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Merge git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6
[deliverable/linux.git] / net / decnet / dn_route.c
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 <net/sock.h>
70 #include <linux/mm.h>
71 #include <linux/proc_fs.h>
72 #include <linux/seq_file.h>
73 #include <linux/init.h>
74 #include <linux/rtnetlink.h>
75 #include <linux/string.h>
76 #include <linux/netfilter_decnet.h>
77 #include <linux/rcupdate.h>
78 #include <linux/times.h>
79 #include <asm/errno.h>
80 #include <net/neighbour.h>
81 #include <net/dst.h>
82 #include <net/flow.h>
83 #include <net/dn.h>
84 #include <net/dn_dev.h>
85 #include <net/dn_nsp.h>
86 #include <net/dn_route.h>
87 #include <net/dn_neigh.h>
88 #include <net/dn_fib.h>
89
90 struct dn_rt_hash_bucket
91 {
92 struct dn_route *chain;
93 spinlock_t lock;
94 } __attribute__((__aligned__(8)));
95
96 extern struct neigh_table dn_neigh_table;
97
98
99 static unsigned char dn_hiord_addr[6] = {0xAA,0x00,0x04,0x00,0x00,0x00};
100
101 static const int dn_rt_min_delay = 2 * HZ;
102 static const int dn_rt_max_delay = 10 * HZ;
103 static const int dn_rt_mtu_expires = 10 * 60 * HZ;
104
105 static unsigned long dn_rt_deadline;
106
107 static int dn_dst_gc(void);
108 static struct dst_entry *dn_dst_check(struct dst_entry *, __u32);
109 static struct dst_entry *dn_dst_negative_advice(struct dst_entry *);
110 static void dn_dst_link_failure(struct sk_buff *);
111 static void dn_dst_update_pmtu(struct dst_entry *dst, u32 mtu);
112 static int dn_route_input(struct sk_buff *);
113 static void dn_run_flush(unsigned long dummy);
114
115 static struct dn_rt_hash_bucket *dn_rt_hash_table;
116 static unsigned dn_rt_hash_mask;
117
118 static struct timer_list dn_route_timer;
119 static DEFINE_TIMER(dn_rt_flush_timer, dn_run_flush, 0, 0);
120 int decnet_dst_gc_interval = 2;
121
122 static struct dst_ops dn_dst_ops = {
123 .family = PF_DECnet,
124 .protocol = __constant_htons(ETH_P_DNA_RT),
125 .gc_thresh = 128,
126 .gc = dn_dst_gc,
127 .check = dn_dst_check,
128 .negative_advice = dn_dst_negative_advice,
129 .link_failure = dn_dst_link_failure,
130 .update_pmtu = dn_dst_update_pmtu,
131 .entry_size = sizeof(struct dn_route),
132 .entries = ATOMIC_INIT(0),
133 };
134
135 static __inline__ unsigned dn_hash(__le16 src, __le16 dst)
136 {
137 __u16 tmp = (__u16 __force)(src ^ dst);
138 tmp ^= (tmp >> 3);
139 tmp ^= (tmp >> 5);
140 tmp ^= (tmp >> 10);
141 return dn_rt_hash_mask & (unsigned)tmp;
142 }
143
144 static inline void dnrt_free(struct dn_route *rt)
145 {
146 call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free);
147 }
148
149 static inline void dnrt_drop(struct dn_route *rt)
150 {
151 dst_release(&rt->u.dst);
152 call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free);
153 }
154
155 static void dn_dst_check_expire(unsigned long dummy)
156 {
157 int i;
158 struct dn_route *rt, **rtp;
159 unsigned long now = jiffies;
160 unsigned long expire = 120 * HZ;
161
162 for(i = 0; i <= dn_rt_hash_mask; i++) {
163 rtp = &dn_rt_hash_table[i].chain;
164
165 spin_lock(&dn_rt_hash_table[i].lock);
166 while((rt=*rtp) != NULL) {
167 if (atomic_read(&rt->u.dst.__refcnt) ||
168 (now - rt->u.dst.lastuse) < expire) {
169 rtp = &rt->u.rt_next;
170 continue;
171 }
172 *rtp = rt->u.rt_next;
173 rt->u.rt_next = NULL;
174 dnrt_free(rt);
175 }
176 spin_unlock(&dn_rt_hash_table[i].lock);
177
178 if ((jiffies - now) > 0)
179 break;
180 }
181
182 mod_timer(&dn_route_timer, now + decnet_dst_gc_interval * HZ);
183 }
184
185 static int dn_dst_gc(void)
186 {
187 struct dn_route *rt, **rtp;
188 int i;
189 unsigned long now = jiffies;
190 unsigned long expire = 10 * HZ;
191
192 for(i = 0; i <= dn_rt_hash_mask; i++) {
193
194 spin_lock_bh(&dn_rt_hash_table[i].lock);
195 rtp = &dn_rt_hash_table[i].chain;
196
197 while((rt=*rtp) != NULL) {
198 if (atomic_read(&rt->u.dst.__refcnt) ||
199 (now - rt->u.dst.lastuse) < expire) {
200 rtp = &rt->u.rt_next;
201 continue;
202 }
203 *rtp = rt->u.rt_next;
204 rt->u.rt_next = NULL;
205 dnrt_drop(rt);
206 break;
207 }
208 spin_unlock_bh(&dn_rt_hash_table[i].lock);
209 }
210
211 return 0;
212 }
213
214 /*
215 * The decnet standards don't impose a particular minimum mtu, what they
216 * do insist on is that the routing layer accepts a datagram of at least
217 * 230 bytes long. Here we have to subtract the routing header length from
218 * 230 to get the minimum acceptable mtu. If there is no neighbour, then we
219 * assume the worst and use a long header size.
220 *
221 * We update both the mtu and the advertised mss (i.e. the segment size we
222 * advertise to the other end).
223 */
224 static void dn_dst_update_pmtu(struct dst_entry *dst, u32 mtu)
225 {
226 u32 min_mtu = 230;
227 struct dn_dev *dn = dst->neighbour ?
228 (struct dn_dev *)dst->neighbour->dev->dn_ptr : NULL;
229
230 if (dn && dn->use_long == 0)
231 min_mtu -= 6;
232 else
233 min_mtu -= 21;
234
235 if (dst->metrics[RTAX_MTU-1] > mtu && mtu >= min_mtu) {
236 if (!(dst_metric_locked(dst, RTAX_MTU))) {
237 dst->metrics[RTAX_MTU-1] = mtu;
238 dst_set_expires(dst, dn_rt_mtu_expires);
239 }
240 if (!(dst_metric_locked(dst, RTAX_ADVMSS))) {
241 u32 mss = mtu - DN_MAX_NSP_DATA_HEADER;
242 if (dst->metrics[RTAX_ADVMSS-1] > mss)
243 dst->metrics[RTAX_ADVMSS-1] = mss;
244 }
245 }
246 }
247
248 /*
249 * When a route has been marked obsolete. (e.g. routing cache flush)
250 */
251 static struct dst_entry *dn_dst_check(struct dst_entry *dst, __u32 cookie)
252 {
253 return NULL;
254 }
255
256 static struct dst_entry *dn_dst_negative_advice(struct dst_entry *dst)
257 {
258 dst_release(dst);
259 return NULL;
260 }
261
262 static void dn_dst_link_failure(struct sk_buff *skb)
263 {
264 return;
265 }
266
267 static inline int compare_keys(struct flowi *fl1, struct flowi *fl2)
268 {
269 return memcmp(&fl1->nl_u.dn_u, &fl2->nl_u.dn_u, sizeof(fl1->nl_u.dn_u)) == 0 &&
270 fl1->oif == fl2->oif &&
271 fl1->iif == fl2->iif;
272 }
273
274 static int dn_insert_route(struct dn_route *rt, unsigned hash, struct dn_route **rp)
275 {
276 struct dn_route *rth, **rthp;
277 unsigned long now = jiffies;
278
279 rthp = &dn_rt_hash_table[hash].chain;
280
281 spin_lock_bh(&dn_rt_hash_table[hash].lock);
282 while((rth = *rthp) != NULL) {
283 if (compare_keys(&rth->fl, &rt->fl)) {
284 /* Put it first */
285 *rthp = rth->u.rt_next;
286 rcu_assign_pointer(rth->u.rt_next,
287 dn_rt_hash_table[hash].chain);
288 rcu_assign_pointer(dn_rt_hash_table[hash].chain, rth);
289
290 rth->u.dst.__use++;
291 dst_hold(&rth->u.dst);
292 rth->u.dst.lastuse = now;
293 spin_unlock_bh(&dn_rt_hash_table[hash].lock);
294
295 dnrt_drop(rt);
296 *rp = rth;
297 return 0;
298 }
299 rthp = &rth->u.rt_next;
300 }
301
302 rcu_assign_pointer(rt->u.rt_next, dn_rt_hash_table[hash].chain);
303 rcu_assign_pointer(dn_rt_hash_table[hash].chain, rt);
304
305 dst_hold(&rt->u.dst);
306 rt->u.dst.__use++;
307 rt->u.dst.lastuse = now;
308 spin_unlock_bh(&dn_rt_hash_table[hash].lock);
309 *rp = rt;
310 return 0;
311 }
312
313 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->u.rt_next;
326 rt->u.rt_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 __le16 tmp;
383
384 /* Add back headers */
385 skb_push(skb, skb->data - skb->nh.raw);
386
387 if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
388 return NET_RX_DROP;
389
390 cb = DN_SKB_CB(skb);
391 /* Skip packet length and point to flags */
392 ptr = skb->data + 2;
393 *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
394
395 dst = (__le16 *)ptr;
396 ptr += 2;
397 src = (__le16 *)ptr;
398 ptr += 2;
399 *ptr = 0; /* Zero hop count */
400
401 /* Swap source and destination */
402 tmp = *src;
403 *src = *dst;
404 *dst = tmp;
405
406 skb->pkt_type = PACKET_OUTGOING;
407 dn_rt_finish_output(skb, NULL, NULL);
408 return NET_RX_SUCCESS;
409 }
410
411 /**
412 * dn_return_long - Return a long packet to its sender
413 * @skb: The long format packet to return
414 *
415 */
416 static int dn_return_long(struct sk_buff *skb)
417 {
418 struct dn_skb_cb *cb;
419 unsigned char *ptr;
420 unsigned char *src_addr, *dst_addr;
421 unsigned char tmp[ETH_ALEN];
422
423 /* Add back all headers */
424 skb_push(skb, skb->data - skb->nh.raw);
425
426 if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
427 return NET_RX_DROP;
428
429 cb = DN_SKB_CB(skb);
430 /* Ignore packet length and point to flags */
431 ptr = skb->data + 2;
432
433 /* Skip padding */
434 if (*ptr & DN_RT_F_PF) {
435 char padlen = (*ptr & ~DN_RT_F_PF);
436 ptr += padlen;
437 }
438
439 *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
440 ptr += 2;
441 dst_addr = ptr;
442 ptr += 8;
443 src_addr = ptr;
444 ptr += 6;
445 *ptr = 0; /* Zero hop count */
446
447 /* Swap source and destination */
448 memcpy(tmp, src_addr, ETH_ALEN);
449 memcpy(src_addr, dst_addr, ETH_ALEN);
450 memcpy(dst_addr, tmp, ETH_ALEN);
451
452 skb->pkt_type = PACKET_OUTGOING;
453 dn_rt_finish_output(skb, dst_addr, src_addr);
454 return NET_RX_SUCCESS;
455 }
456
457 /**
458 * dn_route_rx_packet - Try and find a route for an incoming packet
459 * @skb: The packet to find a route for
460 *
461 * Returns: result of input function if route is found, error code otherwise
462 */
463 static int dn_route_rx_packet(struct sk_buff *skb)
464 {
465 struct dn_skb_cb *cb = DN_SKB_CB(skb);
466 int err;
467
468 if ((err = dn_route_input(skb)) == 0)
469 return dst_input(skb);
470
471 if (decnet_debug_level & 4) {
472 char *devname = skb->dev ? skb->dev->name : "???";
473 struct dn_skb_cb *cb = DN_SKB_CB(skb);
474 printk(KERN_DEBUG
475 "DECnet: dn_route_rx_packet: rt_flags=0x%02x dev=%s len=%d src=0x%04hx dst=0x%04hx err=%d type=%d\n",
476 (int)cb->rt_flags, devname, skb->len,
477 dn_ntohs(cb->src), dn_ntohs(cb->dst),
478 err, skb->pkt_type);
479 }
480
481 if ((skb->pkt_type == PACKET_HOST) && (cb->rt_flags & DN_RT_F_RQR)) {
482 switch(cb->rt_flags & DN_RT_PKT_MSK) {
483 case DN_RT_PKT_SHORT:
484 return dn_return_short(skb);
485 case DN_RT_PKT_LONG:
486 return dn_return_long(skb);
487 }
488 }
489
490 kfree_skb(skb);
491 return NET_RX_DROP;
492 }
493
494 static int dn_route_rx_long(struct sk_buff *skb)
495 {
496 struct dn_skb_cb *cb = DN_SKB_CB(skb);
497 unsigned char *ptr = skb->data;
498
499 if (!pskb_may_pull(skb, 21)) /* 20 for long header, 1 for shortest nsp */
500 goto drop_it;
501
502 skb_pull(skb, 20);
503 skb->h.raw = skb->data;
504
505 /* Destination info */
506 ptr += 2;
507 cb->dst = dn_eth2dn(ptr);
508 if (memcmp(ptr, dn_hiord_addr, 4) != 0)
509 goto drop_it;
510 ptr += 6;
511
512
513 /* Source info */
514 ptr += 2;
515 cb->src = dn_eth2dn(ptr);
516 if (memcmp(ptr, dn_hiord_addr, 4) != 0)
517 goto drop_it;
518 ptr += 6;
519 /* Other junk */
520 ptr++;
521 cb->hops = *ptr++; /* Visit Count */
522
523 return NF_HOOK(PF_DECnet, NF_DN_PRE_ROUTING, skb, skb->dev, NULL, dn_route_rx_packet);
524
525 drop_it:
526 kfree_skb(skb);
527 return NET_RX_DROP;
528 }
529
530
531
532 static int dn_route_rx_short(struct sk_buff *skb)
533 {
534 struct dn_skb_cb *cb = DN_SKB_CB(skb);
535 unsigned char *ptr = skb->data;
536
537 if (!pskb_may_pull(skb, 6)) /* 5 for short header + 1 for shortest nsp */
538 goto drop_it;
539
540 skb_pull(skb, 5);
541 skb->h.raw = skb->data;
542
543 cb->dst = *(__le16 *)ptr;
544 ptr += 2;
545 cb->src = *(__le16 *)ptr;
546 ptr += 2;
547 cb->hops = *ptr & 0x3f;
548
549 return NF_HOOK(PF_DECnet, NF_DN_PRE_ROUTING, skb, skb->dev, NULL, dn_route_rx_packet);
550
551 drop_it:
552 kfree_skb(skb);
553 return NET_RX_DROP;
554 }
555
556 static int dn_route_discard(struct sk_buff *skb)
557 {
558 /*
559 * I know we drop the packet here, but thats considered success in
560 * this case
561 */
562 kfree_skb(skb);
563 return NET_RX_SUCCESS;
564 }
565
566 static int dn_route_ptp_hello(struct sk_buff *skb)
567 {
568 dn_dev_hello(skb);
569 dn_neigh_pointopoint_hello(skb);
570 return NET_RX_SUCCESS;
571 }
572
573 int dn_route_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
574 {
575 struct dn_skb_cb *cb;
576 unsigned char flags = 0;
577 __u16 len = dn_ntohs(*(__le16 *)skb->data);
578 struct dn_dev *dn = (struct dn_dev *)dev->dn_ptr;
579 unsigned char padlen = 0;
580
581 if (dn == NULL)
582 goto dump_it;
583
584 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
585 goto out;
586
587 if (!pskb_may_pull(skb, 3))
588 goto dump_it;
589
590 skb_pull(skb, 2);
591
592 if (len > skb->len)
593 goto dump_it;
594
595 skb_trim(skb, len);
596
597 flags = *skb->data;
598
599 cb = DN_SKB_CB(skb);
600 cb->stamp = jiffies;
601 cb->iif = dev->ifindex;
602
603 /*
604 * If we have padding, remove it.
605 */
606 if (flags & DN_RT_F_PF) {
607 padlen = flags & ~DN_RT_F_PF;
608 if (!pskb_may_pull(skb, padlen + 1))
609 goto dump_it;
610 skb_pull(skb, padlen);
611 flags = *skb->data;
612 }
613
614 skb->nh.raw = skb->data;
615
616 /*
617 * Weed out future version DECnet
618 */
619 if (flags & DN_RT_F_VER)
620 goto dump_it;
621
622 cb->rt_flags = flags;
623
624 if (decnet_debug_level & 1)
625 printk(KERN_DEBUG
626 "dn_route_rcv: got 0x%02x from %s [%d %d %d]\n",
627 (int)flags, (dev) ? dev->name : "???", len, skb->len,
628 padlen);
629
630 if (flags & DN_RT_PKT_CNTL) {
631 if (unlikely(skb_linearize(skb)))
632 goto dump_it;
633
634 switch(flags & DN_RT_CNTL_MSK) {
635 case DN_RT_PKT_INIT:
636 dn_dev_init_pkt(skb);
637 break;
638 case DN_RT_PKT_VERI:
639 dn_dev_veri_pkt(skb);
640 break;
641 }
642
643 if (dn->parms.state != DN_DEV_S_RU)
644 goto dump_it;
645
646 switch(flags & DN_RT_CNTL_MSK) {
647 case DN_RT_PKT_HELO:
648 return NF_HOOK(PF_DECnet, NF_DN_HELLO, skb, skb->dev, NULL, dn_route_ptp_hello);
649
650 case DN_RT_PKT_L1RT:
651 case DN_RT_PKT_L2RT:
652 return NF_HOOK(PF_DECnet, NF_DN_ROUTE, skb, skb->dev, NULL, dn_route_discard);
653 case DN_RT_PKT_ERTH:
654 return NF_HOOK(PF_DECnet, NF_DN_HELLO, skb, skb->dev, NULL, dn_neigh_router_hello);
655
656 case DN_RT_PKT_EEDH:
657 return NF_HOOK(PF_DECnet, NF_DN_HELLO, skb, skb->dev, NULL, dn_neigh_endnode_hello);
658 }
659 } else {
660 if (dn->parms.state != DN_DEV_S_RU)
661 goto dump_it;
662
663 skb_pull(skb, 1); /* Pull flags */
664
665 switch(flags & DN_RT_PKT_MSK) {
666 case DN_RT_PKT_LONG:
667 return dn_route_rx_long(skb);
668 case DN_RT_PKT_SHORT:
669 return dn_route_rx_short(skb);
670 }
671 }
672
673 dump_it:
674 kfree_skb(skb);
675 out:
676 return NET_RX_DROP;
677 }
678
679 static int dn_output(struct sk_buff *skb)
680 {
681 struct dst_entry *dst = skb->dst;
682 struct dn_route *rt = (struct dn_route *)dst;
683 struct net_device *dev = dst->dev;
684 struct dn_skb_cb *cb = DN_SKB_CB(skb);
685 struct neighbour *neigh;
686
687 int err = -EINVAL;
688
689 if ((neigh = dst->neighbour) == NULL)
690 goto error;
691
692 skb->dev = dev;
693
694 cb->src = rt->rt_saddr;
695 cb->dst = rt->rt_daddr;
696
697 /*
698 * Always set the Intra-Ethernet bit on all outgoing packets
699 * originated on this node. Only valid flag from upper layers
700 * is return-to-sender-requested. Set hop count to 0 too.
701 */
702 cb->rt_flags &= ~DN_RT_F_RQR;
703 cb->rt_flags |= DN_RT_F_IE;
704 cb->hops = 0;
705
706 return NF_HOOK(PF_DECnet, NF_DN_LOCAL_OUT, skb, NULL, dev, neigh->output);
707
708 error:
709 if (net_ratelimit())
710 printk(KERN_DEBUG "dn_output: This should not happen\n");
711
712 kfree_skb(skb);
713
714 return err;
715 }
716
717 static int dn_forward(struct sk_buff *skb)
718 {
719 struct dn_skb_cb *cb = DN_SKB_CB(skb);
720 struct dst_entry *dst = skb->dst;
721 struct dn_dev *dn_db = dst->dev->dn_ptr;
722 struct dn_route *rt;
723 struct neighbour *neigh = dst->neighbour;
724 int header_len;
725 #ifdef CONFIG_NETFILTER
726 struct net_device *dev = skb->dev;
727 #endif
728
729 if (skb->pkt_type != PACKET_HOST)
730 goto drop;
731
732 /* Ensure that we have enough space for headers */
733 rt = (struct dn_route *)skb->dst;
734 header_len = dn_db->use_long ? 21 : 6;
735 if (skb_cow(skb, LL_RESERVED_SPACE(rt->u.dst.dev)+header_len))
736 goto drop;
737
738 /*
739 * Hop count exceeded.
740 */
741 if (++cb->hops > 30)
742 goto drop;
743
744 skb->dev = rt->u.dst.dev;
745
746 /*
747 * If packet goes out same interface it came in on, then set
748 * the Intra-Ethernet bit. This has no effect for short
749 * packets, so we don't need to test for them here.
750 */
751 cb->rt_flags &= ~DN_RT_F_IE;
752 if (rt->rt_flags & RTCF_DOREDIRECT)
753 cb->rt_flags |= DN_RT_F_IE;
754
755 return NF_HOOK(PF_DECnet, NF_DN_FORWARD, skb, dev, skb->dev, neigh->output);
756
757 drop:
758 kfree_skb(skb);
759 return NET_RX_DROP;
760 }
761
762 /*
763 * Drop packet. This is used for endnodes and for
764 * when we should not be forwarding packets from
765 * this dest.
766 */
767 static int dn_blackhole(struct sk_buff *skb)
768 {
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 dn_ntohs(cb->src), dn_ntohs(cb->dst));
784 }
785
786 kfree_skb(skb);
787
788 return NET_RX_BAD;
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->u.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->u.dst.metrics, fi->fib_metrics,
803 sizeof(rt->u.dst.metrics));
804 }
805 rt->rt_type = res->type;
806
807 if (dev != NULL && rt->u.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->u.dst.neighbour = n;
812 }
813
814 if (rt->u.dst.metrics[RTAX_MTU-1] == 0 ||
815 rt->u.dst.metrics[RTAX_MTU-1] > rt->u.dst.dev->mtu)
816 rt->u.dst.metrics[RTAX_MTU-1] = rt->u.dst.dev->mtu;
817 mss = dn_mss_from_pmtu(dev, dst_mtu(&rt->u.dst));
818 if (rt->u.dst.metrics[RTAX_ADVMSS-1] == 0 ||
819 rt->u.dst.metrics[RTAX_ADVMSS-1] > mss)
820 rt->u.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 = dn_ntohs(addr1) ^ dn_ntohs(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 #ifdef CONFIG_DECNET_ROUTE_FWMARK
880 .fwmark = oldflp->fld_fwmark
881 #endif
882 } },
883 .iif = loopback_dev.ifindex,
884 .oif = oldflp->oif };
885 struct dn_route *rt = NULL;
886 struct net_device *dev_out = NULL;
887 struct neighbour *neigh = NULL;
888 unsigned hash;
889 unsigned flags = 0;
890 struct dn_fib_res res = { .fi = NULL, .type = RTN_UNICAST };
891 int err;
892 int free_res = 0;
893 __le16 gateway = 0;
894
895 if (decnet_debug_level & 16)
896 printk(KERN_DEBUG
897 "dn_route_output_slow: dst=%04x src=%04x mark=%d"
898 " iif=%d oif=%d\n", dn_ntohs(oldflp->fld_dst),
899 dn_ntohs(oldflp->fld_src),
900 oldflp->fld_fwmark, loopback_dev.ifindex, oldflp->oif);
901
902 /* If we have an output interface, verify its a DECnet device */
903 if (oldflp->oif) {
904 dev_out = dev_get_by_index(oldflp->oif);
905 err = -ENODEV;
906 if (dev_out && dev_out->dn_ptr == NULL) {
907 dev_put(dev_out);
908 dev_out = NULL;
909 }
910 if (dev_out == NULL)
911 goto out;
912 }
913
914 /* If we have a source address, verify that its a local address */
915 if (oldflp->fld_src) {
916 err = -EADDRNOTAVAIL;
917
918 if (dev_out) {
919 if (dn_dev_islocal(dev_out, oldflp->fld_src))
920 goto source_ok;
921 dev_put(dev_out);
922 goto out;
923 }
924 read_lock(&dev_base_lock);
925 for(dev_out = dev_base; dev_out; dev_out = dev_out->next) {
926 if (!dev_out->dn_ptr)
927 continue;
928 if (dn_dev_islocal(dev_out, oldflp->fld_src))
929 break;
930 }
931 read_unlock(&dev_base_lock);
932 if (dev_out == NULL)
933 goto out;
934 dev_hold(dev_out);
935 source_ok:
936 ;
937 }
938
939 /* No destination? Assume its local */
940 if (!fl.fld_dst) {
941 fl.fld_dst = fl.fld_src;
942
943 err = -EADDRNOTAVAIL;
944 if (dev_out)
945 dev_put(dev_out);
946 dev_out = &loopback_dev;
947 dev_hold(dev_out);
948 if (!fl.fld_dst) {
949 fl.fld_dst =
950 fl.fld_src = dnet_select_source(dev_out, 0,
951 RT_SCOPE_HOST);
952 if (!fl.fld_dst)
953 goto out;
954 }
955 fl.oif = loopback_dev.ifindex;
956 res.type = RTN_LOCAL;
957 goto make_route;
958 }
959
960 if (decnet_debug_level & 16)
961 printk(KERN_DEBUG
962 "dn_route_output_slow: initial checks complete."
963 " dst=%o4x src=%04x oif=%d try_hard=%d\n",
964 dn_ntohs(fl.fld_dst), dn_ntohs(fl.fld_src),
965 fl.oif, try_hard);
966
967 /*
968 * N.B. If the kernel is compiled without router support then
969 * dn_fib_lookup() will evaluate to non-zero so this if () block
970 * will always be executed.
971 */
972 err = -ESRCH;
973 if (try_hard || (err = dn_fib_lookup(&fl, &res)) != 0) {
974 struct dn_dev *dn_db;
975 if (err != -ESRCH)
976 goto out;
977 /*
978 * Here the fallback is basically the standard algorithm for
979 * routing in endnodes which is described in the DECnet routing
980 * docs
981 *
982 * If we are not trying hard, look in neighbour cache.
983 * The result is tested to ensure that if a specific output
984 * device/source address was requested, then we honour that
985 * here
986 */
987 if (!try_hard) {
988 neigh = neigh_lookup_nodev(&dn_neigh_table, &fl.fld_dst);
989 if (neigh) {
990 if ((oldflp->oif &&
991 (neigh->dev->ifindex != oldflp->oif)) ||
992 (oldflp->fld_src &&
993 (!dn_dev_islocal(neigh->dev,
994 oldflp->fld_src)))) {
995 neigh_release(neigh);
996 neigh = NULL;
997 } else {
998 if (dev_out)
999 dev_put(dev_out);
1000 if (dn_dev_islocal(neigh->dev, fl.fld_dst)) {
1001 dev_out = &loopback_dev;
1002 res.type = RTN_LOCAL;
1003 } else {
1004 dev_out = neigh->dev;
1005 }
1006 dev_hold(dev_out);
1007 goto select_source;
1008 }
1009 }
1010 }
1011
1012 /* Not there? Perhaps its a local address */
1013 if (dev_out == NULL)
1014 dev_out = dn_dev_get_default();
1015 err = -ENODEV;
1016 if (dev_out == NULL)
1017 goto out;
1018 dn_db = dev_out->dn_ptr;
1019 /* Possible improvement - check all devices for local addr */
1020 if (dn_dev_islocal(dev_out, fl.fld_dst)) {
1021 dev_put(dev_out);
1022 dev_out = &loopback_dev;
1023 dev_hold(dev_out);
1024 res.type = RTN_LOCAL;
1025 goto select_source;
1026 }
1027 /* Not local either.... try sending it to the default router */
1028 neigh = neigh_clone(dn_db->router);
1029 BUG_ON(neigh && neigh->dev != dev_out);
1030
1031 /* Ok then, we assume its directly connected and move on */
1032 select_source:
1033 if (neigh)
1034 gateway = ((struct dn_neigh *)neigh)->addr;
1035 if (gateway == 0)
1036 gateway = fl.fld_dst;
1037 if (fl.fld_src == 0) {
1038 fl.fld_src = dnet_select_source(dev_out, gateway,
1039 res.type == RTN_LOCAL ?
1040 RT_SCOPE_HOST :
1041 RT_SCOPE_LINK);
1042 if (fl.fld_src == 0 && res.type != RTN_LOCAL)
1043 goto e_addr;
1044 }
1045 fl.oif = dev_out->ifindex;
1046 goto make_route;
1047 }
1048 free_res = 1;
1049
1050 if (res.type == RTN_NAT)
1051 goto e_inval;
1052
1053 if (res.type == RTN_LOCAL) {
1054 if (!fl.fld_src)
1055 fl.fld_src = fl.fld_dst;
1056 if (dev_out)
1057 dev_put(dev_out);
1058 dev_out = &loopback_dev;
1059 dev_hold(dev_out);
1060 fl.oif = dev_out->ifindex;
1061 if (res.fi)
1062 dn_fib_info_put(res.fi);
1063 res.fi = NULL;
1064 goto make_route;
1065 }
1066
1067 if (res.fi->fib_nhs > 1 && fl.oif == 0)
1068 dn_fib_select_multipath(&fl, &res);
1069
1070 /*
1071 * We could add some logic to deal with default routes here and
1072 * get rid of some of the special casing above.
1073 */
1074
1075 if (!fl.fld_src)
1076 fl.fld_src = DN_FIB_RES_PREFSRC(res);
1077
1078 if (dev_out)
1079 dev_put(dev_out);
1080 dev_out = DN_FIB_RES_DEV(res);
1081 dev_hold(dev_out);
1082 fl.oif = dev_out->ifindex;
1083 gateway = DN_FIB_RES_GW(res);
1084
1085 make_route:
1086 if (dev_out->flags & IFF_LOOPBACK)
1087 flags |= RTCF_LOCAL;
1088
1089 rt = dst_alloc(&dn_dst_ops);
1090 if (rt == NULL)
1091 goto e_nobufs;
1092
1093 atomic_set(&rt->u.dst.__refcnt, 1);
1094 rt->u.dst.flags = DST_HOST;
1095
1096 rt->fl.fld_src = oldflp->fld_src;
1097 rt->fl.fld_dst = oldflp->fld_dst;
1098 rt->fl.oif = oldflp->oif;
1099 rt->fl.iif = 0;
1100 #ifdef CONFIG_DECNET_ROUTE_FWMARK
1101 rt->fl.fld_fwmark = oldflp->fld_fwmark;
1102 #endif
1103
1104 rt->rt_saddr = fl.fld_src;
1105 rt->rt_daddr = fl.fld_dst;
1106 rt->rt_gateway = gateway ? gateway : fl.fld_dst;
1107 rt->rt_local_src = fl.fld_src;
1108
1109 rt->rt_dst_map = fl.fld_dst;
1110 rt->rt_src_map = fl.fld_src;
1111
1112 rt->u.dst.dev = dev_out;
1113 dev_hold(dev_out);
1114 rt->u.dst.neighbour = neigh;
1115 neigh = NULL;
1116
1117 rt->u.dst.lastuse = jiffies;
1118 rt->u.dst.output = dn_output;
1119 rt->u.dst.input = dn_rt_bug;
1120 rt->rt_flags = flags;
1121 if (flags & RTCF_LOCAL)
1122 rt->u.dst.input = dn_nsp_rx;
1123
1124 err = dn_rt_set_next_hop(rt, &res);
1125 if (err)
1126 goto e_neighbour;
1127
1128 hash = dn_hash(rt->fl.fld_src, rt->fl.fld_dst);
1129 dn_insert_route(rt, hash, (struct dn_route **)pprt);
1130
1131 done:
1132 if (neigh)
1133 neigh_release(neigh);
1134 if (free_res)
1135 dn_fib_res_put(&res);
1136 if (dev_out)
1137 dev_put(dev_out);
1138 out:
1139 return err;
1140
1141 e_addr:
1142 err = -EADDRNOTAVAIL;
1143 goto done;
1144 e_inval:
1145 err = -EINVAL;
1146 goto done;
1147 e_nobufs:
1148 err = -ENOBUFS;
1149 goto done;
1150 e_neighbour:
1151 dst_free(&rt->u.dst);
1152 goto e_nobufs;
1153 }
1154
1155
1156 /*
1157 * N.B. The flags may be moved into the flowi at some future stage.
1158 */
1159 static int __dn_route_output_key(struct dst_entry **pprt, const struct flowi *flp, int flags)
1160 {
1161 unsigned hash = dn_hash(flp->fld_src, flp->fld_dst);
1162 struct dn_route *rt = NULL;
1163
1164 if (!(flags & MSG_TRYHARD)) {
1165 rcu_read_lock_bh();
1166 for(rt = rcu_dereference(dn_rt_hash_table[hash].chain); rt;
1167 rt = rcu_dereference(rt->u.rt_next)) {
1168 if ((flp->fld_dst == rt->fl.fld_dst) &&
1169 (flp->fld_src == rt->fl.fld_src) &&
1170 #ifdef CONFIG_DECNET_ROUTE_FWMARK
1171 (flp->fld_fwmark == rt->fl.fld_fwmark) &&
1172 #endif
1173 (rt->fl.iif == 0) &&
1174 (rt->fl.oif == flp->oif)) {
1175 rt->u.dst.lastuse = jiffies;
1176 dst_hold(&rt->u.dst);
1177 rt->u.dst.__use++;
1178 rcu_read_unlock_bh();
1179 *pprt = &rt->u.dst;
1180 return 0;
1181 }
1182 }
1183 rcu_read_unlock_bh();
1184 }
1185
1186 return dn_route_output_slow(pprt, flp, flags);
1187 }
1188
1189 static int dn_route_output_key(struct dst_entry **pprt, struct flowi *flp, int flags)
1190 {
1191 int err;
1192
1193 err = __dn_route_output_key(pprt, flp, flags);
1194 if (err == 0 && flp->proto) {
1195 err = xfrm_lookup(pprt, flp, NULL, 0);
1196 }
1197 return err;
1198 }
1199
1200 int dn_route_output_sock(struct dst_entry **pprt, struct flowi *fl, struct sock *sk, int flags)
1201 {
1202 int err;
1203
1204 err = __dn_route_output_key(pprt, fl, flags & MSG_TRYHARD);
1205 if (err == 0 && fl->proto) {
1206 err = xfrm_lookup(pprt, fl, sk, !(flags & MSG_DONTWAIT));
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 #ifdef CONFIG_DECNET_ROUTE_FWMARK
1228 .fwmark = skb->nfmark
1229 #endif
1230 } },
1231 .iif = skb->dev->ifindex };
1232 struct dn_fib_res res = { .fi = NULL, .type = RTN_UNREACHABLE };
1233 int err = -EINVAL;
1234 int free_res = 0;
1235
1236 dev_hold(in_dev);
1237
1238 if ((dn_db = in_dev->dn_ptr) == NULL)
1239 goto out;
1240
1241 /* Zero source addresses are not allowed */
1242 if (fl.fld_src == 0)
1243 goto out;
1244
1245 /*
1246 * In this case we've just received a packet from a source
1247 * outside ourselves pretending to come from us. We don't
1248 * allow it any further to prevent routing loops, spoofing and
1249 * other nasties. Loopback packets already have the dst attached
1250 * so this only affects packets which have originated elsewhere.
1251 */
1252 err = -ENOTUNIQ;
1253 if (dn_dev_islocal(in_dev, cb->src))
1254 goto out;
1255
1256 err = dn_fib_lookup(&fl, &res);
1257 if (err) {
1258 if (err != -ESRCH)
1259 goto out;
1260 /*
1261 * Is the destination us ?
1262 */
1263 if (!dn_dev_islocal(in_dev, cb->dst))
1264 goto e_inval;
1265
1266 res.type = RTN_LOCAL;
1267 flags |= RTCF_DIRECTSRC;
1268 } else {
1269 __le16 src_map = fl.fld_src;
1270 free_res = 1;
1271
1272 out_dev = DN_FIB_RES_DEV(res);
1273 if (out_dev == NULL) {
1274 if (net_ratelimit())
1275 printk(KERN_CRIT "Bug in dn_route_input_slow() "
1276 "No output device\n");
1277 goto e_inval;
1278 }
1279 dev_hold(out_dev);
1280
1281 if (res.r)
1282 src_map = dn_fib_rules_policy(fl.fld_src, &res, &flags);
1283
1284 gateway = DN_FIB_RES_GW(res);
1285 if (res.type == RTN_NAT) {
1286 fl.fld_dst = dn_fib_rules_map_destination(fl.fld_dst, &res);
1287 dn_fib_res_put(&res);
1288 free_res = 0;
1289 if (dn_fib_lookup(&fl, &res))
1290 goto e_inval;
1291 free_res = 1;
1292 if (res.type != RTN_UNICAST)
1293 goto e_inval;
1294 flags |= RTCF_DNAT;
1295 gateway = fl.fld_dst;
1296 }
1297 fl.fld_src = src_map;
1298 }
1299
1300 switch(res.type) {
1301 case RTN_UNICAST:
1302 /*
1303 * Forwarding check here, we only check for forwarding
1304 * being turned off, if you want to only forward intra
1305 * area, its up to you to set the routing tables up
1306 * correctly.
1307 */
1308 if (dn_db->parms.forwarding == 0)
1309 goto e_inval;
1310
1311 if (res.fi->fib_nhs > 1 && fl.oif == 0)
1312 dn_fib_select_multipath(&fl, &res);
1313
1314 /*
1315 * Check for out_dev == in_dev. We use the RTCF_DOREDIRECT
1316 * flag as a hint to set the intra-ethernet bit when
1317 * forwarding. If we've got NAT in operation, we don't do
1318 * this optimisation.
1319 */
1320 if (out_dev == in_dev && !(flags & RTCF_NAT))
1321 flags |= RTCF_DOREDIRECT;
1322
1323 local_src = DN_FIB_RES_PREFSRC(res);
1324
1325 case RTN_BLACKHOLE:
1326 case RTN_UNREACHABLE:
1327 break;
1328 case RTN_LOCAL:
1329 flags |= RTCF_LOCAL;
1330 fl.fld_src = cb->dst;
1331 fl.fld_dst = cb->src;
1332
1333 /* Routing tables gave us a gateway */
1334 if (gateway)
1335 goto make_route;
1336
1337 /* Packet was intra-ethernet, so we know its on-link */
1338 if (cb->rt_flags | DN_RT_F_IE) {
1339 gateway = cb->src;
1340 flags |= RTCF_DIRECTSRC;
1341 goto make_route;
1342 }
1343
1344 /* Use the default router if there is one */
1345 neigh = neigh_clone(dn_db->router);
1346 if (neigh) {
1347 gateway = ((struct dn_neigh *)neigh)->addr;
1348 goto make_route;
1349 }
1350
1351 /* Close eyes and pray */
1352 gateway = cb->src;
1353 flags |= RTCF_DIRECTSRC;
1354 goto make_route;
1355 default:
1356 goto e_inval;
1357 }
1358
1359 make_route:
1360 rt = dst_alloc(&dn_dst_ops);
1361 if (rt == NULL)
1362 goto e_nobufs;
1363
1364 rt->rt_saddr = fl.fld_src;
1365 rt->rt_daddr = fl.fld_dst;
1366 rt->rt_gateway = fl.fld_dst;
1367 if (gateway)
1368 rt->rt_gateway = gateway;
1369 rt->rt_local_src = local_src ? local_src : rt->rt_saddr;
1370
1371 rt->rt_dst_map = fl.fld_dst;
1372 rt->rt_src_map = fl.fld_src;
1373
1374 rt->fl.fld_src = cb->src;
1375 rt->fl.fld_dst = cb->dst;
1376 rt->fl.oif = 0;
1377 rt->fl.iif = in_dev->ifindex;
1378 rt->fl.fld_fwmark = fl.fld_fwmark;
1379
1380 rt->u.dst.flags = DST_HOST;
1381 rt->u.dst.neighbour = neigh;
1382 rt->u.dst.dev = out_dev;
1383 rt->u.dst.lastuse = jiffies;
1384 rt->u.dst.output = dn_rt_bug;
1385 switch(res.type) {
1386 case RTN_UNICAST:
1387 rt->u.dst.input = dn_forward;
1388 break;
1389 case RTN_LOCAL:
1390 rt->u.dst.output = dn_output;
1391 rt->u.dst.input = dn_nsp_rx;
1392 rt->u.dst.dev = in_dev;
1393 flags |= RTCF_LOCAL;
1394 break;
1395 default:
1396 case RTN_UNREACHABLE:
1397 case RTN_BLACKHOLE:
1398 rt->u.dst.input = dn_blackhole;
1399 }
1400 rt->rt_flags = flags;
1401 if (rt->u.dst.dev)
1402 dev_hold(rt->u.dst.dev);
1403
1404 err = dn_rt_set_next_hop(rt, &res);
1405 if (err)
1406 goto e_neighbour;
1407
1408 hash = dn_hash(rt->fl.fld_src, rt->fl.fld_dst);
1409 dn_insert_route(rt, hash, (struct dn_route **)&skb->dst);
1410
1411 done:
1412 if (neigh)
1413 neigh_release(neigh);
1414 if (free_res)
1415 dn_fib_res_put(&res);
1416 dev_put(in_dev);
1417 if (out_dev)
1418 dev_put(out_dev);
1419 out:
1420 return err;
1421
1422 e_inval:
1423 err = -EINVAL;
1424 goto done;
1425
1426 e_nobufs:
1427 err = -ENOBUFS;
1428 goto done;
1429
1430 e_neighbour:
1431 dst_free(&rt->u.dst);
1432 goto done;
1433 }
1434
1435 int dn_route_input(struct sk_buff *skb)
1436 {
1437 struct dn_route *rt;
1438 struct dn_skb_cb *cb = DN_SKB_CB(skb);
1439 unsigned hash = dn_hash(cb->src, cb->dst);
1440
1441 if (skb->dst)
1442 return 0;
1443
1444 rcu_read_lock();
1445 for(rt = rcu_dereference(dn_rt_hash_table[hash].chain); rt != NULL;
1446 rt = rcu_dereference(rt->u.rt_next)) {
1447 if ((rt->fl.fld_src == cb->src) &&
1448 (rt->fl.fld_dst == cb->dst) &&
1449 (rt->fl.oif == 0) &&
1450 #ifdef CONFIG_DECNET_ROUTE_FWMARK
1451 (rt->fl.fld_fwmark == skb->nfmark) &&
1452 #endif
1453 (rt->fl.iif == cb->iif)) {
1454 rt->u.dst.lastuse = jiffies;
1455 dst_hold(&rt->u.dst);
1456 rt->u.dst.__use++;
1457 rcu_read_unlock();
1458 skb->dst = (struct dst_entry *)rt;
1459 return 0;
1460 }
1461 }
1462 rcu_read_unlock();
1463
1464 return dn_route_input_slow(skb);
1465 }
1466
1467 static int dn_rt_fill_info(struct sk_buff *skb, u32 pid, u32 seq,
1468 int event, int nowait, unsigned int flags)
1469 {
1470 struct dn_route *rt = (struct dn_route *)skb->dst;
1471 struct rtmsg *r;
1472 struct nlmsghdr *nlh;
1473 unsigned char *b = skb->tail;
1474 struct rta_cacheinfo ci;
1475
1476 nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*r), flags);
1477 r = NLMSG_DATA(nlh);
1478 r->rtm_family = AF_DECnet;
1479 r->rtm_dst_len = 16;
1480 r->rtm_src_len = 0;
1481 r->rtm_tos = 0;
1482 r->rtm_table = RT_TABLE_MAIN;
1483 r->rtm_type = rt->rt_type;
1484 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
1485 r->rtm_scope = RT_SCOPE_UNIVERSE;
1486 r->rtm_protocol = RTPROT_UNSPEC;
1487 if (rt->rt_flags & RTCF_NOTIFY)
1488 r->rtm_flags |= RTM_F_NOTIFY;
1489 RTA_PUT(skb, RTA_DST, 2, &rt->rt_daddr);
1490 if (rt->fl.fld_src) {
1491 r->rtm_src_len = 16;
1492 RTA_PUT(skb, RTA_SRC, 2, &rt->fl.fld_src);
1493 }
1494 if (rt->u.dst.dev)
1495 RTA_PUT(skb, RTA_OIF, sizeof(int), &rt->u.dst.dev->ifindex);
1496 /*
1497 * Note to self - change this if input routes reverse direction when
1498 * they deal only with inputs and not with replies like they do
1499 * currently.
1500 */
1501 RTA_PUT(skb, RTA_PREFSRC, 2, &rt->rt_local_src);
1502 if (rt->rt_daddr != rt->rt_gateway)
1503 RTA_PUT(skb, RTA_GATEWAY, 2, &rt->rt_gateway);
1504 if (rtnetlink_put_metrics(skb, rt->u.dst.metrics) < 0)
1505 goto rtattr_failure;
1506 ci.rta_lastuse = jiffies_to_clock_t(jiffies - rt->u.dst.lastuse);
1507 ci.rta_used = rt->u.dst.__use;
1508 ci.rta_clntref = atomic_read(&rt->u.dst.__refcnt);
1509 if (rt->u.dst.expires)
1510 ci.rta_expires = jiffies_to_clock_t(rt->u.dst.expires - jiffies);
1511 else
1512 ci.rta_expires = 0;
1513 ci.rta_error = rt->u.dst.error;
1514 ci.rta_id = ci.rta_ts = ci.rta_tsage = 0;
1515 RTA_PUT(skb, RTA_CACHEINFO, sizeof(ci), &ci);
1516 if (rt->fl.iif)
1517 RTA_PUT(skb, RTA_IIF, sizeof(int), &rt->fl.iif);
1518
1519 nlh->nlmsg_len = skb->tail - b;
1520 return skb->len;
1521
1522 nlmsg_failure:
1523 rtattr_failure:
1524 skb_trim(skb, b - skb->data);
1525 return -1;
1526 }
1527
1528 /*
1529 * This is called by both endnodes and routers now.
1530 */
1531 int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, void *arg)
1532 {
1533 struct rtattr **rta = arg;
1534 struct rtmsg *rtm = NLMSG_DATA(nlh);
1535 struct dn_route *rt = NULL;
1536 struct dn_skb_cb *cb;
1537 int err;
1538 struct sk_buff *skb;
1539 struct flowi fl;
1540
1541 memset(&fl, 0, sizeof(fl));
1542 fl.proto = DNPROTO_NSP;
1543
1544 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1545 if (skb == NULL)
1546 return -ENOBUFS;
1547 skb->mac.raw = skb->data;
1548 cb = DN_SKB_CB(skb);
1549
1550 if (rta[RTA_SRC-1])
1551 memcpy(&fl.fld_src, RTA_DATA(rta[RTA_SRC-1]), 2);
1552 if (rta[RTA_DST-1])
1553 memcpy(&fl.fld_dst, RTA_DATA(rta[RTA_DST-1]), 2);
1554 if (rta[RTA_IIF-1])
1555 memcpy(&fl.iif, RTA_DATA(rta[RTA_IIF-1]), sizeof(int));
1556
1557 if (fl.iif) {
1558 struct net_device *dev;
1559 if ((dev = dev_get_by_index(fl.iif)) == NULL) {
1560 kfree_skb(skb);
1561 return -ENODEV;
1562 }
1563 if (!dev->dn_ptr) {
1564 dev_put(dev);
1565 kfree_skb(skb);
1566 return -ENODEV;
1567 }
1568 skb->protocol = __constant_htons(ETH_P_DNA_RT);
1569 skb->dev = dev;
1570 cb->src = fl.fld_src;
1571 cb->dst = fl.fld_dst;
1572 local_bh_disable();
1573 err = dn_route_input(skb);
1574 local_bh_enable();
1575 memset(cb, 0, sizeof(struct dn_skb_cb));
1576 rt = (struct dn_route *)skb->dst;
1577 if (!err && -rt->u.dst.error)
1578 err = rt->u.dst.error;
1579 } else {
1580 int oif = 0;
1581 if (rta[RTA_OIF - 1])
1582 memcpy(&oif, RTA_DATA(rta[RTA_OIF - 1]), sizeof(int));
1583 fl.oif = oif;
1584 err = dn_route_output_key((struct dst_entry **)&rt, &fl, 0);
1585 }
1586
1587 if (skb->dev)
1588 dev_put(skb->dev);
1589 skb->dev = NULL;
1590 if (err)
1591 goto out_free;
1592 skb->dst = &rt->u.dst;
1593 if (rtm->rtm_flags & RTM_F_NOTIFY)
1594 rt->rt_flags |= RTCF_NOTIFY;
1595
1596 NETLINK_CB(skb).dst_pid = NETLINK_CB(in_skb).pid;
1597
1598 err = dn_rt_fill_info(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, RTM_NEWROUTE, 0, 0);
1599
1600 if (err == 0)
1601 goto out_free;
1602 if (err < 0) {
1603 err = -EMSGSIZE;
1604 goto out_free;
1605 }
1606
1607 err = netlink_unicast(rtnl, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT);
1608
1609 return err;
1610
1611 out_free:
1612 kfree_skb(skb);
1613 return err;
1614 }
1615
1616 /*
1617 * For routers, this is called from dn_fib_dump, but for endnodes its
1618 * called directly from the rtnetlink dispatch table.
1619 */
1620 int dn_cache_dump(struct sk_buff *skb, struct netlink_callback *cb)
1621 {
1622 struct dn_route *rt;
1623 int h, s_h;
1624 int idx, s_idx;
1625
1626 if (NLMSG_PAYLOAD(cb->nlh, 0) < sizeof(struct rtmsg))
1627 return -EINVAL;
1628 if (!(((struct rtmsg *)NLMSG_DATA(cb->nlh))->rtm_flags&RTM_F_CLONED))
1629 return 0;
1630
1631 s_h = cb->args[0];
1632 s_idx = idx = cb->args[1];
1633 for(h = 0; h <= dn_rt_hash_mask; h++) {
1634 if (h < s_h)
1635 continue;
1636 if (h > s_h)
1637 s_idx = 0;
1638 rcu_read_lock_bh();
1639 for(rt = rcu_dereference(dn_rt_hash_table[h].chain), idx = 0;
1640 rt;
1641 rt = rcu_dereference(rt->u.rt_next), idx++) {
1642 if (idx < s_idx)
1643 continue;
1644 skb->dst = dst_clone(&rt->u.dst);
1645 if (dn_rt_fill_info(skb, NETLINK_CB(cb->skb).pid,
1646 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
1647 1, NLM_F_MULTI) <= 0) {
1648 dst_release(xchg(&skb->dst, NULL));
1649 rcu_read_unlock_bh();
1650 goto done;
1651 }
1652 dst_release(xchg(&skb->dst, NULL));
1653 }
1654 rcu_read_unlock_bh();
1655 }
1656
1657 done:
1658 cb->args[0] = h;
1659 cb->args[1] = idx;
1660 return skb->len;
1661 }
1662
1663 #ifdef CONFIG_PROC_FS
1664 struct dn_rt_cache_iter_state {
1665 int bucket;
1666 };
1667
1668 static struct dn_route *dn_rt_cache_get_first(struct seq_file *seq)
1669 {
1670 struct dn_route *rt = NULL;
1671 struct dn_rt_cache_iter_state *s = seq->private;
1672
1673 for(s->bucket = dn_rt_hash_mask; s->bucket >= 0; --s->bucket) {
1674 rcu_read_lock_bh();
1675 rt = dn_rt_hash_table[s->bucket].chain;
1676 if (rt)
1677 break;
1678 rcu_read_unlock_bh();
1679 }
1680 return rt;
1681 }
1682
1683 static struct dn_route *dn_rt_cache_get_next(struct seq_file *seq, struct dn_route *rt)
1684 {
1685 struct dn_rt_cache_iter_state *s = rcu_dereference(seq->private);
1686
1687 rt = rt->u.rt_next;
1688 while(!rt) {
1689 rcu_read_unlock_bh();
1690 if (--s->bucket < 0)
1691 break;
1692 rcu_read_lock_bh();
1693 rt = dn_rt_hash_table[s->bucket].chain;
1694 }
1695 return rt;
1696 }
1697
1698 static void *dn_rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
1699 {
1700 struct dn_route *rt = dn_rt_cache_get_first(seq);
1701
1702 if (rt) {
1703 while(*pos && (rt = dn_rt_cache_get_next(seq, rt)))
1704 --*pos;
1705 }
1706 return *pos ? NULL : rt;
1707 }
1708
1709 static void *dn_rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1710 {
1711 struct dn_route *rt = dn_rt_cache_get_next(seq, v);
1712 ++*pos;
1713 return rt;
1714 }
1715
1716 static void dn_rt_cache_seq_stop(struct seq_file *seq, void *v)
1717 {
1718 if (v)
1719 rcu_read_unlock_bh();
1720 }
1721
1722 static int dn_rt_cache_seq_show(struct seq_file *seq, void *v)
1723 {
1724 struct dn_route *rt = v;
1725 char buf1[DN_ASCBUF_LEN], buf2[DN_ASCBUF_LEN];
1726
1727 seq_printf(seq, "%-8s %-7s %-7s %04d %04d %04d\n",
1728 rt->u.dst.dev ? rt->u.dst.dev->name : "*",
1729 dn_addr2asc(dn_ntohs(rt->rt_daddr), buf1),
1730 dn_addr2asc(dn_ntohs(rt->rt_saddr), buf2),
1731 atomic_read(&rt->u.dst.__refcnt),
1732 rt->u.dst.__use,
1733 (int) dst_metric(&rt->u.dst, RTAX_RTT));
1734 return 0;
1735 }
1736
1737 static struct seq_operations dn_rt_cache_seq_ops = {
1738 .start = dn_rt_cache_seq_start,
1739 .next = dn_rt_cache_seq_next,
1740 .stop = dn_rt_cache_seq_stop,
1741 .show = dn_rt_cache_seq_show,
1742 };
1743
1744 static int dn_rt_cache_seq_open(struct inode *inode, struct file *file)
1745 {
1746 struct seq_file *seq;
1747 int rc = -ENOMEM;
1748 struct dn_rt_cache_iter_state *s = kmalloc(sizeof(*s), GFP_KERNEL);
1749
1750 if (!s)
1751 goto out;
1752 rc = seq_open(file, &dn_rt_cache_seq_ops);
1753 if (rc)
1754 goto out_kfree;
1755 seq = file->private_data;
1756 seq->private = s;
1757 memset(s, 0, sizeof(*s));
1758 out:
1759 return rc;
1760 out_kfree:
1761 kfree(s);
1762 goto out;
1763 }
1764
1765 static struct file_operations dn_rt_cache_seq_fops = {
1766 .owner = THIS_MODULE,
1767 .open = dn_rt_cache_seq_open,
1768 .read = seq_read,
1769 .llseek = seq_lseek,
1770 .release = seq_release_private,
1771 };
1772
1773 #endif /* CONFIG_PROC_FS */
1774
1775 void __init dn_route_init(void)
1776 {
1777 int i, goal, order;
1778
1779 dn_dst_ops.kmem_cachep = kmem_cache_create("dn_dst_cache",
1780 sizeof(struct dn_route),
1781 0, SLAB_HWCACHE_ALIGN,
1782 NULL, NULL);
1783
1784 if (!dn_dst_ops.kmem_cachep)
1785 panic("DECnet: Failed to allocate dn_dst_cache\n");
1786
1787 init_timer(&dn_route_timer);
1788 dn_route_timer.function = dn_dst_check_expire;
1789 dn_route_timer.expires = jiffies + decnet_dst_gc_interval * HZ;
1790 add_timer(&dn_route_timer);
1791
1792 goal = num_physpages >> (26 - PAGE_SHIFT);
1793
1794 for(order = 0; (1UL << order) < goal; order++)
1795 /* NOTHING */;
1796
1797 /*
1798 * Only want 1024 entries max, since the table is very, very unlikely
1799 * to be larger than that.
1800 */
1801 while(order && ((((1UL << order) * PAGE_SIZE) /
1802 sizeof(struct dn_rt_hash_bucket)) >= 2048))
1803 order--;
1804
1805 do {
1806 dn_rt_hash_mask = (1UL << order) * PAGE_SIZE /
1807 sizeof(struct dn_rt_hash_bucket);
1808 while(dn_rt_hash_mask & (dn_rt_hash_mask - 1))
1809 dn_rt_hash_mask--;
1810 dn_rt_hash_table = (struct dn_rt_hash_bucket *)
1811 __get_free_pages(GFP_ATOMIC, order);
1812 } while (dn_rt_hash_table == NULL && --order > 0);
1813
1814 if (!dn_rt_hash_table)
1815 panic("Failed to allocate DECnet route cache hash table\n");
1816
1817 printk(KERN_INFO
1818 "DECnet: Routing cache hash table of %u buckets, %ldKbytes\n",
1819 dn_rt_hash_mask,
1820 (long)(dn_rt_hash_mask*sizeof(struct dn_rt_hash_bucket))/1024);
1821
1822 dn_rt_hash_mask--;
1823 for(i = 0; i <= dn_rt_hash_mask; i++) {
1824 spin_lock_init(&dn_rt_hash_table[i].lock);
1825 dn_rt_hash_table[i].chain = NULL;
1826 }
1827
1828 dn_dst_ops.gc_thresh = (dn_rt_hash_mask + 1);
1829
1830 proc_net_fops_create("decnet_cache", S_IRUGO, &dn_rt_cache_seq_fops);
1831 }
1832
1833 void __exit dn_route_cleanup(void)
1834 {
1835 del_timer(&dn_route_timer);
1836 dn_run_flush(0);
1837
1838 proc_net_remove("decnet_cache");
1839 }
1840
Linux kernel - Deliverables
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