xref: /freebsd/sys/netinet/in.c (revision 7b71f57f4e514a2ab7308ce4147e14d90e099ad0)
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 
33 #include "opt_inet.h"
34 
35 #define IN_HISTORICAL_NETS		/* include class masks */
36 
37 #include <sys/param.h>
38 #include <sys/eventhandler.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/lock.h>
47 #include <sys/proc.h>
48 #include <sys/sysctl.h>
49 #include <sys/syslog.h>
50 #include <sys/sx.h>
51 
52 #include <net/if.h>
53 #include <net/if_var.h>
54 #include <net/if_arp.h>
55 #include <net/if_dl.h>
56 #include <net/if_llatbl.h>
57 #include <net/if_private.h>
58 #include <net/if_types.h>
59 #include <net/if_bridgevar.h>
60 #include <net/route.h>
61 #include <net/route/nhop.h>
62 #include <net/route/route_ctl.h>
63 #include <net/vnet.h>
64 
65 #include <netinet/if_ether.h>
66 #include <netinet/in.h>
67 #include <netinet/in_fib.h>
68 #include <netinet/in_var.h>
69 #include <netinet/in_pcb.h>
70 #include <netinet/ip_var.h>
71 #include <netinet/ip_carp.h>
72 #include <netinet/igmp_var.h>
73 #include <netinet/udp.h>
74 #include <netinet/udp_var.h>
75 
76 #ifdef MAC
77 #include <security/mac/mac_framework.h>
78 #endif
79 
80 static int in_aifaddr_ioctl(u_long, caddr_t, struct ifnet *, struct ucred *);
81 static int in_difaddr_ioctl(u_long, caddr_t, struct ifnet *, struct ucred *);
82 static int in_gifaddr_ioctl(u_long, caddr_t, struct ifnet *, struct ucred *);
83 
84 static void	in_socktrim(struct sockaddr_in *);
85 static void	in_purgemaddrs(struct ifnet *);
86 
87 static bool	ia_need_loopback_route(const struct in_ifaddr *);
88 
89 VNET_DEFINE_STATIC(int, nosameprefix);
90 #define	V_nosameprefix			VNET(nosameprefix)
91 SYSCTL_INT(_net_inet_ip, OID_AUTO, no_same_prefix, CTLFLAG_VNET | CTLFLAG_RW,
92 	&VNET_NAME(nosameprefix), 0,
93 	"Refuse to create same prefixes on different interfaces");
94 
95 VNET_DEFINE_STATIC(bool, broadcast_lowest);
96 #define	V_broadcast_lowest		VNET(broadcast_lowest)
97 SYSCTL_BOOL(_net_inet_ip, OID_AUTO, broadcast_lowest, CTLFLAG_VNET | CTLFLAG_RW,
98 	&VNET_NAME(broadcast_lowest), 0,
99 	"Treat lowest address on a subnet (host 0) as broadcast");
100 
101 VNET_DEFINE(bool, ip_allow_net240) = false;
102 #define	V_ip_allow_net240		VNET(ip_allow_net240)
103 SYSCTL_BOOL(_net_inet_ip, OID_AUTO, allow_net240,
104 	CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip_allow_net240), 0,
105 	"Allow forwarding of and ICMP response to Experimental addresses, aka Class E (240/4)");
106 /* see https://datatracker.ietf.org/doc/draft-schoen-intarea-unicast-240 */
107 
108 VNET_DEFINE(bool, ip_allow_net0) = false;
109 SYSCTL_BOOL(_net_inet_ip, OID_AUTO, allow_net0,
110 	CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip_allow_net0), 0,
111 	"Allow forwarding of and ICMP response to addresses in network 0/8");
112 /* see https://datatracker.ietf.org/doc/draft-schoen-intarea-unicast-0 */
113 
114 VNET_DEFINE(uint32_t, in_loopback_mask) = IN_LOOPBACK_MASK_DFLT;
115 #define	V_in_loopback_mask	VNET(in_loopback_mask)
116 static int sysctl_loopback_prefixlen(SYSCTL_HANDLER_ARGS);
117 SYSCTL_PROC(_net_inet_ip, OID_AUTO, loopback_prefixlen,
118 	CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW,
119 	NULL, 0, sysctl_loopback_prefixlen, "I",
120 	"Prefix length of address space reserved for loopback");
121 /* see https://datatracker.ietf.org/doc/draft-schoen-intarea-unicast-127 */
122 
123 VNET_DECLARE(struct inpcbinfo, ripcbinfo);
124 #define	V_ripcbinfo			VNET(ripcbinfo)
125 
126 static struct sx in_control_sx;
127 SX_SYSINIT(in_control_sx, &in_control_sx, "in_control");
128 
129 /*
130  * Return true if an internet address is for a ``local'' host
131  * (one to which we have a connection).
132  */
133 bool
in_localaddr(struct in_addr in)134 in_localaddr(struct in_addr in)
135 {
136 	u_long i = ntohl(in.s_addr);
137 	struct in_ifaddr *ia;
138 
139 	NET_EPOCH_ASSERT();
140 
141 	CK_STAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
142 		if ((i & ia->ia_subnetmask) == ia->ia_subnet)
143 			return (true);
144 	}
145 
146 	return (false);
147 }
148 
149 /*
150  * Return true if an internet address is for the local host and configured
151  * on one of its interfaces.
152  */
153 bool
in_localip(struct in_addr in)154 in_localip(struct in_addr in)
155 {
156 	struct in_ifaddr *ia;
157 
158 	NET_EPOCH_ASSERT();
159 
160 	CK_LIST_FOREACH(ia, INADDR_HASH(in.s_addr), ia_hash)
161 		if (IA_SIN(ia)->sin_addr.s_addr == in.s_addr)
162 			return (true);
163 
164 	return (false);
165 }
166 
167 /*
168  * Like in_localip(), but FIB-aware and carp(4)-aware.
169  */
170 bool
in_localip_fib(struct in_addr in,uint16_t fib)171 in_localip_fib(struct in_addr in, uint16_t fib)
172 {
173 	struct in_ifaddr *ia;
174 
175 	NET_EPOCH_ASSERT();
176 
177 	CK_LIST_FOREACH(ia, INADDR_HASH(in.s_addr), ia_hash)
178 		if (IA_SIN(ia)->sin_addr.s_addr == in.s_addr &&
179 		    (ia->ia_ifa.ifa_carp == NULL ||
180 		    carp_master_p(&ia->ia_ifa)) &&
181 		    ia->ia_ifa.ifa_ifp->if_fib == fib)
182 			return (true);
183 
184 	return (false);
185 }
186 
187 /*
188  * Return true if an internet address is configured on an interface.
189  */
190 bool
in_ifhasaddr(struct ifnet * ifp,struct in_addr in)191 in_ifhasaddr(struct ifnet *ifp, struct in_addr in)
192 {
193 	struct ifaddr *ifa;
194 	struct in_ifaddr *ia;
195 
196 	NET_EPOCH_ASSERT();
197 
198 	CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
199 		if (ifa->ifa_addr->sa_family != AF_INET)
200 			continue;
201 		ia = (struct in_ifaddr *)ifa;
202 		if (ia->ia_addr.sin_addr.s_addr == in.s_addr)
203 			return (true);
204 	}
205 
206 	return (false);
207 }
208 
209 /*
210  * Return a reference to the interface address which is different to
211  * the supplied one but with same IP address value.
212  */
213 static struct in_ifaddr *
in_localip_more(struct in_ifaddr * original_ia)214 in_localip_more(struct in_ifaddr *original_ia)
215 {
216 	struct epoch_tracker et;
217 	in_addr_t original_addr = IA_SIN(original_ia)->sin_addr.s_addr;
218 	uint32_t original_fib = original_ia->ia_ifa.ifa_ifp->if_fib;
219 	struct in_ifaddr *ia;
220 
221 	NET_EPOCH_ENTER(et);
222 	CK_LIST_FOREACH(ia, INADDR_HASH(original_addr), ia_hash) {
223 		in_addr_t addr = IA_SIN(ia)->sin_addr.s_addr;
224 		uint32_t fib = ia->ia_ifa.ifa_ifp->if_fib;
225 		if (!V_rt_add_addr_allfibs && (original_fib != fib))
226 			continue;
227 		if ((original_ia != ia) && (original_addr == addr)) {
228 			ifa_ref(&ia->ia_ifa);
229 			NET_EPOCH_EXIT(et);
230 			return (ia);
231 		}
232 	}
233 	NET_EPOCH_EXIT(et);
234 
235 	return (NULL);
236 }
237 
238 /*
239  * Tries to find first IPv4 address in the provided fib.
240  * Prefers non-loopback addresses and return loopback IFF
241  * @loopback_ok is set.
242  *
243  * Returns ifa or NULL.
244  */
245 struct in_ifaddr *
in_findlocal(uint32_t fibnum,bool loopback_ok)246 in_findlocal(uint32_t fibnum, bool loopback_ok)
247 {
248 	struct in_ifaddr *ia = NULL, *ia_lo = NULL;
249 
250 	NET_EPOCH_ASSERT();
251 
252 	CK_STAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
253 		uint32_t ia_fib = ia->ia_ifa.ifa_ifp->if_fib;
254 		if (!V_rt_add_addr_allfibs && (fibnum != ia_fib))
255 			continue;
256 
257 		if (!IN_LOOPBACK(ntohl(IA_SIN(ia)->sin_addr.s_addr)))
258 			break;
259 		if (loopback_ok)
260 			ia_lo = ia;
261 	}
262 
263 	if (ia == NULL)
264 		ia = ia_lo;
265 
266 	return (ia);
267 }
268 
269 /*
270  * Determine whether an IP address is in a reserved set of addresses
271  * that may not be forwarded, or whether datagrams to that destination
272  * may be forwarded.
273  */
274 bool
in_canforward(struct in_addr in)275 in_canforward(struct in_addr in)
276 {
277 	u_long i = ntohl(in.s_addr);
278 
279 	if (IN_MULTICAST(i) || IN_LINKLOCAL(i) || IN_LOOPBACK(i) ||
280 	    in_nullhost(in))
281 		return (false);
282 	if (IN_EXPERIMENTAL(i) && !V_ip_allow_net240)
283 		return (false);
284 	if (IN_ZERONET(i) && !V_ip_allow_net0)
285 		return (false);
286 	return (true);
287 }
288 
289 /*
290  * Sysctl to manage prefix of reserved loopback network; translate
291  * to/from mask.  The mask is always contiguous high-order 1 bits
292  * followed by all 0 bits.
293  */
294 static int
sysctl_loopback_prefixlen(SYSCTL_HANDLER_ARGS)295 sysctl_loopback_prefixlen(SYSCTL_HANDLER_ARGS)
296 {
297 	int error, preflen;
298 
299 	/* ffs is 1-based; compensate. */
300 	preflen = 33 - ffs(V_in_loopback_mask);
301 	error = sysctl_handle_int(oidp, &preflen, 0, req);
302 	if (error || !req->newptr)
303 		return (error);
304 	if (preflen < 8 || preflen > 31)
305 		return (EINVAL);
306 	V_in_loopback_mask = 0xffffffff << (32 - preflen);
307 	return (0);
308 }
309 
310 /*
311  * Trim a mask in a sockaddr
312  */
313 static void
in_socktrim(struct sockaddr_in * ap)314 in_socktrim(struct sockaddr_in *ap)
315 {
316     char *cplim = (char *) &ap->sin_addr;
317     char *cp = (char *) (&ap->sin_addr + 1);
318 
319     ap->sin_len = 0;
320     while (--cp >= cplim)
321 	if (*cp) {
322 	    (ap)->sin_len = cp - (char *) (ap) + 1;
323 	    break;
324 	}
325 }
326 
327 /*
328  * Generic internet control operations (ioctl's).
329  */
330 int
in_control_ioctl(u_long cmd,void * data,struct ifnet * ifp,struct ucred * cred)331 in_control_ioctl(u_long cmd, void *data, struct ifnet *ifp,
332     struct ucred *cred)
333 {
334 	struct ifreq *ifr = (struct ifreq *)data;
335 	struct sockaddr_in *addr = (struct sockaddr_in *)&ifr->ifr_addr;
336 	struct epoch_tracker et;
337 	struct ifaddr *ifa;
338 	struct in_ifaddr *ia;
339 	int error;
340 
341 	if (ifp == NULL)
342 		return (EADDRNOTAVAIL);
343 
344 	/*
345 	 * Filter out 4 ioctls we implement directly.  Forward the rest
346 	 * to specific functions and ifp->if_ioctl().
347 	 */
348 	switch (cmd) {
349 	case SIOCGIFADDR:
350 	case SIOCGIFBRDADDR:
351 	case SIOCGIFDSTADDR:
352 	case SIOCGIFNETMASK:
353 		break;
354 	case SIOCGIFALIAS:
355 		sx_xlock(&in_control_sx);
356 		error = in_gifaddr_ioctl(cmd, data, ifp, cred);
357 		sx_xunlock(&in_control_sx);
358 		return (error);
359 	case SIOCDIFADDR:
360 		sx_xlock(&in_control_sx);
361 		error = in_difaddr_ioctl(cmd, data, ifp, cred);
362 		sx_xunlock(&in_control_sx);
363 		return (error);
364 	case OSIOCAIFADDR:	/* 9.x compat */
365 	case SIOCAIFADDR:
366 		sx_xlock(&in_control_sx);
367 		error = in_aifaddr_ioctl(cmd, data, ifp, cred);
368 		sx_xunlock(&in_control_sx);
369 		return (error);
370 	case SIOCSIFADDR:
371 	case SIOCSIFBRDADDR:
372 	case SIOCSIFDSTADDR:
373 	case SIOCSIFNETMASK:
374 		/* We no longer support that old commands. */
375 		return (EINVAL);
376 	default:
377 		if (ifp->if_ioctl == NULL)
378 			return (EOPNOTSUPP);
379 		return ((*ifp->if_ioctl)(ifp, cmd, data));
380 	}
381 
382 	if (addr->sin_addr.s_addr != INADDR_ANY &&
383 	    prison_check_ip4(cred, &addr->sin_addr) != 0)
384 		return (EADDRNOTAVAIL);
385 
386 	/*
387 	 * Find address for this interface, if it exists.  If an
388 	 * address was specified, find that one instead of the
389 	 * first one on the interface, if possible.
390 	 */
391 	NET_EPOCH_ENTER(et);
392 	CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
393 		if (ifa->ifa_addr->sa_family != AF_INET)
394 			continue;
395 		ia = (struct in_ifaddr *)ifa;
396 		if (ia->ia_addr.sin_addr.s_addr == addr->sin_addr.s_addr)
397 			break;
398 	}
399 	if (ifa == NULL)
400 		CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
401 			if (ifa->ifa_addr->sa_family == AF_INET) {
402 				ia = (struct in_ifaddr *)ifa;
403 				if (prison_check_ip4(cred,
404 				    &ia->ia_addr.sin_addr) == 0)
405 					break;
406 			}
407 
408 	if (ifa == NULL) {
409 		NET_EPOCH_EXIT(et);
410 		return (EADDRNOTAVAIL);
411 	}
412 
413 	error = 0;
414 	switch (cmd) {
415 	case SIOCGIFADDR:
416 		*addr = ia->ia_addr;
417 		break;
418 
419 	case SIOCGIFBRDADDR:
420 		if ((ifp->if_flags & IFF_BROADCAST) == 0) {
421 			error = EINVAL;
422 			break;
423 		}
424 		*addr = ia->ia_broadaddr;
425 		break;
426 
427 	case SIOCGIFDSTADDR:
428 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0) {
429 			error = EINVAL;
430 			break;
431 		}
432 		*addr = ia->ia_dstaddr;
433 		break;
434 
435 	case SIOCGIFNETMASK:
436 		*addr = ia->ia_sockmask;
437 		break;
438 	}
439 
440 	NET_EPOCH_EXIT(et);
441 
442 	return (error);
443 }
444 
445 int
in_mask2len(struct in_addr * mask)446 in_mask2len(struct in_addr *mask)
447 {
448 	int x, y;
449 	u_char *p;
450 
451 	p = (u_char *)mask;
452 	for (x = 0; x < sizeof(*mask); x++) {
453 		if (p[x] != 0xff)
454 			break;
455 	}
456 	y = 0;
457 	if (x < sizeof(*mask)) {
458 		for (y = 0; y < 8; y++) {
459 			if ((p[x] & (0x80 >> y)) == 0)
460 				break;
461 		}
462 	}
463 	return (x * 8 + y);
464 }
465 
466 int
in_control(struct socket * so,u_long cmd,void * data,struct ifnet * ifp,struct thread * td)467 in_control(struct socket *so, u_long cmd, void *data, struct ifnet *ifp,
468     struct thread *td)
469 {
470 	return (in_control_ioctl(cmd, data, ifp, td ? td->td_ucred : NULL));
471 }
472 
473 static int
in_aifaddr_ioctl(u_long cmd,caddr_t data,struct ifnet * ifp,struct ucred * cred)474 in_aifaddr_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp, struct ucred *cred)
475 {
476 	const struct in_aliasreq *ifra = (struct in_aliasreq *)data;
477 	const struct sockaddr_in *addr = &ifra->ifra_addr;
478 	const struct sockaddr_in *broadaddr = &ifra->ifra_broadaddr;
479 	const struct sockaddr_in *mask = &ifra->ifra_mask;
480 	const struct sockaddr_in *dstaddr = &ifra->ifra_dstaddr;
481 	const int vhid = (cmd == SIOCAIFADDR) ? ifra->ifra_vhid : 0;
482 	struct epoch_tracker et;
483 	struct ifaddr *ifa;
484 	struct in_ifaddr *ia;
485 	bool iaIsFirst;
486 	int error = 0;
487 
488 	error = priv_check_cred(cred, PRIV_NET_ADDIFADDR);
489 	if (error)
490 		return (error);
491 
492 	/*
493 	 * ifra_addr must be present and be of INET family.
494 	 * ifra_broadaddr/ifra_dstaddr and ifra_mask are optional.
495 	 */
496 	if (addr->sin_len != sizeof(struct sockaddr_in) ||
497 	    addr->sin_family != AF_INET)
498 		return (EINVAL);
499 	if (broadaddr->sin_len != 0 &&
500 	    (broadaddr->sin_len != sizeof(struct sockaddr_in) ||
501 	    broadaddr->sin_family != AF_INET))
502 		return (EINVAL);
503 	if (mask->sin_len != 0 &&
504 	    (mask->sin_len != sizeof(struct sockaddr_in) ||
505 	    mask->sin_family != AF_INET))
506 		return (EINVAL);
507 	if ((ifp->if_flags & IFF_POINTOPOINT) &&
508 	    (dstaddr->sin_len != sizeof(struct sockaddr_in) ||
509 	     dstaddr->sin_addr.s_addr == INADDR_ANY))
510 		return (EDESTADDRREQ);
511 	if (vhid != 0 && carp_attach_p == NULL)
512 		return (EPROTONOSUPPORT);
513 
514 #ifdef MAC
515 	/* Check if a MAC policy disallows setting the IPv4 address. */
516 	error = mac_inet_check_add_addr(cred, &addr->sin_addr, ifp);
517 	if (error != 0)
518 		return (error);
519 #endif
520 
521 	/*
522 	 * Check if bridge wants to allow adding addrs to member interfaces.
523 	 */
524 	if (ifp->if_bridge != NULL && ifp->if_type != IFT_GIF &&
525 	    bridge_member_ifaddrs_p != NULL) {
526 		if (bridge_member_ifaddrs_p())
527 			if_printf(ifp, "WARNING: Assigning an IP address to "
528 			    "an interface which is also a bridge member is "
529 			    "deprecated and will be unsupported in a future "
530 			    "release.\n");
531 		else
532 			return (EINVAL);
533 	}
534 
535 	/*
536 	 * See whether address already exist.
537 	 */
538 	iaIsFirst = true;
539 	ia = NULL;
540 	NET_EPOCH_ENTER(et);
541 	CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
542 		struct in_ifaddr *it;
543 
544 		if (ifa->ifa_addr->sa_family != AF_INET)
545 			continue;
546 
547 		it = (struct in_ifaddr *)ifa;
548 		if (it->ia_addr.sin_addr.s_addr == addr->sin_addr.s_addr &&
549 		    prison_check_ip4(cred, &addr->sin_addr) == 0)
550 			ia = it;
551 		else
552 			iaIsFirst = false;
553 	}
554 	NET_EPOCH_EXIT(et);
555 
556 	if (ia != NULL)
557 		(void )in_difaddr_ioctl(cmd, data, ifp, cred);
558 
559 	ifa = ifa_alloc(sizeof(struct in_ifaddr), M_WAITOK);
560 	ia = (struct in_ifaddr *)ifa;
561 	ifa->ifa_addr = (struct sockaddr *)&ia->ia_addr;
562 	ifa->ifa_dstaddr = (struct sockaddr *)&ia->ia_dstaddr;
563 	ifa->ifa_netmask = (struct sockaddr *)&ia->ia_sockmask;
564 	callout_init_rw(&ia->ia_garp_timer, &ifp->if_addr_lock,
565 	    CALLOUT_RETURNUNLOCKED);
566 
567 	ia->ia_ifp = ifp;
568 	ia->ia_addr = *addr;
569 	if (mask->sin_len != 0) {
570 		ia->ia_sockmask = *mask;
571 		ia->ia_subnetmask = ntohl(ia->ia_sockmask.sin_addr.s_addr);
572 	} else {
573 		in_addr_t i = ntohl(addr->sin_addr.s_addr);
574 
575 		/*
576 	 	 * If netmask isn't supplied, use historical default.
577 		 * This is deprecated for interfaces other than loopback
578 		 * or point-to-point; warn in other cases.  In the future
579 		 * we should return an error rather than warning.
580 	 	 */
581 		if ((ifp->if_flags & (IFF_POINTOPOINT | IFF_LOOPBACK)) == 0)
582 			printf("%s: set address: WARNING: network mask "
583 			     "should be specified; using historical default\n",
584 			     ifp->if_xname);
585 		if (IN_CLASSA(i))
586 			ia->ia_subnetmask = IN_CLASSA_NET;
587 		else if (IN_CLASSB(i))
588 			ia->ia_subnetmask = IN_CLASSB_NET;
589 		else
590 			ia->ia_subnetmask = IN_CLASSC_NET;
591 		ia->ia_sockmask.sin_addr.s_addr = htonl(ia->ia_subnetmask);
592 	}
593 	ia->ia_subnet = ntohl(addr->sin_addr.s_addr) & ia->ia_subnetmask;
594 	in_socktrim(&ia->ia_sockmask);
595 
596 	if (ifp->if_flags & IFF_BROADCAST) {
597 		if (broadaddr->sin_len != 0) {
598 			ia->ia_broadaddr = *broadaddr;
599 		} else if (ia->ia_subnetmask == IN_RFC3021_MASK) {
600 			ia->ia_broadaddr.sin_addr.s_addr = INADDR_BROADCAST;
601 			ia->ia_broadaddr.sin_len = sizeof(struct sockaddr_in);
602 			ia->ia_broadaddr.sin_family = AF_INET;
603 		} else {
604 			ia->ia_broadaddr.sin_addr.s_addr =
605 			    htonl(ia->ia_subnet | ~ia->ia_subnetmask);
606 			ia->ia_broadaddr.sin_len = sizeof(struct sockaddr_in);
607 			ia->ia_broadaddr.sin_family = AF_INET;
608 		}
609 	}
610 
611 	if (ifp->if_flags & IFF_POINTOPOINT)
612 		ia->ia_dstaddr = *dstaddr;
613 
614 	if (vhid != 0) {
615 		error = (*carp_attach_p)(&ia->ia_ifa, vhid);
616 		if (error)
617 			return (error);
618 	}
619 
620 	/* if_addrhead is already referenced by ifa_alloc() */
621 	IF_ADDR_WLOCK(ifp);
622 	CK_STAILQ_INSERT_TAIL(&ifp->if_addrhead, ifa, ifa_link);
623 	IF_ADDR_WUNLOCK(ifp);
624 
625 	ifa_ref(ifa);			/* in_ifaddrhead */
626 	sx_assert(&in_control_sx, SA_XLOCKED);
627 	CK_STAILQ_INSERT_TAIL(&V_in_ifaddrhead, ia, ia_link);
628 	CK_LIST_INSERT_HEAD(INADDR_HASH(ia->ia_addr.sin_addr.s_addr), ia,
629 	    ia_hash);
630 
631 	/*
632 	 * Give the interface a chance to initialize
633 	 * if this is its first address,
634 	 * and to validate the address if necessary.
635 	 */
636 	if (ifp->if_ioctl != NULL) {
637 		error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia);
638 		if (error)
639 			goto fail1;
640 	}
641 
642 	/*
643 	 * Add route for the network.
644 	 */
645 	if (vhid == 0) {
646 		error = in_addprefix(ia);
647 		if (error)
648 			goto fail1;
649 	}
650 
651 	/*
652 	 * Add a loopback route to self.
653 	 */
654 	if (vhid == 0 && ia_need_loopback_route(ia)) {
655 		struct in_ifaddr *eia;
656 
657 		eia = in_localip_more(ia);
658 
659 		if (eia == NULL) {
660 			error = ifa_add_loopback_route((struct ifaddr *)ia,
661 			    (struct sockaddr *)&ia->ia_addr);
662 			if (error)
663 				goto fail2;
664 		} else
665 			ifa_free(&eia->ia_ifa);
666 	}
667 
668 	if (iaIsFirst && (ifp->if_flags & IFF_MULTICAST)) {
669 		struct in_addr allhosts_addr;
670 		struct in_ifinfo *ii;
671 
672 		ii = ((struct in_ifinfo *)ifp->if_afdata[AF_INET]);
673 		allhosts_addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);
674 
675 		error = in_joingroup(ifp, &allhosts_addr, NULL,
676 			&ii->ii_allhosts);
677 	}
678 
679 	/*
680 	 * Note: we don't need extra reference for ifa, since we called
681 	 * with sx lock held, and ifaddr can not be deleted in concurrent
682 	 * thread.
683 	 */
684 	EVENTHANDLER_INVOKE(ifaddr_event_ext, ifp, ifa, IFADDR_EVENT_ADD);
685 
686 	return (error);
687 
688 fail2:
689 	if (vhid == 0)
690 		(void )in_scrubprefix(ia, LLE_STATIC);
691 
692 fail1:
693 	if (ia->ia_ifa.ifa_carp)
694 		(*carp_detach_p)(&ia->ia_ifa, false);
695 
696 	IF_ADDR_WLOCK(ifp);
697 	CK_STAILQ_REMOVE(&ifp->if_addrhead, &ia->ia_ifa, ifaddr, ifa_link);
698 	IF_ADDR_WUNLOCK(ifp);
699 	ifa_free(&ia->ia_ifa);		/* if_addrhead */
700 
701 	sx_assert(&in_control_sx, SA_XLOCKED);
702 	CK_STAILQ_REMOVE(&V_in_ifaddrhead, ia, in_ifaddr, ia_link);
703 	CK_LIST_REMOVE(ia, ia_hash);
704 	ifa_free(&ia->ia_ifa);		/* in_ifaddrhead */
705 
706 	return (error);
707 }
708 
709 static int
in_difaddr_ioctl(u_long cmd,caddr_t data,struct ifnet * ifp,struct ucred * cred)710 in_difaddr_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp, struct ucred *cred)
711 {
712 	const struct ifreq *ifr = (struct ifreq *)data;
713 	const struct sockaddr_in *addr = (const struct sockaddr_in *)
714 	    &ifr->ifr_addr;
715 	struct ifaddr *ifa;
716 	struct in_ifaddr *ia;
717 	bool deleteAny, iaIsLast;
718 	int error;
719 
720 	if (cred != NULL) {
721 		error = priv_check_cred(cred, PRIV_NET_DELIFADDR);
722 		if (error)
723 			return (error);
724 	}
725 
726 	if (addr->sin_len != sizeof(struct sockaddr_in) ||
727 	    addr->sin_family != AF_INET)
728 		deleteAny = true;
729 	else
730 		deleteAny = false;
731 
732 	iaIsLast = true;
733 	ia = NULL;
734 	IF_ADDR_WLOCK(ifp);
735 	CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
736 		struct in_ifaddr *it;
737 
738 		if (ifa->ifa_addr->sa_family != AF_INET)
739 			continue;
740 
741 		it = (struct in_ifaddr *)ifa;
742 		if (deleteAny && ia == NULL && (cred == NULL ||
743 		    prison_check_ip4(cred, &it->ia_addr.sin_addr) == 0))
744 			ia = it;
745 
746 		if (it->ia_addr.sin_addr.s_addr == addr->sin_addr.s_addr &&
747 		    (cred == NULL || prison_check_ip4(cred,
748 		    &addr->sin_addr) == 0))
749 			ia = it;
750 
751 		if (it != ia)
752 			iaIsLast = false;
753 	}
754 
755 	if (ia == NULL) {
756 		IF_ADDR_WUNLOCK(ifp);
757 		return (EADDRNOTAVAIL);
758 	}
759 
760 	CK_STAILQ_REMOVE(&ifp->if_addrhead, &ia->ia_ifa, ifaddr, ifa_link);
761 	IF_ADDR_WUNLOCK(ifp);
762 	ifa_free(&ia->ia_ifa);		/* if_addrhead */
763 
764 	sx_assert(&in_control_sx, SA_XLOCKED);
765 	CK_STAILQ_REMOVE(&V_in_ifaddrhead, ia, in_ifaddr, ia_link);
766 	CK_LIST_REMOVE(ia, ia_hash);
767 
768 	/*
769 	 * in_scrubprefix() kills the interface route.
770 	 */
771 	in_scrubprefix(ia, LLE_STATIC);
772 
773 	/*
774 	 * in_ifadown gets rid of all the rest of
775 	 * the routes.  This is not quite the right
776 	 * thing to do, but at least if we are running
777 	 * a routing process they will come back.
778 	 */
779 	in_ifadown(&ia->ia_ifa, 1);
780 
781 	if (ia->ia_ifa.ifa_carp)
782 		(*carp_detach_p)(&ia->ia_ifa, cmd == SIOCAIFADDR);
783 
784 	/*
785 	 * If this is the last IPv4 address configured on this
786 	 * interface, leave the all-hosts group.
787 	 * No state-change report need be transmitted.
788 	 */
789 	if (iaIsLast && (ifp->if_flags & IFF_MULTICAST)) {
790 		struct in_ifinfo *ii;
791 
792 		ii = ((struct in_ifinfo *)ifp->if_afdata[AF_INET]);
793 		if (ii->ii_allhosts) {
794 			(void)in_leavegroup(ii->ii_allhosts, NULL);
795 			ii->ii_allhosts = NULL;
796 		}
797 	}
798 
799 	IF_ADDR_WLOCK(ifp);
800 	if (callout_stop(&ia->ia_garp_timer) == 1) {
801 		ifa_free(&ia->ia_ifa);
802 	}
803 	IF_ADDR_WUNLOCK(ifp);
804 
805 	EVENTHANDLER_INVOKE(ifaddr_event_ext, ifp, &ia->ia_ifa,
806 	    IFADDR_EVENT_DEL);
807 	ifa_free(&ia->ia_ifa);		/* in_ifaddrhead */
808 
809 	return (0);
810 }
811 
812 static int
in_gifaddr_ioctl(u_long cmd,caddr_t data,struct ifnet * ifp,struct ucred * cred)813 in_gifaddr_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp, struct ucred *cred)
814 {
815 	struct in_aliasreq *ifra = (struct in_aliasreq *)data;
816 	const struct sockaddr_in *addr = &ifra->ifra_addr;
817 	struct epoch_tracker et;
818 	struct ifaddr *ifa;
819 	struct in_ifaddr *ia;
820 
821 	/*
822 	 * ifra_addr must be present and be of INET family.
823 	 */
824 	if (addr->sin_len != sizeof(struct sockaddr_in) ||
825 	    addr->sin_family != AF_INET)
826 		return (EINVAL);
827 
828 	/*
829 	 * See whether address exist.
830 	 */
831 	ia = NULL;
832 	NET_EPOCH_ENTER(et);
833 	CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
834 		struct in_ifaddr *it;
835 
836 		if (ifa->ifa_addr->sa_family != AF_INET)
837 			continue;
838 
839 		it = (struct in_ifaddr *)ifa;
840 		if (it->ia_addr.sin_addr.s_addr == addr->sin_addr.s_addr &&
841 		    prison_check_ip4(cred, &addr->sin_addr) == 0) {
842 			ia = it;
843 			break;
844 		}
845 	}
846 	if (ia == NULL) {
847 		NET_EPOCH_EXIT(et);
848 		return (EADDRNOTAVAIL);
849 	}
850 
851 	ifra->ifra_mask = ia->ia_sockmask;
852 	if ((ifp->if_flags & IFF_POINTOPOINT) &&
853 	    ia->ia_dstaddr.sin_family == AF_INET)
854 		ifra->ifra_dstaddr = ia->ia_dstaddr;
855 	else if ((ifp->if_flags & IFF_BROADCAST) &&
856 	    ia->ia_broadaddr.sin_family == AF_INET)
857 		ifra->ifra_broadaddr = ia->ia_broadaddr;
858 	else
859 		memset(&ifra->ifra_broadaddr, 0,
860 		    sizeof(ifra->ifra_broadaddr));
861 
862 	NET_EPOCH_EXIT(et);
863 	return (0);
864 }
865 
866 static int
in_match_ifaddr(const struct rtentry * rt,const struct nhop_object * nh,void * arg)867 in_match_ifaddr(const struct rtentry *rt, const struct nhop_object *nh, void *arg)
868 {
869 
870 	if (nh->nh_ifa == (struct ifaddr *)arg)
871 		return (1);
872 
873 	return (0);
874 }
875 
876 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)877 in_handle_prefix_route(uint32_t fibnum, int cmd,
878     struct sockaddr_in *dst, struct sockaddr_in *netmask, struct ifaddr *ifa,
879     struct ifnet *ifp)
880 {
881 
882 	NET_EPOCH_ASSERT();
883 
884 	/* Prepare gateway */
885 	struct sockaddr_dl_short sdl = {
886 		.sdl_family = AF_LINK,
887 		.sdl_len = sizeof(struct sockaddr_dl_short),
888 		.sdl_type = ifa->ifa_ifp->if_type,
889 		.sdl_index = ifa->ifa_ifp->if_index,
890 	};
891 
892 	struct rt_addrinfo info = {
893 		.rti_ifa = ifa,
894 		.rti_ifp = ifp,
895 		.rti_flags = RTF_PINNED | ((netmask != NULL) ? 0 : RTF_HOST),
896 		.rti_info = {
897 			[RTAX_DST] = (struct sockaddr *)dst,
898 			[RTAX_NETMASK] = (struct sockaddr *)netmask,
899 			[RTAX_GATEWAY] = (struct sockaddr *)&sdl,
900 		},
901 		/* Ensure we delete the prefix IFF prefix ifa matches */
902 		.rti_filter = in_match_ifaddr,
903 		.rti_filterdata = ifa,
904 	};
905 
906 	return (rib_handle_ifaddr_info(fibnum, cmd, &info));
907 }
908 
909 /*
910  * Routing table interaction with interface addresses.
911  *
912  * In general, two types of routes needs to be installed:
913  * a) "interface" or "prefix" route, telling user that the addresses
914  *   behind the ifa prefix are reached directly.
915  * b) "loopback" route installed for the ifa address, telling user that
916  *   the address belongs to local system.
917  *
918  * Handling for (a) and (b) differs in multi-fib aspects, hence they
919  *  are implemented in different functions below.
920  *
921  * The cases above may intersect - /32 interface aliases results in
922  *  the same prefix produced by (a) and (b). This blurs the definition
923  *  of the "loopback" route and complicate interactions. The interaction
924  *  table is defined below. The case numbers are used in the multiple
925  *  functions below to refer to the particular test case.
926  *
927  * There can be multiple options:
928  * 1) Adding address with prefix on non-p2p/non-loopback interface.
929  *  Example: 192.0.2.1/24. Action:
930  *  * add "prefix" route towards 192.0.2.0/24 via @ia interface,
931  *    using @ia as an address source.
932  *  * add "loopback" route towards 192.0.2.1 via V_loif, saving
933  *   @ia ifp in the gateway and using @ia as an address source.
934  *
935  * 2) Adding address with /32 mask to non-p2p/non-loopback interface.
936  *  Example: 192.0.2.2/32. Action:
937  *  * add "prefix" host route via V_loif, using @ia as an address source.
938  *
939  * 3) Adding address with or without prefix to p2p interface.
940  *  Example: 10.0.0.1/24->10.0.0.2. Action:
941  *  * add "prefix" host route towards 10.0.0.2 via this interface, using @ia
942  *    as an address source. Note: no sense in installing full /24 as the interface
943  *    is point-to-point.
944  *  * add "loopback" route towards 10.0.9.1 via V_loif, saving
945  *   @ia ifp in the gateway and using @ia as an address source.
946  *
947  * 4) Adding address with or without prefix to loopback interface.
948  *  Example: 192.0.2.1/24. Action:
949  *  * add "prefix" host route via @ia interface, using @ia as an address source.
950  *    Note: Skip installing /24 prefix as it would introduce TTL loop
951  *    for the traffic destined to these addresses.
952  */
953 
954 /*
955  * Checks if @ia needs to install loopback route to @ia address via
956  *  ifa_maintain_loopback_route().
957  *
958  * Return true on success.
959  */
960 static bool
ia_need_loopback_route(const struct in_ifaddr * ia)961 ia_need_loopback_route(const struct in_ifaddr *ia)
962 {
963 	struct ifnet *ifp = ia->ia_ifp;
964 
965 	/* Case 4: Skip loopback interfaces */
966 	if ((ifp->if_flags & IFF_LOOPBACK) ||
967 	    (ia->ia_addr.sin_addr.s_addr == INADDR_ANY))
968 		return (false);
969 
970 	/* Clash avoidance: Skip p2p interfaces with both addresses are equal */
971 	if ((ifp->if_flags & IFF_POINTOPOINT) &&
972 	    ia->ia_dstaddr.sin_addr.s_addr == ia->ia_addr.sin_addr.s_addr)
973 		return (false);
974 
975 	/* Case 2: skip /32 prefixes */
976 	if (!(ifp->if_flags & IFF_POINTOPOINT) &&
977 	    (ia->ia_sockmask.sin_addr.s_addr == INADDR_BROADCAST))
978 		return (false);
979 
980 	return (true);
981 }
982 
983 /*
984  * Calculate "prefix" route corresponding to @ia.
985  */
986 static void
ia_getrtprefix(const struct in_ifaddr * ia,struct in_addr * prefix,struct in_addr * mask)987 ia_getrtprefix(const struct in_ifaddr *ia, struct in_addr *prefix, struct in_addr *mask)
988 {
989 
990 	if (ia->ia_ifp->if_flags & IFF_POINTOPOINT) {
991 		/* Case 3: return host route for dstaddr */
992 		*prefix = ia->ia_dstaddr.sin_addr;
993 		mask->s_addr = INADDR_BROADCAST;
994 	} else if (ia->ia_ifp->if_flags & IFF_LOOPBACK) {
995 		/* Case 4: return host route for ifaddr */
996 		*prefix = ia->ia_addr.sin_addr;
997 		mask->s_addr = INADDR_BROADCAST;
998 	} else {
999 		/* Cases 1,2: return actual ia prefix */
1000 		*prefix = ia->ia_addr.sin_addr;
1001 		*mask = ia->ia_sockmask.sin_addr;
1002 		prefix->s_addr &= mask->s_addr;
1003 	}
1004 }
1005 
1006 /*
1007  * Adds or delete interface "prefix" route corresponding to @ifa.
1008  *  Returns 0 on success or errno.
1009  */
1010 static int
in_handle_ifaddr_route(int cmd,struct in_ifaddr * ia)1011 in_handle_ifaddr_route(int cmd, struct in_ifaddr *ia)
1012 {
1013 	struct ifaddr *ifa = &ia->ia_ifa;
1014 	struct in_addr daddr, maddr;
1015 	struct sockaddr_in *pmask;
1016 	struct epoch_tracker et;
1017 	int error;
1018 
1019 	ia_getrtprefix(ia, &daddr, &maddr);
1020 
1021 	struct sockaddr_in mask = {
1022 		.sin_family = AF_INET,
1023 		.sin_len = sizeof(struct sockaddr_in),
1024 		.sin_addr = maddr,
1025 	};
1026 
1027 	pmask = (maddr.s_addr != INADDR_BROADCAST) ? &mask : NULL;
1028 
1029 	struct sockaddr_in dst = {
1030 		.sin_family = AF_INET,
1031 		.sin_len = sizeof(struct sockaddr_in),
1032 		.sin_addr.s_addr = daddr.s_addr & maddr.s_addr,
1033 	};
1034 
1035 	struct ifnet *ifp = ia->ia_ifp;
1036 
1037 	if ((maddr.s_addr == INADDR_BROADCAST) &&
1038 	    (!(ia->ia_ifp->if_flags & (IFF_POINTOPOINT|IFF_LOOPBACK)))) {
1039 		/* Case 2: host route on broadcast interface */
1040 		ifp = V_loif;
1041 	}
1042 
1043 	uint32_t fibnum = ifa->ifa_ifp->if_fib;
1044 	NET_EPOCH_ENTER(et);
1045 	error = in_handle_prefix_route(fibnum, cmd, &dst, pmask, ifa, ifp);
1046 	NET_EPOCH_EXIT(et);
1047 
1048 	return (error);
1049 }
1050 
1051 /*
1052  * Check if we have a route for the given prefix already.
1053  */
1054 static bool
in_hasrtprefix(struct in_ifaddr * target)1055 in_hasrtprefix(struct in_ifaddr *target)
1056 {
1057 	struct epoch_tracker et;
1058 	struct in_ifaddr *ia;
1059 	struct in_addr prefix, mask, p, m;
1060 	bool result = false;
1061 
1062 	ia_getrtprefix(target, &prefix, &mask);
1063 
1064 	/* Look for an existing address with the same prefix, mask, and fib */
1065 	NET_EPOCH_ENTER(et);
1066 	CK_STAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
1067 		ia_getrtprefix(ia, &p, &m);
1068 
1069 		if (prefix.s_addr != p.s_addr ||
1070 		    mask.s_addr != m.s_addr)
1071 			continue;
1072 
1073 		if (target->ia_ifp->if_fib != ia->ia_ifp->if_fib)
1074 			continue;
1075 
1076 		/*
1077 		 * If we got a matching prefix route inserted by other
1078 		 * interface address, we are done here.
1079 		 */
1080 		if (ia->ia_flags & IFA_ROUTE) {
1081 			result = true;
1082 			break;
1083 		}
1084 	}
1085 	NET_EPOCH_EXIT(et);
1086 
1087 	return (result);
1088 }
1089 
1090 int
in_addprefix(struct in_ifaddr * target)1091 in_addprefix(struct in_ifaddr *target)
1092 {
1093 	int error;
1094 
1095 	if (in_hasrtprefix(target)) {
1096 		if (V_nosameprefix)
1097 			return (EEXIST);
1098 		else {
1099 			rt_addrmsg(RTM_ADD, &target->ia_ifa,
1100 			    target->ia_ifp->if_fib);
1101 			return (0);
1102 		}
1103 	}
1104 
1105 	/*
1106 	 * No-one seem to have this prefix route, so we try to insert it.
1107 	 */
1108 	rt_addrmsg(RTM_ADD, &target->ia_ifa, target->ia_ifp->if_fib);
1109 	error = in_handle_ifaddr_route(RTM_ADD, target);
1110 	if (!error)
1111 		target->ia_flags |= IFA_ROUTE;
1112 	return (error);
1113 }
1114 
1115 /*
1116  * Removes either all lle entries for given @ia, or lle
1117  * corresponding to @ia address.
1118  */
1119 static void
in_scrubprefixlle(struct in_ifaddr * ia,int all,u_int flags)1120 in_scrubprefixlle(struct in_ifaddr *ia, int all, u_int flags)
1121 {
1122 	struct sockaddr_in addr, mask;
1123 	struct sockaddr *saddr, *smask;
1124 	struct ifnet *ifp;
1125 
1126 	saddr = (struct sockaddr *)&addr;
1127 	bzero(&addr, sizeof(addr));
1128 	addr.sin_len = sizeof(addr);
1129 	addr.sin_family = AF_INET;
1130 	smask = (struct sockaddr *)&mask;
1131 	bzero(&mask, sizeof(mask));
1132 	mask.sin_len = sizeof(mask);
1133 	mask.sin_family = AF_INET;
1134 	mask.sin_addr.s_addr = ia->ia_subnetmask;
1135 	ifp = ia->ia_ifp;
1136 
1137 	if (all) {
1138 		/*
1139 		 * Remove all L2 entries matching given prefix.
1140 		 * Convert address to host representation to avoid
1141 		 * doing this on every callback. ia_subnetmask is already
1142 		 * stored in host representation.
1143 		 */
1144 		addr.sin_addr.s_addr = ntohl(ia->ia_addr.sin_addr.s_addr);
1145 		lltable_prefix_free(AF_INET, saddr, smask, flags);
1146 	} else {
1147 		/* Remove interface address only */
1148 		addr.sin_addr.s_addr = ia->ia_addr.sin_addr.s_addr;
1149 		lltable_delete_addr(LLTABLE(ifp), LLE_IFADDR, saddr);
1150 	}
1151 }
1152 
1153 /*
1154  * If there is no other address in the system that can serve a route to the
1155  * same prefix, remove the route.  Hand over the route to the new address
1156  * otherwise.
1157  */
1158 int
in_scrubprefix(struct in_ifaddr * target,u_int flags)1159 in_scrubprefix(struct in_ifaddr *target, u_int flags)
1160 {
1161 	struct epoch_tracker et;
1162 	struct in_ifaddr *ia;
1163 	struct in_addr prefix, mask, p, m;
1164 	int error = 0;
1165 
1166 	/*
1167 	 * Remove the loopback route to the interface address.
1168 	 */
1169 	if (ia_need_loopback_route(target) && (flags & LLE_STATIC)) {
1170 		struct in_ifaddr *eia;
1171 
1172 		eia = in_localip_more(target);
1173 
1174 		if (eia != NULL) {
1175 			error = ifa_switch_loopback_route((struct ifaddr *)eia,
1176 			    (struct sockaddr *)&target->ia_addr);
1177 			ifa_free(&eia->ia_ifa);
1178 		} else {
1179 			error = ifa_del_loopback_route((struct ifaddr *)target,
1180 			    (struct sockaddr *)&target->ia_addr);
1181 		}
1182 	}
1183 
1184 	ia_getrtprefix(target, &prefix, &mask);
1185 
1186 	if ((target->ia_flags & IFA_ROUTE) == 0) {
1187 		rt_addrmsg(RTM_DELETE, &target->ia_ifa, target->ia_ifp->if_fib);
1188 
1189 		/*
1190 		 * Removing address from !IFF_UP interface or
1191 		 * prefix which exists on other interface (along with route).
1192 		 * No entries should exist here except target addr.
1193 		 * Given that, delete this entry only.
1194 		 */
1195 		in_scrubprefixlle(target, 0, flags);
1196 		return (0);
1197 	}
1198 
1199 	NET_EPOCH_ENTER(et);
1200 	CK_STAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
1201 		ia_getrtprefix(ia, &p, &m);
1202 
1203 		if (prefix.s_addr != p.s_addr ||
1204 		    mask.s_addr != m.s_addr)
1205 			continue;
1206 
1207 		if ((ia->ia_ifp->if_flags & IFF_UP) == 0)
1208 			continue;
1209 
1210 		/*
1211 		 * If we got a matching prefix address, move IFA_ROUTE and
1212 		 * the route itself to it.  Make sure that routing daemons
1213 		 * get a heads-up.
1214 		 */
1215 		if ((ia->ia_flags & IFA_ROUTE) == 0) {
1216 			ifa_ref(&ia->ia_ifa);
1217 			NET_EPOCH_EXIT(et);
1218 			error = in_handle_ifaddr_route(RTM_DELETE, target);
1219 			if (error == 0)
1220 				target->ia_flags &= ~IFA_ROUTE;
1221 			else
1222 				log(LOG_INFO, "in_scrubprefix: err=%d, old prefix delete failed\n",
1223 					error);
1224 			/* Scrub all entries IFF interface is different */
1225 			in_scrubprefixlle(target, target->ia_ifp != ia->ia_ifp,
1226 			    flags);
1227 			error = in_handle_ifaddr_route(RTM_ADD, ia);
1228 			if (error == 0)
1229 				ia->ia_flags |= IFA_ROUTE;
1230 			else
1231 				log(LOG_INFO, "in_scrubprefix: err=%d, new prefix add failed\n",
1232 					error);
1233 			ifa_free(&ia->ia_ifa);
1234 			return (error);
1235 		}
1236 	}
1237 	NET_EPOCH_EXIT(et);
1238 
1239 	/*
1240 	 * remove all L2 entries on the given prefix
1241 	 */
1242 	in_scrubprefixlle(target, 1, flags);
1243 
1244 	/*
1245 	 * As no-one seem to have this prefix, we can remove the route.
1246 	 */
1247 	rt_addrmsg(RTM_DELETE, &target->ia_ifa, target->ia_ifp->if_fib);
1248 	error = in_handle_ifaddr_route(RTM_DELETE, target);
1249 	if (error == 0)
1250 		target->ia_flags &= ~IFA_ROUTE;
1251 	else
1252 		log(LOG_INFO, "in_scrubprefix: err=%d, prefix delete failed\n", error);
1253 	return (error);
1254 }
1255 
1256 void
in_ifscrub_all(void)1257 in_ifscrub_all(void)
1258 {
1259 	struct ifnet *ifp;
1260 	struct ifaddr *ifa, *nifa;
1261 	struct ifreq ifr;
1262 
1263 	IFNET_RLOCK();
1264 	CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
1265 		/* Cannot lock here - lock recursion. */
1266 		/* NET_EPOCH_ENTER(et); */
1267 		CK_STAILQ_FOREACH_SAFE(ifa, &ifp->if_addrhead, ifa_link, nifa) {
1268 			if (ifa->ifa_addr->sa_family != AF_INET)
1269 				continue;
1270 
1271 			/*
1272 			 * This is ugly but the only way for legacy IP to
1273 			 * cleanly remove addresses and everything attached.
1274 			 */
1275 			bzero(&ifr, sizeof(ifr));
1276 			ifr.ifr_addr = *ifa->ifa_addr;
1277 			(void)in_control(NULL, SIOCDIFADDR, (caddr_t)&ifr,
1278 			    ifp, NULL);
1279 		}
1280 		/* NET_EPOCH_EXIT(et); */
1281 		in_purgemaddrs(ifp);
1282 		igmp_domifdetach(ifp);
1283 	}
1284 	IFNET_RUNLOCK();
1285 }
1286 
1287 bool
in_ifaddr_broadcast(struct in_addr in,struct in_ifaddr * ia)1288 in_ifaddr_broadcast(struct in_addr in, struct in_ifaddr *ia)
1289 {
1290 
1291 	return ((in.s_addr == ia->ia_broadaddr.sin_addr.s_addr ||
1292 	     /*
1293 	      * Optionally check for old-style (host 0) broadcast, but
1294 	      * taking into account that RFC 3021 obsoletes it.
1295 	      */
1296 	    __predict_false(V_broadcast_lowest &&
1297 	    ia->ia_subnetmask != IN_RFC3021_MASK &&
1298 	    ntohl(in.s_addr) == ia->ia_subnet)) &&
1299 	     /*
1300 	      * Check for an all one subnetmask. These
1301 	      * only exist when an interface gets a secondary
1302 	      * address.
1303 	      */
1304 	    ia->ia_subnetmask != (u_long)0xffffffff);
1305 }
1306 
1307 /*
1308  * Return true if the address might be a local broadcast address.
1309  */
1310 bool
in_ifnet_broadcast(struct in_addr in,struct ifnet * ifp)1311 in_ifnet_broadcast(struct in_addr in, struct ifnet *ifp)
1312 {
1313 	struct ifaddr *ifa;
1314 
1315 	NET_EPOCH_ASSERT();
1316 
1317 	if (in_broadcast(in))
1318 		return (true);
1319 	if ((ifp->if_flags & IFF_BROADCAST) == 0)
1320 		return (false);
1321 	/*
1322 	 * Look through the list of addresses for a match
1323 	 * with a broadcast address.
1324 	 */
1325 	CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
1326 		if (ifa->ifa_addr->sa_family == AF_INET &&
1327 		    in_ifaddr_broadcast(in, (struct in_ifaddr *)ifa))
1328 			return (true);
1329 	return (false);
1330 }
1331 
1332 /*
1333  * On interface removal, clean up IPv4 data structures hung off of the ifnet.
1334  */
1335 void
in_ifdetach(struct ifnet * ifp)1336 in_ifdetach(struct ifnet *ifp)
1337 {
1338 	IN_MULTI_LOCK();
1339 	in_pcbpurgeif0(&V_ripcbinfo, ifp);
1340 	in_pcbpurgeif0(&V_udbinfo, ifp);
1341 	in_pcbpurgeif0(&V_ulitecbinfo, ifp);
1342 	in_purgemaddrs(ifp);
1343 	IN_MULTI_UNLOCK();
1344 
1345 	/*
1346 	 * Make sure all multicast deletions invoking if_ioctl() are
1347 	 * completed before returning. Else we risk accessing a freed
1348 	 * ifnet structure pointer.
1349 	 */
1350 	inm_release_wait(NULL);
1351 }
1352 
1353 static void
in_ifnet_event(void * arg __unused,struct ifnet * ifp,int event)1354 in_ifnet_event(void *arg __unused, struct ifnet *ifp, int event)
1355 {
1356 	struct epoch_tracker et;
1357 	struct ifaddr *ifa;
1358 	struct in_ifaddr *ia;
1359 	int error;
1360 
1361 	NET_EPOCH_ENTER(et);
1362 	switch (event) {
1363 	case IFNET_EVENT_DOWN:
1364 		CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1365 			if (ifa->ifa_addr->sa_family != AF_INET)
1366 				continue;
1367 			ia = (struct in_ifaddr *)ifa;
1368 			if ((ia->ia_flags & IFA_ROUTE) == 0)
1369 				continue;
1370 			ifa_ref(ifa);
1371 			/*
1372 			 * in_scrubprefix() kills the interface route.
1373 			 */
1374 			in_scrubprefix(ia, 0);
1375 			/*
1376 			 * in_ifadown gets rid of all the rest of the
1377 			 * routes.  This is not quite the right thing
1378 			 * to do, but at least if we are running a
1379 			 * routing process they will come back.
1380 			 */
1381 			in_ifadown(ifa, 0);
1382 			ifa_free(ifa);
1383 		}
1384 		break;
1385 
1386 	case IFNET_EVENT_UP:
1387 		CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1388 			if (ifa->ifa_addr->sa_family != AF_INET)
1389 				continue;
1390 			ia = (struct in_ifaddr *)ifa;
1391 			if (ia->ia_flags & IFA_ROUTE)
1392 				continue;
1393 			ifa_ref(ifa);
1394 			error = ifa_del_loopback_route(ifa, ifa->ifa_addr);
1395 			rt_addrmsg(RTM_ADD, ifa, ifa->ifa_ifp->if_fib);
1396 			error = in_handle_ifaddr_route(RTM_ADD, ia);
1397 			if (error == 0)
1398 				ia->ia_flags |= IFA_ROUTE;
1399 			error = ifa_add_loopback_route(ifa, ifa->ifa_addr);
1400 			ifa_free(ifa);
1401 		}
1402 		break;
1403 	}
1404 	NET_EPOCH_EXIT(et);
1405 }
1406 EVENTHANDLER_DEFINE(ifnet_event, in_ifnet_event, NULL, EVENTHANDLER_PRI_ANY);
1407 
1408 /*
1409  * Delete all IPv4 multicast address records, and associated link-layer
1410  * multicast address records, associated with ifp.
1411  * XXX It looks like domifdetach runs AFTER the link layer cleanup.
1412  * XXX This should not race with ifma_protospec being set during
1413  * a new allocation, if it does, we have bigger problems.
1414  */
1415 static void
in_purgemaddrs(struct ifnet * ifp)1416 in_purgemaddrs(struct ifnet *ifp)
1417 {
1418 	struct epoch_tracker	 et;
1419 	struct in_multi_head purgeinms;
1420 	struct in_multi		*inm;
1421 	struct ifmultiaddr	*ifma;
1422 
1423 	SLIST_INIT(&purgeinms);
1424 	IN_MULTI_LIST_LOCK();
1425 
1426 	/*
1427 	 * Extract list of in_multi associated with the detaching ifp
1428 	 * which the PF_INET layer is about to release.
1429 	 * We need to do this as IF_ADDR_LOCK() may be re-acquired
1430 	 * by code further down.
1431 	 */
1432 	IF_ADDR_WLOCK(ifp);
1433 	NET_EPOCH_ENTER(et);
1434 	CK_STAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
1435 		inm = inm_ifmultiaddr_get_inm(ifma);
1436 		if (inm == NULL)
1437 			continue;
1438 		inm_rele_locked(&purgeinms, inm);
1439 	}
1440 	NET_EPOCH_EXIT(et);
1441 	IF_ADDR_WUNLOCK(ifp);
1442 
1443 	inm_release_list_deferred(&purgeinms);
1444 	igmp_ifdetach(ifp);
1445 	IN_MULTI_LIST_UNLOCK();
1446 }
1447 
1448 struct in_llentry {
1449 	struct llentry		base;
1450 };
1451 
1452 #define	IN_LLTBL_DEFAULT_HSIZE	32
1453 #define	IN_LLTBL_HASH(k, h) \
1454 	(((((((k >> 8) ^ k) >> 8) ^ k) >> 8) ^ k) & ((h) - 1))
1455 
1456 /*
1457  * Do actual deallocation of @lle.
1458  */
1459 static void
in_lltable_destroy_lle_unlocked(epoch_context_t ctx)1460 in_lltable_destroy_lle_unlocked(epoch_context_t ctx)
1461 {
1462 	struct llentry *lle;
1463 
1464 	lle = __containerof(ctx, struct llentry, lle_epoch_ctx);
1465 	LLE_LOCK_DESTROY(lle);
1466 	LLE_REQ_DESTROY(lle);
1467 	free(lle, M_LLTABLE);
1468 }
1469 
1470 /*
1471  * Called by LLE_FREE_LOCKED when number of references
1472  * drops to zero.
1473  */
1474 static void
in_lltable_destroy_lle(struct llentry * lle)1475 in_lltable_destroy_lle(struct llentry *lle)
1476 {
1477 
1478 	LLE_WUNLOCK(lle);
1479 	NET_EPOCH_CALL(in_lltable_destroy_lle_unlocked, &lle->lle_epoch_ctx);
1480 }
1481 
1482 static struct llentry *
in_lltable_new(struct in_addr addr4,u_int flags)1483 in_lltable_new(struct in_addr addr4, u_int flags)
1484 {
1485 	struct in_llentry *lle;
1486 
1487 	lle = malloc(sizeof(struct in_llentry), M_LLTABLE, M_NOWAIT | M_ZERO);
1488 	if (lle == NULL)		/* NB: caller generates msg */
1489 		return NULL;
1490 
1491 	/*
1492 	 * For IPv4 this will trigger "arpresolve" to generate
1493 	 * an ARP request.
1494 	 */
1495 	lle->base.la_expire = time_uptime; /* mark expired */
1496 	lle->base.r_l3addr.addr4 = addr4;
1497 	lle->base.lle_refcnt = 1;
1498 	lle->base.lle_free = in_lltable_destroy_lle;
1499 	LLE_LOCK_INIT(&lle->base);
1500 	LLE_REQ_INIT(&lle->base);
1501 	callout_init(&lle->base.lle_timer, 1);
1502 
1503 	return (&lle->base);
1504 }
1505 
1506 static int
in_lltable_match_prefix(const struct sockaddr * saddr,const struct sockaddr * smask,u_int flags,struct llentry * lle)1507 in_lltable_match_prefix(const struct sockaddr *saddr,
1508     const struct sockaddr *smask, u_int flags, struct llentry *lle)
1509 {
1510 	struct in_addr addr, mask, lle_addr;
1511 
1512 	addr = ((const struct sockaddr_in *)saddr)->sin_addr;
1513 	mask = ((const struct sockaddr_in *)smask)->sin_addr;
1514 	lle_addr.s_addr = ntohl(lle->r_l3addr.addr4.s_addr);
1515 
1516 	if (IN_ARE_MASKED_ADDR_EQUAL(lle_addr, addr, mask) == 0)
1517 		return (0);
1518 
1519 	if (lle->la_flags & LLE_IFADDR) {
1520 		/*
1521 		 * Delete LLE_IFADDR records IFF address & flag matches.
1522 		 * Note that addr is the interface address within prefix
1523 		 * being matched.
1524 		 * Note also we should handle 'ifdown' cases without removing
1525 		 * ifaddr macs.
1526 		 */
1527 		if (addr.s_addr == lle_addr.s_addr && (flags & LLE_STATIC) != 0)
1528 			return (1);
1529 		return (0);
1530 	}
1531 
1532 	/* flags & LLE_STATIC means deleting both dynamic and static entries */
1533 	if ((flags & LLE_STATIC) || !(lle->la_flags & LLE_STATIC))
1534 		return (1);
1535 
1536 	return (0);
1537 }
1538 
1539 static void
in_lltable_free_entry(struct lltable * llt,struct llentry * lle)1540 in_lltable_free_entry(struct lltable *llt, struct llentry *lle)
1541 {
1542 	size_t pkts_dropped;
1543 
1544 	LLE_WLOCK_ASSERT(lle);
1545 	KASSERT(llt != NULL, ("lltable is NULL"));
1546 
1547 	/* Unlink entry from table if not already */
1548 	if ((lle->la_flags & LLE_LINKED) != 0) {
1549 		IF_AFDATA_WLOCK_ASSERT(llt->llt_ifp);
1550 		lltable_unlink_entry(llt, lle);
1551 	}
1552 
1553 	/* Drop hold queue */
1554 	pkts_dropped = llentry_free(lle);
1555 	ARPSTAT_ADD(dropped, pkts_dropped);
1556 }
1557 
1558 static int
in_lltable_rtcheck(struct ifnet * ifp,u_int flags,const struct sockaddr * l3addr)1559 in_lltable_rtcheck(struct ifnet *ifp, u_int flags, const struct sockaddr *l3addr)
1560 {
1561 	struct nhop_object *nh;
1562 	struct in_addr addr;
1563 
1564 	KASSERT(l3addr->sa_family == AF_INET,
1565 	    ("sin_family %d", l3addr->sa_family));
1566 
1567 	addr = ((const struct sockaddr_in *)l3addr)->sin_addr;
1568 
1569 	nh = fib4_lookup(ifp->if_fib, addr, 0, NHR_NONE, 0);
1570 	if (nh == NULL)
1571 		return (EINVAL);
1572 
1573 	/*
1574 	 * If the gateway for an existing host route matches the target L3
1575 	 * address, which is a special route inserted by some implementation
1576 	 * such as MANET, and the interface is of the correct type, then
1577 	 * allow for ARP to proceed.
1578 	 */
1579 	if (nh->nh_flags & NHF_GATEWAY) {
1580 		if (!(nh->nh_flags & NHF_HOST) || nh->nh_ifp->if_type != IFT_ETHER ||
1581 		    (nh->nh_ifp->if_flags & (IFF_NOARP | IFF_STATICARP)) != 0 ||
1582 		    memcmp(nh->gw_sa.sa_data, l3addr->sa_data,
1583 		    sizeof(in_addr_t)) != 0) {
1584 			return (EINVAL);
1585 		}
1586 	}
1587 
1588 	/*
1589 	 * Make sure that at least the destination address is covered
1590 	 * by the route. This is for handling the case where 2 or more
1591 	 * interfaces have the same prefix. An incoming packet arrives
1592 	 * on one interface and the corresponding outgoing packet leaves
1593 	 * another interface.
1594 	 */
1595 	if ((nh->nh_ifp != ifp) && (nh->nh_flags & NHF_HOST) == 0) {
1596 		struct in_ifaddr *ia = (struct in_ifaddr *)ifaof_ifpforaddr(l3addr, ifp);
1597 		struct in_addr dst_addr, mask_addr;
1598 
1599 		if (ia == NULL)
1600 			return (EINVAL);
1601 
1602 		/*
1603 		 * ifaof_ifpforaddr() returns _best matching_ IFA.
1604 		 * It is possible that ifa prefix does not cover our address.
1605 		 * Explicitly verify and fail if that's the case.
1606 		 */
1607 		dst_addr = IA_SIN(ia)->sin_addr;
1608 		mask_addr.s_addr = htonl(ia->ia_subnetmask);
1609 
1610 		if (!IN_ARE_MASKED_ADDR_EQUAL(dst_addr, addr, mask_addr))
1611 			return (EINVAL);
1612 	}
1613 
1614 	return (0);
1615 }
1616 
1617 static inline uint32_t
in_lltable_hash_dst(const struct in_addr dst,uint32_t hsize)1618 in_lltable_hash_dst(const struct in_addr dst, uint32_t hsize)
1619 {
1620 
1621 	return (IN_LLTBL_HASH(dst.s_addr, hsize));
1622 }
1623 
1624 static uint32_t
in_lltable_hash(const struct llentry * lle,uint32_t hsize)1625 in_lltable_hash(const struct llentry *lle, uint32_t hsize)
1626 {
1627 
1628 	return (in_lltable_hash_dst(lle->r_l3addr.addr4, hsize));
1629 }
1630 
1631 static void
in_lltable_fill_sa_entry(const struct llentry * lle,struct sockaddr * sa)1632 in_lltable_fill_sa_entry(const struct llentry *lle, struct sockaddr *sa)
1633 {
1634 	struct sockaddr_in *sin;
1635 
1636 	sin = (struct sockaddr_in *)sa;
1637 	bzero(sin, sizeof(*sin));
1638 	sin->sin_family = AF_INET;
1639 	sin->sin_len = sizeof(*sin);
1640 	sin->sin_addr = lle->r_l3addr.addr4;
1641 }
1642 
1643 static inline struct llentry *
in_lltable_find_dst(struct lltable * llt,struct in_addr dst)1644 in_lltable_find_dst(struct lltable *llt, struct in_addr dst)
1645 {
1646 	struct llentry *lle;
1647 	struct llentries *lleh;
1648 	u_int hashidx;
1649 
1650 	hashidx = in_lltable_hash_dst(dst, llt->llt_hsize);
1651 	lleh = &llt->lle_head[hashidx];
1652 	CK_LIST_FOREACH(lle, lleh, lle_next) {
1653 		if (lle->la_flags & LLE_DELETED)
1654 			continue;
1655 		if (lle->r_l3addr.addr4.s_addr == dst.s_addr)
1656 			break;
1657 	}
1658 
1659 	return (lle);
1660 }
1661 
1662 static void
in_lltable_delete_entry(struct lltable * llt,struct llentry * lle)1663 in_lltable_delete_entry(struct lltable *llt, struct llentry *lle)
1664 {
1665 
1666 	lle->la_flags |= LLE_DELETED;
1667 	EVENTHANDLER_INVOKE(lle_event, lle, LLENTRY_DELETED);
1668 #ifdef DIAGNOSTIC
1669 	log(LOG_INFO, "ifaddr cache = %p is deleted\n", lle);
1670 #endif
1671 	llentry_free(lle);
1672 }
1673 
1674 static struct llentry *
in_lltable_alloc(struct lltable * llt,u_int flags,const struct sockaddr * l3addr)1675 in_lltable_alloc(struct lltable *llt, u_int flags, const struct sockaddr *l3addr)
1676 {
1677 	const struct sockaddr_in *sin = (const struct sockaddr_in *)l3addr;
1678 	struct ifnet *ifp = llt->llt_ifp;
1679 	struct llentry *lle;
1680 	char linkhdr[LLE_MAX_LINKHDR];
1681 	size_t linkhdrsize;
1682 	int lladdr_off;
1683 
1684 	KASSERT(l3addr->sa_family == AF_INET,
1685 	    ("sin_family %d", l3addr->sa_family));
1686 
1687 	/*
1688 	 * A route that covers the given address must have
1689 	 * been installed 1st because we are doing a resolution,
1690 	 * verify this.
1691 	 */
1692 	if (!(flags & LLE_IFADDR) &&
1693 	    in_lltable_rtcheck(ifp, flags, l3addr) != 0)
1694 		return (NULL);
1695 
1696 	lle = in_lltable_new(sin->sin_addr, flags);
1697 	if (lle == NULL) {
1698 		log(LOG_INFO, "lla_lookup: new lle malloc failed\n");
1699 		return (NULL);
1700 	}
1701 	lle->la_flags = flags;
1702 	if (flags & LLE_STATIC)
1703 		lle->r_flags |= RLLE_VALID;
1704 	if ((flags & LLE_IFADDR) == LLE_IFADDR) {
1705 		linkhdrsize = LLE_MAX_LINKHDR;
1706 		if (lltable_calc_llheader(ifp, AF_INET, IF_LLADDR(ifp),
1707 		    linkhdr, &linkhdrsize, &lladdr_off) != 0) {
1708 			in_lltable_free_entry(llt, lle);
1709 			return (NULL);
1710 		}
1711 		lltable_set_entry_addr(ifp, lle, linkhdr, linkhdrsize,
1712 		    lladdr_off);
1713 		lle->la_flags |= LLE_STATIC;
1714 		lle->r_flags |= (RLLE_VALID | RLLE_IFADDR);
1715 		lle->la_expire = 0;
1716 	}
1717 
1718 	return (lle);
1719 }
1720 
1721 /*
1722  * Return NULL if not found or marked for deletion.
1723  * If found return lle read locked.
1724  */
1725 static struct llentry *
in_lltable_lookup(struct lltable * llt,u_int flags,const struct sockaddr * l3addr)1726 in_lltable_lookup(struct lltable *llt, u_int flags, const struct sockaddr *l3addr)
1727 {
1728 	const struct sockaddr_in *sin = (const struct sockaddr_in *)l3addr;
1729 	struct llentry *lle;
1730 
1731 	IF_AFDATA_LOCK_ASSERT(llt->llt_ifp);
1732 	KASSERT(l3addr->sa_family == AF_INET,
1733 	    ("sin_family %d", l3addr->sa_family));
1734 	KASSERT((flags & (LLE_UNLOCKED | LLE_EXCLUSIVE)) !=
1735 	    (LLE_UNLOCKED | LLE_EXCLUSIVE),
1736 	    ("wrong lle request flags: %#x", flags));
1737 
1738 	lle = in_lltable_find_dst(llt, sin->sin_addr);
1739 	if (lle == NULL)
1740 		return (NULL);
1741 	if (flags & LLE_UNLOCKED)
1742 		return (lle);
1743 
1744 	if (flags & LLE_EXCLUSIVE)
1745 		LLE_WLOCK(lle);
1746 	else
1747 		LLE_RLOCK(lle);
1748 
1749 	/*
1750 	 * If the afdata lock is not held, the LLE may have been unlinked while
1751 	 * we were blocked on the LLE lock.  Check for this case.
1752 	 */
1753 	if (__predict_false((lle->la_flags & LLE_LINKED) == 0)) {
1754 		if (flags & LLE_EXCLUSIVE)
1755 			LLE_WUNLOCK(lle);
1756 		else
1757 			LLE_RUNLOCK(lle);
1758 		return (NULL);
1759 	}
1760 	return (lle);
1761 }
1762 
1763 static int
in_lltable_dump_entry(struct lltable * llt,struct llentry * lle,struct sysctl_req * wr)1764 in_lltable_dump_entry(struct lltable *llt, struct llentry *lle,
1765     struct sysctl_req *wr)
1766 {
1767 	struct ifnet *ifp = llt->llt_ifp;
1768 	/* XXX stack use */
1769 	struct {
1770 		struct rt_msghdr	rtm;
1771 		struct sockaddr_in	sin;
1772 		struct sockaddr_dl	sdl;
1773 	} arpc;
1774 	struct sockaddr_dl *sdl;
1775 	int error;
1776 
1777 	bzero(&arpc, sizeof(arpc));
1778 	/* skip deleted entries */
1779 	if ((lle->la_flags & LLE_DELETED) == LLE_DELETED)
1780 		return (0);
1781 	/* Skip if jailed and not a valid IP of the prison. */
1782 	lltable_fill_sa_entry(lle,(struct sockaddr *)&arpc.sin);
1783 	if (prison_if(wr->td->td_ucred, (struct sockaddr *)&arpc.sin) != 0)
1784 		return (0);
1785 	/*
1786 	 * produce a msg made of:
1787 	 *  struct rt_msghdr;
1788 	 *  struct sockaddr_in; (IPv4)
1789 	 *  struct sockaddr_dl;
1790 	 */
1791 	arpc.rtm.rtm_msglen = sizeof(arpc);
1792 	arpc.rtm.rtm_version = RTM_VERSION;
1793 	arpc.rtm.rtm_type = RTM_GET;
1794 	arpc.rtm.rtm_flags = RTF_UP;
1795 	arpc.rtm.rtm_addrs = RTA_DST | RTA_GATEWAY;
1796 
1797 	/* publish */
1798 	if (lle->la_flags & LLE_PUB)
1799 		arpc.rtm.rtm_flags |= RTF_ANNOUNCE;
1800 
1801 	sdl = &arpc.sdl;
1802 	sdl->sdl_family = AF_LINK;
1803 	sdl->sdl_len = sizeof(*sdl);
1804 	sdl->sdl_index = ifp->if_index;
1805 	sdl->sdl_type = ifp->if_type;
1806 	if ((lle->la_flags & LLE_VALID) == LLE_VALID) {
1807 		sdl->sdl_alen = ifp->if_addrlen;
1808 		bcopy(lle->ll_addr, LLADDR(sdl), ifp->if_addrlen);
1809 	} else {
1810 		sdl->sdl_alen = 0;
1811 		bzero(LLADDR(sdl), ifp->if_addrlen);
1812 	}
1813 
1814 	arpc.rtm.rtm_rmx.rmx_expire =
1815 	    lle->la_flags & LLE_STATIC ? 0 : lle->la_expire;
1816 	arpc.rtm.rtm_flags |= (RTF_HOST | RTF_LLDATA);
1817 	if (lle->la_flags & LLE_STATIC)
1818 		arpc.rtm.rtm_flags |= RTF_STATIC;
1819 	if (lle->la_flags & LLE_IFADDR)
1820 		arpc.rtm.rtm_flags |= RTF_PINNED;
1821 	arpc.rtm.rtm_index = ifp->if_index;
1822 	error = SYSCTL_OUT(wr, &arpc, sizeof(arpc));
1823 
1824 	return (error);
1825 }
1826 
1827 static void
in_lltable_post_resolved(struct lltable * llt,struct llentry * lle)1828 in_lltable_post_resolved(struct lltable *llt, struct llentry *lle)
1829 {
1830 	struct ifnet *ifp = llt->llt_ifp;
1831 
1832 	/* gratuitous ARP */
1833 	if ((lle->la_flags & LLE_PUB) != 0)
1834 		arprequest(ifp, &lle->r_l3addr.addr4, &lle->r_l3addr.addr4,
1835 		    lle->ll_addr);
1836 }
1837 
1838 static struct lltable *
in_lltattach(struct ifnet * ifp)1839 in_lltattach(struct ifnet *ifp)
1840 {
1841 	struct lltable *llt;
1842 
1843 	llt = lltable_allocate_htbl(IN_LLTBL_DEFAULT_HSIZE);
1844  	llt->llt_af = AF_INET;
1845  	llt->llt_ifp = ifp;
1846 
1847 	llt->llt_lookup = in_lltable_lookup;
1848 	llt->llt_alloc_entry = in_lltable_alloc;
1849 	llt->llt_delete_entry = in_lltable_delete_entry;
1850 	llt->llt_dump_entry = in_lltable_dump_entry;
1851 	llt->llt_hash = in_lltable_hash;
1852 	llt->llt_fill_sa_entry = in_lltable_fill_sa_entry;
1853 	llt->llt_free_entry = in_lltable_free_entry;
1854 	llt->llt_match_prefix = in_lltable_match_prefix;
1855 	llt->llt_mark_used = llentry_mark_used;
1856 	llt->llt_post_resolved = in_lltable_post_resolved;
1857  	lltable_link(llt);
1858 
1859 	return (llt);
1860 }
1861 
1862 struct lltable *
in_lltable_get(struct ifnet * ifp)1863 in_lltable_get(struct ifnet *ifp)
1864 {
1865 	struct lltable *llt = NULL;
1866 
1867 	void *afdata_ptr = ifp->if_afdata[AF_INET];
1868 	if (afdata_ptr != NULL)
1869 		llt = ((struct in_ifinfo *)afdata_ptr)->ii_llt;
1870 	return (llt);
1871 }
1872 
1873 void *
in_domifattach(struct ifnet * ifp)1874 in_domifattach(struct ifnet *ifp)
1875 {
1876 	struct in_ifinfo *ii;
1877 
1878 	ii = malloc(sizeof(struct in_ifinfo), M_IFADDR, M_WAITOK|M_ZERO);
1879 
1880 	ii->ii_llt = in_lltattach(ifp);
1881 	ii->ii_igmp = igmp_domifattach(ifp);
1882 
1883 	return (ii);
1884 }
1885 
1886 void
in_domifdetach(struct ifnet * ifp,void * aux)1887 in_domifdetach(struct ifnet *ifp, void *aux)
1888 {
1889 	struct in_ifinfo *ii = (struct in_ifinfo *)aux;
1890 
1891 	MPASS(ifp->if_afdata[AF_INET] == NULL);
1892 
1893 	igmp_domifdetach(ifp);
1894 	lltable_free(ii->ii_llt);
1895 	free(ii, M_IFADDR);
1896 }
1897