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 * 3. All advertising materials mentioning features or use of this software 22 * must display the following acknowledgement: 23 * This product includes software developed by the NetBSD 24 * Foundation, Inc. and its contributors. 25 * 4. Neither the name of The NetBSD Foundation nor the names of its 26 * contributors may be used to endorse or promote products derived 27 * from this software without specific prior written permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 30 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 31 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 32 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 33 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 34 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 35 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 36 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 37 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 38 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 39 * POSSIBILITY OF SUCH DAMAGE. 40 */ 41 42 /* 43 * Encapsulate L3 protocols into IP 44 * See RFC 2784 (successor of RFC 1701 and 1702) for more details. 45 * If_gre is compatible with Cisco GRE tunnels, so you can 46 * have a NetBSD box as the other end of a tunnel interface of a Cisco 47 * router. See gre(4) for more details. 48 * Also supported: IP in IP encaps (proto 55) as of RFC 2004 49 */ 50 51 #include "opt_atalk.h" 52 #include "opt_inet.h" 53 #include "opt_inet6.h" 54 55 #include <sys/param.h> 56 #include <sys/kernel.h> 57 #include <sys/malloc.h> 58 #include <sys/module.h> 59 #include <sys/mbuf.h> 60 #include <sys/priv.h> 61 #include <sys/proc.h> 62 #include <sys/protosw.h> 63 #include <sys/socket.h> 64 #include <sys/sockio.h> 65 #include <sys/sysctl.h> 66 #include <sys/systm.h> 67 68 #include <net/ethernet.h> 69 #include <net/if.h> 70 #include <net/if_clone.h> 71 #include <net/if_types.h> 72 #include <net/route.h> 73 74 #ifdef INET 75 #include <netinet/in.h> 76 #include <netinet/in_systm.h> 77 #include <netinet/in_var.h> 78 #include <netinet/ip.h> 79 #include <netinet/ip_gre.h> 80 #include <netinet/ip_var.h> 81 #include <netinet/ip_encap.h> 82 #else 83 #error "Huh? if_gre without inet?" 84 #endif 85 86 #include <net/bpf.h> 87 88 #include <net/if_gre.h> 89 90 /* 91 * It is not easy to calculate the right value for a GRE MTU. 92 * We leave this task to the admin and use the same default that 93 * other vendors use. 94 */ 95 #define GREMTU 1476 96 97 #define GRENAME "gre" 98 99 /* 100 * gre_mtx protects all global variables in if_gre.c. 101 * XXX: gre_softc data not protected yet. 102 */ 103 struct mtx gre_mtx; 104 static MALLOC_DEFINE(M_GRE, GRENAME, "Generic Routing Encapsulation"); 105 106 struct gre_softc_head gre_softc_list; 107 108 static int gre_clone_create(struct if_clone *, int, caddr_t); 109 static void gre_clone_destroy(struct ifnet *); 110 static int gre_ioctl(struct ifnet *, u_long, caddr_t); 111 static int gre_output(struct ifnet *, struct mbuf *, struct sockaddr *, 112 struct rtentry *rt); 113 114 IFC_SIMPLE_DECLARE(gre, 0); 115 116 static int gre_compute_route(struct gre_softc *sc); 117 118 static void greattach(void); 119 120 #ifdef INET 121 extern struct domain inetdomain; 122 static const struct protosw in_gre_protosw = { 123 .pr_type = SOCK_RAW, 124 .pr_domain = &inetdomain, 125 .pr_protocol = IPPROTO_GRE, 126 .pr_flags = PR_ATOMIC|PR_ADDR, 127 .pr_input = gre_input, 128 .pr_output = (pr_output_t *)rip_output, 129 .pr_ctlinput = rip_ctlinput, 130 .pr_ctloutput = rip_ctloutput, 131 .pr_usrreqs = &rip_usrreqs 132 }; 133 static const struct protosw in_mobile_protosw = { 134 .pr_type = SOCK_RAW, 135 .pr_domain = &inetdomain, 136 .pr_protocol = IPPROTO_MOBILE, 137 .pr_flags = PR_ATOMIC|PR_ADDR, 138 .pr_input = gre_mobile_input, 139 .pr_output = (pr_output_t *)rip_output, 140 .pr_ctlinput = rip_ctlinput, 141 .pr_ctloutput = rip_ctloutput, 142 .pr_usrreqs = &rip_usrreqs 143 }; 144 #endif 145 146 SYSCTL_DECL(_net_link); 147 SYSCTL_NODE(_net_link, IFT_TUNNEL, gre, CTLFLAG_RW, 0, 148 "Generic Routing Encapsulation"); 149 #ifndef MAX_GRE_NEST 150 /* 151 * This macro controls the default upper limitation on nesting of gre tunnels. 152 * Since, setting a large value to this macro with a careless configuration 153 * may introduce system crash, we don't allow any nestings by default. 154 * If you need to configure nested gre tunnels, you can define this macro 155 * in your kernel configuration file. However, if you do so, please be 156 * careful to configure the tunnels so that it won't make a loop. 157 */ 158 #define MAX_GRE_NEST 1 159 #endif 160 static int max_gre_nesting = MAX_GRE_NEST; 161 SYSCTL_INT(_net_link_gre, OID_AUTO, max_nesting, CTLFLAG_RW, 162 &max_gre_nesting, 0, "Max nested tunnels"); 163 164 /* ARGSUSED */ 165 static void 166 greattach(void) 167 { 168 169 mtx_init(&gre_mtx, "gre_mtx", NULL, MTX_DEF); 170 LIST_INIT(&gre_softc_list); 171 if_clone_attach(&gre_cloner); 172 } 173 174 static int 175 gre_clone_create(ifc, unit, params) 176 struct if_clone *ifc; 177 int unit; 178 caddr_t params; 179 { 180 struct gre_softc *sc; 181 182 sc = malloc(sizeof(struct gre_softc), M_GRE, M_WAITOK | M_ZERO); 183 184 GRE2IFP(sc) = if_alloc(IFT_TUNNEL); 185 if (GRE2IFP(sc) == NULL) { 186 free(sc, M_GRE); 187 return (ENOSPC); 188 } 189 190 GRE2IFP(sc)->if_softc = sc; 191 if_initname(GRE2IFP(sc), ifc->ifc_name, unit); 192 193 GRE2IFP(sc)->if_snd.ifq_maxlen = IFQ_MAXLEN; 194 GRE2IFP(sc)->if_addrlen = 0; 195 GRE2IFP(sc)->if_hdrlen = 24; /* IP + GRE */ 196 GRE2IFP(sc)->if_mtu = GREMTU; 197 GRE2IFP(sc)->if_flags = IFF_POINTOPOINT|IFF_MULTICAST; 198 GRE2IFP(sc)->if_output = gre_output; 199 GRE2IFP(sc)->if_ioctl = gre_ioctl; 200 sc->g_dst.s_addr = sc->g_src.s_addr = INADDR_ANY; 201 sc->g_proto = IPPROTO_GRE; 202 GRE2IFP(sc)->if_flags |= IFF_LINK0; 203 sc->encap = NULL; 204 sc->called = 0; 205 sc->gre_fibnum = curthread->td_proc->p_fibnum; 206 sc->wccp_ver = WCCP_V1; 207 sc->key = 0; 208 if_attach(GRE2IFP(sc)); 209 bpfattach(GRE2IFP(sc), DLT_NULL, sizeof(u_int32_t)); 210 mtx_lock(&gre_mtx); 211 LIST_INSERT_HEAD(&gre_softc_list, sc, sc_list); 212 mtx_unlock(&gre_mtx); 213 return (0); 214 } 215 216 static void 217 gre_clone_destroy(ifp) 218 struct ifnet *ifp; 219 { 220 struct gre_softc *sc = ifp->if_softc; 221 222 mtx_lock(&gre_mtx); 223 LIST_REMOVE(sc, sc_list); 224 mtx_unlock(&gre_mtx); 225 226 #ifdef INET 227 if (sc->encap != NULL) 228 encap_detach(sc->encap); 229 #endif 230 bpfdetach(ifp); 231 if_detach(ifp); 232 if_free(ifp); 233 free(sc, M_GRE); 234 } 235 236 /* 237 * The output routine. Takes a packet and encapsulates it in the protocol 238 * given by sc->g_proto. See also RFC 1701 and RFC 2004 239 */ 240 static int 241 gre_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 242 struct rtentry *rt) 243 { 244 #ifdef INET6 245 INIT_VNET_INET(ifp->if_vnet); 246 #endif 247 int error = 0; 248 struct gre_softc *sc = ifp->if_softc; 249 struct greip *gh; 250 struct ip *ip; 251 u_short gre_ip_id = 0; 252 uint8_t gre_ip_tos = 0; 253 u_int16_t etype = 0; 254 struct mobile_h mob_h; 255 u_int32_t af; 256 int extra = 0; 257 258 /* 259 * gre may cause infinite recursion calls when misconfigured. 260 * We'll prevent this by introducing upper limit. 261 */ 262 if (++(sc->called) > max_gre_nesting) { 263 printf("%s: gre_output: recursively called too many " 264 "times(%d)\n", if_name(GRE2IFP(sc)), sc->called); 265 m_freem(m); 266 error = EIO; /* is there better errno? */ 267 goto end; 268 } 269 270 if (!((ifp->if_flags & IFF_UP) && 271 (ifp->if_drv_flags & IFF_DRV_RUNNING)) || 272 sc->g_src.s_addr == INADDR_ANY || sc->g_dst.s_addr == INADDR_ANY) { 273 m_freem(m); 274 error = ENETDOWN; 275 goto end; 276 } 277 278 gh = NULL; 279 ip = NULL; 280 281 /* BPF writes need to be handled specially. */ 282 if (dst->sa_family == AF_UNSPEC) { 283 bcopy(dst->sa_data, &af, sizeof(af)); 284 dst->sa_family = af; 285 } 286 287 if (bpf_peers_present(ifp->if_bpf)) { 288 af = dst->sa_family; 289 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 290 } 291 292 m->m_flags &= ~(M_BCAST|M_MCAST); 293 294 if (sc->g_proto == IPPROTO_MOBILE) { 295 if (dst->sa_family == AF_INET) { 296 struct mbuf *m0; 297 int msiz; 298 299 ip = mtod(m, struct ip *); 300 301 /* 302 * RFC2004 specifies that fragmented diagrams shouldn't 303 * be encapsulated. 304 */ 305 if (ip->ip_off & (IP_MF | IP_OFFMASK)) { 306 _IF_DROP(&ifp->if_snd); 307 m_freem(m); 308 error = EINVAL; /* is there better errno? */ 309 goto end; 310 } 311 memset(&mob_h, 0, MOB_H_SIZ_L); 312 mob_h.proto = (ip->ip_p) << 8; 313 mob_h.odst = ip->ip_dst.s_addr; 314 ip->ip_dst.s_addr = sc->g_dst.s_addr; 315 316 /* 317 * If the packet comes from our host, we only change 318 * the destination address in the IP header. 319 * Else we also need to save and change the source 320 */ 321 if (in_hosteq(ip->ip_src, sc->g_src)) { 322 msiz = MOB_H_SIZ_S; 323 } else { 324 mob_h.proto |= MOB_H_SBIT; 325 mob_h.osrc = ip->ip_src.s_addr; 326 ip->ip_src.s_addr = sc->g_src.s_addr; 327 msiz = MOB_H_SIZ_L; 328 } 329 mob_h.proto = htons(mob_h.proto); 330 mob_h.hcrc = gre_in_cksum((u_int16_t *)&mob_h, msiz); 331 332 if ((m->m_data - msiz) < m->m_pktdat) { 333 /* need new mbuf */ 334 MGETHDR(m0, M_DONTWAIT, MT_DATA); 335 if (m0 == NULL) { 336 _IF_DROP(&ifp->if_snd); 337 m_freem(m); 338 error = ENOBUFS; 339 goto end; 340 } 341 m0->m_next = m; 342 m->m_data += sizeof(struct ip); 343 m->m_len -= sizeof(struct ip); 344 m0->m_pkthdr.len = m->m_pkthdr.len + msiz; 345 m0->m_len = msiz + sizeof(struct ip); 346 m0->m_data += max_linkhdr; 347 memcpy(mtod(m0, caddr_t), (caddr_t)ip, 348 sizeof(struct ip)); 349 m = m0; 350 } else { /* we have some space left in the old one */ 351 m->m_data -= msiz; 352 m->m_len += msiz; 353 m->m_pkthdr.len += msiz; 354 bcopy(ip, mtod(m, caddr_t), 355 sizeof(struct ip)); 356 } 357 ip = mtod(m, struct ip *); 358 memcpy((caddr_t)(ip + 1), &mob_h, (unsigned)msiz); 359 ip->ip_len = ntohs(ip->ip_len) + msiz; 360 } else { /* AF_INET */ 361 _IF_DROP(&ifp->if_snd); 362 m_freem(m); 363 error = EINVAL; 364 goto end; 365 } 366 } else if (sc->g_proto == IPPROTO_GRE) { 367 switch (dst->sa_family) { 368 case AF_INET: 369 ip = mtod(m, struct ip *); 370 gre_ip_tos = ip->ip_tos; 371 gre_ip_id = ip->ip_id; 372 if (sc->wccp_ver == WCCP_V2) { 373 extra = sizeof(uint32_t); 374 etype = WCCP_PROTOCOL_TYPE; 375 } else { 376 etype = ETHERTYPE_IP; 377 } 378 break; 379 #ifdef INET6 380 case AF_INET6: 381 gre_ip_id = ip_newid(); 382 etype = ETHERTYPE_IPV6; 383 break; 384 #endif 385 #ifdef NETATALK 386 case AF_APPLETALK: 387 etype = ETHERTYPE_ATALK; 388 break; 389 #endif 390 default: 391 _IF_DROP(&ifp->if_snd); 392 m_freem(m); 393 error = EAFNOSUPPORT; 394 goto end; 395 } 396 397 /* Reserve space for GRE header + optional GRE key */ 398 int hdrlen = sizeof(struct greip) + extra; 399 if (sc->key) 400 hdrlen += sizeof(uint32_t); 401 M_PREPEND(m, hdrlen, M_DONTWAIT); 402 } else { 403 _IF_DROP(&ifp->if_snd); 404 m_freem(m); 405 error = EINVAL; 406 goto end; 407 } 408 409 if (m == NULL) { /* mbuf allocation failed */ 410 _IF_DROP(&ifp->if_snd); 411 error = ENOBUFS; 412 goto end; 413 } 414 415 M_SETFIB(m, sc->gre_fibnum); /* The envelope may use a different FIB */ 416 417 gh = mtod(m, struct greip *); 418 if (sc->g_proto == IPPROTO_GRE) { 419 uint32_t *options = gh->gi_options; 420 421 memset((void *)gh, 0, sizeof(struct greip) + extra); 422 gh->gi_ptype = htons(etype); 423 gh->gi_flags = 0; 424 425 /* Add key option */ 426 if (sc->key) 427 { 428 gh->gi_flags |= htons(GRE_KP); 429 *(options++) = htonl(sc->key); 430 } 431 } 432 433 gh->gi_pr = sc->g_proto; 434 if (sc->g_proto != IPPROTO_MOBILE) { 435 gh->gi_src = sc->g_src; 436 gh->gi_dst = sc->g_dst; 437 ((struct ip*)gh)->ip_v = IPPROTO_IPV4; 438 ((struct ip*)gh)->ip_hl = (sizeof(struct ip)) >> 2; 439 ((struct ip*)gh)->ip_ttl = GRE_TTL; 440 ((struct ip*)gh)->ip_tos = gre_ip_tos; 441 ((struct ip*)gh)->ip_id = gre_ip_id; 442 gh->gi_len = m->m_pkthdr.len; 443 } 444 445 ifp->if_opackets++; 446 ifp->if_obytes += m->m_pkthdr.len; 447 /* 448 * Send it off and with IP_FORWARD flag to prevent it from 449 * overwriting the ip_id again. ip_id is already set to the 450 * ip_id of the encapsulated packet. 451 */ 452 error = ip_output(m, NULL, &sc->route, IP_FORWARDING, 453 (struct ip_moptions *)NULL, (struct inpcb *)NULL); 454 end: 455 sc->called = 0; 456 if (error) 457 ifp->if_oerrors++; 458 return (error); 459 } 460 461 static int 462 gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 463 { 464 struct ifreq *ifr = (struct ifreq *)data; 465 struct if_laddrreq *lifr = (struct if_laddrreq *)data; 466 struct in_aliasreq *aifr = (struct in_aliasreq *)data; 467 struct gre_softc *sc = ifp->if_softc; 468 int s; 469 struct sockaddr_in si; 470 struct sockaddr *sa = NULL; 471 int error, adj; 472 struct sockaddr_in sp, sm, dp, dm; 473 uint32_t key; 474 475 error = 0; 476 adj = 0; 477 478 s = splnet(); 479 switch (cmd) { 480 case SIOCSIFADDR: 481 ifp->if_flags |= IFF_UP; 482 break; 483 case SIOCSIFDSTADDR: 484 break; 485 case SIOCSIFFLAGS: 486 /* 487 * XXXRW: Isn't this priv_check() redundant to the ifnet 488 * layer check? 489 */ 490 if ((error = priv_check(curthread, PRIV_NET_SETIFFLAGS)) != 0) 491 break; 492 if ((ifr->ifr_flags & IFF_LINK0) != 0) 493 sc->g_proto = IPPROTO_GRE; 494 else 495 sc->g_proto = IPPROTO_MOBILE; 496 if ((ifr->ifr_flags & IFF_LINK2) != 0) 497 sc->wccp_ver = WCCP_V2; 498 else 499 sc->wccp_ver = WCCP_V1; 500 goto recompute; 501 case SIOCSIFMTU: 502 /* 503 * XXXRW: Isn't this priv_check() redundant to the ifnet 504 * layer check? 505 */ 506 if ((error = priv_check(curthread, PRIV_NET_SETIFMTU)) != 0) 507 break; 508 if (ifr->ifr_mtu < 576) { 509 error = EINVAL; 510 break; 511 } 512 ifp->if_mtu = ifr->ifr_mtu; 513 break; 514 case SIOCGIFMTU: 515 ifr->ifr_mtu = GRE2IFP(sc)->if_mtu; 516 break; 517 case SIOCADDMULTI: 518 /* 519 * XXXRW: Isn't this priv_checkr() redundant to the ifnet 520 * layer check? 521 */ 522 if ((error = priv_check(curthread, PRIV_NET_ADDMULTI)) != 0) 523 break; 524 if (ifr == 0) { 525 error = EAFNOSUPPORT; 526 break; 527 } 528 switch (ifr->ifr_addr.sa_family) { 529 #ifdef INET 530 case AF_INET: 531 break; 532 #endif 533 #ifdef INET6 534 case AF_INET6: 535 break; 536 #endif 537 default: 538 error = EAFNOSUPPORT; 539 break; 540 } 541 break; 542 case SIOCDELMULTI: 543 /* 544 * XXXRW: Isn't this priv_check() redundant to the ifnet 545 * layer check? 546 */ 547 if ((error = priv_check(curthread, PRIV_NET_DELIFGROUP)) != 0) 548 break; 549 if (ifr == 0) { 550 error = EAFNOSUPPORT; 551 break; 552 } 553 switch (ifr->ifr_addr.sa_family) { 554 #ifdef INET 555 case AF_INET: 556 break; 557 #endif 558 #ifdef INET6 559 case AF_INET6: 560 break; 561 #endif 562 default: 563 error = EAFNOSUPPORT; 564 break; 565 } 566 break; 567 case GRESPROTO: 568 /* 569 * XXXRW: Isn't this priv_check() redundant to the ifnet 570 * layer check? 571 */ 572 if ((error = priv_check(curthread, PRIV_NET_GRE)) != 0) 573 break; 574 sc->g_proto = ifr->ifr_flags; 575 switch (sc->g_proto) { 576 case IPPROTO_GRE: 577 ifp->if_flags |= IFF_LINK0; 578 break; 579 case IPPROTO_MOBILE: 580 ifp->if_flags &= ~IFF_LINK0; 581 break; 582 default: 583 error = EPROTONOSUPPORT; 584 break; 585 } 586 goto recompute; 587 case GREGPROTO: 588 ifr->ifr_flags = sc->g_proto; 589 break; 590 case GRESADDRS: 591 case GRESADDRD: 592 error = priv_check(curthread, PRIV_NET_GRE); 593 if (error) 594 return (error); 595 /* 596 * set tunnel endpoints, compute a less specific route 597 * to the remote end and mark if as up 598 */ 599 sa = &ifr->ifr_addr; 600 if (cmd == GRESADDRS) 601 sc->g_src = (satosin(sa))->sin_addr; 602 if (cmd == GRESADDRD) 603 sc->g_dst = (satosin(sa))->sin_addr; 604 recompute: 605 #ifdef INET 606 if (sc->encap != NULL) { 607 encap_detach(sc->encap); 608 sc->encap = NULL; 609 } 610 #endif 611 if ((sc->g_src.s_addr != INADDR_ANY) && 612 (sc->g_dst.s_addr != INADDR_ANY)) { 613 bzero(&sp, sizeof(sp)); 614 bzero(&sm, sizeof(sm)); 615 bzero(&dp, sizeof(dp)); 616 bzero(&dm, sizeof(dm)); 617 sp.sin_len = sm.sin_len = dp.sin_len = dm.sin_len = 618 sizeof(struct sockaddr_in); 619 sp.sin_family = sm.sin_family = dp.sin_family = 620 dm.sin_family = AF_INET; 621 sp.sin_addr = sc->g_src; 622 dp.sin_addr = sc->g_dst; 623 sm.sin_addr.s_addr = dm.sin_addr.s_addr = 624 INADDR_BROADCAST; 625 #ifdef INET 626 sc->encap = encap_attach(AF_INET, sc->g_proto, 627 sintosa(&sp), sintosa(&sm), sintosa(&dp), 628 sintosa(&dm), (sc->g_proto == IPPROTO_GRE) ? 629 &in_gre_protosw : &in_mobile_protosw, sc); 630 if (sc->encap == NULL) 631 printf("%s: unable to attach encap\n", 632 if_name(GRE2IFP(sc))); 633 #endif 634 if (sc->route.ro_rt != 0) /* free old route */ 635 RTFREE(sc->route.ro_rt); 636 if (gre_compute_route(sc) == 0) 637 ifp->if_drv_flags |= IFF_DRV_RUNNING; 638 else 639 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 640 } 641 break; 642 case GREGADDRS: 643 memset(&si, 0, sizeof(si)); 644 si.sin_family = AF_INET; 645 si.sin_len = sizeof(struct sockaddr_in); 646 si.sin_addr.s_addr = sc->g_src.s_addr; 647 sa = sintosa(&si); 648 ifr->ifr_addr = *sa; 649 break; 650 case GREGADDRD: 651 memset(&si, 0, sizeof(si)); 652 si.sin_family = AF_INET; 653 si.sin_len = sizeof(struct sockaddr_in); 654 si.sin_addr.s_addr = sc->g_dst.s_addr; 655 sa = sintosa(&si); 656 ifr->ifr_addr = *sa; 657 break; 658 case SIOCSIFPHYADDR: 659 /* 660 * XXXRW: Isn't this priv_check() redundant to the ifnet 661 * layer check? 662 */ 663 if ((error = priv_check(curthread, PRIV_NET_SETIFPHYS)) != 0) 664 break; 665 if (aifr->ifra_addr.sin_family != AF_INET || 666 aifr->ifra_dstaddr.sin_family != AF_INET) { 667 error = EAFNOSUPPORT; 668 break; 669 } 670 if (aifr->ifra_addr.sin_len != sizeof(si) || 671 aifr->ifra_dstaddr.sin_len != sizeof(si)) { 672 error = EINVAL; 673 break; 674 } 675 sc->g_src = aifr->ifra_addr.sin_addr; 676 sc->g_dst = aifr->ifra_dstaddr.sin_addr; 677 goto recompute; 678 case SIOCSLIFPHYADDR: 679 /* 680 * XXXRW: Isn't this priv_check() redundant to the ifnet 681 * layer check? 682 */ 683 if ((error = priv_check(curthread, PRIV_NET_SETIFPHYS)) != 0) 684 break; 685 if (lifr->addr.ss_family != AF_INET || 686 lifr->dstaddr.ss_family != AF_INET) { 687 error = EAFNOSUPPORT; 688 break; 689 } 690 if (lifr->addr.ss_len != sizeof(si) || 691 lifr->dstaddr.ss_len != sizeof(si)) { 692 error = EINVAL; 693 break; 694 } 695 sc->g_src = (satosin(&lifr->addr))->sin_addr; 696 sc->g_dst = 697 (satosin(&lifr->dstaddr))->sin_addr; 698 goto recompute; 699 case SIOCDIFPHYADDR: 700 /* 701 * XXXRW: Isn't this priv_check() redundant to the ifnet 702 * layer check? 703 */ 704 if ((error = priv_check(curthread, PRIV_NET_SETIFPHYS)) != 0) 705 break; 706 sc->g_src.s_addr = INADDR_ANY; 707 sc->g_dst.s_addr = INADDR_ANY; 708 goto recompute; 709 case SIOCGLIFPHYADDR: 710 if (sc->g_src.s_addr == INADDR_ANY || 711 sc->g_dst.s_addr == INADDR_ANY) { 712 error = EADDRNOTAVAIL; 713 break; 714 } 715 memset(&si, 0, sizeof(si)); 716 si.sin_family = AF_INET; 717 si.sin_len = sizeof(struct sockaddr_in); 718 si.sin_addr.s_addr = sc->g_src.s_addr; 719 memcpy(&lifr->addr, &si, sizeof(si)); 720 si.sin_addr.s_addr = sc->g_dst.s_addr; 721 memcpy(&lifr->dstaddr, &si, sizeof(si)); 722 break; 723 case SIOCGIFPSRCADDR: 724 #ifdef INET6 725 case SIOCGIFPSRCADDR_IN6: 726 #endif 727 if (sc->g_src.s_addr == INADDR_ANY) { 728 error = EADDRNOTAVAIL; 729 break; 730 } 731 memset(&si, 0, sizeof(si)); 732 si.sin_family = AF_INET; 733 si.sin_len = sizeof(struct sockaddr_in); 734 si.sin_addr.s_addr = sc->g_src.s_addr; 735 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr)); 736 break; 737 case SIOCGIFPDSTADDR: 738 #ifdef INET6 739 case SIOCGIFPDSTADDR_IN6: 740 #endif 741 if (sc->g_dst.s_addr == INADDR_ANY) { 742 error = EADDRNOTAVAIL; 743 break; 744 } 745 memset(&si, 0, sizeof(si)); 746 si.sin_family = AF_INET; 747 si.sin_len = sizeof(struct sockaddr_in); 748 si.sin_addr.s_addr = sc->g_dst.s_addr; 749 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr)); 750 break; 751 case GRESKEY: 752 error = priv_check(curthread, PRIV_NET_GRE); 753 if (error) 754 break; 755 error = copyin(ifr->ifr_data, &key, sizeof(key)); 756 if (error) 757 break; 758 /* adjust MTU for option header */ 759 if (key == 0 && sc->key != 0) /* clear */ 760 adj += sizeof(key); 761 else if (key != 0 && sc->key == 0) /* set */ 762 adj -= sizeof(key); 763 764 if (ifp->if_mtu + adj < 576) { 765 error = EINVAL; 766 break; 767 } 768 ifp->if_mtu += adj; 769 sc->key = key; 770 break; 771 case GREGKEY: 772 error = copyout(&sc->key, ifr->ifr_data, sizeof(sc->key)); 773 break; 774 775 default: 776 error = EINVAL; 777 break; 778 } 779 780 splx(s); 781 return (error); 782 } 783 784 /* 785 * computes a route to our destination that is not the one 786 * which would be taken by ip_output(), as this one will loop back to 787 * us. If the interface is p2p as a--->b, then a routing entry exists 788 * If we now send a packet to b (e.g. ping b), this will come down here 789 * gets src=a, dst=b tacked on and would from ip_output() sent back to 790 * if_gre. 791 * Goal here is to compute a route to b that is less specific than 792 * a-->b. We know that this one exists as in normal operation we have 793 * at least a default route which matches. 794 */ 795 static int 796 gre_compute_route(struct gre_softc *sc) 797 { 798 struct route *ro; 799 800 ro = &sc->route; 801 802 memset(ro, 0, sizeof(struct route)); 803 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst; 804 ro->ro_dst.sa_family = AF_INET; 805 ro->ro_dst.sa_len = sizeof(ro->ro_dst); 806 807 /* 808 * toggle last bit, so our interface is not found, but a less 809 * specific route. I'd rather like to specify a shorter mask, 810 * but this is not possible. Should work though. XXX 811 * XXX MRT Use a different FIB for the tunnel to solve this problem. 812 */ 813 if ((GRE2IFP(sc)->if_flags & IFF_LINK1) == 0) { 814 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr.s_addr ^= 815 htonl(0x01); 816 } 817 818 #ifdef DIAGNOSTIC 819 printf("%s: searching for a route to %s", if_name(GRE2IFP(sc)), 820 inet_ntoa(((struct sockaddr_in *)&ro->ro_dst)->sin_addr)); 821 #endif 822 823 rtalloc_fib(ro, sc->gre_fibnum); 824 825 /* 826 * check if this returned a route at all and this route is no 827 * recursion to ourself 828 */ 829 if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp->if_softc == sc) { 830 #ifdef DIAGNOSTIC 831 if (ro->ro_rt == NULL) 832 printf(" - no route found!\n"); 833 else 834 printf(" - route loops back to ourself!\n"); 835 #endif 836 return EADDRNOTAVAIL; 837 } 838 839 /* 840 * now change it back - else ip_output will just drop 841 * the route and search one to this interface ... 842 */ 843 if ((GRE2IFP(sc)->if_flags & IFF_LINK1) == 0) 844 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst; 845 846 #ifdef DIAGNOSTIC 847 printf(", choosing %s with gateway %s", if_name(ro->ro_rt->rt_ifp), 848 inet_ntoa(((struct sockaddr_in *)(ro->ro_rt->rt_gateway))->sin_addr)); 849 printf("\n"); 850 #endif 851 852 return 0; 853 } 854 855 /* 856 * do a checksum of a buffer - much like in_cksum, which operates on 857 * mbufs. 858 */ 859 u_int16_t 860 gre_in_cksum(u_int16_t *p, u_int len) 861 { 862 u_int32_t sum = 0; 863 int nwords = len >> 1; 864 865 while (nwords-- != 0) 866 sum += *p++; 867 868 if (len & 1) { 869 union { 870 u_short w; 871 u_char c[2]; 872 } u; 873 u.c[0] = *(u_char *)p; 874 u.c[1] = 0; 875 sum += u.w; 876 } 877 878 /* end-around-carry */ 879 sum = (sum >> 16) + (sum & 0xffff); 880 sum += (sum >> 16); 881 return (~sum); 882 } 883 884 static int 885 gremodevent(module_t mod, int type, void *data) 886 { 887 888 switch (type) { 889 case MOD_LOAD: 890 greattach(); 891 break; 892 case MOD_UNLOAD: 893 if_clone_detach(&gre_cloner); 894 mtx_destroy(&gre_mtx); 895 break; 896 default: 897 return EOPNOTSUPP; 898 } 899 return 0; 900 } 901 902 static moduledata_t gre_mod = { 903 "if_gre", 904 gremodevent, 905 0 906 }; 907 908 DECLARE_MODULE(if_gre, gre_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 909 MODULE_VERSION(if_gre, 1); 910