1 /*
2 * IP multicast routing support for mrouted 3.6/3.8
3 *
4 * (c) 1995 Alan Cox, <alan@lxorguk.ukuu.org.uk>
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 * Fixes:
13 * Michael Chastain : Incorrect size of copying.
14 * Alan Cox : Added the cache manager code
15 * Alan Cox : Fixed the clone/copy bug and device race.
16 * Mike McLagan : Routing by source
17 * Malcolm Beattie : Buffer handling fixes.
18 * Alexey Kuznetsov : Double buffer free and other fixes.
19 * SVR Anand : Fixed several multicast bugs and problems.
20 * Alexey Kuznetsov : Status, optimisations and more.
21 * Brad Parker : Better behaviour on mrouted upcall
22 * overflow.
23 * Carlos Picoto : PIMv1 Support
24 * Pavlin Ivanov Radoslavov: PIMv2 Registers must checksum only PIM header
25 * Relax this requrement to work with older peers.
26 *
27 */
28
29 #include <asm/system.h>
30 #include <asm/uaccess.h>
31 #include <linux/types.h>
32 #include <linux/capability.h>
33 #include <linux/errno.h>
34 #include <linux/timer.h>
35 #include <linux/mm.h>
36 #include <linux/kernel.h>
37 #include <linux/fcntl.h>
38 #include <linux/stat.h>
39 #include <linux/socket.h>
40 #include <linux/in.h>
41 #include <linux/inet.h>
42 #include <linux/netdevice.h>
43 #include <linux/inetdevice.h>
44 #include <linux/igmp.h>
45 #include <linux/proc_fs.h>
46 #include <linux/seq_file.h>
47 #include <linux/mroute.h>
48 #include <linux/init.h>
49 #include <linux/if_ether.h>
50 #include <net/net_namespace.h>
51 #include <net/ip.h>
52 #include <net/protocol.h>
53 #include <linux/skbuff.h>
54 #include <net/route.h>
55 #include <net/sock.h>
56 #include <net/icmp.h>
57 #include <net/udp.h>
58 #include <net/raw.h>
59 #include <linux/notifier.h>
60 #include <linux/if_arp.h>
61 #include <linux/netfilter_ipv4.h>
62 #include <net/ipip.h>
63 #include <net/checksum.h>
64 #include <net/netlink.h>
65
66 #if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
67 #define CONFIG_IP_PIMSM 1
68 #endif
69
70 static struct sock *mroute_socket;
71
72
73 /* Big lock, protecting vif table, mrt cache and mroute socket state.
74 Note that the changes are semaphored via rtnl_lock.
75 */
76
77 static DEFINE_RWLOCK(mrt_lock);
78
79 /*
80 * Multicast router control variables
81 */
82
83 static struct vif_device vif_table[MAXVIFS]; /* Devices */
84 static int maxvif;
85
86 #define VIF_EXISTS(idx) (vif_table[idx].dev != NULL)
87
88 static int mroute_do_assert; /* Set in PIM assert */
89 static int mroute_do_pim;
90
91 static struct mfc_cache *mfc_cache_array[MFC_LINES]; /* Forwarding cache */
92
93 static struct mfc_cache *mfc_unres_queue; /* Queue of unresolved entries */
94 static atomic_t cache_resolve_queue_len; /* Size of unresolved */
95
96 /* Special spinlock for queue of unresolved entries */
97 static DEFINE_SPINLOCK(mfc_unres_lock);
98
99 /* We return to original Alan's scheme. Hash table of resolved
100 entries is changed only in process context and protected
101 with weak lock mrt_lock. Queue of unresolved entries is protected
102 with strong spinlock mfc_unres_lock.
103
104 In this case data path is free of exclusive locks at all.
105 */
106
107 static struct kmem_cache *mrt_cachep __read_mostly;
108
109 static int ip_mr_forward(struct sk_buff *skb, struct mfc_cache *cache, int local);
110 static int ipmr_cache_report(struct sk_buff *pkt, vifi_t vifi, int assert);
111 static int ipmr_fill_mroute(struct sk_buff *skb, struct mfc_cache *c, struct rtmsg *rtm);
112
113 #ifdef CONFIG_IP_PIMSM_V2
114 static struct net_protocol pim_protocol;
115 #endif
116
117 static struct timer_list ipmr_expire_timer;
118
119 /* Service routines creating virtual interfaces: DVMRP tunnels and PIMREG */
120
ipmr_del_tunnel(struct net_device * dev,struct vifctl * v)121 static void ipmr_del_tunnel(struct net_device *dev, struct vifctl *v)
122 {
123 dev_close(dev);
124
125 dev = __dev_get_by_name(&init_net, "tunl0");
126 if (dev) {
127 const struct net_device_ops *ops = dev->netdev_ops;
128 struct ifreq ifr;
129 struct ip_tunnel_parm p;
130
131 memset(&p, 0, sizeof(p));
132 p.iph.daddr = v->vifc_rmt_addr.s_addr;
133 p.iph.saddr = v->vifc_lcl_addr.s_addr;
134 p.iph.version = 4;
135 p.iph.ihl = 5;
136 p.iph.protocol = IPPROTO_IPIP;
137 sprintf(p.name, "dvmrp%d", v->vifc_vifi);
138 ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
139
140 if (ops->ndo_do_ioctl) {
141 mm_segment_t oldfs = get_fs();
142
143 set_fs(KERNEL_DS);
144 ops->ndo_do_ioctl(dev, &ifr, SIOCDELTUNNEL);
145 set_fs(oldfs);
146 }
147 }
148 }
149
150 static
ipmr_new_tunnel(struct vifctl * v)151 struct net_device *ipmr_new_tunnel(struct vifctl *v)
152 {
153 struct net_device *dev;
154
155 dev = __dev_get_by_name(&init_net, "tunl0");
156
157 if (dev) {
158 const struct net_device_ops *ops = dev->netdev_ops;
159 int err;
160 struct ifreq ifr;
161 struct ip_tunnel_parm p;
162 struct in_device *in_dev;
163
164 memset(&p, 0, sizeof(p));
165 p.iph.daddr = v->vifc_rmt_addr.s_addr;
166 p.iph.saddr = v->vifc_lcl_addr.s_addr;
167 p.iph.version = 4;
168 p.iph.ihl = 5;
169 p.iph.protocol = IPPROTO_IPIP;
170 sprintf(p.name, "dvmrp%d", v->vifc_vifi);
171 ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
172
173 if (ops->ndo_do_ioctl) {
174 mm_segment_t oldfs = get_fs();
175
176 set_fs(KERNEL_DS);
177 err = ops->ndo_do_ioctl(dev, &ifr, SIOCADDTUNNEL);
178 set_fs(oldfs);
179 } else
180 err = -EOPNOTSUPP;
181
182 dev = NULL;
183
184 if (err == 0 && (dev = __dev_get_by_name(&init_net, p.name)) != NULL) {
185 dev->flags |= IFF_MULTICAST;
186
187 in_dev = __in_dev_get_rtnl(dev);
188 if (in_dev == NULL)
189 goto failure;
190
191 ipv4_devconf_setall(in_dev);
192 IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
193
194 if (dev_open(dev))
195 goto failure;
196 dev_hold(dev);
197 }
198 }
199 return dev;
200
201 failure:
202 /* allow the register to be completed before unregistering. */
203 rtnl_unlock();
204 rtnl_lock();
205
206 unregister_netdevice(dev);
207 return NULL;
208 }
209
210 #ifdef CONFIG_IP_PIMSM
211
212 static int reg_vif_num = -1;
213
reg_vif_xmit(struct sk_buff * skb,struct net_device * dev)214 static int reg_vif_xmit(struct sk_buff *skb, struct net_device *dev)
215 {
216 read_lock(&mrt_lock);
217 dev->stats.tx_bytes += skb->len;
218 dev->stats.tx_packets++;
219 ipmr_cache_report(skb, reg_vif_num, IGMPMSG_WHOLEPKT);
220 read_unlock(&mrt_lock);
221 kfree_skb(skb);
222 return 0;
223 }
224
225 static const struct net_device_ops reg_vif_netdev_ops = {
226 .ndo_start_xmit = reg_vif_xmit,
227 };
228
reg_vif_setup(struct net_device * dev)229 static void reg_vif_setup(struct net_device *dev)
230 {
231 dev->type = ARPHRD_PIMREG;
232 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr) - 8;
233 dev->flags = IFF_NOARP;
234 dev->netdev_ops = ®_vif_netdev_ops,
235 dev->destructor = free_netdev;
236 }
237
ipmr_reg_vif(void)238 static struct net_device *ipmr_reg_vif(void)
239 {
240 struct net_device *dev;
241 struct in_device *in_dev;
242
243 dev = alloc_netdev(0, "pimreg", reg_vif_setup);
244
245 if (dev == NULL)
246 return NULL;
247
248 if (register_netdevice(dev)) {
249 free_netdev(dev);
250 return NULL;
251 }
252 dev->iflink = 0;
253
254 rcu_read_lock();
255 if ((in_dev = __in_dev_get_rcu(dev)) == NULL) {
256 rcu_read_unlock();
257 goto failure;
258 }
259
260 ipv4_devconf_setall(in_dev);
261 IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
262 rcu_read_unlock();
263
264 if (dev_open(dev))
265 goto failure;
266
267 dev_hold(dev);
268
269 return dev;
270
271 failure:
272 /* allow the register to be completed before unregistering. */
273 rtnl_unlock();
274 rtnl_lock();
275
276 unregister_netdevice(dev);
277 return NULL;
278 }
279 #endif
280
281 /*
282 * Delete a VIF entry
283 * @notify: Set to 1, if the caller is a notifier_call
284 */
285
vif_delete(int vifi,int notify)286 static int vif_delete(int vifi, int notify)
287 {
288 struct vif_device *v;
289 struct net_device *dev;
290 struct in_device *in_dev;
291
292 if (vifi < 0 || vifi >= maxvif)
293 return -EADDRNOTAVAIL;
294
295 v = &vif_table[vifi];
296
297 write_lock_bh(&mrt_lock);
298 dev = v->dev;
299 v->dev = NULL;
300
301 if (!dev) {
302 write_unlock_bh(&mrt_lock);
303 return -EADDRNOTAVAIL;
304 }
305
306 #ifdef CONFIG_IP_PIMSM
307 if (vifi == reg_vif_num)
308 reg_vif_num = -1;
309 #endif
310
311 if (vifi+1 == maxvif) {
312 int tmp;
313 for (tmp=vifi-1; tmp>=0; tmp--) {
314 if (VIF_EXISTS(tmp))
315 break;
316 }
317 maxvif = tmp+1;
318 }
319
320 write_unlock_bh(&mrt_lock);
321
322 dev_set_allmulti(dev, -1);
323
324 if ((in_dev = __in_dev_get_rtnl(dev)) != NULL) {
325 IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)--;
326 ip_rt_multicast_event(in_dev);
327 }
328
329 if (v->flags&(VIFF_TUNNEL|VIFF_REGISTER) && !notify)
330 unregister_netdevice(dev);
331
332 dev_put(dev);
333 return 0;
334 }
335
336 /* Destroy an unresolved cache entry, killing queued skbs
337 and reporting error to netlink readers.
338 */
339
ipmr_destroy_unres(struct mfc_cache * c)340 static void ipmr_destroy_unres(struct mfc_cache *c)
341 {
342 struct sk_buff *skb;
343 struct nlmsgerr *e;
344
345 atomic_dec(&cache_resolve_queue_len);
346
347 while ((skb = skb_dequeue(&c->mfc_un.unres.unresolved))) {
348 if (ip_hdr(skb)->version == 0) {
349 struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr));
350 nlh->nlmsg_type = NLMSG_ERROR;
351 nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct nlmsgerr));
352 skb_trim(skb, nlh->nlmsg_len);
353 e = NLMSG_DATA(nlh);
354 e->error = -ETIMEDOUT;
355 memset(&e->msg, 0, sizeof(e->msg));
356
357 rtnl_unicast(skb, &init_net, NETLINK_CB(skb).pid);
358 } else
359 kfree_skb(skb);
360 }
361
362 kmem_cache_free(mrt_cachep, c);
363 }
364
365
366 /* Single timer process for all the unresolved queue. */
367
ipmr_expire_process(unsigned long dummy)368 static void ipmr_expire_process(unsigned long dummy)
369 {
370 unsigned long now;
371 unsigned long expires;
372 struct mfc_cache *c, **cp;
373
374 if (!spin_trylock(&mfc_unres_lock)) {
375 mod_timer(&ipmr_expire_timer, jiffies+HZ/10);
376 return;
377 }
378
379 if (atomic_read(&cache_resolve_queue_len) == 0)
380 goto out;
381
382 now = jiffies;
383 expires = 10*HZ;
384 cp = &mfc_unres_queue;
385
386 while ((c=*cp) != NULL) {
387 if (time_after(c->mfc_un.unres.expires, now)) {
388 unsigned long interval = c->mfc_un.unres.expires - now;
389 if (interval < expires)
390 expires = interval;
391 cp = &c->next;
392 continue;
393 }
394
395 *cp = c->next;
396
397 ipmr_destroy_unres(c);
398 }
399
400 if (atomic_read(&cache_resolve_queue_len))
401 mod_timer(&ipmr_expire_timer, jiffies + expires);
402
403 out:
404 spin_unlock(&mfc_unres_lock);
405 }
406
407 /* Fill oifs list. It is called under write locked mrt_lock. */
408
ipmr_update_thresholds(struct mfc_cache * cache,unsigned char * ttls)409 static void ipmr_update_thresholds(struct mfc_cache *cache, unsigned char *ttls)
410 {
411 int vifi;
412
413 cache->mfc_un.res.minvif = MAXVIFS;
414 cache->mfc_un.res.maxvif = 0;
415 memset(cache->mfc_un.res.ttls, 255, MAXVIFS);
416
417 for (vifi=0; vifi<maxvif; vifi++) {
418 if (VIF_EXISTS(vifi) && ttls[vifi] && ttls[vifi] < 255) {
419 cache->mfc_un.res.ttls[vifi] = ttls[vifi];
420 if (cache->mfc_un.res.minvif > vifi)
421 cache->mfc_un.res.minvif = vifi;
422 if (cache->mfc_un.res.maxvif <= vifi)
423 cache->mfc_un.res.maxvif = vifi + 1;
424 }
425 }
426 }
427
vif_add(struct vifctl * vifc,int mrtsock)428 static int vif_add(struct vifctl *vifc, int mrtsock)
429 {
430 int vifi = vifc->vifc_vifi;
431 struct vif_device *v = &vif_table[vifi];
432 struct net_device *dev;
433 struct in_device *in_dev;
434 int err;
435
436 /* Is vif busy ? */
437 if (VIF_EXISTS(vifi))
438 return -EADDRINUSE;
439
440 switch (vifc->vifc_flags) {
441 #ifdef CONFIG_IP_PIMSM
442 case VIFF_REGISTER:
443 /*
444 * Special Purpose VIF in PIM
445 * All the packets will be sent to the daemon
446 */
447 if (reg_vif_num >= 0)
448 return -EADDRINUSE;
449 dev = ipmr_reg_vif();
450 if (!dev)
451 return -ENOBUFS;
452 err = dev_set_allmulti(dev, 1);
453 if (err) {
454 unregister_netdevice(dev);
455 dev_put(dev);
456 return err;
457 }
458 break;
459 #endif
460 case VIFF_TUNNEL:
461 dev = ipmr_new_tunnel(vifc);
462 if (!dev)
463 return -ENOBUFS;
464 err = dev_set_allmulti(dev, 1);
465 if (err) {
466 ipmr_del_tunnel(dev, vifc);
467 dev_put(dev);
468 return err;
469 }
470 break;
471 case 0:
472 dev = ip_dev_find(&init_net, vifc->vifc_lcl_addr.s_addr);
473 if (!dev)
474 return -EADDRNOTAVAIL;
475 err = dev_set_allmulti(dev, 1);
476 if (err) {
477 dev_put(dev);
478 return err;
479 }
480 break;
481 default:
482 return -EINVAL;
483 }
484
485 if ((in_dev = __in_dev_get_rtnl(dev)) == NULL)
486 return -EADDRNOTAVAIL;
487 IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)++;
488 ip_rt_multicast_event(in_dev);
489
490 /*
491 * Fill in the VIF structures
492 */
493 v->rate_limit = vifc->vifc_rate_limit;
494 v->local = vifc->vifc_lcl_addr.s_addr;
495 v->remote = vifc->vifc_rmt_addr.s_addr;
496 v->flags = vifc->vifc_flags;
497 if (!mrtsock)
498 v->flags |= VIFF_STATIC;
499 v->threshold = vifc->vifc_threshold;
500 v->bytes_in = 0;
501 v->bytes_out = 0;
502 v->pkt_in = 0;
503 v->pkt_out = 0;
504 v->link = dev->ifindex;
505 if (v->flags&(VIFF_TUNNEL|VIFF_REGISTER))
506 v->link = dev->iflink;
507
508 /* And finish update writing critical data */
509 write_lock_bh(&mrt_lock);
510 v->dev = dev;
511 #ifdef CONFIG_IP_PIMSM
512 if (v->flags&VIFF_REGISTER)
513 reg_vif_num = vifi;
514 #endif
515 if (vifi+1 > maxvif)
516 maxvif = vifi+1;
517 write_unlock_bh(&mrt_lock);
518 return 0;
519 }
520
ipmr_cache_find(__be32 origin,__be32 mcastgrp)521 static struct mfc_cache *ipmr_cache_find(__be32 origin, __be32 mcastgrp)
522 {
523 int line = MFC_HASH(mcastgrp, origin);
524 struct mfc_cache *c;
525
526 for (c=mfc_cache_array[line]; c; c = c->next) {
527 if (c->mfc_origin==origin && c->mfc_mcastgrp==mcastgrp)
528 break;
529 }
530 return c;
531 }
532
533 /*
534 * Allocate a multicast cache entry
535 */
ipmr_cache_alloc(void)536 static struct mfc_cache *ipmr_cache_alloc(void)
537 {
538 struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_KERNEL);
539 if (c == NULL)
540 return NULL;
541 c->mfc_un.res.minvif = MAXVIFS;
542 return c;
543 }
544
ipmr_cache_alloc_unres(void)545 static struct mfc_cache *ipmr_cache_alloc_unres(void)
546 {
547 struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_ATOMIC);
548 if (c == NULL)
549 return NULL;
550 skb_queue_head_init(&c->mfc_un.unres.unresolved);
551 c->mfc_un.unres.expires = jiffies + 10*HZ;
552 return c;
553 }
554
555 /*
556 * A cache entry has gone into a resolved state from queued
557 */
558
ipmr_cache_resolve(struct mfc_cache * uc,struct mfc_cache * c)559 static void ipmr_cache_resolve(struct mfc_cache *uc, struct mfc_cache *c)
560 {
561 struct sk_buff *skb;
562 struct nlmsgerr *e;
563
564 /*
565 * Play the pending entries through our router
566 */
567
568 while ((skb = __skb_dequeue(&uc->mfc_un.unres.unresolved))) {
569 if (ip_hdr(skb)->version == 0) {
570 struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr));
571
572 if (ipmr_fill_mroute(skb, c, NLMSG_DATA(nlh)) > 0) {
573 nlh->nlmsg_len = (skb_tail_pointer(skb) -
574 (u8 *)nlh);
575 } else {
576 nlh->nlmsg_type = NLMSG_ERROR;
577 nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct nlmsgerr));
578 skb_trim(skb, nlh->nlmsg_len);
579 e = NLMSG_DATA(nlh);
580 e->error = -EMSGSIZE;
581 memset(&e->msg, 0, sizeof(e->msg));
582 }
583
584 rtnl_unicast(skb, &init_net, NETLINK_CB(skb).pid);
585 } else
586 ip_mr_forward(skb, c, 0);
587 }
588 }
589
590 /*
591 * Bounce a cache query up to mrouted. We could use netlink for this but mrouted
592 * expects the following bizarre scheme.
593 *
594 * Called under mrt_lock.
595 */
596
ipmr_cache_report(struct sk_buff * pkt,vifi_t vifi,int assert)597 static int ipmr_cache_report(struct sk_buff *pkt, vifi_t vifi, int assert)
598 {
599 struct sk_buff *skb;
600 const int ihl = ip_hdrlen(pkt);
601 struct igmphdr *igmp;
602 struct igmpmsg *msg;
603 int ret;
604
605 #ifdef CONFIG_IP_PIMSM
606 if (assert == IGMPMSG_WHOLEPKT)
607 skb = skb_realloc_headroom(pkt, sizeof(struct iphdr));
608 else
609 #endif
610 skb = alloc_skb(128, GFP_ATOMIC);
611
612 if (!skb)
613 return -ENOBUFS;
614
615 #ifdef CONFIG_IP_PIMSM
616 if (assert == IGMPMSG_WHOLEPKT) {
617 /* Ugly, but we have no choice with this interface.
618 Duplicate old header, fix ihl, length etc.
619 And all this only to mangle msg->im_msgtype and
620 to set msg->im_mbz to "mbz" :-)
621 */
622 skb_push(skb, sizeof(struct iphdr));
623 skb_reset_network_header(skb);
624 skb_reset_transport_header(skb);
625 msg = (struct igmpmsg *)skb_network_header(skb);
626 memcpy(msg, skb_network_header(pkt), sizeof(struct iphdr));
627 msg->im_msgtype = IGMPMSG_WHOLEPKT;
628 msg->im_mbz = 0;
629 msg->im_vif = reg_vif_num;
630 ip_hdr(skb)->ihl = sizeof(struct iphdr) >> 2;
631 ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(pkt)->tot_len) +
632 sizeof(struct iphdr));
633 } else
634 #endif
635 {
636
637 /*
638 * Copy the IP header
639 */
640
641 skb->network_header = skb->tail;
642 skb_put(skb, ihl);
643 skb_copy_to_linear_data(skb, pkt->data, ihl);
644 ip_hdr(skb)->protocol = 0; /* Flag to the kernel this is a route add */
645 msg = (struct igmpmsg *)skb_network_header(skb);
646 msg->im_vif = vifi;
647 skb->dst = dst_clone(pkt->dst);
648
649 /*
650 * Add our header
651 */
652
653 igmp=(struct igmphdr *)skb_put(skb, sizeof(struct igmphdr));
654 igmp->type =
655 msg->im_msgtype = assert;
656 igmp->code = 0;
657 ip_hdr(skb)->tot_len = htons(skb->len); /* Fix the length */
658 skb->transport_header = skb->network_header;
659 }
660
661 if (mroute_socket == NULL) {
662 kfree_skb(skb);
663 return -EINVAL;
664 }
665
666 /*
667 * Deliver to mrouted
668 */
669 if ((ret = sock_queue_rcv_skb(mroute_socket, skb))<0) {
670 if (net_ratelimit())
671 printk(KERN_WARNING "mroute: pending queue full, dropping entries.\n");
672 kfree_skb(skb);
673 }
674
675 return ret;
676 }
677
678 /*
679 * Queue a packet for resolution. It gets locked cache entry!
680 */
681
682 static int
ipmr_cache_unresolved(vifi_t vifi,struct sk_buff * skb)683 ipmr_cache_unresolved(vifi_t vifi, struct sk_buff *skb)
684 {
685 int err;
686 struct mfc_cache *c;
687 const struct iphdr *iph = ip_hdr(skb);
688
689 spin_lock_bh(&mfc_unres_lock);
690 for (c=mfc_unres_queue; c; c=c->next) {
691 if (c->mfc_mcastgrp == iph->daddr &&
692 c->mfc_origin == iph->saddr)
693 break;
694 }
695
696 if (c == NULL) {
697 /*
698 * Create a new entry if allowable
699 */
700
701 if (atomic_read(&cache_resolve_queue_len) >= 10 ||
702 (c=ipmr_cache_alloc_unres())==NULL) {
703 spin_unlock_bh(&mfc_unres_lock);
704
705 kfree_skb(skb);
706 return -ENOBUFS;
707 }
708
709 /*
710 * Fill in the new cache entry
711 */
712 c->mfc_parent = -1;
713 c->mfc_origin = iph->saddr;
714 c->mfc_mcastgrp = iph->daddr;
715
716 /*
717 * Reflect first query at mrouted.
718 */
719 if ((err = ipmr_cache_report(skb, vifi, IGMPMSG_NOCACHE))<0) {
720 /* If the report failed throw the cache entry
721 out - Brad Parker
722 */
723 spin_unlock_bh(&mfc_unres_lock);
724
725 kmem_cache_free(mrt_cachep, c);
726 kfree_skb(skb);
727 return err;
728 }
729
730 atomic_inc(&cache_resolve_queue_len);
731 c->next = mfc_unres_queue;
732 mfc_unres_queue = c;
733
734 mod_timer(&ipmr_expire_timer, c->mfc_un.unres.expires);
735 }
736
737 /*
738 * See if we can append the packet
739 */
740 if (c->mfc_un.unres.unresolved.qlen>3) {
741 kfree_skb(skb);
742 err = -ENOBUFS;
743 } else {
744 skb_queue_tail(&c->mfc_un.unres.unresolved, skb);
745 err = 0;
746 }
747
748 spin_unlock_bh(&mfc_unres_lock);
749 return err;
750 }
751
752 /*
753 * MFC cache manipulation by user space mroute daemon
754 */
755
ipmr_mfc_delete(struct mfcctl * mfc)756 static int ipmr_mfc_delete(struct mfcctl *mfc)
757 {
758 int line;
759 struct mfc_cache *c, **cp;
760
761 line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
762
763 for (cp=&mfc_cache_array[line]; (c=*cp) != NULL; cp = &c->next) {
764 if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
765 c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr) {
766 write_lock_bh(&mrt_lock);
767 *cp = c->next;
768 write_unlock_bh(&mrt_lock);
769
770 kmem_cache_free(mrt_cachep, c);
771 return 0;
772 }
773 }
774 return -ENOENT;
775 }
776
ipmr_mfc_add(struct mfcctl * mfc,int mrtsock)777 static int ipmr_mfc_add(struct mfcctl *mfc, int mrtsock)
778 {
779 int line;
780 struct mfc_cache *uc, *c, **cp;
781
782 line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
783
784 for (cp=&mfc_cache_array[line]; (c=*cp) != NULL; cp = &c->next) {
785 if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
786 c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr)
787 break;
788 }
789
790 if (c != NULL) {
791 write_lock_bh(&mrt_lock);
792 c->mfc_parent = mfc->mfcc_parent;
793 ipmr_update_thresholds(c, mfc->mfcc_ttls);
794 if (!mrtsock)
795 c->mfc_flags |= MFC_STATIC;
796 write_unlock_bh(&mrt_lock);
797 return 0;
798 }
799
800 if (!ipv4_is_multicast(mfc->mfcc_mcastgrp.s_addr))
801 return -EINVAL;
802
803 c = ipmr_cache_alloc();
804 if (c == NULL)
805 return -ENOMEM;
806
807 c->mfc_origin = mfc->mfcc_origin.s_addr;
808 c->mfc_mcastgrp = mfc->mfcc_mcastgrp.s_addr;
809 c->mfc_parent = mfc->mfcc_parent;
810 ipmr_update_thresholds(c, mfc->mfcc_ttls);
811 if (!mrtsock)
812 c->mfc_flags |= MFC_STATIC;
813
814 write_lock_bh(&mrt_lock);
815 c->next = mfc_cache_array[line];
816 mfc_cache_array[line] = c;
817 write_unlock_bh(&mrt_lock);
818
819 /*
820 * Check to see if we resolved a queued list. If so we
821 * need to send on the frames and tidy up.
822 */
823 spin_lock_bh(&mfc_unres_lock);
824 for (cp = &mfc_unres_queue; (uc=*cp) != NULL;
825 cp = &uc->next) {
826 if (uc->mfc_origin == c->mfc_origin &&
827 uc->mfc_mcastgrp == c->mfc_mcastgrp) {
828 *cp = uc->next;
829 if (atomic_dec_and_test(&cache_resolve_queue_len))
830 del_timer(&ipmr_expire_timer);
831 break;
832 }
833 }
834 spin_unlock_bh(&mfc_unres_lock);
835
836 if (uc) {
837 ipmr_cache_resolve(uc, c);
838 kmem_cache_free(mrt_cachep, uc);
839 }
840 return 0;
841 }
842
843 /*
844 * Close the multicast socket, and clear the vif tables etc
845 */
846
mroute_clean_tables(struct sock * sk)847 static void mroute_clean_tables(struct sock *sk)
848 {
849 int i;
850
851 /*
852 * Shut down all active vif entries
853 */
854 for (i=0; i<maxvif; i++) {
855 if (!(vif_table[i].flags&VIFF_STATIC))
856 vif_delete(i, 0);
857 }
858
859 /*
860 * Wipe the cache
861 */
862 for (i=0; i<MFC_LINES; i++) {
863 struct mfc_cache *c, **cp;
864
865 cp = &mfc_cache_array[i];
866 while ((c = *cp) != NULL) {
867 if (c->mfc_flags&MFC_STATIC) {
868 cp = &c->next;
869 continue;
870 }
871 write_lock_bh(&mrt_lock);
872 *cp = c->next;
873 write_unlock_bh(&mrt_lock);
874
875 kmem_cache_free(mrt_cachep, c);
876 }
877 }
878
879 if (atomic_read(&cache_resolve_queue_len) != 0) {
880 struct mfc_cache *c;
881
882 spin_lock_bh(&mfc_unres_lock);
883 while (mfc_unres_queue != NULL) {
884 c = mfc_unres_queue;
885 mfc_unres_queue = c->next;
886 spin_unlock_bh(&mfc_unres_lock);
887
888 ipmr_destroy_unres(c);
889
890 spin_lock_bh(&mfc_unres_lock);
891 }
892 spin_unlock_bh(&mfc_unres_lock);
893 }
894 }
895
mrtsock_destruct(struct sock * sk)896 static void mrtsock_destruct(struct sock *sk)
897 {
898 rtnl_lock();
899 if (sk == mroute_socket) {
900 IPV4_DEVCONF_ALL(sock_net(sk), MC_FORWARDING)--;
901
902 write_lock_bh(&mrt_lock);
903 mroute_socket = NULL;
904 write_unlock_bh(&mrt_lock);
905
906 mroute_clean_tables(sk);
907 }
908 rtnl_unlock();
909 }
910
911 /*
912 * Socket options and virtual interface manipulation. The whole
913 * virtual interface system is a complete heap, but unfortunately
914 * that's how BSD mrouted happens to think. Maybe one day with a proper
915 * MOSPF/PIM router set up we can clean this up.
916 */
917
ip_mroute_setsockopt(struct sock * sk,int optname,char __user * optval,int optlen)918 int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, int optlen)
919 {
920 int ret;
921 struct vifctl vif;
922 struct mfcctl mfc;
923
924 if (optname != MRT_INIT) {
925 if (sk != mroute_socket && !capable(CAP_NET_ADMIN))
926 return -EACCES;
927 }
928
929 switch (optname) {
930 case MRT_INIT:
931 if (sk->sk_type != SOCK_RAW ||
932 inet_sk(sk)->num != IPPROTO_IGMP)
933 return -EOPNOTSUPP;
934 if (optlen != sizeof(int))
935 return -ENOPROTOOPT;
936
937 rtnl_lock();
938 if (mroute_socket) {
939 rtnl_unlock();
940 return -EADDRINUSE;
941 }
942
943 ret = ip_ra_control(sk, 1, mrtsock_destruct);
944 if (ret == 0) {
945 write_lock_bh(&mrt_lock);
946 mroute_socket = sk;
947 write_unlock_bh(&mrt_lock);
948
949 IPV4_DEVCONF_ALL(sock_net(sk), MC_FORWARDING)++;
950 }
951 rtnl_unlock();
952 return ret;
953 case MRT_DONE:
954 if (sk != mroute_socket)
955 return -EACCES;
956 return ip_ra_control(sk, 0, NULL);
957 case MRT_ADD_VIF:
958 case MRT_DEL_VIF:
959 if (optlen != sizeof(vif))
960 return -EINVAL;
961 if (copy_from_user(&vif, optval, sizeof(vif)))
962 return -EFAULT;
963 if (vif.vifc_vifi >= MAXVIFS)
964 return -ENFILE;
965 rtnl_lock();
966 if (optname == MRT_ADD_VIF) {
967 ret = vif_add(&vif, sk==mroute_socket);
968 } else {
969 ret = vif_delete(vif.vifc_vifi, 0);
970 }
971 rtnl_unlock();
972 return ret;
973
974 /*
975 * Manipulate the forwarding caches. These live
976 * in a sort of kernel/user symbiosis.
977 */
978 case MRT_ADD_MFC:
979 case MRT_DEL_MFC:
980 if (optlen != sizeof(mfc))
981 return -EINVAL;
982 if (copy_from_user(&mfc, optval, sizeof(mfc)))
983 return -EFAULT;
984 rtnl_lock();
985 if (optname == MRT_DEL_MFC)
986 ret = ipmr_mfc_delete(&mfc);
987 else
988 ret = ipmr_mfc_add(&mfc, sk==mroute_socket);
989 rtnl_unlock();
990 return ret;
991 /*
992 * Control PIM assert.
993 */
994 case MRT_ASSERT:
995 {
996 int v;
997 if (get_user(v,(int __user *)optval))
998 return -EFAULT;
999 mroute_do_assert=(v)?1:0;
1000 return 0;
1001 }
1002 #ifdef CONFIG_IP_PIMSM
1003 case MRT_PIM:
1004 {
1005 int v;
1006
1007 if (get_user(v,(int __user *)optval))
1008 return -EFAULT;
1009 v = (v) ? 1 : 0;
1010
1011 rtnl_lock();
1012 ret = 0;
1013 if (v != mroute_do_pim) {
1014 mroute_do_pim = v;
1015 mroute_do_assert = v;
1016 #ifdef CONFIG_IP_PIMSM_V2
1017 if (mroute_do_pim)
1018 ret = inet_add_protocol(&pim_protocol,
1019 IPPROTO_PIM);
1020 else
1021 ret = inet_del_protocol(&pim_protocol,
1022 IPPROTO_PIM);
1023 if (ret < 0)
1024 ret = -EAGAIN;
1025 #endif
1026 }
1027 rtnl_unlock();
1028 return ret;
1029 }
1030 #endif
1031 /*
1032 * Spurious command, or MRT_VERSION which you cannot
1033 * set.
1034 */
1035 default:
1036 return -ENOPROTOOPT;
1037 }
1038 }
1039
1040 /*
1041 * Getsock opt support for the multicast routing system.
1042 */
1043
ip_mroute_getsockopt(struct sock * sk,int optname,char __user * optval,int __user * optlen)1044 int ip_mroute_getsockopt(struct sock *sk, int optname, char __user *optval, int __user *optlen)
1045 {
1046 int olr;
1047 int val;
1048
1049 if (optname != MRT_VERSION &&
1050 #ifdef CONFIG_IP_PIMSM
1051 optname!=MRT_PIM &&
1052 #endif
1053 optname!=MRT_ASSERT)
1054 return -ENOPROTOOPT;
1055
1056 if (get_user(olr, optlen))
1057 return -EFAULT;
1058
1059 olr = min_t(unsigned int, olr, sizeof(int));
1060 if (olr < 0)
1061 return -EINVAL;
1062
1063 if (put_user(olr, optlen))
1064 return -EFAULT;
1065 if (optname == MRT_VERSION)
1066 val = 0x0305;
1067 #ifdef CONFIG_IP_PIMSM
1068 else if (optname == MRT_PIM)
1069 val = mroute_do_pim;
1070 #endif
1071 else
1072 val = mroute_do_assert;
1073 if (copy_to_user(optval, &val, olr))
1074 return -EFAULT;
1075 return 0;
1076 }
1077
1078 /*
1079 * The IP multicast ioctl support routines.
1080 */
1081
ipmr_ioctl(struct sock * sk,int cmd,void __user * arg)1082 int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg)
1083 {
1084 struct sioc_sg_req sr;
1085 struct sioc_vif_req vr;
1086 struct vif_device *vif;
1087 struct mfc_cache *c;
1088
1089 switch (cmd) {
1090 case SIOCGETVIFCNT:
1091 if (copy_from_user(&vr, arg, sizeof(vr)))
1092 return -EFAULT;
1093 if (vr.vifi >= maxvif)
1094 return -EINVAL;
1095 read_lock(&mrt_lock);
1096 vif=&vif_table[vr.vifi];
1097 if (VIF_EXISTS(vr.vifi)) {
1098 vr.icount = vif->pkt_in;
1099 vr.ocount = vif->pkt_out;
1100 vr.ibytes = vif->bytes_in;
1101 vr.obytes = vif->bytes_out;
1102 read_unlock(&mrt_lock);
1103
1104 if (copy_to_user(arg, &vr, sizeof(vr)))
1105 return -EFAULT;
1106 return 0;
1107 }
1108 read_unlock(&mrt_lock);
1109 return -EADDRNOTAVAIL;
1110 case SIOCGETSGCNT:
1111 if (copy_from_user(&sr, arg, sizeof(sr)))
1112 return -EFAULT;
1113
1114 read_lock(&mrt_lock);
1115 c = ipmr_cache_find(sr.src.s_addr, sr.grp.s_addr);
1116 if (c) {
1117 sr.pktcnt = c->mfc_un.res.pkt;
1118 sr.bytecnt = c->mfc_un.res.bytes;
1119 sr.wrong_if = c->mfc_un.res.wrong_if;
1120 read_unlock(&mrt_lock);
1121
1122 if (copy_to_user(arg, &sr, sizeof(sr)))
1123 return -EFAULT;
1124 return 0;
1125 }
1126 read_unlock(&mrt_lock);
1127 return -EADDRNOTAVAIL;
1128 default:
1129 return -ENOIOCTLCMD;
1130 }
1131 }
1132
1133
ipmr_device_event(struct notifier_block * this,unsigned long event,void * ptr)1134 static int ipmr_device_event(struct notifier_block *this, unsigned long event, void *ptr)
1135 {
1136 struct net_device *dev = ptr;
1137 struct vif_device *v;
1138 int ct;
1139
1140 if (!net_eq(dev_net(dev), &init_net))
1141 return NOTIFY_DONE;
1142
1143 if (event != NETDEV_UNREGISTER)
1144 return NOTIFY_DONE;
1145 v=&vif_table[0];
1146 for (ct=0; ct<maxvif; ct++,v++) {
1147 if (v->dev == dev)
1148 vif_delete(ct, 1);
1149 }
1150 return NOTIFY_DONE;
1151 }
1152
1153
1154 static struct notifier_block ip_mr_notifier = {
1155 .notifier_call = ipmr_device_event,
1156 };
1157
1158 /*
1159 * Encapsulate a packet by attaching a valid IPIP header to it.
1160 * This avoids tunnel drivers and other mess and gives us the speed so
1161 * important for multicast video.
1162 */
1163
ip_encap(struct sk_buff * skb,__be32 saddr,__be32 daddr)1164 static void ip_encap(struct sk_buff *skb, __be32 saddr, __be32 daddr)
1165 {
1166 struct iphdr *iph;
1167 struct iphdr *old_iph = ip_hdr(skb);
1168
1169 skb_push(skb, sizeof(struct iphdr));
1170 skb->transport_header = skb->network_header;
1171 skb_reset_network_header(skb);
1172 iph = ip_hdr(skb);
1173
1174 iph->version = 4;
1175 iph->tos = old_iph->tos;
1176 iph->ttl = old_iph->ttl;
1177 iph->frag_off = 0;
1178 iph->daddr = daddr;
1179 iph->saddr = saddr;
1180 iph->protocol = IPPROTO_IPIP;
1181 iph->ihl = 5;
1182 iph->tot_len = htons(skb->len);
1183 ip_select_ident(iph, skb->dst, NULL);
1184 ip_send_check(iph);
1185
1186 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1187 nf_reset(skb);
1188 }
1189
ipmr_forward_finish(struct sk_buff * skb)1190 static inline int ipmr_forward_finish(struct sk_buff *skb)
1191 {
1192 struct ip_options * opt = &(IPCB(skb)->opt);
1193
1194 IP_INC_STATS_BH(dev_net(skb->dst->dev), IPSTATS_MIB_OUTFORWDATAGRAMS);
1195
1196 if (unlikely(opt->optlen))
1197 ip_forward_options(skb);
1198
1199 return dst_output(skb);
1200 }
1201
1202 /*
1203 * Processing handlers for ipmr_forward
1204 */
1205
ipmr_queue_xmit(struct sk_buff * skb,struct mfc_cache * c,int vifi)1206 static void ipmr_queue_xmit(struct sk_buff *skb, struct mfc_cache *c, int vifi)
1207 {
1208 const struct iphdr *iph = ip_hdr(skb);
1209 struct vif_device *vif = &vif_table[vifi];
1210 struct net_device *dev;
1211 struct rtable *rt;
1212 int encap = 0;
1213
1214 if (vif->dev == NULL)
1215 goto out_free;
1216
1217 #ifdef CONFIG_IP_PIMSM
1218 if (vif->flags & VIFF_REGISTER) {
1219 vif->pkt_out++;
1220 vif->bytes_out += skb->len;
1221 vif->dev->stats.tx_bytes += skb->len;
1222 vif->dev->stats.tx_packets++;
1223 ipmr_cache_report(skb, vifi, IGMPMSG_WHOLEPKT);
1224 kfree_skb(skb);
1225 return;
1226 }
1227 #endif
1228
1229 if (vif->flags&VIFF_TUNNEL) {
1230 struct flowi fl = { .oif = vif->link,
1231 .nl_u = { .ip4_u =
1232 { .daddr = vif->remote,
1233 .saddr = vif->local,
1234 .tos = RT_TOS(iph->tos) } },
1235 .proto = IPPROTO_IPIP };
1236 if (ip_route_output_key(&init_net, &rt, &fl))
1237 goto out_free;
1238 encap = sizeof(struct iphdr);
1239 } else {
1240 struct flowi fl = { .oif = vif->link,
1241 .nl_u = { .ip4_u =
1242 { .daddr = iph->daddr,
1243 .tos = RT_TOS(iph->tos) } },
1244 .proto = IPPROTO_IPIP };
1245 if (ip_route_output_key(&init_net, &rt, &fl))
1246 goto out_free;
1247 }
1248
1249 dev = rt->u.dst.dev;
1250
1251 if (skb->len+encap > dst_mtu(&rt->u.dst) && (ntohs(iph->frag_off) & IP_DF)) {
1252 /* Do not fragment multicasts. Alas, IPv4 does not
1253 allow to send ICMP, so that packets will disappear
1254 to blackhole.
1255 */
1256
1257 IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_FRAGFAILS);
1258 ip_rt_put(rt);
1259 goto out_free;
1260 }
1261
1262 encap += LL_RESERVED_SPACE(dev) + rt->u.dst.header_len;
1263
1264 if (skb_cow(skb, encap)) {
1265 ip_rt_put(rt);
1266 goto out_free;
1267 }
1268
1269 vif->pkt_out++;
1270 vif->bytes_out += skb->len;
1271
1272 dst_release(skb->dst);
1273 skb->dst = &rt->u.dst;
1274 ip_decrease_ttl(ip_hdr(skb));
1275
1276 /* FIXME: forward and output firewalls used to be called here.
1277 * What do we do with netfilter? -- RR */
1278 if (vif->flags & VIFF_TUNNEL) {
1279 ip_encap(skb, vif->local, vif->remote);
1280 /* FIXME: extra output firewall step used to be here. --RR */
1281 vif->dev->stats.tx_packets++;
1282 vif->dev->stats.tx_bytes += skb->len;
1283 }
1284
1285 IPCB(skb)->flags |= IPSKB_FORWARDED;
1286
1287 /*
1288 * RFC1584 teaches, that DVMRP/PIM router must deliver packets locally
1289 * not only before forwarding, but after forwarding on all output
1290 * interfaces. It is clear, if mrouter runs a multicasting
1291 * program, it should receive packets not depending to what interface
1292 * program is joined.
1293 * If we will not make it, the program will have to join on all
1294 * interfaces. On the other hand, multihoming host (or router, but
1295 * not mrouter) cannot join to more than one interface - it will
1296 * result in receiving multiple packets.
1297 */
1298 NF_HOOK(PF_INET, NF_INET_FORWARD, skb, skb->dev, dev,
1299 ipmr_forward_finish);
1300 return;
1301
1302 out_free:
1303 kfree_skb(skb);
1304 return;
1305 }
1306
ipmr_find_vif(struct net_device * dev)1307 static int ipmr_find_vif(struct net_device *dev)
1308 {
1309 int ct;
1310 for (ct=maxvif-1; ct>=0; ct--) {
1311 if (vif_table[ct].dev == dev)
1312 break;
1313 }
1314 return ct;
1315 }
1316
1317 /* "local" means that we should preserve one skb (for local delivery) */
1318
ip_mr_forward(struct sk_buff * skb,struct mfc_cache * cache,int local)1319 static int ip_mr_forward(struct sk_buff *skb, struct mfc_cache *cache, int local)
1320 {
1321 int psend = -1;
1322 int vif, ct;
1323
1324 vif = cache->mfc_parent;
1325 cache->mfc_un.res.pkt++;
1326 cache->mfc_un.res.bytes += skb->len;
1327
1328 /*
1329 * Wrong interface: drop packet and (maybe) send PIM assert.
1330 */
1331 if (vif_table[vif].dev != skb->dev) {
1332 int true_vifi;
1333
1334 if (skb->rtable->fl.iif == 0) {
1335 /* It is our own packet, looped back.
1336 Very complicated situation...
1337
1338 The best workaround until routing daemons will be
1339 fixed is not to redistribute packet, if it was
1340 send through wrong interface. It means, that
1341 multicast applications WILL NOT work for
1342 (S,G), which have default multicast route pointing
1343 to wrong oif. In any case, it is not a good
1344 idea to use multicasting applications on router.
1345 */
1346 goto dont_forward;
1347 }
1348
1349 cache->mfc_un.res.wrong_if++;
1350 true_vifi = ipmr_find_vif(skb->dev);
1351
1352 if (true_vifi >= 0 && mroute_do_assert &&
1353 /* pimsm uses asserts, when switching from RPT to SPT,
1354 so that we cannot check that packet arrived on an oif.
1355 It is bad, but otherwise we would need to move pretty
1356 large chunk of pimd to kernel. Ough... --ANK
1357 */
1358 (mroute_do_pim || cache->mfc_un.res.ttls[true_vifi] < 255) &&
1359 time_after(jiffies,
1360 cache->mfc_un.res.last_assert + MFC_ASSERT_THRESH)) {
1361 cache->mfc_un.res.last_assert = jiffies;
1362 ipmr_cache_report(skb, true_vifi, IGMPMSG_WRONGVIF);
1363 }
1364 goto dont_forward;
1365 }
1366
1367 vif_table[vif].pkt_in++;
1368 vif_table[vif].bytes_in += skb->len;
1369
1370 /*
1371 * Forward the frame
1372 */
1373 for (ct = cache->mfc_un.res.maxvif-1; ct >= cache->mfc_un.res.minvif; ct--) {
1374 if (ip_hdr(skb)->ttl > cache->mfc_un.res.ttls[ct]) {
1375 if (psend != -1) {
1376 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1377 if (skb2)
1378 ipmr_queue_xmit(skb2, cache, psend);
1379 }
1380 psend = ct;
1381 }
1382 }
1383 if (psend != -1) {
1384 if (local) {
1385 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1386 if (skb2)
1387 ipmr_queue_xmit(skb2, cache, psend);
1388 } else {
1389 ipmr_queue_xmit(skb, cache, psend);
1390 return 0;
1391 }
1392 }
1393
1394 dont_forward:
1395 if (!local)
1396 kfree_skb(skb);
1397 return 0;
1398 }
1399
1400
1401 /*
1402 * Multicast packets for forwarding arrive here
1403 */
1404
ip_mr_input(struct sk_buff * skb)1405 int ip_mr_input(struct sk_buff *skb)
1406 {
1407 struct mfc_cache *cache;
1408 int local = skb->rtable->rt_flags&RTCF_LOCAL;
1409
1410 /* Packet is looped back after forward, it should not be
1411 forwarded second time, but still can be delivered locally.
1412 */
1413 if (IPCB(skb)->flags&IPSKB_FORWARDED)
1414 goto dont_forward;
1415
1416 if (!local) {
1417 if (IPCB(skb)->opt.router_alert) {
1418 if (ip_call_ra_chain(skb))
1419 return 0;
1420 } else if (ip_hdr(skb)->protocol == IPPROTO_IGMP){
1421 /* IGMPv1 (and broken IGMPv2 implementations sort of
1422 Cisco IOS <= 11.2(8)) do not put router alert
1423 option to IGMP packets destined to routable
1424 groups. It is very bad, because it means
1425 that we can forward NO IGMP messages.
1426 */
1427 read_lock(&mrt_lock);
1428 if (mroute_socket) {
1429 nf_reset(skb);
1430 raw_rcv(mroute_socket, skb);
1431 read_unlock(&mrt_lock);
1432 return 0;
1433 }
1434 read_unlock(&mrt_lock);
1435 }
1436 }
1437
1438 read_lock(&mrt_lock);
1439 cache = ipmr_cache_find(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
1440
1441 /*
1442 * No usable cache entry
1443 */
1444 if (cache == NULL) {
1445 int vif;
1446
1447 if (local) {
1448 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1449 ip_local_deliver(skb);
1450 if (skb2 == NULL) {
1451 read_unlock(&mrt_lock);
1452 return -ENOBUFS;
1453 }
1454 skb = skb2;
1455 }
1456
1457 vif = ipmr_find_vif(skb->dev);
1458 if (vif >= 0) {
1459 int err = ipmr_cache_unresolved(vif, skb);
1460 read_unlock(&mrt_lock);
1461
1462 return err;
1463 }
1464 read_unlock(&mrt_lock);
1465 kfree_skb(skb);
1466 return -ENODEV;
1467 }
1468
1469 ip_mr_forward(skb, cache, local);
1470
1471 read_unlock(&mrt_lock);
1472
1473 if (local)
1474 return ip_local_deliver(skb);
1475
1476 return 0;
1477
1478 dont_forward:
1479 if (local)
1480 return ip_local_deliver(skb);
1481 kfree_skb(skb);
1482 return 0;
1483 }
1484
1485 #ifdef CONFIG_IP_PIMSM
__pim_rcv(struct sk_buff * skb,unsigned int pimlen)1486 static int __pim_rcv(struct sk_buff *skb, unsigned int pimlen)
1487 {
1488 struct net_device *reg_dev = NULL;
1489 struct iphdr *encap;
1490
1491 encap = (struct iphdr *)(skb_transport_header(skb) + pimlen);
1492 /*
1493 Check that:
1494 a. packet is really destinted to a multicast group
1495 b. packet is not a NULL-REGISTER
1496 c. packet is not truncated
1497 */
1498 if (!ipv4_is_multicast(encap->daddr) ||
1499 encap->tot_len == 0 ||
1500 ntohs(encap->tot_len) + pimlen > skb->len)
1501 return 1;
1502
1503 read_lock(&mrt_lock);
1504 if (reg_vif_num >= 0)
1505 reg_dev = vif_table[reg_vif_num].dev;
1506 if (reg_dev)
1507 dev_hold(reg_dev);
1508 read_unlock(&mrt_lock);
1509
1510 if (reg_dev == NULL)
1511 return 1;
1512
1513 skb->mac_header = skb->network_header;
1514 skb_pull(skb, (u8*)encap - skb->data);
1515 skb_reset_network_header(skb);
1516 skb->dev = reg_dev;
1517 skb->protocol = htons(ETH_P_IP);
1518 skb->ip_summed = 0;
1519 skb->pkt_type = PACKET_HOST;
1520 dst_release(skb->dst);
1521 skb->dst = NULL;
1522 reg_dev->stats.rx_bytes += skb->len;
1523 reg_dev->stats.rx_packets++;
1524 nf_reset(skb);
1525 netif_rx(skb);
1526 dev_put(reg_dev);
1527
1528 return 0;
1529 }
1530 #endif
1531
1532 #ifdef CONFIG_IP_PIMSM_V1
1533 /*
1534 * Handle IGMP messages of PIMv1
1535 */
1536
pim_rcv_v1(struct sk_buff * skb)1537 int pim_rcv_v1(struct sk_buff * skb)
1538 {
1539 struct igmphdr *pim;
1540
1541 if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
1542 goto drop;
1543
1544 pim = igmp_hdr(skb);
1545
1546 if (!mroute_do_pim ||
1547 pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER)
1548 goto drop;
1549
1550 if (__pim_rcv(skb, sizeof(*pim))) {
1551 drop:
1552 kfree_skb(skb);
1553 }
1554 return 0;
1555 }
1556 #endif
1557
1558 #ifdef CONFIG_IP_PIMSM_V2
pim_rcv(struct sk_buff * skb)1559 static int pim_rcv(struct sk_buff * skb)
1560 {
1561 struct pimreghdr *pim;
1562
1563 if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
1564 goto drop;
1565
1566 pim = (struct pimreghdr *)skb_transport_header(skb);
1567 if (pim->type != ((PIM_VERSION<<4)|(PIM_REGISTER)) ||
1568 (pim->flags&PIM_NULL_REGISTER) ||
1569 (ip_compute_csum((void *)pim, sizeof(*pim)) != 0 &&
1570 csum_fold(skb_checksum(skb, 0, skb->len, 0))))
1571 goto drop;
1572
1573 if (__pim_rcv(skb, sizeof(*pim))) {
1574 drop:
1575 kfree_skb(skb);
1576 }
1577 return 0;
1578 }
1579 #endif
1580
1581 static int
ipmr_fill_mroute(struct sk_buff * skb,struct mfc_cache * c,struct rtmsg * rtm)1582 ipmr_fill_mroute(struct sk_buff *skb, struct mfc_cache *c, struct rtmsg *rtm)
1583 {
1584 int ct;
1585 struct rtnexthop *nhp;
1586 struct net_device *dev = vif_table[c->mfc_parent].dev;
1587 u8 *b = skb_tail_pointer(skb);
1588 struct rtattr *mp_head;
1589
1590 if (dev)
1591 RTA_PUT(skb, RTA_IIF, 4, &dev->ifindex);
1592
1593 mp_head = (struct rtattr *)skb_put(skb, RTA_LENGTH(0));
1594
1595 for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) {
1596 if (c->mfc_un.res.ttls[ct] < 255) {
1597 if (skb_tailroom(skb) < RTA_ALIGN(RTA_ALIGN(sizeof(*nhp)) + 4))
1598 goto rtattr_failure;
1599 nhp = (struct rtnexthop *)skb_put(skb, RTA_ALIGN(sizeof(*nhp)));
1600 nhp->rtnh_flags = 0;
1601 nhp->rtnh_hops = c->mfc_un.res.ttls[ct];
1602 nhp->rtnh_ifindex = vif_table[ct].dev->ifindex;
1603 nhp->rtnh_len = sizeof(*nhp);
1604 }
1605 }
1606 mp_head->rta_type = RTA_MULTIPATH;
1607 mp_head->rta_len = skb_tail_pointer(skb) - (u8 *)mp_head;
1608 rtm->rtm_type = RTN_MULTICAST;
1609 return 1;
1610
1611 rtattr_failure:
1612 nlmsg_trim(skb, b);
1613 return -EMSGSIZE;
1614 }
1615
ipmr_get_route(struct sk_buff * skb,struct rtmsg * rtm,int nowait)1616 int ipmr_get_route(struct sk_buff *skb, struct rtmsg *rtm, int nowait)
1617 {
1618 int err;
1619 struct mfc_cache *cache;
1620 struct rtable *rt = skb->rtable;
1621
1622 read_lock(&mrt_lock);
1623 cache = ipmr_cache_find(rt->rt_src, rt->rt_dst);
1624
1625 if (cache == NULL) {
1626 struct sk_buff *skb2;
1627 struct iphdr *iph;
1628 struct net_device *dev;
1629 int vif;
1630
1631 if (nowait) {
1632 read_unlock(&mrt_lock);
1633 return -EAGAIN;
1634 }
1635
1636 dev = skb->dev;
1637 if (dev == NULL || (vif = ipmr_find_vif(dev)) < 0) {
1638 read_unlock(&mrt_lock);
1639 return -ENODEV;
1640 }
1641 skb2 = skb_clone(skb, GFP_ATOMIC);
1642 if (!skb2) {
1643 read_unlock(&mrt_lock);
1644 return -ENOMEM;
1645 }
1646
1647 skb_push(skb2, sizeof(struct iphdr));
1648 skb_reset_network_header(skb2);
1649 iph = ip_hdr(skb2);
1650 iph->ihl = sizeof(struct iphdr) >> 2;
1651 iph->saddr = rt->rt_src;
1652 iph->daddr = rt->rt_dst;
1653 iph->version = 0;
1654 err = ipmr_cache_unresolved(vif, skb2);
1655 read_unlock(&mrt_lock);
1656 return err;
1657 }
1658
1659 if (!nowait && (rtm->rtm_flags&RTM_F_NOTIFY))
1660 cache->mfc_flags |= MFC_NOTIFY;
1661 err = ipmr_fill_mroute(skb, cache, rtm);
1662 read_unlock(&mrt_lock);
1663 return err;
1664 }
1665
1666 #ifdef CONFIG_PROC_FS
1667 /*
1668 * The /proc interfaces to multicast routing /proc/ip_mr_cache /proc/ip_mr_vif
1669 */
1670 struct ipmr_vif_iter {
1671 int ct;
1672 };
1673
ipmr_vif_seq_idx(struct ipmr_vif_iter * iter,loff_t pos)1674 static struct vif_device *ipmr_vif_seq_idx(struct ipmr_vif_iter *iter,
1675 loff_t pos)
1676 {
1677 for (iter->ct = 0; iter->ct < maxvif; ++iter->ct) {
1678 if (!VIF_EXISTS(iter->ct))
1679 continue;
1680 if (pos-- == 0)
1681 return &vif_table[iter->ct];
1682 }
1683 return NULL;
1684 }
1685
ipmr_vif_seq_start(struct seq_file * seq,loff_t * pos)1686 static void *ipmr_vif_seq_start(struct seq_file *seq, loff_t *pos)
1687 __acquires(mrt_lock)
1688 {
1689 read_lock(&mrt_lock);
1690 return *pos ? ipmr_vif_seq_idx(seq->private, *pos - 1)
1691 : SEQ_START_TOKEN;
1692 }
1693
ipmr_vif_seq_next(struct seq_file * seq,void * v,loff_t * pos)1694 static void *ipmr_vif_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1695 {
1696 struct ipmr_vif_iter *iter = seq->private;
1697
1698 ++*pos;
1699 if (v == SEQ_START_TOKEN)
1700 return ipmr_vif_seq_idx(iter, 0);
1701
1702 while (++iter->ct < maxvif) {
1703 if (!VIF_EXISTS(iter->ct))
1704 continue;
1705 return &vif_table[iter->ct];
1706 }
1707 return NULL;
1708 }
1709
ipmr_vif_seq_stop(struct seq_file * seq,void * v)1710 static void ipmr_vif_seq_stop(struct seq_file *seq, void *v)
1711 __releases(mrt_lock)
1712 {
1713 read_unlock(&mrt_lock);
1714 }
1715
ipmr_vif_seq_show(struct seq_file * seq,void * v)1716 static int ipmr_vif_seq_show(struct seq_file *seq, void *v)
1717 {
1718 if (v == SEQ_START_TOKEN) {
1719 seq_puts(seq,
1720 "Interface BytesIn PktsIn BytesOut PktsOut Flags Local Remote\n");
1721 } else {
1722 const struct vif_device *vif = v;
1723 const char *name = vif->dev ? vif->dev->name : "none";
1724
1725 seq_printf(seq,
1726 "%2Zd %-10s %8ld %7ld %8ld %7ld %05X %08X %08X\n",
1727 vif - vif_table,
1728 name, vif->bytes_in, vif->pkt_in,
1729 vif->bytes_out, vif->pkt_out,
1730 vif->flags, vif->local, vif->remote);
1731 }
1732 return 0;
1733 }
1734
1735 static const struct seq_operations ipmr_vif_seq_ops = {
1736 .start = ipmr_vif_seq_start,
1737 .next = ipmr_vif_seq_next,
1738 .stop = ipmr_vif_seq_stop,
1739 .show = ipmr_vif_seq_show,
1740 };
1741
ipmr_vif_open(struct inode * inode,struct file * file)1742 static int ipmr_vif_open(struct inode *inode, struct file *file)
1743 {
1744 return seq_open_private(file, &ipmr_vif_seq_ops,
1745 sizeof(struct ipmr_vif_iter));
1746 }
1747
1748 static const struct file_operations ipmr_vif_fops = {
1749 .owner = THIS_MODULE,
1750 .open = ipmr_vif_open,
1751 .read = seq_read,
1752 .llseek = seq_lseek,
1753 .release = seq_release_private,
1754 };
1755
1756 struct ipmr_mfc_iter {
1757 struct mfc_cache **cache;
1758 int ct;
1759 };
1760
1761
ipmr_mfc_seq_idx(struct ipmr_mfc_iter * it,loff_t pos)1762 static struct mfc_cache *ipmr_mfc_seq_idx(struct ipmr_mfc_iter *it, loff_t pos)
1763 {
1764 struct mfc_cache *mfc;
1765
1766 it->cache = mfc_cache_array;
1767 read_lock(&mrt_lock);
1768 for (it->ct = 0; it->ct < MFC_LINES; it->ct++)
1769 for (mfc = mfc_cache_array[it->ct]; mfc; mfc = mfc->next)
1770 if (pos-- == 0)
1771 return mfc;
1772 read_unlock(&mrt_lock);
1773
1774 it->cache = &mfc_unres_queue;
1775 spin_lock_bh(&mfc_unres_lock);
1776 for (mfc = mfc_unres_queue; mfc; mfc = mfc->next)
1777 if (pos-- == 0)
1778 return mfc;
1779 spin_unlock_bh(&mfc_unres_lock);
1780
1781 it->cache = NULL;
1782 return NULL;
1783 }
1784
1785
ipmr_mfc_seq_start(struct seq_file * seq,loff_t * pos)1786 static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos)
1787 {
1788 struct ipmr_mfc_iter *it = seq->private;
1789 it->cache = NULL;
1790 it->ct = 0;
1791 return *pos ? ipmr_mfc_seq_idx(seq->private, *pos - 1)
1792 : SEQ_START_TOKEN;
1793 }
1794
ipmr_mfc_seq_next(struct seq_file * seq,void * v,loff_t * pos)1795 static void *ipmr_mfc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1796 {
1797 struct mfc_cache *mfc = v;
1798 struct ipmr_mfc_iter *it = seq->private;
1799
1800 ++*pos;
1801
1802 if (v == SEQ_START_TOKEN)
1803 return ipmr_mfc_seq_idx(seq->private, 0);
1804
1805 if (mfc->next)
1806 return mfc->next;
1807
1808 if (it->cache == &mfc_unres_queue)
1809 goto end_of_list;
1810
1811 BUG_ON(it->cache != mfc_cache_array);
1812
1813 while (++it->ct < MFC_LINES) {
1814 mfc = mfc_cache_array[it->ct];
1815 if (mfc)
1816 return mfc;
1817 }
1818
1819 /* exhausted cache_array, show unresolved */
1820 read_unlock(&mrt_lock);
1821 it->cache = &mfc_unres_queue;
1822 it->ct = 0;
1823
1824 spin_lock_bh(&mfc_unres_lock);
1825 mfc = mfc_unres_queue;
1826 if (mfc)
1827 return mfc;
1828
1829 end_of_list:
1830 spin_unlock_bh(&mfc_unres_lock);
1831 it->cache = NULL;
1832
1833 return NULL;
1834 }
1835
ipmr_mfc_seq_stop(struct seq_file * seq,void * v)1836 static void ipmr_mfc_seq_stop(struct seq_file *seq, void *v)
1837 {
1838 struct ipmr_mfc_iter *it = seq->private;
1839
1840 if (it->cache == &mfc_unres_queue)
1841 spin_unlock_bh(&mfc_unres_lock);
1842 else if (it->cache == mfc_cache_array)
1843 read_unlock(&mrt_lock);
1844 }
1845
ipmr_mfc_seq_show(struct seq_file * seq,void * v)1846 static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
1847 {
1848 int n;
1849
1850 if (v == SEQ_START_TOKEN) {
1851 seq_puts(seq,
1852 "Group Origin Iif Pkts Bytes Wrong Oifs\n");
1853 } else {
1854 const struct mfc_cache *mfc = v;
1855 const struct ipmr_mfc_iter *it = seq->private;
1856
1857 seq_printf(seq, "%08lX %08lX %-3hd",
1858 (unsigned long) mfc->mfc_mcastgrp,
1859 (unsigned long) mfc->mfc_origin,
1860 mfc->mfc_parent);
1861
1862 if (it->cache != &mfc_unres_queue) {
1863 seq_printf(seq, " %8lu %8lu %8lu",
1864 mfc->mfc_un.res.pkt,
1865 mfc->mfc_un.res.bytes,
1866 mfc->mfc_un.res.wrong_if);
1867 for (n = mfc->mfc_un.res.minvif;
1868 n < mfc->mfc_un.res.maxvif; n++ ) {
1869 if (VIF_EXISTS(n)
1870 && mfc->mfc_un.res.ttls[n] < 255)
1871 seq_printf(seq,
1872 " %2d:%-3d",
1873 n, mfc->mfc_un.res.ttls[n]);
1874 }
1875 } else {
1876 /* unresolved mfc_caches don't contain
1877 * pkt, bytes and wrong_if values
1878 */
1879 seq_printf(seq, " %8lu %8lu %8lu", 0ul, 0ul, 0ul);
1880 }
1881 seq_putc(seq, '\n');
1882 }
1883 return 0;
1884 }
1885
1886 static const struct seq_operations ipmr_mfc_seq_ops = {
1887 .start = ipmr_mfc_seq_start,
1888 .next = ipmr_mfc_seq_next,
1889 .stop = ipmr_mfc_seq_stop,
1890 .show = ipmr_mfc_seq_show,
1891 };
1892
ipmr_mfc_open(struct inode * inode,struct file * file)1893 static int ipmr_mfc_open(struct inode *inode, struct file *file)
1894 {
1895 return seq_open_private(file, &ipmr_mfc_seq_ops,
1896 sizeof(struct ipmr_mfc_iter));
1897 }
1898
1899 static const struct file_operations ipmr_mfc_fops = {
1900 .owner = THIS_MODULE,
1901 .open = ipmr_mfc_open,
1902 .read = seq_read,
1903 .llseek = seq_lseek,
1904 .release = seq_release_private,
1905 };
1906 #endif
1907
1908 #ifdef CONFIG_IP_PIMSM_V2
1909 static struct net_protocol pim_protocol = {
1910 .handler = pim_rcv,
1911 };
1912 #endif
1913
1914
1915 /*
1916 * Setup for IP multicast routing
1917 */
1918
ip_mr_init(void)1919 int __init ip_mr_init(void)
1920 {
1921 int err;
1922
1923 mrt_cachep = kmem_cache_create("ip_mrt_cache",
1924 sizeof(struct mfc_cache),
1925 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
1926 NULL);
1927 if (!mrt_cachep)
1928 return -ENOMEM;
1929
1930 setup_timer(&ipmr_expire_timer, ipmr_expire_process, 0);
1931 err = register_netdevice_notifier(&ip_mr_notifier);
1932 if (err)
1933 goto reg_notif_fail;
1934 #ifdef CONFIG_PROC_FS
1935 err = -ENOMEM;
1936 if (!proc_net_fops_create(&init_net, "ip_mr_vif", 0, &ipmr_vif_fops))
1937 goto proc_vif_fail;
1938 if (!proc_net_fops_create(&init_net, "ip_mr_cache", 0, &ipmr_mfc_fops))
1939 goto proc_cache_fail;
1940 #endif
1941 return 0;
1942 #ifdef CONFIG_PROC_FS
1943 proc_cache_fail:
1944 proc_net_remove(&init_net, "ip_mr_vif");
1945 proc_vif_fail:
1946 unregister_netdevice_notifier(&ip_mr_notifier);
1947 #endif
1948 reg_notif_fail:
1949 del_timer(&ipmr_expire_timer);
1950 kmem_cache_destroy(mrt_cachep);
1951 return err;
1952 }
1953