1/* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
2/* Copyright 2019, 2020 Cloudflare */
3
4#include <stdbool.h>
5#include <stddef.h>
6#include <stdint.h>
7#include <string.h>
8
9#include <linux/if_ether.h>
10#include <linux/in.h>
11#include <linux/ip.h>
12#include <linux/ipv6.h>
13#include <linux/udp.h>
14
15/* offsetof() is used in static asserts, and the libbpf-redefined CO-RE
16 * friendly version breaks compilation for older clang versions <= 15
17 * when invoked in a static assert.  Restore original here.
18 */
19#ifdef offsetof
20#undef offsetof
21#define offsetof(type, member) __builtin_offsetof(type, member)
22#endif
23
24struct gre_base_hdr {
25	uint16_t flags;
26	uint16_t protocol;
27} __attribute__((packed));
28
29struct guehdr {
30#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
31	uint8_t hlen : 5, control : 1, variant : 2;
32#else
33	uint8_t variant : 2, control : 1, hlen : 5;
34#endif
35	uint8_t proto_ctype;
36	uint16_t flags;
37};
38
39struct unigue {
40#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
41	uint8_t _r : 2, last_hop_gre : 1, forward_syn : 1, version : 4;
42#else
43	uint8_t version : 4, forward_syn : 1, last_hop_gre : 1, _r : 2;
44#endif
45	uint8_t reserved;
46	uint8_t next_hop;
47	uint8_t hop_count;
48	// Next hops go here
49} __attribute__((packed));
50
51typedef struct {
52	struct ethhdr eth;
53	struct iphdr ip;
54	struct gre_base_hdr gre;
55} __attribute__((packed)) encap_gre_t;
56
57typedef struct {
58	struct ethhdr eth;
59	struct iphdr ip;
60	struct udphdr udp;
61	struct guehdr gue;
62	struct unigue unigue;
63} __attribute__((packed)) encap_headers_t;
64