1 files changed, 85 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/test_lwt_ip_encap.c b/tools/testing/selftests/bpf/progs/test_lwt_ip_encap.c
new file mode 100644
index 000000000000..c957d6dfe6d7
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_lwt_ip_encap.c
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stddef.h>
+#include <string.h>
+#include <linux/bpf.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include "bpf_helpers.h"
+#include "bpf_endian.h"
+
+struct grehdr {
+	__be16 flags;
+	__be16 protocol;
+};
+
+SEC("encap_gre")
+int bpf_lwt_encap_gre(struct __sk_buff *skb)
+{
+	struct encap_hdr {
+		struct iphdr iph;
+		struct grehdr greh;
+	} hdr;
+	int err;
+
+	memset(&hdr, 0, sizeof(struct encap_hdr));
+
+	hdr.iph.ihl = 5;
+	hdr.iph.version = 4;
+	hdr.iph.ttl = 0x40;
+	hdr.iph.protocol = 47;  /* IPPROTO_GRE */
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+	hdr.iph.saddr = 0x640110ac;  /* 172.16.1.100 */
+	hdr.iph.daddr = 0x641010ac;  /* 172.16.16.100 */
+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+	hdr.iph.saddr = 0xac100164;  /* 172.16.1.100 */
+	hdr.iph.daddr = 0xac101064;  /* 172.16.16.100 */
+#else
+#error "Fix your compiler's __BYTE_ORDER__?!"
+#endif
+	hdr.iph.tot_len = bpf_htons(skb->len + sizeof(struct encap_hdr));
+
+	hdr.greh.protocol = skb->protocol;
+
+	err = bpf_lwt_push_encap(skb, BPF_LWT_ENCAP_IP, &hdr,
+				 sizeof(struct encap_hdr));
+	if (err)
+		return BPF_DROP;
+
+	return BPF_LWT_REROUTE;
+}
+
+SEC("encap_gre6")
+int bpf_lwt_encap_gre6(struct __sk_buff *skb)
+{
+	struct encap_hdr {
+		struct ipv6hdr ip6hdr;
+		struct grehdr greh;
+	} hdr;
+	int err;
+
+	memset(&hdr, 0, sizeof(struct encap_hdr));
+
+	hdr.ip6hdr.version = 6;
+	hdr.ip6hdr.payload_len = bpf_htons(skb->len + sizeof(struct grehdr));
+	hdr.ip6hdr.nexthdr = 47;  /* IPPROTO_GRE */
+	hdr.ip6hdr.hop_limit = 0x40;
+	/* fb01::1 */
+	hdr.ip6hdr.saddr.s6_addr[0] = 0xfb;
+	hdr.ip6hdr.saddr.s6_addr[1] = 1;
+	hdr.ip6hdr.saddr.s6_addr[15] = 1;
+	/* fb10::1 */
+	hdr.ip6hdr.daddr.s6_addr[0] = 0xfb;
+	hdr.ip6hdr.daddr.s6_addr[1] = 0x10;
+	hdr.ip6hdr.daddr.s6_addr[15] = 1;
+
+	hdr.greh.protocol = skb->protocol;
+
+	err = bpf_lwt_push_encap(skb, BPF_LWT_ENCAP_IP, &hdr,
+				 sizeof(struct encap_hdr));
+	if (err)
+		return BPF_DROP;
+
+	return BPF_LWT_REROUTE;
+}
+
+char _license[] SEC("license") = "GPL";