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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> | |
15 | #include <syslog.h> | |
16 | #include <fcntl.h> | |
17 | #include <sys/socket.h> | |
18 | #include <netinet/in.h> | |
19 | #include <arpa/inet.h> | |
20 | #include <string.h> | |
21 | #include <dlfcn.h> | |
22 | #include <stdarg.h> | |
23 | #include <errno.h> | |
24 | ||
25 | #include "utils.h" | |
26 | #include "tc_util.h" | |
27 | #include "m_ematch.h" | |
28 | ||
29 | #define EMATCH_MAP "/etc/iproute2/ematch_map" | |
30 | ||
31 | static struct ematch_util *ematch_list; | |
32 | ||
33 | /* export to bison parser */ | |
34 | int ematch_argc; | |
35 | char **ematch_argv; | |
36 | char *ematch_err = NULL; | |
37 | struct ematch *ematch_root; | |
38 | ||
39 | static int begin_argc; | |
40 | static char **begin_argv; | |
41 | ||
42 | static inline void map_warning(int num, char *kind) | |
43 | { | |
44 | fprintf(stderr, | |
45 | "Error: Unable to find ematch \"%s\" in %s\n" \ | |
46 | "Please assign a unique ID to the ematch kind the suggested " \ | |
47 | "entry is:\n" \ | |
ae665a52 | 48 | "\t%d\t%s\n", |
7a473c77 SH |
49 | kind, EMATCH_MAP, num, kind); |
50 | } | |
51 | ||
52 | static int lookup_map(__u16 num, char *dst, int len, const char *file) | |
53 | { | |
54 | int err = -EINVAL; | |
55 | char buf[512]; | |
56 | FILE *fd = fopen(file, "r"); | |
57 | ||
58 | if (fd == NULL) | |
59 | return -errno; | |
60 | ||
61 | while (fgets(buf, sizeof(buf), fd)) { | |
62 | char namebuf[512], *p = buf; | |
63 | int id; | |
64 | ||
65 | while (*p == ' ' || *p == '\t') | |
66 | p++; | |
67 | if (*p == '#' || *p == '\n' || *p == 0) | |
68 | continue; | |
ae665a52 | 69 | |
7a473c77 SH |
70 | if (sscanf(p, "%d %s", &id, namebuf) != 2) { |
71 | fprintf(stderr, "ematch map %s corrupted at %s\n", | |
72 | file, p); | |
73 | goto out; | |
74 | } | |
75 | ||
76 | if (id == num) { | |
77 | if (dst) | |
78 | strncpy(dst, namebuf, len - 1); | |
79 | err = 0; | |
80 | goto out; | |
81 | } | |
82 | } | |
83 | ||
84 | err = -ENOENT; | |
85 | out: | |
86 | fclose(fd); | |
87 | return err; | |
88 | } | |
89 | ||
90 | static int lookup_map_id(char *kind, int *dst, const char *file) | |
91 | { | |
92 | int err = -EINVAL; | |
93 | char buf[512]; | |
94 | FILE *fd = fopen(file, "r"); | |
95 | ||
96 | if (fd == NULL) | |
97 | return -errno; | |
98 | ||
99 | while (fgets(buf, sizeof(buf), fd)) { | |
100 | char namebuf[512], *p = buf; | |
101 | int id; | |
102 | ||
103 | while (*p == ' ' || *p == '\t') | |
104 | p++; | |
105 | if (*p == '#' || *p == '\n' || *p == 0) | |
106 | continue; | |
ae665a52 | 107 | |
7a473c77 SH |
108 | if (sscanf(p, "%d %s", &id, namebuf) != 2) { |
109 | fprintf(stderr, "ematch map %s corrupted at %s\n", | |
110 | file, p); | |
111 | goto out; | |
112 | } | |
113 | ||
114 | if (!strcasecmp(namebuf, kind)) { | |
115 | if (dst) | |
116 | *dst = id; | |
117 | err = 0; | |
118 | goto out; | |
119 | } | |
120 | } | |
121 | ||
122 | err = -ENOENT; | |
f332d169 | 123 | *dst = 0; |
7a473c77 SH |
124 | out: |
125 | fclose(fd); | |
126 | return err; | |
127 | } | |
128 | ||
129 | static struct ematch_util *get_ematch_kind(char *kind) | |
130 | { | |
131 | static void *body; | |
132 | void *dlh; | |
133 | char buf[256]; | |
134 | struct ematch_util *e; | |
135 | ||
136 | for (e = ematch_list; e; e = e->next) { | |
137 | if (strcmp(e->kind, kind) == 0) | |
138 | return e; | |
139 | } | |
140 | ||
141 | snprintf(buf, sizeof(buf), "em_%s.so", kind); | |
142 | dlh = dlopen(buf, RTLD_LAZY); | |
143 | if (dlh == NULL) { | |
144 | dlh = body; | |
145 | if (dlh == NULL) { | |
146 | dlh = body = dlopen(NULL, RTLD_LAZY); | |
147 | if (dlh == NULL) | |
148 | return NULL; | |
149 | } | |
150 | } | |
151 | ||
152 | snprintf(buf, sizeof(buf), "%s_ematch_util", kind); | |
153 | e = dlsym(dlh, buf); | |
154 | if (e == NULL) | |
155 | return NULL; | |
156 | ||
157 | e->next = ematch_list; | |
158 | ematch_list = e; | |
159 | ||
160 | return e; | |
161 | } | |
162 | ||
163 | static struct ematch_util *get_ematch_kind_num(__u16 kind) | |
164 | { | |
165 | char name[32]; | |
166 | ||
167 | if (lookup_map(kind, name, sizeof(name), EMATCH_MAP) < 0) | |
168 | return NULL; | |
169 | ||
170 | return get_ematch_kind(name); | |
171 | ||
172 | return NULL; | |
173 | } | |
174 | ||
175 | static int parse_tree(struct nlmsghdr *n, struct ematch *tree) | |
176 | { | |
177 | int index = 1; | |
178 | struct ematch *t; | |
179 | ||
180 | for (t = tree; t; t = t->next) { | |
181 | struct rtattr *tail = NLMSG_TAIL(n); | |
182 | struct tcf_ematch_hdr hdr = { | |
183 | .flags = t->relation | |
184 | }; | |
185 | ||
186 | if (t->inverted) | |
187 | hdr.flags |= TCF_EM_INVERT; | |
ae665a52 | 188 | |
7a473c77 SH |
189 | addattr_l(n, MAX_MSG, index++, NULL, 0); |
190 | ||
191 | if (t->child) { | |
192 | __u32 r = t->child_ref; | |
193 | addraw_l(n, MAX_MSG, &hdr, sizeof(hdr)); | |
194 | addraw_l(n, MAX_MSG, &r, sizeof(r)); | |
195 | } else { | |
3fcdebb6 | 196 | int num = 0, err; |
7a473c77 SH |
197 | char buf[64]; |
198 | struct ematch_util *e; | |
199 | ||
200 | if (t->args == NULL) | |
201 | return -1; | |
202 | ||
203 | strncpy(buf, (char*) t->args->data, sizeof(buf)-1); | |
204 | e = get_ematch_kind(buf); | |
205 | if (e == NULL) { | |
206 | fprintf(stderr, "Unknown ematch \"%s\"\n", | |
207 | buf); | |
208 | return -1; | |
209 | } | |
210 | ||
211 | err = lookup_map_id(buf, &num, EMATCH_MAP); | |
212 | if (err < 0) { | |
213 | if (err == -ENOENT) | |
214 | map_warning(e->kind_num, buf); | |
215 | return err; | |
216 | } | |
217 | ||
218 | hdr.kind = num; | |
219 | if (e->parse_eopt(n, &hdr, t->args->next) < 0) | |
220 | return -1; | |
221 | } | |
222 | ||
223 | tail->rta_len = (void*) NLMSG_TAIL(n) - (void*) tail; | |
224 | } | |
225 | ||
226 | return 0; | |
227 | } | |
228 | ||
229 | static int flatten_tree(struct ematch *head, struct ematch *tree) | |
230 | { | |
231 | int i, count = 0; | |
232 | struct ematch *t; | |
233 | ||
234 | for (;;) { | |
235 | count++; | |
236 | ||
237 | if (tree->child) { | |
238 | for (t = head; t->next; t = t->next); | |
239 | t->next = tree->child; | |
240 | count += flatten_tree(head, tree->child); | |
241 | } | |
242 | ||
243 | if (tree->relation == 0) | |
244 | break; | |
245 | ||
246 | tree = tree->next; | |
247 | } | |
248 | ||
249 | for (i = 0, t = head; t; t = t->next, i++) | |
250 | t->index = i; | |
251 | ||
252 | for (t = head; t; t = t->next) | |
253 | if (t->child) | |
254 | t->child_ref = t->child->index; | |
255 | ||
256 | return count; | |
257 | } | |
258 | ||
259 | int em_parse_error(int err, struct bstr *args, struct bstr *carg, | |
260 | struct ematch_util *e, char *fmt, ...) | |
261 | { | |
262 | va_list a; | |
263 | ||
264 | va_start(a, fmt); | |
265 | vfprintf(stderr, fmt, a); | |
266 | va_end(a); | |
267 | ||
268 | if (ematch_err) | |
269 | fprintf(stderr, ": %s\n... ", ematch_err); | |
270 | else | |
271 | fprintf(stderr, "\n... "); | |
272 | ||
273 | while (ematch_argc < begin_argc) { | |
274 | if (ematch_argc == (begin_argc - 1)) | |
275 | fprintf(stderr, ">>%s<< ", *begin_argv); | |
276 | else | |
277 | fprintf(stderr, "%s ", *begin_argv); | |
278 | begin_argv++; | |
279 | begin_argc--; | |
280 | } | |
ae665a52 | 281 | |
7a473c77 SH |
282 | fprintf(stderr, "...\n"); |
283 | ||
284 | if (args) { | |
285 | fprintf(stderr, "... %s(", e->kind); | |
286 | while (args) { | |
287 | fprintf(stderr, "%s", args == carg ? ">>" : ""); | |
288 | bstr_print(stderr, args, 1); | |
289 | fprintf(stderr, "%s%s", args == carg ? "<<" : "", | |
290 | args->next ? " " : ""); | |
291 | args = args->next; | |
292 | } | |
293 | fprintf(stderr, ")...\n"); | |
294 | ||
295 | } | |
296 | ||
297 | if (e == NULL) { | |
298 | fprintf(stderr, | |
299 | "Usage: EXPR\n" \ | |
300 | "where: EXPR := TERM [ { and | or } EXPR ]\n" \ | |
301 | " TERM := [ not ] { MATCH | '(' EXPR ')' }\n" \ | |
302 | " MATCH := module '(' ARGS ')'\n" \ | |
303 | " ARGS := ARG1 ARG2 ...\n" \ | |
304 | "\n" \ | |
305 | "Example: a(x y) and not (b(x) or c(x y z))\n"); | |
306 | } else | |
307 | e->print_usage(stderr); | |
308 | ||
309 | return -err; | |
310 | } | |
311 | ||
312 | static inline void free_ematch_err(void) | |
313 | { | |
314 | if (ematch_err) { | |
315 | free(ematch_err); | |
316 | ematch_err = NULL; | |
317 | } | |
318 | } | |
319 | ||
320 | extern int ematch_parse(void); | |
321 | ||
322 | int parse_ematch(int *argc_p, char ***argv_p, int tca_id, struct nlmsghdr *n) | |
323 | { | |
324 | begin_argc = ematch_argc = *argc_p; | |
325 | begin_argv = ematch_argv = *argv_p; | |
326 | ||
327 | if (ematch_parse()) { | |
328 | int err = em_parse_error(EINVAL, NULL, NULL, NULL, | |
329 | "Parse error"); | |
330 | free_ematch_err(); | |
331 | return err; | |
332 | } | |
333 | ||
334 | free_ematch_err(); | |
335 | ||
336 | /* undo look ahead by parser */ | |
337 | ematch_argc++; | |
338 | ematch_argv--; | |
339 | ||
340 | if (ematch_root) { | |
341 | struct rtattr *tail, *tail_list; | |
342 | ||
343 | struct tcf_ematch_tree_hdr hdr = { | |
344 | .nmatches = flatten_tree(ematch_root, ematch_root), | |
345 | .progid = TCF_EM_PROG_TC | |
346 | }; | |
347 | ||
348 | tail = NLMSG_TAIL(n); | |
349 | addattr_l(n, MAX_MSG, tca_id, NULL, 0); | |
350 | addattr_l(n, MAX_MSG, TCA_EMATCH_TREE_HDR, &hdr, sizeof(hdr)); | |
351 | ||
352 | tail_list = NLMSG_TAIL(n); | |
353 | addattr_l(n, MAX_MSG, TCA_EMATCH_TREE_LIST, NULL, 0); | |
354 | ||
355 | if (parse_tree(n, ematch_root) < 0) | |
356 | return -1; | |
357 | ||
358 | tail_list->rta_len = (void*) NLMSG_TAIL(n) - (void*) tail_list; | |
359 | tail->rta_len = (void*) NLMSG_TAIL(n) - (void*) tail; | |
360 | } | |
361 | ||
362 | *argc_p = ematch_argc; | |
363 | *argv_p = ematch_argv; | |
364 | ||
365 | return 0; | |
366 | } | |
367 | ||
368 | static int print_ematch_seq(FILE *fd, struct rtattr **tb, int start, | |
369 | int prefix) | |
370 | { | |
371 | int n, i = start; | |
372 | struct tcf_ematch_hdr *hdr; | |
373 | int dlen; | |
374 | void *data; | |
375 | ||
376 | for (;;) { | |
377 | if (tb[i] == NULL) | |
378 | return -1; | |
379 | ||
380 | dlen = RTA_PAYLOAD(tb[i]) - sizeof(*hdr); | |
381 | data = (void *) RTA_DATA(tb[i]) + sizeof(*hdr); | |
382 | ||
383 | if (dlen < 0) | |
384 | return -1; | |
385 | ||
386 | hdr = RTA_DATA(tb[i]); | |
387 | ||
388 | if (hdr->flags & TCF_EM_INVERT) | |
389 | fprintf(fd, "NOT "); | |
390 | ||
391 | if (hdr->kind == 0) { | |
392 | __u32 ref; | |
393 | ||
394 | if (dlen < sizeof(__u32)) | |
395 | return -1; | |
396 | ||
397 | ref = *(__u32 *) data; | |
398 | fprintf(fd, "(\n"); | |
399 | for (n = 0; n <= prefix; n++) | |
400 | fprintf(fd, " "); | |
401 | if (print_ematch_seq(fd, tb, ref + 1, prefix + 1) < 0) | |
402 | return -1; | |
403 | for (n = 0; n < prefix; n++) | |
404 | fprintf(fd, " "); | |
405 | fprintf(fd, ") "); | |
406 | ||
407 | } else { | |
408 | struct ematch_util *e; | |
409 | ||
410 | e = get_ematch_kind_num(hdr->kind); | |
411 | if (e == NULL) | |
412 | fprintf(fd, "[unknown ematch %d]\n", | |
413 | hdr->kind); | |
414 | else { | |
415 | fprintf(fd, "%s(", e->kind); | |
416 | if (e->print_eopt(fd, hdr, data, dlen) < 0) | |
417 | return -1; | |
418 | fprintf(fd, ")\n"); | |
419 | } | |
420 | if (hdr->flags & TCF_EM_REL_MASK) | |
421 | for (n = 0; n < prefix; n++) | |
422 | fprintf(fd, " "); | |
423 | } | |
424 | ||
425 | switch (hdr->flags & TCF_EM_REL_MASK) { | |
426 | case TCF_EM_REL_AND: | |
427 | fprintf(fd, "AND "); | |
428 | break; | |
429 | ||
430 | case TCF_EM_REL_OR: | |
431 | fprintf(fd, "OR "); | |
432 | break; | |
433 | ||
434 | default: | |
435 | return 0; | |
436 | } | |
437 | ||
438 | i++; | |
439 | } | |
ae665a52 | 440 | |
7a473c77 SH |
441 | return 0; |
442 | } | |
443 | ||
444 | static int print_ematch_list(FILE *fd, struct tcf_ematch_tree_hdr *hdr, | |
445 | struct rtattr *rta) | |
446 | { | |
447 | int err = -1; | |
448 | struct rtattr **tb; | |
449 | ||
450 | tb = malloc((hdr->nmatches + 1) * sizeof(struct rtattr *)); | |
451 | if (tb == NULL) | |
452 | return -1; | |
453 | ||
454 | if (parse_rtattr_nested(tb, hdr->nmatches, rta) < 0) | |
455 | goto errout; | |
456 | ||
457 | fprintf(fd, "\n "); | |
458 | if (print_ematch_seq(fd, tb, 1, 1) < 0) | |
459 | goto errout; | |
460 | ||
461 | err = 0; | |
462 | errout: | |
463 | free(tb); | |
464 | return err; | |
465 | } | |
466 | ||
467 | int print_ematch(FILE *fd, const struct rtattr *rta) | |
468 | { | |
469 | struct rtattr *tb[TCA_EMATCH_TREE_MAX+1]; | |
470 | struct tcf_ematch_tree_hdr *hdr; | |
471 | ||
472 | if (parse_rtattr_nested(tb, TCA_EMATCH_TREE_MAX, rta) < 0) | |
473 | return -1; | |
474 | ||
475 | if (tb[TCA_EMATCH_TREE_HDR] == NULL) { | |
476 | fprintf(stderr, "Missing ematch tree header\n"); | |
477 | return -1; | |
478 | } | |
479 | ||
480 | if (tb[TCA_EMATCH_TREE_LIST] == NULL) { | |
481 | fprintf(stderr, "Missing ematch tree list\n"); | |
482 | return -1; | |
483 | } | |
484 | ||
485 | if (RTA_PAYLOAD(tb[TCA_EMATCH_TREE_HDR]) < sizeof(*hdr)) { | |
486 | fprintf(stderr, "Ematch tree header size mismatch\n"); | |
487 | return -1; | |
488 | } | |
489 | ||
490 | hdr = RTA_DATA(tb[TCA_EMATCH_TREE_HDR]); | |
491 | ||
492 | return print_ematch_list(fd, hdr, tb[TCA_EMATCH_TREE_LIST]); | |
493 | } |