tools/include/linux/filter.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Linux Socket Filter Data Structures
   4  */
   5 #ifndef __TOOLS_LINUX_FILTER_H
   6 #define __TOOLS_LINUX_FILTER_H
   7
   8 #include <linux/bpf.h>
   9
  10 /* ArgX, context and stack frame pointer register positions. Note,
  11  * Arg1, Arg2, Arg3, etc are used as argument mappings of function
  12  * calls in BPF_CALL instruction.
  13  */
  14 #define BPF_REG_ARG1    BPF_REG_1
  15 #define BPF_REG_ARG2    BPF_REG_2
  16 #define BPF_REG_ARG3    BPF_REG_3
  17 #define BPF_REG_ARG4    BPF_REG_4
  18 #define BPF_REG_ARG5    BPF_REG_5
  19 #define BPF_REG_CTX     BPF_REG_6
  20 #define BPF_REG_FP      BPF_REG_10
  21
  22 /* Additional register mappings for converted user programs. */
  23 #define BPF_REG_A       BPF_REG_0
  24 #define BPF_REG_X       BPF_REG_7
  25 #define BPF_REG_TMP     BPF_REG_8
  26
  27 /* BPF program can access up to 512 bytes of stack space. */
  28 #define MAX_BPF_STACK   512
  29
  30 /* Helper macros for filter block array initializers. */
  31
  32 /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
  33
  34 #define BPF_ALU64_REG(OP, DST, SRC)                             \
  35         ((struct bpf_insn) {                                    \
  36                 .code  = BPF_ALU64 | BPF_OP(OP) | BPF_X,        \
  37                 .dst_reg = DST,                                 \
  38                 .src_reg = SRC,                                 \
  39                 .off   = 0,                                     \
  40                 .imm   = 0 })
  41
  42 #define BPF_ALU32_REG(OP, DST, SRC)                             \
  43         ((struct bpf_insn) {                                    \
  44                 .code  = BPF_ALU | BPF_OP(OP) | BPF_X,          \
  45                 .dst_reg = DST,                                 \
  46                 .src_reg = SRC,                                 \
  47                 .off   = 0,                                     \
  48                 .imm   = 0 })
  49
  50 /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
  51
  52 #define BPF_ALU64_IMM(OP, DST, IMM)                             \
  53         ((struct bpf_insn) {                                    \
  54                 .code  = BPF_ALU64 | BPF_OP(OP) | BPF_K,        \
  55                 .dst_reg = DST,                                 \
  56                 .src_reg = 0,                                   \
  57                 .off   = 0,                                     \
  58                 .imm   = IMM })
  59
  60 #define BPF_ALU32_IMM(OP, DST, IMM)                             \
  61         ((struct bpf_insn) {                                    \
  62                 .code  = BPF_ALU | BPF_OP(OP) | BPF_K,          \
  63                 .dst_reg = DST,                                 \
  64                 .src_reg = 0,                                   \
  65                 .off   = 0,                                     \
  66                 .imm   = IMM })
  67
  68 /* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */
  69
  70 #define BPF_ENDIAN(TYPE, DST, LEN)                              \
  71         ((struct bpf_insn) {                                    \
  72                 .code  = BPF_ALU | BPF_END | BPF_SRC(TYPE),     \
  73                 .dst_reg = DST,                                 \
  74                 .src_reg = 0,                                   \
  75                 .off   = 0,                                     \
  76                 .imm   = LEN })
  77
  78 /* Short form of mov, dst_reg = src_reg */
  79
  80 #define BPF_MOV64_REG(DST, SRC)                                 \
  81         ((struct bpf_insn) {                                    \
  82                 .code  = BPF_ALU64 | BPF_MOV | BPF_X,           \
  83                 .dst_reg = DST,                                 \
  84                 .src_reg = SRC,                                 \
  85                 .off   = 0,                                     \
  86                 .imm   = 0 })
  87
  88 #define BPF_MOV32_REG(DST, SRC)                                 \
  89         ((struct bpf_insn) {                                    \
  90                 .code  = BPF_ALU | BPF_MOV | BPF_X,             \
  91                 .dst_reg = DST,                                 \
  92                 .src_reg = SRC,                                 \
  93                 .off   = 0,                                     \
  94                 .imm   = 0 })
  95
  96 /* Short form of mov, dst_reg = imm32 */
  97
  98 #define BPF_MOV64_IMM(DST, IMM)                                 \
  99         ((struct bpf_insn) {                                    \
 100                 .code  = BPF_ALU64 | BPF_MOV | BPF_K,           \
 101                 .dst_reg = DST,                                 \
 102                 .src_reg = 0,                                   \
 103                 .off   = 0,                                     \
 104                 .imm   = IMM })
 105
 106 #define BPF_MOV32_IMM(DST, IMM)                                 \
 107         ((struct bpf_insn) {                                    \
 108                 .code  = BPF_ALU | BPF_MOV | BPF_K,             \
 109                 .dst_reg = DST,                                 \
 110                 .src_reg = 0,                                   \
 111                 .off   = 0,                                     \
 112                 .imm   = IMM })
 113
 114 /* Short form of mov based on type,  BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */
 115
 116 #define BPF_MOV64_RAW(TYPE, DST, SRC, IMM)                      \
 117         ((struct bpf_insn) {                                    \
 118                 .code  = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE),   \
 119                 .dst_reg = DST,                                 \
 120                 .src_reg = SRC,                                 \
 121                 .off   = 0,                                     \
 122                 .imm   = IMM })
 123
 124 #define BPF_MOV32_RAW(TYPE, DST, SRC, IMM)                      \
 125         ((struct bpf_insn) {                                    \
 126                 .code  = BPF_ALU | BPF_MOV | BPF_SRC(TYPE),     \
 127                 .dst_reg = DST,                                 \
 128                 .src_reg = SRC,                                 \
 129                 .off   = 0,                                     \
 130                 .imm   = IMM })
 131
 132 /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
 133
 134 #define BPF_LD_ABS(SIZE, IMM)                                   \
 135         ((struct bpf_insn) {                                    \
 136                 .code  = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS,     \
 137                 .dst_reg = 0,                                   \
 138                 .src_reg = 0,                                   \
 139                 .off   = 0,                                     \
 140                 .imm   = IMM })
 141
 142 /* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */
 143
 144 #define BPF_LD_IND(SIZE, SRC, IMM)                              \
 145         ((struct bpf_insn) {                                    \
 146                 .code  = BPF_LD | BPF_SIZE(SIZE) | BPF_IND,     \
 147                 .dst_reg = 0,                                   \
 148                 .src_reg = SRC,                                 \
 149                 .off   = 0,                                     \
 150                 .imm   = IMM })
 151
 152 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */
 153
 154 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF)                        \
 155         ((struct bpf_insn) {                                    \
 156                 .code  = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM,    \
 157                 .dst_reg = DST,                                 \
 158                 .src_reg = SRC,                                 \
 159                 .off   = OFF,                                   \
 160                 .imm   = 0 })
 161
 162 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */
 163
 164 #define BPF_STX_MEM(SIZE, DST, SRC, OFF)                        \
 165         ((struct bpf_insn) {                                    \
 166                 .code  = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM,    \
 167                 .dst_reg = DST,                                 \
 168                 .src_reg = SRC,                                 \
 169                 .off   = OFF,                                   \
 170                 .imm   = 0 })
 171
 172 /* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */
 173
 174 #define BPF_STX_XADD(SIZE, DST, SRC, OFF)                       \
 175         ((struct bpf_insn) {                                    \
 176                 .code  = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD,   \
 177                 .dst_reg = DST,                                 \
 178                 .src_reg = SRC,                                 \
 179                 .off   = OFF,                                   \
 180                 .imm   = 0 })
 181
 182 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */
 183
 184 #define BPF_ST_MEM(SIZE, DST, OFF, IMM)                         \
 185         ((struct bpf_insn) {                                    \
 186                 .code  = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM,     \
 187                 .dst_reg = DST,                                 \
 188                 .src_reg = 0,                                   \
 189                 .off   = OFF,                                   \
 190                 .imm   = IMM })
 191
 192 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
 193
 194 #define BPF_JMP_REG(OP, DST, SRC, OFF)                          \
 195         ((struct bpf_insn) {                                    \
 196                 .code  = BPF_JMP | BPF_OP(OP) | BPF_X,          \
 197                 .dst_reg = DST,                                 \
 198                 .src_reg = SRC,                                 \
 199                 .off   = OFF,                                   \
 200                 .imm   = 0 })
 201
 202 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
 203
 204 #define BPF_JMP_IMM(OP, DST, IMM, OFF)                          \
 205         ((struct bpf_insn) {                                    \
 206                 .code  = BPF_JMP | BPF_OP(OP) | BPF_K,          \
 207                 .dst_reg = DST,                                 \
 208                 .src_reg = 0,                                   \
 209                 .off   = OFF,                                   \
 210                 .imm   = IMM })
 211
 212 /* Unconditional jumps, goto pc + off16 */
 213
 214 #define BPF_JMP_A(OFF)                                          \
 215         ((struct bpf_insn) {                                    \
 216                 .code  = BPF_JMP | BPF_JA,                      \
 217                 .dst_reg = 0,                                   \
 218                 .src_reg = 0,                                   \
 219                 .off   = OFF,                                   \
 220                 .imm   = 0 })
 221
 222 /* Function call */
 223
 224 #define BPF_EMIT_CALL(FUNC)                                     \
 225         ((struct bpf_insn) {                                    \
 226                 .code  = BPF_JMP | BPF_CALL,                    \
 227                 .dst_reg = 0,                                   \
 228                 .src_reg = 0,                                   \
 229                 .off   = 0,                                     \
 230                 .imm   = ((FUNC) - BPF_FUNC_unspec) })
 231
 232 /* Raw code statement block */
 233
 234 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM)                  \
 235         ((struct bpf_insn) {                                    \
 236                 .code  = CODE,                                  \
 237                 .dst_reg = DST,                                 \
 238                 .src_reg = SRC,                                 \
 239                 .off   = OFF,                                   \
 240                 .imm   = IMM })
 241
 242 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
 243
 244 #define BPF_LD_IMM64(DST, IMM)                                  \
 245         BPF_LD_IMM64_RAW(DST, 0, IMM)
 246
 247 #define BPF_LD_IMM64_RAW(DST, SRC, IMM)                         \
 248         ((struct bpf_insn) {                                    \
 249                 .code  = BPF_LD | BPF_DW | BPF_IMM,             \
 250                 .dst_reg = DST,                                 \
 251                 .src_reg = SRC,                                 \
 252                 .off   = 0,                                     \
 253                 .imm   = (__u32) (IMM) }),                      \
 254         ((struct bpf_insn) {                                    \
 255                 .code  = 0, /* zero is reserved opcode */       \
 256                 .dst_reg = 0,                                   \
 257                 .src_reg = 0,                                   \
 258                 .off   = 0,                                     \
 259                 .imm   = ((__u64) (IMM)) >> 32 })
 260
 261 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
 262
 263 #define BPF_LD_MAP_FD(DST, MAP_FD)                              \
 264         BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
 265
 266 /* Relative call */
 267
 268 #define BPF_CALL_REL(TGT)                                       \
 269         ((struct bpf_insn) {                                    \
 270                 .code  = BPF_JMP | BPF_CALL,                    \
 271                 .dst_reg = 0,                                   \
 272                 .src_reg = BPF_PSEUDO_CALL,                     \
 273                 .off   = 0,                                     \
 274                 .imm   = TGT })
 275
 276 /* Program exit */
 277
 278 #define BPF_EXIT_INSN()                                         \
 279         ((struct bpf_insn) {                                    \
 280                 .code  = BPF_JMP | BPF_EXIT,                    \
 281                 .dst_reg = 0,                                   \
 282                 .src_reg = 0,                                   \
 283                 .off   = 0,                                     \
 284                 .imm   = 0 })
 285
 286 #endif /* __TOOLS_LINUX_FILTER_H */