LXR linux/samples/bpf/xdp

   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
 142