1 /* 2 * Copyright (c) 1982, 1986, 1991 Regents of the University of California. 3 * All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 * 7 * @(#)in.c 7.31 (Berkeley) 04/07/93 8 */ 9 10 #include <sys/param.h> 11 #include <sys/ioctl.h> 12 #include <sys/errno.h> 13 #include <sys/malloc.h> 14 #include <sys/socket.h> 15 #include <sys/socketvar.h> 16 17 #include <net/if.h> 18 #include <net/route.h> 19 #include <net/af.h> 20 21 #include <netinet/in_systm.h> 22 #include <netinet/in.h> 23 #include <netinet/in_var.h> 24 25 #ifdef INET 26 /* 27 * Formulate an Internet address from network + host. 28 */ 29 struct in_addr 30 in_makeaddr(net, host) 31 u_long net, host; 32 { 33 register struct in_ifaddr *ia; 34 register u_long mask; 35 u_long addr; 36 37 if (IN_CLASSA(net)) 38 mask = IN_CLASSA_HOST; 39 else if (IN_CLASSB(net)) 40 mask = IN_CLASSB_HOST; 41 else 42 mask = IN_CLASSC_HOST; 43 for (ia = in_ifaddr; ia; ia = ia->ia_next) 44 if ((ia->ia_netmask & net) == ia->ia_net) { 45 mask = ~ia->ia_subnetmask; 46 break; 47 } 48 addr = htonl(net | (host & mask)); 49 return (*(struct in_addr *)&addr); 50 } 51 52 /* 53 * Return the network number from an internet address. 54 */ 55 u_long 56 in_netof(in) 57 struct in_addr in; 58 { 59 register u_long i = ntohl(in.s_addr); 60 register u_long net; 61 register struct in_ifaddr *ia; 62 63 if (IN_CLASSA(i)) 64 net = i & IN_CLASSA_NET; 65 else if (IN_CLASSB(i)) 66 net = i & IN_CLASSB_NET; 67 else if (IN_CLASSC(i)) 68 net = i & IN_CLASSC_NET; 69 else if (IN_CLASSD(i)) 70 net = i & IN_CLASSD_NET; 71 else 72 return (0); 73 74 /* 75 * Check whether network is a subnet; 76 * if so, return subnet number. 77 */ 78 for (ia = in_ifaddr; ia; ia = ia->ia_next) 79 if (net == ia->ia_net) 80 return (i & ia->ia_subnetmask); 81 return (net); 82 } 83 84 /* 85 * Compute and save network mask as sockaddr from an internet address. 86 */ 87 in_sockmaskof(in, sockmask) 88 struct in_addr in; 89 register struct sockaddr_in *sockmask; 90 { 91 register u_long net; 92 register u_long mask; 93 { 94 register u_long i = ntohl(in.s_addr); 95 96 if (i == 0) 97 net = 0, mask = 0; 98 else if (IN_CLASSA(i)) 99 net = i & IN_CLASSA_NET, mask = IN_CLASSA_NET; 100 else if (IN_CLASSB(i)) 101 net = i & IN_CLASSB_NET, mask = IN_CLASSB_NET; 102 else if (IN_CLASSC(i)) 103 net = i & IN_CLASSC_NET, mask = IN_CLASSC_NET; 104 else 105 net = i, mask = -1; 106 } 107 { 108 register struct in_ifaddr *ia; 109 /* 110 * Check whether network is a subnet; 111 * if so, return subnet number. 112 */ 113 for (ia = in_ifaddr; ia; ia = ia->ia_next) 114 if (net == ia->ia_net) 115 mask = ia->ia_subnetmask; 116 } 117 { 118 register char *cpbase = (char *)&(sockmask->sin_addr); 119 register char *cp = (char *)(1 + &(sockmask->sin_addr)); 120 121 sockmask->sin_addr.s_addr = htonl(mask); 122 sockmask->sin_len = 0; 123 while (--cp >= cpbase) 124 if (*cp) { 125 sockmask->sin_len = 1 + cp - (caddr_t)sockmask; 126 break; 127 } 128 } 129 } 130 131 #ifndef SUBNETSARELOCAL 132 #define SUBNETSARELOCAL 1 133 #endif 134 int subnetsarelocal = SUBNETSARELOCAL; 135 /* 136 * Return 1 if an internet address is for a ``local'' host 137 * (one to which we have a connection). If subnetsarelocal 138 * is true, this includes other subnets of the local net. 139 * Otherwise, it includes only the directly-connected (sub)nets. 140 */ 141 in_localaddr(in) 142 struct in_addr in; 143 { 144 register u_long i = ntohl(in.s_addr); 145 register struct in_ifaddr *ia; 146 147 if (subnetsarelocal) { 148 for (ia = in_ifaddr; ia; ia = ia->ia_next) 149 if ((i & ia->ia_netmask) == ia->ia_net) 150 return (1); 151 } else { 152 for (ia = in_ifaddr; ia; ia = ia->ia_next) 153 if ((i & ia->ia_subnetmask) == ia->ia_subnet) 154 return (1); 155 } 156 return (0); 157 } 158 159 /* 160 * Determine whether an IP address is in a reserved set of addresses 161 * that may not be forwarded, or whether datagrams to that destination 162 * may be forwarded. 163 */ 164 in_canforward(in) 165 struct in_addr in; 166 { 167 register u_long i = ntohl(in.s_addr); 168 register u_long net; 169 170 if (IN_EXPERIMENTAL(i) || IN_MULTICAST(i)) 171 return (0); 172 if (IN_CLASSA(i)) { 173 net = i & IN_CLASSA_NET; 174 if (net == 0 || net == (IN_LOOPBACKNET << IN_CLASSA_NSHIFT)) 175 return (0); 176 } 177 return (1); 178 } 179 180 /* 181 * Trim a mask in a sockaddr 182 */ 183 void 184 in_socktrim(ap) 185 struct sockaddr_in *ap; 186 { 187 register char *cplim = (char *) &ap->sin_addr; 188 register char *cp = (char *) (&ap->sin_addr + 1); 189 190 ap->sin_len = 0; 191 while (--cp > cplim) 192 if (*cp) { 193 (ap)->sin_len = cp - (char *) (ap) + 1; 194 break; 195 } 196 } 197 198 int in_interfaces; /* number of external internet interfaces */ 199 extern struct ifnet loif; 200 201 /* 202 * Generic internet control operations (ioctl's). 203 * Ifp is 0 if not an interface-specific ioctl. 204 */ 205 /* ARGSUSED */ 206 in_control(so, cmd, data, ifp) 207 struct socket *so; 208 int cmd; 209 caddr_t data; 210 register struct ifnet *ifp; 211 { 212 register struct ifreq *ifr = (struct ifreq *)data; 213 register struct in_ifaddr *ia = 0; 214 register struct ifaddr *ifa; 215 struct in_ifaddr *oia; 216 struct in_aliasreq *ifra = (struct in_aliasreq *)data; 217 struct sockaddr_in oldaddr; 218 int error, hostIsNew, maskIsNew; 219 u_long i; 220 221 /* 222 * Find address for this interface, if it exists. 223 */ 224 if (ifp) 225 for (ia = in_ifaddr; ia; ia = ia->ia_next) 226 if (ia->ia_ifp == ifp) 227 break; 228 229 switch (cmd) { 230 231 case SIOCAIFADDR: 232 case SIOCDIFADDR: 233 if (ifra->ifra_addr.sin_family == AF_INET) 234 for (oia = ia; ia; ia = ia->ia_next) { 235 if (ia->ia_ifp == ifp && 236 ia->ia_addr.sin_addr.s_addr == 237 ifra->ifra_addr.sin_addr.s_addr) 238 break; 239 } 240 if (cmd == SIOCDIFADDR && ia == 0) 241 return (EADDRNOTAVAIL); 242 /* FALLTHROUGH */ 243 case SIOCSIFADDR: 244 case SIOCSIFNETMASK: 245 case SIOCSIFDSTADDR: 246 if ((so->so_state & SS_PRIV) == 0) 247 return (EPERM); 248 249 if (ifp == 0) 250 panic("in_control"); 251 if (ia == (struct in_ifaddr *)0) { 252 oia = (struct in_ifaddr *) 253 malloc(sizeof *oia, M_IFADDR, M_WAITOK); 254 if (oia == (struct in_ifaddr *)NULL) 255 return (ENOBUFS); 256 bzero((caddr_t)oia, sizeof *oia); 257 if (ia = in_ifaddr) { 258 for ( ; ia->ia_next; ia = ia->ia_next) 259 continue; 260 ia->ia_next = oia; 261 } else 262 in_ifaddr = oia; 263 ia = oia; 264 if (ifa = ifp->if_addrlist) { 265 for ( ; ifa->ifa_next; ifa = ifa->ifa_next) 266 continue; 267 ifa->ifa_next = (struct ifaddr *) ia; 268 } else 269 ifp->if_addrlist = (struct ifaddr *) ia; 270 ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr; 271 ia->ia_ifa.ifa_dstaddr 272 = (struct sockaddr *)&ia->ia_dstaddr; 273 ia->ia_ifa.ifa_netmask 274 = (struct sockaddr *)&ia->ia_sockmask; 275 ia->ia_sockmask.sin_len = 8; 276 if (ifp->if_flags & IFF_BROADCAST) { 277 ia->ia_broadaddr.sin_len = sizeof(ia->ia_addr); 278 ia->ia_broadaddr.sin_family = AF_INET; 279 } 280 ia->ia_ifp = ifp; 281 if (ifp != &loif) 282 in_interfaces++; 283 } 284 break; 285 286 case SIOCSIFBRDADDR: 287 if ((so->so_state & SS_PRIV) == 0) 288 return (EPERM); 289 /* FALLTHROUGH */ 290 291 case SIOCGIFADDR: 292 case SIOCGIFNETMASK: 293 case SIOCGIFDSTADDR: 294 case SIOCGIFBRDADDR: 295 if (ia == (struct in_ifaddr *)0) 296 return (EADDRNOTAVAIL); 297 break; 298 } 299 switch (cmd) { 300 301 case SIOCGIFADDR: 302 *((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_addr; 303 break; 304 305 case SIOCGIFBRDADDR: 306 if ((ifp->if_flags & IFF_BROADCAST) == 0) 307 return (EINVAL); 308 *((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_broadaddr; 309 break; 310 311 case SIOCGIFDSTADDR: 312 if ((ifp->if_flags & IFF_POINTOPOINT) == 0) 313 return (EINVAL); 314 *((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_dstaddr; 315 break; 316 317 case SIOCGIFNETMASK: 318 *((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_sockmask; 319 break; 320 321 case SIOCSIFDSTADDR: 322 if ((ifp->if_flags & IFF_POINTOPOINT) == 0) 323 return (EINVAL); 324 oldaddr = ia->ia_dstaddr; 325 ia->ia_dstaddr = *(struct sockaddr_in *)&ifr->ifr_dstaddr; 326 if (ifp->if_ioctl && (error = (*ifp->if_ioctl) 327 (ifp, SIOCSIFDSTADDR, (caddr_t)ia))) { 328 ia->ia_dstaddr = oldaddr; 329 return (error); 330 } 331 if (ia->ia_flags & IFA_ROUTE) { 332 ia->ia_ifa.ifa_dstaddr = (struct sockaddr *)&oldaddr; 333 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST); 334 ia->ia_ifa.ifa_dstaddr = 335 (struct sockaddr *)&ia->ia_dstaddr; 336 rtinit(&(ia->ia_ifa), (int)RTM_ADD, RTF_HOST|RTF_UP); 337 } 338 break; 339 340 case SIOCSIFBRDADDR: 341 if ((ifp->if_flags & IFF_BROADCAST) == 0) 342 return (EINVAL); 343 ia->ia_broadaddr = *(struct sockaddr_in *)&ifr->ifr_broadaddr; 344 break; 345 346 case SIOCSIFADDR: 347 return (in_ifinit(ifp, ia, 348 (struct sockaddr_in *) &ifr->ifr_addr, 1)); 349 350 case SIOCSIFNETMASK: 351 i = ifra->ifra_addr.sin_addr.s_addr; 352 ia->ia_subnetmask = ntohl(ia->ia_sockmask.sin_addr.s_addr = i); 353 break; 354 355 case SIOCAIFADDR: 356 maskIsNew = 0; 357 hostIsNew = 1; 358 error = 0; 359 if (ia->ia_addr.sin_family == AF_INET) { 360 if (ifra->ifra_addr.sin_len == 0) { 361 ifra->ifra_addr = ia->ia_addr; 362 hostIsNew = 0; 363 } else if (ifra->ifra_addr.sin_addr.s_addr == 364 ia->ia_addr.sin_addr.s_addr) 365 hostIsNew = 0; 366 } 367 if (ifra->ifra_mask.sin_len) { 368 in_ifscrub(ifp, ia); 369 ia->ia_sockmask = ifra->ifra_mask; 370 ia->ia_subnetmask = 371 ntohl(ia->ia_sockmask.sin_addr.s_addr); 372 maskIsNew = 1; 373 } 374 if ((ifp->if_flags & IFF_POINTOPOINT) && 375 (ifra->ifra_dstaddr.sin_family == AF_INET)) { 376 in_ifscrub(ifp, ia); 377 ia->ia_dstaddr = ifra->ifra_dstaddr; 378 maskIsNew = 1; /* We lie; but the effect's the same */ 379 } 380 if (ifra->ifra_addr.sin_family == AF_INET && 381 (hostIsNew || maskIsNew)) 382 error = in_ifinit(ifp, ia, &ifra->ifra_addr, 0); 383 if ((ifp->if_flags & IFF_BROADCAST) && 384 (ifra->ifra_broadaddr.sin_family == AF_INET)) 385 ia->ia_broadaddr = ifra->ifra_broadaddr; 386 return (error); 387 388 case SIOCDIFADDR: 389 in_ifscrub(ifp, ia); 390 if ((ifa = ifp->if_addrlist) == (struct ifaddr *)ia) 391 ifp->if_addrlist = ifa->ifa_next; 392 else { 393 while (ifa->ifa_next && 394 (ifa->ifa_next != (struct ifaddr *)ia)) 395 ifa = ifa->ifa_next; 396 if (ifa->ifa_next) 397 ifa->ifa_next = ((struct ifaddr *)ia)->ifa_next; 398 else 399 printf("Couldn't unlink inifaddr from ifp\n"); 400 } 401 oia = ia; 402 if (oia == (ia = in_ifaddr)) 403 in_ifaddr = ia->ia_next; 404 else { 405 while (ia->ia_next && (ia->ia_next != oia)) 406 ia = ia->ia_next; 407 if (ia->ia_next) 408 ia->ia_next = oia->ia_next; 409 else 410 printf("Didn't unlink inifadr from list\n"); 411 } 412 IFAFREE((&oia->ia_ifa)); 413 break; 414 415 default: 416 if (ifp == 0 || ifp->if_ioctl == 0) 417 return (EOPNOTSUPP); 418 return ((*ifp->if_ioctl)(ifp, cmd, data)); 419 } 420 return (0); 421 } 422 423 /* 424 * Delete any existing route for an interface. 425 */ 426 in_ifscrub(ifp, ia) 427 register struct ifnet *ifp; 428 register struct in_ifaddr *ia; 429 { 430 431 if ((ia->ia_flags & IFA_ROUTE) == 0) 432 return; 433 if (ifp->if_flags & (IFF_LOOPBACK|IFF_POINTOPOINT)) 434 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST); 435 else 436 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, 0); 437 ia->ia_flags &= ~IFA_ROUTE; 438 } 439 440 /* 441 * Initialize an interface's internet address 442 * and routing table entry. 443 */ 444 in_ifinit(ifp, ia, sin, scrub) 445 register struct ifnet *ifp; 446 register struct in_ifaddr *ia; 447 struct sockaddr_in *sin; 448 int scrub; 449 { 450 register u_long i = ntohl(sin->sin_addr.s_addr); 451 struct sockaddr_in oldaddr; 452 int s = splimp(), flags = RTF_UP, error, ether_output(); 453 void arp_rtrequest(); 454 455 oldaddr = ia->ia_addr; 456 ia->ia_addr = *sin; 457 /* 458 * Give the interface a chance to initialize 459 * if this is its first address, 460 * and to validate the address if necessary. 461 */ 462 if (ifp->if_ioctl && 463 (error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia))) { 464 splx(s); 465 ia->ia_addr = oldaddr; 466 return (error); 467 } 468 if (ifp->if_output == ether_output) { /* XXX: Another Kludge */ 469 ia->ia_ifa.ifa_rtrequest = arp_rtrequest; 470 ia->ia_ifa.ifa_flags |= RTF_CLONING; 471 } 472 splx(s); 473 if (scrub) { 474 ia->ia_ifa.ifa_addr = (struct sockaddr *)&oldaddr; 475 in_ifscrub(ifp, ia); 476 ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr; 477 } 478 if (IN_CLASSA(i)) 479 ia->ia_netmask = IN_CLASSA_NET; 480 else if (IN_CLASSB(i)) 481 ia->ia_netmask = IN_CLASSB_NET; 482 else 483 ia->ia_netmask = IN_CLASSC_NET; 484 ia->ia_net = i & ia->ia_netmask; 485 /* 486 * The subnet mask includes at least the standard network part, 487 * but may already have been set to a larger value. 488 */ 489 ia->ia_subnetmask |= ia->ia_netmask; 490 ia->ia_subnet = i & ia->ia_subnetmask; 491 ia->ia_sockmask.sin_addr.s_addr = htonl(ia->ia_subnetmask); 492 in_socktrim(&ia->ia_sockmask); 493 /* 494 * Add route for the network. 495 */ 496 ia->ia_ifa.ifa_metric = ifp->if_metric; 497 if (ifp->if_flags & IFF_BROADCAST) { 498 ia->ia_broadaddr.sin_addr.s_addr = 499 htonl(ia->ia_subnet | ~ia->ia_subnetmask); 500 ia->ia_netbroadcast.s_addr = 501 htonl(ia->ia_net | ~ ia->ia_netmask); 502 } else if (ifp->if_flags & IFF_LOOPBACK) { 503 ia->ia_ifa.ifa_dstaddr = ia->ia_ifa.ifa_addr; 504 flags |= RTF_HOST; 505 } else if (ifp->if_flags & IFF_POINTOPOINT) { 506 if (ia->ia_dstaddr.sin_family != AF_INET) 507 return (0); 508 flags |= RTF_HOST; 509 } 510 if ((error = rtinit(&(ia->ia_ifa), (int)RTM_ADD, flags)) == 0) 511 ia->ia_flags |= IFA_ROUTE; 512 /* 513 * If the interface supports multicast, join the "all hosts" 514 * multicast group on that interface. 515 */ 516 if (ifp->if_flags & IFF_MULTICAST) { 517 struct in_addr addr; 518 519 addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP); 520 in_addmulti(&addr, ifp); 521 } 522 return (error); 523 } 524 525 526 /* 527 * Return 1 if the address might be a local broadcast address. 528 */ 529 in_broadcast(in, ifp) 530 struct in_addr in; 531 struct ifnet *ifp; 532 { 533 register struct ifaddr *ifa; 534 u_long t; 535 536 if (in.s_addr == INADDR_BROADCAST || 537 in.s_addr == INADDR_ANY) 538 return 1; 539 if ((ifp->if_flags & IFF_BROADCAST) == 0) 540 return 0; 541 t = ntohl(in.s_addr); 542 /* 543 * Look through the list of addresses for a match 544 * with a broadcast address. 545 */ 546 #define ia ((struct in_ifaddr *)ifa) 547 for (ifa = ifp->if_addrlist; ifa; ifa = ifa->ifa_next) 548 if (ifa->ifa_addr->sa_family == AF_INET && 549 (in.s_addr == ia->ia_broadaddr.sin_addr.s_addr || 550 in.s_addr == ia->ia_netbroadcast.s_addr || 551 /* 552 * Check for old-style (host 0) broadcast. 553 */ 554 t == ia->ia_subnet || t == ia->ia_net)) 555 return 1; 556 return 0; 557 #undef ia 558 } 559 /* 560 * Add an address to the list of IP multicast addresses for a given interface. 561 */ 562 struct in_multi * 563 in_addmulti(ap, ifp) 564 register struct in_addr *ap; 565 register struct ifnet *ifp; 566 { 567 register struct in_multi *inm; 568 struct ifreq ifr; 569 struct in_ifaddr *ia; 570 int s = splnet(); 571 572 /* 573 * See if address already in list. 574 */ 575 IN_LOOKUP_MULTI(*ap, ifp, inm); 576 if (inm != NULL) { 577 /* 578 * Found it; just increment the reference count. 579 */ 580 ++inm->inm_refcount; 581 } 582 else { 583 /* 584 * New address; allocate a new multicast record 585 * and link it into the interface's multicast list. 586 */ 587 inm = (struct in_multi *)malloc(sizeof(*inm), 588 M_IPMADDR, M_NOWAIT); 589 if (inm == NULL) { 590 splx(s); 591 return (NULL); 592 } 593 inm->inm_addr = *ap; 594 inm->inm_ifp = ifp; 595 inm->inm_refcount = 1; 596 IFP_TO_IA(ifp, ia); 597 if (ia == NULL) { 598 free(inm, M_IPMADDR); 599 splx(s); 600 return (NULL); 601 } 602 inm->inm_ia = ia; 603 inm->inm_next = ia->ia_multiaddrs; 604 ia->ia_multiaddrs = inm; 605 /* 606 * Ask the network driver to update its multicast reception 607 * filter appropriately for the new address. 608 */ 609 ((struct sockaddr_in *)&ifr.ifr_addr)->sin_family = AF_INET; 610 ((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr = *ap; 611 if ((ifp->if_ioctl == NULL) || 612 (*ifp->if_ioctl)(ifp, SIOCADDMULTI,(caddr_t)&ifr) != 0) { 613 ia->ia_multiaddrs = inm->inm_next; 614 free(inm, M_IPMADDR); 615 splx(s); 616 return (NULL); 617 } 618 /* 619 * Let IGMP know that we have joined a new IP multicast group. 620 */ 621 igmp_joingroup(inm); 622 } 623 splx(s); 624 return (inm); 625 } 626 627 /* 628 * Delete a multicast address record. 629 */ 630 int 631 in_delmulti(inm) 632 register struct in_multi *inm; 633 { 634 register struct in_multi **p; 635 struct ifreq ifr; 636 int s = splnet(); 637 638 if (--inm->inm_refcount == 0) { 639 /* 640 * No remaining claims to this record; let IGMP know that 641 * we are leaving the multicast group. 642 */ 643 igmp_leavegroup(inm); 644 /* 645 * Unlink from list. 646 */ 647 for (p = &inm->inm_ia->ia_multiaddrs; 648 *p != inm; 649 p = &(*p)->inm_next) 650 continue; 651 *p = (*p)->inm_next; 652 /* 653 * Notify the network driver to update its multicast reception 654 * filter. 655 */ 656 ((struct sockaddr_in *)&(ifr.ifr_addr))->sin_family = AF_INET; 657 ((struct sockaddr_in *)&(ifr.ifr_addr))->sin_addr = 658 inm->inm_addr; 659 (*inm->inm_ifp->if_ioctl)(inm->inm_ifp, SIOCDELMULTI, 660 (caddr_t)&ifr); 661 free(inm, M_IPMADDR); 662 } 663 splx(s); 664 } 665 #endif 666