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 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 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
  89 #define BPF_LD_IMM64(DST, IMM)                                  \
  90         BPF_LD_IMM64_RAW(DST, 0, IMM)
  91
  92 #define BPF_LD_IMM64_RAW(DST, SRC, IMM)                         \
  93         ((struct bpf_insn) {                                    \
  94                 .code  = BPF_LD | BPF_DW | BPF_IMM,             \
  95                 .dst_reg = DST,                                 \
  96                 .src_reg = SRC,                                 \
  97                 .off   = 0,                                     \
  98                 .imm   = (__u32) (IMM) }),                      \
  99         ((struct bpf_insn) {                                    \
 100                 .code  = 0, /* zero is reserved opcode */       \
 101                 .dst_reg = 0,                                   \
 102                 .src_reg = 0,                                   \
 103                 .off   = 0,                                     \
 104                 .imm   = ((__u64) (IMM)) >> 32 })
 105
 106 #ifndef BPF_PSEUDO_MAP_FD
 107 # define BPF_PSEUDO_MAP_FD      1
 108 #endif
 109
 110 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
 111 #define BPF_LD_MAP_FD(DST, MAP_FD)                              \
 112         BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
 113
 114
 115 /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
 116
 117 #define BPF_LD_ABS(SIZE, IMM)                                   \
 118         ((struct bpf_insn) {                                    \
 119                 .code  = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS,     \
 120                 .dst_reg = 0,                                   \
 121                 .src_reg = 0,                                   \
 122                 .off   = 0,                                     \
 123                 .imm   = IMM })
 124
 125 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */
 126
 127 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF)                        \
 128         ((struct bpf_insn) {                                    \
 129                 .code  = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM,    \
 130                 .dst_reg = DST,                                 \
 131                 .src_reg = SRC,                                 \
 132                 .off   = OFF,                                   \
 133                 .imm   = 0 })
 134
 135 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */
 136
 137 #define BPF_STX_MEM(SIZE, DST, SRC, OFF)                        \
 138         ((struct bpf_insn) {                                    \
 139                 .code  = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM,    \
 140                 .dst_reg = DST,                                 \
 141                 .src_reg = SRC,                                 \
 142                 .off   = OFF,                                   \
 143                 .imm   = 0 })
 144
 145 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */
 146
 147 #define BPF_ST_MEM(SIZE, DST, OFF, IMM)                         \
 148         ((struct bpf_insn) {                                    \
 149                 .code  = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM,     \
 150                 .dst_reg = DST,                                 \
 151                 .src_reg = 0,                                   \
 152                 .off   = OFF,                                   \
 153                 .imm   = IMM })
 154
 155 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
 156
 157 #define BPF_JMP_REG(OP, DST, SRC, OFF)                          \
 158         ((struct bpf_insn) {                                    \
 159                 .code  = BPF_JMP | BPF_OP(OP) | BPF_X,          \
 160                 .dst_reg = DST,                                 \
 161                 .src_reg = SRC,                                 \
 162                 .off   = OFF,                                   \
 163                 .imm   = 0 })
 164
 165 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
 166
 167 #define BPF_JMP_IMM(OP, DST, IMM, OFF)                          \
 168         ((struct bpf_insn) {                                    \
 169                 .code  = BPF_JMP | BPF_OP(OP) | BPF_K,          \
 170                 .dst_reg = DST,                                 \
 171                 .src_reg = 0,                                   \
 172                 .off   = OFF,                                   \
 173                 .imm   = IMM })
 174
 175 /* Raw code statement block */
 176
 177 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM)                  \
 178         ((struct bpf_insn) {                                    \
 179                 .code  = CODE,                                  \
 180                 .dst_reg = DST,                                 \
 181                 .src_reg = SRC,                                 \
 182                 .off   = OFF,                                   \
 183                 .imm   = IMM })
 184
 185 /* Program exit */
 186
 187 #define BPF_EXIT_INSN()                                         \
 188         ((struct bpf_insn) {                                    \
 189                 .code  = BPF_JMP | BPF_EXIT,                    \
 190                 .dst_reg = 0,                                   \
 191                 .src_reg = 0,                                   \
 192                 .off   = 0,                                     \
 193                 .imm   = 0 })
 194
 195 /* create RAW socket and bind to interface 'name' */
 196 int open_raw_sock(const char *name);
 197
 198 struct perf_event_attr;
 199 int perf_event_open(struct perf_event_attr *attr, int pid, int cpu,
 200                     int group_fd, unsigned long flags);
 201 #endif