diff options
Diffstat (limited to 'net/wireless/reg.c')
| -rw-r--r-- | net/wireless/reg.c | 480 |
1 files changed, 446 insertions, 34 deletions
diff --git a/net/wireless/reg.c b/net/wireless/reg.c index 87ea60d..ed89c59 100644 --- a/net/wireless/reg.c +++ b/net/wireless/reg.c @@ -43,6 +43,15 @@ #include "regdb.h" #include "nl80211.h" +#ifdef CONFIG_CFG80211_REG_DEBUG +#define REG_DBG_PRINT(format, args...) \ + do { \ + printk(KERN_DEBUG format , ## args); \ + } while (0) +#else +#define REG_DBG_PRINT(args...) +#endif + /* Receipt of information from last regulatory request */ static struct regulatory_request *last_request; @@ -125,6 +134,7 @@ static const struct ieee80211_regdomain *cfg80211_world_regdom = &world_regdom; static char *ieee80211_regdom = "00"; +static char user_alpha2[2]; module_param(ieee80211_regdom, charp, 0444); MODULE_PARM_DESC(ieee80211_regdom, "IEEE 802.11 regulatory domain code"); @@ -243,6 +253,27 @@ static bool regdom_changes(const char *alpha2) return true; } +/* + * The NL80211_REGDOM_SET_BY_USER regdom alpha2 is cached, this lets + * you know if a valid regulatory hint with NL80211_REGDOM_SET_BY_USER + * has ever been issued. + */ +static bool is_user_regdom_saved(void) +{ + if (user_alpha2[0] == '9' && user_alpha2[1] == '7') + return false; + + /* This would indicate a mistake on the design */ + if (WARN((!is_world_regdom(user_alpha2) && + !is_an_alpha2(user_alpha2)), + "Unexpected user alpha2: %c%c\n", + user_alpha2[0], + user_alpha2[1])) + return false; + + 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 @@ -476,12 +507,212 @@ 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) @@ -543,10 +774,29 @@ static struct ieee80211_regdomain *country_ie_2_rd( 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 (triplet->chans.first_channel <= 14) + if (band == IEEE80211_BAND_2GHZ) end_channel = triplet->chans.first_channel + - triplet->chans.num_channels; + triplet->chans.num_channels - 1; else /* * 5 GHz -- For example in country IEs if the first @@ -561,6 +811,24 @@ static struct ieee80211_regdomain *country_ie_2_rd( (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 */ @@ -591,10 +859,13 @@ static struct ieee80211_regdomain *country_ie_2_rd( last_sub_max_channel = cur_sub_max_channel; - country_ie += 3; - country_ie_len -= 3; 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 @@ -637,6 +908,12 @@ static struct ieee80211_regdomain *country_ie_2_rd( continue; } + if (triplet->chans.first_channel == 0) { + country_ie++; + country_ie_len--; + break; + } + reg_rule = &rd->reg_rules[i]; freq_range = ®_rule->freq_range; power_rule = ®_rule->power_rule; @@ -644,13 +921,20 @@ static struct ieee80211_regdomain *country_ie_2_rd( reg_rule->flags = flags; /* 2 GHz */ - if (triplet->chans.first_channel <= 14) + if (band == IEEE80211_BAND_2GHZ) end_channel = triplet->chans.first_channel + - triplet->chans.num_channels; + 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 @@ -671,12 +955,15 @@ static struct ieee80211_regdomain *country_ie_2_rd( */ 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); + power_rule->max_eirp = DBM_TO_MBM(triplet->chans.max_power); - country_ie += 3; - country_ie_len -= 3; i++; + if (country_ie_len >= 3) { + country_ie += 3; + country_ie_len -= 3; + } + BUG_ON(i > NL80211_MAX_SUPP_REG_RULES); } @@ -972,25 +1259,21 @@ static void handle_channel(struct wiphy *wiphy, enum ieee80211_band band, if (r == -ERANGE && last_request->initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE) { -#ifdef CONFIG_CFG80211_REG_DEBUG - printk(KERN_DEBUG "cfg80211: Leaving channel %d MHz " + 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)); -#endif + 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 */ -#ifdef CONFIG_CFG80211_REG_DEBUG if (last_request->initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE) - printk(KERN_DEBUG "cfg80211: Disabling " + REG_DBG_PRINT("cfg80211: Disabling " "channel %d MHz on %s due to " "Country IE\n", chan->center_freq, wiphy_name(wiphy)); -#endif flags |= IEEE80211_CHAN_DISABLED; chan->flags = flags; } @@ -1385,7 +1668,7 @@ static int ignore_request(struct wiphy *wiphy, switch (pending_request->initiator) { case NL80211_REGDOM_SET_BY_CORE: - return -EINVAL; + return 0; case NL80211_REGDOM_SET_BY_COUNTRY_IE: last_wiphy = wiphy_idx_to_wiphy(last_request->wiphy_idx); @@ -1524,6 +1807,11 @@ new_request: pending_request = NULL; + if (last_request->initiator == NL80211_REGDOM_SET_BY_USER) { + user_alpha2[0] = last_request->alpha2[0]; + user_alpha2[1] = last_request->alpha2[1]; + } + /* When r == REG_INTERSECT we do need to call CRDA */ if (r < 0) { /* @@ -1643,12 +1931,16 @@ static void queue_regulatory_request(struct regulatory_request *request) schedule_work(®_work); } -/* Core regulatory hint -- happens once during cfg80211_init() */ +/* + * Core regulatory hint -- happens during cfg80211_init() + * and when we restore regulatory settings. + */ static int regulatory_hint_core(const char *alpha2) { struct regulatory_request *request; - BUG_ON(last_request); + kfree(last_request); + last_request = NULL; request = kzalloc(sizeof(struct regulatory_request), GFP_KERNEL); @@ -1659,14 +1951,12 @@ static int regulatory_hint_core(const char *alpha2) request->alpha2[1] = alpha2[1]; request->initiator = NL80211_REGDOM_SET_BY_CORE; - queue_regulatory_request(request); - /* * This ensures last_request is populated once modules * come swinging in and calling regulatory hints and * wiphy_apply_custom_regulatory(). */ - flush_scheduled_work(); + reg_process_hint(request); return 0; } @@ -1685,7 +1975,7 @@ int regulatory_hint_user(const char *alpha2) request->wiphy_idx = WIPHY_IDX_STALE; request->alpha2[0] = alpha2[0]; request->alpha2[1] = alpha2[1]; - request->initiator = NL80211_REGDOM_SET_BY_USER, + request->initiator = NL80211_REGDOM_SET_BY_USER; queue_regulatory_request(request); @@ -1753,8 +2043,9 @@ static bool reg_same_country_ie_hint(struct wiphy *wiphy, * therefore cannot iterate over the rdev list here. */ void regulatory_hint_11d(struct wiphy *wiphy, - u8 *country_ie, - u8 country_ie_len) + enum ieee80211_band band, + u8 *country_ie, + u8 country_ie_len) { struct ieee80211_regdomain *rd = NULL; char alpha2[2]; @@ -1800,9 +2091,11 @@ void regulatory_hint_11d(struct wiphy *wiphy, wiphy_idx_valid(last_request->wiphy_idx))) goto out; - rd = country_ie_2_rd(country_ie, country_ie_len, &checksum); - if (!rd) + 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 @@ -1845,6 +2138,123 @@ out: mutex_unlock(®_mutex); } +static void restore_alpha2(char *alpha2, bool reset_user) +{ + /* indicates there is no alpha2 to consider for restoration */ + alpha2[0] = '9'; + alpha2[1] = '7'; + + /* The user setting has precedence over the module parameter */ + if (is_user_regdom_saved()) { + /* Unless we're asked to ignore it and reset it */ + if (reset_user) { + REG_DBG_PRINT("cfg80211: Restoring regulatory settings " + "including user preference\n"); + user_alpha2[0] = '9'; + user_alpha2[1] = '7'; + + /* + * If we're ignoring user settings, we still need to + * check the module parameter to ensure we put things + * back as they were for a full restore. + */ + if (!is_world_regdom(ieee80211_regdom)) { + REG_DBG_PRINT("cfg80211: Keeping preference on " + "module parameter ieee80211_regdom: %c%c\n", + ieee80211_regdom[0], + ieee80211_regdom[1]); + alpha2[0] = ieee80211_regdom[0]; + alpha2[1] = ieee80211_regdom[1]; + } + } else { + REG_DBG_PRINT("cfg80211: Restoring regulatory settings " + "while preserving user preference for: %c%c\n", + user_alpha2[0], + user_alpha2[1]); + alpha2[0] = user_alpha2[0]; + alpha2[1] = user_alpha2[1]; + } + } else if (!is_world_regdom(ieee80211_regdom)) { + REG_DBG_PRINT("cfg80211: Keeping preference on " + "module parameter ieee80211_regdom: %c%c\n", + ieee80211_regdom[0], + ieee80211_regdom[1]); + alpha2[0] = ieee80211_regdom[0]; + alpha2[1] = ieee80211_regdom[1]; + } else + REG_DBG_PRINT("cfg80211: Restoring regulatory settings\n"); +} + +/* + * Restoring regulatory settings involves ingoring any + * possibly stale country IE information and user regulatory + * settings if so desired, this includes any beacon hints + * learned as we could have traveled outside to another country + * after disconnection. To restore regulatory settings we do + * exactly what we did at bootup: + * + * - send a core regulatory hint + * - send a user regulatory hint if applicable + * + * Device drivers that send a regulatory hint for a specific country + * keep their own regulatory domain on wiphy->regd so that does does + * not need to be remembered. + */ +static void restore_regulatory_settings(bool reset_user) +{ + char alpha2[2]; + struct reg_beacon *reg_beacon, *btmp; + + mutex_lock(&cfg80211_mutex); + mutex_lock(®_mutex); + + reset_regdomains(); + restore_alpha2(alpha2, reset_user); + + /* Clear beacon hints */ + spin_lock_bh(®_pending_beacons_lock); + if (!list_empty(®_pending_beacons)) { + list_for_each_entry_safe(reg_beacon, btmp, + ®_pending_beacons, list) { + list_del(®_beacon->list); + kfree(reg_beacon); + } + } + spin_unlock_bh(®_pending_beacons_lock); + + if (!list_empty(®_beacon_list)) { + list_for_each_entry_safe(reg_beacon, btmp, + ®_beacon_list, list) { + list_del(®_beacon->list); + kfree(reg_beacon); + } + } + + /* First restore to the basic regulatory settings */ + cfg80211_regdomain = cfg80211_world_regdom; + + mutex_unlock(®_mutex); + mutex_unlock(&cfg80211_mutex); + + regulatory_hint_core(cfg80211_regdomain->alpha2); + + /* + * This restores the ieee80211_regdom module parameter + * preference or the last user requested regulatory + * settings, user regulatory settings takes precedence. + */ + if (is_an_alpha2(alpha2)) + regulatory_hint_user(user_alpha2); +} + + +void regulatory_hint_disconnect(void) +{ + REG_DBG_PRINT("cfg80211: All devices are disconnected, going to " + "restore regulatory settings\n"); + restore_regulatory_settings(false); +} + static bool freq_is_chan_12_13_14(u16 freq) { if (freq == ieee80211_channel_to_frequency(12) || @@ -1870,13 +2280,12 @@ int regulatory_hint_found_beacon(struct wiphy *wiphy, if (!reg_beacon) return -ENOMEM; -#ifdef CONFIG_CFG80211_REG_DEBUG - printk(KERN_DEBUG "cfg80211: Found new beacon on " - "frequency: %d MHz (Ch %d) on %s\n", - beacon_chan->center_freq, - ieee80211_frequency_to_channel(beacon_chan->center_freq), - wiphy_name(wiphy)); -#endif + REG_DBG_PRINT("cfg80211: Found new beacon on " + "frequency: %d MHz (Ch %d) on %s\n", + beacon_chan->center_freq, + ieee80211_frequency_to_channel(beacon_chan->center_freq), + wiphy_name(wiphy)); + memcpy(®_beacon->chan, beacon_chan, sizeof(struct ieee80211_channel)); @@ -2235,6 +2644,9 @@ int regulatory_init(void) cfg80211_regdomain = cfg80211_world_regdom; + user_alpha2[0] = '9'; + user_alpha2[1] = '7'; + /* We always try to get an update for the static regdomain */ err = regulatory_hint_core(cfg80211_regdomain->alpha2); if (err) { |