interface.c revision 1.18 
1/*	$OpenBSD: interface.c,v 1.18 2013/06/04 02:28:27 claudio Exp $ */
2
3/*
4 * Copyright (c) 2005 Claudio Jeker <claudio@openbsd.org>
5 * Copyright (c) 2004, 2005, 2008 Esben Norby <norby@openbsd.org>
6 *
7 * Permission to use, copy, modify, and distribute this software for any
8 * purpose with or without fee is hereby granted, provided that the above
9 * copyright notice and this permission notice appear in all copies.
10 *
11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 */
19
20#include <sys/types.h>
21#include <sys/ioctl.h>
22#include <sys/time.h>
23#include <sys/socket.h>
24#include <netinet/in.h>
25#include <arpa/inet.h>
26#include <net/if.h>
27#include <net/if_types.h>
28#include <fcntl.h>
29#include <ctype.h>
30#include <err.h>
31#include <stdio.h>
32#include <stdlib.h>
33#include <unistd.h>
34#include <string.h>
35#include <event.h>
36
37#include "ldpd.h"
38#include "ldp.h"
39#include "log.h"
40#include "ldpe.h"
41
42extern struct ldpd_conf        *leconf;
43
44int		 if_act_start(struct iface *);
45int		 if_act_reset(struct iface *);
46int		 if_act_update(struct iface *);
47void		 if_hello_timer(int, short, void *);
48void		 if_start_hello_timer(struct iface *);
49void		 if_stop_hello_timer(struct iface *);
50struct nbr	*if_elect(struct nbr *, struct nbr *);
51
52struct {
53	int			state;
54	enum iface_event	event;
55	enum iface_action	action;
56	int			new_state;
57} iface_fsm[] = {
58    /* current state	event that happened	action to take	resulting state */
59    {IF_STA_DOWN,	IF_EVT_DOWN,		IF_ACT_NOTHING,	0},
60    {IF_STA_DOWN,	IF_EVT_UP,		IF_ACT_UPDATE,	0},
61    {IF_STA_DOWN,	IF_EVT_NEWADDR,		IF_ACT_UPDATE,	0},
62    {IF_STA_DOWN,	IF_EVT_DELADDR,		IF_ACT_NOTHING,	0},
63    {IF_STA_ACTIVE,	IF_EVT_DOWN,		IF_ACT_RST,	IF_STA_DOWN},
64    {IF_STA_ACTIVE,	IF_EVT_NEWADDR,		IF_ACT_NOTHING,	0},
65    {IF_STA_ACTIVE,	IF_EVT_DELADDR,		IF_ACT_UPDATE,	0},
66    {-1,		IF_EVT_NOTHING,		IF_ACT_NOTHING,	0},
67};
68
69const char * const if_event_names[] = {
70	"NOTHING",
71	"UP",
72	"DOWN",
73	"NEWADDR",
74	"DELADDR"
75};
76
77const char * const if_action_names[] = {
78	"NOTHING",
79	"UPDATE",
80	"RESET"
81};
82
83int
84if_fsm(struct iface *iface, enum iface_event event)
85{
86	int	old_state;
87	int	new_state = 0;
88	int	i, ret = 0;
89
90	old_state = iface->state;
91
92	for (i = 0; iface_fsm[i].state != -1; i++)
93		if ((iface_fsm[i].state & old_state) &&
94		    (iface_fsm[i].event == event)) {
95			new_state = iface_fsm[i].new_state;
96			break;
97		}
98
99	if (iface_fsm[i].state == -1) {
100		/* event outside of the defined fsm, ignore it. */
101		log_debug("if_fsm: interface %s, "
102		    "event %s not expected in state %s", iface->name,
103		    if_event_names[event], if_state_name(old_state));
104		return (0);
105	}
106
107	switch (iface_fsm[i].action) {
108	case IF_ACT_UPDATE:
109		ret = if_act_update(iface);
110		break;
111	case IF_ACT_RST:
112		ret = if_act_reset(iface);
113		break;
114	case IF_ACT_NOTHING:
115		/* do nothing */
116		break;
117	}
118
119	if (ret) {
120		log_debug("if_fsm: error changing state for interface %s, "
121		    "event %s, state %s", iface->name, if_event_names[event],
122		    if_state_name(old_state));
123		return (-1);
124	}
125
126	if (new_state != 0)
127		iface->state = new_state;
128
129	log_debug("if_fsm: event %s resulted in action %s and changing "
130	    "state for interface %s from %s to %s",
131	    if_event_names[event], if_action_names[iface_fsm[i].action],
132	    iface->name, if_state_name(old_state), if_state_name(iface->state));
133
134	return (ret);
135}
136
137struct iface *
138if_new(struct kif *kif)
139{
140	struct iface		*iface;
141
142	if ((iface = calloc(1, sizeof(*iface))) == NULL)
143		err(1, "if_new: calloc");
144
145	iface->state = IF_STA_DOWN;
146
147	strlcpy(iface->name, kif->ifname, sizeof(iface->name));
148
149	/* get type */
150	if (kif->flags & IFF_POINTOPOINT)
151		iface->type = IF_TYPE_POINTOPOINT;
152	if (kif->flags & IFF_BROADCAST &&
153	    kif->flags & IFF_MULTICAST)
154		iface->type = IF_TYPE_BROADCAST;
155
156	/* get index and flags */
157	iface->ifindex = kif->ifindex;
158	iface->flags = kif->flags;
159	iface->linkstate = kif->link_state;
160	iface->media_type = kif->media_type;
161
162	return (iface);
163}
164
165void
166if_del(struct iface *iface)
167{
168	struct adj		*adj;
169	struct if_addr		*if_addr;
170
171	log_debug("if_del: interface %s", iface->name);
172
173	if_stop_hello_timer(iface);
174
175	while ((adj = LIST_FIRST(&iface->adj_list)) != NULL) {
176		LIST_REMOVE(adj, iface_entry);
177		adj_del(adj);
178	}
179	while ((if_addr = LIST_FIRST(&iface->addr_list)) != NULL)
180		LIST_REMOVE(if_addr, iface_entry);
181
182	free(iface);
183}
184
185void
186if_init(struct ldpd_conf *xconf, struct iface *iface)
187{
188	/* set event handlers for interface */
189	evtimer_set(&iface->hello_timer, if_hello_timer, iface);
190
191	iface->discovery_fd = xconf->ldp_discovery_socket;
192}
193
194struct iface *
195if_lookup(u_short ifindex)
196{
197	struct iface *iface;
198
199	LIST_FOREACH(iface, &leconf->iface_list, entry)
200		if (iface->ifindex == ifindex)
201			return (iface);
202
203	return (NULL);
204}
205
206/* timers */
207/* ARGSUSED */
208void
209if_hello_timer(int fd, short event, void *arg)
210{
211	struct iface *iface = arg;
212	struct timeval tv;
213
214	send_hello(HELLO_LINK, iface, NULL);
215
216	/* reschedule hello_timer */
217	timerclear(&tv);
218	tv.tv_sec = iface->hello_interval;
219	if (evtimer_add(&iface->hello_timer, &tv) == -1)
220		fatal("if_hello_timer");
221}
222
223void
224if_start_hello_timer(struct iface *iface)
225{
226	struct timeval tv;
227
228	timerclear(&tv);
229	tv.tv_sec = iface->hello_interval;
230	if (evtimer_add(&iface->hello_timer, &tv) == -1)
231		fatal("if_start_hello_timer");
232}
233
234void
235if_stop_hello_timer(struct iface *iface)
236{
237	if (evtimer_pending(&iface->hello_timer, NULL) &&
238	    evtimer_del(&iface->hello_timer) == -1)
239		fatal("if_stop_hello_timer");
240}
241
242/* actions */
243int
244if_act_start(struct iface *iface)
245{
246	struct in_addr		 addr;
247	struct timeval		 now;
248
249	gettimeofday(&now, NULL);
250	iface->uptime = now.tv_sec;
251
252	inet_aton(AllRouters, &addr);
253	if (if_join_group(iface, &addr))
254		return (-1);
255
256	/* hello timer needs to be started in any case */
257	if_start_hello_timer(iface);
258	return (0);
259}
260
261int
262if_act_reset(struct iface *iface)
263{
264	struct in_addr		 addr;
265
266	if_stop_hello_timer(iface);
267
268	/* try to cleanup */
269	inet_aton(AllRouters, &addr);
270	if_leave_group(iface, &addr);
271
272	return (0);
273}
274
275int
276if_act_update(struct iface *iface)
277{
278	int ret;
279
280	if (iface->state == IF_STA_DOWN) {
281		if (!((iface->flags & IFF_UP) &&
282		    LINK_STATE_IS_UP(iface->linkstate)))
283			return (0);
284
285		if (LIST_EMPTY(&iface->addr_list))
286			return (0);
287
288		iface->state = IF_STA_ACTIVE;
289		ret = if_act_start(iface);
290	} else {
291		if (!LIST_EMPTY(&iface->addr_list))
292			return (0);
293
294		iface->state = IF_STA_DOWN;
295		ret = if_act_reset(iface);
296	}
297
298	return (ret);
299}
300
301struct ctl_iface *
302if_to_ctl(struct iface *iface)
303{
304	static struct ctl_iface	 ictl;
305	struct timeval		 now;
306	struct adj		*adj;
307
308	memcpy(ictl.name, iface->name, sizeof(ictl.name));
309	ictl.ifindex = iface->ifindex;
310	ictl.state = iface->state;
311	ictl.hello_holdtime = iface->hello_holdtime;
312	ictl.hello_interval = iface->hello_interval;
313	ictl.flags = iface->flags;
314	ictl.type = iface->type;
315	ictl.linkstate = iface->linkstate;
316	ictl.mediatype = iface->media_type;
317
318	gettimeofday(&now, NULL);
319	if (iface->state != IF_STA_DOWN &&
320	    iface->uptime != 0) {
321		ictl.uptime = now.tv_sec - iface->uptime;
322	} else
323		ictl.uptime = 0;
324
325	ictl.adj_cnt = 0;
326	LIST_FOREACH(adj, &iface->adj_list, iface_entry)
327		ictl.adj_cnt++;
328
329	return (&ictl);
330}
331
332/* misc */
333int
334if_set_mcast_ttl(int fd, u_int8_t ttl)
335{
336	if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_TTL,
337	    (char *)&ttl, sizeof(ttl)) < 0) {
338		log_warn("if_set_mcast_ttl: error setting "
339		    "IP_MULTICAST_TTL to %d", ttl);
340		return (-1);
341	}
342
343	return (0);
344}
345
346int
347if_set_tos(int fd, int tos)
348{
349	if (setsockopt(fd, IPPROTO_IP, IP_TOS, (int *)&tos, sizeof(tos)) < 0) {
350		log_warn("if_set_tos: error setting IP_TOS to 0x%x", tos);
351		return (-1);
352	}
353
354	return (0);
355}
356
357int
358if_set_recvif(int fd, int enable)
359{
360	if (setsockopt(fd, IPPROTO_IP, IP_RECVIF, &enable,
361	    sizeof(enable)) < 0) {
362		log_warn("if_set_recvif: error setting IP_RECVIF");
363		return (-1);
364	}
365	return (0);
366}
367
368void
369if_set_recvbuf(int fd)
370{
371	int	bsize;
372
373	bsize = 65535;
374	while (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &bsize,
375	    sizeof(bsize)) == -1)
376		bsize /= 2;
377}
378
379int
380if_set_reuse(int fd, int enable)
381{
382	if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &enable,
383	    sizeof(int)) < 0) {
384		log_warn("if_set_reuse: error setting SO_REUSEADDR");
385		return (-1);
386	}
387
388	return (0);
389}
390
391/*
392 * only one JOIN or DROP per interface and address is allowed so we need
393 * to keep track of what is added and removed.
394 */
395struct if_group_count {
396	LIST_ENTRY(if_group_count)	entry;
397	struct in_addr			addr;
398	unsigned int			ifindex;
399	int				count;
400};
401
402LIST_HEAD(,if_group_count) ifglist = LIST_HEAD_INITIALIZER(ifglist);
403
404int
405if_join_group(struct iface *iface, struct in_addr *addr)
406{
407	struct ip_mreq		 mreq;
408	struct if_group_count	*ifg;
409	struct if_addr		*if_addr;
410
411	LIST_FOREACH(ifg, &ifglist, entry)
412		if (iface->ifindex == ifg->ifindex &&
413		    addr->s_addr == ifg->addr.s_addr)
414			break;
415	if (ifg == NULL) {
416		if ((ifg = calloc(1, sizeof(*ifg))) == NULL)
417			fatal("if_join_group");
418		ifg->addr.s_addr = addr->s_addr;
419		ifg->ifindex = iface->ifindex;
420		LIST_INSERT_HEAD(&ifglist, ifg, entry);
421	}
422
423	if (ifg->count++ != 0)
424		/* already joined */
425		return (0);
426
427	if_addr = LIST_FIRST(&iface->addr_list);
428	mreq.imr_multiaddr.s_addr = addr->s_addr;
429	mreq.imr_interface.s_addr = if_addr->addr.s_addr;
430
431	if (setsockopt(iface->discovery_fd, IPPROTO_IP,
432	    IP_ADD_MEMBERSHIP, (void *)&mreq, sizeof(mreq)) < 0) {
433		log_warn("if_join_group: error IP_ADD_MEMBERSHIP, "
434		    "interface %s address %s", iface->name,
435		    inet_ntoa(*addr));
436		LIST_REMOVE(ifg, entry);
437		free(ifg);
438		return (-1);
439	}
440	return (0);
441}
442
443int
444if_leave_group(struct iface *iface, struct in_addr *addr)
445{
446	struct ip_mreq		 mreq;
447	struct if_group_count	*ifg;
448	struct if_addr		*if_addr;
449
450	LIST_FOREACH(ifg, &ifglist, entry)
451		if (iface->ifindex == ifg->ifindex &&
452		    addr->s_addr == ifg->addr.s_addr)
453			break;
454
455	/* if interface is not found just try to drop membership */
456	if (ifg) {
457		if (--ifg->count != 0)
458			/* others still joined */
459			return (0);
460
461		LIST_REMOVE(ifg, entry);
462		free(ifg);
463	}
464
465	if_addr = LIST_FIRST(&iface->addr_list);
466	if (!if_addr)
467		return (0);
468
469	mreq.imr_multiaddr.s_addr = addr->s_addr;
470	mreq.imr_interface.s_addr = if_addr->addr.s_addr;
471
472	if (setsockopt(iface->discovery_fd, IPPROTO_IP,
473	    IP_DROP_MEMBERSHIP, (void *)&mreq, sizeof(mreq)) < 0) {
474		log_warn("if_leave_group: error IP_DROP_MEMBERSHIP, "
475		    "interface %s address %s", iface->name,
476		    inet_ntoa(*addr));
477		return (-1);
478	}
479
480	return (0);
481}
482
483int
484if_set_mcast(struct iface *iface)
485{
486	struct if_addr		*if_addr;
487
488	if_addr = LIST_FIRST(&iface->addr_list);
489
490	if (setsockopt(iface->discovery_fd, IPPROTO_IP, IP_MULTICAST_IF,
491	    &if_addr->addr.s_addr, sizeof(if_addr->addr.s_addr)) < 0) {
492		log_debug("if_set_mcast: error setting "
493		    "IP_MULTICAST_IF, interface %s", iface->name);
494		return (-1);
495	}
496
497	return (0);
498}
499
500int
501if_set_mcast_loop(int fd)
502{
503	u_int8_t	loop = 0;
504
505	if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP,
506	    (char *)&loop, sizeof(loop)) < 0) {
507		log_warn("if_set_mcast_loop: error setting IP_MULTICAST_LOOP");
508		return (-1);
509	}
510
511	return (0);
512}
513