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_obj_pin(int fd, const char *pathname);
  19 int bpf_obj_get(const char *pathname);
  20
  21 #define LOG_BUF_SIZE 65536
  22 extern char bpf_log_buf[LOG_BUF_SIZE];
  23
  24 /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
  25
  26 #define BPF_ALU64_REG(OP, DST, SRC)                             \
  27         ((struct bpf_insn) {                                    \
  28                 .code  = BPF_ALU64 | BPF_OP(OP) | BPF_X,        \
  29                 .dst_reg = DST,                                 \
  30                 .src_reg = SRC,                                 \
  31                 .off   = 0,                                     \
  32                 .imm   = 0 })
  33
  34 #define BPF_ALU32_REG(OP, DST, SRC)                             \
  35         ((struct bpf_insn) {                                    \
  36                 .code  = BPF_ALU | BPF_OP(OP) | BPF_X,          \
  37                 .dst_reg = DST,                                 \
  38                 .src_reg = SRC,                                 \
  39                 .off   = 0,                                     \
  40                 .imm   = 0 })
  41
  42 /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
  43
  44 #define BPF_ALU64_IMM(OP, DST, IMM)                             \
  45         ((struct bpf_insn) {                                    \
  46                 .code  = BPF_ALU64 | BPF_OP(OP) | BPF_K,        \
  47                 .dst_reg = DST,                                 \
  48                 .src_reg = 0,                                   \
  49                 .off   = 0,                                     \
  50                 .imm   = IMM })
  51
  52 #define BPF_ALU32_IMM(OP, DST, IMM)                             \
  53         ((struct bpf_insn) {                                    \
  54                 .code  = BPF_ALU | BPF_OP(OP) | BPF_K,          \
  55                 .dst_reg = DST,                                 \
  56                 .src_reg = 0,                                   \
  57                 .off   = 0,                                     \
  58                 .imm   = IMM })
  59
  60 /* Short form of mov, dst_reg = src_reg */
  61
  62 #define BPF_MOV64_REG(DST, SRC)                                 \
  63         ((struct bpf_insn) {                                    \
  64                 .code  = BPF_ALU64 | BPF_MOV | BPF_X,           \
  65                 .dst_reg = DST,                                 \
  66                 .src_reg = SRC,                                 \
  67                 .off   = 0,                                     \
  68                 .imm   = 0 })
  69
  70 #define BPF_MOV32_REG(DST, SRC)                                 \
  71         ((struct bpf_insn) {                                    \
  72                 .code  = BPF_ALU | BPF_MOV | BPF_X,             \
  73                 .dst_reg = DST,                                 \
  74                 .src_reg = SRC,                                 \
  75                 .off   = 0,                                     \
  76                 .imm   = 0 })
  77
  78 /* Short form of mov, dst_reg = imm32 */
  79
  80 #define BPF_MOV64_IMM(DST, IMM)                                 \
  81         ((struct bpf_insn) {                                    \
  82                 .code  = BPF_ALU64 | BPF_MOV | BPF_K,           \
  83                 .dst_reg = DST,                                 \
  84                 .src_reg = 0,                                   \
  85                 .off   = 0,                                     \
  86                 .imm   = IMM })
  87
  88 #define BPF_MOV32_IMM(DST, IMM)                                 \
  89         ((struct bpf_insn) {                                    \
  90                 .code  = BPF_ALU | BPF_MOV | BPF_K,             \
  91                 .dst_reg = DST,                                 \
  92                 .src_reg = 0,                                   \
  93                 .off   = 0,                                     \
  94                 .imm   = IMM })
  95
  96 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
  97 #define BPF_LD_IMM64(DST, IMM)                                  \
  98         BPF_LD_IMM64_RAW(DST, 0, IMM)
  99
 100 #define BPF_LD_IMM64_RAW(DST, SRC, IMM)                         \
 101         ((struct bpf_insn) {                                    \
 102                 .code  = BPF_LD | BPF_DW | BPF_IMM,             \
 103                 .dst_reg = DST,                                 \
 104                 .src_reg = SRC,                                 \
 105                 .off   = 0,                                     \
 106                 .imm   = (__u32) (IMM) }),                      \
 107         ((struct bpf_insn) {                                    \
 108                 .code  = 0, /* zero is reserved opcode */       \
 109                 .dst_reg = 0,                                   \
 110                 .src_reg = 0,                                   \
 111                 .off   = 0,                                     \
 112                 .imm   = ((__u64) (IMM)) >> 32 })
 113
 114 #ifndef BPF_PSEUDO_MAP_FD
 115 # define BPF_PSEUDO_MAP_FD      1
 116 #endif
 117
 118 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
 119 #define BPF_LD_MAP_FD(DST, MAP_FD)                              \
 120         BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
 121
 122
 123 /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
 124
 125 #define BPF_LD_ABS(SIZE, IMM)                                   \
 126         ((struct bpf_insn) {                                    \
 127                 .code  = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS,     \
 128                 .dst_reg = 0,                                   \
 129                 .src_reg = 0,                                   \
 130                 .off   = 0,                                     \
 131                 .imm   = IMM })
 132
 133 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */
 134
 135 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF)                        \
 136         ((struct bpf_insn) {                                    \
 137                 .code  = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM,    \
 138                 .dst_reg = DST,                                 \
 139                 .src_reg = SRC,                                 \
 140                 .off   = OFF,                                   \
 141                 .imm   = 0 })
 142
 143 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */
 144
 145 #define BPF_STX_MEM(SIZE, DST, SRC, OFF)                        \
 146         ((struct bpf_insn) {                                    \
 147                 .code  = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM,    \
 148                 .dst_reg = DST,                                 \
 149                 .src_reg = SRC,                                 \
 150                 .off   = OFF,                                   \
 151                 .imm   = 0 })
 152
 153 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */
 154
 155 #define BPF_ST_MEM(SIZE, DST, OFF, IMM)                         \
 156         ((struct bpf_insn) {                                    \
 157                 .code  = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM,     \
 158                 .dst_reg = DST,                                 \
 159                 .src_reg = 0,                                   \
 160                 .off   = OFF,                                   \
 161                 .imm   = IMM })
 162
 163 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
 164
 165 #define BPF_JMP_REG(OP, DST, SRC, OFF)                          \
 166         ((struct bpf_insn) {                                    \
 167                 .code  = BPF_JMP | BPF_OP(OP) | BPF_X,          \
 168                 .dst_reg = DST,                                 \
 169                 .src_reg = SRC,                                 \
 170                 .off   = OFF,                                   \
 171                 .imm   = 0 })
 172
 173 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
 174
 175 #define BPF_JMP_IMM(OP, DST, IMM, OFF)                          \
 176         ((struct bpf_insn) {                                    \
 177                 .code  = BPF_JMP | BPF_OP(OP) | BPF_K,          \
 178                 .dst_reg = DST,                                 \
 179                 .src_reg = 0,                                   \
 180                 .off   = OFF,                                   \
 181                 .imm   = IMM })
 182
 183 /* Raw code statement block */
 184
 185 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM)                  \
 186         ((struct bpf_insn) {                                    \
 187                 .code  = CODE,                                  \
 188                 .dst_reg = DST,                                 \
 189                 .src_reg = SRC,                                 \
 190                 .off   = OFF,                                   \
 191                 .imm   = IMM })
 192
 193 /* Program exit */
 194
 195 #define BPF_EXIT_INSN()                                         \
 196         ((struct bpf_insn) {                                    \
 197                 .code  = BPF_JMP | BPF_EXIT,                    \
 198                 .dst_reg = 0,                                   \
 199                 .src_reg = 0,                                   \
 200                 .off   = 0,                                     \
 201                 .imm   = 0 })
 202
 203 /* create RAW socket and bind to interface 'name' */
 204 int open_raw_sock(const char *name);
 205
 206 struct perf_event_attr;
 207 int perf_event_open(struct perf_event_attr *attr, int pid, int cpu,
 208                     int group_fd, unsigned long flags);
 209 #endif