Unit tests for subdomain check and fixes.

src/libknot/dname.c

@@ -88,7 +88,7 @@ static int knot_dname_str_to_wire(const char *name, uint size,
 	const uint8_t *np = ch + size;
 	uint8_t *label = wire;
 	uint8_t *w = wire + 1; /* Reserve 1 for label len */
-	while (*ch != *np) {
+	while (ch != np) {
 		if (*ch == '.') {
 			/* Zero-length label inside a dname - invalid. */
 			if (*label == 0) {
@@ -564,8 +564,8 @@ int knot_dname_is_subdomain(const knot_dname_t *sub,
 	int sub_l = knot_dname_wire_labels(sub_p, NULL);
 	int domain_l = knot_dname_wire_labels(domain_p, NULL);
 
-	/* Subdomain can't have >= labels as parent. */
-	if (sub_l >= domain_l)
+	/* Subdomain must have more labels as parent. */
+	if (sub_l <= domain_l)
 		return 0;
 
 	/* Align end-to-end to common suffix. */
@@ -713,10 +713,6 @@ knot_dname_t *knot_dname_cat(knot_dname_t *d1, const knot_dname_t *d2)
 		return d1;
 	}
 
-	if (knot_dname_is_fqdn(d1)) {
-		return NULL;
-	}
-
 	// allocate new space
 	uint8_t *new_dname = (uint8_t *)malloc(d1->size + d2->size);
 	CHECK_ALLOC_LOG(new_dname, NULL);
@@ -827,6 +823,7 @@ int knot_dname_wire_labels(const uint8_t *name, const uint8_t *pkt)
 {
 	uint8_t count = 0;
 	while (*name != '\0') {
+		++count;
 		name = knot_wire_next_label((uint8_t *)name, (uint8_t *)pkt);
 		if (!name)
 			return KNOT_EMALF;

src/tests/libknot/dname_tests.c

@@ -35,12 +35,12 @@ unit_api dname_tests_api = {
 
 static int dname_tests_count(int argc, char *argv[])
 {
-	return 11;
+	return 15;
 }
 
 static int dname_tests_run(int argc, char *argv[])
 {
-	knot_dname_t *d = NULL;
+	knot_dname_t *d = NULL, *d2 = NULL;
 	const char *w = NULL, *t = NULL;
 	unsigned len = 0;
 
@@ -93,5 +93,32 @@ static int dname_tests_run(int argc, char *argv[])
 	d = knot_dname_new_from_str(t, strlen(t), NULL);
 	ok(d == NULL, "dname_fromstr: parsed incorrect name");
 
+	/* 12. equal name is subdomain */
+	t = "ab.cd.ef";
+	d2 = knot_dname_new_from_str(t, strlen(t), NULL);
+	t = "ab.cd.ef";
+	d = knot_dname_new_from_str(t, strlen(t), NULL);
+	ok(!knot_dname_is_subdomain(d, d2), "dname_subdomain: equal name");
+	knot_dname_free(&d);
+
+	/* 13. true subdomain */
+	t = "0.ab.cd.ef";
+	d = knot_dname_new_from_str(t, strlen(t), NULL);
+	ok(knot_dname_is_subdomain(d, d2), "dname_subdomain: true subdomain");
+	knot_dname_free(&d);
+
+	/* 14. not subdomain */
+	t = "cd.ef";
+	d = knot_dname_new_from_str(t, strlen(t), NULL);
+	ok(!knot_dname_is_subdomain(d, d2), "dname_subdomain: not subdomain");
+	knot_dname_free(&d);
+
+	/* 15. root subdomain */
+	t = ".";
+	d = knot_dname_new_from_str(t, strlen(t), NULL);
+	ok(knot_dname_is_subdomain(d2, d), "dname_subdomain: root subdomain");
+	knot_dname_free(&d);
+	knot_dname_free(&d2);
+
 	return 0;
 }