if_gre.c revision 164033
1/* $NetBSD: if_gre.c,v 1.49 2003/12/11 00:22:29 itojun Exp $ */ 2/* $FreeBSD: head/sys/net/if_gre.c 164033 2006-11-06 13:42:10Z 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/protosw.h> 62#include <sys/socket.h> 63#include <sys/sockio.h> 64#include <sys/sysctl.h> 65#include <sys/systm.h> 66 67#include <net/ethernet.h> 68#include <net/if.h> 69#include <net/if_clone.h> 70#include <net/if_types.h> 71#include <net/route.h> 72 73#ifdef INET 74#include <netinet/in.h> 75#include <netinet/in_systm.h> 76#include <netinet/in_var.h> 77#include <netinet/ip.h> 78#include <netinet/ip_gre.h> 79#include <netinet/ip_var.h> 80#include <netinet/ip_encap.h> 81#else 82#error "Huh? if_gre without inet?" 83#endif 84 85#include <net/bpf.h> 86 87#include <net/if_gre.h> 88 89/* 90 * It is not easy to calculate the right value for a GRE MTU. 91 * We leave this task to the admin and use the same default that 92 * other vendors use. 93 */ 94#define GREMTU 1476 95 96#define GRENAME "gre" 97 98/* 99 * gre_mtx protects all global variables in if_gre.c. 100 * XXX: gre_softc data not protected yet. 101 */ 102struct mtx gre_mtx; 103static MALLOC_DEFINE(M_GRE, GRENAME, "Generic Routing Encapsulation"); 104 105struct gre_softc_head gre_softc_list; 106 107static int gre_clone_create(struct if_clone *, int, caddr_t); 108static void gre_clone_destroy(struct ifnet *); 109static int gre_ioctl(struct ifnet *, u_long, caddr_t); 110static int gre_output(struct ifnet *, struct mbuf *, struct sockaddr *, 111 struct rtentry *rt); 112 113IFC_SIMPLE_DECLARE(gre, 0); 114 115static int gre_compute_route(struct gre_softc *sc); 116 117static void greattach(void); 118 119#ifdef INET 120extern struct domain inetdomain; 121static const struct protosw in_gre_protosw = { 122 .pr_type = SOCK_RAW, 123 .pr_domain = &inetdomain, 124 .pr_protocol = IPPROTO_GRE, 125 .pr_flags = PR_ATOMIC|PR_ADDR, 126 .pr_input = gre_input, 127 .pr_output = (pr_output_t *)rip_output, 128 .pr_ctlinput = rip_ctlinput, 129 .pr_ctloutput = rip_ctloutput, 130 .pr_usrreqs = &rip_usrreqs 131}; 132static const struct protosw in_mobile_protosw = { 133 .pr_type = SOCK_RAW, 134 .pr_domain = &inetdomain, 135 .pr_protocol = IPPROTO_MOBILE, 136 .pr_flags = PR_ATOMIC|PR_ADDR, 137 .pr_input = gre_mobile_input, 138 .pr_output = (pr_output_t *)rip_output, 139 .pr_ctlinput = rip_ctlinput, 140 .pr_ctloutput = rip_ctloutput, 141 .pr_usrreqs = &rip_usrreqs 142}; 143#endif 144 145SYSCTL_DECL(_net_link); 146SYSCTL_NODE(_net_link, IFT_TUNNEL, gre, CTLFLAG_RW, 0, 147 "Generic Routing Encapsulation"); 148#ifndef MAX_GRE_NEST 149/* 150 * This macro controls the default upper limitation on nesting of gre tunnels. 151 * Since, setting a large value to this macro with a careless configuration 152 * may introduce system crash, we don't allow any nestings by default. 153 * If you need to configure nested gre tunnels, you can define this macro 154 * in your kernel configuration file. However, if you do so, please be 155 * careful to configure the tunnels so that it won't make a loop. 156 */ 157#define MAX_GRE_NEST 1 158#endif 159static int max_gre_nesting = MAX_GRE_NEST; 160SYSCTL_INT(_net_link_gre, OID_AUTO, max_nesting, CTLFLAG_RW, 161 &max_gre_nesting, 0, "Max nested tunnels"); 162 163/* ARGSUSED */ 164static void 165greattach(void) 166{ 167 168 mtx_init(&gre_mtx, "gre_mtx", NULL, MTX_DEF); 169 LIST_INIT(&gre_softc_list); 170 if_clone_attach(&gre_cloner); 171} 172 173static int 174gre_clone_create(ifc, unit, params) 175 struct if_clone *ifc; 176 int unit; 177 caddr_t params; 178{ 179 struct gre_softc *sc; 180 181 sc = malloc(sizeof(struct gre_softc), M_GRE, M_WAITOK | M_ZERO); 182 183 GRE2IFP(sc) = if_alloc(IFT_TUNNEL); 184 if (GRE2IFP(sc) == NULL) { 185 free(sc, M_GRE); 186 return (ENOSPC); 187 } 188 189 GRE2IFP(sc)->if_softc = sc; 190 if_initname(GRE2IFP(sc), ifc->ifc_name, unit); 191 192 GRE2IFP(sc)->if_snd.ifq_maxlen = IFQ_MAXLEN; 193 GRE2IFP(sc)->if_addrlen = 0; 194 GRE2IFP(sc)->if_hdrlen = 24; /* IP + GRE */ 195 GRE2IFP(sc)->if_mtu = GREMTU; 196 GRE2IFP(sc)->if_flags = IFF_POINTOPOINT|IFF_MULTICAST; 197 GRE2IFP(sc)->if_output = gre_output; 198 GRE2IFP(sc)->if_ioctl = gre_ioctl; 199 sc->g_dst.s_addr = sc->g_src.s_addr = INADDR_ANY; 200 sc->g_proto = IPPROTO_GRE; 201 GRE2IFP(sc)->if_flags |= IFF_LINK0; 202 sc->encap = NULL; 203 sc->called = 0; 204 sc->wccp_ver = WCCP_V1; 205 if_attach(GRE2IFP(sc)); 206 bpfattach(GRE2IFP(sc), DLT_NULL, sizeof(u_int32_t)); 207 mtx_lock(&gre_mtx); 208 LIST_INSERT_HEAD(&gre_softc_list, sc, sc_list); 209 mtx_unlock(&gre_mtx); 210 return (0); 211} 212 213static void 214gre_clone_destroy(ifp) 215 struct ifnet *ifp; 216{ 217 struct gre_softc *sc = ifp->if_softc; 218 219 mtx_lock(&gre_mtx); 220 LIST_REMOVE(sc, sc_list); 221 mtx_unlock(&gre_mtx); 222 223#ifdef INET 224 if (sc->encap != NULL) 225 encap_detach(sc->encap); 226#endif 227 bpfdetach(ifp); 228 if_detach(ifp); 229 if_free(ifp); 230 free(sc, M_GRE); 231} 232 233/* 234 * The output routine. Takes a packet and encapsulates it in the protocol 235 * given by sc->g_proto. See also RFC 1701 and RFC 2004 236 */ 237static int 238gre_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 239 struct rtentry *rt) 240{ 241 int error = 0; 242 struct gre_softc *sc = ifp->if_softc; 243 struct greip *gh; 244 struct ip *ip; 245 u_short ip_id = 0; 246 uint8_t ip_tos = 0; 247 u_int16_t etype = 0; 248 struct mobile_h mob_h; 249 u_int32_t af; 250 251 /* 252 * gre may cause infinite recursion calls when misconfigured. 253 * We'll prevent this by introducing upper limit. 254 */ 255 if (++(sc->called) > max_gre_nesting) { 256 printf("%s: gre_output: recursively called too many " 257 "times(%d)\n", if_name(GRE2IFP(sc)), sc->called); 258 m_freem(m); 259 error = EIO; /* is there better errno? */ 260 goto end; 261 } 262 263 if (!((ifp->if_flags & IFF_UP) && 264 (ifp->if_drv_flags & IFF_DRV_RUNNING)) || 265 sc->g_src.s_addr == INADDR_ANY || sc->g_dst.s_addr == INADDR_ANY) { 266 m_freem(m); 267 error = ENETDOWN; 268 goto end; 269 } 270 271 gh = NULL; 272 ip = NULL; 273 274 /* BPF writes need to be handled specially. */ 275 if (dst->sa_family == AF_UNSPEC) { 276 bcopy(dst->sa_data, &af, sizeof(af)); 277 dst->sa_family = af; 278 } 279 280 if (bpf_peers_present(ifp->if_bpf)) { 281 af = dst->sa_family; 282 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 283 } 284 285 m->m_flags &= ~(M_BCAST|M_MCAST); 286 287 if (sc->g_proto == IPPROTO_MOBILE) { 288 if (dst->sa_family == AF_INET) { 289 struct mbuf *m0; 290 int msiz; 291 292 ip = mtod(m, struct ip *); 293 294 /* 295 * RFC2004 specifies that fragmented diagrams shouldn't 296 * be encapsulated. 297 */ 298 if (ip->ip_off & (IP_MF | IP_OFFMASK)) { 299 _IF_DROP(&ifp->if_snd); 300 m_freem(m); 301 error = EINVAL; /* is there better errno? */ 302 goto end; 303 } 304 memset(&mob_h, 0, MOB_H_SIZ_L); 305 mob_h.proto = (ip->ip_p) << 8; 306 mob_h.odst = ip->ip_dst.s_addr; 307 ip->ip_dst.s_addr = sc->g_dst.s_addr; 308 309 /* 310 * If the packet comes from our host, we only change 311 * the destination address in the IP header. 312 * Else we also need to save and change the source 313 */ 314 if (in_hosteq(ip->ip_src, sc->g_src)) { 315 msiz = MOB_H_SIZ_S; 316 } else { 317 mob_h.proto |= MOB_H_SBIT; 318 mob_h.osrc = ip->ip_src.s_addr; 319 ip->ip_src.s_addr = sc->g_src.s_addr; 320 msiz = MOB_H_SIZ_L; 321 } 322 mob_h.proto = htons(mob_h.proto); 323 mob_h.hcrc = gre_in_cksum((u_int16_t *)&mob_h, msiz); 324 325 if ((m->m_data - msiz) < m->m_pktdat) { 326 /* need new mbuf */ 327 MGETHDR(m0, M_DONTWAIT, MT_DATA); 328 if (m0 == NULL) { 329 _IF_DROP(&ifp->if_snd); 330 m_freem(m); 331 error = ENOBUFS; 332 goto end; 333 } 334 m0->m_next = m; 335 m->m_data += sizeof(struct ip); 336 m->m_len -= sizeof(struct ip); 337 m0->m_pkthdr.len = m->m_pkthdr.len + msiz; 338 m0->m_len = msiz + sizeof(struct ip); 339 m0->m_data += max_linkhdr; 340 memcpy(mtod(m0, caddr_t), (caddr_t)ip, 341 sizeof(struct ip)); 342 m = m0; 343 } else { /* we have some space left in the old one */ 344 m->m_data -= msiz; 345 m->m_len += msiz; 346 m->m_pkthdr.len += msiz; 347 bcopy(ip, mtod(m, caddr_t), 348 sizeof(struct ip)); 349 } 350 ip = mtod(m, struct ip *); 351 memcpy((caddr_t)(ip + 1), &mob_h, (unsigned)msiz); 352 ip->ip_len = ntohs(ip->ip_len) + msiz; 353 } else { /* AF_INET */ 354 _IF_DROP(&ifp->if_snd); 355 m_freem(m); 356 error = EINVAL; 357 goto end; 358 } 359 } else if (sc->g_proto == IPPROTO_GRE) { 360 switch (dst->sa_family) { 361 case AF_INET: 362 ip = mtod(m, struct ip *); 363 ip_tos = ip->ip_tos; 364 ip_id = ip->ip_id; 365 etype = ETHERTYPE_IP; 366 break; 367#ifdef INET6 368 case AF_INET6: 369 ip_id = ip_newid(); 370 etype = ETHERTYPE_IPV6; 371 break; 372#endif 373#ifdef NETATALK 374 case AF_APPLETALK: 375 etype = ETHERTYPE_ATALK; 376 break; 377#endif 378 default: 379 _IF_DROP(&ifp->if_snd); 380 m_freem(m); 381 error = EAFNOSUPPORT; 382 goto end; 383 } 384 M_PREPEND(m, sizeof(struct greip), M_DONTWAIT); 385 } else { 386 _IF_DROP(&ifp->if_snd); 387 m_freem(m); 388 error = EINVAL; 389 goto end; 390 } 391 392 if (m == NULL) { /* mbuf allocation failed */ 393 _IF_DROP(&ifp->if_snd); 394 error = ENOBUFS; 395 goto end; 396 } 397 398 gh = mtod(m, struct greip *); 399 if (sc->g_proto == IPPROTO_GRE) { 400 /* we don't have any GRE flags for now */ 401 memset((void *)gh, 0, sizeof(struct greip)); 402 gh->gi_ptype = htons(etype); 403 } 404 405 gh->gi_pr = sc->g_proto; 406 if (sc->g_proto != IPPROTO_MOBILE) { 407 gh->gi_src = sc->g_src; 408 gh->gi_dst = sc->g_dst; 409 ((struct ip*)gh)->ip_v = IPPROTO_IPV4; 410 ((struct ip*)gh)->ip_hl = (sizeof(struct ip)) >> 2; 411 ((struct ip*)gh)->ip_ttl = GRE_TTL; 412 ((struct ip*)gh)->ip_tos = ip_tos; 413 ((struct ip*)gh)->ip_id = ip_id; 414 gh->gi_len = m->m_pkthdr.len; 415 } 416 417 ifp->if_opackets++; 418 ifp->if_obytes += m->m_pkthdr.len; 419 /* 420 * Send it off and with IP_FORWARD flag to prevent it from 421 * overwriting the ip_id again. ip_id is already set to the 422 * ip_id of the encapsulated packet. 423 */ 424 error = ip_output(m, NULL, &sc->route, IP_FORWARDING, 425 (struct ip_moptions *)NULL, (struct inpcb *)NULL); 426 end: 427 sc->called = 0; 428 if (error) 429 ifp->if_oerrors++; 430 return (error); 431} 432 433static int 434gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 435{ 436 struct ifreq *ifr = (struct ifreq *)data; 437 struct if_laddrreq *lifr = (struct if_laddrreq *)data; 438 struct in_aliasreq *aifr = (struct in_aliasreq *)data; 439 struct gre_softc *sc = ifp->if_softc; 440 int s; 441 struct sockaddr_in si; 442 struct sockaddr *sa = NULL; 443 int error; 444 struct sockaddr_in sp, sm, dp, dm; 445 446 error = 0; 447 448 s = splnet(); 449 switch (cmd) { 450 case SIOCSIFADDR: 451 ifp->if_flags |= IFF_UP; 452 break; 453 case SIOCSIFDSTADDR: 454 break; 455 case SIOCSIFFLAGS: 456 /* 457 * XXXRW: Isn't this suser() redundant to the ifnet layer 458 * check? 459 */ 460 if ((error = priv_check(curthread, PRIV_NET_SETIFFLAGS)) != 0) 461 break; 462 if ((ifr->ifr_flags & IFF_LINK0) != 0) 463 sc->g_proto = IPPROTO_GRE; 464 else 465 sc->g_proto = IPPROTO_MOBILE; 466 if ((ifr->ifr_flags & IFF_LINK2) != 0) 467 sc->wccp_ver = WCCP_V2; 468 else 469 sc->wccp_ver = WCCP_V1; 470 goto recompute; 471 case SIOCSIFMTU: 472 /* 473 * XXXRW: Isn't this suser() redundant to the ifnet layer 474 * check? 475 */ 476 if ((error = priv_check(curthread, PRIV_NET_SETIFMTU)) != 0) 477 break; 478 if (ifr->ifr_mtu < 576) { 479 error = EINVAL; 480 break; 481 } 482 ifp->if_mtu = ifr->ifr_mtu; 483 break; 484 case SIOCGIFMTU: 485 ifr->ifr_mtu = GRE2IFP(sc)->if_mtu; 486 break; 487 case SIOCADDMULTI: 488 /* 489 * XXXRW: Isn't this suser() redundant to the ifnet layer 490 * check? 491 */ 492 if ((error = priv_check(curthread, PRIV_NET_ADDMULTI)) != 0) 493 break; 494 if (ifr == 0) { 495 error = EAFNOSUPPORT; 496 break; 497 } 498 switch (ifr->ifr_addr.sa_family) { 499#ifdef INET 500 case AF_INET: 501 break; 502#endif 503#ifdef INET6 504 case AF_INET6: 505 break; 506#endif 507 default: 508 error = EAFNOSUPPORT; 509 break; 510 } 511 break; 512 case SIOCDELMULTI: 513 /* 514 * XXXRW: Isn't this suser() redundant to the ifnet layer 515 * check? 516 */ 517 if ((error = priv_check(curthread, PRIV_NET_DELIFGROUP)) != 0) 518 break; 519 if (ifr == 0) { 520 error = EAFNOSUPPORT; 521 break; 522 } 523 switch (ifr->ifr_addr.sa_family) { 524#ifdef INET 525 case AF_INET: 526 break; 527#endif 528#ifdef INET6 529 case AF_INET6: 530 break; 531#endif 532 default: 533 error = EAFNOSUPPORT; 534 break; 535 } 536 break; 537 case GRESPROTO: 538 /* 539 * XXXRW: Isn't this suser() redundant to the ifnet layer 540 * check? 541 */ 542 if ((error = priv_check(curthread, PRIV_NET_GRE)) != 0) 543 break; 544 sc->g_proto = ifr->ifr_flags; 545 switch (sc->g_proto) { 546 case IPPROTO_GRE: 547 ifp->if_flags |= IFF_LINK0; 548 break; 549 case IPPROTO_MOBILE: 550 ifp->if_flags &= ~IFF_LINK0; 551 break; 552 default: 553 error = EPROTONOSUPPORT; 554 break; 555 } 556 goto recompute; 557 case GREGPROTO: 558 ifr->ifr_flags = sc->g_proto; 559 break; 560 case GRESADDRS: 561 case GRESADDRD: 562 error = priv_check(curthread, PRIV_NET_GRE); 563 if (error) 564 return (error); 565 /* 566 * set tunnel endpoints, compute a less specific route 567 * to the remote end and mark if as up 568 */ 569 sa = &ifr->ifr_addr; 570 if (cmd == GRESADDRS) 571 sc->g_src = (satosin(sa))->sin_addr; 572 if (cmd == GRESADDRD) 573 sc->g_dst = (satosin(sa))->sin_addr; 574 recompute: 575#ifdef INET 576 if (sc->encap != NULL) { 577 encap_detach(sc->encap); 578 sc->encap = NULL; 579 } 580#endif 581 if ((sc->g_src.s_addr != INADDR_ANY) && 582 (sc->g_dst.s_addr != INADDR_ANY)) { 583 bzero(&sp, sizeof(sp)); 584 bzero(&sm, sizeof(sm)); 585 bzero(&dp, sizeof(dp)); 586 bzero(&dm, sizeof(dm)); 587 sp.sin_len = sm.sin_len = dp.sin_len = dm.sin_len = 588 sizeof(struct sockaddr_in); 589 sp.sin_family = sm.sin_family = dp.sin_family = 590 dm.sin_family = AF_INET; 591 sp.sin_addr = sc->g_src; 592 dp.sin_addr = sc->g_dst; 593 sm.sin_addr.s_addr = dm.sin_addr.s_addr = 594 INADDR_BROADCAST; 595#ifdef INET 596 sc->encap = encap_attach(AF_INET, sc->g_proto, 597 sintosa(&sp), sintosa(&sm), sintosa(&dp), 598 sintosa(&dm), (sc->g_proto == IPPROTO_GRE) ? 599 &in_gre_protosw : &in_mobile_protosw, sc); 600 if (sc->encap == NULL) 601 printf("%s: unable to attach encap\n", 602 if_name(GRE2IFP(sc))); 603#endif 604 if (sc->route.ro_rt != 0) /* free old route */ 605 RTFREE(sc->route.ro_rt); 606 if (gre_compute_route(sc) == 0) 607 ifp->if_drv_flags |= IFF_DRV_RUNNING; 608 else 609 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 610 } 611 break; 612 case GREGADDRS: 613 memset(&si, 0, sizeof(si)); 614 si.sin_family = AF_INET; 615 si.sin_len = sizeof(struct sockaddr_in); 616 si.sin_addr.s_addr = sc->g_src.s_addr; 617 sa = sintosa(&si); 618 ifr->ifr_addr = *sa; 619 break; 620 case GREGADDRD: 621 memset(&si, 0, sizeof(si)); 622 si.sin_family = AF_INET; 623 si.sin_len = sizeof(struct sockaddr_in); 624 si.sin_addr.s_addr = sc->g_dst.s_addr; 625 sa = sintosa(&si); 626 ifr->ifr_addr = *sa; 627 break; 628 case SIOCSIFPHYADDR: 629 /* 630 * XXXRW: Isn't this suser() redundant to the ifnet layer 631 * check? 632 */ 633 if ((error = priv_check(curthread, PRIV_NET_SETIFPHYS)) != 0) 634 break; 635 if (aifr->ifra_addr.sin_family != AF_INET || 636 aifr->ifra_dstaddr.sin_family != AF_INET) { 637 error = EAFNOSUPPORT; 638 break; 639 } 640 if (aifr->ifra_addr.sin_len != sizeof(si) || 641 aifr->ifra_dstaddr.sin_len != sizeof(si)) { 642 error = EINVAL; 643 break; 644 } 645 sc->g_src = aifr->ifra_addr.sin_addr; 646 sc->g_dst = aifr->ifra_dstaddr.sin_addr; 647 goto recompute; 648 case SIOCSLIFPHYADDR: 649 /* 650 * XXXRW: Isn't this suser() redundant to the ifnet layer 651 * check? 652 */ 653 if ((error = priv_check(curthread, PRIV_NET_SETIFPHYS)) != 0) 654 break; 655 if (lifr->addr.ss_family != AF_INET || 656 lifr->dstaddr.ss_family != AF_INET) { 657 error = EAFNOSUPPORT; 658 break; 659 } 660 if (lifr->addr.ss_len != sizeof(si) || 661 lifr->dstaddr.ss_len != sizeof(si)) { 662 error = EINVAL; 663 break; 664 } 665 sc->g_src = (satosin(&lifr->addr))->sin_addr; 666 sc->g_dst = 667 (satosin(&lifr->dstaddr))->sin_addr; 668 goto recompute; 669 case SIOCDIFPHYADDR: 670 /* 671 * XXXRW: Isn't this suser() redundant to the ifnet layer 672 * check? 673 */ 674 if ((error = priv_check(curthread, PRIV_NET_SETIFPHYS)) != 0) 675 break; 676 sc->g_src.s_addr = INADDR_ANY; 677 sc->g_dst.s_addr = INADDR_ANY; 678 goto recompute; 679 case SIOCGLIFPHYADDR: 680 if (sc->g_src.s_addr == INADDR_ANY || 681 sc->g_dst.s_addr == INADDR_ANY) { 682 error = EADDRNOTAVAIL; 683 break; 684 } 685 memset(&si, 0, sizeof(si)); 686 si.sin_family = AF_INET; 687 si.sin_len = sizeof(struct sockaddr_in); 688 si.sin_addr.s_addr = sc->g_src.s_addr; 689 memcpy(&lifr->addr, &si, sizeof(si)); 690 si.sin_addr.s_addr = sc->g_dst.s_addr; 691 memcpy(&lifr->dstaddr, &si, sizeof(si)); 692 break; 693 case SIOCGIFPSRCADDR: 694#ifdef INET6 695 case SIOCGIFPSRCADDR_IN6: 696#endif 697 if (sc->g_src.s_addr == INADDR_ANY) { 698 error = EADDRNOTAVAIL; 699 break; 700 } 701 memset(&si, 0, sizeof(si)); 702 si.sin_family = AF_INET; 703 si.sin_len = sizeof(struct sockaddr_in); 704 si.sin_addr.s_addr = sc->g_src.s_addr; 705 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr)); 706 break; 707 case SIOCGIFPDSTADDR: 708#ifdef INET6 709 case SIOCGIFPDSTADDR_IN6: 710#endif 711 if (sc->g_dst.s_addr == INADDR_ANY) { 712 error = EADDRNOTAVAIL; 713 break; 714 } 715 memset(&si, 0, sizeof(si)); 716 si.sin_family = AF_INET; 717 si.sin_len = sizeof(struct sockaddr_in); 718 si.sin_addr.s_addr = sc->g_dst.s_addr; 719 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr)); 720 break; 721 default: 722 error = EINVAL; 723 break; 724 } 725 726 splx(s); 727 return (error); 728} 729 730/* 731 * computes a route to our destination that is not the one 732 * which would be taken by ip_output(), as this one will loop back to 733 * us. If the interface is p2p as a--->b, then a routing entry exists 734 * If we now send a packet to b (e.g. ping b), this will come down here 735 * gets src=a, dst=b tacked on and would from ip_output() sent back to 736 * if_gre. 737 * Goal here is to compute a route to b that is less specific than 738 * a-->b. We know that this one exists as in normal operation we have 739 * at least a default route which matches. 740 */ 741static int 742gre_compute_route(struct gre_softc *sc) 743{ 744 struct route *ro; 745 u_int32_t a, b, c; 746 747 ro = &sc->route; 748 749 memset(ro, 0, sizeof(struct route)); 750 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst; 751 ro->ro_dst.sa_family = AF_INET; 752 ro->ro_dst.sa_len = sizeof(ro->ro_dst); 753 754 /* 755 * toggle last bit, so our interface is not found, but a less 756 * specific route. I'd rather like to specify a shorter mask, 757 * but this is not possible. Should work though. XXX 758 * there is a simpler way ... 759 */ 760 if ((GRE2IFP(sc)->if_flags & IFF_LINK1) == 0) { 761 a = ntohl(sc->g_dst.s_addr); 762 b = a & 0x01; 763 c = a & 0xfffffffe; 764 b = b ^ 0x01; 765 a = b | c; 766 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr.s_addr 767 = htonl(a); 768 } 769 770#ifdef DIAGNOSTIC 771 printf("%s: searching for a route to %s", if_name(GRE2IFP(sc)), 772 inet_ntoa(((struct sockaddr_in *)&ro->ro_dst)->sin_addr)); 773#endif 774 775 rtalloc(ro); 776 777 /* 778 * check if this returned a route at all and this route is no 779 * recursion to ourself 780 */ 781 if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp->if_softc == sc) { 782#ifdef DIAGNOSTIC 783 if (ro->ro_rt == NULL) 784 printf(" - no route found!\n"); 785 else 786 printf(" - route loops back to ourself!\n"); 787#endif 788 return EADDRNOTAVAIL; 789 } 790 791 /* 792 * now change it back - else ip_output will just drop 793 * the route and search one to this interface ... 794 */ 795 if ((GRE2IFP(sc)->if_flags & IFF_LINK1) == 0) 796 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst; 797 798#ifdef DIAGNOSTIC 799 printf(", choosing %s with gateway %s", if_name(ro->ro_rt->rt_ifp), 800 inet_ntoa(((struct sockaddr_in *)(ro->ro_rt->rt_gateway))->sin_addr)); 801 printf("\n"); 802#endif 803 804 return 0; 805} 806 807/* 808 * do a checksum of a buffer - much like in_cksum, which operates on 809 * mbufs. 810 */ 811u_int16_t 812gre_in_cksum(u_int16_t *p, u_int len) 813{ 814 u_int32_t sum = 0; 815 int nwords = len >> 1; 816 817 while (nwords-- != 0) 818 sum += *p++; 819 820 if (len & 1) { 821 union { 822 u_short w; 823 u_char c[2]; 824 } u; 825 u.c[0] = *(u_char *)p; 826 u.c[1] = 0; 827 sum += u.w; 828 } 829 830 /* end-around-carry */ 831 sum = (sum >> 16) + (sum & 0xffff); 832 sum += (sum >> 16); 833 return (~sum); 834} 835 836static int 837gremodevent(module_t mod, int type, void *data) 838{ 839 840 switch (type) { 841 case MOD_LOAD: 842 greattach(); 843 break; 844 case MOD_UNLOAD: 845 if_clone_detach(&gre_cloner); 846 mtx_destroy(&gre_mtx); 847 break; 848 default: 849 return EOPNOTSUPP; 850 } 851 return 0; 852} 853 854static moduledata_t gre_mod = { 855 "if_gre", 856 gremodevent, 857 0 858}; 859 860DECLARE_MODULE(if_gre, gre_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 861MODULE_VERSION(if_gre, 1); 862