if_gre.c revision 241686
1/* $NetBSD: if_gre.c,v 1.49 2003/12/11 00:22:29 itojun Exp $ */ 2/* $FreeBSD: head/sys/net/if_gre.c 241686 2012-10-18 13:57:24Z andre $ */ 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/libkern.h> 52#include <sys/malloc.h> 53#include <sys/module.h> 54#include <sys/mbuf.h> 55#include <sys/priv.h> 56#include <sys/proc.h> 57#include <sys/protosw.h> 58#include <sys/socket.h> 59#include <sys/sockio.h> 60#include <sys/sysctl.h> 61#include <sys/systm.h> 62 63#include <net/ethernet.h> 64#include <net/if.h> 65#include <net/if_clone.h> 66#include <net/if_types.h> 67#include <net/route.h> 68#include <net/vnet.h> 69 70#ifdef INET 71#include <netinet/in.h> 72#include <netinet/in_systm.h> 73#include <netinet/in_var.h> 74#include <netinet/ip.h> 75#include <netinet/ip_gre.h> 76#include <netinet/ip_var.h> 77#include <netinet/ip_encap.h> 78#else 79#error "Huh? if_gre without inet?" 80#endif 81 82#include <net/bpf.h> 83 84#include <net/if_gre.h> 85 86/* 87 * It is not easy to calculate the right value for a GRE MTU. 88 * We leave this task to the admin and use the same default that 89 * other vendors use. 90 */ 91#define GREMTU 1476 92 93#define MTAG_COOKIE_GRE 1307983903 94#define MTAG_GRE_NESTING 1 95struct mtag_gre_nesting { 96 uint16_t count; 97 uint16_t max; 98 struct ifnet *ifp[]; 99}; 100 101/* 102 * gre_mtx protects all global variables in if_gre.c. 103 * XXX: gre_softc data not protected yet. 104 */ 105struct mtx gre_mtx; 106static const char grename[] = "gre"; 107static MALLOC_DEFINE(M_GRE, grename, "Generic Routing Encapsulation"); 108 109struct gre_softc_head gre_softc_list; 110 111static int gre_clone_create(struct if_clone *, int, caddr_t); 112static void gre_clone_destroy(struct ifnet *); 113static struct if_clone *gre_cloner; 114 115static int gre_ioctl(struct ifnet *, u_long, caddr_t); 116static int gre_output(struct ifnet *, struct mbuf *, struct sockaddr *, 117 struct route *ro); 118 119static int gre_compute_route(struct gre_softc *sc); 120 121static void greattach(void); 122 123#ifdef INET 124extern struct domain inetdomain; 125static const struct protosw in_gre_protosw = { 126 .pr_type = SOCK_RAW, 127 .pr_domain = &inetdomain, 128 .pr_protocol = IPPROTO_GRE, 129 .pr_flags = PR_ATOMIC|PR_ADDR, 130 .pr_input = gre_input, 131 .pr_output = (pr_output_t *)rip_output, 132 .pr_ctlinput = rip_ctlinput, 133 .pr_ctloutput = rip_ctloutput, 134 .pr_usrreqs = &rip_usrreqs 135}; 136static const struct protosw in_mobile_protosw = { 137 .pr_type = SOCK_RAW, 138 .pr_domain = &inetdomain, 139 .pr_protocol = IPPROTO_MOBILE, 140 .pr_flags = PR_ATOMIC|PR_ADDR, 141 .pr_input = gre_mobile_input, 142 .pr_output = (pr_output_t *)rip_output, 143 .pr_ctlinput = rip_ctlinput, 144 .pr_ctloutput = rip_ctloutput, 145 .pr_usrreqs = &rip_usrreqs 146}; 147#endif 148 149SYSCTL_DECL(_net_link); 150static SYSCTL_NODE(_net_link, IFT_TUNNEL, gre, CTLFLAG_RW, 0, 151 "Generic Routing Encapsulation"); 152#ifndef MAX_GRE_NEST 153/* 154 * This macro controls the default upper limitation on nesting of gre tunnels. 155 * Since, setting a large value to this macro with a careless configuration 156 * may introduce system crash, we don't allow any nestings by default. 157 * If you need to configure nested gre tunnels, you can define this macro 158 * in your kernel configuration file. However, if you do so, please be 159 * careful to configure the tunnels so that it won't make a loop. 160 */ 161#define MAX_GRE_NEST 1 162#endif 163static int max_gre_nesting = MAX_GRE_NEST; 164SYSCTL_INT(_net_link_gre, OID_AUTO, max_nesting, CTLFLAG_RW, 165 &max_gre_nesting, 0, "Max nested tunnels"); 166 167/* ARGSUSED */ 168static void 169greattach(void) 170{ 171 172 mtx_init(&gre_mtx, "gre_mtx", NULL, MTX_DEF); 173 LIST_INIT(&gre_softc_list); 174 gre_cloner = if_clone_simple(grename, gre_clone_create, 175 gre_clone_destroy, 0); 176} 177 178static int 179gre_clone_create(ifc, unit, params) 180 struct if_clone *ifc; 181 int unit; 182 caddr_t params; 183{ 184 struct gre_softc *sc; 185 186 sc = malloc(sizeof(struct gre_softc), M_GRE, M_WAITOK | M_ZERO); 187 188 GRE2IFP(sc) = if_alloc(IFT_TUNNEL); 189 if (GRE2IFP(sc) == NULL) { 190 free(sc, M_GRE); 191 return (ENOSPC); 192 } 193 194 GRE2IFP(sc)->if_softc = sc; 195 if_initname(GRE2IFP(sc), grename, unit); 196 197 GRE2IFP(sc)->if_snd.ifq_maxlen = ifqmaxlen; 198 GRE2IFP(sc)->if_addrlen = 0; 199 GRE2IFP(sc)->if_hdrlen = 24; /* IP + GRE */ 200 GRE2IFP(sc)->if_mtu = GREMTU; 201 GRE2IFP(sc)->if_flags = IFF_POINTOPOINT|IFF_MULTICAST; 202 GRE2IFP(sc)->if_output = gre_output; 203 GRE2IFP(sc)->if_ioctl = gre_ioctl; 204 sc->g_dst.s_addr = sc->g_src.s_addr = INADDR_ANY; 205 sc->g_proto = IPPROTO_GRE; 206 GRE2IFP(sc)->if_flags |= IFF_LINK0; 207 sc->encap = NULL; 208 sc->gre_fibnum = curthread->td_proc->p_fibnum; 209 sc->wccp_ver = WCCP_V1; 210 sc->key = 0; 211 if_attach(GRE2IFP(sc)); 212 bpfattach(GRE2IFP(sc), DLT_NULL, sizeof(u_int32_t)); 213 mtx_lock(&gre_mtx); 214 LIST_INSERT_HEAD(&gre_softc_list, sc, sc_list); 215 mtx_unlock(&gre_mtx); 216 return (0); 217} 218 219static void 220gre_clone_destroy(ifp) 221 struct ifnet *ifp; 222{ 223 struct gre_softc *sc = ifp->if_softc; 224 225 mtx_lock(&gre_mtx); 226 LIST_REMOVE(sc, sc_list); 227 mtx_unlock(&gre_mtx); 228 229#ifdef INET 230 if (sc->encap != NULL) 231 encap_detach(sc->encap); 232#endif 233 bpfdetach(ifp); 234 if_detach(ifp); 235 if_free(ifp); 236 free(sc, M_GRE); 237} 238 239/* 240 * The output routine. Takes a packet and encapsulates it in the protocol 241 * given by sc->g_proto. See also RFC 1701 and RFC 2004 242 */ 243static int 244gre_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 245 struct route *ro) 246{ 247 int error = 0; 248 struct gre_softc *sc = ifp->if_softc; 249 struct greip *gh; 250 struct ip *ip; 251 struct m_tag *mtag; 252 struct mtag_gre_nesting *gt; 253 size_t len; 254 u_short gre_ip_id = 0; 255 uint8_t gre_ip_tos = 0; 256 u_int16_t etype = 0; 257 struct mobile_h mob_h; 258 u_int32_t af; 259 int extra = 0, max; 260 261 /* 262 * gre may cause infinite recursion calls when misconfigured. High 263 * nesting level may cause stack exhaustion. We'll prevent this by 264 * detecting loops and by introducing upper limit. 265 */ 266 mtag = m_tag_locate(m, MTAG_COOKIE_GRE, MTAG_GRE_NESTING, NULL); 267 if (mtag != NULL) { 268 struct ifnet **ifp2; 269 270 gt = (struct mtag_gre_nesting *)(mtag + 1); 271 gt->count++; 272 if (gt->count > min(gt->max,max_gre_nesting)) { 273 printf("%s: hit maximum recursion limit %u on %s\n", 274 __func__, gt->count - 1, ifp->if_xname); 275 m_freem(m); 276 error = EIO; /* is there better errno? */ 277 goto end; 278 } 279 280 ifp2 = gt->ifp; 281 for (max = gt->count - 1; max > 0; max--) { 282 if (*ifp2 == ifp) 283 break; 284 ifp2++; 285 } 286 if (*ifp2 == ifp) { 287 printf("%s: detected loop with nexting %u on %s\n", 288 __func__, gt->count-1, ifp->if_xname); 289 m_freem(m); 290 error = EIO; /* is there better errno? */ 291 goto end; 292 } 293 *ifp2 = ifp; 294 295 } else { 296 /* 297 * Given that people should NOT increase max_gre_nesting beyond 298 * their real needs, we allocate once per packet rather than 299 * allocating an mtag once per passing through gre. 300 * 301 * Note: the sysctl does not actually check for saneness, so we 302 * limit the maximum numbers of possible recursions here. 303 */ 304 max = imin(max_gre_nesting, 256); 305 /* If someone sets the sysctl <= 0, we want at least 1. */ 306 max = imax(max, 1); 307 len = sizeof(struct mtag_gre_nesting) + 308 max * sizeof(struct ifnet *); 309 mtag = m_tag_alloc(MTAG_COOKIE_GRE, MTAG_GRE_NESTING, len, 310 M_NOWAIT); 311 if (mtag == NULL) { 312 m_freem(m); 313 error = ENOMEM; 314 goto end; 315 } 316 gt = (struct mtag_gre_nesting *)(mtag + 1); 317 bzero(gt, len); 318 gt->count = 1; 319 gt->max = max; 320 *gt->ifp = ifp; 321 m_tag_prepend(m, mtag); 322 } 323 324 if (!((ifp->if_flags & IFF_UP) && 325 (ifp->if_drv_flags & IFF_DRV_RUNNING)) || 326 sc->g_src.s_addr == INADDR_ANY || sc->g_dst.s_addr == INADDR_ANY) { 327 m_freem(m); 328 error = ENETDOWN; 329 goto end; 330 } 331 332 gh = NULL; 333 ip = NULL; 334 335 /* BPF writes need to be handled specially. */ 336 if (dst->sa_family == AF_UNSPEC) { 337 bcopy(dst->sa_data, &af, sizeof(af)); 338 dst->sa_family = af; 339 } 340 341 if (bpf_peers_present(ifp->if_bpf)) { 342 af = dst->sa_family; 343 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 344 } 345 346 m->m_flags &= ~(M_BCAST|M_MCAST); 347 348 if (sc->g_proto == IPPROTO_MOBILE) { 349 if (dst->sa_family == AF_INET) { 350 struct mbuf *m0; 351 int msiz; 352 353 ip = mtod(m, struct ip *); 354 355 /* 356 * RFC2004 specifies that fragmented diagrams shouldn't 357 * be encapsulated. 358 */ 359 if (ip->ip_off & (IP_MF | IP_OFFMASK)) { 360 _IF_DROP(&ifp->if_snd); 361 m_freem(m); 362 error = EINVAL; /* is there better errno? */ 363 goto end; 364 } 365 memset(&mob_h, 0, MOB_H_SIZ_L); 366 mob_h.proto = (ip->ip_p) << 8; 367 mob_h.odst = ip->ip_dst.s_addr; 368 ip->ip_dst.s_addr = sc->g_dst.s_addr; 369 370 /* 371 * If the packet comes from our host, we only change 372 * the destination address in the IP header. 373 * Else we also need to save and change the source 374 */ 375 if (in_hosteq(ip->ip_src, sc->g_src)) { 376 msiz = MOB_H_SIZ_S; 377 } else { 378 mob_h.proto |= MOB_H_SBIT; 379 mob_h.osrc = ip->ip_src.s_addr; 380 ip->ip_src.s_addr = sc->g_src.s_addr; 381 msiz = MOB_H_SIZ_L; 382 } 383 mob_h.proto = htons(mob_h.proto); 384 mob_h.hcrc = gre_in_cksum((u_int16_t *)&mob_h, msiz); 385 386 if ((m->m_data - msiz) < m->m_pktdat) { 387 /* need new mbuf */ 388 MGETHDR(m0, M_DONTWAIT, MT_DATA); 389 if (m0 == NULL) { 390 _IF_DROP(&ifp->if_snd); 391 m_freem(m); 392 error = ENOBUFS; 393 goto end; 394 } 395 m0->m_next = m; 396 m->m_data += sizeof(struct ip); 397 m->m_len -= sizeof(struct ip); 398 m0->m_pkthdr.len = m->m_pkthdr.len + msiz; 399 m0->m_len = msiz + sizeof(struct ip); 400 m0->m_data += max_linkhdr; 401 memcpy(mtod(m0, caddr_t), (caddr_t)ip, 402 sizeof(struct ip)); 403 m = m0; 404 } else { /* we have some space left in the old one */ 405 m->m_data -= msiz; 406 m->m_len += msiz; 407 m->m_pkthdr.len += msiz; 408 bcopy(ip, mtod(m, caddr_t), 409 sizeof(struct ip)); 410 } 411 ip = mtod(m, struct ip *); 412 memcpy((caddr_t)(ip + 1), &mob_h, (unsigned)msiz); 413 ip->ip_len = ntohs(ip->ip_len) + msiz; 414 } else { /* AF_INET */ 415 _IF_DROP(&ifp->if_snd); 416 m_freem(m); 417 error = EINVAL; 418 goto end; 419 } 420 } else if (sc->g_proto == IPPROTO_GRE) { 421 switch (dst->sa_family) { 422 case AF_INET: 423 ip = mtod(m, struct ip *); 424 gre_ip_tos = ip->ip_tos; 425 gre_ip_id = ip->ip_id; 426 if (sc->wccp_ver == WCCP_V2) { 427 extra = sizeof(uint32_t); 428 etype = WCCP_PROTOCOL_TYPE; 429 } else { 430 etype = ETHERTYPE_IP; 431 } 432 break; 433#ifdef INET6 434 case AF_INET6: 435 gre_ip_id = ip_newid(); 436 etype = ETHERTYPE_IPV6; 437 break; 438#endif 439#ifdef NETATALK 440 case AF_APPLETALK: 441 etype = ETHERTYPE_ATALK; 442 break; 443#endif 444 default: 445 _IF_DROP(&ifp->if_snd); 446 m_freem(m); 447 error = EAFNOSUPPORT; 448 goto end; 449 } 450 451 /* Reserve space for GRE header + optional GRE key */ 452 int hdrlen = sizeof(struct greip) + extra; 453 if (sc->key) 454 hdrlen += sizeof(uint32_t); 455 M_PREPEND(m, hdrlen, M_DONTWAIT); 456 } else { 457 _IF_DROP(&ifp->if_snd); 458 m_freem(m); 459 error = EINVAL; 460 goto end; 461 } 462 463 if (m == NULL) { /* mbuf allocation failed */ 464 _IF_DROP(&ifp->if_snd); 465 error = ENOBUFS; 466 goto end; 467 } 468 469 M_SETFIB(m, sc->gre_fibnum); /* The envelope may use a different FIB */ 470 471 gh = mtod(m, struct greip *); 472 if (sc->g_proto == IPPROTO_GRE) { 473 uint32_t *options = gh->gi_options; 474 475 memset((void *)gh, 0, sizeof(struct greip) + extra); 476 gh->gi_ptype = htons(etype); 477 gh->gi_flags = 0; 478 479 /* Add key option */ 480 if (sc->key) 481 { 482 gh->gi_flags |= htons(GRE_KP); 483 *(options++) = htonl(sc->key); 484 } 485 } 486 487 gh->gi_pr = sc->g_proto; 488 if (sc->g_proto != IPPROTO_MOBILE) { 489 gh->gi_src = sc->g_src; 490 gh->gi_dst = sc->g_dst; 491 ((struct ip*)gh)->ip_v = IPPROTO_IPV4; 492 ((struct ip*)gh)->ip_hl = (sizeof(struct ip)) >> 2; 493 ((struct ip*)gh)->ip_ttl = GRE_TTL; 494 ((struct ip*)gh)->ip_tos = gre_ip_tos; 495 ((struct ip*)gh)->ip_id = gre_ip_id; 496 gh->gi_len = m->m_pkthdr.len; 497 } 498 499 ifp->if_opackets++; 500 ifp->if_obytes += m->m_pkthdr.len; 501 /* 502 * Send it off and with IP_FORWARD flag to prevent it from 503 * overwriting the ip_id again. ip_id is already set to the 504 * ip_id of the encapsulated packet. 505 */ 506 error = ip_output(m, NULL, &sc->route, IP_FORWARDING, 507 (struct ip_moptions *)NULL, (struct inpcb *)NULL); 508 end: 509 if (error) 510 ifp->if_oerrors++; 511 return (error); 512} 513 514static int 515gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 516{ 517 struct ifreq *ifr = (struct ifreq *)data; 518 struct if_laddrreq *lifr = (struct if_laddrreq *)data; 519 struct in_aliasreq *aifr = (struct in_aliasreq *)data; 520 struct gre_softc *sc = ifp->if_softc; 521 struct sockaddr_in si; 522 struct sockaddr *sa = NULL; 523 int error, adj; 524 struct sockaddr_in sp, sm, dp, dm; 525 uint32_t key; 526 527 error = 0; 528 adj = 0; 529 530 switch (cmd) { 531 case SIOCSIFADDR: 532 ifp->if_flags |= IFF_UP; 533 break; 534 case SIOCSIFDSTADDR: 535 break; 536 case SIOCSIFFLAGS: 537 /* 538 * XXXRW: Isn't this priv_check() redundant to the ifnet 539 * layer check? 540 */ 541 if ((error = priv_check(curthread, PRIV_NET_SETIFFLAGS)) != 0) 542 break; 543 if ((ifr->ifr_flags & IFF_LINK0) != 0) 544 sc->g_proto = IPPROTO_GRE; 545 else 546 sc->g_proto = IPPROTO_MOBILE; 547 if ((ifr->ifr_flags & IFF_LINK2) != 0) 548 sc->wccp_ver = WCCP_V2; 549 else 550 sc->wccp_ver = WCCP_V1; 551 goto recompute; 552 case SIOCSIFMTU: 553 /* 554 * XXXRW: Isn't this priv_check() redundant to the ifnet 555 * layer check? 556 */ 557 if ((error = priv_check(curthread, PRIV_NET_SETIFMTU)) != 0) 558 break; 559 if (ifr->ifr_mtu < 576) { 560 error = EINVAL; 561 break; 562 } 563 ifp->if_mtu = ifr->ifr_mtu; 564 break; 565 case SIOCGIFMTU: 566 ifr->ifr_mtu = GRE2IFP(sc)->if_mtu; 567 break; 568 case SIOCADDMULTI: 569 /* 570 * XXXRW: Isn't this priv_checkr() redundant to the ifnet 571 * layer check? 572 */ 573 if ((error = priv_check(curthread, PRIV_NET_ADDMULTI)) != 0) 574 break; 575 if (ifr == 0) { 576 error = EAFNOSUPPORT; 577 break; 578 } 579 switch (ifr->ifr_addr.sa_family) { 580#ifdef INET 581 case AF_INET: 582 break; 583#endif 584#ifdef INET6 585 case AF_INET6: 586 break; 587#endif 588 default: 589 error = EAFNOSUPPORT; 590 break; 591 } 592 break; 593 case SIOCDELMULTI: 594 /* 595 * XXXRW: Isn't this priv_check() redundant to the ifnet 596 * layer check? 597 */ 598 if ((error = priv_check(curthread, PRIV_NET_DELIFGROUP)) != 0) 599 break; 600 if (ifr == 0) { 601 error = EAFNOSUPPORT; 602 break; 603 } 604 switch (ifr->ifr_addr.sa_family) { 605#ifdef INET 606 case AF_INET: 607 break; 608#endif 609#ifdef INET6 610 case AF_INET6: 611 break; 612#endif 613 default: 614 error = EAFNOSUPPORT; 615 break; 616 } 617 break; 618 case GRESPROTO: 619 /* 620 * XXXRW: Isn't this priv_check() redundant to the ifnet 621 * layer check? 622 */ 623 if ((error = priv_check(curthread, PRIV_NET_GRE)) != 0) 624 break; 625 sc->g_proto = ifr->ifr_flags; 626 switch (sc->g_proto) { 627 case IPPROTO_GRE: 628 ifp->if_flags |= IFF_LINK0; 629 break; 630 case IPPROTO_MOBILE: 631 ifp->if_flags &= ~IFF_LINK0; 632 break; 633 default: 634 error = EPROTONOSUPPORT; 635 break; 636 } 637 goto recompute; 638 case GREGPROTO: 639 ifr->ifr_flags = sc->g_proto; 640 break; 641 case GRESADDRS: 642 case GRESADDRD: 643 error = priv_check(curthread, PRIV_NET_GRE); 644 if (error) 645 return (error); 646 /* 647 * set tunnel endpoints, compute a less specific route 648 * to the remote end and mark if as up 649 */ 650 sa = &ifr->ifr_addr; 651 if (cmd == GRESADDRS) 652 sc->g_src = (satosin(sa))->sin_addr; 653 if (cmd == GRESADDRD) 654 sc->g_dst = (satosin(sa))->sin_addr; 655 recompute: 656#ifdef INET 657 if (sc->encap != NULL) { 658 encap_detach(sc->encap); 659 sc->encap = NULL; 660 } 661#endif 662 if ((sc->g_src.s_addr != INADDR_ANY) && 663 (sc->g_dst.s_addr != INADDR_ANY)) { 664 bzero(&sp, sizeof(sp)); 665 bzero(&sm, sizeof(sm)); 666 bzero(&dp, sizeof(dp)); 667 bzero(&dm, sizeof(dm)); 668 sp.sin_len = sm.sin_len = dp.sin_len = dm.sin_len = 669 sizeof(struct sockaddr_in); 670 sp.sin_family = sm.sin_family = dp.sin_family = 671 dm.sin_family = AF_INET; 672 sp.sin_addr = sc->g_src; 673 dp.sin_addr = sc->g_dst; 674 sm.sin_addr.s_addr = dm.sin_addr.s_addr = 675 INADDR_BROADCAST; 676#ifdef INET 677 sc->encap = encap_attach(AF_INET, sc->g_proto, 678 sintosa(&sp), sintosa(&sm), sintosa(&dp), 679 sintosa(&dm), (sc->g_proto == IPPROTO_GRE) ? 680 &in_gre_protosw : &in_mobile_protosw, sc); 681 if (sc->encap == NULL) 682 printf("%s: unable to attach encap\n", 683 if_name(GRE2IFP(sc))); 684#endif 685 if (sc->route.ro_rt != 0) /* free old route */ 686 RTFREE(sc->route.ro_rt); 687 if (gre_compute_route(sc) == 0) 688 ifp->if_drv_flags |= IFF_DRV_RUNNING; 689 else 690 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 691 } 692 break; 693 case GREGADDRS: 694 memset(&si, 0, sizeof(si)); 695 si.sin_family = AF_INET; 696 si.sin_len = sizeof(struct sockaddr_in); 697 si.sin_addr.s_addr = sc->g_src.s_addr; 698 sa = sintosa(&si); 699 error = prison_if(curthread->td_ucred, sa); 700 if (error != 0) 701 break; 702 ifr->ifr_addr = *sa; 703 break; 704 case GREGADDRD: 705 memset(&si, 0, sizeof(si)); 706 si.sin_family = AF_INET; 707 si.sin_len = sizeof(struct sockaddr_in); 708 si.sin_addr.s_addr = sc->g_dst.s_addr; 709 sa = sintosa(&si); 710 error = prison_if(curthread->td_ucred, sa); 711 if (error != 0) 712 break; 713 ifr->ifr_addr = *sa; 714 break; 715 case SIOCSIFPHYADDR: 716 /* 717 * XXXRW: Isn't this priv_check() redundant to the ifnet 718 * layer check? 719 */ 720 if ((error = priv_check(curthread, PRIV_NET_SETIFPHYS)) != 0) 721 break; 722 if (aifr->ifra_addr.sin_family != AF_INET || 723 aifr->ifra_dstaddr.sin_family != AF_INET) { 724 error = EAFNOSUPPORT; 725 break; 726 } 727 if (aifr->ifra_addr.sin_len != sizeof(si) || 728 aifr->ifra_dstaddr.sin_len != sizeof(si)) { 729 error = EINVAL; 730 break; 731 } 732 sc->g_src = aifr->ifra_addr.sin_addr; 733 sc->g_dst = aifr->ifra_dstaddr.sin_addr; 734 goto recompute; 735 case SIOCSLIFPHYADDR: 736 /* 737 * XXXRW: Isn't this priv_check() redundant to the ifnet 738 * layer check? 739 */ 740 if ((error = priv_check(curthread, PRIV_NET_SETIFPHYS)) != 0) 741 break; 742 if (lifr->addr.ss_family != AF_INET || 743 lifr->dstaddr.ss_family != AF_INET) { 744 error = EAFNOSUPPORT; 745 break; 746 } 747 if (lifr->addr.ss_len != sizeof(si) || 748 lifr->dstaddr.ss_len != sizeof(si)) { 749 error = EINVAL; 750 break; 751 } 752 sc->g_src = (satosin(&lifr->addr))->sin_addr; 753 sc->g_dst = 754 (satosin(&lifr->dstaddr))->sin_addr; 755 goto recompute; 756 case SIOCDIFPHYADDR: 757 /* 758 * XXXRW: Isn't this priv_check() redundant to the ifnet 759 * layer check? 760 */ 761 if ((error = priv_check(curthread, PRIV_NET_SETIFPHYS)) != 0) 762 break; 763 sc->g_src.s_addr = INADDR_ANY; 764 sc->g_dst.s_addr = INADDR_ANY; 765 goto recompute; 766 case SIOCGLIFPHYADDR: 767 if (sc->g_src.s_addr == INADDR_ANY || 768 sc->g_dst.s_addr == INADDR_ANY) { 769 error = EADDRNOTAVAIL; 770 break; 771 } 772 memset(&si, 0, sizeof(si)); 773 si.sin_family = AF_INET; 774 si.sin_len = sizeof(struct sockaddr_in); 775 si.sin_addr.s_addr = sc->g_src.s_addr; 776 error = prison_if(curthread->td_ucred, (struct sockaddr *)&si); 777 if (error != 0) 778 break; 779 memcpy(&lifr->addr, &si, sizeof(si)); 780 si.sin_addr.s_addr = sc->g_dst.s_addr; 781 error = prison_if(curthread->td_ucred, (struct sockaddr *)&si); 782 if (error != 0) 783 break; 784 memcpy(&lifr->dstaddr, &si, sizeof(si)); 785 break; 786 case SIOCGIFPSRCADDR: 787#ifdef INET6 788 case SIOCGIFPSRCADDR_IN6: 789#endif 790 if (sc->g_src.s_addr == INADDR_ANY) { 791 error = EADDRNOTAVAIL; 792 break; 793 } 794 memset(&si, 0, sizeof(si)); 795 si.sin_family = AF_INET; 796 si.sin_len = sizeof(struct sockaddr_in); 797 si.sin_addr.s_addr = sc->g_src.s_addr; 798 error = prison_if(curthread->td_ucred, (struct sockaddr *)&si); 799 if (error != 0) 800 break; 801 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr)); 802 break; 803 case SIOCGIFPDSTADDR: 804#ifdef INET6 805 case SIOCGIFPDSTADDR_IN6: 806#endif 807 if (sc->g_dst.s_addr == INADDR_ANY) { 808 error = EADDRNOTAVAIL; 809 break; 810 } 811 memset(&si, 0, sizeof(si)); 812 si.sin_family = AF_INET; 813 si.sin_len = sizeof(struct sockaddr_in); 814 si.sin_addr.s_addr = sc->g_dst.s_addr; 815 error = prison_if(curthread->td_ucred, (struct sockaddr *)&si); 816 if (error != 0) 817 break; 818 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr)); 819 break; 820 case GRESKEY: 821 error = priv_check(curthread, PRIV_NET_GRE); 822 if (error) 823 break; 824 error = copyin(ifr->ifr_data, &key, sizeof(key)); 825 if (error) 826 break; 827 /* adjust MTU for option header */ 828 if (key == 0 && sc->key != 0) /* clear */ 829 adj += sizeof(key); 830 else if (key != 0 && sc->key == 0) /* set */ 831 adj -= sizeof(key); 832 833 if (ifp->if_mtu + adj < 576) { 834 error = EINVAL; 835 break; 836 } 837 ifp->if_mtu += adj; 838 sc->key = key; 839 break; 840 case GREGKEY: 841 error = copyout(&sc->key, ifr->ifr_data, sizeof(sc->key)); 842 break; 843 844 default: 845 error = EINVAL; 846 break; 847 } 848 849 return (error); 850} 851 852/* 853 * computes a route to our destination that is not the one 854 * which would be taken by ip_output(), as this one will loop back to 855 * us. If the interface is p2p as a--->b, then a routing entry exists 856 * If we now send a packet to b (e.g. ping b), this will come down here 857 * gets src=a, dst=b tacked on and would from ip_output() sent back to 858 * if_gre. 859 * Goal here is to compute a route to b that is less specific than 860 * a-->b. We know that this one exists as in normal operation we have 861 * at least a default route which matches. 862 */ 863static int 864gre_compute_route(struct gre_softc *sc) 865{ 866 struct route *ro; 867 868 ro = &sc->route; 869 870 memset(ro, 0, sizeof(struct route)); 871 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst; 872 ro->ro_dst.sa_family = AF_INET; 873 ro->ro_dst.sa_len = sizeof(ro->ro_dst); 874 875 /* 876 * toggle last bit, so our interface is not found, but a less 877 * specific route. I'd rather like to specify a shorter mask, 878 * but this is not possible. Should work though. XXX 879 * XXX MRT Use a different FIB for the tunnel to solve this problem. 880 */ 881 if ((GRE2IFP(sc)->if_flags & IFF_LINK1) == 0) { 882 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr.s_addr ^= 883 htonl(0x01); 884 } 885 886#ifdef DIAGNOSTIC 887 printf("%s: searching for a route to %s", if_name(GRE2IFP(sc)), 888 inet_ntoa(((struct sockaddr_in *)&ro->ro_dst)->sin_addr)); 889#endif 890 891 rtalloc_fib(ro, sc->gre_fibnum); 892 893 /* 894 * check if this returned a route at all and this route is no 895 * recursion to ourself 896 */ 897 if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp->if_softc == sc) { 898#ifdef DIAGNOSTIC 899 if (ro->ro_rt == NULL) 900 printf(" - no route found!\n"); 901 else 902 printf(" - route loops back to ourself!\n"); 903#endif 904 return EADDRNOTAVAIL; 905 } 906 907 /* 908 * now change it back - else ip_output will just drop 909 * the route and search one to this interface ... 910 */ 911 if ((GRE2IFP(sc)->if_flags & IFF_LINK1) == 0) 912 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst; 913 914#ifdef DIAGNOSTIC 915 printf(", choosing %s with gateway %s", if_name(ro->ro_rt->rt_ifp), 916 inet_ntoa(((struct sockaddr_in *)(ro->ro_rt->rt_gateway))->sin_addr)); 917 printf("\n"); 918#endif 919 920 return 0; 921} 922 923/* 924 * do a checksum of a buffer - much like in_cksum, which operates on 925 * mbufs. 926 */ 927u_int16_t 928gre_in_cksum(u_int16_t *p, u_int len) 929{ 930 u_int32_t sum = 0; 931 int nwords = len >> 1; 932 933 while (nwords-- != 0) 934 sum += *p++; 935 936 if (len & 1) { 937 union { 938 u_short w; 939 u_char c[2]; 940 } u; 941 u.c[0] = *(u_char *)p; 942 u.c[1] = 0; 943 sum += u.w; 944 } 945 946 /* end-around-carry */ 947 sum = (sum >> 16) + (sum & 0xffff); 948 sum += (sum >> 16); 949 return (~sum); 950} 951 952static int 953gremodevent(module_t mod, int type, void *data) 954{ 955 956 switch (type) { 957 case MOD_LOAD: 958 greattach(); 959 break; 960 case MOD_UNLOAD: 961 if_clone_detach(gre_cloner); 962 mtx_destroy(&gre_mtx); 963 break; 964 default: 965 return EOPNOTSUPP; 966 } 967 return 0; 968} 969 970static moduledata_t gre_mod = { 971 "if_gre", 972 gremodevent, 973 0 974}; 975 976DECLARE_MODULE(if_gre, gre_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 977MODULE_VERSION(if_gre, 1); 978