iplink.c revision ace9c96121b10ff8f91d79b7486bb8a5520c12df 
1/*
2 * iplink.c		"ip link".
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 <dlfcn.h>
19#include <errno.h>
20#include <sys/socket.h>
21#include <linux/if.h>
22#include <linux/if_packet.h>
23#include <linux/if_ether.h>
24#include <linux/sockios.h>
25#include <netinet/in.h>
26#include <arpa/inet.h>
27#include <string.h>
28#include <sys/ioctl.h>
29#include <linux/sockios.h>
30
31#include "rt_names.h"
32#include "utils.h"
33#include "ip_common.h"
34
35#define IPLINK_IOCTL_COMPAT	1
36#ifndef LIBDIR
37#define LIBDIR "/usr/lib/"
38#endif
39
40static void usage(void) __attribute__((noreturn));
41static int iplink_have_newlink(void);
42
43void iplink_usage(void)
44{
45	if (iplink_have_newlink()) {
46		fprintf(stderr, "Usage: ip link add link DEV [ name ] NAME\n");
47		fprintf(stderr, "                   [ txqueuelen PACKETS ]\n");
48		fprintf(stderr, "                   [ address LLADDR ]\n");
49		fprintf(stderr, "                   [ broadcast LLADDR ]\n");
50		fprintf(stderr, "                   [ mtu MTU ]\n");
51		fprintf(stderr, "                   type TYPE [ ARGS ]\n");
52		fprintf(stderr, "       ip link delete DEV type TYPE [ ARGS ]\n");
53		fprintf(stderr, "\n");
54		fprintf(stderr, "       ip link set DEVICE [ { up | down } ]\n");
55	} else
56		fprintf(stderr, "Usage: ip link set DEVICE [ { up | down } ]\n");
57
58	fprintf(stderr, "	                  [ arp { on | off } ]\n");
59	fprintf(stderr, "	                  [ dynamic { on | off } ]\n");
60	fprintf(stderr, "	                  [ multicast { on | off } ]\n");
61	fprintf(stderr, "	                  [ allmulticast { on | off } ]\n");
62	fprintf(stderr, "	                  [ promisc { on | off } ]\n");
63	fprintf(stderr, "	                  [ trailers { on | off } ]\n");
64	fprintf(stderr, "	                  [ txqueuelen PACKETS ]\n");
65	fprintf(stderr, "	                  [ name NEWNAME ]\n");
66	fprintf(stderr, "	                  [ address LLADDR ]\n");
67	fprintf(stderr, "	                  [ broadcast LLADDR ]\n");
68	fprintf(stderr, "	                  [ mtu MTU ]\n");
69	fprintf(stderr, "	                  [ netns PID ]\n");
70	fprintf(stderr, "			  [ alias NAME ]\n");
71	fprintf(stderr, "       ip link show [ DEVICE ]\n");
72
73	if (iplink_have_newlink()) {
74		fprintf(stderr, "\n");
75		fprintf(stderr, "TYPE := { vlan | veth | dummy | ifb | macvlan }\n");
76	}
77	exit(-1);
78}
79
80static void usage(void)
81{
82	iplink_usage();
83}
84
85static int on_off(char *msg)
86{
87	fprintf(stderr, "Error: argument of \"%s\" must be \"on\" or \"off\"\n", msg);
88	return -1;
89}
90
91static void *BODY;		/* cached dlopen(NULL) handle */
92static struct link_util *linkutil_list;
93
94struct link_util *get_link_kind(const char *id)
95{
96	void *dlh;
97	char buf[256];
98	struct link_util *l;
99
100	for (l = linkutil_list; l; l = l->next)
101		if (strcmp(l->id, id) == 0)
102			return l;
103
104	snprintf(buf, sizeof(buf), LIBDIR "/ip/link_%s.so", id);
105	dlh = dlopen(buf, RTLD_LAZY);
106	if (dlh == NULL) {
107		/* look in current binary, only open once */
108		dlh = BODY;
109		if (dlh == NULL) {
110			dlh = BODY = dlopen(NULL, RTLD_LAZY);
111			if (dlh == NULL)
112				return NULL;
113		}
114	}
115
116	snprintf(buf, sizeof(buf), "%s_link_util", id);
117	l = dlsym(dlh, buf);
118	if (l == NULL)
119		return NULL;
120
121	l->next = linkutil_list;
122	linkutil_list = l;
123	return l;
124}
125
126#if IPLINK_IOCTL_COMPAT
127static int have_rtnl_newlink = -1;
128
129static int accept_msg(const struct sockaddr_nl *who,
130		      struct nlmsghdr *n, void *arg)
131{
132	struct nlmsgerr *err = (struct nlmsgerr *)NLMSG_DATA(n);
133
134	if (n->nlmsg_type == NLMSG_ERROR &&
135	    (err->error == -EOPNOTSUPP || err->error == -EINVAL))
136		have_rtnl_newlink = 0;
137	else
138		have_rtnl_newlink = 1;
139	return -1;
140}
141
142static int iplink_have_newlink(void)
143{
144	struct {
145		struct nlmsghdr		n;
146		struct ifinfomsg	i;
147		char			buf[1024];
148	} req;
149
150	if (have_rtnl_newlink < 0) {
151		memset(&req, 0, sizeof(req));
152
153		req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
154		req.n.nlmsg_flags = NLM_F_REQUEST|NLM_F_ACK;
155		req.n.nlmsg_type = RTM_NEWLINK;
156		req.i.ifi_family = AF_UNSPEC;
157
158		rtnl_send(&rth, (char *)&req.n, req.n.nlmsg_len);
159		rtnl_listen(&rth, accept_msg, NULL);
160	}
161	return have_rtnl_newlink;
162}
163#else /* IPLINK_IOCTL_COMPAT */
164static int iplink_have_newlink(void)
165{
166	return 1;
167}
168#endif /* ! IPLINK_IOCTL_COMPAT */
169
170struct iplink_req {
171	struct nlmsghdr		n;
172	struct ifinfomsg	i;
173	char			buf[1024];
174};
175
176int iplink_parse(int argc, char **argv, struct iplink_req *req,
177		char **name, char **type, char **link, char **dev)
178{
179	int ret, len;
180	char abuf[32];
181	int qlen = -1;
182	int mtu = -1;
183	int netns = -1;
184
185	ret = argc;
186
187	while (argc > 0) {
188		if (strcmp(*argv, "up") == 0) {
189			req->i.ifi_change |= IFF_UP;
190			req->i.ifi_flags |= IFF_UP;
191		} else if (strcmp(*argv, "down") == 0) {
192			req->i.ifi_change |= IFF_UP;
193			req->i.ifi_flags &= ~IFF_UP;
194		} else if (strcmp(*argv, "name") == 0) {
195			NEXT_ARG();
196			*name = *argv;
197		} else if (matches(*argv, "link") == 0) {
198			NEXT_ARG();
199			*link = *argv;
200		} else if (matches(*argv, "address") == 0) {
201			NEXT_ARG();
202			len = ll_addr_a2n(abuf, sizeof(abuf), *argv);
203			addattr_l(&req->n, sizeof(*req), IFLA_ADDRESS, abuf, len);
204		} else if (matches(*argv, "broadcast") == 0 ||
205				strcmp(*argv, "brd") == 0) {
206			NEXT_ARG();
207			len = ll_addr_a2n(abuf, sizeof(abuf), *argv);
208			addattr_l(&req->n, sizeof(*req), IFLA_BROADCAST, abuf, len);
209		} else if (matches(*argv, "txqueuelen") == 0 ||
210				strcmp(*argv, "qlen") == 0 ||
211				matches(*argv, "txqlen") == 0) {
212			NEXT_ARG();
213			if (qlen != -1)
214				duparg("txqueuelen", *argv);
215			if (get_integer(&qlen,  *argv, 0))
216				invarg("Invalid \"txqueuelen\" value\n", *argv);
217			addattr_l(&req->n, sizeof(*req), IFLA_TXQLEN, &qlen, 4);
218		} else if (strcmp(*argv, "mtu") == 0) {
219			NEXT_ARG();
220			if (mtu != -1)
221				duparg("mtu", *argv);
222			if (get_integer(&mtu, *argv, 0))
223				invarg("Invalid \"mtu\" value\n", *argv);
224			addattr_l(&req->n, sizeof(*req), IFLA_MTU, &mtu, 4);
225                } else if (strcmp(*argv, "netns") == 0) {
226                        NEXT_ARG();
227                        if (netns != -1)
228                                duparg("netns", *argv);
229                        if (get_integer(&netns, *argv, 0))
230                                invarg("Invalid \"netns\" value\n", *argv);
231                        addattr_l(&req->n, sizeof(*req), IFLA_NET_NS_PID, &netns, 4);
232		} else if (strcmp(*argv, "multicast") == 0) {
233			NEXT_ARG();
234			req->i.ifi_change |= IFF_MULTICAST;
235			if (strcmp(*argv, "on") == 0) {
236				req->i.ifi_flags |= IFF_MULTICAST;
237			} else if (strcmp(*argv, "off") == 0) {
238				req->i.ifi_flags &= ~IFF_MULTICAST;
239			} else
240				return on_off("multicast");
241		} else if (strcmp(*argv, "allmulticast") == 0) {
242			NEXT_ARG();
243			req->i.ifi_change |= IFF_ALLMULTI;
244			if (strcmp(*argv, "on") == 0) {
245				req->i.ifi_flags |= IFF_ALLMULTI;
246			} else if (strcmp(*argv, "off") == 0) {
247				req->i.ifi_flags &= ~IFF_ALLMULTI;
248			} else
249				return on_off("allmulticast");
250		} else if (strcmp(*argv, "promisc") == 0) {
251			NEXT_ARG();
252			req->i.ifi_change |= IFF_PROMISC;
253			if (strcmp(*argv, "on") == 0) {
254				req->i.ifi_flags |= IFF_PROMISC;
255			} else if (strcmp(*argv, "off") == 0) {
256				req->i.ifi_flags &= ~IFF_PROMISC;
257			} else
258				return on_off("promisc");
259		} else if (strcmp(*argv, "trailers") == 0) {
260			NEXT_ARG();
261			req->i.ifi_change |= IFF_NOTRAILERS;
262			if (strcmp(*argv, "off") == 0) {
263				req->i.ifi_flags |= IFF_NOTRAILERS;
264			} else if (strcmp(*argv, "on") == 0) {
265				req->i.ifi_flags &= ~IFF_NOTRAILERS;
266			} else
267				return on_off("trailers");
268		} else if (strcmp(*argv, "arp") == 0) {
269			NEXT_ARG();
270			req->i.ifi_change |= IFF_NOARP;
271			if (strcmp(*argv, "on") == 0) {
272				req->i.ifi_flags &= ~IFF_NOARP;
273			} else if (strcmp(*argv, "off") == 0) {
274				req->i.ifi_flags |= IFF_NOARP;
275			} else
276				return on_off("noarp");
277#ifdef IFF_DYNAMIC
278		} else if (matches(*argv, "dynamic") == 0) {
279			NEXT_ARG();
280			req->i.ifi_change |= IFF_DYNAMIC;
281			if (strcmp(*argv, "on") == 0) {
282				req->i.ifi_flags |= IFF_DYNAMIC;
283			} else if (strcmp(*argv, "off") == 0) {
284				req->i.ifi_flags &= ~IFF_DYNAMIC;
285			} else
286				return on_off("dynamic");
287#endif
288		} else if (matches(*argv, "type") == 0) {
289			NEXT_ARG();
290			*type = *argv;
291			argc--; argv++;
292			break;
293		} else if (matches(*argv, "alias") == 0) {
294			NEXT_ARG();
295			addattr_l(&req->n, sizeof(*req), IFLA_IFALIAS,
296				  *argv, strlen(*argv));
297			argc--; argv++;
298			break;
299		} else {
300			if (strcmp(*argv, "dev") == 0) {
301				NEXT_ARG();
302			}
303			if (matches(*argv, "help") == 0)
304				usage();
305			if (*dev)
306				duparg2("dev", *argv);
307			*dev = *argv;
308		}
309		argc--; argv++;
310	}
311
312	return ret - argc;
313}
314
315static int iplink_modify(int cmd, unsigned int flags, int argc, char **argv)
316{
317	int len;
318	char *dev = NULL;
319	char *name = NULL;
320	char *link = NULL;
321	char *type = NULL;
322	struct link_util *lu = NULL;
323	struct iplink_req req;
324	int ret;
325
326	memset(&req, 0, sizeof(req));
327
328	req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
329	req.n.nlmsg_flags = NLM_F_REQUEST|flags;
330	req.n.nlmsg_type = cmd;
331	req.i.ifi_family = preferred_family;
332
333	ret = iplink_parse(argc, argv, &req, &name, &type, &link, &dev);
334	if (ret < 0)
335		return ret;
336
337	argc -= ret;
338	argv += ret;
339	ll_init_map(&rth);
340
341	if (type) {
342		struct rtattr *linkinfo = NLMSG_TAIL(&req.n);
343		addattr_l(&req.n, sizeof(req), IFLA_LINKINFO, NULL, 0);
344		addattr_l(&req.n, sizeof(req), IFLA_INFO_KIND, type,
345			 strlen(type));
346
347		lu = get_link_kind(type);
348		if (lu && argc) {
349			struct rtattr * data = NLMSG_TAIL(&req.n);
350			addattr_l(&req.n, sizeof(req), IFLA_INFO_DATA, NULL, 0);
351
352			if (lu->parse_opt &&
353			    lu->parse_opt(lu, argc, argv, &req.n))
354				return -1;
355
356			data->rta_len = (void *)NLMSG_TAIL(&req.n) - (void *)data;
357		} else if (argc) {
358			if (matches(*argv, "help") == 0)
359				usage();
360			fprintf(stderr, "Garbage instead of arguments \"%s ...\". "
361					"Try \"ip link help\".\n", *argv);
362			return -1;
363		}
364		linkinfo->rta_len = (void *)NLMSG_TAIL(&req.n) - (void *)linkinfo;
365	} else if (flags & NLM_F_CREATE) {
366		fprintf(stderr, "Not enough information: \"type\" argument "
367				"is required\n");
368		return -1;
369	}
370
371	if (!(flags & NLM_F_CREATE)) {
372		if (!dev) {
373			fprintf(stderr, "Not enough information: \"dev\" "
374					"argument is required.\n");
375			exit(-1);
376		}
377
378		req.i.ifi_index = ll_name_to_index(dev);
379		if (req.i.ifi_index == 0) {
380			fprintf(stderr, "Cannot find device \"%s\"\n", dev);
381			return -1;
382		}
383	} else {
384		/* Allow "ip link add dev" and "ip link add name" */
385		if (!name)
386			name = dev;
387
388		if (link) {
389			int ifindex;
390
391			ifindex = ll_name_to_index(link);
392			if (ifindex == 0) {
393				fprintf(stderr, "Cannot find device \"%s\"\n",
394					link);
395				return -1;
396			}
397			addattr_l(&req.n, sizeof(req), IFLA_LINK, &ifindex, 4);
398		}
399	}
400
401	if (name) {
402		len = strlen(name) + 1;
403		if (len == 1)
404			invarg("\"\" is not a valid device identifier\n", "name");
405		if (len > IFNAMSIZ)
406			invarg("\"name\" too long\n", name);
407		addattr_l(&req.n, sizeof(req), IFLA_IFNAME, name, len);
408	}
409
410	if (rtnl_talk(&rth, &req.n, 0, 0, NULL, NULL, NULL) < 0)
411		exit(2);
412
413	return 0;
414}
415
416#if IPLINK_IOCTL_COMPAT
417static int get_ctl_fd(void)
418{
419	int s_errno;
420	int fd;
421
422	fd = socket(PF_INET, SOCK_DGRAM, 0);
423	if (fd >= 0)
424		return fd;
425	s_errno = errno;
426	fd = socket(PF_PACKET, SOCK_DGRAM, 0);
427	if (fd >= 0)
428		return fd;
429	fd = socket(PF_INET6, SOCK_DGRAM, 0);
430	if (fd >= 0)
431		return fd;
432	errno = s_errno;
433	perror("Cannot create control socket");
434	return -1;
435}
436
437static int do_chflags(const char *dev, __u32 flags, __u32 mask)
438{
439	struct ifreq ifr;
440	int fd;
441	int err;
442
443	strncpy(ifr.ifr_name, dev, IFNAMSIZ);
444	fd = get_ctl_fd();
445	if (fd < 0)
446		return -1;
447	err = ioctl(fd, SIOCGIFFLAGS, &ifr);
448	if (err) {
449		perror("SIOCGIFFLAGS");
450		close(fd);
451		return -1;
452	}
453	if ((ifr.ifr_flags^flags)&mask) {
454		ifr.ifr_flags &= ~mask;
455		ifr.ifr_flags |= mask&flags;
456		err = ioctl(fd, SIOCSIFFLAGS, &ifr);
457		if (err)
458			perror("SIOCSIFFLAGS");
459	}
460	close(fd);
461	return err;
462}
463
464static int do_changename(const char *dev, const char *newdev)
465{
466	struct ifreq ifr;
467	int fd;
468	int err;
469
470	strncpy(ifr.ifr_name, dev, IFNAMSIZ);
471	strncpy(ifr.ifr_newname, newdev, IFNAMSIZ);
472	fd = get_ctl_fd();
473	if (fd < 0)
474		return -1;
475	err = ioctl(fd, SIOCSIFNAME, &ifr);
476	if (err) {
477		perror("SIOCSIFNAME");
478		close(fd);
479		return -1;
480	}
481	close(fd);
482	return err;
483}
484
485static int set_qlen(const char *dev, int qlen)
486{
487	struct ifreq ifr;
488	int s;
489
490	s = get_ctl_fd();
491	if (s < 0)
492		return -1;
493
494	memset(&ifr, 0, sizeof(ifr));
495	strncpy(ifr.ifr_name, dev, IFNAMSIZ);
496	ifr.ifr_qlen = qlen;
497	if (ioctl(s, SIOCSIFTXQLEN, &ifr) < 0) {
498		perror("SIOCSIFXQLEN");
499		close(s);
500		return -1;
501	}
502	close(s);
503
504	return 0;
505}
506
507static int set_mtu(const char *dev, int mtu)
508{
509	struct ifreq ifr;
510	int s;
511
512	s = get_ctl_fd();
513	if (s < 0)
514		return -1;
515
516	memset(&ifr, 0, sizeof(ifr));
517	strncpy(ifr.ifr_name, dev, IFNAMSIZ);
518	ifr.ifr_mtu = mtu;
519	if (ioctl(s, SIOCSIFMTU, &ifr) < 0) {
520		perror("SIOCSIFMTU");
521		close(s);
522		return -1;
523	}
524	close(s);
525
526	return 0;
527}
528
529static int get_address(const char *dev, int *htype)
530{
531	struct ifreq ifr;
532	struct sockaddr_ll me;
533	socklen_t alen;
534	int s;
535
536	s = socket(PF_PACKET, SOCK_DGRAM, 0);
537	if (s < 0) {
538		perror("socket(PF_PACKET)");
539		return -1;
540	}
541
542	memset(&ifr, 0, sizeof(ifr));
543	strncpy(ifr.ifr_name, dev, IFNAMSIZ);
544	if (ioctl(s, SIOCGIFINDEX, &ifr) < 0) {
545		perror("SIOCGIFINDEX");
546		close(s);
547		return -1;
548	}
549
550	memset(&me, 0, sizeof(me));
551	me.sll_family = AF_PACKET;
552	me.sll_ifindex = ifr.ifr_ifindex;
553	me.sll_protocol = htons(ETH_P_LOOP);
554	if (bind(s, (struct sockaddr*)&me, sizeof(me)) == -1) {
555		perror("bind");
556		close(s);
557		return -1;
558	}
559
560	alen = sizeof(me);
561	if (getsockname(s, (struct sockaddr*)&me, &alen) == -1) {
562		perror("getsockname");
563		close(s);
564		return -1;
565	}
566	close(s);
567	*htype = me.sll_hatype;
568	return me.sll_halen;
569}
570
571static int parse_address(const char *dev, int hatype, int halen,
572		char *lla, struct ifreq *ifr)
573{
574	int alen;
575
576	memset(ifr, 0, sizeof(*ifr));
577	strncpy(ifr->ifr_name, dev, IFNAMSIZ);
578	ifr->ifr_hwaddr.sa_family = hatype;
579	alen = ll_addr_a2n(ifr->ifr_hwaddr.sa_data, 14, lla);
580	if (alen < 0)
581		return -1;
582	if (alen != halen) {
583		fprintf(stderr, "Wrong address (%s) length: expected %d bytes\n", lla, halen);
584		return -1;
585	}
586	return 0;
587}
588
589static int set_address(struct ifreq *ifr, int brd)
590{
591	int s;
592
593	s = get_ctl_fd();
594	if (s < 0)
595		return -1;
596	if (ioctl(s, brd?SIOCSIFHWBROADCAST:SIOCSIFHWADDR, ifr) < 0) {
597		perror(brd?"SIOCSIFHWBROADCAST":"SIOCSIFHWADDR");
598		close(s);
599		return -1;
600	}
601	close(s);
602	return 0;
603}
604
605
606static int do_set(int argc, char **argv)
607{
608	char *dev = NULL;
609	__u32 mask = 0;
610	__u32 flags = 0;
611	int qlen = -1;
612	int mtu = -1;
613	char *newaddr = NULL;
614	char *newbrd = NULL;
615	struct ifreq ifr0, ifr1;
616	char *newname = NULL;
617	int htype, halen;
618
619	while (argc > 0) {
620		if (strcmp(*argv, "up") == 0) {
621			mask |= IFF_UP;
622			flags |= IFF_UP;
623		} else if (strcmp(*argv, "down") == 0) {
624			mask |= IFF_UP;
625			flags &= ~IFF_UP;
626		} else if (strcmp(*argv, "name") == 0) {
627			NEXT_ARG();
628			newname = *argv;
629		} else if (matches(*argv, "address") == 0) {
630			NEXT_ARG();
631			newaddr = *argv;
632		} else if (matches(*argv, "broadcast") == 0 ||
633			   strcmp(*argv, "brd") == 0) {
634			NEXT_ARG();
635			newbrd = *argv;
636		} else if (matches(*argv, "txqueuelen") == 0 ||
637			   strcmp(*argv, "qlen") == 0 ||
638			   matches(*argv, "txqlen") == 0) {
639			NEXT_ARG();
640			if (qlen != -1)
641				duparg("txqueuelen", *argv);
642			if (get_integer(&qlen,  *argv, 0))
643				invarg("Invalid \"txqueuelen\" value\n", *argv);
644		} else if (strcmp(*argv, "mtu") == 0) {
645			NEXT_ARG();
646			if (mtu != -1)
647				duparg("mtu", *argv);
648			if (get_integer(&mtu, *argv, 0))
649				invarg("Invalid \"mtu\" value\n", *argv);
650		} else if (strcmp(*argv, "multicast") == 0) {
651			NEXT_ARG();
652			mask |= IFF_MULTICAST;
653			if (strcmp(*argv, "on") == 0) {
654				flags |= IFF_MULTICAST;
655			} else if (strcmp(*argv, "off") == 0) {
656				flags &= ~IFF_MULTICAST;
657			} else
658				return on_off("multicast");
659		} else if (strcmp(*argv, "allmulticast") == 0) {
660			NEXT_ARG();
661			mask |= IFF_ALLMULTI;
662			if (strcmp(*argv, "on") == 0) {
663				flags |= IFF_ALLMULTI;
664			} else if (strcmp(*argv, "off") == 0) {
665				flags &= ~IFF_ALLMULTI;
666			} else
667				return on_off("allmulticast");
668		} else if (strcmp(*argv, "promisc") == 0) {
669			NEXT_ARG();
670			mask |= IFF_PROMISC;
671			if (strcmp(*argv, "on") == 0) {
672				flags |= IFF_PROMISC;
673			} else if (strcmp(*argv, "off") == 0) {
674				flags &= ~IFF_PROMISC;
675			} else
676				return on_off("promisc");
677		} else if (strcmp(*argv, "trailers") == 0) {
678			NEXT_ARG();
679			mask |= IFF_NOTRAILERS;
680			if (strcmp(*argv, "off") == 0) {
681				flags |= IFF_NOTRAILERS;
682			} else if (strcmp(*argv, "on") == 0) {
683				flags &= ~IFF_NOTRAILERS;
684			} else
685				return on_off("trailers");
686		} else if (strcmp(*argv, "arp") == 0) {
687			NEXT_ARG();
688			mask |= IFF_NOARP;
689			if (strcmp(*argv, "on") == 0) {
690				flags &= ~IFF_NOARP;
691			} else if (strcmp(*argv, "off") == 0) {
692				flags |= IFF_NOARP;
693			} else
694				return on_off("noarp");
695#ifdef IFF_DYNAMIC
696		} else if (matches(*argv, "dynamic") == 0) {
697			NEXT_ARG();
698			mask |= IFF_DYNAMIC;
699			if (strcmp(*argv, "on") == 0) {
700				flags |= IFF_DYNAMIC;
701			} else if (strcmp(*argv, "off") == 0) {
702				flags &= ~IFF_DYNAMIC;
703			} else
704				return on_off("dynamic");
705#endif
706		} else {
707                        if (strcmp(*argv, "dev") == 0) {
708				NEXT_ARG();
709			}
710			if (matches(*argv, "help") == 0)
711				usage();
712			if (dev)
713				duparg2("dev", *argv);
714			dev = *argv;
715		}
716		argc--; argv++;
717	}
718
719	if (!dev) {
720		fprintf(stderr, "Not enough of information: \"dev\" argument is required.\n");
721		exit(-1);
722	}
723
724	if (newaddr || newbrd) {
725		halen = get_address(dev, &htype);
726		if (halen < 0)
727			return -1;
728		if (newaddr) {
729			if (parse_address(dev, htype, halen, newaddr, &ifr0) < 0)
730				return -1;
731		}
732		if (newbrd) {
733			if (parse_address(dev, htype, halen, newbrd, &ifr1) < 0)
734				return -1;
735		}
736	}
737
738	if (newname && strcmp(dev, newname)) {
739		if (strlen(newname) == 0)
740			invarg("\"\" is not a valid device identifier\n", "name");
741		if (do_changename(dev, newname) < 0)
742			return -1;
743		dev = newname;
744	}
745	if (qlen != -1) {
746		if (set_qlen(dev, qlen) < 0)
747			return -1;
748	}
749	if (mtu != -1) {
750		if (set_mtu(dev, mtu) < 0)
751			return -1;
752	}
753	if (newaddr || newbrd) {
754		if (newbrd) {
755			if (set_address(&ifr1, 1) < 0)
756				return -1;
757		}
758		if (newaddr) {
759			if (set_address(&ifr0, 0) < 0)
760				return -1;
761		}
762	}
763	if (mask)
764		return do_chflags(dev, flags, mask);
765	return 0;
766}
767#endif /* IPLINK_IOCTL_COMPAT */
768
769int do_iplink(int argc, char **argv)
770{
771	if (argc > 0) {
772		if (iplink_have_newlink()) {
773			if (matches(*argv, "add") == 0)
774				return iplink_modify(RTM_NEWLINK,
775						     NLM_F_CREATE|NLM_F_EXCL,
776						     argc-1, argv+1);
777			if (matches(*argv, "set") == 0 ||
778			    matches(*argv, "change") == 0)
779				return iplink_modify(RTM_NEWLINK, 0,
780						     argc-1, argv+1);
781			if (matches(*argv, "replace") == 0)
782				return iplink_modify(RTM_NEWLINK,
783						     NLM_F_CREATE|NLM_F_REPLACE,
784						     argc-1, argv+1);
785			if (matches(*argv, "delete") == 0)
786				return iplink_modify(RTM_DELLINK, 0,
787						     argc-1, argv+1);
788		} else {
789#if IPLINK_IOCTL_COMPAT
790			if (matches(*argv, "set") == 0)
791				return do_set(argc-1, argv+1);
792#endif
793		}
794		if (matches(*argv, "show") == 0 ||
795		    matches(*argv, "lst") == 0 ||
796		    matches(*argv, "list") == 0)
797			return ipaddr_list_link(argc-1, argv+1);
798		if (matches(*argv, "help") == 0)
799			usage();
800	} else
801		return ipaddr_list_link(0, NULL);
802
803	fprintf(stderr, "Command \"%s\" is unknown, try \"ip link help\".\n", *argv);
804	exit(-1);
805}
806