bpf: test: use different backend port for hairpin test

[ upstream commit f0b44c0 ]

The test currently assumes SVC_PORT == BACKEND_PORT. This limits the test
coverage (we're not testing that L4 NAT works properly), and isn't strictly
required in real world scenarios.

Change the test so that the backend uses a different port.

Signed-off-by: Julian Wiedmann <jwi@isovalent.com>

bpf/tests/pktgen.h

@@ -79,9 +79,13 @@ static volatile const __u8 v6_node_three[] = {0xfd, 0x07, 0, 0, 0, 0, 0, 0,
 					   0, 0, 0, 0, 0, 0, 0, 3};
 
 /* Source port to be used by a client */
-#define tcp_src_one	__bpf_htons(22334)
-#define tcp_src_two	__bpf_htons(33445)
-#define tcp_src_three	__bpf_htons(44556)
+#define tcp_src_one	__bpf_htons(22330)
+#define tcp_src_two	__bpf_htons(33440)
+#define tcp_src_three	__bpf_htons(44550)
+
+#define tcp_dst_one	__bpf_htons(22331)
+#define tcp_dst_two	__bpf_htons(33441)
+#define tcp_dst_three	__bpf_htons(44551)
 
 #define tcp_svc_one	__bpf_htons(80)
 #define tcp_svc_two	__bpf_htons(443)

bpf/tests/tc_nodeport_test.c

@@ -150,7 +150,7 @@ int hairpin_flow_forward_setup(struct __ctx_buff *ctx)
 	 * packet to.
 	 */
 	backend.address = v4_pod_one;
-	backend.port = tcp_svc_one;
+	backend.port = tcp_dst_one;
 	backend.proto = IPPROTO_TCP;
 	backend.flags = 0;
 	map_update_elem(&LB4_BACKEND_MAP, &lb_svc_value.backend_id, &backend, BPF_ANY);
@@ -213,7 +213,7 @@ int hairpin_flow_forward_check(__maybe_unused const struct __ctx_buff *ctx)
 	if (l4->source != tcp_src_one)
 		test_fatal("src TCP port was changed");
 
-	if (l4->dest != tcp_svc_one)
+	if (l4->dest != tcp_dst_one)
 		test_fatal("dst TCP port incorrect");
 
 	struct ipv4_ct_tuple tuple = {};
@@ -240,7 +240,7 @@ int hairpin_flow_forward_check(__maybe_unused const struct __ctx_buff *ctx)
 	tuple.saddr = IPV4_LOOPBACK;
 	tuple.sport = tcp_src_one;
 	tuple.daddr = v4_pod_one;
-	tuple.dport = tcp_svc_one;
+	tuple.dport = tcp_dst_one;
 
 	/* Addrs are stored in reverse order: */
 	ipv4_ct_tuple_swap_addrs(&tuple);
@@ -289,7 +289,7 @@ int hairpin_flow_forward_ingress_pktgen(struct __ctx_buff *ctx)
 		return TEST_ERROR;
 
 	l4->source = tcp_src_one;
-	l4->dest = tcp_svc_one;
+	l4->dest = tcp_dst_one;
 
 	data = pktgen__push_data(&builder, default_data, sizeof(default_data));
 
@@ -352,7 +352,7 @@ int hairpin_flow_forward_ingress_check(__maybe_unused const struct __ctx_buff *c
 	if (l4->source != tcp_src_one)
 		test_fatal("src TCP port changed");
 
-	if (l4->dest != tcp_svc_one)
+	if (l4->dest != tcp_dst_one)
 		test_fatal("dst TCP port changed");
 
 	struct ipv4_ct_tuple tuple = {};
@@ -364,7 +364,7 @@ int hairpin_flow_forward_ingress_check(__maybe_unused const struct __ctx_buff *c
 	tuple.saddr = IPV4_LOOPBACK;
 	tuple.sport = tcp_src_one;
 	tuple.daddr = v4_pod_one;
-	tuple.dport = tcp_svc_one;
+	tuple.dport = tcp_dst_one;
 
 	/* Addrs are stored in reverse order: */
 	ipv4_ct_tuple_swap_addrs(&tuple);
@@ -411,11 +411,10 @@ int hairpin_flow_reverse_pktgen(struct __ctx_buff *ctx)
 
 	/* Push TCP header */
 	l4 = pktgen__push_default_tcphdr(&builder);
-
 	if (!l4)
 		return TEST_ERROR;
 
-	l4->source = tcp_svc_one;
+	l4->source = tcp_dst_one;
 	l4->dest = tcp_src_one;
 	l4->ack = 1;