[PATCH 35/40] crda: separate intersecting a full db into a helper

["Luis R. Rodriguez" <mcgrof@do-not-panic.com>]

From: "Luis R. Rodriguez" <mcgrof@do-not-panic.com>

This should make it easier to review the code and allow
us to stuff it next into reglib. This has no real functional
changes except that of returning NULL in case of any failure
while reading the regdb.

Signed-off-by: Luis R. Rodriguez <mcgrof@do-not-panic.com>
---
 intersect.c |   58 +++++++++++++++++++++++++++++++++++++---------------------
 1 file changed, 37 insertions(+), 21 deletions(-)

diff --git a/intersect.c b/intersect.c
index baca5f1..b9e3429 100644
--- a/intersect.c
+++ b/intersect.c
@@ -6,24 +6,25 @@
 
 #include "reglib.h"
 
-/* Intersects regulatory domains, this will skip any regulatory marked with
- * an alpha2 of '00', which is used to indicate a world regulatory domain */
-
-int main(int argc, char **argv)
+/**
+ * reglib_intersect_regdb - intersects a regulatory database
+ *
+ * @regdb_file: the regulatory database to intersect
+ *
+ * Goes through an entire regulatory database and intersects all regulatory
+ * domains. This will skip any regulatory marked with an alpha2 of '00', which
+ * is used to indicate a world regulatory domain. If intersection is able
+ * to find rules that fit all regulatory domains it return a regulatory
+ * domain with such rules otherwise it returns NULL.
+ */
+const struct ieee80211_regdomain *reglib_intersect_regdb(char *regdb_file)
 {
-	int r = 0;
 	const struct ieee80211_regdomain *rd;
 	struct ieee80211_regdomain *prev_rd_intsct = NULL, *rd_intsct = NULL;
 	int intersected = 0;
 	unsigned int idx = 0;
 
-	if (argc != 2) {
-		fprintf(stderr, "You must specify a file\n");
-		return -EINVAL;
-	}
-
-	/* We intersect only when we have to rd structures ready */
-	reglib_for_each_country(rd, idx, argv[1]) {
+	reglib_for_each_country(rd, idx, regdb_file) {
 		if (reglib_is_world_regdom((const char *) rd->alpha2)) {
 			free((struct ieee80211_regdomain *) rd);
 			continue;
@@ -43,7 +44,7 @@ int main(int argc, char **argv)
 		if (!rd_intsct) {
 			free(prev_rd_intsct);
 			free((struct ieee80211_regdomain *) rd);
-			return -ENOENT;
+			return NULL;
 		}
 
 		intersected++;
@@ -51,25 +52,40 @@ int main(int argc, char **argv)
 	}
 
 	if (!idx)
-		return -EINVAL;
+		return NULL;
 
 	if (intersected <= 0) {
 		rd_intsct = prev_rd_intsct;
 		prev_rd_intsct = NULL;
 		if (idx > 1) {
-			r = -ENOENT;
 			free(rd_intsct);
-			return r;
+			return NULL;
 		}
 	}
 
 	if (prev_rd_intsct)
 		free(prev_rd_intsct);
 
-	/* Tada! */
-	printf("Intersected regulatory domain:\n");
-	reglib_print_regdom(rd_intsct);
+	return rd_intsct;
+}
+
+int main(int argc, char **argv)
+{
+	const struct ieee80211_regdomain *rd;
+
+	if (argc != 2) {
+		fprintf(stderr, "You must specify a file\n");
+		return -EINVAL;
+	}
+
+	rd = reglib_intersect_regdb(argv[1]);
+	if (!rd) {
+		fprintf(stderr, "Intersection not possible\n");
+		return -ENOENT;
+	}
+
+	reglib_print_regdom(rd);
+	free((struct ieee80211_regdomain *) rd);
 
-	free(rd_intsct);
-	return r;
+	return 0;
 }
-- 
1.7.10.4