tests: net: arp: test the packet queuing case

Test the case where the packet provided to `net_arp_prepare` is queued
for later transmission, instead of being replaced with an ARP query
or having ARP information populated.

Signed-off-by: Jordan Yates <[email protected]>

Author: JordanYates

tests/net/arp/src/main.c

@@ -316,6 +316,7 @@ ZTEST(arp_fn_tests, test_arp)
 	struct net_eth_addr dst_lladdr;
 	struct net_pkt *pkt;
 	struct net_pkt *pkt2;
+	struct net_pkt *pkt_arp;
 	struct net_if *iface;
 	struct net_if_addr *ifaddr;
 	struct net_arp_hdr *arp_hdr;
@@ -367,25 +368,30 @@ ZTEST(arp_fn_tests, test_arp)
 
 	memcpy(net_buf_add(pkt->buffer, len), app_data, len);
 
-	ret = net_arp_prepare(pkt, &dst, NULL, &pkt2);
+	/* Duplicate packet */
+	pkt2 = net_pkt_clone(pkt, K_SECONDS(1));
+	zassert_not_null(pkt2, "out of mem");
+
+	/* First ARP request */
+	ret = net_arp_prepare(pkt, &dst, NULL, &pkt_arp);
 
 	zassert_equal(NET_ARP_PKT_REPLACED, ret);
 
-	/* pkt2 is the ARP packet and pkt is the IPv4 packet and it was
+	/* pkt_arp is the ARP packet and pkt is the IPv4 packet and it was
 	 * stored in ARP table.
 	 */
 
-	zassert_equal(net_pkt_ll_proto_type(pkt2), NET_ETH_PTYPE_ARP,
+	zassert_equal(net_pkt_ll_proto_type(pkt_arp), NET_ETH_PTYPE_ARP,
 		      "ARP packet type is wrong");
 
 	/**TESTPOINTS: Check packets*/
-	zassert_not_equal((void *)(pkt2), (void *)(pkt),
+	zassert_not_equal((void *)(pkt_arp), (void *)(pkt),
 		/* The packets cannot be the same as the ARP cache has
 		 * still room for the pkt.
 		 */
 		"ARP cache should still have free space");
 
-	zassert_not_null(pkt2, "ARP pkt is empty");
+	zassert_not_null(pkt_arp, "ARP pkt is empty");
 
 	/* The ARP cache should now have a link to pending net_pkt
 	 * that is to be sent after we have got an ARP reply.
@@ -395,8 +401,8 @@ ZTEST(arp_fn_tests, test_arp)
 
 	pending_pkt = pkt;
 
-	/* pkt2 should contain the arp header, verify it */
-	arp_hdr = NET_ARP_HDR(pkt2);
+	/* pkt_arp should contain the arp header, verify it */
+	arp_hdr = NET_ARP_HDR(pkt_arp);
 
 	if (arp_hdr->hwtype != htons(NET_ARP_HTYPE_ETH)) {
 		printk("ARP hwtype 0x%x, should be 0x%x\n",
@@ -447,26 +453,41 @@ ZTEST(arp_fn_tests, test_arp)
 	/* We could have send the new ARP request but for this test we
 	 * just free it.
 	 */
-	net_pkt_unref(pkt2);
+	net_pkt_unref(pkt_arp);
 
 	zassert_equal(atomic_get(&pkt->atomic_ref), 2,
 		"ARP cache should own the original packet");
 
+
+	/* A second packet going to the same destination */
+	pkt_arp = NULL;
+	ret = net_arp_prepare(pkt2, &dst, NULL, &pkt_arp);
+
+	/* Packet should have been queued, not generating an ARP request */
+	zassert_equal(NET_ARP_PKT_QUEUED, ret);
+	zassert_is_null(pkt_arp, "ARP packet should not have been generated");
+
+	zassert_equal(atomic_get(&pkt2->atomic_ref), 2,
+		"ARP cache should own the original packet");
+
+	/* Done with the duplicate packet */
+	net_pkt_unref(pkt2);
+
 	/* Then a case where target is not in the same subnet */
 	net_ipv4_addr_copy_raw(ipv4->dst, (uint8_t *)&dst_far);
 
-	ret = net_arp_prepare(pkt, &dst_far, NULL, &pkt2);
+	ret = net_arp_prepare(pkt, &dst_far, NULL, &pkt_arp);
 
 	zassert_equal(NET_ARP_PKT_REPLACED, ret);
 
-	zassert_not_equal((void *)(pkt2), (void *)(pkt),
+	zassert_not_equal((void *)(pkt_arp), (void *)(pkt),
 		"ARP cache should not find anything");
 
 	/**TESTPOINTS: Check if packets not empty*/
-	zassert_not_null(pkt2,
-		"ARP pkt2 is empty");
+	zassert_not_null(pkt_arp,
+		"ARP pkt_arp is empty");
 
-	arp_hdr = NET_ARP_HDR(pkt2);
+	arp_hdr = NET_ARP_HDR(pkt_arp);
 
 	if (!net_ipv4_addr_cmp_raw(arp_hdr->dst_ipaddr,
 				   (uint8_t *)&iface->config.ip.ipv4->gw)) {
@@ -476,7 +497,7 @@ ZTEST(arp_fn_tests, test_arp)
 		zassert_true(0, "exiting");
 	}
 
-	net_pkt_unref(pkt2);
+	net_pkt_unref(pkt_arp);
 
 	/* Try to find the same destination again, this should fail as there
 	 * is a pending request in ARP cache.
@@ -488,14 +509,23 @@ ZTEST(arp_fn_tests, test_arp)
 	 */
 	net_pkt_ref(pkt);
 
-	ret = net_arp_prepare(pkt, &dst_far, NULL, &pkt2);
+	ret = net_arp_prepare(pkt, &dst_far, NULL, &pkt_arp);
 
 	zassert_equal(NET_ARP_PKT_REPLACED, ret);
 
-	zassert_not_null(pkt2,
+	zassert_not_null(pkt_arp,
 		"ARP cache is not sending the request again");
 
-	net_pkt_unref(pkt2);
+	net_pkt_unref(pkt_arp);
+
+	ret = net_arp_prepare(pkt, &dst_far, NULL, &pkt_arp);
+
+	zassert_equal(NET_ARP_PKT_REPLACED, ret);
+
+	zassert_not_null(pkt_arp,
+		"ARP cache is not sending the request again");
+
+	net_pkt_unref(pkt_arp);
 
 	/* Try to find the different destination, this should fail too
 	 * as the cache table should be full.
@@ -507,11 +537,11 @@ ZTEST(arp_fn_tests, test_arp)
 	 */
 	net_pkt_ref(pkt);
 
-	ret = net_arp_prepare(pkt, &dst_far2, NULL, &pkt2);
+	ret = net_arp_prepare(pkt, &dst_far2, NULL, &pkt_arp);
 
 	zassert_equal(NET_ARP_PKT_REPLACED, ret);
 
-	zassert_not_null(pkt2,
+	zassert_not_null(pkt_arp,
 		"ARP cache did not send a req");
 
 	/* Restore the original address so that following test case can
@@ -535,13 +565,13 @@ ZTEST(arp_fn_tests, test_arp)
 
 	net_pkt_set_ll_proto_type(pkt, NET_ETH_PTYPE_ARP);
 
-	pkt2 = prepare_arp_reply(iface, pkt, &eth_hwaddr, &eth_hdr);
+	pkt_arp = prepare_arp_reply(iface, pkt, &eth_hwaddr, &eth_hdr);
 
-	zassert_not_null(pkt2, "ARP reply generation failed.");
+	zassert_not_null(pkt_arp, "ARP reply generation failed.");
 
 	/* The pending packet should now be sent */
-	switch (net_arp_input(pkt2,
-			      (struct net_eth_addr *)net_pkt_lladdr_src(pkt2)->addr,
+	switch (net_arp_input(pkt_arp,
+			      (struct net_eth_addr *)net_pkt_lladdr_src(pkt_arp)->addr,
 			      &dst_lladdr)) {
 	case NET_OK:
 	case NET_CONTINUE:
@@ -580,15 +610,15 @@ ZTEST(arp_fn_tests, test_arp)
 
 	net_pkt_set_ll_proto_type(pkt, NET_ETH_PTYPE_ARP);
 
-	pkt2 = prepare_arp_request(iface, pkt, &eth_hwaddr, &eth_hdr);
+	pkt_arp = prepare_arp_request(iface, pkt, &eth_hwaddr, &eth_hdr);
 
 	/**TESTPOINT: Check if ARP request generation failed*/
-	zassert_not_null(pkt2, "ARP request generation failed.");
+	zassert_not_null(pkt_arp, "ARP request generation failed.");
 
 	req_test = true;
 
-	switch (net_arp_input(pkt2,
-			      (struct net_eth_addr *)net_pkt_lladdr_src(pkt2)->addr,
+	switch (net_arp_input(pkt_arp,
+			      (struct net_eth_addr *)net_pkt_lladdr_src(pkt_arp)->addr,
 			      &dst_lladdr)) {
 	case NET_OK:
 	case NET_CONTINUE: