1 /* $NetBSD: if_gre.c,v 1.49 2003/12/11 00:22:29 itojun Exp $ */ 2 /* $FreeBSD$ */ 3 4 /*- 5 * Copyright (c) 1998 The NetBSD Foundation, Inc. 6 * All rights reserved. 7 * 8 * This code is derived from software contributed to The NetBSD Foundation 9 * by Heiko W.Rupp <hwr@pilhuhn.de> 10 * 11 * IPv6-over-GRE contributed by Gert Doering <gert@greenie.muc.de> 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 3. All advertising materials mentioning features or use of this software 22 * must display the following acknowledgement: 23 * This product includes software developed by the NetBSD 24 * Foundation, Inc. and its contributors. 25 * 4. Neither the name of The NetBSD Foundation nor the names of its 26 * contributors may be used to endorse or promote products derived 27 * from this software without specific prior written permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 30 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 31 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 32 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 33 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 34 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 35 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 36 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 37 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 38 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 39 * POSSIBILITY OF SUCH DAMAGE. 40 */ 41 42 /* 43 * Encapsulate L3 protocols into IP 44 * See RFC 2784 (successor of RFC 1701 and 1702) for more details. 45 * If_gre is compatible with Cisco GRE tunnels, so you can 46 * have a NetBSD box as the other end of a tunnel interface of a Cisco 47 * router. See gre(4) for more details. 48 * Also supported: IP in IP encaps (proto 55) as of RFC 2004 49 */ 50 51 #include "opt_atalk.h" 52 #include "opt_inet.h" 53 #include "opt_inet6.h" 54 55 #include <sys/param.h> 56 #include <sys/kernel.h> 57 #include <sys/malloc.h> 58 #include <sys/module.h> 59 #include <sys/mbuf.h> 60 #include <sys/priv.h> 61 #include <sys/proc.h> 62 #include <sys/protosw.h> 63 #include <sys/socket.h> 64 #include <sys/sockio.h> 65 #include <sys/sysctl.h> 66 #include <sys/systm.h> 67 68 #include <net/ethernet.h> 69 #include <net/if.h> 70 #include <net/if_clone.h> 71 #include <net/if_types.h> 72 #include <net/route.h> 73 74 #ifdef INET 75 #include <netinet/in.h> 76 #include <netinet/in_systm.h> 77 #include <netinet/in_var.h> 78 #include <netinet/ip.h> 79 #include <netinet/ip_gre.h> 80 #include <netinet/ip_var.h> 81 #include <netinet/ip_encap.h> 82 #include <netinet/vinet.h> 83 #else 84 #error "Huh? if_gre without inet?" 85 #endif 86 87 #include <net/bpf.h> 88 89 #include <net/if_gre.h> 90 91 /* 92 * It is not easy to calculate the right value for a GRE MTU. 93 * We leave this task to the admin and use the same default that 94 * other vendors use. 95 */ 96 #define GREMTU 1476 97 98 #define GRENAME "gre" 99 100 /* 101 * gre_mtx protects all global variables in if_gre.c. 102 * XXX: gre_softc data not protected yet. 103 */ 104 struct mtx gre_mtx; 105 static MALLOC_DEFINE(M_GRE, GRENAME, "Generic Routing Encapsulation"); 106 107 struct gre_softc_head gre_softc_list; 108 109 static int gre_clone_create(struct if_clone *, int, caddr_t); 110 static void gre_clone_destroy(struct ifnet *); 111 static int gre_ioctl(struct ifnet *, u_long, caddr_t); 112 static int gre_output(struct ifnet *, struct mbuf *, struct sockaddr *, 113 struct rtentry *rt); 114 115 IFC_SIMPLE_DECLARE(gre, 0); 116 117 static int gre_compute_route(struct gre_softc *sc); 118 119 static void greattach(void); 120 121 #ifdef INET 122 extern struct domain inetdomain; 123 static const struct protosw in_gre_protosw = { 124 .pr_type = SOCK_RAW, 125 .pr_domain = &inetdomain, 126 .pr_protocol = IPPROTO_GRE, 127 .pr_flags = PR_ATOMIC|PR_ADDR, 128 .pr_input = gre_input, 129 .pr_output = (pr_output_t *)rip_output, 130 .pr_ctlinput = rip_ctlinput, 131 .pr_ctloutput = rip_ctloutput, 132 .pr_usrreqs = &rip_usrreqs 133 }; 134 static const struct protosw in_mobile_protosw = { 135 .pr_type = SOCK_RAW, 136 .pr_domain = &inetdomain, 137 .pr_protocol = IPPROTO_MOBILE, 138 .pr_flags = PR_ATOMIC|PR_ADDR, 139 .pr_input = gre_mobile_input, 140 .pr_output = (pr_output_t *)rip_output, 141 .pr_ctlinput = rip_ctlinput, 142 .pr_ctloutput = rip_ctloutput, 143 .pr_usrreqs = &rip_usrreqs 144 }; 145 #endif 146 147 SYSCTL_DECL(_net_link); 148 SYSCTL_NODE(_net_link, IFT_TUNNEL, gre, CTLFLAG_RW, 0, 149 "Generic Routing Encapsulation"); 150 #ifndef MAX_GRE_NEST 151 /* 152 * This macro controls the default upper limitation on nesting of gre tunnels. 153 * Since, setting a large value to this macro with a careless configuration 154 * may introduce system crash, we don't allow any nestings by default. 155 * If you need to configure nested gre tunnels, you can define this macro 156 * in your kernel configuration file. However, if you do so, please be 157 * careful to configure the tunnels so that it won't make a loop. 158 */ 159 #define MAX_GRE_NEST 1 160 #endif 161 static int max_gre_nesting = MAX_GRE_NEST; 162 SYSCTL_INT(_net_link_gre, OID_AUTO, max_nesting, CTLFLAG_RW, 163 &max_gre_nesting, 0, "Max nested tunnels"); 164 165 /* ARGSUSED */ 166 static void 167 greattach(void) 168 { 169 170 mtx_init(&gre_mtx, "gre_mtx", NULL, MTX_DEF); 171 LIST_INIT(&gre_softc_list); 172 if_clone_attach(&gre_cloner); 173 } 174 175 static int 176 gre_clone_create(ifc, unit, params) 177 struct if_clone *ifc; 178 int unit; 179 caddr_t params; 180 { 181 struct gre_softc *sc; 182 183 sc = malloc(sizeof(struct gre_softc), M_GRE, M_WAITOK | M_ZERO); 184 185 GRE2IFP(sc) = if_alloc(IFT_TUNNEL); 186 if (GRE2IFP(sc) == NULL) { 187 free(sc, M_GRE); 188 return (ENOSPC); 189 } 190 191 GRE2IFP(sc)->if_softc = sc; 192 if_initname(GRE2IFP(sc), ifc->ifc_name, unit); 193 194 GRE2IFP(sc)->if_snd.ifq_maxlen = IFQ_MAXLEN; 195 GRE2IFP(sc)->if_addrlen = 0; 196 GRE2IFP(sc)->if_hdrlen = 24; /* IP + GRE */ 197 GRE2IFP(sc)->if_mtu = GREMTU; 198 GRE2IFP(sc)->if_flags = IFF_POINTOPOINT|IFF_MULTICAST; 199 GRE2IFP(sc)->if_output = gre_output; 200 GRE2IFP(sc)->if_ioctl = gre_ioctl; 201 sc->g_dst.s_addr = sc->g_src.s_addr = INADDR_ANY; 202 sc->g_proto = IPPROTO_GRE; 203 GRE2IFP(sc)->if_flags |= IFF_LINK0; 204 sc->encap = NULL; 205 sc->called = 0; 206 sc->gre_fibnum = curthread->td_proc->p_fibnum; 207 sc->wccp_ver = WCCP_V1; 208 sc->key = 0; 209 if_attach(GRE2IFP(sc)); 210 bpfattach(GRE2IFP(sc), DLT_NULL, sizeof(u_int32_t)); 211 mtx_lock(&gre_mtx); 212 LIST_INSERT_HEAD(&gre_softc_list, sc, sc_list); 213 mtx_unlock(&gre_mtx); 214 return (0); 215 } 216 217 static void 218 gre_clone_destroy(ifp) 219 struct ifnet *ifp; 220 { 221 struct gre_softc *sc = ifp->if_softc; 222 223 mtx_lock(&gre_mtx); 224 LIST_REMOVE(sc, sc_list); 225 mtx_unlock(&gre_mtx); 226 227 #ifdef INET 228 if (sc->encap != NULL) 229 encap_detach(sc->encap); 230 #endif 231 bpfdetach(ifp); 232 if_detach(ifp); 233 if_free(ifp); 234 free(sc, M_GRE); 235 } 236 237 /* 238 * The output routine. Takes a packet and encapsulates it in the protocol 239 * given by sc->g_proto. See also RFC 1701 and RFC 2004 240 */ 241 static int 242 gre_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 243 struct rtentry *rt) 244 { 245 #ifdef INET6 246 INIT_VNET_INET(ifp->if_vnet); 247 #endif 248 int error = 0; 249 struct gre_softc *sc = ifp->if_softc; 250 struct greip *gh; 251 struct ip *ip; 252 u_short gre_ip_id = 0; 253 uint8_t gre_ip_tos = 0; 254 u_int16_t etype = 0; 255 struct mobile_h mob_h; 256 u_int32_t af; 257 int extra = 0; 258 259 /* 260 * gre may cause infinite recursion calls when misconfigured. 261 * We'll prevent this by introducing upper limit. 262 */ 263 if (++(sc->called) > max_gre_nesting) { 264 printf("%s: gre_output: recursively called too many " 265 "times(%d)\n", if_name(GRE2IFP(sc)), sc->called); 266 m_freem(m); 267 error = EIO; /* is there better errno? */ 268 goto end; 269 } 270 271 if (!((ifp->if_flags & IFF_UP) && 272 (ifp->if_drv_flags & IFF_DRV_RUNNING)) || 273 sc->g_src.s_addr == INADDR_ANY || sc->g_dst.s_addr == INADDR_ANY) { 274 m_freem(m); 275 error = ENETDOWN; 276 goto end; 277 } 278 279 gh = NULL; 280 ip = NULL; 281 282 /* BPF writes need to be handled specially. */ 283 if (dst->sa_family == AF_UNSPEC) { 284 bcopy(dst->sa_data, &af, sizeof(af)); 285 dst->sa_family = af; 286 } 287 288 if (bpf_peers_present(ifp->if_bpf)) { 289 af = dst->sa_family; 290 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 291 } 292 293 m->m_flags &= ~(M_BCAST|M_MCAST); 294 295 if (sc->g_proto == IPPROTO_MOBILE) { 296 if (dst->sa_family == AF_INET) { 297 struct mbuf *m0; 298 int msiz; 299 300 ip = mtod(m, struct ip *); 301 302 /* 303 * RFC2004 specifies that fragmented diagrams shouldn't 304 * be encapsulated. 305 */ 306 if (ip->ip_off & (IP_MF | IP_OFFMASK)) { 307 _IF_DROP(&ifp->if_snd); 308 m_freem(m); 309 error = EINVAL; /* is there better errno? */ 310 goto end; 311 } 312 memset(&mob_h, 0, MOB_H_SIZ_L); 313 mob_h.proto = (ip->ip_p) << 8; 314 mob_h.odst = ip->ip_dst.s_addr; 315 ip->ip_dst.s_addr = sc->g_dst.s_addr; 316 317 /* 318 * If the packet comes from our host, we only change 319 * the destination address in the IP header. 320 * Else we also need to save and change the source 321 */ 322 if (in_hosteq(ip->ip_src, sc->g_src)) { 323 msiz = MOB_H_SIZ_S; 324 } else { 325 mob_h.proto |= MOB_H_SBIT; 326 mob_h.osrc = ip->ip_src.s_addr; 327 ip->ip_src.s_addr = sc->g_src.s_addr; 328 msiz = MOB_H_SIZ_L; 329 } 330 mob_h.proto = htons(mob_h.proto); 331 mob_h.hcrc = gre_in_cksum((u_int16_t *)&mob_h, msiz); 332 333 if ((m->m_data - msiz) < m->m_pktdat) { 334 /* need new mbuf */ 335 MGETHDR(m0, M_DONTWAIT, MT_DATA); 336 if (m0 == NULL) { 337 _IF_DROP(&ifp->if_snd); 338 m_freem(m); 339 error = ENOBUFS; 340 goto end; 341 } 342 m0->m_next = m; 343 m->m_data += sizeof(struct ip); 344 m->m_len -= sizeof(struct ip); 345 m0->m_pkthdr.len = m->m_pkthdr.len + msiz; 346 m0->m_len = msiz + sizeof(struct ip); 347 m0->m_data += max_linkhdr; 348 memcpy(mtod(m0, caddr_t), (caddr_t)ip, 349 sizeof(struct ip)); 350 m = m0; 351 } else { /* we have some space left in the old one */ 352 m->m_data -= msiz; 353 m->m_len += msiz; 354 m->m_pkthdr.len += msiz; 355 bcopy(ip, mtod(m, caddr_t), 356 sizeof(struct ip)); 357 } 358 ip = mtod(m, struct ip *); 359 memcpy((caddr_t)(ip + 1), &mob_h, (unsigned)msiz); 360 ip->ip_len = ntohs(ip->ip_len) + msiz; 361 } else { /* AF_INET */ 362 _IF_DROP(&ifp->if_snd); 363 m_freem(m); 364 error = EINVAL; 365 goto end; 366 } 367 } else if (sc->g_proto == IPPROTO_GRE) { 368 switch (dst->sa_family) { 369 case AF_INET: 370 ip = mtod(m, struct ip *); 371 gre_ip_tos = ip->ip_tos; 372 gre_ip_id = ip->ip_id; 373 if (sc->wccp_ver == WCCP_V2) { 374 extra = sizeof(uint32_t); 375 etype = WCCP_PROTOCOL_TYPE; 376 } else { 377 etype = ETHERTYPE_IP; 378 } 379 break; 380 #ifdef INET6 381 case AF_INET6: 382 gre_ip_id = ip_newid(); 383 etype = ETHERTYPE_IPV6; 384 break; 385 #endif 386 #ifdef NETATALK 387 case AF_APPLETALK: 388 etype = ETHERTYPE_ATALK; 389 break; 390 #endif 391 default: 392 _IF_DROP(&ifp->if_snd); 393 m_freem(m); 394 error = EAFNOSUPPORT; 395 goto end; 396 } 397 398 /* Reserve space for GRE header + optional GRE key */ 399 int hdrlen = sizeof(struct greip) + extra; 400 if (sc->key) 401 hdrlen += sizeof(uint32_t); 402 M_PREPEND(m, hdrlen, M_DONTWAIT); 403 } else { 404 _IF_DROP(&ifp->if_snd); 405 m_freem(m); 406 error = EINVAL; 407 goto end; 408 } 409 410 if (m == NULL) { /* mbuf allocation failed */ 411 _IF_DROP(&ifp->if_snd); 412 error = ENOBUFS; 413 goto end; 414 } 415 416 M_SETFIB(m, sc->gre_fibnum); /* The envelope may use a different FIB */ 417 418 gh = mtod(m, struct greip *); 419 if (sc->g_proto == IPPROTO_GRE) { 420 uint32_t *options = gh->gi_options; 421 422 memset((void *)gh, 0, sizeof(struct greip) + extra); 423 gh->gi_ptype = htons(etype); 424 gh->gi_flags = 0; 425 426 /* Add key option */ 427 if (sc->key) 428 { 429 gh->gi_flags |= htons(GRE_KP); 430 *(options++) = htonl(sc->key); 431 } 432 } 433 434 gh->gi_pr = sc->g_proto; 435 if (sc->g_proto != IPPROTO_MOBILE) { 436 gh->gi_src = sc->g_src; 437 gh->gi_dst = sc->g_dst; 438 ((struct ip*)gh)->ip_v = IPPROTO_IPV4; 439 ((struct ip*)gh)->ip_hl = (sizeof(struct ip)) >> 2; 440 ((struct ip*)gh)->ip_ttl = GRE_TTL; 441 ((struct ip*)gh)->ip_tos = gre_ip_tos; 442 ((struct ip*)gh)->ip_id = gre_ip_id; 443 gh->gi_len = m->m_pkthdr.len; 444 } 445 446 ifp->if_opackets++; 447 ifp->if_obytes += m->m_pkthdr.len; 448 /* 449 * Send it off and with IP_FORWARD flag to prevent it from 450 * overwriting the ip_id again. ip_id is already set to the 451 * ip_id of the encapsulated packet. 452 */ 453 error = ip_output(m, NULL, &sc->route, IP_FORWARDING, 454 (struct ip_moptions *)NULL, (struct inpcb *)NULL); 455 end: 456 sc->called = 0; 457 if (error) 458 ifp->if_oerrors++; 459 return (error); 460 } 461 462 static int 463 gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 464 { 465 struct ifreq *ifr = (struct ifreq *)data; 466 struct if_laddrreq *lifr = (struct if_laddrreq *)data; 467 struct in_aliasreq *aifr = (struct in_aliasreq *)data; 468 struct gre_softc *sc = ifp->if_softc; 469 int s; 470 struct sockaddr_in si; 471 struct sockaddr *sa = NULL; 472 int error, adj; 473 struct sockaddr_in sp, sm, dp, dm; 474 uint32_t key; 475 476 error = 0; 477 adj = 0; 478 479 s = splnet(); 480 switch (cmd) { 481 case SIOCSIFADDR: 482 ifp->if_flags |= IFF_UP; 483 break; 484 case SIOCSIFDSTADDR: 485 break; 486 case SIOCSIFFLAGS: 487 /* 488 * XXXRW: Isn't this priv_check() redundant to the ifnet 489 * layer check? 490 */ 491 if ((error = priv_check(curthread, PRIV_NET_SETIFFLAGS)) != 0) 492 break; 493 if ((ifr->ifr_flags & IFF_LINK0) != 0) 494 sc->g_proto = IPPROTO_GRE; 495 else 496 sc->g_proto = IPPROTO_MOBILE; 497 if ((ifr->ifr_flags & IFF_LINK2) != 0) 498 sc->wccp_ver = WCCP_V2; 499 else 500 sc->wccp_ver = WCCP_V1; 501 goto recompute; 502 case SIOCSIFMTU: 503 /* 504 * XXXRW: Isn't this priv_check() redundant to the ifnet 505 * layer check? 506 */ 507 if ((error = priv_check(curthread, PRIV_NET_SETIFMTU)) != 0) 508 break; 509 if (ifr->ifr_mtu < 576) { 510 error = EINVAL; 511 break; 512 } 513 ifp->if_mtu = ifr->ifr_mtu; 514 break; 515 case SIOCGIFMTU: 516 ifr->ifr_mtu = GRE2IFP(sc)->if_mtu; 517 break; 518 case SIOCADDMULTI: 519 /* 520 * XXXRW: Isn't this priv_checkr() redundant to the ifnet 521 * layer check? 522 */ 523 if ((error = priv_check(curthread, PRIV_NET_ADDMULTI)) != 0) 524 break; 525 if (ifr == 0) { 526 error = EAFNOSUPPORT; 527 break; 528 } 529 switch (ifr->ifr_addr.sa_family) { 530 #ifdef INET 531 case AF_INET: 532 break; 533 #endif 534 #ifdef INET6 535 case AF_INET6: 536 break; 537 #endif 538 default: 539 error = EAFNOSUPPORT; 540 break; 541 } 542 break; 543 case SIOCDELMULTI: 544 /* 545 * XXXRW: Isn't this priv_check() redundant to the ifnet 546 * layer check? 547 */ 548 if ((error = priv_check(curthread, PRIV_NET_DELIFGROUP)) != 0) 549 break; 550 if (ifr == 0) { 551 error = EAFNOSUPPORT; 552 break; 553 } 554 switch (ifr->ifr_addr.sa_family) { 555 #ifdef INET 556 case AF_INET: 557 break; 558 #endif 559 #ifdef INET6 560 case AF_INET6: 561 break; 562 #endif 563 default: 564 error = EAFNOSUPPORT; 565 break; 566 } 567 break; 568 case GRESPROTO: 569 /* 570 * XXXRW: Isn't this priv_check() redundant to the ifnet 571 * layer check? 572 */ 573 if ((error = priv_check(curthread, PRIV_NET_GRE)) != 0) 574 break; 575 sc->g_proto = ifr->ifr_flags; 576 switch (sc->g_proto) { 577 case IPPROTO_GRE: 578 ifp->if_flags |= IFF_LINK0; 579 break; 580 case IPPROTO_MOBILE: 581 ifp->if_flags &= ~IFF_LINK0; 582 break; 583 default: 584 error = EPROTONOSUPPORT; 585 break; 586 } 587 goto recompute; 588 case GREGPROTO: 589 ifr->ifr_flags = sc->g_proto; 590 break; 591 case GRESADDRS: 592 case GRESADDRD: 593 error = priv_check(curthread, PRIV_NET_GRE); 594 if (error) 595 return (error); 596 /* 597 * set tunnel endpoints, compute a less specific route 598 * to the remote end and mark if as up 599 */ 600 sa = &ifr->ifr_addr; 601 if (cmd == GRESADDRS) 602 sc->g_src = (satosin(sa))->sin_addr; 603 if (cmd == GRESADDRD) 604 sc->g_dst = (satosin(sa))->sin_addr; 605 recompute: 606 #ifdef INET 607 if (sc->encap != NULL) { 608 encap_detach(sc->encap); 609 sc->encap = NULL; 610 } 611 #endif 612 if ((sc->g_src.s_addr != INADDR_ANY) && 613 (sc->g_dst.s_addr != INADDR_ANY)) { 614 bzero(&sp, sizeof(sp)); 615 bzero(&sm, sizeof(sm)); 616 bzero(&dp, sizeof(dp)); 617 bzero(&dm, sizeof(dm)); 618 sp.sin_len = sm.sin_len = dp.sin_len = dm.sin_len = 619 sizeof(struct sockaddr_in); 620 sp.sin_family = sm.sin_family = dp.sin_family = 621 dm.sin_family = AF_INET; 622 sp.sin_addr = sc->g_src; 623 dp.sin_addr = sc->g_dst; 624 sm.sin_addr.s_addr = dm.sin_addr.s_addr = 625 INADDR_BROADCAST; 626 #ifdef INET 627 sc->encap = encap_attach(AF_INET, sc->g_proto, 628 sintosa(&sp), sintosa(&sm), sintosa(&dp), 629 sintosa(&dm), (sc->g_proto == IPPROTO_GRE) ? 630 &in_gre_protosw : &in_mobile_protosw, sc); 631 if (sc->encap == NULL) 632 printf("%s: unable to attach encap\n", 633 if_name(GRE2IFP(sc))); 634 #endif 635 if (sc->route.ro_rt != 0) /* free old route */ 636 RTFREE(sc->route.ro_rt); 637 if (gre_compute_route(sc) == 0) 638 ifp->if_drv_flags |= IFF_DRV_RUNNING; 639 else 640 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 641 } 642 break; 643 case GREGADDRS: 644 memset(&si, 0, sizeof(si)); 645 si.sin_family = AF_INET; 646 si.sin_len = sizeof(struct sockaddr_in); 647 si.sin_addr.s_addr = sc->g_src.s_addr; 648 sa = sintosa(&si); 649 ifr->ifr_addr = *sa; 650 break; 651 case GREGADDRD: 652 memset(&si, 0, sizeof(si)); 653 si.sin_family = AF_INET; 654 si.sin_len = sizeof(struct sockaddr_in); 655 si.sin_addr.s_addr = sc->g_dst.s_addr; 656 sa = sintosa(&si); 657 ifr->ifr_addr = *sa; 658 break; 659 case SIOCSIFPHYADDR: 660 /* 661 * XXXRW: Isn't this priv_check() redundant to the ifnet 662 * layer check? 663 */ 664 if ((error = priv_check(curthread, PRIV_NET_SETIFPHYS)) != 0) 665 break; 666 if (aifr->ifra_addr.sin_family != AF_INET || 667 aifr->ifra_dstaddr.sin_family != AF_INET) { 668 error = EAFNOSUPPORT; 669 break; 670 } 671 if (aifr->ifra_addr.sin_len != sizeof(si) || 672 aifr->ifra_dstaddr.sin_len != sizeof(si)) { 673 error = EINVAL; 674 break; 675 } 676 sc->g_src = aifr->ifra_addr.sin_addr; 677 sc->g_dst = aifr->ifra_dstaddr.sin_addr; 678 goto recompute; 679 case SIOCSLIFPHYADDR: 680 /* 681 * XXXRW: Isn't this priv_check() redundant to the ifnet 682 * layer check? 683 */ 684 if ((error = priv_check(curthread, PRIV_NET_SETIFPHYS)) != 0) 685 break; 686 if (lifr->addr.ss_family != AF_INET || 687 lifr->dstaddr.ss_family != AF_INET) { 688 error = EAFNOSUPPORT; 689 break; 690 } 691 if (lifr->addr.ss_len != sizeof(si) || 692 lifr->dstaddr.ss_len != sizeof(si)) { 693 error = EINVAL; 694 break; 695 } 696 sc->g_src = (satosin(&lifr->addr))->sin_addr; 697 sc->g_dst = 698 (satosin(&lifr->dstaddr))->sin_addr; 699 goto recompute; 700 case SIOCDIFPHYADDR: 701 /* 702 * XXXRW: Isn't this priv_check() redundant to the ifnet 703 * layer check? 704 */ 705 if ((error = priv_check(curthread, PRIV_NET_SETIFPHYS)) != 0) 706 break; 707 sc->g_src.s_addr = INADDR_ANY; 708 sc->g_dst.s_addr = INADDR_ANY; 709 goto recompute; 710 case SIOCGLIFPHYADDR: 711 if (sc->g_src.s_addr == INADDR_ANY || 712 sc->g_dst.s_addr == INADDR_ANY) { 713 error = EADDRNOTAVAIL; 714 break; 715 } 716 memset(&si, 0, sizeof(si)); 717 si.sin_family = AF_INET; 718 si.sin_len = sizeof(struct sockaddr_in); 719 si.sin_addr.s_addr = sc->g_src.s_addr; 720 memcpy(&lifr->addr, &si, sizeof(si)); 721 si.sin_addr.s_addr = sc->g_dst.s_addr; 722 memcpy(&lifr->dstaddr, &si, sizeof(si)); 723 break; 724 case SIOCGIFPSRCADDR: 725 #ifdef INET6 726 case SIOCGIFPSRCADDR_IN6: 727 #endif 728 if (sc->g_src.s_addr == INADDR_ANY) { 729 error = EADDRNOTAVAIL; 730 break; 731 } 732 memset(&si, 0, sizeof(si)); 733 si.sin_family = AF_INET; 734 si.sin_len = sizeof(struct sockaddr_in); 735 si.sin_addr.s_addr = sc->g_src.s_addr; 736 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr)); 737 break; 738 case SIOCGIFPDSTADDR: 739 #ifdef INET6 740 case SIOCGIFPDSTADDR_IN6: 741 #endif 742 if (sc->g_dst.s_addr == INADDR_ANY) { 743 error = EADDRNOTAVAIL; 744 break; 745 } 746 memset(&si, 0, sizeof(si)); 747 si.sin_family = AF_INET; 748 si.sin_len = sizeof(struct sockaddr_in); 749 si.sin_addr.s_addr = sc->g_dst.s_addr; 750 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr)); 751 break; 752 case GRESKEY: 753 error = priv_check(curthread, PRIV_NET_GRE); 754 if (error) 755 break; 756 error = copyin(ifr->ifr_data, &key, sizeof(key)); 757 if (error) 758 break; 759 /* adjust MTU for option header */ 760 if (key == 0 && sc->key != 0) /* clear */ 761 adj += sizeof(key); 762 else if (key != 0 && sc->key == 0) /* set */ 763 adj -= sizeof(key); 764 765 if (ifp->if_mtu + adj < 576) { 766 error = EINVAL; 767 break; 768 } 769 ifp->if_mtu += adj; 770 sc->key = key; 771 break; 772 case GREGKEY: 773 error = copyout(&sc->key, ifr->ifr_data, sizeof(sc->key)); 774 break; 775 776 default: 777 error = EINVAL; 778 break; 779 } 780 781 splx(s); 782 return (error); 783 } 784 785 /* 786 * computes a route to our destination that is not the one 787 * which would be taken by ip_output(), as this one will loop back to 788 * us. If the interface is p2p as a--->b, then a routing entry exists 789 * If we now send a packet to b (e.g. ping b), this will come down here 790 * gets src=a, dst=b tacked on and would from ip_output() sent back to 791 * if_gre. 792 * Goal here is to compute a route to b that is less specific than 793 * a-->b. We know that this one exists as in normal operation we have 794 * at least a default route which matches. 795 */ 796 static int 797 gre_compute_route(struct gre_softc *sc) 798 { 799 struct route *ro; 800 801 ro = &sc->route; 802 803 memset(ro, 0, sizeof(struct route)); 804 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst; 805 ro->ro_dst.sa_family = AF_INET; 806 ro->ro_dst.sa_len = sizeof(ro->ro_dst); 807 808 /* 809 * toggle last bit, so our interface is not found, but a less 810 * specific route. I'd rather like to specify a shorter mask, 811 * but this is not possible. Should work though. XXX 812 * XXX MRT Use a different FIB for the tunnel to solve this problem. 813 */ 814 if ((GRE2IFP(sc)->if_flags & IFF_LINK1) == 0) { 815 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr.s_addr ^= 816 htonl(0x01); 817 } 818 819 #ifdef DIAGNOSTIC 820 printf("%s: searching for a route to %s", if_name(GRE2IFP(sc)), 821 inet_ntoa(((struct sockaddr_in *)&ro->ro_dst)->sin_addr)); 822 #endif 823 824 rtalloc_fib(ro, sc->gre_fibnum); 825 826 /* 827 * check if this returned a route at all and this route is no 828 * recursion to ourself 829 */ 830 if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp->if_softc == sc) { 831 #ifdef DIAGNOSTIC 832 if (ro->ro_rt == NULL) 833 printf(" - no route found!\n"); 834 else 835 printf(" - route loops back to ourself!\n"); 836 #endif 837 return EADDRNOTAVAIL; 838 } 839 840 /* 841 * now change it back - else ip_output will just drop 842 * the route and search one to this interface ... 843 */ 844 if ((GRE2IFP(sc)->if_flags & IFF_LINK1) == 0) 845 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst; 846 847 #ifdef DIAGNOSTIC 848 printf(", choosing %s with gateway %s", if_name(ro->ro_rt->rt_ifp), 849 inet_ntoa(((struct sockaddr_in *)(ro->ro_rt->rt_gateway))->sin_addr)); 850 printf("\n"); 851 #endif 852 853 return 0; 854 } 855 856 /* 857 * do a checksum of a buffer - much like in_cksum, which operates on 858 * mbufs. 859 */ 860 u_int16_t 861 gre_in_cksum(u_int16_t *p, u_int len) 862 { 863 u_int32_t sum = 0; 864 int nwords = len >> 1; 865 866 while (nwords-- != 0) 867 sum += *p++; 868 869 if (len & 1) { 870 union { 871 u_short w; 872 u_char c[2]; 873 } u; 874 u.c[0] = *(u_char *)p; 875 u.c[1] = 0; 876 sum += u.w; 877 } 878 879 /* end-around-carry */ 880 sum = (sum >> 16) + (sum & 0xffff); 881 sum += (sum >> 16); 882 return (~sum); 883 } 884 885 static int 886 gremodevent(module_t mod, int type, void *data) 887 { 888 889 switch (type) { 890 case MOD_LOAD: 891 greattach(); 892 break; 893 case MOD_UNLOAD: 894 if_clone_detach(&gre_cloner); 895 mtx_destroy(&gre_mtx); 896 break; 897 default: 898 return EOPNOTSUPP; 899 } 900 return 0; 901 } 902 903 static moduledata_t gre_mod = { 904 "if_gre", 905 gremodevent, 906 0 907 }; 908 909 DECLARE_MODULE(if_gre, gre_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 910 MODULE_VERSION(if_gre, 1); 911