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_var.h> 66 #include <net/if_clone.h> 67 #include <net/if_types.h> 68 #include <net/route.h> 69 #include <net/vnet.h> 70 71 #ifdef INET 72 #include <netinet/in.h> 73 #include <netinet/in_systm.h> 74 #include <netinet/in_var.h> 75 #include <netinet/ip.h> 76 #include <netinet/ip_gre.h> 77 #include <netinet/ip_var.h> 78 #include <netinet/ip_encap.h> 79 #else 80 #error "Huh? if_gre without inet?" 81 #endif 82 83 #include <net/bpf.h> 84 85 #include <net/if_gre.h> 86 87 /* 88 * It is not easy to calculate the right value for a GRE MTU. 89 * We leave this task to the admin and use the same default that 90 * other vendors use. 91 */ 92 #define GREMTU 1476 93 94 #define MTAG_COOKIE_GRE 1307983903 95 #define MTAG_GRE_NESTING 1 96 struct mtag_gre_nesting { 97 uint16_t count; 98 uint16_t max; 99 struct ifnet *ifp[]; 100 }; 101 102 /* 103 * gre_mtx protects all global variables in if_gre.c. 104 * XXX: gre_softc data not protected yet. 105 */ 106 struct mtx gre_mtx; 107 static const char grename[] = "gre"; 108 static MALLOC_DEFINE(M_GRE, grename, "Generic Routing Encapsulation"); 109 110 struct gre_softc_head gre_softc_list; 111 112 static int gre_clone_create(struct if_clone *, int, caddr_t); 113 static void gre_clone_destroy(struct ifnet *); 114 static struct if_clone *gre_cloner; 115 116 static int gre_ioctl(struct ifnet *, u_long, caddr_t); 117 static int gre_output(struct ifnet *, struct mbuf *, 118 const struct sockaddr *, struct route *); 119 120 static int gre_compute_route(struct gre_softc *sc); 121 122 static void greattach(void); 123 124 #ifdef INET 125 extern struct domain inetdomain; 126 static const struct protosw in_gre_protosw = { 127 .pr_type = SOCK_RAW, 128 .pr_domain = &inetdomain, 129 .pr_protocol = IPPROTO_GRE, 130 .pr_flags = PR_ATOMIC|PR_ADDR, 131 .pr_input = gre_input, 132 .pr_output = (pr_output_t *)rip_output, 133 .pr_ctlinput = rip_ctlinput, 134 .pr_ctloutput = rip_ctloutput, 135 .pr_usrreqs = &rip_usrreqs 136 }; 137 static const struct protosw in_mobile_protosw = { 138 .pr_type = SOCK_RAW, 139 .pr_domain = &inetdomain, 140 .pr_protocol = IPPROTO_MOBILE, 141 .pr_flags = PR_ATOMIC|PR_ADDR, 142 .pr_input = gre_mobile_input, 143 .pr_output = (pr_output_t *)rip_output, 144 .pr_ctlinput = rip_ctlinput, 145 .pr_ctloutput = rip_ctloutput, 146 .pr_usrreqs = &rip_usrreqs 147 }; 148 #endif 149 150 SYSCTL_DECL(_net_link); 151 static SYSCTL_NODE(_net_link, IFT_TUNNEL, gre, CTLFLAG_RW, 0, 152 "Generic Routing Encapsulation"); 153 #ifndef MAX_GRE_NEST 154 /* 155 * This macro controls the default upper limitation on nesting of gre tunnels. 156 * Since, setting a large value to this macro with a careless configuration 157 * may introduce system crash, we don't allow any nestings by default. 158 * If you need to configure nested gre tunnels, you can define this macro 159 * in your kernel configuration file. However, if you do so, please be 160 * careful to configure the tunnels so that it won't make a loop. 161 */ 162 #define MAX_GRE_NEST 1 163 #endif 164 static int max_gre_nesting = MAX_GRE_NEST; 165 SYSCTL_INT(_net_link_gre, OID_AUTO, max_nesting, CTLFLAG_RW, 166 &max_gre_nesting, 0, "Max nested tunnels"); 167 168 /* ARGSUSED */ 169 static void 170 greattach(void) 171 { 172 173 mtx_init(&gre_mtx, "gre_mtx", NULL, MTX_DEF); 174 LIST_INIT(&gre_softc_list); 175 gre_cloner = if_clone_simple(grename, gre_clone_create, 176 gre_clone_destroy, 0); 177 } 178 179 static int 180 gre_clone_create(ifc, unit, params) 181 struct if_clone *ifc; 182 int unit; 183 caddr_t params; 184 { 185 struct gre_softc *sc; 186 187 sc = malloc(sizeof(struct gre_softc), M_GRE, M_WAITOK | M_ZERO); 188 189 GRE2IFP(sc) = if_alloc(IFT_TUNNEL); 190 if (GRE2IFP(sc) == NULL) { 191 free(sc, M_GRE); 192 return (ENOSPC); 193 } 194 195 GRE2IFP(sc)->if_softc = sc; 196 if_initname(GRE2IFP(sc), grename, unit); 197 198 GRE2IFP(sc)->if_snd.ifq_maxlen = ifqmaxlen; 199 GRE2IFP(sc)->if_addrlen = 0; 200 GRE2IFP(sc)->if_hdrlen = 24; /* IP + GRE */ 201 GRE2IFP(sc)->if_mtu = GREMTU; 202 GRE2IFP(sc)->if_flags = IFF_POINTOPOINT|IFF_MULTICAST; 203 GRE2IFP(sc)->if_output = gre_output; 204 GRE2IFP(sc)->if_ioctl = gre_ioctl; 205 sc->g_dst.s_addr = sc->g_src.s_addr = INADDR_ANY; 206 sc->g_proto = IPPROTO_GRE; 207 GRE2IFP(sc)->if_flags |= IFF_LINK0; 208 sc->encap = NULL; 209 sc->gre_fibnum = curthread->td_proc->p_fibnum; 210 sc->wccp_ver = WCCP_V1; 211 sc->key = 0; 212 if_attach(GRE2IFP(sc)); 213 bpfattach(GRE2IFP(sc), DLT_NULL, sizeof(u_int32_t)); 214 mtx_lock(&gre_mtx); 215 LIST_INSERT_HEAD(&gre_softc_list, sc, sc_list); 216 mtx_unlock(&gre_mtx); 217 return (0); 218 } 219 220 static void 221 gre_clone_destroy(ifp) 222 struct ifnet *ifp; 223 { 224 struct gre_softc *sc = ifp->if_softc; 225 226 mtx_lock(&gre_mtx); 227 LIST_REMOVE(sc, sc_list); 228 mtx_unlock(&gre_mtx); 229 230 #ifdef INET 231 if (sc->encap != NULL) 232 encap_detach(sc->encap); 233 #endif 234 bpfdetach(ifp); 235 if_detach(ifp); 236 if_free(ifp); 237 free(sc, M_GRE); 238 } 239 240 /* 241 * The output routine. Takes a packet and encapsulates it in the protocol 242 * given by sc->g_proto. See also RFC 1701 and RFC 2004 243 */ 244 static int 245 gre_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 246 struct route *ro) 247 { 248 int error = 0; 249 struct gre_softc *sc = ifp->if_softc; 250 struct greip *gh; 251 struct ip *ip; 252 struct m_tag *mtag; 253 struct mtag_gre_nesting *gt; 254 size_t len; 255 u_short gre_ip_id = 0; 256 uint8_t gre_ip_tos = 0; 257 u_int16_t etype = 0; 258 struct mobile_h mob_h; 259 u_int32_t af; 260 int extra = 0, max; 261 262 /* 263 * gre may cause infinite recursion calls when misconfigured. High 264 * nesting level may cause stack exhaustion. We'll prevent this by 265 * detecting loops and by introducing upper limit. 266 */ 267 mtag = m_tag_locate(m, MTAG_COOKIE_GRE, MTAG_GRE_NESTING, NULL); 268 if (mtag != NULL) { 269 struct ifnet **ifp2; 270 271 gt = (struct mtag_gre_nesting *)(mtag + 1); 272 gt->count++; 273 if (gt->count > min(gt->max,max_gre_nesting)) { 274 printf("%s: hit maximum recursion limit %u on %s\n", 275 __func__, gt->count - 1, ifp->if_xname); 276 m_freem(m); 277 error = EIO; /* is there better errno? */ 278 goto end; 279 } 280 281 ifp2 = gt->ifp; 282 for (max = gt->count - 1; max > 0; max--) { 283 if (*ifp2 == ifp) 284 break; 285 ifp2++; 286 } 287 if (*ifp2 == ifp) { 288 printf("%s: detected loop with nexting %u on %s\n", 289 __func__, gt->count-1, ifp->if_xname); 290 m_freem(m); 291 error = EIO; /* is there better errno? */ 292 goto end; 293 } 294 *ifp2 = ifp; 295 296 } else { 297 /* 298 * Given that people should NOT increase max_gre_nesting beyond 299 * their real needs, we allocate once per packet rather than 300 * allocating an mtag once per passing through gre. 301 * 302 * Note: the sysctl does not actually check for saneness, so we 303 * limit the maximum numbers of possible recursions here. 304 */ 305 max = imin(max_gre_nesting, 256); 306 /* If someone sets the sysctl <= 0, we want at least 1. */ 307 max = imax(max, 1); 308 len = sizeof(struct mtag_gre_nesting) + 309 max * sizeof(struct ifnet *); 310 mtag = m_tag_alloc(MTAG_COOKIE_GRE, MTAG_GRE_NESTING, len, 311 M_NOWAIT); 312 if (mtag == NULL) { 313 m_freem(m); 314 error = ENOMEM; 315 goto end; 316 } 317 gt = (struct mtag_gre_nesting *)(mtag + 1); 318 bzero(gt, len); 319 gt->count = 1; 320 gt->max = max; 321 *gt->ifp = ifp; 322 m_tag_prepend(m, mtag); 323 } 324 325 if (!((ifp->if_flags & IFF_UP) && 326 (ifp->if_drv_flags & IFF_DRV_RUNNING)) || 327 sc->g_src.s_addr == INADDR_ANY || sc->g_dst.s_addr == INADDR_ANY) { 328 m_freem(m); 329 error = ENETDOWN; 330 goto end; 331 } 332 333 gh = NULL; 334 ip = NULL; 335 336 /* BPF writes need to be handled specially. */ 337 if (dst->sa_family == AF_UNSPEC) 338 bcopy(dst->sa_data, &af, sizeof(af)); 339 else 340 af = dst->sa_family; 341 342 if (bpf_peers_present(ifp->if_bpf)) 343 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 344 345 if ((ifp->if_flags & IFF_MONITOR) != 0) { 346 m_freem(m); 347 error = ENETDOWN; 348 goto end; 349 } 350 351 m->m_flags &= ~(M_BCAST|M_MCAST); 352 353 if (sc->g_proto == IPPROTO_MOBILE) { 354 if (af == AF_INET) { 355 struct mbuf *m0; 356 int msiz; 357 358 ip = mtod(m, struct ip *); 359 360 /* 361 * RFC2004 specifies that fragmented diagrams shouldn't 362 * be encapsulated. 363 */ 364 if (ip->ip_off & htons(IP_MF | IP_OFFMASK)) { 365 _IF_DROP(&ifp->if_snd); 366 m_freem(m); 367 error = EINVAL; /* is there better errno? */ 368 goto end; 369 } 370 memset(&mob_h, 0, MOB_H_SIZ_L); 371 mob_h.proto = (ip->ip_p) << 8; 372 mob_h.odst = ip->ip_dst.s_addr; 373 ip->ip_dst.s_addr = sc->g_dst.s_addr; 374 375 /* 376 * If the packet comes from our host, we only change 377 * the destination address in the IP header. 378 * Else we also need to save and change the source 379 */ 380 if (in_hosteq(ip->ip_src, sc->g_src)) { 381 msiz = MOB_H_SIZ_S; 382 } else { 383 mob_h.proto |= MOB_H_SBIT; 384 mob_h.osrc = ip->ip_src.s_addr; 385 ip->ip_src.s_addr = sc->g_src.s_addr; 386 msiz = MOB_H_SIZ_L; 387 } 388 mob_h.proto = htons(mob_h.proto); 389 mob_h.hcrc = gre_in_cksum((u_int16_t *)&mob_h, msiz); 390 391 if ((m->m_data - msiz) < m->m_pktdat) { 392 m0 = m_gethdr(M_NOWAIT, MT_DATA); 393 if (m0 == NULL) { 394 _IF_DROP(&ifp->if_snd); 395 m_freem(m); 396 error = ENOBUFS; 397 goto end; 398 } 399 m0->m_next = m; 400 m->m_data += sizeof(struct ip); 401 m->m_len -= sizeof(struct ip); 402 m0->m_pkthdr.len = m->m_pkthdr.len + msiz; 403 m0->m_len = msiz + sizeof(struct ip); 404 m0->m_data += max_linkhdr; 405 memcpy(mtod(m0, caddr_t), (caddr_t)ip, 406 sizeof(struct ip)); 407 m = m0; 408 } else { /* we have some space left in the old one */ 409 m->m_data -= msiz; 410 m->m_len += msiz; 411 m->m_pkthdr.len += msiz; 412 bcopy(ip, mtod(m, caddr_t), 413 sizeof(struct ip)); 414 } 415 ip = mtod(m, struct ip *); 416 memcpy((caddr_t)(ip + 1), &mob_h, (unsigned)msiz); 417 ip->ip_len = htons(ntohs(ip->ip_len) + msiz); 418 } else { /* AF_INET */ 419 _IF_DROP(&ifp->if_snd); 420 m_freem(m); 421 error = EINVAL; 422 goto end; 423 } 424 } else if (sc->g_proto == IPPROTO_GRE) { 425 switch (af) { 426 case AF_INET: 427 ip = mtod(m, struct ip *); 428 gre_ip_tos = ip->ip_tos; 429 gre_ip_id = ip->ip_id; 430 if (sc->wccp_ver == WCCP_V2) { 431 extra = sizeof(uint32_t); 432 etype = WCCP_PROTOCOL_TYPE; 433 } else { 434 etype = ETHERTYPE_IP; 435 } 436 break; 437 #ifdef INET6 438 case AF_INET6: 439 gre_ip_id = ip_newid(); 440 etype = ETHERTYPE_IPV6; 441 break; 442 #endif 443 #ifdef NETATALK 444 case AF_APPLETALK: 445 etype = ETHERTYPE_ATALK; 446 break; 447 #endif 448 default: 449 _IF_DROP(&ifp->if_snd); 450 m_freem(m); 451 error = EAFNOSUPPORT; 452 goto end; 453 } 454 455 /* Reserve space for GRE header + optional GRE key */ 456 int hdrlen = sizeof(struct greip) + extra; 457 if (sc->key) 458 hdrlen += sizeof(uint32_t); 459 M_PREPEND(m, hdrlen, M_NOWAIT); 460 } else { 461 _IF_DROP(&ifp->if_snd); 462 m_freem(m); 463 error = EINVAL; 464 goto end; 465 } 466 467 if (m == NULL) { /* mbuf allocation failed */ 468 _IF_DROP(&ifp->if_snd); 469 error = ENOBUFS; 470 goto end; 471 } 472 473 M_SETFIB(m, sc->gre_fibnum); /* The envelope may use a different FIB */ 474 475 gh = mtod(m, struct greip *); 476 if (sc->g_proto == IPPROTO_GRE) { 477 uint32_t *options = gh->gi_options; 478 479 memset((void *)gh, 0, sizeof(struct greip) + extra); 480 gh->gi_ptype = htons(etype); 481 gh->gi_flags = 0; 482 483 /* Add key option */ 484 if (sc->key) 485 { 486 gh->gi_flags |= htons(GRE_KP); 487 *(options++) = htonl(sc->key); 488 } 489 } 490 491 gh->gi_pr = sc->g_proto; 492 if (sc->g_proto != IPPROTO_MOBILE) { 493 gh->gi_src = sc->g_src; 494 gh->gi_dst = sc->g_dst; 495 ((struct ip*)gh)->ip_v = IPPROTO_IPV4; 496 ((struct ip*)gh)->ip_hl = (sizeof(struct ip)) >> 2; 497 ((struct ip*)gh)->ip_ttl = GRE_TTL; 498 ((struct ip*)gh)->ip_tos = gre_ip_tos; 499 ((struct ip*)gh)->ip_id = gre_ip_id; 500 gh->gi_len = htons(m->m_pkthdr.len); 501 } 502 503 ifp->if_opackets++; 504 ifp->if_obytes += m->m_pkthdr.len; 505 /* 506 * Send it off and with IP_FORWARD flag to prevent it from 507 * overwriting the ip_id again. ip_id is already set to the 508 * ip_id of the encapsulated packet. 509 */ 510 error = ip_output(m, NULL, &sc->route, IP_FORWARDING, 511 (struct ip_moptions *)NULL, (struct inpcb *)NULL); 512 end: 513 if (error) 514 ifp->if_oerrors++; 515 return (error); 516 } 517 518 static int 519 gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 520 { 521 struct ifreq *ifr = (struct ifreq *)data; 522 struct if_laddrreq *lifr = (struct if_laddrreq *)data; 523 struct in_aliasreq *aifr = (struct in_aliasreq *)data; 524 struct gre_softc *sc = ifp->if_softc; 525 struct sockaddr_in si; 526 struct sockaddr *sa = NULL; 527 int error, adj; 528 struct sockaddr_in sp, sm, dp, dm; 529 uint32_t key; 530 531 error = 0; 532 adj = 0; 533 534 switch (cmd) { 535 case SIOCSIFADDR: 536 ifp->if_flags |= IFF_UP; 537 break; 538 case SIOCSIFFLAGS: 539 /* 540 * XXXRW: Isn't this priv_check() redundant to the ifnet 541 * layer check? 542 */ 543 if ((error = priv_check(curthread, PRIV_NET_SETIFFLAGS)) != 0) 544 break; 545 if ((ifr->ifr_flags & IFF_LINK0) != 0) 546 sc->g_proto = IPPROTO_GRE; 547 else 548 sc->g_proto = IPPROTO_MOBILE; 549 if ((ifr->ifr_flags & IFF_LINK2) != 0) 550 sc->wccp_ver = WCCP_V2; 551 else 552 sc->wccp_ver = WCCP_V1; 553 goto recompute; 554 case SIOCSIFMTU: 555 /* 556 * XXXRW: Isn't this priv_check() redundant to the ifnet 557 * layer check? 558 */ 559 if ((error = priv_check(curthread, PRIV_NET_SETIFMTU)) != 0) 560 break; 561 if (ifr->ifr_mtu < 576) { 562 error = EINVAL; 563 break; 564 } 565 ifp->if_mtu = ifr->ifr_mtu; 566 break; 567 case SIOCGIFMTU: 568 ifr->ifr_mtu = GRE2IFP(sc)->if_mtu; 569 break; 570 case SIOCADDMULTI: 571 /* 572 * XXXRW: Isn't this priv_checkr() redundant to the ifnet 573 * layer check? 574 */ 575 if ((error = priv_check(curthread, PRIV_NET_ADDMULTI)) != 0) 576 break; 577 if (ifr == 0) { 578 error = EAFNOSUPPORT; 579 break; 580 } 581 switch (ifr->ifr_addr.sa_family) { 582 #ifdef INET 583 case AF_INET: 584 break; 585 #endif 586 #ifdef INET6 587 case AF_INET6: 588 break; 589 #endif 590 default: 591 error = EAFNOSUPPORT; 592 break; 593 } 594 break; 595 case SIOCDELMULTI: 596 /* 597 * XXXRW: Isn't this priv_check() redundant to the ifnet 598 * layer check? 599 */ 600 if ((error = priv_check(curthread, PRIV_NET_DELIFGROUP)) != 0) 601 break; 602 if (ifr == 0) { 603 error = EAFNOSUPPORT; 604 break; 605 } 606 switch (ifr->ifr_addr.sa_family) { 607 #ifdef INET 608 case AF_INET: 609 break; 610 #endif 611 #ifdef INET6 612 case AF_INET6: 613 break; 614 #endif 615 default: 616 error = EAFNOSUPPORT; 617 break; 618 } 619 break; 620 case GRESPROTO: 621 /* 622 * XXXRW: Isn't this priv_check() redundant to the ifnet 623 * layer check? 624 */ 625 if ((error = priv_check(curthread, PRIV_NET_GRE)) != 0) 626 break; 627 sc->g_proto = ifr->ifr_flags; 628 switch (sc->g_proto) { 629 case IPPROTO_GRE: 630 ifp->if_flags |= IFF_LINK0; 631 break; 632 case IPPROTO_MOBILE: 633 ifp->if_flags &= ~IFF_LINK0; 634 break; 635 default: 636 error = EPROTONOSUPPORT; 637 break; 638 } 639 goto recompute; 640 case GREGPROTO: 641 ifr->ifr_flags = sc->g_proto; 642 break; 643 case GRESADDRS: 644 case GRESADDRD: 645 error = priv_check(curthread, PRIV_NET_GRE); 646 if (error) 647 return (error); 648 /* 649 * set tunnel endpoints, compute a less specific route 650 * to the remote end and mark if as up 651 */ 652 sa = &ifr->ifr_addr; 653 if (cmd == GRESADDRS) 654 sc->g_src = (satosin(sa))->sin_addr; 655 if (cmd == GRESADDRD) 656 sc->g_dst = (satosin(sa))->sin_addr; 657 recompute: 658 #ifdef INET 659 if (sc->encap != NULL) { 660 encap_detach(sc->encap); 661 sc->encap = NULL; 662 } 663 #endif 664 if ((sc->g_src.s_addr != INADDR_ANY) && 665 (sc->g_dst.s_addr != INADDR_ANY)) { 666 bzero(&sp, sizeof(sp)); 667 bzero(&sm, sizeof(sm)); 668 bzero(&dp, sizeof(dp)); 669 bzero(&dm, sizeof(dm)); 670 sp.sin_len = sm.sin_len = dp.sin_len = dm.sin_len = 671 sizeof(struct sockaddr_in); 672 sp.sin_family = sm.sin_family = dp.sin_family = 673 dm.sin_family = AF_INET; 674 sp.sin_addr = sc->g_src; 675 dp.sin_addr = sc->g_dst; 676 sm.sin_addr.s_addr = dm.sin_addr.s_addr = 677 INADDR_BROADCAST; 678 #ifdef INET 679 sc->encap = encap_attach(AF_INET, sc->g_proto, 680 sintosa(&sp), sintosa(&sm), sintosa(&dp), 681 sintosa(&dm), (sc->g_proto == IPPROTO_GRE) ? 682 &in_gre_protosw : &in_mobile_protosw, sc); 683 if (sc->encap == NULL) 684 printf("%s: unable to attach encap\n", 685 if_name(GRE2IFP(sc))); 686 #endif 687 if (sc->route.ro_rt != 0) /* free old route */ 688 RTFREE(sc->route.ro_rt); 689 if (gre_compute_route(sc) == 0) 690 ifp->if_drv_flags |= IFF_DRV_RUNNING; 691 else 692 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 693 } 694 break; 695 case GREGADDRS: 696 memset(&si, 0, sizeof(si)); 697 si.sin_family = AF_INET; 698 si.sin_len = sizeof(struct sockaddr_in); 699 si.sin_addr.s_addr = sc->g_src.s_addr; 700 sa = sintosa(&si); 701 error = prison_if(curthread->td_ucred, sa); 702 if (error != 0) 703 break; 704 ifr->ifr_addr = *sa; 705 break; 706 case GREGADDRD: 707 memset(&si, 0, sizeof(si)); 708 si.sin_family = AF_INET; 709 si.sin_len = sizeof(struct sockaddr_in); 710 si.sin_addr.s_addr = sc->g_dst.s_addr; 711 sa = sintosa(&si); 712 error = prison_if(curthread->td_ucred, sa); 713 if (error != 0) 714 break; 715 ifr->ifr_addr = *sa; 716 break; 717 case SIOCSIFPHYADDR: 718 /* 719 * XXXRW: Isn't this priv_check() redundant to the ifnet 720 * layer check? 721 */ 722 if ((error = priv_check(curthread, PRIV_NET_SETIFPHYS)) != 0) 723 break; 724 if (aifr->ifra_addr.sin_family != AF_INET || 725 aifr->ifra_dstaddr.sin_family != AF_INET) { 726 error = EAFNOSUPPORT; 727 break; 728 } 729 if (aifr->ifra_addr.sin_len != sizeof(si) || 730 aifr->ifra_dstaddr.sin_len != sizeof(si)) { 731 error = EINVAL; 732 break; 733 } 734 sc->g_src = aifr->ifra_addr.sin_addr; 735 sc->g_dst = aifr->ifra_dstaddr.sin_addr; 736 goto recompute; 737 case SIOCSLIFPHYADDR: 738 /* 739 * XXXRW: Isn't this priv_check() redundant to the ifnet 740 * layer check? 741 */ 742 if ((error = priv_check(curthread, PRIV_NET_SETIFPHYS)) != 0) 743 break; 744 if (lifr->addr.ss_family != AF_INET || 745 lifr->dstaddr.ss_family != AF_INET) { 746 error = EAFNOSUPPORT; 747 break; 748 } 749 if (lifr->addr.ss_len != sizeof(si) || 750 lifr->dstaddr.ss_len != sizeof(si)) { 751 error = EINVAL; 752 break; 753 } 754 sc->g_src = (satosin(&lifr->addr))->sin_addr; 755 sc->g_dst = 756 (satosin(&lifr->dstaddr))->sin_addr; 757 goto recompute; 758 case SIOCDIFPHYADDR: 759 /* 760 * XXXRW: Isn't this priv_check() redundant to the ifnet 761 * layer check? 762 */ 763 if ((error = priv_check(curthread, PRIV_NET_SETIFPHYS)) != 0) 764 break; 765 sc->g_src.s_addr = INADDR_ANY; 766 sc->g_dst.s_addr = INADDR_ANY; 767 goto recompute; 768 case SIOCGLIFPHYADDR: 769 if (sc->g_src.s_addr == INADDR_ANY || 770 sc->g_dst.s_addr == INADDR_ANY) { 771 error = EADDRNOTAVAIL; 772 break; 773 } 774 memset(&si, 0, sizeof(si)); 775 si.sin_family = AF_INET; 776 si.sin_len = sizeof(struct sockaddr_in); 777 si.sin_addr.s_addr = sc->g_src.s_addr; 778 error = prison_if(curthread->td_ucred, (struct sockaddr *)&si); 779 if (error != 0) 780 break; 781 memcpy(&lifr->addr, &si, sizeof(si)); 782 si.sin_addr.s_addr = sc->g_dst.s_addr; 783 error = prison_if(curthread->td_ucred, (struct sockaddr *)&si); 784 if (error != 0) 785 break; 786 memcpy(&lifr->dstaddr, &si, sizeof(si)); 787 break; 788 case SIOCGIFPSRCADDR: 789 #ifdef INET6 790 case SIOCGIFPSRCADDR_IN6: 791 #endif 792 if (sc->g_src.s_addr == INADDR_ANY) { 793 error = EADDRNOTAVAIL; 794 break; 795 } 796 memset(&si, 0, sizeof(si)); 797 si.sin_family = AF_INET; 798 si.sin_len = sizeof(struct sockaddr_in); 799 si.sin_addr.s_addr = sc->g_src.s_addr; 800 error = prison_if(curthread->td_ucred, (struct sockaddr *)&si); 801 if (error != 0) 802 break; 803 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr)); 804 break; 805 case SIOCGIFPDSTADDR: 806 #ifdef INET6 807 case SIOCGIFPDSTADDR_IN6: 808 #endif 809 if (sc->g_dst.s_addr == INADDR_ANY) { 810 error = EADDRNOTAVAIL; 811 break; 812 } 813 memset(&si, 0, sizeof(si)); 814 si.sin_family = AF_INET; 815 si.sin_len = sizeof(struct sockaddr_in); 816 si.sin_addr.s_addr = sc->g_dst.s_addr; 817 error = prison_if(curthread->td_ucred, (struct sockaddr *)&si); 818 if (error != 0) 819 break; 820 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr)); 821 break; 822 case GRESKEY: 823 error = priv_check(curthread, PRIV_NET_GRE); 824 if (error) 825 break; 826 error = copyin(ifr->ifr_data, &key, sizeof(key)); 827 if (error) 828 break; 829 /* adjust MTU for option header */ 830 if (key == 0 && sc->key != 0) /* clear */ 831 adj += sizeof(key); 832 else if (key != 0 && sc->key == 0) /* set */ 833 adj -= sizeof(key); 834 835 if (ifp->if_mtu + adj < 576) { 836 error = EINVAL; 837 break; 838 } 839 ifp->if_mtu += adj; 840 sc->key = key; 841 break; 842 case GREGKEY: 843 error = copyout(&sc->key, ifr->ifr_data, sizeof(sc->key)); 844 break; 845 846 default: 847 error = EINVAL; 848 break; 849 } 850 851 return (error); 852 } 853 854 /* 855 * computes a route to our destination that is not the one 856 * which would be taken by ip_output(), as this one will loop back to 857 * us. If the interface is p2p as a--->b, then a routing entry exists 858 * If we now send a packet to b (e.g. ping b), this will come down here 859 * gets src=a, dst=b tacked on and would from ip_output() sent back to 860 * if_gre. 861 * Goal here is to compute a route to b that is less specific than 862 * a-->b. We know that this one exists as in normal operation we have 863 * at least a default route which matches. 864 */ 865 static int 866 gre_compute_route(struct gre_softc *sc) 867 { 868 struct route *ro; 869 870 ro = &sc->route; 871 872 memset(ro, 0, sizeof(struct route)); 873 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst; 874 ro->ro_dst.sa_family = AF_INET; 875 ro->ro_dst.sa_len = sizeof(ro->ro_dst); 876 877 /* 878 * toggle last bit, so our interface is not found, but a less 879 * specific route. I'd rather like to specify a shorter mask, 880 * but this is not possible. Should work though. XXX 881 * XXX MRT Use a different FIB for the tunnel to solve this problem. 882 */ 883 if ((GRE2IFP(sc)->if_flags & IFF_LINK1) == 0) { 884 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr.s_addr ^= 885 htonl(0x01); 886 } 887 888 #ifdef DIAGNOSTIC 889 printf("%s: searching for a route to %s", if_name(GRE2IFP(sc)), 890 inet_ntoa(((struct sockaddr_in *)&ro->ro_dst)->sin_addr)); 891 #endif 892 893 rtalloc_fib(ro, sc->gre_fibnum); 894 895 /* 896 * check if this returned a route at all and this route is no 897 * recursion to ourself 898 */ 899 if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp->if_softc == sc) { 900 #ifdef DIAGNOSTIC 901 if (ro->ro_rt == NULL) 902 printf(" - no route found!\n"); 903 else 904 printf(" - route loops back to ourself!\n"); 905 #endif 906 return EADDRNOTAVAIL; 907 } 908 909 /* 910 * now change it back - else ip_output will just drop 911 * the route and search one to this interface ... 912 */ 913 if ((GRE2IFP(sc)->if_flags & IFF_LINK1) == 0) 914 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst; 915 916 #ifdef DIAGNOSTIC 917 printf(", choosing %s with gateway %s", if_name(ro->ro_rt->rt_ifp), 918 inet_ntoa(((struct sockaddr_in *)(ro->ro_rt->rt_gateway))->sin_addr)); 919 printf("\n"); 920 #endif 921 922 return 0; 923 } 924 925 /* 926 * do a checksum of a buffer - much like in_cksum, which operates on 927 * mbufs. 928 */ 929 u_int16_t 930 gre_in_cksum(u_int16_t *p, u_int len) 931 { 932 u_int32_t sum = 0; 933 int nwords = len >> 1; 934 935 while (nwords-- != 0) 936 sum += *p++; 937 938 if (len & 1) { 939 union { 940 u_short w; 941 u_char c[2]; 942 } u; 943 u.c[0] = *(u_char *)p; 944 u.c[1] = 0; 945 sum += u.w; 946 } 947 948 /* end-around-carry */ 949 sum = (sum >> 16) + (sum & 0xffff); 950 sum += (sum >> 16); 951 return (~sum); 952 } 953 954 static int 955 gremodevent(module_t mod, int type, void *data) 956 { 957 958 switch (type) { 959 case MOD_LOAD: 960 greattach(); 961 break; 962 case MOD_UNLOAD: 963 if_clone_detach(gre_cloner); 964 mtx_destroy(&gre_mtx); 965 break; 966 default: 967 return EOPNOTSUPP; 968 } 969 return 0; 970 } 971 972 static moduledata_t gre_mod = { 973 "if_gre", 974 gremodevent, 975 0 976 }; 977 978 DECLARE_MODULE(if_gre, gre_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 979 MODULE_VERSION(if_gre, 1); 980