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mm: fix return value of scan_lru_pages in memory unplug
[linux-2.6/btrfs-unstable.git] / net / decnet / dn_route.c
blobdf0f3e54ff8aba58dac157ab2b2c866453437310
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
94 struct dn_rt_hash_bucket
95 {
96 struct dn_route *chain;
97 spinlock_t lock;
98 };
99
100 extern struct neigh_table dn_neigh_table;
101
102
103 static unsigned char dn_hiord_addr[6] = {0xAA,0x00,0x04,0x00,0x00,0x00};
104
105 static const int dn_rt_min_delay = 2 * HZ;
106 static const int dn_rt_max_delay = 10 * HZ;
107 static const int dn_rt_mtu_expires = 10 * 60 * HZ;
108
109 static unsigned long dn_rt_deadline;
110
111 static int dn_dst_gc(struct dst_ops *ops);
112 static struct dst_entry *dn_dst_check(struct dst_entry *, __u32);
113 static struct dst_entry *dn_dst_negative_advice(struct dst_entry *);
114 static void dn_dst_link_failure(struct sk_buff *);
115 static void dn_dst_update_pmtu(struct dst_entry *dst, u32 mtu);
116 static int dn_route_input(struct sk_buff *);
117 static void dn_run_flush(unsigned long dummy);
118
119 static struct dn_rt_hash_bucket *dn_rt_hash_table;
120 static unsigned dn_rt_hash_mask;
121
122 static struct timer_list dn_route_timer;
123 static DEFINE_TIMER(dn_rt_flush_timer, dn_run_flush, 0, 0);
124 int decnet_dst_gc_interval = 2;
125
126 static struct dst_ops dn_dst_ops = {
127 .family = PF_DECnet,
128 .protocol = cpu_to_be16(ETH_P_DNA_RT),
129 .gc_thresh = 128,
130 .gc = dn_dst_gc,
131 .check = dn_dst_check,
132 .negative_advice = dn_dst_negative_advice,
133 .link_failure = dn_dst_link_failure,
134 .update_pmtu = dn_dst_update_pmtu,
135 };
136
137 static __inline__ unsigned dn_hash(__le16 src, __le16 dst)
138 {
139 __u16 tmp = (__u16 __force)(src ^ dst);
140 tmp ^= (tmp >> 3);
141 tmp ^= (tmp >> 5);
142 tmp ^= (tmp >> 10);
143 return dn_rt_hash_mask & (unsigned)tmp;
144 }
145
146 static inline void dnrt_free(struct dn_route *rt)
147 {
148 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
149 }
150
151 static inline void dnrt_drop(struct dn_route *rt)
152 {
153 dst_release(&rt->dst);
154 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
155 }
156
157 static void dn_dst_check_expire(unsigned long dummy)
158 {
159 int i;
160 struct dn_route *rt, **rtp;
161 unsigned long now = jiffies;
162 unsigned long expire = 120 * HZ;
163
164 for(i = 0; i <= dn_rt_hash_mask; i++) {
165 rtp = &dn_rt_hash_table[i].chain;
166
167 spin_lock(&dn_rt_hash_table[i].lock);
168 while((rt=*rtp) != NULL) {
169 if (atomic_read(&rt->dst.__refcnt) ||
170 (now - rt->dst.lastuse) < expire) {
171 rtp = &rt->dst.dn_next;
172 continue;
173 }
174 *rtp = rt->dst.dn_next;
175 rt->dst.dn_next = NULL;
176 dnrt_free(rt);
177 }
178 spin_unlock(&dn_rt_hash_table[i].lock);
179
180 if ((jiffies - now) > 0)
181 break;
182 }
183
184 mod_timer(&dn_route_timer, now + decnet_dst_gc_interval * HZ);
185 }
186
187 static int dn_dst_gc(struct dst_ops *ops)
188 {
189 struct dn_route *rt, **rtp;
190 int i;
191 unsigned long now = jiffies;
192 unsigned long expire = 10 * HZ;
193
194 for(i = 0; i <= dn_rt_hash_mask; i++) {
195
196 spin_lock_bh(&dn_rt_hash_table[i].lock);
197 rtp = &dn_rt_hash_table[i].chain;
198
199 while((rt=*rtp) != NULL) {
200 if (atomic_read(&rt->dst.__refcnt) ||
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 dnrt_drop(rt);
208 break;
209 }
210 spin_unlock_bh(&dn_rt_hash_table[i].lock);
211 }
212
213 return 0;
214 }
215
216 /*
217 * The decnet standards don't impose a particular minimum mtu, what they
218 * do insist on is that the routing layer accepts a datagram of at least
219 * 230 bytes long. Here we have to subtract the routing header length from
220 * 230 to get the minimum acceptable mtu. If there is no neighbour, then we
221 * assume the worst and use a long header size.
222 *
223 * We update both the mtu and the advertised mss (i.e. the segment size we
224 * advertise to the other end).
225 */
226 static void dn_dst_update_pmtu(struct dst_entry *dst, u32 mtu)
227 {
228 u32 min_mtu = 230;
229 struct dn_dev *dn = dst->neighbour ?
230 (struct dn_dev *)dst->neighbour->dev->dn_ptr : NULL;
231
232 if (dn && dn->use_long == 0)
233 min_mtu -= 6;
234 else
235 min_mtu -= 21;
236
237 if (dst_metric(dst, RTAX_MTU) > mtu && mtu >= min_mtu) {
238 if (!(dst_metric_locked(dst, RTAX_MTU))) {
239 dst->metrics[RTAX_MTU-1] = mtu;
240 dst_set_expires(dst, dn_rt_mtu_expires);
241 }
242 if (!(dst_metric_locked(dst, RTAX_ADVMSS))) {
243 u32 mss = mtu - DN_MAX_NSP_DATA_HEADER;
244 if (dst_metric(dst, RTAX_ADVMSS) > mss)
245 dst->metrics[RTAX_ADVMSS-1] = mss;
246 }
247 }
248 }
249
250 /*
251 * When a route has been marked obsolete. (e.g. routing cache flush)
252 */
253 static struct dst_entry *dn_dst_check(struct dst_entry *dst, __u32 cookie)
254 {
255 return NULL;
256 }
257
258 static struct dst_entry *dn_dst_negative_advice(struct dst_entry *dst)
259 {
260 dst_release(dst);
261 return NULL;
262 }
263
264 static void dn_dst_link_failure(struct sk_buff *skb)
265 {
266 }
267
268 static inline int compare_keys(struct flowi *fl1, struct flowi *fl2)
269 {
270 return ((fl1->nl_u.dn_u.daddr ^ fl2->nl_u.dn_u.daddr) |
271 (fl1->nl_u.dn_u.saddr ^ fl2->nl_u.dn_u.saddr) |
272 (fl1->mark ^ fl2->mark) |
273 (fl1->nl_u.dn_u.scope ^ fl2->nl_u.dn_u.scope) |
274 (fl1->oif ^ fl2->oif) |
275 (fl1->iif ^ fl2->iif)) == 0;
276 }
277
278 static int dn_insert_route(struct dn_route *rt, unsigned hash, struct dn_route **rp)
279 {
280 struct dn_route *rth, **rthp;
281 unsigned long now = jiffies;
282
283 rthp = &dn_rt_hash_table[hash].chain;
284
285 spin_lock_bh(&dn_rt_hash_table[hash].lock);
286 while((rth = *rthp) != NULL) {
287 if (compare_keys(&rth->fl, &rt->fl)) {
288 /* Put it first */
289 *rthp = rth->dst.dn_next;
290 rcu_assign_pointer(rth->dst.dn_next,
291 dn_rt_hash_table[hash].chain);
292 rcu_assign_pointer(dn_rt_hash_table[hash].chain, rth);
293
294 dst_use(&rth->dst, now);
295 spin_unlock_bh(&dn_rt_hash_table[hash].lock);
296
297 dnrt_drop(rt);
298 *rp = rth;
299 return 0;
300 }
301 rthp = &rth->dst.dn_next;
302 }
303
304 rcu_assign_pointer(rt->dst.dn_next, dn_rt_hash_table[hash].chain);
305 rcu_assign_pointer(dn_rt_hash_table[hash].chain, rt);
306
307 dst_use(&rt->dst, now);
308 spin_unlock_bh(&dn_rt_hash_table[hash].lock);
309 *rp = rt;
310 return 0;
311 }
312
313 static void dn_run_flush(unsigned long dummy)
314 {
315 int i;
316 struct dn_route *rt, *next;
317
318 for(i = 0; i < dn_rt_hash_mask; i++) {
319 spin_lock_bh(&dn_rt_hash_table[i].lock);
320
321 if ((rt = xchg(&dn_rt_hash_table[i].chain, NULL)) == NULL)
322 goto nothing_to_declare;
323
324 for(; rt; rt=next) {
325 next = rt->dst.dn_next;
326 rt->dst.dn_next = NULL;
327 dst_free((struct dst_entry *)rt);
328 }
329
330 nothing_to_declare:
331 spin_unlock_bh(&dn_rt_hash_table[i].lock);
332 }
333 }
334
335 static DEFINE_SPINLOCK(dn_rt_flush_lock);
336
337 void dn_rt_cache_flush(int delay)
338 {
339 unsigned long now = jiffies;
340 int user_mode = !in_interrupt();
341
342 if (delay < 0)
343 delay = dn_rt_min_delay;
344
345 spin_lock_bh(&dn_rt_flush_lock);
346
347 if (del_timer(&dn_rt_flush_timer) && delay > 0 && dn_rt_deadline) {
348 long tmo = (long)(dn_rt_deadline - now);
349
350 if (user_mode && tmo < dn_rt_max_delay - dn_rt_min_delay)
351 tmo = 0;
352
353 if (delay > tmo)
354 delay = tmo;
355 }
356
357 if (delay <= 0) {
358 spin_unlock_bh(&dn_rt_flush_lock);
359 dn_run_flush(0);
360 return;
361 }
362
363 if (dn_rt_deadline == 0)
364 dn_rt_deadline = now + dn_rt_max_delay;
365
366 dn_rt_flush_timer.expires = now + delay;
367 add_timer(&dn_rt_flush_timer);
368 spin_unlock_bh(&dn_rt_flush_lock);
369 }
370
371 /**
372 * dn_return_short - Return a short packet to its sender
373 * @skb: The packet to return
374 *
375 */
376 static int dn_return_short(struct sk_buff *skb)
377 {
378 struct dn_skb_cb *cb;
379 unsigned char *ptr;
380 __le16 *src;
381 __le16 *dst;
382
383 /* Add back headers */
384 skb_push(skb, skb->data - skb_network_header(skb));
385
386 if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
387 return NET_RX_DROP;
388
389 cb = DN_SKB_CB(skb);
390 /* Skip packet length and point to flags */
391 ptr = skb->data + 2;
392 *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
393
394 dst = (__le16 *)ptr;
395 ptr += 2;
396 src = (__le16 *)ptr;
397 ptr += 2;
398 *ptr = 0; /* Zero hop count */
399
400 swap(*src, *dst);
401
402 skb->pkt_type = PACKET_OUTGOING;
403 dn_rt_finish_output(skb, NULL, NULL);
404 return NET_RX_SUCCESS;
405 }
406
407 /**
408 * dn_return_long - Return a long packet to its sender
409 * @skb: The long format packet to return
410 *
411 */
412 static int dn_return_long(struct sk_buff *skb)
413 {
414 struct dn_skb_cb *cb;
415 unsigned char *ptr;
416 unsigned char *src_addr, *dst_addr;
417 unsigned char tmp[ETH_ALEN];
418
419 /* Add back all headers */
420 skb_push(skb, skb->data - skb_network_header(skb));
421
422 if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
423 return NET_RX_DROP;
424
425 cb = DN_SKB_CB(skb);
426 /* Ignore packet length and point to flags */
427 ptr = skb->data + 2;
428
429 /* Skip padding */
430 if (*ptr & DN_RT_F_PF) {
431 char padlen = (*ptr & ~DN_RT_F_PF);
432 ptr += padlen;
433 }
434
435 *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
436 ptr += 2;
437 dst_addr = ptr;
438 ptr += 8;
439 src_addr = ptr;
440 ptr += 6;
441 *ptr = 0; /* Zero hop count */
442
443 /* Swap source and destination */
444 memcpy(tmp, src_addr, ETH_ALEN);
445 memcpy(src_addr, dst_addr, ETH_ALEN);
446 memcpy(dst_addr, tmp, ETH_ALEN);
447
448 skb->pkt_type = PACKET_OUTGOING;
449 dn_rt_finish_output(skb, dst_addr, src_addr);
450 return NET_RX_SUCCESS;
451 }
452
453 /**
454 * dn_route_rx_packet - Try and find a route for an incoming packet
455 * @skb: The packet to find a route for
456 *
457 * Returns: result of input function if route is found, error code otherwise
458 */
459 static int dn_route_rx_packet(struct sk_buff *skb)
460 {
461 struct dn_skb_cb *cb = DN_SKB_CB(skb);
462 int err;
463
464 if ((err = dn_route_input(skb)) == 0)
465 return dst_input(skb);
466
467 if (decnet_debug_level & 4) {
468 char *devname = skb->dev ? skb->dev->name : "???";
469 struct dn_skb_cb *cb = DN_SKB_CB(skb);
470 printk(KERN_DEBUG
471 "DECnet: dn_route_rx_packet: rt_flags=0x%02x dev=%s len=%d src=0x%04hx dst=0x%04hx err=%d type=%d\n",
472 (int)cb->rt_flags, devname, skb->len,
473 le16_to_cpu(cb->src), le16_to_cpu(cb->dst),
474 err, skb->pkt_type);
475 }
476
477 if ((skb->pkt_type == PACKET_HOST) && (cb->rt_flags & DN_RT_F_RQR)) {
478 switch(cb->rt_flags & DN_RT_PKT_MSK) {
479 case DN_RT_PKT_SHORT:
480 return dn_return_short(skb);
481 case DN_RT_PKT_LONG:
482 return dn_return_long(skb);
483 }
484 }
485
486 kfree_skb(skb);
487 return NET_RX_DROP;
488 }
489
490 static int dn_route_rx_long(struct sk_buff *skb)
491 {
492 struct dn_skb_cb *cb = DN_SKB_CB(skb);
493 unsigned char *ptr = skb->data;
494
495 if (!pskb_may_pull(skb, 21)) /* 20 for long header, 1 for shortest nsp */
496 goto drop_it;
497
498 skb_pull(skb, 20);
499 skb_reset_transport_header(skb);
500
501 /* Destination info */
502 ptr += 2;
503 cb->dst = dn_eth2dn(ptr);
504 if (memcmp(ptr, dn_hiord_addr, 4) != 0)
505 goto drop_it;
506 ptr += 6;
507
508
509 /* Source info */
510 ptr += 2;
511 cb->src = dn_eth2dn(ptr);
512 if (memcmp(ptr, dn_hiord_addr, 4) != 0)
513 goto drop_it;
514 ptr += 6;
515 /* Other junk */
516 ptr++;
517 cb->hops = *ptr++; /* Visit Count */
518
519 return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING, skb, skb->dev, NULL,
520 dn_route_rx_packet);
521
522 drop_it:
523 kfree_skb(skb);
524 return NET_RX_DROP;
525 }
526
527
528
529 static int dn_route_rx_short(struct sk_buff *skb)
530 {
531 struct dn_skb_cb *cb = DN_SKB_CB(skb);
532 unsigned char *ptr = skb->data;
533
534 if (!pskb_may_pull(skb, 6)) /* 5 for short header + 1 for shortest nsp */
535 goto drop_it;
536
537 skb_pull(skb, 5);
538 skb_reset_transport_header(skb);
539
540 cb->dst = *(__le16 *)ptr;
541 ptr += 2;
542 cb->src = *(__le16 *)ptr;
543 ptr += 2;
544 cb->hops = *ptr & 0x3f;
545
546 return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING, skb, skb->dev, NULL,
547 dn_route_rx_packet);
548
549 drop_it:
550 kfree_skb(skb);
551 return NET_RX_DROP;
552 }
553
554 static int dn_route_discard(struct sk_buff *skb)
555 {
556 /*
557 * I know we drop the packet here, but thats considered success in
558 * this case
559 */
560 kfree_skb(skb);
561 return NET_RX_SUCCESS;
562 }
563
564 static int dn_route_ptp_hello(struct sk_buff *skb)
565 {
566 dn_dev_hello(skb);
567 dn_neigh_pointopoint_hello(skb);
568 return NET_RX_SUCCESS;
569 }
570
571 int dn_route_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
572 {
573 struct dn_skb_cb *cb;
574 unsigned char flags = 0;
575 __u16 len = le16_to_cpu(*(__le16 *)skb->data);
576 struct dn_dev *dn = (struct dn_dev *)dev->dn_ptr;
577 unsigned char padlen = 0;
578
579 if (!net_eq(dev_net(dev), &init_net))
580 goto dump_it;
581
582 if (dn == NULL)
583 goto dump_it;
584
585 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
586 goto out;
587
588 if (!pskb_may_pull(skb, 3))
589 goto dump_it;
590
591 skb_pull(skb, 2);
592
593 if (len > skb->len)
594 goto dump_it;
595
596 skb_trim(skb, len);
597
598 flags = *skb->data;
599
600 cb = DN_SKB_CB(skb);
601 cb->stamp = jiffies;
602 cb->iif = dev->ifindex;
603
604 /*
605 * If we have padding, remove it.
606 */
607 if (flags & DN_RT_F_PF) {
608 padlen = flags & ~DN_RT_F_PF;
609 if (!pskb_may_pull(skb, padlen + 1))
610 goto dump_it;
611 skb_pull(skb, padlen);
612 flags = *skb->data;
613 }
614
615 skb_reset_network_header(skb);
616
617 /*
618 * Weed out future version DECnet
619 */
620 if (flags & DN_RT_F_VER)
621 goto dump_it;
622
623 cb->rt_flags = flags;
624
625 if (decnet_debug_level & 1)
626 printk(KERN_DEBUG
627 "dn_route_rcv: got 0x%02x from %s [%d %d %d]\n",
628 (int)flags, (dev) ? dev->name : "???", len, skb->len,
629 padlen);
630
631 if (flags & DN_RT_PKT_CNTL) {
632 if (unlikely(skb_linearize(skb)))
633 goto dump_it;
634
635 switch(flags & DN_RT_CNTL_MSK) {
636 case DN_RT_PKT_INIT:
637 dn_dev_init_pkt(skb);
638 break;
639 case DN_RT_PKT_VERI:
640 dn_dev_veri_pkt(skb);
641 break;
642 }
643
644 if (dn->parms.state != DN_DEV_S_RU)
645 goto dump_it;
646
647 switch(flags & DN_RT_CNTL_MSK) {
648 case DN_RT_PKT_HELO:
649 return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
650 skb, skb->dev, NULL,
651 dn_route_ptp_hello);
652
653 case DN_RT_PKT_L1RT:
654 case DN_RT_PKT_L2RT:
655 return NF_HOOK(NFPROTO_DECNET, NF_DN_ROUTE,
656 skb, skb->dev, NULL,
657 dn_route_discard);
658 case DN_RT_PKT_ERTH:
659 return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
660 skb, skb->dev, NULL,
661 dn_neigh_router_hello);
662
663 case DN_RT_PKT_EEDH:
664 return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
665 skb, skb->dev, NULL,
666 dn_neigh_endnode_hello);
667 }
668 } else {
669 if (dn->parms.state != DN_DEV_S_RU)
670 goto dump_it;
671
672 skb_pull(skb, 1); /* Pull flags */
673
674 switch(flags & DN_RT_PKT_MSK) {
675 case DN_RT_PKT_LONG:
676 return dn_route_rx_long(skb);
677 case DN_RT_PKT_SHORT:
678 return dn_route_rx_short(skb);
679 }
680 }
681
682 dump_it:
683 kfree_skb(skb);
684 out:
685 return NET_RX_DROP;
686 }
687
688 static int dn_output(struct sk_buff *skb)
689 {
690 struct dst_entry *dst = skb_dst(skb);
691 struct dn_route *rt = (struct dn_route *)dst;
692 struct net_device *dev = dst->dev;
693 struct dn_skb_cb *cb = DN_SKB_CB(skb);
694 struct neighbour *neigh;
695
696 int err = -EINVAL;
697
698 if ((neigh = dst->neighbour) == NULL)
699 goto error;
700
701 skb->dev = dev;
702
703 cb->src = rt->rt_saddr;
704 cb->dst = rt->rt_daddr;
705
706 /*
707 * Always set the Intra-Ethernet bit on all outgoing packets
708 * originated on this node. Only valid flag from upper layers
709 * is return-to-sender-requested. Set hop count to 0 too.
710 */
711 cb->rt_flags &= ~DN_RT_F_RQR;
712 cb->rt_flags |= DN_RT_F_IE;
713 cb->hops = 0;
714
715 return NF_HOOK(NFPROTO_DECNET, NF_DN_LOCAL_OUT, skb, NULL, dev,
716 neigh->output);
717
718 error:
719 if (net_ratelimit())
720 printk(KERN_DEBUG "dn_output: This should not happen\n");
721
722 kfree_skb(skb);
723
724 return err;
725 }
726
727 static int dn_forward(struct sk_buff *skb)
728 {
729 struct dn_skb_cb *cb = DN_SKB_CB(skb);
730 struct dst_entry *dst = skb_dst(skb);
731 struct dn_dev *dn_db = dst->dev->dn_ptr;
732 struct dn_route *rt;
733 struct neighbour *neigh = dst->neighbour;
734 int header_len;
735 #ifdef CONFIG_NETFILTER
736 struct net_device *dev = skb->dev;
737 #endif
738
739 if (skb->pkt_type != PACKET_HOST)
740 goto drop;
741
742 /* Ensure that we have enough space for headers */
743 rt = (struct dn_route *)skb_dst(skb);
744 header_len = dn_db->use_long ? 21 : 6;
745 if (skb_cow(skb, LL_RESERVED_SPACE(rt->dst.dev)+header_len))
746 goto drop;
747
748 /*
749 * Hop count exceeded.
750 */
751 if (++cb->hops > 30)
752 goto drop;
753
754 skb->dev = rt->dst.dev;
755
756 /*
757 * If packet goes out same interface it came in on, then set
758 * the Intra-Ethernet bit. This has no effect for short
759 * packets, so we don't need to test for them here.
760 */
761 cb->rt_flags &= ~DN_RT_F_IE;
762 if (rt->rt_flags & RTCF_DOREDIRECT)
763 cb->rt_flags |= DN_RT_F_IE;
764
765 return NF_HOOK(NFPROTO_DECNET, NF_DN_FORWARD, skb, dev, skb->dev,
766 neigh->output);
767
768 drop:
769 kfree_skb(skb);
770 return NET_RX_DROP;
771 }
772
773 /*
774 * Used to catch bugs. This should never normally get
775 * called.
776 */
777 static int dn_rt_bug(struct sk_buff *skb)
778 {
779 if (net_ratelimit()) {
780 struct dn_skb_cb *cb = DN_SKB_CB(skb);
781
782 printk(KERN_DEBUG "dn_rt_bug: skb from:%04x to:%04x\n",
783 le16_to_cpu(cb->src), le16_to_cpu(cb->dst));
784 }
785
786 kfree_skb(skb);
787
788 return NET_RX_DROP;
789 }
790
791 static int dn_rt_set_next_hop(struct dn_route *rt, struct dn_fib_res *res)
792 {
793 struct dn_fib_info *fi = res->fi;
794 struct net_device *dev = rt->dst.dev;
795 struct neighbour *n;
796 unsigned mss;
797
798 if (fi) {
799 if (DN_FIB_RES_GW(*res) &&
800 DN_FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
801 rt->rt_gateway = DN_FIB_RES_GW(*res);
802 memcpy(rt->dst.metrics, fi->fib_metrics,
803 sizeof(rt->dst.metrics));
804 }
805 rt->rt_type = res->type;
806
807 if (dev != NULL && rt->dst.neighbour == NULL) {
808 n = __neigh_lookup_errno(&dn_neigh_table, &rt->rt_gateway, dev);
809 if (IS_ERR(n))
810 return PTR_ERR(n);
811 rt->dst.neighbour = n;
812 }
813
814 if (dst_metric(&rt->dst, RTAX_MTU) == 0 ||
815 dst_metric(&rt->dst, RTAX_MTU) > rt->dst.dev->mtu)
816 rt->dst.metrics[RTAX_MTU-1] = rt->dst.dev->mtu;
817 mss = dn_mss_from_pmtu(dev, dst_mtu(&rt->dst));
818 if (dst_metric(&rt->dst, RTAX_ADVMSS) == 0 ||
819 dst_metric(&rt->dst, RTAX_ADVMSS) > mss)
820 rt->dst.metrics[RTAX_ADVMSS-1] = mss;
821 return 0;
822 }
823
824 static inline int dn_match_addr(__le16 addr1, __le16 addr2)
825 {
826 __u16 tmp = le16_to_cpu(addr1) ^ le16_to_cpu(addr2);
827 int match = 16;
828 while(tmp) {
829 tmp >>= 1;
830 match--;
831 }
832 return match;
833 }
834
835 static __le16 dnet_select_source(const struct net_device *dev, __le16 daddr, int scope)
836 {
837 __le16 saddr = 0;
838 struct dn_dev *dn_db = dev->dn_ptr;
839 struct dn_ifaddr *ifa;
840 int best_match = 0;
841 int ret;
842
843 read_lock(&dev_base_lock);
844 for(ifa = dn_db->ifa_list; ifa; ifa = ifa->ifa_next) {
845 if (ifa->ifa_scope > scope)
846 continue;
847 if (!daddr) {
848 saddr = ifa->ifa_local;
849 break;
850 }
851 ret = dn_match_addr(daddr, ifa->ifa_local);
852 if (ret > best_match)
853 saddr = ifa->ifa_local;
854 if (best_match == 0)
855 saddr = ifa->ifa_local;
856 }
857 read_unlock(&dev_base_lock);
858
859 return saddr;
860 }
861
862 static inline __le16 __dn_fib_res_prefsrc(struct dn_fib_res *res)
863 {
864 return dnet_select_source(DN_FIB_RES_DEV(*res), DN_FIB_RES_GW(*res), res->scope);
865 }
866
867 static inline __le16 dn_fib_rules_map_destination(__le16 daddr, struct dn_fib_res *res)
868 {
869 __le16 mask = dnet_make_mask(res->prefixlen);
870 return (daddr&~mask)|res->fi->fib_nh->nh_gw;
871 }
872
873 static int dn_route_output_slow(struct dst_entry **pprt, const struct flowi *oldflp, int try_hard)
874 {
875 struct flowi fl = { .nl_u = { .dn_u =
876 { .daddr = oldflp->fld_dst,
877 .saddr = oldflp->fld_src,
878 .scope = RT_SCOPE_UNIVERSE,
879 } },
880 .mark = oldflp->mark,
881 .iif = init_net.loopback_dev->ifindex,
882 .oif = oldflp->oif };
883 struct dn_route *rt = NULL;
884 struct net_device *dev_out = NULL, *dev;
885 struct neighbour *neigh = NULL;
886 unsigned hash;
887 unsigned flags = 0;
888 struct dn_fib_res res = { .fi = NULL, .type = RTN_UNICAST };
889 int err;
890 int free_res = 0;
891 __le16 gateway = 0;
892
893 if (decnet_debug_level & 16)
894 printk(KERN_DEBUG
895 "dn_route_output_slow: dst=%04x src=%04x mark=%d"
896 " iif=%d oif=%d\n", le16_to_cpu(oldflp->fld_dst),
897 le16_to_cpu(oldflp->fld_src),
898 oldflp->mark, init_net.loopback_dev->ifindex, oldflp->oif);
899
900 /* If we have an output interface, verify its a DECnet device */
901 if (oldflp->oif) {
902 dev_out = dev_get_by_index(&init_net, oldflp->oif);
903 err = -ENODEV;
904 if (dev_out && dev_out->dn_ptr == NULL) {
905 dev_put(dev_out);
906 dev_out = NULL;
907 }
908 if (dev_out == NULL)
909 goto out;
910 }
911
912 /* If we have a source address, verify that its a local address */
913 if (oldflp->fld_src) {
914 err = -EADDRNOTAVAIL;
915
916 if (dev_out) {
917 if (dn_dev_islocal(dev_out, oldflp->fld_src))
918 goto source_ok;
919 dev_put(dev_out);
920 goto out;
921 }
922 rcu_read_lock();
923 for_each_netdev_rcu(&init_net, dev) {
924 if (!dev->dn_ptr)
925 continue;
926 if (!dn_dev_islocal(dev, oldflp->fld_src))
927 continue;
928 if ((dev->flags & IFF_LOOPBACK) &&
929 oldflp->fld_dst &&
930 !dn_dev_islocal(dev, oldflp->fld_dst))
931 continue;
932
933 dev_out = dev;
934 break;
935 }
936 rcu_read_unlock();
937 if (dev_out == NULL)
938 goto out;
939 dev_hold(dev_out);
940 source_ok:
941 ;
942 }
943
944 /* No destination? Assume its local */
945 if (!fl.fld_dst) {
946 fl.fld_dst = fl.fld_src;
947
948 err = -EADDRNOTAVAIL;
949 if (dev_out)
950 dev_put(dev_out);
951 dev_out = init_net.loopback_dev;
952 dev_hold(dev_out);
953 if (!fl.fld_dst) {
954 fl.fld_dst =
955 fl.fld_src = dnet_select_source(dev_out, 0,
956 RT_SCOPE_HOST);
957 if (!fl.fld_dst)
958 goto out;
959 }
960 fl.oif = init_net.loopback_dev->ifindex;
961 res.type = RTN_LOCAL;
962 goto make_route;
963 }
964
965 if (decnet_debug_level & 16)
966 printk(KERN_DEBUG
967 "dn_route_output_slow: initial checks complete."
968 " dst=%o4x src=%04x oif=%d try_hard=%d\n",
969 le16_to_cpu(fl.fld_dst), le16_to_cpu(fl.fld_src),
970 fl.oif, try_hard);
971
972 /*
973 * N.B. If the kernel is compiled without router support then
974 * dn_fib_lookup() will evaluate to non-zero so this if () block
975 * will always be executed.
976 */
977 err = -ESRCH;
978 if (try_hard || (err = dn_fib_lookup(&fl, &res)) != 0) {
979 struct dn_dev *dn_db;
980 if (err != -ESRCH)
981 goto out;
982 /*
983 * Here the fallback is basically the standard algorithm for
984 * routing in endnodes which is described in the DECnet routing
985 * docs
986 *
987 * If we are not trying hard, look in neighbour cache.
988 * The result is tested to ensure that if a specific output
989 * device/source address was requested, then we honour that
990 * here
991 */
992 if (!try_hard) {
993 neigh = neigh_lookup_nodev(&dn_neigh_table, &init_net, &fl.fld_dst);
994 if (neigh) {
995 if ((oldflp->oif &&
996 (neigh->dev->ifindex != oldflp->oif)) ||
997 (oldflp->fld_src &&
998 (!dn_dev_islocal(neigh->dev,
999 oldflp->fld_src)))) {
1000 neigh_release(neigh);
1001 neigh = NULL;
1002 } else {
1003 if (dev_out)
1004 dev_put(dev_out);
1005 if (dn_dev_islocal(neigh->dev, fl.fld_dst)) {
1006 dev_out = init_net.loopback_dev;
1007 res.type = RTN_LOCAL;
1008 } else {
1009 dev_out = neigh->dev;
1010 }
1011 dev_hold(dev_out);
1012 goto select_source;
1013 }
1014 }
1015 }
1016
1017 /* Not there? Perhaps its a local address */
1018 if (dev_out == NULL)
1019 dev_out = dn_dev_get_default();
1020 err = -ENODEV;
1021 if (dev_out == NULL)
1022 goto out;
1023 dn_db = dev_out->dn_ptr;
1024 /* Possible improvement - check all devices for local addr */
1025 if (dn_dev_islocal(dev_out, fl.fld_dst)) {
1026 dev_put(dev_out);
1027 dev_out = init_net.loopback_dev;
1028 dev_hold(dev_out);
1029 res.type = RTN_LOCAL;
1030 goto select_source;
1031 }
1032 /* Not local either.... try sending it to the default router */
1033 neigh = neigh_clone(dn_db->router);
1034 BUG_ON(neigh && neigh->dev != dev_out);
1035
1036 /* Ok then, we assume its directly connected and move on */
1037 select_source:
1038 if (neigh)
1039 gateway = ((struct dn_neigh *)neigh)->addr;
1040 if (gateway == 0)
1041 gateway = fl.fld_dst;
1042 if (fl.fld_src == 0) {
1043 fl.fld_src = dnet_select_source(dev_out, gateway,
1044 res.type == RTN_LOCAL ?
1045 RT_SCOPE_HOST :
1046 RT_SCOPE_LINK);
1047 if (fl.fld_src == 0 && res.type != RTN_LOCAL)
1048 goto e_addr;
1049 }
1050 fl.oif = dev_out->ifindex;
1051 goto make_route;
1052 }
1053 free_res = 1;
1054
1055 if (res.type == RTN_NAT)
1056 goto e_inval;
1057
1058 if (res.type == RTN_LOCAL) {
1059 if (!fl.fld_src)
1060 fl.fld_src = fl.fld_dst;
1061 if (dev_out)
1062 dev_put(dev_out);
1063 dev_out = init_net.loopback_dev;
1064 dev_hold(dev_out);
1065 fl.oif = dev_out->ifindex;
1066 if (res.fi)
1067 dn_fib_info_put(res.fi);
1068 res.fi = NULL;
1069 goto make_route;
1070 }
1071
1072 if (res.fi->fib_nhs > 1 && fl.oif == 0)
1073 dn_fib_select_multipath(&fl, &res);
1074
1075 /*
1076 * We could add some logic to deal with default routes here and
1077 * get rid of some of the special casing above.
1078 */
1079
1080 if (!fl.fld_src)
1081 fl.fld_src = DN_FIB_RES_PREFSRC(res);
1082
1083 if (dev_out)
1084 dev_put(dev_out);
1085 dev_out = DN_FIB_RES_DEV(res);
1086 dev_hold(dev_out);
1087 fl.oif = dev_out->ifindex;
1088 gateway = DN_FIB_RES_GW(res);
1089
1090 make_route:
1091 if (dev_out->flags & IFF_LOOPBACK)
1092 flags |= RTCF_LOCAL;
1093
1094 rt = dst_alloc(&dn_dst_ops);
1095 if (rt == NULL)
1096 goto e_nobufs;
1097
1098 atomic_set(&rt->dst.__refcnt, 1);
1099 rt->dst.flags = DST_HOST;
1100
1101 rt->fl.fld_src = oldflp->fld_src;
1102 rt->fl.fld_dst = oldflp->fld_dst;
1103 rt->fl.oif = oldflp->oif;
1104 rt->fl.iif = 0;
1105 rt->fl.mark = oldflp->mark;
1106
1107 rt->rt_saddr = fl.fld_src;
1108 rt->rt_daddr = fl.fld_dst;
1109 rt->rt_gateway = gateway ? gateway : fl.fld_dst;
1110 rt->rt_local_src = fl.fld_src;
1111
1112 rt->rt_dst_map = fl.fld_dst;
1113 rt->rt_src_map = fl.fld_src;
1114
1115 rt->dst.dev = dev_out;
1116 dev_hold(dev_out);
1117 rt->dst.neighbour = neigh;
1118 neigh = NULL;
1119
1120 rt->dst.lastuse = jiffies;
1121 rt->dst.output = dn_output;
1122 rt->dst.input = dn_rt_bug;
1123 rt->rt_flags = flags;
1124 if (flags & RTCF_LOCAL)
1125 rt->dst.input = dn_nsp_rx;
1126
1127 err = dn_rt_set_next_hop(rt, &res);
1128 if (err)
1129 goto e_neighbour;
1130
1131 hash = dn_hash(rt->fl.fld_src, rt->fl.fld_dst);
1132 dn_insert_route(rt, hash, (struct dn_route **)pprt);
1133
1134 done:
1135 if (neigh)
1136 neigh_release(neigh);
1137 if (free_res)
1138 dn_fib_res_put(&res);
1139 if (dev_out)
1140 dev_put(dev_out);
1141 out:
1142 return err;
1143
1144 e_addr:
1145 err = -EADDRNOTAVAIL;
1146 goto done;
1147 e_inval:
1148 err = -EINVAL;
1149 goto done;
1150 e_nobufs:
1151 err = -ENOBUFS;
1152 goto done;
1153 e_neighbour:
1154 dst_free(&rt->dst);
1155 goto e_nobufs;
1156 }
1157
1158
1159 /*
1160 * N.B. The flags may be moved into the flowi at some future stage.
1161 */
1162 static int __dn_route_output_key(struct dst_entry **pprt, const struct flowi *flp, int flags)
1163 {
1164 unsigned hash = dn_hash(flp->fld_src, flp->fld_dst);
1165 struct dn_route *rt = NULL;
1166
1167 if (!(flags & MSG_TRYHARD)) {
1168 rcu_read_lock_bh();
1169 for (rt = rcu_dereference_bh(dn_rt_hash_table[hash].chain); rt;
1170 rt = rcu_dereference_bh(rt->dst.dn_next)) {
1171 if ((flp->fld_dst == rt->fl.fld_dst) &&
1172 (flp->fld_src == rt->fl.fld_src) &&
1173 (flp->mark == rt->fl.mark) &&
1174 (rt->fl.iif == 0) &&
1175 (rt->fl.oif == flp->oif)) {
1176 dst_use(&rt->dst, jiffies);
1177 rcu_read_unlock_bh();
1178 *pprt = &rt->dst;
1179 return 0;
1180 }
1181 }
1182 rcu_read_unlock_bh();
1183 }
1184
1185 return dn_route_output_slow(pprt, flp, flags);
1186 }
1187
1188 static int dn_route_output_key(struct dst_entry **pprt, struct flowi *flp, int flags)
1189 {
1190 int err;
1191
1192 err = __dn_route_output_key(pprt, flp, flags);
1193 if (err == 0 && flp->proto) {
1194 err = xfrm_lookup(&init_net, pprt, flp, NULL, 0);
1195 }
1196 return err;
1197 }
1198
1199 int dn_route_output_sock(struct dst_entry **pprt, struct flowi *fl, struct sock *sk, int flags)
1200 {
1201 int err;
1202
1203 err = __dn_route_output_key(pprt, fl, flags & MSG_TRYHARD);
1204 if (err == 0 && fl->proto) {
1205 err = xfrm_lookup(&init_net, pprt, fl, sk,
1206 (flags & MSG_DONTWAIT) ? 0 : XFRM_LOOKUP_WAIT);
1207 }
1208 return err;
1209 }
1210
1211 static int dn_route_input_slow(struct sk_buff *skb)
1212 {
1213 struct dn_route *rt = NULL;
1214 struct dn_skb_cb *cb = DN_SKB_CB(skb);
1215 struct net_device *in_dev = skb->dev;
1216 struct net_device *out_dev = NULL;
1217 struct dn_dev *dn_db;
1218 struct neighbour *neigh = NULL;
1219 unsigned hash;
1220 int flags = 0;
1221 __le16 gateway = 0;
1222 __le16 local_src = 0;
1223 struct flowi fl = { .nl_u = { .dn_u =
1224 { .daddr = cb->dst,
1225 .saddr = cb->src,
1226 .scope = RT_SCOPE_UNIVERSE,
1227 } },
1228 .mark = skb->mark,
1229 .iif = skb->dev->ifindex };
1230 struct dn_fib_res res = { .fi = NULL, .type = RTN_UNREACHABLE };
1231 int err = -EINVAL;
1232 int free_res = 0;
1233
1234 dev_hold(in_dev);
1235
1236 if ((dn_db = in_dev->dn_ptr) == NULL)
1237 goto out;
1238
1239 /* Zero source addresses are not allowed */
1240 if (fl.fld_src == 0)
1241 goto out;
1242
1243 /*
1244 * In this case we've just received a packet from a source
1245 * outside ourselves pretending to come from us. We don't
1246 * allow it any further to prevent routing loops, spoofing and
1247 * other nasties. Loopback packets already have the dst attached
1248 * so this only affects packets which have originated elsewhere.
1249 */
1250 err = -ENOTUNIQ;
1251 if (dn_dev_islocal(in_dev, cb->src))
1252 goto out;
1253
1254 err = dn_fib_lookup(&fl, &res);
1255 if (err) {
1256 if (err != -ESRCH)
1257 goto out;
1258 /*
1259 * Is the destination us ?
1260 */
1261 if (!dn_dev_islocal(in_dev, cb->dst))
1262 goto e_inval;
1263
1264 res.type = RTN_LOCAL;
1265 } else {
1266 __le16 src_map = fl.fld_src;
1267 free_res = 1;
1268
1269 out_dev = DN_FIB_RES_DEV(res);
1270 if (out_dev == NULL) {
1271 if (net_ratelimit())
1272 printk(KERN_CRIT "Bug in dn_route_input_slow() "
1273 "No output device\n");
1274 goto e_inval;
1275 }
1276 dev_hold(out_dev);
1277
1278 if (res.r)
1279 src_map = fl.fld_src; /* no NAT support for now */
1280
1281 gateway = DN_FIB_RES_GW(res);
1282 if (res.type == RTN_NAT) {
1283 fl.fld_dst = dn_fib_rules_map_destination(fl.fld_dst, &res);
1284 dn_fib_res_put(&res);
1285 free_res = 0;
1286 if (dn_fib_lookup(&fl, &res))
1287 goto e_inval;
1288 free_res = 1;
1289 if (res.type != RTN_UNICAST)
1290 goto e_inval;
1291 flags |= RTCF_DNAT;
1292 gateway = fl.fld_dst;
1293 }
1294 fl.fld_src = src_map;
1295 }
1296
1297 switch(res.type) {
1298 case RTN_UNICAST:
1299 /*
1300 * Forwarding check here, we only check for forwarding
1301 * being turned off, if you want to only forward intra
1302 * area, its up to you to set the routing tables up
1303 * correctly.
1304 */
1305 if (dn_db->parms.forwarding == 0)
1306 goto e_inval;
1307
1308 if (res.fi->fib_nhs > 1 && fl.oif == 0)
1309 dn_fib_select_multipath(&fl, &res);
1310
1311 /*
1312 * Check for out_dev == in_dev. We use the RTCF_DOREDIRECT
1313 * flag as a hint to set the intra-ethernet bit when
1314 * forwarding. If we've got NAT in operation, we don't do
1315 * this optimisation.
1316 */
1317 if (out_dev == in_dev && !(flags & RTCF_NAT))
1318 flags |= RTCF_DOREDIRECT;
1319
1320 local_src = DN_FIB_RES_PREFSRC(res);
1321
1322 case RTN_BLACKHOLE:
1323 case RTN_UNREACHABLE:
1324 break;
1325 case RTN_LOCAL:
1326 flags |= RTCF_LOCAL;
1327 fl.fld_src = cb->dst;
1328 fl.fld_dst = cb->src;
1329
1330 /* Routing tables gave us a gateway */
1331 if (gateway)
1332 goto make_route;
1333
1334 /* Packet was intra-ethernet, so we know its on-link */
1335 if (cb->rt_flags & DN_RT_F_IE) {
1336 gateway = cb->src;
1337 flags |= RTCF_DIRECTSRC;
1338 goto make_route;
1339 }
1340
1341 /* Use the default router if there is one */
1342 neigh = neigh_clone(dn_db->router);
1343 if (neigh) {
1344 gateway = ((struct dn_neigh *)neigh)->addr;
1345 goto make_route;
1346 }
1347
1348 /* Close eyes and pray */
1349 gateway = cb->src;
1350 flags |= RTCF_DIRECTSRC;
1351 goto make_route;
1352 default:
1353 goto e_inval;
1354 }
1355
1356 make_route:
1357 rt = dst_alloc(&dn_dst_ops);
1358 if (rt == NULL)
1359 goto e_nobufs;
1360
1361 rt->rt_saddr = fl.fld_src;
1362 rt->rt_daddr = fl.fld_dst;
1363 rt->rt_gateway = fl.fld_dst;
1364 if (gateway)
1365 rt->rt_gateway = gateway;
1366 rt->rt_local_src = local_src ? local_src : rt->rt_saddr;
1367
1368 rt->rt_dst_map = fl.fld_dst;
1369 rt->rt_src_map = fl.fld_src;
1370
1371 rt->fl.fld_src = cb->src;
1372 rt->fl.fld_dst = cb->dst;
1373 rt->fl.oif = 0;
1374 rt->fl.iif = in_dev->ifindex;
1375 rt->fl.mark = fl.mark;
1376
1377 rt->dst.flags = DST_HOST;
1378 rt->dst.neighbour = neigh;
1379 rt->dst.dev = out_dev;
1380 rt->dst.lastuse = jiffies;
1381 rt->dst.output = dn_rt_bug;
1382 switch(res.type) {
1383 case RTN_UNICAST:
1384 rt->dst.input = dn_forward;
1385 break;
1386 case RTN_LOCAL:
1387 rt->dst.output = dn_output;
1388 rt->dst.input = dn_nsp_rx;
1389 rt->dst.dev = in_dev;
1390 flags |= RTCF_LOCAL;
1391 break;
1392 default:
1393 case RTN_UNREACHABLE:
1394 case RTN_BLACKHOLE:
1395 rt->dst.input = dst_discard;
1396 }
1397 rt->rt_flags = flags;
1398 if (rt->dst.dev)
1399 dev_hold(rt->dst.dev);
1400
1401 err = dn_rt_set_next_hop(rt, &res);
1402 if (err)
1403 goto e_neighbour;
1404
1405 hash = dn_hash(rt->fl.fld_src, rt->fl.fld_dst);
1406 dn_insert_route(rt, hash, &rt);
1407 skb_dst_set(skb, &rt->dst);
1408
1409 done:
1410 if (neigh)
1411 neigh_release(neigh);
1412 if (free_res)
1413 dn_fib_res_put(&res);
1414 dev_put(in_dev);
1415 if (out_dev)
1416 dev_put(out_dev);
1417 out:
1418 return err;
1419
1420 e_inval:
1421 err = -EINVAL;
1422 goto done;
1423
1424 e_nobufs:
1425 err = -ENOBUFS;
1426 goto done;
1427
1428 e_neighbour:
1429 dst_free(&rt->dst);
1430 goto done;
1431 }
1432
1433 static int dn_route_input(struct sk_buff *skb)
1434 {
1435 struct dn_route *rt;
1436 struct dn_skb_cb *cb = DN_SKB_CB(skb);
1437 unsigned hash = dn_hash(cb->src, cb->dst);
1438
1439 if (skb_dst(skb))
1440 return 0;
1441
1442 rcu_read_lock();
1443 for(rt = rcu_dereference(dn_rt_hash_table[hash].chain); rt != NULL;
1444 rt = rcu_dereference(rt->dst.dn_next)) {
1445 if ((rt->fl.fld_src == cb->src) &&
1446 (rt->fl.fld_dst == cb->dst) &&
1447 (rt->fl.oif == 0) &&
1448 (rt->fl.mark == skb->mark) &&
1449 (rt->fl.iif == cb->iif)) {
1450 dst_use(&rt->dst, jiffies);
1451 rcu_read_unlock();
1452 skb_dst_set(skb, (struct dst_entry *)rt);
1453 return 0;
1454 }
1455 }
1456 rcu_read_unlock();
1457
1458 return dn_route_input_slow(skb);
1459 }
1460
1461 static int dn_rt_fill_info(struct sk_buff *skb, u32 pid, u32 seq,
1462 int event, int nowait, unsigned int flags)
1463 {
1464 struct dn_route *rt = (struct dn_route *)skb_dst(skb);
1465 struct rtmsg *r;
1466 struct nlmsghdr *nlh;
1467 unsigned char *b = skb_tail_pointer(skb);
1468 long expires;
1469
1470 nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*r), flags);
1471 r = NLMSG_DATA(nlh);
1472 r->rtm_family = AF_DECnet;
1473 r->rtm_dst_len = 16;
1474 r->rtm_src_len = 0;
1475 r->rtm_tos = 0;
1476 r->rtm_table = RT_TABLE_MAIN;
1477 RTA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
1478 r->rtm_type = rt->rt_type;
1479 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
1480 r->rtm_scope = RT_SCOPE_UNIVERSE;
1481 r->rtm_protocol = RTPROT_UNSPEC;
1482 if (rt->rt_flags & RTCF_NOTIFY)
1483 r->rtm_flags |= RTM_F_NOTIFY;
1484 RTA_PUT(skb, RTA_DST, 2, &rt->rt_daddr);
1485 if (rt->fl.fld_src) {
1486 r->rtm_src_len = 16;
1487 RTA_PUT(skb, RTA_SRC, 2, &rt->fl.fld_src);
1488 }
1489 if (rt->dst.dev)
1490 RTA_PUT(skb, RTA_OIF, sizeof(int), &rt->dst.dev->ifindex);
1491 /*
1492 * Note to self - change this if input routes reverse direction when
1493 * they deal only with inputs and not with replies like they do
1494 * currently.
1495 */
1496 RTA_PUT(skb, RTA_PREFSRC, 2, &rt->rt_local_src);
1497 if (rt->rt_daddr != rt->rt_gateway)
1498 RTA_PUT(skb, RTA_GATEWAY, 2, &rt->rt_gateway);
1499 if (rtnetlink_put_metrics(skb, rt->dst.metrics) < 0)
1500 goto rtattr_failure;
1501 expires = rt->dst.expires ? rt->dst.expires - jiffies : 0;
1502 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, 0, 0, expires,
1503 rt->dst.error) < 0)
1504 goto rtattr_failure;
1505 if (rt->fl.iif)
1506 RTA_PUT(skb, RTA_IIF, sizeof(int), &rt->fl.iif);
1507
1508 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1509 return skb->len;
1510
1511 nlmsg_failure:
1512 rtattr_failure:
1513 nlmsg_trim(skb, b);
1514 return -1;
1515 }
1516
1517 /*
1518 * This is called by both endnodes and routers now.
1519 */
1520 static int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, void *arg)
1521 {
1522 struct net *net = sock_net(in_skb->sk);
1523 struct rtattr **rta = arg;
1524 struct rtmsg *rtm = NLMSG_DATA(nlh);
1525 struct dn_route *rt = NULL;
1526 struct dn_skb_cb *cb;
1527 int err;
1528 struct sk_buff *skb;
1529 struct flowi fl;
1530
1531 if (!net_eq(net, &init_net))
1532 return -EINVAL;
1533
1534 memset(&fl, 0, sizeof(fl));
1535 fl.proto = DNPROTO_NSP;
1536
1537 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1538 if (skb == NULL)
1539 return -ENOBUFS;
1540 skb_reset_mac_header(skb);
1541 cb = DN_SKB_CB(skb);
1542
1543 if (rta[RTA_SRC-1])
1544 memcpy(&fl.fld_src, RTA_DATA(rta[RTA_SRC-1]), 2);
1545 if (rta[RTA_DST-1])
1546 memcpy(&fl.fld_dst, RTA_DATA(rta[RTA_DST-1]), 2);
1547 if (rta[RTA_IIF-1])
1548 memcpy(&fl.iif, RTA_DATA(rta[RTA_IIF-1]), sizeof(int));
1549
1550 if (fl.iif) {
1551 struct net_device *dev;
1552 if ((dev = dev_get_by_index(&init_net, fl.iif)) == NULL) {
1553 kfree_skb(skb);
1554 return -ENODEV;
1555 }
1556 if (!dev->dn_ptr) {
1557 dev_put(dev);
1558 kfree_skb(skb);
1559 return -ENODEV;
1560 }
1561 skb->protocol = htons(ETH_P_DNA_RT);
1562 skb->dev = dev;
1563 cb->src = fl.fld_src;
1564 cb->dst = fl.fld_dst;
1565 local_bh_disable();
1566 err = dn_route_input(skb);
1567 local_bh_enable();
1568 memset(cb, 0, sizeof(struct dn_skb_cb));
1569 rt = (struct dn_route *)skb_dst(skb);
1570 if (!err && -rt->dst.error)
1571 err = rt->dst.error;
1572 } else {
1573 int oif = 0;
1574 if (rta[RTA_OIF - 1])
1575 memcpy(&oif, RTA_DATA(rta[RTA_OIF - 1]), sizeof(int));
1576 fl.oif = oif;
1577 err = dn_route_output_key((struct dst_entry **)&rt, &fl, 0);
1578 }
1579
1580 if (skb->dev)
1581 dev_put(skb->dev);
1582 skb->dev = NULL;
1583 if (err)
1584 goto out_free;
1585 skb_dst_set(skb, &rt->dst);
1586 if (rtm->rtm_flags & RTM_F_NOTIFY)
1587 rt->rt_flags |= RTCF_NOTIFY;
1588
1589 err = dn_rt_fill_info(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, RTM_NEWROUTE, 0, 0);
1590
1591 if (err == 0)
1592 goto out_free;
1593 if (err < 0) {
1594 err = -EMSGSIZE;
1595 goto out_free;
1596 }
1597
1598 return rtnl_unicast(skb, &init_net, NETLINK_CB(in_skb).pid);
1599
1600 out_free:
1601 kfree_skb(skb);
1602 return err;
1603 }
1604
1605 /*
1606 * For routers, this is called from dn_fib_dump, but for endnodes its
1607 * called directly from the rtnetlink dispatch table.
1608 */
1609 int dn_cache_dump(struct sk_buff *skb, struct netlink_callback *cb)
1610 {
1611 struct net *net = sock_net(skb->sk);
1612 struct dn_route *rt;
1613 int h, s_h;
1614 int idx, s_idx;
1615
1616 if (!net_eq(net, &init_net))
1617 return 0;
1618
1619 if (NLMSG_PAYLOAD(cb->nlh, 0) < sizeof(struct rtmsg))
1620 return -EINVAL;
1621 if (!(((struct rtmsg *)NLMSG_DATA(cb->nlh))->rtm_flags&RTM_F_CLONED))
1622 return 0;
1623
1624 s_h = cb->args[0];
1625 s_idx = idx = cb->args[1];
1626 for(h = 0; h <= dn_rt_hash_mask; h++) {
1627 if (h < s_h)
1628 continue;
1629 if (h > s_h)
1630 s_idx = 0;
1631 rcu_read_lock_bh();
1632 for(rt = rcu_dereference_bh(dn_rt_hash_table[h].chain), idx = 0;
1633 rt;
1634 rt = rcu_dereference_bh(rt->dst.dn_next), idx++) {
1635 if (idx < s_idx)
1636 continue;
1637 skb_dst_set(skb, dst_clone(&rt->dst));
1638 if (dn_rt_fill_info(skb, NETLINK_CB(cb->skb).pid,
1639 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
1640 1, NLM_F_MULTI) <= 0) {
1641 skb_dst_drop(skb);
1642 rcu_read_unlock_bh();
1643 goto done;
1644 }
1645 skb_dst_drop(skb);
1646 }
1647 rcu_read_unlock_bh();
1648 }
1649
1650 done:
1651 cb->args[0] = h;
1652 cb->args[1] = idx;
1653 return skb->len;
1654 }
1655
1656 #ifdef CONFIG_PROC_FS
1657 struct dn_rt_cache_iter_state {
1658 int bucket;
1659 };
1660
1661 static struct dn_route *dn_rt_cache_get_first(struct seq_file *seq)
1662 {
1663 struct dn_route *rt = NULL;
1664 struct dn_rt_cache_iter_state *s = seq->private;
1665
1666 for(s->bucket = dn_rt_hash_mask; s->bucket >= 0; --s->bucket) {
1667 rcu_read_lock_bh();
1668 rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1669 if (rt)
1670 break;
1671 rcu_read_unlock_bh();
1672 }
1673 return rt;
1674 }
1675
1676 static struct dn_route *dn_rt_cache_get_next(struct seq_file *seq, struct dn_route *rt)
1677 {
1678 struct dn_rt_cache_iter_state *s = seq->private;
1679
1680 rt = rt->dst.dn_next;
1681 while(!rt) {
1682 rcu_read_unlock_bh();
1683 if (--s->bucket < 0)
1684 break;
1685 rcu_read_lock_bh();
1686 rt = dn_rt_hash_table[s->bucket].chain;
1687 }
1688 return rcu_dereference_bh(rt);
1689 }
1690
1691 static void *dn_rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
1692 {
1693 struct dn_route *rt = dn_rt_cache_get_first(seq);
1694
1695 if (rt) {
1696 while(*pos && (rt = dn_rt_cache_get_next(seq, rt)))
1697 --*pos;
1698 }
1699 return *pos ? NULL : rt;
1700 }
1701
1702 static void *dn_rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1703 {
1704 struct dn_route *rt = dn_rt_cache_get_next(seq, v);
1705 ++*pos;
1706 return rt;
1707 }
1708
1709 static void dn_rt_cache_seq_stop(struct seq_file *seq, void *v)
1710 {
1711 if (v)
1712 rcu_read_unlock_bh();
1713 }
1714
1715 static int dn_rt_cache_seq_show(struct seq_file *seq, void *v)
1716 {
1717 struct dn_route *rt = v;
1718 char buf1[DN_ASCBUF_LEN], buf2[DN_ASCBUF_LEN];
1719
1720 seq_printf(seq, "%-8s %-7s %-7s %04d %04d %04d\n",
1721 rt->dst.dev ? rt->dst.dev->name : "*",
1722 dn_addr2asc(le16_to_cpu(rt->rt_daddr), buf1),
1723 dn_addr2asc(le16_to_cpu(rt->rt_saddr), buf2),
1724 atomic_read(&rt->dst.__refcnt),
1725 rt->dst.__use,
1726 (int) dst_metric(&rt->dst, RTAX_RTT));
1727 return 0;
1728 }
1729
1730 static const struct seq_operations dn_rt_cache_seq_ops = {
1731 .start = dn_rt_cache_seq_start,
1732 .next = dn_rt_cache_seq_next,
1733 .stop = dn_rt_cache_seq_stop,
1734 .show = dn_rt_cache_seq_show,
1735 };
1736
1737 static int dn_rt_cache_seq_open(struct inode *inode, struct file *file)
1738 {
1739 return seq_open_private(file, &dn_rt_cache_seq_ops,
1740 sizeof(struct dn_rt_cache_iter_state));
1741 }
1742
1743 static const struct file_operations dn_rt_cache_seq_fops = {
1744 .owner = THIS_MODULE,
1745 .open = dn_rt_cache_seq_open,
1746 .read = seq_read,
1747 .llseek = seq_lseek,
1748 .release = seq_release_private,
1749 };
1750
1751 #endif /* CONFIG_PROC_FS */
1752
1753 void __init dn_route_init(void)
1754 {
1755 int i, goal, order;
1756
1757 dn_dst_ops.kmem_cachep =
1758 kmem_cache_create("dn_dst_cache", sizeof(struct dn_route), 0,
1759 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
1760 dst_entries_init(&dn_dst_ops);
1761 setup_timer(&dn_route_timer, dn_dst_check_expire, 0);
1762 dn_route_timer.expires = jiffies + decnet_dst_gc_interval * HZ;
1763 add_timer(&dn_route_timer);
1764
1765 goal = totalram_pages >> (26 - PAGE_SHIFT);
1766
1767 for(order = 0; (1UL << order) < goal; order++)
1768 /* NOTHING */;
1769
1770 /*
1771 * Only want 1024 entries max, since the table is very, very unlikely
1772 * to be larger than that.
1773 */
1774 while(order && ((((1UL << order) * PAGE_SIZE) /
1775 sizeof(struct dn_rt_hash_bucket)) >= 2048))
1776 order--;
1777
1778 do {
1779 dn_rt_hash_mask = (1UL << order) * PAGE_SIZE /
1780 sizeof(struct dn_rt_hash_bucket);
1781 while(dn_rt_hash_mask & (dn_rt_hash_mask - 1))
1782 dn_rt_hash_mask--;
1783 dn_rt_hash_table = (struct dn_rt_hash_bucket *)
1784 __get_free_pages(GFP_ATOMIC, order);
1785 } while (dn_rt_hash_table == NULL && --order > 0);
1786
1787 if (!dn_rt_hash_table)
1788 panic("Failed to allocate DECnet route cache hash table\n");
1789
1790 printk(KERN_INFO
1791 "DECnet: Routing cache hash table of %u buckets, %ldKbytes\n",
1792 dn_rt_hash_mask,
1793 (long)(dn_rt_hash_mask*sizeof(struct dn_rt_hash_bucket))/1024);
1794
1795 dn_rt_hash_mask--;
1796 for(i = 0; i <= dn_rt_hash_mask; i++) {
1797 spin_lock_init(&dn_rt_hash_table[i].lock);
1798 dn_rt_hash_table[i].chain = NULL;
1799 }
1800
1801 dn_dst_ops.gc_thresh = (dn_rt_hash_mask + 1);
1802
1803 proc_net_fops_create(&init_net, "decnet_cache", S_IRUGO, &dn_rt_cache_seq_fops);
1804
1805 #ifdef CONFIG_DECNET_ROUTER
1806 rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute, dn_fib_dump);
1807 #else
1808 rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute,
1809 dn_cache_dump);
1810 #endif
1811 }
1812
1813 void __exit dn_route_cleanup(void)
1814 {
1815 del_timer(&dn_route_timer);
1816 dn_run_flush(0);
1817
1818 proc_net_remove(&init_net, "decnet_cache");
1819 dst_entries_destroy(&dn_dst_ops);
1820 }
1821
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