samples/bpf/libbpf.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /* eBPF mini library */
   3 #ifndef __LIBBPF_H
   4 #define __LIBBPF_H
   5
   6 #include <bpf/bpf.h>
   7
   8 struct bpf_insn;
   9
  10 /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
  11
  12 #define BPF_ALU64_REG(OP, DST, SRC)                             \
  13         ((struct bpf_insn) {                                    \
  14                 .code  = BPF_ALU64 | BPF_OP(OP) | BPF_X,        \
  15                 .dst_reg = DST,                                 \
  16                 .src_reg = SRC,                                 \
  17                 .off   = 0,                                     \
  18                 .imm   = 0 })
  19
  20 #define BPF_ALU32_REG(OP, DST, SRC)                             \
  21         ((struct bpf_insn) {                                    \
  22                 .code  = BPF_ALU | BPF_OP(OP) | BPF_X,          \
  23                 .dst_reg = DST,                                 \
  24                 .src_reg = SRC,                                 \
  25                 .off   = 0,                                     \
  26                 .imm   = 0 })
  27
  28 /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
  29
  30 #define BPF_ALU64_IMM(OP, DST, IMM)                             \
  31         ((struct bpf_insn) {                                    \
  32                 .code  = BPF_ALU64 | BPF_OP(OP) | BPF_K,        \
  33                 .dst_reg = DST,                                 \
  34                 .src_reg = 0,                                   \
  35                 .off   = 0,                                     \
  36                 .imm   = IMM })
  37
  38 #define BPF_ALU32_IMM(OP, DST, IMM)                             \
  39         ((struct bpf_insn) {                                    \
  40                 .code  = BPF_ALU | BPF_OP(OP) | BPF_K,          \
  41                 .dst_reg = DST,                                 \
  42                 .src_reg = 0,                                   \
  43                 .off   = 0,                                     \
  44                 .imm   = IMM })
  45
  46 /* Short form of mov, dst_reg = src_reg */
  47
  48 #define BPF_MOV64_REG(DST, SRC)                                 \
  49         ((struct bpf_insn) {                                    \
  50                 .code  = BPF_ALU64 | BPF_MOV | BPF_X,           \
  51                 .dst_reg = DST,                                 \
  52                 .src_reg = SRC,                                 \
  53                 .off   = 0,                                     \
  54                 .imm   = 0 })
  55
  56 #define BPF_MOV32_REG(DST, SRC)                                 \
  57         ((struct bpf_insn) {                                    \
  58                 .code  = BPF_ALU | BPF_MOV | BPF_X,             \
  59                 .dst_reg = DST,                                 \
  60                 .src_reg = SRC,                                 \
  61                 .off   = 0,                                     \
  62                 .imm   = 0 })
  63
  64 /* Short form of mov, dst_reg = imm32 */
  65
  66 #define BPF_MOV64_IMM(DST, IMM)                                 \
  67         ((struct bpf_insn) {                                    \
  68                 .code  = BPF_ALU64 | BPF_MOV | BPF_K,           \
  69                 .dst_reg = DST,                                 \
  70                 .src_reg = 0,                                   \
  71                 .off   = 0,                                     \
  72                 .imm   = IMM })
  73
  74 #define BPF_MOV32_IMM(DST, IMM)                                 \
  75         ((struct bpf_insn) {                                    \
  76                 .code  = BPF_ALU | BPF_MOV | BPF_K,             \
  77                 .dst_reg = DST,                                 \
  78                 .src_reg = 0,                                   \
  79                 .off   = 0,                                     \
  80                 .imm   = IMM })
  81
  82 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
  83 #define BPF_LD_IMM64(DST, IMM)                                  \
  84         BPF_LD_IMM64_RAW(DST, 0, IMM)
  85
  86 #define BPF_LD_IMM64_RAW(DST, SRC, IMM)                         \
  87         ((struct bpf_insn) {                                    \
  88                 .code  = BPF_LD | BPF_DW | BPF_IMM,             \
  89                 .dst_reg = DST,                                 \
  90                 .src_reg = SRC,                                 \
  91                 .off   = 0,                                     \
  92                 .imm   = (__u32) (IMM) }),                      \
  93         ((struct bpf_insn) {                                    \
  94                 .code  = 0, /* zero is reserved opcode */       \
  95                 .dst_reg = 0,                                   \
  96                 .src_reg = 0,                                   \
  97                 .off   = 0,                                     \
  98                 .imm   = ((__u64) (IMM)) >> 32 })
  99
 100 #ifndef BPF_PSEUDO_MAP_FD
 101 # define BPF_PSEUDO_MAP_FD      1
 102 #endif
 103
 104 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
 105 #define BPF_LD_MAP_FD(DST, MAP_FD)                              \
 106         BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
 107
 108
 109 /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
 110
 111 #define BPF_LD_ABS(SIZE, IMM)                                   \
 112         ((struct bpf_insn) {                                    \
 113                 .code  = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS,     \
 114                 .dst_reg = 0,                                   \
 115                 .src_reg = 0,                                   \
 116                 .off   = 0,                                     \
 117                 .imm   = IMM })
 118
 119 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */
 120
 121 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF)                        \
 122         ((struct bpf_insn) {                                    \
 123                 .code  = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM,    \
 124                 .dst_reg = DST,                                 \
 125                 .src_reg = SRC,                                 \
 126                 .off   = OFF,                                   \
 127                 .imm   = 0 })
 128
 129 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */
 130
 131 #define BPF_STX_MEM(SIZE, DST, SRC, OFF)                        \
 132         ((struct bpf_insn) {                                    \
 133                 .code  = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM,    \
 134                 .dst_reg = DST,                                 \
 135                 .src_reg = SRC,                                 \
 136                 .off   = OFF,                                   \
 137                 .imm   = 0 })
 138
 139 /* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */
 140
 141 #define BPF_STX_XADD(SIZE, DST, SRC, OFF)                       \
 142         ((struct bpf_insn) {                                    \
 143                 .code  = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD,   \
 144                 .dst_reg = DST,                                 \
 145                 .src_reg = SRC,                                 \
 146                 .off   = OFF,                                   \
 147                 .imm   = 0 })
 148
 149 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */
 150
 151 #define BPF_ST_MEM(SIZE, DST, OFF, IMM)                         \
 152         ((struct bpf_insn) {                                    \
 153                 .code  = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM,     \
 154                 .dst_reg = DST,                                 \
 155                 .src_reg = 0,                                   \
 156                 .off   = OFF,                                   \
 157                 .imm   = IMM })
 158
 159 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
 160
 161 #define BPF_JMP_REG(OP, DST, SRC, OFF)                          \
 162         ((struct bpf_insn) {                                    \
 163                 .code  = BPF_JMP | BPF_OP(OP) | BPF_X,          \
 164                 .dst_reg = DST,                                 \
 165                 .src_reg = SRC,                                 \
 166                 .off   = OFF,                                   \
 167                 .imm   = 0 })
 168
 169 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
 170
 171 #define BPF_JMP_IMM(OP, DST, IMM, OFF)                          \
 172         ((struct bpf_insn) {                                    \
 173                 .code  = BPF_JMP | BPF_OP(OP) | BPF_K,          \
 174                 .dst_reg = DST,                                 \
 175                 .src_reg = 0,                                   \
 176                 .off   = OFF,                                   \
 177                 .imm   = IMM })
 178
 179 /* Raw code statement block */
 180
 181 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM)                  \
 182         ((struct bpf_insn) {                                    \
 183                 .code  = CODE,                                  \
 184                 .dst_reg = DST,                                 \
 185                 .src_reg = SRC,                                 \
 186                 .off   = OFF,                                   \
 187                 .imm   = IMM })
 188
 189 /* Program exit */
 190
 191 #define BPF_EXIT_INSN()                                         \
 192         ((struct bpf_insn) {                                    \
 193                 .code  = BPF_JMP | BPF_EXIT,                    \
 194                 .dst_reg = 0,                                   \
 195                 .src_reg = 0,                                   \
 196                 .off   = 0,                                     \
 197                 .imm   = 0 })
 198
 199 #endif