samples/bpf/libbpf.h

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