[NETLINK]: Convert netlink users to use group numbers instead of bitmasks
[linux-2.6.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/config.h>
16 #include <linux/string.h>
17 #include <linux/net.h>
18 #include <linux/socket.h>
19 #include <linux/sockios.h>
20 #include <linux/init.h>
21 #include <linux/skbuff.h>
22 #include <linux/netlink.h>
23 #include <linux/rtnetlink.h>
24 #include <linux/proc_fs.h>
25 #include <linux/netdevice.h>
26 #include <linux/timer.h>
27 #include <linux/spinlock.h>
28 #include <asm/atomic.h>
29 #include <asm/uaccess.h>
30 #include <linux/route.h> /* RTF_xxx */
31 #include <net/neighbour.h>
32 #include <net/dst.h>
33 #include <net/flow.h>
34 #include <net/dn.h>
35 #include <net/dn_route.h>
36 #include <net/dn_fib.h>
37 #include <net/dn_neigh.h>
38 #include <net/dn_dev.h>
39
40 struct dn_zone
41 {
42         struct dn_zone          *dz_next;
43         struct dn_fib_node      **dz_hash;
44         int                     dz_nent;
45         int                     dz_divisor;
46         u32                     dz_hashmask;
47 #define DZ_HASHMASK(dz) ((dz)->dz_hashmask)
48         int                     dz_order;
49         u16                     dz_mask;
50 #define DZ_MASK(dz)     ((dz)->dz_mask)
51 };
52
53 struct dn_hash
54 {
55         struct dn_zone  *dh_zones[17];
56         struct dn_zone  *dh_zone_list;
57 };
58
59 #define dz_key_0(key)           ((key).datum = 0)
60 #define dz_prefix(key,dz)       ((key).datum)
61
62 #define for_nexthops(fi) { int nhsel; const struct dn_fib_nh *nh;\
63         for(nhsel = 0, nh = (fi)->fib_nh; nhsel < (fi)->fib_nhs; nh++, nhsel++)
64
65 #define endfor_nexthops(fi) }
66
67 #define DN_MAX_DIVISOR 1024
68 #define DN_S_ZOMBIE 1
69 #define DN_S_ACCESSED 2
70
71 #define DN_FIB_SCAN(f, fp) \
72 for( ; ((f) = *(fp)) != NULL; (fp) = &(f)->fn_next)
73
74 #define DN_FIB_SCAN_KEY(f, fp, key) \
75 for( ; ((f) = *(fp)) != NULL && dn_key_eq((f)->fn_key, (key)); (fp) = &(f)->fn_next)
76
77 #define RT_TABLE_MIN 1
78
79 static DEFINE_RWLOCK(dn_fib_tables_lock);
80 struct dn_fib_table *dn_fib_tables[RT_TABLE_MAX + 1];
81
82 static kmem_cache_t *dn_hash_kmem;
83 static int dn_fib_hash_zombies;
84
85 static inline dn_fib_idx_t dn_hash(dn_fib_key_t key, struct dn_zone *dz)
86 {
87         u16 h = ntohs(key.datum)>>(16 - dz->dz_order);
88         h ^= (h >> 10);
89         h ^= (h >> 6);
90         h &= DZ_HASHMASK(dz);
91         return *(dn_fib_idx_t *)&h;
92 }
93
94 static inline dn_fib_key_t dz_key(u16 dst, struct dn_zone *dz)
95 {
96         dn_fib_key_t k;
97         k.datum = dst & DZ_MASK(dz);
98         return k;
99 }
100
101 static inline struct dn_fib_node **dn_chain_p(dn_fib_key_t key, struct dn_zone *dz)
102 {
103         return &dz->dz_hash[dn_hash(key, dz).datum];
104 }
105
106 static inline struct dn_fib_node *dz_chain(dn_fib_key_t key, struct dn_zone *dz)
107 {
108         return dz->dz_hash[dn_hash(key, dz).datum];
109 }
110
111 static inline int dn_key_eq(dn_fib_key_t a, dn_fib_key_t b)
112 {
113         return a.datum == b.datum;
114 }
115
116 static inline int dn_key_leq(dn_fib_key_t a, dn_fib_key_t b)
117 {
118         return a.datum <= b.datum;
119 }
120
121 static inline void dn_rebuild_zone(struct dn_zone *dz,
122                                    struct dn_fib_node **old_ht,
123                                    int old_divisor)
124 {
125         int i;
126         struct dn_fib_node *f, **fp, *next;
127
128         for(i = 0; i < old_divisor; i++) {
129                 for(f = old_ht[i]; f; f = f->fn_next) {
130                         next = f->fn_next;
131                         for(fp = dn_chain_p(f->fn_key, dz);
132                                 *fp && dn_key_leq((*fp)->fn_key, f->fn_key);
133                                 fp = &(*fp)->fn_next)
134                                 /* NOTHING */;
135                         f->fn_next = *fp;
136                         *fp = f;
137                 }
138         }
139 }
140
141 static void dn_rehash_zone(struct dn_zone *dz)
142 {
143         struct dn_fib_node **ht, **old_ht;
144         int old_divisor, new_divisor;
145         u32 new_hashmask;
146
147         old_divisor = dz->dz_divisor;
148
149         switch(old_divisor) {
150                 case 16:
151                         new_divisor = 256;
152                         new_hashmask = 0xFF;
153                         break;
154                 default:
155                         printk(KERN_DEBUG "DECnet: dn_rehash_zone: BUG! %d\n", old_divisor);
156                 case 256:
157                         new_divisor = 1024;
158                         new_hashmask = 0x3FF;
159                         break;
160         }
161
162         ht = kmalloc(new_divisor*sizeof(struct dn_fib_node*), GFP_KERNEL);
163
164         if (ht == NULL)
165                 return;
166
167         memset(ht, 0, new_divisor*sizeof(struct dn_fib_node *));
168         write_lock_bh(&dn_fib_tables_lock);
169         old_ht = dz->dz_hash;
170         dz->dz_hash = ht;
171         dz->dz_hashmask = new_hashmask;
172         dz->dz_divisor = new_divisor;
173         dn_rebuild_zone(dz, old_ht, old_divisor);
174         write_unlock_bh(&dn_fib_tables_lock);
175         kfree(old_ht);
176 }
177
178 static void dn_free_node(struct dn_fib_node *f)
179 {
180         dn_fib_release_info(DN_FIB_INFO(f));
181         kmem_cache_free(dn_hash_kmem, f);
182 }
183
184
185 static struct dn_zone *dn_new_zone(struct dn_hash *table, int z)
186 {
187         int i;
188         struct dn_zone *dz = kmalloc(sizeof(struct dn_zone), GFP_KERNEL);
189         if (!dz)
190                 return NULL;
191
192         memset(dz, 0, sizeof(struct dn_zone));
193         if (z) {
194                 dz->dz_divisor = 16;
195                 dz->dz_hashmask = 0x0F;
196         } else {
197                 dz->dz_divisor = 1;
198                 dz->dz_hashmask = 0;
199         }
200
201         dz->dz_hash = kmalloc(dz->dz_divisor*sizeof(struct dn_fib_node *), GFP_KERNEL);
202
203         if (!dz->dz_hash) {
204                 kfree(dz);
205                 return NULL;
206         }
207
208         memset(dz->dz_hash, 0, dz->dz_divisor*sizeof(struct dn_fib_node*));
209         dz->dz_order = z;
210         dz->dz_mask = dnet_make_mask(z);
211
212         for(i = z + 1; i <= 16; i++)
213                 if (table->dh_zones[i])
214                         break;
215
216         write_lock_bh(&dn_fib_tables_lock);
217         if (i>16) {
218                 dz->dz_next = table->dh_zone_list;
219                 table->dh_zone_list = dz;
220         } else {
221                 dz->dz_next = table->dh_zones[i]->dz_next;
222                 table->dh_zones[i]->dz_next = dz;
223         }
224         table->dh_zones[z] = dz;
225         write_unlock_bh(&dn_fib_tables_lock);
226         return dz;
227 }
228
229
230 static int dn_fib_nh_match(struct rtmsg *r, struct nlmsghdr *nlh, struct dn_kern_rta *rta, struct dn_fib_info *fi)
231 {
232         struct rtnexthop *nhp;
233         int nhlen;
234
235         if (rta->rta_priority && *rta->rta_priority != fi->fib_priority)
236                 return 1;
237
238         if (rta->rta_oif || rta->rta_gw) {
239                 if ((!rta->rta_oif || *rta->rta_oif == fi->fib_nh->nh_oif) &&
240                     (!rta->rta_gw  || memcmp(rta->rta_gw, &fi->fib_nh->nh_gw, 2) == 0))
241                         return 0;
242                 return 1;
243         }
244
245         if (rta->rta_mp == NULL)
246                 return 0;
247
248         nhp = RTA_DATA(rta->rta_mp);
249         nhlen = RTA_PAYLOAD(rta->rta_mp);
250
251         for_nexthops(fi) {
252                 int attrlen = nhlen - sizeof(struct rtnexthop);
253                 dn_address gw;
254
255                 if (attrlen < 0 || (nhlen -= nhp->rtnh_len) < 0)
256                         return -EINVAL;
257                 if (nhp->rtnh_ifindex && nhp->rtnh_ifindex != nh->nh_oif)
258                         return 1;
259                 if (attrlen) {
260                         gw = dn_fib_get_attr16(RTNH_DATA(nhp), attrlen, RTA_GATEWAY);
261
262                         if (gw && gw != nh->nh_gw)
263                                 return 1;
264                 }
265                 nhp = RTNH_NEXT(nhp);
266         } endfor_nexthops(fi);
267
268         return 0;
269 }
270
271 static int dn_fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
272                         u8 tb_id, u8 type, u8 scope, void *dst, int dst_len,
273                         struct dn_fib_info *fi, unsigned int flags)
274 {
275         struct rtmsg *rtm;
276         struct nlmsghdr *nlh;
277         unsigned char *b = skb->tail;
278
279         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*rtm), flags);
280         rtm = NLMSG_DATA(nlh);
281         rtm->rtm_family = AF_DECnet;
282         rtm->rtm_dst_len = dst_len;
283         rtm->rtm_src_len = 0;
284         rtm->rtm_tos = 0;
285         rtm->rtm_table = tb_id;
286         rtm->rtm_flags = fi->fib_flags;
287         rtm->rtm_scope = scope;
288         rtm->rtm_type  = type;
289         if (rtm->rtm_dst_len)
290                 RTA_PUT(skb, RTA_DST, 2, dst);
291         rtm->rtm_protocol = fi->fib_protocol;
292         if (fi->fib_priority)
293                 RTA_PUT(skb, RTA_PRIORITY, 4, &fi->fib_priority);
294         if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0)
295                 goto rtattr_failure;
296         if (fi->fib_nhs == 1) {
297                 if (fi->fib_nh->nh_gw)
298                         RTA_PUT(skb, RTA_GATEWAY, 2, &fi->fib_nh->nh_gw);
299                 if (fi->fib_nh->nh_oif)
300                         RTA_PUT(skb, RTA_OIF, sizeof(int), &fi->fib_nh->nh_oif);
301         }
302         if (fi->fib_nhs > 1) {
303                 struct rtnexthop *nhp;
304                 struct rtattr *mp_head;
305                 if (skb_tailroom(skb) <= RTA_SPACE(0))
306                         goto rtattr_failure;
307                 mp_head = (struct rtattr *)skb_put(skb, RTA_SPACE(0));
308
309                 for_nexthops(fi) {
310                         if (skb_tailroom(skb) < RTA_ALIGN(RTA_ALIGN(sizeof(*nhp)) + 4))
311                                 goto rtattr_failure;
312                         nhp = (struct rtnexthop *)skb_put(skb, RTA_ALIGN(sizeof(*nhp)));
313                         nhp->rtnh_flags = nh->nh_flags & 0xFF;
314                         nhp->rtnh_hops = nh->nh_weight - 1;
315                         nhp->rtnh_ifindex = nh->nh_oif;
316                         if (nh->nh_gw)
317                                 RTA_PUT(skb, RTA_GATEWAY, 2, &nh->nh_gw);
318                         nhp->rtnh_len = skb->tail - (unsigned char *)nhp;
319                 } endfor_nexthops(fi);
320                 mp_head->rta_type = RTA_MULTIPATH;
321                 mp_head->rta_len = skb->tail - (u8*)mp_head;
322         }
323
324         nlh->nlmsg_len = skb->tail - b;
325         return skb->len;
326
327
328 nlmsg_failure:
329 rtattr_failure:
330         skb_trim(skb, b - skb->data);
331         return -1;
332 }
333
334
335 static void dn_rtmsg_fib(int event, struct dn_fib_node *f, int z, int tb_id,
336                         struct nlmsghdr *nlh, struct netlink_skb_parms *req)
337 {
338         struct sk_buff *skb;
339         u32 pid = req ? req->pid : 0;
340         int size = NLMSG_SPACE(sizeof(struct rtmsg) + 256);
341
342         skb = alloc_skb(size, GFP_KERNEL);
343         if (!skb)
344                 return;
345
346         if (dn_fib_dump_info(skb, pid, nlh->nlmsg_seq, event, tb_id, 
347                                 f->fn_type, f->fn_scope, &f->fn_key, z, 
348                                 DN_FIB_INFO(f), 0) < 0) {
349                 kfree_skb(skb);
350                 return;
351         }
352         NETLINK_CB(skb).dst_group = RTNLGRP_DECnet_ROUTE;
353         if (nlh->nlmsg_flags & NLM_F_ECHO)
354                 atomic_inc(&skb->users);
355         netlink_broadcast(rtnl, skb, pid, RTNLGRP_DECnet_ROUTE, GFP_KERNEL);
356         if (nlh->nlmsg_flags & NLM_F_ECHO)
357                 netlink_unicast(rtnl, skb, pid, MSG_DONTWAIT);
358 }
359
360 static __inline__ int dn_hash_dump_bucket(struct sk_buff *skb, 
361                                 struct netlink_callback *cb,
362                                 struct dn_fib_table *tb,
363                                 struct dn_zone *dz,
364                                 struct dn_fib_node *f)
365 {
366         int i, s_i;
367
368         s_i = cb->args[3];
369         for(i = 0; f; i++, f = f->fn_next) {
370                 if (i < s_i)
371                         continue;
372                 if (f->fn_state & DN_S_ZOMBIE)
373                         continue;
374                 if (dn_fib_dump_info(skb, NETLINK_CB(cb->skb).pid, 
375                                 cb->nlh->nlmsg_seq,
376                                 RTM_NEWROUTE,
377                                 tb->n, 
378                                 (f->fn_state & DN_S_ZOMBIE) ? 0 : f->fn_type,
379                                 f->fn_scope, &f->fn_key, dz->dz_order, 
380                                 f->fn_info, NLM_F_MULTI) < 0) {
381                         cb->args[3] = i;
382                         return -1;
383                 }
384         }
385         cb->args[3] = i;
386         return skb->len;
387 }
388
389 static __inline__ int dn_hash_dump_zone(struct sk_buff *skb, 
390                                 struct netlink_callback *cb,
391                                 struct dn_fib_table *tb,
392                                 struct dn_zone *dz)
393 {
394         int h, s_h;
395
396         s_h = cb->args[2];
397         for(h = 0; h < dz->dz_divisor; h++) {
398                 if (h < s_h)
399                         continue;
400                 if (h > s_h)
401                         memset(&cb->args[3], 0, sizeof(cb->args) - 3*sizeof(cb->args[0]));
402                 if (dz->dz_hash == NULL || dz->dz_hash[h] == NULL)
403                         continue;
404                 if (dn_hash_dump_bucket(skb, cb, tb, dz, dz->dz_hash[h]) < 0) {
405                         cb->args[2] = h;
406                         return -1;
407                 }
408         }
409         cb->args[2] = h;
410         return skb->len;
411 }
412
413 static int dn_fib_table_dump(struct dn_fib_table *tb, struct sk_buff *skb, 
414                                 struct netlink_callback *cb)
415 {
416         int m, s_m;
417         struct dn_zone *dz;
418         struct dn_hash *table = (struct dn_hash *)tb->data;
419
420         s_m = cb->args[1];
421         read_lock(&dn_fib_tables_lock);
422         for(dz = table->dh_zone_list, m = 0; dz; dz = dz->dz_next, m++) {
423                 if (m < s_m)
424                         continue;
425                 if (m > s_m)
426                         memset(&cb->args[2], 0, sizeof(cb->args) - 2*sizeof(cb->args[0]));
427
428                 if (dn_hash_dump_zone(skb, cb, tb, dz) < 0) {
429                         cb->args[1] = m;
430                         read_unlock(&dn_fib_tables_lock);
431                         return -1;
432                 }
433         }
434         read_unlock(&dn_fib_tables_lock);
435         cb->args[1] = m;
436
437         return skb->len;
438 }
439
440 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)
441 {
442         struct dn_hash *table = (struct dn_hash *)tb->data;
443         struct dn_fib_node *new_f, *f, **fp, **del_fp;
444         struct dn_zone *dz;
445         struct dn_fib_info *fi;
446         int z = r->rtm_dst_len;
447         int type = r->rtm_type;
448         dn_fib_key_t key;
449         int err;
450
451         if (z > 16)
452                 return -EINVAL;
453
454         dz = table->dh_zones[z];
455         if (!dz && !(dz = dn_new_zone(table, z)))
456                 return -ENOBUFS;
457
458         dz_key_0(key);
459         if (rta->rta_dst) {
460                 dn_address dst;
461                 memcpy(&dst, rta->rta_dst, 2);
462                 if (dst & ~DZ_MASK(dz))
463                         return -EINVAL;
464                 key = dz_key(dst, dz);
465         }
466
467         if ((fi = dn_fib_create_info(r, rta, n, &err)) == NULL)
468                 return err;
469
470         if (dz->dz_nent > (dz->dz_divisor << 2) &&
471                         dz->dz_divisor > DN_MAX_DIVISOR &&
472                         (z==16 || (1<<z) > dz->dz_divisor))
473                 dn_rehash_zone(dz);
474
475         fp = dn_chain_p(key, dz);
476
477         DN_FIB_SCAN(f, fp) {
478                 if (dn_key_leq(key, f->fn_key))
479                         break;
480         }
481
482         del_fp = NULL;
483
484         if (f && (f->fn_state & DN_S_ZOMBIE) &&
485                         dn_key_eq(f->fn_key, key)) {
486                 del_fp = fp;
487                 fp = &f->fn_next;
488                 f = *fp;
489                 goto create;
490         }
491
492         DN_FIB_SCAN_KEY(f, fp, key) {
493                 if (fi->fib_priority <= DN_FIB_INFO(f)->fib_priority)
494                         break;
495         }
496
497         if (f && dn_key_eq(f->fn_key, key) &&
498                         fi->fib_priority == DN_FIB_INFO(f)->fib_priority) {
499                 struct dn_fib_node **ins_fp;
500
501                 err = -EEXIST;
502                 if (n->nlmsg_flags & NLM_F_EXCL)
503                         goto out;
504
505                 if (n->nlmsg_flags & NLM_F_REPLACE) {
506                         del_fp = fp;
507                         fp = &f->fn_next;
508                         f = *fp;
509                         goto replace;
510                 }
511
512                 ins_fp = fp;
513                 err = -EEXIST;
514
515                 DN_FIB_SCAN_KEY(f, fp, key) {
516                         if (fi->fib_priority != DN_FIB_INFO(f)->fib_priority)
517                                 break;
518                         if (f->fn_type == type && f->fn_scope == r->rtm_scope
519                                         && DN_FIB_INFO(f) == fi)
520                                 goto out;
521                 }
522
523                 if (!(n->nlmsg_flags & NLM_F_APPEND)) {
524                         fp = ins_fp;
525                         f = *fp;
526                 }
527         }
528
529 create:
530         err = -ENOENT;
531         if (!(n->nlmsg_flags & NLM_F_CREATE))
532                 goto out;
533
534 replace:
535         err = -ENOBUFS;
536         new_f = kmem_cache_alloc(dn_hash_kmem, SLAB_KERNEL);
537         if (new_f == NULL)
538                 goto out;
539
540         memset(new_f, 0, sizeof(struct dn_fib_node));
541
542         new_f->fn_key = key;
543         new_f->fn_type = type;
544         new_f->fn_scope = r->rtm_scope;
545         DN_FIB_INFO(new_f) = fi;
546
547         new_f->fn_next = f;
548         write_lock_bh(&dn_fib_tables_lock);
549         *fp = new_f;
550         write_unlock_bh(&dn_fib_tables_lock);
551         dz->dz_nent++;
552
553         if (del_fp) {
554                 f = *del_fp;
555                 write_lock_bh(&dn_fib_tables_lock);
556                 *del_fp = f->fn_next;
557                 write_unlock_bh(&dn_fib_tables_lock);
558
559                 if (!(f->fn_state & DN_S_ZOMBIE))
560                         dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
561                 if (f->fn_state & DN_S_ACCESSED)
562                         dn_rt_cache_flush(-1);
563                 dn_free_node(f);
564                 dz->dz_nent--;
565         } else {
566                 dn_rt_cache_flush(-1);
567         }
568
569         dn_rtmsg_fib(RTM_NEWROUTE, new_f, z, tb->n, n, req);
570
571         return 0;
572 out:
573         dn_fib_release_info(fi);
574         return err;
575 }
576
577
578 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)
579 {
580         struct dn_hash *table = (struct dn_hash*)tb->data;
581         struct dn_fib_node **fp, **del_fp, *f;
582         int z = r->rtm_dst_len;
583         struct dn_zone *dz;
584         dn_fib_key_t key;
585         int matched;
586
587
588         if (z > 16)
589                 return -EINVAL;
590
591         if ((dz = table->dh_zones[z]) == NULL)
592                 return -ESRCH;
593
594         dz_key_0(key);
595         if (rta->rta_dst) {
596                 dn_address dst;
597                 memcpy(&dst, rta->rta_dst, 2);
598                 if (dst & ~DZ_MASK(dz))
599                         return -EINVAL;
600                 key = dz_key(dst, dz);
601         }
602
603         fp = dn_chain_p(key, dz);
604
605         DN_FIB_SCAN(f, fp) {
606                 if (dn_key_eq(f->fn_key, key))
607                         break;
608                 if (dn_key_leq(key, f->fn_key))
609                         return -ESRCH;
610         }
611
612         matched = 0;
613         del_fp = NULL;
614         DN_FIB_SCAN_KEY(f, fp, key) {
615                 struct dn_fib_info *fi = DN_FIB_INFO(f);
616
617                 if (f->fn_state & DN_S_ZOMBIE)
618                         return -ESRCH;
619
620                 matched++;
621
622                 if (del_fp == NULL &&
623                                 (!r->rtm_type || f->fn_type == r->rtm_type) &&
624                                 (r->rtm_scope == RT_SCOPE_NOWHERE || f->fn_scope == r->rtm_scope) &&
625                                 (!r->rtm_protocol || 
626                                         fi->fib_protocol == r->rtm_protocol) &&
627                                 dn_fib_nh_match(r, n, rta, fi) == 0)
628                         del_fp = fp;
629         }
630
631         if (del_fp) {
632                 f = *del_fp;
633                 dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
634
635                 if (matched != 1) {
636                         write_lock_bh(&dn_fib_tables_lock);
637                         *del_fp = f->fn_next;
638                         write_unlock_bh(&dn_fib_tables_lock);
639
640                         if (f->fn_state & DN_S_ACCESSED)
641                                 dn_rt_cache_flush(-1);
642                         dn_free_node(f);
643                         dz->dz_nent--;
644                 } else {
645                         f->fn_state |= DN_S_ZOMBIE;
646                         if (f->fn_state & DN_S_ACCESSED) {
647                                 f->fn_state &= ~DN_S_ACCESSED;
648                                 dn_rt_cache_flush(-1);
649                         }
650                         if (++dn_fib_hash_zombies > 128)
651                                 dn_fib_flush();
652                 }
653
654                 return 0;
655         }
656
657         return -ESRCH;
658 }
659
660 static inline int dn_flush_list(struct dn_fib_node **fp, int z, struct dn_hash *table)
661 {
662         int found = 0;
663         struct dn_fib_node *f;
664
665         while((f = *fp) != NULL) {
666                 struct dn_fib_info *fi = DN_FIB_INFO(f);
667
668                 if (fi && ((f->fn_state & DN_S_ZOMBIE) || (fi->fib_flags & RTNH_F_DEAD))) {
669                         write_lock_bh(&dn_fib_tables_lock);
670                         *fp = f->fn_next;
671                         write_unlock_bh(&dn_fib_tables_lock);
672
673                         dn_free_node(f);
674                         found++;
675                         continue;
676                 }
677                 fp = &f->fn_next;
678         }
679
680         return found;
681 }
682
683 static int dn_fib_table_flush(struct dn_fib_table *tb)
684 {
685         struct dn_hash *table = (struct dn_hash *)tb->data;
686         struct dn_zone *dz;
687         int found = 0;
688
689         dn_fib_hash_zombies = 0;
690         for(dz = table->dh_zone_list; dz; dz = dz->dz_next) {
691                 int i;
692                 int tmp = 0;
693                 for(i = dz->dz_divisor-1; i >= 0; i--)
694                         tmp += dn_flush_list(&dz->dz_hash[i], dz->dz_order, table);
695                 dz->dz_nent -= tmp;
696                 found += tmp;
697         }
698
699         return found;
700 }
701
702 static int dn_fib_table_lookup(struct dn_fib_table *tb, const struct flowi *flp, struct dn_fib_res *res)
703 {
704         int err;
705         struct dn_zone *dz;
706         struct dn_hash *t = (struct dn_hash *)tb->data;
707
708         read_lock(&dn_fib_tables_lock);
709         for(dz = t->dh_zone_list; dz; dz = dz->dz_next) {
710                 struct dn_fib_node *f;
711                 dn_fib_key_t k = dz_key(flp->fld_dst, dz);
712
713                 for(f = dz_chain(k, dz); f; f = f->fn_next) {
714                         if (!dn_key_eq(k, f->fn_key)) {
715                                 if (dn_key_leq(k, f->fn_key))
716                                         break;
717                                 else
718                                         continue;
719                         }
720
721                         f->fn_state |= DN_S_ACCESSED;
722
723                         if (f->fn_state&DN_S_ZOMBIE)
724                                 continue;
725
726                         if (f->fn_scope < flp->fld_scope)
727                                 continue;
728
729                         err = dn_fib_semantic_match(f->fn_type, DN_FIB_INFO(f), flp, res);
730
731                         if (err == 0) {
732                                 res->type = f->fn_type;
733                                 res->scope = f->fn_scope; 
734                                 res->prefixlen = dz->dz_order;
735                                 goto out;
736                         }
737                         if (err < 0)
738                                 goto out;
739                 }
740         }
741         err = 1;
742 out:
743         read_unlock(&dn_fib_tables_lock);
744         return err;
745 }
746
747
748 struct dn_fib_table *dn_fib_get_table(int n, int create)
749 {
750         struct dn_fib_table *t;
751
752         if (n < RT_TABLE_MIN)
753                 return NULL;
754
755         if (n > RT_TABLE_MAX)
756                 return NULL;
757
758         if (dn_fib_tables[n]) 
759                 return dn_fib_tables[n];
760
761         if (!create)
762                 return NULL;
763
764         if (in_interrupt() && net_ratelimit()) {
765                 printk(KERN_DEBUG "DECnet: BUG! Attempt to create routing table from interrupt\n"); 
766                 return NULL;
767         }
768         if ((t = kmalloc(sizeof(struct dn_fib_table) + sizeof(struct dn_hash), GFP_KERNEL)) == NULL)
769                 return NULL;
770
771         memset(t, 0, sizeof(struct dn_fib_table));
772
773         t->n = n;
774         t->insert = dn_fib_table_insert;
775         t->delete = dn_fib_table_delete;
776         t->lookup = dn_fib_table_lookup;
777         t->flush  = dn_fib_table_flush;
778         t->dump = dn_fib_table_dump;
779         memset(t->data, 0, sizeof(struct dn_hash));
780         dn_fib_tables[n] = t;
781
782         return t;
783 }
784
785 static void dn_fib_del_tree(int n)
786 {
787         struct dn_fib_table *t;
788
789         write_lock(&dn_fib_tables_lock);
790         t = dn_fib_tables[n];
791         dn_fib_tables[n] = NULL;
792         write_unlock(&dn_fib_tables_lock);
793
794         if (t) {
795                 kfree(t);
796         }
797 }
798
799 struct dn_fib_table *dn_fib_empty_table(void)
800 {
801         int id;
802
803         for(id = RT_TABLE_MIN; id <= RT_TABLE_MAX; id++)
804                 if (dn_fib_tables[id] == NULL)
805                         return dn_fib_get_table(id, 1);
806         return NULL;
807 }
808
809 void __init dn_fib_table_init(void)
810 {
811         dn_hash_kmem = kmem_cache_create("dn_fib_info_cache",
812                                         sizeof(struct dn_fib_info),
813                                         0, SLAB_HWCACHE_ALIGN,
814                                         NULL, NULL);
815 }
816
817 void __exit dn_fib_table_cleanup(void)
818 {
819         int i;
820
821         for (i = RT_TABLE_MIN; i <= RT_TABLE_MAX; ++i)
822                 dn_fib_del_tree(i);
823
824         return;
825 }