net: dns: Do not resolve numeric IP address

If the query name is already in numeric format, there is no
need to send the query string to DNS server as we can just
convert it ourselves.

Jira: ZEP-2562

Signed-off-by: Jukka Rissanen <[email protected]>

Author: jukkar

subsys/net/lib/dns/resolve.c

@@ -610,6 +610,7 @@ int dns_resolve_name(struct dns_resolve_context *ctx,
 {
 	struct net_buf *dns_data;
 	struct net_buf *dns_qname = NULL;
+	struct sockaddr addr;
 	int ret, i, j = 0;
 	int failure = 0;
 
@@ -623,6 +624,36 @@ int dns_resolve_name(struct dns_resolve_context *ctx,
 		return -EINVAL;
 	}
 
+	ret = net_ipaddr_parse(query, strlen(query), &addr);
+	if (ret) {
+		/* The query name was already in numeric form, no
+		 * need to continue further.
+		 */
+		struct dns_addrinfo info = { 0 };
+
+		if (type == DNS_QUERY_TYPE_A) {
+			memcpy(net_sin(&info.ai_addr), net_sin(&addr),
+			       sizeof(struct sockaddr_in));
+			info.ai_family = AF_INET;
+			info.ai_addr.sa_family = AF_INET;
+			info.ai_addrlen = sizeof(struct sockaddr_in);
+		} else if (type == DNS_QUERY_TYPE_AAAA) {
+			memcpy(net_sin6(&info.ai_addr), net_sin6(&addr),
+			       sizeof(struct sockaddr_in6));
+			info.ai_family = AF_INET6;
+			info.ai_addr.sa_family = AF_INET6;
+			info.ai_addrlen = sizeof(struct sockaddr_in6);
+		} else {
+			goto try_resolve;
+		}
+
+		cb(DNS_EAI_INPROGRESS, &info, user_data);
+		cb(DNS_EAI_ALLDONE, NULL, user_data);
+
+		return 0;
+	}
+
+try_resolve:
 	i = get_cb_slot(ctx);
 	if (i < 0) {
 		return -EAGAIN;

tests/net/lib/dns_resolve/prj.conf

@@ -16,7 +16,7 @@ CONFIG_DNS_SERVER3="192.0.2.2:5353"
 CONFIG_DNS_SERVER4="[2001:db8::2]:5353"
 
 CONFIG_NET_LOG=y
-CONFIG_SYS_LOG_NET_LEVEL=4
+CONFIG_SYS_LOG_NET_LEVEL=2
 CONFIG_SYS_LOG_SHOW_COLOR=y
 #CONFIG_NET_DEBUG_DNS_RESOLVE=y
 
@@ -29,3 +29,5 @@ CONFIG_NET_ARP=n
 
 CONFIG_PRINTK=y
 CONFIG_ZTEST=y
+
+CONFIG_MAIN_STACK_SIZE=1344

tests/net/lib/dns_resolve/src/main.c

@@ -30,13 +30,17 @@
 
 #define NAME4 "4.zephyr.test"
 #define NAME6 "6.zephyr.test"
+#define NAME_IPV4 "192.0.2.1"
+#define NAME_IPV6 "2001:db8::1"
 
 #define DNS_TIMEOUT 500 /* ms */
 
 #if defined(CONFIG_NET_IPV6)
 /* Interface 1 addresses */
 static struct in6_addr my_addr1 = { { { 0x20, 0x01, 0x0d, 0xb8, 1, 0, 0, 0,
 					0, 0, 0, 0, 0, 0, 0, 0x1 } } };
+static struct in6_addr my_addr3 = { { { 0x20, 0x01, 0x0d, 0xb8, 0, 0, 0, 0,
+					0, 0, 0, 0, 0, 0, 0, 0x1 } } };
 
 /* Extra address is assigned to ll_addr */
 static struct in6_addr ll_addr = { { { 0xfe, 0x80, 0x43, 0xb8, 0, 0, 0, 0,
@@ -637,6 +641,101 @@ static void dns_query_ipv6(void)
 	}
 }
 
+struct expected_addr_status {
+	struct sockaddr addr;
+	int status1;
+	int status2;
+	const char *caller;
+};
+
+void dns_result_numeric_cb(enum dns_resolve_status status,
+			   struct dns_addrinfo *info,
+			   void *user_data)
+{
+	struct expected_addr_status *expected = user_data;
+
+	if (status != expected->status1 && status != expected->status2) {
+		DBG("Result status %d\n", status);
+		DBG("Expected status1 %d\n", expected->status1);
+		DBG("Expected status2 %d\n", expected->status2);
+		DBG("Caller %s\n", expected->caller);
+
+		zassert_true(false, "Invalid status");
+	}
+
+	if (info && info->ai_family == AF_INET) {
+		if (net_ipv4_addr_cmp(&net_sin(&info->ai_addr)->sin_addr,
+				      &my_addr2) != true) {
+			zassert_true(false, "IPv4 address does not match");
+		}
+	}
+
+	if (info && info->ai_family == AF_INET6) {
+		if (net_ipv6_addr_cmp(&net_sin6(&info->ai_addr)->sin6_addr,
+				      &my_addr3) != true) {
+			zassert_true(false, "IPv6 address does not match");
+		}
+	}
+
+	k_sem_give(&wait_data2);
+}
+
+static void dns_query_ipv4_numeric(void)
+{
+	struct expected_addr_status status = {
+		.status1 = DNS_EAI_INPROGRESS,
+		.status2 = DNS_EAI_ALLDONE,
+		.caller = __func__,
+	};
+	int ret;
+
+	timeout_query = false;
+
+	ret = dns_get_addr_info(NAME_IPV4,
+				DNS_QUERY_TYPE_A,
+				&current_dns_id,
+				dns_result_numeric_cb,
+				&status,
+				DNS_TIMEOUT);
+	zassert_equal(ret, 0, "Cannot create IPv4 numeric query");
+
+	DBG("Query id %u\n", current_dns_id);
+
+	k_yield(); /* mandatory so that net_if send func gets to run */
+
+	if (k_sem_take(&wait_data2, WAIT_TIME)) {
+		zassert_true(false, "Timeout while waiting data");
+	}
+}
+
+static void dns_query_ipv6_numeric(void)
+{
+	struct expected_addr_status status = {
+		.status1 = DNS_EAI_INPROGRESS,
+		.status2 = DNS_EAI_ALLDONE,
+		.caller = __func__,
+	};
+	int ret;
+
+	timeout_query = false;
+
+	ret = dns_get_addr_info(NAME_IPV6,
+				DNS_QUERY_TYPE_AAAA,
+				&current_dns_id,
+				dns_result_numeric_cb,
+				&status,
+				DNS_TIMEOUT);
+	zassert_equal(ret, 0, "Cannot create IPv6 query");
+
+	DBG("Query id %u\n", current_dns_id);
+
+	k_yield(); /* mandatory so that net_if send func gets to run */
+
+	if (k_sem_take(&wait_data2, WAIT_TIME)) {
+		zassert_true(false, "Timeout while waiting data");
+	}
+}
+
 void test_main(void)
 {
 	ztest_test_suite(dns_tests,
@@ -654,7 +753,9 @@ void test_main(void)
 			 ztest_unit_test(dns_query_ipv4_cancel),
 			 ztest_unit_test(dns_query_ipv6_cancel),
 			 ztest_unit_test(dns_query_ipv4),
-			 ztest_unit_test(dns_query_ipv6));
+			 ztest_unit_test(dns_query_ipv6),
+			 ztest_unit_test(dns_query_ipv4_numeric),
+			 ztest_unit_test(dns_query_ipv6_numeric));
 
 	ztest_run_test_suite(dns_tests);
 }