LXR iproute2/include/bpf

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef __BPF_API__
   3#define __BPF_API__
   4
   5/* Note:
   6 *
   7 * This file can be included into eBPF kernel programs. It contains
   8 * a couple of useful helper functions, map/section ABI (bpf_elf.h),
   9 * misc macros and some eBPF specific LLVM built-ins.
  10 */
  11
  12#include <stdint.h>
  13
  14#include <linux/pkt_cls.h>
  15#include <linux/bpf.h>
  16#include <linux/filter.h>
  17
  18#include <asm/byteorder.h>
  19
  20#include "bpf_elf.h"
  21
  22/** libbpf pin type. */
  23enum libbpf_pin_type {
  24        LIBBPF_PIN_NONE,
  25        /* PIN_BY_NAME: pin maps by name (in /sys/fs/bpf by default) */
  26        LIBBPF_PIN_BY_NAME,
  27};
  28
  29/** Type helper macros. */
  30
  31#define __uint(name, val) int (*name)[val]
  32#define __type(name, val) typeof(val) *name
  33#define __array(name, val) typeof(val) *name[]
  34
  35/** Misc macros. */
  36
  37#ifndef __stringify
  38# define __stringify(X)         #X
  39#endif
  40
  41#ifndef __maybe_unused
  42# define __maybe_unused         __attribute__((__unused__))
  43#endif
  44
  45#ifndef offsetof
  46# define offsetof(TYPE, MEMBER) __builtin_offsetof(TYPE, MEMBER)
  47#endif
  48
  49#ifndef likely
  50# define likely(X)              __builtin_expect(!!(X), 1)
  51#endif
  52
  53#ifndef unlikely
  54# define unlikely(X)            __builtin_expect(!!(X), 0)
  55#endif
  56
  57#ifndef htons
  58# define htons(X)               __constant_htons((X))
  59#endif
  60
  61#ifndef ntohs
  62# define ntohs(X)               __constant_ntohs((X))
  63#endif
  64
  65#ifndef htonl
  66# define htonl(X)               __constant_htonl((X))
  67#endif
  68
  69#ifndef ntohl
  70# define ntohl(X)               __constant_ntohl((X))
  71#endif
  72
  73#ifndef __inline__
  74# define __inline__             __attribute__((always_inline))
  75#endif
  76
  77/** Section helper macros. */
  78
  79#ifndef __section
  80# define __section(NAME)                                                \
  81        __attribute__((section(NAME), used))
  82#endif
  83
  84#ifndef __section_tail
  85# define __section_tail(ID, KEY)                                        \
  86        __section(__stringify(ID) "/" __stringify(KEY))
  87#endif
  88
  89#ifndef __section_xdp_entry
  90# define __section_xdp_entry                                            \
  91        __section(ELF_SECTION_PROG)
  92#endif
  93
  94#ifndef __section_cls_entry
  95# define __section_cls_entry                                            \
  96        __section(ELF_SECTION_CLASSIFIER)
  97#endif
  98
  99#ifndef __section_act_entry
 100# define __section_act_entry                                            \
 101        __section(ELF_SECTION_ACTION)
 102#endif
 103
 104#ifndef __section_lwt_entry
 105# define __section_lwt_entry                                            \
 106        __section(ELF_SECTION_PROG)
 107#endif
 108
 109#ifndef __section_license
 110# define __section_license                                              \
 111        __section(ELF_SECTION_LICENSE)
 112#endif
 113
 114#ifndef __section_maps
 115# define __section_maps                                                 \
 116        __section(ELF_SECTION_MAPS)
 117#endif
 118
 119/** Declaration helper macros. */
 120
 121#ifndef BPF_LICENSE
 122# define BPF_LICENSE(NAME)                                              \
 123        char ____license[] __section_license = NAME
 124#endif
 125
 126/** Classifier helper */
 127
 128#ifndef BPF_H_DEFAULT
 129# define BPF_H_DEFAULT  -1
 130#endif
 131
 132/** BPF helper functions for tc. Individual flags are in linux/bpf.h */
 133
 134#ifndef __BPF_FUNC
 135# define __BPF_FUNC(NAME, ...)                                          \
 136        (* NAME)(__VA_ARGS__) __maybe_unused
 137#endif
 138
 139#ifndef BPF_FUNC
 140# define BPF_FUNC(NAME, ...)                                            \
 141        __BPF_FUNC(NAME, __VA_ARGS__) = (void *) BPF_FUNC_##NAME
 142#endif
 143
 144/* Map access/manipulation */
 145static void *BPF_FUNC(map_lookup_elem, void *map, const void *key);
 146static int BPF_FUNC(map_update_elem, void *map, const void *key,
 147                    const void *value, uint32_t flags);
 148static int BPF_FUNC(map_delete_elem, void *map, const void *key);
 149
 150/* Time access */
 151static uint64_t BPF_FUNC(ktime_get_ns);
 152
 153/* Debugging */
 154
 155/* FIXME: __attribute__ ((format(printf, 1, 3))) not possible unless
 156 * llvm bug https://llvm.org/bugs/show_bug.cgi?id=26243 gets resolved.
 157 * It would require ____fmt to be made const, which generates a reloc
 158 * entry (non-map).
 159 */
 160static void BPF_FUNC(trace_printk, const char *fmt, int fmt_size, ...);
 161
 162#ifndef printt
 163# define printt(fmt, ...)                                               \
 164        ({                                                              \
 165                char ____fmt[] = fmt;                                   \
 166                trace_printk(____fmt, sizeof(____fmt), ##__VA_ARGS__);  \
 167        })
 168#endif
 169
 170/* Random numbers */
 171static uint32_t BPF_FUNC(get_prandom_u32);
 172
 173/* Tail calls */
 174static void BPF_FUNC(tail_call, struct __sk_buff *skb, void *map,
 175                     uint32_t index);
 176
 177/* System helpers */
 178static uint32_t BPF_FUNC(get_smp_processor_id);
 179static uint32_t BPF_FUNC(get_numa_node_id);
 180
 181/* Packet misc meta data */
 182static uint32_t BPF_FUNC(get_cgroup_classid, struct __sk_buff *skb);
 183static int BPF_FUNC(skb_under_cgroup, void *map, uint32_t index);
 184
 185static uint32_t BPF_FUNC(get_route_realm, struct __sk_buff *skb);
 186static uint32_t BPF_FUNC(get_hash_recalc, struct __sk_buff *skb);
 187static uint32_t BPF_FUNC(set_hash_invalid, struct __sk_buff *skb);
 188
 189/* Packet redirection */
 190static int BPF_FUNC(redirect, int ifindex, uint32_t flags);
 191static int BPF_FUNC(clone_redirect, struct __sk_buff *skb, int ifindex,
 192                    uint32_t flags);
 193
 194/* Packet manipulation */
 195static int BPF_FUNC(skb_load_bytes, struct __sk_buff *skb, uint32_t off,
 196                    void *to, uint32_t len);
 197static int BPF_FUNC(skb_store_bytes, struct __sk_buff *skb, uint32_t off,
 198                    const void *from, uint32_t len, uint32_t flags);
 199
 200static int BPF_FUNC(l3_csum_replace, struct __sk_buff *skb, uint32_t off,
 201                    uint32_t from, uint32_t to, uint32_t flags);
 202static int BPF_FUNC(l4_csum_replace, struct __sk_buff *skb, uint32_t off,
 203                    uint32_t from, uint32_t to, uint32_t flags);
 204static int BPF_FUNC(csum_diff, const void *from, uint32_t from_size,
 205                    const void *to, uint32_t to_size, uint32_t seed);
 206static int BPF_FUNC(csum_update, struct __sk_buff *skb, uint32_t wsum);
 207
 208static int BPF_FUNC(skb_change_type, struct __sk_buff *skb, uint32_t type);
 209static int BPF_FUNC(skb_change_proto, struct __sk_buff *skb, uint32_t proto,
 210                    uint32_t flags);
 211static int BPF_FUNC(skb_change_tail, struct __sk_buff *skb, uint32_t nlen,
 212                    uint32_t flags);
 213
 214static int BPF_FUNC(skb_pull_data, struct __sk_buff *skb, uint32_t len);
 215
 216/* Event notification */
 217static int __BPF_FUNC(skb_event_output, struct __sk_buff *skb, void *map,
 218                      uint64_t index, const void *data, uint32_t size) =
 219                      (void *) BPF_FUNC_perf_event_output;
 220
 221/* Packet vlan encap/decap */
 222static int BPF_FUNC(skb_vlan_push, struct __sk_buff *skb, uint16_t proto,
 223                    uint16_t vlan_tci);
 224static int BPF_FUNC(skb_vlan_pop, struct __sk_buff *skb);
 225
 226/* Packet tunnel encap/decap */
 227static int BPF_FUNC(skb_get_tunnel_key, struct __sk_buff *skb,
 228                    struct bpf_tunnel_key *to, uint32_t size, uint32_t flags);
 229static int BPF_FUNC(skb_set_tunnel_key, struct __sk_buff *skb,
 230                    const struct bpf_tunnel_key *from, uint32_t size,
 231                    uint32_t flags);
 232
 233static int BPF_FUNC(skb_get_tunnel_opt, struct __sk_buff *skb,
 234                    void *to, uint32_t size);
 235static int BPF_FUNC(skb_set_tunnel_opt, struct __sk_buff *skb,
 236                    const void *from, uint32_t size);
 237
 238/** LLVM built-ins, mem*() routines work for constant size */
 239
 240#ifndef lock_xadd
 241# define lock_xadd(ptr, val)    ((void) __sync_fetch_and_add(ptr, val))
 242#endif
 243
 244#ifndef memset
 245# define memset(s, c, n)        __builtin_memset((s), (c), (n))
 246#endif
 247
 248#ifndef memcpy
 249# define memcpy(d, s, n)        __builtin_memcpy((d), (s), (n))
 250#endif
 251
 252#ifndef memmove
 253# define memmove(d, s, n)       __builtin_memmove((d), (s), (n))
 254#endif
 255
 256/* FIXME: __builtin_memcmp() is not yet fully useable unless llvm bug
 257 * https://llvm.org/bugs/show_bug.cgi?id=26218 gets resolved. Also
 258 * this one would generate a reloc entry (non-map), otherwise.
 259 */
 260#if 0
 261#ifndef memcmp
 262# define memcmp(a, b, n)        __builtin_memcmp((a), (b), (n))
 263#endif
 264#endif
 265
 266unsigned long long load_byte(void *skb, unsigned long long off)
 267        asm ("llvm.bpf.load.byte");
 268
 269unsigned long long load_half(void *skb, unsigned long long off)
 270        asm ("llvm.bpf.load.half");
 271
 272unsigned long long load_word(void *skb, unsigned long long off)
 273        asm ("llvm.bpf.load.word");
 274
 275#endif /* __BPF_API__ */
 276