interface.c revision 1.21 
1/*	$OpenBSD: interface.c,v 1.21 2015/03/21 18:25:08 renato 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 if_addr		*if_addr;
169
170	if (iface->state == IF_STA_ACTIVE)
171		if_act_reset(iface);
172
173	log_debug("if_del: interface %s", iface->name);
174
175	while ((if_addr = LIST_FIRST(&iface->addr_list)) != NULL)
176		LIST_REMOVE(if_addr, iface_entry);
177
178	free(iface);
179}
180
181void
182if_init(struct ldpd_conf *xconf, struct iface *iface)
183{
184	/* set event handlers for interface */
185	evtimer_set(&iface->hello_timer, if_hello_timer, iface);
186
187	iface->discovery_fd = xconf->ldp_discovery_socket;
188}
189
190struct iface *
191if_lookup(u_short ifindex)
192{
193	struct iface *iface;
194
195	LIST_FOREACH(iface, &leconf->iface_list, entry)
196		if (iface->ifindex == ifindex)
197			return (iface);
198
199	return (NULL);
200}
201
202/* timers */
203/* ARGSUSED */
204void
205if_hello_timer(int fd, short event, void *arg)
206{
207	struct iface *iface = arg;
208	struct timeval tv;
209
210	send_hello(HELLO_LINK, iface, NULL);
211
212	/* reschedule hello_timer */
213	timerclear(&tv);
214	tv.tv_sec = iface->hello_interval;
215	if (evtimer_add(&iface->hello_timer, &tv) == -1)
216		fatal("if_hello_timer");
217}
218
219void
220if_start_hello_timer(struct iface *iface)
221{
222	struct timeval tv;
223
224	send_hello(HELLO_LINK, iface, NULL);
225
226	timerclear(&tv);
227	tv.tv_sec = iface->hello_interval;
228	if (evtimer_add(&iface->hello_timer, &tv) == -1)
229		fatal("if_start_hello_timer");
230}
231
232void
233if_stop_hello_timer(struct iface *iface)
234{
235	if (evtimer_pending(&iface->hello_timer, NULL) &&
236	    evtimer_del(&iface->hello_timer) == -1)
237		fatal("if_stop_hello_timer");
238}
239
240/* actions */
241int
242if_act_start(struct iface *iface)
243{
244	struct in_addr		 addr;
245	struct timeval		 now;
246
247	gettimeofday(&now, NULL);
248	iface->uptime = now.tv_sec;
249
250	inet_aton(AllRouters, &addr);
251	if (if_join_group(iface, &addr))
252		return (-1);
253
254	/* hello timer needs to be started in any case */
255	if_start_hello_timer(iface);
256	return (0);
257}
258
259int
260if_act_reset(struct iface *iface)
261{
262	struct in_addr		 addr;
263	struct adj		*adj;
264
265	while ((adj = LIST_FIRST(&iface->adj_list)) != NULL) {
266		LIST_REMOVE(adj, iface_entry);
267		adj_del(adj);
268	}
269
270	if_stop_hello_timer(iface);
271
272	/* try to cleanup */
273	inet_aton(AllRouters, &addr);
274	if_leave_group(iface, &addr);
275
276	return (0);
277}
278
279int
280if_act_update(struct iface *iface)
281{
282	int ret;
283
284	if (iface->state == IF_STA_DOWN) {
285		if (!((iface->flags & IFF_UP) &&
286		    LINK_STATE_IS_UP(iface->linkstate)))
287			return (0);
288
289		if (LIST_EMPTY(&iface->addr_list))
290			return (0);
291
292		iface->state = IF_STA_ACTIVE;
293		ret = if_act_start(iface);
294	} else {
295		if (!LIST_EMPTY(&iface->addr_list))
296			return (0);
297
298		iface->state = IF_STA_DOWN;
299		ret = if_act_reset(iface);
300	}
301
302	return (ret);
303}
304
305struct ctl_iface *
306if_to_ctl(struct iface *iface)
307{
308	static struct ctl_iface	 ictl;
309	struct timeval		 now;
310	struct adj		*adj;
311
312	memcpy(ictl.name, iface->name, sizeof(ictl.name));
313	ictl.ifindex = iface->ifindex;
314	ictl.state = iface->state;
315	ictl.hello_holdtime = iface->hello_holdtime;
316	ictl.hello_interval = iface->hello_interval;
317	ictl.flags = iface->flags;
318	ictl.type = iface->type;
319	ictl.linkstate = iface->linkstate;
320	ictl.mediatype = iface->media_type;
321
322	gettimeofday(&now, NULL);
323	if (iface->state != IF_STA_DOWN &&
324	    iface->uptime != 0) {
325		ictl.uptime = now.tv_sec - iface->uptime;
326	} else
327		ictl.uptime = 0;
328
329	ictl.adj_cnt = 0;
330	LIST_FOREACH(adj, &iface->adj_list, iface_entry)
331		ictl.adj_cnt++;
332
333	return (&ictl);
334}
335
336/* misc */
337int
338if_set_mcast_ttl(int fd, u_int8_t ttl)
339{
340	if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_TTL,
341	    (char *)&ttl, sizeof(ttl)) < 0) {
342		log_warn("if_set_mcast_ttl: error setting "
343		    "IP_MULTICAST_TTL to %d", ttl);
344		return (-1);
345	}
346
347	return (0);
348}
349
350int
351if_set_tos(int fd, int tos)
352{
353	if (setsockopt(fd, IPPROTO_IP, IP_TOS, (int *)&tos, sizeof(tos)) < 0) {
354		log_warn("if_set_tos: error setting IP_TOS to 0x%x", tos);
355		return (-1);
356	}
357
358	return (0);
359}
360
361int
362if_set_recvif(int fd, int enable)
363{
364	if (setsockopt(fd, IPPROTO_IP, IP_RECVIF, &enable,
365	    sizeof(enable)) < 0) {
366		log_warn("if_set_recvif: error setting IP_RECVIF");
367		return (-1);
368	}
369	return (0);
370}
371
372void
373if_set_recvbuf(int fd)
374{
375	int	bsize;
376
377	bsize = 65535;
378	while (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &bsize,
379	    sizeof(bsize)) == -1)
380		bsize /= 2;
381}
382
383int
384if_set_reuse(int fd, int enable)
385{
386	if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &enable,
387	    sizeof(int)) < 0) {
388		log_warn("if_set_reuse: error setting SO_REUSEADDR");
389		return (-1);
390	}
391
392	return (0);
393}
394
395/*
396 * only one JOIN or DROP per interface and address is allowed so we need
397 * to keep track of what is added and removed.
398 */
399struct if_group_count {
400	LIST_ENTRY(if_group_count)	entry;
401	struct in_addr			addr;
402	unsigned int			ifindex;
403	int				count;
404};
405
406LIST_HEAD(,if_group_count) ifglist = LIST_HEAD_INITIALIZER(ifglist);
407
408int
409if_join_group(struct iface *iface, struct in_addr *addr)
410{
411	struct ip_mreq		 mreq;
412	struct if_group_count	*ifg;
413	struct if_addr		*if_addr;
414
415	LIST_FOREACH(ifg, &ifglist, entry)
416		if (iface->ifindex == ifg->ifindex &&
417		    addr->s_addr == ifg->addr.s_addr)
418			break;
419	if (ifg == NULL) {
420		if ((ifg = calloc(1, sizeof(*ifg))) == NULL)
421			fatal("if_join_group");
422		ifg->addr.s_addr = addr->s_addr;
423		ifg->ifindex = iface->ifindex;
424		LIST_INSERT_HEAD(&ifglist, ifg, entry);
425	}
426
427	if (ifg->count++ != 0)
428		/* already joined */
429		return (0);
430
431	if_addr = LIST_FIRST(&iface->addr_list);
432	mreq.imr_multiaddr.s_addr = addr->s_addr;
433	mreq.imr_interface.s_addr = if_addr->addr.s_addr;
434
435	if (setsockopt(iface->discovery_fd, IPPROTO_IP,
436	    IP_ADD_MEMBERSHIP, (void *)&mreq, sizeof(mreq)) < 0) {
437		log_warn("if_join_group: error IP_ADD_MEMBERSHIP, "
438		    "interface %s address %s", iface->name,
439		    inet_ntoa(*addr));
440		LIST_REMOVE(ifg, entry);
441		free(ifg);
442		return (-1);
443	}
444	return (0);
445}
446
447int
448if_leave_group(struct iface *iface, struct in_addr *addr)
449{
450	struct ip_mreq		 mreq;
451	struct if_group_count	*ifg;
452	struct if_addr		*if_addr;
453
454	LIST_FOREACH(ifg, &ifglist, entry)
455		if (iface->ifindex == ifg->ifindex &&
456		    addr->s_addr == ifg->addr.s_addr)
457			break;
458
459	/* if interface is not found just try to drop membership */
460	if (ifg) {
461		if (--ifg->count != 0)
462			/* others still joined */
463			return (0);
464
465		LIST_REMOVE(ifg, entry);
466		free(ifg);
467	}
468
469	if_addr = LIST_FIRST(&iface->addr_list);
470	if (!if_addr)
471		return (0);
472
473	mreq.imr_multiaddr.s_addr = addr->s_addr;
474	mreq.imr_interface.s_addr = if_addr->addr.s_addr;
475
476	if (setsockopt(iface->discovery_fd, IPPROTO_IP,
477	    IP_DROP_MEMBERSHIP, (void *)&mreq, sizeof(mreq)) < 0) {
478		log_warn("if_leave_group: error IP_DROP_MEMBERSHIP, "
479		    "interface %s address %s", iface->name,
480		    inet_ntoa(*addr));
481		return (-1);
482	}
483
484	return (0);
485}
486
487int
488if_set_mcast(struct iface *iface)
489{
490	struct if_addr		*if_addr;
491
492	if_addr = LIST_FIRST(&iface->addr_list);
493
494	if (setsockopt(iface->discovery_fd, IPPROTO_IP, IP_MULTICAST_IF,
495	    &if_addr->addr.s_addr, sizeof(if_addr->addr.s_addr)) < 0) {
496		log_debug("if_set_mcast: error setting "
497		    "IP_MULTICAST_IF, interface %s", iface->name);
498		return (-1);
499	}
500
501	return (0);
502}
503
504int
505if_set_mcast_loop(int fd)
506{
507	u_int8_t	loop = 0;
508
509	if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP,
510	    (char *)&loop, sizeof(loop)) < 0) {
511		log_warn("if_set_mcast_loop: error setting IP_MULTICAST_LOOP");
512		return (-1);
513	}
514
515	return (0);
516}
517