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