country: Add function that returns flags for special country

This allows for libloc to be better integrated into third-party
software.

If we would add extra flags, we would be able to extend it in libloc
without touching any third-party software.
Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>

src/country.c

@@ -21,8 +21,20 @@
 #include <libloc/libloc.h>
 #include <libloc/compat.h>
 #include <libloc/country.h>
+#include <libloc/network.h>
 #include <libloc/private.h>
 
+static const struct loc_special_country {
+	const char code[3];
+	enum loc_network_flags flags;
+} loc_special_countries[] = {
+	{ "A1", LOC_NETWORK_FLAG_ANONYMOUS_PROXY },
+	{ "A2", LOC_NETWORK_FLAG_SATELLITE_PROVIDER },
+	{ "A3", LOC_NETWORK_FLAG_ANYCAST },
+	{ "XD", LOC_NETWORK_FLAG_DROP },
+	{ "", 0 },
+};
+
 struct loc_country {
 	struct loc_ctx* ctx;
 	int refcount;
@@ -200,3 +212,20 @@ LOC_EXPORT int loc_country_code_is_valid(const char* cc) {
 	// Looks valid
 	return 1;
 }
+
+LOC_EXPORT int loc_country_special_code_to_flag(const char* cc) {
+	// Check if we got some input
+	if (!cc || !*cc) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	// Return flags for any known special country
+	for (const struct loc_special_country* country = loc_special_countries;
+			country->flags; country++) {
+		if (strcmp(country->code, cc) == 0)
+			return country->flags;
+	}
+
+	return 0;
+}

src/libloc.sym

@@ -39,6 +39,7 @@ global:
 	loc_country_ref;
 	loc_country_set_continent_code;
 	loc_country_set_name;
+	loc_country_special_code_to_flag;
 	loc_country_unref;
 
 	# Country List

src/libloc/country.h

@@ -37,6 +37,7 @@ int loc_country_set_name(struct loc_country* country, const char* name);
 int loc_country_cmp(struct loc_country* country1, struct loc_country* country2);
 
 int loc_country_code_is_valid(const char* cc);
+int loc_country_special_code_to_flag(const char* cc);
 
 #ifdef LIBLOC_PRIVATE
 

src/test-country.c

@@ -29,6 +29,7 @@
 
 int main(int argc, char** argv) {
 	struct loc_country* country;
+	int flag;
 	int err;
 
 	// Check some valid country codes
@@ -43,6 +44,48 @@ int main(int argc, char** argv) {
 		exit(EXIT_FAILURE);
 	}
 
+	// Test special country codes
+	flag = loc_country_special_code_to_flag("XX");
+	if (flag) {
+		fprintf(stderr, "Unexpectedly received a flag for XX: %d\n", flag);
+		exit(EXIT_FAILURE);
+	}
+
+	// A1
+	flag = loc_country_special_code_to_flag("A1");
+	if (flag != LOC_NETWORK_FLAG_ANONYMOUS_PROXY) {
+		fprintf(stderr, "Got a wrong flag for A1: %d\n", flag);
+		exit(EXIT_FAILURE);
+	}
+
+	// A2
+	flag = loc_country_special_code_to_flag("A2");
+	if (flag != LOC_NETWORK_FLAG_SATELLITE_PROVIDER) {
+		fprintf(stderr, "Got a wrong flag for A2: %d\n", flag);
+		exit(EXIT_FAILURE);
+	}
+
+	// A3
+	flag = loc_country_special_code_to_flag("A3");
+	if (flag != LOC_NETWORK_FLAG_ANYCAST) {
+		fprintf(stderr, "Got a wrong flag for A3: %d\n", flag);
+		exit(EXIT_FAILURE);
+	}
+
+	// XD
+	flag = loc_country_special_code_to_flag("XD");
+	if (flag != LOC_NETWORK_FLAG_DROP) {
+		fprintf(stderr, "Got a wrong flag for XD: %d\n", flag);
+		exit(EXIT_FAILURE);
+	}
+
+	// NULL input
+	flag = loc_country_special_code_to_flag(NULL);
+	if (flag >= 0) {
+		fprintf(stderr, "loc_country_special_code_to_flag didn't throw an error for NULL\n");
+		exit(EXIT_FAILURE);
+	}
+
 	struct loc_ctx* ctx;
 	err = loc_new(&ctx);
 	if (err < 0)