Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
[linux-2.6-microblaze.git] / net / decnet / dn_table.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * DECnet       An implementation of the DECnet protocol suite for the LINUX
4  *              operating system.  DECnet is implemented using the  BSD Socket
5  *              interface as the means of communication with the user level.
6  *
7  *              DECnet Routing Forwarding Information Base (Routing Tables)
8  *
9  * Author:      Steve Whitehouse <SteveW@ACM.org>
10  *              Mostly copied from the IPv4 routing code
11  *
12  *
13  * Changes:
14  *
15  */
16 #include <linux/string.h>
17 #include <linux/net.h>
18 #include <linux/socket.h>
19 #include <linux/slab.h>
20 #include <linux/sockios.h>
21 #include <linux/init.h>
22 #include <linux/skbuff.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 <linux/atomic.h>
29 #include <linux/uaccess.h>
30 #include <linux/route.h> /* RTF_xxx */
31 #include <net/neighbour.h>
32 #include <net/netlink.h>
33 #include <net/tcp.h>
34 #include <net/dst.h>
35 #include <net/flow.h>
36 #include <net/fib_rules.h>
37 #include <net/dn.h>
38 #include <net/dn_route.h>
39 #include <net/dn_fib.h>
40 #include <net/dn_neigh.h>
41 #include <net/dn_dev.h>
42
43 struct dn_zone
44 {
45         struct dn_zone          *dz_next;
46         struct dn_fib_node      **dz_hash;
47         int                     dz_nent;
48         int                     dz_divisor;
49         u32                     dz_hashmask;
50 #define DZ_HASHMASK(dz) ((dz)->dz_hashmask)
51         int                     dz_order;
52         __le16                  dz_mask;
53 #define DZ_MASK(dz)     ((dz)->dz_mask)
54 };
55
56 struct dn_hash
57 {
58         struct dn_zone  *dh_zones[17];
59         struct dn_zone  *dh_zone_list;
60 };
61
62 #define dz_key_0(key)           ((key).datum = 0)
63
64 #define for_nexthops(fi) { int nhsel; const struct dn_fib_nh *nh;\
65         for(nhsel = 0, nh = (fi)->fib_nh; nhsel < (fi)->fib_nhs; nh++, nhsel++)
66
67 #define endfor_nexthops(fi) }
68
69 #define DN_MAX_DIVISOR 1024
70 #define DN_S_ZOMBIE 1
71 #define DN_S_ACCESSED 2
72
73 #define DN_FIB_SCAN(f, fp) \
74 for( ; ((f) = *(fp)) != NULL; (fp) = &(f)->fn_next)
75
76 #define DN_FIB_SCAN_KEY(f, fp, key) \
77 for( ; ((f) = *(fp)) != NULL && dn_key_eq((f)->fn_key, (key)); (fp) = &(f)->fn_next)
78
79 #define RT_TABLE_MIN 1
80 #define DN_FIB_TABLE_HASHSZ 256
81 static struct hlist_head dn_fib_table_hash[DN_FIB_TABLE_HASHSZ];
82 static DEFINE_RWLOCK(dn_fib_tables_lock);
83
84 static struct kmem_cache *dn_hash_kmem __read_mostly;
85 static int dn_fib_hash_zombies;
86
87 static inline dn_fib_idx_t dn_hash(dn_fib_key_t key, struct dn_zone *dz)
88 {
89         u16 h = le16_to_cpu(key.datum)>>(16 - dz->dz_order);
90         h ^= (h >> 10);
91         h ^= (h >> 6);
92         h &= DZ_HASHMASK(dz);
93         return *(dn_fib_idx_t *)&h;
94 }
95
96 static inline dn_fib_key_t dz_key(__le16 dst, struct dn_zone *dz)
97 {
98         dn_fib_key_t k;
99         k.datum = dst & DZ_MASK(dz);
100         return k;
101 }
102
103 static inline struct dn_fib_node **dn_chain_p(dn_fib_key_t key, struct dn_zone *dz)
104 {
105         return &dz->dz_hash[dn_hash(key, dz).datum];
106 }
107
108 static inline struct dn_fib_node *dz_chain(dn_fib_key_t key, struct dn_zone *dz)
109 {
110         return dz->dz_hash[dn_hash(key, dz).datum];
111 }
112
113 static inline int dn_key_eq(dn_fib_key_t a, dn_fib_key_t b)
114 {
115         return a.datum == b.datum;
116 }
117
118 static inline int dn_key_leq(dn_fib_key_t a, dn_fib_key_t b)
119 {
120         return a.datum <= b.datum;
121 }
122
123 static inline void dn_rebuild_zone(struct dn_zone *dz,
124                                    struct dn_fib_node **old_ht,
125                                    int old_divisor)
126 {
127         struct dn_fib_node *f, **fp, *next;
128         int i;
129
130         for(i = 0; i < old_divisor; i++) {
131                 for(f = old_ht[i]; f; f = next) {
132                         next = f->fn_next;
133                         for(fp = dn_chain_p(f->fn_key, dz);
134                                 *fp && dn_key_leq((*fp)->fn_key, f->fn_key);
135                                 fp = &(*fp)->fn_next)
136                                 /* NOTHING */;
137                         f->fn_next = *fp;
138                         *fp = f;
139                 }
140         }
141 }
142
143 static void dn_rehash_zone(struct dn_zone *dz)
144 {
145         struct dn_fib_node **ht, **old_ht;
146         int old_divisor, new_divisor;
147         u32 new_hashmask;
148
149         old_divisor = dz->dz_divisor;
150
151         switch (old_divisor) {
152         case 16:
153                 new_divisor = 256;
154                 new_hashmask = 0xFF;
155                 break;
156         default:
157                 printk(KERN_DEBUG "DECnet: dn_rehash_zone: BUG! %d\n",
158                        old_divisor);
159                 /* fall through */
160         case 256:
161                 new_divisor = 1024;
162                 new_hashmask = 0x3FF;
163                 break;
164         }
165
166         ht = kcalloc(new_divisor, sizeof(struct dn_fib_node*), GFP_KERNEL);
167         if (ht == NULL)
168                 return;
169
170         write_lock_bh(&dn_fib_tables_lock);
171         old_ht = dz->dz_hash;
172         dz->dz_hash = ht;
173         dz->dz_hashmask = new_hashmask;
174         dz->dz_divisor = new_divisor;
175         dn_rebuild_zone(dz, old_ht, old_divisor);
176         write_unlock_bh(&dn_fib_tables_lock);
177         kfree(old_ht);
178 }
179
180 static void dn_free_node(struct dn_fib_node *f)
181 {
182         dn_fib_release_info(DN_FIB_INFO(f));
183         kmem_cache_free(dn_hash_kmem, f);
184 }
185
186
187 static struct dn_zone *dn_new_zone(struct dn_hash *table, int z)
188 {
189         int i;
190         struct dn_zone *dz = kzalloc(sizeof(struct dn_zone), GFP_KERNEL);
191         if (!dz)
192                 return NULL;
193
194         if (z) {
195                 dz->dz_divisor = 16;
196                 dz->dz_hashmask = 0x0F;
197         } else {
198                 dz->dz_divisor = 1;
199                 dz->dz_hashmask = 0;
200         }
201
202         dz->dz_hash = kcalloc(dz->dz_divisor, sizeof(struct dn_fib_node *), GFP_KERNEL);
203         if (!dz->dz_hash) {
204                 kfree(dz);
205                 return NULL;
206         }
207
208         dz->dz_order = z;
209         dz->dz_mask = dnet_make_mask(z);
210
211         for(i = z + 1; i <= 16; i++)
212                 if (table->dh_zones[i])
213                         break;
214
215         write_lock_bh(&dn_fib_tables_lock);
216         if (i>16) {
217                 dz->dz_next = table->dh_zone_list;
218                 table->dh_zone_list = dz;
219         } else {
220                 dz->dz_next = table->dh_zones[i]->dz_next;
221                 table->dh_zones[i]->dz_next = dz;
222         }
223         table->dh_zones[z] = dz;
224         write_unlock_bh(&dn_fib_tables_lock);
225         return dz;
226 }
227
228
229 static int dn_fib_nh_match(struct rtmsg *r, struct nlmsghdr *nlh, struct nlattr *attrs[], struct dn_fib_info *fi)
230 {
231         struct rtnexthop *nhp;
232         int nhlen;
233
234         if (attrs[RTA_PRIORITY] &&
235             nla_get_u32(attrs[RTA_PRIORITY]) != fi->fib_priority)
236                 return 1;
237
238         if (attrs[RTA_OIF] || attrs[RTA_GATEWAY]) {
239                 if ((!attrs[RTA_OIF] || nla_get_u32(attrs[RTA_OIF]) == fi->fib_nh->nh_oif) &&
240                     (!attrs[RTA_GATEWAY]  || nla_get_le16(attrs[RTA_GATEWAY]) != fi->fib_nh->nh_gw))
241                         return 0;
242                 return 1;
243         }
244
245         if (!attrs[RTA_MULTIPATH])
246                 return 0;
247
248         nhp = nla_data(attrs[RTA_MULTIPATH]);
249         nhlen = nla_len(attrs[RTA_MULTIPATH]);
250
251         for_nexthops(fi) {
252                 int attrlen = nhlen - sizeof(struct rtnexthop);
253                 __le16 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                         struct nlattr *gw_attr;
261
262                         gw_attr = nla_find((struct nlattr *) (nhp + 1), attrlen, RTA_GATEWAY);
263                         gw = gw_attr ? nla_get_le16(gw_attr) : 0;
264
265                         if (gw && gw != nh->nh_gw)
266                                 return 1;
267                 }
268                 nhp = RTNH_NEXT(nhp);
269         } endfor_nexthops(fi);
270
271         return 0;
272 }
273
274 static inline size_t dn_fib_nlmsg_size(struct dn_fib_info *fi)
275 {
276         size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg))
277                          + nla_total_size(4) /* RTA_TABLE */
278                          + nla_total_size(2) /* RTA_DST */
279                          + nla_total_size(4) /* RTA_PRIORITY */
280                          + nla_total_size(TCP_CA_NAME_MAX); /* RTAX_CC_ALGO */
281
282         /* space for nested metrics */
283         payload += nla_total_size((RTAX_MAX * nla_total_size(4)));
284
285         if (fi->fib_nhs) {
286                 /* Also handles the special case fib_nhs == 1 */
287
288                 /* each nexthop is packed in an attribute */
289                 size_t nhsize = nla_total_size(sizeof(struct rtnexthop));
290
291                 /* may contain a gateway attribute */
292                 nhsize += nla_total_size(4);
293
294                 /* all nexthops are packed in a nested attribute */
295                 payload += nla_total_size(fi->fib_nhs * nhsize);
296         }
297
298         return payload;
299 }
300
301 static int dn_fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event,
302                         u32 tb_id, u8 type, u8 scope, void *dst, int dst_len,
303                         struct dn_fib_info *fi, unsigned int flags)
304 {
305         struct rtmsg *rtm;
306         struct nlmsghdr *nlh;
307
308         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags);
309         if (!nlh)
310                 return -EMSGSIZE;
311
312         rtm = nlmsg_data(nlh);
313         rtm->rtm_family = AF_DECnet;
314         rtm->rtm_dst_len = dst_len;
315         rtm->rtm_src_len = 0;
316         rtm->rtm_tos = 0;
317         rtm->rtm_table = tb_id;
318         rtm->rtm_flags = fi->fib_flags;
319         rtm->rtm_scope = scope;
320         rtm->rtm_type  = type;
321         rtm->rtm_protocol = fi->fib_protocol;
322
323         if (nla_put_u32(skb, RTA_TABLE, tb_id) < 0)
324                 goto errout;
325
326         if (rtm->rtm_dst_len &&
327             nla_put(skb, RTA_DST, 2, dst) < 0)
328                 goto errout;
329
330         if (fi->fib_priority &&
331             nla_put_u32(skb, RTA_PRIORITY, fi->fib_priority) < 0)
332                 goto errout;
333
334         if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0)
335                 goto errout;
336
337         if (fi->fib_nhs == 1) {
338                 if (fi->fib_nh->nh_gw &&
339                     nla_put_le16(skb, RTA_GATEWAY, fi->fib_nh->nh_gw) < 0)
340                         goto errout;
341
342                 if (fi->fib_nh->nh_oif &&
343                     nla_put_u32(skb, RTA_OIF, fi->fib_nh->nh_oif) < 0)
344                         goto errout;
345         }
346
347         if (fi->fib_nhs > 1) {
348                 struct rtnexthop *nhp;
349                 struct nlattr *mp_head;
350
351                 if (!(mp_head = nla_nest_start(skb, RTA_MULTIPATH)))
352                         goto errout;
353
354                 for_nexthops(fi) {
355                         if (!(nhp = nla_reserve_nohdr(skb, sizeof(*nhp))))
356                                 goto errout;
357
358                         nhp->rtnh_flags = nh->nh_flags & 0xFF;
359                         nhp->rtnh_hops = nh->nh_weight - 1;
360                         nhp->rtnh_ifindex = nh->nh_oif;
361
362                         if (nh->nh_gw &&
363                             nla_put_le16(skb, RTA_GATEWAY, nh->nh_gw) < 0)
364                                 goto errout;
365
366                         nhp->rtnh_len = skb_tail_pointer(skb) - (unsigned char *)nhp;
367                 } endfor_nexthops(fi);
368
369                 nla_nest_end(skb, mp_head);
370         }
371
372         nlmsg_end(skb, nlh);
373         return 0;
374
375 errout:
376         nlmsg_cancel(skb, nlh);
377         return -EMSGSIZE;
378 }
379
380
381 static void dn_rtmsg_fib(int event, struct dn_fib_node *f, int z, u32 tb_id,
382                         struct nlmsghdr *nlh, struct netlink_skb_parms *req)
383 {
384         struct sk_buff *skb;
385         u32 portid = req ? req->portid : 0;
386         int err = -ENOBUFS;
387
388         skb = nlmsg_new(dn_fib_nlmsg_size(DN_FIB_INFO(f)), GFP_KERNEL);
389         if (skb == NULL)
390                 goto errout;
391
392         err = dn_fib_dump_info(skb, portid, nlh->nlmsg_seq, event, tb_id,
393                                f->fn_type, f->fn_scope, &f->fn_key, z,
394                                DN_FIB_INFO(f), 0);
395         if (err < 0) {
396                 /* -EMSGSIZE implies BUG in dn_fib_nlmsg_size() */
397                 WARN_ON(err == -EMSGSIZE);
398                 kfree_skb(skb);
399                 goto errout;
400         }
401         rtnl_notify(skb, &init_net, portid, RTNLGRP_DECnet_ROUTE, nlh, GFP_KERNEL);
402         return;
403 errout:
404         if (err < 0)
405                 rtnl_set_sk_err(&init_net, RTNLGRP_DECnet_ROUTE, err);
406 }
407
408 static __inline__ int dn_hash_dump_bucket(struct sk_buff *skb,
409                                 struct netlink_callback *cb,
410                                 struct dn_fib_table *tb,
411                                 struct dn_zone *dz,
412                                 struct dn_fib_node *f)
413 {
414         int i, s_i;
415
416         s_i = cb->args[4];
417         for(i = 0; f; i++, f = f->fn_next) {
418                 if (i < s_i)
419                         continue;
420                 if (f->fn_state & DN_S_ZOMBIE)
421                         continue;
422                 if (dn_fib_dump_info(skb, NETLINK_CB(cb->skb).portid,
423                                 cb->nlh->nlmsg_seq,
424                                 RTM_NEWROUTE,
425                                 tb->n,
426                                 (f->fn_state & DN_S_ZOMBIE) ? 0 : f->fn_type,
427                                 f->fn_scope, &f->fn_key, dz->dz_order,
428                                 f->fn_info, NLM_F_MULTI) < 0) {
429                         cb->args[4] = i;
430                         return -1;
431                 }
432         }
433         cb->args[4] = i;
434         return skb->len;
435 }
436
437 static __inline__ int dn_hash_dump_zone(struct sk_buff *skb,
438                                 struct netlink_callback *cb,
439                                 struct dn_fib_table *tb,
440                                 struct dn_zone *dz)
441 {
442         int h, s_h;
443
444         s_h = cb->args[3];
445         for(h = 0; h < dz->dz_divisor; h++) {
446                 if (h < s_h)
447                         continue;
448                 if (h > s_h)
449                         memset(&cb->args[4], 0, sizeof(cb->args) - 4*sizeof(cb->args[0]));
450                 if (dz->dz_hash == NULL || dz->dz_hash[h] == NULL)
451                         continue;
452                 if (dn_hash_dump_bucket(skb, cb, tb, dz, dz->dz_hash[h]) < 0) {
453                         cb->args[3] = h;
454                         return -1;
455                 }
456         }
457         cb->args[3] = h;
458         return skb->len;
459 }
460
461 static int dn_fib_table_dump(struct dn_fib_table *tb, struct sk_buff *skb,
462                                 struct netlink_callback *cb)
463 {
464         int m, s_m;
465         struct dn_zone *dz;
466         struct dn_hash *table = (struct dn_hash *)tb->data;
467
468         s_m = cb->args[2];
469         read_lock(&dn_fib_tables_lock);
470         for(dz = table->dh_zone_list, m = 0; dz; dz = dz->dz_next, m++) {
471                 if (m < s_m)
472                         continue;
473                 if (m > s_m)
474                         memset(&cb->args[3], 0, sizeof(cb->args) - 3*sizeof(cb->args[0]));
475
476                 if (dn_hash_dump_zone(skb, cb, tb, dz) < 0) {
477                         cb->args[2] = m;
478                         read_unlock(&dn_fib_tables_lock);
479                         return -1;
480                 }
481         }
482         read_unlock(&dn_fib_tables_lock);
483         cb->args[2] = m;
484
485         return skb->len;
486 }
487
488 int dn_fib_dump(struct sk_buff *skb, struct netlink_callback *cb)
489 {
490         struct net *net = sock_net(skb->sk);
491         unsigned int h, s_h;
492         unsigned int e = 0, s_e;
493         struct dn_fib_table *tb;
494         int dumped = 0;
495
496         if (!net_eq(net, &init_net))
497                 return 0;
498
499         if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
500                 ((struct rtmsg *)nlmsg_data(cb->nlh))->rtm_flags&RTM_F_CLONED)
501                         return dn_cache_dump(skb, cb);
502
503         s_h = cb->args[0];
504         s_e = cb->args[1];
505
506         for (h = s_h; h < DN_FIB_TABLE_HASHSZ; h++, s_h = 0) {
507                 e = 0;
508                 hlist_for_each_entry(tb, &dn_fib_table_hash[h], hlist) {
509                         if (e < s_e)
510                                 goto next;
511                         if (dumped)
512                                 memset(&cb->args[2], 0, sizeof(cb->args) -
513                                                  2 * sizeof(cb->args[0]));
514                         if (tb->dump(tb, skb, cb) < 0)
515                                 goto out;
516                         dumped = 1;
517 next:
518                         e++;
519                 }
520         }
521 out:
522         cb->args[1] = e;
523         cb->args[0] = h;
524
525         return skb->len;
526 }
527
528 static int dn_fib_table_insert(struct dn_fib_table *tb, struct rtmsg *r, struct nlattr *attrs[],
529                                struct nlmsghdr *n, struct netlink_skb_parms *req)
530 {
531         struct dn_hash *table = (struct dn_hash *)tb->data;
532         struct dn_fib_node *new_f, *f, **fp, **del_fp;
533         struct dn_zone *dz;
534         struct dn_fib_info *fi;
535         int z = r->rtm_dst_len;
536         int type = r->rtm_type;
537         dn_fib_key_t key;
538         int err;
539
540         if (z > 16)
541                 return -EINVAL;
542
543         dz = table->dh_zones[z];
544         if (!dz && !(dz = dn_new_zone(table, z)))
545                 return -ENOBUFS;
546
547         dz_key_0(key);
548         if (attrs[RTA_DST]) {
549                 __le16 dst = nla_get_le16(attrs[RTA_DST]);
550                 if (dst & ~DZ_MASK(dz))
551                         return -EINVAL;
552                 key = dz_key(dst, dz);
553         }
554
555         if ((fi = dn_fib_create_info(r, attrs, n, &err)) == NULL)
556                 return err;
557
558         if (dz->dz_nent > (dz->dz_divisor << 2) &&
559                         dz->dz_divisor > DN_MAX_DIVISOR &&
560                         (z==16 || (1<<z) > dz->dz_divisor))
561                 dn_rehash_zone(dz);
562
563         fp = dn_chain_p(key, dz);
564
565         DN_FIB_SCAN(f, fp) {
566                 if (dn_key_leq(key, f->fn_key))
567                         break;
568         }
569
570         del_fp = NULL;
571
572         if (f && (f->fn_state & DN_S_ZOMBIE) &&
573                         dn_key_eq(f->fn_key, key)) {
574                 del_fp = fp;
575                 fp = &f->fn_next;
576                 f = *fp;
577                 goto create;
578         }
579
580         DN_FIB_SCAN_KEY(f, fp, key) {
581                 if (fi->fib_priority <= DN_FIB_INFO(f)->fib_priority)
582                         break;
583         }
584
585         if (f && dn_key_eq(f->fn_key, key) &&
586                         fi->fib_priority == DN_FIB_INFO(f)->fib_priority) {
587                 struct dn_fib_node **ins_fp;
588
589                 err = -EEXIST;
590                 if (n->nlmsg_flags & NLM_F_EXCL)
591                         goto out;
592
593                 if (n->nlmsg_flags & NLM_F_REPLACE) {
594                         del_fp = fp;
595                         fp = &f->fn_next;
596                         f = *fp;
597                         goto replace;
598                 }
599
600                 ins_fp = fp;
601                 err = -EEXIST;
602
603                 DN_FIB_SCAN_KEY(f, fp, key) {
604                         if (fi->fib_priority != DN_FIB_INFO(f)->fib_priority)
605                                 break;
606                         if (f->fn_type == type &&
607                             f->fn_scope == r->rtm_scope &&
608                             DN_FIB_INFO(f) == fi)
609                                 goto out;
610                 }
611
612                 if (!(n->nlmsg_flags & NLM_F_APPEND)) {
613                         fp = ins_fp;
614                         f = *fp;
615                 }
616         }
617
618 create:
619         err = -ENOENT;
620         if (!(n->nlmsg_flags & NLM_F_CREATE))
621                 goto out;
622
623 replace:
624         err = -ENOBUFS;
625         new_f = kmem_cache_zalloc(dn_hash_kmem, GFP_KERNEL);
626         if (new_f == NULL)
627                 goto out;
628
629         new_f->fn_key = key;
630         new_f->fn_type = type;
631         new_f->fn_scope = r->rtm_scope;
632         DN_FIB_INFO(new_f) = fi;
633
634         new_f->fn_next = f;
635         write_lock_bh(&dn_fib_tables_lock);
636         *fp = new_f;
637         write_unlock_bh(&dn_fib_tables_lock);
638         dz->dz_nent++;
639
640         if (del_fp) {
641                 f = *del_fp;
642                 write_lock_bh(&dn_fib_tables_lock);
643                 *del_fp = f->fn_next;
644                 write_unlock_bh(&dn_fib_tables_lock);
645
646                 if (!(f->fn_state & DN_S_ZOMBIE))
647                         dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
648                 if (f->fn_state & DN_S_ACCESSED)
649                         dn_rt_cache_flush(-1);
650                 dn_free_node(f);
651                 dz->dz_nent--;
652         } else {
653                 dn_rt_cache_flush(-1);
654         }
655
656         dn_rtmsg_fib(RTM_NEWROUTE, new_f, z, tb->n, n, req);
657
658         return 0;
659 out:
660         dn_fib_release_info(fi);
661         return err;
662 }
663
664
665 static int dn_fib_table_delete(struct dn_fib_table *tb, struct rtmsg *r, struct nlattr *attrs[],
666                                struct nlmsghdr *n, struct netlink_skb_parms *req)
667 {
668         struct dn_hash *table = (struct dn_hash*)tb->data;
669         struct dn_fib_node **fp, **del_fp, *f;
670         int z = r->rtm_dst_len;
671         struct dn_zone *dz;
672         dn_fib_key_t key;
673         int matched;
674
675
676         if (z > 16)
677                 return -EINVAL;
678
679         if ((dz = table->dh_zones[z]) == NULL)
680                 return -ESRCH;
681
682         dz_key_0(key);
683         if (attrs[RTA_DST]) {
684                 __le16 dst = nla_get_le16(attrs[RTA_DST]);
685                 if (dst & ~DZ_MASK(dz))
686                         return -EINVAL;
687                 key = dz_key(dst, dz);
688         }
689
690         fp = dn_chain_p(key, dz);
691
692         DN_FIB_SCAN(f, fp) {
693                 if (dn_key_eq(f->fn_key, key))
694                         break;
695                 if (dn_key_leq(key, f->fn_key))
696                         return -ESRCH;
697         }
698
699         matched = 0;
700         del_fp = NULL;
701         DN_FIB_SCAN_KEY(f, fp, key) {
702                 struct dn_fib_info *fi = DN_FIB_INFO(f);
703
704                 if (f->fn_state & DN_S_ZOMBIE)
705                         return -ESRCH;
706
707                 matched++;
708
709                 if (del_fp == NULL &&
710                                 (!r->rtm_type || f->fn_type == r->rtm_type) &&
711                                 (r->rtm_scope == RT_SCOPE_NOWHERE || f->fn_scope == r->rtm_scope) &&
712                                 (!r->rtm_protocol ||
713                                         fi->fib_protocol == r->rtm_protocol) &&
714                                 dn_fib_nh_match(r, n, attrs, fi) == 0)
715                         del_fp = fp;
716         }
717
718         if (del_fp) {
719                 f = *del_fp;
720                 dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
721
722                 if (matched != 1) {
723                         write_lock_bh(&dn_fib_tables_lock);
724                         *del_fp = f->fn_next;
725                         write_unlock_bh(&dn_fib_tables_lock);
726
727                         if (f->fn_state & DN_S_ACCESSED)
728                                 dn_rt_cache_flush(-1);
729                         dn_free_node(f);
730                         dz->dz_nent--;
731                 } else {
732                         f->fn_state |= DN_S_ZOMBIE;
733                         if (f->fn_state & DN_S_ACCESSED) {
734                                 f->fn_state &= ~DN_S_ACCESSED;
735                                 dn_rt_cache_flush(-1);
736                         }
737                         if (++dn_fib_hash_zombies > 128)
738                                 dn_fib_flush();
739                 }
740
741                 return 0;
742         }
743
744         return -ESRCH;
745 }
746
747 static inline int dn_flush_list(struct dn_fib_node **fp, int z, struct dn_hash *table)
748 {
749         int found = 0;
750         struct dn_fib_node *f;
751
752         while((f = *fp) != NULL) {
753                 struct dn_fib_info *fi = DN_FIB_INFO(f);
754
755                 if (fi && ((f->fn_state & DN_S_ZOMBIE) || (fi->fib_flags & RTNH_F_DEAD))) {
756                         write_lock_bh(&dn_fib_tables_lock);
757                         *fp = f->fn_next;
758                         write_unlock_bh(&dn_fib_tables_lock);
759
760                         dn_free_node(f);
761                         found++;
762                         continue;
763                 }
764                 fp = &f->fn_next;
765         }
766
767         return found;
768 }
769
770 static int dn_fib_table_flush(struct dn_fib_table *tb)
771 {
772         struct dn_hash *table = (struct dn_hash *)tb->data;
773         struct dn_zone *dz;
774         int found = 0;
775
776         dn_fib_hash_zombies = 0;
777         for(dz = table->dh_zone_list; dz; dz = dz->dz_next) {
778                 int i;
779                 int tmp = 0;
780                 for(i = dz->dz_divisor-1; i >= 0; i--)
781                         tmp += dn_flush_list(&dz->dz_hash[i], dz->dz_order, table);
782                 dz->dz_nent -= tmp;
783                 found += tmp;
784         }
785
786         return found;
787 }
788
789 static int dn_fib_table_lookup(struct dn_fib_table *tb, const struct flowidn *flp, struct dn_fib_res *res)
790 {
791         int err;
792         struct dn_zone *dz;
793         struct dn_hash *t = (struct dn_hash *)tb->data;
794
795         read_lock(&dn_fib_tables_lock);
796         for(dz = t->dh_zone_list; dz; dz = dz->dz_next) {
797                 struct dn_fib_node *f;
798                 dn_fib_key_t k = dz_key(flp->daddr, dz);
799
800                 for(f = dz_chain(k, dz); f; f = f->fn_next) {
801                         if (!dn_key_eq(k, f->fn_key)) {
802                                 if (dn_key_leq(k, f->fn_key))
803                                         break;
804                                 else
805                                         continue;
806                         }
807
808                         f->fn_state |= DN_S_ACCESSED;
809
810                         if (f->fn_state&DN_S_ZOMBIE)
811                                 continue;
812
813                         if (f->fn_scope < flp->flowidn_scope)
814                                 continue;
815
816                         err = dn_fib_semantic_match(f->fn_type, DN_FIB_INFO(f), flp, res);
817
818                         if (err == 0) {
819                                 res->type = f->fn_type;
820                                 res->scope = f->fn_scope;
821                                 res->prefixlen = dz->dz_order;
822                                 goto out;
823                         }
824                         if (err < 0)
825                                 goto out;
826                 }
827         }
828         err = 1;
829 out:
830         read_unlock(&dn_fib_tables_lock);
831         return err;
832 }
833
834
835 struct dn_fib_table *dn_fib_get_table(u32 n, int create)
836 {
837         struct dn_fib_table *t;
838         unsigned int h;
839
840         if (n < RT_TABLE_MIN)
841                 return NULL;
842
843         if (n > RT_TABLE_MAX)
844                 return NULL;
845
846         h = n & (DN_FIB_TABLE_HASHSZ - 1);
847         rcu_read_lock();
848         hlist_for_each_entry_rcu(t, &dn_fib_table_hash[h], hlist) {
849                 if (t->n == n) {
850                         rcu_read_unlock();
851                         return t;
852                 }
853         }
854         rcu_read_unlock();
855
856         if (!create)
857                 return NULL;
858
859         if (in_interrupt()) {
860                 net_dbg_ratelimited("DECnet: BUG! Attempt to create routing table from interrupt\n");
861                 return NULL;
862         }
863
864         t = kzalloc(sizeof(struct dn_fib_table) + sizeof(struct dn_hash),
865                     GFP_KERNEL);
866         if (t == NULL)
867                 return NULL;
868
869         t->n = n;
870         t->insert = dn_fib_table_insert;
871         t->delete = dn_fib_table_delete;
872         t->lookup = dn_fib_table_lookup;
873         t->flush  = dn_fib_table_flush;
874         t->dump = dn_fib_table_dump;
875         hlist_add_head_rcu(&t->hlist, &dn_fib_table_hash[h]);
876
877         return t;
878 }
879
880 struct dn_fib_table *dn_fib_empty_table(void)
881 {
882         u32 id;
883
884         for(id = RT_TABLE_MIN; id <= RT_TABLE_MAX; id++)
885                 if (dn_fib_get_table(id, 0) == NULL)
886                         return dn_fib_get_table(id, 1);
887         return NULL;
888 }
889
890 void dn_fib_flush(void)
891 {
892         int flushed = 0;
893         struct dn_fib_table *tb;
894         unsigned int h;
895
896         for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
897                 hlist_for_each_entry(tb, &dn_fib_table_hash[h], hlist)
898                         flushed += tb->flush(tb);
899         }
900
901         if (flushed)
902                 dn_rt_cache_flush(-1);
903 }
904
905 void __init dn_fib_table_init(void)
906 {
907         dn_hash_kmem = kmem_cache_create("dn_fib_info_cache",
908                                         sizeof(struct dn_fib_info),
909                                         0, SLAB_HWCACHE_ALIGN,
910                                         NULL);
911 }
912
913 void __exit dn_fib_table_cleanup(void)
914 {
915         struct dn_fib_table *t;
916         struct hlist_node *next;
917         unsigned int h;
918
919         write_lock(&dn_fib_tables_lock);
920         for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
921                 hlist_for_each_entry_safe(t, next, &dn_fib_table_hash[h],
922                                           hlist) {
923                         hlist_del(&t->hlist);
924                         kfree(t);
925                 }
926         }
927         write_unlock(&dn_fib_tables_lock);
928 }