bpf,test: add tests for vxlan helper functions

Add unit tests for new vxlan helper functions in tunnel.h

Signed-off-by: Louis DeLosSantos <louis.delos@isovalent.com>

bpf/tests/tunnel_vxlan_helpers_tests.c

@@ -0,0 +1,110 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+/* Copyright Authors of Cilium */
+
+#include "common.h"
+#include "bpf/ctx/skb.h"
+#include "pktgen.h"
+
+#define TUNNEL_PROTOCOL TUNNEL_PROTOCOL_VXLAN
+#define TUNNEL_PORT 8472
+#define TUNNEL_PORT_BAD 0
+#define VXLAN_VNI 0xDEADBE
+
+#include "node_config.h"
+#include "lib/common.h"
+
+static __always_inline int
+mk_packet(struct __ctx_buff *ctx) {
+	struct pktgen builder;
+	struct udphdr *l4;
+	struct vxlanhdr *vx;
+	void *data;
+
+	pktgen__init(&builder, ctx);
+
+	l4 = pktgen__push_ipv4_udp_packet(&builder,
+					  (__u8 *)mac_one,
+					  (__u8 *)mac_two,
+					  v4_node_one,
+					  v4_node_two,
+					  666,
+					  bpf_htons(TUNNEL_PORT));
+	if (!l4)
+		return TEST_ERROR;
+
+	vx = pktgen__push_default_vxlanhdr(&builder);
+	if (!vx)
+		return TEST_ERROR;
+
+	vx->vx_vni = bpf_htonl(VXLAN_VNI << 8);
+
+	/* we won't sniff into the encap'd packet, so just use the default */
+	data = pktgen__push_data(&builder, default_data, sizeof(default_data));
+	if (!data)
+		return TEST_ERROR;
+
+	pktgen__finish(&builder);
+
+	return 0;
+}
+
+PKTGEN("tc", "tunnel_skb_is_vxlan_v4_success")
+static __always_inline int
+pktgen_vxlan_mock_check1(struct __ctx_buff *ctx) {
+	return mk_packet(ctx);
+}
+
+CHECK("tc", "tunnel_skb_is_vxlan_v4_success")
+int check1(struct __ctx_buff *ctx)
+{
+	test_init();
+
+	void *data, *data_end = NULL;
+	struct iphdr *ipv4 = NULL;
+
+	assert(revalidate_data(ctx, &data, &data_end, &ipv4));
+	assert(tunnel_skb_is_vxlan_v4(data, data_end, ipv4, TUNNEL_PORT));
+
+	test_finish();
+}
+
+PKTGEN("tc", "tunnel_skb_is_vxlan_v4_failure")
+static __always_inline int
+pktgen_vxlan_mock_check2(struct __ctx_buff *ctx) {
+	return mk_packet(ctx);
+}
+
+CHECK("tc", "tunnel_skb_is_vxlan_v4_failure")
+int check2(struct __ctx_buff *ctx)
+{
+	test_init();
+
+	void *data, *data_end = NULL;
+	struct iphdr *ipv4 = NULL;
+
+	assert(revalidate_data(ctx, &data, &data_end, &ipv4));
+	assert(!tunnel_skb_is_vxlan_v4(data, data_end, ipv4, TUNNEL_PORT_BAD));
+
+	test_finish();
+}
+
+PKTGEN("tc", "tunnel_vxlan_get_vni_success")
+static __always_inline int
+pktgen_vxlan_mock_check3(struct __ctx_buff *ctx) {
+	return mk_packet(ctx);
+}
+
+CHECK("tc", "tunnel_vxlan_get_vni_success")
+int check3(struct __ctx_buff *ctx)
+{
+	test_init();
+
+	void *data, *data_end = NULL;
+	struct iphdr *ipv4 = NULL;
+
+	assert(revalidate_data(ctx, &data, &data_end, &ipv4));
+	assert(tunnel_vxlan_get_vni(data, data_end, ipv4) == VXLAN_VNI);
+
+	test_finish();
+}
+