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 7.32 (Berkeley) 04/08/93 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 * Return the network number from an internet address. 28 */ 29 u_long 30 in_netof(in) 31 struct in_addr in; 32 { 33 register u_long i = ntohl(in.s_addr); 34 register u_long net; 35 register struct in_ifaddr *ia; 36 37 if (IN_CLASSA(i)) 38 net = i & IN_CLASSA_NET; 39 else if (IN_CLASSB(i)) 40 net = i & IN_CLASSB_NET; 41 else if (IN_CLASSC(i)) 42 net = i & IN_CLASSC_NET; 43 else if (IN_CLASSD(i)) 44 net = i & IN_CLASSD_NET; 45 else 46 return (0); 47 48 /* 49 * Check whether network is a subnet; 50 * if so, return subnet number. 51 */ 52 for (ia = in_ifaddr; ia; ia = ia->ia_next) 53 if (net == ia->ia_net) 54 return (i & ia->ia_subnetmask); 55 return (net); 56 } 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 in_localaddr(in) 69 struct in_addr in; 70 { 71 register u_long i = ntohl(in.s_addr); 72 register struct in_ifaddr *ia; 73 74 if (subnetsarelocal) { 75 for (ia = in_ifaddr; ia; ia = ia->ia_next) 76 if ((i & ia->ia_netmask) == ia->ia_net) 77 return (1); 78 } else { 79 for (ia = in_ifaddr; ia; ia = ia->ia_next) 80 if ((i & 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 in_canforward(in) 92 struct in_addr in; 93 { 94 register u_long i = ntohl(in.s_addr); 95 register u_long net; 96 97 if (IN_EXPERIMENTAL(i) || IN_MULTICAST(i)) 98 return (0); 99 if (IN_CLASSA(i)) { 100 net = i & IN_CLASSA_NET; 101 if (net == 0 || net == (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 extern struct ifnet loif; 127 128 /* 129 * Generic internet control operations (ioctl's). 130 * Ifp is 0 if not an interface-specific ioctl. 131 */ 132 /* ARGSUSED */ 133 in_control(so, cmd, data, ifp) 134 struct socket *so; 135 int 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 u_long i; 147 148 /* 149 * Find address for this interface, if it exists. 150 */ 151 if (ifp) 152 for (ia = in_ifaddr; ia; ia = ia->ia_next) 153 if (ia->ia_ifp == ifp) 154 break; 155 156 switch (cmd) { 157 158 case SIOCAIFADDR: 159 case SIOCDIFADDR: 160 if (ifra->ifra_addr.sin_family == AF_INET) 161 for (oia = ia; ia; ia = ia->ia_next) { 162 if (ia->ia_ifp == ifp && 163 ia->ia_addr.sin_addr.s_addr == 164 ifra->ifra_addr.sin_addr.s_addr) 165 break; 166 } 167 if (cmd == SIOCDIFADDR && ia == 0) 168 return (EADDRNOTAVAIL); 169 /* FALLTHROUGH */ 170 case SIOCSIFADDR: 171 case SIOCSIFNETMASK: 172 case SIOCSIFDSTADDR: 173 if ((so->so_state & SS_PRIV) == 0) 174 return (EPERM); 175 176 if (ifp == 0) 177 panic("in_control"); 178 if (ia == (struct in_ifaddr *)0) { 179 oia = (struct in_ifaddr *) 180 malloc(sizeof *oia, M_IFADDR, M_WAITOK); 181 if (oia == (struct in_ifaddr *)NULL) 182 return (ENOBUFS); 183 bzero((caddr_t)oia, sizeof *oia); 184 if (ia = in_ifaddr) { 185 for ( ; ia->ia_next; ia = ia->ia_next) 186 continue; 187 ia->ia_next = oia; 188 } else 189 in_ifaddr = oia; 190 ia = oia; 191 if (ifa = ifp->if_addrlist) { 192 for ( ; ifa->ifa_next; ifa = ifa->ifa_next) 193 continue; 194 ifa->ifa_next = (struct ifaddr *) ia; 195 } else 196 ifp->if_addrlist = (struct ifaddr *) ia; 197 ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr; 198 ia->ia_ifa.ifa_dstaddr 199 = (struct sockaddr *)&ia->ia_dstaddr; 200 ia->ia_ifa.ifa_netmask 201 = (struct sockaddr *)&ia->ia_sockmask; 202 ia->ia_sockmask.sin_len = 8; 203 if (ifp->if_flags & IFF_BROADCAST) { 204 ia->ia_broadaddr.sin_len = sizeof(ia->ia_addr); 205 ia->ia_broadaddr.sin_family = AF_INET; 206 } 207 ia->ia_ifp = ifp; 208 if (ifp != &loif) 209 in_interfaces++; 210 } 211 break; 212 213 case SIOCSIFBRDADDR: 214 if ((so->so_state & SS_PRIV) == 0) 215 return (EPERM); 216 /* FALLTHROUGH */ 217 218 case SIOCGIFADDR: 219 case SIOCGIFNETMASK: 220 case SIOCGIFDSTADDR: 221 case SIOCGIFBRDADDR: 222 if (ia == (struct in_ifaddr *)0) 223 return (EADDRNOTAVAIL); 224 break; 225 } 226 switch (cmd) { 227 228 case SIOCGIFADDR: 229 *((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_addr; 230 break; 231 232 case SIOCGIFBRDADDR: 233 if ((ifp->if_flags & IFF_BROADCAST) == 0) 234 return (EINVAL); 235 *((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_broadaddr; 236 break; 237 238 case SIOCGIFDSTADDR: 239 if ((ifp->if_flags & IFF_POINTOPOINT) == 0) 240 return (EINVAL); 241 *((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_dstaddr; 242 break; 243 244 case SIOCGIFNETMASK: 245 *((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_sockmask; 246 break; 247 248 case SIOCSIFDSTADDR: 249 if ((ifp->if_flags & IFF_POINTOPOINT) == 0) 250 return (EINVAL); 251 oldaddr = ia->ia_dstaddr; 252 ia->ia_dstaddr = *(struct sockaddr_in *)&ifr->ifr_dstaddr; 253 if (ifp->if_ioctl && (error = (*ifp->if_ioctl) 254 (ifp, SIOCSIFDSTADDR, (caddr_t)ia))) { 255 ia->ia_dstaddr = oldaddr; 256 return (error); 257 } 258 if (ia->ia_flags & IFA_ROUTE) { 259 ia->ia_ifa.ifa_dstaddr = (struct sockaddr *)&oldaddr; 260 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST); 261 ia->ia_ifa.ifa_dstaddr = 262 (struct sockaddr *)&ia->ia_dstaddr; 263 rtinit(&(ia->ia_ifa), (int)RTM_ADD, RTF_HOST|RTF_UP); 264 } 265 break; 266 267 case SIOCSIFBRDADDR: 268 if ((ifp->if_flags & IFF_BROADCAST) == 0) 269 return (EINVAL); 270 ia->ia_broadaddr = *(struct sockaddr_in *)&ifr->ifr_broadaddr; 271 break; 272 273 case SIOCSIFADDR: 274 return (in_ifinit(ifp, ia, 275 (struct sockaddr_in *) &ifr->ifr_addr, 1)); 276 277 case SIOCSIFNETMASK: 278 i = ifra->ifra_addr.sin_addr.s_addr; 279 ia->ia_subnetmask = ntohl(ia->ia_sockmask.sin_addr.s_addr = i); 280 break; 281 282 case SIOCAIFADDR: 283 maskIsNew = 0; 284 hostIsNew = 1; 285 error = 0; 286 if (ia->ia_addr.sin_family == AF_INET) { 287 if (ifra->ifra_addr.sin_len == 0) { 288 ifra->ifra_addr = ia->ia_addr; 289 hostIsNew = 0; 290 } else if (ifra->ifra_addr.sin_addr.s_addr == 291 ia->ia_addr.sin_addr.s_addr) 292 hostIsNew = 0; 293 } 294 if (ifra->ifra_mask.sin_len) { 295 in_ifscrub(ifp, ia); 296 ia->ia_sockmask = ifra->ifra_mask; 297 ia->ia_subnetmask = 298 ntohl(ia->ia_sockmask.sin_addr.s_addr); 299 maskIsNew = 1; 300 } 301 if ((ifp->if_flags & IFF_POINTOPOINT) && 302 (ifra->ifra_dstaddr.sin_family == AF_INET)) { 303 in_ifscrub(ifp, ia); 304 ia->ia_dstaddr = ifra->ifra_dstaddr; 305 maskIsNew = 1; /* We lie; but the effect's the same */ 306 } 307 if (ifra->ifra_addr.sin_family == AF_INET && 308 (hostIsNew || maskIsNew)) 309 error = in_ifinit(ifp, ia, &ifra->ifra_addr, 0); 310 if ((ifp->if_flags & IFF_BROADCAST) && 311 (ifra->ifra_broadaddr.sin_family == AF_INET)) 312 ia->ia_broadaddr = ifra->ifra_broadaddr; 313 return (error); 314 315 case SIOCDIFADDR: 316 in_ifscrub(ifp, ia); 317 if ((ifa = ifp->if_addrlist) == (struct ifaddr *)ia) 318 ifp->if_addrlist = ifa->ifa_next; 319 else { 320 while (ifa->ifa_next && 321 (ifa->ifa_next != (struct ifaddr *)ia)) 322 ifa = ifa->ifa_next; 323 if (ifa->ifa_next) 324 ifa->ifa_next = ((struct ifaddr *)ia)->ifa_next; 325 else 326 printf("Couldn't unlink inifaddr from ifp\n"); 327 } 328 oia = ia; 329 if (oia == (ia = in_ifaddr)) 330 in_ifaddr = ia->ia_next; 331 else { 332 while (ia->ia_next && (ia->ia_next != oia)) 333 ia = ia->ia_next; 334 if (ia->ia_next) 335 ia->ia_next = oia->ia_next; 336 else 337 printf("Didn't unlink inifadr from list\n"); 338 } 339 IFAFREE((&oia->ia_ifa)); 340 break; 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 in_ifscrub(ifp, ia) 354 register struct ifnet *ifp; 355 register struct in_ifaddr *ia; 356 { 357 358 if ((ia->ia_flags & IFA_ROUTE) == 0) 359 return; 360 if (ifp->if_flags & (IFF_LOOPBACK|IFF_POINTOPOINT)) 361 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST); 362 else 363 rtinit(&(ia->ia_ifa), (int)RTM_DELETE, 0); 364 ia->ia_flags &= ~IFA_ROUTE; 365 } 366 367 /* 368 * Initialize an interface's internet address 369 * and routing table entry. 370 */ 371 in_ifinit(ifp, ia, sin, scrub) 372 register struct ifnet *ifp; 373 register struct in_ifaddr *ia; 374 struct sockaddr_in *sin; 375 int scrub; 376 { 377 register u_long i = ntohl(sin->sin_addr.s_addr); 378 struct sockaddr_in oldaddr; 379 int s = splimp(), flags = RTF_UP, error, ether_output(); 380 void arp_rtrequest(); 381 382 oldaddr = ia->ia_addr; 383 ia->ia_addr = *sin; 384 /* 385 * Give the interface a chance to initialize 386 * if this is its first address, 387 * and to validate the address if necessary. 388 */ 389 if (ifp->if_ioctl && 390 (error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia))) { 391 splx(s); 392 ia->ia_addr = oldaddr; 393 return (error); 394 } 395 if (ifp->if_output == ether_output) { /* XXX: Another Kludge */ 396 ia->ia_ifa.ifa_rtrequest = arp_rtrequest; 397 ia->ia_ifa.ifa_flags |= RTF_CLONING; 398 } 399 splx(s); 400 if (scrub) { 401 ia->ia_ifa.ifa_addr = (struct sockaddr *)&oldaddr; 402 in_ifscrub(ifp, ia); 403 ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr; 404 } 405 if (IN_CLASSA(i)) 406 ia->ia_netmask = IN_CLASSA_NET; 407 else if (IN_CLASSB(i)) 408 ia->ia_netmask = IN_CLASSB_NET; 409 else 410 ia->ia_netmask = IN_CLASSC_NET; 411 ia->ia_net = i & ia->ia_netmask; 412 /* 413 * The subnet mask includes at least the standard network part, 414 * but may already have been set to a larger value. 415 */ 416 ia->ia_subnetmask |= ia->ia_netmask; 417 ia->ia_subnet = i & ia->ia_subnetmask; 418 ia->ia_sockmask.sin_addr.s_addr = htonl(ia->ia_subnetmask); 419 in_socktrim(&ia->ia_sockmask); 420 /* 421 * Add route for the network. 422 */ 423 ia->ia_ifa.ifa_metric = ifp->if_metric; 424 if (ifp->if_flags & IFF_BROADCAST) { 425 ia->ia_broadaddr.sin_addr.s_addr = 426 htonl(ia->ia_subnet | ~ia->ia_subnetmask); 427 ia->ia_netbroadcast.s_addr = 428 htonl(ia->ia_net | ~ ia->ia_netmask); 429 } else if (ifp->if_flags & IFF_LOOPBACK) { 430 ia->ia_ifa.ifa_dstaddr = ia->ia_ifa.ifa_addr; 431 flags |= RTF_HOST; 432 } else if (ifp->if_flags & IFF_POINTOPOINT) { 433 if (ia->ia_dstaddr.sin_family != AF_INET) 434 return (0); 435 flags |= RTF_HOST; 436 } 437 if ((error = rtinit(&(ia->ia_ifa), (int)RTM_ADD, flags)) == 0) 438 ia->ia_flags |= IFA_ROUTE; 439 /* 440 * If the interface supports multicast, join the "all hosts" 441 * multicast group on that interface. 442 */ 443 if (ifp->if_flags & IFF_MULTICAST) { 444 struct in_addr addr; 445 446 addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP); 447 in_addmulti(&addr, ifp); 448 } 449 return (error); 450 } 451 452 453 /* 454 * Return 1 if the address might be a local broadcast address. 455 */ 456 in_broadcast(in, ifp) 457 struct in_addr in; 458 struct ifnet *ifp; 459 { 460 register struct ifaddr *ifa; 461 u_long t; 462 463 if (in.s_addr == INADDR_BROADCAST || 464 in.s_addr == INADDR_ANY) 465 return 1; 466 if ((ifp->if_flags & IFF_BROADCAST) == 0) 467 return 0; 468 t = ntohl(in.s_addr); 469 /* 470 * Look through the list of addresses for a match 471 * with a broadcast address. 472 */ 473 #define ia ((struct in_ifaddr *)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 t == ia->ia_subnet || t == ia->ia_net)) 482 return 1; 483 return 0; 484 #undef ia 485 } 486 /* 487 * Add an address to the list of IP multicast addresses for a given interface. 488 */ 489 struct in_multi * 490 in_addmulti(ap, ifp) 491 register struct in_addr *ap; 492 register struct ifnet *ifp; 493 { 494 register struct in_multi *inm; 495 struct ifreq ifr; 496 struct in_ifaddr *ia; 497 int s = splnet(); 498 499 /* 500 * See if address already in list. 501 */ 502 IN_LOOKUP_MULTI(*ap, ifp, inm); 503 if (inm != NULL) { 504 /* 505 * Found it; just increment the reference count. 506 */ 507 ++inm->inm_refcount; 508 } 509 else { 510 /* 511 * New address; allocate a new multicast record 512 * and link it into the interface's multicast list. 513 */ 514 inm = (struct in_multi *)malloc(sizeof(*inm), 515 M_IPMADDR, M_NOWAIT); 516 if (inm == NULL) { 517 splx(s); 518 return (NULL); 519 } 520 inm->inm_addr = *ap; 521 inm->inm_ifp = ifp; 522 inm->inm_refcount = 1; 523 IFP_TO_IA(ifp, ia); 524 if (ia == NULL) { 525 free(inm, M_IPMADDR); 526 splx(s); 527 return (NULL); 528 } 529 inm->inm_ia = ia; 530 inm->inm_next = ia->ia_multiaddrs; 531 ia->ia_multiaddrs = inm; 532 /* 533 * Ask the network driver to update its multicast reception 534 * filter appropriately for the new address. 535 */ 536 ((struct sockaddr_in *)&ifr.ifr_addr)->sin_family = AF_INET; 537 ((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr = *ap; 538 if ((ifp->if_ioctl == NULL) || 539 (*ifp->if_ioctl)(ifp, SIOCADDMULTI,(caddr_t)&ifr) != 0) { 540 ia->ia_multiaddrs = inm->inm_next; 541 free(inm, M_IPMADDR); 542 splx(s); 543 return (NULL); 544 } 545 /* 546 * Let IGMP know that we have joined a new IP multicast group. 547 */ 548 igmp_joingroup(inm); 549 } 550 splx(s); 551 return (inm); 552 } 553 554 /* 555 * Delete a multicast address record. 556 */ 557 int 558 in_delmulti(inm) 559 register struct in_multi *inm; 560 { 561 register struct in_multi **p; 562 struct ifreq ifr; 563 int s = splnet(); 564 565 if (--inm->inm_refcount == 0) { 566 /* 567 * No remaining claims to this record; let IGMP know that 568 * we are leaving the multicast group. 569 */ 570 igmp_leavegroup(inm); 571 /* 572 * Unlink from list. 573 */ 574 for (p = &inm->inm_ia->ia_multiaddrs; 575 *p != inm; 576 p = &(*p)->inm_next) 577 continue; 578 *p = (*p)->inm_next; 579 /* 580 * Notify the network driver to update its multicast reception 581 * filter. 582 */ 583 ((struct sockaddr_in *)&(ifr.ifr_addr))->sin_family = AF_INET; 584 ((struct sockaddr_in *)&(ifr.ifr_addr))->sin_addr = 585 inm->inm_addr; 586 (*inm->inm_ifp->if_ioctl)(inm->inm_ifp, SIOCDELMULTI, 587 (caddr_t)&ifr); 588 free(inm, M_IPMADDR); 589 } 590 splx(s); 591 } 592 #endif 593