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in.c revision 1.62
      1 /*	$NetBSD: in.c,v 1.62 2000/08/02 15:03:02 itojun Exp $	*/
      2 
      3 /*
      4  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. Neither the name of the project nor the names of its contributors
     16  *    may be used to endorse or promote products derived from this software
     17  *    without specific prior written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
     20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
     23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  * SUCH DAMAGE.
     30  */
     31 
     32 /*-
     33  * Copyright (c) 1998 The NetBSD Foundation, Inc.
     34  * All rights reserved.
     35  *
     36  * This code is derived from software contributed to The NetBSD Foundation
     37  * by Public Access Networks Corporation ("Panix").  It was developed under
     38  * contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon.
     39  *
     40  * Redistribution and use in source and binary forms, with or without
     41  * modification, are permitted provided that the following conditions
     42  * are met:
     43  * 1. Redistributions of source code must retain the above copyright
     44  *    notice, this list of conditions and the following disclaimer.
     45  * 2. Redistributions in binary form must reproduce the above copyright
     46  *    notice, this list of conditions and the following disclaimer in the
     47  *    documentation and/or other materials provided with the distribution.
     48  * 3. All advertising materials mentioning features or use of this software
     49  *    must display the following acknowledgement:
     50  *	This product includes software developed by the NetBSD
     51  *	Foundation, Inc. and its contributors.
     52  * 4. Neither the name of The NetBSD Foundation nor the names of its
     53  *    contributors may be used to endorse or promote products derived
     54  *    from this software without specific prior written permission.
     55  *
     56  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     57  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     58  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     59  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     60  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     61  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     62  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     63  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     64  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     65  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     66  * POSSIBILITY OF SUCH DAMAGE.
     67  */
     68 
     69 /*
     70  * Copyright (c) 1982, 1986, 1991, 1993
     71  *	The Regents of the University of California.  All rights reserved.
     72  *
     73  * Redistribution and use in source and binary forms, with or without
     74  * modification, are permitted provided that the following conditions
     75  * are met:
     76  * 1. Redistributions of source code must retain the above copyright
     77  *    notice, this list of conditions and the following disclaimer.
     78  * 2. Redistributions in binary form must reproduce the above copyright
     79  *    notice, this list of conditions and the following disclaimer in the
     80  *    documentation and/or other materials provided with the distribution.
     81  * 3. All advertising materials mentioning features or use of this software
     82  *    must display the following acknowledgement:
     83  *	This product includes software developed by the University of
     84  *	California, Berkeley and its contributors.
     85  * 4. Neither the name of the University nor the names of its contributors
     86  *    may be used to endorse or promote products derived from this software
     87  *    without specific prior written permission.
     88  *
     89  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     90  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     91  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     92  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     93  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     94  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     95  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     96  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     97  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     98  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     99  * SUCH DAMAGE.
    100  *
    101  *	@(#)in.c	8.4 (Berkeley) 1/9/95
    102  */
    103 
    104 #include "opt_inet.h"
    105 #include "opt_inet_conf.h"
    106 #include "opt_mrouting.h"
    107 
    108 #include <sys/param.h>
    109 #include <sys/ioctl.h>
    110 #include <sys/errno.h>
    111 #include <sys/malloc.h>
    112 #include <sys/socket.h>
    113 #include <sys/socketvar.h>
    114 #include <sys/systm.h>
    115 #include <sys/proc.h>
    116 
    117 #include <net/if.h>
    118 #include <net/if_types.h>
    119 #include <net/route.h>
    120 #include "gif.h"
    121 #if NGIF > 0
    122 #include <net/if_gif.h>
    123 #endif
    124 
    125 #include <net/if_ether.h>
    126 
    127 #include <netinet/in_systm.h>
    128 #include <netinet/in.h>
    129 #include <netinet/in_var.h>
    130 #include <netinet/if_inarp.h>
    131 #include <netinet/ip_mroute.h>
    132 #include <netinet/igmp_var.h>
    133 
    134 #ifdef INET
    135 
    136 static int in_mask2len __P((struct in_addr *));
    137 static void in_len2mask __P((struct in_addr *, int));
    138 static int in_lifaddr_ioctl __P((struct socket *, u_long, caddr_t,
    139 	struct ifnet *, struct proc *));
    140 
    141 #ifndef SUBNETSARELOCAL
    142 #define	SUBNETSARELOCAL	1
    143 #endif
    144 
    145 #ifndef HOSTZEROBROADCAST
    146 #define HOSTZEROBROADCAST 1
    147 #endif
    148 
    149 int subnetsarelocal = SUBNETSARELOCAL;
    150 int hostzeroisbroadcast = HOSTZEROBROADCAST;
    151 
    152 /*
    153  * Return 1 if an internet address is for a ``local'' host
    154  * (one to which we have a connection).  If subnetsarelocal
    155  * is true, this includes other subnets of the local net.
    156  * Otherwise, it includes only the directly-connected (sub)nets.
    157  */
    158 int
    159 in_localaddr(in)
    160 	struct in_addr in;
    161 {
    162 	struct in_ifaddr *ia;
    163 
    164 	if (subnetsarelocal) {
    165 		for (ia = in_ifaddr.tqh_first; ia != 0; ia = ia->ia_list.tqe_next)
    166 			if ((in.s_addr & ia->ia_netmask) == ia->ia_net)
    167 				return (1);
    168 	} else {
    169 		for (ia = in_ifaddr.tqh_first; ia != 0; ia = ia->ia_list.tqe_next)
    170 			if ((in.s_addr & ia->ia_subnetmask) == ia->ia_subnet)
    171 				return (1);
    172 	}
    173 	return (0);
    174 }
    175 
    176 /*
    177  * Determine whether an IP address is in a reserved set of addresses
    178  * that may not be forwarded, or whether datagrams to that destination
    179  * may be forwarded.
    180  */
    181 int
    182 in_canforward(in)
    183 	struct in_addr in;
    184 {
    185 	u_int32_t net;
    186 
    187 	if (IN_EXPERIMENTAL(in.s_addr) || IN_MULTICAST(in.s_addr))
    188 		return (0);
    189 	if (IN_CLASSA(in.s_addr)) {
    190 		net = in.s_addr & IN_CLASSA_NET;
    191 		if (net == 0 || net == htonl(IN_LOOPBACKNET << IN_CLASSA_NSHIFT))
    192 			return (0);
    193 	}
    194 	return (1);
    195 }
    196 
    197 /*
    198  * Trim a mask in a sockaddr
    199  */
    200 void
    201 in_socktrim(ap)
    202 	struct sockaddr_in *ap;
    203 {
    204 	char *cplim = (char *) &ap->sin_addr;
    205 	char *cp = (char *) (&ap->sin_addr + 1);
    206 
    207 	ap->sin_len = 0;
    208 	while (--cp >= cplim)
    209 		if (*cp) {
    210 			(ap)->sin_len = cp - (char *) (ap) + 1;
    211 			break;
    212 		}
    213 }
    214 
    215 /*
    216  *  Routine to take an Internet address and convert into a
    217  *  "dotted quad" representation for printing.
    218  */
    219 const char *
    220 in_fmtaddr(addr)
    221 	struct in_addr addr;
    222 {
    223 	static char buf[sizeof("123.456.789.123")];
    224 
    225 	addr.s_addr = ntohl(addr.s_addr);
    226 
    227 	sprintf(buf, "%d.%d.%d.%d",
    228 		(addr.s_addr >> 24) & 0xFF,
    229 		(addr.s_addr >> 16) & 0xFF,
    230 		(addr.s_addr >>  8) & 0xFF,
    231 		(addr.s_addr >>  0) & 0xFF);
    232 	return buf;
    233 }
    234 
    235 /*
    236  * Maintain the "in_maxmtu" variable, which is the largest
    237  * mtu for non-local interfaces with AF_INET addresses assigned
    238  * to them that are up.
    239  */
    240 unsigned long in_maxmtu;
    241 
    242 void
    243 in_setmaxmtu()
    244 {
    245 	struct in_ifaddr *ia;
    246 	struct ifnet *ifp;
    247 	unsigned long maxmtu = 0;
    248 
    249 	for (ia = in_ifaddr.tqh_first; ia != 0; ia = ia->ia_list.tqe_next) {
    250 		if ((ifp = ia->ia_ifp) == 0)
    251 			continue;
    252 		if ((ifp->if_flags & (IFF_UP|IFF_LOOPBACK)) != IFF_UP)
    253 			continue;
    254 		if (ifp->if_mtu > maxmtu)
    255 			maxmtu = ifp->if_mtu;
    256 	}
    257 	if (maxmtu)
    258 		in_maxmtu = maxmtu;
    259 }
    260 
    261 static int
    262 in_mask2len(mask)
    263 	struct in_addr *mask;
    264 {
    265 	int x, y;
    266 	u_char *p;
    267 
    268 	p = (u_char *)mask;
    269 	for (x = 0; x < sizeof(*mask); x++) {
    270 		if (p[x] != 0xff)
    271 			break;
    272 	}
    273 	y = 0;
    274 	if (x < sizeof(*mask)) {
    275 		for (y = 0; y < 8; y++) {
    276 			if ((p[x] & (0x80 >> y)) == 0)
    277 				break;
    278 		}
    279 	}
    280 	return x * 8 + y;
    281 }
    282 
    283 static void
    284 in_len2mask(mask, len)
    285 	struct in_addr *mask;
    286 	int len;
    287 {
    288 	int i;
    289 	u_char *p;
    290 
    291 	p = (u_char *)mask;
    292 	bzero(mask, sizeof(*mask));
    293 	for (i = 0; i < len / 8; i++)
    294 		p[i] = 0xff;
    295 	if (len % 8)
    296 		p[i] = (0xff00 >> (len % 8)) & 0xff;
    297 }
    298 
    299 /*
    300  * Generic internet control operations (ioctl's).
    301  * Ifp is 0 if not an interface-specific ioctl.
    302  */
    303 /* ARGSUSED */
    304 int
    305 in_control(so, cmd, data, ifp, p)
    306 	struct socket *so;
    307 	u_long cmd;
    308 	caddr_t data;
    309 	struct ifnet *ifp;
    310 	struct proc *p;
    311 {
    312 	struct ifreq *ifr = (struct ifreq *)data;
    313 	struct in_ifaddr *ia = 0;
    314 	struct in_aliasreq *ifra = (struct in_aliasreq *)data;
    315 	struct sockaddr_in oldaddr;
    316 	int error, hostIsNew, maskIsNew;
    317 	int newifaddr;
    318 
    319 #if NGIF > 0
    320 	if (ifp && ifp->if_type == IFT_GIF) {
    321 		switch (cmd) {
    322 		case SIOCSIFPHYADDR:
    323 			if (p == 0 || (error = suser(p->p_ucred, &p->p_acflag)))
    324 				return(EPERM);
    325 		case SIOCGIFPSRCADDR:
    326 		case SIOCGIFPDSTADDR:
    327 			return gif_ioctl(ifp, cmd, data);
    328 		}
    329 	}
    330 #endif
    331 
    332 	switch (cmd) {
    333 	case SIOCALIFADDR:
    334 	case SIOCDLIFADDR:
    335 		if (p == 0 || (error = suser(p->p_ucred, &p->p_acflag)))
    336 			return(EPERM);
    337 		/*fall through*/
    338 	case SIOCGLIFADDR:
    339 		if (!ifp)
    340 			return EINVAL;
    341 		return in_lifaddr_ioctl(so, cmd, data, ifp, p);
    342 	}
    343 
    344 	/*
    345 	 * Find address for this interface, if it exists.
    346 	 */
    347 	if (ifp)
    348 		IFP_TO_IA(ifp, ia);
    349 
    350 	switch (cmd) {
    351 
    352 	case SIOCAIFADDR:
    353 	case SIOCDIFADDR:
    354 	case SIOCGIFALIAS:
    355 		if (ifra->ifra_addr.sin_family == AF_INET)
    356 			for (ia = IN_IFADDR_HASH(ifra->ifra_addr.sin_addr.s_addr).lh_first;
    357 			    ia != 0; ia = ia->ia_hash.le_next) {
    358 				if (ia->ia_ifp == ifp  &&
    359 				    in_hosteq(ia->ia_addr.sin_addr,
    360 				    ifra->ifra_addr.sin_addr))
    361 					break;
    362 			}
    363 		if (cmd == SIOCDIFADDR) {
    364 			if (ia == 0)
    365 				return (EADDRNOTAVAIL);
    366 #if 1 /*def COMPAT_43*/
    367 			if (ifra->ifra_addr.sin_family == AF_UNSPEC)
    368 				ifra->ifra_addr.sin_family = AF_INET;
    369 #endif
    370 		}
    371 		/* FALLTHROUGH */
    372 	case SIOCSIFADDR:
    373 	case SIOCSIFDSTADDR:
    374 		if (ifra->ifra_addr.sin_family != AF_INET)
    375 			return (EAFNOSUPPORT);
    376 		/* FALLTHROUGH */
    377 	case SIOCSIFNETMASK:
    378 		if (ifp == 0)
    379 			panic("in_control");
    380 
    381 		if (cmd == SIOCGIFALIAS)
    382 			break;
    383 
    384 		if (p == 0 || (error = suser(p->p_ucred, &p->p_acflag)))
    385 			return (EPERM);
    386 
    387 		if (ia == 0) {
    388 			MALLOC(ia, struct in_ifaddr *, sizeof(*ia),
    389 			       M_IFADDR, M_WAITOK);
    390 			if (ia == 0)
    391 				return (ENOBUFS);
    392 			bzero((caddr_t)ia, sizeof *ia);
    393 			TAILQ_INSERT_TAIL(&in_ifaddr, ia, ia_list);
    394 			IFAREF(&ia->ia_ifa);
    395 			TAILQ_INSERT_TAIL(&ifp->if_addrlist, &ia->ia_ifa,
    396 			    ifa_list);
    397 			IFAREF(&ia->ia_ifa);
    398 			ia->ia_ifa.ifa_addr = sintosa(&ia->ia_addr);
    399 			ia->ia_ifa.ifa_dstaddr = sintosa(&ia->ia_dstaddr);
    400 			ia->ia_ifa.ifa_netmask = sintosa(&ia->ia_sockmask);
    401 			ia->ia_sockmask.sin_len = 8;
    402 			if (ifp->if_flags & IFF_BROADCAST) {
    403 				ia->ia_broadaddr.sin_len = sizeof(ia->ia_addr);
    404 				ia->ia_broadaddr.sin_family = AF_INET;
    405 			}
    406 			ia->ia_ifp = ifp;
    407 			LIST_INIT(&ia->ia_multiaddrs);
    408 			newifaddr = 1;
    409 		} else
    410 			newifaddr = 0;
    411 		break;
    412 
    413 	case SIOCSIFBRDADDR:
    414 		if (p == 0 || (error = suser(p->p_ucred, &p->p_acflag)))
    415 			return (EPERM);
    416 		/* FALLTHROUGH */
    417 
    418 	case SIOCGIFADDR:
    419 	case SIOCGIFNETMASK:
    420 	case SIOCGIFDSTADDR:
    421 	case SIOCGIFBRDADDR:
    422 		if (ia == 0)
    423 			return (EADDRNOTAVAIL);
    424 		break;
    425 	}
    426 	switch (cmd) {
    427 
    428 	case SIOCGIFADDR:
    429 		*satosin(&ifr->ifr_addr) = ia->ia_addr;
    430 		break;
    431 
    432 	case SIOCGIFBRDADDR:
    433 		if ((ifp->if_flags & IFF_BROADCAST) == 0)
    434 			return (EINVAL);
    435 		*satosin(&ifr->ifr_dstaddr) = ia->ia_broadaddr;
    436 		break;
    437 
    438 	case SIOCGIFDSTADDR:
    439 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
    440 			return (EINVAL);
    441 		*satosin(&ifr->ifr_dstaddr) = ia->ia_dstaddr;
    442 		break;
    443 
    444 	case SIOCGIFNETMASK:
    445 		*satosin(&ifr->ifr_addr) = ia->ia_sockmask;
    446 		break;
    447 
    448 	case SIOCSIFDSTADDR:
    449 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
    450 			return (EINVAL);
    451 		oldaddr = ia->ia_dstaddr;
    452 		ia->ia_dstaddr = *satosin(&ifr->ifr_dstaddr);
    453 		if (ifp->if_ioctl && (error = (*ifp->if_ioctl)
    454 					(ifp, SIOCSIFDSTADDR, (caddr_t)ia))) {
    455 			ia->ia_dstaddr = oldaddr;
    456 			return (error);
    457 		}
    458 		if (ia->ia_flags & IFA_ROUTE) {
    459 			ia->ia_ifa.ifa_dstaddr = sintosa(&oldaddr);
    460 			rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST);
    461 			ia->ia_ifa.ifa_dstaddr = sintosa(&ia->ia_dstaddr);
    462 			rtinit(&(ia->ia_ifa), (int)RTM_ADD, RTF_HOST|RTF_UP);
    463 		}
    464 		break;
    465 
    466 	case SIOCSIFBRDADDR:
    467 		if ((ifp->if_flags & IFF_BROADCAST) == 0)
    468 			return (EINVAL);
    469 		ia->ia_broadaddr = *satosin(&ifr->ifr_broadaddr);
    470 		break;
    471 
    472 	case SIOCSIFADDR:
    473 		error = in_ifinit(ifp, ia, satosin(&ifr->ifr_addr), 1);
    474 #if 0
    475 		/*
    476 		 * the code chokes if we are to assign multiple addresses with
    477 		 * the same address prefix (rtinit() will return EEXIST, which
    478 		 * is not fatal actually).  we will get memory leak if we
    479 		 * don't do it.
    480 		 * -> we may want to hide EEXIST from rtinit().
    481 		 */
    482   undo:
    483 		if (error && newifaddr) {
    484 			TAILQ_REMOVE(&ifp->if_addrlist, &ia->ia_ifa, ifa_list);
    485 			IFAFREE(&ia->ia_ifa);
    486 			TAILQ_REMOVE(&in_ifaddr, ia, ia_list);
    487 			IFAFREE(&ia->ia_ifa);
    488 		}
    489 #endif
    490 		return error;
    491 
    492 	case SIOCSIFNETMASK:
    493 		ia->ia_subnetmask = ia->ia_sockmask.sin_addr.s_addr =
    494 		    ifra->ifra_addr.sin_addr.s_addr;
    495 		break;
    496 
    497 	case SIOCAIFADDR:
    498 		maskIsNew = 0;
    499 		hostIsNew = 1;
    500 		error = 0;
    501 		if (ia->ia_addr.sin_family == AF_INET) {
    502 			if (ifra->ifra_addr.sin_len == 0) {
    503 				ifra->ifra_addr = ia->ia_addr;
    504 				hostIsNew = 0;
    505 			} else if (in_hosteq(ia->ia_addr.sin_addr, ifra->ifra_addr.sin_addr))
    506 				hostIsNew = 0;
    507 		}
    508 		if (ifra->ifra_mask.sin_len) {
    509 			in_ifscrub(ifp, ia);
    510 			ia->ia_sockmask = ifra->ifra_mask;
    511 			ia->ia_subnetmask = ia->ia_sockmask.sin_addr.s_addr;
    512 			maskIsNew = 1;
    513 		}
    514 		if ((ifp->if_flags & IFF_POINTOPOINT) &&
    515 		    (ifra->ifra_dstaddr.sin_family == AF_INET)) {
    516 			in_ifscrub(ifp, ia);
    517 			ia->ia_dstaddr = ifra->ifra_dstaddr;
    518 			maskIsNew  = 1; /* We lie; but the effect's the same */
    519 		}
    520 		if (ifra->ifra_addr.sin_family == AF_INET &&
    521 		    (hostIsNew || maskIsNew)) {
    522 			error = in_ifinit(ifp, ia, &ifra->ifra_addr, 0);
    523 #if 0
    524 			if (error)
    525 				goto undo;
    526 #endif
    527 		}
    528 		if ((ifp->if_flags & IFF_BROADCAST) &&
    529 		    (ifra->ifra_broadaddr.sin_family == AF_INET))
    530 			ia->ia_broadaddr = ifra->ifra_broadaddr;
    531 		return (error);
    532 
    533 	case SIOCGIFALIAS:
    534 		ifra->ifra_mask = ia->ia_sockmask;
    535 		if ((ifp->if_flags & IFF_POINTOPOINT) &&
    536 		    (ia->ia_dstaddr.sin_family == AF_INET))
    537 			ifra->ifra_dstaddr = ia->ia_dstaddr;
    538 		else if ((ifp->if_flags & IFF_BROADCAST) &&
    539 		    (ia->ia_broadaddr.sin_family == AF_INET))
    540 			ifra->ifra_broadaddr = ia->ia_broadaddr;
    541 		else
    542 			bzero(&ifra->ifra_broadaddr,
    543 			      sizeof(ifra->ifra_broadaddr));
    544 		return 0;
    545 
    546 	case SIOCDIFADDR:
    547 		in_purgeaddr(&ia->ia_ifa, ifp);
    548 		break;
    549 
    550 #ifdef MROUTING
    551 	case SIOCGETVIFCNT:
    552 	case SIOCGETSGCNT:
    553 		return (mrt_ioctl(so, cmd, data));
    554 #endif /* MROUTING */
    555 
    556 	default:
    557 		if (ifp == 0 || ifp->if_ioctl == 0)
    558 			return (EOPNOTSUPP);
    559 		error = (*ifp->if_ioctl)(ifp, cmd, data);
    560 		in_setmaxmtu();
    561 		return(error);
    562 	}
    563 	return (0);
    564 }
    565 
    566 void
    567 in_purgeaddr(ifa, ifp)
    568 	struct ifaddr *ifa;
    569 	struct ifnet *ifp;
    570 {
    571 	struct in_ifaddr *ia = (void *) ifa;
    572 
    573 	in_ifscrub(ifp, ia);
    574 	LIST_REMOVE(ia, ia_hash);
    575 	TAILQ_REMOVE(&ifp->if_addrlist, &ia->ia_ifa, ifa_list);
    576 	IFAFREE(&ia->ia_ifa);
    577 	TAILQ_REMOVE(&in_ifaddr, ia, ia_list);
    578 	IFAFREE(&ia->ia_ifa);
    579 	in_setmaxmtu();
    580 }
    581 
    582 void
    583 in_purgeif(ifp)
    584 	struct ifnet *ifp;
    585 {
    586 	struct ifaddr *ifa, *nifa;
    587 
    588 	for (ifa = TAILQ_FIRST(&ifp->if_addrlist); ifa != NULL; ifa = nifa) {
    589 		nifa = TAILQ_NEXT(ifa, ifa_list);
    590 		if (ifa->ifa_addr->sa_family != AF_INET)
    591 			continue;
    592 		in_purgeaddr(ifa, ifp);
    593 	}
    594 }
    595 
    596 /*
    597  * SIOC[GAD]LIFADDR.
    598  *	SIOCGLIFADDR: get first address. (???)
    599  *	SIOCGLIFADDR with IFLR_PREFIX:
    600  *		get first address that matches the specified prefix.
    601  *	SIOCALIFADDR: add the specified address.
    602  *	SIOCALIFADDR with IFLR_PREFIX:
    603  *		EINVAL since we can't deduce hostid part of the address.
    604  *	SIOCDLIFADDR: delete the specified address.
    605  *	SIOCDLIFADDR with IFLR_PREFIX:
    606  *		delete the first address that matches the specified prefix.
    607  * return values:
    608  *	EINVAL on invalid parameters
    609  *	EADDRNOTAVAIL on prefix match failed/specified address not found
    610  *	other values may be returned from in_ioctl()
    611  */
    612 static int
    613 in_lifaddr_ioctl(so, cmd, data, ifp, p)
    614 	struct socket *so;
    615 	u_long cmd;
    616 	caddr_t	data;
    617 	struct ifnet *ifp;
    618 	struct proc *p;
    619 {
    620 	struct if_laddrreq *iflr = (struct if_laddrreq *)data;
    621 	struct ifaddr *ifa;
    622 	struct sockaddr *sa;
    623 
    624 	/* sanity checks */
    625 	if (!data || !ifp) {
    626 		panic("invalid argument to in_lifaddr_ioctl");
    627 		/*NOTRECHED*/
    628 	}
    629 
    630 	switch (cmd) {
    631 	case SIOCGLIFADDR:
    632 		/* address must be specified on GET with IFLR_PREFIX */
    633 		if ((iflr->flags & IFLR_PREFIX) == 0)
    634 			break;
    635 		/*FALLTHROUGH*/
    636 	case SIOCALIFADDR:
    637 	case SIOCDLIFADDR:
    638 		/* address must be specified on ADD and DELETE */
    639 		sa = (struct sockaddr *)&iflr->addr;
    640 		if (sa->sa_family != AF_INET)
    641 			return EINVAL;
    642 		if (sa->sa_len != sizeof(struct sockaddr_in))
    643 			return EINVAL;
    644 		/* XXX need improvement */
    645 		sa = (struct sockaddr *)&iflr->dstaddr;
    646 		if (sa->sa_family
    647 		 && sa->sa_family != AF_INET)
    648 			return EINVAL;
    649 		if (sa->sa_len && sa->sa_len != sizeof(struct sockaddr_in))
    650 			return EINVAL;
    651 		break;
    652 	default: /*shouldn't happen*/
    653 #if 0
    654 		panic("invalid cmd to in_lifaddr_ioctl");
    655 		/*NOTREACHED*/
    656 #else
    657 		return EOPNOTSUPP;
    658 #endif
    659 	}
    660 	if (sizeof(struct in_addr) * 8 < iflr->prefixlen)
    661 		return EINVAL;
    662 
    663 	switch (cmd) {
    664 	case SIOCALIFADDR:
    665 	    {
    666 		struct in_aliasreq ifra;
    667 
    668 		if (iflr->flags & IFLR_PREFIX)
    669 			return EINVAL;
    670 
    671 		/* copy args to in_aliasreq, perform ioctl(SIOCAIFADDR_IN6). */
    672 		bzero(&ifra, sizeof(ifra));
    673 		bcopy(iflr->iflr_name, ifra.ifra_name,
    674 			sizeof(ifra.ifra_name));
    675 
    676 		bcopy(&iflr->addr, &ifra.ifra_addr,
    677 			((struct sockaddr *)&iflr->addr)->sa_len);
    678 
    679 		if (((struct sockaddr *)&iflr->dstaddr)->sa_family) {	/*XXX*/
    680 			bcopy(&iflr->dstaddr, &ifra.ifra_dstaddr,
    681 				((struct sockaddr *)&iflr->dstaddr)->sa_len);
    682 		}
    683 
    684 		ifra.ifra_mask.sin_family = AF_INET;
    685 		ifra.ifra_mask.sin_len = sizeof(struct sockaddr_in);
    686 		in_len2mask(&ifra.ifra_mask.sin_addr, iflr->prefixlen);
    687 
    688 		return in_control(so, SIOCAIFADDR, (caddr_t)&ifra, ifp, p);
    689 	    }
    690 	case SIOCGLIFADDR:
    691 	case SIOCDLIFADDR:
    692 	    {
    693 		struct in_ifaddr *ia;
    694 		struct in_addr mask, candidate, match;
    695 		struct sockaddr_in *sin;
    696 		int cmp;
    697 
    698 		bzero(&mask, sizeof(mask));
    699 		if (iflr->flags & IFLR_PREFIX) {
    700 			/* lookup a prefix rather than address. */
    701 			in_len2mask(&mask, iflr->prefixlen);
    702 
    703 			sin = (struct sockaddr_in *)&iflr->addr;
    704 			match.s_addr = sin->sin_addr.s_addr;
    705 			match.s_addr &= mask.s_addr;
    706 
    707 			/* if you set extra bits, that's wrong */
    708 			if (match.s_addr != sin->sin_addr.s_addr)
    709 				return EINVAL;
    710 
    711 			cmp = 1;
    712 		} else {
    713 			if (cmd == SIOCGLIFADDR) {
    714 				/* on getting an address, take the 1st match */
    715 				cmp = 0;	/*XXX*/
    716 			} else {
    717 				/* on deleting an address, do exact match */
    718 				in_len2mask(&mask, 32);
    719 				sin = (struct sockaddr_in *)&iflr->addr;
    720 				match.s_addr = sin->sin_addr.s_addr;
    721 
    722 				cmp = 1;
    723 			}
    724 		}
    725 
    726 		for (ifa = ifp->if_addrlist.tqh_first; ifa; ifa = ifa->ifa_list.tqe_next) {
    727 			if (ifa->ifa_addr->sa_family != AF_INET6)
    728 				continue;
    729 			if (!cmp)
    730 				break;
    731 			candidate.s_addr = ((struct sockaddr_in *)&ifa->ifa_addr)->sin_addr.s_addr;
    732 			candidate.s_addr &= mask.s_addr;
    733 			if (candidate.s_addr == match.s_addr)
    734 				break;
    735 		}
    736 		if (!ifa)
    737 			return EADDRNOTAVAIL;
    738 		ia = (struct in_ifaddr *)ifa;
    739 
    740 		if (cmd == SIOCGLIFADDR) {
    741 			/* fill in the if_laddrreq structure */
    742 			bcopy(&ia->ia_addr, &iflr->addr, ia->ia_addr.sin_len);
    743 
    744 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
    745 				bcopy(&ia->ia_dstaddr, &iflr->dstaddr,
    746 					ia->ia_dstaddr.sin_len);
    747 			} else
    748 				bzero(&iflr->dstaddr, sizeof(iflr->dstaddr));
    749 
    750 			iflr->prefixlen =
    751 				in_mask2len(&ia->ia_sockmask.sin_addr);
    752 
    753 			iflr->flags = 0;	/*XXX*/
    754 
    755 			return 0;
    756 		} else {
    757 			struct in_aliasreq ifra;
    758 
    759 			/* fill in_aliasreq and do ioctl(SIOCDIFADDR_IN6) */
    760 			bzero(&ifra, sizeof(ifra));
    761 			bcopy(iflr->iflr_name, ifra.ifra_name,
    762 				sizeof(ifra.ifra_name));
    763 
    764 			bcopy(&ia->ia_addr, &ifra.ifra_addr,
    765 				ia->ia_addr.sin_len);
    766 			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
    767 				bcopy(&ia->ia_dstaddr, &ifra.ifra_dstaddr,
    768 					ia->ia_dstaddr.sin_len);
    769 			}
    770 			bcopy(&ia->ia_sockmask, &ifra.ifra_dstaddr,
    771 				ia->ia_sockmask.sin_len);
    772 
    773 			return in_control(so, SIOCDIFADDR, (caddr_t)&ifra,
    774 				ifp, p);
    775 		}
    776 	    }
    777 	}
    778 
    779 	return EOPNOTSUPP;	/*just for safety*/
    780 }
    781 
    782 /*
    783  * Delete any existing route for an interface.
    784  */
    785 void
    786 in_ifscrub(ifp, ia)
    787 	struct ifnet *ifp;
    788 	struct in_ifaddr *ia;
    789 {
    790 
    791 	if ((ia->ia_flags & IFA_ROUTE) == 0)
    792 		return;
    793 	if (ifp->if_flags & (IFF_LOOPBACK|IFF_POINTOPOINT))
    794 		rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST);
    795 	else
    796 		rtinit(&(ia->ia_ifa), (int)RTM_DELETE, 0);
    797 	ia->ia_flags &= ~IFA_ROUTE;
    798 }
    799 
    800 /*
    801  * Initialize an interface's internet address
    802  * and routing table entry.
    803  */
    804 int
    805 in_ifinit(ifp, ia, sin, scrub)
    806 	struct ifnet *ifp;
    807 	struct in_ifaddr *ia;
    808 	struct sockaddr_in *sin;
    809 	int scrub;
    810 {
    811 	u_int32_t i = sin->sin_addr.s_addr;
    812 	struct sockaddr_in oldaddr;
    813 	int s = splimp(), flags = RTF_UP, error;
    814 
    815 	/*
    816 	 * Set up new addresses.
    817 	 */
    818 	oldaddr = ia->ia_addr;
    819 	if (ia->ia_addr.sin_family == AF_INET)
    820 		LIST_REMOVE(ia, ia_hash);
    821 	ia->ia_addr = *sin;
    822 	LIST_INSERT_HEAD(&IN_IFADDR_HASH(ia->ia_addr.sin_addr.s_addr), ia, ia_hash);
    823 
    824 	/*
    825 	 * Give the interface a chance to initialize
    826 	 * if this is its first address,
    827 	 * and to validate the address if necessary.
    828 	 */
    829 	if (ifp->if_ioctl &&
    830 	    (error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia)))
    831 		goto bad;
    832 	splx(s);
    833 	if (scrub) {
    834 		ia->ia_ifa.ifa_addr = sintosa(&oldaddr);
    835 		in_ifscrub(ifp, ia);
    836 		ia->ia_ifa.ifa_addr = sintosa(&ia->ia_addr);
    837 	}
    838 
    839 	if (IN_CLASSA(i))
    840 		ia->ia_netmask = IN_CLASSA_NET;
    841 	else if (IN_CLASSB(i))
    842 		ia->ia_netmask = IN_CLASSB_NET;
    843 	else
    844 		ia->ia_netmask = IN_CLASSC_NET;
    845 	/*
    846 	 * The subnet mask usually includes at least the standard network part,
    847 	 * but may may be smaller in the case of supernetting.
    848 	 * If it is set, we believe it.
    849 	 */
    850 	if (ia->ia_subnetmask == 0) {
    851 		ia->ia_subnetmask = ia->ia_netmask;
    852 		ia->ia_sockmask.sin_addr.s_addr = ia->ia_subnetmask;
    853 	} else
    854 		ia->ia_netmask &= ia->ia_subnetmask;
    855 
    856 	ia->ia_net = i & ia->ia_netmask;
    857 	ia->ia_subnet = i & ia->ia_subnetmask;
    858 	in_socktrim(&ia->ia_sockmask);
    859 	/* re-calculate the "in_maxmtu" value */
    860 	in_setmaxmtu();
    861 	/*
    862 	 * Add route for the network.
    863 	 */
    864 	ia->ia_ifa.ifa_metric = ifp->if_metric;
    865 	if (ifp->if_flags & IFF_BROADCAST) {
    866 		ia->ia_broadaddr.sin_addr.s_addr =
    867 			ia->ia_subnet | ~ia->ia_subnetmask;
    868 		ia->ia_netbroadcast.s_addr =
    869 			ia->ia_net | ~ia->ia_netmask;
    870 	} else if (ifp->if_flags & IFF_LOOPBACK) {
    871 		ia->ia_ifa.ifa_dstaddr = ia->ia_ifa.ifa_addr;
    872 		flags |= RTF_HOST;
    873 	} else if (ifp->if_flags & IFF_POINTOPOINT) {
    874 		if (ia->ia_dstaddr.sin_family != AF_INET)
    875 			return (0);
    876 		flags |= RTF_HOST;
    877 	}
    878 	error = rtinit(&ia->ia_ifa, (int)RTM_ADD, flags);
    879 	if (!error)
    880 		ia->ia_flags |= IFA_ROUTE;
    881 	/* XXX check if the subnet route points to the same interface */
    882 	if (error == EEXIST)
    883 		error = 0;
    884 	/*
    885 	 * If the interface supports multicast, join the "all hosts"
    886 	 * multicast group on that interface.
    887 	 */
    888 	if (ifp->if_flags & IFF_MULTICAST) {
    889 		struct in_addr addr;
    890 
    891 		addr.s_addr = INADDR_ALLHOSTS_GROUP;
    892 		in_addmulti(&addr, ifp);
    893 	}
    894 	return (error);
    895 bad:
    896 	splx(s);
    897 	LIST_REMOVE(ia, ia_hash);
    898 	ia->ia_addr = oldaddr;
    899 	if (ia->ia_addr.sin_family == AF_INET)
    900 		LIST_INSERT_HEAD(&IN_IFADDR_HASH(ia->ia_addr.sin_addr.s_addr),
    901 		    ia, ia_hash);
    902 	return (error);
    903 }
    904 
    905 /*
    906  * Return 1 if the address might be a local broadcast address.
    907  */
    908 int
    909 in_broadcast(in, ifp)
    910 	struct in_addr in;
    911 	struct ifnet *ifp;
    912 {
    913 	struct ifaddr *ifa;
    914 
    915 	if (in.s_addr == INADDR_BROADCAST ||
    916 	    in_nullhost(in))
    917 		return 1;
    918 	if ((ifp->if_flags & IFF_BROADCAST) == 0)
    919 		return 0;
    920 	/*
    921 	 * Look through the list of addresses for a match
    922 	 * with a broadcast address.
    923 	 */
    924 #define ia (ifatoia(ifa))
    925 	for (ifa = ifp->if_addrlist.tqh_first; ifa; ifa = ifa->ifa_list.tqe_next)
    926 		if (ifa->ifa_addr->sa_family == AF_INET &&
    927 		    (in_hosteq(in, ia->ia_broadaddr.sin_addr) ||
    928 		     in_hosteq(in, ia->ia_netbroadcast) ||
    929 		     (hostzeroisbroadcast &&
    930 		      /*
    931 		       * Check for old-style (host 0) broadcast.
    932 		       */
    933 		      (in.s_addr == ia->ia_subnet ||
    934 		       in.s_addr == ia->ia_net))))
    935 			return 1;
    936 	return (0);
    937 #undef ia
    938 }
    939 
    940 /*
    941  * Add an address to the list of IP multicast addresses for a given interface.
    942  */
    943 struct in_multi *
    944 in_addmulti(ap, ifp)
    945 	struct in_addr *ap;
    946 	struct ifnet *ifp;
    947 {
    948 	struct in_multi *inm;
    949 	struct ifreq ifr;
    950 	struct in_ifaddr *ia;
    951 	int s = splsoftnet();
    952 
    953 	/*
    954 	 * See if address already in list.
    955 	 */
    956 	IN_LOOKUP_MULTI(*ap, ifp, inm);
    957 	if (inm != NULL) {
    958 		/*
    959 		 * Found it; just increment the reference count.
    960 		 */
    961 		++inm->inm_refcount;
    962 	} else {
    963 		/*
    964 		 * New address; allocate a new multicast record
    965 		 * and link it into the interface's multicast list.
    966 		 */
    967 		inm = (struct in_multi *)malloc(sizeof(*inm),
    968 		    M_IPMADDR, M_NOWAIT);
    969 		if (inm == NULL) {
    970 			splx(s);
    971 			return (NULL);
    972 		}
    973 		inm->inm_addr = *ap;
    974 		inm->inm_ifp = ifp;
    975 		inm->inm_refcount = 1;
    976 		IFP_TO_IA(ifp, ia);
    977 		if (ia == NULL) {
    978 			free(inm, M_IPMADDR);
    979 			splx(s);
    980 			return (NULL);
    981 		}
    982 		inm->inm_ia = ia;
    983 		IFAREF(&inm->inm_ia->ia_ifa);
    984 		LIST_INSERT_HEAD(&ia->ia_multiaddrs, inm, inm_list);
    985 		/*
    986 		 * Ask the network driver to update its multicast reception
    987 		 * filter appropriately for the new address.
    988 		 */
    989 		satosin(&ifr.ifr_addr)->sin_len = sizeof(struct sockaddr_in);
    990 		satosin(&ifr.ifr_addr)->sin_family = AF_INET;
    991 		satosin(&ifr.ifr_addr)->sin_addr = *ap;
    992 		if ((ifp->if_ioctl == NULL) ||
    993 		    (*ifp->if_ioctl)(ifp, SIOCADDMULTI,(caddr_t)&ifr) != 0) {
    994 			LIST_REMOVE(inm, inm_list);
    995 			free(inm, M_IPMADDR);
    996 			splx(s);
    997 			return (NULL);
    998 		}
    999 		/*
   1000 		 * Let IGMP know that we have joined a new IP multicast group.
   1001 		 */
   1002 		igmp_joingroup(inm);
   1003 	}
   1004 	splx(s);
   1005 	return (inm);
   1006 }
   1007 
   1008 /*
   1009  * Delete a multicast address record.
   1010  */
   1011 void
   1012 in_delmulti(inm)
   1013 	struct in_multi *inm;
   1014 {
   1015 	struct ifreq ifr;
   1016 	int s = splsoftnet();
   1017 
   1018 	if (--inm->inm_refcount == 0) {
   1019 		/*
   1020 		 * No remaining claims to this record; let IGMP know that
   1021 		 * we are leaving the multicast group.
   1022 		 */
   1023 		igmp_leavegroup(inm);
   1024 		/*
   1025 		 * Unlink from list.
   1026 		 */
   1027 		LIST_REMOVE(inm, inm_list);
   1028 		IFAFREE(&inm->inm_ia->ia_ifa);
   1029 		/*
   1030 		 * Notify the network driver to update its multicast reception
   1031 		 * filter.
   1032 		 */
   1033 		satosin(&ifr.ifr_addr)->sin_family = AF_INET;
   1034 		satosin(&ifr.ifr_addr)->sin_addr = inm->inm_addr;
   1035 		(*inm->inm_ifp->if_ioctl)(inm->inm_ifp, SIOCDELMULTI,
   1036 							     (caddr_t)&ifr);
   1037 		free(inm, M_IPMADDR);
   1038 	}
   1039 	splx(s);
   1040 }
   1041 #endif
   1042