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