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 = kmalloc(new_divisor*sizeof(struct dn_fib_node*), GFP_KERNEL);
 162
 163         if (ht == NULL)
 164                 return;
 165
 166         memset(ht, 0, new_divisor*sizeof(struct dn_fib_node *));
 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 = kmalloc(sizeof(struct dn_zone), GFP_KERNEL);
 188         if (!dz)
 189                 return NULL;
 190
 191         memset(dz, 0, sizeof(struct dn_zone));
 192         if (z) {
 193                 dz->dz_divisor = 16;
 194                 dz->dz_hashmask = 0x0F;
 195         } else {
 196                 dz->dz_divisor = 1;
 197                 dz->dz_hashmask = 0;
 198         }
 199
 200         dz->dz_hash = kmalloc(dz->dz_divisor*sizeof(struct dn_fib_node *), GFP_KERNEL);
 201
 202         if (!dz->dz_hash) {
 203                 kfree(dz);
 204                 return NULL;
 205         }
 206
 207         memset(dz->dz_hash, 0, dz->dz_divisor*sizeof(struct dn_fib_node*));
 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 dn_kern_rta *rta, struct dn_fib_info *fi)
 230 {
 231         struct rtnexthop *nhp;
 232         int nhlen;
 233
 234         if (rta->rta_priority && *rta->rta_priority != fi->fib_priority)
 235                 return 1;
 236
 237         if (rta->rta_oif || rta->rta_gw) {
 238                 if ((!rta->rta_oif || *rta->rta_oif == fi->fib_nh->nh_oif) &&
 239                     (!rta->rta_gw  || memcmp(rta->rta_gw, &fi->fib_nh->nh_gw, 2) == 0))
 240                         return 0;
 241                 return 1;
 242         }
 243
 244         if (rta->rta_mp == NULL)
 245                 return 0;
 246
 247         nhp = RTA_DATA(rta->rta_mp);
 248         nhlen = RTA_PAYLOAD(rta->rta_mp);
 249
 250         for_nexthops(fi) {
 251                 int attrlen = nhlen - sizeof(struct rtnexthop);
 252                 __le16 gw;
 253
 254                 if (attrlen < 0 || (nhlen -= nhp->rtnh_len) < 0)
 255                         return -EINVAL;
 256                 if (nhp->rtnh_ifindex && nhp->rtnh_ifindex != nh->nh_oif)
 257                         return 1;
 258                 if (attrlen) {
 259                         gw = dn_fib_get_attr16(RTNH_DATA(nhp), attrlen, RTA_GATEWAY);
 260
 261                         if (gw && gw != nh->nh_gw)
 262                                 return 1;
 263                 }
 264                 nhp = RTNH_NEXT(nhp);
 265         } endfor_nexthops(fi);
 266
 267         return 0;
 268 }
 269
 270 static int dn_fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
 271                         u8 tb_id, u8 type, u8 scope, void *dst, int dst_len,
 272                         struct dn_fib_info *fi, unsigned int flags)
 273 {
 274         struct rtmsg *rtm;
 275         struct nlmsghdr *nlh;
 276         unsigned char *b = skb->tail;
 277
 278         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*rtm), flags);
 279         rtm = NLMSG_DATA(nlh);
 280         rtm->rtm_family = AF_DECnet;
 281         rtm->rtm_dst_len = dst_len;
 282         rtm->rtm_src_len = 0;
 283         rtm->rtm_tos = 0;
 284         rtm->rtm_table = tb_id;
 285         rtm->rtm_flags = fi->fib_flags;
 286         rtm->rtm_scope = scope;
 287         rtm->rtm_type  = type;
 288         if (rtm->rtm_dst_len)
 289                 RTA_PUT(skb, RTA_DST, 2, dst);
 290         rtm->rtm_protocol = fi->fib_protocol;
 291         if (fi->fib_priority)
 292                 RTA_PUT(skb, RTA_PRIORITY, 4, &fi->fib_priority);
 293         if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0)
 294                 goto rtattr_failure;
 295         if (fi->fib_nhs == 1) {
 296                 if (fi->fib_nh->nh_gw)
 297                         RTA_PUT(skb, RTA_GATEWAY, 2, &fi->fib_nh->nh_gw);
 298                 if (fi->fib_nh->nh_oif)
 299                         RTA_PUT(skb, RTA_OIF, sizeof(int), &fi->fib_nh->nh_oif);
 300         }
 301         if (fi->fib_nhs > 1) {
 302                 struct rtnexthop *nhp;
 303                 struct rtattr *mp_head;
 304                 if (skb_tailroom(skb) <= RTA_SPACE(0))
 305                         goto rtattr_failure;
 306                 mp_head = (struct rtattr *)skb_put(skb, RTA_SPACE(0));
 307
 308                 for_nexthops(fi) {
 309                         if (skb_tailroom(skb) < RTA_ALIGN(RTA_ALIGN(sizeof(*nhp)) + 4))
 310                                 goto rtattr_failure;
 311                         nhp = (struct rtnexthop *)skb_put(skb, RTA_ALIGN(sizeof(*nhp)));
 312                         nhp->rtnh_flags = nh->nh_flags & 0xFF;
 313                         nhp->rtnh_hops = nh->nh_weight - 1;
 314                         nhp->rtnh_ifindex = nh->nh_oif;
 315                         if (nh->nh_gw)
 316                                 RTA_PUT(skb, RTA_GATEWAY, 2, &nh->nh_gw);
 317                         nhp->rtnh_len = skb->tail - (unsigned char *)nhp;
 318                 } endfor_nexthops(fi);
 319                 mp_head->rta_type = RTA_MULTIPATH;
 320                 mp_head->rta_len = skb->tail - (u8*)mp_head;
 321         }
 322
 323         nlh->nlmsg_len = skb->tail - b;
 324         return skb->len;
 325
 326
 327 nlmsg_failure:
 328 rtattr_failure:
 329         skb_trim(skb, b - skb->data);
 330         return -1;
 331 }
 332
 333
 334 static void dn_rtmsg_fib(int event, struct dn_fib_node *f, int z, int tb_id,
 335                         struct nlmsghdr *nlh, struct netlink_skb_parms *req)
 336 {
 337         struct sk_buff *skb;
 338         u32 pid = req ? req->pid : 0;
 339         int size = NLMSG_SPACE(sizeof(struct rtmsg) + 256);
 340
 341         skb = alloc_skb(size, GFP_KERNEL);
 342         if (!skb)
 343                 return;
 344
 345         if (dn_fib_dump_info(skb, pid, nlh->nlmsg_seq, event, tb_id,
 346                                 f->fn_type, f->fn_scope, &f->fn_key, z,
 347                                 DN_FIB_INFO(f), 0) < 0) {
 348                 kfree_skb(skb);
 349                 return;
 350         }
 351         NETLINK_CB(skb).dst_group = RTNLGRP_DECnet_ROUTE;
 352         if (nlh->nlmsg_flags & NLM_F_ECHO)
 353                 atomic_inc(&skb->users);
 354         netlink_broadcast(rtnl, skb, pid, RTNLGRP_DECnet_ROUTE, GFP_KERNEL);
 355         if (nlh->nlmsg_flags & NLM_F_ECHO)
 356                 netlink_unicast(rtnl, skb, pid, MSG_DONTWAIT);
 357 }
 358
 359 static __inline__ int dn_hash_dump_bucket(struct sk_buff *skb,
 360                                 struct netlink_callback *cb,
 361                                 struct dn_fib_table *tb,
 362                                 struct dn_zone *dz,
 363                                 struct dn_fib_node *f)
 364 {
 365         int i, s_i;
 366
 367         s_i = cb->args[3];
 368         for(i = 0; f; i++, f = f->fn_next) {
 369                 if (i < s_i)
 370                         continue;
 371                 if (f->fn_state & DN_S_ZOMBIE)
 372                         continue;
 373                 if (dn_fib_dump_info(skb, NETLINK_CB(cb->skb).pid,
 374                                 cb->nlh->nlmsg_seq,
 375                                 RTM_NEWROUTE,
 376                                 tb->n,
 377                                 (f->fn_state & DN_S_ZOMBIE) ? 0 : f->fn_type,
 378                                 f->fn_scope, &f->fn_key, dz->dz_order,
 379                                 f->fn_info, NLM_F_MULTI) < 0) {
 380                         cb->args[3] = i;
 381                         return -1;
 382                 }
 383         }
 384         cb->args[3] = i;
 385         return skb->len;
 386 }
 387
 388 static __inline__ int dn_hash_dump_zone(struct sk_buff *skb,
 389                                 struct netlink_callback *cb,
 390                                 struct dn_fib_table *tb,
 391                                 struct dn_zone *dz)
 392 {
 393         int h, s_h;
 394
 395         s_h = cb->args[2];
 396         for(h = 0; h < dz->dz_divisor; h++) {
 397                 if (h < s_h)
 398                         continue;
 399                 if (h > s_h)
 400                         memset(&cb->args[3], 0, sizeof(cb->args) - 3*sizeof(cb->args[0]));
 401                 if (dz->dz_hash == NULL || dz->dz_hash[h] == NULL)
 402                         continue;
 403                 if (dn_hash_dump_bucket(skb, cb, tb, dz, dz->dz_hash[h]) < 0) {
 404                         cb->args[2] = h;
 405                         return -1;
 406                 }
 407         }
 408         cb->args[2] = h;
 409         return skb->len;
 410 }
 411
 412 static int dn_fib_table_dump(struct dn_fib_table *tb, struct sk_buff *skb,
 413                                 struct netlink_callback *cb)
 414 {
 415         int m, s_m;
 416         struct dn_zone *dz;
 417         struct dn_hash *table = (struct dn_hash *)tb->data;
 418
 419         s_m = cb->args[1];
 420         read_lock(&dn_fib_tables_lock);
 421         for(dz = table->dh_zone_list, m = 0; dz; dz = dz->dz_next, m++) {
 422                 if (m < s_m)
 423                         continue;
 424                 if (m > s_m)
 425                         memset(&cb->args[2], 0, sizeof(cb->args) - 2*sizeof(cb->args[0]));
 426
 427                 if (dn_hash_dump_zone(skb, cb, tb, dz) < 0) {
 428                         cb->args[1] = m;
 429                         read_unlock(&dn_fib_tables_lock);
 430                         return -1;
 431                 }
 432         }
 433         read_unlock(&dn_fib_tables_lock);
 434         cb->args[1] = m;
 435
 436         return skb->len;
 437 }
 438
 439 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)
 440 {
 441         struct dn_hash *table = (struct dn_hash *)tb->data;
 442         struct dn_fib_node *new_f, *f, **fp, **del_fp;
 443         struct dn_zone *dz;
 444         struct dn_fib_info *fi;
 445         int z = r->rtm_dst_len;
 446         int type = r->rtm_type;
 447         dn_fib_key_t key;
 448         int err;
 449
 450         if (z > 16)
 451                 return -EINVAL;
 452
 453         dz = table->dh_zones[z];
 454         if (!dz && !(dz = dn_new_zone(table, z)))
 455                 return -ENOBUFS;
 456
 457         dz_key_0(key);
 458         if (rta->rta_dst) {
 459                 __le16 dst;
 460                 memcpy(&dst, rta->rta_dst, 2);
 461                 if (dst & ~DZ_MASK(dz))
 462                         return -EINVAL;
 463                 key = dz_key(dst, dz);
 464         }
 465
 466         if ((fi = dn_fib_create_info(r, rta, n, &err)) == NULL)
 467                 return err;
 468
 469         if (dz->dz_nent > (dz->dz_divisor << 2) &&
 470                         dz->dz_divisor > DN_MAX_DIVISOR &&
 471                         (z==16 || (1<<z) > dz->dz_divisor))
 472                 dn_rehash_zone(dz);
 473
 474         fp = dn_chain_p(key, dz);
 475
 476         DN_FIB_SCAN(f, fp) {
 477                 if (dn_key_leq(key, f->fn_key))
 478                         break;
 479         }
 480
 481         del_fp = NULL;
 482
 483         if (f && (f->fn_state & DN_S_ZOMBIE) &&
 484                         dn_key_eq(f->fn_key, key)) {
 485                 del_fp = fp;
 486                 fp = &f->fn_next;
 487                 f = *fp;
 488                 goto create;
 489         }
 490
 491         DN_FIB_SCAN_KEY(f, fp, key) {
 492                 if (fi->fib_priority <= DN_FIB_INFO(f)->fib_priority)
 493                         break;
 494         }
 495
 496         if (f && dn_key_eq(f->fn_key, key) &&
 497                         fi->fib_priority == DN_FIB_INFO(f)->fib_priority) {
 498                 struct dn_fib_node **ins_fp;
 499
 500                 err = -EEXIST;
 501                 if (n->nlmsg_flags & NLM_F_EXCL)
 502                         goto out;
 503
 504                 if (n->nlmsg_flags & NLM_F_REPLACE) {
 505                         del_fp = fp;
 506                         fp = &f->fn_next;
 507                         f = *fp;
 508                         goto replace;
 509                 }
 510
 511                 ins_fp = fp;
 512                 err = -EEXIST;
 513
 514                 DN_FIB_SCAN_KEY(f, fp, key) {
 515                         if (fi->fib_priority != DN_FIB_INFO(f)->fib_priority)
 516                                 break;
 517                         if (f->fn_type == type && f->fn_scope == r->rtm_scope
 518                                         && DN_FIB_INFO(f) == fi)
 519                                 goto out;
 520                 }
 521
 522                 if (!(n->nlmsg_flags & NLM_F_APPEND)) {
 523                         fp = ins_fp;
 524                         f = *fp;
 525                 }
 526         }
 527
 528 create:
 529         err = -ENOENT;
 530         if (!(n->nlmsg_flags & NLM_F_CREATE))
 531                 goto out;
 532
 533 replace:
 534         err = -ENOBUFS;
 535         new_f = kmem_cache_alloc(dn_hash_kmem, SLAB_KERNEL);
 536         if (new_f == NULL)
 537                 goto out;
 538
 539         memset(new_f, 0, sizeof(struct dn_fib_node));
 540
 541         new_f->fn_key = key;
 542         new_f->fn_type = type;
 543         new_f->fn_scope = r->rtm_scope;
 544         DN_FIB_INFO(new_f) = fi;
 545
 546         new_f->fn_next = f;
 547         write_lock_bh(&dn_fib_tables_lock);
 548         *fp = new_f;
 549         write_unlock_bh(&dn_fib_tables_lock);
 550         dz->dz_nent++;
 551
 552         if (del_fp) {
 553                 f = *del_fp;
 554                 write_lock_bh(&dn_fib_tables_lock);
 555                 *del_fp = f->fn_next;
 556                 write_unlock_bh(&dn_fib_tables_lock);
 557
 558                 if (!(f->fn_state & DN_S_ZOMBIE))
 559                         dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 560                 if (f->fn_state & DN_S_ACCESSED)
 561                         dn_rt_cache_flush(-1);
 562                 dn_free_node(f);
 563                 dz->dz_nent--;
 564         } else {
 565                 dn_rt_cache_flush(-1);
 566         }
 567
 568         dn_rtmsg_fib(RTM_NEWROUTE, new_f, z, tb->n, n, req);
 569
 570         return 0;
 571 out:
 572         dn_fib_release_info(fi);
 573         return err;
 574 }
 575
 576
 577 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)
 578 {
 579         struct dn_hash *table = (struct dn_hash*)tb->data;
 580         struct dn_fib_node **fp, **del_fp, *f;
 581         int z = r->rtm_dst_len;
 582         struct dn_zone *dz;
 583         dn_fib_key_t key;
 584         int matched;
 585
 586
 587         if (z > 16)
 588                 return -EINVAL;
 589
 590         if ((dz = table->dh_zones[z]) == NULL)
 591                 return -ESRCH;
 592
 593         dz_key_0(key);
 594         if (rta->rta_dst) {
 595                 __le16 dst;
 596                 memcpy(&dst, rta->rta_dst, 2);
 597                 if (dst & ~DZ_MASK(dz))
 598                         return -EINVAL;
 599                 key = dz_key(dst, dz);
 600         }
 601
 602         fp = dn_chain_p(key, dz);
 603
 604         DN_FIB_SCAN(f, fp) {
 605                 if (dn_key_eq(f->fn_key, key))
 606                         break;
 607                 if (dn_key_leq(key, f->fn_key))
 608                         return -ESRCH;
 609         }
 610
 611         matched = 0;
 612         del_fp = NULL;
 613         DN_FIB_SCAN_KEY(f, fp, key) {
 614                 struct dn_fib_info *fi = DN_FIB_INFO(f);
 615
 616                 if (f->fn_state & DN_S_ZOMBIE)
 617                         return -ESRCH;
 618
 619                 matched++;
 620
 621                 if (del_fp == NULL &&
 622                                 (!r->rtm_type || f->fn_type == r->rtm_type) &&
 623                                 (r->rtm_scope == RT_SCOPE_NOWHERE || f->fn_scope == r->rtm_scope) &&
 624                                 (!r->rtm_protocol ||
 625                                         fi->fib_protocol == r->rtm_protocol) &&
 626                                 dn_fib_nh_match(r, n, rta, fi) == 0)
 627                         del_fp = fp;
 628         }
 629
 630         if (del_fp) {
 631                 f = *del_fp;
 632                 dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 633
 634                 if (matched != 1) {
 635                         write_lock_bh(&dn_fib_tables_lock);
 636                         *del_fp = f->fn_next;
 637                         write_unlock_bh(&dn_fib_tables_lock);
 638
 639                         if (f->fn_state & DN_S_ACCESSED)
 640                                 dn_rt_cache_flush(-1);
 641                         dn_free_node(f);
 642                         dz->dz_nent--;
 643                 } else {
 644                         f->fn_state |= DN_S_ZOMBIE;
 645                         if (f->fn_state & DN_S_ACCESSED) {
 646                                 f->fn_state &= ~DN_S_ACCESSED;
 647                                 dn_rt_cache_flush(-1);
 648                         }
 649                         if (++dn_fib_hash_zombies > 128)
 650                                 dn_fib_flush();
 651                 }
 652
 653                 return 0;
 654         }
 655
 656         return -ESRCH;
 657 }
 658
 659 static inline int dn_flush_list(struct dn_fib_node **fp, int z, struct dn_hash *table)
 660 {
 661         int found = 0;
 662         struct dn_fib_node *f;
 663
 664         while((f = *fp) != NULL) {
 665                 struct dn_fib_info *fi = DN_FIB_INFO(f);
 666
 667                 if (fi && ((f->fn_state & DN_S_ZOMBIE) || (fi->fib_flags & RTNH_F_DEAD))) {
 668                         write_lock_bh(&dn_fib_tables_lock);
 669                         *fp = f->fn_next;
 670                         write_unlock_bh(&dn_fib_tables_lock);
 671
 672                         dn_free_node(f);
 673                         found++;
 674                         continue;
 675                 }
 676                 fp = &f->fn_next;
 677         }
 678
 679         return found;
 680 }
 681
 682 static int dn_fib_table_flush(struct dn_fib_table *tb)
 683 {
 684         struct dn_hash *table = (struct dn_hash *)tb->data;
 685         struct dn_zone *dz;
 686         int found = 0;
 687
 688         dn_fib_hash_zombies = 0;
 689         for(dz = table->dh_zone_list; dz; dz = dz->dz_next) {
 690                 int i;
 691                 int tmp = 0;
 692                 for(i = dz->dz_divisor-1; i >= 0; i--)
 693                         tmp += dn_flush_list(&dz->dz_hash[i], dz->dz_order, table);
 694                 dz->dz_nent -= tmp;
 695                 found += tmp;
 696         }
 697
 698         return found;
 699 }
 700
 701 static int dn_fib_table_lookup(struct dn_fib_table *tb, const struct flowi *flp, struct dn_fib_res *res)
 702 {
 703         int err;
 704         struct dn_zone *dz;
 705         struct dn_hash *t = (struct dn_hash *)tb->data;
 706
 707         read_lock(&dn_fib_tables_lock);
 708         for(dz = t->dh_zone_list; dz; dz = dz->dz_next) {
 709                 struct dn_fib_node *f;
 710                 dn_fib_key_t k = dz_key(flp->fld_dst, dz);
 711
 712                 for(f = dz_chain(k, dz); f; f = f->fn_next) {
 713                         if (!dn_key_eq(k, f->fn_key)) {
 714                                 if (dn_key_leq(k, f->fn_key))
 715                                         break;
 716                                 else
 717                                         continue;
 718                         }
 719
 720                         f->fn_state |= DN_S_ACCESSED;
 721
 722                         if (f->fn_state&DN_S_ZOMBIE)
 723                                 continue;
 724
 725                         if (f->fn_scope < flp->fld_scope)
 726                                 continue;
 727
 728                         err = dn_fib_semantic_match(f->fn_type, DN_FIB_INFO(f), flp, res);
 729
 730                         if (err == 0) {
 731                                 res->type = f->fn_type;
 732                                 res->scope = f->fn_scope;
 733                                 res->prefixlen = dz->dz_order;
 734                                 goto out;
 735                         }
 736                         if (err < 0)
 737                                 goto out;
 738                 }
 739         }
 740         err = 1;
 741 out:
 742         read_unlock(&dn_fib_tables_lock);
 743         return err;
 744 }
 745
 746
 747 struct dn_fib_table *dn_fib_get_table(int n, int create)
 748 {
 749         struct dn_fib_table *t;
 750
 751         if (n < RT_TABLE_MIN)
 752                 return NULL;
 753
 754         if (n > RT_TABLE_MAX)
 755                 return NULL;
 756
 757         if (dn_fib_tables[n])
 758                 return dn_fib_tables[n];
 759
 760         if (!create)
 761                 return NULL;
 762
 763         if (in_interrupt() && net_ratelimit()) {
 764                 printk(KERN_DEBUG "DECnet: BUG! Attempt to create routing table from interrupt\n");
 765                 return NULL;
 766         }
 767         if ((t = kmalloc(sizeof(struct dn_fib_table) + sizeof(struct dn_hash), GFP_KERNEL)) == NULL)
 768                 return NULL;
 769
 770         memset(t, 0, sizeof(struct dn_fib_table));
 771
 772         t->n = n;
 773         t->insert = dn_fib_table_insert;
 774         t->delete = dn_fib_table_delete;
 775         t->lookup = dn_fib_table_lookup;
 776         t->flush  = dn_fib_table_flush;
 777         t->dump = dn_fib_table_dump;
 778         memset(t->data, 0, sizeof(struct dn_hash));
 779         dn_fib_tables[n] = t;
 780
 781         return t;
 782 }
 783
 784 static void dn_fib_del_tree(int n)
 785 {
 786         struct dn_fib_table *t;
 787
 788         write_lock(&dn_fib_tables_lock);
 789         t = dn_fib_tables[n];
 790         dn_fib_tables[n] = NULL;
 791         write_unlock(&dn_fib_tables_lock);
 792
 793         kfree(t);
 794 }
 795
 796 struct dn_fib_table *dn_fib_empty_table(void)
 797 {
 798         int id;
 799
 800         for(id = RT_TABLE_MIN; id <= RT_TABLE_MAX; id++)
 801                 if (dn_fib_tables[id] == NULL)
 802                         return dn_fib_get_table(id, 1);
 803         return NULL;
 804 }
 805
 806 void __init dn_fib_table_init(void)
 807 {
 808         dn_hash_kmem = kmem_cache_create("dn_fib_info_cache",
 809                                         sizeof(struct dn_fib_info),
 810                                         0, SLAB_HWCACHE_ALIGN,
 811                                         NULL, NULL);
 812 }
 813
 814 void __exit dn_fib_table_cleanup(void)
 815 {
 816         int i;
 817
 818         for (i = RT_TABLE_MIN; i <= RT_TABLE_MAX; ++i)
 819                 dn_fib_del_tree(i);
 820
 821         return;
 822 }