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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 | ||
33043dfc SH |
41 | static void bstr_print(FILE *fd, const struct bstr *b, int ascii); |
42 | ||
7a473c77 SH |
43 | static inline void map_warning(int num, char *kind) |
44 | { | |
45 | fprintf(stderr, | |
46 | "Error: Unable to find ematch \"%s\" in %s\n" \ | |
47 | "Please assign a unique ID to the ematch kind the suggested " \ | |
48 | "entry is:\n" \ | |
ae665a52 | 49 | "\t%d\t%s\n", |
7a473c77 SH |
50 | kind, EMATCH_MAP, num, kind); |
51 | } | |
52 | ||
53 | static int lookup_map(__u16 num, char *dst, int len, const char *file) | |
54 | { | |
55 | int err = -EINVAL; | |
56 | char buf[512]; | |
57 | FILE *fd = fopen(file, "r"); | |
58 | ||
59 | if (fd == NULL) | |
60 | return -errno; | |
61 | ||
62 | while (fgets(buf, sizeof(buf), fd)) { | |
63 | char namebuf[512], *p = buf; | |
64 | int id; | |
65 | ||
66 | while (*p == ' ' || *p == '\t') | |
67 | p++; | |
68 | if (*p == '#' || *p == '\n' || *p == 0) | |
69 | continue; | |
ae665a52 | 70 | |
7a473c77 SH |
71 | if (sscanf(p, "%d %s", &id, namebuf) != 2) { |
72 | fprintf(stderr, "ematch map %s corrupted at %s\n", | |
73 | file, p); | |
74 | goto out; | |
75 | } | |
76 | ||
77 | if (id == num) { | |
78 | if (dst) | |
79 | strncpy(dst, namebuf, len - 1); | |
80 | err = 0; | |
81 | goto out; | |
82 | } | |
83 | } | |
84 | ||
85 | err = -ENOENT; | |
86 | out: | |
87 | fclose(fd); | |
88 | return err; | |
89 | } | |
90 | ||
91 | static int lookup_map_id(char *kind, int *dst, const char *file) | |
92 | { | |
93 | int err = -EINVAL; | |
94 | char buf[512]; | |
95 | FILE *fd = fopen(file, "r"); | |
96 | ||
97 | if (fd == NULL) | |
98 | return -errno; | |
99 | ||
100 | while (fgets(buf, sizeof(buf), fd)) { | |
101 | char namebuf[512], *p = buf; | |
102 | int id; | |
103 | ||
104 | while (*p == ' ' || *p == '\t') | |
105 | p++; | |
106 | if (*p == '#' || *p == '\n' || *p == 0) | |
107 | continue; | |
ae665a52 | 108 | |
7a473c77 SH |
109 | if (sscanf(p, "%d %s", &id, namebuf) != 2) { |
110 | fprintf(stderr, "ematch map %s corrupted at %s\n", | |
111 | file, p); | |
112 | goto out; | |
113 | } | |
114 | ||
115 | if (!strcasecmp(namebuf, kind)) { | |
116 | if (dst) | |
117 | *dst = id; | |
118 | err = 0; | |
119 | goto out; | |
120 | } | |
121 | } | |
122 | ||
123 | err = -ENOENT; | |
f332d169 | 124 | *dst = 0; |
7a473c77 SH |
125 | out: |
126 | fclose(fd); | |
127 | return err; | |
128 | } | |
129 | ||
130 | static struct ematch_util *get_ematch_kind(char *kind) | |
131 | { | |
132 | static void *body; | |
133 | void *dlh; | |
134 | char buf[256]; | |
135 | struct ematch_util *e; | |
136 | ||
137 | for (e = ematch_list; e; e = e->next) { | |
138 | if (strcmp(e->kind, kind) == 0) | |
139 | return e; | |
140 | } | |
141 | ||
142 | snprintf(buf, sizeof(buf), "em_%s.so", kind); | |
143 | dlh = dlopen(buf, RTLD_LAZY); | |
144 | if (dlh == NULL) { | |
145 | dlh = body; | |
146 | if (dlh == NULL) { | |
147 | dlh = body = dlopen(NULL, RTLD_LAZY); | |
148 | if (dlh == NULL) | |
149 | return NULL; | |
150 | } | |
151 | } | |
152 | ||
153 | snprintf(buf, sizeof(buf), "%s_ematch_util", kind); | |
154 | e = dlsym(dlh, buf); | |
155 | if (e == NULL) | |
156 | return NULL; | |
157 | ||
158 | e->next = ematch_list; | |
159 | ematch_list = e; | |
160 | ||
161 | return e; | |
162 | } | |
163 | ||
164 | static struct ematch_util *get_ematch_kind_num(__u16 kind) | |
165 | { | |
d5732e34 | 166 | char name[513]; |
7a473c77 SH |
167 | |
168 | if (lookup_map(kind, name, sizeof(name), EMATCH_MAP) < 0) | |
169 | return NULL; | |
170 | ||
171 | return get_ematch_kind(name); | |
7a473c77 SH |
172 | } |
173 | ||
52686203 EB |
174 | static int em_parse_call(struct nlmsghdr *n, struct tcf_ematch_hdr *hdr, |
175 | struct ematch_util *e, struct ematch *t) | |
176 | { | |
177 | if (e->parse_eopt_argv) { | |
178 | int argc = 0, i = 0, ret; | |
179 | struct bstr *args; | |
180 | char **argv; | |
181 | ||
182 | for (args = t->args; args; args = bstr_next(args)) | |
183 | argc++; | |
184 | argv = calloc(argc, sizeof(char *)); | |
185 | if (!argv) | |
186 | return -1; | |
187 | for (args = t->args; args; args = bstr_next(args)) | |
188 | argv[i++] = args->data; | |
189 | ||
190 | ret = e->parse_eopt_argv(n, hdr, argc, argv); | |
191 | ||
192 | free(argv); | |
193 | return ret; | |
194 | } | |
195 | ||
196 | return e->parse_eopt(n, hdr, t->args->next); | |
197 | } | |
198 | ||
7a473c77 SH |
199 | static int parse_tree(struct nlmsghdr *n, struct ematch *tree) |
200 | { | |
201 | int index = 1; | |
202 | struct ematch *t; | |
203 | ||
204 | for (t = tree; t; t = t->next) { | |
c14f9d92 | 205 | struct rtattr *tail; |
d17b136f | 206 | struct tcf_ematch_hdr hdr = { .flags = t->relation }; |
7a473c77 SH |
207 | |
208 | if (t->inverted) | |
209 | hdr.flags |= TCF_EM_INVERT; | |
ae665a52 | 210 | |
c14f9d92 | 211 | tail = addattr_nest(n, MAX_MSG, index++); |
7a473c77 SH |
212 | |
213 | if (t->child) { | |
214 | __u32 r = t->child_ref; | |
32a121cb | 215 | |
7a473c77 SH |
216 | addraw_l(n, MAX_MSG, &hdr, sizeof(hdr)); |
217 | addraw_l(n, MAX_MSG, &r, sizeof(r)); | |
218 | } else { | |
3fcdebb6 | 219 | int num = 0, err; |
7a473c77 SH |
220 | char buf[64]; |
221 | struct ematch_util *e; | |
222 | ||
223 | if (t->args == NULL) | |
224 | return -1; | |
225 | ||
32a121cb | 226 | strncpy(buf, (char *) t->args->data, sizeof(buf)-1); |
7a473c77 SH |
227 | e = get_ematch_kind(buf); |
228 | if (e == NULL) { | |
229 | fprintf(stderr, "Unknown ematch \"%s\"\n", | |
230 | buf); | |
231 | return -1; | |
232 | } | |
233 | ||
234 | err = lookup_map_id(buf, &num, EMATCH_MAP); | |
235 | if (err < 0) { | |
236 | if (err == -ENOENT) | |
237 | map_warning(e->kind_num, buf); | |
238 | return err; | |
239 | } | |
240 | ||
241 | hdr.kind = num; | |
52686203 | 242 | if (em_parse_call(n, &hdr, e, t) < 0) |
7a473c77 SH |
243 | return -1; |
244 | } | |
245 | ||
c14f9d92 | 246 | addattr_nest_end(n, tail); |
7a473c77 SH |
247 | } |
248 | ||
249 | return 0; | |
250 | } | |
251 | ||
252 | static int flatten_tree(struct ematch *head, struct ematch *tree) | |
253 | { | |
254 | int i, count = 0; | |
255 | struct ematch *t; | |
256 | ||
257 | for (;;) { | |
258 | count++; | |
259 | ||
260 | if (tree->child) { | |
261 | for (t = head; t->next; t = t->next); | |
262 | t->next = tree->child; | |
263 | count += flatten_tree(head, tree->child); | |
264 | } | |
265 | ||
266 | if (tree->relation == 0) | |
267 | break; | |
268 | ||
269 | tree = tree->next; | |
270 | } | |
271 | ||
272 | for (i = 0, t = head; t; t = t->next, i++) | |
273 | t->index = i; | |
274 | ||
275 | for (t = head; t; t = t->next) | |
276 | if (t->child) | |
277 | t->child_ref = t->child->index; | |
278 | ||
279 | return count; | |
280 | } | |
281 | ||
5d5586b0 | 282 | __attribute__((format(printf, 5, 6))) |
7a473c77 SH |
283 | int em_parse_error(int err, struct bstr *args, struct bstr *carg, |
284 | struct ematch_util *e, char *fmt, ...) | |
285 | { | |
286 | va_list a; | |
287 | ||
288 | va_start(a, fmt); | |
289 | vfprintf(stderr, fmt, a); | |
290 | va_end(a); | |
291 | ||
292 | if (ematch_err) | |
293 | fprintf(stderr, ": %s\n... ", ematch_err); | |
294 | else | |
295 | fprintf(stderr, "\n... "); | |
296 | ||
297 | while (ematch_argc < begin_argc) { | |
298 | if (ematch_argc == (begin_argc - 1)) | |
299 | fprintf(stderr, ">>%s<< ", *begin_argv); | |
300 | else | |
301 | fprintf(stderr, "%s ", *begin_argv); | |
302 | begin_argv++; | |
303 | begin_argc--; | |
304 | } | |
ae665a52 | 305 | |
7a473c77 SH |
306 | fprintf(stderr, "...\n"); |
307 | ||
308 | if (args) { | |
309 | fprintf(stderr, "... %s(", e->kind); | |
310 | while (args) { | |
311 | fprintf(stderr, "%s", args == carg ? ">>" : ""); | |
312 | bstr_print(stderr, args, 1); | |
313 | fprintf(stderr, "%s%s", args == carg ? "<<" : "", | |
314 | args->next ? " " : ""); | |
315 | args = args->next; | |
316 | } | |
317 | fprintf(stderr, ")...\n"); | |
318 | ||
319 | } | |
320 | ||
321 | if (e == NULL) { | |
322 | fprintf(stderr, | |
323 | "Usage: EXPR\n" \ | |
324 | "where: EXPR := TERM [ { and | or } EXPR ]\n" \ | |
325 | " TERM := [ not ] { MATCH | '(' EXPR ')' }\n" \ | |
326 | " MATCH := module '(' ARGS ')'\n" \ | |
327 | " ARGS := ARG1 ARG2 ...\n" \ | |
328 | "\n" \ | |
329 | "Example: a(x y) and not (b(x) or c(x y z))\n"); | |
330 | } else | |
331 | e->print_usage(stderr); | |
332 | ||
333 | return -err; | |
334 | } | |
335 | ||
336 | static inline void free_ematch_err(void) | |
337 | { | |
338 | if (ematch_err) { | |
339 | free(ematch_err); | |
340 | ematch_err = NULL; | |
341 | } | |
342 | } | |
343 | ||
344 | extern int ematch_parse(void); | |
345 | ||
346 | int parse_ematch(int *argc_p, char ***argv_p, int tca_id, struct nlmsghdr *n) | |
347 | { | |
348 | begin_argc = ematch_argc = *argc_p; | |
349 | begin_argv = ematch_argv = *argv_p; | |
350 | ||
351 | if (ematch_parse()) { | |
352 | int err = em_parse_error(EINVAL, NULL, NULL, NULL, | |
353 | "Parse error"); | |
354 | free_ematch_err(); | |
355 | return err; | |
356 | } | |
357 | ||
358 | free_ematch_err(); | |
359 | ||
360 | /* undo look ahead by parser */ | |
361 | ematch_argc++; | |
362 | ematch_argv--; | |
363 | ||
364 | if (ematch_root) { | |
365 | struct rtattr *tail, *tail_list; | |
366 | ||
367 | struct tcf_ematch_tree_hdr hdr = { | |
368 | .nmatches = flatten_tree(ematch_root, ematch_root), | |
369 | .progid = TCF_EM_PROG_TC | |
370 | }; | |
371 | ||
c14f9d92 | 372 | tail = addattr_nest(n, MAX_MSG, tca_id); |
7a473c77 SH |
373 | addattr_l(n, MAX_MSG, TCA_EMATCH_TREE_HDR, &hdr, sizeof(hdr)); |
374 | ||
c14f9d92 | 375 | tail_list = addattr_nest(n, MAX_MSG, TCA_EMATCH_TREE_LIST); |
7a473c77 SH |
376 | |
377 | if (parse_tree(n, ematch_root) < 0) | |
378 | return -1; | |
379 | ||
c14f9d92 SP |
380 | addattr_nest_end(n, tail_list); |
381 | addattr_nest_end(n, tail); | |
7a473c77 SH |
382 | } |
383 | ||
384 | *argc_p = ematch_argc; | |
385 | *argv_p = ematch_argv; | |
386 | ||
387 | return 0; | |
388 | } | |
389 | ||
390 | static int print_ematch_seq(FILE *fd, struct rtattr **tb, int start, | |
391 | int prefix) | |
392 | { | |
393 | int n, i = start; | |
394 | struct tcf_ematch_hdr *hdr; | |
395 | int dlen; | |
396 | void *data; | |
397 | ||
398 | for (;;) { | |
399 | if (tb[i] == NULL) | |
400 | return -1; | |
401 | ||
402 | dlen = RTA_PAYLOAD(tb[i]) - sizeof(*hdr); | |
403 | data = (void *) RTA_DATA(tb[i]) + sizeof(*hdr); | |
404 | ||
405 | if (dlen < 0) | |
406 | return -1; | |
407 | ||
408 | hdr = RTA_DATA(tb[i]); | |
409 | ||
410 | if (hdr->flags & TCF_EM_INVERT) | |
411 | fprintf(fd, "NOT "); | |
412 | ||
413 | if (hdr->kind == 0) { | |
414 | __u32 ref; | |
415 | ||
416 | if (dlen < sizeof(__u32)) | |
417 | return -1; | |
418 | ||
419 | ref = *(__u32 *) data; | |
420 | fprintf(fd, "(\n"); | |
421 | for (n = 0; n <= prefix; n++) | |
422 | fprintf(fd, " "); | |
423 | if (print_ematch_seq(fd, tb, ref + 1, prefix + 1) < 0) | |
424 | return -1; | |
425 | for (n = 0; n < prefix; n++) | |
426 | fprintf(fd, " "); | |
427 | fprintf(fd, ") "); | |
428 | ||
429 | } else { | |
430 | struct ematch_util *e; | |
431 | ||
432 | e = get_ematch_kind_num(hdr->kind); | |
433 | if (e == NULL) | |
434 | fprintf(fd, "[unknown ematch %d]\n", | |
435 | hdr->kind); | |
436 | else { | |
437 | fprintf(fd, "%s(", e->kind); | |
438 | if (e->print_eopt(fd, hdr, data, dlen) < 0) | |
439 | return -1; | |
440 | fprintf(fd, ")\n"); | |
441 | } | |
442 | if (hdr->flags & TCF_EM_REL_MASK) | |
443 | for (n = 0; n < prefix; n++) | |
444 | fprintf(fd, " "); | |
445 | } | |
446 | ||
447 | switch (hdr->flags & TCF_EM_REL_MASK) { | |
448 | case TCF_EM_REL_AND: | |
449 | fprintf(fd, "AND "); | |
450 | break; | |
451 | ||
452 | case TCF_EM_REL_OR: | |
453 | fprintf(fd, "OR "); | |
454 | break; | |
455 | ||
456 | default: | |
457 | return 0; | |
458 | } | |
459 | ||
460 | i++; | |
461 | } | |
ae665a52 | 462 | |
7a473c77 SH |
463 | return 0; |
464 | } | |
465 | ||
466 | static int print_ematch_list(FILE *fd, struct tcf_ematch_tree_hdr *hdr, | |
467 | struct rtattr *rta) | |
468 | { | |
469 | int err = -1; | |
470 | struct rtattr **tb; | |
471 | ||
472 | tb = malloc((hdr->nmatches + 1) * sizeof(struct rtattr *)); | |
473 | if (tb == NULL) | |
474 | return -1; | |
475 | ||
4b45abd1 SH |
476 | if (hdr->nmatches > 0) { |
477 | if (parse_rtattr_nested(tb, hdr->nmatches, rta) < 0) | |
478 | goto errout; | |
7a473c77 | 479 | |
4b45abd1 SH |
480 | fprintf(fd, "\n "); |
481 | if (print_ematch_seq(fd, tb, 1, 1) < 0) | |
482 | goto errout; | |
483 | } | |
7a473c77 SH |
484 | |
485 | err = 0; | |
486 | errout: | |
487 | free(tb); | |
488 | return err; | |
489 | } | |
490 | ||
491 | int print_ematch(FILE *fd, const struct rtattr *rta) | |
492 | { | |
493 | struct rtattr *tb[TCA_EMATCH_TREE_MAX+1]; | |
494 | struct tcf_ematch_tree_hdr *hdr; | |
495 | ||
496 | if (parse_rtattr_nested(tb, TCA_EMATCH_TREE_MAX, rta) < 0) | |
497 | return -1; | |
498 | ||
499 | if (tb[TCA_EMATCH_TREE_HDR] == NULL) { | |
500 | fprintf(stderr, "Missing ematch tree header\n"); | |
501 | return -1; | |
502 | } | |
503 | ||
504 | if (tb[TCA_EMATCH_TREE_LIST] == NULL) { | |
505 | fprintf(stderr, "Missing ematch tree list\n"); | |
506 | return -1; | |
507 | } | |
508 | ||
509 | if (RTA_PAYLOAD(tb[TCA_EMATCH_TREE_HDR]) < sizeof(*hdr)) { | |
510 | fprintf(stderr, "Ematch tree header size mismatch\n"); | |
511 | return -1; | |
512 | } | |
513 | ||
514 | hdr = RTA_DATA(tb[TCA_EMATCH_TREE_HDR]); | |
515 | ||
516 | return print_ematch_list(fd, hdr, tb[TCA_EMATCH_TREE_LIST]); | |
517 | } | |
b6da1afc | 518 | |
32a121cb | 519 | struct bstr *bstr_alloc(const char *text) |
b6da1afc SH |
520 | { |
521 | struct bstr *b = calloc(1, sizeof(*b)); | |
522 | ||
523 | if (b == NULL) | |
524 | return NULL; | |
525 | ||
526 | b->data = strdup(text); | |
527 | if (b->data == NULL) { | |
528 | free(b); | |
529 | return NULL; | |
530 | } | |
531 | ||
532 | b->len = strlen(text); | |
533 | ||
534 | return b; | |
535 | } | |
536 | ||
537 | unsigned long bstrtoul(const struct bstr *b) | |
538 | { | |
539 | char *inv = NULL; | |
540 | unsigned long l; | |
541 | char buf[b->len+1]; | |
542 | ||
543 | memcpy(buf, b->data, b->len); | |
544 | buf[b->len] = '\0'; | |
545 | ||
546 | l = strtoul(buf, &inv, 0); | |
547 | if (l == ULONG_MAX || inv == buf) | |
548 | return ULONG_MAX; | |
549 | ||
550 | return l; | |
551 | } | |
552 | ||
33043dfc | 553 | static void bstr_print(FILE *fd, const struct bstr *b, int ascii) |
b6da1afc SH |
554 | { |
555 | int i; | |
556 | char *s = b->data; | |
557 | ||
558 | if (ascii) | |
559 | for (i = 0; i < b->len; i++) | |
560 | fprintf(fd, "%c", isprint(s[i]) ? s[i] : '.'); | |
561 | else { | |
562 | for (i = 0; i < b->len; i++) | |
563 | fprintf(fd, "%02x", s[i]); | |
564 | fprintf(fd, "\""); | |
565 | for (i = 0; i < b->len; i++) | |
566 | fprintf(fd, "%c", isprint(s[i]) ? s[i] : '.'); | |
567 | fprintf(fd, "\""); | |
568 | } | |
569 | } |