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a7d7a392 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
fd981e3c DB |
2 | /* |
3 | * Minimal BPF debugger | |
4 | * | |
5 | * Minimal BPF debugger that mimics the kernel's engine (w/o extensions) | |
6 | * and allows for single stepping through selected packets from a pcap | |
7 | * with a provided user filter in order to facilitate verification of a | |
8 | * BPF program. Besides others, this is useful to verify BPF programs | |
9 | * before attaching to a live system, and can be used in socket filters, | |
10 | * cls_bpf, xt_bpf, team driver and e.g. PTP code; in particular when a | |
11 | * single more complex BPF program is being used. Reasons for a more | |
12 | * complex BPF program are likely primarily to optimize execution time | |
13 | * for making a verdict when multiple simple BPF programs are combined | |
14 | * into one in order to prevent parsing same headers multiple times. | |
15 | * | |
cb3f0d56 | 16 | * More on how to debug BPF opcodes see Documentation/networking/filter.rst |
fd981e3c DB |
17 | * which is the main document on BPF. Mini howto for getting started: |
18 | * | |
19 | * 1) `./bpf_dbg` to enter the shell (shell cmds denoted with '>'): | |
20 | * 2) > load bpf 6,40 0 0 12,21 0 3 20... (output from `bpf_asm` or | |
21 | * `tcpdump -iem1 -ddd port 22 | tr '\n' ','` to load as filter) | |
22 | * 3) > load pcap foo.pcap | |
23 | * 4) > run <n>/disassemble/dump/quit (self-explanatory) | |
24 | * 5) > breakpoint 2 (sets bp at loaded BPF insns 2, do `run` then; | |
25 | * multiple bps can be set, of course, a call to `breakpoint` | |
26 | * w/o args shows currently loaded bps, `breakpoint reset` for | |
27 | * resetting all breakpoints) | |
28 | * 6) > select 3 (`run` etc will start from the 3rd packet in the pcap) | |
29 | * 7) > step [-<n>, +<n>] (performs single stepping through the BPF) | |
30 | * | |
31 | * Copyright 2013 Daniel Borkmann <borkmann@redhat.com> | |
fd981e3c DB |
32 | */ |
33 | ||
34 | #include <stdio.h> | |
35 | #include <unistd.h> | |
36 | #include <stdlib.h> | |
37 | #include <ctype.h> | |
38 | #include <stdbool.h> | |
39 | #include <stdarg.h> | |
40 | #include <setjmp.h> | |
41 | #include <linux/filter.h> | |
42 | #include <linux/if_packet.h> | |
43 | #include <readline/readline.h> | |
44 | #include <readline/history.h> | |
45 | #include <sys/types.h> | |
46 | #include <sys/socket.h> | |
47 | #include <sys/stat.h> | |
48 | #include <sys/mman.h> | |
49 | #include <fcntl.h> | |
50 | #include <errno.h> | |
51 | #include <signal.h> | |
52 | #include <arpa/inet.h> | |
53 | #include <net/ethernet.h> | |
54 | ||
55 | #define TCPDUMP_MAGIC 0xa1b2c3d4 | |
56 | ||
57 | #define BPF_LDX_B (BPF_LDX | BPF_B) | |
58 | #define BPF_LDX_W (BPF_LDX | BPF_W) | |
59 | #define BPF_JMP_JA (BPF_JMP | BPF_JA) | |
60 | #define BPF_JMP_JEQ (BPF_JMP | BPF_JEQ) | |
61 | #define BPF_JMP_JGT (BPF_JMP | BPF_JGT) | |
62 | #define BPF_JMP_JGE (BPF_JMP | BPF_JGE) | |
63 | #define BPF_JMP_JSET (BPF_JMP | BPF_JSET) | |
64 | #define BPF_ALU_ADD (BPF_ALU | BPF_ADD) | |
65 | #define BPF_ALU_SUB (BPF_ALU | BPF_SUB) | |
66 | #define BPF_ALU_MUL (BPF_ALU | BPF_MUL) | |
67 | #define BPF_ALU_DIV (BPF_ALU | BPF_DIV) | |
68 | #define BPF_ALU_MOD (BPF_ALU | BPF_MOD) | |
69 | #define BPF_ALU_NEG (BPF_ALU | BPF_NEG) | |
70 | #define BPF_ALU_AND (BPF_ALU | BPF_AND) | |
71 | #define BPF_ALU_OR (BPF_ALU | BPF_OR) | |
72 | #define BPF_ALU_XOR (BPF_ALU | BPF_XOR) | |
73 | #define BPF_ALU_LSH (BPF_ALU | BPF_LSH) | |
74 | #define BPF_ALU_RSH (BPF_ALU | BPF_RSH) | |
75 | #define BPF_MISC_TAX (BPF_MISC | BPF_TAX) | |
76 | #define BPF_MISC_TXA (BPF_MISC | BPF_TXA) | |
77 | #define BPF_LD_B (BPF_LD | BPF_B) | |
78 | #define BPF_LD_H (BPF_LD | BPF_H) | |
79 | #define BPF_LD_W (BPF_LD | BPF_W) | |
80 | ||
81 | #ifndef array_size | |
82 | # define array_size(x) (sizeof(x) / sizeof((x)[0])) | |
83 | #endif | |
84 | ||
85 | #ifndef __check_format_printf | |
86 | # define __check_format_printf(pos_fmtstr, pos_fmtargs) \ | |
87 | __attribute__ ((format (printf, (pos_fmtstr), (pos_fmtargs)))) | |
88 | #endif | |
89 | ||
fd981e3c DB |
90 | enum { |
91 | CMD_OK, | |
92 | CMD_ERR, | |
93 | CMD_EX, | |
94 | }; | |
95 | ||
96 | struct shell_cmd { | |
97 | const char *name; | |
98 | int (*func)(char *args); | |
99 | }; | |
100 | ||
101 | struct pcap_filehdr { | |
102 | uint32_t magic; | |
103 | uint16_t version_major; | |
104 | uint16_t version_minor; | |
105 | int32_t thiszone; | |
106 | uint32_t sigfigs; | |
107 | uint32_t snaplen; | |
108 | uint32_t linktype; | |
109 | }; | |
110 | ||
111 | struct pcap_timeval { | |
112 | int32_t tv_sec; | |
113 | int32_t tv_usec; | |
114 | }; | |
115 | ||
116 | struct pcap_pkthdr { | |
117 | struct pcap_timeval ts; | |
118 | uint32_t caplen; | |
119 | uint32_t len; | |
120 | }; | |
121 | ||
122 | struct bpf_regs { | |
123 | uint32_t A; | |
124 | uint32_t X; | |
125 | uint32_t M[BPF_MEMWORDS]; | |
126 | uint32_t R; | |
127 | bool Rs; | |
128 | uint16_t Pc; | |
129 | }; | |
130 | ||
131 | static struct sock_filter bpf_image[BPF_MAXINSNS + 1]; | |
1490d2bd | 132 | static unsigned int bpf_prog_len; |
fd981e3c DB |
133 | |
134 | static int bpf_breakpoints[64]; | |
135 | static struct bpf_regs bpf_regs[BPF_MAXINSNS + 1]; | |
136 | static struct bpf_regs bpf_curr; | |
1490d2bd | 137 | static unsigned int bpf_regs_len; |
fd981e3c DB |
138 | |
139 | static int pcap_fd = -1; | |
1490d2bd WT |
140 | static unsigned int pcap_packet; |
141 | static size_t pcap_map_size; | |
fd981e3c DB |
142 | static char *pcap_ptr_va_start, *pcap_ptr_va_curr; |
143 | ||
144 | static const char * const op_table[] = { | |
7debf780 DB |
145 | [BPF_ST] = "st", |
146 | [BPF_STX] = "stx", | |
147 | [BPF_LD_B] = "ldb", | |
148 | [BPF_LD_H] = "ldh", | |
149 | [BPF_LD_W] = "ld", | |
150 | [BPF_LDX] = "ldx", | |
151 | [BPF_LDX_B] = "ldxb", | |
152 | [BPF_JMP_JA] = "ja", | |
153 | [BPF_JMP_JEQ] = "jeq", | |
154 | [BPF_JMP_JGT] = "jgt", | |
155 | [BPF_JMP_JGE] = "jge", | |
156 | [BPF_JMP_JSET] = "jset", | |
157 | [BPF_ALU_ADD] = "add", | |
158 | [BPF_ALU_SUB] = "sub", | |
159 | [BPF_ALU_MUL] = "mul", | |
160 | [BPF_ALU_DIV] = "div", | |
161 | [BPF_ALU_MOD] = "mod", | |
162 | [BPF_ALU_NEG] = "neg", | |
163 | [BPF_ALU_AND] = "and", | |
164 | [BPF_ALU_OR] = "or", | |
165 | [BPF_ALU_XOR] = "xor", | |
166 | [BPF_ALU_LSH] = "lsh", | |
167 | [BPF_ALU_RSH] = "rsh", | |
168 | [BPF_MISC_TAX] = "tax", | |
169 | [BPF_MISC_TXA] = "txa", | |
170 | [BPF_RET] = "ret", | |
fd981e3c DB |
171 | }; |
172 | ||
173 | static __check_format_printf(1, 2) int rl_printf(const char *fmt, ...) | |
174 | { | |
175 | int ret; | |
176 | va_list vl; | |
177 | ||
178 | va_start(vl, fmt); | |
179 | ret = vfprintf(rl_outstream, fmt, vl); | |
180 | va_end(vl); | |
181 | ||
182 | return ret; | |
183 | } | |
184 | ||
185 | static int matches(const char *cmd, const char *pattern) | |
186 | { | |
187 | int len = strlen(cmd); | |
188 | ||
189 | if (len > strlen(pattern)) | |
190 | return -1; | |
191 | ||
192 | return memcmp(pattern, cmd, len); | |
193 | } | |
194 | ||
195 | static void hex_dump(const uint8_t *buf, size_t len) | |
196 | { | |
197 | int i; | |
198 | ||
199 | rl_printf("%3u: ", 0); | |
200 | for (i = 0; i < len; i++) { | |
201 | if (i && !(i % 16)) | |
202 | rl_printf("\n%3u: ", i); | |
203 | rl_printf("%02x ", buf[i]); | |
204 | } | |
205 | rl_printf("\n"); | |
206 | } | |
207 | ||
208 | static bool bpf_prog_loaded(void) | |
209 | { | |
210 | if (bpf_prog_len == 0) | |
211 | rl_printf("no bpf program loaded!\n"); | |
212 | ||
213 | return bpf_prog_len > 0; | |
214 | } | |
215 | ||
216 | static void bpf_disasm(const struct sock_filter f, unsigned int i) | |
217 | { | |
218 | const char *op, *fmt; | |
219 | int val = f.k; | |
220 | char buf[256]; | |
221 | ||
222 | switch (f.code) { | |
223 | case BPF_RET | BPF_K: | |
224 | op = op_table[BPF_RET]; | |
225 | fmt = "#%#x"; | |
226 | break; | |
227 | case BPF_RET | BPF_A: | |
228 | op = op_table[BPF_RET]; | |
229 | fmt = "a"; | |
230 | break; | |
231 | case BPF_RET | BPF_X: | |
232 | op = op_table[BPF_RET]; | |
233 | fmt = "x"; | |
234 | break; | |
235 | case BPF_MISC_TAX: | |
236 | op = op_table[BPF_MISC_TAX]; | |
237 | fmt = ""; | |
238 | break; | |
239 | case BPF_MISC_TXA: | |
240 | op = op_table[BPF_MISC_TXA]; | |
241 | fmt = ""; | |
242 | break; | |
243 | case BPF_ST: | |
244 | op = op_table[BPF_ST]; | |
245 | fmt = "M[%d]"; | |
246 | break; | |
247 | case BPF_STX: | |
248 | op = op_table[BPF_STX]; | |
249 | fmt = "M[%d]"; | |
250 | break; | |
251 | case BPF_LD_W | BPF_ABS: | |
252 | op = op_table[BPF_LD_W]; | |
253 | fmt = "[%d]"; | |
254 | break; | |
255 | case BPF_LD_H | BPF_ABS: | |
256 | op = op_table[BPF_LD_H]; | |
257 | fmt = "[%d]"; | |
258 | break; | |
259 | case BPF_LD_B | BPF_ABS: | |
260 | op = op_table[BPF_LD_B]; | |
261 | fmt = "[%d]"; | |
262 | break; | |
263 | case BPF_LD_W | BPF_LEN: | |
264 | op = op_table[BPF_LD_W]; | |
265 | fmt = "#len"; | |
266 | break; | |
267 | case BPF_LD_W | BPF_IND: | |
268 | op = op_table[BPF_LD_W]; | |
269 | fmt = "[x+%d]"; | |
270 | break; | |
271 | case BPF_LD_H | BPF_IND: | |
272 | op = op_table[BPF_LD_H]; | |
273 | fmt = "[x+%d]"; | |
274 | break; | |
275 | case BPF_LD_B | BPF_IND: | |
276 | op = op_table[BPF_LD_B]; | |
277 | fmt = "[x+%d]"; | |
278 | break; | |
279 | case BPF_LD | BPF_IMM: | |
280 | op = op_table[BPF_LD_W]; | |
281 | fmt = "#%#x"; | |
282 | break; | |
283 | case BPF_LDX | BPF_IMM: | |
284 | op = op_table[BPF_LDX]; | |
285 | fmt = "#%#x"; | |
286 | break; | |
287 | case BPF_LDX_B | BPF_MSH: | |
288 | op = op_table[BPF_LDX_B]; | |
289 | fmt = "4*([%d]&0xf)"; | |
290 | break; | |
291 | case BPF_LD | BPF_MEM: | |
292 | op = op_table[BPF_LD_W]; | |
293 | fmt = "M[%d]"; | |
294 | break; | |
295 | case BPF_LDX | BPF_MEM: | |
296 | op = op_table[BPF_LDX]; | |
297 | fmt = "M[%d]"; | |
298 | break; | |
299 | case BPF_JMP_JA: | |
300 | op = op_table[BPF_JMP_JA]; | |
301 | fmt = "%d"; | |
302 | val = i + 1 + f.k; | |
303 | break; | |
304 | case BPF_JMP_JGT | BPF_X: | |
305 | op = op_table[BPF_JMP_JGT]; | |
306 | fmt = "x"; | |
307 | break; | |
308 | case BPF_JMP_JGT | BPF_K: | |
309 | op = op_table[BPF_JMP_JGT]; | |
310 | fmt = "#%#x"; | |
311 | break; | |
312 | case BPF_JMP_JGE | BPF_X: | |
313 | op = op_table[BPF_JMP_JGE]; | |
314 | fmt = "x"; | |
315 | break; | |
316 | case BPF_JMP_JGE | BPF_K: | |
317 | op = op_table[BPF_JMP_JGE]; | |
318 | fmt = "#%#x"; | |
319 | break; | |
320 | case BPF_JMP_JEQ | BPF_X: | |
321 | op = op_table[BPF_JMP_JEQ]; | |
322 | fmt = "x"; | |
323 | break; | |
324 | case BPF_JMP_JEQ | BPF_K: | |
325 | op = op_table[BPF_JMP_JEQ]; | |
326 | fmt = "#%#x"; | |
327 | break; | |
328 | case BPF_JMP_JSET | BPF_X: | |
329 | op = op_table[BPF_JMP_JSET]; | |
330 | fmt = "x"; | |
331 | break; | |
332 | case BPF_JMP_JSET | BPF_K: | |
333 | op = op_table[BPF_JMP_JSET]; | |
334 | fmt = "#%#x"; | |
335 | break; | |
336 | case BPF_ALU_NEG: | |
337 | op = op_table[BPF_ALU_NEG]; | |
338 | fmt = ""; | |
339 | break; | |
340 | case BPF_ALU_LSH | BPF_X: | |
341 | op = op_table[BPF_ALU_LSH]; | |
342 | fmt = "x"; | |
343 | break; | |
344 | case BPF_ALU_LSH | BPF_K: | |
345 | op = op_table[BPF_ALU_LSH]; | |
346 | fmt = "#%d"; | |
347 | break; | |
348 | case BPF_ALU_RSH | BPF_X: | |
349 | op = op_table[BPF_ALU_RSH]; | |
350 | fmt = "x"; | |
351 | break; | |
352 | case BPF_ALU_RSH | BPF_K: | |
353 | op = op_table[BPF_ALU_RSH]; | |
354 | fmt = "#%d"; | |
355 | break; | |
356 | case BPF_ALU_ADD | BPF_X: | |
357 | op = op_table[BPF_ALU_ADD]; | |
358 | fmt = "x"; | |
359 | break; | |
360 | case BPF_ALU_ADD | BPF_K: | |
361 | op = op_table[BPF_ALU_ADD]; | |
362 | fmt = "#%d"; | |
363 | break; | |
364 | case BPF_ALU_SUB | BPF_X: | |
365 | op = op_table[BPF_ALU_SUB]; | |
366 | fmt = "x"; | |
367 | break; | |
368 | case BPF_ALU_SUB | BPF_K: | |
369 | op = op_table[BPF_ALU_SUB]; | |
370 | fmt = "#%d"; | |
371 | break; | |
372 | case BPF_ALU_MUL | BPF_X: | |
373 | op = op_table[BPF_ALU_MUL]; | |
374 | fmt = "x"; | |
375 | break; | |
376 | case BPF_ALU_MUL | BPF_K: | |
377 | op = op_table[BPF_ALU_MUL]; | |
378 | fmt = "#%d"; | |
379 | break; | |
380 | case BPF_ALU_DIV | BPF_X: | |
381 | op = op_table[BPF_ALU_DIV]; | |
382 | fmt = "x"; | |
383 | break; | |
384 | case BPF_ALU_DIV | BPF_K: | |
385 | op = op_table[BPF_ALU_DIV]; | |
386 | fmt = "#%d"; | |
387 | break; | |
388 | case BPF_ALU_MOD | BPF_X: | |
389 | op = op_table[BPF_ALU_MOD]; | |
390 | fmt = "x"; | |
391 | break; | |
392 | case BPF_ALU_MOD | BPF_K: | |
393 | op = op_table[BPF_ALU_MOD]; | |
394 | fmt = "#%d"; | |
395 | break; | |
396 | case BPF_ALU_AND | BPF_X: | |
397 | op = op_table[BPF_ALU_AND]; | |
398 | fmt = "x"; | |
399 | break; | |
400 | case BPF_ALU_AND | BPF_K: | |
401 | op = op_table[BPF_ALU_AND]; | |
402 | fmt = "#%#x"; | |
403 | break; | |
404 | case BPF_ALU_OR | BPF_X: | |
405 | op = op_table[BPF_ALU_OR]; | |
406 | fmt = "x"; | |
407 | break; | |
408 | case BPF_ALU_OR | BPF_K: | |
409 | op = op_table[BPF_ALU_OR]; | |
410 | fmt = "#%#x"; | |
411 | break; | |
412 | case BPF_ALU_XOR | BPF_X: | |
413 | op = op_table[BPF_ALU_XOR]; | |
414 | fmt = "x"; | |
415 | break; | |
416 | case BPF_ALU_XOR | BPF_K: | |
417 | op = op_table[BPF_ALU_XOR]; | |
418 | fmt = "#%#x"; | |
419 | break; | |
420 | default: | |
421 | op = "nosup"; | |
422 | fmt = "%#x"; | |
423 | val = f.code; | |
424 | break; | |
425 | } | |
426 | ||
427 | memset(buf, 0, sizeof(buf)); | |
428 | snprintf(buf, sizeof(buf), fmt, val); | |
429 | buf[sizeof(buf) - 1] = 0; | |
430 | ||
431 | if ((BPF_CLASS(f.code) == BPF_JMP && BPF_OP(f.code) != BPF_JA)) | |
432 | rl_printf("l%d:\t%s %s, l%d, l%d\n", i, op, buf, | |
433 | i + 1 + f.jt, i + 1 + f.jf); | |
434 | else | |
435 | rl_printf("l%d:\t%s %s\n", i, op, buf); | |
436 | } | |
437 | ||
438 | static void bpf_dump_curr(struct bpf_regs *r, struct sock_filter *f) | |
439 | { | |
440 | int i, m = 0; | |
441 | ||
442 | rl_printf("pc: [%u]\n", r->Pc); | |
443 | rl_printf("code: [%u] jt[%u] jf[%u] k[%u]\n", | |
444 | f->code, f->jt, f->jf, f->k); | |
445 | rl_printf("curr: "); | |
446 | bpf_disasm(*f, r->Pc); | |
447 | ||
448 | if (f->jt || f->jf) { | |
449 | rl_printf("jt: "); | |
450 | bpf_disasm(*(f + f->jt + 1), r->Pc + f->jt + 1); | |
451 | rl_printf("jf: "); | |
452 | bpf_disasm(*(f + f->jf + 1), r->Pc + f->jf + 1); | |
453 | } | |
454 | ||
455 | rl_printf("A: [%#08x][%u]\n", r->A, r->A); | |
456 | rl_printf("X: [%#08x][%u]\n", r->X, r->X); | |
457 | if (r->Rs) | |
458 | rl_printf("ret: [%#08x][%u]!\n", r->R, r->R); | |
459 | ||
460 | for (i = 0; i < BPF_MEMWORDS; i++) { | |
461 | if (r->M[i]) { | |
462 | m++; | |
463 | rl_printf("M[%d]: [%#08x][%u]\n", i, r->M[i], r->M[i]); | |
464 | } | |
465 | } | |
466 | if (m == 0) | |
467 | rl_printf("M[0,%d]: [%#08x][%u]\n", BPF_MEMWORDS - 1, 0, 0); | |
468 | } | |
469 | ||
470 | static void bpf_dump_pkt(uint8_t *pkt, uint32_t pkt_caplen, uint32_t pkt_len) | |
471 | { | |
472 | if (pkt_caplen != pkt_len) | |
473 | rl_printf("cap: %u, len: %u\n", pkt_caplen, pkt_len); | |
474 | else | |
475 | rl_printf("len: %u\n", pkt_len); | |
476 | ||
477 | hex_dump(pkt, pkt_caplen); | |
478 | } | |
479 | ||
480 | static void bpf_disasm_all(const struct sock_filter *f, unsigned int len) | |
481 | { | |
482 | unsigned int i; | |
483 | ||
484 | for (i = 0; i < len; i++) | |
485 | bpf_disasm(f[i], i); | |
486 | } | |
487 | ||
488 | static void bpf_dump_all(const struct sock_filter *f, unsigned int len) | |
489 | { | |
490 | unsigned int i; | |
491 | ||
492 | rl_printf("/* { op, jt, jf, k }, */\n"); | |
493 | for (i = 0; i < len; i++) | |
494 | rl_printf("{ %#04x, %2u, %2u, %#010x },\n", | |
495 | f[i].code, f[i].jt, f[i].jf, f[i].k); | |
496 | } | |
497 | ||
498 | static bool bpf_runnable(struct sock_filter *f, unsigned int len) | |
499 | { | |
500 | int sock, ret, i; | |
501 | struct sock_fprog bpf = { | |
502 | .filter = f, | |
503 | .len = len, | |
504 | }; | |
505 | ||
506 | sock = socket(AF_INET, SOCK_DGRAM, 0); | |
507 | if (sock < 0) { | |
508 | rl_printf("cannot open socket!\n"); | |
509 | return false; | |
510 | } | |
511 | ret = setsockopt(sock, SOL_SOCKET, SO_ATTACH_FILTER, &bpf, sizeof(bpf)); | |
8b138da6 | 512 | close(sock); |
fd981e3c DB |
513 | if (ret < 0) { |
514 | rl_printf("program not allowed to run by kernel!\n"); | |
515 | return false; | |
516 | } | |
fd981e3c DB |
517 | for (i = 0; i < len; i++) { |
518 | if (BPF_CLASS(f[i].code) == BPF_LD && | |
519 | f[i].k > SKF_AD_OFF) { | |
520 | rl_printf("extensions currently not supported!\n"); | |
521 | return false; | |
522 | } | |
523 | } | |
524 | ||
525 | return true; | |
526 | } | |
527 | ||
528 | static void bpf_reset_breakpoints(void) | |
529 | { | |
530 | int i; | |
531 | ||
532 | for (i = 0; i < array_size(bpf_breakpoints); i++) | |
533 | bpf_breakpoints[i] = -1; | |
534 | } | |
535 | ||
536 | static void bpf_set_breakpoints(unsigned int where) | |
537 | { | |
538 | int i; | |
539 | bool set = false; | |
540 | ||
541 | for (i = 0; i < array_size(bpf_breakpoints); i++) { | |
542 | if (bpf_breakpoints[i] == (int) where) { | |
543 | rl_printf("breakpoint already set!\n"); | |
544 | set = true; | |
545 | break; | |
546 | } | |
547 | ||
548 | if (bpf_breakpoints[i] == -1 && set == false) { | |
549 | bpf_breakpoints[i] = where; | |
550 | set = true; | |
551 | } | |
552 | } | |
553 | ||
554 | if (!set) | |
555 | rl_printf("too many breakpoints set, reset first!\n"); | |
556 | } | |
557 | ||
558 | static void bpf_dump_breakpoints(void) | |
559 | { | |
560 | int i; | |
561 | ||
562 | rl_printf("breakpoints: "); | |
563 | ||
564 | for (i = 0; i < array_size(bpf_breakpoints); i++) { | |
565 | if (bpf_breakpoints[i] < 0) | |
566 | continue; | |
567 | rl_printf("%d ", bpf_breakpoints[i]); | |
568 | } | |
569 | ||
570 | rl_printf("\n"); | |
571 | } | |
572 | ||
573 | static void bpf_reset(void) | |
574 | { | |
575 | bpf_regs_len = 0; | |
576 | ||
577 | memset(bpf_regs, 0, sizeof(bpf_regs)); | |
578 | memset(&bpf_curr, 0, sizeof(bpf_curr)); | |
579 | } | |
580 | ||
581 | static void bpf_safe_regs(void) | |
582 | { | |
583 | memcpy(&bpf_regs[bpf_regs_len++], &bpf_curr, sizeof(bpf_curr)); | |
584 | } | |
585 | ||
586 | static bool bpf_restore_regs(int off) | |
587 | { | |
588 | unsigned int index = bpf_regs_len - 1 + off; | |
589 | ||
590 | if (index == 0) { | |
591 | bpf_reset(); | |
592 | return true; | |
593 | } else if (index < bpf_regs_len) { | |
594 | memcpy(&bpf_curr, &bpf_regs[index], sizeof(bpf_curr)); | |
595 | bpf_regs_len = index; | |
596 | return true; | |
597 | } else { | |
598 | rl_printf("reached bottom of register history stack!\n"); | |
599 | return false; | |
600 | } | |
601 | } | |
602 | ||
603 | static uint32_t extract_u32(uint8_t *pkt, uint32_t off) | |
604 | { | |
605 | uint32_t r; | |
606 | ||
607 | memcpy(&r, &pkt[off], sizeof(r)); | |
608 | ||
609 | return ntohl(r); | |
610 | } | |
611 | ||
612 | static uint16_t extract_u16(uint8_t *pkt, uint32_t off) | |
613 | { | |
614 | uint16_t r; | |
615 | ||
616 | memcpy(&r, &pkt[off], sizeof(r)); | |
617 | ||
618 | return ntohs(r); | |
619 | } | |
620 | ||
621 | static uint8_t extract_u8(uint8_t *pkt, uint32_t off) | |
622 | { | |
623 | return pkt[off]; | |
624 | } | |
625 | ||
626 | static void set_return(struct bpf_regs *r) | |
627 | { | |
628 | r->R = 0; | |
629 | r->Rs = true; | |
630 | } | |
631 | ||
632 | static void bpf_single_step(struct bpf_regs *r, struct sock_filter *f, | |
633 | uint8_t *pkt, uint32_t pkt_caplen, | |
634 | uint32_t pkt_len) | |
635 | { | |
636 | uint32_t K = f->k; | |
637 | int d; | |
638 | ||
639 | switch (f->code) { | |
640 | case BPF_RET | BPF_K: | |
641 | r->R = K; | |
642 | r->Rs = true; | |
643 | break; | |
644 | case BPF_RET | BPF_A: | |
645 | r->R = r->A; | |
646 | r->Rs = true; | |
647 | break; | |
648 | case BPF_RET | BPF_X: | |
649 | r->R = r->X; | |
650 | r->Rs = true; | |
651 | break; | |
652 | case BPF_MISC_TAX: | |
653 | r->X = r->A; | |
654 | break; | |
655 | case BPF_MISC_TXA: | |
656 | r->A = r->X; | |
657 | break; | |
658 | case BPF_ST: | |
659 | r->M[K] = r->A; | |
660 | break; | |
661 | case BPF_STX: | |
662 | r->M[K] = r->X; | |
663 | break; | |
664 | case BPF_LD_W | BPF_ABS: | |
665 | d = pkt_caplen - K; | |
666 | if (d >= sizeof(uint32_t)) | |
667 | r->A = extract_u32(pkt, K); | |
668 | else | |
669 | set_return(r); | |
670 | break; | |
671 | case BPF_LD_H | BPF_ABS: | |
672 | d = pkt_caplen - K; | |
673 | if (d >= sizeof(uint16_t)) | |
674 | r->A = extract_u16(pkt, K); | |
675 | else | |
676 | set_return(r); | |
677 | break; | |
678 | case BPF_LD_B | BPF_ABS: | |
679 | d = pkt_caplen - K; | |
680 | if (d >= sizeof(uint8_t)) | |
681 | r->A = extract_u8(pkt, K); | |
682 | else | |
683 | set_return(r); | |
684 | break; | |
685 | case BPF_LD_W | BPF_IND: | |
686 | d = pkt_caplen - (r->X + K); | |
687 | if (d >= sizeof(uint32_t)) | |
688 | r->A = extract_u32(pkt, r->X + K); | |
689 | break; | |
690 | case BPF_LD_H | BPF_IND: | |
691 | d = pkt_caplen - (r->X + K); | |
692 | if (d >= sizeof(uint16_t)) | |
693 | r->A = extract_u16(pkt, r->X + K); | |
694 | else | |
695 | set_return(r); | |
696 | break; | |
697 | case BPF_LD_B | BPF_IND: | |
698 | d = pkt_caplen - (r->X + K); | |
699 | if (d >= sizeof(uint8_t)) | |
700 | r->A = extract_u8(pkt, r->X + K); | |
701 | else | |
702 | set_return(r); | |
703 | break; | |
704 | case BPF_LDX_B | BPF_MSH: | |
705 | d = pkt_caplen - K; | |
706 | if (d >= sizeof(uint8_t)) { | |
707 | r->X = extract_u8(pkt, K); | |
708 | r->X = (r->X & 0xf) << 2; | |
709 | } else | |
710 | set_return(r); | |
711 | break; | |
712 | case BPF_LD_W | BPF_LEN: | |
713 | r->A = pkt_len; | |
714 | break; | |
715 | case BPF_LDX_W | BPF_LEN: | |
716 | r->A = pkt_len; | |
717 | break; | |
718 | case BPF_LD | BPF_IMM: | |
719 | r->A = K; | |
720 | break; | |
721 | case BPF_LDX | BPF_IMM: | |
722 | r->X = K; | |
723 | break; | |
724 | case BPF_LD | BPF_MEM: | |
725 | r->A = r->M[K]; | |
726 | break; | |
727 | case BPF_LDX | BPF_MEM: | |
728 | r->X = r->M[K]; | |
729 | break; | |
730 | case BPF_JMP_JA: | |
731 | r->Pc += K; | |
732 | break; | |
733 | case BPF_JMP_JGT | BPF_X: | |
734 | r->Pc += r->A > r->X ? f->jt : f->jf; | |
735 | break; | |
736 | case BPF_JMP_JGT | BPF_K: | |
737 | r->Pc += r->A > K ? f->jt : f->jf; | |
738 | break; | |
739 | case BPF_JMP_JGE | BPF_X: | |
740 | r->Pc += r->A >= r->X ? f->jt : f->jf; | |
741 | break; | |
742 | case BPF_JMP_JGE | BPF_K: | |
743 | r->Pc += r->A >= K ? f->jt : f->jf; | |
744 | break; | |
745 | case BPF_JMP_JEQ | BPF_X: | |
746 | r->Pc += r->A == r->X ? f->jt : f->jf; | |
747 | break; | |
748 | case BPF_JMP_JEQ | BPF_K: | |
749 | r->Pc += r->A == K ? f->jt : f->jf; | |
750 | break; | |
751 | case BPF_JMP_JSET | BPF_X: | |
752 | r->Pc += r->A & r->X ? f->jt : f->jf; | |
753 | break; | |
754 | case BPF_JMP_JSET | BPF_K: | |
755 | r->Pc += r->A & K ? f->jt : f->jf; | |
756 | break; | |
757 | case BPF_ALU_NEG: | |
758 | r->A = -r->A; | |
759 | break; | |
760 | case BPF_ALU_LSH | BPF_X: | |
761 | r->A <<= r->X; | |
762 | break; | |
763 | case BPF_ALU_LSH | BPF_K: | |
764 | r->A <<= K; | |
765 | break; | |
766 | case BPF_ALU_RSH | BPF_X: | |
767 | r->A >>= r->X; | |
768 | break; | |
769 | case BPF_ALU_RSH | BPF_K: | |
770 | r->A >>= K; | |
771 | break; | |
772 | case BPF_ALU_ADD | BPF_X: | |
773 | r->A += r->X; | |
774 | break; | |
775 | case BPF_ALU_ADD | BPF_K: | |
776 | r->A += K; | |
777 | break; | |
778 | case BPF_ALU_SUB | BPF_X: | |
779 | r->A -= r->X; | |
780 | break; | |
781 | case BPF_ALU_SUB | BPF_K: | |
782 | r->A -= K; | |
783 | break; | |
784 | case BPF_ALU_MUL | BPF_X: | |
785 | r->A *= r->X; | |
786 | break; | |
787 | case BPF_ALU_MUL | BPF_K: | |
788 | r->A *= K; | |
789 | break; | |
790 | case BPF_ALU_DIV | BPF_X: | |
791 | case BPF_ALU_MOD | BPF_X: | |
792 | if (r->X == 0) { | |
793 | set_return(r); | |
794 | break; | |
795 | } | |
796 | goto do_div; | |
797 | case BPF_ALU_DIV | BPF_K: | |
798 | case BPF_ALU_MOD | BPF_K: | |
799 | if (K == 0) { | |
800 | set_return(r); | |
801 | break; | |
802 | } | |
803 | do_div: | |
804 | switch (f->code) { | |
805 | case BPF_ALU_DIV | BPF_X: | |
806 | r->A /= r->X; | |
807 | break; | |
808 | case BPF_ALU_DIV | BPF_K: | |
809 | r->A /= K; | |
810 | break; | |
811 | case BPF_ALU_MOD | BPF_X: | |
812 | r->A %= r->X; | |
813 | break; | |
814 | case BPF_ALU_MOD | BPF_K: | |
815 | r->A %= K; | |
816 | break; | |
817 | } | |
818 | break; | |
819 | case BPF_ALU_AND | BPF_X: | |
820 | r->A &= r->X; | |
821 | break; | |
822 | case BPF_ALU_AND | BPF_K: | |
e5744fe9 | 823 | r->A &= K; |
fd981e3c DB |
824 | break; |
825 | case BPF_ALU_OR | BPF_X: | |
826 | r->A |= r->X; | |
827 | break; | |
828 | case BPF_ALU_OR | BPF_K: | |
829 | r->A |= K; | |
830 | break; | |
831 | case BPF_ALU_XOR | BPF_X: | |
832 | r->A ^= r->X; | |
833 | break; | |
834 | case BPF_ALU_XOR | BPF_K: | |
835 | r->A ^= K; | |
836 | break; | |
837 | } | |
838 | } | |
839 | ||
840 | static bool bpf_pc_has_breakpoint(uint16_t pc) | |
841 | { | |
842 | int i; | |
843 | ||
844 | for (i = 0; i < array_size(bpf_breakpoints); i++) { | |
845 | if (bpf_breakpoints[i] < 0) | |
846 | continue; | |
847 | if (bpf_breakpoints[i] == pc) | |
848 | return true; | |
849 | } | |
850 | ||
851 | return false; | |
852 | } | |
853 | ||
854 | static bool bpf_handle_breakpoint(struct bpf_regs *r, struct sock_filter *f, | |
855 | uint8_t *pkt, uint32_t pkt_caplen, | |
856 | uint32_t pkt_len) | |
857 | { | |
858 | rl_printf("-- register dump --\n"); | |
859 | bpf_dump_curr(r, &f[r->Pc]); | |
860 | rl_printf("-- packet dump --\n"); | |
861 | bpf_dump_pkt(pkt, pkt_caplen, pkt_len); | |
862 | rl_printf("(breakpoint)\n"); | |
863 | return true; | |
864 | } | |
865 | ||
866 | static int bpf_run_all(struct sock_filter *f, uint16_t bpf_len, uint8_t *pkt, | |
867 | uint32_t pkt_caplen, uint32_t pkt_len) | |
868 | { | |
869 | bool stop = false; | |
870 | ||
871 | while (bpf_curr.Rs == false && stop == false) { | |
872 | bpf_safe_regs(); | |
873 | ||
874 | if (bpf_pc_has_breakpoint(bpf_curr.Pc)) | |
875 | stop = bpf_handle_breakpoint(&bpf_curr, f, pkt, | |
876 | pkt_caplen, pkt_len); | |
877 | ||
878 | bpf_single_step(&bpf_curr, &f[bpf_curr.Pc], pkt, pkt_caplen, | |
879 | pkt_len); | |
880 | bpf_curr.Pc++; | |
881 | } | |
882 | ||
883 | return stop ? -1 : bpf_curr.R; | |
884 | } | |
885 | ||
886 | static int bpf_run_stepping(struct sock_filter *f, uint16_t bpf_len, | |
887 | uint8_t *pkt, uint32_t pkt_caplen, | |
888 | uint32_t pkt_len, int next) | |
889 | { | |
890 | bool stop = false; | |
891 | int i = 1; | |
892 | ||
0a1b0fd9 | 893 | while (!bpf_curr.Rs && !stop) { |
fd981e3c DB |
894 | bpf_safe_regs(); |
895 | ||
896 | if (i++ == next) | |
897 | stop = bpf_handle_breakpoint(&bpf_curr, f, pkt, | |
898 | pkt_caplen, pkt_len); | |
899 | ||
900 | bpf_single_step(&bpf_curr, &f[bpf_curr.Pc], pkt, pkt_caplen, | |
901 | pkt_len); | |
902 | bpf_curr.Pc++; | |
903 | } | |
904 | ||
905 | return stop ? -1 : bpf_curr.R; | |
906 | } | |
907 | ||
908 | static bool pcap_loaded(void) | |
909 | { | |
910 | if (pcap_fd < 0) | |
911 | rl_printf("no pcap file loaded!\n"); | |
912 | ||
913 | return pcap_fd >= 0; | |
914 | } | |
915 | ||
916 | static struct pcap_pkthdr *pcap_curr_pkt(void) | |
917 | { | |
918 | return (void *) pcap_ptr_va_curr; | |
919 | } | |
920 | ||
921 | static bool pcap_next_pkt(void) | |
922 | { | |
923 | struct pcap_pkthdr *hdr = pcap_curr_pkt(); | |
924 | ||
925 | if (pcap_ptr_va_curr + sizeof(*hdr) - | |
926 | pcap_ptr_va_start >= pcap_map_size) | |
927 | return false; | |
928 | if (hdr->caplen == 0 || hdr->len == 0 || hdr->caplen > hdr->len) | |
929 | return false; | |
930 | if (pcap_ptr_va_curr + sizeof(*hdr) + hdr->caplen - | |
931 | pcap_ptr_va_start >= pcap_map_size) | |
932 | return false; | |
933 | ||
934 | pcap_ptr_va_curr += (sizeof(*hdr) + hdr->caplen); | |
935 | return true; | |
936 | } | |
937 | ||
938 | static void pcap_reset_pkt(void) | |
939 | { | |
940 | pcap_ptr_va_curr = pcap_ptr_va_start + sizeof(struct pcap_filehdr); | |
941 | } | |
942 | ||
943 | static int try_load_pcap(const char *file) | |
944 | { | |
945 | struct pcap_filehdr *hdr; | |
946 | struct stat sb; | |
947 | int ret; | |
948 | ||
949 | pcap_fd = open(file, O_RDONLY); | |
950 | if (pcap_fd < 0) { | |
951 | rl_printf("cannot open pcap [%s]!\n", strerror(errno)); | |
952 | return CMD_ERR; | |
953 | } | |
954 | ||
955 | ret = fstat(pcap_fd, &sb); | |
956 | if (ret < 0) { | |
957 | rl_printf("cannot fstat pcap file!\n"); | |
958 | return CMD_ERR; | |
959 | } | |
960 | ||
961 | if (!S_ISREG(sb.st_mode)) { | |
962 | rl_printf("not a regular pcap file, duh!\n"); | |
963 | return CMD_ERR; | |
964 | } | |
965 | ||
966 | pcap_map_size = sb.st_size; | |
967 | if (pcap_map_size <= sizeof(struct pcap_filehdr)) { | |
968 | rl_printf("pcap file too small!\n"); | |
969 | return CMD_ERR; | |
970 | } | |
971 | ||
972 | pcap_ptr_va_start = mmap(NULL, pcap_map_size, PROT_READ, | |
973 | MAP_SHARED | MAP_LOCKED, pcap_fd, 0); | |
974 | if (pcap_ptr_va_start == MAP_FAILED) { | |
975 | rl_printf("mmap of file failed!"); | |
976 | return CMD_ERR; | |
977 | } | |
978 | ||
979 | hdr = (void *) pcap_ptr_va_start; | |
980 | if (hdr->magic != TCPDUMP_MAGIC) { | |
981 | rl_printf("wrong pcap magic!\n"); | |
982 | return CMD_ERR; | |
983 | } | |
984 | ||
985 | pcap_reset_pkt(); | |
986 | ||
987 | return CMD_OK; | |
988 | ||
989 | } | |
990 | ||
991 | static void try_close_pcap(void) | |
992 | { | |
993 | if (pcap_fd >= 0) { | |
994 | munmap(pcap_ptr_va_start, pcap_map_size); | |
995 | close(pcap_fd); | |
996 | ||
997 | pcap_ptr_va_start = pcap_ptr_va_curr = NULL; | |
998 | pcap_map_size = 0; | |
999 | pcap_packet = 0; | |
1000 | pcap_fd = -1; | |
1001 | } | |
1002 | } | |
1003 | ||
1004 | static int cmd_load_bpf(char *bpf_string) | |
1005 | { | |
1006 | char sp, *token, separator = ','; | |
1007 | unsigned short bpf_len, i = 0; | |
1008 | struct sock_filter tmp; | |
1009 | ||
1010 | bpf_prog_len = 0; | |
1011 | memset(bpf_image, 0, sizeof(bpf_image)); | |
1012 | ||
1013 | if (sscanf(bpf_string, "%hu%c", &bpf_len, &sp) != 2 || | |
1014 | sp != separator || bpf_len > BPF_MAXINSNS || bpf_len == 0) { | |
1015 | rl_printf("syntax error in head length encoding!\n"); | |
1016 | return CMD_ERR; | |
1017 | } | |
1018 | ||
1019 | token = bpf_string; | |
1020 | while ((token = strchr(token, separator)) && (++token)[0]) { | |
1021 | if (i >= bpf_len) { | |
1022 | rl_printf("program exceeds encoded length!\n"); | |
1023 | return CMD_ERR; | |
1024 | } | |
1025 | ||
1026 | if (sscanf(token, "%hu %hhu %hhu %u,", | |
1027 | &tmp.code, &tmp.jt, &tmp.jf, &tmp.k) != 4) { | |
1028 | rl_printf("syntax error at instruction %d!\n", i); | |
1029 | return CMD_ERR; | |
1030 | } | |
1031 | ||
1032 | bpf_image[i].code = tmp.code; | |
1033 | bpf_image[i].jt = tmp.jt; | |
1034 | bpf_image[i].jf = tmp.jf; | |
1035 | bpf_image[i].k = tmp.k; | |
1036 | ||
1037 | i++; | |
1038 | } | |
1039 | ||
1040 | if (i != bpf_len) { | |
1041 | rl_printf("syntax error exceeding encoded length!\n"); | |
1042 | return CMD_ERR; | |
1043 | } else | |
1044 | bpf_prog_len = bpf_len; | |
1045 | if (!bpf_runnable(bpf_image, bpf_prog_len)) | |
1046 | bpf_prog_len = 0; | |
1047 | ||
1048 | return CMD_OK; | |
1049 | } | |
1050 | ||
1051 | static int cmd_load_pcap(char *file) | |
1052 | { | |
1053 | char *file_trim, *tmp; | |
1054 | ||
1055 | file_trim = strtok_r(file, " ", &tmp); | |
1056 | if (file_trim == NULL) | |
1057 | return CMD_ERR; | |
1058 | ||
1059 | try_close_pcap(); | |
1060 | ||
1061 | return try_load_pcap(file_trim); | |
1062 | } | |
1063 | ||
1064 | static int cmd_load(char *arg) | |
1065 | { | |
81542556 | 1066 | char *subcmd, *cont = NULL, *tmp = strdup(arg); |
fd981e3c DB |
1067 | int ret = CMD_OK; |
1068 | ||
1069 | subcmd = strtok_r(tmp, " ", &cont); | |
1070 | if (subcmd == NULL) | |
1071 | goto out; | |
1072 | if (matches(subcmd, "bpf") == 0) { | |
1073 | bpf_reset(); | |
1074 | bpf_reset_breakpoints(); | |
1075 | ||
81542556 JF |
1076 | if (!cont) |
1077 | ret = CMD_ERR; | |
1078 | else | |
1079 | ret = cmd_load_bpf(cont); | |
fd981e3c DB |
1080 | } else if (matches(subcmd, "pcap") == 0) { |
1081 | ret = cmd_load_pcap(cont); | |
1082 | } else { | |
1083 | out: | |
1084 | rl_printf("bpf <code>: load bpf code\n"); | |
1085 | rl_printf("pcap <file>: load pcap file\n"); | |
1086 | ret = CMD_ERR; | |
1087 | } | |
1088 | ||
1089 | free(tmp); | |
1090 | return ret; | |
1091 | } | |
1092 | ||
1093 | static int cmd_step(char *num) | |
1094 | { | |
1095 | struct pcap_pkthdr *hdr; | |
1096 | int steps, ret; | |
1097 | ||
1098 | if (!bpf_prog_loaded() || !pcap_loaded()) | |
1099 | return CMD_ERR; | |
1100 | ||
1101 | steps = strtol(num, NULL, 10); | |
1102 | if (steps == 0 || strlen(num) == 0) | |
1103 | steps = 1; | |
1104 | if (steps < 0) { | |
1105 | if (!bpf_restore_regs(steps)) | |
1106 | return CMD_ERR; | |
1107 | steps = 1; | |
1108 | } | |
1109 | ||
1110 | hdr = pcap_curr_pkt(); | |
1111 | ret = bpf_run_stepping(bpf_image, bpf_prog_len, | |
1112 | (uint8_t *) hdr + sizeof(*hdr), | |
1113 | hdr->caplen, hdr->len, steps); | |
1114 | if (ret >= 0 || bpf_curr.Rs) { | |
1115 | bpf_reset(); | |
1116 | if (!pcap_next_pkt()) { | |
1117 | rl_printf("(going back to first packet)\n"); | |
1118 | pcap_reset_pkt(); | |
1119 | } else { | |
1120 | rl_printf("(next packet)\n"); | |
1121 | } | |
1122 | } | |
1123 | ||
1124 | return CMD_OK; | |
1125 | } | |
1126 | ||
1127 | static int cmd_select(char *num) | |
1128 | { | |
1129 | unsigned int which, i; | |
fd981e3c DB |
1130 | bool have_next = true; |
1131 | ||
1132 | if (!pcap_loaded() || strlen(num) == 0) | |
1133 | return CMD_ERR; | |
1134 | ||
1135 | which = strtoul(num, NULL, 10); | |
1136 | if (which == 0) { | |
1137 | rl_printf("packet count starts with 1, clamping!\n"); | |
1138 | which = 1; | |
1139 | } | |
1140 | ||
1141 | pcap_reset_pkt(); | |
1142 | bpf_reset(); | |
1143 | ||
1144 | for (i = 0; i < which && (have_next = pcap_next_pkt()); i++) | |
1145 | /* noop */; | |
7debf780 | 1146 | if (!have_next || pcap_curr_pkt() == NULL) { |
fd981e3c DB |
1147 | rl_printf("no packet #%u available!\n", which); |
1148 | pcap_reset_pkt(); | |
1149 | return CMD_ERR; | |
1150 | } | |
1151 | ||
1152 | return CMD_OK; | |
1153 | } | |
1154 | ||
1155 | static int cmd_breakpoint(char *subcmd) | |
1156 | { | |
1157 | if (!bpf_prog_loaded()) | |
1158 | return CMD_ERR; | |
1159 | if (strlen(subcmd) == 0) | |
1160 | bpf_dump_breakpoints(); | |
1161 | else if (matches(subcmd, "reset") == 0) | |
1162 | bpf_reset_breakpoints(); | |
1163 | else { | |
1164 | unsigned int where = strtoul(subcmd, NULL, 10); | |
1165 | ||
1166 | if (where < bpf_prog_len) { | |
1167 | bpf_set_breakpoints(where); | |
1168 | rl_printf("breakpoint at: "); | |
1169 | bpf_disasm(bpf_image[where], where); | |
1170 | } | |
1171 | } | |
1172 | ||
1173 | return CMD_OK; | |
1174 | } | |
1175 | ||
1176 | static int cmd_run(char *num) | |
1177 | { | |
1490d2bd | 1178 | static uint32_t pass, fail; |
fd981e3c | 1179 | bool has_limit = true; |
7debf780 | 1180 | int pkts = 0, i = 0; |
fd981e3c DB |
1181 | |
1182 | if (!bpf_prog_loaded() || !pcap_loaded()) | |
1183 | return CMD_ERR; | |
1184 | ||
1185 | pkts = strtol(num, NULL, 10); | |
1186 | if (pkts == 0 || strlen(num) == 0) | |
1187 | has_limit = false; | |
1188 | ||
1189 | do { | |
7debf780 DB |
1190 | struct pcap_pkthdr *hdr = pcap_curr_pkt(); |
1191 | int ret = bpf_run_all(bpf_image, bpf_prog_len, | |
1192 | (uint8_t *) hdr + sizeof(*hdr), | |
1193 | hdr->caplen, hdr->len); | |
fd981e3c DB |
1194 | if (ret > 0) |
1195 | pass++; | |
1196 | else if (ret == 0) | |
1197 | fail++; | |
1198 | else | |
1199 | return CMD_OK; | |
1200 | bpf_reset(); | |
46ac034f | 1201 | } while (pcap_next_pkt() && (!has_limit || (++i < pkts))); |
fd981e3c DB |
1202 | |
1203 | rl_printf("bpf passes:%u fails:%u\n", pass, fail); | |
1204 | ||
1205 | pcap_reset_pkt(); | |
1206 | bpf_reset(); | |
1207 | ||
1208 | pass = fail = 0; | |
1209 | return CMD_OK; | |
1210 | } | |
1211 | ||
1212 | static int cmd_disassemble(char *line_string) | |
1213 | { | |
1214 | bool single_line = false; | |
1215 | unsigned long line; | |
1216 | ||
1217 | if (!bpf_prog_loaded()) | |
1218 | return CMD_ERR; | |
1219 | if (strlen(line_string) > 0 && | |
1220 | (line = strtoul(line_string, NULL, 10)) < bpf_prog_len) | |
1221 | single_line = true; | |
1222 | if (single_line) | |
1223 | bpf_disasm(bpf_image[line], line); | |
1224 | else | |
1225 | bpf_disasm_all(bpf_image, bpf_prog_len); | |
1226 | ||
1227 | return CMD_OK; | |
1228 | } | |
1229 | ||
1230 | static int cmd_dump(char *dontcare) | |
1231 | { | |
1232 | if (!bpf_prog_loaded()) | |
1233 | return CMD_ERR; | |
1234 | ||
1235 | bpf_dump_all(bpf_image, bpf_prog_len); | |
1236 | ||
1237 | return CMD_OK; | |
1238 | } | |
1239 | ||
1240 | static int cmd_quit(char *dontcare) | |
1241 | { | |
1242 | return CMD_EX; | |
1243 | } | |
1244 | ||
1245 | static const struct shell_cmd cmds[] = { | |
7debf780 DB |
1246 | { .name = "load", .func = cmd_load }, |
1247 | { .name = "select", .func = cmd_select }, | |
1248 | { .name = "step", .func = cmd_step }, | |
1249 | { .name = "run", .func = cmd_run }, | |
1250 | { .name = "breakpoint", .func = cmd_breakpoint }, | |
1251 | { .name = "disassemble", .func = cmd_disassemble }, | |
1252 | { .name = "dump", .func = cmd_dump }, | |
1253 | { .name = "quit", .func = cmd_quit }, | |
fd981e3c DB |
1254 | }; |
1255 | ||
1256 | static int execf(char *arg) | |
1257 | { | |
1258 | char *cmd, *cont, *tmp = strdup(arg); | |
1259 | int i, ret = 0, len; | |
1260 | ||
1261 | cmd = strtok_r(tmp, " ", &cont); | |
1262 | if (cmd == NULL) | |
1263 | goto out; | |
1264 | len = strlen(cmd); | |
1265 | for (i = 0; i < array_size(cmds); i++) { | |
1266 | if (len != strlen(cmds[i].name)) | |
1267 | continue; | |
1268 | if (strncmp(cmds[i].name, cmd, len) == 0) { | |
1269 | ret = cmds[i].func(cont); | |
1270 | break; | |
1271 | } | |
1272 | } | |
1273 | out: | |
1274 | free(tmp); | |
1275 | return ret; | |
1276 | } | |
1277 | ||
1278 | static char *shell_comp_gen(const char *buf, int state) | |
1279 | { | |
1280 | static int list_index, len; | |
fd981e3c DB |
1281 | |
1282 | if (!state) { | |
1283 | list_index = 0; | |
1284 | len = strlen(buf); | |
1285 | } | |
1286 | ||
1287 | for (; list_index < array_size(cmds); ) { | |
7debf780 | 1288 | const char *name = cmds[list_index].name; |
fd981e3c | 1289 | |
7debf780 | 1290 | list_index++; |
fd981e3c DB |
1291 | if (strncmp(name, buf, len) == 0) |
1292 | return strdup(name); | |
1293 | } | |
1294 | ||
1295 | return NULL; | |
1296 | } | |
1297 | ||
1298 | static char **shell_completion(const char *buf, int start, int end) | |
1299 | { | |
1300 | char **matches = NULL; | |
1301 | ||
1302 | if (start == 0) | |
1303 | matches = rl_completion_matches(buf, shell_comp_gen); | |
1304 | ||
1305 | return matches; | |
1306 | } | |
1307 | ||
1308 | static void intr_shell(int sig) | |
1309 | { | |
1310 | if (rl_end) | |
1311 | rl_kill_line(-1, 0); | |
1312 | ||
1313 | rl_crlf(); | |
1314 | rl_refresh_line(0, 0); | |
1315 | rl_free_line_state(); | |
1316 | } | |
1317 | ||
1318 | static void init_shell(FILE *fin, FILE *fout) | |
1319 | { | |
1320 | char file[128]; | |
1321 | ||
7debf780 | 1322 | snprintf(file, sizeof(file), "%s/.bpf_dbg_history", getenv("HOME")); |
fd981e3c DB |
1323 | read_history(file); |
1324 | ||
fd981e3c DB |
1325 | rl_instream = fin; |
1326 | rl_outstream = fout; | |
1327 | ||
1328 | rl_readline_name = "bpf_dbg"; | |
1329 | rl_terminal_name = getenv("TERM"); | |
1330 | ||
1331 | rl_catch_signals = 0; | |
1332 | rl_catch_sigwinch = 1; | |
1333 | ||
1334 | rl_attempted_completion_function = shell_completion; | |
1335 | ||
1336 | rl_bind_key('\t', rl_complete); | |
1337 | ||
1338 | rl_bind_key_in_map('\t', rl_complete, emacs_meta_keymap); | |
1339 | rl_bind_key_in_map('\033', rl_complete, emacs_meta_keymap); | |
1340 | ||
7debf780 | 1341 | snprintf(file, sizeof(file), "%s/.bpf_dbg_init", getenv("HOME")); |
fd981e3c | 1342 | rl_read_init_file(file); |
7debf780 | 1343 | |
fd981e3c DB |
1344 | rl_prep_terminal(0); |
1345 | rl_set_signals(); | |
1346 | ||
1347 | signal(SIGINT, intr_shell); | |
1348 | } | |
1349 | ||
7debf780 | 1350 | static void exit_shell(FILE *fin, FILE *fout) |
fd981e3c DB |
1351 | { |
1352 | char file[128]; | |
1353 | ||
7debf780 | 1354 | snprintf(file, sizeof(file), "%s/.bpf_dbg_history", getenv("HOME")); |
fd981e3c | 1355 | write_history(file); |
7debf780 | 1356 | |
fd981e3c DB |
1357 | clear_history(); |
1358 | rl_deprep_terminal(); | |
1359 | ||
1360 | try_close_pcap(); | |
7debf780 DB |
1361 | |
1362 | if (fin != stdin) | |
1363 | fclose(fin); | |
1364 | if (fout != stdout) | |
1365 | fclose(fout); | |
fd981e3c DB |
1366 | } |
1367 | ||
1368 | static int run_shell_loop(FILE *fin, FILE *fout) | |
1369 | { | |
1370 | char *buf; | |
fd981e3c DB |
1371 | |
1372 | init_shell(fin, fout); | |
1373 | ||
1374 | while ((buf = readline("> ")) != NULL) { | |
7debf780 | 1375 | int ret = execf(buf); |
fd981e3c DB |
1376 | if (ret == CMD_EX) |
1377 | break; | |
1378 | if (ret == CMD_OK && strlen(buf) > 0) | |
1379 | add_history(buf); | |
1380 | ||
1381 | free(buf); | |
1382 | } | |
1383 | ||
7debf780 | 1384 | exit_shell(fin, fout); |
fd981e3c DB |
1385 | return 0; |
1386 | } | |
1387 | ||
1388 | int main(int argc, char **argv) | |
1389 | { | |
1390 | FILE *fin = NULL, *fout = NULL; | |
1391 | ||
1392 | if (argc >= 2) | |
1393 | fin = fopen(argv[1], "r"); | |
1394 | if (argc >= 3) | |
1395 | fout = fopen(argv[2], "w"); | |
1396 | ||
1397 | return run_shell_loop(fin ? : stdin, fout ? : stdout); | |
1398 | } |