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/config.h>
59 #include <linux/errno.h>
60 #include <linux/types.h>
61 #include <linux/socket.h>
62 #include <linux/in.h>
63 #include <linux/kernel.h>
64 #include <linux/sockios.h>
65 #include <linux/net.h>
66 #include <linux/netdevice.h>
67 #include <linux/inet.h>
68 #include <linux/route.h>
69 #include <linux/in_route.h>
70 #include <net/sock.h>
71 #include <linux/mm.h>
72 #include <linux/proc_fs.h>
73 #include <linux/seq_file.h>
74 #include <linux/init.h>
75 #include <linux/rtnetlink.h>
76 #include <linux/string.h>
77 #include <linux/netfilter_decnet.h>
78 #include <linux/rcupdate.h>
79 #include <linux/times.h>
80 #include <asm/errno.h>
81 #include <net/neighbour.h>
82 #include <net/dst.h>
83 #include <net/flow.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 struct timer_list dn_rt_flush_timer =
121 TIMER_INITIALIZER(dn_run_flush, 0, 0);
122 int decnet_dst_gc_interval = 2;
123
124 static struct dst_ops dn_dst_ops = {
125 .family = PF_DECnet,
126 .protocol = __constant_htons(ETH_P_DNA_RT),
127 .gc_thresh = 128,
128 .gc = dn_dst_gc,
129 .check = dn_dst_check,
130 .negative_advice = dn_dst_negative_advice,
131 .link_failure = dn_dst_link_failure,
132 .update_pmtu = dn_dst_update_pmtu,
133 .entry_size = sizeof(struct dn_route),
134 .entries = ATOMIC_INIT(0),
135 };
136
137 static __inline__ unsigned dn_hash(unsigned short src, unsigned short dst)
138 {
139 unsigned short tmp = src ^ dst;
140 tmp ^= (tmp >> 3);
141 tmp ^= (tmp >> 5);
142 tmp ^= (tmp >> 10);
143 return dn_rt_hash_mask & (unsigned)tmp;
144 }
145
146 static inline void dnrt_free(struct dn_route *rt)
147 {
148 call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free);
149 }
150
151 static inline void dnrt_drop(struct dn_route *rt)
152 {
153 if (rt)
154 dst_release(&rt->u.dst);
155 call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free);
156 }
157
158 static void dn_dst_check_expire(unsigned long dummy)
159 {
160 int i;
161 struct dn_route *rt, **rtp;
162 unsigned long now = jiffies;
163 unsigned long expire = 120 * HZ;
164
165 for(i = 0; i <= dn_rt_hash_mask; i++) {
166 rtp = &dn_rt_hash_table[i].chain;
167
168 spin_lock(&dn_rt_hash_table[i].lock);
169 while((rt=*rtp) != NULL) {
170 if (atomic_read(&rt->u.dst.__refcnt) ||
171 (now - rt->u.dst.lastuse) < expire) {
172 rtp = &rt->u.rt_next;
173 continue;
174 }
175 *rtp = rt->u.rt_next;
176 rt->u.rt_next = NULL;
177 dnrt_free(rt);
178 }
179 spin_unlock(&dn_rt_hash_table[i].lock);
180
181 if ((jiffies - now) > 0)
182 break;
183 }
184
185 mod_timer(&dn_route_timer, now + decnet_dst_gc_interval * HZ);
186 }
187
188 static int dn_dst_gc(void)
189 {
190 struct dn_route *rt, **rtp;
191 int i;
192 unsigned long now = jiffies;
193 unsigned long expire = 10 * HZ;
194
195 for(i = 0; i <= dn_rt_hash_mask; i++) {
196
197 spin_lock_bh(&dn_rt_hash_table[i].lock);
198 rtp = &dn_rt_hash_table[i].chain;
199
200 while((rt=*rtp) != NULL) {
201 if (atomic_read(&rt->u.dst.__refcnt) ||
202 (now - rt->u.dst.lastuse) < expire) {
203 rtp = &rt->u.rt_next;
204 continue;
205 }
206 *rtp = rt->u.rt_next;
207 rt->u.rt_next = NULL;
208 dnrt_drop(rt);
209 break;
210 }
211 spin_unlock_bh(&dn_rt_hash_table[i].lock);
212 }
213
214 return 0;
215 }
216
217 /*
218 * The decnet standards don't impose a particular minimum mtu, what they
219 * do insist on is that the routing layer accepts a datagram of at least
220 * 230 bytes long. Here we have to subtract the routing header length from
221 * 230 to get the minimum acceptable mtu. If there is no neighbour, then we
222 * assume the worst and use a long header size.
223 *
224 * We update both the mtu and the advertised mss (i.e. the segment size we
225 * advertise to the other end).
226 */
227 static void dn_dst_update_pmtu(struct dst_entry *dst, u32 mtu)
228 {
229 u32 min_mtu = 230;
230 struct dn_dev *dn = dst->neighbour ?
231 (struct dn_dev *)dst->neighbour->dev->dn_ptr : NULL;
232
233 if (dn && dn->use_long == 0)
234 min_mtu -= 6;
235 else
236 min_mtu -= 21;
237
238 if (dst->metrics[RTAX_MTU-1] > mtu && mtu >= min_mtu) {
239 if (!(dst_metric_locked(dst, RTAX_MTU))) {
240 dst->metrics[RTAX_MTU-1] = mtu;
241 dst_set_expires(dst, dn_rt_mtu_expires);
242 }
243 if (!(dst_metric_locked(dst, RTAX_ADVMSS))) {
244 u32 mss = mtu - DN_MAX_NSP_DATA_HEADER;
245 if (dst->metrics[RTAX_ADVMSS-1] > mss)
246 dst->metrics[RTAX_ADVMSS-1] = mss;
247 }
248 }
249 }
250
251 /*
252 * When a route has been marked obsolete. (e.g. routing cache flush)
253 */
254 static struct dst_entry *dn_dst_check(struct dst_entry *dst, __u32 cookie)
255 {
256 dst_release(dst);
257 return NULL;
258 }
259
260 static struct dst_entry *dn_dst_negative_advice(struct dst_entry *dst)
261 {
262 dst_release(dst);
263 return NULL;
264 }
265
266 static void dn_dst_link_failure(struct sk_buff *skb)
267 {
268 return;
269 }
270
271 static inline int compare_keys(struct flowi *fl1, struct flowi *fl2)
272 {
273 return memcmp(&fl1->nl_u.dn_u, &fl2->nl_u.dn_u, sizeof(fl1->nl_u.dn_u)) == 0 &&
274 fl1->oif == fl2->oif &&
275 fl1->iif == fl2->iif;
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 dn_address *src;
385 dn_address *dst;
386 dn_address 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 = (dn_address *)ptr;
400 ptr += 2;
401 src = (dn_address *)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, cb->src, cb->dst,
481 err, skb->pkt_type);
482 }
483
484 if ((skb->pkt_type == PACKET_HOST) && (cb->rt_flags & DN_RT_F_RQR)) {
485 switch(cb->rt_flags & DN_RT_PKT_MSK) {
486 case DN_RT_PKT_SHORT:
487 return dn_return_short(skb);
488 case DN_RT_PKT_LONG:
489 return dn_return_long(skb);
490 }
491 }
492
493 kfree_skb(skb);
494 return NET_RX_DROP;
495 }
496
497 static int dn_route_rx_long(struct sk_buff *skb)
498 {
499 struct dn_skb_cb *cb = DN_SKB_CB(skb);
500 unsigned char *ptr = skb->data;
501
502 if (!pskb_may_pull(skb, 21)) /* 20 for long header, 1 for shortest nsp */
503 goto drop_it;
504
505 skb_pull(skb, 20);
506 skb->h.raw = skb->data;
507
508 /* Destination info */
509 ptr += 2;
510 cb->dst = dn_htons(dn_eth2dn(ptr));
511 if (memcmp(ptr, dn_hiord_addr, 4) != 0)
512 goto drop_it;
513 ptr += 6;
514
515
516 /* Source info */
517 ptr += 2;
518 cb->src = dn_htons(dn_eth2dn(ptr));
519 if (memcmp(ptr, dn_hiord_addr, 4) != 0)
520 goto drop_it;
521 ptr += 6;
522 /* Other junk */
523 ptr++;
524 cb->hops = *ptr++; /* Visit Count */
525
526 return NF_HOOK(PF_DECnet, NF_DN_PRE_ROUTING, skb, skb->dev, NULL, dn_route_rx_packet);
527
528 drop_it:
529 kfree_skb(skb);
530 return NET_RX_DROP;
531 }
532
533
534
535 static int dn_route_rx_short(struct sk_buff *skb)
536 {
537 struct dn_skb_cb *cb = DN_SKB_CB(skb);
538 unsigned char *ptr = skb->data;
539
540 if (!pskb_may_pull(skb, 6)) /* 5 for short header + 1 for shortest nsp */
541 goto drop_it;
542
543 skb_pull(skb, 5);
544 skb->h.raw = skb->data;
545
546 cb->dst = *(dn_address *)ptr;
547 ptr += 2;
548 cb->src = *(dn_address *)ptr;
549 ptr += 2;
550 cb->hops = *ptr & 0x3f;
551
552 return NF_HOOK(PF_DECnet, NF_DN_PRE_ROUTING, skb, skb->dev, NULL, dn_route_rx_packet);
553
554 drop_it:
555 kfree_skb(skb);
556 return NET_RX_DROP;
557 }
558
559 static int dn_route_discard(struct sk_buff *skb)
560 {
561 /*
562 * I know we drop the packet here, but thats considered success in
563 * this case
564 */
565 kfree_skb(skb);
566 return NET_RX_SUCCESS;
567 }
568
569 static int dn_route_ptp_hello(struct sk_buff *skb)
570 {
571 dn_dev_hello(skb);
572 dn_neigh_pointopoint_hello(skb);
573 return NET_RX_SUCCESS;
574 }
575
576 int dn_route_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt)
577 {
578 struct dn_skb_cb *cb;
579 unsigned char flags = 0;
580 __u16 len = dn_ntohs(*(__u16 *)skb->data);
581 struct dn_dev *dn = (struct dn_dev *)dev->dn_ptr;
582 unsigned char padlen = 0;
583
584 if (dn == NULL)
585 goto dump_it;
586
587 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
588 goto out;
589
590 if (!pskb_may_pull(skb, 3))
591 goto dump_it;
592
593 skb_pull(skb, 2);
594
595 if (len > skb->len)
596 goto dump_it;
597
598 skb_trim(skb, len);
599
600 flags = *skb->data;
601
602 cb = DN_SKB_CB(skb);
603 cb->stamp = jiffies;
604 cb->iif = dev->ifindex;
605
606 /*
607 * If we have padding, remove it.
608 */
609 if (flags & DN_RT_F_PF) {
610 padlen = flags & ~DN_RT_F_PF;
611 if (!pskb_may_pull(skb, padlen + 1))
612 goto dump_it;
613 skb_pull(skb, padlen);
614 flags = *skb->data;
615 }
616
617 skb->nh.raw = skb->data;
618
619 /*
620 * Weed out future version DECnet
621 */
622 if (flags & DN_RT_F_VER)
623 goto dump_it;
624
625 cb->rt_flags = flags;
626
627 if (decnet_debug_level & 1)
628 printk(KERN_DEBUG
629 "dn_route_rcv: got 0x%02x from %s [%d %d %d]\n",
630 (int)flags, (dev) ? dev->name : "???", len, skb->len,
631 padlen);
632
633 if (flags & DN_RT_PKT_CNTL) {
634 if (unlikely(skb_is_nonlinear(skb)) &&
635 skb_linearize(skb, GFP_ATOMIC) != 0)
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 cb->src, 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_pmtu(&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(__u16 addr1, __u16 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 __u16 dnet_select_source(const struct net_device *dev, __u16 daddr, int scope)
840 {
841 __u16 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 __u16 __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 __u16 dn_fib_rules_map_destination(__u16 daddr, struct dn_fib_res *res)
872 {
873 __u16 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 #ifdef CONFIG_DECNET_ROUTE_FWMARK
884 .fwmark = oldflp->fld_fwmark
885 #endif
886 } },
887 .iif = loopback_dev.ifindex,
888 .oif = oldflp->oif };
889 struct dn_route *rt = NULL;
890 struct net_device *dev_out = NULL;
891 struct neighbour *neigh = NULL;
892 unsigned hash;
893 unsigned flags = 0;
894 struct dn_fib_res res = { .fi = NULL, .type = RTN_UNICAST };
895 int err;
896 int free_res = 0;
897 __u16 gateway = 0;
898
899 if (decnet_debug_level & 16)
900 printk(KERN_DEBUG
901 "dn_route_output_slow: dst=%04x src=%04x mark=%d"
902 " iif=%d oif=%d\n", oldflp->fld_dst, oldflp->fld_src,
903 oldflp->fld_fwmark, loopback_dev.ifindex, oldflp->oif);
904
905 /* If we have an output interface, verify its a DECnet device */
906 if (oldflp->oif) {
907 dev_out = dev_get_by_index(oldflp->oif);
908 err = -ENODEV;
909 if (dev_out && dev_out->dn_ptr == NULL) {
910 dev_put(dev_out);
911 dev_out = NULL;
912 }
913 if (dev_out == NULL)
914 goto out;
915 }
916
917 /* If we have a source address, verify that its a local address */
918 if (oldflp->fld_src) {
919 err = -EADDRNOTAVAIL;
920
921 if (dev_out) {
922 if (dn_dev_islocal(dev_out, oldflp->fld_src))
923 goto source_ok;
924 dev_put(dev_out);
925 goto out;
926 }
927 read_lock(&dev_base_lock);
928 for(dev_out = dev_base; dev_out; dev_out = dev_out->next) {
929 if (!dev_out->dn_ptr)
930 continue;
931 if (dn_dev_islocal(dev_out, oldflp->fld_src))
932 break;
933 }
934 read_unlock(&dev_base_lock);
935 if (dev_out == NULL)
936 goto out;
937 dev_hold(dev_out);
938 source_ok:
939 ;
940 }
941
942 /* No destination? Assume its local */
943 if (!fl.fld_dst) {
944 fl.fld_dst = fl.fld_src;
945
946 err = -EADDRNOTAVAIL;
947 if (dev_out)
948 dev_put(dev_out);
949 dev_out = &loopback_dev;
950 dev_hold(dev_out);
951 if (!fl.fld_dst) {
952 fl.fld_dst =
953 fl.fld_src = dnet_select_source(dev_out, 0,
954 RT_SCOPE_HOST);
955 if (!fl.fld_dst)
956 goto out;
957 }
958 fl.oif = loopback_dev.ifindex;
959 res.type = RTN_LOCAL;
960 goto make_route;
961 }
962
963 if (decnet_debug_level & 16)
964 printk(KERN_DEBUG
965 "dn_route_output_slow: initial checks complete."
966 " dst=%o4x src=%04x oif=%d try_hard=%d\n", fl.fld_dst,
967 fl.fld_src, fl.oif, try_hard);
968
969 /*
970 * N.B. If the kernel is compiled without router support then
971 * dn_fib_lookup() will evaluate to non-zero so this if () block
972 * will always be executed.
973 */
974 err = -ESRCH;
975 if (try_hard || (err = dn_fib_lookup(&fl, &res)) != 0) {
976 struct dn_dev *dn_db;
977 if (err != -ESRCH)
978 goto out;
979 /*
980 * Here the fallback is basically the standard algorithm for
981 * routing in endnodes which is described in the DECnet routing
982 * docs
983 *
984 * If we are not trying hard, look in neighbour cache.
985 * The result is tested to ensure that if a specific output
986 * device/source address was requested, then we honour that
987 * here
988 */
989 if (!try_hard) {
990 neigh = neigh_lookup_nodev(&dn_neigh_table, &fl.fld_dst);
991 if (neigh) {
992 if ((oldflp->oif &&
993 (neigh->dev->ifindex != oldflp->oif)) ||
994 (oldflp->fld_src &&
995 (!dn_dev_islocal(neigh->dev,
996 oldflp->fld_src)))) {
997 neigh_release(neigh);
998 neigh = NULL;
999 } else {
1000 if (dev_out)
1001 dev_put(dev_out);
1002 if (dn_dev_islocal(neigh->dev, fl.fld_dst)) {
1003 dev_out = &loopback_dev;
1004 res.type = RTN_LOCAL;
1005 } else {
1006 dev_out = neigh->dev;
1007 }
1008 dev_hold(dev_out);
1009 goto select_source;
1010 }
1011 }
1012 }
1013
1014 /* Not there? Perhaps its a local address */
1015 if (dev_out == NULL)
1016 dev_out = dn_dev_get_default();
1017 err = -ENODEV;
1018 if (dev_out == NULL)
1019 goto out;
1020 dn_db = dev_out->dn_ptr;
1021 /* Possible improvement - check all devices for local addr */
1022 if (dn_dev_islocal(dev_out, fl.fld_dst)) {
1023 dev_put(dev_out);
1024 dev_out = &loopback_dev;
1025 dev_hold(dev_out);
1026 res.type = RTN_LOCAL;
1027 goto select_source;
1028 }
1029 /* Not local either.... try sending it to the default router */
1030 neigh = neigh_clone(dn_db->router);
1031 BUG_ON(neigh && neigh->dev != dev_out);
1032
1033 /* Ok then, we assume its directly connected and move on */
1034 select_source:
1035 if (neigh)
1036 gateway = ((struct dn_neigh *)neigh)->addr;
1037 if (gateway == 0)
1038 gateway = fl.fld_dst;
1039 if (fl.fld_src == 0) {
1040 fl.fld_src = dnet_select_source(dev_out, gateway,
1041 res.type == RTN_LOCAL ?
1042 RT_SCOPE_HOST :
1043 RT_SCOPE_LINK);
1044 if (fl.fld_src == 0 && res.type != RTN_LOCAL)
1045 goto e_addr;
1046 }
1047 fl.oif = dev_out->ifindex;
1048 goto make_route;
1049 }
1050 free_res = 1;
1051
1052 if (res.type == RTN_NAT)
1053 goto e_inval;
1054
1055 if (res.type == RTN_LOCAL) {
1056 if (!fl.fld_src)
1057 fl.fld_src = fl.fld_dst;
1058 if (dev_out)
1059 dev_put(dev_out);
1060 dev_out = &loopback_dev;
1061 dev_hold(dev_out);
1062 fl.oif = dev_out->ifindex;
1063 if (res.fi)
1064 dn_fib_info_put(res.fi);
1065 res.fi = NULL;
1066 goto make_route;
1067 }
1068
1069 if (res.fi->fib_nhs > 1 && fl.oif == 0)
1070 dn_fib_select_multipath(&fl, &res);
1071
1072 /*
1073 * We could add some logic to deal with default routes here and
1074 * get rid of some of the special casing above.
1075 */
1076
1077 if (!fl.fld_src)
1078 fl.fld_src = DN_FIB_RES_PREFSRC(res);
1079
1080 if (dev_out)
1081 dev_put(dev_out);
1082 dev_out = DN_FIB_RES_DEV(res);
1083 dev_hold(dev_out);
1084 fl.oif = dev_out->ifindex;
1085 gateway = DN_FIB_RES_GW(res);
1086
1087 make_route:
1088 if (dev_out->flags & IFF_LOOPBACK)
1089 flags |= RTCF_LOCAL;
1090
1091 rt = dst_alloc(&dn_dst_ops);
1092 if (rt == NULL)
1093 goto e_nobufs;
1094
1095 atomic_set(&rt->u.dst.__refcnt, 1);
1096 rt->u.dst.flags = DST_HOST;
1097
1098 rt->fl.fld_src = oldflp->fld_src;
1099 rt->fl.fld_dst = oldflp->fld_dst;
1100 rt->fl.oif = oldflp->oif;
1101 rt->fl.iif = 0;
1102 #ifdef CONFIG_DECNET_ROUTE_FWMARK
1103 rt->fl.fld_fwmark = oldflp->fld_fwmark;
1104 #endif
1105
1106 rt->rt_saddr = fl.fld_src;
1107 rt->rt_daddr = fl.fld_dst;
1108 rt->rt_gateway = gateway ? gateway : fl.fld_dst;
1109 rt->rt_local_src = fl.fld_src;
1110
1111 rt->rt_dst_map = fl.fld_dst;
1112 rt->rt_src_map = fl.fld_src;
1113
1114 rt->u.dst.dev = dev_out;
1115 dev_hold(dev_out);
1116 rt->u.dst.neighbour = neigh;
1117 neigh = NULL;
1118
1119 rt->u.dst.lastuse = jiffies;
1120 rt->u.dst.output = dn_output;
1121 rt->u.dst.input = dn_rt_bug;
1122 rt->rt_flags = flags;
1123 if (flags & RTCF_LOCAL)
1124 rt->u.dst.input = dn_nsp_rx;
1125
1126 err = dn_rt_set_next_hop(rt, &res);
1127 if (err)
1128 goto e_neighbour;
1129
1130 hash = dn_hash(rt->fl.fld_src, rt->fl.fld_dst);
1131 dn_insert_route(rt, hash, (struct dn_route **)pprt);
1132
1133 done:
1134 if (neigh)
1135 neigh_release(neigh);
1136 if (free_res)
1137 dn_fib_res_put(&res);
1138 if (dev_out)
1139 dev_put(dev_out);
1140 out:
1141 return err;
1142
1143 e_addr:
1144 err = -EADDRNOTAVAIL;
1145 goto done;
1146 e_inval:
1147 err = -EINVAL;
1148 goto done;
1149 e_nobufs:
1150 err = -ENOBUFS;
1151 goto done;
1152 e_neighbour:
1153 dst_free(&rt->u.dst);
1154 goto e_nobufs;
1155 }
1156
1157
1158 /*
1159 * N.B. The flags may be moved into the flowi at some future stage.
1160 */
1161 static int __dn_route_output_key(struct dst_entry **pprt, const struct flowi *flp, int flags)
1162 {
1163 unsigned hash = dn_hash(flp->fld_src, flp->fld_dst);
1164 struct dn_route *rt = NULL;
1165
1166 if (!(flags & MSG_TRYHARD)) {
1167 rcu_read_lock_bh();
1168 for(rt = rcu_dereference(dn_rt_hash_table[hash].chain); rt;
1169 rt = rcu_dereference(rt->u.rt_next)) {
1170 if ((flp->fld_dst == rt->fl.fld_dst) &&
1171 (flp->fld_src == rt->fl.fld_src) &&
1172 #ifdef CONFIG_DECNET_ROUTE_FWMARK
1173 (flp->fld_fwmark == rt->fl.fld_fwmark) &&
1174 #endif
1175 (rt->fl.iif == 0) &&
1176 (rt->fl.oif == flp->oif)) {
1177 rt->u.dst.lastuse = jiffies;
1178 dst_hold(&rt->u.dst);
1179 rt->u.dst.__use++;
1180 rcu_read_unlock_bh();
1181 *pprt = &rt->u.dst;
1182 return 0;
1183 }
1184 }
1185 rcu_read_unlock_bh();
1186 }
1187
1188 return dn_route_output_slow(pprt, flp, flags);
1189 }
1190
1191 static int dn_route_output_key(struct dst_entry **pprt, struct flowi *flp, int flags)
1192 {
1193 int err;
1194
1195 err = __dn_route_output_key(pprt, flp, flags);
1196 if (err == 0 && flp->proto) {
1197 err = xfrm_lookup(pprt, flp, NULL, 0);
1198 }
1199 return err;
1200 }
1201
1202 int dn_route_output_sock(struct dst_entry **pprt, struct flowi *fl, struct sock *sk, int flags)
1203 {
1204 int err;
1205
1206 err = __dn_route_output_key(pprt, fl, flags & MSG_TRYHARD);
1207 if (err == 0 && fl->proto) {
1208 err = xfrm_lookup(pprt, fl, sk, !(flags & MSG_DONTWAIT));
1209 }
1210 return err;
1211 }
1212
1213 static int dn_route_input_slow(struct sk_buff *skb)
1214 {
1215 struct dn_route *rt = NULL;
1216 struct dn_skb_cb *cb = DN_SKB_CB(skb);
1217 struct net_device *in_dev = skb->dev;
1218 struct net_device *out_dev = NULL;
1219 struct dn_dev *dn_db;
1220 struct neighbour *neigh = NULL;
1221 unsigned hash;
1222 int flags = 0;
1223 __u16 gateway = 0;
1224 __u16 local_src = 0;
1225 struct flowi fl = { .nl_u = { .dn_u =
1226 { .daddr = cb->dst,
1227 .saddr = cb->src,
1228 .scope = RT_SCOPE_UNIVERSE,
1229 #ifdef CONFIG_DECNET_ROUTE_FWMARK
1230 .fwmark = skb->nfmark
1231 #endif
1232 } },
1233 .iif = skb->dev->ifindex };
1234 struct dn_fib_res res = { .fi = NULL, .type = RTN_UNREACHABLE };
1235 int err = -EINVAL;
1236 int free_res = 0;
1237
1238 dev_hold(in_dev);
1239
1240 if ((dn_db = in_dev->dn_ptr) == NULL)
1241 goto out;
1242
1243 /* Zero source addresses are not allowed */
1244 if (fl.fld_src == 0)
1245 goto out;
1246
1247 /*
1248 * In this case we've just received a packet from a source
1249 * outside ourselves pretending to come from us. We don't
1250 * allow it any further to prevent routing loops, spoofing and
1251 * other nasties. Loopback packets already have the dst attached
1252 * so this only affects packets which have originated elsewhere.
1253 */
1254 err = -ENOTUNIQ;
1255 if (dn_dev_islocal(in_dev, cb->src))
1256 goto out;
1257
1258 err = dn_fib_lookup(&fl, &res);
1259 if (err) {
1260 if (err != -ESRCH)
1261 goto out;
1262 /*
1263 * Is the destination us ?
1264 */
1265 if (!dn_dev_islocal(in_dev, cb->dst))
1266 goto e_inval;
1267
1268 res.type = RTN_LOCAL;
1269 flags |= RTCF_DIRECTSRC;
1270 } else {
1271 __u16 src_map = fl.fld_src;
1272 free_res = 1;
1273
1274 out_dev = DN_FIB_RES_DEV(res);
1275 if (out_dev == NULL) {
1276 if (net_ratelimit())
1277 printk(KERN_CRIT "Bug in dn_route_input_slow() "
1278 "No output device\n");
1279 goto e_inval;
1280 }
1281 dev_hold(out_dev);
1282
1283 if (res.r)
1284 src_map = dn_fib_rules_policy(fl.fld_src, &res, &flags);
1285
1286 gateway = DN_FIB_RES_GW(res);
1287 if (res.type == RTN_NAT) {
1288 fl.fld_dst = dn_fib_rules_map_destination(fl.fld_dst, &res);
1289 dn_fib_res_put(&res);
1290 free_res = 0;
1291 if (dn_fib_lookup(&fl, &res))
1292 goto e_inval;
1293 free_res = 1;
1294 if (res.type != RTN_UNICAST)
1295 goto e_inval;
1296 flags |= RTCF_DNAT;
1297 gateway = fl.fld_dst;
1298 }
1299 fl.fld_src = src_map;
1300 }
1301
1302 switch(res.type) {
1303 case RTN_UNICAST:
1304 /*
1305 * Forwarding check here, we only check for forwarding
1306 * being turned off, if you want to only forward intra
1307 * area, its up to you to set the routing tables up
1308 * correctly.
1309 */
1310 if (dn_db->parms.forwarding == 0)
1311 goto e_inval;
1312
1313 if (res.fi->fib_nhs > 1 && fl.oif == 0)
1314 dn_fib_select_multipath(&fl, &res);
1315
1316 /*
1317 * Check for out_dev == in_dev. We use the RTCF_DOREDIRECT
1318 * flag as a hint to set the intra-ethernet bit when
1319 * forwarding. If we've got NAT in operation, we don't do
1320 * this optimisation.
1321 */
1322 if (out_dev == in_dev && !(flags & RTCF_NAT))
1323 flags |= RTCF_DOREDIRECT;
1324
1325 local_src = DN_FIB_RES_PREFSRC(res);
1326
1327 case RTN_BLACKHOLE:
1328 case RTN_UNREACHABLE:
1329 break;
1330 case RTN_LOCAL:
1331 flags |= RTCF_LOCAL;
1332 fl.fld_src = cb->dst;
1333 fl.fld_dst = cb->src;
1334
1335 /* Routing tables gave us a gateway */
1336 if (gateway)
1337 goto make_route;
1338
1339 /* Packet was intra-ethernet, so we know its on-link */
1340 if (cb->rt_flags | DN_RT_F_IE) {
1341 gateway = cb->src;
1342 flags |= RTCF_DIRECTSRC;
1343 goto make_route;
1344 }
1345
1346 /* Use the default router if there is one */
1347 neigh = neigh_clone(dn_db->router);
1348 if (neigh) {
1349 gateway = ((struct dn_neigh *)neigh)->addr;
1350 goto make_route;
1351 }
1352
1353 /* Close eyes and pray */
1354 gateway = cb->src;
1355 flags |= RTCF_DIRECTSRC;
1356 goto make_route;
1357 default:
1358 goto e_inval;
1359 }
1360
1361 make_route:
1362 rt = dst_alloc(&dn_dst_ops);
1363 if (rt == NULL)
1364 goto e_nobufs;
1365
1366 rt->rt_saddr = fl.fld_src;
1367 rt->rt_daddr = fl.fld_dst;
1368 rt->rt_gateway = fl.fld_dst;
1369 if (gateway)
1370 rt->rt_gateway = gateway;
1371 rt->rt_local_src = local_src ? local_src : rt->rt_saddr;
1372
1373 rt->rt_dst_map = fl.fld_dst;
1374 rt->rt_src_map = fl.fld_src;
1375
1376 rt->fl.fld_src = cb->src;
1377 rt->fl.fld_dst = cb->dst;
1378 rt->fl.oif = 0;
1379 rt->fl.iif = in_dev->ifindex;
1380 rt->fl.fld_fwmark = fl.fld_fwmark;
1381
1382 rt->u.dst.flags = DST_HOST;
1383 rt->u.dst.neighbour = neigh;
1384 rt->u.dst.dev = out_dev;
1385 rt->u.dst.lastuse = jiffies;
1386 rt->u.dst.output = dn_rt_bug;
1387 switch(res.type) {
1388 case RTN_UNICAST:
1389 rt->u.dst.input = dn_forward;
1390 break;
1391 case RTN_LOCAL:
1392 rt->u.dst.output = dn_output;
1393 rt->u.dst.input = dn_nsp_rx;
1394 rt->u.dst.dev = in_dev;
1395 flags |= RTCF_LOCAL;
1396 break;
1397 default:
1398 case RTN_UNREACHABLE:
1399 case RTN_BLACKHOLE:
1400 rt->u.dst.input = dn_blackhole;
1401 }
1402 rt->rt_flags = flags;
1403 if (rt->u.dst.dev)
1404 dev_hold(rt->u.dst.dev);
1405
1406 err = dn_rt_set_next_hop(rt, &res);
1407 if (err)
1408 goto e_neighbour;
1409
1410 hash = dn_hash(rt->fl.fld_src, rt->fl.fld_dst);
1411 dn_insert_route(rt, hash, (struct dn_route **)&skb->dst);
1412
1413 done:
1414 if (neigh)
1415 neigh_release(neigh);
1416 if (free_res)
1417 dn_fib_res_put(&res);
1418 dev_put(in_dev);
1419 if (out_dev)
1420 dev_put(out_dev);
1421 out:
1422 return err;
1423
1424 e_inval:
1425 err = -EINVAL;
1426 goto done;
1427
1428 e_nobufs:
1429 err = -ENOBUFS;
1430 goto done;
1431
1432 e_neighbour:
1433 dst_free(&rt->u.dst);
1434 goto done;
1435 }
1436
1437 int dn_route_input(struct sk_buff *skb)
1438 {
1439 struct dn_route *rt;
1440 struct dn_skb_cb *cb = DN_SKB_CB(skb);
1441 unsigned hash = dn_hash(cb->src, cb->dst);
1442
1443 if (skb->dst)
1444 return 0;
1445
1446 rcu_read_lock();
1447 for(rt = rcu_dereference(dn_rt_hash_table[hash].chain); rt != NULL;
1448 rt = rcu_dereference(rt->u.rt_next)) {
1449 if ((rt->fl.fld_src == cb->src) &&
1450 (rt->fl.fld_dst == cb->dst) &&
1451 (rt->fl.oif == 0) &&
1452 #ifdef CONFIG_DECNET_ROUTE_FWMARK
1453 (rt->fl.fld_fwmark == skb->nfmark) &&
1454 #endif
1455 (rt->fl.iif == cb->iif)) {
1456 rt->u.dst.lastuse = jiffies;
1457 dst_hold(&rt->u.dst);
1458 rt->u.dst.__use++;
1459 rcu_read_unlock();
1460 skb->dst = (struct dst_entry *)rt;
1461 return 0;
1462 }
1463 }
1464 rcu_read_unlock();
1465
1466 return dn_route_input_slow(skb);
1467 }
1468
1469 static int dn_rt_fill_info(struct sk_buff *skb, u32 pid, u32 seq, int event, int nowait)
1470 {
1471 struct dn_route *rt = (struct dn_route *)skb->dst;
1472 struct rtmsg *r;
1473 struct nlmsghdr *nlh;
1474 unsigned char *b = skb->tail;
1475 struct rta_cacheinfo ci;
1476
1477 nlh = NLMSG_PUT(skb, pid, seq, event, sizeof(*r));
1478 r = NLMSG_DATA(nlh);
1479 nlh->nlmsg_flags = (nowait && pid) ? NLM_F_MULTI : 0;
1480 r->rtm_family = AF_DECnet;
1481 r->rtm_dst_len = 16;
1482 r->rtm_src_len = 0;
1483 r->rtm_tos = 0;
1484 r->rtm_table = RT_TABLE_MAIN;
1485 r->rtm_type = rt->rt_type;
1486 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
1487 r->rtm_scope = RT_SCOPE_UNIVERSE;
1488 r->rtm_protocol = RTPROT_UNSPEC;
1489 if (rt->rt_flags & RTCF_NOTIFY)
1490 r->rtm_flags |= RTM_F_NOTIFY;
1491 RTA_PUT(skb, RTA_DST, 2, &rt->rt_daddr);
1492 if (rt->fl.fld_src) {
1493 r->rtm_src_len = 16;
1494 RTA_PUT(skb, RTA_SRC, 2, &rt->fl.fld_src);
1495 }
1496 if (rt->u.dst.dev)
1497 RTA_PUT(skb, RTA_OIF, sizeof(int), &rt->u.dst.dev->ifindex);
1498 /*
1499 * Note to self - change this if input routes reverse direction when
1500 * they deal only with inputs and not with replies like they do
1501 * currently.
1502 */
1503 RTA_PUT(skb, RTA_PREFSRC, 2, &rt->rt_local_src);
1504 if (rt->rt_daddr != rt->rt_gateway)
1505 RTA_PUT(skb, RTA_GATEWAY, 2, &rt->rt_gateway);
1506 if (rtnetlink_put_metrics(skb, rt->u.dst.metrics) < 0)
1507 goto rtattr_failure;
1508 ci.rta_lastuse = jiffies_to_clock_t(jiffies - rt->u.dst.lastuse);
1509 ci.rta_used = rt->u.dst.__use;
1510 ci.rta_clntref = atomic_read(&rt->u.dst.__refcnt);
1511 if (rt->u.dst.expires)
1512 ci.rta_expires = jiffies_to_clock_t(rt->u.dst.expires - jiffies);
1513 else
1514 ci.rta_expires = 0;
1515 ci.rta_error = rt->u.dst.error;
1516 ci.rta_id = ci.rta_ts = ci.rta_tsage = 0;
1517 RTA_PUT(skb, RTA_CACHEINFO, sizeof(ci), &ci);
1518 if (rt->fl.iif)
1519 RTA_PUT(skb, RTA_IIF, sizeof(int), &rt->fl.iif);
1520
1521 nlh->nlmsg_len = skb->tail - b;
1522 return skb->len;
1523
1524 nlmsg_failure:
1525 rtattr_failure:
1526 skb_trim(skb, b - skb->data);
1527 return -1;
1528 }
1529
1530 /*
1531 * This is called by both endnodes and routers now.
1532 */
1533 int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, void *arg)
1534 {
1535 struct rtattr **rta = arg;
1536 struct rtmsg *rtm = NLMSG_DATA(nlh);
1537 struct dn_route *rt = NULL;
1538 struct dn_skb_cb *cb;
1539 int err;
1540 struct sk_buff *skb;
1541 struct flowi fl;
1542
1543 memset(&fl, 0, sizeof(fl));
1544 fl.proto = DNPROTO_NSP;
1545
1546 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1547 if (skb == NULL)
1548 return -ENOBUFS;
1549 skb->mac.raw = skb->data;
1550 cb = DN_SKB_CB(skb);
1551
1552 if (rta[RTA_SRC-1])
1553 memcpy(&fl.fld_src, RTA_DATA(rta[RTA_SRC-1]), 2);
1554 if (rta[RTA_DST-1])
1555 memcpy(&fl.fld_dst, RTA_DATA(rta[RTA_DST-1]), 2);
1556 if (rta[RTA_IIF-1])
1557 memcpy(&fl.iif, RTA_DATA(rta[RTA_IIF-1]), sizeof(int));
1558
1559 if (fl.iif) {
1560 struct net_device *dev;
1561 if ((dev = dev_get_by_index(fl.iif)) == NULL) {
1562 kfree_skb(skb);
1563 return -ENODEV;
1564 }
1565 if (!dev->dn_ptr) {
1566 dev_put(dev);
1567 kfree_skb(skb);
1568 return -ENODEV;
1569 }
1570 skb->protocol = __constant_htons(ETH_P_DNA_RT);
1571 skb->dev = dev;
1572 cb->src = fl.fld_src;
1573 cb->dst = fl.fld_dst;
1574 local_bh_disable();
1575 err = dn_route_input(skb);
1576 local_bh_enable();
1577 memset(cb, 0, sizeof(struct dn_skb_cb));
1578 rt = (struct dn_route *)skb->dst;
1579 if (!err && -rt->u.dst.error)
1580 err = rt->u.dst.error;
1581 } else {
1582 int oif = 0;
1583 if (rta[RTA_OIF - 1])
1584 memcpy(&oif, RTA_DATA(rta[RTA_OIF - 1]), sizeof(int));
1585 fl.oif = oif;
1586 err = dn_route_output_key((struct dst_entry **)&rt, &fl, 0);
1587 }
1588
1589 if (skb->dev)
1590 dev_put(skb->dev);
1591 skb->dev = NULL;
1592 if (err)
1593 goto out_free;
1594 skb->dst = &rt->u.dst;
1595 if (rtm->rtm_flags & RTM_F_NOTIFY)
1596 rt->rt_flags |= RTCF_NOTIFY;
1597
1598 NETLINK_CB(skb).dst_pid = NETLINK_CB(in_skb).pid;
1599
1600 err = dn_rt_fill_info(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, RTM_NEWROUTE, 0);
1601
1602 if (err == 0)
1603 goto out_free;
1604 if (err < 0) {
1605 err = -EMSGSIZE;
1606 goto out_free;
1607 }
1608
1609 err = netlink_unicast(rtnl, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT);
1610
1611 return err;
1612
1613 out_free:
1614 kfree_skb(skb);
1615 return err;
1616 }
1617
1618 /*
1619 * For routers, this is called from dn_fib_dump, but for endnodes its
1620 * called directly from the rtnetlink dispatch table.
1621 */
1622 int dn_cache_dump(struct sk_buff *skb, struct netlink_callback *cb)
1623 {
1624 struct dn_route *rt;
1625 int h, s_h;
1626 int idx, s_idx;
1627
1628 if (NLMSG_PAYLOAD(cb->nlh, 0) < sizeof(struct rtmsg))
1629 return -EINVAL;
1630 if (!(((struct rtmsg *)NLMSG_DATA(cb->nlh))->rtm_flags&RTM_F_CLONED))
1631 return 0;
1632
1633 s_h = cb->args[0];
1634 s_idx = idx = cb->args[1];
1635 for(h = 0; h <= dn_rt_hash_mask; h++) {
1636 if (h < s_h)
1637 continue;
1638 if (h > s_h)
1639 s_idx = 0;
1640 rcu_read_lock_bh();
1641 for(rt = rcu_dereference(dn_rt_hash_table[h].chain), idx = 0;
1642 rt;
1643 rt = rcu_dereference(rt->u.rt_next), idx++) {
1644 if (idx < s_idx)
1645 continue;
1646 skb->dst = dst_clone(&rt->u.dst);
1647 if (dn_rt_fill_info(skb, NETLINK_CB(cb->skb).pid,
1648 cb->nlh->nlmsg_seq, RTM_NEWROUTE, 1) <= 0) {
1649 dst_release(xchg(&skb->dst, NULL));
1650 rcu_read_unlock_bh();
1651 goto done;
1652 }
1653 dst_release(xchg(&skb->dst, NULL));
1654 }
1655 rcu_read_unlock_bh();
1656 }
1657
1658 done:
1659 cb->args[0] = h;
1660 cb->args[1] = idx;
1661 return skb->len;
1662 }
1663
1664 #ifdef CONFIG_PROC_FS
1665 struct dn_rt_cache_iter_state {
1666 int bucket;
1667 };
1668
1669 static struct dn_route *dn_rt_cache_get_first(struct seq_file *seq)
1670 {
1671 struct dn_route *rt = NULL;
1672 struct dn_rt_cache_iter_state *s = seq->private;
1673
1674 for(s->bucket = dn_rt_hash_mask; s->bucket >= 0; --s->bucket) {
1675 rcu_read_lock_bh();
1676 rt = dn_rt_hash_table[s->bucket].chain;
1677 if (rt)
1678 break;
1679 rcu_read_unlock_bh();
1680 }
1681 return rt;
1682 }
1683
1684 static struct dn_route *dn_rt_cache_get_next(struct seq_file *seq, struct dn_route *rt)
1685 {
1686 struct dn_rt_cache_iter_state *s = rcu_dereference(seq->private);
1687
1688 rt = rt->u.rt_next;
1689 while(!rt) {
1690 rcu_read_unlock_bh();
1691 if (--s->bucket < 0)
1692 break;
1693 rcu_read_lock_bh();
1694 rt = dn_rt_hash_table[s->bucket].chain;
1695 }
1696 return rt;
1697 }
1698
1699 static void *dn_rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
1700 {
1701 struct dn_route *rt = dn_rt_cache_get_first(seq);
1702
1703 if (rt) {
1704 while(*pos && (rt = dn_rt_cache_get_next(seq, rt)))
1705 --*pos;
1706 }
1707 return *pos ? NULL : rt;
1708 }
1709
1710 static void *dn_rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1711 {
1712 struct dn_route *rt = dn_rt_cache_get_next(seq, v);
1713 ++*pos;
1714 return rt;
1715 }
1716
1717 static void dn_rt_cache_seq_stop(struct seq_file *seq, void *v)
1718 {
1719 if (v)
1720 rcu_read_unlock_bh();
1721 }
1722
1723 static int dn_rt_cache_seq_show(struct seq_file *seq, void *v)
1724 {
1725 struct dn_route *rt = v;
1726 char buf1[DN_ASCBUF_LEN], buf2[DN_ASCBUF_LEN];
1727
1728 seq_printf(seq, "%-8s %-7s %-7s %04d %04d %04d\n",
1729 rt->u.dst.dev ? rt->u.dst.dev->name : "*",
1730 dn_addr2asc(dn_ntohs(rt->rt_daddr), buf1),
1731 dn_addr2asc(dn_ntohs(rt->rt_saddr), buf2),
1732 atomic_read(&rt->u.dst.__refcnt),
1733 rt->u.dst.__use,
1734 (int) dst_metric(&rt->u.dst, RTAX_RTT));
1735 return 0;
1736 }
1737
1738 static struct seq_operations dn_rt_cache_seq_ops = {
1739 .start = dn_rt_cache_seq_start,
1740 .next = dn_rt_cache_seq_next,
1741 .stop = dn_rt_cache_seq_stop,
1742 .show = dn_rt_cache_seq_show,
1743 };
1744
1745 static int dn_rt_cache_seq_open(struct inode *inode, struct file *file)
1746 {
1747 struct seq_file *seq;
1748 int rc = -ENOMEM;
1749 struct dn_rt_cache_iter_state *s = kmalloc(sizeof(*s), GFP_KERNEL);
1750
1751 if (!s)
1752 goto out;
1753 rc = seq_open(file, &dn_rt_cache_seq_ops);
1754 if (rc)
1755 goto out_kfree;
1756 seq = file->private_data;
1757 seq->private = s;
1758 memset(s, 0, sizeof(*s));
1759 out:
1760 return rc;
1761 out_kfree:
1762 kfree(s);
1763 goto out;
1764 }
1765
1766 static struct file_operations dn_rt_cache_seq_fops = {
1767 .owner = THIS_MODULE,
1768 .open = dn_rt_cache_seq_open,
1769 .read = seq_read,
1770 .llseek = seq_lseek,
1771 .release = seq_release_private,
1772 };
1773
1774 #endif /* CONFIG_PROC_FS */
1775
1776 void __init dn_route_init(void)
1777 {
1778 int i, goal, order;
1779
1780 dn_dst_ops.kmem_cachep = kmem_cache_create("dn_dst_cache",
1781 sizeof(struct dn_route),
1782 0, SLAB_HWCACHE_ALIGN,
1783 NULL, NULL);
1784
1785 if (!dn_dst_ops.kmem_cachep)
1786 panic("DECnet: Failed to allocate dn_dst_cache\n");
1787
1788 init_timer(&dn_route_timer);
1789 dn_route_timer.function = dn_dst_check_expire;
1790 dn_route_timer.expires = jiffies + decnet_dst_gc_interval * HZ;
1791 add_timer(&dn_route_timer);
1792
1793 goal = num_physpages >> (26 - PAGE_SHIFT);
1794
1795 for(order = 0; (1UL << order) < goal; order++)
1796 /* NOTHING */;
1797
1798 /*
1799 * Only want 1024 entries max, since the table is very, very unlikely
1800 * to be larger than that.
1801 */
1802 while(order && ((((1UL << order) * PAGE_SIZE) /
1803 sizeof(struct dn_rt_hash_bucket)) >= 2048))
1804 order--;
1805
1806 do {
1807 dn_rt_hash_mask = (1UL << order) * PAGE_SIZE /
1808 sizeof(struct dn_rt_hash_bucket);
1809 while(dn_rt_hash_mask & (dn_rt_hash_mask - 1))
1810 dn_rt_hash_mask--;
1811 dn_rt_hash_table = (struct dn_rt_hash_bucket *)
1812 __get_free_pages(GFP_ATOMIC, order);
1813 } while (dn_rt_hash_table == NULL && --order > 0);
1814
1815 if (!dn_rt_hash_table)
1816 panic("Failed to allocate DECnet route cache hash table\n");
1817
1818 printk(KERN_INFO
1819 "DECnet: Routing cache hash table of %u buckets, %ldKbytes\n",
1820 dn_rt_hash_mask,
1821 (long)(dn_rt_hash_mask*sizeof(struct dn_rt_hash_bucket))/1024);
1822
1823 dn_rt_hash_mask--;
1824 for(i = 0; i <= dn_rt_hash_mask; i++) {
1825 spin_lock_init(&dn_rt_hash_table[i].lock);
1826 dn_rt_hash_table[i].chain = NULL;
1827 }
1828
1829 dn_dst_ops.gc_thresh = (dn_rt_hash_mask + 1);
1830
1831 proc_net_fops_create("decnet_cache", S_IRUGO, &dn_rt_cache_seq_fops);
1832 }
1833
1834 void __exit dn_route_cleanup(void)
1835 {
1836 del_timer(&dn_route_timer);
1837 dn_run_flush(0);
1838
1839 proc_net_remove("decnet_cache");
1840 }
1841
1842
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