in.c revision 1.12
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 * from: @(#)in.c 8.2 (Berkeley) 11/15/93 34 * $Id: in.c,v 1.12 1994/05/13 06:06:02 mycroft Exp $ 35 */ 36 37 #include <sys/param.h> 38 #include <sys/ioctl.h> 39 #include <sys/errno.h> 40 #include <sys/malloc.h> 41 #include <sys/socket.h> 42 #include <sys/socketvar.h> 43 44 #include <net/if.h> 45 #include <net/route.h> 46 47 #include <netinet/in_systm.h> 48 #include <netinet/in.h> 49 #include <netinet/in_var.h> 50 #include <netinet/if_ether.h> 51 52 #ifdef INET 53 /* 54 * Return the network number from an internet address. 55 */ 56 u_long 57 in_netof(in) 58 struct in_addr in; 59 { 60 register u_long i = ntohl(in.s_addr); 61 register u_long net; 62 register struct in_ifaddr *ia; 63 64 if (IN_CLASSA(i)) 65 net = i & IN_CLASSA_NET; 66 else if (IN_CLASSB(i)) 67 net = i & IN_CLASSB_NET; 68 else if (IN_CLASSC(i)) 69 net = i & IN_CLASSC_NET; 70 else if (IN_CLASSD(i)) 71 net = i & IN_CLASSD_NET; 72 else 73 return (0); 74 75 /* 76 * Check whether network is a subnet; 77 * if so, return subnet number. 78 */ 79 for (ia = in_ifaddr; ia; ia = ia->ia_next) 80 if (net == ia->ia_net) 81 return (i & ia->ia_subnetmask); 82 return (net); 83 } 84 85 #ifndef SUBNETSARELOCAL 86 #define SUBNETSARELOCAL 1 87 #endif 88 int subnetsarelocal = SUBNETSARELOCAL; 89 /* 90 * Return 1 if an internet address is for a ``local'' host 91 * (one to which we have a connection). If subnetsarelocal 92 * is true, this includes other subnets of the local net. 93 * Otherwise, it includes only the directly-connected (sub)nets. 94 */ 95 int 96 in_localaddr(in) 97 struct in_addr in; 98 { 99 register u_long i = ntohl(in.s_addr); 100 register struct in_ifaddr *ia; 101 102 if (subnetsarelocal) { 103 for (ia = in_ifaddr; ia; ia = ia->ia_next) 104 if ((i & ia->ia_netmask) == ia->ia_net) 105 return (1); 106 } else { 107 for (ia = in_ifaddr; ia; ia = ia->ia_next) 108 if ((i & ia->ia_subnetmask) == ia->ia_subnet) 109 return (1); 110 } 111 return (0); 112 } 113 114 /* 115 * Determine whether an IP address is in a reserved set of addresses 116 * that may not be forwarded, or whether datagrams to that destination 117 * may be forwarded. 118 */ 119 int 120 in_canforward(in) 121 struct in_addr in; 122 { 123 register u_long i = ntohl(in.s_addr); 124 register u_long net; 125 126 if (IN_EXPERIMENTAL(i) || IN_MULTICAST(i)) 127 return (0); 128 if (IN_CLASSA(i)) { 129 net = i & IN_CLASSA_NET; 130 if (net == 0 || net == (IN_LOOPBACKNET << IN_CLASSA_NSHIFT)) 131 return (0); 132 } 133 return (1); 134 } 135 136 /* 137 * Trim a mask in a sockaddr 138 */ 139 void 140 in_socktrim(ap) 141 struct sockaddr_in *ap; 142 { 143 register char *cplim = (char *) &ap->sin_addr; 144 register char *cp = (char *) (&ap->sin_addr + 1); 145 146 ap->sin_len = 0; 147 while (--cp > cplim) 148 if (*cp) { 149 (ap)->sin_len = cp - (char *) (ap) + 1; 150 break; 151 } 152 } 153 154 int in_interfaces; /* number of external internet interfaces */ 155 extern struct ifnet loif; 156 157 /* 158 * Generic internet control operations (ioctl's). 159 * Ifp is 0 if not an interface-specific ioctl. 160 */ 161 /* ARGSUSED */ 162 int 163 in_control(so, cmd, data, ifp) 164 struct socket *so; 165 int cmd; 166 caddr_t data; 167 register struct ifnet *ifp; 168 { 169 register struct ifreq *ifr = (struct ifreq *)data; 170 register struct in_ifaddr *ia = 0; 171 register struct ifaddr *ifa; 172 struct in_ifaddr *oia; 173 struct in_aliasreq *ifra = (struct in_aliasreq *)data; 174 struct sockaddr_in oldaddr; 175 int error, hostIsNew, maskIsNew; 176 u_long i; 177 178 /* 179 * Find address for this interface, if it exists. 180 */ 181 if (ifp) 182 for (ia = in_ifaddr; ia; ia = ia->ia_next) 183 if (ia->ia_ifp == ifp) 184 break; 185 186 switch (cmd) { 187 188 case SIOCAIFADDR: 189 case SIOCDIFADDR: 190 if (ifra->ifra_addr.sin_family == AF_INET) 191 for (oia = ia; ia; ia = ia->ia_next) { 192 if (ia->ia_ifp == ifp && 193 ia->ia_addr.sin_addr.s_addr == 194 ifra->ifra_addr.sin_addr.s_addr) 195 break; 196 } 197 if (cmd == SIOCDIFADDR && ia == 0) 198 return (EADDRNOTAVAIL); 199 /* FALLTHROUGH */ 200 case SIOCSIFADDR: 201 case SIOCSIFNETMASK: 202 case SIOCSIFDSTADDR: 203 if ((so->so_state & SS_PRIV) == 0) 204 return (EPERM); 205 206 if (ifp == 0) 207 panic("in_control"); 208 if (ia == (struct in_ifaddr *)0) { 209 oia = (struct in_ifaddr *) 210 malloc(sizeof *oia, M_IFADDR, M_WAITOK); 211 if (oia == (struct in_ifaddr *)NULL) 212 return (ENOBUFS); 213 bzero((caddr_t)oia, sizeof *oia); 214 if (ia = in_ifaddr) { 215 for ( ; ia->ia_next; ia = ia->ia_next) 216 continue; 217 ia->ia_next = oia; 218 } else 219 in_ifaddr = oia; 220 ia = oia; 221 if (ifa = ifp->if_addrlist) { 222 for ( ; ifa->ifa_next; ifa = ifa->ifa_next) 223 continue; 224 ifa->ifa_next = (struct ifaddr *) ia; 225 } else 226 ifp->if_addrlist = (struct ifaddr *) ia; 227 ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr; 228 ia->ia_ifa.ifa_dstaddr 229 = (struct sockaddr *)&ia->ia_dstaddr; 230 ia->ia_ifa.ifa_netmask 231 = (struct sockaddr *)&ia->ia_sockmask; 232 ia->ia_sockmask.sin_len = 8; 233 if (ifp->if_flags & IFF_BROADCAST) { 234 ia->ia_broadaddr.sin_len = sizeof(ia->ia_addr); 235 ia->ia_broadaddr.sin_family = AF_INET; 236 } 237 ia->ia_ifp = ifp; 238 if (ifp != &loif) 239 in_interfaces++; 240 } 241 break; 242 243 case SIOCSIFBRDADDR: 244 if ((so->so_state & SS_PRIV) == 0) 245 return (EPERM); 246 /* FALLTHROUGH */ 247 248 case SIOCGIFADDR: 249 case SIOCGIFNETMASK: 250 case SIOCGIFDSTADDR: 251 case SIOCGIFBRDADDR: 252 if (ia == (struct in_ifaddr *)0) 253 return (EADDRNOTAVAIL); 254 break; 255 } 256 switch (cmd) { 257 258 case SIOCGIFADDR: 259 *((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_addr; 260 break; 261 262 case SIOCGIFBRDADDR: 263 if ((ifp->if_flags & IFF_BROADCAST) == 0) 264 return (EINVAL); 265 *((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_broadaddr; 266 break; 267 268 case SIOCGIFDSTADDR: 269 if ((ifp->if_flags & IFF_POINTOPOINT) == 0) 270 return (EINVAL); 271 *((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_dstaddr; 272 break; 273 274 case SIOCGIFNETMASK: 275 *((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_sockmask; 276 break; 277 278 case SIOCSIFDSTADDR: 279 if ((ifp->if_flags & IFF_POINTOPOINT) == 0) 280 return (EINVAL); 281 oldaddr = ia->ia_dstaddr; 282 ia->ia_dstaddr = *(struct sockaddr_in *)&ifr->ifr_dstaddr; 283 if (ifp->if_ioctl && (error = (*ifp->if_ioctl) 284 (ifp, SIOCSIFDSTADDR, (caddr_t)ia))) { 285 ia->ia_dstaddr = oldaddr; 286 return (error); 287 } 288 if (ia->ia_flags & IFA_ROUTE) { 289 ia->ia_ifa.ifa_dstaddr = (struct sockaddr *)&oldaddr; 290 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST); 291 ia->ia_ifa.ifa_dstaddr = 292 (struct sockaddr *)&ia->ia_dstaddr; 293 rtinit(&(ia->ia_ifa), (int)RTM_ADD, RTF_HOST|RTF_UP); 294 } 295 break; 296 297 case SIOCSIFBRDADDR: 298 if ((ifp->if_flags & IFF_BROADCAST) == 0) 299 return (EINVAL); 300 ia->ia_broadaddr = *(struct sockaddr_in *)&ifr->ifr_broadaddr; 301 break; 302 303 case SIOCSIFADDR: 304 return (in_ifinit(ifp, ia, 305 (struct sockaddr_in *) &ifr->ifr_addr, 1)); 306 307 case SIOCSIFNETMASK: 308 i = ifra->ifra_addr.sin_addr.s_addr; 309 ia->ia_subnetmask = ntohl(ia->ia_sockmask.sin_addr.s_addr = i); 310 break; 311 312 case SIOCAIFADDR: 313 maskIsNew = 0; 314 hostIsNew = 1; 315 error = 0; 316 if (ia->ia_addr.sin_family == AF_INET) { 317 if (ifra->ifra_addr.sin_len == 0) { 318 ifra->ifra_addr = ia->ia_addr; 319 hostIsNew = 0; 320 } else if (ifra->ifra_addr.sin_addr.s_addr == 321 ia->ia_addr.sin_addr.s_addr) 322 hostIsNew = 0; 323 } 324 if (ifra->ifra_mask.sin_len) { 325 in_ifscrub(ifp, ia); 326 ia->ia_sockmask = ifra->ifra_mask; 327 ia->ia_subnetmask = 328 ntohl(ia->ia_sockmask.sin_addr.s_addr); 329 maskIsNew = 1; 330 } 331 if ((ifp->if_flags & IFF_POINTOPOINT) && 332 (ifra->ifra_dstaddr.sin_family == AF_INET)) { 333 in_ifscrub(ifp, ia); 334 ia->ia_dstaddr = ifra->ifra_dstaddr; 335 maskIsNew = 1; /* We lie; but the effect's the same */ 336 } 337 if (ifra->ifra_addr.sin_family == AF_INET && 338 (hostIsNew || maskIsNew)) 339 error = in_ifinit(ifp, ia, &ifra->ifra_addr, 0); 340 if ((ifp->if_flags & IFF_BROADCAST) && 341 (ifra->ifra_broadaddr.sin_family == AF_INET)) 342 ia->ia_broadaddr = ifra->ifra_broadaddr; 343 return (error); 344 345 case SIOCDIFADDR: 346 in_ifscrub(ifp, ia); 347 if ((ifa = ifp->if_addrlist) == (struct ifaddr *)ia) 348 ifp->if_addrlist = ifa->ifa_next; 349 else { 350 while (ifa->ifa_next && 351 (ifa->ifa_next != (struct ifaddr *)ia)) 352 ifa = ifa->ifa_next; 353 if (ifa->ifa_next) 354 ifa->ifa_next = ((struct ifaddr *)ia)->ifa_next; 355 else 356 printf("Couldn't unlink inifaddr from ifp\n"); 357 } 358 oia = ia; 359 if (oia == (ia = in_ifaddr)) 360 in_ifaddr = ia->ia_next; 361 else { 362 while (ia->ia_next && (ia->ia_next != oia)) 363 ia = ia->ia_next; 364 if (ia->ia_next) 365 ia->ia_next = oia->ia_next; 366 else 367 printf("Didn't unlink inifadr from list\n"); 368 } 369 IFAFREE((&oia->ia_ifa)); 370 break; 371 372 default: 373 if (ifp == 0 || ifp->if_ioctl == 0) 374 return (EOPNOTSUPP); 375 return ((*ifp->if_ioctl)(ifp, cmd, data)); 376 } 377 return (0); 378 } 379 380 /* 381 * Delete any existing route for an interface. 382 */ 383 void 384 in_ifscrub(ifp, ia) 385 register struct ifnet *ifp; 386 register struct in_ifaddr *ia; 387 { 388 389 if ((ia->ia_flags & IFA_ROUTE) == 0) 390 return; 391 if (ifp->if_flags & (IFF_LOOPBACK|IFF_POINTOPOINT)) 392 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST); 393 else 394 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, 0); 395 ia->ia_flags &= ~IFA_ROUTE; 396 } 397 398 /* 399 * Initialize an interface's internet address 400 * and routing table entry. 401 */ 402 int 403 in_ifinit(ifp, ia, sin, scrub) 404 register struct ifnet *ifp; 405 register struct in_ifaddr *ia; 406 struct sockaddr_in *sin; 407 int scrub; 408 { 409 register u_long i = ntohl(sin->sin_addr.s_addr); 410 struct sockaddr_in oldaddr; 411 int s = splimp(), flags = RTF_UP, error, ether_output(); 412 413 oldaddr = ia->ia_addr; 414 ia->ia_addr = *sin; 415 /* 416 * Give the interface a chance to initialize 417 * if this is its first address, 418 * and to validate the address if necessary. 419 */ 420 if (ifp->if_ioctl && 421 (error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia))) { 422 splx(s); 423 ia->ia_addr = oldaddr; 424 return (error); 425 } 426 if (ifp->if_output == ether_output) { /* XXX: Another Kludge */ 427 ia->ia_ifa.ifa_rtrequest = arp_rtrequest; 428 ia->ia_ifa.ifa_flags |= RTF_CLONING; 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 /* 524 * Add an address to the list of IP multicast addresses for a given interface. 525 */ 526 struct in_multi * 527 in_addmulti(ap, ifp) 528 register struct in_addr *ap; 529 register struct ifnet *ifp; 530 { 531 register struct in_multi *inm; 532 struct ifreq ifr; 533 struct in_ifaddr *ia; 534 int s = splnet(); 535 536 /* 537 * See if address already in list. 538 */ 539 IN_LOOKUP_MULTI(*ap, ifp, inm); 540 if (inm != NULL) { 541 /* 542 * Found it; just increment the reference count. 543 */ 544 ++inm->inm_refcount; 545 } 546 else { 547 /* 548 * New address; allocate a new multicast record 549 * and link it into the interface's multicast list. 550 */ 551 inm = (struct in_multi *)malloc(sizeof(*inm), 552 M_IPMADDR, M_NOWAIT); 553 if (inm == NULL) { 554 splx(s); 555 return (NULL); 556 } 557 inm->inm_addr = *ap; 558 inm->inm_ifp = ifp; 559 inm->inm_refcount = 1; 560 IFP_TO_IA(ifp, ia); 561 if (ia == NULL) { 562 free(inm, M_IPMADDR); 563 splx(s); 564 return (NULL); 565 } 566 inm->inm_ia = ia; 567 inm->inm_next = ia->ia_multiaddrs; 568 ia->ia_multiaddrs = inm; 569 /* 570 * Ask the network driver to update its multicast reception 571 * filter appropriately for the new address. 572 */ 573 ((struct sockaddr_in *)&ifr.ifr_addr)->sin_family = AF_INET; 574 ((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr = *ap; 575 if ((ifp->if_ioctl == NULL) || 576 (*ifp->if_ioctl)(ifp, SIOCADDMULTI,(caddr_t)&ifr) != 0) { 577 ia->ia_multiaddrs = inm->inm_next; 578 free(inm, M_IPMADDR); 579 splx(s); 580 return (NULL); 581 } 582 /* 583 * Let IGMP know that we have joined a new IP multicast group. 584 */ 585 igmp_joingroup(inm); 586 } 587 splx(s); 588 return (inm); 589 } 590 591 /* 592 * Delete a multicast address record. 593 */ 594 int 595 in_delmulti(inm) 596 register struct in_multi *inm; 597 { 598 register struct in_multi **p; 599 struct ifreq ifr; 600 int s = splnet(); 601 602 if (--inm->inm_refcount == 0) { 603 /* 604 * No remaining claims to this record; let IGMP know that 605 * we are leaving the multicast group. 606 */ 607 igmp_leavegroup(inm); 608 /* 609 * Unlink from list. 610 */ 611 for (p = &inm->inm_ia->ia_multiaddrs; 612 *p != inm; 613 p = &(*p)->inm_next) 614 continue; 615 *p = (*p)->inm_next; 616 /* 617 * Notify the network driver to update its multicast reception 618 * filter. 619 */ 620 ((struct sockaddr_in *)&(ifr.ifr_addr))->sin_family = AF_INET; 621 ((struct sockaddr_in *)&(ifr.ifr_addr))->sin_addr = 622 inm->inm_addr; 623 (*inm->inm_ifp->if_ioctl)(inm->inm_ifp, SIOCDELMULTI, 624 (caddr_t)&ifr); 625 free(inm, M_IPMADDR); 626 } 627 splx(s); 628 } 629 #endif 630
Indexes created Mon Sep 22 13:09:51 GMT 2025