?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
[linux/fpc-iii.git] / net / decnet / dn_route.c
blob324cb9f2f55146a46ef78528fa5ac768e22736b9
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(struct timer_list *unused);
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);
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 void dn_dst_check_expire(struct timer_list *unused)
187 {
188 int i;
189 struct dn_route *rt;
190 struct dn_route __rcu **rtp;
191 unsigned long now = jiffies;
192 unsigned long expire = 120 * HZ;
193
194 for (i = 0; i <= dn_rt_hash_mask; i++) {
195 rtp = &dn_rt_hash_table[i].chain;
196
197 spin_lock(&dn_rt_hash_table[i].lock);
198 while ((rt = rcu_dereference_protected(*rtp,
199 lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) {
200 if (atomic_read(&rt->dst.__refcnt) > 1 ||
201 (now - rt->dst.lastuse) < expire) {
202 rtp = &rt->dst.dn_next;
203 continue;
204 }
205 *rtp = rt->dst.dn_next;
206 rt->dst.dn_next = NULL;
207 dst_dev_put(&rt->dst);
208 dst_release(&rt->dst);
209 }
210 spin_unlock(&dn_rt_hash_table[i].lock);
211
212 if ((jiffies - now) > 0)
213 break;
214 }
215
216 mod_timer(&dn_route_timer, now + decnet_dst_gc_interval * HZ);
217 }
218
219 static int dn_dst_gc(struct dst_ops *ops)
220 {
221 struct dn_route *rt;
222 struct dn_route __rcu **rtp;
223 int i;
224 unsigned long now = jiffies;
225 unsigned long expire = 10 * HZ;
226
227 for (i = 0; i <= dn_rt_hash_mask; i++) {
228
229 spin_lock_bh(&dn_rt_hash_table[i].lock);
230 rtp = &dn_rt_hash_table[i].chain;
231
232 while ((rt = rcu_dereference_protected(*rtp,
233 lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) {
234 if (atomic_read(&rt->dst.__refcnt) > 1 ||
235 (now - rt->dst.lastuse) < expire) {
236 rtp = &rt->dst.dn_next;
237 continue;
238 }
239 *rtp = rt->dst.dn_next;
240 rt->dst.dn_next = NULL;
241 dst_dev_put(&rt->dst);
242 dst_release(&rt->dst);
243 break;
244 }
245 spin_unlock_bh(&dn_rt_hash_table[i].lock);
246 }
247
248 return 0;
249 }
250
251 /*
252 * The decnet standards don't impose a particular minimum mtu, what they
253 * do insist on is that the routing layer accepts a datagram of at least
254 * 230 bytes long. Here we have to subtract the routing header length from
255 * 230 to get the minimum acceptable mtu. If there is no neighbour, then we
256 * assume the worst and use a long header size.
257 *
258 * We update both the mtu and the advertised mss (i.e. the segment size we
259 * advertise to the other end).
260 */
261 static void dn_dst_update_pmtu(struct dst_entry *dst, struct sock *sk,
262 struct sk_buff *skb, u32 mtu)
263 {
264 struct dn_route *rt = (struct dn_route *) dst;
265 struct neighbour *n = rt->n;
266 u32 min_mtu = 230;
267 struct dn_dev *dn;
268
269 dn = n ? rcu_dereference_raw(n->dev->dn_ptr) : NULL;
270
271 if (dn && dn->use_long == 0)
272 min_mtu -= 6;
273 else
274 min_mtu -= 21;
275
276 if (dst_metric(dst, RTAX_MTU) > mtu && mtu >= min_mtu) {
277 if (!(dst_metric_locked(dst, RTAX_MTU))) {
278 dst_metric_set(dst, RTAX_MTU, mtu);
279 dst_set_expires(dst, dn_rt_mtu_expires);
280 }
281 if (!(dst_metric_locked(dst, RTAX_ADVMSS))) {
282 u32 mss = mtu - DN_MAX_NSP_DATA_HEADER;
283 u32 existing_mss = dst_metric_raw(dst, RTAX_ADVMSS);
284 if (!existing_mss || existing_mss > mss)
285 dst_metric_set(dst, RTAX_ADVMSS, mss);
286 }
287 }
288 }
289
290 static void dn_dst_redirect(struct dst_entry *dst, struct sock *sk,
291 struct sk_buff *skb)
292 {
293 }
294
295 /*
296 * When a route has been marked obsolete. (e.g. routing cache flush)
297 */
298 static struct dst_entry *dn_dst_check(struct dst_entry *dst, __u32 cookie)
299 {
300 return NULL;
301 }
302
303 static struct dst_entry *dn_dst_negative_advice(struct dst_entry *dst)
304 {
305 dst_release(dst);
306 return NULL;
307 }
308
309 static void dn_dst_link_failure(struct sk_buff *skb)
310 {
311 }
312
313 static inline int compare_keys(struct flowidn *fl1, struct flowidn *fl2)
314 {
315 return ((fl1->daddr ^ fl2->daddr) |
316 (fl1->saddr ^ fl2->saddr) |
317 (fl1->flowidn_mark ^ fl2->flowidn_mark) |
318 (fl1->flowidn_scope ^ fl2->flowidn_scope) |
319 (fl1->flowidn_oif ^ fl2->flowidn_oif) |
320 (fl1->flowidn_iif ^ fl2->flowidn_iif)) == 0;
321 }
322
323 static int dn_insert_route(struct dn_route *rt, unsigned int hash, struct dn_route **rp)
324 {
325 struct dn_route *rth;
326 struct dn_route __rcu **rthp;
327 unsigned long now = jiffies;
328
329 rthp = &dn_rt_hash_table[hash].chain;
330
331 spin_lock_bh(&dn_rt_hash_table[hash].lock);
332 while ((rth = rcu_dereference_protected(*rthp,
333 lockdep_is_held(&dn_rt_hash_table[hash].lock))) != NULL) {
334 if (compare_keys(&rth->fld, &rt->fld)) {
335 /* Put it first */
336 *rthp = rth->dst.dn_next;
337 rcu_assign_pointer(rth->dst.dn_next,
338 dn_rt_hash_table[hash].chain);
339 rcu_assign_pointer(dn_rt_hash_table[hash].chain, rth);
340
341 dst_hold_and_use(&rth->dst, now);
342 spin_unlock_bh(&dn_rt_hash_table[hash].lock);
343
344 dst_release_immediate(&rt->dst);
345 *rp = rth;
346 return 0;
347 }
348 rthp = &rth->dst.dn_next;
349 }
350
351 rcu_assign_pointer(rt->dst.dn_next, dn_rt_hash_table[hash].chain);
352 rcu_assign_pointer(dn_rt_hash_table[hash].chain, rt);
353
354 dst_hold_and_use(&rt->dst, now);
355 spin_unlock_bh(&dn_rt_hash_table[hash].lock);
356 *rp = rt;
357 return 0;
358 }
359
360 static void dn_run_flush(struct timer_list *unused)
361 {
362 int i;
363 struct dn_route *rt, *next;
364
365 for (i = 0; i < dn_rt_hash_mask; i++) {
366 spin_lock_bh(&dn_rt_hash_table[i].lock);
367
368 if ((rt = xchg((struct dn_route **)&dn_rt_hash_table[i].chain, NULL)) == NULL)
369 goto nothing_to_declare;
370
371 for(; rt; rt = next) {
372 next = rcu_dereference_raw(rt->dst.dn_next);
373 RCU_INIT_POINTER(rt->dst.dn_next, NULL);
374 dst_dev_put(&rt->dst);
375 dst_release(&rt->dst);
376 }
377
378 nothing_to_declare:
379 spin_unlock_bh(&dn_rt_hash_table[i].lock);
380 }
381 }
382
383 static DEFINE_SPINLOCK(dn_rt_flush_lock);
384
385 void dn_rt_cache_flush(int delay)
386 {
387 unsigned long now = jiffies;
388 int user_mode = !in_interrupt();
389
390 if (delay < 0)
391 delay = dn_rt_min_delay;
392
393 spin_lock_bh(&dn_rt_flush_lock);
394
395 if (del_timer(&dn_rt_flush_timer) && delay > 0 && dn_rt_deadline) {
396 long tmo = (long)(dn_rt_deadline - now);
397
398 if (user_mode && tmo < dn_rt_max_delay - dn_rt_min_delay)
399 tmo = 0;
400
401 if (delay > tmo)
402 delay = tmo;
403 }
404
405 if (delay <= 0) {
406 spin_unlock_bh(&dn_rt_flush_lock);
407 dn_run_flush(0);
408 return;
409 }
410
411 if (dn_rt_deadline == 0)
412 dn_rt_deadline = now + dn_rt_max_delay;
413
414 dn_rt_flush_timer.expires = now + delay;
415 add_timer(&dn_rt_flush_timer);
416 spin_unlock_bh(&dn_rt_flush_lock);
417 }
418
419 /**
420 * dn_return_short - Return a short packet to its sender
421 * @skb: The packet to return
422 *
423 */
424 static int dn_return_short(struct sk_buff *skb)
425 {
426 struct dn_skb_cb *cb;
427 unsigned char *ptr;
428 __le16 *src;
429 __le16 *dst;
430
431 /* Add back headers */
432 skb_push(skb, skb->data - skb_network_header(skb));
433
434 if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
435 return NET_RX_DROP;
436
437 cb = DN_SKB_CB(skb);
438 /* Skip packet length and point to flags */
439 ptr = skb->data + 2;
440 *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
441
442 dst = (__le16 *)ptr;
443 ptr += 2;
444 src = (__le16 *)ptr;
445 ptr += 2;
446 *ptr = 0; /* Zero hop count */
447
448 swap(*src, *dst);
449
450 skb->pkt_type = PACKET_OUTGOING;
451 dn_rt_finish_output(skb, NULL, NULL);
452 return NET_RX_SUCCESS;
453 }
454
455 /**
456 * dn_return_long - Return a long packet to its sender
457 * @skb: The long format packet to return
458 *
459 */
460 static int dn_return_long(struct sk_buff *skb)
461 {
462 struct dn_skb_cb *cb;
463 unsigned char *ptr;
464 unsigned char *src_addr, *dst_addr;
465 unsigned char tmp[ETH_ALEN];
466
467 /* Add back all headers */
468 skb_push(skb, skb->data - skb_network_header(skb));
469
470 if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
471 return NET_RX_DROP;
472
473 cb = DN_SKB_CB(skb);
474 /* Ignore packet length and point to flags */
475 ptr = skb->data + 2;
476
477 /* Skip padding */
478 if (*ptr & DN_RT_F_PF) {
479 char padlen = (*ptr & ~DN_RT_F_PF);
480 ptr += padlen;
481 }
482
483 *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
484 ptr += 2;
485 dst_addr = ptr;
486 ptr += 8;
487 src_addr = ptr;
488 ptr += 6;
489 *ptr = 0; /* Zero hop count */
490
491 /* Swap source and destination */
492 memcpy(tmp, src_addr, ETH_ALEN);
493 memcpy(src_addr, dst_addr, ETH_ALEN);
494 memcpy(dst_addr, tmp, ETH_ALEN);
495
496 skb->pkt_type = PACKET_OUTGOING;
497 dn_rt_finish_output(skb, dst_addr, src_addr);
498 return NET_RX_SUCCESS;
499 }
500
501 /**
502 * dn_route_rx_packet - Try and find a route for an incoming packet
503 * @skb: The packet to find a route for
504 *
505 * Returns: result of input function if route is found, error code otherwise
506 */
507 static int dn_route_rx_packet(struct net *net, struct sock *sk, struct sk_buff *skb)
508 {
509 struct dn_skb_cb *cb;
510 int err;
511
512 if ((err = dn_route_input(skb)) == 0)
513 return dst_input(skb);
514
515 cb = DN_SKB_CB(skb);
516 if (decnet_debug_level & 4) {
517 char *devname = skb->dev ? skb->dev->name : "???";
518
519 printk(KERN_DEBUG
520 "DECnet: dn_route_rx_packet: rt_flags=0x%02x dev=%s len=%d src=0x%04hx dst=0x%04hx err=%d type=%d\n",
521 (int)cb->rt_flags, devname, skb->len,
522 le16_to_cpu(cb->src), le16_to_cpu(cb->dst),
523 err, skb->pkt_type);
524 }
525
526 if ((skb->pkt_type == PACKET_HOST) && (cb->rt_flags & DN_RT_F_RQR)) {
527 switch (cb->rt_flags & DN_RT_PKT_MSK) {
528 case DN_RT_PKT_SHORT:
529 return dn_return_short(skb);
530 case DN_RT_PKT_LONG:
531 return dn_return_long(skb);
532 }
533 }
534
535 kfree_skb(skb);
536 return NET_RX_DROP;
537 }
538
539 static int dn_route_rx_long(struct sk_buff *skb)
540 {
541 struct dn_skb_cb *cb = DN_SKB_CB(skb);
542 unsigned char *ptr = skb->data;
543
544 if (!pskb_may_pull(skb, 21)) /* 20 for long header, 1 for shortest nsp */
545 goto drop_it;
546
547 skb_pull(skb, 20);
548 skb_reset_transport_header(skb);
549
550 /* Destination info */
551 ptr += 2;
552 cb->dst = dn_eth2dn(ptr);
553 if (memcmp(ptr, dn_hiord_addr, 4) != 0)
554 goto drop_it;
555 ptr += 6;
556
557
558 /* Source info */
559 ptr += 2;
560 cb->src = dn_eth2dn(ptr);
561 if (memcmp(ptr, dn_hiord_addr, 4) != 0)
562 goto drop_it;
563 ptr += 6;
564 /* Other junk */
565 ptr++;
566 cb->hops = *ptr++; /* Visit Count */
567
568 return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING,
569 &init_net, NULL, skb, skb->dev, NULL,
570 dn_route_rx_packet);
571
572 drop_it:
573 kfree_skb(skb);
574 return NET_RX_DROP;
575 }
576
577
578
579 static int dn_route_rx_short(struct sk_buff *skb)
580 {
581 struct dn_skb_cb *cb = DN_SKB_CB(skb);
582 unsigned char *ptr = skb->data;
583
584 if (!pskb_may_pull(skb, 6)) /* 5 for short header + 1 for shortest nsp */
585 goto drop_it;
586
587 skb_pull(skb, 5);
588 skb_reset_transport_header(skb);
589
590 cb->dst = *(__le16 *)ptr;
591 ptr += 2;
592 cb->src = *(__le16 *)ptr;
593 ptr += 2;
594 cb->hops = *ptr & 0x3f;
595
596 return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING,
597 &init_net, NULL, skb, skb->dev, NULL,
598 dn_route_rx_packet);
599
600 drop_it:
601 kfree_skb(skb);
602 return NET_RX_DROP;
603 }
604
605 static int dn_route_discard(struct net *net, struct sock *sk, struct sk_buff *skb)
606 {
607 /*
608 * I know we drop the packet here, but thats considered success in
609 * this case
610 */
611 kfree_skb(skb);
612 return NET_RX_SUCCESS;
613 }
614
615 static int dn_route_ptp_hello(struct net *net, struct sock *sk, struct sk_buff *skb)
616 {
617 dn_dev_hello(skb);
618 dn_neigh_pointopoint_hello(skb);
619 return NET_RX_SUCCESS;
620 }
621
622 int dn_route_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
623 {
624 struct dn_skb_cb *cb;
625 unsigned char flags = 0;
626 __u16 len = le16_to_cpu(*(__le16 *)skb->data);
627 struct dn_dev *dn = rcu_dereference(dev->dn_ptr);
628 unsigned char padlen = 0;
629
630 if (!net_eq(dev_net(dev), &init_net))
631 goto dump_it;
632
633 if (dn == NULL)
634 goto dump_it;
635
636 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
637 goto out;
638
639 if (!pskb_may_pull(skb, 3))
640 goto dump_it;
641
642 skb_pull(skb, 2);
643
644 if (len > skb->len)
645 goto dump_it;
646
647 skb_trim(skb, len);
648
649 flags = *skb->data;
650
651 cb = DN_SKB_CB(skb);
652 cb->stamp = jiffies;
653 cb->iif = dev->ifindex;
654
655 /*
656 * If we have padding, remove it.
657 */
658 if (flags & DN_RT_F_PF) {
659 padlen = flags & ~DN_RT_F_PF;
660 if (!pskb_may_pull(skb, padlen + 1))
661 goto dump_it;
662 skb_pull(skb, padlen);
663 flags = *skb->data;
664 }
665
666 skb_reset_network_header(skb);
667
668 /*
669 * Weed out future version DECnet
670 */
671 if (flags & DN_RT_F_VER)
672 goto dump_it;
673
674 cb->rt_flags = flags;
675
676 if (decnet_debug_level & 1)
677 printk(KERN_DEBUG
678 "dn_route_rcv: got 0x%02x from %s [%d %d %d]\n",
679 (int)flags, (dev) ? dev->name : "???", len, skb->len,
680 padlen);
681
682 if (flags & DN_RT_PKT_CNTL) {
683 if (unlikely(skb_linearize(skb)))
684 goto dump_it;
685
686 switch (flags & DN_RT_CNTL_MSK) {
687 case DN_RT_PKT_INIT:
688 dn_dev_init_pkt(skb);
689 break;
690 case DN_RT_PKT_VERI:
691 dn_dev_veri_pkt(skb);
692 break;
693 }
694
695 if (dn->parms.state != DN_DEV_S_RU)
696 goto dump_it;
697
698 switch (flags & DN_RT_CNTL_MSK) {
699 case DN_RT_PKT_HELO:
700 return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
701 &init_net, NULL, skb, skb->dev, NULL,
702 dn_route_ptp_hello);
703
704 case DN_RT_PKT_L1RT:
705 case DN_RT_PKT_L2RT:
706 return NF_HOOK(NFPROTO_DECNET, NF_DN_ROUTE,
707 &init_net, NULL, skb, skb->dev, NULL,
708 dn_route_discard);
709 case DN_RT_PKT_ERTH:
710 return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
711 &init_net, NULL, skb, skb->dev, NULL,
712 dn_neigh_router_hello);
713
714 case DN_RT_PKT_EEDH:
715 return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
716 &init_net, NULL, skb, skb->dev, NULL,
717 dn_neigh_endnode_hello);
718 }
719 } else {
720 if (dn->parms.state != DN_DEV_S_RU)
721 goto dump_it;
722
723 skb_pull(skb, 1); /* Pull flags */
724
725 switch (flags & DN_RT_PKT_MSK) {
726 case DN_RT_PKT_LONG:
727 return dn_route_rx_long(skb);
728 case DN_RT_PKT_SHORT:
729 return dn_route_rx_short(skb);
730 }
731 }
732
733 dump_it:
734 kfree_skb(skb);
735 out:
736 return NET_RX_DROP;
737 }
738
739 static int dn_output(struct net *net, struct sock *sk, struct sk_buff *skb)
740 {
741 struct dst_entry *dst = skb_dst(skb);
742 struct dn_route *rt = (struct dn_route *)dst;
743 struct net_device *dev = dst->dev;
744 struct dn_skb_cb *cb = DN_SKB_CB(skb);
745
746 int err = -EINVAL;
747
748 if (rt->n == NULL)
749 goto error;
750
751 skb->dev = dev;
752
753 cb->src = rt->rt_saddr;
754 cb->dst = rt->rt_daddr;
755
756 /*
757 * Always set the Intra-Ethernet bit on all outgoing packets
758 * originated on this node. Only valid flag from upper layers
759 * is return-to-sender-requested. Set hop count to 0 too.
760 */
761 cb->rt_flags &= ~DN_RT_F_RQR;
762 cb->rt_flags |= DN_RT_F_IE;
763 cb->hops = 0;
764
765 return NF_HOOK(NFPROTO_DECNET, NF_DN_LOCAL_OUT,
766 &init_net, sk, skb, NULL, dev,
767 dn_to_neigh_output);
768
769 error:
770 net_dbg_ratelimited("dn_output: This should not happen\n");
771
772 kfree_skb(skb);
773
774 return err;
775 }
776
777 static int dn_forward(struct sk_buff *skb)
778 {
779 struct dn_skb_cb *cb = DN_SKB_CB(skb);
780 struct dst_entry *dst = skb_dst(skb);
781 struct dn_dev *dn_db = rcu_dereference(dst->dev->dn_ptr);
782 struct dn_route *rt;
783 int header_len;
784 struct net_device *dev = skb->dev;
785
786 if (skb->pkt_type != PACKET_HOST)
787 goto drop;
788
789 /* Ensure that we have enough space for headers */
790 rt = (struct dn_route *)skb_dst(skb);
791 header_len = dn_db->use_long ? 21 : 6;
792 if (skb_cow(skb, LL_RESERVED_SPACE(rt->dst.dev)+header_len))
793 goto drop;
794
795 /*
796 * Hop count exceeded.
797 */
798 if (++cb->hops > 30)
799 goto drop;
800
801 skb->dev = rt->dst.dev;
802
803 /*
804 * If packet goes out same interface it came in on, then set
805 * the Intra-Ethernet bit. This has no effect for short
806 * packets, so we don't need to test for them here.
807 */
808 cb->rt_flags &= ~DN_RT_F_IE;
809 if (rt->rt_flags & RTCF_DOREDIRECT)
810 cb->rt_flags |= DN_RT_F_IE;
811
812 return NF_HOOK(NFPROTO_DECNET, NF_DN_FORWARD,
813 &init_net, NULL, skb, dev, skb->dev,
814 dn_to_neigh_output);
815
816 drop:
817 kfree_skb(skb);
818 return NET_RX_DROP;
819 }
820
821 /*
822 * Used to catch bugs. This should never normally get
823 * called.
824 */
825 static int dn_rt_bug_out(struct net *net, struct sock *sk, struct sk_buff *skb)
826 {
827 struct dn_skb_cb *cb = DN_SKB_CB(skb);
828
829 net_dbg_ratelimited("dn_rt_bug: skb from:%04x to:%04x\n",
830 le16_to_cpu(cb->src), le16_to_cpu(cb->dst));
831
832 kfree_skb(skb);
833
834 return NET_RX_DROP;
835 }
836
837 static int dn_rt_bug(struct sk_buff *skb)
838 {
839 struct dn_skb_cb *cb = DN_SKB_CB(skb);
840
841 net_dbg_ratelimited("dn_rt_bug: skb from:%04x to:%04x\n",
842 le16_to_cpu(cb->src), le16_to_cpu(cb->dst));
843
844 kfree_skb(skb);
845
846 return NET_RX_DROP;
847 }
848
849 static unsigned int dn_dst_default_advmss(const struct dst_entry *dst)
850 {
851 return dn_mss_from_pmtu(dst->dev, dst_mtu(dst));
852 }
853
854 static unsigned int dn_dst_mtu(const struct dst_entry *dst)
855 {
856 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
857
858 return mtu ? : dst->dev->mtu;
859 }
860
861 static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst,
862 struct sk_buff *skb,
863 const void *daddr)
864 {
865 return __neigh_lookup_errno(&dn_neigh_table, daddr, dst->dev);
866 }
867
868 static int dn_rt_set_next_hop(struct dn_route *rt, struct dn_fib_res *res)
869 {
870 struct dn_fib_info *fi = res->fi;
871 struct net_device *dev = rt->dst.dev;
872 unsigned int mss_metric;
873 struct neighbour *n;
874
875 if (fi) {
876 if (DN_FIB_RES_GW(*res) &&
877 DN_FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
878 rt->rt_gateway = DN_FIB_RES_GW(*res);
879 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
880 }
881 rt->rt_type = res->type;
882
883 if (dev != NULL && rt->n == NULL) {
884 n = __neigh_lookup_errno(&dn_neigh_table, &rt->rt_gateway, dev);
885 if (IS_ERR(n))
886 return PTR_ERR(n);
887 rt->n = n;
888 }
889
890 if (dst_metric(&rt->dst, RTAX_MTU) > rt->dst.dev->mtu)
891 dst_metric_set(&rt->dst, RTAX_MTU, rt->dst.dev->mtu);
892 mss_metric = dst_metric_raw(&rt->dst, RTAX_ADVMSS);
893 if (mss_metric) {
894 unsigned int mss = dn_mss_from_pmtu(dev, dst_mtu(&rt->dst));
895 if (mss_metric > mss)
896 dst_metric_set(&rt->dst, RTAX_ADVMSS, mss);
897 }
898 return 0;
899 }
900
901 static inline int dn_match_addr(__le16 addr1, __le16 addr2)
902 {
903 __u16 tmp = le16_to_cpu(addr1) ^ le16_to_cpu(addr2);
904 int match = 16;
905 while(tmp) {
906 tmp >>= 1;
907 match--;
908 }
909 return match;
910 }
911
912 static __le16 dnet_select_source(const struct net_device *dev, __le16 daddr, int scope)
913 {
914 __le16 saddr = 0;
915 struct dn_dev *dn_db;
916 struct dn_ifaddr *ifa;
917 int best_match = 0;
918 int ret;
919
920 rcu_read_lock();
921 dn_db = rcu_dereference(dev->dn_ptr);
922 for (ifa = rcu_dereference(dn_db->ifa_list);
923 ifa != NULL;
924 ifa = rcu_dereference(ifa->ifa_next)) {
925 if (ifa->ifa_scope > scope)
926 continue;
927 if (!daddr) {
928 saddr = ifa->ifa_local;
929 break;
930 }
931 ret = dn_match_addr(daddr, ifa->ifa_local);
932 if (ret > best_match)
933 saddr = ifa->ifa_local;
934 if (best_match == 0)
935 saddr = ifa->ifa_local;
936 }
937 rcu_read_unlock();
938
939 return saddr;
940 }
941
942 static inline __le16 __dn_fib_res_prefsrc(struct dn_fib_res *res)
943 {
944 return dnet_select_source(DN_FIB_RES_DEV(*res), DN_FIB_RES_GW(*res), res->scope);
945 }
946
947 static inline __le16 dn_fib_rules_map_destination(__le16 daddr, struct dn_fib_res *res)
948 {
949 __le16 mask = dnet_make_mask(res->prefixlen);
950 return (daddr&~mask)|res->fi->fib_nh->nh_gw;
951 }
952
953 static int dn_route_output_slow(struct dst_entry **pprt, const struct flowidn *oldflp, int try_hard)
954 {
955 struct flowidn fld = {
956 .daddr = oldflp->daddr,
957 .saddr = oldflp->saddr,
958 .flowidn_scope = RT_SCOPE_UNIVERSE,
959 .flowidn_mark = oldflp->flowidn_mark,
960 .flowidn_iif = LOOPBACK_IFINDEX,
961 .flowidn_oif = oldflp->flowidn_oif,
962 };
963 struct dn_route *rt = NULL;
964 struct net_device *dev_out = NULL, *dev;
965 struct neighbour *neigh = NULL;
966 unsigned int hash;
967 unsigned int flags = 0;
968 struct dn_fib_res res = { .fi = NULL, .type = RTN_UNICAST };
969 int err;
970 int free_res = 0;
971 __le16 gateway = 0;
972
973 if (decnet_debug_level & 16)
974 printk(KERN_DEBUG
975 "dn_route_output_slow: dst=%04x src=%04x mark=%d"
976 " iif=%d oif=%d\n", le16_to_cpu(oldflp->daddr),
977 le16_to_cpu(oldflp->saddr),
978 oldflp->flowidn_mark, LOOPBACK_IFINDEX,
979 oldflp->flowidn_oif);
980
981 /* If we have an output interface, verify its a DECnet device */
982 if (oldflp->flowidn_oif) {
983 dev_out = dev_get_by_index(&init_net, oldflp->flowidn_oif);
984 err = -ENODEV;
985 if (dev_out && dev_out->dn_ptr == NULL) {
986 dev_put(dev_out);
987 dev_out = NULL;
988 }
989 if (dev_out == NULL)
990 goto out;
991 }
992
993 /* If we have a source address, verify that its a local address */
994 if (oldflp->saddr) {
995 err = -EADDRNOTAVAIL;
996
997 if (dev_out) {
998 if (dn_dev_islocal(dev_out, oldflp->saddr))
999 goto source_ok;
1000 dev_put(dev_out);
1001 goto out;
1002 }
1003 rcu_read_lock();
1004 for_each_netdev_rcu(&init_net, dev) {
1005 if (!dev->dn_ptr)
1006 continue;
1007 if (!dn_dev_islocal(dev, oldflp->saddr))
1008 continue;
1009 if ((dev->flags & IFF_LOOPBACK) &&
1010 oldflp->daddr &&
1011 !dn_dev_islocal(dev, oldflp->daddr))
1012 continue;
1013
1014 dev_out = dev;
1015 break;
1016 }
1017 rcu_read_unlock();
1018 if (dev_out == NULL)
1019 goto out;
1020 dev_hold(dev_out);
1021 source_ok:
1022 ;
1023 }
1024
1025 /* No destination? Assume its local */
1026 if (!fld.daddr) {
1027 fld.daddr = fld.saddr;
1028
1029 if (dev_out)
1030 dev_put(dev_out);
1031 err = -EINVAL;
1032 dev_out = init_net.loopback_dev;
1033 if (!dev_out->dn_ptr)
1034 goto out;
1035 err = -EADDRNOTAVAIL;
1036 dev_hold(dev_out);
1037 if (!fld.daddr) {
1038 fld.daddr =
1039 fld.saddr = dnet_select_source(dev_out, 0,
1040 RT_SCOPE_HOST);
1041 if (!fld.daddr)
1042 goto out;
1043 }
1044 fld.flowidn_oif = LOOPBACK_IFINDEX;
1045 res.type = RTN_LOCAL;
1046 goto make_route;
1047 }
1048
1049 if (decnet_debug_level & 16)
1050 printk(KERN_DEBUG
1051 "dn_route_output_slow: initial checks complete."
1052 " dst=%04x src=%04x oif=%d try_hard=%d\n",
1053 le16_to_cpu(fld.daddr), le16_to_cpu(fld.saddr),
1054 fld.flowidn_oif, try_hard);
1055
1056 /*
1057 * N.B. If the kernel is compiled without router support then
1058 * dn_fib_lookup() will evaluate to non-zero so this if () block
1059 * will always be executed.
1060 */
1061 err = -ESRCH;
1062 if (try_hard || (err = dn_fib_lookup(&fld, &res)) != 0) {
1063 struct dn_dev *dn_db;
1064 if (err != -ESRCH)
1065 goto out;
1066 /*
1067 * Here the fallback is basically the standard algorithm for
1068 * routing in endnodes which is described in the DECnet routing
1069 * docs
1070 *
1071 * If we are not trying hard, look in neighbour cache.
1072 * The result is tested to ensure that if a specific output
1073 * device/source address was requested, then we honour that
1074 * here
1075 */
1076 if (!try_hard) {
1077 neigh = neigh_lookup_nodev(&dn_neigh_table, &init_net, &fld.daddr);
1078 if (neigh) {
1079 if ((oldflp->flowidn_oif &&
1080 (neigh->dev->ifindex != oldflp->flowidn_oif)) ||
1081 (oldflp->saddr &&
1082 (!dn_dev_islocal(neigh->dev,
1083 oldflp->saddr)))) {
1084 neigh_release(neigh);
1085 neigh = NULL;
1086 } else {
1087 if (dev_out)
1088 dev_put(dev_out);
1089 if (dn_dev_islocal(neigh->dev, fld.daddr)) {
1090 dev_out = init_net.loopback_dev;
1091 res.type = RTN_LOCAL;
1092 } else {
1093 dev_out = neigh->dev;
1094 }
1095 dev_hold(dev_out);
1096 goto select_source;
1097 }
1098 }
1099 }
1100
1101 /* Not there? Perhaps its a local address */
1102 if (dev_out == NULL)
1103 dev_out = dn_dev_get_default();
1104 err = -ENODEV;
1105 if (dev_out == NULL)
1106 goto out;
1107 dn_db = rcu_dereference_raw(dev_out->dn_ptr);
1108 if (!dn_db)
1109 goto e_inval;
1110 /* Possible improvement - check all devices for local addr */
1111 if (dn_dev_islocal(dev_out, fld.daddr)) {
1112 dev_put(dev_out);
1113 dev_out = init_net.loopback_dev;
1114 dev_hold(dev_out);
1115 res.type = RTN_LOCAL;
1116 goto select_source;
1117 }
1118 /* Not local either.... try sending it to the default router */
1119 neigh = neigh_clone(dn_db->router);
1120 BUG_ON(neigh && neigh->dev != dev_out);
1121
1122 /* Ok then, we assume its directly connected and move on */
1123 select_source:
1124 if (neigh)
1125 gateway = ((struct dn_neigh *)neigh)->addr;
1126 if (gateway == 0)
1127 gateway = fld.daddr;
1128 if (fld.saddr == 0) {
1129 fld.saddr = dnet_select_source(dev_out, gateway,
1130 res.type == RTN_LOCAL ?
1131 RT_SCOPE_HOST :
1132 RT_SCOPE_LINK);
1133 if (fld.saddr == 0 && res.type != RTN_LOCAL)
1134 goto e_addr;
1135 }
1136 fld.flowidn_oif = dev_out->ifindex;
1137 goto make_route;
1138 }
1139 free_res = 1;
1140
1141 if (res.type == RTN_NAT)
1142 goto e_inval;
1143
1144 if (res.type == RTN_LOCAL) {
1145 if (!fld.saddr)
1146 fld.saddr = fld.daddr;
1147 if (dev_out)
1148 dev_put(dev_out);
1149 dev_out = init_net.loopback_dev;
1150 dev_hold(dev_out);
1151 if (!dev_out->dn_ptr)
1152 goto e_inval;
1153 fld.flowidn_oif = dev_out->ifindex;
1154 if (res.fi)
1155 dn_fib_info_put(res.fi);
1156 res.fi = NULL;
1157 goto make_route;
1158 }
1159
1160 if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1161 dn_fib_select_multipath(&fld, &res);
1162
1163 /*
1164 * We could add some logic to deal with default routes here and
1165 * get rid of some of the special casing above.
1166 */
1167
1168 if (!fld.saddr)
1169 fld.saddr = DN_FIB_RES_PREFSRC(res);
1170
1171 if (dev_out)
1172 dev_put(dev_out);
1173 dev_out = DN_FIB_RES_DEV(res);
1174 dev_hold(dev_out);
1175 fld.flowidn_oif = dev_out->ifindex;
1176 gateway = DN_FIB_RES_GW(res);
1177
1178 make_route:
1179 if (dev_out->flags & IFF_LOOPBACK)
1180 flags |= RTCF_LOCAL;
1181
1182 rt = dst_alloc(&dn_dst_ops, dev_out, 0, DST_OBSOLETE_NONE, DST_HOST);
1183 if (rt == NULL)
1184 goto e_nobufs;
1185
1186 memset(&rt->fld, 0, sizeof(rt->fld));
1187 rt->fld.saddr = oldflp->saddr;
1188 rt->fld.daddr = oldflp->daddr;
1189 rt->fld.flowidn_oif = oldflp->flowidn_oif;
1190 rt->fld.flowidn_iif = 0;
1191 rt->fld.flowidn_mark = oldflp->flowidn_mark;
1192
1193 rt->rt_saddr = fld.saddr;
1194 rt->rt_daddr = fld.daddr;
1195 rt->rt_gateway = gateway ? gateway : fld.daddr;
1196 rt->rt_local_src = fld.saddr;
1197
1198 rt->rt_dst_map = fld.daddr;
1199 rt->rt_src_map = fld.saddr;
1200
1201 rt->n = neigh;
1202 neigh = NULL;
1203
1204 rt->dst.lastuse = jiffies;
1205 rt->dst.output = dn_output;
1206 rt->dst.input = dn_rt_bug;
1207 rt->rt_flags = flags;
1208 if (flags & RTCF_LOCAL)
1209 rt->dst.input = dn_nsp_rx;
1210
1211 err = dn_rt_set_next_hop(rt, &res);
1212 if (err)
1213 goto e_neighbour;
1214
1215 hash = dn_hash(rt->fld.saddr, rt->fld.daddr);
1216 /* dn_insert_route() increments dst->__refcnt */
1217 dn_insert_route(rt, hash, (struct dn_route **)pprt);
1218
1219 done:
1220 if (neigh)
1221 neigh_release(neigh);
1222 if (free_res)
1223 dn_fib_res_put(&res);
1224 if (dev_out)
1225 dev_put(dev_out);
1226 out:
1227 return err;
1228
1229 e_addr:
1230 err = -EADDRNOTAVAIL;
1231 goto done;
1232 e_inval:
1233 err = -EINVAL;
1234 goto done;
1235 e_nobufs:
1236 err = -ENOBUFS;
1237 goto done;
1238 e_neighbour:
1239 dst_release_immediate(&rt->dst);
1240 goto e_nobufs;
1241 }
1242
1243
1244 /*
1245 * N.B. The flags may be moved into the flowi at some future stage.
1246 */
1247 static int __dn_route_output_key(struct dst_entry **pprt, const struct flowidn *flp, int flags)
1248 {
1249 unsigned int hash = dn_hash(flp->saddr, flp->daddr);
1250 struct dn_route *rt = NULL;
1251
1252 if (!(flags & MSG_TRYHARD)) {
1253 rcu_read_lock_bh();
1254 for (rt = rcu_dereference_bh(dn_rt_hash_table[hash].chain); rt;
1255 rt = rcu_dereference_bh(rt->dst.dn_next)) {
1256 if ((flp->daddr == rt->fld.daddr) &&
1257 (flp->saddr == rt->fld.saddr) &&
1258 (flp->flowidn_mark == rt->fld.flowidn_mark) &&
1259 dn_is_output_route(rt) &&
1260 (rt->fld.flowidn_oif == flp->flowidn_oif)) {
1261 dst_hold_and_use(&rt->dst, jiffies);
1262 rcu_read_unlock_bh();
1263 *pprt = &rt->dst;
1264 return 0;
1265 }
1266 }
1267 rcu_read_unlock_bh();
1268 }
1269
1270 return dn_route_output_slow(pprt, flp, flags);
1271 }
1272
1273 static int dn_route_output_key(struct dst_entry **pprt, struct flowidn *flp, int flags)
1274 {
1275 int err;
1276
1277 err = __dn_route_output_key(pprt, flp, flags);
1278 if (err == 0 && flp->flowidn_proto) {
1279 *pprt = xfrm_lookup(&init_net, *pprt,
1280 flowidn_to_flowi(flp), NULL, 0);
1281 if (IS_ERR(*pprt)) {
1282 err = PTR_ERR(*pprt);
1283 *pprt = NULL;
1284 }
1285 }
1286 return err;
1287 }
1288
1289 int dn_route_output_sock(struct dst_entry __rcu **pprt, struct flowidn *fl, struct sock *sk, int flags)
1290 {
1291 int err;
1292
1293 err = __dn_route_output_key(pprt, fl, flags & MSG_TRYHARD);
1294 if (err == 0 && fl->flowidn_proto) {
1295 *pprt = xfrm_lookup(&init_net, *pprt,
1296 flowidn_to_flowi(fl), sk, 0);
1297 if (IS_ERR(*pprt)) {
1298 err = PTR_ERR(*pprt);
1299 *pprt = NULL;
1300 }
1301 }
1302 return err;
1303 }
1304
1305 static int dn_route_input_slow(struct sk_buff *skb)
1306 {
1307 struct dn_route *rt = NULL;
1308 struct dn_skb_cb *cb = DN_SKB_CB(skb);
1309 struct net_device *in_dev = skb->dev;
1310 struct net_device *out_dev = NULL;
1311 struct dn_dev *dn_db;
1312 struct neighbour *neigh = NULL;
1313 unsigned int hash;
1314 int flags = 0;
1315 __le16 gateway = 0;
1316 __le16 local_src = 0;
1317 struct flowidn fld = {
1318 .daddr = cb->dst,
1319 .saddr = cb->src,
1320 .flowidn_scope = RT_SCOPE_UNIVERSE,
1321 .flowidn_mark = skb->mark,
1322 .flowidn_iif = skb->dev->ifindex,
1323 };
1324 struct dn_fib_res res = { .fi = NULL, .type = RTN_UNREACHABLE };
1325 int err = -EINVAL;
1326 int free_res = 0;
1327
1328 dev_hold(in_dev);
1329
1330 if ((dn_db = rcu_dereference(in_dev->dn_ptr)) == NULL)
1331 goto out;
1332
1333 /* Zero source addresses are not allowed */
1334 if (fld.saddr == 0)
1335 goto out;
1336
1337 /*
1338 * In this case we've just received a packet from a source
1339 * outside ourselves pretending to come from us. We don't
1340 * allow it any further to prevent routing loops, spoofing and
1341 * other nasties. Loopback packets already have the dst attached
1342 * so this only affects packets which have originated elsewhere.
1343 */
1344 err = -ENOTUNIQ;
1345 if (dn_dev_islocal(in_dev, cb->src))
1346 goto out;
1347
1348 err = dn_fib_lookup(&fld, &res);
1349 if (err) {
1350 if (err != -ESRCH)
1351 goto out;
1352 /*
1353 * Is the destination us ?
1354 */
1355 if (!dn_dev_islocal(in_dev, cb->dst))
1356 goto e_inval;
1357
1358 res.type = RTN_LOCAL;
1359 } else {
1360 __le16 src_map = fld.saddr;
1361 free_res = 1;
1362
1363 out_dev = DN_FIB_RES_DEV(res);
1364 if (out_dev == NULL) {
1365 net_crit_ratelimited("Bug in dn_route_input_slow() No output device\n");
1366 goto e_inval;
1367 }
1368 dev_hold(out_dev);
1369
1370 if (res.r)
1371 src_map = fld.saddr; /* no NAT support for now */
1372
1373 gateway = DN_FIB_RES_GW(res);
1374 if (res.type == RTN_NAT) {
1375 fld.daddr = dn_fib_rules_map_destination(fld.daddr, &res);
1376 dn_fib_res_put(&res);
1377 free_res = 0;
1378 if (dn_fib_lookup(&fld, &res))
1379 goto e_inval;
1380 free_res = 1;
1381 if (res.type != RTN_UNICAST)
1382 goto e_inval;
1383 flags |= RTCF_DNAT;
1384 gateway = fld.daddr;
1385 }
1386 fld.saddr = src_map;
1387 }
1388
1389 switch(res.type) {
1390 case RTN_UNICAST:
1391 /*
1392 * Forwarding check here, we only check for forwarding
1393 * being turned off, if you want to only forward intra
1394 * area, its up to you to set the routing tables up
1395 * correctly.
1396 */
1397 if (dn_db->parms.forwarding == 0)
1398 goto e_inval;
1399
1400 if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1401 dn_fib_select_multipath(&fld, &res);
1402
1403 /*
1404 * Check for out_dev == in_dev. We use the RTCF_DOREDIRECT
1405 * flag as a hint to set the intra-ethernet bit when
1406 * forwarding. If we've got NAT in operation, we don't do
1407 * this optimisation.
1408 */
1409 if (out_dev == in_dev && !(flags & RTCF_NAT))
1410 flags |= RTCF_DOREDIRECT;
1411
1412 local_src = DN_FIB_RES_PREFSRC(res);
1413
1414 case RTN_BLACKHOLE:
1415 case RTN_UNREACHABLE:
1416 break;
1417 case RTN_LOCAL:
1418 flags |= RTCF_LOCAL;
1419 fld.saddr = cb->dst;
1420 fld.daddr = cb->src;
1421
1422 /* Routing tables gave us a gateway */
1423 if (gateway)
1424 goto make_route;
1425
1426 /* Packet was intra-ethernet, so we know its on-link */
1427 if (cb->rt_flags & DN_RT_F_IE) {
1428 gateway = cb->src;
1429 goto make_route;
1430 }
1431
1432 /* Use the default router if there is one */
1433 neigh = neigh_clone(dn_db->router);
1434 if (neigh) {
1435 gateway = ((struct dn_neigh *)neigh)->addr;
1436 goto make_route;
1437 }
1438
1439 /* Close eyes and pray */
1440 gateway = cb->src;
1441 goto make_route;
1442 default:
1443 goto e_inval;
1444 }
1445
1446 make_route:
1447 rt = dst_alloc(&dn_dst_ops, out_dev, 1, DST_OBSOLETE_NONE, DST_HOST);
1448 if (rt == NULL)
1449 goto e_nobufs;
1450
1451 memset(&rt->fld, 0, sizeof(rt->fld));
1452 rt->rt_saddr = fld.saddr;
1453 rt->rt_daddr = fld.daddr;
1454 rt->rt_gateway = fld.daddr;
1455 if (gateway)
1456 rt->rt_gateway = gateway;
1457 rt->rt_local_src = local_src ? local_src : rt->rt_saddr;
1458
1459 rt->rt_dst_map = fld.daddr;
1460 rt->rt_src_map = fld.saddr;
1461
1462 rt->fld.saddr = cb->src;
1463 rt->fld.daddr = cb->dst;
1464 rt->fld.flowidn_oif = 0;
1465 rt->fld.flowidn_iif = in_dev->ifindex;
1466 rt->fld.flowidn_mark = fld.flowidn_mark;
1467
1468 rt->n = neigh;
1469 rt->dst.lastuse = jiffies;
1470 rt->dst.output = dn_rt_bug_out;
1471 switch (res.type) {
1472 case RTN_UNICAST:
1473 rt->dst.input = dn_forward;
1474 break;
1475 case RTN_LOCAL:
1476 rt->dst.output = dn_output;
1477 rt->dst.input = dn_nsp_rx;
1478 rt->dst.dev = in_dev;
1479 flags |= RTCF_LOCAL;
1480 break;
1481 default:
1482 case RTN_UNREACHABLE:
1483 case RTN_BLACKHOLE:
1484 rt->dst.input = dst_discard;
1485 }
1486 rt->rt_flags = flags;
1487
1488 err = dn_rt_set_next_hop(rt, &res);
1489 if (err)
1490 goto e_neighbour;
1491
1492 hash = dn_hash(rt->fld.saddr, rt->fld.daddr);
1493 /* dn_insert_route() increments dst->__refcnt */
1494 dn_insert_route(rt, hash, &rt);
1495 skb_dst_set(skb, &rt->dst);
1496
1497 done:
1498 if (neigh)
1499 neigh_release(neigh);
1500 if (free_res)
1501 dn_fib_res_put(&res);
1502 dev_put(in_dev);
1503 if (out_dev)
1504 dev_put(out_dev);
1505 out:
1506 return err;
1507
1508 e_inval:
1509 err = -EINVAL;
1510 goto done;
1511
1512 e_nobufs:
1513 err = -ENOBUFS;
1514 goto done;
1515
1516 e_neighbour:
1517 dst_release_immediate(&rt->dst);
1518 goto done;
1519 }
1520
1521 static int dn_route_input(struct sk_buff *skb)
1522 {
1523 struct dn_route *rt;
1524 struct dn_skb_cb *cb = DN_SKB_CB(skb);
1525 unsigned int hash = dn_hash(cb->src, cb->dst);
1526
1527 if (skb_dst(skb))
1528 return 0;
1529
1530 rcu_read_lock();
1531 for(rt = rcu_dereference(dn_rt_hash_table[hash].chain); rt != NULL;
1532 rt = rcu_dereference(rt->dst.dn_next)) {
1533 if ((rt->fld.saddr == cb->src) &&
1534 (rt->fld.daddr == cb->dst) &&
1535 (rt->fld.flowidn_oif == 0) &&
1536 (rt->fld.flowidn_mark == skb->mark) &&
1537 (rt->fld.flowidn_iif == cb->iif)) {
1538 dst_hold_and_use(&rt->dst, jiffies);
1539 rcu_read_unlock();
1540 skb_dst_set(skb, (struct dst_entry *)rt);
1541 return 0;
1542 }
1543 }
1544 rcu_read_unlock();
1545
1546 return dn_route_input_slow(skb);
1547 }
1548
1549 static int dn_rt_fill_info(struct sk_buff *skb, u32 portid, u32 seq,
1550 int event, int nowait, unsigned int flags)
1551 {
1552 struct dn_route *rt = (struct dn_route *)skb_dst(skb);
1553 struct rtmsg *r;
1554 struct nlmsghdr *nlh;
1555 long expires;
1556
1557 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
1558 if (!nlh)
1559 return -EMSGSIZE;
1560
1561 r = nlmsg_data(nlh);
1562 r->rtm_family = AF_DECnet;
1563 r->rtm_dst_len = 16;
1564 r->rtm_src_len = 0;
1565 r->rtm_tos = 0;
1566 r->rtm_table = RT_TABLE_MAIN;
1567 r->rtm_type = rt->rt_type;
1568 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
1569 r->rtm_scope = RT_SCOPE_UNIVERSE;
1570 r->rtm_protocol = RTPROT_UNSPEC;
1571
1572 if (rt->rt_flags & RTCF_NOTIFY)
1573 r->rtm_flags |= RTM_F_NOTIFY;
1574
1575 if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN) < 0 ||
1576 nla_put_le16(skb, RTA_DST, rt->rt_daddr) < 0)
1577 goto errout;
1578
1579 if (rt->fld.saddr) {
1580 r->rtm_src_len = 16;
1581 if (nla_put_le16(skb, RTA_SRC, rt->fld.saddr) < 0)
1582 goto errout;
1583 }
1584 if (rt->dst.dev &&
1585 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex) < 0)
1586 goto errout;
1587
1588 /*
1589 * Note to self - change this if input routes reverse direction when
1590 * they deal only with inputs and not with replies like they do
1591 * currently.
1592 */
1593 if (nla_put_le16(skb, RTA_PREFSRC, rt->rt_local_src) < 0)
1594 goto errout;
1595
1596 if (rt->rt_daddr != rt->rt_gateway &&
1597 nla_put_le16(skb, RTA_GATEWAY, rt->rt_gateway) < 0)
1598 goto errout;
1599
1600 if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
1601 goto errout;
1602
1603 expires = rt->dst.expires ? rt->dst.expires - jiffies : 0;
1604 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires,
1605 rt->dst.error) < 0)
1606 goto errout;
1607
1608 if (dn_is_input_route(rt) &&
1609 nla_put_u32(skb, RTA_IIF, rt->fld.flowidn_iif) < 0)
1610 goto errout;
1611
1612 nlmsg_end(skb, nlh);
1613 return 0;
1614
1615 errout:
1616 nlmsg_cancel(skb, nlh);
1617 return -EMSGSIZE;
1618 }
1619
1620 const struct nla_policy rtm_dn_policy[RTA_MAX + 1] = {
1621 [RTA_DST] = { .type = NLA_U16 },
1622 [RTA_SRC] = { .type = NLA_U16 },
1623 [RTA_IIF] = { .type = NLA_U32 },
1624 [RTA_OIF] = { .type = NLA_U32 },
1625 [RTA_GATEWAY] = { .type = NLA_U16 },
1626 [RTA_PRIORITY] = { .type = NLA_U32 },
1627 [RTA_PREFSRC] = { .type = NLA_U16 },
1628 [RTA_METRICS] = { .type = NLA_NESTED },
1629 [RTA_MULTIPATH] = { .type = NLA_NESTED },
1630 [RTA_TABLE] = { .type = NLA_U32 },
1631 [RTA_MARK] = { .type = NLA_U32 },
1632 };
1633
1634 /*
1635 * This is called by both endnodes and routers now.
1636 */
1637 static int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
1638 struct netlink_ext_ack *extack)
1639 {
1640 struct net *net = sock_net(in_skb->sk);
1641 struct rtmsg *rtm = nlmsg_data(nlh);
1642 struct dn_route *rt = NULL;
1643 struct dn_skb_cb *cb;
1644 int err;
1645 struct sk_buff *skb;
1646 struct flowidn fld;
1647 struct nlattr *tb[RTA_MAX+1];
1648
1649 if (!net_eq(net, &init_net))
1650 return -EINVAL;
1651
1652 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_dn_policy,
1653 extack);
1654 if (err < 0)
1655 return err;
1656
1657 memset(&fld, 0, sizeof(fld));
1658 fld.flowidn_proto = DNPROTO_NSP;
1659
1660 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1661 if (skb == NULL)
1662 return -ENOBUFS;
1663 skb_reset_mac_header(skb);
1664 cb = DN_SKB_CB(skb);
1665
1666 if (tb[RTA_SRC])
1667 fld.saddr = nla_get_le16(tb[RTA_SRC]);
1668
1669 if (tb[RTA_DST])
1670 fld.daddr = nla_get_le16(tb[RTA_DST]);
1671
1672 if (tb[RTA_IIF])
1673 fld.flowidn_iif = nla_get_u32(tb[RTA_IIF]);
1674
1675 if (fld.flowidn_iif) {
1676 struct net_device *dev;
1677 dev = __dev_get_by_index(&init_net, fld.flowidn_iif);
1678 if (!dev || !dev->dn_ptr) {
1679 kfree_skb(skb);
1680 return -ENODEV;
1681 }
1682 skb->protocol = htons(ETH_P_DNA_RT);
1683 skb->dev = dev;
1684 cb->src = fld.saddr;
1685 cb->dst = fld.daddr;
1686 local_bh_disable();
1687 err = dn_route_input(skb);
1688 local_bh_enable();
1689 memset(cb, 0, sizeof(struct dn_skb_cb));
1690 rt = (struct dn_route *)skb_dst(skb);
1691 if (!err && -rt->dst.error)
1692 err = rt->dst.error;
1693 } else {
1694 if (tb[RTA_OIF])
1695 fld.flowidn_oif = nla_get_u32(tb[RTA_OIF]);
1696
1697 err = dn_route_output_key((struct dst_entry **)&rt, &fld, 0);
1698 }
1699
1700 skb->dev = NULL;
1701 if (err)
1702 goto out_free;
1703 skb_dst_set(skb, &rt->dst);
1704 if (rtm->rtm_flags & RTM_F_NOTIFY)
1705 rt->rt_flags |= RTCF_NOTIFY;
1706
1707 err = dn_rt_fill_info(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, RTM_NEWROUTE, 0, 0);
1708 if (err < 0) {
1709 err = -EMSGSIZE;
1710 goto out_free;
1711 }
1712
1713 return rtnl_unicast(skb, &init_net, NETLINK_CB(in_skb).portid);
1714
1715 out_free:
1716 kfree_skb(skb);
1717 return err;
1718 }
1719
1720 /*
1721 * For routers, this is called from dn_fib_dump, but for endnodes its
1722 * called directly from the rtnetlink dispatch table.
1723 */
1724 int dn_cache_dump(struct sk_buff *skb, struct netlink_callback *cb)
1725 {
1726 struct net *net = sock_net(skb->sk);
1727 struct dn_route *rt;
1728 int h, s_h;
1729 int idx, s_idx;
1730 struct rtmsg *rtm;
1731
1732 if (!net_eq(net, &init_net))
1733 return 0;
1734
1735 if (nlmsg_len(cb->nlh) < sizeof(struct rtmsg))
1736 return -EINVAL;
1737
1738 rtm = nlmsg_data(cb->nlh);
1739 if (!(rtm->rtm_flags & RTM_F_CLONED))
1740 return 0;
1741
1742 s_h = cb->args[0];
1743 s_idx = idx = cb->args[1];
1744 for(h = 0; h <= dn_rt_hash_mask; h++) {
1745 if (h < s_h)
1746 continue;
1747 if (h > s_h)
1748 s_idx = 0;
1749 rcu_read_lock_bh();
1750 for(rt = rcu_dereference_bh(dn_rt_hash_table[h].chain), idx = 0;
1751 rt;
1752 rt = rcu_dereference_bh(rt->dst.dn_next), idx++) {
1753 if (idx < s_idx)
1754 continue;
1755 skb_dst_set(skb, dst_clone(&rt->dst));
1756 if (dn_rt_fill_info(skb, NETLINK_CB(cb->skb).portid,
1757 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
1758 1, NLM_F_MULTI) < 0) {
1759 skb_dst_drop(skb);
1760 rcu_read_unlock_bh();
1761 goto done;
1762 }
1763 skb_dst_drop(skb);
1764 }
1765 rcu_read_unlock_bh();
1766 }
1767
1768 done:
1769 cb->args[0] = h;
1770 cb->args[1] = idx;
1771 return skb->len;
1772 }
1773
1774 #ifdef CONFIG_PROC_FS
1775 struct dn_rt_cache_iter_state {
1776 int bucket;
1777 };
1778
1779 static struct dn_route *dn_rt_cache_get_first(struct seq_file *seq)
1780 {
1781 struct dn_route *rt = NULL;
1782 struct dn_rt_cache_iter_state *s = seq->private;
1783
1784 for(s->bucket = dn_rt_hash_mask; s->bucket >= 0; --s->bucket) {
1785 rcu_read_lock_bh();
1786 rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1787 if (rt)
1788 break;
1789 rcu_read_unlock_bh();
1790 }
1791 return rt;
1792 }
1793
1794 static struct dn_route *dn_rt_cache_get_next(struct seq_file *seq, struct dn_route *rt)
1795 {
1796 struct dn_rt_cache_iter_state *s = seq->private;
1797
1798 rt = rcu_dereference_bh(rt->dst.dn_next);
1799 while (!rt) {
1800 rcu_read_unlock_bh();
1801 if (--s->bucket < 0)
1802 break;
1803 rcu_read_lock_bh();
1804 rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1805 }
1806 return rt;
1807 }
1808
1809 static void *dn_rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
1810 {
1811 struct dn_route *rt = dn_rt_cache_get_first(seq);
1812
1813 if (rt) {
1814 while(*pos && (rt = dn_rt_cache_get_next(seq, rt)))
1815 --*pos;
1816 }
1817 return *pos ? NULL : rt;
1818 }
1819
1820 static void *dn_rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1821 {
1822 struct dn_route *rt = dn_rt_cache_get_next(seq, v);
1823 ++*pos;
1824 return rt;
1825 }
1826
1827 static void dn_rt_cache_seq_stop(struct seq_file *seq, void *v)
1828 {
1829 if (v)
1830 rcu_read_unlock_bh();
1831 }
1832
1833 static int dn_rt_cache_seq_show(struct seq_file *seq, void *v)
1834 {
1835 struct dn_route *rt = v;
1836 char buf1[DN_ASCBUF_LEN], buf2[DN_ASCBUF_LEN];
1837
1838 seq_printf(seq, "%-8s %-7s %-7s %04d %04d %04d\n",
1839 rt->dst.dev ? rt->dst.dev->name : "*",
1840 dn_addr2asc(le16_to_cpu(rt->rt_daddr), buf1),
1841 dn_addr2asc(le16_to_cpu(rt->rt_saddr), buf2),
1842 atomic_read(&rt->dst.__refcnt),
1843 rt->dst.__use, 0);
1844 return 0;
1845 }
1846
1847 static const struct seq_operations dn_rt_cache_seq_ops = {
1848 .start = dn_rt_cache_seq_start,
1849 .next = dn_rt_cache_seq_next,
1850 .stop = dn_rt_cache_seq_stop,
1851 .show = dn_rt_cache_seq_show,
1852 };
1853
1854 static int dn_rt_cache_seq_open(struct inode *inode, struct file *file)
1855 {
1856 return seq_open_private(file, &dn_rt_cache_seq_ops,
1857 sizeof(struct dn_rt_cache_iter_state));
1858 }
1859
1860 static const struct file_operations dn_rt_cache_seq_fops = {
1861 .owner = THIS_MODULE,
1862 .open = dn_rt_cache_seq_open,
1863 .read = seq_read,
1864 .llseek = seq_lseek,
1865 .release = seq_release_private,
1866 };
1867
1868 #endif /* CONFIG_PROC_FS */
1869
1870 void __init dn_route_init(void)
1871 {
1872 int i, goal, order;
1873
1874 dn_dst_ops.kmem_cachep =
1875 kmem_cache_create("dn_dst_cache", sizeof(struct dn_route), 0,
1876 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
1877 dst_entries_init(&dn_dst_ops);
1878 timer_setup(&dn_route_timer, dn_dst_check_expire, 0);
1879 dn_route_timer.expires = jiffies + decnet_dst_gc_interval * HZ;
1880 add_timer(&dn_route_timer);
1881
1882 goal = totalram_pages >> (26 - PAGE_SHIFT);
1883
1884 for(order = 0; (1UL << order) < goal; order++)
1885 /* NOTHING */;
1886
1887 /*
1888 * Only want 1024 entries max, since the table is very, very unlikely
1889 * to be larger than that.
1890 */
1891 while(order && ((((1UL << order) * PAGE_SIZE) /
1892 sizeof(struct dn_rt_hash_bucket)) >= 2048))
1893 order--;
1894
1895 do {
1896 dn_rt_hash_mask = (1UL << order) * PAGE_SIZE /
1897 sizeof(struct dn_rt_hash_bucket);
1898 while(dn_rt_hash_mask & (dn_rt_hash_mask - 1))
1899 dn_rt_hash_mask--;
1900 dn_rt_hash_table = (struct dn_rt_hash_bucket *)
1901 __get_free_pages(GFP_ATOMIC, order);
1902 } while (dn_rt_hash_table == NULL && --order > 0);
1903
1904 if (!dn_rt_hash_table)
1905 panic("Failed to allocate DECnet route cache hash table\n");
1906
1907 printk(KERN_INFO
1908 "DECnet: Routing cache hash table of %u buckets, %ldKbytes\n",
1909 dn_rt_hash_mask,
1910 (long)(dn_rt_hash_mask*sizeof(struct dn_rt_hash_bucket))/1024);
1911
1912 dn_rt_hash_mask--;
1913 for(i = 0; i <= dn_rt_hash_mask; i++) {
1914 spin_lock_init(&dn_rt_hash_table[i].lock);
1915 dn_rt_hash_table[i].chain = NULL;
1916 }
1917
1918 dn_dst_ops.gc_thresh = (dn_rt_hash_mask + 1);
1919
1920 proc_create("decnet_cache", S_IRUGO, init_net.proc_net,
1921 &dn_rt_cache_seq_fops);
1922
1923 #ifdef CONFIG_DECNET_ROUTER
1924 rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute,
1925 dn_fib_dump, 0);
1926 #else
1927 rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute,
1928 dn_cache_dump, 0);
1929 #endif
1930 }
1931
1932 void __exit dn_route_cleanup(void)
1933 {
1934 del_timer(&dn_route_timer);
1935 dn_run_flush(0);
1936
1937 remove_proc_entry("decnet_cache", init_net.proc_net);
1938 dst_entries_destroy(&dn_dst_ops);
1939 }
1940
Linux with added FPC-III support