reglib: add reglib_is_valid_rd() and verify data upon build

This will verify the sanity of a regulatory domain upon build
time. This is useful if you are making modifications to
wireless-regdb and need to verify the regulatory domains
won't be rejected by a similar checker. In the case of the
Linux kernel regulatory domain data structures that get
a complaint would have been rejected completely.

Signed-off-by: Luis R. Rodriguez <mcgrof@do-not-panic.com>
diff --git a/regdbdump.c b/regdbdump.c
index cc7eb85..bb83af9 100644
--- a/regdbdump.c
+++ b/regdbdump.c
@@ -8,6 +8,11 @@
 	unsigned int idx = 0;
 
 	reglib_for_each_country(rd, idx, ctx) {
+		if (!reglib_is_valid_rd(rd)) {
+			fprintf(stderr, "country %.2s: invalid\n", rd->alpha2);
+			free((struct ieee80211_regdomain *) rd);
+			continue;
+		}
 		reglib_print_regdom(rd);
 		free((struct ieee80211_regdomain *) rd);
 	}
diff --git a/reglib.c b/reglib.c
index 224821b..64584f4 100644
--- a/reglib.c
+++ b/reglib.c
@@ -427,6 +427,22 @@
 	return 1;
 }
 
+int reglib_is_valid_rd(const struct ieee80211_regdomain *rd)
+{
+	const struct ieee80211_reg_rule *reg_rule = NULL;
+	unsigned int i;
+
+	if (!rd->n_reg_rules)
+		return 0;
+
+	for (i = 0; i < rd->n_reg_rules; i++) {
+		reg_rule = &rd->reg_rules[i];
+		if (!is_valid_reg_rule(reg_rule))
+		return 0;
+	}
+	return 1;
+}
+
 /*
  * Helper for reglib_intersect_rds(), this does the real
  * mathematical intersection fun
diff --git a/reglib.h b/reglib.h
index 57082fe..7a586a3 100644
--- a/reglib.h
+++ b/reglib.h
@@ -150,6 +150,16 @@
 const struct ieee80211_regdomain *
 reglib_get_rd_alpha2(const char *alpha2, const char *file);
 
+/**
+ * reglib_is_valid_rd - validate regulatory domain data structure
+ *
+ * @rd: regulatory domain data structure to validate
+ *
+ * You can use this to validate regulatory domain data structures
+ * for possible inconsistencies.
+ */
+int reglib_is_valid_rd(const struct ieee80211_regdomain *rd);
+
 /* reg helpers */
 void reglib_print_regdom(const struct ieee80211_regdomain *rd);
 struct ieee80211_regdomain *