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);
  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 /* Short form of mov, dst_reg = imm32 */
  68
  69 #define BPF_MOV64_IMM(DST, IMM)                                 \
  70         ((struct bpf_insn) {                                    \
  71                 .code  = BPF_ALU64 | BPF_MOV | BPF_K,           \
  72                 .dst_reg = DST,                                 \
  73                 .src_reg = 0,                                   \
  74                 .off   = 0,                                     \
  75                 .imm   = IMM })
  76
  77 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
  78 #define BPF_LD_IMM64(DST, IMM)                                  \
  79         BPF_LD_IMM64_RAW(DST, 0, IMM)
  80
  81 #define BPF_LD_IMM64_RAW(DST, SRC, IMM)                         \
  82         ((struct bpf_insn) {                                    \
  83                 .code  = BPF_LD | BPF_DW | BPF_IMM,             \
  84                 .dst_reg = DST,                                 \
  85                 .src_reg = SRC,                                 \
  86                 .off   = 0,                                     \
  87                 .imm   = (__u32) (IMM) }),                      \
  88         ((struct bpf_insn) {                                    \
  89                 .code  = 0, /* zero is reserved opcode */       \
  90                 .dst_reg = 0,                                   \
  91                 .src_reg = 0,                                   \
  92                 .off   = 0,                                     \
  93                 .imm   = ((__u64) (IMM)) >> 32 })
  94
  95 #define BPF_PSEUDO_MAP_FD       1
  96
  97 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
  98 #define BPF_LD_MAP_FD(DST, MAP_FD)                              \
  99         BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
 100
 101
 102 /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
 103
 104 #define BPF_LD_ABS(SIZE, IMM)                                   \
 105         ((struct bpf_insn) {                                    \
 106                 .code  = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS,     \
 107                 .dst_reg = 0,                                   \
 108                 .src_reg = 0,                                   \
 109                 .off   = 0,                                     \
 110                 .imm   = IMM })
 111
 112 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */
 113
 114 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF)                        \
 115         ((struct bpf_insn) {                                    \
 116                 .code  = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM,    \
 117                 .dst_reg = DST,                                 \
 118                 .src_reg = SRC,                                 \
 119                 .off   = OFF,                                   \
 120                 .imm   = 0 })
 121
 122 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */
 123
 124 #define BPF_STX_MEM(SIZE, DST, SRC, OFF)                        \
 125         ((struct bpf_insn) {                                    \
 126                 .code  = BPF_STX | 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) = imm32 */
 133
 134 #define BPF_ST_MEM(SIZE, DST, OFF, IMM)                         \
 135         ((struct bpf_insn) {                                    \
 136                 .code  = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM,     \
 137                 .dst_reg = DST,                                 \
 138                 .src_reg = 0,                                   \
 139                 .off   = OFF,                                   \
 140                 .imm   = IMM })
 141
 142 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
 143
 144 #define BPF_JMP_REG(OP, DST, SRC, OFF)                          \
 145         ((struct bpf_insn) {                                    \
 146                 .code  = BPF_JMP | BPF_OP(OP) | BPF_X,          \
 147                 .dst_reg = DST,                                 \
 148                 .src_reg = SRC,                                 \
 149                 .off   = OFF,                                   \
 150                 .imm   = 0 })
 151
 152 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
 153
 154 #define BPF_JMP_IMM(OP, DST, IMM, OFF)                          \
 155         ((struct bpf_insn) {                                    \
 156                 .code  = BPF_JMP | BPF_OP(OP) | BPF_K,          \
 157                 .dst_reg = DST,                                 \
 158                 .src_reg = 0,                                   \
 159                 .off   = OFF,                                   \
 160                 .imm   = IMM })
 161
 162 /* Raw code statement block */
 163
 164 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM)                  \
 165         ((struct bpf_insn) {                                    \
 166                 .code  = CODE,                                  \
 167                 .dst_reg = DST,                                 \
 168                 .src_reg = SRC,                                 \
 169                 .off   = OFF,                                   \
 170                 .imm   = IMM })
 171
 172 /* Program exit */
 173
 174 #define BPF_EXIT_INSN()                                         \
 175         ((struct bpf_insn) {                                    \
 176                 .code  = BPF_JMP | BPF_EXIT,                    \
 177                 .dst_reg = 0,                                   \
 178                 .src_reg = 0,                                   \
 179                 .off   = 0,                                     \
 180                 .imm   = 0 })
 181
 182 /* create RAW socket and bind to interface 'name' */
 183 int open_raw_sock(const char *name);
 184
 185 #endif