/* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
/* Copyright 2019, 2020 Cloudflare */
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <string.h>
#include <linux/if_ether.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/udp.h>
/* offsetof() is used in static asserts, and the libbpf-redefined CO-RE
* friendly version breaks compilation for older clang versions <= 15
* when invoked in a static assert. Restore original here.
*/
#ifdef offsetof
#undef offsetof
#define offsetof(type, member) __builtin_offsetof(type, member)
#endif
struct gre_base_hdr {
uint16_t flags;
uint16_t protocol;
} __attribute__((packed));
struct guehdr {
#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
uint8_t hlen : 5, control : 1, variant : 2;
#else
uint8_t variant : 2, control : 1, hlen : 5;
#endif
uint8_t proto_ctype;
uint16_t flags;
};
struct unigue {
#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
uint8_t _r : 2, last_hop_gre : 1, forward_syn : 1, version : 4;
#else
uint8_t version : 4, forward_syn : 1, last_hop_gre : 1, _r : 2;
#endif
uint8_t reserved;
uint8_t next_hop;
uint8_t hop_count;
// Next hops go here
} __attribute__((packed));
typedef struct {
struct ethhdr eth;
struct iphdr ip;
struct gre_base_hdr gre;
} __attribute__((packed)) encap_gre_t;
typedef struct {
struct ethhdr eth;
struct iphdr ip;
struct udphdr udp;
struct guehdr gue;
struct unigue unigue;
} __attribute__((packed)) encap_headers_t;