xref: /freebsd-14-stable/sys/netinet/in.c (revision 70831490663b7509203ff3f87beff1c8eda806a9)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1982, 1986, 1991, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  * Copyright (C) 2001 WIDE Project.  All rights reserved.
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  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  *	@(#)in.c	8.4 (Berkeley) 1/9/95
33  */
34 
35 #include <sys/cdefs.h>
36 #include "opt_inet.h"
37 
38 #define IN_HISTORICAL_NETS		/* include class masks */
39 
40 #include <sys/param.h>
41 #include <sys/eventhandler.h>
42 #include <sys/systm.h>
43 #include <sys/sockio.h>
44 #include <sys/malloc.h>
45 #include <sys/priv.h>
46 #include <sys/socket.h>
47 #include <sys/jail.h>
48 #include <sys/kernel.h>
49 #include <sys/lock.h>
50 #include <sys/proc.h>
51 #include <sys/sysctl.h>
52 #include <sys/syslog.h>
53 #include <sys/sx.h>
54 
55 #include <net/if.h>
56 #include <net/if_var.h>
57 #include <net/if_arp.h>
58 #include <net/if_dl.h>
59 #include <net/if_llatbl.h>
60 #include <net/if_private.h>
61 #include <net/if_types.h>
62 #include <net/route.h>
63 #include <net/route/nhop.h>
64 #include <net/route/route_ctl.h>
65 #include <net/vnet.h>
66 
67 #include <netinet/if_ether.h>
68 #include <netinet/in.h>
69 #include <netinet/in_fib.h>
70 #include <netinet/in_var.h>
71 #include <netinet/in_pcb.h>
72 #include <netinet/ip_var.h>
73 #include <netinet/ip_carp.h>
74 #include <netinet/igmp_var.h>
75 #include <netinet/udp.h>
76 #include <netinet/udp_var.h>
77 
78 #ifdef MAC
79 #include <security/mac/mac_framework.h>
80 #endif
81 
82 static int in_aifaddr_ioctl(u_long, caddr_t, struct ifnet *, struct ucred *);
83 static int in_difaddr_ioctl(u_long, caddr_t, struct ifnet *, struct ucred *);
84 static int in_gifaddr_ioctl(u_long, caddr_t, struct ifnet *, struct ucred *);
85 
86 static void	in_socktrim(struct sockaddr_in *);
87 static void	in_purgemaddrs(struct ifnet *);
88 
89 static bool	ia_need_loopback_route(const struct in_ifaddr *);
90 
91 VNET_DEFINE_STATIC(int, nosameprefix);
92 #define	V_nosameprefix			VNET(nosameprefix)
93 SYSCTL_INT(_net_inet_ip, OID_AUTO, no_same_prefix, CTLFLAG_VNET | CTLFLAG_RW,
94 	&VNET_NAME(nosameprefix), 0,
95 	"Refuse to create same prefixes on different interfaces");
96 
97 VNET_DEFINE_STATIC(bool, broadcast_lowest);
98 #define	V_broadcast_lowest		VNET(broadcast_lowest)
99 SYSCTL_BOOL(_net_inet_ip, OID_AUTO, broadcast_lowest, CTLFLAG_VNET | CTLFLAG_RW,
100 	&VNET_NAME(broadcast_lowest), 0,
101 	"Treat lowest address on a subnet (host 0) as broadcast");
102 
103 VNET_DEFINE(bool, ip_allow_net240) = false;
104 #define	V_ip_allow_net240		VNET(ip_allow_net240)
105 SYSCTL_BOOL(_net_inet_ip, OID_AUTO, allow_net240,
106 	CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip_allow_net240), 0,
107 	"Allow use of Experimental addresses, aka Class E (240/4)");
108 /* see https://datatracker.ietf.org/doc/draft-schoen-intarea-unicast-240 */
109 
110 VNET_DEFINE(bool, ip_allow_net0) = false;
111 SYSCTL_BOOL(_net_inet_ip, OID_AUTO, allow_net0,
112 	CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip_allow_net0), 0,
113 	"Allow use of addresses in network 0/8");
114 /* see https://datatracker.ietf.org/doc/draft-schoen-intarea-unicast-0 */
115 
116 VNET_DEFINE(uint32_t, in_loopback_mask) = IN_LOOPBACK_MASK_DFLT;
117 #define	V_in_loopback_mask	VNET(in_loopback_mask)
118 static int sysctl_loopback_prefixlen(SYSCTL_HANDLER_ARGS);
119 SYSCTL_PROC(_net_inet_ip, OID_AUTO, loopback_prefixlen,
120 	CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW,
121 	NULL, 0, sysctl_loopback_prefixlen, "I",
122 	"Prefix length of address space reserved for loopback");
123 /* see https://datatracker.ietf.org/doc/draft-schoen-intarea-unicast-127 */
124 
125 VNET_DECLARE(struct inpcbinfo, ripcbinfo);
126 #define	V_ripcbinfo			VNET(ripcbinfo)
127 
128 static struct sx in_control_sx;
129 SX_SYSINIT(in_control_sx, &in_control_sx, "in_control");
130 
131 /*
132  * Return true if an internet address is for a ``local'' host
133  * (one to which we have a connection).
134  */
135 bool
in_localaddr(struct in_addr in)136 in_localaddr(struct in_addr in)
137 {
138 	u_long i = ntohl(in.s_addr);
139 	struct in_ifaddr *ia;
140 
141 	NET_EPOCH_ASSERT();
142 
143 	CK_STAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
144 		if ((i & ia->ia_subnetmask) == ia->ia_subnet)
145 			return (true);
146 	}
147 
148 	return (false);
149 }
150 
151 /*
152  * Return true if an internet address is for the local host and configured
153  * on one of its interfaces.
154  */
155 bool
in_localip(struct in_addr in)156 in_localip(struct in_addr in)
157 {
158 	struct in_ifaddr *ia;
159 
160 	NET_EPOCH_ASSERT();
161 
162 	CK_LIST_FOREACH(ia, INADDR_HASH(in.s_addr), ia_hash)
163 		if (IA_SIN(ia)->sin_addr.s_addr == in.s_addr)
164 			return (true);
165 
166 	return (false);
167 }
168 
169 /*
170  * Like in_localip(), but FIB-aware and carp(4)-aware.
171  */
172 bool
in_localip_fib(struct in_addr in,uint16_t fib)173 in_localip_fib(struct in_addr in, uint16_t fib)
174 {
175 	struct in_ifaddr *ia;
176 
177 	NET_EPOCH_ASSERT();
178 
179 	CK_LIST_FOREACH(ia, INADDR_HASH(in.s_addr), ia_hash)
180 		if (IA_SIN(ia)->sin_addr.s_addr == in.s_addr &&
181 		    (ia->ia_ifa.ifa_carp == NULL ||
182 		    carp_master_p(&ia->ia_ifa)) &&
183 		    ia->ia_ifa.ifa_ifp->if_fib == fib)
184 			return (true);
185 
186 	return (false);
187 }
188 
189 /*
190  * Return true if an internet address is configured on an interface.
191  */
192 bool
in_ifhasaddr(struct ifnet * ifp,struct in_addr in)193 in_ifhasaddr(struct ifnet *ifp, struct in_addr in)
194 {
195 	struct ifaddr *ifa;
196 	struct in_ifaddr *ia;
197 
198 	NET_EPOCH_ASSERT();
199 
200 	CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
201 		if (ifa->ifa_addr->sa_family != AF_INET)
202 			continue;
203 		ia = (struct in_ifaddr *)ifa;
204 		if (ia->ia_addr.sin_addr.s_addr == in.s_addr)
205 			return (true);
206 	}
207 
208 	return (false);
209 }
210 
211 /*
212  * Return a reference to the interface address which is different to
213  * the supplied one but with same IP address value.
214  */
215 static struct in_ifaddr *
in_localip_more(struct in_ifaddr * original_ia)216 in_localip_more(struct in_ifaddr *original_ia)
217 {
218 	struct epoch_tracker et;
219 	in_addr_t original_addr = IA_SIN(original_ia)->sin_addr.s_addr;
220 	uint32_t original_fib = original_ia->ia_ifa.ifa_ifp->if_fib;
221 	struct in_ifaddr *ia;
222 
223 	NET_EPOCH_ENTER(et);
224 	CK_LIST_FOREACH(ia, INADDR_HASH(original_addr), ia_hash) {
225 		in_addr_t addr = IA_SIN(ia)->sin_addr.s_addr;
226 		uint32_t fib = ia->ia_ifa.ifa_ifp->if_fib;
227 		if (!V_rt_add_addr_allfibs && (original_fib != fib))
228 			continue;
229 		if ((original_ia != ia) && (original_addr == addr)) {
230 			ifa_ref(&ia->ia_ifa);
231 			NET_EPOCH_EXIT(et);
232 			return (ia);
233 		}
234 	}
235 	NET_EPOCH_EXIT(et);
236 
237 	return (NULL);
238 }
239 
240 /*
241  * Tries to find first IPv4 address in the provided fib.
242  * Prefers non-loopback addresses and return loopback IFF
243  * @loopback_ok is set.
244  *
245  * Returns ifa or NULL.
246  */
247 struct in_ifaddr *
in_findlocal(uint32_t fibnum,bool loopback_ok)248 in_findlocal(uint32_t fibnum, bool loopback_ok)
249 {
250 	struct in_ifaddr *ia = NULL, *ia_lo = NULL;
251 
252 	NET_EPOCH_ASSERT();
253 
254 	CK_STAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
255 		uint32_t ia_fib = ia->ia_ifa.ifa_ifp->if_fib;
256 		if (!V_rt_add_addr_allfibs && (fibnum != ia_fib))
257 			continue;
258 
259 		if (!IN_LOOPBACK(ntohl(IA_SIN(ia)->sin_addr.s_addr)))
260 			break;
261 		if (loopback_ok)
262 			ia_lo = ia;
263 	}
264 
265 	if (ia == NULL)
266 		ia = ia_lo;
267 
268 	return (ia);
269 }
270 
271 /*
272  * Determine whether an IP address is in a reserved set of addresses
273  * that may not be forwarded, or whether datagrams to that destination
274  * may be forwarded.
275  */
276 bool
in_canforward(struct in_addr in)277 in_canforward(struct in_addr in)
278 {
279 	u_long i = ntohl(in.s_addr);
280 
281 	if (IN_MULTICAST(i) || IN_LINKLOCAL(i) || IN_LOOPBACK(i) ||
282 	    in_nullhost(in))
283 		return (false);
284 	if (IN_EXPERIMENTAL(i) && !V_ip_allow_net240)
285 		return (false);
286 	if (IN_ZERONET(i) && !V_ip_allow_net0)
287 		return (false);
288 	return (true);
289 }
290 
291 /*
292  * Sysctl to manage prefix of reserved loopback network; translate
293  * to/from mask.  The mask is always contiguous high-order 1 bits
294  * followed by all 0 bits.
295  */
296 static int
sysctl_loopback_prefixlen(SYSCTL_HANDLER_ARGS)297 sysctl_loopback_prefixlen(SYSCTL_HANDLER_ARGS)
298 {
299 	int error, preflen;
300 
301 	/* ffs is 1-based; compensate. */
302 	preflen = 33 - ffs(V_in_loopback_mask);
303 	error = sysctl_handle_int(oidp, &preflen, 0, req);
304 	if (error || !req->newptr)
305 		return (error);
306 	if (preflen < 8 || preflen > 31)
307 		return (EINVAL);
308 	V_in_loopback_mask = 0xffffffff << (32 - preflen);
309 	return (0);
310 }
311 
312 /*
313  * Trim a mask in a sockaddr
314  */
315 static void
in_socktrim(struct sockaddr_in * ap)316 in_socktrim(struct sockaddr_in *ap)
317 {
318     char *cplim = (char *) &ap->sin_addr;
319     char *cp = (char *) (&ap->sin_addr + 1);
320 
321     ap->sin_len = 0;
322     while (--cp >= cplim)
323 	if (*cp) {
324 	    (ap)->sin_len = cp - (char *) (ap) + 1;
325 	    break;
326 	}
327 }
328 
329 /*
330  * Generic internet control operations (ioctl's).
331  */
332 int
in_control_ioctl(u_long cmd,void * data,struct ifnet * ifp,struct ucred * cred)333 in_control_ioctl(u_long cmd, void *data, struct ifnet *ifp,
334     struct ucred *cred)
335 {
336 	struct ifreq *ifr = (struct ifreq *)data;
337 	struct sockaddr_in *addr = (struct sockaddr_in *)&ifr->ifr_addr;
338 	struct epoch_tracker et;
339 	struct ifaddr *ifa;
340 	struct in_ifaddr *ia;
341 	int error;
342 
343 	if (ifp == NULL)
344 		return (EADDRNOTAVAIL);
345 
346 	/*
347 	 * Filter out 4 ioctls we implement directly.  Forward the rest
348 	 * to specific functions and ifp->if_ioctl().
349 	 */
350 	switch (cmd) {
351 	case SIOCGIFADDR:
352 	case SIOCGIFBRDADDR:
353 	case SIOCGIFDSTADDR:
354 	case SIOCGIFNETMASK:
355 		break;
356 	case SIOCGIFALIAS:
357 		sx_xlock(&in_control_sx);
358 		error = in_gifaddr_ioctl(cmd, data, ifp, cred);
359 		sx_xunlock(&in_control_sx);
360 		return (error);
361 	case SIOCDIFADDR:
362 		sx_xlock(&in_control_sx);
363 		error = in_difaddr_ioctl(cmd, data, ifp, cred);
364 		sx_xunlock(&in_control_sx);
365 		return (error);
366 	case OSIOCAIFADDR:	/* 9.x compat */
367 	case SIOCAIFADDR:
368 		sx_xlock(&in_control_sx);
369 		error = in_aifaddr_ioctl(cmd, data, ifp, cred);
370 		sx_xunlock(&in_control_sx);
371 		return (error);
372 	case SIOCSIFADDR:
373 	case SIOCSIFBRDADDR:
374 	case SIOCSIFDSTADDR:
375 	case SIOCSIFNETMASK:
376 		/* We no longer support that old commands. */
377 		return (EINVAL);
378 	default:
379 		if (ifp->if_ioctl == NULL)
380 			return (EOPNOTSUPP);
381 		return ((*ifp->if_ioctl)(ifp, cmd, data));
382 	}
383 
384 	if (addr->sin_addr.s_addr != INADDR_ANY &&
385 	    prison_check_ip4(cred, &addr->sin_addr) != 0)
386 		return (EADDRNOTAVAIL);
387 
388 	/*
389 	 * Find address for this interface, if it exists.  If an
390 	 * address was specified, find that one instead of the
391 	 * first one on the interface, if possible.
392 	 */
393 	NET_EPOCH_ENTER(et);
394 	CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
395 		if (ifa->ifa_addr->sa_family != AF_INET)
396 			continue;
397 		ia = (struct in_ifaddr *)ifa;
398 		if (ia->ia_addr.sin_addr.s_addr == addr->sin_addr.s_addr)
399 			break;
400 	}
401 	if (ifa == NULL)
402 		CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
403 			if (ifa->ifa_addr->sa_family == AF_INET) {
404 				ia = (struct in_ifaddr *)ifa;
405 				if (prison_check_ip4(cred,
406 				    &ia->ia_addr.sin_addr) == 0)
407 					break;
408 			}
409 
410 	if (ifa == NULL) {
411 		NET_EPOCH_EXIT(et);
412 		return (EADDRNOTAVAIL);
413 	}
414 
415 	error = 0;
416 	switch (cmd) {
417 	case SIOCGIFADDR:
418 		*addr = ia->ia_addr;
419 		break;
420 
421 	case SIOCGIFBRDADDR:
422 		if ((ifp->if_flags & IFF_BROADCAST) == 0) {
423 			error = EINVAL;
424 			break;
425 		}
426 		*addr = ia->ia_broadaddr;
427 		break;
428 
429 	case SIOCGIFDSTADDR:
430 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0) {
431 			error = EINVAL;
432 			break;
433 		}
434 		*addr = ia->ia_dstaddr;
435 		break;
436 
437 	case SIOCGIFNETMASK:
438 		*addr = ia->ia_sockmask;
439 		break;
440 	}
441 
442 	NET_EPOCH_EXIT(et);
443 
444 	return (error);
445 }
446 
447 int
in_control(struct socket * so,u_long cmd,void * data,struct ifnet * ifp,struct thread * td)448 in_control(struct socket *so, u_long cmd, void *data, struct ifnet *ifp,
449     struct thread *td)
450 {
451 	return (in_control_ioctl(cmd, data, ifp, td ? td->td_ucred : NULL));
452 }
453 
454 static int
in_aifaddr_ioctl(u_long cmd,caddr_t data,struct ifnet * ifp,struct ucred * cred)455 in_aifaddr_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp, struct ucred *cred)
456 {
457 	const struct in_aliasreq *ifra = (struct in_aliasreq *)data;
458 	const struct sockaddr_in *addr = &ifra->ifra_addr;
459 	const struct sockaddr_in *broadaddr = &ifra->ifra_broadaddr;
460 	const struct sockaddr_in *mask = &ifra->ifra_mask;
461 	const struct sockaddr_in *dstaddr = &ifra->ifra_dstaddr;
462 	const int vhid = (cmd == SIOCAIFADDR) ? ifra->ifra_vhid : 0;
463 	struct epoch_tracker et;
464 	struct ifaddr *ifa;
465 	struct in_ifaddr *ia;
466 	bool iaIsFirst;
467 	int error = 0;
468 
469 	error = priv_check_cred(cred, PRIV_NET_ADDIFADDR);
470 	if (error)
471 		return (error);
472 
473 	/*
474 	 * ifra_addr must be present and be of INET family.
475 	 * ifra_broadaddr/ifra_dstaddr and ifra_mask are optional.
476 	 */
477 	if (addr->sin_len != sizeof(struct sockaddr_in) ||
478 	    addr->sin_family != AF_INET)
479 		return (EINVAL);
480 	if (broadaddr->sin_len != 0 &&
481 	    (broadaddr->sin_len != sizeof(struct sockaddr_in) ||
482 	    broadaddr->sin_family != AF_INET))
483 		return (EINVAL);
484 	if (mask->sin_len != 0 &&
485 	    (mask->sin_len != sizeof(struct sockaddr_in) ||
486 	    mask->sin_family != AF_INET))
487 		return (EINVAL);
488 	if ((ifp->if_flags & IFF_POINTOPOINT) &&
489 	    (dstaddr->sin_len != sizeof(struct sockaddr_in) ||
490 	     dstaddr->sin_addr.s_addr == INADDR_ANY))
491 		return (EDESTADDRREQ);
492 	if (vhid != 0 && carp_attach_p == NULL)
493 		return (EPROTONOSUPPORT);
494 
495 #ifdef MAC
496 	/* Check if a MAC policy disallows setting the IPv4 address. */
497 	error = mac_inet_check_add_addr(cred, &addr->sin_addr, ifp);
498 	if (error != 0)
499 		return (error);
500 #endif
501 
502 	/*
503 	 * See whether address already exist.
504 	 */
505 	iaIsFirst = true;
506 	ia = NULL;
507 	NET_EPOCH_ENTER(et);
508 	CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
509 		struct in_ifaddr *it;
510 
511 		if (ifa->ifa_addr->sa_family != AF_INET)
512 			continue;
513 
514 		it = (struct in_ifaddr *)ifa;
515 		if (it->ia_addr.sin_addr.s_addr == addr->sin_addr.s_addr &&
516 		    prison_check_ip4(cred, &addr->sin_addr) == 0)
517 			ia = it;
518 		else
519 			iaIsFirst = false;
520 	}
521 	NET_EPOCH_EXIT(et);
522 
523 	if (ia != NULL)
524 		(void )in_difaddr_ioctl(cmd, data, ifp, cred);
525 
526 	ifa = ifa_alloc(sizeof(struct in_ifaddr), M_WAITOK);
527 	ia = (struct in_ifaddr *)ifa;
528 	ifa->ifa_addr = (struct sockaddr *)&ia->ia_addr;
529 	ifa->ifa_dstaddr = (struct sockaddr *)&ia->ia_dstaddr;
530 	ifa->ifa_netmask = (struct sockaddr *)&ia->ia_sockmask;
531 	callout_init_rw(&ia->ia_garp_timer, &ifp->if_addr_lock,
532 	    CALLOUT_RETURNUNLOCKED);
533 
534 	ia->ia_ifp = ifp;
535 	ia->ia_addr = *addr;
536 	if (mask->sin_len != 0) {
537 		ia->ia_sockmask = *mask;
538 		ia->ia_subnetmask = ntohl(ia->ia_sockmask.sin_addr.s_addr);
539 	} else {
540 		in_addr_t i = ntohl(addr->sin_addr.s_addr);
541 
542 		/*
543 	 	 * If netmask isn't supplied, use historical default.
544 		 * This is deprecated for interfaces other than loopback
545 		 * or point-to-point; warn in other cases.  In the future
546 		 * we should return an error rather than warning.
547 	 	 */
548 		if ((ifp->if_flags & (IFF_POINTOPOINT | IFF_LOOPBACK)) == 0)
549 			printf("%s: set address: WARNING: network mask "
550 			     "should be specified; using historical default\n",
551 			     ifp->if_xname);
552 		if (IN_CLASSA(i))
553 			ia->ia_subnetmask = IN_CLASSA_NET;
554 		else if (IN_CLASSB(i))
555 			ia->ia_subnetmask = IN_CLASSB_NET;
556 		else
557 			ia->ia_subnetmask = IN_CLASSC_NET;
558 		ia->ia_sockmask.sin_addr.s_addr = htonl(ia->ia_subnetmask);
559 	}
560 	ia->ia_subnet = ntohl(addr->sin_addr.s_addr) & ia->ia_subnetmask;
561 	in_socktrim(&ia->ia_sockmask);
562 
563 	if (ifp->if_flags & IFF_BROADCAST) {
564 		if (broadaddr->sin_len != 0) {
565 			ia->ia_broadaddr = *broadaddr;
566 		} else if (ia->ia_subnetmask == IN_RFC3021_MASK) {
567 			ia->ia_broadaddr.sin_addr.s_addr = INADDR_BROADCAST;
568 			ia->ia_broadaddr.sin_len = sizeof(struct sockaddr_in);
569 			ia->ia_broadaddr.sin_family = AF_INET;
570 		} else {
571 			ia->ia_broadaddr.sin_addr.s_addr =
572 			    htonl(ia->ia_subnet | ~ia->ia_subnetmask);
573 			ia->ia_broadaddr.sin_len = sizeof(struct sockaddr_in);
574 			ia->ia_broadaddr.sin_family = AF_INET;
575 		}
576 	}
577 
578 	if (ifp->if_flags & IFF_POINTOPOINT)
579 		ia->ia_dstaddr = *dstaddr;
580 
581 	if (vhid != 0) {
582 		error = (*carp_attach_p)(&ia->ia_ifa, vhid);
583 		if (error)
584 			return (error);
585 	}
586 
587 	/* if_addrhead is already referenced by ifa_alloc() */
588 	IF_ADDR_WLOCK(ifp);
589 	CK_STAILQ_INSERT_TAIL(&ifp->if_addrhead, ifa, ifa_link);
590 	IF_ADDR_WUNLOCK(ifp);
591 
592 	ifa_ref(ifa);			/* in_ifaddrhead */
593 	sx_assert(&in_control_sx, SA_XLOCKED);
594 	CK_STAILQ_INSERT_TAIL(&V_in_ifaddrhead, ia, ia_link);
595 	CK_LIST_INSERT_HEAD(INADDR_HASH(ia->ia_addr.sin_addr.s_addr), ia,
596 	    ia_hash);
597 
598 	/*
599 	 * Give the interface a chance to initialize
600 	 * if this is its first address,
601 	 * and to validate the address if necessary.
602 	 */
603 	if (ifp->if_ioctl != NULL) {
604 		error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia);
605 		if (error)
606 			goto fail1;
607 	}
608 
609 	/*
610 	 * Add route for the network.
611 	 */
612 	if (vhid == 0) {
613 		error = in_addprefix(ia);
614 		if (error)
615 			goto fail1;
616 	}
617 
618 	/*
619 	 * Add a loopback route to self.
620 	 */
621 	if (vhid == 0 && ia_need_loopback_route(ia)) {
622 		struct in_ifaddr *eia;
623 
624 		eia = in_localip_more(ia);
625 
626 		if (eia == NULL) {
627 			error = ifa_add_loopback_route((struct ifaddr *)ia,
628 			    (struct sockaddr *)&ia->ia_addr);
629 			if (error)
630 				goto fail2;
631 		} else
632 			ifa_free(&eia->ia_ifa);
633 	}
634 
635 	if (iaIsFirst && (ifp->if_flags & IFF_MULTICAST)) {
636 		struct in_addr allhosts_addr;
637 		struct in_ifinfo *ii;
638 
639 		ii = ((struct in_ifinfo *)ifp->if_afdata[AF_INET]);
640 		allhosts_addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);
641 
642 		error = in_joingroup(ifp, &allhosts_addr, NULL,
643 			&ii->ii_allhosts);
644 	}
645 
646 	/*
647 	 * Note: we don't need extra reference for ifa, since we called
648 	 * with sx lock held, and ifaddr can not be deleted in concurrent
649 	 * thread.
650 	 */
651 	EVENTHANDLER_INVOKE(ifaddr_event_ext, ifp, ifa, IFADDR_EVENT_ADD);
652 
653 	return (error);
654 
655 fail2:
656 	if (vhid == 0)
657 		(void )in_scrubprefix(ia, LLE_STATIC);
658 
659 fail1:
660 	if (ia->ia_ifa.ifa_carp)
661 		(*carp_detach_p)(&ia->ia_ifa, false);
662 
663 	IF_ADDR_WLOCK(ifp);
664 	CK_STAILQ_REMOVE(&ifp->if_addrhead, &ia->ia_ifa, ifaddr, ifa_link);
665 	IF_ADDR_WUNLOCK(ifp);
666 	ifa_free(&ia->ia_ifa);		/* if_addrhead */
667 
668 	sx_assert(&in_control_sx, SA_XLOCKED);
669 	CK_STAILQ_REMOVE(&V_in_ifaddrhead, ia, in_ifaddr, ia_link);
670 	CK_LIST_REMOVE(ia, ia_hash);
671 	ifa_free(&ia->ia_ifa);		/* in_ifaddrhead */
672 
673 	return (error);
674 }
675 
676 static int
in_difaddr_ioctl(u_long cmd,caddr_t data,struct ifnet * ifp,struct ucred * cred)677 in_difaddr_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp, struct ucred *cred)
678 {
679 	const struct ifreq *ifr = (struct ifreq *)data;
680 	const struct sockaddr_in *addr = (const struct sockaddr_in *)
681 	    &ifr->ifr_addr;
682 	struct ifaddr *ifa;
683 	struct in_ifaddr *ia;
684 	bool deleteAny, iaIsLast;
685 	int error;
686 
687 	if (cred != NULL) {
688 		error = priv_check_cred(cred, PRIV_NET_DELIFADDR);
689 		if (error)
690 			return (error);
691 	}
692 
693 	if (addr->sin_len != sizeof(struct sockaddr_in) ||
694 	    addr->sin_family != AF_INET)
695 		deleteAny = true;
696 	else
697 		deleteAny = false;
698 
699 	iaIsLast = true;
700 	ia = NULL;
701 	IF_ADDR_WLOCK(ifp);
702 	CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
703 		struct in_ifaddr *it;
704 
705 		if (ifa->ifa_addr->sa_family != AF_INET)
706 			continue;
707 
708 		it = (struct in_ifaddr *)ifa;
709 		if (deleteAny && ia == NULL && (cred == NULL ||
710 		    prison_check_ip4(cred, &it->ia_addr.sin_addr) == 0))
711 			ia = it;
712 
713 		if (it->ia_addr.sin_addr.s_addr == addr->sin_addr.s_addr &&
714 		    (cred == NULL || prison_check_ip4(cred,
715 		    &addr->sin_addr) == 0))
716 			ia = it;
717 
718 		if (it != ia)
719 			iaIsLast = false;
720 	}
721 
722 	if (ia == NULL) {
723 		IF_ADDR_WUNLOCK(ifp);
724 		return (EADDRNOTAVAIL);
725 	}
726 
727 	CK_STAILQ_REMOVE(&ifp->if_addrhead, &ia->ia_ifa, ifaddr, ifa_link);
728 	IF_ADDR_WUNLOCK(ifp);
729 	ifa_free(&ia->ia_ifa);		/* if_addrhead */
730 
731 	sx_assert(&in_control_sx, SA_XLOCKED);
732 	CK_STAILQ_REMOVE(&V_in_ifaddrhead, ia, in_ifaddr, ia_link);
733 	CK_LIST_REMOVE(ia, ia_hash);
734 
735 	/*
736 	 * in_scrubprefix() kills the interface route.
737 	 */
738 	in_scrubprefix(ia, LLE_STATIC);
739 
740 	/*
741 	 * in_ifadown gets rid of all the rest of
742 	 * the routes.  This is not quite the right
743 	 * thing to do, but at least if we are running
744 	 * a routing process they will come back.
745 	 */
746 	in_ifadown(&ia->ia_ifa, 1);
747 
748 	if (ia->ia_ifa.ifa_carp)
749 		(*carp_detach_p)(&ia->ia_ifa, cmd == SIOCAIFADDR);
750 
751 	/*
752 	 * If this is the last IPv4 address configured on this
753 	 * interface, leave the all-hosts group.
754 	 * No state-change report need be transmitted.
755 	 */
756 	if (iaIsLast && (ifp->if_flags & IFF_MULTICAST)) {
757 		struct in_ifinfo *ii;
758 
759 		ii = ((struct in_ifinfo *)ifp->if_afdata[AF_INET]);
760 		if (ii->ii_allhosts) {
761 			(void)in_leavegroup(ii->ii_allhosts, NULL);
762 			ii->ii_allhosts = NULL;
763 		}
764 	}
765 
766 	IF_ADDR_WLOCK(ifp);
767 	if (callout_stop(&ia->ia_garp_timer) == 1) {
768 		ifa_free(&ia->ia_ifa);
769 	}
770 	IF_ADDR_WUNLOCK(ifp);
771 
772 	EVENTHANDLER_INVOKE(ifaddr_event_ext, ifp, &ia->ia_ifa,
773 	    IFADDR_EVENT_DEL);
774 	ifa_free(&ia->ia_ifa);		/* in_ifaddrhead */
775 
776 	return (0);
777 }
778 
779 static int
in_gifaddr_ioctl(u_long cmd,caddr_t data,struct ifnet * ifp,struct ucred * cred)780 in_gifaddr_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp, struct ucred *cred)
781 {
782 	struct in_aliasreq *ifra = (struct in_aliasreq *)data;
783 	const struct sockaddr_in *addr = &ifra->ifra_addr;
784 	struct epoch_tracker et;
785 	struct ifaddr *ifa;
786 	struct in_ifaddr *ia;
787 
788 	/*
789 	 * ifra_addr must be present and be of INET family.
790 	 */
791 	if (addr->sin_len != sizeof(struct sockaddr_in) ||
792 	    addr->sin_family != AF_INET)
793 		return (EINVAL);
794 
795 	/*
796 	 * See whether address exist.
797 	 */
798 	ia = NULL;
799 	NET_EPOCH_ENTER(et);
800 	CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
801 		struct in_ifaddr *it;
802 
803 		if (ifa->ifa_addr->sa_family != AF_INET)
804 			continue;
805 
806 		it = (struct in_ifaddr *)ifa;
807 		if (it->ia_addr.sin_addr.s_addr == addr->sin_addr.s_addr &&
808 		    prison_check_ip4(cred, &addr->sin_addr) == 0) {
809 			ia = it;
810 			break;
811 		}
812 	}
813 	if (ia == NULL) {
814 		NET_EPOCH_EXIT(et);
815 		return (EADDRNOTAVAIL);
816 	}
817 
818 	ifra->ifra_mask = ia->ia_sockmask;
819 	if ((ifp->if_flags & IFF_POINTOPOINT) &&
820 	    ia->ia_dstaddr.sin_family == AF_INET)
821 		ifra->ifra_dstaddr = ia->ia_dstaddr;
822 	else if ((ifp->if_flags & IFF_BROADCAST) &&
823 	    ia->ia_broadaddr.sin_family == AF_INET)
824 		ifra->ifra_broadaddr = ia->ia_broadaddr;
825 	else
826 		memset(&ifra->ifra_broadaddr, 0,
827 		    sizeof(ifra->ifra_broadaddr));
828 
829 	NET_EPOCH_EXIT(et);
830 	return (0);
831 }
832 
833 static int
in_match_ifaddr(const struct rtentry * rt,const struct nhop_object * nh,void * arg)834 in_match_ifaddr(const struct rtentry *rt, const struct nhop_object *nh, void *arg)
835 {
836 
837 	if (nh->nh_ifa == (struct ifaddr *)arg)
838 		return (1);
839 
840 	return (0);
841 }
842 
843 static int
in_handle_prefix_route(uint32_t fibnum,int cmd,struct sockaddr_in * dst,struct sockaddr_in * netmask,struct ifaddr * ifa,struct ifnet * ifp)844 in_handle_prefix_route(uint32_t fibnum, int cmd,
845     struct sockaddr_in *dst, struct sockaddr_in *netmask, struct ifaddr *ifa,
846     struct ifnet *ifp)
847 {
848 
849 	NET_EPOCH_ASSERT();
850 
851 	/* Prepare gateway */
852 	struct sockaddr_dl_short sdl = {
853 		.sdl_family = AF_LINK,
854 		.sdl_len = sizeof(struct sockaddr_dl_short),
855 		.sdl_type = ifa->ifa_ifp->if_type,
856 		.sdl_index = ifa->ifa_ifp->if_index,
857 	};
858 
859 	struct rt_addrinfo info = {
860 		.rti_ifa = ifa,
861 		.rti_ifp = ifp,
862 		.rti_flags = RTF_PINNED | ((netmask != NULL) ? 0 : RTF_HOST),
863 		.rti_info = {
864 			[RTAX_DST] = (struct sockaddr *)dst,
865 			[RTAX_NETMASK] = (struct sockaddr *)netmask,
866 			[RTAX_GATEWAY] = (struct sockaddr *)&sdl,
867 		},
868 		/* Ensure we delete the prefix IFF prefix ifa matches */
869 		.rti_filter = in_match_ifaddr,
870 		.rti_filterdata = ifa,
871 	};
872 
873 	return (rib_handle_ifaddr_info(fibnum, cmd, &info));
874 }
875 
876 /*
877  * Routing table interaction with interface addresses.
878  *
879  * In general, two types of routes needs to be installed:
880  * a) "interface" or "prefix" route, telling user that the addresses
881  *   behind the ifa prefix are reached directly.
882  * b) "loopback" route installed for the ifa address, telling user that
883  *   the address belongs to local system.
884  *
885  * Handling for (a) and (b) differs in multi-fib aspects, hence they
886  *  are implemented in different functions below.
887  *
888  * The cases above may intersect - /32 interface aliases results in
889  *  the same prefix produced by (a) and (b). This blurs the definition
890  *  of the "loopback" route and complicate interactions. The interaction
891  *  table is defined below. The case numbers are used in the multiple
892  *  functions below to refer to the particular test case.
893  *
894  * There can be multiple options:
895  * 1) Adding address with prefix on non-p2p/non-loopback interface.
896  *  Example: 192.0.2.1/24. Action:
897  *  * add "prefix" route towards 192.0.2.0/24 via @ia interface,
898  *    using @ia as an address source.
899  *  * add "loopback" route towards 192.0.2.1 via V_loif, saving
900  *   @ia ifp in the gateway and using @ia as an address source.
901  *
902  * 2) Adding address with /32 mask to non-p2p/non-loopback interface.
903  *  Example: 192.0.2.2/32. Action:
904  *  * add "prefix" host route via V_loif, using @ia as an address source.
905  *
906  * 3) Adding address with or without prefix to p2p interface.
907  *  Example: 10.0.0.1/24->10.0.0.2. Action:
908  *  * add "prefix" host route towards 10.0.0.2 via this interface, using @ia
909  *    as an address source. Note: no sense in installing full /24 as the interface
910  *    is point-to-point.
911  *  * add "loopback" route towards 10.0.9.1 via V_loif, saving
912  *   @ia ifp in the gateway and using @ia as an address source.
913  *
914  * 4) Adding address with or without prefix to loopback interface.
915  *  Example: 192.0.2.1/24. Action:
916  *  * add "prefix" host route via @ia interface, using @ia as an address source.
917  *    Note: Skip installing /24 prefix as it would introduce TTL loop
918  *    for the traffic destined to these addresses.
919  */
920 
921 /*
922  * Checks if @ia needs to install loopback route to @ia address via
923  *  ifa_maintain_loopback_route().
924  *
925  * Return true on success.
926  */
927 static bool
ia_need_loopback_route(const struct in_ifaddr * ia)928 ia_need_loopback_route(const struct in_ifaddr *ia)
929 {
930 	struct ifnet *ifp = ia->ia_ifp;
931 
932 	/* Case 4: Skip loopback interfaces */
933 	if ((ifp->if_flags & IFF_LOOPBACK) ||
934 	    (ia->ia_addr.sin_addr.s_addr == INADDR_ANY))
935 		return (false);
936 
937 	/* Clash avoidance: Skip p2p interfaces with both addresses are equal */
938 	if ((ifp->if_flags & IFF_POINTOPOINT) &&
939 	    ia->ia_dstaddr.sin_addr.s_addr == ia->ia_addr.sin_addr.s_addr)
940 		return (false);
941 
942 	/* Case 2: skip /32 prefixes */
943 	if (!(ifp->if_flags & IFF_POINTOPOINT) &&
944 	    (ia->ia_sockmask.sin_addr.s_addr == INADDR_BROADCAST))
945 		return (false);
946 
947 	return (true);
948 }
949 
950 /*
951  * Calculate "prefix" route corresponding to @ia.
952  */
953 static void
ia_getrtprefix(const struct in_ifaddr * ia,struct in_addr * prefix,struct in_addr * mask)954 ia_getrtprefix(const struct in_ifaddr *ia, struct in_addr *prefix, struct in_addr *mask)
955 {
956 
957 	if (ia->ia_ifp->if_flags & IFF_POINTOPOINT) {
958 		/* Case 3: return host route for dstaddr */
959 		*prefix = ia->ia_dstaddr.sin_addr;
960 		mask->s_addr = INADDR_BROADCAST;
961 	} else if (ia->ia_ifp->if_flags & IFF_LOOPBACK) {
962 		/* Case 4: return host route for ifaddr */
963 		*prefix = ia->ia_addr.sin_addr;
964 		mask->s_addr = INADDR_BROADCAST;
965 	} else {
966 		/* Cases 1,2: return actual ia prefix */
967 		*prefix = ia->ia_addr.sin_addr;
968 		*mask = ia->ia_sockmask.sin_addr;
969 		prefix->s_addr &= mask->s_addr;
970 	}
971 }
972 
973 /*
974  * Adds or delete interface "prefix" route corresponding to @ifa.
975  *  Returns 0 on success or errno.
976  */
977 static int
in_handle_ifaddr_route(int cmd,struct in_ifaddr * ia)978 in_handle_ifaddr_route(int cmd, struct in_ifaddr *ia)
979 {
980 	struct ifaddr *ifa = &ia->ia_ifa;
981 	struct in_addr daddr, maddr;
982 	struct sockaddr_in *pmask;
983 	struct epoch_tracker et;
984 	int error;
985 
986 	ia_getrtprefix(ia, &daddr, &maddr);
987 
988 	struct sockaddr_in mask = {
989 		.sin_family = AF_INET,
990 		.sin_len = sizeof(struct sockaddr_in),
991 		.sin_addr = maddr,
992 	};
993 
994 	pmask = (maddr.s_addr != INADDR_BROADCAST) ? &mask : NULL;
995 
996 	struct sockaddr_in dst = {
997 		.sin_family = AF_INET,
998 		.sin_len = sizeof(struct sockaddr_in),
999 		.sin_addr.s_addr = daddr.s_addr & maddr.s_addr,
1000 	};
1001 
1002 	struct ifnet *ifp = ia->ia_ifp;
1003 
1004 	if ((maddr.s_addr == INADDR_BROADCAST) &&
1005 	    (!(ia->ia_ifp->if_flags & (IFF_POINTOPOINT|IFF_LOOPBACK)))) {
1006 		/* Case 2: host route on broadcast interface */
1007 		ifp = V_loif;
1008 	}
1009 
1010 	uint32_t fibnum = ifa->ifa_ifp->if_fib;
1011 	NET_EPOCH_ENTER(et);
1012 	error = in_handle_prefix_route(fibnum, cmd, &dst, pmask, ifa, ifp);
1013 	NET_EPOCH_EXIT(et);
1014 
1015 	return (error);
1016 }
1017 
1018 /*
1019  * Check if we have a route for the given prefix already.
1020  */
1021 static bool
in_hasrtprefix(struct in_ifaddr * target)1022 in_hasrtprefix(struct in_ifaddr *target)
1023 {
1024 	struct epoch_tracker et;
1025 	struct in_ifaddr *ia;
1026 	struct in_addr prefix, mask, p, m;
1027 	bool result = false;
1028 
1029 	ia_getrtprefix(target, &prefix, &mask);
1030 
1031 	/* Look for an existing address with the same prefix, mask, and fib */
1032 	NET_EPOCH_ENTER(et);
1033 	CK_STAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
1034 		ia_getrtprefix(ia, &p, &m);
1035 
1036 		if (prefix.s_addr != p.s_addr ||
1037 		    mask.s_addr != m.s_addr)
1038 			continue;
1039 
1040 		if (target->ia_ifp->if_fib != ia->ia_ifp->if_fib)
1041 			continue;
1042 
1043 		/*
1044 		 * If we got a matching prefix route inserted by other
1045 		 * interface address, we are done here.
1046 		 */
1047 		if (ia->ia_flags & IFA_ROUTE) {
1048 			result = true;
1049 			break;
1050 		}
1051 	}
1052 	NET_EPOCH_EXIT(et);
1053 
1054 	return (result);
1055 }
1056 
1057 int
in_addprefix(struct in_ifaddr * target)1058 in_addprefix(struct in_ifaddr *target)
1059 {
1060 	int error;
1061 
1062 	if (in_hasrtprefix(target)) {
1063 		if (V_nosameprefix)
1064 			return (EEXIST);
1065 		else {
1066 			rt_addrmsg(RTM_ADD, &target->ia_ifa,
1067 			    target->ia_ifp->if_fib);
1068 			return (0);
1069 		}
1070 	}
1071 
1072 	/*
1073 	 * No-one seem to have this prefix route, so we try to insert it.
1074 	 */
1075 	rt_addrmsg(RTM_ADD, &target->ia_ifa, target->ia_ifp->if_fib);
1076 	error = in_handle_ifaddr_route(RTM_ADD, target);
1077 	if (!error)
1078 		target->ia_flags |= IFA_ROUTE;
1079 	return (error);
1080 }
1081 
1082 /*
1083  * Removes either all lle entries for given @ia, or lle
1084  * corresponding to @ia address.
1085  */
1086 static void
in_scrubprefixlle(struct in_ifaddr * ia,int all,u_int flags)1087 in_scrubprefixlle(struct in_ifaddr *ia, int all, u_int flags)
1088 {
1089 	struct sockaddr_in addr, mask;
1090 	struct sockaddr *saddr, *smask;
1091 	struct ifnet *ifp;
1092 
1093 	saddr = (struct sockaddr *)&addr;
1094 	bzero(&addr, sizeof(addr));
1095 	addr.sin_len = sizeof(addr);
1096 	addr.sin_family = AF_INET;
1097 	smask = (struct sockaddr *)&mask;
1098 	bzero(&mask, sizeof(mask));
1099 	mask.sin_len = sizeof(mask);
1100 	mask.sin_family = AF_INET;
1101 	mask.sin_addr.s_addr = ia->ia_subnetmask;
1102 	ifp = ia->ia_ifp;
1103 
1104 	if (all) {
1105 		/*
1106 		 * Remove all L2 entries matching given prefix.
1107 		 * Convert address to host representation to avoid
1108 		 * doing this on every callback. ia_subnetmask is already
1109 		 * stored in host representation.
1110 		 */
1111 		addr.sin_addr.s_addr = ntohl(ia->ia_addr.sin_addr.s_addr);
1112 		lltable_prefix_free(AF_INET, saddr, smask, flags);
1113 	} else {
1114 		/* Remove interface address only */
1115 		addr.sin_addr.s_addr = ia->ia_addr.sin_addr.s_addr;
1116 		lltable_delete_addr(LLTABLE(ifp), LLE_IFADDR, saddr);
1117 	}
1118 }
1119 
1120 /*
1121  * If there is no other address in the system that can serve a route to the
1122  * same prefix, remove the route.  Hand over the route to the new address
1123  * otherwise.
1124  */
1125 int
in_scrubprefix(struct in_ifaddr * target,u_int flags)1126 in_scrubprefix(struct in_ifaddr *target, u_int flags)
1127 {
1128 	struct epoch_tracker et;
1129 	struct in_ifaddr *ia;
1130 	struct in_addr prefix, mask, p, m;
1131 	int error = 0;
1132 
1133 	/*
1134 	 * Remove the loopback route to the interface address.
1135 	 */
1136 	if (ia_need_loopback_route(target) && (flags & LLE_STATIC)) {
1137 		struct in_ifaddr *eia;
1138 
1139 		eia = in_localip_more(target);
1140 
1141 		if (eia != NULL) {
1142 			error = ifa_switch_loopback_route((struct ifaddr *)eia,
1143 			    (struct sockaddr *)&target->ia_addr);
1144 			ifa_free(&eia->ia_ifa);
1145 		} else {
1146 			error = ifa_del_loopback_route((struct ifaddr *)target,
1147 			    (struct sockaddr *)&target->ia_addr);
1148 		}
1149 	}
1150 
1151 	ia_getrtprefix(target, &prefix, &mask);
1152 
1153 	if ((target->ia_flags & IFA_ROUTE) == 0) {
1154 		rt_addrmsg(RTM_DELETE, &target->ia_ifa, target->ia_ifp->if_fib);
1155 
1156 		/*
1157 		 * Removing address from !IFF_UP interface or
1158 		 * prefix which exists on other interface (along with route).
1159 		 * No entries should exist here except target addr.
1160 		 * Given that, delete this entry only.
1161 		 */
1162 		in_scrubprefixlle(target, 0, flags);
1163 		return (0);
1164 	}
1165 
1166 	NET_EPOCH_ENTER(et);
1167 	CK_STAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
1168 		ia_getrtprefix(ia, &p, &m);
1169 
1170 		if (prefix.s_addr != p.s_addr ||
1171 		    mask.s_addr != m.s_addr)
1172 			continue;
1173 
1174 		if ((ia->ia_ifp->if_flags & IFF_UP) == 0)
1175 			continue;
1176 
1177 		/*
1178 		 * If we got a matching prefix address, move IFA_ROUTE and
1179 		 * the route itself to it.  Make sure that routing daemons
1180 		 * get a heads-up.
1181 		 */
1182 		if ((ia->ia_flags & IFA_ROUTE) == 0) {
1183 			ifa_ref(&ia->ia_ifa);
1184 			NET_EPOCH_EXIT(et);
1185 			error = in_handle_ifaddr_route(RTM_DELETE, target);
1186 			if (error == 0)
1187 				target->ia_flags &= ~IFA_ROUTE;
1188 			else
1189 				log(LOG_INFO, "in_scrubprefix: err=%d, old prefix delete failed\n",
1190 					error);
1191 			/* Scrub all entries IFF interface is different */
1192 			in_scrubprefixlle(target, target->ia_ifp != ia->ia_ifp,
1193 			    flags);
1194 			error = in_handle_ifaddr_route(RTM_ADD, ia);
1195 			if (error == 0)
1196 				ia->ia_flags |= IFA_ROUTE;
1197 			else
1198 				log(LOG_INFO, "in_scrubprefix: err=%d, new prefix add failed\n",
1199 					error);
1200 			ifa_free(&ia->ia_ifa);
1201 			return (error);
1202 		}
1203 	}
1204 	NET_EPOCH_EXIT(et);
1205 
1206 	/*
1207 	 * remove all L2 entries on the given prefix
1208 	 */
1209 	in_scrubprefixlle(target, 1, flags);
1210 
1211 	/*
1212 	 * As no-one seem to have this prefix, we can remove the route.
1213 	 */
1214 	rt_addrmsg(RTM_DELETE, &target->ia_ifa, target->ia_ifp->if_fib);
1215 	error = in_handle_ifaddr_route(RTM_DELETE, target);
1216 	if (error == 0)
1217 		target->ia_flags &= ~IFA_ROUTE;
1218 	else
1219 		log(LOG_INFO, "in_scrubprefix: err=%d, prefix delete failed\n", error);
1220 	return (error);
1221 }
1222 
1223 void
in_ifscrub_all(void)1224 in_ifscrub_all(void)
1225 {
1226 	struct ifnet *ifp;
1227 	struct ifaddr *ifa, *nifa;
1228 	struct ifaliasreq ifr;
1229 
1230 	IFNET_RLOCK();
1231 	CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
1232 		/* Cannot lock here - lock recursion. */
1233 		/* NET_EPOCH_ENTER(et); */
1234 		CK_STAILQ_FOREACH_SAFE(ifa, &ifp->if_addrhead, ifa_link, nifa) {
1235 			if (ifa->ifa_addr->sa_family != AF_INET)
1236 				continue;
1237 
1238 			/*
1239 			 * This is ugly but the only way for legacy IP to
1240 			 * cleanly remove addresses and everything attached.
1241 			 */
1242 			bzero(&ifr, sizeof(ifr));
1243 			ifr.ifra_addr = *ifa->ifa_addr;
1244 			if (ifa->ifa_dstaddr)
1245 			ifr.ifra_broadaddr = *ifa->ifa_dstaddr;
1246 			(void)in_control(NULL, SIOCDIFADDR, (caddr_t)&ifr,
1247 			    ifp, NULL);
1248 		}
1249 		/* NET_EPOCH_EXIT(et); */
1250 		in_purgemaddrs(ifp);
1251 		igmp_domifdetach(ifp);
1252 	}
1253 	IFNET_RUNLOCK();
1254 }
1255 
1256 int
in_ifaddr_broadcast(struct in_addr in,struct in_ifaddr * ia)1257 in_ifaddr_broadcast(struct in_addr in, struct in_ifaddr *ia)
1258 {
1259 
1260 	return ((in.s_addr == ia->ia_broadaddr.sin_addr.s_addr ||
1261 	     /*
1262 	      * Optionally check for old-style (host 0) broadcast, but
1263 	      * taking into account that RFC 3021 obsoletes it.
1264 	      */
1265 	    (V_broadcast_lowest && ia->ia_subnetmask != IN_RFC3021_MASK &&
1266 	    ntohl(in.s_addr) == ia->ia_subnet)) &&
1267 	     /*
1268 	      * Check for an all one subnetmask. These
1269 	      * only exist when an interface gets a secondary
1270 	      * address.
1271 	      */
1272 	    ia->ia_subnetmask != (u_long)0xffffffff);
1273 }
1274 
1275 /*
1276  * Return 1 if the address might be a local broadcast address.
1277  */
1278 int
in_broadcast(struct in_addr in,struct ifnet * ifp)1279 in_broadcast(struct in_addr in, struct ifnet *ifp)
1280 {
1281 	struct ifaddr *ifa;
1282 	int found;
1283 
1284 	NET_EPOCH_ASSERT();
1285 
1286 	if (in.s_addr == INADDR_BROADCAST ||
1287 	    in.s_addr == INADDR_ANY)
1288 		return (1);
1289 	if ((ifp->if_flags & IFF_BROADCAST) == 0)
1290 		return (0);
1291 	found = 0;
1292 	/*
1293 	 * Look through the list of addresses for a match
1294 	 * with a broadcast address.
1295 	 */
1296 	CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
1297 		if (ifa->ifa_addr->sa_family == AF_INET &&
1298 		    in_ifaddr_broadcast(in, (struct in_ifaddr *)ifa)) {
1299 			found = 1;
1300 			break;
1301 		}
1302 	return (found);
1303 }
1304 
1305 /*
1306  * On interface removal, clean up IPv4 data structures hung off of the ifnet.
1307  */
1308 void
in_ifdetach(struct ifnet * ifp)1309 in_ifdetach(struct ifnet *ifp)
1310 {
1311 	IN_MULTI_LOCK();
1312 	in_pcbpurgeif0(&V_ripcbinfo, ifp);
1313 	in_pcbpurgeif0(&V_udbinfo, ifp);
1314 	in_pcbpurgeif0(&V_ulitecbinfo, ifp);
1315 	in_purgemaddrs(ifp);
1316 	IN_MULTI_UNLOCK();
1317 
1318 	/*
1319 	 * Make sure all multicast deletions invoking if_ioctl() are
1320 	 * completed before returning. Else we risk accessing a freed
1321 	 * ifnet structure pointer.
1322 	 */
1323 	inm_release_wait(NULL);
1324 }
1325 
1326 static void
in_ifnet_event(void * arg __unused,struct ifnet * ifp,int event)1327 in_ifnet_event(void *arg __unused, struct ifnet *ifp, int event)
1328 {
1329 	struct epoch_tracker et;
1330 	struct ifaddr *ifa;
1331 	struct in_ifaddr *ia;
1332 	int error;
1333 
1334 	NET_EPOCH_ENTER(et);
1335 	switch (event) {
1336 	case IFNET_EVENT_DOWN:
1337 		CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1338 			if (ifa->ifa_addr->sa_family != AF_INET)
1339 				continue;
1340 			ia = (struct in_ifaddr *)ifa;
1341 			if ((ia->ia_flags & IFA_ROUTE) == 0)
1342 				continue;
1343 			ifa_ref(ifa);
1344 			/*
1345 			 * in_scrubprefix() kills the interface route.
1346 			 */
1347 			in_scrubprefix(ia, 0);
1348 			/*
1349 			 * in_ifadown gets rid of all the rest of the
1350 			 * routes.  This is not quite the right thing
1351 			 * to do, but at least if we are running a
1352 			 * routing process they will come back.
1353 			 */
1354 			in_ifadown(ifa, 0);
1355 			ifa_free(ifa);
1356 		}
1357 		break;
1358 
1359 	case IFNET_EVENT_UP:
1360 		CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1361 			if (ifa->ifa_addr->sa_family != AF_INET)
1362 				continue;
1363 			ia = (struct in_ifaddr *)ifa;
1364 			if (ia->ia_flags & IFA_ROUTE)
1365 				continue;
1366 			ifa_ref(ifa);
1367 			error = ifa_del_loopback_route(ifa, ifa->ifa_addr);
1368 			rt_addrmsg(RTM_ADD, ifa, ifa->ifa_ifp->if_fib);
1369 			error = in_handle_ifaddr_route(RTM_ADD, ia);
1370 			if (error == 0)
1371 				ia->ia_flags |= IFA_ROUTE;
1372 			error = ifa_add_loopback_route(ifa, ifa->ifa_addr);
1373 			ifa_free(ifa);
1374 		}
1375 		break;
1376 	}
1377 	NET_EPOCH_EXIT(et);
1378 }
1379 EVENTHANDLER_DEFINE(ifnet_event, in_ifnet_event, NULL, EVENTHANDLER_PRI_ANY);
1380 
1381 /*
1382  * Delete all IPv4 multicast address records, and associated link-layer
1383  * multicast address records, associated with ifp.
1384  * XXX It looks like domifdetach runs AFTER the link layer cleanup.
1385  * XXX This should not race with ifma_protospec being set during
1386  * a new allocation, if it does, we have bigger problems.
1387  */
1388 static void
in_purgemaddrs(struct ifnet * ifp)1389 in_purgemaddrs(struct ifnet *ifp)
1390 {
1391 	struct epoch_tracker	 et;
1392 	struct in_multi_head purgeinms;
1393 	struct in_multi		*inm;
1394 	struct ifmultiaddr	*ifma;
1395 
1396 	SLIST_INIT(&purgeinms);
1397 	IN_MULTI_LIST_LOCK();
1398 
1399 	/*
1400 	 * Extract list of in_multi associated with the detaching ifp
1401 	 * which the PF_INET layer is about to release.
1402 	 * We need to do this as IF_ADDR_LOCK() may be re-acquired
1403 	 * by code further down.
1404 	 */
1405 	IF_ADDR_WLOCK(ifp);
1406 	NET_EPOCH_ENTER(et);
1407 	CK_STAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
1408 		inm = inm_ifmultiaddr_get_inm(ifma);
1409 		if (inm == NULL)
1410 			continue;
1411 		inm_rele_locked(&purgeinms, inm);
1412 	}
1413 	NET_EPOCH_EXIT(et);
1414 	IF_ADDR_WUNLOCK(ifp);
1415 
1416 	inm_release_list_deferred(&purgeinms);
1417 	igmp_ifdetach(ifp);
1418 	IN_MULTI_LIST_UNLOCK();
1419 }
1420 
1421 struct in_llentry {
1422 	struct llentry		base;
1423 };
1424 
1425 #define	IN_LLTBL_DEFAULT_HSIZE	32
1426 #define	IN_LLTBL_HASH(k, h) \
1427 	(((((((k >> 8) ^ k) >> 8) ^ k) >> 8) ^ k) & ((h) - 1))
1428 
1429 /*
1430  * Do actual deallocation of @lle.
1431  */
1432 static void
in_lltable_destroy_lle_unlocked(epoch_context_t ctx)1433 in_lltable_destroy_lle_unlocked(epoch_context_t ctx)
1434 {
1435 	struct llentry *lle;
1436 
1437 	lle = __containerof(ctx, struct llentry, lle_epoch_ctx);
1438 	LLE_LOCK_DESTROY(lle);
1439 	LLE_REQ_DESTROY(lle);
1440 	free(lle, M_LLTABLE);
1441 }
1442 
1443 /*
1444  * Called by LLE_FREE_LOCKED when number of references
1445  * drops to zero.
1446  */
1447 static void
in_lltable_destroy_lle(struct llentry * lle)1448 in_lltable_destroy_lle(struct llentry *lle)
1449 {
1450 
1451 	LLE_WUNLOCK(lle);
1452 	NET_EPOCH_CALL(in_lltable_destroy_lle_unlocked, &lle->lle_epoch_ctx);
1453 }
1454 
1455 static struct llentry *
in_lltable_new(struct in_addr addr4,u_int flags)1456 in_lltable_new(struct in_addr addr4, u_int flags)
1457 {
1458 	struct in_llentry *lle;
1459 
1460 	lle = malloc(sizeof(struct in_llentry), M_LLTABLE, M_NOWAIT | M_ZERO);
1461 	if (lle == NULL)		/* NB: caller generates msg */
1462 		return NULL;
1463 
1464 	/*
1465 	 * For IPv4 this will trigger "arpresolve" to generate
1466 	 * an ARP request.
1467 	 */
1468 	lle->base.la_expire = time_uptime; /* mark expired */
1469 	lle->base.r_l3addr.addr4 = addr4;
1470 	lle->base.lle_refcnt = 1;
1471 	lle->base.lle_free = in_lltable_destroy_lle;
1472 	LLE_LOCK_INIT(&lle->base);
1473 	LLE_REQ_INIT(&lle->base);
1474 	callout_init(&lle->base.lle_timer, 1);
1475 
1476 	return (&lle->base);
1477 }
1478 
1479 #define IN_ARE_MASKED_ADDR_EQUAL(d, a, m)	(		\
1480 	((((d).s_addr ^ (a).s_addr) & (m).s_addr)) == 0 )
1481 
1482 static int
in_lltable_match_prefix(const struct sockaddr * saddr,const struct sockaddr * smask,u_int flags,struct llentry * lle)1483 in_lltable_match_prefix(const struct sockaddr *saddr,
1484     const struct sockaddr *smask, u_int flags, struct llentry *lle)
1485 {
1486 	struct in_addr addr, mask, lle_addr;
1487 
1488 	addr = ((const struct sockaddr_in *)saddr)->sin_addr;
1489 	mask = ((const struct sockaddr_in *)smask)->sin_addr;
1490 	lle_addr.s_addr = ntohl(lle->r_l3addr.addr4.s_addr);
1491 
1492 	if (IN_ARE_MASKED_ADDR_EQUAL(lle_addr, addr, mask) == 0)
1493 		return (0);
1494 
1495 	if (lle->la_flags & LLE_IFADDR) {
1496 		/*
1497 		 * Delete LLE_IFADDR records IFF address & flag matches.
1498 		 * Note that addr is the interface address within prefix
1499 		 * being matched.
1500 		 * Note also we should handle 'ifdown' cases without removing
1501 		 * ifaddr macs.
1502 		 */
1503 		if (addr.s_addr == lle_addr.s_addr && (flags & LLE_STATIC) != 0)
1504 			return (1);
1505 		return (0);
1506 	}
1507 
1508 	/* flags & LLE_STATIC means deleting both dynamic and static entries */
1509 	if ((flags & LLE_STATIC) || !(lle->la_flags & LLE_STATIC))
1510 		return (1);
1511 
1512 	return (0);
1513 }
1514 
1515 static void
in_lltable_free_entry(struct lltable * llt,struct llentry * lle)1516 in_lltable_free_entry(struct lltable *llt, struct llentry *lle)
1517 {
1518 	size_t pkts_dropped;
1519 
1520 	LLE_WLOCK_ASSERT(lle);
1521 	KASSERT(llt != NULL, ("lltable is NULL"));
1522 
1523 	/* Unlink entry from table if not already */
1524 	if ((lle->la_flags & LLE_LINKED) != 0) {
1525 		IF_AFDATA_WLOCK_ASSERT(llt->llt_ifp);
1526 		lltable_unlink_entry(llt, lle);
1527 	}
1528 
1529 	/* Drop hold queue */
1530 	pkts_dropped = llentry_free(lle);
1531 	ARPSTAT_ADD(dropped, pkts_dropped);
1532 }
1533 
1534 static int
in_lltable_rtcheck(struct ifnet * ifp,u_int flags,const struct sockaddr * l3addr)1535 in_lltable_rtcheck(struct ifnet *ifp, u_int flags, const struct sockaddr *l3addr)
1536 {
1537 	struct nhop_object *nh;
1538 	struct in_addr addr;
1539 
1540 	KASSERT(l3addr->sa_family == AF_INET,
1541 	    ("sin_family %d", l3addr->sa_family));
1542 
1543 	addr = ((const struct sockaddr_in *)l3addr)->sin_addr;
1544 
1545 	nh = fib4_lookup(ifp->if_fib, addr, 0, NHR_NONE, 0);
1546 	if (nh == NULL)
1547 		return (EINVAL);
1548 
1549 	/*
1550 	 * If the gateway for an existing host route matches the target L3
1551 	 * address, which is a special route inserted by some implementation
1552 	 * such as MANET, and the interface is of the correct type, then
1553 	 * allow for ARP to proceed.
1554 	 */
1555 	if (nh->nh_flags & NHF_GATEWAY) {
1556 		if (!(nh->nh_flags & NHF_HOST) || nh->nh_ifp->if_type != IFT_ETHER ||
1557 		    (nh->nh_ifp->if_flags & (IFF_NOARP | IFF_STATICARP)) != 0 ||
1558 		    memcmp(nh->gw_sa.sa_data, l3addr->sa_data,
1559 		    sizeof(in_addr_t)) != 0) {
1560 			return (EINVAL);
1561 		}
1562 	}
1563 
1564 	/*
1565 	 * Make sure that at least the destination address is covered
1566 	 * by the route. This is for handling the case where 2 or more
1567 	 * interfaces have the same prefix. An incoming packet arrives
1568 	 * on one interface and the corresponding outgoing packet leaves
1569 	 * another interface.
1570 	 */
1571 	if ((nh->nh_ifp != ifp) && (nh->nh_flags & NHF_HOST) == 0) {
1572 		struct in_ifaddr *ia = (struct in_ifaddr *)ifaof_ifpforaddr(l3addr, ifp);
1573 		struct in_addr dst_addr, mask_addr;
1574 
1575 		if (ia == NULL)
1576 			return (EINVAL);
1577 
1578 		/*
1579 		 * ifaof_ifpforaddr() returns _best matching_ IFA.
1580 		 * It is possible that ifa prefix does not cover our address.
1581 		 * Explicitly verify and fail if that's the case.
1582 		 */
1583 		dst_addr = IA_SIN(ia)->sin_addr;
1584 		mask_addr.s_addr = htonl(ia->ia_subnetmask);
1585 
1586 		if (!IN_ARE_MASKED_ADDR_EQUAL(dst_addr, addr, mask_addr))
1587 			return (EINVAL);
1588 	}
1589 
1590 	return (0);
1591 }
1592 
1593 static inline uint32_t
in_lltable_hash_dst(const struct in_addr dst,uint32_t hsize)1594 in_lltable_hash_dst(const struct in_addr dst, uint32_t hsize)
1595 {
1596 
1597 	return (IN_LLTBL_HASH(dst.s_addr, hsize));
1598 }
1599 
1600 static uint32_t
in_lltable_hash(const struct llentry * lle,uint32_t hsize)1601 in_lltable_hash(const struct llentry *lle, uint32_t hsize)
1602 {
1603 
1604 	return (in_lltable_hash_dst(lle->r_l3addr.addr4, hsize));
1605 }
1606 
1607 static void
in_lltable_fill_sa_entry(const struct llentry * lle,struct sockaddr * sa)1608 in_lltable_fill_sa_entry(const struct llentry *lle, struct sockaddr *sa)
1609 {
1610 	struct sockaddr_in *sin;
1611 
1612 	sin = (struct sockaddr_in *)sa;
1613 	bzero(sin, sizeof(*sin));
1614 	sin->sin_family = AF_INET;
1615 	sin->sin_len = sizeof(*sin);
1616 	sin->sin_addr = lle->r_l3addr.addr4;
1617 }
1618 
1619 static inline struct llentry *
in_lltable_find_dst(struct lltable * llt,struct in_addr dst)1620 in_lltable_find_dst(struct lltable *llt, struct in_addr dst)
1621 {
1622 	struct llentry *lle;
1623 	struct llentries *lleh;
1624 	u_int hashidx;
1625 
1626 	hashidx = in_lltable_hash_dst(dst, llt->llt_hsize);
1627 	lleh = &llt->lle_head[hashidx];
1628 	CK_LIST_FOREACH(lle, lleh, lle_next) {
1629 		if (lle->la_flags & LLE_DELETED)
1630 			continue;
1631 		if (lle->r_l3addr.addr4.s_addr == dst.s_addr)
1632 			break;
1633 	}
1634 
1635 	return (lle);
1636 }
1637 
1638 static void
in_lltable_delete_entry(struct lltable * llt,struct llentry * lle)1639 in_lltable_delete_entry(struct lltable *llt, struct llentry *lle)
1640 {
1641 
1642 	lle->la_flags |= LLE_DELETED;
1643 	EVENTHANDLER_INVOKE(lle_event, lle, LLENTRY_DELETED);
1644 #ifdef DIAGNOSTIC
1645 	log(LOG_INFO, "ifaddr cache = %p is deleted\n", lle);
1646 #endif
1647 	llentry_free(lle);
1648 }
1649 
1650 static struct llentry *
in_lltable_alloc(struct lltable * llt,u_int flags,const struct sockaddr * l3addr)1651 in_lltable_alloc(struct lltable *llt, u_int flags, const struct sockaddr *l3addr)
1652 {
1653 	const struct sockaddr_in *sin = (const struct sockaddr_in *)l3addr;
1654 	struct ifnet *ifp = llt->llt_ifp;
1655 	struct llentry *lle;
1656 	char linkhdr[LLE_MAX_LINKHDR];
1657 	size_t linkhdrsize;
1658 	int lladdr_off;
1659 
1660 	KASSERT(l3addr->sa_family == AF_INET,
1661 	    ("sin_family %d", l3addr->sa_family));
1662 
1663 	/*
1664 	 * A route that covers the given address must have
1665 	 * been installed 1st because we are doing a resolution,
1666 	 * verify this.
1667 	 */
1668 	if (!(flags & LLE_IFADDR) &&
1669 	    in_lltable_rtcheck(ifp, flags, l3addr) != 0)
1670 		return (NULL);
1671 
1672 	lle = in_lltable_new(sin->sin_addr, flags);
1673 	if (lle == NULL) {
1674 		log(LOG_INFO, "lla_lookup: new lle malloc failed\n");
1675 		return (NULL);
1676 	}
1677 	lle->la_flags = flags;
1678 	if (flags & LLE_STATIC)
1679 		lle->r_flags |= RLLE_VALID;
1680 	if ((flags & LLE_IFADDR) == LLE_IFADDR) {
1681 		linkhdrsize = LLE_MAX_LINKHDR;
1682 		if (lltable_calc_llheader(ifp, AF_INET, IF_LLADDR(ifp),
1683 		    linkhdr, &linkhdrsize, &lladdr_off) != 0) {
1684 			in_lltable_free_entry(llt, lle);
1685 			return (NULL);
1686 		}
1687 		lltable_set_entry_addr(ifp, lle, linkhdr, linkhdrsize,
1688 		    lladdr_off);
1689 		lle->la_flags |= LLE_STATIC;
1690 		lle->r_flags |= (RLLE_VALID | RLLE_IFADDR);
1691 		lle->la_expire = 0;
1692 	}
1693 
1694 	return (lle);
1695 }
1696 
1697 /*
1698  * Return NULL if not found or marked for deletion.
1699  * If found return lle read locked.
1700  */
1701 static struct llentry *
in_lltable_lookup(struct lltable * llt,u_int flags,const struct sockaddr * l3addr)1702 in_lltable_lookup(struct lltable *llt, u_int flags, const struct sockaddr *l3addr)
1703 {
1704 	const struct sockaddr_in *sin = (const struct sockaddr_in *)l3addr;
1705 	struct llentry *lle;
1706 
1707 	IF_AFDATA_LOCK_ASSERT(llt->llt_ifp);
1708 	KASSERT(l3addr->sa_family == AF_INET,
1709 	    ("sin_family %d", l3addr->sa_family));
1710 	KASSERT((flags & (LLE_UNLOCKED | LLE_EXCLUSIVE)) !=
1711 	    (LLE_UNLOCKED | LLE_EXCLUSIVE),
1712 	    ("wrong lle request flags: %#x", flags));
1713 
1714 	lle = in_lltable_find_dst(llt, sin->sin_addr);
1715 	if (lle == NULL)
1716 		return (NULL);
1717 	if (flags & LLE_UNLOCKED)
1718 		return (lle);
1719 
1720 	if (flags & LLE_EXCLUSIVE)
1721 		LLE_WLOCK(lle);
1722 	else
1723 		LLE_RLOCK(lle);
1724 
1725 	/*
1726 	 * If the afdata lock is not held, the LLE may have been unlinked while
1727 	 * we were blocked on the LLE lock.  Check for this case.
1728 	 */
1729 	if (__predict_false((lle->la_flags & LLE_LINKED) == 0)) {
1730 		if (flags & LLE_EXCLUSIVE)
1731 			LLE_WUNLOCK(lle);
1732 		else
1733 			LLE_RUNLOCK(lle);
1734 		return (NULL);
1735 	}
1736 	return (lle);
1737 }
1738 
1739 static int
in_lltable_dump_entry(struct lltable * llt,struct llentry * lle,struct sysctl_req * wr)1740 in_lltable_dump_entry(struct lltable *llt, struct llentry *lle,
1741     struct sysctl_req *wr)
1742 {
1743 	struct ifnet *ifp = llt->llt_ifp;
1744 	/* XXX stack use */
1745 	struct {
1746 		struct rt_msghdr	rtm;
1747 		struct sockaddr_in	sin;
1748 		struct sockaddr_dl	sdl;
1749 	} arpc;
1750 	struct sockaddr_dl *sdl;
1751 	int error;
1752 
1753 	bzero(&arpc, sizeof(arpc));
1754 	/* skip deleted entries */
1755 	if ((lle->la_flags & LLE_DELETED) == LLE_DELETED)
1756 		return (0);
1757 	/* Skip if jailed and not a valid IP of the prison. */
1758 	lltable_fill_sa_entry(lle,(struct sockaddr *)&arpc.sin);
1759 	if (prison_if(wr->td->td_ucred, (struct sockaddr *)&arpc.sin) != 0)
1760 		return (0);
1761 	/*
1762 	 * produce a msg made of:
1763 	 *  struct rt_msghdr;
1764 	 *  struct sockaddr_in; (IPv4)
1765 	 *  struct sockaddr_dl;
1766 	 */
1767 	arpc.rtm.rtm_msglen = sizeof(arpc);
1768 	arpc.rtm.rtm_version = RTM_VERSION;
1769 	arpc.rtm.rtm_type = RTM_GET;
1770 	arpc.rtm.rtm_flags = RTF_UP;
1771 	arpc.rtm.rtm_addrs = RTA_DST | RTA_GATEWAY;
1772 
1773 	/* publish */
1774 	if (lle->la_flags & LLE_PUB)
1775 		arpc.rtm.rtm_flags |= RTF_ANNOUNCE;
1776 
1777 	sdl = &arpc.sdl;
1778 	sdl->sdl_family = AF_LINK;
1779 	sdl->sdl_len = sizeof(*sdl);
1780 	sdl->sdl_index = ifp->if_index;
1781 	sdl->sdl_type = ifp->if_type;
1782 	if ((lle->la_flags & LLE_VALID) == LLE_VALID) {
1783 		sdl->sdl_alen = ifp->if_addrlen;
1784 		bcopy(lle->ll_addr, LLADDR(sdl), ifp->if_addrlen);
1785 	} else {
1786 		sdl->sdl_alen = 0;
1787 		bzero(LLADDR(sdl), ifp->if_addrlen);
1788 	}
1789 
1790 	arpc.rtm.rtm_rmx.rmx_expire =
1791 	    lle->la_flags & LLE_STATIC ? 0 : lle->la_expire;
1792 	arpc.rtm.rtm_flags |= (RTF_HOST | RTF_LLDATA);
1793 	if (lle->la_flags & LLE_STATIC)
1794 		arpc.rtm.rtm_flags |= RTF_STATIC;
1795 	if (lle->la_flags & LLE_IFADDR)
1796 		arpc.rtm.rtm_flags |= RTF_PINNED;
1797 	arpc.rtm.rtm_index = ifp->if_index;
1798 	error = SYSCTL_OUT(wr, &arpc, sizeof(arpc));
1799 
1800 	return (error);
1801 }
1802 
1803 static void
in_lltable_post_resolved(struct lltable * llt,struct llentry * lle)1804 in_lltable_post_resolved(struct lltable *llt, struct llentry *lle)
1805 {
1806 	struct ifnet *ifp = llt->llt_ifp;
1807 
1808 	/* gratuitous ARP */
1809 	if ((lle->la_flags & LLE_PUB) != 0)
1810 		arprequest(ifp, &lle->r_l3addr.addr4, &lle->r_l3addr.addr4,
1811 		    lle->ll_addr);
1812 }
1813 
1814 static struct lltable *
in_lltattach(struct ifnet * ifp)1815 in_lltattach(struct ifnet *ifp)
1816 {
1817 	struct lltable *llt;
1818 
1819 	llt = lltable_allocate_htbl(IN_LLTBL_DEFAULT_HSIZE);
1820  	llt->llt_af = AF_INET;
1821  	llt->llt_ifp = ifp;
1822 
1823 	llt->llt_lookup = in_lltable_lookup;
1824 	llt->llt_alloc_entry = in_lltable_alloc;
1825 	llt->llt_delete_entry = in_lltable_delete_entry;
1826 	llt->llt_dump_entry = in_lltable_dump_entry;
1827 	llt->llt_hash = in_lltable_hash;
1828 	llt->llt_fill_sa_entry = in_lltable_fill_sa_entry;
1829 	llt->llt_free_entry = in_lltable_free_entry;
1830 	llt->llt_match_prefix = in_lltable_match_prefix;
1831 	llt->llt_mark_used = llentry_mark_used;
1832 	llt->llt_post_resolved = in_lltable_post_resolved;
1833  	lltable_link(llt);
1834 
1835 	return (llt);
1836 }
1837 
1838 struct lltable *
in_lltable_get(struct ifnet * ifp)1839 in_lltable_get(struct ifnet *ifp)
1840 {
1841 	struct lltable *llt = NULL;
1842 
1843 	void *afdata_ptr = ifp->if_afdata[AF_INET];
1844 	if (afdata_ptr != NULL)
1845 		llt = ((struct in_ifinfo *)afdata_ptr)->ii_llt;
1846 	return (llt);
1847 }
1848 
1849 void *
in_domifattach(struct ifnet * ifp)1850 in_domifattach(struct ifnet *ifp)
1851 {
1852 	struct in_ifinfo *ii;
1853 
1854 	ii = malloc(sizeof(struct in_ifinfo), M_IFADDR, M_WAITOK|M_ZERO);
1855 
1856 	ii->ii_llt = in_lltattach(ifp);
1857 	ii->ii_igmp = igmp_domifattach(ifp);
1858 
1859 	return (ii);
1860 }
1861 
1862 void
in_domifdetach(struct ifnet * ifp,void * aux)1863 in_domifdetach(struct ifnet *ifp, void *aux)
1864 {
1865 	struct in_ifinfo *ii = (struct in_ifinfo *)aux;
1866 
1867 	igmp_domifdetach(ifp);
1868 	lltable_free(ii->ii_llt);
1869 	free(ii, M_IFADDR);
1870 }
1871