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);
   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 #define LOG_BUF_SIZE 65536
  19 extern char bpf_log_buf[LOG_BUF_SIZE];
  20
  21 /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
  22
  23 #define BPF_ALU64_REG(OP, DST, SRC)                             \
  24         ((struct bpf_insn) {                                    \
  25                 .code  = BPF_ALU64 | BPF_OP(OP) | BPF_X,        \
  26                 .dst_reg = DST,                                 \
  27                 .src_reg = SRC,                                 \
  28                 .off   = 0,                                     \
  29                 .imm   = 0 })
  30
  31 #define BPF_ALU32_REG(OP, DST, SRC)                             \
  32         ((struct bpf_insn) {                                    \
  33                 .code  = BPF_ALU | BPF_OP(OP) | BPF_X,          \
  34                 .dst_reg = DST,                                 \
  35                 .src_reg = SRC,                                 \
  36                 .off   = 0,                                     \
  37                 .imm   = 0 })
  38
  39 /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
  40
  41 #define BPF_ALU64_IMM(OP, DST, IMM)                             \
  42         ((struct bpf_insn) {                                    \
  43                 .code  = BPF_ALU64 | BPF_OP(OP) | BPF_K,        \
  44                 .dst_reg = DST,                                 \
  45                 .src_reg = 0,                                   \
  46                 .off   = 0,                                     \
  47                 .imm   = IMM })
  48
  49 #define BPF_ALU32_IMM(OP, DST, IMM)                             \
  50         ((struct bpf_insn) {                                    \
  51                 .code  = BPF_ALU | BPF_OP(OP) | BPF_K,          \
  52                 .dst_reg = DST,                                 \
  53                 .src_reg = 0,                                   \
  54                 .off   = 0,                                     \
  55                 .imm   = IMM })
  56
  57 /* Short form of mov, dst_reg = src_reg */
  58
  59 #define BPF_MOV64_REG(DST, SRC)                                 \
  60         ((struct bpf_insn) {                                    \
  61                 .code  = BPF_ALU64 | BPF_MOV | BPF_X,           \
  62                 .dst_reg = DST,                                 \
  63                 .src_reg = SRC,                                 \
  64                 .off   = 0,                                     \
  65                 .imm   = 0 })
  66
  67 #define BPF_MOV32_REG(DST, SRC)                                 \
  68         ((struct bpf_insn) {                                    \
  69                 .code  = BPF_ALU | BPF_MOV | BPF_X,             \
  70                 .dst_reg = DST,                                 \
  71                 .src_reg = SRC,                                 \
  72                 .off   = 0,                                     \
  73                 .imm   = 0 })
  74
  75 /* Short form of mov, dst_reg = imm32 */
  76
  77 #define BPF_MOV64_IMM(DST, IMM)                                 \
  78         ((struct bpf_insn) {                                    \
  79                 .code  = BPF_ALU64 | BPF_MOV | BPF_K,           \
  80                 .dst_reg = DST,                                 \
  81                 .src_reg = 0,                                   \
  82                 .off   = 0,                                     \
  83                 .imm   = IMM })
  84
  85 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
  86 #define BPF_LD_IMM64(DST, IMM)                                  \
  87         BPF_LD_IMM64_RAW(DST, 0, IMM)
  88
  89 #define BPF_LD_IMM64_RAW(DST, SRC, IMM)                         \
  90         ((struct bpf_insn) {                                    \
  91                 .code  = BPF_LD | BPF_DW | BPF_IMM,             \
  92                 .dst_reg = DST,                                 \
  93                 .src_reg = SRC,                                 \
  94                 .off   = 0,                                     \
  95                 .imm   = (__u32) (IMM) }),                      \
  96         ((struct bpf_insn) {                                    \
  97                 .code  = 0, /* zero is reserved opcode */       \
  98                 .dst_reg = 0,                                   \
  99                 .src_reg = 0,                                   \
 100                 .off   = 0,                                     \
 101                 .imm   = ((__u64) (IMM)) >> 32 })
 102
 103 #ifndef BPF_PSEUDO_MAP_FD
 104 # define BPF_PSEUDO_MAP_FD      1
 105 #endif
 106
 107 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
 108 #define BPF_LD_MAP_FD(DST, MAP_FD)                              \
 109         BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
 110
 111
 112 /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
 113
 114 #define BPF_LD_ABS(SIZE, IMM)                                   \
 115         ((struct bpf_insn) {                                    \
 116                 .code  = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS,     \
 117                 .dst_reg = 0,                                   \
 118                 .src_reg = 0,                                   \
 119                 .off   = 0,                                     \
 120                 .imm   = IMM })
 121
 122 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */
 123
 124 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF)                        \
 125         ((struct bpf_insn) {                                    \
 126                 .code  = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM,    \
 127                 .dst_reg = DST,                                 \
 128                 .src_reg = SRC,                                 \
 129                 .off   = OFF,                                   \
 130                 .imm   = 0 })
 131
 132 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */
 133
 134 #define BPF_STX_MEM(SIZE, DST, SRC, OFF)                        \
 135         ((struct bpf_insn) {                                    \
 136                 .code  = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM,    \
 137                 .dst_reg = DST,                                 \
 138                 .src_reg = SRC,                                 \
 139                 .off   = OFF,                                   \
 140                 .imm   = 0 })
 141
 142 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */
 143
 144 #define BPF_ST_MEM(SIZE, DST, OFF, IMM)                         \
 145         ((struct bpf_insn) {                                    \
 146                 .code  = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM,     \
 147                 .dst_reg = DST,                                 \
 148                 .src_reg = 0,                                   \
 149                 .off   = OFF,                                   \
 150                 .imm   = IMM })
 151
 152 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
 153
 154 #define BPF_JMP_REG(OP, DST, SRC, OFF)                          \
 155         ((struct bpf_insn) {                                    \
 156                 .code  = BPF_JMP | BPF_OP(OP) | BPF_X,          \
 157                 .dst_reg = DST,                                 \
 158                 .src_reg = SRC,                                 \
 159                 .off   = OFF,                                   \
 160                 .imm   = 0 })
 161
 162 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
 163
 164 #define BPF_JMP_IMM(OP, DST, IMM, OFF)                          \
 165         ((struct bpf_insn) {                                    \
 166                 .code  = BPF_JMP | BPF_OP(OP) | BPF_K,          \
 167                 .dst_reg = DST,                                 \
 168                 .src_reg = 0,                                   \
 169                 .off   = OFF,                                   \
 170                 .imm   = IMM })
 171
 172 /* Raw code statement block */
 173
 174 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM)                  \
 175         ((struct bpf_insn) {                                    \
 176                 .code  = CODE,                                  \
 177                 .dst_reg = DST,                                 \
 178                 .src_reg = SRC,                                 \
 179                 .off   = OFF,                                   \
 180                 .imm   = IMM })
 181
 182 /* Program exit */
 183
 184 #define BPF_EXIT_INSN()                                         \
 185         ((struct bpf_insn) {                                    \
 186                 .code  = BPF_JMP | BPF_EXIT,                    \
 187                 .dst_reg = 0,                                   \
 188                 .src_reg = 0,                                   \
 189                 .off   = 0,                                     \
 190                 .imm   = 0 })
 191
 192 /* create RAW socket and bind to interface 'name' */
 193 int open_raw_sock(const char *name);
 194
 195 struct perf_event_attr;
 196 int perf_event_open(struct perf_event_attr *attr, int pid, int cpu,
 197                     int group_fd, unsigned long flags);
 198 #endif