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
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 neighbour *, struct sk_buff *);
55 static int dn_short_output(struct neighbour *, struct sk_buff *);
56 static int dn_phase3_output(struct neighbour *, struct sk_buff *);
57
58
59 /*
60 * For talking to broadcast devices: Ethernet & PPP
61 */
62 static const 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 };
68
69 /*
70 * For talking to pointopoint and multidrop devices: DDCMP and X.25
71 */
72 static const struct neigh_ops dn_short_ops = {
73 .family = AF_DECnet,
74 .error_report = dn_short_error_report,
75 .output = dn_short_output,
76 .connected_output = dn_short_output,
77 };
78
79 /*
80 * For talking to DECnet phase III nodes
81 */
82 static const struct neigh_ops dn_phase3_ops = {
83 .family = AF_DECnet,
84 .error_report = dn_short_error_report, /* Can use short version here */
85 .output = dn_phase3_output,
86 .connected_output = dn_phase3_output,
87 };
88
dn_neigh_hash(const void * pkey,const struct net_device * dev,__u32 * hash_rnd)89 static u32 dn_neigh_hash(const void *pkey,
90 const struct net_device *dev,
91 __u32 *hash_rnd)
92 {
93 return jhash_2words(*(__u16 *)pkey, 0, hash_rnd[0]);
94 }
95
96 struct neigh_table dn_neigh_table = {
97 .family = PF_DECnet,
98 .entry_size = sizeof(struct dn_neigh),
99 .key_len = sizeof(__le16),
100 .hash = dn_neigh_hash,
101 .constructor = dn_neigh_construct,
102 .id = "dn_neigh_cache",
103 .parms ={
104 .tbl = &dn_neigh_table,
105 .base_reachable_time = 30 * HZ,
106 .retrans_time = 1 * HZ,
107 .gc_staletime = 60 * HZ,
108 .reachable_time = 30 * HZ,
109 .delay_probe_time = 5 * HZ,
110 .queue_len_bytes = 64*1024,
111 .ucast_probes = 0,
112 .app_probes = 0,
113 .mcast_probes = 0,
114 .anycast_delay = 0,
115 .proxy_delay = 0,
116 .proxy_qlen = 0,
117 .locktime = 1 * HZ,
118 },
119 .gc_interval = 30 * HZ,
120 .gc_thresh1 = 128,
121 .gc_thresh2 = 512,
122 .gc_thresh3 = 1024,
123 };
124
dn_neigh_construct(struct neighbour * neigh)125 static int dn_neigh_construct(struct neighbour *neigh)
126 {
127 struct net_device *dev = neigh->dev;
128 struct dn_neigh *dn = (struct dn_neigh *)neigh;
129 struct dn_dev *dn_db;
130 struct neigh_parms *parms;
131
132 rcu_read_lock();
133 dn_db = rcu_dereference(dev->dn_ptr);
134 if (dn_db == NULL) {
135 rcu_read_unlock();
136 return -EINVAL;
137 }
138
139 parms = dn_db->neigh_parms;
140 if (!parms) {
141 rcu_read_unlock();
142 return -EINVAL;
143 }
144
145 __neigh_parms_put(neigh->parms);
146 neigh->parms = neigh_parms_clone(parms);
147
148 if (dn_db->use_long)
149 neigh->ops = &dn_long_ops;
150 else
151 neigh->ops = &dn_short_ops;
152 rcu_read_unlock();
153
154 if (dn->flags & DN_NDFLAG_P3)
155 neigh->ops = &dn_phase3_ops;
156
157 neigh->nud_state = NUD_NOARP;
158 neigh->output = neigh->ops->connected_output;
159
160 if ((dev->type == ARPHRD_IPGRE) || (dev->flags & IFF_POINTOPOINT))
161 memcpy(neigh->ha, dev->broadcast, dev->addr_len);
162 else if ((dev->type == ARPHRD_ETHER) || (dev->type == ARPHRD_LOOPBACK))
163 dn_dn2eth(neigh->ha, dn->addr);
164 else {
165 if (net_ratelimit())
166 printk(KERN_DEBUG "Trying to create neigh for hw %d\n", dev->type);
167 return -EINVAL;
168 }
169
170 /*
171 * Make an estimate of the remote block size by assuming that its
172 * two less then the device mtu, which it true for ethernet (and
173 * other things which support long format headers) since there is
174 * an extra length field (of 16 bits) which isn't part of the
175 * ethernet headers and which the DECnet specs won't admit is part
176 * of the DECnet routing headers either.
177 *
178 * If we over estimate here its no big deal, the NSP negotiations
179 * will prevent us from sending packets which are too large for the
180 * remote node to handle. In any case this figure is normally updated
181 * by a hello message in most cases.
182 */
183 dn->blksize = dev->mtu - 2;
184
185 return 0;
186 }
187
dn_long_error_report(struct neighbour * neigh,struct sk_buff * skb)188 static void dn_long_error_report(struct neighbour *neigh, struct sk_buff *skb)
189 {
190 printk(KERN_DEBUG "dn_long_error_report: called\n");
191 kfree_skb(skb);
192 }
193
194
dn_short_error_report(struct neighbour * neigh,struct sk_buff * skb)195 static void dn_short_error_report(struct neighbour *neigh, struct sk_buff *skb)
196 {
197 printk(KERN_DEBUG "dn_short_error_report: called\n");
198 kfree_skb(skb);
199 }
200
dn_neigh_output_packet(struct sk_buff * skb)201 static int dn_neigh_output_packet(struct sk_buff *skb)
202 {
203 struct dst_entry *dst = skb_dst(skb);
204 struct dn_route *rt = (struct dn_route *)dst;
205 struct neighbour *neigh = dst_get_neighbour_noref(dst);
206 struct net_device *dev = neigh->dev;
207 char mac_addr[ETH_ALEN];
208
209 dn_dn2eth(mac_addr, rt->rt_local_src);
210 if (dev_hard_header(skb, dev, ntohs(skb->protocol), neigh->ha,
211 mac_addr, skb->len) >= 0)
212 return dev_queue_xmit(skb);
213
214 if (net_ratelimit())
215 printk(KERN_DEBUG "dn_neigh_output_packet: oops, can't send packet\n");
216
217 kfree_skb(skb);
218 return -EINVAL;
219 }
220
dn_long_output(struct neighbour * neigh,struct sk_buff * skb)221 static int dn_long_output(struct neighbour *neigh, struct sk_buff *skb)
222 {
223 struct net_device *dev = neigh->dev;
224 int headroom = dev->hard_header_len + sizeof(struct dn_long_packet) + 3;
225 unsigned char *data;
226 struct dn_long_packet *lp;
227 struct dn_skb_cb *cb = DN_SKB_CB(skb);
228
229
230 if (skb_headroom(skb) < headroom) {
231 struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom);
232 if (skb2 == NULL) {
233 if (net_ratelimit())
234 printk(KERN_CRIT "dn_long_output: no memory\n");
235 kfree_skb(skb);
236 return -ENOBUFS;
237 }
238 kfree_skb(skb);
239 skb = skb2;
240 if (net_ratelimit())
241 printk(KERN_INFO "dn_long_output: Increasing headroom\n");
242 }
243
244 data = skb_push(skb, sizeof(struct dn_long_packet) + 3);
245 lp = (struct dn_long_packet *)(data+3);
246
247 *((__le16 *)data) = cpu_to_le16(skb->len - 2);
248 *(data + 2) = 1 | DN_RT_F_PF; /* Padding */
249
250 lp->msgflg = DN_RT_PKT_LONG|(cb->rt_flags&(DN_RT_F_IE|DN_RT_F_RQR|DN_RT_F_RTS));
251 lp->d_area = lp->d_subarea = 0;
252 dn_dn2eth(lp->d_id, cb->dst);
253 lp->s_area = lp->s_subarea = 0;
254 dn_dn2eth(lp->s_id, cb->src);
255 lp->nl2 = 0;
256 lp->visit_ct = cb->hops & 0x3f;
257 lp->s_class = 0;
258 lp->pt = 0;
259
260 skb_reset_network_header(skb);
261
262 return NF_HOOK(NFPROTO_DECNET, NF_DN_POST_ROUTING, skb, NULL,
263 neigh->dev, dn_neigh_output_packet);
264 }
265
dn_short_output(struct neighbour * neigh,struct sk_buff * skb)266 static int dn_short_output(struct neighbour *neigh, struct sk_buff *skb)
267 {
268 struct net_device *dev = neigh->dev;
269 int headroom = dev->hard_header_len + sizeof(struct dn_short_packet) + 2;
270 struct dn_short_packet *sp;
271 unsigned char *data;
272 struct dn_skb_cb *cb = DN_SKB_CB(skb);
273
274
275 if (skb_headroom(skb) < headroom) {
276 struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom);
277 if (skb2 == NULL) {
278 if (net_ratelimit())
279 printk(KERN_CRIT "dn_short_output: no memory\n");
280 kfree_skb(skb);
281 return -ENOBUFS;
282 }
283 kfree_skb(skb);
284 skb = skb2;
285 if (net_ratelimit())
286 printk(KERN_INFO "dn_short_output: Increasing headroom\n");
287 }
288
289 data = skb_push(skb, sizeof(struct dn_short_packet) + 2);
290 *((__le16 *)data) = cpu_to_le16(skb->len - 2);
291 sp = (struct dn_short_packet *)(data+2);
292
293 sp->msgflg = DN_RT_PKT_SHORT|(cb->rt_flags&(DN_RT_F_RQR|DN_RT_F_RTS));
294 sp->dstnode = cb->dst;
295 sp->srcnode = cb->src;
296 sp->forward = cb->hops & 0x3f;
297
298 skb_reset_network_header(skb);
299
300 return NF_HOOK(NFPROTO_DECNET, NF_DN_POST_ROUTING, skb, NULL,
301 neigh->dev, dn_neigh_output_packet);
302 }
303
304 /*
305 * Phase 3 output is the same is short output, execpt that
306 * it clears the area bits before transmission.
307 */
dn_phase3_output(struct neighbour * neigh,struct sk_buff * skb)308 static int dn_phase3_output(struct neighbour *neigh, struct sk_buff *skb)
309 {
310 struct net_device *dev = neigh->dev;
311 int headroom = dev->hard_header_len + sizeof(struct dn_short_packet) + 2;
312 struct dn_short_packet *sp;
313 unsigned char *data;
314 struct dn_skb_cb *cb = DN_SKB_CB(skb);
315
316 if (skb_headroom(skb) < headroom) {
317 struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom);
318 if (skb2 == NULL) {
319 if (net_ratelimit())
320 printk(KERN_CRIT "dn_phase3_output: no memory\n");
321 kfree_skb(skb);
322 return -ENOBUFS;
323 }
324 kfree_skb(skb);
325 skb = skb2;
326 if (net_ratelimit())
327 printk(KERN_INFO "dn_phase3_output: Increasing headroom\n");
328 }
329
330 data = skb_push(skb, sizeof(struct dn_short_packet) + 2);
331 *((__le16 *)data) = cpu_to_le16(skb->len - 2);
332 sp = (struct dn_short_packet *)(data + 2);
333
334 sp->msgflg = DN_RT_PKT_SHORT|(cb->rt_flags&(DN_RT_F_RQR|DN_RT_F_RTS));
335 sp->dstnode = cb->dst & cpu_to_le16(0x03ff);
336 sp->srcnode = cb->src & cpu_to_le16(0x03ff);
337 sp->forward = cb->hops & 0x3f;
338
339 skb_reset_network_header(skb);
340
341 return NF_HOOK(NFPROTO_DECNET, NF_DN_POST_ROUTING, skb, NULL,
342 neigh->dev, dn_neigh_output_packet);
343 }
344
345 /*
346 * Unfortunately, the neighbour code uses the device in its hash
347 * function, so we don't get any advantage from it. This function
348 * basically does a neigh_lookup(), but without comparing the device
349 * field. This is required for the On-Ethernet cache
350 */
351
352 /*
353 * Pointopoint link receives a hello message
354 */
dn_neigh_pointopoint_hello(struct sk_buff * skb)355 void dn_neigh_pointopoint_hello(struct sk_buff *skb)
356 {
357 kfree_skb(skb);
358 }
359
360 /*
361 * Ethernet router hello message received
362 */
dn_neigh_router_hello(struct sk_buff * skb)363 int dn_neigh_router_hello(struct sk_buff *skb)
364 {
365 struct rtnode_hello_message *msg = (struct rtnode_hello_message *)skb->data;
366
367 struct neighbour *neigh;
368 struct dn_neigh *dn;
369 struct dn_dev *dn_db;
370 __le16 src;
371
372 src = dn_eth2dn(msg->id);
373
374 neigh = __neigh_lookup(&dn_neigh_table, &src, skb->dev, 1);
375
376 dn = (struct dn_neigh *)neigh;
377
378 if (neigh) {
379 write_lock(&neigh->lock);
380
381 neigh->used = jiffies;
382 dn_db = rcu_dereference(neigh->dev->dn_ptr);
383
384 if (!(neigh->nud_state & NUD_PERMANENT)) {
385 neigh->updated = jiffies;
386
387 if (neigh->dev->type == ARPHRD_ETHER)
388 memcpy(neigh->ha, ð_hdr(skb)->h_source, ETH_ALEN);
389
390 dn->blksize = le16_to_cpu(msg->blksize);
391 dn->priority = msg->priority;
392
393 dn->flags &= ~DN_NDFLAG_P3;
394
395 switch (msg->iinfo & DN_RT_INFO_TYPE) {
396 case DN_RT_INFO_L1RT:
397 dn->flags &=~DN_NDFLAG_R2;
398 dn->flags |= DN_NDFLAG_R1;
399 break;
400 case DN_RT_INFO_L2RT:
401 dn->flags |= DN_NDFLAG_R2;
402 }
403 }
404
405 /* Only use routers in our area */
406 if ((le16_to_cpu(src)>>10) == (le16_to_cpu((decnet_address))>>10)) {
407 if (!dn_db->router) {
408 dn_db->router = neigh_clone(neigh);
409 } else {
410 if (msg->priority > ((struct dn_neigh *)dn_db->router)->priority)
411 neigh_release(xchg(&dn_db->router, neigh_clone(neigh)));
412 }
413 }
414 write_unlock(&neigh->lock);
415 neigh_release(neigh);
416 }
417
418 kfree_skb(skb);
419 return 0;
420 }
421
422 /*
423 * Endnode hello message received
424 */
dn_neigh_endnode_hello(struct sk_buff * skb)425 int dn_neigh_endnode_hello(struct sk_buff *skb)
426 {
427 struct endnode_hello_message *msg = (struct endnode_hello_message *)skb->data;
428 struct neighbour *neigh;
429 struct dn_neigh *dn;
430 __le16 src;
431
432 src = dn_eth2dn(msg->id);
433
434 neigh = __neigh_lookup(&dn_neigh_table, &src, skb->dev, 1);
435
436 dn = (struct dn_neigh *)neigh;
437
438 if (neigh) {
439 write_lock(&neigh->lock);
440
441 neigh->used = jiffies;
442
443 if (!(neigh->nud_state & NUD_PERMANENT)) {
444 neigh->updated = jiffies;
445
446 if (neigh->dev->type == ARPHRD_ETHER)
447 memcpy(neigh->ha, ð_hdr(skb)->h_source, ETH_ALEN);
448 dn->flags &= ~(DN_NDFLAG_R1 | DN_NDFLAG_R2);
449 dn->blksize = le16_to_cpu(msg->blksize);
450 dn->priority = 0;
451 }
452
453 write_unlock(&neigh->lock);
454 neigh_release(neigh);
455 }
456
457 kfree_skb(skb);
458 return 0;
459 }
460
dn_find_slot(char * base,int max,int priority)461 static char *dn_find_slot(char *base, int max, int priority)
462 {
463 int i;
464 unsigned char *min = NULL;
465
466 base += 6; /* skip first id */
467
468 for(i = 0; i < max; i++) {
469 if (!min || (*base < *min))
470 min = base;
471 base += 7; /* find next priority */
472 }
473
474 if (!min)
475 return NULL;
476
477 return (*min < priority) ? (min - 6) : NULL;
478 }
479
480 struct elist_cb_state {
481 struct net_device *dev;
482 unsigned char *ptr;
483 unsigned char *rs;
484 int t, n;
485 };
486
neigh_elist_cb(struct neighbour * neigh,void * _info)487 static void neigh_elist_cb(struct neighbour *neigh, void *_info)
488 {
489 struct elist_cb_state *s = _info;
490 struct dn_neigh *dn;
491
492 if (neigh->dev != s->dev)
493 return;
494
495 dn = (struct dn_neigh *) neigh;
496 if (!(dn->flags & (DN_NDFLAG_R1|DN_NDFLAG_R2)))
497 return;
498
499 if (s->t == s->n)
500 s->rs = dn_find_slot(s->ptr, s->n, dn->priority);
501 else
502 s->t++;
503 if (s->rs == NULL)
504 return;
505
506 dn_dn2eth(s->rs, dn->addr);
507 s->rs += 6;
508 *(s->rs) = neigh->nud_state & NUD_CONNECTED ? 0x80 : 0x0;
509 *(s->rs) |= dn->priority;
510 s->rs++;
511 }
512
dn_neigh_elist(struct net_device * dev,unsigned char * ptr,int n)513 int dn_neigh_elist(struct net_device *dev, unsigned char *ptr, int n)
514 {
515 struct elist_cb_state state;
516
517 state.dev = dev;
518 state.t = 0;
519 state.n = n;
520 state.ptr = ptr;
521 state.rs = ptr;
522
523 neigh_for_each(&dn_neigh_table, neigh_elist_cb, &state);
524
525 return state.t;
526 }
527
528
529 #ifdef CONFIG_PROC_FS
530
dn_neigh_format_entry(struct seq_file * seq,struct neighbour * n)531 static inline void dn_neigh_format_entry(struct seq_file *seq,
532 struct neighbour *n)
533 {
534 struct dn_neigh *dn = (struct dn_neigh *) n;
535 char buf[DN_ASCBUF_LEN];
536
537 read_lock(&n->lock);
538 seq_printf(seq, "%-7s %s%s%s %02x %02d %07ld %-8s\n",
539 dn_addr2asc(le16_to_cpu(dn->addr), buf),
540 (dn->flags&DN_NDFLAG_R1) ? "1" : "-",
541 (dn->flags&DN_NDFLAG_R2) ? "2" : "-",
542 (dn->flags&DN_NDFLAG_P3) ? "3" : "-",
543 dn->n.nud_state,
544 atomic_read(&dn->n.refcnt),
545 dn->blksize,
546 (dn->n.dev) ? dn->n.dev->name : "?");
547 read_unlock(&n->lock);
548 }
549
dn_neigh_seq_show(struct seq_file * seq,void * v)550 static int dn_neigh_seq_show(struct seq_file *seq, void *v)
551 {
552 if (v == SEQ_START_TOKEN) {
553 seq_puts(seq, "Addr Flags State Use Blksize Dev\n");
554 } else {
555 dn_neigh_format_entry(seq, v);
556 }
557
558 return 0;
559 }
560
dn_neigh_seq_start(struct seq_file * seq,loff_t * pos)561 static void *dn_neigh_seq_start(struct seq_file *seq, loff_t *pos)
562 {
563 return neigh_seq_start(seq, pos, &dn_neigh_table,
564 NEIGH_SEQ_NEIGH_ONLY);
565 }
566
567 static const struct seq_operations dn_neigh_seq_ops = {
568 .start = dn_neigh_seq_start,
569 .next = neigh_seq_next,
570 .stop = neigh_seq_stop,
571 .show = dn_neigh_seq_show,
572 };
573
dn_neigh_seq_open(struct inode * inode,struct file * file)574 static int dn_neigh_seq_open(struct inode *inode, struct file *file)
575 {
576 return seq_open_net(inode, file, &dn_neigh_seq_ops,
577 sizeof(struct neigh_seq_state));
578 }
579
580 static const struct file_operations dn_neigh_seq_fops = {
581 .owner = THIS_MODULE,
582 .open = dn_neigh_seq_open,
583 .read = seq_read,
584 .llseek = seq_lseek,
585 .release = seq_release_net,
586 };
587
588 #endif
589
dn_neigh_init(void)590 void __init dn_neigh_init(void)
591 {
592 neigh_table_init(&dn_neigh_table);
593 proc_net_fops_create(&init_net, "decnet_neigh", S_IRUGO, &dn_neigh_seq_fops);
594 }
595
dn_neigh_cleanup(void)596 void __exit dn_neigh_cleanup(void)
597 {
598 proc_net_remove(&init_net, "decnet_neigh");
599 neigh_table_clear(&dn_neigh_table);
600 }
601