Merge master.kernel.org:/pub/scm/linux/kernel/git/tmlind/linux-omap-upstream into...
[linux-2.6] / 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/fib_rules.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         __le16                  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 #define DN_FIB_TABLE_HASHSZ 256
79 static struct hlist_head dn_fib_table_hash[DN_FIB_TABLE_HASHSZ];
80 static DEFINE_RWLOCK(dn_fib_tables_lock);
81
82 static kmem_cache_t *dn_hash_kmem __read_mostly;
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 = dn_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(__le16 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 = kcalloc(new_divisor, sizeof(struct dn_fib_node*), GFP_KERNEL);
163         if (ht == NULL)
164                 return;
165
166         write_lock_bh(&dn_fib_tables_lock);
167         old_ht = dz->dz_hash;
168         dz->dz_hash = ht;
169         dz->dz_hashmask = new_hashmask;
170         dz->dz_divisor = new_divisor;
171         dn_rebuild_zone(dz, old_ht, old_divisor);
172         write_unlock_bh(&dn_fib_tables_lock);
173         kfree(old_ht);
174 }
175
176 static void dn_free_node(struct dn_fib_node *f)
177 {
178         dn_fib_release_info(DN_FIB_INFO(f));
179         kmem_cache_free(dn_hash_kmem, f);
180 }
181
182
183 static struct dn_zone *dn_new_zone(struct dn_hash *table, int z)
184 {
185         int i;
186         struct dn_zone *dz = kzalloc(sizeof(struct dn_zone), GFP_KERNEL);
187         if (!dz)
188                 return NULL;
189
190         if (z) {
191                 dz->dz_divisor = 16;
192                 dz->dz_hashmask = 0x0F;
193         } else {
194                 dz->dz_divisor = 1;
195                 dz->dz_hashmask = 0;
196         }
197
198         dz->dz_hash = kcalloc(dz->dz_divisor, sizeof(struct dn_fib_node *), GFP_KERNEL);
199         if (!dz->dz_hash) {
200                 kfree(dz);
201                 return NULL;
202         }
203
204         dz->dz_order = z;
205         dz->dz_mask = dnet_make_mask(z);
206
207         for(i = z + 1; i <= 16; i++)
208                 if (table->dh_zones[i])
209                         break;
210
211         write_lock_bh(&dn_fib_tables_lock);
212         if (i>16) {
213                 dz->dz_next = table->dh_zone_list;
214                 table->dh_zone_list = dz;
215         } else {
216                 dz->dz_next = table->dh_zones[i]->dz_next;
217                 table->dh_zones[i]->dz_next = dz;
218         }
219         table->dh_zones[z] = dz;
220         write_unlock_bh(&dn_fib_tables_lock);
221         return dz;
222 }
223
224
225 static int dn_fib_nh_match(struct rtmsg *r, struct nlmsghdr *nlh, struct dn_kern_rta *rta, struct dn_fib_info *fi)
226 {
227         struct rtnexthop *nhp;
228         int nhlen;
229
230         if (rta->rta_priority && *rta->rta_priority != fi->fib_priority)
231                 return 1;
232
233         if (rta->rta_oif || rta->rta_gw) {
234                 if ((!rta->rta_oif || *rta->rta_oif == fi->fib_nh->nh_oif) &&
235                     (!rta->rta_gw  || memcmp(rta->rta_gw, &fi->fib_nh->nh_gw, 2) == 0))
236                         return 0;
237                 return 1;
238         }
239
240         if (rta->rta_mp == NULL)
241                 return 0;
242
243         nhp = RTA_DATA(rta->rta_mp);
244         nhlen = RTA_PAYLOAD(rta->rta_mp);
245
246         for_nexthops(fi) {
247                 int attrlen = nhlen - sizeof(struct rtnexthop);
248                 __le16 gw;
249
250                 if (attrlen < 0 || (nhlen -= nhp->rtnh_len) < 0)
251                         return -EINVAL;
252                 if (nhp->rtnh_ifindex && nhp->rtnh_ifindex != nh->nh_oif)
253                         return 1;
254                 if (attrlen) {
255                         gw = dn_fib_get_attr16(RTNH_DATA(nhp), attrlen, RTA_GATEWAY);
256
257                         if (gw && gw != nh->nh_gw)
258                                 return 1;
259                 }
260                 nhp = RTNH_NEXT(nhp);
261         } endfor_nexthops(fi);
262
263         return 0;
264 }
265
266 static int dn_fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
267                         u32 tb_id, u8 type, u8 scope, void *dst, int dst_len,
268                         struct dn_fib_info *fi, unsigned int flags)
269 {
270         struct rtmsg *rtm;
271         struct nlmsghdr *nlh;
272         unsigned char *b = skb->tail;
273
274         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*rtm), flags);
275         rtm = NLMSG_DATA(nlh);
276         rtm->rtm_family = AF_DECnet;
277         rtm->rtm_dst_len = dst_len;
278         rtm->rtm_src_len = 0;
279         rtm->rtm_tos = 0;
280         rtm->rtm_table = tb_id;
281         RTA_PUT_U32(skb, RTA_TABLE, tb_id);
282         rtm->rtm_flags = fi->fib_flags;
283         rtm->rtm_scope = scope;
284         rtm->rtm_type  = type;
285         if (rtm->rtm_dst_len)
286                 RTA_PUT(skb, RTA_DST, 2, dst);
287         rtm->rtm_protocol = fi->fib_protocol;
288         if (fi->fib_priority)
289                 RTA_PUT(skb, RTA_PRIORITY, 4, &fi->fib_priority);
290         if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0)
291                 goto rtattr_failure;
292         if (fi->fib_nhs == 1) {
293                 if (fi->fib_nh->nh_gw)
294                         RTA_PUT(skb, RTA_GATEWAY, 2, &fi->fib_nh->nh_gw);
295                 if (fi->fib_nh->nh_oif)
296                         RTA_PUT(skb, RTA_OIF, sizeof(int), &fi->fib_nh->nh_oif);
297         }
298         if (fi->fib_nhs > 1) {
299                 struct rtnexthop *nhp;
300                 struct rtattr *mp_head;
301                 if (skb_tailroom(skb) <= RTA_SPACE(0))
302                         goto rtattr_failure;
303                 mp_head = (struct rtattr *)skb_put(skb, RTA_SPACE(0));
304
305                 for_nexthops(fi) {
306                         if (skb_tailroom(skb) < RTA_ALIGN(RTA_ALIGN(sizeof(*nhp)) + 4))
307                                 goto rtattr_failure;
308                         nhp = (struct rtnexthop *)skb_put(skb, RTA_ALIGN(sizeof(*nhp)));
309                         nhp->rtnh_flags = nh->nh_flags & 0xFF;
310                         nhp->rtnh_hops = nh->nh_weight - 1;
311                         nhp->rtnh_ifindex = nh->nh_oif;
312                         if (nh->nh_gw)
313                                 RTA_PUT(skb, RTA_GATEWAY, 2, &nh->nh_gw);
314                         nhp->rtnh_len = skb->tail - (unsigned char *)nhp;
315                 } endfor_nexthops(fi);
316                 mp_head->rta_type = RTA_MULTIPATH;
317                 mp_head->rta_len = skb->tail - (u8*)mp_head;
318         }
319
320         nlh->nlmsg_len = skb->tail - b;
321         return skb->len;
322
323
324 nlmsg_failure:
325 rtattr_failure:
326         skb_trim(skb, b - skb->data);
327         return -1;
328 }
329
330
331 static void dn_rtmsg_fib(int event, struct dn_fib_node *f, int z, u32 tb_id,
332                         struct nlmsghdr *nlh, struct netlink_skb_parms *req)
333 {
334         struct sk_buff *skb;
335         u32 pid = req ? req->pid : 0;
336         int err = -ENOBUFS;
337
338         skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
339         if (skb == NULL)
340                 goto errout;
341
342         err = dn_fib_dump_info(skb, pid, nlh->nlmsg_seq, event, tb_id,
343                                f->fn_type, f->fn_scope, &f->fn_key, z,
344                                DN_FIB_INFO(f), 0);
345         if (err < 0) {
346                 kfree_skb(skb);
347                 goto errout;
348         }
349
350         err = rtnl_notify(skb, pid, RTNLGRP_DECnet_ROUTE, nlh, GFP_KERNEL);
351 errout:
352         if (err < 0)
353                 rtnl_set_sk_err(RTNLGRP_DECnet_ROUTE, err);
354 }
355
356 static __inline__ int dn_hash_dump_bucket(struct sk_buff *skb, 
357                                 struct netlink_callback *cb,
358                                 struct dn_fib_table *tb,
359                                 struct dn_zone *dz,
360                                 struct dn_fib_node *f)
361 {
362         int i, s_i;
363
364         s_i = cb->args[4];
365         for(i = 0; f; i++, f = f->fn_next) {
366                 if (i < s_i)
367                         continue;
368                 if (f->fn_state & DN_S_ZOMBIE)
369                         continue;
370                 if (dn_fib_dump_info(skb, NETLINK_CB(cb->skb).pid, 
371                                 cb->nlh->nlmsg_seq,
372                                 RTM_NEWROUTE,
373                                 tb->n, 
374                                 (f->fn_state & DN_S_ZOMBIE) ? 0 : f->fn_type,
375                                 f->fn_scope, &f->fn_key, dz->dz_order, 
376                                 f->fn_info, NLM_F_MULTI) < 0) {
377                         cb->args[4] = i;
378                         return -1;
379                 }
380         }
381         cb->args[4] = i;
382         return skb->len;
383 }
384
385 static __inline__ int dn_hash_dump_zone(struct sk_buff *skb, 
386                                 struct netlink_callback *cb,
387                                 struct dn_fib_table *tb,
388                                 struct dn_zone *dz)
389 {
390         int h, s_h;
391
392         s_h = cb->args[3];
393         for(h = 0; h < dz->dz_divisor; h++) {
394                 if (h < s_h)
395                         continue;
396                 if (h > s_h)
397                         memset(&cb->args[4], 0, sizeof(cb->args) - 4*sizeof(cb->args[0]));
398                 if (dz->dz_hash == NULL || dz->dz_hash[h] == NULL)
399                         continue;
400                 if (dn_hash_dump_bucket(skb, cb, tb, dz, dz->dz_hash[h]) < 0) {
401                         cb->args[3] = h;
402                         return -1;
403                 }
404         }
405         cb->args[3] = h;
406         return skb->len;
407 }
408
409 static int dn_fib_table_dump(struct dn_fib_table *tb, struct sk_buff *skb, 
410                                 struct netlink_callback *cb)
411 {
412         int m, s_m;
413         struct dn_zone *dz;
414         struct dn_hash *table = (struct dn_hash *)tb->data;
415
416         s_m = cb->args[2];
417         read_lock(&dn_fib_tables_lock);
418         for(dz = table->dh_zone_list, m = 0; dz; dz = dz->dz_next, m++) {
419                 if (m < s_m)
420                         continue;
421                 if (m > s_m)
422                         memset(&cb->args[3], 0, sizeof(cb->args) - 3*sizeof(cb->args[0]));
423
424                 if (dn_hash_dump_zone(skb, cb, tb, dz) < 0) {
425                         cb->args[2] = m;
426                         read_unlock(&dn_fib_tables_lock);
427                         return -1;
428                 }
429         }
430         read_unlock(&dn_fib_tables_lock);
431         cb->args[2] = m;
432
433         return skb->len;
434 }
435
436 int dn_fib_dump(struct sk_buff *skb, struct netlink_callback *cb)
437 {
438         unsigned int h, s_h;
439         unsigned int e = 0, s_e;
440         struct dn_fib_table *tb;
441         struct hlist_node *node;
442         int dumped = 0;
443
444         if (NLMSG_PAYLOAD(cb->nlh, 0) >= sizeof(struct rtmsg) &&
445                 ((struct rtmsg *)NLMSG_DATA(cb->nlh))->rtm_flags&RTM_F_CLONED)
446                         return dn_cache_dump(skb, cb);
447
448         s_h = cb->args[0];
449         s_e = cb->args[1];
450
451         for (h = s_h; h < DN_FIB_TABLE_HASHSZ; h++, s_h = 0) {
452                 e = 0;
453                 hlist_for_each_entry(tb, node, &dn_fib_table_hash[h], hlist) {
454                         if (e < s_e)
455                                 goto next;
456                         if (dumped)
457                                 memset(&cb->args[2], 0, sizeof(cb->args) -
458                                                  2 * sizeof(cb->args[0]));
459                         if (tb->dump(tb, skb, cb) < 0)
460                                 goto out;
461                         dumped = 1;
462 next:
463                         e++;
464                 }
465         }
466 out:
467         cb->args[1] = e;
468         cb->args[0] = h;
469
470         return skb->len;
471 }
472
473 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)
474 {
475         struct dn_hash *table = (struct dn_hash *)tb->data;
476         struct dn_fib_node *new_f, *f, **fp, **del_fp;
477         struct dn_zone *dz;
478         struct dn_fib_info *fi;
479         int z = r->rtm_dst_len;
480         int type = r->rtm_type;
481         dn_fib_key_t key;
482         int err;
483
484         if (z > 16)
485                 return -EINVAL;
486
487         dz = table->dh_zones[z];
488         if (!dz && !(dz = dn_new_zone(table, z)))
489                 return -ENOBUFS;
490
491         dz_key_0(key);
492         if (rta->rta_dst) {
493                 __le16 dst;
494                 memcpy(&dst, rta->rta_dst, 2);
495                 if (dst & ~DZ_MASK(dz))
496                         return -EINVAL;
497                 key = dz_key(dst, dz);
498         }
499
500         if ((fi = dn_fib_create_info(r, rta, n, &err)) == NULL)
501                 return err;
502
503         if (dz->dz_nent > (dz->dz_divisor << 2) &&
504                         dz->dz_divisor > DN_MAX_DIVISOR &&
505                         (z==16 || (1<<z) > dz->dz_divisor))
506                 dn_rehash_zone(dz);
507
508         fp = dn_chain_p(key, dz);
509
510         DN_FIB_SCAN(f, fp) {
511                 if (dn_key_leq(key, f->fn_key))
512                         break;
513         }
514
515         del_fp = NULL;
516
517         if (f && (f->fn_state & DN_S_ZOMBIE) &&
518                         dn_key_eq(f->fn_key, key)) {
519                 del_fp = fp;
520                 fp = &f->fn_next;
521                 f = *fp;
522                 goto create;
523         }
524
525         DN_FIB_SCAN_KEY(f, fp, key) {
526                 if (fi->fib_priority <= DN_FIB_INFO(f)->fib_priority)
527                         break;
528         }
529
530         if (f && dn_key_eq(f->fn_key, key) &&
531                         fi->fib_priority == DN_FIB_INFO(f)->fib_priority) {
532                 struct dn_fib_node **ins_fp;
533
534                 err = -EEXIST;
535                 if (n->nlmsg_flags & NLM_F_EXCL)
536                         goto out;
537
538                 if (n->nlmsg_flags & NLM_F_REPLACE) {
539                         del_fp = fp;
540                         fp = &f->fn_next;
541                         f = *fp;
542                         goto replace;
543                 }
544
545                 ins_fp = fp;
546                 err = -EEXIST;
547
548                 DN_FIB_SCAN_KEY(f, fp, key) {
549                         if (fi->fib_priority != DN_FIB_INFO(f)->fib_priority)
550                                 break;
551                         if (f->fn_type == type && f->fn_scope == r->rtm_scope
552                                         && DN_FIB_INFO(f) == fi)
553                                 goto out;
554                 }
555
556                 if (!(n->nlmsg_flags & NLM_F_APPEND)) {
557                         fp = ins_fp;
558                         f = *fp;
559                 }
560         }
561
562 create:
563         err = -ENOENT;
564         if (!(n->nlmsg_flags & NLM_F_CREATE))
565                 goto out;
566
567 replace:
568         err = -ENOBUFS;
569         new_f = kmem_cache_alloc(dn_hash_kmem, SLAB_KERNEL);
570         if (new_f == NULL)
571                 goto out;
572
573         memset(new_f, 0, sizeof(struct dn_fib_node));
574
575         new_f->fn_key = key;
576         new_f->fn_type = type;
577         new_f->fn_scope = r->rtm_scope;
578         DN_FIB_INFO(new_f) = fi;
579
580         new_f->fn_next = f;
581         write_lock_bh(&dn_fib_tables_lock);
582         *fp = new_f;
583         write_unlock_bh(&dn_fib_tables_lock);
584         dz->dz_nent++;
585
586         if (del_fp) {
587                 f = *del_fp;
588                 write_lock_bh(&dn_fib_tables_lock);
589                 *del_fp = f->fn_next;
590                 write_unlock_bh(&dn_fib_tables_lock);
591
592                 if (!(f->fn_state & DN_S_ZOMBIE))
593                         dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
594                 if (f->fn_state & DN_S_ACCESSED)
595                         dn_rt_cache_flush(-1);
596                 dn_free_node(f);
597                 dz->dz_nent--;
598         } else {
599                 dn_rt_cache_flush(-1);
600         }
601
602         dn_rtmsg_fib(RTM_NEWROUTE, new_f, z, tb->n, n, req);
603
604         return 0;
605 out:
606         dn_fib_release_info(fi);
607         return err;
608 }
609
610
611 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)
612 {
613         struct dn_hash *table = (struct dn_hash*)tb->data;
614         struct dn_fib_node **fp, **del_fp, *f;
615         int z = r->rtm_dst_len;
616         struct dn_zone *dz;
617         dn_fib_key_t key;
618         int matched;
619
620
621         if (z > 16)
622                 return -EINVAL;
623
624         if ((dz = table->dh_zones[z]) == NULL)
625                 return -ESRCH;
626
627         dz_key_0(key);
628         if (rta->rta_dst) {
629                 __le16 dst;
630                 memcpy(&dst, rta->rta_dst, 2);
631                 if (dst & ~DZ_MASK(dz))
632                         return -EINVAL;
633                 key = dz_key(dst, dz);
634         }
635
636         fp = dn_chain_p(key, dz);
637
638         DN_FIB_SCAN(f, fp) {
639                 if (dn_key_eq(f->fn_key, key))
640                         break;
641                 if (dn_key_leq(key, f->fn_key))
642                         return -ESRCH;
643         }
644
645         matched = 0;
646         del_fp = NULL;
647         DN_FIB_SCAN_KEY(f, fp, key) {
648                 struct dn_fib_info *fi = DN_FIB_INFO(f);
649
650                 if (f->fn_state & DN_S_ZOMBIE)
651                         return -ESRCH;
652
653                 matched++;
654
655                 if (del_fp == NULL &&
656                                 (!r->rtm_type || f->fn_type == r->rtm_type) &&
657                                 (r->rtm_scope == RT_SCOPE_NOWHERE || f->fn_scope == r->rtm_scope) &&
658                                 (!r->rtm_protocol || 
659                                         fi->fib_protocol == r->rtm_protocol) &&
660                                 dn_fib_nh_match(r, n, rta, fi) == 0)
661                         del_fp = fp;
662         }
663
664         if (del_fp) {
665                 f = *del_fp;
666                 dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
667
668                 if (matched != 1) {
669                         write_lock_bh(&dn_fib_tables_lock);
670                         *del_fp = f->fn_next;
671                         write_unlock_bh(&dn_fib_tables_lock);
672
673                         if (f->fn_state & DN_S_ACCESSED)
674                                 dn_rt_cache_flush(-1);
675                         dn_free_node(f);
676                         dz->dz_nent--;
677                 } else {
678                         f->fn_state |= DN_S_ZOMBIE;
679                         if (f->fn_state & DN_S_ACCESSED) {
680                                 f->fn_state &= ~DN_S_ACCESSED;
681                                 dn_rt_cache_flush(-1);
682                         }
683                         if (++dn_fib_hash_zombies > 128)
684                                 dn_fib_flush();
685                 }
686
687                 return 0;
688         }
689
690         return -ESRCH;
691 }
692
693 static inline int dn_flush_list(struct dn_fib_node **fp, int z, struct dn_hash *table)
694 {
695         int found = 0;
696         struct dn_fib_node *f;
697
698         while((f = *fp) != NULL) {
699                 struct dn_fib_info *fi = DN_FIB_INFO(f);
700
701                 if (fi && ((f->fn_state & DN_S_ZOMBIE) || (fi->fib_flags & RTNH_F_DEAD))) {
702                         write_lock_bh(&dn_fib_tables_lock);
703                         *fp = f->fn_next;
704                         write_unlock_bh(&dn_fib_tables_lock);
705
706                         dn_free_node(f);
707                         found++;
708                         continue;
709                 }
710                 fp = &f->fn_next;
711         }
712
713         return found;
714 }
715
716 static int dn_fib_table_flush(struct dn_fib_table *tb)
717 {
718         struct dn_hash *table = (struct dn_hash *)tb->data;
719         struct dn_zone *dz;
720         int found = 0;
721
722         dn_fib_hash_zombies = 0;
723         for(dz = table->dh_zone_list; dz; dz = dz->dz_next) {
724                 int i;
725                 int tmp = 0;
726                 for(i = dz->dz_divisor-1; i >= 0; i--)
727                         tmp += dn_flush_list(&dz->dz_hash[i], dz->dz_order, table);
728                 dz->dz_nent -= tmp;
729                 found += tmp;
730         }
731
732         return found;
733 }
734
735 static int dn_fib_table_lookup(struct dn_fib_table *tb, const struct flowi *flp, struct dn_fib_res *res)
736 {
737         int err;
738         struct dn_zone *dz;
739         struct dn_hash *t = (struct dn_hash *)tb->data;
740
741         read_lock(&dn_fib_tables_lock);
742         for(dz = t->dh_zone_list; dz; dz = dz->dz_next) {
743                 struct dn_fib_node *f;
744                 dn_fib_key_t k = dz_key(flp->fld_dst, dz);
745
746                 for(f = dz_chain(k, dz); f; f = f->fn_next) {
747                         if (!dn_key_eq(k, f->fn_key)) {
748                                 if (dn_key_leq(k, f->fn_key))
749                                         break;
750                                 else
751                                         continue;
752                         }
753
754                         f->fn_state |= DN_S_ACCESSED;
755
756                         if (f->fn_state&DN_S_ZOMBIE)
757                                 continue;
758
759                         if (f->fn_scope < flp->fld_scope)
760                                 continue;
761
762                         err = dn_fib_semantic_match(f->fn_type, DN_FIB_INFO(f), flp, res);
763
764                         if (err == 0) {
765                                 res->type = f->fn_type;
766                                 res->scope = f->fn_scope; 
767                                 res->prefixlen = dz->dz_order;
768                                 goto out;
769                         }
770                         if (err < 0)
771                                 goto out;
772                 }
773         }
774         err = 1;
775 out:
776         read_unlock(&dn_fib_tables_lock);
777         return err;
778 }
779
780
781 struct dn_fib_table *dn_fib_get_table(u32 n, int create)
782 {
783         struct dn_fib_table *t;
784         struct hlist_node *node;
785         unsigned int h;
786
787         if (n < RT_TABLE_MIN)
788                 return NULL;
789
790         if (n > RT_TABLE_MAX)
791                 return NULL;
792
793         h = n & (DN_FIB_TABLE_HASHSZ - 1);
794         rcu_read_lock();
795         hlist_for_each_entry_rcu(t, node, &dn_fib_table_hash[h], hlist) {
796                 if (t->n == n) {
797                         rcu_read_unlock();
798                         return t;
799                 }
800         }
801         rcu_read_unlock();
802
803         if (!create)
804                 return NULL;
805
806         if (in_interrupt() && net_ratelimit()) {
807                 printk(KERN_DEBUG "DECnet: BUG! Attempt to create routing table from interrupt\n"); 
808                 return NULL;
809         }
810         if ((t = kmalloc(sizeof(struct dn_fib_table) + sizeof(struct dn_hash), GFP_KERNEL)) == NULL)
811                 return NULL;
812
813         memset(t, 0, sizeof(struct dn_fib_table));
814
815         t->n = n;
816         t->insert = dn_fib_table_insert;
817         t->delete = dn_fib_table_delete;
818         t->lookup = dn_fib_table_lookup;
819         t->flush  = dn_fib_table_flush;
820         t->dump = dn_fib_table_dump;
821         memset(t->data, 0, sizeof(struct dn_hash));
822         hlist_add_head_rcu(&t->hlist, &dn_fib_table_hash[h]);
823
824         return t;
825 }
826
827 struct dn_fib_table *dn_fib_empty_table(void)
828 {
829         u32 id;
830
831         for(id = RT_TABLE_MIN; id <= RT_TABLE_MAX; id++)
832                 if (dn_fib_get_table(id, 0) == NULL)
833                         return dn_fib_get_table(id, 1);
834         return NULL;
835 }
836
837 void dn_fib_flush(void)
838 {
839         int flushed = 0;
840         struct dn_fib_table *tb;
841         struct hlist_node *node;
842         unsigned int h;
843
844         for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
845                 hlist_for_each_entry(tb, node, &dn_fib_table_hash[h], hlist)
846                         flushed += tb->flush(tb);
847         }
848
849         if (flushed)
850                 dn_rt_cache_flush(-1);
851 }
852
853 void __init dn_fib_table_init(void)
854 {
855         dn_hash_kmem = kmem_cache_create("dn_fib_info_cache",
856                                         sizeof(struct dn_fib_info),
857                                         0, SLAB_HWCACHE_ALIGN,
858                                         NULL, NULL);
859 }
860
861 void __exit dn_fib_table_cleanup(void)
862 {
863         struct dn_fib_table *t;
864         struct hlist_node *node, *next;
865         unsigned int h;
866
867         write_lock(&dn_fib_tables_lock);
868         for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
869                 hlist_for_each_entry_safe(t, node, next, &dn_fib_table_hash[h],
870                                           hlist) {
871                         hlist_del(&t->hlist);
872                         kfree(t);
873                 }
874         }
875         write_unlock(&dn_fib_tables_lock);
876 }