in.c revision 1.22
1 /* $NetBSD: in.c,v 1.22 1995/06/04 05:06:54 mycroft 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 #include <netinet/ip_mroute.h> 53 54 #include "ether.h" 55 56 #ifdef INET 57 58 #ifndef SUBNETSARELOCAL 59 #define SUBNETSARELOCAL 1 60 #endif 61 int subnetsarelocal = SUBNETSARELOCAL; 62 /* 63 * Return 1 if an internet address is for a ``local'' host 64 * (one to which we have a connection). If subnetsarelocal 65 * is true, this includes other subnets of the local net. 66 * Otherwise, it includes only the directly-connected (sub)nets. 67 */ 68 int 69 in_localaddr(in) 70 struct in_addr in; 71 { 72 register struct in_ifaddr *ia; 73 74 if (subnetsarelocal) { 75 for (ia = in_ifaddr; ia; ia = ia->ia_next) 76 if ((in.s_addr & ia->ia_netmask) == ia->ia_net) 77 return (1); 78 } else { 79 for (ia = in_ifaddr; ia; ia = ia->ia_next) 80 if ((in.s_addr & ia->ia_subnetmask) == ia->ia_subnet) 81 return (1); 82 } 83 return (0); 84 } 85 86 /* 87 * Determine whether an IP address is in a reserved set of addresses 88 * that may not be forwarded, or whether datagrams to that destination 89 * may be forwarded. 90 */ 91 int 92 in_canforward(in) 93 struct in_addr in; 94 { 95 register u_int32_t net; 96 97 if (IN_EXPERIMENTAL(in.s_addr) || IN_MULTICAST(in.s_addr)) 98 return (0); 99 if (IN_CLASSA(in.s_addr)) { 100 net = in.s_addr & IN_CLASSA_NET; 101 if (net == 0 || net == htonl(IN_LOOPBACKNET << IN_CLASSA_NSHIFT)) 102 return (0); 103 } 104 return (1); 105 } 106 107 /* 108 * Trim a mask in a sockaddr 109 */ 110 void 111 in_socktrim(ap) 112 struct sockaddr_in *ap; 113 { 114 register char *cplim = (char *) &ap->sin_addr; 115 register char *cp = (char *) (&ap->sin_addr + 1); 116 117 ap->sin_len = 0; 118 while (--cp >= cplim) 119 if (*cp) { 120 (ap)->sin_len = cp - (char *) (ap) + 1; 121 break; 122 } 123 } 124 125 int in_interfaces; /* number of external internet interfaces */ 126 127 /* 128 * Generic internet control operations (ioctl's). 129 * Ifp is 0 if not an interface-specific ioctl. 130 */ 131 /* ARGSUSED */ 132 int 133 in_control(so, cmd, data, ifp) 134 struct socket *so; 135 u_long cmd; 136 caddr_t data; 137 register struct ifnet *ifp; 138 { 139 register struct ifreq *ifr = (struct ifreq *)data; 140 register struct in_ifaddr *ia = 0; 141 register struct ifaddr *ifa; 142 struct in_ifaddr *oia; 143 struct in_aliasreq *ifra = (struct in_aliasreq *)data; 144 struct sockaddr_in oldaddr; 145 int error, hostIsNew, maskIsNew; 146 147 /* 148 * Find address for this interface, if it exists. 149 */ 150 if (ifp) 151 for (ia = in_ifaddr; ia; ia = ia->ia_next) 152 if (ia->ia_ifp == ifp) 153 break; 154 155 switch (cmd) { 156 157 case SIOCAIFADDR: 158 case SIOCDIFADDR: 159 if (ifra->ifra_addr.sin_family == AF_INET) 160 for (oia = ia; ia; ia = ia->ia_next) { 161 if (ia->ia_ifp == ifp && 162 ia->ia_addr.sin_addr.s_addr == 163 ifra->ifra_addr.sin_addr.s_addr) 164 break; 165 } 166 if (cmd == SIOCDIFADDR && ia == 0) 167 return (EADDRNOTAVAIL); 168 /* FALLTHROUGH */ 169 case SIOCSIFADDR: 170 case SIOCSIFNETMASK: 171 case SIOCSIFDSTADDR: 172 if ((so->so_state & SS_PRIV) == 0) 173 return (EPERM); 174 175 if (ifp == 0) 176 panic("in_control"); 177 if (ia == (struct in_ifaddr *)0) { 178 oia = (struct in_ifaddr *) 179 malloc(sizeof *oia, M_IFADDR, M_WAITOK); 180 if (oia == (struct in_ifaddr *)0) 181 return (ENOBUFS); 182 bzero((caddr_t)oia, sizeof *oia); 183 if (ia = in_ifaddr) { 184 for ( ; ia->ia_next; ia = ia->ia_next) 185 continue; 186 ia->ia_next = oia; 187 } else 188 in_ifaddr = oia; 189 ia = oia; 190 if (ifa = ifp->if_addrlist) { 191 for ( ; ifa->ifa_next; ifa = ifa->ifa_next) 192 continue; 193 ifa->ifa_next = (struct ifaddr *) ia; 194 } else 195 ifp->if_addrlist = (struct ifaddr *) ia; 196 ia->ia_ifa.ifa_addr = sintosa(&ia->ia_addr); 197 ia->ia_ifa.ifa_dstaddr = sintosa(&ia->ia_dstaddr); 198 ia->ia_ifa.ifa_netmask = sintosa(&ia->ia_sockmask); 199 ia->ia_sockmask.sin_len = 8; 200 if (ifp->if_flags & IFF_BROADCAST) { 201 ia->ia_broadaddr.sin_len = sizeof(ia->ia_addr); 202 ia->ia_broadaddr.sin_family = AF_INET; 203 } 204 ia->ia_ifp = ifp; 205 if ((ifp->if_flags & IFF_LOOPBACK) == 0) 206 in_interfaces++; 207 } 208 break; 209 210 case SIOCSIFBRDADDR: 211 if ((so->so_state & SS_PRIV) == 0) 212 return (EPERM); 213 /* FALLTHROUGH */ 214 215 case SIOCGIFADDR: 216 case SIOCGIFNETMASK: 217 case SIOCGIFDSTADDR: 218 case SIOCGIFBRDADDR: 219 if (ia == (struct in_ifaddr *)0) 220 return (EADDRNOTAVAIL); 221 break; 222 } 223 switch (cmd) { 224 225 case SIOCGIFADDR: 226 *satosin(&ifr->ifr_addr) = ia->ia_addr; 227 break; 228 229 case SIOCGIFBRDADDR: 230 if ((ifp->if_flags & IFF_BROADCAST) == 0) 231 return (EINVAL); 232 *satosin(&ifr->ifr_dstaddr) = ia->ia_broadaddr; 233 break; 234 235 case SIOCGIFDSTADDR: 236 if ((ifp->if_flags & IFF_POINTOPOINT) == 0) 237 return (EINVAL); 238 *satosin(&ifr->ifr_dstaddr) = ia->ia_dstaddr; 239 break; 240 241 case SIOCGIFNETMASK: 242 *satosin(&ifr->ifr_addr) = ia->ia_sockmask; 243 break; 244 245 case SIOCSIFDSTADDR: 246 if ((ifp->if_flags & IFF_POINTOPOINT) == 0) 247 return (EINVAL); 248 oldaddr = ia->ia_dstaddr; 249 ia->ia_dstaddr = *satosin(&ifr->ifr_dstaddr); 250 if (ifp->if_ioctl && (error = (*ifp->if_ioctl) 251 (ifp, SIOCSIFDSTADDR, (caddr_t)ia))) { 252 ia->ia_dstaddr = oldaddr; 253 return (error); 254 } 255 if (ia->ia_flags & IFA_ROUTE) { 256 ia->ia_ifa.ifa_dstaddr = sintosa(&oldaddr); 257 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST); 258 ia->ia_ifa.ifa_dstaddr = sintosa(&ia->ia_dstaddr); 259 rtinit(&(ia->ia_ifa), (int)RTM_ADD, RTF_HOST|RTF_UP); 260 } 261 break; 262 263 case SIOCSIFBRDADDR: 264 if ((ifp->if_flags & IFF_BROADCAST) == 0) 265 return (EINVAL); 266 ia->ia_broadaddr = *satosin(&ifr->ifr_broadaddr); 267 break; 268 269 case SIOCSIFADDR: 270 return (in_ifinit(ifp, ia, satosin(&ifr->ifr_addr), 1)); 271 272 case SIOCSIFNETMASK: 273 ia->ia_subnetmask = ia->ia_sockmask.sin_addr.s_addr = 274 ifra->ifra_addr.sin_addr.s_addr; 275 break; 276 277 case SIOCAIFADDR: 278 maskIsNew = 0; 279 hostIsNew = 1; 280 error = 0; 281 if (ia->ia_addr.sin_family == AF_INET) { 282 if (ifra->ifra_addr.sin_len == 0) { 283 ifra->ifra_addr = ia->ia_addr; 284 hostIsNew = 0; 285 } else if (ifra->ifra_addr.sin_addr.s_addr == 286 ia->ia_addr.sin_addr.s_addr) 287 hostIsNew = 0; 288 } 289 if (ifra->ifra_mask.sin_len) { 290 in_ifscrub(ifp, ia); 291 ia->ia_sockmask = ifra->ifra_mask; 292 ia->ia_subnetmask = ia->ia_sockmask.sin_addr.s_addr; 293 maskIsNew = 1; 294 } 295 if ((ifp->if_flags & IFF_POINTOPOINT) && 296 (ifra->ifra_dstaddr.sin_family == AF_INET)) { 297 in_ifscrub(ifp, ia); 298 ia->ia_dstaddr = ifra->ifra_dstaddr; 299 maskIsNew = 1; /* We lie; but the effect's the same */ 300 } 301 if (ifra->ifra_addr.sin_family == AF_INET && 302 (hostIsNew || maskIsNew)) 303 error = in_ifinit(ifp, ia, &ifra->ifra_addr, 0); 304 if ((ifp->if_flags & IFF_BROADCAST) && 305 (ifra->ifra_broadaddr.sin_family == AF_INET)) 306 ia->ia_broadaddr = ifra->ifra_broadaddr; 307 return (error); 308 309 case SIOCDIFADDR: 310 in_ifscrub(ifp, ia); 311 if ((ifa = ifp->if_addrlist) == (struct ifaddr *)ia) 312 ifp->if_addrlist = ifa->ifa_next; 313 else { 314 while (ifa->ifa_next && 315 (ifa->ifa_next != (struct ifaddr *)ia)) 316 ifa = ifa->ifa_next; 317 if (ifa->ifa_next) 318 ifa->ifa_next = ((struct ifaddr *)ia)->ifa_next; 319 else 320 printf("Couldn't unlink inifaddr from ifp\n"); 321 } 322 oia = ia; 323 if (oia == (ia = in_ifaddr)) 324 in_ifaddr = ia->ia_next; 325 else { 326 while (ia->ia_next && (ia->ia_next != oia)) 327 ia = ia->ia_next; 328 if (ia->ia_next) 329 ia->ia_next = oia->ia_next; 330 else 331 printf("Didn't unlink inifadr from list\n"); 332 } 333 IFAFREE((&oia->ia_ifa)); 334 break; 335 336 #ifdef MROUTING 337 case SIOCGETVIFCNT: 338 case SIOCGETSGCNT: 339 return (mrt_ioctl(cmd, data)); 340 #endif /* MROUTING */ 341 342 default: 343 if (ifp == 0 || ifp->if_ioctl == 0) 344 return (EOPNOTSUPP); 345 return ((*ifp->if_ioctl)(ifp, cmd, data)); 346 } 347 return (0); 348 } 349 350 /* 351 * Delete any existing route for an interface. 352 */ 353 void 354 in_ifscrub(ifp, ia) 355 register struct ifnet *ifp; 356 register struct in_ifaddr *ia; 357 { 358 359 if ((ia->ia_flags & IFA_ROUTE) == 0) 360 return; 361 if (ifp->if_flags & (IFF_LOOPBACK|IFF_POINTOPOINT)) 362 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST); 363 else 364 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, 0); 365 ia->ia_flags &= ~IFA_ROUTE; 366 } 367 368 /* 369 * Initialize an interface's internet address 370 * and routing table entry. 371 */ 372 int 373 in_ifinit(ifp, ia, sin, scrub) 374 register struct ifnet *ifp; 375 register struct in_ifaddr *ia; 376 struct sockaddr_in *sin; 377 int scrub; 378 { 379 register u_int32_t i = sin->sin_addr.s_addr; 380 struct sockaddr_in oldaddr; 381 int s = splimp(), flags = RTF_UP, error, ether_output(); 382 383 oldaddr = ia->ia_addr; 384 ia->ia_addr = *sin; 385 /* 386 * Give the interface a chance to initialize 387 * if this is its first address, 388 * and to validate the address if necessary. 389 */ 390 if (ifp->if_ioctl && 391 (error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia))) { 392 splx(s); 393 ia->ia_addr = oldaddr; 394 return (error); 395 } 396 splx(s); 397 if (scrub) { 398 ia->ia_ifa.ifa_addr = sintosa(&oldaddr); 399 in_ifscrub(ifp, ia); 400 ia->ia_ifa.ifa_addr = sintosa(&ia->ia_addr); 401 } 402 if (IN_CLASSA(i)) 403 ia->ia_netmask = IN_CLASSA_NET; 404 else if (IN_CLASSB(i)) 405 ia->ia_netmask = IN_CLASSB_NET; 406 else 407 ia->ia_netmask = IN_CLASSC_NET; 408 /* 409 * The subnet mask usually includes at least the standard network part, 410 * but may may be smaller in the case of supernetting. 411 * If it is set, we believe it. 412 */ 413 if (ia->ia_subnetmask == 0) { 414 ia->ia_subnetmask = ia->ia_netmask; 415 ia->ia_sockmask.sin_addr.s_addr = ia->ia_subnetmask; 416 } else 417 ia->ia_netmask &= ia->ia_subnetmask; 418 ia->ia_net = i & ia->ia_netmask; 419 ia->ia_subnet = i & ia->ia_subnetmask; 420 in_socktrim(&ia->ia_sockmask); 421 /* 422 * Add route for the network. 423 */ 424 ia->ia_ifa.ifa_metric = ifp->if_metric; 425 if (ifp->if_flags & IFF_BROADCAST) { 426 ia->ia_broadaddr.sin_addr.s_addr = 427 ia->ia_subnet | ~ia->ia_subnetmask; 428 ia->ia_netbroadcast.s_addr = 429 ia->ia_net | ~ia->ia_netmask; 430 } else if (ifp->if_flags & IFF_LOOPBACK) { 431 ia->ia_ifa.ifa_dstaddr = ia->ia_ifa.ifa_addr; 432 flags |= RTF_HOST; 433 } else if (ifp->if_flags & IFF_POINTOPOINT) { 434 if (ia->ia_dstaddr.sin_family != AF_INET) 435 return (0); 436 flags |= RTF_HOST; 437 } 438 if ((error = rtinit(&(ia->ia_ifa), (int)RTM_ADD, flags)) == 0) 439 ia->ia_flags |= IFA_ROUTE; 440 /* 441 * If the interface supports multicast, join the "all hosts" 442 * multicast group on that interface. 443 */ 444 if (ifp->if_flags & IFF_MULTICAST) { 445 struct in_addr addr; 446 447 addr.s_addr = INADDR_ALLHOSTS_GROUP; 448 in_addmulti(&addr, ifp); 449 } 450 return (error); 451 } 452 453 454 /* 455 * Return 1 if the address might be a local broadcast address. 456 */ 457 int 458 in_broadcast(in, ifp) 459 struct in_addr in; 460 struct ifnet *ifp; 461 { 462 register struct ifaddr *ifa; 463 464 if (in.s_addr == INADDR_BROADCAST || 465 in.s_addr == INADDR_ANY) 466 return 1; 467 if ((ifp->if_flags & IFF_BROADCAST) == 0) 468 return 0; 469 /* 470 * Look through the list of addresses for a match 471 * with a broadcast address. 472 */ 473 #define ia (ifatoia(ifa)) 474 for (ifa = ifp->if_addrlist; ifa; ifa = ifa->ifa_next) 475 if (ifa->ifa_addr->sa_family == AF_INET && 476 (in.s_addr == ia->ia_broadaddr.sin_addr.s_addr || 477 in.s_addr == ia->ia_netbroadcast.s_addr || 478 /* 479 * Check for old-style (host 0) broadcast. 480 */ 481 in.s_addr == ia->ia_subnet || 482 in.s_addr == ia->ia_net)) 483 return 1; 484 return (0); 485 #undef ia 486 } 487 488 /* 489 * Add an address to the list of IP multicast addresses for a given interface. 490 */ 491 struct in_multi * 492 in_addmulti(ap, ifp) 493 register struct in_addr *ap; 494 register struct ifnet *ifp; 495 { 496 register struct in_multi *inm; 497 struct ifreq ifr; 498 struct in_ifaddr *ia; 499 int s = splnet(); 500 501 /* 502 * See if address already in list. 503 */ 504 IN_LOOKUP_MULTI(*ap, ifp, inm); 505 if (inm != NULL) { 506 /* 507 * Found it; just increment the reference count. 508 */ 509 ++inm->inm_refcount; 510 } 511 else { 512 /* 513 * New address; allocate a new multicast record 514 * and link it into the interface's multicast list. 515 */ 516 inm = (struct in_multi *)malloc(sizeof(*inm), 517 M_IPMADDR, M_NOWAIT); 518 if (inm == NULL) { 519 splx(s); 520 return (NULL); 521 } 522 inm->inm_addr = *ap; 523 inm->inm_ifp = ifp; 524 inm->inm_refcount = 1; 525 IFP_TO_IA(ifp, ia); 526 if (ia == NULL) { 527 free(inm, M_IPMADDR); 528 splx(s); 529 return (NULL); 530 } 531 inm->inm_ia = ia; 532 inm->inm_next = ia->ia_multiaddrs; 533 ia->ia_multiaddrs = inm; 534 /* 535 * Ask the network driver to update its multicast reception 536 * filter appropriately for the new address. 537 */ 538 satosin(&ifr.ifr_addr)->sin_family = AF_INET; 539 satosin(&ifr.ifr_addr)->sin_addr = *ap; 540 if ((ifp->if_ioctl == NULL) || 541 (*ifp->if_ioctl)(ifp, SIOCADDMULTI,(caddr_t)&ifr) != 0) { 542 ia->ia_multiaddrs = inm->inm_next; 543 free(inm, M_IPMADDR); 544 splx(s); 545 return (NULL); 546 } 547 /* 548 * Let IGMP know that we have joined a new IP multicast group. 549 */ 550 igmp_joingroup(inm); 551 } 552 splx(s); 553 return (inm); 554 } 555 556 /* 557 * Delete a multicast address record. 558 */ 559 int 560 in_delmulti(inm) 561 register struct in_multi *inm; 562 { 563 register struct in_multi **p; 564 struct ifreq ifr; 565 int s = splnet(); 566 567 if (--inm->inm_refcount == 0) { 568 /* 569 * No remaining claims to this record; let IGMP know that 570 * we are leaving the multicast group. 571 */ 572 igmp_leavegroup(inm); 573 /* 574 * Unlink from list. 575 */ 576 for (p = &inm->inm_ia->ia_multiaddrs; 577 *p != inm; 578 p = &(*p)->inm_next) 579 continue; 580 *p = (*p)->inm_next; 581 /* 582 * Notify the network driver to update its multicast reception 583 * filter. 584 */ 585 satosin(&ifr.ifr_addr)->sin_family = AF_INET; 586 satosin(&ifr.ifr_addr)->sin_addr = inm->inm_addr; 587 (*inm->inm_ifp->if_ioctl)(inm->inm_ifp, SIOCDELMULTI, 588 (caddr_t)&ifr); 589 free(inm, M_IPMADDR); 590 } 591 splx(s); 592 } 593 594 #endif 595
Indexes created Sun Sep 21 20:09:37 GMT 2025