diff options
| -rw-r--r-- | net/wireless/reg.c | 166 |
1 files changed, 158 insertions, 8 deletions
diff --git a/net/wireless/reg.c b/net/wireless/reg.c index 34983a8..3f18a1d 100644 --- a/net/wireless/reg.c +++ b/net/wireless/reg.c @@ -50,6 +50,7 @@ struct regulatory_request { struct wiphy *wiphy; enum reg_set_by initiator; char alpha2[2]; + bool intersect; }; static struct regulatory_request *last_request; @@ -359,6 +360,143 @@ static u32 freq_max_bandwidth(const struct ieee80211_freq_range *freq_range, return 0; } +/* Helper for regdom_intersect(), this does the real + * mathematical intersection fun */ +static int reg_rules_intersect( + const struct ieee80211_reg_rule *rule1, + const struct ieee80211_reg_rule *rule2, + struct ieee80211_reg_rule *intersected_rule) +{ + const struct ieee80211_freq_range *freq_range1, *freq_range2; + struct ieee80211_freq_range *freq_range; + const struct ieee80211_power_rule *power_rule1, *power_rule2; + struct ieee80211_power_rule *power_rule; + u32 freq_diff; + + freq_range1 = &rule1->freq_range; + freq_range2 = &rule2->freq_range; + freq_range = &intersected_rule->freq_range; + + power_rule1 = &rule1->power_rule; + power_rule2 = &rule2->power_rule; + power_rule = &intersected_rule->power_rule; + + freq_range->start_freq_khz = max(freq_range1->start_freq_khz, + freq_range2->start_freq_khz); + freq_range->end_freq_khz = min(freq_range1->end_freq_khz, + freq_range2->end_freq_khz); + freq_range->max_bandwidth_khz = min(freq_range1->max_bandwidth_khz, + freq_range2->max_bandwidth_khz); + + freq_diff = freq_range->end_freq_khz - freq_range->start_freq_khz; + if (freq_range->max_bandwidth_khz > freq_diff) + freq_range->max_bandwidth_khz = freq_diff; + + power_rule->max_eirp = min(power_rule1->max_eirp, + power_rule2->max_eirp); + power_rule->max_antenna_gain = min(power_rule1->max_antenna_gain, + power_rule2->max_antenna_gain); + + intersected_rule->flags = (rule1->flags | rule2->flags); + + if (!is_valid_reg_rule(intersected_rule)) + return -EINVAL; + + return 0; +} + +/** + * regdom_intersect - do the intersection between two regulatory domains + * @rd1: first regulatory domain + * @rd2: second regulatory domain + * + * Use this function to get the intersection between two regulatory domains. + * Once completed we will mark the alpha2 for the rd as intersected, "98", + * as no one single alpha2 can represent this regulatory domain. + * + * Returns a pointer to the regulatory domain structure which will hold the + * resulting intersection of rules between rd1 and rd2. We will + * kzalloc() this structure for you. + */ +static struct ieee80211_regdomain *regdom_intersect( + const struct ieee80211_regdomain *rd1, + const struct ieee80211_regdomain *rd2) +{ + int r, size_of_regd; + unsigned int x, y; + unsigned int num_rules = 0, rule_idx = 0; + const struct ieee80211_reg_rule *rule1, *rule2; + struct ieee80211_reg_rule *intersected_rule; + struct ieee80211_regdomain *rd; + /* This is just a dummy holder to help us count */ + struct ieee80211_reg_rule irule; + + /* Uses the stack temporarily for counter arithmetic */ + intersected_rule = &irule; + + memset(intersected_rule, 0, sizeof(struct ieee80211_reg_rule)); + + if (!rd1 || !rd2) + return NULL; + + /* First we get a count of the rules we'll need, then we actually + * build them. This is to so we can malloc() and free() a + * regdomain once. The reason we use reg_rules_intersect() here + * is it will return -EINVAL if the rule computed makes no sense. + * All rules that do check out OK are valid. */ + + for (x = 0; x < rd1->n_reg_rules; x++) { + rule1 = &rd1->reg_rules[x]; + for (y = 0; y < rd2->n_reg_rules; y++) { + rule2 = &rd2->reg_rules[y]; + if (!reg_rules_intersect(rule1, rule2, + intersected_rule)) + num_rules++; + memset(intersected_rule, 0, + sizeof(struct ieee80211_reg_rule)); + } + } + + if (!num_rules) + return NULL; + + size_of_regd = sizeof(struct ieee80211_regdomain) + + ((num_rules + 1) * sizeof(struct ieee80211_reg_rule)); + + rd = kzalloc(size_of_regd, GFP_KERNEL); + if (!rd) + return NULL; + + for (x = 0; x < rd1->n_reg_rules; x++) { + rule1 = &rd1->reg_rules[x]; + for (y = 0; y < rd2->n_reg_rules; y++) { + rule2 = &rd2->reg_rules[y]; + /* This time around instead of using the stack lets + * write to the target rule directly saving ourselves + * a memcpy() */ + intersected_rule = &rd->reg_rules[rule_idx]; + r = reg_rules_intersect(rule1, rule2, + intersected_rule); + /* No need to memset here the intersected rule here as + * we're not using the stack anymore */ + if (r) + continue; + rule_idx++; + } + } + + if (rule_idx != num_rules) { + kfree(rd); + return NULL; + } + + rd->n_reg_rules = num_rules; + rd->alpha2[0] = '9'; + rd->alpha2[1] = '8'; + + return rd; +} + /* XXX: add support for the rest of enum nl80211_reg_rule_flags, we may * want to just have the channel structure use these */ static u32 map_regdom_flags(u32 rd_flags) @@ -468,6 +606,10 @@ void wiphy_update_regulatory(struct wiphy *wiphy, enum reg_set_by setby) } } +/* Return value which can be used by ignore_request() to indicate + * it has been determined we should intersect two regulatory domains */ +#define REG_INTERSECT 1 + /* This has the logic which determines when a new request * should be ignored. */ static int ignore_request(struct wiphy *wiphy, enum reg_set_by set_by, @@ -517,14 +659,8 @@ static int ignore_request(struct wiphy *wiphy, enum reg_set_by set_by, return -EALREADY; return 0; case REGDOM_SET_BY_USER: - /* - * If the user wants to override the AP's hint, we may - * need to follow both and use the intersection. For now, - * reject any such attempt (but we don't support country - * IEs right now anyway.) - */ if (last_request->initiator == REGDOM_SET_BY_COUNTRY_IE) - return -EOPNOTSUPP; + return REG_INTERSECT; return 0; } @@ -536,10 +672,14 @@ int __regulatory_hint(struct wiphy *wiphy, enum reg_set_by set_by, const char *alpha2) { struct regulatory_request *request; + bool intersect = false; int r = 0; r = ignore_request(wiphy, set_by, alpha2); - if (r) + + if (r == REG_INTERSECT) + intersect = true; + else if (r) return r; switch (set_by) { @@ -556,6 +696,7 @@ int __regulatory_hint(struct wiphy *wiphy, enum reg_set_by set_by, request->alpha2[1] = alpha2[1]; request->initiator = set_by; request->wiphy = wiphy; + request->intersect = intersect; kfree(last_request); last_request = request; @@ -648,6 +789,7 @@ static void print_regdomain_info(const struct ieee80211_regdomain *rd) /* 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; /* Some basic sanity checks first */ if (is_world_regdom(rd->alpha2)) { @@ -697,6 +839,14 @@ static int __set_regdom(const struct ieee80211_regdomain *rd) return -EOPNOTSUPP; } + if (unlikely(last_request->intersect)) { + intersected_rd = regdom_intersect(rd, cfg80211_regdomain); + if (!intersected_rd) + return -EINVAL; + kfree(rd); + rd = intersected_rd; + } + /* Tada! */ cfg80211_regdomain = rd; |
