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 *, 117 const struct sockaddr *, struct route *); 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, const 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 else 339 af = dst->sa_family; 340 341 if (bpf_peers_present(ifp->if_bpf)) 342 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 343 344 if ((ifp->if_flags & IFF_MONITOR) != 0) { 345 m_freem(m); 346 error = ENETDOWN; 347 goto end; 348 } 349 350 m->m_flags &= ~(M_BCAST|M_MCAST); 351 352 if (sc->g_proto == IPPROTO_MOBILE) { 353 if (af == AF_INET) { 354 struct mbuf *m0; 355 int msiz; 356 357 ip = mtod(m, struct ip *); 358 359 /* 360 * RFC2004 specifies that fragmented diagrams shouldn't 361 * be encapsulated. 362 */ 363 if (ip->ip_off & htons(IP_MF | IP_OFFMASK)) { 364 _IF_DROP(&ifp->if_snd); 365 m_freem(m); 366 error = EINVAL; /* is there better errno? */ 367 goto end; 368 } 369 memset(&mob_h, 0, MOB_H_SIZ_L); 370 mob_h.proto = (ip->ip_p) << 8; 371 mob_h.odst = ip->ip_dst.s_addr; 372 ip->ip_dst.s_addr = sc->g_dst.s_addr; 373 374 /* 375 * If the packet comes from our host, we only change 376 * the destination address in the IP header. 377 * Else we also need to save and change the source 378 */ 379 if (in_hosteq(ip->ip_src, sc->g_src)) { 380 msiz = MOB_H_SIZ_S; 381 } else { 382 mob_h.proto |= MOB_H_SBIT; 383 mob_h.osrc = ip->ip_src.s_addr; 384 ip->ip_src.s_addr = sc->g_src.s_addr; 385 msiz = MOB_H_SIZ_L; 386 } 387 mob_h.proto = htons(mob_h.proto); 388 mob_h.hcrc = gre_in_cksum((u_int16_t *)&mob_h, msiz); 389 390 if ((m->m_data - msiz) < m->m_pktdat) { 391 m0 = m_gethdr(M_NOWAIT, MT_DATA); 392 if (m0 == NULL) { 393 _IF_DROP(&ifp->if_snd); 394 m_freem(m); 395 error = ENOBUFS; 396 goto end; 397 } 398 m0->m_next = m; 399 m->m_data += sizeof(struct ip); 400 m->m_len -= sizeof(struct ip); 401 m0->m_pkthdr.len = m->m_pkthdr.len + msiz; 402 m0->m_len = msiz + sizeof(struct ip); 403 m0->m_data += max_linkhdr; 404 memcpy(mtod(m0, caddr_t), (caddr_t)ip, 405 sizeof(struct ip)); 406 m = m0; 407 } else { /* we have some space left in the old one */ 408 m->m_data -= msiz; 409 m->m_len += msiz; 410 m->m_pkthdr.len += msiz; 411 bcopy(ip, mtod(m, caddr_t), 412 sizeof(struct ip)); 413 } 414 ip = mtod(m, struct ip *); 415 memcpy((caddr_t)(ip + 1), &mob_h, (unsigned)msiz); 416 ip->ip_len = htons(ntohs(ip->ip_len) + msiz); 417 } else { /* AF_INET */ 418 _IF_DROP(&ifp->if_snd); 419 m_freem(m); 420 error = EINVAL; 421 goto end; 422 } 423 } else if (sc->g_proto == IPPROTO_GRE) { 424 switch (af) { 425 case AF_INET: 426 ip = mtod(m, struct ip *); 427 gre_ip_tos = ip->ip_tos; 428 gre_ip_id = ip->ip_id; 429 if (sc->wccp_ver == WCCP_V2) { 430 extra = sizeof(uint32_t); 431 etype = WCCP_PROTOCOL_TYPE; 432 } else { 433 etype = ETHERTYPE_IP; 434 } 435 break; 436 #ifdef INET6 437 case AF_INET6: 438 gre_ip_id = ip_newid(); 439 etype = ETHERTYPE_IPV6; 440 break; 441 #endif 442 #ifdef NETATALK 443 case AF_APPLETALK: 444 etype = ETHERTYPE_ATALK; 445 break; 446 #endif 447 default: 448 _IF_DROP(&ifp->if_snd); 449 m_freem(m); 450 error = EAFNOSUPPORT; 451 goto end; 452 } 453 454 /* Reserve space for GRE header + optional GRE key */ 455 int hdrlen = sizeof(struct greip) + extra; 456 if (sc->key) 457 hdrlen += sizeof(uint32_t); 458 M_PREPEND(m, hdrlen, M_NOWAIT); 459 } else { 460 _IF_DROP(&ifp->if_snd); 461 m_freem(m); 462 error = EINVAL; 463 goto end; 464 } 465 466 if (m == NULL) { /* mbuf allocation failed */ 467 _IF_DROP(&ifp->if_snd); 468 error = ENOBUFS; 469 goto end; 470 } 471 472 M_SETFIB(m, sc->gre_fibnum); /* The envelope may use a different FIB */ 473 474 gh = mtod(m, struct greip *); 475 if (sc->g_proto == IPPROTO_GRE) { 476 uint32_t *options = gh->gi_options; 477 478 memset((void *)gh, 0, sizeof(struct greip) + extra); 479 gh->gi_ptype = htons(etype); 480 gh->gi_flags = 0; 481 482 /* Add key option */ 483 if (sc->key) 484 { 485 gh->gi_flags |= htons(GRE_KP); 486 *(options++) = htonl(sc->key); 487 } 488 } 489 490 gh->gi_pr = sc->g_proto; 491 if (sc->g_proto != IPPROTO_MOBILE) { 492 gh->gi_src = sc->g_src; 493 gh->gi_dst = sc->g_dst; 494 ((struct ip*)gh)->ip_v = IPPROTO_IPV4; 495 ((struct ip*)gh)->ip_hl = (sizeof(struct ip)) >> 2; 496 ((struct ip*)gh)->ip_ttl = GRE_TTL; 497 ((struct ip*)gh)->ip_tos = gre_ip_tos; 498 ((struct ip*)gh)->ip_id = gre_ip_id; 499 gh->gi_len = htons(m->m_pkthdr.len); 500 } 501 502 ifp->if_opackets++; 503 ifp->if_obytes += m->m_pkthdr.len; 504 /* 505 * Send it off and with IP_FORWARD flag to prevent it from 506 * overwriting the ip_id again. ip_id is already set to the 507 * ip_id of the encapsulated packet. 508 */ 509 error = ip_output(m, NULL, &sc->route, IP_FORWARDING, 510 (struct ip_moptions *)NULL, (struct inpcb *)NULL); 511 end: 512 if (error) 513 ifp->if_oerrors++; 514 return (error); 515 } 516 517 static int 518 gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 519 { 520 struct ifreq *ifr = (struct ifreq *)data; 521 struct if_laddrreq *lifr = (struct if_laddrreq *)data; 522 struct in_aliasreq *aifr = (struct in_aliasreq *)data; 523 struct gre_softc *sc = ifp->if_softc; 524 struct sockaddr_in si; 525 struct sockaddr *sa = NULL; 526 int error, adj; 527 struct sockaddr_in sp, sm, dp, dm; 528 uint32_t key; 529 530 error = 0; 531 adj = 0; 532 533 switch (cmd) { 534 case SIOCSIFADDR: 535 ifp->if_flags |= IFF_UP; 536 break; 537 case SIOCSIFFLAGS: 538 /* 539 * XXXRW: Isn't this priv_check() redundant to the ifnet 540 * layer check? 541 */ 542 if ((error = priv_check(curthread, PRIV_NET_SETIFFLAGS)) != 0) 543 break; 544 if ((ifr->ifr_flags & IFF_LINK0) != 0) 545 sc->g_proto = IPPROTO_GRE; 546 else 547 sc->g_proto = IPPROTO_MOBILE; 548 if ((ifr->ifr_flags & IFF_LINK2) != 0) 549 sc->wccp_ver = WCCP_V2; 550 else 551 sc->wccp_ver = WCCP_V1; 552 goto recompute; 553 case SIOCSIFMTU: 554 /* 555 * XXXRW: Isn't this priv_check() redundant to the ifnet 556 * layer check? 557 */ 558 if ((error = priv_check(curthread, PRIV_NET_SETIFMTU)) != 0) 559 break; 560 if (ifr->ifr_mtu < 576) { 561 error = EINVAL; 562 break; 563 } 564 ifp->if_mtu = ifr->ifr_mtu; 565 break; 566 case SIOCGIFMTU: 567 ifr->ifr_mtu = GRE2IFP(sc)->if_mtu; 568 break; 569 case SIOCADDMULTI: 570 /* 571 * XXXRW: Isn't this priv_checkr() redundant to the ifnet 572 * layer check? 573 */ 574 if ((error = priv_check(curthread, PRIV_NET_ADDMULTI)) != 0) 575 break; 576 if (ifr == 0) { 577 error = EAFNOSUPPORT; 578 break; 579 } 580 switch (ifr->ifr_addr.sa_family) { 581 #ifdef INET 582 case AF_INET: 583 break; 584 #endif 585 #ifdef INET6 586 case AF_INET6: 587 break; 588 #endif 589 default: 590 error = EAFNOSUPPORT; 591 break; 592 } 593 break; 594 case SIOCDELMULTI: 595 /* 596 * XXXRW: Isn't this priv_check() redundant to the ifnet 597 * layer check? 598 */ 599 if ((error = priv_check(curthread, PRIV_NET_DELIFGROUP)) != 0) 600 break; 601 if (ifr == 0) { 602 error = EAFNOSUPPORT; 603 break; 604 } 605 switch (ifr->ifr_addr.sa_family) { 606 #ifdef INET 607 case AF_INET: 608 break; 609 #endif 610 #ifdef INET6 611 case AF_INET6: 612 break; 613 #endif 614 default: 615 error = EAFNOSUPPORT; 616 break; 617 } 618 break; 619 case GRESPROTO: 620 /* 621 * XXXRW: Isn't this priv_check() redundant to the ifnet 622 * layer check? 623 */ 624 if ((error = priv_check(curthread, PRIV_NET_GRE)) != 0) 625 break; 626 sc->g_proto = ifr->ifr_flags; 627 switch (sc->g_proto) { 628 case IPPROTO_GRE: 629 ifp->if_flags |= IFF_LINK0; 630 break; 631 case IPPROTO_MOBILE: 632 ifp->if_flags &= ~IFF_LINK0; 633 break; 634 default: 635 error = EPROTONOSUPPORT; 636 break; 637 } 638 goto recompute; 639 case GREGPROTO: 640 ifr->ifr_flags = sc->g_proto; 641 break; 642 case GRESADDRS: 643 case GRESADDRD: 644 error = priv_check(curthread, PRIV_NET_GRE); 645 if (error) 646 return (error); 647 /* 648 * set tunnel endpoints, compute a less specific route 649 * to the remote end and mark if as up 650 */ 651 sa = &ifr->ifr_addr; 652 if (cmd == GRESADDRS) 653 sc->g_src = (satosin(sa))->sin_addr; 654 if (cmd == GRESADDRD) 655 sc->g_dst = (satosin(sa))->sin_addr; 656 recompute: 657 #ifdef INET 658 if (sc->encap != NULL) { 659 encap_detach(sc->encap); 660 sc->encap = NULL; 661 } 662 #endif 663 if ((sc->g_src.s_addr != INADDR_ANY) && 664 (sc->g_dst.s_addr != INADDR_ANY)) { 665 bzero(&sp, sizeof(sp)); 666 bzero(&sm, sizeof(sm)); 667 bzero(&dp, sizeof(dp)); 668 bzero(&dm, sizeof(dm)); 669 sp.sin_len = sm.sin_len = dp.sin_len = dm.sin_len = 670 sizeof(struct sockaddr_in); 671 sp.sin_family = sm.sin_family = dp.sin_family = 672 dm.sin_family = AF_INET; 673 sp.sin_addr = sc->g_src; 674 dp.sin_addr = sc->g_dst; 675 sm.sin_addr.s_addr = dm.sin_addr.s_addr = 676 INADDR_BROADCAST; 677 #ifdef INET 678 sc->encap = encap_attach(AF_INET, sc->g_proto, 679 sintosa(&sp), sintosa(&sm), sintosa(&dp), 680 sintosa(&dm), (sc->g_proto == IPPROTO_GRE) ? 681 &in_gre_protosw : &in_mobile_protosw, sc); 682 if (sc->encap == NULL) 683 printf("%s: unable to attach encap\n", 684 if_name(GRE2IFP(sc))); 685 #endif 686 if (sc->route.ro_rt != 0) /* free old route */ 687 RTFREE(sc->route.ro_rt); 688 if (gre_compute_route(sc) == 0) 689 ifp->if_drv_flags |= IFF_DRV_RUNNING; 690 else 691 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 692 } 693 break; 694 case GREGADDRS: 695 memset(&si, 0, sizeof(si)); 696 si.sin_family = AF_INET; 697 si.sin_len = sizeof(struct sockaddr_in); 698 si.sin_addr.s_addr = sc->g_src.s_addr; 699 sa = sintosa(&si); 700 error = prison_if(curthread->td_ucred, sa); 701 if (error != 0) 702 break; 703 ifr->ifr_addr = *sa; 704 break; 705 case GREGADDRD: 706 memset(&si, 0, sizeof(si)); 707 si.sin_family = AF_INET; 708 si.sin_len = sizeof(struct sockaddr_in); 709 si.sin_addr.s_addr = sc->g_dst.s_addr; 710 sa = sintosa(&si); 711 error = prison_if(curthread->td_ucred, sa); 712 if (error != 0) 713 break; 714 ifr->ifr_addr = *sa; 715 break; 716 case SIOCSIFPHYADDR: 717 /* 718 * XXXRW: Isn't this priv_check() redundant to the ifnet 719 * layer check? 720 */ 721 if ((error = priv_check(curthread, PRIV_NET_SETIFPHYS)) != 0) 722 break; 723 if (aifr->ifra_addr.sin_family != AF_INET || 724 aifr->ifra_dstaddr.sin_family != AF_INET) { 725 error = EAFNOSUPPORT; 726 break; 727 } 728 if (aifr->ifra_addr.sin_len != sizeof(si) || 729 aifr->ifra_dstaddr.sin_len != sizeof(si)) { 730 error = EINVAL; 731 break; 732 } 733 sc->g_src = aifr->ifra_addr.sin_addr; 734 sc->g_dst = aifr->ifra_dstaddr.sin_addr; 735 goto recompute; 736 case SIOCSLIFPHYADDR: 737 /* 738 * XXXRW: Isn't this priv_check() redundant to the ifnet 739 * layer check? 740 */ 741 if ((error = priv_check(curthread, PRIV_NET_SETIFPHYS)) != 0) 742 break; 743 if (lifr->addr.ss_family != AF_INET || 744 lifr->dstaddr.ss_family != AF_INET) { 745 error = EAFNOSUPPORT; 746 break; 747 } 748 if (lifr->addr.ss_len != sizeof(si) || 749 lifr->dstaddr.ss_len != sizeof(si)) { 750 error = EINVAL; 751 break; 752 } 753 sc->g_src = (satosin(&lifr->addr))->sin_addr; 754 sc->g_dst = 755 (satosin(&lifr->dstaddr))->sin_addr; 756 goto recompute; 757 case SIOCDIFPHYADDR: 758 /* 759 * XXXRW: Isn't this priv_check() redundant to the ifnet 760 * layer check? 761 */ 762 if ((error = priv_check(curthread, PRIV_NET_SETIFPHYS)) != 0) 763 break; 764 sc->g_src.s_addr = INADDR_ANY; 765 sc->g_dst.s_addr = INADDR_ANY; 766 goto recompute; 767 case SIOCGLIFPHYADDR: 768 if (sc->g_src.s_addr == INADDR_ANY || 769 sc->g_dst.s_addr == INADDR_ANY) { 770 error = EADDRNOTAVAIL; 771 break; 772 } 773 memset(&si, 0, sizeof(si)); 774 si.sin_family = AF_INET; 775 si.sin_len = sizeof(struct sockaddr_in); 776 si.sin_addr.s_addr = sc->g_src.s_addr; 777 error = prison_if(curthread->td_ucred, (struct sockaddr *)&si); 778 if (error != 0) 779 break; 780 memcpy(&lifr->addr, &si, sizeof(si)); 781 si.sin_addr.s_addr = sc->g_dst.s_addr; 782 error = prison_if(curthread->td_ucred, (struct sockaddr *)&si); 783 if (error != 0) 784 break; 785 memcpy(&lifr->dstaddr, &si, sizeof(si)); 786 break; 787 case SIOCGIFPSRCADDR: 788 #ifdef INET6 789 case SIOCGIFPSRCADDR_IN6: 790 #endif 791 if (sc->g_src.s_addr == INADDR_ANY) { 792 error = EADDRNOTAVAIL; 793 break; 794 } 795 memset(&si, 0, sizeof(si)); 796 si.sin_family = AF_INET; 797 si.sin_len = sizeof(struct sockaddr_in); 798 si.sin_addr.s_addr = sc->g_src.s_addr; 799 error = prison_if(curthread->td_ucred, (struct sockaddr *)&si); 800 if (error != 0) 801 break; 802 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr)); 803 break; 804 case SIOCGIFPDSTADDR: 805 #ifdef INET6 806 case SIOCGIFPDSTADDR_IN6: 807 #endif 808 if (sc->g_dst.s_addr == INADDR_ANY) { 809 error = EADDRNOTAVAIL; 810 break; 811 } 812 memset(&si, 0, sizeof(si)); 813 si.sin_family = AF_INET; 814 si.sin_len = sizeof(struct sockaddr_in); 815 si.sin_addr.s_addr = sc->g_dst.s_addr; 816 error = prison_if(curthread->td_ucred, (struct sockaddr *)&si); 817 if (error != 0) 818 break; 819 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr)); 820 break; 821 case GRESKEY: 822 error = priv_check(curthread, PRIV_NET_GRE); 823 if (error) 824 break; 825 error = copyin(ifr->ifr_data, &key, sizeof(key)); 826 if (error) 827 break; 828 /* adjust MTU for option header */ 829 if (key == 0 && sc->key != 0) /* clear */ 830 adj += sizeof(key); 831 else if (key != 0 && sc->key == 0) /* set */ 832 adj -= sizeof(key); 833 834 if (ifp->if_mtu + adj < 576) { 835 error = EINVAL; 836 break; 837 } 838 ifp->if_mtu += adj; 839 sc->key = key; 840 break; 841 case GREGKEY: 842 error = copyout(&sc->key, ifr->ifr_data, sizeof(sc->key)); 843 break; 844 845 default: 846 error = EINVAL; 847 break; 848 } 849 850 return (error); 851 } 852 853 /* 854 * computes a route to our destination that is not the one 855 * which would be taken by ip_output(), as this one will loop back to 856 * us. If the interface is p2p as a--->b, then a routing entry exists 857 * If we now send a packet to b (e.g. ping b), this will come down here 858 * gets src=a, dst=b tacked on and would from ip_output() sent back to 859 * if_gre. 860 * Goal here is to compute a route to b that is less specific than 861 * a-->b. We know that this one exists as in normal operation we have 862 * at least a default route which matches. 863 */ 864 static int 865 gre_compute_route(struct gre_softc *sc) 866 { 867 struct route *ro; 868 869 ro = &sc->route; 870 871 memset(ro, 0, sizeof(struct route)); 872 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst; 873 ro->ro_dst.sa_family = AF_INET; 874 ro->ro_dst.sa_len = sizeof(ro->ro_dst); 875 876 /* 877 * toggle last bit, so our interface is not found, but a less 878 * specific route. I'd rather like to specify a shorter mask, 879 * but this is not possible. Should work though. XXX 880 * XXX MRT Use a different FIB for the tunnel to solve this problem. 881 */ 882 if ((GRE2IFP(sc)->if_flags & IFF_LINK1) == 0) { 883 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr.s_addr ^= 884 htonl(0x01); 885 } 886 887 #ifdef DIAGNOSTIC 888 printf("%s: searching for a route to %s", if_name(GRE2IFP(sc)), 889 inet_ntoa(((struct sockaddr_in *)&ro->ro_dst)->sin_addr)); 890 #endif 891 892 rtalloc_fib(ro, sc->gre_fibnum); 893 894 /* 895 * check if this returned a route at all and this route is no 896 * recursion to ourself 897 */ 898 if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp->if_softc == sc) { 899 #ifdef DIAGNOSTIC 900 if (ro->ro_rt == NULL) 901 printf(" - no route found!\n"); 902 else 903 printf(" - route loops back to ourself!\n"); 904 #endif 905 return EADDRNOTAVAIL; 906 } 907 908 /* 909 * now change it back - else ip_output will just drop 910 * the route and search one to this interface ... 911 */ 912 if ((GRE2IFP(sc)->if_flags & IFF_LINK1) == 0) 913 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst; 914 915 #ifdef DIAGNOSTIC 916 printf(", choosing %s with gateway %s", if_name(ro->ro_rt->rt_ifp), 917 inet_ntoa(((struct sockaddr_in *)(ro->ro_rt->rt_gateway))->sin_addr)); 918 printf("\n"); 919 #endif 920 921 return 0; 922 } 923 924 /* 925 * do a checksum of a buffer - much like in_cksum, which operates on 926 * mbufs. 927 */ 928 u_int16_t 929 gre_in_cksum(u_int16_t *p, u_int len) 930 { 931 u_int32_t sum = 0; 932 int nwords = len >> 1; 933 934 while (nwords-- != 0) 935 sum += *p++; 936 937 if (len & 1) { 938 union { 939 u_short w; 940 u_char c[2]; 941 } u; 942 u.c[0] = *(u_char *)p; 943 u.c[1] = 0; 944 sum += u.w; 945 } 946 947 /* end-around-carry */ 948 sum = (sum >> 16) + (sum & 0xffff); 949 sum += (sum >> 16); 950 return (~sum); 951 } 952 953 static int 954 gremodevent(module_t mod, int type, void *data) 955 { 956 957 switch (type) { 958 case MOD_LOAD: 959 greattach(); 960 break; 961 case MOD_UNLOAD: 962 if_clone_detach(gre_cloner); 963 mtx_destroy(&gre_mtx); 964 break; 965 default: 966 return EOPNOTSUPP; 967 } 968 return 0; 969 } 970 971 static moduledata_t gre_mod = { 972 "if_gre", 973 gremodevent, 974 0 975 }; 976 977 DECLARE_MODULE(if_gre, gre_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 978 MODULE_VERSION(if_gre, 1); 979