1 /*
2 * Copyright (c) 1990, 1991, 1992, 1994, 1995, 1996
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that: (1) source code distributions
7 * retain the above copyright notice and this paragraph in its entirety, (2)
8 * distributions including binary code include the above copyright notice and
9 * this paragraph in its entirety in the documentation or other materials
10 * provided with the distribution, and (3) all advertising materials mentioning
11 * features or use of this software display the following acknowledgement:
12 * ``This product includes software developed by the University of California,
13 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
14 * the University nor the names of its contributors may be used to endorse
15 * or promote products derived from this software without specific prior
16 * written permission.
17 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
18 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
20 */
21
22 #ifdef HAVE_CONFIG_H
23 #include <config.h>
24 #endif
25
26 #include <pcap-types.h>
27
28 #include <stdio.h>
29 #include <string.h>
30
31 #ifdef __linux__
32 #include <linux/types.h>
33 #include <linux/if_packet.h>
34 #include <linux/filter.h>
35
36 /*
37 * We want our versions of these #defines, not Linux's version.
38 * (The two should be the same; if not, we have a problem; all BPF
39 * implementations *should* be source-compatible supersets of ours.)
40 */
41 #undef BPF_STMT
42 #undef BPF_JUMP
43 #endif
44
45 #include "pcap-int.h"
46
47 #ifdef HAVE_OS_PROTO_H
48 #include "os-proto.h"
49 #endif
50
51 #ifdef SKF_AD_OFF
52 /*
53 * Symbolic names for offsets that refer to the special Linux BPF locations.
54 */
55 static const char *offsets[SKF_AD_MAX] = {
56 #ifdef SKF_AD_PROTOCOL
57 [SKF_AD_PROTOCOL] = "proto",
58 #endif
59 #ifdef SKF_AD_PKTTYPE
60 [SKF_AD_PKTTYPE] = "type",
61 #endif
62 #ifdef SKF_AD_IFINDEX
63 [SKF_AD_IFINDEX] = "ifidx",
64 #endif
65 #ifdef SKF_AD_NLATTR
66 [SKF_AD_NLATTR] = "nla",
67 #endif
68 #ifdef SKF_AD_NLATTR_NEST
69 [SKF_AD_NLATTR_NEST] = "nlan",
70 #endif
71 #ifdef SKF_AD_MARK
72 [SKF_AD_MARK] = "mark",
73 #endif
74 #ifdef SKF_AD_QUEUE
75 [SKF_AD_QUEUE] = "queue",
76 #endif
77 #ifdef SKF_AD_HATYPE
78 [SKF_AD_HATYPE] = "hatype",
79 #endif
80 #ifdef SKF_AD_RXHASH
81 [SKF_AD_RXHASH] = "rxhash",
82 #endif
83 #ifdef SKF_AD_CPU
84 [SKF_AD_CPU] = "cpu",
85 #endif
86 #ifdef SKF_AD_ALU_XOR_X
87 [SKF_AD_ALU_XOR_X] = "xor_x",
88 #endif
89 #ifdef SKF_AD_VLAN_TAG
90 [SKF_AD_VLAN_TAG] = "vlan_tci",
91 #endif
92 #ifdef SKF_AD_VLAN_TAG_PRESENT
93 [SKF_AD_VLAN_TAG_PRESENT] = "vlanp",
94 #endif
95 #ifdef SKF_AD_PAY_OFFSET
96 [SKF_AD_PAY_OFFSET] = "poff",
97 #endif
98 #ifdef SKF_AD_RANDOM
99 [SKF_AD_RANDOM] = "random",
100 #endif
101 #ifdef SKF_AD_VLAN_TPID
102 [SKF_AD_VLAN_TPID] = "vlan_tpid"
103 #endif
104 };
105 #endif
106
107 static void
bpf_print_abs_load_operand(char * buf,size_t bufsize,const struct bpf_insn * p)108 bpf_print_abs_load_operand(char *buf, size_t bufsize, const struct bpf_insn *p)
109 {
110 #ifdef SKF_AD_OFF
111 const char *sym;
112
113 /*
114 * It's an absolute load.
115 * Is the offset a special Linux offset that we know about?
116 */
117 if (p->k >= (bpf_u_int32)SKF_AD_OFF &&
118 p->k < (bpf_u_int32)(SKF_AD_OFF + SKF_AD_MAX) &&
119 (sym = offsets[p->k - (bpf_u_int32)SKF_AD_OFF]) != NULL) {
120 /*
121 * Yes. Print the offset symbolically.
122 */
123 (void)snprintf(buf, bufsize, "[%s]", sym);
124 } else
125 #endif
126 (void)snprintf(buf, bufsize, "[%d]", p->k);
127 }
128
129 char *
bpf_image(const struct bpf_insn * p,int n)130 bpf_image(const struct bpf_insn *p, int n)
131 {
132 const char *op;
133 static char image[256];
134 char operand_buf[64];
135 const char *operand;
136
137 switch (p->code) {
138
139 default:
140 op = "unimp";
141 (void)snprintf(operand_buf, sizeof operand_buf, "0x%x", p->code);
142 operand = operand_buf;
143 break;
144
145 case BPF_RET|BPF_K:
146 op = "ret";
147 (void)snprintf(operand_buf, sizeof operand_buf, "#%d", p->k);
148 operand = operand_buf;
149 break;
150
151 case BPF_RET|BPF_A:
152 op = "ret";
153 operand = "";
154 break;
155
156 case BPF_LD|BPF_W|BPF_ABS:
157 op = "ld";
158 bpf_print_abs_load_operand(operand_buf, sizeof operand_buf, p);
159 operand = operand_buf;
160 break;
161
162 case BPF_LD|BPF_H|BPF_ABS:
163 op = "ldh";
164 bpf_print_abs_load_operand(operand_buf, sizeof operand_buf, p);
165 operand = operand_buf;
166 break;
167
168 case BPF_LD|BPF_B|BPF_ABS:
169 op = "ldb";
170 bpf_print_abs_load_operand(operand_buf, sizeof operand_buf, p);
171 operand = operand_buf;
172 break;
173
174 case BPF_LD|BPF_W|BPF_LEN:
175 op = "ld";
176 operand = "#pktlen";
177 break;
178
179 case BPF_LD|BPF_W|BPF_IND:
180 op = "ld";
181 (void)snprintf(operand_buf, sizeof operand_buf, "[x + %d]", p->k);
182 operand = operand_buf;
183 break;
184
185 case BPF_LD|BPF_H|BPF_IND:
186 op = "ldh";
187 (void)snprintf(operand_buf, sizeof operand_buf, "[x + %d]", p->k);
188 operand = operand_buf;
189 break;
190
191 case BPF_LD|BPF_B|BPF_IND:
192 op = "ldb";
193 (void)snprintf(operand_buf, sizeof operand_buf, "[x + %d]", p->k);
194 operand = operand_buf;
195 break;
196
197 case BPF_LD|BPF_IMM:
198 op = "ld";
199 (void)snprintf(operand_buf, sizeof operand_buf, "#0x%x", p->k);
200 operand = operand_buf;
201 break;
202
203 case BPF_LDX|BPF_IMM:
204 op = "ldx";
205 (void)snprintf(operand_buf, sizeof operand_buf, "#0x%x", p->k);
206 operand = operand_buf;
207 break;
208
209 case BPF_LDX|BPF_MSH|BPF_B:
210 op = "ldxb";
211 (void)snprintf(operand_buf, sizeof operand_buf, "4*([%d]&0xf)", p->k);
212 operand = operand_buf;
213 break;
214
215 case BPF_LD|BPF_MEM:
216 op = "ld";
217 (void)snprintf(operand_buf, sizeof operand_buf, "M[%d]", p->k);
218 operand = operand_buf;
219 break;
220
221 case BPF_LDX|BPF_MEM:
222 op = "ldx";
223 (void)snprintf(operand_buf, sizeof operand_buf, "M[%d]", p->k);
224 operand = operand_buf;
225 break;
226
227 case BPF_ST:
228 op = "st";
229 (void)snprintf(operand_buf, sizeof operand_buf, "M[%d]", p->k);
230 operand = operand_buf;
231 break;
232
233 case BPF_STX:
234 op = "stx";
235 (void)snprintf(operand_buf, sizeof operand_buf, "M[%d]", p->k);
236 operand = operand_buf;
237 break;
238
239 case BPF_JMP|BPF_JA:
240 op = "ja";
241 (void)snprintf(operand_buf, sizeof operand_buf, "%d", n + 1 + p->k);
242 operand = operand_buf;
243 break;
244
245 case BPF_JMP|BPF_JGT|BPF_K:
246 op = "jgt";
247 (void)snprintf(operand_buf, sizeof operand_buf, "#0x%x", p->k);
248 operand = operand_buf;
249 break;
250
251 case BPF_JMP|BPF_JGE|BPF_K:
252 op = "jge";
253 (void)snprintf(operand_buf, sizeof operand_buf, "#0x%x", p->k);
254 operand = operand_buf;
255 break;
256
257 case BPF_JMP|BPF_JEQ|BPF_K:
258 op = "jeq";
259 (void)snprintf(operand_buf, sizeof operand_buf, "#0x%x", p->k);
260 operand = operand_buf;
261 break;
262
263 case BPF_JMP|BPF_JSET|BPF_K:
264 op = "jset";
265 (void)snprintf(operand_buf, sizeof operand_buf, "#0x%x", p->k);
266 operand = operand_buf;
267 break;
268
269 case BPF_JMP|BPF_JGT|BPF_X:
270 op = "jgt";
271 operand = "x";
272 break;
273
274 case BPF_JMP|BPF_JGE|BPF_X:
275 op = "jge";
276 operand = "x";
277 break;
278
279 case BPF_JMP|BPF_JEQ|BPF_X:
280 op = "jeq";
281 operand = "x";
282 break;
283
284 case BPF_JMP|BPF_JSET|BPF_X:
285 op = "jset";
286 operand = "x";
287 break;
288
289 case BPF_ALU|BPF_ADD|BPF_X:
290 op = "add";
291 operand = "x";
292 break;
293
294 case BPF_ALU|BPF_SUB|BPF_X:
295 op = "sub";
296 operand = "x";
297 break;
298
299 case BPF_ALU|BPF_MUL|BPF_X:
300 op = "mul";
301 operand = "x";
302 break;
303
304 case BPF_ALU|BPF_DIV|BPF_X:
305 op = "div";
306 operand = "x";
307 break;
308
309 case BPF_ALU|BPF_MOD|BPF_X:
310 op = "mod";
311 operand = "x";
312 break;
313
314 case BPF_ALU|BPF_AND|BPF_X:
315 op = "and";
316 operand = "x";
317 break;
318
319 case BPF_ALU|BPF_OR|BPF_X:
320 op = "or";
321 operand = "x";
322 break;
323
324 case BPF_ALU|BPF_XOR|BPF_X:
325 op = "xor";
326 operand = "x";
327 break;
328
329 case BPF_ALU|BPF_LSH|BPF_X:
330 op = "lsh";
331 operand = "x";
332 break;
333
334 case BPF_ALU|BPF_RSH|BPF_X:
335 op = "rsh";
336 operand = "x";
337 break;
338
339 case BPF_ALU|BPF_ADD|BPF_K:
340 op = "add";
341 (void)snprintf(operand_buf, sizeof operand_buf, "#%d", p->k);
342 operand = operand_buf;
343 break;
344
345 case BPF_ALU|BPF_SUB|BPF_K:
346 op = "sub";
347 (void)snprintf(operand_buf, sizeof operand_buf, "#%d", p->k);
348 operand = operand_buf;
349 break;
350
351 case BPF_ALU|BPF_MUL|BPF_K:
352 op = "mul";
353 (void)snprintf(operand_buf, sizeof operand_buf, "#%d", p->k);
354 operand = operand_buf;
355 break;
356
357 case BPF_ALU|BPF_DIV|BPF_K:
358 op = "div";
359 (void)snprintf(operand_buf, sizeof operand_buf, "#%d", p->k);
360 operand = operand_buf;
361 break;
362
363 case BPF_ALU|BPF_MOD|BPF_K:
364 op = "mod";
365 (void)snprintf(operand_buf, sizeof operand_buf, "#%d", p->k);
366 operand = operand_buf;
367 break;
368
369 case BPF_ALU|BPF_AND|BPF_K:
370 op = "and";
371 (void)snprintf(operand_buf, sizeof operand_buf, "#0x%x", p->k);
372 operand = operand_buf;
373 break;
374
375 case BPF_ALU|BPF_OR|BPF_K:
376 op = "or";
377 (void)snprintf(operand_buf, sizeof operand_buf, "#0x%x", p->k);
378 operand = operand_buf;
379 break;
380
381 case BPF_ALU|BPF_XOR|BPF_K:
382 op = "xor";
383 (void)snprintf(operand_buf, sizeof operand_buf, "#0x%x", p->k);
384 operand = operand_buf;
385 break;
386
387 case BPF_ALU|BPF_LSH|BPF_K:
388 op = "lsh";
389 (void)snprintf(operand_buf, sizeof operand_buf, "#%d", p->k);
390 operand = operand_buf;
391 break;
392
393 case BPF_ALU|BPF_RSH|BPF_K:
394 op = "rsh";
395 (void)snprintf(operand_buf, sizeof operand_buf, "#%d", p->k);
396 operand = operand_buf;
397 break;
398
399 case BPF_ALU|BPF_NEG:
400 op = "neg";
401 operand = "";
402 break;
403
404 case BPF_MISC|BPF_TAX:
405 op = "tax";
406 operand = "";
407 break;
408
409 case BPF_MISC|BPF_TXA:
410 op = "txa";
411 operand = "";
412 break;
413 }
414 if (BPF_CLASS(p->code) == BPF_JMP && BPF_OP(p->code) != BPF_JA) {
415 (void)snprintf(image, sizeof image,
416 "(%03d) %-8s %-16s jt %d\tjf %d",
417 n, op, operand, n + 1 + p->jt, n + 1 + p->jf);
418 } else {
419 (void)snprintf(image, sizeof image,
420 "(%03d) %-8s %s",
421 n, op, operand);
422 }
423 return image;
424 }
425