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/vxlan_helpers_tests.c

@@ -0,0 +1,193 @@
+// 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
+#define VXLAN_VNI_NEW 0xCAFEBE
+#define UDP_CHECK 0xDEAD
+
+#include "node_config.h"
+#include "lib/common.h"
+#include "lib/vxlan.h"
+
+/* this had to be used instead of the pktgen__push methods since these methods
+ * use layer accounting and will fail when pushing an ipv4 header past its
+ * assumed layer
+ */
+static __always_inline void
+mk_data(const __u8 *buff) {
+	struct ethhdr *eth = (struct ethhdr *)buff;
+
+	memcpy(&eth->h_source, (__u8 *)mac_one, sizeof(mac_three));
+	memcpy(&eth->h_dest, (__u8 *)mac_one, sizeof(mac_four));
+	eth->h_proto = ETH_P_IP;
+
+	struct iphdr *ipv4 = (struct iphdr *)(buff + sizeof(struct ethhdr));
+
+	ipv4->saddr = v4_pod_one;
+	ipv4->daddr = v4_pod_two;
+}
+
+static __always_inline int
+mk_packet(struct __ctx_buff *ctx) {
+	struct pktgen builder;
+	struct udphdr *l4;
+	struct vxlanhdr *vx;
+	/* data is encap'd ipv4 packet, we don't care about l4 */
+	__u8 encap_data[sizeof(struct ethhdr) + sizeof(struct iphdr)];
+	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;
+
+	l4->check = UDP_CHECK;
+
+	vx = pktgen__push_default_vxlanhdr(&builder);
+	if (!vx)
+		return TEST_ERROR;
+
+	vx->vx_vni = bpf_htonl(VXLAN_VNI << 8);
+
+	mk_data(encap_data);
+
+	data = pktgen__push_data(&builder, encap_data, sizeof(encap_data));
+	if (!data)
+		return TEST_ERROR;
+
+	pktgen__finish(&builder);
+
+	return 0;
+}
+
+PKTGEN("tc", "vxlan_skb_is_vxlan_v4_success")
+static __always_inline int
+pktgen_vxlan_mock_check1(struct __ctx_buff *ctx) {
+	return mk_packet(ctx);
+}
+
+CHECK("tc", "vxlan_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(vxlan_skb_is_vxlan_v4(data, data_end, ipv4, TUNNEL_PORT));
+
+	test_finish();
+}
+
+PKTGEN("tc", "vxlan_skb_is_vxlan_v4_failure")
+static __always_inline int
+pktgen_vxlan_mock_check2(struct __ctx_buff *ctx) {
+	return mk_packet(ctx);
+}
+
+CHECK("tc", "vxlan_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(!vxlan_skb_is_vxlan_v4(data, data_end, ipv4, TUNNEL_PORT_BAD));
+
+	test_finish();
+}
+
+PKTGEN("tc", "vxlan_get_vni_success")
+static __always_inline int
+pktgen_vxlan_mock_check3(struct __ctx_buff *ctx) {
+	return mk_packet(ctx);
+}
+
+CHECK("tc", "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(vxlan_get_vni(data, data_end, ipv4) == VXLAN_VNI);
+
+	test_finish();
+}
+
+PKTGEN("tc", "vxlan_get_inner_ipv4_success")
+static __always_inline int
+pktgen_vxlan_mock_check4(struct __ctx_buff *ctx) {
+	return mk_packet(ctx);
+}
+
+CHECK("tc", "vxlan_get_inner_ipv4_success")
+int check4(struct __ctx_buff *ctx)
+{
+	test_init();
+
+	void *data, *data_end = NULL;
+	struct iphdr *ipv4 = NULL;
+	struct iphdr *inner_ipv4 = NULL;
+
+	assert(revalidate_data(ctx, &data, &data_end, &ipv4));
+	assert(vxlan_get_inner_ipv4(data, data_end, ipv4, &inner_ipv4));
+
+	assert(inner_ipv4->saddr == v4_pod_one);
+	assert(inner_ipv4->daddr == v4_pod_two);
+
+	test_finish();
+}
+
+PKTGEN("tc", "vxlan_rewrite_vni_success")
+static __always_inline int
+pktgen_vxlan_mock_check5(struct __ctx_buff *ctx) {
+	return mk_packet(ctx);
+}
+
+CHECK("tc", "vxlan_rewrite_vni_success")
+int check5(struct __ctx_buff *ctx)
+{
+	test_init();
+
+	void *data, *data_end = NULL;
+	struct iphdr *ipv4 = NULL;
+	struct udphdr *udp = NULL;
+	__u32 vni = 0;
+
+	assert(revalidate_data(ctx, &data, &data_end, &ipv4));
+
+	assert(vxlan_rewrite_vni(ctx, data, data_end, ipv4,
+				 VXLAN_VNI_NEW));
+
+	/* packet data was touched so revalidate */
+	assert(revalidate_data(ctx, &data, &data_end, &ipv4));
+
+	vni = vxlan_get_vni(data, data_end, ipv4);
+	assert(vni == VXLAN_VNI_NEW);
+
+	/* assert udp checksum was updated */
+	udp = (struct udphdr *)(data + sizeof(struct ethhdr) + (ipv4->ihl * 4));
+	assert(udp->check != UDP_CHECK);
+
+	test_finish();
+}