Daniel Borkmann | 3f35638 | 2013-12-11 23:43:44 +0100 | [diff] [blame] | 1 | /* |
| 2 | * BPF asm code parser |
| 3 | * |
| 4 | * This program is free software; you can distribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License as published |
| 6 | * by the Free Software Foundation; either version 2 of the License, |
| 7 | * or (at your option) any later version. |
| 8 | * |
| 9 | * Syntax kept close to: |
| 10 | * |
| 11 | * Steven McCanne and Van Jacobson. 1993. The BSD packet filter: a new |
| 12 | * architecture for user-level packet capture. In Proceedings of the |
| 13 | * USENIX Winter 1993 Conference Proceedings on USENIX Winter 1993 |
| 14 | * Conference Proceedings (USENIX'93). USENIX Association, Berkeley, |
| 15 | * CA, USA, 2-2. |
| 16 | * |
| 17 | * Copyright 2013 Daniel Borkmann <borkmann@redhat.com> |
| 18 | * Licensed under the GNU General Public License, version 2.0 (GPLv2) |
| 19 | */ |
| 20 | |
| 21 | %{ |
| 22 | |
| 23 | #include <stdio.h> |
| 24 | #include <string.h> |
| 25 | #include <stdint.h> |
| 26 | #include <stdlib.h> |
| 27 | #include <stdbool.h> |
| 28 | #include <unistd.h> |
| 29 | #include <errno.h> |
| 30 | #include <assert.h> |
| 31 | #include <linux/filter.h> |
| 32 | |
| 33 | #include "bpf_exp.yacc.h" |
| 34 | |
| 35 | enum jmp_type { JTL, JFL, JKL }; |
| 36 | |
| 37 | extern FILE *yyin; |
| 38 | extern int yylex(void); |
| 39 | extern void yyerror(const char *str); |
| 40 | |
| 41 | extern void bpf_asm_compile(FILE *fp, bool cstyle); |
| 42 | static void bpf_set_curr_instr(uint16_t op, uint8_t jt, uint8_t jf, uint32_t k); |
Daniel Borkmann | d207cf4 | 2013-12-16 11:45:01 +0100 | [diff] [blame] | 43 | static void bpf_set_curr_label(char *label); |
| 44 | static void bpf_set_jmp_label(char *label, enum jmp_type type); |
Daniel Borkmann | 3f35638 | 2013-12-11 23:43:44 +0100 | [diff] [blame] | 45 | |
| 46 | %} |
| 47 | |
| 48 | %union { |
| 49 | char *label; |
| 50 | uint32_t number; |
| 51 | } |
| 52 | |
| 53 | %token OP_LDB OP_LDH OP_LD OP_LDX OP_ST OP_STX OP_JMP OP_JEQ OP_JGT OP_JGE |
| 54 | %token OP_JSET OP_ADD OP_SUB OP_MUL OP_DIV OP_AND OP_OR OP_XOR OP_LSH OP_RSH |
| 55 | %token OP_RET OP_TAX OP_TXA OP_LDXB OP_MOD OP_NEG OP_JNEQ OP_JLT OP_JLE OP_LDI |
| 56 | %token OP_LDXI |
| 57 | |
| 58 | %token K_PKT_LEN K_PROTO K_TYPE K_NLATTR K_NLATTR_NEST K_MARK K_QUEUE K_HATYPE |
| 59 | %token K_RXHASH K_CPU K_IFIDX K_VLANT K_VLANP K_POFF |
| 60 | |
| 61 | %token ':' ',' '[' ']' '(' ')' 'x' 'a' '+' 'M' '*' '&' '#' '%' |
| 62 | |
| 63 | %token number label |
| 64 | |
| 65 | %type <label> label |
| 66 | %type <number> number |
| 67 | |
| 68 | %% |
| 69 | |
| 70 | prog |
| 71 | : line |
| 72 | | prog line |
| 73 | ; |
| 74 | |
| 75 | line |
| 76 | : instr |
| 77 | | labelled_instr |
| 78 | ; |
| 79 | |
| 80 | labelled_instr |
| 81 | : labelled instr |
| 82 | ; |
| 83 | |
| 84 | instr |
| 85 | : ldb |
| 86 | | ldh |
| 87 | | ld |
| 88 | | ldi |
| 89 | | ldx |
| 90 | | ldxi |
| 91 | | st |
| 92 | | stx |
| 93 | | jmp |
| 94 | | jeq |
| 95 | | jneq |
| 96 | | jlt |
| 97 | | jle |
| 98 | | jgt |
| 99 | | jge |
| 100 | | jset |
| 101 | | add |
| 102 | | sub |
| 103 | | mul |
| 104 | | div |
| 105 | | mod |
| 106 | | neg |
| 107 | | and |
| 108 | | or |
| 109 | | xor |
| 110 | | lsh |
| 111 | | rsh |
| 112 | | ret |
| 113 | | tax |
| 114 | | txa |
| 115 | ; |
| 116 | |
| 117 | labelled |
| 118 | : label ':' { bpf_set_curr_label($1); } |
| 119 | ; |
| 120 | |
| 121 | ldb |
| 122 | : OP_LDB '[' 'x' '+' number ']' { |
| 123 | bpf_set_curr_instr(BPF_LD | BPF_B | BPF_IND, 0, 0, $5); } |
| 124 | | OP_LDB '[' '%' 'x' '+' number ']' { |
| 125 | bpf_set_curr_instr(BPF_LD | BPF_B | BPF_IND, 0, 0, $6); } |
| 126 | | OP_LDB '[' number ']' { |
| 127 | bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0, $3); } |
| 128 | | OP_LDB K_PROTO { |
| 129 | bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0, |
| 130 | SKF_AD_OFF + SKF_AD_PROTOCOL); } |
| 131 | | OP_LDB K_TYPE { |
| 132 | bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0, |
| 133 | SKF_AD_OFF + SKF_AD_PKTTYPE); } |
| 134 | | OP_LDB K_IFIDX { |
| 135 | bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0, |
| 136 | SKF_AD_OFF + SKF_AD_IFINDEX); } |
| 137 | | OP_LDB K_NLATTR { |
| 138 | bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0, |
| 139 | SKF_AD_OFF + SKF_AD_NLATTR); } |
| 140 | | OP_LDB K_NLATTR_NEST { |
| 141 | bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0, |
| 142 | SKF_AD_OFF + SKF_AD_NLATTR_NEST); } |
| 143 | | OP_LDB K_MARK { |
| 144 | bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0, |
| 145 | SKF_AD_OFF + SKF_AD_MARK); } |
| 146 | | OP_LDB K_QUEUE { |
| 147 | bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0, |
| 148 | SKF_AD_OFF + SKF_AD_QUEUE); } |
| 149 | | OP_LDB K_HATYPE { |
| 150 | bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0, |
| 151 | SKF_AD_OFF + SKF_AD_HATYPE); } |
| 152 | | OP_LDB K_RXHASH { |
| 153 | bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0, |
| 154 | SKF_AD_OFF + SKF_AD_RXHASH); } |
| 155 | | OP_LDB K_CPU { |
| 156 | bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0, |
| 157 | SKF_AD_OFF + SKF_AD_CPU); } |
| 158 | | OP_LDB K_VLANT { |
| 159 | bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0, |
| 160 | SKF_AD_OFF + SKF_AD_VLAN_TAG); } |
| 161 | | OP_LDB K_VLANP { |
| 162 | bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0, |
| 163 | SKF_AD_OFF + SKF_AD_VLAN_TAG_PRESENT); } |
| 164 | | OP_LDB K_POFF { |
| 165 | bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0, |
| 166 | SKF_AD_OFF + SKF_AD_PAY_OFFSET); } |
| 167 | ; |
| 168 | |
| 169 | ldh |
| 170 | : OP_LDH '[' 'x' '+' number ']' { |
| 171 | bpf_set_curr_instr(BPF_LD | BPF_H | BPF_IND, 0, 0, $5); } |
| 172 | | OP_LDH '[' '%' 'x' '+' number ']' { |
| 173 | bpf_set_curr_instr(BPF_LD | BPF_H | BPF_IND, 0, 0, $6); } |
| 174 | | OP_LDH '[' number ']' { |
| 175 | bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, $3); } |
| 176 | | OP_LDH K_PROTO { |
| 177 | bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, |
| 178 | SKF_AD_OFF + SKF_AD_PROTOCOL); } |
| 179 | | OP_LDH K_TYPE { |
| 180 | bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, |
| 181 | SKF_AD_OFF + SKF_AD_PKTTYPE); } |
| 182 | | OP_LDH K_IFIDX { |
| 183 | bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, |
| 184 | SKF_AD_OFF + SKF_AD_IFINDEX); } |
| 185 | | OP_LDH K_NLATTR { |
| 186 | bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, |
| 187 | SKF_AD_OFF + SKF_AD_NLATTR); } |
| 188 | | OP_LDH K_NLATTR_NEST { |
| 189 | bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, |
| 190 | SKF_AD_OFF + SKF_AD_NLATTR_NEST); } |
| 191 | | OP_LDH K_MARK { |
| 192 | bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, |
| 193 | SKF_AD_OFF + SKF_AD_MARK); } |
| 194 | | OP_LDH K_QUEUE { |
| 195 | bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, |
| 196 | SKF_AD_OFF + SKF_AD_QUEUE); } |
| 197 | | OP_LDH K_HATYPE { |
| 198 | bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, |
| 199 | SKF_AD_OFF + SKF_AD_HATYPE); } |
| 200 | | OP_LDH K_RXHASH { |
| 201 | bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, |
| 202 | SKF_AD_OFF + SKF_AD_RXHASH); } |
| 203 | | OP_LDH K_CPU { |
| 204 | bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, |
| 205 | SKF_AD_OFF + SKF_AD_CPU); } |
| 206 | | OP_LDH K_VLANT { |
| 207 | bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, |
| 208 | SKF_AD_OFF + SKF_AD_VLAN_TAG); } |
| 209 | | OP_LDH K_VLANP { |
| 210 | bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, |
| 211 | SKF_AD_OFF + SKF_AD_VLAN_TAG_PRESENT); } |
| 212 | | OP_LDH K_POFF { |
| 213 | bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, |
| 214 | SKF_AD_OFF + SKF_AD_PAY_OFFSET); } |
| 215 | ; |
| 216 | |
| 217 | ldi |
| 218 | : OP_LDI '#' number { |
| 219 | bpf_set_curr_instr(BPF_LD | BPF_IMM, 0, 0, $3); } |
| 220 | | OP_LDI number { |
| 221 | bpf_set_curr_instr(BPF_LD | BPF_IMM, 0, 0, $2); } |
| 222 | ; |
| 223 | |
| 224 | ld |
| 225 | : OP_LD '#' number { |
| 226 | bpf_set_curr_instr(BPF_LD | BPF_IMM, 0, 0, $3); } |
| 227 | | OP_LD K_PKT_LEN { |
| 228 | bpf_set_curr_instr(BPF_LD | BPF_W | BPF_LEN, 0, 0, 0); } |
| 229 | | OP_LD K_PROTO { |
| 230 | bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, |
| 231 | SKF_AD_OFF + SKF_AD_PROTOCOL); } |
| 232 | | OP_LD K_TYPE { |
| 233 | bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, |
| 234 | SKF_AD_OFF + SKF_AD_PKTTYPE); } |
| 235 | | OP_LD K_IFIDX { |
| 236 | bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, |
| 237 | SKF_AD_OFF + SKF_AD_IFINDEX); } |
| 238 | | OP_LD K_NLATTR { |
| 239 | bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, |
| 240 | SKF_AD_OFF + SKF_AD_NLATTR); } |
| 241 | | OP_LD K_NLATTR_NEST { |
| 242 | bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, |
| 243 | SKF_AD_OFF + SKF_AD_NLATTR_NEST); } |
| 244 | | OP_LD K_MARK { |
| 245 | bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, |
| 246 | SKF_AD_OFF + SKF_AD_MARK); } |
| 247 | | OP_LD K_QUEUE { |
| 248 | bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, |
| 249 | SKF_AD_OFF + SKF_AD_QUEUE); } |
| 250 | | OP_LD K_HATYPE { |
| 251 | bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, |
| 252 | SKF_AD_OFF + SKF_AD_HATYPE); } |
| 253 | | OP_LD K_RXHASH { |
| 254 | bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, |
| 255 | SKF_AD_OFF + SKF_AD_RXHASH); } |
| 256 | | OP_LD K_CPU { |
| 257 | bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, |
| 258 | SKF_AD_OFF + SKF_AD_CPU); } |
| 259 | | OP_LD K_VLANT { |
| 260 | bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, |
| 261 | SKF_AD_OFF + SKF_AD_VLAN_TAG); } |
| 262 | | OP_LD K_VLANP { |
| 263 | bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, |
| 264 | SKF_AD_OFF + SKF_AD_VLAN_TAG_PRESENT); } |
| 265 | | OP_LD K_POFF { |
| 266 | bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, |
| 267 | SKF_AD_OFF + SKF_AD_PAY_OFFSET); } |
| 268 | | OP_LD 'M' '[' number ']' { |
| 269 | bpf_set_curr_instr(BPF_LD | BPF_MEM, 0, 0, $4); } |
| 270 | | OP_LD '[' 'x' '+' number ']' { |
| 271 | bpf_set_curr_instr(BPF_LD | BPF_W | BPF_IND, 0, 0, $5); } |
| 272 | | OP_LD '[' '%' 'x' '+' number ']' { |
| 273 | bpf_set_curr_instr(BPF_LD | BPF_W | BPF_IND, 0, 0, $6); } |
| 274 | | OP_LD '[' number ']' { |
| 275 | bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, $3); } |
| 276 | ; |
| 277 | |
| 278 | ldxi |
| 279 | : OP_LDXI '#' number { |
| 280 | bpf_set_curr_instr(BPF_LDX | BPF_IMM, 0, 0, $3); } |
| 281 | | OP_LDXI number { |
| 282 | bpf_set_curr_instr(BPF_LDX | BPF_IMM, 0, 0, $2); } |
| 283 | ; |
| 284 | |
| 285 | ldx |
| 286 | : OP_LDX '#' number { |
| 287 | bpf_set_curr_instr(BPF_LDX | BPF_IMM, 0, 0, $3); } |
| 288 | | OP_LDX K_PKT_LEN { |
| 289 | bpf_set_curr_instr(BPF_LDX | BPF_W | BPF_LEN, 0, 0, 0); } |
| 290 | | OP_LDX 'M' '[' number ']' { |
| 291 | bpf_set_curr_instr(BPF_LDX | BPF_MEM, 0, 0, $4); } |
| 292 | | OP_LDXB number '*' '(' '[' number ']' '&' number ')' { |
| 293 | if ($2 != 4 || $9 != 0xf) { |
| 294 | fprintf(stderr, "ldxb offset not supported!\n"); |
| 295 | exit(0); |
| 296 | } else { |
| 297 | bpf_set_curr_instr(BPF_LDX | BPF_MSH | BPF_B, 0, 0, $6); } } |
| 298 | | OP_LDX number '*' '(' '[' number ']' '&' number ')' { |
| 299 | if ($2 != 4 || $9 != 0xf) { |
| 300 | fprintf(stderr, "ldxb offset not supported!\n"); |
| 301 | exit(0); |
| 302 | } else { |
| 303 | bpf_set_curr_instr(BPF_LDX | BPF_MSH | BPF_B, 0, 0, $6); } } |
| 304 | ; |
| 305 | |
| 306 | st |
| 307 | : OP_ST 'M' '[' number ']' { |
| 308 | bpf_set_curr_instr(BPF_ST, 0, 0, $4); } |
| 309 | ; |
| 310 | |
| 311 | stx |
| 312 | : OP_STX 'M' '[' number ']' { |
| 313 | bpf_set_curr_instr(BPF_STX, 0, 0, $4); } |
| 314 | ; |
| 315 | |
| 316 | jmp |
| 317 | : OP_JMP label { |
| 318 | bpf_set_jmp_label($2, JKL); |
| 319 | bpf_set_curr_instr(BPF_JMP | BPF_JA, 0, 0, 0); } |
| 320 | ; |
| 321 | |
| 322 | jeq |
| 323 | : OP_JEQ '#' number ',' label ',' label { |
| 324 | bpf_set_jmp_label($5, JTL); |
| 325 | bpf_set_jmp_label($7, JFL); |
| 326 | bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_K, 0, 0, $3); } |
| 327 | | OP_JEQ 'x' ',' label ',' label { |
| 328 | bpf_set_jmp_label($4, JTL); |
| 329 | bpf_set_jmp_label($6, JFL); |
| 330 | bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_X, 0, 0, 0); } |
| 331 | | OP_JEQ '%' 'x' ',' label ',' label { |
| 332 | bpf_set_jmp_label($5, JTL); |
| 333 | bpf_set_jmp_label($7, JFL); |
| 334 | bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_X, 0, 0, 0); } |
| 335 | | OP_JEQ '#' number ',' label { |
| 336 | bpf_set_jmp_label($5, JTL); |
| 337 | bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_K, 0, 0, $3); } |
| 338 | | OP_JEQ 'x' ',' label { |
| 339 | bpf_set_jmp_label($4, JTL); |
| 340 | bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_X, 0, 0, 0); } |
| 341 | | OP_JEQ '%' 'x' ',' label { |
| 342 | bpf_set_jmp_label($5, JTL); |
| 343 | bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_X, 0, 0, 0); } |
| 344 | ; |
| 345 | |
| 346 | jneq |
| 347 | : OP_JNEQ '#' number ',' label { |
| 348 | bpf_set_jmp_label($5, JFL); |
| 349 | bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_K, 0, 0, $3); } |
| 350 | | OP_JNEQ 'x' ',' label { |
| 351 | bpf_set_jmp_label($4, JFL); |
| 352 | bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_X, 0, 0, 0); } |
| 353 | | OP_JNEQ '%' 'x' ',' label { |
| 354 | bpf_set_jmp_label($5, JFL); |
| 355 | bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_X, 0, 0, 0); } |
| 356 | ; |
| 357 | |
| 358 | jlt |
| 359 | : OP_JLT '#' number ',' label { |
| 360 | bpf_set_jmp_label($5, JFL); |
| 361 | bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_K, 0, 0, $3); } |
| 362 | | OP_JLT 'x' ',' label { |
| 363 | bpf_set_jmp_label($4, JFL); |
| 364 | bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_X, 0, 0, 0); } |
| 365 | | OP_JLT '%' 'x' ',' label { |
| 366 | bpf_set_jmp_label($5, JFL); |
| 367 | bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_X, 0, 0, 0); } |
| 368 | ; |
| 369 | |
| 370 | jle |
| 371 | : OP_JLE '#' number ',' label { |
| 372 | bpf_set_jmp_label($5, JFL); |
| 373 | bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_K, 0, 0, $3); } |
| 374 | | OP_JLE 'x' ',' label { |
| 375 | bpf_set_jmp_label($4, JFL); |
| 376 | bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_X, 0, 0, 0); } |
| 377 | | OP_JLE '%' 'x' ',' label { |
| 378 | bpf_set_jmp_label($5, JFL); |
| 379 | bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_X, 0, 0, 0); } |
| 380 | ; |
| 381 | |
| 382 | jgt |
| 383 | : OP_JGT '#' number ',' label ',' label { |
| 384 | bpf_set_jmp_label($5, JTL); |
| 385 | bpf_set_jmp_label($7, JFL); |
| 386 | bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_K, 0, 0, $3); } |
| 387 | | OP_JGT 'x' ',' label ',' label { |
| 388 | bpf_set_jmp_label($4, JTL); |
| 389 | bpf_set_jmp_label($6, JFL); |
| 390 | bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_X, 0, 0, 0); } |
| 391 | | OP_JGT '%' 'x' ',' label ',' label { |
| 392 | bpf_set_jmp_label($5, JTL); |
| 393 | bpf_set_jmp_label($7, JFL); |
| 394 | bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_X, 0, 0, 0); } |
| 395 | | OP_JGT '#' number ',' label { |
| 396 | bpf_set_jmp_label($5, JTL); |
| 397 | bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_K, 0, 0, $3); } |
| 398 | | OP_JGT 'x' ',' label { |
| 399 | bpf_set_jmp_label($4, JTL); |
| 400 | bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_X, 0, 0, 0); } |
| 401 | | OP_JGT '%' 'x' ',' label { |
| 402 | bpf_set_jmp_label($5, JTL); |
| 403 | bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_X, 0, 0, 0); } |
| 404 | ; |
| 405 | |
| 406 | jge |
| 407 | : OP_JGE '#' number ',' label ',' label { |
| 408 | bpf_set_jmp_label($5, JTL); |
| 409 | bpf_set_jmp_label($7, JFL); |
| 410 | bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_K, 0, 0, $3); } |
| 411 | | OP_JGE 'x' ',' label ',' label { |
| 412 | bpf_set_jmp_label($4, JTL); |
| 413 | bpf_set_jmp_label($6, JFL); |
| 414 | bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_X, 0, 0, 0); } |
| 415 | | OP_JGE '%' 'x' ',' label ',' label { |
| 416 | bpf_set_jmp_label($5, JTL); |
| 417 | bpf_set_jmp_label($7, JFL); |
| 418 | bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_X, 0, 0, 0); } |
| 419 | | OP_JGE '#' number ',' label { |
| 420 | bpf_set_jmp_label($5, JTL); |
| 421 | bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_K, 0, 0, $3); } |
| 422 | | OP_JGE 'x' ',' label { |
| 423 | bpf_set_jmp_label($4, JTL); |
| 424 | bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_X, 0, 0, 0); } |
| 425 | | OP_JGE '%' 'x' ',' label { |
| 426 | bpf_set_jmp_label($5, JTL); |
| 427 | bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_X, 0, 0, 0); } |
| 428 | ; |
| 429 | |
| 430 | jset |
| 431 | : OP_JSET '#' number ',' label ',' label { |
| 432 | bpf_set_jmp_label($5, JTL); |
| 433 | bpf_set_jmp_label($7, JFL); |
| 434 | bpf_set_curr_instr(BPF_JMP | BPF_JSET | BPF_K, 0, 0, $3); } |
| 435 | | OP_JSET 'x' ',' label ',' label { |
| 436 | bpf_set_jmp_label($4, JTL); |
| 437 | bpf_set_jmp_label($6, JFL); |
| 438 | bpf_set_curr_instr(BPF_JMP | BPF_JSET | BPF_X, 0, 0, 0); } |
| 439 | | OP_JSET '%' 'x' ',' label ',' label { |
| 440 | bpf_set_jmp_label($5, JTL); |
| 441 | bpf_set_jmp_label($7, JFL); |
| 442 | bpf_set_curr_instr(BPF_JMP | BPF_JSET | BPF_X, 0, 0, 0); } |
| 443 | | OP_JSET '#' number ',' label { |
| 444 | bpf_set_jmp_label($5, JTL); |
| 445 | bpf_set_curr_instr(BPF_JMP | BPF_JSET | BPF_K, 0, 0, $3); } |
| 446 | | OP_JSET 'x' ',' label { |
| 447 | bpf_set_jmp_label($4, JTL); |
| 448 | bpf_set_curr_instr(BPF_JMP | BPF_JSET | BPF_X, 0, 0, 0); } |
| 449 | | OP_JSET '%' 'x' ',' label { |
| 450 | bpf_set_jmp_label($5, JTL); |
| 451 | bpf_set_curr_instr(BPF_JMP | BPF_JSET | BPF_X, 0, 0, 0); } |
| 452 | ; |
| 453 | |
| 454 | add |
| 455 | : OP_ADD '#' number { |
| 456 | bpf_set_curr_instr(BPF_ALU | BPF_ADD | BPF_K, 0, 0, $3); } |
| 457 | | OP_ADD 'x' { |
| 458 | bpf_set_curr_instr(BPF_ALU | BPF_ADD | BPF_X, 0, 0, 0); } |
| 459 | | OP_ADD '%' 'x' { |
| 460 | bpf_set_curr_instr(BPF_ALU | BPF_ADD | BPF_X, 0, 0, 0); } |
| 461 | ; |
| 462 | |
| 463 | sub |
| 464 | : OP_SUB '#' number { |
| 465 | bpf_set_curr_instr(BPF_ALU | BPF_SUB | BPF_K, 0, 0, $3); } |
| 466 | | OP_SUB 'x' { |
| 467 | bpf_set_curr_instr(BPF_ALU | BPF_SUB | BPF_X, 0, 0, 0); } |
| 468 | | OP_SUB '%' 'x' { |
| 469 | bpf_set_curr_instr(BPF_ALU | BPF_SUB | BPF_X, 0, 0, 0); } |
| 470 | ; |
| 471 | |
| 472 | mul |
| 473 | : OP_MUL '#' number { |
| 474 | bpf_set_curr_instr(BPF_ALU | BPF_MUL | BPF_K, 0, 0, $3); } |
| 475 | | OP_MUL 'x' { |
| 476 | bpf_set_curr_instr(BPF_ALU | BPF_MUL | BPF_X, 0, 0, 0); } |
| 477 | | OP_MUL '%' 'x' { |
| 478 | bpf_set_curr_instr(BPF_ALU | BPF_MUL | BPF_X, 0, 0, 0); } |
| 479 | ; |
| 480 | |
| 481 | div |
| 482 | : OP_DIV '#' number { |
| 483 | bpf_set_curr_instr(BPF_ALU | BPF_DIV | BPF_K, 0, 0, $3); } |
| 484 | | OP_DIV 'x' { |
| 485 | bpf_set_curr_instr(BPF_ALU | BPF_DIV | BPF_X, 0, 0, 0); } |
| 486 | | OP_DIV '%' 'x' { |
| 487 | bpf_set_curr_instr(BPF_ALU | BPF_DIV | BPF_X, 0, 0, 0); } |
| 488 | ; |
| 489 | |
| 490 | mod |
| 491 | : OP_MOD '#' number { |
| 492 | bpf_set_curr_instr(BPF_ALU | BPF_MOD | BPF_K, 0, 0, $3); } |
| 493 | | OP_MOD 'x' { |
| 494 | bpf_set_curr_instr(BPF_ALU | BPF_MOD | BPF_X, 0, 0, 0); } |
| 495 | | OP_MOD '%' 'x' { |
| 496 | bpf_set_curr_instr(BPF_ALU | BPF_MOD | BPF_X, 0, 0, 0); } |
| 497 | ; |
| 498 | |
| 499 | neg |
| 500 | : OP_NEG { |
| 501 | bpf_set_curr_instr(BPF_ALU | BPF_NEG, 0, 0, 0); } |
| 502 | ; |
| 503 | |
| 504 | and |
| 505 | : OP_AND '#' number { |
| 506 | bpf_set_curr_instr(BPF_ALU | BPF_AND | BPF_K, 0, 0, $3); } |
| 507 | | OP_AND 'x' { |
| 508 | bpf_set_curr_instr(BPF_ALU | BPF_AND | BPF_X, 0, 0, 0); } |
| 509 | | OP_AND '%' 'x' { |
| 510 | bpf_set_curr_instr(BPF_ALU | BPF_AND | BPF_X, 0, 0, 0); } |
| 511 | ; |
| 512 | |
| 513 | or |
| 514 | : OP_OR '#' number { |
| 515 | bpf_set_curr_instr(BPF_ALU | BPF_OR | BPF_K, 0, 0, $3); } |
| 516 | | OP_OR 'x' { |
| 517 | bpf_set_curr_instr(BPF_ALU | BPF_OR | BPF_X, 0, 0, 0); } |
| 518 | | OP_OR '%' 'x' { |
| 519 | bpf_set_curr_instr(BPF_ALU | BPF_OR | BPF_X, 0, 0, 0); } |
| 520 | ; |
| 521 | |
| 522 | xor |
| 523 | : OP_XOR '#' number { |
| 524 | bpf_set_curr_instr(BPF_ALU | BPF_XOR | BPF_K, 0, 0, $3); } |
| 525 | | OP_XOR 'x' { |
| 526 | bpf_set_curr_instr(BPF_ALU | BPF_XOR | BPF_X, 0, 0, 0); } |
| 527 | | OP_XOR '%' 'x' { |
| 528 | bpf_set_curr_instr(BPF_ALU | BPF_XOR | BPF_X, 0, 0, 0); } |
| 529 | ; |
| 530 | |
| 531 | lsh |
| 532 | : OP_LSH '#' number { |
| 533 | bpf_set_curr_instr(BPF_ALU | BPF_LSH | BPF_K, 0, 0, $3); } |
| 534 | | OP_LSH 'x' { |
| 535 | bpf_set_curr_instr(BPF_ALU | BPF_LSH | BPF_X, 0, 0, 0); } |
| 536 | | OP_LSH '%' 'x' { |
| 537 | bpf_set_curr_instr(BPF_ALU | BPF_LSH | BPF_X, 0, 0, 0); } |
| 538 | ; |
| 539 | |
| 540 | rsh |
| 541 | : OP_RSH '#' number { |
| 542 | bpf_set_curr_instr(BPF_ALU | BPF_RSH | BPF_K, 0, 0, $3); } |
| 543 | | OP_RSH 'x' { |
| 544 | bpf_set_curr_instr(BPF_ALU | BPF_RSH | BPF_X, 0, 0, 0); } |
| 545 | | OP_RSH '%' 'x' { |
| 546 | bpf_set_curr_instr(BPF_ALU | BPF_RSH | BPF_X, 0, 0, 0); } |
| 547 | ; |
| 548 | |
| 549 | ret |
| 550 | : OP_RET 'a' { |
| 551 | bpf_set_curr_instr(BPF_RET | BPF_A, 0, 0, 0); } |
| 552 | | OP_RET '%' 'a' { |
| 553 | bpf_set_curr_instr(BPF_RET | BPF_A, 0, 0, 0); } |
| 554 | | OP_RET 'x' { |
| 555 | bpf_set_curr_instr(BPF_RET | BPF_X, 0, 0, 0); } |
| 556 | | OP_RET '%' 'x' { |
| 557 | bpf_set_curr_instr(BPF_RET | BPF_X, 0, 0, 0); } |
| 558 | | OP_RET '#' number { |
| 559 | bpf_set_curr_instr(BPF_RET | BPF_K, 0, 0, $3); } |
| 560 | ; |
| 561 | |
| 562 | tax |
| 563 | : OP_TAX { |
| 564 | bpf_set_curr_instr(BPF_MISC | BPF_TAX, 0, 0, 0); } |
| 565 | ; |
| 566 | |
| 567 | txa |
| 568 | : OP_TXA { |
| 569 | bpf_set_curr_instr(BPF_MISC | BPF_TXA, 0, 0, 0); } |
| 570 | ; |
| 571 | |
| 572 | %% |
| 573 | |
| 574 | static int curr_instr = 0; |
| 575 | static struct sock_filter out[BPF_MAXINSNS]; |
Daniel Borkmann | d207cf4 | 2013-12-16 11:45:01 +0100 | [diff] [blame] | 576 | static char **labels, **labels_jt, **labels_jf, **labels_k; |
Daniel Borkmann | 3f35638 | 2013-12-11 23:43:44 +0100 | [diff] [blame] | 577 | |
| 578 | static void bpf_assert_max(void) |
| 579 | { |
| 580 | if (curr_instr >= BPF_MAXINSNS) { |
| 581 | fprintf(stderr, "only max %u insns allowed!\n", BPF_MAXINSNS); |
| 582 | exit(0); |
| 583 | } |
| 584 | } |
| 585 | |
| 586 | static void bpf_set_curr_instr(uint16_t code, uint8_t jt, uint8_t jf, |
| 587 | uint32_t k) |
| 588 | { |
| 589 | bpf_assert_max(); |
| 590 | out[curr_instr].code = code; |
| 591 | out[curr_instr].jt = jt; |
| 592 | out[curr_instr].jf = jf; |
| 593 | out[curr_instr].k = k; |
| 594 | curr_instr++; |
| 595 | } |
| 596 | |
Daniel Borkmann | d207cf4 | 2013-12-16 11:45:01 +0100 | [diff] [blame] | 597 | static void bpf_set_curr_label(char *label) |
Daniel Borkmann | 3f35638 | 2013-12-11 23:43:44 +0100 | [diff] [blame] | 598 | { |
| 599 | bpf_assert_max(); |
Daniel Borkmann | d207cf4 | 2013-12-16 11:45:01 +0100 | [diff] [blame] | 600 | labels[curr_instr] = label; |
Daniel Borkmann | 3f35638 | 2013-12-11 23:43:44 +0100 | [diff] [blame] | 601 | } |
| 602 | |
Daniel Borkmann | d207cf4 | 2013-12-16 11:45:01 +0100 | [diff] [blame] | 603 | static void bpf_set_jmp_label(char *label, enum jmp_type type) |
Daniel Borkmann | 3f35638 | 2013-12-11 23:43:44 +0100 | [diff] [blame] | 604 | { |
| 605 | bpf_assert_max(); |
| 606 | switch (type) { |
| 607 | case JTL: |
| 608 | labels_jt[curr_instr] = label; |
| 609 | break; |
| 610 | case JFL: |
| 611 | labels_jf[curr_instr] = label; |
| 612 | break; |
| 613 | case JKL: |
| 614 | labels_k[curr_instr] = label; |
| 615 | break; |
| 616 | } |
| 617 | } |
| 618 | |
| 619 | static int bpf_find_insns_offset(const char *label) |
| 620 | { |
| 621 | int i, max = curr_instr, ret = -ENOENT; |
| 622 | |
| 623 | for (i = 0; i < max; i++) { |
| 624 | if (labels[i] && !strcmp(label, labels[i])) { |
| 625 | ret = i; |
| 626 | break; |
| 627 | } |
| 628 | } |
| 629 | |
| 630 | if (ret == -ENOENT) { |
| 631 | fprintf(stderr, "no such label \'%s\'!\n", label); |
| 632 | exit(0); |
| 633 | } |
| 634 | |
| 635 | return ret; |
| 636 | } |
| 637 | |
| 638 | static void bpf_stage_1_insert_insns(void) |
| 639 | { |
| 640 | yyparse(); |
| 641 | } |
| 642 | |
| 643 | static void bpf_reduce_k_jumps(void) |
| 644 | { |
| 645 | int i; |
| 646 | |
| 647 | for (i = 0; i < curr_instr; i++) { |
| 648 | if (labels_k[i]) { |
| 649 | int off = bpf_find_insns_offset(labels_k[i]); |
| 650 | out[i].k = (uint32_t) (off - i - 1); |
| 651 | } |
| 652 | } |
| 653 | } |
| 654 | |
| 655 | static void bpf_reduce_jt_jumps(void) |
| 656 | { |
| 657 | int i; |
| 658 | |
| 659 | for (i = 0; i < curr_instr; i++) { |
| 660 | if (labels_jt[i]) { |
| 661 | int off = bpf_find_insns_offset(labels_jt[i]); |
| 662 | out[i].jt = (uint8_t) (off - i -1); |
| 663 | } |
| 664 | } |
| 665 | } |
| 666 | |
| 667 | static void bpf_reduce_jf_jumps(void) |
| 668 | { |
| 669 | int i; |
| 670 | |
| 671 | for (i = 0; i < curr_instr; i++) { |
| 672 | if (labels_jf[i]) { |
| 673 | int off = bpf_find_insns_offset(labels_jf[i]); |
| 674 | out[i].jf = (uint8_t) (off - i - 1); |
| 675 | } |
| 676 | } |
| 677 | } |
| 678 | |
| 679 | static void bpf_stage_2_reduce_labels(void) |
| 680 | { |
| 681 | bpf_reduce_k_jumps(); |
| 682 | bpf_reduce_jt_jumps(); |
| 683 | bpf_reduce_jf_jumps(); |
| 684 | } |
| 685 | |
| 686 | static void bpf_pretty_print_c(void) |
| 687 | { |
| 688 | int i; |
| 689 | |
| 690 | for (i = 0; i < curr_instr; i++) |
| 691 | printf("{ %#04x, %2u, %2u, %#010x },\n", out[i].code, |
| 692 | out[i].jt, out[i].jf, out[i].k); |
| 693 | } |
| 694 | |
| 695 | static void bpf_pretty_print(void) |
| 696 | { |
| 697 | int i; |
| 698 | |
| 699 | printf("%u,", curr_instr); |
| 700 | for (i = 0; i < curr_instr; i++) |
| 701 | printf("%u %u %u %u,", out[i].code, |
| 702 | out[i].jt, out[i].jf, out[i].k); |
| 703 | printf("\n"); |
| 704 | } |
| 705 | |
| 706 | static void bpf_init(void) |
| 707 | { |
| 708 | memset(out, 0, sizeof(out)); |
| 709 | |
| 710 | labels = calloc(BPF_MAXINSNS, sizeof(*labels)); |
| 711 | assert(labels); |
| 712 | labels_jt = calloc(BPF_MAXINSNS, sizeof(*labels_jt)); |
| 713 | assert(labels_jt); |
| 714 | labels_jf = calloc(BPF_MAXINSNS, sizeof(*labels_jf)); |
| 715 | assert(labels_jf); |
| 716 | labels_k = calloc(BPF_MAXINSNS, sizeof(*labels_k)); |
| 717 | assert(labels_k); |
| 718 | } |
| 719 | |
Daniel Borkmann | d207cf4 | 2013-12-16 11:45:01 +0100 | [diff] [blame] | 720 | static void bpf_destroy_labels(void) |
| 721 | { |
| 722 | int i; |
| 723 | |
| 724 | for (i = 0; i < curr_instr; i++) { |
| 725 | free(labels_jf[i]); |
| 726 | free(labels_jt[i]); |
| 727 | free(labels_k[i]); |
| 728 | free(labels[i]); |
| 729 | } |
| 730 | } |
| 731 | |
Daniel Borkmann | 3f35638 | 2013-12-11 23:43:44 +0100 | [diff] [blame] | 732 | static void bpf_destroy(void) |
| 733 | { |
Daniel Borkmann | d207cf4 | 2013-12-16 11:45:01 +0100 | [diff] [blame] | 734 | bpf_destroy_labels(); |
Daniel Borkmann | 3f35638 | 2013-12-11 23:43:44 +0100 | [diff] [blame] | 735 | free(labels_jt); |
| 736 | free(labels_jf); |
| 737 | free(labels_k); |
Daniel Borkmann | d207cf4 | 2013-12-16 11:45:01 +0100 | [diff] [blame] | 738 | free(labels); |
Daniel Borkmann | 3f35638 | 2013-12-11 23:43:44 +0100 | [diff] [blame] | 739 | } |
| 740 | |
| 741 | void bpf_asm_compile(FILE *fp, bool cstyle) |
| 742 | { |
| 743 | yyin = fp; |
| 744 | |
| 745 | bpf_init(); |
| 746 | bpf_stage_1_insert_insns(); |
| 747 | bpf_stage_2_reduce_labels(); |
| 748 | bpf_destroy(); |
| 749 | |
| 750 | if (cstyle) |
| 751 | bpf_pretty_print_c(); |
| 752 | else |
| 753 | bpf_pretty_print(); |
| 754 | |
| 755 | if (fp != stdin) |
| 756 | fclose(yyin); |
| 757 | } |
| 758 | |
| 759 | void yyerror(const char *str) |
| 760 | { |
| 761 | exit(1); |
| 762 | } |