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1 /*
2  * m_action.c		Action Management
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:  J Hadi Salim (hadi@cyberus.ca)
10  *
11  * TODO:
12  * - parse to be passed a filedescriptor for logging purposes
13  *
14 */
15 
16 #include <stdio.h>
17 #include <stdlib.h>
18 #include <unistd.h>
19 #include <syslog.h>
20 #include <fcntl.h>
21 #include <sys/socket.h>
22 #include <netinet/in.h>
23 #include <arpa/inet.h>
24 #include <string.h>
25 #include <dlfcn.h>
26 
27 #include "utils.h"
28 #include "tc_common.h"
29 #include "tc_util.h"
30 
31 static struct action_util * action_list;
32 
33 #ifdef ANDROID
34 extern struct action_util mirred_action_util;
35 #endif
36 
37 #ifdef CONFIG_GACT
38 int gact_ld = 0 ; //fuckin backward compatibility
39 #endif
40 int batch_c = 0;
41 int tab_flush = 0;
42 
act_usage(void)43 void act_usage(void)
44 {
45 	/*XXX: In the near future add a action->print_help to improve
46 	 * usability
47 	 * This would mean new tc will not be backward compatible
48 	 * with any action .so from the old days. But if someone really
49 	 * does that, they would know how to fix this ..
50 	 *
51 	*/
52 	fprintf (stderr, "usage: tc actions <ACTSPECOP>*\n");
53 	fprintf(stderr,
54 		"Where: \tACTSPECOP := ACR | GD | FL\n"
55 			"\tACR := add | change | replace <ACTSPEC>* \n"
56 			"\tGD := get | delete | <ACTISPEC>*\n"
57 			"\tFL := ls | list | flush | <ACTNAMESPEC>\n"
58 			"\tACTNAMESPEC :=  action <ACTNAME>\n"
59 			"\tACTISPEC := <ACTNAMESPEC> <INDEXSPEC>\n"
60 			"\tACTSPEC := action <ACTDETAIL> [INDEXSPEC]\n"
61 			"\tINDEXSPEC := index <32 bit indexvalue>\n"
62 			"\tACTDETAIL := <ACTNAME> <ACTPARAMS>\n"
63 			"\t\tExample ACTNAME is gact, mirred etc\n"
64 			"\t\tEach action has its own parameters (ACTPARAMS)\n"
65 			"\n");
66 
67 	exit(-1);
68 }
69 
print_noaopt(struct action_util * au,FILE * f,struct rtattr * opt)70 static int print_noaopt(struct action_util *au, FILE *f, struct rtattr *opt)
71 {
72 	if (opt && RTA_PAYLOAD(opt))
73 		fprintf(f, "[Unknown action, optlen=%u] ",
74 			(unsigned) RTA_PAYLOAD(opt));
75 	return 0;
76 }
77 
parse_noaopt(struct action_util * au,int * argc_p,char *** argv_p,int code,struct nlmsghdr * n)78 static int parse_noaopt(struct action_util *au, int *argc_p, char ***argv_p, int code, struct nlmsghdr *n)
79 {
80 	int argc = *argc_p;
81 	char **argv = *argv_p;
82 
83 	if (argc) {
84 		fprintf(stderr, "Unknown action \"%s\", hence option \"%s\" is unparsable\n", au->id, *argv);
85 	} else {
86 		fprintf(stderr, "Unknown action \"%s\"\n", au->id);
87 	}
88 	return -1;
89 }
90 
get_action_kind(char * str)91 struct action_util *get_action_kind(char *str)
92 {
93 #ifdef ANDROID
94 	if (!strcmp(str, "mirred")) {
95 		return &mirred_action_util;
96 	} else {
97 		fprintf(stderr, "Android does not support action '%s'", str);
98 		return NULL;
99 	}
100 #endif
101 	static void *aBODY;
102 	void *dlh;
103 	char buf[256];
104 	struct action_util *a;
105 #ifdef CONFIG_GACT
106 	int looked4gact = 0;
107 restart_s:
108 #endif
109 	for (a = action_list; a; a = a->next) {
110 		if (strcmp(a->id, str) == 0)
111 			return a;
112 	}
113 
114 	snprintf(buf, sizeof(buf), "m_%s.so", str);
115 	dlh = dlopen(buf, RTLD_LAZY);
116 	if (dlh == NULL) {
117 		dlh = aBODY;
118 		if (dlh == NULL) {
119 			dlh = aBODY = dlopen(NULL, RTLD_LAZY);
120 			if (dlh == NULL)
121 				goto noexist;
122 		}
123 	}
124 
125 	snprintf(buf, sizeof(buf), "%s_action_util", str);
126 	a = dlsym(dlh, buf);
127 	if (a == NULL)
128 		goto noexist;
129 
130 reg:
131 	a->next = action_list;
132 	action_list = a;
133 	return a;
134 
135 noexist:
136 #ifdef CONFIG_GACT
137 	if (!looked4gact) {
138 		looked4gact = 1;
139 		strcpy(str,"gact");
140 		goto restart_s;
141 	}
142 #endif
143 	a = malloc(sizeof(*a));
144 	if (a) {
145 		memset(a, 0, sizeof(*a));
146 		strncpy(a->id, "noact", 15);
147 		a->parse_aopt = parse_noaopt;
148 		a->print_aopt = print_noaopt;
149 		goto reg;
150 	}
151 	return a;
152 }
153 
154 int
new_cmd(char ** argv)155 new_cmd(char **argv)
156 {
157 	if ((matches(*argv, "change") == 0) ||
158 		(matches(*argv, "replace") == 0)||
159 		(matches(*argv, "delete") == 0)||
160 		(matches(*argv, "add") == 0))
161 			return 1;
162 
163 	return 0;
164 
165 }
166 
167 int
parse_action(int * argc_p,char *** argv_p,int tca_id,struct nlmsghdr * n)168 parse_action(int *argc_p, char ***argv_p, int tca_id, struct nlmsghdr *n)
169 {
170 	int argc = *argc_p;
171 	char **argv = *argv_p;
172 	struct rtattr *tail, *tail2;
173 	char k[16];
174 	int ok = 0;
175 	int eap = 0; /* expect action parameters */
176 
177 	int ret = 0;
178 	int prio = 0;
179 
180 	if (argc <= 0)
181 		return -1;
182 
183 	tail = tail2 = NLMSG_TAIL(n);
184 
185 	addattr_l(n, MAX_MSG, tca_id, NULL, 0);
186 
187 	while (argc > 0) {
188 
189 		memset(k, 0, sizeof (k));
190 
191 		if (strcmp(*argv, "action") == 0 ) {
192 			argc--;
193 			argv++;
194 			eap = 1;
195 #ifdef CONFIG_GACT
196 			if (!gact_ld) {
197 				get_action_kind("gact");
198 			}
199 #endif
200 			continue;
201 		} else if (strcmp(*argv, "help") == 0) {
202 			return -1;
203 		} else if (new_cmd(argv)) {
204 			goto done0;
205 		} else {
206 			struct action_util *a = NULL;
207 			strncpy(k, *argv, sizeof (k) - 1);
208 			eap = 0;
209 			if (argc > 0 ) {
210 				a = get_action_kind(k);
211 			} else {
212 done0:
213 				if (ok)
214 					break;
215 				else
216 					goto done;
217 			}
218 
219 			if (NULL == a) {
220 				goto bad_val;
221 			}
222 
223 			tail = NLMSG_TAIL(n);
224 			addattr_l(n, MAX_MSG, ++prio, NULL, 0);
225 			addattr_l(n, MAX_MSG, TCA_ACT_KIND, k, strlen(k) + 1);
226 
227 			ret = a->parse_aopt(a,&argc, &argv, TCA_ACT_OPTIONS, n);
228 
229 			if (ret < 0) {
230 				fprintf(stderr,"bad action parsing\n");
231 				goto bad_val;
232 			}
233 			tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
234 			ok++;
235 		}
236 
237 	}
238 
239 	if (eap > 0) {
240 		fprintf(stderr,"bad action empty %d\n",eap);
241 		goto bad_val;
242 	}
243 
244 	tail2->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail2;
245 
246 done:
247 	*argc_p = argc;
248 	*argv_p = argv;
249 	return 0;
250 bad_val:
251 	/* no need to undo things, returning from here should
252 	 * cause enough pain */
253 	fprintf(stderr, "parse_action: bad value (%d:%s)!\n",argc,*argv);
254 	return -1;
255 }
256 
257 int
tc_print_one_action(FILE * f,struct rtattr * arg)258 tc_print_one_action(FILE * f, struct rtattr *arg)
259 {
260 
261 	struct rtattr *tb[TCA_ACT_MAX + 1];
262 	int err = 0;
263 	struct action_util *a = NULL;
264 
265 	if (arg == NULL)
266 		return -1;
267 
268 	parse_rtattr_nested(tb, TCA_ACT_MAX, arg);
269 	if (tb[TCA_ACT_KIND] == NULL) {
270 		fprintf(stderr, "NULL Action!\n");
271 		return -1;
272 	}
273 
274 
275 	a = get_action_kind(RTA_DATA(tb[TCA_ACT_KIND]));
276 	if (NULL == a)
277 		return err;
278 
279 	if (tab_flush) {
280 		fprintf(f," %s \n", a->id);
281 		tab_flush = 0;
282 		return 0;
283 	}
284 
285 	err = a->print_aopt(a,f,tb[TCA_ACT_OPTIONS]);
286 
287 
288 	if (0 > err)
289 		return err;
290 
291 	if (show_stats && tb[TCA_ACT_STATS]) {
292 		fprintf(f, "\tAction statistics:\n");
293 		print_tcstats2_attr(f, tb[TCA_ACT_STATS], "\t", NULL);
294 		fprintf(f, "\n");
295 	}
296 
297 	return 0;
298 }
299 
300 int
tc_print_action(FILE * f,const struct rtattr * arg)301 tc_print_action(FILE * f, const struct rtattr *arg)
302 {
303 
304 	int i;
305 	struct rtattr *tb[TCA_ACT_MAX_PRIO + 1];
306 
307 	if (arg == NULL)
308 		return 0;
309 
310 	parse_rtattr_nested(tb, TCA_ACT_MAX_PRIO, arg);
311 
312 	if (tab_flush && NULL != tb[0]  && NULL == tb[1]) {
313 		int ret = tc_print_one_action(f, tb[0]);
314 		return ret;
315 	}
316 
317 	for (i = 0; i < TCA_ACT_MAX_PRIO; i++) {
318 		if (tb[i]) {
319 			fprintf(f, "\n\taction order %d: ", i + batch_c);
320 			if (0 > tc_print_one_action(f, tb[i])) {
321 				fprintf(f, "Error printing action\n");
322 			}
323 		}
324 
325 	}
326 
327 	batch_c+=TCA_ACT_MAX_PRIO ;
328 	return 0;
329 }
330 
print_action(const struct sockaddr_nl * who,struct nlmsghdr * n,void * arg)331 int print_action(const struct sockaddr_nl *who,
332 			   struct nlmsghdr *n,
333 			   void *arg)
334 {
335 	FILE *fp = (FILE*)arg;
336 	struct tcamsg *t = NLMSG_DATA(n);
337 	int len = n->nlmsg_len;
338 	struct rtattr * tb[TCAA_MAX+1];
339 
340 	len -= NLMSG_LENGTH(sizeof(*t));
341 
342 	if (len < 0) {
343 		fprintf(stderr, "Wrong len %d\n", len);
344 		return -1;
345 	}
346 
347 	parse_rtattr(tb, TCAA_MAX, TA_RTA(t), len);
348 
349 	if (NULL == tb[TCA_ACT_TAB]) {
350 		if (n->nlmsg_type != RTM_GETACTION)
351 			fprintf(stderr, "print_action: NULL kind\n");
352 		return -1;
353 	}
354 
355 	if (n->nlmsg_type == RTM_DELACTION) {
356 		if (n->nlmsg_flags & NLM_F_ROOT) {
357 			fprintf(fp, "Flushed table ");
358 			tab_flush = 1;
359 		} else {
360 			fprintf(fp, "deleted action ");
361 		}
362 	}
363 
364 	if (n->nlmsg_type == RTM_NEWACTION)
365 		fprintf(fp, "Added action ");
366 	tc_print_action(fp, tb[TCA_ACT_TAB]);
367 
368 	return 0;
369 }
370 
tc_action_gd(int cmd,unsigned flags,int * argc_p,char *** argv_p)371 int tc_action_gd(int cmd, unsigned flags, int *argc_p, char ***argv_p)
372 {
373 	char k[16];
374 	struct action_util *a = NULL;
375 	int argc = *argc_p;
376 	char **argv = *argv_p;
377 	int prio = 0;
378 	int ret = 0;
379 	__u32 i;
380 	struct sockaddr_nl nladdr;
381 	struct rtattr *tail;
382 	struct rtattr *tail2;
383 	struct nlmsghdr *ans = NULL;
384 
385 	struct {
386 		struct nlmsghdr         n;
387 		struct tcamsg           t;
388 		char                    buf[MAX_MSG];
389 	} req;
390 
391 	req.t.tca_family = AF_UNSPEC;
392 
393 	memset(&req, 0, sizeof(req));
394 
395 	memset(&nladdr, 0, sizeof(nladdr));
396 	nladdr.nl_family = AF_NETLINK;
397 
398 	req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcamsg));
399 	req.n.nlmsg_flags = NLM_F_REQUEST|flags;
400 	req.n.nlmsg_type = cmd;
401 	argc -=1;
402 	argv +=1;
403 
404 
405 	tail = NLMSG_TAIL(&req.n);
406 	addattr_l(&req.n, MAX_MSG, TCA_ACT_TAB, NULL, 0);
407 
408 	while (argc > 0) {
409 		if (strcmp(*argv, "action") == 0 ) {
410 			argc--;
411 			argv++;
412 			continue;
413 		} else if (strcmp(*argv, "help") == 0) {
414 			return -1;
415 		}
416 
417 		strncpy(k, *argv, sizeof (k) - 1);
418 		a = get_action_kind(k);
419 		if (NULL == a) {
420 			fprintf(stderr, "Error: non existent action: %s\n",k);
421 			ret = -1;
422 			goto bad_val;
423 		}
424 		if (strcmp(a->id, k) != 0) {
425 			fprintf(stderr, "Error: non existent action: %s\n",k);
426 			ret = -1;
427 			goto bad_val;
428 		}
429 
430 		argc -=1;
431 		argv +=1;
432 		if (argc <= 0) {
433 			fprintf(stderr, "Error: no index specified action: %s\n",k);
434 			ret = -1;
435 			goto bad_val;
436 		}
437 
438 		if (matches(*argv, "index") == 0) {
439 			NEXT_ARG();
440 			if (get_u32(&i, *argv, 10)) {
441 				fprintf(stderr, "Illegal \"index\"\n");
442 				ret = -1;
443 				goto bad_val;
444 			}
445 			argc -=1;
446 			argv +=1;
447 		} else {
448 			fprintf(stderr, "Error: no index specified action: %s\n",k);
449 			ret = -1;
450 			goto bad_val;
451 		}
452 
453 		tail2 = NLMSG_TAIL(&req.n);
454 		addattr_l(&req.n, MAX_MSG, ++prio, NULL, 0);
455 		addattr_l(&req.n, MAX_MSG, TCA_ACT_KIND, k, strlen(k) + 1);
456 		addattr32(&req.n, MAX_MSG, TCA_ACT_INDEX, i);
457 		tail2->rta_len = (void *) NLMSG_TAIL(&req.n) - (void *) tail2;
458 
459 	}
460 
461 	tail->rta_len = (void *) NLMSG_TAIL(&req.n) - (void *) tail;
462 
463 	req.n.nlmsg_seq = rth.dump = ++rth.seq;
464 	if (cmd == RTM_GETACTION)
465 		ans = &req.n;
466 
467 	if (rtnl_talk(&rth, &req.n, 0, 0, ans, NULL, NULL) < 0) {
468 		fprintf(stderr, "We have an error talking to the kernel\n");
469 		return 1;
470 	}
471 
472 	if (ans && print_action(NULL, &req.n, (void*)stdout) < 0) {
473 		fprintf(stderr, "Dump terminated\n");
474 		return 1;
475 	}
476 
477 	*argc_p = argc;
478 	*argv_p = argv;
479 bad_val:
480 	return ret;
481 }
482 
tc_action_modify(int cmd,unsigned flags,int * argc_p,char *** argv_p)483 int tc_action_modify(int cmd, unsigned flags, int *argc_p, char ***argv_p)
484 {
485 	int argc = *argc_p;
486 	char **argv = *argv_p;
487 	int ret = 0;
488 
489 	struct rtattr *tail;
490 	struct {
491 		struct nlmsghdr         n;
492 		struct tcamsg           t;
493 		char                    buf[MAX_MSG];
494 	} req;
495 
496 	req.t.tca_family = AF_UNSPEC;
497 
498 	memset(&req, 0, sizeof(req));
499 
500 	req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcamsg));
501 	req.n.nlmsg_flags = NLM_F_REQUEST|flags;
502 	req.n.nlmsg_type = cmd;
503 	tail = NLMSG_TAIL(&req.n);
504 	argc -=1;
505 	argv +=1;
506 	if (parse_action(&argc, &argv, TCA_ACT_TAB, &req.n)) {
507 		fprintf(stderr, "Illegal \"action\"\n");
508 		return -1;
509 	}
510 	tail->rta_len = (void *) NLMSG_TAIL(&req.n) - (void *) tail;
511 
512 	if (rtnl_talk(&rth, &req.n, 0, 0, NULL, NULL, NULL) < 0) {
513 		fprintf(stderr, "We have an error talking to the kernel\n");
514 		ret = -1;
515 	}
516 
517 	*argc_p = argc;
518 	*argv_p = argv;
519 
520 	return ret;
521 }
522 
tc_act_list_or_flush(int argc,char ** argv,int event)523 int tc_act_list_or_flush(int argc, char **argv, int event)
524 {
525 	int ret = 0, prio = 0, msg_size = 0;
526 	char k[16];
527 	struct rtattr *tail,*tail2;
528 	struct action_util *a = NULL;
529 	struct {
530 		struct nlmsghdr         n;
531 		struct tcamsg           t;
532 		char                    buf[MAX_MSG];
533 	} req;
534 
535 	req.t.tca_family = AF_UNSPEC;
536 
537 	memset(&req, 0, sizeof(req));
538 
539 	req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcamsg));
540 
541 	tail = NLMSG_TAIL(&req.n);
542 	addattr_l(&req.n, MAX_MSG, TCA_ACT_TAB, NULL, 0);
543 	tail2 = NLMSG_TAIL(&req.n);
544 
545 	strncpy(k, *argv, sizeof (k) - 1);
546 #ifdef CONFIG_GACT
547 	if (!gact_ld) {
548 		get_action_kind("gact");
549 	}
550 #endif
551 	a = get_action_kind(k);
552 	if (NULL == a) {
553 		fprintf(stderr,"bad action %s\n",k);
554 		goto bad_val;
555 	}
556 	if (strcmp(a->id, k) != 0) {
557 		fprintf(stderr,"bad action %s\n",k);
558 		goto bad_val;
559 	}
560 	strncpy(k, *argv, sizeof (k) - 1);
561 
562 	addattr_l(&req.n, MAX_MSG, ++prio, NULL, 0);
563 	addattr_l(&req.n, MAX_MSG, TCA_ACT_KIND, k, strlen(k) + 1);
564 	tail2->rta_len = (void *) NLMSG_TAIL(&req.n) - (void *) tail2;
565 	tail->rta_len = (void *) NLMSG_TAIL(&req.n) - (void *) tail;
566 
567 	msg_size = NLMSG_ALIGN(req.n.nlmsg_len) - NLMSG_ALIGN(sizeof(struct nlmsghdr));
568 
569 	if (event == RTM_GETACTION) {
570 		if (rtnl_dump_request(&rth, event, (void *)&req.t, msg_size) < 0) {
571 			perror("Cannot send dump request");
572 			return 1;
573 		}
574 		ret = rtnl_dump_filter(&rth, print_action, stdout, NULL, NULL);
575 	}
576 
577 	if (event == RTM_DELACTION) {
578 		req.n.nlmsg_len = NLMSG_ALIGN(req.n.nlmsg_len);
579 		req.n.nlmsg_type = RTM_DELACTION;
580 		req.n.nlmsg_flags |= NLM_F_ROOT;
581 		req.n.nlmsg_flags |= NLM_F_REQUEST;
582 		if (rtnl_talk(&rth, &req.n, 0, 0, NULL, NULL, NULL) < 0) {
583 			fprintf(stderr, "We have an error flushing\n");
584 			return 1;
585 		}
586 
587 	}
588 
589 bad_val:
590 
591 	return ret;
592 }
593 
do_action(int argc,char ** argv)594 int do_action(int argc, char **argv)
595 {
596 
597 	int ret = 0;
598 
599 	while (argc > 0) {
600 
601 		if (matches(*argv, "add") == 0) {
602 			ret =  tc_action_modify(RTM_NEWACTION, NLM_F_EXCL|NLM_F_CREATE, &argc, &argv);
603 		} else if (matches(*argv, "change") == 0 ||
604 			  matches(*argv, "replace") == 0) {
605 			ret = tc_action_modify(RTM_NEWACTION, NLM_F_CREATE|NLM_F_REPLACE, &argc, &argv);
606 		} else if (matches(*argv, "delete") == 0) {
607 			argc -=1;
608 			argv +=1;
609 			ret = tc_action_gd(RTM_DELACTION, 0,  &argc, &argv);
610 		} else if (matches(*argv, "get") == 0) {
611 			argc -=1;
612 			argv +=1;
613 			ret = tc_action_gd(RTM_GETACTION, 0,  &argc, &argv);
614 		} else if (matches(*argv, "list") == 0 || matches(*argv, "show") == 0
615 						|| matches(*argv, "lst") == 0) {
616 			if (argc <= 2) {
617 				act_usage();
618 				return -1;
619 			}
620 			return tc_act_list_or_flush(argc-2, argv+2, RTM_GETACTION);
621 		} else if (matches(*argv, "flush") == 0) {
622 			if (argc <= 2) {
623 				act_usage();
624 				return -1;
625 			}
626 			return tc_act_list_or_flush(argc-2, argv+2, RTM_DELACTION);
627 		} else if (matches(*argv, "help") == 0) {
628 			act_usage();
629 			return -1;
630 		} else {
631 
632 			ret = -1;
633 		}
634 
635 		if (ret < 0) {
636 			fprintf(stderr, "Command \"%s\" is unknown, try \"tc actions help\".\n", *argv);
637 			return -1;
638 		}
639 	}
640 
641 	return 0;
642 }
643 
644