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, char *lla, struct ifreq *ifr)
220{
221	int alen;
222
223	memset(ifr, 0, sizeof(*ifr));
224	strncpy(ifr->ifr_name, dev, IFNAMSIZ);
225	ifr->ifr_hwaddr.sa_family = hatype;
226	alen = ll_addr_a2n(ifr->ifr_hwaddr.sa_data, 14, lla);
227	if (alen < 0)
228		return -1;
229	if (alen != halen) {
230		fprintf(stderr, "Wrong address (%s) length: expected %d bytes\n", lla, halen);
231		return -1;
232	}
233	return 0;
234}
235
236static int set_address(struct ifreq *ifr, int brd)
237{
238	int s;
239
240	s = get_ctl_fd();
241	if (s < 0)
242		return -1;
243	if (ioctl(s, brd?SIOCSIFHWBROADCAST:SIOCSIFHWADDR, ifr) < 0) {
244		perror(brd?"SIOCSIFHWBROADCAST":"SIOCSIFHWADDR");
245		close(s);
246		return -1;
247	}
248	close(s);
249	return 0;
250}
251
252
253static int do_set(int argc, char **argv)
254{
255	char *dev = NULL;
256	__u32 mask = 0;
257	__u32 flags = 0;
258	int qlen = -1;
259	int mtu = -1;
260	char *newaddr = NULL;
261	char *newbrd = NULL;
262	struct ifreq ifr0, ifr1;
263	char *newname = NULL;
264	int htype, halen;
265
266	while (argc > 0) {
267		if (strcmp(*argv, "up") == 0) {
268			mask |= IFF_UP;
269			flags |= IFF_UP;
270		} else if (strcmp(*argv, "down") == 0) {
271			mask |= IFF_UP;
272			flags &= ~IFF_UP;
273		} else if (strcmp(*argv, "name") == 0) {
274			NEXT_ARG();
275			newname = *argv;
276		} else if (matches(*argv, "address") == 0) {
277			NEXT_ARG();
278			newaddr = *argv;
279		} else if (matches(*argv, "broadcast") == 0 ||
280			   strcmp(*argv, "brd") == 0) {
281			NEXT_ARG();
282			newbrd = *argv;
283		} else if (matches(*argv, "txqueuelen") == 0 ||
284			   strcmp(*argv, "qlen") == 0 ||
285			   matches(*argv, "txqlen") == 0) {
286			NEXT_ARG();
287			if (qlen != -1)
288				duparg("txqueuelen", *argv);
289			if (get_integer(&qlen,  *argv, 0))
290				invarg("Invalid \"txqueuelen\" value\n", *argv);
291		} else if (strcmp(*argv, "mtu") == 0) {
292			NEXT_ARG();
293			if (mtu != -1)
294				duparg("mtu", *argv);
295			if (get_integer(&mtu, *argv, 0))
296				invarg("Invalid \"mtu\" value\n", *argv);
297		} else if (strcmp(*argv, "multicast") == 0) {
298			NEXT_ARG();
299			mask |= IFF_MULTICAST;
300			if (strcmp(*argv, "on") == 0) {
301				flags |= IFF_MULTICAST;
302			} else if (strcmp(*argv, "off") == 0) {
303				flags &= ~IFF_MULTICAST;
304			} else
305				return on_off("multicast");
306		} else if (strcmp(*argv, "allmulticast") == 0) {
307			NEXT_ARG();
308			mask |= IFF_ALLMULTI;
309			if (strcmp(*argv, "on") == 0) {
310				flags |= IFF_ALLMULTI;
311			} else if (strcmp(*argv, "off") == 0) {
312				flags &= ~IFF_ALLMULTI;
313			} else
314				return on_off("allmulticast");
315		} else if (strcmp(*argv, "promisc") == 0) {
316			NEXT_ARG();
317			mask |= IFF_PROMISC;
318			if (strcmp(*argv, "on") == 0) {
319				flags |= IFF_PROMISC;
320			} else if (strcmp(*argv, "off") == 0) {
321				flags &= ~IFF_PROMISC;
322			} else
323				return on_off("promisc");
324		} else if (strcmp(*argv, "trailers") == 0) {
325			NEXT_ARG();
326			mask |= IFF_NOTRAILERS;
327			if (strcmp(*argv, "off") == 0) {
328				flags |= IFF_NOTRAILERS;
329			} else if (strcmp(*argv, "on") == 0) {
330				flags &= ~IFF_NOTRAILERS;
331			} else
332				return on_off("trailers");
333		} else if (strcmp(*argv, "arp") == 0) {
334			NEXT_ARG();
335			mask |= IFF_NOARP;
336			if (strcmp(*argv, "on") == 0) {
337				flags &= ~IFF_NOARP;
338			} else if (strcmp(*argv, "off") == 0) {
339				flags |= IFF_NOARP;
340			} else
341				return on_off("noarp");
342#ifdef IFF_DYNAMIC
343		} else if (matches(*argv, "dynamic") == 0) {
344			NEXT_ARG();
345			mask |= IFF_DYNAMIC;
346			if (strcmp(*argv, "on") == 0) {
347				flags |= IFF_DYNAMIC;
348			} else if (strcmp(*argv, "off") == 0) {
349				flags &= ~IFF_DYNAMIC;
350			} else
351				return on_off("dynamic");
352#endif
353		} else {
354                        if (strcmp(*argv, "dev") == 0) {
355				NEXT_ARG();
356			}
357			if (matches(*argv, "help") == 0)
358				usage();
359			if (dev)
360				duparg2("dev", *argv);
361			dev = *argv;
362		}
363		argc--; argv++;
364	}
365
366	if (!dev) {
367		fprintf(stderr, "Not enough of information: \"dev\" argument is required.\n");
368		exit(-1);
369	}
370
371	if (newaddr || newbrd) {
372		halen = get_address(dev, &htype);
373		if (halen < 0)
374			return -1;
375		if (newaddr) {
376			if (parse_address(dev, htype, halen, newaddr, &ifr0) < 0)
377				return -1;
378		}
379		if (newbrd) {
380			if (parse_address(dev, htype, halen, newbrd, &ifr1) < 0)
381				return -1;
382		}
383	}
384
385	if (newname && strcmp(dev, newname)) {
386		if (do_changename(dev, newname) < 0)
387			return -1;
388		dev = newname;
389	}
390	if (qlen != -1) {
391		if (set_qlen(dev, qlen) < 0)
392			return -1;
393	}
394	if (mtu != -1) {
395		if (set_mtu(dev, mtu) < 0)
396			return -1;
397	}
398	if (newaddr || newbrd) {
399		if (newbrd) {
400			if (set_address(&ifr1, 1) < 0)
401				return -1;
402		}
403		if (newaddr) {
404			if (set_address(&ifr0, 0) < 0)
405				return -1;
406		}
407	}
408	if (mask)
409		return do_chflags(dev, flags, mask);
410	return 0;
411}
412
413int do_iplink(int argc, char **argv)
414{
415	if (argc > 0) {
416		if (matches(*argv, "set") == 0)
417			return do_set(argc-1, argv+1);
418		if (matches(*argv, "show") == 0 ||
419		    matches(*argv, "lst") == 0 ||
420		    matches(*argv, "list") == 0)
421			return ipaddr_list_link(argc-1, argv+1);
422		if (matches(*argv, "help") == 0)
423			usage();
424	} else
425		return ipaddr_list_link(0, NULL);
426
427	fprintf(stderr, "Command \"%s\" is unknown, try \"ip link help\".\n", *argv);
428	exit(-1);
429}
430