samples/bpf/libbpf.h

   1 /* eBPF mini library */
   2 #ifndef __LIBBPF_H
   3 #define __LIBBPF_H
   4
   5 struct bpf_insn;
   6
   7 int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size,
   8                    int max_entries, int map_flags);
   9 int bpf_update_elem(int fd, void *key, void *value, unsigned long long flags);
  10 int bpf_lookup_elem(int fd, void *key, void *value);
  11 int bpf_delete_elem(int fd, void *key);
  12 int bpf_get_next_key(int fd, void *key, void *next_key);
  13
  14 int bpf_prog_load(enum bpf_prog_type prog_type,
  15                   const struct bpf_insn *insns, int insn_len,
  16                   const char *license, int kern_version);
  17
  18 int bpf_prog_attach(int prog_fd, int attachable_fd, enum bpf_attach_type type);
  19 int bpf_prog_detach(int attachable_fd, enum bpf_attach_type type);
  20
  21 int bpf_obj_pin(int fd, const char *pathname);
  22 int bpf_obj_get(const char *pathname);
  23
  24 #define LOG_BUF_SIZE (256 * 1024)
  25 extern char bpf_log_buf[LOG_BUF_SIZE];
  26
  27 /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
  28
  29 #define BPF_ALU64_REG(OP, DST, SRC)                             \
  30         ((struct bpf_insn) {                                    \
  31                 .code  = BPF_ALU64 | BPF_OP(OP) | BPF_X,        \
  32                 .dst_reg = DST,                                 \
  33                 .src_reg = SRC,                                 \
  34                 .off   = 0,                                     \
  35                 .imm   = 0 })
  36
  37 #define BPF_ALU32_REG(OP, DST, SRC)                             \
  38         ((struct bpf_insn) {                                    \
  39                 .code  = BPF_ALU | BPF_OP(OP) | BPF_X,          \
  40                 .dst_reg = DST,                                 \
  41                 .src_reg = SRC,                                 \
  42                 .off   = 0,                                     \
  43                 .imm   = 0 })
  44
  45 /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
  46
  47 #define BPF_ALU64_IMM(OP, DST, IMM)                             \
  48         ((struct bpf_insn) {                                    \
  49                 .code  = BPF_ALU64 | BPF_OP(OP) | BPF_K,        \
  50                 .dst_reg = DST,                                 \
  51                 .src_reg = 0,                                   \
  52                 .off   = 0,                                     \
  53                 .imm   = IMM })
  54
  55 #define BPF_ALU32_IMM(OP, DST, IMM)                             \
  56         ((struct bpf_insn) {                                    \
  57                 .code  = BPF_ALU | BPF_OP(OP) | BPF_K,          \
  58                 .dst_reg = DST,                                 \
  59                 .src_reg = 0,                                   \
  60                 .off   = 0,                                     \
  61                 .imm   = IMM })
  62
  63 /* Short form of mov, dst_reg = src_reg */
  64
  65 #define BPF_MOV64_REG(DST, SRC)                                 \
  66         ((struct bpf_insn) {                                    \
  67                 .code  = BPF_ALU64 | BPF_MOV | BPF_X,           \
  68                 .dst_reg = DST,                                 \
  69                 .src_reg = SRC,                                 \
  70                 .off   = 0,                                     \
  71                 .imm   = 0 })
  72
  73 #define BPF_MOV32_REG(DST, SRC)                                 \
  74         ((struct bpf_insn) {                                    \
  75                 .code  = BPF_ALU | BPF_MOV | BPF_X,             \
  76                 .dst_reg = DST,                                 \
  77                 .src_reg = SRC,                                 \
  78                 .off   = 0,                                     \
  79                 .imm   = 0 })
  80
  81 /* Short form of mov, dst_reg = imm32 */
  82
  83 #define BPF_MOV64_IMM(DST, IMM)                                 \
  84         ((struct bpf_insn) {                                    \
  85                 .code  = BPF_ALU64 | BPF_MOV | BPF_K,           \
  86                 .dst_reg = DST,                                 \
  87                 .src_reg = 0,                                   \
  88                 .off   = 0,                                     \
  89                 .imm   = IMM })
  90
  91 #define BPF_MOV32_IMM(DST, IMM)                                 \
  92         ((struct bpf_insn) {                                    \
  93                 .code  = BPF_ALU | BPF_MOV | BPF_K,             \
  94                 .dst_reg = DST,                                 \
  95                 .src_reg = 0,                                   \
  96                 .off   = 0,                                     \
  97                 .imm   = IMM })
  98
  99 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
 100 #define BPF_LD_IMM64(DST, IMM)                                  \
 101         BPF_LD_IMM64_RAW(DST, 0, IMM)
 102
 103 #define BPF_LD_IMM64_RAW(DST, SRC, IMM)                         \
 104         ((struct bpf_insn) {                                    \
 105                 .code  = BPF_LD | BPF_DW | BPF_IMM,             \
 106                 .dst_reg = DST,                                 \
 107                 .src_reg = SRC,                                 \
 108                 .off   = 0,                                     \
 109                 .imm   = (__u32) (IMM) }),                      \
 110         ((struct bpf_insn) {                                    \
 111                 .code  = 0, /* zero is reserved opcode */       \
 112                 .dst_reg = 0,                                   \
 113                 .src_reg = 0,                                   \
 114                 .off   = 0,                                     \
 115                 .imm   = ((__u64) (IMM)) >> 32 })
 116
 117 #ifndef BPF_PSEUDO_MAP_FD
 118 # define BPF_PSEUDO_MAP_FD      1
 119 #endif
 120
 121 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
 122 #define BPF_LD_MAP_FD(DST, MAP_FD)                              \
 123         BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
 124
 125
 126 /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
 127
 128 #define BPF_LD_ABS(SIZE, IMM)                                   \
 129         ((struct bpf_insn) {                                    \
 130                 .code  = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS,     \
 131                 .dst_reg = 0,                                   \
 132                 .src_reg = 0,                                   \
 133                 .off   = 0,                                     \
 134                 .imm   = IMM })
 135
 136 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */
 137
 138 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF)                        \
 139         ((struct bpf_insn) {                                    \
 140                 .code  = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM,    \
 141                 .dst_reg = DST,                                 \
 142                 .src_reg = SRC,                                 \
 143                 .off   = OFF,                                   \
 144                 .imm   = 0 })
 145
 146 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */
 147
 148 #define BPF_STX_MEM(SIZE, DST, SRC, OFF)                        \
 149         ((struct bpf_insn) {                                    \
 150                 .code  = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM,    \
 151                 .dst_reg = DST,                                 \
 152                 .src_reg = SRC,                                 \
 153                 .off   = OFF,                                   \
 154                 .imm   = 0 })
 155
 156 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */
 157
 158 #define BPF_ST_MEM(SIZE, DST, OFF, IMM)                         \
 159         ((struct bpf_insn) {                                    \
 160                 .code  = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM,     \
 161                 .dst_reg = DST,                                 \
 162                 .src_reg = 0,                                   \
 163                 .off   = OFF,                                   \
 164                 .imm   = IMM })
 165
 166 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
 167
 168 #define BPF_JMP_REG(OP, DST, SRC, OFF)                          \
 169         ((struct bpf_insn) {                                    \
 170                 .code  = BPF_JMP | BPF_OP(OP) | BPF_X,          \
 171                 .dst_reg = DST,                                 \
 172                 .src_reg = SRC,                                 \
 173                 .off   = OFF,                                   \
 174                 .imm   = 0 })
 175
 176 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
 177
 178 #define BPF_JMP_IMM(OP, DST, IMM, OFF)                          \
 179         ((struct bpf_insn) {                                    \
 180                 .code  = BPF_JMP | BPF_OP(OP) | BPF_K,          \
 181                 .dst_reg = DST,                                 \
 182                 .src_reg = 0,                                   \
 183                 .off   = OFF,                                   \
 184                 .imm   = IMM })
 185
 186 /* Raw code statement block */
 187
 188 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM)                  \
 189         ((struct bpf_insn) {                                    \
 190                 .code  = CODE,                                  \
 191                 .dst_reg = DST,                                 \
 192                 .src_reg = SRC,                                 \
 193                 .off   = OFF,                                   \
 194                 .imm   = IMM })
 195
 196 /* Program exit */
 197
 198 #define BPF_EXIT_INSN()                                         \
 199         ((struct bpf_insn) {                                    \
 200                 .code  = BPF_JMP | BPF_EXIT,                    \
 201                 .dst_reg = 0,                                   \
 202                 .src_reg = 0,                                   \
 203                 .off   = 0,                                     \
 204                 .imm   = 0 })
 205
 206 /* create RAW socket and bind to interface 'name' */
 207 int open_raw_sock(const char *name);
 208
 209 struct perf_event_attr;
 210 int perf_event_open(struct perf_event_attr *attr, int pid, int cpu,
 211                     int group_fd, unsigned long flags);
 212 #endif