1 /* $OpenBSD: in6_ifattach.c,v 1.118 2021/03/15 17:28:45 florian Exp $ */ 2 /* $KAME: in6_ifattach.c,v 1.124 2001/07/18 08:32:51 jinmei Exp $ */ 3 4 /* 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * 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 project 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 PROJECT 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 PROJECT 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 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 #include <sys/socket.h> 36 #include <sys/sockio.h> 37 #include <sys/kernel.h> 38 #include <sys/syslog.h> 39 40 #include <crypto/sha2.h> 41 42 #include <net/if.h> 43 #include <net/if_var.h> 44 #include <net/if_dl.h> 45 #include <net/if_types.h> 46 #include <net/route.h> 47 48 #include <netinet/in.h> 49 50 #include <netinet6/in6_var.h> 51 #include <netinet/ip6.h> 52 #include <netinet6/ip6_var.h> 53 #include <netinet6/in6_ifattach.h> 54 #include <netinet6/nd6.h> 55 #ifdef MROUTING 56 #include <netinet6/ip6_mroute.h> 57 #endif 58 59 void in6_get_rand_ifid(struct ifnet *, struct in6_addr *); 60 int in6_get_hw_ifid(struct ifnet *, struct in6_addr *); 61 void in6_get_ifid(struct ifnet *, struct in6_addr *); 62 int in6_ifattach_loopback(struct ifnet *); 63 64 #define EUI64_GBIT 0x01 65 #define EUI64_UBIT 0x02 66 #define EUI64_TO_IFID(in6) do {(in6)->s6_addr[8] ^= EUI64_UBIT; } while (0) 67 #define EUI64_GROUP(in6) ((in6)->s6_addr[8] & EUI64_GBIT) 68 #define EUI64_INDIVIDUAL(in6) (!EUI64_GROUP(in6)) 69 #define EUI64_LOCAL(in6) ((in6)->s6_addr[8] & EUI64_UBIT) 70 #define EUI64_UNIVERSAL(in6) (!EUI64_LOCAL(in6)) 71 72 #define IFID_LOCAL(in6) (!EUI64_LOCAL(in6)) 73 #define IFID_UNIVERSAL(in6) (!EUI64_UNIVERSAL(in6)) 74 75 /* 76 * Generate a random interface identifier. 77 * 78 * in6 - upper 64bits are preserved 79 */ 80 void 81 in6_get_rand_ifid(struct ifnet *ifp, struct in6_addr *in6) 82 { 83 arc4random_buf(&in6->s6_addr32[2], 8); 84 85 /* make sure to set "u" bit to local, and "g" bit to individual. */ 86 in6->s6_addr[8] &= ~EUI64_GBIT; /* g bit to "individual" */ 87 in6->s6_addr[8] |= EUI64_UBIT; /* u bit to "local" */ 88 89 /* convert EUI64 into IPv6 interface identifier */ 90 EUI64_TO_IFID(in6); 91 } 92 93 /* 94 * Get interface identifier for the specified interface. 95 * 96 * in6 - upper 64bits are preserved 97 */ 98 int 99 in6_get_hw_ifid(struct ifnet *ifp, struct in6_addr *in6) 100 { 101 struct sockaddr_dl *sdl; 102 char *addr; 103 size_t addrlen; 104 static u_int8_t allzero[8] = { 0, 0, 0, 0, 0, 0, 0, 0 }; 105 static u_int8_t allone[8] = 106 { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; 107 108 sdl = ifp->if_sadl; 109 if (sdl == NULL || sdl->sdl_alen == 0) 110 return -1; 111 112 addr = LLADDR(sdl); 113 addrlen = sdl->sdl_alen; 114 115 switch (ifp->if_type) { 116 case IFT_IEEE1394: 117 case IFT_IEEE80211: 118 /* IEEE1394 uses 16byte length address starting with EUI64 */ 119 if (addrlen > 8) 120 addrlen = 8; 121 break; 122 default: 123 break; 124 } 125 126 /* get EUI64 */ 127 switch (ifp->if_type) { 128 /* IEEE802/EUI64 cases - what others? */ 129 case IFT_ETHER: 130 case IFT_CARP: 131 case IFT_IEEE1394: 132 case IFT_IEEE80211: 133 /* look at IEEE802/EUI64 only */ 134 if (addrlen != 8 && addrlen != 6) 135 return -1; 136 137 /* 138 * check for invalid MAC address - on bsdi, we see it a lot 139 * since wildboar configures all-zero MAC on pccard before 140 * card insertion. 141 */ 142 if (bcmp(addr, allzero, addrlen) == 0) 143 return -1; 144 if (bcmp(addr, allone, addrlen) == 0) 145 return -1; 146 147 /* make EUI64 address */ 148 if (addrlen == 8) 149 memcpy(&in6->s6_addr[8], addr, 8); 150 else if (addrlen == 6) { 151 in6->s6_addr[8] = addr[0]; 152 in6->s6_addr[9] = addr[1]; 153 in6->s6_addr[10] = addr[2]; 154 in6->s6_addr[11] = 0xff; 155 in6->s6_addr[12] = 0xfe; 156 in6->s6_addr[13] = addr[3]; 157 in6->s6_addr[14] = addr[4]; 158 in6->s6_addr[15] = addr[5]; 159 } 160 break; 161 162 case IFT_GIF: 163 /* 164 * RFC2893 says: "SHOULD use IPv4 address as ifid source". 165 * however, IPv4 address is not very suitable as unique 166 * identifier source (can be renumbered). 167 * we don't do this. 168 */ 169 return -1; 170 171 default: 172 return -1; 173 } 174 175 /* sanity check: g bit must not indicate "group" */ 176 if (EUI64_GROUP(in6)) 177 return -1; 178 179 /* convert EUI64 into IPv6 interface identifier */ 180 EUI64_TO_IFID(in6); 181 182 /* 183 * sanity check: ifid must not be all zero, avoid conflict with 184 * subnet router anycast 185 */ 186 if ((in6->s6_addr[8] & ~(EUI64_GBIT | EUI64_UBIT)) == 0x00 && 187 bcmp(&in6->s6_addr[9], allzero, 7) == 0) { 188 return -1; 189 } 190 191 return 0; 192 } 193 194 /* 195 * Get interface identifier for the specified interface. If it is not 196 * available on ifp0, borrow interface identifier from other information 197 * sources. 198 */ 199 void 200 in6_get_ifid(struct ifnet *ifp0, struct in6_addr *in6) 201 { 202 struct ifnet *ifp; 203 204 /* first, try to get it from the interface itself */ 205 if (in6_get_hw_ifid(ifp0, in6) == 0) { 206 nd6log((LOG_DEBUG, "%s: got interface identifier from itself\n", 207 ifp0->if_xname)); 208 goto success; 209 } 210 211 /* next, try to get it from some other hardware interface */ 212 TAILQ_FOREACH(ifp, &ifnet, if_list) { 213 if (ifp == ifp0) 214 continue; 215 if (in6_get_hw_ifid(ifp, in6) == 0) 216 goto success; 217 } 218 219 /* last resort: get from random number source */ 220 in6_get_rand_ifid(ifp, in6); 221 nd6log((LOG_DEBUG, 222 "%s: interface identifier generated by random number\n", 223 ifp0->if_xname)); 224 success: 225 nd6log((LOG_INFO, "%s: ifid: %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n", 226 ifp0->if_xname, in6->s6_addr[8], in6->s6_addr[9], in6->s6_addr[10], 227 in6->s6_addr[11], in6->s6_addr[12], in6->s6_addr[13], 228 in6->s6_addr[14], in6->s6_addr[15])); 229 } 230 231 /* 232 * ifid - used as EUI64 if not NULL, overrides other EUI64 sources 233 */ 234 235 int 236 in6_ifattach_linklocal(struct ifnet *ifp, struct in6_addr *ifid) 237 { 238 struct in6_aliasreq ifra; 239 struct in6_ifaddr *ia6; 240 int error, flags; 241 242 NET_ASSERT_LOCKED(); 243 244 /* 245 * configure link-local address. 246 */ 247 bzero(&ifra, sizeof(ifra)); 248 strlcpy(ifra.ifra_name, ifp->if_xname, sizeof(ifra.ifra_name)); 249 ifra.ifra_addr.sin6_family = AF_INET6; 250 ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6); 251 ifra.ifra_addr.sin6_addr.s6_addr16[0] = htons(0xfe80); 252 ifra.ifra_addr.sin6_addr.s6_addr16[1] = htons(ifp->if_index); 253 ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0; 254 if ((ifp->if_flags & IFF_LOOPBACK) != 0) { 255 ifra.ifra_addr.sin6_addr.s6_addr32[2] = 0; 256 ifra.ifra_addr.sin6_addr.s6_addr32[3] = htonl(1); 257 } else if (ifid) { 258 ifra.ifra_addr.sin6_addr = *ifid; 259 ifra.ifra_addr.sin6_addr.s6_addr16[0] = htons(0xfe80); 260 ifra.ifra_addr.sin6_addr.s6_addr16[1] = htons(ifp->if_index); 261 ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0; 262 ifra.ifra_addr.sin6_addr.s6_addr[8] &= ~EUI64_GBIT; 263 ifra.ifra_addr.sin6_addr.s6_addr[8] |= EUI64_UBIT; 264 } else 265 in6_get_ifid(ifp, &ifra.ifra_addr.sin6_addr); 266 267 ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6); 268 ifra.ifra_prefixmask.sin6_family = AF_INET6; 269 ifra.ifra_prefixmask.sin6_addr = in6mask64; 270 /* link-local addresses should NEVER expire. */ 271 ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME; 272 ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME; 273 274 /* 275 * XXX: Some P2P interfaces seem not to send packets just after 276 * becoming up, so we skip p2p interfaces for safety. 277 */ 278 if (in6if_do_dad(ifp) && ((ifp->if_flags & IFF_POINTOPOINT) == 0)) 279 ifra.ifra_flags |= IN6_IFF_TENTATIVE; 280 281 error = in6_update_ifa(ifp, &ifra, in6ifa_ifpforlinklocal(ifp, 0)); 282 if (error != 0) 283 return (error); 284 285 ia6 = in6ifa_ifpforlinklocal(ifp, 0); 286 287 /* Perform DAD, if needed. */ 288 if (ia6->ia6_flags & IN6_IFF_TENTATIVE) 289 nd6_dad_start(&ia6->ia_ifa); 290 291 if (ifp->if_flags & IFF_LOOPBACK) { 292 if_addrhooks_run(ifp); 293 return (0); /* No need to install a connected route. */ 294 } 295 296 flags = RTF_CONNECTED | RTF_MPATH; 297 if ((ifp->if_flags & IFF_POINTOPOINT) == 0) 298 flags |= RTF_CLONING; 299 300 error = rt_ifa_add(&ia6->ia_ifa, flags, ia6->ia_ifa.ifa_addr, 301 ifp->if_rdomain); 302 if (error) { 303 in6_purgeaddr(&ia6->ia_ifa); 304 return (error); 305 } 306 if_addrhooks_run(ifp); 307 308 return (0); 309 } 310 311 int 312 in6_ifattach_loopback(struct ifnet *ifp) 313 { 314 struct in6_addr in6 = in6addr_loopback; 315 struct in6_aliasreq ifra; 316 317 KASSERT(ifp->if_flags & IFF_LOOPBACK); 318 319 if (in6ifa_ifpwithaddr(ifp, &in6) != NULL) 320 return (0); 321 322 bzero(&ifra, sizeof(ifra)); 323 strlcpy(ifra.ifra_name, ifp->if_xname, sizeof(ifra.ifra_name)); 324 ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6); 325 ifra.ifra_prefixmask.sin6_family = AF_INET6; 326 ifra.ifra_prefixmask.sin6_addr = in6mask128; 327 328 /* 329 * Always initialize ia_dstaddr (= broadcast address) to loopback 330 * address. Follows IPv4 practice - see in_ifinit(). 331 */ 332 ifra.ifra_dstaddr.sin6_len = sizeof(struct sockaddr_in6); 333 ifra.ifra_dstaddr.sin6_family = AF_INET6; 334 ifra.ifra_dstaddr.sin6_addr = in6addr_loopback; 335 336 ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6); 337 ifra.ifra_addr.sin6_family = AF_INET6; 338 ifra.ifra_addr.sin6_addr = in6addr_loopback; 339 340 /* the loopback address should NEVER expire. */ 341 ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME; 342 ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME; 343 344 /* 345 * We are sure that this is a newly assigned address, so we can set 346 * NULL to the 3rd arg. 347 */ 348 return (in6_update_ifa(ifp, &ifra, NULL)); 349 } 350 351 /* 352 * XXX multiple loopback interface needs more care. for instance, 353 * nodelocal address needs to be configured onto only one of them. 354 * XXX multiple link-local address case 355 */ 356 int 357 in6_ifattach(struct ifnet *ifp) 358 { 359 /* some of the interfaces are inherently not IPv6 capable */ 360 switch (ifp->if_type) { 361 case IFT_BRIDGE: 362 case IFT_ENC: 363 case IFT_PFLOG: 364 case IFT_PFSYNC: 365 return (0); 366 } 367 368 /* 369 * if link mtu is too small, don't try to configure IPv6. 370 * remember there could be some link-layer that has special 371 * fragmentation logic. 372 */ 373 if (ifp->if_mtu < IPV6_MMTU) 374 return (EINVAL); 375 376 if ((ifp->if_flags & IFF_MULTICAST) == 0) 377 return (EINVAL); 378 379 /* 380 * Assign loopback address if this lo(4) interface is the 381 * default for its rdomain. 382 */ 383 if ((ifp->if_flags & IFF_LOOPBACK) && 384 (ifp->if_index == rtable_loindex(ifp->if_rdomain))) { 385 int error; 386 387 error = in6_ifattach_loopback(ifp); 388 if (error) 389 return (error); 390 } 391 392 /* Interfaces that rely on strong a priori cryptographic binding of 393 * IP addresses are incompatible with automatically assigned llv6. */ 394 switch (ifp->if_type) { 395 case IFT_WIREGUARD: 396 return (0); 397 } 398 399 /* Assign a link-local address, if there's none. */ 400 if (in6ifa_ifpforlinklocal(ifp, 0) == NULL) { 401 if (in6_ifattach_linklocal(ifp, NULL) != 0) { 402 /* failed to assign linklocal address. bark? */ 403 } 404 } 405 406 return (0); 407 } 408 409 /* 410 * NOTE: in6_ifdetach() does not support loopback if at this moment. 411 */ 412 void 413 in6_ifdetach(struct ifnet *ifp) 414 { 415 struct ifaddr *ifa, *next; 416 struct rtentry *rt; 417 struct sockaddr_in6 sin6; 418 419 #ifdef MROUTING 420 /* remove ip6_mrouter stuff */ 421 ip6_mrouter_detach(ifp); 422 #endif 423 424 /* nuke any of IPv6 addresses we have */ 425 TAILQ_FOREACH_SAFE(ifa, &ifp->if_addrlist, ifa_list, next) { 426 if (ifa->ifa_addr->sa_family != AF_INET6) 427 continue; 428 in6_purgeaddr(ifa); 429 if_addrhooks_run(ifp); 430 } 431 432 /* 433 * Remove neighbor management table. Must be called after 434 * purging addresses. 435 */ 436 nd6_purge(ifp); 437 438 /* remove route to interface local allnodes multicast (ff01::1) */ 439 bzero(&sin6, sizeof(sin6)); 440 sin6.sin6_len = sizeof(struct sockaddr_in6); 441 sin6.sin6_family = AF_INET6; 442 sin6.sin6_addr = in6addr_intfacelocal_allnodes; 443 sin6.sin6_addr.s6_addr16[1] = htons(ifp->if_index); 444 rt = rtalloc(sin6tosa(&sin6), 0, ifp->if_rdomain); 445 if (rt && rt->rt_ifidx == ifp->if_index) { 446 rtdeletemsg(rt, ifp, ifp->if_rdomain); 447 rtfree(rt); 448 } 449 450 /* remove route to link-local allnodes multicast (ff02::1) */ 451 bzero(&sin6, sizeof(sin6)); 452 sin6.sin6_len = sizeof(struct sockaddr_in6); 453 sin6.sin6_family = AF_INET6; 454 sin6.sin6_addr = in6addr_linklocal_allnodes; 455 sin6.sin6_addr.s6_addr16[1] = htons(ifp->if_index); 456 rt = rtalloc(sin6tosa(&sin6), 0, ifp->if_rdomain); 457 if (rt && rt->rt_ifidx == ifp->if_index) { 458 rtdeletemsg(rt, ifp, ifp->if_rdomain); 459 rtfree(rt); 460 } 461 462 if (ifp->if_xflags & (IFXF_AUTOCONF6 | IFXF_AUTOCONF6TEMP)) 463 ifp->if_xflags &= ~(IFXF_AUTOCONF6 | IFXF_AUTOCONF6TEMP); 464 } 465