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  * @net: The applicable net namespace
498  * @sk: Socket packet transmitted on
499  * @skb: The packet to find a route for
500  *
501  * Returns: result of input function if route is found, error code otherwise
502  */
dn_route_rx_packet(struct net * net,struct sock * sk,struct sk_buff * skb)503 static int dn_route_rx_packet(struct net *net, struct sock *sk, struct sk_buff *skb)
504 {
505 	struct dn_skb_cb *cb;
506 	int err;
507 
508 	if ((err = dn_route_input(skb)) == 0)
509 		return dst_input(skb);
510 
511 	cb = DN_SKB_CB(skb);
512 	if (decnet_debug_level & 4) {
513 		char *devname = skb->dev ? skb->dev->name : "???";
514 
515 		printk(KERN_DEBUG
516 			"DECnet: dn_route_rx_packet: rt_flags=0x%02x dev=%s len=%d src=0x%04hx dst=0x%04hx err=%d type=%d\n",
517 			(int)cb->rt_flags, devname, skb->len,
518 			le16_to_cpu(cb->src), le16_to_cpu(cb->dst),
519 			err, skb->pkt_type);
520 	}
521 
522 	if ((skb->pkt_type == PACKET_HOST) && (cb->rt_flags & DN_RT_F_RQR)) {
523 		switch (cb->rt_flags & DN_RT_PKT_MSK) {
524 		case DN_RT_PKT_SHORT:
525 			return dn_return_short(skb);
526 		case DN_RT_PKT_LONG:
527 			return dn_return_long(skb);
528 		}
529 	}
530 
531 	kfree_skb(skb);
532 	return NET_RX_DROP;
533 }
534 
dn_route_rx_long(struct sk_buff * skb)535 static int dn_route_rx_long(struct sk_buff *skb)
536 {
537 	struct dn_skb_cb *cb = DN_SKB_CB(skb);
538 	unsigned char *ptr = skb->data;
539 
540 	if (!pskb_may_pull(skb, 21)) /* 20 for long header, 1 for shortest nsp */
541 		goto drop_it;
542 
543 	skb_pull(skb, 20);
544 	skb_reset_transport_header(skb);
545 
546 	/* Destination info */
547 	ptr += 2;
548 	cb->dst = dn_eth2dn(ptr);
549 	if (memcmp(ptr, dn_hiord_addr, 4) != 0)
550 		goto drop_it;
551 	ptr += 6;
552 
553 
554 	/* Source info */
555 	ptr += 2;
556 	cb->src = dn_eth2dn(ptr);
557 	if (memcmp(ptr, dn_hiord_addr, 4) != 0)
558 		goto drop_it;
559 	ptr += 6;
560 	/* Other junk */
561 	ptr++;
562 	cb->hops = *ptr++; /* Visit Count */
563 
564 	return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING,
565 		       &init_net, NULL, skb, skb->dev, NULL,
566 		       dn_route_rx_packet);
567 
568 drop_it:
569 	kfree_skb(skb);
570 	return NET_RX_DROP;
571 }
572 
573 
574 
dn_route_rx_short(struct sk_buff * skb)575 static int dn_route_rx_short(struct sk_buff *skb)
576 {
577 	struct dn_skb_cb *cb = DN_SKB_CB(skb);
578 	unsigned char *ptr = skb->data;
579 
580 	if (!pskb_may_pull(skb, 6)) /* 5 for short header + 1 for shortest nsp */
581 		goto drop_it;
582 
583 	skb_pull(skb, 5);
584 	skb_reset_transport_header(skb);
585 
586 	cb->dst = *(__le16 *)ptr;
587 	ptr += 2;
588 	cb->src = *(__le16 *)ptr;
589 	ptr += 2;
590 	cb->hops = *ptr & 0x3f;
591 
592 	return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING,
593 		       &init_net, NULL, skb, skb->dev, NULL,
594 		       dn_route_rx_packet);
595 
596 drop_it:
597 	kfree_skb(skb);
598 	return NET_RX_DROP;
599 }
600 
dn_route_discard(struct net * net,struct sock * sk,struct sk_buff * skb)601 static int dn_route_discard(struct net *net, struct sock *sk, struct sk_buff *skb)
602 {
603 	/*
604 	 * I know we drop the packet here, but thats considered success in
605 	 * this case
606 	 */
607 	kfree_skb(skb);
608 	return NET_RX_SUCCESS;
609 }
610 
dn_route_ptp_hello(struct net * net,struct sock * sk,struct sk_buff * skb)611 static int dn_route_ptp_hello(struct net *net, struct sock *sk, struct sk_buff *skb)
612 {
613 	dn_dev_hello(skb);
614 	dn_neigh_pointopoint_hello(skb);
615 	return NET_RX_SUCCESS;
616 }
617 
dn_route_rcv(struct sk_buff * skb,struct net_device * dev,struct packet_type * pt,struct net_device * orig_dev)618 int dn_route_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
619 {
620 	struct dn_skb_cb *cb;
621 	unsigned char flags = 0;
622 	__u16 len = le16_to_cpu(*(__le16 *)skb->data);
623 	struct dn_dev *dn = rcu_dereference(dev->dn_ptr);
624 	unsigned char padlen = 0;
625 
626 	if (!net_eq(dev_net(dev), &init_net))
627 		goto dump_it;
628 
629 	if (dn == NULL)
630 		goto dump_it;
631 
632 	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
633 		goto out;
634 
635 	if (!pskb_may_pull(skb, 3))
636 		goto dump_it;
637 
638 	skb_pull(skb, 2);
639 
640 	if (len > skb->len)
641 		goto dump_it;
642 
643 	skb_trim(skb, len);
644 
645 	flags = *skb->data;
646 
647 	cb = DN_SKB_CB(skb);
648 	cb->stamp = jiffies;
649 	cb->iif = dev->ifindex;
650 
651 	/*
652 	 * If we have padding, remove it.
653 	 */
654 	if (flags & DN_RT_F_PF) {
655 		padlen = flags & ~DN_RT_F_PF;
656 		if (!pskb_may_pull(skb, padlen + 1))
657 			goto dump_it;
658 		skb_pull(skb, padlen);
659 		flags = *skb->data;
660 	}
661 
662 	skb_reset_network_header(skb);
663 
664 	/*
665 	 * Weed out future version DECnet
666 	 */
667 	if (flags & DN_RT_F_VER)
668 		goto dump_it;
669 
670 	cb->rt_flags = flags;
671 
672 	if (decnet_debug_level & 1)
673 		printk(KERN_DEBUG
674 			"dn_route_rcv: got 0x%02x from %s [%d %d %d]\n",
675 			(int)flags, dev->name, len, skb->len,
676 			padlen);
677 
678 	if (flags & DN_RT_PKT_CNTL) {
679 		if (unlikely(skb_linearize(skb)))
680 			goto dump_it;
681 
682 		switch (flags & DN_RT_CNTL_MSK) {
683 		case DN_RT_PKT_INIT:
684 			dn_dev_init_pkt(skb);
685 			break;
686 		case DN_RT_PKT_VERI:
687 			dn_dev_veri_pkt(skb);
688 			break;
689 		}
690 
691 		if (dn->parms.state != DN_DEV_S_RU)
692 			goto dump_it;
693 
694 		switch (flags & DN_RT_CNTL_MSK) {
695 		case DN_RT_PKT_HELO:
696 			return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
697 				       &init_net, NULL, skb, skb->dev, NULL,
698 				       dn_route_ptp_hello);
699 
700 		case DN_RT_PKT_L1RT:
701 		case DN_RT_PKT_L2RT:
702 			return NF_HOOK(NFPROTO_DECNET, NF_DN_ROUTE,
703 				       &init_net, NULL, skb, skb->dev, NULL,
704 				       dn_route_discard);
705 		case DN_RT_PKT_ERTH:
706 			return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
707 				       &init_net, NULL, skb, skb->dev, NULL,
708 				       dn_neigh_router_hello);
709 
710 		case DN_RT_PKT_EEDH:
711 			return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
712 				       &init_net, NULL, skb, skb->dev, NULL,
713 				       dn_neigh_endnode_hello);
714 		}
715 	} else {
716 		if (dn->parms.state != DN_DEV_S_RU)
717 			goto dump_it;
718 
719 		skb_pull(skb, 1); /* Pull flags */
720 
721 		switch (flags & DN_RT_PKT_MSK) {
722 		case DN_RT_PKT_LONG:
723 			return dn_route_rx_long(skb);
724 		case DN_RT_PKT_SHORT:
725 			return dn_route_rx_short(skb);
726 		}
727 	}
728 
729 dump_it:
730 	kfree_skb(skb);
731 out:
732 	return NET_RX_DROP;
733 }
734 
dn_output(struct net * net,struct sock * sk,struct sk_buff * skb)735 static int dn_output(struct net *net, struct sock *sk, struct sk_buff *skb)
736 {
737 	struct dst_entry *dst = skb_dst(skb);
738 	struct dn_route *rt = (struct dn_route *)dst;
739 	struct net_device *dev = dst->dev;
740 	struct dn_skb_cb *cb = DN_SKB_CB(skb);
741 
742 	int err = -EINVAL;
743 
744 	if (rt->n == NULL)
745 		goto error;
746 
747 	skb->dev = dev;
748 
749 	cb->src = rt->rt_saddr;
750 	cb->dst = rt->rt_daddr;
751 
752 	/*
753 	 * Always set the Intra-Ethernet bit on all outgoing packets
754 	 * originated on this node. Only valid flag from upper layers
755 	 * is return-to-sender-requested. Set hop count to 0 too.
756 	 */
757 	cb->rt_flags &= ~DN_RT_F_RQR;
758 	cb->rt_flags |= DN_RT_F_IE;
759 	cb->hops = 0;
760 
761 	return NF_HOOK(NFPROTO_DECNET, NF_DN_LOCAL_OUT,
762 		       &init_net, sk, skb, NULL, dev,
763 		       dn_to_neigh_output);
764 
765 error:
766 	net_dbg_ratelimited("dn_output: This should not happen\n");
767 
768 	kfree_skb(skb);
769 
770 	return err;
771 }
772 
dn_forward(struct sk_buff * skb)773 static int dn_forward(struct sk_buff *skb)
774 {
775 	struct dn_skb_cb *cb = DN_SKB_CB(skb);
776 	struct dst_entry *dst = skb_dst(skb);
777 	struct dn_dev *dn_db = rcu_dereference(dst->dev->dn_ptr);
778 	struct dn_route *rt;
779 	int header_len;
780 	struct net_device *dev = skb->dev;
781 
782 	if (skb->pkt_type != PACKET_HOST)
783 		goto drop;
784 
785 	/* Ensure that we have enough space for headers */
786 	rt = (struct dn_route *)skb_dst(skb);
787 	header_len = dn_db->use_long ? 21 : 6;
788 	if (skb_cow(skb, LL_RESERVED_SPACE(rt->dst.dev)+header_len))
789 		goto drop;
790 
791 	/*
792 	 * Hop count exceeded.
793 	 */
794 	if (++cb->hops > 30)
795 		goto drop;
796 
797 	skb->dev = rt->dst.dev;
798 
799 	/*
800 	 * If packet goes out same interface it came in on, then set
801 	 * the Intra-Ethernet bit. This has no effect for short
802 	 * packets, so we don't need to test for them here.
803 	 */
804 	cb->rt_flags &= ~DN_RT_F_IE;
805 	if (rt->rt_flags & RTCF_DOREDIRECT)
806 		cb->rt_flags |= DN_RT_F_IE;
807 
808 	return NF_HOOK(NFPROTO_DECNET, NF_DN_FORWARD,
809 		       &init_net, NULL, skb, dev, skb->dev,
810 		       dn_to_neigh_output);
811 
812 drop:
813 	kfree_skb(skb);
814 	return NET_RX_DROP;
815 }
816 
817 /*
818  * Used to catch bugs. This should never normally get
819  * called.
820  */
dn_rt_bug_out(struct net * net,struct sock * sk,struct sk_buff * skb)821 static int dn_rt_bug_out(struct net *net, struct sock *sk, struct sk_buff *skb)
822 {
823 	struct dn_skb_cb *cb = DN_SKB_CB(skb);
824 
825 	net_dbg_ratelimited("dn_rt_bug: skb from:%04x to:%04x\n",
826 			    le16_to_cpu(cb->src), le16_to_cpu(cb->dst));
827 
828 	kfree_skb(skb);
829 
830 	return NET_RX_DROP;
831 }
832 
dn_rt_bug(struct sk_buff * skb)833 static int dn_rt_bug(struct sk_buff *skb)
834 {
835 	struct dn_skb_cb *cb = DN_SKB_CB(skb);
836 
837 	net_dbg_ratelimited("dn_rt_bug: skb from:%04x to:%04x\n",
838 			    le16_to_cpu(cb->src), le16_to_cpu(cb->dst));
839 
840 	kfree_skb(skb);
841 
842 	return NET_RX_DROP;
843 }
844 
dn_dst_default_advmss(const struct dst_entry * dst)845 static unsigned int dn_dst_default_advmss(const struct dst_entry *dst)
846 {
847 	return dn_mss_from_pmtu(dst->dev, dst_mtu(dst));
848 }
849 
dn_dst_mtu(const struct dst_entry * dst)850 static unsigned int dn_dst_mtu(const struct dst_entry *dst)
851 {
852 	unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
853 
854 	return mtu ? : dst->dev->mtu;
855 }
856 
dn_dst_neigh_lookup(const struct dst_entry * dst,struct sk_buff * skb,const void * daddr)857 static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst,
858 					     struct sk_buff *skb,
859 					     const void *daddr)
860 {
861 	return __neigh_lookup_errno(&dn_neigh_table, daddr, dst->dev);
862 }
863 
dn_rt_set_next_hop(struct dn_route * rt,struct dn_fib_res * res)864 static int dn_rt_set_next_hop(struct dn_route *rt, struct dn_fib_res *res)
865 {
866 	struct dn_fib_info *fi = res->fi;
867 	struct net_device *dev = rt->dst.dev;
868 	unsigned int mss_metric;
869 	struct neighbour *n;
870 
871 	if (fi) {
872 		if (DN_FIB_RES_GW(*res) &&
873 		    DN_FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
874 			rt->rt_gateway = DN_FIB_RES_GW(*res);
875 		dst_init_metrics(&rt->dst, fi->fib_metrics, true);
876 	}
877 	rt->rt_type = res->type;
878 
879 	if (dev != NULL && rt->n == NULL) {
880 		n = __neigh_lookup_errno(&dn_neigh_table, &rt->rt_gateway, dev);
881 		if (IS_ERR(n))
882 			return PTR_ERR(n);
883 		rt->n = n;
884 	}
885 
886 	if (dst_metric(&rt->dst, RTAX_MTU) > rt->dst.dev->mtu)
887 		dst_metric_set(&rt->dst, RTAX_MTU, rt->dst.dev->mtu);
888 	mss_metric = dst_metric_raw(&rt->dst, RTAX_ADVMSS);
889 	if (mss_metric) {
890 		unsigned int mss = dn_mss_from_pmtu(dev, dst_mtu(&rt->dst));
891 		if (mss_metric > mss)
892 			dst_metric_set(&rt->dst, RTAX_ADVMSS, mss);
893 	}
894 	return 0;
895 }
896 
dn_match_addr(__le16 addr1,__le16 addr2)897 static inline int dn_match_addr(__le16 addr1, __le16 addr2)
898 {
899 	__u16 tmp = le16_to_cpu(addr1) ^ le16_to_cpu(addr2);
900 	int match = 16;
901 	while(tmp) {
902 		tmp >>= 1;
903 		match--;
904 	}
905 	return match;
906 }
907 
dnet_select_source(const struct net_device * dev,__le16 daddr,int scope)908 static __le16 dnet_select_source(const struct net_device *dev, __le16 daddr, int scope)
909 {
910 	__le16 saddr = 0;
911 	struct dn_dev *dn_db;
912 	struct dn_ifaddr *ifa;
913 	int best_match = 0;
914 	int ret;
915 
916 	rcu_read_lock();
917 	dn_db = rcu_dereference(dev->dn_ptr);
918 	for (ifa = rcu_dereference(dn_db->ifa_list);
919 	     ifa != NULL;
920 	     ifa = rcu_dereference(ifa->ifa_next)) {
921 		if (ifa->ifa_scope > scope)
922 			continue;
923 		if (!daddr) {
924 			saddr = ifa->ifa_local;
925 			break;
926 		}
927 		ret = dn_match_addr(daddr, ifa->ifa_local);
928 		if (ret > best_match)
929 			saddr = ifa->ifa_local;
930 		if (best_match == 0)
931 			saddr = ifa->ifa_local;
932 	}
933 	rcu_read_unlock();
934 
935 	return saddr;
936 }
937 
__dn_fib_res_prefsrc(struct dn_fib_res * res)938 static inline __le16 __dn_fib_res_prefsrc(struct dn_fib_res *res)
939 {
940 	return dnet_select_source(DN_FIB_RES_DEV(*res), DN_FIB_RES_GW(*res), res->scope);
941 }
942 
dn_fib_rules_map_destination(__le16 daddr,struct dn_fib_res * res)943 static inline __le16 dn_fib_rules_map_destination(__le16 daddr, struct dn_fib_res *res)
944 {
945 	__le16 mask = dnet_make_mask(res->prefixlen);
946 	return (daddr&~mask)|res->fi->fib_nh->nh_gw;
947 }
948 
dn_route_output_slow(struct dst_entry ** pprt,const struct flowidn * oldflp,int try_hard)949 static int dn_route_output_slow(struct dst_entry **pprt, const struct flowidn *oldflp, int try_hard)
950 {
951 	struct flowidn fld = {
952 		.daddr = oldflp->daddr,
953 		.saddr = oldflp->saddr,
954 		.flowidn_scope = RT_SCOPE_UNIVERSE,
955 		.flowidn_mark = oldflp->flowidn_mark,
956 		.flowidn_iif = LOOPBACK_IFINDEX,
957 		.flowidn_oif = oldflp->flowidn_oif,
958 	};
959 	struct dn_route *rt = NULL;
960 	struct net_device *dev_out = NULL, *dev;
961 	struct neighbour *neigh = NULL;
962 	unsigned int hash;
963 	unsigned int flags = 0;
964 	struct dn_fib_res res = { .fi = NULL, .type = RTN_UNICAST };
965 	int err;
966 	int free_res = 0;
967 	__le16 gateway = 0;
968 
969 	if (decnet_debug_level & 16)
970 		printk(KERN_DEBUG
971 		       "dn_route_output_slow: dst=%04x src=%04x mark=%d"
972 		       " iif=%d oif=%d\n", le16_to_cpu(oldflp->daddr),
973 		       le16_to_cpu(oldflp->saddr),
974 		       oldflp->flowidn_mark, LOOPBACK_IFINDEX,
975 		       oldflp->flowidn_oif);
976 
977 	/* If we have an output interface, verify its a DECnet device */
978 	if (oldflp->flowidn_oif) {
979 		dev_out = dev_get_by_index(&init_net, oldflp->flowidn_oif);
980 		err = -ENODEV;
981 		if (dev_out && dev_out->dn_ptr == NULL) {
982 			dev_put(dev_out);
983 			dev_out = NULL;
984 		}
985 		if (dev_out == NULL)
986 			goto out;
987 	}
988 
989 	/* If we have a source address, verify that its a local address */
990 	if (oldflp->saddr) {
991 		err = -EADDRNOTAVAIL;
992 
993 		if (dev_out) {
994 			if (dn_dev_islocal(dev_out, oldflp->saddr))
995 				goto source_ok;
996 			dev_put(dev_out);
997 			goto out;
998 		}
999 		rcu_read_lock();
1000 		for_each_netdev_rcu(&init_net, dev) {
1001 			if (!dev->dn_ptr)
1002 				continue;
1003 			if (!dn_dev_islocal(dev, oldflp->saddr))
1004 				continue;
1005 			if ((dev->flags & IFF_LOOPBACK) &&
1006 			    oldflp->daddr &&
1007 			    !dn_dev_islocal(dev, oldflp->daddr))
1008 				continue;
1009 
1010 			dev_out = dev;
1011 			break;
1012 		}
1013 		rcu_read_unlock();
1014 		if (dev_out == NULL)
1015 			goto out;
1016 		dev_hold(dev_out);
1017 source_ok:
1018 		;
1019 	}
1020 
1021 	/* No destination? Assume its local */
1022 	if (!fld.daddr) {
1023 		fld.daddr = fld.saddr;
1024 
1025 		if (dev_out)
1026 			dev_put(dev_out);
1027 		err = -EINVAL;
1028 		dev_out = init_net.loopback_dev;
1029 		if (!dev_out->dn_ptr)
1030 			goto out;
1031 		err = -EADDRNOTAVAIL;
1032 		dev_hold(dev_out);
1033 		if (!fld.daddr) {
1034 			fld.daddr =
1035 			fld.saddr = dnet_select_source(dev_out, 0,
1036 						       RT_SCOPE_HOST);
1037 			if (!fld.daddr)
1038 				goto out;
1039 		}
1040 		fld.flowidn_oif = LOOPBACK_IFINDEX;
1041 		res.type = RTN_LOCAL;
1042 		goto make_route;
1043 	}
1044 
1045 	if (decnet_debug_level & 16)
1046 		printk(KERN_DEBUG
1047 		       "dn_route_output_slow: initial checks complete."
1048 		       " dst=%04x src=%04x oif=%d try_hard=%d\n",
1049 		       le16_to_cpu(fld.daddr), le16_to_cpu(fld.saddr),
1050 		       fld.flowidn_oif, try_hard);
1051 
1052 	/*
1053 	 * N.B. If the kernel is compiled without router support then
1054 	 * dn_fib_lookup() will evaluate to non-zero so this if () block
1055 	 * will always be executed.
1056 	 */
1057 	err = -ESRCH;
1058 	if (try_hard || (err = dn_fib_lookup(&fld, &res)) != 0) {
1059 		struct dn_dev *dn_db;
1060 		if (err != -ESRCH)
1061 			goto out;
1062 		/*
1063 		 * Here the fallback is basically the standard algorithm for
1064 		 * routing in endnodes which is described in the DECnet routing
1065 		 * docs
1066 		 *
1067 		 * If we are not trying hard, look in neighbour cache.
1068 		 * The result is tested to ensure that if a specific output
1069 		 * device/source address was requested, then we honour that
1070 		 * here
1071 		 */
1072 		if (!try_hard) {
1073 			neigh = neigh_lookup_nodev(&dn_neigh_table, &init_net, &fld.daddr);
1074 			if (neigh) {
1075 				if ((oldflp->flowidn_oif &&
1076 				    (neigh->dev->ifindex != oldflp->flowidn_oif)) ||
1077 				    (oldflp->saddr &&
1078 				    (!dn_dev_islocal(neigh->dev,
1079 						     oldflp->saddr)))) {
1080 					neigh_release(neigh);
1081 					neigh = NULL;
1082 				} else {
1083 					if (dev_out)
1084 						dev_put(dev_out);
1085 					if (dn_dev_islocal(neigh->dev, fld.daddr)) {
1086 						dev_out = init_net.loopback_dev;
1087 						res.type = RTN_LOCAL;
1088 					} else {
1089 						dev_out = neigh->dev;
1090 					}
1091 					dev_hold(dev_out);
1092 					goto select_source;
1093 				}
1094 			}
1095 		}
1096 
1097 		/* Not there? Perhaps its a local address */
1098 		if (dev_out == NULL)
1099 			dev_out = dn_dev_get_default();
1100 		err = -ENODEV;
1101 		if (dev_out == NULL)
1102 			goto out;
1103 		dn_db = rcu_dereference_raw(dev_out->dn_ptr);
1104 		if (!dn_db)
1105 			goto e_inval;
1106 		/* Possible improvement - check all devices for local addr */
1107 		if (dn_dev_islocal(dev_out, fld.daddr)) {
1108 			dev_put(dev_out);
1109 			dev_out = init_net.loopback_dev;
1110 			dev_hold(dev_out);
1111 			res.type = RTN_LOCAL;
1112 			goto select_source;
1113 		}
1114 		/* Not local either.... try sending it to the default router */
1115 		neigh = neigh_clone(dn_db->router);
1116 		BUG_ON(neigh && neigh->dev != dev_out);
1117 
1118 		/* Ok then, we assume its directly connected and move on */
1119 select_source:
1120 		if (neigh)
1121 			gateway = ((struct dn_neigh *)neigh)->addr;
1122 		if (gateway == 0)
1123 			gateway = fld.daddr;
1124 		if (fld.saddr == 0) {
1125 			fld.saddr = dnet_select_source(dev_out, gateway,
1126 						       res.type == RTN_LOCAL ?
1127 						       RT_SCOPE_HOST :
1128 						       RT_SCOPE_LINK);
1129 			if (fld.saddr == 0 && res.type != RTN_LOCAL)
1130 				goto e_addr;
1131 		}
1132 		fld.flowidn_oif = dev_out->ifindex;
1133 		goto make_route;
1134 	}
1135 	free_res = 1;
1136 
1137 	if (res.type == RTN_NAT)
1138 		goto e_inval;
1139 
1140 	if (res.type == RTN_LOCAL) {
1141 		if (!fld.saddr)
1142 			fld.saddr = fld.daddr;
1143 		if (dev_out)
1144 			dev_put(dev_out);
1145 		dev_out = init_net.loopback_dev;
1146 		dev_hold(dev_out);
1147 		if (!dev_out->dn_ptr)
1148 			goto e_inval;
1149 		fld.flowidn_oif = dev_out->ifindex;
1150 		if (res.fi)
1151 			dn_fib_info_put(res.fi);
1152 		res.fi = NULL;
1153 		goto make_route;
1154 	}
1155 
1156 	if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1157 		dn_fib_select_multipath(&fld, &res);
1158 
1159 	/*
1160 	 * We could add some logic to deal with default routes here and
1161 	 * get rid of some of the special casing above.
1162 	 */
1163 
1164 	if (!fld.saddr)
1165 		fld.saddr = DN_FIB_RES_PREFSRC(res);
1166 
1167 	if (dev_out)
1168 		dev_put(dev_out);
1169 	dev_out = DN_FIB_RES_DEV(res);
1170 	dev_hold(dev_out);
1171 	fld.flowidn_oif = dev_out->ifindex;
1172 	gateway = DN_FIB_RES_GW(res);
1173 
1174 make_route:
1175 	if (dev_out->flags & IFF_LOOPBACK)
1176 		flags |= RTCF_LOCAL;
1177 
1178 	rt = dst_alloc(&dn_dst_ops, dev_out, 0, DST_OBSOLETE_NONE, 0);
1179 	if (rt == NULL)
1180 		goto e_nobufs;
1181 
1182 	rt->dn_next = NULL;
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() increments dst->__refcnt */
1214 	dn_insert_route(rt, hash, (struct dn_route **)pprt);
1215 
1216 done:
1217 	if (neigh)
1218 		neigh_release(neigh);
1219 	if (free_res)
1220 		dn_fib_res_put(&res);
1221 	if (dev_out)
1222 		dev_put(dev_out);
1223 out:
1224 	return err;
1225 
1226 e_addr:
1227 	err = -EADDRNOTAVAIL;
1228 	goto done;
1229 e_inval:
1230 	err = -EINVAL;
1231 	goto done;
1232 e_nobufs:
1233 	err = -ENOBUFS;
1234 	goto done;
1235 e_neighbour:
1236 	dst_release_immediate(&rt->dst);
1237 	goto e_nobufs;
1238 }
1239 
1240 
1241 /*
1242  * N.B. The flags may be moved into the flowi at some future stage.
1243  */
__dn_route_output_key(struct dst_entry ** pprt,const struct flowidn * flp,int flags)1244 static int __dn_route_output_key(struct dst_entry **pprt, const struct flowidn *flp, int flags)
1245 {
1246 	unsigned int hash = dn_hash(flp->saddr, flp->daddr);
1247 	struct dn_route *rt = NULL;
1248 
1249 	if (!(flags & MSG_TRYHARD)) {
1250 		rcu_read_lock_bh();
1251 		for (rt = rcu_dereference_bh(dn_rt_hash_table[hash].chain); rt;
1252 			rt = rcu_dereference_bh(rt->dn_next)) {
1253 			if ((flp->daddr == rt->fld.daddr) &&
1254 			    (flp->saddr == rt->fld.saddr) &&
1255 			    (flp->flowidn_mark == rt->fld.flowidn_mark) &&
1256 			    dn_is_output_route(rt) &&
1257 			    (rt->fld.flowidn_oif == flp->flowidn_oif)) {
1258 				dst_hold_and_use(&rt->dst, jiffies);
1259 				rcu_read_unlock_bh();
1260 				*pprt = &rt->dst;
1261 				return 0;
1262 			}
1263 		}
1264 		rcu_read_unlock_bh();
1265 	}
1266 
1267 	return dn_route_output_slow(pprt, flp, flags);
1268 }
1269 
dn_route_output_key(struct dst_entry ** pprt,struct flowidn * flp,int flags)1270 static int dn_route_output_key(struct dst_entry **pprt, struct flowidn *flp, int flags)
1271 {
1272 	int err;
1273 
1274 	err = __dn_route_output_key(pprt, flp, flags);
1275 	if (err == 0 && flp->flowidn_proto) {
1276 		*pprt = xfrm_lookup(&init_net, *pprt,
1277 				    flowidn_to_flowi(flp), NULL, 0);
1278 		if (IS_ERR(*pprt)) {
1279 			err = PTR_ERR(*pprt);
1280 			*pprt = NULL;
1281 		}
1282 	}
1283 	return err;
1284 }
1285 
dn_route_output_sock(struct dst_entry __rcu ** pprt,struct flowidn * fl,struct sock * sk,int flags)1286 int dn_route_output_sock(struct dst_entry __rcu **pprt, struct flowidn *fl, struct sock *sk, int flags)
1287 {
1288 	int err;
1289 
1290 	err = __dn_route_output_key(pprt, fl, flags & MSG_TRYHARD);
1291 	if (err == 0 && fl->flowidn_proto) {
1292 		*pprt = xfrm_lookup(&init_net, *pprt,
1293 				    flowidn_to_flowi(fl), sk, 0);
1294 		if (IS_ERR(*pprt)) {
1295 			err = PTR_ERR(*pprt);
1296 			*pprt = NULL;
1297 		}
1298 	}
1299 	return err;
1300 }
1301 
dn_route_input_slow(struct sk_buff * skb)1302 static int dn_route_input_slow(struct sk_buff *skb)
1303 {
1304 	struct dn_route *rt = NULL;
1305 	struct dn_skb_cb *cb = DN_SKB_CB(skb);
1306 	struct net_device *in_dev = skb->dev;
1307 	struct net_device *out_dev = NULL;
1308 	struct dn_dev *dn_db;
1309 	struct neighbour *neigh = NULL;
1310 	unsigned int hash;
1311 	int flags = 0;
1312 	__le16 gateway = 0;
1313 	__le16 local_src = 0;
1314 	struct flowidn fld = {
1315 		.daddr = cb->dst,
1316 		.saddr = cb->src,
1317 		.flowidn_scope = RT_SCOPE_UNIVERSE,
1318 		.flowidn_mark = skb->mark,
1319 		.flowidn_iif = skb->dev->ifindex,
1320 	};
1321 	struct dn_fib_res res = { .fi = NULL, .type = RTN_UNREACHABLE };
1322 	int err = -EINVAL;
1323 	int free_res = 0;
1324 
1325 	dev_hold(in_dev);
1326 
1327 	if ((dn_db = rcu_dereference(in_dev->dn_ptr)) == NULL)
1328 		goto out;
1329 
1330 	/* Zero source addresses are not allowed */
1331 	if (fld.saddr == 0)
1332 		goto out;
1333 
1334 	/*
1335 	 * In this case we've just received a packet from a source
1336 	 * outside ourselves pretending to come from us. We don't
1337 	 * allow it any further to prevent routing loops, spoofing and
1338 	 * other nasties. Loopback packets already have the dst attached
1339 	 * so this only affects packets which have originated elsewhere.
1340 	 */
1341 	err  = -ENOTUNIQ;
1342 	if (dn_dev_islocal(in_dev, cb->src))
1343 		goto out;
1344 
1345 	err = dn_fib_lookup(&fld, &res);
1346 	if (err) {
1347 		if (err != -ESRCH)
1348 			goto out;
1349 		/*
1350 		 * Is the destination us ?
1351 		 */
1352 		if (!dn_dev_islocal(in_dev, cb->dst))
1353 			goto e_inval;
1354 
1355 		res.type = RTN_LOCAL;
1356 	} else {
1357 		__le16 src_map = fld.saddr;
1358 		free_res = 1;
1359 
1360 		out_dev = DN_FIB_RES_DEV(res);
1361 		if (out_dev == NULL) {
1362 			net_crit_ratelimited("Bug in dn_route_input_slow() No output device\n");
1363 			goto e_inval;
1364 		}
1365 		dev_hold(out_dev);
1366 
1367 		if (res.r)
1368 			src_map = fld.saddr; /* no NAT support for now */
1369 
1370 		gateway = DN_FIB_RES_GW(res);
1371 		if (res.type == RTN_NAT) {
1372 			fld.daddr = dn_fib_rules_map_destination(fld.daddr, &res);
1373 			dn_fib_res_put(&res);
1374 			free_res = 0;
1375 			if (dn_fib_lookup(&fld, &res))
1376 				goto e_inval;
1377 			free_res = 1;
1378 			if (res.type != RTN_UNICAST)
1379 				goto e_inval;
1380 			flags |= RTCF_DNAT;
1381 			gateway = fld.daddr;
1382 		}
1383 		fld.saddr = src_map;
1384 	}
1385 
1386 	switch(res.type) {
1387 	case RTN_UNICAST:
1388 		/*
1389 		 * Forwarding check here, we only check for forwarding
1390 		 * being turned off, if you want to only forward intra
1391 		 * area, its up to you to set the routing tables up
1392 		 * correctly.
1393 		 */
1394 		if (dn_db->parms.forwarding == 0)
1395 			goto e_inval;
1396 
1397 		if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1398 			dn_fib_select_multipath(&fld, &res);
1399 
1400 		/*
1401 		 * Check for out_dev == in_dev. We use the RTCF_DOREDIRECT
1402 		 * flag as a hint to set the intra-ethernet bit when
1403 		 * forwarding. If we've got NAT in operation, we don't do
1404 		 * this optimisation.
1405 		 */
1406 		if (out_dev == in_dev && !(flags & RTCF_NAT))
1407 			flags |= RTCF_DOREDIRECT;
1408 
1409 		local_src = DN_FIB_RES_PREFSRC(res);
1410 
1411 	case RTN_BLACKHOLE:
1412 	case RTN_UNREACHABLE:
1413 		break;
1414 	case RTN_LOCAL:
1415 		flags |= RTCF_LOCAL;
1416 		fld.saddr = cb->dst;
1417 		fld.daddr = cb->src;
1418 
1419 		/* Routing tables gave us a gateway */
1420 		if (gateway)
1421 			goto make_route;
1422 
1423 		/* Packet was intra-ethernet, so we know its on-link */
1424 		if (cb->rt_flags & DN_RT_F_IE) {
1425 			gateway = cb->src;
1426 			goto make_route;
1427 		}
1428 
1429 		/* Use the default router if there is one */
1430 		neigh = neigh_clone(dn_db->router);
1431 		if (neigh) {
1432 			gateway = ((struct dn_neigh *)neigh)->addr;
1433 			goto make_route;
1434 		}
1435 
1436 		/* Close eyes and pray */
1437 		gateway = cb->src;
1438 		goto make_route;
1439 	default:
1440 		goto e_inval;
1441 	}
1442 
1443 make_route:
1444 	rt = dst_alloc(&dn_dst_ops, out_dev, 1, DST_OBSOLETE_NONE, 0);
1445 	if (rt == NULL)
1446 		goto e_nobufs;
1447 
1448 	rt->dn_next = NULL;
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_out;
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() increments dst->__refcnt */
1492 	dn_insert_route(rt, hash, &rt);
1493 	skb_dst_set(skb, &rt->dst);
1494 
1495 done:
1496 	if (neigh)
1497 		neigh_release(neigh);
1498 	if (free_res)
1499 		dn_fib_res_put(&res);
1500 	dev_put(in_dev);
1501 	if (out_dev)
1502 		dev_put(out_dev);
1503 out:
1504 	return err;
1505 
1506 e_inval:
1507 	err = -EINVAL;
1508 	goto done;
1509 
1510 e_nobufs:
1511 	err = -ENOBUFS;
1512 	goto done;
1513 
1514 e_neighbour:
1515 	dst_release_immediate(&rt->dst);
1516 	goto done;
1517 }
1518 
dn_route_input(struct sk_buff * skb)1519 static int dn_route_input(struct sk_buff *skb)
1520 {
1521 	struct dn_route *rt;
1522 	struct dn_skb_cb *cb = DN_SKB_CB(skb);
1523 	unsigned int hash = dn_hash(cb->src, cb->dst);
1524 
1525 	if (skb_dst(skb))
1526 		return 0;
1527 
1528 	rcu_read_lock();
1529 	for(rt = rcu_dereference(dn_rt_hash_table[hash].chain); rt != NULL;
1530 	    rt = rcu_dereference(rt->dn_next)) {
1531 		if ((rt->fld.saddr == cb->src) &&
1532 		    (rt->fld.daddr == cb->dst) &&
1533 		    (rt->fld.flowidn_oif == 0) &&
1534 		    (rt->fld.flowidn_mark == skb->mark) &&
1535 		    (rt->fld.flowidn_iif == cb->iif)) {
1536 			dst_hold_and_use(&rt->dst, jiffies);
1537 			rcu_read_unlock();
1538 			skb_dst_set(skb, (struct dst_entry *)rt);
1539 			return 0;
1540 		}
1541 	}
1542 	rcu_read_unlock();
1543 
1544 	return dn_route_input_slow(skb);
1545 }
1546 
dn_rt_fill_info(struct sk_buff * skb,u32 portid,u32 seq,int event,int nowait,unsigned int flags)1547 static int dn_rt_fill_info(struct sk_buff *skb, u32 portid, u32 seq,
1548 			   int event, int nowait, unsigned int flags)
1549 {
1550 	struct dn_route *rt = (struct dn_route *)skb_dst(skb);
1551 	struct rtmsg *r;
1552 	struct nlmsghdr *nlh;
1553 	long expires;
1554 
1555 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
1556 	if (!nlh)
1557 		return -EMSGSIZE;
1558 
1559 	r = nlmsg_data(nlh);
1560 	r->rtm_family = AF_DECnet;
1561 	r->rtm_dst_len = 16;
1562 	r->rtm_src_len = 0;
1563 	r->rtm_tos = 0;
1564 	r->rtm_table = RT_TABLE_MAIN;
1565 	r->rtm_type = rt->rt_type;
1566 	r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
1567 	r->rtm_scope = RT_SCOPE_UNIVERSE;
1568 	r->rtm_protocol = RTPROT_UNSPEC;
1569 
1570 	if (rt->rt_flags & RTCF_NOTIFY)
1571 		r->rtm_flags |= RTM_F_NOTIFY;
1572 
1573 	if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN) < 0 ||
1574 	    nla_put_le16(skb, RTA_DST, rt->rt_daddr) < 0)
1575 		goto errout;
1576 
1577 	if (rt->fld.saddr) {
1578 		r->rtm_src_len = 16;
1579 		if (nla_put_le16(skb, RTA_SRC, rt->fld.saddr) < 0)
1580 			goto errout;
1581 	}
1582 	if (rt->dst.dev &&
1583 	    nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex) < 0)
1584 		goto errout;
1585 
1586 	/*
1587 	 * Note to self - change this if input routes reverse direction when
1588 	 * they deal only with inputs and not with replies like they do
1589 	 * currently.
1590 	 */
1591 	if (nla_put_le16(skb, RTA_PREFSRC, rt->rt_local_src) < 0)
1592 		goto errout;
1593 
1594 	if (rt->rt_daddr != rt->rt_gateway &&
1595 	    nla_put_le16(skb, RTA_GATEWAY, rt->rt_gateway) < 0)
1596 		goto errout;
1597 
1598 	if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
1599 		goto errout;
1600 
1601 	expires = rt->dst.expires ? rt->dst.expires - jiffies : 0;
1602 	if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires,
1603 			       rt->dst.error) < 0)
1604 		goto errout;
1605 
1606 	if (dn_is_input_route(rt) &&
1607 	    nla_put_u32(skb, RTA_IIF, rt->fld.flowidn_iif) < 0)
1608 		goto errout;
1609 
1610 	nlmsg_end(skb, nlh);
1611 	return 0;
1612 
1613 errout:
1614 	nlmsg_cancel(skb, nlh);
1615 	return -EMSGSIZE;
1616 }
1617 
1618 const struct nla_policy rtm_dn_policy[RTA_MAX + 1] = {
1619 	[RTA_DST]		= { .type = NLA_U16 },
1620 	[RTA_SRC]		= { .type = NLA_U16 },
1621 	[RTA_IIF]		= { .type = NLA_U32 },
1622 	[RTA_OIF]		= { .type = NLA_U32 },
1623 	[RTA_GATEWAY]		= { .type = NLA_U16 },
1624 	[RTA_PRIORITY]		= { .type = NLA_U32 },
1625 	[RTA_PREFSRC]		= { .type = NLA_U16 },
1626 	[RTA_METRICS]		= { .type = NLA_NESTED },
1627 	[RTA_MULTIPATH]		= { .type = NLA_NESTED },
1628 	[RTA_TABLE]		= { .type = NLA_U32 },
1629 	[RTA_MARK]		= { .type = NLA_U32 },
1630 };
1631 
1632 /*
1633  * This is called by both endnodes and routers now.
1634  */
dn_cache_getroute(struct sk_buff * in_skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)1635 static int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
1636 			     struct netlink_ext_ack *extack)
1637 {
1638 	struct net *net = sock_net(in_skb->sk);
1639 	struct rtmsg *rtm = nlmsg_data(nlh);
1640 	struct dn_route *rt = NULL;
1641 	struct dn_skb_cb *cb;
1642 	int err;
1643 	struct sk_buff *skb;
1644 	struct flowidn fld;
1645 	struct nlattr *tb[RTA_MAX+1];
1646 
1647 	if (!net_eq(net, &init_net))
1648 		return -EINVAL;
1649 
1650 	err = nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
1651 				     rtm_dn_policy, extack);
1652 	if (err < 0)
1653 		return err;
1654 
1655 	memset(&fld, 0, sizeof(fld));
1656 	fld.flowidn_proto = DNPROTO_NSP;
1657 
1658 	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1659 	if (skb == NULL)
1660 		return -ENOBUFS;
1661 	skb_reset_mac_header(skb);
1662 	cb = DN_SKB_CB(skb);
1663 
1664 	if (tb[RTA_SRC])
1665 		fld.saddr = nla_get_le16(tb[RTA_SRC]);
1666 
1667 	if (tb[RTA_DST])
1668 		fld.daddr = nla_get_le16(tb[RTA_DST]);
1669 
1670 	if (tb[RTA_IIF])
1671 		fld.flowidn_iif = nla_get_u32(tb[RTA_IIF]);
1672 
1673 	if (fld.flowidn_iif) {
1674 		struct net_device *dev;
1675 		dev = __dev_get_by_index(&init_net, fld.flowidn_iif);
1676 		if (!dev || !dev->dn_ptr) {
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 	skb->dev = NULL;
1699 	if (err)
1700 		goto out_free;
1701 	skb_dst_set(skb, &rt->dst);
1702 	if (rtm->rtm_flags & RTM_F_NOTIFY)
1703 		rt->rt_flags |= RTCF_NOTIFY;
1704 
1705 	err = dn_rt_fill_info(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, RTM_NEWROUTE, 0, 0);
1706 	if (err < 0) {
1707 		err = -EMSGSIZE;
1708 		goto out_free;
1709 	}
1710 
1711 	return rtnl_unicast(skb, &init_net, NETLINK_CB(in_skb).portid);
1712 
1713 out_free:
1714 	kfree_skb(skb);
1715 	return err;
1716 }
1717 
1718 /*
1719  * For routers, this is called from dn_fib_dump, but for endnodes its
1720  * called directly from the rtnetlink dispatch table.
1721  */
dn_cache_dump(struct sk_buff * skb,struct netlink_callback * cb)1722 int dn_cache_dump(struct sk_buff *skb, struct netlink_callback *cb)
1723 {
1724 	struct net *net = sock_net(skb->sk);
1725 	struct dn_route *rt;
1726 	int h, s_h;
1727 	int idx, s_idx;
1728 	struct rtmsg *rtm;
1729 
1730 	if (!net_eq(net, &init_net))
1731 		return 0;
1732 
1733 	if (nlmsg_len(cb->nlh) < sizeof(struct rtmsg))
1734 		return -EINVAL;
1735 
1736 	rtm = nlmsg_data(cb->nlh);
1737 	if (!(rtm->rtm_flags & RTM_F_CLONED))
1738 		return 0;
1739 
1740 	s_h = cb->args[0];
1741 	s_idx = idx = cb->args[1];
1742 	for(h = 0; h <= dn_rt_hash_mask; h++) {
1743 		if (h < s_h)
1744 			continue;
1745 		if (h > s_h)
1746 			s_idx = 0;
1747 		rcu_read_lock_bh();
1748 		for(rt = rcu_dereference_bh(dn_rt_hash_table[h].chain), idx = 0;
1749 			rt;
1750 			rt = rcu_dereference_bh(rt->dn_next), idx++) {
1751 			if (idx < s_idx)
1752 				continue;
1753 			skb_dst_set(skb, dst_clone(&rt->dst));
1754 			if (dn_rt_fill_info(skb, NETLINK_CB(cb->skb).portid,
1755 					cb->nlh->nlmsg_seq, RTM_NEWROUTE,
1756 					1, NLM_F_MULTI) < 0) {
1757 				skb_dst_drop(skb);
1758 				rcu_read_unlock_bh();
1759 				goto done;
1760 			}
1761 			skb_dst_drop(skb);
1762 		}
1763 		rcu_read_unlock_bh();
1764 	}
1765 
1766 done:
1767 	cb->args[0] = h;
1768 	cb->args[1] = idx;
1769 	return skb->len;
1770 }
1771 
1772 #ifdef CONFIG_PROC_FS
1773 struct dn_rt_cache_iter_state {
1774 	int bucket;
1775 };
1776 
dn_rt_cache_get_first(struct seq_file * seq)1777 static struct dn_route *dn_rt_cache_get_first(struct seq_file *seq)
1778 {
1779 	struct dn_route *rt = NULL;
1780 	struct dn_rt_cache_iter_state *s = seq->private;
1781 
1782 	for(s->bucket = dn_rt_hash_mask; s->bucket >= 0; --s->bucket) {
1783 		rcu_read_lock_bh();
1784 		rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1785 		if (rt)
1786 			break;
1787 		rcu_read_unlock_bh();
1788 	}
1789 	return rt;
1790 }
1791 
dn_rt_cache_get_next(struct seq_file * seq,struct dn_route * rt)1792 static struct dn_route *dn_rt_cache_get_next(struct seq_file *seq, struct dn_route *rt)
1793 {
1794 	struct dn_rt_cache_iter_state *s = seq->private;
1795 
1796 	rt = rcu_dereference_bh(rt->dn_next);
1797 	while (!rt) {
1798 		rcu_read_unlock_bh();
1799 		if (--s->bucket < 0)
1800 			break;
1801 		rcu_read_lock_bh();
1802 		rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1803 	}
1804 	return rt;
1805 }
1806 
dn_rt_cache_seq_start(struct seq_file * seq,loff_t * pos)1807 static void *dn_rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
1808 {
1809 	struct dn_route *rt = dn_rt_cache_get_first(seq);
1810 
1811 	if (rt) {
1812 		while(*pos && (rt = dn_rt_cache_get_next(seq, rt)))
1813 			--*pos;
1814 	}
1815 	return *pos ? NULL : rt;
1816 }
1817 
dn_rt_cache_seq_next(struct seq_file * seq,void * v,loff_t * pos)1818 static void *dn_rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1819 {
1820 	struct dn_route *rt = dn_rt_cache_get_next(seq, v);
1821 	++*pos;
1822 	return rt;
1823 }
1824 
dn_rt_cache_seq_stop(struct seq_file * seq,void * v)1825 static void dn_rt_cache_seq_stop(struct seq_file *seq, void *v)
1826 {
1827 	if (v)
1828 		rcu_read_unlock_bh();
1829 }
1830 
dn_rt_cache_seq_show(struct seq_file * seq,void * v)1831 static int dn_rt_cache_seq_show(struct seq_file *seq, void *v)
1832 {
1833 	struct dn_route *rt = v;
1834 	char buf1[DN_ASCBUF_LEN], buf2[DN_ASCBUF_LEN];
1835 
1836 	seq_printf(seq, "%-8s %-7s %-7s %04d %04d %04d\n",
1837 		   rt->dst.dev ? rt->dst.dev->name : "*",
1838 		   dn_addr2asc(le16_to_cpu(rt->rt_daddr), buf1),
1839 		   dn_addr2asc(le16_to_cpu(rt->rt_saddr), buf2),
1840 		   atomic_read(&rt->dst.__refcnt),
1841 		   rt->dst.__use, 0);
1842 	return 0;
1843 }
1844 
1845 static const struct seq_operations dn_rt_cache_seq_ops = {
1846 	.start	= dn_rt_cache_seq_start,
1847 	.next	= dn_rt_cache_seq_next,
1848 	.stop	= dn_rt_cache_seq_stop,
1849 	.show	= dn_rt_cache_seq_show,
1850 };
1851 #endif /* CONFIG_PROC_FS */
1852 
dn_route_init(void)1853 void __init dn_route_init(void)
1854 {
1855 	int i, goal, order;
1856 
1857 	dn_dst_ops.kmem_cachep =
1858 		kmem_cache_create("dn_dst_cache", sizeof(struct dn_route), 0,
1859 				  SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
1860 	dst_entries_init(&dn_dst_ops);
1861 	timer_setup(&dn_route_timer, dn_dst_check_expire, 0);
1862 	dn_route_timer.expires = jiffies + decnet_dst_gc_interval * HZ;
1863 	add_timer(&dn_route_timer);
1864 
1865 	goal = totalram_pages() >> (26 - PAGE_SHIFT);
1866 
1867 	for(order = 0; (1UL << order) < goal; order++)
1868 		/* NOTHING */;
1869 
1870 	/*
1871 	 * Only want 1024 entries max, since the table is very, very unlikely
1872 	 * to be larger than that.
1873 	 */
1874 	while(order && ((((1UL << order) * PAGE_SIZE) /
1875 				sizeof(struct dn_rt_hash_bucket)) >= 2048))
1876 		order--;
1877 
1878 	do {
1879 		dn_rt_hash_mask = (1UL << order) * PAGE_SIZE /
1880 			sizeof(struct dn_rt_hash_bucket);
1881 		while(dn_rt_hash_mask & (dn_rt_hash_mask - 1))
1882 			dn_rt_hash_mask--;
1883 		dn_rt_hash_table = (struct dn_rt_hash_bucket *)
1884 			__get_free_pages(GFP_ATOMIC, order);
1885 	} while (dn_rt_hash_table == NULL && --order > 0);
1886 
1887 	if (!dn_rt_hash_table)
1888 		panic("Failed to allocate DECnet route cache hash table\n");
1889 
1890 	printk(KERN_INFO
1891 		"DECnet: Routing cache hash table of %u buckets, %ldKbytes\n",
1892 		dn_rt_hash_mask,
1893 		(long)(dn_rt_hash_mask*sizeof(struct dn_rt_hash_bucket))/1024);
1894 
1895 	dn_rt_hash_mask--;
1896 	for(i = 0; i <= dn_rt_hash_mask; i++) {
1897 		spin_lock_init(&dn_rt_hash_table[i].lock);
1898 		dn_rt_hash_table[i].chain = NULL;
1899 	}
1900 
1901 	dn_dst_ops.gc_thresh = (dn_rt_hash_mask + 1);
1902 
1903 	proc_create_seq_private("decnet_cache", 0444, init_net.proc_net,
1904 			&dn_rt_cache_seq_ops,
1905 			sizeof(struct dn_rt_cache_iter_state), NULL);
1906 
1907 #ifdef CONFIG_DECNET_ROUTER
1908 	rtnl_register_module(THIS_MODULE, PF_DECnet, RTM_GETROUTE,
1909 			     dn_cache_getroute, dn_fib_dump, 0);
1910 #else
1911 	rtnl_register_module(THIS_MODULE, PF_DECnet, RTM_GETROUTE,
1912 			     dn_cache_getroute, dn_cache_dump, 0);
1913 #endif
1914 }
1915 
dn_route_cleanup(void)1916 void __exit dn_route_cleanup(void)
1917 {
1918 	del_timer(&dn_route_timer);
1919 	dn_run_flush(NULL);
1920 
1921 	remove_proc_entry("decnet_cache", init_net.proc_net);
1922 	dst_entries_destroy(&dn_dst_ops);
1923 }
1924