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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, ð_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, ð_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}