rwrap: Handle trailing dot in dns names.

Signed-off-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Guenther Deschner <gd@samba.org>

2 files changed, 55 insertions, 8 deletions

diff --git a/src/resolv_wrapper.c b/src/resolv_wrapper.c
index 07ec85c..3b94a36 100644
--- a/src/resolv_wrapper.c
+++ b/src/resolv_wrapper.c
@@ -558,6 +558,8 @@ static int rwrap_res_fake_hosts(const char *hostfile,
 	int rc = ENOENT;
 	char *key = NULL;
 	char *value = NULL;
+	char *query_name = NULL;
+	size_t qlen = strlen(query);
 
 	RWRAP_LOG(RWRAP_LOG_TRACE,
 		  "Searching in fake hosts file %s\n", hostfile);
@@ -570,6 +572,15 @@ static int rwrap_res_fake_hosts(const char *hostfile,
 		return -1;
 	}
 
+	if (qlen > 0 && query[qlen-1] == '.') {
+		qlen--;
+	}
+
+	query_name = strndup(query, qlen);
+	if (query_name == NULL) {
+		return -1;
+	}
+
 	while (fgets(buf, sizeof(buf), fp) != NULL) {
 		char *rec_type;
 		char *q;
@@ -593,23 +604,23 @@ static int rwrap_res_fake_hosts(const char *hostfile,
 			continue;
 		}
 
-		if (TYPE_MATCH(type, ns_t_a, rec_type, "A", key, query)) {
+		if (TYPE_MATCH(type, ns_t_a, rec_type, "A", key, query_name)) {
 			rc = rwrap_fake_a(key, value, answer, anslen);
 			break;
 		} else if (TYPE_MATCH(type, ns_t_aaaa,
-				      rec_type, "AAAA", key, query)) {
+				      rec_type, "AAAA", key, query_name)) {
 			rc = rwrap_fake_aaaa(key, value, answer, anslen);
 			break;
 		} else if (TYPE_MATCH(type, ns_t_srv,
-				      rec_type, "SRV", key, query)) {
+				      rec_type, "SRV", key, query_name)) {
 			rc = rwrap_fake_srv(key, value, answer, anslen);
 			break;
 		} else if (TYPE_MATCH(type, ns_t_soa,
-				      rec_type, "SOA", key, query)) {
+				      rec_type, "SOA", key, query_name)) {
 			rc = rwrap_fake_soa(key, value, answer, anslen);
 			break;
 		} else if (TYPE_MATCH(type, ns_t_cname,
-				      rec_type, "CNAME", key, query)) {
+				      rec_type, "CNAME", key, query_name)) {
 			rc = rwrap_fake_cname(key, value, answer, anslen);
 			break;
 		}
@@ -618,19 +629,20 @@ static int rwrap_res_fake_hosts(const char *hostfile,
 	switch (rc) {
 	case 0:
 		RWRAP_LOG(RWRAP_LOG_TRACE,
-				"Successfully faked answer for [%s]\n", query);
+				"Successfully faked answer for [%s]\n", query_name);
 		break;
 	case -1:
 		RWRAP_LOG(RWRAP_LOG_ERROR,
-				"Error faking answer for [%s]\n", query);
+				"Error faking answer for [%s]\n", query_name);
 		break;
 	case ENOENT:
 		RWRAP_LOG(RWRAP_LOG_TRACE,
-				"Record for [%s] not found\n", query);
+				"Record for [%s] not found\n", query_name);
 		rc = rwrap_fake_empty_query(key, type, answer, anslen);
 		break;
 	}
 
+	free(query_name);
 	fclose(fp);
 	return rc;
 }
diff --git a/tests/test_dns_fake.c b/tests/test_dns_fake.c
index b890060..0098e9a 100644
--- a/tests/test_dns_fake.c
+++ b/tests/test_dns_fake.c
@@ -118,6 +118,40 @@ static void test_res_fake_a_query_case_insensitive(void **state)
 	res_nclose(&dnsstate);
 }
 
+static void test_res_fake_a_query_trailing_dot(void **state)
+{
+	int rv;
+	struct __res_state dnsstate;
+	unsigned char answer[ANSIZE];
+	char addr[INET_ADDRSTRLEN];
+	ns_msg handle;
+	ns_rr rr;   /* expanded resource record */
+
+	(void) state; /* unused */
+
+	memset(&dnsstate, 0, sizeof(struct __res_state));
+	rv = res_ninit(&dnsstate);
+	assert_int_equal(rv, 0);
+
+	rv = res_nquery(&dnsstate, "cwrap.org.", ns_c_in, ns_t_a,
+			answer, ANSIZE);
+	assert_int_not_equal(rv, -1);
+
+	ns_initparse(answer, 256, &handle);
+	/* The query must finish w/o an error, have one answer and the answer
+	 * must be a parseable RR of type A and have the address that our
+	 * fake hosts file contains
+	 */
+	assert_int_equal(ns_msg_getflag(handle, ns_f_rcode), ns_r_noerror);
+	assert_int_equal(ns_msg_count(handle, ns_s_an), 1);
+	assert_int_equal(ns_parserr(&handle, ns_s_an, 0, &rr), 0);
+	assert_int_equal(ns_rr_type(rr), ns_t_a);
+	assert_non_null(inet_ntop(AF_INET, ns_rr_rdata(rr), addr, 256));
+	assert_string_equal(addr, "127.0.0.21");
+
+	res_nclose(&dnsstate);
+}
+
 static void test_res_fake_a_query_notfound(void **state)
 {
 	int rv;
@@ -427,6 +461,7 @@ int main(void)
 	const UnitTest tests[] = {
 		unit_test(test_res_fake_a_query),
 		unit_test(test_res_fake_a_query_case_insensitive),
+		unit_test(test_res_fake_a_query_trailing_dot),
 		unit_test(test_res_fake_a_query_notfound),
 		unit_test(test_res_fake_aaaa_query),
 		unit_test(test_res_fake_aaaa_query_notfound),