cfg80211: reg: make CRDA support optional

If there's a built-in regulatory database, there may be little point
in also calling out to CRDA and failing if the system is configured
that way. Allow removing CRDA support to save ~1K kernel size.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

3 files changed, 114 insertions, 73 deletions

diff --git a/net/wireless/Kconfig b/net/wireless/Kconfig
index 4f5543dd2524..da72ed32f143 100644
--- a/net/wireless/Kconfig
+++ b/net/wireless/Kconfig
@@ -174,6 +174,16 @@ config CFG80211_INTERNAL_REGDB
 
           Most distributions have a CRDA package.  So if unsure, say N.
 
+config CFG80211_CRDA_SUPPORT
+        bool "support CRDA" if CFG80211_INTERNAL_REGDB
+        default y
+        depends on CFG80211
+        help
+          You should enable this option unless you know for sure you have no
+          need for it, for example when using internal regdb (above.)
+
+          If unsure, say Y.
+
 config CFG80211_WEXT
         bool "cfg80211 wireless extensions compatibility" if !CFG80211_WEXT_EXPORT
         depends on CFG80211
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 28c29e7da749..d693c9d031fc 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -4944,56 +4944,6 @@ static int nl80211_set_bss(struct sk_buff *skb, struct genl_info *info)
         return err;
 }
 
-static const struct nla_policy reg_rule_policy[NL80211_REG_RULE_ATTR_MAX + 1] = {
-        [NL80211_ATTR_REG_RULE_FLAGS]           = { .type = NLA_U32 },
-        [NL80211_ATTR_FREQ_RANGE_START]         = { .type = NLA_U32 },
-        [NL80211_ATTR_FREQ_RANGE_END]           = { .type = NLA_U32 },
-        [NL80211_ATTR_FREQ_RANGE_MAX_BW]        = { .type = NLA_U32 },
-        [NL80211_ATTR_POWER_RULE_MAX_ANT_GAIN]  = { .type = NLA_U32 },
-        [NL80211_ATTR_POWER_RULE_MAX_EIRP]      = { .type = NLA_U32 },
-        [NL80211_ATTR_DFS_CAC_TIME]             = { .type = NLA_U32 },
-};
-
-static int parse_reg_rule(struct nlattr *tb[],
-        struct ieee80211_reg_rule *reg_rule)
-{
-        struct ieee80211_freq_range *freq_range = &reg_rule->freq_range;
-        struct ieee80211_power_rule *power_rule = &reg_rule->power_rule;
-
-        if (!tb[NL80211_ATTR_REG_RULE_FLAGS])
-                return -EINVAL;
-        if (!tb[NL80211_ATTR_FREQ_RANGE_START])
-                return -EINVAL;
-        if (!tb[NL80211_ATTR_FREQ_RANGE_END])
-                return -EINVAL;
-        if (!tb[NL80211_ATTR_FREQ_RANGE_MAX_BW])
-                return -EINVAL;
-        if (!tb[NL80211_ATTR_POWER_RULE_MAX_EIRP])
-                return -EINVAL;
-
-        reg_rule->flags = nla_get_u32(tb[NL80211_ATTR_REG_RULE_FLAGS]);
-
-        freq_range->start_freq_khz =
-                nla_get_u32(tb[NL80211_ATTR_FREQ_RANGE_START]);
-        freq_range->end_freq_khz =
-                nla_get_u32(tb[NL80211_ATTR_FREQ_RANGE_END]);
-        freq_range->max_bandwidth_khz =
-                nla_get_u32(tb[NL80211_ATTR_FREQ_RANGE_MAX_BW]);
-
-        power_rule->max_eirp =
-                nla_get_u32(tb[NL80211_ATTR_POWER_RULE_MAX_EIRP]);
-
-        if (tb[NL80211_ATTR_POWER_RULE_MAX_ANT_GAIN])
-                power_rule->max_antenna_gain =
-                        nla_get_u32(tb[NL80211_ATTR_POWER_RULE_MAX_ANT_GAIN]);
-
-        if (tb[NL80211_ATTR_DFS_CAC_TIME])
-                reg_rule->dfs_cac_ms =
-                        nla_get_u32(tb[NL80211_ATTR_DFS_CAC_TIME]);
-
-        return 0;
-}
-
 static int nl80211_req_set_reg(struct sk_buff *skb, struct genl_info *info)
 {
         char *data = NULL;
@@ -5625,6 +5575,57 @@ out_err:
         return err;
 }
 
+#ifdef CONFIG_CFG80211_CRDA_SUPPORT
+static const struct nla_policy reg_rule_policy[NL80211_REG_RULE_ATTR_MAX + 1] = {
+        [NL80211_ATTR_REG_RULE_FLAGS]           = { .type = NLA_U32 },
+        [NL80211_ATTR_FREQ_RANGE_START]         = { .type = NLA_U32 },
+        [NL80211_ATTR_FREQ_RANGE_END]           = { .type = NLA_U32 },
+        [NL80211_ATTR_FREQ_RANGE_MAX_BW]        = { .type = NLA_U32 },
+        [NL80211_ATTR_POWER_RULE_MAX_ANT_GAIN]  = { .type = NLA_U32 },
+        [NL80211_ATTR_POWER_RULE_MAX_EIRP]      = { .type = NLA_U32 },
+        [NL80211_ATTR_DFS_CAC_TIME]             = { .type = NLA_U32 },
+};
+
+static int parse_reg_rule(struct nlattr *tb[],
+        struct ieee80211_reg_rule *reg_rule)
+{
+        struct ieee80211_freq_range *freq_range = &reg_rule->freq_range;
+        struct ieee80211_power_rule *power_rule = &reg_rule->power_rule;
+
+        if (!tb[NL80211_ATTR_REG_RULE_FLAGS])
+                return -EINVAL;
+        if (!tb[NL80211_ATTR_FREQ_RANGE_START])
+                return -EINVAL;
+        if (!tb[NL80211_ATTR_FREQ_RANGE_END])
+                return -EINVAL;
+        if (!tb[NL80211_ATTR_FREQ_RANGE_MAX_BW])
+                return -EINVAL;
+        if (!tb[NL80211_ATTR_POWER_RULE_MAX_EIRP])
+                return -EINVAL;
+
+        reg_rule->flags = nla_get_u32(tb[NL80211_ATTR_REG_RULE_FLAGS]);
+
+        freq_range->start_freq_khz =
+                nla_get_u32(tb[NL80211_ATTR_FREQ_RANGE_START]);
+        freq_range->end_freq_khz =
+                nla_get_u32(tb[NL80211_ATTR_FREQ_RANGE_END]);
+        freq_range->max_bandwidth_khz =
+                nla_get_u32(tb[NL80211_ATTR_FREQ_RANGE_MAX_BW]);
+
+        power_rule->max_eirp =
+                nla_get_u32(tb[NL80211_ATTR_POWER_RULE_MAX_EIRP]);
+
+        if (tb[NL80211_ATTR_POWER_RULE_MAX_ANT_GAIN])
+                power_rule->max_antenna_gain =
+                        nla_get_u32(tb[NL80211_ATTR_POWER_RULE_MAX_ANT_GAIN]);
+
+        if (tb[NL80211_ATTR_DFS_CAC_TIME])
+                reg_rule->dfs_cac_ms =
+                        nla_get_u32(tb[NL80211_ATTR_DFS_CAC_TIME]);
+
+        return 0;
+}
+
 static int nl80211_set_reg(struct sk_buff *skb, struct genl_info *info)
 {
         struct nlattr *tb[NL80211_REG_RULE_ATTR_MAX + 1];
@@ -5701,6 +5702,7 @@ static int nl80211_set_reg(struct sk_buff *skb, struct genl_info *info)
         kfree(rd);
         return r;
 }
+#endif /* CONFIG_CFG80211_CRDA_SUPPORT */
 
 static int validate_scan_freqs(struct nlattr *freqs)
 {
@@ -10895,6 +10897,7 @@ static const struct genl_ops nl80211_ops[] = {
                 .internal_flags = NL80211_FLAG_NEED_RTNL,
                 /* can be retrieved by unprivileged users */
         },
+#ifdef CONFIG_CFG80211_CRDA_SUPPORT
         {
                 .cmd = NL80211_CMD_SET_REG,
                 .doit = nl80211_set_reg,
@@ -10902,6 +10905,7 @@ static const struct genl_ops nl80211_ops[] = {
                 .flags = GENL_ADMIN_PERM,
                 .internal_flags = NL80211_FLAG_NEED_RTNL,
         },
+#endif
         {
                 .cmd = NL80211_CMD_REQ_SET_REG,
                 .doit = nl80211_req_set_reg,
diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index 3b3119fa87ae..55462fe04d5d 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -135,10 +135,7 @@ static spinlock_t reg_indoor_lock;
 /* Used to track the userspace process controlling the indoor setting */
 static u32 reg_is_indoor_portid;
 
-/* Max number of consecutive attempts to communicate with CRDA  */
-#define REG_MAX_CRDA_TIMEOUTS 10
-
-static u32 reg_crda_timeouts;
+static void restore_regulatory_settings(bool reset_user);
 
 static const struct ieee80211_regdomain *get_cfg80211_regdom(void)
 {
@@ -226,9 +223,6 @@ static DECLARE_DELAYED_WORK(reg_check_chans, reg_check_chans_work);
 static void reg_todo(struct work_struct *work);
 static DECLARE_WORK(reg_work, reg_todo);
 
-static void reg_timeout_work(struct work_struct *work);
-static DECLARE_DELAYED_WORK(reg_timeout, reg_timeout_work);
-
 /* We keep a static world regulatory domain in case of the absence of CRDA */
 static const struct ieee80211_regdomain world_regdom = {
         .n_reg_rules = 8,
@@ -533,6 +527,39 @@ static inline int reg_regdb_query(const char *alpha2)
 }
 #endif /* CONFIG_CFG80211_INTERNAL_REGDB */
 
+#ifdef CONFIG_CFG80211_CRDA_SUPPORT
+/* Max number of consecutive attempts to communicate with CRDA  */
+#define REG_MAX_CRDA_TIMEOUTS 10
+
+static u32 reg_crda_timeouts;
+
+static void crda_timeout_work(struct work_struct *work);
+static DECLARE_DELAYED_WORK(crda_timeout, crda_timeout_work);
+
+static void crda_timeout_work(struct work_struct *work)
+{
+        REG_DBG_PRINT("Timeout while waiting for CRDA to reply, restoring regulatory settings\n");
+        rtnl_lock();
+        reg_crda_timeouts++;
+        restore_regulatory_settings(true);
+        rtnl_unlock();
+}
+
+static void cancel_crda_timeout(void)
+{
+        cancel_delayed_work(&crda_timeout);
+}
+
+static void cancel_crda_timeout_sync(void)
+{
+        cancel_delayed_work_sync(&crda_timeout);
+}
+
+static void reset_crda_timeouts(void)
+{
+        reg_crda_timeouts = 0;
+}
+
 /*
  * This lets us keep regulatory code which is updated on a regulatory
  * basis in userspace.
@@ -562,9 +589,18 @@ static int call_crda(const char *alpha2)
                 return ret;
 
         queue_delayed_work(system_power_efficient_wq,
-                           &reg_timeout, msecs_to_jiffies(3142));
+                           &crda_timeout, msecs_to_jiffies(3142));
         return 0;
 }
+#else
+static inline void cancel_crda_timeout(void) {}
+static inline void cancel_crda_timeout_sync(void) {}
+static inline void reset_crda_timeouts(void) {}
+static inline int call_crda(const char *alpha2)
+{
+        return -ENODATA;
+}
+#endif /* CONFIG_CFG80211_CRDA_SUPPORT */
 
 static bool reg_query_database(struct regulatory_request *request)
 {
@@ -1856,7 +1892,7 @@ static void reg_set_request_processed(void)
                 need_more_processing = true;
         spin_unlock(&reg_requests_lock);
 
-        cancel_delayed_work(&reg_timeout);
+        cancel_crda_timeout();
 
         if (need_more_processing)
                 schedule_work(&reg_work);
@@ -2355,7 +2391,7 @@ int regulatory_hint_user(const char *alpha2,
         request->user_reg_hint_type = user_reg_hint_type;
 
         /* Allow calling CRDA again */
-        reg_crda_timeouts = 0;
+        reset_crda_timeouts();
 
         queue_regulatory_request(request);
 
@@ -2427,7 +2463,7 @@ int regulatory_hint(struct wiphy *wiphy, const char *alpha2)
         request->initiator = NL80211_REGDOM_SET_BY_DRIVER;
 
         /* Allow calling CRDA again */
-        reg_crda_timeouts = 0;
+        reset_crda_timeouts();
 
         queue_regulatory_request(request);
 
@@ -2483,7 +2519,7 @@ void regulatory_hint_country_ie(struct wiphy *wiphy, enum ieee80211_band band,
         request->country_ie_env = env;
 
         /* Allow calling CRDA again */
-        reg_crda_timeouts = 0;
+        reset_crda_timeouts();
 
         queue_regulatory_request(request);
         request = NULL;
@@ -2970,7 +3006,7 @@ int set_regdom(const struct ieee80211_regdomain *rd,
         }
 
         if (regd_src == REGD_SOURCE_CRDA)
-                reg_crda_timeouts = 0;
+                reset_crda_timeouts();
 
         lr = get_last_request();
 
@@ -3127,15 +3163,6 @@ void wiphy_regulatory_deregister(struct wiphy *wiphy)
         lr->country_ie_env = ENVIRON_ANY;
 }
 
-static void reg_timeout_work(struct work_struct *work)
-{
-        REG_DBG_PRINT("Timeout while waiting for CRDA to reply, restoring regulatory settings\n");
-        rtnl_lock();
-        reg_crda_timeouts++;
-        restore_regulatory_settings(true);
-        rtnl_unlock();
-}
-
 /*
  * See http://www.fcc.gov/document/5-ghz-unlicensed-spectrum-unii, for
  * UNII band definitions
@@ -3221,7 +3248,7 @@ void regulatory_exit(void)
         struct reg_beacon *reg_beacon, *btmp;
 
         cancel_work_sync(&reg_work);
-        cancel_delayed_work_sync(&reg_timeout);
+        cancel_crda_timeout_sync();
         cancel_delayed_work_sync(&reg_check_chans);
 
         /* Lock to suppress warnings */