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