LXR linux/tools/include/linux/filter.h

   1/*
   2 * Linux Socket Filter Data Structures
   3 */
   4#ifndef __TOOLS_LINUX_FILTER_H
   5#define __TOOLS_LINUX_FILTER_H
   6
   7#include <linux/bpf.h>
   8
   9/* ArgX, context and stack frame pointer register positions. Note,
  10 * Arg1, Arg2, Arg3, etc are used as argument mappings of function
  11 * calls in BPF_CALL instruction.
  12 */
  13#define BPF_REG_ARG1    BPF_REG_1
  14#define BPF_REG_ARG2    BPF_REG_2
  15#define BPF_REG_ARG3    BPF_REG_3
  16#define BPF_REG_ARG4    BPF_REG_4
  17#define BPF_REG_ARG5    BPF_REG_5
  18#define BPF_REG_CTX     BPF_REG_6
  19#define BPF_REG_FP      BPF_REG_10
  20
  21/* Additional register mappings for converted user programs. */
  22#define BPF_REG_A       BPF_REG_0
  23#define BPF_REG_X       BPF_REG_7
  24#define BPF_REG_TMP     BPF_REG_8
  25
  26/* BPF program can access up to 512 bytes of stack space. */
  27#define MAX_BPF_STACK   512
  28
  29/* Helper macros for filter block array initializers. */
  30
  31/* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
  32
  33#define BPF_ALU64_REG(OP, DST, SRC)                             \
  34        ((struct bpf_insn) {                                    \
  35                .code  = BPF_ALU64 | BPF_OP(OP) | BPF_X,        \
  36                .dst_reg = DST,                                 \
  37                .src_reg = SRC,                                 \
  38                .off   = 0,                                     \
  39                .imm   = 0 })
  40
  41#define BPF_ALU32_REG(OP, DST, SRC)                             \
  42        ((struct bpf_insn) {                                    \
  43                .code  = BPF_ALU | BPF_OP(OP) | BPF_X,          \
  44                .dst_reg = DST,                                 \
  45                .src_reg = SRC,                                 \
  46                .off   = 0,                                     \
  47                .imm   = 0 })
  48
  49/* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
  50
  51#define BPF_ALU64_IMM(OP, DST, IMM)                             \
  52        ((struct bpf_insn) {                                    \
  53                .code  = BPF_ALU64 | BPF_OP(OP) | BPF_K,        \
  54                .dst_reg = DST,                                 \
  55                .src_reg = 0,                                   \
  56                .off   = 0,                                     \
  57                .imm   = IMM })
  58
  59#define BPF_ALU32_IMM(OP, DST, IMM)                             \
  60        ((struct bpf_insn) {                                    \
  61                .code  = BPF_ALU | BPF_OP(OP) | BPF_K,          \
  62                .dst_reg = DST,                                 \
  63                .src_reg = 0,                                   \
  64                .off   = 0,                                     \
  65                .imm   = IMM })
  66
  67/* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */
  68
  69#define BPF_ENDIAN(TYPE, DST, LEN)                              \
  70        ((struct bpf_insn) {                                    \
  71                .code  = BPF_ALU | BPF_END | BPF_SRC(TYPE),     \
  72                .dst_reg = DST,                                 \
  73                .src_reg = 0,                                   \
  74                .off   = 0,                                     \
  75                .imm   = LEN })
  76
  77/* Short form of mov, dst_reg = src_reg */
  78
  79#define BPF_MOV64_REG(DST, SRC)                                 \
  80        ((struct bpf_insn) {                                    \
  81                .code  = BPF_ALU64 | BPF_MOV | BPF_X,           \
  82                .dst_reg = DST,                                 \
  83                .src_reg = SRC,                                 \
  84                .off   = 0,                                     \
  85                .imm   = 0 })
  86
  87#define BPF_MOV32_REG(DST, SRC)                                 \
  88        ((struct bpf_insn) {                                    \
  89                .code  = BPF_ALU | BPF_MOV | BPF_X,             \
  90                .dst_reg = DST,                                 \
  91                .src_reg = SRC,                                 \
  92                .off   = 0,                                     \
  93                .imm   = 0 })
  94
  95/* Short form of mov, dst_reg = imm32 */
  96
  97#define BPF_MOV64_IMM(DST, IMM)                                 \
  98        ((struct bpf_insn) {                                    \
  99                .code  = BPF_ALU64 | BPF_MOV | BPF_K,           \
 100                .dst_reg = DST,                                 \
 101                .src_reg = 0,                                   \
 102                .off   = 0,                                     \
 103                .imm   = IMM })
 104
 105#define BPF_MOV32_IMM(DST, IMM)                                 \
 106        ((struct bpf_insn) {                                    \
 107                .code  = BPF_ALU | BPF_MOV | BPF_K,             \
 108                .dst_reg = DST,                                 \
 109                .src_reg = 0,                                   \
 110                .off   = 0,                                     \
 111                .imm   = IMM })
 112
 113/* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
 114#define BPF_LD_IMM64(DST, IMM)                                  \
 115        BPF_LD_IMM64_RAW(DST, 0, IMM)
 116
 117#define BPF_LD_IMM64_RAW(DST, SRC, IMM)                         \
 118        ((struct bpf_insn) {                                    \
 119                .code  = BPF_LD | BPF_DW | BPF_IMM,             \
 120                .dst_reg = DST,                                 \
 121                .src_reg = SRC,                                 \
 122                .off   = 0,                                     \
 123                .imm   = (__u32) (IMM) }),                      \
 124        ((struct bpf_insn) {                                    \
 125                .code  = 0, /* zero is reserved opcode */       \
 126                .dst_reg = 0,                                   \
 127                .src_reg = 0,                                   \
 128                .off   = 0,                                     \
 129                .imm   = ((__u64) (IMM)) >> 32 })
 130
 131#define BPF_PSEUDO_MAP_FD       1
 132
 133/* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
 134#define BPF_LD_MAP_FD(DST, MAP_FD)                              \
 135        BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
 136
 137/* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */
 138
 139#define BPF_MOV64_RAW(TYPE, DST, SRC, IMM)                      \
 140        ((struct bpf_insn) {                                    \
 141                .code  = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE),   \
 142                .dst_reg = DST,                                 \
 143                .src_reg = SRC,                                 \
 144                .off   = 0,                                     \
 145                .imm   = IMM })
 146
 147#define BPF_MOV32_RAW(TYPE, DST, SRC, IMM)                      \
 148        ((struct bpf_insn) {                                    \
 149                .code  = BPF_ALU | BPF_MOV | BPF_SRC(TYPE),     \
 150                .dst_reg = DST,                                 \
 151                .src_reg = SRC,                                 \
 152                .off   = 0,                                     \
 153                .imm   = IMM })
 154
 155/* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
 156
 157#define BPF_LD_ABS(SIZE, IMM)                                   \
 158        ((struct bpf_insn) {                                    \
 159                .code  = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS,     \
 160                .dst_reg = 0,                                   \
 161                .src_reg = 0,                                   \
 162                .off   = 0,                                     \
 163                .imm   = IMM })
 164
 165/* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */
 166
 167#define BPF_LD_IND(SIZE, SRC, IMM)                              \
 168        ((struct bpf_insn) {                                    \
 169                .code  = BPF_LD | BPF_SIZE(SIZE) | BPF_IND,     \
 170                .dst_reg = 0,                                   \
 171                .src_reg = SRC,                                 \
 172                .off   = 0,                                     \
 173                .imm   = IMM })
 174
 175/* Memory load, dst_reg = *(uint *) (src_reg + off16) */
 176
 177#define BPF_LDX_MEM(SIZE, DST, SRC, OFF)                        \
 178        ((struct bpf_insn) {                                    \
 179                .code  = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM,    \
 180                .dst_reg = DST,                                 \
 181                .src_reg = SRC,                                 \
 182                .off   = OFF,                                   \
 183                .imm   = 0 })
 184
 185/* Memory store, *(uint *) (dst_reg + off16) = src_reg */
 186
 187#define BPF_STX_MEM(SIZE, DST, SRC, OFF)                        \
 188        ((struct bpf_insn) {                                    \
 189                .code  = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM,    \
 190                .dst_reg = DST,                                 \
 191                .src_reg = SRC,                                 \
 192                .off   = OFF,                                   \
 193                .imm   = 0 })
 194
 195/* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */
 196
 197#define BPF_STX_XADD(SIZE, DST, SRC, OFF)                       \
 198        ((struct bpf_insn) {                                    \
 199                .code  = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD,   \
 200                .dst_reg = DST,                                 \
 201                .src_reg = SRC,                                 \
 202                .off   = OFF,                                   \
 203                .imm   = 0 })
 204
 205/* Memory store, *(uint *) (dst_reg + off16) = imm32 */
 206
 207#define BPF_ST_MEM(SIZE, DST, OFF, IMM)                         \
 208        ((struct bpf_insn) {                                    \
 209                .code  = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM,     \
 210                .dst_reg = DST,                                 \
 211                .src_reg = 0,                                   \
 212                .off   = OFF,                                   \
 213                .imm   = IMM })
 214
 215/* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
 216
 217#define BPF_JMP_REG(OP, DST, SRC, OFF)                          \
 218        ((struct bpf_insn) {                                    \
 219                .code  = BPF_JMP | BPF_OP(OP) | BPF_X,          \
 220                .dst_reg = DST,                                 \
 221                .src_reg = SRC,                                 \
 222                .off   = OFF,                                   \
 223                .imm   = 0 })
 224
 225/* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
 226
 227#define BPF_JMP_IMM(OP, DST, IMM, OFF)                          \
 228        ((struct bpf_insn) {                                    \
 229                .code  = BPF_JMP | BPF_OP(OP) | BPF_K,          \
 230                .dst_reg = DST,                                 \
 231                .src_reg = 0,                                   \
 232                .off   = OFF,                                   \
 233                .imm   = IMM })
 234
 235/* Unconditional jumps, goto pc + off16 */
 236
 237#define BPF_JMP_A(OFF)                                          \
 238        ((struct bpf_insn) {                                    \
 239                .code  = BPF_JMP | BPF_JA,                      \
 240                .dst_reg = 0,                                   \
 241                .src_reg = 0,                                   \
 242                .off   = OFF,                                   \
 243                .imm   = 0 })
 244
 245/* Function call */
 246
 247#define BPF_EMIT_CALL(FUNC)                                     \
 248        ((struct bpf_insn) {                                    \
 249                .code  = BPF_JMP | BPF_CALL,                    \
 250                .dst_reg = 0,                                   \
 251                .src_reg = 0,                                   \
 252                .off   = 0,                                     \
 253                .imm   = ((FUNC) - BPF_FUNC_unspec) })
 254
 255/* Raw code statement block */
 256
 257#define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM)                  \
 258        ((struct bpf_insn) {                                    \
 259                .code  = CODE,                                  \
 260                .dst_reg = DST,                                 \
 261                .src_reg = SRC,                                 \
 262                .off   = OFF,                                   \
 263                .imm   = IMM })
 264
 265/* Program exit */
 266
 267#define BPF_EXIT_INSN()                                         \
 268        ((struct bpf_insn) {                                    \
 269                .code  = BPF_JMP | BPF_EXIT,                    \
 270                .dst_reg = 0,                                   \
 271                .src_reg = 0,                                   \
 272                .off   = 0,                                     \
 273                .imm   = 0 })
 274
 275#endif /* __TOOLS_LINUX_FILTER_H */
 276