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3f356385 DB |
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); | |
43 | static void bpf_set_curr_label(const char *label); | |
44 | static void bpf_set_jmp_label(const char *label, enum jmp_type type); | |
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]; | |
576 | static const char **labels, **labels_jt, **labels_jf, **labels_k; | |
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 | ||
597 | static void bpf_set_curr_label(const char *label) | |
598 | { | |
599 | bpf_assert_max(); | |
600 | labels[curr_instr] = label; | |
601 | } | |
602 | ||
603 | static void bpf_set_jmp_label(const char *label, enum jmp_type type) | |
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 | ||
720 | static void bpf_destroy(void) | |
721 | { | |
722 | free(labels); | |
723 | free(labels_jt); | |
724 | free(labels_jf); | |
725 | free(labels_k); | |
726 | } | |
727 | ||
728 | void bpf_asm_compile(FILE *fp, bool cstyle) | |
729 | { | |
730 | yyin = fp; | |
731 | ||
732 | bpf_init(); | |
733 | bpf_stage_1_insert_insns(); | |
734 | bpf_stage_2_reduce_labels(); | |
735 | bpf_destroy(); | |
736 | ||
737 | if (cstyle) | |
738 | bpf_pretty_print_c(); | |
739 | else | |
740 | bpf_pretty_print(); | |
741 | ||
742 | if (fp != stdin) | |
743 | fclose(yyin); | |
744 | } | |
745 | ||
746 | void yyerror(const char *str) | |
747 | { | |
748 | exit(1); | |
749 | } |