if_gre.c revision 219206
1/* $NetBSD: if_gre.c,v 1.49 2003/12/11 00:22:29 itojun Exp $ */ 2/* $FreeBSD: head/sys/net/if_gre.c 219206 2011-03-02 21:39:08Z bz $ */ 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 * 22 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 23 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 24 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 25 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 26 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 27 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 28 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 29 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 30 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 31 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 32 * POSSIBILITY OF SUCH DAMAGE. 33 */ 34 35/* 36 * Encapsulate L3 protocols into IP 37 * See RFC 2784 (successor of RFC 1701 and 1702) for more details. 38 * If_gre is compatible with Cisco GRE tunnels, so you can 39 * have a NetBSD box as the other end of a tunnel interface of a Cisco 40 * router. See gre(4) for more details. 41 * Also supported: IP in IP encaps (proto 55) as of RFC 2004 42 */ 43 44#include "opt_atalk.h" 45#include "opt_inet.h" 46#include "opt_inet6.h" 47 48#include <sys/param.h> 49#include <sys/jail.h> 50#include <sys/kernel.h> 51#include <sys/malloc.h> 52#include <sys/module.h> 53#include <sys/mbuf.h> 54#include <sys/priv.h> 55#include <sys/proc.h> 56#include <sys/protosw.h> 57#include <sys/socket.h> 58#include <sys/sockio.h> 59#include <sys/sysctl.h> 60#include <sys/systm.h> 61 62#include <net/ethernet.h> 63#include <net/if.h> 64#include <net/if_clone.h> 65#include <net/if_types.h> 66#include <net/route.h> 67#include <net/vnet.h> 68 69#ifdef INET 70#include <netinet/in.h> 71#include <netinet/in_systm.h> 72#include <netinet/in_var.h> 73#include <netinet/ip.h> 74#include <netinet/ip_gre.h> 75#include <netinet/ip_var.h> 76#include <netinet/ip_encap.h> 77#else 78#error "Huh? if_gre without inet?" 79#endif 80 81#include <net/bpf.h> 82 83#include <net/if_gre.h> 84 85/* 86 * It is not easy to calculate the right value for a GRE MTU. 87 * We leave this task to the admin and use the same default that 88 * other vendors use. 89 */ 90#define GREMTU 1476 91 92#define GRENAME "gre" 93 94/* 95 * gre_mtx protects all global variables in if_gre.c. 96 * XXX: gre_softc data not protected yet. 97 */ 98struct mtx gre_mtx; 99static MALLOC_DEFINE(M_GRE, GRENAME, "Generic Routing Encapsulation"); 100 101struct gre_softc_head gre_softc_list; 102 103static int gre_clone_create(struct if_clone *, int, caddr_t); 104static void gre_clone_destroy(struct ifnet *); 105static int gre_ioctl(struct ifnet *, u_long, caddr_t); 106static int gre_output(struct ifnet *, struct mbuf *, struct sockaddr *, 107 struct route *ro); 108 109IFC_SIMPLE_DECLARE(gre, 0); 110 111static int gre_compute_route(struct gre_softc *sc); 112 113static void greattach(void); 114 115#ifdef INET 116extern struct domain inetdomain; 117static const struct protosw in_gre_protosw = { 118 .pr_type = SOCK_RAW, 119 .pr_domain = &inetdomain, 120 .pr_protocol = IPPROTO_GRE, 121 .pr_flags = PR_ATOMIC|PR_ADDR, 122 .pr_input = gre_input, 123 .pr_output = (pr_output_t *)rip_output, 124 .pr_ctlinput = rip_ctlinput, 125 .pr_ctloutput = rip_ctloutput, 126 .pr_usrreqs = &rip_usrreqs 127}; 128static const struct protosw in_mobile_protosw = { 129 .pr_type = SOCK_RAW, 130 .pr_domain = &inetdomain, 131 .pr_protocol = IPPROTO_MOBILE, 132 .pr_flags = PR_ATOMIC|PR_ADDR, 133 .pr_input = gre_mobile_input, 134 .pr_output = (pr_output_t *)rip_output, 135 .pr_ctlinput = rip_ctlinput, 136 .pr_ctloutput = rip_ctloutput, 137 .pr_usrreqs = &rip_usrreqs 138}; 139#endif 140 141SYSCTL_DECL(_net_link); 142SYSCTL_NODE(_net_link, IFT_TUNNEL, gre, CTLFLAG_RW, 0, 143 "Generic Routing Encapsulation"); 144#ifndef MAX_GRE_NEST 145/* 146 * This macro controls the default upper limitation on nesting of gre tunnels. 147 * Since, setting a large value to this macro with a careless configuration 148 * may introduce system crash, we don't allow any nestings by default. 149 * If you need to configure nested gre tunnels, you can define this macro 150 * in your kernel configuration file. However, if you do so, please be 151 * careful to configure the tunnels so that it won't make a loop. 152 */ 153#define MAX_GRE_NEST 1 154#endif 155static int max_gre_nesting = MAX_GRE_NEST; 156SYSCTL_INT(_net_link_gre, OID_AUTO, max_nesting, CTLFLAG_RW, 157 &max_gre_nesting, 0, "Max nested tunnels"); 158 159/* ARGSUSED */ 160static void 161greattach(void) 162{ 163 164 mtx_init(&gre_mtx, "gre_mtx", NULL, MTX_DEF); 165 LIST_INIT(&gre_softc_list); 166 if_clone_attach(&gre_cloner); 167} 168 169static int 170gre_clone_create(ifc, unit, params) 171 struct if_clone *ifc; 172 int unit; 173 caddr_t params; 174{ 175 struct gre_softc *sc; 176 177 sc = malloc(sizeof(struct gre_softc), M_GRE, M_WAITOK | M_ZERO); 178 179 GRE2IFP(sc) = if_alloc(IFT_TUNNEL); 180 if (GRE2IFP(sc) == NULL) { 181 free(sc, M_GRE); 182 return (ENOSPC); 183 } 184 185 GRE2IFP(sc)->if_softc = sc; 186 if_initname(GRE2IFP(sc), ifc->ifc_name, unit); 187 188 GRE2IFP(sc)->if_snd.ifq_maxlen = ifqmaxlen; 189 GRE2IFP(sc)->if_addrlen = 0; 190 GRE2IFP(sc)->if_hdrlen = 24; /* IP + GRE */ 191 GRE2IFP(sc)->if_mtu = GREMTU; 192 GRE2IFP(sc)->if_flags = IFF_POINTOPOINT|IFF_MULTICAST; 193 GRE2IFP(sc)->if_output = gre_output; 194 GRE2IFP(sc)->if_ioctl = gre_ioctl; 195 sc->g_dst.s_addr = sc->g_src.s_addr = INADDR_ANY; 196 sc->g_proto = IPPROTO_GRE; 197 GRE2IFP(sc)->if_flags |= IFF_LINK0; 198 sc->encap = NULL; 199 sc->called = 0; 200 sc->gre_fibnum = curthread->td_proc->p_fibnum; 201 sc->wccp_ver = WCCP_V1; 202 sc->key = 0; 203 if_attach(GRE2IFP(sc)); 204 bpfattach(GRE2IFP(sc), DLT_NULL, sizeof(u_int32_t)); 205 mtx_lock(&gre_mtx); 206 LIST_INSERT_HEAD(&gre_softc_list, sc, sc_list); 207 mtx_unlock(&gre_mtx); 208 return (0); 209} 210 211static void 212gre_clone_destroy(ifp) 213 struct ifnet *ifp; 214{ 215 struct gre_softc *sc = ifp->if_softc; 216 217 mtx_lock(&gre_mtx); 218 LIST_REMOVE(sc, sc_list); 219 mtx_unlock(&gre_mtx); 220 221#ifdef INET 222 if (sc->encap != NULL) 223 encap_detach(sc->encap); 224#endif 225 bpfdetach(ifp); 226 if_detach(ifp); 227 if_free(ifp); 228 free(sc, M_GRE); 229} 230 231/* 232 * The output routine. Takes a packet and encapsulates it in the protocol 233 * given by sc->g_proto. See also RFC 1701 and RFC 2004 234 */ 235static int 236gre_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 237 struct route *ro) 238{ 239 int error = 0; 240 struct gre_softc *sc = ifp->if_softc; 241 struct greip *gh; 242 struct ip *ip; 243 u_short gre_ip_id = 0; 244 uint8_t gre_ip_tos = 0; 245 u_int16_t etype = 0; 246 struct mobile_h mob_h; 247 u_int32_t af; 248 int extra = 0; 249 250 /* 251 * gre may cause infinite recursion calls when misconfigured. 252 * We'll prevent this by introducing upper limit. 253 */ 254 if (++(sc->called) > max_gre_nesting) { 255 printf("%s: gre_output: recursively called too many " 256 "times(%d)\n", if_name(GRE2IFP(sc)), sc->called); 257 m_freem(m); 258 error = EIO; /* is there better errno? */ 259 goto end; 260 } 261 262 if (!((ifp->if_flags & IFF_UP) && 263 (ifp->if_drv_flags & IFF_DRV_RUNNING)) || 264 sc->g_src.s_addr == INADDR_ANY || sc->g_dst.s_addr == INADDR_ANY) { 265 m_freem(m); 266 error = ENETDOWN; 267 goto end; 268 } 269 270 gh = NULL; 271 ip = NULL; 272 273 /* BPF writes need to be handled specially. */ 274 if (dst->sa_family == AF_UNSPEC) { 275 bcopy(dst->sa_data, &af, sizeof(af)); 276 dst->sa_family = af; 277 } 278 279 if (bpf_peers_present(ifp->if_bpf)) { 280 af = dst->sa_family; 281 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 282 } 283 284 m->m_flags &= ~(M_BCAST|M_MCAST); 285 286 if (sc->g_proto == IPPROTO_MOBILE) { 287 if (dst->sa_family == AF_INET) { 288 struct mbuf *m0; 289 int msiz; 290 291 ip = mtod(m, struct ip *); 292 293 /* 294 * RFC2004 specifies that fragmented diagrams shouldn't 295 * be encapsulated. 296 */ 297 if (ip->ip_off & (IP_MF | IP_OFFMASK)) { 298 _IF_DROP(&ifp->if_snd); 299 m_freem(m); 300 error = EINVAL; /* is there better errno? */ 301 goto end; 302 } 303 memset(&mob_h, 0, MOB_H_SIZ_L); 304 mob_h.proto = (ip->ip_p) << 8; 305 mob_h.odst = ip->ip_dst.s_addr; 306 ip->ip_dst.s_addr = sc->g_dst.s_addr; 307 308 /* 309 * If the packet comes from our host, we only change 310 * the destination address in the IP header. 311 * Else we also need to save and change the source 312 */ 313 if (in_hosteq(ip->ip_src, sc->g_src)) { 314 msiz = MOB_H_SIZ_S; 315 } else { 316 mob_h.proto |= MOB_H_SBIT; 317 mob_h.osrc = ip->ip_src.s_addr; 318 ip->ip_src.s_addr = sc->g_src.s_addr; 319 msiz = MOB_H_SIZ_L; 320 } 321 mob_h.proto = htons(mob_h.proto); 322 mob_h.hcrc = gre_in_cksum((u_int16_t *)&mob_h, msiz); 323 324 if ((m->m_data - msiz) < m->m_pktdat) { 325 /* need new mbuf */ 326 MGETHDR(m0, M_DONTWAIT, MT_DATA); 327 if (m0 == NULL) { 328 _IF_DROP(&ifp->if_snd); 329 m_freem(m); 330 error = ENOBUFS; 331 goto end; 332 } 333 m0->m_next = m; 334 m->m_data += sizeof(struct ip); 335 m->m_len -= sizeof(struct ip); 336 m0->m_pkthdr.len = m->m_pkthdr.len + msiz; 337 m0->m_len = msiz + sizeof(struct ip); 338 m0->m_data += max_linkhdr; 339 memcpy(mtod(m0, caddr_t), (caddr_t)ip, 340 sizeof(struct ip)); 341 m = m0; 342 } else { /* we have some space left in the old one */ 343 m->m_data -= msiz; 344 m->m_len += msiz; 345 m->m_pkthdr.len += msiz; 346 bcopy(ip, mtod(m, caddr_t), 347 sizeof(struct ip)); 348 } 349 ip = mtod(m, struct ip *); 350 memcpy((caddr_t)(ip + 1), &mob_h, (unsigned)msiz); 351 ip->ip_len = ntohs(ip->ip_len) + msiz; 352 } else { /* AF_INET */ 353 _IF_DROP(&ifp->if_snd); 354 m_freem(m); 355 error = EINVAL; 356 goto end; 357 } 358 } else if (sc->g_proto == IPPROTO_GRE) { 359 switch (dst->sa_family) { 360 case AF_INET: 361 ip = mtod(m, struct ip *); 362 gre_ip_tos = ip->ip_tos; 363 gre_ip_id = ip->ip_id; 364 if (sc->wccp_ver == WCCP_V2) { 365 extra = sizeof(uint32_t); 366 etype = WCCP_PROTOCOL_TYPE; 367 } else { 368 etype = ETHERTYPE_IP; 369 } 370 break; 371#ifdef INET6 372 case AF_INET6: 373 gre_ip_id = ip_newid(); 374 etype = ETHERTYPE_IPV6; 375 break; 376#endif 377#ifdef NETATALK 378 case AF_APPLETALK: 379 etype = ETHERTYPE_ATALK; 380 break; 381#endif 382 default: 383 _IF_DROP(&ifp->if_snd); 384 m_freem(m); 385 error = EAFNOSUPPORT; 386 goto end; 387 } 388 389 /* Reserve space for GRE header + optional GRE key */ 390 int hdrlen = sizeof(struct greip) + extra; 391 if (sc->key) 392 hdrlen += sizeof(uint32_t); 393 M_PREPEND(m, hdrlen, M_DONTWAIT); 394 } else { 395 _IF_DROP(&ifp->if_snd); 396 m_freem(m); 397 error = EINVAL; 398 goto end; 399 } 400 401 if (m == NULL) { /* mbuf allocation failed */ 402 _IF_DROP(&ifp->if_snd); 403 error = ENOBUFS; 404 goto end; 405 } 406 407 M_SETFIB(m, sc->gre_fibnum); /* The envelope may use a different FIB */ 408 409 gh = mtod(m, struct greip *); 410 if (sc->g_proto == IPPROTO_GRE) { 411 uint32_t *options = gh->gi_options; 412 413 memset((void *)gh, 0, sizeof(struct greip) + extra); 414 gh->gi_ptype = htons(etype); 415 gh->gi_flags = 0; 416 417 /* Add key option */ 418 if (sc->key) 419 { 420 gh->gi_flags |= htons(GRE_KP); 421 *(options++) = htonl(sc->key); 422 } 423 } 424 425 gh->gi_pr = sc->g_proto; 426 if (sc->g_proto != IPPROTO_MOBILE) { 427 gh->gi_src = sc->g_src; 428 gh->gi_dst = sc->g_dst; 429 ((struct ip*)gh)->ip_v = IPPROTO_IPV4; 430 ((struct ip*)gh)->ip_hl = (sizeof(struct ip)) >> 2; 431 ((struct ip*)gh)->ip_ttl = GRE_TTL; 432 ((struct ip*)gh)->ip_tos = gre_ip_tos; 433 ((struct ip*)gh)->ip_id = gre_ip_id; 434 gh->gi_len = m->m_pkthdr.len; 435 } 436 437 ifp->if_opackets++; 438 ifp->if_obytes += m->m_pkthdr.len; 439 /* 440 * Send it off and with IP_FORWARD flag to prevent it from 441 * overwriting the ip_id again. ip_id is already set to the 442 * ip_id of the encapsulated packet. 443 */ 444 error = ip_output(m, NULL, &sc->route, IP_FORWARDING, 445 (struct ip_moptions *)NULL, (struct inpcb *)NULL); 446 end: 447 sc->called = 0; 448 if (error) 449 ifp->if_oerrors++; 450 return (error); 451} 452 453static int 454gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 455{ 456 struct ifreq *ifr = (struct ifreq *)data; 457 struct if_laddrreq *lifr = (struct if_laddrreq *)data; 458 struct in_aliasreq *aifr = (struct in_aliasreq *)data; 459 struct gre_softc *sc = ifp->if_softc; 460 int s; 461 struct sockaddr_in si; 462 struct sockaddr *sa = NULL; 463 int error, adj; 464 struct sockaddr_in sp, sm, dp, dm; 465 uint32_t key; 466 467 error = 0; 468 adj = 0; 469 470 s = splnet(); 471 switch (cmd) { 472 case SIOCSIFADDR: 473 ifp->if_flags |= IFF_UP; 474 break; 475 case SIOCSIFDSTADDR: 476 break; 477 case SIOCSIFFLAGS: 478 /* 479 * XXXRW: Isn't this priv_check() redundant to the ifnet 480 * layer check? 481 */ 482 if ((error = priv_check(curthread, PRIV_NET_SETIFFLAGS)) != 0) 483 break; 484 if ((ifr->ifr_flags & IFF_LINK0) != 0) 485 sc->g_proto = IPPROTO_GRE; 486 else 487 sc->g_proto = IPPROTO_MOBILE; 488 if ((ifr->ifr_flags & IFF_LINK2) != 0) 489 sc->wccp_ver = WCCP_V2; 490 else 491 sc->wccp_ver = WCCP_V1; 492 goto recompute; 493 case SIOCSIFMTU: 494 /* 495 * XXXRW: Isn't this priv_check() redundant to the ifnet 496 * layer check? 497 */ 498 if ((error = priv_check(curthread, PRIV_NET_SETIFMTU)) != 0) 499 break; 500 if (ifr->ifr_mtu < 576) { 501 error = EINVAL; 502 break; 503 } 504 ifp->if_mtu = ifr->ifr_mtu; 505 break; 506 case SIOCGIFMTU: 507 ifr->ifr_mtu = GRE2IFP(sc)->if_mtu; 508 break; 509 case SIOCADDMULTI: 510 /* 511 * XXXRW: Isn't this priv_checkr() redundant to the ifnet 512 * layer check? 513 */ 514 if ((error = priv_check(curthread, PRIV_NET_ADDMULTI)) != 0) 515 break; 516 if (ifr == 0) { 517 error = EAFNOSUPPORT; 518 break; 519 } 520 switch (ifr->ifr_addr.sa_family) { 521#ifdef INET 522 case AF_INET: 523 break; 524#endif 525#ifdef INET6 526 case AF_INET6: 527 break; 528#endif 529 default: 530 error = EAFNOSUPPORT; 531 break; 532 } 533 break; 534 case SIOCDELMULTI: 535 /* 536 * XXXRW: Isn't this priv_check() redundant to the ifnet 537 * layer check? 538 */ 539 if ((error = priv_check(curthread, PRIV_NET_DELIFGROUP)) != 0) 540 break; 541 if (ifr == 0) { 542 error = EAFNOSUPPORT; 543 break; 544 } 545 switch (ifr->ifr_addr.sa_family) { 546#ifdef INET 547 case AF_INET: 548 break; 549#endif 550#ifdef INET6 551 case AF_INET6: 552 break; 553#endif 554 default: 555 error = EAFNOSUPPORT; 556 break; 557 } 558 break; 559 case GRESPROTO: 560 /* 561 * XXXRW: Isn't this priv_check() redundant to the ifnet 562 * layer check? 563 */ 564 if ((error = priv_check(curthread, PRIV_NET_GRE)) != 0) 565 break; 566 sc->g_proto = ifr->ifr_flags; 567 switch (sc->g_proto) { 568 case IPPROTO_GRE: 569 ifp->if_flags |= IFF_LINK0; 570 break; 571 case IPPROTO_MOBILE: 572 ifp->if_flags &= ~IFF_LINK0; 573 break; 574 default: 575 error = EPROTONOSUPPORT; 576 break; 577 } 578 goto recompute; 579 case GREGPROTO: 580 ifr->ifr_flags = sc->g_proto; 581 break; 582 case GRESADDRS: 583 case GRESADDRD: 584 error = priv_check(curthread, PRIV_NET_GRE); 585 if (error) 586 return (error); 587 /* 588 * set tunnel endpoints, compute a less specific route 589 * to the remote end and mark if as up 590 */ 591 sa = &ifr->ifr_addr; 592 if (cmd == GRESADDRS) 593 sc->g_src = (satosin(sa))->sin_addr; 594 if (cmd == GRESADDRD) 595 sc->g_dst = (satosin(sa))->sin_addr; 596 recompute: 597#ifdef INET 598 if (sc->encap != NULL) { 599 encap_detach(sc->encap); 600 sc->encap = NULL; 601 } 602#endif 603 if ((sc->g_src.s_addr != INADDR_ANY) && 604 (sc->g_dst.s_addr != INADDR_ANY)) { 605 bzero(&sp, sizeof(sp)); 606 bzero(&sm, sizeof(sm)); 607 bzero(&dp, sizeof(dp)); 608 bzero(&dm, sizeof(dm)); 609 sp.sin_len = sm.sin_len = dp.sin_len = dm.sin_len = 610 sizeof(struct sockaddr_in); 611 sp.sin_family = sm.sin_family = dp.sin_family = 612 dm.sin_family = AF_INET; 613 sp.sin_addr = sc->g_src; 614 dp.sin_addr = sc->g_dst; 615 sm.sin_addr.s_addr = dm.sin_addr.s_addr = 616 INADDR_BROADCAST; 617#ifdef INET 618 sc->encap = encap_attach(AF_INET, sc->g_proto, 619 sintosa(&sp), sintosa(&sm), sintosa(&dp), 620 sintosa(&dm), (sc->g_proto == IPPROTO_GRE) ? 621 &in_gre_protosw : &in_mobile_protosw, sc); 622 if (sc->encap == NULL) 623 printf("%s: unable to attach encap\n", 624 if_name(GRE2IFP(sc))); 625#endif 626 if (sc->route.ro_rt != 0) /* free old route */ 627 RTFREE(sc->route.ro_rt); 628 if (gre_compute_route(sc) == 0) 629 ifp->if_drv_flags |= IFF_DRV_RUNNING; 630 else 631 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 632 } 633 break; 634 case GREGADDRS: 635 memset(&si, 0, sizeof(si)); 636 si.sin_family = AF_INET; 637 si.sin_len = sizeof(struct sockaddr_in); 638 si.sin_addr.s_addr = sc->g_src.s_addr; 639 sa = sintosa(&si); 640 error = prison_if(curthread->td_ucred, sa); 641 if (error != 0) 642 break; 643 ifr->ifr_addr = *sa; 644 break; 645 case GREGADDRD: 646 memset(&si, 0, sizeof(si)); 647 si.sin_family = AF_INET; 648 si.sin_len = sizeof(struct sockaddr_in); 649 si.sin_addr.s_addr = sc->g_dst.s_addr; 650 sa = sintosa(&si); 651 error = prison_if(curthread->td_ucred, sa); 652 if (error != 0) 653 break; 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 error = prison_if(curthread->td_ucred, (struct sockaddr *)&si); 718 if (error != 0) 719 break; 720 memcpy(&lifr->addr, &si, sizeof(si)); 721 si.sin_addr.s_addr = sc->g_dst.s_addr; 722 error = prison_if(curthread->td_ucred, (struct sockaddr *)&si); 723 if (error != 0) 724 break; 725 memcpy(&lifr->dstaddr, &si, sizeof(si)); 726 break; 727 case SIOCGIFPSRCADDR: 728#ifdef INET6 729 case SIOCGIFPSRCADDR_IN6: 730#endif 731 if (sc->g_src.s_addr == INADDR_ANY) { 732 error = EADDRNOTAVAIL; 733 break; 734 } 735 memset(&si, 0, sizeof(si)); 736 si.sin_family = AF_INET; 737 si.sin_len = sizeof(struct sockaddr_in); 738 si.sin_addr.s_addr = sc->g_src.s_addr; 739 error = prison_if(curthread->td_ucred, (struct sockaddr *)&si); 740 if (error != 0) 741 break; 742 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr)); 743 break; 744 case SIOCGIFPDSTADDR: 745#ifdef INET6 746 case SIOCGIFPDSTADDR_IN6: 747#endif 748 if (sc->g_dst.s_addr == INADDR_ANY) { 749 error = EADDRNOTAVAIL; 750 break; 751 } 752 memset(&si, 0, sizeof(si)); 753 si.sin_family = AF_INET; 754 si.sin_len = sizeof(struct sockaddr_in); 755 si.sin_addr.s_addr = sc->g_dst.s_addr; 756 error = prison_if(curthread->td_ucred, (struct sockaddr *)&si); 757 if (error != 0) 758 break; 759 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr)); 760 break; 761 case GRESKEY: 762 error = priv_check(curthread, PRIV_NET_GRE); 763 if (error) 764 break; 765 error = copyin(ifr->ifr_data, &key, sizeof(key)); 766 if (error) 767 break; 768 /* adjust MTU for option header */ 769 if (key == 0 && sc->key != 0) /* clear */ 770 adj += sizeof(key); 771 else if (key != 0 && sc->key == 0) /* set */ 772 adj -= sizeof(key); 773 774 if (ifp->if_mtu + adj < 576) { 775 error = EINVAL; 776 break; 777 } 778 ifp->if_mtu += adj; 779 sc->key = key; 780 break; 781 case GREGKEY: 782 error = copyout(&sc->key, ifr->ifr_data, sizeof(sc->key)); 783 break; 784 785 default: 786 error = EINVAL; 787 break; 788 } 789 790 splx(s); 791 return (error); 792} 793 794/* 795 * computes a route to our destination that is not the one 796 * which would be taken by ip_output(), as this one will loop back to 797 * us. If the interface is p2p as a--->b, then a routing entry exists 798 * If we now send a packet to b (e.g. ping b), this will come down here 799 * gets src=a, dst=b tacked on and would from ip_output() sent back to 800 * if_gre. 801 * Goal here is to compute a route to b that is less specific than 802 * a-->b. We know that this one exists as in normal operation we have 803 * at least a default route which matches. 804 */ 805static int 806gre_compute_route(struct gre_softc *sc) 807{ 808 struct route *ro; 809 810 ro = &sc->route; 811 812 memset(ro, 0, sizeof(struct route)); 813 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst; 814 ro->ro_dst.sa_family = AF_INET; 815 ro->ro_dst.sa_len = sizeof(ro->ro_dst); 816 817 /* 818 * toggle last bit, so our interface is not found, but a less 819 * specific route. I'd rather like to specify a shorter mask, 820 * but this is not possible. Should work though. XXX 821 * XXX MRT Use a different FIB for the tunnel to solve this problem. 822 */ 823 if ((GRE2IFP(sc)->if_flags & IFF_LINK1) == 0) { 824 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr.s_addr ^= 825 htonl(0x01); 826 } 827 828#ifdef DIAGNOSTIC 829 printf("%s: searching for a route to %s", if_name(GRE2IFP(sc)), 830 inet_ntoa(((struct sockaddr_in *)&ro->ro_dst)->sin_addr)); 831#endif 832 833 rtalloc_fib(ro, sc->gre_fibnum); 834 835 /* 836 * check if this returned a route at all and this route is no 837 * recursion to ourself 838 */ 839 if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp->if_softc == sc) { 840#ifdef DIAGNOSTIC 841 if (ro->ro_rt == NULL) 842 printf(" - no route found!\n"); 843 else 844 printf(" - route loops back to ourself!\n"); 845#endif 846 return EADDRNOTAVAIL; 847 } 848 849 /* 850 * now change it back - else ip_output will just drop 851 * the route and search one to this interface ... 852 */ 853 if ((GRE2IFP(sc)->if_flags & IFF_LINK1) == 0) 854 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst; 855 856#ifdef DIAGNOSTIC 857 printf(", choosing %s with gateway %s", if_name(ro->ro_rt->rt_ifp), 858 inet_ntoa(((struct sockaddr_in *)(ro->ro_rt->rt_gateway))->sin_addr)); 859 printf("\n"); 860#endif 861 862 return 0; 863} 864 865/* 866 * do a checksum of a buffer - much like in_cksum, which operates on 867 * mbufs. 868 */ 869u_int16_t 870gre_in_cksum(u_int16_t *p, u_int len) 871{ 872 u_int32_t sum = 0; 873 int nwords = len >> 1; 874 875 while (nwords-- != 0) 876 sum += *p++; 877 878 if (len & 1) { 879 union { 880 u_short w; 881 u_char c[2]; 882 } u; 883 u.c[0] = *(u_char *)p; 884 u.c[1] = 0; 885 sum += u.w; 886 } 887 888 /* end-around-carry */ 889 sum = (sum >> 16) + (sum & 0xffff); 890 sum += (sum >> 16); 891 return (~sum); 892} 893 894static int 895gremodevent(module_t mod, int type, void *data) 896{ 897 898 switch (type) { 899 case MOD_LOAD: 900 greattach(); 901 break; 902 case MOD_UNLOAD: 903 if_clone_detach(&gre_cloner); 904 mtx_destroy(&gre_mtx); 905 break; 906 default: 907 return EOPNOTSUPP; 908 } 909 return 0; 910} 911 912static moduledata_t gre_mod = { 913 "if_gre", 914 gremodevent, 915 0 916}; 917 918DECLARE_MODULE(if_gre, gre_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 919MODULE_VERSION(if_gre, 1); 920