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[hh.org.git] / net / decnet / dn_route.c
blob9881933167bd8e9ae497a60b8615a2118b0674da
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/fib_rules.h>
84 #include <net/dn.h>
85 #include <net/dn_dev.h>
86 #include <net/dn_nsp.h>
87 #include <net/dn_route.h>
88 #include <net/dn_neigh.h>
89 #include <net/dn_fib.h>
90
91 struct dn_rt_hash_bucket
92 {
93 struct dn_route *chain;
94 spinlock_t lock;
95 } __attribute__((__aligned__(8)));
96
97 extern struct neigh_table dn_neigh_table;
98
99
100 static unsigned char dn_hiord_addr[6] = {0xAA,0x00,0x04,0x00,0x00,0x00};
101
102 static const int dn_rt_min_delay = 2 * HZ;
103 static const int dn_rt_max_delay = 10 * HZ;
104 static const int dn_rt_mtu_expires = 10 * 60 * HZ;
105
106 static unsigned long dn_rt_deadline;
107
108 static int dn_dst_gc(void);
109 static struct dst_entry *dn_dst_check(struct dst_entry *, __u32);
110 static struct dst_entry *dn_dst_negative_advice(struct dst_entry *);
111 static void dn_dst_link_failure(struct sk_buff *);
112 static void dn_dst_update_pmtu(struct dst_entry *dst, u32 mtu);
113 static int dn_route_input(struct sk_buff *);
114 static void dn_run_flush(unsigned long dummy);
115
116 static struct dn_rt_hash_bucket *dn_rt_hash_table;
117 static unsigned dn_rt_hash_mask;
118
119 static struct timer_list dn_route_timer;
120 static DEFINE_TIMER(dn_rt_flush_timer, dn_run_flush, 0, 0);
121 int decnet_dst_gc_interval = 2;
122
123 static struct dst_ops dn_dst_ops = {
124 .family = PF_DECnet,
125 .protocol = __constant_htons(ETH_P_DNA_RT),
126 .gc_thresh = 128,
127 .gc = dn_dst_gc,
128 .check = dn_dst_check,
129 .negative_advice = dn_dst_negative_advice,
130 .link_failure = dn_dst_link_failure,
131 .update_pmtu = dn_dst_update_pmtu,
132 .entry_size = sizeof(struct dn_route),
133 .entries = ATOMIC_INIT(0),
134 };
135
136 static __inline__ unsigned dn_hash(__le16 src, __le16 dst)
137 {
138 __u16 tmp = (__u16 __force)(src ^ dst);
139 tmp ^= (tmp >> 3);
140 tmp ^= (tmp >> 5);
141 tmp ^= (tmp >> 10);
142 return dn_rt_hash_mask & (unsigned)tmp;
143 }
144
145 static inline void dnrt_free(struct dn_route *rt)
146 {
147 call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free);
148 }
149
150 static inline void dnrt_drop(struct dn_route *rt)
151 {
152 dst_release(&rt->u.dst);
153 call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free);
154 }
155
156 static void dn_dst_check_expire(unsigned long dummy)
157 {
158 int i;
159 struct dn_route *rt, **rtp;
160 unsigned long now = jiffies;
161 unsigned long expire = 120 * HZ;
162
163 for(i = 0; i <= dn_rt_hash_mask; i++) {
164 rtp = &dn_rt_hash_table[i].chain;
165
166 spin_lock(&dn_rt_hash_table[i].lock);
167 while((rt=*rtp) != NULL) {
168 if (atomic_read(&rt->u.dst.__refcnt) ||
169 (now - rt->u.dst.lastuse) < expire) {
170 rtp = &rt->u.rt_next;
171 continue;
172 }
173 *rtp = rt->u.rt_next;
174 rt->u.rt_next = NULL;
175 dnrt_free(rt);
176 }
177 spin_unlock(&dn_rt_hash_table[i].lock);
178
179 if ((jiffies - now) > 0)
180 break;
181 }
182
183 mod_timer(&dn_route_timer, now + decnet_dst_gc_interval * HZ);
184 }
185
186 static int dn_dst_gc(void)
187 {
188 struct dn_route *rt, **rtp;
189 int i;
190 unsigned long now = jiffies;
191 unsigned long expire = 10 * HZ;
192
193 for(i = 0; i <= dn_rt_hash_mask; i++) {
194
195 spin_lock_bh(&dn_rt_hash_table[i].lock);
196 rtp = &dn_rt_hash_table[i].chain;
197
198 while((rt=*rtp) != NULL) {
199 if (atomic_read(&rt->u.dst.__refcnt) ||
200 (now - rt->u.dst.lastuse) < expire) {
201 rtp = &rt->u.rt_next;
202 continue;
203 }
204 *rtp = rt->u.rt_next;
205 rt->u.rt_next = NULL;
206 dnrt_drop(rt);
207 break;
208 }
209 spin_unlock_bh(&dn_rt_hash_table[i].lock);
210 }
211
212 return 0;
213 }
214
215 /*
216 * The decnet standards don't impose a particular minimum mtu, what they
217 * do insist on is that the routing layer accepts a datagram of at least
218 * 230 bytes long. Here we have to subtract the routing header length from
219 * 230 to get the minimum acceptable mtu. If there is no neighbour, then we
220 * assume the worst and use a long header size.
221 *
222 * We update both the mtu and the advertised mss (i.e. the segment size we
223 * advertise to the other end).
224 */
225 static void dn_dst_update_pmtu(struct dst_entry *dst, u32 mtu)
226 {
227 u32 min_mtu = 230;
228 struct dn_dev *dn = dst->neighbour ?
229 (struct dn_dev *)dst->neighbour->dev->dn_ptr : NULL;
230
231 if (dn && dn->use_long == 0)
232 min_mtu -= 6;
233 else
234 min_mtu -= 21;
235
236 if (dst->metrics[RTAX_MTU-1] > mtu && mtu >= min_mtu) {
237 if (!(dst_metric_locked(dst, RTAX_MTU))) {
238 dst->metrics[RTAX_MTU-1] = mtu;
239 dst_set_expires(dst, dn_rt_mtu_expires);
240 }
241 if (!(dst_metric_locked(dst, RTAX_ADVMSS))) {
242 u32 mss = mtu - DN_MAX_NSP_DATA_HEADER;
243 if (dst->metrics[RTAX_ADVMSS-1] > mss)
244 dst->metrics[RTAX_ADVMSS-1] = mss;
245 }
246 }
247 }
248
249 /*
250 * When a route has been marked obsolete. (e.g. routing cache flush)
251 */
252 static struct dst_entry *dn_dst_check(struct dst_entry *dst, __u32 cookie)
253 {
254 return NULL;
255 }
256
257 static struct dst_entry *dn_dst_negative_advice(struct dst_entry *dst)
258 {
259 dst_release(dst);
260 return NULL;
261 }
262
263 static void dn_dst_link_failure(struct sk_buff *skb)
264 {
265 return;
266 }
267
268 static inline int compare_keys(struct flowi *fl1, struct flowi *fl2)
269 {
270 return ((fl1->nl_u.dn_u.daddr ^ fl2->nl_u.dn_u.daddr) |
271 (fl1->nl_u.dn_u.saddr ^ fl2->nl_u.dn_u.saddr) |
272 (fl1->mark ^ fl2->mark) |
273 (fl1->nl_u.dn_u.scope ^ fl2->nl_u.dn_u.scope) |
274 (fl1->oif ^ fl2->oif) |
275 (fl1->iif ^ fl2->iif)) == 0;
276 }
277
278 static int dn_insert_route(struct dn_route *rt, unsigned hash, struct dn_route **rp)
279 {
280 struct dn_route *rth, **rthp;
281 unsigned long now = jiffies;
282
283 rthp = &dn_rt_hash_table[hash].chain;
284
285 spin_lock_bh(&dn_rt_hash_table[hash].lock);
286 while((rth = *rthp) != NULL) {
287 if (compare_keys(&rth->fl, &rt->fl)) {
288 /* Put it first */
289 *rthp = rth->u.rt_next;
290 rcu_assign_pointer(rth->u.rt_next,
291 dn_rt_hash_table[hash].chain);
292 rcu_assign_pointer(dn_rt_hash_table[hash].chain, rth);
293
294 rth->u.dst.__use++;
295 dst_hold(&rth->u.dst);
296 rth->u.dst.lastuse = now;
297 spin_unlock_bh(&dn_rt_hash_table[hash].lock);
298
299 dnrt_drop(rt);
300 *rp = rth;
301 return 0;
302 }
303 rthp = &rth->u.rt_next;
304 }
305
306 rcu_assign_pointer(rt->u.rt_next, dn_rt_hash_table[hash].chain);
307 rcu_assign_pointer(dn_rt_hash_table[hash].chain, rt);
308
309 dst_hold(&rt->u.dst);
310 rt->u.dst.__use++;
311 rt->u.dst.lastuse = now;
312 spin_unlock_bh(&dn_rt_hash_table[hash].lock);
313 *rp = rt;
314 return 0;
315 }
316
317 void dn_run_flush(unsigned long dummy)
318 {
319 int i;
320 struct dn_route *rt, *next;
321
322 for(i = 0; i < dn_rt_hash_mask; i++) {
323 spin_lock_bh(&dn_rt_hash_table[i].lock);
324
325 if ((rt = xchg(&dn_rt_hash_table[i].chain, NULL)) == NULL)
326 goto nothing_to_declare;
327
328 for(; rt; rt=next) {
329 next = rt->u.rt_next;
330 rt->u.rt_next = NULL;
331 dst_free((struct dst_entry *)rt);
332 }
333
334 nothing_to_declare:
335 spin_unlock_bh(&dn_rt_hash_table[i].lock);
336 }
337 }
338
339 static DEFINE_SPINLOCK(dn_rt_flush_lock);
340
341 void dn_rt_cache_flush(int delay)
342 {
343 unsigned long now = jiffies;
344 int user_mode = !in_interrupt();
345
346 if (delay < 0)
347 delay = dn_rt_min_delay;
348
349 spin_lock_bh(&dn_rt_flush_lock);
350
351 if (del_timer(&dn_rt_flush_timer) && delay > 0 && dn_rt_deadline) {
352 long tmo = (long)(dn_rt_deadline - now);
353
354 if (user_mode && tmo < dn_rt_max_delay - dn_rt_min_delay)
355 tmo = 0;
356
357 if (delay > tmo)
358 delay = tmo;
359 }
360
361 if (delay <= 0) {
362 spin_unlock_bh(&dn_rt_flush_lock);
363 dn_run_flush(0);
364 return;
365 }
366
367 if (dn_rt_deadline == 0)
368 dn_rt_deadline = now + dn_rt_max_delay;
369
370 dn_rt_flush_timer.expires = now + delay;
371 add_timer(&dn_rt_flush_timer);
372 spin_unlock_bh(&dn_rt_flush_lock);
373 }
374
375 /**
376 * dn_return_short - Return a short packet to its sender
377 * @skb: The packet to return
378 *
379 */
380 static int dn_return_short(struct sk_buff *skb)
381 {
382 struct dn_skb_cb *cb;
383 unsigned char *ptr;
384 __le16 *src;
385 __le16 *dst;
386 __le16 tmp;
387
388 /* Add back headers */
389 skb_push(skb, skb->data - skb->nh.raw);
390
391 if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
392 return NET_RX_DROP;
393
394 cb = DN_SKB_CB(skb);
395 /* Skip packet length and point to flags */
396 ptr = skb->data + 2;
397 *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
398
399 dst = (__le16 *)ptr;
400 ptr += 2;
401 src = (__le16 *)ptr;
402 ptr += 2;
403 *ptr = 0; /* Zero hop count */
404
405 /* Swap source and destination */
406 tmp = *src;
407 *src = *dst;
408 *dst = tmp;
409
410 skb->pkt_type = PACKET_OUTGOING;
411 dn_rt_finish_output(skb, NULL, NULL);
412 return NET_RX_SUCCESS;
413 }
414
415 /**
416 * dn_return_long - Return a long packet to its sender
417 * @skb: The long format packet to return
418 *
419 */
420 static int dn_return_long(struct sk_buff *skb)
421 {
422 struct dn_skb_cb *cb;
423 unsigned char *ptr;
424 unsigned char *src_addr, *dst_addr;
425 unsigned char tmp[ETH_ALEN];
426
427 /* Add back all headers */
428 skb_push(skb, skb->data - skb->nh.raw);
429
430 if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
431 return NET_RX_DROP;
432
433 cb = DN_SKB_CB(skb);
434 /* Ignore packet length and point to flags */
435 ptr = skb->data + 2;
436
437 /* Skip padding */
438 if (*ptr & DN_RT_F_PF) {
439 char padlen = (*ptr & ~DN_RT_F_PF);
440 ptr += padlen;
441 }
442
443 *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
444 ptr += 2;
445 dst_addr = ptr;
446 ptr += 8;
447 src_addr = ptr;
448 ptr += 6;
449 *ptr = 0; /* Zero hop count */
450
451 /* Swap source and destination */
452 memcpy(tmp, src_addr, ETH_ALEN);
453 memcpy(src_addr, dst_addr, ETH_ALEN);
454 memcpy(dst_addr, tmp, ETH_ALEN);
455
456 skb->pkt_type = PACKET_OUTGOING;
457 dn_rt_finish_output(skb, dst_addr, src_addr);
458 return NET_RX_SUCCESS;
459 }
460
461 /**
462 * dn_route_rx_packet - Try and find a route for an incoming packet
463 * @skb: The packet to find a route for
464 *
465 * Returns: result of input function if route is found, error code otherwise
466 */
467 static int dn_route_rx_packet(struct sk_buff *skb)
468 {
469 struct dn_skb_cb *cb = DN_SKB_CB(skb);
470 int err;
471
472 if ((err = dn_route_input(skb)) == 0)
473 return dst_input(skb);
474
475 if (decnet_debug_level & 4) {
476 char *devname = skb->dev ? skb->dev->name : "???";
477 struct dn_skb_cb *cb = DN_SKB_CB(skb);
478 printk(KERN_DEBUG
479 "DECnet: dn_route_rx_packet: rt_flags=0x%02x dev=%s len=%d src=0x%04hx dst=0x%04hx err=%d type=%d\n",
480 (int)cb->rt_flags, devname, skb->len,
481 dn_ntohs(cb->src), dn_ntohs(cb->dst),
482 err, skb->pkt_type);
483 }
484
485 if ((skb->pkt_type == PACKET_HOST) && (cb->rt_flags & DN_RT_F_RQR)) {
486 switch(cb->rt_flags & DN_RT_PKT_MSK) {
487 case DN_RT_PKT_SHORT:
488 return dn_return_short(skb);
489 case DN_RT_PKT_LONG:
490 return dn_return_long(skb);
491 }
492 }
493
494 kfree_skb(skb);
495 return NET_RX_DROP;
496 }
497
498 static int dn_route_rx_long(struct sk_buff *skb)
499 {
500 struct dn_skb_cb *cb = DN_SKB_CB(skb);
501 unsigned char *ptr = skb->data;
502
503 if (!pskb_may_pull(skb, 21)) /* 20 for long header, 1 for shortest nsp */
504 goto drop_it;
505
506 skb_pull(skb, 20);
507 skb->h.raw = skb->data;
508
509 /* Destination info */
510 ptr += 2;
511 cb->dst = dn_eth2dn(ptr);
512 if (memcmp(ptr, dn_hiord_addr, 4) != 0)
513 goto drop_it;
514 ptr += 6;
515
516
517 /* Source info */
518 ptr += 2;
519 cb->src = dn_eth2dn(ptr);
520 if (memcmp(ptr, dn_hiord_addr, 4) != 0)
521 goto drop_it;
522 ptr += 6;
523 /* Other junk */
524 ptr++;
525 cb->hops = *ptr++; /* Visit Count */
526
527 return NF_HOOK(PF_DECnet, NF_DN_PRE_ROUTING, skb, skb->dev, NULL, dn_route_rx_packet);
528
529 drop_it:
530 kfree_skb(skb);
531 return NET_RX_DROP;
532 }
533
534
535
536 static int dn_route_rx_short(struct sk_buff *skb)
537 {
538 struct dn_skb_cb *cb = DN_SKB_CB(skb);
539 unsigned char *ptr = skb->data;
540
541 if (!pskb_may_pull(skb, 6)) /* 5 for short header + 1 for shortest nsp */
542 goto drop_it;
543
544 skb_pull(skb, 5);
545 skb->h.raw = skb->data;
546
547 cb->dst = *(__le16 *)ptr;
548 ptr += 2;
549 cb->src = *(__le16 *)ptr;
550 ptr += 2;
551 cb->hops = *ptr & 0x3f;
552
553 return NF_HOOK(PF_DECnet, NF_DN_PRE_ROUTING, skb, skb->dev, NULL, dn_route_rx_packet);
554
555 drop_it:
556 kfree_skb(skb);
557 return NET_RX_DROP;
558 }
559
560 static int dn_route_discard(struct sk_buff *skb)
561 {
562 /*
563 * I know we drop the packet here, but thats considered success in
564 * this case
565 */
566 kfree_skb(skb);
567 return NET_RX_SUCCESS;
568 }
569
570 static int dn_route_ptp_hello(struct sk_buff *skb)
571 {
572 dn_dev_hello(skb);
573 dn_neigh_pointopoint_hello(skb);
574 return NET_RX_SUCCESS;
575 }
576
577 int dn_route_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
578 {
579 struct dn_skb_cb *cb;
580 unsigned char flags = 0;
581 __u16 len = dn_ntohs(*(__le16 *)skb->data);
582 struct dn_dev *dn = (struct dn_dev *)dev->dn_ptr;
583 unsigned char padlen = 0;
584
585 if (dn == NULL)
586 goto dump_it;
587
588 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
589 goto out;
590
591 if (!pskb_may_pull(skb, 3))
592 goto dump_it;
593
594 skb_pull(skb, 2);
595
596 if (len > skb->len)
597 goto dump_it;
598
599 skb_trim(skb, len);
600
601 flags = *skb->data;
602
603 cb = DN_SKB_CB(skb);
604 cb->stamp = jiffies;
605 cb->iif = dev->ifindex;
606
607 /*
608 * If we have padding, remove it.
609 */
610 if (flags & DN_RT_F_PF) {
611 padlen = flags & ~DN_RT_F_PF;
612 if (!pskb_may_pull(skb, padlen + 1))
613 goto dump_it;
614 skb_pull(skb, padlen);
615 flags = *skb->data;
616 }
617
618 skb->nh.raw = skb->data;
619
620 /*
621 * Weed out future version DECnet
622 */
623 if (flags & DN_RT_F_VER)
624 goto dump_it;
625
626 cb->rt_flags = flags;
627
628 if (decnet_debug_level & 1)
629 printk(KERN_DEBUG
630 "dn_route_rcv: got 0x%02x from %s [%d %d %d]\n",
631 (int)flags, (dev) ? dev->name : "???", len, skb->len,
632 padlen);
633
634 if (flags & DN_RT_PKT_CNTL) {
635 if (unlikely(skb_linearize(skb)))
636 goto dump_it;
637
638 switch(flags & DN_RT_CNTL_MSK) {
639 case DN_RT_PKT_INIT:
640 dn_dev_init_pkt(skb);
641 break;
642 case DN_RT_PKT_VERI:
643 dn_dev_veri_pkt(skb);
644 break;
645 }
646
647 if (dn->parms.state != DN_DEV_S_RU)
648 goto dump_it;
649
650 switch(flags & DN_RT_CNTL_MSK) {
651 case DN_RT_PKT_HELO:
652 return NF_HOOK(PF_DECnet, NF_DN_HELLO, skb, skb->dev, NULL, dn_route_ptp_hello);
653
654 case DN_RT_PKT_L1RT:
655 case DN_RT_PKT_L2RT:
656 return NF_HOOK(PF_DECnet, NF_DN_ROUTE, skb, skb->dev, NULL, dn_route_discard);
657 case DN_RT_PKT_ERTH:
658 return NF_HOOK(PF_DECnet, NF_DN_HELLO, skb, skb->dev, NULL, dn_neigh_router_hello);
659
660 case DN_RT_PKT_EEDH:
661 return NF_HOOK(PF_DECnet, NF_DN_HELLO, skb, skb->dev, NULL, dn_neigh_endnode_hello);
662 }
663 } else {
664 if (dn->parms.state != DN_DEV_S_RU)
665 goto dump_it;
666
667 skb_pull(skb, 1); /* Pull flags */
668
669 switch(flags & DN_RT_PKT_MSK) {
670 case DN_RT_PKT_LONG:
671 return dn_route_rx_long(skb);
672 case DN_RT_PKT_SHORT:
673 return dn_route_rx_short(skb);
674 }
675 }
676
677 dump_it:
678 kfree_skb(skb);
679 out:
680 return NET_RX_DROP;
681 }
682
683 static int dn_output(struct sk_buff *skb)
684 {
685 struct dst_entry *dst = skb->dst;
686 struct dn_route *rt = (struct dn_route *)dst;
687 struct net_device *dev = dst->dev;
688 struct dn_skb_cb *cb = DN_SKB_CB(skb);
689 struct neighbour *neigh;
690
691 int err = -EINVAL;
692
693 if ((neigh = dst->neighbour) == NULL)
694 goto error;
695
696 skb->dev = dev;
697
698 cb->src = rt->rt_saddr;
699 cb->dst = rt->rt_daddr;
700
701 /*
702 * Always set the Intra-Ethernet bit on all outgoing packets
703 * originated on this node. Only valid flag from upper layers
704 * is return-to-sender-requested. Set hop count to 0 too.
705 */
706 cb->rt_flags &= ~DN_RT_F_RQR;
707 cb->rt_flags |= DN_RT_F_IE;
708 cb->hops = 0;
709
710 return NF_HOOK(PF_DECnet, NF_DN_LOCAL_OUT, skb, NULL, dev, neigh->output);
711
712 error:
713 if (net_ratelimit())
714 printk(KERN_DEBUG "dn_output: This should not happen\n");
715
716 kfree_skb(skb);
717
718 return err;
719 }
720
721 static int dn_forward(struct sk_buff *skb)
722 {
723 struct dn_skb_cb *cb = DN_SKB_CB(skb);
724 struct dst_entry *dst = skb->dst;
725 struct dn_dev *dn_db = dst->dev->dn_ptr;
726 struct dn_route *rt;
727 struct neighbour *neigh = dst->neighbour;
728 int header_len;
729 #ifdef CONFIG_NETFILTER
730 struct net_device *dev = skb->dev;
731 #endif
732
733 if (skb->pkt_type != PACKET_HOST)
734 goto drop;
735
736 /* Ensure that we have enough space for headers */
737 rt = (struct dn_route *)skb->dst;
738 header_len = dn_db->use_long ? 21 : 6;
739 if (skb_cow(skb, LL_RESERVED_SPACE(rt->u.dst.dev)+header_len))
740 goto drop;
741
742 /*
743 * Hop count exceeded.
744 */
745 if (++cb->hops > 30)
746 goto drop;
747
748 skb->dev = rt->u.dst.dev;
749
750 /*
751 * If packet goes out same interface it came in on, then set
752 * the Intra-Ethernet bit. This has no effect for short
753 * packets, so we don't need to test for them here.
754 */
755 cb->rt_flags &= ~DN_RT_F_IE;
756 if (rt->rt_flags & RTCF_DOREDIRECT)
757 cb->rt_flags |= DN_RT_F_IE;
758
759 return NF_HOOK(PF_DECnet, NF_DN_FORWARD, skb, dev, skb->dev, neigh->output);
760
761 drop:
762 kfree_skb(skb);
763 return NET_RX_DROP;
764 }
765
766 /*
767 * Drop packet. This is used for endnodes and for
768 * when we should not be forwarding packets from
769 * this dest.
770 */
771 static int dn_blackhole(struct sk_buff *skb)
772 {
773 kfree_skb(skb);
774 return NET_RX_DROP;
775 }
776
777 /*
778 * Used to catch bugs. This should never normally get
779 * called.
780 */
781 static int dn_rt_bug(struct sk_buff *skb)
782 {
783 if (net_ratelimit()) {
784 struct dn_skb_cb *cb = DN_SKB_CB(skb);
785
786 printk(KERN_DEBUG "dn_rt_bug: skb from:%04x to:%04x\n",
787 dn_ntohs(cb->src), dn_ntohs(cb->dst));
788 }
789
790 kfree_skb(skb);
791
792 return NET_RX_BAD;
793 }
794
795 static int dn_rt_set_next_hop(struct dn_route *rt, struct dn_fib_res *res)
796 {
797 struct dn_fib_info *fi = res->fi;
798 struct net_device *dev = rt->u.dst.dev;
799 struct neighbour *n;
800 unsigned mss;
801
802 if (fi) {
803 if (DN_FIB_RES_GW(*res) &&
804 DN_FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
805 rt->rt_gateway = DN_FIB_RES_GW(*res);
806 memcpy(rt->u.dst.metrics, fi->fib_metrics,
807 sizeof(rt->u.dst.metrics));
808 }
809 rt->rt_type = res->type;
810
811 if (dev != NULL && rt->u.dst.neighbour == NULL) {
812 n = __neigh_lookup_errno(&dn_neigh_table, &rt->rt_gateway, dev);
813 if (IS_ERR(n))
814 return PTR_ERR(n);
815 rt->u.dst.neighbour = n;
816 }
817
818 if (rt->u.dst.metrics[RTAX_MTU-1] == 0 ||
819 rt->u.dst.metrics[RTAX_MTU-1] > rt->u.dst.dev->mtu)
820 rt->u.dst.metrics[RTAX_MTU-1] = rt->u.dst.dev->mtu;
821 mss = dn_mss_from_pmtu(dev, dst_mtu(&rt->u.dst));
822 if (rt->u.dst.metrics[RTAX_ADVMSS-1] == 0 ||
823 rt->u.dst.metrics[RTAX_ADVMSS-1] > mss)
824 rt->u.dst.metrics[RTAX_ADVMSS-1] = mss;
825 return 0;
826 }
827
828 static inline int dn_match_addr(__le16 addr1, __le16 addr2)
829 {
830 __u16 tmp = dn_ntohs(addr1) ^ dn_ntohs(addr2);
831 int match = 16;
832 while(tmp) {
833 tmp >>= 1;
834 match--;
835 }
836 return match;
837 }
838
839 static __le16 dnet_select_source(const struct net_device *dev, __le16 daddr, int scope)
840 {
841 __le16 saddr = 0;
842 struct dn_dev *dn_db = dev->dn_ptr;
843 struct dn_ifaddr *ifa;
844 int best_match = 0;
845 int ret;
846
847 read_lock(&dev_base_lock);
848 for(ifa = dn_db->ifa_list; ifa; ifa = ifa->ifa_next) {
849 if (ifa->ifa_scope > scope)
850 continue;
851 if (!daddr) {
852 saddr = ifa->ifa_local;
853 break;
854 }
855 ret = dn_match_addr(daddr, ifa->ifa_local);
856 if (ret > best_match)
857 saddr = ifa->ifa_local;
858 if (best_match == 0)
859 saddr = ifa->ifa_local;
860 }
861 read_unlock(&dev_base_lock);
862
863 return saddr;
864 }
865
866 static inline __le16 __dn_fib_res_prefsrc(struct dn_fib_res *res)
867 {
868 return dnet_select_source(DN_FIB_RES_DEV(*res), DN_FIB_RES_GW(*res), res->scope);
869 }
870
871 static inline __le16 dn_fib_rules_map_destination(__le16 daddr, struct dn_fib_res *res)
872 {
873 __le16 mask = dnet_make_mask(res->prefixlen);
874 return (daddr&~mask)|res->fi->fib_nh->nh_gw;
875 }
876
877 static int dn_route_output_slow(struct dst_entry **pprt, const struct flowi *oldflp, int try_hard)
878 {
879 struct flowi fl = { .nl_u = { .dn_u =
880 { .daddr = oldflp->fld_dst,
881 .saddr = oldflp->fld_src,
882 .scope = RT_SCOPE_UNIVERSE,
883 } },
884 .mark = oldflp->mark,
885 .iif = loopback_dev.ifindex,
886 .oif = oldflp->oif };
887 struct dn_route *rt = NULL;
888 struct net_device *dev_out = NULL;
889 struct neighbour *neigh = NULL;
890 unsigned hash;
891 unsigned flags = 0;
892 struct dn_fib_res res = { .fi = NULL, .type = RTN_UNICAST };
893 int err;
894 int free_res = 0;
895 __le16 gateway = 0;
896
897 if (decnet_debug_level & 16)
898 printk(KERN_DEBUG
899 "dn_route_output_slow: dst=%04x src=%04x mark=%d"
900 " iif=%d oif=%d\n", dn_ntohs(oldflp->fld_dst),
901 dn_ntohs(oldflp->fld_src),
902 oldflp->mark, loopback_dev.ifindex, oldflp->oif);
903
904 /* If we have an output interface, verify its a DECnet device */
905 if (oldflp->oif) {
906 dev_out = dev_get_by_index(oldflp->oif);
907 err = -ENODEV;
908 if (dev_out && dev_out->dn_ptr == NULL) {
909 dev_put(dev_out);
910 dev_out = NULL;
911 }
912 if (dev_out == NULL)
913 goto out;
914 }
915
916 /* If we have a source address, verify that its a local address */
917 if (oldflp->fld_src) {
918 err = -EADDRNOTAVAIL;
919
920 if (dev_out) {
921 if (dn_dev_islocal(dev_out, oldflp->fld_src))
922 goto source_ok;
923 dev_put(dev_out);
924 goto out;
925 }
926 read_lock(&dev_base_lock);
927 for(dev_out = dev_base; dev_out; dev_out = dev_out->next) {
928 if (!dev_out->dn_ptr)
929 continue;
930 if (!dn_dev_islocal(dev_out, oldflp->fld_src))
931 continue;
932 if ((dev_out->flags & IFF_LOOPBACK) &&
933 oldflp->fld_dst &&
934 !dn_dev_islocal(dev_out, oldflp->fld_dst))
935 continue;
936 break;
937 }
938 read_unlock(&dev_base_lock);
939 if (dev_out == NULL)
940 goto out;
941 dev_hold(dev_out);
942 source_ok:
943 ;
944 }
945
946 /* No destination? Assume its local */
947 if (!fl.fld_dst) {
948 fl.fld_dst = fl.fld_src;
949
950 err = -EADDRNOTAVAIL;
951 if (dev_out)
952 dev_put(dev_out);
953 dev_out = &loopback_dev;
954 dev_hold(dev_out);
955 if (!fl.fld_dst) {
956 fl.fld_dst =
957 fl.fld_src = dnet_select_source(dev_out, 0,
958 RT_SCOPE_HOST);
959 if (!fl.fld_dst)
960 goto out;
961 }
962 fl.oif = loopback_dev.ifindex;
963 res.type = RTN_LOCAL;
964 goto make_route;
965 }
966
967 if (decnet_debug_level & 16)
968 printk(KERN_DEBUG
969 "dn_route_output_slow: initial checks complete."
970 " dst=%o4x src=%04x oif=%d try_hard=%d\n",
971 dn_ntohs(fl.fld_dst), dn_ntohs(fl.fld_src),
972 fl.oif, try_hard);
973
974 /*
975 * N.B. If the kernel is compiled without router support then
976 * dn_fib_lookup() will evaluate to non-zero so this if () block
977 * will always be executed.
978 */
979 err = -ESRCH;
980 if (try_hard || (err = dn_fib_lookup(&fl, &res)) != 0) {
981 struct dn_dev *dn_db;
982 if (err != -ESRCH)
983 goto out;
984 /*
985 * Here the fallback is basically the standard algorithm for
986 * routing in endnodes which is described in the DECnet routing
987 * docs
988 *
989 * If we are not trying hard, look in neighbour cache.
990 * The result is tested to ensure that if a specific output
991 * device/source address was requested, then we honour that
992 * here
993 */
994 if (!try_hard) {
995 neigh = neigh_lookup_nodev(&dn_neigh_table, &fl.fld_dst);
996 if (neigh) {
997 if ((oldflp->oif &&
998 (neigh->dev->ifindex != oldflp->oif)) ||
999 (oldflp->fld_src &&
1000 (!dn_dev_islocal(neigh->dev,
1001 oldflp->fld_src)))) {
1002 neigh_release(neigh);
1003 neigh = NULL;
1004 } else {
1005 if (dev_out)
1006 dev_put(dev_out);
1007 if (dn_dev_islocal(neigh->dev, fl.fld_dst)) {
1008 dev_out = &loopback_dev;
1009 res.type = RTN_LOCAL;
1010 } else {
1011 dev_out = neigh->dev;
1012 }
1013 dev_hold(dev_out);
1014 goto select_source;
1015 }
1016 }
1017 }
1018
1019 /* Not there? Perhaps its a local address */
1020 if (dev_out == NULL)
1021 dev_out = dn_dev_get_default();
1022 err = -ENODEV;
1023 if (dev_out == NULL)
1024 goto out;
1025 dn_db = dev_out->dn_ptr;
1026 /* Possible improvement - check all devices for local addr */
1027 if (dn_dev_islocal(dev_out, fl.fld_dst)) {
1028 dev_put(dev_out);
1029 dev_out = &loopback_dev;
1030 dev_hold(dev_out);
1031 res.type = RTN_LOCAL;
1032 goto select_source;
1033 }
1034 /* Not local either.... try sending it to the default router */
1035 neigh = neigh_clone(dn_db->router);
1036 BUG_ON(neigh && neigh->dev != dev_out);
1037
1038 /* Ok then, we assume its directly connected and move on */
1039 select_source:
1040 if (neigh)
1041 gateway = ((struct dn_neigh *)neigh)->addr;
1042 if (gateway == 0)
1043 gateway = fl.fld_dst;
1044 if (fl.fld_src == 0) {
1045 fl.fld_src = dnet_select_source(dev_out, gateway,
1046 res.type == RTN_LOCAL ?
1047 RT_SCOPE_HOST :
1048 RT_SCOPE_LINK);
1049 if (fl.fld_src == 0 && res.type != RTN_LOCAL)
1050 goto e_addr;
1051 }
1052 fl.oif = dev_out->ifindex;
1053 goto make_route;
1054 }
1055 free_res = 1;
1056
1057 if (res.type == RTN_NAT)
1058 goto e_inval;
1059
1060 if (res.type == RTN_LOCAL) {
1061 if (!fl.fld_src)
1062 fl.fld_src = fl.fld_dst;
1063 if (dev_out)
1064 dev_put(dev_out);
1065 dev_out = &loopback_dev;
1066 dev_hold(dev_out);
1067 fl.oif = dev_out->ifindex;
1068 if (res.fi)
1069 dn_fib_info_put(res.fi);
1070 res.fi = NULL;
1071 goto make_route;
1072 }
1073
1074 if (res.fi->fib_nhs > 1 && fl.oif == 0)
1075 dn_fib_select_multipath(&fl, &res);
1076
1077 /*
1078 * We could add some logic to deal with default routes here and
1079 * get rid of some of the special casing above.
1080 */
1081
1082 if (!fl.fld_src)
1083 fl.fld_src = DN_FIB_RES_PREFSRC(res);
1084
1085 if (dev_out)
1086 dev_put(dev_out);
1087 dev_out = DN_FIB_RES_DEV(res);
1088 dev_hold(dev_out);
1089 fl.oif = dev_out->ifindex;
1090 gateway = DN_FIB_RES_GW(res);
1091
1092 make_route:
1093 if (dev_out->flags & IFF_LOOPBACK)
1094 flags |= RTCF_LOCAL;
1095
1096 rt = dst_alloc(&dn_dst_ops);
1097 if (rt == NULL)
1098 goto e_nobufs;
1099
1100 atomic_set(&rt->u.dst.__refcnt, 1);
1101 rt->u.dst.flags = DST_HOST;
1102
1103 rt->fl.fld_src = oldflp->fld_src;
1104 rt->fl.fld_dst = oldflp->fld_dst;
1105 rt->fl.oif = oldflp->oif;
1106 rt->fl.iif = 0;
1107 rt->fl.mark = oldflp->mark;
1108
1109 rt->rt_saddr = fl.fld_src;
1110 rt->rt_daddr = fl.fld_dst;
1111 rt->rt_gateway = gateway ? gateway : fl.fld_dst;
1112 rt->rt_local_src = fl.fld_src;
1113
1114 rt->rt_dst_map = fl.fld_dst;
1115 rt->rt_src_map = fl.fld_src;
1116
1117 rt->u.dst.dev = dev_out;
1118 dev_hold(dev_out);
1119 rt->u.dst.neighbour = neigh;
1120 neigh = NULL;
1121
1122 rt->u.dst.lastuse = jiffies;
1123 rt->u.dst.output = dn_output;
1124 rt->u.dst.input = dn_rt_bug;
1125 rt->rt_flags = flags;
1126 if (flags & RTCF_LOCAL)
1127 rt->u.dst.input = dn_nsp_rx;
1128
1129 err = dn_rt_set_next_hop(rt, &res);
1130 if (err)
1131 goto e_neighbour;
1132
1133 hash = dn_hash(rt->fl.fld_src, rt->fl.fld_dst);
1134 dn_insert_route(rt, hash, (struct dn_route **)pprt);
1135
1136 done:
1137 if (neigh)
1138 neigh_release(neigh);
1139 if (free_res)
1140 dn_fib_res_put(&res);
1141 if (dev_out)
1142 dev_put(dev_out);
1143 out:
1144 return err;
1145
1146 e_addr:
1147 err = -EADDRNOTAVAIL;
1148 goto done;
1149 e_inval:
1150 err = -EINVAL;
1151 goto done;
1152 e_nobufs:
1153 err = -ENOBUFS;
1154 goto done;
1155 e_neighbour:
1156 dst_free(&rt->u.dst);
1157 goto e_nobufs;
1158 }
1159
1160
1161 /*
1162 * N.B. The flags may be moved into the flowi at some future stage.
1163 */
1164 static int __dn_route_output_key(struct dst_entry **pprt, const struct flowi *flp, int flags)
1165 {
1166 unsigned hash = dn_hash(flp->fld_src, flp->fld_dst);
1167 struct dn_route *rt = NULL;
1168
1169 if (!(flags & MSG_TRYHARD)) {
1170 rcu_read_lock_bh();
1171 for(rt = rcu_dereference(dn_rt_hash_table[hash].chain); rt;
1172 rt = rcu_dereference(rt->u.rt_next)) {
1173 if ((flp->fld_dst == rt->fl.fld_dst) &&
1174 (flp->fld_src == rt->fl.fld_src) &&
1175 (flp->mark == rt->fl.mark) &&
1176 (rt->fl.iif == 0) &&
1177 (rt->fl.oif == flp->oif)) {
1178 rt->u.dst.lastuse = jiffies;
1179 dst_hold(&rt->u.dst);
1180 rt->u.dst.__use++;
1181 rcu_read_unlock_bh();
1182 *pprt = &rt->u.dst;
1183 return 0;
1184 }
1185 }
1186 rcu_read_unlock_bh();
1187 }
1188
1189 return dn_route_output_slow(pprt, flp, flags);
1190 }
1191
1192 static int dn_route_output_key(struct dst_entry **pprt, struct flowi *flp, int flags)
1193 {
1194 int err;
1195
1196 err = __dn_route_output_key(pprt, flp, flags);
1197 if (err == 0 && flp->proto) {
1198 err = xfrm_lookup(pprt, flp, NULL, 0);
1199 }
1200 return err;
1201 }
1202
1203 int dn_route_output_sock(struct dst_entry **pprt, struct flowi *fl, struct sock *sk, int flags)
1204 {
1205 int err;
1206
1207 err = __dn_route_output_key(pprt, fl, flags & MSG_TRYHARD);
1208 if (err == 0 && fl->proto) {
1209 err = xfrm_lookup(pprt, fl, sk, !(flags & MSG_DONTWAIT));
1210 }
1211 return err;
1212 }
1213
1214 static int dn_route_input_slow(struct sk_buff *skb)
1215 {
1216 struct dn_route *rt = NULL;
1217 struct dn_skb_cb *cb = DN_SKB_CB(skb);
1218 struct net_device *in_dev = skb->dev;
1219 struct net_device *out_dev = NULL;
1220 struct dn_dev *dn_db;
1221 struct neighbour *neigh = NULL;
1222 unsigned hash;
1223 int flags = 0;
1224 __le16 gateway = 0;
1225 __le16 local_src = 0;
1226 struct flowi fl = { .nl_u = { .dn_u =
1227 { .daddr = cb->dst,
1228 .saddr = cb->src,
1229 .scope = RT_SCOPE_UNIVERSE,
1230 } },
1231 .mark = skb->mark,
1232 .iif = skb->dev->ifindex };
1233 struct dn_fib_res res = { .fi = NULL, .type = RTN_UNREACHABLE };
1234 int err = -EINVAL;
1235 int free_res = 0;
1236
1237 dev_hold(in_dev);
1238
1239 if ((dn_db = in_dev->dn_ptr) == NULL)
1240 goto out;
1241
1242 /* Zero source addresses are not allowed */
1243 if (fl.fld_src == 0)
1244 goto out;
1245
1246 /*
1247 * In this case we've just received a packet from a source
1248 * outside ourselves pretending to come from us. We don't
1249 * allow it any further to prevent routing loops, spoofing and
1250 * other nasties. Loopback packets already have the dst attached
1251 * so this only affects packets which have originated elsewhere.
1252 */
1253 err = -ENOTUNIQ;
1254 if (dn_dev_islocal(in_dev, cb->src))
1255 goto out;
1256
1257 err = dn_fib_lookup(&fl, &res);
1258 if (err) {
1259 if (err != -ESRCH)
1260 goto out;
1261 /*
1262 * Is the destination us ?
1263 */
1264 if (!dn_dev_islocal(in_dev, cb->dst))
1265 goto e_inval;
1266
1267 res.type = RTN_LOCAL;
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 = fl.fld_src; /* no NAT support for now */
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.mark = fl.mark;
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 (rt->fl.mark == skb->mark) &&
1451 (rt->fl.iif == cb->iif)) {
1452 rt->u.dst.lastuse = jiffies;
1453 dst_hold(&rt->u.dst);
1454 rt->u.dst.__use++;
1455 rcu_read_unlock();
1456 skb->dst = (struct dst_entry *)rt;
1457 return 0;
1458 }
1459 }
1460 rcu_read_unlock();
1461
1462 return dn_route_input_slow(skb);
1463 }
1464
1465 static int dn_rt_fill_info(struct sk_buff *skb, u32 pid, u32 seq,
1466 int event, int nowait, unsigned int flags)
1467 {
1468 struct dn_route *rt = (struct dn_route *)skb->dst;
1469 struct rtmsg *r;
1470 struct nlmsghdr *nlh;
1471 unsigned char *b = skb->tail;
1472 long expires;
1473
1474 nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*r), flags);
1475 r = NLMSG_DATA(nlh);
1476 r->rtm_family = AF_DECnet;
1477 r->rtm_dst_len = 16;
1478 r->rtm_src_len = 0;
1479 r->rtm_tos = 0;
1480 r->rtm_table = RT_TABLE_MAIN;
1481 RTA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
1482 r->rtm_type = rt->rt_type;
1483 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
1484 r->rtm_scope = RT_SCOPE_UNIVERSE;
1485 r->rtm_protocol = RTPROT_UNSPEC;
1486 if (rt->rt_flags & RTCF_NOTIFY)
1487 r->rtm_flags |= RTM_F_NOTIFY;
1488 RTA_PUT(skb, RTA_DST, 2, &rt->rt_daddr);
1489 if (rt->fl.fld_src) {
1490 r->rtm_src_len = 16;
1491 RTA_PUT(skb, RTA_SRC, 2, &rt->fl.fld_src);
1492 }
1493 if (rt->u.dst.dev)
1494 RTA_PUT(skb, RTA_OIF, sizeof(int), &rt->u.dst.dev->ifindex);
1495 /*
1496 * Note to self - change this if input routes reverse direction when
1497 * they deal only with inputs and not with replies like they do
1498 * currently.
1499 */
1500 RTA_PUT(skb, RTA_PREFSRC, 2, &rt->rt_local_src);
1501 if (rt->rt_daddr != rt->rt_gateway)
1502 RTA_PUT(skb, RTA_GATEWAY, 2, &rt->rt_gateway);
1503 if (rtnetlink_put_metrics(skb, rt->u.dst.metrics) < 0)
1504 goto rtattr_failure;
1505 expires = rt->u.dst.expires ? rt->u.dst.expires - jiffies : 0;
1506 if (rtnl_put_cacheinfo(skb, &rt->u.dst, 0, 0, 0, expires,
1507 rt->u.dst.error) < 0)
1508 goto rtattr_failure;
1509 if (rt->fl.iif)
1510 RTA_PUT(skb, RTA_IIF, sizeof(int), &rt->fl.iif);
1511
1512 nlh->nlmsg_len = skb->tail - b;
1513 return skb->len;
1514
1515 nlmsg_failure:
1516 rtattr_failure:
1517 skb_trim(skb, b - skb->data);
1518 return -1;
1519 }
1520
1521 /*
1522 * This is called by both endnodes and routers now.
1523 */
1524 int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, void *arg)
1525 {
1526 struct rtattr **rta = arg;
1527 struct rtmsg *rtm = NLMSG_DATA(nlh);
1528 struct dn_route *rt = NULL;
1529 struct dn_skb_cb *cb;
1530 int err;
1531 struct sk_buff *skb;
1532 struct flowi fl;
1533
1534 memset(&fl, 0, sizeof(fl));
1535 fl.proto = DNPROTO_NSP;
1536
1537 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1538 if (skb == NULL)
1539 return -ENOBUFS;
1540 skb->mac.raw = skb->data;
1541 cb = DN_SKB_CB(skb);
1542
1543 if (rta[RTA_SRC-1])
1544 memcpy(&fl.fld_src, RTA_DATA(rta[RTA_SRC-1]), 2);
1545 if (rta[RTA_DST-1])
1546 memcpy(&fl.fld_dst, RTA_DATA(rta[RTA_DST-1]), 2);
1547 if (rta[RTA_IIF-1])
1548 memcpy(&fl.iif, RTA_DATA(rta[RTA_IIF-1]), sizeof(int));
1549
1550 if (fl.iif) {
1551 struct net_device *dev;
1552 if ((dev = dev_get_by_index(fl.iif)) == NULL) {
1553 kfree_skb(skb);
1554 return -ENODEV;
1555 }
1556 if (!dev->dn_ptr) {
1557 dev_put(dev);
1558 kfree_skb(skb);
1559 return -ENODEV;
1560 }
1561 skb->protocol = __constant_htons(ETH_P_DNA_RT);
1562 skb->dev = dev;
1563 cb->src = fl.fld_src;
1564 cb->dst = fl.fld_dst;
1565 local_bh_disable();
1566 err = dn_route_input(skb);
1567 local_bh_enable();
1568 memset(cb, 0, sizeof(struct dn_skb_cb));
1569 rt = (struct dn_route *)skb->dst;
1570 if (!err && -rt->u.dst.error)
1571 err = rt->u.dst.error;
1572 } else {
1573 int oif = 0;
1574 if (rta[RTA_OIF - 1])
1575 memcpy(&oif, RTA_DATA(rta[RTA_OIF - 1]), sizeof(int));
1576 fl.oif = oif;
1577 err = dn_route_output_key((struct dst_entry **)&rt, &fl, 0);
1578 }
1579
1580 if (skb->dev)
1581 dev_put(skb->dev);
1582 skb->dev = NULL;
1583 if (err)
1584 goto out_free;
1585 skb->dst = &rt->u.dst;
1586 if (rtm->rtm_flags & RTM_F_NOTIFY)
1587 rt->rt_flags |= RTCF_NOTIFY;
1588
1589 err = dn_rt_fill_info(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, RTM_NEWROUTE, 0, 0);
1590
1591 if (err == 0)
1592 goto out_free;
1593 if (err < 0) {
1594 err = -EMSGSIZE;
1595 goto out_free;
1596 }
1597
1598 return rtnl_unicast(skb, NETLINK_CB(in_skb).pid);
1599
1600 out_free:
1601 kfree_skb(skb);
1602 return err;
1603 }
1604
1605 /*
1606 * For routers, this is called from dn_fib_dump, but for endnodes its
1607 * called directly from the rtnetlink dispatch table.
1608 */
1609 int dn_cache_dump(struct sk_buff *skb, struct netlink_callback *cb)
1610 {
1611 struct dn_route *rt;
1612 int h, s_h;
1613 int idx, s_idx;
1614
1615 if (NLMSG_PAYLOAD(cb->nlh, 0) < sizeof(struct rtmsg))
1616 return -EINVAL;
1617 if (!(((struct rtmsg *)NLMSG_DATA(cb->nlh))->rtm_flags&RTM_F_CLONED))
1618 return 0;
1619
1620 s_h = cb->args[0];
1621 s_idx = idx = cb->args[1];
1622 for(h = 0; h <= dn_rt_hash_mask; h++) {
1623 if (h < s_h)
1624 continue;
1625 if (h > s_h)
1626 s_idx = 0;
1627 rcu_read_lock_bh();
1628 for(rt = rcu_dereference(dn_rt_hash_table[h].chain), idx = 0;
1629 rt;
1630 rt = rcu_dereference(rt->u.rt_next), idx++) {
1631 if (idx < s_idx)
1632 continue;
1633 skb->dst = dst_clone(&rt->u.dst);
1634 if (dn_rt_fill_info(skb, NETLINK_CB(cb->skb).pid,
1635 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
1636 1, NLM_F_MULTI) <= 0) {
1637 dst_release(xchg(&skb->dst, NULL));
1638 rcu_read_unlock_bh();
1639 goto done;
1640 }
1641 dst_release(xchg(&skb->dst, NULL));
1642 }
1643 rcu_read_unlock_bh();
1644 }
1645
1646 done:
1647 cb->args[0] = h;
1648 cb->args[1] = idx;
1649 return skb->len;
1650 }
1651
1652 #ifdef CONFIG_PROC_FS
1653 struct dn_rt_cache_iter_state {
1654 int bucket;
1655 };
1656
1657 static struct dn_route *dn_rt_cache_get_first(struct seq_file *seq)
1658 {
1659 struct dn_route *rt = NULL;
1660 struct dn_rt_cache_iter_state *s = seq->private;
1661
1662 for(s->bucket = dn_rt_hash_mask; s->bucket >= 0; --s->bucket) {
1663 rcu_read_lock_bh();
1664 rt = dn_rt_hash_table[s->bucket].chain;
1665 if (rt)
1666 break;
1667 rcu_read_unlock_bh();
1668 }
1669 return rt;
1670 }
1671
1672 static struct dn_route *dn_rt_cache_get_next(struct seq_file *seq, struct dn_route *rt)
1673 {
1674 struct dn_rt_cache_iter_state *s = rcu_dereference(seq->private);
1675
1676 rt = rt->u.rt_next;
1677 while(!rt) {
1678 rcu_read_unlock_bh();
1679 if (--s->bucket < 0)
1680 break;
1681 rcu_read_lock_bh();
1682 rt = dn_rt_hash_table[s->bucket].chain;
1683 }
1684 return rt;
1685 }
1686
1687 static void *dn_rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
1688 {
1689 struct dn_route *rt = dn_rt_cache_get_first(seq);
1690
1691 if (rt) {
1692 while(*pos && (rt = dn_rt_cache_get_next(seq, rt)))
1693 --*pos;
1694 }
1695 return *pos ? NULL : rt;
1696 }
1697
1698 static void *dn_rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1699 {
1700 struct dn_route *rt = dn_rt_cache_get_next(seq, v);
1701 ++*pos;
1702 return rt;
1703 }
1704
1705 static void dn_rt_cache_seq_stop(struct seq_file *seq, void *v)
1706 {
1707 if (v)
1708 rcu_read_unlock_bh();
1709 }
1710
1711 static int dn_rt_cache_seq_show(struct seq_file *seq, void *v)
1712 {
1713 struct dn_route *rt = v;
1714 char buf1[DN_ASCBUF_LEN], buf2[DN_ASCBUF_LEN];
1715
1716 seq_printf(seq, "%-8s %-7s %-7s %04d %04d %04d\n",
1717 rt->u.dst.dev ? rt->u.dst.dev->name : "*",
1718 dn_addr2asc(dn_ntohs(rt->rt_daddr), buf1),
1719 dn_addr2asc(dn_ntohs(rt->rt_saddr), buf2),
1720 atomic_read(&rt->u.dst.__refcnt),
1721 rt->u.dst.__use,
1722 (int) dst_metric(&rt->u.dst, RTAX_RTT));
1723 return 0;
1724 }
1725
1726 static struct seq_operations dn_rt_cache_seq_ops = {
1727 .start = dn_rt_cache_seq_start,
1728 .next = dn_rt_cache_seq_next,
1729 .stop = dn_rt_cache_seq_stop,
1730 .show = dn_rt_cache_seq_show,
1731 };
1732
1733 static int dn_rt_cache_seq_open(struct inode *inode, struct file *file)
1734 {
1735 struct seq_file *seq;
1736 int rc = -ENOMEM;
1737 struct dn_rt_cache_iter_state *s = kmalloc(sizeof(*s), GFP_KERNEL);
1738
1739 if (!s)
1740 goto out;
1741 rc = seq_open(file, &dn_rt_cache_seq_ops);
1742 if (rc)
1743 goto out_kfree;
1744 seq = file->private_data;
1745 seq->private = s;
1746 memset(s, 0, sizeof(*s));
1747 out:
1748 return rc;
1749 out_kfree:
1750 kfree(s);
1751 goto out;
1752 }
1753
1754 static struct file_operations dn_rt_cache_seq_fops = {
1755 .owner = THIS_MODULE,
1756 .open = dn_rt_cache_seq_open,
1757 .read = seq_read,
1758 .llseek = seq_lseek,
1759 .release = seq_release_private,
1760 };
1761
1762 #endif /* CONFIG_PROC_FS */
1763
1764 void __init dn_route_init(void)
1765 {
1766 int i, goal, order;
1767
1768 dn_dst_ops.kmem_cachep =
1769 kmem_cache_create("dn_dst_cache", sizeof(struct dn_route), 0,
1770 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
1771 init_timer(&dn_route_timer);
1772 dn_route_timer.function = dn_dst_check_expire;
1773 dn_route_timer.expires = jiffies + decnet_dst_gc_interval * HZ;
1774 add_timer(&dn_route_timer);
1775
1776 goal = num_physpages >> (26 - PAGE_SHIFT);
1777
1778 for(order = 0; (1UL << order) < goal; order++)
1779 /* NOTHING */;
1780
1781 /*
1782 * Only want 1024 entries max, since the table is very, very unlikely
1783 * to be larger than that.
1784 */
1785 while(order && ((((1UL << order) * PAGE_SIZE) /
1786 sizeof(struct dn_rt_hash_bucket)) >= 2048))
1787 order--;
1788
1789 do {
1790 dn_rt_hash_mask = (1UL << order) * PAGE_SIZE /
1791 sizeof(struct dn_rt_hash_bucket);
1792 while(dn_rt_hash_mask & (dn_rt_hash_mask - 1))
1793 dn_rt_hash_mask--;
1794 dn_rt_hash_table = (struct dn_rt_hash_bucket *)
1795 __get_free_pages(GFP_ATOMIC, order);
1796 } while (dn_rt_hash_table == NULL && --order > 0);
1797
1798 if (!dn_rt_hash_table)
1799 panic("Failed to allocate DECnet route cache hash table\n");
1800
1801 printk(KERN_INFO
1802 "DECnet: Routing cache hash table of %u buckets, %ldKbytes\n",
1803 dn_rt_hash_mask,
1804 (long)(dn_rt_hash_mask*sizeof(struct dn_rt_hash_bucket))/1024);
1805
1806 dn_rt_hash_mask--;
1807 for(i = 0; i <= dn_rt_hash_mask; i++) {
1808 spin_lock_init(&dn_rt_hash_table[i].lock);
1809 dn_rt_hash_table[i].chain = NULL;
1810 }
1811
1812 dn_dst_ops.gc_thresh = (dn_rt_hash_mask + 1);
1813
1814 proc_net_fops_create("decnet_cache", S_IRUGO, &dn_rt_cache_seq_fops);
1815 }
1816
1817 void __exit dn_route_cleanup(void)
1818 {
1819 del_timer(&dn_route_timer);
1820 dn_run_flush(0);
1821
1822 proc_net_remove("decnet_cache");
1823 }
1824
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