ip_mroute.c revision 1541
1/* 2 * Copyright (c) 1989 Stephen Deering 3 * Copyright (c) 1992, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * Stephen Deering of Stanford University. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed by the University of 20 * California, Berkeley and its contributors. 21 * 4. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 * 37 * @(#)ip_mroute.c 8.2 (Berkeley) 11/15/93 38 */ 39 40/* 41 * Procedures for the kernel part of DVMRP, 42 * a Distance-Vector Multicast Routing Protocol. 43 * (See RFC-1075.) 44 * 45 * Written by David Waitzman, BBN Labs, August 1988. 46 * Modified by Steve Deering, Stanford, February 1989. 47 * 48 * MROUTING 1.1 49 */ 50 51#ifndef MROUTING 52int ip_mrtproto; /* for netstat only */ 53#else 54 55#include <sys/param.h> 56#include <sys/errno.h> 57#include <sys/ioctl.h> 58#include <sys/malloc.h> 59#include <sys/mbuf.h> 60#include <sys/protosw.h> 61#include <sys/socket.h> 62#include <sys/socketvar.h> 63#include <sys/time.h> 64 65#include <net/if.h> 66#include <net/route.h> 67#include <net/raw_cb.h> 68 69#include <netinet/in.h> 70#include <netinet/in_systm.h> 71#include <netinet/ip.h> 72#include <netinet/in_pcb.h> 73#include <netinet/in_var.h> 74#include <netinet/ip_var.h> 75 76#include <netinet/igmp.h> 77#include <netinet/igmp_var.h> 78#include <netinet/ip_mroute.h> 79 80/* Static forwards */ 81static int ip_mrouter_init __P((struct socket *)); 82static int add_vif __P((struct vifctl *)); 83static int del_vif __P((vifi_t *vifip)); 84static int add_lgrp __P((struct lgrplctl *)); 85static int del_lgrp __P((struct lgrplctl *)); 86static int grplst_member __P((struct vif *, struct in_addr)); 87static u_long nethash __P((struct in_addr in)); 88static int add_mrt __P((struct mrtctl *)); 89static int del_mrt __P((struct in_addr *)); 90static struct mrt *mrtfind __P((struct in_addr)); 91static void phyint_send __P((struct mbuf *, struct vif *)); 92static void tunnel_send __P((struct mbuf *, struct vif *)); 93 94#define INSIZ sizeof(struct in_addr) 95#define same(a1, a2) (bcmp((caddr_t)(a1), (caddr_t)(a2), INSIZ) == 0) 96#define satosin(sa) ((struct sockaddr_in *)(sa)) 97 98/* 99 * Globals. All but ip_mrouter and ip_mrtproto could be static, 100 * except for netstat or debugging purposes. 101 */ 102struct socket *ip_mrouter = NULL; 103int ip_mrtproto = IGMP_DVMRP; /* for netstat only */ 104 105struct mrt *mrttable[MRTHASHSIZ]; 106struct vif viftable[MAXVIFS]; 107struct mrtstat mrtstat; 108 109/* 110 * Private variables. 111 */ 112static vifi_t numvifs = 0; 113static struct mrt *cached_mrt = NULL; 114static u_long cached_origin; 115static u_long cached_originmask; 116 117/* 118 * Handle DVMRP setsockopt commands to modify the multicast routing tables. 119 */ 120int 121ip_mrouter_cmd(cmd, so, m) 122 register int cmd; 123 register struct socket *so; 124 register struct mbuf *m; 125{ 126 register int error = 0; 127 128 if (cmd != DVMRP_INIT && so != ip_mrouter) 129 error = EACCES; 130 else switch (cmd) { 131 132 case DVMRP_INIT: 133 error = ip_mrouter_init(so); 134 break; 135 136 case DVMRP_DONE: 137 error = ip_mrouter_done(); 138 break; 139 140 case DVMRP_ADD_VIF: 141 if (m == NULL || m->m_len < sizeof(struct vifctl)) 142 error = EINVAL; 143 else 144 error = add_vif(mtod(m, struct vifctl *)); 145 break; 146 147 case DVMRP_DEL_VIF: 148 if (m == NULL || m->m_len < sizeof(short)) 149 error = EINVAL; 150 else 151 error = del_vif(mtod(m, vifi_t *)); 152 break; 153 154 case DVMRP_ADD_LGRP: 155 if (m == NULL || m->m_len < sizeof(struct lgrplctl)) 156 error = EINVAL; 157 else 158 error = add_lgrp(mtod(m, struct lgrplctl *)); 159 break; 160 161 case DVMRP_DEL_LGRP: 162 if (m == NULL || m->m_len < sizeof(struct lgrplctl)) 163 error = EINVAL; 164 else 165 error = del_lgrp(mtod(m, struct lgrplctl *)); 166 break; 167 168 case DVMRP_ADD_MRT: 169 if (m == NULL || m->m_len < sizeof(struct mrtctl)) 170 error = EINVAL; 171 else 172 error = add_mrt(mtod(m, struct mrtctl *)); 173 break; 174 175 case DVMRP_DEL_MRT: 176 if (m == NULL || m->m_len < sizeof(struct in_addr)) 177 error = EINVAL; 178 else 179 error = del_mrt(mtod(m, struct in_addr *)); 180 break; 181 182 default: 183 error = EOPNOTSUPP; 184 break; 185 } 186 return (error); 187} 188 189/* 190 * Enable multicast routing 191 */ 192static int 193ip_mrouter_init(so) 194 register struct socket *so; 195{ 196 if (so->so_type != SOCK_RAW || 197 so->so_proto->pr_protocol != IPPROTO_IGMP) 198 return (EOPNOTSUPP); 199 200 if (ip_mrouter != NULL) 201 return (EADDRINUSE); 202 203 ip_mrouter = so; 204 205 return (0); 206} 207 208/* 209 * Disable multicast routing 210 */ 211int 212ip_mrouter_done() 213{ 214 register vifi_t vifi; 215 register int i; 216 register struct ifnet *ifp; 217 register int s; 218 struct ifreq ifr; 219 220 s = splnet(); 221 222 /* 223 * For each phyint in use, free its local group list and 224 * disable promiscuous reception of all IP multicasts. 225 */ 226 for (vifi = 0; vifi < numvifs; vifi++) { 227 if (viftable[vifi].v_lcl_addr.s_addr != 0 && 228 !(viftable[vifi].v_flags & VIFF_TUNNEL)) { 229 if (viftable[vifi].v_lcl_grps) 230 free(viftable[vifi].v_lcl_grps, M_MRTABLE); 231 satosin(&ifr.ifr_addr)->sin_family = AF_INET; 232 satosin(&ifr.ifr_addr)->sin_addr.s_addr = INADDR_ANY; 233 ifp = viftable[vifi].v_ifp; 234 (*ifp->if_ioctl)(ifp, SIOCDELMULTI, (caddr_t)&ifr); 235 } 236 } 237 bzero((caddr_t)viftable, sizeof(viftable)); 238 numvifs = 0; 239 240 /* 241 * Free any multicast route entries. 242 */ 243 for (i = 0; i < MRTHASHSIZ; i++) 244 if (mrttable[i]) 245 free(mrttable[i], M_MRTABLE); 246 bzero((caddr_t)mrttable, sizeof(mrttable)); 247 cached_mrt = NULL; 248 249 ip_mrouter = NULL; 250 251 splx(s); 252 return (0); 253} 254 255/* 256 * Add a vif to the vif table 257 */ 258static int 259add_vif(vifcp) 260 register struct vifctl *vifcp; 261{ 262 register struct vif *vifp = viftable + vifcp->vifc_vifi; 263 register struct ifaddr *ifa; 264 register struct ifnet *ifp; 265 struct ifreq ifr; 266 register int error, s; 267 static struct sockaddr_in sin = { sizeof(sin), AF_INET }; 268 269 if (vifcp->vifc_vifi >= MAXVIFS) 270 return (EINVAL); 271 if (vifp->v_lcl_addr.s_addr != 0) 272 return (EADDRINUSE); 273 274 /* Find the interface with an address in AF_INET family */ 275 sin.sin_addr = vifcp->vifc_lcl_addr; 276 ifa = ifa_ifwithaddr((struct sockaddr *)&sin); 277 if (ifa == 0) 278 return (EADDRNOTAVAIL); 279 280 s = splnet(); 281 282 if (vifcp->vifc_flags & VIFF_TUNNEL) 283 vifp->v_rmt_addr = vifcp->vifc_rmt_addr; 284 else { 285 /* Make sure the interface supports multicast */ 286 ifp = ifa->ifa_ifp; 287 if ((ifp->if_flags & IFF_MULTICAST) == 0) { 288 splx(s); 289 return (EOPNOTSUPP); 290 } 291 /* 292 * Enable promiscuous reception of all IP multicasts 293 * from the interface. 294 */ 295 satosin(&ifr.ifr_addr)->sin_family = AF_INET; 296 satosin(&ifr.ifr_addr)->sin_addr.s_addr = INADDR_ANY; 297 error = (*ifp->if_ioctl)(ifp, SIOCADDMULTI, (caddr_t)&ifr); 298 if (error) { 299 splx(s); 300 return (error); 301 } 302 } 303 304 vifp->v_flags = vifcp->vifc_flags; 305 vifp->v_threshold = vifcp->vifc_threshold; 306 vifp->v_lcl_addr = vifcp->vifc_lcl_addr; 307 vifp->v_ifp = ifa->ifa_ifp; 308 309 /* Adjust numvifs up if the vifi is higher than numvifs */ 310 if (numvifs <= vifcp->vifc_vifi) 311 numvifs = vifcp->vifc_vifi + 1; 312 313 splx(s); 314 return (0); 315} 316 317/* 318 * Delete a vif from the vif table 319 */ 320static int 321del_vif(vifip) 322 register vifi_t *vifip; 323{ 324 register struct vif *vifp = viftable + *vifip; 325 register struct ifnet *ifp; 326 register int i, s; 327 struct ifreq ifr; 328 329 if (*vifip >= numvifs) 330 return (EINVAL); 331 if (vifp->v_lcl_addr.s_addr == 0) 332 return (EADDRNOTAVAIL); 333 334 s = splnet(); 335 336 if (!(vifp->v_flags & VIFF_TUNNEL)) { 337 if (vifp->v_lcl_grps) 338 free(vifp->v_lcl_grps, M_MRTABLE); 339 satosin(&ifr.ifr_addr)->sin_family = AF_INET; 340 satosin(&ifr.ifr_addr)->sin_addr.s_addr = INADDR_ANY; 341 ifp = vifp->v_ifp; 342 (*ifp->if_ioctl)(ifp, SIOCDELMULTI, (caddr_t)&ifr); 343 } 344 345 bzero((caddr_t)vifp, sizeof (*vifp)); 346 347 /* Adjust numvifs down */ 348 for (i = numvifs - 1; i >= 0; i--) 349 if (viftable[i].v_lcl_addr.s_addr != 0) 350 break; 351 numvifs = i + 1; 352 353 splx(s); 354 return (0); 355} 356 357/* 358 * Add the multicast group in the lgrpctl to the list of local multicast 359 * group memberships associated with the vif indexed by gcp->lgc_vifi. 360 */ 361static int 362add_lgrp(gcp) 363 register struct lgrplctl *gcp; 364{ 365 register struct vif *vifp; 366 register int s; 367 368 if (gcp->lgc_vifi >= numvifs) 369 return (EINVAL); 370 371 vifp = viftable + gcp->lgc_vifi; 372 if (vifp->v_lcl_addr.s_addr == 0 || (vifp->v_flags & VIFF_TUNNEL)) 373 return (EADDRNOTAVAIL); 374 375 /* If not enough space in existing list, allocate a larger one */ 376 s = splnet(); 377 if (vifp->v_lcl_grps_n + 1 >= vifp->v_lcl_grps_max) { 378 register int num; 379 register struct in_addr *ip; 380 381 num = vifp->v_lcl_grps_max; 382 if (num <= 0) 383 num = 32; /* initial number */ 384 else 385 num += num; /* double last number */ 386 ip = (struct in_addr *)malloc(num * sizeof(*ip), 387 M_MRTABLE, M_NOWAIT); 388 if (ip == NULL) { 389 splx(s); 390 return (ENOBUFS); 391 } 392 393 bzero((caddr_t)ip, num * sizeof(*ip)); /* XXX paranoid */ 394 bcopy((caddr_t)vifp->v_lcl_grps, (caddr_t)ip, 395 vifp->v_lcl_grps_n * sizeof(*ip)); 396 397 vifp->v_lcl_grps_max = num; 398 if (vifp->v_lcl_grps) 399 free(vifp->v_lcl_grps, M_MRTABLE); 400 vifp->v_lcl_grps = ip; 401 402 splx(s); 403 } 404 405 vifp->v_lcl_grps[vifp->v_lcl_grps_n++] = gcp->lgc_gaddr; 406 407 if (gcp->lgc_gaddr.s_addr == vifp->v_cached_group) 408 vifp->v_cached_result = 1; 409 410 splx(s); 411 return (0); 412} 413 414/* 415 * Delete the the local multicast group associated with the vif 416 * indexed by gcp->lgc_vifi. 417 */ 418 419static int 420del_lgrp(gcp) 421 register struct lgrplctl *gcp; 422{ 423 register struct vif *vifp; 424 register int i, error, s; 425 426 if (gcp->lgc_vifi >= numvifs) 427 return (EINVAL); 428 vifp = viftable + gcp->lgc_vifi; 429 if (vifp->v_lcl_addr.s_addr == 0 || (vifp->v_flags & VIFF_TUNNEL)) 430 return (EADDRNOTAVAIL); 431 432 s = splnet(); 433 434 if (gcp->lgc_gaddr.s_addr == vifp->v_cached_group) 435 vifp->v_cached_result = 0; 436 437 error = EADDRNOTAVAIL; 438 for (i = 0; i < vifp->v_lcl_grps_n; ++i) 439 if (same(&gcp->lgc_gaddr, &vifp->v_lcl_grps[i])) { 440 error = 0; 441 vifp->v_lcl_grps_n--; 442 bcopy((caddr_t)&vifp->v_lcl_grps[i + 1], 443 (caddr_t)&vifp->v_lcl_grps[i], 444 (vifp->v_lcl_grps_n - i) * sizeof(struct in_addr)); 445 error = 0; 446 break; 447 } 448 449 splx(s); 450 return (error); 451} 452 453/* 454 * Return 1 if gaddr is a member of the local group list for vifp. 455 */ 456static int 457grplst_member(vifp, gaddr) 458 register struct vif *vifp; 459 struct in_addr gaddr; 460{ 461 register int i, s; 462 register u_long addr; 463 464 mrtstat.mrts_grp_lookups++; 465 466 addr = gaddr.s_addr; 467 if (addr == vifp->v_cached_group) 468 return (vifp->v_cached_result); 469 470 mrtstat.mrts_grp_misses++; 471 472 for (i = 0; i < vifp->v_lcl_grps_n; ++i) 473 if (addr == vifp->v_lcl_grps[i].s_addr) { 474 s = splnet(); 475 vifp->v_cached_group = addr; 476 vifp->v_cached_result = 1; 477 splx(s); 478 return (1); 479 } 480 s = splnet(); 481 vifp->v_cached_group = addr; 482 vifp->v_cached_result = 0; 483 splx(s); 484 return (0); 485} 486 487/* 488 * A simple hash function: returns MRTHASHMOD of the low-order octet of 489 * the argument's network or subnet number. 490 */ 491static u_long 492nethash(in) 493 struct in_addr in; 494{ 495 register u_long n; 496 497 n = in_netof(in); 498 while ((n & 0xff) == 0) 499 n >>= 8; 500 return (MRTHASHMOD(n)); 501} 502 503/* 504 * Add an mrt entry 505 */ 506static int 507add_mrt(mrtcp) 508 register struct mrtctl *mrtcp; 509{ 510 struct mrt *rt; 511 u_long hash; 512 int s; 513 514 if (rt = mrtfind(mrtcp->mrtc_origin)) { 515 /* Just update the route */ 516 s = splnet(); 517 rt->mrt_parent = mrtcp->mrtc_parent; 518 VIFM_COPY(mrtcp->mrtc_children, rt->mrt_children); 519 VIFM_COPY(mrtcp->mrtc_leaves, rt->mrt_leaves); 520 splx(s); 521 return (0); 522 } 523 524 s = splnet(); 525 526 rt = (struct mrt *)malloc(sizeof(*rt), M_MRTABLE, M_NOWAIT); 527 if (rt == NULL) { 528 splx(s); 529 return (ENOBUFS); 530 } 531 532 /* 533 * insert new entry at head of hash chain 534 */ 535 rt->mrt_origin = mrtcp->mrtc_origin; 536 rt->mrt_originmask = mrtcp->mrtc_originmask; 537 rt->mrt_parent = mrtcp->mrtc_parent; 538 VIFM_COPY(mrtcp->mrtc_children, rt->mrt_children); 539 VIFM_COPY(mrtcp->mrtc_leaves, rt->mrt_leaves); 540 /* link into table */ 541 hash = nethash(mrtcp->mrtc_origin); 542 rt->mrt_next = mrttable[hash]; 543 mrttable[hash] = rt; 544 545 splx(s); 546 return (0); 547} 548 549/* 550 * Delete an mrt entry 551 */ 552static int 553del_mrt(origin) 554 register struct in_addr *origin; 555{ 556 register struct mrt *rt, *prev_rt; 557 register u_long hash = nethash(*origin); 558 register int s; 559 560 for (prev_rt = rt = mrttable[hash]; rt; prev_rt = rt, rt = rt->mrt_next) 561 if (origin->s_addr == rt->mrt_origin.s_addr) 562 break; 563 if (!rt) 564 return (ESRCH); 565 566 s = splnet(); 567 568 if (rt == cached_mrt) 569 cached_mrt = NULL; 570 571 if (prev_rt == rt) 572 mrttable[hash] = rt->mrt_next; 573 else 574 prev_rt->mrt_next = rt->mrt_next; 575 free(rt, M_MRTABLE); 576 577 splx(s); 578 return (0); 579} 580 581/* 582 * Find a route for a given origin IP address. 583 */ 584static struct mrt * 585mrtfind(origin) 586 struct in_addr origin; 587{ 588 register struct mrt *rt; 589 register u_int hash; 590 register int s; 591 592 mrtstat.mrts_mrt_lookups++; 593 594 if (cached_mrt != NULL && 595 (origin.s_addr & cached_originmask) == cached_origin) 596 return (cached_mrt); 597 598 mrtstat.mrts_mrt_misses++; 599 600 hash = nethash(origin); 601 for (rt = mrttable[hash]; rt; rt = rt->mrt_next) 602 if ((origin.s_addr & rt->mrt_originmask.s_addr) == 603 rt->mrt_origin.s_addr) { 604 s = splnet(); 605 cached_mrt = rt; 606 cached_origin = rt->mrt_origin.s_addr; 607 cached_originmask = rt->mrt_originmask.s_addr; 608 splx(s); 609 return (rt); 610 } 611 return (NULL); 612} 613 614/* 615 * IP multicast forwarding function. This function assumes that the packet 616 * pointed to by "ip" has arrived on (or is about to be sent to) the interface 617 * pointed to by "ifp", and the packet is to be relayed to other networks 618 * that have members of the packet's destination IP multicast group. 619 * 620 * The packet is returned unscathed to the caller, unless it is tunneled 621 * or erroneous, in which case a non-zero return value tells the caller to 622 * discard it. 623 */ 624 625#define IP_HDR_LEN 20 /* # bytes of fixed IP header (excluding options) */ 626#define TUNNEL_LEN 12 /* # bytes of IP option for tunnel encapsulation */ 627 628int 629ip_mforward(m, ifp) 630 register struct mbuf *m; 631 register struct ifnet *ifp; 632{ 633 register struct ip *ip = mtod(m, struct ip *); 634 register struct mrt *rt; 635 register struct vif *vifp; 636 register int vifi; 637 register u_char *ipoptions; 638 u_long tunnel_src; 639 640 if (ip->ip_hl < (IP_HDR_LEN + TUNNEL_LEN) >> 2 || 641 (ipoptions = (u_char *)(ip + 1))[1] != IPOPT_LSRR ) { 642 /* 643 * Packet arrived via a physical interface. 644 */ 645 tunnel_src = 0; 646 } else { 647 /* 648 * Packet arrived through a tunnel. 649 * 650 * A tunneled packet has a single NOP option and a 651 * two-element loose-source-and-record-route (LSRR) 652 * option immediately following the fixed-size part of 653 * the IP header. At this point in processing, the IP 654 * header should contain the following IP addresses: 655 * 656 * original source - in the source address field 657 * destination group - in the destination address field 658 * remote tunnel end-point - in the first element of LSRR 659 * one of this host's addrs - in the second element of LSRR 660 * 661 * NOTE: RFC-1075 would have the original source and 662 * remote tunnel end-point addresses swapped. However, 663 * that could cause delivery of ICMP error messages to 664 * innocent applications on intermediate routing 665 * hosts! Therefore, we hereby change the spec. 666 */ 667 668 /* 669 * Verify that the tunnel options are well-formed. 670 */ 671 if (ipoptions[0] != IPOPT_NOP || 672 ipoptions[2] != 11 || /* LSRR option length */ 673 ipoptions[3] != 12 || /* LSRR address pointer */ 674 (tunnel_src = *(u_long *)(&ipoptions[4])) == 0) { 675 mrtstat.mrts_bad_tunnel++; 676 return (1); 677 } 678 679 /* 680 * Delete the tunnel options from the packet. 681 */ 682 ovbcopy((caddr_t)(ipoptions + TUNNEL_LEN), (caddr_t)ipoptions, 683 (unsigned)(m->m_len - (IP_HDR_LEN + TUNNEL_LEN))); 684 m->m_len -= TUNNEL_LEN; 685 ip->ip_len -= TUNNEL_LEN; 686 ip->ip_hl -= TUNNEL_LEN >> 2; 687 } 688 689 /* 690 * Don't forward a packet with time-to-live of zero or one, 691 * or a packet destined to a local-only group. 692 */ 693 if (ip->ip_ttl <= 1 || 694 ntohl(ip->ip_dst.s_addr) <= INADDR_MAX_LOCAL_GROUP) 695 return ((int)tunnel_src); 696 697 /* 698 * Don't forward if we don't have a route for the packet's origin. 699 */ 700 if (!(rt = mrtfind(ip->ip_src))) { 701 mrtstat.mrts_no_route++; 702 return ((int)tunnel_src); 703 } 704 705 /* 706 * Don't forward if it didn't arrive from the parent vif for its origin. 707 */ 708 vifi = rt->mrt_parent; 709 if (tunnel_src == 0 ) { 710 if ((viftable[vifi].v_flags & VIFF_TUNNEL) || 711 viftable[vifi].v_ifp != ifp ) 712 return ((int)tunnel_src); 713 } else { 714 if (!(viftable[vifi].v_flags & VIFF_TUNNEL) || 715 viftable[vifi].v_rmt_addr.s_addr != tunnel_src ) 716 return ((int)tunnel_src); 717 } 718 719 /* 720 * For each vif, decide if a copy of the packet should be forwarded. 721 * Forward if: 722 * - the ttl exceeds the vif's threshold AND 723 * - the vif is a child in the origin's route AND 724 * - ( the vif is not a leaf in the origin's route OR 725 * the destination group has members on the vif ) 726 * 727 * (This might be speeded up with some sort of cache -- someday.) 728 */ 729 for (vifp = viftable, vifi = 0; vifi < numvifs; vifp++, vifi++) { 730 if (ip->ip_ttl > vifp->v_threshold && 731 VIFM_ISSET(vifi, rt->mrt_children) && 732 (!VIFM_ISSET(vifi, rt->mrt_leaves) || 733 grplst_member(vifp, ip->ip_dst))) { 734 if (vifp->v_flags & VIFF_TUNNEL) 735 tunnel_send(m, vifp); 736 else 737 phyint_send(m, vifp); 738 } 739 } 740 741 return ((int)tunnel_src); 742} 743 744static void 745phyint_send(m, vifp) 746 register struct mbuf *m; 747 register struct vif *vifp; 748{ 749 register struct ip *ip = mtod(m, struct ip *); 750 register struct mbuf *mb_copy; 751 register struct ip_moptions *imo; 752 register int error; 753 struct ip_moptions simo; 754 755 mb_copy = m_copy(m, 0, M_COPYALL); 756 if (mb_copy == NULL) 757 return; 758 759 imo = &simo; 760 imo->imo_multicast_ifp = vifp->v_ifp; 761 imo->imo_multicast_ttl = ip->ip_ttl - 1; 762 imo->imo_multicast_loop = 1; 763 764 error = ip_output(mb_copy, NULL, NULL, IP_FORWARDING, imo); 765} 766 767static void 768tunnel_send(m, vifp) 769 register struct mbuf *m; 770 register struct vif *vifp; 771{ 772 register struct ip *ip = mtod(m, struct ip *); 773 register struct mbuf *mb_copy, *mb_opts; 774 register struct ip *ip_copy; 775 register int error; 776 register u_char *cp; 777 778 /* 779 * Make sure that adding the tunnel options won't exceed the 780 * maximum allowed number of option bytes. 781 */ 782 if (ip->ip_hl > (60 - TUNNEL_LEN) >> 2) { 783 mrtstat.mrts_cant_tunnel++; 784 return; 785 } 786 787 /* 788 * Get a private copy of the IP header so that changes to some 789 * of the IP fields don't damage the original header, which is 790 * examined later in ip_input.c. 791 */ 792 mb_copy = m_copy(m, IP_HDR_LEN, M_COPYALL); 793 if (mb_copy == NULL) 794 return; 795 MGETHDR(mb_opts, M_DONTWAIT, MT_HEADER); 796 if (mb_opts == NULL) { 797 m_freem(mb_copy); 798 return; 799 } 800 /* 801 * Make mb_opts be the new head of the packet chain. 802 * Any options of the packet were left in the old packet chain head 803 */ 804 mb_opts->m_next = mb_copy; 805 mb_opts->m_len = IP_HDR_LEN + TUNNEL_LEN; 806 mb_opts->m_data += MSIZE - mb_opts->m_len; 807 808 ip_copy = mtod(mb_opts, struct ip *); 809 /* 810 * Copy the base ip header to the new head mbuf. 811 */ 812 *ip_copy = *ip; 813 ip_copy->ip_ttl--; 814 ip_copy->ip_dst = vifp->v_rmt_addr; /* remote tunnel end-point */ 815 /* 816 * Adjust the ip header length to account for the tunnel options. 817 */ 818 ip_copy->ip_hl += TUNNEL_LEN >> 2; 819 ip_copy->ip_len += TUNNEL_LEN; 820 /* 821 * Add the NOP and LSRR after the base ip header 822 */ 823 cp = (u_char *)(ip_copy + 1); 824 *cp++ = IPOPT_NOP; 825 *cp++ = IPOPT_LSRR; 826 *cp++ = 11; /* LSRR option length */ 827 *cp++ = 8; /* LSSR pointer to second element */ 828 *(u_long*)cp = vifp->v_lcl_addr.s_addr; /* local tunnel end-point */ 829 cp += 4; 830 *(u_long*)cp = ip->ip_dst.s_addr; /* destination group */ 831 832 error = ip_output(mb_opts, NULL, NULL, IP_FORWARDING, NULL); 833} 834#endif 835