[NET] NETNS: Omit sock->sk_net without CONFIG_NET_NS.
[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/netlink.h>
32 #include <net/dst.h>
33 #include <net/flow.h>
34 #include <net/fib_rules.h>
35 #include <net/dn.h>
36 #include <net/dn_route.h>
37 #include <net/dn_fib.h>
38 #include <net/dn_neigh.h>
39 #include <net/dn_dev.h>
40
41 struct dn_zone
42 {
43         struct dn_zone          *dz_next;
44         struct dn_fib_node      **dz_hash;
45         int                     dz_nent;
46         int                     dz_divisor;
47         u32                     dz_hashmask;
48 #define DZ_HASHMASK(dz) ((dz)->dz_hashmask)
49         int                     dz_order;
50         __le16                  dz_mask;
51 #define DZ_MASK(dz)     ((dz)->dz_mask)
52 };
53
54 struct dn_hash
55 {
56         struct dn_zone  *dh_zones[17];
57         struct dn_zone  *dh_zone_list;
58 };
59
60 #define dz_key_0(key)           ((key).datum = 0)
61 #define dz_prefix(key,dz)       ((key).datum)
62
63 #define for_nexthops(fi) { int nhsel; const struct dn_fib_nh *nh;\
64         for(nhsel = 0, nh = (fi)->fib_nh; nhsel < (fi)->fib_nhs; nh++, nhsel++)
65
66 #define endfor_nexthops(fi) }
67
68 #define DN_MAX_DIVISOR 1024
69 #define DN_S_ZOMBIE 1
70 #define DN_S_ACCESSED 2
71
72 #define DN_FIB_SCAN(f, fp) \
73 for( ; ((f) = *(fp)) != NULL; (fp) = &(f)->fn_next)
74
75 #define DN_FIB_SCAN_KEY(f, fp, key) \
76 for( ; ((f) = *(fp)) != NULL && dn_key_eq((f)->fn_key, (key)); (fp) = &(f)->fn_next)
77
78 #define RT_TABLE_MIN 1
79 #define DN_FIB_TABLE_HASHSZ 256
80 static struct hlist_head dn_fib_table_hash[DN_FIB_TABLE_HASHSZ];
81 static DEFINE_RWLOCK(dn_fib_tables_lock);
82
83 static struct kmem_cache *dn_hash_kmem __read_mostly;
84 static int dn_fib_hash_zombies;
85
86 static inline dn_fib_idx_t dn_hash(dn_fib_key_t key, struct dn_zone *dz)
87 {
88         u16 h = dn_ntohs(key.datum)>>(16 - dz->dz_order);
89         h ^= (h >> 10);
90         h ^= (h >> 6);
91         h &= DZ_HASHMASK(dz);
92         return *(dn_fib_idx_t *)&h;
93 }
94
95 static inline dn_fib_key_t dz_key(__le16 dst, struct dn_zone *dz)
96 {
97         dn_fib_key_t k;
98         k.datum = dst & DZ_MASK(dz);
99         return k;
100 }
101
102 static inline struct dn_fib_node **dn_chain_p(dn_fib_key_t key, struct dn_zone *dz)
103 {
104         return &dz->dz_hash[dn_hash(key, dz).datum];
105 }
106
107 static inline struct dn_fib_node *dz_chain(dn_fib_key_t key, struct dn_zone *dz)
108 {
109         return dz->dz_hash[dn_hash(key, dz).datum];
110 }
111
112 static inline int dn_key_eq(dn_fib_key_t a, dn_fib_key_t b)
113 {
114         return a.datum == b.datum;
115 }
116
117 static inline int dn_key_leq(dn_fib_key_t a, dn_fib_key_t b)
118 {
119         return a.datum <= b.datum;
120 }
121
122 static inline void dn_rebuild_zone(struct dn_zone *dz,
123                                    struct dn_fib_node **old_ht,
124                                    int old_divisor)
125 {
126         int i;
127         struct dn_fib_node *f, **fp, *next;
128
129         for(i = 0; i < old_divisor; i++) {
130                 for(f = old_ht[i]; f; f = f->fn_next) {
131                         next = f->fn_next;
132                         for(fp = dn_chain_p(f->fn_key, dz);
133                                 *fp && dn_key_leq((*fp)->fn_key, f->fn_key);
134                                 fp = &(*fp)->fn_next)
135                                 /* NOTHING */;
136                         f->fn_next = *fp;
137                         *fp = f;
138                 }
139         }
140 }
141
142 static void dn_rehash_zone(struct dn_zone *dz)
143 {
144         struct dn_fib_node **ht, **old_ht;
145         int old_divisor, new_divisor;
146         u32 new_hashmask;
147
148         old_divisor = dz->dz_divisor;
149
150         switch(old_divisor) {
151                 case 16:
152                         new_divisor = 256;
153                         new_hashmask = 0xFF;
154                         break;
155                 default:
156                         printk(KERN_DEBUG "DECnet: dn_rehash_zone: BUG! %d\n", old_divisor);
157                 case 256:
158                         new_divisor = 1024;
159                         new_hashmask = 0x3FF;
160                         break;
161         }
162
163         ht = kcalloc(new_divisor, sizeof(struct dn_fib_node*), GFP_KERNEL);
164         if (ht == NULL)
165                 return;
166
167         write_lock_bh(&dn_fib_tables_lock);
168         old_ht = dz->dz_hash;
169         dz->dz_hash = ht;
170         dz->dz_hashmask = new_hashmask;
171         dz->dz_divisor = new_divisor;
172         dn_rebuild_zone(dz, old_ht, old_divisor);
173         write_unlock_bh(&dn_fib_tables_lock);
174         kfree(old_ht);
175 }
176
177 static void dn_free_node(struct dn_fib_node *f)
178 {
179         dn_fib_release_info(DN_FIB_INFO(f));
180         kmem_cache_free(dn_hash_kmem, f);
181 }
182
183
184 static struct dn_zone *dn_new_zone(struct dn_hash *table, int z)
185 {
186         int i;
187         struct dn_zone *dz = kzalloc(sizeof(struct dn_zone), GFP_KERNEL);
188         if (!dz)
189                 return NULL;
190
191         if (z) {
192                 dz->dz_divisor = 16;
193                 dz->dz_hashmask = 0x0F;
194         } else {
195                 dz->dz_divisor = 1;
196                 dz->dz_hashmask = 0;
197         }
198
199         dz->dz_hash = kcalloc(dz->dz_divisor, sizeof(struct dn_fib_node *), GFP_KERNEL);
200         if (!dz->dz_hash) {
201                 kfree(dz);
202                 return NULL;
203         }
204
205         dz->dz_order = z;
206         dz->dz_mask = dnet_make_mask(z);
207
208         for(i = z + 1; i <= 16; i++)
209                 if (table->dh_zones[i])
210                         break;
211
212         write_lock_bh(&dn_fib_tables_lock);
213         if (i>16) {
214                 dz->dz_next = table->dh_zone_list;
215                 table->dh_zone_list = dz;
216         } else {
217                 dz->dz_next = table->dh_zones[i]->dz_next;
218                 table->dh_zones[i]->dz_next = dz;
219         }
220         table->dh_zones[z] = dz;
221         write_unlock_bh(&dn_fib_tables_lock);
222         return dz;
223 }
224
225
226 static int dn_fib_nh_match(struct rtmsg *r, struct nlmsghdr *nlh, struct dn_kern_rta *rta, struct dn_fib_info *fi)
227 {
228         struct rtnexthop *nhp;
229         int nhlen;
230
231         if (rta->rta_priority && *rta->rta_priority != fi->fib_priority)
232                 return 1;
233
234         if (rta->rta_oif || rta->rta_gw) {
235                 if ((!rta->rta_oif || *rta->rta_oif == fi->fib_nh->nh_oif) &&
236                     (!rta->rta_gw  || memcmp(rta->rta_gw, &fi->fib_nh->nh_gw, 2) == 0))
237                         return 0;
238                 return 1;
239         }
240
241         if (rta->rta_mp == NULL)
242                 return 0;
243
244         nhp = RTA_DATA(rta->rta_mp);
245         nhlen = RTA_PAYLOAD(rta->rta_mp);
246
247         for_nexthops(fi) {
248                 int attrlen = nhlen - sizeof(struct rtnexthop);
249                 __le16 gw;
250
251                 if (attrlen < 0 || (nhlen -= nhp->rtnh_len) < 0)
252                         return -EINVAL;
253                 if (nhp->rtnh_ifindex && nhp->rtnh_ifindex != nh->nh_oif)
254                         return 1;
255                 if (attrlen) {
256                         gw = dn_fib_get_attr16(RTNH_DATA(nhp), attrlen, RTA_GATEWAY);
257
258                         if (gw && gw != nh->nh_gw)
259                                 return 1;
260                 }
261                 nhp = RTNH_NEXT(nhp);
262         } endfor_nexthops(fi);
263
264         return 0;
265 }
266
267 static inline size_t dn_fib_nlmsg_size(struct dn_fib_info *fi)
268 {
269         size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg))
270                          + nla_total_size(4) /* RTA_TABLE */
271                          + nla_total_size(2) /* RTA_DST */
272                          + nla_total_size(4); /* RTA_PRIORITY */
273
274         /* space for nested metrics */
275         payload += nla_total_size((RTAX_MAX * nla_total_size(4)));
276
277         if (fi->fib_nhs) {
278                 /* Also handles the special case fib_nhs == 1 */
279
280                 /* each nexthop is packed in an attribute */
281                 size_t nhsize = nla_total_size(sizeof(struct rtnexthop));
282
283                 /* may contain a gateway attribute */
284                 nhsize += nla_total_size(4);
285
286                 /* all nexthops are packed in a nested attribute */
287                 payload += nla_total_size(fi->fib_nhs * nhsize);
288         }
289
290         return payload;
291 }
292
293 static int dn_fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
294                         u32 tb_id, u8 type, u8 scope, void *dst, int dst_len,
295                         struct dn_fib_info *fi, unsigned int flags)
296 {
297         struct rtmsg *rtm;
298         struct nlmsghdr *nlh;
299         unsigned char *b = skb_tail_pointer(skb);
300
301         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*rtm), flags);
302         rtm = NLMSG_DATA(nlh);
303         rtm->rtm_family = AF_DECnet;
304         rtm->rtm_dst_len = dst_len;
305         rtm->rtm_src_len = 0;
306         rtm->rtm_tos = 0;
307         rtm->rtm_table = tb_id;
308         RTA_PUT_U32(skb, RTA_TABLE, tb_id);
309         rtm->rtm_flags = fi->fib_flags;
310         rtm->rtm_scope = scope;
311         rtm->rtm_type  = type;
312         if (rtm->rtm_dst_len)
313                 RTA_PUT(skb, RTA_DST, 2, dst);
314         rtm->rtm_protocol = fi->fib_protocol;
315         if (fi->fib_priority)
316                 RTA_PUT(skb, RTA_PRIORITY, 4, &fi->fib_priority);
317         if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0)
318                 goto rtattr_failure;
319         if (fi->fib_nhs == 1) {
320                 if (fi->fib_nh->nh_gw)
321                         RTA_PUT(skb, RTA_GATEWAY, 2, &fi->fib_nh->nh_gw);
322                 if (fi->fib_nh->nh_oif)
323                         RTA_PUT(skb, RTA_OIF, sizeof(int), &fi->fib_nh->nh_oif);
324         }
325         if (fi->fib_nhs > 1) {
326                 struct rtnexthop *nhp;
327                 struct rtattr *mp_head;
328                 if (skb_tailroom(skb) <= RTA_SPACE(0))
329                         goto rtattr_failure;
330                 mp_head = (struct rtattr *)skb_put(skb, RTA_SPACE(0));
331
332                 for_nexthops(fi) {
333                         if (skb_tailroom(skb) < RTA_ALIGN(RTA_ALIGN(sizeof(*nhp)) + 4))
334                                 goto rtattr_failure;
335                         nhp = (struct rtnexthop *)skb_put(skb, RTA_ALIGN(sizeof(*nhp)));
336                         nhp->rtnh_flags = nh->nh_flags & 0xFF;
337                         nhp->rtnh_hops = nh->nh_weight - 1;
338                         nhp->rtnh_ifindex = nh->nh_oif;
339                         if (nh->nh_gw)
340                                 RTA_PUT(skb, RTA_GATEWAY, 2, &nh->nh_gw);
341                         nhp->rtnh_len = skb_tail_pointer(skb) - (unsigned char *)nhp;
342                 } endfor_nexthops(fi);
343                 mp_head->rta_type = RTA_MULTIPATH;
344                 mp_head->rta_len = skb_tail_pointer(skb) - (u8 *)mp_head;
345         }
346
347         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
348         return skb->len;
349
350
351 nlmsg_failure:
352 rtattr_failure:
353         nlmsg_trim(skb, b);
354         return -EMSGSIZE;
355 }
356
357
358 static void dn_rtmsg_fib(int event, struct dn_fib_node *f, int z, u32 tb_id,
359                         struct nlmsghdr *nlh, struct netlink_skb_parms *req)
360 {
361         struct sk_buff *skb;
362         u32 pid = req ? req->pid : 0;
363         int err = -ENOBUFS;
364
365         skb = nlmsg_new(dn_fib_nlmsg_size(DN_FIB_INFO(f)), GFP_KERNEL);
366         if (skb == NULL)
367                 goto errout;
368
369         err = dn_fib_dump_info(skb, pid, nlh->nlmsg_seq, event, tb_id,
370                                f->fn_type, f->fn_scope, &f->fn_key, z,
371                                DN_FIB_INFO(f), 0);
372         if (err < 0) {
373                 /* -EMSGSIZE implies BUG in dn_fib_nlmsg_size() */
374                 WARN_ON(err == -EMSGSIZE);
375                 kfree_skb(skb);
376                 goto errout;
377         }
378         err = rtnl_notify(skb, &init_net, pid, RTNLGRP_DECnet_ROUTE, nlh, GFP_KERNEL);
379 errout:
380         if (err < 0)
381                 rtnl_set_sk_err(&init_net, RTNLGRP_DECnet_ROUTE, err);
382 }
383
384 static __inline__ int dn_hash_dump_bucket(struct sk_buff *skb,
385                                 struct netlink_callback *cb,
386                                 struct dn_fib_table *tb,
387                                 struct dn_zone *dz,
388                                 struct dn_fib_node *f)
389 {
390         int i, s_i;
391
392         s_i = cb->args[4];
393         for(i = 0; f; i++, f = f->fn_next) {
394                 if (i < s_i)
395                         continue;
396                 if (f->fn_state & DN_S_ZOMBIE)
397                         continue;
398                 if (dn_fib_dump_info(skb, NETLINK_CB(cb->skb).pid,
399                                 cb->nlh->nlmsg_seq,
400                                 RTM_NEWROUTE,
401                                 tb->n,
402                                 (f->fn_state & DN_S_ZOMBIE) ? 0 : f->fn_type,
403                                 f->fn_scope, &f->fn_key, dz->dz_order,
404                                 f->fn_info, NLM_F_MULTI) < 0) {
405                         cb->args[4] = i;
406                         return -1;
407                 }
408         }
409         cb->args[4] = i;
410         return skb->len;
411 }
412
413 static __inline__ int dn_hash_dump_zone(struct sk_buff *skb,
414                                 struct netlink_callback *cb,
415                                 struct dn_fib_table *tb,
416                                 struct dn_zone *dz)
417 {
418         int h, s_h;
419
420         s_h = cb->args[3];
421         for(h = 0; h < dz->dz_divisor; h++) {
422                 if (h < s_h)
423                         continue;
424                 if (h > s_h)
425                         memset(&cb->args[4], 0, sizeof(cb->args) - 4*sizeof(cb->args[0]));
426                 if (dz->dz_hash == NULL || dz->dz_hash[h] == NULL)
427                         continue;
428                 if (dn_hash_dump_bucket(skb, cb, tb, dz, dz->dz_hash[h]) < 0) {
429                         cb->args[3] = h;
430                         return -1;
431                 }
432         }
433         cb->args[3] = h;
434         return skb->len;
435 }
436
437 static int dn_fib_table_dump(struct dn_fib_table *tb, struct sk_buff *skb,
438                                 struct netlink_callback *cb)
439 {
440         int m, s_m;
441         struct dn_zone *dz;
442         struct dn_hash *table = (struct dn_hash *)tb->data;
443
444         s_m = cb->args[2];
445         read_lock(&dn_fib_tables_lock);
446         for(dz = table->dh_zone_list, m = 0; dz; dz = dz->dz_next, m++) {
447                 if (m < s_m)
448                         continue;
449                 if (m > s_m)
450                         memset(&cb->args[3], 0, sizeof(cb->args) - 3*sizeof(cb->args[0]));
451
452                 if (dn_hash_dump_zone(skb, cb, tb, dz) < 0) {
453                         cb->args[2] = m;
454                         read_unlock(&dn_fib_tables_lock);
455                         return -1;
456                 }
457         }
458         read_unlock(&dn_fib_tables_lock);
459         cb->args[2] = m;
460
461         return skb->len;
462 }
463
464 int dn_fib_dump(struct sk_buff *skb, struct netlink_callback *cb)
465 {
466         struct net *net = sock_net(skb->sk);
467         unsigned int h, s_h;
468         unsigned int e = 0, s_e;
469         struct dn_fib_table *tb;
470         struct hlist_node *node;
471         int dumped = 0;
472
473         if (net != &init_net)
474                 return 0;
475
476         if (NLMSG_PAYLOAD(cb->nlh, 0) >= sizeof(struct rtmsg) &&
477                 ((struct rtmsg *)NLMSG_DATA(cb->nlh))->rtm_flags&RTM_F_CLONED)
478                         return dn_cache_dump(skb, cb);
479
480         s_h = cb->args[0];
481         s_e = cb->args[1];
482
483         for (h = s_h; h < DN_FIB_TABLE_HASHSZ; h++, s_h = 0) {
484                 e = 0;
485                 hlist_for_each_entry(tb, node, &dn_fib_table_hash[h], hlist) {
486                         if (e < s_e)
487                                 goto next;
488                         if (dumped)
489                                 memset(&cb->args[2], 0, sizeof(cb->args) -
490                                                  2 * sizeof(cb->args[0]));
491                         if (tb->dump(tb, skb, cb) < 0)
492                                 goto out;
493                         dumped = 1;
494 next:
495                         e++;
496                 }
497         }
498 out:
499         cb->args[1] = e;
500         cb->args[0] = h;
501
502         return skb->len;
503 }
504
505 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)
506 {
507         struct dn_hash *table = (struct dn_hash *)tb->data;
508         struct dn_fib_node *new_f, *f, **fp, **del_fp;
509         struct dn_zone *dz;
510         struct dn_fib_info *fi;
511         int z = r->rtm_dst_len;
512         int type = r->rtm_type;
513         dn_fib_key_t key;
514         int err;
515
516         if (z > 16)
517                 return -EINVAL;
518
519         dz = table->dh_zones[z];
520         if (!dz && !(dz = dn_new_zone(table, z)))
521                 return -ENOBUFS;
522
523         dz_key_0(key);
524         if (rta->rta_dst) {
525                 __le16 dst;
526                 memcpy(&dst, rta->rta_dst, 2);
527                 if (dst & ~DZ_MASK(dz))
528                         return -EINVAL;
529                 key = dz_key(dst, dz);
530         }
531
532         if ((fi = dn_fib_create_info(r, rta, n, &err)) == NULL)
533                 return err;
534
535         if (dz->dz_nent > (dz->dz_divisor << 2) &&
536                         dz->dz_divisor > DN_MAX_DIVISOR &&
537                         (z==16 || (1<<z) > dz->dz_divisor))
538                 dn_rehash_zone(dz);
539
540         fp = dn_chain_p(key, dz);
541
542         DN_FIB_SCAN(f, fp) {
543                 if (dn_key_leq(key, f->fn_key))
544                         break;
545         }
546
547         del_fp = NULL;
548
549         if (f && (f->fn_state & DN_S_ZOMBIE) &&
550                         dn_key_eq(f->fn_key, key)) {
551                 del_fp = fp;
552                 fp = &f->fn_next;
553                 f = *fp;
554                 goto create;
555         }
556
557         DN_FIB_SCAN_KEY(f, fp, key) {
558                 if (fi->fib_priority <= DN_FIB_INFO(f)->fib_priority)
559                         break;
560         }
561
562         if (f && dn_key_eq(f->fn_key, key) &&
563                         fi->fib_priority == DN_FIB_INFO(f)->fib_priority) {
564                 struct dn_fib_node **ins_fp;
565
566                 err = -EEXIST;
567                 if (n->nlmsg_flags & NLM_F_EXCL)
568                         goto out;
569
570                 if (n->nlmsg_flags & NLM_F_REPLACE) {
571                         del_fp = fp;
572                         fp = &f->fn_next;
573                         f = *fp;
574                         goto replace;
575                 }
576
577                 ins_fp = fp;
578                 err = -EEXIST;
579
580                 DN_FIB_SCAN_KEY(f, fp, key) {
581                         if (fi->fib_priority != DN_FIB_INFO(f)->fib_priority)
582                                 break;
583                         if (f->fn_type == type && f->fn_scope == r->rtm_scope
584                                         && DN_FIB_INFO(f) == fi)
585                                 goto out;
586                 }
587
588                 if (!(n->nlmsg_flags & NLM_F_APPEND)) {
589                         fp = ins_fp;
590                         f = *fp;
591                 }
592         }
593
594 create:
595         err = -ENOENT;
596         if (!(n->nlmsg_flags & NLM_F_CREATE))
597                 goto out;
598
599 replace:
600         err = -ENOBUFS;
601         new_f = kmem_cache_zalloc(dn_hash_kmem, GFP_KERNEL);
602         if (new_f == NULL)
603                 goto out;
604
605         new_f->fn_key = key;
606         new_f->fn_type = type;
607         new_f->fn_scope = r->rtm_scope;
608         DN_FIB_INFO(new_f) = fi;
609
610         new_f->fn_next = f;
611         write_lock_bh(&dn_fib_tables_lock);
612         *fp = new_f;
613         write_unlock_bh(&dn_fib_tables_lock);
614         dz->dz_nent++;
615
616         if (del_fp) {
617                 f = *del_fp;
618                 write_lock_bh(&dn_fib_tables_lock);
619                 *del_fp = f->fn_next;
620                 write_unlock_bh(&dn_fib_tables_lock);
621
622                 if (!(f->fn_state & DN_S_ZOMBIE))
623                         dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
624                 if (f->fn_state & DN_S_ACCESSED)
625                         dn_rt_cache_flush(-1);
626                 dn_free_node(f);
627                 dz->dz_nent--;
628         } else {
629                 dn_rt_cache_flush(-1);
630         }
631
632         dn_rtmsg_fib(RTM_NEWROUTE, new_f, z, tb->n, n, req);
633
634         return 0;
635 out:
636         dn_fib_release_info(fi);
637         return err;
638 }
639
640
641 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)
642 {
643         struct dn_hash *table = (struct dn_hash*)tb->data;
644         struct dn_fib_node **fp, **del_fp, *f;
645         int z = r->rtm_dst_len;
646         struct dn_zone *dz;
647         dn_fib_key_t key;
648         int matched;
649
650
651         if (z > 16)
652                 return -EINVAL;
653
654         if ((dz = table->dh_zones[z]) == NULL)
655                 return -ESRCH;
656
657         dz_key_0(key);
658         if (rta->rta_dst) {
659                 __le16 dst;
660                 memcpy(&dst, rta->rta_dst, 2);
661                 if (dst & ~DZ_MASK(dz))
662                         return -EINVAL;
663                 key = dz_key(dst, dz);
664         }
665
666         fp = dn_chain_p(key, dz);
667
668         DN_FIB_SCAN(f, fp) {
669                 if (dn_key_eq(f->fn_key, key))
670                         break;
671                 if (dn_key_leq(key, f->fn_key))
672                         return -ESRCH;
673         }
674
675         matched = 0;
676         del_fp = NULL;
677         DN_FIB_SCAN_KEY(f, fp, key) {
678                 struct dn_fib_info *fi = DN_FIB_INFO(f);
679
680                 if (f->fn_state & DN_S_ZOMBIE)
681                         return -ESRCH;
682
683                 matched++;
684
685                 if (del_fp == NULL &&
686                                 (!r->rtm_type || f->fn_type == r->rtm_type) &&
687                                 (r->rtm_scope == RT_SCOPE_NOWHERE || f->fn_scope == r->rtm_scope) &&
688                                 (!r->rtm_protocol ||
689                                         fi->fib_protocol == r->rtm_protocol) &&
690                                 dn_fib_nh_match(r, n, rta, fi) == 0)
691                         del_fp = fp;
692         }
693
694         if (del_fp) {
695                 f = *del_fp;
696                 dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
697
698                 if (matched != 1) {
699                         write_lock_bh(&dn_fib_tables_lock);
700                         *del_fp = f->fn_next;
701                         write_unlock_bh(&dn_fib_tables_lock);
702
703                         if (f->fn_state & DN_S_ACCESSED)
704                                 dn_rt_cache_flush(-1);
705                         dn_free_node(f);
706                         dz->dz_nent--;
707                 } else {
708                         f->fn_state |= DN_S_ZOMBIE;
709                         if (f->fn_state & DN_S_ACCESSED) {
710                                 f->fn_state &= ~DN_S_ACCESSED;
711                                 dn_rt_cache_flush(-1);
712                         }
713                         if (++dn_fib_hash_zombies > 128)
714                                 dn_fib_flush();
715                 }
716
717                 return 0;
718         }
719
720         return -ESRCH;
721 }
722
723 static inline int dn_flush_list(struct dn_fib_node **fp, int z, struct dn_hash *table)
724 {
725         int found = 0;
726         struct dn_fib_node *f;
727
728         while((f = *fp) != NULL) {
729                 struct dn_fib_info *fi = DN_FIB_INFO(f);
730
731                 if (fi && ((f->fn_state & DN_S_ZOMBIE) || (fi->fib_flags & RTNH_F_DEAD))) {
732                         write_lock_bh(&dn_fib_tables_lock);
733                         *fp = f->fn_next;
734                         write_unlock_bh(&dn_fib_tables_lock);
735
736                         dn_free_node(f);
737                         found++;
738                         continue;
739                 }
740                 fp = &f->fn_next;
741         }
742
743         return found;
744 }
745
746 static int dn_fib_table_flush(struct dn_fib_table *tb)
747 {
748         struct dn_hash *table = (struct dn_hash *)tb->data;
749         struct dn_zone *dz;
750         int found = 0;
751
752         dn_fib_hash_zombies = 0;
753         for(dz = table->dh_zone_list; dz; dz = dz->dz_next) {
754                 int i;
755                 int tmp = 0;
756                 for(i = dz->dz_divisor-1; i >= 0; i--)
757                         tmp += dn_flush_list(&dz->dz_hash[i], dz->dz_order, table);
758                 dz->dz_nent -= tmp;
759                 found += tmp;
760         }
761
762         return found;
763 }
764
765 static int dn_fib_table_lookup(struct dn_fib_table *tb, const struct flowi *flp, struct dn_fib_res *res)
766 {
767         int err;
768         struct dn_zone *dz;
769         struct dn_hash *t = (struct dn_hash *)tb->data;
770
771         read_lock(&dn_fib_tables_lock);
772         for(dz = t->dh_zone_list; dz; dz = dz->dz_next) {
773                 struct dn_fib_node *f;
774                 dn_fib_key_t k = dz_key(flp->fld_dst, dz);
775
776                 for(f = dz_chain(k, dz); f; f = f->fn_next) {
777                         if (!dn_key_eq(k, f->fn_key)) {
778                                 if (dn_key_leq(k, f->fn_key))
779                                         break;
780                                 else
781                                         continue;
782                         }
783
784                         f->fn_state |= DN_S_ACCESSED;
785
786                         if (f->fn_state&DN_S_ZOMBIE)
787                                 continue;
788
789                         if (f->fn_scope < flp->fld_scope)
790                                 continue;
791
792                         err = dn_fib_semantic_match(f->fn_type, DN_FIB_INFO(f), flp, res);
793
794                         if (err == 0) {
795                                 res->type = f->fn_type;
796                                 res->scope = f->fn_scope;
797                                 res->prefixlen = dz->dz_order;
798                                 goto out;
799                         }
800                         if (err < 0)
801                                 goto out;
802                 }
803         }
804         err = 1;
805 out:
806         read_unlock(&dn_fib_tables_lock);
807         return err;
808 }
809
810
811 struct dn_fib_table *dn_fib_get_table(u32 n, int create)
812 {
813         struct dn_fib_table *t;
814         struct hlist_node *node;
815         unsigned int h;
816
817         if (n < RT_TABLE_MIN)
818                 return NULL;
819
820         if (n > RT_TABLE_MAX)
821                 return NULL;
822
823         h = n & (DN_FIB_TABLE_HASHSZ - 1);
824         rcu_read_lock();
825         hlist_for_each_entry_rcu(t, node, &dn_fib_table_hash[h], hlist) {
826                 if (t->n == n) {
827                         rcu_read_unlock();
828                         return t;
829                 }
830         }
831         rcu_read_unlock();
832
833         if (!create)
834                 return NULL;
835
836         if (in_interrupt() && net_ratelimit()) {
837                 printk(KERN_DEBUG "DECnet: BUG! Attempt to create routing table from interrupt\n");
838                 return NULL;
839         }
840
841         t = kzalloc(sizeof(struct dn_fib_table) + sizeof(struct dn_hash),
842                     GFP_KERNEL);
843         if (t == NULL)
844                 return NULL;
845
846         t->n = n;
847         t->insert = dn_fib_table_insert;
848         t->delete = dn_fib_table_delete;
849         t->lookup = dn_fib_table_lookup;
850         t->flush  = dn_fib_table_flush;
851         t->dump = dn_fib_table_dump;
852         hlist_add_head_rcu(&t->hlist, &dn_fib_table_hash[h]);
853
854         return t;
855 }
856
857 struct dn_fib_table *dn_fib_empty_table(void)
858 {
859         u32 id;
860
861         for(id = RT_TABLE_MIN; id <= RT_TABLE_MAX; id++)
862                 if (dn_fib_get_table(id, 0) == NULL)
863                         return dn_fib_get_table(id, 1);
864         return NULL;
865 }
866
867 void dn_fib_flush(void)
868 {
869         int flushed = 0;
870         struct dn_fib_table *tb;
871         struct hlist_node *node;
872         unsigned int h;
873
874         for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
875                 hlist_for_each_entry(tb, node, &dn_fib_table_hash[h], hlist)
876                         flushed += tb->flush(tb);
877         }
878
879         if (flushed)
880                 dn_rt_cache_flush(-1);
881 }
882
883 void __init dn_fib_table_init(void)
884 {
885         dn_hash_kmem = kmem_cache_create("dn_fib_info_cache",
886                                         sizeof(struct dn_fib_info),
887                                         0, SLAB_HWCACHE_ALIGN,
888                                         NULL);
889 }
890
891 void __exit dn_fib_table_cleanup(void)
892 {
893         struct dn_fib_table *t;
894         struct hlist_node *node, *next;
895         unsigned int h;
896
897         write_lock(&dn_fib_tables_lock);
898         for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
899                 hlist_for_each_entry_safe(t, node, next, &dn_fib_table_hash[h],
900                                           hlist) {
901                         hlist_del(&t->hlist);
902                         kfree(t);
903                 }
904         }
905         write_unlock(&dn_fib_tables_lock);
906 }