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Commit | Line | Data |
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7a473c77 SH |
1 | /* |
2 | * m_ematch.c Extended Matches | |
3 | * | |
4 | * This program is free software; you can distribute it and/or | |
5 | * modify it under the terms of the GNU General Public License | |
6 | * as published by the Free Software Foundation; either version | |
7 | * 2 of the License, or (at your option) any later version. | |
8 | * | |
9 | * Authors: Thomas Graf <tgraf@suug.ch> | |
10 | */ | |
11 | ||
12 | #include <stdio.h> | |
13 | #include <stdlib.h> | |
14 | #include <unistd.h> | |
7a473c77 SH |
15 | #include <fcntl.h> |
16 | #include <sys/socket.h> | |
17 | #include <netinet/in.h> | |
18 | #include <arpa/inet.h> | |
19 | #include <string.h> | |
20 | #include <dlfcn.h> | |
21 | #include <stdarg.h> | |
22 | #include <errno.h> | |
23 | ||
24 | #include "utils.h" | |
25 | #include "tc_util.h" | |
26 | #include "m_ematch.h" | |
27 | ||
28 | #define EMATCH_MAP "/etc/iproute2/ematch_map" | |
29 | ||
30 | static struct ematch_util *ematch_list; | |
31 | ||
32 | /* export to bison parser */ | |
33 | int ematch_argc; | |
34 | char **ematch_argv; | |
32a121cb | 35 | char *ematch_err; |
7a473c77 SH |
36 | struct ematch *ematch_root; |
37 | ||
38 | static int begin_argc; | |
39 | static char **begin_argv; | |
40 | ||
41 | static inline void map_warning(int num, char *kind) | |
42 | { | |
43 | fprintf(stderr, | |
44 | "Error: Unable to find ematch \"%s\" in %s\n" \ | |
45 | "Please assign a unique ID to the ematch kind the suggested " \ | |
46 | "entry is:\n" \ | |
ae665a52 | 47 | "\t%d\t%s\n", |
7a473c77 SH |
48 | kind, EMATCH_MAP, num, kind); |
49 | } | |
50 | ||
51 | static int lookup_map(__u16 num, char *dst, int len, const char *file) | |
52 | { | |
53 | int err = -EINVAL; | |
54 | char buf[512]; | |
55 | FILE *fd = fopen(file, "r"); | |
56 | ||
57 | if (fd == NULL) | |
58 | return -errno; | |
59 | ||
60 | while (fgets(buf, sizeof(buf), fd)) { | |
61 | char namebuf[512], *p = buf; | |
62 | int id; | |
63 | ||
64 | while (*p == ' ' || *p == '\t') | |
65 | p++; | |
66 | if (*p == '#' || *p == '\n' || *p == 0) | |
67 | continue; | |
ae665a52 | 68 | |
7a473c77 SH |
69 | if (sscanf(p, "%d %s", &id, namebuf) != 2) { |
70 | fprintf(stderr, "ematch map %s corrupted at %s\n", | |
71 | file, p); | |
72 | goto out; | |
73 | } | |
74 | ||
75 | if (id == num) { | |
76 | if (dst) | |
77 | strncpy(dst, namebuf, len - 1); | |
78 | err = 0; | |
79 | goto out; | |
80 | } | |
81 | } | |
82 | ||
83 | err = -ENOENT; | |
84 | out: | |
85 | fclose(fd); | |
86 | return err; | |
87 | } | |
88 | ||
89 | static int lookup_map_id(char *kind, int *dst, const char *file) | |
90 | { | |
91 | int err = -EINVAL; | |
92 | char buf[512]; | |
93 | FILE *fd = fopen(file, "r"); | |
94 | ||
95 | if (fd == NULL) | |
96 | return -errno; | |
97 | ||
98 | while (fgets(buf, sizeof(buf), fd)) { | |
99 | char namebuf[512], *p = buf; | |
100 | int id; | |
101 | ||
102 | while (*p == ' ' || *p == '\t') | |
103 | p++; | |
104 | if (*p == '#' || *p == '\n' || *p == 0) | |
105 | continue; | |
ae665a52 | 106 | |
7a473c77 SH |
107 | if (sscanf(p, "%d %s", &id, namebuf) != 2) { |
108 | fprintf(stderr, "ematch map %s corrupted at %s\n", | |
109 | file, p); | |
110 | goto out; | |
111 | } | |
112 | ||
113 | if (!strcasecmp(namebuf, kind)) { | |
114 | if (dst) | |
115 | *dst = id; | |
116 | err = 0; | |
117 | goto out; | |
118 | } | |
119 | } | |
120 | ||
121 | err = -ENOENT; | |
f332d169 | 122 | *dst = 0; |
7a473c77 SH |
123 | out: |
124 | fclose(fd); | |
125 | return err; | |
126 | } | |
127 | ||
128 | static struct ematch_util *get_ematch_kind(char *kind) | |
129 | { | |
130 | static void *body; | |
131 | void *dlh; | |
132 | char buf[256]; | |
133 | struct ematch_util *e; | |
134 | ||
135 | for (e = ematch_list; e; e = e->next) { | |
136 | if (strcmp(e->kind, kind) == 0) | |
137 | return e; | |
138 | } | |
139 | ||
140 | snprintf(buf, sizeof(buf), "em_%s.so", kind); | |
141 | dlh = dlopen(buf, RTLD_LAZY); | |
142 | if (dlh == NULL) { | |
143 | dlh = body; | |
144 | if (dlh == NULL) { | |
145 | dlh = body = dlopen(NULL, RTLD_LAZY); | |
146 | if (dlh == NULL) | |
147 | return NULL; | |
148 | } | |
149 | } | |
150 | ||
151 | snprintf(buf, sizeof(buf), "%s_ematch_util", kind); | |
152 | e = dlsym(dlh, buf); | |
153 | if (e == NULL) | |
154 | return NULL; | |
155 | ||
156 | e->next = ematch_list; | |
157 | ematch_list = e; | |
158 | ||
159 | return e; | |
160 | } | |
161 | ||
162 | static struct ematch_util *get_ematch_kind_num(__u16 kind) | |
163 | { | |
d5732e34 | 164 | char name[513]; |
7a473c77 SH |
165 | |
166 | if (lookup_map(kind, name, sizeof(name), EMATCH_MAP) < 0) | |
167 | return NULL; | |
168 | ||
169 | return get_ematch_kind(name); | |
7a473c77 SH |
170 | } |
171 | ||
52686203 EB |
172 | static int em_parse_call(struct nlmsghdr *n, struct tcf_ematch_hdr *hdr, |
173 | struct ematch_util *e, struct ematch *t) | |
174 | { | |
175 | if (e->parse_eopt_argv) { | |
176 | int argc = 0, i = 0, ret; | |
177 | struct bstr *args; | |
178 | char **argv; | |
179 | ||
180 | for (args = t->args; args; args = bstr_next(args)) | |
181 | argc++; | |
182 | argv = calloc(argc, sizeof(char *)); | |
183 | if (!argv) | |
184 | return -1; | |
185 | for (args = t->args; args; args = bstr_next(args)) | |
186 | argv[i++] = args->data; | |
187 | ||
188 | ret = e->parse_eopt_argv(n, hdr, argc, argv); | |
189 | ||
190 | free(argv); | |
191 | return ret; | |
192 | } | |
193 | ||
194 | return e->parse_eopt(n, hdr, t->args->next); | |
195 | } | |
196 | ||
7a473c77 SH |
197 | static int parse_tree(struct nlmsghdr *n, struct ematch *tree) |
198 | { | |
199 | int index = 1; | |
200 | struct ematch *t; | |
201 | ||
202 | for (t = tree; t; t = t->next) { | |
c14f9d92 | 203 | struct rtattr *tail; |
d17b136f | 204 | struct tcf_ematch_hdr hdr = { .flags = t->relation }; |
7a473c77 SH |
205 | |
206 | if (t->inverted) | |
207 | hdr.flags |= TCF_EM_INVERT; | |
ae665a52 | 208 | |
c14f9d92 | 209 | tail = addattr_nest(n, MAX_MSG, index++); |
7a473c77 SH |
210 | |
211 | if (t->child) { | |
212 | __u32 r = t->child_ref; | |
32a121cb | 213 | |
7a473c77 SH |
214 | addraw_l(n, MAX_MSG, &hdr, sizeof(hdr)); |
215 | addraw_l(n, MAX_MSG, &r, sizeof(r)); | |
216 | } else { | |
3fcdebb6 | 217 | int num = 0, err; |
7a473c77 SH |
218 | char buf[64]; |
219 | struct ematch_util *e; | |
220 | ||
221 | if (t->args == NULL) | |
222 | return -1; | |
223 | ||
32a121cb | 224 | strncpy(buf, (char *) t->args->data, sizeof(buf)-1); |
7a473c77 SH |
225 | e = get_ematch_kind(buf); |
226 | if (e == NULL) { | |
227 | fprintf(stderr, "Unknown ematch \"%s\"\n", | |
228 | buf); | |
229 | return -1; | |
230 | } | |
231 | ||
232 | err = lookup_map_id(buf, &num, EMATCH_MAP); | |
233 | if (err < 0) { | |
234 | if (err == -ENOENT) | |
235 | map_warning(e->kind_num, buf); | |
236 | return err; | |
237 | } | |
238 | ||
239 | hdr.kind = num; | |
52686203 | 240 | if (em_parse_call(n, &hdr, e, t) < 0) |
7a473c77 SH |
241 | return -1; |
242 | } | |
243 | ||
c14f9d92 | 244 | addattr_nest_end(n, tail); |
7a473c77 SH |
245 | } |
246 | ||
247 | return 0; | |
248 | } | |
249 | ||
250 | static int flatten_tree(struct ematch *head, struct ematch *tree) | |
251 | { | |
252 | int i, count = 0; | |
253 | struct ematch *t; | |
254 | ||
255 | for (;;) { | |
256 | count++; | |
257 | ||
258 | if (tree->child) { | |
259 | for (t = head; t->next; t = t->next); | |
260 | t->next = tree->child; | |
261 | count += flatten_tree(head, tree->child); | |
262 | } | |
263 | ||
264 | if (tree->relation == 0) | |
265 | break; | |
266 | ||
267 | tree = tree->next; | |
268 | } | |
269 | ||
270 | for (i = 0, t = head; t; t = t->next, i++) | |
271 | t->index = i; | |
272 | ||
273 | for (t = head; t; t = t->next) | |
274 | if (t->child) | |
275 | t->child_ref = t->child->index; | |
276 | ||
277 | return count; | |
278 | } | |
279 | ||
5d5586b0 | 280 | __attribute__((format(printf, 5, 6))) |
7a473c77 SH |
281 | int em_parse_error(int err, struct bstr *args, struct bstr *carg, |
282 | struct ematch_util *e, char *fmt, ...) | |
283 | { | |
284 | va_list a; | |
285 | ||
286 | va_start(a, fmt); | |
287 | vfprintf(stderr, fmt, a); | |
288 | va_end(a); | |
289 | ||
290 | if (ematch_err) | |
291 | fprintf(stderr, ": %s\n... ", ematch_err); | |
292 | else | |
293 | fprintf(stderr, "\n... "); | |
294 | ||
295 | while (ematch_argc < begin_argc) { | |
296 | if (ematch_argc == (begin_argc - 1)) | |
297 | fprintf(stderr, ">>%s<< ", *begin_argv); | |
298 | else | |
299 | fprintf(stderr, "%s ", *begin_argv); | |
300 | begin_argv++; | |
301 | begin_argc--; | |
302 | } | |
ae665a52 | 303 | |
7a473c77 SH |
304 | fprintf(stderr, "...\n"); |
305 | ||
306 | if (args) { | |
307 | fprintf(stderr, "... %s(", e->kind); | |
308 | while (args) { | |
309 | fprintf(stderr, "%s", args == carg ? ">>" : ""); | |
310 | bstr_print(stderr, args, 1); | |
311 | fprintf(stderr, "%s%s", args == carg ? "<<" : "", | |
312 | args->next ? " " : ""); | |
313 | args = args->next; | |
314 | } | |
315 | fprintf(stderr, ")...\n"); | |
316 | ||
317 | } | |
318 | ||
319 | if (e == NULL) { | |
320 | fprintf(stderr, | |
321 | "Usage: EXPR\n" \ | |
322 | "where: EXPR := TERM [ { and | or } EXPR ]\n" \ | |
323 | " TERM := [ not ] { MATCH | '(' EXPR ')' }\n" \ | |
324 | " MATCH := module '(' ARGS ')'\n" \ | |
325 | " ARGS := ARG1 ARG2 ...\n" \ | |
326 | "\n" \ | |
327 | "Example: a(x y) and not (b(x) or c(x y z))\n"); | |
328 | } else | |
329 | e->print_usage(stderr); | |
330 | ||
331 | return -err; | |
332 | } | |
333 | ||
334 | static inline void free_ematch_err(void) | |
335 | { | |
336 | if (ematch_err) { | |
337 | free(ematch_err); | |
338 | ematch_err = NULL; | |
339 | } | |
340 | } | |
341 | ||
342 | extern int ematch_parse(void); | |
343 | ||
344 | int parse_ematch(int *argc_p, char ***argv_p, int tca_id, struct nlmsghdr *n) | |
345 | { | |
346 | begin_argc = ematch_argc = *argc_p; | |
347 | begin_argv = ematch_argv = *argv_p; | |
348 | ||
349 | if (ematch_parse()) { | |
350 | int err = em_parse_error(EINVAL, NULL, NULL, NULL, | |
351 | "Parse error"); | |
352 | free_ematch_err(); | |
353 | return err; | |
354 | } | |
355 | ||
356 | free_ematch_err(); | |
357 | ||
358 | /* undo look ahead by parser */ | |
359 | ematch_argc++; | |
360 | ematch_argv--; | |
361 | ||
362 | if (ematch_root) { | |
363 | struct rtattr *tail, *tail_list; | |
364 | ||
365 | struct tcf_ematch_tree_hdr hdr = { | |
366 | .nmatches = flatten_tree(ematch_root, ematch_root), | |
367 | .progid = TCF_EM_PROG_TC | |
368 | }; | |
369 | ||
c14f9d92 | 370 | tail = addattr_nest(n, MAX_MSG, tca_id); |
7a473c77 SH |
371 | addattr_l(n, MAX_MSG, TCA_EMATCH_TREE_HDR, &hdr, sizeof(hdr)); |
372 | ||
c14f9d92 | 373 | tail_list = addattr_nest(n, MAX_MSG, TCA_EMATCH_TREE_LIST); |
7a473c77 SH |
374 | |
375 | if (parse_tree(n, ematch_root) < 0) | |
376 | return -1; | |
377 | ||
c14f9d92 SP |
378 | addattr_nest_end(n, tail_list); |
379 | addattr_nest_end(n, tail); | |
7a473c77 SH |
380 | } |
381 | ||
382 | *argc_p = ematch_argc; | |
383 | *argv_p = ematch_argv; | |
384 | ||
385 | return 0; | |
386 | } | |
387 | ||
388 | static int print_ematch_seq(FILE *fd, struct rtattr **tb, int start, | |
389 | int prefix) | |
390 | { | |
391 | int n, i = start; | |
392 | struct tcf_ematch_hdr *hdr; | |
393 | int dlen; | |
394 | void *data; | |
395 | ||
396 | for (;;) { | |
397 | if (tb[i] == NULL) | |
398 | return -1; | |
399 | ||
400 | dlen = RTA_PAYLOAD(tb[i]) - sizeof(*hdr); | |
401 | data = (void *) RTA_DATA(tb[i]) + sizeof(*hdr); | |
402 | ||
403 | if (dlen < 0) | |
404 | return -1; | |
405 | ||
406 | hdr = RTA_DATA(tb[i]); | |
407 | ||
408 | if (hdr->flags & TCF_EM_INVERT) | |
409 | fprintf(fd, "NOT "); | |
410 | ||
411 | if (hdr->kind == 0) { | |
412 | __u32 ref; | |
413 | ||
414 | if (dlen < sizeof(__u32)) | |
415 | return -1; | |
416 | ||
417 | ref = *(__u32 *) data; | |
418 | fprintf(fd, "(\n"); | |
419 | for (n = 0; n <= prefix; n++) | |
420 | fprintf(fd, " "); | |
421 | if (print_ematch_seq(fd, tb, ref + 1, prefix + 1) < 0) | |
422 | return -1; | |
423 | for (n = 0; n < prefix; n++) | |
424 | fprintf(fd, " "); | |
425 | fprintf(fd, ") "); | |
426 | ||
427 | } else { | |
428 | struct ematch_util *e; | |
429 | ||
430 | e = get_ematch_kind_num(hdr->kind); | |
431 | if (e == NULL) | |
432 | fprintf(fd, "[unknown ematch %d]\n", | |
433 | hdr->kind); | |
434 | else { | |
435 | fprintf(fd, "%s(", e->kind); | |
436 | if (e->print_eopt(fd, hdr, data, dlen) < 0) | |
437 | return -1; | |
438 | fprintf(fd, ")\n"); | |
439 | } | |
440 | if (hdr->flags & TCF_EM_REL_MASK) | |
441 | for (n = 0; n < prefix; n++) | |
442 | fprintf(fd, " "); | |
443 | } | |
444 | ||
445 | switch (hdr->flags & TCF_EM_REL_MASK) { | |
446 | case TCF_EM_REL_AND: | |
447 | fprintf(fd, "AND "); | |
448 | break; | |
449 | ||
450 | case TCF_EM_REL_OR: | |
451 | fprintf(fd, "OR "); | |
452 | break; | |
453 | ||
454 | default: | |
455 | return 0; | |
456 | } | |
457 | ||
458 | i++; | |
459 | } | |
ae665a52 | 460 | |
7a473c77 SH |
461 | return 0; |
462 | } | |
463 | ||
464 | static int print_ematch_list(FILE *fd, struct tcf_ematch_tree_hdr *hdr, | |
465 | struct rtattr *rta) | |
466 | { | |
467 | int err = -1; | |
468 | struct rtattr **tb; | |
469 | ||
470 | tb = malloc((hdr->nmatches + 1) * sizeof(struct rtattr *)); | |
471 | if (tb == NULL) | |
472 | return -1; | |
473 | ||
4b45abd1 SH |
474 | if (hdr->nmatches > 0) { |
475 | if (parse_rtattr_nested(tb, hdr->nmatches, rta) < 0) | |
476 | goto errout; | |
7a473c77 | 477 | |
4b45abd1 SH |
478 | fprintf(fd, "\n "); |
479 | if (print_ematch_seq(fd, tb, 1, 1) < 0) | |
480 | goto errout; | |
481 | } | |
7a473c77 SH |
482 | |
483 | err = 0; | |
484 | errout: | |
485 | free(tb); | |
486 | return err; | |
487 | } | |
488 | ||
489 | int print_ematch(FILE *fd, const struct rtattr *rta) | |
490 | { | |
491 | struct rtattr *tb[TCA_EMATCH_TREE_MAX+1]; | |
492 | struct tcf_ematch_tree_hdr *hdr; | |
493 | ||
494 | if (parse_rtattr_nested(tb, TCA_EMATCH_TREE_MAX, rta) < 0) | |
495 | return -1; | |
496 | ||
497 | if (tb[TCA_EMATCH_TREE_HDR] == NULL) { | |
498 | fprintf(stderr, "Missing ematch tree header\n"); | |
499 | return -1; | |
500 | } | |
501 | ||
502 | if (tb[TCA_EMATCH_TREE_LIST] == NULL) { | |
503 | fprintf(stderr, "Missing ematch tree list\n"); | |
504 | return -1; | |
505 | } | |
506 | ||
507 | if (RTA_PAYLOAD(tb[TCA_EMATCH_TREE_HDR]) < sizeof(*hdr)) { | |
508 | fprintf(stderr, "Ematch tree header size mismatch\n"); | |
509 | return -1; | |
510 | } | |
511 | ||
512 | hdr = RTA_DATA(tb[TCA_EMATCH_TREE_HDR]); | |
513 | ||
514 | return print_ematch_list(fd, hdr, tb[TCA_EMATCH_TREE_LIST]); | |
515 | } | |
b6da1afc | 516 | |
32a121cb | 517 | struct bstr *bstr_alloc(const char *text) |
b6da1afc SH |
518 | { |
519 | struct bstr *b = calloc(1, sizeof(*b)); | |
520 | ||
521 | if (b == NULL) | |
522 | return NULL; | |
523 | ||
524 | b->data = strdup(text); | |
525 | if (b->data == NULL) { | |
526 | free(b); | |
527 | return NULL; | |
528 | } | |
529 | ||
530 | b->len = strlen(text); | |
531 | ||
532 | return b; | |
533 | } | |
534 | ||
535 | unsigned long bstrtoul(const struct bstr *b) | |
536 | { | |
537 | char *inv = NULL; | |
538 | unsigned long l; | |
539 | char buf[b->len+1]; | |
540 | ||
541 | memcpy(buf, b->data, b->len); | |
542 | buf[b->len] = '\0'; | |
543 | ||
544 | l = strtoul(buf, &inv, 0); | |
545 | if (l == ULONG_MAX || inv == buf) | |
546 | return ULONG_MAX; | |
547 | ||
548 | return l; | |
549 | } | |
550 | ||
551 | void bstr_print(FILE *fd, const struct bstr *b, int ascii) | |
552 | { | |
553 | int i; | |
554 | char *s = b->data; | |
555 | ||
556 | if (ascii) | |
557 | for (i = 0; i < b->len; i++) | |
558 | fprintf(fd, "%c", isprint(s[i]) ? s[i] : '.'); | |
559 | else { | |
560 | for (i = 0; i < b->len; i++) | |
561 | fprintf(fd, "%02x", s[i]); | |
562 | fprintf(fd, "\""); | |
563 | for (i = 0; i < b->len; i++) | |
564 | fprintf(fd, "%c", isprint(s[i]) ? s[i] : '.'); | |
565 | fprintf(fd, "\""); | |
566 | } | |
567 | } | |
568 | ||
569 | void print_ematch_tree(const struct ematch *tree) | |
570 | { | |
571 | const struct ematch *t; | |
572 | ||
573 | for (t = tree; t; t = t->next) { | |
574 | if (t->inverted) | |
575 | printf("NOT "); | |
576 | ||
577 | if (t->child) { | |
578 | printf("("); | |
579 | print_ematch_tree(t->child); | |
580 | printf(")"); | |
581 | } else { | |
582 | struct bstr *b; | |
32a121cb | 583 | |
b6da1afc SH |
584 | for (b = t->args; b; b = b->next) |
585 | printf("%s%s", b->data, b->next ? " " : ""); | |
586 | } | |
587 | ||
588 | if (t->relation == TCF_EM_REL_AND) | |
589 | printf(" AND "); | |
590 | else if (t->relation == TCF_EM_REL_OR) | |
591 | printf(" OR "); | |
592 | } | |
593 | } |