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1 /*
2  * tc_filter.c		"tc filter".
3  *
4  *		This program is free software; you can redistribute 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:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10  *
11  */
12 
13 #include <stdio.h>
14 #include <stdlib.h>
15 #include <unistd.h>
16 #include <syslog.h>
17 #include <fcntl.h>
18 #include <sys/socket.h>
19 #include <netinet/in.h>
20 #include <arpa/inet.h>
21 #include <string.h>
22 #include <linux/if_ether.h>
23 
24 #include "rt_names.h"
25 #include "utils.h"
26 #include "tc_util.h"
27 #include "tc_common.h"
28 
usage(void)29 static void usage(void)
30 {
31 	fprintf(stderr,
32 		"Usage: tc filter [ add | del | change | replace | show ] dev STRING\n"
33 		"Usage: tc filter get dev STRING parent CLASSID protocol PROTO handle FILTERID pref PRIO FILTER_TYPE\n"
34 		"       [ pref PRIO ] protocol PROTO [ chain CHAIN_INDEX ]\n"
35 		"       [ estimator INTERVAL TIME_CONSTANT ]\n"
36 		"       [ root | ingress | egress | parent CLASSID ]\n"
37 		"       [ handle FILTERID ] [ [ FILTER_TYPE ] [ help | OPTIONS ] ]\n"
38 		"\n"
39 		"       tc filter show [ dev STRING ] [ root | ingress | egress | parent CLASSID ]\n"
40 		"Where:\n"
41 		"FILTER_TYPE := { rsvp | u32 | bpf | fw | route | etc. }\n"
42 		"FILTERID := ... format depends on classifier, see there\n"
43 		"OPTIONS := ... try tc filter add <desired FILTER_KIND> help\n");
44 }
45 
tc_filter_modify(int cmd,unsigned int flags,int argc,char ** argv)46 static int tc_filter_modify(int cmd, unsigned int flags, int argc, char **argv)
47 {
48 	struct {
49 		struct nlmsghdr	n;
50 		struct tcmsg		t;
51 		char			buf[MAX_MSG];
52 	} req = {
53 		.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
54 		.n.nlmsg_flags = NLM_F_REQUEST | flags,
55 		.n.nlmsg_type = cmd,
56 		.t.tcm_family = AF_UNSPEC,
57 	};
58 	struct filter_util *q = NULL;
59 	__u32 prio = 0;
60 	__u32 protocol = 0;
61 	int protocol_set = 0;
62 	__u32 chain_index;
63 	int chain_index_set = 0;
64 	char *fhandle = NULL;
65 	char  d[16] = {};
66 	char  k[16] = {};
67 	struct tc_estimator est = {};
68 
69 	if (cmd == RTM_NEWTFILTER && flags & NLM_F_CREATE)
70 		protocol = htons(ETH_P_ALL);
71 
72 	while (argc > 0) {
73 		if (strcmp(*argv, "dev") == 0) {
74 			NEXT_ARG();
75 			if (d[0])
76 				duparg("dev", *argv);
77 			strncpy(d, *argv, sizeof(d)-1);
78 		} else if (strcmp(*argv, "root") == 0) {
79 			if (req.t.tcm_parent) {
80 				fprintf(stderr,
81 					"Error: \"root\" is duplicate parent ID\n");
82 				return -1;
83 			}
84 			req.t.tcm_parent = TC_H_ROOT;
85 		} else if (strcmp(*argv, "ingress") == 0) {
86 			if (req.t.tcm_parent) {
87 				fprintf(stderr,
88 					"Error: \"ingress\" is duplicate parent ID\n");
89 				return -1;
90 			}
91 			req.t.tcm_parent = TC_H_MAKE(TC_H_CLSACT,
92 						     TC_H_MIN_INGRESS);
93 		} else if (strcmp(*argv, "egress") == 0) {
94 			if (req.t.tcm_parent) {
95 				fprintf(stderr,
96 					"Error: \"egress\" is duplicate parent ID\n");
97 				return -1;
98 			}
99 			req.t.tcm_parent = TC_H_MAKE(TC_H_CLSACT,
100 						     TC_H_MIN_EGRESS);
101 		} else if (strcmp(*argv, "parent") == 0) {
102 			__u32 handle;
103 
104 			NEXT_ARG();
105 			if (req.t.tcm_parent)
106 				duparg("parent", *argv);
107 			if (get_tc_classid(&handle, *argv))
108 				invarg("Invalid parent ID", *argv);
109 			req.t.tcm_parent = handle;
110 		} else if (strcmp(*argv, "handle") == 0) {
111 			NEXT_ARG();
112 			if (fhandle)
113 				duparg("handle", *argv);
114 			fhandle = *argv;
115 		} else if (matches(*argv, "preference") == 0 ||
116 			   matches(*argv, "priority") == 0) {
117 			NEXT_ARG();
118 			if (prio)
119 				duparg("priority", *argv);
120 			if (get_u32(&prio, *argv, 0) || prio > 0xFFFF)
121 				invarg("invalid priority value", *argv);
122 		} else if (matches(*argv, "protocol") == 0) {
123 			__u16 id;
124 
125 			NEXT_ARG();
126 			if (protocol_set)
127 				duparg("protocol", *argv);
128 			if (ll_proto_a2n(&id, *argv))
129 				invarg("invalid protocol", *argv);
130 			protocol = id;
131 			protocol_set = 1;
132 		} else if (matches(*argv, "chain") == 0) {
133 			NEXT_ARG();
134 			if (chain_index_set)
135 				duparg("chain", *argv);
136 			if (get_u32(&chain_index, *argv, 0))
137 				invarg("invalid chain index value", *argv);
138 			chain_index_set = 1;
139 		} else if (matches(*argv, "estimator") == 0) {
140 			if (parse_estimator(&argc, &argv, &est) < 0)
141 				return -1;
142 		} else if (matches(*argv, "help") == 0) {
143 			usage();
144 			return 0;
145 		} else {
146 			strncpy(k, *argv, sizeof(k)-1);
147 
148 			q = get_filter_kind(k);
149 			argc--; argv++;
150 			break;
151 		}
152 
153 		argc--; argv++;
154 	}
155 
156 	req.t.tcm_info = TC_H_MAKE(prio<<16, protocol);
157 
158 	if (chain_index_set)
159 		addattr32(&req.n, sizeof(req), TCA_CHAIN, chain_index);
160 
161 	if (k[0])
162 		addattr_l(&req.n, sizeof(req), TCA_KIND, k, strlen(k)+1);
163 
164 	if (q) {
165 		if (q->parse_fopt(q, fhandle, argc, argv, &req.n))
166 			return 1;
167 	} else {
168 		if (fhandle) {
169 			fprintf(stderr,
170 				"Must specify filter type when using \"handle\"\n");
171 			return -1;
172 		}
173 		if (argc) {
174 			if (matches(*argv, "help") == 0)
175 				usage();
176 			fprintf(stderr,
177 				"Garbage instead of arguments \"%s ...\". Try \"tc filter help\".\n",
178 				*argv);
179 			return -1;
180 		}
181 	}
182 
183 	if (est.ewma_log)
184 		addattr_l(&req.n, sizeof(req), TCA_RATE, &est, sizeof(est));
185 
186 
187 	if (d[0])  {
188 		ll_init_map(&rth);
189 
190 		req.t.tcm_ifindex = ll_name_to_index(d);
191 		if (req.t.tcm_ifindex == 0) {
192 			fprintf(stderr, "Cannot find device \"%s\"\n", d);
193 			return 1;
194 		}
195 	}
196 
197 	if (rtnl_talk(&rth, &req.n, NULL, 0) < 0) {
198 		fprintf(stderr, "We have an error talking to the kernel\n");
199 		return 2;
200 	}
201 
202 	return 0;
203 }
204 
205 static __u32 filter_parent;
206 static int filter_ifindex;
207 static __u32 filter_prio;
208 static __u32 filter_protocol;
209 static __u32 filter_chain_index;
210 static int filter_chain_index_set;
211 __u16 f_proto;
212 
print_filter(const struct sockaddr_nl * who,struct nlmsghdr * n,void * arg)213 int print_filter(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
214 {
215 	FILE *fp = (FILE *)arg;
216 	struct tcmsg *t = NLMSG_DATA(n);
217 	int len = n->nlmsg_len;
218 	struct rtattr *tb[TCA_MAX+1];
219 	struct filter_util *q;
220 	char abuf[256];
221 
222 	if (n->nlmsg_type != RTM_NEWTFILTER &&
223 	    n->nlmsg_type != RTM_GETTFILTER &&
224 	    n->nlmsg_type != RTM_DELTFILTER) {
225 		fprintf(stderr, "Not a filter(cmd %d)\n", n->nlmsg_type);
226 		return 0;
227 	}
228 	len -= NLMSG_LENGTH(sizeof(*t));
229 	if (len < 0) {
230 		fprintf(stderr, "Wrong len %d\n", len);
231 		return -1;
232 	}
233 
234 	parse_rtattr(tb, TCA_MAX, TCA_RTA(t), len);
235 
236 	if (tb[TCA_KIND] == NULL) {
237 		fprintf(stderr, "print_filter: NULL kind\n");
238 		return -1;
239 	}
240 
241 	if (n->nlmsg_type == RTM_DELTFILTER)
242 		fprintf(fp, "deleted ");
243 
244 	if (n->nlmsg_type == RTM_NEWTFILTER &&
245 			(n->nlmsg_flags & NLM_F_CREATE) &&
246 			!(n->nlmsg_flags & NLM_F_EXCL))
247 		fprintf(fp, "replaced ");
248 
249 	if (n->nlmsg_type == RTM_NEWTFILTER &&
250 			(n->nlmsg_flags & NLM_F_CREATE) &&
251 			(n->nlmsg_flags & NLM_F_EXCL))
252 		fprintf(fp, "added ");
253 
254 	fprintf(fp, "filter ");
255 	if (!filter_ifindex || filter_ifindex != t->tcm_ifindex)
256 		fprintf(fp, "dev %s ", ll_index_to_name(t->tcm_ifindex));
257 
258 	if (!filter_parent || filter_parent != t->tcm_parent) {
259 		if (t->tcm_parent == TC_H_ROOT)
260 			fprintf(fp, "root ");
261 		else if (t->tcm_parent == TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_INGRESS))
262 			fprintf(fp, "ingress ");
263 		else if (t->tcm_parent == TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_EGRESS))
264 			fprintf(fp, "egress ");
265 		else {
266 			print_tc_classid(abuf, sizeof(abuf), t->tcm_parent);
267 			fprintf(fp, "parent %s ", abuf);
268 		}
269 	}
270 
271 	if (t->tcm_info) {
272 		f_proto = TC_H_MIN(t->tcm_info);
273 		__u32 prio = TC_H_MAJ(t->tcm_info)>>16;
274 
275 		if (!filter_protocol || filter_protocol != f_proto) {
276 			if (f_proto) {
277 				SPRINT_BUF(b1);
278 				fprintf(fp, "protocol %s ",
279 					ll_proto_n2a(f_proto, b1, sizeof(b1)));
280 			}
281 		}
282 		if (!filter_prio || filter_prio != prio) {
283 			if (prio)
284 				fprintf(fp, "pref %u ", prio);
285 		}
286 	}
287 	fprintf(fp, "%s ", rta_getattr_str(tb[TCA_KIND]));
288 
289 	if (tb[TCA_CHAIN]) {
290 		__u32 chain_index = rta_getattr_u32(tb[TCA_CHAIN]);
291 
292 		if (!filter_chain_index_set ||
293 		    filter_chain_index != chain_index)
294 			fprintf(fp, "chain %u ", chain_index);
295 	}
296 
297 	q = get_filter_kind(RTA_DATA(tb[TCA_KIND]));
298 	if (tb[TCA_OPTIONS]) {
299 		if (q)
300 			q->print_fopt(q, fp, tb[TCA_OPTIONS], t->tcm_handle);
301 		else
302 			fprintf(fp, "[cannot parse parameters]");
303 	}
304 	fprintf(fp, "\n");
305 
306 	if (show_stats && (tb[TCA_STATS] || tb[TCA_STATS2])) {
307 		print_tcstats_attr(fp, tb, " ", NULL);
308 		fprintf(fp, "\n");
309 	}
310 
311 	fflush(fp);
312 	return 0;
313 }
314 
tc_filter_get(int cmd,unsigned int flags,int argc,char ** argv)315 static int tc_filter_get(int cmd, unsigned int flags, int argc, char **argv)
316 {
317 	struct {
318 		struct nlmsghdr	n;
319 		struct tcmsg		t;
320 		char			buf[MAX_MSG];
321 	} req = {
322 		.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
323 		/* NLM_F_ECHO is for backward compatibility. old kernels never
324 		 * respond without it and newer kernels will ignore it.
325 		 * In old kernels there is a side effect:
326 		 * In addition to a response to the GET you will receive an
327 		 * event (if you do tc mon).
328 		 */
329 		.n.nlmsg_flags = NLM_F_REQUEST | NLM_F_ECHO | flags,
330 		.n.nlmsg_type = cmd,
331 		.t.tcm_parent = TC_H_UNSPEC,
332 		.t.tcm_family = AF_UNSPEC,
333 	};
334 	struct filter_util *q = NULL;
335 	__u32 prio = 0;
336 	__u32 protocol = 0;
337 	int protocol_set = 0;
338 	__u32 chain_index;
339 	int chain_index_set = 0;
340 	__u32 parent_handle = 0;
341 	char *fhandle = NULL;
342 	char  d[16] = {};
343 	char  k[16] = {};
344 
345 	while (argc > 0) {
346 		if (strcmp(*argv, "dev") == 0) {
347 			NEXT_ARG();
348 			if (d[0])
349 				duparg("dev", *argv);
350 			strncpy(d, *argv, sizeof(d)-1);
351 		} else if (strcmp(*argv, "root") == 0) {
352 			if (req.t.tcm_parent) {
353 				fprintf(stderr,
354 					"Error: \"root\" is duplicate parent ID\n");
355 				return -1;
356 			}
357 			req.t.tcm_parent = TC_H_ROOT;
358 		} else if (strcmp(*argv, "ingress") == 0) {
359 			if (req.t.tcm_parent) {
360 				fprintf(stderr,
361 					"Error: \"ingress\" is duplicate parent ID\n");
362 				return -1;
363 			}
364 			req.t.tcm_parent = TC_H_MAKE(TC_H_CLSACT,
365 						     TC_H_MIN_INGRESS);
366 		} else if (strcmp(*argv, "egress") == 0) {
367 			if (req.t.tcm_parent) {
368 				fprintf(stderr,
369 					"Error: \"egress\" is duplicate parent ID\n");
370 				return -1;
371 			}
372 			req.t.tcm_parent = TC_H_MAKE(TC_H_CLSACT,
373 						     TC_H_MIN_EGRESS);
374 		} else if (strcmp(*argv, "parent") == 0) {
375 
376 			NEXT_ARG();
377 			if (req.t.tcm_parent)
378 				duparg("parent", *argv);
379 			if (get_tc_classid(&parent_handle, *argv))
380 				invarg("Invalid parent ID", *argv);
381 			req.t.tcm_parent = parent_handle;
382 		} else if (strcmp(*argv, "handle") == 0) {
383 			NEXT_ARG();
384 			if (fhandle)
385 				duparg("handle", *argv);
386 			fhandle = *argv;
387 		} else if (matches(*argv, "preference") == 0 ||
388 			   matches(*argv, "priority") == 0) {
389 			NEXT_ARG();
390 			if (prio)
391 				duparg("priority", *argv);
392 			if (get_u32(&prio, *argv, 0) || prio > 0xFFFF)
393 				invarg("invalid priority value", *argv);
394 		} else if (matches(*argv, "protocol") == 0) {
395 			__u16 id;
396 
397 			NEXT_ARG();
398 			if (protocol_set)
399 				duparg("protocol", *argv);
400 			if (ll_proto_a2n(&id, *argv))
401 				invarg("invalid protocol", *argv);
402 			protocol = id;
403 			protocol_set = 1;
404 		} else if (matches(*argv, "chain") == 0) {
405 			NEXT_ARG();
406 			if (chain_index_set)
407 				duparg("chain", *argv);
408 			if (get_u32(&chain_index, *argv, 0))
409 				invarg("invalid chain index value", *argv);
410 			chain_index_set = 1;
411 		} else if (matches(*argv, "help") == 0) {
412 			usage();
413 			return 0;
414 		} else {
415 			if (!**argv)
416 				invarg("invalid filter name", *argv);
417 
418 			strncpy(k, *argv, sizeof(k)-1);
419 
420 			q = get_filter_kind(k);
421 			argc--; argv++;
422 			break;
423 		}
424 
425 		argc--; argv++;
426 	}
427 
428 	if (!protocol_set) {
429 		fprintf(stderr, "Must specify filter protocol\n");
430 		return -1;
431 	}
432 
433 	if (!prio) {
434 		fprintf(stderr, "Must specify filter priority\n");
435 		return -1;
436 	}
437 
438 	req.t.tcm_info = TC_H_MAKE(prio<<16, protocol);
439 
440 	if (chain_index_set)
441 		addattr32(&req.n, sizeof(req), TCA_CHAIN, chain_index);
442 
443 	if (req.t.tcm_parent == TC_H_UNSPEC) {
444 		fprintf(stderr, "Must specify filter parent\n");
445 		return -1;
446 	}
447 
448 	if (k[0])
449 		addattr_l(&req.n, sizeof(req), TCA_KIND, k, strlen(k)+1);
450 	else {
451 		fprintf(stderr, "Must specify filter type\n");
452 		return -1;
453 	}
454 
455 	if (q->parse_fopt(q, fhandle, argc, argv, &req.n))
456 		return 1;
457 
458 
459 	if (!fhandle) {
460 		fprintf(stderr, "Must specify filter \"handle\"\n");
461 		return -1;
462 	}
463 
464 	if (argc) {
465 		if (matches(*argv, "help") == 0)
466 			usage();
467 		fprintf(stderr,
468 			"Garbage instead of arguments \"%s ...\". Try \"tc filter help\".\n",
469 			*argv);
470 		return -1;
471 	}
472 
473 	if (d[0])  {
474 		ll_init_map(&rth);
475 
476 		req.t.tcm_ifindex = ll_name_to_index(d);
477 		if (req.t.tcm_ifindex  == 0) {
478 			fprintf(stderr, "Cannot find device \"%s\"\n", d);
479 			return 1;
480 		}
481 		filter_ifindex = req.t.tcm_ifindex;
482 	} else {
483 		fprintf(stderr, "Must specify netdevice \"dev\"\n");
484 		return -1;
485 	}
486 
487 	if (rtnl_talk(&rth, &req.n, &req.n, MAX_MSG) < 0) {
488 		fprintf(stderr, "We have an error talking to the kernel\n");
489 		return 2;
490 	}
491 
492 	print_filter(NULL, &req.n, (void *)stdout);
493 
494 	return 0;
495 }
496 
tc_filter_list(int argc,char ** argv)497 static int tc_filter_list(int argc, char **argv)
498 {
499 	struct {
500 		struct nlmsghdr n;
501 		struct tcmsg t;
502 		char buf[MAX_MSG];
503 	} req = {
504 		.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
505 		.n.nlmsg_type = RTM_GETTFILTER,
506 		.t.tcm_parent = TC_H_UNSPEC,
507 		.t.tcm_family = AF_UNSPEC,
508 	};
509 	char d[16] = {};
510 	__u32 prio = 0;
511 	__u32 protocol = 0;
512 	__u32 chain_index;
513 	char *fhandle = NULL;
514 
515 	while (argc > 0) {
516 		if (strcmp(*argv, "dev") == 0) {
517 			NEXT_ARG();
518 			if (d[0])
519 				duparg("dev", *argv);
520 			strncpy(d, *argv, sizeof(d)-1);
521 		} else if (strcmp(*argv, "root") == 0) {
522 			if (req.t.tcm_parent) {
523 				fprintf(stderr,
524 					"Error: \"root\" is duplicate parent ID\n");
525 				return -1;
526 			}
527 			filter_parent = req.t.tcm_parent = TC_H_ROOT;
528 		} else if (strcmp(*argv, "ingress") == 0) {
529 			if (req.t.tcm_parent) {
530 				fprintf(stderr,
531 					"Error: \"ingress\" is duplicate parent ID\n");
532 				return -1;
533 			}
534 			filter_parent = TC_H_MAKE(TC_H_CLSACT,
535 						  TC_H_MIN_INGRESS);
536 			req.t.tcm_parent = filter_parent;
537 		} else if (strcmp(*argv, "egress") == 0) {
538 			if (req.t.tcm_parent) {
539 				fprintf(stderr,
540 					"Error: \"egress\" is duplicate parent ID\n");
541 				return -1;
542 			}
543 			filter_parent = TC_H_MAKE(TC_H_CLSACT,
544 						  TC_H_MIN_EGRESS);
545 			req.t.tcm_parent = filter_parent;
546 		} else if (strcmp(*argv, "parent") == 0) {
547 			__u32 handle;
548 
549 			NEXT_ARG();
550 			if (req.t.tcm_parent)
551 				duparg("parent", *argv);
552 			if (get_tc_classid(&handle, *argv))
553 				invarg("invalid parent ID", *argv);
554 			filter_parent = req.t.tcm_parent = handle;
555 		} else if (strcmp(*argv, "handle") == 0) {
556 			NEXT_ARG();
557 			if (fhandle)
558 				duparg("handle", *argv);
559 			fhandle = *argv;
560 		} else if (matches(*argv, "preference") == 0 ||
561 			   matches(*argv, "priority") == 0) {
562 			NEXT_ARG();
563 			if (prio)
564 				duparg("priority", *argv);
565 			if (get_u32(&prio, *argv, 0))
566 				invarg("invalid preference", *argv);
567 			filter_prio = prio;
568 		} else if (matches(*argv, "protocol") == 0) {
569 			__u16 res;
570 
571 			NEXT_ARG();
572 			if (protocol)
573 				duparg("protocol", *argv);
574 			if (ll_proto_a2n(&res, *argv))
575 				invarg("invalid protocol", *argv);
576 			protocol = res;
577 			filter_protocol = protocol;
578 		} else if (matches(*argv, "chain") == 0) {
579 			NEXT_ARG();
580 			if (filter_chain_index_set)
581 				duparg("chain", *argv);
582 			if (get_u32(&chain_index, *argv, 0))
583 				invarg("invalid chain index value", *argv);
584 			filter_chain_index_set = 1;
585 			filter_chain_index = chain_index;
586 		} else if (matches(*argv, "help") == 0) {
587 			usage();
588 		} else {
589 			fprintf(stderr,
590 				" What is \"%s\"? Try \"tc filter help\"\n",
591 				*argv);
592 			return -1;
593 		}
594 
595 		argc--; argv++;
596 	}
597 
598 	req.t.tcm_info = TC_H_MAKE(prio<<16, protocol);
599 
600 	ll_init_map(&rth);
601 
602 	if (d[0]) {
603 		req.t.tcm_ifindex = ll_name_to_index(d);
604 		if (req.t.tcm_ifindex == 0) {
605 			fprintf(stderr, "Cannot find device \"%s\"\n", d);
606 			return 1;
607 		}
608 		filter_ifindex = req.t.tcm_ifindex;
609 	}
610 
611 	if (filter_chain_index_set)
612 		addattr32(&req.n, sizeof(req), TCA_CHAIN, chain_index);
613 
614 	if (rtnl_dump_request_n(&rth, &req.n) < 0) {
615 		perror("Cannot send dump request");
616 		return 1;
617 	}
618 
619 	if (rtnl_dump_filter(&rth, print_filter, stdout) < 0) {
620 		fprintf(stderr, "Dump terminated\n");
621 		return 1;
622 	}
623 
624 	return 0;
625 }
626 
do_filter(int argc,char ** argv)627 int do_filter(int argc, char **argv)
628 {
629 	if (argc < 1)
630 		return tc_filter_list(0, NULL);
631 	if (matches(*argv, "add") == 0)
632 		return tc_filter_modify(RTM_NEWTFILTER, NLM_F_EXCL|NLM_F_CREATE,
633 					argc-1, argv+1);
634 	if (matches(*argv, "change") == 0)
635 		return tc_filter_modify(RTM_NEWTFILTER, 0, argc-1, argv+1);
636 	if (matches(*argv, "replace") == 0)
637 		return tc_filter_modify(RTM_NEWTFILTER, NLM_F_CREATE, argc-1,
638 					argv+1);
639 	if (matches(*argv, "delete") == 0)
640 		return tc_filter_modify(RTM_DELTFILTER, 0,  argc-1, argv+1);
641 	if (matches(*argv, "get") == 0)
642 		return tc_filter_get(RTM_GETTFILTER, 0,  argc-1, argv+1);
643 	if (matches(*argv, "list") == 0 || matches(*argv, "show") == 0
644 	    || matches(*argv, "lst") == 0)
645 		return tc_filter_list(argc-1, argv+1);
646 	if (matches(*argv, "help") == 0) {
647 		usage();
648 		return 0;
649 	}
650 	fprintf(stderr, "Command \"%s\" is unknown, try \"tc filter help\".\n",
651 		*argv);
652 	return -1;
653 }
654