1 /* $NetBSD: if_gre.c,v 1.42 2002/08/14 00:23:27 itojun Exp $ */ 2 /* $FreeBSD: src/sys/net/if_gre.c,v 1.9.2.3 2003/01/23 21:06:44 sam Exp $ */ 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 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the NetBSD 22 * Foundation, Inc. and its contributors. 23 * 4. Neither the name of The NetBSD Foundation nor the names of its 24 * contributors may be used to endorse or promote products derived 25 * from this software without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 37 * POSSIBILITY OF SUCH DAMAGE. 38 */ 39 40 /* 41 * Encapsulate L3 protocols into IP 42 * See RFC 1701 and 1702 for more details. 43 * If_gre is compatible with Cisco GRE tunnels, so you can 44 * have a NetBSD box as the other end of a tunnel interface of a Cisco 45 * router. See gre(4) for more details. 46 * Also supported: IP in IP encaps (proto 55) as of RFC 2004 47 */ 48 49 #include "opt_inet.h" 50 51 #include <sys/param.h> 52 #include <sys/kernel.h> 53 #include <sys/bus.h> 54 #include <sys/malloc.h> 55 #include <sys/mbuf.h> 56 #include <sys/proc.h> 57 #include <sys/caps.h> 58 #include <sys/protosw.h> 59 #include <sys/socket.h> 60 #include <sys/sockio.h> 61 #include <sys/sysctl.h> 62 #include <sys/systm.h> 63 #include <sys/thread2.h> 64 65 #include <net/ethernet.h> 66 #include <net/if.h> 67 #include <net/if_types.h> 68 #include <net/ifq_var.h> 69 #include <net/route.h> 70 #include <net/if_clone.h> 71 #include <net/netmsg2.h> 72 #include <net/netisr2.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/net_osdep.h> 89 #include "if_gre.h" 90 91 /* 92 * It is not easy to calculate the right value for a GRE MTU. 93 * We leave this task to the admin and use the same default that 94 * other vendors use. 95 */ 96 #define GREMTU 1476 97 98 #define GRENAME "gre" 99 100 #define MTAG_GRE 1709049137 /* mtag cookie for nesting check */ 101 102 static MALLOC_DEFINE(M_GRE, GRENAME, "Generic Routing Encapsulation"); 103 104 struct gre_softc_head gre_softc_list; 105 106 static int gre_clone_create(struct if_clone *, int, caddr_t, caddr_t); 107 static int gre_clone_destroy(struct ifnet *); 108 static int gre_ioctl(struct ifnet *, u_long, caddr_t, struct ucred *); 109 static int gre_output(struct ifnet *, struct mbuf *, struct sockaddr *, 110 struct rtentry *rt); 111 112 static struct if_clone gre_cloner = IF_CLONE_INITIALIZER("gre", 113 gre_clone_create, gre_clone_destroy, 0, IF_MAXUNIT); 114 115 static int gre_compute_route(struct gre_softc *sc, struct route *); 116 static int gre_check_route(struct gre_softc *sc); 117 118 static void greattach(void); 119 120 #ifdef INET 121 122 extern struct domain inetdomain; 123 124 static const struct protosw in_gre_protosw = 125 { 126 .pr_type = SOCK_RAW, 127 .pr_domain = &inetdomain, 128 .pr_protocol = IPPROTO_GRE, 129 .pr_flags = PR_ATOMIC|PR_ADDR, 130 131 .pr_input = gre_input, 132 .pr_output = rip_output, 133 .pr_ctlinput = NULL, 134 .pr_ctloutput = rip_ctloutput, 135 136 .pr_ctlport = NULL, 137 .pr_usrreqs = &rip_usrreqs 138 }; 139 140 static const struct protosw in_mobile_protosw = 141 { 142 .pr_type = SOCK_RAW, 143 .pr_domain = &inetdomain, 144 .pr_protocol = IPPROTO_MOBILE, 145 .pr_flags = PR_ATOMIC|PR_ADDR, 146 147 .pr_input = gre_mobile_input, 148 .pr_output = rip_output, 149 .pr_ctlinput = NULL, 150 .pr_ctloutput = rip_ctloutput, 151 152 .pr_ctlport = NULL, 153 .pr_usrreqs = &rip_usrreqs 154 }; 155 156 #endif 157 158 SYSCTL_DECL(_net_link); 159 SYSCTL_NODE(_net_link, IFT_OTHER, gre, CTLFLAG_RW, 0, 160 "Generic Routing Encapsulation"); 161 #ifndef MAX_GRE_NEST 162 /* 163 * This macro controls the default upper limitation on nesting of gre tunnels. 164 * Since, setting a large value to this macro with a careless configuration 165 * may introduce system crash, we don't allow any nestings by default. 166 * If you need to configure nested gre tunnels, you can define this macro 167 * in your kernel configuration file. However, if you do so, please be 168 * careful to configure the tunnels so that it won't make a loop. 169 */ 170 #define MAX_GRE_NEST 1 171 #endif 172 static int max_gre_nesting = MAX_GRE_NEST; 173 SYSCTL_INT(_net_link_gre, OID_AUTO, max_nesting, CTLFLAG_RW, 174 &max_gre_nesting, 0, "Max nested tunnels"); 175 176 /* ARGSUSED */ 177 static void 178 greattach(void) 179 { 180 181 LIST_INIT(&gre_softc_list); 182 if_clone_attach(&gre_cloner); 183 } 184 185 static int 186 gre_clone_create(struct if_clone *ifc, int unit, 187 caddr_t params __unused, caddr_t data __unused) 188 { 189 struct gre_softc *sc; 190 191 sc = kmalloc(sizeof(struct gre_softc), M_GRE, M_WAITOK); 192 memset(sc, 0, sizeof(struct gre_softc)); 193 194 sc->sc_if.if_softc = sc; 195 if_initname(&(sc->sc_if), GRENAME, unit); 196 ifq_set_maxlen(&sc->sc_if.if_snd, IFQ_MAXLEN); 197 sc->sc_if.if_type = IFT_OTHER; 198 sc->sc_if.if_addrlen = 0; 199 sc->sc_if.if_hdrlen = 24; /* IP + GRE */ 200 sc->sc_if.if_mtu = GREMTU; 201 sc->sc_if.if_flags = IFF_POINTOPOINT|IFF_MULTICAST; 202 sc->sc_if.if_output = gre_output; 203 sc->sc_if.if_ioctl = gre_ioctl; 204 sc->g_dst.s_addr = sc->g_src.s_addr = INADDR_ANY; 205 sc->g_proto = IPPROTO_GRE; 206 sc->sc_if.if_flags |= IFF_LINK0; 207 sc->encap = NULL; 208 sc->route_pcpu = kmalloc(netisr_ncpus * sizeof(struct route), M_GRE, 209 M_WAITOK | M_ZERO); 210 if_attach(&sc->sc_if, NULL); 211 bpfattach(&sc->sc_if, DLT_NULL, sizeof(u_int32_t)); 212 LIST_INSERT_HEAD(&gre_softc_list, sc, sc_list); 213 return (0); 214 } 215 216 static int 217 gre_clone_destroy(struct ifnet *ifp) 218 { 219 struct gre_softc *sc = ifp->if_softc; 220 int cpu; 221 222 #ifdef INET 223 if (sc->encap != NULL) 224 encap_detach(sc->encap); 225 #endif 226 LIST_REMOVE(sc, sc_list); 227 bpfdetach(ifp); 228 if_detach(ifp); 229 230 for (cpu = 0; cpu < netisr_ncpus; ++cpu) { 231 if (sc->route_pcpu[cpu].ro_rt != NULL) { 232 rtfree_async(sc->route_pcpu[cpu].ro_rt); 233 sc->route_pcpu[cpu].ro_rt = NULL; 234 } 235 } 236 kfree(sc->route_pcpu, M_GRE); 237 kfree(sc, M_GRE); 238 239 return 0; 240 } 241 242 /* 243 * The output routine. Takes a packet and encapsulates it in the protocol 244 * given by sc->g_proto. See also RFC 1701 and RFC 2004 245 */ 246 static int 247 gre_output_serialized(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 248 struct rtentry *rt) 249 { 250 int error = 0; 251 struct gre_softc *sc = ifp->if_softc; 252 struct greip *gh; 253 struct ip *ip; 254 u_short etype = 0; 255 struct mobile_h mob_h; 256 struct route *ro; 257 struct sockaddr_in *ro_dst; 258 259 ASSERT_NETISR_NCPUS(mycpuid); 260 261 error = if_tunnel_check_nesting(ifp, m, MTAG_GRE, max_gre_nesting); 262 if (error != 0) { 263 m_freem(m); 264 goto end; 265 } 266 267 if ((ifp->if_flags & (IFF_UP | IFF_RUNNING)) == 0 || 268 sc->g_src.s_addr == INADDR_ANY || sc->g_dst.s_addr == INADDR_ANY) { 269 m_freem(m); 270 error = ENETDOWN; 271 goto end; 272 } 273 274 ro = &sc->route_pcpu[mycpuid]; 275 ro_dst = (struct sockaddr_in *)&ro->ro_dst; 276 if (ro->ro_rt != NULL && 277 ((ro->ro_rt->rt_flags & RTF_UP) == 0 || 278 ro_dst->sin_addr.s_addr != sc->g_dst.s_addr)) { 279 RTFREE(ro->ro_rt); 280 ro->ro_rt = NULL; 281 } 282 if (ro->ro_rt == NULL) { 283 error = gre_compute_route(sc, ro); 284 if (error) { 285 m_freem(m); 286 goto end; 287 } 288 } 289 290 gh = NULL; 291 ip = NULL; 292 293 if (ifp->if_bpf) { 294 bpf_gettoken(); 295 if (ifp->if_bpf) { 296 uint32_t af = dst->sa_family; 297 298 bpf_ptap(ifp->if_bpf, m, &af, sizeof(af)); 299 } 300 bpf_reltoken(); 301 } 302 303 m->m_flags &= ~(M_BCAST|M_MCAST); 304 305 if (sc->g_proto == IPPROTO_MOBILE) { 306 if (dst->sa_family == AF_INET) { 307 struct mbuf *m0; 308 int msiz; 309 310 ip = mtod(m, struct ip *); 311 312 /* 313 * RFC2004 specifies that fragmented datagrams shouldn't 314 * be encapsulated. 315 */ 316 if (ip->ip_off & htons(IP_MF | IP_OFFMASK)) { 317 m_freem(m); 318 error = EINVAL; /* is there better errno? */ 319 goto end; 320 } 321 memset(&mob_h, 0, MOB_H_SIZ_L); 322 mob_h.proto = (ip->ip_p) << 8; 323 mob_h.odst = ip->ip_dst.s_addr; 324 ip->ip_dst.s_addr = sc->g_dst.s_addr; 325 326 /* 327 * If the packet comes from our host, we only change 328 * the destination address in the IP header. 329 * Else we also need to save and change the source 330 */ 331 if (in_hosteq(ip->ip_src, sc->g_src)) { 332 msiz = MOB_H_SIZ_S; 333 } else { 334 mob_h.proto |= MOB_H_SBIT; 335 mob_h.osrc = ip->ip_src.s_addr; 336 ip->ip_src.s_addr = sc->g_src.s_addr; 337 msiz = MOB_H_SIZ_L; 338 } 339 mob_h.proto = htons(mob_h.proto); 340 mob_h.hcrc = gre_in_cksum((u_short *)&mob_h, msiz); 341 342 if ((m->m_data - msiz) < m->m_pktdat) { 343 /* need new mbuf */ 344 MGETHDR(m0, M_NOWAIT, MT_HEADER); 345 if (m0 == NULL) { 346 m_freem(m); 347 error = ENOBUFS; 348 goto end; 349 } 350 m0->m_next = m; 351 m->m_data += sizeof(struct ip); 352 m->m_len -= sizeof(struct ip); 353 m0->m_pkthdr.len = m->m_pkthdr.len + msiz; 354 m0->m_len = msiz + sizeof(struct ip); 355 m0->m_data += max_linkhdr; 356 memcpy(mtod(m0, caddr_t), (caddr_t)ip, 357 sizeof(struct ip)); 358 m = m0; 359 } else { /* we have some space left in the old one */ 360 m->m_data -= msiz; 361 m->m_len += msiz; 362 m->m_pkthdr.len += msiz; 363 bcopy(ip, mtod(m, caddr_t), 364 sizeof(struct ip)); 365 } 366 ip = mtod(m, struct ip *); 367 memcpy((caddr_t)(ip + 1), &mob_h, (unsigned)msiz); 368 ip->ip_len = htons(ntohs(ip->ip_len) + msiz); 369 } else { /* AF_INET */ 370 m_freem(m); 371 error = EINVAL; 372 goto end; 373 } 374 } else if (sc->g_proto == IPPROTO_GRE) { 375 switch (dst->sa_family) { 376 case AF_INET: 377 ip = mtod(m, struct ip *); 378 etype = ETHERTYPE_IP; 379 break; 380 default: 381 m_freem(m); 382 error = EAFNOSUPPORT; 383 goto end; 384 } 385 M_PREPEND(m, sizeof(struct greip), M_NOWAIT); 386 } else { 387 m_freem(m); 388 error = EINVAL; 389 goto end; 390 } 391 392 if (m == NULL) { /* impossible */ 393 error = ENOBUFS; 394 goto end; 395 } 396 397 gh = mtod(m, struct greip *); 398 if (sc->g_proto == IPPROTO_GRE) { 399 /* we don't have any GRE flags for now */ 400 401 memset((void *)&gh->gi_g, 0, sizeof(struct gre_h)); 402 gh->gi_ptype = htons(etype); 403 } 404 405 gh->gi_pr = sc->g_proto; 406 if (sc->g_proto != IPPROTO_MOBILE) { 407 gh->gi_src = sc->g_src; 408 gh->gi_dst = sc->g_dst; 409 ((struct ip*)gh)->ip_hl = (sizeof(struct ip)) >> 2; 410 ((struct ip*)gh)->ip_ttl = GRE_TTL; 411 ((struct ip*)gh)->ip_tos = ip->ip_tos; 412 ((struct ip*)gh)->ip_id = ip->ip_id; 413 gh->gi_len = htons(m->m_pkthdr.len); 414 } 415 416 IFNET_STAT_INC(ifp, opackets, 1); 417 IFNET_STAT_INC(ifp, obytes, m->m_pkthdr.len); 418 /* send it off */ 419 error = ip_output(m, NULL, ro, IP_DEBUGROUTE, NULL, NULL); 420 end: 421 if (error) 422 IFNET_STAT_INC(ifp, oerrors, 1); 423 return (error); 424 } 425 426 static int 427 gre_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 428 struct rtentry *rt) 429 { 430 struct ifaltq_subque *ifsq = ifq_get_subq_default(&ifp->if_snd); 431 int error; 432 433 ifsq_serialize_hw(ifsq); 434 error = gre_output_serialized(ifp, m, dst, rt); 435 ifsq_deserialize_hw(ifsq); 436 437 return error; 438 } 439 440 static int 441 gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr) 442 { 443 struct ifreq *ifr = (struct ifreq *)data; 444 struct if_laddrreq *lifr = (struct if_laddrreq *)data; 445 struct in_aliasreq *aifr = (struct in_aliasreq *)data; 446 struct gre_softc *sc = ifp->if_softc; 447 struct sockaddr_in si; 448 struct sockaddr *sa = NULL; 449 int error; 450 struct sockaddr_in sp, sm, dp, dm; 451 452 error = 0; 453 454 crit_enter(); 455 switch (cmd) { 456 case SIOCSIFADDR: 457 ifp->if_flags |= IFF_UP; 458 break; 459 case SIOCSIFDSTADDR: 460 break; 461 case SIOCSIFFLAGS: 462 error = caps_priv_check(cr, SYSCAP_RESTRICTEDROOT | 463 __SYSCAP_NULLCRED); 464 if (error) 465 break; 466 if ((ifr->ifr_flags & IFF_LINK0) != 0) 467 sc->g_proto = IPPROTO_GRE; 468 else 469 sc->g_proto = IPPROTO_MOBILE; 470 goto recompute; 471 case SIOCSIFMTU: 472 error = caps_priv_check(cr, SYSCAP_RESTRICTEDROOT | 473 __SYSCAP_NULLCRED); 474 if (error) 475 break; 476 if (ifr->ifr_mtu < 576) { 477 error = EINVAL; 478 break; 479 } 480 ifp->if_mtu = ifr->ifr_mtu; 481 break; 482 case SIOCGIFMTU: 483 ifr->ifr_mtu = sc->sc_if.if_mtu; 484 break; 485 case SIOCADDMULTI: 486 case SIOCDELMULTI: 487 error = caps_priv_check(cr, SYSCAP_RESTRICTEDROOT | 488 __SYSCAP_NULLCRED); 489 if (error) 490 break; 491 if (ifr == NULL) { 492 error = EAFNOSUPPORT; 493 break; 494 } 495 switch (ifr->ifr_addr.sa_family) { 496 #ifdef INET 497 case AF_INET: 498 break; 499 #endif 500 default: 501 error = EAFNOSUPPORT; 502 break; 503 } 504 break; 505 case GRESPROTO: 506 error = caps_priv_check(cr, SYSCAP_RESTRICTEDROOT | 507 __SYSCAP_NULLCRED); 508 if (error) 509 break; 510 sc->g_proto = ifr->ifr_flags; 511 switch (sc->g_proto) { 512 case IPPROTO_GRE: 513 ifp->if_flags |= IFF_LINK0; 514 break; 515 case IPPROTO_MOBILE: 516 ifp->if_flags &= ~IFF_LINK0; 517 break; 518 default: 519 error = EPROTONOSUPPORT; 520 break; 521 } 522 goto recompute; 523 case GREGPROTO: 524 ifr->ifr_flags = sc->g_proto; 525 break; 526 case GRESADDRS: 527 case GRESADDRD: 528 error = caps_priv_check(cr, SYSCAP_RESTRICTEDROOT | 529 __SYSCAP_NULLCRED); 530 if (error) 531 break; 532 /* 533 * set tunnel endpoints, compute a less specific route 534 * to the remote end and mark if as up 535 */ 536 sa = &ifr->ifr_addr; 537 if (cmd == GRESADDRS) 538 sc->g_src = (satosin(sa))->sin_addr; 539 if (cmd == GRESADDRD) 540 sc->g_dst = (satosin(sa))->sin_addr; 541 recompute: 542 #ifdef INET 543 if (sc->encap != NULL) { 544 encap_detach(sc->encap); 545 sc->encap = NULL; 546 } 547 #endif 548 if ((sc->g_src.s_addr != INADDR_ANY) && 549 (sc->g_dst.s_addr != INADDR_ANY)) { 550 bzero(&sp, sizeof(sp)); 551 bzero(&sm, sizeof(sm)); 552 bzero(&dp, sizeof(dp)); 553 bzero(&dm, sizeof(dm)); 554 sp.sin_len = sm.sin_len = dp.sin_len = dm.sin_len = 555 sizeof(struct sockaddr_in); 556 sp.sin_family = sm.sin_family = dp.sin_family = 557 dm.sin_family = AF_INET; 558 sp.sin_addr = sc->g_src; 559 dp.sin_addr = sc->g_dst; 560 sm.sin_addr.s_addr = dm.sin_addr.s_addr = 561 INADDR_BROADCAST; 562 #ifdef INET 563 sc->encap = encap_attach(AF_INET, sc->g_proto, 564 sintosa(&sp), sintosa(&sm), sintosa(&dp), 565 sintosa(&dm), (sc->g_proto == IPPROTO_GRE) ? 566 &in_gre_protosw : &in_mobile_protosw, sc); 567 if (sc->encap == NULL) 568 kprintf("%s: unable to attach encap\n", 569 if_name(&sc->sc_if)); 570 #endif 571 ifnet_deserialize_all(ifp); 572 error = gre_check_route(sc); 573 ifnet_serialize_all(ifp); 574 if (!error) 575 ifp->if_flags |= IFF_RUNNING; 576 else 577 ifp->if_flags &= ~IFF_RUNNING; 578 } 579 break; 580 case GREGADDRS: 581 memset(&si, 0, sizeof(si)); 582 si.sin_family = AF_INET; 583 si.sin_len = sizeof(struct sockaddr_in); 584 si.sin_addr.s_addr = sc->g_src.s_addr; 585 sa = sintosa(&si); 586 ifr->ifr_addr = *sa; 587 break; 588 case GREGADDRD: 589 memset(&si, 0, sizeof(si)); 590 si.sin_family = AF_INET; 591 si.sin_len = sizeof(struct sockaddr_in); 592 si.sin_addr.s_addr = sc->g_dst.s_addr; 593 sa = sintosa(&si); 594 ifr->ifr_addr = *sa; 595 break; 596 case SIOCSIFPHYADDR: 597 error = caps_priv_check(cr, SYSCAP_RESTRICTEDROOT | 598 __SYSCAP_NULLCRED); 599 if (error) 600 break; 601 if (aifr->ifra_addr.sin_family != AF_INET || 602 aifr->ifra_dstaddr.sin_family != AF_INET) 603 { 604 error = EAFNOSUPPORT; 605 break; 606 } 607 if (aifr->ifra_addr.sin_len != sizeof(si) || 608 aifr->ifra_dstaddr.sin_len != sizeof(si)) 609 { 610 error = EINVAL; 611 break; 612 } 613 sc->g_src = aifr->ifra_addr.sin_addr; 614 sc->g_dst = aifr->ifra_dstaddr.sin_addr; 615 goto recompute; 616 case SIOCSLIFPHYADDR: 617 error = caps_priv_check(cr, SYSCAP_RESTRICTEDROOT | 618 __SYSCAP_NULLCRED); 619 if (error) 620 break; 621 if (lifr->addr.ss_family != AF_INET || 622 lifr->dstaddr.ss_family != AF_INET) { 623 error = EAFNOSUPPORT; 624 break; 625 } 626 if (lifr->addr.ss_len != sizeof(si) || 627 lifr->dstaddr.ss_len != sizeof(si)) { 628 error = EINVAL; 629 break; 630 } 631 sc->g_src = (satosin((struct sockadrr *)&lifr->addr))->sin_addr; 632 sc->g_dst = 633 (satosin((struct sockadrr *)&lifr->dstaddr))->sin_addr; 634 goto recompute; 635 case SIOCDIFPHYADDR: 636 error = caps_priv_check(cr, SYSCAP_RESTRICTEDROOT | 637 __SYSCAP_NULLCRED); 638 if (error) 639 break; 640 sc->g_src.s_addr = INADDR_ANY; 641 sc->g_dst.s_addr = INADDR_ANY; 642 goto recompute; 643 case SIOCGLIFPHYADDR: 644 if (sc->g_src.s_addr == INADDR_ANY || 645 sc->g_dst.s_addr == INADDR_ANY) { 646 error = EADDRNOTAVAIL; 647 break; 648 } 649 memset(&si, 0, sizeof(si)); 650 si.sin_family = AF_INET; 651 si.sin_len = sizeof(struct sockaddr_in); 652 si.sin_addr.s_addr = sc->g_src.s_addr; 653 memcpy(&lifr->addr, &si, sizeof(si)); 654 si.sin_addr.s_addr = sc->g_dst.s_addr; 655 memcpy(&lifr->dstaddr, &si, sizeof(si)); 656 break; 657 case SIOCGIFPSRCADDR: 658 if (sc->g_src.s_addr == INADDR_ANY) { 659 error = EADDRNOTAVAIL; 660 break; 661 } 662 memset(&si, 0, sizeof(si)); 663 si.sin_family = AF_INET; 664 si.sin_len = sizeof(struct sockaddr_in); 665 si.sin_addr.s_addr = sc->g_src.s_addr; 666 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr)); 667 break; 668 case SIOCGIFPDSTADDR: 669 if (sc->g_dst.s_addr == INADDR_ANY) { 670 error = EADDRNOTAVAIL; 671 break; 672 } 673 memset(&si, 0, sizeof(si)); 674 si.sin_family = AF_INET; 675 si.sin_len = sizeof(struct sockaddr_in); 676 si.sin_addr.s_addr = sc->g_dst.s_addr; 677 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr)); 678 break; 679 default: 680 error = EINVAL; 681 break; 682 } 683 684 crit_exit(); 685 return (error); 686 } 687 688 /* 689 * computes a route to our destination that is not the one 690 * which would be taken by ip_output(), as this one will loop back to 691 * us. If the interface is p2p as a--->b, then a routing entry exists 692 * If we now send a packet to b (e.g. ping b), this will come down here 693 * gets src=a, dst=b tacked on and would from ip_ouput() sent back to 694 * if_gre. 695 * Goal here is to compute a route to b that is less specific than 696 * a-->b. We know that this one exists as in normal operation we have 697 * at least a default route which matches. 698 */ 699 static int 700 gre_compute_route(struct gre_softc *sc, struct route *ro) 701 { 702 #ifdef DIAGNOSTIC 703 char abuf[INET_ADDRSTRLEN]; 704 #endif 705 u_int32_t a, b, c; 706 707 ASSERT_NETISR_NCPUS(mycpuid); 708 KASSERT(ro == &sc->route_pcpu[mycpuid], ("route mismatch")); 709 KASSERT(ro->ro_rt == NULL, ("rtentry not freed")); 710 711 memset(ro, 0, sizeof(struct route)); 712 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst; 713 ro->ro_dst.sa_family = AF_INET; 714 ro->ro_dst.sa_len = sizeof(ro->ro_dst); 715 716 /* 717 * toggle last bit, so our interface is not found, but a less 718 * specific route. I'd rather like to specify a shorter mask, 719 * but this is not possible. Should work though. XXX 720 * there is a simpler way ... 721 */ 722 if ((sc->sc_if.if_flags & IFF_LINK1) == 0) { 723 a = ntohl(sc->g_dst.s_addr); 724 b = a & 0x01; 725 c = a & 0xfffffffe; 726 b = b ^ 0x01; 727 a = b | c; 728 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr.s_addr 729 = htonl(a); 730 } 731 732 #ifdef DIAGNOSTIC 733 kprintf("%s: searching a route to %s", if_name(&sc->sc_if), 734 kinet_ntoa(((struct sockaddr_in *)&ro->ro_dst)->sin_addr, abuf)); 735 #endif 736 737 rtalloc(ro); 738 739 /* 740 * check if this returned a route at all and this route is no 741 * recursion to ourself 742 */ 743 if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp->if_softc == sc) { 744 #ifdef DIAGNOSTIC 745 if (ro->ro_rt == NULL) 746 kprintf(" - no route found!\n"); 747 else 748 kprintf(" - route loops back to ourself!\n"); 749 #endif 750 return EADDRNOTAVAIL; 751 } 752 753 /* 754 * now change it back - else ip_output will just drop 755 * the route and search one to this interface ... 756 */ 757 if ((sc->sc_if.if_flags & IFF_LINK1) == 0) 758 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst; 759 760 #ifdef DIAGNOSTIC 761 kprintf(", choosing %s with gateway %s", if_name(ro->ro_rt->rt_ifp), 762 kinet_ntoa( 763 ((struct sockaddr_in *)(ro->ro_rt->rt_gateway))->sin_addr, abuf)); 764 kprintf("\n"); 765 #endif 766 767 return 0; 768 } 769 770 static void 771 gre_check_route_handler(netmsg_t msg) 772 { 773 struct gre_softc *sc = msg->base.lmsg.u.ms_resultp; 774 struct route *ro; 775 int error; 776 777 ASSERT_NETISR0; 778 779 ro = &sc->route_pcpu[mycpuid]; 780 if (ro->ro_rt != NULL) { 781 RTFREE(ro->ro_rt); 782 ro->ro_rt = NULL; 783 } 784 error = gre_compute_route(sc, ro); 785 786 netisr_replymsg(&msg->base, error); 787 } 788 789 static int 790 gre_check_route(struct gre_softc *sc) 791 { 792 struct netmsg_base msg; 793 794 netmsg_init(&msg, NULL, &curthread->td_msgport, MSGF_PRIORITY, 795 gre_check_route_handler); 796 msg.lmsg.u.ms_resultp = sc; 797 798 return (netisr_domsg(&msg, 0)); 799 } 800 801 /* 802 * do a checksum of a buffer - much like in_cksum, which operates on 803 * mbufs. 804 */ 805 u_short 806 gre_in_cksum(u_short *p, u_int len) 807 { 808 u_int sum = 0; 809 int nwords = len >> 1; 810 811 while (nwords-- != 0) 812 sum += *p++; 813 814 if (len & 1) { 815 union { 816 u_short w; 817 u_char c[2]; 818 } u; 819 u.c[0] = *(u_char *)p; 820 u.c[1] = 0; 821 sum += u.w; 822 } 823 824 /* end-around-carry */ 825 sum = (sum >> 16) + (sum & 0xffff); 826 sum += (sum >> 16); 827 return (~sum); 828 } 829 830 static int 831 gremodevent(module_t mod, int type, void *data) 832 { 833 834 switch (type) { 835 case MOD_LOAD: 836 greattach(); 837 break; 838 case MOD_UNLOAD: 839 if_clone_detach(&gre_cloner); 840 841 while (!LIST_EMPTY(&gre_softc_list)) 842 gre_clone_destroy(&LIST_FIRST(&gre_softc_list)->sc_if); 843 844 break; 845 } 846 return 0; 847 } 848 849 static moduledata_t gre_mod = { 850 "if_gre", 851 gremodevent, 852 0 853 }; 854 855 DECLARE_MODULE(if_gre, gre_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 856 MODULE_VERSION(if_gre, 1); 857