e926c952e3632617812e1c1d3eec192cfe2dfeda
[linux-3.10.git] / net / decnet / dn_table.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 Routing Forwarding Information Base (Routing Tables)
7  *
8  * Author:      Steve Whitehouse <SteveW@ACM.org>
9  *              Mostly copied from the IPv4 routing code
10  *
11  *
12  * Changes:
13  *
14  */
15 #include <linux/string.h>
16 #include <linux/net.h>
17 #include <linux/socket.h>
18 #include <linux/sockios.h>
19 #include <linux/init.h>
20 #include <linux/skbuff.h>
21 #include <linux/netlink.h>
22 #include <linux/rtnetlink.h>
23 #include <linux/proc_fs.h>
24 #include <linux/netdevice.h>
25 #include <linux/timer.h>
26 #include <linux/spinlock.h>
27 #include <asm/atomic.h>
28 #include <asm/uaccess.h>
29 #include <linux/route.h> /* RTF_xxx */
30 #include <net/neighbour.h>
31 #include <net/dst.h>
32 #include <net/flow.h>
33 #include <net/dn.h>
34 #include <net/dn_route.h>
35 #include <net/dn_fib.h>
36 #include <net/dn_neigh.h>
37 #include <net/dn_dev.h>
38
39 struct dn_zone
40 {
41         struct dn_zone          *dz_next;
42         struct dn_fib_node      **dz_hash;
43         int                     dz_nent;
44         int                     dz_divisor;
45         u32                     dz_hashmask;
46 #define DZ_HASHMASK(dz) ((dz)->dz_hashmask)
47         int                     dz_order;
48         __le16                  dz_mask;
49 #define DZ_MASK(dz)     ((dz)->dz_mask)
50 };
51
52 struct dn_hash
53 {
54         struct dn_zone  *dh_zones[17];
55         struct dn_zone  *dh_zone_list;
56 };
57
58 #define dz_key_0(key)           ((key).datum = 0)
59 #define dz_prefix(key,dz)       ((key).datum)
60
61 #define for_nexthops(fi) { int nhsel; const struct dn_fib_nh *nh;\
62         for(nhsel = 0, nh = (fi)->fib_nh; nhsel < (fi)->fib_nhs; nh++, nhsel++)
63
64 #define endfor_nexthops(fi) }
65
66 #define DN_MAX_DIVISOR 1024
67 #define DN_S_ZOMBIE 1
68 #define DN_S_ACCESSED 2
69
70 #define DN_FIB_SCAN(f, fp) \
71 for( ; ((f) = *(fp)) != NULL; (fp) = &(f)->fn_next)
72
73 #define DN_FIB_SCAN_KEY(f, fp, key) \
74 for( ; ((f) = *(fp)) != NULL && dn_key_eq((f)->fn_key, (key)); (fp) = &(f)->fn_next)
75
76 #define RT_TABLE_MIN 1
77
78 static DEFINE_RWLOCK(dn_fib_tables_lock);
79 struct dn_fib_table *dn_fib_tables[RT_TABLE_MAX + 1];
80
81 static kmem_cache_t *dn_hash_kmem __read_mostly;
82 static int dn_fib_hash_zombies;
83
84 static inline dn_fib_idx_t dn_hash(dn_fib_key_t key, struct dn_zone *dz)
85 {
86         u16 h = dn_ntohs(key.datum)>>(16 - dz->dz_order);
87         h ^= (h >> 10);
88         h ^= (h >> 6);
89         h &= DZ_HASHMASK(dz);
90         return *(dn_fib_idx_t *)&h;
91 }
92
93 static inline dn_fib_key_t dz_key(__le16 dst, struct dn_zone *dz)
94 {
95         dn_fib_key_t k;
96         k.datum = dst & DZ_MASK(dz);
97         return k;
98 }
99
100 static inline struct dn_fib_node **dn_chain_p(dn_fib_key_t key, struct dn_zone *dz)
101 {
102         return &dz->dz_hash[dn_hash(key, dz).datum];
103 }
104
105 static inline struct dn_fib_node *dz_chain(dn_fib_key_t key, struct dn_zone *dz)
106 {
107         return dz->dz_hash[dn_hash(key, dz).datum];
108 }
109
110 static inline int dn_key_eq(dn_fib_key_t a, dn_fib_key_t b)
111 {
112         return a.datum == b.datum;
113 }
114
115 static inline int dn_key_leq(dn_fib_key_t a, dn_fib_key_t b)
116 {
117         return a.datum <= b.datum;
118 }
119
120 static inline void dn_rebuild_zone(struct dn_zone *dz,
121                                    struct dn_fib_node **old_ht,
122                                    int old_divisor)
123 {
124         int i;
125         struct dn_fib_node *f, **fp, *next;
126
127         for(i = 0; i < old_divisor; i++) {
128                 for(f = old_ht[i]; f; f = f->fn_next) {
129                         next = f->fn_next;
130                         for(fp = dn_chain_p(f->fn_key, dz);
131                                 *fp && dn_key_leq((*fp)->fn_key, f->fn_key);
132                                 fp = &(*fp)->fn_next)
133                                 /* NOTHING */;
134                         f->fn_next = *fp;
135                         *fp = f;
136                 }
137         }
138 }
139
140 static void dn_rehash_zone(struct dn_zone *dz)
141 {
142         struct dn_fib_node **ht, **old_ht;
143         int old_divisor, new_divisor;
144         u32 new_hashmask;
145
146         old_divisor = dz->dz_divisor;
147
148         switch(old_divisor) {
149                 case 16:
150                         new_divisor = 256;
151                         new_hashmask = 0xFF;
152                         break;
153                 default:
154                         printk(KERN_DEBUG "DECnet: dn_rehash_zone: BUG! %d\n", old_divisor);
155                 case 256:
156                         new_divisor = 1024;
157                         new_hashmask = 0x3FF;
158                         break;
159         }
160
161         ht = kcalloc(new_divisor, sizeof(struct dn_fib_node*), GFP_KERNEL);
162         if (ht == NULL)
163                 return;
164
165         write_lock_bh(&dn_fib_tables_lock);
166         old_ht = dz->dz_hash;
167         dz->dz_hash = ht;
168         dz->dz_hashmask = new_hashmask;
169         dz->dz_divisor = new_divisor;
170         dn_rebuild_zone(dz, old_ht, old_divisor);
171         write_unlock_bh(&dn_fib_tables_lock);
172         kfree(old_ht);
173 }
174
175 static void dn_free_node(struct dn_fib_node *f)
176 {
177         dn_fib_release_info(DN_FIB_INFO(f));
178         kmem_cache_free(dn_hash_kmem, f);
179 }
180
181
182 static struct dn_zone *dn_new_zone(struct dn_hash *table, int z)
183 {
184         int i;
185         struct dn_zone *dz = kzalloc(sizeof(struct dn_zone), GFP_KERNEL);
186         if (!dz)
187                 return NULL;
188
189         if (z) {
190                 dz->dz_divisor = 16;
191                 dz->dz_hashmask = 0x0F;
192         } else {
193                 dz->dz_divisor = 1;
194                 dz->dz_hashmask = 0;
195         }
196
197         dz->dz_hash = kcalloc(dz->dz_divisor, sizeof(struct dn_fib_node *), GFP_KERNEL);
198         if (!dz->dz_hash) {
199                 kfree(dz);
200                 return NULL;
201         }
202
203         dz->dz_order = z;
204         dz->dz_mask = dnet_make_mask(z);
205
206         for(i = z + 1; i <= 16; i++)
207                 if (table->dh_zones[i])
208                         break;
209
210         write_lock_bh(&dn_fib_tables_lock);
211         if (i>16) {
212                 dz->dz_next = table->dh_zone_list;
213                 table->dh_zone_list = dz;
214         } else {
215                 dz->dz_next = table->dh_zones[i]->dz_next;
216                 table->dh_zones[i]->dz_next = dz;
217         }
218         table->dh_zones[z] = dz;
219         write_unlock_bh(&dn_fib_tables_lock);
220         return dz;
221 }
222
223
224 static int dn_fib_nh_match(struct rtmsg *r, struct nlmsghdr *nlh, struct dn_kern_rta *rta, struct dn_fib_info *fi)
225 {
226         struct rtnexthop *nhp;
227         int nhlen;
228
229         if (rta->rta_priority && *rta->rta_priority != fi->fib_priority)
230                 return 1;
231
232         if (rta->rta_oif || rta->rta_gw) {
233                 if ((!rta->rta_oif || *rta->rta_oif == fi->fib_nh->nh_oif) &&
234                     (!rta->rta_gw  || memcmp(rta->rta_gw, &fi->fib_nh->nh_gw, 2) == 0))
235                         return 0;
236                 return 1;
237         }
238
239         if (rta->rta_mp == NULL)
240                 return 0;
241
242         nhp = RTA_DATA(rta->rta_mp);
243         nhlen = RTA_PAYLOAD(rta->rta_mp);
244
245         for_nexthops(fi) {
246                 int attrlen = nhlen - sizeof(struct rtnexthop);
247                 __le16 gw;
248
249                 if (attrlen < 0 || (nhlen -= nhp->rtnh_len) < 0)
250                         return -EINVAL;
251                 if (nhp->rtnh_ifindex && nhp->rtnh_ifindex != nh->nh_oif)
252                         return 1;
253                 if (attrlen) {
254                         gw = dn_fib_get_attr16(RTNH_DATA(nhp), attrlen, RTA_GATEWAY);
255
256                         if (gw && gw != nh->nh_gw)
257                                 return 1;
258                 }
259                 nhp = RTNH_NEXT(nhp);
260         } endfor_nexthops(fi);
261
262         return 0;
263 }
264
265 static int dn_fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
266                         u8 tb_id, u8 type, u8 scope, void *dst, int dst_len,
267                         struct dn_fib_info *fi, unsigned int flags)
268 {
269         struct rtmsg *rtm;
270         struct nlmsghdr *nlh;
271         unsigned char *b = skb->tail;
272
273         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*rtm), flags);
274         rtm = NLMSG_DATA(nlh);
275         rtm->rtm_family = AF_DECnet;
276         rtm->rtm_dst_len = dst_len;
277         rtm->rtm_src_len = 0;
278         rtm->rtm_tos = 0;
279         rtm->rtm_table = tb_id;
280         rtm->rtm_flags = fi->fib_flags;
281         rtm->rtm_scope = scope;
282         rtm->rtm_type  = type;
283         if (rtm->rtm_dst_len)
284                 RTA_PUT(skb, RTA_DST, 2, dst);
285         rtm->rtm_protocol = fi->fib_protocol;
286         if (fi->fib_priority)
287                 RTA_PUT(skb, RTA_PRIORITY, 4, &fi->fib_priority);
288         if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0)
289                 goto rtattr_failure;
290         if (fi->fib_nhs == 1) {
291                 if (fi->fib_nh->nh_gw)
292                         RTA_PUT(skb, RTA_GATEWAY, 2, &fi->fib_nh->nh_gw);
293                 if (fi->fib_nh->nh_oif)
294                         RTA_PUT(skb, RTA_OIF, sizeof(int), &fi->fib_nh->nh_oif);
295         }
296         if (fi->fib_nhs > 1) {
297                 struct rtnexthop *nhp;
298                 struct rtattr *mp_head;
299                 if (skb_tailroom(skb) <= RTA_SPACE(0))
300                         goto rtattr_failure;
301                 mp_head = (struct rtattr *)skb_put(skb, RTA_SPACE(0));
302
303                 for_nexthops(fi) {
304                         if (skb_tailroom(skb) < RTA_ALIGN(RTA_ALIGN(sizeof(*nhp)) + 4))
305                                 goto rtattr_failure;
306                         nhp = (struct rtnexthop *)skb_put(skb, RTA_ALIGN(sizeof(*nhp)));
307                         nhp->rtnh_flags = nh->nh_flags & 0xFF;
308                         nhp->rtnh_hops = nh->nh_weight - 1;
309                         nhp->rtnh_ifindex = nh->nh_oif;
310                         if (nh->nh_gw)
311                                 RTA_PUT(skb, RTA_GATEWAY, 2, &nh->nh_gw);
312                         nhp->rtnh_len = skb->tail - (unsigned char *)nhp;
313                 } endfor_nexthops(fi);
314                 mp_head->rta_type = RTA_MULTIPATH;
315                 mp_head->rta_len = skb->tail - (u8*)mp_head;
316         }
317
318         nlh->nlmsg_len = skb->tail - b;
319         return skb->len;
320
321
322 nlmsg_failure:
323 rtattr_failure:
324         skb_trim(skb, b - skb->data);
325         return -1;
326 }
327
328
329 static void dn_rtmsg_fib(int event, struct dn_fib_node *f, int z, int tb_id,
330                         struct nlmsghdr *nlh, struct netlink_skb_parms *req)
331 {
332         struct sk_buff *skb;
333         u32 pid = req ? req->pid : 0;
334         int size = NLMSG_SPACE(sizeof(struct rtmsg) + 256);
335
336         skb = alloc_skb(size, GFP_KERNEL);
337         if (!skb)
338                 return;
339
340         if (dn_fib_dump_info(skb, pid, nlh->nlmsg_seq, event, tb_id, 
341                                 f->fn_type, f->fn_scope, &f->fn_key, z, 
342                                 DN_FIB_INFO(f), 0) < 0) {
343                 kfree_skb(skb);
344                 return;
345         }
346         NETLINK_CB(skb).dst_group = RTNLGRP_DECnet_ROUTE;
347         if (nlh->nlmsg_flags & NLM_F_ECHO)
348                 atomic_inc(&skb->users);
349         netlink_broadcast(rtnl, skb, pid, RTNLGRP_DECnet_ROUTE, GFP_KERNEL);
350         if (nlh->nlmsg_flags & NLM_F_ECHO)
351                 netlink_unicast(rtnl, skb, pid, MSG_DONTWAIT);
352 }
353
354 static __inline__ int dn_hash_dump_bucket(struct sk_buff *skb, 
355                                 struct netlink_callback *cb,
356                                 struct dn_fib_table *tb,
357                                 struct dn_zone *dz,
358                                 struct dn_fib_node *f)
359 {
360         int i, s_i;
361
362         s_i = cb->args[3];
363         for(i = 0; f; i++, f = f->fn_next) {
364                 if (i < s_i)
365                         continue;
366                 if (f->fn_state & DN_S_ZOMBIE)
367                         continue;
368                 if (dn_fib_dump_info(skb, NETLINK_CB(cb->skb).pid, 
369                                 cb->nlh->nlmsg_seq,
370                                 RTM_NEWROUTE,
371                                 tb->n, 
372                                 (f->fn_state & DN_S_ZOMBIE) ? 0 : f->fn_type,
373                                 f->fn_scope, &f->fn_key, dz->dz_order, 
374                                 f->fn_info, NLM_F_MULTI) < 0) {
375                         cb->args[3] = i;
376                         return -1;
377                 }
378         }
379         cb->args[3] = i;
380         return skb->len;
381 }
382
383 static __inline__ int dn_hash_dump_zone(struct sk_buff *skb, 
384                                 struct netlink_callback *cb,
385                                 struct dn_fib_table *tb,
386                                 struct dn_zone *dz)
387 {
388         int h, s_h;
389
390         s_h = cb->args[2];
391         for(h = 0; h < dz->dz_divisor; h++) {
392                 if (h < s_h)
393                         continue;
394                 if (h > s_h)
395                         memset(&cb->args[3], 0, sizeof(cb->args) - 3*sizeof(cb->args[0]));
396                 if (dz->dz_hash == NULL || dz->dz_hash[h] == NULL)
397                         continue;
398                 if (dn_hash_dump_bucket(skb, cb, tb, dz, dz->dz_hash[h]) < 0) {
399                         cb->args[2] = h;
400                         return -1;
401                 }
402         }
403         cb->args[2] = h;
404         return skb->len;
405 }
406
407 static int dn_fib_table_dump(struct dn_fib_table *tb, struct sk_buff *skb, 
408                                 struct netlink_callback *cb)
409 {
410         int m, s_m;
411         struct dn_zone *dz;
412         struct dn_hash *table = (struct dn_hash *)tb->data;
413
414         s_m = cb->args[1];
415         read_lock(&dn_fib_tables_lock);
416         for(dz = table->dh_zone_list, m = 0; dz; dz = dz->dz_next, m++) {
417                 if (m < s_m)
418                         continue;
419                 if (m > s_m)
420                         memset(&cb->args[2], 0, sizeof(cb->args) - 2*sizeof(cb->args[0]));
421
422                 if (dn_hash_dump_zone(skb, cb, tb, dz) < 0) {
423                         cb->args[1] = m;
424                         read_unlock(&dn_fib_tables_lock);
425                         return -1;
426                 }
427         }
428         read_unlock(&dn_fib_tables_lock);
429         cb->args[1] = m;
430
431         return skb->len;
432 }
433
434 static int dn_fib_table_insert(struct dn_fib_table *tb, struct rtmsg *r, struct dn_kern_rta *rta, struct nlmsghdr *n, struct netlink_skb_parms *req)
435 {
436         struct dn_hash *table = (struct dn_hash *)tb->data;
437         struct dn_fib_node *new_f, *f, **fp, **del_fp;
438         struct dn_zone *dz;
439         struct dn_fib_info *fi;
440         int z = r->rtm_dst_len;
441         int type = r->rtm_type;
442         dn_fib_key_t key;
443         int err;
444
445         if (z > 16)
446                 return -EINVAL;
447
448         dz = table->dh_zones[z];
449         if (!dz && !(dz = dn_new_zone(table, z)))
450                 return -ENOBUFS;
451
452         dz_key_0(key);
453         if (rta->rta_dst) {
454                 __le16 dst;
455                 memcpy(&dst, rta->rta_dst, 2);
456                 if (dst & ~DZ_MASK(dz))
457                         return -EINVAL;
458                 key = dz_key(dst, dz);
459         }
460
461         if ((fi = dn_fib_create_info(r, rta, n, &err)) == NULL)
462                 return err;
463
464         if (dz->dz_nent > (dz->dz_divisor << 2) &&
465                         dz->dz_divisor > DN_MAX_DIVISOR &&
466                         (z==16 || (1<<z) > dz->dz_divisor))
467                 dn_rehash_zone(dz);
468
469         fp = dn_chain_p(key, dz);
470
471         DN_FIB_SCAN(f, fp) {
472                 if (dn_key_leq(key, f->fn_key))
473                         break;
474         }
475
476         del_fp = NULL;
477
478         if (f && (f->fn_state & DN_S_ZOMBIE) &&
479                         dn_key_eq(f->fn_key, key)) {
480                 del_fp = fp;
481                 fp = &f->fn_next;
482                 f = *fp;
483                 goto create;
484         }
485
486         DN_FIB_SCAN_KEY(f, fp, key) {
487                 if (fi->fib_priority <= DN_FIB_INFO(f)->fib_priority)
488                         break;
489         }
490
491         if (f && dn_key_eq(f->fn_key, key) &&
492                         fi->fib_priority == DN_FIB_INFO(f)->fib_priority) {
493                 struct dn_fib_node **ins_fp;
494
495                 err = -EEXIST;
496                 if (n->nlmsg_flags & NLM_F_EXCL)
497                         goto out;
498
499                 if (n->nlmsg_flags & NLM_F_REPLACE) {
500                         del_fp = fp;
501                         fp = &f->fn_next;
502                         f = *fp;
503                         goto replace;
504                 }
505
506                 ins_fp = fp;
507                 err = -EEXIST;
508
509                 DN_FIB_SCAN_KEY(f, fp, key) {
510                         if (fi->fib_priority != DN_FIB_INFO(f)->fib_priority)
511                                 break;
512                         if (f->fn_type == type && f->fn_scope == r->rtm_scope
513                                         && DN_FIB_INFO(f) == fi)
514                                 goto out;
515                 }
516
517                 if (!(n->nlmsg_flags & NLM_F_APPEND)) {
518                         fp = ins_fp;
519                         f = *fp;
520                 }
521         }
522
523 create:
524         err = -ENOENT;
525         if (!(n->nlmsg_flags & NLM_F_CREATE))
526                 goto out;
527
528 replace:
529         err = -ENOBUFS;
530         new_f = kmem_cache_alloc(dn_hash_kmem, SLAB_KERNEL);
531         if (new_f == NULL)
532                 goto out;
533
534         memset(new_f, 0, sizeof(struct dn_fib_node));
535
536         new_f->fn_key = key;
537         new_f->fn_type = type;
538         new_f->fn_scope = r->rtm_scope;
539         DN_FIB_INFO(new_f) = fi;
540
541         new_f->fn_next = f;
542         write_lock_bh(&dn_fib_tables_lock);
543         *fp = new_f;
544         write_unlock_bh(&dn_fib_tables_lock);
545         dz->dz_nent++;
546
547         if (del_fp) {
548                 f = *del_fp;
549                 write_lock_bh(&dn_fib_tables_lock);
550                 *del_fp = f->fn_next;
551                 write_unlock_bh(&dn_fib_tables_lock);
552
553                 if (!(f->fn_state & DN_S_ZOMBIE))
554                         dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
555                 if (f->fn_state & DN_S_ACCESSED)
556                         dn_rt_cache_flush(-1);
557                 dn_free_node(f);
558                 dz->dz_nent--;
559         } else {
560                 dn_rt_cache_flush(-1);
561         }
562
563         dn_rtmsg_fib(RTM_NEWROUTE, new_f, z, tb->n, n, req);
564
565         return 0;
566 out:
567         dn_fib_release_info(fi);
568         return err;
569 }
570
571
572 static int dn_fib_table_delete(struct dn_fib_table *tb, struct rtmsg *r, struct dn_kern_rta *rta, struct nlmsghdr *n, struct netlink_skb_parms *req)
573 {
574         struct dn_hash *table = (struct dn_hash*)tb->data;
575         struct dn_fib_node **fp, **del_fp, *f;
576         int z = r->rtm_dst_len;
577         struct dn_zone *dz;
578         dn_fib_key_t key;
579         int matched;
580
581
582         if (z > 16)
583                 return -EINVAL;
584
585         if ((dz = table->dh_zones[z]) == NULL)
586                 return -ESRCH;
587
588         dz_key_0(key);
589         if (rta->rta_dst) {
590                 __le16 dst;
591                 memcpy(&dst, rta->rta_dst, 2);
592                 if (dst & ~DZ_MASK(dz))
593                         return -EINVAL;
594                 key = dz_key(dst, dz);
595         }
596
597         fp = dn_chain_p(key, dz);
598
599         DN_FIB_SCAN(f, fp) {
600                 if (dn_key_eq(f->fn_key, key))
601                         break;
602                 if (dn_key_leq(key, f->fn_key))
603                         return -ESRCH;
604         }
605
606         matched = 0;
607         del_fp = NULL;
608         DN_FIB_SCAN_KEY(f, fp, key) {
609                 struct dn_fib_info *fi = DN_FIB_INFO(f);
610
611                 if (f->fn_state & DN_S_ZOMBIE)
612                         return -ESRCH;
613
614                 matched++;
615
616                 if (del_fp == NULL &&
617                                 (!r->rtm_type || f->fn_type == r->rtm_type) &&
618                                 (r->rtm_scope == RT_SCOPE_NOWHERE || f->fn_scope == r->rtm_scope) &&
619                                 (!r->rtm_protocol || 
620                                         fi->fib_protocol == r->rtm_protocol) &&
621                                 dn_fib_nh_match(r, n, rta, fi) == 0)
622                         del_fp = fp;
623         }
624
625         if (del_fp) {
626                 f = *del_fp;
627                 dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
628
629                 if (matched != 1) {
630                         write_lock_bh(&dn_fib_tables_lock);
631                         *del_fp = f->fn_next;
632                         write_unlock_bh(&dn_fib_tables_lock);
633
634                         if (f->fn_state & DN_S_ACCESSED)
635                                 dn_rt_cache_flush(-1);
636                         dn_free_node(f);
637                         dz->dz_nent--;
638                 } else {
639                         f->fn_state |= DN_S_ZOMBIE;
640                         if (f->fn_state & DN_S_ACCESSED) {
641                                 f->fn_state &= ~DN_S_ACCESSED;
642                                 dn_rt_cache_flush(-1);
643                         }
644                         if (++dn_fib_hash_zombies > 128)
645                                 dn_fib_flush();
646                 }
647
648                 return 0;
649         }
650
651         return -ESRCH;
652 }
653
654 static inline int dn_flush_list(struct dn_fib_node **fp, int z, struct dn_hash *table)
655 {
656         int found = 0;
657         struct dn_fib_node *f;
658
659         while((f = *fp) != NULL) {
660                 struct dn_fib_info *fi = DN_FIB_INFO(f);
661
662                 if (fi && ((f->fn_state & DN_S_ZOMBIE) || (fi->fib_flags & RTNH_F_DEAD))) {
663                         write_lock_bh(&dn_fib_tables_lock);
664                         *fp = f->fn_next;
665                         write_unlock_bh(&dn_fib_tables_lock);
666
667                         dn_free_node(f);
668                         found++;
669                         continue;
670                 }
671                 fp = &f->fn_next;
672         }
673
674         return found;
675 }
676
677 static int dn_fib_table_flush(struct dn_fib_table *tb)
678 {
679         struct dn_hash *table = (struct dn_hash *)tb->data;
680         struct dn_zone *dz;
681         int found = 0;
682
683         dn_fib_hash_zombies = 0;
684         for(dz = table->dh_zone_list; dz; dz = dz->dz_next) {
685                 int i;
686                 int tmp = 0;
687                 for(i = dz->dz_divisor-1; i >= 0; i--)
688                         tmp += dn_flush_list(&dz->dz_hash[i], dz->dz_order, table);
689                 dz->dz_nent -= tmp;
690                 found += tmp;
691         }
692
693         return found;
694 }
695
696 static int dn_fib_table_lookup(struct dn_fib_table *tb, const struct flowi *flp, struct dn_fib_res *res)
697 {
698         int err;
699         struct dn_zone *dz;
700         struct dn_hash *t = (struct dn_hash *)tb->data;
701
702         read_lock(&dn_fib_tables_lock);
703         for(dz = t->dh_zone_list; dz; dz = dz->dz_next) {
704                 struct dn_fib_node *f;
705                 dn_fib_key_t k = dz_key(flp->fld_dst, dz);
706
707                 for(f = dz_chain(k, dz); f; f = f->fn_next) {
708                         if (!dn_key_eq(k, f->fn_key)) {
709                                 if (dn_key_leq(k, f->fn_key))
710                                         break;
711                                 else
712                                         continue;
713                         }
714
715                         f->fn_state |= DN_S_ACCESSED;
716
717                         if (f->fn_state&DN_S_ZOMBIE)
718                                 continue;
719
720                         if (f->fn_scope < flp->fld_scope)
721                                 continue;
722
723                         err = dn_fib_semantic_match(f->fn_type, DN_FIB_INFO(f), flp, res);
724
725                         if (err == 0) {
726                                 res->type = f->fn_type;
727                                 res->scope = f->fn_scope; 
728                                 res->prefixlen = dz->dz_order;
729                                 goto out;
730                         }
731                         if (err < 0)
732                                 goto out;
733                 }
734         }
735         err = 1;
736 out:
737         read_unlock(&dn_fib_tables_lock);
738         return err;
739 }
740
741
742 struct dn_fib_table *dn_fib_get_table(int n, int create)
743 {
744         struct dn_fib_table *t;
745
746         if (n < RT_TABLE_MIN)
747                 return NULL;
748
749         if (n > RT_TABLE_MAX)
750                 return NULL;
751
752         if (dn_fib_tables[n]) 
753                 return dn_fib_tables[n];
754
755         if (!create)
756                 return NULL;
757
758         if (in_interrupt() && net_ratelimit()) {
759                 printk(KERN_DEBUG "DECnet: BUG! Attempt to create routing table from interrupt\n"); 
760                 return NULL;
761         }
762         if ((t = kmalloc(sizeof(struct dn_fib_table) + sizeof(struct dn_hash), GFP_KERNEL)) == NULL)
763                 return NULL;
764
765         memset(t, 0, sizeof(struct dn_fib_table));
766
767         t->n = n;
768         t->insert = dn_fib_table_insert;
769         t->delete = dn_fib_table_delete;
770         t->lookup = dn_fib_table_lookup;
771         t->flush  = dn_fib_table_flush;
772         t->dump = dn_fib_table_dump;
773         memset(t->data, 0, sizeof(struct dn_hash));
774         dn_fib_tables[n] = t;
775
776         return t;
777 }
778
779 static void dn_fib_del_tree(int n)
780 {
781         struct dn_fib_table *t;
782
783         write_lock(&dn_fib_tables_lock);
784         t = dn_fib_tables[n];
785         dn_fib_tables[n] = NULL;
786         write_unlock(&dn_fib_tables_lock);
787
788         kfree(t);
789 }
790
791 struct dn_fib_table *dn_fib_empty_table(void)
792 {
793         int id;
794
795         for(id = RT_TABLE_MIN; id <= RT_TABLE_MAX; id++)
796                 if (dn_fib_tables[id] == NULL)
797                         return dn_fib_get_table(id, 1);
798         return NULL;
799 }
800
801 void __init dn_fib_table_init(void)
802 {
803         dn_hash_kmem = kmem_cache_create("dn_fib_info_cache",
804                                         sizeof(struct dn_fib_info),
805                                         0, SLAB_HWCACHE_ALIGN,
806                                         NULL, NULL);
807 }
808
809 void __exit dn_fib_table_cleanup(void)
810 {
811         int i;
812
813         for (i = RT_TABLE_MIN; i <= RT_TABLE_MAX; ++i)
814                 dn_fib_del_tree(i);
815
816         return;
817 }