xref: /freebsd/sys/netinet/in.c (revision a98ff317388a00b992f1bf8404dee596f9383f5e)
1 /*-
2  * Copyright (c) 1982, 1986, 1991, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  * Copyright (C) 2001 WIDE Project.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 4. Neither the name of the University nor the names of its contributors
15  *    may be used to endorse or promote products derived from this software
16  *    without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  *
30  *	@(#)in.c	8.4 (Berkeley) 1/9/95
31  */
32 
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 #include "opt_mpath.h"
37 
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/sockio.h>
41 #include <sys/malloc.h>
42 #include <sys/priv.h>
43 #include <sys/socket.h>
44 #include <sys/jail.h>
45 #include <sys/kernel.h>
46 #include <sys/proc.h>
47 #include <sys/sysctl.h>
48 #include <sys/syslog.h>
49 
50 #include <net/if.h>
51 #include <net/if_var.h>
52 #include <net/if_arp.h>
53 #include <net/if_dl.h>
54 #include <net/if_llatbl.h>
55 #include <net/if_types.h>
56 #include <net/route.h>
57 #include <net/vnet.h>
58 
59 #include <netinet/if_ether.h>
60 #include <netinet/in.h>
61 #include <netinet/in_var.h>
62 #include <netinet/in_pcb.h>
63 #include <netinet/ip_var.h>
64 #include <netinet/ip_carp.h>
65 #include <netinet/igmp_var.h>
66 #include <netinet/udp.h>
67 #include <netinet/udp_var.h>
68 
69 static int in_mask2len(struct in_addr *);
70 static void in_len2mask(struct in_addr *, int);
71 static int in_lifaddr_ioctl(struct socket *, u_long, caddr_t,
72 	struct ifnet *, struct thread *);
73 
74 static void	in_socktrim(struct sockaddr_in *);
75 static int	in_ifinit(struct ifnet *, struct in_ifaddr *,
76 		    struct sockaddr_in *, int, int);
77 static void	in_purgemaddrs(struct ifnet *);
78 
79 static VNET_DEFINE(int, nosameprefix);
80 #define	V_nosameprefix			VNET(nosameprefix)
81 SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, no_same_prefix, CTLFLAG_RW,
82 	&VNET_NAME(nosameprefix), 0,
83 	"Refuse to create same prefixes on different interfaces");
84 
85 VNET_DECLARE(struct inpcbinfo, ripcbinfo);
86 #define	V_ripcbinfo			VNET(ripcbinfo)
87 
88 /*
89  * Return 1 if an internet address is for a ``local'' host
90  * (one to which we have a connection).
91  */
92 int
93 in_localaddr(struct in_addr in)
94 {
95 	register u_long i = ntohl(in.s_addr);
96 	register struct in_ifaddr *ia;
97 
98 	IN_IFADDR_RLOCK();
99 	TAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
100 		if ((i & ia->ia_subnetmask) == ia->ia_subnet) {
101 			IN_IFADDR_RUNLOCK();
102 			return (1);
103 		}
104 	}
105 	IN_IFADDR_RUNLOCK();
106 	return (0);
107 }
108 
109 /*
110  * Return 1 if an internet address is for the local host and configured
111  * on one of its interfaces.
112  */
113 int
114 in_localip(struct in_addr in)
115 {
116 	struct in_ifaddr *ia;
117 
118 	IN_IFADDR_RLOCK();
119 	LIST_FOREACH(ia, INADDR_HASH(in.s_addr), ia_hash) {
120 		if (IA_SIN(ia)->sin_addr.s_addr == in.s_addr) {
121 			IN_IFADDR_RUNLOCK();
122 			return (1);
123 		}
124 	}
125 	IN_IFADDR_RUNLOCK();
126 	return (0);
127 }
128 
129 /*
130  * Determine whether an IP address is in a reserved set of addresses
131  * that may not be forwarded, or whether datagrams to that destination
132  * may be forwarded.
133  */
134 int
135 in_canforward(struct in_addr in)
136 {
137 	register u_long i = ntohl(in.s_addr);
138 	register u_long net;
139 
140 	if (IN_EXPERIMENTAL(i) || IN_MULTICAST(i) || IN_LINKLOCAL(i))
141 		return (0);
142 	if (IN_CLASSA(i)) {
143 		net = i & IN_CLASSA_NET;
144 		if (net == 0 || net == (IN_LOOPBACKNET << IN_CLASSA_NSHIFT))
145 			return (0);
146 	}
147 	return (1);
148 }
149 
150 /*
151  * Trim a mask in a sockaddr
152  */
153 static void
154 in_socktrim(struct sockaddr_in *ap)
155 {
156     register char *cplim = (char *) &ap->sin_addr;
157     register char *cp = (char *) (&ap->sin_addr + 1);
158 
159     ap->sin_len = 0;
160     while (--cp >= cplim)
161 	if (*cp) {
162 	    (ap)->sin_len = cp - (char *) (ap) + 1;
163 	    break;
164 	}
165 }
166 
167 static int
168 in_mask2len(mask)
169 	struct in_addr *mask;
170 {
171 	int x, y;
172 	u_char *p;
173 
174 	p = (u_char *)mask;
175 	for (x = 0; x < sizeof(*mask); x++) {
176 		if (p[x] != 0xff)
177 			break;
178 	}
179 	y = 0;
180 	if (x < sizeof(*mask)) {
181 		for (y = 0; y < 8; y++) {
182 			if ((p[x] & (0x80 >> y)) == 0)
183 				break;
184 		}
185 	}
186 	return (x * 8 + y);
187 }
188 
189 static void
190 in_len2mask(struct in_addr *mask, int len)
191 {
192 	int i;
193 	u_char *p;
194 
195 	p = (u_char *)mask;
196 	bzero(mask, sizeof(*mask));
197 	for (i = 0; i < len / 8; i++)
198 		p[i] = 0xff;
199 	if (len % 8)
200 		p[i] = (0xff00 >> (len % 8)) & 0xff;
201 }
202 
203 /*
204  * Generic internet control operations (ioctl's).
205  *
206  * ifp is NULL if not an interface-specific ioctl.
207  */
208 /* ARGSUSED */
209 int
210 in_control(struct socket *so, u_long cmd, caddr_t data, struct ifnet *ifp,
211     struct thread *td)
212 {
213 	register struct ifreq *ifr = (struct ifreq *)data;
214 	register struct in_ifaddr *ia, *iap;
215 	register struct ifaddr *ifa;
216 	struct in_addr allhosts_addr;
217 	struct in_addr dst;
218 	struct in_ifinfo *ii;
219 	struct in_aliasreq *ifra = (struct in_aliasreq *)data;
220 	int error, hostIsNew, iaIsNew, maskIsNew;
221 	int iaIsFirst;
222 	u_long ocmd = cmd;
223 
224 	/*
225 	 * Pre-10.x compat: OSIOCAIFADDR passes a shorter
226 	 * struct in_aliasreq, without ifra_vhid.
227 	 */
228 	if (cmd == OSIOCAIFADDR)
229 		cmd = SIOCAIFADDR;
230 
231 	ia = NULL;
232 	iaIsFirst = 0;
233 	iaIsNew = 0;
234 	allhosts_addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);
235 
236 	/*
237 	 * Filter out ioctls we implement directly; forward the rest on to
238 	 * in_lifaddr_ioctl() and ifp->if_ioctl().
239 	 */
240 	switch (cmd) {
241 	case SIOCGIFADDR:
242 	case SIOCGIFBRDADDR:
243 	case SIOCGIFDSTADDR:
244 	case SIOCGIFNETMASK:
245 	case SIOCDIFADDR:
246 		break;
247 	case SIOCAIFADDR:
248 		/*
249 		 * ifra_addr must be present and be of INET family.
250 		 * ifra_broadaddr and ifra_mask are optional.
251 		 */
252 		if (ifra->ifra_addr.sin_len != sizeof(struct sockaddr_in) ||
253 		    ifra->ifra_addr.sin_family != AF_INET)
254 			return (EINVAL);
255 		if (ifra->ifra_broadaddr.sin_len != 0 &&
256 		    (ifra->ifra_broadaddr.sin_len !=
257 		    sizeof(struct sockaddr_in) ||
258 		    ifra->ifra_broadaddr.sin_family != AF_INET))
259 			return (EINVAL);
260 #if 0
261 		/*
262 		 * ifconfig(8) in pre-10.x doesn't set sin_family for the
263 		 * mask. The code is disabled for the 10.x timeline, to
264 		 * make SIOCAIFADDR compatible with 9.x ifconfig(8).
265 		 * The code should be enabled in 11.x
266 		 */
267 		if (ifra->ifra_mask.sin_len != 0 &&
268 		    (ifra->ifra_mask.sin_len != sizeof(struct sockaddr_in) ||
269 		    ifra->ifra_mask.sin_family != AF_INET))
270 			return (EINVAL);
271 #endif
272 		break;
273 	case SIOCSIFADDR:
274 	case SIOCSIFBRDADDR:
275 	case SIOCSIFDSTADDR:
276 	case SIOCSIFNETMASK:
277 		/* We no longer support that old commands. */
278 		return (EINVAL);
279 
280 	case SIOCALIFADDR:
281 		if (td != NULL) {
282 			error = priv_check(td, PRIV_NET_ADDIFADDR);
283 			if (error)
284 				return (error);
285 		}
286 		if (ifp == NULL)
287 			return (EINVAL);
288 		return in_lifaddr_ioctl(so, cmd, data, ifp, td);
289 
290 	case SIOCDLIFADDR:
291 		if (td != NULL) {
292 			error = priv_check(td, PRIV_NET_DELIFADDR);
293 			if (error)
294 				return (error);
295 		}
296 		if (ifp == NULL)
297 			return (EINVAL);
298 		return in_lifaddr_ioctl(so, cmd, data, ifp, td);
299 
300 	case SIOCGLIFADDR:
301 		if (ifp == NULL)
302 			return (EINVAL);
303 		return in_lifaddr_ioctl(so, cmd, data, ifp, td);
304 
305 	default:
306 		if (ifp == NULL || ifp->if_ioctl == NULL)
307 			return (EOPNOTSUPP);
308 		return ((*ifp->if_ioctl)(ifp, cmd, data));
309 	}
310 
311 	if (ifp == NULL)
312 		return (EADDRNOTAVAIL);
313 
314 	/*
315 	 * Security checks before we get involved in any work.
316 	 */
317 	switch (cmd) {
318 	case SIOCAIFADDR:
319 		if (td != NULL) {
320 			error = priv_check(td, PRIV_NET_ADDIFADDR);
321 			if (error)
322 				return (error);
323 		}
324 		break;
325 
326 	case SIOCDIFADDR:
327 		if (td != NULL) {
328 			error = priv_check(td, PRIV_NET_DELIFADDR);
329 			if (error)
330 				return (error);
331 		}
332 		break;
333 	}
334 
335 	/*
336 	 * Find address for this interface, if it exists.
337 	 *
338 	 * If an alias address was specified, find that one instead of the
339 	 * first one on the interface, if possible.
340 	 */
341 	dst = ((struct sockaddr_in *)&ifr->ifr_addr)->sin_addr;
342 	IN_IFADDR_RLOCK();
343 	LIST_FOREACH(iap, INADDR_HASH(dst.s_addr), ia_hash) {
344 		if (iap->ia_ifp == ifp &&
345 		    iap->ia_addr.sin_addr.s_addr == dst.s_addr) {
346 			if (td == NULL || prison_check_ip4(td->td_ucred,
347 			    &dst) == 0)
348 				ia = iap;
349 			break;
350 		}
351 	}
352 	if (ia != NULL)
353 		ifa_ref(&ia->ia_ifa);
354 	IN_IFADDR_RUNLOCK();
355 	if (ia == NULL) {
356 		IF_ADDR_RLOCK(ifp);
357 		TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
358 			iap = ifatoia(ifa);
359 			if (iap->ia_addr.sin_family == AF_INET) {
360 				if (td != NULL &&
361 				    prison_check_ip4(td->td_ucred,
362 				    &iap->ia_addr.sin_addr) != 0)
363 					continue;
364 				ia = iap;
365 				break;
366 			}
367 		}
368 		if (ia != NULL)
369 			ifa_ref(&ia->ia_ifa);
370 		IF_ADDR_RUNLOCK(ifp);
371 	}
372 	if (ia == NULL)
373 		iaIsFirst = 1;
374 
375 	error = 0;
376 	switch (cmd) {
377 	case SIOCAIFADDR:
378 	case SIOCDIFADDR:
379 		if (ifra->ifra_addr.sin_family == AF_INET) {
380 			struct in_ifaddr *oia;
381 
382 			IN_IFADDR_RLOCK();
383 			for (oia = ia; ia; ia = TAILQ_NEXT(ia, ia_link)) {
384 				if (ia->ia_ifp == ifp  &&
385 				    ia->ia_addr.sin_addr.s_addr ==
386 				    ifra->ifra_addr.sin_addr.s_addr)
387 					break;
388 			}
389 			if (ia != NULL && ia != oia)
390 				ifa_ref(&ia->ia_ifa);
391 			if (oia != NULL && ia != oia)
392 				ifa_free(&oia->ia_ifa);
393 			IN_IFADDR_RUNLOCK();
394 			if ((ifp->if_flags & IFF_POINTOPOINT)
395 			    && (cmd == SIOCAIFADDR)
396 			    && (ifra->ifra_dstaddr.sin_addr.s_addr
397 				== INADDR_ANY)) {
398 				error = EDESTADDRREQ;
399 				goto out;
400 			}
401 		}
402 		if (cmd == SIOCDIFADDR && ia == NULL) {
403 			error = EADDRNOTAVAIL;
404 			goto out;
405 		}
406 		if (ia == NULL) {
407 			ia = (struct in_ifaddr *)
408 				malloc(sizeof *ia, M_IFADDR, M_NOWAIT |
409 				    M_ZERO);
410 			if (ia == NULL) {
411 				error = ENOBUFS;
412 				goto out;
413 			}
414 
415 			ifa = &ia->ia_ifa;
416 			ifa_init(ifa);
417 			ifa->ifa_addr = (struct sockaddr *)&ia->ia_addr;
418 			ifa->ifa_dstaddr = (struct sockaddr *)&ia->ia_dstaddr;
419 			ifa->ifa_netmask = (struct sockaddr *)&ia->ia_sockmask;
420 
421 			ia->ia_sockmask.sin_len = 8;
422 			ia->ia_sockmask.sin_family = AF_INET;
423 			if (ifp->if_flags & IFF_BROADCAST) {
424 				ia->ia_broadaddr.sin_len = sizeof(ia->ia_addr);
425 				ia->ia_broadaddr.sin_family = AF_INET;
426 			}
427 			ia->ia_ifp = ifp;
428 
429 			ifa_ref(ifa);			/* if_addrhead */
430 			IF_ADDR_WLOCK(ifp);
431 			TAILQ_INSERT_TAIL(&ifp->if_addrhead, ifa, ifa_link);
432 			IF_ADDR_WUNLOCK(ifp);
433 			ifa_ref(ifa);			/* in_ifaddrhead */
434 			IN_IFADDR_WLOCK();
435 			TAILQ_INSERT_TAIL(&V_in_ifaddrhead, ia, ia_link);
436 			IN_IFADDR_WUNLOCK();
437 			iaIsNew = 1;
438 		}
439 		break;
440 
441 	case SIOCGIFADDR:
442 	case SIOCGIFNETMASK:
443 	case SIOCGIFDSTADDR:
444 	case SIOCGIFBRDADDR:
445 		if (ia == NULL) {
446 			error = EADDRNOTAVAIL;
447 			goto out;
448 		}
449 		break;
450 	}
451 
452 	/*
453 	 * Most paths in this switch return directly or via out.  Only paths
454 	 * that remove the address break in order to hit common removal code.
455 	 */
456 	switch (cmd) {
457 	case SIOCGIFADDR:
458 		*((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_addr;
459 		goto out;
460 
461 	case SIOCGIFBRDADDR:
462 		if ((ifp->if_flags & IFF_BROADCAST) == 0) {
463 			error = EINVAL;
464 			goto out;
465 		}
466 		*((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_broadaddr;
467 		goto out;
468 
469 	case SIOCGIFDSTADDR:
470 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0) {
471 			error = EINVAL;
472 			goto out;
473 		}
474 		*((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_dstaddr;
475 		goto out;
476 
477 	case SIOCGIFNETMASK:
478 		*((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_sockmask;
479 		goto out;
480 
481 	case SIOCAIFADDR:
482 		maskIsNew = 0;
483 		hostIsNew = 1;
484 		error = 0;
485 		if (ifra->ifra_addr.sin_addr.s_addr ==
486 			    ia->ia_addr.sin_addr.s_addr)
487 			hostIsNew = 0;
488 		if (ifra->ifra_mask.sin_len) {
489 			/*
490 			 * QL: XXX
491 			 * Need to scrub the prefix here in case
492 			 * the issued command is SIOCAIFADDR with
493 			 * the same address, but with a different
494 			 * prefix length. And if the prefix length
495 			 * is the same as before, then the call is
496 			 * un-necessarily executed here.
497 			 */
498 			in_ifscrub(ifp, ia, LLE_STATIC);
499 			ia->ia_sockmask = ifra->ifra_mask;
500 			ia->ia_sockmask.sin_family = AF_INET;
501 			ia->ia_subnetmask =
502 			    ntohl(ia->ia_sockmask.sin_addr.s_addr);
503 			maskIsNew = 1;
504 		}
505 		if ((ifp->if_flags & IFF_POINTOPOINT) &&
506 		    (ifra->ifra_dstaddr.sin_family == AF_INET)) {
507 			in_ifscrub(ifp, ia, LLE_STATIC);
508 			ia->ia_dstaddr = ifra->ifra_dstaddr;
509 			maskIsNew  = 1; /* We lie; but the effect's the same */
510 		}
511 		if (hostIsNew || maskIsNew)
512 			error = in_ifinit(ifp, ia, &ifra->ifra_addr, maskIsNew,
513 			    (ocmd == cmd ? ifra->ifra_vhid : 0));
514 		if (error != 0 && iaIsNew)
515 			break;
516 
517 		if ((ifp->if_flags & IFF_BROADCAST) &&
518 		    ifra->ifra_broadaddr.sin_len)
519 			ia->ia_broadaddr = ifra->ifra_broadaddr;
520 		if (error == 0) {
521 			ii = ((struct in_ifinfo *)ifp->if_afdata[AF_INET]);
522 			if (iaIsFirst &&
523 			    (ifp->if_flags & IFF_MULTICAST) != 0) {
524 				error = in_joingroup(ifp, &allhosts_addr,
525 				    NULL, &ii->ii_allhosts);
526 			}
527 			EVENTHANDLER_INVOKE(ifaddr_event, ifp);
528 		}
529 		goto out;
530 
531 	case SIOCDIFADDR:
532 		/*
533 		 * in_ifscrub kills the interface route.
534 		 */
535 		in_ifscrub(ifp, ia, LLE_STATIC);
536 
537 		/*
538 		 * in_ifadown gets rid of all the rest of
539 		 * the routes.  This is not quite the right
540 		 * thing to do, but at least if we are running
541 		 * a routing process they will come back.
542 		 */
543 		in_ifadown(&ia->ia_ifa, 1);
544 		EVENTHANDLER_INVOKE(ifaddr_event, ifp);
545 		error = 0;
546 		break;
547 
548 	default:
549 		panic("in_control: unsupported ioctl");
550 	}
551 
552 	if (ia->ia_ifa.ifa_carp)
553 		(*carp_detach_p)(&ia->ia_ifa);
554 
555 	IF_ADDR_WLOCK(ifp);
556 	/* Re-check that ia is still part of the list. */
557 	TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
558 		if (ifa == &ia->ia_ifa)
559 			break;
560 	}
561 	if (ifa == NULL) {
562 		/*
563 		 * If we lost the race with another thread, there is no need to
564 		 * try it again for the next loop as there is no other exit
565 		 * path between here and out.
566 		 */
567 		IF_ADDR_WUNLOCK(ifp);
568 		error = EADDRNOTAVAIL;
569 		goto out;
570 	}
571 	TAILQ_REMOVE(&ifp->if_addrhead, &ia->ia_ifa, ifa_link);
572 	IF_ADDR_WUNLOCK(ifp);
573 	ifa_free(&ia->ia_ifa);		      /* if_addrhead */
574 
575 	IN_IFADDR_WLOCK();
576 	TAILQ_REMOVE(&V_in_ifaddrhead, ia, ia_link);
577 
578 	LIST_REMOVE(ia, ia_hash);
579 	IN_IFADDR_WUNLOCK();
580 	/*
581 	 * If this is the last IPv4 address configured on this
582 	 * interface, leave the all-hosts group.
583 	 * No state-change report need be transmitted.
584 	 */
585 	IFP_TO_IA(ifp, iap);
586 	if (iap == NULL) {
587 		ii = ((struct in_ifinfo *)ifp->if_afdata[AF_INET]);
588 		IN_MULTI_LOCK();
589 		if (ii->ii_allhosts) {
590 			(void)in_leavegroup_locked(ii->ii_allhosts, NULL);
591 			ii->ii_allhosts = NULL;
592 		}
593 		IN_MULTI_UNLOCK();
594 	} else
595 		ifa_free(&iap->ia_ifa);
596 
597 	ifa_free(&ia->ia_ifa);				/* in_ifaddrhead */
598 out:
599 	if (ia != NULL)
600 		ifa_free(&ia->ia_ifa);
601 	return (error);
602 }
603 
604 /*
605  * SIOC[GAD]LIFADDR.
606  *	SIOCGLIFADDR: get first address. (?!?)
607  *	SIOCGLIFADDR with IFLR_PREFIX:
608  *		get first address that matches the specified prefix.
609  *	SIOCALIFADDR: add the specified address.
610  *	SIOCALIFADDR with IFLR_PREFIX:
611  *		EINVAL since we can't deduce hostid part of the address.
612  *	SIOCDLIFADDR: delete the specified address.
613  *	SIOCDLIFADDR with IFLR_PREFIX:
614  *		delete the first address that matches the specified prefix.
615  * return values:
616  *	EINVAL on invalid parameters
617  *	EADDRNOTAVAIL on prefix match failed/specified address not found
618  *	other values may be returned from in_ioctl()
619  */
620 static int
621 in_lifaddr_ioctl(struct socket *so, u_long cmd, caddr_t data,
622     struct ifnet *ifp, struct thread *td)
623 {
624 	struct if_laddrreq *iflr = (struct if_laddrreq *)data;
625 	struct ifaddr *ifa;
626 
627 	/* sanity checks */
628 	if (data == NULL || ifp == NULL) {
629 		panic("invalid argument to in_lifaddr_ioctl");
630 		/*NOTRECHED*/
631 	}
632 
633 	switch (cmd) {
634 	case SIOCGLIFADDR:
635 		/* address must be specified on GET with IFLR_PREFIX */
636 		if ((iflr->flags & IFLR_PREFIX) == 0)
637 			break;
638 		/*FALLTHROUGH*/
639 	case SIOCALIFADDR:
640 	case SIOCDLIFADDR:
641 		/* address must be specified on ADD and DELETE */
642 		if (iflr->addr.ss_family != AF_INET)
643 			return (EINVAL);
644 		if (iflr->addr.ss_len != sizeof(struct sockaddr_in))
645 			return (EINVAL);
646 		/* XXX need improvement */
647 		if (iflr->dstaddr.ss_family
648 		 && iflr->dstaddr.ss_family != AF_INET)
649 			return (EINVAL);
650 		if (iflr->dstaddr.ss_family
651 		 && iflr->dstaddr.ss_len != sizeof(struct sockaddr_in))
652 			return (EINVAL);
653 		break;
654 	default: /*shouldn't happen*/
655 		return (EOPNOTSUPP);
656 	}
657 	if (sizeof(struct in_addr) * 8 < iflr->prefixlen)
658 		return (EINVAL);
659 
660 	switch (cmd) {
661 	case SIOCALIFADDR:
662 	    {
663 		struct in_aliasreq ifra;
664 
665 		if (iflr->flags & IFLR_PREFIX)
666 			return (EINVAL);
667 
668 		/* copy args to in_aliasreq, perform ioctl(SIOCAIFADDR). */
669 		bzero(&ifra, sizeof(ifra));
670 		bcopy(iflr->iflr_name, ifra.ifra_name,
671 			sizeof(ifra.ifra_name));
672 
673 		bcopy(&iflr->addr, &ifra.ifra_addr, iflr->addr.ss_len);
674 
675 		if (iflr->dstaddr.ss_family) {	/*XXX*/
676 			bcopy(&iflr->dstaddr, &ifra.ifra_dstaddr,
677 				iflr->dstaddr.ss_len);
678 		}
679 
680 		ifra.ifra_mask.sin_family = AF_INET;
681 		ifra.ifra_mask.sin_len = sizeof(struct sockaddr_in);
682 		in_len2mask(&ifra.ifra_mask.sin_addr, iflr->prefixlen);
683 
684 		return (in_control(so, SIOCAIFADDR, (caddr_t)&ifra, ifp, td));
685 	    }
686 	case SIOCGLIFADDR:
687 	case SIOCDLIFADDR:
688 	    {
689 		struct in_ifaddr *ia;
690 		struct in_addr mask, candidate, match;
691 		struct sockaddr_in *sin;
692 
693 		bzero(&mask, sizeof(mask));
694 		bzero(&match, sizeof(match));
695 		if (iflr->flags & IFLR_PREFIX) {
696 			/* lookup a prefix rather than address. */
697 			in_len2mask(&mask, iflr->prefixlen);
698 
699 			sin = (struct sockaddr_in *)&iflr->addr;
700 			match.s_addr = sin->sin_addr.s_addr;
701 			match.s_addr &= mask.s_addr;
702 
703 			/* if you set extra bits, that's wrong */
704 			if (match.s_addr != sin->sin_addr.s_addr)
705 				return (EINVAL);
706 
707 		} else {
708 			/* on getting an address, take the 1st match */
709 			/* on deleting an address, do exact match */
710 			if (cmd != SIOCGLIFADDR) {
711 				in_len2mask(&mask, 32);
712 				sin = (struct sockaddr_in *)&iflr->addr;
713 				match.s_addr = sin->sin_addr.s_addr;
714 			}
715 		}
716 
717 		IF_ADDR_RLOCK(ifp);
718 		TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)	{
719 			if (ifa->ifa_addr->sa_family != AF_INET)
720 				continue;
721 			if (match.s_addr == 0)
722 				break;
723 			sin = (struct sockaddr_in *)&ifa->ifa_addr;
724 			candidate.s_addr = sin->sin_addr.s_addr;
725 			candidate.s_addr &= mask.s_addr;
726 			if (candidate.s_addr == match.s_addr)
727 				break;
728 		}
729 		if (ifa != NULL)
730 			ifa_ref(ifa);
731 		IF_ADDR_RUNLOCK(ifp);
732 		if (ifa == NULL)
733 			return (EADDRNOTAVAIL);
734 		ia = (struct in_ifaddr *)ifa;
735 
736 		if (cmd == SIOCGLIFADDR) {
737 			/* fill in the if_laddrreq structure */
738 			bcopy(&ia->ia_addr, &iflr->addr, ia->ia_addr.sin_len);
739 
740 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
741 				bcopy(&ia->ia_dstaddr, &iflr->dstaddr,
742 					ia->ia_dstaddr.sin_len);
743 			} else
744 				bzero(&iflr->dstaddr, sizeof(iflr->dstaddr));
745 
746 			iflr->prefixlen =
747 				in_mask2len(&ia->ia_sockmask.sin_addr);
748 
749 			iflr->flags = 0;	/*XXX*/
750 			ifa_free(ifa);
751 
752 			return (0);
753 		} else {
754 			struct in_aliasreq ifra;
755 
756 			/* fill in_aliasreq and do ioctl(SIOCDIFADDR) */
757 			bzero(&ifra, sizeof(ifra));
758 			bcopy(iflr->iflr_name, ifra.ifra_name,
759 				sizeof(ifra.ifra_name));
760 
761 			bcopy(&ia->ia_addr, &ifra.ifra_addr,
762 				ia->ia_addr.sin_len);
763 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
764 				bcopy(&ia->ia_dstaddr, &ifra.ifra_dstaddr,
765 					ia->ia_dstaddr.sin_len);
766 			}
767 			bcopy(&ia->ia_sockmask, &ifra.ifra_dstaddr,
768 				ia->ia_sockmask.sin_len);
769 			ifa_free(ifa);
770 
771 			return (in_control(so, SIOCDIFADDR, (caddr_t)&ifra,
772 			    ifp, td));
773 		}
774 	    }
775 	}
776 
777 	return (EOPNOTSUPP);	/*just for safety*/
778 }
779 
780 /*
781  * Delete any existing route for an interface.
782  */
783 void
784 in_ifscrub(struct ifnet *ifp, struct in_ifaddr *ia, u_int flags)
785 {
786 
787 	in_scrubprefix(ia, flags);
788 }
789 
790 /*
791  * Initialize an interface's internet address
792  * and routing table entry.
793  */
794 static int
795 in_ifinit(struct ifnet *ifp, struct in_ifaddr *ia, struct sockaddr_in *sin,
796     int masksupplied, int vhid)
797 {
798 	register u_long i = ntohl(sin->sin_addr.s_addr);
799 	int flags, error = 0;
800 
801 	IN_IFADDR_WLOCK();
802 	if (ia->ia_addr.sin_family == AF_INET)
803 		LIST_REMOVE(ia, ia_hash);
804 	ia->ia_addr = *sin;
805 	LIST_INSERT_HEAD(INADDR_HASH(ia->ia_addr.sin_addr.s_addr),
806 	    ia, ia_hash);
807 	IN_IFADDR_WUNLOCK();
808 
809 	if (vhid > 0) {
810 		if (carp_attach_p != NULL)
811 			error = (*carp_attach_p)(&ia->ia_ifa, vhid);
812 		else
813 			error = EPROTONOSUPPORT;
814 	}
815 	if (error)
816 		return (error);
817 
818 	/*
819 	 * Give the interface a chance to initialize
820 	 * if this is its first address,
821 	 * and to validate the address if necessary.
822 	 */
823 	if (ifp->if_ioctl != NULL &&
824 	    (error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia)) != 0)
825 			/* LIST_REMOVE(ia, ia_hash) is done in in_control */
826 			return (error);
827 
828 	/*
829 	 * Be compatible with network classes, if netmask isn't supplied,
830 	 * guess it based on classes.
831 	 */
832 	if (!masksupplied) {
833 		if (IN_CLASSA(i))
834 			ia->ia_subnetmask = IN_CLASSA_NET;
835 		else if (IN_CLASSB(i))
836 			ia->ia_subnetmask = IN_CLASSB_NET;
837 		else
838 			ia->ia_subnetmask = IN_CLASSC_NET;
839 		ia->ia_sockmask.sin_addr.s_addr = htonl(ia->ia_subnetmask);
840 	}
841 	ia->ia_subnet = i & ia->ia_subnetmask;
842 	in_socktrim(&ia->ia_sockmask);
843 
844 	/*
845 	 * Add route for the network.
846 	 */
847 	flags = RTF_UP;
848 	ia->ia_ifa.ifa_metric = ifp->if_metric;
849 	if (ifp->if_flags & IFF_BROADCAST) {
850 		if (ia->ia_subnetmask == IN_RFC3021_MASK)
851 			ia->ia_broadaddr.sin_addr.s_addr = INADDR_BROADCAST;
852 		else
853 			ia->ia_broadaddr.sin_addr.s_addr =
854 			    htonl(ia->ia_subnet | ~ia->ia_subnetmask);
855 	} else if (ifp->if_flags & IFF_LOOPBACK) {
856 		ia->ia_dstaddr = ia->ia_addr;
857 		flags |= RTF_HOST;
858 	} else if (ifp->if_flags & IFF_POINTOPOINT) {
859 		if (ia->ia_dstaddr.sin_family != AF_INET)
860 			return (0);
861 		flags |= RTF_HOST;
862 	}
863 	if (!vhid && (error = in_addprefix(ia, flags)) != 0)
864 		return (error);
865 
866 	if (ia->ia_addr.sin_addr.s_addr == INADDR_ANY)
867 		return (0);
868 
869 	if (ifp->if_flags & IFF_POINTOPOINT &&
870 	    ia->ia_dstaddr.sin_addr.s_addr == ia->ia_addr.sin_addr.s_addr)
871 			return (0);
872 
873 	/*
874 	 * add a loopback route to self
875 	 */
876 	if (V_useloopback && !vhid && !(ifp->if_flags & IFF_LOOPBACK)) {
877 		struct route ia_ro;
878 
879 		bzero(&ia_ro, sizeof(ia_ro));
880 		*((struct sockaddr_in *)(&ia_ro.ro_dst)) = ia->ia_addr;
881 		rtalloc_ign_fib(&ia_ro, 0, RT_DEFAULT_FIB);
882 		if ((ia_ro.ro_rt != NULL) && (ia_ro.ro_rt->rt_ifp != NULL) &&
883 		    (ia_ro.ro_rt->rt_ifp == V_loif)) {
884 			RT_LOCK(ia_ro.ro_rt);
885 			RT_ADDREF(ia_ro.ro_rt);
886 			RTFREE_LOCKED(ia_ro.ro_rt);
887 		} else
888 			error = ifa_add_loopback_route((struct ifaddr *)ia,
889 			    (struct sockaddr *)&ia->ia_addr);
890 		if (error == 0)
891 			ia->ia_flags |= IFA_RTSELF;
892 		if (ia_ro.ro_rt != NULL)
893 			RTFREE(ia_ro.ro_rt);
894 	}
895 
896 	return (error);
897 }
898 
899 #define rtinitflags(x) \
900 	((((x)->ia_ifp->if_flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) != 0) \
901 	    ? RTF_HOST : 0)
902 
903 /*
904  * Generate a routing message when inserting or deleting
905  * an interface address alias.
906  */
907 static void in_addralias_rtmsg(int cmd, struct in_addr *prefix,
908     struct in_ifaddr *target)
909 {
910 	struct route pfx_ro;
911 	struct sockaddr_in *pfx_addr;
912 	struct rtentry msg_rt;
913 
914 	/* QL: XXX
915 	 * This is a bit questionable because there is no
916 	 * additional route entry added/deleted for an address
917 	 * alias. Therefore this route report is inaccurate.
918 	 */
919 	bzero(&pfx_ro, sizeof(pfx_ro));
920 	pfx_addr = (struct sockaddr_in *)(&pfx_ro.ro_dst);
921 	pfx_addr->sin_len = sizeof(*pfx_addr);
922 	pfx_addr->sin_family = AF_INET;
923 	pfx_addr->sin_addr = *prefix;
924 	rtalloc_ign_fib(&pfx_ro, 0, 0);
925 	if (pfx_ro.ro_rt != NULL) {
926 		msg_rt = *pfx_ro.ro_rt;
927 
928 		/* QL: XXX
929 		 * Point the gateway to the new interface
930 		 * address as if a new prefix route entry has
931 		 * been added through the new address alias.
932 		 * All other parts of the rtentry is accurate,
933 		 * e.g., rt_key, rt_mask, rt_ifp etc.
934 		 */
935 		msg_rt.rt_gateway = (struct sockaddr *)&target->ia_addr;
936 		rt_newaddrmsg(cmd, (struct ifaddr *)target, 0, &msg_rt);
937 		RTFREE(pfx_ro.ro_rt);
938 	}
939 	return;
940 }
941 
942 /*
943  * Check if we have a route for the given prefix already or add one accordingly.
944  */
945 int
946 in_addprefix(struct in_ifaddr *target, int flags)
947 {
948 	struct in_ifaddr *ia;
949 	struct in_addr prefix, mask, p, m;
950 	int error;
951 
952 	if ((flags & RTF_HOST) != 0) {
953 		prefix = target->ia_dstaddr.sin_addr;
954 		mask.s_addr = 0;
955 	} else {
956 		prefix = target->ia_addr.sin_addr;
957 		mask = target->ia_sockmask.sin_addr;
958 		prefix.s_addr &= mask.s_addr;
959 	}
960 
961 	IN_IFADDR_RLOCK();
962 	TAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
963 		if (rtinitflags(ia)) {
964 			p = ia->ia_dstaddr.sin_addr;
965 
966 			if (prefix.s_addr != p.s_addr)
967 				continue;
968 		} else {
969 			p = ia->ia_addr.sin_addr;
970 			m = ia->ia_sockmask.sin_addr;
971 			p.s_addr &= m.s_addr;
972 
973 			if (prefix.s_addr != p.s_addr ||
974 			    mask.s_addr != m.s_addr)
975 				continue;
976 		}
977 
978 		/*
979 		 * If we got a matching prefix route inserted by other
980 		 * interface address, we are done here.
981 		 */
982 		if (ia->ia_flags & IFA_ROUTE) {
983 #ifdef RADIX_MPATH
984 			if (ia->ia_addr.sin_addr.s_addr ==
985 			    target->ia_addr.sin_addr.s_addr) {
986 				IN_IFADDR_RUNLOCK();
987 				return (EEXIST);
988 			} else
989 				break;
990 #endif
991 			if (V_nosameprefix) {
992 				IN_IFADDR_RUNLOCK();
993 				return (EEXIST);
994 			} else {
995 				in_addralias_rtmsg(RTM_ADD, &prefix, target);
996 				IN_IFADDR_RUNLOCK();
997 				return (0);
998 			}
999 		}
1000 	}
1001 	IN_IFADDR_RUNLOCK();
1002 
1003 	/*
1004 	 * No-one seem to have this prefix route, so we try to insert it.
1005 	 */
1006 	error = rtinit(&target->ia_ifa, (int)RTM_ADD, flags);
1007 	if (!error)
1008 		target->ia_flags |= IFA_ROUTE;
1009 	return (error);
1010 }
1011 
1012 /*
1013  * If there is no other address in the system that can serve a route to the
1014  * same prefix, remove the route.  Hand over the route to the new address
1015  * otherwise.
1016  */
1017 int
1018 in_scrubprefix(struct in_ifaddr *target, u_int flags)
1019 {
1020 	struct in_ifaddr *ia;
1021 	struct in_addr prefix, mask, p, m;
1022 	int error = 0;
1023 	struct sockaddr_in prefix0, mask0;
1024 
1025 	/*
1026 	 * Remove the loopback route to the interface address.
1027 	 * The "useloopback" setting is not consulted because if the
1028 	 * user configures an interface address, turns off this
1029 	 * setting, and then tries to delete that interface address,
1030 	 * checking the current setting of "useloopback" would leave
1031 	 * that interface address loopback route untouched, which
1032 	 * would be wrong. Therefore the interface address loopback route
1033 	 * deletion is unconditional.
1034 	 */
1035 	if ((target->ia_addr.sin_addr.s_addr != INADDR_ANY) &&
1036 	    !(target->ia_ifp->if_flags & IFF_LOOPBACK) &&
1037 	    (target->ia_flags & IFA_RTSELF)) {
1038 		struct route ia_ro;
1039 		int freeit = 0;
1040 
1041 		bzero(&ia_ro, sizeof(ia_ro));
1042 		*((struct sockaddr_in *)(&ia_ro.ro_dst)) = target->ia_addr;
1043 		rtalloc_ign_fib(&ia_ro, 0, 0);
1044 		if ((ia_ro.ro_rt != NULL) && (ia_ro.ro_rt->rt_ifp != NULL) &&
1045 		    (ia_ro.ro_rt->rt_ifp == V_loif)) {
1046 			RT_LOCK(ia_ro.ro_rt);
1047 			if (ia_ro.ro_rt->rt_refcnt <= 1)
1048 				freeit = 1;
1049 			else if (flags & LLE_STATIC) {
1050 				RT_REMREF(ia_ro.ro_rt);
1051 				target->ia_flags &= ~IFA_RTSELF;
1052 			}
1053 			RTFREE_LOCKED(ia_ro.ro_rt);
1054 		}
1055 		if (freeit && (flags & LLE_STATIC)) {
1056 			error = ifa_del_loopback_route((struct ifaddr *)target,
1057 			    (struct sockaddr *)&target->ia_addr);
1058 			if (error == 0)
1059 				target->ia_flags &= ~IFA_RTSELF;
1060 		}
1061 		if ((flags & LLE_STATIC) &&
1062 			!(target->ia_ifp->if_flags & IFF_NOARP))
1063 			/* remove arp cache */
1064 			arp_ifscrub(target->ia_ifp, IA_SIN(target)->sin_addr.s_addr);
1065 	}
1066 
1067 	if (rtinitflags(target)) {
1068 		prefix = target->ia_dstaddr.sin_addr;
1069 		mask.s_addr = 0;
1070 	} else {
1071 		prefix = target->ia_addr.sin_addr;
1072 		mask = target->ia_sockmask.sin_addr;
1073 		prefix.s_addr &= mask.s_addr;
1074 	}
1075 
1076 	if ((target->ia_flags & IFA_ROUTE) == 0) {
1077 		in_addralias_rtmsg(RTM_DELETE, &prefix, target);
1078 		return (0);
1079 	}
1080 
1081 	IN_IFADDR_RLOCK();
1082 	TAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
1083 		if (rtinitflags(ia)) {
1084 			p = ia->ia_dstaddr.sin_addr;
1085 
1086 			if (prefix.s_addr != p.s_addr)
1087 				continue;
1088 		} else {
1089 			p = ia->ia_addr.sin_addr;
1090 			m = ia->ia_sockmask.sin_addr;
1091 			p.s_addr &= m.s_addr;
1092 
1093 			if (prefix.s_addr != p.s_addr ||
1094 			    mask.s_addr != m.s_addr)
1095 				continue;
1096 		}
1097 
1098 		if ((ia->ia_ifp->if_flags & IFF_UP) == 0)
1099 			continue;
1100 
1101 		/*
1102 		 * If we got a matching prefix address, move IFA_ROUTE and
1103 		 * the route itself to it.  Make sure that routing daemons
1104 		 * get a heads-up.
1105 		 */
1106 		if ((ia->ia_flags & IFA_ROUTE) == 0) {
1107 			ifa_ref(&ia->ia_ifa);
1108 			IN_IFADDR_RUNLOCK();
1109 			error = rtinit(&(target->ia_ifa), (int)RTM_DELETE,
1110 			    rtinitflags(target));
1111 			if (error == 0)
1112 				target->ia_flags &= ~IFA_ROUTE;
1113 			else
1114 				log(LOG_INFO, "in_scrubprefix: err=%d, old prefix delete failed\n",
1115 					error);
1116 			error = rtinit(&ia->ia_ifa, (int)RTM_ADD,
1117 			    rtinitflags(ia) | RTF_UP);
1118 			if (error == 0)
1119 				ia->ia_flags |= IFA_ROUTE;
1120 			else
1121 				log(LOG_INFO, "in_scrubprefix: err=%d, new prefix add failed\n",
1122 					error);
1123 			ifa_free(&ia->ia_ifa);
1124 			return (error);
1125 		}
1126 	}
1127 	IN_IFADDR_RUNLOCK();
1128 
1129 	/*
1130 	 * remove all L2 entries on the given prefix
1131 	 */
1132 	bzero(&prefix0, sizeof(prefix0));
1133 	prefix0.sin_len = sizeof(prefix0);
1134 	prefix0.sin_family = AF_INET;
1135 	prefix0.sin_addr.s_addr = target->ia_subnet;
1136 	bzero(&mask0, sizeof(mask0));
1137 	mask0.sin_len = sizeof(mask0);
1138 	mask0.sin_family = AF_INET;
1139 	mask0.sin_addr.s_addr = target->ia_subnetmask;
1140 	lltable_prefix_free(AF_INET, (struct sockaddr *)&prefix0,
1141 	    (struct sockaddr *)&mask0, flags);
1142 
1143 	/*
1144 	 * As no-one seem to have this prefix, we can remove the route.
1145 	 */
1146 	error = rtinit(&(target->ia_ifa), (int)RTM_DELETE, rtinitflags(target));
1147 	if (error == 0)
1148 		target->ia_flags &= ~IFA_ROUTE;
1149 	else
1150 		log(LOG_INFO, "in_scrubprefix: err=%d, prefix delete failed\n", error);
1151 	return (error);
1152 }
1153 
1154 #undef rtinitflags
1155 
1156 /*
1157  * Return 1 if the address might be a local broadcast address.
1158  */
1159 int
1160 in_broadcast(struct in_addr in, struct ifnet *ifp)
1161 {
1162 	register struct ifaddr *ifa;
1163 	u_long t;
1164 
1165 	if (in.s_addr == INADDR_BROADCAST ||
1166 	    in.s_addr == INADDR_ANY)
1167 		return (1);
1168 	if ((ifp->if_flags & IFF_BROADCAST) == 0)
1169 		return (0);
1170 	t = ntohl(in.s_addr);
1171 	/*
1172 	 * Look through the list of addresses for a match
1173 	 * with a broadcast address.
1174 	 */
1175 #define ia ((struct in_ifaddr *)ifa)
1176 	TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
1177 		if (ifa->ifa_addr->sa_family == AF_INET &&
1178 		    (in.s_addr == ia->ia_broadaddr.sin_addr.s_addr ||
1179 		     /*
1180 		      * Check for old-style (host 0) broadcast, but
1181 		      * taking into account that RFC 3021 obsoletes it.
1182 		      */
1183 		    (ia->ia_subnetmask != IN_RFC3021_MASK &&
1184 		    t == ia->ia_subnet)) &&
1185 		     /*
1186 		      * Check for an all one subnetmask. These
1187 		      * only exist when an interface gets a secondary
1188 		      * address.
1189 		      */
1190 		    ia->ia_subnetmask != (u_long)0xffffffff)
1191 			    return (1);
1192 	return (0);
1193 #undef ia
1194 }
1195 
1196 /*
1197  * On interface removal, clean up IPv4 data structures hung off of the ifnet.
1198  */
1199 void
1200 in_ifdetach(struct ifnet *ifp)
1201 {
1202 
1203 	in_pcbpurgeif0(&V_ripcbinfo, ifp);
1204 	in_pcbpurgeif0(&V_udbinfo, ifp);
1205 	in_purgemaddrs(ifp);
1206 }
1207 
1208 /*
1209  * Delete all IPv4 multicast address records, and associated link-layer
1210  * multicast address records, associated with ifp.
1211  * XXX It looks like domifdetach runs AFTER the link layer cleanup.
1212  * XXX This should not race with ifma_protospec being set during
1213  * a new allocation, if it does, we have bigger problems.
1214  */
1215 static void
1216 in_purgemaddrs(struct ifnet *ifp)
1217 {
1218 	LIST_HEAD(,in_multi) purgeinms;
1219 	struct in_multi		*inm, *tinm;
1220 	struct ifmultiaddr	*ifma;
1221 
1222 	LIST_INIT(&purgeinms);
1223 	IN_MULTI_LOCK();
1224 
1225 	/*
1226 	 * Extract list of in_multi associated with the detaching ifp
1227 	 * which the PF_INET layer is about to release.
1228 	 * We need to do this as IF_ADDR_LOCK() may be re-acquired
1229 	 * by code further down.
1230 	 */
1231 	IF_ADDR_RLOCK(ifp);
1232 	TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
1233 		if (ifma->ifma_addr->sa_family != AF_INET ||
1234 		    ifma->ifma_protospec == NULL)
1235 			continue;
1236 #if 0
1237 		KASSERT(ifma->ifma_protospec != NULL,
1238 		    ("%s: ifma_protospec is NULL", __func__));
1239 #endif
1240 		inm = (struct in_multi *)ifma->ifma_protospec;
1241 		LIST_INSERT_HEAD(&purgeinms, inm, inm_link);
1242 	}
1243 	IF_ADDR_RUNLOCK(ifp);
1244 
1245 	LIST_FOREACH_SAFE(inm, &purgeinms, inm_link, tinm) {
1246 		LIST_REMOVE(inm, inm_link);
1247 		inm_release_locked(inm);
1248 	}
1249 	igmp_ifdetach(ifp);
1250 
1251 	IN_MULTI_UNLOCK();
1252 }
1253 
1254 struct in_llentry {
1255 	struct llentry		base;
1256 	struct sockaddr_in	l3_addr4;
1257 };
1258 
1259 /*
1260  * Deletes an address from the address table.
1261  * This function is called by the timer functions
1262  * such as arptimer() and nd6_llinfo_timer(), and
1263  * the caller does the locking.
1264  */
1265 static void
1266 in_lltable_free(struct lltable *llt, struct llentry *lle)
1267 {
1268 	LLE_WUNLOCK(lle);
1269 	LLE_LOCK_DESTROY(lle);
1270 	free(lle, M_LLTABLE);
1271 }
1272 
1273 static struct llentry *
1274 in_lltable_new(const struct sockaddr *l3addr, u_int flags)
1275 {
1276 	struct in_llentry *lle;
1277 
1278 	lle = malloc(sizeof(struct in_llentry), M_LLTABLE, M_NOWAIT | M_ZERO);
1279 	if (lle == NULL)		/* NB: caller generates msg */
1280 		return NULL;
1281 
1282 	/*
1283 	 * For IPv4 this will trigger "arpresolve" to generate
1284 	 * an ARP request.
1285 	 */
1286 	lle->base.la_expire = time_uptime; /* mark expired */
1287 	lle->l3_addr4 = *(const struct sockaddr_in *)l3addr;
1288 	lle->base.lle_refcnt = 1;
1289 	lle->base.lle_free = in_lltable_free;
1290 	LLE_LOCK_INIT(&lle->base);
1291 	callout_init_rw(&lle->base.la_timer, &lle->base.lle_lock,
1292 	    CALLOUT_RETURNUNLOCKED);
1293 
1294 	return (&lle->base);
1295 }
1296 
1297 #define IN_ARE_MASKED_ADDR_EQUAL(d, a, m)	(			\
1298 	    (((ntohl((d)->sin_addr.s_addr) ^ (a)->sin_addr.s_addr) & (m)->sin_addr.s_addr)) == 0 )
1299 
1300 static void
1301 in_lltable_prefix_free(struct lltable *llt, const struct sockaddr *prefix,
1302     const struct sockaddr *mask, u_int flags)
1303 {
1304 	const struct sockaddr_in *pfx = (const struct sockaddr_in *)prefix;
1305 	const struct sockaddr_in *msk = (const struct sockaddr_in *)mask;
1306 	struct llentry *lle, *next;
1307 	int i;
1308 	size_t pkts_dropped;
1309 
1310 	IF_AFDATA_WLOCK(llt->llt_ifp);
1311 	for (i = 0; i < LLTBL_HASHTBL_SIZE; i++) {
1312 		LIST_FOREACH_SAFE(lle, &llt->lle_head[i], lle_next, next) {
1313 			/*
1314 			 * (flags & LLE_STATIC) means deleting all entries
1315 			 * including static ARP entries.
1316 			 */
1317 			if (IN_ARE_MASKED_ADDR_EQUAL(satosin(L3_ADDR(lle)),
1318 			    pfx, msk) && ((flags & LLE_STATIC) ||
1319 			    !(lle->la_flags & LLE_STATIC))) {
1320 				LLE_WLOCK(lle);
1321 				if (callout_stop(&lle->la_timer))
1322 					LLE_REMREF(lle);
1323 				pkts_dropped = llentry_free(lle);
1324 				ARPSTAT_ADD(dropped, pkts_dropped);
1325 			}
1326 		}
1327 	}
1328 	IF_AFDATA_WUNLOCK(llt->llt_ifp);
1329 }
1330 
1331 
1332 static int
1333 in_lltable_rtcheck(struct ifnet *ifp, u_int flags, const struct sockaddr *l3addr)
1334 {
1335 	struct rtentry *rt;
1336 
1337 	KASSERT(l3addr->sa_family == AF_INET,
1338 	    ("sin_family %d", l3addr->sa_family));
1339 
1340 	/* XXX rtalloc1 should take a const param */
1341 	rt = rtalloc1(__DECONST(struct sockaddr *, l3addr), 0, 0);
1342 
1343 	if (rt == NULL)
1344 		return (EINVAL);
1345 
1346 	/*
1347 	 * If the gateway for an existing host route matches the target L3
1348 	 * address, which is a special route inserted by some implementation
1349 	 * such as MANET, and the interface is of the correct type, then
1350 	 * allow for ARP to proceed.
1351 	 */
1352 	if (rt->rt_flags & RTF_GATEWAY) {
1353 		if (!(rt->rt_flags & RTF_HOST) || !rt->rt_ifp ||
1354 		    rt->rt_ifp->if_type != IFT_ETHER ||
1355 		    (rt->rt_ifp->if_flags & (IFF_NOARP | IFF_STATICARP)) != 0 ||
1356 		    memcmp(rt->rt_gateway->sa_data, l3addr->sa_data,
1357 		    sizeof(in_addr_t)) != 0) {
1358 			RTFREE_LOCKED(rt);
1359 			return (EINVAL);
1360 		}
1361 	}
1362 
1363 	/*
1364 	 * Make sure that at least the destination address is covered
1365 	 * by the route. This is for handling the case where 2 or more
1366 	 * interfaces have the same prefix. An incoming packet arrives
1367 	 * on one interface and the corresponding outgoing packet leaves
1368 	 * another interface.
1369 	 */
1370 	if (!(rt->rt_flags & RTF_HOST) && rt->rt_ifp != ifp) {
1371 		const char *sa, *mask, *addr, *lim;
1372 		int len;
1373 
1374 		mask = (const char *)rt_mask(rt);
1375 		/*
1376 		 * Just being extra cautious to avoid some custom
1377 		 * code getting into trouble.
1378 		 */
1379 		if (mask == NULL) {
1380 			RTFREE_LOCKED(rt);
1381 			return (EINVAL);
1382 		}
1383 
1384 		sa = (const char *)rt_key(rt);
1385 		addr = (const char *)l3addr;
1386 		len = ((const struct sockaddr_in *)l3addr)->sin_len;
1387 		lim = addr + len;
1388 
1389 		for ( ; addr < lim; sa++, mask++, addr++) {
1390 			if ((*sa ^ *addr) & *mask) {
1391 #ifdef DIAGNOSTIC
1392 				log(LOG_INFO, "IPv4 address: \"%s\" is not on the network\n",
1393 				    inet_ntoa(((const struct sockaddr_in *)l3addr)->sin_addr));
1394 #endif
1395 				RTFREE_LOCKED(rt);
1396 				return (EINVAL);
1397 			}
1398 		}
1399 	}
1400 
1401 	RTFREE_LOCKED(rt);
1402 	return (0);
1403 }
1404 
1405 /*
1406  * Return NULL if not found or marked for deletion.
1407  * If found return lle read locked.
1408  */
1409 static struct llentry *
1410 in_lltable_lookup(struct lltable *llt, u_int flags, const struct sockaddr *l3addr)
1411 {
1412 	const struct sockaddr_in *sin = (const struct sockaddr_in *)l3addr;
1413 	struct ifnet *ifp = llt->llt_ifp;
1414 	struct llentry *lle;
1415 	struct llentries *lleh;
1416 	u_int hashkey;
1417 
1418 	IF_AFDATA_LOCK_ASSERT(ifp);
1419 	KASSERT(l3addr->sa_family == AF_INET,
1420 	    ("sin_family %d", l3addr->sa_family));
1421 
1422 	hashkey = sin->sin_addr.s_addr;
1423 	lleh = &llt->lle_head[LLATBL_HASH(hashkey, LLTBL_HASHMASK)];
1424 	LIST_FOREACH(lle, lleh, lle_next) {
1425 		struct sockaddr_in *sa2 = satosin(L3_ADDR(lle));
1426 		if (lle->la_flags & LLE_DELETED)
1427 			continue;
1428 		if (sa2->sin_addr.s_addr == sin->sin_addr.s_addr)
1429 			break;
1430 	}
1431 	if (lle == NULL) {
1432 #ifdef DIAGNOSTIC
1433 		if (flags & LLE_DELETE)
1434 			log(LOG_INFO, "interface address is missing from cache = %p  in delete\n", lle);
1435 #endif
1436 		if (!(flags & LLE_CREATE))
1437 			return (NULL);
1438 		/*
1439 		 * A route that covers the given address must have
1440 		 * been installed 1st because we are doing a resolution,
1441 		 * verify this.
1442 		 */
1443 		if (!(flags & LLE_IFADDR) &&
1444 		    in_lltable_rtcheck(ifp, flags, l3addr) != 0)
1445 			goto done;
1446 
1447 		lle = in_lltable_new(l3addr, flags);
1448 		if (lle == NULL) {
1449 			log(LOG_INFO, "lla_lookup: new lle malloc failed\n");
1450 			goto done;
1451 		}
1452 		lle->la_flags = flags & ~LLE_CREATE;
1453 		if ((flags & (LLE_CREATE | LLE_IFADDR)) == (LLE_CREATE | LLE_IFADDR)) {
1454 			bcopy(IF_LLADDR(ifp), &lle->ll_addr, ifp->if_addrlen);
1455 			lle->la_flags |= (LLE_VALID | LLE_STATIC);
1456 		}
1457 
1458 		lle->lle_tbl  = llt;
1459 		lle->lle_head = lleh;
1460 		lle->la_flags |= LLE_LINKED;
1461 		LIST_INSERT_HEAD(lleh, lle, lle_next);
1462 	} else if (flags & LLE_DELETE) {
1463 		if (!(lle->la_flags & LLE_IFADDR) || (flags & LLE_IFADDR)) {
1464 			LLE_WLOCK(lle);
1465 			lle->la_flags |= LLE_DELETED;
1466 			EVENTHANDLER_INVOKE(lle_event, lle, LLENTRY_DELETED);
1467 #ifdef DIAGNOSTIC
1468 			log(LOG_INFO, "ifaddr cache = %p is deleted\n", lle);
1469 #endif
1470 			if ((lle->la_flags &
1471 			    (LLE_STATIC | LLE_IFADDR)) == LLE_STATIC)
1472 				llentry_free(lle);
1473 			else
1474 				LLE_WUNLOCK(lle);
1475 		}
1476 		lle = (void *)-1;
1477 
1478 	}
1479 	if (LLE_IS_VALID(lle)) {
1480 		if (flags & LLE_EXCLUSIVE)
1481 			LLE_WLOCK(lle);
1482 		else
1483 			LLE_RLOCK(lle);
1484 	}
1485 done:
1486 	return (lle);
1487 }
1488 
1489 static int
1490 in_lltable_dump(struct lltable *llt, struct sysctl_req *wr)
1491 {
1492 #define	SIN(lle)	((struct sockaddr_in *) L3_ADDR(lle))
1493 	struct ifnet *ifp = llt->llt_ifp;
1494 	struct llentry *lle;
1495 	/* XXX stack use */
1496 	struct {
1497 		struct rt_msghdr	rtm;
1498 		struct sockaddr_in	sin;
1499 		struct sockaddr_dl	sdl;
1500 	} arpc;
1501 	int error, i;
1502 
1503 	LLTABLE_LOCK_ASSERT();
1504 
1505 	error = 0;
1506 	for (i = 0; i < LLTBL_HASHTBL_SIZE; i++) {
1507 		LIST_FOREACH(lle, &llt->lle_head[i], lle_next) {
1508 			struct sockaddr_dl *sdl;
1509 
1510 			/* skip deleted entries */
1511 			if ((lle->la_flags & LLE_DELETED) == LLE_DELETED)
1512 				continue;
1513 			/* Skip if jailed and not a valid IP of the prison. */
1514 			if (prison_if(wr->td->td_ucred, L3_ADDR(lle)) != 0)
1515 				continue;
1516 			/*
1517 			 * produce a msg made of:
1518 			 *  struct rt_msghdr;
1519 			 *  struct sockaddr_in; (IPv4)
1520 			 *  struct sockaddr_dl;
1521 			 */
1522 			bzero(&arpc, sizeof(arpc));
1523 			arpc.rtm.rtm_msglen = sizeof(arpc);
1524 			arpc.rtm.rtm_version = RTM_VERSION;
1525 			arpc.rtm.rtm_type = RTM_GET;
1526 			arpc.rtm.rtm_flags = RTF_UP;
1527 			arpc.rtm.rtm_addrs = RTA_DST | RTA_GATEWAY;
1528 			arpc.sin.sin_family = AF_INET;
1529 			arpc.sin.sin_len = sizeof(arpc.sin);
1530 			arpc.sin.sin_addr.s_addr = SIN(lle)->sin_addr.s_addr;
1531 
1532 			/* publish */
1533 			if (lle->la_flags & LLE_PUB)
1534 				arpc.rtm.rtm_flags |= RTF_ANNOUNCE;
1535 
1536 			sdl = &arpc.sdl;
1537 			sdl->sdl_family = AF_LINK;
1538 			sdl->sdl_len = sizeof(*sdl);
1539 			sdl->sdl_index = ifp->if_index;
1540 			sdl->sdl_type = ifp->if_type;
1541 			if ((lle->la_flags & LLE_VALID) == LLE_VALID) {
1542 				sdl->sdl_alen = ifp->if_addrlen;
1543 				bcopy(&lle->ll_addr, LLADDR(sdl), ifp->if_addrlen);
1544 			} else {
1545 				sdl->sdl_alen = 0;
1546 				bzero(LLADDR(sdl), ifp->if_addrlen);
1547 			}
1548 
1549 			arpc.rtm.rtm_rmx.rmx_expire =
1550 			    lle->la_flags & LLE_STATIC ? 0 : lle->la_expire;
1551 			arpc.rtm.rtm_flags |= (RTF_HOST | RTF_LLDATA);
1552 			if (lle->la_flags & LLE_STATIC)
1553 				arpc.rtm.rtm_flags |= RTF_STATIC;
1554 			arpc.rtm.rtm_index = ifp->if_index;
1555 			error = SYSCTL_OUT(wr, &arpc, sizeof(arpc));
1556 			if (error)
1557 				break;
1558 		}
1559 	}
1560 	return error;
1561 #undef SIN
1562 }
1563 
1564 void *
1565 in_domifattach(struct ifnet *ifp)
1566 {
1567 	struct in_ifinfo *ii;
1568 	struct lltable *llt;
1569 
1570 	ii = malloc(sizeof(struct in_ifinfo), M_IFADDR, M_WAITOK|M_ZERO);
1571 
1572 	llt = lltable_init(ifp, AF_INET);
1573 	if (llt != NULL) {
1574 		llt->llt_prefix_free = in_lltable_prefix_free;
1575 		llt->llt_lookup = in_lltable_lookup;
1576 		llt->llt_dump = in_lltable_dump;
1577 	}
1578 	ii->ii_llt = llt;
1579 
1580 	ii->ii_igmp = igmp_domifattach(ifp);
1581 
1582 	return ii;
1583 }
1584 
1585 void
1586 in_domifdetach(struct ifnet *ifp, void *aux)
1587 {
1588 	struct in_ifinfo *ii = (struct in_ifinfo *)aux;
1589 
1590 	igmp_domifdetach(ifp);
1591 	lltable_free(ii->ii_llt);
1592 	free(ii, M_IFADDR);
1593 }
1594