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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 <asm/errno.h>
81#include <net/net_namespace.h>
82#include <net/netlink.h>
83#include <net/neighbour.h>
84#include <net/dst.h>
85#include <net/flow.h>
86#include <net/fib_rules.h>
87#include <net/dn.h>
88#include <net/dn_dev.h>
89#include <net/dn_nsp.h>
90#include <net/dn_route.h>
91#include <net/dn_neigh.h>
92#include <net/dn_fib.h>
93
94struct dn_rt_hash_bucket
95{
96 struct dn_route __rcu *chain;
97 spinlock_t lock;
98};
99
100extern struct neigh_table dn_neigh_table;
101
102
103static unsigned char dn_hiord_addr[6] = {0xAA,0x00,0x04,0x00,0x00,0x00};
104
105static const int dn_rt_min_delay = 2 * HZ;
106static const int dn_rt_max_delay = 10 * HZ;
107static const int dn_rt_mtu_expires = 10 * 60 * HZ;
108
109static unsigned long dn_rt_deadline;
110
111static int dn_dst_gc(struct dst_ops *ops);
112static struct dst_entry *dn_dst_check(struct dst_entry *, __u32);
113static unsigned int dn_dst_default_advmss(const struct dst_entry *dst);
114static unsigned int dn_dst_default_mtu(const struct dst_entry *dst);
115static void dn_dst_destroy(struct dst_entry *);
116static struct dst_entry *dn_dst_negative_advice(struct dst_entry *);
117static void dn_dst_link_failure(struct sk_buff *);
118static void dn_dst_update_pmtu(struct dst_entry *dst, u32 mtu);
119static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst, const void *daddr);
120static int dn_route_input(struct sk_buff *);
121static void dn_run_flush(unsigned long dummy);
122
123static struct dn_rt_hash_bucket *dn_rt_hash_table;
124static unsigned dn_rt_hash_mask;
125
126static struct timer_list dn_route_timer;
127static DEFINE_TIMER(dn_rt_flush_timer, dn_run_flush, 0, 0);
128int decnet_dst_gc_interval = 2;
129
130static struct dst_ops dn_dst_ops = {
131 .family = PF_DECnet,
132 .protocol = cpu_to_be16(ETH_P_DNA_RT),
133 .gc_thresh = 128,
134 .gc = dn_dst_gc,
135 .check = dn_dst_check,
136 .default_advmss = dn_dst_default_advmss,
137 .default_mtu = dn_dst_default_mtu,
138 .cow_metrics = dst_cow_metrics_generic,
139 .destroy = dn_dst_destroy,
140 .negative_advice = dn_dst_negative_advice,
141 .link_failure = dn_dst_link_failure,
142 .update_pmtu = dn_dst_update_pmtu,
143 .neigh_lookup = dn_dst_neigh_lookup,
144};
145
146static void dn_dst_destroy(struct dst_entry *dst)
147{
148 dst_destroy_metrics_generic(dst);
149}
150
151static __inline__ unsigned dn_hash(__le16 src, __le16 dst)
152{
153 __u16 tmp = (__u16 __force)(src ^ dst);
154 tmp ^= (tmp >> 3);
155 tmp ^= (tmp >> 5);
156 tmp ^= (tmp >> 10);
157 return dn_rt_hash_mask & (unsigned)tmp;
158}
159
160static inline void dnrt_free(struct dn_route *rt)
161{
162 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
163}
164
165static inline void dnrt_drop(struct dn_route *rt)
166{
167 dst_release(&rt->dst);
168 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
169}
170
171static void dn_dst_check_expire(unsigned long dummy)
172{
173 int i;
174 struct dn_route *rt;
175 struct dn_route __rcu **rtp;
176 unsigned long now = jiffies;
177 unsigned long expire = 120 * HZ;
178
179 for (i = 0; i <= dn_rt_hash_mask; i++) {
180 rtp = &dn_rt_hash_table[i].chain;
181
182 spin_lock(&dn_rt_hash_table[i].lock);
183 while ((rt = rcu_dereference_protected(*rtp,
184 lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) {
185 if (atomic_read(&rt->dst.__refcnt) ||
186 (now - rt->dst.lastuse) < expire) {
187 rtp = &rt->dst.dn_next;
188 continue;
189 }
190 *rtp = rt->dst.dn_next;
191 rt->dst.dn_next = NULL;
192 dnrt_free(rt);
193 }
194 spin_unlock(&dn_rt_hash_table[i].lock);
195
196 if ((jiffies - now) > 0)
197 break;
198 }
199
200 mod_timer(&dn_route_timer, now + decnet_dst_gc_interval * HZ);
201}
202
203static int dn_dst_gc(struct dst_ops *ops)
204{
205 struct dn_route *rt;
206 struct dn_route __rcu **rtp;
207 int i;
208 unsigned long now = jiffies;
209 unsigned long expire = 10 * HZ;
210
211 for (i = 0; i <= dn_rt_hash_mask; i++) {
212
213 spin_lock_bh(&dn_rt_hash_table[i].lock);
214 rtp = &dn_rt_hash_table[i].chain;
215
216 while ((rt = rcu_dereference_protected(*rtp,
217 lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) {
218 if (atomic_read(&rt->dst.__refcnt) ||
219 (now - rt->dst.lastuse) < expire) {
220 rtp = &rt->dst.dn_next;
221 continue;
222 }
223 *rtp = rt->dst.dn_next;
224 rt->dst.dn_next = NULL;
225 dnrt_drop(rt);
226 break;
227 }
228 spin_unlock_bh(&dn_rt_hash_table[i].lock);
229 }
230
231 return 0;
232}
233
234/*
235 * The decnet standards don't impose a particular minimum mtu, what they
236 * do insist on is that the routing layer accepts a datagram of at least
237 * 230 bytes long. Here we have to subtract the routing header length from
238 * 230 to get the minimum acceptable mtu. If there is no neighbour, then we
239 * assume the worst and use a long header size.
240 *
241 * We update both the mtu and the advertised mss (i.e. the segment size we
242 * advertise to the other end).
243 */
244static void dn_dst_update_pmtu(struct dst_entry *dst, u32 mtu)
245{
246 struct neighbour *n = dst_get_neighbour(dst);
247 u32 min_mtu = 230;
248 struct dn_dev *dn;
249
250 dn = n ? rcu_dereference_raw(n->dev->dn_ptr) : NULL;
251
252 if (dn && dn->use_long == 0)
253 min_mtu -= 6;
254 else
255 min_mtu -= 21;
256
257 if (dst_metric(dst, RTAX_MTU) > mtu && mtu >= min_mtu) {
258 if (!(dst_metric_locked(dst, RTAX_MTU))) {
259 dst_metric_set(dst, RTAX_MTU, mtu);
260 dst_set_expires(dst, dn_rt_mtu_expires);
261 }
262 if (!(dst_metric_locked(dst, RTAX_ADVMSS))) {
263 u32 mss = mtu - DN_MAX_NSP_DATA_HEADER;
264 u32 existing_mss = dst_metric_raw(dst, RTAX_ADVMSS);
265 if (!existing_mss || existing_mss > mss)
266 dst_metric_set(dst, RTAX_ADVMSS, mss);
267 }
268 }
269}
270
271/*
272 * When a route has been marked obsolete. (e.g. routing cache flush)
273 */
274static struct dst_entry *dn_dst_check(struct dst_entry *dst, __u32 cookie)
275{
276 return NULL;
277}
278
279static struct dst_entry *dn_dst_negative_advice(struct dst_entry *dst)
280{
281 dst_release(dst);
282 return NULL;
283}
284
285static void dn_dst_link_failure(struct sk_buff *skb)
286{
287}
288
289static inline int compare_keys(struct flowidn *fl1, struct flowidn *fl2)
290{
291 return ((fl1->daddr ^ fl2->daddr) |
292 (fl1->saddr ^ fl2->saddr) |
293 (fl1->flowidn_mark ^ fl2->flowidn_mark) |
294 (fl1->flowidn_scope ^ fl2->flowidn_scope) |
295 (fl1->flowidn_oif ^ fl2->flowidn_oif) |
296 (fl1->flowidn_iif ^ fl2->flowidn_iif)) == 0;
297}
298
299static int dn_insert_route(struct dn_route *rt, unsigned hash, struct dn_route **rp)
300{
301 struct dn_route *rth;
302 struct dn_route __rcu **rthp;
303 unsigned long now = jiffies;
304
305 rthp = &dn_rt_hash_table[hash].chain;
306
307 spin_lock_bh(&dn_rt_hash_table[hash].lock);
308 while ((rth = rcu_dereference_protected(*rthp,
309 lockdep_is_held(&dn_rt_hash_table[hash].lock))) != NULL) {
310 if (compare_keys(&rth->fld, &rt->fld)) {
311 /* Put it first */
312 *rthp = rth->dst.dn_next;
313 rcu_assign_pointer(rth->dst.dn_next,
314 dn_rt_hash_table[hash].chain);
315 rcu_assign_pointer(dn_rt_hash_table[hash].chain, rth);
316
317 dst_use(&rth->dst, now);
318 spin_unlock_bh(&dn_rt_hash_table[hash].lock);
319
320 dnrt_drop(rt);
321 *rp = rth;
322 return 0;
323 }
324 rthp = &rth->dst.dn_next;
325 }
326
327 rcu_assign_pointer(rt->dst.dn_next, dn_rt_hash_table[hash].chain);
328 rcu_assign_pointer(dn_rt_hash_table[hash].chain, rt);
329
330 dst_use(&rt->dst, now);
331 spin_unlock_bh(&dn_rt_hash_table[hash].lock);
332 *rp = rt;
333 return 0;
334}
335
336static void dn_run_flush(unsigned long dummy)
337{
338 int i;
339 struct dn_route *rt, *next;
340
341 for (i = 0; i < dn_rt_hash_mask; i++) {
342 spin_lock_bh(&dn_rt_hash_table[i].lock);
343
344 if ((rt = xchg((struct dn_route **)&dn_rt_hash_table[i].chain, NULL)) == NULL)
345 goto nothing_to_declare;
346
347 for(; rt; rt = next) {
348 next = rcu_dereference_raw(rt->dst.dn_next);
349 RCU_INIT_POINTER(rt->dst.dn_next, NULL);
350 dst_free((struct dst_entry *)rt);
351 }
352
353nothing_to_declare:
354 spin_unlock_bh(&dn_rt_hash_table[i].lock);
355 }
356}
357
358static DEFINE_SPINLOCK(dn_rt_flush_lock);
359
360void dn_rt_cache_flush(int delay)
361{
362 unsigned long now = jiffies;
363 int user_mode = !in_interrupt();
364
365 if (delay < 0)
366 delay = dn_rt_min_delay;
367
368 spin_lock_bh(&dn_rt_flush_lock);
369
370 if (del_timer(&dn_rt_flush_timer) && delay > 0 && dn_rt_deadline) {
371 long tmo = (long)(dn_rt_deadline - now);
372
373 if (user_mode && tmo < dn_rt_max_delay - dn_rt_min_delay)
374 tmo = 0;
375
376 if (delay > tmo)
377 delay = tmo;
378 }
379
380 if (delay <= 0) {
381 spin_unlock_bh(&dn_rt_flush_lock);
382 dn_run_flush(0);
383 return;
384 }
385
386 if (dn_rt_deadline == 0)
387 dn_rt_deadline = now + dn_rt_max_delay;
388
389 dn_rt_flush_timer.expires = now + delay;
390 add_timer(&dn_rt_flush_timer);
391 spin_unlock_bh(&dn_rt_flush_lock);
392}
393
394/**
395 * dn_return_short - Return a short packet to its sender
396 * @skb: The packet to return
397 *
398 */
399static int dn_return_short(struct sk_buff *skb)
400{
401 struct dn_skb_cb *cb;
402 unsigned char *ptr;
403 __le16 *src;
404 __le16 *dst;
405
406 /* Add back headers */
407 skb_push(skb, skb->data - skb_network_header(skb));
408
409 if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
410 return NET_RX_DROP;
411
412 cb = DN_SKB_CB(skb);
413 /* Skip packet length and point to flags */
414 ptr = skb->data + 2;
415 *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
416
417 dst = (__le16 *)ptr;
418 ptr += 2;
419 src = (__le16 *)ptr;
420 ptr += 2;
421 *ptr = 0; /* Zero hop count */
422
423 swap(*src, *dst);
424
425 skb->pkt_type = PACKET_OUTGOING;
426 dn_rt_finish_output(skb, NULL, NULL);
427 return NET_RX_SUCCESS;
428}
429
430/**
431 * dn_return_long - Return a long packet to its sender
432 * @skb: The long format packet to return
433 *
434 */
435static int dn_return_long(struct sk_buff *skb)
436{
437 struct dn_skb_cb *cb;
438 unsigned char *ptr;
439 unsigned char *src_addr, *dst_addr;
440 unsigned char tmp[ETH_ALEN];
441
442 /* Add back all headers */
443 skb_push(skb, skb->data - skb_network_header(skb));
444
445 if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
446 return NET_RX_DROP;
447
448 cb = DN_SKB_CB(skb);
449 /* Ignore packet length and point to flags */
450 ptr = skb->data + 2;
451
452 /* Skip padding */
453 if (*ptr & DN_RT_F_PF) {
454 char padlen = (*ptr & ~DN_RT_F_PF);
455 ptr += padlen;
456 }
457
458 *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
459 ptr += 2;
460 dst_addr = ptr;
461 ptr += 8;
462 src_addr = ptr;
463 ptr += 6;
464 *ptr = 0; /* Zero hop count */
465
466 /* Swap source and destination */
467 memcpy(tmp, src_addr, ETH_ALEN);
468 memcpy(src_addr, dst_addr, ETH_ALEN);
469 memcpy(dst_addr, tmp, ETH_ALEN);
470
471 skb->pkt_type = PACKET_OUTGOING;
472 dn_rt_finish_output(skb, dst_addr, src_addr);
473 return NET_RX_SUCCESS;
474}
475
476/**
477 * dn_route_rx_packet - Try and find a route for an incoming packet
478 * @skb: The packet to find a route for
479 *
480 * Returns: result of input function if route is found, error code otherwise
481 */
482static int dn_route_rx_packet(struct sk_buff *skb)
483{
484 struct dn_skb_cb *cb;
485 int err;
486
487 if ((err = dn_route_input(skb)) == 0)
488 return dst_input(skb);
489
490 cb = DN_SKB_CB(skb);
491 if (decnet_debug_level & 4) {
492 char *devname = skb->dev ? skb->dev->name : "???";
493
494 printk(KERN_DEBUG
495 "DECnet: dn_route_rx_packet: rt_flags=0x%02x dev=%s len=%d src=0x%04hx dst=0x%04hx err=%d type=%d\n",
496 (int)cb->rt_flags, devname, skb->len,
497 le16_to_cpu(cb->src), le16_to_cpu(cb->dst),
498 err, skb->pkt_type);
499 }
500
501 if ((skb->pkt_type == PACKET_HOST) && (cb->rt_flags & DN_RT_F_RQR)) {
502 switch (cb->rt_flags & DN_RT_PKT_MSK) {
503 case DN_RT_PKT_SHORT:
504 return dn_return_short(skb);
505 case DN_RT_PKT_LONG:
506 return dn_return_long(skb);
507 }
508 }
509
510 kfree_skb(skb);
511 return NET_RX_DROP;
512}
513
514static int dn_route_rx_long(struct sk_buff *skb)
515{
516 struct dn_skb_cb *cb = DN_SKB_CB(skb);
517 unsigned char *ptr = skb->data;
518
519 if (!pskb_may_pull(skb, 21)) /* 20 for long header, 1 for shortest nsp */
520 goto drop_it;
521
522 skb_pull(skb, 20);
523 skb_reset_transport_header(skb);
524
525 /* Destination info */
526 ptr += 2;
527 cb->dst = dn_eth2dn(ptr);
528 if (memcmp(ptr, dn_hiord_addr, 4) != 0)
529 goto drop_it;
530 ptr += 6;
531
532
533 /* Source info */
534 ptr += 2;
535 cb->src = dn_eth2dn(ptr);
536 if (memcmp(ptr, dn_hiord_addr, 4) != 0)
537 goto drop_it;
538 ptr += 6;
539 /* Other junk */
540 ptr++;
541 cb->hops = *ptr++; /* Visit Count */
542
543 return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING, skb, skb->dev, NULL,
544 dn_route_rx_packet);
545
546drop_it:
547 kfree_skb(skb);
548 return NET_RX_DROP;
549}
550
551
552
553static int dn_route_rx_short(struct sk_buff *skb)
554{
555 struct dn_skb_cb *cb = DN_SKB_CB(skb);
556 unsigned char *ptr = skb->data;
557
558 if (!pskb_may_pull(skb, 6)) /* 5 for short header + 1 for shortest nsp */
559 goto drop_it;
560
561 skb_pull(skb, 5);
562 skb_reset_transport_header(skb);
563
564 cb->dst = *(__le16 *)ptr;
565 ptr += 2;
566 cb->src = *(__le16 *)ptr;
567 ptr += 2;
568 cb->hops = *ptr & 0x3f;
569
570 return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING, skb, skb->dev, NULL,
571 dn_route_rx_packet);
572
573drop_it:
574 kfree_skb(skb);
575 return NET_RX_DROP;
576}
577
578static int dn_route_discard(struct sk_buff *skb)
579{
580 /*
581 * I know we drop the packet here, but thats considered success in
582 * this case
583 */
584 kfree_skb(skb);
585 return NET_RX_SUCCESS;
586}
587
588static int dn_route_ptp_hello(struct sk_buff *skb)
589{
590 dn_dev_hello(skb);
591 dn_neigh_pointopoint_hello(skb);
592 return NET_RX_SUCCESS;
593}
594
595int dn_route_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
596{
597 struct dn_skb_cb *cb;
598 unsigned char flags = 0;
599 __u16 len = le16_to_cpu(*(__le16 *)skb->data);
600 struct dn_dev *dn = rcu_dereference(dev->dn_ptr);
601 unsigned char padlen = 0;
602
603 if (!net_eq(dev_net(dev), &init_net))
604 goto dump_it;
605
606 if (dn == NULL)
607 goto dump_it;
608
609 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
610 goto out;
611
612 if (!pskb_may_pull(skb, 3))
613 goto dump_it;
614
615 skb_pull(skb, 2);
616
617 if (len > skb->len)
618 goto dump_it;
619
620 skb_trim(skb, len);
621
622 flags = *skb->data;
623
624 cb = DN_SKB_CB(skb);
625 cb->stamp = jiffies;
626 cb->iif = dev->ifindex;
627
628 /*
629 * If we have padding, remove it.
630 */
631 if (flags & DN_RT_F_PF) {
632 padlen = flags & ~DN_RT_F_PF;
633 if (!pskb_may_pull(skb, padlen + 1))
634 goto dump_it;
635 skb_pull(skb, padlen);
636 flags = *skb->data;
637 }
638
639 skb_reset_network_header(skb);
640
641 /*
642 * Weed out future version DECnet
643 */
644 if (flags & DN_RT_F_VER)
645 goto dump_it;
646
647 cb->rt_flags = flags;
648
649 if (decnet_debug_level & 1)
650 printk(KERN_DEBUG
651 "dn_route_rcv: got 0x%02x from %s [%d %d %d]\n",
652 (int)flags, (dev) ? dev->name : "???", len, skb->len,
653 padlen);
654
655 if (flags & DN_RT_PKT_CNTL) {
656 if (unlikely(skb_linearize(skb)))
657 goto dump_it;
658
659 switch (flags & DN_RT_CNTL_MSK) {
660 case DN_RT_PKT_INIT:
661 dn_dev_init_pkt(skb);
662 break;
663 case DN_RT_PKT_VERI:
664 dn_dev_veri_pkt(skb);
665 break;
666 }
667
668 if (dn->parms.state != DN_DEV_S_RU)
669 goto dump_it;
670
671 switch (flags & DN_RT_CNTL_MSK) {
672 case DN_RT_PKT_HELO:
673 return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
674 skb, skb->dev, NULL,
675 dn_route_ptp_hello);
676
677 case DN_RT_PKT_L1RT:
678 case DN_RT_PKT_L2RT:
679 return NF_HOOK(NFPROTO_DECNET, NF_DN_ROUTE,
680 skb, skb->dev, NULL,
681 dn_route_discard);
682 case DN_RT_PKT_ERTH:
683 return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
684 skb, skb->dev, NULL,
685 dn_neigh_router_hello);
686
687 case DN_RT_PKT_EEDH:
688 return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
689 skb, skb->dev, NULL,
690 dn_neigh_endnode_hello);
691 }
692 } else {
693 if (dn->parms.state != DN_DEV_S_RU)
694 goto dump_it;
695
696 skb_pull(skb, 1); /* Pull flags */
697
698 switch (flags & DN_RT_PKT_MSK) {
699 case DN_RT_PKT_LONG:
700 return dn_route_rx_long(skb);
701 case DN_RT_PKT_SHORT:
702 return dn_route_rx_short(skb);
703 }
704 }
705
706dump_it:
707 kfree_skb(skb);
708out:
709 return NET_RX_DROP;
710}
711
712static int dn_to_neigh_output(struct sk_buff *skb)
713{
714 struct dst_entry *dst = skb_dst(skb);
715 struct neighbour *n = dst_get_neighbour(dst);
716
717 return n->output(n, skb);
718}
719
720static int dn_output(struct sk_buff *skb)
721{
722 struct dst_entry *dst = skb_dst(skb);
723 struct dn_route *rt = (struct dn_route *)dst;
724 struct net_device *dev = dst->dev;
725 struct dn_skb_cb *cb = DN_SKB_CB(skb);
726 struct neighbour *neigh;
727
728 int err = -EINVAL;
729
730 if ((neigh = dst_get_neighbour(dst)) == NULL)
731 goto error;
732
733 skb->dev = dev;
734
735 cb->src = rt->rt_saddr;
736 cb->dst = rt->rt_daddr;
737
738 /*
739 * Always set the Intra-Ethernet bit on all outgoing packets
740 * originated on this node. Only valid flag from upper layers
741 * is return-to-sender-requested. Set hop count to 0 too.
742 */
743 cb->rt_flags &= ~DN_RT_F_RQR;
744 cb->rt_flags |= DN_RT_F_IE;
745 cb->hops = 0;
746
747 return NF_HOOK(NFPROTO_DECNET, NF_DN_LOCAL_OUT, skb, NULL, dev,
748 dn_to_neigh_output);
749
750error:
751 if (net_ratelimit())
752 printk(KERN_DEBUG "dn_output: This should not happen\n");
753
754 kfree_skb(skb);
755
756 return err;
757}
758
759static int dn_forward(struct sk_buff *skb)
760{
761 struct dn_skb_cb *cb = DN_SKB_CB(skb);
762 struct dst_entry *dst = skb_dst(skb);
763 struct dn_dev *dn_db = rcu_dereference(dst->dev->dn_ptr);
764 struct dn_route *rt;
765 int header_len;
766#ifdef CONFIG_NETFILTER
767 struct net_device *dev = skb->dev;
768#endif
769
770 if (skb->pkt_type != PACKET_HOST)
771 goto drop;
772
773 /* Ensure that we have enough space for headers */
774 rt = (struct dn_route *)skb_dst(skb);
775 header_len = dn_db->use_long ? 21 : 6;
776 if (skb_cow(skb, LL_RESERVED_SPACE(rt->dst.dev)+header_len))
777 goto drop;
778
779 /*
780 * Hop count exceeded.
781 */
782 if (++cb->hops > 30)
783 goto drop;
784
785 skb->dev = rt->dst.dev;
786
787 /*
788 * If packet goes out same interface it came in on, then set
789 * the Intra-Ethernet bit. This has no effect for short
790 * packets, so we don't need to test for them here.
791 */
792 cb->rt_flags &= ~DN_RT_F_IE;
793 if (rt->rt_flags & RTCF_DOREDIRECT)
794 cb->rt_flags |= DN_RT_F_IE;
795
796 return NF_HOOK(NFPROTO_DECNET, NF_DN_FORWARD, skb, dev, skb->dev,
797 dn_to_neigh_output);
798
799drop:
800 kfree_skb(skb);
801 return NET_RX_DROP;
802}
803
804/*
805 * Used to catch bugs. This should never normally get
806 * called.
807 */
808static int dn_rt_bug(struct sk_buff *skb)
809{
810 if (net_ratelimit()) {
811 struct dn_skb_cb *cb = DN_SKB_CB(skb);
812
813 printk(KERN_DEBUG "dn_rt_bug: skb from:%04x to:%04x\n",
814 le16_to_cpu(cb->src), le16_to_cpu(cb->dst));
815 }
816
817 kfree_skb(skb);
818
819 return NET_RX_DROP;
820}
821
822static unsigned int dn_dst_default_advmss(const struct dst_entry *dst)
823{
824 return dn_mss_from_pmtu(dst->dev, dst_mtu(dst));
825}
826
827static unsigned int dn_dst_default_mtu(const struct dst_entry *dst)
828{
829 return dst->dev->mtu;
830}
831
832static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst, const void *daddr)
833{
834 return __neigh_lookup_errno(&dn_neigh_table, daddr, dst->dev);
835}
836
837static int dn_rt_set_next_hop(struct dn_route *rt, struct dn_fib_res *res)
838{
839 struct dn_fib_info *fi = res->fi;
840 struct net_device *dev = rt->dst.dev;
841 unsigned int mss_metric;
842 struct neighbour *n;
843
844 if (fi) {
845 if (DN_FIB_RES_GW(*res) &&
846 DN_FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
847 rt->rt_gateway = DN_FIB_RES_GW(*res);
848 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
849 }
850 rt->rt_type = res->type;
851
852 if (dev != NULL && dst_get_neighbour(&rt->dst) == NULL) {
853 n = __neigh_lookup_errno(&dn_neigh_table, &rt->rt_gateway, dev);
854 if (IS_ERR(n))
855 return PTR_ERR(n);
856 dst_set_neighbour(&rt->dst, n);
857 }
858
859 if (dst_metric(&rt->dst, RTAX_MTU) > rt->dst.dev->mtu)
860 dst_metric_set(&rt->dst, RTAX_MTU, rt->dst.dev->mtu);
861 mss_metric = dst_metric_raw(&rt->dst, RTAX_ADVMSS);
862 if (mss_metric) {
863 unsigned int mss = dn_mss_from_pmtu(dev, dst_mtu(&rt->dst));
864 if (mss_metric > mss)
865 dst_metric_set(&rt->dst, RTAX_ADVMSS, mss);
866 }
867 return 0;
868}
869
870static inline int dn_match_addr(__le16 addr1, __le16 addr2)
871{
872 __u16 tmp = le16_to_cpu(addr1) ^ le16_to_cpu(addr2);
873 int match = 16;
874 while(tmp) {
875 tmp >>= 1;
876 match--;
877 }
878 return match;
879}
880
881static __le16 dnet_select_source(const struct net_device *dev, __le16 daddr, int scope)
882{
883 __le16 saddr = 0;
884 struct dn_dev *dn_db;
885 struct dn_ifaddr *ifa;
886 int best_match = 0;
887 int ret;
888
889 rcu_read_lock();
890 dn_db = rcu_dereference(dev->dn_ptr);
891 for (ifa = rcu_dereference(dn_db->ifa_list);
892 ifa != NULL;
893 ifa = rcu_dereference(ifa->ifa_next)) {
894 if (ifa->ifa_scope > scope)
895 continue;
896 if (!daddr) {
897 saddr = ifa->ifa_local;
898 break;
899 }
900 ret = dn_match_addr(daddr, ifa->ifa_local);
901 if (ret > best_match)
902 saddr = ifa->ifa_local;
903 if (best_match == 0)
904 saddr = ifa->ifa_local;
905 }
906 rcu_read_unlock();
907
908 return saddr;
909}
910
911static inline __le16 __dn_fib_res_prefsrc(struct dn_fib_res *res)
912{
913 return dnet_select_source(DN_FIB_RES_DEV(*res), DN_FIB_RES_GW(*res), res->scope);
914}
915
916static inline __le16 dn_fib_rules_map_destination(__le16 daddr, struct dn_fib_res *res)
917{
918 __le16 mask = dnet_make_mask(res->prefixlen);
919 return (daddr&~mask)|res->fi->fib_nh->nh_gw;
920}
921
922static int dn_route_output_slow(struct dst_entry **pprt, const struct flowidn *oldflp, int try_hard)
923{
924 struct flowidn fld = {
925 .daddr = oldflp->daddr,
926 .saddr = oldflp->saddr,
927 .flowidn_scope = RT_SCOPE_UNIVERSE,
928 .flowidn_mark = oldflp->flowidn_mark,
929 .flowidn_iif = init_net.loopback_dev->ifindex,
930 .flowidn_oif = oldflp->flowidn_oif,
931 };
932 struct dn_route *rt = NULL;
933 struct net_device *dev_out = NULL, *dev;
934 struct neighbour *neigh = NULL;
935 unsigned hash;
936 unsigned flags = 0;
937 struct dn_fib_res res = { .fi = NULL, .type = RTN_UNICAST };
938 int err;
939 int free_res = 0;
940 __le16 gateway = 0;
941
942 if (decnet_debug_level & 16)
943 printk(KERN_DEBUG
944 "dn_route_output_slow: dst=%04x src=%04x mark=%d"
945 " iif=%d oif=%d\n", le16_to_cpu(oldflp->daddr),
946 le16_to_cpu(oldflp->saddr),
947 oldflp->flowidn_mark, init_net.loopback_dev->ifindex,
948 oldflp->flowidn_oif);
949
950 /* If we have an output interface, verify its a DECnet device */
951 if (oldflp->flowidn_oif) {
952 dev_out = dev_get_by_index(&init_net, oldflp->flowidn_oif);
953 err = -ENODEV;
954 if (dev_out && dev_out->dn_ptr == NULL) {
955 dev_put(dev_out);
956 dev_out = NULL;
957 }
958 if (dev_out == NULL)
959 goto out;
960 }
961
962 /* If we have a source address, verify that its a local address */
963 if (oldflp->saddr) {
964 err = -EADDRNOTAVAIL;
965
966 if (dev_out) {
967 if (dn_dev_islocal(dev_out, oldflp->saddr))
968 goto source_ok;
969 dev_put(dev_out);
970 goto out;
971 }
972 rcu_read_lock();
973 for_each_netdev_rcu(&init_net, dev) {
974 if (!dev->dn_ptr)
975 continue;
976 if (!dn_dev_islocal(dev, oldflp->saddr))
977 continue;
978 if ((dev->flags & IFF_LOOPBACK) &&
979 oldflp->daddr &&
980 !dn_dev_islocal(dev, oldflp->daddr))
981 continue;
982
983 dev_out = dev;
984 break;
985 }
986 rcu_read_unlock();
987 if (dev_out == NULL)
988 goto out;
989 dev_hold(dev_out);
990source_ok:
991 ;
992 }
993
994 /* No destination? Assume its local */
995 if (!fld.daddr) {
996 fld.daddr = fld.saddr;
997
998 err = -EADDRNOTAVAIL;
999 if (dev_out)
1000 dev_put(dev_out);
1001 dev_out = init_net.loopback_dev;
1002 dev_hold(dev_out);
1003 if (!fld.daddr) {
1004 fld.daddr =
1005 fld.saddr = dnet_select_source(dev_out, 0,
1006 RT_SCOPE_HOST);
1007 if (!fld.daddr)
1008 goto out;
1009 }
1010 fld.flowidn_oif = init_net.loopback_dev->ifindex;
1011 res.type = RTN_LOCAL;
1012 goto make_route;
1013 }
1014
1015 if (decnet_debug_level & 16)
1016 printk(KERN_DEBUG
1017 "dn_route_output_slow: initial checks complete."
1018 " dst=%o4x src=%04x oif=%d try_hard=%d\n",
1019 le16_to_cpu(fld.daddr), le16_to_cpu(fld.saddr),
1020 fld.flowidn_oif, try_hard);
1021
1022 /*
1023 * N.B. If the kernel is compiled without router support then
1024 * dn_fib_lookup() will evaluate to non-zero so this if () block
1025 * will always be executed.
1026 */
1027 err = -ESRCH;
1028 if (try_hard || (err = dn_fib_lookup(&fld, &res)) != 0) {
1029 struct dn_dev *dn_db;
1030 if (err != -ESRCH)
1031 goto out;
1032 /*
1033 * Here the fallback is basically the standard algorithm for
1034 * routing in endnodes which is described in the DECnet routing
1035 * docs
1036 *
1037 * If we are not trying hard, look in neighbour cache.
1038 * The result is tested to ensure that if a specific output
1039 * device/source address was requested, then we honour that
1040 * here
1041 */
1042 if (!try_hard) {
1043 neigh = neigh_lookup_nodev(&dn_neigh_table, &init_net, &fld.daddr);
1044 if (neigh) {
1045 if ((oldflp->flowidn_oif &&
1046 (neigh->dev->ifindex != oldflp->flowidn_oif)) ||
1047 (oldflp->saddr &&
1048 (!dn_dev_islocal(neigh->dev,
1049 oldflp->saddr)))) {
1050 neigh_release(neigh);
1051 neigh = NULL;
1052 } else {
1053 if (dev_out)
1054 dev_put(dev_out);
1055 if (dn_dev_islocal(neigh->dev, fld.daddr)) {
1056 dev_out = init_net.loopback_dev;
1057 res.type = RTN_LOCAL;
1058 } else {
1059 dev_out = neigh->dev;
1060 }
1061 dev_hold(dev_out);
1062 goto select_source;
1063 }
1064 }
1065 }
1066
1067 /* Not there? Perhaps its a local address */
1068 if (dev_out == NULL)
1069 dev_out = dn_dev_get_default();
1070 err = -ENODEV;
1071 if (dev_out == NULL)
1072 goto out;
1073 dn_db = rcu_dereference_raw(dev_out->dn_ptr);
1074 /* Possible improvement - check all devices for local addr */
1075 if (dn_dev_islocal(dev_out, fld.daddr)) {
1076 dev_put(dev_out);
1077 dev_out = init_net.loopback_dev;
1078 dev_hold(dev_out);
1079 res.type = RTN_LOCAL;
1080 goto select_source;
1081 }
1082 /* Not local either.... try sending it to the default router */
1083 neigh = neigh_clone(dn_db->router);
1084 BUG_ON(neigh && neigh->dev != dev_out);
1085
1086 /* Ok then, we assume its directly connected and move on */
1087select_source:
1088 if (neigh)
1089 gateway = ((struct dn_neigh *)neigh)->addr;
1090 if (gateway == 0)
1091 gateway = fld.daddr;
1092 if (fld.saddr == 0) {
1093 fld.saddr = dnet_select_source(dev_out, gateway,
1094 res.type == RTN_LOCAL ?
1095 RT_SCOPE_HOST :
1096 RT_SCOPE_LINK);
1097 if (fld.saddr == 0 && res.type != RTN_LOCAL)
1098 goto e_addr;
1099 }
1100 fld.flowidn_oif = dev_out->ifindex;
1101 goto make_route;
1102 }
1103 free_res = 1;
1104
1105 if (res.type == RTN_NAT)
1106 goto e_inval;
1107
1108 if (res.type == RTN_LOCAL) {
1109 if (!fld.saddr)
1110 fld.saddr = fld.daddr;
1111 if (dev_out)
1112 dev_put(dev_out);
1113 dev_out = init_net.loopback_dev;
1114 dev_hold(dev_out);
1115 fld.flowidn_oif = dev_out->ifindex;
1116 if (res.fi)
1117 dn_fib_info_put(res.fi);
1118 res.fi = NULL;
1119 goto make_route;
1120 }
1121
1122 if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1123 dn_fib_select_multipath(&fld, &res);
1124
1125 /*
1126 * We could add some logic to deal with default routes here and
1127 * get rid of some of the special casing above.
1128 */
1129
1130 if (!fld.saddr)
1131 fld.saddr = DN_FIB_RES_PREFSRC(res);
1132
1133 if (dev_out)
1134 dev_put(dev_out);
1135 dev_out = DN_FIB_RES_DEV(res);
1136 dev_hold(dev_out);
1137 fld.flowidn_oif = dev_out->ifindex;
1138 gateway = DN_FIB_RES_GW(res);
1139
1140make_route:
1141 if (dev_out->flags & IFF_LOOPBACK)
1142 flags |= RTCF_LOCAL;
1143
1144 rt = dst_alloc(&dn_dst_ops, dev_out, 1, 0, DST_HOST);
1145 if (rt == NULL)
1146 goto e_nobufs;
1147
1148 memset(&rt->fld, 0, sizeof(rt->fld));
1149 rt->fld.saddr = oldflp->saddr;
1150 rt->fld.daddr = oldflp->daddr;
1151 rt->fld.flowidn_oif = oldflp->flowidn_oif;
1152 rt->fld.flowidn_iif = 0;
1153 rt->fld.flowidn_mark = oldflp->flowidn_mark;
1154
1155 rt->rt_saddr = fld.saddr;
1156 rt->rt_daddr = fld.daddr;
1157 rt->rt_gateway = gateway ? gateway : fld.daddr;
1158 rt->rt_local_src = fld.saddr;
1159
1160 rt->rt_dst_map = fld.daddr;
1161 rt->rt_src_map = fld.saddr;
1162
1163 dst_set_neighbour(&rt->dst, neigh);
1164 neigh = NULL;
1165
1166 rt->dst.lastuse = jiffies;
1167 rt->dst.output = dn_output;
1168 rt->dst.input = dn_rt_bug;
1169 rt->rt_flags = flags;
1170 if (flags & RTCF_LOCAL)
1171 rt->dst.input = dn_nsp_rx;
1172
1173 err = dn_rt_set_next_hop(rt, &res);
1174 if (err)
1175 goto e_neighbour;
1176
1177 hash = dn_hash(rt->fld.saddr, rt->fld.daddr);
1178 dn_insert_route(rt, hash, (struct dn_route **)pprt);
1179
1180done:
1181 if (neigh)
1182 neigh_release(neigh);
1183 if (free_res)
1184 dn_fib_res_put(&res);
1185 if (dev_out)
1186 dev_put(dev_out);
1187out:
1188 return err;
1189
1190e_addr:
1191 err = -EADDRNOTAVAIL;
1192 goto done;
1193e_inval:
1194 err = -EINVAL;
1195 goto done;
1196e_nobufs:
1197 err = -ENOBUFS;
1198 goto done;
1199e_neighbour:
1200 dst_free(&rt->dst);
1201 goto e_nobufs;
1202}
1203
1204
1205/*
1206 * N.B. The flags may be moved into the flowi at some future stage.
1207 */
1208static int __dn_route_output_key(struct dst_entry **pprt, const struct flowidn *flp, int flags)
1209{
1210 unsigned hash = dn_hash(flp->saddr, flp->daddr);
1211 struct dn_route *rt = NULL;
1212
1213 if (!(flags & MSG_TRYHARD)) {
1214 rcu_read_lock_bh();
1215 for (rt = rcu_dereference_bh(dn_rt_hash_table[hash].chain); rt;
1216 rt = rcu_dereference_bh(rt->dst.dn_next)) {
1217 if ((flp->daddr == rt->fld.daddr) &&
1218 (flp->saddr == rt->fld.saddr) &&
1219 (flp->flowidn_mark == rt->fld.flowidn_mark) &&
1220 dn_is_output_route(rt) &&
1221 (rt->fld.flowidn_oif == flp->flowidn_oif)) {
1222 dst_use(&rt->dst, jiffies);
1223 rcu_read_unlock_bh();
1224 *pprt = &rt->dst;
1225 return 0;
1226 }
1227 }
1228 rcu_read_unlock_bh();
1229 }
1230
1231 return dn_route_output_slow(pprt, flp, flags);
1232}
1233
1234static int dn_route_output_key(struct dst_entry **pprt, struct flowidn *flp, int flags)
1235{
1236 int err;
1237
1238 err = __dn_route_output_key(pprt, flp, flags);
1239 if (err == 0 && flp->flowidn_proto) {
1240 *pprt = xfrm_lookup(&init_net, *pprt,
1241 flowidn_to_flowi(flp), NULL, 0);
1242 if (IS_ERR(*pprt)) {
1243 err = PTR_ERR(*pprt);
1244 *pprt = NULL;
1245 }
1246 }
1247 return err;
1248}
1249
1250int dn_route_output_sock(struct dst_entry **pprt, struct flowidn *fl, struct sock *sk, int flags)
1251{
1252 int err;
1253
1254 err = __dn_route_output_key(pprt, fl, flags & MSG_TRYHARD);
1255 if (err == 0 && fl->flowidn_proto) {
1256 if (!(flags & MSG_DONTWAIT))
1257 fl->flowidn_flags |= FLOWI_FLAG_CAN_SLEEP;
1258 *pprt = xfrm_lookup(&init_net, *pprt,
1259 flowidn_to_flowi(fl), sk, 0);
1260 if (IS_ERR(*pprt)) {
1261 err = PTR_ERR(*pprt);
1262 *pprt = NULL;
1263 }
1264 }
1265 return err;
1266}
1267
1268static int dn_route_input_slow(struct sk_buff *skb)
1269{
1270 struct dn_route *rt = NULL;
1271 struct dn_skb_cb *cb = DN_SKB_CB(skb);
1272 struct net_device *in_dev = skb->dev;
1273 struct net_device *out_dev = NULL;
1274 struct dn_dev *dn_db;
1275 struct neighbour *neigh = NULL;
1276 unsigned hash;
1277 int flags = 0;
1278 __le16 gateway = 0;
1279 __le16 local_src = 0;
1280 struct flowidn fld = {
1281 .daddr = cb->dst,
1282 .saddr = cb->src,
1283 .flowidn_scope = RT_SCOPE_UNIVERSE,
1284 .flowidn_mark = skb->mark,
1285 .flowidn_iif = skb->dev->ifindex,
1286 };
1287 struct dn_fib_res res = { .fi = NULL, .type = RTN_UNREACHABLE };
1288 int err = -EINVAL;
1289 int free_res = 0;
1290
1291 dev_hold(in_dev);
1292
1293 if ((dn_db = rcu_dereference(in_dev->dn_ptr)) == NULL)
1294 goto out;
1295
1296 /* Zero source addresses are not allowed */
1297 if (fld.saddr == 0)
1298 goto out;
1299
1300 /*
1301 * In this case we've just received a packet from a source
1302 * outside ourselves pretending to come from us. We don't
1303 * allow it any further to prevent routing loops, spoofing and
1304 * other nasties. Loopback packets already have the dst attached
1305 * so this only affects packets which have originated elsewhere.
1306 */
1307 err = -ENOTUNIQ;
1308 if (dn_dev_islocal(in_dev, cb->src))
1309 goto out;
1310
1311 err = dn_fib_lookup(&fld, &res);
1312 if (err) {
1313 if (err != -ESRCH)
1314 goto out;
1315 /*
1316 * Is the destination us ?
1317 */
1318 if (!dn_dev_islocal(in_dev, cb->dst))
1319 goto e_inval;
1320
1321 res.type = RTN_LOCAL;
1322 } else {
1323 __le16 src_map = fld.saddr;
1324 free_res = 1;
1325
1326 out_dev = DN_FIB_RES_DEV(res);
1327 if (out_dev == NULL) {
1328 if (net_ratelimit())
1329 printk(KERN_CRIT "Bug in dn_route_input_slow() "
1330 "No output device\n");
1331 goto e_inval;
1332 }
1333 dev_hold(out_dev);
1334
1335 if (res.r)
1336 src_map = fld.saddr; /* no NAT support for now */
1337
1338 gateway = DN_FIB_RES_GW(res);
1339 if (res.type == RTN_NAT) {
1340 fld.daddr = dn_fib_rules_map_destination(fld.daddr, &res);
1341 dn_fib_res_put(&res);
1342 free_res = 0;
1343 if (dn_fib_lookup(&fld, &res))
1344 goto e_inval;
1345 free_res = 1;
1346 if (res.type != RTN_UNICAST)
1347 goto e_inval;
1348 flags |= RTCF_DNAT;
1349 gateway = fld.daddr;
1350 }
1351 fld.saddr = src_map;
1352 }
1353
1354 switch(res.type) {
1355 case RTN_UNICAST:
1356 /*
1357 * Forwarding check here, we only check for forwarding
1358 * being turned off, if you want to only forward intra
1359 * area, its up to you to set the routing tables up
1360 * correctly.
1361 */
1362 if (dn_db->parms.forwarding == 0)
1363 goto e_inval;
1364
1365 if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1366 dn_fib_select_multipath(&fld, &res);
1367
1368 /*
1369 * Check for out_dev == in_dev. We use the RTCF_DOREDIRECT
1370 * flag as a hint to set the intra-ethernet bit when
1371 * forwarding. If we've got NAT in operation, we don't do
1372 * this optimisation.
1373 */
1374 if (out_dev == in_dev && !(flags & RTCF_NAT))
1375 flags |= RTCF_DOREDIRECT;
1376
1377 local_src = DN_FIB_RES_PREFSRC(res);
1378
1379 case RTN_BLACKHOLE:
1380 case RTN_UNREACHABLE:
1381 break;
1382 case RTN_LOCAL:
1383 flags |= RTCF_LOCAL;
1384 fld.saddr = cb->dst;
1385 fld.daddr = cb->src;
1386
1387 /* Routing tables gave us a gateway */
1388 if (gateway)
1389 goto make_route;
1390
1391 /* Packet was intra-ethernet, so we know its on-link */
1392 if (cb->rt_flags & DN_RT_F_IE) {
1393 gateway = cb->src;
1394 flags |= RTCF_DIRECTSRC;
1395 goto make_route;
1396 }
1397
1398 /* Use the default router if there is one */
1399 neigh = neigh_clone(dn_db->router);
1400 if (neigh) {
1401 gateway = ((struct dn_neigh *)neigh)->addr;
1402 goto make_route;
1403 }
1404
1405 /* Close eyes and pray */
1406 gateway = cb->src;
1407 flags |= RTCF_DIRECTSRC;
1408 goto make_route;
1409 default:
1410 goto e_inval;
1411 }
1412
1413make_route:
1414 rt = dst_alloc(&dn_dst_ops, out_dev, 0, 0, DST_HOST);
1415 if (rt == NULL)
1416 goto e_nobufs;
1417
1418 memset(&rt->fld, 0, sizeof(rt->fld));
1419 rt->rt_saddr = fld.saddr;
1420 rt->rt_daddr = fld.daddr;
1421 rt->rt_gateway = fld.daddr;
1422 if (gateway)
1423 rt->rt_gateway = gateway;
1424 rt->rt_local_src = local_src ? local_src : rt->rt_saddr;
1425
1426 rt->rt_dst_map = fld.daddr;
1427 rt->rt_src_map = fld.saddr;
1428
1429 rt->fld.saddr = cb->src;
1430 rt->fld.daddr = cb->dst;
1431 rt->fld.flowidn_oif = 0;
1432 rt->fld.flowidn_iif = in_dev->ifindex;
1433 rt->fld.flowidn_mark = fld.flowidn_mark;
1434
1435 dst_set_neighbour(&rt->dst, neigh);
1436 rt->dst.lastuse = jiffies;
1437 rt->dst.output = dn_rt_bug;
1438 switch (res.type) {
1439 case RTN_UNICAST:
1440 rt->dst.input = dn_forward;
1441 break;
1442 case RTN_LOCAL:
1443 rt->dst.output = dn_output;
1444 rt->dst.input = dn_nsp_rx;
1445 rt->dst.dev = in_dev;
1446 flags |= RTCF_LOCAL;
1447 break;
1448 default:
1449 case RTN_UNREACHABLE:
1450 case RTN_BLACKHOLE:
1451 rt->dst.input = dst_discard;
1452 }
1453 rt->rt_flags = flags;
1454
1455 err = dn_rt_set_next_hop(rt, &res);
1456 if (err)
1457 goto e_neighbour;
1458
1459 hash = dn_hash(rt->fld.saddr, rt->fld.daddr);
1460 dn_insert_route(rt, hash, &rt);
1461 skb_dst_set(skb, &rt->dst);
1462
1463done:
1464 if (neigh)
1465 neigh_release(neigh);
1466 if (free_res)
1467 dn_fib_res_put(&res);
1468 dev_put(in_dev);
1469 if (out_dev)
1470 dev_put(out_dev);
1471out:
1472 return err;
1473
1474e_inval:
1475 err = -EINVAL;
1476 goto done;
1477
1478e_nobufs:
1479 err = -ENOBUFS;
1480 goto done;
1481
1482e_neighbour:
1483 dst_free(&rt->dst);
1484 goto done;
1485}
1486
1487static int dn_route_input(struct sk_buff *skb)
1488{
1489 struct dn_route *rt;
1490 struct dn_skb_cb *cb = DN_SKB_CB(skb);
1491 unsigned hash = dn_hash(cb->src, cb->dst);
1492
1493 if (skb_dst(skb))
1494 return 0;
1495
1496 rcu_read_lock();
1497 for(rt = rcu_dereference(dn_rt_hash_table[hash].chain); rt != NULL;
1498 rt = rcu_dereference(rt->dst.dn_next)) {
1499 if ((rt->fld.saddr == cb->src) &&
1500 (rt->fld.daddr == cb->dst) &&
1501 (rt->fld.flowidn_oif == 0) &&
1502 (rt->fld.flowidn_mark == skb->mark) &&
1503 (rt->fld.flowidn_iif == cb->iif)) {
1504 dst_use(&rt->dst, jiffies);
1505 rcu_read_unlock();
1506 skb_dst_set(skb, (struct dst_entry *)rt);
1507 return 0;
1508 }
1509 }
1510 rcu_read_unlock();
1511
1512 return dn_route_input_slow(skb);
1513}
1514
1515static int dn_rt_fill_info(struct sk_buff *skb, u32 pid, u32 seq,
1516 int event, int nowait, unsigned int flags)
1517{
1518 struct dn_route *rt = (struct dn_route *)skb_dst(skb);
1519 struct rtmsg *r;
1520 struct nlmsghdr *nlh;
1521 unsigned char *b = skb_tail_pointer(skb);
1522 long expires;
1523
1524 nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*r), flags);
1525 r = NLMSG_DATA(nlh);
1526 r->rtm_family = AF_DECnet;
1527 r->rtm_dst_len = 16;
1528 r->rtm_src_len = 0;
1529 r->rtm_tos = 0;
1530 r->rtm_table = RT_TABLE_MAIN;
1531 RTA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
1532 r->rtm_type = rt->rt_type;
1533 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
1534 r->rtm_scope = RT_SCOPE_UNIVERSE;
1535 r->rtm_protocol = RTPROT_UNSPEC;
1536 if (rt->rt_flags & RTCF_NOTIFY)
1537 r->rtm_flags |= RTM_F_NOTIFY;
1538 RTA_PUT(skb, RTA_DST, 2, &rt->rt_daddr);
1539 if (rt->fld.saddr) {
1540 r->rtm_src_len = 16;
1541 RTA_PUT(skb, RTA_SRC, 2, &rt->fld.saddr);
1542 }
1543 if (rt->dst.dev)
1544 RTA_PUT(skb, RTA_OIF, sizeof(int), &rt->dst.dev->ifindex);
1545 /*
1546 * Note to self - change this if input routes reverse direction when
1547 * they deal only with inputs and not with replies like they do
1548 * currently.
1549 */
1550 RTA_PUT(skb, RTA_PREFSRC, 2, &rt->rt_local_src);
1551 if (rt->rt_daddr != rt->rt_gateway)
1552 RTA_PUT(skb, RTA_GATEWAY, 2, &rt->rt_gateway);
1553 if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
1554 goto rtattr_failure;
1555 expires = rt->dst.expires ? rt->dst.expires - jiffies : 0;
1556 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, 0, 0, expires,
1557 rt->dst.error) < 0)
1558 goto rtattr_failure;
1559 if (dn_is_input_route(rt))
1560 RTA_PUT(skb, RTA_IIF, sizeof(int), &rt->fld.flowidn_iif);
1561
1562 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1563 return skb->len;
1564
1565nlmsg_failure:
1566rtattr_failure:
1567 nlmsg_trim(skb, b);
1568 return -1;
1569}
1570
1571/*
1572 * This is called by both endnodes and routers now.
1573 */
1574static int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, void *arg)
1575{
1576 struct net *net = sock_net(in_skb->sk);
1577 struct rtattr **rta = arg;
1578 struct rtmsg *rtm = NLMSG_DATA(nlh);
1579 struct dn_route *rt = NULL;
1580 struct dn_skb_cb *cb;
1581 int err;
1582 struct sk_buff *skb;
1583 struct flowidn fld;
1584
1585 if (!net_eq(net, &init_net))
1586 return -EINVAL;
1587
1588 memset(&fld, 0, sizeof(fld));
1589 fld.flowidn_proto = DNPROTO_NSP;
1590
1591 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1592 if (skb == NULL)
1593 return -ENOBUFS;
1594 skb_reset_mac_header(skb);
1595 cb = DN_SKB_CB(skb);
1596
1597 if (rta[RTA_SRC-1])
1598 memcpy(&fld.saddr, RTA_DATA(rta[RTA_SRC-1]), 2);
1599 if (rta[RTA_DST-1])
1600 memcpy(&fld.daddr, RTA_DATA(rta[RTA_DST-1]), 2);
1601 if (rta[RTA_IIF-1])
1602 memcpy(&fld.flowidn_iif, RTA_DATA(rta[RTA_IIF-1]), sizeof(int));
1603
1604 if (fld.flowidn_iif) {
1605 struct net_device *dev;
1606 if ((dev = dev_get_by_index(&init_net, fld.flowidn_iif)) == NULL) {
1607 kfree_skb(skb);
1608 return -ENODEV;
1609 }
1610 if (!dev->dn_ptr) {
1611 dev_put(dev);
1612 kfree_skb(skb);
1613 return -ENODEV;
1614 }
1615 skb->protocol = htons(ETH_P_DNA_RT);
1616 skb->dev = dev;
1617 cb->src = fld.saddr;
1618 cb->dst = fld.daddr;
1619 local_bh_disable();
1620 err = dn_route_input(skb);
1621 local_bh_enable();
1622 memset(cb, 0, sizeof(struct dn_skb_cb));
1623 rt = (struct dn_route *)skb_dst(skb);
1624 if (!err && -rt->dst.error)
1625 err = rt->dst.error;
1626 } else {
1627 int oif = 0;
1628 if (rta[RTA_OIF - 1])
1629 memcpy(&oif, RTA_DATA(rta[RTA_OIF - 1]), sizeof(int));
1630 fld.flowidn_oif = oif;
1631 err = dn_route_output_key((struct dst_entry **)&rt, &fld, 0);
1632 }
1633
1634 if (skb->dev)
1635 dev_put(skb->dev);
1636 skb->dev = NULL;
1637 if (err)
1638 goto out_free;
1639 skb_dst_set(skb, &rt->dst);
1640 if (rtm->rtm_flags & RTM_F_NOTIFY)
1641 rt->rt_flags |= RTCF_NOTIFY;
1642
1643 err = dn_rt_fill_info(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, RTM_NEWROUTE, 0, 0);
1644
1645 if (err == 0)
1646 goto out_free;
1647 if (err < 0) {
1648 err = -EMSGSIZE;
1649 goto out_free;
1650 }
1651
1652 return rtnl_unicast(skb, &init_net, NETLINK_CB(in_skb).pid);
1653
1654out_free:
1655 kfree_skb(skb);
1656 return err;
1657}
1658
1659/*
1660 * For routers, this is called from dn_fib_dump, but for endnodes its
1661 * called directly from the rtnetlink dispatch table.
1662 */
1663int dn_cache_dump(struct sk_buff *skb, struct netlink_callback *cb)
1664{
1665 struct net *net = sock_net(skb->sk);
1666 struct dn_route *rt;
1667 int h, s_h;
1668 int idx, s_idx;
1669
1670 if (!net_eq(net, &init_net))
1671 return 0;
1672
1673 if (NLMSG_PAYLOAD(cb->nlh, 0) < sizeof(struct rtmsg))
1674 return -EINVAL;
1675 if (!(((struct rtmsg *)NLMSG_DATA(cb->nlh))->rtm_flags&RTM_F_CLONED))
1676 return 0;
1677
1678 s_h = cb->args[0];
1679 s_idx = idx = cb->args[1];
1680 for(h = 0; h <= dn_rt_hash_mask; h++) {
1681 if (h < s_h)
1682 continue;
1683 if (h > s_h)
1684 s_idx = 0;
1685 rcu_read_lock_bh();
1686 for(rt = rcu_dereference_bh(dn_rt_hash_table[h].chain), idx = 0;
1687 rt;
1688 rt = rcu_dereference_bh(rt->dst.dn_next), idx++) {
1689 if (idx < s_idx)
1690 continue;
1691 skb_dst_set(skb, dst_clone(&rt->dst));
1692 if (dn_rt_fill_info(skb, NETLINK_CB(cb->skb).pid,
1693 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
1694 1, NLM_F_MULTI) <= 0) {
1695 skb_dst_drop(skb);
1696 rcu_read_unlock_bh();
1697 goto done;
1698 }
1699 skb_dst_drop(skb);
1700 }
1701 rcu_read_unlock_bh();
1702 }
1703
1704done:
1705 cb->args[0] = h;
1706 cb->args[1] = idx;
1707 return skb->len;
1708}
1709
1710#ifdef CONFIG_PROC_FS
1711struct dn_rt_cache_iter_state {
1712 int bucket;
1713};
1714
1715static struct dn_route *dn_rt_cache_get_first(struct seq_file *seq)
1716{
1717 struct dn_route *rt = NULL;
1718 struct dn_rt_cache_iter_state *s = seq->private;
1719
1720 for(s->bucket = dn_rt_hash_mask; s->bucket >= 0; --s->bucket) {
1721 rcu_read_lock_bh();
1722 rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1723 if (rt)
1724 break;
1725 rcu_read_unlock_bh();
1726 }
1727 return rt;
1728}
1729
1730static struct dn_route *dn_rt_cache_get_next(struct seq_file *seq, struct dn_route *rt)
1731{
1732 struct dn_rt_cache_iter_state *s = seq->private;
1733
1734 rt = rcu_dereference_bh(rt->dst.dn_next);
1735 while (!rt) {
1736 rcu_read_unlock_bh();
1737 if (--s->bucket < 0)
1738 break;
1739 rcu_read_lock_bh();
1740 rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1741 }
1742 return rt;
1743}
1744
1745static void *dn_rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
1746{
1747 struct dn_route *rt = dn_rt_cache_get_first(seq);
1748
1749 if (rt) {
1750 while(*pos && (rt = dn_rt_cache_get_next(seq, rt)))
1751 --*pos;
1752 }
1753 return *pos ? NULL : rt;
1754}
1755
1756static void *dn_rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1757{
1758 struct dn_route *rt = dn_rt_cache_get_next(seq, v);
1759 ++*pos;
1760 return rt;
1761}
1762
1763static void dn_rt_cache_seq_stop(struct seq_file *seq, void *v)
1764{
1765 if (v)
1766 rcu_read_unlock_bh();
1767}
1768
1769static int dn_rt_cache_seq_show(struct seq_file *seq, void *v)
1770{
1771 struct dn_route *rt = v;
1772 char buf1[DN_ASCBUF_LEN], buf2[DN_ASCBUF_LEN];
1773
1774 seq_printf(seq, "%-8s %-7s %-7s %04d %04d %04d\n",
1775 rt->dst.dev ? rt->dst.dev->name : "*",
1776 dn_addr2asc(le16_to_cpu(rt->rt_daddr), buf1),
1777 dn_addr2asc(le16_to_cpu(rt->rt_saddr), buf2),
1778 atomic_read(&rt->dst.__refcnt),
1779 rt->dst.__use,
1780 (int) dst_metric(&rt->dst, RTAX_RTT));
1781 return 0;
1782}
1783
1784static const struct seq_operations dn_rt_cache_seq_ops = {
1785 .start = dn_rt_cache_seq_start,
1786 .next = dn_rt_cache_seq_next,
1787 .stop = dn_rt_cache_seq_stop,
1788 .show = dn_rt_cache_seq_show,
1789};
1790
1791static int dn_rt_cache_seq_open(struct inode *inode, struct file *file)
1792{
1793 return seq_open_private(file, &dn_rt_cache_seq_ops,
1794 sizeof(struct dn_rt_cache_iter_state));
1795}
1796
1797static const struct file_operations dn_rt_cache_seq_fops = {
1798 .owner = THIS_MODULE,
1799 .open = dn_rt_cache_seq_open,
1800 .read = seq_read,
1801 .llseek = seq_lseek,
1802 .release = seq_release_private,
1803};
1804
1805#endif /* CONFIG_PROC_FS */
1806
1807void __init dn_route_init(void)
1808{
1809 int i, goal, order;
1810
1811 dn_dst_ops.kmem_cachep =
1812 kmem_cache_create("dn_dst_cache", sizeof(struct dn_route), 0,
1813 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
1814 dst_entries_init(&dn_dst_ops);
1815 setup_timer(&dn_route_timer, dn_dst_check_expire, 0);
1816 dn_route_timer.expires = jiffies + decnet_dst_gc_interval * HZ;
1817 add_timer(&dn_route_timer);
1818
1819 goal = totalram_pages >> (26 - PAGE_SHIFT);
1820
1821 for(order = 0; (1UL << order) < goal; order++)
1822 /* NOTHING */;
1823
1824 /*
1825 * Only want 1024 entries max, since the table is very, very unlikely
1826 * to be larger than that.
1827 */
1828 while(order && ((((1UL << order) * PAGE_SIZE) /
1829 sizeof(struct dn_rt_hash_bucket)) >= 2048))
1830 order--;
1831
1832 do {
1833 dn_rt_hash_mask = (1UL << order) * PAGE_SIZE /
1834 sizeof(struct dn_rt_hash_bucket);
1835 while(dn_rt_hash_mask & (dn_rt_hash_mask - 1))
1836 dn_rt_hash_mask--;
1837 dn_rt_hash_table = (struct dn_rt_hash_bucket *)
1838 __get_free_pages(GFP_ATOMIC, order);
1839 } while (dn_rt_hash_table == NULL && --order > 0);
1840
1841 if (!dn_rt_hash_table)
1842 panic("Failed to allocate DECnet route cache hash table\n");
1843
1844 printk(KERN_INFO
1845 "DECnet: Routing cache hash table of %u buckets, %ldKbytes\n",
1846 dn_rt_hash_mask,
1847 (long)(dn_rt_hash_mask*sizeof(struct dn_rt_hash_bucket))/1024);
1848
1849 dn_rt_hash_mask--;
1850 for(i = 0; i <= dn_rt_hash_mask; i++) {
1851 spin_lock_init(&dn_rt_hash_table[i].lock);
1852 dn_rt_hash_table[i].chain = NULL;
1853 }
1854
1855 dn_dst_ops.gc_thresh = (dn_rt_hash_mask + 1);
1856
1857 proc_net_fops_create(&init_net, "decnet_cache", S_IRUGO, &dn_rt_cache_seq_fops);
1858
1859#ifdef CONFIG_DECNET_ROUTER
1860 rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute,
1861 dn_fib_dump, NULL);
1862#else
1863 rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute,
1864 dn_cache_dump, NULL);
1865#endif
1866}
1867
1868void __exit dn_route_cleanup(void)
1869{
1870 del_timer(&dn_route_timer);
1871 dn_run_flush(0);
1872
1873 proc_net_remove(&init_net, "decnet_cache");
1874 dst_entries_destroy(&dn_dst_ops);
1875}
1876