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