1 /* $NetBSD: if_gre.c,v 1.49 2003/12/11 00:22:29 itojun Exp $ */ 2 /* $FreeBSD$ */ 3 4 /*- 5 * Copyright (c) 1998 The NetBSD Foundation, Inc. 6 * All rights reserved. 7 * 8 * This code is derived from software contributed to The NetBSD Foundation 9 * by Heiko W.Rupp <hwr@pilhuhn.de> 10 * 11 * IPv6-over-GRE contributed by Gert Doering <gert@greenie.muc.de> 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 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 95 struct 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 */ 105 struct mtx gre_mtx; 106 static const char grename[] = "gre"; 107 static MALLOC_DEFINE(M_GRE, grename, "Generic Routing Encapsulation"); 108 109 struct gre_softc_head gre_softc_list; 110 111 static int gre_clone_create(struct if_clone *, int, caddr_t); 112 static void gre_clone_destroy(struct ifnet *); 113 static struct if_clone *gre_cloner; 114 115 static int gre_ioctl(struct ifnet *, u_long, caddr_t); 116 static int gre_output(struct ifnet *, struct mbuf *, struct sockaddr *, 117 struct route *ro); 118 119 static int gre_compute_route(struct gre_softc *sc); 120 121 static void greattach(void); 122 123 #ifdef INET 124 extern struct domain inetdomain; 125 static 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 }; 136 static 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 148 149 SYSCTL_DECL(_net_link); 150 static 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 163 static int max_gre_nesting = MAX_GRE_NEST; 164 SYSCTL_INT(_net_link_gre, OID_AUTO, max_nesting, CTLFLAG_RW, 165 &max_gre_nesting, 0, "Max nested tunnels"); 166 167 /* ARGSUSED */ 168 static void 169 greattach(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 } 177 178 static int 179 gre_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 } 218 219 static void 220 gre_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 */ 243 static int 244 gre_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 & htons(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 m0 = m_gethdr(M_NOWAIT, MT_DATA); 388 if (m0 == NULL) { 389 _IF_DROP(&ifp->if_snd); 390 m_freem(m); 391 error = ENOBUFS; 392 goto end; 393 } 394 m0->m_next = m; 395 m->m_data += sizeof(struct ip); 396 m->m_len -= sizeof(struct ip); 397 m0->m_pkthdr.len = m->m_pkthdr.len + msiz; 398 m0->m_len = msiz + sizeof(struct ip); 399 m0->m_data += max_linkhdr; 400 memcpy(mtod(m0, caddr_t), (caddr_t)ip, 401 sizeof(struct ip)); 402 m = m0; 403 } else { /* we have some space left in the old one */ 404 m->m_data -= msiz; 405 m->m_len += msiz; 406 m->m_pkthdr.len += msiz; 407 bcopy(ip, mtod(m, caddr_t), 408 sizeof(struct ip)); 409 } 410 ip = mtod(m, struct ip *); 411 memcpy((caddr_t)(ip + 1), &mob_h, (unsigned)msiz); 412 ip->ip_len = htons(ntohs(ip->ip_len) + msiz); 413 } else { /* AF_INET */ 414 _IF_DROP(&ifp->if_snd); 415 m_freem(m); 416 error = EINVAL; 417 goto end; 418 } 419 } else if (sc->g_proto == IPPROTO_GRE) { 420 switch (dst->sa_family) { 421 case AF_INET: 422 ip = mtod(m, struct ip *); 423 gre_ip_tos = ip->ip_tos; 424 gre_ip_id = ip->ip_id; 425 if (sc->wccp_ver == WCCP_V2) { 426 extra = sizeof(uint32_t); 427 etype = WCCP_PROTOCOL_TYPE; 428 } else { 429 etype = ETHERTYPE_IP; 430 } 431 break; 432 #ifdef INET6 433 case AF_INET6: 434 gre_ip_id = ip_newid(); 435 etype = ETHERTYPE_IPV6; 436 break; 437 #endif 438 #ifdef NETATALK 439 case AF_APPLETALK: 440 etype = ETHERTYPE_ATALK; 441 break; 442 #endif 443 default: 444 _IF_DROP(&ifp->if_snd); 445 m_freem(m); 446 error = EAFNOSUPPORT; 447 goto end; 448 } 449 450 /* Reserve space for GRE header + optional GRE key */ 451 int hdrlen = sizeof(struct greip) + extra; 452 if (sc->key) 453 hdrlen += sizeof(uint32_t); 454 M_PREPEND(m, hdrlen, M_NOWAIT); 455 } else { 456 _IF_DROP(&ifp->if_snd); 457 m_freem(m); 458 error = EINVAL; 459 goto end; 460 } 461 462 if (m == NULL) { /* mbuf allocation failed */ 463 _IF_DROP(&ifp->if_snd); 464 error = ENOBUFS; 465 goto end; 466 } 467 468 M_SETFIB(m, sc->gre_fibnum); /* The envelope may use a different FIB */ 469 470 gh = mtod(m, struct greip *); 471 if (sc->g_proto == IPPROTO_GRE) { 472 uint32_t *options = gh->gi_options; 473 474 memset((void *)gh, 0, sizeof(struct greip) + extra); 475 gh->gi_ptype = htons(etype); 476 gh->gi_flags = 0; 477 478 /* Add key option */ 479 if (sc->key) 480 { 481 gh->gi_flags |= htons(GRE_KP); 482 *(options++) = htonl(sc->key); 483 } 484 } 485 486 gh->gi_pr = sc->g_proto; 487 if (sc->g_proto != IPPROTO_MOBILE) { 488 gh->gi_src = sc->g_src; 489 gh->gi_dst = sc->g_dst; 490 ((struct ip*)gh)->ip_v = IPPROTO_IPV4; 491 ((struct ip*)gh)->ip_hl = (sizeof(struct ip)) >> 2; 492 ((struct ip*)gh)->ip_ttl = GRE_TTL; 493 ((struct ip*)gh)->ip_tos = gre_ip_tos; 494 ((struct ip*)gh)->ip_id = gre_ip_id; 495 gh->gi_len = htons(m->m_pkthdr.len); 496 } 497 498 ifp->if_opackets++; 499 ifp->if_obytes += m->m_pkthdr.len; 500 /* 501 * Send it off and with IP_FORWARD flag to prevent it from 502 * overwriting the ip_id again. ip_id is already set to the 503 * ip_id of the encapsulated packet. 504 */ 505 error = ip_output(m, NULL, &sc->route, IP_FORWARDING, 506 (struct ip_moptions *)NULL, (struct inpcb *)NULL); 507 end: 508 if (error) 509 ifp->if_oerrors++; 510 return (error); 511 } 512 513 static int 514 gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 515 { 516 struct ifreq *ifr = (struct ifreq *)data; 517 struct if_laddrreq *lifr = (struct if_laddrreq *)data; 518 struct in_aliasreq *aifr = (struct in_aliasreq *)data; 519 struct gre_softc *sc = ifp->if_softc; 520 struct sockaddr_in si; 521 struct sockaddr *sa = NULL; 522 int error, adj; 523 struct sockaddr_in sp, sm, dp, dm; 524 uint32_t key; 525 526 error = 0; 527 adj = 0; 528 529 switch (cmd) { 530 case SIOCSIFADDR: 531 ifp->if_flags |= IFF_UP; 532 break; 533 case SIOCSIFDSTADDR: 534 break; 535 case SIOCSIFFLAGS: 536 /* 537 * XXXRW: Isn't this priv_check() redundant to the ifnet 538 * layer check? 539 */ 540 if ((error = priv_check(curthread, PRIV_NET_SETIFFLAGS)) != 0) 541 break; 542 if ((ifr->ifr_flags & IFF_LINK0) != 0) 543 sc->g_proto = IPPROTO_GRE; 544 else 545 sc->g_proto = IPPROTO_MOBILE; 546 if ((ifr->ifr_flags & IFF_LINK2) != 0) 547 sc->wccp_ver = WCCP_V2; 548 else 549 sc->wccp_ver = WCCP_V1; 550 goto recompute; 551 case SIOCSIFMTU: 552 /* 553 * XXXRW: Isn't this priv_check() redundant to the ifnet 554 * layer check? 555 */ 556 if ((error = priv_check(curthread, PRIV_NET_SETIFMTU)) != 0) 557 break; 558 if (ifr->ifr_mtu < 576) { 559 error = EINVAL; 560 break; 561 } 562 ifp->if_mtu = ifr->ifr_mtu; 563 break; 564 case SIOCGIFMTU: 565 ifr->ifr_mtu = GRE2IFP(sc)->if_mtu; 566 break; 567 case SIOCADDMULTI: 568 /* 569 * XXXRW: Isn't this priv_checkr() redundant to the ifnet 570 * layer check? 571 */ 572 if ((error = priv_check(curthread, PRIV_NET_ADDMULTI)) != 0) 573 break; 574 if (ifr == 0) { 575 error = EAFNOSUPPORT; 576 break; 577 } 578 switch (ifr->ifr_addr.sa_family) { 579 #ifdef INET 580 case AF_INET: 581 break; 582 #endif 583 #ifdef INET6 584 case AF_INET6: 585 break; 586 #endif 587 default: 588 error = EAFNOSUPPORT; 589 break; 590 } 591 break; 592 case SIOCDELMULTI: 593 /* 594 * XXXRW: Isn't this priv_check() redundant to the ifnet 595 * layer check? 596 */ 597 if ((error = priv_check(curthread, PRIV_NET_DELIFGROUP)) != 0) 598 break; 599 if (ifr == 0) { 600 error = EAFNOSUPPORT; 601 break; 602 } 603 switch (ifr->ifr_addr.sa_family) { 604 #ifdef INET 605 case AF_INET: 606 break; 607 #endif 608 #ifdef INET6 609 case AF_INET6: 610 break; 611 #endif 612 default: 613 error = EAFNOSUPPORT; 614 break; 615 } 616 break; 617 case GRESPROTO: 618 /* 619 * XXXRW: Isn't this priv_check() redundant to the ifnet 620 * layer check? 621 */ 622 if ((error = priv_check(curthread, PRIV_NET_GRE)) != 0) 623 break; 624 sc->g_proto = ifr->ifr_flags; 625 switch (sc->g_proto) { 626 case IPPROTO_GRE: 627 ifp->if_flags |= IFF_LINK0; 628 break; 629 case IPPROTO_MOBILE: 630 ifp->if_flags &= ~IFF_LINK0; 631 break; 632 default: 633 error = EPROTONOSUPPORT; 634 break; 635 } 636 goto recompute; 637 case GREGPROTO: 638 ifr->ifr_flags = sc->g_proto; 639 break; 640 case GRESADDRS: 641 case GRESADDRD: 642 error = priv_check(curthread, PRIV_NET_GRE); 643 if (error) 644 return (error); 645 /* 646 * set tunnel endpoints, compute a less specific route 647 * to the remote end and mark if as up 648 */ 649 sa = &ifr->ifr_addr; 650 if (cmd == GRESADDRS) 651 sc->g_src = (satosin(sa))->sin_addr; 652 if (cmd == GRESADDRD) 653 sc->g_dst = (satosin(sa))->sin_addr; 654 recompute: 655 #ifdef INET 656 if (sc->encap != NULL) { 657 encap_detach(sc->encap); 658 sc->encap = NULL; 659 } 660 #endif 661 if ((sc->g_src.s_addr != INADDR_ANY) && 662 (sc->g_dst.s_addr != INADDR_ANY)) { 663 bzero(&sp, sizeof(sp)); 664 bzero(&sm, sizeof(sm)); 665 bzero(&dp, sizeof(dp)); 666 bzero(&dm, sizeof(dm)); 667 sp.sin_len = sm.sin_len = dp.sin_len = dm.sin_len = 668 sizeof(struct sockaddr_in); 669 sp.sin_family = sm.sin_family = dp.sin_family = 670 dm.sin_family = AF_INET; 671 sp.sin_addr = sc->g_src; 672 dp.sin_addr = sc->g_dst; 673 sm.sin_addr.s_addr = dm.sin_addr.s_addr = 674 INADDR_BROADCAST; 675 #ifdef INET 676 sc->encap = encap_attach(AF_INET, sc->g_proto, 677 sintosa(&sp), sintosa(&sm), sintosa(&dp), 678 sintosa(&dm), (sc->g_proto == IPPROTO_GRE) ? 679 &in_gre_protosw : &in_mobile_protosw, sc); 680 if (sc->encap == NULL) 681 printf("%s: unable to attach encap\n", 682 if_name(GRE2IFP(sc))); 683 #endif 684 if (sc->route.ro_rt != 0) /* free old route */ 685 RTFREE(sc->route.ro_rt); 686 if (gre_compute_route(sc) == 0) 687 ifp->if_drv_flags |= IFF_DRV_RUNNING; 688 else 689 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 690 } 691 break; 692 case GREGADDRS: 693 memset(&si, 0, sizeof(si)); 694 si.sin_family = AF_INET; 695 si.sin_len = sizeof(struct sockaddr_in); 696 si.sin_addr.s_addr = sc->g_src.s_addr; 697 sa = sintosa(&si); 698 error = prison_if(curthread->td_ucred, sa); 699 if (error != 0) 700 break; 701 ifr->ifr_addr = *sa; 702 break; 703 case GREGADDRD: 704 memset(&si, 0, sizeof(si)); 705 si.sin_family = AF_INET; 706 si.sin_len = sizeof(struct sockaddr_in); 707 si.sin_addr.s_addr = sc->g_dst.s_addr; 708 sa = sintosa(&si); 709 error = prison_if(curthread->td_ucred, sa); 710 if (error != 0) 711 break; 712 ifr->ifr_addr = *sa; 713 break; 714 case SIOCSIFPHYADDR: 715 /* 716 * XXXRW: Isn't this priv_check() redundant to the ifnet 717 * layer check? 718 */ 719 if ((error = priv_check(curthread, PRIV_NET_SETIFPHYS)) != 0) 720 break; 721 if (aifr->ifra_addr.sin_family != AF_INET || 722 aifr->ifra_dstaddr.sin_family != AF_INET) { 723 error = EAFNOSUPPORT; 724 break; 725 } 726 if (aifr->ifra_addr.sin_len != sizeof(si) || 727 aifr->ifra_dstaddr.sin_len != sizeof(si)) { 728 error = EINVAL; 729 break; 730 } 731 sc->g_src = aifr->ifra_addr.sin_addr; 732 sc->g_dst = aifr->ifra_dstaddr.sin_addr; 733 goto recompute; 734 case SIOCSLIFPHYADDR: 735 /* 736 * XXXRW: Isn't this priv_check() redundant to the ifnet 737 * layer check? 738 */ 739 if ((error = priv_check(curthread, PRIV_NET_SETIFPHYS)) != 0) 740 break; 741 if (lifr->addr.ss_family != AF_INET || 742 lifr->dstaddr.ss_family != AF_INET) { 743 error = EAFNOSUPPORT; 744 break; 745 } 746 if (lifr->addr.ss_len != sizeof(si) || 747 lifr->dstaddr.ss_len != sizeof(si)) { 748 error = EINVAL; 749 break; 750 } 751 sc->g_src = (satosin(&lifr->addr))->sin_addr; 752 sc->g_dst = 753 (satosin(&lifr->dstaddr))->sin_addr; 754 goto recompute; 755 case SIOCDIFPHYADDR: 756 /* 757 * XXXRW: Isn't this priv_check() redundant to the ifnet 758 * layer check? 759 */ 760 if ((error = priv_check(curthread, PRIV_NET_SETIFPHYS)) != 0) 761 break; 762 sc->g_src.s_addr = INADDR_ANY; 763 sc->g_dst.s_addr = INADDR_ANY; 764 goto recompute; 765 case SIOCGLIFPHYADDR: 766 if (sc->g_src.s_addr == INADDR_ANY || 767 sc->g_dst.s_addr == INADDR_ANY) { 768 error = EADDRNOTAVAIL; 769 break; 770 } 771 memset(&si, 0, sizeof(si)); 772 si.sin_family = AF_INET; 773 si.sin_len = sizeof(struct sockaddr_in); 774 si.sin_addr.s_addr = sc->g_src.s_addr; 775 error = prison_if(curthread->td_ucred, (struct sockaddr *)&si); 776 if (error != 0) 777 break; 778 memcpy(&lifr->addr, &si, sizeof(si)); 779 si.sin_addr.s_addr = sc->g_dst.s_addr; 780 error = prison_if(curthread->td_ucred, (struct sockaddr *)&si); 781 if (error != 0) 782 break; 783 memcpy(&lifr->dstaddr, &si, sizeof(si)); 784 break; 785 case SIOCGIFPSRCADDR: 786 #ifdef INET6 787 case SIOCGIFPSRCADDR_IN6: 788 #endif 789 if (sc->g_src.s_addr == INADDR_ANY) { 790 error = EADDRNOTAVAIL; 791 break; 792 } 793 memset(&si, 0, sizeof(si)); 794 si.sin_family = AF_INET; 795 si.sin_len = sizeof(struct sockaddr_in); 796 si.sin_addr.s_addr = sc->g_src.s_addr; 797 error = prison_if(curthread->td_ucred, (struct sockaddr *)&si); 798 if (error != 0) 799 break; 800 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr)); 801 break; 802 case SIOCGIFPDSTADDR: 803 #ifdef INET6 804 case SIOCGIFPDSTADDR_IN6: 805 #endif 806 if (sc->g_dst.s_addr == INADDR_ANY) { 807 error = EADDRNOTAVAIL; 808 break; 809 } 810 memset(&si, 0, sizeof(si)); 811 si.sin_family = AF_INET; 812 si.sin_len = sizeof(struct sockaddr_in); 813 si.sin_addr.s_addr = sc->g_dst.s_addr; 814 error = prison_if(curthread->td_ucred, (struct sockaddr *)&si); 815 if (error != 0) 816 break; 817 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr)); 818 break; 819 case GRESKEY: 820 error = priv_check(curthread, PRIV_NET_GRE); 821 if (error) 822 break; 823 error = copyin(ifr->ifr_data, &key, sizeof(key)); 824 if (error) 825 break; 826 /* adjust MTU for option header */ 827 if (key == 0 && sc->key != 0) /* clear */ 828 adj += sizeof(key); 829 else if (key != 0 && sc->key == 0) /* set */ 830 adj -= sizeof(key); 831 832 if (ifp->if_mtu + adj < 576) { 833 error = EINVAL; 834 break; 835 } 836 ifp->if_mtu += adj; 837 sc->key = key; 838 break; 839 case GREGKEY: 840 error = copyout(&sc->key, ifr->ifr_data, sizeof(sc->key)); 841 break; 842 843 default: 844 error = EINVAL; 845 break; 846 } 847 848 return (error); 849 } 850 851 /* 852 * computes a route to our destination that is not the one 853 * which would be taken by ip_output(), as this one will loop back to 854 * us. If the interface is p2p as a--->b, then a routing entry exists 855 * If we now send a packet to b (e.g. ping b), this will come down here 856 * gets src=a, dst=b tacked on and would from ip_output() sent back to 857 * if_gre. 858 * Goal here is to compute a route to b that is less specific than 859 * a-->b. We know that this one exists as in normal operation we have 860 * at least a default route which matches. 861 */ 862 static int 863 gre_compute_route(struct gre_softc *sc) 864 { 865 struct route *ro; 866 867 ro = &sc->route; 868 869 memset(ro, 0, sizeof(struct route)); 870 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst; 871 ro->ro_dst.sa_family = AF_INET; 872 ro->ro_dst.sa_len = sizeof(ro->ro_dst); 873 874 /* 875 * toggle last bit, so our interface is not found, but a less 876 * specific route. I'd rather like to specify a shorter mask, 877 * but this is not possible. Should work though. XXX 878 * XXX MRT Use a different FIB for the tunnel to solve this problem. 879 */ 880 if ((GRE2IFP(sc)->if_flags & IFF_LINK1) == 0) { 881 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr.s_addr ^= 882 htonl(0x01); 883 } 884 885 #ifdef DIAGNOSTIC 886 printf("%s: searching for a route to %s", if_name(GRE2IFP(sc)), 887 inet_ntoa(((struct sockaddr_in *)&ro->ro_dst)->sin_addr)); 888 #endif 889 890 rtalloc_fib(ro, sc->gre_fibnum); 891 892 /* 893 * check if this returned a route at all and this route is no 894 * recursion to ourself 895 */ 896 if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp->if_softc == sc) { 897 #ifdef DIAGNOSTIC 898 if (ro->ro_rt == NULL) 899 printf(" - no route found!\n"); 900 else 901 printf(" - route loops back to ourself!\n"); 902 #endif 903 return EADDRNOTAVAIL; 904 } 905 906 /* 907 * now change it back - else ip_output will just drop 908 * the route and search one to this interface ... 909 */ 910 if ((GRE2IFP(sc)->if_flags & IFF_LINK1) == 0) 911 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst; 912 913 #ifdef DIAGNOSTIC 914 printf(", choosing %s with gateway %s", if_name(ro->ro_rt->rt_ifp), 915 inet_ntoa(((struct sockaddr_in *)(ro->ro_rt->rt_gateway))->sin_addr)); 916 printf("\n"); 917 #endif 918 919 return 0; 920 } 921 922 /* 923 * do a checksum of a buffer - much like in_cksum, which operates on 924 * mbufs. 925 */ 926 u_int16_t 927 gre_in_cksum(u_int16_t *p, u_int len) 928 { 929 u_int32_t sum = 0; 930 int nwords = len >> 1; 931 932 while (nwords-- != 0) 933 sum += *p++; 934 935 if (len & 1) { 936 union { 937 u_short w; 938 u_char c[2]; 939 } u; 940 u.c[0] = *(u_char *)p; 941 u.c[1] = 0; 942 sum += u.w; 943 } 944 945 /* end-around-carry */ 946 sum = (sum >> 16) + (sum & 0xffff); 947 sum += (sum >> 16); 948 return (~sum); 949 } 950 951 static int 952 gremodevent(module_t mod, int type, void *data) 953 { 954 955 switch (type) { 956 case MOD_LOAD: 957 greattach(); 958 break; 959 case MOD_UNLOAD: 960 if_clone_detach(gre_cloner); 961 mtx_destroy(&gre_mtx); 962 break; 963 default: 964 return EOPNOTSUPP; 965 } 966 return 0; 967 } 968 969 static moduledata_t gre_mod = { 970 "if_gre", 971 gremodevent, 972 0 973 }; 974 975 DECLARE_MODULE(if_gre, gre_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 976 MODULE_VERSION(if_gre, 1); 977