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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 
40 static void usage(void) __attribute__((noreturn));
41 static int iplink_have_newlink(void);
42 
iplink_usage(void)43 void 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, "	                  [ vf NUM [ mac LLADDR ]\n");
72 	fprintf(stderr, "				   [ vlan VLANID [ qos VLAN-QOS ] ]\n");
73 	fprintf(stderr, "				   [ rate TXRATE ] ] \n");
74 	fprintf(stderr, "       ip link show [ DEVICE ]\n");
75 
76 	if (iplink_have_newlink()) {
77 		fprintf(stderr, "\n");
78 		fprintf(stderr, "TYPE := { vlan | veth | vcan | dummy | ifb | macvlan | can }\n");
79 	}
80 	exit(-1);
81 }
82 
usage(void)83 static void usage(void)
84 {
85 	iplink_usage();
86 }
87 
on_off(char * msg)88 static int on_off(char *msg)
89 {
90 	fprintf(stderr, "Error: argument of \"%s\" must be \"on\" or \"off\"\n", msg);
91 	return -1;
92 }
93 
94 static void *BODY;		/* cached dlopen(NULL) handle */
95 static struct link_util *linkutil_list;
96 
get_link_kind(const char * id)97 struct link_util *get_link_kind(const char *id)
98 {
99 	void *dlh;
100 	char buf[256];
101 	struct link_util *l;
102 
103 	for (l = linkutil_list; l; l = l->next)
104 		if (strcmp(l->id, id) == 0)
105 			return l;
106 
107 	snprintf(buf, sizeof(buf), LIBDIR "/ip/link_%s.so", id);
108 	dlh = dlopen(buf, RTLD_LAZY);
109 	if (dlh == NULL) {
110 		/* look in current binary, only open once */
111 		dlh = BODY;
112 		if (dlh == NULL) {
113 			dlh = BODY = dlopen(NULL, RTLD_LAZY);
114 			if (dlh == NULL)
115 				return NULL;
116 		}
117 	}
118 
119 	snprintf(buf, sizeof(buf), "%s_link_util", id);
120 	l = dlsym(dlh, buf);
121 	if (l == NULL)
122 		return NULL;
123 
124 	l->next = linkutil_list;
125 	linkutil_list = l;
126 	return l;
127 }
128 
129 #if IPLINK_IOCTL_COMPAT
130 static int have_rtnl_newlink = -1;
131 
accept_msg(const struct sockaddr_nl * who,struct nlmsghdr * n,void * arg)132 static int accept_msg(const struct sockaddr_nl *who,
133 		      struct nlmsghdr *n, void *arg)
134 {
135 	struct nlmsgerr *err = (struct nlmsgerr *)NLMSG_DATA(n);
136 
137 	if (n->nlmsg_type == NLMSG_ERROR &&
138 	    (err->error == -EOPNOTSUPP || err->error == -EINVAL))
139 		have_rtnl_newlink = 0;
140 	else
141 		have_rtnl_newlink = 1;
142 	return -1;
143 }
144 
iplink_have_newlink(void)145 static int iplink_have_newlink(void)
146 {
147 	struct {
148 		struct nlmsghdr		n;
149 		struct ifinfomsg	i;
150 		char			buf[1024];
151 	} req;
152 
153 	if (have_rtnl_newlink < 0) {
154 		memset(&req, 0, sizeof(req));
155 
156 		req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
157 		req.n.nlmsg_flags = NLM_F_REQUEST|NLM_F_ACK;
158 		req.n.nlmsg_type = RTM_NEWLINK;
159 		req.i.ifi_family = AF_UNSPEC;
160 
161 		rtnl_send(&rth, (char *)&req.n, req.n.nlmsg_len);
162 		rtnl_listen(&rth, accept_msg, NULL);
163 	}
164 	return have_rtnl_newlink;
165 }
166 #else /* IPLINK_IOCTL_COMPAT */
iplink_have_newlink(void)167 static int iplink_have_newlink(void)
168 {
169 	return 1;
170 }
171 #endif /* ! IPLINK_IOCTL_COMPAT */
172 
173 struct iplink_req {
174 	struct nlmsghdr		n;
175 	struct ifinfomsg	i;
176 	char			buf[1024];
177 };
178 
iplink_parse_vf(int vf,int * argcp,char *** argvp,struct iplink_req * req)179 int iplink_parse_vf(int vf, int *argcp, char ***argvp,
180 			   struct iplink_req *req)
181 {
182 	int len, argc = *argcp;
183 	char **argv = *argvp;
184 	struct rtattr *vfinfo;
185 
186 	vfinfo = addattr_nest(&req->n, sizeof(*req), IFLA_VF_INFO);
187 
188 	while (NEXT_ARG_OK()) {
189 		NEXT_ARG();
190 		if (matches(*argv, "mac") == 0) {
191 			struct ifla_vf_mac ivm;
192 			NEXT_ARG();
193 			ivm.vf = vf;
194 			len = ll_addr_a2n((char *)ivm.mac, 32, *argv);
195 			if (len < 0)
196 				return -1;
197 			addattr_l(&req->n, sizeof(*req), IFLA_VF_MAC, &ivm, sizeof(ivm));
198 		} else if (matches(*argv, "vlan") == 0) {
199 			struct ifla_vf_vlan ivv;
200 			NEXT_ARG();
201 			if (get_unsigned(&ivv.vlan, *argv, 0)) {
202 				invarg("Invalid \"vlan\" value\n", *argv);
203 			}
204 			ivv.vf = vf;
205 			ivv.qos = 0;
206 			if (NEXT_ARG_OK()) {
207 				NEXT_ARG();
208 				if (matches(*argv, "qos") == 0) {
209 					NEXT_ARG();
210 					if (get_unsigned(&ivv.qos, *argv, 0)) {
211 						invarg("Invalid \"qos\" value\n", *argv);
212 					}
213 				} else {
214 					/* rewind arg */
215 					PREV_ARG();
216 				}
217 			}
218 			addattr_l(&req->n, sizeof(*req), IFLA_VF_VLAN, &ivv, sizeof(ivv));
219 		} else if (matches(*argv, "rate") == 0) {
220 			struct ifla_vf_tx_rate ivt;
221 			NEXT_ARG();
222 			if (get_unsigned(&ivt.rate, *argv, 0)) {
223 				invarg("Invalid \"rate\" value\n", *argv);
224 			}
225 			ivt.vf = vf;
226 			addattr_l(&req->n, sizeof(*req), IFLA_VF_TX_RATE, &ivt, sizeof(ivt));
227 
228 		} else {
229 			/* rewind arg */
230 			PREV_ARG();
231 			break;
232 		}
233 	}
234 
235 	if (argc == *argcp)
236 		incomplete_command();
237 
238 	addattr_nest_end(&req->n, vfinfo);
239 
240 	*argcp = argc;
241 	*argvp = argv;
242 	return 0;
243 }
244 
245 
iplink_parse(int argc,char ** argv,struct iplink_req * req,char ** name,char ** type,char ** link,char ** dev)246 int iplink_parse(int argc, char **argv, struct iplink_req *req,
247 		char **name, char **type, char **link, char **dev)
248 {
249 	int ret, len;
250 	char abuf[32];
251 	int qlen = -1;
252 	int mtu = -1;
253 	int netns = -1;
254 	int vf = -1;
255 
256 	ret = argc;
257 
258 	while (argc > 0) {
259 		if (strcmp(*argv, "up") == 0) {
260 			req->i.ifi_change |= IFF_UP;
261 			req->i.ifi_flags |= IFF_UP;
262 		} else if (strcmp(*argv, "down") == 0) {
263 			req->i.ifi_change |= IFF_UP;
264 			req->i.ifi_flags &= ~IFF_UP;
265 		} else if (strcmp(*argv, "name") == 0) {
266 			NEXT_ARG();
267 			*name = *argv;
268 		} else if (matches(*argv, "link") == 0) {
269 			NEXT_ARG();
270 			*link = *argv;
271 		} else if (matches(*argv, "address") == 0) {
272 			NEXT_ARG();
273 			len = ll_addr_a2n(abuf, sizeof(abuf), *argv);
274 			if (len < 0)
275 				return -1;
276 			addattr_l(&req->n, sizeof(*req), IFLA_ADDRESS, abuf, len);
277 		} else if (matches(*argv, "broadcast") == 0 ||
278 				strcmp(*argv, "brd") == 0) {
279 			NEXT_ARG();
280 			len = ll_addr_a2n(abuf, sizeof(abuf), *argv);
281 			if (len < 0)
282 				return -1;
283 			addattr_l(&req->n, sizeof(*req), IFLA_BROADCAST, abuf, len);
284 		} else if (matches(*argv, "txqueuelen") == 0 ||
285 				strcmp(*argv, "qlen") == 0 ||
286 				matches(*argv, "txqlen") == 0) {
287 			NEXT_ARG();
288 			if (qlen != -1)
289 				duparg("txqueuelen", *argv);
290 			if (get_integer(&qlen,  *argv, 0))
291 				invarg("Invalid \"txqueuelen\" value\n", *argv);
292 			addattr_l(&req->n, sizeof(*req), IFLA_TXQLEN, &qlen, 4);
293 		} else if (strcmp(*argv, "mtu") == 0) {
294 			NEXT_ARG();
295 			if (mtu != -1)
296 				duparg("mtu", *argv);
297 			if (get_integer(&mtu, *argv, 0))
298 				invarg("Invalid \"mtu\" value\n", *argv);
299 			addattr_l(&req->n, sizeof(*req), IFLA_MTU, &mtu, 4);
300                 } else if (strcmp(*argv, "netns") == 0) {
301                         NEXT_ARG();
302                         if (netns != -1)
303                                 duparg("netns", *argv);
304                         if (get_integer(&netns, *argv, 0))
305                                 invarg("Invalid \"netns\" value\n", *argv);
306                         addattr_l(&req->n, sizeof(*req), IFLA_NET_NS_PID, &netns, 4);
307 		} else if (strcmp(*argv, "multicast") == 0) {
308 			NEXT_ARG();
309 			req->i.ifi_change |= IFF_MULTICAST;
310 			if (strcmp(*argv, "on") == 0) {
311 				req->i.ifi_flags |= IFF_MULTICAST;
312 			} else if (strcmp(*argv, "off") == 0) {
313 				req->i.ifi_flags &= ~IFF_MULTICAST;
314 			} else
315 				return on_off("multicast");
316 		} else if (strcmp(*argv, "allmulticast") == 0) {
317 			NEXT_ARG();
318 			req->i.ifi_change |= IFF_ALLMULTI;
319 			if (strcmp(*argv, "on") == 0) {
320 				req->i.ifi_flags |= IFF_ALLMULTI;
321 			} else if (strcmp(*argv, "off") == 0) {
322 				req->i.ifi_flags &= ~IFF_ALLMULTI;
323 			} else
324 				return on_off("allmulticast");
325 		} else if (strcmp(*argv, "promisc") == 0) {
326 			NEXT_ARG();
327 			req->i.ifi_change |= IFF_PROMISC;
328 			if (strcmp(*argv, "on") == 0) {
329 				req->i.ifi_flags |= IFF_PROMISC;
330 			} else if (strcmp(*argv, "off") == 0) {
331 				req->i.ifi_flags &= ~IFF_PROMISC;
332 			} else
333 				return on_off("promisc");
334 		} else if (strcmp(*argv, "trailers") == 0) {
335 			NEXT_ARG();
336 			req->i.ifi_change |= IFF_NOTRAILERS;
337 			if (strcmp(*argv, "off") == 0) {
338 				req->i.ifi_flags |= IFF_NOTRAILERS;
339 			} else if (strcmp(*argv, "on") == 0) {
340 				req->i.ifi_flags &= ~IFF_NOTRAILERS;
341 			} else
342 				return on_off("trailers");
343 		} else if (strcmp(*argv, "arp") == 0) {
344 			NEXT_ARG();
345 			req->i.ifi_change |= IFF_NOARP;
346 			if (strcmp(*argv, "on") == 0) {
347 				req->i.ifi_flags &= ~IFF_NOARP;
348 			} else if (strcmp(*argv, "off") == 0) {
349 				req->i.ifi_flags |= IFF_NOARP;
350 			} else
351 				return on_off("noarp");
352 		} else if (strcmp(*argv, "vf") == 0) {
353 			struct rtattr *vflist;
354 			NEXT_ARG();
355 			if (get_integer(&vf,  *argv, 0)) {
356 				invarg("Invalid \"vf\" value\n", *argv);
357 			}
358 			vflist = addattr_nest(&req->n, sizeof(*req),
359 					      IFLA_VFINFO_LIST);
360 			len = iplink_parse_vf(vf, &argc, &argv, req);
361 			if (len < 0)
362 				return -1;
363 			addattr_nest_end(&req->n, vflist);
364 #ifdef IFF_DYNAMIC
365 		} else if (matches(*argv, "dynamic") == 0) {
366 			NEXT_ARG();
367 			req->i.ifi_change |= IFF_DYNAMIC;
368 			if (strcmp(*argv, "on") == 0) {
369 				req->i.ifi_flags |= IFF_DYNAMIC;
370 			} else if (strcmp(*argv, "off") == 0) {
371 				req->i.ifi_flags &= ~IFF_DYNAMIC;
372 			} else
373 				return on_off("dynamic");
374 #endif
375 		} else if (matches(*argv, "type") == 0) {
376 			NEXT_ARG();
377 			*type = *argv;
378 			argc--; argv++;
379 			break;
380 		} else if (matches(*argv, "alias") == 0) {
381 			NEXT_ARG();
382 			addattr_l(&req->n, sizeof(*req), IFLA_IFALIAS,
383 				  *argv, strlen(*argv));
384 			argc--; argv++;
385 			break;
386 		} else {
387 			if (strcmp(*argv, "dev") == 0) {
388 				NEXT_ARG();
389 			}
390 			if (matches(*argv, "help") == 0)
391 				usage();
392 			if (*dev)
393 				duparg2("dev", *argv);
394 			*dev = *argv;
395 		}
396 		argc--; argv++;
397 	}
398 
399 	return ret - argc;
400 }
401 
iplink_modify(int cmd,unsigned int flags,int argc,char ** argv)402 static int iplink_modify(int cmd, unsigned int flags, int argc, char **argv)
403 {
404 	int len;
405 	char *dev = NULL;
406 	char *name = NULL;
407 	char *link = NULL;
408 	char *type = NULL;
409 	struct link_util *lu = NULL;
410 	struct iplink_req req;
411 	int ret;
412 
413 	memset(&req, 0, sizeof(req));
414 
415 	req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
416 	req.n.nlmsg_flags = NLM_F_REQUEST|flags;
417 	req.n.nlmsg_type = cmd;
418 	req.i.ifi_family = preferred_family;
419 
420 	ret = iplink_parse(argc, argv, &req, &name, &type, &link, &dev);
421 	if (ret < 0)
422 		return ret;
423 
424 	argc -= ret;
425 	argv += ret;
426 	ll_init_map(&rth);
427 
428 	if (type) {
429 		struct rtattr *linkinfo = NLMSG_TAIL(&req.n);
430 		addattr_l(&req.n, sizeof(req), IFLA_LINKINFO, NULL, 0);
431 		addattr_l(&req.n, sizeof(req), IFLA_INFO_KIND, type,
432 			 strlen(type));
433 
434 		lu = get_link_kind(type);
435 		if (lu && argc) {
436 			struct rtattr * data = NLMSG_TAIL(&req.n);
437 			addattr_l(&req.n, sizeof(req), IFLA_INFO_DATA, NULL, 0);
438 
439 			if (lu->parse_opt &&
440 			    lu->parse_opt(lu, argc, argv, &req.n))
441 				return -1;
442 
443 			data->rta_len = (void *)NLMSG_TAIL(&req.n) - (void *)data;
444 		} else if (argc) {
445 			if (matches(*argv, "help") == 0)
446 				usage();
447 			fprintf(stderr, "Garbage instead of arguments \"%s ...\". "
448 					"Try \"ip link help\".\n", *argv);
449 			return -1;
450 		}
451 		linkinfo->rta_len = (void *)NLMSG_TAIL(&req.n) - (void *)linkinfo;
452 	} else if (flags & NLM_F_CREATE) {
453 		fprintf(stderr, "Not enough information: \"type\" argument "
454 				"is required\n");
455 		return -1;
456 	}
457 
458 	if (!(flags & NLM_F_CREATE)) {
459 		if (!dev) {
460 			fprintf(stderr, "Not enough information: \"dev\" "
461 					"argument is required.\n");
462 			exit(-1);
463 		}
464 
465 		req.i.ifi_index = ll_name_to_index(dev);
466 		if (req.i.ifi_index == 0) {
467 			fprintf(stderr, "Cannot find device \"%s\"\n", dev);
468 			return -1;
469 		}
470 	} else {
471 		/* Allow "ip link add dev" and "ip link add name" */
472 		if (!name)
473 			name = dev;
474 
475 		if (link) {
476 			int ifindex;
477 
478 			ifindex = ll_name_to_index(link);
479 			if (ifindex == 0) {
480 				fprintf(stderr, "Cannot find device \"%s\"\n",
481 					link);
482 				return -1;
483 			}
484 			addattr_l(&req.n, sizeof(req), IFLA_LINK, &ifindex, 4);
485 		}
486 	}
487 
488 	if (name) {
489 		len = strlen(name) + 1;
490 		if (len == 1)
491 			invarg("\"\" is not a valid device identifier\n", "name");
492 		if (len > IFNAMSIZ)
493 			invarg("\"name\" too long\n", name);
494 		addattr_l(&req.n, sizeof(req), IFLA_IFNAME, name, len);
495 	}
496 
497 	if (rtnl_talk(&rth, &req.n, 0, 0, NULL, NULL, NULL) < 0)
498 		exit(2);
499 
500 	return 0;
501 }
502 
503 #if IPLINK_IOCTL_COMPAT
get_ctl_fd(void)504 static int get_ctl_fd(void)
505 {
506 	int s_errno;
507 	int fd;
508 
509 	fd = socket(PF_INET, SOCK_DGRAM, 0);
510 	if (fd >= 0)
511 		return fd;
512 	s_errno = errno;
513 	fd = socket(PF_PACKET, SOCK_DGRAM, 0);
514 	if (fd >= 0)
515 		return fd;
516 	fd = socket(PF_INET6, SOCK_DGRAM, 0);
517 	if (fd >= 0)
518 		return fd;
519 	errno = s_errno;
520 	perror("Cannot create control socket");
521 	return -1;
522 }
523 
do_chflags(const char * dev,__u32 flags,__u32 mask)524 static int do_chflags(const char *dev, __u32 flags, __u32 mask)
525 {
526 	struct ifreq ifr;
527 	int fd;
528 	int err;
529 
530 	strncpy(ifr.ifr_name, dev, IFNAMSIZ);
531 	fd = get_ctl_fd();
532 	if (fd < 0)
533 		return -1;
534 	err = ioctl(fd, SIOCGIFFLAGS, &ifr);
535 	if (err) {
536 		perror("SIOCGIFFLAGS");
537 		close(fd);
538 		return -1;
539 	}
540 	if ((ifr.ifr_flags^flags)&mask) {
541 		ifr.ifr_flags &= ~mask;
542 		ifr.ifr_flags |= mask&flags;
543 		err = ioctl(fd, SIOCSIFFLAGS, &ifr);
544 		if (err)
545 			perror("SIOCSIFFLAGS");
546 	}
547 	close(fd);
548 	return err;
549 }
550 
do_changename(const char * dev,const char * newdev)551 static int do_changename(const char *dev, const char *newdev)
552 {
553 	struct ifreq ifr;
554 	int fd;
555 	int err;
556 
557 	strncpy(ifr.ifr_name, dev, IFNAMSIZ);
558 	strncpy(ifr.ifr_newname, newdev, IFNAMSIZ);
559 	fd = get_ctl_fd();
560 	if (fd < 0)
561 		return -1;
562 	err = ioctl(fd, SIOCSIFNAME, &ifr);
563 	if (err) {
564 		perror("SIOCSIFNAME");
565 		close(fd);
566 		return -1;
567 	}
568 	close(fd);
569 	return err;
570 }
571 
set_qlen(const char * dev,int qlen)572 static int set_qlen(const char *dev, int qlen)
573 {
574 	struct ifreq ifr;
575 	int s;
576 
577 	s = get_ctl_fd();
578 	if (s < 0)
579 		return -1;
580 
581 	memset(&ifr, 0, sizeof(ifr));
582 	strncpy(ifr.ifr_name, dev, IFNAMSIZ);
583 	ifr.ifr_qlen = qlen;
584 	if (ioctl(s, SIOCSIFTXQLEN, &ifr) < 0) {
585 		perror("SIOCSIFXQLEN");
586 		close(s);
587 		return -1;
588 	}
589 	close(s);
590 
591 	return 0;
592 }
593 
set_mtu(const char * dev,int mtu)594 static int set_mtu(const char *dev, int mtu)
595 {
596 	struct ifreq ifr;
597 	int s;
598 
599 	s = get_ctl_fd();
600 	if (s < 0)
601 		return -1;
602 
603 	memset(&ifr, 0, sizeof(ifr));
604 	strncpy(ifr.ifr_name, dev, IFNAMSIZ);
605 	ifr.ifr_mtu = mtu;
606 	if (ioctl(s, SIOCSIFMTU, &ifr) < 0) {
607 		perror("SIOCSIFMTU");
608 		close(s);
609 		return -1;
610 	}
611 	close(s);
612 
613 	return 0;
614 }
615 
get_address(const char * dev,int * htype)616 static int get_address(const char *dev, int *htype)
617 {
618 	struct ifreq ifr;
619 	struct sockaddr_ll me;
620 	socklen_t alen;
621 	int s;
622 
623 	s = socket(PF_PACKET, SOCK_DGRAM, 0);
624 	if (s < 0) {
625 		perror("socket(PF_PACKET)");
626 		return -1;
627 	}
628 
629 	memset(&ifr, 0, sizeof(ifr));
630 	strncpy(ifr.ifr_name, dev, IFNAMSIZ);
631 	if (ioctl(s, SIOCGIFINDEX, &ifr) < 0) {
632 		perror("SIOCGIFINDEX");
633 		close(s);
634 		return -1;
635 	}
636 
637 	memset(&me, 0, sizeof(me));
638 	me.sll_family = AF_PACKET;
639 	me.sll_ifindex = ifr.ifr_ifindex;
640 	me.sll_protocol = htons(ETH_P_LOOP);
641 	if (bind(s, (struct sockaddr*)&me, sizeof(me)) == -1) {
642 		perror("bind");
643 		close(s);
644 		return -1;
645 	}
646 
647 	alen = sizeof(me);
648 	if (getsockname(s, (struct sockaddr*)&me, &alen) == -1) {
649 		perror("getsockname");
650 		close(s);
651 		return -1;
652 	}
653 	close(s);
654 	*htype = me.sll_hatype;
655 	return me.sll_halen;
656 }
657 
parse_address(const char * dev,int hatype,int halen,char * lla,struct ifreq * ifr)658 static int parse_address(const char *dev, int hatype, int halen,
659 		char *lla, struct ifreq *ifr)
660 {
661 	int alen;
662 
663 	memset(ifr, 0, sizeof(*ifr));
664 	strncpy(ifr->ifr_name, dev, IFNAMSIZ);
665 	ifr->ifr_hwaddr.sa_family = hatype;
666 	alen = ll_addr_a2n(ifr->ifr_hwaddr.sa_data, 14, lla);
667 	if (alen < 0)
668 		return -1;
669 	if (alen != halen) {
670 		fprintf(stderr, "Wrong address (%s) length: expected %d bytes\n", lla, halen);
671 		return -1;
672 	}
673 	return 0;
674 }
675 
set_address(struct ifreq * ifr,int brd)676 static int set_address(struct ifreq *ifr, int brd)
677 {
678 	int s;
679 
680 	s = get_ctl_fd();
681 	if (s < 0)
682 		return -1;
683 	if (ioctl(s, brd?SIOCSIFHWBROADCAST:SIOCSIFHWADDR, ifr) < 0) {
684 		perror(brd?"SIOCSIFHWBROADCAST":"SIOCSIFHWADDR");
685 		close(s);
686 		return -1;
687 	}
688 	close(s);
689 	return 0;
690 }
691 
692 
do_set(int argc,char ** argv)693 static int do_set(int argc, char **argv)
694 {
695 	char *dev = NULL;
696 	__u32 mask = 0;
697 	__u32 flags = 0;
698 	int qlen = -1;
699 	int mtu = -1;
700 	char *newaddr = NULL;
701 	char *newbrd = NULL;
702 	struct ifreq ifr0, ifr1;
703 	char *newname = NULL;
704 	int htype, halen;
705 
706 	while (argc > 0) {
707 		if (strcmp(*argv, "up") == 0) {
708 			mask |= IFF_UP;
709 			flags |= IFF_UP;
710 		} else if (strcmp(*argv, "down") == 0) {
711 			mask |= IFF_UP;
712 			flags &= ~IFF_UP;
713 		} else if (strcmp(*argv, "name") == 0) {
714 			NEXT_ARG();
715 			newname = *argv;
716 		} else if (matches(*argv, "address") == 0) {
717 			NEXT_ARG();
718 			newaddr = *argv;
719 		} else if (matches(*argv, "broadcast") == 0 ||
720 			   strcmp(*argv, "brd") == 0) {
721 			NEXT_ARG();
722 			newbrd = *argv;
723 		} else if (matches(*argv, "txqueuelen") == 0 ||
724 			   strcmp(*argv, "qlen") == 0 ||
725 			   matches(*argv, "txqlen") == 0) {
726 			NEXT_ARG();
727 			if (qlen != -1)
728 				duparg("txqueuelen", *argv);
729 			if (get_integer(&qlen,  *argv, 0))
730 				invarg("Invalid \"txqueuelen\" value\n", *argv);
731 		} else if (strcmp(*argv, "mtu") == 0) {
732 			NEXT_ARG();
733 			if (mtu != -1)
734 				duparg("mtu", *argv);
735 			if (get_integer(&mtu, *argv, 0))
736 				invarg("Invalid \"mtu\" value\n", *argv);
737 		} else if (strcmp(*argv, "multicast") == 0) {
738 			NEXT_ARG();
739 			mask |= IFF_MULTICAST;
740 			if (strcmp(*argv, "on") == 0) {
741 				flags |= IFF_MULTICAST;
742 			} else if (strcmp(*argv, "off") == 0) {
743 				flags &= ~IFF_MULTICAST;
744 			} else
745 				return on_off("multicast");
746 		} else if (strcmp(*argv, "allmulticast") == 0) {
747 			NEXT_ARG();
748 			mask |= IFF_ALLMULTI;
749 			if (strcmp(*argv, "on") == 0) {
750 				flags |= IFF_ALLMULTI;
751 			} else if (strcmp(*argv, "off") == 0) {
752 				flags &= ~IFF_ALLMULTI;
753 			} else
754 				return on_off("allmulticast");
755 		} else if (strcmp(*argv, "promisc") == 0) {
756 			NEXT_ARG();
757 			mask |= IFF_PROMISC;
758 			if (strcmp(*argv, "on") == 0) {
759 				flags |= IFF_PROMISC;
760 			} else if (strcmp(*argv, "off") == 0) {
761 				flags &= ~IFF_PROMISC;
762 			} else
763 				return on_off("promisc");
764 		} else if (strcmp(*argv, "trailers") == 0) {
765 			NEXT_ARG();
766 			mask |= IFF_NOTRAILERS;
767 			if (strcmp(*argv, "off") == 0) {
768 				flags |= IFF_NOTRAILERS;
769 			} else if (strcmp(*argv, "on") == 0) {
770 				flags &= ~IFF_NOTRAILERS;
771 			} else
772 				return on_off("trailers");
773 		} else if (strcmp(*argv, "arp") == 0) {
774 			NEXT_ARG();
775 			mask |= IFF_NOARP;
776 			if (strcmp(*argv, "on") == 0) {
777 				flags &= ~IFF_NOARP;
778 			} else if (strcmp(*argv, "off") == 0) {
779 				flags |= IFF_NOARP;
780 			} else
781 				return on_off("noarp");
782 #ifdef IFF_DYNAMIC
783 		} else if (matches(*argv, "dynamic") == 0) {
784 			NEXT_ARG();
785 			mask |= IFF_DYNAMIC;
786 			if (strcmp(*argv, "on") == 0) {
787 				flags |= IFF_DYNAMIC;
788 			} else if (strcmp(*argv, "off") == 0) {
789 				flags &= ~IFF_DYNAMIC;
790 			} else
791 				return on_off("dynamic");
792 #endif
793 		} else {
794                         if (strcmp(*argv, "dev") == 0) {
795 				NEXT_ARG();
796 			}
797 			if (matches(*argv, "help") == 0)
798 				usage();
799 			if (dev)
800 				duparg2("dev", *argv);
801 			dev = *argv;
802 		}
803 		argc--; argv++;
804 	}
805 
806 	if (!dev) {
807 		fprintf(stderr, "Not enough of information: \"dev\" argument is required.\n");
808 		exit(-1);
809 	}
810 
811 	if (newaddr || newbrd) {
812 		halen = get_address(dev, &htype);
813 		if (halen < 0)
814 			return -1;
815 		if (newaddr) {
816 			if (parse_address(dev, htype, halen, newaddr, &ifr0) < 0)
817 				return -1;
818 		}
819 		if (newbrd) {
820 			if (parse_address(dev, htype, halen, newbrd, &ifr1) < 0)
821 				return -1;
822 		}
823 	}
824 
825 	if (newname && strcmp(dev, newname)) {
826 		if (strlen(newname) == 0)
827 			invarg("\"\" is not a valid device identifier\n", "name");
828 		if (do_changename(dev, newname) < 0)
829 			return -1;
830 		dev = newname;
831 	}
832 	if (qlen != -1) {
833 		if (set_qlen(dev, qlen) < 0)
834 			return -1;
835 	}
836 	if (mtu != -1) {
837 		if (set_mtu(dev, mtu) < 0)
838 			return -1;
839 	}
840 	if (newaddr || newbrd) {
841 		if (newbrd) {
842 			if (set_address(&ifr1, 1) < 0)
843 				return -1;
844 		}
845 		if (newaddr) {
846 			if (set_address(&ifr0, 0) < 0)
847 				return -1;
848 		}
849 	}
850 	if (mask)
851 		return do_chflags(dev, flags, mask);
852 	return 0;
853 }
854 #endif /* IPLINK_IOCTL_COMPAT */
855 
do_iplink(int argc,char ** argv)856 int do_iplink(int argc, char **argv)
857 {
858 	if (argc > 0) {
859 		if (iplink_have_newlink()) {
860 			if (matches(*argv, "add") == 0)
861 				return iplink_modify(RTM_NEWLINK,
862 						     NLM_F_CREATE|NLM_F_EXCL,
863 						     argc-1, argv+1);
864 			if (matches(*argv, "set") == 0 ||
865 			    matches(*argv, "change") == 0)
866 				return iplink_modify(RTM_NEWLINK, 0,
867 						     argc-1, argv+1);
868 			if (matches(*argv, "replace") == 0)
869 				return iplink_modify(RTM_NEWLINK,
870 						     NLM_F_CREATE|NLM_F_REPLACE,
871 						     argc-1, argv+1);
872 			if (matches(*argv, "delete") == 0)
873 				return iplink_modify(RTM_DELLINK, 0,
874 						     argc-1, argv+1);
875 		} else {
876 #if IPLINK_IOCTL_COMPAT
877 			if (matches(*argv, "set") == 0)
878 				return do_set(argc-1, argv+1);
879 #endif
880 		}
881 		if (matches(*argv, "show") == 0 ||
882 		    matches(*argv, "lst") == 0 ||
883 		    matches(*argv, "list") == 0)
884 			return ipaddr_list_link(argc-1, argv+1);
885 		if (matches(*argv, "help") == 0)
886 			usage();
887 	} else
888 		return ipaddr_list_link(0, NULL);
889 
890 	fprintf(stderr, "Command \"%s\" is unknown, try \"ip link help\".\n", *argv);
891 	exit(-1);
892 }
893