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 /* 173 * Atomic operations: 174 * 175 * BPF_ADD *(uint *) (dst_reg + off16) += src_reg 176 */ 177 178 #define BPF_ATOMIC_OP(SIZE, OP, DST, SRC, OFF) \ 179 ((struct bpf_insn) { \ 180 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_ATOMIC, \ 181 .dst_reg = DST, \ 182 .src_reg = SRC, \ 183 .off = OFF, \ 184 .imm = OP }) 185 186 /* Legacy alias */ 187 #define BPF_STX_XADD(SIZE, DST, SRC, OFF) BPF_ATOMIC_OP(SIZE, BPF_ADD, DST, SRC, OFF) 188 189 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */ 190 191 #define BPF_ST_MEM(SIZE, DST, OFF, IMM) \ 192 ((struct bpf_insn) { \ 193 .code = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM, \ 194 .dst_reg = DST, \ 195 .src_reg = 0, \ 196 .off = OFF, \ 197 .imm = IMM }) 198 199 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */ 200 201 #define BPF_JMP_REG(OP, DST, SRC, OFF) \ 202 ((struct bpf_insn) { \ 203 .code = BPF_JMP | BPF_OP(OP) | BPF_X, \ 204 .dst_reg = DST, \ 205 .src_reg = SRC, \ 206 .off = OFF, \ 207 .imm = 0 }) 208 209 /* Like BPF_JMP_REG, but with 32-bit wide operands for comparison. */ 210 211 #define BPF_JMP32_REG(OP, DST, SRC, OFF) \ 212 ((struct bpf_insn) { \ 213 .code = BPF_JMP32 | BPF_OP(OP) | BPF_X, \ 214 .dst_reg = DST, \ 215 .src_reg = SRC, \ 216 .off = OFF, \ 217 .imm = 0 }) 218 219 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */ 220 221 #define BPF_JMP_IMM(OP, DST, IMM, OFF) \ 222 ((struct bpf_insn) { \ 223 .code = BPF_JMP | BPF_OP(OP) | BPF_K, \ 224 .dst_reg = DST, \ 225 .src_reg = 0, \ 226 .off = OFF, \ 227 .imm = IMM }) 228 229 /* Like BPF_JMP_IMM, but with 32-bit wide operands for comparison. */ 230 231 #define BPF_JMP32_IMM(OP, DST, IMM, OFF) \ 232 ((struct bpf_insn) { \ 233 .code = BPF_JMP32 | BPF_OP(OP) | BPF_K, \ 234 .dst_reg = DST, \ 235 .src_reg = 0, \ 236 .off = OFF, \ 237 .imm = IMM }) 238 239 /* Unconditional jumps, goto pc + off16 */ 240 241 #define BPF_JMP_A(OFF) \ 242 ((struct bpf_insn) { \ 243 .code = BPF_JMP | BPF_JA, \ 244 .dst_reg = 0, \ 245 .src_reg = 0, \ 246 .off = OFF, \ 247 .imm = 0 }) 248 249 /* Function call */ 250 251 #define BPF_EMIT_CALL(FUNC) \ 252 ((struct bpf_insn) { \ 253 .code = BPF_JMP | BPF_CALL, \ 254 .dst_reg = 0, \ 255 .src_reg = 0, \ 256 .off = 0, \ 257 .imm = ((FUNC) - BPF_FUNC_unspec) }) 258 259 /* Raw code statement block */ 260 261 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM) \ 262 ((struct bpf_insn) { \ 263 .code = CODE, \ 264 .dst_reg = DST, \ 265 .src_reg = SRC, \ 266 .off = OFF, \ 267 .imm = IMM }) 268 269 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */ 270 271 #define BPF_LD_IMM64(DST, IMM) \ 272 BPF_LD_IMM64_RAW(DST, 0, IMM) 273 274 #define BPF_LD_IMM64_RAW(DST, SRC, IMM) \ 275 ((struct bpf_insn) { \ 276 .code = BPF_LD | BPF_DW | BPF_IMM, \ 277 .dst_reg = DST, \ 278 .src_reg = SRC, \ 279 .off = 0, \ 280 .imm = (__u32) (IMM) }), \ 281 ((struct bpf_insn) { \ 282 .code = 0, /* zero is reserved opcode */ \ 283 .dst_reg = 0, \ 284 .src_reg = 0, \ 285 .off = 0, \ 286 .imm = ((__u64) (IMM)) >> 32 }) 287 288 #define BPF_LD_IMM64_RAW_FULL(DST, SRC, OFF1, OFF2, IMM1, IMM2) \ 289 ((struct bpf_insn) { \ 290 .code = BPF_LD | BPF_DW | BPF_IMM, \ 291 .dst_reg = DST, \ 292 .src_reg = SRC, \ 293 .off = OFF1, \ 294 .imm = IMM1 }), \ 295 ((struct bpf_insn) { \ 296 .code = 0, /* zero is reserved opcode */ \ 297 .dst_reg = 0, \ 298 .src_reg = 0, \ 299 .off = OFF2, \ 300 .imm = IMM2 }) 301 302 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */ 303 304 #define BPF_LD_MAP_FD(DST, MAP_FD) \ 305 BPF_LD_IMM64_RAW_FULL(DST, BPF_PSEUDO_MAP_FD, 0, 0, \ 306 MAP_FD, 0) 307 308 #define BPF_LD_MAP_VALUE(DST, MAP_FD, VALUE_OFF) \ 309 BPF_LD_IMM64_RAW_FULL(DST, BPF_PSEUDO_MAP_VALUE, 0, 0, \ 310 MAP_FD, VALUE_OFF) 311 312 /* Relative call */ 313 314 #define BPF_CALL_REL(TGT) \ 315 ((struct bpf_insn) { \ 316 .code = BPF_JMP | BPF_CALL, \ 317 .dst_reg = 0, \ 318 .src_reg = BPF_PSEUDO_CALL, \ 319 .off = 0, \ 320 .imm = TGT }) 321 322 /* Program exit */ 323 324 #define BPF_EXIT_INSN() \ 325 ((struct bpf_insn) { \ 326 .code = BPF_JMP | BPF_EXIT, \ 327 .dst_reg = 0, \ 328 .src_reg = 0, \ 329 .off = 0, \ 330 .imm = 0 }) 331 332 #endif /* __TOOLS_LINUX_FILTER_H */ 333