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.
9 * Syntax kept close to:
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,
17 * Copyright 2013 Daniel Borkmann <borkmann@redhat.com>
18 * Licensed under the GNU General Public License, version 2.0 (GPLv2)
31 #include <linux/filter.h>
33 #include "bpf_exp.yacc.h"
35 enum jmp_type { JTL, JFL, JKL };
38 extern int yylex(void);
39 extern void yyerror(const char *str);
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);
43 static void bpf_set_curr_label(char *label);
44 static void bpf_set_jmp_label(char *label, enum jmp_type type);
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
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 K_RAND
61 %token ':' ',' '[' ']' '(' ')' 'x' 'a' '+' 'M' '*' '&' '#' '%'
118 : label ':' { bpf_set_curr_label($1); }
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); }
129 bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
130 SKF_AD_OFF + SKF_AD_PROTOCOL); }
132 bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
133 SKF_AD_OFF + SKF_AD_PKTTYPE); }
135 bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
136 SKF_AD_OFF + SKF_AD_IFINDEX); }
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); }
144 bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
145 SKF_AD_OFF + SKF_AD_MARK); }
147 bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
148 SKF_AD_OFF + SKF_AD_QUEUE); }
150 bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
151 SKF_AD_OFF + SKF_AD_HATYPE); }
153 bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
154 SKF_AD_OFF + SKF_AD_RXHASH); }
156 bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
157 SKF_AD_OFF + SKF_AD_CPU); }
159 bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
160 SKF_AD_OFF + SKF_AD_VLAN_TAG); }
162 bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
163 SKF_AD_OFF + SKF_AD_VLAN_TAG_PRESENT); }
165 bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
166 SKF_AD_OFF + SKF_AD_PAY_OFFSET); }
168 bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
169 SKF_AD_OFF + SKF_AD_RANDOM); }
173 : OP_LDH '[' 'x' '+' number ']' {
174 bpf_set_curr_instr(BPF_LD | BPF_H | BPF_IND, 0, 0, $5); }
175 | OP_LDH '[' '%' 'x' '+' number ']' {
176 bpf_set_curr_instr(BPF_LD | BPF_H | BPF_IND, 0, 0, $6); }
177 | OP_LDH '[' number ']' {
178 bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, $3); }
180 bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
181 SKF_AD_OFF + SKF_AD_PROTOCOL); }
183 bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
184 SKF_AD_OFF + SKF_AD_PKTTYPE); }
186 bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
187 SKF_AD_OFF + SKF_AD_IFINDEX); }
189 bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
190 SKF_AD_OFF + SKF_AD_NLATTR); }
191 | OP_LDH K_NLATTR_NEST {
192 bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
193 SKF_AD_OFF + SKF_AD_NLATTR_NEST); }
195 bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
196 SKF_AD_OFF + SKF_AD_MARK); }
198 bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
199 SKF_AD_OFF + SKF_AD_QUEUE); }
201 bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
202 SKF_AD_OFF + SKF_AD_HATYPE); }
204 bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
205 SKF_AD_OFF + SKF_AD_RXHASH); }
207 bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
208 SKF_AD_OFF + SKF_AD_CPU); }
210 bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
211 SKF_AD_OFF + SKF_AD_VLAN_TAG); }
213 bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
214 SKF_AD_OFF + SKF_AD_VLAN_TAG_PRESENT); }
216 bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
217 SKF_AD_OFF + SKF_AD_PAY_OFFSET); }
219 bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
220 SKF_AD_OFF + SKF_AD_RANDOM); }
224 : OP_LDI '#' number {
225 bpf_set_curr_instr(BPF_LD | BPF_IMM, 0, 0, $3); }
227 bpf_set_curr_instr(BPF_LD | BPF_IMM, 0, 0, $2); }
232 bpf_set_curr_instr(BPF_LD | BPF_IMM, 0, 0, $3); }
234 bpf_set_curr_instr(BPF_LD | BPF_W | BPF_LEN, 0, 0, 0); }
236 bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
237 SKF_AD_OFF + SKF_AD_PROTOCOL); }
239 bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
240 SKF_AD_OFF + SKF_AD_PKTTYPE); }
242 bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
243 SKF_AD_OFF + SKF_AD_IFINDEX); }
245 bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
246 SKF_AD_OFF + SKF_AD_NLATTR); }
247 | OP_LD K_NLATTR_NEST {
248 bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
249 SKF_AD_OFF + SKF_AD_NLATTR_NEST); }
251 bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
252 SKF_AD_OFF + SKF_AD_MARK); }
254 bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
255 SKF_AD_OFF + SKF_AD_QUEUE); }
257 bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
258 SKF_AD_OFF + SKF_AD_HATYPE); }
260 bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
261 SKF_AD_OFF + SKF_AD_RXHASH); }
263 bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
264 SKF_AD_OFF + SKF_AD_CPU); }
266 bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
267 SKF_AD_OFF + SKF_AD_VLAN_TAG); }
269 bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
270 SKF_AD_OFF + SKF_AD_VLAN_TAG_PRESENT); }
272 bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
273 SKF_AD_OFF + SKF_AD_PAY_OFFSET); }
275 bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
276 SKF_AD_OFF + SKF_AD_RANDOM); }
277 | OP_LD 'M' '[' number ']' {
278 bpf_set_curr_instr(BPF_LD | BPF_MEM, 0, 0, $4); }
279 | OP_LD '[' 'x' '+' number ']' {
280 bpf_set_curr_instr(BPF_LD | BPF_W | BPF_IND, 0, 0, $5); }
281 | OP_LD '[' '%' 'x' '+' number ']' {
282 bpf_set_curr_instr(BPF_LD | BPF_W | BPF_IND, 0, 0, $6); }
283 | OP_LD '[' number ']' {
284 bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, $3); }
288 : OP_LDXI '#' number {
289 bpf_set_curr_instr(BPF_LDX | BPF_IMM, 0, 0, $3); }
291 bpf_set_curr_instr(BPF_LDX | BPF_IMM, 0, 0, $2); }
295 : OP_LDX '#' number {
296 bpf_set_curr_instr(BPF_LDX | BPF_IMM, 0, 0, $3); }
298 bpf_set_curr_instr(BPF_LDX | BPF_W | BPF_LEN, 0, 0, 0); }
299 | OP_LDX 'M' '[' number ']' {
300 bpf_set_curr_instr(BPF_LDX | BPF_MEM, 0, 0, $4); }
301 | OP_LDXB number '*' '(' '[' number ']' '&' number ')' {
302 if ($2 != 4 || $9 != 0xf) {
303 fprintf(stderr, "ldxb offset not supported!\n");
306 bpf_set_curr_instr(BPF_LDX | BPF_MSH | BPF_B, 0, 0, $6); } }
307 | OP_LDX number '*' '(' '[' number ']' '&' number ')' {
308 if ($2 != 4 || $9 != 0xf) {
309 fprintf(stderr, "ldxb offset not supported!\n");
312 bpf_set_curr_instr(BPF_LDX | BPF_MSH | BPF_B, 0, 0, $6); } }
316 : OP_ST 'M' '[' number ']' {
317 bpf_set_curr_instr(BPF_ST, 0, 0, $4); }
321 : OP_STX 'M' '[' number ']' {
322 bpf_set_curr_instr(BPF_STX, 0, 0, $4); }
327 bpf_set_jmp_label($2, JKL);
328 bpf_set_curr_instr(BPF_JMP | BPF_JA, 0, 0, 0); }
332 : OP_JEQ '#' number ',' label ',' label {
333 bpf_set_jmp_label($5, JTL);
334 bpf_set_jmp_label($7, JFL);
335 bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_K, 0, 0, $3); }
336 | OP_JEQ 'x' ',' label ',' label {
337 bpf_set_jmp_label($4, JTL);
338 bpf_set_jmp_label($6, JFL);
339 bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_X, 0, 0, 0); }
340 | OP_JEQ '%' 'x' ',' label ',' label {
341 bpf_set_jmp_label($5, JTL);
342 bpf_set_jmp_label($7, JFL);
343 bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_X, 0, 0, 0); }
344 | OP_JEQ '#' number ',' label {
345 bpf_set_jmp_label($5, JTL);
346 bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_K, 0, 0, $3); }
347 | OP_JEQ 'x' ',' label {
348 bpf_set_jmp_label($4, JTL);
349 bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_X, 0, 0, 0); }
350 | OP_JEQ '%' 'x' ',' label {
351 bpf_set_jmp_label($5, JTL);
352 bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_X, 0, 0, 0); }
356 : OP_JNEQ '#' number ',' label {
357 bpf_set_jmp_label($5, JFL);
358 bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_K, 0, 0, $3); }
359 | OP_JNEQ 'x' ',' label {
360 bpf_set_jmp_label($4, JFL);
361 bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_X, 0, 0, 0); }
362 | OP_JNEQ '%' 'x' ',' label {
363 bpf_set_jmp_label($5, JFL);
364 bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_X, 0, 0, 0); }
368 : OP_JLT '#' number ',' label {
369 bpf_set_jmp_label($5, JFL);
370 bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_K, 0, 0, $3); }
371 | OP_JLT 'x' ',' label {
372 bpf_set_jmp_label($4, JFL);
373 bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_X, 0, 0, 0); }
374 | OP_JLT '%' 'x' ',' label {
375 bpf_set_jmp_label($5, JFL);
376 bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_X, 0, 0, 0); }
380 : OP_JLE '#' number ',' label {
381 bpf_set_jmp_label($5, JFL);
382 bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_K, 0, 0, $3); }
383 | OP_JLE 'x' ',' label {
384 bpf_set_jmp_label($4, JFL);
385 bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_X, 0, 0, 0); }
386 | OP_JLE '%' 'x' ',' label {
387 bpf_set_jmp_label($5, JFL);
388 bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_X, 0, 0, 0); }
392 : OP_JGT '#' number ',' label ',' label {
393 bpf_set_jmp_label($5, JTL);
394 bpf_set_jmp_label($7, JFL);
395 bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_K, 0, 0, $3); }
396 | OP_JGT 'x' ',' label ',' label {
397 bpf_set_jmp_label($4, JTL);
398 bpf_set_jmp_label($6, JFL);
399 bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_X, 0, 0, 0); }
400 | OP_JGT '%' 'x' ',' label ',' label {
401 bpf_set_jmp_label($5, JTL);
402 bpf_set_jmp_label($7, JFL);
403 bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_X, 0, 0, 0); }
404 | OP_JGT '#' number ',' label {
405 bpf_set_jmp_label($5, JTL);
406 bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_K, 0, 0, $3); }
407 | OP_JGT 'x' ',' label {
408 bpf_set_jmp_label($4, JTL);
409 bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_X, 0, 0, 0); }
410 | OP_JGT '%' 'x' ',' label {
411 bpf_set_jmp_label($5, JTL);
412 bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_X, 0, 0, 0); }
416 : OP_JGE '#' number ',' label ',' label {
417 bpf_set_jmp_label($5, JTL);
418 bpf_set_jmp_label($7, JFL);
419 bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_K, 0, 0, $3); }
420 | OP_JGE 'x' ',' label ',' label {
421 bpf_set_jmp_label($4, JTL);
422 bpf_set_jmp_label($6, JFL);
423 bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_X, 0, 0, 0); }
424 | OP_JGE '%' 'x' ',' label ',' label {
425 bpf_set_jmp_label($5, JTL);
426 bpf_set_jmp_label($7, JFL);
427 bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_X, 0, 0, 0); }
428 | OP_JGE '#' number ',' label {
429 bpf_set_jmp_label($5, JTL);
430 bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_K, 0, 0, $3); }
431 | OP_JGE 'x' ',' label {
432 bpf_set_jmp_label($4, JTL);
433 bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_X, 0, 0, 0); }
434 | OP_JGE '%' 'x' ',' label {
435 bpf_set_jmp_label($5, JTL);
436 bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_X, 0, 0, 0); }
440 : OP_JSET '#' number ',' label ',' label {
441 bpf_set_jmp_label($5, JTL);
442 bpf_set_jmp_label($7, JFL);
443 bpf_set_curr_instr(BPF_JMP | BPF_JSET | BPF_K, 0, 0, $3); }
444 | OP_JSET 'x' ',' label ',' label {
445 bpf_set_jmp_label($4, JTL);
446 bpf_set_jmp_label($6, JFL);
447 bpf_set_curr_instr(BPF_JMP | BPF_JSET | BPF_X, 0, 0, 0); }
448 | OP_JSET '%' 'x' ',' label ',' label {
449 bpf_set_jmp_label($5, JTL);
450 bpf_set_jmp_label($7, JFL);
451 bpf_set_curr_instr(BPF_JMP | BPF_JSET | BPF_X, 0, 0, 0); }
452 | OP_JSET '#' number ',' label {
453 bpf_set_jmp_label($5, JTL);
454 bpf_set_curr_instr(BPF_JMP | BPF_JSET | BPF_K, 0, 0, $3); }
455 | OP_JSET 'x' ',' label {
456 bpf_set_jmp_label($4, JTL);
457 bpf_set_curr_instr(BPF_JMP | BPF_JSET | BPF_X, 0, 0, 0); }
458 | OP_JSET '%' 'x' ',' label {
459 bpf_set_jmp_label($5, JTL);
460 bpf_set_curr_instr(BPF_JMP | BPF_JSET | BPF_X, 0, 0, 0); }
464 : OP_ADD '#' number {
465 bpf_set_curr_instr(BPF_ALU | BPF_ADD | BPF_K, 0, 0, $3); }
467 bpf_set_curr_instr(BPF_ALU | BPF_ADD | BPF_X, 0, 0, 0); }
469 bpf_set_curr_instr(BPF_ALU | BPF_ADD | BPF_X, 0, 0, 0); }
473 : OP_SUB '#' number {
474 bpf_set_curr_instr(BPF_ALU | BPF_SUB | BPF_K, 0, 0, $3); }
476 bpf_set_curr_instr(BPF_ALU | BPF_SUB | BPF_X, 0, 0, 0); }
478 bpf_set_curr_instr(BPF_ALU | BPF_SUB | BPF_X, 0, 0, 0); }
482 : OP_MUL '#' number {
483 bpf_set_curr_instr(BPF_ALU | BPF_MUL | BPF_K, 0, 0, $3); }
485 bpf_set_curr_instr(BPF_ALU | BPF_MUL | BPF_X, 0, 0, 0); }
487 bpf_set_curr_instr(BPF_ALU | BPF_MUL | BPF_X, 0, 0, 0); }
491 : OP_DIV '#' number {
492 bpf_set_curr_instr(BPF_ALU | BPF_DIV | BPF_K, 0, 0, $3); }
494 bpf_set_curr_instr(BPF_ALU | BPF_DIV | BPF_X, 0, 0, 0); }
496 bpf_set_curr_instr(BPF_ALU | BPF_DIV | BPF_X, 0, 0, 0); }
500 : OP_MOD '#' number {
501 bpf_set_curr_instr(BPF_ALU | BPF_MOD | BPF_K, 0, 0, $3); }
503 bpf_set_curr_instr(BPF_ALU | BPF_MOD | BPF_X, 0, 0, 0); }
505 bpf_set_curr_instr(BPF_ALU | BPF_MOD | BPF_X, 0, 0, 0); }
510 bpf_set_curr_instr(BPF_ALU | BPF_NEG, 0, 0, 0); }
514 : OP_AND '#' number {
515 bpf_set_curr_instr(BPF_ALU | BPF_AND | BPF_K, 0, 0, $3); }
517 bpf_set_curr_instr(BPF_ALU | BPF_AND | BPF_X, 0, 0, 0); }
519 bpf_set_curr_instr(BPF_ALU | BPF_AND | BPF_X, 0, 0, 0); }
524 bpf_set_curr_instr(BPF_ALU | BPF_OR | BPF_K, 0, 0, $3); }
526 bpf_set_curr_instr(BPF_ALU | BPF_OR | BPF_X, 0, 0, 0); }
528 bpf_set_curr_instr(BPF_ALU | BPF_OR | BPF_X, 0, 0, 0); }
532 : OP_XOR '#' number {
533 bpf_set_curr_instr(BPF_ALU | BPF_XOR | BPF_K, 0, 0, $3); }
535 bpf_set_curr_instr(BPF_ALU | BPF_XOR | BPF_X, 0, 0, 0); }
537 bpf_set_curr_instr(BPF_ALU | BPF_XOR | BPF_X, 0, 0, 0); }
541 : OP_LSH '#' number {
542 bpf_set_curr_instr(BPF_ALU | BPF_LSH | BPF_K, 0, 0, $3); }
544 bpf_set_curr_instr(BPF_ALU | BPF_LSH | BPF_X, 0, 0, 0); }
546 bpf_set_curr_instr(BPF_ALU | BPF_LSH | BPF_X, 0, 0, 0); }
550 : OP_RSH '#' number {
551 bpf_set_curr_instr(BPF_ALU | BPF_RSH | BPF_K, 0, 0, $3); }
553 bpf_set_curr_instr(BPF_ALU | BPF_RSH | BPF_X, 0, 0, 0); }
555 bpf_set_curr_instr(BPF_ALU | BPF_RSH | BPF_X, 0, 0, 0); }
560 bpf_set_curr_instr(BPF_RET | BPF_A, 0, 0, 0); }
562 bpf_set_curr_instr(BPF_RET | BPF_A, 0, 0, 0); }
564 bpf_set_curr_instr(BPF_RET | BPF_X, 0, 0, 0); }
566 bpf_set_curr_instr(BPF_RET | BPF_X, 0, 0, 0); }
567 | OP_RET '#' number {
568 bpf_set_curr_instr(BPF_RET | BPF_K, 0, 0, $3); }
573 bpf_set_curr_instr(BPF_MISC | BPF_TAX, 0, 0, 0); }
578 bpf_set_curr_instr(BPF_MISC | BPF_TXA, 0, 0, 0); }
583 static int curr_instr = 0;
584 static struct sock_filter out[BPF_MAXINSNS];
585 static char **labels, **labels_jt, **labels_jf, **labels_k;
587 static void bpf_assert_max(void)
589 if (curr_instr >= BPF_MAXINSNS) {
590 fprintf(stderr, "only max %u insns allowed!\n", BPF_MAXINSNS);
595 static void bpf_set_curr_instr(uint16_t code, uint8_t jt, uint8_t jf,
599 out[curr_instr].code = code;
600 out[curr_instr].jt = jt;
601 out[curr_instr].jf = jf;
602 out[curr_instr].k = k;
606 static void bpf_set_curr_label(char *label)
609 labels[curr_instr] = label;
612 static void bpf_set_jmp_label(char *label, enum jmp_type type)
617 labels_jt[curr_instr] = label;
620 labels_jf[curr_instr] = label;
623 labels_k[curr_instr] = label;
628 static int bpf_find_insns_offset(const char *label)
630 int i, max = curr_instr, ret = -ENOENT;
632 for (i = 0; i < max; i++) {
633 if (labels[i] && !strcmp(label, labels[i])) {
639 if (ret == -ENOENT) {
640 fprintf(stderr, "no such label \'%s\'!\n", label);
647 static void bpf_stage_1_insert_insns(void)
652 static void bpf_reduce_k_jumps(void)
656 for (i = 0; i < curr_instr; i++) {
658 int off = bpf_find_insns_offset(labels_k[i]);
659 out[i].k = (uint32_t) (off - i - 1);
664 static void bpf_reduce_jt_jumps(void)
668 for (i = 0; i < curr_instr; i++) {
670 int off = bpf_find_insns_offset(labels_jt[i]);
671 out[i].jt = (uint8_t) (off - i -1);
676 static void bpf_reduce_jf_jumps(void)
680 for (i = 0; i < curr_instr; i++) {
682 int off = bpf_find_insns_offset(labels_jf[i]);
683 out[i].jf = (uint8_t) (off - i - 1);
688 static void bpf_stage_2_reduce_labels(void)
690 bpf_reduce_k_jumps();
691 bpf_reduce_jt_jumps();
692 bpf_reduce_jf_jumps();
695 static void bpf_pretty_print_c(void)
699 for (i = 0; i < curr_instr; i++)
700 printf("{ %#04x, %2u, %2u, %#010x },\n", out[i].code,
701 out[i].jt, out[i].jf, out[i].k);
704 static void bpf_pretty_print(void)
708 printf("%u,", curr_instr);
709 for (i = 0; i < curr_instr; i++)
710 printf("%u %u %u %u,", out[i].code,
711 out[i].jt, out[i].jf, out[i].k);
715 static void bpf_init(void)
717 memset(out, 0, sizeof(out));
719 labels = calloc(BPF_MAXINSNS, sizeof(*labels));
721 labels_jt = calloc(BPF_MAXINSNS, sizeof(*labels_jt));
723 labels_jf = calloc(BPF_MAXINSNS, sizeof(*labels_jf));
725 labels_k = calloc(BPF_MAXINSNS, sizeof(*labels_k));
729 static void bpf_destroy_labels(void)
733 for (i = 0; i < curr_instr; i++) {
741 static void bpf_destroy(void)
743 bpf_destroy_labels();
750 void bpf_asm_compile(FILE *fp, bool cstyle)
755 bpf_stage_1_insert_insns();
756 bpf_stage_2_reduce_labels();
760 bpf_pretty_print_c();
768 void yyerror(const char *str)