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Merge branch 'linus' into perf/core
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / net / decnet / dn_route.c
blob9f09d4fc2880deaae856dbfff675349723ddf07a
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 __rcu *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 unsigned int dn_dst_default_advmss(const struct dst_entry *dst);
114 static unsigned int dn_dst_default_mtu(const struct dst_entry *dst);
115 static void dn_dst_destroy(struct dst_entry *);
116 static struct dst_entry *dn_dst_negative_advice(struct dst_entry *);
117 static void dn_dst_link_failure(struct sk_buff *);
118 static void dn_dst_update_pmtu(struct dst_entry *dst, u32 mtu);
119 static int dn_route_input(struct sk_buff *);
120 static void dn_run_flush(unsigned long dummy);
121
122 static struct dn_rt_hash_bucket *dn_rt_hash_table;
123 static unsigned dn_rt_hash_mask;
124
125 static struct timer_list dn_route_timer;
126 static DEFINE_TIMER(dn_rt_flush_timer, dn_run_flush, 0, 0);
127 int decnet_dst_gc_interval = 2;
128
129 static struct dst_ops dn_dst_ops = {
130 .family = PF_DECnet,
131 .protocol = cpu_to_be16(ETH_P_DNA_RT),
132 .gc_thresh = 128,
133 .gc = dn_dst_gc,
134 .check = dn_dst_check,
135 .default_advmss = dn_dst_default_advmss,
136 .default_mtu = dn_dst_default_mtu,
137 .cow_metrics = dst_cow_metrics_generic,
138 .destroy = dn_dst_destroy,
139 .negative_advice = dn_dst_negative_advice,
140 .link_failure = dn_dst_link_failure,
141 .update_pmtu = dn_dst_update_pmtu,
142 };
143
144 static void dn_dst_destroy(struct dst_entry *dst)
145 {
146 dst_destroy_metrics_generic(dst);
147 }
148
149 static __inline__ unsigned dn_hash(__le16 src, __le16 dst)
150 {
151 __u16 tmp = (__u16 __force)(src ^ dst);
152 tmp ^= (tmp >> 3);
153 tmp ^= (tmp >> 5);
154 tmp ^= (tmp >> 10);
155 return dn_rt_hash_mask & (unsigned)tmp;
156 }
157
158 static inline void dnrt_free(struct dn_route *rt)
159 {
160 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
161 }
162
163 static inline void dnrt_drop(struct dn_route *rt)
164 {
165 dst_release(&rt->dst);
166 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
167 }
168
169 static void dn_dst_check_expire(unsigned long dummy)
170 {
171 int i;
172 struct dn_route *rt;
173 struct dn_route __rcu **rtp;
174 unsigned long now = jiffies;
175 unsigned long expire = 120 * HZ;
176
177 for (i = 0; i <= dn_rt_hash_mask; i++) {
178 rtp = &dn_rt_hash_table[i].chain;
179
180 spin_lock(&dn_rt_hash_table[i].lock);
181 while ((rt = rcu_dereference_protected(*rtp,
182 lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) {
183 if (atomic_read(&rt->dst.__refcnt) ||
184 (now - rt->dst.lastuse) < expire) {
185 rtp = &rt->dst.dn_next;
186 continue;
187 }
188 *rtp = rt->dst.dn_next;
189 rt->dst.dn_next = NULL;
190 dnrt_free(rt);
191 }
192 spin_unlock(&dn_rt_hash_table[i].lock);
193
194 if ((jiffies - now) > 0)
195 break;
196 }
197
198 mod_timer(&dn_route_timer, now + decnet_dst_gc_interval * HZ);
199 }
200
201 static int dn_dst_gc(struct dst_ops *ops)
202 {
203 struct dn_route *rt;
204 struct dn_route __rcu **rtp;
205 int i;
206 unsigned long now = jiffies;
207 unsigned long expire = 10 * HZ;
208
209 for (i = 0; i <= dn_rt_hash_mask; i++) {
210
211 spin_lock_bh(&dn_rt_hash_table[i].lock);
212 rtp = &dn_rt_hash_table[i].chain;
213
214 while ((rt = rcu_dereference_protected(*rtp,
215 lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) {
216 if (atomic_read(&rt->dst.__refcnt) ||
217 (now - rt->dst.lastuse) < expire) {
218 rtp = &rt->dst.dn_next;
219 continue;
220 }
221 *rtp = rt->dst.dn_next;
222 rt->dst.dn_next = NULL;
223 dnrt_drop(rt);
224 break;
225 }
226 spin_unlock_bh(&dn_rt_hash_table[i].lock);
227 }
228
229 return 0;
230 }
231
232 /*
233 * The decnet standards don't impose a particular minimum mtu, what they
234 * do insist on is that the routing layer accepts a datagram of at least
235 * 230 bytes long. Here we have to subtract the routing header length from
236 * 230 to get the minimum acceptable mtu. If there is no neighbour, then we
237 * assume the worst and use a long header size.
238 *
239 * We update both the mtu and the advertised mss (i.e. the segment size we
240 * advertise to the other end).
241 */
242 static void dn_dst_update_pmtu(struct dst_entry *dst, u32 mtu)
243 {
244 u32 min_mtu = 230;
245 struct dn_dev *dn = dst->neighbour ?
246 rcu_dereference_raw(dst->neighbour->dev->dn_ptr) : NULL;
247
248 if (dn && dn->use_long == 0)
249 min_mtu -= 6;
250 else
251 min_mtu -= 21;
252
253 if (dst_metric(dst, RTAX_MTU) > mtu && mtu >= min_mtu) {
254 if (!(dst_metric_locked(dst, RTAX_MTU))) {
255 dst_metric_set(dst, RTAX_MTU, mtu);
256 dst_set_expires(dst, dn_rt_mtu_expires);
257 }
258 if (!(dst_metric_locked(dst, RTAX_ADVMSS))) {
259 u32 mss = mtu - DN_MAX_NSP_DATA_HEADER;
260 u32 existing_mss = dst_metric_raw(dst, RTAX_ADVMSS);
261 if (!existing_mss || existing_mss > mss)
262 dst_metric_set(dst, RTAX_ADVMSS, mss);
263 }
264 }
265 }
266
267 /*
268 * When a route has been marked obsolete. (e.g. routing cache flush)
269 */
270 static struct dst_entry *dn_dst_check(struct dst_entry *dst, __u32 cookie)
271 {
272 return NULL;
273 }
274
275 static struct dst_entry *dn_dst_negative_advice(struct dst_entry *dst)
276 {
277 dst_release(dst);
278 return NULL;
279 }
280
281 static void dn_dst_link_failure(struct sk_buff *skb)
282 {
283 }
284
285 static inline int compare_keys(struct flowidn *fl1, struct flowidn *fl2)
286 {
287 return ((fl1->daddr ^ fl2->daddr) |
288 (fl1->saddr ^ fl2->saddr) |
289 (fl1->flowidn_mark ^ fl2->flowidn_mark) |
290 (fl1->flowidn_scope ^ fl2->flowidn_scope) |
291 (fl1->flowidn_oif ^ fl2->flowidn_oif) |
292 (fl1->flowidn_iif ^ fl2->flowidn_iif)) == 0;
293 }
294
295 static int dn_insert_route(struct dn_route *rt, unsigned hash, struct dn_route **rp)
296 {
297 struct dn_route *rth;
298 struct dn_route __rcu **rthp;
299 unsigned long now = jiffies;
300
301 rthp = &dn_rt_hash_table[hash].chain;
302
303 spin_lock_bh(&dn_rt_hash_table[hash].lock);
304 while ((rth = rcu_dereference_protected(*rthp,
305 lockdep_is_held(&dn_rt_hash_table[hash].lock))) != NULL) {
306 if (compare_keys(&rth->fld, &rt->fld)) {
307 /* Put it first */
308 *rthp = rth->dst.dn_next;
309 rcu_assign_pointer(rth->dst.dn_next,
310 dn_rt_hash_table[hash].chain);
311 rcu_assign_pointer(dn_rt_hash_table[hash].chain, rth);
312
313 dst_use(&rth->dst, now);
314 spin_unlock_bh(&dn_rt_hash_table[hash].lock);
315
316 dnrt_drop(rt);
317 *rp = rth;
318 return 0;
319 }
320 rthp = &rth->dst.dn_next;
321 }
322
323 rcu_assign_pointer(rt->dst.dn_next, dn_rt_hash_table[hash].chain);
324 rcu_assign_pointer(dn_rt_hash_table[hash].chain, rt);
325
326 dst_use(&rt->dst, now);
327 spin_unlock_bh(&dn_rt_hash_table[hash].lock);
328 *rp = rt;
329 return 0;
330 }
331
332 static void dn_run_flush(unsigned long dummy)
333 {
334 int i;
335 struct dn_route *rt, *next;
336
337 for (i = 0; i < dn_rt_hash_mask; i++) {
338 spin_lock_bh(&dn_rt_hash_table[i].lock);
339
340 if ((rt = xchg((struct dn_route **)&dn_rt_hash_table[i].chain, NULL)) == NULL)
341 goto nothing_to_declare;
342
343 for(; rt; rt = next) {
344 next = rcu_dereference_raw(rt->dst.dn_next);
345 RCU_INIT_POINTER(rt->dst.dn_next, NULL);
346 dst_free((struct dst_entry *)rt);
347 }
348
349 nothing_to_declare:
350 spin_unlock_bh(&dn_rt_hash_table[i].lock);
351 }
352 }
353
354 static DEFINE_SPINLOCK(dn_rt_flush_lock);
355
356 void dn_rt_cache_flush(int delay)
357 {
358 unsigned long now = jiffies;
359 int user_mode = !in_interrupt();
360
361 if (delay < 0)
362 delay = dn_rt_min_delay;
363
364 spin_lock_bh(&dn_rt_flush_lock);
365
366 if (del_timer(&dn_rt_flush_timer) && delay > 0 && dn_rt_deadline) {
367 long tmo = (long)(dn_rt_deadline - now);
368
369 if (user_mode && tmo < dn_rt_max_delay - dn_rt_min_delay)
370 tmo = 0;
371
372 if (delay > tmo)
373 delay = tmo;
374 }
375
376 if (delay <= 0) {
377 spin_unlock_bh(&dn_rt_flush_lock);
378 dn_run_flush(0);
379 return;
380 }
381
382 if (dn_rt_deadline == 0)
383 dn_rt_deadline = now + dn_rt_max_delay;
384
385 dn_rt_flush_timer.expires = now + delay;
386 add_timer(&dn_rt_flush_timer);
387 spin_unlock_bh(&dn_rt_flush_lock);
388 }
389
390 /**
391 * dn_return_short - Return a short packet to its sender
392 * @skb: The packet to return
393 *
394 */
395 static int dn_return_short(struct sk_buff *skb)
396 {
397 struct dn_skb_cb *cb;
398 unsigned char *ptr;
399 __le16 *src;
400 __le16 *dst;
401
402 /* Add back headers */
403 skb_push(skb, skb->data - skb_network_header(skb));
404
405 if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
406 return NET_RX_DROP;
407
408 cb = DN_SKB_CB(skb);
409 /* Skip packet length and point to flags */
410 ptr = skb->data + 2;
411 *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
412
413 dst = (__le16 *)ptr;
414 ptr += 2;
415 src = (__le16 *)ptr;
416 ptr += 2;
417 *ptr = 0; /* Zero hop count */
418
419 swap(*src, *dst);
420
421 skb->pkt_type = PACKET_OUTGOING;
422 dn_rt_finish_output(skb, NULL, NULL);
423 return NET_RX_SUCCESS;
424 }
425
426 /**
427 * dn_return_long - Return a long packet to its sender
428 * @skb: The long format packet to return
429 *
430 */
431 static int dn_return_long(struct sk_buff *skb)
432 {
433 struct dn_skb_cb *cb;
434 unsigned char *ptr;
435 unsigned char *src_addr, *dst_addr;
436 unsigned char tmp[ETH_ALEN];
437
438 /* Add back all headers */
439 skb_push(skb, skb->data - skb_network_header(skb));
440
441 if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
442 return NET_RX_DROP;
443
444 cb = DN_SKB_CB(skb);
445 /* Ignore packet length and point to flags */
446 ptr = skb->data + 2;
447
448 /* Skip padding */
449 if (*ptr & DN_RT_F_PF) {
450 char padlen = (*ptr & ~DN_RT_F_PF);
451 ptr += padlen;
452 }
453
454 *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
455 ptr += 2;
456 dst_addr = ptr;
457 ptr += 8;
458 src_addr = ptr;
459 ptr += 6;
460 *ptr = 0; /* Zero hop count */
461
462 /* Swap source and destination */
463 memcpy(tmp, src_addr, ETH_ALEN);
464 memcpy(src_addr, dst_addr, ETH_ALEN);
465 memcpy(dst_addr, tmp, ETH_ALEN);
466
467 skb->pkt_type = PACKET_OUTGOING;
468 dn_rt_finish_output(skb, dst_addr, src_addr);
469 return NET_RX_SUCCESS;
470 }
471
472 /**
473 * dn_route_rx_packet - Try and find a route for an incoming packet
474 * @skb: The packet to find a route for
475 *
476 * Returns: result of input function if route is found, error code otherwise
477 */
478 static int dn_route_rx_packet(struct sk_buff *skb)
479 {
480 struct dn_skb_cb *cb;
481 int err;
482
483 if ((err = dn_route_input(skb)) == 0)
484 return dst_input(skb);
485
486 cb = DN_SKB_CB(skb);
487 if (decnet_debug_level & 4) {
488 char *devname = skb->dev ? skb->dev->name : "???";
489
490 printk(KERN_DEBUG
491 "DECnet: dn_route_rx_packet: rt_flags=0x%02x dev=%s len=%d src=0x%04hx dst=0x%04hx err=%d type=%d\n",
492 (int)cb->rt_flags, devname, skb->len,
493 le16_to_cpu(cb->src), le16_to_cpu(cb->dst),
494 err, skb->pkt_type);
495 }
496
497 if ((skb->pkt_type == PACKET_HOST) && (cb->rt_flags & DN_RT_F_RQR)) {
498 switch(cb->rt_flags & DN_RT_PKT_MSK) {
499 case DN_RT_PKT_SHORT:
500 return dn_return_short(skb);
501 case DN_RT_PKT_LONG:
502 return dn_return_long(skb);
503 }
504 }
505
506 kfree_skb(skb);
507 return NET_RX_DROP;
508 }
509
510 static int dn_route_rx_long(struct sk_buff *skb)
511 {
512 struct dn_skb_cb *cb = DN_SKB_CB(skb);
513 unsigned char *ptr = skb->data;
514
515 if (!pskb_may_pull(skb, 21)) /* 20 for long header, 1 for shortest nsp */
516 goto drop_it;
517
518 skb_pull(skb, 20);
519 skb_reset_transport_header(skb);
520
521 /* Destination info */
522 ptr += 2;
523 cb->dst = dn_eth2dn(ptr);
524 if (memcmp(ptr, dn_hiord_addr, 4) != 0)
525 goto drop_it;
526 ptr += 6;
527
528
529 /* Source info */
530 ptr += 2;
531 cb->src = dn_eth2dn(ptr);
532 if (memcmp(ptr, dn_hiord_addr, 4) != 0)
533 goto drop_it;
534 ptr += 6;
535 /* Other junk */
536 ptr++;
537 cb->hops = *ptr++; /* Visit Count */
538
539 return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING, skb, skb->dev, NULL,
540 dn_route_rx_packet);
541
542 drop_it:
543 kfree_skb(skb);
544 return NET_RX_DROP;
545 }
546
547
548
549 static int dn_route_rx_short(struct sk_buff *skb)
550 {
551 struct dn_skb_cb *cb = DN_SKB_CB(skb);
552 unsigned char *ptr = skb->data;
553
554 if (!pskb_may_pull(skb, 6)) /* 5 for short header + 1 for shortest nsp */
555 goto drop_it;
556
557 skb_pull(skb, 5);
558 skb_reset_transport_header(skb);
559
560 cb->dst = *(__le16 *)ptr;
561 ptr += 2;
562 cb->src = *(__le16 *)ptr;
563 ptr += 2;
564 cb->hops = *ptr & 0x3f;
565
566 return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING, skb, skb->dev, NULL,
567 dn_route_rx_packet);
568
569 drop_it:
570 kfree_skb(skb);
571 return NET_RX_DROP;
572 }
573
574 static int dn_route_discard(struct sk_buff *skb)
575 {
576 /*
577 * I know we drop the packet here, but thats considered success in
578 * this case
579 */
580 kfree_skb(skb);
581 return NET_RX_SUCCESS;
582 }
583
584 static int dn_route_ptp_hello(struct sk_buff *skb)
585 {
586 dn_dev_hello(skb);
587 dn_neigh_pointopoint_hello(skb);
588 return NET_RX_SUCCESS;
589 }
590
591 int dn_route_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
592 {
593 struct dn_skb_cb *cb;
594 unsigned char flags = 0;
595 __u16 len = le16_to_cpu(*(__le16 *)skb->data);
596 struct dn_dev *dn = rcu_dereference(dev->dn_ptr);
597 unsigned char padlen = 0;
598
599 if (!net_eq(dev_net(dev), &init_net))
600 goto dump_it;
601
602 if (dn == NULL)
603 goto dump_it;
604
605 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
606 goto out;
607
608 if (!pskb_may_pull(skb, 3))
609 goto dump_it;
610
611 skb_pull(skb, 2);
612
613 if (len > skb->len)
614 goto dump_it;
615
616 skb_trim(skb, len);
617
618 flags = *skb->data;
619
620 cb = DN_SKB_CB(skb);
621 cb->stamp = jiffies;
622 cb->iif = dev->ifindex;
623
624 /*
625 * If we have padding, remove it.
626 */
627 if (flags & DN_RT_F_PF) {
628 padlen = flags & ~DN_RT_F_PF;
629 if (!pskb_may_pull(skb, padlen + 1))
630 goto dump_it;
631 skb_pull(skb, padlen);
632 flags = *skb->data;
633 }
634
635 skb_reset_network_header(skb);
636
637 /*
638 * Weed out future version DECnet
639 */
640 if (flags & DN_RT_F_VER)
641 goto dump_it;
642
643 cb->rt_flags = flags;
644
645 if (decnet_debug_level & 1)
646 printk(KERN_DEBUG
647 "dn_route_rcv: got 0x%02x from %s [%d %d %d]\n",
648 (int)flags, (dev) ? dev->name : "???", len, skb->len,
649 padlen);
650
651 if (flags & DN_RT_PKT_CNTL) {
652 if (unlikely(skb_linearize(skb)))
653 goto dump_it;
654
655 switch(flags & DN_RT_CNTL_MSK) {
656 case DN_RT_PKT_INIT:
657 dn_dev_init_pkt(skb);
658 break;
659 case DN_RT_PKT_VERI:
660 dn_dev_veri_pkt(skb);
661 break;
662 }
663
664 if (dn->parms.state != DN_DEV_S_RU)
665 goto dump_it;
666
667 switch(flags & DN_RT_CNTL_MSK) {
668 case DN_RT_PKT_HELO:
669 return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
670 skb, skb->dev, NULL,
671 dn_route_ptp_hello);
672
673 case DN_RT_PKT_L1RT:
674 case DN_RT_PKT_L2RT:
675 return NF_HOOK(NFPROTO_DECNET, NF_DN_ROUTE,
676 skb, skb->dev, NULL,
677 dn_route_discard);
678 case DN_RT_PKT_ERTH:
679 return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
680 skb, skb->dev, NULL,
681 dn_neigh_router_hello);
682
683 case DN_RT_PKT_EEDH:
684 return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
685 skb, skb->dev, NULL,
686 dn_neigh_endnode_hello);
687 }
688 } else {
689 if (dn->parms.state != DN_DEV_S_RU)
690 goto dump_it;
691
692 skb_pull(skb, 1); /* Pull flags */
693
694 switch(flags & DN_RT_PKT_MSK) {
695 case DN_RT_PKT_LONG:
696 return dn_route_rx_long(skb);
697 case DN_RT_PKT_SHORT:
698 return dn_route_rx_short(skb);
699 }
700 }
701
702 dump_it:
703 kfree_skb(skb);
704 out:
705 return NET_RX_DROP;
706 }
707
708 static int dn_output(struct sk_buff *skb)
709 {
710 struct dst_entry *dst = skb_dst(skb);
711 struct dn_route *rt = (struct dn_route *)dst;
712 struct net_device *dev = dst->dev;
713 struct dn_skb_cb *cb = DN_SKB_CB(skb);
714 struct neighbour *neigh;
715
716 int err = -EINVAL;
717
718 if ((neigh = dst->neighbour) == NULL)
719 goto error;
720
721 skb->dev = dev;
722
723 cb->src = rt->rt_saddr;
724 cb->dst = rt->rt_daddr;
725
726 /*
727 * Always set the Intra-Ethernet bit on all outgoing packets
728 * originated on this node. Only valid flag from upper layers
729 * is return-to-sender-requested. Set hop count to 0 too.
730 */
731 cb->rt_flags &= ~DN_RT_F_RQR;
732 cb->rt_flags |= DN_RT_F_IE;
733 cb->hops = 0;
734
735 return NF_HOOK(NFPROTO_DECNET, NF_DN_LOCAL_OUT, skb, NULL, dev,
736 neigh->output);
737
738 error:
739 if (net_ratelimit())
740 printk(KERN_DEBUG "dn_output: This should not happen\n");
741
742 kfree_skb(skb);
743
744 return err;
745 }
746
747 static int dn_forward(struct sk_buff *skb)
748 {
749 struct dn_skb_cb *cb = DN_SKB_CB(skb);
750 struct dst_entry *dst = skb_dst(skb);
751 struct dn_dev *dn_db = rcu_dereference(dst->dev->dn_ptr);
752 struct dn_route *rt;
753 struct neighbour *neigh = dst->neighbour;
754 int header_len;
755 #ifdef CONFIG_NETFILTER
756 struct net_device *dev = skb->dev;
757 #endif
758
759 if (skb->pkt_type != PACKET_HOST)
760 goto drop;
761
762 /* Ensure that we have enough space for headers */
763 rt = (struct dn_route *)skb_dst(skb);
764 header_len = dn_db->use_long ? 21 : 6;
765 if (skb_cow(skb, LL_RESERVED_SPACE(rt->dst.dev)+header_len))
766 goto drop;
767
768 /*
769 * Hop count exceeded.
770 */
771 if (++cb->hops > 30)
772 goto drop;
773
774 skb->dev = rt->dst.dev;
775
776 /*
777 * If packet goes out same interface it came in on, then set
778 * the Intra-Ethernet bit. This has no effect for short
779 * packets, so we don't need to test for them here.
780 */
781 cb->rt_flags &= ~DN_RT_F_IE;
782 if (rt->rt_flags & RTCF_DOREDIRECT)
783 cb->rt_flags |= DN_RT_F_IE;
784
785 return NF_HOOK(NFPROTO_DECNET, NF_DN_FORWARD, skb, dev, skb->dev,
786 neigh->output);
787
788 drop:
789 kfree_skb(skb);
790 return NET_RX_DROP;
791 }
792
793 /*
794 * Used to catch bugs. This should never normally get
795 * called.
796 */
797 static int dn_rt_bug(struct sk_buff *skb)
798 {
799 if (net_ratelimit()) {
800 struct dn_skb_cb *cb = DN_SKB_CB(skb);
801
802 printk(KERN_DEBUG "dn_rt_bug: skb from:%04x to:%04x\n",
803 le16_to_cpu(cb->src), le16_to_cpu(cb->dst));
804 }
805
806 kfree_skb(skb);
807
808 return NET_RX_DROP;
809 }
810
811 static unsigned int dn_dst_default_advmss(const struct dst_entry *dst)
812 {
813 return dn_mss_from_pmtu(dst->dev, dst_mtu(dst));
814 }
815
816 static unsigned int dn_dst_default_mtu(const struct dst_entry *dst)
817 {
818 return dst->dev->mtu;
819 }
820
821 static int dn_rt_set_next_hop(struct dn_route *rt, struct dn_fib_res *res)
822 {
823 struct dn_fib_info *fi = res->fi;
824 struct net_device *dev = rt->dst.dev;
825 unsigned int mss_metric;
826 struct neighbour *n;
827
828 if (fi) {
829 if (DN_FIB_RES_GW(*res) &&
830 DN_FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
831 rt->rt_gateway = DN_FIB_RES_GW(*res);
832 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
833 }
834 rt->rt_type = res->type;
835
836 if (dev != NULL && rt->dst.neighbour == NULL) {
837 n = __neigh_lookup_errno(&dn_neigh_table, &rt->rt_gateway, dev);
838 if (IS_ERR(n))
839 return PTR_ERR(n);
840 rt->dst.neighbour = n;
841 }
842
843 if (dst_metric(&rt->dst, RTAX_MTU) > rt->dst.dev->mtu)
844 dst_metric_set(&rt->dst, RTAX_MTU, rt->dst.dev->mtu);
845 mss_metric = dst_metric_raw(&rt->dst, RTAX_ADVMSS);
846 if (mss_metric) {
847 unsigned int mss = dn_mss_from_pmtu(dev, dst_mtu(&rt->dst));
848 if (mss_metric > mss)
849 dst_metric_set(&rt->dst, RTAX_ADVMSS, mss);
850 }
851 return 0;
852 }
853
854 static inline int dn_match_addr(__le16 addr1, __le16 addr2)
855 {
856 __u16 tmp = le16_to_cpu(addr1) ^ le16_to_cpu(addr2);
857 int match = 16;
858 while(tmp) {
859 tmp >>= 1;
860 match--;
861 }
862 return match;
863 }
864
865 static __le16 dnet_select_source(const struct net_device *dev, __le16 daddr, int scope)
866 {
867 __le16 saddr = 0;
868 struct dn_dev *dn_db;
869 struct dn_ifaddr *ifa;
870 int best_match = 0;
871 int ret;
872
873 rcu_read_lock();
874 dn_db = rcu_dereference(dev->dn_ptr);
875 for (ifa = rcu_dereference(dn_db->ifa_list);
876 ifa != NULL;
877 ifa = rcu_dereference(ifa->ifa_next)) {
878 if (ifa->ifa_scope > scope)
879 continue;
880 if (!daddr) {
881 saddr = ifa->ifa_local;
882 break;
883 }
884 ret = dn_match_addr(daddr, ifa->ifa_local);
885 if (ret > best_match)
886 saddr = ifa->ifa_local;
887 if (best_match == 0)
888 saddr = ifa->ifa_local;
889 }
890 rcu_read_unlock();
891
892 return saddr;
893 }
894
895 static inline __le16 __dn_fib_res_prefsrc(struct dn_fib_res *res)
896 {
897 return dnet_select_source(DN_FIB_RES_DEV(*res), DN_FIB_RES_GW(*res), res->scope);
898 }
899
900 static inline __le16 dn_fib_rules_map_destination(__le16 daddr, struct dn_fib_res *res)
901 {
902 __le16 mask = dnet_make_mask(res->prefixlen);
903 return (daddr&~mask)|res->fi->fib_nh->nh_gw;
904 }
905
906 static int dn_route_output_slow(struct dst_entry **pprt, const struct flowidn *oldflp, int try_hard)
907 {
908 struct flowidn fld = {
909 .daddr = oldflp->daddr,
910 .saddr = oldflp->saddr,
911 .flowidn_scope = RT_SCOPE_UNIVERSE,
912 .flowidn_mark = oldflp->flowidn_mark,
913 .flowidn_iif = init_net.loopback_dev->ifindex,
914 .flowidn_oif = oldflp->flowidn_oif,
915 };
916 struct dn_route *rt = NULL;
917 struct net_device *dev_out = NULL, *dev;
918 struct neighbour *neigh = NULL;
919 unsigned hash;
920 unsigned flags = 0;
921 struct dn_fib_res res = { .fi = NULL, .type = RTN_UNICAST };
922 int err;
923 int free_res = 0;
924 __le16 gateway = 0;
925
926 if (decnet_debug_level & 16)
927 printk(KERN_DEBUG
928 "dn_route_output_slow: dst=%04x src=%04x mark=%d"
929 " iif=%d oif=%d\n", le16_to_cpu(oldflp->daddr),
930 le16_to_cpu(oldflp->saddr),
931 oldflp->flowidn_mark, init_net.loopback_dev->ifindex,
932 oldflp->flowidn_oif);
933
934 /* If we have an output interface, verify its a DECnet device */
935 if (oldflp->flowidn_oif) {
936 dev_out = dev_get_by_index(&init_net, oldflp->flowidn_oif);
937 err = -ENODEV;
938 if (dev_out && dev_out->dn_ptr == NULL) {
939 dev_put(dev_out);
940 dev_out = NULL;
941 }
942 if (dev_out == NULL)
943 goto out;
944 }
945
946 /* If we have a source address, verify that its a local address */
947 if (oldflp->saddr) {
948 err = -EADDRNOTAVAIL;
949
950 if (dev_out) {
951 if (dn_dev_islocal(dev_out, oldflp->saddr))
952 goto source_ok;
953 dev_put(dev_out);
954 goto out;
955 }
956 rcu_read_lock();
957 for_each_netdev_rcu(&init_net, dev) {
958 if (!dev->dn_ptr)
959 continue;
960 if (!dn_dev_islocal(dev, oldflp->saddr))
961 continue;
962 if ((dev->flags & IFF_LOOPBACK) &&
963 oldflp->daddr &&
964 !dn_dev_islocal(dev, oldflp->daddr))
965 continue;
966
967 dev_out = dev;
968 break;
969 }
970 rcu_read_unlock();
971 if (dev_out == NULL)
972 goto out;
973 dev_hold(dev_out);
974 source_ok:
975 ;
976 }
977
978 /* No destination? Assume its local */
979 if (!fld.daddr) {
980 fld.daddr = fld.saddr;
981
982 err = -EADDRNOTAVAIL;
983 if (dev_out)
984 dev_put(dev_out);
985 dev_out = init_net.loopback_dev;
986 dev_hold(dev_out);
987 if (!fld.daddr) {
988 fld.daddr =
989 fld.saddr = dnet_select_source(dev_out, 0,
990 RT_SCOPE_HOST);
991 if (!fld.daddr)
992 goto out;
993 }
994 fld.flowidn_oif = init_net.loopback_dev->ifindex;
995 res.type = RTN_LOCAL;
996 goto make_route;
997 }
998
999 if (decnet_debug_level & 16)
1000 printk(KERN_DEBUG
1001 "dn_route_output_slow: initial checks complete."
1002 " dst=%o4x src=%04x oif=%d try_hard=%d\n",
1003 le16_to_cpu(fld.daddr), le16_to_cpu(fld.saddr),
1004 fld.flowidn_oif, try_hard);
1005
1006 /*
1007 * N.B. If the kernel is compiled without router support then
1008 * dn_fib_lookup() will evaluate to non-zero so this if () block
1009 * will always be executed.
1010 */
1011 err = -ESRCH;
1012 if (try_hard || (err = dn_fib_lookup(&fld, &res)) != 0) {
1013 struct dn_dev *dn_db;
1014 if (err != -ESRCH)
1015 goto out;
1016 /*
1017 * Here the fallback is basically the standard algorithm for
1018 * routing in endnodes which is described in the DECnet routing
1019 * docs
1020 *
1021 * If we are not trying hard, look in neighbour cache.
1022 * The result is tested to ensure that if a specific output
1023 * device/source address was requested, then we honour that
1024 * here
1025 */
1026 if (!try_hard) {
1027 neigh = neigh_lookup_nodev(&dn_neigh_table, &init_net, &fld.daddr);
1028 if (neigh) {
1029 if ((oldflp->flowidn_oif &&
1030 (neigh->dev->ifindex != oldflp->flowidn_oif)) ||
1031 (oldflp->saddr &&
1032 (!dn_dev_islocal(neigh->dev,
1033 oldflp->saddr)))) {
1034 neigh_release(neigh);
1035 neigh = NULL;
1036 } else {
1037 if (dev_out)
1038 dev_put(dev_out);
1039 if (dn_dev_islocal(neigh->dev, fld.daddr)) {
1040 dev_out = init_net.loopback_dev;
1041 res.type = RTN_LOCAL;
1042 } else {
1043 dev_out = neigh->dev;
1044 }
1045 dev_hold(dev_out);
1046 goto select_source;
1047 }
1048 }
1049 }
1050
1051 /* Not there? Perhaps its a local address */
1052 if (dev_out == NULL)
1053 dev_out = dn_dev_get_default();
1054 err = -ENODEV;
1055 if (dev_out == NULL)
1056 goto out;
1057 dn_db = rcu_dereference_raw(dev_out->dn_ptr);
1058 /* Possible improvement - check all devices for local addr */
1059 if (dn_dev_islocal(dev_out, fld.daddr)) {
1060 dev_put(dev_out);
1061 dev_out = init_net.loopback_dev;
1062 dev_hold(dev_out);
1063 res.type = RTN_LOCAL;
1064 goto select_source;
1065 }
1066 /* Not local either.... try sending it to the default router */
1067 neigh = neigh_clone(dn_db->router);
1068 BUG_ON(neigh && neigh->dev != dev_out);
1069
1070 /* Ok then, we assume its directly connected and move on */
1071 select_source:
1072 if (neigh)
1073 gateway = ((struct dn_neigh *)neigh)->addr;
1074 if (gateway == 0)
1075 gateway = fld.daddr;
1076 if (fld.saddr == 0) {
1077 fld.saddr = dnet_select_source(dev_out, gateway,
1078 res.type == RTN_LOCAL ?
1079 RT_SCOPE_HOST :
1080 RT_SCOPE_LINK);
1081 if (fld.saddr == 0 && res.type != RTN_LOCAL)
1082 goto e_addr;
1083 }
1084 fld.flowidn_oif = dev_out->ifindex;
1085 goto make_route;
1086 }
1087 free_res = 1;
1088
1089 if (res.type == RTN_NAT)
1090 goto e_inval;
1091
1092 if (res.type == RTN_LOCAL) {
1093 if (!fld.saddr)
1094 fld.saddr = fld.daddr;
1095 if (dev_out)
1096 dev_put(dev_out);
1097 dev_out = init_net.loopback_dev;
1098 dev_hold(dev_out);
1099 fld.flowidn_oif = dev_out->ifindex;
1100 if (res.fi)
1101 dn_fib_info_put(res.fi);
1102 res.fi = NULL;
1103 goto make_route;
1104 }
1105
1106 if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1107 dn_fib_select_multipath(&fld, &res);
1108
1109 /*
1110 * We could add some logic to deal with default routes here and
1111 * get rid of some of the special casing above.
1112 */
1113
1114 if (!fld.saddr)
1115 fld.saddr = DN_FIB_RES_PREFSRC(res);
1116
1117 if (dev_out)
1118 dev_put(dev_out);
1119 dev_out = DN_FIB_RES_DEV(res);
1120 dev_hold(dev_out);
1121 fld.flowidn_oif = dev_out->ifindex;
1122 gateway = DN_FIB_RES_GW(res);
1123
1124 make_route:
1125 if (dev_out->flags & IFF_LOOPBACK)
1126 flags |= RTCF_LOCAL;
1127
1128 rt = dst_alloc(&dn_dst_ops, 0);
1129 if (rt == NULL)
1130 goto e_nobufs;
1131
1132 atomic_set(&rt->dst.__refcnt, 1);
1133 rt->dst.flags = DST_HOST;
1134
1135 rt->fld.saddr = oldflp->saddr;
1136 rt->fld.daddr = oldflp->daddr;
1137 rt->fld.flowidn_oif = oldflp->flowidn_oif;
1138 rt->fld.flowidn_iif = 0;
1139 rt->fld.flowidn_mark = oldflp->flowidn_mark;
1140
1141 rt->rt_saddr = fld.saddr;
1142 rt->rt_daddr = fld.daddr;
1143 rt->rt_gateway = gateway ? gateway : fld.daddr;
1144 rt->rt_local_src = fld.saddr;
1145
1146 rt->rt_dst_map = fld.daddr;
1147 rt->rt_src_map = fld.saddr;
1148
1149 rt->dst.dev = dev_out;
1150 dev_hold(dev_out);
1151 rt->dst.neighbour = neigh;
1152 neigh = NULL;
1153
1154 rt->dst.lastuse = jiffies;
1155 rt->dst.output = dn_output;
1156 rt->dst.input = dn_rt_bug;
1157 rt->rt_flags = flags;
1158 if (flags & RTCF_LOCAL)
1159 rt->dst.input = dn_nsp_rx;
1160
1161 err = dn_rt_set_next_hop(rt, &res);
1162 if (err)
1163 goto e_neighbour;
1164
1165 hash = dn_hash(rt->fld.saddr, rt->fld.daddr);
1166 dn_insert_route(rt, hash, (struct dn_route **)pprt);
1167
1168 done:
1169 if (neigh)
1170 neigh_release(neigh);
1171 if (free_res)
1172 dn_fib_res_put(&res);
1173 if (dev_out)
1174 dev_put(dev_out);
1175 out:
1176 return err;
1177
1178 e_addr:
1179 err = -EADDRNOTAVAIL;
1180 goto done;
1181 e_inval:
1182 err = -EINVAL;
1183 goto done;
1184 e_nobufs:
1185 err = -ENOBUFS;
1186 goto done;
1187 e_neighbour:
1188 dst_free(&rt->dst);
1189 goto e_nobufs;
1190 }
1191
1192
1193 /*
1194 * N.B. The flags may be moved into the flowi at some future stage.
1195 */
1196 static int __dn_route_output_key(struct dst_entry **pprt, const struct flowidn *flp, int flags)
1197 {
1198 unsigned hash = dn_hash(flp->saddr, flp->daddr);
1199 struct dn_route *rt = NULL;
1200
1201 if (!(flags & MSG_TRYHARD)) {
1202 rcu_read_lock_bh();
1203 for (rt = rcu_dereference_bh(dn_rt_hash_table[hash].chain); rt;
1204 rt = rcu_dereference_bh(rt->dst.dn_next)) {
1205 if ((flp->daddr == rt->fld.daddr) &&
1206 (flp->saddr == rt->fld.saddr) &&
1207 (flp->flowidn_mark == rt->fld.flowidn_mark) &&
1208 dn_is_output_route(rt) &&
1209 (rt->fld.flowidn_oif == flp->flowidn_oif)) {
1210 dst_use(&rt->dst, jiffies);
1211 rcu_read_unlock_bh();
1212 *pprt = &rt->dst;
1213 return 0;
1214 }
1215 }
1216 rcu_read_unlock_bh();
1217 }
1218
1219 return dn_route_output_slow(pprt, flp, flags);
1220 }
1221
1222 static int dn_route_output_key(struct dst_entry **pprt, struct flowidn *flp, int flags)
1223 {
1224 int err;
1225
1226 err = __dn_route_output_key(pprt, flp, flags);
1227 if (err == 0 && flp->flowidn_proto) {
1228 *pprt = xfrm_lookup(&init_net, *pprt,
1229 flowidn_to_flowi(flp), NULL, 0);
1230 if (IS_ERR(*pprt)) {
1231 err = PTR_ERR(*pprt);
1232 *pprt = NULL;
1233 }
1234 }
1235 return err;
1236 }
1237
1238 int dn_route_output_sock(struct dst_entry **pprt, struct flowidn *fl, struct sock *sk, int flags)
1239 {
1240 int err;
1241
1242 err = __dn_route_output_key(pprt, fl, flags & MSG_TRYHARD);
1243 if (err == 0 && fl->flowidn_proto) {
1244 if (!(flags & MSG_DONTWAIT))
1245 fl->flowidn_flags |= FLOWI_FLAG_CAN_SLEEP;
1246 *pprt = xfrm_lookup(&init_net, *pprt,
1247 flowidn_to_flowi(fl), sk, 0);
1248 if (IS_ERR(*pprt)) {
1249 err = PTR_ERR(*pprt);
1250 *pprt = NULL;
1251 }
1252 }
1253 return err;
1254 }
1255
1256 static int dn_route_input_slow(struct sk_buff *skb)
1257 {
1258 struct dn_route *rt = NULL;
1259 struct dn_skb_cb *cb = DN_SKB_CB(skb);
1260 struct net_device *in_dev = skb->dev;
1261 struct net_device *out_dev = NULL;
1262 struct dn_dev *dn_db;
1263 struct neighbour *neigh = NULL;
1264 unsigned hash;
1265 int flags = 0;
1266 __le16 gateway = 0;
1267 __le16 local_src = 0;
1268 struct flowidn fld = {
1269 .daddr = cb->dst,
1270 .saddr = cb->src,
1271 .flowidn_scope = RT_SCOPE_UNIVERSE,
1272 .flowidn_mark = skb->mark,
1273 .flowidn_iif = skb->dev->ifindex,
1274 };
1275 struct dn_fib_res res = { .fi = NULL, .type = RTN_UNREACHABLE };
1276 int err = -EINVAL;
1277 int free_res = 0;
1278
1279 dev_hold(in_dev);
1280
1281 if ((dn_db = rcu_dereference(in_dev->dn_ptr)) == NULL)
1282 goto out;
1283
1284 /* Zero source addresses are not allowed */
1285 if (fld.saddr == 0)
1286 goto out;
1287
1288 /*
1289 * In this case we've just received a packet from a source
1290 * outside ourselves pretending to come from us. We don't
1291 * allow it any further to prevent routing loops, spoofing and
1292 * other nasties. Loopback packets already have the dst attached
1293 * so this only affects packets which have originated elsewhere.
1294 */
1295 err = -ENOTUNIQ;
1296 if (dn_dev_islocal(in_dev, cb->src))
1297 goto out;
1298
1299 err = dn_fib_lookup(&fld, &res);
1300 if (err) {
1301 if (err != -ESRCH)
1302 goto out;
1303 /*
1304 * Is the destination us ?
1305 */
1306 if (!dn_dev_islocal(in_dev, cb->dst))
1307 goto e_inval;
1308
1309 res.type = RTN_LOCAL;
1310 } else {
1311 __le16 src_map = fld.saddr;
1312 free_res = 1;
1313
1314 out_dev = DN_FIB_RES_DEV(res);
1315 if (out_dev == NULL) {
1316 if (net_ratelimit())
1317 printk(KERN_CRIT "Bug in dn_route_input_slow() "
1318 "No output device\n");
1319 goto e_inval;
1320 }
1321 dev_hold(out_dev);
1322
1323 if (res.r)
1324 src_map = fld.saddr; /* no NAT support for now */
1325
1326 gateway = DN_FIB_RES_GW(res);
1327 if (res.type == RTN_NAT) {
1328 fld.daddr = dn_fib_rules_map_destination(fld.daddr, &res);
1329 dn_fib_res_put(&res);
1330 free_res = 0;
1331 if (dn_fib_lookup(&fld, &res))
1332 goto e_inval;
1333 free_res = 1;
1334 if (res.type != RTN_UNICAST)
1335 goto e_inval;
1336 flags |= RTCF_DNAT;
1337 gateway = fld.daddr;
1338 }
1339 fld.saddr = src_map;
1340 }
1341
1342 switch(res.type) {
1343 case RTN_UNICAST:
1344 /*
1345 * Forwarding check here, we only check for forwarding
1346 * being turned off, if you want to only forward intra
1347 * area, its up to you to set the routing tables up
1348 * correctly.
1349 */
1350 if (dn_db->parms.forwarding == 0)
1351 goto e_inval;
1352
1353 if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1354 dn_fib_select_multipath(&fld, &res);
1355
1356 /*
1357 * Check for out_dev == in_dev. We use the RTCF_DOREDIRECT
1358 * flag as a hint to set the intra-ethernet bit when
1359 * forwarding. If we've got NAT in operation, we don't do
1360 * this optimisation.
1361 */
1362 if (out_dev == in_dev && !(flags & RTCF_NAT))
1363 flags |= RTCF_DOREDIRECT;
1364
1365 local_src = DN_FIB_RES_PREFSRC(res);
1366
1367 case RTN_BLACKHOLE:
1368 case RTN_UNREACHABLE:
1369 break;
1370 case RTN_LOCAL:
1371 flags |= RTCF_LOCAL;
1372 fld.saddr = cb->dst;
1373 fld.daddr = cb->src;
1374
1375 /* Routing tables gave us a gateway */
1376 if (gateway)
1377 goto make_route;
1378
1379 /* Packet was intra-ethernet, so we know its on-link */
1380 if (cb->rt_flags & DN_RT_F_IE) {
1381 gateway = cb->src;
1382 flags |= RTCF_DIRECTSRC;
1383 goto make_route;
1384 }
1385
1386 /* Use the default router if there is one */
1387 neigh = neigh_clone(dn_db->router);
1388 if (neigh) {
1389 gateway = ((struct dn_neigh *)neigh)->addr;
1390 goto make_route;
1391 }
1392
1393 /* Close eyes and pray */
1394 gateway = cb->src;
1395 flags |= RTCF_DIRECTSRC;
1396 goto make_route;
1397 default:
1398 goto e_inval;
1399 }
1400
1401 make_route:
1402 rt = dst_alloc(&dn_dst_ops, 0);
1403 if (rt == NULL)
1404 goto e_nobufs;
1405
1406 rt->rt_saddr = fld.saddr;
1407 rt->rt_daddr = fld.daddr;
1408 rt->rt_gateway = fld.daddr;
1409 if (gateway)
1410 rt->rt_gateway = gateway;
1411 rt->rt_local_src = local_src ? local_src : rt->rt_saddr;
1412
1413 rt->rt_dst_map = fld.daddr;
1414 rt->rt_src_map = fld.saddr;
1415
1416 rt->fld.saddr = cb->src;
1417 rt->fld.daddr = cb->dst;
1418 rt->fld.flowidn_oif = 0;
1419 rt->fld.flowidn_iif = in_dev->ifindex;
1420 rt->fld.flowidn_mark = fld.flowidn_mark;
1421
1422 rt->dst.flags = DST_HOST;
1423 rt->dst.neighbour = neigh;
1424 rt->dst.dev = out_dev;
1425 rt->dst.lastuse = jiffies;
1426 rt->dst.output = dn_rt_bug;
1427 switch(res.type) {
1428 case RTN_UNICAST:
1429 rt->dst.input = dn_forward;
1430 break;
1431 case RTN_LOCAL:
1432 rt->dst.output = dn_output;
1433 rt->dst.input = dn_nsp_rx;
1434 rt->dst.dev = in_dev;
1435 flags |= RTCF_LOCAL;
1436 break;
1437 default:
1438 case RTN_UNREACHABLE:
1439 case RTN_BLACKHOLE:
1440 rt->dst.input = dst_discard;
1441 }
1442 rt->rt_flags = flags;
1443 if (rt->dst.dev)
1444 dev_hold(rt->dst.dev);
1445
1446 err = dn_rt_set_next_hop(rt, &res);
1447 if (err)
1448 goto e_neighbour;
1449
1450 hash = dn_hash(rt->fld.saddr, rt->fld.daddr);
1451 dn_insert_route(rt, hash, &rt);
1452 skb_dst_set(skb, &rt->dst);
1453
1454 done:
1455 if (neigh)
1456 neigh_release(neigh);
1457 if (free_res)
1458 dn_fib_res_put(&res);
1459 dev_put(in_dev);
1460 if (out_dev)
1461 dev_put(out_dev);
1462 out:
1463 return err;
1464
1465 e_inval:
1466 err = -EINVAL;
1467 goto done;
1468
1469 e_nobufs:
1470 err = -ENOBUFS;
1471 goto done;
1472
1473 e_neighbour:
1474 dst_free(&rt->dst);
1475 goto done;
1476 }
1477
1478 static int dn_route_input(struct sk_buff *skb)
1479 {
1480 struct dn_route *rt;
1481 struct dn_skb_cb *cb = DN_SKB_CB(skb);
1482 unsigned hash = dn_hash(cb->src, cb->dst);
1483
1484 if (skb_dst(skb))
1485 return 0;
1486
1487 rcu_read_lock();
1488 for(rt = rcu_dereference(dn_rt_hash_table[hash].chain); rt != NULL;
1489 rt = rcu_dereference(rt->dst.dn_next)) {
1490 if ((rt->fld.saddr == cb->src) &&
1491 (rt->fld.daddr == cb->dst) &&
1492 (rt->fld.flowidn_oif == 0) &&
1493 (rt->fld.flowidn_mark == skb->mark) &&
1494 (rt->fld.flowidn_iif == cb->iif)) {
1495 dst_use(&rt->dst, jiffies);
1496 rcu_read_unlock();
1497 skb_dst_set(skb, (struct dst_entry *)rt);
1498 return 0;
1499 }
1500 }
1501 rcu_read_unlock();
1502
1503 return dn_route_input_slow(skb);
1504 }
1505
1506 static int dn_rt_fill_info(struct sk_buff *skb, u32 pid, u32 seq,
1507 int event, int nowait, unsigned int flags)
1508 {
1509 struct dn_route *rt = (struct dn_route *)skb_dst(skb);
1510 struct rtmsg *r;
1511 struct nlmsghdr *nlh;
1512 unsigned char *b = skb_tail_pointer(skb);
1513 long expires;
1514
1515 nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*r), flags);
1516 r = NLMSG_DATA(nlh);
1517 r->rtm_family = AF_DECnet;
1518 r->rtm_dst_len = 16;
1519 r->rtm_src_len = 0;
1520 r->rtm_tos = 0;
1521 r->rtm_table = RT_TABLE_MAIN;
1522 RTA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
1523 r->rtm_type = rt->rt_type;
1524 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
1525 r->rtm_scope = RT_SCOPE_UNIVERSE;
1526 r->rtm_protocol = RTPROT_UNSPEC;
1527 if (rt->rt_flags & RTCF_NOTIFY)
1528 r->rtm_flags |= RTM_F_NOTIFY;
1529 RTA_PUT(skb, RTA_DST, 2, &rt->rt_daddr);
1530 if (rt->fld.saddr) {
1531 r->rtm_src_len = 16;
1532 RTA_PUT(skb, RTA_SRC, 2, &rt->fld.saddr);
1533 }
1534 if (rt->dst.dev)
1535 RTA_PUT(skb, RTA_OIF, sizeof(int), &rt->dst.dev->ifindex);
1536 /*
1537 * Note to self - change this if input routes reverse direction when
1538 * they deal only with inputs and not with replies like they do
1539 * currently.
1540 */
1541 RTA_PUT(skb, RTA_PREFSRC, 2, &rt->rt_local_src);
1542 if (rt->rt_daddr != rt->rt_gateway)
1543 RTA_PUT(skb, RTA_GATEWAY, 2, &rt->rt_gateway);
1544 if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
1545 goto rtattr_failure;
1546 expires = rt->dst.expires ? rt->dst.expires - jiffies : 0;
1547 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, 0, 0, expires,
1548 rt->dst.error) < 0)
1549 goto rtattr_failure;
1550 if (dn_is_input_route(rt))
1551 RTA_PUT(skb, RTA_IIF, sizeof(int), &rt->fld.flowidn_iif);
1552
1553 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1554 return skb->len;
1555
1556 nlmsg_failure:
1557 rtattr_failure:
1558 nlmsg_trim(skb, b);
1559 return -1;
1560 }
1561
1562 /*
1563 * This is called by both endnodes and routers now.
1564 */
1565 static int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, void *arg)
1566 {
1567 struct net *net = sock_net(in_skb->sk);
1568 struct rtattr **rta = arg;
1569 struct rtmsg *rtm = NLMSG_DATA(nlh);
1570 struct dn_route *rt = NULL;
1571 struct dn_skb_cb *cb;
1572 int err;
1573 struct sk_buff *skb;
1574 struct flowidn fld;
1575
1576 if (!net_eq(net, &init_net))
1577 return -EINVAL;
1578
1579 memset(&fld, 0, sizeof(fld));
1580 fld.flowidn_proto = DNPROTO_NSP;
1581
1582 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1583 if (skb == NULL)
1584 return -ENOBUFS;
1585 skb_reset_mac_header(skb);
1586 cb = DN_SKB_CB(skb);
1587
1588 if (rta[RTA_SRC-1])
1589 memcpy(&fld.saddr, RTA_DATA(rta[RTA_SRC-1]), 2);
1590 if (rta[RTA_DST-1])
1591 memcpy(&fld.daddr, RTA_DATA(rta[RTA_DST-1]), 2);
1592 if (rta[RTA_IIF-1])
1593 memcpy(&fld.flowidn_iif, RTA_DATA(rta[RTA_IIF-1]), sizeof(int));
1594
1595 if (fld.flowidn_iif) {
1596 struct net_device *dev;
1597 if ((dev = dev_get_by_index(&init_net, fld.flowidn_iif)) == NULL) {
1598 kfree_skb(skb);
1599 return -ENODEV;
1600 }
1601 if (!dev->dn_ptr) {
1602 dev_put(dev);
1603 kfree_skb(skb);
1604 return -ENODEV;
1605 }
1606 skb->protocol = htons(ETH_P_DNA_RT);
1607 skb->dev = dev;
1608 cb->src = fld.saddr;
1609 cb->dst = fld.daddr;
1610 local_bh_disable();
1611 err = dn_route_input(skb);
1612 local_bh_enable();
1613 memset(cb, 0, sizeof(struct dn_skb_cb));
1614 rt = (struct dn_route *)skb_dst(skb);
1615 if (!err && -rt->dst.error)
1616 err = rt->dst.error;
1617 } else {
1618 int oif = 0;
1619 if (rta[RTA_OIF - 1])
1620 memcpy(&oif, RTA_DATA(rta[RTA_OIF - 1]), sizeof(int));
1621 fld.flowidn_oif = oif;
1622 err = dn_route_output_key((struct dst_entry **)&rt, &fld, 0);
1623 }
1624
1625 if (skb->dev)
1626 dev_put(skb->dev);
1627 skb->dev = NULL;
1628 if (err)
1629 goto out_free;
1630 skb_dst_set(skb, &rt->dst);
1631 if (rtm->rtm_flags & RTM_F_NOTIFY)
1632 rt->rt_flags |= RTCF_NOTIFY;
1633
1634 err = dn_rt_fill_info(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, RTM_NEWROUTE, 0, 0);
1635
1636 if (err == 0)
1637 goto out_free;
1638 if (err < 0) {
1639 err = -EMSGSIZE;
1640 goto out_free;
1641 }
1642
1643 return rtnl_unicast(skb, &init_net, NETLINK_CB(in_skb).pid);
1644
1645 out_free:
1646 kfree_skb(skb);
1647 return err;
1648 }
1649
1650 /*
1651 * For routers, this is called from dn_fib_dump, but for endnodes its
1652 * called directly from the rtnetlink dispatch table.
1653 */
1654 int dn_cache_dump(struct sk_buff *skb, struct netlink_callback *cb)
1655 {
1656 struct net *net = sock_net(skb->sk);
1657 struct dn_route *rt;
1658 int h, s_h;
1659 int idx, s_idx;
1660
1661 if (!net_eq(net, &init_net))
1662 return 0;
1663
1664 if (NLMSG_PAYLOAD(cb->nlh, 0) < sizeof(struct rtmsg))
1665 return -EINVAL;
1666 if (!(((struct rtmsg *)NLMSG_DATA(cb->nlh))->rtm_flags&RTM_F_CLONED))
1667 return 0;
1668
1669 s_h = cb->args[0];
1670 s_idx = idx = cb->args[1];
1671 for(h = 0; h <= dn_rt_hash_mask; h++) {
1672 if (h < s_h)
1673 continue;
1674 if (h > s_h)
1675 s_idx = 0;
1676 rcu_read_lock_bh();
1677 for(rt = rcu_dereference_bh(dn_rt_hash_table[h].chain), idx = 0;
1678 rt;
1679 rt = rcu_dereference_bh(rt->dst.dn_next), idx++) {
1680 if (idx < s_idx)
1681 continue;
1682 skb_dst_set(skb, dst_clone(&rt->dst));
1683 if (dn_rt_fill_info(skb, NETLINK_CB(cb->skb).pid,
1684 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
1685 1, NLM_F_MULTI) <= 0) {
1686 skb_dst_drop(skb);
1687 rcu_read_unlock_bh();
1688 goto done;
1689 }
1690 skb_dst_drop(skb);
1691 }
1692 rcu_read_unlock_bh();
1693 }
1694
1695 done:
1696 cb->args[0] = h;
1697 cb->args[1] = idx;
1698 return skb->len;
1699 }
1700
1701 #ifdef CONFIG_PROC_FS
1702 struct dn_rt_cache_iter_state {
1703 int bucket;
1704 };
1705
1706 static struct dn_route *dn_rt_cache_get_first(struct seq_file *seq)
1707 {
1708 struct dn_route *rt = NULL;
1709 struct dn_rt_cache_iter_state *s = seq->private;
1710
1711 for(s->bucket = dn_rt_hash_mask; s->bucket >= 0; --s->bucket) {
1712 rcu_read_lock_bh();
1713 rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1714 if (rt)
1715 break;
1716 rcu_read_unlock_bh();
1717 }
1718 return rt;
1719 }
1720
1721 static struct dn_route *dn_rt_cache_get_next(struct seq_file *seq, struct dn_route *rt)
1722 {
1723 struct dn_rt_cache_iter_state *s = seq->private;
1724
1725 rt = rcu_dereference_bh(rt->dst.dn_next);
1726 while (!rt) {
1727 rcu_read_unlock_bh();
1728 if (--s->bucket < 0)
1729 break;
1730 rcu_read_lock_bh();
1731 rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1732 }
1733 return rt;
1734 }
1735
1736 static void *dn_rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
1737 {
1738 struct dn_route *rt = dn_rt_cache_get_first(seq);
1739
1740 if (rt) {
1741 while(*pos && (rt = dn_rt_cache_get_next(seq, rt)))
1742 --*pos;
1743 }
1744 return *pos ? NULL : rt;
1745 }
1746
1747 static void *dn_rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1748 {
1749 struct dn_route *rt = dn_rt_cache_get_next(seq, v);
1750 ++*pos;
1751 return rt;
1752 }
1753
1754 static void dn_rt_cache_seq_stop(struct seq_file *seq, void *v)
1755 {
1756 if (v)
1757 rcu_read_unlock_bh();
1758 }
1759
1760 static int dn_rt_cache_seq_show(struct seq_file *seq, void *v)
1761 {
1762 struct dn_route *rt = v;
1763 char buf1[DN_ASCBUF_LEN], buf2[DN_ASCBUF_LEN];
1764
1765 seq_printf(seq, "%-8s %-7s %-7s %04d %04d %04d\n",
1766 rt->dst.dev ? rt->dst.dev->name : "*",
1767 dn_addr2asc(le16_to_cpu(rt->rt_daddr), buf1),
1768 dn_addr2asc(le16_to_cpu(rt->rt_saddr), buf2),
1769 atomic_read(&rt->dst.__refcnt),
1770 rt->dst.__use,
1771 (int) dst_metric(&rt->dst, RTAX_RTT));
1772 return 0;
1773 }
1774
1775 static const struct seq_operations dn_rt_cache_seq_ops = {
1776 .start = dn_rt_cache_seq_start,
1777 .next = dn_rt_cache_seq_next,
1778 .stop = dn_rt_cache_seq_stop,
1779 .show = dn_rt_cache_seq_show,
1780 };
1781
1782 static int dn_rt_cache_seq_open(struct inode *inode, struct file *file)
1783 {
1784 return seq_open_private(file, &dn_rt_cache_seq_ops,
1785 sizeof(struct dn_rt_cache_iter_state));
1786 }
1787
1788 static const struct file_operations dn_rt_cache_seq_fops = {
1789 .owner = THIS_MODULE,
1790 .open = dn_rt_cache_seq_open,
1791 .read = seq_read,
1792 .llseek = seq_lseek,
1793 .release = seq_release_private,
1794 };
1795
1796 #endif /* CONFIG_PROC_FS */
1797
1798 void __init dn_route_init(void)
1799 {
1800 int i, goal, order;
1801
1802 dn_dst_ops.kmem_cachep =
1803 kmem_cache_create("dn_dst_cache", sizeof(struct dn_route), 0,
1804 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
1805 dst_entries_init(&dn_dst_ops);
1806 setup_timer(&dn_route_timer, dn_dst_check_expire, 0);
1807 dn_route_timer.expires = jiffies + decnet_dst_gc_interval * HZ;
1808 add_timer(&dn_route_timer);
1809
1810 goal = totalram_pages >> (26 - PAGE_SHIFT);
1811
1812 for(order = 0; (1UL << order) < goal; order++)
1813 /* NOTHING */;
1814
1815 /*
1816 * Only want 1024 entries max, since the table is very, very unlikely
1817 * to be larger than that.
1818 */
1819 while(order && ((((1UL << order) * PAGE_SIZE) /
1820 sizeof(struct dn_rt_hash_bucket)) >= 2048))
1821 order--;
1822
1823 do {
1824 dn_rt_hash_mask = (1UL << order) * PAGE_SIZE /
1825 sizeof(struct dn_rt_hash_bucket);
1826 while(dn_rt_hash_mask & (dn_rt_hash_mask - 1))
1827 dn_rt_hash_mask--;
1828 dn_rt_hash_table = (struct dn_rt_hash_bucket *)
1829 __get_free_pages(GFP_ATOMIC, order);
1830 } while (dn_rt_hash_table == NULL && --order > 0);
1831
1832 if (!dn_rt_hash_table)
1833 panic("Failed to allocate DECnet route cache hash table\n");
1834
1835 printk(KERN_INFO
1836 "DECnet: Routing cache hash table of %u buckets, %ldKbytes\n",
1837 dn_rt_hash_mask,
1838 (long)(dn_rt_hash_mask*sizeof(struct dn_rt_hash_bucket))/1024);
1839
1840 dn_rt_hash_mask--;
1841 for(i = 0; i <= dn_rt_hash_mask; i++) {
1842 spin_lock_init(&dn_rt_hash_table[i].lock);
1843 dn_rt_hash_table[i].chain = NULL;
1844 }
1845
1846 dn_dst_ops.gc_thresh = (dn_rt_hash_mask + 1);
1847
1848 proc_net_fops_create(&init_net, "decnet_cache", S_IRUGO, &dn_rt_cache_seq_fops);
1849
1850 #ifdef CONFIG_DECNET_ROUTER
1851 rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute, dn_fib_dump);
1852 #else
1853 rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute,
1854 dn_cache_dump);
1855 #endif
1856 }
1857
1858 void __exit dn_route_cleanup(void)
1859 {
1860 del_timer(&dn_route_timer);
1861 dn_run_flush(0);
1862
1863 proc_net_remove(&init_net, "decnet_cache");
1864 dst_entries_destroy(&dn_dst_ops);
1865 }
1866
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree