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/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 #define DN_FIB_TABLE_HASHSZ 256
  79 static struct hlist_head dn_fib_table_hash[DN_FIB_TABLE_HASHSZ];
  80 static DEFINE_RWLOCK(dn_fib_tables_lock);
  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         RTA_PUT_U32(skb, RTA_TABLE, tb_id);
 282         rtm->rtm_flags = fi->fib_flags;
 283         rtm->rtm_scope = scope;
 284         rtm->rtm_type  = type;
 285         if (rtm->rtm_dst_len)
 286                 RTA_PUT(skb, RTA_DST, 2, dst);
 287         rtm->rtm_protocol = fi->fib_protocol;
 288         if (fi->fib_priority)
 289                 RTA_PUT(skb, RTA_PRIORITY, 4, &fi->fib_priority);
 290         if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0)
 291                 goto rtattr_failure;
 292         if (fi->fib_nhs == 1) {
 293                 if (fi->fib_nh->nh_gw)
 294                         RTA_PUT(skb, RTA_GATEWAY, 2, &fi->fib_nh->nh_gw);
 295                 if (fi->fib_nh->nh_oif)
 296                         RTA_PUT(skb, RTA_OIF, sizeof(int), &fi->fib_nh->nh_oif);
 297         }
 298         if (fi->fib_nhs > 1) {
 299                 struct rtnexthop *nhp;
 300                 struct rtattr *mp_head;
 301                 if (skb_tailroom(skb) <= RTA_SPACE(0))
 302                         goto rtattr_failure;
 303                 mp_head = (struct rtattr *)skb_put(skb, RTA_SPACE(0));
 304
 305                 for_nexthops(fi) {
 306                         if (skb_tailroom(skb) < RTA_ALIGN(RTA_ALIGN(sizeof(*nhp)) + 4))
 307                                 goto rtattr_failure;
 308                         nhp = (struct rtnexthop *)skb_put(skb, RTA_ALIGN(sizeof(*nhp)));
 309                         nhp->rtnh_flags = nh->nh_flags & 0xFF;
 310                         nhp->rtnh_hops = nh->nh_weight - 1;
 311                         nhp->rtnh_ifindex = nh->nh_oif;
 312                         if (nh->nh_gw)
 313                                 RTA_PUT(skb, RTA_GATEWAY, 2, &nh->nh_gw);
 314                         nhp->rtnh_len = skb->tail - (unsigned char *)nhp;
 315                 } endfor_nexthops(fi);
 316                 mp_head->rta_type = RTA_MULTIPATH;
 317                 mp_head->rta_len = skb->tail - (u8*)mp_head;
 318         }
 319
 320         nlh->nlmsg_len = skb->tail - b;
 321         return skb->len;
 322
 323
 324 nlmsg_failure:
 325 rtattr_failure:
 326         skb_trim(skb, b - skb->data);
 327         return -1;
 328 }
 329
 330
 331 static void dn_rtmsg_fib(int event, struct dn_fib_node *f, int z, u32 tb_id,
 332                         struct nlmsghdr *nlh, struct netlink_skb_parms *req)
 333 {
 334         struct sk_buff *skb;
 335         u32 pid = req ? req->pid : 0;
 336         int err = -ENOBUFS;
 337
 338         skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
 339         if (skb == NULL)
 340                 goto errout;
 341
 342         err = dn_fib_dump_info(skb, pid, nlh->nlmsg_seq, event, tb_id,
 343                                f->fn_type, f->fn_scope, &f->fn_key, z,
 344                                DN_FIB_INFO(f), 0);
 345         if (err < 0) {
 346                 kfree_skb(skb);
 347                 goto errout;
 348         }
 349
 350         err = rtnl_notify(skb, pid, RTNLGRP_DECnet_ROUTE, nlh, GFP_KERNEL);
 351 errout:
 352         if (err < 0)
 353                 rtnl_set_sk_err(RTNLGRP_DECnet_ROUTE, err);
 354 }
 355
 356 static __inline__ int dn_hash_dump_bucket(struct sk_buff *skb,
 357                                 struct netlink_callback *cb,
 358                                 struct dn_fib_table *tb,
 359                                 struct dn_zone *dz,
 360                                 struct dn_fib_node *f)
 361 {
 362         int i, s_i;
 363
 364         s_i = cb->args[4];
 365         for(i = 0; f; i++, f = f->fn_next) {
 366                 if (i < s_i)
 367                         continue;
 368                 if (f->fn_state & DN_S_ZOMBIE)
 369                         continue;
 370                 if (dn_fib_dump_info(skb, NETLINK_CB(cb->skb).pid,
 371                                 cb->nlh->nlmsg_seq,
 372                                 RTM_NEWROUTE,
 373                                 tb->n,
 374                                 (f->fn_state & DN_S_ZOMBIE) ? 0 : f->fn_type,
 375                                 f->fn_scope, &f->fn_key, dz->dz_order,
 376                                 f->fn_info, NLM_F_MULTI) < 0) {
 377                         cb->args[4] = i;
 378                         return -1;
 379                 }
 380         }
 381         cb->args[4] = i;
 382         return skb->len;
 383 }
 384
 385 static __inline__ int dn_hash_dump_zone(struct sk_buff *skb,
 386                                 struct netlink_callback *cb,
 387                                 struct dn_fib_table *tb,
 388                                 struct dn_zone *dz)
 389 {
 390         int h, s_h;
 391
 392         s_h = cb->args[3];
 393         for(h = 0; h < dz->dz_divisor; h++) {
 394                 if (h < s_h)
 395                         continue;
 396                 if (h > s_h)
 397                         memset(&cb->args[4], 0, sizeof(cb->args) - 4*sizeof(cb->args[0]));
 398                 if (dz->dz_hash == NULL || dz->dz_hash[h] == NULL)
 399                         continue;
 400                 if (dn_hash_dump_bucket(skb, cb, tb, dz, dz->dz_hash[h]) < 0) {
 401                         cb->args[3] = h;
 402                         return -1;
 403                 }
 404         }
 405         cb->args[3] = h;
 406         return skb->len;
 407 }
 408
 409 static int dn_fib_table_dump(struct dn_fib_table *tb, struct sk_buff *skb,
 410                                 struct netlink_callback *cb)
 411 {
 412         int m, s_m;
 413         struct dn_zone *dz;
 414         struct dn_hash *table = (struct dn_hash *)tb->data;
 415
 416         s_m = cb->args[2];
 417         read_lock(&dn_fib_tables_lock);
 418         for(dz = table->dh_zone_list, m = 0; dz; dz = dz->dz_next, m++) {
 419                 if (m < s_m)
 420                         continue;
 421                 if (m > s_m)
 422                         memset(&cb->args[3], 0, sizeof(cb->args) - 3*sizeof(cb->args[0]));
 423
 424                 if (dn_hash_dump_zone(skb, cb, tb, dz) < 0) {
 425                         cb->args[2] = m;
 426                         read_unlock(&dn_fib_tables_lock);
 427                         return -1;
 428                 }
 429         }
 430         read_unlock(&dn_fib_tables_lock);
 431         cb->args[2] = m;
 432
 433         return skb->len;
 434 }
 435
 436 int dn_fib_dump(struct sk_buff *skb, struct netlink_callback *cb)
 437 {
 438         unsigned int h, s_h;
 439         unsigned int e = 0, s_e;
 440         struct dn_fib_table *tb;
 441         struct hlist_node *node;
 442         int dumped = 0;
 443
 444         if (NLMSG_PAYLOAD(cb->nlh, 0) >= sizeof(struct rtmsg) &&
 445                 ((struct rtmsg *)NLMSG_DATA(cb->nlh))->rtm_flags&RTM_F_CLONED)
 446                         return dn_cache_dump(skb, cb);
 447
 448         s_h = cb->args[0];
 449         s_e = cb->args[1];
 450
 451         for (h = s_h; h < DN_FIB_TABLE_HASHSZ; h++, s_h = 0) {
 452                 e = 0;
 453                 hlist_for_each_entry(tb, node, &dn_fib_table_hash[h], hlist) {
 454                         if (e < s_e)
 455                                 goto next;
 456                         if (dumped)
 457                                 memset(&cb->args[2], 0, sizeof(cb->args) -
 458                                                  2 * sizeof(cb->args[0]));
 459                         if (tb->dump(tb, skb, cb) < 0)
 460                                 goto out;
 461                         dumped = 1;
 462 next:
 463                         e++;
 464                 }
 465         }
 466 out:
 467         cb->args[1] = e;
 468         cb->args[0] = h;
 469
 470         return skb->len;
 471 }
 472
 473 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)
 474 {
 475         struct dn_hash *table = (struct dn_hash *)tb->data;
 476         struct dn_fib_node *new_f, *f, **fp, **del_fp;
 477         struct dn_zone *dz;
 478         struct dn_fib_info *fi;
 479         int z = r->rtm_dst_len;
 480         int type = r->rtm_type;
 481         dn_fib_key_t key;
 482         int err;
 483
 484         if (z > 16)
 485                 return -EINVAL;
 486
 487         dz = table->dh_zones[z];
 488         if (!dz && !(dz = dn_new_zone(table, z)))
 489                 return -ENOBUFS;
 490
 491         dz_key_0(key);
 492         if (rta->rta_dst) {
 493                 __le16 dst;
 494                 memcpy(&dst, rta->rta_dst, 2);
 495                 if (dst & ~DZ_MASK(dz))
 496                         return -EINVAL;
 497                 key = dz_key(dst, dz);
 498         }
 499
 500         if ((fi = dn_fib_create_info(r, rta, n, &err)) == NULL)
 501                 return err;
 502
 503         if (dz->dz_nent > (dz->dz_divisor << 2) &&
 504                         dz->dz_divisor > DN_MAX_DIVISOR &&
 505                         (z==16 || (1<<z) > dz->dz_divisor))
 506                 dn_rehash_zone(dz);
 507
 508         fp = dn_chain_p(key, dz);
 509
 510         DN_FIB_SCAN(f, fp) {
 511                 if (dn_key_leq(key, f->fn_key))
 512                         break;
 513         }
 514
 515         del_fp = NULL;
 516
 517         if (f && (f->fn_state & DN_S_ZOMBIE) &&
 518                         dn_key_eq(f->fn_key, key)) {
 519                 del_fp = fp;
 520                 fp = &f->fn_next;
 521                 f = *fp;
 522                 goto create;
 523         }
 524
 525         DN_FIB_SCAN_KEY(f, fp, key) {
 526                 if (fi->fib_priority <= DN_FIB_INFO(f)->fib_priority)
 527                         break;
 528         }
 529
 530         if (f && dn_key_eq(f->fn_key, key) &&
 531                         fi->fib_priority == DN_FIB_INFO(f)->fib_priority) {
 532                 struct dn_fib_node **ins_fp;
 533
 534                 err = -EEXIST;
 535                 if (n->nlmsg_flags & NLM_F_EXCL)
 536                         goto out;
 537
 538                 if (n->nlmsg_flags & NLM_F_REPLACE) {
 539                         del_fp = fp;
 540                         fp = &f->fn_next;
 541                         f = *fp;
 542                         goto replace;
 543                 }
 544
 545                 ins_fp = fp;
 546                 err = -EEXIST;
 547
 548                 DN_FIB_SCAN_KEY(f, fp, key) {
 549                         if (fi->fib_priority != DN_FIB_INFO(f)->fib_priority)
 550                                 break;
 551                         if (f->fn_type == type && f->fn_scope == r->rtm_scope
 552                                         && DN_FIB_INFO(f) == fi)
 553                                 goto out;
 554                 }
 555
 556                 if (!(n->nlmsg_flags & NLM_F_APPEND)) {
 557                         fp = ins_fp;
 558                         f = *fp;
 559                 }
 560         }
 561
 562 create:
 563         err = -ENOENT;
 564         if (!(n->nlmsg_flags & NLM_F_CREATE))
 565                 goto out;
 566
 567 replace:
 568         err = -ENOBUFS;
 569         new_f = kmem_cache_alloc(dn_hash_kmem, SLAB_KERNEL);
 570         if (new_f == NULL)
 571                 goto out;
 572
 573         memset(new_f, 0, sizeof(struct dn_fib_node));
 574
 575         new_f->fn_key = key;
 576         new_f->fn_type = type;
 577         new_f->fn_scope = r->rtm_scope;
 578         DN_FIB_INFO(new_f) = fi;
 579
 580         new_f->fn_next = f;
 581         write_lock_bh(&dn_fib_tables_lock);
 582         *fp = new_f;
 583         write_unlock_bh(&dn_fib_tables_lock);
 584         dz->dz_nent++;
 585
 586         if (del_fp) {
 587                 f = *del_fp;
 588                 write_lock_bh(&dn_fib_tables_lock);
 589                 *del_fp = f->fn_next;
 590                 write_unlock_bh(&dn_fib_tables_lock);
 591
 592                 if (!(f->fn_state & DN_S_ZOMBIE))
 593                         dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 594                 if (f->fn_state & DN_S_ACCESSED)
 595                         dn_rt_cache_flush(-1);
 596                 dn_free_node(f);
 597                 dz->dz_nent--;
 598         } else {
 599                 dn_rt_cache_flush(-1);
 600         }
 601
 602         dn_rtmsg_fib(RTM_NEWROUTE, new_f, z, tb->n, n, req);
 603
 604         return 0;
 605 out:
 606         dn_fib_release_info(fi);
 607         return err;
 608 }
 609
 610
 611 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)
 612 {
 613         struct dn_hash *table = (struct dn_hash*)tb->data;
 614         struct dn_fib_node **fp, **del_fp, *f;
 615         int z = r->rtm_dst_len;
 616         struct dn_zone *dz;
 617         dn_fib_key_t key;
 618         int matched;
 619
 620
 621         if (z > 16)
 622                 return -EINVAL;
 623
 624         if ((dz = table->dh_zones[z]) == NULL)
 625                 return -ESRCH;
 626
 627         dz_key_0(key);
 628         if (rta->rta_dst) {
 629                 __le16 dst;
 630                 memcpy(&dst, rta->rta_dst, 2);
 631                 if (dst & ~DZ_MASK(dz))
 632                         return -EINVAL;
 633                 key = dz_key(dst, dz);
 634         }
 635
 636         fp = dn_chain_p(key, dz);
 637
 638         DN_FIB_SCAN(f, fp) {
 639                 if (dn_key_eq(f->fn_key, key))
 640                         break;
 641                 if (dn_key_leq(key, f->fn_key))
 642                         return -ESRCH;
 643         }
 644
 645         matched = 0;
 646         del_fp = NULL;
 647         DN_FIB_SCAN_KEY(f, fp, key) {
 648                 struct dn_fib_info *fi = DN_FIB_INFO(f);
 649
 650                 if (f->fn_state & DN_S_ZOMBIE)
 651                         return -ESRCH;
 652
 653                 matched++;
 654
 655                 if (del_fp == NULL &&
 656                                 (!r->rtm_type || f->fn_type == r->rtm_type) &&
 657                                 (r->rtm_scope == RT_SCOPE_NOWHERE || f->fn_scope == r->rtm_scope) &&
 658                                 (!r->rtm_protocol ||
 659                                         fi->fib_protocol == r->rtm_protocol) &&
 660                                 dn_fib_nh_match(r, n, rta, fi) == 0)
 661                         del_fp = fp;
 662         }
 663
 664         if (del_fp) {
 665                 f = *del_fp;
 666                 dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 667
 668                 if (matched != 1) {
 669                         write_lock_bh(&dn_fib_tables_lock);
 670                         *del_fp = f->fn_next;
 671                         write_unlock_bh(&dn_fib_tables_lock);
 672
 673                         if (f->fn_state & DN_S_ACCESSED)
 674                                 dn_rt_cache_flush(-1);
 675                         dn_free_node(f);
 676                         dz->dz_nent--;
 677                 } else {
 678                         f->fn_state |= DN_S_ZOMBIE;
 679                         if (f->fn_state & DN_S_ACCESSED) {
 680                                 f->fn_state &= ~DN_S_ACCESSED;
 681                                 dn_rt_cache_flush(-1);
 682                         }
 683                         if (++dn_fib_hash_zombies > 128)
 684                                 dn_fib_flush();
 685                 }
 686
 687                 return 0;
 688         }
 689
 690         return -ESRCH;
 691 }
 692
 693 static inline int dn_flush_list(struct dn_fib_node **fp, int z, struct dn_hash *table)
 694 {
 695         int found = 0;
 696         struct dn_fib_node *f;
 697
 698         while((f = *fp) != NULL) {
 699                 struct dn_fib_info *fi = DN_FIB_INFO(f);
 700
 701                 if (fi && ((f->fn_state & DN_S_ZOMBIE) || (fi->fib_flags & RTNH_F_DEAD))) {
 702                         write_lock_bh(&dn_fib_tables_lock);
 703                         *fp = f->fn_next;
 704                         write_unlock_bh(&dn_fib_tables_lock);
 705
 706                         dn_free_node(f);
 707                         found++;
 708                         continue;
 709                 }
 710                 fp = &f->fn_next;
 711         }
 712
 713         return found;
 714 }
 715
 716 static int dn_fib_table_flush(struct dn_fib_table *tb)
 717 {
 718         struct dn_hash *table = (struct dn_hash *)tb->data;
 719         struct dn_zone *dz;
 720         int found = 0;
 721
 722         dn_fib_hash_zombies = 0;
 723         for(dz = table->dh_zone_list; dz; dz = dz->dz_next) {
 724                 int i;
 725                 int tmp = 0;
 726                 for(i = dz->dz_divisor-1; i >= 0; i--)
 727                         tmp += dn_flush_list(&dz->dz_hash[i], dz->dz_order, table);
 728                 dz->dz_nent -= tmp;
 729                 found += tmp;
 730         }
 731
 732         return found;
 733 }
 734
 735 static int dn_fib_table_lookup(struct dn_fib_table *tb, const struct flowi *flp, struct dn_fib_res *res)
 736 {
 737         int err;
 738         struct dn_zone *dz;
 739         struct dn_hash *t = (struct dn_hash *)tb->data;
 740
 741         read_lock(&dn_fib_tables_lock);
 742         for(dz = t->dh_zone_list; dz; dz = dz->dz_next) {
 743                 struct dn_fib_node *f;
 744                 dn_fib_key_t k = dz_key(flp->fld_dst, dz);
 745
 746                 for(f = dz_chain(k, dz); f; f = f->fn_next) {
 747                         if (!dn_key_eq(k, f->fn_key)) {
 748                                 if (dn_key_leq(k, f->fn_key))
 749                                         break;
 750                                 else
 751                                         continue;
 752                         }
 753
 754                         f->fn_state |= DN_S_ACCESSED;
 755
 756                         if (f->fn_state&DN_S_ZOMBIE)
 757                                 continue;
 758
 759                         if (f->fn_scope < flp->fld_scope)
 760                                 continue;
 761
 762                         err = dn_fib_semantic_match(f->fn_type, DN_FIB_INFO(f), flp, res);
 763
 764                         if (err == 0) {
 765                                 res->type = f->fn_type;
 766                                 res->scope = f->fn_scope;
 767                                 res->prefixlen = dz->dz_order;
 768                                 goto out;
 769                         }
 770                         if (err < 0)
 771                                 goto out;
 772                 }
 773         }
 774         err = 1;
 775 out:
 776         read_unlock(&dn_fib_tables_lock);
 777         return err;
 778 }
 779
 780
 781 struct dn_fib_table *dn_fib_get_table(u32 n, int create)
 782 {
 783         struct dn_fib_table *t;
 784         struct hlist_node *node;
 785         unsigned int h;
 786
 787         if (n < RT_TABLE_MIN)
 788                 return NULL;
 789
 790         if (n > RT_TABLE_MAX)
 791                 return NULL;
 792
 793         h = n & (DN_FIB_TABLE_HASHSZ - 1);
 794         rcu_read_lock();
 795         hlist_for_each_entry_rcu(t, node, &dn_fib_table_hash[h], hlist) {
 796                 if (t->n == n) {
 797                         rcu_read_unlock();
 798                         return t;
 799                 }
 800         }
 801         rcu_read_unlock();
 802
 803         if (!create)
 804                 return NULL;
 805
 806         if (in_interrupt() && net_ratelimit()) {
 807                 printk(KERN_DEBUG "DECnet: BUG! Attempt to create routing table from interrupt\n");
 808                 return NULL;
 809         }
 810         if ((t = kmalloc(sizeof(struct dn_fib_table) + sizeof(struct dn_hash), GFP_KERNEL)) == NULL)
 811                 return NULL;
 812
 813         memset(t, 0, sizeof(struct dn_fib_table));
 814
 815         t->n = n;
 816         t->insert = dn_fib_table_insert;
 817         t->delete = dn_fib_table_delete;
 818         t->lookup = dn_fib_table_lookup;
 819         t->flush  = dn_fib_table_flush;
 820         t->dump = dn_fib_table_dump;
 821         memset(t->data, 0, sizeof(struct dn_hash));
 822         hlist_add_head_rcu(&t->hlist, &dn_fib_table_hash[h]);
 823
 824         return t;
 825 }
 826
 827 struct dn_fib_table *dn_fib_empty_table(void)
 828 {
 829         u32 id;
 830
 831         for(id = RT_TABLE_MIN; id <= RT_TABLE_MAX; id++)
 832                 if (dn_fib_get_table(id, 0) == NULL)
 833                         return dn_fib_get_table(id, 1);
 834         return NULL;
 835 }
 836
 837 void dn_fib_flush(void)
 838 {
 839         int flushed = 0;
 840         struct dn_fib_table *tb;
 841         struct hlist_node *node;
 842         unsigned int h;
 843
 844         for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
 845                 hlist_for_each_entry(tb, node, &dn_fib_table_hash[h], hlist)
 846                         flushed += tb->flush(tb);
 847         }
 848
 849         if (flushed)
 850                 dn_rt_cache_flush(-1);
 851 }
 852
 853 void __init dn_fib_table_init(void)
 854 {
 855         dn_hash_kmem = kmem_cache_create("dn_fib_info_cache",
 856                                         sizeof(struct dn_fib_info),
 857                                         0, SLAB_HWCACHE_ALIGN,
 858                                         NULL, NULL);
 859 }
 860
 861 void __exit dn_fib_table_cleanup(void)
 862 {
 863         struct dn_fib_table *t;
 864         struct hlist_node *node, *next;
 865         unsigned int h;
 866
 867         write_lock(&dn_fib_tables_lock);
 868         for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
 869                 hlist_for_each_entry_safe(t, node, next, &dn_fib_table_hash[h],
 870                                           hlist) {
 871                         hlist_del(&t->hlist);
 872                         kfree(t);
 873                 }
 874         }
 875         write_unlock(&dn_fib_tables_lock);
 876 }