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TOMOYO Linux Cross Reference
Linux/net/ipv4/ipmr.c

Version: ~ [ linux-5.2-rc5 ] ~ [ linux-5.1.12 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.53 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.128 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.182 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.182 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.68 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.39.4 ] ~ [ linux-2.6.38.8 ] ~ [ linux-2.6.37.6 ] ~ [ linux-2.6.36.4 ] ~ [ linux-2.6.35.14 ] ~ [ linux-2.6.34.15 ] ~ [ linux-2.6.33.20 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
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  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 requirement to work with older peers.
 26  *
 27  */
 28 
 29 #include <asm/uaccess.h>
 30 #include <linux/types.h>
 31 #include <linux/capability.h>
 32 #include <linux/errno.h>
 33 #include <linux/timer.h>
 34 #include <linux/mm.h>
 35 #include <linux/kernel.h>
 36 #include <linux/fcntl.h>
 37 #include <linux/stat.h>
 38 #include <linux/socket.h>
 39 #include <linux/in.h>
 40 #include <linux/inet.h>
 41 #include <linux/netdevice.h>
 42 #include <linux/inetdevice.h>
 43 #include <linux/igmp.h>
 44 #include <linux/proc_fs.h>
 45 #include <linux/seq_file.h>
 46 #include <linux/mroute.h>
 47 #include <linux/init.h>
 48 #include <linux/if_ether.h>
 49 #include <linux/slab.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 <linux/compat.h>
 63 #include <linux/export.h>
 64 #include <net/ip_tunnels.h>
 65 #include <net/checksum.h>
 66 #include <net/netlink.h>
 67 #include <net/fib_rules.h>
 68 #include <linux/netconf.h>
 69 
 70 #if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
 71 #define CONFIG_IP_PIMSM 1
 72 #endif
 73 
 74 struct mr_table {
 75         struct list_head        list;
 76 #ifdef CONFIG_NET_NS
 77         struct net              *net;
 78 #endif
 79         u32                     id;
 80         struct sock __rcu       *mroute_sk;
 81         struct timer_list       ipmr_expire_timer;
 82         struct list_head        mfc_unres_queue;
 83         struct list_head        mfc_cache_array[MFC_LINES];
 84         struct vif_device       vif_table[MAXVIFS];
 85         int                     maxvif;
 86         atomic_t                cache_resolve_queue_len;
 87         bool                    mroute_do_assert;
 88         bool                    mroute_do_pim;
 89 #if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
 90         int                     mroute_reg_vif_num;
 91 #endif
 92 };
 93 
 94 struct ipmr_rule {
 95         struct fib_rule         common;
 96 };
 97 
 98 struct ipmr_result {
 99         struct mr_table         *mrt;
100 };
101 
102 /* Big lock, protecting vif table, mrt cache and mroute socket state.
103  * Note that the changes are semaphored via rtnl_lock.
104  */
105 
106 static DEFINE_RWLOCK(mrt_lock);
107 
108 /*
109  *      Multicast router control variables
110  */
111 
112 #define VIF_EXISTS(_mrt, _idx) ((_mrt)->vif_table[_idx].dev != NULL)
113 
114 /* Special spinlock for queue of unresolved entries */
115 static DEFINE_SPINLOCK(mfc_unres_lock);
116 
117 /* We return to original Alan's scheme. Hash table of resolved
118  * entries is changed only in process context and protected
119  * with weak lock mrt_lock. Queue of unresolved entries is protected
120  * with strong spinlock mfc_unres_lock.
121  *
122  * In this case data path is free of exclusive locks at all.
123  */
124 
125 static struct kmem_cache *mrt_cachep __read_mostly;
126 
127 static struct mr_table *ipmr_new_table(struct net *net, u32 id);
128 static void ipmr_free_table(struct mr_table *mrt);
129 
130 static int ip_mr_forward(struct net *net, struct mr_table *mrt,
131                          struct sk_buff *skb, struct mfc_cache *cache,
132                          int local);
133 static int ipmr_cache_report(struct mr_table *mrt,
134                              struct sk_buff *pkt, vifi_t vifi, int assert);
135 static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
136                               struct mfc_cache *c, struct rtmsg *rtm);
137 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
138                                  int cmd);
139 static void mroute_clean_tables(struct mr_table *mrt);
140 static void ipmr_expire_process(unsigned long arg);
141 
142 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
143 #define ipmr_for_each_table(mrt, net) \
144         list_for_each_entry_rcu(mrt, &net->ipv4.mr_tables, list)
145 
146 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
147 {
148         struct mr_table *mrt;
149 
150         ipmr_for_each_table(mrt, net) {
151                 if (mrt->id == id)
152                         return mrt;
153         }
154         return NULL;
155 }
156 
157 static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
158                            struct mr_table **mrt)
159 {
160         struct ipmr_result res;
161         struct fib_lookup_arg arg = { .result = &res, };
162         int err;
163 
164         err = fib_rules_lookup(net->ipv4.mr_rules_ops,
165                                flowi4_to_flowi(flp4), 0, &arg);
166         if (err < 0)
167                 return err;
168         *mrt = res.mrt;
169         return 0;
170 }
171 
172 static int ipmr_rule_action(struct fib_rule *rule, struct flowi *flp,
173                             int flags, struct fib_lookup_arg *arg)
174 {
175         struct ipmr_result *res = arg->result;
176         struct mr_table *mrt;
177 
178         switch (rule->action) {
179         case FR_ACT_TO_TBL:
180                 break;
181         case FR_ACT_UNREACHABLE:
182                 return -ENETUNREACH;
183         case FR_ACT_PROHIBIT:
184                 return -EACCES;
185         case FR_ACT_BLACKHOLE:
186         default:
187                 return -EINVAL;
188         }
189 
190         mrt = ipmr_get_table(rule->fr_net, rule->table);
191         if (mrt == NULL)
192                 return -EAGAIN;
193         res->mrt = mrt;
194         return 0;
195 }
196 
197 static int ipmr_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
198 {
199         return 1;
200 }
201 
202 static const struct nla_policy ipmr_rule_policy[FRA_MAX + 1] = {
203         FRA_GENERIC_POLICY,
204 };
205 
206 static int ipmr_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
207                                struct fib_rule_hdr *frh, struct nlattr **tb)
208 {
209         return 0;
210 }
211 
212 static int ipmr_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
213                              struct nlattr **tb)
214 {
215         return 1;
216 }
217 
218 static int ipmr_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
219                           struct fib_rule_hdr *frh)
220 {
221         frh->dst_len = 0;
222         frh->src_len = 0;
223         frh->tos     = 0;
224         return 0;
225 }
226 
227 static const struct fib_rules_ops __net_initconst ipmr_rules_ops_template = {
228         .family         = RTNL_FAMILY_IPMR,
229         .rule_size      = sizeof(struct ipmr_rule),
230         .addr_size      = sizeof(u32),
231         .action         = ipmr_rule_action,
232         .match          = ipmr_rule_match,
233         .configure      = ipmr_rule_configure,
234         .compare        = ipmr_rule_compare,
235         .default_pref   = fib_default_rule_pref,
236         .fill           = ipmr_rule_fill,
237         .nlgroup        = RTNLGRP_IPV4_RULE,
238         .policy         = ipmr_rule_policy,
239         .owner          = THIS_MODULE,
240 };
241 
242 static int __net_init ipmr_rules_init(struct net *net)
243 {
244         struct fib_rules_ops *ops;
245         struct mr_table *mrt;
246         int err;
247 
248         ops = fib_rules_register(&ipmr_rules_ops_template, net);
249         if (IS_ERR(ops))
250                 return PTR_ERR(ops);
251 
252         INIT_LIST_HEAD(&net->ipv4.mr_tables);
253 
254         mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
255         if (mrt == NULL) {
256                 err = -ENOMEM;
257                 goto err1;
258         }
259 
260         err = fib_default_rule_add(ops, 0x7fff, RT_TABLE_DEFAULT, 0);
261         if (err < 0)
262                 goto err2;
263 
264         net->ipv4.mr_rules_ops = ops;
265         return 0;
266 
267 err2:
268         kfree(mrt);
269 err1:
270         fib_rules_unregister(ops);
271         return err;
272 }
273 
274 static void __net_exit ipmr_rules_exit(struct net *net)
275 {
276         struct mr_table *mrt, *next;
277 
278         list_for_each_entry_safe(mrt, next, &net->ipv4.mr_tables, list) {
279                 list_del(&mrt->list);
280                 ipmr_free_table(mrt);
281         }
282         fib_rules_unregister(net->ipv4.mr_rules_ops);
283 }
284 #else
285 #define ipmr_for_each_table(mrt, net) \
286         for (mrt = net->ipv4.mrt; mrt; mrt = NULL)
287 
288 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
289 {
290         return net->ipv4.mrt;
291 }
292 
293 static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
294                            struct mr_table **mrt)
295 {
296         *mrt = net->ipv4.mrt;
297         return 0;
298 }
299 
300 static int __net_init ipmr_rules_init(struct net *net)
301 {
302         net->ipv4.mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
303         return net->ipv4.mrt ? 0 : -ENOMEM;
304 }
305 
306 static void __net_exit ipmr_rules_exit(struct net *net)
307 {
308         ipmr_free_table(net->ipv4.mrt);
309 }
310 #endif
311 
312 static struct mr_table *ipmr_new_table(struct net *net, u32 id)
313 {
314         struct mr_table *mrt;
315         unsigned int i;
316 
317         mrt = ipmr_get_table(net, id);
318         if (mrt != NULL)
319                 return mrt;
320 
321         mrt = kzalloc(sizeof(*mrt), GFP_KERNEL);
322         if (mrt == NULL)
323                 return NULL;
324         write_pnet(&mrt->net, net);
325         mrt->id = id;
326 
327         /* Forwarding cache */
328         for (i = 0; i < MFC_LINES; i++)
329                 INIT_LIST_HEAD(&mrt->mfc_cache_array[i]);
330 
331         INIT_LIST_HEAD(&mrt->mfc_unres_queue);
332 
333         setup_timer(&mrt->ipmr_expire_timer, ipmr_expire_process,
334                     (unsigned long)mrt);
335 
336 #ifdef CONFIG_IP_PIMSM
337         mrt->mroute_reg_vif_num = -1;
338 #endif
339 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
340         list_add_tail_rcu(&mrt->list, &net->ipv4.mr_tables);
341 #endif
342         return mrt;
343 }
344 
345 static void ipmr_free_table(struct mr_table *mrt)
346 {
347         del_timer_sync(&mrt->ipmr_expire_timer);
348         mroute_clean_tables(mrt);
349         kfree(mrt);
350 }
351 
352 /* Service routines creating virtual interfaces: DVMRP tunnels and PIMREG */
353 
354 static void ipmr_del_tunnel(struct net_device *dev, struct vifctl *v)
355 {
356         struct net *net = dev_net(dev);
357 
358         dev_close(dev);
359 
360         dev = __dev_get_by_name(net, "tunl0");
361         if (dev) {
362                 const struct net_device_ops *ops = dev->netdev_ops;
363                 struct ifreq ifr;
364                 struct ip_tunnel_parm p;
365 
366                 memset(&p, 0, sizeof(p));
367                 p.iph.daddr = v->vifc_rmt_addr.s_addr;
368                 p.iph.saddr = v->vifc_lcl_addr.s_addr;
369                 p.iph.version = 4;
370                 p.iph.ihl = 5;
371                 p.iph.protocol = IPPROTO_IPIP;
372                 sprintf(p.name, "dvmrp%d", v->vifc_vifi);
373                 ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
374 
375                 if (ops->ndo_do_ioctl) {
376                         mm_segment_t oldfs = get_fs();
377 
378                         set_fs(KERNEL_DS);
379                         ops->ndo_do_ioctl(dev, &ifr, SIOCDELTUNNEL);
380                         set_fs(oldfs);
381                 }
382         }
383 }
384 
385 static
386 struct net_device *ipmr_new_tunnel(struct net *net, struct vifctl *v)
387 {
388         struct net_device  *dev;
389 
390         dev = __dev_get_by_name(net, "tunl0");
391 
392         if (dev) {
393                 const struct net_device_ops *ops = dev->netdev_ops;
394                 int err;
395                 struct ifreq ifr;
396                 struct ip_tunnel_parm p;
397                 struct in_device  *in_dev;
398 
399                 memset(&p, 0, sizeof(p));
400                 p.iph.daddr = v->vifc_rmt_addr.s_addr;
401                 p.iph.saddr = v->vifc_lcl_addr.s_addr;
402                 p.iph.version = 4;
403                 p.iph.ihl = 5;
404                 p.iph.protocol = IPPROTO_IPIP;
405                 sprintf(p.name, "dvmrp%d", v->vifc_vifi);
406                 ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
407 
408                 if (ops->ndo_do_ioctl) {
409                         mm_segment_t oldfs = get_fs();
410 
411                         set_fs(KERNEL_DS);
412                         err = ops->ndo_do_ioctl(dev, &ifr, SIOCADDTUNNEL);
413                         set_fs(oldfs);
414                 } else {
415                         err = -EOPNOTSUPP;
416                 }
417                 dev = NULL;
418 
419                 if (err == 0 &&
420                     (dev = __dev_get_by_name(net, p.name)) != NULL) {
421                         dev->flags |= IFF_MULTICAST;
422 
423                         in_dev = __in_dev_get_rtnl(dev);
424                         if (in_dev == NULL)
425                                 goto failure;
426 
427                         ipv4_devconf_setall(in_dev);
428                         IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
429 
430                         if (dev_open(dev))
431                                 goto failure;
432                         dev_hold(dev);
433                 }
434         }
435         return dev;
436 
437 failure:
438         /* allow the register to be completed before unregistering. */
439         rtnl_unlock();
440         rtnl_lock();
441 
442         unregister_netdevice(dev);
443         return NULL;
444 }
445 
446 #ifdef CONFIG_IP_PIMSM
447 
448 static netdev_tx_t reg_vif_xmit(struct sk_buff *skb, struct net_device *dev)
449 {
450         struct net *net = dev_net(dev);
451         struct mr_table *mrt;
452         struct flowi4 fl4 = {
453                 .flowi4_oif     = dev->ifindex,
454                 .flowi4_iif     = skb->skb_iif,
455                 .flowi4_mark    = skb->mark,
456         };
457         int err;
458 
459         err = ipmr_fib_lookup(net, &fl4, &mrt);
460         if (err < 0) {
461                 kfree_skb(skb);
462                 return err;
463         }
464 
465         read_lock(&mrt_lock);
466         dev->stats.tx_bytes += skb->len;
467         dev->stats.tx_packets++;
468         ipmr_cache_report(mrt, skb, mrt->mroute_reg_vif_num, IGMPMSG_WHOLEPKT);
469         read_unlock(&mrt_lock);
470         kfree_skb(skb);
471         return NETDEV_TX_OK;
472 }
473 
474 static const struct net_device_ops reg_vif_netdev_ops = {
475         .ndo_start_xmit = reg_vif_xmit,
476 };
477 
478 static void reg_vif_setup(struct net_device *dev)
479 {
480         dev->type               = ARPHRD_PIMREG;
481         dev->mtu                = ETH_DATA_LEN - sizeof(struct iphdr) - 8;
482         dev->flags              = IFF_NOARP;
483         dev->netdev_ops         = &reg_vif_netdev_ops,
484         dev->destructor         = free_netdev;
485         dev->features           |= NETIF_F_NETNS_LOCAL;
486 }
487 
488 static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
489 {
490         struct net_device *dev;
491         struct in_device *in_dev;
492         char name[IFNAMSIZ];
493 
494         if (mrt->id == RT_TABLE_DEFAULT)
495                 sprintf(name, "pimreg");
496         else
497                 sprintf(name, "pimreg%u", mrt->id);
498 
499         dev = alloc_netdev(0, name, reg_vif_setup);
500 
501         if (dev == NULL)
502                 return NULL;
503 
504         dev_net_set(dev, net);
505 
506         if (register_netdevice(dev)) {
507                 free_netdev(dev);
508                 return NULL;
509         }
510         dev->iflink = 0;
511 
512         rcu_read_lock();
513         in_dev = __in_dev_get_rcu(dev);
514         if (!in_dev) {
515                 rcu_read_unlock();
516                 goto failure;
517         }
518 
519         ipv4_devconf_setall(in_dev);
520         IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
521         rcu_read_unlock();
522 
523         if (dev_open(dev))
524                 goto failure;
525 
526         dev_hold(dev);
527 
528         return dev;
529 
530 failure:
531         /* allow the register to be completed before unregistering. */
532         rtnl_unlock();
533         rtnl_lock();
534 
535         unregister_netdevice(dev);
536         return NULL;
537 }
538 #endif
539 
540 /**
541  *      vif_delete - Delete a VIF entry
542  *      @notify: Set to 1, if the caller is a notifier_call
543  */
544 
545 static int vif_delete(struct mr_table *mrt, int vifi, int notify,
546                       struct list_head *head)
547 {
548         struct vif_device *v;
549         struct net_device *dev;
550         struct in_device *in_dev;
551 
552         if (vifi < 0 || vifi >= mrt->maxvif)
553                 return -EADDRNOTAVAIL;
554 
555         v = &mrt->vif_table[vifi];
556 
557         write_lock_bh(&mrt_lock);
558         dev = v->dev;
559         v->dev = NULL;
560 
561         if (!dev) {
562                 write_unlock_bh(&mrt_lock);
563                 return -EADDRNOTAVAIL;
564         }
565 
566 #ifdef CONFIG_IP_PIMSM
567         if (vifi == mrt->mroute_reg_vif_num)
568                 mrt->mroute_reg_vif_num = -1;
569 #endif
570 
571         if (vifi + 1 == mrt->maxvif) {
572                 int tmp;
573 
574                 for (tmp = vifi - 1; tmp >= 0; tmp--) {
575                         if (VIF_EXISTS(mrt, tmp))
576                                 break;
577                 }
578                 mrt->maxvif = tmp+1;
579         }
580 
581         write_unlock_bh(&mrt_lock);
582 
583         dev_set_allmulti(dev, -1);
584 
585         in_dev = __in_dev_get_rtnl(dev);
586         if (in_dev) {
587                 IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)--;
588                 inet_netconf_notify_devconf(dev_net(dev),
589                                             NETCONFA_MC_FORWARDING,
590                                             dev->ifindex, &in_dev->cnf);
591                 ip_rt_multicast_event(in_dev);
592         }
593 
594         if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER) && !notify)
595                 unregister_netdevice_queue(dev, head);
596 
597         dev_put(dev);
598         return 0;
599 }
600 
601 static void ipmr_cache_free_rcu(struct rcu_head *head)
602 {
603         struct mfc_cache *c = container_of(head, struct mfc_cache, rcu);
604 
605         kmem_cache_free(mrt_cachep, c);
606 }
607 
608 static inline void ipmr_cache_free(struct mfc_cache *c)
609 {
610         call_rcu(&c->rcu, ipmr_cache_free_rcu);
611 }
612 
613 /* Destroy an unresolved cache entry, killing queued skbs
614  * and reporting error to netlink readers.
615  */
616 
617 static void ipmr_destroy_unres(struct mr_table *mrt, struct mfc_cache *c)
618 {
619         struct net *net = read_pnet(&mrt->net);
620         struct sk_buff *skb;
621         struct nlmsgerr *e;
622 
623         atomic_dec(&mrt->cache_resolve_queue_len);
624 
625         while ((skb = skb_dequeue(&c->mfc_un.unres.unresolved))) {
626                 if (ip_hdr(skb)->version == 0) {
627                         struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr));
628                         nlh->nlmsg_type = NLMSG_ERROR;
629                         nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
630                         skb_trim(skb, nlh->nlmsg_len);
631                         e = nlmsg_data(nlh);
632                         e->error = -ETIMEDOUT;
633                         memset(&e->msg, 0, sizeof(e->msg));
634 
635                         rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
636                 } else {
637                         kfree_skb(skb);
638                 }
639         }
640 
641         ipmr_cache_free(c);
642 }
643 
644 
645 /* Timer process for the unresolved queue. */
646 
647 static void ipmr_expire_process(unsigned long arg)
648 {
649         struct mr_table *mrt = (struct mr_table *)arg;
650         unsigned long now;
651         unsigned long expires;
652         struct mfc_cache *c, *next;
653 
654         if (!spin_trylock(&mfc_unres_lock)) {
655                 mod_timer(&mrt->ipmr_expire_timer, jiffies+HZ/10);
656                 return;
657         }
658 
659         if (list_empty(&mrt->mfc_unres_queue))
660                 goto out;
661 
662         now = jiffies;
663         expires = 10*HZ;
664 
665         list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
666                 if (time_after(c->mfc_un.unres.expires, now)) {
667                         unsigned long interval = c->mfc_un.unres.expires - now;
668                         if (interval < expires)
669                                 expires = interval;
670                         continue;
671                 }
672 
673                 list_del(&c->list);
674                 mroute_netlink_event(mrt, c, RTM_DELROUTE);
675                 ipmr_destroy_unres(mrt, c);
676         }
677 
678         if (!list_empty(&mrt->mfc_unres_queue))
679                 mod_timer(&mrt->ipmr_expire_timer, jiffies + expires);
680 
681 out:
682         spin_unlock(&mfc_unres_lock);
683 }
684 
685 /* Fill oifs list. It is called under write locked mrt_lock. */
686 
687 static void ipmr_update_thresholds(struct mr_table *mrt, struct mfc_cache *cache,
688                                    unsigned char *ttls)
689 {
690         int vifi;
691 
692         cache->mfc_un.res.minvif = MAXVIFS;
693         cache->mfc_un.res.maxvif = 0;
694         memset(cache->mfc_un.res.ttls, 255, MAXVIFS);
695 
696         for (vifi = 0; vifi < mrt->maxvif; vifi++) {
697                 if (VIF_EXISTS(mrt, vifi) &&
698                     ttls[vifi] && ttls[vifi] < 255) {
699                         cache->mfc_un.res.ttls[vifi] = ttls[vifi];
700                         if (cache->mfc_un.res.minvif > vifi)
701                                 cache->mfc_un.res.minvif = vifi;
702                         if (cache->mfc_un.res.maxvif <= vifi)
703                                 cache->mfc_un.res.maxvif = vifi + 1;
704                 }
705         }
706 }
707 
708 static int vif_add(struct net *net, struct mr_table *mrt,
709                    struct vifctl *vifc, int mrtsock)
710 {
711         int vifi = vifc->vifc_vifi;
712         struct vif_device *v = &mrt->vif_table[vifi];
713         struct net_device *dev;
714         struct in_device *in_dev;
715         int err;
716 
717         /* Is vif busy ? */
718         if (VIF_EXISTS(mrt, vifi))
719                 return -EADDRINUSE;
720 
721         switch (vifc->vifc_flags) {
722 #ifdef CONFIG_IP_PIMSM
723         case VIFF_REGISTER:
724                 /*
725                  * Special Purpose VIF in PIM
726                  * All the packets will be sent to the daemon
727                  */
728                 if (mrt->mroute_reg_vif_num >= 0)
729                         return -EADDRINUSE;
730                 dev = ipmr_reg_vif(net, mrt);
731                 if (!dev)
732                         return -ENOBUFS;
733                 err = dev_set_allmulti(dev, 1);
734                 if (err) {
735                         unregister_netdevice(dev);
736                         dev_put(dev);
737                         return err;
738                 }
739                 break;
740 #endif
741         case VIFF_TUNNEL:
742                 dev = ipmr_new_tunnel(net, vifc);
743                 if (!dev)
744                         return -ENOBUFS;
745                 err = dev_set_allmulti(dev, 1);
746                 if (err) {
747                         ipmr_del_tunnel(dev, vifc);
748                         dev_put(dev);
749                         return err;
750                 }
751                 break;
752 
753         case VIFF_USE_IFINDEX:
754         case 0:
755                 if (vifc->vifc_flags == VIFF_USE_IFINDEX) {
756                         dev = dev_get_by_index(net, vifc->vifc_lcl_ifindex);
757                         if (dev && __in_dev_get_rtnl(dev) == NULL) {
758                                 dev_put(dev);
759                                 return -EADDRNOTAVAIL;
760                         }
761                 } else {
762                         dev = ip_dev_find(net, vifc->vifc_lcl_addr.s_addr);
763                 }
764                 if (!dev)
765                         return -EADDRNOTAVAIL;
766                 err = dev_set_allmulti(dev, 1);
767                 if (err) {
768                         dev_put(dev);
769                         return err;
770                 }
771                 break;
772         default:
773                 return -EINVAL;
774         }
775 
776         in_dev = __in_dev_get_rtnl(dev);
777         if (!in_dev) {
778                 dev_put(dev);
779                 return -EADDRNOTAVAIL;
780         }
781         IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)++;
782         inet_netconf_notify_devconf(net, NETCONFA_MC_FORWARDING, dev->ifindex,
783                                     &in_dev->cnf);
784         ip_rt_multicast_event(in_dev);
785 
786         /* Fill in the VIF structures */
787 
788         v->rate_limit = vifc->vifc_rate_limit;
789         v->local = vifc->vifc_lcl_addr.s_addr;
790         v->remote = vifc->vifc_rmt_addr.s_addr;
791         v->flags = vifc->vifc_flags;
792         if (!mrtsock)
793                 v->flags |= VIFF_STATIC;
794         v->threshold = vifc->vifc_threshold;
795         v->bytes_in = 0;
796         v->bytes_out = 0;
797         v->pkt_in = 0;
798         v->pkt_out = 0;
799         v->link = dev->ifindex;
800         if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER))
801                 v->link = dev->iflink;
802 
803         /* And finish update writing critical data */
804         write_lock_bh(&mrt_lock);
805         v->dev = dev;
806 #ifdef CONFIG_IP_PIMSM
807         if (v->flags & VIFF_REGISTER)
808                 mrt->mroute_reg_vif_num = vifi;
809 #endif
810         if (vifi+1 > mrt->maxvif)
811                 mrt->maxvif = vifi+1;
812         write_unlock_bh(&mrt_lock);
813         return 0;
814 }
815 
816 /* called with rcu_read_lock() */
817 static struct mfc_cache *ipmr_cache_find(struct mr_table *mrt,
818                                          __be32 origin,
819                                          __be32 mcastgrp)
820 {
821         int line = MFC_HASH(mcastgrp, origin);
822         struct mfc_cache *c;
823 
824         list_for_each_entry_rcu(c, &mrt->mfc_cache_array[line], list) {
825                 if (c->mfc_origin == origin && c->mfc_mcastgrp == mcastgrp)
826                         return c;
827         }
828         return NULL;
829 }
830 
831 /* Look for a (*,*,oif) entry */
832 static struct mfc_cache *ipmr_cache_find_any_parent(struct mr_table *mrt,
833                                                     int vifi)
834 {
835         int line = MFC_HASH(htonl(INADDR_ANY), htonl(INADDR_ANY));
836         struct mfc_cache *c;
837 
838         list_for_each_entry_rcu(c, &mrt->mfc_cache_array[line], list)
839                 if (c->mfc_origin == htonl(INADDR_ANY) &&
840                     c->mfc_mcastgrp == htonl(INADDR_ANY) &&
841                     c->mfc_un.res.ttls[vifi] < 255)
842                         return c;
843 
844         return NULL;
845 }
846 
847 /* Look for a (*,G) entry */
848 static struct mfc_cache *ipmr_cache_find_any(struct mr_table *mrt,
849                                              __be32 mcastgrp, int vifi)
850 {
851         int line = MFC_HASH(mcastgrp, htonl(INADDR_ANY));
852         struct mfc_cache *c, *proxy;
853 
854         if (mcastgrp == htonl(INADDR_ANY))
855                 goto skip;
856 
857         list_for_each_entry_rcu(c, &mrt->mfc_cache_array[line], list)
858                 if (c->mfc_origin == htonl(INADDR_ANY) &&
859                     c->mfc_mcastgrp == mcastgrp) {
860                         if (c->mfc_un.res.ttls[vifi] < 255)
861                                 return c;
862 
863                         /* It's ok if the vifi is part of the static tree */
864                         proxy = ipmr_cache_find_any_parent(mrt,
865                                                            c->mfc_parent);
866                         if (proxy && proxy->mfc_un.res.ttls[vifi] < 255)
867                                 return c;
868                 }
869 
870 skip:
871         return ipmr_cache_find_any_parent(mrt, vifi);
872 }
873 
874 /*
875  *      Allocate a multicast cache entry
876  */
877 static struct mfc_cache *ipmr_cache_alloc(void)
878 {
879         struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_KERNEL);
880 
881         if (c)
882                 c->mfc_un.res.minvif = MAXVIFS;
883         return c;
884 }
885 
886 static struct mfc_cache *ipmr_cache_alloc_unres(void)
887 {
888         struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_ATOMIC);
889 
890         if (c) {
891                 skb_queue_head_init(&c->mfc_un.unres.unresolved);
892                 c->mfc_un.unres.expires = jiffies + 10*HZ;
893         }
894         return c;
895 }
896 
897 /*
898  *      A cache entry has gone into a resolved state from queued
899  */
900 
901 static void ipmr_cache_resolve(struct net *net, struct mr_table *mrt,
902                                struct mfc_cache *uc, struct mfc_cache *c)
903 {
904         struct sk_buff *skb;
905         struct nlmsgerr *e;
906 
907         /* Play the pending entries through our router */
908 
909         while ((skb = __skb_dequeue(&uc->mfc_un.unres.unresolved))) {
910                 if (ip_hdr(skb)->version == 0) {
911                         struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr));
912 
913                         if (__ipmr_fill_mroute(mrt, skb, c, nlmsg_data(nlh)) > 0) {
914                                 nlh->nlmsg_len = skb_tail_pointer(skb) -
915                                                  (u8 *)nlh;
916                         } else {
917                                 nlh->nlmsg_type = NLMSG_ERROR;
918                                 nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
919                                 skb_trim(skb, nlh->nlmsg_len);
920                                 e = nlmsg_data(nlh);
921                                 e->error = -EMSGSIZE;
922                                 memset(&e->msg, 0, sizeof(e->msg));
923                         }
924 
925                         rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
926                 } else {
927                         ip_mr_forward(net, mrt, skb, c, 0);
928                 }
929         }
930 }
931 
932 /*
933  *      Bounce a cache query up to mrouted. We could use netlink for this but mrouted
934  *      expects the following bizarre scheme.
935  *
936  *      Called under mrt_lock.
937  */
938 
939 static int ipmr_cache_report(struct mr_table *mrt,
940                              struct sk_buff *pkt, vifi_t vifi, int assert)
941 {
942         struct sk_buff *skb;
943         const int ihl = ip_hdrlen(pkt);
944         struct igmphdr *igmp;
945         struct igmpmsg *msg;
946         struct sock *mroute_sk;
947         int ret;
948 
949 #ifdef CONFIG_IP_PIMSM
950         if (assert == IGMPMSG_WHOLEPKT)
951                 skb = skb_realloc_headroom(pkt, sizeof(struct iphdr));
952         else
953 #endif
954                 skb = alloc_skb(128, GFP_ATOMIC);
955 
956         if (!skb)
957                 return -ENOBUFS;
958 
959 #ifdef CONFIG_IP_PIMSM
960         if (assert == IGMPMSG_WHOLEPKT) {
961                 /* Ugly, but we have no choice with this interface.
962                  * Duplicate old header, fix ihl, length etc.
963                  * And all this only to mangle msg->im_msgtype and
964                  * to set msg->im_mbz to "mbz" :-)
965                  */
966                 skb_push(skb, sizeof(struct iphdr));
967                 skb_reset_network_header(skb);
968                 skb_reset_transport_header(skb);
969                 msg = (struct igmpmsg *)skb_network_header(skb);
970                 memcpy(msg, skb_network_header(pkt), sizeof(struct iphdr));
971                 msg->im_msgtype = IGMPMSG_WHOLEPKT;
972                 msg->im_mbz = 0;
973                 msg->im_vif = mrt->mroute_reg_vif_num;
974                 ip_hdr(skb)->ihl = sizeof(struct iphdr) >> 2;
975                 ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(pkt)->tot_len) +
976                                              sizeof(struct iphdr));
977         } else
978 #endif
979         {
980 
981         /* Copy the IP header */
982 
983         skb_set_network_header(skb, skb->len);
984         skb_put(skb, ihl);
985         skb_copy_to_linear_data(skb, pkt->data, ihl);
986         ip_hdr(skb)->protocol = 0;      /* Flag to the kernel this is a route add */
987         msg = (struct igmpmsg *)skb_network_header(skb);
988         msg->im_vif = vifi;
989         skb_dst_set(skb, dst_clone(skb_dst(pkt)));
990 
991         /* Add our header */
992 
993         igmp = (struct igmphdr *)skb_put(skb, sizeof(struct igmphdr));
994         igmp->type      =
995         msg->im_msgtype = assert;
996         igmp->code      = 0;
997         ip_hdr(skb)->tot_len = htons(skb->len);         /* Fix the length */
998         skb->transport_header = skb->network_header;
999         }
1000 
1001         rcu_read_lock();
1002         mroute_sk = rcu_dereference(mrt->mroute_sk);
1003         if (mroute_sk == NULL) {
1004                 rcu_read_unlock();
1005                 kfree_skb(skb);
1006                 return -EINVAL;
1007         }
1008 
1009         /* Deliver to mrouted */
1010 
1011         ret = sock_queue_rcv_skb(mroute_sk, skb);
1012         rcu_read_unlock();
1013         if (ret < 0) {
1014                 net_warn_ratelimited("mroute: pending queue full, dropping entries\n");
1015                 kfree_skb(skb);
1016         }
1017 
1018         return ret;
1019 }
1020 
1021 /*
1022  *      Queue a packet for resolution. It gets locked cache entry!
1023  */
1024 
1025 static int
1026 ipmr_cache_unresolved(struct mr_table *mrt, vifi_t vifi, struct sk_buff *skb)
1027 {
1028         bool found = false;
1029         int err;
1030         struct mfc_cache *c;
1031         const struct iphdr *iph = ip_hdr(skb);
1032 
1033         spin_lock_bh(&mfc_unres_lock);
1034         list_for_each_entry(c, &mrt->mfc_unres_queue, list) {
1035                 if (c->mfc_mcastgrp == iph->daddr &&
1036                     c->mfc_origin == iph->saddr) {
1037                         found = true;
1038                         break;
1039                 }
1040         }
1041 
1042         if (!found) {
1043                 /* Create a new entry if allowable */
1044 
1045                 if (atomic_read(&mrt->cache_resolve_queue_len) >= 10 ||
1046                     (c = ipmr_cache_alloc_unres()) == NULL) {
1047                         spin_unlock_bh(&mfc_unres_lock);
1048 
1049                         kfree_skb(skb);
1050                         return -ENOBUFS;
1051                 }
1052 
1053                 /* Fill in the new cache entry */
1054 
1055                 c->mfc_parent   = -1;
1056                 c->mfc_origin   = iph->saddr;
1057                 c->mfc_mcastgrp = iph->daddr;
1058 
1059                 /* Reflect first query at mrouted. */
1060 
1061                 err = ipmr_cache_report(mrt, skb, vifi, IGMPMSG_NOCACHE);
1062                 if (err < 0) {
1063                         /* If the report failed throw the cache entry
1064                            out - Brad Parker
1065                          */
1066                         spin_unlock_bh(&mfc_unres_lock);
1067 
1068                         ipmr_cache_free(c);
1069                         kfree_skb(skb);
1070                         return err;
1071                 }
1072 
1073                 atomic_inc(&mrt->cache_resolve_queue_len);
1074                 list_add(&c->list, &mrt->mfc_unres_queue);
1075                 mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1076 
1077                 if (atomic_read(&mrt->cache_resolve_queue_len) == 1)
1078                         mod_timer(&mrt->ipmr_expire_timer, c->mfc_un.unres.expires);
1079         }
1080 
1081         /* See if we can append the packet */
1082 
1083         if (c->mfc_un.unres.unresolved.qlen > 3) {
1084                 kfree_skb(skb);
1085                 err = -ENOBUFS;
1086         } else {
1087                 skb_queue_tail(&c->mfc_un.unres.unresolved, skb);
1088                 err = 0;
1089         }
1090 
1091         spin_unlock_bh(&mfc_unres_lock);
1092         return err;
1093 }
1094 
1095 /*
1096  *      MFC cache manipulation by user space mroute daemon
1097  */
1098 
1099 static int ipmr_mfc_delete(struct mr_table *mrt, struct mfcctl *mfc, int parent)
1100 {
1101         int line;
1102         struct mfc_cache *c, *next;
1103 
1104         line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
1105 
1106         list_for_each_entry_safe(c, next, &mrt->mfc_cache_array[line], list) {
1107                 if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
1108                     c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr &&
1109                     (parent == -1 || parent == c->mfc_parent)) {
1110                         list_del_rcu(&c->list);
1111                         mroute_netlink_event(mrt, c, RTM_DELROUTE);
1112                         ipmr_cache_free(c);
1113                         return 0;
1114                 }
1115         }
1116         return -ENOENT;
1117 }
1118 
1119 static int ipmr_mfc_add(struct net *net, struct mr_table *mrt,
1120                         struct mfcctl *mfc, int mrtsock, int parent)
1121 {
1122         bool found = false;
1123         int line;
1124         struct mfc_cache *uc, *c;
1125 
1126         if (mfc->mfcc_parent >= MAXVIFS)
1127                 return -ENFILE;
1128 
1129         line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
1130 
1131         list_for_each_entry(c, &mrt->mfc_cache_array[line], list) {
1132                 if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
1133                     c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr &&
1134                     (parent == -1 || parent == c->mfc_parent)) {
1135                         found = true;
1136                         break;
1137                 }
1138         }
1139 
1140         if (found) {
1141                 write_lock_bh(&mrt_lock);
1142                 c->mfc_parent = mfc->mfcc_parent;
1143                 ipmr_update_thresholds(mrt, c, mfc->mfcc_ttls);
1144                 if (!mrtsock)
1145                         c->mfc_flags |= MFC_STATIC;
1146                 write_unlock_bh(&mrt_lock);
1147                 mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1148                 return 0;
1149         }
1150 
1151         if (mfc->mfcc_mcastgrp.s_addr != htonl(INADDR_ANY) &&
1152             !ipv4_is_multicast(mfc->mfcc_mcastgrp.s_addr))
1153                 return -EINVAL;
1154 
1155         c = ipmr_cache_alloc();
1156         if (c == NULL)
1157                 return -ENOMEM;
1158 
1159         c->mfc_origin = mfc->mfcc_origin.s_addr;
1160         c->mfc_mcastgrp = mfc->mfcc_mcastgrp.s_addr;
1161         c->mfc_parent = mfc->mfcc_parent;
1162         ipmr_update_thresholds(mrt, c, mfc->mfcc_ttls);
1163         if (!mrtsock)
1164                 c->mfc_flags |= MFC_STATIC;
1165 
1166         list_add_rcu(&c->list, &mrt->mfc_cache_array[line]);
1167 
1168         /*
1169          *      Check to see if we resolved a queued list. If so we
1170          *      need to send on the frames and tidy up.
1171          */
1172         found = false;
1173         spin_lock_bh(&mfc_unres_lock);
1174         list_for_each_entry(uc, &mrt->mfc_unres_queue, list) {
1175                 if (uc->mfc_origin == c->mfc_origin &&
1176                     uc->mfc_mcastgrp == c->mfc_mcastgrp) {
1177                         list_del(&uc->list);
1178                         atomic_dec(&mrt->cache_resolve_queue_len);
1179                         found = true;
1180                         break;
1181                 }
1182         }
1183         if (list_empty(&mrt->mfc_unres_queue))
1184                 del_timer(&mrt->ipmr_expire_timer);
1185         spin_unlock_bh(&mfc_unres_lock);
1186 
1187         if (found) {
1188                 ipmr_cache_resolve(net, mrt, uc, c);
1189                 ipmr_cache_free(uc);
1190         }
1191         mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1192         return 0;
1193 }
1194 
1195 /*
1196  *      Close the multicast socket, and clear the vif tables etc
1197  */
1198 
1199 static void mroute_clean_tables(struct mr_table *mrt)
1200 {
1201         int i;
1202         LIST_HEAD(list);
1203         struct mfc_cache *c, *next;
1204 
1205         /* Shut down all active vif entries */
1206 
1207         for (i = 0; i < mrt->maxvif; i++) {
1208                 if (!(mrt->vif_table[i].flags & VIFF_STATIC))
1209                         vif_delete(mrt, i, 0, &list);
1210         }
1211         unregister_netdevice_many(&list);
1212 
1213         /* Wipe the cache */
1214 
1215         for (i = 0; i < MFC_LINES; i++) {
1216                 list_for_each_entry_safe(c, next, &mrt->mfc_cache_array[i], list) {
1217                         if (c->mfc_flags & MFC_STATIC)
1218                                 continue;
1219                         list_del_rcu(&c->list);
1220                         mroute_netlink_event(mrt, c, RTM_DELROUTE);
1221                         ipmr_cache_free(c);
1222                 }
1223         }
1224 
1225         if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
1226                 spin_lock_bh(&mfc_unres_lock);
1227                 list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
1228                         list_del(&c->list);
1229                         mroute_netlink_event(mrt, c, RTM_DELROUTE);
1230                         ipmr_destroy_unres(mrt, c);
1231                 }
1232                 spin_unlock_bh(&mfc_unres_lock);
1233         }
1234 }
1235 
1236 /* called from ip_ra_control(), before an RCU grace period,
1237  * we dont need to call synchronize_rcu() here
1238  */
1239 static void mrtsock_destruct(struct sock *sk)
1240 {
1241         struct net *net = sock_net(sk);
1242         struct mr_table *mrt;
1243 
1244         rtnl_lock();
1245         ipmr_for_each_table(mrt, net) {
1246                 if (sk == rtnl_dereference(mrt->mroute_sk)) {
1247                         IPV4_DEVCONF_ALL(net, MC_FORWARDING)--;
1248                         inet_netconf_notify_devconf(net, NETCONFA_MC_FORWARDING,
1249                                                     NETCONFA_IFINDEX_ALL,
1250                                                     net->ipv4.devconf_all);
1251                         RCU_INIT_POINTER(mrt->mroute_sk, NULL);
1252                         mroute_clean_tables(mrt);
1253                 }
1254         }
1255         rtnl_unlock();
1256 }
1257 
1258 /*
1259  *      Socket options and virtual interface manipulation. The whole
1260  *      virtual interface system is a complete heap, but unfortunately
1261  *      that's how BSD mrouted happens to think. Maybe one day with a proper
1262  *      MOSPF/PIM router set up we can clean this up.
1263  */
1264 
1265 int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, unsigned int optlen)
1266 {
1267         int ret, parent = 0;
1268         struct vifctl vif;
1269         struct mfcctl mfc;
1270         struct net *net = sock_net(sk);
1271         struct mr_table *mrt;
1272 
1273         if (sk->sk_type != SOCK_RAW ||
1274             inet_sk(sk)->inet_num != IPPROTO_IGMP)
1275                 return -EOPNOTSUPP;
1276 
1277         mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1278         if (mrt == NULL)
1279                 return -ENOENT;
1280 
1281         if (optname != MRT_INIT) {
1282                 if (sk != rcu_access_pointer(mrt->mroute_sk) &&
1283                     !ns_capable(net->user_ns, CAP_NET_ADMIN))
1284                         return -EACCES;
1285         }
1286 
1287         switch (optname) {
1288         case MRT_INIT:
1289                 if (optlen != sizeof(int))
1290                         return -EINVAL;
1291 
1292                 rtnl_lock();
1293                 if (rtnl_dereference(mrt->mroute_sk)) {
1294                         rtnl_unlock();
1295                         return -EADDRINUSE;
1296                 }
1297 
1298                 ret = ip_ra_control(sk, 1, mrtsock_destruct);
1299                 if (ret == 0) {
1300                         rcu_assign_pointer(mrt->mroute_sk, sk);
1301                         IPV4_DEVCONF_ALL(net, MC_FORWARDING)++;
1302                         inet_netconf_notify_devconf(net, NETCONFA_MC_FORWARDING,
1303                                                     NETCONFA_IFINDEX_ALL,
1304                                                     net->ipv4.devconf_all);
1305                 }
1306                 rtnl_unlock();
1307                 return ret;
1308         case MRT_DONE:
1309                 if (sk != rcu_access_pointer(mrt->mroute_sk))
1310                         return -EACCES;
1311                 return ip_ra_control(sk, 0, NULL);
1312         case MRT_ADD_VIF:
1313         case MRT_DEL_VIF:
1314                 if (optlen != sizeof(vif))
1315                         return -EINVAL;
1316                 if (copy_from_user(&vif, optval, sizeof(vif)))
1317                         return -EFAULT;
1318                 if (vif.vifc_vifi >= MAXVIFS)
1319                         return -ENFILE;
1320                 rtnl_lock();
1321                 if (optname == MRT_ADD_VIF) {
1322                         ret = vif_add(net, mrt, &vif,
1323                                       sk == rtnl_dereference(mrt->mroute_sk));
1324                 } else {
1325                         ret = vif_delete(mrt, vif.vifc_vifi, 0, NULL);
1326                 }
1327                 rtnl_unlock();
1328                 return ret;
1329 
1330                 /*
1331                  *      Manipulate the forwarding caches. These live
1332                  *      in a sort of kernel/user symbiosis.
1333                  */
1334         case MRT_ADD_MFC:
1335         case MRT_DEL_MFC:
1336                 parent = -1;
1337         case MRT_ADD_MFC_PROXY:
1338         case MRT_DEL_MFC_PROXY:
1339                 if (optlen != sizeof(mfc))
1340                         return -EINVAL;
1341                 if (copy_from_user(&mfc, optval, sizeof(mfc)))
1342                         return -EFAULT;
1343                 if (parent == 0)
1344                         parent = mfc.mfcc_parent;
1345                 rtnl_lock();
1346                 if (optname == MRT_DEL_MFC || optname == MRT_DEL_MFC_PROXY)
1347                         ret = ipmr_mfc_delete(mrt, &mfc, parent);
1348                 else
1349                         ret = ipmr_mfc_add(net, mrt, &mfc,
1350                                            sk == rtnl_dereference(mrt->mroute_sk),
1351                                            parent);
1352                 rtnl_unlock();
1353                 return ret;
1354                 /*
1355                  *      Control PIM assert.
1356                  */
1357         case MRT_ASSERT:
1358         {
1359                 int v;
1360                 if (optlen != sizeof(v))
1361                         return -EINVAL;
1362                 if (get_user(v, (int __user *)optval))
1363                         return -EFAULT;
1364                 mrt->mroute_do_assert = v;
1365                 return 0;
1366         }
1367 #ifdef CONFIG_IP_PIMSM
1368         case MRT_PIM:
1369         {
1370                 int v;
1371 
1372                 if (optlen != sizeof(v))
1373                         return -EINVAL;
1374                 if (get_user(v, (int __user *)optval))
1375                         return -EFAULT;
1376                 v = !!v;
1377 
1378                 rtnl_lock();
1379                 ret = 0;
1380                 if (v != mrt->mroute_do_pim) {
1381                         mrt->mroute_do_pim = v;
1382                         mrt->mroute_do_assert = v;
1383                 }
1384                 rtnl_unlock();
1385                 return ret;
1386         }
1387 #endif
1388 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
1389         case MRT_TABLE:
1390         {
1391                 u32 v;
1392 
1393                 if (optlen != sizeof(u32))
1394                         return -EINVAL;
1395                 if (get_user(v, (u32 __user *)optval))
1396                         return -EFAULT;
1397 
1398                 /* "pimreg%u" should not exceed 16 bytes (IFNAMSIZ) */
1399                 if (v != RT_TABLE_DEFAULT && v >= 1000000000)
1400                         return -EINVAL;
1401 
1402                 rtnl_lock();
1403                 ret = 0;
1404                 if (sk == rtnl_dereference(mrt->mroute_sk)) {
1405                         ret = -EBUSY;
1406                 } else {
1407                         if (!ipmr_new_table(net, v))
1408                                 ret = -ENOMEM;
1409                         else
1410                                 raw_sk(sk)->ipmr_table = v;
1411                 }
1412                 rtnl_unlock();
1413                 return ret;
1414         }
1415 #endif
1416         /*
1417          *      Spurious command, or MRT_VERSION which you cannot
1418          *      set.
1419          */
1420         default:
1421                 return -ENOPROTOOPT;
1422         }
1423 }
1424 
1425 /*
1426  *      Getsock opt support for the multicast routing system.
1427  */
1428 
1429 int ip_mroute_getsockopt(struct sock *sk, int optname, char __user *optval, int __user *optlen)
1430 {
1431         int olr;
1432         int val;
1433         struct net *net = sock_net(sk);
1434         struct mr_table *mrt;
1435 
1436         if (sk->sk_type != SOCK_RAW ||
1437             inet_sk(sk)->inet_num != IPPROTO_IGMP)
1438                 return -EOPNOTSUPP;
1439 
1440         mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1441         if (mrt == NULL)
1442                 return -ENOENT;
1443 
1444         if (optname != MRT_VERSION &&
1445 #ifdef CONFIG_IP_PIMSM
1446            optname != MRT_PIM &&
1447 #endif
1448            optname != MRT_ASSERT)
1449                 return -ENOPROTOOPT;
1450 
1451         if (get_user(olr, optlen))
1452                 return -EFAULT;
1453 
1454         olr = min_t(unsigned int, olr, sizeof(int));
1455         if (olr < 0)
1456                 return -EINVAL;
1457 
1458         if (put_user(olr, optlen))
1459                 return -EFAULT;
1460         if (optname == MRT_VERSION)
1461                 val = 0x0305;
1462 #ifdef CONFIG_IP_PIMSM
1463         else if (optname == MRT_PIM)
1464                 val = mrt->mroute_do_pim;
1465 #endif
1466         else
1467                 val = mrt->mroute_do_assert;
1468         if (copy_to_user(optval, &val, olr))
1469                 return -EFAULT;
1470         return 0;
1471 }
1472 
1473 /*
1474  *      The IP multicast ioctl support routines.
1475  */
1476 
1477 int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg)
1478 {
1479         struct sioc_sg_req sr;
1480         struct sioc_vif_req vr;
1481         struct vif_device *vif;
1482         struct mfc_cache *c;
1483         struct net *net = sock_net(sk);
1484         struct mr_table *mrt;
1485 
1486         mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1487         if (mrt == NULL)
1488                 return -ENOENT;
1489 
1490         switch (cmd) {
1491         case SIOCGETVIFCNT:
1492                 if (copy_from_user(&vr, arg, sizeof(vr)))
1493                         return -EFAULT;
1494                 if (vr.vifi >= mrt->maxvif)
1495                         return -EINVAL;
1496                 read_lock(&mrt_lock);
1497                 vif = &mrt->vif_table[vr.vifi];
1498                 if (VIF_EXISTS(mrt, vr.vifi)) {
1499                         vr.icount = vif->pkt_in;
1500                         vr.ocount = vif->pkt_out;
1501                         vr.ibytes = vif->bytes_in;
1502                         vr.obytes = vif->bytes_out;
1503                         read_unlock(&mrt_lock);
1504 
1505                         if (copy_to_user(arg, &vr, sizeof(vr)))
1506                                 return -EFAULT;
1507                         return 0;
1508                 }
1509                 read_unlock(&mrt_lock);
1510                 return -EADDRNOTAVAIL;
1511         case SIOCGETSGCNT:
1512                 if (copy_from_user(&sr, arg, sizeof(sr)))
1513                         return -EFAULT;
1514 
1515                 rcu_read_lock();
1516                 c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1517                 if (c) {
1518                         sr.pktcnt = c->mfc_un.res.pkt;
1519                         sr.bytecnt = c->mfc_un.res.bytes;
1520                         sr.wrong_if = c->mfc_un.res.wrong_if;
1521                         rcu_read_unlock();
1522 
1523                         if (copy_to_user(arg, &sr, sizeof(sr)))
1524                                 return -EFAULT;
1525                         return 0;
1526                 }
1527                 rcu_read_unlock();
1528                 return -EADDRNOTAVAIL;
1529         default:
1530                 return -ENOIOCTLCMD;
1531         }
1532 }
1533 
1534 #ifdef CONFIG_COMPAT
1535 struct compat_sioc_sg_req {
1536         struct in_addr src;
1537         struct in_addr grp;
1538         compat_ulong_t pktcnt;
1539         compat_ulong_t bytecnt;
1540         compat_ulong_t wrong_if;
1541 };
1542 
1543 struct compat_sioc_vif_req {
1544         vifi_t  vifi;           /* Which iface */
1545         compat_ulong_t icount;
1546         compat_ulong_t ocount;
1547         compat_ulong_t ibytes;
1548         compat_ulong_t obytes;
1549 };
1550 
1551 int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
1552 {
1553         struct compat_sioc_sg_req sr;
1554         struct compat_sioc_vif_req vr;
1555         struct vif_device *vif;
1556         struct mfc_cache *c;
1557         struct net *net = sock_net(sk);
1558         struct mr_table *mrt;
1559 
1560         mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1561         if (mrt == NULL)
1562                 return -ENOENT;
1563 
1564         switch (cmd) {
1565         case SIOCGETVIFCNT:
1566                 if (copy_from_user(&vr, arg, sizeof(vr)))
1567                         return -EFAULT;
1568                 if (vr.vifi >= mrt->maxvif)
1569                         return -EINVAL;
1570                 read_lock(&mrt_lock);
1571                 vif = &mrt->vif_table[vr.vifi];
1572                 if (VIF_EXISTS(mrt, vr.vifi)) {
1573                         vr.icount = vif->pkt_in;
1574                         vr.ocount = vif->pkt_out;
1575                         vr.ibytes = vif->bytes_in;
1576                         vr.obytes = vif->bytes_out;
1577                         read_unlock(&mrt_lock);
1578 
1579                         if (copy_to_user(arg, &vr, sizeof(vr)))
1580                                 return -EFAULT;
1581                         return 0;
1582                 }
1583                 read_unlock(&mrt_lock);
1584                 return -EADDRNOTAVAIL;
1585         case SIOCGETSGCNT:
1586                 if (copy_from_user(&sr, arg, sizeof(sr)))
1587                         return -EFAULT;
1588 
1589                 rcu_read_lock();
1590                 c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1591                 if (c) {
1592                         sr.pktcnt = c->mfc_un.res.pkt;
1593                         sr.bytecnt = c->mfc_un.res.bytes;
1594                         sr.wrong_if = c->mfc_un.res.wrong_if;
1595                         rcu_read_unlock();
1596 
1597                         if (copy_to_user(arg, &sr, sizeof(sr)))
1598                                 return -EFAULT;
1599                         return 0;
1600                 }
1601                 rcu_read_unlock();
1602                 return -EADDRNOTAVAIL;
1603         default:
1604                 return -ENOIOCTLCMD;
1605         }
1606 }
1607 #endif
1608 
1609 
1610 static int ipmr_device_event(struct notifier_block *this, unsigned long event, void *ptr)
1611 {
1612         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1613         struct net *net = dev_net(dev);
1614         struct mr_table *mrt;
1615         struct vif_device *v;
1616         int ct;
1617 
1618         if (event != NETDEV_UNREGISTER)
1619                 return NOTIFY_DONE;
1620 
1621         ipmr_for_each_table(mrt, net) {
1622                 v = &mrt->vif_table[0];
1623                 for (ct = 0; ct < mrt->maxvif; ct++, v++) {
1624                         if (v->dev == dev)
1625                                 vif_delete(mrt, ct, 1, NULL);
1626                 }
1627         }
1628         return NOTIFY_DONE;
1629 }
1630 
1631 
1632 static struct notifier_block ip_mr_notifier = {
1633         .notifier_call = ipmr_device_event,
1634 };
1635 
1636 /*
1637  *      Encapsulate a packet by attaching a valid IPIP header to it.
1638  *      This avoids tunnel drivers and other mess and gives us the speed so
1639  *      important for multicast video.
1640  */
1641 
1642 static void ip_encap(struct sk_buff *skb, __be32 saddr, __be32 daddr)
1643 {
1644         struct iphdr *iph;
1645         const struct iphdr *old_iph = ip_hdr(skb);
1646 
1647         skb_push(skb, sizeof(struct iphdr));
1648         skb->transport_header = skb->network_header;
1649         skb_reset_network_header(skb);
1650         iph = ip_hdr(skb);
1651 
1652         iph->version    =       4;
1653         iph->tos        =       old_iph->tos;
1654         iph->ttl        =       old_iph->ttl;
1655         iph->frag_off   =       0;
1656         iph->daddr      =       daddr;
1657         iph->saddr      =       saddr;
1658         iph->protocol   =       IPPROTO_IPIP;
1659         iph->ihl        =       5;
1660         iph->tot_len    =       htons(skb->len);
1661         ip_select_ident(skb, skb_dst(skb), NULL);
1662         ip_send_check(iph);
1663 
1664         memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1665         nf_reset(skb);
1666 }
1667 
1668 static inline int ipmr_forward_finish(struct sk_buff *skb)
1669 {
1670         struct ip_options *opt = &(IPCB(skb)->opt);
1671 
1672         IP_INC_STATS_BH(dev_net(skb_dst(skb)->dev), IPSTATS_MIB_OUTFORWDATAGRAMS);
1673         IP_ADD_STATS_BH(dev_net(skb_dst(skb)->dev), IPSTATS_MIB_OUTOCTETS, skb->len);
1674 
1675         if (unlikely(opt->optlen))
1676                 ip_forward_options(skb);
1677 
1678         return dst_output(skb);
1679 }
1680 
1681 /*
1682  *      Processing handlers for ipmr_forward
1683  */
1684 
1685 static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt,
1686                             struct sk_buff *skb, struct mfc_cache *c, int vifi)
1687 {
1688         const struct iphdr *iph = ip_hdr(skb);
1689         struct vif_device *vif = &mrt->vif_table[vifi];
1690         struct net_device *dev;
1691         struct rtable *rt;
1692         struct flowi4 fl4;
1693         int    encap = 0;
1694 
1695         if (vif->dev == NULL)
1696                 goto out_free;
1697 
1698 #ifdef CONFIG_IP_PIMSM
1699         if (vif->flags & VIFF_REGISTER) {
1700                 vif->pkt_out++;
1701                 vif->bytes_out += skb->len;
1702                 vif->dev->stats.tx_bytes += skb->len;
1703                 vif->dev->stats.tx_packets++;
1704                 ipmr_cache_report(mrt, skb, vifi, IGMPMSG_WHOLEPKT);
1705                 goto out_free;
1706         }
1707 #endif
1708 
1709         if (vif->flags & VIFF_TUNNEL) {
1710                 rt = ip_route_output_ports(net, &fl4, NULL,
1711                                            vif->remote, vif->local,
1712                                            0, 0,
1713                                            IPPROTO_IPIP,
1714                                            RT_TOS(iph->tos), vif->link);
1715                 if (IS_ERR(rt))
1716                         goto out_free;
1717                 encap = sizeof(struct iphdr);
1718         } else {
1719                 rt = ip_route_output_ports(net, &fl4, NULL, iph->daddr, 0,
1720                                            0, 0,
1721                                            IPPROTO_IPIP,
1722                                            RT_TOS(iph->tos), vif->link);
1723                 if (IS_ERR(rt))
1724                         goto out_free;
1725         }
1726 
1727         dev = rt->dst.dev;
1728 
1729         if (skb->len+encap > dst_mtu(&rt->dst) && (ntohs(iph->frag_off) & IP_DF)) {
1730                 /* Do not fragment multicasts. Alas, IPv4 does not
1731                  * allow to send ICMP, so that packets will disappear
1732                  * to blackhole.
1733                  */
1734 
1735                 IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_FRAGFAILS);
1736                 ip_rt_put(rt);
1737                 goto out_free;
1738         }
1739 
1740         encap += LL_RESERVED_SPACE(dev) + rt->dst.header_len;
1741 
1742         if (skb_cow(skb, encap)) {
1743                 ip_rt_put(rt);
1744                 goto out_free;
1745         }
1746 
1747         vif->pkt_out++;
1748         vif->bytes_out += skb->len;
1749 
1750         skb_dst_drop(skb);
1751         skb_dst_set(skb, &rt->dst);
1752         ip_decrease_ttl(ip_hdr(skb));
1753 
1754         /* FIXME: forward and output firewalls used to be called here.
1755          * What do we do with netfilter? -- RR
1756          */
1757         if (vif->flags & VIFF_TUNNEL) {
1758                 ip_encap(skb, vif->local, vif->remote);
1759                 /* FIXME: extra output firewall step used to be here. --RR */
1760                 vif->dev->stats.tx_packets++;
1761                 vif->dev->stats.tx_bytes += skb->len;
1762         }
1763 
1764         IPCB(skb)->flags |= IPSKB_FORWARDED;
1765 
1766         /*
1767          * RFC1584 teaches, that DVMRP/PIM router must deliver packets locally
1768          * not only before forwarding, but after forwarding on all output
1769          * interfaces. It is clear, if mrouter runs a multicasting
1770          * program, it should receive packets not depending to what interface
1771          * program is joined.
1772          * If we will not make it, the program will have to join on all
1773          * interfaces. On the other hand, multihoming host (or router, but
1774          * not mrouter) cannot join to more than one interface - it will
1775          * result in receiving multiple packets.
1776          */
1777         NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD, skb, skb->dev, dev,
1778                 ipmr_forward_finish);
1779         return;
1780 
1781 out_free:
1782         kfree_skb(skb);
1783 }
1784 
1785 static int ipmr_find_vif(struct mr_table *mrt, struct net_device *dev)
1786 {
1787         int ct;
1788 
1789         for (ct = mrt->maxvif-1; ct >= 0; ct--) {
1790                 if (mrt->vif_table[ct].dev == dev)
1791                         break;
1792         }
1793         return ct;
1794 }
1795 
1796 /* "local" means that we should preserve one skb (for local delivery) */
1797 
1798 static int ip_mr_forward(struct net *net, struct mr_table *mrt,
1799                          struct sk_buff *skb, struct mfc_cache *cache,
1800                          int local)
1801 {
1802         int psend = -1;
1803         int vif, ct;
1804         int true_vifi = ipmr_find_vif(mrt, skb->dev);
1805 
1806         vif = cache->mfc_parent;
1807         cache->mfc_un.res.pkt++;
1808         cache->mfc_un.res.bytes += skb->len;
1809 
1810         if (cache->mfc_origin == htonl(INADDR_ANY) && true_vifi >= 0) {
1811                 struct mfc_cache *cache_proxy;
1812 
1813                 /* For an (*,G) entry, we only check that the incomming
1814                  * interface is part of the static tree.
1815                  */
1816                 cache_proxy = ipmr_cache_find_any_parent(mrt, vif);
1817                 if (cache_proxy &&
1818                     cache_proxy->mfc_un.res.ttls[true_vifi] < 255)
1819                         goto forward;
1820         }
1821 
1822         /*
1823          * Wrong interface: drop packet and (maybe) send PIM assert.
1824          */
1825         if (mrt->vif_table[vif].dev != skb->dev) {
1826                 if (rt_is_output_route(skb_rtable(skb))) {
1827                         /* It is our own packet, looped back.
1828                          * Very complicated situation...
1829                          *
1830                          * The best workaround until routing daemons will be
1831                          * fixed is not to redistribute packet, if it was
1832                          * send through wrong interface. It means, that
1833                          * multicast applications WILL NOT work for
1834                          * (S,G), which have default multicast route pointing
1835                          * to wrong oif. In any case, it is not a good
1836                          * idea to use multicasting applications on router.
1837                          */
1838                         goto dont_forward;
1839                 }
1840 
1841                 cache->mfc_un.res.wrong_if++;
1842 
1843                 if (true_vifi >= 0 && mrt->mroute_do_assert &&
1844                     /* pimsm uses asserts, when switching from RPT to SPT,
1845                      * so that we cannot check that packet arrived on an oif.
1846                      * It is bad, but otherwise we would need to move pretty
1847                      * large chunk of pimd to kernel. Ough... --ANK
1848                      */
1849                     (mrt->mroute_do_pim ||
1850                      cache->mfc_un.res.ttls[true_vifi] < 255) &&
1851                     time_after(jiffies,
1852                                cache->mfc_un.res.last_assert + MFC_ASSERT_THRESH)) {
1853                         cache->mfc_un.res.last_assert = jiffies;
1854                         ipmr_cache_report(mrt, skb, true_vifi, IGMPMSG_WRONGVIF);
1855                 }
1856                 goto dont_forward;
1857         }
1858 
1859 forward:
1860         mrt->vif_table[vif].pkt_in++;
1861         mrt->vif_table[vif].bytes_in += skb->len;
1862 
1863         /*
1864          *      Forward the frame
1865          */
1866         if (cache->mfc_origin == htonl(INADDR_ANY) &&
1867             cache->mfc_mcastgrp == htonl(INADDR_ANY)) {
1868                 if (true_vifi >= 0 &&
1869                     true_vifi != cache->mfc_parent &&
1870                     ip_hdr(skb)->ttl >
1871                                 cache->mfc_un.res.ttls[cache->mfc_parent]) {
1872                         /* It's an (*,*) entry and the packet is not coming from
1873                          * the upstream: forward the packet to the upstream
1874                          * only.
1875                          */
1876                         psend = cache->mfc_parent;
1877                         goto last_forward;
1878                 }
1879                 goto dont_forward;
1880         }
1881         for (ct = cache->mfc_un.res.maxvif - 1;
1882              ct >= cache->mfc_un.res.minvif; ct--) {
1883                 /* For (*,G) entry, don't forward to the incoming interface */
1884                 if ((cache->mfc_origin != htonl(INADDR_ANY) ||
1885                      ct != true_vifi) &&
1886                     ip_hdr(skb)->ttl > cache->mfc_un.res.ttls[ct]) {
1887                         if (psend != -1) {
1888                                 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1889 
1890                                 if (skb2)
1891                                         ipmr_queue_xmit(net, mrt, skb2, cache,
1892                                                         psend);
1893                         }
1894                         psend = ct;
1895                 }
1896         }
1897 last_forward:
1898         if (psend != -1) {
1899                 if (local) {
1900                         struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1901 
1902                         if (skb2)
1903                                 ipmr_queue_xmit(net, mrt, skb2, cache, psend);
1904                 } else {
1905                         ipmr_queue_xmit(net, mrt, skb, cache, psend);
1906                         return 0;
1907                 }
1908         }
1909 
1910 dont_forward:
1911         if (!local)
1912                 kfree_skb(skb);
1913         return 0;
1914 }
1915 
1916 static struct mr_table *ipmr_rt_fib_lookup(struct net *net, struct sk_buff *skb)
1917 {
1918         struct rtable *rt = skb_rtable(skb);
1919         struct iphdr *iph = ip_hdr(skb);
1920         struct flowi4 fl4 = {
1921                 .daddr = iph->daddr,
1922                 .saddr = iph->saddr,
1923                 .flowi4_tos = RT_TOS(iph->tos),
1924                 .flowi4_oif = (rt_is_output_route(rt) ?
1925                                skb->dev->ifindex : 0),
1926                 .flowi4_iif = (rt_is_output_route(rt) ?
1927                                LOOPBACK_IFINDEX :
1928                                skb->dev->ifindex),
1929                 .flowi4_mark = skb->mark,
1930         };
1931         struct mr_table *mrt;
1932         int err;
1933 
1934         err = ipmr_fib_lookup(net, &fl4, &mrt);
1935         if (err)
1936                 return ERR_PTR(err);
1937         return mrt;
1938 }
1939 
1940 /*
1941  *      Multicast packets for forwarding arrive here
1942  *      Called with rcu_read_lock();
1943  */
1944 
1945 int ip_mr_input(struct sk_buff *skb)
1946 {
1947         struct mfc_cache *cache;
1948         struct net *net = dev_net(skb->dev);
1949         int local = skb_rtable(skb)->rt_flags & RTCF_LOCAL;
1950         struct mr_table *mrt;
1951 
1952         /* Packet is looped back after forward, it should not be
1953          * forwarded second time, but still can be delivered locally.
1954          */
1955         if (IPCB(skb)->flags & IPSKB_FORWARDED)
1956                 goto dont_forward;
1957 
1958         mrt = ipmr_rt_fib_lookup(net, skb);
1959         if (IS_ERR(mrt)) {
1960                 kfree_skb(skb);
1961                 return PTR_ERR(mrt);
1962         }
1963         if (!local) {
1964                 if (IPCB(skb)->opt.router_alert) {
1965                         if (ip_call_ra_chain(skb))
1966                                 return 0;
1967                 } else if (ip_hdr(skb)->protocol == IPPROTO_IGMP) {
1968                         /* IGMPv1 (and broken IGMPv2 implementations sort of
1969                          * Cisco IOS <= 11.2(8)) do not put router alert
1970                          * option to IGMP packets destined to routable
1971                          * groups. It is very bad, because it means
1972                          * that we can forward NO IGMP messages.
1973                          */
1974                         struct sock *mroute_sk;
1975 
1976                         mroute_sk = rcu_dereference(mrt->mroute_sk);
1977                         if (mroute_sk) {
1978                                 nf_reset(skb);
1979                                 raw_rcv(mroute_sk, skb);
1980                                 return 0;
1981                         }
1982                     }
1983         }
1984 
1985         /* already under rcu_read_lock() */
1986         cache = ipmr_cache_find(mrt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
1987         if (cache == NULL) {
1988                 int vif = ipmr_find_vif(mrt, skb->dev);
1989 
1990                 if (vif >= 0)
1991                         cache = ipmr_cache_find_any(mrt, ip_hdr(skb)->daddr,
1992                                                     vif);
1993         }
1994 
1995         /*
1996          *      No usable cache entry
1997          */
1998         if (cache == NULL) {
1999                 int vif;
2000 
2001                 if (local) {
2002                         struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
2003                         ip_local_deliver(skb);
2004                         if (skb2 == NULL)
2005                                 return -ENOBUFS;
2006                         skb = skb2;
2007                 }
2008 
2009                 read_lock(&mrt_lock);
2010                 vif = ipmr_find_vif(mrt, skb->dev);
2011                 if (vif >= 0) {
2012                         int err2 = ipmr_cache_unresolved(mrt, vif, skb);
2013                         read_unlock(&mrt_lock);
2014 
2015                         return err2;
2016                 }
2017                 read_unlock(&mrt_lock);
2018                 kfree_skb(skb);
2019                 return -ENODEV;
2020         }
2021 
2022         read_lock(&mrt_lock);
2023         ip_mr_forward(net, mrt, skb, cache, local);
2024         read_unlock(&mrt_lock);
2025 
2026         if (local)
2027                 return ip_local_deliver(skb);
2028 
2029         return 0;
2030 
2031 dont_forward:
2032         if (local)
2033                 return ip_local_deliver(skb);
2034         kfree_skb(skb);
2035         return 0;
2036 }
2037 
2038 #ifdef CONFIG_IP_PIMSM
2039 /* called with rcu_read_lock() */
2040 static int __pim_rcv(struct mr_table *mrt, struct sk_buff *skb,
2041                      unsigned int pimlen)
2042 {
2043         struct net_device *reg_dev = NULL;
2044         struct iphdr *encap;
2045 
2046         encap = (struct iphdr *)(skb_transport_header(skb) + pimlen);
2047         /*
2048          * Check that:
2049          * a. packet is really sent to a multicast group
2050          * b. packet is not a NULL-REGISTER
2051          * c. packet is not truncated
2052          */
2053         if (!ipv4_is_multicast(encap->daddr) ||
2054             encap->tot_len == 0 ||
2055             ntohs(encap->tot_len) + pimlen > skb->len)
2056                 return 1;
2057 
2058         read_lock(&mrt_lock);
2059         if (mrt->mroute_reg_vif_num >= 0)
2060                 reg_dev = mrt->vif_table[mrt->mroute_reg_vif_num].dev;
2061         read_unlock(&mrt_lock);
2062 
2063         if (reg_dev == NULL)
2064                 return 1;
2065 
2066         skb->mac_header = skb->network_header;
2067         skb_pull(skb, (u8 *)encap - skb->data);
2068         skb_reset_network_header(skb);
2069         skb->protocol = htons(ETH_P_IP);
2070         skb->ip_summed = CHECKSUM_NONE;
2071         skb->pkt_type = PACKET_HOST;
2072 
2073         skb_tunnel_rx(skb, reg_dev);
2074 
2075         netif_rx(skb);
2076 
2077         return NET_RX_SUCCESS;
2078 }
2079 #endif
2080 
2081 #ifdef CONFIG_IP_PIMSM_V1
2082 /*
2083  * Handle IGMP messages of PIMv1
2084  */
2085 
2086 int pim_rcv_v1(struct sk_buff *skb)
2087 {
2088         struct igmphdr *pim;
2089         struct net *net = dev_net(skb->dev);
2090         struct mr_table *mrt;
2091 
2092         if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
2093                 goto drop;
2094 
2095         pim = igmp_hdr(skb);
2096 
2097         mrt = ipmr_rt_fib_lookup(net, skb);
2098         if (IS_ERR(mrt))
2099                 goto drop;
2100         if (!mrt->mroute_do_pim ||
2101             pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER)
2102                 goto drop;
2103 
2104         if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2105 drop:
2106                 kfree_skb(skb);
2107         }
2108         return 0;
2109 }
2110 #endif
2111 
2112 #ifdef CONFIG_IP_PIMSM_V2
2113 static int pim_rcv(struct sk_buff *skb)
2114 {
2115         struct pimreghdr *pim;
2116         struct net *net = dev_net(skb->dev);
2117         struct mr_table *mrt;
2118 
2119         if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
2120                 goto drop;
2121 
2122         pim = (struct pimreghdr *)skb_transport_header(skb);
2123         if (pim->type != ((PIM_VERSION << 4) | (PIM_REGISTER)) ||
2124             (pim->flags & PIM_NULL_REGISTER) ||
2125             (ip_compute_csum((void *)pim, sizeof(*pim)) != 0 &&
2126              csum_fold(skb_checksum(skb, 0, skb->len, 0))))
2127                 goto drop;
2128 
2129         mrt = ipmr_rt_fib_lookup(net, skb);
2130         if (IS_ERR(mrt))
2131                 goto drop;
2132         if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2133 drop:
2134                 kfree_skb(skb);
2135         }
2136         return 0;
2137 }
2138 #endif
2139 
2140 static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2141                               struct mfc_cache *c, struct rtmsg *rtm)
2142 {
2143         int ct;
2144         struct rtnexthop *nhp;
2145         struct nlattr *mp_attr;
2146         struct rta_mfc_stats mfcs;
2147 
2148         /* If cache is unresolved, don't try to parse IIF and OIF */
2149         if (c->mfc_parent >= MAXVIFS)
2150                 return -ENOENT;
2151 
2152         if (VIF_EXISTS(mrt, c->mfc_parent) &&
2153             nla_put_u32(skb, RTA_IIF, mrt->vif_table[c->mfc_parent].dev->ifindex) < 0)
2154                 return -EMSGSIZE;
2155 
2156         if (!(mp_attr = nla_nest_start(skb, RTA_MULTIPATH)))
2157                 return -EMSGSIZE;
2158 
2159         for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) {
2160                 if (VIF_EXISTS(mrt, ct) && c->mfc_un.res.ttls[ct] < 255) {
2161                         if (!(nhp = nla_reserve_nohdr(skb, sizeof(*nhp)))) {
2162                                 nla_nest_cancel(skb, mp_attr);
2163                                 return -EMSGSIZE;
2164                         }
2165 
2166                         nhp->rtnh_flags = 0;
2167                         nhp->rtnh_hops = c->mfc_un.res.ttls[ct];
2168                         nhp->rtnh_ifindex = mrt->vif_table[ct].dev->ifindex;
2169                         nhp->rtnh_len = sizeof(*nhp);
2170                 }
2171         }
2172 
2173         nla_nest_end(skb, mp_attr);
2174 
2175         mfcs.mfcs_packets = c->mfc_un.res.pkt;
2176         mfcs.mfcs_bytes = c->mfc_un.res.bytes;
2177         mfcs.mfcs_wrong_if = c->mfc_un.res.wrong_if;
2178         if (nla_put(skb, RTA_MFC_STATS, sizeof(mfcs), &mfcs) < 0)
2179                 return -EMSGSIZE;
2180 
2181         rtm->rtm_type = RTN_MULTICAST;
2182         return 1;
2183 }
2184 
2185 int ipmr_get_route(struct net *net, struct sk_buff *skb,
2186                    __be32 saddr, __be32 daddr,
2187                    struct rtmsg *rtm, int nowait)
2188 {
2189         struct mfc_cache *cache;
2190         struct mr_table *mrt;
2191         int err;
2192 
2193         mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2194         if (mrt == NULL)
2195                 return -ENOENT;
2196 
2197         rcu_read_lock();
2198         cache = ipmr_cache_find(mrt, saddr, daddr);
2199         if (cache == NULL && skb->dev) {
2200                 int vif = ipmr_find_vif(mrt, skb->dev);
2201 
2202                 if (vif >= 0)
2203                         cache = ipmr_cache_find_any(mrt, daddr, vif);
2204         }
2205         if (cache == NULL) {
2206                 struct sk_buff *skb2;
2207                 struct iphdr *iph;
2208                 struct net_device *dev;
2209                 int vif = -1;
2210 
2211                 if (nowait) {
2212                         rcu_read_unlock();
2213                         return -EAGAIN;
2214                 }
2215 
2216                 dev = skb->dev;
2217                 read_lock(&mrt_lock);
2218                 if (dev)
2219                         vif = ipmr_find_vif(mrt, dev);
2220                 if (vif < 0) {
2221                         read_unlock(&mrt_lock);
2222                         rcu_read_unlock();
2223                         return -ENODEV;
2224                 }
2225                 skb2 = skb_clone(skb, GFP_ATOMIC);
2226                 if (!skb2) {
2227                         read_unlock(&mrt_lock);
2228                         rcu_read_unlock();
2229                         return -ENOMEM;
2230                 }
2231 
2232                 skb_push(skb2, sizeof(struct iphdr));
2233                 skb_reset_network_header(skb2);
2234                 iph = ip_hdr(skb2);
2235                 iph->ihl = sizeof(struct iphdr) >> 2;
2236                 iph->saddr = saddr;
2237                 iph->daddr = daddr;
2238                 iph->version = 0;
2239                 err = ipmr_cache_unresolved(mrt, vif, skb2);
2240                 read_unlock(&mrt_lock);
2241                 rcu_read_unlock();
2242                 return err;
2243         }
2244 
2245         read_lock(&mrt_lock);
2246         if (!nowait && (rtm->rtm_flags & RTM_F_NOTIFY))
2247                 cache->mfc_flags |= MFC_NOTIFY;
2248         err = __ipmr_fill_mroute(mrt, skb, cache, rtm);
2249         read_unlock(&mrt_lock);
2250         rcu_read_unlock();
2251         return err;
2252 }
2253 
2254 static int ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2255                             u32 portid, u32 seq, struct mfc_cache *c, int cmd)
2256 {
2257         struct nlmsghdr *nlh;
2258         struct rtmsg *rtm;
2259         int err;
2260 
2261         nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rtm), NLM_F_MULTI);
2262         if (nlh == NULL)
2263                 return -EMSGSIZE;
2264 
2265         rtm = nlmsg_data(nlh);
2266         rtm->rtm_family   = RTNL_FAMILY_IPMR;
2267         rtm->rtm_dst_len  = 32;
2268         rtm->rtm_src_len  = 32;
2269         rtm->rtm_tos      = 0;
2270         rtm->rtm_table    = mrt->id;
2271         if (nla_put_u32(skb, RTA_TABLE, mrt->id))
2272                 goto nla_put_failure;
2273         rtm->rtm_type     = RTN_MULTICAST;
2274         rtm->rtm_scope    = RT_SCOPE_UNIVERSE;
2275         if (c->mfc_flags & MFC_STATIC)
2276                 rtm->rtm_protocol = RTPROT_STATIC;
2277         else
2278                 rtm->rtm_protocol = RTPROT_MROUTED;
2279         rtm->rtm_flags    = 0;
2280 
2281         if (nla_put_be32(skb, RTA_SRC, c->mfc_origin) ||
2282             nla_put_be32(skb, RTA_DST, c->mfc_mcastgrp))
2283                 goto nla_put_failure;
2284         err = __ipmr_fill_mroute(mrt, skb, c, rtm);
2285         /* do not break the dump if cache is unresolved */
2286         if (err < 0 && err != -ENOENT)
2287                 goto nla_put_failure;
2288 
2289         return nlmsg_end(skb, nlh);
2290 
2291 nla_put_failure:
2292         nlmsg_cancel(skb, nlh);
2293         return -EMSGSIZE;
2294 }
2295 
2296 static size_t mroute_msgsize(bool unresolved, int maxvif)
2297 {
2298         size_t len =
2299                 NLMSG_ALIGN(sizeof(struct rtmsg))
2300                 + nla_total_size(4)     /* RTA_TABLE */
2301                 + nla_total_size(4)     /* RTA_SRC */
2302                 + nla_total_size(4)     /* RTA_DST */
2303                 ;
2304 
2305         if (!unresolved)
2306                 len = len
2307                       + nla_total_size(4)       /* RTA_IIF */
2308                       + nla_total_size(0)       /* RTA_MULTIPATH */
2309                       + maxvif * NLA_ALIGN(sizeof(struct rtnexthop))
2310                                                 /* RTA_MFC_STATS */
2311                       + nla_total_size(sizeof(struct rta_mfc_stats))
2312                 ;
2313 
2314         return len;
2315 }
2316 
2317 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
2318                                  int cmd)
2319 {
2320         struct net *net = read_pnet(&mrt->net);
2321         struct sk_buff *skb;
2322         int err = -ENOBUFS;
2323 
2324         skb = nlmsg_new(mroute_msgsize(mfc->mfc_parent >= MAXVIFS, mrt->maxvif),
2325                         GFP_ATOMIC);
2326         if (skb == NULL)
2327                 goto errout;
2328 
2329         err = ipmr_fill_mroute(mrt, skb, 0, 0, mfc, cmd);
2330         if (err < 0)
2331                 goto errout;
2332 
2333         rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MROUTE, NULL, GFP_ATOMIC);
2334         return;
2335 
2336 errout:
2337         kfree_skb(skb);
2338         if (err < 0)
2339                 rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE, err);
2340 }
2341 
2342 static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
2343 {
2344         struct net *net = sock_net(skb->sk);
2345         struct mr_table *mrt;
2346         struct mfc_cache *mfc;
2347         unsigned int t = 0, s_t;
2348         unsigned int h = 0, s_h;
2349         unsigned int e = 0, s_e;
2350 
2351         s_t = cb->args[0];
2352         s_h = cb->args[1];
2353         s_e = cb->args[2];
2354 
2355         rcu_read_lock();
2356         ipmr_for_each_table(mrt, net) {
2357                 if (t < s_t)
2358                         goto next_table;
2359                 if (t > s_t)
2360                         s_h = 0;
2361                 for (h = s_h; h < MFC_LINES; h++) {
2362                         list_for_each_entry_rcu(mfc, &mrt->mfc_cache_array[h], list) {
2363                                 if (e < s_e)
2364                                         goto next_entry;
2365                                 if (ipmr_fill_mroute(mrt, skb,
2366                                                      NETLINK_CB(cb->skb).portid,
2367                                                      cb->nlh->nlmsg_seq,
2368                                                      mfc, RTM_NEWROUTE) < 0)
2369                                         goto done;
2370 next_entry:
2371                                 e++;
2372                         }
2373                         e = s_e = 0;
2374                 }
2375                 spin_lock_bh(&mfc_unres_lock);
2376                 list_for_each_entry(mfc, &mrt->mfc_unres_queue, list) {
2377                         if (e < s_e)
2378                                 goto next_entry2;
2379                         if (ipmr_fill_mroute(mrt, skb,
2380                                              NETLINK_CB(cb->skb).portid,
2381                                              cb->nlh->nlmsg_seq,
2382                                              mfc, RTM_NEWROUTE) < 0) {
2383                                 spin_unlock_bh(&mfc_unres_lock);
2384                                 goto done;
2385                         }
2386 next_entry2:
2387                         e++;
2388                 }
2389                 spin_unlock_bh(&mfc_unres_lock);
2390                 e = s_e = 0;
2391                 s_h = 0;
2392 next_table:
2393                 t++;
2394         }
2395 done:
2396         rcu_read_unlock();
2397 
2398         cb->args[2] = e;
2399         cb->args[1] = h;
2400         cb->args[0] = t;
2401 
2402         return skb->len;
2403 }
2404 
2405 #ifdef CONFIG_PROC_FS
2406 /*
2407  *      The /proc interfaces to multicast routing :
2408  *      /proc/net/ip_mr_cache & /proc/net/ip_mr_vif
2409  */
2410 struct ipmr_vif_iter {
2411         struct seq_net_private p;
2412         struct mr_table *mrt;
2413         int ct;
2414 };
2415 
2416 static struct vif_device *ipmr_vif_seq_idx(struct net *net,
2417                                            struct ipmr_vif_iter *iter,
2418                                            loff_t pos)
2419 {
2420         struct mr_table *mrt = iter->mrt;
2421 
2422         for (iter->ct = 0; iter->ct < mrt->maxvif; ++iter->ct) {
2423                 if (!VIF_EXISTS(mrt, iter->ct))
2424                         continue;
2425                 if (pos-- == 0)
2426                         return &mrt->vif_table[iter->ct];
2427         }
2428         return NULL;
2429 }
2430 
2431 static void *ipmr_vif_seq_start(struct seq_file *seq, loff_t *pos)
2432         __acquires(mrt_lock)
2433 {
2434         struct ipmr_vif_iter *iter = seq->private;
2435         struct net *net = seq_file_net(seq);
2436         struct mr_table *mrt;
2437 
2438         mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2439         if (mrt == NULL)
2440                 return ERR_PTR(-ENOENT);
2441 
2442         iter->mrt = mrt;
2443 
2444         read_lock(&mrt_lock);
2445         return *pos ? ipmr_vif_seq_idx(net, seq->private, *pos - 1)
2446                 : SEQ_START_TOKEN;
2447 }
2448 
2449 static void *ipmr_vif_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2450 {
2451         struct ipmr_vif_iter *iter = seq->private;
2452         struct net *net = seq_file_net(seq);
2453         struct mr_table *mrt = iter->mrt;
2454 
2455         ++*pos;
2456         if (v == SEQ_START_TOKEN)
2457                 return ipmr_vif_seq_idx(net, iter, 0);
2458 
2459         while (++iter->ct < mrt->maxvif) {
2460                 if (!VIF_EXISTS(mrt, iter->ct))
2461                         continue;
2462                 return &mrt->vif_table[iter->ct];
2463         }
2464         return NULL;
2465 }
2466 
2467 static void ipmr_vif_seq_stop(struct seq_file *seq, void *v)
2468         __releases(mrt_lock)
2469 {
2470         read_unlock(&mrt_lock);
2471 }
2472 
2473 static int ipmr_vif_seq_show(struct seq_file *seq, void *v)
2474 {
2475         struct ipmr_vif_iter *iter = seq->private;
2476         struct mr_table *mrt = iter->mrt;
2477 
2478         if (v == SEQ_START_TOKEN) {
2479                 seq_puts(seq,
2480                          "Interface      BytesIn  PktsIn  BytesOut PktsOut Flags Local    Remote\n");
2481         } else {
2482                 const struct vif_device *vif = v;
2483                 const char *name =  vif->dev ? vif->dev->name : "none";
2484 
2485                 seq_printf(seq,
2486                            "%2Zd %-10s %8ld %7ld  %8ld %7ld %05X %08X %08X\n",
2487                            vif - mrt->vif_table,
2488                            name, vif->bytes_in, vif->pkt_in,
2489                            vif->bytes_out, vif->pkt_out,
2490                            vif->flags, vif->local, vif->remote);
2491         }
2492         return 0;
2493 }
2494 
2495 static const struct seq_operations ipmr_vif_seq_ops = {
2496         .start = ipmr_vif_seq_start,
2497         .next  = ipmr_vif_seq_next,
2498         .stop  = ipmr_vif_seq_stop,
2499         .show  = ipmr_vif_seq_show,
2500 };
2501 
2502 static int ipmr_vif_open(struct inode *inode, struct file *file)
2503 {
2504         return seq_open_net(inode, file, &ipmr_vif_seq_ops,
2505                             sizeof(struct ipmr_vif_iter));
2506 }
2507 
2508 static const struct file_operations ipmr_vif_fops = {
2509         .owner   = THIS_MODULE,
2510         .open    = ipmr_vif_open,
2511         .read    = seq_read,
2512         .llseek  = seq_lseek,
2513         .release = seq_release_net,
2514 };
2515 
2516 struct ipmr_mfc_iter {
2517         struct seq_net_private p;
2518         struct mr_table *mrt;
2519         struct list_head *cache;
2520         int ct;
2521 };
2522 
2523 
2524 static struct mfc_cache *ipmr_mfc_seq_idx(struct net *net,
2525                                           struct ipmr_mfc_iter *it, loff_t pos)
2526 {
2527         struct mr_table *mrt = it->mrt;
2528         struct mfc_cache *mfc;
2529 
2530         rcu_read_lock();
2531         for (it->ct = 0; it->ct < MFC_LINES; it->ct++) {
2532                 it->cache = &mrt->mfc_cache_array[it->ct];
2533                 list_for_each_entry_rcu(mfc, it->cache, list)
2534                         if (pos-- == 0)
2535                                 return mfc;
2536         }
2537         rcu_read_unlock();
2538 
2539         spin_lock_bh(&mfc_unres_lock);
2540         it->cache = &mrt->mfc_unres_queue;
2541         list_for_each_entry(mfc, it->cache, list)
2542                 if (pos-- == 0)
2543                         return mfc;
2544         spin_unlock_bh(&mfc_unres_lock);
2545 
2546         it->cache = NULL;
2547         return NULL;
2548 }
2549 
2550 
2551 static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos)
2552 {
2553         struct ipmr_mfc_iter *it = seq->private;
2554         struct net *net = seq_file_net(seq);
2555         struct mr_table *mrt;
2556 
2557         mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2558         if (mrt == NULL)
2559                 return ERR_PTR(-ENOENT);
2560 
2561         it->mrt = mrt;
2562         it->cache = NULL;
2563         it->ct = 0;
2564         return *pos ? ipmr_mfc_seq_idx(net, seq->private, *pos - 1)
2565                 : SEQ_START_TOKEN;
2566 }
2567 
2568 static void *ipmr_mfc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2569 {
2570         struct mfc_cache *mfc = v;
2571         struct ipmr_mfc_iter *it = seq->private;
2572         struct net *net = seq_file_net(seq);
2573         struct mr_table *mrt = it->mrt;
2574 
2575         ++*pos;
2576 
2577         if (v == SEQ_START_TOKEN)
2578                 return ipmr_mfc_seq_idx(net, seq->private, 0);
2579 
2580         if (mfc->list.next != it->cache)
2581                 return list_entry(mfc->list.next, struct mfc_cache, list);
2582 
2583         if (it->cache == &mrt->mfc_unres_queue)
2584                 goto end_of_list;
2585 
2586         BUG_ON(it->cache != &mrt->mfc_cache_array[it->ct]);
2587 
2588         while (++it->ct < MFC_LINES) {
2589                 it->cache = &mrt->mfc_cache_array[it->ct];
2590                 if (list_empty(it->cache))
2591                         continue;
2592                 return list_first_entry(it->cache, struct mfc_cache, list);
2593         }
2594 
2595         /* exhausted cache_array, show unresolved */
2596         rcu_read_unlock();
2597         it->cache = &mrt->mfc_unres_queue;
2598         it->ct = 0;
2599 
2600         spin_lock_bh(&mfc_unres_lock);
2601         if (!list_empty(it->cache))
2602                 return list_first_entry(it->cache, struct mfc_cache, list);
2603 
2604 end_of_list:
2605         spin_unlock_bh(&mfc_unres_lock);
2606         it->cache = NULL;
2607 
2608         return NULL;
2609 }
2610 
2611 static void ipmr_mfc_seq_stop(struct seq_file *seq, void *v)
2612 {
2613         struct ipmr_mfc_iter *it = seq->private;
2614         struct mr_table *mrt = it->mrt;
2615 
2616         if (it->cache == &mrt->mfc_unres_queue)
2617                 spin_unlock_bh(&mfc_unres_lock);
2618         else if (it->cache == &mrt->mfc_cache_array[it->ct])
2619                 rcu_read_unlock();
2620 }
2621 
2622 static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
2623 {
2624         int n;
2625 
2626         if (v == SEQ_START_TOKEN) {
2627                 seq_puts(seq,
2628                  "Group    Origin   Iif     Pkts    Bytes    Wrong Oifs\n");
2629         } else {
2630                 const struct mfc_cache *mfc = v;
2631                 const struct ipmr_mfc_iter *it = seq->private;
2632                 const struct mr_table *mrt = it->mrt;
2633 
2634                 seq_printf(seq, "%08X %08X %-3hd",
2635                            (__force u32) mfc->mfc_mcastgrp,
2636                            (__force u32) mfc->mfc_origin,
2637                            mfc->mfc_parent);
2638 
2639                 if (it->cache != &mrt->mfc_unres_queue) {
2640                         seq_printf(seq, " %8lu %8lu %8lu",
2641                                    mfc->mfc_un.res.pkt,
2642                                    mfc->mfc_un.res.bytes,
2643                                    mfc->mfc_un.res.wrong_if);
2644                         for (n = mfc->mfc_un.res.minvif;
2645                              n < mfc->mfc_un.res.maxvif; n++) {
2646                                 if (VIF_EXISTS(mrt, n) &&
2647                                     mfc->mfc_un.res.ttls[n] < 255)
2648                                         seq_printf(seq,
2649                                            " %2d:%-3d",
2650                                            n, mfc->mfc_un.res.ttls[n]);
2651                         }
2652                 } else {
2653                         /* unresolved mfc_caches don't contain
2654                          * pkt, bytes and wrong_if values
2655                          */
2656                         seq_printf(seq, " %8lu %8lu %8lu", 0ul, 0ul, 0ul);
2657                 }
2658                 seq_putc(seq, '\n');
2659         }
2660         return 0;
2661 }
2662 
2663 static const struct seq_operations ipmr_mfc_seq_ops = {
2664         .start = ipmr_mfc_seq_start,
2665         .next  = ipmr_mfc_seq_next,
2666         .stop  = ipmr_mfc_seq_stop,
2667         .show  = ipmr_mfc_seq_show,
2668 };
2669 
2670 static int ipmr_mfc_open(struct inode *inode, struct file *file)
2671 {
2672         return seq_open_net(inode, file, &ipmr_mfc_seq_ops,
2673                             sizeof(struct ipmr_mfc_iter));
2674 }
2675 
2676 static const struct file_operations ipmr_mfc_fops = {
2677         .owner   = THIS_MODULE,
2678         .open    = ipmr_mfc_open,
2679         .read    = seq_read,
2680         .llseek  = seq_lseek,
2681         .release = seq_release_net,
2682 };
2683 #endif
2684 
2685 #ifdef CONFIG_IP_PIMSM_V2
2686 static const struct net_protocol pim_protocol = {
2687         .handler        =       pim_rcv,
2688         .netns_ok       =       1,
2689 };
2690 #endif
2691 
2692 
2693 /*
2694  *      Setup for IP multicast routing
2695  */
2696 static int __net_init ipmr_net_init(struct net *net)
2697 {
2698         int err;
2699 
2700         err = ipmr_rules_init(net);
2701         if (err < 0)
2702                 goto fail;
2703 
2704 #ifdef CONFIG_PROC_FS
2705         err = -ENOMEM;
2706         if (!proc_create("ip_mr_vif", 0, net->proc_net, &ipmr_vif_fops))
2707                 goto proc_vif_fail;
2708         if (!proc_create("ip_mr_cache", 0, net->proc_net, &ipmr_mfc_fops))
2709                 goto proc_cache_fail;
2710 #endif
2711         return 0;
2712 
2713 #ifdef CONFIG_PROC_FS
2714 proc_cache_fail:
2715         remove_proc_entry("ip_mr_vif", net->proc_net);
2716 proc_vif_fail:
2717         ipmr_rules_exit(net);
2718 #endif
2719 fail:
2720         return err;
2721 }
2722 
2723 static void __net_exit ipmr_net_exit(struct net *net)
2724 {
2725 #ifdef CONFIG_PROC_FS
2726         remove_proc_entry("ip_mr_cache", net->proc_net);
2727         remove_proc_entry("ip_mr_vif", net->proc_net);
2728 #endif
2729         ipmr_rules_exit(net);
2730 }
2731 
2732 static struct pernet_operations ipmr_net_ops = {
2733         .init = ipmr_net_init,
2734         .exit = ipmr_net_exit,
2735 };
2736 
2737 int __init ip_mr_init(void)
2738 {
2739         int err;
2740 
2741         mrt_cachep = kmem_cache_create("ip_mrt_cache",
2742                                        sizeof(struct mfc_cache),
2743                                        0, SLAB_HWCACHE_ALIGN | SLAB_PANIC,
2744                                        NULL);
2745         if (!mrt_cachep)
2746                 return -ENOMEM;
2747 
2748         err = register_pernet_subsys(&ipmr_net_ops);
2749         if (err)
2750                 goto reg_pernet_fail;
2751 
2752         err = register_netdevice_notifier(&ip_mr_notifier);
2753         if (err)
2754                 goto reg_notif_fail;
2755 #ifdef CONFIG_IP_PIMSM_V2
2756         if (inet_add_protocol(&pim_protocol, IPPROTO_PIM) < 0) {
2757                 pr_err("%s: can't add PIM protocol\n", __func__);
2758                 err = -EAGAIN;
2759                 goto add_proto_fail;
2760         }
2761 #endif
2762         rtnl_register(RTNL_FAMILY_IPMR, RTM_GETROUTE,
2763                       NULL, ipmr_rtm_dumproute, NULL);
2764         return 0;
2765 
2766 #ifdef CONFIG_IP_PIMSM_V2
2767 add_proto_fail:
2768         unregister_netdevice_notifier(&ip_mr_notifier);
2769 #endif
2770 reg_notif_fail:
2771         unregister_pernet_subsys(&ipmr_net_ops);
2772 reg_pernet_fail:
2773         kmem_cache_destroy(mrt_cachep);
2774         return err;
2775 }
2776 

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