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 { dev DEVICE | group DEVGROUP } [ { 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, "	                  [ netns NAME ]\n");
71 	fprintf(stderr, "			  [ alias NAME ]\n");
72 	fprintf(stderr, "	                  [ vf NUM [ mac LLADDR ]\n");
73 	fprintf(stderr, "				   [ vlan VLANID [ qos VLAN-QOS ] ]\n");
74 
75 	fprintf(stderr, "				   [ rate TXRATE ] ] \n");
76 
77 	fprintf(stderr, "				   [ spoofchk { on | off} ] ] \n");
78 	fprintf(stderr, "			  [ master DEVICE ]\n");
79 	fprintf(stderr, "			  [ nomaster ]\n");
80 	fprintf(stderr, "       ip link show [ DEVICE | group GROUP ]\n");
81 
82 	if (iplink_have_newlink()) {
83 		fprintf(stderr, "\n");
84 		fprintf(stderr, "TYPE := { vlan | veth | vcan | dummy | ifb | macvlan | can | bridge }\n");
85 	}
86 	exit(-1);
87 }
88 
usage(void)89 static void usage(void)
90 {
91 	iplink_usage();
92 }
93 
on_off(char * msg)94 static int on_off(char *msg)
95 {
96 	fprintf(stderr, "Error: argument of \"%s\" must be \"on\" or \"off\"\n", msg);
97 	return -1;
98 }
99 
100 static void *BODY;		/* cached dlopen(NULL) handle */
101 static struct link_util *linkutil_list;
102 
get_link_kind(const char * id)103 struct link_util *get_link_kind(const char *id)
104 {
105 	void *dlh;
106 	char buf[256];
107 	struct link_util *l;
108 
109 	for (l = linkutil_list; l; l = l->next)
110 		if (strcmp(l->id, id) == 0)
111 			return l;
112 
113 	snprintf(buf, sizeof(buf), LIBDIR "/ip/link_%s.so", id);
114 	dlh = dlopen(buf, RTLD_LAZY);
115 	if (dlh == NULL) {
116 		/* look in current binary, only open once */
117 		dlh = BODY;
118 		if (dlh == NULL) {
119 			dlh = BODY = dlopen(NULL, RTLD_LAZY);
120 			if (dlh == NULL)
121 				return NULL;
122 		}
123 	}
124 
125 	snprintf(buf, sizeof(buf), "%s_link_util", id);
126 	l = dlsym(dlh, buf);
127 	if (l == NULL)
128 		return NULL;
129 
130 	l->next = linkutil_list;
131 	linkutil_list = l;
132 	return l;
133 }
134 
get_link_mode(const char * mode)135 int get_link_mode(const char *mode)
136 {
137 	if (strcasecmp(mode, "default") == 0)
138 		return IF_LINK_MODE_DEFAULT;
139 	if (strcasecmp(mode, "dormant") == 0)
140 		return IF_LINK_MODE_DORMANT;
141 	return -1;
142 }
143 
144 #if IPLINK_IOCTL_COMPAT
145 static int have_rtnl_newlink = -1;
146 
accept_msg(const struct sockaddr_nl * who,struct nlmsghdr * n,void * arg)147 static int accept_msg(const struct sockaddr_nl *who,
148 		      struct nlmsghdr *n, void *arg)
149 {
150 	struct nlmsgerr *err = (struct nlmsgerr *)NLMSG_DATA(n);
151 
152 	if (n->nlmsg_type == NLMSG_ERROR &&
153 	    (err->error == -EOPNOTSUPP || err->error == -EINVAL))
154 		have_rtnl_newlink = 0;
155 	else
156 		have_rtnl_newlink = 1;
157 	return -1;
158 }
159 
iplink_have_newlink(void)160 static int iplink_have_newlink(void)
161 {
162 	struct {
163 		struct nlmsghdr		n;
164 		struct ifinfomsg	i;
165 		char			buf[1024];
166 	} req;
167 
168 	if (have_rtnl_newlink < 0) {
169 		memset(&req, 0, sizeof(req));
170 
171 		req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
172 		req.n.nlmsg_flags = NLM_F_REQUEST|NLM_F_ACK;
173 		req.n.nlmsg_type = RTM_NEWLINK;
174 		req.i.ifi_family = AF_UNSPEC;
175 
176 		rtnl_send(&rth, &req.n, req.n.nlmsg_len);
177 		rtnl_listen(&rth, accept_msg, NULL);
178 	}
179 	return have_rtnl_newlink;
180 }
181 #else /* IPLINK_IOCTL_COMPAT */
iplink_have_newlink(void)182 static int iplink_have_newlink(void)
183 {
184 	return 1;
185 }
186 #endif /* ! IPLINK_IOCTL_COMPAT */
187 
188 struct iplink_req {
189 	struct nlmsghdr		n;
190 	struct ifinfomsg	i;
191 	char			buf[1024];
192 };
193 
iplink_parse_vf(int vf,int * argcp,char *** argvp,struct iplink_req * req)194 int iplink_parse_vf(int vf, int *argcp, char ***argvp,
195 			   struct iplink_req *req)
196 {
197 	int len, argc = *argcp;
198 	char **argv = *argvp;
199 	struct rtattr *vfinfo;
200 
201 	vfinfo = addattr_nest(&req->n, sizeof(*req), IFLA_VF_INFO);
202 
203 	while (NEXT_ARG_OK()) {
204 		NEXT_ARG();
205 		if (matches(*argv, "mac") == 0) {
206 			struct ifla_vf_mac ivm;
207 			NEXT_ARG();
208 			ivm.vf = vf;
209 			len = ll_addr_a2n((char *)ivm.mac, 32, *argv);
210 			if (len < 0)
211 				return -1;
212 			addattr_l(&req->n, sizeof(*req), IFLA_VF_MAC, &ivm, sizeof(ivm));
213 		} else if (matches(*argv, "vlan") == 0) {
214 			struct ifla_vf_vlan ivv;
215 			NEXT_ARG();
216 			if (get_unsigned(&ivv.vlan, *argv, 0)) {
217 				invarg("Invalid \"vlan\" value\n", *argv);
218 			}
219 			ivv.vf = vf;
220 			ivv.qos = 0;
221 			if (NEXT_ARG_OK()) {
222 				NEXT_ARG();
223 				if (matches(*argv, "qos") == 0) {
224 					NEXT_ARG();
225 					if (get_unsigned(&ivv.qos, *argv, 0)) {
226 						invarg("Invalid \"qos\" value\n", *argv);
227 					}
228 				} else {
229 					/* rewind arg */
230 					PREV_ARG();
231 				}
232 			}
233 			addattr_l(&req->n, sizeof(*req), IFLA_VF_VLAN, &ivv, sizeof(ivv));
234 		} else if (matches(*argv, "rate") == 0) {
235 			struct ifla_vf_tx_rate ivt;
236 			NEXT_ARG();
237 			if (get_unsigned(&ivt.rate, *argv, 0)) {
238 				invarg("Invalid \"rate\" value\n", *argv);
239 			}
240 			ivt.vf = vf;
241 			addattr_l(&req->n, sizeof(*req), IFLA_VF_TX_RATE, &ivt, sizeof(ivt));
242 
243 		} else if (matches(*argv, "spoofchk") == 0) {
244 			struct ifla_vf_spoofchk ivs;
245 			NEXT_ARG();
246 			if (matches(*argv, "on") == 0)
247 				ivs.setting = 1;
248 			else if (matches(*argv, "off") == 0)
249 				ivs.setting = 0;
250 			else
251 				invarg("Invalid \"spoofchk\" value\n", *argv);
252 			ivs.vf = vf;
253 			addattr_l(&req->n, sizeof(*req), IFLA_VF_SPOOFCHK, &ivs, sizeof(ivs));
254 
255 		} else {
256 			/* rewind arg */
257 			PREV_ARG();
258 			break;
259 		}
260 	}
261 
262 	if (argc == *argcp)
263 		incomplete_command();
264 
265 	addattr_nest_end(&req->n, vfinfo);
266 
267 	*argcp = argc;
268 	*argvp = argv;
269 	return 0;
270 }
271 
272 
iplink_parse(int argc,char ** argv,struct iplink_req * req,char ** name,char ** type,char ** link,char ** dev,int * group)273 int iplink_parse(int argc, char **argv, struct iplink_req *req,
274 		char **name, char **type, char **link, char **dev, int *group)
275 {
276 	int ret, len;
277 	char abuf[32];
278 	int qlen = -1;
279 	int mtu = -1;
280 	int netns = -1;
281 	int vf = -1;
282 
283 	*group = -1;
284 	ret = argc;
285 
286 	while (argc > 0) {
287 		if (strcmp(*argv, "up") == 0) {
288 			req->i.ifi_change |= IFF_UP;
289 			req->i.ifi_flags |= IFF_UP;
290 		} else if (strcmp(*argv, "down") == 0) {
291 			req->i.ifi_change |= IFF_UP;
292 			req->i.ifi_flags &= ~IFF_UP;
293 		} else if (strcmp(*argv, "name") == 0) {
294 			NEXT_ARG();
295 			*name = *argv;
296 		} else if (matches(*argv, "link") == 0) {
297 			NEXT_ARG();
298 			*link = *argv;
299 		} else if (matches(*argv, "address") == 0) {
300 			NEXT_ARG();
301 			len = ll_addr_a2n(abuf, sizeof(abuf), *argv);
302 			if (len < 0)
303 				return -1;
304 			addattr_l(&req->n, sizeof(*req), IFLA_ADDRESS, abuf, len);
305 		} else if (matches(*argv, "broadcast") == 0 ||
306 				strcmp(*argv, "brd") == 0) {
307 			NEXT_ARG();
308 			len = ll_addr_a2n(abuf, sizeof(abuf), *argv);
309 			if (len < 0)
310 				return -1;
311 			addattr_l(&req->n, sizeof(*req), IFLA_BROADCAST, abuf, len);
312 		} else if (matches(*argv, "txqueuelen") == 0 ||
313 				strcmp(*argv, "qlen") == 0 ||
314 				matches(*argv, "txqlen") == 0) {
315 			NEXT_ARG();
316 			if (qlen != -1)
317 				duparg("txqueuelen", *argv);
318 			if (get_integer(&qlen,  *argv, 0))
319 				invarg("Invalid \"txqueuelen\" value\n", *argv);
320 			addattr_l(&req->n, sizeof(*req), IFLA_TXQLEN, &qlen, 4);
321 		} else if (strcmp(*argv, "mtu") == 0) {
322 			NEXT_ARG();
323 			if (mtu != -1)
324 				duparg("mtu", *argv);
325 			if (get_integer(&mtu, *argv, 0))
326 				invarg("Invalid \"mtu\" value\n", *argv);
327 			addattr_l(&req->n, sizeof(*req), IFLA_MTU, &mtu, 4);
328                 } else if (strcmp(*argv, "netns") == 0) {
329                         NEXT_ARG();
330                         if (netns != -1)
331                                 duparg("netns", *argv);
332 			if ((netns = get_netns_fd(*argv)) >= 0)
333 				addattr_l(&req->n, sizeof(*req), IFLA_NET_NS_FD, &netns, 4);
334 			else if (get_integer(&netns, *argv, 0) == 0)
335 				addattr_l(&req->n, sizeof(*req), IFLA_NET_NS_PID, &netns, 4);
336 			else
337                                 invarg("Invalid \"netns\" value\n", *argv);
338 		} else if (strcmp(*argv, "multicast") == 0) {
339 			NEXT_ARG();
340 			req->i.ifi_change |= IFF_MULTICAST;
341 			if (strcmp(*argv, "on") == 0) {
342 				req->i.ifi_flags |= IFF_MULTICAST;
343 			} else if (strcmp(*argv, "off") == 0) {
344 				req->i.ifi_flags &= ~IFF_MULTICAST;
345 			} else
346 				return on_off("multicast");
347 		} else if (strcmp(*argv, "allmulticast") == 0) {
348 			NEXT_ARG();
349 			req->i.ifi_change |= IFF_ALLMULTI;
350 			if (strcmp(*argv, "on") == 0) {
351 				req->i.ifi_flags |= IFF_ALLMULTI;
352 			} else if (strcmp(*argv, "off") == 0) {
353 				req->i.ifi_flags &= ~IFF_ALLMULTI;
354 			} else
355 				return on_off("allmulticast");
356 		} else if (strcmp(*argv, "promisc") == 0) {
357 			NEXT_ARG();
358 			req->i.ifi_change |= IFF_PROMISC;
359 			if (strcmp(*argv, "on") == 0) {
360 				req->i.ifi_flags |= IFF_PROMISC;
361 			} else if (strcmp(*argv, "off") == 0) {
362 				req->i.ifi_flags &= ~IFF_PROMISC;
363 			} else
364 				return on_off("promisc");
365 		} else if (strcmp(*argv, "trailers") == 0) {
366 			NEXT_ARG();
367 			req->i.ifi_change |= IFF_NOTRAILERS;
368 			if (strcmp(*argv, "off") == 0) {
369 				req->i.ifi_flags |= IFF_NOTRAILERS;
370 			} else if (strcmp(*argv, "on") == 0) {
371 				req->i.ifi_flags &= ~IFF_NOTRAILERS;
372 			} else
373 				return on_off("trailers");
374 		} else if (strcmp(*argv, "arp") == 0) {
375 			NEXT_ARG();
376 			req->i.ifi_change |= IFF_NOARP;
377 			if (strcmp(*argv, "on") == 0) {
378 				req->i.ifi_flags &= ~IFF_NOARP;
379 			} else if (strcmp(*argv, "off") == 0) {
380 				req->i.ifi_flags |= IFF_NOARP;
381 			} else
382 				return on_off("noarp");
383 		} else if (strcmp(*argv, "vf") == 0) {
384 			struct rtattr *vflist;
385 			NEXT_ARG();
386 			if (get_integer(&vf,  *argv, 0)) {
387 				invarg("Invalid \"vf\" value\n", *argv);
388 			}
389 			vflist = addattr_nest(&req->n, sizeof(*req),
390 					      IFLA_VFINFO_LIST);
391 			len = iplink_parse_vf(vf, &argc, &argv, req);
392 			if (len < 0)
393 				return -1;
394 			addattr_nest_end(&req->n, vflist);
395 		} else if (matches(*argv, "master") == 0) {
396 			int ifindex;
397 			NEXT_ARG();
398 			ifindex = ll_name_to_index(*argv);
399 			if (!ifindex)
400 				invarg("Device does not exist\n", *argv);
401 			addattr_l(&req->n, sizeof(*req), IFLA_MASTER,
402 				  &ifindex, 4);
403 		} else if (matches(*argv, "nomaster") == 0) {
404 			int ifindex = 0;
405 			addattr_l(&req->n, sizeof(*req), IFLA_MASTER,
406 				  &ifindex, 4);
407 		} else if (matches(*argv, "dynamic") == 0) {
408 			NEXT_ARG();
409 			req->i.ifi_change |= IFF_DYNAMIC;
410 			if (strcmp(*argv, "on") == 0) {
411 				req->i.ifi_flags |= IFF_DYNAMIC;
412 			} else if (strcmp(*argv, "off") == 0) {
413 				req->i.ifi_flags &= ~IFF_DYNAMIC;
414 			} else
415 				return on_off("dynamic");
416 		} else if (matches(*argv, "type") == 0) {
417 			NEXT_ARG();
418 			*type = *argv;
419 			argc--; argv++;
420 			break;
421 		} else if (matches(*argv, "alias") == 0) {
422 			NEXT_ARG();
423 			addattr_l(&req->n, sizeof(*req), IFLA_IFALIAS,
424 				  *argv, strlen(*argv));
425 			argc--; argv++;
426 			break;
427 		} else if (strcmp(*argv, "group") == 0) {
428 			NEXT_ARG();
429 			if (*group != -1)
430 				duparg("group", *argv);
431 			if (rtnl_group_a2n(group, *argv))
432 				invarg("Invalid \"group\" value\n", *argv);
433 		} else if (strcmp(*argv, "mode") == 0) {
434 			int mode;
435 			NEXT_ARG();
436 			mode = get_link_mode(*argv);
437 			if (mode < 0)
438 				invarg("Invalid link mode\n", *argv);
439 			addattr8(&req->n, sizeof(*req), IFLA_LINKMODE, mode);
440 		} else if (strcmp(*argv, "state") == 0) {
441 			int state;
442 			NEXT_ARG();
443 			state = get_operstate(*argv);
444 			if (state < 0)
445 				invarg("Invalid operstate\n", *argv);
446 
447 			addattr8(&req->n, sizeof(*req), IFLA_OPERSTATE, state);
448 		} else {
449 			if (strcmp(*argv, "dev") == 0) {
450 				NEXT_ARG();
451 			}
452 			if (matches(*argv, "help") == 0)
453 				usage();
454 			if (*dev)
455 				duparg2("dev", *argv);
456 			*dev = *argv;
457 		}
458 		argc--; argv++;
459 	}
460 
461 	return ret - argc;
462 }
463 
iplink_modify(int cmd,unsigned int flags,int argc,char ** argv)464 static int iplink_modify(int cmd, unsigned int flags, int argc, char **argv)
465 {
466 	int len;
467 	char *dev = NULL;
468 	char *name = NULL;
469 	char *link = NULL;
470 	char *type = NULL;
471 	int group;
472 	struct link_util *lu = NULL;
473 	struct iplink_req req;
474 	int ret;
475 
476 	memset(&req, 0, sizeof(req));
477 
478 	req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
479 	req.n.nlmsg_flags = NLM_F_REQUEST|flags;
480 	req.n.nlmsg_type = cmd;
481 	req.i.ifi_family = preferred_family;
482 
483 	ret = iplink_parse(argc, argv, &req, &name, &type, &link, &dev, &group);
484 	if (ret < 0)
485 		return ret;
486 
487 	argc -= ret;
488 	argv += ret;
489 
490 	if (group != -1) {
491 		if (dev)
492 			addattr_l(&req.n, sizeof(req), IFLA_GROUP,
493 					&group, sizeof(group));
494 		else {
495 			if (argc) {
496 				fprintf(stderr, "Garbage instead of arguments "
497 						"\"%s ...\". Try \"ip link "
498 						"help\".\n", *argv);
499 				return -1;
500 			}
501 			if (flags & NLM_F_CREATE) {
502 				fprintf(stderr, "group cannot be used when "
503 						"creating devices.\n");
504 				return -1;
505 			}
506 
507 			req.i.ifi_index = 0;
508 			addattr32(&req.n, sizeof(req), IFLA_GROUP, group);
509 			if (rtnl_talk(&rth, &req.n, 0, 0, NULL) < 0)
510 				exit(2);
511 			return 0;
512 		}
513 	}
514 
515 	ll_init_map(&rth);
516 
517 	if (!(flags & NLM_F_CREATE)) {
518 		if (!dev) {
519 			fprintf(stderr, "Not enough information: \"dev\" "
520 					"argument is required.\n");
521 			exit(-1);
522 		}
523 
524 		req.i.ifi_index = ll_name_to_index(dev);
525 		if (req.i.ifi_index == 0) {
526 			fprintf(stderr, "Cannot find device \"%s\"\n", dev);
527 			return -1;
528 		}
529 	} else {
530 		/* Allow "ip link add dev" and "ip link add name" */
531 		if (!name)
532 			name = dev;
533 
534 		if (link) {
535 			int ifindex;
536 
537 			ifindex = ll_name_to_index(link);
538 			if (ifindex == 0) {
539 				fprintf(stderr, "Cannot find device \"%s\"\n",
540 					link);
541 				return -1;
542 			}
543 			addattr_l(&req.n, sizeof(req), IFLA_LINK, &ifindex, 4);
544 		}
545 	}
546 
547 	if (name) {
548 		len = strlen(name) + 1;
549 		if (len == 1)
550 			invarg("\"\" is not a valid device identifier\n", "name");
551 		if (len > IFNAMSIZ)
552 			invarg("\"name\" too long\n", name);
553 		addattr_l(&req.n, sizeof(req), IFLA_IFNAME, name, len);
554 	}
555 
556 	if (type) {
557 		struct rtattr *linkinfo = NLMSG_TAIL(&req.n);
558 		addattr_l(&req.n, sizeof(req), IFLA_LINKINFO, NULL, 0);
559 		addattr_l(&req.n, sizeof(req), IFLA_INFO_KIND, type,
560 			 strlen(type));
561 
562 		lu = get_link_kind(type);
563 		if (lu && argc) {
564 			struct rtattr * data = NLMSG_TAIL(&req.n);
565 			addattr_l(&req.n, sizeof(req), IFLA_INFO_DATA, NULL, 0);
566 
567 			if (lu->parse_opt &&
568 			    lu->parse_opt(lu, argc, argv, &req.n))
569 				return -1;
570 
571 			data->rta_len = (void *)NLMSG_TAIL(&req.n) - (void *)data;
572 		} else if (argc) {
573 			if (matches(*argv, "help") == 0)
574 				usage();
575 			fprintf(stderr, "Garbage instead of arguments \"%s ...\". "
576 					"Try \"ip link help\".\n", *argv);
577 			return -1;
578 		}
579 		linkinfo->rta_len = (void *)NLMSG_TAIL(&req.n) - (void *)linkinfo;
580 	} else if (flags & NLM_F_CREATE) {
581 		fprintf(stderr, "Not enough information: \"type\" argument "
582 				"is required\n");
583 		return -1;
584 	}
585 
586 	if (rtnl_talk(&rth, &req.n, 0, 0, NULL) < 0)
587 		exit(2);
588 
589 	return 0;
590 }
591 
592 #if IPLINK_IOCTL_COMPAT
get_ctl_fd(void)593 static int get_ctl_fd(void)
594 {
595 	int s_errno;
596 	int fd;
597 
598 	fd = socket(PF_INET, SOCK_DGRAM, 0);
599 	if (fd >= 0)
600 		return fd;
601 	s_errno = errno;
602 	fd = socket(PF_PACKET, SOCK_DGRAM, 0);
603 	if (fd >= 0)
604 		return fd;
605 	fd = socket(PF_INET6, SOCK_DGRAM, 0);
606 	if (fd >= 0)
607 		return fd;
608 	errno = s_errno;
609 	perror("Cannot create control socket");
610 	return -1;
611 }
612 
do_chflags(const char * dev,__u32 flags,__u32 mask)613 static int do_chflags(const char *dev, __u32 flags, __u32 mask)
614 {
615 	struct ifreq ifr;
616 	int fd;
617 	int err;
618 
619 	strncpy(ifr.ifr_name, dev, IFNAMSIZ);
620 	fd = get_ctl_fd();
621 	if (fd < 0)
622 		return -1;
623 	err = ioctl(fd, SIOCGIFFLAGS, &ifr);
624 	if (err) {
625 		perror("SIOCGIFFLAGS");
626 		close(fd);
627 		return -1;
628 	}
629 	if ((ifr.ifr_flags^flags)&mask) {
630 		ifr.ifr_flags &= ~mask;
631 		ifr.ifr_flags |= mask&flags;
632 		err = ioctl(fd, SIOCSIFFLAGS, &ifr);
633 		if (err)
634 			perror("SIOCSIFFLAGS");
635 	}
636 	close(fd);
637 	return err;
638 }
639 
do_changename(const char * dev,const char * newdev)640 static int do_changename(const char *dev, const char *newdev)
641 {
642 	struct ifreq ifr;
643 	int fd;
644 	int err;
645 
646 	strncpy(ifr.ifr_name, dev, IFNAMSIZ);
647 	strncpy(ifr.ifr_newname, newdev, IFNAMSIZ);
648 	fd = get_ctl_fd();
649 	if (fd < 0)
650 		return -1;
651 	err = ioctl(fd, SIOCSIFNAME, &ifr);
652 	if (err) {
653 		perror("SIOCSIFNAME");
654 		close(fd);
655 		return -1;
656 	}
657 	close(fd);
658 	return err;
659 }
660 
set_qlen(const char * dev,int qlen)661 static int set_qlen(const char *dev, int qlen)
662 {
663 	struct ifreq ifr;
664 	int s;
665 
666 	s = get_ctl_fd();
667 	if (s < 0)
668 		return -1;
669 
670 	memset(&ifr, 0, sizeof(ifr));
671 	strncpy(ifr.ifr_name, dev, IFNAMSIZ);
672 	ifr.ifr_qlen = qlen;
673 	if (ioctl(s, SIOCSIFTXQLEN, &ifr) < 0) {
674 		perror("SIOCSIFXQLEN");
675 		close(s);
676 		return -1;
677 	}
678 	close(s);
679 
680 	return 0;
681 }
682 
set_mtu(const char * dev,int mtu)683 static int set_mtu(const char *dev, int mtu)
684 {
685 	struct ifreq ifr;
686 	int s;
687 
688 	s = get_ctl_fd();
689 	if (s < 0)
690 		return -1;
691 
692 	memset(&ifr, 0, sizeof(ifr));
693 	strncpy(ifr.ifr_name, dev, IFNAMSIZ);
694 	ifr.ifr_mtu = mtu;
695 	if (ioctl(s, SIOCSIFMTU, &ifr) < 0) {
696 		perror("SIOCSIFMTU");
697 		close(s);
698 		return -1;
699 	}
700 	close(s);
701 
702 	return 0;
703 }
704 
get_address(const char * dev,int * htype)705 static int get_address(const char *dev, int *htype)
706 {
707 	struct ifreq ifr;
708 	struct sockaddr_ll me;
709 	socklen_t alen;
710 	int s;
711 
712 	s = socket(PF_PACKET, SOCK_DGRAM, 0);
713 	if (s < 0) {
714 		perror("socket(PF_PACKET)");
715 		return -1;
716 	}
717 
718 	memset(&ifr, 0, sizeof(ifr));
719 	strncpy(ifr.ifr_name, dev, IFNAMSIZ);
720 	if (ioctl(s, SIOCGIFINDEX, &ifr) < 0) {
721 		perror("SIOCGIFINDEX");
722 		close(s);
723 		return -1;
724 	}
725 
726 	memset(&me, 0, sizeof(me));
727 	me.sll_family = AF_PACKET;
728 	me.sll_ifindex = ifr.ifr_ifindex;
729 	me.sll_protocol = htons(ETH_P_LOOP);
730 	if (bind(s, (struct sockaddr*)&me, sizeof(me)) == -1) {
731 		perror("bind");
732 		close(s);
733 		return -1;
734 	}
735 
736 	alen = sizeof(me);
737 	if (getsockname(s, (struct sockaddr*)&me, &alen) == -1) {
738 		perror("getsockname");
739 		close(s);
740 		return -1;
741 	}
742 	close(s);
743 	*htype = me.sll_hatype;
744 	return me.sll_halen;
745 }
746 
parse_address(const char * dev,int hatype,int halen,char * lla,struct ifreq * ifr)747 static int parse_address(const char *dev, int hatype, int halen,
748 		char *lla, struct ifreq *ifr)
749 {
750 	int alen;
751 
752 	memset(ifr, 0, sizeof(*ifr));
753 	strncpy(ifr->ifr_name, dev, IFNAMSIZ);
754 	ifr->ifr_hwaddr.sa_family = hatype;
755 	alen = ll_addr_a2n(ifr->ifr_hwaddr.sa_data, 14, lla);
756 	if (alen < 0)
757 		return -1;
758 	if (alen != halen) {
759 		fprintf(stderr, "Wrong address (%s) length: expected %d bytes\n", lla, halen);
760 		return -1;
761 	}
762 	return 0;
763 }
764 
set_address(struct ifreq * ifr,int brd)765 static int set_address(struct ifreq *ifr, int brd)
766 {
767 	int s;
768 
769 	s = get_ctl_fd();
770 	if (s < 0)
771 		return -1;
772 	if (ioctl(s, brd?SIOCSIFHWBROADCAST:SIOCSIFHWADDR, ifr) < 0) {
773 		perror(brd?"SIOCSIFHWBROADCAST":"SIOCSIFHWADDR");
774 		close(s);
775 		return -1;
776 	}
777 	close(s);
778 	return 0;
779 }
780 
781 
do_set(int argc,char ** argv)782 static int do_set(int argc, char **argv)
783 {
784 	char *dev = NULL;
785 	__u32 mask = 0;
786 	__u32 flags = 0;
787 	int qlen = -1;
788 	int mtu = -1;
789 	char *newaddr = NULL;
790 	char *newbrd = NULL;
791 	struct ifreq ifr0, ifr1;
792 	char *newname = NULL;
793 	int htype, halen;
794 
795 	while (argc > 0) {
796 		if (strcmp(*argv, "up") == 0) {
797 			mask |= IFF_UP;
798 			flags |= IFF_UP;
799 		} else if (strcmp(*argv, "down") == 0) {
800 			mask |= IFF_UP;
801 			flags &= ~IFF_UP;
802 		} else if (strcmp(*argv, "name") == 0) {
803 			NEXT_ARG();
804 			newname = *argv;
805 		} else if (matches(*argv, "address") == 0) {
806 			NEXT_ARG();
807 			newaddr = *argv;
808 		} else if (matches(*argv, "broadcast") == 0 ||
809 			   strcmp(*argv, "brd") == 0) {
810 			NEXT_ARG();
811 			newbrd = *argv;
812 		} else if (matches(*argv, "txqueuelen") == 0 ||
813 			   strcmp(*argv, "qlen") == 0 ||
814 			   matches(*argv, "txqlen") == 0) {
815 			NEXT_ARG();
816 			if (qlen != -1)
817 				duparg("txqueuelen", *argv);
818 			if (get_integer(&qlen,  *argv, 0))
819 				invarg("Invalid \"txqueuelen\" value\n", *argv);
820 		} else if (strcmp(*argv, "mtu") == 0) {
821 			NEXT_ARG();
822 			if (mtu != -1)
823 				duparg("mtu", *argv);
824 			if (get_integer(&mtu, *argv, 0))
825 				invarg("Invalid \"mtu\" value\n", *argv);
826 		} else if (strcmp(*argv, "multicast") == 0) {
827 			NEXT_ARG();
828 			mask |= IFF_MULTICAST;
829 			if (strcmp(*argv, "on") == 0) {
830 				flags |= IFF_MULTICAST;
831 			} else if (strcmp(*argv, "off") == 0) {
832 				flags &= ~IFF_MULTICAST;
833 			} else
834 				return on_off("multicast");
835 		} else if (strcmp(*argv, "allmulticast") == 0) {
836 			NEXT_ARG();
837 			mask |= IFF_ALLMULTI;
838 			if (strcmp(*argv, "on") == 0) {
839 				flags |= IFF_ALLMULTI;
840 			} else if (strcmp(*argv, "off") == 0) {
841 				flags &= ~IFF_ALLMULTI;
842 			} else
843 				return on_off("allmulticast");
844 		} else if (strcmp(*argv, "promisc") == 0) {
845 			NEXT_ARG();
846 			mask |= IFF_PROMISC;
847 			if (strcmp(*argv, "on") == 0) {
848 				flags |= IFF_PROMISC;
849 			} else if (strcmp(*argv, "off") == 0) {
850 				flags &= ~IFF_PROMISC;
851 			} else
852 				return on_off("promisc");
853 		} else if (strcmp(*argv, "trailers") == 0) {
854 			NEXT_ARG();
855 			mask |= IFF_NOTRAILERS;
856 			if (strcmp(*argv, "off") == 0) {
857 				flags |= IFF_NOTRAILERS;
858 			} else if (strcmp(*argv, "on") == 0) {
859 				flags &= ~IFF_NOTRAILERS;
860 			} else
861 				return on_off("trailers");
862 		} else if (strcmp(*argv, "arp") == 0) {
863 			NEXT_ARG();
864 			mask |= IFF_NOARP;
865 			if (strcmp(*argv, "on") == 0) {
866 				flags &= ~IFF_NOARP;
867 			} else if (strcmp(*argv, "off") == 0) {
868 				flags |= IFF_NOARP;
869 			} else
870 				return on_off("noarp");
871 		} else if (matches(*argv, "dynamic") == 0) {
872 			NEXT_ARG();
873 			mask |= IFF_DYNAMIC;
874 			if (strcmp(*argv, "on") == 0) {
875 				flags |= IFF_DYNAMIC;
876 			} else if (strcmp(*argv, "off") == 0) {
877 				flags &= ~IFF_DYNAMIC;
878 			} else
879 				return on_off("dynamic");
880 		} else {
881                         if (strcmp(*argv, "dev") == 0) {
882 				NEXT_ARG();
883 			}
884 			if (matches(*argv, "help") == 0)
885 				usage();
886 			if (dev)
887 				duparg2("dev", *argv);
888 			dev = *argv;
889 		}
890 		argc--; argv++;
891 	}
892 
893 	if (!dev) {
894 		fprintf(stderr, "Not enough of information: \"dev\" argument is required.\n");
895 		exit(-1);
896 	}
897 
898 	if (newaddr || newbrd) {
899 		halen = get_address(dev, &htype);
900 		if (halen < 0)
901 			return -1;
902 		if (newaddr) {
903 			if (parse_address(dev, htype, halen, newaddr, &ifr0) < 0)
904 				return -1;
905 		}
906 		if (newbrd) {
907 			if (parse_address(dev, htype, halen, newbrd, &ifr1) < 0)
908 				return -1;
909 		}
910 	}
911 
912 	if (newname && strcmp(dev, newname)) {
913 		if (strlen(newname) == 0)
914 			invarg("\"\" is not a valid device identifier\n", "name");
915 		if (do_changename(dev, newname) < 0)
916 			return -1;
917 		dev = newname;
918 	}
919 	if (qlen != -1) {
920 		if (set_qlen(dev, qlen) < 0)
921 			return -1;
922 	}
923 	if (mtu != -1) {
924 		if (set_mtu(dev, mtu) < 0)
925 			return -1;
926 	}
927 	if (newaddr || newbrd) {
928 		if (newbrd) {
929 			if (set_address(&ifr1, 1) < 0)
930 				return -1;
931 		}
932 		if (newaddr) {
933 			if (set_address(&ifr0, 0) < 0)
934 				return -1;
935 		}
936 	}
937 	if (mask)
938 		return do_chflags(dev, flags, mask);
939 	return 0;
940 }
941 #endif /* IPLINK_IOCTL_COMPAT */
942 
do_iplink(int argc,char ** argv)943 int do_iplink(int argc, char **argv)
944 {
945 	if (argc > 0) {
946 		if (iplink_have_newlink()) {
947 			if (matches(*argv, "add") == 0)
948 				return iplink_modify(RTM_NEWLINK,
949 						     NLM_F_CREATE|NLM_F_EXCL,
950 						     argc-1, argv+1);
951 			if (matches(*argv, "set") == 0 ||
952 			    matches(*argv, "change") == 0)
953 				return iplink_modify(RTM_NEWLINK, 0,
954 						     argc-1, argv+1);
955 			if (matches(*argv, "replace") == 0)
956 				return iplink_modify(RTM_NEWLINK,
957 						     NLM_F_CREATE|NLM_F_REPLACE,
958 						     argc-1, argv+1);
959 			if (matches(*argv, "delete") == 0)
960 				return iplink_modify(RTM_DELLINK, 0,
961 						     argc-1, argv+1);
962 		} else {
963 #if IPLINK_IOCTL_COMPAT
964 			if (matches(*argv, "set") == 0)
965 				return do_set(argc-1, argv+1);
966 #endif
967 		}
968 		if (matches(*argv, "show") == 0 ||
969 		    matches(*argv, "lst") == 0 ||
970 		    matches(*argv, "list") == 0)
971 			return ipaddr_list_link(argc-1, argv+1);
972 		if (matches(*argv, "help") == 0)
973 			usage();
974 	} else
975 		return ipaddr_list_link(0, NULL);
976 
977 	fprintf(stderr, "Command \"%s\" is unknown, try \"ip link help\".\n", *argv);
978 	exit(-1);
979 }
980