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v5.4
  1// SPDX-License-Identifier: GPL-2.0
  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 Neighbour Functions (Adjacency Database and
  8 *                                                        On-Ethernet Cache)
  9 *
 10 * Author:      Steve Whitehouse <SteveW@ACM.org>
 11 *
 12 *
 13 * Changes:
 14 *     Steve Whitehouse     : Fixed router listing routine
 15 *     Steve Whitehouse     : Added error_report functions
 16 *     Steve Whitehouse     : Added default router detection
 17 *     Steve Whitehouse     : Hop counts in outgoing messages
 18 *     Steve Whitehouse     : Fixed src/dst in outgoing messages so
 19 *                            forwarding now stands a good chance of
 20 *                            working.
 21 *     Steve Whitehouse     : Fixed neighbour states (for now anyway).
 22 *     Steve Whitehouse     : Made error_report functions dummies. This
 23 *                            is not the right place to return skbs.
 24 *     Steve Whitehouse     : Convert to seq_file
 25 *
 26 */
 27
 28#include <linux/net.h>
 29#include <linux/module.h>
 30#include <linux/socket.h>
 31#include <linux/if_arp.h>
 32#include <linux/slab.h>
 33#include <linux/if_ether.h>
 34#include <linux/init.h>
 35#include <linux/proc_fs.h>
 36#include <linux/string.h>
 37#include <linux/netfilter_decnet.h>
 38#include <linux/spinlock.h>
 39#include <linux/seq_file.h>
 40#include <linux/rcupdate.h>
 41#include <linux/jhash.h>
 42#include <linux/atomic.h>
 43#include <net/net_namespace.h>
 44#include <net/neighbour.h>
 45#include <net/dst.h>
 46#include <net/flow.h>
 47#include <net/dn.h>
 48#include <net/dn_dev.h>
 49#include <net/dn_neigh.h>
 50#include <net/dn_route.h>
 51
 52static int dn_neigh_construct(struct neighbour *);
 53static void dn_neigh_error_report(struct neighbour *, struct sk_buff *);
 54static int dn_neigh_output(struct neighbour *neigh, struct sk_buff *skb);
 55
 56/*
 57 * Operations for adding the link layer header.
 58 */
 59static const struct neigh_ops dn_neigh_ops = {
 60	.family =		AF_DECnet,
 61	.error_report =		dn_neigh_error_report,
 62	.output =		dn_neigh_output,
 63	.connected_output =	dn_neigh_output,
 64};
 65
 66static u32 dn_neigh_hash(const void *pkey,
 67			 const struct net_device *dev,
 68			 __u32 *hash_rnd)
 69{
 70	return jhash_2words(*(__u16 *)pkey, 0, hash_rnd[0]);
 71}
 72
 73static bool dn_key_eq(const struct neighbour *neigh, const void *pkey)
 74{
 75	return neigh_key_eq16(neigh, pkey);
 76}
 77
 78struct neigh_table dn_neigh_table = {
 79	.family =			PF_DECnet,
 80	.entry_size =			NEIGH_ENTRY_SIZE(sizeof(struct dn_neigh)),
 81	.key_len =			sizeof(__le16),
 82	.protocol =			cpu_to_be16(ETH_P_DNA_RT),
 83	.hash =				dn_neigh_hash,
 84	.key_eq =			dn_key_eq,
 85	.constructor =			dn_neigh_construct,
 86	.id =				"dn_neigh_cache",
 87	.parms ={
 88		.tbl =			&dn_neigh_table,
 89		.reachable_time =	30 * HZ,
 90		.data = {
 91			[NEIGH_VAR_MCAST_PROBES] = 0,
 92			[NEIGH_VAR_UCAST_PROBES] = 0,
 93			[NEIGH_VAR_APP_PROBES] = 0,
 94			[NEIGH_VAR_RETRANS_TIME] = 1 * HZ,
 95			[NEIGH_VAR_BASE_REACHABLE_TIME] = 30 * HZ,
 96			[NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ,
 97			[NEIGH_VAR_GC_STALETIME] = 60 * HZ,
 98			[NEIGH_VAR_QUEUE_LEN_BYTES] = SK_WMEM_MAX,
 99			[NEIGH_VAR_PROXY_QLEN] = 0,
100			[NEIGH_VAR_ANYCAST_DELAY] = 0,
101			[NEIGH_VAR_PROXY_DELAY] = 0,
102			[NEIGH_VAR_LOCKTIME] = 1 * HZ,
103		},
104	},
105	.gc_interval =			30 * HZ,
106	.gc_thresh1 =			128,
107	.gc_thresh2 =			512,
108	.gc_thresh3 =			1024,
109};
110
111static int dn_neigh_construct(struct neighbour *neigh)
112{
113	struct net_device *dev = neigh->dev;
114	struct dn_neigh *dn = container_of(neigh, struct dn_neigh, n);
115	struct dn_dev *dn_db;
116	struct neigh_parms *parms;
117
118	rcu_read_lock();
119	dn_db = rcu_dereference(dev->dn_ptr);
120	if (dn_db == NULL) {
121		rcu_read_unlock();
122		return -EINVAL;
123	}
124
125	parms = dn_db->neigh_parms;
126	if (!parms) {
127		rcu_read_unlock();
128		return -EINVAL;
129	}
130
131	__neigh_parms_put(neigh->parms);
132	neigh->parms = neigh_parms_clone(parms);
133	rcu_read_unlock();
134
135	neigh->ops = &dn_neigh_ops;
136	neigh->nud_state = NUD_NOARP;
137	neigh->output = neigh->ops->connected_output;
138
139	if ((dev->type == ARPHRD_IPGRE) || (dev->flags & IFF_POINTOPOINT))
140		memcpy(neigh->ha, dev->broadcast, dev->addr_len);
141	else if ((dev->type == ARPHRD_ETHER) || (dev->type == ARPHRD_LOOPBACK))
142		dn_dn2eth(neigh->ha, dn->addr);
143	else {
144		net_dbg_ratelimited("Trying to create neigh for hw %d\n",
145				    dev->type);
146		return -EINVAL;
147	}
148
149	/*
150	 * Make an estimate of the remote block size by assuming that its
151	 * two less then the device mtu, which it true for ethernet (and
152	 * other things which support long format headers) since there is
153	 * an extra length field (of 16 bits) which isn't part of the
154	 * ethernet headers and which the DECnet specs won't admit is part
155	 * of the DECnet routing headers either.
156	 *
157	 * If we over estimate here its no big deal, the NSP negotiations
158	 * will prevent us from sending packets which are too large for the
159	 * remote node to handle. In any case this figure is normally updated
160	 * by a hello message in most cases.
161	 */
162	dn->blksize = dev->mtu - 2;
163
164	return 0;
165}
166
167static void dn_neigh_error_report(struct neighbour *neigh, struct sk_buff *skb)
168{
169	printk(KERN_DEBUG "dn_neigh_error_report: called\n");
170	kfree_skb(skb);
171}
172
173static int dn_neigh_output(struct neighbour *neigh, struct sk_buff *skb)
174{
175	struct dst_entry *dst = skb_dst(skb);
176	struct dn_route *rt = (struct dn_route *)dst;
177	struct net_device *dev = neigh->dev;
178	char mac_addr[ETH_ALEN];
179	unsigned int seq;
180	int err;
181
182	dn_dn2eth(mac_addr, rt->rt_local_src);
183	do {
184		seq = read_seqbegin(&neigh->ha_lock);
185		err = dev_hard_header(skb, dev, ntohs(skb->protocol),
186				      neigh->ha, mac_addr, skb->len);
187	} while (read_seqretry(&neigh->ha_lock, seq));
188
189	if (err >= 0)
190		err = dev_queue_xmit(skb);
191	else {
192		kfree_skb(skb);
193		err = -EINVAL;
194	}
195	return err;
196}
197
198static int dn_neigh_output_packet(struct net *net, struct sock *sk, struct sk_buff *skb)
199{
200	struct dst_entry *dst = skb_dst(skb);
201	struct dn_route *rt = (struct dn_route *)dst;
202	struct neighbour *neigh = rt->n;
203
204	return neigh->output(neigh, skb);
205}
206
207/*
208 * For talking to broadcast devices: Ethernet & PPP
209 */
210static int dn_long_output(struct neighbour *neigh, struct sock *sk,
211			  struct sk_buff *skb)
212{
213	struct net_device *dev = neigh->dev;
214	int headroom = dev->hard_header_len + sizeof(struct dn_long_packet) + 3;
215	unsigned char *data;
216	struct dn_long_packet *lp;
217	struct dn_skb_cb *cb = DN_SKB_CB(skb);
218
219
220	if (skb_headroom(skb) < headroom) {
221		struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom);
222		if (skb2 == NULL) {
223			net_crit_ratelimited("dn_long_output: no memory\n");
224			kfree_skb(skb);
225			return -ENOBUFS;
226		}
227		consume_skb(skb);
228		skb = skb2;
229		net_info_ratelimited("dn_long_output: Increasing headroom\n");
230	}
231
232	data = skb_push(skb, sizeof(struct dn_long_packet) + 3);
233	lp = (struct dn_long_packet *)(data+3);
234
235	*((__le16 *)data) = cpu_to_le16(skb->len - 2);
236	*(data + 2) = 1 | DN_RT_F_PF; /* Padding */
237
238	lp->msgflg   = DN_RT_PKT_LONG|(cb->rt_flags&(DN_RT_F_IE|DN_RT_F_RQR|DN_RT_F_RTS));
239	lp->d_area   = lp->d_subarea = 0;
240	dn_dn2eth(lp->d_id, cb->dst);
241	lp->s_area   = lp->s_subarea = 0;
242	dn_dn2eth(lp->s_id, cb->src);
243	lp->nl2      = 0;
244	lp->visit_ct = cb->hops & 0x3f;
245	lp->s_class  = 0;
246	lp->pt       = 0;
247
248	skb_reset_network_header(skb);
249
250	return NF_HOOK(NFPROTO_DECNET, NF_DN_POST_ROUTING,
251		       &init_net, sk, skb, NULL, neigh->dev,
252		       dn_neigh_output_packet);
253}
254
255/*
256 * For talking to pointopoint and multidrop devices: DDCMP and X.25
257 */
258static int dn_short_output(struct neighbour *neigh, struct sock *sk,
259			   struct sk_buff *skb)
260{
261	struct net_device *dev = neigh->dev;
262	int headroom = dev->hard_header_len + sizeof(struct dn_short_packet) + 2;
263	struct dn_short_packet *sp;
264	unsigned char *data;
265	struct dn_skb_cb *cb = DN_SKB_CB(skb);
266
267
268	if (skb_headroom(skb) < headroom) {
269		struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom);
270		if (skb2 == NULL) {
271			net_crit_ratelimited("dn_short_output: no memory\n");
272			kfree_skb(skb);
273			return -ENOBUFS;
274		}
275		consume_skb(skb);
276		skb = skb2;
277		net_info_ratelimited("dn_short_output: Increasing headroom\n");
278	}
279
280	data = skb_push(skb, sizeof(struct dn_short_packet) + 2);
281	*((__le16 *)data) = cpu_to_le16(skb->len - 2);
282	sp = (struct dn_short_packet *)(data+2);
283
284	sp->msgflg     = DN_RT_PKT_SHORT|(cb->rt_flags&(DN_RT_F_RQR|DN_RT_F_RTS));
285	sp->dstnode    = cb->dst;
286	sp->srcnode    = cb->src;
287	sp->forward    = cb->hops & 0x3f;
288
289	skb_reset_network_header(skb);
290
291	return NF_HOOK(NFPROTO_DECNET, NF_DN_POST_ROUTING,
292		       &init_net, sk, skb, NULL, neigh->dev,
293		       dn_neigh_output_packet);
294}
295
296/*
297 * For talking to DECnet phase III nodes
298 * Phase 3 output is the same as short output, execpt that
299 * it clears the area bits before transmission.
300 */
301static int dn_phase3_output(struct neighbour *neigh, struct sock *sk,
302			    struct sk_buff *skb)
303{
304	struct net_device *dev = neigh->dev;
305	int headroom = dev->hard_header_len + sizeof(struct dn_short_packet) + 2;
306	struct dn_short_packet *sp;
307	unsigned char *data;
308	struct dn_skb_cb *cb = DN_SKB_CB(skb);
309
310	if (skb_headroom(skb) < headroom) {
311		struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom);
312		if (skb2 == NULL) {
313			net_crit_ratelimited("dn_phase3_output: no memory\n");
314			kfree_skb(skb);
315			return -ENOBUFS;
316		}
317		consume_skb(skb);
318		skb = skb2;
319		net_info_ratelimited("dn_phase3_output: Increasing headroom\n");
320	}
321
322	data = skb_push(skb, sizeof(struct dn_short_packet) + 2);
323	*((__le16 *)data) = cpu_to_le16(skb->len - 2);
324	sp = (struct dn_short_packet *)(data + 2);
325
326	sp->msgflg   = DN_RT_PKT_SHORT|(cb->rt_flags&(DN_RT_F_RQR|DN_RT_F_RTS));
327	sp->dstnode  = cb->dst & cpu_to_le16(0x03ff);
328	sp->srcnode  = cb->src & cpu_to_le16(0x03ff);
329	sp->forward  = cb->hops & 0x3f;
330
331	skb_reset_network_header(skb);
332
333	return NF_HOOK(NFPROTO_DECNET, NF_DN_POST_ROUTING,
334		       &init_net, sk, skb, NULL, neigh->dev,
335		       dn_neigh_output_packet);
336}
337
338int dn_to_neigh_output(struct net *net, struct sock *sk, struct sk_buff *skb)
339{
340	struct dst_entry *dst = skb_dst(skb);
341	struct dn_route *rt = (struct dn_route *) dst;
342	struct neighbour *neigh = rt->n;
343	struct dn_neigh *dn = container_of(neigh, struct dn_neigh, n);
344	struct dn_dev *dn_db;
345	bool use_long;
346
347	rcu_read_lock();
348	dn_db = rcu_dereference(neigh->dev->dn_ptr);
349	if (dn_db == NULL) {
350		rcu_read_unlock();
351		return -EINVAL;
352	}
353	use_long = dn_db->use_long;
354	rcu_read_unlock();
355
356	if (dn->flags & DN_NDFLAG_P3)
357		return dn_phase3_output(neigh, sk, skb);
358	if (use_long)
359		return dn_long_output(neigh, sk, skb);
360	else
361		return dn_short_output(neigh, sk, skb);
362}
363
364/*
365 * Unfortunately, the neighbour code uses the device in its hash
366 * function, so we don't get any advantage from it. This function
367 * basically does a neigh_lookup(), but without comparing the device
368 * field. This is required for the On-Ethernet cache
369 */
370
371/*
372 * Pointopoint link receives a hello message
373 */
374void dn_neigh_pointopoint_hello(struct sk_buff *skb)
375{
376	kfree_skb(skb);
377}
378
379/*
380 * Ethernet router hello message received
381 */
382int dn_neigh_router_hello(struct net *net, struct sock *sk, struct sk_buff *skb)
383{
384	struct rtnode_hello_message *msg = (struct rtnode_hello_message *)skb->data;
385
386	struct neighbour *neigh;
387	struct dn_neigh *dn;
388	struct dn_dev *dn_db;
389	__le16 src;
390
391	src = dn_eth2dn(msg->id);
392
393	neigh = __neigh_lookup(&dn_neigh_table, &src, skb->dev, 1);
394
395	dn = container_of(neigh, struct dn_neigh, n);
396
397	if (neigh) {
398		write_lock(&neigh->lock);
399
400		neigh->used = jiffies;
401		dn_db = rcu_dereference(neigh->dev->dn_ptr);
402
403		if (!(neigh->nud_state & NUD_PERMANENT)) {
404			neigh->updated = jiffies;
405
406			if (neigh->dev->type == ARPHRD_ETHER)
407				memcpy(neigh->ha, &eth_hdr(skb)->h_source, ETH_ALEN);
408
409			dn->blksize  = le16_to_cpu(msg->blksize);
410			dn->priority = msg->priority;
411
412			dn->flags &= ~DN_NDFLAG_P3;
413
414			switch (msg->iinfo & DN_RT_INFO_TYPE) {
415			case DN_RT_INFO_L1RT:
416				dn->flags &=~DN_NDFLAG_R2;
417				dn->flags |= DN_NDFLAG_R1;
418				break;
419			case DN_RT_INFO_L2RT:
420				dn->flags |= DN_NDFLAG_R2;
421			}
422		}
423
424		/* Only use routers in our area */
425		if ((le16_to_cpu(src)>>10) == (le16_to_cpu((decnet_address))>>10)) {
426			if (!dn_db->router) {
427				dn_db->router = neigh_clone(neigh);
428			} else {
429				if (msg->priority > ((struct dn_neigh *)dn_db->router)->priority)
430					neigh_release(xchg(&dn_db->router, neigh_clone(neigh)));
431			}
432		}
433		write_unlock(&neigh->lock);
434		neigh_release(neigh);
435	}
436
437	kfree_skb(skb);
438	return 0;
439}
440
441/*
442 * Endnode hello message received
443 */
444int dn_neigh_endnode_hello(struct net *net, struct sock *sk, struct sk_buff *skb)
445{
446	struct endnode_hello_message *msg = (struct endnode_hello_message *)skb->data;
447	struct neighbour *neigh;
448	struct dn_neigh *dn;
449	__le16 src;
450
451	src = dn_eth2dn(msg->id);
452
453	neigh = __neigh_lookup(&dn_neigh_table, &src, skb->dev, 1);
454
455	dn = container_of(neigh, struct dn_neigh, n);
456
457	if (neigh) {
458		write_lock(&neigh->lock);
459
460		neigh->used = jiffies;
461
462		if (!(neigh->nud_state & NUD_PERMANENT)) {
463			neigh->updated = jiffies;
464
465			if (neigh->dev->type == ARPHRD_ETHER)
466				memcpy(neigh->ha, &eth_hdr(skb)->h_source, ETH_ALEN);
467			dn->flags   &= ~(DN_NDFLAG_R1 | DN_NDFLAG_R2);
468			dn->blksize  = le16_to_cpu(msg->blksize);
469			dn->priority = 0;
470		}
471
472		write_unlock(&neigh->lock);
473		neigh_release(neigh);
474	}
475
476	kfree_skb(skb);
477	return 0;
478}
479
480static char *dn_find_slot(char *base, int max, int priority)
481{
482	int i;
483	unsigned char *min = NULL;
484
485	base += 6; /* skip first id */
486
487	for(i = 0; i < max; i++) {
488		if (!min || (*base < *min))
489			min = base;
490		base += 7; /* find next priority */
491	}
492
493	if (!min)
494		return NULL;
495
496	return (*min < priority) ? (min - 6) : NULL;
497}
498
499struct elist_cb_state {
500	struct net_device *dev;
501	unsigned char *ptr;
502	unsigned char *rs;
503	int t, n;
504};
505
506static void neigh_elist_cb(struct neighbour *neigh, void *_info)
507{
508	struct elist_cb_state *s = _info;
509	struct dn_neigh *dn;
510
511	if (neigh->dev != s->dev)
512		return;
513
514	dn = container_of(neigh, struct dn_neigh, n);
515	if (!(dn->flags & (DN_NDFLAG_R1|DN_NDFLAG_R2)))
516		return;
517
518	if (s->t == s->n)
519		s->rs = dn_find_slot(s->ptr, s->n, dn->priority);
520	else
521		s->t++;
522	if (s->rs == NULL)
523		return;
524
525	dn_dn2eth(s->rs, dn->addr);
526	s->rs += 6;
527	*(s->rs) = neigh->nud_state & NUD_CONNECTED ? 0x80 : 0x0;
528	*(s->rs) |= dn->priority;
529	s->rs++;
530}
531
532int dn_neigh_elist(struct net_device *dev, unsigned char *ptr, int n)
533{
534	struct elist_cb_state state;
535
536	state.dev = dev;
537	state.t = 0;
538	state.n = n;
539	state.ptr = ptr;
540	state.rs = ptr;
541
542	neigh_for_each(&dn_neigh_table, neigh_elist_cb, &state);
543
544	return state.t;
545}
546
547
548#ifdef CONFIG_PROC_FS
549
550static inline void dn_neigh_format_entry(struct seq_file *seq,
551					 struct neighbour *n)
552{
553	struct dn_neigh *dn = container_of(n, struct dn_neigh, n);
554	char buf[DN_ASCBUF_LEN];
555
556	read_lock(&n->lock);
557	seq_printf(seq, "%-7s %s%s%s   %02x    %02d  %07ld %-8s\n",
558		   dn_addr2asc(le16_to_cpu(dn->addr), buf),
559		   (dn->flags&DN_NDFLAG_R1) ? "1" : "-",
560		   (dn->flags&DN_NDFLAG_R2) ? "2" : "-",
561		   (dn->flags&DN_NDFLAG_P3) ? "3" : "-",
562		   dn->n.nud_state,
563		   refcount_read(&dn->n.refcnt),
564		   dn->blksize,
565		   (dn->n.dev) ? dn->n.dev->name : "?");
566	read_unlock(&n->lock);
567}
568
569static int dn_neigh_seq_show(struct seq_file *seq, void *v)
570{
571	if (v == SEQ_START_TOKEN) {
572		seq_puts(seq, "Addr    Flags State Use Blksize Dev\n");
573	} else {
574		dn_neigh_format_entry(seq, v);
575	}
576
577	return 0;
578}
579
580static void *dn_neigh_seq_start(struct seq_file *seq, loff_t *pos)
581{
582	return neigh_seq_start(seq, pos, &dn_neigh_table,
583			       NEIGH_SEQ_NEIGH_ONLY);
584}
585
586static const struct seq_operations dn_neigh_seq_ops = {
587	.start = dn_neigh_seq_start,
588	.next  = neigh_seq_next,
589	.stop  = neigh_seq_stop,
590	.show  = dn_neigh_seq_show,
591};
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
592#endif
593
594void __init dn_neigh_init(void)
595{
596	neigh_table_init(NEIGH_DN_TABLE, &dn_neigh_table);
597	proc_create_net("decnet_neigh", 0444, init_net.proc_net,
598			&dn_neigh_seq_ops, sizeof(struct neigh_seq_state));
599}
600
601void __exit dn_neigh_cleanup(void)
602{
603	remove_proc_entry("decnet_neigh", init_net.proc_net);
604	neigh_table_clear(NEIGH_DN_TABLE, &dn_neigh_table);
605}
v4.10.11
 
  1/*
  2 * DECnet       An implementation of the DECnet protocol suite for the LINUX
  3 *              operating system.  DECnet is implemented using the  BSD Socket
  4 *              interface as the means of communication with the user level.
  5 *
  6 *              DECnet Neighbour Functions (Adjacency Database and
  7 *                                                        On-Ethernet Cache)
  8 *
  9 * Author:      Steve Whitehouse <SteveW@ACM.org>
 10 *
 11 *
 12 * Changes:
 13 *     Steve Whitehouse     : Fixed router listing routine
 14 *     Steve Whitehouse     : Added error_report functions
 15 *     Steve Whitehouse     : Added default router detection
 16 *     Steve Whitehouse     : Hop counts in outgoing messages
 17 *     Steve Whitehouse     : Fixed src/dst in outgoing messages so
 18 *                            forwarding now stands a good chance of
 19 *                            working.
 20 *     Steve Whitehouse     : Fixed neighbour states (for now anyway).
 21 *     Steve Whitehouse     : Made error_report functions dummies. This
 22 *                            is not the right place to return skbs.
 23 *     Steve Whitehouse     : Convert to seq_file
 24 *
 25 */
 26
 27#include <linux/net.h>
 28#include <linux/module.h>
 29#include <linux/socket.h>
 30#include <linux/if_arp.h>
 31#include <linux/slab.h>
 32#include <linux/if_ether.h>
 33#include <linux/init.h>
 34#include <linux/proc_fs.h>
 35#include <linux/string.h>
 36#include <linux/netfilter_decnet.h>
 37#include <linux/spinlock.h>
 38#include <linux/seq_file.h>
 39#include <linux/rcupdate.h>
 40#include <linux/jhash.h>
 41#include <linux/atomic.h>
 42#include <net/net_namespace.h>
 43#include <net/neighbour.h>
 44#include <net/dst.h>
 45#include <net/flow.h>
 46#include <net/dn.h>
 47#include <net/dn_dev.h>
 48#include <net/dn_neigh.h>
 49#include <net/dn_route.h>
 50
 51static int dn_neigh_construct(struct neighbour *);
 52static void dn_neigh_error_report(struct neighbour *, struct sk_buff *);
 53static int dn_neigh_output(struct neighbour *neigh, struct sk_buff *skb);
 54
 55/*
 56 * Operations for adding the link layer header.
 57 */
 58static const struct neigh_ops dn_neigh_ops = {
 59	.family =		AF_DECnet,
 60	.error_report =		dn_neigh_error_report,
 61	.output =		dn_neigh_output,
 62	.connected_output =	dn_neigh_output,
 63};
 64
 65static u32 dn_neigh_hash(const void *pkey,
 66			 const struct net_device *dev,
 67			 __u32 *hash_rnd)
 68{
 69	return jhash_2words(*(__u16 *)pkey, 0, hash_rnd[0]);
 70}
 71
 72static bool dn_key_eq(const struct neighbour *neigh, const void *pkey)
 73{
 74	return neigh_key_eq16(neigh, pkey);
 75}
 76
 77struct neigh_table dn_neigh_table = {
 78	.family =			PF_DECnet,
 79	.entry_size =			NEIGH_ENTRY_SIZE(sizeof(struct dn_neigh)),
 80	.key_len =			sizeof(__le16),
 81	.protocol =			cpu_to_be16(ETH_P_DNA_RT),
 82	.hash =				dn_neigh_hash,
 83	.key_eq =			dn_key_eq,
 84	.constructor =			dn_neigh_construct,
 85	.id =				"dn_neigh_cache",
 86	.parms ={
 87		.tbl =			&dn_neigh_table,
 88		.reachable_time =	30 * HZ,
 89		.data = {
 90			[NEIGH_VAR_MCAST_PROBES] = 0,
 91			[NEIGH_VAR_UCAST_PROBES] = 0,
 92			[NEIGH_VAR_APP_PROBES] = 0,
 93			[NEIGH_VAR_RETRANS_TIME] = 1 * HZ,
 94			[NEIGH_VAR_BASE_REACHABLE_TIME] = 30 * HZ,
 95			[NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ,
 96			[NEIGH_VAR_GC_STALETIME] = 60 * HZ,
 97			[NEIGH_VAR_QUEUE_LEN_BYTES] = 64*1024,
 98			[NEIGH_VAR_PROXY_QLEN] = 0,
 99			[NEIGH_VAR_ANYCAST_DELAY] = 0,
100			[NEIGH_VAR_PROXY_DELAY] = 0,
101			[NEIGH_VAR_LOCKTIME] = 1 * HZ,
102		},
103	},
104	.gc_interval =			30 * HZ,
105	.gc_thresh1 =			128,
106	.gc_thresh2 =			512,
107	.gc_thresh3 =			1024,
108};
109
110static int dn_neigh_construct(struct neighbour *neigh)
111{
112	struct net_device *dev = neigh->dev;
113	struct dn_neigh *dn = (struct dn_neigh *)neigh;
114	struct dn_dev *dn_db;
115	struct neigh_parms *parms;
116
117	rcu_read_lock();
118	dn_db = rcu_dereference(dev->dn_ptr);
119	if (dn_db == NULL) {
120		rcu_read_unlock();
121		return -EINVAL;
122	}
123
124	parms = dn_db->neigh_parms;
125	if (!parms) {
126		rcu_read_unlock();
127		return -EINVAL;
128	}
129
130	__neigh_parms_put(neigh->parms);
131	neigh->parms = neigh_parms_clone(parms);
132	rcu_read_unlock();
133
134	neigh->ops = &dn_neigh_ops;
135	neigh->nud_state = NUD_NOARP;
136	neigh->output = neigh->ops->connected_output;
137
138	if ((dev->type == ARPHRD_IPGRE) || (dev->flags & IFF_POINTOPOINT))
139		memcpy(neigh->ha, dev->broadcast, dev->addr_len);
140	else if ((dev->type == ARPHRD_ETHER) || (dev->type == ARPHRD_LOOPBACK))
141		dn_dn2eth(neigh->ha, dn->addr);
142	else {
143		net_dbg_ratelimited("Trying to create neigh for hw %d\n",
144				    dev->type);
145		return -EINVAL;
146	}
147
148	/*
149	 * Make an estimate of the remote block size by assuming that its
150	 * two less then the device mtu, which it true for ethernet (and
151	 * other things which support long format headers) since there is
152	 * an extra length field (of 16 bits) which isn't part of the
153	 * ethernet headers and which the DECnet specs won't admit is part
154	 * of the DECnet routing headers either.
155	 *
156	 * If we over estimate here its no big deal, the NSP negotiations
157	 * will prevent us from sending packets which are too large for the
158	 * remote node to handle. In any case this figure is normally updated
159	 * by a hello message in most cases.
160	 */
161	dn->blksize = dev->mtu - 2;
162
163	return 0;
164}
165
166static void dn_neigh_error_report(struct neighbour *neigh, struct sk_buff *skb)
167{
168	printk(KERN_DEBUG "dn_neigh_error_report: called\n");
169	kfree_skb(skb);
170}
171
172static int dn_neigh_output(struct neighbour *neigh, struct sk_buff *skb)
173{
174	struct dst_entry *dst = skb_dst(skb);
175	struct dn_route *rt = (struct dn_route *)dst;
176	struct net_device *dev = neigh->dev;
177	char mac_addr[ETH_ALEN];
178	unsigned int seq;
179	int err;
180
181	dn_dn2eth(mac_addr, rt->rt_local_src);
182	do {
183		seq = read_seqbegin(&neigh->ha_lock);
184		err = dev_hard_header(skb, dev, ntohs(skb->protocol),
185				      neigh->ha, mac_addr, skb->len);
186	} while (read_seqretry(&neigh->ha_lock, seq));
187
188	if (err >= 0)
189		err = dev_queue_xmit(skb);
190	else {
191		kfree_skb(skb);
192		err = -EINVAL;
193	}
194	return err;
195}
196
197static int dn_neigh_output_packet(struct net *net, struct sock *sk, struct sk_buff *skb)
198{
199	struct dst_entry *dst = skb_dst(skb);
200	struct dn_route *rt = (struct dn_route *)dst;
201	struct neighbour *neigh = rt->n;
202
203	return neigh->output(neigh, skb);
204}
205
206/*
207 * For talking to broadcast devices: Ethernet & PPP
208 */
209static int dn_long_output(struct neighbour *neigh, struct sock *sk,
210			  struct sk_buff *skb)
211{
212	struct net_device *dev = neigh->dev;
213	int headroom = dev->hard_header_len + sizeof(struct dn_long_packet) + 3;
214	unsigned char *data;
215	struct dn_long_packet *lp;
216	struct dn_skb_cb *cb = DN_SKB_CB(skb);
217
218
219	if (skb_headroom(skb) < headroom) {
220		struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom);
221		if (skb2 == NULL) {
222			net_crit_ratelimited("dn_long_output: no memory\n");
223			kfree_skb(skb);
224			return -ENOBUFS;
225		}
226		consume_skb(skb);
227		skb = skb2;
228		net_info_ratelimited("dn_long_output: Increasing headroom\n");
229	}
230
231	data = skb_push(skb, sizeof(struct dn_long_packet) + 3);
232	lp = (struct dn_long_packet *)(data+3);
233
234	*((__le16 *)data) = cpu_to_le16(skb->len - 2);
235	*(data + 2) = 1 | DN_RT_F_PF; /* Padding */
236
237	lp->msgflg   = DN_RT_PKT_LONG|(cb->rt_flags&(DN_RT_F_IE|DN_RT_F_RQR|DN_RT_F_RTS));
238	lp->d_area   = lp->d_subarea = 0;
239	dn_dn2eth(lp->d_id, cb->dst);
240	lp->s_area   = lp->s_subarea = 0;
241	dn_dn2eth(lp->s_id, cb->src);
242	lp->nl2      = 0;
243	lp->visit_ct = cb->hops & 0x3f;
244	lp->s_class  = 0;
245	lp->pt       = 0;
246
247	skb_reset_network_header(skb);
248
249	return NF_HOOK(NFPROTO_DECNET, NF_DN_POST_ROUTING,
250		       &init_net, sk, skb, NULL, neigh->dev,
251		       dn_neigh_output_packet);
252}
253
254/*
255 * For talking to pointopoint and multidrop devices: DDCMP and X.25
256 */
257static int dn_short_output(struct neighbour *neigh, struct sock *sk,
258			   struct sk_buff *skb)
259{
260	struct net_device *dev = neigh->dev;
261	int headroom = dev->hard_header_len + sizeof(struct dn_short_packet) + 2;
262	struct dn_short_packet *sp;
263	unsigned char *data;
264	struct dn_skb_cb *cb = DN_SKB_CB(skb);
265
266
267	if (skb_headroom(skb) < headroom) {
268		struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom);
269		if (skb2 == NULL) {
270			net_crit_ratelimited("dn_short_output: no memory\n");
271			kfree_skb(skb);
272			return -ENOBUFS;
273		}
274		consume_skb(skb);
275		skb = skb2;
276		net_info_ratelimited("dn_short_output: Increasing headroom\n");
277	}
278
279	data = skb_push(skb, sizeof(struct dn_short_packet) + 2);
280	*((__le16 *)data) = cpu_to_le16(skb->len - 2);
281	sp = (struct dn_short_packet *)(data+2);
282
283	sp->msgflg     = DN_RT_PKT_SHORT|(cb->rt_flags&(DN_RT_F_RQR|DN_RT_F_RTS));
284	sp->dstnode    = cb->dst;
285	sp->srcnode    = cb->src;
286	sp->forward    = cb->hops & 0x3f;
287
288	skb_reset_network_header(skb);
289
290	return NF_HOOK(NFPROTO_DECNET, NF_DN_POST_ROUTING,
291		       &init_net, sk, skb, NULL, neigh->dev,
292		       dn_neigh_output_packet);
293}
294
295/*
296 * For talking to DECnet phase III nodes
297 * Phase 3 output is the same as short output, execpt that
298 * it clears the area bits before transmission.
299 */
300static int dn_phase3_output(struct neighbour *neigh, struct sock *sk,
301			    struct sk_buff *skb)
302{
303	struct net_device *dev = neigh->dev;
304	int headroom = dev->hard_header_len + sizeof(struct dn_short_packet) + 2;
305	struct dn_short_packet *sp;
306	unsigned char *data;
307	struct dn_skb_cb *cb = DN_SKB_CB(skb);
308
309	if (skb_headroom(skb) < headroom) {
310		struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom);
311		if (skb2 == NULL) {
312			net_crit_ratelimited("dn_phase3_output: no memory\n");
313			kfree_skb(skb);
314			return -ENOBUFS;
315		}
316		consume_skb(skb);
317		skb = skb2;
318		net_info_ratelimited("dn_phase3_output: Increasing headroom\n");
319	}
320
321	data = skb_push(skb, sizeof(struct dn_short_packet) + 2);
322	*((__le16 *)data) = cpu_to_le16(skb->len - 2);
323	sp = (struct dn_short_packet *)(data + 2);
324
325	sp->msgflg   = DN_RT_PKT_SHORT|(cb->rt_flags&(DN_RT_F_RQR|DN_RT_F_RTS));
326	sp->dstnode  = cb->dst & cpu_to_le16(0x03ff);
327	sp->srcnode  = cb->src & cpu_to_le16(0x03ff);
328	sp->forward  = cb->hops & 0x3f;
329
330	skb_reset_network_header(skb);
331
332	return NF_HOOK(NFPROTO_DECNET, NF_DN_POST_ROUTING,
333		       &init_net, sk, skb, NULL, neigh->dev,
334		       dn_neigh_output_packet);
335}
336
337int dn_to_neigh_output(struct net *net, struct sock *sk, struct sk_buff *skb)
338{
339	struct dst_entry *dst = skb_dst(skb);
340	struct dn_route *rt = (struct dn_route *) dst;
341	struct neighbour *neigh = rt->n;
342	struct dn_neigh *dn = (struct dn_neigh *)neigh;
343	struct dn_dev *dn_db;
344	bool use_long;
345
346	rcu_read_lock();
347	dn_db = rcu_dereference(neigh->dev->dn_ptr);
348	if (dn_db == NULL) {
349		rcu_read_unlock();
350		return -EINVAL;
351	}
352	use_long = dn_db->use_long;
353	rcu_read_unlock();
354
355	if (dn->flags & DN_NDFLAG_P3)
356		return dn_phase3_output(neigh, sk, skb);
357	if (use_long)
358		return dn_long_output(neigh, sk, skb);
359	else
360		return dn_short_output(neigh, sk, skb);
361}
362
363/*
364 * Unfortunately, the neighbour code uses the device in its hash
365 * function, so we don't get any advantage from it. This function
366 * basically does a neigh_lookup(), but without comparing the device
367 * field. This is required for the On-Ethernet cache
368 */
369
370/*
371 * Pointopoint link receives a hello message
372 */
373void dn_neigh_pointopoint_hello(struct sk_buff *skb)
374{
375	kfree_skb(skb);
376}
377
378/*
379 * Ethernet router hello message received
380 */
381int dn_neigh_router_hello(struct net *net, struct sock *sk, struct sk_buff *skb)
382{
383	struct rtnode_hello_message *msg = (struct rtnode_hello_message *)skb->data;
384
385	struct neighbour *neigh;
386	struct dn_neigh *dn;
387	struct dn_dev *dn_db;
388	__le16 src;
389
390	src = dn_eth2dn(msg->id);
391
392	neigh = __neigh_lookup(&dn_neigh_table, &src, skb->dev, 1);
393
394	dn = (struct dn_neigh *)neigh;
395
396	if (neigh) {
397		write_lock(&neigh->lock);
398
399		neigh->used = jiffies;
400		dn_db = rcu_dereference(neigh->dev->dn_ptr);
401
402		if (!(neigh->nud_state & NUD_PERMANENT)) {
403			neigh->updated = jiffies;
404
405			if (neigh->dev->type == ARPHRD_ETHER)
406				memcpy(neigh->ha, &eth_hdr(skb)->h_source, ETH_ALEN);
407
408			dn->blksize  = le16_to_cpu(msg->blksize);
409			dn->priority = msg->priority;
410
411			dn->flags &= ~DN_NDFLAG_P3;
412
413			switch (msg->iinfo & DN_RT_INFO_TYPE) {
414			case DN_RT_INFO_L1RT:
415				dn->flags &=~DN_NDFLAG_R2;
416				dn->flags |= DN_NDFLAG_R1;
417				break;
418			case DN_RT_INFO_L2RT:
419				dn->flags |= DN_NDFLAG_R2;
420			}
421		}
422
423		/* Only use routers in our area */
424		if ((le16_to_cpu(src)>>10) == (le16_to_cpu((decnet_address))>>10)) {
425			if (!dn_db->router) {
426				dn_db->router = neigh_clone(neigh);
427			} else {
428				if (msg->priority > ((struct dn_neigh *)dn_db->router)->priority)
429					neigh_release(xchg(&dn_db->router, neigh_clone(neigh)));
430			}
431		}
432		write_unlock(&neigh->lock);
433		neigh_release(neigh);
434	}
435
436	kfree_skb(skb);
437	return 0;
438}
439
440/*
441 * Endnode hello message received
442 */
443int dn_neigh_endnode_hello(struct net *net, struct sock *sk, struct sk_buff *skb)
444{
445	struct endnode_hello_message *msg = (struct endnode_hello_message *)skb->data;
446	struct neighbour *neigh;
447	struct dn_neigh *dn;
448	__le16 src;
449
450	src = dn_eth2dn(msg->id);
451
452	neigh = __neigh_lookup(&dn_neigh_table, &src, skb->dev, 1);
453
454	dn = (struct dn_neigh *)neigh;
455
456	if (neigh) {
457		write_lock(&neigh->lock);
458
459		neigh->used = jiffies;
460
461		if (!(neigh->nud_state & NUD_PERMANENT)) {
462			neigh->updated = jiffies;
463
464			if (neigh->dev->type == ARPHRD_ETHER)
465				memcpy(neigh->ha, &eth_hdr(skb)->h_source, ETH_ALEN);
466			dn->flags   &= ~(DN_NDFLAG_R1 | DN_NDFLAG_R2);
467			dn->blksize  = le16_to_cpu(msg->blksize);
468			dn->priority = 0;
469		}
470
471		write_unlock(&neigh->lock);
472		neigh_release(neigh);
473	}
474
475	kfree_skb(skb);
476	return 0;
477}
478
479static char *dn_find_slot(char *base, int max, int priority)
480{
481	int i;
482	unsigned char *min = NULL;
483
484	base += 6; /* skip first id */
485
486	for(i = 0; i < max; i++) {
487		if (!min || (*base < *min))
488			min = base;
489		base += 7; /* find next priority */
490	}
491
492	if (!min)
493		return NULL;
494
495	return (*min < priority) ? (min - 6) : NULL;
496}
497
498struct elist_cb_state {
499	struct net_device *dev;
500	unsigned char *ptr;
501	unsigned char *rs;
502	int t, n;
503};
504
505static void neigh_elist_cb(struct neighbour *neigh, void *_info)
506{
507	struct elist_cb_state *s = _info;
508	struct dn_neigh *dn;
509
510	if (neigh->dev != s->dev)
511		return;
512
513	dn = (struct dn_neigh *) neigh;
514	if (!(dn->flags & (DN_NDFLAG_R1|DN_NDFLAG_R2)))
515		return;
516
517	if (s->t == s->n)
518		s->rs = dn_find_slot(s->ptr, s->n, dn->priority);
519	else
520		s->t++;
521	if (s->rs == NULL)
522		return;
523
524	dn_dn2eth(s->rs, dn->addr);
525	s->rs += 6;
526	*(s->rs) = neigh->nud_state & NUD_CONNECTED ? 0x80 : 0x0;
527	*(s->rs) |= dn->priority;
528	s->rs++;
529}
530
531int dn_neigh_elist(struct net_device *dev, unsigned char *ptr, int n)
532{
533	struct elist_cb_state state;
534
535	state.dev = dev;
536	state.t = 0;
537	state.n = n;
538	state.ptr = ptr;
539	state.rs = ptr;
540
541	neigh_for_each(&dn_neigh_table, neigh_elist_cb, &state);
542
543	return state.t;
544}
545
546
547#ifdef CONFIG_PROC_FS
548
549static inline void dn_neigh_format_entry(struct seq_file *seq,
550					 struct neighbour *n)
551{
552	struct dn_neigh *dn = (struct dn_neigh *) n;
553	char buf[DN_ASCBUF_LEN];
554
555	read_lock(&n->lock);
556	seq_printf(seq, "%-7s %s%s%s   %02x    %02d  %07ld %-8s\n",
557		   dn_addr2asc(le16_to_cpu(dn->addr), buf),
558		   (dn->flags&DN_NDFLAG_R1) ? "1" : "-",
559		   (dn->flags&DN_NDFLAG_R2) ? "2" : "-",
560		   (dn->flags&DN_NDFLAG_P3) ? "3" : "-",
561		   dn->n.nud_state,
562		   atomic_read(&dn->n.refcnt),
563		   dn->blksize,
564		   (dn->n.dev) ? dn->n.dev->name : "?");
565	read_unlock(&n->lock);
566}
567
568static int dn_neigh_seq_show(struct seq_file *seq, void *v)
569{
570	if (v == SEQ_START_TOKEN) {
571		seq_puts(seq, "Addr    Flags State Use Blksize Dev\n");
572	} else {
573		dn_neigh_format_entry(seq, v);
574	}
575
576	return 0;
577}
578
579static void *dn_neigh_seq_start(struct seq_file *seq, loff_t *pos)
580{
581	return neigh_seq_start(seq, pos, &dn_neigh_table,
582			       NEIGH_SEQ_NEIGH_ONLY);
583}
584
585static const struct seq_operations dn_neigh_seq_ops = {
586	.start = dn_neigh_seq_start,
587	.next  = neigh_seq_next,
588	.stop  = neigh_seq_stop,
589	.show  = dn_neigh_seq_show,
590};
591
592static int dn_neigh_seq_open(struct inode *inode, struct file *file)
593{
594	return seq_open_net(inode, file, &dn_neigh_seq_ops,
595			    sizeof(struct neigh_seq_state));
596}
597
598static const struct file_operations dn_neigh_seq_fops = {
599	.owner		= THIS_MODULE,
600	.open		= dn_neigh_seq_open,
601	.read		= seq_read,
602	.llseek		= seq_lseek,
603	.release	= seq_release_net,
604};
605
606#endif
607
608void __init dn_neigh_init(void)
609{
610	neigh_table_init(NEIGH_DN_TABLE, &dn_neigh_table);
611	proc_create("decnet_neigh", S_IRUGO, init_net.proc_net,
612		    &dn_neigh_seq_fops);
613}
614
615void __exit dn_neigh_cleanup(void)
616{
617	remove_proc_entry("decnet_neigh", init_net.proc_net);
618	neigh_table_clear(NEIGH_DN_TABLE, &dn_neigh_table);
619}