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/jail.h>
  45 #include <sys/kernel.h>
  46 #include <sys/proc.h>
  47 #include <sys/sysctl.h>
  48
  49 #include <net/if.h>
  50 #include <net/if_types.h>
  51 #include <net/route.h>
  52
  53 #include <netinet/in.h>
  54 #include <netinet/in_var.h>
  55 #include <netinet/in_pcb.h>
  56 #include <netinet/ip_var.h>
  57
  58 static int in_mask2len(struct in_addr *);
  59 static void in_len2mask(struct in_addr *, int);
  60 static int in_lifaddr_ioctl(struct socket *, u_long, caddr_t,
  61         struct ifnet *, struct thread *);
  62
  63 static int      in_addprefix(struct in_ifaddr *, int);
  64 static int      in_scrubprefix(struct in_ifaddr *);
  65 static void     in_socktrim(struct sockaddr_in *);
  66 static int      in_ifinit(struct ifnet *,
  67             struct in_ifaddr *, struct sockaddr_in *, int);
  68 static void     in_purgemaddrs(struct ifnet *);
  69
  70 static int subnetsarelocal = 0;
  71 SYSCTL_INT(_net_inet_ip, OID_AUTO, subnets_are_local, CTLFLAG_RW,
  72         &subnetsarelocal, 0, "Treat all subnets as directly connected");
  73 static int sameprefixcarponly = 0;
  74 SYSCTL_INT(_net_inet_ip, OID_AUTO, same_prefix_carp_only, CTLFLAG_RW,
  75         &sameprefixcarponly, 0,
  76         "Refuse to create same prefixes on different interfaces");
  77
  78 extern struct inpcbinfo ripcbinfo;
  79 extern struct inpcbinfo udbinfo;
  80
  81 /*
  82  * Return 1 if an internet address is for a ``local'' host
  83  * (one to which we have a connection).  If subnetsarelocal
  84  * is true, this includes other subnets of the local net.
  85  * Otherwise, it includes only the directly-connected (sub)nets.
  86  */
  87 int
  88 in_localaddr(struct in_addr in)
  89 {
  90         register u_long i = ntohl(in.s_addr);
  91         register struct in_ifaddr *ia;
  92
  93         if (subnetsarelocal) {
  94                 TAILQ_FOREACH(ia, &in_ifaddrhead, ia_link)
  95                         if ((i & ia->ia_netmask) == ia->ia_net)
  96                                 return (1);
  97         } else {
  98                 TAILQ_FOREACH(ia, &in_ifaddrhead, ia_link)
  99                         if ((i & ia->ia_subnetmask) == ia->ia_subnet)
 100                                 return (1);
 101         }
 102         return (0);
 103 }
 104
 105 /*
 106  * Return 1 if an internet address is for the local host and configured
 107  * on one of its interfaces.
 108  */
 109 int
 110 in_localip(struct in_addr in)
 111 {
 112         struct in_ifaddr *ia;
 113
 114         LIST_FOREACH(ia, INADDR_HASH(in.s_addr), ia_hash) {
 115                 if (IA_SIN(ia)->sin_addr.s_addr == in.s_addr)
 116                         return 1;
 117         }
 118         return 0;
 119 }
 120
 121 /*
 122  * Determine whether an IP address is in a reserved set of addresses
 123  * that may not be forwarded, or whether datagrams to that destination
 124  * may be forwarded.
 125  */
 126 int
 127 in_canforward(struct in_addr in)
 128 {
 129         register u_long i = ntohl(in.s_addr);
 130         register u_long net;
 131
 132         if (IN_EXPERIMENTAL(i) || IN_MULTICAST(i) || IN_LINKLOCAL(i))
 133                 return (0);
 134         if (IN_CLASSA(i)) {
 135                 net = i & IN_CLASSA_NET;
 136                 if (net == 0 || net == (IN_LOOPBACKNET << IN_CLASSA_NSHIFT))
 137                         return (0);
 138         }
 139         return (1);
 140 }
 141
 142 /*
 143  * Trim a mask in a sockaddr
 144  */
 145 static void
 146 in_socktrim(struct sockaddr_in *ap)
 147 {
 148     register char *cplim = (char *) &ap->sin_addr;
 149     register char *cp = (char *) (&ap->sin_addr + 1);
 150
 151     ap->sin_len = 0;
 152     while (--cp >= cplim)
 153         if (*cp) {
 154             (ap)->sin_len = cp - (char *) (ap) + 1;
 155             break;
 156         }
 157 }
 158
 159 static int
 160 in_mask2len(mask)
 161         struct in_addr *mask;
 162 {
 163         int x, y;
 164         u_char *p;
 165
 166         p = (u_char *)mask;
 167         for (x = 0; x < sizeof(*mask); x++) {
 168                 if (p[x] != 0xff)
 169                         break;
 170         }
 171         y = 0;
 172         if (x < sizeof(*mask)) {
 173                 for (y = 0; y < 8; y++) {
 174                         if ((p[x] & (0x80 >> y)) == 0)
 175                                 break;
 176                 }
 177         }
 178         return x * 8 + y;
 179 }
 180
 181 static void
 182 in_len2mask(struct in_addr *mask, int len)
 183 {
 184         int i;
 185         u_char *p;
 186
 187         p = (u_char *)mask;
 188         bzero(mask, sizeof(*mask));
 189         for (i = 0; i < len / 8; i++)
 190                 p[i] = 0xff;
 191         if (len % 8)
 192                 p[i] = (0xff00 >> (len % 8)) & 0xff;
 193 }
 194
 195 /*
 196  * Generic internet control operations (ioctl's).
 197  * Ifp is 0 if not an interface-specific ioctl.
 198  */
 199 /* ARGSUSED */
 200 int
 201 in_control(struct socket *so, u_long cmd, caddr_t data, struct ifnet *ifp,
 202     struct thread *td)
 203 {
 204         register struct ifreq *ifr = (struct ifreq *)data;
 205         register struct in_ifaddr *ia = 0, *iap;
 206         register struct ifaddr *ifa;
 207         struct in_addr allhosts_addr;
 208         struct in_addr dst;
 209         struct in_ifaddr *oia;
 210         struct in_aliasreq *ifra = (struct in_aliasreq *)data;
 211         struct sockaddr_in oldaddr;
 212         int error, hostIsNew, iaIsNew, maskIsNew, s;
 213         int iaIsFirst;
 214
 215         iaIsFirst = 0;
 216         iaIsNew = 0;
 217         allhosts_addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);
 218
 219         switch (cmd) {
 220         case SIOCALIFADDR:
 221                 if (td != NULL) {
 222                         error = priv_check(td, PRIV_NET_ADDIFADDR);
 223                         if (error)
 224                                 return (error);
 225                 }
 226                 if (!ifp)
 227                         return EINVAL;
 228                 return in_lifaddr_ioctl(so, cmd, data, ifp, td);
 229
 230         case SIOCDLIFADDR:
 231                 if (td != NULL) {
 232                         error = priv_check(td, PRIV_NET_DELIFADDR);
 233                         if (error)
 234                                 return (error);
 235                 }
 236                 if (!ifp)
 237                         return EINVAL;
 238                 return in_lifaddr_ioctl(so, cmd, data, ifp, td);
 239
 240         case SIOCGLIFADDR:
 241                 if (!ifp)
 242                         return EINVAL;
 243                 return in_lifaddr_ioctl(so, cmd, data, ifp, td);
 244         }
 245
 246         /*
 247          * Find address for this interface, if it exists.
 248          *
 249          * If an alias address was specified, find that one instead of
 250          * the first one on the interface, if possible.
 251          */
 252         if (ifp) {
 253                 dst = ((struct sockaddr_in *)&ifr->ifr_addr)->sin_addr;
 254                 LIST_FOREACH(iap, INADDR_HASH(dst.s_addr), ia_hash)
 255                         if (iap->ia_ifp == ifp &&
 256                             iap->ia_addr.sin_addr.s_addr == dst.s_addr) {
 257                                 if (td == NULL || prison_check_ip4(
 258                                     td->td_ucred, &dst) == 0)
 259                                         ia = iap;
 260                                 break;
 261                         }
 262                 if (ia == NULL)
 263                         TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
 264                                 iap = ifatoia(ifa);
 265                                 if (iap->ia_addr.sin_family == AF_INET) {
 266                                         if (td != NULL &&
 267                                             prison_check_ip4(td->td_ucred,
 268                                             &iap->ia_addr.sin_addr) != 0)
 269                                                 continue;
 270                                         ia = iap;
 271                                         break;
 272                                 }
 273                         }
 274                 if (ia == NULL)
 275                         iaIsFirst = 1;
 276         }
 277
 278         switch (cmd) {
 279
 280         case SIOCAIFADDR:
 281         case SIOCDIFADDR:
 282                 if (ifp == 0)
 283                         return (EADDRNOTAVAIL);
 284                 if (ifra->ifra_addr.sin_family == AF_INET) {
 285                         for (oia = ia; ia; ia = TAILQ_NEXT(ia, ia_link)) {
 286                                 if (ia->ia_ifp == ifp  &&
 287                                     ia->ia_addr.sin_addr.s_addr ==
 288                                     ifra->ifra_addr.sin_addr.s_addr)
 289                                         break;
 290                         }
 291                         if ((ifp->if_flags & IFF_POINTOPOINT)
 292                             && (cmd == SIOCAIFADDR)
 293                             && (ifra->ifra_dstaddr.sin_addr.s_addr
 294                                 == INADDR_ANY)) {
 295                                 return EDESTADDRREQ;
 296                         }
 297                 }
 298                 if (cmd == SIOCDIFADDR && ia == 0)
 299                         return (EADDRNOTAVAIL);
 300                 /* FALLTHROUGH */
 301         case SIOCSIFADDR:
 302         case SIOCSIFNETMASK:
 303         case SIOCSIFDSTADDR:
 304                 if (td != NULL) {
 305                         error = priv_check(td, (cmd == SIOCDIFADDR) ?
 306                             PRIV_NET_DELIFADDR : PRIV_NET_ADDIFADDR);
 307                         if (error)
 308                                 return (error);
 309                 }
 310
 311                 if (ifp == 0)
 312                         return (EADDRNOTAVAIL);
 313                 if (ia == (struct in_ifaddr *)0) {
 314                         ia = (struct in_ifaddr *)
 315                                 malloc(sizeof *ia, M_IFADDR, M_WAITOK | M_ZERO);
 316                         if (ia == (struct in_ifaddr *)NULL)
 317                                 return (ENOBUFS);
 318                         /*
 319                          * Protect from ipintr() traversing address list
 320                          * while we're modifying it.
 321                          */
 322                         s = splnet();
 323                         ifa = &ia->ia_ifa;
 324                         IFA_LOCK_INIT(ifa);
 325                         ifa->ifa_addr = (struct sockaddr *)&ia->ia_addr;
 326                         ifa->ifa_dstaddr = (struct sockaddr *)&ia->ia_dstaddr;
 327                         ifa->ifa_netmask = (struct sockaddr *)&ia->ia_sockmask;
 328                         ifa->ifa_refcnt = 1;
 329                         TAILQ_INSERT_TAIL(&ifp->if_addrhead, ifa, ifa_link);
 330
 331                         ia->ia_sockmask.sin_len = 8;
 332                         ia->ia_sockmask.sin_family = AF_INET;
 333                         if (ifp->if_flags & IFF_BROADCAST) {
 334                                 ia->ia_broadaddr.sin_len = sizeof(ia->ia_addr);
 335                                 ia->ia_broadaddr.sin_family = AF_INET;
 336                         }
 337                         ia->ia_ifp = ifp;
 338
 339                         TAILQ_INSERT_TAIL(&in_ifaddrhead, ia, ia_link);
 340                         splx(s);
 341                         iaIsNew = 1;
 342                 }
 343                 break;
 344
 345         case SIOCSIFBRDADDR:
 346                 if (td != NULL) {
 347                         error = priv_check(td, PRIV_NET_ADDIFADDR);
 348                         if (error)
 349                                 return (error);
 350                 }
 351                 /* FALLTHROUGH */
 352
 353         case SIOCGIFADDR:
 354         case SIOCGIFNETMASK:
 355         case SIOCGIFDSTADDR:
 356         case SIOCGIFBRDADDR:
 357                 if (ia == (struct in_ifaddr *)0)
 358                         return (EADDRNOTAVAIL);
 359                 break;
 360         }
 361         switch (cmd) {
 362
 363         case SIOCGIFADDR:
 364                 *((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_addr;
 365                 return (0);
 366
 367         case SIOCGIFBRDADDR:
 368                 if ((ifp->if_flags & IFF_BROADCAST) == 0)
 369                         return (EINVAL);
 370                 *((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_broadaddr;
 371                 return (0);
 372
 373         case SIOCGIFDSTADDR:
 374                 if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
 375                         return (EINVAL);
 376                 *((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_dstaddr;
 377                 return (0);
 378
 379         case SIOCGIFNETMASK:
 380                 *((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_sockmask;
 381                 return (0);
 382
 383         case SIOCSIFDSTADDR:
 384                 if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
 385                         return (EINVAL);
 386                 oldaddr = ia->ia_dstaddr;
 387                 ia->ia_dstaddr = *(struct sockaddr_in *)&ifr->ifr_dstaddr;
 388                 if (ifp->if_ioctl) {
 389                         IFF_LOCKGIANT(ifp);
 390                         error = (*ifp->if_ioctl)(ifp, SIOCSIFDSTADDR,
 391                             (caddr_t)ia);
 392                         IFF_UNLOCKGIANT(ifp);
 393                         if (error) {
 394                                 ia->ia_dstaddr = oldaddr;
 395                                 return (error);
 396                         }
 397                 }
 398                 if (ia->ia_flags & IFA_ROUTE) {
 399                         ia->ia_ifa.ifa_dstaddr = (struct sockaddr *)&oldaddr;
 400                         rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST);
 401                         ia->ia_ifa.ifa_dstaddr =
 402                                         (struct sockaddr *)&ia->ia_dstaddr;
 403                         rtinit(&(ia->ia_ifa), (int)RTM_ADD, RTF_HOST|RTF_UP);
 404                 }
 405                 return (0);
 406
 407         case SIOCSIFBRDADDR:
 408                 if ((ifp->if_flags & IFF_BROADCAST) == 0)
 409                         return (EINVAL);
 410                 ia->ia_broadaddr = *(struct sockaddr_in *)&ifr->ifr_broadaddr;
 411                 return (0);
 412
 413         case SIOCSIFADDR:
 414                 error = in_ifinit(ifp, ia,
 415                     (struct sockaddr_in *) &ifr->ifr_addr, 1);
 416                 if (error != 0 && iaIsNew)
 417                         break;
 418                 if (error == 0) {
 419                         if (iaIsFirst && (ifp->if_flags & IFF_MULTICAST) != 0)
 420                                 in_addmulti(&allhosts_addr, ifp);
 421                         EVENTHANDLER_INVOKE(ifaddr_event, ifp);
 422                 }
 423                 return (0);
 424
 425         case SIOCSIFNETMASK:
 426                 ia->ia_sockmask.sin_addr = ifra->ifra_addr.sin_addr;
 427                 ia->ia_subnetmask = ntohl(ia->ia_sockmask.sin_addr.s_addr);
 428                 return (0);
 429
 430         case SIOCAIFADDR:
 431                 maskIsNew = 0;
 432                 hostIsNew = 1;
 433                 error = 0;
 434                 if (ia->ia_addr.sin_family == AF_INET) {
 435                         if (ifra->ifra_addr.sin_len == 0) {
 436                                 ifra->ifra_addr = ia->ia_addr;
 437                                 hostIsNew = 0;
 438                         } else if (ifra->ifra_addr.sin_addr.s_addr ==
 439                                                ia->ia_addr.sin_addr.s_addr)
 440                                 hostIsNew = 0;
 441                 }
 442                 if (ifra->ifra_mask.sin_len) {
 443                         in_ifscrub(ifp, ia);
 444                         ia->ia_sockmask = ifra->ifra_mask;
 445                         ia->ia_sockmask.sin_family = AF_INET;
 446                         ia->ia_subnetmask =
 447                              ntohl(ia->ia_sockmask.sin_addr.s_addr);
 448                         maskIsNew = 1;
 449                 }
 450                 if ((ifp->if_flags & IFF_POINTOPOINT) &&
 451                     (ifra->ifra_dstaddr.sin_family == AF_INET)) {
 452                         in_ifscrub(ifp, ia);
 453                         ia->ia_dstaddr = ifra->ifra_dstaddr;
 454                         maskIsNew  = 1; /* We lie; but the effect's the same */
 455                 }
 456                 if (ifra->ifra_addr.sin_family == AF_INET &&
 457                     (hostIsNew || maskIsNew))
 458                         error = in_ifinit(ifp, ia, &ifra->ifra_addr, 0);
 459                 if (error != 0 && iaIsNew)
 460                         break;
 461
 462                 if ((ifp->if_flags & IFF_BROADCAST) &&
 463                     (ifra->ifra_broadaddr.sin_family == AF_INET))
 464                         ia->ia_broadaddr = ifra->ifra_broadaddr;
 465                 if (error == 0) {
 466                         if (iaIsFirst && (ifp->if_flags & IFF_MULTICAST) != 0)
 467                                 in_addmulti(&allhosts_addr, ifp);
 468                         EVENTHANDLER_INVOKE(ifaddr_event, ifp);
 469                 }
 470                 return (error);
 471
 472         case SIOCDIFADDR:
 473                 /*
 474                  * in_ifscrub kills the interface route.
 475                  */
 476                 in_ifscrub(ifp, ia);
 477                 /*
 478                  * in_ifadown gets rid of all the rest of
 479                  * the routes.  This is not quite the right
 480                  * thing to do, but at least if we are running
 481                  * a routing process they will come back.
 482                  */
 483                 in_ifadown(&ia->ia_ifa, 1);
 484                 EVENTHANDLER_INVOKE(ifaddr_event, ifp);
 485                 error = 0;
 486                 break;
 487
 488         default:
 489                 if (ifp == 0 || ifp->if_ioctl == 0)
 490                         return (EOPNOTSUPP);
 491                 IFF_LOCKGIANT(ifp);
 492                 error = (*ifp->if_ioctl)(ifp, cmd, data);
 493                 IFF_UNLOCKGIANT(ifp);
 494                 return (error);
 495         }
 496
 497         /*
 498          * Protect from ipintr() traversing address list while we're modifying
 499          * it.
 500          */
 501         s = splnet();
 502         TAILQ_REMOVE(&ifp->if_addrhead, &ia->ia_ifa, ifa_link);
 503         TAILQ_REMOVE(&in_ifaddrhead, ia, ia_link);
 504         if (ia->ia_addr.sin_family == AF_INET) {
 505                 LIST_REMOVE(ia, ia_hash);
 506                 /*
 507                  * If this is the last IPv4 address configured on this
 508                  * interface, leave the all-hosts group.
 509                  * XXX: This is quite ugly because of locking and structure.
 510                  */
 511                 oia = NULL;
 512                 IFP_TO_IA(ifp, oia);
 513                 if (oia == NULL) {
 514                         struct in_multi *inm;
 515
 516                         IFF_LOCKGIANT(ifp);
 517                         IN_MULTI_LOCK();
 518                         IN_LOOKUP_MULTI(allhosts_addr, ifp, inm);
 519                         if (inm != NULL)
 520                                 in_delmulti_locked(inm);
 521                         IN_MULTI_UNLOCK();
 522                         IFF_UNLOCKGIANT(ifp);
 523                 }
 524         }
 525         IFAFREE(&ia->ia_ifa);
 526         splx(s);
 527
 528         return (error);
 529 }
 530
 531 /*
 532  * SIOC[GAD]LIFADDR.
 533  *      SIOCGLIFADDR: get first address. (?!?)
 534  *      SIOCGLIFADDR with IFLR_PREFIX:
 535  *              get first address that matches the specified prefix.
 536  *      SIOCALIFADDR: add the specified address.
 537  *      SIOCALIFADDR with IFLR_PREFIX:
 538  *              EINVAL since we can't deduce hostid part of the address.
 539  *      SIOCDLIFADDR: delete the specified address.
 540  *      SIOCDLIFADDR with IFLR_PREFIX:
 541  *              delete the first address that matches the specified prefix.
 542  * return values:
 543  *      EINVAL on invalid parameters
 544  *      EADDRNOTAVAIL on prefix match failed/specified address not found
 545  *      other values may be returned from in_ioctl()
 546  */
 547 static int
 548 in_lifaddr_ioctl(struct socket *so, u_long cmd, caddr_t data,
 549     struct ifnet *ifp, struct thread *td)
 550 {
 551         struct if_laddrreq *iflr = (struct if_laddrreq *)data;
 552         struct ifaddr *ifa;
 553
 554         /* sanity checks */
 555         if (!data || !ifp) {
 556                 panic("invalid argument to in_lifaddr_ioctl");
 557                 /*NOTRECHED*/
 558         }
 559
 560         switch (cmd) {
 561         case SIOCGLIFADDR:
 562                 /* address must be specified on GET with IFLR_PREFIX */
 563                 if ((iflr->flags & IFLR_PREFIX) == 0)
 564                         break;
 565                 /*FALLTHROUGH*/
 566         case SIOCALIFADDR:
 567         case SIOCDLIFADDR:
 568                 /* address must be specified on ADD and DELETE */
 569                 if (iflr->addr.ss_family != AF_INET)
 570                         return EINVAL;
 571                 if (iflr->addr.ss_len != sizeof(struct sockaddr_in))
 572                         return EINVAL;
 573                 /* XXX need improvement */
 574                 if (iflr->dstaddr.ss_family
 575                  && iflr->dstaddr.ss_family != AF_INET)
 576                         return EINVAL;
 577                 if (iflr->dstaddr.ss_family
 578                  && iflr->dstaddr.ss_len != sizeof(struct sockaddr_in))
 579                         return EINVAL;
 580                 break;
 581         default: /*shouldn't happen*/
 582                 return EOPNOTSUPP;
 583         }
 584         if (sizeof(struct in_addr) * 8 < iflr->prefixlen)
 585                 return EINVAL;
 586
 587         switch (cmd) {
 588         case SIOCALIFADDR:
 589             {
 590                 struct in_aliasreq ifra;
 591
 592                 if (iflr->flags & IFLR_PREFIX)
 593                         return EINVAL;
 594
 595                 /* copy args to in_aliasreq, perform ioctl(SIOCAIFADDR_IN6). */
 596                 bzero(&ifra, sizeof(ifra));
 597                 bcopy(iflr->iflr_name, ifra.ifra_name,
 598                         sizeof(ifra.ifra_name));
 599
 600                 bcopy(&iflr->addr, &ifra.ifra_addr, iflr->addr.ss_len);
 601
 602                 if (iflr->dstaddr.ss_family) {  /*XXX*/
 603                         bcopy(&iflr->dstaddr, &ifra.ifra_dstaddr,
 604                                 iflr->dstaddr.ss_len);
 605                 }
 606
 607                 ifra.ifra_mask.sin_family = AF_INET;
 608                 ifra.ifra_mask.sin_len = sizeof(struct sockaddr_in);
 609                 in_len2mask(&ifra.ifra_mask.sin_addr, iflr->prefixlen);
 610
 611                 return in_control(so, SIOCAIFADDR, (caddr_t)&ifra, ifp, td);
 612             }
 613         case SIOCGLIFADDR:
 614         case SIOCDLIFADDR:
 615             {
 616                 struct in_ifaddr *ia;
 617                 struct in_addr mask, candidate, match;
 618                 struct sockaddr_in *sin;
 619
 620                 bzero(&mask, sizeof(mask));
 621                 bzero(&match, sizeof(match));
 622                 if (iflr->flags & IFLR_PREFIX) {
 623                         /* lookup a prefix rather than address. */
 624                         in_len2mask(&mask, iflr->prefixlen);
 625
 626                         sin = (struct sockaddr_in *)&iflr->addr;
 627                         match.s_addr = sin->sin_addr.s_addr;
 628                         match.s_addr &= mask.s_addr;
 629
 630                         /* if you set extra bits, that's wrong */
 631                         if (match.s_addr != sin->sin_addr.s_addr)
 632                                 return EINVAL;
 633
 634                 } else {
 635                         /* on getting an address, take the 1st match */
 636                         /* on deleting an address, do exact match */
 637                         if (cmd != SIOCGLIFADDR) {
 638                                 in_len2mask(&mask, 32);
 639                                 sin = (struct sockaddr_in *)&iflr->addr;
 640                                 match.s_addr = sin->sin_addr.s_addr;
 641                         }
 642                 }
 643
 644                 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
 645                         if (ifa->ifa_addr->sa_family != AF_INET6)
 646                                 continue;
 647                         if (match.s_addr == 0)
 648                                 break;
 649                         candidate.s_addr = ((struct sockaddr_in *)&ifa->ifa_addr)->sin_addr.s_addr;
 650                         candidate.s_addr &= mask.s_addr;
 651                         if (candidate.s_addr == match.s_addr)
 652                                 break;
 653                 }
 654                 if (!ifa)
 655                         return EADDRNOTAVAIL;
 656                 ia = (struct in_ifaddr *)ifa;
 657
 658                 if (cmd == SIOCGLIFADDR) {
 659                         /* fill in the if_laddrreq structure */
 660                         bcopy(&ia->ia_addr, &iflr->addr, ia->ia_addr.sin_len);
 661
 662                         if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
 663                                 bcopy(&ia->ia_dstaddr, &iflr->dstaddr,
 664                                         ia->ia_dstaddr.sin_len);
 665                         } else
 666                                 bzero(&iflr->dstaddr, sizeof(iflr->dstaddr));
 667
 668                         iflr->prefixlen =
 669                                 in_mask2len(&ia->ia_sockmask.sin_addr);
 670
 671                         iflr->flags = 0;        /*XXX*/
 672
 673                         return 0;
 674                 } else {
 675                         struct in_aliasreq ifra;
 676
 677                         /* fill in_aliasreq and do ioctl(SIOCDIFADDR_IN6) */
 678                         bzero(&ifra, sizeof(ifra));
 679                         bcopy(iflr->iflr_name, ifra.ifra_name,
 680                                 sizeof(ifra.ifra_name));
 681
 682                         bcopy(&ia->ia_addr, &ifra.ifra_addr,
 683                                 ia->ia_addr.sin_len);
 684                         if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
 685                                 bcopy(&ia->ia_dstaddr, &ifra.ifra_dstaddr,
 686                                         ia->ia_dstaddr.sin_len);
 687                         }
 688                         bcopy(&ia->ia_sockmask, &ifra.ifra_dstaddr,
 689                                 ia->ia_sockmask.sin_len);
 690
 691                         return in_control(so, SIOCDIFADDR, (caddr_t)&ifra,
 692                                           ifp, td);
 693                 }
 694             }
 695         }
 696
 697         return EOPNOTSUPP;      /*just for safety*/
 698 }
 699
 700 /*
 701  * Delete any existing route for an interface.
 702  */
 703 void
 704 in_ifscrub(struct ifnet *ifp, struct in_ifaddr *ia)
 705 {
 706
 707         in_scrubprefix(ia);
 708 }
 709
 710 /*
 711  * Initialize an interface's internet address
 712  * and routing table entry.
 713  */
 714 static int
 715 in_ifinit(struct ifnet *ifp, struct in_ifaddr *ia, struct sockaddr_in *sin,
 716     int scrub)
 717 {
 718         register u_long i = ntohl(sin->sin_addr.s_addr);
 719         struct sockaddr_in oldaddr;
 720         int s = splimp(), flags = RTF_UP, error = 0;
 721
 722         oldaddr = ia->ia_addr;
 723         if (oldaddr.sin_family == AF_INET)
 724                 LIST_REMOVE(ia, ia_hash);
 725         ia->ia_addr = *sin;
 726         if (ia->ia_addr.sin_family == AF_INET)
 727                 LIST_INSERT_HEAD(INADDR_HASH(ia->ia_addr.sin_addr.s_addr),
 728                     ia, ia_hash);
 729         /*
 730          * Give the interface a chance to initialize
 731          * if this is its first address,
 732          * and to validate the address if necessary.
 733          */
 734         if (ifp->if_ioctl) {
 735                 IFF_LOCKGIANT(ifp);
 736                 error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia);
 737                 IFF_UNLOCKGIANT(ifp);
 738                 if (error) {
 739                         splx(s);
 740                         /* LIST_REMOVE(ia, ia_hash) is done in in_control */
 741                         ia->ia_addr = oldaddr;
 742                         if (ia->ia_addr.sin_family == AF_INET)
 743                                 LIST_INSERT_HEAD(INADDR_HASH(
 744                                     ia->ia_addr.sin_addr.s_addr), ia, ia_hash);
 745                         else
 746                                 /*
 747                                  * If oldaddr family is not AF_INET (e.g.
 748                                  * interface has been just created) in_control
 749                                  * does not call LIST_REMOVE, and we end up
 750                                  * with bogus ia entries in hash
 751                                  */
 752                                 LIST_REMOVE(ia, ia_hash);
 753                         return (error);
 754                 }
 755         }
 756         splx(s);
 757         if (scrub) {
 758                 ia->ia_ifa.ifa_addr = (struct sockaddr *)&oldaddr;
 759                 in_ifscrub(ifp, ia);
 760                 ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr;
 761         }
 762         if (IN_CLASSA(i))
 763                 ia->ia_netmask = IN_CLASSA_NET;
 764         else if (IN_CLASSB(i))
 765                 ia->ia_netmask = IN_CLASSB_NET;
 766         else
 767                 ia->ia_netmask = IN_CLASSC_NET;
 768         /*
 769          * The subnet mask usually includes at least the standard network part,
 770          * but may may be smaller in the case of supernetting.
 771          * If it is set, we believe it.
 772          */
 773         if (ia->ia_subnetmask == 0) {
 774                 ia->ia_subnetmask = ia->ia_netmask;
 775                 ia->ia_sockmask.sin_addr.s_addr = htonl(ia->ia_subnetmask);
 776         } else
 777                 ia->ia_netmask &= ia->ia_subnetmask;
 778         ia->ia_net = i & ia->ia_netmask;
 779         ia->ia_subnet = i & ia->ia_subnetmask;
 780         in_socktrim(&ia->ia_sockmask);
 781 #ifdef DEV_CARP
 782         /*
 783          * XXX: carp(4) does not have interface route
 784          */
 785         if (ifp->if_type == IFT_CARP)
 786                 return (0);
 787 #endif
 788         /*
 789          * Add route for the network.
 790          */
 791         ia->ia_ifa.ifa_metric = ifp->if_metric;
 792         if (ifp->if_flags & IFF_BROADCAST) {
 793                 ia->ia_broadaddr.sin_addr.s_addr =
 794                         htonl(ia->ia_subnet | ~ia->ia_subnetmask);
 795                 ia->ia_netbroadcast.s_addr =
 796                         htonl(ia->ia_net | ~ ia->ia_netmask);
 797         } else if (ifp->if_flags & IFF_LOOPBACK) {
 798                 ia->ia_dstaddr = ia->ia_addr;
 799                 flags |= RTF_HOST;
 800         } else if (ifp->if_flags & IFF_POINTOPOINT) {
 801                 if (ia->ia_dstaddr.sin_family != AF_INET)
 802                         return (0);
 803                 flags |= RTF_HOST;
 804         }
 805         if ((error = in_addprefix(ia, flags)) != 0)
 806                 return (error);
 807
 808         return (error);
 809 }
 810
 811 #define rtinitflags(x) \
 812         ((((x)->ia_ifp->if_flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) != 0) \
 813             ? RTF_HOST : 0)
 814 /*
 815  * Check if we have a route for the given prefix already or add one accordingly.
 816  */
 817 static int
 818 in_addprefix(struct in_ifaddr *target, int flags)
 819 {
 820         struct in_ifaddr *ia;
 821         struct in_addr prefix, mask, p, m;
 822         int error;
 823
 824         if ((flags & RTF_HOST) != 0) {
 825                 prefix = target->ia_dstaddr.sin_addr;
 826                 mask.s_addr = 0;
 827         } else {
 828                 prefix = target->ia_addr.sin_addr;
 829                 mask = target->ia_sockmask.sin_addr;
 830                 prefix.s_addr &= mask.s_addr;
 831         }
 832
 833         TAILQ_FOREACH(ia, &in_ifaddrhead, ia_link) {
 834                 if (rtinitflags(ia)) {
 835                         p = ia->ia_addr.sin_addr;
 836
 837                         if (prefix.s_addr != p.s_addr)
 838                                 continue;
 839                 } else {
 840                         p = ia->ia_addr.sin_addr;
 841                         m = ia->ia_sockmask.sin_addr;
 842                         p.s_addr &= m.s_addr;
 843
 844                         if (prefix.s_addr != p.s_addr ||
 845                             mask.s_addr != m.s_addr)
 846                                 continue;
 847                 }
 848
 849                 /*
 850                  * If we got a matching prefix route inserted by other
 851                  * interface address, we are done here.
 852                  */
 853                 if (ia->ia_flags & IFA_ROUTE) {
 854                         if (sameprefixcarponly &&
 855                             target->ia_ifp->if_type != IFT_CARP &&
 856                             ia->ia_ifp->if_type != IFT_CARP)
 857                                 return (EEXIST);
 858                         else
 859                                 return (0);
 860                 }
 861         }
 862
 863         /*
 864          * No-one seem to have this prefix route, so we try to insert it.
 865          */
 866         error = rtinit(&target->ia_ifa, (int)RTM_ADD, flags);
 867         if (!error)
 868                 target->ia_flags |= IFA_ROUTE;
 869         return error;
 870 }
 871
 872 /*
 873  * If there is no other address in the system that can serve a route to the
 874  * same prefix, remove the route.  Hand over the route to the new address
 875  * otherwise.
 876  */
 877 static int
 878 in_scrubprefix(struct in_ifaddr *target)
 879 {
 880         struct in_ifaddr *ia;
 881         struct in_addr prefix, mask, p;
 882         int error;
 883
 884         if ((target->ia_flags & IFA_ROUTE) == 0)
 885                 return 0;
 886
 887         if (rtinitflags(target))
 888                 prefix = target->ia_dstaddr.sin_addr;
 889         else {
 890                 prefix = target->ia_addr.sin_addr;
 891                 mask = target->ia_sockmask.sin_addr;
 892                 prefix.s_addr &= mask.s_addr;
 893         }
 894
 895         TAILQ_FOREACH(ia, &in_ifaddrhead, ia_link) {
 896                 if (rtinitflags(ia))
 897                         p = ia->ia_dstaddr.sin_addr;
 898                 else {
 899                         p = ia->ia_addr.sin_addr;
 900                         p.s_addr &= ia->ia_sockmask.sin_addr.s_addr;
 901                 }
 902
 903                 if (prefix.s_addr != p.s_addr)
 904                         continue;
 905
 906                 /*
 907                  * If we got a matching prefix address, move IFA_ROUTE and
 908                  * the route itself to it.  Make sure that routing daemons
 909                  * get a heads-up.
 910                  *
 911                  * XXX: a special case for carp(4) interface
 912                  */
 913                 if ((ia->ia_flags & IFA_ROUTE) == 0
 914 #ifdef DEV_CARP
 915                     && (ia->ia_ifp->if_type != IFT_CARP)
 916 #endif
 917                                                         ) {
 918                         rtinit(&(target->ia_ifa), (int)RTM_DELETE,
 919                             rtinitflags(target));
 920                         target->ia_flags &= ~IFA_ROUTE;
 921
 922                         error = rtinit(&ia->ia_ifa, (int)RTM_ADD,
 923                             rtinitflags(ia) | RTF_UP);
 924                         if (error == 0)
 925                                 ia->ia_flags |= IFA_ROUTE;
 926                         return error;
 927                 }
 928         }
 929
 930         /*
 931          * As no-one seem to have this prefix, we can remove the route.
 932          */
 933         rtinit(&(target->ia_ifa), (int)RTM_DELETE, rtinitflags(target));
 934         target->ia_flags &= ~IFA_ROUTE;
 935         return 0;
 936 }
 937
 938 #undef rtinitflags
 939
 940 /*
 941  * Return 1 if the address might be a local broadcast address.
 942  */
 943 int
 944 in_broadcast(struct in_addr in, struct ifnet *ifp)
 945 {
 946         register struct ifaddr *ifa;
 947         u_long t;
 948
 949         if (in.s_addr == INADDR_BROADCAST ||
 950             in.s_addr == INADDR_ANY)
 951                 return 1;
 952         if ((ifp->if_flags & IFF_BROADCAST) == 0)
 953                 return 0;
 954         t = ntohl(in.s_addr);
 955         /*
 956          * Look through the list of addresses for a match
 957          * with a broadcast address.
 958          */
 959 #define ia ((struct in_ifaddr *)ifa)
 960         TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
 961                 if (ifa->ifa_addr->sa_family == AF_INET &&
 962                     (in.s_addr == ia->ia_broadaddr.sin_addr.s_addr ||
 963                      in.s_addr == ia->ia_netbroadcast.s_addr ||
 964                      /*
 965                       * Check for old-style (host 0) broadcast.
 966                       */
 967                      t == ia->ia_subnet || t == ia->ia_net) &&
 968                      /*
 969                       * Check for an all one subnetmask. These
 970                       * only exist when an interface gets a secondary
 971                       * address.
 972                       */
 973                      ia->ia_subnetmask != (u_long)0xffffffff)
 974                             return 1;
 975         return (0);
 976 #undef ia
 977 }
 978
 979 /*
 980  * Delete all IPv4 multicast address records, and associated link-layer
 981  * multicast address records, associated with ifp.
 982  */
 983 static void
 984 in_purgemaddrs(struct ifnet *ifp)
 985 {
 986         struct in_multi *inm;
 987         struct in_multi *oinm;
 988
 989 #ifdef DIAGNOSTIC
 990         printf("%s: purging ifp %p\n", __func__, ifp);
 991 #endif
 992         IFF_LOCKGIANT(ifp);
 993         IN_MULTI_LOCK();
 994         LIST_FOREACH_SAFE(inm, &in_multihead, inm_link, oinm) {
 995                 if (inm->inm_ifp == ifp)
 996                         in_delmulti_locked(inm);
 997         }
 998         IN_MULTI_UNLOCK();
 999         IFF_UNLOCKGIANT(ifp);
1000 }
1001
1002 /*
1003  * On interface removal, clean up IPv4 data structures hung off of the ifnet.
1004  */
1005 void
1006 in_ifdetach(struct ifnet *ifp)
1007 {
1008
1009         in_pcbpurgeif0(&ripcbinfo, ifp);
1010         in_pcbpurgeif0(&udbinfo, ifp);
1011         in_purgemaddrs(ifp);
1012 }