sys/netinet/in.c

   1 /*-
   2  * Copyright (c) 1982, 1986, 1991, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  * Copyright (C) 2001 WIDE Project.  All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 4. Neither the name of the University nor the names of its contributors
  15  *    may be used to endorse or promote products derived from this software
  16  *    without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  28  * SUCH DAMAGE.
  29  *
  30  *      @(#)in.c        8.4 (Berkeley) 1/9/95
  31  */
  32
  33 #include <sys/cdefs.h>
  34 __FBSDID("$FreeBSD$");
  35
  36 #include "opt_carp.h"
  37
  38 #include <sys/param.h>
  39 #include <sys/systm.h>
  40 #include <sys/sockio.h>
  41 #include <sys/malloc.h>
  42 #include <sys/priv.h>
  43 #include <sys/socket.h>
  44 #include <sys/kernel.h>
  45 #include <sys/sysctl.h>
  46
  47 #include <net/if.h>
  48 #include <net/if_types.h>
  49 #include <net/route.h>
  50
  51 #include <netinet/in.h>
  52 #include <netinet/in_var.h>
  53 #include <netinet/in_pcb.h>
  54 #include <netinet/ip_var.h>
  55
  56 static int in_mask2len(struct in_addr *);
  57 static void in_len2mask(struct in_addr *, int);
  58 static int in_lifaddr_ioctl(struct socket *, u_long, caddr_t,
  59         struct ifnet *, struct thread *);
  60
  61 static int      in_addprefix(struct in_ifaddr *, int);
  62 static int      in_scrubprefix(struct in_ifaddr *);
  63 static void     in_socktrim(struct sockaddr_in *);
  64 static int      in_ifinit(struct ifnet *,
  65             struct in_ifaddr *, struct sockaddr_in *, int);
  66 static void     in_purgemaddrs(struct ifnet *);
  67
  68 static int subnetsarelocal = 0;
  69 SYSCTL_INT(_net_inet_ip, OID_AUTO, subnets_are_local, CTLFLAG_RW,
  70         &subnetsarelocal, 0, "Treat all subnets as directly connected");
  71 static int sameprefixcarponly = 0;
  72 SYSCTL_INT(_net_inet_ip, OID_AUTO, same_prefix_carp_only, CTLFLAG_RW,
  73         &sameprefixcarponly, 0,
  74         "Refuse to create same prefixes on different interfaces");
  75
  76 extern struct inpcbinfo ripcbinfo;
  77 extern struct inpcbinfo udbinfo;
  78
  79 /*
  80  * Return 1 if an internet address is for a ``local'' host
  81  * (one to which we have a connection).  If subnetsarelocal
  82  * is true, this includes other subnets of the local net.
  83  * Otherwise, it includes only the directly-connected (sub)nets.
  84  */
  85 int
  86 in_localaddr(struct in_addr in)
  87 {
  88         register u_long i = ntohl(in.s_addr);
  89         register struct in_ifaddr *ia;
  90
  91         if (subnetsarelocal) {
  92                 TAILQ_FOREACH(ia, &in_ifaddrhead, ia_link)
  93                         if ((i & ia->ia_netmask) == ia->ia_net)
  94                                 return (1);
  95         } else {
  96                 TAILQ_FOREACH(ia, &in_ifaddrhead, ia_link)
  97                         if ((i & ia->ia_subnetmask) == ia->ia_subnet)
  98                                 return (1);
  99         }
 100         return (0);
 101 }
 102
 103 /*
 104  * Return 1 if an internet address is for the local host and configured
 105  * on one of its interfaces.
 106  */
 107 int
 108 in_localip(struct in_addr in)
 109 {
 110         struct in_ifaddr *ia;
 111
 112         LIST_FOREACH(ia, INADDR_HASH(in.s_addr), ia_hash) {
 113                 if (IA_SIN(ia)->sin_addr.s_addr == in.s_addr)
 114                         return 1;
 115         }
 116         return 0;
 117 }
 118
 119 /*
 120  * Determine whether an IP address is in a reserved set of addresses
 121  * that may not be forwarded, or whether datagrams to that destination
 122  * may be forwarded.
 123  */
 124 int
 125 in_canforward(struct in_addr in)
 126 {
 127         register u_long i = ntohl(in.s_addr);
 128         register u_long net;
 129
 130         if (IN_EXPERIMENTAL(i) || IN_MULTICAST(i) || IN_LINKLOCAL(i))
 131                 return (0);
 132         if (IN_CLASSA(i)) {
 133                 net = i & IN_CLASSA_NET;
 134                 if (net == 0 || net == (IN_LOOPBACKNET << IN_CLASSA_NSHIFT))
 135                         return (0);
 136         }
 137         return (1);
 138 }
 139
 140 /*
 141  * Trim a mask in a sockaddr
 142  */
 143 static void
 144 in_socktrim(struct sockaddr_in *ap)
 145 {
 146     register char *cplim = (char *) &ap->sin_addr;
 147     register char *cp = (char *) (&ap->sin_addr + 1);
 148
 149     ap->sin_len = 0;
 150     while (--cp >= cplim)
 151         if (*cp) {
 152             (ap)->sin_len = cp - (char *) (ap) + 1;
 153             break;
 154         }
 155 }
 156
 157 static int
 158 in_mask2len(mask)
 159         struct in_addr *mask;
 160 {
 161         int x, y;
 162         u_char *p;
 163
 164         p = (u_char *)mask;
 165         for (x = 0; x < sizeof(*mask); x++) {
 166                 if (p[x] != 0xff)
 167                         break;
 168         }
 169         y = 0;
 170         if (x < sizeof(*mask)) {
 171                 for (y = 0; y < 8; y++) {
 172                         if ((p[x] & (0x80 >> y)) == 0)
 173                                 break;
 174                 }
 175         }
 176         return x * 8 + y;
 177 }
 178
 179 static void
 180 in_len2mask(struct in_addr *mask, int len)
 181 {
 182         int i;
 183         u_char *p;
 184
 185         p = (u_char *)mask;
 186         bzero(mask, sizeof(*mask));
 187         for (i = 0; i < len / 8; i++)
 188                 p[i] = 0xff;
 189         if (len % 8)
 190                 p[i] = (0xff00 >> (len % 8)) & 0xff;
 191 }
 192
 193 /*
 194  * Generic internet control operations (ioctl's).
 195  * Ifp is 0 if not an interface-specific ioctl.
 196  */
 197 /* ARGSUSED */
 198 int
 199 in_control(struct socket *so, u_long cmd, caddr_t data, struct ifnet *ifp,
 200     struct thread *td)
 201 {
 202         register struct ifreq *ifr = (struct ifreq *)data;
 203         register struct in_ifaddr *ia = 0, *iap;
 204         register struct ifaddr *ifa;
 205         struct in_addr allhosts_addr;
 206         struct in_addr dst;
 207         struct in_ifaddr *oia;
 208         struct in_aliasreq *ifra = (struct in_aliasreq *)data;
 209         struct sockaddr_in oldaddr;
 210         int error, hostIsNew, iaIsNew, maskIsNew, s;
 211         int iaIsFirst;
 212
 213         iaIsFirst = 0;
 214         iaIsNew = 0;
 215         allhosts_addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);
 216
 217         switch (cmd) {
 218         case SIOCALIFADDR:
 219                 if (td != NULL) {
 220                         error = priv_check(td, PRIV_NET_ADDIFADDR);
 221                         if (error)
 222                                 return (error);
 223                 }
 224                 if (!ifp)
 225                         return EINVAL;
 226                 return in_lifaddr_ioctl(so, cmd, data, ifp, td);
 227
 228         case SIOCDLIFADDR:
 229                 if (td != NULL) {
 230                         error = priv_check(td, PRIV_NET_DELIFADDR);
 231                         if (error)
 232                                 return (error);
 233                 }
 234                 if (!ifp)
 235                         return EINVAL;
 236                 return in_lifaddr_ioctl(so, cmd, data, ifp, td);
 237
 238         case SIOCGLIFADDR:
 239                 if (!ifp)
 240                         return EINVAL;
 241                 return in_lifaddr_ioctl(so, cmd, data, ifp, td);
 242         }
 243
 244         /*
 245          * Find address for this interface, if it exists.
 246          *
 247          * If an alias address was specified, find that one instead of
 248          * the first one on the interface, if possible.
 249          */
 250         if (ifp) {
 251                 dst = ((struct sockaddr_in *)&ifr->ifr_addr)->sin_addr;
 252                 LIST_FOREACH(iap, INADDR_HASH(dst.s_addr), ia_hash)
 253                         if (iap->ia_ifp == ifp &&
 254                             iap->ia_addr.sin_addr.s_addr == dst.s_addr) {
 255                                 ia = iap;
 256                                 break;
 257                         }
 258                 if (ia == NULL)
 259                         TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
 260                                 iap = ifatoia(ifa);
 261                                 if (iap->ia_addr.sin_family == AF_INET) {
 262                                         ia = iap;
 263                                         break;
 264                                 }
 265                         }
 266                 if (ia == NULL)
 267                         iaIsFirst = 1;
 268         }
 269
 270         switch (cmd) {
 271
 272         case SIOCAIFADDR:
 273         case SIOCDIFADDR:
 274                 if (ifp == 0)
 275                         return (EADDRNOTAVAIL);
 276                 if (ifra->ifra_addr.sin_family == AF_INET) {
 277                         for (oia = ia; ia; ia = TAILQ_NEXT(ia, ia_link)) {
 278                                 if (ia->ia_ifp == ifp  &&
 279                                     ia->ia_addr.sin_addr.s_addr ==
 280                                     ifra->ifra_addr.sin_addr.s_addr)
 281                                         break;
 282                         }
 283                         if ((ifp->if_flags & IFF_POINTOPOINT)
 284                             && (cmd == SIOCAIFADDR)
 285                             && (ifra->ifra_dstaddr.sin_addr.s_addr
 286                                 == INADDR_ANY)) {
 287                                 return EDESTADDRREQ;
 288                         }
 289                 }
 290                 if (cmd == SIOCDIFADDR && ia == 0)
 291                         return (EADDRNOTAVAIL);
 292                 /* FALLTHROUGH */
 293         case SIOCSIFADDR:
 294         case SIOCSIFNETMASK:
 295         case SIOCSIFDSTADDR:
 296                 if (td != NULL) {
 297                         error = priv_check(td, PRIV_NET_ADDIFADDR);
 298                         if (error)
 299                                 return (error);
 300                 }
 301
 302                 if (ifp == 0)
 303                         return (EADDRNOTAVAIL);
 304                 if (ia == (struct in_ifaddr *)0) {
 305                         ia = (struct in_ifaddr *)
 306                                 malloc(sizeof *ia, M_IFADDR, M_WAITOK | M_ZERO);
 307                         if (ia == (struct in_ifaddr *)NULL)
 308                                 return (ENOBUFS);
 309                         /*
 310                          * Protect from ipintr() traversing address list
 311                          * while we're modifying it.
 312                          */
 313                         s = splnet();
 314                         ifa = &ia->ia_ifa;
 315                         IFA_LOCK_INIT(ifa);
 316                         ifa->ifa_addr = (struct sockaddr *)&ia->ia_addr;
 317                         ifa->ifa_dstaddr = (struct sockaddr *)&ia->ia_dstaddr;
 318                         ifa->ifa_netmask = (struct sockaddr *)&ia->ia_sockmask;
 319                         ifa->ifa_refcnt = 1;
 320                         TAILQ_INSERT_TAIL(&ifp->if_addrhead, ifa, ifa_link);
 321
 322                         ia->ia_sockmask.sin_len = 8;
 323                         ia->ia_sockmask.sin_family = AF_INET;
 324                         if (ifp->if_flags & IFF_BROADCAST) {
 325                                 ia->ia_broadaddr.sin_len = sizeof(ia->ia_addr);
 326                                 ia->ia_broadaddr.sin_family = AF_INET;
 327                         }
 328                         ia->ia_ifp = ifp;
 329
 330                         TAILQ_INSERT_TAIL(&in_ifaddrhead, ia, ia_link);
 331                         splx(s);
 332                         iaIsNew = 1;
 333                 }
 334                 break;
 335
 336         case SIOCSIFBRDADDR:
 337                 if (td != NULL) {
 338                         error = priv_check(td, PRIV_NET_ADDIFADDR);
 339                         if (error)
 340                                 return (error);
 341                 }
 342                 /* FALLTHROUGH */
 343
 344         case SIOCGIFADDR:
 345         case SIOCGIFNETMASK:
 346         case SIOCGIFDSTADDR:
 347         case SIOCGIFBRDADDR:
 348                 if (ia == (struct in_ifaddr *)0)
 349                         return (EADDRNOTAVAIL);
 350                 break;
 351         }
 352         switch (cmd) {
 353
 354         case SIOCGIFADDR:
 355                 *((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_addr;
 356                 return (0);
 357
 358         case SIOCGIFBRDADDR:
 359                 if ((ifp->if_flags & IFF_BROADCAST) == 0)
 360                         return (EINVAL);
 361                 *((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_broadaddr;
 362                 return (0);
 363
 364         case SIOCGIFDSTADDR:
 365                 if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
 366                         return (EINVAL);
 367                 *((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_dstaddr;
 368                 return (0);
 369
 370         case SIOCGIFNETMASK:
 371                 *((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_sockmask;
 372                 return (0);
 373
 374         case SIOCSIFDSTADDR:
 375                 if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
 376                         return (EINVAL);
 377                 oldaddr = ia->ia_dstaddr;
 378                 ia->ia_dstaddr = *(struct sockaddr_in *)&ifr->ifr_dstaddr;
 379                 if (ifp->if_ioctl) {
 380                         IFF_LOCKGIANT(ifp);
 381                         error = (*ifp->if_ioctl)(ifp, SIOCSIFDSTADDR,
 382                             (caddr_t)ia);
 383                         IFF_UNLOCKGIANT(ifp);
 384                         if (error) {
 385                                 ia->ia_dstaddr = oldaddr;
 386                                 return (error);
 387                         }
 388                 }
 389                 if (ia->ia_flags & IFA_ROUTE) {
 390                         ia->ia_ifa.ifa_dstaddr = (struct sockaddr *)&oldaddr;
 391                         rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST);
 392                         ia->ia_ifa.ifa_dstaddr =
 393                                         (struct sockaddr *)&ia->ia_dstaddr;
 394                         rtinit(&(ia->ia_ifa), (int)RTM_ADD, RTF_HOST|RTF_UP);
 395                 }
 396                 return (0);
 397
 398         case SIOCSIFBRDADDR:
 399                 if ((ifp->if_flags & IFF_BROADCAST) == 0)
 400                         return (EINVAL);
 401                 ia->ia_broadaddr = *(struct sockaddr_in *)&ifr->ifr_broadaddr;
 402                 return (0);
 403
 404         case SIOCSIFADDR:
 405                 error = in_ifinit(ifp, ia,
 406                     (struct sockaddr_in *) &ifr->ifr_addr, 1);
 407                 if (error != 0 && iaIsNew)
 408                         break;
 409                 if (error == 0) {
 410                         if (iaIsFirst && (ifp->if_flags & IFF_MULTICAST) != 0)
 411                                 in_addmulti(&allhosts_addr, ifp);
 412                         EVENTHANDLER_INVOKE(ifaddr_event, ifp);
 413                 }
 414                 return (0);
 415
 416         case SIOCSIFNETMASK:
 417                 ia->ia_sockmask.sin_addr = ifra->ifra_addr.sin_addr;
 418                 ia->ia_subnetmask = ntohl(ia->ia_sockmask.sin_addr.s_addr);
 419                 return (0);
 420
 421         case SIOCAIFADDR:
 422                 maskIsNew = 0;
 423                 hostIsNew = 1;
 424                 error = 0;
 425                 if (ia->ia_addr.sin_family == AF_INET) {
 426                         if (ifra->ifra_addr.sin_len == 0) {
 427                                 ifra->ifra_addr = ia->ia_addr;
 428                                 hostIsNew = 0;
 429                         } else if (ifra->ifra_addr.sin_addr.s_addr ==
 430                                                ia->ia_addr.sin_addr.s_addr)
 431                                 hostIsNew = 0;
 432                 }
 433                 if (ifra->ifra_mask.sin_len) {
 434                         in_ifscrub(ifp, ia);
 435                         ia->ia_sockmask = ifra->ifra_mask;
 436                         ia->ia_sockmask.sin_family = AF_INET;
 437                         ia->ia_subnetmask =
 438                              ntohl(ia->ia_sockmask.sin_addr.s_addr);
 439                         maskIsNew = 1;
 440                 }
 441                 if ((ifp->if_flags & IFF_POINTOPOINT) &&
 442                     (ifra->ifra_dstaddr.sin_family == AF_INET)) {
 443                         in_ifscrub(ifp, ia);
 444                         ia->ia_dstaddr = ifra->ifra_dstaddr;
 445                         maskIsNew  = 1; /* We lie; but the effect's the same */
 446                 }
 447                 if (ifra->ifra_addr.sin_family == AF_INET &&
 448                     (hostIsNew || maskIsNew))
 449                         error = in_ifinit(ifp, ia, &ifra->ifra_addr, 0);
 450                 if (error != 0 && iaIsNew)
 451                         break;
 452
 453                 if ((ifp->if_flags & IFF_BROADCAST) &&
 454                     (ifra->ifra_broadaddr.sin_family == AF_INET))
 455                         ia->ia_broadaddr = ifra->ifra_broadaddr;
 456                 if (error == 0) {
 457                         if (iaIsFirst && (ifp->if_flags & IFF_MULTICAST) != 0)
 458                                 in_addmulti(&allhosts_addr, ifp);
 459                         EVENTHANDLER_INVOKE(ifaddr_event, ifp);
 460                 }
 461                 return (error);
 462
 463         case SIOCDIFADDR:
 464                 /*
 465                  * in_ifscrub kills the interface route.
 466                  */
 467                 in_ifscrub(ifp, ia);
 468                 /*
 469                  * in_ifadown gets rid of all the rest of
 470                  * the routes.  This is not quite the right
 471                  * thing to do, but at least if we are running
 472                  * a routing process they will come back.
 473                  */
 474                 in_ifadown(&ia->ia_ifa, 1);
 475                 EVENTHANDLER_INVOKE(ifaddr_event, ifp);
 476                 error = 0;
 477                 break;
 478
 479         default:
 480                 if (ifp == 0 || ifp->if_ioctl == 0)
 481                         return (EOPNOTSUPP);
 482                 IFF_LOCKGIANT(ifp);
 483                 error = (*ifp->if_ioctl)(ifp, cmd, data);
 484                 IFF_UNLOCKGIANT(ifp);
 485                 return (error);
 486         }
 487
 488         /*
 489          * Protect from ipintr() traversing address list while we're modifying
 490          * it.
 491          */
 492         s = splnet();
 493         TAILQ_REMOVE(&ifp->if_addrhead, &ia->ia_ifa, ifa_link);
 494         TAILQ_REMOVE(&in_ifaddrhead, ia, ia_link);
 495         if (ia->ia_addr.sin_family == AF_INET) {
 496                 LIST_REMOVE(ia, ia_hash);
 497                 /*
 498                  * If this is the last IPv4 address configured on this
 499                  * interface, leave the all-hosts group.
 500                  * XXX: This is quite ugly because of locking and structure.
 501                  */
 502                 oia = NULL;
 503                 IFP_TO_IA(ifp, oia);
 504                 if (oia == NULL) {
 505                         struct in_multi *inm;
 506
 507                         IFF_LOCKGIANT(ifp);
 508                         IN_MULTI_LOCK();
 509                         IN_LOOKUP_MULTI(allhosts_addr, ifp, inm);
 510                         if (inm != NULL)
 511                                 in_delmulti_locked(inm);
 512                         IN_MULTI_UNLOCK();
 513                         IFF_UNLOCKGIANT(ifp);
 514                 }
 515         }
 516         IFAFREE(&ia->ia_ifa);
 517         splx(s);
 518
 519         return (error);
 520 }
 521
 522 /*
 523  * SIOC[GAD]LIFADDR.
 524  *      SIOCGLIFADDR: get first address. (?!?)
 525  *      SIOCGLIFADDR with IFLR_PREFIX:
 526  *              get first address that matches the specified prefix.
 527  *      SIOCALIFADDR: add the specified address.
 528  *      SIOCALIFADDR with IFLR_PREFIX:
 529  *              EINVAL since we can't deduce hostid part of the address.
 530  *      SIOCDLIFADDR: delete the specified address.
 531  *      SIOCDLIFADDR with IFLR_PREFIX:
 532  *              delete the first address that matches the specified prefix.
 533  * return values:
 534  *      EINVAL on invalid parameters
 535  *      EADDRNOTAVAIL on prefix match failed/specified address not found
 536  *      other values may be returned from in_ioctl()
 537  */
 538 static int
 539 in_lifaddr_ioctl(struct socket *so, u_long cmd, caddr_t data,
 540     struct ifnet *ifp, struct thread *td)
 541 {
 542         struct if_laddrreq *iflr = (struct if_laddrreq *)data;
 543         struct ifaddr *ifa;
 544
 545         /* sanity checks */
 546         if (!data || !ifp) {
 547                 panic("invalid argument to in_lifaddr_ioctl");
 548                 /*NOTRECHED*/
 549         }
 550
 551         switch (cmd) {
 552         case SIOCGLIFADDR:
 553                 /* address must be specified on GET with IFLR_PREFIX */
 554                 if ((iflr->flags & IFLR_PREFIX) == 0)
 555                         break;
 556                 /*FALLTHROUGH*/
 557         case SIOCALIFADDR:
 558         case SIOCDLIFADDR:
 559                 /* address must be specified on ADD and DELETE */
 560                 if (iflr->addr.ss_family != AF_INET)
 561                         return EINVAL;
 562                 if (iflr->addr.ss_len != sizeof(struct sockaddr_in))
 563                         return EINVAL;
 564                 /* XXX need improvement */
 565                 if (iflr->dstaddr.ss_family
 566                  && iflr->dstaddr.ss_family != AF_INET)
 567                         return EINVAL;
 568                 if (iflr->dstaddr.ss_family
 569                  && iflr->dstaddr.ss_len != sizeof(struct sockaddr_in))
 570                         return EINVAL;
 571                 break;
 572         default: /*shouldn't happen*/
 573                 return EOPNOTSUPP;
 574         }
 575         if (sizeof(struct in_addr) * 8 < iflr->prefixlen)
 576                 return EINVAL;
 577
 578         switch (cmd) {
 579         case SIOCALIFADDR:
 580             {
 581                 struct in_aliasreq ifra;
 582
 583                 if (iflr->flags & IFLR_PREFIX)
 584                         return EINVAL;
 585
 586                 /* copy args to in_aliasreq, perform ioctl(SIOCAIFADDR_IN6). */
 587                 bzero(&ifra, sizeof(ifra));
 588                 bcopy(iflr->iflr_name, ifra.ifra_name,
 589                         sizeof(ifra.ifra_name));
 590
 591                 bcopy(&iflr->addr, &ifra.ifra_addr, iflr->addr.ss_len);
 592
 593                 if (iflr->dstaddr.ss_family) {  /*XXX*/
 594                         bcopy(&iflr->dstaddr, &ifra.ifra_dstaddr,
 595                                 iflr->dstaddr.ss_len);
 596                 }
 597
 598                 ifra.ifra_mask.sin_family = AF_INET;
 599                 ifra.ifra_mask.sin_len = sizeof(struct sockaddr_in);
 600                 in_len2mask(&ifra.ifra_mask.sin_addr, iflr->prefixlen);
 601
 602                 return in_control(so, SIOCAIFADDR, (caddr_t)&ifra, ifp, td);
 603             }
 604         case SIOCGLIFADDR:
 605         case SIOCDLIFADDR:
 606             {
 607                 struct in_ifaddr *ia;
 608                 struct in_addr mask, candidate, match;
 609                 struct sockaddr_in *sin;
 610
 611                 bzero(&mask, sizeof(mask));
 612                 bzero(&match, sizeof(match));
 613                 if (iflr->flags & IFLR_PREFIX) {
 614                         /* lookup a prefix rather than address. */
 615                         in_len2mask(&mask, iflr->prefixlen);
 616
 617                         sin = (struct sockaddr_in *)&iflr->addr;
 618                         match.s_addr = sin->sin_addr.s_addr;
 619                         match.s_addr &= mask.s_addr;
 620
 621                         /* if you set extra bits, that's wrong */
 622                         if (match.s_addr != sin->sin_addr.s_addr)
 623                                 return EINVAL;
 624
 625                 } else {
 626                         /* on getting an address, take the 1st match */
 627                         /* on deleting an address, do exact match */
 628                         if (cmd != SIOCGLIFADDR) {
 629                                 in_len2mask(&mask, 32);
 630                                 sin = (struct sockaddr_in *)&iflr->addr;
 631                                 match.s_addr = sin->sin_addr.s_addr;
 632                         }
 633                 }
 634
 635                 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
 636                         if (ifa->ifa_addr->sa_family != AF_INET6)
 637                                 continue;
 638                         if (match.s_addr == 0)
 639                                 break;
 640                         candidate.s_addr = ((struct sockaddr_in *)&ifa->ifa_addr)->sin_addr.s_addr;
 641                         candidate.s_addr &= mask.s_addr;
 642                         if (candidate.s_addr == match.s_addr)
 643                                 break;
 644                 }
 645                 if (!ifa)
 646                         return EADDRNOTAVAIL;
 647                 ia = (struct in_ifaddr *)ifa;
 648
 649                 if (cmd == SIOCGLIFADDR) {
 650                         /* fill in the if_laddrreq structure */
 651                         bcopy(&ia->ia_addr, &iflr->addr, ia->ia_addr.sin_len);
 652
 653                         if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
 654                                 bcopy(&ia->ia_dstaddr, &iflr->dstaddr,
 655                                         ia->ia_dstaddr.sin_len);
 656                         } else
 657                                 bzero(&iflr->dstaddr, sizeof(iflr->dstaddr));
 658
 659                         iflr->prefixlen =
 660                                 in_mask2len(&ia->ia_sockmask.sin_addr);
 661
 662                         iflr->flags = 0;        /*XXX*/
 663
 664                         return 0;
 665                 } else {
 666                         struct in_aliasreq ifra;
 667
 668                         /* fill in_aliasreq and do ioctl(SIOCDIFADDR_IN6) */
 669                         bzero(&ifra, sizeof(ifra));
 670                         bcopy(iflr->iflr_name, ifra.ifra_name,
 671                                 sizeof(ifra.ifra_name));
 672
 673                         bcopy(&ia->ia_addr, &ifra.ifra_addr,
 674                                 ia->ia_addr.sin_len);
 675                         if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
 676                                 bcopy(&ia->ia_dstaddr, &ifra.ifra_dstaddr,
 677                                         ia->ia_dstaddr.sin_len);
 678                         }
 679                         bcopy(&ia->ia_sockmask, &ifra.ifra_dstaddr,
 680                                 ia->ia_sockmask.sin_len);
 681
 682                         return in_control(so, SIOCDIFADDR, (caddr_t)&ifra,
 683                                           ifp, td);
 684                 }
 685             }
 686         }
 687
 688         return EOPNOTSUPP;      /*just for safety*/
 689 }
 690
 691 /*
 692  * Delete any existing route for an interface.
 693  */
 694 void
 695 in_ifscrub(struct ifnet *ifp, struct in_ifaddr *ia)
 696 {
 697
 698         in_scrubprefix(ia);
 699 }
 700
 701 /*
 702  * Initialize an interface's internet address
 703  * and routing table entry.
 704  */
 705 static int
 706 in_ifinit(struct ifnet *ifp, struct in_ifaddr *ia, struct sockaddr_in *sin,
 707     int scrub)
 708 {
 709         register u_long i = ntohl(sin->sin_addr.s_addr);
 710         struct sockaddr_in oldaddr;
 711         int s = splimp(), flags = RTF_UP, error = 0;
 712
 713         oldaddr = ia->ia_addr;
 714         if (oldaddr.sin_family == AF_INET)
 715                 LIST_REMOVE(ia, ia_hash);
 716         ia->ia_addr = *sin;
 717         if (ia->ia_addr.sin_family == AF_INET)
 718                 LIST_INSERT_HEAD(INADDR_HASH(ia->ia_addr.sin_addr.s_addr),
 719                     ia, ia_hash);
 720         /*
 721          * Give the interface a chance to initialize
 722          * if this is its first address,
 723          * and to validate the address if necessary.
 724          */
 725         if (ifp->if_ioctl) {
 726                 IFF_LOCKGIANT(ifp);
 727                 error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia);
 728                 IFF_UNLOCKGIANT(ifp);
 729                 if (error) {
 730                         splx(s);
 731                         /* LIST_REMOVE(ia, ia_hash) is done in in_control */
 732                         ia->ia_addr = oldaddr;
 733                         if (ia->ia_addr.sin_family == AF_INET)
 734                                 LIST_INSERT_HEAD(INADDR_HASH(
 735                                     ia->ia_addr.sin_addr.s_addr), ia, ia_hash);
 736                         return (error);
 737                 }
 738         }
 739         splx(s);
 740         if (scrub) {
 741                 ia->ia_ifa.ifa_addr = (struct sockaddr *)&oldaddr;
 742                 in_ifscrub(ifp, ia);
 743                 ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr;
 744         }
 745         if (IN_CLASSA(i))
 746                 ia->ia_netmask = IN_CLASSA_NET;
 747         else if (IN_CLASSB(i))
 748                 ia->ia_netmask = IN_CLASSB_NET;
 749         else
 750                 ia->ia_netmask = IN_CLASSC_NET;
 751         /*
 752          * The subnet mask usually includes at least the standard network part,
 753          * but may may be smaller in the case of supernetting.
 754          * If it is set, we believe it.
 755          */
 756         if (ia->ia_subnetmask == 0) {
 757                 ia->ia_subnetmask = ia->ia_netmask;
 758                 ia->ia_sockmask.sin_addr.s_addr = htonl(ia->ia_subnetmask);
 759         } else
 760                 ia->ia_netmask &= ia->ia_subnetmask;
 761         ia->ia_net = i & ia->ia_netmask;
 762         ia->ia_subnet = i & ia->ia_subnetmask;
 763         in_socktrim(&ia->ia_sockmask);
 764 #ifdef DEV_CARP
 765         /*
 766          * XXX: carp(4) does not have interface route
 767          */
 768         if (ifp->if_type == IFT_CARP)
 769                 return (0);
 770 #endif
 771         /*
 772          * Add route for the network.
 773          */
 774         ia->ia_ifa.ifa_metric = ifp->if_metric;
 775         if (ifp->if_flags & IFF_BROADCAST) {
 776                 ia->ia_broadaddr.sin_addr.s_addr =
 777                         htonl(ia->ia_subnet | ~ia->ia_subnetmask);
 778                 ia->ia_netbroadcast.s_addr =
 779                         htonl(ia->ia_net | ~ ia->ia_netmask);
 780         } else if (ifp->if_flags & IFF_LOOPBACK) {
 781                 ia->ia_dstaddr = ia->ia_addr;
 782                 flags |= RTF_HOST;
 783         } else if (ifp->if_flags & IFF_POINTOPOINT) {
 784                 if (ia->ia_dstaddr.sin_family != AF_INET)
 785                         return (0);
 786                 flags |= RTF_HOST;
 787         }
 788         if ((error = in_addprefix(ia, flags)) != 0)
 789                 return (error);
 790
 791         return (error);
 792 }
 793
 794 #define rtinitflags(x) \
 795         ((((x)->ia_ifp->if_flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) != 0) \
 796             ? RTF_HOST : 0)
 797 /*
 798  * Check if we have a route for the given prefix already or add one accordingly.
 799  */
 800 static int
 801 in_addprefix(struct in_ifaddr *target, int flags)
 802 {
 803         struct in_ifaddr *ia;
 804         struct in_addr prefix, mask, p, m;
 805         int error;
 806
 807         if ((flags & RTF_HOST) != 0) {
 808                 prefix = target->ia_dstaddr.sin_addr;
 809                 mask.s_addr = 0;
 810         } else {
 811                 prefix = target->ia_addr.sin_addr;
 812                 mask = target->ia_sockmask.sin_addr;
 813                 prefix.s_addr &= mask.s_addr;
 814         }
 815
 816         TAILQ_FOREACH(ia, &in_ifaddrhead, ia_link) {
 817                 if (rtinitflags(ia)) {
 818                         p = ia->ia_addr.sin_addr;
 819
 820                         if (prefix.s_addr != p.s_addr)
 821                                 continue;
 822                 } else {
 823                         p = ia->ia_addr.sin_addr;
 824                         m = ia->ia_sockmask.sin_addr;
 825                         p.s_addr &= m.s_addr;
 826
 827                         if (prefix.s_addr != p.s_addr ||
 828                             mask.s_addr != m.s_addr)
 829                                 continue;
 830                 }
 831
 832                 /*
 833                  * If we got a matching prefix route inserted by other
 834                  * interface address, we are done here.
 835                  */
 836                 if (ia->ia_flags & IFA_ROUTE) {
 837                         if (sameprefixcarponly &&
 838                             target->ia_ifp->if_type != IFT_CARP &&
 839                             ia->ia_ifp->if_type != IFT_CARP)
 840                                 return (EEXIST);
 841                         else
 842                                 return (0);
 843                 }
 844         }
 845
 846         /*
 847          * No-one seem to have this prefix route, so we try to insert it.
 848          */
 849         error = rtinit(&target->ia_ifa, (int)RTM_ADD, flags);
 850         if (!error)
 851                 target->ia_flags |= IFA_ROUTE;
 852         return error;
 853 }
 854
 855 /*
 856  * If there is no other address in the system that can serve a route to the
 857  * same prefix, remove the route.  Hand over the route to the new address
 858  * otherwise.
 859  */
 860 static int
 861 in_scrubprefix(struct in_ifaddr *target)
 862 {
 863         struct in_ifaddr *ia;
 864         struct in_addr prefix, mask, p;
 865         int error;
 866
 867         if ((target->ia_flags & IFA_ROUTE) == 0)
 868                 return 0;
 869
 870         if (rtinitflags(target))
 871                 prefix = target->ia_dstaddr.sin_addr;
 872         else {
 873                 prefix = target->ia_addr.sin_addr;
 874                 mask = target->ia_sockmask.sin_addr;
 875                 prefix.s_addr &= mask.s_addr;
 876         }
 877
 878         TAILQ_FOREACH(ia, &in_ifaddrhead, ia_link) {
 879                 if (rtinitflags(ia))
 880                         p = ia->ia_dstaddr.sin_addr;
 881                 else {
 882                         p = ia->ia_addr.sin_addr;
 883                         p.s_addr &= ia->ia_sockmask.sin_addr.s_addr;
 884                 }
 885
 886                 if (prefix.s_addr != p.s_addr)
 887                         continue;
 888
 889                 /*
 890                  * If we got a matching prefix address, move IFA_ROUTE and
 891                  * the route itself to it.  Make sure that routing daemons
 892                  * get a heads-up.
 893                  *
 894                  * XXX: a special case for carp(4) interface
 895                  */
 896                 if ((ia->ia_flags & IFA_ROUTE) == 0
 897 #ifdef DEV_CARP
 898                     && (ia->ia_ifp->if_type != IFT_CARP)
 899 #endif
 900                                                         ) {
 901                         rtinit(&(target->ia_ifa), (int)RTM_DELETE,
 902                             rtinitflags(target));
 903                         target->ia_flags &= ~IFA_ROUTE;
 904
 905                         error = rtinit(&ia->ia_ifa, (int)RTM_ADD,
 906                             rtinitflags(ia) | RTF_UP);
 907                         if (error == 0)
 908                                 ia->ia_flags |= IFA_ROUTE;
 909                         return error;
 910                 }
 911         }
 912
 913         /*
 914          * As no-one seem to have this prefix, we can remove the route.
 915          */
 916         rtinit(&(target->ia_ifa), (int)RTM_DELETE, rtinitflags(target));
 917         target->ia_flags &= ~IFA_ROUTE;
 918         return 0;
 919 }
 920
 921 #undef rtinitflags
 922
 923 /*
 924  * Return 1 if the address might be a local broadcast address.
 925  */
 926 int
 927 in_broadcast(struct in_addr in, struct ifnet *ifp)
 928 {
 929         register struct ifaddr *ifa;
 930         u_long t;
 931
 932         if (in.s_addr == INADDR_BROADCAST ||
 933             in.s_addr == INADDR_ANY)
 934                 return 1;
 935         if ((ifp->if_flags & IFF_BROADCAST) == 0)
 936                 return 0;
 937         t = ntohl(in.s_addr);
 938         /*
 939          * Look through the list of addresses for a match
 940          * with a broadcast address.
 941          */
 942 #define ia ((struct in_ifaddr *)ifa)
 943         TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
 944                 if (ifa->ifa_addr->sa_family == AF_INET &&
 945                     (in.s_addr == ia->ia_broadaddr.sin_addr.s_addr ||
 946                      in.s_addr == ia->ia_netbroadcast.s_addr ||
 947                      /*
 948                       * Check for old-style (host 0) broadcast.
 949                       */
 950                      t == ia->ia_subnet || t == ia->ia_net) &&
 951                      /*
 952                       * Check for an all one subnetmask. These
 953                       * only exist when an interface gets a secondary
 954                       * address.
 955                       */
 956                      ia->ia_subnetmask != (u_long)0xffffffff)
 957                             return 1;
 958         return (0);
 959 #undef ia
 960 }
 961
 962 /*
 963  * Delete all IPv4 multicast address records, and associated link-layer
 964  * multicast address records, associated with ifp.
 965  */
 966 static void
 967 in_purgemaddrs(struct ifnet *ifp)
 968 {
 969         struct in_multi *inm;
 970         struct in_multi *oinm;
 971
 972 #ifdef DIAGNOSTIC
 973         printf("%s: purging ifp %p\n", __func__, ifp);
 974 #endif
 975         IFF_LOCKGIANT(ifp);
 976         IN_MULTI_LOCK();
 977         LIST_FOREACH_SAFE(inm, &in_multihead, inm_link, oinm) {
 978                 if (inm->inm_ifp == ifp)
 979                         in_delmulti_locked(inm);
 980         }
 981         IN_MULTI_UNLOCK();
 982         IFF_UNLOCKGIANT(ifp);
 983 }
 984
 985 /*
 986  * On interface removal, clean up IPv4 data structures hung off of the ifnet.
 987  */
 988 void
 989 in_ifdetach(struct ifnet *ifp)
 990 {
 991
 992         in_pcbpurgeif0(&ripcbinfo, ifp);
 993         in_pcbpurgeif0(&udbinfo, ifp);
 994         in_purgemaddrs(ifp);
 995 }