSION_ID) {
-                       *country_ie -= 3;
-                       *country_ie_len += 3;
-                       break;
-               }
-
-               if (triplet->chans.first_channel == 0) {
-                       *country_ie += 1;
-                       *country_ie_len -= 1;
-                       if (*country_ie_len != 0)
-                               return 0;
-                       break;
-               }
-
-               if (triplet->chans.num_channels == 0)
-                       return 0;
-
-               /* Monitonically increasing channel order */
-               if (triplet->chans.first_channel <= end_subband_chan)
-                       return 0;
-
-               if (!chan_in_band(triplet->chans.first_channel, band))
-                       return 0;
-
-               /* 2 GHz */
-               if (triplet->chans.first_channel <= 14) {
-                       end_channel = triplet->chans.first_channel +
-                               triplet->chans.num_channels - 1;
-               }
-               else {
-                       end_channel =  triplet->chans.first_channel +
-                               (4 * (triplet->chans.num_channels - 1));
-               }
-
-               if (!chan_in_band(end_channel, band))
-                       return 0;
-
-               if (orig_max_power != triplet->chans.max_power) {
-                       *country_ie -= 3;
-                       *country_ie_len += 3;
-                       break;
-               }
-
-               cur_channel = triplet->chans.first_channel;
-
-               /* The key is finding the right next expected channel */
-               if (band == IEEE80211_BAND_2GHZ)
-                       next_expected_chan = end_subband_chan + 1;
-                else
-                       next_expected_chan = end_subband_chan + 4;
-
-               if (cur_channel != next_expected_chan) {
-                       *country_ie -= 3;
-                       *country_ie_len += 3;
-                       break;
-               }
-
-               end_subband_chan = end_channel;
-
-               /* Move to the next one */
-               *country_ie += 3;
-               *country_ie_len -= 3;
-
-               /*
-                * Padding needs to be dealt with if we processed
-                * some channels.
-                */
-               if (*country_ie_len == 1) {
-                       *country_ie += 1;
-                       *country_ie_len -= 1;
-                       break;
-               }
-
-               /* If seen, the IE is invalid */
-               if (*country_ie_len == 2)
-                       return 0;
-       }
-
-       if (end_subband_chan == orig_end_channel) {
-               *country_ie = triplets_start;
-               *country_ie_len = len_at_triplet;
-               return orig_end_channel;
-       }
-
-       return end_subband_chan;
-}
-
-/*
- * 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(
-                               enum ieee80211_band band,
-                               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) {
-               int end_channel = 0;
-               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;
-               }
-
-               /*
-                * APs can add padding to make length divisible
-                * by two, required by the spec.
-                */
-               if (triplet->chans.first_channel == 0) {
-                       country_ie++;
-                       country_ie_len--;
-                       /* This is expected to be at the very end only */
-                       if (country_ie_len != 0)
-                               return NULL;
-                       break;
-               }
-
-               if (triplet->chans.num_channels == 0)
-                       return NULL;
-
-               if (!chan_in_band(triplet->chans.first_channel, band))
-                       return NULL;
-
-               /* 2 GHz */
-               if (band == IEEE80211_BAND_2GHZ)
-                       end_channel = triplet->chans.first_channel +
-                               triplet->chans.num_channels - 1;
-               else
-                       /*
-                        * 5 GHz -- For example in country IEs if the first
-                        * channel given is 36 and the number of channels is 4
-                        * then the individual channel numbers defined for the
-                        * 5 GHz PHY by these parameters are: 36, 40, 44, and 48
-                        * and not 36, 37, 38, 39.
-                        *
-                        * See: http://tinyurl.com/11d-clarification
-                        */
-                       end_channel =  triplet->chans.first_channel +
-                               (4 * (triplet->chans.num_channels - 1));
-
-               cur_channel = triplet->chans.first_channel;
-
-               /*
-                * Enhancement for APs that send a triplet for every channel
-                * or for whatever reason sends triplets with multiple channels
-                * separated when in fact they should be together.
-                */
-               end_channel = max_subband_chan(band,
-                                              cur_channel,
-                                              end_channel,
-                                              triplet->chans.max_power,
-                                              &country_ie,
-                                              &country_ie_len);
-               if (!end_channel)
-                       return NULL;
-
-               if (!chan_in_band(end_channel, band))
-                       return NULL;
-
-               cur_sub_max_channel = end_channel;
-
-               /* 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;
-
-               num_rules++;
-
-               if (country_ie_len >= 3) {
-                       country_ie += 3;
-                       country_ie_len -= 3;
-               }
-
-               /*
-                * 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) {
-               int end_channel = 0;
-               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;
-               }
-
-               if (triplet->chans.first_channel == 0) {
-                       country_ie++;
-                       country_ie_len--;
-                       break;
-               }
-
-               reg_rule = &rd->reg_rules[i];
-               freq_range = &reg_rule->freq_range;
-               power_rule = &reg_rule->power_rule;
-
-               reg_rule->flags = flags;
-
-               /* 2 GHz */
-               if (band == IEEE80211_BAND_2GHZ)
-                       end_channel = triplet->chans.first_channel +
-                               triplet->chans.num_channels -1;
-               else
-                       end_channel =  triplet->chans.first_channel +
-                               (4 * (triplet->chans.num_channels - 1));
-
-               end_channel = max_subband_chan(band,
-                                              triplet->chans.first_channel,
-                                              end_channel,
-                                              triplet->chans.max_power,
-                                              &country_ie,
-                                              &country_ie_len);
-
-               /*
-                * 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(
-                               end_channel) + 10);
-
-               /*
-                * These are large arbitrary values we use to 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(triplet->chans.max_power);
-
-               i++;
-
-               if (country_ie_len >= 3) {
-                       country_ie += 3;
-                       country_ie_len -= 3;
-               }
-
-               BUG_ON(i > NL80211_MAX_SUPP_REG_RULES);
-       }
-
-       return rd;
-}
-
-
-/*
  * Helper for regdom_intersect(), this does the real
  * mathematical intersection fun
  */
@@ -1191,7 +699,6 @@ static int freq_reg_info_regd(struct wiphy *wiphy,
 
        return -EINVAL;
 }
-EXPORT_SYMBOL(freq_reg_info);
 
 int freq_reg_info(struct wiphy *wiphy,
                  u32 center_freq,
@@ -1205,6 +712,7 @@ int freq_reg_info(struct wiphy *wiphy,
                                  reg_rule,
                                  NULL);
 }
+EXPORT_SYMBOL(freq_reg_info);
 
 /*
  * Note that right now we assume the desired channel bandwidth
@@ -1243,41 +751,8 @@ static void handle_channel(struct wiphy *wiphy, enum ieee80211_band band,
                          desired_bw_khz,
                          &reg_rule);
 
-       if (r) {
-               /*
-                * This means no regulatory rule was found in the country IE
-                * with a frequency range on the center_freq's band, since
-                * IEEE-802.11 allows for a country IE to have a subset of the
-                * regulatory information provided in a country we ignore
-                * disabling the channel unless at least one reg rule was
-                * found on the center_freq's band. For details see this
-                * clarification:
-                *
-                * http://tinyurl.com/11d-clarification
-                */
-               if (r == -ERANGE &&
-                   last_request->initiator ==
-                   NL80211_REGDOM_SET_BY_COUNTRY_IE) {
-                       REG_DBG_PRINT("cfg80211: Leaving channel %d MHz "
-                               "intact on %s - no rule found in band on "
-                               "Country IE\n",
-                       chan->center_freq, wiphy_name(wiphy));
-               } else {
-               /*
-                * In this case we know the country IE has at least one reg rule
-                * for the band so we respect its band definitions
-                */
-                       if (last_request->initiator ==
-                           NL80211_REGDOM_SET_BY_COUNTRY_IE)
-                               REG_DBG_PRINT("cfg80211: Disabling "
-                                       "channel %d MHz on %s due to "
-                                       "Country IE\n",
-                                       chan->center_freq, wiphy_name(wiphy));
-                       flags |= IEEE80211_CHAN_DISABLED;
-                       chan->flags = flags;
-               }
+       if (r)
                return;
-       }
 
        power_rule = &reg_rule->power_rule;
        freq_range = &reg_rule->freq_range;
@@ -2010,7 +1485,7 @@ EXPORT_SYMBOL(regulatory_hint);
 
 /* Caller must hold reg_mutex */
 static bool reg_same_country_ie_hint(struct wiphy *wiphy,
-                       u32 country_ie_checksum)
+                       char *alpha2, enum environment_cap env)
 {
        struct wiphy *request_wiphy;
 
@@ -2026,13 +1501,17 @@ static bool reg_same_country_ie_hint(struct wiphy *wiphy,
                return false;
 
        if (likely(request_wiphy != wiphy))
-               return !country_ie_integrity_changes(country_ie_checksum);
+               return (last_request->alpha2[0] == alpha2[0] &&
+                       last_request->alpha2[1] == alpha2[1] &&
+                       last_request->country_ie_env == env);
        /*
         * 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)))
+       if (WARN_ON((last_request->alpha2[0] == alpha2[0] &&
+                       last_request->alpha2[1] == alpha2[1] &&
+                       last_request->country_ie_env == env )))
                return true;
        return false;
 }
@@ -2048,7 +1527,6 @@ void regulatory_hint_11d(struct wiphy *wiphy,
 {
        struct ieee80211_regdomain *rd = NULL;
        char alpha2[2];
-       u32 checksum = 0;
        enum environment_cap env = ENVIRON_ANY;
        struct regulatory_request *request;
 
@@ -2064,14 +1542,6 @@ void regulatory_hint_11d(struct wiphy *wiphy,
        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];
 
@@ -2090,12 +1560,6 @@ void regulatory_hint_11d(struct wiphy *wiphy,
            wiphy_idx_valid(last_request->wiphy_idx)))
                goto out;
 
-       rd = country_ie_2_rd(band, country_ie, country_ie_len, &checksum);
-       if (!rd) {
-               REG_DBG_PRINT("cfg80211: Ignoring bogus country IE\n");
-               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
@@ -2105,24 +1569,17 @@ void regulatory_hint_11d(struct wiphy *wiphy,
         * 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 (WARN_ON(reg_same_country_ie_hint(wiphy, checksum)))
+       if (WARN_ON(reg_same_country_ie_hint(wiphy, alpha2, env)))
                goto free_rd_out;
 
        request = kzalloc(sizeof(struct regulatory_request), GFP_KERNEL);
        if (!request)
                goto free_rd_out;
 
-       /*
-        * We keep this around for when CRDA comes back with a response so
-        * we can intersect with that
-        */
-       country_ie_regdomain = rd;
-
        request->wiphy_idx = get_wiphy_idx(wiphy);
-       request->alpha2[0] = rd->alpha2[0];
-       request->alpha2[1] = rd->alpha2[1];
+       request->alpha2[0] = alpha2[0];
+       request->alpha2[1] = alpha2[1];
        request->initiator = NL80211_REGDOM_SET_BY_COUNTRY_IE;
-       request->country_ie_checksum = checksum;
        request->country_ie_env = env;
 
        mutex_unlock(&reg_mutex);
@@ -2383,33 +1840,6 @@ static void print_regdomain_info(const struct ieee80211_regdomain *rd)
        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(intersected_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)
 {
@@ -2521,34 +1951,6 @@ static int __set_regdom(const struct ieee80211_regdomain *rd)
                return 0;
        }
 
-       /*
-        * Country IE requests are handled a bit differently, we intersect
-        * the country IE rd with what CRDA believes that country should have
-        */
-
-       /*
-        * Userspace could have sent two replies with only
-        * one kernel request. By the second reply we would have
-        * already processed and consumed the country_ie_regdomain.
-        */
-       if (!country_ie_regdomain)
-               return -EALREADY;
-       BUG_ON(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;
-
        if (!intersected_rd)
                return -EINVAL;
 
@@ -2688,9 +2090,6 @@ void /* __init_or_exit */ regulatory_exit(void)
 
        reset_regdomains();
 
-       kfree(country_ie_regdomain);
-       country_ie_regdomain = NULL;
-
        kfree(last_request);
 
        platform_device_unregister(reg_pdev);