if_gre.c revision 196019
1/* $NetBSD: if_gre.c,v 1.49 2003/12/11 00:22:29 itojun Exp $ */ 2/* $FreeBSD: head/sys/net/if_gre.c 196019 2009-08-01 19:26:27Z rwatson $ */ 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#include <net/vnet.h> 74 75#ifdef INET 76#include <netinet/in.h> 77#include <netinet/in_systm.h> 78#include <netinet/in_var.h> 79#include <netinet/ip.h> 80#include <netinet/ip_gre.h> 81#include <netinet/ip_var.h> 82#include <netinet/ip_encap.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 */ 104struct mtx gre_mtx; 105static MALLOC_DEFINE(M_GRE, GRENAME, "Generic Routing Encapsulation"); 106 107struct gre_softc_head gre_softc_list; 108 109static int gre_clone_create(struct if_clone *, int, caddr_t); 110static void gre_clone_destroy(struct ifnet *); 111static int gre_ioctl(struct ifnet *, u_long, caddr_t); 112static int gre_output(struct ifnet *, struct mbuf *, struct sockaddr *, 113 struct route *ro); 114 115IFC_SIMPLE_DECLARE(gre, 0); 116 117static int gre_compute_route(struct gre_softc *sc); 118 119static void greattach(void); 120 121#ifdef INET 122extern struct domain inetdomain; 123static 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}; 134static 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 147SYSCTL_DECL(_net_link); 148SYSCTL_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 161static int max_gre_nesting = MAX_GRE_NEST; 162SYSCTL_INT(_net_link_gre, OID_AUTO, max_nesting, CTLFLAG_RW, 163 &max_gre_nesting, 0, "Max nested tunnels"); 164 165/* ARGSUSED */ 166static void 167greattach(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 175static int 176gre_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 217static void 218gre_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 */ 241static int 242gre_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 243 struct route *ro) 244{ 245 int error = 0; 246 struct gre_softc *sc = ifp->if_softc; 247 struct greip *gh; 248 struct ip *ip; 249 u_short gre_ip_id = 0; 250 uint8_t gre_ip_tos = 0; 251 u_int16_t etype = 0; 252 struct mobile_h mob_h; 253 u_int32_t af; 254 int extra = 0; 255 256 /* 257 * gre may cause infinite recursion calls when misconfigured. 258 * We'll prevent this by introducing upper limit. 259 */ 260 if (++(sc->called) > max_gre_nesting) { 261 printf("%s: gre_output: recursively called too many " 262 "times(%d)\n", if_name(GRE2IFP(sc)), sc->called); 263 m_freem(m); 264 error = EIO; /* is there better errno? */ 265 goto end; 266 } 267 268 if (!((ifp->if_flags & IFF_UP) && 269 (ifp->if_drv_flags & IFF_DRV_RUNNING)) || 270 sc->g_src.s_addr == INADDR_ANY || sc->g_dst.s_addr == INADDR_ANY) { 271 m_freem(m); 272 error = ENETDOWN; 273 goto end; 274 } 275 276 gh = NULL; 277 ip = NULL; 278 279 /* BPF writes need to be handled specially. */ 280 if (dst->sa_family == AF_UNSPEC) { 281 bcopy(dst->sa_data, &af, sizeof(af)); 282 dst->sa_family = af; 283 } 284 285 if (bpf_peers_present(ifp->if_bpf)) { 286 af = dst->sa_family; 287 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 288 } 289 290 m->m_flags &= ~(M_BCAST|M_MCAST); 291 292 if (sc->g_proto == IPPROTO_MOBILE) { 293 if (dst->sa_family == AF_INET) { 294 struct mbuf *m0; 295 int msiz; 296 297 ip = mtod(m, struct ip *); 298 299 /* 300 * RFC2004 specifies that fragmented diagrams shouldn't 301 * be encapsulated. 302 */ 303 if (ip->ip_off & (IP_MF | IP_OFFMASK)) { 304 _IF_DROP(&ifp->if_snd); 305 m_freem(m); 306 error = EINVAL; /* is there better errno? */ 307 goto end; 308 } 309 memset(&mob_h, 0, MOB_H_SIZ_L); 310 mob_h.proto = (ip->ip_p) << 8; 311 mob_h.odst = ip->ip_dst.s_addr; 312 ip->ip_dst.s_addr = sc->g_dst.s_addr; 313 314 /* 315 * If the packet comes from our host, we only change 316 * the destination address in the IP header. 317 * Else we also need to save and change the source 318 */ 319 if (in_hosteq(ip->ip_src, sc->g_src)) { 320 msiz = MOB_H_SIZ_S; 321 } else { 322 mob_h.proto |= MOB_H_SBIT; 323 mob_h.osrc = ip->ip_src.s_addr; 324 ip->ip_src.s_addr = sc->g_src.s_addr; 325 msiz = MOB_H_SIZ_L; 326 } 327 mob_h.proto = htons(mob_h.proto); 328 mob_h.hcrc = gre_in_cksum((u_int16_t *)&mob_h, msiz); 329 330 if ((m->m_data - msiz) < m->m_pktdat) { 331 /* need new mbuf */ 332 MGETHDR(m0, M_DONTWAIT, MT_DATA); 333 if (m0 == NULL) { 334 _IF_DROP(&ifp->if_snd); 335 m_freem(m); 336 error = ENOBUFS; 337 goto end; 338 } 339 m0->m_next = m; 340 m->m_data += sizeof(struct ip); 341 m->m_len -= sizeof(struct ip); 342 m0->m_pkthdr.len = m->m_pkthdr.len + msiz; 343 m0->m_len = msiz + sizeof(struct ip); 344 m0->m_data += max_linkhdr; 345 memcpy(mtod(m0, caddr_t), (caddr_t)ip, 346 sizeof(struct ip)); 347 m = m0; 348 } else { /* we have some space left in the old one */ 349 m->m_data -= msiz; 350 m->m_len += msiz; 351 m->m_pkthdr.len += msiz; 352 bcopy(ip, mtod(m, caddr_t), 353 sizeof(struct ip)); 354 } 355 ip = mtod(m, struct ip *); 356 memcpy((caddr_t)(ip + 1), &mob_h, (unsigned)msiz); 357 ip->ip_len = ntohs(ip->ip_len) + msiz; 358 } else { /* AF_INET */ 359 _IF_DROP(&ifp->if_snd); 360 m_freem(m); 361 error = EINVAL; 362 goto end; 363 } 364 } else if (sc->g_proto == IPPROTO_GRE) { 365 switch (dst->sa_family) { 366 case AF_INET: 367 ip = mtod(m, struct ip *); 368 gre_ip_tos = ip->ip_tos; 369 gre_ip_id = ip->ip_id; 370 if (sc->wccp_ver == WCCP_V2) { 371 extra = sizeof(uint32_t); 372 etype = WCCP_PROTOCOL_TYPE; 373 } else { 374 etype = ETHERTYPE_IP; 375 } 376 break; 377#ifdef INET6 378 case AF_INET6: 379 gre_ip_id = ip_newid(); 380 etype = ETHERTYPE_IPV6; 381 break; 382#endif 383#ifdef NETATALK 384 case AF_APPLETALK: 385 etype = ETHERTYPE_ATALK; 386 break; 387#endif 388 default: 389 _IF_DROP(&ifp->if_snd); 390 m_freem(m); 391 error = EAFNOSUPPORT; 392 goto end; 393 } 394 395 /* Reserve space for GRE header + optional GRE key */ 396 int hdrlen = sizeof(struct greip) + extra; 397 if (sc->key) 398 hdrlen += sizeof(uint32_t); 399 M_PREPEND(m, hdrlen, M_DONTWAIT); 400 } else { 401 _IF_DROP(&ifp->if_snd); 402 m_freem(m); 403 error = EINVAL; 404 goto end; 405 } 406 407 if (m == NULL) { /* mbuf allocation failed */ 408 _IF_DROP(&ifp->if_snd); 409 error = ENOBUFS; 410 goto end; 411 } 412 413 M_SETFIB(m, sc->gre_fibnum); /* The envelope may use a different FIB */ 414 415 gh = mtod(m, struct greip *); 416 if (sc->g_proto == IPPROTO_GRE) { 417 uint32_t *options = gh->gi_options; 418 419 memset((void *)gh, 0, sizeof(struct greip) + extra); 420 gh->gi_ptype = htons(etype); 421 gh->gi_flags = 0; 422 423 /* Add key option */ 424 if (sc->key) 425 { 426 gh->gi_flags |= htons(GRE_KP); 427 *(options++) = htonl(sc->key); 428 } 429 } 430 431 gh->gi_pr = sc->g_proto; 432 if (sc->g_proto != IPPROTO_MOBILE) { 433 gh->gi_src = sc->g_src; 434 gh->gi_dst = sc->g_dst; 435 ((struct ip*)gh)->ip_v = IPPROTO_IPV4; 436 ((struct ip*)gh)->ip_hl = (sizeof(struct ip)) >> 2; 437 ((struct ip*)gh)->ip_ttl = GRE_TTL; 438 ((struct ip*)gh)->ip_tos = gre_ip_tos; 439 ((struct ip*)gh)->ip_id = gre_ip_id; 440 gh->gi_len = m->m_pkthdr.len; 441 } 442 443 ifp->if_opackets++; 444 ifp->if_obytes += m->m_pkthdr.len; 445 /* 446 * Send it off and with IP_FORWARD flag to prevent it from 447 * overwriting the ip_id again. ip_id is already set to the 448 * ip_id of the encapsulated packet. 449 */ 450 error = ip_output(m, NULL, &sc->route, IP_FORWARDING, 451 (struct ip_moptions *)NULL, (struct inpcb *)NULL); 452 end: 453 sc->called = 0; 454 if (error) 455 ifp->if_oerrors++; 456 return (error); 457} 458 459static int 460gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 461{ 462 struct ifreq *ifr = (struct ifreq *)data; 463 struct if_laddrreq *lifr = (struct if_laddrreq *)data; 464 struct in_aliasreq *aifr = (struct in_aliasreq *)data; 465 struct gre_softc *sc = ifp->if_softc; 466 int s; 467 struct sockaddr_in si; 468 struct sockaddr *sa = NULL; 469 int error, adj; 470 struct sockaddr_in sp, sm, dp, dm; 471 uint32_t key; 472 473 error = 0; 474 adj = 0; 475 476 s = splnet(); 477 switch (cmd) { 478 case SIOCSIFADDR: 479 ifp->if_flags |= IFF_UP; 480 break; 481 case SIOCSIFDSTADDR: 482 break; 483 case SIOCSIFFLAGS: 484 /* 485 * XXXRW: Isn't this priv_check() redundant to the ifnet 486 * layer check? 487 */ 488 if ((error = priv_check(curthread, PRIV_NET_SETIFFLAGS)) != 0) 489 break; 490 if ((ifr->ifr_flags & IFF_LINK0) != 0) 491 sc->g_proto = IPPROTO_GRE; 492 else 493 sc->g_proto = IPPROTO_MOBILE; 494 if ((ifr->ifr_flags & IFF_LINK2) != 0) 495 sc->wccp_ver = WCCP_V2; 496 else 497 sc->wccp_ver = WCCP_V1; 498 goto recompute; 499 case SIOCSIFMTU: 500 /* 501 * XXXRW: Isn't this priv_check() redundant to the ifnet 502 * layer check? 503 */ 504 if ((error = priv_check(curthread, PRIV_NET_SETIFMTU)) != 0) 505 break; 506 if (ifr->ifr_mtu < 576) { 507 error = EINVAL; 508 break; 509 } 510 ifp->if_mtu = ifr->ifr_mtu; 511 break; 512 case SIOCGIFMTU: 513 ifr->ifr_mtu = GRE2IFP(sc)->if_mtu; 514 break; 515 case SIOCADDMULTI: 516 /* 517 * XXXRW: Isn't this priv_checkr() redundant to the ifnet 518 * layer check? 519 */ 520 if ((error = priv_check(curthread, PRIV_NET_ADDMULTI)) != 0) 521 break; 522 if (ifr == 0) { 523 error = EAFNOSUPPORT; 524 break; 525 } 526 switch (ifr->ifr_addr.sa_family) { 527#ifdef INET 528 case AF_INET: 529 break; 530#endif 531#ifdef INET6 532 case AF_INET6: 533 break; 534#endif 535 default: 536 error = EAFNOSUPPORT; 537 break; 538 } 539 break; 540 case SIOCDELMULTI: 541 /* 542 * XXXRW: Isn't this priv_check() redundant to the ifnet 543 * layer check? 544 */ 545 if ((error = priv_check(curthread, PRIV_NET_DELIFGROUP)) != 0) 546 break; 547 if (ifr == 0) { 548 error = EAFNOSUPPORT; 549 break; 550 } 551 switch (ifr->ifr_addr.sa_family) { 552#ifdef INET 553 case AF_INET: 554 break; 555#endif 556#ifdef INET6 557 case AF_INET6: 558 break; 559#endif 560 default: 561 error = EAFNOSUPPORT; 562 break; 563 } 564 break; 565 case GRESPROTO: 566 /* 567 * XXXRW: Isn't this priv_check() redundant to the ifnet 568 * layer check? 569 */ 570 if ((error = priv_check(curthread, PRIV_NET_GRE)) != 0) 571 break; 572 sc->g_proto = ifr->ifr_flags; 573 switch (sc->g_proto) { 574 case IPPROTO_GRE: 575 ifp->if_flags |= IFF_LINK0; 576 break; 577 case IPPROTO_MOBILE: 578 ifp->if_flags &= ~IFF_LINK0; 579 break; 580 default: 581 error = EPROTONOSUPPORT; 582 break; 583 } 584 goto recompute; 585 case GREGPROTO: 586 ifr->ifr_flags = sc->g_proto; 587 break; 588 case GRESADDRS: 589 case GRESADDRD: 590 error = priv_check(curthread, PRIV_NET_GRE); 591 if (error) 592 return (error); 593 /* 594 * set tunnel endpoints, compute a less specific route 595 * to the remote end and mark if as up 596 */ 597 sa = &ifr->ifr_addr; 598 if (cmd == GRESADDRS) 599 sc->g_src = (satosin(sa))->sin_addr; 600 if (cmd == GRESADDRD) 601 sc->g_dst = (satosin(sa))->sin_addr; 602 recompute: 603#ifdef INET 604 if (sc->encap != NULL) { 605 encap_detach(sc->encap); 606 sc->encap = NULL; 607 } 608#endif 609 if ((sc->g_src.s_addr != INADDR_ANY) && 610 (sc->g_dst.s_addr != INADDR_ANY)) { 611 bzero(&sp, sizeof(sp)); 612 bzero(&sm, sizeof(sm)); 613 bzero(&dp, sizeof(dp)); 614 bzero(&dm, sizeof(dm)); 615 sp.sin_len = sm.sin_len = dp.sin_len = dm.sin_len = 616 sizeof(struct sockaddr_in); 617 sp.sin_family = sm.sin_family = dp.sin_family = 618 dm.sin_family = AF_INET; 619 sp.sin_addr = sc->g_src; 620 dp.sin_addr = sc->g_dst; 621 sm.sin_addr.s_addr = dm.sin_addr.s_addr = 622 INADDR_BROADCAST; 623#ifdef INET 624 sc->encap = encap_attach(AF_INET, sc->g_proto, 625 sintosa(&sp), sintosa(&sm), sintosa(&dp), 626 sintosa(&dm), (sc->g_proto == IPPROTO_GRE) ? 627 &in_gre_protosw : &in_mobile_protosw, sc); 628 if (sc->encap == NULL) 629 printf("%s: unable to attach encap\n", 630 if_name(GRE2IFP(sc))); 631#endif 632 if (sc->route.ro_rt != 0) /* free old route */ 633 RTFREE(sc->route.ro_rt); 634 if (gre_compute_route(sc) == 0) 635 ifp->if_drv_flags |= IFF_DRV_RUNNING; 636 else 637 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 638 } 639 break; 640 case GREGADDRS: 641 memset(&si, 0, sizeof(si)); 642 si.sin_family = AF_INET; 643 si.sin_len = sizeof(struct sockaddr_in); 644 si.sin_addr.s_addr = sc->g_src.s_addr; 645 sa = sintosa(&si); 646 ifr->ifr_addr = *sa; 647 break; 648 case GREGADDRD: 649 memset(&si, 0, sizeof(si)); 650 si.sin_family = AF_INET; 651 si.sin_len = sizeof(struct sockaddr_in); 652 si.sin_addr.s_addr = sc->g_dst.s_addr; 653 sa = sintosa(&si); 654 ifr->ifr_addr = *sa; 655 break; 656 case SIOCSIFPHYADDR: 657 /* 658 * XXXRW: Isn't this priv_check() redundant to the ifnet 659 * layer check? 660 */ 661 if ((error = priv_check(curthread, PRIV_NET_SETIFPHYS)) != 0) 662 break; 663 if (aifr->ifra_addr.sin_family != AF_INET || 664 aifr->ifra_dstaddr.sin_family != AF_INET) { 665 error = EAFNOSUPPORT; 666 break; 667 } 668 if (aifr->ifra_addr.sin_len != sizeof(si) || 669 aifr->ifra_dstaddr.sin_len != sizeof(si)) { 670 error = EINVAL; 671 break; 672 } 673 sc->g_src = aifr->ifra_addr.sin_addr; 674 sc->g_dst = aifr->ifra_dstaddr.sin_addr; 675 goto recompute; 676 case SIOCSLIFPHYADDR: 677 /* 678 * XXXRW: Isn't this priv_check() redundant to the ifnet 679 * layer check? 680 */ 681 if ((error = priv_check(curthread, PRIV_NET_SETIFPHYS)) != 0) 682 break; 683 if (lifr->addr.ss_family != AF_INET || 684 lifr->dstaddr.ss_family != AF_INET) { 685 error = EAFNOSUPPORT; 686 break; 687 } 688 if (lifr->addr.ss_len != sizeof(si) || 689 lifr->dstaddr.ss_len != sizeof(si)) { 690 error = EINVAL; 691 break; 692 } 693 sc->g_src = (satosin(&lifr->addr))->sin_addr; 694 sc->g_dst = 695 (satosin(&lifr->dstaddr))->sin_addr; 696 goto recompute; 697 case SIOCDIFPHYADDR: 698 /* 699 * XXXRW: Isn't this priv_check() redundant to the ifnet 700 * layer check? 701 */ 702 if ((error = priv_check(curthread, PRIV_NET_SETIFPHYS)) != 0) 703 break; 704 sc->g_src.s_addr = INADDR_ANY; 705 sc->g_dst.s_addr = INADDR_ANY; 706 goto recompute; 707 case SIOCGLIFPHYADDR: 708 if (sc->g_src.s_addr == INADDR_ANY || 709 sc->g_dst.s_addr == INADDR_ANY) { 710 error = EADDRNOTAVAIL; 711 break; 712 } 713 memset(&si, 0, sizeof(si)); 714 si.sin_family = AF_INET; 715 si.sin_len = sizeof(struct sockaddr_in); 716 si.sin_addr.s_addr = sc->g_src.s_addr; 717 memcpy(&lifr->addr, &si, sizeof(si)); 718 si.sin_addr.s_addr = sc->g_dst.s_addr; 719 memcpy(&lifr->dstaddr, &si, sizeof(si)); 720 break; 721 case SIOCGIFPSRCADDR: 722#ifdef INET6 723 case SIOCGIFPSRCADDR_IN6: 724#endif 725 if (sc->g_src.s_addr == INADDR_ANY) { 726 error = EADDRNOTAVAIL; 727 break; 728 } 729 memset(&si, 0, sizeof(si)); 730 si.sin_family = AF_INET; 731 si.sin_len = sizeof(struct sockaddr_in); 732 si.sin_addr.s_addr = sc->g_src.s_addr; 733 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr)); 734 break; 735 case SIOCGIFPDSTADDR: 736#ifdef INET6 737 case SIOCGIFPDSTADDR_IN6: 738#endif 739 if (sc->g_dst.s_addr == INADDR_ANY) { 740 error = EADDRNOTAVAIL; 741 break; 742 } 743 memset(&si, 0, sizeof(si)); 744 si.sin_family = AF_INET; 745 si.sin_len = sizeof(struct sockaddr_in); 746 si.sin_addr.s_addr = sc->g_dst.s_addr; 747 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr)); 748 break; 749 case GRESKEY: 750 error = priv_check(curthread, PRIV_NET_GRE); 751 if (error) 752 break; 753 error = copyin(ifr->ifr_data, &key, sizeof(key)); 754 if (error) 755 break; 756 /* adjust MTU for option header */ 757 if (key == 0 && sc->key != 0) /* clear */ 758 adj += sizeof(key); 759 else if (key != 0 && sc->key == 0) /* set */ 760 adj -= sizeof(key); 761 762 if (ifp->if_mtu + adj < 576) { 763 error = EINVAL; 764 break; 765 } 766 ifp->if_mtu += adj; 767 sc->key = key; 768 break; 769 case GREGKEY: 770 error = copyout(&sc->key, ifr->ifr_data, sizeof(sc->key)); 771 break; 772 773 default: 774 error = EINVAL; 775 break; 776 } 777 778 splx(s); 779 return (error); 780} 781 782/* 783 * computes a route to our destination that is not the one 784 * which would be taken by ip_output(), as this one will loop back to 785 * us. If the interface is p2p as a--->b, then a routing entry exists 786 * If we now send a packet to b (e.g. ping b), this will come down here 787 * gets src=a, dst=b tacked on and would from ip_output() sent back to 788 * if_gre. 789 * Goal here is to compute a route to b that is less specific than 790 * a-->b. We know that this one exists as in normal operation we have 791 * at least a default route which matches. 792 */ 793static int 794gre_compute_route(struct gre_softc *sc) 795{ 796 struct route *ro; 797 798 ro = &sc->route; 799 800 memset(ro, 0, sizeof(struct route)); 801 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst; 802 ro->ro_dst.sa_family = AF_INET; 803 ro->ro_dst.sa_len = sizeof(ro->ro_dst); 804 805 /* 806 * toggle last bit, so our interface is not found, but a less 807 * specific route. I'd rather like to specify a shorter mask, 808 * but this is not possible. Should work though. XXX 809 * XXX MRT Use a different FIB for the tunnel to solve this problem. 810 */ 811 if ((GRE2IFP(sc)->if_flags & IFF_LINK1) == 0) { 812 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr.s_addr ^= 813 htonl(0x01); 814 } 815 816#ifdef DIAGNOSTIC 817 printf("%s: searching for a route to %s", if_name(GRE2IFP(sc)), 818 inet_ntoa(((struct sockaddr_in *)&ro->ro_dst)->sin_addr)); 819#endif 820 821 rtalloc_fib(ro, sc->gre_fibnum); 822 823 /* 824 * check if this returned a route at all and this route is no 825 * recursion to ourself 826 */ 827 if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp->if_softc == sc) { 828#ifdef DIAGNOSTIC 829 if (ro->ro_rt == NULL) 830 printf(" - no route found!\n"); 831 else 832 printf(" - route loops back to ourself!\n"); 833#endif 834 return EADDRNOTAVAIL; 835 } 836 837 /* 838 * now change it back - else ip_output will just drop 839 * the route and search one to this interface ... 840 */ 841 if ((GRE2IFP(sc)->if_flags & IFF_LINK1) == 0) 842 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst; 843 844#ifdef DIAGNOSTIC 845 printf(", choosing %s with gateway %s", if_name(ro->ro_rt->rt_ifp), 846 inet_ntoa(((struct sockaddr_in *)(ro->ro_rt->rt_gateway))->sin_addr)); 847 printf("\n"); 848#endif 849 850 return 0; 851} 852 853/* 854 * do a checksum of a buffer - much like in_cksum, which operates on 855 * mbufs. 856 */ 857u_int16_t 858gre_in_cksum(u_int16_t *p, u_int len) 859{ 860 u_int32_t sum = 0; 861 int nwords = len >> 1; 862 863 while (nwords-- != 0) 864 sum += *p++; 865 866 if (len & 1) { 867 union { 868 u_short w; 869 u_char c[2]; 870 } u; 871 u.c[0] = *(u_char *)p; 872 u.c[1] = 0; 873 sum += u.w; 874 } 875 876 /* end-around-carry */ 877 sum = (sum >> 16) + (sum & 0xffff); 878 sum += (sum >> 16); 879 return (~sum); 880} 881 882static int 883gremodevent(module_t mod, int type, void *data) 884{ 885 886 switch (type) { 887 case MOD_LOAD: 888 greattach(); 889 break; 890 case MOD_UNLOAD: 891 if_clone_detach(&gre_cloner); 892 mtx_destroy(&gre_mtx); 893 break; 894 default: 895 return EOPNOTSUPP; 896 } 897 return 0; 898} 899 900static moduledata_t gre_mod = { 901 "if_gre", 902 gremodevent, 903 0 904}; 905 906DECLARE_MODULE(if_gre, gre_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 907MODULE_VERSION(if_gre, 1); 908