in.c revision 1.14
1 /* $NetBSD: in.c,v 1.14 1994/06/29 06:38:00 cgd Exp $ */ 2 3 /* 4 * Copyright (c) 1982, 1986, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)in.c 8.2 (Berkeley) 11/15/93 36 */ 37 38 #include <sys/param.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 "ether.h" 54 55 #ifdef INET 56 /* 57 * Return the network number from an internet address. 58 */ 59 u_long 60 in_netof(in) 61 struct in_addr in; 62 { 63 register u_long i = ntohl(in.s_addr); 64 register u_long net; 65 register struct in_ifaddr *ia; 66 67 if (IN_CLASSA(i)) 68 net = i & IN_CLASSA_NET; 69 else if (IN_CLASSB(i)) 70 net = i & IN_CLASSB_NET; 71 else if (IN_CLASSC(i)) 72 net = i & IN_CLASSC_NET; 73 else if (IN_CLASSD(i)) 74 net = i & IN_CLASSD_NET; 75 else 76 return (0); 77 78 /* 79 * Check whether network is a subnet; 80 * if so, return subnet number. 81 */ 82 for (ia = in_ifaddr; ia; ia = ia->ia_next) 83 if (net == ia->ia_net) 84 return (i & ia->ia_subnetmask); 85 return (net); 86 } 87 88 #ifndef SUBNETSARELOCAL 89 #define SUBNETSARELOCAL 1 90 #endif 91 int subnetsarelocal = SUBNETSARELOCAL; 92 /* 93 * Return 1 if an internet address is for a ``local'' host 94 * (one to which we have a connection). If subnetsarelocal 95 * is true, this includes other subnets of the local net. 96 * Otherwise, it includes only the directly-connected (sub)nets. 97 */ 98 int 99 in_localaddr(in) 100 struct in_addr in; 101 { 102 register u_long i = ntohl(in.s_addr); 103 register struct in_ifaddr *ia; 104 105 if (subnetsarelocal) { 106 for (ia = in_ifaddr; ia; ia = ia->ia_next) 107 if ((i & ia->ia_netmask) == ia->ia_net) 108 return (1); 109 } else { 110 for (ia = in_ifaddr; ia; ia = ia->ia_next) 111 if ((i & ia->ia_subnetmask) == ia->ia_subnet) 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(in) 124 struct in_addr in; 125 { 126 register u_long i = ntohl(in.s_addr); 127 register u_long net; 128 129 if (IN_EXPERIMENTAL(i) || IN_MULTICAST(i)) 130 return (0); 131 if (IN_CLASSA(i)) { 132 net = i & IN_CLASSA_NET; 133 if (net == 0 || net == (IN_LOOPBACKNET << IN_CLASSA_NSHIFT)) 134 return (0); 135 } 136 return (1); 137 } 138 139 /* 140 * Trim a mask in a sockaddr 141 */ 142 void 143 in_socktrim(ap) 144 struct sockaddr_in *ap; 145 { 146 register char *cplim = (char *) &ap->sin_addr; 147 register char *cp = (char *) (&ap->sin_addr + 1); 148 149 ap->sin_len = 0; 150 while (--cp > cplim) 151 if (*cp) { 152 (ap)->sin_len = cp - (char *) (ap) + 1; 153 break; 154 } 155 } 156 157 int in_interfaces; /* number of external internet interfaces */ 158 extern struct ifnet loif; 159 160 /* 161 * Generic internet control operations (ioctl's). 162 * Ifp is 0 if not an interface-specific ioctl. 163 */ 164 /* ARGSUSED */ 165 int 166 in_control(so, cmd, data, ifp) 167 struct socket *so; 168 int cmd; 169 caddr_t data; 170 register struct ifnet *ifp; 171 { 172 register struct ifreq *ifr = (struct ifreq *)data; 173 register struct in_ifaddr *ia = 0; 174 register struct ifaddr *ifa; 175 struct in_ifaddr *oia; 176 struct in_aliasreq *ifra = (struct in_aliasreq *)data; 177 struct sockaddr_in oldaddr; 178 int error, hostIsNew, maskIsNew; 179 u_long i; 180 181 /* 182 * Find address for this interface, if it exists. 183 */ 184 if (ifp) 185 for (ia = in_ifaddr; ia; ia = ia->ia_next) 186 if (ia->ia_ifp == ifp) 187 break; 188 189 switch (cmd) { 190 191 case SIOCAIFADDR: 192 case SIOCDIFADDR: 193 if (ifra->ifra_addr.sin_family == AF_INET) 194 for (oia = ia; ia; ia = ia->ia_next) { 195 if (ia->ia_ifp == ifp && 196 ia->ia_addr.sin_addr.s_addr == 197 ifra->ifra_addr.sin_addr.s_addr) 198 break; 199 } 200 if (cmd == SIOCDIFADDR && ia == 0) 201 return (EADDRNOTAVAIL); 202 /* FALLTHROUGH */ 203 case SIOCSIFADDR: 204 case SIOCSIFNETMASK: 205 case SIOCSIFDSTADDR: 206 if ((so->so_state & SS_PRIV) == 0) 207 return (EPERM); 208 209 if (ifp == 0) 210 panic("in_control"); 211 if (ia == (struct in_ifaddr *)0) { 212 oia = (struct in_ifaddr *) 213 malloc(sizeof *oia, M_IFADDR, M_WAITOK); 214 if (oia == (struct in_ifaddr *)NULL) 215 return (ENOBUFS); 216 bzero((caddr_t)oia, sizeof *oia); 217 if (ia = in_ifaddr) { 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 if (ifa = ifp->if_addrlist) { 225 for ( ; ifa->ifa_next; ifa = ifa->ifa_next) 226 continue; 227 ifa->ifa_next = (struct ifaddr *) ia; 228 } else 229 ifp->if_addrlist = (struct ifaddr *) ia; 230 ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr; 231 ia->ia_ifa.ifa_dstaddr 232 = (struct sockaddr *)&ia->ia_dstaddr; 233 ia->ia_ifa.ifa_netmask 234 = (struct sockaddr *)&ia->ia_sockmask; 235 ia->ia_sockmask.sin_len = 8; 236 if (ifp->if_flags & IFF_BROADCAST) { 237 ia->ia_broadaddr.sin_len = sizeof(ia->ia_addr); 238 ia->ia_broadaddr.sin_family = AF_INET; 239 } 240 ia->ia_ifp = ifp; 241 if (ifp != &loif) 242 in_interfaces++; 243 } 244 break; 245 246 case SIOCSIFBRDADDR: 247 if ((so->so_state & SS_PRIV) == 0) 248 return (EPERM); 249 /* FALLTHROUGH */ 250 251 case SIOCGIFADDR: 252 case SIOCGIFNETMASK: 253 case SIOCGIFDSTADDR: 254 case SIOCGIFBRDADDR: 255 if (ia == (struct in_ifaddr *)0) 256 return (EADDRNOTAVAIL); 257 break; 258 } 259 switch (cmd) { 260 261 case SIOCGIFADDR: 262 *((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_addr; 263 break; 264 265 case SIOCGIFBRDADDR: 266 if ((ifp->if_flags & IFF_BROADCAST) == 0) 267 return (EINVAL); 268 *((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_broadaddr; 269 break; 270 271 case SIOCGIFDSTADDR: 272 if ((ifp->if_flags & IFF_POINTOPOINT) == 0) 273 return (EINVAL); 274 *((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_dstaddr; 275 break; 276 277 case SIOCGIFNETMASK: 278 *((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_sockmask; 279 break; 280 281 case SIOCSIFDSTADDR: 282 if ((ifp->if_flags & IFF_POINTOPOINT) == 0) 283 return (EINVAL); 284 oldaddr = ia->ia_dstaddr; 285 ia->ia_dstaddr = *(struct sockaddr_in *)&ifr->ifr_dstaddr; 286 if (ifp->if_ioctl && (error = (*ifp->if_ioctl) 287 (ifp, SIOCSIFDSTADDR, (caddr_t)ia))) { 288 ia->ia_dstaddr = oldaddr; 289 return (error); 290 } 291 if (ia->ia_flags & IFA_ROUTE) { 292 ia->ia_ifa.ifa_dstaddr = (struct sockaddr *)&oldaddr; 293 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST); 294 ia->ia_ifa.ifa_dstaddr = 295 (struct sockaddr *)&ia->ia_dstaddr; 296 rtinit(&(ia->ia_ifa), (int)RTM_ADD, RTF_HOST|RTF_UP); 297 } 298 break; 299 300 case SIOCSIFBRDADDR: 301 if ((ifp->if_flags & IFF_BROADCAST) == 0) 302 return (EINVAL); 303 ia->ia_broadaddr = *(struct sockaddr_in *)&ifr->ifr_broadaddr; 304 break; 305 306 case SIOCSIFADDR: 307 return (in_ifinit(ifp, ia, 308 (struct sockaddr_in *) &ifr->ifr_addr, 1)); 309 310 case SIOCSIFNETMASK: 311 i = ifra->ifra_addr.sin_addr.s_addr; 312 ia->ia_subnetmask = ntohl(ia->ia_sockmask.sin_addr.s_addr = i); 313 break; 314 315 case SIOCAIFADDR: 316 maskIsNew = 0; 317 hostIsNew = 1; 318 error = 0; 319 if (ia->ia_addr.sin_family == AF_INET) { 320 if (ifra->ifra_addr.sin_len == 0) { 321 ifra->ifra_addr = ia->ia_addr; 322 hostIsNew = 0; 323 } else if (ifra->ifra_addr.sin_addr.s_addr == 324 ia->ia_addr.sin_addr.s_addr) 325 hostIsNew = 0; 326 } 327 if (ifra->ifra_mask.sin_len) { 328 in_ifscrub(ifp, ia); 329 ia->ia_sockmask = ifra->ifra_mask; 330 ia->ia_subnetmask = 331 ntohl(ia->ia_sockmask.sin_addr.s_addr); 332 maskIsNew = 1; 333 } 334 if ((ifp->if_flags & IFF_POINTOPOINT) && 335 (ifra->ifra_dstaddr.sin_family == AF_INET)) { 336 in_ifscrub(ifp, ia); 337 ia->ia_dstaddr = ifra->ifra_dstaddr; 338 maskIsNew = 1; /* We lie; but the effect's the same */ 339 } 340 if (ifra->ifra_addr.sin_family == AF_INET && 341 (hostIsNew || maskIsNew)) 342 error = in_ifinit(ifp, ia, &ifra->ifra_addr, 0); 343 if ((ifp->if_flags & IFF_BROADCAST) && 344 (ifra->ifra_broadaddr.sin_family == AF_INET)) 345 ia->ia_broadaddr = ifra->ifra_broadaddr; 346 return (error); 347 348 case SIOCDIFADDR: 349 in_ifscrub(ifp, ia); 350 if ((ifa = ifp->if_addrlist) == (struct ifaddr *)ia) 351 ifp->if_addrlist = ifa->ifa_next; 352 else { 353 while (ifa->ifa_next && 354 (ifa->ifa_next != (struct ifaddr *)ia)) 355 ifa = ifa->ifa_next; 356 if (ifa->ifa_next) 357 ifa->ifa_next = ((struct ifaddr *)ia)->ifa_next; 358 else 359 printf("Couldn't unlink inifaddr from ifp\n"); 360 } 361 oia = ia; 362 if (oia == (ia = in_ifaddr)) 363 in_ifaddr = ia->ia_next; 364 else { 365 while (ia->ia_next && (ia->ia_next != oia)) 366 ia = ia->ia_next; 367 if (ia->ia_next) 368 ia->ia_next = oia->ia_next; 369 else 370 printf("Didn't unlink inifadr from list\n"); 371 } 372 IFAFREE((&oia->ia_ifa)); 373 break; 374 375 default: 376 if (ifp == 0 || ifp->if_ioctl == 0) 377 return (EOPNOTSUPP); 378 return ((*ifp->if_ioctl)(ifp, cmd, data)); 379 } 380 return (0); 381 } 382 383 /* 384 * Delete any existing route for an interface. 385 */ 386 void 387 in_ifscrub(ifp, ia) 388 register struct ifnet *ifp; 389 register struct in_ifaddr *ia; 390 { 391 392 if ((ia->ia_flags & IFA_ROUTE) == 0) 393 return; 394 if (ifp->if_flags & (IFF_LOOPBACK|IFF_POINTOPOINT)) 395 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST); 396 else 397 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, 0); 398 ia->ia_flags &= ~IFA_ROUTE; 399 } 400 401 /* 402 * Initialize an interface's internet address 403 * and routing table entry. 404 */ 405 int 406 in_ifinit(ifp, ia, sin, scrub) 407 register struct ifnet *ifp; 408 register struct in_ifaddr *ia; 409 struct sockaddr_in *sin; 410 int scrub; 411 { 412 register u_long i = ntohl(sin->sin_addr.s_addr); 413 struct sockaddr_in oldaddr; 414 int s = splimp(), flags = RTF_UP, error, ether_output(); 415 416 oldaddr = ia->ia_addr; 417 ia->ia_addr = *sin; 418 /* 419 * Give the interface a chance to initialize 420 * if this is its first address, 421 * and to validate the address if necessary. 422 */ 423 if (ifp->if_ioctl && 424 (error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia))) { 425 splx(s); 426 ia->ia_addr = oldaddr; 427 return (error); 428 } 429 #if NETHER > 0 430 if (ifp->if_output == ether_output) { /* XXX: Another Kludge */ 431 ia->ia_ifa.ifa_rtrequest = arp_rtrequest; 432 ia->ia_ifa.ifa_flags |= RTF_CLONING; 433 } 434 #endif 435 splx(s); 436 if (scrub) { 437 ia->ia_ifa.ifa_addr = (struct sockaddr *)&oldaddr; 438 in_ifscrub(ifp, ia); 439 ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr; 440 } 441 if (IN_CLASSA(i)) 442 ia->ia_netmask = IN_CLASSA_NET; 443 else if (IN_CLASSB(i)) 444 ia->ia_netmask = IN_CLASSB_NET; 445 else 446 ia->ia_netmask = IN_CLASSC_NET; 447 /* 448 * The subnet mask usually includes at least the standard network part, 449 * but may may be smaller in the case of supernetting. 450 * If it is set, we believe it. 451 */ 452 if (ia->ia_subnetmask == 0) { 453 ia->ia_subnetmask = ia->ia_netmask; 454 ia->ia_sockmask.sin_addr.s_addr = htonl(ia->ia_subnetmask); 455 } else 456 ia->ia_netmask &= ia->ia_subnetmask; 457 ia->ia_net = i & ia->ia_netmask; 458 ia->ia_subnet = i & ia->ia_subnetmask; 459 in_socktrim(&ia->ia_sockmask); 460 /* 461 * Add route for the network. 462 */ 463 ia->ia_ifa.ifa_metric = ifp->if_metric; 464 if (ifp->if_flags & IFF_BROADCAST) { 465 ia->ia_broadaddr.sin_addr.s_addr = 466 htonl(ia->ia_subnet | ~ia->ia_subnetmask); 467 ia->ia_netbroadcast.s_addr = 468 htonl(ia->ia_net | ~ ia->ia_netmask); 469 } else if (ifp->if_flags & IFF_LOOPBACK) { 470 ia->ia_ifa.ifa_dstaddr = ia->ia_ifa.ifa_addr; 471 flags |= RTF_HOST; 472 } else if (ifp->if_flags & IFF_POINTOPOINT) { 473 if (ia->ia_dstaddr.sin_family != AF_INET) 474 return (0); 475 flags |= RTF_HOST; 476 } 477 if ((error = rtinit(&(ia->ia_ifa), (int)RTM_ADD, flags)) == 0) 478 ia->ia_flags |= IFA_ROUTE; 479 /* 480 * If the interface supports multicast, join the "all hosts" 481 * multicast group on that interface. 482 */ 483 if (ifp->if_flags & IFF_MULTICAST) { 484 struct in_addr addr; 485 486 addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP); 487 in_addmulti(&addr, ifp); 488 } 489 return (error); 490 } 491 492 493 /* 494 * Return 1 if the address might be a local broadcast address. 495 */ 496 int 497 in_broadcast(in, ifp) 498 struct in_addr in; 499 struct ifnet *ifp; 500 { 501 register struct ifaddr *ifa; 502 u_long t; 503 504 if (in.s_addr == INADDR_BROADCAST || 505 in.s_addr == INADDR_ANY) 506 return 1; 507 if ((ifp->if_flags & IFF_BROADCAST) == 0) 508 return 0; 509 t = ntohl(in.s_addr); 510 /* 511 * Look through the list of addresses for a match 512 * with a broadcast address. 513 */ 514 #define ia ((struct in_ifaddr *)ifa) 515 for (ifa = ifp->if_addrlist; ifa; ifa = ifa->ifa_next) 516 if (ifa->ifa_addr->sa_family == AF_INET && 517 (in.s_addr == ia->ia_broadaddr.sin_addr.s_addr || 518 in.s_addr == ia->ia_netbroadcast.s_addr || 519 /* 520 * Check for old-style (host 0) broadcast. 521 */ 522 t == ia->ia_subnet || t == ia->ia_net)) 523 return 1; 524 return (0); 525 #undef ia 526 } 527 528 /* 529 * Add an address to the list of IP multicast addresses for a given interface. 530 */ 531 struct in_multi * 532 in_addmulti(ap, ifp) 533 register struct in_addr *ap; 534 register struct ifnet *ifp; 535 { 536 register struct in_multi *inm; 537 struct ifreq ifr; 538 struct in_ifaddr *ia; 539 int s = splnet(); 540 541 /* 542 * See if address already in list. 543 */ 544 IN_LOOKUP_MULTI(*ap, ifp, inm); 545 if (inm != NULL) { 546 /* 547 * Found it; just increment the reference count. 548 */ 549 ++inm->inm_refcount; 550 } 551 else { 552 /* 553 * New address; allocate a new multicast record 554 * and link it into the interface's multicast list. 555 */ 556 inm = (struct in_multi *)malloc(sizeof(*inm), 557 M_IPMADDR, M_NOWAIT); 558 if (inm == NULL) { 559 splx(s); 560 return (NULL); 561 } 562 inm->inm_addr = *ap; 563 inm->inm_ifp = ifp; 564 inm->inm_refcount = 1; 565 IFP_TO_IA(ifp, ia); 566 if (ia == NULL) { 567 free(inm, M_IPMADDR); 568 splx(s); 569 return (NULL); 570 } 571 inm->inm_ia = ia; 572 inm->inm_next = ia->ia_multiaddrs; 573 ia->ia_multiaddrs = inm; 574 /* 575 * Ask the network driver to update its multicast reception 576 * filter appropriately for the new address. 577 */ 578 ((struct sockaddr_in *)&ifr.ifr_addr)->sin_family = AF_INET; 579 ((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr = *ap; 580 if ((ifp->if_ioctl == NULL) || 581 (*ifp->if_ioctl)(ifp, SIOCADDMULTI,(caddr_t)&ifr) != 0) { 582 ia->ia_multiaddrs = inm->inm_next; 583 free(inm, M_IPMADDR); 584 splx(s); 585 return (NULL); 586 } 587 /* 588 * Let IGMP know that we have joined a new IP multicast group. 589 */ 590 igmp_joingroup(inm); 591 } 592 splx(s); 593 return (inm); 594 } 595 596 /* 597 * Delete a multicast address record. 598 */ 599 int 600 in_delmulti(inm) 601 register struct in_multi *inm; 602 { 603 register struct in_multi **p; 604 struct ifreq ifr; 605 int s = splnet(); 606 607 if (--inm->inm_refcount == 0) { 608 /* 609 * No remaining claims to this record; let IGMP know that 610 * we are leaving the multicast group. 611 */ 612 igmp_leavegroup(inm); 613 /* 614 * Unlink from list. 615 */ 616 for (p = &inm->inm_ia->ia_multiaddrs; 617 *p != inm; 618 p = &(*p)->inm_next) 619 continue; 620 *p = (*p)->inm_next; 621 /* 622 * Notify the network driver to update its multicast reception 623 * filter. 624 */ 625 ((struct sockaddr_in *)&(ifr.ifr_addr))->sin_family = AF_INET; 626 ((struct sockaddr_in *)&(ifr.ifr_addr))->sin_addr = 627 inm->inm_addr; 628 (*inm->inm_ifp->if_ioctl)(inm->inm_ifp, SIOCDELMULTI, 629 (caddr_t)&ifr); 630 free(inm, M_IPMADDR); 631 } 632 splx(s); 633 } 634 #endif 635
Indexes created Sun Sep 21 20:09:37 GMT 2025