1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * Copyright (C) 2001 WIDE Project. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)in.c 8.4 (Berkeley) 1/9/95 33 */ 34 35 #include <sys/cdefs.h> 36 #include "opt_inet.h" 37 38 #define IN_HISTORICAL_NETS /* include class masks */ 39 40 #include <sys/param.h> 41 #include <sys/eventhandler.h> 42 #include <sys/systm.h> 43 #include <sys/sockio.h> 44 #include <sys/malloc.h> 45 #include <sys/priv.h> 46 #include <sys/socket.h> 47 #include <sys/jail.h> 48 #include <sys/kernel.h> 49 #include <sys/lock.h> 50 #include <sys/proc.h> 51 #include <sys/sysctl.h> 52 #include <sys/syslog.h> 53 #include <sys/sx.h> 54 55 #include <net/if.h> 56 #include <net/if_var.h> 57 #include <net/if_arp.h> 58 #include <net/if_dl.h> 59 #include <net/if_llatbl.h> 60 #include <net/if_private.h> 61 #include <net/if_types.h> 62 #include <net/route.h> 63 #include <net/route/nhop.h> 64 #include <net/route/route_ctl.h> 65 #include <net/vnet.h> 66 67 #include <netinet/if_ether.h> 68 #include <netinet/in.h> 69 #include <netinet/in_fib.h> 70 #include <netinet/in_var.h> 71 #include <netinet/in_pcb.h> 72 #include <netinet/ip_var.h> 73 #include <netinet/ip_carp.h> 74 #include <netinet/igmp_var.h> 75 #include <netinet/udp.h> 76 #include <netinet/udp_var.h> 77 78 #ifdef MAC 79 #include <security/mac/mac_framework.h> 80 #endif 81 82 static int in_aifaddr_ioctl(u_long, caddr_t, struct ifnet *, struct ucred *); 83 static int in_difaddr_ioctl(u_long, caddr_t, struct ifnet *, struct ucred *); 84 static int in_gifaddr_ioctl(u_long, caddr_t, struct ifnet *, struct ucred *); 85 86 static void in_socktrim(struct sockaddr_in *); 87 static void in_purgemaddrs(struct ifnet *); 88 89 static bool ia_need_loopback_route(const struct in_ifaddr *); 90 91 VNET_DEFINE_STATIC(int, nosameprefix); 92 #define V_nosameprefix VNET(nosameprefix) 93 SYSCTL_INT(_net_inet_ip, OID_AUTO, no_same_prefix, CTLFLAG_VNET | CTLFLAG_RW, 94 &VNET_NAME(nosameprefix), 0, 95 "Refuse to create same prefixes on different interfaces"); 96 97 VNET_DEFINE_STATIC(bool, broadcast_lowest); 98 #define V_broadcast_lowest VNET(broadcast_lowest) 99 SYSCTL_BOOL(_net_inet_ip, OID_AUTO, broadcast_lowest, CTLFLAG_VNET | CTLFLAG_RW, 100 &VNET_NAME(broadcast_lowest), 0, 101 "Treat lowest address on a subnet (host 0) as broadcast"); 102 103 VNET_DEFINE(bool, ip_allow_net240) = false; 104 #define V_ip_allow_net240 VNET(ip_allow_net240) 105 SYSCTL_BOOL(_net_inet_ip, OID_AUTO, allow_net240, 106 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip_allow_net240), 0, 107 "Allow use of Experimental addresses, aka Class E (240/4)"); 108 /* see https://datatracker.ietf.org/doc/draft-schoen-intarea-unicast-240 */ 109 110 VNET_DEFINE(bool, ip_allow_net0) = false; 111 SYSCTL_BOOL(_net_inet_ip, OID_AUTO, allow_net0, 112 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip_allow_net0), 0, 113 "Allow use of addresses in network 0/8"); 114 /* see https://datatracker.ietf.org/doc/draft-schoen-intarea-unicast-0 */ 115 116 VNET_DEFINE(uint32_t, in_loopback_mask) = IN_LOOPBACK_MASK_DFLT; 117 #define V_in_loopback_mask VNET(in_loopback_mask) 118 static int sysctl_loopback_prefixlen(SYSCTL_HANDLER_ARGS); 119 SYSCTL_PROC(_net_inet_ip, OID_AUTO, loopback_prefixlen, 120 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW, 121 NULL, 0, sysctl_loopback_prefixlen, "I", 122 "Prefix length of address space reserved for loopback"); 123 /* see https://datatracker.ietf.org/doc/draft-schoen-intarea-unicast-127 */ 124 125 VNET_DECLARE(struct inpcbinfo, ripcbinfo); 126 #define V_ripcbinfo VNET(ripcbinfo) 127 128 static struct sx in_control_sx; 129 SX_SYSINIT(in_control_sx, &in_control_sx, "in_control"); 130 131 /* 132 * Return 1 if an internet address is for a ``local'' host 133 * (one to which we have a connection). 134 */ 135 int 136 in_localaddr(struct in_addr in) 137 { 138 u_long i = ntohl(in.s_addr); 139 struct in_ifaddr *ia; 140 141 NET_EPOCH_ASSERT(); 142 143 CK_STAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) { 144 if ((i & ia->ia_subnetmask) == ia->ia_subnet) 145 return (1); 146 } 147 148 return (0); 149 } 150 151 /* 152 * Return 1 if an internet address is for the local host and configured 153 * on one of its interfaces. 154 */ 155 bool 156 in_localip(struct in_addr in) 157 { 158 struct in_ifaddr *ia; 159 160 NET_EPOCH_ASSERT(); 161 162 CK_LIST_FOREACH(ia, INADDR_HASH(in.s_addr), ia_hash) 163 if (IA_SIN(ia)->sin_addr.s_addr == in.s_addr) 164 return (true); 165 166 return (false); 167 } 168 169 /* 170 * Like in_localip(), but FIB-aware. 171 */ 172 bool 173 in_localip_fib(struct in_addr in, uint16_t fib) 174 { 175 struct in_ifaddr *ia; 176 177 NET_EPOCH_ASSERT(); 178 179 CK_LIST_FOREACH(ia, INADDR_HASH(in.s_addr), ia_hash) 180 if (IA_SIN(ia)->sin_addr.s_addr == in.s_addr && 181 ia->ia_ifa.ifa_ifp->if_fib == fib) 182 return (true); 183 184 return (false); 185 } 186 187 /* 188 * Return 1 if an internet address is configured on an interface. 189 */ 190 int 191 in_ifhasaddr(struct ifnet *ifp, struct in_addr in) 192 { 193 struct ifaddr *ifa; 194 struct in_ifaddr *ia; 195 196 NET_EPOCH_ASSERT(); 197 198 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 199 if (ifa->ifa_addr->sa_family != AF_INET) 200 continue; 201 ia = (struct in_ifaddr *)ifa; 202 if (ia->ia_addr.sin_addr.s_addr == in.s_addr) 203 return (1); 204 } 205 206 return (0); 207 } 208 209 /* 210 * Return a reference to the interface address which is different to 211 * the supplied one but with same IP address value. 212 */ 213 static struct in_ifaddr * 214 in_localip_more(struct in_ifaddr *original_ia) 215 { 216 struct epoch_tracker et; 217 in_addr_t original_addr = IA_SIN(original_ia)->sin_addr.s_addr; 218 uint32_t original_fib = original_ia->ia_ifa.ifa_ifp->if_fib; 219 struct in_ifaddr *ia; 220 221 NET_EPOCH_ENTER(et); 222 CK_LIST_FOREACH(ia, INADDR_HASH(original_addr), ia_hash) { 223 in_addr_t addr = IA_SIN(ia)->sin_addr.s_addr; 224 uint32_t fib = ia->ia_ifa.ifa_ifp->if_fib; 225 if (!V_rt_add_addr_allfibs && (original_fib != fib)) 226 continue; 227 if ((original_ia != ia) && (original_addr == addr)) { 228 ifa_ref(&ia->ia_ifa); 229 NET_EPOCH_EXIT(et); 230 return (ia); 231 } 232 } 233 NET_EPOCH_EXIT(et); 234 235 return (NULL); 236 } 237 238 /* 239 * Tries to find first IPv4 address in the provided fib. 240 * Prefers non-loopback addresses and return loopback IFF 241 * @loopback_ok is set. 242 * 243 * Returns ifa or NULL. 244 */ 245 struct in_ifaddr * 246 in_findlocal(uint32_t fibnum, bool loopback_ok) 247 { 248 struct in_ifaddr *ia = NULL, *ia_lo = NULL; 249 250 NET_EPOCH_ASSERT(); 251 252 CK_STAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) { 253 uint32_t ia_fib = ia->ia_ifa.ifa_ifp->if_fib; 254 if (!V_rt_add_addr_allfibs && (fibnum != ia_fib)) 255 continue; 256 257 if (!IN_LOOPBACK(ntohl(IA_SIN(ia)->sin_addr.s_addr))) 258 break; 259 if (loopback_ok) 260 ia_lo = ia; 261 } 262 263 if (ia == NULL) 264 ia = ia_lo; 265 266 return (ia); 267 } 268 269 /* 270 * Determine whether an IP address is in a reserved set of addresses 271 * that may not be forwarded, or whether datagrams to that destination 272 * may be forwarded. 273 */ 274 int 275 in_canforward(struct in_addr in) 276 { 277 u_long i = ntohl(in.s_addr); 278 279 if (IN_MULTICAST(i) || IN_LINKLOCAL(i) || IN_LOOPBACK(i)) 280 return (0); 281 if (IN_EXPERIMENTAL(i) && !V_ip_allow_net240) 282 return (0); 283 if (IN_ZERONET(i) && !V_ip_allow_net0) 284 return (0); 285 return (1); 286 } 287 288 /* 289 * Sysctl to manage prefix of reserved loopback network; translate 290 * to/from mask. The mask is always contiguous high-order 1 bits 291 * followed by all 0 bits. 292 */ 293 static int 294 sysctl_loopback_prefixlen(SYSCTL_HANDLER_ARGS) 295 { 296 int error, preflen; 297 298 /* ffs is 1-based; compensate. */ 299 preflen = 33 - ffs(V_in_loopback_mask); 300 error = sysctl_handle_int(oidp, &preflen, 0, req); 301 if (error || !req->newptr) 302 return (error); 303 if (preflen < 8 || preflen > 31) 304 return (EINVAL); 305 V_in_loopback_mask = 0xffffffff << (32 - preflen); 306 return (0); 307 } 308 309 /* 310 * Trim a mask in a sockaddr 311 */ 312 static void 313 in_socktrim(struct sockaddr_in *ap) 314 { 315 char *cplim = (char *) &ap->sin_addr; 316 char *cp = (char *) (&ap->sin_addr + 1); 317 318 ap->sin_len = 0; 319 while (--cp >= cplim) 320 if (*cp) { 321 (ap)->sin_len = cp - (char *) (ap) + 1; 322 break; 323 } 324 } 325 326 /* 327 * Generic internet control operations (ioctl's). 328 */ 329 int 330 in_control_ioctl(u_long cmd, void *data, struct ifnet *ifp, 331 struct ucred *cred) 332 { 333 struct ifreq *ifr = (struct ifreq *)data; 334 struct sockaddr_in *addr = (struct sockaddr_in *)&ifr->ifr_addr; 335 struct epoch_tracker et; 336 struct ifaddr *ifa; 337 struct in_ifaddr *ia; 338 int error; 339 340 if (ifp == NULL) 341 return (EADDRNOTAVAIL); 342 343 /* 344 * Filter out 4 ioctls we implement directly. Forward the rest 345 * to specific functions and ifp->if_ioctl(). 346 */ 347 switch (cmd) { 348 case SIOCGIFADDR: 349 case SIOCGIFBRDADDR: 350 case SIOCGIFDSTADDR: 351 case SIOCGIFNETMASK: 352 break; 353 case SIOCGIFALIAS: 354 sx_xlock(&in_control_sx); 355 error = in_gifaddr_ioctl(cmd, data, ifp, cred); 356 sx_xunlock(&in_control_sx); 357 return (error); 358 case SIOCDIFADDR: 359 sx_xlock(&in_control_sx); 360 error = in_difaddr_ioctl(cmd, data, ifp, cred); 361 sx_xunlock(&in_control_sx); 362 return (error); 363 case OSIOCAIFADDR: /* 9.x compat */ 364 case SIOCAIFADDR: 365 sx_xlock(&in_control_sx); 366 error = in_aifaddr_ioctl(cmd, data, ifp, cred); 367 sx_xunlock(&in_control_sx); 368 return (error); 369 case SIOCSIFADDR: 370 case SIOCSIFBRDADDR: 371 case SIOCSIFDSTADDR: 372 case SIOCSIFNETMASK: 373 /* We no longer support that old commands. */ 374 return (EINVAL); 375 default: 376 if (ifp->if_ioctl == NULL) 377 return (EOPNOTSUPP); 378 return ((*ifp->if_ioctl)(ifp, cmd, data)); 379 } 380 381 if (addr->sin_addr.s_addr != INADDR_ANY && 382 prison_check_ip4(cred, &addr->sin_addr) != 0) 383 return (EADDRNOTAVAIL); 384 385 /* 386 * Find address for this interface, if it exists. If an 387 * address was specified, find that one instead of the 388 * first one on the interface, if possible. 389 */ 390 NET_EPOCH_ENTER(et); 391 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 392 if (ifa->ifa_addr->sa_family != AF_INET) 393 continue; 394 ia = (struct in_ifaddr *)ifa; 395 if (ia->ia_addr.sin_addr.s_addr == addr->sin_addr.s_addr) 396 break; 397 } 398 if (ifa == NULL) 399 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) 400 if (ifa->ifa_addr->sa_family == AF_INET) { 401 ia = (struct in_ifaddr *)ifa; 402 if (prison_check_ip4(cred, 403 &ia->ia_addr.sin_addr) == 0) 404 break; 405 } 406 407 if (ifa == NULL) { 408 NET_EPOCH_EXIT(et); 409 return (EADDRNOTAVAIL); 410 } 411 412 error = 0; 413 switch (cmd) { 414 case SIOCGIFADDR: 415 *addr = ia->ia_addr; 416 break; 417 418 case SIOCGIFBRDADDR: 419 if ((ifp->if_flags & IFF_BROADCAST) == 0) { 420 error = EINVAL; 421 break; 422 } 423 *addr = ia->ia_broadaddr; 424 break; 425 426 case SIOCGIFDSTADDR: 427 if ((ifp->if_flags & IFF_POINTOPOINT) == 0) { 428 error = EINVAL; 429 break; 430 } 431 *addr = ia->ia_dstaddr; 432 break; 433 434 case SIOCGIFNETMASK: 435 *addr = ia->ia_sockmask; 436 break; 437 } 438 439 NET_EPOCH_EXIT(et); 440 441 return (error); 442 } 443 444 int 445 in_control(struct socket *so, u_long cmd, void *data, struct ifnet *ifp, 446 struct thread *td) 447 { 448 return (in_control_ioctl(cmd, data, ifp, td ? td->td_ucred : NULL)); 449 } 450 451 static int 452 in_aifaddr_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp, struct ucred *cred) 453 { 454 const struct in_aliasreq *ifra = (struct in_aliasreq *)data; 455 const struct sockaddr_in *addr = &ifra->ifra_addr; 456 const struct sockaddr_in *broadaddr = &ifra->ifra_broadaddr; 457 const struct sockaddr_in *mask = &ifra->ifra_mask; 458 const struct sockaddr_in *dstaddr = &ifra->ifra_dstaddr; 459 const int vhid = (cmd == SIOCAIFADDR) ? ifra->ifra_vhid : 0; 460 struct epoch_tracker et; 461 struct ifaddr *ifa; 462 struct in_ifaddr *ia; 463 bool iaIsFirst; 464 int error = 0; 465 466 error = priv_check_cred(cred, PRIV_NET_ADDIFADDR); 467 if (error) 468 return (error); 469 470 /* 471 * ifra_addr must be present and be of INET family. 472 * ifra_broadaddr/ifra_dstaddr and ifra_mask are optional. 473 */ 474 if (addr->sin_len != sizeof(struct sockaddr_in) || 475 addr->sin_family != AF_INET) 476 return (EINVAL); 477 if (broadaddr->sin_len != 0 && 478 (broadaddr->sin_len != sizeof(struct sockaddr_in) || 479 broadaddr->sin_family != AF_INET)) 480 return (EINVAL); 481 if (mask->sin_len != 0 && 482 (mask->sin_len != sizeof(struct sockaddr_in) || 483 mask->sin_family != AF_INET)) 484 return (EINVAL); 485 if ((ifp->if_flags & IFF_POINTOPOINT) && 486 (dstaddr->sin_len != sizeof(struct sockaddr_in) || 487 dstaddr->sin_addr.s_addr == INADDR_ANY)) 488 return (EDESTADDRREQ); 489 if (vhid != 0 && carp_attach_p == NULL) 490 return (EPROTONOSUPPORT); 491 492 #ifdef MAC 493 /* Check if a MAC policy disallows setting the IPv4 address. */ 494 error = mac_inet_check_add_addr(cred, &addr->sin_addr, ifp); 495 if (error != 0) 496 return (error); 497 #endif 498 499 /* 500 * See whether address already exist. 501 */ 502 iaIsFirst = true; 503 ia = NULL; 504 NET_EPOCH_ENTER(et); 505 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 506 struct in_ifaddr *it; 507 508 if (ifa->ifa_addr->sa_family != AF_INET) 509 continue; 510 511 it = (struct in_ifaddr *)ifa; 512 if (it->ia_addr.sin_addr.s_addr == addr->sin_addr.s_addr && 513 prison_check_ip4(cred, &addr->sin_addr) == 0) 514 ia = it; 515 else 516 iaIsFirst = false; 517 } 518 NET_EPOCH_EXIT(et); 519 520 if (ia != NULL) 521 (void )in_difaddr_ioctl(cmd, data, ifp, cred); 522 523 ifa = ifa_alloc(sizeof(struct in_ifaddr), M_WAITOK); 524 ia = (struct in_ifaddr *)ifa; 525 ifa->ifa_addr = (struct sockaddr *)&ia->ia_addr; 526 ifa->ifa_dstaddr = (struct sockaddr *)&ia->ia_dstaddr; 527 ifa->ifa_netmask = (struct sockaddr *)&ia->ia_sockmask; 528 callout_init_rw(&ia->ia_garp_timer, &ifp->if_addr_lock, 529 CALLOUT_RETURNUNLOCKED); 530 531 ia->ia_ifp = ifp; 532 ia->ia_addr = *addr; 533 if (mask->sin_len != 0) { 534 ia->ia_sockmask = *mask; 535 ia->ia_subnetmask = ntohl(ia->ia_sockmask.sin_addr.s_addr); 536 } else { 537 in_addr_t i = ntohl(addr->sin_addr.s_addr); 538 539 /* 540 * If netmask isn't supplied, use historical default. 541 * This is deprecated for interfaces other than loopback 542 * or point-to-point; warn in other cases. In the future 543 * we should return an error rather than warning. 544 */ 545 if ((ifp->if_flags & (IFF_POINTOPOINT | IFF_LOOPBACK)) == 0) 546 printf("%s: set address: WARNING: network mask " 547 "should be specified; using historical default\n", 548 ifp->if_xname); 549 if (IN_CLASSA(i)) 550 ia->ia_subnetmask = IN_CLASSA_NET; 551 else if (IN_CLASSB(i)) 552 ia->ia_subnetmask = IN_CLASSB_NET; 553 else 554 ia->ia_subnetmask = IN_CLASSC_NET; 555 ia->ia_sockmask.sin_addr.s_addr = htonl(ia->ia_subnetmask); 556 } 557 ia->ia_subnet = ntohl(addr->sin_addr.s_addr) & ia->ia_subnetmask; 558 in_socktrim(&ia->ia_sockmask); 559 560 if (ifp->if_flags & IFF_BROADCAST) { 561 if (broadaddr->sin_len != 0) { 562 ia->ia_broadaddr = *broadaddr; 563 } else if (ia->ia_subnetmask == IN_RFC3021_MASK) { 564 ia->ia_broadaddr.sin_addr.s_addr = INADDR_BROADCAST; 565 ia->ia_broadaddr.sin_len = sizeof(struct sockaddr_in); 566 ia->ia_broadaddr.sin_family = AF_INET; 567 } else { 568 ia->ia_broadaddr.sin_addr.s_addr = 569 htonl(ia->ia_subnet | ~ia->ia_subnetmask); 570 ia->ia_broadaddr.sin_len = sizeof(struct sockaddr_in); 571 ia->ia_broadaddr.sin_family = AF_INET; 572 } 573 } 574 575 if (ifp->if_flags & IFF_POINTOPOINT) 576 ia->ia_dstaddr = *dstaddr; 577 578 if (vhid != 0) { 579 error = (*carp_attach_p)(&ia->ia_ifa, vhid); 580 if (error) 581 return (error); 582 } 583 584 /* if_addrhead is already referenced by ifa_alloc() */ 585 IF_ADDR_WLOCK(ifp); 586 CK_STAILQ_INSERT_TAIL(&ifp->if_addrhead, ifa, ifa_link); 587 IF_ADDR_WUNLOCK(ifp); 588 589 ifa_ref(ifa); /* in_ifaddrhead */ 590 sx_assert(&in_control_sx, SA_XLOCKED); 591 CK_STAILQ_INSERT_TAIL(&V_in_ifaddrhead, ia, ia_link); 592 CK_LIST_INSERT_HEAD(INADDR_HASH(ia->ia_addr.sin_addr.s_addr), ia, 593 ia_hash); 594 595 /* 596 * Give the interface a chance to initialize 597 * if this is its first address, 598 * and to validate the address if necessary. 599 */ 600 if (ifp->if_ioctl != NULL) { 601 error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia); 602 if (error) 603 goto fail1; 604 } 605 606 /* 607 * Add route for the network. 608 */ 609 if (vhid == 0) { 610 error = in_addprefix(ia); 611 if (error) 612 goto fail1; 613 } 614 615 /* 616 * Add a loopback route to self. 617 */ 618 if (vhid == 0 && ia_need_loopback_route(ia)) { 619 struct in_ifaddr *eia; 620 621 eia = in_localip_more(ia); 622 623 if (eia == NULL) { 624 error = ifa_add_loopback_route((struct ifaddr *)ia, 625 (struct sockaddr *)&ia->ia_addr); 626 if (error) 627 goto fail2; 628 } else 629 ifa_free(&eia->ia_ifa); 630 } 631 632 if (iaIsFirst && (ifp->if_flags & IFF_MULTICAST)) { 633 struct in_addr allhosts_addr; 634 struct in_ifinfo *ii; 635 636 ii = ((struct in_ifinfo *)ifp->if_afdata[AF_INET]); 637 allhosts_addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP); 638 639 error = in_joingroup(ifp, &allhosts_addr, NULL, 640 &ii->ii_allhosts); 641 } 642 643 /* 644 * Note: we don't need extra reference for ifa, since we called 645 * with sx lock held, and ifaddr can not be deleted in concurrent 646 * thread. 647 */ 648 EVENTHANDLER_INVOKE(ifaddr_event_ext, ifp, ifa, IFADDR_EVENT_ADD); 649 650 return (error); 651 652 fail2: 653 if (vhid == 0) 654 (void )in_scrubprefix(ia, LLE_STATIC); 655 656 fail1: 657 if (ia->ia_ifa.ifa_carp) 658 (*carp_detach_p)(&ia->ia_ifa, false); 659 660 IF_ADDR_WLOCK(ifp); 661 CK_STAILQ_REMOVE(&ifp->if_addrhead, &ia->ia_ifa, ifaddr, ifa_link); 662 IF_ADDR_WUNLOCK(ifp); 663 ifa_free(&ia->ia_ifa); /* if_addrhead */ 664 665 sx_assert(&in_control_sx, SA_XLOCKED); 666 CK_STAILQ_REMOVE(&V_in_ifaddrhead, ia, in_ifaddr, ia_link); 667 CK_LIST_REMOVE(ia, ia_hash); 668 ifa_free(&ia->ia_ifa); /* in_ifaddrhead */ 669 670 return (error); 671 } 672 673 static int 674 in_difaddr_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp, struct ucred *cred) 675 { 676 const struct ifreq *ifr = (struct ifreq *)data; 677 const struct sockaddr_in *addr = (const struct sockaddr_in *) 678 &ifr->ifr_addr; 679 struct ifaddr *ifa; 680 struct in_ifaddr *ia; 681 bool deleteAny, iaIsLast; 682 int error; 683 684 if (cred != NULL) { 685 error = priv_check_cred(cred, PRIV_NET_DELIFADDR); 686 if (error) 687 return (error); 688 } 689 690 if (addr->sin_len != sizeof(struct sockaddr_in) || 691 addr->sin_family != AF_INET) 692 deleteAny = true; 693 else 694 deleteAny = false; 695 696 iaIsLast = true; 697 ia = NULL; 698 IF_ADDR_WLOCK(ifp); 699 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 700 struct in_ifaddr *it; 701 702 if (ifa->ifa_addr->sa_family != AF_INET) 703 continue; 704 705 it = (struct in_ifaddr *)ifa; 706 if (deleteAny && ia == NULL && (cred == NULL || 707 prison_check_ip4(cred, &it->ia_addr.sin_addr) == 0)) 708 ia = it; 709 710 if (it->ia_addr.sin_addr.s_addr == addr->sin_addr.s_addr && 711 (cred == NULL || prison_check_ip4(cred, 712 &addr->sin_addr) == 0)) 713 ia = it; 714 715 if (it != ia) 716 iaIsLast = false; 717 } 718 719 if (ia == NULL) { 720 IF_ADDR_WUNLOCK(ifp); 721 return (EADDRNOTAVAIL); 722 } 723 724 CK_STAILQ_REMOVE(&ifp->if_addrhead, &ia->ia_ifa, ifaddr, ifa_link); 725 IF_ADDR_WUNLOCK(ifp); 726 ifa_free(&ia->ia_ifa); /* if_addrhead */ 727 728 sx_assert(&in_control_sx, SA_XLOCKED); 729 CK_STAILQ_REMOVE(&V_in_ifaddrhead, ia, in_ifaddr, ia_link); 730 CK_LIST_REMOVE(ia, ia_hash); 731 732 /* 733 * in_scrubprefix() kills the interface route. 734 */ 735 in_scrubprefix(ia, LLE_STATIC); 736 737 /* 738 * in_ifadown gets rid of all the rest of 739 * the routes. This is not quite the right 740 * thing to do, but at least if we are running 741 * a routing process they will come back. 742 */ 743 in_ifadown(&ia->ia_ifa, 1); 744 745 if (ia->ia_ifa.ifa_carp) 746 (*carp_detach_p)(&ia->ia_ifa, cmd == SIOCAIFADDR); 747 748 /* 749 * If this is the last IPv4 address configured on this 750 * interface, leave the all-hosts group. 751 * No state-change report need be transmitted. 752 */ 753 if (iaIsLast && (ifp->if_flags & IFF_MULTICAST)) { 754 struct in_ifinfo *ii; 755 756 ii = ((struct in_ifinfo *)ifp->if_afdata[AF_INET]); 757 if (ii->ii_allhosts) { 758 (void)in_leavegroup(ii->ii_allhosts, NULL); 759 ii->ii_allhosts = NULL; 760 } 761 } 762 763 IF_ADDR_WLOCK(ifp); 764 if (callout_stop(&ia->ia_garp_timer) == 1) { 765 ifa_free(&ia->ia_ifa); 766 } 767 IF_ADDR_WUNLOCK(ifp); 768 769 EVENTHANDLER_INVOKE(ifaddr_event_ext, ifp, &ia->ia_ifa, 770 IFADDR_EVENT_DEL); 771 ifa_free(&ia->ia_ifa); /* in_ifaddrhead */ 772 773 return (0); 774 } 775 776 static int 777 in_gifaddr_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp, struct ucred *cred) 778 { 779 struct in_aliasreq *ifra = (struct in_aliasreq *)data; 780 const struct sockaddr_in *addr = &ifra->ifra_addr; 781 struct epoch_tracker et; 782 struct ifaddr *ifa; 783 struct in_ifaddr *ia; 784 785 /* 786 * ifra_addr must be present and be of INET family. 787 */ 788 if (addr->sin_len != sizeof(struct sockaddr_in) || 789 addr->sin_family != AF_INET) 790 return (EINVAL); 791 792 /* 793 * See whether address exist. 794 */ 795 ia = NULL; 796 NET_EPOCH_ENTER(et); 797 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 798 struct in_ifaddr *it; 799 800 if (ifa->ifa_addr->sa_family != AF_INET) 801 continue; 802 803 it = (struct in_ifaddr *)ifa; 804 if (it->ia_addr.sin_addr.s_addr == addr->sin_addr.s_addr && 805 prison_check_ip4(cred, &addr->sin_addr) == 0) { 806 ia = it; 807 break; 808 } 809 } 810 if (ia == NULL) { 811 NET_EPOCH_EXIT(et); 812 return (EADDRNOTAVAIL); 813 } 814 815 ifra->ifra_mask = ia->ia_sockmask; 816 if ((ifp->if_flags & IFF_POINTOPOINT) && 817 ia->ia_dstaddr.sin_family == AF_INET) 818 ifra->ifra_dstaddr = ia->ia_dstaddr; 819 else if ((ifp->if_flags & IFF_BROADCAST) && 820 ia->ia_broadaddr.sin_family == AF_INET) 821 ifra->ifra_broadaddr = ia->ia_broadaddr; 822 else 823 memset(&ifra->ifra_broadaddr, 0, 824 sizeof(ifra->ifra_broadaddr)); 825 826 NET_EPOCH_EXIT(et); 827 return (0); 828 } 829 830 static int 831 in_match_ifaddr(const struct rtentry *rt, const struct nhop_object *nh, void *arg) 832 { 833 834 if (nh->nh_ifa == (struct ifaddr *)arg) 835 return (1); 836 837 return (0); 838 } 839 840 static int 841 in_handle_prefix_route(uint32_t fibnum, int cmd, 842 struct sockaddr_in *dst, struct sockaddr_in *netmask, struct ifaddr *ifa, 843 struct ifnet *ifp) 844 { 845 846 NET_EPOCH_ASSERT(); 847 848 /* Prepare gateway */ 849 struct sockaddr_dl_short sdl = { 850 .sdl_family = AF_LINK, 851 .sdl_len = sizeof(struct sockaddr_dl_short), 852 .sdl_type = ifa->ifa_ifp->if_type, 853 .sdl_index = ifa->ifa_ifp->if_index, 854 }; 855 856 struct rt_addrinfo info = { 857 .rti_ifa = ifa, 858 .rti_ifp = ifp, 859 .rti_flags = RTF_PINNED | ((netmask != NULL) ? 0 : RTF_HOST), 860 .rti_info = { 861 [RTAX_DST] = (struct sockaddr *)dst, 862 [RTAX_NETMASK] = (struct sockaddr *)netmask, 863 [RTAX_GATEWAY] = (struct sockaddr *)&sdl, 864 }, 865 /* Ensure we delete the prefix IFF prefix ifa matches */ 866 .rti_filter = in_match_ifaddr, 867 .rti_filterdata = ifa, 868 }; 869 870 return (rib_handle_ifaddr_info(fibnum, cmd, &info)); 871 } 872 873 /* 874 * Routing table interaction with interface addresses. 875 * 876 * In general, two types of routes needs to be installed: 877 * a) "interface" or "prefix" route, telling user that the addresses 878 * behind the ifa prefix are reached directly. 879 * b) "loopback" route installed for the ifa address, telling user that 880 * the address belongs to local system. 881 * 882 * Handling for (a) and (b) differs in multi-fib aspects, hence they 883 * are implemented in different functions below. 884 * 885 * The cases above may intersect - /32 interface aliases results in 886 * the same prefix produced by (a) and (b). This blurs the definition 887 * of the "loopback" route and complicate interactions. The interaction 888 * table is defined below. The case numbers are used in the multiple 889 * functions below to refer to the particular test case. 890 * 891 * There can be multiple options: 892 * 1) Adding address with prefix on non-p2p/non-loopback interface. 893 * Example: 192.0.2.1/24. Action: 894 * * add "prefix" route towards 192.0.2.0/24 via @ia interface, 895 * using @ia as an address source. 896 * * add "loopback" route towards 192.0.2.1 via V_loif, saving 897 * @ia ifp in the gateway and using @ia as an address source. 898 * 899 * 2) Adding address with /32 mask to non-p2p/non-loopback interface. 900 * Example: 192.0.2.2/32. Action: 901 * * add "prefix" host route via V_loif, using @ia as an address source. 902 * 903 * 3) Adding address with or without prefix to p2p interface. 904 * Example: 10.0.0.1/24->10.0.0.2. Action: 905 * * add "prefix" host route towards 10.0.0.2 via this interface, using @ia 906 * as an address source. Note: no sense in installing full /24 as the interface 907 * is point-to-point. 908 * * add "loopback" route towards 10.0.9.1 via V_loif, saving 909 * @ia ifp in the gateway and using @ia as an address source. 910 * 911 * 4) Adding address with or without prefix to loopback interface. 912 * Example: 192.0.2.1/24. Action: 913 * * add "prefix" host route via @ia interface, using @ia as an address source. 914 * Note: Skip installing /24 prefix as it would introduce TTL loop 915 * for the traffic destined to these addresses. 916 */ 917 918 /* 919 * Checks if @ia needs to install loopback route to @ia address via 920 * ifa_maintain_loopback_route(). 921 * 922 * Return true on success. 923 */ 924 static bool 925 ia_need_loopback_route(const struct in_ifaddr *ia) 926 { 927 struct ifnet *ifp = ia->ia_ifp; 928 929 /* Case 4: Skip loopback interfaces */ 930 if ((ifp->if_flags & IFF_LOOPBACK) || 931 (ia->ia_addr.sin_addr.s_addr == INADDR_ANY)) 932 return (false); 933 934 /* Clash avoidance: Skip p2p interfaces with both addresses are equal */ 935 if ((ifp->if_flags & IFF_POINTOPOINT) && 936 ia->ia_dstaddr.sin_addr.s_addr == ia->ia_addr.sin_addr.s_addr) 937 return (false); 938 939 /* Case 2: skip /32 prefixes */ 940 if (!(ifp->if_flags & IFF_POINTOPOINT) && 941 (ia->ia_sockmask.sin_addr.s_addr == INADDR_BROADCAST)) 942 return (false); 943 944 return (true); 945 } 946 947 /* 948 * Calculate "prefix" route corresponding to @ia. 949 */ 950 static void 951 ia_getrtprefix(const struct in_ifaddr *ia, struct in_addr *prefix, struct in_addr *mask) 952 { 953 954 if (ia->ia_ifp->if_flags & IFF_POINTOPOINT) { 955 /* Case 3: return host route for dstaddr */ 956 *prefix = ia->ia_dstaddr.sin_addr; 957 mask->s_addr = INADDR_BROADCAST; 958 } else if (ia->ia_ifp->if_flags & IFF_LOOPBACK) { 959 /* Case 4: return host route for ifaddr */ 960 *prefix = ia->ia_addr.sin_addr; 961 mask->s_addr = INADDR_BROADCAST; 962 } else { 963 /* Cases 1,2: return actual ia prefix */ 964 *prefix = ia->ia_addr.sin_addr; 965 *mask = ia->ia_sockmask.sin_addr; 966 prefix->s_addr &= mask->s_addr; 967 } 968 } 969 970 /* 971 * Adds or delete interface "prefix" route corresponding to @ifa. 972 * Returns 0 on success or errno. 973 */ 974 static int 975 in_handle_ifaddr_route(int cmd, struct in_ifaddr *ia) 976 { 977 struct ifaddr *ifa = &ia->ia_ifa; 978 struct in_addr daddr, maddr; 979 struct sockaddr_in *pmask; 980 struct epoch_tracker et; 981 int error; 982 983 ia_getrtprefix(ia, &daddr, &maddr); 984 985 struct sockaddr_in mask = { 986 .sin_family = AF_INET, 987 .sin_len = sizeof(struct sockaddr_in), 988 .sin_addr = maddr, 989 }; 990 991 pmask = (maddr.s_addr != INADDR_BROADCAST) ? &mask : NULL; 992 993 struct sockaddr_in dst = { 994 .sin_family = AF_INET, 995 .sin_len = sizeof(struct sockaddr_in), 996 .sin_addr.s_addr = daddr.s_addr & maddr.s_addr, 997 }; 998 999 struct ifnet *ifp = ia->ia_ifp; 1000 1001 if ((maddr.s_addr == INADDR_BROADCAST) && 1002 (!(ia->ia_ifp->if_flags & (IFF_POINTOPOINT|IFF_LOOPBACK)))) { 1003 /* Case 2: host route on broadcast interface */ 1004 ifp = V_loif; 1005 } 1006 1007 uint32_t fibnum = ifa->ifa_ifp->if_fib; 1008 NET_EPOCH_ENTER(et); 1009 error = in_handle_prefix_route(fibnum, cmd, &dst, pmask, ifa, ifp); 1010 NET_EPOCH_EXIT(et); 1011 1012 return (error); 1013 } 1014 1015 /* 1016 * Check if we have a route for the given prefix already. 1017 */ 1018 static bool 1019 in_hasrtprefix(struct in_ifaddr *target) 1020 { 1021 struct epoch_tracker et; 1022 struct in_ifaddr *ia; 1023 struct in_addr prefix, mask, p, m; 1024 bool result = false; 1025 1026 ia_getrtprefix(target, &prefix, &mask); 1027 1028 /* Look for an existing address with the same prefix, mask, and fib */ 1029 NET_EPOCH_ENTER(et); 1030 CK_STAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) { 1031 ia_getrtprefix(ia, &p, &m); 1032 1033 if (prefix.s_addr != p.s_addr || 1034 mask.s_addr != m.s_addr) 1035 continue; 1036 1037 if (target->ia_ifp->if_fib != ia->ia_ifp->if_fib) 1038 continue; 1039 1040 /* 1041 * If we got a matching prefix route inserted by other 1042 * interface address, we are done here. 1043 */ 1044 if (ia->ia_flags & IFA_ROUTE) { 1045 result = true; 1046 break; 1047 } 1048 } 1049 NET_EPOCH_EXIT(et); 1050 1051 return (result); 1052 } 1053 1054 int 1055 in_addprefix(struct in_ifaddr *target) 1056 { 1057 int error; 1058 1059 if (in_hasrtprefix(target)) { 1060 if (V_nosameprefix) 1061 return (EEXIST); 1062 else { 1063 rt_addrmsg(RTM_ADD, &target->ia_ifa, 1064 target->ia_ifp->if_fib); 1065 return (0); 1066 } 1067 } 1068 1069 /* 1070 * No-one seem to have this prefix route, so we try to insert it. 1071 */ 1072 rt_addrmsg(RTM_ADD, &target->ia_ifa, target->ia_ifp->if_fib); 1073 error = in_handle_ifaddr_route(RTM_ADD, target); 1074 if (!error) 1075 target->ia_flags |= IFA_ROUTE; 1076 return (error); 1077 } 1078 1079 /* 1080 * Removes either all lle entries for given @ia, or lle 1081 * corresponding to @ia address. 1082 */ 1083 static void 1084 in_scrubprefixlle(struct in_ifaddr *ia, int all, u_int flags) 1085 { 1086 struct sockaddr_in addr, mask; 1087 struct sockaddr *saddr, *smask; 1088 struct ifnet *ifp; 1089 1090 saddr = (struct sockaddr *)&addr; 1091 bzero(&addr, sizeof(addr)); 1092 addr.sin_len = sizeof(addr); 1093 addr.sin_family = AF_INET; 1094 smask = (struct sockaddr *)&mask; 1095 bzero(&mask, sizeof(mask)); 1096 mask.sin_len = sizeof(mask); 1097 mask.sin_family = AF_INET; 1098 mask.sin_addr.s_addr = ia->ia_subnetmask; 1099 ifp = ia->ia_ifp; 1100 1101 if (all) { 1102 /* 1103 * Remove all L2 entries matching given prefix. 1104 * Convert address to host representation to avoid 1105 * doing this on every callback. ia_subnetmask is already 1106 * stored in host representation. 1107 */ 1108 addr.sin_addr.s_addr = ntohl(ia->ia_addr.sin_addr.s_addr); 1109 lltable_prefix_free(AF_INET, saddr, smask, flags); 1110 } else { 1111 /* Remove interface address only */ 1112 addr.sin_addr.s_addr = ia->ia_addr.sin_addr.s_addr; 1113 lltable_delete_addr(LLTABLE(ifp), LLE_IFADDR, saddr); 1114 } 1115 } 1116 1117 /* 1118 * If there is no other address in the system that can serve a route to the 1119 * same prefix, remove the route. Hand over the route to the new address 1120 * otherwise. 1121 */ 1122 int 1123 in_scrubprefix(struct in_ifaddr *target, u_int flags) 1124 { 1125 struct epoch_tracker et; 1126 struct in_ifaddr *ia; 1127 struct in_addr prefix, mask, p, m; 1128 int error = 0; 1129 1130 /* 1131 * Remove the loopback route to the interface address. 1132 */ 1133 if (ia_need_loopback_route(target) && (flags & LLE_STATIC)) { 1134 struct in_ifaddr *eia; 1135 1136 eia = in_localip_more(target); 1137 1138 if (eia != NULL) { 1139 error = ifa_switch_loopback_route((struct ifaddr *)eia, 1140 (struct sockaddr *)&target->ia_addr); 1141 ifa_free(&eia->ia_ifa); 1142 } else { 1143 error = ifa_del_loopback_route((struct ifaddr *)target, 1144 (struct sockaddr *)&target->ia_addr); 1145 } 1146 } 1147 1148 ia_getrtprefix(target, &prefix, &mask); 1149 1150 if ((target->ia_flags & IFA_ROUTE) == 0) { 1151 rt_addrmsg(RTM_DELETE, &target->ia_ifa, target->ia_ifp->if_fib); 1152 1153 /* 1154 * Removing address from !IFF_UP interface or 1155 * prefix which exists on other interface (along with route). 1156 * No entries should exist here except target addr. 1157 * Given that, delete this entry only. 1158 */ 1159 in_scrubprefixlle(target, 0, flags); 1160 return (0); 1161 } 1162 1163 NET_EPOCH_ENTER(et); 1164 CK_STAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) { 1165 ia_getrtprefix(ia, &p, &m); 1166 1167 if (prefix.s_addr != p.s_addr || 1168 mask.s_addr != m.s_addr) 1169 continue; 1170 1171 if ((ia->ia_ifp->if_flags & IFF_UP) == 0) 1172 continue; 1173 1174 /* 1175 * If we got a matching prefix address, move IFA_ROUTE and 1176 * the route itself to it. Make sure that routing daemons 1177 * get a heads-up. 1178 */ 1179 if ((ia->ia_flags & IFA_ROUTE) == 0) { 1180 ifa_ref(&ia->ia_ifa); 1181 NET_EPOCH_EXIT(et); 1182 error = in_handle_ifaddr_route(RTM_DELETE, target); 1183 if (error == 0) 1184 target->ia_flags &= ~IFA_ROUTE; 1185 else 1186 log(LOG_INFO, "in_scrubprefix: err=%d, old prefix delete failed\n", 1187 error); 1188 /* Scrub all entries IFF interface is different */ 1189 in_scrubprefixlle(target, target->ia_ifp != ia->ia_ifp, 1190 flags); 1191 error = in_handle_ifaddr_route(RTM_ADD, ia); 1192 if (error == 0) 1193 ia->ia_flags |= IFA_ROUTE; 1194 else 1195 log(LOG_INFO, "in_scrubprefix: err=%d, new prefix add failed\n", 1196 error); 1197 ifa_free(&ia->ia_ifa); 1198 return (error); 1199 } 1200 } 1201 NET_EPOCH_EXIT(et); 1202 1203 /* 1204 * remove all L2 entries on the given prefix 1205 */ 1206 in_scrubprefixlle(target, 1, flags); 1207 1208 /* 1209 * As no-one seem to have this prefix, we can remove the route. 1210 */ 1211 rt_addrmsg(RTM_DELETE, &target->ia_ifa, target->ia_ifp->if_fib); 1212 error = in_handle_ifaddr_route(RTM_DELETE, target); 1213 if (error == 0) 1214 target->ia_flags &= ~IFA_ROUTE; 1215 else 1216 log(LOG_INFO, "in_scrubprefix: err=%d, prefix delete failed\n", error); 1217 return (error); 1218 } 1219 1220 void 1221 in_ifscrub_all(void) 1222 { 1223 struct ifnet *ifp; 1224 struct ifaddr *ifa, *nifa; 1225 struct ifaliasreq ifr; 1226 1227 IFNET_RLOCK(); 1228 CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) { 1229 /* Cannot lock here - lock recursion. */ 1230 /* NET_EPOCH_ENTER(et); */ 1231 CK_STAILQ_FOREACH_SAFE(ifa, &ifp->if_addrhead, ifa_link, nifa) { 1232 if (ifa->ifa_addr->sa_family != AF_INET) 1233 continue; 1234 1235 /* 1236 * This is ugly but the only way for legacy IP to 1237 * cleanly remove addresses and everything attached. 1238 */ 1239 bzero(&ifr, sizeof(ifr)); 1240 ifr.ifra_addr = *ifa->ifa_addr; 1241 if (ifa->ifa_dstaddr) 1242 ifr.ifra_broadaddr = *ifa->ifa_dstaddr; 1243 (void)in_control(NULL, SIOCDIFADDR, (caddr_t)&ifr, 1244 ifp, NULL); 1245 } 1246 /* NET_EPOCH_EXIT(et); */ 1247 in_purgemaddrs(ifp); 1248 igmp_domifdetach(ifp); 1249 } 1250 IFNET_RUNLOCK(); 1251 } 1252 1253 int 1254 in_ifaddr_broadcast(struct in_addr in, struct in_ifaddr *ia) 1255 { 1256 1257 return ((in.s_addr == ia->ia_broadaddr.sin_addr.s_addr || 1258 /* 1259 * Optionally check for old-style (host 0) broadcast, but 1260 * taking into account that RFC 3021 obsoletes it. 1261 */ 1262 (V_broadcast_lowest && ia->ia_subnetmask != IN_RFC3021_MASK && 1263 ntohl(in.s_addr) == ia->ia_subnet)) && 1264 /* 1265 * Check for an all one subnetmask. These 1266 * only exist when an interface gets a secondary 1267 * address. 1268 */ 1269 ia->ia_subnetmask != (u_long)0xffffffff); 1270 } 1271 1272 /* 1273 * Return 1 if the address might be a local broadcast address. 1274 */ 1275 int 1276 in_broadcast(struct in_addr in, struct ifnet *ifp) 1277 { 1278 struct ifaddr *ifa; 1279 int found; 1280 1281 NET_EPOCH_ASSERT(); 1282 1283 if (in.s_addr == INADDR_BROADCAST || 1284 in.s_addr == INADDR_ANY) 1285 return (1); 1286 if ((ifp->if_flags & IFF_BROADCAST) == 0) 1287 return (0); 1288 found = 0; 1289 /* 1290 * Look through the list of addresses for a match 1291 * with a broadcast address. 1292 */ 1293 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) 1294 if (ifa->ifa_addr->sa_family == AF_INET && 1295 in_ifaddr_broadcast(in, (struct in_ifaddr *)ifa)) { 1296 found = 1; 1297 break; 1298 } 1299 return (found); 1300 } 1301 1302 /* 1303 * On interface removal, clean up IPv4 data structures hung off of the ifnet. 1304 */ 1305 void 1306 in_ifdetach(struct ifnet *ifp) 1307 { 1308 IN_MULTI_LOCK(); 1309 in_pcbpurgeif0(&V_ripcbinfo, ifp); 1310 in_pcbpurgeif0(&V_udbinfo, ifp); 1311 in_pcbpurgeif0(&V_ulitecbinfo, ifp); 1312 in_purgemaddrs(ifp); 1313 IN_MULTI_UNLOCK(); 1314 1315 /* 1316 * Make sure all multicast deletions invoking if_ioctl() are 1317 * completed before returning. Else we risk accessing a freed 1318 * ifnet structure pointer. 1319 */ 1320 inm_release_wait(NULL); 1321 } 1322 1323 static void 1324 in_ifnet_event(void *arg __unused, struct ifnet *ifp, int event) 1325 { 1326 struct epoch_tracker et; 1327 struct ifaddr *ifa; 1328 struct in_ifaddr *ia; 1329 int error; 1330 1331 NET_EPOCH_ENTER(et); 1332 switch (event) { 1333 case IFNET_EVENT_DOWN: 1334 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1335 if (ifa->ifa_addr->sa_family != AF_INET) 1336 continue; 1337 ia = (struct in_ifaddr *)ifa; 1338 if ((ia->ia_flags & IFA_ROUTE) == 0) 1339 continue; 1340 ifa_ref(ifa); 1341 /* 1342 * in_scrubprefix() kills the interface route. 1343 */ 1344 in_scrubprefix(ia, 0); 1345 /* 1346 * in_ifadown gets rid of all the rest of the 1347 * routes. This is not quite the right thing 1348 * to do, but at least if we are running a 1349 * routing process they will come back. 1350 */ 1351 in_ifadown(ifa, 0); 1352 ifa_free(ifa); 1353 } 1354 break; 1355 1356 case IFNET_EVENT_UP: 1357 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 1358 if (ifa->ifa_addr->sa_family != AF_INET) 1359 continue; 1360 ia = (struct in_ifaddr *)ifa; 1361 if (ia->ia_flags & IFA_ROUTE) 1362 continue; 1363 ifa_ref(ifa); 1364 error = ifa_del_loopback_route(ifa, ifa->ifa_addr); 1365 rt_addrmsg(RTM_ADD, ifa, ifa->ifa_ifp->if_fib); 1366 error = in_handle_ifaddr_route(RTM_ADD, ia); 1367 if (error == 0) 1368 ia->ia_flags |= IFA_ROUTE; 1369 error = ifa_add_loopback_route(ifa, ifa->ifa_addr); 1370 ifa_free(ifa); 1371 } 1372 break; 1373 } 1374 NET_EPOCH_EXIT(et); 1375 } 1376 EVENTHANDLER_DEFINE(ifnet_event, in_ifnet_event, NULL, EVENTHANDLER_PRI_ANY); 1377 1378 /* 1379 * Delete all IPv4 multicast address records, and associated link-layer 1380 * multicast address records, associated with ifp. 1381 * XXX It looks like domifdetach runs AFTER the link layer cleanup. 1382 * XXX This should not race with ifma_protospec being set during 1383 * a new allocation, if it does, we have bigger problems. 1384 */ 1385 static void 1386 in_purgemaddrs(struct ifnet *ifp) 1387 { 1388 struct epoch_tracker et; 1389 struct in_multi_head purgeinms; 1390 struct in_multi *inm; 1391 struct ifmultiaddr *ifma; 1392 1393 SLIST_INIT(&purgeinms); 1394 IN_MULTI_LIST_LOCK(); 1395 1396 /* 1397 * Extract list of in_multi associated with the detaching ifp 1398 * which the PF_INET layer is about to release. 1399 * We need to do this as IF_ADDR_LOCK() may be re-acquired 1400 * by code further down. 1401 */ 1402 IF_ADDR_WLOCK(ifp); 1403 NET_EPOCH_ENTER(et); 1404 CK_STAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) { 1405 inm = inm_ifmultiaddr_get_inm(ifma); 1406 if (inm == NULL) 1407 continue; 1408 inm_rele_locked(&purgeinms, inm); 1409 } 1410 NET_EPOCH_EXIT(et); 1411 IF_ADDR_WUNLOCK(ifp); 1412 1413 inm_release_list_deferred(&purgeinms); 1414 igmp_ifdetach(ifp); 1415 IN_MULTI_LIST_UNLOCK(); 1416 } 1417 1418 struct in_llentry { 1419 struct llentry base; 1420 }; 1421 1422 #define IN_LLTBL_DEFAULT_HSIZE 32 1423 #define IN_LLTBL_HASH(k, h) \ 1424 (((((((k >> 8) ^ k) >> 8) ^ k) >> 8) ^ k) & ((h) - 1)) 1425 1426 /* 1427 * Do actual deallocation of @lle. 1428 */ 1429 static void 1430 in_lltable_destroy_lle_unlocked(epoch_context_t ctx) 1431 { 1432 struct llentry *lle; 1433 1434 lle = __containerof(ctx, struct llentry, lle_epoch_ctx); 1435 LLE_LOCK_DESTROY(lle); 1436 LLE_REQ_DESTROY(lle); 1437 free(lle, M_LLTABLE); 1438 } 1439 1440 /* 1441 * Called by LLE_FREE_LOCKED when number of references 1442 * drops to zero. 1443 */ 1444 static void 1445 in_lltable_destroy_lle(struct llentry *lle) 1446 { 1447 1448 LLE_WUNLOCK(lle); 1449 NET_EPOCH_CALL(in_lltable_destroy_lle_unlocked, &lle->lle_epoch_ctx); 1450 } 1451 1452 static struct llentry * 1453 in_lltable_new(struct in_addr addr4, u_int flags) 1454 { 1455 struct in_llentry *lle; 1456 1457 lle = malloc(sizeof(struct in_llentry), M_LLTABLE, M_NOWAIT | M_ZERO); 1458 if (lle == NULL) /* NB: caller generates msg */ 1459 return NULL; 1460 1461 /* 1462 * For IPv4 this will trigger "arpresolve" to generate 1463 * an ARP request. 1464 */ 1465 lle->base.la_expire = time_uptime; /* mark expired */ 1466 lle->base.r_l3addr.addr4 = addr4; 1467 lle->base.lle_refcnt = 1; 1468 lle->base.lle_free = in_lltable_destroy_lle; 1469 LLE_LOCK_INIT(&lle->base); 1470 LLE_REQ_INIT(&lle->base); 1471 callout_init(&lle->base.lle_timer, 1); 1472 1473 return (&lle->base); 1474 } 1475 1476 #define IN_ARE_MASKED_ADDR_EQUAL(d, a, m) ( \ 1477 ((((d).s_addr ^ (a).s_addr) & (m).s_addr)) == 0 ) 1478 1479 static int 1480 in_lltable_match_prefix(const struct sockaddr *saddr, 1481 const struct sockaddr *smask, u_int flags, struct llentry *lle) 1482 { 1483 struct in_addr addr, mask, lle_addr; 1484 1485 addr = ((const struct sockaddr_in *)saddr)->sin_addr; 1486 mask = ((const struct sockaddr_in *)smask)->sin_addr; 1487 lle_addr.s_addr = ntohl(lle->r_l3addr.addr4.s_addr); 1488 1489 if (IN_ARE_MASKED_ADDR_EQUAL(lle_addr, addr, mask) == 0) 1490 return (0); 1491 1492 if (lle->la_flags & LLE_IFADDR) { 1493 /* 1494 * Delete LLE_IFADDR records IFF address & flag matches. 1495 * Note that addr is the interface address within prefix 1496 * being matched. 1497 * Note also we should handle 'ifdown' cases without removing 1498 * ifaddr macs. 1499 */ 1500 if (addr.s_addr == lle_addr.s_addr && (flags & LLE_STATIC) != 0) 1501 return (1); 1502 return (0); 1503 } 1504 1505 /* flags & LLE_STATIC means deleting both dynamic and static entries */ 1506 if ((flags & LLE_STATIC) || !(lle->la_flags & LLE_STATIC)) 1507 return (1); 1508 1509 return (0); 1510 } 1511 1512 static void 1513 in_lltable_free_entry(struct lltable *llt, struct llentry *lle) 1514 { 1515 size_t pkts_dropped; 1516 1517 LLE_WLOCK_ASSERT(lle); 1518 KASSERT(llt != NULL, ("lltable is NULL")); 1519 1520 /* Unlink entry from table if not already */ 1521 if ((lle->la_flags & LLE_LINKED) != 0) { 1522 IF_AFDATA_WLOCK_ASSERT(llt->llt_ifp); 1523 lltable_unlink_entry(llt, lle); 1524 } 1525 1526 /* Drop hold queue */ 1527 pkts_dropped = llentry_free(lle); 1528 ARPSTAT_ADD(dropped, pkts_dropped); 1529 } 1530 1531 static int 1532 in_lltable_rtcheck(struct ifnet *ifp, u_int flags, const struct sockaddr *l3addr) 1533 { 1534 struct nhop_object *nh; 1535 struct in_addr addr; 1536 1537 KASSERT(l3addr->sa_family == AF_INET, 1538 ("sin_family %d", l3addr->sa_family)); 1539 1540 addr = ((const struct sockaddr_in *)l3addr)->sin_addr; 1541 1542 nh = fib4_lookup(ifp->if_fib, addr, 0, NHR_NONE, 0); 1543 if (nh == NULL) 1544 return (EINVAL); 1545 1546 /* 1547 * If the gateway for an existing host route matches the target L3 1548 * address, which is a special route inserted by some implementation 1549 * such as MANET, and the interface is of the correct type, then 1550 * allow for ARP to proceed. 1551 */ 1552 if (nh->nh_flags & NHF_GATEWAY) { 1553 if (!(nh->nh_flags & NHF_HOST) || nh->nh_ifp->if_type != IFT_ETHER || 1554 (nh->nh_ifp->if_flags & (IFF_NOARP | IFF_STATICARP)) != 0 || 1555 memcmp(nh->gw_sa.sa_data, l3addr->sa_data, 1556 sizeof(in_addr_t)) != 0) { 1557 return (EINVAL); 1558 } 1559 } 1560 1561 /* 1562 * Make sure that at least the destination address is covered 1563 * by the route. This is for handling the case where 2 or more 1564 * interfaces have the same prefix. An incoming packet arrives 1565 * on one interface and the corresponding outgoing packet leaves 1566 * another interface. 1567 */ 1568 if ((nh->nh_ifp != ifp) && (nh->nh_flags & NHF_HOST) == 0) { 1569 struct in_ifaddr *ia = (struct in_ifaddr *)ifaof_ifpforaddr(l3addr, ifp); 1570 struct in_addr dst_addr, mask_addr; 1571 1572 if (ia == NULL) 1573 return (EINVAL); 1574 1575 /* 1576 * ifaof_ifpforaddr() returns _best matching_ IFA. 1577 * It is possible that ifa prefix does not cover our address. 1578 * Explicitly verify and fail if that's the case. 1579 */ 1580 dst_addr = IA_SIN(ia)->sin_addr; 1581 mask_addr.s_addr = htonl(ia->ia_subnetmask); 1582 1583 if (!IN_ARE_MASKED_ADDR_EQUAL(dst_addr, addr, mask_addr)) 1584 return (EINVAL); 1585 } 1586 1587 return (0); 1588 } 1589 1590 static inline uint32_t 1591 in_lltable_hash_dst(const struct in_addr dst, uint32_t hsize) 1592 { 1593 1594 return (IN_LLTBL_HASH(dst.s_addr, hsize)); 1595 } 1596 1597 static uint32_t 1598 in_lltable_hash(const struct llentry *lle, uint32_t hsize) 1599 { 1600 1601 return (in_lltable_hash_dst(lle->r_l3addr.addr4, hsize)); 1602 } 1603 1604 static void 1605 in_lltable_fill_sa_entry(const struct llentry *lle, struct sockaddr *sa) 1606 { 1607 struct sockaddr_in *sin; 1608 1609 sin = (struct sockaddr_in *)sa; 1610 bzero(sin, sizeof(*sin)); 1611 sin->sin_family = AF_INET; 1612 sin->sin_len = sizeof(*sin); 1613 sin->sin_addr = lle->r_l3addr.addr4; 1614 } 1615 1616 static inline struct llentry * 1617 in_lltable_find_dst(struct lltable *llt, struct in_addr dst) 1618 { 1619 struct llentry *lle; 1620 struct llentries *lleh; 1621 u_int hashidx; 1622 1623 hashidx = in_lltable_hash_dst(dst, llt->llt_hsize); 1624 lleh = &llt->lle_head[hashidx]; 1625 CK_LIST_FOREACH(lle, lleh, lle_next) { 1626 if (lle->la_flags & LLE_DELETED) 1627 continue; 1628 if (lle->r_l3addr.addr4.s_addr == dst.s_addr) 1629 break; 1630 } 1631 1632 return (lle); 1633 } 1634 1635 static void 1636 in_lltable_delete_entry(struct lltable *llt, struct llentry *lle) 1637 { 1638 1639 lle->la_flags |= LLE_DELETED; 1640 EVENTHANDLER_INVOKE(lle_event, lle, LLENTRY_DELETED); 1641 #ifdef DIAGNOSTIC 1642 log(LOG_INFO, "ifaddr cache = %p is deleted\n", lle); 1643 #endif 1644 llentry_free(lle); 1645 } 1646 1647 static struct llentry * 1648 in_lltable_alloc(struct lltable *llt, u_int flags, const struct sockaddr *l3addr) 1649 { 1650 const struct sockaddr_in *sin = (const struct sockaddr_in *)l3addr; 1651 struct ifnet *ifp = llt->llt_ifp; 1652 struct llentry *lle; 1653 char linkhdr[LLE_MAX_LINKHDR]; 1654 size_t linkhdrsize; 1655 int lladdr_off; 1656 1657 KASSERT(l3addr->sa_family == AF_INET, 1658 ("sin_family %d", l3addr->sa_family)); 1659 1660 /* 1661 * A route that covers the given address must have 1662 * been installed 1st because we are doing a resolution, 1663 * verify this. 1664 */ 1665 if (!(flags & LLE_IFADDR) && 1666 in_lltable_rtcheck(ifp, flags, l3addr) != 0) 1667 return (NULL); 1668 1669 lle = in_lltable_new(sin->sin_addr, flags); 1670 if (lle == NULL) { 1671 log(LOG_INFO, "lla_lookup: new lle malloc failed\n"); 1672 return (NULL); 1673 } 1674 lle->la_flags = flags; 1675 if (flags & LLE_STATIC) 1676 lle->r_flags |= RLLE_VALID; 1677 if ((flags & LLE_IFADDR) == LLE_IFADDR) { 1678 linkhdrsize = LLE_MAX_LINKHDR; 1679 if (lltable_calc_llheader(ifp, AF_INET, IF_LLADDR(ifp), 1680 linkhdr, &linkhdrsize, &lladdr_off) != 0) { 1681 in_lltable_free_entry(llt, lle); 1682 return (NULL); 1683 } 1684 lltable_set_entry_addr(ifp, lle, linkhdr, linkhdrsize, 1685 lladdr_off); 1686 lle->la_flags |= LLE_STATIC; 1687 lle->r_flags |= (RLLE_VALID | RLLE_IFADDR); 1688 lle->la_expire = 0; 1689 } 1690 1691 return (lle); 1692 } 1693 1694 /* 1695 * Return NULL if not found or marked for deletion. 1696 * If found return lle read locked. 1697 */ 1698 static struct llentry * 1699 in_lltable_lookup(struct lltable *llt, u_int flags, const struct sockaddr *l3addr) 1700 { 1701 const struct sockaddr_in *sin = (const struct sockaddr_in *)l3addr; 1702 struct llentry *lle; 1703 1704 IF_AFDATA_LOCK_ASSERT(llt->llt_ifp); 1705 KASSERT(l3addr->sa_family == AF_INET, 1706 ("sin_family %d", l3addr->sa_family)); 1707 KASSERT((flags & (LLE_UNLOCKED | LLE_EXCLUSIVE)) != 1708 (LLE_UNLOCKED | LLE_EXCLUSIVE), 1709 ("wrong lle request flags: %#x", flags)); 1710 1711 lle = in_lltable_find_dst(llt, sin->sin_addr); 1712 if (lle == NULL) 1713 return (NULL); 1714 if (flags & LLE_UNLOCKED) 1715 return (lle); 1716 1717 if (flags & LLE_EXCLUSIVE) 1718 LLE_WLOCK(lle); 1719 else 1720 LLE_RLOCK(lle); 1721 1722 /* 1723 * If the afdata lock is not held, the LLE may have been unlinked while 1724 * we were blocked on the LLE lock. Check for this case. 1725 */ 1726 if (__predict_false((lle->la_flags & LLE_LINKED) == 0)) { 1727 if (flags & LLE_EXCLUSIVE) 1728 LLE_WUNLOCK(lle); 1729 else 1730 LLE_RUNLOCK(lle); 1731 return (NULL); 1732 } 1733 return (lle); 1734 } 1735 1736 static int 1737 in_lltable_dump_entry(struct lltable *llt, struct llentry *lle, 1738 struct sysctl_req *wr) 1739 { 1740 struct ifnet *ifp = llt->llt_ifp; 1741 /* XXX stack use */ 1742 struct { 1743 struct rt_msghdr rtm; 1744 struct sockaddr_in sin; 1745 struct sockaddr_dl sdl; 1746 } arpc; 1747 struct sockaddr_dl *sdl; 1748 int error; 1749 1750 bzero(&arpc, sizeof(arpc)); 1751 /* skip deleted entries */ 1752 if ((lle->la_flags & LLE_DELETED) == LLE_DELETED) 1753 return (0); 1754 /* Skip if jailed and not a valid IP of the prison. */ 1755 lltable_fill_sa_entry(lle,(struct sockaddr *)&arpc.sin); 1756 if (prison_if(wr->td->td_ucred, (struct sockaddr *)&arpc.sin) != 0) 1757 return (0); 1758 /* 1759 * produce a msg made of: 1760 * struct rt_msghdr; 1761 * struct sockaddr_in; (IPv4) 1762 * struct sockaddr_dl; 1763 */ 1764 arpc.rtm.rtm_msglen = sizeof(arpc); 1765 arpc.rtm.rtm_version = RTM_VERSION; 1766 arpc.rtm.rtm_type = RTM_GET; 1767 arpc.rtm.rtm_flags = RTF_UP; 1768 arpc.rtm.rtm_addrs = RTA_DST | RTA_GATEWAY; 1769 1770 /* publish */ 1771 if (lle->la_flags & LLE_PUB) 1772 arpc.rtm.rtm_flags |= RTF_ANNOUNCE; 1773 1774 sdl = &arpc.sdl; 1775 sdl->sdl_family = AF_LINK; 1776 sdl->sdl_len = sizeof(*sdl); 1777 sdl->sdl_index = ifp->if_index; 1778 sdl->sdl_type = ifp->if_type; 1779 if ((lle->la_flags & LLE_VALID) == LLE_VALID) { 1780 sdl->sdl_alen = ifp->if_addrlen; 1781 bcopy(lle->ll_addr, LLADDR(sdl), ifp->if_addrlen); 1782 } else { 1783 sdl->sdl_alen = 0; 1784 bzero(LLADDR(sdl), ifp->if_addrlen); 1785 } 1786 1787 arpc.rtm.rtm_rmx.rmx_expire = 1788 lle->la_flags & LLE_STATIC ? 0 : lle->la_expire; 1789 arpc.rtm.rtm_flags |= (RTF_HOST | RTF_LLDATA); 1790 if (lle->la_flags & LLE_STATIC) 1791 arpc.rtm.rtm_flags |= RTF_STATIC; 1792 if (lle->la_flags & LLE_IFADDR) 1793 arpc.rtm.rtm_flags |= RTF_PINNED; 1794 arpc.rtm.rtm_index = ifp->if_index; 1795 error = SYSCTL_OUT(wr, &arpc, sizeof(arpc)); 1796 1797 return (error); 1798 } 1799 1800 static void 1801 in_lltable_post_resolved(struct lltable *llt, struct llentry *lle) 1802 { 1803 struct ifnet *ifp = llt->llt_ifp; 1804 1805 /* gratuitous ARP */ 1806 if ((lle->la_flags & LLE_PUB) != 0) 1807 arprequest(ifp, &lle->r_l3addr.addr4, &lle->r_l3addr.addr4, 1808 lle->ll_addr); 1809 } 1810 1811 static struct lltable * 1812 in_lltattach(struct ifnet *ifp) 1813 { 1814 struct lltable *llt; 1815 1816 llt = lltable_allocate_htbl(IN_LLTBL_DEFAULT_HSIZE); 1817 llt->llt_af = AF_INET; 1818 llt->llt_ifp = ifp; 1819 1820 llt->llt_lookup = in_lltable_lookup; 1821 llt->llt_alloc_entry = in_lltable_alloc; 1822 llt->llt_delete_entry = in_lltable_delete_entry; 1823 llt->llt_dump_entry = in_lltable_dump_entry; 1824 llt->llt_hash = in_lltable_hash; 1825 llt->llt_fill_sa_entry = in_lltable_fill_sa_entry; 1826 llt->llt_free_entry = in_lltable_free_entry; 1827 llt->llt_match_prefix = in_lltable_match_prefix; 1828 llt->llt_mark_used = llentry_mark_used; 1829 llt->llt_post_resolved = in_lltable_post_resolved; 1830 lltable_link(llt); 1831 1832 return (llt); 1833 } 1834 1835 struct lltable * 1836 in_lltable_get(struct ifnet *ifp) 1837 { 1838 struct lltable *llt = NULL; 1839 1840 void *afdata_ptr = ifp->if_afdata[AF_INET]; 1841 if (afdata_ptr != NULL) 1842 llt = ((struct in_ifinfo *)afdata_ptr)->ii_llt; 1843 return (llt); 1844 } 1845 1846 void * 1847 in_domifattach(struct ifnet *ifp) 1848 { 1849 struct in_ifinfo *ii; 1850 1851 ii = malloc(sizeof(struct in_ifinfo), M_IFADDR, M_WAITOK|M_ZERO); 1852 1853 ii->ii_llt = in_lltattach(ifp); 1854 ii->ii_igmp = igmp_domifattach(ifp); 1855 1856 return (ii); 1857 } 1858 1859 void 1860 in_domifdetach(struct ifnet *ifp, void *aux) 1861 { 1862 struct in_ifinfo *ii = (struct in_ifinfo *)aux; 1863 1864 igmp_domifdetach(ifp); 1865 lltable_free(ii->ii_llt); 1866 free(ii, M_IFADDR); 1867 } 1868