1 /* 2 * IP multicast routing support for mrouted 3.6/3.8 3 * 4 * (c) 1995 Alan Cox, <alan@redhat.com> 5 * Linux Consultancy and Custom Driver Development 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License 9 * as published by the Free Software Foundation; either version 10 * 2 of the License, or (at your option) any later version. 11 * 12 * Version: $Id: ipmr.c,v 1.65 2001/10/31 21:55:54 davem Exp $ 13 * 14 * Fixes: 15 * Michael Chastain : Incorrect size of copying. 16 * Alan Cox : Added the cache manager code 17 * Alan Cox : Fixed the clone/copy bug and device race. 18 * Mike McLagan : Routing by source 19 * Malcolm Beattie : Buffer handling fixes. 20 * Alexey Kuznetsov : Double buffer free and other fixes. 21 * SVR Anand : Fixed several multicast bugs and problems. 22 * Alexey Kuznetsov : Status, optimisations and more. 23 * Brad Parker : Better behaviour on mrouted upcall 24 * overflow. 25 * Carlos Picoto : PIMv1 Support 26 * Pavlin Ivanov Radoslavov: PIMv2 Registers must checksum only PIM header 27 * Relax this requrement to work with older peers. 28 * 29 */ 30 31 #include <asm/system.h> 32 #include <asm/uaccess.h> 33 #include <linux/types.h> 34 #include <linux/capability.h> 35 #include <linux/errno.h> 36 #include <linux/timer.h> 37 #include <linux/mm.h> 38 #include <linux/kernel.h> 39 #include <linux/fcntl.h> 40 #include <linux/stat.h> 41 #include <linux/socket.h> 42 #include <linux/in.h> 43 #include <linux/inet.h> 44 #include <linux/netdevice.h> 45 #include <linux/inetdevice.h> 46 #include <linux/igmp.h> 47 #include <linux/proc_fs.h> 48 #include <linux/seq_file.h> 49 #include <linux/mroute.h> 50 #include <linux/init.h> 51 #include <linux/if_ether.h> 52 #include <net/net_namespace.h> 53 #include <net/ip.h> 54 #include <net/protocol.h> 55 #include <linux/skbuff.h> 56 #include <net/route.h> 57 #include <net/sock.h> 58 #include <net/icmp.h> 59 #include <net/udp.h> 60 #include <net/raw.h> 61 #include <linux/notifier.h> 62 #include <linux/if_arp.h> 63 #include <linux/netfilter_ipv4.h> 64 #include <net/ipip.h> 65 #include <net/checksum.h> 66 #include <net/netlink.h> 67 68 #if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2) 69 #define CONFIG_IP_PIMSM 1 70 #endif 71 72 static struct sock *mroute_socket; 73 74 75 /* Big lock, protecting vif table, mrt cache and mroute socket state. 76 Note that the changes are semaphored via rtnl_lock. 77 */ 78 79 static DEFINE_RWLOCK(mrt_lock); 80 81 /* 82 * Multicast router control variables 83 */ 84 85 static struct vif_device vif_table[MAXVIFS]; /* Devices */ 86 static int maxvif; 87 88 #define VIF_EXISTS(idx) (vif_table[idx].dev != NULL) 89 90 static int mroute_do_assert; /* Set in PIM assert */ 91 static int mroute_do_pim; 92 93 static struct mfc_cache *mfc_cache_array[MFC_LINES]; /* Forwarding cache */ 94 95 static struct mfc_cache *mfc_unres_queue; /* Queue of unresolved entries */ 96 static atomic_t cache_resolve_queue_len; /* Size of unresolved */ 97 98 /* Special spinlock for queue of unresolved entries */ 99 static DEFINE_SPINLOCK(mfc_unres_lock); 100 101 /* We return to original Alan's scheme. Hash table of resolved 102 entries is changed only in process context and protected 103 with weak lock mrt_lock. Queue of unresolved entries is protected 104 with strong spinlock mfc_unres_lock. 105 106 In this case data path is free of exclusive locks at all. 107 */ 108 109 static struct kmem_cache *mrt_cachep __read_mostly; 110 111 static int ip_mr_forward(struct sk_buff *skb, struct mfc_cache *cache, int local); 112 static int ipmr_cache_report(struct sk_buff *pkt, vifi_t vifi, int assert); 113 static int ipmr_fill_mroute(struct sk_buff *skb, struct mfc_cache *c, struct rtmsg *rtm); 114 115 #ifdef CONFIG_IP_PIMSM_V2 116 static struct net_protocol pim_protocol; 117 #endif 118 119 static struct timer_list ipmr_expire_timer; 120 121 /* Service routines creating virtual interfaces: DVMRP tunnels and PIMREG */ 122 123 static 124 struct net_device *ipmr_new_tunnel(struct vifctl *v) 125 { 126 struct net_device *dev; 127 128 dev = __dev_get_by_name(&init_net, "tunl0"); 129 130 if (dev) { 131 int err; 132 struct ifreq ifr; 133 mm_segment_t oldfs; 134 struct ip_tunnel_parm p; 135 struct in_device *in_dev; 136 137 memset(&p, 0, sizeof(p)); 138 p.iph.daddr = v->vifc_rmt_addr.s_addr; 139 p.iph.saddr = v->vifc_lcl_addr.s_addr; 140 p.iph.version = 4; 141 p.iph.ihl = 5; 142 p.iph.protocol = IPPROTO_IPIP; 143 sprintf(p.name, "dvmrp%d", v->vifc_vifi); 144 ifr.ifr_ifru.ifru_data = (void*)&p; 145 146 oldfs = get_fs(); set_fs(KERNEL_DS); 147 err = dev->do_ioctl(dev, &ifr, SIOCADDTUNNEL); 148 set_fs(oldfs); 149 150 dev = NULL; 151 152 if (err == 0 && (dev = __dev_get_by_name(&init_net, p.name)) != NULL) { 153 dev->flags |= IFF_MULTICAST; 154 155 in_dev = __in_dev_get_rtnl(dev); 156 if (in_dev == NULL) 157 goto failure; 158 159 ipv4_devconf_setall(in_dev); 160 IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0; 161 162 if (dev_open(dev)) 163 goto failure; 164 } 165 } 166 return dev; 167 168 failure: 169 /* allow the register to be completed before unregistering. */ 170 rtnl_unlock(); 171 rtnl_lock(); 172 173 unregister_netdevice(dev); 174 return NULL; 175 } 176 177 #ifdef CONFIG_IP_PIMSM 178 179 static int reg_vif_num = -1; 180 181 static int reg_vif_xmit(struct sk_buff *skb, struct net_device *dev) 182 { 183 read_lock(&mrt_lock); 184 ((struct net_device_stats*)netdev_priv(dev))->tx_bytes += skb->len; 185 ((struct net_device_stats*)netdev_priv(dev))->tx_packets++; 186 ipmr_cache_report(skb, reg_vif_num, IGMPMSG_WHOLEPKT); 187 read_unlock(&mrt_lock); 188 kfree_skb(skb); 189 return 0; 190 } 191 192 static struct net_device_stats *reg_vif_get_stats(struct net_device *dev) 193 { 194 return (struct net_device_stats*)netdev_priv(dev); 195 } 196 197 static void reg_vif_setup(struct net_device *dev) 198 { 199 dev->type = ARPHRD_PIMREG; 200 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr) - 8; 201 dev->flags = IFF_NOARP; 202 dev->hard_start_xmit = reg_vif_xmit; 203 dev->get_stats = reg_vif_get_stats; 204 dev->destructor = free_netdev; 205 } 206 207 static struct net_device *ipmr_reg_vif(void) 208 { 209 struct net_device *dev; 210 struct in_device *in_dev; 211 212 dev = alloc_netdev(sizeof(struct net_device_stats), "pimreg", 213 reg_vif_setup); 214 215 if (dev == NULL) 216 return NULL; 217 218 if (register_netdevice(dev)) { 219 free_netdev(dev); 220 return NULL; 221 } 222 dev->iflink = 0; 223 224 rcu_read_lock(); 225 if ((in_dev = __in_dev_get_rcu(dev)) == NULL) { 226 rcu_read_unlock(); 227 goto failure; 228 } 229 230 ipv4_devconf_setall(in_dev); 231 IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0; 232 rcu_read_unlock(); 233 234 if (dev_open(dev)) 235 goto failure; 236 237 return dev; 238 239 failure: 240 /* allow the register to be completed before unregistering. */ 241 rtnl_unlock(); 242 rtnl_lock(); 243 244 unregister_netdevice(dev); 245 return NULL; 246 } 247 #endif 248 249 /* 250 * Delete a VIF entry 251 */ 252 253 static int vif_delete(int vifi) 254 { 255 struct vif_device *v; 256 struct net_device *dev; 257 struct in_device *in_dev; 258 259 if (vifi < 0 || vifi >= maxvif) 260 return -EADDRNOTAVAIL; 261 262 v = &vif_table[vifi]; 263 264 write_lock_bh(&mrt_lock); 265 dev = v->dev; 266 v->dev = NULL; 267 268 if (!dev) { 269 write_unlock_bh(&mrt_lock); 270 return -EADDRNOTAVAIL; 271 } 272 273 #ifdef CONFIG_IP_PIMSM 274 if (vifi == reg_vif_num) 275 reg_vif_num = -1; 276 #endif 277 278 if (vifi+1 == maxvif) { 279 int tmp; 280 for (tmp=vifi-1; tmp>=0; tmp--) { 281 if (VIF_EXISTS(tmp)) 282 break; 283 } 284 maxvif = tmp+1; 285 } 286 287 write_unlock_bh(&mrt_lock); 288 289 dev_set_allmulti(dev, -1); 290 291 if ((in_dev = __in_dev_get_rtnl(dev)) != NULL) { 292 IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)--; 293 ip_rt_multicast_event(in_dev); 294 } 295 296 if (v->flags&(VIFF_TUNNEL|VIFF_REGISTER)) 297 unregister_netdevice(dev); 298 299 dev_put(dev); 300 return 0; 301 } 302 303 /* Destroy an unresolved cache entry, killing queued skbs 304 and reporting error to netlink readers. 305 */ 306 307 static void ipmr_destroy_unres(struct mfc_cache *c) 308 { 309 struct sk_buff *skb; 310 struct nlmsgerr *e; 311 312 atomic_dec(&cache_resolve_queue_len); 313 314 while ((skb=skb_dequeue(&c->mfc_un.unres.unresolved))) { 315 if (ip_hdr(skb)->version == 0) { 316 struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr)); 317 nlh->nlmsg_type = NLMSG_ERROR; 318 nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct nlmsgerr)); 319 skb_trim(skb, nlh->nlmsg_len); 320 e = NLMSG_DATA(nlh); 321 e->error = -ETIMEDOUT; 322 memset(&e->msg, 0, sizeof(e->msg)); 323 324 rtnl_unicast(skb, NETLINK_CB(skb).pid); 325 } else 326 kfree_skb(skb); 327 } 328 329 kmem_cache_free(mrt_cachep, c); 330 } 331 332 333 /* Single timer process for all the unresolved queue. */ 334 335 static void ipmr_expire_process(unsigned long dummy) 336 { 337 unsigned long now; 338 unsigned long expires; 339 struct mfc_cache *c, **cp; 340 341 if (!spin_trylock(&mfc_unres_lock)) { 342 mod_timer(&ipmr_expire_timer, jiffies+HZ/10); 343 return; 344 } 345 346 if (atomic_read(&cache_resolve_queue_len) == 0) 347 goto out; 348 349 now = jiffies; 350 expires = 10*HZ; 351 cp = &mfc_unres_queue; 352 353 while ((c=*cp) != NULL) { 354 if (time_after(c->mfc_un.unres.expires, now)) { 355 unsigned long interval = c->mfc_un.unres.expires - now; 356 if (interval < expires) 357 expires = interval; 358 cp = &c->next; 359 continue; 360 } 361 362 *cp = c->next; 363 364 ipmr_destroy_unres(c); 365 } 366 367 if (atomic_read(&cache_resolve_queue_len)) 368 mod_timer(&ipmr_expire_timer, jiffies + expires); 369 370 out: 371 spin_unlock(&mfc_unres_lock); 372 } 373 374 /* Fill oifs list. It is called under write locked mrt_lock. */ 375 376 static void ipmr_update_thresholds(struct mfc_cache *cache, unsigned char *ttls) 377 { 378 int vifi; 379 380 cache->mfc_un.res.minvif = MAXVIFS; 381 cache->mfc_un.res.maxvif = 0; 382 memset(cache->mfc_un.res.ttls, 255, MAXVIFS); 383 384 for (vifi=0; vifi<maxvif; vifi++) { 385 if (VIF_EXISTS(vifi) && ttls[vifi] && ttls[vifi] < 255) { 386 cache->mfc_un.res.ttls[vifi] = ttls[vifi]; 387 if (cache->mfc_un.res.minvif > vifi) 388 cache->mfc_un.res.minvif = vifi; 389 if (cache->mfc_un.res.maxvif <= vifi) 390 cache->mfc_un.res.maxvif = vifi + 1; 391 } 392 } 393 } 394 395 static int vif_add(struct vifctl *vifc, int mrtsock) 396 { 397 int vifi = vifc->vifc_vifi; 398 struct vif_device *v = &vif_table[vifi]; 399 struct net_device *dev; 400 struct in_device *in_dev; 401 402 /* Is vif busy ? */ 403 if (VIF_EXISTS(vifi)) 404 return -EADDRINUSE; 405 406 switch (vifc->vifc_flags) { 407 #ifdef CONFIG_IP_PIMSM 408 case VIFF_REGISTER: 409 /* 410 * Special Purpose VIF in PIM 411 * All the packets will be sent to the daemon 412 */ 413 if (reg_vif_num >= 0) 414 return -EADDRINUSE; 415 dev = ipmr_reg_vif(); 416 if (!dev) 417 return -ENOBUFS; 418 break; 419 #endif 420 case VIFF_TUNNEL: 421 dev = ipmr_new_tunnel(vifc); 422 if (!dev) 423 return -ENOBUFS; 424 break; 425 case 0: 426 dev = ip_dev_find(vifc->vifc_lcl_addr.s_addr); 427 if (!dev) 428 return -EADDRNOTAVAIL; 429 dev_put(dev); 430 break; 431 default: 432 return -EINVAL; 433 } 434 435 if ((in_dev = __in_dev_get_rtnl(dev)) == NULL) 436 return -EADDRNOTAVAIL; 437 IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)++; 438 dev_set_allmulti(dev, +1); 439 ip_rt_multicast_event(in_dev); 440 441 /* 442 * Fill in the VIF structures 443 */ 444 v->rate_limit=vifc->vifc_rate_limit; 445 v->local=vifc->vifc_lcl_addr.s_addr; 446 v->remote=vifc->vifc_rmt_addr.s_addr; 447 v->flags=vifc->vifc_flags; 448 if (!mrtsock) 449 v->flags |= VIFF_STATIC; 450 v->threshold=vifc->vifc_threshold; 451 v->bytes_in = 0; 452 v->bytes_out = 0; 453 v->pkt_in = 0; 454 v->pkt_out = 0; 455 v->link = dev->ifindex; 456 if (v->flags&(VIFF_TUNNEL|VIFF_REGISTER)) 457 v->link = dev->iflink; 458 459 /* And finish update writing critical data */ 460 write_lock_bh(&mrt_lock); 461 dev_hold(dev); 462 v->dev=dev; 463 #ifdef CONFIG_IP_PIMSM 464 if (v->flags&VIFF_REGISTER) 465 reg_vif_num = vifi; 466 #endif 467 if (vifi+1 > maxvif) 468 maxvif = vifi+1; 469 write_unlock_bh(&mrt_lock); 470 return 0; 471 } 472 473 static struct mfc_cache *ipmr_cache_find(__be32 origin, __be32 mcastgrp) 474 { 475 int line=MFC_HASH(mcastgrp,origin); 476 struct mfc_cache *c; 477 478 for (c=mfc_cache_array[line]; c; c = c->next) { 479 if (c->mfc_origin==origin && c->mfc_mcastgrp==mcastgrp) 480 break; 481 } 482 return c; 483 } 484 485 /* 486 * Allocate a multicast cache entry 487 */ 488 static struct mfc_cache *ipmr_cache_alloc(void) 489 { 490 struct mfc_cache *c=kmem_cache_zalloc(mrt_cachep, GFP_KERNEL); 491 if (c==NULL) 492 return NULL; 493 c->mfc_un.res.minvif = MAXVIFS; 494 return c; 495 } 496 497 static struct mfc_cache *ipmr_cache_alloc_unres(void) 498 { 499 struct mfc_cache *c=kmem_cache_zalloc(mrt_cachep, GFP_ATOMIC); 500 if (c==NULL) 501 return NULL; 502 skb_queue_head_init(&c->mfc_un.unres.unresolved); 503 c->mfc_un.unres.expires = jiffies + 10*HZ; 504 return c; 505 } 506 507 /* 508 * A cache entry has gone into a resolved state from queued 509 */ 510 511 static void ipmr_cache_resolve(struct mfc_cache *uc, struct mfc_cache *c) 512 { 513 struct sk_buff *skb; 514 struct nlmsgerr *e; 515 516 /* 517 * Play the pending entries through our router 518 */ 519 520 while ((skb=__skb_dequeue(&uc->mfc_un.unres.unresolved))) { 521 if (ip_hdr(skb)->version == 0) { 522 struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr)); 523 524 if (ipmr_fill_mroute(skb, c, NLMSG_DATA(nlh)) > 0) { 525 nlh->nlmsg_len = (skb_tail_pointer(skb) - 526 (u8 *)nlh); 527 } else { 528 nlh->nlmsg_type = NLMSG_ERROR; 529 nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct nlmsgerr)); 530 skb_trim(skb, nlh->nlmsg_len); 531 e = NLMSG_DATA(nlh); 532 e->error = -EMSGSIZE; 533 memset(&e->msg, 0, sizeof(e->msg)); 534 } 535 536 rtnl_unicast(skb, NETLINK_CB(skb).pid); 537 } else 538 ip_mr_forward(skb, c, 0); 539 } 540 } 541 542 /* 543 * Bounce a cache query up to mrouted. We could use netlink for this but mrouted 544 * expects the following bizarre scheme. 545 * 546 * Called under mrt_lock. 547 */ 548 549 static int ipmr_cache_report(struct sk_buff *pkt, vifi_t vifi, int assert) 550 { 551 struct sk_buff *skb; 552 const int ihl = ip_hdrlen(pkt); 553 struct igmphdr *igmp; 554 struct igmpmsg *msg; 555 int ret; 556 557 #ifdef CONFIG_IP_PIMSM 558 if (assert == IGMPMSG_WHOLEPKT) 559 skb = skb_realloc_headroom(pkt, sizeof(struct iphdr)); 560 else 561 #endif 562 skb = alloc_skb(128, GFP_ATOMIC); 563 564 if (!skb) 565 return -ENOBUFS; 566 567 #ifdef CONFIG_IP_PIMSM 568 if (assert == IGMPMSG_WHOLEPKT) { 569 /* Ugly, but we have no choice with this interface. 570 Duplicate old header, fix ihl, length etc. 571 And all this only to mangle msg->im_msgtype and 572 to set msg->im_mbz to "mbz" :-) 573 */ 574 skb_push(skb, sizeof(struct iphdr)); 575 skb_reset_network_header(skb); 576 skb_reset_transport_header(skb); 577 msg = (struct igmpmsg *)skb_network_header(skb); 578 memcpy(msg, skb_network_header(pkt), sizeof(struct iphdr)); 579 msg->im_msgtype = IGMPMSG_WHOLEPKT; 580 msg->im_mbz = 0; 581 msg->im_vif = reg_vif_num; 582 ip_hdr(skb)->ihl = sizeof(struct iphdr) >> 2; 583 ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(pkt)->tot_len) + 584 sizeof(struct iphdr)); 585 } else 586 #endif 587 { 588 589 /* 590 * Copy the IP header 591 */ 592 593 skb->network_header = skb->tail; 594 skb_put(skb, ihl); 595 skb_copy_to_linear_data(skb, pkt->data, ihl); 596 ip_hdr(skb)->protocol = 0; /* Flag to the kernel this is a route add */ 597 msg = (struct igmpmsg *)skb_network_header(skb); 598 msg->im_vif = vifi; 599 skb->dst = dst_clone(pkt->dst); 600 601 /* 602 * Add our header 603 */ 604 605 igmp=(struct igmphdr *)skb_put(skb,sizeof(struct igmphdr)); 606 igmp->type = 607 msg->im_msgtype = assert; 608 igmp->code = 0; 609 ip_hdr(skb)->tot_len = htons(skb->len); /* Fix the length */ 610 skb->transport_header = skb->network_header; 611 } 612 613 if (mroute_socket == NULL) { 614 kfree_skb(skb); 615 return -EINVAL; 616 } 617 618 /* 619 * Deliver to mrouted 620 */ 621 if ((ret=sock_queue_rcv_skb(mroute_socket,skb))<0) { 622 if (net_ratelimit()) 623 printk(KERN_WARNING "mroute: pending queue full, dropping entries.\n"); 624 kfree_skb(skb); 625 } 626 627 return ret; 628 } 629 630 /* 631 * Queue a packet for resolution. It gets locked cache entry! 632 */ 633 634 static int 635 ipmr_cache_unresolved(vifi_t vifi, struct sk_buff *skb) 636 { 637 int err; 638 struct mfc_cache *c; 639 const struct iphdr *iph = ip_hdr(skb); 640 641 spin_lock_bh(&mfc_unres_lock); 642 for (c=mfc_unres_queue; c; c=c->next) { 643 if (c->mfc_mcastgrp == iph->daddr && 644 c->mfc_origin == iph->saddr) 645 break; 646 } 647 648 if (c == NULL) { 649 /* 650 * Create a new entry if allowable 651 */ 652 653 if (atomic_read(&cache_resolve_queue_len)>=10 || 654 (c=ipmr_cache_alloc_unres())==NULL) { 655 spin_unlock_bh(&mfc_unres_lock); 656 657 kfree_skb(skb); 658 return -ENOBUFS; 659 } 660 661 /* 662 * Fill in the new cache entry 663 */ 664 c->mfc_parent = -1; 665 c->mfc_origin = iph->saddr; 666 c->mfc_mcastgrp = iph->daddr; 667 668 /* 669 * Reflect first query at mrouted. 670 */ 671 if ((err = ipmr_cache_report(skb, vifi, IGMPMSG_NOCACHE))<0) { 672 /* If the report failed throw the cache entry 673 out - Brad Parker 674 */ 675 spin_unlock_bh(&mfc_unres_lock); 676 677 kmem_cache_free(mrt_cachep, c); 678 kfree_skb(skb); 679 return err; 680 } 681 682 atomic_inc(&cache_resolve_queue_len); 683 c->next = mfc_unres_queue; 684 mfc_unres_queue = c; 685 686 mod_timer(&ipmr_expire_timer, c->mfc_un.unres.expires); 687 } 688 689 /* 690 * See if we can append the packet 691 */ 692 if (c->mfc_un.unres.unresolved.qlen>3) { 693 kfree_skb(skb); 694 err = -ENOBUFS; 695 } else { 696 skb_queue_tail(&c->mfc_un.unres.unresolved,skb); 697 err = 0; 698 } 699 700 spin_unlock_bh(&mfc_unres_lock); 701 return err; 702 } 703 704 /* 705 * MFC cache manipulation by user space mroute daemon 706 */ 707 708 static int ipmr_mfc_delete(struct mfcctl *mfc) 709 { 710 int line; 711 struct mfc_cache *c, **cp; 712 713 line=MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr); 714 715 for (cp=&mfc_cache_array[line]; (c=*cp) != NULL; cp = &c->next) { 716 if (c->mfc_origin == mfc->mfcc_origin.s_addr && 717 c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr) { 718 write_lock_bh(&mrt_lock); 719 *cp = c->next; 720 write_unlock_bh(&mrt_lock); 721 722 kmem_cache_free(mrt_cachep, c); 723 return 0; 724 } 725 } 726 return -ENOENT; 727 } 728 729 static int ipmr_mfc_add(struct mfcctl *mfc, int mrtsock) 730 { 731 int line; 732 struct mfc_cache *uc, *c, **cp; 733 734 line=MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr); 735 736 for (cp=&mfc_cache_array[line]; (c=*cp) != NULL; cp = &c->next) { 737 if (c->mfc_origin == mfc->mfcc_origin.s_addr && 738 c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr) 739 break; 740 } 741 742 if (c != NULL) { 743 write_lock_bh(&mrt_lock); 744 c->mfc_parent = mfc->mfcc_parent; 745 ipmr_update_thresholds(c, mfc->mfcc_ttls); 746 if (!mrtsock) 747 c->mfc_flags |= MFC_STATIC; 748 write_unlock_bh(&mrt_lock); 749 return 0; 750 } 751 752 if (!MULTICAST(mfc->mfcc_mcastgrp.s_addr)) 753 return -EINVAL; 754 755 c=ipmr_cache_alloc(); 756 if (c==NULL) 757 return -ENOMEM; 758 759 c->mfc_origin=mfc->mfcc_origin.s_addr; 760 c->mfc_mcastgrp=mfc->mfcc_mcastgrp.s_addr; 761 c->mfc_parent=mfc->mfcc_parent; 762 ipmr_update_thresholds(c, mfc->mfcc_ttls); 763 if (!mrtsock) 764 c->mfc_flags |= MFC_STATIC; 765 766 write_lock_bh(&mrt_lock); 767 c->next = mfc_cache_array[line]; 768 mfc_cache_array[line] = c; 769 write_unlock_bh(&mrt_lock); 770 771 /* 772 * Check to see if we resolved a queued list. If so we 773 * need to send on the frames and tidy up. 774 */ 775 spin_lock_bh(&mfc_unres_lock); 776 for (cp = &mfc_unres_queue; (uc=*cp) != NULL; 777 cp = &uc->next) { 778 if (uc->mfc_origin == c->mfc_origin && 779 uc->mfc_mcastgrp == c->mfc_mcastgrp) { 780 *cp = uc->next; 781 if (atomic_dec_and_test(&cache_resolve_queue_len)) 782 del_timer(&ipmr_expire_timer); 783 break; 784 } 785 } 786 spin_unlock_bh(&mfc_unres_lock); 787 788 if (uc) { 789 ipmr_cache_resolve(uc, c); 790 kmem_cache_free(mrt_cachep, uc); 791 } 792 return 0; 793 } 794 795 /* 796 * Close the multicast socket, and clear the vif tables etc 797 */ 798 799 static void mroute_clean_tables(struct sock *sk) 800 { 801 int i; 802 803 /* 804 * Shut down all active vif entries 805 */ 806 for (i=0; i<maxvif; i++) { 807 if (!(vif_table[i].flags&VIFF_STATIC)) 808 vif_delete(i); 809 } 810 811 /* 812 * Wipe the cache 813 */ 814 for (i=0;i<MFC_LINES;i++) { 815 struct mfc_cache *c, **cp; 816 817 cp = &mfc_cache_array[i]; 818 while ((c = *cp) != NULL) { 819 if (c->mfc_flags&MFC_STATIC) { 820 cp = &c->next; 821 continue; 822 } 823 write_lock_bh(&mrt_lock); 824 *cp = c->next; 825 write_unlock_bh(&mrt_lock); 826 827 kmem_cache_free(mrt_cachep, c); 828 } 829 } 830 831 if (atomic_read(&cache_resolve_queue_len) != 0) { 832 struct mfc_cache *c; 833 834 spin_lock_bh(&mfc_unres_lock); 835 while (mfc_unres_queue != NULL) { 836 c = mfc_unres_queue; 837 mfc_unres_queue = c->next; 838 spin_unlock_bh(&mfc_unres_lock); 839 840 ipmr_destroy_unres(c); 841 842 spin_lock_bh(&mfc_unres_lock); 843 } 844 spin_unlock_bh(&mfc_unres_lock); 845 } 846 } 847 848 static void mrtsock_destruct(struct sock *sk) 849 { 850 rtnl_lock(); 851 if (sk == mroute_socket) { 852 IPV4_DEVCONF_ALL(MC_FORWARDING)--; 853 854 write_lock_bh(&mrt_lock); 855 mroute_socket=NULL; 856 write_unlock_bh(&mrt_lock); 857 858 mroute_clean_tables(sk); 859 } 860 rtnl_unlock(); 861 } 862 863 /* 864 * Socket options and virtual interface manipulation. The whole 865 * virtual interface system is a complete heap, but unfortunately 866 * that's how BSD mrouted happens to think. Maybe one day with a proper 867 * MOSPF/PIM router set up we can clean this up. 868 */ 869 870 int ip_mroute_setsockopt(struct sock *sk,int optname,char __user *optval,int optlen) 871 { 872 int ret; 873 struct vifctl vif; 874 struct mfcctl mfc; 875 876 if (optname != MRT_INIT) { 877 if (sk != mroute_socket && !capable(CAP_NET_ADMIN)) 878 return -EACCES; 879 } 880 881 switch (optname) { 882 case MRT_INIT: 883 if (sk->sk_type != SOCK_RAW || 884 inet_sk(sk)->num != IPPROTO_IGMP) 885 return -EOPNOTSUPP; 886 if (optlen!=sizeof(int)) 887 return -ENOPROTOOPT; 888 889 rtnl_lock(); 890 if (mroute_socket) { 891 rtnl_unlock(); 892 return -EADDRINUSE; 893 } 894 895 ret = ip_ra_control(sk, 1, mrtsock_destruct); 896 if (ret == 0) { 897 write_lock_bh(&mrt_lock); 898 mroute_socket=sk; 899 write_unlock_bh(&mrt_lock); 900 901 IPV4_DEVCONF_ALL(MC_FORWARDING)++; 902 } 903 rtnl_unlock(); 904 return ret; 905 case MRT_DONE: 906 if (sk!=mroute_socket) 907 return -EACCES; 908 return ip_ra_control(sk, 0, NULL); 909 case MRT_ADD_VIF: 910 case MRT_DEL_VIF: 911 if (optlen!=sizeof(vif)) 912 return -EINVAL; 913 if (copy_from_user(&vif,optval,sizeof(vif))) 914 return -EFAULT; 915 if (vif.vifc_vifi >= MAXVIFS) 916 return -ENFILE; 917 rtnl_lock(); 918 if (optname==MRT_ADD_VIF) { 919 ret = vif_add(&vif, sk==mroute_socket); 920 } else { 921 ret = vif_delete(vif.vifc_vifi); 922 } 923 rtnl_unlock(); 924 return ret; 925 926 /* 927 * Manipulate the forwarding caches. These live 928 * in a sort of kernel/user symbiosis. 929 */ 930 case MRT_ADD_MFC: 931 case MRT_DEL_MFC: 932 if (optlen!=sizeof(mfc)) 933 return -EINVAL; 934 if (copy_from_user(&mfc,optval, sizeof(mfc))) 935 return -EFAULT; 936 rtnl_lock(); 937 if (optname==MRT_DEL_MFC) 938 ret = ipmr_mfc_delete(&mfc); 939 else 940 ret = ipmr_mfc_add(&mfc, sk==mroute_socket); 941 rtnl_unlock(); 942 return ret; 943 /* 944 * Control PIM assert. 945 */ 946 case MRT_ASSERT: 947 { 948 int v; 949 if (get_user(v,(int __user *)optval)) 950 return -EFAULT; 951 mroute_do_assert=(v)?1:0; 952 return 0; 953 } 954 #ifdef CONFIG_IP_PIMSM 955 case MRT_PIM: 956 { 957 int v, ret; 958 if (get_user(v,(int __user *)optval)) 959 return -EFAULT; 960 v = (v)?1:0; 961 rtnl_lock(); 962 ret = 0; 963 if (v != mroute_do_pim) { 964 mroute_do_pim = v; 965 mroute_do_assert = v; 966 #ifdef CONFIG_IP_PIMSM_V2 967 if (mroute_do_pim) 968 ret = inet_add_protocol(&pim_protocol, 969 IPPROTO_PIM); 970 else 971 ret = inet_del_protocol(&pim_protocol, 972 IPPROTO_PIM); 973 if (ret < 0) 974 ret = -EAGAIN; 975 #endif 976 } 977 rtnl_unlock(); 978 return ret; 979 } 980 #endif 981 /* 982 * Spurious command, or MRT_VERSION which you cannot 983 * set. 984 */ 985 default: 986 return -ENOPROTOOPT; 987 } 988 } 989 990 /* 991 * Getsock opt support for the multicast routing system. 992 */ 993 994 int ip_mroute_getsockopt(struct sock *sk,int optname,char __user *optval,int __user *optlen) 995 { 996 int olr; 997 int val; 998 999 if (optname!=MRT_VERSION && 1000 #ifdef CONFIG_IP_PIMSM 1001 optname!=MRT_PIM && 1002 #endif 1003 optname!=MRT_ASSERT) 1004 return -ENOPROTOOPT; 1005 1006 if (get_user(olr, optlen)) 1007 return -EFAULT; 1008 1009 olr = min_t(unsigned int, olr, sizeof(int)); 1010 if (olr < 0) 1011 return -EINVAL; 1012 1013 if (put_user(olr,optlen)) 1014 return -EFAULT; 1015 if (optname==MRT_VERSION) 1016 val=0x0305; 1017 #ifdef CONFIG_IP_PIMSM 1018 else if (optname==MRT_PIM) 1019 val=mroute_do_pim; 1020 #endif 1021 else 1022 val=mroute_do_assert; 1023 if (copy_to_user(optval,&val,olr)) 1024 return -EFAULT; 1025 return 0; 1026 } 1027 1028 /* 1029 * The IP multicast ioctl support routines. 1030 */ 1031 1032 int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg) 1033 { 1034 struct sioc_sg_req sr; 1035 struct sioc_vif_req vr; 1036 struct vif_device *vif; 1037 struct mfc_cache *c; 1038 1039 switch (cmd) { 1040 case SIOCGETVIFCNT: 1041 if (copy_from_user(&vr,arg,sizeof(vr))) 1042 return -EFAULT; 1043 if (vr.vifi>=maxvif) 1044 return -EINVAL; 1045 read_lock(&mrt_lock); 1046 vif=&vif_table[vr.vifi]; 1047 if (VIF_EXISTS(vr.vifi)) { 1048 vr.icount=vif->pkt_in; 1049 vr.ocount=vif->pkt_out; 1050 vr.ibytes=vif->bytes_in; 1051 vr.obytes=vif->bytes_out; 1052 read_unlock(&mrt_lock); 1053 1054 if (copy_to_user(arg,&vr,sizeof(vr))) 1055 return -EFAULT; 1056 return 0; 1057 } 1058 read_unlock(&mrt_lock); 1059 return -EADDRNOTAVAIL; 1060 case SIOCGETSGCNT: 1061 if (copy_from_user(&sr,arg,sizeof(sr))) 1062 return -EFAULT; 1063 1064 read_lock(&mrt_lock); 1065 c = ipmr_cache_find(sr.src.s_addr, sr.grp.s_addr); 1066 if (c) { 1067 sr.pktcnt = c->mfc_un.res.pkt; 1068 sr.bytecnt = c->mfc_un.res.bytes; 1069 sr.wrong_if = c->mfc_un.res.wrong_if; 1070 read_unlock(&mrt_lock); 1071 1072 if (copy_to_user(arg,&sr,sizeof(sr))) 1073 return -EFAULT; 1074 return 0; 1075 } 1076 read_unlock(&mrt_lock); 1077 return -EADDRNOTAVAIL; 1078 default: 1079 return -ENOIOCTLCMD; 1080 } 1081 } 1082 1083 1084 static int ipmr_device_event(struct notifier_block *this, unsigned long event, void *ptr) 1085 { 1086 struct net_device *dev = ptr; 1087 struct vif_device *v; 1088 int ct; 1089 1090 if (dev->nd_net != &init_net) 1091 return NOTIFY_DONE; 1092 1093 if (event != NETDEV_UNREGISTER) 1094 return NOTIFY_DONE; 1095 v=&vif_table[0]; 1096 for (ct=0;ct<maxvif;ct++,v++) { 1097 if (v->dev==dev) 1098 vif_delete(ct); 1099 } 1100 return NOTIFY_DONE; 1101 } 1102 1103 1104 static struct notifier_block ip_mr_notifier={ 1105 .notifier_call = ipmr_device_event, 1106 }; 1107 1108 /* 1109 * Encapsulate a packet by attaching a valid IPIP header to it. 1110 * This avoids tunnel drivers and other mess and gives us the speed so 1111 * important for multicast video. 1112 */ 1113 1114 static void ip_encap(struct sk_buff *skb, __be32 saddr, __be32 daddr) 1115 { 1116 struct iphdr *iph; 1117 struct iphdr *old_iph = ip_hdr(skb); 1118 1119 skb_push(skb, sizeof(struct iphdr)); 1120 skb->transport_header = skb->network_header; 1121 skb_reset_network_header(skb); 1122 iph = ip_hdr(skb); 1123 1124 iph->version = 4; 1125 iph->tos = old_iph->tos; 1126 iph->ttl = old_iph->ttl; 1127 iph->frag_off = 0; 1128 iph->daddr = daddr; 1129 iph->saddr = saddr; 1130 iph->protocol = IPPROTO_IPIP; 1131 iph->ihl = 5; 1132 iph->tot_len = htons(skb->len); 1133 ip_select_ident(iph, skb->dst, NULL); 1134 ip_send_check(iph); 1135 1136 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); 1137 nf_reset(skb); 1138 } 1139 1140 static inline int ipmr_forward_finish(struct sk_buff *skb) 1141 { 1142 struct ip_options * opt = &(IPCB(skb)->opt); 1143 1144 IP_INC_STATS_BH(IPSTATS_MIB_OUTFORWDATAGRAMS); 1145 1146 if (unlikely(opt->optlen)) 1147 ip_forward_options(skb); 1148 1149 return dst_output(skb); 1150 } 1151 1152 /* 1153 * Processing handlers for ipmr_forward 1154 */ 1155 1156 static void ipmr_queue_xmit(struct sk_buff *skb, struct mfc_cache *c, int vifi) 1157 { 1158 const struct iphdr *iph = ip_hdr(skb); 1159 struct vif_device *vif = &vif_table[vifi]; 1160 struct net_device *dev; 1161 struct rtable *rt; 1162 int encap = 0; 1163 1164 if (vif->dev == NULL) 1165 goto out_free; 1166 1167 #ifdef CONFIG_IP_PIMSM 1168 if (vif->flags & VIFF_REGISTER) { 1169 vif->pkt_out++; 1170 vif->bytes_out+=skb->len; 1171 ((struct net_device_stats*)netdev_priv(vif->dev))->tx_bytes += skb->len; 1172 ((struct net_device_stats*)netdev_priv(vif->dev))->tx_packets++; 1173 ipmr_cache_report(skb, vifi, IGMPMSG_WHOLEPKT); 1174 kfree_skb(skb); 1175 return; 1176 } 1177 #endif 1178 1179 if (vif->flags&VIFF_TUNNEL) { 1180 struct flowi fl = { .oif = vif->link, 1181 .nl_u = { .ip4_u = 1182 { .daddr = vif->remote, 1183 .saddr = vif->local, 1184 .tos = RT_TOS(iph->tos) } }, 1185 .proto = IPPROTO_IPIP }; 1186 if (ip_route_output_key(&rt, &fl)) 1187 goto out_free; 1188 encap = sizeof(struct iphdr); 1189 } else { 1190 struct flowi fl = { .oif = vif->link, 1191 .nl_u = { .ip4_u = 1192 { .daddr = iph->daddr, 1193 .tos = RT_TOS(iph->tos) } }, 1194 .proto = IPPROTO_IPIP }; 1195 if (ip_route_output_key(&rt, &fl)) 1196 goto out_free; 1197 } 1198 1199 dev = rt->u.dst.dev; 1200 1201 if (skb->len+encap > dst_mtu(&rt->u.dst) && (ntohs(iph->frag_off) & IP_DF)) { 1202 /* Do not fragment multicasts. Alas, IPv4 does not 1203 allow to send ICMP, so that packets will disappear 1204 to blackhole. 1205 */ 1206 1207 IP_INC_STATS_BH(IPSTATS_MIB_FRAGFAILS); 1208 ip_rt_put(rt); 1209 goto out_free; 1210 } 1211 1212 encap += LL_RESERVED_SPACE(dev) + rt->u.dst.header_len; 1213 1214 if (skb_cow(skb, encap)) { 1215 ip_rt_put(rt); 1216 goto out_free; 1217 } 1218 1219 vif->pkt_out++; 1220 vif->bytes_out+=skb->len; 1221 1222 dst_release(skb->dst); 1223 skb->dst = &rt->u.dst; 1224 ip_decrease_ttl(ip_hdr(skb)); 1225 1226 /* FIXME: forward and output firewalls used to be called here. 1227 * What do we do with netfilter? -- RR */ 1228 if (vif->flags & VIFF_TUNNEL) { 1229 ip_encap(skb, vif->local, vif->remote); 1230 /* FIXME: extra output firewall step used to be here. --RR */ 1231 ((struct ip_tunnel *)netdev_priv(vif->dev))->stat.tx_packets++; 1232 ((struct ip_tunnel *)netdev_priv(vif->dev))->stat.tx_bytes+=skb->len; 1233 } 1234 1235 IPCB(skb)->flags |= IPSKB_FORWARDED; 1236 1237 /* 1238 * RFC1584 teaches, that DVMRP/PIM router must deliver packets locally 1239 * not only before forwarding, but after forwarding on all output 1240 * interfaces. It is clear, if mrouter runs a multicasting 1241 * program, it should receive packets not depending to what interface 1242 * program is joined. 1243 * If we will not make it, the program will have to join on all 1244 * interfaces. On the other hand, multihoming host (or router, but 1245 * not mrouter) cannot join to more than one interface - it will 1246 * result in receiving multiple packets. 1247 */ 1248 NF_HOOK(PF_INET, NF_IP_FORWARD, skb, skb->dev, dev, 1249 ipmr_forward_finish); 1250 return; 1251 1252 out_free: 1253 kfree_skb(skb); 1254 return; 1255 } 1256 1257 static int ipmr_find_vif(struct net_device *dev) 1258 { 1259 int ct; 1260 for (ct=maxvif-1; ct>=0; ct--) { 1261 if (vif_table[ct].dev == dev) 1262 break; 1263 } 1264 return ct; 1265 } 1266 1267 /* "local" means that we should preserve one skb (for local delivery) */ 1268 1269 static int ip_mr_forward(struct sk_buff *skb, struct mfc_cache *cache, int local) 1270 { 1271 int psend = -1; 1272 int vif, ct; 1273 1274 vif = cache->mfc_parent; 1275 cache->mfc_un.res.pkt++; 1276 cache->mfc_un.res.bytes += skb->len; 1277 1278 /* 1279 * Wrong interface: drop packet and (maybe) send PIM assert. 1280 */ 1281 if (vif_table[vif].dev != skb->dev) { 1282 int true_vifi; 1283 1284 if (((struct rtable*)skb->dst)->fl.iif == 0) { 1285 /* It is our own packet, looped back. 1286 Very complicated situation... 1287 1288 The best workaround until routing daemons will be 1289 fixed is not to redistribute packet, if it was 1290 send through wrong interface. It means, that 1291 multicast applications WILL NOT work for 1292 (S,G), which have default multicast route pointing 1293 to wrong oif. In any case, it is not a good 1294 idea to use multicasting applications on router. 1295 */ 1296 goto dont_forward; 1297 } 1298 1299 cache->mfc_un.res.wrong_if++; 1300 true_vifi = ipmr_find_vif(skb->dev); 1301 1302 if (true_vifi >= 0 && mroute_do_assert && 1303 /* pimsm uses asserts, when switching from RPT to SPT, 1304 so that we cannot check that packet arrived on an oif. 1305 It is bad, but otherwise we would need to move pretty 1306 large chunk of pimd to kernel. Ough... --ANK 1307 */ 1308 (mroute_do_pim || cache->mfc_un.res.ttls[true_vifi] < 255) && 1309 time_after(jiffies, 1310 cache->mfc_un.res.last_assert + MFC_ASSERT_THRESH)) { 1311 cache->mfc_un.res.last_assert = jiffies; 1312 ipmr_cache_report(skb, true_vifi, IGMPMSG_WRONGVIF); 1313 } 1314 goto dont_forward; 1315 } 1316 1317 vif_table[vif].pkt_in++; 1318 vif_table[vif].bytes_in+=skb->len; 1319 1320 /* 1321 * Forward the frame 1322 */ 1323 for (ct = cache->mfc_un.res.maxvif-1; ct >= cache->mfc_un.res.minvif; ct--) { 1324 if (ip_hdr(skb)->ttl > cache->mfc_un.res.ttls[ct]) { 1325 if (psend != -1) { 1326 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 1327 if (skb2) 1328 ipmr_queue_xmit(skb2, cache, psend); 1329 } 1330 psend=ct; 1331 } 1332 } 1333 if (psend != -1) { 1334 if (local) { 1335 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 1336 if (skb2) 1337 ipmr_queue_xmit(skb2, cache, psend); 1338 } else { 1339 ipmr_queue_xmit(skb, cache, psend); 1340 return 0; 1341 } 1342 } 1343 1344 dont_forward: 1345 if (!local) 1346 kfree_skb(skb); 1347 return 0; 1348 } 1349 1350 1351 /* 1352 * Multicast packets for forwarding arrive here 1353 */ 1354 1355 int ip_mr_input(struct sk_buff *skb) 1356 { 1357 struct mfc_cache *cache; 1358 int local = ((struct rtable*)skb->dst)->rt_flags&RTCF_LOCAL; 1359 1360 /* Packet is looped back after forward, it should not be 1361 forwarded second time, but still can be delivered locally. 1362 */ 1363 if (IPCB(skb)->flags&IPSKB_FORWARDED) 1364 goto dont_forward; 1365 1366 if (!local) { 1367 if (IPCB(skb)->opt.router_alert) { 1368 if (ip_call_ra_chain(skb)) 1369 return 0; 1370 } else if (ip_hdr(skb)->protocol == IPPROTO_IGMP){ 1371 /* IGMPv1 (and broken IGMPv2 implementations sort of 1372 Cisco IOS <= 11.2(8)) do not put router alert 1373 option to IGMP packets destined to routable 1374 groups. It is very bad, because it means 1375 that we can forward NO IGMP messages. 1376 */ 1377 read_lock(&mrt_lock); 1378 if (mroute_socket) { 1379 nf_reset(skb); 1380 raw_rcv(mroute_socket, skb); 1381 read_unlock(&mrt_lock); 1382 return 0; 1383 } 1384 read_unlock(&mrt_lock); 1385 } 1386 } 1387 1388 read_lock(&mrt_lock); 1389 cache = ipmr_cache_find(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr); 1390 1391 /* 1392 * No usable cache entry 1393 */ 1394 if (cache==NULL) { 1395 int vif; 1396 1397 if (local) { 1398 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 1399 ip_local_deliver(skb); 1400 if (skb2 == NULL) { 1401 read_unlock(&mrt_lock); 1402 return -ENOBUFS; 1403 } 1404 skb = skb2; 1405 } 1406 1407 vif = ipmr_find_vif(skb->dev); 1408 if (vif >= 0) { 1409 int err = ipmr_cache_unresolved(vif, skb); 1410 read_unlock(&mrt_lock); 1411 1412 return err; 1413 } 1414 read_unlock(&mrt_lock); 1415 kfree_skb(skb); 1416 return -ENODEV; 1417 } 1418 1419 ip_mr_forward(skb, cache, local); 1420 1421 read_unlock(&mrt_lock); 1422 1423 if (local) 1424 return ip_local_deliver(skb); 1425 1426 return 0; 1427 1428 dont_forward: 1429 if (local) 1430 return ip_local_deliver(skb); 1431 kfree_skb(skb); 1432 return 0; 1433 } 1434 1435 #ifdef CONFIG_IP_PIMSM_V1 1436 /* 1437 * Handle IGMP messages of PIMv1 1438 */ 1439 1440 int pim_rcv_v1(struct sk_buff * skb) 1441 { 1442 struct igmphdr *pim; 1443 struct iphdr *encap; 1444 struct net_device *reg_dev = NULL; 1445 1446 if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(*encap))) 1447 goto drop; 1448 1449 pim = igmp_hdr(skb); 1450 1451 if (!mroute_do_pim || 1452 skb->len < sizeof(*pim) + sizeof(*encap) || 1453 pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER) 1454 goto drop; 1455 1456 encap = (struct iphdr *)(skb_transport_header(skb) + 1457 sizeof(struct igmphdr)); 1458 /* 1459 Check that: 1460 a. packet is really destinted to a multicast group 1461 b. packet is not a NULL-REGISTER 1462 c. packet is not truncated 1463 */ 1464 if (!MULTICAST(encap->daddr) || 1465 encap->tot_len == 0 || 1466 ntohs(encap->tot_len) + sizeof(*pim) > skb->len) 1467 goto drop; 1468 1469 read_lock(&mrt_lock); 1470 if (reg_vif_num >= 0) 1471 reg_dev = vif_table[reg_vif_num].dev; 1472 if (reg_dev) 1473 dev_hold(reg_dev); 1474 read_unlock(&mrt_lock); 1475 1476 if (reg_dev == NULL) 1477 goto drop; 1478 1479 skb->mac_header = skb->network_header; 1480 skb_pull(skb, (u8*)encap - skb->data); 1481 skb_reset_network_header(skb); 1482 skb->dev = reg_dev; 1483 skb->protocol = htons(ETH_P_IP); 1484 skb->ip_summed = 0; 1485 skb->pkt_type = PACKET_HOST; 1486 dst_release(skb->dst); 1487 skb->dst = NULL; 1488 ((struct net_device_stats*)netdev_priv(reg_dev))->rx_bytes += skb->len; 1489 ((struct net_device_stats*)netdev_priv(reg_dev))->rx_packets++; 1490 nf_reset(skb); 1491 netif_rx(skb); 1492 dev_put(reg_dev); 1493 return 0; 1494 drop: 1495 kfree_skb(skb); 1496 return 0; 1497 } 1498 #endif 1499 1500 #ifdef CONFIG_IP_PIMSM_V2 1501 static int pim_rcv(struct sk_buff * skb) 1502 { 1503 struct pimreghdr *pim; 1504 struct iphdr *encap; 1505 struct net_device *reg_dev = NULL; 1506 1507 if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(*encap))) 1508 goto drop; 1509 1510 pim = (struct pimreghdr *)skb_transport_header(skb); 1511 if (pim->type != ((PIM_VERSION<<4)|(PIM_REGISTER)) || 1512 (pim->flags&PIM_NULL_REGISTER) || 1513 (ip_compute_csum((void *)pim, sizeof(*pim)) != 0 && 1514 csum_fold(skb_checksum(skb, 0, skb->len, 0)))) 1515 goto drop; 1516 1517 /* check if the inner packet is destined to mcast group */ 1518 encap = (struct iphdr *)(skb_transport_header(skb) + 1519 sizeof(struct pimreghdr)); 1520 if (!MULTICAST(encap->daddr) || 1521 encap->tot_len == 0 || 1522 ntohs(encap->tot_len) + sizeof(*pim) > skb->len) 1523 goto drop; 1524 1525 read_lock(&mrt_lock); 1526 if (reg_vif_num >= 0) 1527 reg_dev = vif_table[reg_vif_num].dev; 1528 if (reg_dev) 1529 dev_hold(reg_dev); 1530 read_unlock(&mrt_lock); 1531 1532 if (reg_dev == NULL) 1533 goto drop; 1534 1535 skb->mac_header = skb->network_header; 1536 skb_pull(skb, (u8*)encap - skb->data); 1537 skb_reset_network_header(skb); 1538 skb->dev = reg_dev; 1539 skb->protocol = htons(ETH_P_IP); 1540 skb->ip_summed = 0; 1541 skb->pkt_type = PACKET_HOST; 1542 dst_release(skb->dst); 1543 ((struct net_device_stats*)netdev_priv(reg_dev))->rx_bytes += skb->len; 1544 ((struct net_device_stats*)netdev_priv(reg_dev))->rx_packets++; 1545 skb->dst = NULL; 1546 nf_reset(skb); 1547 netif_rx(skb); 1548 dev_put(reg_dev); 1549 return 0; 1550 drop: 1551 kfree_skb(skb); 1552 return 0; 1553 } 1554 #endif 1555 1556 static int 1557 ipmr_fill_mroute(struct sk_buff *skb, struct mfc_cache *c, struct rtmsg *rtm) 1558 { 1559 int ct; 1560 struct rtnexthop *nhp; 1561 struct net_device *dev = vif_table[c->mfc_parent].dev; 1562 u8 *b = skb_tail_pointer(skb); 1563 struct rtattr *mp_head; 1564 1565 if (dev) 1566 RTA_PUT(skb, RTA_IIF, 4, &dev->ifindex); 1567 1568 mp_head = (struct rtattr*)skb_put(skb, RTA_LENGTH(0)); 1569 1570 for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) { 1571 if (c->mfc_un.res.ttls[ct] < 255) { 1572 if (skb_tailroom(skb) < RTA_ALIGN(RTA_ALIGN(sizeof(*nhp)) + 4)) 1573 goto rtattr_failure; 1574 nhp = (struct rtnexthop*)skb_put(skb, RTA_ALIGN(sizeof(*nhp))); 1575 nhp->rtnh_flags = 0; 1576 nhp->rtnh_hops = c->mfc_un.res.ttls[ct]; 1577 nhp->rtnh_ifindex = vif_table[ct].dev->ifindex; 1578 nhp->rtnh_len = sizeof(*nhp); 1579 } 1580 } 1581 mp_head->rta_type = RTA_MULTIPATH; 1582 mp_head->rta_len = skb_tail_pointer(skb) - (u8 *)mp_head; 1583 rtm->rtm_type = RTN_MULTICAST; 1584 return 1; 1585 1586 rtattr_failure: 1587 nlmsg_trim(skb, b); 1588 return -EMSGSIZE; 1589 } 1590 1591 int ipmr_get_route(struct sk_buff *skb, struct rtmsg *rtm, int nowait) 1592 { 1593 int err; 1594 struct mfc_cache *cache; 1595 struct rtable *rt = (struct rtable*)skb->dst; 1596 1597 read_lock(&mrt_lock); 1598 cache = ipmr_cache_find(rt->rt_src, rt->rt_dst); 1599 1600 if (cache==NULL) { 1601 struct sk_buff *skb2; 1602 struct iphdr *iph; 1603 struct net_device *dev; 1604 int vif; 1605 1606 if (nowait) { 1607 read_unlock(&mrt_lock); 1608 return -EAGAIN; 1609 } 1610 1611 dev = skb->dev; 1612 if (dev == NULL || (vif = ipmr_find_vif(dev)) < 0) { 1613 read_unlock(&mrt_lock); 1614 return -ENODEV; 1615 } 1616 skb2 = skb_clone(skb, GFP_ATOMIC); 1617 if (!skb2) { 1618 read_unlock(&mrt_lock); 1619 return -ENOMEM; 1620 } 1621 1622 skb_push(skb2, sizeof(struct iphdr)); 1623 skb_reset_network_header(skb2); 1624 iph = ip_hdr(skb2); 1625 iph->ihl = sizeof(struct iphdr) >> 2; 1626 iph->saddr = rt->rt_src; 1627 iph->daddr = rt->rt_dst; 1628 iph->version = 0; 1629 err = ipmr_cache_unresolved(vif, skb2); 1630 read_unlock(&mrt_lock); 1631 return err; 1632 } 1633 1634 if (!nowait && (rtm->rtm_flags&RTM_F_NOTIFY)) 1635 cache->mfc_flags |= MFC_NOTIFY; 1636 err = ipmr_fill_mroute(skb, cache, rtm); 1637 read_unlock(&mrt_lock); 1638 return err; 1639 } 1640 1641 #ifdef CONFIG_PROC_FS 1642 /* 1643 * The /proc interfaces to multicast routing /proc/ip_mr_cache /proc/ip_mr_vif 1644 */ 1645 struct ipmr_vif_iter { 1646 int ct; 1647 }; 1648 1649 static struct vif_device *ipmr_vif_seq_idx(struct ipmr_vif_iter *iter, 1650 loff_t pos) 1651 { 1652 for (iter->ct = 0; iter->ct < maxvif; ++iter->ct) { 1653 if (!VIF_EXISTS(iter->ct)) 1654 continue; 1655 if (pos-- == 0) 1656 return &vif_table[iter->ct]; 1657 } 1658 return NULL; 1659 } 1660 1661 static void *ipmr_vif_seq_start(struct seq_file *seq, loff_t *pos) 1662 { 1663 read_lock(&mrt_lock); 1664 return *pos ? ipmr_vif_seq_idx(seq->private, *pos - 1) 1665 : SEQ_START_TOKEN; 1666 } 1667 1668 static void *ipmr_vif_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1669 { 1670 struct ipmr_vif_iter *iter = seq->private; 1671 1672 ++*pos; 1673 if (v == SEQ_START_TOKEN) 1674 return ipmr_vif_seq_idx(iter, 0); 1675 1676 while (++iter->ct < maxvif) { 1677 if (!VIF_EXISTS(iter->ct)) 1678 continue; 1679 return &vif_table[iter->ct]; 1680 } 1681 return NULL; 1682 } 1683 1684 static void ipmr_vif_seq_stop(struct seq_file *seq, void *v) 1685 { 1686 read_unlock(&mrt_lock); 1687 } 1688 1689 static int ipmr_vif_seq_show(struct seq_file *seq, void *v) 1690 { 1691 if (v == SEQ_START_TOKEN) { 1692 seq_puts(seq, 1693 "Interface BytesIn PktsIn BytesOut PktsOut Flags Local Remote\n"); 1694 } else { 1695 const struct vif_device *vif = v; 1696 const char *name = vif->dev ? vif->dev->name : "none"; 1697 1698 seq_printf(seq, 1699 "%2Zd %-10s %8ld %7ld %8ld %7ld %05X %08X %08X\n", 1700 vif - vif_table, 1701 name, vif->bytes_in, vif->pkt_in, 1702 vif->bytes_out, vif->pkt_out, 1703 vif->flags, vif->local, vif->remote); 1704 } 1705 return 0; 1706 } 1707 1708 static const struct seq_operations ipmr_vif_seq_ops = { 1709 .start = ipmr_vif_seq_start, 1710 .next = ipmr_vif_seq_next, 1711 .stop = ipmr_vif_seq_stop, 1712 .show = ipmr_vif_seq_show, 1713 }; 1714 1715 static int ipmr_vif_open(struct inode *inode, struct file *file) 1716 { 1717 return seq_open_private(file, &ipmr_vif_seq_ops, 1718 sizeof(struct ipmr_vif_iter)); 1719 } 1720 1721 static const struct file_operations ipmr_vif_fops = { 1722 .owner = THIS_MODULE, 1723 .open = ipmr_vif_open, 1724 .read = seq_read, 1725 .llseek = seq_lseek, 1726 .release = seq_release_private, 1727 }; 1728 1729 struct ipmr_mfc_iter { 1730 struct mfc_cache **cache; 1731 int ct; 1732 }; 1733 1734 1735 static struct mfc_cache *ipmr_mfc_seq_idx(struct ipmr_mfc_iter *it, loff_t pos) 1736 { 1737 struct mfc_cache *mfc; 1738 1739 it->cache = mfc_cache_array; 1740 read_lock(&mrt_lock); 1741 for (it->ct = 0; it->ct < MFC_LINES; it->ct++) 1742 for (mfc = mfc_cache_array[it->ct]; mfc; mfc = mfc->next) 1743 if (pos-- == 0) 1744 return mfc; 1745 read_unlock(&mrt_lock); 1746 1747 it->cache = &mfc_unres_queue; 1748 spin_lock_bh(&mfc_unres_lock); 1749 for (mfc = mfc_unres_queue; mfc; mfc = mfc->next) 1750 if (pos-- == 0) 1751 return mfc; 1752 spin_unlock_bh(&mfc_unres_lock); 1753 1754 it->cache = NULL; 1755 return NULL; 1756 } 1757 1758 1759 static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos) 1760 { 1761 struct ipmr_mfc_iter *it = seq->private; 1762 it->cache = NULL; 1763 it->ct = 0; 1764 return *pos ? ipmr_mfc_seq_idx(seq->private, *pos - 1) 1765 : SEQ_START_TOKEN; 1766 } 1767 1768 static void *ipmr_mfc_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1769 { 1770 struct mfc_cache *mfc = v; 1771 struct ipmr_mfc_iter *it = seq->private; 1772 1773 ++*pos; 1774 1775 if (v == SEQ_START_TOKEN) 1776 return ipmr_mfc_seq_idx(seq->private, 0); 1777 1778 if (mfc->next) 1779 return mfc->next; 1780 1781 if (it->cache == &mfc_unres_queue) 1782 goto end_of_list; 1783 1784 BUG_ON(it->cache != mfc_cache_array); 1785 1786 while (++it->ct < MFC_LINES) { 1787 mfc = mfc_cache_array[it->ct]; 1788 if (mfc) 1789 return mfc; 1790 } 1791 1792 /* exhausted cache_array, show unresolved */ 1793 read_unlock(&mrt_lock); 1794 it->cache = &mfc_unres_queue; 1795 it->ct = 0; 1796 1797 spin_lock_bh(&mfc_unres_lock); 1798 mfc = mfc_unres_queue; 1799 if (mfc) 1800 return mfc; 1801 1802 end_of_list: 1803 spin_unlock_bh(&mfc_unres_lock); 1804 it->cache = NULL; 1805 1806 return NULL; 1807 } 1808 1809 static void ipmr_mfc_seq_stop(struct seq_file *seq, void *v) 1810 { 1811 struct ipmr_mfc_iter *it = seq->private; 1812 1813 if (it->cache == &mfc_unres_queue) 1814 spin_unlock_bh(&mfc_unres_lock); 1815 else if (it->cache == mfc_cache_array) 1816 read_unlock(&mrt_lock); 1817 } 1818 1819 static int ipmr_mfc_seq_show(struct seq_file *seq, void *v) 1820 { 1821 int n; 1822 1823 if (v == SEQ_START_TOKEN) { 1824 seq_puts(seq, 1825 "Group Origin Iif Pkts Bytes Wrong Oifs\n"); 1826 } else { 1827 const struct mfc_cache *mfc = v; 1828 const struct ipmr_mfc_iter *it = seq->private; 1829 1830 seq_printf(seq, "%08lX %08lX %-3d %8ld %8ld %8ld", 1831 (unsigned long) mfc->mfc_mcastgrp, 1832 (unsigned long) mfc->mfc_origin, 1833 mfc->mfc_parent, 1834 mfc->mfc_un.res.pkt, 1835 mfc->mfc_un.res.bytes, 1836 mfc->mfc_un.res.wrong_if); 1837 1838 if (it->cache != &mfc_unres_queue) { 1839 for (n = mfc->mfc_un.res.minvif; 1840 n < mfc->mfc_un.res.maxvif; n++ ) { 1841 if (VIF_EXISTS(n) 1842 && mfc->mfc_un.res.ttls[n] < 255) 1843 seq_printf(seq, 1844 " %2d:%-3d", 1845 n, mfc->mfc_un.res.ttls[n]); 1846 } 1847 } 1848 seq_putc(seq, '\n'); 1849 } 1850 return 0; 1851 } 1852 1853 static const struct seq_operations ipmr_mfc_seq_ops = { 1854 .start = ipmr_mfc_seq_start, 1855 .next = ipmr_mfc_seq_next, 1856 .stop = ipmr_mfc_seq_stop, 1857 .show = ipmr_mfc_seq_show, 1858 }; 1859 1860 static int ipmr_mfc_open(struct inode *inode, struct file *file) 1861 { 1862 return seq_open_private(file, &ipmr_mfc_seq_ops, 1863 sizeof(struct ipmr_mfc_iter)); 1864 } 1865 1866 static const struct file_operations ipmr_mfc_fops = { 1867 .owner = THIS_MODULE, 1868 .open = ipmr_mfc_open, 1869 .read = seq_read, 1870 .llseek = seq_lseek, 1871 .release = seq_release_private, 1872 }; 1873 #endif 1874 1875 #ifdef CONFIG_IP_PIMSM_V2 1876 static struct net_protocol pim_protocol = { 1877 .handler = pim_rcv, 1878 }; 1879 #endif 1880 1881 1882 /* 1883 * Setup for IP multicast routing 1884 */ 1885 1886 void __init ip_mr_init(void) 1887 { 1888 mrt_cachep = kmem_cache_create("ip_mrt_cache", 1889 sizeof(struct mfc_cache), 1890 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, 1891 NULL); 1892 init_timer(&ipmr_expire_timer); 1893 ipmr_expire_timer.function=ipmr_expire_process; 1894 register_netdevice_notifier(&ip_mr_notifier); 1895 #ifdef CONFIG_PROC_FS 1896 proc_net_fops_create(&init_net, "ip_mr_vif", 0, &ipmr_vif_fops); 1897 proc_net_fops_create(&init_net, "ip_mr_cache", 0, &ipmr_mfc_fops); 1898 #endif 1899 } 1900