neigh: Pass neighbour entry to output ops.
[linux-3.10.git] / net / decnet / dn_neigh.c
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 <asm/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
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);
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 =            3,
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
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
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
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
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->neighbour;
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
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
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  */
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  */
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  */
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, &eth_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  */
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, &eth_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
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
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
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
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
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
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
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
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
596 void __exit dn_neigh_cleanup(void)
597 {
598         proc_net_remove(&init_net, "decnet_neigh");
599         neigh_table_clear(&dn_neigh_table);
600 }