1 /* 2 * Copyright (c) 1982, 1986, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)in.c 8.2 (Berkeley) 11/15/93 34 * $Id: in.c,v 1.8 1994/12/22 21:56:22 wollman Exp $ 35 */ 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/ioctl.h> 40 #include <sys/errno.h> 41 #include <sys/malloc.h> 42 #include <sys/socket.h> 43 #include <sys/socketvar.h> 44 45 #include <net/if.h> 46 #include <net/route.h> 47 48 #include <netinet/in_systm.h> 49 #include <netinet/in.h> 50 #include <netinet/in_var.h> 51 #include <netinet/if_ether.h> 52 53 #include <netinet/igmp_var.h> 54 55 /* 56 * Return the network number from an internet address. 57 */ 58 u_long 59 in_netof(in) 60 struct in_addr in; 61 { 62 register u_long i = ntohl(in.s_addr); 63 register u_long net; 64 register struct in_ifaddr *ia; 65 66 if (IN_CLASSA(i)) 67 net = i & IN_CLASSA_NET; 68 else if (IN_CLASSB(i)) 69 net = i & IN_CLASSB_NET; 70 else if (IN_CLASSC(i)) 71 net = i & IN_CLASSC_NET; 72 else if (IN_CLASSD(i)) 73 net = i & IN_CLASSD_NET; 74 else 75 return (0); 76 77 /* 78 * Check whether network is a subnet; 79 * if so, return subnet number. 80 */ 81 for (ia = in_ifaddr; ia; ia = ia->ia_next) 82 if (net == ia->ia_net) 83 return (i & ia->ia_subnetmask); 84 return (net); 85 } 86 87 #ifndef SUBNETSARELOCAL 88 #define SUBNETSARELOCAL 1 89 #endif 90 int subnetsarelocal = SUBNETSARELOCAL; 91 /* 92 * Return 1 if an internet address is for a ``local'' host 93 * (one to which we have a connection). If subnetsarelocal 94 * is true, this includes other subnets of the local net. 95 * Otherwise, it includes only the directly-connected (sub)nets. 96 */ 97 int 98 in_localaddr(in) 99 struct in_addr in; 100 { 101 register u_long i = ntohl(in.s_addr); 102 register struct in_ifaddr *ia; 103 104 if (subnetsarelocal) { 105 for (ia = in_ifaddr; ia; ia = ia->ia_next) 106 if ((i & ia->ia_netmask) == ia->ia_net) 107 return (1); 108 } else { 109 for (ia = in_ifaddr; ia; ia = ia->ia_next) 110 if ((i & ia->ia_subnetmask) == ia->ia_subnet) 111 return (1); 112 } 113 return (0); 114 } 115 116 /* 117 * Determine whether an IP address is in a reserved set of addresses 118 * that may not be forwarded, or whether datagrams to that destination 119 * may be forwarded. 120 */ 121 int 122 in_canforward(in) 123 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)) 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 void 142 in_socktrim(ap) 143 struct sockaddr_in *ap; 144 { 145 register char *cplim = (char *) &ap->sin_addr; 146 register char *cp = (char *) (&ap->sin_addr + 1); 147 148 ap->sin_len = 0; 149 while (--cp >= cplim) 150 if (*cp) { 151 (ap)->sin_len = cp - (char *) (ap) + 1; 152 break; 153 } 154 } 155 156 int in_interfaces; /* number of external internet interfaces */ 157 extern struct ifnet loif; 158 159 /* 160 * Generic internet control operations (ioctl's). 161 * Ifp is 0 if not an interface-specific ioctl. 162 */ 163 /* ARGSUSED */ 164 int 165 in_control(so, cmd, data, ifp) 166 struct socket *so; 167 int cmd; 168 caddr_t data; 169 register struct ifnet *ifp; 170 { 171 register struct ifreq *ifr = (struct ifreq *)data; 172 register struct in_ifaddr *ia = 0; 173 register struct ifaddr *ifa; 174 struct in_ifaddr *oia; 175 struct in_aliasreq *ifra = (struct in_aliasreq *)data; 176 struct sockaddr_in oldaddr; 177 int error, hostIsNew, maskIsNew; 178 u_long i; 179 180 /* 181 * Find address for this interface, if it exists. 182 */ 183 if (ifp) 184 for (ia = in_ifaddr; ia; ia = ia->ia_next) 185 if (ia->ia_ifp == ifp) 186 break; 187 188 switch (cmd) { 189 190 case SIOCAIFADDR: 191 case SIOCDIFADDR: 192 if (ifra->ifra_addr.sin_family == AF_INET) 193 for (oia = ia; ia; ia = ia->ia_next) { 194 if (ia->ia_ifp == ifp && 195 ia->ia_addr.sin_addr.s_addr == 196 ifra->ifra_addr.sin_addr.s_addr) 197 break; 198 } 199 if (cmd == SIOCDIFADDR && ia == 0) 200 return (EADDRNOTAVAIL); 201 /* FALLTHROUGH */ 202 case SIOCSIFADDR: 203 case SIOCSIFNETMASK: 204 case SIOCSIFDSTADDR: 205 if ((so->so_state & SS_PRIV) == 0) 206 return (EPERM); 207 208 if (ifp == 0) 209 panic("in_control"); 210 if (ia == (struct in_ifaddr *)0) { 211 oia = (struct in_ifaddr *) 212 malloc(sizeof *oia, M_IFADDR, M_WAITOK); 213 if (oia == (struct in_ifaddr *)NULL) 214 return (ENOBUFS); 215 bzero((caddr_t)oia, sizeof *oia); 216 ia = in_ifaddr; 217 if (ia) { 218 for ( ; ia->ia_next; ia = ia->ia_next) 219 continue; 220 ia->ia_next = oia; 221 } else 222 in_ifaddr = oia; 223 ia = oia; 224 ifa = ifp->if_addrlist; 225 if (ifa) { 226 for ( ; ifa->ifa_next; ifa = ifa->ifa_next) 227 continue; 228 ifa->ifa_next = (struct ifaddr *) ia; 229 } else 230 ifp->if_addrlist = (struct ifaddr *) ia; 231 ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr; 232 ia->ia_ifa.ifa_dstaddr 233 = (struct sockaddr *)&ia->ia_dstaddr; 234 ia->ia_ifa.ifa_netmask 235 = (struct sockaddr *)&ia->ia_sockmask; 236 ia->ia_sockmask.sin_len = 8; 237 if (ifp->if_flags & IFF_BROADCAST) { 238 ia->ia_broadaddr.sin_len = sizeof(ia->ia_addr); 239 ia->ia_broadaddr.sin_family = AF_INET; 240 } 241 ia->ia_ifp = ifp; 242 if (ifp != &loif) 243 in_interfaces++; 244 } 245 break; 246 247 case SIOCSIFBRDADDR: 248 if ((so->so_state & SS_PRIV) == 0) 249 return (EPERM); 250 /* FALLTHROUGH */ 251 252 case SIOCGIFADDR: 253 case SIOCGIFNETMASK: 254 case SIOCGIFDSTADDR: 255 case SIOCGIFBRDADDR: 256 if (ia == (struct in_ifaddr *)0) 257 return (EADDRNOTAVAIL); 258 break; 259 } 260 switch (cmd) { 261 262 case SIOCGIFADDR: 263 *((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_addr; 264 break; 265 266 case SIOCGIFBRDADDR: 267 if ((ifp->if_flags & IFF_BROADCAST) == 0) 268 return (EINVAL); 269 *((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_broadaddr; 270 break; 271 272 case SIOCGIFDSTADDR: 273 if ((ifp->if_flags & IFF_POINTOPOINT) == 0) 274 return (EINVAL); 275 *((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_dstaddr; 276 break; 277 278 case SIOCGIFNETMASK: 279 *((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_sockmask; 280 break; 281 282 case SIOCSIFDSTADDR: 283 if ((ifp->if_flags & IFF_POINTOPOINT) == 0) 284 return (EINVAL); 285 oldaddr = ia->ia_dstaddr; 286 ia->ia_dstaddr = *(struct sockaddr_in *)&ifr->ifr_dstaddr; 287 if (ifp->if_ioctl && (error = (*ifp->if_ioctl) 288 (ifp, SIOCSIFDSTADDR, (caddr_t)ia))) { 289 ia->ia_dstaddr = oldaddr; 290 return (error); 291 } 292 if (ia->ia_flags & IFA_ROUTE) { 293 ia->ia_ifa.ifa_dstaddr = (struct sockaddr *)&oldaddr; 294 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST); 295 ia->ia_ifa.ifa_dstaddr = 296 (struct sockaddr *)&ia->ia_dstaddr; 297 rtinit(&(ia->ia_ifa), (int)RTM_ADD, RTF_HOST|RTF_UP); 298 } 299 break; 300 301 case SIOCSIFBRDADDR: 302 if ((ifp->if_flags & IFF_BROADCAST) == 0) 303 return (EINVAL); 304 ia->ia_broadaddr = *(struct sockaddr_in *)&ifr->ifr_broadaddr; 305 break; 306 307 case SIOCSIFADDR: 308 return (in_ifinit(ifp, ia, 309 (struct sockaddr_in *) &ifr->ifr_addr, 1)); 310 311 case SIOCSIFNETMASK: 312 i = ifra->ifra_addr.sin_addr.s_addr; 313 ia->ia_subnetmask = ntohl(ia->ia_sockmask.sin_addr.s_addr = i); 314 break; 315 316 case SIOCAIFADDR: 317 maskIsNew = 0; 318 hostIsNew = 1; 319 error = 0; 320 if (ia->ia_addr.sin_family == AF_INET) { 321 if (ifra->ifra_addr.sin_len == 0) { 322 ifra->ifra_addr = ia->ia_addr; 323 hostIsNew = 0; 324 } else if (ifra->ifra_addr.sin_addr.s_addr == 325 ia->ia_addr.sin_addr.s_addr) 326 hostIsNew = 0; 327 } 328 if (ifra->ifra_mask.sin_len) { 329 in_ifscrub(ifp, ia); 330 ia->ia_sockmask = ifra->ifra_mask; 331 ia->ia_subnetmask = 332 ntohl(ia->ia_sockmask.sin_addr.s_addr); 333 maskIsNew = 1; 334 } 335 if ((ifp->if_flags & IFF_POINTOPOINT) && 336 (ifra->ifra_dstaddr.sin_family == AF_INET)) { 337 in_ifscrub(ifp, ia); 338 ia->ia_dstaddr = ifra->ifra_dstaddr; 339 maskIsNew = 1; /* We lie; but the effect's the same */ 340 } 341 if (ifra->ifra_addr.sin_family == AF_INET && 342 (hostIsNew || maskIsNew)) 343 error = in_ifinit(ifp, ia, &ifra->ifra_addr, 0); 344 if ((ifp->if_flags & IFF_BROADCAST) && 345 (ifra->ifra_broadaddr.sin_family == AF_INET)) 346 ia->ia_broadaddr = ifra->ifra_broadaddr; 347 return (error); 348 349 case SIOCDIFADDR: 350 in_ifscrub(ifp, ia); 351 if ((ifa = ifp->if_addrlist) == (struct ifaddr *)ia) 352 ifp->if_addrlist = ifa->ifa_next; 353 else { 354 while (ifa->ifa_next && 355 (ifa->ifa_next != (struct ifaddr *)ia)) 356 ifa = ifa->ifa_next; 357 if (ifa->ifa_next) 358 ifa->ifa_next = ((struct ifaddr *)ia)->ifa_next; 359 else 360 printf("Couldn't unlink inifaddr from ifp\n"); 361 } 362 oia = ia; 363 if (oia == (ia = in_ifaddr)) 364 in_ifaddr = ia->ia_next; 365 else { 366 while (ia->ia_next && (ia->ia_next != oia)) 367 ia = ia->ia_next; 368 if (ia->ia_next) 369 ia->ia_next = oia->ia_next; 370 else 371 printf("Didn't unlink inifadr from list\n"); 372 } 373 IFAFREE((&oia->ia_ifa)); 374 break; 375 376 default: 377 if (ifp == 0 || ifp->if_ioctl == 0) 378 return (EOPNOTSUPP); 379 return ((*ifp->if_ioctl)(ifp, cmd, data)); 380 } 381 return (0); 382 } 383 384 /* 385 * Delete any existing route for an interface. 386 */ 387 void 388 in_ifscrub(ifp, ia) 389 register struct ifnet *ifp; 390 register struct in_ifaddr *ia; 391 { 392 393 if ((ia->ia_flags & IFA_ROUTE) == 0) 394 return; 395 if (ifp->if_flags & (IFF_LOOPBACK|IFF_POINTOPOINT)) 396 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST); 397 else 398 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, 0); 399 ia->ia_flags &= ~IFA_ROUTE; 400 } 401 402 /* 403 * Initialize an interface's internet address 404 * and routing table entry. 405 */ 406 int 407 in_ifinit(ifp, ia, sin, scrub) 408 register struct ifnet *ifp; 409 register struct in_ifaddr *ia; 410 struct sockaddr_in *sin; 411 int scrub; 412 { 413 register u_long i = ntohl(sin->sin_addr.s_addr); 414 struct sockaddr_in oldaddr; 415 int s = splimp(), flags = RTF_UP, error; 416 417 oldaddr = ia->ia_addr; 418 ia->ia_addr = *sin; 419 /* 420 * Give the interface a chance to initialize 421 * if this is its first address, 422 * and to validate the address if necessary. 423 */ 424 if (ifp->if_ioctl && 425 (error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia))) { 426 splx(s); 427 ia->ia_addr = oldaddr; 428 return (error); 429 } 430 splx(s); 431 if (scrub) { 432 ia->ia_ifa.ifa_addr = (struct sockaddr *)&oldaddr; 433 in_ifscrub(ifp, ia); 434 ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr; 435 } 436 if (IN_CLASSA(i)) 437 ia->ia_netmask = IN_CLASSA_NET; 438 else if (IN_CLASSB(i)) 439 ia->ia_netmask = IN_CLASSB_NET; 440 else 441 ia->ia_netmask = IN_CLASSC_NET; 442 /* 443 * The subnet mask usually includes at least the standard network part, 444 * but may may be smaller in the case of supernetting. 445 * If it is set, we believe it. 446 */ 447 if (ia->ia_subnetmask == 0) { 448 ia->ia_subnetmask = ia->ia_netmask; 449 ia->ia_sockmask.sin_addr.s_addr = htonl(ia->ia_subnetmask); 450 } else 451 ia->ia_netmask &= ia->ia_subnetmask; 452 ia->ia_net = i & ia->ia_netmask; 453 ia->ia_subnet = i & ia->ia_subnetmask; 454 in_socktrim(&ia->ia_sockmask); 455 /* 456 * Add route for the network. 457 */ 458 ia->ia_ifa.ifa_metric = ifp->if_metric; 459 if (ifp->if_flags & IFF_BROADCAST) { 460 ia->ia_broadaddr.sin_addr.s_addr = 461 htonl(ia->ia_subnet | ~ia->ia_subnetmask); 462 ia->ia_netbroadcast.s_addr = 463 htonl(ia->ia_net | ~ ia->ia_netmask); 464 } else if (ifp->if_flags & IFF_LOOPBACK) { 465 ia->ia_ifa.ifa_dstaddr = ia->ia_ifa.ifa_addr; 466 flags |= RTF_HOST; 467 } else if (ifp->if_flags & IFF_POINTOPOINT) { 468 if (ia->ia_dstaddr.sin_family != AF_INET) 469 return (0); 470 flags |= RTF_HOST; 471 } 472 if ((error = rtinit(&(ia->ia_ifa), (int)RTM_ADD, flags)) == 0) 473 ia->ia_flags |= IFA_ROUTE; 474 /* 475 * If the interface supports multicast, join the "all hosts" 476 * multicast group on that interface. 477 */ 478 if (ifp->if_flags & IFF_MULTICAST) { 479 struct in_addr addr; 480 481 addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP); 482 in_addmulti(&addr, ifp); 483 } 484 return (error); 485 } 486 487 488 /* 489 * Return 1 if the address might be a local broadcast address. 490 */ 491 int 492 in_broadcast(in, ifp) 493 struct in_addr in; 494 struct ifnet *ifp; 495 { 496 register struct ifaddr *ifa; 497 u_long t; 498 499 if (in.s_addr == INADDR_BROADCAST || 500 in.s_addr == INADDR_ANY) 501 return 1; 502 if ((ifp->if_flags & IFF_BROADCAST) == 0) 503 return 0; 504 t = ntohl(in.s_addr); 505 /* 506 * Look through the list of addresses for a match 507 * with a broadcast address. 508 */ 509 #define ia ((struct in_ifaddr *)ifa) 510 for (ifa = ifp->if_addrlist; ifa; ifa = ifa->ifa_next) 511 if (ifa->ifa_addr->sa_family == AF_INET && 512 (in.s_addr == ia->ia_broadaddr.sin_addr.s_addr || 513 in.s_addr == ia->ia_netbroadcast.s_addr || 514 /* 515 * Check for old-style (host 0) broadcast. 516 */ 517 t == ia->ia_subnet || t == ia->ia_net)) 518 return 1; 519 return (0); 520 #undef ia 521 } 522 /* 523 * Add an address to the list of IP multicast addresses for a given interface. 524 */ 525 struct in_multi * 526 in_addmulti(ap, ifp) 527 register struct in_addr *ap; 528 register struct ifnet *ifp; 529 { 530 register struct in_multi *inm; 531 struct ifreq ifr; 532 struct in_ifaddr *ia; 533 int s = splnet(); 534 535 /* 536 * See if address already in list. 537 */ 538 IN_LOOKUP_MULTI(*ap, ifp, inm); 539 if (inm != NULL) { 540 /* 541 * Found it; just increment the reference count. 542 */ 543 ++inm->inm_refcount; 544 } 545 else { 546 /* 547 * New address; allocate a new multicast record 548 * and link it into the interface's multicast list. 549 */ 550 inm = (struct in_multi *)malloc(sizeof(*inm), 551 M_IPMADDR, M_NOWAIT); 552 if (inm == NULL) { 553 splx(s); 554 return (NULL); 555 } 556 inm->inm_addr = *ap; 557 inm->inm_ifp = ifp; 558 inm->inm_refcount = 1; 559 IFP_TO_IA(ifp, ia); 560 if (ia == NULL) { 561 free(inm, M_IPMADDR); 562 splx(s); 563 return (NULL); 564 } 565 inm->inm_ia = ia; 566 inm->inm_next = ia->ia_multiaddrs; 567 ia->ia_multiaddrs = inm; 568 /* 569 * Ask the network driver to update its multicast reception 570 * filter appropriately for the new address. 571 */ 572 ((struct sockaddr_in *)&ifr.ifr_addr)->sin_family = AF_INET; 573 ((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr = *ap; 574 if ((ifp->if_ioctl == NULL) || 575 (*ifp->if_ioctl)(ifp, SIOCADDMULTI,(caddr_t)&ifr) != 0) { 576 ia->ia_multiaddrs = inm->inm_next; 577 free(inm, M_IPMADDR); 578 splx(s); 579 return (NULL); 580 } 581 /* 582 * Let IGMP know that we have joined a new IP multicast group. 583 */ 584 igmp_joingroup(inm); 585 } 586 splx(s); 587 return (inm); 588 } 589 590 /* 591 * Delete a multicast address record. 592 */ 593 void 594 in_delmulti(inm) 595 register struct in_multi *inm; 596 { 597 register struct in_multi **p; 598 struct ifreq ifr; 599 int s = splnet(); 600 601 if (--inm->inm_refcount == 0) { 602 /* 603 * No remaining claims to this record; let IGMP know that 604 * we are leaving the multicast group. 605 */ 606 igmp_leavegroup(inm); 607 /* 608 * Unlink from list. 609 */ 610 for (p = &inm->inm_ia->ia_multiaddrs; 611 *p != inm; 612 p = &(*p)->inm_next) 613 continue; 614 *p = (*p)->inm_next; 615 /* 616 * Notify the network driver to update its multicast reception 617 * filter. 618 */ 619 ((struct sockaddr_in *)&(ifr.ifr_addr))->sin_family = AF_INET; 620 ((struct sockaddr_in *)&(ifr.ifr_addr))->sin_addr = 621 inm->inm_addr; 622 (*inm->inm_ifp->if_ioctl)(inm->inm_ifp, SIOCDELMULTI, 623 (caddr_t)&ifr); 624 free(inm, M_IPMADDR); 625 } 626 splx(s); 627 } 628