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TOMOYO Linux Cross Reference
Linux/net/decnet/dn_route.c

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  1 /*
  2  * DECnet       An implementation of the DECnet protocol suite for the LINUX
  3  *              operating system.  DECnet is implemented using the  BSD Socket
  4  *              interface as the means of communication with the user level.
  5  *
  6  *              DECnet Routing Functions (Endnode and Router)
  7  *
  8  * Authors:     Steve Whitehouse <SteveW@ACM.org>
  9  *              Eduardo Marcelo Serrat <emserrat@geocities.com>
 10  *
 11  * Changes:
 12  *              Steve Whitehouse : Fixes to allow "intra-ethernet" and
 13  *                                 "return-to-sender" bits on outgoing
 14  *                                 packets.
 15  *              Steve Whitehouse : Timeouts for cached routes.
 16  *              Steve Whitehouse : Use dst cache for input routes too.
 17  *              Steve Whitehouse : Fixed error values in dn_send_skb.
 18  *              Steve Whitehouse : Rework routing functions to better fit
 19  *                                 DECnet routing design
 20  *              Alexey Kuznetsov : New SMP locking
 21  *              Steve Whitehouse : More SMP locking changes & dn_cache_dump()
 22  *              Steve Whitehouse : Prerouting NF hook, now really is prerouting.
 23  *                                 Fixed possible skb leak in rtnetlink funcs.
 24  *              Steve Whitehouse : Dave Miller's dynamic hash table sizing and
 25  *                                 Alexey Kuznetsov's finer grained locking
 26  *                                 from ipv4/route.c.
 27  *              Steve Whitehouse : Routing is now starting to look like a
 28  *                                 sensible set of code now, mainly due to
 29  *                                 my copying the IPv4 routing code. The
 30  *                                 hooks here are modified and will continue
 31  *                                 to evolve for a while.
 32  *              Steve Whitehouse : Real SMP at last :-) Also new netfilter
 33  *                                 stuff. Look out raw sockets your days
 34  *                                 are numbered!
 35  *              Steve Whitehouse : Added return-to-sender functions. Added
 36  *                                 backlog congestion level return codes.
 37  *              Steve Whitehouse : Fixed bug where routes were set up with
 38  *                                 no ref count on net devices.
 39  *              Steve Whitehouse : RCU for the route cache
 40  *              Steve Whitehouse : Preparations for the flow cache
 41  *              Steve Whitehouse : Prepare for nonlinear skbs
 42  */
 43 
 44 /******************************************************************************
 45     (c) 1995-1998 E.M. Serrat           emserrat@geocities.com
 46 
 47     This program is free software; you can redistribute it and/or modify
 48     it under the terms of the GNU General Public License as published by
 49     the Free Software Foundation; either version 2 of the License, or
 50     any later version.
 51 
 52     This program is distributed in the hope that it will be useful,
 53     but WITHOUT ANY WARRANTY; without even the implied warranty of
 54     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 55     GNU General Public License for more details.
 56 *******************************************************************************/
 57 
 58 #include <linux/errno.h>
 59 #include <linux/types.h>
 60 #include <linux/socket.h>
 61 #include <linux/in.h>
 62 #include <linux/kernel.h>
 63 #include <linux/sockios.h>
 64 #include <linux/net.h>
 65 #include <linux/netdevice.h>
 66 #include <linux/inet.h>
 67 #include <linux/route.h>
 68 #include <linux/in_route.h>
 69 #include <linux/slab.h>
 70 #include <net/sock.h>
 71 #include <linux/mm.h>
 72 #include <linux/proc_fs.h>
 73 #include <linux/seq_file.h>
 74 #include <linux/init.h>
 75 #include <linux/rtnetlink.h>
 76 #include <linux/string.h>
 77 #include <linux/netfilter_decnet.h>
 78 #include <linux/rcupdate.h>
 79 #include <linux/times.h>
 80 #include <linux/export.h>
 81 #include <asm/errno.h>
 82 #include <net/net_namespace.h>
 83 #include <net/netlink.h>
 84 #include <net/neighbour.h>
 85 #include <net/dst.h>
 86 #include <net/flow.h>
 87 #include <net/fib_rules.h>
 88 #include <net/dn.h>
 89 #include <net/dn_dev.h>
 90 #include <net/dn_nsp.h>
 91 #include <net/dn_route.h>
 92 #include <net/dn_neigh.h>
 93 #include <net/dn_fib.h>
 94 
 95 struct dn_rt_hash_bucket
 96 {
 97         struct dn_route __rcu *chain;
 98         spinlock_t lock;
 99 };
100 
101 extern struct neigh_table dn_neigh_table;
102 
103 
104 static unsigned char dn_hiord_addr[6] = {0xAA,0x00,0x04,0x00,0x00,0x00};
105 
106 static const int dn_rt_min_delay = 2 * HZ;
107 static const int dn_rt_max_delay = 10 * HZ;
108 static const int dn_rt_mtu_expires = 10 * 60 * HZ;
109 
110 static unsigned long dn_rt_deadline;
111 
112 static int dn_dst_gc(struct dst_ops *ops);
113 static struct dst_entry *dn_dst_check(struct dst_entry *, __u32);
114 static unsigned int dn_dst_default_advmss(const struct dst_entry *dst);
115 static unsigned int dn_dst_mtu(const struct dst_entry *dst);
116 static void dn_dst_destroy(struct dst_entry *);
117 static void dn_dst_ifdown(struct dst_entry *, struct net_device *dev, int how);
118 static struct dst_entry *dn_dst_negative_advice(struct dst_entry *);
119 static void dn_dst_link_failure(struct sk_buff *);
120 static void dn_dst_update_pmtu(struct dst_entry *dst, struct sock *sk,
121                                struct sk_buff *skb , u32 mtu);
122 static void dn_dst_redirect(struct dst_entry *dst, struct sock *sk,
123                             struct sk_buff *skb);
124 static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst,
125                                              struct sk_buff *skb,
126                                              const void *daddr);
127 static int dn_route_input(struct sk_buff *);
128 static void dn_run_flush(unsigned long dummy);
129 
130 static struct dn_rt_hash_bucket *dn_rt_hash_table;
131 static unsigned int dn_rt_hash_mask;
132 
133 static struct timer_list dn_route_timer;
134 static DEFINE_TIMER(dn_rt_flush_timer, dn_run_flush, 0, 0);
135 int decnet_dst_gc_interval = 2;
136 
137 static struct dst_ops dn_dst_ops = {
138         .family =               PF_DECnet,
139         .gc_thresh =            128,
140         .gc =                   dn_dst_gc,
141         .check =                dn_dst_check,
142         .default_advmss =       dn_dst_default_advmss,
143         .mtu =                  dn_dst_mtu,
144         .cow_metrics =          dst_cow_metrics_generic,
145         .destroy =              dn_dst_destroy,
146         .ifdown =               dn_dst_ifdown,
147         .negative_advice =      dn_dst_negative_advice,
148         .link_failure =         dn_dst_link_failure,
149         .update_pmtu =          dn_dst_update_pmtu,
150         .redirect =             dn_dst_redirect,
151         .neigh_lookup =         dn_dst_neigh_lookup,
152 };
153 
154 static void dn_dst_destroy(struct dst_entry *dst)
155 {
156         struct dn_route *rt = (struct dn_route *) dst;
157 
158         if (rt->n)
159                 neigh_release(rt->n);
160         dst_destroy_metrics_generic(dst);
161 }
162 
163 static void dn_dst_ifdown(struct dst_entry *dst, struct net_device *dev, int how)
164 {
165         if (how) {
166                 struct dn_route *rt = (struct dn_route *) dst;
167                 struct neighbour *n = rt->n;
168 
169                 if (n && n->dev == dev) {
170                         n->dev = dev_net(dev)->loopback_dev;
171                         dev_hold(n->dev);
172                         dev_put(dev);
173                 }
174         }
175 }
176 
177 static __inline__ unsigned int dn_hash(__le16 src, __le16 dst)
178 {
179         __u16 tmp = (__u16 __force)(src ^ dst);
180         tmp ^= (tmp >> 3);
181         tmp ^= (tmp >> 5);
182         tmp ^= (tmp >> 10);
183         return dn_rt_hash_mask & (unsigned int)tmp;
184 }
185 
186 static inline void dnrt_free(struct dn_route *rt)
187 {
188         call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
189 }
190 
191 static inline void dnrt_drop(struct dn_route *rt)
192 {
193         dst_release(&rt->dst);
194         call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
195 }
196 
197 static void dn_dst_check_expire(unsigned long dummy)
198 {
199         int i;
200         struct dn_route *rt;
201         struct dn_route __rcu **rtp;
202         unsigned long now = jiffies;
203         unsigned long expire = 120 * HZ;
204 
205         for (i = 0; i <= dn_rt_hash_mask; i++) {
206                 rtp = &dn_rt_hash_table[i].chain;
207 
208                 spin_lock(&dn_rt_hash_table[i].lock);
209                 while ((rt = rcu_dereference_protected(*rtp,
210                                                 lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) {
211                         if (atomic_read(&rt->dst.__refcnt) ||
212                                         (now - rt->dst.lastuse) < expire) {
213                                 rtp = &rt->dst.dn_next;
214                                 continue;
215                         }
216                         *rtp = rt->dst.dn_next;
217                         rt->dst.dn_next = NULL;
218                         dnrt_free(rt);
219                 }
220                 spin_unlock(&dn_rt_hash_table[i].lock);
221 
222                 if ((jiffies - now) > 0)
223                         break;
224         }
225 
226         mod_timer(&dn_route_timer, now + decnet_dst_gc_interval * HZ);
227 }
228 
229 static int dn_dst_gc(struct dst_ops *ops)
230 {
231         struct dn_route *rt;
232         struct dn_route __rcu **rtp;
233         int i;
234         unsigned long now = jiffies;
235         unsigned long expire = 10 * HZ;
236 
237         for (i = 0; i <= dn_rt_hash_mask; i++) {
238 
239                 spin_lock_bh(&dn_rt_hash_table[i].lock);
240                 rtp = &dn_rt_hash_table[i].chain;
241 
242                 while ((rt = rcu_dereference_protected(*rtp,
243                                                 lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) {
244                         if (atomic_read(&rt->dst.__refcnt) ||
245                                         (now - rt->dst.lastuse) < expire) {
246                                 rtp = &rt->dst.dn_next;
247                                 continue;
248                         }
249                         *rtp = rt->dst.dn_next;
250                         rt->dst.dn_next = NULL;
251                         dnrt_drop(rt);
252                         break;
253                 }
254                 spin_unlock_bh(&dn_rt_hash_table[i].lock);
255         }
256 
257         return 0;
258 }
259 
260 /*
261  * The decnet standards don't impose a particular minimum mtu, what they
262  * do insist on is that the routing layer accepts a datagram of at least
263  * 230 bytes long. Here we have to subtract the routing header length from
264  * 230 to get the minimum acceptable mtu. If there is no neighbour, then we
265  * assume the worst and use a long header size.
266  *
267  * We update both the mtu and the advertised mss (i.e. the segment size we
268  * advertise to the other end).
269  */
270 static void dn_dst_update_pmtu(struct dst_entry *dst, struct sock *sk,
271                                struct sk_buff *skb, u32 mtu)
272 {
273         struct dn_route *rt = (struct dn_route *) dst;
274         struct neighbour *n = rt->n;
275         u32 min_mtu = 230;
276         struct dn_dev *dn;
277 
278         dn = n ? rcu_dereference_raw(n->dev->dn_ptr) : NULL;
279 
280         if (dn && dn->use_long == 0)
281                 min_mtu -= 6;
282         else
283                 min_mtu -= 21;
284 
285         if (dst_metric(dst, RTAX_MTU) > mtu && mtu >= min_mtu) {
286                 if (!(dst_metric_locked(dst, RTAX_MTU))) {
287                         dst_metric_set(dst, RTAX_MTU, mtu);
288                         dst_set_expires(dst, dn_rt_mtu_expires);
289                 }
290                 if (!(dst_metric_locked(dst, RTAX_ADVMSS))) {
291                         u32 mss = mtu - DN_MAX_NSP_DATA_HEADER;
292                         u32 existing_mss = dst_metric_raw(dst, RTAX_ADVMSS);
293                         if (!existing_mss || existing_mss > mss)
294                                 dst_metric_set(dst, RTAX_ADVMSS, mss);
295                 }
296         }
297 }
298 
299 static void dn_dst_redirect(struct dst_entry *dst, struct sock *sk,
300                             struct sk_buff *skb)
301 {
302 }
303 
304 /*
305  * When a route has been marked obsolete. (e.g. routing cache flush)
306  */
307 static struct dst_entry *dn_dst_check(struct dst_entry *dst, __u32 cookie)
308 {
309         return NULL;
310 }
311 
312 static struct dst_entry *dn_dst_negative_advice(struct dst_entry *dst)
313 {
314         dst_release(dst);
315         return NULL;
316 }
317 
318 static void dn_dst_link_failure(struct sk_buff *skb)
319 {
320 }
321 
322 static inline int compare_keys(struct flowidn *fl1, struct flowidn *fl2)
323 {
324         return ((fl1->daddr ^ fl2->daddr) |
325                 (fl1->saddr ^ fl2->saddr) |
326                 (fl1->flowidn_mark ^ fl2->flowidn_mark) |
327                 (fl1->flowidn_scope ^ fl2->flowidn_scope) |
328                 (fl1->flowidn_oif ^ fl2->flowidn_oif) |
329                 (fl1->flowidn_iif ^ fl2->flowidn_iif)) == 0;
330 }
331 
332 static int dn_insert_route(struct dn_route *rt, unsigned int hash, struct dn_route **rp)
333 {
334         struct dn_route *rth;
335         struct dn_route __rcu **rthp;
336         unsigned long now = jiffies;
337 
338         rthp = &dn_rt_hash_table[hash].chain;
339 
340         spin_lock_bh(&dn_rt_hash_table[hash].lock);
341         while ((rth = rcu_dereference_protected(*rthp,
342                                                 lockdep_is_held(&dn_rt_hash_table[hash].lock))) != NULL) {
343                 if (compare_keys(&rth->fld, &rt->fld)) {
344                         /* Put it first */
345                         *rthp = rth->dst.dn_next;
346                         rcu_assign_pointer(rth->dst.dn_next,
347                                            dn_rt_hash_table[hash].chain);
348                         rcu_assign_pointer(dn_rt_hash_table[hash].chain, rth);
349 
350                         dst_use(&rth->dst, now);
351                         spin_unlock_bh(&dn_rt_hash_table[hash].lock);
352 
353                         dnrt_drop(rt);
354                         *rp = rth;
355                         return 0;
356                 }
357                 rthp = &rth->dst.dn_next;
358         }
359 
360         rcu_assign_pointer(rt->dst.dn_next, dn_rt_hash_table[hash].chain);
361         rcu_assign_pointer(dn_rt_hash_table[hash].chain, rt);
362 
363         dst_use(&rt->dst, now);
364         spin_unlock_bh(&dn_rt_hash_table[hash].lock);
365         *rp = rt;
366         return 0;
367 }
368 
369 static void dn_run_flush(unsigned long dummy)
370 {
371         int i;
372         struct dn_route *rt, *next;
373 
374         for (i = 0; i < dn_rt_hash_mask; i++) {
375                 spin_lock_bh(&dn_rt_hash_table[i].lock);
376 
377                 if ((rt = xchg((struct dn_route **)&dn_rt_hash_table[i].chain, NULL)) == NULL)
378                         goto nothing_to_declare;
379 
380                 for(; rt; rt = next) {
381                         next = rcu_dereference_raw(rt->dst.dn_next);
382                         RCU_INIT_POINTER(rt->dst.dn_next, NULL);
383                         dst_free((struct dst_entry *)rt);
384                 }
385 
386 nothing_to_declare:
387                 spin_unlock_bh(&dn_rt_hash_table[i].lock);
388         }
389 }
390 
391 static DEFINE_SPINLOCK(dn_rt_flush_lock);
392 
393 void dn_rt_cache_flush(int delay)
394 {
395         unsigned long now = jiffies;
396         int user_mode = !in_interrupt();
397 
398         if (delay < 0)
399                 delay = dn_rt_min_delay;
400 
401         spin_lock_bh(&dn_rt_flush_lock);
402 
403         if (del_timer(&dn_rt_flush_timer) && delay > 0 && dn_rt_deadline) {
404                 long tmo = (long)(dn_rt_deadline - now);
405 
406                 if (user_mode && tmo < dn_rt_max_delay - dn_rt_min_delay)
407                         tmo = 0;
408 
409                 if (delay > tmo)
410                         delay = tmo;
411         }
412 
413         if (delay <= 0) {
414                 spin_unlock_bh(&dn_rt_flush_lock);
415                 dn_run_flush(0);
416                 return;
417         }
418 
419         if (dn_rt_deadline == 0)
420                 dn_rt_deadline = now + dn_rt_max_delay;
421 
422         dn_rt_flush_timer.expires = now + delay;
423         add_timer(&dn_rt_flush_timer);
424         spin_unlock_bh(&dn_rt_flush_lock);
425 }
426 
427 /**
428  * dn_return_short - Return a short packet to its sender
429  * @skb: The packet to return
430  *
431  */
432 static int dn_return_short(struct sk_buff *skb)
433 {
434         struct dn_skb_cb *cb;
435         unsigned char *ptr;
436         __le16 *src;
437         __le16 *dst;
438 
439         /* Add back headers */
440         skb_push(skb, skb->data - skb_network_header(skb));
441 
442         if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
443                 return NET_RX_DROP;
444 
445         cb = DN_SKB_CB(skb);
446         /* Skip packet length and point to flags */
447         ptr = skb->data + 2;
448         *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
449 
450         dst = (__le16 *)ptr;
451         ptr += 2;
452         src = (__le16 *)ptr;
453         ptr += 2;
454         *ptr = 0; /* Zero hop count */
455 
456         swap(*src, *dst);
457 
458         skb->pkt_type = PACKET_OUTGOING;
459         dn_rt_finish_output(skb, NULL, NULL);
460         return NET_RX_SUCCESS;
461 }
462 
463 /**
464  * dn_return_long - Return a long packet to its sender
465  * @skb: The long format packet to return
466  *
467  */
468 static int dn_return_long(struct sk_buff *skb)
469 {
470         struct dn_skb_cb *cb;
471         unsigned char *ptr;
472         unsigned char *src_addr, *dst_addr;
473         unsigned char tmp[ETH_ALEN];
474 
475         /* Add back all headers */
476         skb_push(skb, skb->data - skb_network_header(skb));
477 
478         if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
479                 return NET_RX_DROP;
480 
481         cb = DN_SKB_CB(skb);
482         /* Ignore packet length and point to flags */
483         ptr = skb->data + 2;
484 
485         /* Skip padding */
486         if (*ptr & DN_RT_F_PF) {
487                 char padlen = (*ptr & ~DN_RT_F_PF);
488                 ptr += padlen;
489         }
490 
491         *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
492         ptr += 2;
493         dst_addr = ptr;
494         ptr += 8;
495         src_addr = ptr;
496         ptr += 6;
497         *ptr = 0; /* Zero hop count */
498 
499         /* Swap source and destination */
500         memcpy(tmp, src_addr, ETH_ALEN);
501         memcpy(src_addr, dst_addr, ETH_ALEN);
502         memcpy(dst_addr, tmp, ETH_ALEN);
503 
504         skb->pkt_type = PACKET_OUTGOING;
505         dn_rt_finish_output(skb, dst_addr, src_addr);
506         return NET_RX_SUCCESS;
507 }
508 
509 /**
510  * dn_route_rx_packet - Try and find a route for an incoming packet
511  * @skb: The packet to find a route for
512  *
513  * Returns: result of input function if route is found, error code otherwise
514  */
515 static int dn_route_rx_packet(struct net *net, struct sock *sk, struct sk_buff *skb)
516 {
517         struct dn_skb_cb *cb;
518         int err;
519 
520         if ((err = dn_route_input(skb)) == 0)
521                 return dst_input(skb);
522 
523         cb = DN_SKB_CB(skb);
524         if (decnet_debug_level & 4) {
525                 char *devname = skb->dev ? skb->dev->name : "???";
526 
527                 printk(KERN_DEBUG
528                         "DECnet: dn_route_rx_packet: rt_flags=0x%02x dev=%s len=%d src=0x%04hx dst=0x%04hx err=%d type=%d\n",
529                         (int)cb->rt_flags, devname, skb->len,
530                         le16_to_cpu(cb->src), le16_to_cpu(cb->dst),
531                         err, skb->pkt_type);
532         }
533 
534         if ((skb->pkt_type == PACKET_HOST) && (cb->rt_flags & DN_RT_F_RQR)) {
535                 switch (cb->rt_flags & DN_RT_PKT_MSK) {
536                 case DN_RT_PKT_SHORT:
537                         return dn_return_short(skb);
538                 case DN_RT_PKT_LONG:
539                         return dn_return_long(skb);
540                 }
541         }
542 
543         kfree_skb(skb);
544         return NET_RX_DROP;
545 }
546 
547 static int dn_route_rx_long(struct sk_buff *skb)
548 {
549         struct dn_skb_cb *cb = DN_SKB_CB(skb);
550         unsigned char *ptr = skb->data;
551 
552         if (!pskb_may_pull(skb, 21)) /* 20 for long header, 1 for shortest nsp */
553                 goto drop_it;
554 
555         skb_pull(skb, 20);
556         skb_reset_transport_header(skb);
557 
558         /* Destination info */
559         ptr += 2;
560         cb->dst = dn_eth2dn(ptr);
561         if (memcmp(ptr, dn_hiord_addr, 4) != 0)
562                 goto drop_it;
563         ptr += 6;
564 
565 
566         /* Source info */
567         ptr += 2;
568         cb->src = dn_eth2dn(ptr);
569         if (memcmp(ptr, dn_hiord_addr, 4) != 0)
570                 goto drop_it;
571         ptr += 6;
572         /* Other junk */
573         ptr++;
574         cb->hops = *ptr++; /* Visit Count */
575 
576         return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING,
577                        &init_net, NULL, skb, skb->dev, NULL,
578                        dn_route_rx_packet);
579 
580 drop_it:
581         kfree_skb(skb);
582         return NET_RX_DROP;
583 }
584 
585 
586 
587 static int dn_route_rx_short(struct sk_buff *skb)
588 {
589         struct dn_skb_cb *cb = DN_SKB_CB(skb);
590         unsigned char *ptr = skb->data;
591 
592         if (!pskb_may_pull(skb, 6)) /* 5 for short header + 1 for shortest nsp */
593                 goto drop_it;
594 
595         skb_pull(skb, 5);
596         skb_reset_transport_header(skb);
597 
598         cb->dst = *(__le16 *)ptr;
599         ptr += 2;
600         cb->src = *(__le16 *)ptr;
601         ptr += 2;
602         cb->hops = *ptr & 0x3f;
603 
604         return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING,
605                        &init_net, NULL, skb, skb->dev, NULL,
606                        dn_route_rx_packet);
607 
608 drop_it:
609         kfree_skb(skb);
610         return NET_RX_DROP;
611 }
612 
613 static int dn_route_discard(struct net *net, struct sock *sk, struct sk_buff *skb)
614 {
615         /*
616          * I know we drop the packet here, but thats considered success in
617          * this case
618          */
619         kfree_skb(skb);
620         return NET_RX_SUCCESS;
621 }
622 
623 static int dn_route_ptp_hello(struct net *net, struct sock *sk, struct sk_buff *skb)
624 {
625         dn_dev_hello(skb);
626         dn_neigh_pointopoint_hello(skb);
627         return NET_RX_SUCCESS;
628 }
629 
630 int dn_route_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
631 {
632         struct dn_skb_cb *cb;
633         unsigned char flags = 0;
634         __u16 len = le16_to_cpu(*(__le16 *)skb->data);
635         struct dn_dev *dn = rcu_dereference(dev->dn_ptr);
636         unsigned char padlen = 0;
637 
638         if (!net_eq(dev_net(dev), &init_net))
639                 goto dump_it;
640 
641         if (dn == NULL)
642                 goto dump_it;
643 
644         if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
645                 goto out;
646 
647         if (!pskb_may_pull(skb, 3))
648                 goto dump_it;
649 
650         skb_pull(skb, 2);
651 
652         if (len > skb->len)
653                 goto dump_it;
654 
655         skb_trim(skb, len);
656 
657         flags = *skb->data;
658 
659         cb = DN_SKB_CB(skb);
660         cb->stamp = jiffies;
661         cb->iif = dev->ifindex;
662 
663         /*
664          * If we have padding, remove it.
665          */
666         if (flags & DN_RT_F_PF) {
667                 padlen = flags & ~DN_RT_F_PF;
668                 if (!pskb_may_pull(skb, padlen + 1))
669                         goto dump_it;
670                 skb_pull(skb, padlen);
671                 flags = *skb->data;
672         }
673 
674         skb_reset_network_header(skb);
675 
676         /*
677          * Weed out future version DECnet
678          */
679         if (flags & DN_RT_F_VER)
680                 goto dump_it;
681 
682         cb->rt_flags = flags;
683 
684         if (decnet_debug_level & 1)
685                 printk(KERN_DEBUG
686                         "dn_route_rcv: got 0x%02x from %s [%d %d %d]\n",
687                         (int)flags, (dev) ? dev->name : "???", len, skb->len,
688                         padlen);
689 
690         if (flags & DN_RT_PKT_CNTL) {
691                 if (unlikely(skb_linearize(skb)))
692                         goto dump_it;
693 
694                 switch (flags & DN_RT_CNTL_MSK) {
695                 case DN_RT_PKT_INIT:
696                         dn_dev_init_pkt(skb);
697                         break;
698                 case DN_RT_PKT_VERI:
699                         dn_dev_veri_pkt(skb);
700                         break;
701                 }
702 
703                 if (dn->parms.state != DN_DEV_S_RU)
704                         goto dump_it;
705 
706                 switch (flags & DN_RT_CNTL_MSK) {
707                 case DN_RT_PKT_HELO:
708                         return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
709                                        &init_net, NULL, skb, skb->dev, NULL,
710                                        dn_route_ptp_hello);
711 
712                 case DN_RT_PKT_L1RT:
713                 case DN_RT_PKT_L2RT:
714                         return NF_HOOK(NFPROTO_DECNET, NF_DN_ROUTE,
715                                        &init_net, NULL, skb, skb->dev, NULL,
716                                        dn_route_discard);
717                 case DN_RT_PKT_ERTH:
718                         return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
719                                        &init_net, NULL, skb, skb->dev, NULL,
720                                        dn_neigh_router_hello);
721 
722                 case DN_RT_PKT_EEDH:
723                         return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
724                                        &init_net, NULL, skb, skb->dev, NULL,
725                                        dn_neigh_endnode_hello);
726                 }
727         } else {
728                 if (dn->parms.state != DN_DEV_S_RU)
729                         goto dump_it;
730 
731                 skb_pull(skb, 1); /* Pull flags */
732 
733                 switch (flags & DN_RT_PKT_MSK) {
734                 case DN_RT_PKT_LONG:
735                         return dn_route_rx_long(skb);
736                 case DN_RT_PKT_SHORT:
737                         return dn_route_rx_short(skb);
738                 }
739         }
740 
741 dump_it:
742         kfree_skb(skb);
743 out:
744         return NET_RX_DROP;
745 }
746 
747 static int dn_output(struct net *net, struct sock *sk, struct sk_buff *skb)
748 {
749         struct dst_entry *dst = skb_dst(skb);
750         struct dn_route *rt = (struct dn_route *)dst;
751         struct net_device *dev = dst->dev;
752         struct dn_skb_cb *cb = DN_SKB_CB(skb);
753 
754         int err = -EINVAL;
755 
756         if (rt->n == NULL)
757                 goto error;
758 
759         skb->dev = dev;
760 
761         cb->src = rt->rt_saddr;
762         cb->dst = rt->rt_daddr;
763 
764         /*
765          * Always set the Intra-Ethernet bit on all outgoing packets
766          * originated on this node. Only valid flag from upper layers
767          * is return-to-sender-requested. Set hop count to 0 too.
768          */
769         cb->rt_flags &= ~DN_RT_F_RQR;
770         cb->rt_flags |= DN_RT_F_IE;
771         cb->hops = 0;
772 
773         return NF_HOOK(NFPROTO_DECNET, NF_DN_LOCAL_OUT,
774                        &init_net, sk, skb, NULL, dev,
775                        dn_to_neigh_output);
776 
777 error:
778         net_dbg_ratelimited("dn_output: This should not happen\n");
779 
780         kfree_skb(skb);
781 
782         return err;
783 }
784 
785 static int dn_forward(struct sk_buff *skb)
786 {
787         struct dn_skb_cb *cb = DN_SKB_CB(skb);
788         struct dst_entry *dst = skb_dst(skb);
789         struct dn_dev *dn_db = rcu_dereference(dst->dev->dn_ptr);
790         struct dn_route *rt;
791         int header_len;
792         struct net_device *dev = skb->dev;
793 
794         if (skb->pkt_type != PACKET_HOST)
795                 goto drop;
796 
797         /* Ensure that we have enough space for headers */
798         rt = (struct dn_route *)skb_dst(skb);
799         header_len = dn_db->use_long ? 21 : 6;
800         if (skb_cow(skb, LL_RESERVED_SPACE(rt->dst.dev)+header_len))
801                 goto drop;
802 
803         /*
804          * Hop count exceeded.
805          */
806         if (++cb->hops > 30)
807                 goto drop;
808 
809         skb->dev = rt->dst.dev;
810 
811         /*
812          * If packet goes out same interface it came in on, then set
813          * the Intra-Ethernet bit. This has no effect for short
814          * packets, so we don't need to test for them here.
815          */
816         cb->rt_flags &= ~DN_RT_F_IE;
817         if (rt->rt_flags & RTCF_DOREDIRECT)
818                 cb->rt_flags |= DN_RT_F_IE;
819 
820         return NF_HOOK(NFPROTO_DECNET, NF_DN_FORWARD,
821                        &init_net, NULL, skb, dev, skb->dev,
822                        dn_to_neigh_output);
823 
824 drop:
825         kfree_skb(skb);
826         return NET_RX_DROP;
827 }
828 
829 /*
830  * Used to catch bugs. This should never normally get
831  * called.
832  */
833 static int dn_rt_bug_out(struct net *net, struct sock *sk, struct sk_buff *skb)
834 {
835         struct dn_skb_cb *cb = DN_SKB_CB(skb);
836 
837         net_dbg_ratelimited("dn_rt_bug: skb from:%04x to:%04x\n",
838                             le16_to_cpu(cb->src), le16_to_cpu(cb->dst));
839 
840         kfree_skb(skb);
841 
842         return NET_RX_DROP;
843 }
844 
845 static int dn_rt_bug(struct sk_buff *skb)
846 {
847         struct dn_skb_cb *cb = DN_SKB_CB(skb);
848 
849         net_dbg_ratelimited("dn_rt_bug: skb from:%04x to:%04x\n",
850                             le16_to_cpu(cb->src), le16_to_cpu(cb->dst));
851 
852         kfree_skb(skb);
853 
854         return NET_RX_DROP;
855 }
856 
857 static unsigned int dn_dst_default_advmss(const struct dst_entry *dst)
858 {
859         return dn_mss_from_pmtu(dst->dev, dst_mtu(dst));
860 }
861 
862 static unsigned int dn_dst_mtu(const struct dst_entry *dst)
863 {
864         unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
865 
866         return mtu ? : dst->dev->mtu;
867 }
868 
869 static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst,
870                                              struct sk_buff *skb,
871                                              const void *daddr)
872 {
873         return __neigh_lookup_errno(&dn_neigh_table, daddr, dst->dev);
874 }
875 
876 static int dn_rt_set_next_hop(struct dn_route *rt, struct dn_fib_res *res)
877 {
878         struct dn_fib_info *fi = res->fi;
879         struct net_device *dev = rt->dst.dev;
880         unsigned int mss_metric;
881         struct neighbour *n;
882 
883         if (fi) {
884                 if (DN_FIB_RES_GW(*res) &&
885                     DN_FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
886                         rt->rt_gateway = DN_FIB_RES_GW(*res);
887                 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
888         }
889         rt->rt_type = res->type;
890 
891         if (dev != NULL && rt->n == NULL) {
892                 n = __neigh_lookup_errno(&dn_neigh_table, &rt->rt_gateway, dev);
893                 if (IS_ERR(n))
894                         return PTR_ERR(n);
895                 rt->n = n;
896         }
897 
898         if (dst_metric(&rt->dst, RTAX_MTU) > rt->dst.dev->mtu)
899                 dst_metric_set(&rt->dst, RTAX_MTU, rt->dst.dev->mtu);
900         mss_metric = dst_metric_raw(&rt->dst, RTAX_ADVMSS);
901         if (mss_metric) {
902                 unsigned int mss = dn_mss_from_pmtu(dev, dst_mtu(&rt->dst));
903                 if (mss_metric > mss)
904                         dst_metric_set(&rt->dst, RTAX_ADVMSS, mss);
905         }
906         return 0;
907 }
908 
909 static inline int dn_match_addr(__le16 addr1, __le16 addr2)
910 {
911         __u16 tmp = le16_to_cpu(addr1) ^ le16_to_cpu(addr2);
912         int match = 16;
913         while(tmp) {
914                 tmp >>= 1;
915                 match--;
916         }
917         return match;
918 }
919 
920 static __le16 dnet_select_source(const struct net_device *dev, __le16 daddr, int scope)
921 {
922         __le16 saddr = 0;
923         struct dn_dev *dn_db;
924         struct dn_ifaddr *ifa;
925         int best_match = 0;
926         int ret;
927 
928         rcu_read_lock();
929         dn_db = rcu_dereference(dev->dn_ptr);
930         for (ifa = rcu_dereference(dn_db->ifa_list);
931              ifa != NULL;
932              ifa = rcu_dereference(ifa->ifa_next)) {
933                 if (ifa->ifa_scope > scope)
934                         continue;
935                 if (!daddr) {
936                         saddr = ifa->ifa_local;
937                         break;
938                 }
939                 ret = dn_match_addr(daddr, ifa->ifa_local);
940                 if (ret > best_match)
941                         saddr = ifa->ifa_local;
942                 if (best_match == 0)
943                         saddr = ifa->ifa_local;
944         }
945         rcu_read_unlock();
946 
947         return saddr;
948 }
949 
950 static inline __le16 __dn_fib_res_prefsrc(struct dn_fib_res *res)
951 {
952         return dnet_select_source(DN_FIB_RES_DEV(*res), DN_FIB_RES_GW(*res), res->scope);
953 }
954 
955 static inline __le16 dn_fib_rules_map_destination(__le16 daddr, struct dn_fib_res *res)
956 {
957         __le16 mask = dnet_make_mask(res->prefixlen);
958         return (daddr&~mask)|res->fi->fib_nh->nh_gw;
959 }
960 
961 static int dn_route_output_slow(struct dst_entry **pprt, const struct flowidn *oldflp, int try_hard)
962 {
963         struct flowidn fld = {
964                 .daddr = oldflp->daddr,
965                 .saddr = oldflp->saddr,
966                 .flowidn_scope = RT_SCOPE_UNIVERSE,
967                 .flowidn_mark = oldflp->flowidn_mark,
968                 .flowidn_iif = LOOPBACK_IFINDEX,
969                 .flowidn_oif = oldflp->flowidn_oif,
970         };
971         struct dn_route *rt = NULL;
972         struct net_device *dev_out = NULL, *dev;
973         struct neighbour *neigh = NULL;
974         unsigned int hash;
975         unsigned int flags = 0;
976         struct dn_fib_res res = { .fi = NULL, .type = RTN_UNICAST };
977         int err;
978         int free_res = 0;
979         __le16 gateway = 0;
980 
981         if (decnet_debug_level & 16)
982                 printk(KERN_DEBUG
983                        "dn_route_output_slow: dst=%04x src=%04x mark=%d"
984                        " iif=%d oif=%d\n", le16_to_cpu(oldflp->daddr),
985                        le16_to_cpu(oldflp->saddr),
986                        oldflp->flowidn_mark, LOOPBACK_IFINDEX,
987                        oldflp->flowidn_oif);
988 
989         /* If we have an output interface, verify its a DECnet device */
990         if (oldflp->flowidn_oif) {
991                 dev_out = dev_get_by_index(&init_net, oldflp->flowidn_oif);
992                 err = -ENODEV;
993                 if (dev_out && dev_out->dn_ptr == NULL) {
994                         dev_put(dev_out);
995                         dev_out = NULL;
996                 }
997                 if (dev_out == NULL)
998                         goto out;
999         }
1000 
1001         /* If we have a source address, verify that its a local address */
1002         if (oldflp->saddr) {
1003                 err = -EADDRNOTAVAIL;
1004 
1005                 if (dev_out) {
1006                         if (dn_dev_islocal(dev_out, oldflp->saddr))
1007                                 goto source_ok;
1008                         dev_put(dev_out);
1009                         goto out;
1010                 }
1011                 rcu_read_lock();
1012                 for_each_netdev_rcu(&init_net, dev) {
1013                         if (!dev->dn_ptr)
1014                                 continue;
1015                         if (!dn_dev_islocal(dev, oldflp->saddr))
1016                                 continue;
1017                         if ((dev->flags & IFF_LOOPBACK) &&
1018                             oldflp->daddr &&
1019                             !dn_dev_islocal(dev, oldflp->daddr))
1020                                 continue;
1021 
1022                         dev_out = dev;
1023                         break;
1024                 }
1025                 rcu_read_unlock();
1026                 if (dev_out == NULL)
1027                         goto out;
1028                 dev_hold(dev_out);
1029 source_ok:
1030                 ;
1031         }
1032 
1033         /* No destination? Assume its local */
1034         if (!fld.daddr) {
1035                 fld.daddr = fld.saddr;
1036 
1037                 if (dev_out)
1038                         dev_put(dev_out);
1039                 err = -EINVAL;
1040                 dev_out = init_net.loopback_dev;
1041                 if (!dev_out->dn_ptr)
1042                         goto out;
1043                 err = -EADDRNOTAVAIL;
1044                 dev_hold(dev_out);
1045                 if (!fld.daddr) {
1046                         fld.daddr =
1047                         fld.saddr = dnet_select_source(dev_out, 0,
1048                                                        RT_SCOPE_HOST);
1049                         if (!fld.daddr)
1050                                 goto out;
1051                 }
1052                 fld.flowidn_oif = LOOPBACK_IFINDEX;
1053                 res.type = RTN_LOCAL;
1054                 goto make_route;
1055         }
1056 
1057         if (decnet_debug_level & 16)
1058                 printk(KERN_DEBUG
1059                        "dn_route_output_slow: initial checks complete."
1060                        " dst=%04x src=%04x oif=%d try_hard=%d\n",
1061                        le16_to_cpu(fld.daddr), le16_to_cpu(fld.saddr),
1062                        fld.flowidn_oif, try_hard);
1063 
1064         /*
1065          * N.B. If the kernel is compiled without router support then
1066          * dn_fib_lookup() will evaluate to non-zero so this if () block
1067          * will always be executed.
1068          */
1069         err = -ESRCH;
1070         if (try_hard || (err = dn_fib_lookup(&fld, &res)) != 0) {
1071                 struct dn_dev *dn_db;
1072                 if (err != -ESRCH)
1073                         goto out;
1074                 /*
1075                  * Here the fallback is basically the standard algorithm for
1076                  * routing in endnodes which is described in the DECnet routing
1077                  * docs
1078                  *
1079                  * If we are not trying hard, look in neighbour cache.
1080                  * The result is tested to ensure that if a specific output
1081                  * device/source address was requested, then we honour that
1082                  * here
1083                  */
1084                 if (!try_hard) {
1085                         neigh = neigh_lookup_nodev(&dn_neigh_table, &init_net, &fld.daddr);
1086                         if (neigh) {
1087                                 if ((oldflp->flowidn_oif &&
1088                                     (neigh->dev->ifindex != oldflp->flowidn_oif)) ||
1089                                     (oldflp->saddr &&
1090                                     (!dn_dev_islocal(neigh->dev,
1091                                                      oldflp->saddr)))) {
1092                                         neigh_release(neigh);
1093                                         neigh = NULL;
1094                                 } else {
1095                                         if (dev_out)
1096                                                 dev_put(dev_out);
1097                                         if (dn_dev_islocal(neigh->dev, fld.daddr)) {
1098                                                 dev_out = init_net.loopback_dev;
1099                                                 res.type = RTN_LOCAL;
1100                                         } else {
1101                                                 dev_out = neigh->dev;
1102                                         }
1103                                         dev_hold(dev_out);
1104                                         goto select_source;
1105                                 }
1106                         }
1107                 }
1108 
1109                 /* Not there? Perhaps its a local address */
1110                 if (dev_out == NULL)
1111                         dev_out = dn_dev_get_default();
1112                 err = -ENODEV;
1113                 if (dev_out == NULL)
1114                         goto out;
1115                 dn_db = rcu_dereference_raw(dev_out->dn_ptr);
1116                 if (!dn_db)
1117                         goto e_inval;
1118                 /* Possible improvement - check all devices for local addr */
1119                 if (dn_dev_islocal(dev_out, fld.daddr)) {
1120                         dev_put(dev_out);
1121                         dev_out = init_net.loopback_dev;
1122                         dev_hold(dev_out);
1123                         res.type = RTN_LOCAL;
1124                         goto select_source;
1125                 }
1126                 /* Not local either.... try sending it to the default router */
1127                 neigh = neigh_clone(dn_db->router);
1128                 BUG_ON(neigh && neigh->dev != dev_out);
1129 
1130                 /* Ok then, we assume its directly connected and move on */
1131 select_source:
1132                 if (neigh)
1133                         gateway = ((struct dn_neigh *)neigh)->addr;
1134                 if (gateway == 0)
1135                         gateway = fld.daddr;
1136                 if (fld.saddr == 0) {
1137                         fld.saddr = dnet_select_source(dev_out, gateway,
1138                                                        res.type == RTN_LOCAL ?
1139                                                        RT_SCOPE_HOST :
1140                                                        RT_SCOPE_LINK);
1141                         if (fld.saddr == 0 && res.type != RTN_LOCAL)
1142                                 goto e_addr;
1143                 }
1144                 fld.flowidn_oif = dev_out->ifindex;
1145                 goto make_route;
1146         }
1147         free_res = 1;
1148 
1149         if (res.type == RTN_NAT)
1150                 goto e_inval;
1151 
1152         if (res.type == RTN_LOCAL) {
1153                 if (!fld.saddr)
1154                         fld.saddr = fld.daddr;
1155                 if (dev_out)
1156                         dev_put(dev_out);
1157                 dev_out = init_net.loopback_dev;
1158                 dev_hold(dev_out);
1159                 if (!dev_out->dn_ptr)
1160                         goto e_inval;
1161                 fld.flowidn_oif = dev_out->ifindex;
1162                 if (res.fi)
1163                         dn_fib_info_put(res.fi);
1164                 res.fi = NULL;
1165                 goto make_route;
1166         }
1167 
1168         if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1169                 dn_fib_select_multipath(&fld, &res);
1170 
1171         /*
1172          * We could add some logic to deal with default routes here and
1173          * get rid of some of the special casing above.
1174          */
1175 
1176         if (!fld.saddr)
1177                 fld.saddr = DN_FIB_RES_PREFSRC(res);
1178 
1179         if (dev_out)
1180                 dev_put(dev_out);
1181         dev_out = DN_FIB_RES_DEV(res);
1182         dev_hold(dev_out);
1183         fld.flowidn_oif = dev_out->ifindex;
1184         gateway = DN_FIB_RES_GW(res);
1185 
1186 make_route:
1187         if (dev_out->flags & IFF_LOOPBACK)
1188                 flags |= RTCF_LOCAL;
1189 
1190         rt = dst_alloc(&dn_dst_ops, dev_out, 1, DST_OBSOLETE_NONE, DST_HOST);
1191         if (rt == NULL)
1192                 goto e_nobufs;
1193 
1194         memset(&rt->fld, 0, sizeof(rt->fld));
1195         rt->fld.saddr        = oldflp->saddr;
1196         rt->fld.daddr        = oldflp->daddr;
1197         rt->fld.flowidn_oif  = oldflp->flowidn_oif;
1198         rt->fld.flowidn_iif  = 0;
1199         rt->fld.flowidn_mark = oldflp->flowidn_mark;
1200 
1201         rt->rt_saddr      = fld.saddr;
1202         rt->rt_daddr      = fld.daddr;
1203         rt->rt_gateway    = gateway ? gateway : fld.daddr;
1204         rt->rt_local_src  = fld.saddr;
1205 
1206         rt->rt_dst_map    = fld.daddr;
1207         rt->rt_src_map    = fld.saddr;
1208 
1209         rt->n = neigh;
1210         neigh = NULL;
1211 
1212         rt->dst.lastuse = jiffies;
1213         rt->dst.output  = dn_output;
1214         rt->dst.input   = dn_rt_bug;
1215         rt->rt_flags      = flags;
1216         if (flags & RTCF_LOCAL)
1217                 rt->dst.input = dn_nsp_rx;
1218 
1219         err = dn_rt_set_next_hop(rt, &res);
1220         if (err)
1221                 goto e_neighbour;
1222 
1223         hash = dn_hash(rt->fld.saddr, rt->fld.daddr);
1224         dn_insert_route(rt, hash, (struct dn_route **)pprt);
1225 
1226 done:
1227         if (neigh)
1228                 neigh_release(neigh);
1229         if (free_res)
1230                 dn_fib_res_put(&res);
1231         if (dev_out)
1232                 dev_put(dev_out);
1233 out:
1234         return err;
1235 
1236 e_addr:
1237         err = -EADDRNOTAVAIL;
1238         goto done;
1239 e_inval:
1240         err = -EINVAL;
1241         goto done;
1242 e_nobufs:
1243         err = -ENOBUFS;
1244         goto done;
1245 e_neighbour:
1246         dst_free(&rt->dst);
1247         goto e_nobufs;
1248 }
1249 
1250 
1251 /*
1252  * N.B. The flags may be moved into the flowi at some future stage.
1253  */
1254 static int __dn_route_output_key(struct dst_entry **pprt, const struct flowidn *flp, int flags)
1255 {
1256         unsigned int hash = dn_hash(flp->saddr, flp->daddr);
1257         struct dn_route *rt = NULL;
1258 
1259         if (!(flags & MSG_TRYHARD)) {
1260                 rcu_read_lock_bh();
1261                 for (rt = rcu_dereference_bh(dn_rt_hash_table[hash].chain); rt;
1262                         rt = rcu_dereference_bh(rt->dst.dn_next)) {
1263                         if ((flp->daddr == rt->fld.daddr) &&
1264                             (flp->saddr == rt->fld.saddr) &&
1265                             (flp->flowidn_mark == rt->fld.flowidn_mark) &&
1266                             dn_is_output_route(rt) &&
1267                             (rt->fld.flowidn_oif == flp->flowidn_oif)) {
1268                                 dst_use(&rt->dst, jiffies);
1269                                 rcu_read_unlock_bh();
1270                                 *pprt = &rt->dst;
1271                                 return 0;
1272                         }
1273                 }
1274                 rcu_read_unlock_bh();
1275         }
1276 
1277         return dn_route_output_slow(pprt, flp, flags);
1278 }
1279 
1280 static int dn_route_output_key(struct dst_entry **pprt, struct flowidn *flp, int flags)
1281 {
1282         int err;
1283 
1284         err = __dn_route_output_key(pprt, flp, flags);
1285         if (err == 0 && flp->flowidn_proto) {
1286                 *pprt = xfrm_lookup(&init_net, *pprt,
1287                                     flowidn_to_flowi(flp), NULL, 0);
1288                 if (IS_ERR(*pprt)) {
1289                         err = PTR_ERR(*pprt);
1290                         *pprt = NULL;
1291                 }
1292         }
1293         return err;
1294 }
1295 
1296 int dn_route_output_sock(struct dst_entry __rcu **pprt, struct flowidn *fl, struct sock *sk, int flags)
1297 {
1298         int err;
1299 
1300         err = __dn_route_output_key(pprt, fl, flags & MSG_TRYHARD);
1301         if (err == 0 && fl->flowidn_proto) {
1302                 *pprt = xfrm_lookup(&init_net, *pprt,
1303                                     flowidn_to_flowi(fl), sk, 0);
1304                 if (IS_ERR(*pprt)) {
1305                         err = PTR_ERR(*pprt);
1306                         *pprt = NULL;
1307                 }
1308         }
1309         return err;
1310 }
1311 
1312 static int dn_route_input_slow(struct sk_buff *skb)
1313 {
1314         struct dn_route *rt = NULL;
1315         struct dn_skb_cb *cb = DN_SKB_CB(skb);
1316         struct net_device *in_dev = skb->dev;
1317         struct net_device *out_dev = NULL;
1318         struct dn_dev *dn_db;
1319         struct neighbour *neigh = NULL;
1320         unsigned int hash;
1321         int flags = 0;
1322         __le16 gateway = 0;
1323         __le16 local_src = 0;
1324         struct flowidn fld = {
1325                 .daddr = cb->dst,
1326                 .saddr = cb->src,
1327                 .flowidn_scope = RT_SCOPE_UNIVERSE,
1328                 .flowidn_mark = skb->mark,
1329                 .flowidn_iif = skb->dev->ifindex,
1330         };
1331         struct dn_fib_res res = { .fi = NULL, .type = RTN_UNREACHABLE };
1332         int err = -EINVAL;
1333         int free_res = 0;
1334 
1335         dev_hold(in_dev);
1336 
1337         if ((dn_db = rcu_dereference(in_dev->dn_ptr)) == NULL)
1338                 goto out;
1339 
1340         /* Zero source addresses are not allowed */
1341         if (fld.saddr == 0)
1342                 goto out;
1343 
1344         /*
1345          * In this case we've just received a packet from a source
1346          * outside ourselves pretending to come from us. We don't
1347          * allow it any further to prevent routing loops, spoofing and
1348          * other nasties. Loopback packets already have the dst attached
1349          * so this only affects packets which have originated elsewhere.
1350          */
1351         err  = -ENOTUNIQ;
1352         if (dn_dev_islocal(in_dev, cb->src))
1353                 goto out;
1354 
1355         err = dn_fib_lookup(&fld, &res);
1356         if (err) {
1357                 if (err != -ESRCH)
1358                         goto out;
1359                 /*
1360                  * Is the destination us ?
1361                  */
1362                 if (!dn_dev_islocal(in_dev, cb->dst))
1363                         goto e_inval;
1364 
1365                 res.type = RTN_LOCAL;
1366         } else {
1367                 __le16 src_map = fld.saddr;
1368                 free_res = 1;
1369 
1370                 out_dev = DN_FIB_RES_DEV(res);
1371                 if (out_dev == NULL) {
1372                         net_crit_ratelimited("Bug in dn_route_input_slow() No output device\n");
1373                         goto e_inval;
1374                 }
1375                 dev_hold(out_dev);
1376 
1377                 if (res.r)
1378                         src_map = fld.saddr; /* no NAT support for now */
1379 
1380                 gateway = DN_FIB_RES_GW(res);
1381                 if (res.type == RTN_NAT) {
1382                         fld.daddr = dn_fib_rules_map_destination(fld.daddr, &res);
1383                         dn_fib_res_put(&res);
1384                         free_res = 0;
1385                         if (dn_fib_lookup(&fld, &res))
1386                                 goto e_inval;
1387                         free_res = 1;
1388                         if (res.type != RTN_UNICAST)
1389                                 goto e_inval;
1390                         flags |= RTCF_DNAT;
1391                         gateway = fld.daddr;
1392                 }
1393                 fld.saddr = src_map;
1394         }
1395 
1396         switch(res.type) {
1397         case RTN_UNICAST:
1398                 /*
1399                  * Forwarding check here, we only check for forwarding
1400                  * being turned off, if you want to only forward intra
1401                  * area, its up to you to set the routing tables up
1402                  * correctly.
1403                  */
1404                 if (dn_db->parms.forwarding == 0)
1405                         goto e_inval;
1406 
1407                 if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1408                         dn_fib_select_multipath(&fld, &res);
1409 
1410                 /*
1411                  * Check for out_dev == in_dev. We use the RTCF_DOREDIRECT
1412                  * flag as a hint to set the intra-ethernet bit when
1413                  * forwarding. If we've got NAT in operation, we don't do
1414                  * this optimisation.
1415                  */
1416                 if (out_dev == in_dev && !(flags & RTCF_NAT))
1417                         flags |= RTCF_DOREDIRECT;
1418 
1419                 local_src = DN_FIB_RES_PREFSRC(res);
1420 
1421         case RTN_BLACKHOLE:
1422         case RTN_UNREACHABLE:
1423                 break;
1424         case RTN_LOCAL:
1425                 flags |= RTCF_LOCAL;
1426                 fld.saddr = cb->dst;
1427                 fld.daddr = cb->src;
1428 
1429                 /* Routing tables gave us a gateway */
1430                 if (gateway)
1431                         goto make_route;
1432 
1433                 /* Packet was intra-ethernet, so we know its on-link */
1434                 if (cb->rt_flags & DN_RT_F_IE) {
1435                         gateway = cb->src;
1436                         goto make_route;
1437                 }
1438 
1439                 /* Use the default router if there is one */
1440                 neigh = neigh_clone(dn_db->router);
1441                 if (neigh) {
1442                         gateway = ((struct dn_neigh *)neigh)->addr;
1443                         goto make_route;
1444                 }
1445 
1446                 /* Close eyes and pray */
1447                 gateway = cb->src;
1448                 goto make_route;
1449         default:
1450                 goto e_inval;
1451         }
1452 
1453 make_route:
1454         rt = dst_alloc(&dn_dst_ops, out_dev, 0, DST_OBSOLETE_NONE, DST_HOST);
1455         if (rt == NULL)
1456                 goto e_nobufs;
1457 
1458         memset(&rt->fld, 0, sizeof(rt->fld));
1459         rt->rt_saddr      = fld.saddr;
1460         rt->rt_daddr      = fld.daddr;
1461         rt->rt_gateway    = fld.daddr;
1462         if (gateway)
1463                 rt->rt_gateway = gateway;
1464         rt->rt_local_src  = local_src ? local_src : rt->rt_saddr;
1465 
1466         rt->rt_dst_map    = fld.daddr;
1467         rt->rt_src_map    = fld.saddr;
1468 
1469         rt->fld.saddr        = cb->src;
1470         rt->fld.daddr        = cb->dst;
1471         rt->fld.flowidn_oif  = 0;
1472         rt->fld.flowidn_iif  = in_dev->ifindex;
1473         rt->fld.flowidn_mark = fld.flowidn_mark;
1474 
1475         rt->n = neigh;
1476         rt->dst.lastuse = jiffies;
1477         rt->dst.output = dn_rt_bug_out;
1478         switch (res.type) {
1479         case RTN_UNICAST:
1480                 rt->dst.input = dn_forward;
1481                 break;
1482         case RTN_LOCAL:
1483                 rt->dst.output = dn_output;
1484                 rt->dst.input = dn_nsp_rx;
1485                 rt->dst.dev = in_dev;
1486                 flags |= RTCF_LOCAL;
1487                 break;
1488         default:
1489         case RTN_UNREACHABLE:
1490         case RTN_BLACKHOLE:
1491                 rt->dst.input = dst_discard;
1492         }
1493         rt->rt_flags = flags;
1494 
1495         err = dn_rt_set_next_hop(rt, &res);
1496         if (err)
1497                 goto e_neighbour;
1498 
1499         hash = dn_hash(rt->fld.saddr, rt->fld.daddr);
1500         dn_insert_route(rt, hash, &rt);
1501         skb_dst_set(skb, &rt->dst);
1502 
1503 done:
1504         if (neigh)
1505                 neigh_release(neigh);
1506         if (free_res)
1507                 dn_fib_res_put(&res);
1508         dev_put(in_dev);
1509         if (out_dev)
1510                 dev_put(out_dev);
1511 out:
1512         return err;
1513 
1514 e_inval:
1515         err = -EINVAL;
1516         goto done;
1517 
1518 e_nobufs:
1519         err = -ENOBUFS;
1520         goto done;
1521 
1522 e_neighbour:
1523         dst_free(&rt->dst);
1524         goto done;
1525 }
1526 
1527 static int dn_route_input(struct sk_buff *skb)
1528 {
1529         struct dn_route *rt;
1530         struct dn_skb_cb *cb = DN_SKB_CB(skb);
1531         unsigned int hash = dn_hash(cb->src, cb->dst);
1532 
1533         if (skb_dst(skb))
1534                 return 0;
1535 
1536         rcu_read_lock();
1537         for(rt = rcu_dereference(dn_rt_hash_table[hash].chain); rt != NULL;
1538             rt = rcu_dereference(rt->dst.dn_next)) {
1539                 if ((rt->fld.saddr == cb->src) &&
1540                     (rt->fld.daddr == cb->dst) &&
1541                     (rt->fld.flowidn_oif == 0) &&
1542                     (rt->fld.flowidn_mark == skb->mark) &&
1543                     (rt->fld.flowidn_iif == cb->iif)) {
1544                         dst_use(&rt->dst, jiffies);
1545                         rcu_read_unlock();
1546                         skb_dst_set(skb, (struct dst_entry *)rt);
1547                         return 0;
1548                 }
1549         }
1550         rcu_read_unlock();
1551 
1552         return dn_route_input_slow(skb);
1553 }
1554 
1555 static int dn_rt_fill_info(struct sk_buff *skb, u32 portid, u32 seq,
1556                            int event, int nowait, unsigned int flags)
1557 {
1558         struct dn_route *rt = (struct dn_route *)skb_dst(skb);
1559         struct rtmsg *r;
1560         struct nlmsghdr *nlh;
1561         long expires;
1562 
1563         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
1564         if (!nlh)
1565                 return -EMSGSIZE;
1566 
1567         r = nlmsg_data(nlh);
1568         r->rtm_family = AF_DECnet;
1569         r->rtm_dst_len = 16;
1570         r->rtm_src_len = 0;
1571         r->rtm_tos = 0;
1572         r->rtm_table = RT_TABLE_MAIN;
1573         r->rtm_type = rt->rt_type;
1574         r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
1575         r->rtm_scope = RT_SCOPE_UNIVERSE;
1576         r->rtm_protocol = RTPROT_UNSPEC;
1577 
1578         if (rt->rt_flags & RTCF_NOTIFY)
1579                 r->rtm_flags |= RTM_F_NOTIFY;
1580 
1581         if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN) < 0 ||
1582             nla_put_le16(skb, RTA_DST, rt->rt_daddr) < 0)
1583                 goto errout;
1584 
1585         if (rt->fld.saddr) {
1586                 r->rtm_src_len = 16;
1587                 if (nla_put_le16(skb, RTA_SRC, rt->fld.saddr) < 0)
1588                         goto errout;
1589         }
1590         if (rt->dst.dev &&
1591             nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex) < 0)
1592                 goto errout;
1593 
1594         /*
1595          * Note to self - change this if input routes reverse direction when
1596          * they deal only with inputs and not with replies like they do
1597          * currently.
1598          */
1599         if (nla_put_le16(skb, RTA_PREFSRC, rt->rt_local_src) < 0)
1600                 goto errout;
1601 
1602         if (rt->rt_daddr != rt->rt_gateway &&
1603             nla_put_le16(skb, RTA_GATEWAY, rt->rt_gateway) < 0)
1604                 goto errout;
1605 
1606         if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
1607                 goto errout;
1608 
1609         expires = rt->dst.expires ? rt->dst.expires - jiffies : 0;
1610         if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires,
1611                                rt->dst.error) < 0)
1612                 goto errout;
1613 
1614         if (dn_is_input_route(rt) &&
1615             nla_put_u32(skb, RTA_IIF, rt->fld.flowidn_iif) < 0)
1616                 goto errout;
1617 
1618         nlmsg_end(skb, nlh);
1619         return 0;
1620 
1621 errout:
1622         nlmsg_cancel(skb, nlh);
1623         return -EMSGSIZE;
1624 }
1625 
1626 const struct nla_policy rtm_dn_policy[RTA_MAX + 1] = {
1627         [RTA_DST]               = { .type = NLA_U16 },
1628         [RTA_SRC]               = { .type = NLA_U16 },
1629         [RTA_IIF]               = { .type = NLA_U32 },
1630         [RTA_OIF]               = { .type = NLA_U32 },
1631         [RTA_GATEWAY]           = { .type = NLA_U16 },
1632         [RTA_PRIORITY]          = { .type = NLA_U32 },
1633         [RTA_PREFSRC]           = { .type = NLA_U16 },
1634         [RTA_METRICS]           = { .type = NLA_NESTED },
1635         [RTA_MULTIPATH]         = { .type = NLA_NESTED },
1636         [RTA_TABLE]             = { .type = NLA_U32 },
1637         [RTA_MARK]              = { .type = NLA_U32 },
1638 };
1639 
1640 /*
1641  * This is called by both endnodes and routers now.
1642  */
1643 static int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
1644 {
1645         struct net *net = sock_net(in_skb->sk);
1646         struct rtmsg *rtm = nlmsg_data(nlh);
1647         struct dn_route *rt = NULL;
1648         struct dn_skb_cb *cb;
1649         int err;
1650         struct sk_buff *skb;
1651         struct flowidn fld;
1652         struct nlattr *tb[RTA_MAX+1];
1653 
1654         if (!net_eq(net, &init_net))
1655                 return -EINVAL;
1656 
1657         err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_dn_policy);
1658         if (err < 0)
1659                 return err;
1660 
1661         memset(&fld, 0, sizeof(fld));
1662         fld.flowidn_proto = DNPROTO_NSP;
1663 
1664         skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1665         if (skb == NULL)
1666                 return -ENOBUFS;
1667         skb_reset_mac_header(skb);
1668         cb = DN_SKB_CB(skb);
1669 
1670         if (tb[RTA_SRC])
1671                 fld.saddr = nla_get_le16(tb[RTA_SRC]);
1672 
1673         if (tb[RTA_DST])
1674                 fld.daddr = nla_get_le16(tb[RTA_DST]);
1675 
1676         if (tb[RTA_IIF])
1677                 fld.flowidn_iif = nla_get_u32(tb[RTA_IIF]);
1678 
1679         if (fld.flowidn_iif) {
1680                 struct net_device *dev;
1681                 dev = __dev_get_by_index(&init_net, fld.flowidn_iif);
1682                 if (!dev || !dev->dn_ptr) {
1683                         kfree_skb(skb);
1684                         return -ENODEV;
1685                 }
1686                 skb->protocol = htons(ETH_P_DNA_RT);
1687                 skb->dev = dev;
1688                 cb->src = fld.saddr;
1689                 cb->dst = fld.daddr;
1690                 local_bh_disable();
1691                 err = dn_route_input(skb);
1692                 local_bh_enable();
1693                 memset(cb, 0, sizeof(struct dn_skb_cb));
1694                 rt = (struct dn_route *)skb_dst(skb);
1695                 if (!err && -rt->dst.error)
1696                         err = rt->dst.error;
1697         } else {
1698                 if (tb[RTA_OIF])
1699                         fld.flowidn_oif = nla_get_u32(tb[RTA_OIF]);
1700 
1701                 err = dn_route_output_key((struct dst_entry **)&rt, &fld, 0);
1702         }
1703 
1704         skb->dev = NULL;
1705         if (err)
1706                 goto out_free;
1707         skb_dst_set(skb, &rt->dst);
1708         if (rtm->rtm_flags & RTM_F_NOTIFY)
1709                 rt->rt_flags |= RTCF_NOTIFY;
1710 
1711         err = dn_rt_fill_info(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, RTM_NEWROUTE, 0, 0);
1712         if (err < 0) {
1713                 err = -EMSGSIZE;
1714                 goto out_free;
1715         }
1716 
1717         return rtnl_unicast(skb, &init_net, NETLINK_CB(in_skb).portid);
1718 
1719 out_free:
1720         kfree_skb(skb);
1721         return err;
1722 }
1723 
1724 /*
1725  * For routers, this is called from dn_fib_dump, but for endnodes its
1726  * called directly from the rtnetlink dispatch table.
1727  */
1728 int dn_cache_dump(struct sk_buff *skb, struct netlink_callback *cb)
1729 {
1730         struct net *net = sock_net(skb->sk);
1731         struct dn_route *rt;
1732         int h, s_h;
1733         int idx, s_idx;
1734         struct rtmsg *rtm;
1735 
1736         if (!net_eq(net, &init_net))
1737                 return 0;
1738 
1739         if (nlmsg_len(cb->nlh) < sizeof(struct rtmsg))
1740                 return -EINVAL;
1741 
1742         rtm = nlmsg_data(cb->nlh);
1743         if (!(rtm->rtm_flags & RTM_F_CLONED))
1744                 return 0;
1745 
1746         s_h = cb->args[0];
1747         s_idx = idx = cb->args[1];
1748         for(h = 0; h <= dn_rt_hash_mask; h++) {
1749                 if (h < s_h)
1750                         continue;
1751                 if (h > s_h)
1752                         s_idx = 0;
1753                 rcu_read_lock_bh();
1754                 for(rt = rcu_dereference_bh(dn_rt_hash_table[h].chain), idx = 0;
1755                         rt;
1756                         rt = rcu_dereference_bh(rt->dst.dn_next), idx++) {
1757                         if (idx < s_idx)
1758                                 continue;
1759                         skb_dst_set(skb, dst_clone(&rt->dst));
1760                         if (dn_rt_fill_info(skb, NETLINK_CB(cb->skb).portid,
1761                                         cb->nlh->nlmsg_seq, RTM_NEWROUTE,
1762                                         1, NLM_F_MULTI) < 0) {
1763                                 skb_dst_drop(skb);
1764                                 rcu_read_unlock_bh();
1765                                 goto done;
1766                         }
1767                         skb_dst_drop(skb);
1768                 }
1769                 rcu_read_unlock_bh();
1770         }
1771 
1772 done:
1773         cb->args[0] = h;
1774         cb->args[1] = idx;
1775         return skb->len;
1776 }
1777 
1778 #ifdef CONFIG_PROC_FS
1779 struct dn_rt_cache_iter_state {
1780         int bucket;
1781 };
1782 
1783 static struct dn_route *dn_rt_cache_get_first(struct seq_file *seq)
1784 {
1785         struct dn_route *rt = NULL;
1786         struct dn_rt_cache_iter_state *s = seq->private;
1787 
1788         for(s->bucket = dn_rt_hash_mask; s->bucket >= 0; --s->bucket) {
1789                 rcu_read_lock_bh();
1790                 rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1791                 if (rt)
1792                         break;
1793                 rcu_read_unlock_bh();
1794         }
1795         return rt;
1796 }
1797 
1798 static struct dn_route *dn_rt_cache_get_next(struct seq_file *seq, struct dn_route *rt)
1799 {
1800         struct dn_rt_cache_iter_state *s = seq->private;
1801 
1802         rt = rcu_dereference_bh(rt->dst.dn_next);
1803         while (!rt) {
1804                 rcu_read_unlock_bh();
1805                 if (--s->bucket < 0)
1806                         break;
1807                 rcu_read_lock_bh();
1808                 rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1809         }
1810         return rt;
1811 }
1812 
1813 static void *dn_rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
1814 {
1815         struct dn_route *rt = dn_rt_cache_get_first(seq);
1816 
1817         if (rt) {
1818                 while(*pos && (rt = dn_rt_cache_get_next(seq, rt)))
1819                         --*pos;
1820         }
1821         return *pos ? NULL : rt;
1822 }
1823 
1824 static void *dn_rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1825 {
1826         struct dn_route *rt = dn_rt_cache_get_next(seq, v);
1827         ++*pos;
1828         return rt;
1829 }
1830 
1831 static void dn_rt_cache_seq_stop(struct seq_file *seq, void *v)
1832 {
1833         if (v)
1834                 rcu_read_unlock_bh();
1835 }
1836 
1837 static int dn_rt_cache_seq_show(struct seq_file *seq, void *v)
1838 {
1839         struct dn_route *rt = v;
1840         char buf1[DN_ASCBUF_LEN], buf2[DN_ASCBUF_LEN];
1841 
1842         seq_printf(seq, "%-8s %-7s %-7s %04d %04d %04d\n",
1843                    rt->dst.dev ? rt->dst.dev->name : "*",
1844                    dn_addr2asc(le16_to_cpu(rt->rt_daddr), buf1),
1845                    dn_addr2asc(le16_to_cpu(rt->rt_saddr), buf2),
1846                    atomic_read(&rt->dst.__refcnt),
1847                    rt->dst.__use, 0);
1848         return 0;
1849 }
1850 
1851 static const struct seq_operations dn_rt_cache_seq_ops = {
1852         .start  = dn_rt_cache_seq_start,
1853         .next   = dn_rt_cache_seq_next,
1854         .stop   = dn_rt_cache_seq_stop,
1855         .show   = dn_rt_cache_seq_show,
1856 };
1857 
1858 static int dn_rt_cache_seq_open(struct inode *inode, struct file *file)
1859 {
1860         return seq_open_private(file, &dn_rt_cache_seq_ops,
1861                         sizeof(struct dn_rt_cache_iter_state));
1862 }
1863 
1864 static const struct file_operations dn_rt_cache_seq_fops = {
1865         .owner   = THIS_MODULE,
1866         .open    = dn_rt_cache_seq_open,
1867         .read    = seq_read,
1868         .llseek  = seq_lseek,
1869         .release = seq_release_private,
1870 };
1871 
1872 #endif /* CONFIG_PROC_FS */
1873 
1874 void __init dn_route_init(void)
1875 {
1876         int i, goal, order;
1877 
1878         dn_dst_ops.kmem_cachep =
1879                 kmem_cache_create("dn_dst_cache", sizeof(struct dn_route), 0,
1880                                   SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
1881         dst_entries_init(&dn_dst_ops);
1882         setup_timer(&dn_route_timer, dn_dst_check_expire, 0);
1883         dn_route_timer.expires = jiffies + decnet_dst_gc_interval * HZ;
1884         add_timer(&dn_route_timer);
1885 
1886         goal = totalram_pages >> (26 - PAGE_SHIFT);
1887 
1888         for(order = 0; (1UL << order) < goal; order++)
1889                 /* NOTHING */;
1890 
1891         /*
1892          * Only want 1024 entries max, since the table is very, very unlikely
1893          * to be larger than that.
1894          */
1895         while(order && ((((1UL << order) * PAGE_SIZE) /
1896                                 sizeof(struct dn_rt_hash_bucket)) >= 2048))
1897                 order--;
1898 
1899         do {
1900                 dn_rt_hash_mask = (1UL << order) * PAGE_SIZE /
1901                         sizeof(struct dn_rt_hash_bucket);
1902                 while(dn_rt_hash_mask & (dn_rt_hash_mask - 1))
1903                         dn_rt_hash_mask--;
1904                 dn_rt_hash_table = (struct dn_rt_hash_bucket *)
1905                         __get_free_pages(GFP_ATOMIC, order);
1906         } while (dn_rt_hash_table == NULL && --order > 0);
1907 
1908         if (!dn_rt_hash_table)
1909                 panic("Failed to allocate DECnet route cache hash table\n");
1910 
1911         printk(KERN_INFO
1912                 "DECnet: Routing cache hash table of %u buckets, %ldKbytes\n",
1913                 dn_rt_hash_mask,
1914                 (long)(dn_rt_hash_mask*sizeof(struct dn_rt_hash_bucket))/1024);
1915 
1916         dn_rt_hash_mask--;
1917         for(i = 0; i <= dn_rt_hash_mask; i++) {
1918                 spin_lock_init(&dn_rt_hash_table[i].lock);
1919                 dn_rt_hash_table[i].chain = NULL;
1920         }
1921 
1922         dn_dst_ops.gc_thresh = (dn_rt_hash_mask + 1);
1923 
1924         proc_create("decnet_cache", S_IRUGO, init_net.proc_net,
1925                     &dn_rt_cache_seq_fops);
1926 
1927 #ifdef CONFIG_DECNET_ROUTER
1928         rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute,
1929                       dn_fib_dump, NULL);
1930 #else
1931         rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute,
1932                       dn_cache_dump, NULL);
1933 #endif
1934 }
1935 
1936 void __exit dn_route_cleanup(void)
1937 {
1938         del_timer(&dn_route_timer);
1939         dn_run_flush(0);
1940 
1941         remove_proc_entry("decnet_cache", init_net.proc_net);
1942         dst_entries_destroy(&dn_dst_ops);
1943 }
1944 
1945 

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