1 /*
2 * DECnet An implementation of the DECnet protocol suite for the LINUX
3 * operating system. DECnet is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * DECnet Routing Functions (Endnode and Router)
7 *
8 * Authors: Steve Whitehouse <SteveW@ACM.org>
9 * Eduardo Marcelo Serrat <emserrat@geocities.com>
10 *
11 * Changes:
12 * Steve Whitehouse : Fixes to allow "intra-ethernet" and
13 * "return-to-sender" bits on outgoing
14 * packets.
15 * Steve Whitehouse : Timeouts for cached routes.
16 * Steve Whitehouse : Use dst cache for input routes too.
17 * Steve Whitehouse : Fixed error values in dn_send_skb.
18 * Steve Whitehouse : Rework routing functions to better fit
19 * DECnet routing design
20 * Alexey Kuznetsov : New SMP locking
21 * Steve Whitehouse : More SMP locking changes & dn_cache_dump()
22 * Steve Whitehouse : Prerouting NF hook, now really is prerouting.
23 * Fixed possible skb leak in rtnetlink funcs.
24 * Steve Whitehouse : Dave Miller's dynamic hash table sizing and
25 * Alexey Kuznetsov's finer grained locking
26 * from ipv4/route.c.
27 * Steve Whitehouse : Routing is now starting to look like a
28 * sensible set of code now, mainly due to
29 * my copying the IPv4 routing code. The
30 * hooks here are modified and will continue
31 * to evolve for a while.
32 * Steve Whitehouse : Real SMP at last :-) Also new netfilter
33 * stuff. Look out raw sockets your days
34 * are numbered!
35 * Steve Whitehouse : Added return-to-sender functions. Added
36 * backlog congestion level return codes.
37 * Steve Whitehouse : Fixed bug where routes were set up with
38 * no ref count on net devices.
39 * Steve Whitehouse : RCU for the route cache
40 * Steve Whitehouse : Preparations for the flow cache
41 * Steve Whitehouse : Prepare for nonlinear skbs
42 */
43
44 /******************************************************************************
45 (c) 1995-1998 E.M. Serrat emserrat@geocities.com
46
47 This program is free software; you can redistribute it and/or modify
48 it under the terms of the GNU General Public License as published by
49 the Free Software Foundation; either version 2 of the License, or
50 any later version.
51
52 This program is distributed in the hope that it will be useful,
53 but WITHOUT ANY WARRANTY; without even the implied warranty of
54 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
55 GNU General Public License for more details.
56 *******************************************************************************/
57
58 #include <linux/errno.h>
59 #include <linux/types.h>
60 #include <linux/socket.h>
61 #include <linux/in.h>
62 #include <linux/kernel.h>
63 #include <linux/sockios.h>
64 #include <linux/net.h>
65 #include <linux/netdevice.h>
66 #include <linux/inet.h>
67 #include <linux/route.h>
68 #include <linux/in_route.h>
69 #include <linux/slab.h>
70 #include <net/sock.h>
71 #include <linux/mm.h>
72 #include <linux/proc_fs.h>
73 #include <linux/seq_file.h>
74 #include <linux/init.h>
75 #include <linux/rtnetlink.h>
76 #include <linux/string.h>
77 #include <linux/netfilter_decnet.h>
78 #include <linux/rcupdate.h>
79 #include <linux/times.h>
80 #include <linux/export.h>
81 #include <asm/errno.h>
82 #include <net/net_namespace.h>
83 #include <net/netlink.h>
84 #include <net/neighbour.h>
85 #include <net/dst.h>
86 #include <net/flow.h>
87 #include <net/fib_rules.h>
88 #include <net/dn.h>
89 #include <net/dn_dev.h>
90 #include <net/dn_nsp.h>
91 #include <net/dn_route.h>
92 #include <net/dn_neigh.h>
93 #include <net/dn_fib.h>
94
95 struct dn_rt_hash_bucket
96 {
97 struct dn_route __rcu *chain;
98 spinlock_t lock;
99 };
100
101 extern struct neigh_table dn_neigh_table;
102
103
104 static unsigned char dn_hiord_addr[6] = {0xAA,0x00,0x04,0x00,0x00,0x00};
105
106 static const int dn_rt_min_delay = 2 * HZ;
107 static const int dn_rt_max_delay = 10 * HZ;
108 static const int dn_rt_mtu_expires = 10 * 60 * HZ;
109
110 static unsigned long dn_rt_deadline;
111
112 static int dn_dst_gc(struct dst_ops *ops);
113 static struct dst_entry *dn_dst_check(struct dst_entry *, __u32);
114 static unsigned int dn_dst_default_advmss(const struct dst_entry *dst);
115 static unsigned int dn_dst_mtu(const struct dst_entry *dst);
116 static void dn_dst_destroy(struct dst_entry *);
117 static struct dst_entry *dn_dst_negative_advice(struct dst_entry *);
118 static void dn_dst_link_failure(struct sk_buff *);
119 static void dn_dst_update_pmtu(struct dst_entry *dst, u32 mtu);
120 static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst, const void *daddr);
121 static int dn_route_input(struct sk_buff *);
122 static void dn_run_flush(unsigned long dummy);
123
124 static struct dn_rt_hash_bucket *dn_rt_hash_table;
125 static unsigned dn_rt_hash_mask;
126
127 static struct timer_list dn_route_timer;
128 static DEFINE_TIMER(dn_rt_flush_timer, dn_run_flush, 0, 0);
129 int decnet_dst_gc_interval = 2;
130
131 static struct dst_ops dn_dst_ops = {
132 .family = PF_DECnet,
133 .protocol = cpu_to_be16(ETH_P_DNA_RT),
134 .gc_thresh = 128,
135 .gc = dn_dst_gc,
136 .check = dn_dst_check,
137 .default_advmss = dn_dst_default_advmss,
138 .mtu = dn_dst_mtu,
139 .cow_metrics = dst_cow_metrics_generic,
140 .destroy = dn_dst_destroy,
141 .negative_advice = dn_dst_negative_advice,
142 .link_failure = dn_dst_link_failure,
143 .update_pmtu = dn_dst_update_pmtu,
144 .neigh_lookup = dn_dst_neigh_lookup,
145 };
146
dn_dst_destroy(struct dst_entry * dst)147 static void dn_dst_destroy(struct dst_entry *dst)
148 {
149 dst_destroy_metrics_generic(dst);
150 }
151
dn_hash(__le16 src,__le16 dst)152 static __inline__ unsigned dn_hash(__le16 src, __le16 dst)
153 {
154 __u16 tmp = (__u16 __force)(src ^ dst);
155 tmp ^= (tmp >> 3);
156 tmp ^= (tmp >> 5);
157 tmp ^= (tmp >> 10);
158 return dn_rt_hash_mask & (unsigned)tmp;
159 }
160
dnrt_free(struct dn_route * rt)161 static inline void dnrt_free(struct dn_route *rt)
162 {
163 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
164 }
165
dnrt_drop(struct dn_route * rt)166 static inline void dnrt_drop(struct dn_route *rt)
167 {
168 dst_release(&rt->dst);
169 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
170 }
171
dn_dst_check_expire(unsigned long dummy)172 static void dn_dst_check_expire(unsigned long dummy)
173 {
174 int i;
175 struct dn_route *rt;
176 struct dn_route __rcu **rtp;
177 unsigned long now = jiffies;
178 unsigned long expire = 120 * HZ;
179
180 for (i = 0; i <= dn_rt_hash_mask; i++) {
181 rtp = &dn_rt_hash_table[i].chain;
182
183 spin_lock(&dn_rt_hash_table[i].lock);
184 while ((rt = rcu_dereference_protected(*rtp,
185 lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) {
186 if (atomic_read(&rt->dst.__refcnt) ||
187 (now - rt->dst.lastuse) < expire) {
188 rtp = &rt->dst.dn_next;
189 continue;
190 }
191 *rtp = rt->dst.dn_next;
192 rt->dst.dn_next = NULL;
193 dnrt_free(rt);
194 }
195 spin_unlock(&dn_rt_hash_table[i].lock);
196
197 if ((jiffies - now) > 0)
198 break;
199 }
200
201 mod_timer(&dn_route_timer, now + decnet_dst_gc_interval * HZ);
202 }
203
dn_dst_gc(struct dst_ops * ops)204 static int dn_dst_gc(struct dst_ops *ops)
205 {
206 struct dn_route *rt;
207 struct dn_route __rcu **rtp;
208 int i;
209 unsigned long now = jiffies;
210 unsigned long expire = 10 * HZ;
211
212 for (i = 0; i <= dn_rt_hash_mask; i++) {
213
214 spin_lock_bh(&dn_rt_hash_table[i].lock);
215 rtp = &dn_rt_hash_table[i].chain;
216
217 while ((rt = rcu_dereference_protected(*rtp,
218 lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) {
219 if (atomic_read(&rt->dst.__refcnt) ||
220 (now - rt->dst.lastuse) < expire) {
221 rtp = &rt->dst.dn_next;
222 continue;
223 }
224 *rtp = rt->dst.dn_next;
225 rt->dst.dn_next = NULL;
226 dnrt_drop(rt);
227 break;
228 }
229 spin_unlock_bh(&dn_rt_hash_table[i].lock);
230 }
231
232 return 0;
233 }
234
235 /*
236 * The decnet standards don't impose a particular minimum mtu, what they
237 * do insist on is that the routing layer accepts a datagram of at least
238 * 230 bytes long. Here we have to subtract the routing header length from
239 * 230 to get the minimum acceptable mtu. If there is no neighbour, then we
240 * assume the worst and use a long header size.
241 *
242 * We update both the mtu and the advertised mss (i.e. the segment size we
243 * advertise to the other end).
244 */
dn_dst_update_pmtu(struct dst_entry * dst,u32 mtu)245 static void dn_dst_update_pmtu(struct dst_entry *dst, u32 mtu)
246 {
247 struct neighbour *n = dst_get_neighbour_noref(dst);
248 u32 min_mtu = 230;
249 struct dn_dev *dn;
250
251 dn = n ? rcu_dereference_raw(n->dev->dn_ptr) : NULL;
252
253 if (dn && dn->use_long == 0)
254 min_mtu -= 6;
255 else
256 min_mtu -= 21;
257
258 if (dst_metric(dst, RTAX_MTU) > mtu && mtu >= min_mtu) {
259 if (!(dst_metric_locked(dst, RTAX_MTU))) {
260 dst_metric_set(dst, RTAX_MTU, mtu);
261 dst_set_expires(dst, dn_rt_mtu_expires);
262 }
263 if (!(dst_metric_locked(dst, RTAX_ADVMSS))) {
264 u32 mss = mtu - DN_MAX_NSP_DATA_HEADER;
265 u32 existing_mss = dst_metric_raw(dst, RTAX_ADVMSS);
266 if (!existing_mss || existing_mss > mss)
267 dst_metric_set(dst, RTAX_ADVMSS, mss);
268 }
269 }
270 }
271
272 /*
273 * When a route has been marked obsolete. (e.g. routing cache flush)
274 */
dn_dst_check(struct dst_entry * dst,__u32 cookie)275 static struct dst_entry *dn_dst_check(struct dst_entry *dst, __u32 cookie)
276 {
277 return NULL;
278 }
279
dn_dst_negative_advice(struct dst_entry * dst)280 static struct dst_entry *dn_dst_negative_advice(struct dst_entry *dst)
281 {
282 dst_release(dst);
283 return NULL;
284 }
285
dn_dst_link_failure(struct sk_buff * skb)286 static void dn_dst_link_failure(struct sk_buff *skb)
287 {
288 }
289
compare_keys(struct flowidn * fl1,struct flowidn * fl2)290 static inline int compare_keys(struct flowidn *fl1, struct flowidn *fl2)
291 {
292 return ((fl1->daddr ^ fl2->daddr) |
293 (fl1->saddr ^ fl2->saddr) |
294 (fl1->flowidn_mark ^ fl2->flowidn_mark) |
295 (fl1->flowidn_scope ^ fl2->flowidn_scope) |
296 (fl1->flowidn_oif ^ fl2->flowidn_oif) |
297 (fl1->flowidn_iif ^ fl2->flowidn_iif)) == 0;
298 }
299
dn_insert_route(struct dn_route * rt,unsigned hash,struct dn_route ** rp)300 static int dn_insert_route(struct dn_route *rt, unsigned hash, struct dn_route **rp)
301 {
302 struct dn_route *rth;
303 struct dn_route __rcu **rthp;
304 unsigned long now = jiffies;
305
306 rthp = &dn_rt_hash_table[hash].chain;
307
308 spin_lock_bh(&dn_rt_hash_table[hash].lock);
309 while ((rth = rcu_dereference_protected(*rthp,
310 lockdep_is_held(&dn_rt_hash_table[hash].lock))) != NULL) {
311 if (compare_keys(&rth->fld, &rt->fld)) {
312 /* Put it first */
313 *rthp = rth->dst.dn_next;
314 rcu_assign_pointer(rth->dst.dn_next,
315 dn_rt_hash_table[hash].chain);
316 rcu_assign_pointer(dn_rt_hash_table[hash].chain, rth);
317
318 dst_use(&rth->dst, now);
319 spin_unlock_bh(&dn_rt_hash_table[hash].lock);
320
321 dnrt_drop(rt);
322 *rp = rth;
323 return 0;
324 }
325 rthp = &rth->dst.dn_next;
326 }
327
328 rcu_assign_pointer(rt->dst.dn_next, dn_rt_hash_table[hash].chain);
329 rcu_assign_pointer(dn_rt_hash_table[hash].chain, rt);
330
331 dst_use(&rt->dst, now);
332 spin_unlock_bh(&dn_rt_hash_table[hash].lock);
333 *rp = rt;
334 return 0;
335 }
336
dn_run_flush(unsigned long dummy)337 static void dn_run_flush(unsigned long dummy)
338 {
339 int i;
340 struct dn_route *rt, *next;
341
342 for (i = 0; i < dn_rt_hash_mask; i++) {
343 spin_lock_bh(&dn_rt_hash_table[i].lock);
344
345 if ((rt = xchg((struct dn_route **)&dn_rt_hash_table[i].chain, NULL)) == NULL)
346 goto nothing_to_declare;
347
348 for(; rt; rt = next) {
349 next = rcu_dereference_raw(rt->dst.dn_next);
350 RCU_INIT_POINTER(rt->dst.dn_next, NULL);
351 dst_free((struct dst_entry *)rt);
352 }
353
354 nothing_to_declare:
355 spin_unlock_bh(&dn_rt_hash_table[i].lock);
356 }
357 }
358
359 static DEFINE_SPINLOCK(dn_rt_flush_lock);
360
dn_rt_cache_flush(int delay)361 void dn_rt_cache_flush(int delay)
362 {
363 unsigned long now = jiffies;
364 int user_mode = !in_interrupt();
365
366 if (delay < 0)
367 delay = dn_rt_min_delay;
368
369 spin_lock_bh(&dn_rt_flush_lock);
370
371 if (del_timer(&dn_rt_flush_timer) && delay > 0 && dn_rt_deadline) {
372 long tmo = (long)(dn_rt_deadline - now);
373
374 if (user_mode && tmo < dn_rt_max_delay - dn_rt_min_delay)
375 tmo = 0;
376
377 if (delay > tmo)
378 delay = tmo;
379 }
380
381 if (delay <= 0) {
382 spin_unlock_bh(&dn_rt_flush_lock);
383 dn_run_flush(0);
384 return;
385 }
386
387 if (dn_rt_deadline == 0)
388 dn_rt_deadline = now + dn_rt_max_delay;
389
390 dn_rt_flush_timer.expires = now + delay;
391 add_timer(&dn_rt_flush_timer);
392 spin_unlock_bh(&dn_rt_flush_lock);
393 }
394
395 /**
396 * dn_return_short - Return a short packet to its sender
397 * @skb: The packet to return
398 *
399 */
dn_return_short(struct sk_buff * skb)400 static int dn_return_short(struct sk_buff *skb)
401 {
402 struct dn_skb_cb *cb;
403 unsigned char *ptr;
404 __le16 *src;
405 __le16 *dst;
406
407 /* Add back headers */
408 skb_push(skb, skb->data - skb_network_header(skb));
409
410 if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
411 return NET_RX_DROP;
412
413 cb = DN_SKB_CB(skb);
414 /* Skip packet length and point to flags */
415 ptr = skb->data + 2;
416 *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
417
418 dst = (__le16 *)ptr;
419 ptr += 2;
420 src = (__le16 *)ptr;
421 ptr += 2;
422 *ptr = 0; /* Zero hop count */
423
424 swap(*src, *dst);
425
426 skb->pkt_type = PACKET_OUTGOING;
427 dn_rt_finish_output(skb, NULL, NULL);
428 return NET_RX_SUCCESS;
429 }
430
431 /**
432 * dn_return_long - Return a long packet to its sender
433 * @skb: The long format packet to return
434 *
435 */
dn_return_long(struct sk_buff * skb)436 static int dn_return_long(struct sk_buff *skb)
437 {
438 struct dn_skb_cb *cb;
439 unsigned char *ptr;
440 unsigned char *src_addr, *dst_addr;
441 unsigned char tmp[ETH_ALEN];
442
443 /* Add back all headers */
444 skb_push(skb, skb->data - skb_network_header(skb));
445
446 if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
447 return NET_RX_DROP;
448
449 cb = DN_SKB_CB(skb);
450 /* Ignore packet length and point to flags */
451 ptr = skb->data + 2;
452
453 /* Skip padding */
454 if (*ptr & DN_RT_F_PF) {
455 char padlen = (*ptr & ~DN_RT_F_PF);
456 ptr += padlen;
457 }
458
459 *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
460 ptr += 2;
461 dst_addr = ptr;
462 ptr += 8;
463 src_addr = ptr;
464 ptr += 6;
465 *ptr = 0; /* Zero hop count */
466
467 /* Swap source and destination */
468 memcpy(tmp, src_addr, ETH_ALEN);
469 memcpy(src_addr, dst_addr, ETH_ALEN);
470 memcpy(dst_addr, tmp, ETH_ALEN);
471
472 skb->pkt_type = PACKET_OUTGOING;
473 dn_rt_finish_output(skb, dst_addr, src_addr);
474 return NET_RX_SUCCESS;
475 }
476
477 /**
478 * dn_route_rx_packet - Try and find a route for an incoming packet
479 * @skb: The packet to find a route for
480 *
481 * Returns: result of input function if route is found, error code otherwise
482 */
dn_route_rx_packet(struct sk_buff * skb)483 static int dn_route_rx_packet(struct sk_buff *skb)
484 {
485 struct dn_skb_cb *cb;
486 int err;
487
488 if ((err = dn_route_input(skb)) == 0)
489 return dst_input(skb);
490
491 cb = DN_SKB_CB(skb);
492 if (decnet_debug_level & 4) {
493 char *devname = skb->dev ? skb->dev->name : "???";
494
495 printk(KERN_DEBUG
496 "DECnet: dn_route_rx_packet: rt_flags=0x%02x dev=%s len=%d src=0x%04hx dst=0x%04hx err=%d type=%d\n",
497 (int)cb->rt_flags, devname, skb->len,
498 le16_to_cpu(cb->src), le16_to_cpu(cb->dst),
499 err, skb->pkt_type);
500 }
501
502 if ((skb->pkt_type == PACKET_HOST) && (cb->rt_flags & DN_RT_F_RQR)) {
503 switch (cb->rt_flags & DN_RT_PKT_MSK) {
504 case DN_RT_PKT_SHORT:
505 return dn_return_short(skb);
506 case DN_RT_PKT_LONG:
507 return dn_return_long(skb);
508 }
509 }
510
511 kfree_skb(skb);
512 return NET_RX_DROP;
513 }
514
dn_route_rx_long(struct sk_buff * skb)515 static int dn_route_rx_long(struct sk_buff *skb)
516 {
517 struct dn_skb_cb *cb = DN_SKB_CB(skb);
518 unsigned char *ptr = skb->data;
519
520 if (!pskb_may_pull(skb, 21)) /* 20 for long header, 1 for shortest nsp */
521 goto drop_it;
522
523 skb_pull(skb, 20);
524 skb_reset_transport_header(skb);
525
526 /* Destination info */
527 ptr += 2;
528 cb->dst = dn_eth2dn(ptr);
529 if (memcmp(ptr, dn_hiord_addr, 4) != 0)
530 goto drop_it;
531 ptr += 6;
532
533
534 /* Source info */
535 ptr += 2;
536 cb->src = dn_eth2dn(ptr);
537 if (memcmp(ptr, dn_hiord_addr, 4) != 0)
538 goto drop_it;
539 ptr += 6;
540 /* Other junk */
541 ptr++;
542 cb->hops = *ptr++; /* Visit Count */
543
544 return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING, skb, skb->dev, NULL,
545 dn_route_rx_packet);
546
547 drop_it:
548 kfree_skb(skb);
549 return NET_RX_DROP;
550 }
551
552
553
dn_route_rx_short(struct sk_buff * skb)554 static int dn_route_rx_short(struct sk_buff *skb)
555 {
556 struct dn_skb_cb *cb = DN_SKB_CB(skb);
557 unsigned char *ptr = skb->data;
558
559 if (!pskb_may_pull(skb, 6)) /* 5 for short header + 1 for shortest nsp */
560 goto drop_it;
561
562 skb_pull(skb, 5);
563 skb_reset_transport_header(skb);
564
565 cb->dst = *(__le16 *)ptr;
566 ptr += 2;
567 cb->src = *(__le16 *)ptr;
568 ptr += 2;
569 cb->hops = *ptr & 0x3f;
570
571 return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING, skb, skb->dev, NULL,
572 dn_route_rx_packet);
573
574 drop_it:
575 kfree_skb(skb);
576 return NET_RX_DROP;
577 }
578
dn_route_discard(struct sk_buff * skb)579 static int dn_route_discard(struct sk_buff *skb)
580 {
581 /*
582 * I know we drop the packet here, but thats considered success in
583 * this case
584 */
585 kfree_skb(skb);
586 return NET_RX_SUCCESS;
587 }
588
dn_route_ptp_hello(struct sk_buff * skb)589 static int dn_route_ptp_hello(struct sk_buff *skb)
590 {
591 dn_dev_hello(skb);
592 dn_neigh_pointopoint_hello(skb);
593 return NET_RX_SUCCESS;
594 }
595
dn_route_rcv(struct sk_buff * skb,struct net_device * dev,struct packet_type * pt,struct net_device * orig_dev)596 int dn_route_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
597 {
598 struct dn_skb_cb *cb;
599 unsigned char flags = 0;
600 __u16 len = le16_to_cpu(*(__le16 *)skb->data);
601 struct dn_dev *dn = rcu_dereference(dev->dn_ptr);
602 unsigned char padlen = 0;
603
604 if (!net_eq(dev_net(dev), &init_net))
605 goto dump_it;
606
607 if (dn == NULL)
608 goto dump_it;
609
610 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
611 goto out;
612
613 if (!pskb_may_pull(skb, 3))
614 goto dump_it;
615
616 skb_pull(skb, 2);
617
618 if (len > skb->len)
619 goto dump_it;
620
621 skb_trim(skb, len);
622
623 flags = *skb->data;
624
625 cb = DN_SKB_CB(skb);
626 cb->stamp = jiffies;
627 cb->iif = dev->ifindex;
628
629 /*
630 * If we have padding, remove it.
631 */
632 if (flags & DN_RT_F_PF) {
633 padlen = flags & ~DN_RT_F_PF;
634 if (!pskb_may_pull(skb, padlen + 1))
635 goto dump_it;
636 skb_pull(skb, padlen);
637 flags = *skb->data;
638 }
639
640 skb_reset_network_header(skb);
641
642 /*
643 * Weed out future version DECnet
644 */
645 if (flags & DN_RT_F_VER)
646 goto dump_it;
647
648 cb->rt_flags = flags;
649
650 if (decnet_debug_level & 1)
651 printk(KERN_DEBUG
652 "dn_route_rcv: got 0x%02x from %s [%d %d %d]\n",
653 (int)flags, (dev) ? dev->name : "???", len, skb->len,
654 padlen);
655
656 if (flags & DN_RT_PKT_CNTL) {
657 if (unlikely(skb_linearize(skb)))
658 goto dump_it;
659
660 switch (flags & DN_RT_CNTL_MSK) {
661 case DN_RT_PKT_INIT:
662 dn_dev_init_pkt(skb);
663 break;
664 case DN_RT_PKT_VERI:
665 dn_dev_veri_pkt(skb);
666 break;
667 }
668
669 if (dn->parms.state != DN_DEV_S_RU)
670 goto dump_it;
671
672 switch (flags & DN_RT_CNTL_MSK) {
673 case DN_RT_PKT_HELO:
674 return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
675 skb, skb->dev, NULL,
676 dn_route_ptp_hello);
677
678 case DN_RT_PKT_L1RT:
679 case DN_RT_PKT_L2RT:
680 return NF_HOOK(NFPROTO_DECNET, NF_DN_ROUTE,
681 skb, skb->dev, NULL,
682 dn_route_discard);
683 case DN_RT_PKT_ERTH:
684 return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
685 skb, skb->dev, NULL,
686 dn_neigh_router_hello);
687
688 case DN_RT_PKT_EEDH:
689 return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
690 skb, skb->dev, NULL,
691 dn_neigh_endnode_hello);
692 }
693 } else {
694 if (dn->parms.state != DN_DEV_S_RU)
695 goto dump_it;
696
697 skb_pull(skb, 1); /* Pull flags */
698
699 switch (flags & DN_RT_PKT_MSK) {
700 case DN_RT_PKT_LONG:
701 return dn_route_rx_long(skb);
702 case DN_RT_PKT_SHORT:
703 return dn_route_rx_short(skb);
704 }
705 }
706
707 dump_it:
708 kfree_skb(skb);
709 out:
710 return NET_RX_DROP;
711 }
712
dn_to_neigh_output(struct sk_buff * skb)713 static int dn_to_neigh_output(struct sk_buff *skb)
714 {
715 struct dst_entry *dst = skb_dst(skb);
716 struct neighbour *n = dst_get_neighbour_noref(dst);
717
718 return n->output(n, skb);
719 }
720
dn_output(struct sk_buff * skb)721 static int dn_output(struct sk_buff *skb)
722 {
723 struct dst_entry *dst = skb_dst(skb);
724 struct dn_route *rt = (struct dn_route *)dst;
725 struct net_device *dev = dst->dev;
726 struct dn_skb_cb *cb = DN_SKB_CB(skb);
727 struct neighbour *neigh;
728
729 int err = -EINVAL;
730
731 if ((neigh = dst_get_neighbour_noref(dst)) == NULL)
732 goto error;
733
734 skb->dev = dev;
735
736 cb->src = rt->rt_saddr;
737 cb->dst = rt->rt_daddr;
738
739 /*
740 * Always set the Intra-Ethernet bit on all outgoing packets
741 * originated on this node. Only valid flag from upper layers
742 * is return-to-sender-requested. Set hop count to 0 too.
743 */
744 cb->rt_flags &= ~DN_RT_F_RQR;
745 cb->rt_flags |= DN_RT_F_IE;
746 cb->hops = 0;
747
748 return NF_HOOK(NFPROTO_DECNET, NF_DN_LOCAL_OUT, skb, NULL, dev,
749 dn_to_neigh_output);
750
751 error:
752 if (net_ratelimit())
753 printk(KERN_DEBUG "dn_output: This should not happen\n");
754
755 kfree_skb(skb);
756
757 return err;
758 }
759
dn_forward(struct sk_buff * skb)760 static int dn_forward(struct sk_buff *skb)
761 {
762 struct dn_skb_cb *cb = DN_SKB_CB(skb);
763 struct dst_entry *dst = skb_dst(skb);
764 struct dn_dev *dn_db = rcu_dereference(dst->dev->dn_ptr);
765 struct dn_route *rt;
766 int header_len;
767 #ifdef CONFIG_NETFILTER
768 struct net_device *dev = skb->dev;
769 #endif
770
771 if (skb->pkt_type != PACKET_HOST)
772 goto drop;
773
774 /* Ensure that we have enough space for headers */
775 rt = (struct dn_route *)skb_dst(skb);
776 header_len = dn_db->use_long ? 21 : 6;
777 if (skb_cow(skb, LL_RESERVED_SPACE(rt->dst.dev)+header_len))
778 goto drop;
779
780 /*
781 * Hop count exceeded.
782 */
783 if (++cb->hops > 30)
784 goto drop;
785
786 skb->dev = rt->dst.dev;
787
788 /*
789 * If packet goes out same interface it came in on, then set
790 * the Intra-Ethernet bit. This has no effect for short
791 * packets, so we don't need to test for them here.
792 */
793 cb->rt_flags &= ~DN_RT_F_IE;
794 if (rt->rt_flags & RTCF_DOREDIRECT)
795 cb->rt_flags |= DN_RT_F_IE;
796
797 return NF_HOOK(NFPROTO_DECNET, NF_DN_FORWARD, skb, dev, skb->dev,
798 dn_to_neigh_output);
799
800 drop:
801 kfree_skb(skb);
802 return NET_RX_DROP;
803 }
804
805 /*
806 * Used to catch bugs. This should never normally get
807 * called.
808 */
dn_rt_bug(struct sk_buff * skb)809 static int dn_rt_bug(struct sk_buff *skb)
810 {
811 if (net_ratelimit()) {
812 struct dn_skb_cb *cb = DN_SKB_CB(skb);
813
814 printk(KERN_DEBUG "dn_rt_bug: skb from:%04x to:%04x\n",
815 le16_to_cpu(cb->src), le16_to_cpu(cb->dst));
816 }
817
818 kfree_skb(skb);
819
820 return NET_RX_DROP;
821 }
822
dn_dst_default_advmss(const struct dst_entry * dst)823 static unsigned int dn_dst_default_advmss(const struct dst_entry *dst)
824 {
825 return dn_mss_from_pmtu(dst->dev, dst_mtu(dst));
826 }
827
dn_dst_mtu(const struct dst_entry * dst)828 static unsigned int dn_dst_mtu(const struct dst_entry *dst)
829 {
830 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
831
832 return mtu ? : dst->dev->mtu;
833 }
834
dn_dst_neigh_lookup(const struct dst_entry * dst,const void * daddr)835 static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst, const void *daddr)
836 {
837 return __neigh_lookup_errno(&dn_neigh_table, daddr, dst->dev);
838 }
839
dn_rt_set_next_hop(struct dn_route * rt,struct dn_fib_res * res)840 static int dn_rt_set_next_hop(struct dn_route *rt, struct dn_fib_res *res)
841 {
842 struct dn_fib_info *fi = res->fi;
843 struct net_device *dev = rt->dst.dev;
844 unsigned int mss_metric;
845 struct neighbour *n;
846
847 if (fi) {
848 if (DN_FIB_RES_GW(*res) &&
849 DN_FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
850 rt->rt_gateway = DN_FIB_RES_GW(*res);
851 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
852 }
853 rt->rt_type = res->type;
854
855 if (dev != NULL && dst_get_neighbour_noref(&rt->dst) == NULL) {
856 n = __neigh_lookup_errno(&dn_neigh_table, &rt->rt_gateway, dev);
857 if (IS_ERR(n))
858 return PTR_ERR(n);
859 dst_set_neighbour(&rt->dst, n);
860 }
861
862 if (dst_metric(&rt->dst, RTAX_MTU) > rt->dst.dev->mtu)
863 dst_metric_set(&rt->dst, RTAX_MTU, rt->dst.dev->mtu);
864 mss_metric = dst_metric_raw(&rt->dst, RTAX_ADVMSS);
865 if (mss_metric) {
866 unsigned int mss = dn_mss_from_pmtu(dev, dst_mtu(&rt->dst));
867 if (mss_metric > mss)
868 dst_metric_set(&rt->dst, RTAX_ADVMSS, mss);
869 }
870 return 0;
871 }
872
dn_match_addr(__le16 addr1,__le16 addr2)873 static inline int dn_match_addr(__le16 addr1, __le16 addr2)
874 {
875 __u16 tmp = le16_to_cpu(addr1) ^ le16_to_cpu(addr2);
876 int match = 16;
877 while(tmp) {
878 tmp >>= 1;
879 match--;
880 }
881 return match;
882 }
883
dnet_select_source(const struct net_device * dev,__le16 daddr,int scope)884 static __le16 dnet_select_source(const struct net_device *dev, __le16 daddr, int scope)
885 {
886 __le16 saddr = 0;
887 struct dn_dev *dn_db;
888 struct dn_ifaddr *ifa;
889 int best_match = 0;
890 int ret;
891
892 rcu_read_lock();
893 dn_db = rcu_dereference(dev->dn_ptr);
894 for (ifa = rcu_dereference(dn_db->ifa_list);
895 ifa != NULL;
896 ifa = rcu_dereference(ifa->ifa_next)) {
897 if (ifa->ifa_scope > scope)
898 continue;
899 if (!daddr) {
900 saddr = ifa->ifa_local;
901 break;
902 }
903 ret = dn_match_addr(daddr, ifa->ifa_local);
904 if (ret > best_match)
905 saddr = ifa->ifa_local;
906 if (best_match == 0)
907 saddr = ifa->ifa_local;
908 }
909 rcu_read_unlock();
910
911 return saddr;
912 }
913
__dn_fib_res_prefsrc(struct dn_fib_res * res)914 static inline __le16 __dn_fib_res_prefsrc(struct dn_fib_res *res)
915 {
916 return dnet_select_source(DN_FIB_RES_DEV(*res), DN_FIB_RES_GW(*res), res->scope);
917 }
918
dn_fib_rules_map_destination(__le16 daddr,struct dn_fib_res * res)919 static inline __le16 dn_fib_rules_map_destination(__le16 daddr, struct dn_fib_res *res)
920 {
921 __le16 mask = dnet_make_mask(res->prefixlen);
922 return (daddr&~mask)|res->fi->fib_nh->nh_gw;
923 }
924
dn_route_output_slow(struct dst_entry ** pprt,const struct flowidn * oldflp,int try_hard)925 static int dn_route_output_slow(struct dst_entry **pprt, const struct flowidn *oldflp, int try_hard)
926 {
927 struct flowidn fld = {
928 .daddr = oldflp->daddr,
929 .saddr = oldflp->saddr,
930 .flowidn_scope = RT_SCOPE_UNIVERSE,
931 .flowidn_mark = oldflp->flowidn_mark,
932 .flowidn_iif = init_net.loopback_dev->ifindex,
933 .flowidn_oif = oldflp->flowidn_oif,
934 };
935 struct dn_route *rt = NULL;
936 struct net_device *dev_out = NULL, *dev;
937 struct neighbour *neigh = NULL;
938 unsigned hash;
939 unsigned flags = 0;
940 struct dn_fib_res res = { .fi = NULL, .type = RTN_UNICAST };
941 int err;
942 int free_res = 0;
943 __le16 gateway = 0;
944
945 if (decnet_debug_level & 16)
946 printk(KERN_DEBUG
947 "dn_route_output_slow: dst=%04x src=%04x mark=%d"
948 " iif=%d oif=%d\n", le16_to_cpu(oldflp->daddr),
949 le16_to_cpu(oldflp->saddr),
950 oldflp->flowidn_mark, init_net.loopback_dev->ifindex,
951 oldflp->flowidn_oif);
952
953 /* If we have an output interface, verify its a DECnet device */
954 if (oldflp->flowidn_oif) {
955 dev_out = dev_get_by_index(&init_net, oldflp->flowidn_oif);
956 err = -ENODEV;
957 if (dev_out && dev_out->dn_ptr == NULL) {
958 dev_put(dev_out);
959 dev_out = NULL;
960 }
961 if (dev_out == NULL)
962 goto out;
963 }
964
965 /* If we have a source address, verify that its a local address */
966 if (oldflp->saddr) {
967 err = -EADDRNOTAVAIL;
968
969 if (dev_out) {
970 if (dn_dev_islocal(dev_out, oldflp->saddr))
971 goto source_ok;
972 dev_put(dev_out);
973 goto out;
974 }
975 rcu_read_lock();
976 for_each_netdev_rcu(&init_net, dev) {
977 if (!dev->dn_ptr)
978 continue;
979 if (!dn_dev_islocal(dev, oldflp->saddr))
980 continue;
981 if ((dev->flags & IFF_LOOPBACK) &&
982 oldflp->daddr &&
983 !dn_dev_islocal(dev, oldflp->daddr))
984 continue;
985
986 dev_out = dev;
987 break;
988 }
989 rcu_read_unlock();
990 if (dev_out == NULL)
991 goto out;
992 dev_hold(dev_out);
993 source_ok:
994 ;
995 }
996
997 /* No destination? Assume its local */
998 if (!fld.daddr) {
999 fld.daddr = fld.saddr;
1000
1001 err = -EADDRNOTAVAIL;
1002 if (dev_out)
1003 dev_put(dev_out);
1004 dev_out = init_net.loopback_dev;
1005 dev_hold(dev_out);
1006 if (!fld.daddr) {
1007 fld.daddr =
1008 fld.saddr = dnet_select_source(dev_out, 0,
1009 RT_SCOPE_HOST);
1010 if (!fld.daddr)
1011 goto out;
1012 }
1013 fld.flowidn_oif = init_net.loopback_dev->ifindex;
1014 res.type = RTN_LOCAL;
1015 goto make_route;
1016 }
1017
1018 if (decnet_debug_level & 16)
1019 printk(KERN_DEBUG
1020 "dn_route_output_slow: initial checks complete."
1021 " dst=%o4x src=%04x oif=%d try_hard=%d\n",
1022 le16_to_cpu(fld.daddr), le16_to_cpu(fld.saddr),
1023 fld.flowidn_oif, try_hard);
1024
1025 /*
1026 * N.B. If the kernel is compiled without router support then
1027 * dn_fib_lookup() will evaluate to non-zero so this if () block
1028 * will always be executed.
1029 */
1030 err = -ESRCH;
1031 if (try_hard || (err = dn_fib_lookup(&fld, &res)) != 0) {
1032 struct dn_dev *dn_db;
1033 if (err != -ESRCH)
1034 goto out;
1035 /*
1036 * Here the fallback is basically the standard algorithm for
1037 * routing in endnodes which is described in the DECnet routing
1038 * docs
1039 *
1040 * If we are not trying hard, look in neighbour cache.
1041 * The result is tested to ensure that if a specific output
1042 * device/source address was requested, then we honour that
1043 * here
1044 */
1045 if (!try_hard) {
1046 neigh = neigh_lookup_nodev(&dn_neigh_table, &init_net, &fld.daddr);
1047 if (neigh) {
1048 if ((oldflp->flowidn_oif &&
1049 (neigh->dev->ifindex != oldflp->flowidn_oif)) ||
1050 (oldflp->saddr &&
1051 (!dn_dev_islocal(neigh->dev,
1052 oldflp->saddr)))) {
1053 neigh_release(neigh);
1054 neigh = NULL;
1055 } else {
1056 if (dev_out)
1057 dev_put(dev_out);
1058 if (dn_dev_islocal(neigh->dev, fld.daddr)) {
1059 dev_out = init_net.loopback_dev;
1060 res.type = RTN_LOCAL;
1061 } else {
1062 dev_out = neigh->dev;
1063 }
1064 dev_hold(dev_out);
1065 goto select_source;
1066 }
1067 }
1068 }
1069
1070 /* Not there? Perhaps its a local address */
1071 if (dev_out == NULL)
1072 dev_out = dn_dev_get_default();
1073 err = -ENODEV;
1074 if (dev_out == NULL)
1075 goto out;
1076 dn_db = rcu_dereference_raw(dev_out->dn_ptr);
1077 /* Possible improvement - check all devices for local addr */
1078 if (dn_dev_islocal(dev_out, fld.daddr)) {
1079 dev_put(dev_out);
1080 dev_out = init_net.loopback_dev;
1081 dev_hold(dev_out);
1082 res.type = RTN_LOCAL;
1083 goto select_source;
1084 }
1085 /* Not local either.... try sending it to the default router */
1086 neigh = neigh_clone(dn_db->router);
1087 BUG_ON(neigh && neigh->dev != dev_out);
1088
1089 /* Ok then, we assume its directly connected and move on */
1090 select_source:
1091 if (neigh)
1092 gateway = ((struct dn_neigh *)neigh)->addr;
1093 if (gateway == 0)
1094 gateway = fld.daddr;
1095 if (fld.saddr == 0) {
1096 fld.saddr = dnet_select_source(dev_out, gateway,
1097 res.type == RTN_LOCAL ?
1098 RT_SCOPE_HOST :
1099 RT_SCOPE_LINK);
1100 if (fld.saddr == 0 && res.type != RTN_LOCAL)
1101 goto e_addr;
1102 }
1103 fld.flowidn_oif = dev_out->ifindex;
1104 goto make_route;
1105 }
1106 free_res = 1;
1107
1108 if (res.type == RTN_NAT)
1109 goto e_inval;
1110
1111 if (res.type == RTN_LOCAL) {
1112 if (!fld.saddr)
1113 fld.saddr = fld.daddr;
1114 if (dev_out)
1115 dev_put(dev_out);
1116 dev_out = init_net.loopback_dev;
1117 dev_hold(dev_out);
1118 fld.flowidn_oif = dev_out->ifindex;
1119 if (res.fi)
1120 dn_fib_info_put(res.fi);
1121 res.fi = NULL;
1122 goto make_route;
1123 }
1124
1125 if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1126 dn_fib_select_multipath(&fld, &res);
1127
1128 /*
1129 * We could add some logic to deal with default routes here and
1130 * get rid of some of the special casing above.
1131 */
1132
1133 if (!fld.saddr)
1134 fld.saddr = DN_FIB_RES_PREFSRC(res);
1135
1136 if (dev_out)
1137 dev_put(dev_out);
1138 dev_out = DN_FIB_RES_DEV(res);
1139 dev_hold(dev_out);
1140 fld.flowidn_oif = dev_out->ifindex;
1141 gateway = DN_FIB_RES_GW(res);
1142
1143 make_route:
1144 if (dev_out->flags & IFF_LOOPBACK)
1145 flags |= RTCF_LOCAL;
1146
1147 rt = dst_alloc(&dn_dst_ops, dev_out, 1, 0, DST_HOST);
1148 if (rt == NULL)
1149 goto e_nobufs;
1150
1151 memset(&rt->fld, 0, sizeof(rt->fld));
1152 rt->fld.saddr = oldflp->saddr;
1153 rt->fld.daddr = oldflp->daddr;
1154 rt->fld.flowidn_oif = oldflp->flowidn_oif;
1155 rt->fld.flowidn_iif = 0;
1156 rt->fld.flowidn_mark = oldflp->flowidn_mark;
1157
1158 rt->rt_saddr = fld.saddr;
1159 rt->rt_daddr = fld.daddr;
1160 rt->rt_gateway = gateway ? gateway : fld.daddr;
1161 rt->rt_local_src = fld.saddr;
1162
1163 rt->rt_dst_map = fld.daddr;
1164 rt->rt_src_map = fld.saddr;
1165
1166 dst_set_neighbour(&rt->dst, neigh);
1167 neigh = NULL;
1168
1169 rt->dst.lastuse = jiffies;
1170 rt->dst.output = dn_output;
1171 rt->dst.input = dn_rt_bug;
1172 rt->rt_flags = flags;
1173 if (flags & RTCF_LOCAL)
1174 rt->dst.input = dn_nsp_rx;
1175
1176 err = dn_rt_set_next_hop(rt, &res);
1177 if (err)
1178 goto e_neighbour;
1179
1180 hash = dn_hash(rt->fld.saddr, rt->fld.daddr);
1181 dn_insert_route(rt, hash, (struct dn_route **)pprt);
1182
1183 done:
1184 if (neigh)
1185 neigh_release(neigh);
1186 if (free_res)
1187 dn_fib_res_put(&res);
1188 if (dev_out)
1189 dev_put(dev_out);
1190 out:
1191 return err;
1192
1193 e_addr:
1194 err = -EADDRNOTAVAIL;
1195 goto done;
1196 e_inval:
1197 err = -EINVAL;
1198 goto done;
1199 e_nobufs:
1200 err = -ENOBUFS;
1201 goto done;
1202 e_neighbour:
1203 dst_free(&rt->dst);
1204 goto e_nobufs;
1205 }
1206
1207
1208 /*
1209 * N.B. The flags may be moved into the flowi at some future stage.
1210 */
__dn_route_output_key(struct dst_entry ** pprt,const struct flowidn * flp,int flags)1211 static int __dn_route_output_key(struct dst_entry **pprt, const struct flowidn *flp, int flags)
1212 {
1213 unsigned hash = dn_hash(flp->saddr, flp->daddr);
1214 struct dn_route *rt = NULL;
1215
1216 if (!(flags & MSG_TRYHARD)) {
1217 rcu_read_lock_bh();
1218 for (rt = rcu_dereference_bh(dn_rt_hash_table[hash].chain); rt;
1219 rt = rcu_dereference_bh(rt->dst.dn_next)) {
1220 if ((flp->daddr == rt->fld.daddr) &&
1221 (flp->saddr == rt->fld.saddr) &&
1222 (flp->flowidn_mark == rt->fld.flowidn_mark) &&
1223 dn_is_output_route(rt) &&
1224 (rt->fld.flowidn_oif == flp->flowidn_oif)) {
1225 dst_use(&rt->dst, jiffies);
1226 rcu_read_unlock_bh();
1227 *pprt = &rt->dst;
1228 return 0;
1229 }
1230 }
1231 rcu_read_unlock_bh();
1232 }
1233
1234 return dn_route_output_slow(pprt, flp, flags);
1235 }
1236
dn_route_output_key(struct dst_entry ** pprt,struct flowidn * flp,int flags)1237 static int dn_route_output_key(struct dst_entry **pprt, struct flowidn *flp, int flags)
1238 {
1239 int err;
1240
1241 err = __dn_route_output_key(pprt, flp, flags);
1242 if (err == 0 && flp->flowidn_proto) {
1243 *pprt = xfrm_lookup(&init_net, *pprt,
1244 flowidn_to_flowi(flp), NULL, 0);
1245 if (IS_ERR(*pprt)) {
1246 err = PTR_ERR(*pprt);
1247 *pprt = NULL;
1248 }
1249 }
1250 return err;
1251 }
1252
dn_route_output_sock(struct dst_entry ** pprt,struct flowidn * fl,struct sock * sk,int flags)1253 int dn_route_output_sock(struct dst_entry **pprt, struct flowidn *fl, struct sock *sk, int flags)
1254 {
1255 int err;
1256
1257 err = __dn_route_output_key(pprt, fl, flags & MSG_TRYHARD);
1258 if (err == 0 && fl->flowidn_proto) {
1259 if (!(flags & MSG_DONTWAIT))
1260 fl->flowidn_flags |= FLOWI_FLAG_CAN_SLEEP;
1261 *pprt = xfrm_lookup(&init_net, *pprt,
1262 flowidn_to_flowi(fl), sk, 0);
1263 if (IS_ERR(*pprt)) {
1264 err = PTR_ERR(*pprt);
1265 *pprt = NULL;
1266 }
1267 }
1268 return err;
1269 }
1270
dn_route_input_slow(struct sk_buff * skb)1271 static int dn_route_input_slow(struct sk_buff *skb)
1272 {
1273 struct dn_route *rt = NULL;
1274 struct dn_skb_cb *cb = DN_SKB_CB(skb);
1275 struct net_device *in_dev = skb->dev;
1276 struct net_device *out_dev = NULL;
1277 struct dn_dev *dn_db;
1278 struct neighbour *neigh = NULL;
1279 unsigned hash;
1280 int flags = 0;
1281 __le16 gateway = 0;
1282 __le16 local_src = 0;
1283 struct flowidn fld = {
1284 .daddr = cb->dst,
1285 .saddr = cb->src,
1286 .flowidn_scope = RT_SCOPE_UNIVERSE,
1287 .flowidn_mark = skb->mark,
1288 .flowidn_iif = skb->dev->ifindex,
1289 };
1290 struct dn_fib_res res = { .fi = NULL, .type = RTN_UNREACHABLE };
1291 int err = -EINVAL;
1292 int free_res = 0;
1293
1294 dev_hold(in_dev);
1295
1296 if ((dn_db = rcu_dereference(in_dev->dn_ptr)) == NULL)
1297 goto out;
1298
1299 /* Zero source addresses are not allowed */
1300 if (fld.saddr == 0)
1301 goto out;
1302
1303 /*
1304 * In this case we've just received a packet from a source
1305 * outside ourselves pretending to come from us. We don't
1306 * allow it any further to prevent routing loops, spoofing and
1307 * other nasties. Loopback packets already have the dst attached
1308 * so this only affects packets which have originated elsewhere.
1309 */
1310 err = -ENOTUNIQ;
1311 if (dn_dev_islocal(in_dev, cb->src))
1312 goto out;
1313
1314 err = dn_fib_lookup(&fld, &res);
1315 if (err) {
1316 if (err != -ESRCH)
1317 goto out;
1318 /*
1319 * Is the destination us ?
1320 */
1321 if (!dn_dev_islocal(in_dev, cb->dst))
1322 goto e_inval;
1323
1324 res.type = RTN_LOCAL;
1325 } else {
1326 __le16 src_map = fld.saddr;
1327 free_res = 1;
1328
1329 out_dev = DN_FIB_RES_DEV(res);
1330 if (out_dev == NULL) {
1331 if (net_ratelimit())
1332 printk(KERN_CRIT "Bug in dn_route_input_slow() "
1333 "No output device\n");
1334 goto e_inval;
1335 }
1336 dev_hold(out_dev);
1337
1338 if (res.r)
1339 src_map = fld.saddr; /* no NAT support for now */
1340
1341 gateway = DN_FIB_RES_GW(res);
1342 if (res.type == RTN_NAT) {
1343 fld.daddr = dn_fib_rules_map_destination(fld.daddr, &res);
1344 dn_fib_res_put(&res);
1345 free_res = 0;
1346 if (dn_fib_lookup(&fld, &res))
1347 goto e_inval;
1348 free_res = 1;
1349 if (res.type != RTN_UNICAST)
1350 goto e_inval;
1351 flags |= RTCF_DNAT;
1352 gateway = fld.daddr;
1353 }
1354 fld.saddr = src_map;
1355 }
1356
1357 switch(res.type) {
1358 case RTN_UNICAST:
1359 /*
1360 * Forwarding check here, we only check for forwarding
1361 * being turned off, if you want to only forward intra
1362 * area, its up to you to set the routing tables up
1363 * correctly.
1364 */
1365 if (dn_db->parms.forwarding == 0)
1366 goto e_inval;
1367
1368 if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1369 dn_fib_select_multipath(&fld, &res);
1370
1371 /*
1372 * Check for out_dev == in_dev. We use the RTCF_DOREDIRECT
1373 * flag as a hint to set the intra-ethernet bit when
1374 * forwarding. If we've got NAT in operation, we don't do
1375 * this optimisation.
1376 */
1377 if (out_dev == in_dev && !(flags & RTCF_NAT))
1378 flags |= RTCF_DOREDIRECT;
1379
1380 local_src = DN_FIB_RES_PREFSRC(res);
1381
1382 case RTN_BLACKHOLE:
1383 case RTN_UNREACHABLE:
1384 break;
1385 case RTN_LOCAL:
1386 flags |= RTCF_LOCAL;
1387 fld.saddr = cb->dst;
1388 fld.daddr = cb->src;
1389
1390 /* Routing tables gave us a gateway */
1391 if (gateway)
1392 goto make_route;
1393
1394 /* Packet was intra-ethernet, so we know its on-link */
1395 if (cb->rt_flags & DN_RT_F_IE) {
1396 gateway = cb->src;
1397 flags |= RTCF_DIRECTSRC;
1398 goto make_route;
1399 }
1400
1401 /* Use the default router if there is one */
1402 neigh = neigh_clone(dn_db->router);
1403 if (neigh) {
1404 gateway = ((struct dn_neigh *)neigh)->addr;
1405 goto make_route;
1406 }
1407
1408 /* Close eyes and pray */
1409 gateway = cb->src;
1410 flags |= RTCF_DIRECTSRC;
1411 goto make_route;
1412 default:
1413 goto e_inval;
1414 }
1415
1416 make_route:
1417 rt = dst_alloc(&dn_dst_ops, out_dev, 0, 0, DST_HOST);
1418 if (rt == NULL)
1419 goto e_nobufs;
1420
1421 memset(&rt->fld, 0, sizeof(rt->fld));
1422 rt->rt_saddr = fld.saddr;
1423 rt->rt_daddr = fld.daddr;
1424 rt->rt_gateway = fld.daddr;
1425 if (gateway)
1426 rt->rt_gateway = gateway;
1427 rt->rt_local_src = local_src ? local_src : rt->rt_saddr;
1428
1429 rt->rt_dst_map = fld.daddr;
1430 rt->rt_src_map = fld.saddr;
1431
1432 rt->fld.saddr = cb->src;
1433 rt->fld.daddr = cb->dst;
1434 rt->fld.flowidn_oif = 0;
1435 rt->fld.flowidn_iif = in_dev->ifindex;
1436 rt->fld.flowidn_mark = fld.flowidn_mark;
1437
1438 dst_set_neighbour(&rt->dst, neigh);
1439 rt->dst.lastuse = jiffies;
1440 rt->dst.output = dn_rt_bug;
1441 switch (res.type) {
1442 case RTN_UNICAST:
1443 rt->dst.input = dn_forward;
1444 break;
1445 case RTN_LOCAL:
1446 rt->dst.output = dn_output;
1447 rt->dst.input = dn_nsp_rx;
1448 rt->dst.dev = in_dev;
1449 flags |= RTCF_LOCAL;
1450 break;
1451 default:
1452 case RTN_UNREACHABLE:
1453 case RTN_BLACKHOLE:
1454 rt->dst.input = dst_discard;
1455 }
1456 rt->rt_flags = flags;
1457
1458 err = dn_rt_set_next_hop(rt, &res);
1459 if (err)
1460 goto e_neighbour;
1461
1462 hash = dn_hash(rt->fld.saddr, rt->fld.daddr);
1463 dn_insert_route(rt, hash, &rt);
1464 skb_dst_set(skb, &rt->dst);
1465
1466 done:
1467 if (neigh)
1468 neigh_release(neigh);
1469 if (free_res)
1470 dn_fib_res_put(&res);
1471 dev_put(in_dev);
1472 if (out_dev)
1473 dev_put(out_dev);
1474 out:
1475 return err;
1476
1477 e_inval:
1478 err = -EINVAL;
1479 goto done;
1480
1481 e_nobufs:
1482 err = -ENOBUFS;
1483 goto done;
1484
1485 e_neighbour:
1486 dst_free(&rt->dst);
1487 goto done;
1488 }
1489
dn_route_input(struct sk_buff * skb)1490 static int dn_route_input(struct sk_buff *skb)
1491 {
1492 struct dn_route *rt;
1493 struct dn_skb_cb *cb = DN_SKB_CB(skb);
1494 unsigned hash = dn_hash(cb->src, cb->dst);
1495
1496 if (skb_dst(skb))
1497 return 0;
1498
1499 rcu_read_lock();
1500 for(rt = rcu_dereference(dn_rt_hash_table[hash].chain); rt != NULL;
1501 rt = rcu_dereference(rt->dst.dn_next)) {
1502 if ((rt->fld.saddr == cb->src) &&
1503 (rt->fld.daddr == cb->dst) &&
1504 (rt->fld.flowidn_oif == 0) &&
1505 (rt->fld.flowidn_mark == skb->mark) &&
1506 (rt->fld.flowidn_iif == cb->iif)) {
1507 dst_use(&rt->dst, jiffies);
1508 rcu_read_unlock();
1509 skb_dst_set(skb, (struct dst_entry *)rt);
1510 return 0;
1511 }
1512 }
1513 rcu_read_unlock();
1514
1515 return dn_route_input_slow(skb);
1516 }
1517
dn_rt_fill_info(struct sk_buff * skb,u32 pid,u32 seq,int event,int nowait,unsigned int flags)1518 static int dn_rt_fill_info(struct sk_buff *skb, u32 pid, u32 seq,
1519 int event, int nowait, unsigned int flags)
1520 {
1521 struct dn_route *rt = (struct dn_route *)skb_dst(skb);
1522 struct rtmsg *r;
1523 struct nlmsghdr *nlh;
1524 unsigned char *b = skb_tail_pointer(skb);
1525 long expires;
1526
1527 nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*r), flags);
1528 r = NLMSG_DATA(nlh);
1529 r->rtm_family = AF_DECnet;
1530 r->rtm_dst_len = 16;
1531 r->rtm_src_len = 0;
1532 r->rtm_tos = 0;
1533 r->rtm_table = RT_TABLE_MAIN;
1534 RTA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
1535 r->rtm_type = rt->rt_type;
1536 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
1537 r->rtm_scope = RT_SCOPE_UNIVERSE;
1538 r->rtm_protocol = RTPROT_UNSPEC;
1539 if (rt->rt_flags & RTCF_NOTIFY)
1540 r->rtm_flags |= RTM_F_NOTIFY;
1541 RTA_PUT(skb, RTA_DST, 2, &rt->rt_daddr);
1542 if (rt->fld.saddr) {
1543 r->rtm_src_len = 16;
1544 RTA_PUT(skb, RTA_SRC, 2, &rt->fld.saddr);
1545 }
1546 if (rt->dst.dev)
1547 RTA_PUT(skb, RTA_OIF, sizeof(int), &rt->dst.dev->ifindex);
1548 /*
1549 * Note to self - change this if input routes reverse direction when
1550 * they deal only with inputs and not with replies like they do
1551 * currently.
1552 */
1553 RTA_PUT(skb, RTA_PREFSRC, 2, &rt->rt_local_src);
1554 if (rt->rt_daddr != rt->rt_gateway)
1555 RTA_PUT(skb, RTA_GATEWAY, 2, &rt->rt_gateway);
1556 if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
1557 goto rtattr_failure;
1558 expires = rt->dst.expires ? rt->dst.expires - jiffies : 0;
1559 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, 0, 0, expires,
1560 rt->dst.error) < 0)
1561 goto rtattr_failure;
1562 if (dn_is_input_route(rt))
1563 RTA_PUT(skb, RTA_IIF, sizeof(int), &rt->fld.flowidn_iif);
1564
1565 nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1566 return skb->len;
1567
1568 nlmsg_failure:
1569 rtattr_failure:
1570 nlmsg_trim(skb, b);
1571 return -1;
1572 }
1573
1574 /*
1575 * This is called by both endnodes and routers now.
1576 */
dn_cache_getroute(struct sk_buff * in_skb,struct nlmsghdr * nlh,void * arg)1577 static int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, void *arg)
1578 {
1579 struct net *net = sock_net(in_skb->sk);
1580 struct rtattr **rta = arg;
1581 struct rtmsg *rtm = NLMSG_DATA(nlh);
1582 struct dn_route *rt = NULL;
1583 struct dn_skb_cb *cb;
1584 int err;
1585 struct sk_buff *skb;
1586 struct flowidn fld;
1587
1588 if (!net_eq(net, &init_net))
1589 return -EINVAL;
1590
1591 memset(&fld, 0, sizeof(fld));
1592 fld.flowidn_proto = DNPROTO_NSP;
1593
1594 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1595 if (skb == NULL)
1596 return -ENOBUFS;
1597 skb_reset_mac_header(skb);
1598 cb = DN_SKB_CB(skb);
1599
1600 if (rta[RTA_SRC-1])
1601 memcpy(&fld.saddr, RTA_DATA(rta[RTA_SRC-1]), 2);
1602 if (rta[RTA_DST-1])
1603 memcpy(&fld.daddr, RTA_DATA(rta[RTA_DST-1]), 2);
1604 if (rta[RTA_IIF-1])
1605 memcpy(&fld.flowidn_iif, RTA_DATA(rta[RTA_IIF-1]), sizeof(int));
1606
1607 if (fld.flowidn_iif) {
1608 struct net_device *dev;
1609 if ((dev = dev_get_by_index(&init_net, fld.flowidn_iif)) == NULL) {
1610 kfree_skb(skb);
1611 return -ENODEV;
1612 }
1613 if (!dev->dn_ptr) {
1614 dev_put(dev);
1615 kfree_skb(skb);
1616 return -ENODEV;
1617 }
1618 skb->protocol = htons(ETH_P_DNA_RT);
1619 skb->dev = dev;
1620 cb->src = fld.saddr;
1621 cb->dst = fld.daddr;
1622 local_bh_disable();
1623 err = dn_route_input(skb);
1624 local_bh_enable();
1625 memset(cb, 0, sizeof(struct dn_skb_cb));
1626 rt = (struct dn_route *)skb_dst(skb);
1627 if (!err && -rt->dst.error)
1628 err = rt->dst.error;
1629 } else {
1630 int oif = 0;
1631 if (rta[RTA_OIF - 1])
1632 memcpy(&oif, RTA_DATA(rta[RTA_OIF - 1]), sizeof(int));
1633 fld.flowidn_oif = oif;
1634 err = dn_route_output_key((struct dst_entry **)&rt, &fld, 0);
1635 }
1636
1637 if (skb->dev)
1638 dev_put(skb->dev);
1639 skb->dev = NULL;
1640 if (err)
1641 goto out_free;
1642 skb_dst_set(skb, &rt->dst);
1643 if (rtm->rtm_flags & RTM_F_NOTIFY)
1644 rt->rt_flags |= RTCF_NOTIFY;
1645
1646 err = dn_rt_fill_info(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, RTM_NEWROUTE, 0, 0);
1647
1648 if (err == 0)
1649 goto out_free;
1650 if (err < 0) {
1651 err = -EMSGSIZE;
1652 goto out_free;
1653 }
1654
1655 return rtnl_unicast(skb, &init_net, NETLINK_CB(in_skb).pid);
1656
1657 out_free:
1658 kfree_skb(skb);
1659 return err;
1660 }
1661
1662 /*
1663 * For routers, this is called from dn_fib_dump, but for endnodes its
1664 * called directly from the rtnetlink dispatch table.
1665 */
dn_cache_dump(struct sk_buff * skb,struct netlink_callback * cb)1666 int dn_cache_dump(struct sk_buff *skb, struct netlink_callback *cb)
1667 {
1668 struct net *net = sock_net(skb->sk);
1669 struct dn_route *rt;
1670 int h, s_h;
1671 int idx, s_idx;
1672
1673 if (!net_eq(net, &init_net))
1674 return 0;
1675
1676 if (NLMSG_PAYLOAD(cb->nlh, 0) < sizeof(struct rtmsg))
1677 return -EINVAL;
1678 if (!(((struct rtmsg *)NLMSG_DATA(cb->nlh))->rtm_flags&RTM_F_CLONED))
1679 return 0;
1680
1681 s_h = cb->args[0];
1682 s_idx = idx = cb->args[1];
1683 for(h = 0; h <= dn_rt_hash_mask; h++) {
1684 if (h < s_h)
1685 continue;
1686 if (h > s_h)
1687 s_idx = 0;
1688 rcu_read_lock_bh();
1689 for(rt = rcu_dereference_bh(dn_rt_hash_table[h].chain), idx = 0;
1690 rt;
1691 rt = rcu_dereference_bh(rt->dst.dn_next), idx++) {
1692 if (idx < s_idx)
1693 continue;
1694 skb_dst_set(skb, dst_clone(&rt->dst));
1695 if (dn_rt_fill_info(skb, NETLINK_CB(cb->skb).pid,
1696 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
1697 1, NLM_F_MULTI) <= 0) {
1698 skb_dst_drop(skb);
1699 rcu_read_unlock_bh();
1700 goto done;
1701 }
1702 skb_dst_drop(skb);
1703 }
1704 rcu_read_unlock_bh();
1705 }
1706
1707 done:
1708 cb->args[0] = h;
1709 cb->args[1] = idx;
1710 return skb->len;
1711 }
1712
1713 #ifdef CONFIG_PROC_FS
1714 struct dn_rt_cache_iter_state {
1715 int bucket;
1716 };
1717
dn_rt_cache_get_first(struct seq_file * seq)1718 static struct dn_route *dn_rt_cache_get_first(struct seq_file *seq)
1719 {
1720 struct dn_route *rt = NULL;
1721 struct dn_rt_cache_iter_state *s = seq->private;
1722
1723 for(s->bucket = dn_rt_hash_mask; s->bucket >= 0; --s->bucket) {
1724 rcu_read_lock_bh();
1725 rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1726 if (rt)
1727 break;
1728 rcu_read_unlock_bh();
1729 }
1730 return rt;
1731 }
1732
dn_rt_cache_get_next(struct seq_file * seq,struct dn_route * rt)1733 static struct dn_route *dn_rt_cache_get_next(struct seq_file *seq, struct dn_route *rt)
1734 {
1735 struct dn_rt_cache_iter_state *s = seq->private;
1736
1737 rt = rcu_dereference_bh(rt->dst.dn_next);
1738 while (!rt) {
1739 rcu_read_unlock_bh();
1740 if (--s->bucket < 0)
1741 break;
1742 rcu_read_lock_bh();
1743 rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1744 }
1745 return rt;
1746 }
1747
dn_rt_cache_seq_start(struct seq_file * seq,loff_t * pos)1748 static void *dn_rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
1749 {
1750 struct dn_route *rt = dn_rt_cache_get_first(seq);
1751
1752 if (rt) {
1753 while(*pos && (rt = dn_rt_cache_get_next(seq, rt)))
1754 --*pos;
1755 }
1756 return *pos ? NULL : rt;
1757 }
1758
dn_rt_cache_seq_next(struct seq_file * seq,void * v,loff_t * pos)1759 static void *dn_rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1760 {
1761 struct dn_route *rt = dn_rt_cache_get_next(seq, v);
1762 ++*pos;
1763 return rt;
1764 }
1765
dn_rt_cache_seq_stop(struct seq_file * seq,void * v)1766 static void dn_rt_cache_seq_stop(struct seq_file *seq, void *v)
1767 {
1768 if (v)
1769 rcu_read_unlock_bh();
1770 }
1771
dn_rt_cache_seq_show(struct seq_file * seq,void * v)1772 static int dn_rt_cache_seq_show(struct seq_file *seq, void *v)
1773 {
1774 struct dn_route *rt = v;
1775 char buf1[DN_ASCBUF_LEN], buf2[DN_ASCBUF_LEN];
1776
1777 seq_printf(seq, "%-8s %-7s %-7s %04d %04d %04d\n",
1778 rt->dst.dev ? rt->dst.dev->name : "*",
1779 dn_addr2asc(le16_to_cpu(rt->rt_daddr), buf1),
1780 dn_addr2asc(le16_to_cpu(rt->rt_saddr), buf2),
1781 atomic_read(&rt->dst.__refcnt),
1782 rt->dst.__use,
1783 (int) dst_metric(&rt->dst, RTAX_RTT));
1784 return 0;
1785 }
1786
1787 static const struct seq_operations dn_rt_cache_seq_ops = {
1788 .start = dn_rt_cache_seq_start,
1789 .next = dn_rt_cache_seq_next,
1790 .stop = dn_rt_cache_seq_stop,
1791 .show = dn_rt_cache_seq_show,
1792 };
1793
dn_rt_cache_seq_open(struct inode * inode,struct file * file)1794 static int dn_rt_cache_seq_open(struct inode *inode, struct file *file)
1795 {
1796 return seq_open_private(file, &dn_rt_cache_seq_ops,
1797 sizeof(struct dn_rt_cache_iter_state));
1798 }
1799
1800 static const struct file_operations dn_rt_cache_seq_fops = {
1801 .owner = THIS_MODULE,
1802 .open = dn_rt_cache_seq_open,
1803 .read = seq_read,
1804 .llseek = seq_lseek,
1805 .release = seq_release_private,
1806 };
1807
1808 #endif /* CONFIG_PROC_FS */
1809
dn_route_init(void)1810 void __init dn_route_init(void)
1811 {
1812 int i, goal, order;
1813
1814 dn_dst_ops.kmem_cachep =
1815 kmem_cache_create("dn_dst_cache", sizeof(struct dn_route), 0,
1816 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
1817 dst_entries_init(&dn_dst_ops);
1818 setup_timer(&dn_route_timer, dn_dst_check_expire, 0);
1819 dn_route_timer.expires = jiffies + decnet_dst_gc_interval * HZ;
1820 add_timer(&dn_route_timer);
1821
1822 goal = totalram_pages >> (26 - PAGE_SHIFT);
1823
1824 for(order = 0; (1UL << order) < goal; order++)
1825 /* NOTHING */;
1826
1827 /*
1828 * Only want 1024 entries max, since the table is very, very unlikely
1829 * to be larger than that.
1830 */
1831 while(order && ((((1UL << order) * PAGE_SIZE) /
1832 sizeof(struct dn_rt_hash_bucket)) >= 2048))
1833 order--;
1834
1835 do {
1836 dn_rt_hash_mask = (1UL << order) * PAGE_SIZE /
1837 sizeof(struct dn_rt_hash_bucket);
1838 while(dn_rt_hash_mask & (dn_rt_hash_mask - 1))
1839 dn_rt_hash_mask--;
1840 dn_rt_hash_table = (struct dn_rt_hash_bucket *)
1841 __get_free_pages(GFP_ATOMIC, order);
1842 } while (dn_rt_hash_table == NULL && --order > 0);
1843
1844 if (!dn_rt_hash_table)
1845 panic("Failed to allocate DECnet route cache hash table\n");
1846
1847 printk(KERN_INFO
1848 "DECnet: Routing cache hash table of %u buckets, %ldKbytes\n",
1849 dn_rt_hash_mask,
1850 (long)(dn_rt_hash_mask*sizeof(struct dn_rt_hash_bucket))/1024);
1851
1852 dn_rt_hash_mask--;
1853 for(i = 0; i <= dn_rt_hash_mask; i++) {
1854 spin_lock_init(&dn_rt_hash_table[i].lock);
1855 dn_rt_hash_table[i].chain = NULL;
1856 }
1857
1858 dn_dst_ops.gc_thresh = (dn_rt_hash_mask + 1);
1859
1860 proc_net_fops_create(&init_net, "decnet_cache", S_IRUGO, &dn_rt_cache_seq_fops);
1861
1862 #ifdef CONFIG_DECNET_ROUTER
1863 rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute,
1864 dn_fib_dump, NULL);
1865 #else
1866 rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute,
1867 dn_cache_dump, NULL);
1868 #endif
1869 }
1870
dn_route_cleanup(void)1871 void __exit dn_route_cleanup(void)
1872 {
1873 del_timer(&dn_route_timer);
1874 dn_run_flush(0);
1875
1876 proc_net_remove(&init_net, "decnet_cache");
1877 dst_entries_destroy(&dn_dst_ops);
1878 }
1879
1880