net/decnet/dn_table.c

   1 /*
   2  * DECnet       An implementation of the DECnet protocol suite for the LINUX
   3  *              operating system.  DECnet is implemented using the  BSD Socket
   4  *              interface as the means of communication with the user level.
   5  *
   6  *              DECnet Routing Forwarding Information Base (Routing Tables)
   7  *
   8  * Author:      Steve Whitehouse <SteveW@ACM.org>
   9  *              Mostly copied from the IPv4 routing code
  10  *
  11  *
  12  * Changes:
  13  *
  14  */
  15 #include <linux/string.h>
  16 #include <linux/net.h>
  17 #include <linux/socket.h>
  18 #include <linux/sockios.h>
  19 #include <linux/init.h>
  20 #include <linux/skbuff.h>
  21 #include <linux/netlink.h>
  22 #include <linux/rtnetlink.h>
  23 #include <linux/proc_fs.h>
  24 #include <linux/netdevice.h>
  25 #include <linux/timer.h>
  26 #include <linux/spinlock.h>
  27 #include <asm/atomic.h>
  28 #include <asm/uaccess.h>
  29 #include <linux/route.h> /* RTF_xxx */
  30 #include <net/neighbour.h>
  31 #include <net/dst.h>
  32 #include <net/flow.h>
  33 #include <net/dn.h>
  34 #include <net/dn_route.h>
  35 #include <net/dn_fib.h>
  36 #include <net/dn_neigh.h>
  37 #include <net/dn_dev.h>
  38
  39 struct dn_zone
  40 {
  41         struct dn_zone          *dz_next;
  42         struct dn_fib_node      **dz_hash;
  43         int                     dz_nent;
  44         int                     dz_divisor;
  45         u32                     dz_hashmask;
  46 #define DZ_HASHMASK(dz) ((dz)->dz_hashmask)
  47         int                     dz_order;
  48         __le16                  dz_mask;
  49 #define DZ_MASK(dz)     ((dz)->dz_mask)
  50 };
  51
  52 struct dn_hash
  53 {
  54         struct dn_zone  *dh_zones[17];
  55         struct dn_zone  *dh_zone_list;
  56 };
  57
  58 #define dz_key_0(key)           ((key).datum = 0)
  59 #define dz_prefix(key,dz)       ((key).datum)
  60
  61 #define for_nexthops(fi) { int nhsel; const struct dn_fib_nh *nh;\
  62         for(nhsel = 0, nh = (fi)->fib_nh; nhsel < (fi)->fib_nhs; nh++, nhsel++)
  63
  64 #define endfor_nexthops(fi) }
  65
  66 #define DN_MAX_DIVISOR 1024
  67 #define DN_S_ZOMBIE 1
  68 #define DN_S_ACCESSED 2
  69
  70 #define DN_FIB_SCAN(f, fp) \
  71 for( ; ((f) = *(fp)) != NULL; (fp) = &(f)->fn_next)
  72
  73 #define DN_FIB_SCAN_KEY(f, fp, key) \
  74 for( ; ((f) = *(fp)) != NULL && dn_key_eq((f)->fn_key, (key)); (fp) = &(f)->fn_next)
  75
  76 #define RT_TABLE_MIN 1
  77
  78 static DEFINE_RWLOCK(dn_fib_tables_lock);
  79 struct dn_fib_table *dn_fib_tables[RT_TABLE_MAX + 1];
  80
  81 static kmem_cache_t *dn_hash_kmem __read_mostly;
  82 static int dn_fib_hash_zombies;
  83
  84 static inline dn_fib_idx_t dn_hash(dn_fib_key_t key, struct dn_zone *dz)
  85 {
  86         u16 h = dn_ntohs(key.datum)>>(16 - dz->dz_order);
  87         h ^= (h >> 10);
  88         h ^= (h >> 6);
  89         h &= DZ_HASHMASK(dz);
  90         return *(dn_fib_idx_t *)&h;
  91 }
  92
  93 static inline dn_fib_key_t dz_key(__le16 dst, struct dn_zone *dz)
  94 {
  95         dn_fib_key_t k;
  96         k.datum = dst & DZ_MASK(dz);
  97         return k;
  98 }
  99
 100 static inline struct dn_fib_node **dn_chain_p(dn_fib_key_t key, struct dn_zone *dz)
 101 {
 102         return &dz->dz_hash[dn_hash(key, dz).datum];
 103 }
 104
 105 static inline struct dn_fib_node *dz_chain(dn_fib_key_t key, struct dn_zone *dz)
 106 {
 107         return dz->dz_hash[dn_hash(key, dz).datum];
 108 }
 109
 110 static inline int dn_key_eq(dn_fib_key_t a, dn_fib_key_t b)
 111 {
 112         return a.datum == b.datum;
 113 }
 114
 115 static inline int dn_key_leq(dn_fib_key_t a, dn_fib_key_t b)
 116 {
 117         return a.datum <= b.datum;
 118 }
 119
 120 static inline void dn_rebuild_zone(struct dn_zone *dz,
 121                                    struct dn_fib_node **old_ht,
 122                                    int old_divisor)
 123 {
 124         int i;
 125         struct dn_fib_node *f, **fp, *next;
 126
 127         for(i = 0; i < old_divisor; i++) {
 128                 for(f = old_ht[i]; f; f = f->fn_next) {
 129                         next = f->fn_next;
 130                         for(fp = dn_chain_p(f->fn_key, dz);
 131                                 *fp && dn_key_leq((*fp)->fn_key, f->fn_key);
 132                                 fp = &(*fp)->fn_next)
 133                                 /* NOTHING */;
 134                         f->fn_next = *fp;
 135                         *fp = f;
 136                 }
 137         }
 138 }
 139
 140 static void dn_rehash_zone(struct dn_zone *dz)
 141 {
 142         struct dn_fib_node **ht, **old_ht;
 143         int old_divisor, new_divisor;
 144         u32 new_hashmask;
 145
 146         old_divisor = dz->dz_divisor;
 147
 148         switch(old_divisor) {
 149                 case 16:
 150                         new_divisor = 256;
 151                         new_hashmask = 0xFF;
 152                         break;
 153                 default:
 154                         printk(KERN_DEBUG "DECnet: dn_rehash_zone: BUG! %d\n", old_divisor);
 155                 case 256:
 156                         new_divisor = 1024;
 157                         new_hashmask = 0x3FF;
 158                         break;
 159         }
 160
 161         ht = kcalloc(new_divisor, sizeof(struct dn_fib_node*), GFP_KERNEL);
 162         if (ht == NULL)
 163                 return;
 164
 165         write_lock_bh(&dn_fib_tables_lock);
 166         old_ht = dz->dz_hash;
 167         dz->dz_hash = ht;
 168         dz->dz_hashmask = new_hashmask;
 169         dz->dz_divisor = new_divisor;
 170         dn_rebuild_zone(dz, old_ht, old_divisor);
 171         write_unlock_bh(&dn_fib_tables_lock);
 172         kfree(old_ht);
 173 }
 174
 175 static void dn_free_node(struct dn_fib_node *f)
 176 {
 177         dn_fib_release_info(DN_FIB_INFO(f));
 178         kmem_cache_free(dn_hash_kmem, f);
 179 }
 180
 181
 182 static struct dn_zone *dn_new_zone(struct dn_hash *table, int z)
 183 {
 184         int i;
 185         struct dn_zone *dz = kzalloc(sizeof(struct dn_zone), GFP_KERNEL);
 186         if (!dz)
 187                 return NULL;
 188
 189         if (z) {
 190                 dz->dz_divisor = 16;
 191                 dz->dz_hashmask = 0x0F;
 192         } else {
 193                 dz->dz_divisor = 1;
 194                 dz->dz_hashmask = 0;
 195         }
 196
 197         dz->dz_hash = kcalloc(dz->dz_divisor, sizeof(struct dn_fib_node *), GFP_KERNEL);
 198         if (!dz->dz_hash) {
 199                 kfree(dz);
 200                 return NULL;
 201         }
 202
 203         dz->dz_order = z;
 204         dz->dz_mask = dnet_make_mask(z);
 205
 206         for(i = z + 1; i <= 16; i++)
 207                 if (table->dh_zones[i])
 208                         break;
 209
 210         write_lock_bh(&dn_fib_tables_lock);
 211         if (i>16) {
 212                 dz->dz_next = table->dh_zone_list;
 213                 table->dh_zone_list = dz;
 214         } else {
 215                 dz->dz_next = table->dh_zones[i]->dz_next;
 216                 table->dh_zones[i]->dz_next = dz;
 217         }
 218         table->dh_zones[z] = dz;
 219         write_unlock_bh(&dn_fib_tables_lock);
 220         return dz;
 221 }
 222
 223
 224 static int dn_fib_nh_match(struct rtmsg *r, struct nlmsghdr *nlh, struct dn_kern_rta *rta, struct dn_fib_info *fi)
 225 {
 226         struct rtnexthop *nhp;
 227         int nhlen;
 228
 229         if (rta->rta_priority && *rta->rta_priority != fi->fib_priority)
 230                 return 1;
 231
 232         if (rta->rta_oif || rta->rta_gw) {
 233                 if ((!rta->rta_oif || *rta->rta_oif == fi->fib_nh->nh_oif) &&
 234                     (!rta->rta_gw  || memcmp(rta->rta_gw, &fi->fib_nh->nh_gw, 2) == 0))
 235                         return 0;
 236                 return 1;
 237         }
 238
 239         if (rta->rta_mp == NULL)
 240                 return 0;
 241
 242         nhp = RTA_DATA(rta->rta_mp);
 243         nhlen = RTA_PAYLOAD(rta->rta_mp);
 244
 245         for_nexthops(fi) {
 246                 int attrlen = nhlen - sizeof(struct rtnexthop);
 247                 __le16 gw;
 248
 249                 if (attrlen < 0 || (nhlen -= nhp->rtnh_len) < 0)
 250                         return -EINVAL;
 251                 if (nhp->rtnh_ifindex && nhp->rtnh_ifindex != nh->nh_oif)
 252                         return 1;
 253                 if (attrlen) {
 254                         gw = dn_fib_get_attr16(RTNH_DATA(nhp), attrlen, RTA_GATEWAY);
 255
 256                         if (gw && gw != nh->nh_gw)
 257                                 return 1;
 258                 }
 259                 nhp = RTNH_NEXT(nhp);
 260         } endfor_nexthops(fi);
 261
 262         return 0;
 263 }
 264
 265 static int dn_fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
 266                         u8 tb_id, u8 type, u8 scope, void *dst, int dst_len,
 267                         struct dn_fib_info *fi, unsigned int flags)
 268 {
 269         struct rtmsg *rtm;
 270         struct nlmsghdr *nlh;
 271         unsigned char *b = skb->tail;
 272
 273         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*rtm), flags);
 274         rtm = NLMSG_DATA(nlh);
 275         rtm->rtm_family = AF_DECnet;
 276         rtm->rtm_dst_len = dst_len;
 277         rtm->rtm_src_len = 0;
 278         rtm->rtm_tos = 0;
 279         rtm->rtm_table = tb_id;
 280         rtm->rtm_flags = fi->fib_flags;
 281         rtm->rtm_scope = scope;
 282         rtm->rtm_type  = type;
 283         if (rtm->rtm_dst_len)
 284                 RTA_PUT(skb, RTA_DST, 2, dst);
 285         rtm->rtm_protocol = fi->fib_protocol;
 286         if (fi->fib_priority)
 287                 RTA_PUT(skb, RTA_PRIORITY, 4, &fi->fib_priority);
 288         if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0)
 289                 goto rtattr_failure;
 290         if (fi->fib_nhs == 1) {
 291                 if (fi->fib_nh->nh_gw)
 292                         RTA_PUT(skb, RTA_GATEWAY, 2, &fi->fib_nh->nh_gw);
 293                 if (fi->fib_nh->nh_oif)
 294                         RTA_PUT(skb, RTA_OIF, sizeof(int), &fi->fib_nh->nh_oif);
 295         }
 296         if (fi->fib_nhs > 1) {
 297                 struct rtnexthop *nhp;
 298                 struct rtattr *mp_head;
 299                 if (skb_tailroom(skb) <= RTA_SPACE(0))
 300                         goto rtattr_failure;
 301                 mp_head = (struct rtattr *)skb_put(skb, RTA_SPACE(0));
 302
 303                 for_nexthops(fi) {
 304                         if (skb_tailroom(skb) < RTA_ALIGN(RTA_ALIGN(sizeof(*nhp)) + 4))
 305                                 goto rtattr_failure;
 306                         nhp = (struct rtnexthop *)skb_put(skb, RTA_ALIGN(sizeof(*nhp)));
 307                         nhp->rtnh_flags = nh->nh_flags & 0xFF;
 308                         nhp->rtnh_hops = nh->nh_weight - 1;
 309                         nhp->rtnh_ifindex = nh->nh_oif;
 310                         if (nh->nh_gw)
 311                                 RTA_PUT(skb, RTA_GATEWAY, 2, &nh->nh_gw);
 312                         nhp->rtnh_len = skb->tail - (unsigned char *)nhp;
 313                 } endfor_nexthops(fi);
 314                 mp_head->rta_type = RTA_MULTIPATH;
 315                 mp_head->rta_len = skb->tail - (u8*)mp_head;
 316         }
 317
 318         nlh->nlmsg_len = skb->tail - b;
 319         return skb->len;
 320
 321
 322 nlmsg_failure:
 323 rtattr_failure:
 324         skb_trim(skb, b - skb->data);
 325         return -1;
 326 }
 327
 328
 329 static void dn_rtmsg_fib(int event, struct dn_fib_node *f, int z, int tb_id,
 330                         struct nlmsghdr *nlh, struct netlink_skb_parms *req)
 331 {
 332         struct sk_buff *skb;
 333         u32 pid = req ? req->pid : 0;
 334         int size = NLMSG_SPACE(sizeof(struct rtmsg) + 256);
 335
 336         skb = alloc_skb(size, GFP_KERNEL);
 337         if (!skb)
 338                 return;
 339
 340         if (dn_fib_dump_info(skb, pid, nlh->nlmsg_seq, event, tb_id,
 341                                 f->fn_type, f->fn_scope, &f->fn_key, z,
 342                                 DN_FIB_INFO(f), 0) < 0) {
 343                 kfree_skb(skb);
 344                 return;
 345         }
 346         NETLINK_CB(skb).dst_group = RTNLGRP_DECnet_ROUTE;
 347         if (nlh->nlmsg_flags & NLM_F_ECHO)
 348                 atomic_inc(&skb->users);
 349         netlink_broadcast(rtnl, skb, pid, RTNLGRP_DECnet_ROUTE, GFP_KERNEL);
 350         if (nlh->nlmsg_flags & NLM_F_ECHO)
 351                 netlink_unicast(rtnl, skb, pid, MSG_DONTWAIT);
 352 }
 353
 354 static __inline__ int dn_hash_dump_bucket(struct sk_buff *skb,
 355                                 struct netlink_callback *cb,
 356                                 struct dn_fib_table *tb,
 357                                 struct dn_zone *dz,
 358                                 struct dn_fib_node *f)
 359 {
 360         int i, s_i;
 361
 362         s_i = cb->args[3];
 363         for(i = 0; f; i++, f = f->fn_next) {
 364                 if (i < s_i)
 365                         continue;
 366                 if (f->fn_state & DN_S_ZOMBIE)
 367                         continue;
 368                 if (dn_fib_dump_info(skb, NETLINK_CB(cb->skb).pid,
 369                                 cb->nlh->nlmsg_seq,
 370                                 RTM_NEWROUTE,
 371                                 tb->n,
 372                                 (f->fn_state & DN_S_ZOMBIE) ? 0 : f->fn_type,
 373                                 f->fn_scope, &f->fn_key, dz->dz_order,
 374                                 f->fn_info, NLM_F_MULTI) < 0) {
 375                         cb->args[3] = i;
 376                         return -1;
 377                 }
 378         }
 379         cb->args[3] = i;
 380         return skb->len;
 381 }
 382
 383 static __inline__ int dn_hash_dump_zone(struct sk_buff *skb,
 384                                 struct netlink_callback *cb,
 385                                 struct dn_fib_table *tb,
 386                                 struct dn_zone *dz)
 387 {
 388         int h, s_h;
 389
 390         s_h = cb->args[2];
 391         for(h = 0; h < dz->dz_divisor; h++) {
 392                 if (h < s_h)
 393                         continue;
 394                 if (h > s_h)
 395                         memset(&cb->args[3], 0, sizeof(cb->args) - 3*sizeof(cb->args[0]));
 396                 if (dz->dz_hash == NULL || dz->dz_hash[h] == NULL)
 397                         continue;
 398                 if (dn_hash_dump_bucket(skb, cb, tb, dz, dz->dz_hash[h]) < 0) {
 399                         cb->args[2] = h;
 400                         return -1;
 401                 }
 402         }
 403         cb->args[2] = h;
 404         return skb->len;
 405 }
 406
 407 static int dn_fib_table_dump(struct dn_fib_table *tb, struct sk_buff *skb,
 408                                 struct netlink_callback *cb)
 409 {
 410         int m, s_m;
 411         struct dn_zone *dz;
 412         struct dn_hash *table = (struct dn_hash *)tb->data;
 413
 414         s_m = cb->args[1];
 415         read_lock(&dn_fib_tables_lock);
 416         for(dz = table->dh_zone_list, m = 0; dz; dz = dz->dz_next, m++) {
 417                 if (m < s_m)
 418                         continue;
 419                 if (m > s_m)
 420                         memset(&cb->args[2], 0, sizeof(cb->args) - 2*sizeof(cb->args[0]));
 421
 422                 if (dn_hash_dump_zone(skb, cb, tb, dz) < 0) {
 423                         cb->args[1] = m;
 424                         read_unlock(&dn_fib_tables_lock);
 425                         return -1;
 426                 }
 427         }
 428         read_unlock(&dn_fib_tables_lock);
 429         cb->args[1] = m;
 430
 431         return skb->len;
 432 }
 433
 434 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)
 435 {
 436         struct dn_hash *table = (struct dn_hash *)tb->data;
 437         struct dn_fib_node *new_f, *f, **fp, **del_fp;
 438         struct dn_zone *dz;
 439         struct dn_fib_info *fi;
 440         int z = r->rtm_dst_len;
 441         int type = r->rtm_type;
 442         dn_fib_key_t key;
 443         int err;
 444
 445         if (z > 16)
 446                 return -EINVAL;
 447
 448         dz = table->dh_zones[z];
 449         if (!dz && !(dz = dn_new_zone(table, z)))
 450                 return -ENOBUFS;
 451
 452         dz_key_0(key);
 453         if (rta->rta_dst) {
 454                 __le16 dst;
 455                 memcpy(&dst, rta->rta_dst, 2);
 456                 if (dst & ~DZ_MASK(dz))
 457                         return -EINVAL;
 458                 key = dz_key(dst, dz);
 459         }
 460
 461         if ((fi = dn_fib_create_info(r, rta, n, &err)) == NULL)
 462                 return err;
 463
 464         if (dz->dz_nent > (dz->dz_divisor << 2) &&
 465                         dz->dz_divisor > DN_MAX_DIVISOR &&
 466                         (z==16 || (1<<z) > dz->dz_divisor))
 467                 dn_rehash_zone(dz);
 468
 469         fp = dn_chain_p(key, dz);
 470
 471         DN_FIB_SCAN(f, fp) {
 472                 if (dn_key_leq(key, f->fn_key))
 473                         break;
 474         }
 475
 476         del_fp = NULL;
 477
 478         if (f && (f->fn_state & DN_S_ZOMBIE) &&
 479                         dn_key_eq(f->fn_key, key)) {
 480                 del_fp = fp;
 481                 fp = &f->fn_next;
 482                 f = *fp;
 483                 goto create;
 484         }
 485
 486         DN_FIB_SCAN_KEY(f, fp, key) {
 487                 if (fi->fib_priority <= DN_FIB_INFO(f)->fib_priority)
 488                         break;
 489         }
 490
 491         if (f && dn_key_eq(f->fn_key, key) &&
 492                         fi->fib_priority == DN_FIB_INFO(f)->fib_priority) {
 493                 struct dn_fib_node **ins_fp;
 494
 495                 err = -EEXIST;
 496                 if (n->nlmsg_flags & NLM_F_EXCL)
 497                         goto out;
 498
 499                 if (n->nlmsg_flags & NLM_F_REPLACE) {
 500                         del_fp = fp;
 501                         fp = &f->fn_next;
 502                         f = *fp;
 503                         goto replace;
 504                 }
 505
 506                 ins_fp = fp;
 507                 err = -EEXIST;
 508
 509                 DN_FIB_SCAN_KEY(f, fp, key) {
 510                         if (fi->fib_priority != DN_FIB_INFO(f)->fib_priority)
 511                                 break;
 512                         if (f->fn_type == type && f->fn_scope == r->rtm_scope
 513                                         && DN_FIB_INFO(f) == fi)
 514                                 goto out;
 515                 }
 516
 517                 if (!(n->nlmsg_flags & NLM_F_APPEND)) {
 518                         fp = ins_fp;
 519                         f = *fp;
 520                 }
 521         }
 522
 523 create:
 524         err = -ENOENT;
 525         if (!(n->nlmsg_flags & NLM_F_CREATE))
 526                 goto out;
 527
 528 replace:
 529         err = -ENOBUFS;
 530         new_f = kmem_cache_alloc(dn_hash_kmem, SLAB_KERNEL);
 531         if (new_f == NULL)
 532                 goto out;
 533
 534         memset(new_f, 0, sizeof(struct dn_fib_node));
 535
 536         new_f->fn_key = key;
 537         new_f->fn_type = type;
 538         new_f->fn_scope = r->rtm_scope;
 539         DN_FIB_INFO(new_f) = fi;
 540
 541         new_f->fn_next = f;
 542         write_lock_bh(&dn_fib_tables_lock);
 543         *fp = new_f;
 544         write_unlock_bh(&dn_fib_tables_lock);
 545         dz->dz_nent++;
 546
 547         if (del_fp) {
 548                 f = *del_fp;
 549                 write_lock_bh(&dn_fib_tables_lock);
 550                 *del_fp = f->fn_next;
 551                 write_unlock_bh(&dn_fib_tables_lock);
 552
 553                 if (!(f->fn_state & DN_S_ZOMBIE))
 554                         dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 555                 if (f->fn_state & DN_S_ACCESSED)
 556                         dn_rt_cache_flush(-1);
 557                 dn_free_node(f);
 558                 dz->dz_nent--;
 559         } else {
 560                 dn_rt_cache_flush(-1);
 561         }
 562
 563         dn_rtmsg_fib(RTM_NEWROUTE, new_f, z, tb->n, n, req);
 564
 565         return 0;
 566 out:
 567         dn_fib_release_info(fi);
 568         return err;
 569 }
 570
 571
 572 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)
 573 {
 574         struct dn_hash *table = (struct dn_hash*)tb->data;
 575         struct dn_fib_node **fp, **del_fp, *f;
 576         int z = r->rtm_dst_len;
 577         struct dn_zone *dz;
 578         dn_fib_key_t key;
 579         int matched;
 580
 581
 582         if (z > 16)
 583                 return -EINVAL;
 584
 585         if ((dz = table->dh_zones[z]) == NULL)
 586                 return -ESRCH;
 587
 588         dz_key_0(key);
 589         if (rta->rta_dst) {
 590                 __le16 dst;
 591                 memcpy(&dst, rta->rta_dst, 2);
 592                 if (dst & ~DZ_MASK(dz))
 593                         return -EINVAL;
 594                 key = dz_key(dst, dz);
 595         }
 596
 597         fp = dn_chain_p(key, dz);
 598
 599         DN_FIB_SCAN(f, fp) {
 600                 if (dn_key_eq(f->fn_key, key))
 601                         break;
 602                 if (dn_key_leq(key, f->fn_key))
 603                         return -ESRCH;
 604         }
 605
 606         matched = 0;
 607         del_fp = NULL;
 608         DN_FIB_SCAN_KEY(f, fp, key) {
 609                 struct dn_fib_info *fi = DN_FIB_INFO(f);
 610
 611                 if (f->fn_state & DN_S_ZOMBIE)
 612                         return -ESRCH;
 613
 614                 matched++;
 615
 616                 if (del_fp == NULL &&
 617                                 (!r->rtm_type || f->fn_type == r->rtm_type) &&
 618                                 (r->rtm_scope == RT_SCOPE_NOWHERE || f->fn_scope == r->rtm_scope) &&
 619                                 (!r->rtm_protocol ||
 620                                         fi->fib_protocol == r->rtm_protocol) &&
 621                                 dn_fib_nh_match(r, n, rta, fi) == 0)
 622                         del_fp = fp;
 623         }
 624
 625         if (del_fp) {
 626                 f = *del_fp;
 627                 dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 628
 629                 if (matched != 1) {
 630                         write_lock_bh(&dn_fib_tables_lock);
 631                         *del_fp = f->fn_next;
 632                         write_unlock_bh(&dn_fib_tables_lock);
 633
 634                         if (f->fn_state & DN_S_ACCESSED)
 635                                 dn_rt_cache_flush(-1);
 636                         dn_free_node(f);
 637                         dz->dz_nent--;
 638                 } else {
 639                         f->fn_state |= DN_S_ZOMBIE;
 640                         if (f->fn_state & DN_S_ACCESSED) {
 641                                 f->fn_state &= ~DN_S_ACCESSED;
 642                                 dn_rt_cache_flush(-1);
 643                         }
 644                         if (++dn_fib_hash_zombies > 128)
 645                                 dn_fib_flush();
 646                 }
 647
 648                 return 0;
 649         }
 650
 651         return -ESRCH;
 652 }
 653
 654 static inline int dn_flush_list(struct dn_fib_node **fp, int z, struct dn_hash *table)
 655 {
 656         int found = 0;
 657         struct dn_fib_node *f;
 658
 659         while((f = *fp) != NULL) {
 660                 struct dn_fib_info *fi = DN_FIB_INFO(f);
 661
 662                 if (fi && ((f->fn_state & DN_S_ZOMBIE) || (fi->fib_flags & RTNH_F_DEAD))) {
 663                         write_lock_bh(&dn_fib_tables_lock);
 664                         *fp = f->fn_next;
 665                         write_unlock_bh(&dn_fib_tables_lock);
 666
 667                         dn_free_node(f);
 668                         found++;
 669                         continue;
 670                 }
 671                 fp = &f->fn_next;
 672         }
 673
 674         return found;
 675 }
 676
 677 static int dn_fib_table_flush(struct dn_fib_table *tb)
 678 {
 679         struct dn_hash *table = (struct dn_hash *)tb->data;
 680         struct dn_zone *dz;
 681         int found = 0;
 682
 683         dn_fib_hash_zombies = 0;
 684         for(dz = table->dh_zone_list; dz; dz = dz->dz_next) {
 685                 int i;
 686                 int tmp = 0;
 687                 for(i = dz->dz_divisor-1; i >= 0; i--)
 688                         tmp += dn_flush_list(&dz->dz_hash[i], dz->dz_order, table);
 689                 dz->dz_nent -= tmp;
 690                 found += tmp;
 691         }
 692
 693         return found;
 694 }
 695
 696 static int dn_fib_table_lookup(struct dn_fib_table *tb, const struct flowi *flp, struct dn_fib_res *res)
 697 {
 698         int err;
 699         struct dn_zone *dz;
 700         struct dn_hash *t = (struct dn_hash *)tb->data;
 701
 702         read_lock(&dn_fib_tables_lock);
 703         for(dz = t->dh_zone_list; dz; dz = dz->dz_next) {
 704                 struct dn_fib_node *f;
 705                 dn_fib_key_t k = dz_key(flp->fld_dst, dz);
 706
 707                 for(f = dz_chain(k, dz); f; f = f->fn_next) {
 708                         if (!dn_key_eq(k, f->fn_key)) {
 709                                 if (dn_key_leq(k, f->fn_key))
 710                                         break;
 711                                 else
 712                                         continue;
 713                         }
 714
 715                         f->fn_state |= DN_S_ACCESSED;
 716
 717                         if (f->fn_state&DN_S_ZOMBIE)
 718                                 continue;
 719
 720                         if (f->fn_scope < flp->fld_scope)
 721                                 continue;
 722
 723                         err = dn_fib_semantic_match(f->fn_type, DN_FIB_INFO(f), flp, res);
 724
 725                         if (err == 0) {
 726                                 res->type = f->fn_type;
 727                                 res->scope = f->fn_scope;
 728                                 res->prefixlen = dz->dz_order;
 729                                 goto out;
 730                         }
 731                         if (err < 0)
 732                                 goto out;
 733                 }
 734         }
 735         err = 1;
 736 out:
 737         read_unlock(&dn_fib_tables_lock);
 738         return err;
 739 }
 740
 741
 742 struct dn_fib_table *dn_fib_get_table(int n, int create)
 743 {
 744         struct dn_fib_table *t;
 745
 746         if (n < RT_TABLE_MIN)
 747                 return NULL;
 748
 749         if (n > RT_TABLE_MAX)
 750                 return NULL;
 751
 752         if (dn_fib_tables[n])
 753                 return dn_fib_tables[n];
 754
 755         if (!create)
 756                 return NULL;
 757
 758         if (in_interrupt() && net_ratelimit()) {
 759                 printk(KERN_DEBUG "DECnet: BUG! Attempt to create routing table from interrupt\n");
 760                 return NULL;
 761         }
 762         if ((t = kmalloc(sizeof(struct dn_fib_table) + sizeof(struct dn_hash), GFP_KERNEL)) == NULL)
 763                 return NULL;
 764
 765         memset(t, 0, sizeof(struct dn_fib_table));
 766
 767         t->n = n;
 768         t->insert = dn_fib_table_insert;
 769         t->delete = dn_fib_table_delete;
 770         t->lookup = dn_fib_table_lookup;
 771         t->flush  = dn_fib_table_flush;
 772         t->dump = dn_fib_table_dump;
 773         memset(t->data, 0, sizeof(struct dn_hash));
 774         dn_fib_tables[n] = t;
 775
 776         return t;
 777 }
 778
 779 static void dn_fib_del_tree(int n)
 780 {
 781         struct dn_fib_table *t;
 782
 783         write_lock(&dn_fib_tables_lock);
 784         t = dn_fib_tables[n];
 785         dn_fib_tables[n] = NULL;
 786         write_unlock(&dn_fib_tables_lock);
 787
 788         kfree(t);
 789 }
 790
 791 struct dn_fib_table *dn_fib_empty_table(void)
 792 {
 793         int id;
 794
 795         for(id = RT_TABLE_MIN; id <= RT_TABLE_MAX; id++)
 796                 if (dn_fib_tables[id] == NULL)
 797                         return dn_fib_get_table(id, 1);
 798         return NULL;
 799 }
 800
 801 void __init dn_fib_table_init(void)
 802 {
 803         dn_hash_kmem = kmem_cache_create("dn_fib_info_cache",
 804                                         sizeof(struct dn_fib_info),
 805                                         0, SLAB_HWCACHE_ALIGN,
 806                                         NULL, NULL);
 807 }
 808
 809 void __exit dn_fib_table_cleanup(void)
 810 {
 811         int i;
 812
 813         for (i = RT_TABLE_MIN; i <= RT_TABLE_MAX; ++i)
 814                 dn_fib_del_tree(i);
 815
 816         return;
 817 }