iplink.c revision ae665a522bd46bea44c5ea84c89c8b1731954170 
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 <errno.h>
19#include <sys/socket.h>
20#include <linux/if.h>
21#include <linux/if_packet.h>
22#include <linux/if_ether.h>
23#include <linux/sockios.h>
24#include <netinet/in.h>
25#include <arpa/inet.h>
26#include <string.h>
27#include <sys/ioctl.h>
28#include <linux/sockios.h>
29
30#include "rt_names.h"
31#include "utils.h"
32#include "ip_common.h"
33
34
35static void usage(void) __attribute__((noreturn));
36
37void iplink_usage(void)
38{
39	fprintf(stderr, "Usage: ip link set DEVICE { up | down |\n");
40	fprintf(stderr, "	                     arp { on | off } |\n");
41	fprintf(stderr, "	                     dynamic { on | off } |\n");
42	fprintf(stderr, "	                     multicast { on | off } |\n");
43	fprintf(stderr, "	                     allmulticast { on | off } |\n");
44	fprintf(stderr, "	                     promisc { on | off } |\n");
45	fprintf(stderr, "	                     trailers { on | off } |\n");
46	fprintf(stderr, "	                     txqueuelen PACKETS |\n");
47	fprintf(stderr, "	                     name NEWNAME |\n");
48	fprintf(stderr, "	                     address LLADDR | broadcast LLADDR |\n");
49	fprintf(stderr, "	                     mtu MTU }\n");
50	fprintf(stderr, "       ip link show [ DEVICE ]\n");
51	exit(-1);
52}
53
54static void usage(void)
55{
56	iplink_usage();
57}
58
59static int on_off(char *msg)
60{
61	fprintf(stderr, "Error: argument of \"%s\" must be \"on\" or \"off\"\n", msg);
62	return -1;
63}
64
65static int get_ctl_fd(void)
66{
67	int s_errno;
68	int fd;
69
70	fd = socket(PF_INET, SOCK_DGRAM, 0);
71	if (fd >= 0)
72		return fd;
73	s_errno = errno;
74	fd = socket(PF_PACKET, SOCK_DGRAM, 0);
75	if (fd >= 0)
76		return fd;
77	fd = socket(PF_INET6, SOCK_DGRAM, 0);
78	if (fd >= 0)
79		return fd;
80	errno = s_errno;
81	perror("Cannot create control socket");
82	return -1;
83}
84
85static int do_chflags(const char *dev, __u32 flags, __u32 mask)
86{
87	struct ifreq ifr;
88	int fd;
89	int err;
90
91	strncpy(ifr.ifr_name, dev, IFNAMSIZ);
92	fd = get_ctl_fd();
93	if (fd < 0)
94		return -1;
95	err = ioctl(fd, SIOCGIFFLAGS, &ifr);
96	if (err) {
97		perror("SIOCGIFFLAGS");
98		close(fd);
99		return -1;
100	}
101	if ((ifr.ifr_flags^flags)&mask) {
102		ifr.ifr_flags &= ~mask;
103		ifr.ifr_flags |= mask&flags;
104		err = ioctl(fd, SIOCSIFFLAGS, &ifr);
105		if (err)
106			perror("SIOCSIFFLAGS");
107	}
108	close(fd);
109	return err;
110}
111
112static int do_changename(const char *dev, const char *newdev)
113{
114	struct ifreq ifr;
115	int fd;
116	int err;
117
118	strncpy(ifr.ifr_name, dev, IFNAMSIZ);
119	strncpy(ifr.ifr_newname, newdev, IFNAMSIZ);
120	fd = get_ctl_fd();
121	if (fd < 0)
122		return -1;
123	err = ioctl(fd, SIOCSIFNAME, &ifr);
124	if (err) {
125		perror("SIOCSIFNAME");
126		close(fd);
127		return -1;
128	}
129	close(fd);
130	return err;
131}
132
133static int set_qlen(const char *dev, int qlen)
134{
135	struct ifreq ifr;
136	int s;
137
138	s = get_ctl_fd();
139	if (s < 0)
140		return -1;
141
142	memset(&ifr, 0, sizeof(ifr));
143	strncpy(ifr.ifr_name, dev, IFNAMSIZ);
144	ifr.ifr_qlen = qlen;
145	if (ioctl(s, SIOCSIFTXQLEN, &ifr) < 0) {
146		perror("SIOCSIFXQLEN");
147		close(s);
148		return -1;
149	}
150	close(s);
151
152	return 0;
153}
154
155static int set_mtu(const char *dev, int mtu)
156{
157	struct ifreq ifr;
158	int s;
159
160	s = get_ctl_fd();
161	if (s < 0)
162		return -1;
163
164	memset(&ifr, 0, sizeof(ifr));
165	strncpy(ifr.ifr_name, dev, IFNAMSIZ);
166	ifr.ifr_mtu = mtu;
167	if (ioctl(s, SIOCSIFMTU, &ifr) < 0) {
168		perror("SIOCSIFMTU");
169		close(s);
170		return -1;
171	}
172	close(s);
173
174	return 0;
175}
176
177static int get_address(const char *dev, int *htype)
178{
179	struct ifreq ifr;
180	struct sockaddr_ll me;
181	socklen_t alen;
182	int s;
183
184	s = socket(PF_PACKET, SOCK_DGRAM, 0);
185	if (s < 0) {
186		perror("socket(PF_PACKET)");
187		return -1;
188	}
189
190	memset(&ifr, 0, sizeof(ifr));
191	strncpy(ifr.ifr_name, dev, IFNAMSIZ);
192	if (ioctl(s, SIOCGIFINDEX, &ifr) < 0) {
193		perror("SIOCGIFINDEX");
194		close(s);
195		return -1;
196	}
197
198	memset(&me, 0, sizeof(me));
199	me.sll_family = AF_PACKET;
200	me.sll_ifindex = ifr.ifr_ifindex;
201	me.sll_protocol = htons(ETH_P_LOOP);
202	if (bind(s, (struct sockaddr*)&me, sizeof(me)) == -1) {
203		perror("bind");
204		close(s);
205		return -1;
206	}
207
208	alen = sizeof(me);
209	if (getsockname(s, (struct sockaddr*)&me, &alen) == -1) {
210		perror("getsockname");
211		close(s);
212		return -1;
213	}
214	close(s);
215	*htype = me.sll_hatype;
216	return me.sll_halen;
217}
218
219static int parse_address(const char *dev, int hatype, int halen,
220		char *lla, struct ifreq *ifr)
221{
222	int alen;
223
224	memset(ifr, 0, sizeof(*ifr));
225	strncpy(ifr->ifr_name, dev, IFNAMSIZ);
226	ifr->ifr_hwaddr.sa_family = hatype;
227	alen = ll_addr_a2n(ifr->ifr_hwaddr.sa_data, 14, lla);
228	if (alen < 0)
229		return -1;
230	if (alen != halen) {
231		fprintf(stderr, "Wrong address (%s) length: expected %d bytes\n", lla, halen);
232		return -1;
233	}
234	return 0;
235}
236
237static int set_address(struct ifreq *ifr, int brd)
238{
239	int s;
240
241	s = get_ctl_fd();
242	if (s < 0)
243		return -1;
244	if (ioctl(s, brd?SIOCSIFHWBROADCAST:SIOCSIFHWADDR, ifr) < 0) {
245		perror(brd?"SIOCSIFHWBROADCAST":"SIOCSIFHWADDR");
246		close(s);
247		return -1;
248	}
249	close(s);
250	return 0;
251}
252
253
254static int do_set(int argc, char **argv)
255{
256	char *dev = NULL;
257	__u32 mask = 0;
258	__u32 flags = 0;
259	int qlen = -1;
260	int mtu = -1;
261	char *newaddr = NULL;
262	char *newbrd = NULL;
263	struct ifreq ifr0, ifr1;
264	char *newname = NULL;
265	int htype, halen;
266
267	while (argc > 0) {
268		if (strcmp(*argv, "up") == 0) {
269			mask |= IFF_UP;
270			flags |= IFF_UP;
271		} else if (strcmp(*argv, "down") == 0) {
272			mask |= IFF_UP;
273			flags &= ~IFF_UP;
274		} else if (strcmp(*argv, "name") == 0) {
275			NEXT_ARG();
276			newname = *argv;
277		} else if (matches(*argv, "address") == 0) {
278			NEXT_ARG();
279			newaddr = *argv;
280		} else if (matches(*argv, "broadcast") == 0 ||
281			   strcmp(*argv, "brd") == 0) {
282			NEXT_ARG();
283			newbrd = *argv;
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		} else if (strcmp(*argv, "mtu") == 0) {
293			NEXT_ARG();
294			if (mtu != -1)
295				duparg("mtu", *argv);
296			if (get_integer(&mtu, *argv, 0))
297				invarg("Invalid \"mtu\" value\n", *argv);
298		} else if (strcmp(*argv, "multicast") == 0) {
299			NEXT_ARG();
300			mask |= IFF_MULTICAST;
301			if (strcmp(*argv, "on") == 0) {
302				flags |= IFF_MULTICAST;
303			} else if (strcmp(*argv, "off") == 0) {
304				flags &= ~IFF_MULTICAST;
305			} else
306				return on_off("multicast");
307		} else if (strcmp(*argv, "allmulticast") == 0) {
308			NEXT_ARG();
309			mask |= IFF_ALLMULTI;
310			if (strcmp(*argv, "on") == 0) {
311				flags |= IFF_ALLMULTI;
312			} else if (strcmp(*argv, "off") == 0) {
313				flags &= ~IFF_ALLMULTI;
314			} else
315				return on_off("allmulticast");
316		} else if (strcmp(*argv, "promisc") == 0) {
317			NEXT_ARG();
318			mask |= IFF_PROMISC;
319			if (strcmp(*argv, "on") == 0) {
320				flags |= IFF_PROMISC;
321			} else if (strcmp(*argv, "off") == 0) {
322				flags &= ~IFF_PROMISC;
323			} else
324				return on_off("promisc");
325		} else if (strcmp(*argv, "trailers") == 0) {
326			NEXT_ARG();
327			mask |= IFF_NOTRAILERS;
328			if (strcmp(*argv, "off") == 0) {
329				flags |= IFF_NOTRAILERS;
330			} else if (strcmp(*argv, "on") == 0) {
331				flags &= ~IFF_NOTRAILERS;
332			} else
333				return on_off("trailers");
334		} else if (strcmp(*argv, "arp") == 0) {
335			NEXT_ARG();
336			mask |= IFF_NOARP;
337			if (strcmp(*argv, "on") == 0) {
338				flags &= ~IFF_NOARP;
339			} else if (strcmp(*argv, "off") == 0) {
340				flags |= IFF_NOARP;
341			} else
342				return on_off("noarp");
343#ifdef IFF_DYNAMIC
344		} else if (matches(*argv, "dynamic") == 0) {
345			NEXT_ARG();
346			mask |= IFF_DYNAMIC;
347			if (strcmp(*argv, "on") == 0) {
348				flags |= IFF_DYNAMIC;
349			} else if (strcmp(*argv, "off") == 0) {
350				flags &= ~IFF_DYNAMIC;
351			} else
352				return on_off("dynamic");
353#endif
354		} else {
355                        if (strcmp(*argv, "dev") == 0) {
356				NEXT_ARG();
357			}
358			if (matches(*argv, "help") == 0)
359				usage();
360			if (dev)
361				duparg2("dev", *argv);
362			dev = *argv;
363		}
364		argc--; argv++;
365	}
366
367	if (!dev) {
368		fprintf(stderr, "Not enough of information: \"dev\" argument is required.\n");
369		exit(-1);
370	}
371
372	if (newaddr || newbrd) {
373		halen = get_address(dev, &htype);
374		if (halen < 0)
375			return -1;
376		if (newaddr) {
377			if (parse_address(dev, htype, halen, newaddr, &ifr0) < 0)
378				return -1;
379		}
380		if (newbrd) {
381			if (parse_address(dev, htype, halen, newbrd, &ifr1) < 0)
382				return -1;
383		}
384	}
385
386	if (newname && strcmp(dev, newname)) {
387		if (do_changename(dev, newname) < 0)
388			return -1;
389		dev = newname;
390	}
391	if (qlen != -1) {
392		if (set_qlen(dev, qlen) < 0)
393			return -1;
394	}
395	if (mtu != -1) {
396		if (set_mtu(dev, mtu) < 0)
397			return -1;
398	}
399	if (newaddr || newbrd) {
400		if (newbrd) {
401			if (set_address(&ifr1, 1) < 0)
402				return -1;
403		}
404		if (newaddr) {
405			if (set_address(&ifr0, 0) < 0)
406				return -1;
407		}
408	}
409	if (mask)
410		return do_chflags(dev, flags, mask);
411	return 0;
412}
413
414int do_iplink(int argc, char **argv)
415{
416	if (argc > 0) {
417		if (matches(*argv, "set") == 0)
418			return do_set(argc-1, argv+1);
419		if (matches(*argv, "show") == 0 ||
420		    matches(*argv, "lst") == 0 ||
421		    matches(*argv, "list") == 0)
422			return ipaddr_list_link(argc-1, argv+1);
423		if (matches(*argv, "help") == 0)
424			usage();
425	} else
426		return ipaddr_list_link(0, NULL);
427
428	fprintf(stderr, "Command \"%s\" is unknown, try \"ip link help\".\n", *argv);
429	exit(-1);
430}
431