[NET]: Transform skb_queue_len() binary tests into skb_queue_empty()
[linux-2.6.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/config.h>
28 #include <linux/net.h>
29 #include <linux/module.h>
30 #include <linux/socket.h>
31 #include <linux/if_arp.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/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(dn_address),
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
124 static u32 dn_neigh_hash(const void *pkey, const struct net_device *dev)
125 {
126         return jhash_2words(*(dn_address *)pkey, 0, dn_neigh_table.hash_rnd);
127 }
128
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         rcu_read_unlock();
152
153         if (dn_db->use_long)
154                 neigh->ops = &dn_long_ops;
155         else
156                 neigh->ops = &dn_short_ops;
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
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
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
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 || dev->hard_header(skb, dev, ntohs(skb->protocol), neigh->ha, mac_addr, skb->len) >= 0)
215                 return neigh->ops->queue_xmit(skb);
216
217         if (net_ratelimit())
218                 printk(KERN_DEBUG "dn_neigh_output_packet: oops, can't send packet\n");
219
220         kfree_skb(skb);
221         return -EINVAL;
222 }
223
224 static int dn_long_output(struct sk_buff *skb)
225 {
226         struct dst_entry *dst = skb->dst;
227         struct neighbour *neigh = dst->neighbour;
228         struct net_device *dev = neigh->dev;
229         int headroom = dev->hard_header_len + sizeof(struct dn_long_packet) + 3;
230         unsigned char *data;
231         struct dn_long_packet *lp;
232         struct dn_skb_cb *cb = DN_SKB_CB(skb);
233
234
235         if (skb_headroom(skb) < headroom) {
236                 struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom);
237                 if (skb2 == NULL) {
238                         if (net_ratelimit())
239                                 printk(KERN_CRIT "dn_long_output: no memory\n");
240                         kfree_skb(skb);
241                         return -ENOBUFS;
242                 }
243                 kfree_skb(skb);
244                 skb = skb2;
245                 if (net_ratelimit())
246                         printk(KERN_INFO "dn_long_output: Increasing headroom\n");
247         }
248
249         data = skb_push(skb, sizeof(struct dn_long_packet) + 3);
250         lp = (struct dn_long_packet *)(data+3);
251
252         *((unsigned short *)data) = dn_htons(skb->len - 2);
253         *(data + 2) = 1 | DN_RT_F_PF; /* Padding */
254
255         lp->msgflg   = DN_RT_PKT_LONG|(cb->rt_flags&(DN_RT_F_IE|DN_RT_F_RQR|DN_RT_F_RTS));
256         lp->d_area   = lp->d_subarea = 0;
257         dn_dn2eth(lp->d_id, dn_ntohs(cb->dst));
258         lp->s_area   = lp->s_subarea = 0;
259         dn_dn2eth(lp->s_id, dn_ntohs(cb->src));
260         lp->nl2      = 0;
261         lp->visit_ct = cb->hops & 0x3f;
262         lp->s_class  = 0;
263         lp->pt       = 0;
264
265         skb->nh.raw = skb->data;
266
267         return NF_HOOK(PF_DECnet, NF_DN_POST_ROUTING, skb, NULL, neigh->dev, dn_neigh_output_packet);
268 }
269
270 static int dn_short_output(struct sk_buff *skb)
271 {
272         struct dst_entry *dst = skb->dst;
273         struct neighbour *neigh = dst->neighbour;
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                         if (net_ratelimit())
285                                 printk(KERN_CRIT "dn_short_output: no memory\n");
286                         kfree_skb(skb);
287                         return -ENOBUFS;
288                 }
289                 kfree_skb(skb);
290                 skb = skb2;
291                 if (net_ratelimit())
292                         printk(KERN_INFO "dn_short_output: Increasing headroom\n");
293         }
294
295         data = skb_push(skb, sizeof(struct dn_short_packet) + 2);
296         *((unsigned short *)data) = dn_htons(skb->len - 2);
297         sp = (struct dn_short_packet *)(data+2);
298
299         sp->msgflg     = DN_RT_PKT_SHORT|(cb->rt_flags&(DN_RT_F_RQR|DN_RT_F_RTS));
300         sp->dstnode    = cb->dst;
301         sp->srcnode    = cb->src;
302         sp->forward    = cb->hops & 0x3f;
303
304         skb->nh.raw = skb->data;
305
306         return NF_HOOK(PF_DECnet, NF_DN_POST_ROUTING, skb, NULL, neigh->dev, dn_neigh_output_packet);
307 }
308
309 /*
310  * Phase 3 output is the same is short output, execpt that
311  * it clears the area bits before transmission.
312  */
313 static int dn_phase3_output(struct sk_buff *skb)
314 {
315         struct dst_entry *dst = skb->dst;
316         struct neighbour *neigh = dst->neighbour;
317         struct net_device *dev = neigh->dev;
318         int headroom = dev->hard_header_len + sizeof(struct dn_short_packet) + 2;
319         struct dn_short_packet *sp;
320         unsigned char *data;
321         struct dn_skb_cb *cb = DN_SKB_CB(skb);
322
323         if (skb_headroom(skb) < headroom) {
324                 struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom);
325                 if (skb2 == NULL) {
326                         if (net_ratelimit())
327                                 printk(KERN_CRIT "dn_phase3_output: no memory\n");
328                         kfree_skb(skb);
329                         return -ENOBUFS;
330                 }
331                 kfree_skb(skb);
332                 skb = skb2;
333                 if (net_ratelimit())
334                         printk(KERN_INFO "dn_phase3_output: Increasing headroom\n");
335         }
336
337         data = skb_push(skb, sizeof(struct dn_short_packet) + 2);
338         *((unsigned short *)data) = dn_htons(skb->len - 2);
339         sp = (struct dn_short_packet *)(data + 2);
340
341         sp->msgflg   = DN_RT_PKT_SHORT|(cb->rt_flags&(DN_RT_F_RQR|DN_RT_F_RTS));
342         sp->dstnode  = cb->dst & dn_htons(0x03ff);
343         sp->srcnode  = cb->src & dn_htons(0x03ff);
344         sp->forward  = cb->hops & 0x3f;
345
346         skb->nh.raw = skb->data;
347
348         return NF_HOOK(PF_DECnet, NF_DN_POST_ROUTING, skb, NULL, neigh->dev, dn_neigh_output_packet);
349 }
350
351 /*
352  * Unfortunately, the neighbour code uses the device in its hash
353  * function, so we don't get any advantage from it. This function
354  * basically does a neigh_lookup(), but without comparing the device
355  * field. This is required for the On-Ethernet cache
356  */
357
358 /*
359  * Pointopoint link receives a hello message
360  */
361 void dn_neigh_pointopoint_hello(struct sk_buff *skb)
362 {
363         kfree_skb(skb);
364 }
365
366 /*
367  * Ethernet router hello message received
368  */
369 int dn_neigh_router_hello(struct sk_buff *skb)
370 {
371         struct rtnode_hello_message *msg = (struct rtnode_hello_message *)skb->data;
372
373         struct neighbour *neigh;
374         struct dn_neigh *dn;
375         struct dn_dev *dn_db;
376         dn_address src;
377
378         src = dn_htons(dn_eth2dn(msg->id));
379
380         neigh = __neigh_lookup(&dn_neigh_table, &src, skb->dev, 1);
381
382         dn = (struct dn_neigh *)neigh;
383
384         if (neigh) {
385                 write_lock(&neigh->lock);
386
387                 neigh->used = jiffies;
388                 dn_db = (struct dn_dev *)neigh->dev->dn_ptr;
389
390                 if (!(neigh->nud_state & NUD_PERMANENT)) {
391                         neigh->updated = jiffies;
392
393                         if (neigh->dev->type == ARPHRD_ETHER)
394                                 memcpy(neigh->ha, &eth_hdr(skb)->h_source, ETH_ALEN);
395
396                         dn->blksize  = dn_ntohs(msg->blksize);
397                         dn->priority = msg->priority;
398
399                         dn->flags &= ~DN_NDFLAG_P3;
400
401                         switch(msg->iinfo & DN_RT_INFO_TYPE) {
402                                 case DN_RT_INFO_L1RT:
403                                         dn->flags &=~DN_NDFLAG_R2;
404                                         dn->flags |= DN_NDFLAG_R1;
405                                         break;
406                                 case DN_RT_INFO_L2RT:
407                                         dn->flags |= DN_NDFLAG_R2;
408                         }
409                 }
410
411                 if (!dn_db->router) {
412                         dn_db->router = neigh_clone(neigh);
413                 } else {
414                         if (msg->priority > ((struct dn_neigh *)dn_db->router)->priority)
415                                 neigh_release(xchg(&dn_db->router, neigh_clone(neigh)));
416                 }
417                 write_unlock(&neigh->lock);
418                 neigh_release(neigh);
419         }
420
421         kfree_skb(skb);
422         return 0;
423 }
424
425 /*
426  * Endnode hello message received
427  */
428 int dn_neigh_endnode_hello(struct sk_buff *skb)
429 {
430         struct endnode_hello_message *msg = (struct endnode_hello_message *)skb->data;
431         struct neighbour *neigh;
432         struct dn_neigh *dn;
433         dn_address src;
434
435         src = dn_htons(dn_eth2dn(msg->id));
436
437         neigh = __neigh_lookup(&dn_neigh_table, &src, skb->dev, 1);
438
439         dn = (struct dn_neigh *)neigh;
440
441         if (neigh) {
442                 write_lock(&neigh->lock);
443
444                 neigh->used = jiffies;
445
446                 if (!(neigh->nud_state & NUD_PERMANENT)) {
447                         neigh->updated = jiffies;
448
449                         if (neigh->dev->type == ARPHRD_ETHER)
450                                 memcpy(neigh->ha, &eth_hdr(skb)->h_source, ETH_ALEN);
451                         dn->flags   &= ~(DN_NDFLAG_R1 | DN_NDFLAG_R2);
452                         dn->blksize  = dn_ntohs(msg->blksize);
453                         dn->priority = 0;
454                 }
455
456                 write_unlock(&neigh->lock);
457                 neigh_release(neigh);
458         }
459
460         kfree_skb(skb);
461         return 0;
462 }
463
464 static char *dn_find_slot(char *base, int max, int priority)
465 {
466         int i;
467         unsigned char *min = NULL;
468
469         base += 6; /* skip first id */
470
471         for(i = 0; i < max; i++) {
472                 if (!min || (*base < *min))
473                         min = base;
474                 base += 7; /* find next priority */
475         }
476
477         if (!min)
478                 return NULL;
479
480         return (*min < priority) ? (min - 6) : NULL;
481 }
482
483 struct elist_cb_state {
484         struct net_device *dev;
485         unsigned char *ptr;
486         unsigned char *rs;
487         int t, n;
488 };
489
490 static void neigh_elist_cb(struct neighbour *neigh, void *_info)
491 {
492         struct elist_cb_state *s = _info;
493         struct dn_dev *dn_db;
494         struct dn_neigh *dn;
495
496         if (neigh->dev != s->dev)
497                 return;
498
499         dn = (struct dn_neigh *) neigh;
500         if (!(dn->flags & (DN_NDFLAG_R1|DN_NDFLAG_R2)))
501                 return;
502
503         dn_db = (struct dn_dev *) s->dev->dn_ptr;
504         if (dn_db->parms.forwarding == 1 && (dn->flags & DN_NDFLAG_R2))
505                 return;
506
507         if (s->t == s->n)
508                 s->rs = dn_find_slot(s->ptr, s->n, dn->priority);
509         else
510                 s->t++;
511         if (s->rs == NULL)
512                 return;
513
514         dn_dn2eth(s->rs, dn->addr);
515         s->rs += 6;
516         *(s->rs) = neigh->nud_state & NUD_CONNECTED ? 0x80 : 0x0;
517         *(s->rs) |= dn->priority;
518         s->rs++;
519 }
520
521 int dn_neigh_elist(struct net_device *dev, unsigned char *ptr, int n)
522 {
523         struct elist_cb_state state;
524
525         state.dev = dev;
526         state.t = 0;
527         state.n = n;
528         state.ptr = ptr;
529         state.rs = ptr;
530
531         neigh_for_each(&dn_neigh_table, neigh_elist_cb, &state);
532
533         return state.t;
534 }
535
536
537 #ifdef CONFIG_PROC_FS
538
539 static inline void dn_neigh_format_entry(struct seq_file *seq,
540                                          struct neighbour *n)
541 {
542         struct dn_neigh *dn = (struct dn_neigh *) n;
543         char buf[DN_ASCBUF_LEN];
544
545         read_lock(&n->lock);
546         seq_printf(seq, "%-7s %s%s%s   %02x    %02d  %07ld %-8s\n",
547                    dn_addr2asc(dn_ntohs(dn->addr), buf),
548                    (dn->flags&DN_NDFLAG_R1) ? "1" : "-",
549                    (dn->flags&DN_NDFLAG_R2) ? "2" : "-",
550                    (dn->flags&DN_NDFLAG_P3) ? "3" : "-",
551                    dn->n.nud_state,
552                    atomic_read(&dn->n.refcnt),
553                    dn->blksize,
554                    (dn->n.dev) ? dn->n.dev->name : "?");
555         read_unlock(&n->lock);
556 }
557
558 static int dn_neigh_seq_show(struct seq_file *seq, void *v)
559 {
560         if (v == SEQ_START_TOKEN) {
561                 seq_puts(seq, "Addr    Flags State Use Blksize Dev\n");
562         } else {
563                 dn_neigh_format_entry(seq, v);
564         }
565
566         return 0;
567 }
568
569 static void *dn_neigh_seq_start(struct seq_file *seq, loff_t *pos)
570 {
571         return neigh_seq_start(seq, pos, &dn_neigh_table,
572                                NEIGH_SEQ_NEIGH_ONLY);
573 }
574
575 static struct seq_operations dn_neigh_seq_ops = {
576         .start = dn_neigh_seq_start,
577         .next  = neigh_seq_next,
578         .stop  = neigh_seq_stop,
579         .show  = dn_neigh_seq_show,
580 };
581
582 static int dn_neigh_seq_open(struct inode *inode, struct file *file)
583 {
584         struct seq_file *seq;
585         int rc = -ENOMEM;
586         struct neigh_seq_state *s = kmalloc(sizeof(*s), GFP_KERNEL);
587
588         if (!s)
589                 goto out;
590
591         memset(s, 0, sizeof(*s));
592         rc = seq_open(file, &dn_neigh_seq_ops);
593         if (rc)
594                 goto out_kfree;
595
596         seq          = file->private_data;
597         seq->private = s;
598         memset(s, 0, sizeof(*s));
599 out:
600         return rc;
601 out_kfree:
602         kfree(s);
603         goto out;
604 }
605
606 static struct file_operations dn_neigh_seq_fops = {
607         .owner          = THIS_MODULE,
608         .open           = dn_neigh_seq_open,
609         .read           = seq_read,
610         .llseek         = seq_lseek,
611         .release        = seq_release_private,
612 };
613
614 #endif
615
616 void __init dn_neigh_init(void)
617 {
618         neigh_table_init(&dn_neigh_table);
619         proc_net_fops_create("decnet_neigh", S_IRUGO, &dn_neigh_seq_fops);
620 }
621
622 void __exit dn_neigh_cleanup(void)
623 {
624         proc_net_remove("decnet_neigh");
625         neigh_table_clear(&dn_neigh_table);
626 }