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