1// SPDX-License-Identifier: GPL-2.0
  2#ifndef _XDP_SAMPLE_BPF_H
  3#define _XDP_SAMPLE_BPF_H
  4
  5#include "vmlinux.h"
  6#include <bpf/bpf_tracing.h>
  7#include <bpf/bpf_core_read.h>
  8#include <bpf/bpf_helpers.h>
  9
 10#include "xdp_sample_shared.h"
 11
 12#define ETH_ALEN 6
 13#define ETH_P_802_3_MIN 0x0600
 14#define ETH_P_8021Q 0x8100
 15#define ETH_P_8021AD 0x88A8
 16#define ETH_P_IP 0x0800
 17#define ETH_P_IPV6 0x86DD
 18#define ETH_P_ARP 0x0806
 19#define IPPROTO_ICMPV6 58
 20
 21#define EINVAL 22
 22#define ENETDOWN 100
 23#define EMSGSIZE 90
 24#define EOPNOTSUPP 95
 25#define ENOSPC 28
 26
 27typedef struct {
 28	__uint(type, BPF_MAP_TYPE_ARRAY);
 29	__uint(map_flags, BPF_F_MMAPABLE);
 30	__type(key, unsigned int);
 31	__type(value, struct datarec);
 32} array_map;
 33
 34extern array_map rx_cnt;
 35extern const volatile int nr_cpus;
 36
 37enum {
 38	XDP_REDIRECT_SUCCESS = 0,
 39	XDP_REDIRECT_ERROR = 1
 40};
 41
 42static __always_inline void swap_src_dst_mac(void *data)
 43{
 44	unsigned short *p = data;
 45	unsigned short dst[3];
 46
 47	dst[0] = p[0];
 48	dst[1] = p[1];
 49	dst[2] = p[2];
 50	p[0] = p[3];
 51	p[1] = p[4];
 52	p[2] = p[5];
 53	p[3] = dst[0];
 54	p[4] = dst[1];
 55	p[5] = dst[2];
 56}
 57
 58#if defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && \
 59	__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 60#define bpf_ntohs(x)		__builtin_bswap16(x)
 61#define bpf_htons(x)		__builtin_bswap16(x)
 62#elif defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && \
 63	__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
 64#define bpf_ntohs(x)		(x)
 65#define bpf_htons(x)		(x)
 66#else
 67# error "Endianness detection needs to be set up for your compiler?!"
 68#endif
 69
 70/*
 71 * Note: including linux/compiler.h or linux/kernel.h for the macros below
 72 * conflicts with vmlinux.h include in BPF files, so we define them here.
 73 *
 74 * Following functions are taken from kernel sources and
 75 * break aliasing rules in their original form.
 76 *
 77 * While kernel is compiled with -fno-strict-aliasing,
 78 * perf uses -Wstrict-aliasing=3 which makes build fail
 79 * under gcc 4.4.
 80 *
 81 * Using extra __may_alias__ type to allow aliasing
 82 * in this case.
 83 */
 84typedef __u8  __attribute__((__may_alias__))  __u8_alias_t;
 85typedef __u16 __attribute__((__may_alias__)) __u16_alias_t;
 86typedef __u32 __attribute__((__may_alias__)) __u32_alias_t;
 87typedef __u64 __attribute__((__may_alias__)) __u64_alias_t;
 88
 89static __always_inline void __read_once_size(const volatile void *p, void *res, int size)
 90{
 91	switch (size) {
 92	case 1: *(__u8_alias_t  *) res = *(volatile __u8_alias_t  *) p; break;
 93	case 2: *(__u16_alias_t *) res = *(volatile __u16_alias_t *) p; break;
 94	case 4: *(__u32_alias_t *) res = *(volatile __u32_alias_t *) p; break;
 95	case 8: *(__u64_alias_t *) res = *(volatile __u64_alias_t *) p; break;
 96	default:
 97		asm volatile ("" : : : "memory");
 98		__builtin_memcpy((void *)res, (const void *)p, size);
 99		asm volatile ("" : : : "memory");
100	}
101}
102
103static __always_inline void __write_once_size(volatile void *p, void *res, int size)
104{
105	switch (size) {
106	case 1: *(volatile  __u8_alias_t *) p = *(__u8_alias_t  *) res; break;
107	case 2: *(volatile __u16_alias_t *) p = *(__u16_alias_t *) res; break;
108	case 4: *(volatile __u32_alias_t *) p = *(__u32_alias_t *) res; break;
109	case 8: *(volatile __u64_alias_t *) p = *(__u64_alias_t *) res; break;
110	default:
111		asm volatile ("" : : : "memory");
112		__builtin_memcpy((void *)p, (const void *)res, size);
113		asm volatile ("" : : : "memory");
114	}
115}
116
117#define READ_ONCE(x)					\
118({							\
119	union { typeof(x) __val; char __c[1]; } __u =	\
120		{ .__c = { 0 } };			\
121	__read_once_size(&(x), __u.__c, sizeof(x));	\
122	__u.__val;					\
123})
124
125#define WRITE_ONCE(x, val)				\
126({							\
127	union { typeof(x) __val; char __c[1]; } __u =	\
128		{ .__val = (val) }; 			\
129	__write_once_size(&(x), __u.__c, sizeof(x));	\
130	__u.__val;					\
131})
132
133/* Add a value using relaxed read and relaxed write. Less expensive than
134 * fetch_add when there is no write concurrency.
135 */
136#define NO_TEAR_ADD(x, val) WRITE_ONCE((x), READ_ONCE(x) + (val))
137#define NO_TEAR_INC(x) NO_TEAR_ADD((x), 1)
138
139#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
140
141#endif