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/if_ether.h>
32 #include <linux/init.h>
33 #include <linux/proc_fs.h>
34 #include <linux/string.h>
35 #include <linux/netfilter_decnet.h>
36 #include <linux/spinlock.h>
37 #include <linux/seq_file.h>
38 #include <linux/rcupdate.h>
39 #include <linux/jhash.h>
40 #include <asm/atomic.h>
41 #include <net/net_namespace.h>
42 #include <net/neighbour.h>
43 #include <net/dst.h>
44 #include <net/flow.h>
45 #include <net/dn.h>
46 #include <net/dn_dev.h>
47 #include <net/dn_neigh.h>
48 #include <net/dn_route.h>
49
50 static u32 dn_neigh_hash(const void *pkey, const struct net_device *dev);
51 static int dn_neigh_construct(struct neighbour *);
52 static void dn_long_error_report(struct neighbour *, struct sk_buff *);
53 static void dn_short_error_report(struct neighbour *, struct sk_buff *);
54 static int dn_long_output(struct sk_buff *);
55 static int dn_short_output(struct sk_buff *);
56 static int dn_phase3_output(struct sk_buff *);
57
58
59 /*
60 * For talking to broadcast devices: Ethernet & PPP
61 */
62 static struct neigh_ops dn_long_ops = {
63 .family = AF_DECnet,
64 .error_report = dn_long_error_report,
65 .output = dn_long_output,
66 .connected_output = dn_long_output,
67 .hh_output = dev_queue_xmit,
68 .queue_xmit = dev_queue_xmit,
69 };
70
71 /*
72 * For talking to pointopoint and multidrop devices: DDCMP and X.25
73 */
74 static struct neigh_ops dn_short_ops = {
75 .family = AF_DECnet,
76 .error_report = dn_short_error_report,
77 .output = dn_short_output,
78 .connected_output = dn_short_output,
79 .hh_output = dev_queue_xmit,
80 .queue_xmit = dev_queue_xmit,
81 };
82
83 /*
84 * For talking to DECnet phase III nodes
85 */
86 static struct neigh_ops dn_phase3_ops = {
87 .family = AF_DECnet,
88 .error_report = dn_short_error_report, /* Can use short version here */
89 .output = dn_phase3_output,
90 .connected_output = dn_phase3_output,
91 .hh_output = dev_queue_xmit,
92 .queue_xmit = dev_queue_xmit
93 };
94
95 struct neigh_table dn_neigh_table = {
96 .family = PF_DECnet,
97 .entry_size = sizeof(struct dn_neigh),
98 .key_len = sizeof(__le16),
99 .hash = dn_neigh_hash,
100 .constructor = dn_neigh_construct,
101 .id = "dn_neigh_cache",
102 .parms ={
103 .tbl = &dn_neigh_table,
104 .base_reachable_time = 30 * HZ,
105 .retrans_time = 1 * HZ,
106 .gc_staletime = 60 * HZ,
107 .reachable_time = 30 * HZ,
108 .delay_probe_time = 5 * HZ,
109 .queue_len = 3,
110 .ucast_probes = 0,
111 .app_probes = 0,
112 .mcast_probes = 0,
113 .anycast_delay = 0,
114 .proxy_delay = 0,
115 .proxy_qlen = 0,
116 .locktime = 1 * HZ,
117 },
118 .gc_interval = 30 * HZ,
119 .gc_thresh1 = 128,
120 .gc_thresh2 = 512,
121 .gc_thresh3 = 1024,
122 };
123
dn_neigh_hash(const void * pkey,const struct net_device * dev)124 static u32 dn_neigh_hash(const void *pkey, const struct net_device *dev)
125 {
126 return jhash_2words(*(__u16 *)pkey, 0, dn_neigh_table.hash_rnd);
127 }
128
dn_neigh_construct(struct neighbour * neigh)129 static int dn_neigh_construct(struct neighbour *neigh)
130 {
131 struct net_device *dev = neigh->dev;
132 struct dn_neigh *dn = (struct dn_neigh *)neigh;
133 struct dn_dev *dn_db;
134 struct neigh_parms *parms;
135
136 rcu_read_lock();
137 dn_db = rcu_dereference(dev->dn_ptr);
138 if (dn_db == NULL) {
139 rcu_read_unlock();
140 return -EINVAL;
141 }
142
143 parms = dn_db->neigh_parms;
144 if (!parms) {
145 rcu_read_unlock();
146 return -EINVAL;
147 }
148
149 __neigh_parms_put(neigh->parms);
150 neigh->parms = neigh_parms_clone(parms);
151
152 if (dn_db->use_long)
153 neigh->ops = &dn_long_ops;
154 else
155 neigh->ops = &dn_short_ops;
156 rcu_read_unlock();
157
158 if (dn->flags & DN_NDFLAG_P3)
159 neigh->ops = &dn_phase3_ops;
160
161 neigh->nud_state = NUD_NOARP;
162 neigh->output = neigh->ops->connected_output;
163
164 if ((dev->type == ARPHRD_IPGRE) || (dev->flags & IFF_POINTOPOINT))
165 memcpy(neigh->ha, dev->broadcast, dev->addr_len);
166 else if ((dev->type == ARPHRD_ETHER) || (dev->type == ARPHRD_LOOPBACK))
167 dn_dn2eth(neigh->ha, dn->addr);
168 else {
169 if (net_ratelimit())
170 printk(KERN_DEBUG "Trying to create neigh for hw %d\n", dev->type);
171 return -EINVAL;
172 }
173
174 /*
175 * Make an estimate of the remote block size by assuming that its
176 * two less then the device mtu, which it true for ethernet (and
177 * other things which support long format headers) since there is
178 * an extra length field (of 16 bits) which isn't part of the
179 * ethernet headers and which the DECnet specs won't admit is part
180 * of the DECnet routing headers either.
181 *
182 * If we over estimate here its no big deal, the NSP negotiations
183 * will prevent us from sending packets which are too large for the
184 * remote node to handle. In any case this figure is normally updated
185 * by a hello message in most cases.
186 */
187 dn->blksize = dev->mtu - 2;
188
189 return 0;
190 }
191
dn_long_error_report(struct neighbour * neigh,struct sk_buff * skb)192 static void dn_long_error_report(struct neighbour *neigh, struct sk_buff *skb)
193 {
194 printk(KERN_DEBUG "dn_long_error_report: called\n");
195 kfree_skb(skb);
196 }
197
198
dn_short_error_report(struct neighbour * neigh,struct sk_buff * skb)199 static void dn_short_error_report(struct neighbour *neigh, struct sk_buff *skb)
200 {
201 printk(KERN_DEBUG "dn_short_error_report: called\n");
202 kfree_skb(skb);
203 }
204
dn_neigh_output_packet(struct sk_buff * skb)205 static int dn_neigh_output_packet(struct sk_buff *skb)
206 {
207 struct dst_entry *dst = skb->dst;
208 struct dn_route *rt = (struct dn_route *)dst;
209 struct neighbour *neigh = dst->neighbour;
210 struct net_device *dev = neigh->dev;
211 char mac_addr[ETH_ALEN];
212
213 dn_dn2eth(mac_addr, rt->rt_local_src);
214 if (dev_hard_header(skb, dev, ntohs(skb->protocol), neigh->ha,
215 mac_addr, skb->len) >= 0)
216 return neigh->ops->queue_xmit(skb);
217
218 if (net_ratelimit())
219 printk(KERN_DEBUG "dn_neigh_output_packet: oops, can't send packet\n");
220
221 kfree_skb(skb);
222 return -EINVAL;
223 }
224
dn_long_output(struct sk_buff * skb)225 static int dn_long_output(struct sk_buff *skb)
226 {
227 struct dst_entry *dst = skb->dst;
228 struct neighbour *neigh = dst->neighbour;
229 struct net_device *dev = neigh->dev;
230 int headroom = dev->hard_header_len + sizeof(struct dn_long_packet) + 3;
231 unsigned char *data;
232 struct dn_long_packet *lp;
233 struct dn_skb_cb *cb = DN_SKB_CB(skb);
234
235
236 if (skb_headroom(skb) < headroom) {
237 struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom);
238 if (skb2 == NULL) {
239 if (net_ratelimit())
240 printk(KERN_CRIT "dn_long_output: no memory\n");
241 kfree_skb(skb);
242 return -ENOBUFS;
243 }
244 kfree_skb(skb);
245 skb = skb2;
246 if (net_ratelimit())
247 printk(KERN_INFO "dn_long_output: Increasing headroom\n");
248 }
249
250 data = skb_push(skb, sizeof(struct dn_long_packet) + 3);
251 lp = (struct dn_long_packet *)(data+3);
252
253 *((__le16 *)data) = cpu_to_le16(skb->len - 2);
254 *(data + 2) = 1 | DN_RT_F_PF; /* Padding */
255
256 lp->msgflg = DN_RT_PKT_LONG|(cb->rt_flags&(DN_RT_F_IE|DN_RT_F_RQR|DN_RT_F_RTS));
257 lp->d_area = lp->d_subarea = 0;
258 dn_dn2eth(lp->d_id, cb->dst);
259 lp->s_area = lp->s_subarea = 0;
260 dn_dn2eth(lp->s_id, cb->src);
261 lp->nl2 = 0;
262 lp->visit_ct = cb->hops & 0x3f;
263 lp->s_class = 0;
264 lp->pt = 0;
265
266 skb_reset_network_header(skb);
267
268 return NF_HOOK(PF_DECnet, NF_DN_POST_ROUTING, skb, NULL, neigh->dev, dn_neigh_output_packet);
269 }
270
dn_short_output(struct sk_buff * skb)271 static int dn_short_output(struct sk_buff *skb)
272 {
273 struct dst_entry *dst = skb->dst;
274 struct neighbour *neigh = dst->neighbour;
275 struct net_device *dev = neigh->dev;
276 int headroom = dev->hard_header_len + sizeof(struct dn_short_packet) + 2;
277 struct dn_short_packet *sp;
278 unsigned char *data;
279 struct dn_skb_cb *cb = DN_SKB_CB(skb);
280
281
282 if (skb_headroom(skb) < headroom) {
283 struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom);
284 if (skb2 == NULL) {
285 if (net_ratelimit())
286 printk(KERN_CRIT "dn_short_output: no memory\n");
287 kfree_skb(skb);
288 return -ENOBUFS;
289 }
290 kfree_skb(skb);
291 skb = skb2;
292 if (net_ratelimit())
293 printk(KERN_INFO "dn_short_output: Increasing headroom\n");
294 }
295
296 data = skb_push(skb, sizeof(struct dn_short_packet) + 2);
297 *((__le16 *)data) = cpu_to_le16(skb->len - 2);
298 sp = (struct dn_short_packet *)(data+2);
299
300 sp->msgflg = DN_RT_PKT_SHORT|(cb->rt_flags&(DN_RT_F_RQR|DN_RT_F_RTS));
301 sp->dstnode = cb->dst;
302 sp->srcnode = cb->src;
303 sp->forward = cb->hops & 0x3f;
304
305 skb_reset_network_header(skb);
306
307 return NF_HOOK(PF_DECnet, NF_DN_POST_ROUTING, skb, NULL, neigh->dev, dn_neigh_output_packet);
308 }
309
310 /*
311 * Phase 3 output is the same is short output, execpt that
312 * it clears the area bits before transmission.
313 */
dn_phase3_output(struct sk_buff * skb)314 static int dn_phase3_output(struct sk_buff *skb)
315 {
316 struct dst_entry *dst = skb->dst;
317 struct neighbour *neigh = dst->neighbour;
318 struct net_device *dev = neigh->dev;
319 int headroom = dev->hard_header_len + sizeof(struct dn_short_packet) + 2;
320 struct dn_short_packet *sp;
321 unsigned char *data;
322 struct dn_skb_cb *cb = DN_SKB_CB(skb);
323
324 if (skb_headroom(skb) < headroom) {
325 struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom);
326 if (skb2 == NULL) {
327 if (net_ratelimit())
328 printk(KERN_CRIT "dn_phase3_output: no memory\n");
329 kfree_skb(skb);
330 return -ENOBUFS;
331 }
332 kfree_skb(skb);
333 skb = skb2;
334 if (net_ratelimit())
335 printk(KERN_INFO "dn_phase3_output: Increasing headroom\n");
336 }
337
338 data = skb_push(skb, sizeof(struct dn_short_packet) + 2);
339 *((__le16 *)data) = cpu_to_le16(skb->len - 2);
340 sp = (struct dn_short_packet *)(data + 2);
341
342 sp->msgflg = DN_RT_PKT_SHORT|(cb->rt_flags&(DN_RT_F_RQR|DN_RT_F_RTS));
343 sp->dstnode = cb->dst & cpu_to_le16(0x03ff);
344 sp->srcnode = cb->src & cpu_to_le16(0x03ff);
345 sp->forward = cb->hops & 0x3f;
346
347 skb_reset_network_header(skb);
348
349 return NF_HOOK(PF_DECnet, NF_DN_POST_ROUTING, skb, NULL, neigh->dev, dn_neigh_output_packet);
350 }
351
352 /*
353 * Unfortunately, the neighbour code uses the device in its hash
354 * function, so we don't get any advantage from it. This function
355 * basically does a neigh_lookup(), but without comparing the device
356 * field. This is required for the On-Ethernet cache
357 */
358
359 /*
360 * Pointopoint link receives a hello message
361 */
dn_neigh_pointopoint_hello(struct sk_buff * skb)362 void dn_neigh_pointopoint_hello(struct sk_buff *skb)
363 {
364 kfree_skb(skb);
365 }
366
367 /*
368 * Ethernet router hello message received
369 */
dn_neigh_router_hello(struct sk_buff * skb)370 int dn_neigh_router_hello(struct sk_buff *skb)
371 {
372 struct rtnode_hello_message *msg = (struct rtnode_hello_message *)skb->data;
373
374 struct neighbour *neigh;
375 struct dn_neigh *dn;
376 struct dn_dev *dn_db;
377 __le16 src;
378
379 src = dn_eth2dn(msg->id);
380
381 neigh = __neigh_lookup(&dn_neigh_table, &src, skb->dev, 1);
382
383 dn = (struct dn_neigh *)neigh;
384
385 if (neigh) {
386 write_lock(&neigh->lock);
387
388 neigh->used = jiffies;
389 dn_db = (struct dn_dev *)neigh->dev->dn_ptr;
390
391 if (!(neigh->nud_state & NUD_PERMANENT)) {
392 neigh->updated = jiffies;
393
394 if (neigh->dev->type == ARPHRD_ETHER)
395 memcpy(neigh->ha, ð_hdr(skb)->h_source, ETH_ALEN);
396
397 dn->blksize = le16_to_cpu(msg->blksize);
398 dn->priority = msg->priority;
399
400 dn->flags &= ~DN_NDFLAG_P3;
401
402 switch(msg->iinfo & DN_RT_INFO_TYPE) {
403 case DN_RT_INFO_L1RT:
404 dn->flags &=~DN_NDFLAG_R2;
405 dn->flags |= DN_NDFLAG_R1;
406 break;
407 case DN_RT_INFO_L2RT:
408 dn->flags |= DN_NDFLAG_R2;
409 }
410 }
411
412 /* Only use routers in our area */
413 if ((le16_to_cpu(src)>>10) == (le16_to_cpu((decnet_address))>>10)) {
414 if (!dn_db->router) {
415 dn_db->router = neigh_clone(neigh);
416 } else {
417 if (msg->priority > ((struct dn_neigh *)dn_db->router)->priority)
418 neigh_release(xchg(&dn_db->router, neigh_clone(neigh)));
419 }
420 }
421 write_unlock(&neigh->lock);
422 neigh_release(neigh);
423 }
424
425 kfree_skb(skb);
426 return 0;
427 }
428
429 /*
430 * Endnode hello message received
431 */
dn_neigh_endnode_hello(struct sk_buff * skb)432 int dn_neigh_endnode_hello(struct sk_buff *skb)
433 {
434 struct endnode_hello_message *msg = (struct endnode_hello_message *)skb->data;
435 struct neighbour *neigh;
436 struct dn_neigh *dn;
437 __le16 src;
438
439 src = dn_eth2dn(msg->id);
440
441 neigh = __neigh_lookup(&dn_neigh_table, &src, skb->dev, 1);
442
443 dn = (struct dn_neigh *)neigh;
444
445 if (neigh) {
446 write_lock(&neigh->lock);
447
448 neigh->used = jiffies;
449
450 if (!(neigh->nud_state & NUD_PERMANENT)) {
451 neigh->updated = jiffies;
452
453 if (neigh->dev->type == ARPHRD_ETHER)
454 memcpy(neigh->ha, ð_hdr(skb)->h_source, ETH_ALEN);
455 dn->flags &= ~(DN_NDFLAG_R1 | DN_NDFLAG_R2);
456 dn->blksize = le16_to_cpu(msg->blksize);
457 dn->priority = 0;
458 }
459
460 write_unlock(&neigh->lock);
461 neigh_release(neigh);
462 }
463
464 kfree_skb(skb);
465 return 0;
466 }
467
dn_find_slot(char * base,int max,int priority)468 static char *dn_find_slot(char *base, int max, int priority)
469 {
470 int i;
471 unsigned char *min = NULL;
472
473 base += 6; /* skip first id */
474
475 for(i = 0; i < max; i++) {
476 if (!min || (*base < *min))
477 min = base;
478 base += 7; /* find next priority */
479 }
480
481 if (!min)
482 return NULL;
483
484 return (*min < priority) ? (min - 6) : NULL;
485 }
486
487 struct elist_cb_state {
488 struct net_device *dev;
489 unsigned char *ptr;
490 unsigned char *rs;
491 int t, n;
492 };
493
neigh_elist_cb(struct neighbour * neigh,void * _info)494 static void neigh_elist_cb(struct neighbour *neigh, void *_info)
495 {
496 struct elist_cb_state *s = _info;
497 struct dn_neigh *dn;
498
499 if (neigh->dev != s->dev)
500 return;
501
502 dn = (struct dn_neigh *) neigh;
503 if (!(dn->flags & (DN_NDFLAG_R1|DN_NDFLAG_R2)))
504 return;
505
506 if (s->t == s->n)
507 s->rs = dn_find_slot(s->ptr, s->n, dn->priority);
508 else
509 s->t++;
510 if (s->rs == NULL)
511 return;
512
513 dn_dn2eth(s->rs, dn->addr);
514 s->rs += 6;
515 *(s->rs) = neigh->nud_state & NUD_CONNECTED ? 0x80 : 0x0;
516 *(s->rs) |= dn->priority;
517 s->rs++;
518 }
519
dn_neigh_elist(struct net_device * dev,unsigned char * ptr,int n)520 int dn_neigh_elist(struct net_device *dev, unsigned char *ptr, int n)
521 {
522 struct elist_cb_state state;
523
524 state.dev = dev;
525 state.t = 0;
526 state.n = n;
527 state.ptr = ptr;
528 state.rs = ptr;
529
530 neigh_for_each(&dn_neigh_table, neigh_elist_cb, &state);
531
532 return state.t;
533 }
534
535
536 #ifdef CONFIG_PROC_FS
537
dn_neigh_format_entry(struct seq_file * seq,struct neighbour * n)538 static inline void dn_neigh_format_entry(struct seq_file *seq,
539 struct neighbour *n)
540 {
541 struct dn_neigh *dn = (struct dn_neigh *) n;
542 char buf[DN_ASCBUF_LEN];
543
544 read_lock(&n->lock);
545 seq_printf(seq, "%-7s %s%s%s %02x %02d %07ld %-8s\n",
546 dn_addr2asc(le16_to_cpu(dn->addr), buf),
547 (dn->flags&DN_NDFLAG_R1) ? "1" : "-",
548 (dn->flags&DN_NDFLAG_R2) ? "2" : "-",
549 (dn->flags&DN_NDFLAG_P3) ? "3" : "-",
550 dn->n.nud_state,
551 atomic_read(&dn->n.refcnt),
552 dn->blksize,
553 (dn->n.dev) ? dn->n.dev->name : "?");
554 read_unlock(&n->lock);
555 }
556
dn_neigh_seq_show(struct seq_file * seq,void * v)557 static int dn_neigh_seq_show(struct seq_file *seq, void *v)
558 {
559 if (v == SEQ_START_TOKEN) {
560 seq_puts(seq, "Addr Flags State Use Blksize Dev\n");
561 } else {
562 dn_neigh_format_entry(seq, v);
563 }
564
565 return 0;
566 }
567
dn_neigh_seq_start(struct seq_file * seq,loff_t * pos)568 static void *dn_neigh_seq_start(struct seq_file *seq, loff_t *pos)
569 {
570 return neigh_seq_start(seq, pos, &dn_neigh_table,
571 NEIGH_SEQ_NEIGH_ONLY);
572 }
573
574 static const struct seq_operations dn_neigh_seq_ops = {
575 .start = dn_neigh_seq_start,
576 .next = neigh_seq_next,
577 .stop = neigh_seq_stop,
578 .show = dn_neigh_seq_show,
579 };
580
dn_neigh_seq_open(struct inode * inode,struct file * file)581 static int dn_neigh_seq_open(struct inode *inode, struct file *file)
582 {
583 return seq_open_net(inode, file, &dn_neigh_seq_ops,
584 sizeof(struct neigh_seq_state));
585 }
586
587 static const struct file_operations dn_neigh_seq_fops = {
588 .owner = THIS_MODULE,
589 .open = dn_neigh_seq_open,
590 .read = seq_read,
591 .llseek = seq_lseek,
592 .release = seq_release_net,
593 };
594
595 #endif
596
dn_neigh_init(void)597 void __init dn_neigh_init(void)
598 {
599 neigh_table_init(&dn_neigh_table);
600 proc_net_fops_create(&init_net, "decnet_neigh", S_IRUGO, &dn_neigh_seq_fops);
601 }
602
dn_neigh_cleanup(void)603 void __exit dn_neigh_cleanup(void)
604 {
605 proc_net_remove(&init_net, "decnet_neigh");
606 neigh_table_clear(&dn_neigh_table);
607 }
608