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