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   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/fib_rules.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         __le16                  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 DEFINE_RWLOCK(dn_fib_tables_lock);
  80 struct dn_fib_table *dn_fib_tables[RT_TABLE_MAX + 1];
  81
  82 static kmem_cache_t *dn_hash_kmem __read_mostly;
  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 = dn_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(__le16 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 = kcalloc(new_divisor, sizeof(struct dn_fib_node*), GFP_KERNEL);
 163         if (ht == NULL)
 164                 return;
 165
 166         write_lock_bh(&dn_fib_tables_lock);
 167         old_ht = dz->dz_hash;
 168         dz->dz_hash = ht;
 169         dz->dz_hashmask = new_hashmask;
 170         dz->dz_divisor = new_divisor;
 171         dn_rebuild_zone(dz, old_ht, old_divisor);
 172         write_unlock_bh(&dn_fib_tables_lock);
 173         kfree(old_ht);
 174 }
 175
 176 static void dn_free_node(struct dn_fib_node *f)
 177 {
 178         dn_fib_release_info(DN_FIB_INFO(f));
 179         kmem_cache_free(dn_hash_kmem, f);
 180 }
 181
 182
 183 static struct dn_zone *dn_new_zone(struct dn_hash *table, int z)
 184 {
 185         int i;
 186         struct dn_zone *dz = kzalloc(sizeof(struct dn_zone), GFP_KERNEL);
 187         if (!dz)
 188                 return NULL;
 189
 190         if (z) {
 191                 dz->dz_divisor = 16;
 192                 dz->dz_hashmask = 0x0F;
 193         } else {
 194                 dz->dz_divisor = 1;
 195                 dz->dz_hashmask = 0;
 196         }
 197
 198         dz->dz_hash = kcalloc(dz->dz_divisor, sizeof(struct dn_fib_node *), GFP_KERNEL);
 199         if (!dz->dz_hash) {
 200                 kfree(dz);
 201                 return NULL;
 202         }
 203
 204         dz->dz_order = z;
 205         dz->dz_mask = dnet_make_mask(z);
 206
 207         for(i = z + 1; i <= 16; i++)
 208                 if (table->dh_zones[i])
 209                         break;
 210
 211         write_lock_bh(&dn_fib_tables_lock);
 212         if (i>16) {
 213                 dz->dz_next = table->dh_zone_list;
 214                 table->dh_zone_list = dz;
 215         } else {
 216                 dz->dz_next = table->dh_zones[i]->dz_next;
 217                 table->dh_zones[i]->dz_next = dz;
 218         }
 219         table->dh_zones[z] = dz;
 220         write_unlock_bh(&dn_fib_tables_lock);
 221         return dz;
 222 }
 223
 224
 225 static int dn_fib_nh_match(struct rtmsg *r, struct nlmsghdr *nlh, struct dn_kern_rta *rta, struct dn_fib_info *fi)
 226 {
 227         struct rtnexthop *nhp;
 228         int nhlen;
 229
 230         if (rta->rta_priority && *rta->rta_priority != fi->fib_priority)
 231                 return 1;
 232
 233         if (rta->rta_oif || rta->rta_gw) {
 234                 if ((!rta->rta_oif || *rta->rta_oif == fi->fib_nh->nh_oif) &&
 235                     (!rta->rta_gw  || memcmp(rta->rta_gw, &fi->fib_nh->nh_gw, 2) == 0))
 236                         return 0;
 237                 return 1;
 238         }
 239
 240         if (rta->rta_mp == NULL)
 241                 return 0;
 242
 243         nhp = RTA_DATA(rta->rta_mp);
 244         nhlen = RTA_PAYLOAD(rta->rta_mp);
 245
 246         for_nexthops(fi) {
 247                 int attrlen = nhlen - sizeof(struct rtnexthop);
 248                 __le16 gw;
 249
 250                 if (attrlen < 0 || (nhlen -= nhp->rtnh_len) < 0)
 251                         return -EINVAL;
 252                 if (nhp->rtnh_ifindex && nhp->rtnh_ifindex != nh->nh_oif)
 253                         return 1;
 254                 if (attrlen) {
 255                         gw = dn_fib_get_attr16(RTNH_DATA(nhp), attrlen, RTA_GATEWAY);
 256
 257                         if (gw && gw != nh->nh_gw)
 258                                 return 1;
 259                 }
 260                 nhp = RTNH_NEXT(nhp);
 261         } endfor_nexthops(fi);
 262
 263         return 0;
 264 }
 265
 266 static int dn_fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
 267                         u32 tb_id, u8 type, u8 scope, void *dst, int dst_len,
 268                         struct dn_fib_info *fi, unsigned int flags)
 269 {
 270         struct rtmsg *rtm;
 271         struct nlmsghdr *nlh;
 272         unsigned char *b = skb->tail;
 273
 274         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*rtm), flags);
 275         rtm = NLMSG_DATA(nlh);
 276         rtm->rtm_family = AF_DECnet;
 277         rtm->rtm_dst_len = dst_len;
 278         rtm->rtm_src_len = 0;
 279         rtm->rtm_tos = 0;
 280         rtm->rtm_table = tb_id;
 281         rtm->rtm_flags = fi->fib_flags;
 282         rtm->rtm_scope = scope;
 283         rtm->rtm_type  = type;
 284         if (rtm->rtm_dst_len)
 285                 RTA_PUT(skb, RTA_DST, 2, dst);
 286         rtm->rtm_protocol = fi->fib_protocol;
 287         if (fi->fib_priority)
 288                 RTA_PUT(skb, RTA_PRIORITY, 4, &fi->fib_priority);
 289         if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0)
 290                 goto rtattr_failure;
 291         if (fi->fib_nhs == 1) {
 292                 if (fi->fib_nh->nh_gw)
 293                         RTA_PUT(skb, RTA_GATEWAY, 2, &fi->fib_nh->nh_gw);
 294                 if (fi->fib_nh->nh_oif)
 295                         RTA_PUT(skb, RTA_OIF, sizeof(int), &fi->fib_nh->nh_oif);
 296         }
 297         if (fi->fib_nhs > 1) {
 298                 struct rtnexthop *nhp;
 299                 struct rtattr *mp_head;
 300                 if (skb_tailroom(skb) <= RTA_SPACE(0))
 301                         goto rtattr_failure;
 302                 mp_head = (struct rtattr *)skb_put(skb, RTA_SPACE(0));
 303
 304                 for_nexthops(fi) {
 305                         if (skb_tailroom(skb) < RTA_ALIGN(RTA_ALIGN(sizeof(*nhp)) + 4))
 306                                 goto rtattr_failure;
 307                         nhp = (struct rtnexthop *)skb_put(skb, RTA_ALIGN(sizeof(*nhp)));
 308                         nhp->rtnh_flags = nh->nh_flags & 0xFF;
 309                         nhp->rtnh_hops = nh->nh_weight - 1;
 310                         nhp->rtnh_ifindex = nh->nh_oif;
 311                         if (nh->nh_gw)
 312                                 RTA_PUT(skb, RTA_GATEWAY, 2, &nh->nh_gw);
 313                         nhp->rtnh_len = skb->tail - (unsigned char *)nhp;
 314                 } endfor_nexthops(fi);
 315                 mp_head->rta_type = RTA_MULTIPATH;
 316                 mp_head->rta_len = skb->tail - (u8*)mp_head;
 317         }
 318
 319         nlh->nlmsg_len = skb->tail - b;
 320         return skb->len;
 321
 322
 323 nlmsg_failure:
 324 rtattr_failure:
 325         skb_trim(skb, b - skb->data);
 326         return -1;
 327 }
 328
 329
 330 static void dn_rtmsg_fib(int event, struct dn_fib_node *f, int z, u32 tb_id,
 331                         struct nlmsghdr *nlh, struct netlink_skb_parms *req)
 332 {
 333         struct sk_buff *skb;
 334         u32 pid = req ? req->pid : 0;
 335         int size = NLMSG_SPACE(sizeof(struct rtmsg) + 256);
 336
 337         skb = alloc_skb(size, GFP_KERNEL);
 338         if (!skb)
 339                 return;
 340
 341         if (dn_fib_dump_info(skb, pid, nlh->nlmsg_seq, event, tb_id,
 342                                 f->fn_type, f->fn_scope, &f->fn_key, z,
 343                                 DN_FIB_INFO(f), 0) < 0) {
 344                 kfree_skb(skb);
 345                 return;
 346         }
 347         NETLINK_CB(skb).dst_group = RTNLGRP_DECnet_ROUTE;
 348         if (nlh->nlmsg_flags & NLM_F_ECHO)
 349                 atomic_inc(&skb->users);
 350         netlink_broadcast(rtnl, skb, pid, RTNLGRP_DECnet_ROUTE, GFP_KERNEL);
 351         if (nlh->nlmsg_flags & NLM_F_ECHO)
 352                 netlink_unicast(rtnl, skb, pid, MSG_DONTWAIT);
 353 }
 354
 355 static __inline__ int dn_hash_dump_bucket(struct sk_buff *skb,
 356                                 struct netlink_callback *cb,
 357                                 struct dn_fib_table *tb,
 358                                 struct dn_zone *dz,
 359                                 struct dn_fib_node *f)
 360 {
 361         int i, s_i;
 362
 363         s_i = cb->args[3];
 364         for(i = 0; f; i++, f = f->fn_next) {
 365                 if (i < s_i)
 366                         continue;
 367                 if (f->fn_state & DN_S_ZOMBIE)
 368                         continue;
 369                 if (dn_fib_dump_info(skb, NETLINK_CB(cb->skb).pid,
 370                                 cb->nlh->nlmsg_seq,
 371                                 RTM_NEWROUTE,
 372                                 tb->n,
 373                                 (f->fn_state & DN_S_ZOMBIE) ? 0 : f->fn_type,
 374                                 f->fn_scope, &f->fn_key, dz->dz_order,
 375                                 f->fn_info, NLM_F_MULTI) < 0) {
 376                         cb->args[3] = i;
 377                         return -1;
 378                 }
 379         }
 380         cb->args[3] = i;
 381         return skb->len;
 382 }
 383
 384 static __inline__ int dn_hash_dump_zone(struct sk_buff *skb,
 385                                 struct netlink_callback *cb,
 386                                 struct dn_fib_table *tb,
 387                                 struct dn_zone *dz)
 388 {
 389         int h, s_h;
 390
 391         s_h = cb->args[2];
 392         for(h = 0; h < dz->dz_divisor; h++) {
 393                 if (h < s_h)
 394                         continue;
 395                 if (h > s_h)
 396                         memset(&cb->args[3], 0, sizeof(cb->args) - 3*sizeof(cb->args[0]));
 397                 if (dz->dz_hash == NULL || dz->dz_hash[h] == NULL)
 398                         continue;
 399                 if (dn_hash_dump_bucket(skb, cb, tb, dz, dz->dz_hash[h]) < 0) {
 400                         cb->args[2] = h;
 401                         return -1;
 402                 }
 403         }
 404         cb->args[2] = h;
 405         return skb->len;
 406 }
 407
 408 static int dn_fib_table_dump(struct dn_fib_table *tb, struct sk_buff *skb,
 409                                 struct netlink_callback *cb)
 410 {
 411         int m, s_m;
 412         struct dn_zone *dz;
 413         struct dn_hash *table = (struct dn_hash *)tb->data;
 414
 415         s_m = cb->args[1];
 416         read_lock(&dn_fib_tables_lock);
 417         for(dz = table->dh_zone_list, m = 0; dz; dz = dz->dz_next, m++) {
 418                 if (m < s_m)
 419                         continue;
 420                 if (m > s_m)
 421                         memset(&cb->args[2], 0, sizeof(cb->args) - 2*sizeof(cb->args[0]));
 422
 423                 if (dn_hash_dump_zone(skb, cb, tb, dz) < 0) {
 424                         cb->args[1] = m;
 425                         read_unlock(&dn_fib_tables_lock);
 426                         return -1;
 427                 }
 428         }
 429         read_unlock(&dn_fib_tables_lock);
 430         cb->args[1] = m;
 431
 432         return skb->len;
 433 }
 434
 435 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)
 436 {
 437         struct dn_hash *table = (struct dn_hash *)tb->data;
 438         struct dn_fib_node *new_f, *f, **fp, **del_fp;
 439         struct dn_zone *dz;
 440         struct dn_fib_info *fi;
 441         int z = r->rtm_dst_len;
 442         int type = r->rtm_type;
 443         dn_fib_key_t key;
 444         int err;
 445
 446         if (z > 16)
 447                 return -EINVAL;
 448
 449         dz = table->dh_zones[z];
 450         if (!dz && !(dz = dn_new_zone(table, z)))
 451                 return -ENOBUFS;
 452
 453         dz_key_0(key);
 454         if (rta->rta_dst) {
 455                 __le16 dst;
 456                 memcpy(&dst, rta->rta_dst, 2);
 457                 if (dst & ~DZ_MASK(dz))
 458                         return -EINVAL;
 459                 key = dz_key(dst, dz);
 460         }
 461
 462         if ((fi = dn_fib_create_info(r, rta, n, &err)) == NULL)
 463                 return err;
 464
 465         if (dz->dz_nent > (dz->dz_divisor << 2) &&
 466                         dz->dz_divisor > DN_MAX_DIVISOR &&
 467                         (z==16 || (1<<z) > dz->dz_divisor))
 468                 dn_rehash_zone(dz);
 469
 470         fp = dn_chain_p(key, dz);
 471
 472         DN_FIB_SCAN(f, fp) {
 473                 if (dn_key_leq(key, f->fn_key))
 474                         break;
 475         }
 476
 477         del_fp = NULL;
 478
 479         if (f && (f->fn_state & DN_S_ZOMBIE) &&
 480                         dn_key_eq(f->fn_key, key)) {
 481                 del_fp = fp;
 482                 fp = &f->fn_next;
 483                 f = *fp;
 484                 goto create;
 485         }
 486
 487         DN_FIB_SCAN_KEY(f, fp, key) {
 488                 if (fi->fib_priority <= DN_FIB_INFO(f)->fib_priority)
 489                         break;
 490         }
 491
 492         if (f && dn_key_eq(f->fn_key, key) &&
 493                         fi->fib_priority == DN_FIB_INFO(f)->fib_priority) {
 494                 struct dn_fib_node **ins_fp;
 495
 496                 err = -EEXIST;
 497                 if (n->nlmsg_flags & NLM_F_EXCL)
 498                         goto out;
 499
 500                 if (n->nlmsg_flags & NLM_F_REPLACE) {
 501                         del_fp = fp;
 502                         fp = &f->fn_next;
 503                         f = *fp;
 504                         goto replace;
 505                 }
 506
 507                 ins_fp = fp;
 508                 err = -EEXIST;
 509
 510                 DN_FIB_SCAN_KEY(f, fp, key) {
 511                         if (fi->fib_priority != DN_FIB_INFO(f)->fib_priority)
 512                                 break;
 513                         if (f->fn_type == type && f->fn_scope == r->rtm_scope
 514                                         && DN_FIB_INFO(f) == fi)
 515                                 goto out;
 516                 }
 517
 518                 if (!(n->nlmsg_flags & NLM_F_APPEND)) {
 519                         fp = ins_fp;
 520                         f = *fp;
 521                 }
 522         }
 523
 524 create:
 525         err = -ENOENT;
 526         if (!(n->nlmsg_flags & NLM_F_CREATE))
 527                 goto out;
 528
 529 replace:
 530         err = -ENOBUFS;
 531         new_f = kmem_cache_alloc(dn_hash_kmem, SLAB_KERNEL);
 532         if (new_f == NULL)
 533                 goto out;
 534
 535         memset(new_f, 0, sizeof(struct dn_fib_node));
 536
 537         new_f->fn_key = key;
 538         new_f->fn_type = type;
 539         new_f->fn_scope = r->rtm_scope;
 540         DN_FIB_INFO(new_f) = fi;
 541
 542         new_f->fn_next = f;
 543         write_lock_bh(&dn_fib_tables_lock);
 544         *fp = new_f;
 545         write_unlock_bh(&dn_fib_tables_lock);
 546         dz->dz_nent++;
 547
 548         if (del_fp) {
 549                 f = *del_fp;
 550                 write_lock_bh(&dn_fib_tables_lock);
 551                 *del_fp = f->fn_next;
 552                 write_unlock_bh(&dn_fib_tables_lock);
 553
 554                 if (!(f->fn_state & DN_S_ZOMBIE))
 555                         dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 556                 if (f->fn_state & DN_S_ACCESSED)
 557                         dn_rt_cache_flush(-1);
 558                 dn_free_node(f);
 559                 dz->dz_nent--;
 560         } else {
 561                 dn_rt_cache_flush(-1);
 562         }
 563
 564         dn_rtmsg_fib(RTM_NEWROUTE, new_f, z, tb->n, n, req);
 565
 566         return 0;
 567 out:
 568         dn_fib_release_info(fi);
 569         return err;
 570 }
 571
 572
 573 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)
 574 {
 575         struct dn_hash *table = (struct dn_hash*)tb->data;
 576         struct dn_fib_node **fp, **del_fp, *f;
 577         int z = r->rtm_dst_len;
 578         struct dn_zone *dz;
 579         dn_fib_key_t key;
 580         int matched;
 581
 582
 583         if (z > 16)
 584                 return -EINVAL;
 585
 586         if ((dz = table->dh_zones[z]) == NULL)
 587                 return -ESRCH;
 588
 589         dz_key_0(key);
 590         if (rta->rta_dst) {
 591                 __le16 dst;
 592                 memcpy(&dst, rta->rta_dst, 2);
 593                 if (dst & ~DZ_MASK(dz))
 594                         return -EINVAL;
 595                 key = dz_key(dst, dz);
 596         }
 597
 598         fp = dn_chain_p(key, dz);
 599
 600         DN_FIB_SCAN(f, fp) {
 601                 if (dn_key_eq(f->fn_key, key))
 602                         break;
 603                 if (dn_key_leq(key, f->fn_key))
 604                         return -ESRCH;
 605         }
 606
 607         matched = 0;
 608         del_fp = NULL;
 609         DN_FIB_SCAN_KEY(f, fp, key) {
 610                 struct dn_fib_info *fi = DN_FIB_INFO(f);
 611
 612                 if (f->fn_state & DN_S_ZOMBIE)
 613                         return -ESRCH;
 614
 615                 matched++;
 616
 617                 if (del_fp == NULL &&
 618                                 (!r->rtm_type || f->fn_type == r->rtm_type) &&
 619                                 (r->rtm_scope == RT_SCOPE_NOWHERE || f->fn_scope == r->rtm_scope) &&
 620                                 (!r->rtm_protocol ||
 621                                         fi->fib_protocol == r->rtm_protocol) &&
 622                                 dn_fib_nh_match(r, n, rta, fi) == 0)
 623                         del_fp = fp;
 624         }
 625
 626         if (del_fp) {
 627                 f = *del_fp;
 628                 dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 629
 630                 if (matched != 1) {
 631                         write_lock_bh(&dn_fib_tables_lock);
 632                         *del_fp = f->fn_next;
 633                         write_unlock_bh(&dn_fib_tables_lock);
 634
 635                         if (f->fn_state & DN_S_ACCESSED)
 636                                 dn_rt_cache_flush(-1);
 637                         dn_free_node(f);
 638                         dz->dz_nent--;
 639                 } else {
 640                         f->fn_state |= DN_S_ZOMBIE;
 641                         if (f->fn_state & DN_S_ACCESSED) {
 642                                 f->fn_state &= ~DN_S_ACCESSED;
 643                                 dn_rt_cache_flush(-1);
 644                         }
 645                         if (++dn_fib_hash_zombies > 128)
 646                                 dn_fib_flush();
 647                 }
 648
 649                 return 0;
 650         }
 651
 652         return -ESRCH;
 653 }
 654
 655 static inline int dn_flush_list(struct dn_fib_node **fp, int z, struct dn_hash *table)
 656 {
 657         int found = 0;
 658         struct dn_fib_node *f;
 659
 660         while((f = *fp) != NULL) {
 661                 struct dn_fib_info *fi = DN_FIB_INFO(f);
 662
 663                 if (fi && ((f->fn_state & DN_S_ZOMBIE) || (fi->fib_flags & RTNH_F_DEAD))) {
 664                         write_lock_bh(&dn_fib_tables_lock);
 665                         *fp = f->fn_next;
 666                         write_unlock_bh(&dn_fib_tables_lock);
 667
 668                         dn_free_node(f);
 669                         found++;
 670                         continue;
 671                 }
 672                 fp = &f->fn_next;
 673         }
 674
 675         return found;
 676 }
 677
 678 static int dn_fib_table_flush(struct dn_fib_table *tb)
 679 {
 680         struct dn_hash *table = (struct dn_hash *)tb->data;
 681         struct dn_zone *dz;
 682         int found = 0;
 683
 684         dn_fib_hash_zombies = 0;
 685         for(dz = table->dh_zone_list; dz; dz = dz->dz_next) {
 686                 int i;
 687                 int tmp = 0;
 688                 for(i = dz->dz_divisor-1; i >= 0; i--)
 689                         tmp += dn_flush_list(&dz->dz_hash[i], dz->dz_order, table);
 690                 dz->dz_nent -= tmp;
 691                 found += tmp;
 692         }
 693
 694         return found;
 695 }
 696
 697 static int dn_fib_table_lookup(struct dn_fib_table *tb, const struct flowi *flp, struct dn_fib_res *res)
 698 {
 699         int err;
 700         struct dn_zone *dz;
 701         struct dn_hash *t = (struct dn_hash *)tb->data;
 702
 703         read_lock(&dn_fib_tables_lock);
 704         for(dz = t->dh_zone_list; dz; dz = dz->dz_next) {
 705                 struct dn_fib_node *f;
 706                 dn_fib_key_t k = dz_key(flp->fld_dst, dz);
 707
 708                 for(f = dz_chain(k, dz); f; f = f->fn_next) {
 709                         if (!dn_key_eq(k, f->fn_key)) {
 710                                 if (dn_key_leq(k, f->fn_key))
 711                                         break;
 712                                 else
 713                                         continue;
 714                         }
 715
 716                         f->fn_state |= DN_S_ACCESSED;
 717
 718                         if (f->fn_state&DN_S_ZOMBIE)
 719                                 continue;
 720
 721                         if (f->fn_scope < flp->fld_scope)
 722                                 continue;
 723
 724                         err = dn_fib_semantic_match(f->fn_type, DN_FIB_INFO(f), flp, res);
 725
 726                         if (err == 0) {
 727                                 res->type = f->fn_type;
 728                                 res->scope = f->fn_scope;
 729                                 res->prefixlen = dz->dz_order;
 730                                 goto out;
 731                         }
 732                         if (err < 0)
 733                                 goto out;
 734                 }
 735         }
 736         err = 1;
 737 out:
 738         read_unlock(&dn_fib_tables_lock);
 739         return err;
 740 }
 741
 742
 743 struct dn_fib_table *dn_fib_get_table(u32 n, int create)
 744 {
 745         struct dn_fib_table *t;
 746
 747         if (n < RT_TABLE_MIN)
 748                 return NULL;
 749
 750         if (n > RT_TABLE_MAX)
 751                 return NULL;
 752
 753         if (dn_fib_tables[n])
 754                 return dn_fib_tables[n];
 755
 756         if (!create)
 757                 return NULL;
 758
 759         if (in_interrupt() && net_ratelimit()) {
 760                 printk(KERN_DEBUG "DECnet: BUG! Attempt to create routing table from interrupt\n");
 761                 return NULL;
 762         }
 763         if ((t = kmalloc(sizeof(struct dn_fib_table) + sizeof(struct dn_hash), GFP_KERNEL)) == NULL)
 764                 return NULL;
 765
 766         memset(t, 0, sizeof(struct dn_fib_table));
 767
 768         t->n = n;
 769         t->insert = dn_fib_table_insert;
 770         t->delete = dn_fib_table_delete;
 771         t->lookup = dn_fib_table_lookup;
 772         t->flush  = dn_fib_table_flush;
 773         t->dump = dn_fib_table_dump;
 774         memset(t->data, 0, sizeof(struct dn_hash));
 775         dn_fib_tables[n] = t;
 776
 777         return t;
 778 }
 779
 780 static void dn_fib_del_tree(u32 n)
 781 {
 782         struct dn_fib_table *t;
 783
 784         write_lock(&dn_fib_tables_lock);
 785         t = dn_fib_tables[n];
 786         dn_fib_tables[n] = NULL;
 787         write_unlock(&dn_fib_tables_lock);
 788
 789         kfree(t);
 790 }
 791
 792 struct dn_fib_table *dn_fib_empty_table(void)
 793 {
 794         u32 id;
 795
 796         for(id = RT_TABLE_MIN; id <= RT_TABLE_MAX; id++)
 797                 if (dn_fib_tables[id] == NULL)
 798                         return dn_fib_get_table(id, 1);
 799         return NULL;
 800 }
 801
 802 void __init dn_fib_table_init(void)
 803 {
 804         dn_hash_kmem = kmem_cache_create("dn_fib_info_cache",
 805                                         sizeof(struct dn_fib_info),
 806                                         0, SLAB_HWCACHE_ALIGN,
 807                                         NULL, NULL);
 808 }
 809
 810 void __exit dn_fib_table_cleanup(void)
 811 {
 812         int i;
 813
 814         for (i = RT_TABLE_MIN; i <= RT_TABLE_MAX; ++i)
 815                 dn_fib_del_tree(i);
 816
 817         return;
 818 }