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1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * DECnet       An implementation of the DECnet protocol suite for the LINUX
4  *              operating system.  DECnet is implemented using the  BSD Socket
5  *              interface as the means of communication with the user level.
6  *
7  *              DECnet Routing Functions (Endnode and Router)
8  *
9  * Authors:     Steve Whitehouse <SteveW@ACM.org>
10  *              Eduardo Marcelo Serrat <emserrat@geocities.com>
11  *
12  * Changes:
13  *              Steve Whitehouse : Fixes to allow "intra-ethernet" and
14  *                                 "return-to-sender" bits on outgoing
15  *                                 packets.
16  *		Steve Whitehouse : Timeouts for cached routes.
17  *              Steve Whitehouse : Use dst cache for input routes too.
18  *              Steve Whitehouse : Fixed error values in dn_send_skb.
19  *              Steve Whitehouse : Rework routing functions to better fit
20  *                                 DECnet routing design
21  *              Alexey Kuznetsov : New SMP locking
22  *              Steve Whitehouse : More SMP locking changes & dn_cache_dump()
23  *              Steve Whitehouse : Prerouting NF hook, now really is prerouting.
24  *				   Fixed possible skb leak in rtnetlink funcs.
25  *              Steve Whitehouse : Dave Miller's dynamic hash table sizing and
26  *                                 Alexey Kuznetsov's finer grained locking
27  *                                 from ipv4/route.c.
28  *              Steve Whitehouse : Routing is now starting to look like a
29  *                                 sensible set of code now, mainly due to
30  *                                 my copying the IPv4 routing code. The
31  *                                 hooks here are modified and will continue
32  *                                 to evolve for a while.
33  *              Steve Whitehouse : Real SMP at last :-) Also new netfilter
34  *                                 stuff. Look out raw sockets your days
35  *                                 are numbered!
36  *              Steve Whitehouse : Added return-to-sender functions. Added
37  *                                 backlog congestion level return codes.
38  *		Steve Whitehouse : Fixed bug where routes were set up with
39  *                                 no ref count on net devices.
40  *              Steve Whitehouse : RCU for the route cache
41  *              Steve Whitehouse : Preparations for the flow cache
42  *              Steve Whitehouse : Prepare for nonlinear skbs
43  */
44 
45 /******************************************************************************
46     (c) 1995-1998 E.M. Serrat		emserrat@geocities.com
47 
48 *******************************************************************************/
49 
50 #include <linux/errno.h>
51 #include <linux/types.h>
52 #include <linux/socket.h>
53 #include <linux/in.h>
54 #include <linux/kernel.h>
55 #include <linux/sockios.h>
56 #include <linux/net.h>
57 #include <linux/netdevice.h>
58 #include <linux/inet.h>
59 #include <linux/route.h>
60 #include <linux/in_route.h>
61 #include <linux/slab.h>
62 #include <net/sock.h>
63 #include <linux/mm.h>
64 #include <linux/proc_fs.h>
65 #include <linux/seq_file.h>
66 #include <linux/init.h>
67 #include <linux/rtnetlink.h>
68 #include <linux/string.h>
69 #include <linux/netfilter_decnet.h>
70 #include <linux/rcupdate.h>
71 #include <linux/times.h>
72 #include <linux/export.h>
73 #include <asm/errno.h>
74 #include <net/net_namespace.h>
75 #include <net/netlink.h>
76 #include <net/neighbour.h>
77 #include <net/dst.h>
78 #include <net/flow.h>
79 #include <net/fib_rules.h>
80 #include <net/dn.h>
81 #include <net/dn_dev.h>
82 #include <net/dn_nsp.h>
83 #include <net/dn_route.h>
84 #include <net/dn_neigh.h>
85 #include <net/dn_fib.h>
86 
87 struct dn_rt_hash_bucket
88 {
89 	struct dn_route __rcu *chain;
90 	spinlock_t lock;
91 };
92 
93 extern struct neigh_table dn_neigh_table;
94 
95 
96 static unsigned char dn_hiord_addr[6] = {0xAA,0x00,0x04,0x00,0x00,0x00};
97 
98 static const int dn_rt_min_delay = 2 * HZ;
99 static const int dn_rt_max_delay = 10 * HZ;
100 static const int dn_rt_mtu_expires = 10 * 60 * HZ;
101 
102 static unsigned long dn_rt_deadline;
103 
104 static int dn_dst_gc(struct dst_ops *ops);
105 static struct dst_entry *dn_dst_check(struct dst_entry *, __u32);
106 static unsigned int dn_dst_default_advmss(const struct dst_entry *dst);
107 static unsigned int dn_dst_mtu(const struct dst_entry *dst);
108 static void dn_dst_destroy(struct dst_entry *);
109 static void dn_dst_ifdown(struct dst_entry *, struct net_device *dev, int how);
110 static struct dst_entry *dn_dst_negative_advice(struct dst_entry *);
111 static void dn_dst_link_failure(struct sk_buff *);
112 static void dn_dst_update_pmtu(struct dst_entry *dst, struct sock *sk,
113 			       struct sk_buff *skb , u32 mtu,
114 			       bool confirm_neigh);
115 static void dn_dst_redirect(struct dst_entry *dst, struct sock *sk,
116 			    struct sk_buff *skb);
117 static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst,
118 					     struct sk_buff *skb,
119 					     const void *daddr);
120 static int dn_route_input(struct sk_buff *);
121 static void dn_run_flush(struct timer_list *unused);
122 
123 static struct dn_rt_hash_bucket *dn_rt_hash_table;
124 static unsigned int dn_rt_hash_mask;
125 
126 static struct timer_list dn_route_timer;
127 static DEFINE_TIMER(dn_rt_flush_timer, dn_run_flush);
128 int decnet_dst_gc_interval = 2;
129 
130 static struct dst_ops dn_dst_ops = {
131 	.family =		PF_DECnet,
132 	.gc_thresh =		128,
133 	.gc =			dn_dst_gc,
134 	.check =		dn_dst_check,
135 	.default_advmss =	dn_dst_default_advmss,
136 	.mtu =			dn_dst_mtu,
137 	.cow_metrics =		dst_cow_metrics_generic,
138 	.destroy =		dn_dst_destroy,
139 	.ifdown =		dn_dst_ifdown,
140 	.negative_advice =	dn_dst_negative_advice,
141 	.link_failure =		dn_dst_link_failure,
142 	.update_pmtu =		dn_dst_update_pmtu,
143 	.redirect =		dn_dst_redirect,
144 	.neigh_lookup =		dn_dst_neigh_lookup,
145 };
146 
dn_dst_destroy(struct dst_entry * dst)147 static void dn_dst_destroy(struct dst_entry *dst)
148 {
149 	struct dn_route *rt = (struct dn_route *) dst;
150 
151 	if (rt->n)
152 		neigh_release(rt->n);
153 	dst_destroy_metrics_generic(dst);
154 }
155 
dn_dst_ifdown(struct dst_entry * dst,struct net_device * dev,int how)156 static void dn_dst_ifdown(struct dst_entry *dst, struct net_device *dev, int how)
157 {
158 	if (how) {
159 		struct dn_route *rt = (struct dn_route *) dst;
160 		struct neighbour *n = rt->n;
161 
162 		if (n && n->dev == dev) {
163 			n->dev = dev_net(dev)->loopback_dev;
164 			dev_hold(n->dev);
165 			dev_put(dev);
166 		}
167 	}
168 }
169 
dn_hash(__le16 src,__le16 dst)170 static __inline__ unsigned int dn_hash(__le16 src, __le16 dst)
171 {
172 	__u16 tmp = (__u16 __force)(src ^ dst);
173 	tmp ^= (tmp >> 3);
174 	tmp ^= (tmp >> 5);
175 	tmp ^= (tmp >> 10);
176 	return dn_rt_hash_mask & (unsigned int)tmp;
177 }
178 
dn_dst_check_expire(struct timer_list * unused)179 static void dn_dst_check_expire(struct timer_list *unused)
180 {
181 	int i;
182 	struct dn_route *rt;
183 	struct dn_route __rcu **rtp;
184 	unsigned long now = jiffies;
185 	unsigned long expire = 120 * HZ;
186 
187 	for (i = 0; i <= dn_rt_hash_mask; i++) {
188 		rtp = &dn_rt_hash_table[i].chain;
189 
190 		spin_lock(&dn_rt_hash_table[i].lock);
191 		while ((rt = rcu_dereference_protected(*rtp,
192 						lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) {
193 			if (atomic_read(&rt->dst.__refcnt) > 1 ||
194 			    (now - rt->dst.lastuse) < expire) {
195 				rtp = &rt->dn_next;
196 				continue;
197 			}
198 			*rtp = rt->dn_next;
199 			rt->dn_next = NULL;
200 			dst_dev_put(&rt->dst);
201 			dst_release(&rt->dst);
202 		}
203 		spin_unlock(&dn_rt_hash_table[i].lock);
204 
205 		if ((jiffies - now) > 0)
206 			break;
207 	}
208 
209 	mod_timer(&dn_route_timer, now + decnet_dst_gc_interval * HZ);
210 }
211 
dn_dst_gc(struct dst_ops * ops)212 static int dn_dst_gc(struct dst_ops *ops)
213 {
214 	struct dn_route *rt;
215 	struct dn_route __rcu **rtp;
216 	int i;
217 	unsigned long now = jiffies;
218 	unsigned long expire = 10 * HZ;
219 
220 	for (i = 0; i <= dn_rt_hash_mask; i++) {
221 
222 		spin_lock_bh(&dn_rt_hash_table[i].lock);
223 		rtp = &dn_rt_hash_table[i].chain;
224 
225 		while ((rt = rcu_dereference_protected(*rtp,
226 						lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) {
227 			if (atomic_read(&rt->dst.__refcnt) > 1 ||
228 			    (now - rt->dst.lastuse) < expire) {
229 				rtp = &rt->dn_next;
230 				continue;
231 			}
232 			*rtp = rt->dn_next;
233 			rt->dn_next = NULL;
234 			dst_dev_put(&rt->dst);
235 			dst_release(&rt->dst);
236 			break;
237 		}
238 		spin_unlock_bh(&dn_rt_hash_table[i].lock);
239 	}
240 
241 	return 0;
242 }
243 
244 /*
245  * The decnet standards don't impose a particular minimum mtu, what they
246  * do insist on is that the routing layer accepts a datagram of at least
247  * 230 bytes long. Here we have to subtract the routing header length from
248  * 230 to get the minimum acceptable mtu. If there is no neighbour, then we
249  * assume the worst and use a long header size.
250  *
251  * We update both the mtu and the advertised mss (i.e. the segment size we
252  * advertise to the other end).
253  */
dn_dst_update_pmtu(struct dst_entry * dst,struct sock * sk,struct sk_buff * skb,u32 mtu,bool confirm_neigh)254 static void dn_dst_update_pmtu(struct dst_entry *dst, struct sock *sk,
255 			       struct sk_buff *skb, u32 mtu,
256 			       bool confirm_neigh)
257 {
258 	struct dn_route *rt = (struct dn_route *) dst;
259 	struct neighbour *n = rt->n;
260 	u32 min_mtu = 230;
261 	struct dn_dev *dn;
262 
263 	dn = n ? rcu_dereference_raw(n->dev->dn_ptr) : NULL;
264 
265 	if (dn && dn->use_long == 0)
266 		min_mtu -= 6;
267 	else
268 		min_mtu -= 21;
269 
270 	if (dst_metric(dst, RTAX_MTU) > mtu && mtu >= min_mtu) {
271 		if (!(dst_metric_locked(dst, RTAX_MTU))) {
272 			dst_metric_set(dst, RTAX_MTU, mtu);
273 			dst_set_expires(dst, dn_rt_mtu_expires);
274 		}
275 		if (!(dst_metric_locked(dst, RTAX_ADVMSS))) {
276 			u32 mss = mtu - DN_MAX_NSP_DATA_HEADER;
277 			u32 existing_mss = dst_metric_raw(dst, RTAX_ADVMSS);
278 			if (!existing_mss || existing_mss > mss)
279 				dst_metric_set(dst, RTAX_ADVMSS, mss);
280 		}
281 	}
282 }
283 
dn_dst_redirect(struct dst_entry * dst,struct sock * sk,struct sk_buff * skb)284 static void dn_dst_redirect(struct dst_entry *dst, struct sock *sk,
285 			    struct sk_buff *skb)
286 {
287 }
288 
289 /*
290  * When a route has been marked obsolete. (e.g. routing cache flush)
291  */
dn_dst_check(struct dst_entry * dst,__u32 cookie)292 static struct dst_entry *dn_dst_check(struct dst_entry *dst, __u32 cookie)
293 {
294 	return NULL;
295 }
296 
dn_dst_negative_advice(struct dst_entry * dst)297 static struct dst_entry *dn_dst_negative_advice(struct dst_entry *dst)
298 {
299 	dst_release(dst);
300 	return NULL;
301 }
302 
dn_dst_link_failure(struct sk_buff * skb)303 static void dn_dst_link_failure(struct sk_buff *skb)
304 {
305 }
306 
compare_keys(struct flowidn * fl1,struct flowidn * fl2)307 static inline int compare_keys(struct flowidn *fl1, struct flowidn *fl2)
308 {
309 	return ((fl1->daddr ^ fl2->daddr) |
310 		(fl1->saddr ^ fl2->saddr) |
311 		(fl1->flowidn_mark ^ fl2->flowidn_mark) |
312 		(fl1->flowidn_scope ^ fl2->flowidn_scope) |
313 		(fl1->flowidn_oif ^ fl2->flowidn_oif) |
314 		(fl1->flowidn_iif ^ fl2->flowidn_iif)) == 0;
315 }
316 
dn_insert_route(struct dn_route * rt,unsigned int hash,struct dn_route ** rp)317 static int dn_insert_route(struct dn_route *rt, unsigned int hash, struct dn_route **rp)
318 {
319 	struct dn_route *rth;
320 	struct dn_route __rcu **rthp;
321 	unsigned long now = jiffies;
322 
323 	rthp = &dn_rt_hash_table[hash].chain;
324 
325 	spin_lock_bh(&dn_rt_hash_table[hash].lock);
326 	while ((rth = rcu_dereference_protected(*rthp,
327 						lockdep_is_held(&dn_rt_hash_table[hash].lock))) != NULL) {
328 		if (compare_keys(&rth->fld, &rt->fld)) {
329 			/* Put it first */
330 			*rthp = rth->dn_next;
331 			rcu_assign_pointer(rth->dn_next,
332 					   dn_rt_hash_table[hash].chain);
333 			rcu_assign_pointer(dn_rt_hash_table[hash].chain, rth);
334 
335 			dst_hold_and_use(&rth->dst, now);
336 			spin_unlock_bh(&dn_rt_hash_table[hash].lock);
337 
338 			dst_release_immediate(&rt->dst);
339 			*rp = rth;
340 			return 0;
341 		}
342 		rthp = &rth->dn_next;
343 	}
344 
345 	rcu_assign_pointer(rt->dn_next, dn_rt_hash_table[hash].chain);
346 	rcu_assign_pointer(dn_rt_hash_table[hash].chain, rt);
347 
348 	dst_hold_and_use(&rt->dst, now);
349 	spin_unlock_bh(&dn_rt_hash_table[hash].lock);
350 	*rp = rt;
351 	return 0;
352 }
353 
dn_run_flush(struct timer_list * unused)354 static void dn_run_flush(struct timer_list *unused)
355 {
356 	int i;
357 	struct dn_route *rt, *next;
358 
359 	for (i = 0; i < dn_rt_hash_mask; i++) {
360 		spin_lock_bh(&dn_rt_hash_table[i].lock);
361 
362 		if ((rt = xchg((struct dn_route **)&dn_rt_hash_table[i].chain, NULL)) == NULL)
363 			goto nothing_to_declare;
364 
365 		for(; rt; rt = next) {
366 			next = rcu_dereference_raw(rt->dn_next);
367 			RCU_INIT_POINTER(rt->dn_next, NULL);
368 			dst_dev_put(&rt->dst);
369 			dst_release(&rt->dst);
370 		}
371 
372 nothing_to_declare:
373 		spin_unlock_bh(&dn_rt_hash_table[i].lock);
374 	}
375 }
376 
377 static DEFINE_SPINLOCK(dn_rt_flush_lock);
378 
dn_rt_cache_flush(int delay)379 void dn_rt_cache_flush(int delay)
380 {
381 	unsigned long now = jiffies;
382 	int user_mode = !in_interrupt();
383 
384 	if (delay < 0)
385 		delay = dn_rt_min_delay;
386 
387 	spin_lock_bh(&dn_rt_flush_lock);
388 
389 	if (del_timer(&dn_rt_flush_timer) && delay > 0 && dn_rt_deadline) {
390 		long tmo = (long)(dn_rt_deadline - now);
391 
392 		if (user_mode && tmo < dn_rt_max_delay - dn_rt_min_delay)
393 			tmo = 0;
394 
395 		if (delay > tmo)
396 			delay = tmo;
397 	}
398 
399 	if (delay <= 0) {
400 		spin_unlock_bh(&dn_rt_flush_lock);
401 		dn_run_flush(NULL);
402 		return;
403 	}
404 
405 	if (dn_rt_deadline == 0)
406 		dn_rt_deadline = now + dn_rt_max_delay;
407 
408 	dn_rt_flush_timer.expires = now + delay;
409 	add_timer(&dn_rt_flush_timer);
410 	spin_unlock_bh(&dn_rt_flush_lock);
411 }
412 
413 /**
414  * dn_return_short - Return a short packet to its sender
415  * @skb: The packet to return
416  *
417  */
dn_return_short(struct sk_buff * skb)418 static int dn_return_short(struct sk_buff *skb)
419 {
420 	struct dn_skb_cb *cb;
421 	unsigned char *ptr;
422 	__le16 *src;
423 	__le16 *dst;
424 
425 	/* Add back headers */
426 	skb_push(skb, skb->data - skb_network_header(skb));
427 
428 	if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
429 		return NET_RX_DROP;
430 
431 	cb = DN_SKB_CB(skb);
432 	/* Skip packet length and point to flags */
433 	ptr = skb->data + 2;
434 	*ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
435 
436 	dst = (__le16 *)ptr;
437 	ptr += 2;
438 	src = (__le16 *)ptr;
439 	ptr += 2;
440 	*ptr = 0; /* Zero hop count */
441 
442 	swap(*src, *dst);
443 
444 	skb->pkt_type = PACKET_OUTGOING;
445 	dn_rt_finish_output(skb, NULL, NULL);
446 	return NET_RX_SUCCESS;
447 }
448 
449 /**
450  * dn_return_long - Return a long packet to its sender
451  * @skb: The long format packet to return
452  *
453  */
dn_return_long(struct sk_buff * skb)454 static int dn_return_long(struct sk_buff *skb)
455 {
456 	struct dn_skb_cb *cb;
457 	unsigned char *ptr;
458 	unsigned char *src_addr, *dst_addr;
459 	unsigned char tmp[ETH_ALEN];
460 
461 	/* Add back all headers */
462 	skb_push(skb, skb->data - skb_network_header(skb));
463 
464 	if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
465 		return NET_RX_DROP;
466 
467 	cb = DN_SKB_CB(skb);
468 	/* Ignore packet length and point to flags */
469 	ptr = skb->data + 2;
470 
471 	/* Skip padding */
472 	if (*ptr & DN_RT_F_PF) {
473 		char padlen = (*ptr & ~DN_RT_F_PF);
474 		ptr += padlen;
475 	}
476 
477 	*ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
478 	ptr += 2;
479 	dst_addr = ptr;
480 	ptr += 8;
481 	src_addr = ptr;
482 	ptr += 6;
483 	*ptr = 0; /* Zero hop count */
484 
485 	/* Swap source and destination */
486 	memcpy(tmp, src_addr, ETH_ALEN);
487 	memcpy(src_addr, dst_addr, ETH_ALEN);
488 	memcpy(dst_addr, tmp, ETH_ALEN);
489 
490 	skb->pkt_type = PACKET_OUTGOING;
491 	dn_rt_finish_output(skb, dst_addr, src_addr);
492 	return NET_RX_SUCCESS;
493 }
494 
495 /**
496  * dn_route_rx_packet - Try and find a route for an incoming packet
497  * @skb: The packet to find a route for
498  *
499  * Returns: result of input function if route is found, error code otherwise
500  */
dn_route_rx_packet(struct net * net,struct sock * sk,struct sk_buff * skb)501 static int dn_route_rx_packet(struct net *net, struct sock *sk, struct sk_buff *skb)
502 {
503 	struct dn_skb_cb *cb;
504 	int err;
505 
506 	if ((err = dn_route_input(skb)) == 0)
507 		return dst_input(skb);
508 
509 	cb = DN_SKB_CB(skb);
510 	if (decnet_debug_level & 4) {
511 		char *devname = skb->dev ? skb->dev->name : "???";
512 
513 		printk(KERN_DEBUG
514 			"DECnet: dn_route_rx_packet: rt_flags=0x%02x dev=%s len=%d src=0x%04hx dst=0x%04hx err=%d type=%d\n",
515 			(int)cb->rt_flags, devname, skb->len,
516 			le16_to_cpu(cb->src), le16_to_cpu(cb->dst),
517 			err, skb->pkt_type);
518 	}
519 
520 	if ((skb->pkt_type == PACKET_HOST) && (cb->rt_flags & DN_RT_F_RQR)) {
521 		switch (cb->rt_flags & DN_RT_PKT_MSK) {
522 		case DN_RT_PKT_SHORT:
523 			return dn_return_short(skb);
524 		case DN_RT_PKT_LONG:
525 			return dn_return_long(skb);
526 		}
527 	}
528 
529 	kfree_skb(skb);
530 	return NET_RX_DROP;
531 }
532 
dn_route_rx_long(struct sk_buff * skb)533 static int dn_route_rx_long(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, 21)) /* 20 for long header, 1 for shortest nsp */
539 		goto drop_it;
540 
541 	skb_pull(skb, 20);
542 	skb_reset_transport_header(skb);
543 
544 	/* Destination info */
545 	ptr += 2;
546 	cb->dst = dn_eth2dn(ptr);
547 	if (memcmp(ptr, dn_hiord_addr, 4) != 0)
548 		goto drop_it;
549 	ptr += 6;
550 
551 
552 	/* Source info */
553 	ptr += 2;
554 	cb->src = dn_eth2dn(ptr);
555 	if (memcmp(ptr, dn_hiord_addr, 4) != 0)
556 		goto drop_it;
557 	ptr += 6;
558 	/* Other junk */
559 	ptr++;
560 	cb->hops = *ptr++; /* Visit Count */
561 
562 	return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING,
563 		       &init_net, NULL, skb, skb->dev, NULL,
564 		       dn_route_rx_packet);
565 
566 drop_it:
567 	kfree_skb(skb);
568 	return NET_RX_DROP;
569 }
570 
571 
572 
dn_route_rx_short(struct sk_buff * skb)573 static int dn_route_rx_short(struct sk_buff *skb)
574 {
575 	struct dn_skb_cb *cb = DN_SKB_CB(skb);
576 	unsigned char *ptr = skb->data;
577 
578 	if (!pskb_may_pull(skb, 6)) /* 5 for short header + 1 for shortest nsp */
579 		goto drop_it;
580 
581 	skb_pull(skb, 5);
582 	skb_reset_transport_header(skb);
583 
584 	cb->dst = *(__le16 *)ptr;
585 	ptr += 2;
586 	cb->src = *(__le16 *)ptr;
587 	ptr += 2;
588 	cb->hops = *ptr & 0x3f;
589 
590 	return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING,
591 		       &init_net, NULL, skb, skb->dev, NULL,
592 		       dn_route_rx_packet);
593 
594 drop_it:
595 	kfree_skb(skb);
596 	return NET_RX_DROP;
597 }
598 
dn_route_discard(struct net * net,struct sock * sk,struct sk_buff * skb)599 static int dn_route_discard(struct net *net, struct sock *sk, struct sk_buff *skb)
600 {
601 	/*
602 	 * I know we drop the packet here, but thats considered success in
603 	 * this case
604 	 */
605 	kfree_skb(skb);
606 	return NET_RX_SUCCESS;
607 }
608 
dn_route_ptp_hello(struct net * net,struct sock * sk,struct sk_buff * skb)609 static int dn_route_ptp_hello(struct net *net, struct sock *sk, struct sk_buff *skb)
610 {
611 	dn_dev_hello(skb);
612 	dn_neigh_pointopoint_hello(skb);
613 	return NET_RX_SUCCESS;
614 }
615 
dn_route_rcv(struct sk_buff * skb,struct net_device * dev,struct packet_type * pt,struct net_device * orig_dev)616 int dn_route_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
617 {
618 	struct dn_skb_cb *cb;
619 	unsigned char flags = 0;
620 	__u16 len = le16_to_cpu(*(__le16 *)skb->data);
621 	struct dn_dev *dn = rcu_dereference(dev->dn_ptr);
622 	unsigned char padlen = 0;
623 
624 	if (!net_eq(dev_net(dev), &init_net))
625 		goto dump_it;
626 
627 	if (dn == NULL)
628 		goto dump_it;
629 
630 	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
631 		goto out;
632 
633 	if (!pskb_may_pull(skb, 3))
634 		goto dump_it;
635 
636 	skb_pull(skb, 2);
637 
638 	if (len > skb->len)
639 		goto dump_it;
640 
641 	skb_trim(skb, len);
642 
643 	flags = *skb->data;
644 
645 	cb = DN_SKB_CB(skb);
646 	cb->stamp = jiffies;
647 	cb->iif = dev->ifindex;
648 
649 	/*
650 	 * If we have padding, remove it.
651 	 */
652 	if (flags & DN_RT_F_PF) {
653 		padlen = flags & ~DN_RT_F_PF;
654 		if (!pskb_may_pull(skb, padlen + 1))
655 			goto dump_it;
656 		skb_pull(skb, padlen);
657 		flags = *skb->data;
658 	}
659 
660 	skb_reset_network_header(skb);
661 
662 	/*
663 	 * Weed out future version DECnet
664 	 */
665 	if (flags & DN_RT_F_VER)
666 		goto dump_it;
667 
668 	cb->rt_flags = flags;
669 
670 	if (decnet_debug_level & 1)
671 		printk(KERN_DEBUG
672 			"dn_route_rcv: got 0x%02x from %s [%d %d %d]\n",
673 			(int)flags, (dev) ? dev->name : "???", len, skb->len,
674 			padlen);
675 
676 	if (flags & DN_RT_PKT_CNTL) {
677 		if (unlikely(skb_linearize(skb)))
678 			goto dump_it;
679 
680 		switch (flags & DN_RT_CNTL_MSK) {
681 		case DN_RT_PKT_INIT:
682 			dn_dev_init_pkt(skb);
683 			break;
684 		case DN_RT_PKT_VERI:
685 			dn_dev_veri_pkt(skb);
686 			break;
687 		}
688 
689 		if (dn->parms.state != DN_DEV_S_RU)
690 			goto dump_it;
691 
692 		switch (flags & DN_RT_CNTL_MSK) {
693 		case DN_RT_PKT_HELO:
694 			return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
695 				       &init_net, NULL, skb, skb->dev, NULL,
696 				       dn_route_ptp_hello);
697 
698 		case DN_RT_PKT_L1RT:
699 		case DN_RT_PKT_L2RT:
700 			return NF_HOOK(NFPROTO_DECNET, NF_DN_ROUTE,
701 				       &init_net, NULL, skb, skb->dev, NULL,
702 				       dn_route_discard);
703 		case DN_RT_PKT_ERTH:
704 			return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
705 				       &init_net, NULL, skb, skb->dev, NULL,
706 				       dn_neigh_router_hello);
707 
708 		case DN_RT_PKT_EEDH:
709 			return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
710 				       &init_net, NULL, skb, skb->dev, NULL,
711 				       dn_neigh_endnode_hello);
712 		}
713 	} else {
714 		if (dn->parms.state != DN_DEV_S_RU)
715 			goto dump_it;
716 
717 		skb_pull(skb, 1); /* Pull flags */
718 
719 		switch (flags & DN_RT_PKT_MSK) {
720 		case DN_RT_PKT_LONG:
721 			return dn_route_rx_long(skb);
722 		case DN_RT_PKT_SHORT:
723 			return dn_route_rx_short(skb);
724 		}
725 	}
726 
727 dump_it:
728 	kfree_skb(skb);
729 out:
730 	return NET_RX_DROP;
731 }
732 
dn_output(struct net * net,struct sock * sk,struct sk_buff * skb)733 static int dn_output(struct net *net, struct sock *sk, struct sk_buff *skb)
734 {
735 	struct dst_entry *dst = skb_dst(skb);
736 	struct dn_route *rt = (struct dn_route *)dst;
737 	struct net_device *dev = dst->dev;
738 	struct dn_skb_cb *cb = DN_SKB_CB(skb);
739 
740 	int err = -EINVAL;
741 
742 	if (rt->n == NULL)
743 		goto error;
744 
745 	skb->dev = dev;
746 
747 	cb->src = rt->rt_saddr;
748 	cb->dst = rt->rt_daddr;
749 
750 	/*
751 	 * Always set the Intra-Ethernet bit on all outgoing packets
752 	 * originated on this node. Only valid flag from upper layers
753 	 * is return-to-sender-requested. Set hop count to 0 too.
754 	 */
755 	cb->rt_flags &= ~DN_RT_F_RQR;
756 	cb->rt_flags |= DN_RT_F_IE;
757 	cb->hops = 0;
758 
759 	return NF_HOOK(NFPROTO_DECNET, NF_DN_LOCAL_OUT,
760 		       &init_net, sk, skb, NULL, dev,
761 		       dn_to_neigh_output);
762 
763 error:
764 	net_dbg_ratelimited("dn_output: This should not happen\n");
765 
766 	kfree_skb(skb);
767 
768 	return err;
769 }
770 
dn_forward(struct sk_buff * skb)771 static int dn_forward(struct sk_buff *skb)
772 {
773 	struct dn_skb_cb *cb = DN_SKB_CB(skb);
774 	struct dst_entry *dst = skb_dst(skb);
775 	struct dn_dev *dn_db = rcu_dereference(dst->dev->dn_ptr);
776 	struct dn_route *rt;
777 	int header_len;
778 	struct net_device *dev = skb->dev;
779 
780 	if (skb->pkt_type != PACKET_HOST)
781 		goto drop;
782 
783 	/* Ensure that we have enough space for headers */
784 	rt = (struct dn_route *)skb_dst(skb);
785 	header_len = dn_db->use_long ? 21 : 6;
786 	if (skb_cow(skb, LL_RESERVED_SPACE(rt->dst.dev)+header_len))
787 		goto drop;
788 
789 	/*
790 	 * Hop count exceeded.
791 	 */
792 	if (++cb->hops > 30)
793 		goto drop;
794 
795 	skb->dev = rt->dst.dev;
796 
797 	/*
798 	 * If packet goes out same interface it came in on, then set
799 	 * the Intra-Ethernet bit. This has no effect for short
800 	 * packets, so we don't need to test for them here.
801 	 */
802 	cb->rt_flags &= ~DN_RT_F_IE;
803 	if (rt->rt_flags & RTCF_DOREDIRECT)
804 		cb->rt_flags |= DN_RT_F_IE;
805 
806 	return NF_HOOK(NFPROTO_DECNET, NF_DN_FORWARD,
807 		       &init_net, NULL, skb, dev, skb->dev,
808 		       dn_to_neigh_output);
809 
810 drop:
811 	kfree_skb(skb);
812 	return NET_RX_DROP;
813 }
814 
815 /*
816  * Used to catch bugs. This should never normally get
817  * called.
818  */
dn_rt_bug_out(struct net * net,struct sock * sk,struct sk_buff * skb)819 static int dn_rt_bug_out(struct net *net, struct sock *sk, struct sk_buff *skb)
820 {
821 	struct dn_skb_cb *cb = DN_SKB_CB(skb);
822 
823 	net_dbg_ratelimited("dn_rt_bug: skb from:%04x to:%04x\n",
824 			    le16_to_cpu(cb->src), le16_to_cpu(cb->dst));
825 
826 	kfree_skb(skb);
827 
828 	return NET_RX_DROP;
829 }
830 
dn_rt_bug(struct sk_buff * skb)831 static int dn_rt_bug(struct sk_buff *skb)
832 {
833 	struct dn_skb_cb *cb = DN_SKB_CB(skb);
834 
835 	net_dbg_ratelimited("dn_rt_bug: skb from:%04x to:%04x\n",
836 			    le16_to_cpu(cb->src), le16_to_cpu(cb->dst));
837 
838 	kfree_skb(skb);
839 
840 	return NET_RX_DROP;
841 }
842 
dn_dst_default_advmss(const struct dst_entry * dst)843 static unsigned int dn_dst_default_advmss(const struct dst_entry *dst)
844 {
845 	return dn_mss_from_pmtu(dst->dev, dst_mtu(dst));
846 }
847 
dn_dst_mtu(const struct dst_entry * dst)848 static unsigned int dn_dst_mtu(const struct dst_entry *dst)
849 {
850 	unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
851 
852 	return mtu ? : dst->dev->mtu;
853 }
854 
dn_dst_neigh_lookup(const struct dst_entry * dst,struct sk_buff * skb,const void * daddr)855 static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst,
856 					     struct sk_buff *skb,
857 					     const void *daddr)
858 {
859 	return __neigh_lookup_errno(&dn_neigh_table, daddr, dst->dev);
860 }
861 
dn_rt_set_next_hop(struct dn_route * rt,struct dn_fib_res * res)862 static int dn_rt_set_next_hop(struct dn_route *rt, struct dn_fib_res *res)
863 {
864 	struct dn_fib_info *fi = res->fi;
865 	struct net_device *dev = rt->dst.dev;
866 	unsigned int mss_metric;
867 	struct neighbour *n;
868 
869 	if (fi) {
870 		if (DN_FIB_RES_GW(*res) &&
871 		    DN_FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
872 			rt->rt_gateway = DN_FIB_RES_GW(*res);
873 		dst_init_metrics(&rt->dst, fi->fib_metrics, true);
874 	}
875 	rt->rt_type = res->type;
876 
877 	if (dev != NULL && rt->n == NULL) {
878 		n = __neigh_lookup_errno(&dn_neigh_table, &rt->rt_gateway, dev);
879 		if (IS_ERR(n))
880 			return PTR_ERR(n);
881 		rt->n = n;
882 	}
883 
884 	if (dst_metric(&rt->dst, RTAX_MTU) > rt->dst.dev->mtu)
885 		dst_metric_set(&rt->dst, RTAX_MTU, rt->dst.dev->mtu);
886 	mss_metric = dst_metric_raw(&rt->dst, RTAX_ADVMSS);
887 	if (mss_metric) {
888 		unsigned int mss = dn_mss_from_pmtu(dev, dst_mtu(&rt->dst));
889 		if (mss_metric > mss)
890 			dst_metric_set(&rt->dst, RTAX_ADVMSS, mss);
891 	}
892 	return 0;
893 }
894 
dn_match_addr(__le16 addr1,__le16 addr2)895 static inline int dn_match_addr(__le16 addr1, __le16 addr2)
896 {
897 	__u16 tmp = le16_to_cpu(addr1) ^ le16_to_cpu(addr2);
898 	int match = 16;
899 	while(tmp) {
900 		tmp >>= 1;
901 		match--;
902 	}
903 	return match;
904 }
905 
dnet_select_source(const struct net_device * dev,__le16 daddr,int scope)906 static __le16 dnet_select_source(const struct net_device *dev, __le16 daddr, int scope)
907 {
908 	__le16 saddr = 0;
909 	struct dn_dev *dn_db;
910 	struct dn_ifaddr *ifa;
911 	int best_match = 0;
912 	int ret;
913 
914 	rcu_read_lock();
915 	dn_db = rcu_dereference(dev->dn_ptr);
916 	for (ifa = rcu_dereference(dn_db->ifa_list);
917 	     ifa != NULL;
918 	     ifa = rcu_dereference(ifa->ifa_next)) {
919 		if (ifa->ifa_scope > scope)
920 			continue;
921 		if (!daddr) {
922 			saddr = ifa->ifa_local;
923 			break;
924 		}
925 		ret = dn_match_addr(daddr, ifa->ifa_local);
926 		if (ret > best_match)
927 			saddr = ifa->ifa_local;
928 		if (best_match == 0)
929 			saddr = ifa->ifa_local;
930 	}
931 	rcu_read_unlock();
932 
933 	return saddr;
934 }
935 
__dn_fib_res_prefsrc(struct dn_fib_res * res)936 static inline __le16 __dn_fib_res_prefsrc(struct dn_fib_res *res)
937 {
938 	return dnet_select_source(DN_FIB_RES_DEV(*res), DN_FIB_RES_GW(*res), res->scope);
939 }
940 
dn_fib_rules_map_destination(__le16 daddr,struct dn_fib_res * res)941 static inline __le16 dn_fib_rules_map_destination(__le16 daddr, struct dn_fib_res *res)
942 {
943 	__le16 mask = dnet_make_mask(res->prefixlen);
944 	return (daddr&~mask)|res->fi->fib_nh->nh_gw;
945 }
946 
dn_route_output_slow(struct dst_entry ** pprt,const struct flowidn * oldflp,int try_hard)947 static int dn_route_output_slow(struct dst_entry **pprt, const struct flowidn *oldflp, int try_hard)
948 {
949 	struct flowidn fld = {
950 		.daddr = oldflp->daddr,
951 		.saddr = oldflp->saddr,
952 		.flowidn_scope = RT_SCOPE_UNIVERSE,
953 		.flowidn_mark = oldflp->flowidn_mark,
954 		.flowidn_iif = LOOPBACK_IFINDEX,
955 		.flowidn_oif = oldflp->flowidn_oif,
956 	};
957 	struct dn_route *rt = NULL;
958 	struct net_device *dev_out = NULL, *dev;
959 	struct neighbour *neigh = NULL;
960 	unsigned int hash;
961 	unsigned int flags = 0;
962 	struct dn_fib_res res = { .fi = NULL, .type = RTN_UNICAST };
963 	int err;
964 	int free_res = 0;
965 	__le16 gateway = 0;
966 
967 	if (decnet_debug_level & 16)
968 		printk(KERN_DEBUG
969 		       "dn_route_output_slow: dst=%04x src=%04x mark=%d"
970 		       " iif=%d oif=%d\n", le16_to_cpu(oldflp->daddr),
971 		       le16_to_cpu(oldflp->saddr),
972 		       oldflp->flowidn_mark, LOOPBACK_IFINDEX,
973 		       oldflp->flowidn_oif);
974 
975 	/* If we have an output interface, verify its a DECnet device */
976 	if (oldflp->flowidn_oif) {
977 		dev_out = dev_get_by_index(&init_net, oldflp->flowidn_oif);
978 		err = -ENODEV;
979 		if (dev_out && dev_out->dn_ptr == NULL) {
980 			dev_put(dev_out);
981 			dev_out = NULL;
982 		}
983 		if (dev_out == NULL)
984 			goto out;
985 	}
986 
987 	/* If we have a source address, verify that its a local address */
988 	if (oldflp->saddr) {
989 		err = -EADDRNOTAVAIL;
990 
991 		if (dev_out) {
992 			if (dn_dev_islocal(dev_out, oldflp->saddr))
993 				goto source_ok;
994 			dev_put(dev_out);
995 			goto out;
996 		}
997 		rcu_read_lock();
998 		for_each_netdev_rcu(&init_net, dev) {
999 			if (!dev->dn_ptr)
1000 				continue;
1001 			if (!dn_dev_islocal(dev, oldflp->saddr))
1002 				continue;
1003 			if ((dev->flags & IFF_LOOPBACK) &&
1004 			    oldflp->daddr &&
1005 			    !dn_dev_islocal(dev, oldflp->daddr))
1006 				continue;
1007 
1008 			dev_out = dev;
1009 			break;
1010 		}
1011 		rcu_read_unlock();
1012 		if (dev_out == NULL)
1013 			goto out;
1014 		dev_hold(dev_out);
1015 source_ok:
1016 		;
1017 	}
1018 
1019 	/* No destination? Assume its local */
1020 	if (!fld.daddr) {
1021 		fld.daddr = fld.saddr;
1022 
1023 		if (dev_out)
1024 			dev_put(dev_out);
1025 		err = -EINVAL;
1026 		dev_out = init_net.loopback_dev;
1027 		if (!dev_out->dn_ptr)
1028 			goto out;
1029 		err = -EADDRNOTAVAIL;
1030 		dev_hold(dev_out);
1031 		if (!fld.daddr) {
1032 			fld.daddr =
1033 			fld.saddr = dnet_select_source(dev_out, 0,
1034 						       RT_SCOPE_HOST);
1035 			if (!fld.daddr)
1036 				goto out;
1037 		}
1038 		fld.flowidn_oif = LOOPBACK_IFINDEX;
1039 		res.type = RTN_LOCAL;
1040 		goto make_route;
1041 	}
1042 
1043 	if (decnet_debug_level & 16)
1044 		printk(KERN_DEBUG
1045 		       "dn_route_output_slow: initial checks complete."
1046 		       " dst=%04x src=%04x oif=%d try_hard=%d\n",
1047 		       le16_to_cpu(fld.daddr), le16_to_cpu(fld.saddr),
1048 		       fld.flowidn_oif, try_hard);
1049 
1050 	/*
1051 	 * N.B. If the kernel is compiled without router support then
1052 	 * dn_fib_lookup() will evaluate to non-zero so this if () block
1053 	 * will always be executed.
1054 	 */
1055 	err = -ESRCH;
1056 	if (try_hard || (err = dn_fib_lookup(&fld, &res)) != 0) {
1057 		struct dn_dev *dn_db;
1058 		if (err != -ESRCH)
1059 			goto out;
1060 		/*
1061 		 * Here the fallback is basically the standard algorithm for
1062 		 * routing in endnodes which is described in the DECnet routing
1063 		 * docs
1064 		 *
1065 		 * If we are not trying hard, look in neighbour cache.
1066 		 * The result is tested to ensure that if a specific output
1067 		 * device/source address was requested, then we honour that
1068 		 * here
1069 		 */
1070 		if (!try_hard) {
1071 			neigh = neigh_lookup_nodev(&dn_neigh_table, &init_net, &fld.daddr);
1072 			if (neigh) {
1073 				if ((oldflp->flowidn_oif &&
1074 				    (neigh->dev->ifindex != oldflp->flowidn_oif)) ||
1075 				    (oldflp->saddr &&
1076 				    (!dn_dev_islocal(neigh->dev,
1077 						     oldflp->saddr)))) {
1078 					neigh_release(neigh);
1079 					neigh = NULL;
1080 				} else {
1081 					if (dev_out)
1082 						dev_put(dev_out);
1083 					if (dn_dev_islocal(neigh->dev, fld.daddr)) {
1084 						dev_out = init_net.loopback_dev;
1085 						res.type = RTN_LOCAL;
1086 					} else {
1087 						dev_out = neigh->dev;
1088 					}
1089 					dev_hold(dev_out);
1090 					goto select_source;
1091 				}
1092 			}
1093 		}
1094 
1095 		/* Not there? Perhaps its a local address */
1096 		if (dev_out == NULL)
1097 			dev_out = dn_dev_get_default();
1098 		err = -ENODEV;
1099 		if (dev_out == NULL)
1100 			goto out;
1101 		dn_db = rcu_dereference_raw(dev_out->dn_ptr);
1102 		if (!dn_db)
1103 			goto e_inval;
1104 		/* Possible improvement - check all devices for local addr */
1105 		if (dn_dev_islocal(dev_out, fld.daddr)) {
1106 			dev_put(dev_out);
1107 			dev_out = init_net.loopback_dev;
1108 			dev_hold(dev_out);
1109 			res.type = RTN_LOCAL;
1110 			goto select_source;
1111 		}
1112 		/* Not local either.... try sending it to the default router */
1113 		neigh = neigh_clone(dn_db->router);
1114 		BUG_ON(neigh && neigh->dev != dev_out);
1115 
1116 		/* Ok then, we assume its directly connected and move on */
1117 select_source:
1118 		if (neigh)
1119 			gateway = ((struct dn_neigh *)neigh)->addr;
1120 		if (gateway == 0)
1121 			gateway = fld.daddr;
1122 		if (fld.saddr == 0) {
1123 			fld.saddr = dnet_select_source(dev_out, gateway,
1124 						       res.type == RTN_LOCAL ?
1125 						       RT_SCOPE_HOST :
1126 						       RT_SCOPE_LINK);
1127 			if (fld.saddr == 0 && res.type != RTN_LOCAL)
1128 				goto e_addr;
1129 		}
1130 		fld.flowidn_oif = dev_out->ifindex;
1131 		goto make_route;
1132 	}
1133 	free_res = 1;
1134 
1135 	if (res.type == RTN_NAT)
1136 		goto e_inval;
1137 
1138 	if (res.type == RTN_LOCAL) {
1139 		if (!fld.saddr)
1140 			fld.saddr = fld.daddr;
1141 		if (dev_out)
1142 			dev_put(dev_out);
1143 		dev_out = init_net.loopback_dev;
1144 		dev_hold(dev_out);
1145 		if (!dev_out->dn_ptr)
1146 			goto e_inval;
1147 		fld.flowidn_oif = dev_out->ifindex;
1148 		if (res.fi)
1149 			dn_fib_info_put(res.fi);
1150 		res.fi = NULL;
1151 		goto make_route;
1152 	}
1153 
1154 	if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1155 		dn_fib_select_multipath(&fld, &res);
1156 
1157 	/*
1158 	 * We could add some logic to deal with default routes here and
1159 	 * get rid of some of the special casing above.
1160 	 */
1161 
1162 	if (!fld.saddr)
1163 		fld.saddr = DN_FIB_RES_PREFSRC(res);
1164 
1165 	if (dev_out)
1166 		dev_put(dev_out);
1167 	dev_out = DN_FIB_RES_DEV(res);
1168 	dev_hold(dev_out);
1169 	fld.flowidn_oif = dev_out->ifindex;
1170 	gateway = DN_FIB_RES_GW(res);
1171 
1172 make_route:
1173 	if (dev_out->flags & IFF_LOOPBACK)
1174 		flags |= RTCF_LOCAL;
1175 
1176 	rt = dst_alloc(&dn_dst_ops, dev_out, 0, DST_OBSOLETE_NONE, DST_HOST);
1177 	if (rt == NULL)
1178 		goto e_nobufs;
1179 
1180 	rt->dn_next = NULL;
1181 	memset(&rt->fld, 0, sizeof(rt->fld));
1182 	rt->fld.saddr        = oldflp->saddr;
1183 	rt->fld.daddr        = oldflp->daddr;
1184 	rt->fld.flowidn_oif  = oldflp->flowidn_oif;
1185 	rt->fld.flowidn_iif  = 0;
1186 	rt->fld.flowidn_mark = oldflp->flowidn_mark;
1187 
1188 	rt->rt_saddr      = fld.saddr;
1189 	rt->rt_daddr      = fld.daddr;
1190 	rt->rt_gateway    = gateway ? gateway : fld.daddr;
1191 	rt->rt_local_src  = fld.saddr;
1192 
1193 	rt->rt_dst_map    = fld.daddr;
1194 	rt->rt_src_map    = fld.saddr;
1195 
1196 	rt->n = neigh;
1197 	neigh = NULL;
1198 
1199 	rt->dst.lastuse = jiffies;
1200 	rt->dst.output  = dn_output;
1201 	rt->dst.input   = dn_rt_bug;
1202 	rt->rt_flags      = flags;
1203 	if (flags & RTCF_LOCAL)
1204 		rt->dst.input = dn_nsp_rx;
1205 
1206 	err = dn_rt_set_next_hop(rt, &res);
1207 	if (err)
1208 		goto e_neighbour;
1209 
1210 	hash = dn_hash(rt->fld.saddr, rt->fld.daddr);
1211 	/* dn_insert_route() increments dst->__refcnt */
1212 	dn_insert_route(rt, hash, (struct dn_route **)pprt);
1213 
1214 done:
1215 	if (neigh)
1216 		neigh_release(neigh);
1217 	if (free_res)
1218 		dn_fib_res_put(&res);
1219 	if (dev_out)
1220 		dev_put(dev_out);
1221 out:
1222 	return err;
1223 
1224 e_addr:
1225 	err = -EADDRNOTAVAIL;
1226 	goto done;
1227 e_inval:
1228 	err = -EINVAL;
1229 	goto done;
1230 e_nobufs:
1231 	err = -ENOBUFS;
1232 	goto done;
1233 e_neighbour:
1234 	dst_release_immediate(&rt->dst);
1235 	goto e_nobufs;
1236 }
1237 
1238 
1239 /*
1240  * N.B. The flags may be moved into the flowi at some future stage.
1241  */
__dn_route_output_key(struct dst_entry ** pprt,const struct flowidn * flp,int flags)1242 static int __dn_route_output_key(struct dst_entry **pprt, const struct flowidn *flp, int flags)
1243 {
1244 	unsigned int hash = dn_hash(flp->saddr, flp->daddr);
1245 	struct dn_route *rt = NULL;
1246 
1247 	if (!(flags & MSG_TRYHARD)) {
1248 		rcu_read_lock_bh();
1249 		for (rt = rcu_dereference_bh(dn_rt_hash_table[hash].chain); rt;
1250 			rt = rcu_dereference_bh(rt->dn_next)) {
1251 			if ((flp->daddr == rt->fld.daddr) &&
1252 			    (flp->saddr == rt->fld.saddr) &&
1253 			    (flp->flowidn_mark == rt->fld.flowidn_mark) &&
1254 			    dn_is_output_route(rt) &&
1255 			    (rt->fld.flowidn_oif == flp->flowidn_oif)) {
1256 				dst_hold_and_use(&rt->dst, jiffies);
1257 				rcu_read_unlock_bh();
1258 				*pprt = &rt->dst;
1259 				return 0;
1260 			}
1261 		}
1262 		rcu_read_unlock_bh();
1263 	}
1264 
1265 	return dn_route_output_slow(pprt, flp, flags);
1266 }
1267 
dn_route_output_key(struct dst_entry ** pprt,struct flowidn * flp,int flags)1268 static int dn_route_output_key(struct dst_entry **pprt, struct flowidn *flp, int flags)
1269 {
1270 	int err;
1271 
1272 	err = __dn_route_output_key(pprt, flp, flags);
1273 	if (err == 0 && flp->flowidn_proto) {
1274 		*pprt = xfrm_lookup(&init_net, *pprt,
1275 				    flowidn_to_flowi(flp), NULL, 0);
1276 		if (IS_ERR(*pprt)) {
1277 			err = PTR_ERR(*pprt);
1278 			*pprt = NULL;
1279 		}
1280 	}
1281 	return err;
1282 }
1283 
dn_route_output_sock(struct dst_entry __rcu ** pprt,struct flowidn * fl,struct sock * sk,int flags)1284 int dn_route_output_sock(struct dst_entry __rcu **pprt, struct flowidn *fl, struct sock *sk, int flags)
1285 {
1286 	int err;
1287 
1288 	err = __dn_route_output_key(pprt, fl, flags & MSG_TRYHARD);
1289 	if (err == 0 && fl->flowidn_proto) {
1290 		*pprt = xfrm_lookup(&init_net, *pprt,
1291 				    flowidn_to_flowi(fl), sk, 0);
1292 		if (IS_ERR(*pprt)) {
1293 			err = PTR_ERR(*pprt);
1294 			*pprt = NULL;
1295 		}
1296 	}
1297 	return err;
1298 }
1299 
dn_route_input_slow(struct sk_buff * skb)1300 static int dn_route_input_slow(struct sk_buff *skb)
1301 {
1302 	struct dn_route *rt = NULL;
1303 	struct dn_skb_cb *cb = DN_SKB_CB(skb);
1304 	struct net_device *in_dev = skb->dev;
1305 	struct net_device *out_dev = NULL;
1306 	struct dn_dev *dn_db;
1307 	struct neighbour *neigh = NULL;
1308 	unsigned int hash;
1309 	int flags = 0;
1310 	__le16 gateway = 0;
1311 	__le16 local_src = 0;
1312 	struct flowidn fld = {
1313 		.daddr = cb->dst,
1314 		.saddr = cb->src,
1315 		.flowidn_scope = RT_SCOPE_UNIVERSE,
1316 		.flowidn_mark = skb->mark,
1317 		.flowidn_iif = skb->dev->ifindex,
1318 	};
1319 	struct dn_fib_res res = { .fi = NULL, .type = RTN_UNREACHABLE };
1320 	int err = -EINVAL;
1321 	int free_res = 0;
1322 
1323 	dev_hold(in_dev);
1324 
1325 	if ((dn_db = rcu_dereference(in_dev->dn_ptr)) == NULL)
1326 		goto out;
1327 
1328 	/* Zero source addresses are not allowed */
1329 	if (fld.saddr == 0)
1330 		goto out;
1331 
1332 	/*
1333 	 * In this case we've just received a packet from a source
1334 	 * outside ourselves pretending to come from us. We don't
1335 	 * allow it any further to prevent routing loops, spoofing and
1336 	 * other nasties. Loopback packets already have the dst attached
1337 	 * so this only affects packets which have originated elsewhere.
1338 	 */
1339 	err  = -ENOTUNIQ;
1340 	if (dn_dev_islocal(in_dev, cb->src))
1341 		goto out;
1342 
1343 	err = dn_fib_lookup(&fld, &res);
1344 	if (err) {
1345 		if (err != -ESRCH)
1346 			goto out;
1347 		/*
1348 		 * Is the destination us ?
1349 		 */
1350 		if (!dn_dev_islocal(in_dev, cb->dst))
1351 			goto e_inval;
1352 
1353 		res.type = RTN_LOCAL;
1354 	} else {
1355 		__le16 src_map = fld.saddr;
1356 		free_res = 1;
1357 
1358 		out_dev = DN_FIB_RES_DEV(res);
1359 		if (out_dev == NULL) {
1360 			net_crit_ratelimited("Bug in dn_route_input_slow() No output device\n");
1361 			goto e_inval;
1362 		}
1363 		dev_hold(out_dev);
1364 
1365 		if (res.r)
1366 			src_map = fld.saddr; /* no NAT support for now */
1367 
1368 		gateway = DN_FIB_RES_GW(res);
1369 		if (res.type == RTN_NAT) {
1370 			fld.daddr = dn_fib_rules_map_destination(fld.daddr, &res);
1371 			dn_fib_res_put(&res);
1372 			free_res = 0;
1373 			if (dn_fib_lookup(&fld, &res))
1374 				goto e_inval;
1375 			free_res = 1;
1376 			if (res.type != RTN_UNICAST)
1377 				goto e_inval;
1378 			flags |= RTCF_DNAT;
1379 			gateway = fld.daddr;
1380 		}
1381 		fld.saddr = src_map;
1382 	}
1383 
1384 	switch(res.type) {
1385 	case RTN_UNICAST:
1386 		/*
1387 		 * Forwarding check here, we only check for forwarding
1388 		 * being turned off, if you want to only forward intra
1389 		 * area, its up to you to set the routing tables up
1390 		 * correctly.
1391 		 */
1392 		if (dn_db->parms.forwarding == 0)
1393 			goto e_inval;
1394 
1395 		if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1396 			dn_fib_select_multipath(&fld, &res);
1397 
1398 		/*
1399 		 * Check for out_dev == in_dev. We use the RTCF_DOREDIRECT
1400 		 * flag as a hint to set the intra-ethernet bit when
1401 		 * forwarding. If we've got NAT in operation, we don't do
1402 		 * this optimisation.
1403 		 */
1404 		if (out_dev == in_dev && !(flags & RTCF_NAT))
1405 			flags |= RTCF_DOREDIRECT;
1406 
1407 		local_src = DN_FIB_RES_PREFSRC(res);
1408 
1409 	case RTN_BLACKHOLE:
1410 	case RTN_UNREACHABLE:
1411 		break;
1412 	case RTN_LOCAL:
1413 		flags |= RTCF_LOCAL;
1414 		fld.saddr = cb->dst;
1415 		fld.daddr = cb->src;
1416 
1417 		/* Routing tables gave us a gateway */
1418 		if (gateway)
1419 			goto make_route;
1420 
1421 		/* Packet was intra-ethernet, so we know its on-link */
1422 		if (cb->rt_flags & DN_RT_F_IE) {
1423 			gateway = cb->src;
1424 			goto make_route;
1425 		}
1426 
1427 		/* Use the default router if there is one */
1428 		neigh = neigh_clone(dn_db->router);
1429 		if (neigh) {
1430 			gateway = ((struct dn_neigh *)neigh)->addr;
1431 			goto make_route;
1432 		}
1433 
1434 		/* Close eyes and pray */
1435 		gateway = cb->src;
1436 		goto make_route;
1437 	default:
1438 		goto e_inval;
1439 	}
1440 
1441 make_route:
1442 	rt = dst_alloc(&dn_dst_ops, out_dev, 1, DST_OBSOLETE_NONE, DST_HOST);
1443 	if (rt == NULL)
1444 		goto e_nobufs;
1445 
1446 	rt->dn_next = NULL;
1447 	memset(&rt->fld, 0, sizeof(rt->fld));
1448 	rt->rt_saddr      = fld.saddr;
1449 	rt->rt_daddr      = fld.daddr;
1450 	rt->rt_gateway    = fld.daddr;
1451 	if (gateway)
1452 		rt->rt_gateway = gateway;
1453 	rt->rt_local_src  = local_src ? local_src : rt->rt_saddr;
1454 
1455 	rt->rt_dst_map    = fld.daddr;
1456 	rt->rt_src_map    = fld.saddr;
1457 
1458 	rt->fld.saddr        = cb->src;
1459 	rt->fld.daddr        = cb->dst;
1460 	rt->fld.flowidn_oif  = 0;
1461 	rt->fld.flowidn_iif  = in_dev->ifindex;
1462 	rt->fld.flowidn_mark = fld.flowidn_mark;
1463 
1464 	rt->n = neigh;
1465 	rt->dst.lastuse = jiffies;
1466 	rt->dst.output = dn_rt_bug_out;
1467 	switch (res.type) {
1468 	case RTN_UNICAST:
1469 		rt->dst.input = dn_forward;
1470 		break;
1471 	case RTN_LOCAL:
1472 		rt->dst.output = dn_output;
1473 		rt->dst.input = dn_nsp_rx;
1474 		rt->dst.dev = in_dev;
1475 		flags |= RTCF_LOCAL;
1476 		break;
1477 	default:
1478 	case RTN_UNREACHABLE:
1479 	case RTN_BLACKHOLE:
1480 		rt->dst.input = dst_discard;
1481 	}
1482 	rt->rt_flags = flags;
1483 
1484 	err = dn_rt_set_next_hop(rt, &res);
1485 	if (err)
1486 		goto e_neighbour;
1487 
1488 	hash = dn_hash(rt->fld.saddr, rt->fld.daddr);
1489 	/* dn_insert_route() increments dst->__refcnt */
1490 	dn_insert_route(rt, hash, &rt);
1491 	skb_dst_set(skb, &rt->dst);
1492 
1493 done:
1494 	if (neigh)
1495 		neigh_release(neigh);
1496 	if (free_res)
1497 		dn_fib_res_put(&res);
1498 	dev_put(in_dev);
1499 	if (out_dev)
1500 		dev_put(out_dev);
1501 out:
1502 	return err;
1503 
1504 e_inval:
1505 	err = -EINVAL;
1506 	goto done;
1507 
1508 e_nobufs:
1509 	err = -ENOBUFS;
1510 	goto done;
1511 
1512 e_neighbour:
1513 	dst_release_immediate(&rt->dst);
1514 	goto done;
1515 }
1516 
dn_route_input(struct sk_buff * skb)1517 static int dn_route_input(struct sk_buff *skb)
1518 {
1519 	struct dn_route *rt;
1520 	struct dn_skb_cb *cb = DN_SKB_CB(skb);
1521 	unsigned int hash = dn_hash(cb->src, cb->dst);
1522 
1523 	if (skb_dst(skb))
1524 		return 0;
1525 
1526 	rcu_read_lock();
1527 	for(rt = rcu_dereference(dn_rt_hash_table[hash].chain); rt != NULL;
1528 	    rt = rcu_dereference(rt->dn_next)) {
1529 		if ((rt->fld.saddr == cb->src) &&
1530 		    (rt->fld.daddr == cb->dst) &&
1531 		    (rt->fld.flowidn_oif == 0) &&
1532 		    (rt->fld.flowidn_mark == skb->mark) &&
1533 		    (rt->fld.flowidn_iif == cb->iif)) {
1534 			dst_hold_and_use(&rt->dst, jiffies);
1535 			rcu_read_unlock();
1536 			skb_dst_set(skb, (struct dst_entry *)rt);
1537 			return 0;
1538 		}
1539 	}
1540 	rcu_read_unlock();
1541 
1542 	return dn_route_input_slow(skb);
1543 }
1544 
dn_rt_fill_info(struct sk_buff * skb,u32 portid,u32 seq,int event,int nowait,unsigned int flags)1545 static int dn_rt_fill_info(struct sk_buff *skb, u32 portid, u32 seq,
1546 			   int event, int nowait, unsigned int flags)
1547 {
1548 	struct dn_route *rt = (struct dn_route *)skb_dst(skb);
1549 	struct rtmsg *r;
1550 	struct nlmsghdr *nlh;
1551 	long expires;
1552 
1553 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
1554 	if (!nlh)
1555 		return -EMSGSIZE;
1556 
1557 	r = nlmsg_data(nlh);
1558 	r->rtm_family = AF_DECnet;
1559 	r->rtm_dst_len = 16;
1560 	r->rtm_src_len = 0;
1561 	r->rtm_tos = 0;
1562 	r->rtm_table = RT_TABLE_MAIN;
1563 	r->rtm_type = rt->rt_type;
1564 	r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
1565 	r->rtm_scope = RT_SCOPE_UNIVERSE;
1566 	r->rtm_protocol = RTPROT_UNSPEC;
1567 
1568 	if (rt->rt_flags & RTCF_NOTIFY)
1569 		r->rtm_flags |= RTM_F_NOTIFY;
1570 
1571 	if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN) < 0 ||
1572 	    nla_put_le16(skb, RTA_DST, rt->rt_daddr) < 0)
1573 		goto errout;
1574 
1575 	if (rt->fld.saddr) {
1576 		r->rtm_src_len = 16;
1577 		if (nla_put_le16(skb, RTA_SRC, rt->fld.saddr) < 0)
1578 			goto errout;
1579 	}
1580 	if (rt->dst.dev &&
1581 	    nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex) < 0)
1582 		goto errout;
1583 
1584 	/*
1585 	 * Note to self - change this if input routes reverse direction when
1586 	 * they deal only with inputs and not with replies like they do
1587 	 * currently.
1588 	 */
1589 	if (nla_put_le16(skb, RTA_PREFSRC, rt->rt_local_src) < 0)
1590 		goto errout;
1591 
1592 	if (rt->rt_daddr != rt->rt_gateway &&
1593 	    nla_put_le16(skb, RTA_GATEWAY, rt->rt_gateway) < 0)
1594 		goto errout;
1595 
1596 	if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
1597 		goto errout;
1598 
1599 	expires = rt->dst.expires ? rt->dst.expires - jiffies : 0;
1600 	if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires,
1601 			       rt->dst.error) < 0)
1602 		goto errout;
1603 
1604 	if (dn_is_input_route(rt) &&
1605 	    nla_put_u32(skb, RTA_IIF, rt->fld.flowidn_iif) < 0)
1606 		goto errout;
1607 
1608 	nlmsg_end(skb, nlh);
1609 	return 0;
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,struct netlink_ext_ack * extack)1633 static int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
1634 			     struct netlink_ext_ack *extack)
1635 {
1636 	struct net *net = sock_net(in_skb->sk);
1637 	struct rtmsg *rtm = nlmsg_data(nlh);
1638 	struct dn_route *rt = NULL;
1639 	struct dn_skb_cb *cb;
1640 	int err;
1641 	struct sk_buff *skb;
1642 	struct flowidn fld;
1643 	struct nlattr *tb[RTA_MAX+1];
1644 
1645 	if (!net_eq(net, &init_net))
1646 		return -EINVAL;
1647 
1648 	err = nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
1649 				     rtm_dn_policy, extack);
1650 	if (err < 0)
1651 		return err;
1652 
1653 	memset(&fld, 0, sizeof(fld));
1654 	fld.flowidn_proto = DNPROTO_NSP;
1655 
1656 	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1657 	if (skb == NULL)
1658 		return -ENOBUFS;
1659 	skb_reset_mac_header(skb);
1660 	cb = DN_SKB_CB(skb);
1661 
1662 	if (tb[RTA_SRC])
1663 		fld.saddr = nla_get_le16(tb[RTA_SRC]);
1664 
1665 	if (tb[RTA_DST])
1666 		fld.daddr = nla_get_le16(tb[RTA_DST]);
1667 
1668 	if (tb[RTA_IIF])
1669 		fld.flowidn_iif = nla_get_u32(tb[RTA_IIF]);
1670 
1671 	if (fld.flowidn_iif) {
1672 		struct net_device *dev;
1673 		dev = __dev_get_by_index(&init_net, fld.flowidn_iif);
1674 		if (!dev || !dev->dn_ptr) {
1675 			kfree_skb(skb);
1676 			return -ENODEV;
1677 		}
1678 		skb->protocol = htons(ETH_P_DNA_RT);
1679 		skb->dev = dev;
1680 		cb->src = fld.saddr;
1681 		cb->dst = fld.daddr;
1682 		local_bh_disable();
1683 		err = dn_route_input(skb);
1684 		local_bh_enable();
1685 		memset(cb, 0, sizeof(struct dn_skb_cb));
1686 		rt = (struct dn_route *)skb_dst(skb);
1687 		if (!err && -rt->dst.error)
1688 			err = rt->dst.error;
1689 	} else {
1690 		if (tb[RTA_OIF])
1691 			fld.flowidn_oif = nla_get_u32(tb[RTA_OIF]);
1692 
1693 		err = dn_route_output_key((struct dst_entry **)&rt, &fld, 0);
1694 	}
1695 
1696 	skb->dev = NULL;
1697 	if (err)
1698 		goto out_free;
1699 	skb_dst_set(skb, &rt->dst);
1700 	if (rtm->rtm_flags & RTM_F_NOTIFY)
1701 		rt->rt_flags |= RTCF_NOTIFY;
1702 
1703 	err = dn_rt_fill_info(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, RTM_NEWROUTE, 0, 0);
1704 	if (err < 0) {
1705 		err = -EMSGSIZE;
1706 		goto out_free;
1707 	}
1708 
1709 	return rtnl_unicast(skb, &init_net, NETLINK_CB(in_skb).portid);
1710 
1711 out_free:
1712 	kfree_skb(skb);
1713 	return err;
1714 }
1715 
1716 /*
1717  * For routers, this is called from dn_fib_dump, but for endnodes its
1718  * called directly from the rtnetlink dispatch table.
1719  */
dn_cache_dump(struct sk_buff * skb,struct netlink_callback * cb)1720 int dn_cache_dump(struct sk_buff *skb, struct netlink_callback *cb)
1721 {
1722 	struct net *net = sock_net(skb->sk);
1723 	struct dn_route *rt;
1724 	int h, s_h;
1725 	int idx, s_idx;
1726 	struct rtmsg *rtm;
1727 
1728 	if (!net_eq(net, &init_net))
1729 		return 0;
1730 
1731 	if (nlmsg_len(cb->nlh) < sizeof(struct rtmsg))
1732 		return -EINVAL;
1733 
1734 	rtm = nlmsg_data(cb->nlh);
1735 	if (!(rtm->rtm_flags & RTM_F_CLONED))
1736 		return 0;
1737 
1738 	s_h = cb->args[0];
1739 	s_idx = idx = cb->args[1];
1740 	for(h = 0; h <= dn_rt_hash_mask; h++) {
1741 		if (h < s_h)
1742 			continue;
1743 		if (h > s_h)
1744 			s_idx = 0;
1745 		rcu_read_lock_bh();
1746 		for(rt = rcu_dereference_bh(dn_rt_hash_table[h].chain), idx = 0;
1747 			rt;
1748 			rt = rcu_dereference_bh(rt->dn_next), idx++) {
1749 			if (idx < s_idx)
1750 				continue;
1751 			skb_dst_set(skb, dst_clone(&rt->dst));
1752 			if (dn_rt_fill_info(skb, NETLINK_CB(cb->skb).portid,
1753 					cb->nlh->nlmsg_seq, RTM_NEWROUTE,
1754 					1, NLM_F_MULTI) < 0) {
1755 				skb_dst_drop(skb);
1756 				rcu_read_unlock_bh();
1757 				goto done;
1758 			}
1759 			skb_dst_drop(skb);
1760 		}
1761 		rcu_read_unlock_bh();
1762 	}
1763 
1764 done:
1765 	cb->args[0] = h;
1766 	cb->args[1] = idx;
1767 	return skb->len;
1768 }
1769 
1770 #ifdef CONFIG_PROC_FS
1771 struct dn_rt_cache_iter_state {
1772 	int bucket;
1773 };
1774 
dn_rt_cache_get_first(struct seq_file * seq)1775 static struct dn_route *dn_rt_cache_get_first(struct seq_file *seq)
1776 {
1777 	struct dn_route *rt = NULL;
1778 	struct dn_rt_cache_iter_state *s = seq->private;
1779 
1780 	for(s->bucket = dn_rt_hash_mask; s->bucket >= 0; --s->bucket) {
1781 		rcu_read_lock_bh();
1782 		rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1783 		if (rt)
1784 			break;
1785 		rcu_read_unlock_bh();
1786 	}
1787 	return rt;
1788 }
1789 
dn_rt_cache_get_next(struct seq_file * seq,struct dn_route * rt)1790 static struct dn_route *dn_rt_cache_get_next(struct seq_file *seq, struct dn_route *rt)
1791 {
1792 	struct dn_rt_cache_iter_state *s = seq->private;
1793 
1794 	rt = rcu_dereference_bh(rt->dn_next);
1795 	while (!rt) {
1796 		rcu_read_unlock_bh();
1797 		if (--s->bucket < 0)
1798 			break;
1799 		rcu_read_lock_bh();
1800 		rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1801 	}
1802 	return rt;
1803 }
1804 
dn_rt_cache_seq_start(struct seq_file * seq,loff_t * pos)1805 static void *dn_rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
1806 {
1807 	struct dn_route *rt = dn_rt_cache_get_first(seq);
1808 
1809 	if (rt) {
1810 		while(*pos && (rt = dn_rt_cache_get_next(seq, rt)))
1811 			--*pos;
1812 	}
1813 	return *pos ? NULL : rt;
1814 }
1815 
dn_rt_cache_seq_next(struct seq_file * seq,void * v,loff_t * pos)1816 static void *dn_rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1817 {
1818 	struct dn_route *rt = dn_rt_cache_get_next(seq, v);
1819 	++*pos;
1820 	return rt;
1821 }
1822 
dn_rt_cache_seq_stop(struct seq_file * seq,void * v)1823 static void dn_rt_cache_seq_stop(struct seq_file *seq, void *v)
1824 {
1825 	if (v)
1826 		rcu_read_unlock_bh();
1827 }
1828 
dn_rt_cache_seq_show(struct seq_file * seq,void * v)1829 static int dn_rt_cache_seq_show(struct seq_file *seq, void *v)
1830 {
1831 	struct dn_route *rt = v;
1832 	char buf1[DN_ASCBUF_LEN], buf2[DN_ASCBUF_LEN];
1833 
1834 	seq_printf(seq, "%-8s %-7s %-7s %04d %04d %04d\n",
1835 		   rt->dst.dev ? rt->dst.dev->name : "*",
1836 		   dn_addr2asc(le16_to_cpu(rt->rt_daddr), buf1),
1837 		   dn_addr2asc(le16_to_cpu(rt->rt_saddr), buf2),
1838 		   atomic_read(&rt->dst.__refcnt),
1839 		   rt->dst.__use, 0);
1840 	return 0;
1841 }
1842 
1843 static const struct seq_operations dn_rt_cache_seq_ops = {
1844 	.start	= dn_rt_cache_seq_start,
1845 	.next	= dn_rt_cache_seq_next,
1846 	.stop	= dn_rt_cache_seq_stop,
1847 	.show	= dn_rt_cache_seq_show,
1848 };
1849 #endif /* CONFIG_PROC_FS */
1850 
dn_route_init(void)1851 void __init dn_route_init(void)
1852 {
1853 	int i, goal, order;
1854 
1855 	dn_dst_ops.kmem_cachep =
1856 		kmem_cache_create("dn_dst_cache", sizeof(struct dn_route), 0,
1857 				  SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
1858 	dst_entries_init(&dn_dst_ops);
1859 	timer_setup(&dn_route_timer, dn_dst_check_expire, 0);
1860 	dn_route_timer.expires = jiffies + decnet_dst_gc_interval * HZ;
1861 	add_timer(&dn_route_timer);
1862 
1863 	goal = totalram_pages() >> (26 - PAGE_SHIFT);
1864 
1865 	for(order = 0; (1UL << order) < goal; order++)
1866 		/* NOTHING */;
1867 
1868 	/*
1869 	 * Only want 1024 entries max, since the table is very, very unlikely
1870 	 * to be larger than that.
1871 	 */
1872 	while(order && ((((1UL << order) * PAGE_SIZE) /
1873 				sizeof(struct dn_rt_hash_bucket)) >= 2048))
1874 		order--;
1875 
1876 	do {
1877 		dn_rt_hash_mask = (1UL << order) * PAGE_SIZE /
1878 			sizeof(struct dn_rt_hash_bucket);
1879 		while(dn_rt_hash_mask & (dn_rt_hash_mask - 1))
1880 			dn_rt_hash_mask--;
1881 		dn_rt_hash_table = (struct dn_rt_hash_bucket *)
1882 			__get_free_pages(GFP_ATOMIC, order);
1883 	} while (dn_rt_hash_table == NULL && --order > 0);
1884 
1885 	if (!dn_rt_hash_table)
1886 		panic("Failed to allocate DECnet route cache hash table\n");
1887 
1888 	printk(KERN_INFO
1889 		"DECnet: Routing cache hash table of %u buckets, %ldKbytes\n",
1890 		dn_rt_hash_mask,
1891 		(long)(dn_rt_hash_mask*sizeof(struct dn_rt_hash_bucket))/1024);
1892 
1893 	dn_rt_hash_mask--;
1894 	for(i = 0; i <= dn_rt_hash_mask; i++) {
1895 		spin_lock_init(&dn_rt_hash_table[i].lock);
1896 		dn_rt_hash_table[i].chain = NULL;
1897 	}
1898 
1899 	dn_dst_ops.gc_thresh = (dn_rt_hash_mask + 1);
1900 
1901 	proc_create_seq_private("decnet_cache", 0444, init_net.proc_net,
1902 			&dn_rt_cache_seq_ops,
1903 			sizeof(struct dn_rt_cache_iter_state), NULL);
1904 
1905 #ifdef CONFIG_DECNET_ROUTER
1906 	rtnl_register_module(THIS_MODULE, PF_DECnet, RTM_GETROUTE,
1907 			     dn_cache_getroute, dn_fib_dump, 0);
1908 #else
1909 	rtnl_register_module(THIS_MODULE, PF_DECnet, RTM_GETROUTE,
1910 			     dn_cache_getroute, dn_cache_dump, 0);
1911 #endif
1912 }
1913 
dn_route_cleanup(void)1914 void __exit dn_route_cleanup(void)
1915 {
1916 	del_timer(&dn_route_timer);
1917 	dn_run_flush(NULL);
1918 
1919 	remove_proc_entry("decnet_cache", init_net.proc_net);
1920 	dst_entries_destroy(&dn_dst_ops);
1921 }
1922