• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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 void dn_dst_ifdown(struct dst_entry *, struct net_device *dev, int how);
118 static struct dst_entry *dn_dst_negative_advice(struct dst_entry *);
119 static void dn_dst_link_failure(struct sk_buff *);
120 static void dn_dst_update_pmtu(struct dst_entry *dst, struct sock *sk,
121 			       struct sk_buff *skb , u32 mtu);
122 static void dn_dst_redirect(struct dst_entry *dst, struct sock *sk,
123 			    struct sk_buff *skb);
124 static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst,
125 					     struct sk_buff *skb,
126 					     const void *daddr);
127 static int dn_route_input(struct sk_buff *);
128 static void dn_run_flush(unsigned long dummy);
129 
130 static struct dn_rt_hash_bucket *dn_rt_hash_table;
131 static unsigned int dn_rt_hash_mask;
132 
133 static struct timer_list dn_route_timer;
134 static DEFINE_TIMER(dn_rt_flush_timer, dn_run_flush, 0, 0);
135 int decnet_dst_gc_interval = 2;
136 
137 static struct dst_ops dn_dst_ops = {
138 	.family =		PF_DECnet,
139 	.protocol =		cpu_to_be16(ETH_P_DNA_RT),
140 	.gc_thresh =		128,
141 	.gc =			dn_dst_gc,
142 	.check =		dn_dst_check,
143 	.default_advmss =	dn_dst_default_advmss,
144 	.mtu =			dn_dst_mtu,
145 	.cow_metrics =		dst_cow_metrics_generic,
146 	.destroy =		dn_dst_destroy,
147 	.ifdown =		dn_dst_ifdown,
148 	.negative_advice =	dn_dst_negative_advice,
149 	.link_failure =		dn_dst_link_failure,
150 	.update_pmtu =		dn_dst_update_pmtu,
151 	.redirect =		dn_dst_redirect,
152 	.neigh_lookup =		dn_dst_neigh_lookup,
153 };
154 
dn_dst_destroy(struct dst_entry * dst)155 static void dn_dst_destroy(struct dst_entry *dst)
156 {
157 	struct dn_route *rt = (struct dn_route *) dst;
158 
159 	if (rt->n)
160 		neigh_release(rt->n);
161 	dst_destroy_metrics_generic(dst);
162 }
163 
dn_dst_ifdown(struct dst_entry * dst,struct net_device * dev,int how)164 static void dn_dst_ifdown(struct dst_entry *dst, struct net_device *dev, int how)
165 {
166 	if (how) {
167 		struct dn_route *rt = (struct dn_route *) dst;
168 		struct neighbour *n = rt->n;
169 
170 		if (n && n->dev == dev) {
171 			n->dev = dev_net(dev)->loopback_dev;
172 			dev_hold(n->dev);
173 			dev_put(dev);
174 		}
175 	}
176 }
177 
dn_hash(__le16 src,__le16 dst)178 static __inline__ unsigned int dn_hash(__le16 src, __le16 dst)
179 {
180 	__u16 tmp = (__u16 __force)(src ^ dst);
181 	tmp ^= (tmp >> 3);
182 	tmp ^= (tmp >> 5);
183 	tmp ^= (tmp >> 10);
184 	return dn_rt_hash_mask & (unsigned int)tmp;
185 }
186 
dnrt_free(struct dn_route * rt)187 static inline void dnrt_free(struct dn_route *rt)
188 {
189 	call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
190 }
191 
dnrt_drop(struct dn_route * rt)192 static inline void dnrt_drop(struct dn_route *rt)
193 {
194 	dst_release(&rt->dst);
195 	call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
196 }
197 
dn_dst_check_expire(unsigned long dummy)198 static void dn_dst_check_expire(unsigned long dummy)
199 {
200 	int i;
201 	struct dn_route *rt;
202 	struct dn_route __rcu **rtp;
203 	unsigned long now = jiffies;
204 	unsigned long expire = 120 * HZ;
205 
206 	for (i = 0; i <= dn_rt_hash_mask; i++) {
207 		rtp = &dn_rt_hash_table[i].chain;
208 
209 		spin_lock(&dn_rt_hash_table[i].lock);
210 		while ((rt = rcu_dereference_protected(*rtp,
211 						lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) {
212 			if (atomic_read(&rt->dst.__refcnt) ||
213 					(now - rt->dst.lastuse) < expire) {
214 				rtp = &rt->dst.dn_next;
215 				continue;
216 			}
217 			*rtp = rt->dst.dn_next;
218 			rt->dst.dn_next = NULL;
219 			dnrt_free(rt);
220 		}
221 		spin_unlock(&dn_rt_hash_table[i].lock);
222 
223 		if ((jiffies - now) > 0)
224 			break;
225 	}
226 
227 	mod_timer(&dn_route_timer, now + decnet_dst_gc_interval * HZ);
228 }
229 
dn_dst_gc(struct dst_ops * ops)230 static int dn_dst_gc(struct dst_ops *ops)
231 {
232 	struct dn_route *rt;
233 	struct dn_route __rcu **rtp;
234 	int i;
235 	unsigned long now = jiffies;
236 	unsigned long expire = 10 * HZ;
237 
238 	for (i = 0; i <= dn_rt_hash_mask; i++) {
239 
240 		spin_lock_bh(&dn_rt_hash_table[i].lock);
241 		rtp = &dn_rt_hash_table[i].chain;
242 
243 		while ((rt = rcu_dereference_protected(*rtp,
244 						lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) {
245 			if (atomic_read(&rt->dst.__refcnt) ||
246 					(now - rt->dst.lastuse) < expire) {
247 				rtp = &rt->dst.dn_next;
248 				continue;
249 			}
250 			*rtp = rt->dst.dn_next;
251 			rt->dst.dn_next = NULL;
252 			dnrt_drop(rt);
253 			break;
254 		}
255 		spin_unlock_bh(&dn_rt_hash_table[i].lock);
256 	}
257 
258 	return 0;
259 }
260 
261 /*
262  * The decnet standards don't impose a particular minimum mtu, what they
263  * do insist on is that the routing layer accepts a datagram of at least
264  * 230 bytes long. Here we have to subtract the routing header length from
265  * 230 to get the minimum acceptable mtu. If there is no neighbour, then we
266  * assume the worst and use a long header size.
267  *
268  * We update both the mtu and the advertised mss (i.e. the segment size we
269  * advertise to the other end).
270  */
dn_dst_update_pmtu(struct dst_entry * dst,struct sock * sk,struct sk_buff * skb,u32 mtu)271 static void dn_dst_update_pmtu(struct dst_entry *dst, struct sock *sk,
272 			       struct sk_buff *skb, u32 mtu)
273 {
274 	struct dn_route *rt = (struct dn_route *) dst;
275 	struct neighbour *n = rt->n;
276 	u32 min_mtu = 230;
277 	struct dn_dev *dn;
278 
279 	dn = n ? rcu_dereference_raw(n->dev->dn_ptr) : NULL;
280 
281 	if (dn && dn->use_long == 0)
282 		min_mtu -= 6;
283 	else
284 		min_mtu -= 21;
285 
286 	if (dst_metric(dst, RTAX_MTU) > mtu && mtu >= min_mtu) {
287 		if (!(dst_metric_locked(dst, RTAX_MTU))) {
288 			dst_metric_set(dst, RTAX_MTU, mtu);
289 			dst_set_expires(dst, dn_rt_mtu_expires);
290 		}
291 		if (!(dst_metric_locked(dst, RTAX_ADVMSS))) {
292 			u32 mss = mtu - DN_MAX_NSP_DATA_HEADER;
293 			u32 existing_mss = dst_metric_raw(dst, RTAX_ADVMSS);
294 			if (!existing_mss || existing_mss > mss)
295 				dst_metric_set(dst, RTAX_ADVMSS, mss);
296 		}
297 	}
298 }
299 
dn_dst_redirect(struct dst_entry * dst,struct sock * sk,struct sk_buff * skb)300 static void dn_dst_redirect(struct dst_entry *dst, struct sock *sk,
301 			    struct sk_buff *skb)
302 {
303 }
304 
305 /*
306  * When a route has been marked obsolete. (e.g. routing cache flush)
307  */
dn_dst_check(struct dst_entry * dst,__u32 cookie)308 static struct dst_entry *dn_dst_check(struct dst_entry *dst, __u32 cookie)
309 {
310 	return NULL;
311 }
312 
dn_dst_negative_advice(struct dst_entry * dst)313 static struct dst_entry *dn_dst_negative_advice(struct dst_entry *dst)
314 {
315 	dst_release(dst);
316 	return NULL;
317 }
318 
dn_dst_link_failure(struct sk_buff * skb)319 static void dn_dst_link_failure(struct sk_buff *skb)
320 {
321 }
322 
compare_keys(struct flowidn * fl1,struct flowidn * fl2)323 static inline int compare_keys(struct flowidn *fl1, struct flowidn *fl2)
324 {
325 	return ((fl1->daddr ^ fl2->daddr) |
326 		(fl1->saddr ^ fl2->saddr) |
327 		(fl1->flowidn_mark ^ fl2->flowidn_mark) |
328 		(fl1->flowidn_scope ^ fl2->flowidn_scope) |
329 		(fl1->flowidn_oif ^ fl2->flowidn_oif) |
330 		(fl1->flowidn_iif ^ fl2->flowidn_iif)) == 0;
331 }
332 
dn_insert_route(struct dn_route * rt,unsigned int hash,struct dn_route ** rp)333 static int dn_insert_route(struct dn_route *rt, unsigned int hash, struct dn_route **rp)
334 {
335 	struct dn_route *rth;
336 	struct dn_route __rcu **rthp;
337 	unsigned long now = jiffies;
338 
339 	rthp = &dn_rt_hash_table[hash].chain;
340 
341 	spin_lock_bh(&dn_rt_hash_table[hash].lock);
342 	while ((rth = rcu_dereference_protected(*rthp,
343 						lockdep_is_held(&dn_rt_hash_table[hash].lock))) != NULL) {
344 		if (compare_keys(&rth->fld, &rt->fld)) {
345 			/* Put it first */
346 			*rthp = rth->dst.dn_next;
347 			rcu_assign_pointer(rth->dst.dn_next,
348 					   dn_rt_hash_table[hash].chain);
349 			rcu_assign_pointer(dn_rt_hash_table[hash].chain, rth);
350 
351 			dst_use(&rth->dst, now);
352 			spin_unlock_bh(&dn_rt_hash_table[hash].lock);
353 
354 			dnrt_drop(rt);
355 			*rp = rth;
356 			return 0;
357 		}
358 		rthp = &rth->dst.dn_next;
359 	}
360 
361 	rcu_assign_pointer(rt->dst.dn_next, dn_rt_hash_table[hash].chain);
362 	rcu_assign_pointer(dn_rt_hash_table[hash].chain, rt);
363 
364 	dst_use(&rt->dst, now);
365 	spin_unlock_bh(&dn_rt_hash_table[hash].lock);
366 	*rp = rt;
367 	return 0;
368 }
369 
dn_run_flush(unsigned long dummy)370 static void dn_run_flush(unsigned long dummy)
371 {
372 	int i;
373 	struct dn_route *rt, *next;
374 
375 	for (i = 0; i < dn_rt_hash_mask; i++) {
376 		spin_lock_bh(&dn_rt_hash_table[i].lock);
377 
378 		if ((rt = xchg((struct dn_route **)&dn_rt_hash_table[i].chain, NULL)) == NULL)
379 			goto nothing_to_declare;
380 
381 		for(; rt; rt = next) {
382 			next = rcu_dereference_raw(rt->dst.dn_next);
383 			RCU_INIT_POINTER(rt->dst.dn_next, NULL);
384 			dst_free((struct dst_entry *)rt);
385 		}
386 
387 nothing_to_declare:
388 		spin_unlock_bh(&dn_rt_hash_table[i].lock);
389 	}
390 }
391 
392 static DEFINE_SPINLOCK(dn_rt_flush_lock);
393 
dn_rt_cache_flush(int delay)394 void dn_rt_cache_flush(int delay)
395 {
396 	unsigned long now = jiffies;
397 	int user_mode = !in_interrupt();
398 
399 	if (delay < 0)
400 		delay = dn_rt_min_delay;
401 
402 	spin_lock_bh(&dn_rt_flush_lock);
403 
404 	if (del_timer(&dn_rt_flush_timer) && delay > 0 && dn_rt_deadline) {
405 		long tmo = (long)(dn_rt_deadline - now);
406 
407 		if (user_mode && tmo < dn_rt_max_delay - dn_rt_min_delay)
408 			tmo = 0;
409 
410 		if (delay > tmo)
411 			delay = tmo;
412 	}
413 
414 	if (delay <= 0) {
415 		spin_unlock_bh(&dn_rt_flush_lock);
416 		dn_run_flush(0);
417 		return;
418 	}
419 
420 	if (dn_rt_deadline == 0)
421 		dn_rt_deadline = now + dn_rt_max_delay;
422 
423 	dn_rt_flush_timer.expires = now + delay;
424 	add_timer(&dn_rt_flush_timer);
425 	spin_unlock_bh(&dn_rt_flush_lock);
426 }
427 
428 /**
429  * dn_return_short - Return a short packet to its sender
430  * @skb: The packet to return
431  *
432  */
dn_return_short(struct sk_buff * skb)433 static int dn_return_short(struct sk_buff *skb)
434 {
435 	struct dn_skb_cb *cb;
436 	unsigned char *ptr;
437 	__le16 *src;
438 	__le16 *dst;
439 
440 	/* Add back headers */
441 	skb_push(skb, skb->data - skb_network_header(skb));
442 
443 	if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
444 		return NET_RX_DROP;
445 
446 	cb = DN_SKB_CB(skb);
447 	/* Skip packet length and point to flags */
448 	ptr = skb->data + 2;
449 	*ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
450 
451 	dst = (__le16 *)ptr;
452 	ptr += 2;
453 	src = (__le16 *)ptr;
454 	ptr += 2;
455 	*ptr = 0; /* Zero hop count */
456 
457 	swap(*src, *dst);
458 
459 	skb->pkt_type = PACKET_OUTGOING;
460 	dn_rt_finish_output(skb, NULL, NULL);
461 	return NET_RX_SUCCESS;
462 }
463 
464 /**
465  * dn_return_long - Return a long packet to its sender
466  * @skb: The long format packet to return
467  *
468  */
dn_return_long(struct sk_buff * skb)469 static int dn_return_long(struct sk_buff *skb)
470 {
471 	struct dn_skb_cb *cb;
472 	unsigned char *ptr;
473 	unsigned char *src_addr, *dst_addr;
474 	unsigned char tmp[ETH_ALEN];
475 
476 	/* Add back all headers */
477 	skb_push(skb, skb->data - skb_network_header(skb));
478 
479 	if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
480 		return NET_RX_DROP;
481 
482 	cb = DN_SKB_CB(skb);
483 	/* Ignore packet length and point to flags */
484 	ptr = skb->data + 2;
485 
486 	/* Skip padding */
487 	if (*ptr & DN_RT_F_PF) {
488 		char padlen = (*ptr & ~DN_RT_F_PF);
489 		ptr += padlen;
490 	}
491 
492 	*ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
493 	ptr += 2;
494 	dst_addr = ptr;
495 	ptr += 8;
496 	src_addr = ptr;
497 	ptr += 6;
498 	*ptr = 0; /* Zero hop count */
499 
500 	/* Swap source and destination */
501 	memcpy(tmp, src_addr, ETH_ALEN);
502 	memcpy(src_addr, dst_addr, ETH_ALEN);
503 	memcpy(dst_addr, tmp, ETH_ALEN);
504 
505 	skb->pkt_type = PACKET_OUTGOING;
506 	dn_rt_finish_output(skb, dst_addr, src_addr);
507 	return NET_RX_SUCCESS;
508 }
509 
510 /**
511  * dn_route_rx_packet - Try and find a route for an incoming packet
512  * @skb: The packet to find a route for
513  *
514  * Returns: result of input function if route is found, error code otherwise
515  */
dn_route_rx_packet(struct sk_buff * skb)516 static int dn_route_rx_packet(struct sk_buff *skb)
517 {
518 	struct dn_skb_cb *cb;
519 	int err;
520 
521 	if ((err = dn_route_input(skb)) == 0)
522 		return dst_input(skb);
523 
524 	cb = DN_SKB_CB(skb);
525 	if (decnet_debug_level & 4) {
526 		char *devname = skb->dev ? skb->dev->name : "???";
527 
528 		printk(KERN_DEBUG
529 			"DECnet: dn_route_rx_packet: rt_flags=0x%02x dev=%s len=%d src=0x%04hx dst=0x%04hx err=%d type=%d\n",
530 			(int)cb->rt_flags, devname, skb->len,
531 			le16_to_cpu(cb->src), le16_to_cpu(cb->dst),
532 			err, skb->pkt_type);
533 	}
534 
535 	if ((skb->pkt_type == PACKET_HOST) && (cb->rt_flags & DN_RT_F_RQR)) {
536 		switch (cb->rt_flags & DN_RT_PKT_MSK) {
537 		case DN_RT_PKT_SHORT:
538 			return dn_return_short(skb);
539 		case DN_RT_PKT_LONG:
540 			return dn_return_long(skb);
541 		}
542 	}
543 
544 	kfree_skb(skb);
545 	return NET_RX_DROP;
546 }
547 
dn_route_rx_long(struct sk_buff * skb)548 static int dn_route_rx_long(struct sk_buff *skb)
549 {
550 	struct dn_skb_cb *cb = DN_SKB_CB(skb);
551 	unsigned char *ptr = skb->data;
552 
553 	if (!pskb_may_pull(skb, 21)) /* 20 for long header, 1 for shortest nsp */
554 		goto drop_it;
555 
556 	skb_pull(skb, 20);
557 	skb_reset_transport_header(skb);
558 
559 	/* Destination info */
560 	ptr += 2;
561 	cb->dst = dn_eth2dn(ptr);
562 	if (memcmp(ptr, dn_hiord_addr, 4) != 0)
563 		goto drop_it;
564 	ptr += 6;
565 
566 
567 	/* Source info */
568 	ptr += 2;
569 	cb->src = dn_eth2dn(ptr);
570 	if (memcmp(ptr, dn_hiord_addr, 4) != 0)
571 		goto drop_it;
572 	ptr += 6;
573 	/* Other junk */
574 	ptr++;
575 	cb->hops = *ptr++; /* Visit Count */
576 
577 	return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING, skb, skb->dev, NULL,
578 		       dn_route_rx_packet);
579 
580 drop_it:
581 	kfree_skb(skb);
582 	return NET_RX_DROP;
583 }
584 
585 
586 
dn_route_rx_short(struct sk_buff * skb)587 static int dn_route_rx_short(struct sk_buff *skb)
588 {
589 	struct dn_skb_cb *cb = DN_SKB_CB(skb);
590 	unsigned char *ptr = skb->data;
591 
592 	if (!pskb_may_pull(skb, 6)) /* 5 for short header + 1 for shortest nsp */
593 		goto drop_it;
594 
595 	skb_pull(skb, 5);
596 	skb_reset_transport_header(skb);
597 
598 	cb->dst = *(__le16 *)ptr;
599 	ptr += 2;
600 	cb->src = *(__le16 *)ptr;
601 	ptr += 2;
602 	cb->hops = *ptr & 0x3f;
603 
604 	return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING, skb, skb->dev, NULL,
605 		       dn_route_rx_packet);
606 
607 drop_it:
608 	kfree_skb(skb);
609 	return NET_RX_DROP;
610 }
611 
dn_route_discard(struct sk_buff * skb)612 static int dn_route_discard(struct sk_buff *skb)
613 {
614 	/*
615 	 * I know we drop the packet here, but thats considered success in
616 	 * this case
617 	 */
618 	kfree_skb(skb);
619 	return NET_RX_SUCCESS;
620 }
621 
dn_route_ptp_hello(struct sk_buff * skb)622 static int dn_route_ptp_hello(struct sk_buff *skb)
623 {
624 	dn_dev_hello(skb);
625 	dn_neigh_pointopoint_hello(skb);
626 	return NET_RX_SUCCESS;
627 }
628 
dn_route_rcv(struct sk_buff * skb,struct net_device * dev,struct packet_type * pt,struct net_device * orig_dev)629 int dn_route_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
630 {
631 	struct dn_skb_cb *cb;
632 	unsigned char flags = 0;
633 	__u16 len = le16_to_cpu(*(__le16 *)skb->data);
634 	struct dn_dev *dn = rcu_dereference(dev->dn_ptr);
635 	unsigned char padlen = 0;
636 
637 	if (!net_eq(dev_net(dev), &init_net))
638 		goto dump_it;
639 
640 	if (dn == NULL)
641 		goto dump_it;
642 
643 	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
644 		goto out;
645 
646 	if (!pskb_may_pull(skb, 3))
647 		goto dump_it;
648 
649 	skb_pull(skb, 2);
650 
651 	if (len > skb->len)
652 		goto dump_it;
653 
654 	skb_trim(skb, len);
655 
656 	flags = *skb->data;
657 
658 	cb = DN_SKB_CB(skb);
659 	cb->stamp = jiffies;
660 	cb->iif = dev->ifindex;
661 
662 	/*
663 	 * If we have padding, remove it.
664 	 */
665 	if (flags & DN_RT_F_PF) {
666 		padlen = flags & ~DN_RT_F_PF;
667 		if (!pskb_may_pull(skb, padlen + 1))
668 			goto dump_it;
669 		skb_pull(skb, padlen);
670 		flags = *skb->data;
671 	}
672 
673 	skb_reset_network_header(skb);
674 
675 	/*
676 	 * Weed out future version DECnet
677 	 */
678 	if (flags & DN_RT_F_VER)
679 		goto dump_it;
680 
681 	cb->rt_flags = flags;
682 
683 	if (decnet_debug_level & 1)
684 		printk(KERN_DEBUG
685 			"dn_route_rcv: got 0x%02x from %s [%d %d %d]\n",
686 			(int)flags, (dev) ? dev->name : "???", len, skb->len,
687 			padlen);
688 
689 	if (flags & DN_RT_PKT_CNTL) {
690 		if (unlikely(skb_linearize(skb)))
691 			goto dump_it;
692 
693 		switch (flags & DN_RT_CNTL_MSK) {
694 		case DN_RT_PKT_INIT:
695 			dn_dev_init_pkt(skb);
696 			break;
697 		case DN_RT_PKT_VERI:
698 			dn_dev_veri_pkt(skb);
699 			break;
700 		}
701 
702 		if (dn->parms.state != DN_DEV_S_RU)
703 			goto dump_it;
704 
705 		switch (flags & DN_RT_CNTL_MSK) {
706 		case DN_RT_PKT_HELO:
707 			return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
708 				       skb, skb->dev, NULL,
709 				       dn_route_ptp_hello);
710 
711 		case DN_RT_PKT_L1RT:
712 		case DN_RT_PKT_L2RT:
713 			return NF_HOOK(NFPROTO_DECNET, NF_DN_ROUTE,
714 				       skb, skb->dev, NULL,
715 				       dn_route_discard);
716 		case DN_RT_PKT_ERTH:
717 			return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
718 				       skb, skb->dev, NULL,
719 				       dn_neigh_router_hello);
720 
721 		case DN_RT_PKT_EEDH:
722 			return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
723 				       skb, skb->dev, NULL,
724 				       dn_neigh_endnode_hello);
725 		}
726 	} else {
727 		if (dn->parms.state != DN_DEV_S_RU)
728 			goto dump_it;
729 
730 		skb_pull(skb, 1); /* Pull flags */
731 
732 		switch (flags & DN_RT_PKT_MSK) {
733 		case DN_RT_PKT_LONG:
734 			return dn_route_rx_long(skb);
735 		case DN_RT_PKT_SHORT:
736 			return dn_route_rx_short(skb);
737 		}
738 	}
739 
740 dump_it:
741 	kfree_skb(skb);
742 out:
743 	return NET_RX_DROP;
744 }
745 
dn_to_neigh_output(struct sk_buff * skb)746 static int dn_to_neigh_output(struct sk_buff *skb)
747 {
748 	struct dst_entry *dst = skb_dst(skb);
749 	struct dn_route *rt = (struct dn_route *) dst;
750 	struct neighbour *n = rt->n;
751 
752 	return n->output(n, skb);
753 }
754 
dn_output(struct sk_buff * skb)755 static int dn_output(struct sk_buff *skb)
756 {
757 	struct dst_entry *dst = skb_dst(skb);
758 	struct dn_route *rt = (struct dn_route *)dst;
759 	struct net_device *dev = dst->dev;
760 	struct dn_skb_cb *cb = DN_SKB_CB(skb);
761 
762 	int err = -EINVAL;
763 
764 	if (rt->n == NULL)
765 		goto error;
766 
767 	skb->dev = dev;
768 
769 	cb->src = rt->rt_saddr;
770 	cb->dst = rt->rt_daddr;
771 
772 	/*
773 	 * Always set the Intra-Ethernet bit on all outgoing packets
774 	 * originated on this node. Only valid flag from upper layers
775 	 * is return-to-sender-requested. Set hop count to 0 too.
776 	 */
777 	cb->rt_flags &= ~DN_RT_F_RQR;
778 	cb->rt_flags |= DN_RT_F_IE;
779 	cb->hops = 0;
780 
781 	return NF_HOOK(NFPROTO_DECNET, NF_DN_LOCAL_OUT, skb, NULL, dev,
782 		       dn_to_neigh_output);
783 
784 error:
785 	net_dbg_ratelimited("dn_output: This should not happen\n");
786 
787 	kfree_skb(skb);
788 
789 	return err;
790 }
791 
dn_forward(struct sk_buff * skb)792 static int dn_forward(struct sk_buff *skb)
793 {
794 	struct dn_skb_cb *cb = DN_SKB_CB(skb);
795 	struct dst_entry *dst = skb_dst(skb);
796 	struct dn_dev *dn_db = rcu_dereference(dst->dev->dn_ptr);
797 	struct dn_route *rt;
798 	int header_len;
799 #ifdef CONFIG_NETFILTER
800 	struct net_device *dev = skb->dev;
801 #endif
802 
803 	if (skb->pkt_type != PACKET_HOST)
804 		goto drop;
805 
806 	/* Ensure that we have enough space for headers */
807 	rt = (struct dn_route *)skb_dst(skb);
808 	header_len = dn_db->use_long ? 21 : 6;
809 	if (skb_cow(skb, LL_RESERVED_SPACE(rt->dst.dev)+header_len))
810 		goto drop;
811 
812 	/*
813 	 * Hop count exceeded.
814 	 */
815 	if (++cb->hops > 30)
816 		goto drop;
817 
818 	skb->dev = rt->dst.dev;
819 
820 	/*
821 	 * If packet goes out same interface it came in on, then set
822 	 * the Intra-Ethernet bit. This has no effect for short
823 	 * packets, so we don't need to test for them here.
824 	 */
825 	cb->rt_flags &= ~DN_RT_F_IE;
826 	if (rt->rt_flags & RTCF_DOREDIRECT)
827 		cb->rt_flags |= DN_RT_F_IE;
828 
829 	return NF_HOOK(NFPROTO_DECNET, NF_DN_FORWARD, skb, dev, skb->dev,
830 		       dn_to_neigh_output);
831 
832 drop:
833 	kfree_skb(skb);
834 	return NET_RX_DROP;
835 }
836 
837 /*
838  * Used to catch bugs. This should never normally get
839  * called.
840  */
dn_rt_bug(struct sk_buff * skb)841 static int dn_rt_bug(struct sk_buff *skb)
842 {
843 	struct dn_skb_cb *cb = DN_SKB_CB(skb);
844 
845 	net_dbg_ratelimited("dn_rt_bug: skb from:%04x to:%04x\n",
846 			    le16_to_cpu(cb->src), le16_to_cpu(cb->dst));
847 
848 	kfree_skb(skb);
849 
850 	return NET_RX_DROP;
851 }
852 
dn_dst_default_advmss(const struct dst_entry * dst)853 static unsigned int dn_dst_default_advmss(const struct dst_entry *dst)
854 {
855 	return dn_mss_from_pmtu(dst->dev, dst_mtu(dst));
856 }
857 
dn_dst_mtu(const struct dst_entry * dst)858 static unsigned int dn_dst_mtu(const struct dst_entry *dst)
859 {
860 	unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
861 
862 	return mtu ? : dst->dev->mtu;
863 }
864 
dn_dst_neigh_lookup(const struct dst_entry * dst,struct sk_buff * skb,const void * daddr)865 static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst,
866 					     struct sk_buff *skb,
867 					     const void *daddr)
868 {
869 	return __neigh_lookup_errno(&dn_neigh_table, daddr, dst->dev);
870 }
871 
dn_rt_set_next_hop(struct dn_route * rt,struct dn_fib_res * res)872 static int dn_rt_set_next_hop(struct dn_route *rt, struct dn_fib_res *res)
873 {
874 	struct dn_fib_info *fi = res->fi;
875 	struct net_device *dev = rt->dst.dev;
876 	unsigned int mss_metric;
877 	struct neighbour *n;
878 
879 	if (fi) {
880 		if (DN_FIB_RES_GW(*res) &&
881 		    DN_FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
882 			rt->rt_gateway = DN_FIB_RES_GW(*res);
883 		dst_init_metrics(&rt->dst, fi->fib_metrics, true);
884 	}
885 	rt->rt_type = res->type;
886 
887 	if (dev != NULL && rt->n == NULL) {
888 		n = __neigh_lookup_errno(&dn_neigh_table, &rt->rt_gateway, dev);
889 		if (IS_ERR(n))
890 			return PTR_ERR(n);
891 		rt->n = n;
892 	}
893 
894 	if (dst_metric(&rt->dst, RTAX_MTU) > rt->dst.dev->mtu)
895 		dst_metric_set(&rt->dst, RTAX_MTU, rt->dst.dev->mtu);
896 	mss_metric = dst_metric_raw(&rt->dst, RTAX_ADVMSS);
897 	if (mss_metric) {
898 		unsigned int mss = dn_mss_from_pmtu(dev, dst_mtu(&rt->dst));
899 		if (mss_metric > mss)
900 			dst_metric_set(&rt->dst, RTAX_ADVMSS, mss);
901 	}
902 	return 0;
903 }
904 
dn_match_addr(__le16 addr1,__le16 addr2)905 static inline int dn_match_addr(__le16 addr1, __le16 addr2)
906 {
907 	__u16 tmp = le16_to_cpu(addr1) ^ le16_to_cpu(addr2);
908 	int match = 16;
909 	while(tmp) {
910 		tmp >>= 1;
911 		match--;
912 	}
913 	return match;
914 }
915 
dnet_select_source(const struct net_device * dev,__le16 daddr,int scope)916 static __le16 dnet_select_source(const struct net_device *dev, __le16 daddr, int scope)
917 {
918 	__le16 saddr = 0;
919 	struct dn_dev *dn_db;
920 	struct dn_ifaddr *ifa;
921 	int best_match = 0;
922 	int ret;
923 
924 	rcu_read_lock();
925 	dn_db = rcu_dereference(dev->dn_ptr);
926 	for (ifa = rcu_dereference(dn_db->ifa_list);
927 	     ifa != NULL;
928 	     ifa = rcu_dereference(ifa->ifa_next)) {
929 		if (ifa->ifa_scope > scope)
930 			continue;
931 		if (!daddr) {
932 			saddr = ifa->ifa_local;
933 			break;
934 		}
935 		ret = dn_match_addr(daddr, ifa->ifa_local);
936 		if (ret > best_match)
937 			saddr = ifa->ifa_local;
938 		if (best_match == 0)
939 			saddr = ifa->ifa_local;
940 	}
941 	rcu_read_unlock();
942 
943 	return saddr;
944 }
945 
__dn_fib_res_prefsrc(struct dn_fib_res * res)946 static inline __le16 __dn_fib_res_prefsrc(struct dn_fib_res *res)
947 {
948 	return dnet_select_source(DN_FIB_RES_DEV(*res), DN_FIB_RES_GW(*res), res->scope);
949 }
950 
dn_fib_rules_map_destination(__le16 daddr,struct dn_fib_res * res)951 static inline __le16 dn_fib_rules_map_destination(__le16 daddr, struct dn_fib_res *res)
952 {
953 	__le16 mask = dnet_make_mask(res->prefixlen);
954 	return (daddr&~mask)|res->fi->fib_nh->nh_gw;
955 }
956 
dn_route_output_slow(struct dst_entry ** pprt,const struct flowidn * oldflp,int try_hard)957 static int dn_route_output_slow(struct dst_entry **pprt, const struct flowidn *oldflp, int try_hard)
958 {
959 	struct flowidn fld = {
960 		.daddr = oldflp->daddr,
961 		.saddr = oldflp->saddr,
962 		.flowidn_scope = RT_SCOPE_UNIVERSE,
963 		.flowidn_mark = oldflp->flowidn_mark,
964 		.flowidn_iif = LOOPBACK_IFINDEX,
965 		.flowidn_oif = oldflp->flowidn_oif,
966 	};
967 	struct dn_route *rt = NULL;
968 	struct net_device *dev_out = NULL, *dev;
969 	struct neighbour *neigh = NULL;
970 	unsigned int hash;
971 	unsigned int flags = 0;
972 	struct dn_fib_res res = { .fi = NULL, .type = RTN_UNICAST };
973 	int err;
974 	int free_res = 0;
975 	__le16 gateway = 0;
976 
977 	if (decnet_debug_level & 16)
978 		printk(KERN_DEBUG
979 		       "dn_route_output_slow: dst=%04x src=%04x mark=%d"
980 		       " iif=%d oif=%d\n", le16_to_cpu(oldflp->daddr),
981 		       le16_to_cpu(oldflp->saddr),
982 		       oldflp->flowidn_mark, LOOPBACK_IFINDEX,
983 		       oldflp->flowidn_oif);
984 
985 	/* If we have an output interface, verify its a DECnet device */
986 	if (oldflp->flowidn_oif) {
987 		dev_out = dev_get_by_index(&init_net, oldflp->flowidn_oif);
988 		err = -ENODEV;
989 		if (dev_out && dev_out->dn_ptr == NULL) {
990 			dev_put(dev_out);
991 			dev_out = NULL;
992 		}
993 		if (dev_out == NULL)
994 			goto out;
995 	}
996 
997 	/* If we have a source address, verify that its a local address */
998 	if (oldflp->saddr) {
999 		err = -EADDRNOTAVAIL;
1000 
1001 		if (dev_out) {
1002 			if (dn_dev_islocal(dev_out, oldflp->saddr))
1003 				goto source_ok;
1004 			dev_put(dev_out);
1005 			goto out;
1006 		}
1007 		rcu_read_lock();
1008 		for_each_netdev_rcu(&init_net, dev) {
1009 			if (!dev->dn_ptr)
1010 				continue;
1011 			if (!dn_dev_islocal(dev, oldflp->saddr))
1012 				continue;
1013 			if ((dev->flags & IFF_LOOPBACK) &&
1014 			    oldflp->daddr &&
1015 			    !dn_dev_islocal(dev, oldflp->daddr))
1016 				continue;
1017 
1018 			dev_out = dev;
1019 			break;
1020 		}
1021 		rcu_read_unlock();
1022 		if (dev_out == NULL)
1023 			goto out;
1024 		dev_hold(dev_out);
1025 source_ok:
1026 		;
1027 	}
1028 
1029 	/* No destination? Assume its local */
1030 	if (!fld.daddr) {
1031 		fld.daddr = fld.saddr;
1032 
1033 		err = -EADDRNOTAVAIL;
1034 		if (dev_out)
1035 			dev_put(dev_out);
1036 		dev_out = init_net.loopback_dev;
1037 		dev_hold(dev_out);
1038 		if (!fld.daddr) {
1039 			fld.daddr =
1040 			fld.saddr = dnet_select_source(dev_out, 0,
1041 						       RT_SCOPE_HOST);
1042 			if (!fld.daddr)
1043 				goto out;
1044 		}
1045 		fld.flowidn_oif = LOOPBACK_IFINDEX;
1046 		res.type = RTN_LOCAL;
1047 		goto make_route;
1048 	}
1049 
1050 	if (decnet_debug_level & 16)
1051 		printk(KERN_DEBUG
1052 		       "dn_route_output_slow: initial checks complete."
1053 		       " dst=%o4x src=%04x oif=%d try_hard=%d\n",
1054 		       le16_to_cpu(fld.daddr), le16_to_cpu(fld.saddr),
1055 		       fld.flowidn_oif, try_hard);
1056 
1057 	/*
1058 	 * N.B. If the kernel is compiled without router support then
1059 	 * dn_fib_lookup() will evaluate to non-zero so this if () block
1060 	 * will always be executed.
1061 	 */
1062 	err = -ESRCH;
1063 	if (try_hard || (err = dn_fib_lookup(&fld, &res)) != 0) {
1064 		struct dn_dev *dn_db;
1065 		if (err != -ESRCH)
1066 			goto out;
1067 		/*
1068 		 * Here the fallback is basically the standard algorithm for
1069 		 * routing in endnodes which is described in the DECnet routing
1070 		 * docs
1071 		 *
1072 		 * If we are not trying hard, look in neighbour cache.
1073 		 * The result is tested to ensure that if a specific output
1074 		 * device/source address was requested, then we honour that
1075 		 * here
1076 		 */
1077 		if (!try_hard) {
1078 			neigh = neigh_lookup_nodev(&dn_neigh_table, &init_net, &fld.daddr);
1079 			if (neigh) {
1080 				if ((oldflp->flowidn_oif &&
1081 				    (neigh->dev->ifindex != oldflp->flowidn_oif)) ||
1082 				    (oldflp->saddr &&
1083 				    (!dn_dev_islocal(neigh->dev,
1084 						     oldflp->saddr)))) {
1085 					neigh_release(neigh);
1086 					neigh = NULL;
1087 				} else {
1088 					if (dev_out)
1089 						dev_put(dev_out);
1090 					if (dn_dev_islocal(neigh->dev, fld.daddr)) {
1091 						dev_out = init_net.loopback_dev;
1092 						res.type = RTN_LOCAL;
1093 					} else {
1094 						dev_out = neigh->dev;
1095 					}
1096 					dev_hold(dev_out);
1097 					goto select_source;
1098 				}
1099 			}
1100 		}
1101 
1102 		/* Not there? Perhaps its a local address */
1103 		if (dev_out == NULL)
1104 			dev_out = dn_dev_get_default();
1105 		err = -ENODEV;
1106 		if (dev_out == NULL)
1107 			goto out;
1108 		dn_db = rcu_dereference_raw(dev_out->dn_ptr);
1109 		/* Possible improvement - check all devices for local addr */
1110 		if (dn_dev_islocal(dev_out, fld.daddr)) {
1111 			dev_put(dev_out);
1112 			dev_out = init_net.loopback_dev;
1113 			dev_hold(dev_out);
1114 			res.type = RTN_LOCAL;
1115 			goto select_source;
1116 		}
1117 		/* Not local either.... try sending it to the default router */
1118 		neigh = neigh_clone(dn_db->router);
1119 		BUG_ON(neigh && neigh->dev != dev_out);
1120 
1121 		/* Ok then, we assume its directly connected and move on */
1122 select_source:
1123 		if (neigh)
1124 			gateway = ((struct dn_neigh *)neigh)->addr;
1125 		if (gateway == 0)
1126 			gateway = fld.daddr;
1127 		if (fld.saddr == 0) {
1128 			fld.saddr = dnet_select_source(dev_out, gateway,
1129 						       res.type == RTN_LOCAL ?
1130 						       RT_SCOPE_HOST :
1131 						       RT_SCOPE_LINK);
1132 			if (fld.saddr == 0 && res.type != RTN_LOCAL)
1133 				goto e_addr;
1134 		}
1135 		fld.flowidn_oif = dev_out->ifindex;
1136 		goto make_route;
1137 	}
1138 	free_res = 1;
1139 
1140 	if (res.type == RTN_NAT)
1141 		goto e_inval;
1142 
1143 	if (res.type == RTN_LOCAL) {
1144 		if (!fld.saddr)
1145 			fld.saddr = fld.daddr;
1146 		if (dev_out)
1147 			dev_put(dev_out);
1148 		dev_out = init_net.loopback_dev;
1149 		dev_hold(dev_out);
1150 		fld.flowidn_oif = dev_out->ifindex;
1151 		if (res.fi)
1152 			dn_fib_info_put(res.fi);
1153 		res.fi = NULL;
1154 		goto make_route;
1155 	}
1156 
1157 	if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1158 		dn_fib_select_multipath(&fld, &res);
1159 
1160 	/*
1161 	 * We could add some logic to deal with default routes here and
1162 	 * get rid of some of the special casing above.
1163 	 */
1164 
1165 	if (!fld.saddr)
1166 		fld.saddr = DN_FIB_RES_PREFSRC(res);
1167 
1168 	if (dev_out)
1169 		dev_put(dev_out);
1170 	dev_out = DN_FIB_RES_DEV(res);
1171 	dev_hold(dev_out);
1172 	fld.flowidn_oif = dev_out->ifindex;
1173 	gateway = DN_FIB_RES_GW(res);
1174 
1175 make_route:
1176 	if (dev_out->flags & IFF_LOOPBACK)
1177 		flags |= RTCF_LOCAL;
1178 
1179 	rt = dst_alloc(&dn_dst_ops, dev_out, 1, DST_OBSOLETE_NONE, DST_HOST);
1180 	if (rt == NULL)
1181 		goto e_nobufs;
1182 
1183 	memset(&rt->fld, 0, sizeof(rt->fld));
1184 	rt->fld.saddr        = oldflp->saddr;
1185 	rt->fld.daddr        = oldflp->daddr;
1186 	rt->fld.flowidn_oif  = oldflp->flowidn_oif;
1187 	rt->fld.flowidn_iif  = 0;
1188 	rt->fld.flowidn_mark = oldflp->flowidn_mark;
1189 
1190 	rt->rt_saddr      = fld.saddr;
1191 	rt->rt_daddr      = fld.daddr;
1192 	rt->rt_gateway    = gateway ? gateway : fld.daddr;
1193 	rt->rt_local_src  = fld.saddr;
1194 
1195 	rt->rt_dst_map    = fld.daddr;
1196 	rt->rt_src_map    = fld.saddr;
1197 
1198 	rt->n = neigh;
1199 	neigh = NULL;
1200 
1201 	rt->dst.lastuse = jiffies;
1202 	rt->dst.output  = dn_output;
1203 	rt->dst.input   = dn_rt_bug;
1204 	rt->rt_flags      = flags;
1205 	if (flags & RTCF_LOCAL)
1206 		rt->dst.input = dn_nsp_rx;
1207 
1208 	err = dn_rt_set_next_hop(rt, &res);
1209 	if (err)
1210 		goto e_neighbour;
1211 
1212 	hash = dn_hash(rt->fld.saddr, rt->fld.daddr);
1213 	dn_insert_route(rt, hash, (struct dn_route **)pprt);
1214 
1215 done:
1216 	if (neigh)
1217 		neigh_release(neigh);
1218 	if (free_res)
1219 		dn_fib_res_put(&res);
1220 	if (dev_out)
1221 		dev_put(dev_out);
1222 out:
1223 	return err;
1224 
1225 e_addr:
1226 	err = -EADDRNOTAVAIL;
1227 	goto done;
1228 e_inval:
1229 	err = -EINVAL;
1230 	goto done;
1231 e_nobufs:
1232 	err = -ENOBUFS;
1233 	goto done;
1234 e_neighbour:
1235 	dst_free(&rt->dst);
1236 	goto e_nobufs;
1237 }
1238 
1239 
1240 /*
1241  * N.B. The flags may be moved into the flowi at some future stage.
1242  */
__dn_route_output_key(struct dst_entry ** pprt,const struct flowidn * flp,int flags)1243 static int __dn_route_output_key(struct dst_entry **pprt, const struct flowidn *flp, int flags)
1244 {
1245 	unsigned int hash = dn_hash(flp->saddr, flp->daddr);
1246 	struct dn_route *rt = NULL;
1247 
1248 	if (!(flags & MSG_TRYHARD)) {
1249 		rcu_read_lock_bh();
1250 		for (rt = rcu_dereference_bh(dn_rt_hash_table[hash].chain); rt;
1251 			rt = rcu_dereference_bh(rt->dst.dn_next)) {
1252 			if ((flp->daddr == rt->fld.daddr) &&
1253 			    (flp->saddr == rt->fld.saddr) &&
1254 			    (flp->flowidn_mark == rt->fld.flowidn_mark) &&
1255 			    dn_is_output_route(rt) &&
1256 			    (rt->fld.flowidn_oif == flp->flowidn_oif)) {
1257 				dst_use(&rt->dst, jiffies);
1258 				rcu_read_unlock_bh();
1259 				*pprt = &rt->dst;
1260 				return 0;
1261 			}
1262 		}
1263 		rcu_read_unlock_bh();
1264 	}
1265 
1266 	return dn_route_output_slow(pprt, flp, flags);
1267 }
1268 
dn_route_output_key(struct dst_entry ** pprt,struct flowidn * flp,int flags)1269 static int dn_route_output_key(struct dst_entry **pprt, struct flowidn *flp, int flags)
1270 {
1271 	int err;
1272 
1273 	err = __dn_route_output_key(pprt, flp, flags);
1274 	if (err == 0 && flp->flowidn_proto) {
1275 		*pprt = xfrm_lookup(&init_net, *pprt,
1276 				    flowidn_to_flowi(flp), NULL, 0);
1277 		if (IS_ERR(*pprt)) {
1278 			err = PTR_ERR(*pprt);
1279 			*pprt = NULL;
1280 		}
1281 	}
1282 	return err;
1283 }
1284 
dn_route_output_sock(struct dst_entry __rcu ** pprt,struct flowidn * fl,struct sock * sk,int flags)1285 int dn_route_output_sock(struct dst_entry __rcu **pprt, struct flowidn *fl, struct sock *sk, int flags)
1286 {
1287 	int err;
1288 
1289 	err = __dn_route_output_key(pprt, fl, flags & MSG_TRYHARD);
1290 	if (err == 0 && fl->flowidn_proto) {
1291 		if (!(flags & MSG_DONTWAIT))
1292 			fl->flowidn_flags |= FLOWI_FLAG_CAN_SLEEP;
1293 		*pprt = xfrm_lookup(&init_net, *pprt,
1294 				    flowidn_to_flowi(fl), sk, 0);
1295 		if (IS_ERR(*pprt)) {
1296 			err = PTR_ERR(*pprt);
1297 			*pprt = NULL;
1298 		}
1299 	}
1300 	return err;
1301 }
1302 
dn_route_input_slow(struct sk_buff * skb)1303 static int dn_route_input_slow(struct sk_buff *skb)
1304 {
1305 	struct dn_route *rt = NULL;
1306 	struct dn_skb_cb *cb = DN_SKB_CB(skb);
1307 	struct net_device *in_dev = skb->dev;
1308 	struct net_device *out_dev = NULL;
1309 	struct dn_dev *dn_db;
1310 	struct neighbour *neigh = NULL;
1311 	unsigned int hash;
1312 	int flags = 0;
1313 	__le16 gateway = 0;
1314 	__le16 local_src = 0;
1315 	struct flowidn fld = {
1316 		.daddr = cb->dst,
1317 		.saddr = cb->src,
1318 		.flowidn_scope = RT_SCOPE_UNIVERSE,
1319 		.flowidn_mark = skb->mark,
1320 		.flowidn_iif = skb->dev->ifindex,
1321 	};
1322 	struct dn_fib_res res = { .fi = NULL, .type = RTN_UNREACHABLE };
1323 	int err = -EINVAL;
1324 	int free_res = 0;
1325 
1326 	dev_hold(in_dev);
1327 
1328 	if ((dn_db = rcu_dereference(in_dev->dn_ptr)) == NULL)
1329 		goto out;
1330 
1331 	/* Zero source addresses are not allowed */
1332 	if (fld.saddr == 0)
1333 		goto out;
1334 
1335 	/*
1336 	 * In this case we've just received a packet from a source
1337 	 * outside ourselves pretending to come from us. We don't
1338 	 * allow it any further to prevent routing loops, spoofing and
1339 	 * other nasties. Loopback packets already have the dst attached
1340 	 * so this only affects packets which have originated elsewhere.
1341 	 */
1342 	err  = -ENOTUNIQ;
1343 	if (dn_dev_islocal(in_dev, cb->src))
1344 		goto out;
1345 
1346 	err = dn_fib_lookup(&fld, &res);
1347 	if (err) {
1348 		if (err != -ESRCH)
1349 			goto out;
1350 		/*
1351 		 * Is the destination us ?
1352 		 */
1353 		if (!dn_dev_islocal(in_dev, cb->dst))
1354 			goto e_inval;
1355 
1356 		res.type = RTN_LOCAL;
1357 	} else {
1358 		__le16 src_map = fld.saddr;
1359 		free_res = 1;
1360 
1361 		out_dev = DN_FIB_RES_DEV(res);
1362 		if (out_dev == NULL) {
1363 			net_crit_ratelimited("Bug in dn_route_input_slow() No output device\n");
1364 			goto e_inval;
1365 		}
1366 		dev_hold(out_dev);
1367 
1368 		if (res.r)
1369 			src_map = fld.saddr; /* no NAT support for now */
1370 
1371 		gateway = DN_FIB_RES_GW(res);
1372 		if (res.type == RTN_NAT) {
1373 			fld.daddr = dn_fib_rules_map_destination(fld.daddr, &res);
1374 			dn_fib_res_put(&res);
1375 			free_res = 0;
1376 			if (dn_fib_lookup(&fld, &res))
1377 				goto e_inval;
1378 			free_res = 1;
1379 			if (res.type != RTN_UNICAST)
1380 				goto e_inval;
1381 			flags |= RTCF_DNAT;
1382 			gateway = fld.daddr;
1383 		}
1384 		fld.saddr = src_map;
1385 	}
1386 
1387 	switch(res.type) {
1388 	case RTN_UNICAST:
1389 		/*
1390 		 * Forwarding check here, we only check for forwarding
1391 		 * being turned off, if you want to only forward intra
1392 		 * area, its up to you to set the routing tables up
1393 		 * correctly.
1394 		 */
1395 		if (dn_db->parms.forwarding == 0)
1396 			goto e_inval;
1397 
1398 		if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1399 			dn_fib_select_multipath(&fld, &res);
1400 
1401 		/*
1402 		 * Check for out_dev == in_dev. We use the RTCF_DOREDIRECT
1403 		 * flag as a hint to set the intra-ethernet bit when
1404 		 * forwarding. If we've got NAT in operation, we don't do
1405 		 * this optimisation.
1406 		 */
1407 		if (out_dev == in_dev && !(flags & RTCF_NAT))
1408 			flags |= RTCF_DOREDIRECT;
1409 
1410 		local_src = DN_FIB_RES_PREFSRC(res);
1411 
1412 	case RTN_BLACKHOLE:
1413 	case RTN_UNREACHABLE:
1414 		break;
1415 	case RTN_LOCAL:
1416 		flags |= RTCF_LOCAL;
1417 		fld.saddr = cb->dst;
1418 		fld.daddr = cb->src;
1419 
1420 		/* Routing tables gave us a gateway */
1421 		if (gateway)
1422 			goto make_route;
1423 
1424 		/* Packet was intra-ethernet, so we know its on-link */
1425 		if (cb->rt_flags & DN_RT_F_IE) {
1426 			gateway = cb->src;
1427 			goto make_route;
1428 		}
1429 
1430 		/* Use the default router if there is one */
1431 		neigh = neigh_clone(dn_db->router);
1432 		if (neigh) {
1433 			gateway = ((struct dn_neigh *)neigh)->addr;
1434 			goto make_route;
1435 		}
1436 
1437 		/* Close eyes and pray */
1438 		gateway = cb->src;
1439 		goto make_route;
1440 	default:
1441 		goto e_inval;
1442 	}
1443 
1444 make_route:
1445 	rt = dst_alloc(&dn_dst_ops, out_dev, 0, DST_OBSOLETE_NONE, DST_HOST);
1446 	if (rt == NULL)
1447 		goto e_nobufs;
1448 
1449 	memset(&rt->fld, 0, sizeof(rt->fld));
1450 	rt->rt_saddr      = fld.saddr;
1451 	rt->rt_daddr      = fld.daddr;
1452 	rt->rt_gateway    = fld.daddr;
1453 	if (gateway)
1454 		rt->rt_gateway = gateway;
1455 	rt->rt_local_src  = local_src ? local_src : rt->rt_saddr;
1456 
1457 	rt->rt_dst_map    = fld.daddr;
1458 	rt->rt_src_map    = fld.saddr;
1459 
1460 	rt->fld.saddr        = cb->src;
1461 	rt->fld.daddr        = cb->dst;
1462 	rt->fld.flowidn_oif  = 0;
1463 	rt->fld.flowidn_iif  = in_dev->ifindex;
1464 	rt->fld.flowidn_mark = fld.flowidn_mark;
1465 
1466 	rt->n = neigh;
1467 	rt->dst.lastuse = jiffies;
1468 	rt->dst.output = dn_rt_bug;
1469 	switch (res.type) {
1470 	case RTN_UNICAST:
1471 		rt->dst.input = dn_forward;
1472 		break;
1473 	case RTN_LOCAL:
1474 		rt->dst.output = dn_output;
1475 		rt->dst.input = dn_nsp_rx;
1476 		rt->dst.dev = in_dev;
1477 		flags |= RTCF_LOCAL;
1478 		break;
1479 	default:
1480 	case RTN_UNREACHABLE:
1481 	case RTN_BLACKHOLE:
1482 		rt->dst.input = dst_discard;
1483 	}
1484 	rt->rt_flags = flags;
1485 
1486 	err = dn_rt_set_next_hop(rt, &res);
1487 	if (err)
1488 		goto e_neighbour;
1489 
1490 	hash = dn_hash(rt->fld.saddr, rt->fld.daddr);
1491 	dn_insert_route(rt, hash, &rt);
1492 	skb_dst_set(skb, &rt->dst);
1493 
1494 done:
1495 	if (neigh)
1496 		neigh_release(neigh);
1497 	if (free_res)
1498 		dn_fib_res_put(&res);
1499 	dev_put(in_dev);
1500 	if (out_dev)
1501 		dev_put(out_dev);
1502 out:
1503 	return err;
1504 
1505 e_inval:
1506 	err = -EINVAL;
1507 	goto done;
1508 
1509 e_nobufs:
1510 	err = -ENOBUFS;
1511 	goto done;
1512 
1513 e_neighbour:
1514 	dst_free(&rt->dst);
1515 	goto done;
1516 }
1517 
dn_route_input(struct sk_buff * skb)1518 static int dn_route_input(struct sk_buff *skb)
1519 {
1520 	struct dn_route *rt;
1521 	struct dn_skb_cb *cb = DN_SKB_CB(skb);
1522 	unsigned int hash = dn_hash(cb->src, cb->dst);
1523 
1524 	if (skb_dst(skb))
1525 		return 0;
1526 
1527 	rcu_read_lock();
1528 	for(rt = rcu_dereference(dn_rt_hash_table[hash].chain); rt != NULL;
1529 	    rt = rcu_dereference(rt->dst.dn_next)) {
1530 		if ((rt->fld.saddr == cb->src) &&
1531 		    (rt->fld.daddr == cb->dst) &&
1532 		    (rt->fld.flowidn_oif == 0) &&
1533 		    (rt->fld.flowidn_mark == skb->mark) &&
1534 		    (rt->fld.flowidn_iif == cb->iif)) {
1535 			dst_use(&rt->dst, jiffies);
1536 			rcu_read_unlock();
1537 			skb_dst_set(skb, (struct dst_entry *)rt);
1538 			return 0;
1539 		}
1540 	}
1541 	rcu_read_unlock();
1542 
1543 	return dn_route_input_slow(skb);
1544 }
1545 
dn_rt_fill_info(struct sk_buff * skb,u32 portid,u32 seq,int event,int nowait,unsigned int flags)1546 static int dn_rt_fill_info(struct sk_buff *skb, u32 portid, u32 seq,
1547 			   int event, int nowait, unsigned int flags)
1548 {
1549 	struct dn_route *rt = (struct dn_route *)skb_dst(skb);
1550 	struct rtmsg *r;
1551 	struct nlmsghdr *nlh;
1552 	long expires;
1553 
1554 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
1555 	if (!nlh)
1556 		return -EMSGSIZE;
1557 
1558 	r = nlmsg_data(nlh);
1559 	r->rtm_family = AF_DECnet;
1560 	r->rtm_dst_len = 16;
1561 	r->rtm_src_len = 0;
1562 	r->rtm_tos = 0;
1563 	r->rtm_table = RT_TABLE_MAIN;
1564 	r->rtm_type = rt->rt_type;
1565 	r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
1566 	r->rtm_scope = RT_SCOPE_UNIVERSE;
1567 	r->rtm_protocol = RTPROT_UNSPEC;
1568 
1569 	if (rt->rt_flags & RTCF_NOTIFY)
1570 		r->rtm_flags |= RTM_F_NOTIFY;
1571 
1572 	if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN) < 0 ||
1573 	    nla_put_le16(skb, RTA_DST, rt->rt_daddr) < 0)
1574 		goto errout;
1575 
1576 	if (rt->fld.saddr) {
1577 		r->rtm_src_len = 16;
1578 		if (nla_put_le16(skb, RTA_SRC, rt->fld.saddr) < 0)
1579 			goto errout;
1580 	}
1581 	if (rt->dst.dev &&
1582 	    nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex) < 0)
1583 		goto errout;
1584 
1585 	/*
1586 	 * Note to self - change this if input routes reverse direction when
1587 	 * they deal only with inputs and not with replies like they do
1588 	 * currently.
1589 	 */
1590 	if (nla_put_le16(skb, RTA_PREFSRC, rt->rt_local_src) < 0)
1591 		goto errout;
1592 
1593 	if (rt->rt_daddr != rt->rt_gateway &&
1594 	    nla_put_le16(skb, RTA_GATEWAY, rt->rt_gateway) < 0)
1595 		goto errout;
1596 
1597 	if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
1598 		goto errout;
1599 
1600 	expires = rt->dst.expires ? rt->dst.expires - jiffies : 0;
1601 	if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires,
1602 			       rt->dst.error) < 0)
1603 		goto errout;
1604 
1605 	if (dn_is_input_route(rt) &&
1606 	    nla_put_u32(skb, RTA_IIF, rt->fld.flowidn_iif) < 0)
1607 		goto errout;
1608 
1609 	return nlmsg_end(skb, nlh);
1610 
1611 errout:
1612 	nlmsg_cancel(skb, nlh);
1613 	return -EMSGSIZE;
1614 }
1615 
1616 const struct nla_policy rtm_dn_policy[RTA_MAX + 1] = {
1617 	[RTA_DST]		= { .type = NLA_U16 },
1618 	[RTA_SRC]		= { .type = NLA_U16 },
1619 	[RTA_IIF]		= { .type = NLA_U32 },
1620 	[RTA_OIF]		= { .type = NLA_U32 },
1621 	[RTA_GATEWAY]		= { .type = NLA_U16 },
1622 	[RTA_PRIORITY]		= { .type = NLA_U32 },
1623 	[RTA_PREFSRC]		= { .type = NLA_U16 },
1624 	[RTA_METRICS]		= { .type = NLA_NESTED },
1625 	[RTA_MULTIPATH]		= { .type = NLA_NESTED },
1626 	[RTA_TABLE]		= { .type = NLA_U32 },
1627 	[RTA_MARK]		= { .type = NLA_U32 },
1628 };
1629 
1630 /*
1631  * This is called by both endnodes and routers now.
1632  */
dn_cache_getroute(struct sk_buff * in_skb,struct nlmsghdr * nlh)1633 static int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
1634 {
1635 	struct net *net = sock_net(in_skb->sk);
1636 	struct rtmsg *rtm = nlmsg_data(nlh);
1637 	struct dn_route *rt = NULL;
1638 	struct dn_skb_cb *cb;
1639 	int err;
1640 	struct sk_buff *skb;
1641 	struct flowidn fld;
1642 	struct nlattr *tb[RTA_MAX+1];
1643 
1644 	if (!net_eq(net, &init_net))
1645 		return -EINVAL;
1646 
1647 	err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_dn_policy);
1648 	if (err < 0)
1649 		return err;
1650 
1651 	memset(&fld, 0, sizeof(fld));
1652 	fld.flowidn_proto = DNPROTO_NSP;
1653 
1654 	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1655 	if (skb == NULL)
1656 		return -ENOBUFS;
1657 	skb_reset_mac_header(skb);
1658 	cb = DN_SKB_CB(skb);
1659 
1660 	if (tb[RTA_SRC])
1661 		fld.saddr = nla_get_le16(tb[RTA_SRC]);
1662 
1663 	if (tb[RTA_DST])
1664 		fld.daddr = nla_get_le16(tb[RTA_DST]);
1665 
1666 	if (tb[RTA_IIF])
1667 		fld.flowidn_iif = nla_get_u32(tb[RTA_IIF]);
1668 
1669 	if (fld.flowidn_iif) {
1670 		struct net_device *dev;
1671 		if ((dev = dev_get_by_index(&init_net, fld.flowidn_iif)) == NULL) {
1672 			kfree_skb(skb);
1673 			return -ENODEV;
1674 		}
1675 		if (!dev->dn_ptr) {
1676 			dev_put(dev);
1677 			kfree_skb(skb);
1678 			return -ENODEV;
1679 		}
1680 		skb->protocol = htons(ETH_P_DNA_RT);
1681 		skb->dev = dev;
1682 		cb->src = fld.saddr;
1683 		cb->dst = fld.daddr;
1684 		local_bh_disable();
1685 		err = dn_route_input(skb);
1686 		local_bh_enable();
1687 		memset(cb, 0, sizeof(struct dn_skb_cb));
1688 		rt = (struct dn_route *)skb_dst(skb);
1689 		if (!err && -rt->dst.error)
1690 			err = rt->dst.error;
1691 	} else {
1692 		if (tb[RTA_OIF])
1693 			fld.flowidn_oif = nla_get_u32(tb[RTA_OIF]);
1694 
1695 		err = dn_route_output_key((struct dst_entry **)&rt, &fld, 0);
1696 	}
1697 
1698 	if (skb->dev)
1699 		dev_put(skb->dev);
1700 	skb->dev = NULL;
1701 	if (err)
1702 		goto out_free;
1703 	skb_dst_set(skb, &rt->dst);
1704 	if (rtm->rtm_flags & RTM_F_NOTIFY)
1705 		rt->rt_flags |= RTCF_NOTIFY;
1706 
1707 	err = dn_rt_fill_info(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, RTM_NEWROUTE, 0, 0);
1708 
1709 	if (err == 0)
1710 		goto out_free;
1711 	if (err < 0) {
1712 		err = -EMSGSIZE;
1713 		goto out_free;
1714 	}
1715 
1716 	return rtnl_unicast(skb, &init_net, NETLINK_CB(in_skb).portid);
1717 
1718 out_free:
1719 	kfree_skb(skb);
1720 	return err;
1721 }
1722 
1723 /*
1724  * For routers, this is called from dn_fib_dump, but for endnodes its
1725  * called directly from the rtnetlink dispatch table.
1726  */
dn_cache_dump(struct sk_buff * skb,struct netlink_callback * cb)1727 int dn_cache_dump(struct sk_buff *skb, struct netlink_callback *cb)
1728 {
1729 	struct net *net = sock_net(skb->sk);
1730 	struct dn_route *rt;
1731 	int h, s_h;
1732 	int idx, s_idx;
1733 	struct rtmsg *rtm;
1734 
1735 	if (!net_eq(net, &init_net))
1736 		return 0;
1737 
1738 	if (nlmsg_len(cb->nlh) < sizeof(struct rtmsg))
1739 		return -EINVAL;
1740 
1741 	rtm = nlmsg_data(cb->nlh);
1742 	if (!(rtm->rtm_flags & RTM_F_CLONED))
1743 		return 0;
1744 
1745 	s_h = cb->args[0];
1746 	s_idx = idx = cb->args[1];
1747 	for(h = 0; h <= dn_rt_hash_mask; h++) {
1748 		if (h < s_h)
1749 			continue;
1750 		if (h > s_h)
1751 			s_idx = 0;
1752 		rcu_read_lock_bh();
1753 		for(rt = rcu_dereference_bh(dn_rt_hash_table[h].chain), idx = 0;
1754 			rt;
1755 			rt = rcu_dereference_bh(rt->dst.dn_next), idx++) {
1756 			if (idx < s_idx)
1757 				continue;
1758 			skb_dst_set(skb, dst_clone(&rt->dst));
1759 			if (dn_rt_fill_info(skb, NETLINK_CB(cb->skb).portid,
1760 					cb->nlh->nlmsg_seq, RTM_NEWROUTE,
1761 					1, NLM_F_MULTI) <= 0) {
1762 				skb_dst_drop(skb);
1763 				rcu_read_unlock_bh();
1764 				goto done;
1765 			}
1766 			skb_dst_drop(skb);
1767 		}
1768 		rcu_read_unlock_bh();
1769 	}
1770 
1771 done:
1772 	cb->args[0] = h;
1773 	cb->args[1] = idx;
1774 	return skb->len;
1775 }
1776 
1777 #ifdef CONFIG_PROC_FS
1778 struct dn_rt_cache_iter_state {
1779 	int bucket;
1780 };
1781 
dn_rt_cache_get_first(struct seq_file * seq)1782 static struct dn_route *dn_rt_cache_get_first(struct seq_file *seq)
1783 {
1784 	struct dn_route *rt = NULL;
1785 	struct dn_rt_cache_iter_state *s = seq->private;
1786 
1787 	for(s->bucket = dn_rt_hash_mask; s->bucket >= 0; --s->bucket) {
1788 		rcu_read_lock_bh();
1789 		rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1790 		if (rt)
1791 			break;
1792 		rcu_read_unlock_bh();
1793 	}
1794 	return rt;
1795 }
1796 
dn_rt_cache_get_next(struct seq_file * seq,struct dn_route * rt)1797 static struct dn_route *dn_rt_cache_get_next(struct seq_file *seq, struct dn_route *rt)
1798 {
1799 	struct dn_rt_cache_iter_state *s = seq->private;
1800 
1801 	rt = rcu_dereference_bh(rt->dst.dn_next);
1802 	while (!rt) {
1803 		rcu_read_unlock_bh();
1804 		if (--s->bucket < 0)
1805 			break;
1806 		rcu_read_lock_bh();
1807 		rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1808 	}
1809 	return rt;
1810 }
1811 
dn_rt_cache_seq_start(struct seq_file * seq,loff_t * pos)1812 static void *dn_rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
1813 {
1814 	struct dn_route *rt = dn_rt_cache_get_first(seq);
1815 
1816 	if (rt) {
1817 		while(*pos && (rt = dn_rt_cache_get_next(seq, rt)))
1818 			--*pos;
1819 	}
1820 	return *pos ? NULL : rt;
1821 }
1822 
dn_rt_cache_seq_next(struct seq_file * seq,void * v,loff_t * pos)1823 static void *dn_rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1824 {
1825 	struct dn_route *rt = dn_rt_cache_get_next(seq, v);
1826 	++*pos;
1827 	return rt;
1828 }
1829 
dn_rt_cache_seq_stop(struct seq_file * seq,void * v)1830 static void dn_rt_cache_seq_stop(struct seq_file *seq, void *v)
1831 {
1832 	if (v)
1833 		rcu_read_unlock_bh();
1834 }
1835 
dn_rt_cache_seq_show(struct seq_file * seq,void * v)1836 static int dn_rt_cache_seq_show(struct seq_file *seq, void *v)
1837 {
1838 	struct dn_route *rt = v;
1839 	char buf1[DN_ASCBUF_LEN], buf2[DN_ASCBUF_LEN];
1840 
1841 	seq_printf(seq, "%-8s %-7s %-7s %04d %04d %04d\n",
1842 		   rt->dst.dev ? rt->dst.dev->name : "*",
1843 		   dn_addr2asc(le16_to_cpu(rt->rt_daddr), buf1),
1844 		   dn_addr2asc(le16_to_cpu(rt->rt_saddr), buf2),
1845 		   atomic_read(&rt->dst.__refcnt),
1846 		   rt->dst.__use, 0);
1847 	return 0;
1848 }
1849 
1850 static const struct seq_operations dn_rt_cache_seq_ops = {
1851 	.start	= dn_rt_cache_seq_start,
1852 	.next	= dn_rt_cache_seq_next,
1853 	.stop	= dn_rt_cache_seq_stop,
1854 	.show	= dn_rt_cache_seq_show,
1855 };
1856 
dn_rt_cache_seq_open(struct inode * inode,struct file * file)1857 static int dn_rt_cache_seq_open(struct inode *inode, struct file *file)
1858 {
1859 	return seq_open_private(file, &dn_rt_cache_seq_ops,
1860 			sizeof(struct dn_rt_cache_iter_state));
1861 }
1862 
1863 static const struct file_operations dn_rt_cache_seq_fops = {
1864 	.owner	 = THIS_MODULE,
1865 	.open	 = dn_rt_cache_seq_open,
1866 	.read	 = seq_read,
1867 	.llseek	 = seq_lseek,
1868 	.release = seq_release_private,
1869 };
1870 
1871 #endif /* CONFIG_PROC_FS */
1872 
dn_route_init(void)1873 void __init dn_route_init(void)
1874 {
1875 	int i, goal, order;
1876 
1877 	dn_dst_ops.kmem_cachep =
1878 		kmem_cache_create("dn_dst_cache", sizeof(struct dn_route), 0,
1879 				  SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
1880 	dst_entries_init(&dn_dst_ops);
1881 	setup_timer(&dn_route_timer, dn_dst_check_expire, 0);
1882 	dn_route_timer.expires = jiffies + decnet_dst_gc_interval * HZ;
1883 	add_timer(&dn_route_timer);
1884 
1885 	goal = totalram_pages >> (26 - PAGE_SHIFT);
1886 
1887 	for(order = 0; (1UL << order) < goal; order++)
1888 		/* NOTHING */;
1889 
1890 	/*
1891 	 * Only want 1024 entries max, since the table is very, very unlikely
1892 	 * to be larger than that.
1893 	 */
1894 	while(order && ((((1UL << order) * PAGE_SIZE) /
1895 				sizeof(struct dn_rt_hash_bucket)) >= 2048))
1896 		order--;
1897 
1898 	do {
1899 		dn_rt_hash_mask = (1UL << order) * PAGE_SIZE /
1900 			sizeof(struct dn_rt_hash_bucket);
1901 		while(dn_rt_hash_mask & (dn_rt_hash_mask - 1))
1902 			dn_rt_hash_mask--;
1903 		dn_rt_hash_table = (struct dn_rt_hash_bucket *)
1904 			__get_free_pages(GFP_ATOMIC, order);
1905 	} while (dn_rt_hash_table == NULL && --order > 0);
1906 
1907 	if (!dn_rt_hash_table)
1908 		panic("Failed to allocate DECnet route cache hash table\n");
1909 
1910 	printk(KERN_INFO
1911 		"DECnet: Routing cache hash table of %u buckets, %ldKbytes\n",
1912 		dn_rt_hash_mask,
1913 		(long)(dn_rt_hash_mask*sizeof(struct dn_rt_hash_bucket))/1024);
1914 
1915 	dn_rt_hash_mask--;
1916 	for(i = 0; i <= dn_rt_hash_mask; i++) {
1917 		spin_lock_init(&dn_rt_hash_table[i].lock);
1918 		dn_rt_hash_table[i].chain = NULL;
1919 	}
1920 
1921 	dn_dst_ops.gc_thresh = (dn_rt_hash_mask + 1);
1922 
1923 	proc_create("decnet_cache", S_IRUGO, init_net.proc_net,
1924 		    &dn_rt_cache_seq_fops);
1925 
1926 #ifdef CONFIG_DECNET_ROUTER
1927 	rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute,
1928 		      dn_fib_dump, NULL);
1929 #else
1930 	rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute,
1931 		      dn_cache_dump, NULL);
1932 #endif
1933 }
1934 
dn_route_cleanup(void)1935 void __exit dn_route_cleanup(void)
1936 {
1937 	del_timer(&dn_route_timer);
1938 	dn_run_flush(0);
1939 
1940 	remove_proc_entry("decnet_cache", init_net.proc_net);
1941 	dst_entries_destroy(&dn_dst_ops);
1942 }
1943 
1944