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TOMOYO Linux Cross Reference
Linux/net/decnet/dn_table.c

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  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                 fallthrough;
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                 mp_head = nla_nest_start_noflag(skb, RTA_MULTIPATH);
352                 if (!mp_head)
353                         goto errout;
354 
355                 for_nexthops(fi) {
356                         if (!(nhp = nla_reserve_nohdr(skb, sizeof(*nhp))))
357                                 goto errout;
358 
359                         nhp->rtnh_flags = nh->nh_flags & 0xFF;
360                         nhp->rtnh_hops = nh->nh_weight - 1;
361                         nhp->rtnh_ifindex = nh->nh_oif;
362 
363                         if (nh->nh_gw &&
364                             nla_put_le16(skb, RTA_GATEWAY, nh->nh_gw) < 0)
365                                 goto errout;
366 
367                         nhp->rtnh_len = skb_tail_pointer(skb) - (unsigned char *)nhp;
368                 } endfor_nexthops(fi);
369 
370                 nla_nest_end(skb, mp_head);
371         }
372 
373         nlmsg_end(skb, nlh);
374         return 0;
375 
376 errout:
377         nlmsg_cancel(skb, nlh);
378         return -EMSGSIZE;
379 }
380 
381 
382 static void dn_rtmsg_fib(int event, struct dn_fib_node *f, int z, u32 tb_id,
383                         struct nlmsghdr *nlh, struct netlink_skb_parms *req)
384 {
385         struct sk_buff *skb;
386         u32 portid = req ? req->portid : 0;
387         int err = -ENOBUFS;
388 
389         skb = nlmsg_new(dn_fib_nlmsg_size(DN_FIB_INFO(f)), GFP_KERNEL);
390         if (skb == NULL)
391                 goto errout;
392 
393         err = dn_fib_dump_info(skb, portid, nlh->nlmsg_seq, event, tb_id,
394                                f->fn_type, f->fn_scope, &f->fn_key, z,
395                                DN_FIB_INFO(f), 0);
396         if (err < 0) {
397                 /* -EMSGSIZE implies BUG in dn_fib_nlmsg_size() */
398                 WARN_ON(err == -EMSGSIZE);
399                 kfree_skb(skb);
400                 goto errout;
401         }
402         rtnl_notify(skb, &init_net, portid, RTNLGRP_DECnet_ROUTE, nlh, GFP_KERNEL);
403         return;
404 errout:
405         if (err < 0)
406                 rtnl_set_sk_err(&init_net, RTNLGRP_DECnet_ROUTE, err);
407 }
408 
409 static __inline__ int dn_hash_dump_bucket(struct sk_buff *skb,
410                                 struct netlink_callback *cb,
411                                 struct dn_fib_table *tb,
412                                 struct dn_zone *dz,
413                                 struct dn_fib_node *f)
414 {
415         int i, s_i;
416 
417         s_i = cb->args[4];
418         for(i = 0; f; i++, f = f->fn_next) {
419                 if (i < s_i)
420                         continue;
421                 if (f->fn_state & DN_S_ZOMBIE)
422                         continue;
423                 if (dn_fib_dump_info(skb, NETLINK_CB(cb->skb).portid,
424                                 cb->nlh->nlmsg_seq,
425                                 RTM_NEWROUTE,
426                                 tb->n,
427                                 (f->fn_state & DN_S_ZOMBIE) ? 0 : f->fn_type,
428                                 f->fn_scope, &f->fn_key, dz->dz_order,
429                                 f->fn_info, NLM_F_MULTI) < 0) {
430                         cb->args[4] = i;
431                         return -1;
432                 }
433         }
434         cb->args[4] = i;
435         return skb->len;
436 }
437 
438 static __inline__ int dn_hash_dump_zone(struct sk_buff *skb,
439                                 struct netlink_callback *cb,
440                                 struct dn_fib_table *tb,
441                                 struct dn_zone *dz)
442 {
443         int h, s_h;
444 
445         s_h = cb->args[3];
446         for(h = 0; h < dz->dz_divisor; h++) {
447                 if (h < s_h)
448                         continue;
449                 if (h > s_h)
450                         memset(&cb->args[4], 0, sizeof(cb->args) - 4*sizeof(cb->args[0]));
451                 if (dz->dz_hash == NULL || dz->dz_hash[h] == NULL)
452                         continue;
453                 if (dn_hash_dump_bucket(skb, cb, tb, dz, dz->dz_hash[h]) < 0) {
454                         cb->args[3] = h;
455                         return -1;
456                 }
457         }
458         cb->args[3] = h;
459         return skb->len;
460 }
461 
462 static int dn_fib_table_dump(struct dn_fib_table *tb, struct sk_buff *skb,
463                                 struct netlink_callback *cb)
464 {
465         int m, s_m;
466         struct dn_zone *dz;
467         struct dn_hash *table = (struct dn_hash *)tb->data;
468 
469         s_m = cb->args[2];
470         read_lock(&dn_fib_tables_lock);
471         for(dz = table->dh_zone_list, m = 0; dz; dz = dz->dz_next, m++) {
472                 if (m < s_m)
473                         continue;
474                 if (m > s_m)
475                         memset(&cb->args[3], 0, sizeof(cb->args) - 3*sizeof(cb->args[0]));
476 
477                 if (dn_hash_dump_zone(skb, cb, tb, dz) < 0) {
478                         cb->args[2] = m;
479                         read_unlock(&dn_fib_tables_lock);
480                         return -1;
481                 }
482         }
483         read_unlock(&dn_fib_tables_lock);
484         cb->args[2] = m;
485 
486         return skb->len;
487 }
488 
489 int dn_fib_dump(struct sk_buff *skb, struct netlink_callback *cb)
490 {
491         struct net *net = sock_net(skb->sk);
492         unsigned int h, s_h;
493         unsigned int e = 0, s_e;
494         struct dn_fib_table *tb;
495         int dumped = 0;
496 
497         if (!net_eq(net, &init_net))
498                 return 0;
499 
500         if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
501                 ((struct rtmsg *)nlmsg_data(cb->nlh))->rtm_flags&RTM_F_CLONED)
502                         return dn_cache_dump(skb, cb);
503 
504         s_h = cb->args[0];
505         s_e = cb->args[1];
506 
507         for (h = s_h; h < DN_FIB_TABLE_HASHSZ; h++, s_h = 0) {
508                 e = 0;
509                 hlist_for_each_entry(tb, &dn_fib_table_hash[h], hlist) {
510                         if (e < s_e)
511                                 goto next;
512                         if (dumped)
513                                 memset(&cb->args[2], 0, sizeof(cb->args) -
514                                                  2 * sizeof(cb->args[0]));
515                         if (tb->dump(tb, skb, cb) < 0)
516                                 goto out;
517                         dumped = 1;
518 next:
519                         e++;
520                 }
521         }
522 out:
523         cb->args[1] = e;
524         cb->args[0] = h;
525 
526         return skb->len;
527 }
528 
529 static int dn_fib_table_insert(struct dn_fib_table *tb, struct rtmsg *r, struct nlattr *attrs[],
530                                struct nlmsghdr *n, struct netlink_skb_parms *req)
531 {
532         struct dn_hash *table = (struct dn_hash *)tb->data;
533         struct dn_fib_node *new_f, *f, **fp, **del_fp;
534         struct dn_zone *dz;
535         struct dn_fib_info *fi;
536         int z = r->rtm_dst_len;
537         int type = r->rtm_type;
538         dn_fib_key_t key;
539         int err;
540 
541         if (z > 16)
542                 return -EINVAL;
543 
544         dz = table->dh_zones[z];
545         if (!dz && !(dz = dn_new_zone(table, z)))
546                 return -ENOBUFS;
547 
548         dz_key_0(key);
549         if (attrs[RTA_DST]) {
550                 __le16 dst = nla_get_le16(attrs[RTA_DST]);
551                 if (dst & ~DZ_MASK(dz))
552                         return -EINVAL;
553                 key = dz_key(dst, dz);
554         }
555 
556         if ((fi = dn_fib_create_info(r, attrs, n, &err)) == NULL)
557                 return err;
558 
559         if (dz->dz_nent > (dz->dz_divisor << 2) &&
560                         dz->dz_divisor > DN_MAX_DIVISOR &&
561                         (z==16 || (1<<z) > dz->dz_divisor))
562                 dn_rehash_zone(dz);
563 
564         fp = dn_chain_p(key, dz);
565 
566         DN_FIB_SCAN(f, fp) {
567                 if (dn_key_leq(key, f->fn_key))
568                         break;
569         }
570 
571         del_fp = NULL;
572 
573         if (f && (f->fn_state & DN_S_ZOMBIE) &&
574                         dn_key_eq(f->fn_key, key)) {
575                 del_fp = fp;
576                 fp = &f->fn_next;
577                 f = *fp;
578                 goto create;
579         }
580 
581         DN_FIB_SCAN_KEY(f, fp, key) {
582                 if (fi->fib_priority <= DN_FIB_INFO(f)->fib_priority)
583                         break;
584         }
585 
586         if (f && dn_key_eq(f->fn_key, key) &&
587                         fi->fib_priority == DN_FIB_INFO(f)->fib_priority) {
588                 struct dn_fib_node **ins_fp;
589 
590                 err = -EEXIST;
591                 if (n->nlmsg_flags & NLM_F_EXCL)
592                         goto out;
593 
594                 if (n->nlmsg_flags & NLM_F_REPLACE) {
595                         del_fp = fp;
596                         fp = &f->fn_next;
597                         f = *fp;
598                         goto replace;
599                 }
600 
601                 ins_fp = fp;
602                 err = -EEXIST;
603 
604                 DN_FIB_SCAN_KEY(f, fp, key) {
605                         if (fi->fib_priority != DN_FIB_INFO(f)->fib_priority)
606                                 break;
607                         if (f->fn_type == type &&
608                             f->fn_scope == r->rtm_scope &&
609                             DN_FIB_INFO(f) == fi)
610                                 goto out;
611                 }
612 
613                 if (!(n->nlmsg_flags & NLM_F_APPEND)) {
614                         fp = ins_fp;
615                         f = *fp;
616                 }
617         }
618 
619 create:
620         err = -ENOENT;
621         if (!(n->nlmsg_flags & NLM_F_CREATE))
622                 goto out;
623 
624 replace:
625         err = -ENOBUFS;
626         new_f = kmem_cache_zalloc(dn_hash_kmem, GFP_KERNEL);
627         if (new_f == NULL)
628                 goto out;
629 
630         new_f->fn_key = key;
631         new_f->fn_type = type;
632         new_f->fn_scope = r->rtm_scope;
633         DN_FIB_INFO(new_f) = fi;
634 
635         new_f->fn_next = f;
636         write_lock_bh(&dn_fib_tables_lock);
637         *fp = new_f;
638         write_unlock_bh(&dn_fib_tables_lock);
639         dz->dz_nent++;
640 
641         if (del_fp) {
642                 f = *del_fp;
643                 write_lock_bh(&dn_fib_tables_lock);
644                 *del_fp = f->fn_next;
645                 write_unlock_bh(&dn_fib_tables_lock);
646 
647                 if (!(f->fn_state & DN_S_ZOMBIE))
648                         dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
649                 if (f->fn_state & DN_S_ACCESSED)
650                         dn_rt_cache_flush(-1);
651                 dn_free_node(f);
652                 dz->dz_nent--;
653         } else {
654                 dn_rt_cache_flush(-1);
655         }
656 
657         dn_rtmsg_fib(RTM_NEWROUTE, new_f, z, tb->n, n, req);
658 
659         return 0;
660 out:
661         dn_fib_release_info(fi);
662         return err;
663 }
664 
665 
666 static int dn_fib_table_delete(struct dn_fib_table *tb, struct rtmsg *r, struct nlattr *attrs[],
667                                struct nlmsghdr *n, struct netlink_skb_parms *req)
668 {
669         struct dn_hash *table = (struct dn_hash*)tb->data;
670         struct dn_fib_node **fp, **del_fp, *f;
671         int z = r->rtm_dst_len;
672         struct dn_zone *dz;
673         dn_fib_key_t key;
674         int matched;
675 
676 
677         if (z > 16)
678                 return -EINVAL;
679 
680         if ((dz = table->dh_zones[z]) == NULL)
681                 return -ESRCH;
682 
683         dz_key_0(key);
684         if (attrs[RTA_DST]) {
685                 __le16 dst = nla_get_le16(attrs[RTA_DST]);
686                 if (dst & ~DZ_MASK(dz))
687                         return -EINVAL;
688                 key = dz_key(dst, dz);
689         }
690 
691         fp = dn_chain_p(key, dz);
692 
693         DN_FIB_SCAN(f, fp) {
694                 if (dn_key_eq(f->fn_key, key))
695                         break;
696                 if (dn_key_leq(key, f->fn_key))
697                         return -ESRCH;
698         }
699 
700         matched = 0;
701         del_fp = NULL;
702         DN_FIB_SCAN_KEY(f, fp, key) {
703                 struct dn_fib_info *fi = DN_FIB_INFO(f);
704 
705                 if (f->fn_state & DN_S_ZOMBIE)
706                         return -ESRCH;
707 
708                 matched++;
709 
710                 if (del_fp == NULL &&
711                                 (!r->rtm_type || f->fn_type == r->rtm_type) &&
712                                 (r->rtm_scope == RT_SCOPE_NOWHERE || f->fn_scope == r->rtm_scope) &&
713                                 (!r->rtm_protocol ||
714                                         fi->fib_protocol == r->rtm_protocol) &&
715                                 dn_fib_nh_match(r, n, attrs, fi) == 0)
716                         del_fp = fp;
717         }
718 
719         if (del_fp) {
720                 f = *del_fp;
721                 dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
722 
723                 if (matched != 1) {
724                         write_lock_bh(&dn_fib_tables_lock);
725                         *del_fp = f->fn_next;
726                         write_unlock_bh(&dn_fib_tables_lock);
727 
728                         if (f->fn_state & DN_S_ACCESSED)
729                                 dn_rt_cache_flush(-1);
730                         dn_free_node(f);
731                         dz->dz_nent--;
732                 } else {
733                         f->fn_state |= DN_S_ZOMBIE;
734                         if (f->fn_state & DN_S_ACCESSED) {
735                                 f->fn_state &= ~DN_S_ACCESSED;
736                                 dn_rt_cache_flush(-1);
737                         }
738                         if (++dn_fib_hash_zombies > 128)
739                                 dn_fib_flush();
740                 }
741 
742                 return 0;
743         }
744 
745         return -ESRCH;
746 }
747 
748 static inline int dn_flush_list(struct dn_fib_node **fp, int z, struct dn_hash *table)
749 {
750         int found = 0;
751         struct dn_fib_node *f;
752 
753         while((f = *fp) != NULL) {
754                 struct dn_fib_info *fi = DN_FIB_INFO(f);
755 
756                 if (fi && ((f->fn_state & DN_S_ZOMBIE) || (fi->fib_flags & RTNH_F_DEAD))) {
757                         write_lock_bh(&dn_fib_tables_lock);
758                         *fp = f->fn_next;
759                         write_unlock_bh(&dn_fib_tables_lock);
760 
761                         dn_free_node(f);
762                         found++;
763                         continue;
764                 }
765                 fp = &f->fn_next;
766         }
767 
768         return found;
769 }
770 
771 static int dn_fib_table_flush(struct dn_fib_table *tb)
772 {
773         struct dn_hash *table = (struct dn_hash *)tb->data;
774         struct dn_zone *dz;
775         int found = 0;
776 
777         dn_fib_hash_zombies = 0;
778         for(dz = table->dh_zone_list; dz; dz = dz->dz_next) {
779                 int i;
780                 int tmp = 0;
781                 for(i = dz->dz_divisor-1; i >= 0; i--)
782                         tmp += dn_flush_list(&dz->dz_hash[i], dz->dz_order, table);
783                 dz->dz_nent -= tmp;
784                 found += tmp;
785         }
786 
787         return found;
788 }
789 
790 static int dn_fib_table_lookup(struct dn_fib_table *tb, const struct flowidn *flp, struct dn_fib_res *res)
791 {
792         int err;
793         struct dn_zone *dz;
794         struct dn_hash *t = (struct dn_hash *)tb->data;
795 
796         read_lock(&dn_fib_tables_lock);
797         for(dz = t->dh_zone_list; dz; dz = dz->dz_next) {
798                 struct dn_fib_node *f;
799                 dn_fib_key_t k = dz_key(flp->daddr, dz);
800 
801                 for(f = dz_chain(k, dz); f; f = f->fn_next) {
802                         if (!dn_key_eq(k, f->fn_key)) {
803                                 if (dn_key_leq(k, f->fn_key))
804                                         break;
805                                 else
806                                         continue;
807                         }
808 
809                         f->fn_state |= DN_S_ACCESSED;
810 
811                         if (f->fn_state&DN_S_ZOMBIE)
812                                 continue;
813 
814                         if (f->fn_scope < flp->flowidn_scope)
815                                 continue;
816 
817                         err = dn_fib_semantic_match(f->fn_type, DN_FIB_INFO(f), flp, res);
818 
819                         if (err == 0) {
820                                 res->type = f->fn_type;
821                                 res->scope = f->fn_scope;
822                                 res->prefixlen = dz->dz_order;
823                                 goto out;
824                         }
825                         if (err < 0)
826                                 goto out;
827                 }
828         }
829         err = 1;
830 out:
831         read_unlock(&dn_fib_tables_lock);
832         return err;
833 }
834 
835 
836 struct dn_fib_table *dn_fib_get_table(u32 n, int create)
837 {
838         struct dn_fib_table *t;
839         unsigned int h;
840 
841         if (n < RT_TABLE_MIN)
842                 return NULL;
843 
844         if (n > RT_TABLE_MAX)
845                 return NULL;
846 
847         h = n & (DN_FIB_TABLE_HASHSZ - 1);
848         rcu_read_lock();
849         hlist_for_each_entry_rcu(t, &dn_fib_table_hash[h], hlist) {
850                 if (t->n == n) {
851                         rcu_read_unlock();
852                         return t;
853                 }
854         }
855         rcu_read_unlock();
856 
857         if (!create)
858                 return NULL;
859 
860         if (in_interrupt()) {
861                 net_dbg_ratelimited("DECnet: BUG! Attempt to create routing table from interrupt\n");
862                 return NULL;
863         }
864 
865         t = kzalloc(sizeof(struct dn_fib_table) + sizeof(struct dn_hash),
866                     GFP_KERNEL);
867         if (t == NULL)
868                 return NULL;
869 
870         t->n = n;
871         t->insert = dn_fib_table_insert;
872         t->delete = dn_fib_table_delete;
873         t->lookup = dn_fib_table_lookup;
874         t->flush  = dn_fib_table_flush;
875         t->dump = dn_fib_table_dump;
876         hlist_add_head_rcu(&t->hlist, &dn_fib_table_hash[h]);
877 
878         return t;
879 }
880 
881 struct dn_fib_table *dn_fib_empty_table(void)
882 {
883         u32 id;
884 
885         for(id = RT_TABLE_MIN; id <= RT_TABLE_MAX; id++)
886                 if (dn_fib_get_table(id, 0) == NULL)
887                         return dn_fib_get_table(id, 1);
888         return NULL;
889 }
890 
891 void dn_fib_flush(void)
892 {
893         int flushed = 0;
894         struct dn_fib_table *tb;
895         unsigned int h;
896 
897         for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
898                 hlist_for_each_entry(tb, &dn_fib_table_hash[h], hlist)
899                         flushed += tb->flush(tb);
900         }
901 
902         if (flushed)
903                 dn_rt_cache_flush(-1);
904 }
905 
906 void __init dn_fib_table_init(void)
907 {
908         dn_hash_kmem = kmem_cache_create("dn_fib_info_cache",
909                                         sizeof(struct dn_fib_info),
910                                         0, SLAB_HWCACHE_ALIGN,
911                                         NULL);
912 }
913 
914 void __exit dn_fib_table_cleanup(void)
915 {
916         struct dn_fib_table *t;
917         struct hlist_node *next;
918         unsigned int h;
919 
920         write_lock(&dn_fib_tables_lock);
921         for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
922                 hlist_for_each_entry_safe(t, next, &dn_fib_table_hash[h],
923                                           hlist) {
924                         hlist_del(&t->hlist);
925                         kfree(t);
926                 }
927         }
928         write_unlock(&dn_fib_tables_lock);
929 }
930 

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