xref: /freebsd/contrib/bsnmp/snmp_mibII/mibII.c (revision f6a3b357e9be4c6423c85eff9a847163a0d307c8)
1 /*
2  * Copyright (c) 2001-2003
3  *	Fraunhofer Institute for Open Communication Systems (FhG Fokus).
4  *	All rights reserved.
5  *
6  * Author: Harti Brandt <harti@freebsd.org>
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * $Begemot: mibII.c 516 2006-10-27 15:54:02Z brandt_h $
30  *
31  * Implementation of the standard interfaces and ip MIB.
32  */
33 #include "mibII.h"
34 #include "mibII_oid.h"
35 #include <net/if.h>
36 #include <net/if_types.h>
37 
38 
39 /*****************************/
40 
41 /* our module */
42 static struct lmodule *module;
43 
44 /* routing socket */
45 static int route;
46 static void *route_fd;
47 
48 /* if-index allocator */
49 static uint32_t next_if_index = 1;
50 
51 /* currently fetching the arp table */
52 static int in_update_arp;
53 
54 /* OR registrations */
55 static u_int ifmib_reg;
56 static u_int ipmib_reg;
57 static u_int tcpmib_reg;
58 static u_int udpmib_reg;
59 static u_int ipForward_reg;
60 
61 /*****************************/
62 
63 /* list of all IP addresses */
64 struct mibifa_list mibifa_list = TAILQ_HEAD_INITIALIZER(mibifa_list);
65 
66 /* list of all interfaces */
67 struct mibif_list mibif_list = TAILQ_HEAD_INITIALIZER(mibif_list);
68 
69 /* list of dynamic interface names */
70 struct mibdynif_list mibdynif_list = SLIST_HEAD_INITIALIZER(mibdynif_list);
71 
72 /* list of all interface index mappings */
73 struct mibindexmap_list mibindexmap_list = STAILQ_HEAD_INITIALIZER(mibindexmap_list);
74 
75 /* list of all stacking entries */
76 struct mibifstack_list mibifstack_list = TAILQ_HEAD_INITIALIZER(mibifstack_list);
77 
78 /* list of all receive addresses */
79 struct mibrcvaddr_list mibrcvaddr_list = TAILQ_HEAD_INITIALIZER(mibrcvaddr_list);
80 
81 /* list of all NetToMedia entries */
82 struct mibarp_list mibarp_list = TAILQ_HEAD_INITIALIZER(mibarp_list);
83 
84 /* number of interfaces */
85 int32_t mib_if_number;
86 
87 /* last change of table */
88 uint64_t mib_iftable_last_change;
89 
90 /* last change of stack table */
91 uint64_t mib_ifstack_last_change;
92 
93 /* if this is set, one of our lists may be bad. refresh them when idle */
94 int mib_iflist_bad;
95 
96 /* network socket */
97 int mib_netsock;
98 
99 /* last time refreshed */
100 uint64_t mibarpticks;
101 
102 /* info on system clocks */
103 struct clockinfo clockinfo;
104 
105 /* list of all New if registrations */
106 static struct newifreg_list newifreg_list = TAILQ_HEAD_INITIALIZER(newifreg_list);
107 
108 /* baud rate of fastest interface */
109 uint64_t mibif_maxspeed;
110 
111 /* user-forced update interval */
112 u_int mibif_force_hc_update_interval;
113 
114 /* current update interval */
115 u_int mibif_hc_update_interval;
116 
117 /* HC update timer handle */
118 static void *hc_update_timer;
119 
120 /* Idle poll timer */
121 static void *mibII_poll_timer;
122 
123 /* interfaces' data poll interval */
124 u_int mibII_poll_ticks;
125 
126 /* Idle poll hook */
127 static void mibII_idle(void *arg __unused);
128 
129 /*****************************/
130 
131 static const struct asn_oid oid_ifMIB = OIDX_ifMIB;
132 static const struct asn_oid oid_ipMIB = OIDX_ipMIB;
133 static const struct asn_oid oid_tcpMIB = OIDX_tcpMIB;
134 static const struct asn_oid oid_udpMIB = OIDX_udpMIB;
135 static const struct asn_oid oid_ipForward = OIDX_ipForward;
136 static const struct asn_oid oid_linkDown = OIDX_linkDown;
137 static const struct asn_oid oid_linkUp = OIDX_linkUp;
138 static const struct asn_oid oid_ifIndex = OIDX_ifIndex;
139 
140 /*****************************/
141 
142 /*
143  * Find an interface
144  */
145 struct mibif *
146 mib_find_if(u_int idx)
147 {
148 	struct mibif *ifp;
149 
150 	TAILQ_FOREACH(ifp, &mibif_list, link)
151 		if (ifp->index == idx)
152 			return (ifp);
153 	return (NULL);
154 }
155 
156 struct mibif *
157 mib_find_if_sys(u_int sysindex)
158 {
159 	struct mibif *ifp;
160 
161 	TAILQ_FOREACH(ifp, &mibif_list, link)
162 		if (ifp->sysindex == sysindex)
163 			return (ifp);
164 	return (NULL);
165 }
166 
167 struct mibif *
168 mib_find_if_name(const char *name)
169 {
170 	struct mibif *ifp;
171 
172 	TAILQ_FOREACH(ifp, &mibif_list, link)
173 		if (strcmp(ifp->name, name) == 0)
174 			return (ifp);
175 	return (NULL);
176 }
177 
178 /*
179  * Check whether an interface is dynamic. The argument may include the
180  * unit number. This assumes, that the name part does NOT contain digits.
181  */
182 int
183 mib_if_is_dyn(const char *name)
184 {
185 	size_t len;
186 	struct mibdynif *d;
187 
188 	for (len = 0; name[len] != '\0' && isalpha(name[len]) ; len++)
189 		;
190 	SLIST_FOREACH(d, &mibdynif_list, link)
191 		if (strlen(d->name) == len && strncmp(d->name, name, len) == 0)
192 			return (1);
193 	return (0);
194 }
195 
196 /* set an interface name to dynamic mode */
197 void
198 mib_if_set_dyn(const char *name)
199 {
200 	struct mibdynif *d;
201 
202 	SLIST_FOREACH(d, &mibdynif_list, link)
203 		if (strcmp(name, d->name) == 0)
204 			return;
205 	if ((d = malloc(sizeof(*d))) == NULL)
206 		err(1, NULL);
207 	strlcpy(d->name, name, sizeof(d->name));
208 	SLIST_INSERT_HEAD(&mibdynif_list, d, link);
209 }
210 
211 /*
212  * register for interface creations
213  */
214 int
215 mib_register_newif(int (*func)(struct mibif *), const struct lmodule *mod)
216 {
217 	struct newifreg *reg;
218 
219 	TAILQ_FOREACH(reg, &newifreg_list, link)
220 		if (reg->mod == mod) {
221 			reg->func = func;
222 			return (0);
223 		}
224 	if ((reg = malloc(sizeof(*reg))) == NULL) {
225 		syslog(LOG_ERR, "newifreg: %m");
226 		return (-1);
227 	}
228 	reg->mod = mod;
229 	reg->func = func;
230 	TAILQ_INSERT_TAIL(&newifreg_list, reg, link);
231 
232 	return (0);
233 }
234 
235 void
236 mib_unregister_newif(const struct lmodule *mod)
237 {
238 	struct newifreg *reg;
239 
240 	TAILQ_FOREACH(reg, &newifreg_list, link)
241 		if (reg->mod == mod) {
242 			TAILQ_REMOVE(&newifreg_list, reg, link);
243 			free(reg);
244 			return;
245 		}
246 
247 }
248 
249 struct mibif *
250 mib_first_if(void)
251 {
252 	return (TAILQ_FIRST(&mibif_list));
253 }
254 struct mibif *
255 mib_next_if(const struct mibif *ifp)
256 {
257 	return (TAILQ_NEXT(ifp, link));
258 }
259 
260 /*
261  * Change the admin status of an interface
262  */
263 int
264 mib_if_admin(struct mibif *ifp, int up)
265 {
266 	struct ifreq ifr;
267 
268 	strlcpy(ifr.ifr_name, ifp->name, sizeof(ifr.ifr_name));
269 	if (ioctl(mib_netsock, SIOCGIFFLAGS, &ifr) == -1) {
270 		syslog(LOG_ERR, "SIOCGIFFLAGS(%s): %m", ifp->name);
271 		return (-1);
272 	}
273 	if (up)
274 		ifr.ifr_flags |= IFF_UP;
275 	else
276 		ifr.ifr_flags &= ~IFF_UP;
277 	if (ioctl(mib_netsock, SIOCSIFFLAGS, &ifr) == -1) {
278 		syslog(LOG_ERR, "SIOCSIFFLAGS(%s): %m", ifp->name);
279 		return (-1);
280 	}
281 
282 	(void)mib_fetch_ifmib(ifp);
283 
284 	return (0);
285 }
286 
287 /*
288  * Generate a link up/down trap
289  */
290 static void
291 link_trap(struct mibif *ifp, int up)
292 {
293 	struct snmp_value ifindex;
294 
295 	ifindex.var = oid_ifIndex;
296 	ifindex.var.subs[ifindex.var.len++] = ifp->index;
297 	ifindex.syntax = SNMP_SYNTAX_INTEGER;
298 	ifindex.v.integer = ifp->index;
299 
300 	snmp_send_trap(up ? &oid_linkUp : &oid_linkDown, &ifindex,
301 	    (struct snmp_value *)NULL);
302 }
303 
304 /**
305  * Fetch the GENERIC IFMIB and update the HC counters
306  */
307 static int
308 fetch_generic_mib(struct mibif *ifp, const struct ifmibdata *old)
309 {
310 	int name[6];
311 	size_t len;
312 	struct mibif_private *p = ifp->private;
313 
314 	name[0] = CTL_NET;
315 	name[1] = PF_LINK;
316 	name[2] = NETLINK_GENERIC;
317 	name[3] = IFMIB_IFDATA;
318 	name[4] = ifp->sysindex;
319 	name[5] = IFDATA_GENERAL;
320 
321 	len = sizeof(ifp->mib);
322 	if (sysctl(name, nitems(name), &ifp->mib, &len, NULL, 0) == -1) {
323 		if (errno != ENOENT)
324 			syslog(LOG_WARNING, "sysctl(ifmib, %s) failed %m",
325 			    ifp->name);
326 		return (-1);
327 	}
328 
329 	/*
330 	 * Assume that one of the two following compounds is optimized away
331 	 */
332 	if (ULONG_MAX >= 0xffffffffffffffffULL) {
333 		p->hc_inoctets = ifp->mib.ifmd_data.ifi_ibytes;
334 		p->hc_outoctets = ifp->mib.ifmd_data.ifi_obytes;
335 		p->hc_omcasts = ifp->mib.ifmd_data.ifi_omcasts;
336 		p->hc_opackets = ifp->mib.ifmd_data.ifi_opackets;
337 		p->hc_imcasts = ifp->mib.ifmd_data.ifi_imcasts;
338 		p->hc_ipackets = ifp->mib.ifmd_data.ifi_ipackets;
339 
340 	} else if (ULONG_MAX >= 0xffffffff) {
341 
342 #define	UPDATE(HC, MIB)							\
343 		if (old->ifmd_data.MIB > ifp->mib.ifmd_data.MIB)	\
344 			p->HC += (0x100000000ULL +			\
345 			    ifp->mib.ifmd_data.MIB) -			\
346 			    old->ifmd_data.MIB;				\
347 		else							\
348 			p->HC += ifp->mib.ifmd_data.MIB -		\
349 			    old->ifmd_data.MIB;
350 
351 		UPDATE(hc_inoctets, ifi_ibytes)
352 		UPDATE(hc_outoctets, ifi_obytes)
353 		UPDATE(hc_omcasts, ifi_omcasts)
354 		UPDATE(hc_opackets, ifi_opackets)
355 		UPDATE(hc_imcasts, ifi_imcasts)
356 		UPDATE(hc_ipackets, ifi_ipackets)
357 
358 #undef	UPDATE
359 	} else
360 		abort();
361 	return (0);
362 }
363 
364 /**
365  * Update the 64-bit interface counters
366  */
367 static void
368 update_hc_counters(void *arg __unused)
369 {
370 	struct mibif *ifp;
371 	struct ifmibdata oldmib;
372 
373 	TAILQ_FOREACH(ifp, &mibif_list, link) {
374 		oldmib = ifp->mib;
375 		(void)fetch_generic_mib(ifp, &oldmib);
376 	}
377 }
378 
379 /**
380  * Recompute the poll timer for the HC counters
381  */
382 void
383 mibif_reset_hc_timer(void)
384 {
385 	u_int ticks;
386 
387 	if ((ticks = mibif_force_hc_update_interval) == 0) {
388 		if (mibif_maxspeed <= IF_Mbps(10)) {
389 			/* at 10Mbps overflow needs 3436 seconds */
390 			ticks = 3000 * 100;	/* 50 minutes */
391 		} else if (mibif_maxspeed <= IF_Mbps(100)) {
392 			/* at 100Mbps overflow needs 343 seconds */
393 			ticks = 300 * 100;	/* 5 minutes */
394 		} else if (mibif_maxspeed < IF_Mbps(622)) {
395 			/* at 622Mbps overflow needs 53 seconds */
396 			ticks = 40 * 100;	/* 40 seconds */
397 		} else if (mibif_maxspeed <= IF_Mbps(1000)) {
398 			/* at 1Gbps overflow needs  34 seconds */
399 			ticks = 20 * 100;	/* 20 seconds */
400 		} else {
401 			/* at 10Gbps overflow needs 3.4 seconds */
402 			ticks = 100;		/* 1 seconds */
403 		}
404 	}
405 
406 	if (ticks == mibif_hc_update_interval)
407 		return;
408 
409 	if (hc_update_timer != NULL) {
410 		timer_stop(hc_update_timer);
411 		hc_update_timer = NULL;
412 	}
413 	update_hc_counters(NULL);
414 	if ((hc_update_timer = timer_start_repeat(ticks, ticks,
415 	    update_hc_counters, NULL, module)) == NULL) {
416 		syslog(LOG_ERR, "timer_start(%u): %m", ticks);
417 		return;
418 	}
419 	mibif_hc_update_interval = ticks;
420 }
421 
422 /**
423  * Restart the idle poll timer.
424  */
425 void
426 mibif_restart_mibII_poll_timer(void)
427 {
428 	if (mibII_poll_timer != NULL)
429 		timer_stop(mibII_poll_timer);
430 
431 	if ((mibII_poll_timer = timer_start_repeat(mibII_poll_ticks * 10,
432 	    mibII_poll_ticks * 10, mibII_idle, NULL, module)) == NULL)
433 		syslog(LOG_ERR, "timer_start(%u): %m", mibII_poll_ticks);
434 }
435 
436 /*
437  * Fetch new MIB data.
438  */
439 int
440 mib_fetch_ifmib(struct mibif *ifp)
441 {
442 	static int kmib[2] = { -1, 0 }; /* for sysctl net.ifdescr_maxlen */
443 
444 	int name[6];
445 	size_t kmiblen = nitems(kmib);
446 	size_t len;
447 	void *newmib;
448 	struct ifmibdata oldmib = ifp->mib;
449 	struct ifreq irr;
450 	unsigned int alias_maxlen = MIBIF_ALIAS_SIZE_MAX;
451 
452 	if (fetch_generic_mib(ifp, &oldmib) == -1)
453 		return (-1);
454 
455 	/*
456 	 * Quoting RFC2863, 3.1.15: "... LinkUp and linkDown traps are
457 	 * generated just after ifOperStatus leaves, or just before it
458 	 * enters, the down state, respectively;"
459 	 */
460 	if (ifp->trap_enable && ifp->mib.ifmd_data.ifi_link_state !=
461 	    oldmib.ifmd_data.ifi_link_state &&
462 	    (ifp->mib.ifmd_data.ifi_link_state == LINK_STATE_DOWN ||
463 	    oldmib.ifmd_data.ifi_link_state == LINK_STATE_DOWN))
464 		link_trap(ifp, ifp->mib.ifmd_data.ifi_link_state ==
465 		    LINK_STATE_UP ? 1 : 0);
466 
467 	ifp->flags &= ~(MIBIF_HIGHSPEED | MIBIF_VERYHIGHSPEED);
468 	if (ifp->mib.ifmd_data.ifi_baudrate > 20000000) {
469 		ifp->flags |= MIBIF_HIGHSPEED;
470 		if (ifp->mib.ifmd_data.ifi_baudrate > 650000000)
471 			ifp->flags |= MIBIF_VERYHIGHSPEED;
472 	}
473 	if (ifp->mib.ifmd_data.ifi_baudrate > mibif_maxspeed) {
474 		mibif_maxspeed = ifp->mib.ifmd_data.ifi_baudrate;
475 		mibif_reset_hc_timer();
476 	}
477 
478 	/*
479 	 * linkspecific MIB
480 	 */
481 	name[0] = CTL_NET;
482 	name[1] = PF_LINK;
483 	name[2] = NETLINK_GENERIC;
484 	name[3] = IFMIB_IFDATA;
485 	name[4] = ifp->sysindex;
486 	name[5] = IFDATA_LINKSPECIFIC;
487 	if (sysctl(name, nitems(name), NULL, &len, NULL, 0) == -1) {
488 		syslog(LOG_WARNING, "sysctl linkmib estimate (%s): %m",
489 		    ifp->name);
490 		if (ifp->specmib != NULL) {
491 			ifp->specmib = NULL;
492 			ifp->specmiblen = 0;
493 		}
494 		goto out;
495 	}
496 	if (len == 0) {
497 		if (ifp->specmib != NULL) {
498 			ifp->specmib = NULL;
499 			ifp->specmiblen = 0;
500 		}
501 		goto out;
502 	}
503 
504 	if (ifp->specmiblen != len) {
505 		if ((newmib = realloc(ifp->specmib, len)) == NULL) {
506 			ifp->specmib = NULL;
507 			ifp->specmiblen = 0;
508 			goto out;
509 		}
510 		ifp->specmib = newmib;
511 		ifp->specmiblen = len;
512 	}
513 	if (sysctl(name, nitems(name), ifp->specmib, &len, NULL, 0) == -1) {
514 		syslog(LOG_WARNING, "sysctl linkmib (%s): %m", ifp->name);
515 		if (ifp->specmib != NULL) {
516 			ifp->specmib = NULL;
517 			ifp->specmiblen = 0;
518 		}
519 	}
520 
521   out:
522 
523 	/*
524 	 * Find sysctl mib for net.ifdescr_maxlen (one time).
525 	 * kmib[0] == -1 at first call to mib_fetch_ifmib().
526 	 * Then kmib[0] > 0 if we found sysctl mib for net.ifdescr_maxlen.
527 	 * Else, kmib[0] == 0 (unexpected error from a kernel).
528 	 */
529 	if (kmib[0] < 0 &&
530 	    sysctlnametomib("net.ifdescr_maxlen", kmib, &kmiblen) < 0) {
531 		kmib[0] = 0;
532 		syslog(LOG_WARNING, "sysctlnametomib net.ifdescr_maxlen: %m");
533 	}
534 
535 	/*
536 	 * Fetch net.ifdescr_maxlen value every time to catch up with changes.
537 	 */
538 	len = sizeof(alias_maxlen);
539 	if (kmib[0] > 0 && sysctl(kmib, 2, &alias_maxlen, &len, NULL, 0) < 0) {
540 		/* unexpected error from the kernel, use default value */
541 		alias_maxlen = MIBIF_ALIAS_SIZE_MAX;
542 		syslog(LOG_WARNING, "sysctl net.ifdescr_maxlen: %m");
543 	}
544 
545 	/*
546 	 * Kernel limit might be decreased after interfaces got
547 	 * their descriptions assigned. Try to obtain them anyway.
548 	 */
549 	if (alias_maxlen == 0)
550 		alias_maxlen = MIBIF_ALIAS_SIZE_MAX;
551 
552 	/*
553 	 * Allocate maximum memory for a buffer and later reallocate
554 	 * to free extra memory.
555 	 */
556 	if ((ifp->alias = malloc(alias_maxlen)) == NULL) {
557 		syslog(LOG_WARNING, "malloc(%d) failed: %m", (int)alias_maxlen);
558 		goto fin;
559 	}
560 
561 	strlcpy(irr.ifr_name, ifp->name, sizeof(irr.ifr_name));
562 	irr.ifr_buffer.buffer = ifp->alias;
563 	irr.ifr_buffer.length = alias_maxlen;
564 	if (ioctl(mib_netsock, SIOCGIFDESCR, &irr) == -1) {
565 		free(ifp->alias);
566 		ifp->alias = NULL;
567 		if (errno != ENOMSG)
568 			syslog(LOG_WARNING, "SIOCGIFDESCR (%s): %m", ifp->name);
569 	} else if (irr.ifr_buffer.buffer == NULL) {
570 		free(ifp->alias);
571 		ifp->alias = NULL;
572 		syslog(LOG_WARNING, "SIOCGIFDESCR (%s): too long (%zu)",
573 		    ifp->name, irr.ifr_buffer.length);
574 	} else {
575 		ifp->alias_size = strnlen(ifp->alias, alias_maxlen) + 1;
576 
577 		if (ifp->alias_size > MIBIF_ALIAS_SIZE)
578 		    ifp->alias_size = MIBIF_ALIAS_SIZE;
579 
580 		if (ifp->alias_size < alias_maxlen)
581 			ifp->alias = realloc(ifp->alias, ifp->alias_size);
582 	}
583 
584 fin:
585 	ifp->mibtick = get_ticks();
586 	return (0);
587 }
588 
589 /* find first/next address for a given interface */
590 struct mibifa *
591 mib_first_ififa(const struct mibif *ifp)
592 {
593 	struct mibifa *ifa;
594 
595 	TAILQ_FOREACH(ifa, &mibifa_list, link)
596 		if (ifp->index == ifa->ifindex)
597 			return (ifa);
598 	return (NULL);
599 }
600 
601 struct mibifa *
602 mib_next_ififa(struct mibifa *ifa0)
603 {
604 	struct mibifa *ifa;
605 
606 	ifa = ifa0;
607 	while ((ifa = TAILQ_NEXT(ifa, link)) != NULL)
608 		if (ifa->ifindex == ifa0->ifindex)
609 			return (ifa);
610 	return (NULL);
611 }
612 
613 /*
614  * Allocate a new IFA
615  */
616 static struct mibifa *
617 alloc_ifa(u_int ifindex, struct in_addr addr)
618 {
619 	struct mibifa *ifa;
620 	uint32_t ha;
621 
622 	if ((ifa = malloc(sizeof(struct mibifa))) == NULL) {
623 		syslog(LOG_ERR, "ifa: %m");
624 		return (NULL);
625 	}
626 	ifa->inaddr = addr;
627 	ifa->ifindex = ifindex;
628 
629 	ha = ntohl(ifa->inaddr.s_addr);
630 	ifa->index.len = 4;
631 	ifa->index.subs[0] = (ha >> 24) & 0xff;
632 	ifa->index.subs[1] = (ha >> 16) & 0xff;
633 	ifa->index.subs[2] = (ha >>  8) & 0xff;
634 	ifa->index.subs[3] = (ha >>  0) & 0xff;
635 
636 	ifa->flags = 0;
637 	ifa->inbcast.s_addr = 0;
638 	ifa->inmask.s_addr = 0xffffffff;
639 
640 	INSERT_OBJECT_OID(ifa, &mibifa_list);
641 
642 	return (ifa);
643 }
644 
645 /*
646  * Delete an interface address
647  */
648 static void
649 destroy_ifa(struct mibifa *ifa)
650 {
651 	TAILQ_REMOVE(&mibifa_list, ifa, link);
652 	free(ifa);
653 }
654 
655 
656 /*
657  * Helper routine to extract the sockaddr structures from a routing
658  * socket message.
659  */
660 void
661 mib_extract_addrs(int addrs, u_char *info, struct sockaddr **out)
662 {
663 	u_int i;
664 
665 	for (i = 0; i < RTAX_MAX; i++) {
666 		if ((addrs & (1 << i)) != 0) {
667 			*out = (struct sockaddr *)(void *)info;
668 			info += roundup((*out)->sa_len, sizeof(long));
669 		} else
670 			*out = NULL;
671 		out++;
672 	}
673 }
674 
675 /*
676  * save the phys address of an interface. Handle receive address entries here.
677  */
678 static void
679 get_physaddr(struct mibif *ifp, struct sockaddr_dl *sdl, u_char *ptr)
680 {
681 	u_char *np;
682 	struct mibrcvaddr *rcv;
683 
684 	if (sdl->sdl_alen == 0) {
685 		/* no address */
686 		if (ifp->physaddrlen != 0) {
687 			if ((rcv = mib_find_rcvaddr(ifp->index, ifp->physaddr,
688 			    ifp->physaddrlen)) != NULL)
689 				mib_rcvaddr_delete(rcv);
690 			free(ifp->physaddr);
691 			ifp->physaddr = NULL;
692 			ifp->physaddrlen = 0;
693 		}
694 		return;
695 	}
696 
697 	if (ifp->physaddrlen != sdl->sdl_alen) {
698 		/* length changed */
699 		if (ifp->physaddrlen) {
700 			/* delete olf receive address */
701 			if ((rcv = mib_find_rcvaddr(ifp->index, ifp->physaddr,
702 			    ifp->physaddrlen)) != NULL)
703 				mib_rcvaddr_delete(rcv);
704 		}
705 		if ((np = realloc(ifp->physaddr, sdl->sdl_alen)) == NULL) {
706 			free(ifp->physaddr);
707 			ifp->physaddr = NULL;
708 			ifp->physaddrlen = 0;
709 			return;
710 		}
711 		ifp->physaddr = np;
712 		ifp->physaddrlen = sdl->sdl_alen;
713 
714 	} else if (memcmp(ifp->physaddr, ptr, ifp->physaddrlen) == 0) {
715 		/* no change */
716 		return;
717 
718 	} else {
719 		/* address changed */
720 
721 		/* delete olf receive address */
722 		if ((rcv = mib_find_rcvaddr(ifp->index, ifp->physaddr,
723 		    ifp->physaddrlen)) != NULL)
724 			mib_rcvaddr_delete(rcv);
725 	}
726 
727 	memcpy(ifp->physaddr, ptr, ifp->physaddrlen);
728 
729 	/* make new receive address */
730 	if ((rcv = mib_rcvaddr_create(ifp, ifp->physaddr, ifp->physaddrlen)) != NULL)
731 		rcv->flags |= MIBRCVADDR_HW;
732 }
733 
734 /*
735  * Free an interface
736  */
737 static void
738 mibif_free(struct mibif *ifp)
739 {
740 	struct mibif *ifp1;
741 	struct mibindexmap *map;
742 	struct mibifa *ifa, *ifa1;
743 	struct mibrcvaddr *rcv, *rcv1;
744 	struct mibarp *at, *at1;
745 
746 	if (ifp->xnotify != NULL)
747 		(*ifp->xnotify)(ifp, MIBIF_NOTIFY_DESTROY, ifp->xnotify_data);
748 
749 	(void)mib_ifstack_delete(ifp, NULL);
750 	(void)mib_ifstack_delete(NULL, ifp);
751 
752 	TAILQ_REMOVE(&mibif_list, ifp, link);
753 
754 	/* if this was the fastest interface - recompute this */
755 	if (ifp->mib.ifmd_data.ifi_baudrate == mibif_maxspeed) {
756 		mibif_maxspeed = ifp->mib.ifmd_data.ifi_baudrate;
757 		TAILQ_FOREACH(ifp1, &mibif_list, link)
758 			if (ifp1->mib.ifmd_data.ifi_baudrate > mibif_maxspeed)
759 				mibif_maxspeed =
760 				    ifp1->mib.ifmd_data.ifi_baudrate;
761 		mibif_reset_hc_timer();
762 	}
763 
764 	if (ifp->alias != NULL) {
765 		free(ifp->alias);
766 		ifp->alias = NULL;
767 	}
768 	free(ifp->private);
769 	ifp->private = NULL;
770 	free(ifp->physaddr);
771 	ifp->physaddr = NULL;
772 	free(ifp->specmib);
773 	ifp->specmib = NULL;
774 
775 	STAILQ_FOREACH(map, &mibindexmap_list, link)
776 		if (map->mibif == ifp) {
777 			map->mibif = NULL;
778 			break;
779 		}
780 
781 	/* purge interface addresses */
782 	ifa = TAILQ_FIRST(&mibifa_list);
783 	while (ifa != NULL) {
784 		ifa1 = TAILQ_NEXT(ifa, link);
785 		if (ifa->ifindex == ifp->index)
786 			destroy_ifa(ifa);
787 		ifa = ifa1;
788 	}
789 
790 	/* purge receive addresses */
791 	rcv = TAILQ_FIRST(&mibrcvaddr_list);
792 	while (rcv != NULL) {
793 		rcv1 = TAILQ_NEXT(rcv, link);
794 		if (rcv->ifindex == ifp->index)
795 			mib_rcvaddr_delete(rcv);
796 		rcv = rcv1;
797 	}
798 
799 	/* purge ARP entries */
800 	at = TAILQ_FIRST(&mibarp_list);
801 	while (at != NULL) {
802 		at1 = TAILQ_NEXT(at, link);
803 		if (at->index.subs[0] == ifp->index)
804 			mib_arp_delete(at);
805 		at = at1;
806 	}
807 
808 	free(ifp);
809 	ifp = NULL;
810 	mib_if_number--;
811 	mib_iftable_last_change = this_tick;
812 }
813 
814 /*
815  * Create a new interface
816  */
817 static struct mibif *
818 mibif_create(u_int sysindex, const char *name)
819 {
820 	struct mibif *ifp;
821 	struct mibindexmap *map;
822 
823 	if ((ifp = malloc(sizeof(*ifp))) == NULL) {
824 		syslog(LOG_WARNING, "%s: %m", __func__);
825 		return (NULL);
826 	}
827 	memset(ifp, 0, sizeof(*ifp));
828 	if ((ifp->private = malloc(sizeof(struct mibif_private))) == NULL) {
829 		syslog(LOG_WARNING, "%s: %m", __func__);
830 		free(ifp);
831 		return (NULL);
832 	}
833 	memset(ifp->private, 0, sizeof(struct mibif_private));
834 
835 	ifp->sysindex = sysindex;
836 	strlcpy(ifp->name, name, sizeof(ifp->name));
837 	strlcpy(ifp->descr, name, sizeof(ifp->descr));
838 	ifp->spec_oid = oid_zeroDotZero;
839 
840 	map = NULL;
841 	if (!mib_if_is_dyn(ifp->name)) {
842 		/* non-dynamic. look whether we know the interface */
843 		STAILQ_FOREACH(map, &mibindexmap_list, link)
844 			if (strcmp(map->name, ifp->name) == 0) {
845 				ifp->index = map->ifindex;
846 				map->mibif = ifp;
847 				break;
848 			}
849 		/* assume it has a connector if it is not dynamic */
850 		ifp->has_connector = 1;
851 		ifp->trap_enable = 1;
852 	}
853 	if (map == NULL) {
854 		/* new interface - get new index */
855 		if (next_if_index > 0x7fffffff)
856 			errx(1, "ifindex wrap");
857 
858 		if ((map = malloc(sizeof(*map))) == NULL) {
859 			syslog(LOG_ERR, "ifmap: %m");
860 			free(ifp);
861 			return (NULL);
862 		}
863 		map->ifindex = next_if_index++;
864 		map->sysindex = ifp->sysindex;
865 		strcpy(map->name, ifp->name);
866 		map->mibif = ifp;
867 		STAILQ_INSERT_TAIL(&mibindexmap_list, map, link);
868 	} else {
869 		/* re-instantiate. Introduce a counter discontinuity */
870 		ifp->counter_disc = get_ticks();
871 	}
872 	ifp->index = map->ifindex;
873 	ifp->mib.ifmd_data.ifi_link_state = LINK_STATE_UNKNOWN;
874 
875 	INSERT_OBJECT_INT(ifp, &mibif_list);
876 	mib_if_number++;
877 	mib_iftable_last_change = this_tick;
878 
879 	/* instantiate default ifStack entries */
880 	(void)mib_ifstack_create(ifp, NULL);
881 	(void)mib_ifstack_create(NULL, ifp);
882 
883 	return (ifp);
884 }
885 
886 /*
887  * Inform all interested parties about a new interface
888  */
889 static void
890 notify_newif(struct mibif *ifp)
891 {
892 	struct newifreg *reg;
893 
894 	TAILQ_FOREACH(reg, &newifreg_list, link)
895 		if ((*reg->func)(ifp))
896 			return;
897 }
898 
899 /*
900  * This is called for new interfaces after we have fetched the interface
901  * MIB. If this is a broadcast interface try to guess the broadcast address
902  * depending on the interface type.
903  */
904 static void
905 check_llbcast(struct mibif *ifp)
906 {
907 	static u_char ether_bcast[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
908 	struct mibrcvaddr *rcv;
909 
910 	if (!(ifp->mib.ifmd_flags & IFF_BROADCAST))
911 		return;
912 
913 	switch (ifp->mib.ifmd_data.ifi_type) {
914 
915 	  case IFT_ETHER:
916 	  case IFT_FDDI:
917 	  case IFT_ISO88025:
918 	  case IFT_L2VLAN:
919 		if (mib_find_rcvaddr(ifp->index, ether_bcast, 6) == NULL &&
920 		    (rcv = mib_rcvaddr_create(ifp, ether_bcast, 6)) != NULL)
921 			rcv->flags |= MIBRCVADDR_BCAST;
922 		break;
923 	}
924 }
925 
926 
927 /*
928  * Retrieve the current interface list from the system.
929  */
930 void
931 mib_refresh_iflist(void)
932 {
933 	struct mibif *ifp, *ifp1;
934 	size_t len;
935 	u_short idx;
936 	int name[6];
937 	int count;
938 	struct ifmibdata mib;
939 
940 	TAILQ_FOREACH(ifp, &mibif_list, link)
941 		ifp->flags &= ~MIBIF_FOUND;
942 
943 	len = sizeof(count);
944 	if (sysctlbyname("net.link.generic.system.ifcount", &count, &len,
945 	    NULL, 0) == -1) {
946 		syslog(LOG_ERR, "ifcount: %m");
947 		return;
948 	}
949 	name[0] = CTL_NET;
950 	name[1] = PF_LINK;
951 	name[2] = NETLINK_GENERIC;
952 	name[3] = IFMIB_IFDATA;
953 	name[5] = IFDATA_GENERAL;
954 	for (idx = 1; idx <= count; idx++) {
955 		name[4] = idx;
956 		len = sizeof(mib);
957 		if (sysctl(name, nitems(name), &mib, &len, NULL, 0) == -1) {
958 			if (errno == ENOENT)
959 				continue;
960 			syslog(LOG_ERR, "ifmib(%u): %m", idx);
961 			return;
962 		}
963 		if ((ifp = mib_find_if_sys(idx)) != NULL) {
964 			ifp->flags |= MIBIF_FOUND;
965 			continue;
966 		}
967 		/* Unknown interface - create */
968 		if ((ifp = mibif_create(idx, mib.ifmd_name)) != NULL) {
969 			ifp->flags |= MIBIF_FOUND;
970 			(void)mib_fetch_ifmib(ifp);
971 			check_llbcast(ifp);
972 			notify_newif(ifp);
973 		}
974 	}
975 
976 	/*
977 	 * Purge interfaces that disappeared
978 	 */
979 	ifp = TAILQ_FIRST(&mibif_list);
980 	while (ifp != NULL) {
981 		ifp1 = TAILQ_NEXT(ifp, link);
982 		if (!(ifp->flags & MIBIF_FOUND))
983 			mibif_free(ifp);
984 		ifp = ifp1;
985 	}
986 }
987 
988 /*
989  * Find an interface address
990  */
991 struct mibifa *
992 mib_find_ifa(struct in_addr addr)
993 {
994 	struct mibifa *ifa;
995 
996 	TAILQ_FOREACH(ifa, &mibifa_list, link)
997 		if (ifa->inaddr.s_addr == addr.s_addr)
998 			return (ifa);
999 	return (NULL);
1000 }
1001 
1002 /*
1003  * Process a new ARP entry
1004  */
1005 static void
1006 process_arp(const struct rt_msghdr *rtm, const struct sockaddr_dl *sdl,
1007     const struct sockaddr_in *sa)
1008 {
1009 	struct mibif *ifp;
1010 	struct mibarp *at;
1011 
1012 	/* IP arp table entry */
1013 	if (sdl->sdl_alen == 0)
1014 		return;
1015 	if ((ifp = mib_find_if_sys(sdl->sdl_index)) == NULL)
1016 		return;
1017 	/* have a valid entry */
1018 	if ((at = mib_find_arp(ifp, sa->sin_addr)) == NULL &&
1019 	    (at = mib_arp_create(ifp, sa->sin_addr,
1020 	    sdl->sdl_data + sdl->sdl_nlen, sdl->sdl_alen)) == NULL)
1021 		return;
1022 
1023 	if (rtm->rtm_rmx.rmx_expire == 0)
1024 		at->flags |= MIBARP_PERM;
1025 	else
1026 		at->flags &= ~MIBARP_PERM;
1027 	at->flags |= MIBARP_FOUND;
1028 }
1029 
1030 /*
1031  * Handle a routing socket message.
1032  */
1033 static void
1034 handle_rtmsg(struct rt_msghdr *rtm)
1035 {
1036 	struct sockaddr *addrs[RTAX_MAX];
1037 	struct if_msghdr *ifm;
1038 	struct ifa_msghdr ifam, *ifamp;
1039 	struct ifma_msghdr *ifmam;
1040 #ifdef RTM_IFANNOUNCE
1041 	struct if_announcemsghdr *ifan;
1042 #endif
1043 	struct mibif *ifp;
1044 	struct sockaddr_dl *sdl;
1045 	struct sockaddr_in *sa;
1046 	struct mibifa *ifa;
1047 	struct mibrcvaddr *rcv;
1048 	u_char *ptr;
1049 
1050 	if (rtm->rtm_version != RTM_VERSION) {
1051 		syslog(LOG_ERR, "Bogus RTM version %u", rtm->rtm_version);
1052 		return;
1053 	}
1054 
1055 	switch (rtm->rtm_type) {
1056 
1057 	  case RTM_NEWADDR:
1058 		ifamp = (struct ifa_msghdr *)rtm;
1059 		memcpy(&ifam, ifamp, sizeof(ifam));
1060 		mib_extract_addrs(ifam.ifam_addrs, (u_char *)(ifamp + 1), addrs);
1061 		if (addrs[RTAX_IFA] == NULL || addrs[RTAX_NETMASK] == NULL)
1062 			break;
1063 
1064 		sa = (struct sockaddr_in *)(void *)addrs[RTAX_IFA];
1065 		if ((ifa = mib_find_ifa(sa->sin_addr)) == NULL) {
1066 			/* unknown address */
1067 		    	if ((ifp = mib_find_if_sys(ifam.ifam_index)) == NULL) {
1068 				syslog(LOG_WARNING, "RTM_NEWADDR for unknown "
1069 				    "interface %u", ifam.ifam_index);
1070 				break;
1071 			}
1072 		     	if ((ifa = alloc_ifa(ifp->index, sa->sin_addr)) == NULL)
1073 				break;
1074 		}
1075 		sa = (struct sockaddr_in *)(void *)addrs[RTAX_NETMASK];
1076 		ifa->inmask = sa->sin_addr;
1077 
1078 		if (addrs[RTAX_BRD] != NULL) {
1079 			sa = (struct sockaddr_in *)(void *)addrs[RTAX_BRD];
1080 			ifa->inbcast = sa->sin_addr;
1081 		}
1082 		ifa->flags |= MIBIFA_FOUND;
1083 		break;
1084 
1085 	  case RTM_DELADDR:
1086 		ifamp = (struct ifa_msghdr *)rtm;
1087 		memcpy(&ifam, ifamp, sizeof(ifam));
1088 		mib_extract_addrs(ifam.ifam_addrs, (u_char *)(ifamp + 1), addrs);
1089 		if (addrs[RTAX_IFA] == NULL)
1090 			break;
1091 
1092 		sa = (struct sockaddr_in *)(void *)addrs[RTAX_IFA];
1093 		if ((ifa = mib_find_ifa(sa->sin_addr)) != NULL) {
1094 			ifa->flags |= MIBIFA_FOUND;
1095 			if (!(ifa->flags & MIBIFA_DESTROYED))
1096 				destroy_ifa(ifa);
1097 		}
1098 		break;
1099 
1100 	  case RTM_NEWMADDR:
1101 		ifmam = (struct ifma_msghdr *)rtm;
1102 		mib_extract_addrs(ifmam->ifmam_addrs, (u_char *)(ifmam + 1), addrs);
1103 		if (addrs[RTAX_IFA] == NULL ||
1104 		    addrs[RTAX_IFA]->sa_family != AF_LINK)
1105 			break;
1106 		sdl = (struct sockaddr_dl *)(void *)addrs[RTAX_IFA];
1107 		if ((rcv = mib_find_rcvaddr(sdl->sdl_index,
1108 		    sdl->sdl_data + sdl->sdl_nlen, sdl->sdl_alen)) == NULL) {
1109 			/* unknown address */
1110 		    	if ((ifp = mib_find_if_sys(sdl->sdl_index)) == NULL) {
1111 				syslog(LOG_WARNING, "RTM_NEWMADDR for unknown "
1112 				    "interface %u", sdl->sdl_index);
1113 				break;
1114 			}
1115 		     	if ((rcv = mib_rcvaddr_create(ifp,
1116 			    sdl->sdl_data + sdl->sdl_nlen, sdl->sdl_alen)) == NULL)
1117 				break;
1118 			rcv->flags |= MIBRCVADDR_VOLATILE;
1119 		}
1120 		rcv->flags |= MIBRCVADDR_FOUND;
1121 		break;
1122 
1123 	  case RTM_DELMADDR:
1124 		ifmam = (struct ifma_msghdr *)rtm;
1125 		mib_extract_addrs(ifmam->ifmam_addrs, (u_char *)(ifmam + 1), addrs);
1126 		if (addrs[RTAX_IFA] == NULL ||
1127 		    addrs[RTAX_IFA]->sa_family != AF_LINK)
1128 			break;
1129 		sdl = (struct sockaddr_dl *)(void *)addrs[RTAX_IFA];
1130 		if ((rcv = mib_find_rcvaddr(sdl->sdl_index,
1131 		    sdl->sdl_data + sdl->sdl_nlen, sdl->sdl_alen)) != NULL)
1132 			mib_rcvaddr_delete(rcv);
1133 		break;
1134 
1135 	  case RTM_IFINFO:
1136 		ifm = (struct if_msghdr *)(void *)rtm;
1137 		mib_extract_addrs(ifm->ifm_addrs, (u_char *)(ifm + 1), addrs);
1138 		if ((ifp = mib_find_if_sys(ifm->ifm_index)) == NULL)
1139 			break;
1140 		if (addrs[RTAX_IFP] != NULL &&
1141 		    addrs[RTAX_IFP]->sa_family == AF_LINK) {
1142 			sdl = (struct sockaddr_dl *)(void *)addrs[RTAX_IFP];
1143 			ptr = sdl->sdl_data + sdl->sdl_nlen;
1144 			get_physaddr(ifp, sdl, ptr);
1145 		}
1146 		(void)mib_fetch_ifmib(ifp);
1147 		break;
1148 
1149 #ifdef RTM_IFANNOUNCE
1150 	  case RTM_IFANNOUNCE:
1151 		ifan = (struct if_announcemsghdr *)rtm;
1152 		ifp = mib_find_if_sys(ifan->ifan_index);
1153 
1154 		switch (ifan->ifan_what) {
1155 
1156 		  case IFAN_ARRIVAL:
1157 			if (ifp == NULL && (ifp = mibif_create(ifan->ifan_index,
1158 			    ifan->ifan_name)) != NULL) {
1159 				(void)mib_fetch_ifmib(ifp);
1160 				check_llbcast(ifp);
1161 				notify_newif(ifp);
1162 			}
1163 			break;
1164 
1165 		  case IFAN_DEPARTURE:
1166 			if (ifp != NULL)
1167 				mibif_free(ifp);
1168 			break;
1169 		}
1170 		break;
1171 #endif
1172 	  case RTM_GET:
1173 	  case RTM_ADD:
1174 		mib_extract_addrs(rtm->rtm_addrs, (u_char *)(rtm + 1), addrs);
1175 		if (rtm->rtm_flags & RTF_LLINFO) {
1176 			if (addrs[RTAX_DST] == NULL ||
1177 			    addrs[RTAX_GATEWAY] == NULL ||
1178 			    addrs[RTAX_DST]->sa_family != AF_INET ||
1179 			    addrs[RTAX_GATEWAY]->sa_family != AF_LINK)
1180 				break;
1181 			process_arp(rtm,
1182 			    (struct sockaddr_dl *)(void *)addrs[RTAX_GATEWAY],
1183 			    (struct sockaddr_in *)(void *)addrs[RTAX_DST]);
1184 		} else {
1185 			if (rtm->rtm_errno == 0 && (rtm->rtm_flags & RTF_UP))
1186 				mib_sroute_process(rtm, addrs[RTAX_GATEWAY],
1187 				    addrs[RTAX_DST], addrs[RTAX_NETMASK]);
1188 		}
1189 		break;
1190 
1191 	  case RTM_DELETE:
1192 		mib_extract_addrs(rtm->rtm_addrs, (u_char *)(rtm + 1), addrs);
1193 
1194 		if (rtm->rtm_errno == 0 && (rtm->rtm_flags & RTF_UP))
1195 			mib_sroute_process(rtm, addrs[RTAX_GATEWAY],
1196 			    addrs[RTAX_DST], addrs[RTAX_NETMASK]);
1197 		break;
1198 	}
1199 }
1200 
1201 /*
1202  * send a routing message
1203  */
1204 void
1205 mib_send_rtmsg(struct rt_msghdr *rtm, struct sockaddr *gw,
1206     struct sockaddr *dst, struct sockaddr *mask)
1207 {
1208 	size_t len;
1209 	struct rt_msghdr *msg;
1210 	char *cp;
1211 	ssize_t sent;
1212 
1213 	len = sizeof(*rtm) + SA_SIZE(gw) + SA_SIZE(dst) + SA_SIZE(mask);
1214 	if ((msg = malloc(len)) == NULL) {
1215 		syslog(LOG_ERR, "%s: %m", __func__);
1216 		return;
1217 	}
1218 	cp = (char *)(msg + 1);
1219 
1220 	memset(msg, 0, sizeof(*msg));
1221 	msg->rtm_flags = 0;
1222 	msg->rtm_version = RTM_VERSION;
1223 	msg->rtm_addrs = RTA_DST | RTA_GATEWAY;
1224 
1225 	memcpy(cp, dst, SA_SIZE(dst));
1226 	cp += SA_SIZE(dst);
1227 	memcpy(cp, gw, SA_SIZE(gw));
1228 	cp += SA_SIZE(gw);
1229 	if (mask != NULL) {
1230 		memcpy(cp, mask, SA_SIZE(mask));
1231 		cp += SA_SIZE(mask);
1232 		msg->rtm_addrs |= RTA_NETMASK;
1233 	}
1234 	msg->rtm_msglen = cp - (char *)msg;
1235 	msg->rtm_type = RTM_GET;
1236 	if ((sent = write(route, msg, msg->rtm_msglen)) == -1) {
1237 		syslog(LOG_ERR, "%s: write: %m", __func__);
1238 		free(msg);
1239 		return;
1240 	}
1241 	if (sent != msg->rtm_msglen) {
1242 		syslog(LOG_ERR, "%s: short write", __func__);
1243 		free(msg);
1244 		return;
1245 	}
1246 	free(msg);
1247 }
1248 
1249 /*
1250  * Fetch the routing table via sysctl
1251  */
1252 u_char *
1253 mib_fetch_rtab(int af, int info, int arg, size_t *lenp)
1254 {
1255 	int name[6];
1256 	u_char *buf, *newbuf;
1257 
1258 	name[0] = CTL_NET;
1259 	name[1] = PF_ROUTE;
1260 	name[2] = 0;
1261 	name[3] = af;
1262 	name[4] = info;
1263 	name[5] = arg;
1264 
1265 	*lenp = 0;
1266 
1267 	/* initial estimate */
1268 	if (sysctl(name, nitems(name), NULL, lenp, NULL, 0) == -1) {
1269 		syslog(LOG_ERR, "sysctl estimate (%d,%d,%d,%d,%d,%d): %m",
1270 		    name[0], name[1], name[2], name[3], name[4], name[5]);
1271 		return (NULL);
1272 	}
1273 	if (*lenp == 0)
1274 		return (NULL);
1275 
1276 	buf = NULL;
1277 	for (;;) {
1278 		if ((newbuf = realloc(buf, *lenp)) == NULL) {
1279 			syslog(LOG_ERR, "sysctl buffer: %m");
1280 			free(buf);
1281 			return (NULL);
1282 		}
1283 		buf = newbuf;
1284 
1285 		if (sysctl(name, nitems(name), buf, lenp, NULL, 0) == 0)
1286 			break;
1287 
1288 		if (errno != ENOMEM) {
1289 			syslog(LOG_ERR, "sysctl get: %m");
1290 			free(buf);
1291 			return (NULL);
1292 		}
1293 		*lenp += *lenp / 8 + 1;
1294 	}
1295 
1296 	return (buf);
1297 }
1298 
1299 /*
1300  * Update the following info: interface, interface addresses, interface
1301  * receive addresses, arp-table.
1302  * This does not change the interface list itself.
1303  */
1304 static void
1305 update_ifa_info(void)
1306 {
1307 	u_char *buf, *next;
1308 	struct rt_msghdr *rtm;
1309 	struct mibifa *ifa, *ifa1;
1310 	struct mibrcvaddr *rcv, *rcv1;
1311 	size_t needed;
1312 	static const int infos[][3] = {
1313 		{ 0, NET_RT_IFLIST, 0 },
1314 #ifdef NET_RT_IFMALIST
1315 		{ AF_LINK, NET_RT_IFMALIST, 0 },
1316 #endif
1317 	};
1318 	u_int i;
1319 
1320 	TAILQ_FOREACH(ifa, &mibifa_list, link)
1321 		ifa->flags &= ~MIBIFA_FOUND;
1322 	TAILQ_FOREACH(rcv, &mibrcvaddr_list, link)
1323 		rcv->flags &= ~MIBRCVADDR_FOUND;
1324 
1325 	for (i = 0; i < sizeof(infos) / sizeof(infos[0]); i++) {
1326 		if ((buf = mib_fetch_rtab(infos[i][0], infos[i][1], infos[i][2],
1327 		   &needed)) == NULL)
1328 			continue;
1329 
1330 		next = buf;
1331 		while (next < buf + needed) {
1332 			rtm = (struct rt_msghdr *)(void *)next;
1333 			next += rtm->rtm_msglen;
1334 			handle_rtmsg(rtm);
1335 		}
1336 		free(buf);
1337 	}
1338 
1339 	/*
1340 	 * Purge the address list of unused entries. These may happen for
1341 	 * interface aliases that are on the same subnet. We don't receive
1342 	 * routing socket messages for them.
1343 	 */
1344 	ifa = TAILQ_FIRST(&mibifa_list);
1345 	while (ifa != NULL) {
1346 		ifa1 = TAILQ_NEXT(ifa, link);
1347 		if (!(ifa->flags & MIBIFA_FOUND))
1348 			destroy_ifa(ifa);
1349 		ifa = ifa1;
1350 	}
1351 
1352 	rcv = TAILQ_FIRST(&mibrcvaddr_list);
1353 	while (rcv != NULL) {
1354 		rcv1 = TAILQ_NEXT(rcv, link);
1355 		if (!(rcv->flags & (MIBRCVADDR_FOUND | MIBRCVADDR_BCAST |
1356 		    MIBRCVADDR_HW)))
1357 			mib_rcvaddr_delete(rcv);
1358 		rcv = rcv1;
1359 	}
1360 }
1361 
1362 /*
1363  * Update arp table
1364  */
1365 void
1366 mib_arp_update(void)
1367 {
1368 	struct mibarp *at, *at1;
1369 	size_t needed;
1370 	u_char *buf, *next;
1371 	struct rt_msghdr *rtm;
1372 
1373 	if (in_update_arp)
1374 		return;		/* Aaargh */
1375 	in_update_arp = 1;
1376 
1377 	TAILQ_FOREACH(at, &mibarp_list, link)
1378 		at->flags &= ~MIBARP_FOUND;
1379 
1380 	if ((buf = mib_fetch_rtab(AF_INET, NET_RT_FLAGS, 0, &needed)) == NULL) {
1381 		in_update_arp = 0;
1382 		return;
1383 	}
1384 
1385 	next = buf;
1386 	while (next < buf + needed) {
1387 		rtm = (struct rt_msghdr *)(void *)next;
1388 		next += rtm->rtm_msglen;
1389 		handle_rtmsg(rtm);
1390 	}
1391 	free(buf);
1392 
1393 	at = TAILQ_FIRST(&mibarp_list);
1394 	while (at != NULL) {
1395 		at1 = TAILQ_NEXT(at, link);
1396 		if (!(at->flags & MIBARP_FOUND))
1397 			mib_arp_delete(at);
1398 		at = at1;
1399 	}
1400 	mibarpticks = get_ticks();
1401 	in_update_arp = 0;
1402 }
1403 
1404 
1405 /*
1406  * Input on the routing socket.
1407  */
1408 static void
1409 route_input(int fd, void *udata __unused)
1410 {
1411 	u_char	buf[1024 * 16];
1412 	ssize_t n;
1413 	struct rt_msghdr *rtm;
1414 
1415 	if ((n = read(fd, buf, sizeof(buf))) == -1)
1416 		err(1, "read(rt_socket)");
1417 
1418 	if (n == 0)
1419 		errx(1, "EOF on rt_socket");
1420 
1421 	rtm = (struct rt_msghdr *)(void *)buf;
1422 	if ((size_t)n != rtm->rtm_msglen)
1423 		errx(1, "n=%zu, rtm_msglen=%u", (size_t)n, rtm->rtm_msglen);
1424 
1425 	handle_rtmsg(rtm);
1426 }
1427 
1428 /*
1429  * execute and SIOCAIFADDR
1430  */
1431 static int
1432 siocaifaddr(char *ifname, struct in_addr addr, struct in_addr mask,
1433     struct in_addr bcast)
1434 {
1435 	struct ifaliasreq addreq;
1436 	struct sockaddr_in *sa;
1437 
1438 	memset(&addreq, 0, sizeof(addreq));
1439 	strlcpy(addreq.ifra_name, ifname, sizeof(addreq.ifra_name));
1440 
1441 	sa = (struct sockaddr_in *)(void *)&addreq.ifra_addr;
1442 	sa->sin_family = AF_INET;
1443 	sa->sin_len = sizeof(*sa);
1444 	sa->sin_addr = addr;
1445 
1446 	sa = (struct sockaddr_in *)(void *)&addreq.ifra_mask;
1447 	sa->sin_family = AF_INET;
1448 	sa->sin_len = sizeof(*sa);
1449 	sa->sin_addr = mask;
1450 
1451 	sa = (struct sockaddr_in *)(void *)&addreq.ifra_broadaddr;
1452 	sa->sin_family = AF_INET;
1453 	sa->sin_len = sizeof(*sa);
1454 	sa->sin_addr = bcast;
1455 
1456 	return (ioctl(mib_netsock, SIOCAIFADDR, &addreq));
1457 }
1458 
1459 /*
1460  * Exececute a SIOCDIFADDR
1461  */
1462 static int
1463 siocdifaddr(const char *ifname, struct in_addr addr)
1464 {
1465 	struct ifreq delreq;
1466 	struct sockaddr_in *sa;
1467 
1468 	memset(&delreq, 0, sizeof(delreq));
1469 	strlcpy(delreq.ifr_name, ifname, sizeof(delreq.ifr_name));
1470 	sa = (struct sockaddr_in *)(void *)&delreq.ifr_addr;
1471 	sa->sin_family = AF_INET;
1472 	sa->sin_len = sizeof(*sa);
1473 	sa->sin_addr = addr;
1474 
1475 	return (ioctl(mib_netsock, SIOCDIFADDR, &delreq));
1476 }
1477 
1478 /*
1479  * Verify an interface address without fetching the entire list
1480  */
1481 static int
1482 verify_ifa(const char *name, struct mibifa *ifa)
1483 {
1484 	struct ifreq req;
1485 	struct sockaddr_in *sa;
1486 
1487 	memset(&req, 0, sizeof(req));
1488 	strlcpy(req.ifr_name, name, sizeof(req.ifr_name));
1489 	sa = (struct sockaddr_in *)(void *)&req.ifr_addr;
1490 	sa->sin_family = AF_INET;
1491 	sa->sin_len = sizeof(*sa);
1492 	sa->sin_addr = ifa->inaddr;
1493 
1494 	if (ioctl(mib_netsock, SIOCGIFADDR, &req) == -1)
1495 		return (-1);
1496 	if (ifa->inaddr.s_addr != sa->sin_addr.s_addr) {
1497 		syslog(LOG_ERR, "%s: address mismatch", __func__);
1498 		return (-1);
1499 	}
1500 
1501 	if (ioctl(mib_netsock, SIOCGIFNETMASK, &req) == -1)
1502 		return (-1);
1503 	if (ifa->inmask.s_addr != sa->sin_addr.s_addr) {
1504 		syslog(LOG_ERR, "%s: netmask mismatch", __func__);
1505 		return (-1);
1506 	}
1507 	return (0);
1508 }
1509 
1510 /*
1511  * Restore a deleted interface address. Don't wait for the routing socket
1512  * to update us.
1513  */
1514 void
1515 mib_undestroy_ifa(struct mibifa *ifa)
1516 {
1517 	struct mibif *ifp;
1518 
1519 	if ((ifp = mib_find_if(ifa->ifindex)) == NULL)
1520 		/* keep it destroyed */
1521 		return;
1522 
1523 	if (siocaifaddr(ifp->name, ifa->inaddr, ifa->inmask, ifa->inbcast))
1524 		/* keep it destroyed */
1525 		return;
1526 
1527 	ifa->flags &= ~MIBIFA_DESTROYED;
1528 }
1529 
1530 /*
1531  * Destroy an interface address
1532  */
1533 int
1534 mib_destroy_ifa(struct mibifa *ifa)
1535 {
1536 	struct mibif *ifp;
1537 
1538 	if ((ifp = mib_find_if(ifa->ifindex)) == NULL) {
1539 		/* ups. */
1540 		mib_iflist_bad = 1;
1541 		return (-1);
1542 	}
1543 	if (siocdifaddr(ifp->name, ifa->inaddr)) {
1544 		/* ups. */
1545 		syslog(LOG_ERR, "SIOCDIFADDR: %m");
1546 		mib_iflist_bad = 1;
1547 		return (-1);
1548 	}
1549 	ifa->flags |= MIBIFA_DESTROYED;
1550 	return (0);
1551 }
1552 
1553 /*
1554  * Rollback the modification of an address. Don't bother to wait for
1555  * the routing socket.
1556  */
1557 void
1558 mib_unmodify_ifa(struct mibifa *ifa)
1559 {
1560 	struct mibif *ifp;
1561 
1562 	if ((ifp = mib_find_if(ifa->ifindex)) == NULL) {
1563 		/* ups. */
1564 		mib_iflist_bad = 1;
1565 		return;
1566 	}
1567 
1568 	if (siocaifaddr(ifp->name, ifa->inaddr, ifa->inmask, ifa->inbcast)) {
1569 		/* ups. */
1570 		mib_iflist_bad = 1;
1571 		return;
1572 	}
1573 }
1574 
1575 /*
1576  * Modify an IFA.
1577  */
1578 int
1579 mib_modify_ifa(struct mibifa *ifa)
1580 {
1581 	struct mibif *ifp;
1582 
1583 	if ((ifp = mib_find_if(ifa->ifindex)) == NULL) {
1584 		/* ups. */
1585 		mib_iflist_bad = 1;
1586 		return (-1);
1587 	}
1588 
1589 	if (siocaifaddr(ifp->name, ifa->inaddr, ifa->inmask, ifa->inbcast)) {
1590 		/* ups. */
1591 		mib_iflist_bad = 1;
1592 		return (-1);
1593 	}
1594 
1595 	if (verify_ifa(ifp->name, ifa)) {
1596 		/* ups. */
1597 		mib_iflist_bad = 1;
1598 		return (-1);
1599 	}
1600 
1601 	return (0);
1602 }
1603 
1604 /*
1605  * Destroy a freshly created interface address. Don't bother to wait for
1606  * the routing socket.
1607  */
1608 void
1609 mib_uncreate_ifa(struct mibifa *ifa)
1610 {
1611 	struct mibif *ifp;
1612 
1613 	if ((ifp = mib_find_if(ifa->ifindex)) == NULL) {
1614 		/* ups. */
1615 		mib_iflist_bad = 1;
1616 		return;
1617 	}
1618 	if (siocdifaddr(ifp->name, ifa->inaddr)) {
1619 		/* ups. */
1620 		mib_iflist_bad = 1;
1621 		return;
1622 	}
1623 
1624 	destroy_ifa(ifa);
1625 }
1626 
1627 /*
1628  * Create a new ifa and verify it
1629  */
1630 struct mibifa *
1631 mib_create_ifa(u_int ifindex, struct in_addr addr, struct in_addr mask,
1632     struct in_addr bcast)
1633 {
1634 	struct mibif *ifp;
1635 	struct mibifa *ifa;
1636 
1637 	if ((ifp = mib_find_if(ifindex)) == NULL)
1638 		return (NULL);
1639 	if ((ifa = alloc_ifa(ifindex, addr)) == NULL)
1640 		return (NULL);
1641 	ifa->inmask = mask;
1642 	ifa->inbcast = bcast;
1643 
1644 	if (siocaifaddr(ifp->name, ifa->inaddr, ifa->inmask, ifa->inbcast)) {
1645 		syslog(LOG_ERR, "%s: %m", __func__);
1646 		destroy_ifa(ifa);
1647 		return (NULL);
1648 	}
1649 	if (verify_ifa(ifp->name, ifa)) {
1650 		destroy_ifa(ifa);
1651 		return (NULL);
1652 	}
1653 	return (ifa);
1654 }
1655 
1656 /*
1657  * Get all cloning interfaces and make them dynamic.
1658  * Hah! Whe should probably do this on a periodic basis (XXX).
1659  */
1660 static void
1661 get_cloners(void)
1662 {
1663 	struct if_clonereq req;
1664 	char *buf, *cp;
1665 	int i;
1666 
1667 	memset(&req, 0, sizeof(req));
1668 	if (ioctl(mib_netsock, SIOCIFGCLONERS, &req) == -1) {
1669 		syslog(LOG_ERR, "get cloners: %m");
1670 		return;
1671 	}
1672 	if ((buf = malloc(req.ifcr_total * IFNAMSIZ)) == NULL) {
1673 		syslog(LOG_ERR, "%m");
1674 		return;
1675 	}
1676 	req.ifcr_count = req.ifcr_total;
1677 	req.ifcr_buffer = buf;
1678 	if (ioctl(mib_netsock, SIOCIFGCLONERS, &req) == -1) {
1679 		syslog(LOG_ERR, "get cloners: %m");
1680 		free(buf);
1681 		return;
1682 	}
1683 	for (cp = buf, i = 0; i < req.ifcr_total; i++, cp += IFNAMSIZ)
1684 		mib_if_set_dyn(cp);
1685 	free(buf);
1686 }
1687 
1688 /*
1689  * Idle function
1690  */
1691 static void
1692 mibII_idle(void *arg __unused)
1693 {
1694 	struct mibifa *ifa;
1695 
1696 	if (mib_iflist_bad) {
1697 		TAILQ_FOREACH(ifa, &mibifa_list, link)
1698 			ifa->flags &= ~MIBIFA_DESTROYED;
1699 
1700 		/* assume, that all cloning interfaces are dynamic */
1701 		get_cloners();
1702 
1703 		mib_refresh_iflist();
1704 		update_ifa_info();
1705 		mib_arp_update();
1706 		mib_iflist_bad = 0;
1707 	}
1708 
1709 	mib_arp_update();
1710 }
1711 
1712 
1713 /*
1714  * Start the module
1715  */
1716 static void
1717 mibII_start(void)
1718 {
1719 	if ((route_fd = fd_select(route, route_input, NULL, module)) == NULL) {
1720 		syslog(LOG_ERR, "fd_select(route): %m");
1721 		return;
1722 	}
1723 	mib_refresh_iflist();
1724 	update_ifa_info();
1725 	mib_arp_update();
1726 	(void)mib_fetch_route();
1727 	mib_iftable_last_change = 0;
1728 	mib_ifstack_last_change = 0;
1729 
1730 	ifmib_reg = or_register(&oid_ifMIB,
1731 	    "The MIB module to describe generic objects for network interface"
1732 	    " sub-layers.", module);
1733 
1734 	ipmib_reg = or_register(&oid_ipMIB,
1735 	   "The MIB module for managing IP and ICMP implementations, but "
1736 	   "excluding their management of IP routes.", module);
1737 
1738 	tcpmib_reg = or_register(&oid_tcpMIB,
1739 	   "The MIB module for managing TCP implementations.", module);
1740 
1741 	udpmib_reg = or_register(&oid_udpMIB,
1742 	   "The MIB module for managing UDP implementations.", module);
1743 
1744 	ipForward_reg = or_register(&oid_ipForward,
1745 	   "The MIB module for the display of CIDR multipath IP Routes.",
1746 	   module);
1747 
1748 	mibII_poll_timer = NULL;
1749 	mibII_poll_ticks = MIBII_POLL_TICKS;
1750 	mibif_restart_mibII_poll_timer();
1751 }
1752 
1753 /*
1754  * Initialize the module
1755  */
1756 static int
1757 mibII_init(struct lmodule *mod, int argc __unused, char *argv[] __unused)
1758 {
1759 	size_t len;
1760 
1761 	module = mod;
1762 
1763 	len = sizeof(clockinfo);
1764 	if (sysctlbyname("kern.clockrate", &clockinfo, &len, NULL, 0) == -1) {
1765 		syslog(LOG_ERR, "kern.clockrate: %m");
1766 		return (-1);
1767 	}
1768 	if (len != sizeof(clockinfo)) {
1769 		syslog(LOG_ERR, "kern.clockrate: wrong size");
1770 		return (-1);
1771 	}
1772 
1773 	if ((route = socket(PF_ROUTE, SOCK_RAW, AF_UNSPEC)) == -1) {
1774 		syslog(LOG_ERR, "PF_ROUTE: %m");
1775 		return (-1);
1776 	}
1777 
1778 	if ((mib_netsock = socket(PF_INET, SOCK_DGRAM, 0)) == -1) {
1779 		syslog(LOG_ERR, "PF_INET: %m");
1780 		(void)close(route);
1781 		return (-1);
1782 	}
1783 	(void)shutdown(mib_netsock, SHUT_RDWR);
1784 
1785 	/* assume, that all cloning interfaces are dynamic */
1786 	get_cloners();
1787 
1788 	return (0);
1789 }
1790 
1791 static int
1792 mibII_fini(void)
1793 {
1794 	if (mibII_poll_timer != NULL ) {
1795 		timer_stop(mibII_poll_timer);
1796 		mibII_poll_timer = NULL;
1797 	}
1798 
1799 	if (route_fd != NULL)
1800 		fd_deselect(route_fd);
1801 	if (route != -1)
1802 		(void)close(route);
1803 	if (mib_netsock != -1)
1804 		(void)close(mib_netsock);
1805 	/* XXX free memory */
1806 
1807 	or_unregister(ipForward_reg);
1808 	or_unregister(udpmib_reg);
1809 	or_unregister(tcpmib_reg);
1810 	or_unregister(ipmib_reg);
1811 	or_unregister(ifmib_reg);
1812 
1813 	return (0);
1814 }
1815 
1816 static void
1817 mibII_loading(const struct lmodule *mod, int loaded)
1818 {
1819 	struct mibif *ifp;
1820 
1821 	if (loaded == 1)
1822 		return;
1823 
1824 	TAILQ_FOREACH(ifp, &mibif_list, link)
1825 		if (ifp->xnotify_mod == mod) {
1826 			ifp->xnotify_mod = NULL;
1827 			ifp->xnotify_data = NULL;
1828 			ifp->xnotify = NULL;
1829 		}
1830 
1831 	mib_unregister_newif(mod);
1832 }
1833 
1834 extern const struct snmp_module config;
1835 const struct snmp_module config = {
1836 	"This module implements the interface and ip groups.",
1837 	mibII_init,
1838 	mibII_fini,
1839 	NULL,		/* idle */
1840 	NULL,		/* dump */
1841 	NULL,		/* config */
1842 	mibII_start,
1843 	NULL,
1844 	mibII_ctree,
1845 	mibII_CTREE_SIZE,
1846 	mibII_loading
1847 };
1848 
1849 /*
1850  * Should have a list of these attached to each interface.
1851  */
1852 void *
1853 mibif_notify(struct mibif *ifp, const struct lmodule *mod,
1854     mibif_notify_f func, void *data)
1855 {
1856 	ifp->xnotify = func;
1857 	ifp->xnotify_data = data;
1858 	ifp->xnotify_mod = mod;
1859 
1860 	return (ifp);
1861 }
1862 
1863 void
1864 mibif_unnotify(void *arg)
1865 {
1866 	struct mibif *ifp = arg;
1867 
1868 	ifp->xnotify = NULL;
1869 	ifp->xnotify_data = NULL;
1870 	ifp->xnotify_mod = NULL;
1871 }
1872