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/slab.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 <linux/atomic.h>
  29 #include <asm/uaccess.h>
  30 #include <linux/route.h> /* RTF_xxx */
  31 #include <net/neighbour.h>
  32 #include <net/netlink.h>
  33 #include <net/dst.h>
  34 #include <net/flow.h>
  35 #include <net/fib_rules.h>
  36 #include <net/dn.h>
  37 #include <net/dn_route.h>
  38 #include <net/dn_fib.h>
  39 #include <net/dn_neigh.h>
  40 #include <net/dn_dev.h>
  41
  42 struct dn_zone
  43 {
  44         struct dn_zone          *dz_next;
  45         struct dn_fib_node      **dz_hash;
  46         int                     dz_nent;
  47         int                     dz_divisor;
  48         u32                     dz_hashmask;
  49 #define DZ_HASHMASK(dz) ((dz)->dz_hashmask)
  50         int                     dz_order;
  51         __le16                  dz_mask;
  52 #define DZ_MASK(dz)     ((dz)->dz_mask)
  53 };
  54
  55 struct dn_hash
  56 {
  57         struct dn_zone  *dh_zones[17];
  58         struct dn_zone  *dh_zone_list;
  59 };
  60
  61 #define dz_key_0(key)           ((key).datum = 0)
  62
  63 #define for_nexthops(fi) { int nhsel; const struct dn_fib_nh *nh;\
  64         for(nhsel = 0, nh = (fi)->fib_nh; nhsel < (fi)->fib_nhs; nh++, nhsel++)
  65
  66 #define endfor_nexthops(fi) }
  67
  68 #define DN_MAX_DIVISOR 1024
  69 #define DN_S_ZOMBIE 1
  70 #define DN_S_ACCESSED 2
  71
  72 #define DN_FIB_SCAN(f, fp) \
  73 for( ; ((f) = *(fp)) != NULL; (fp) = &(f)->fn_next)
  74
  75 #define DN_FIB_SCAN_KEY(f, fp, key) \
  76 for( ; ((f) = *(fp)) != NULL && dn_key_eq((f)->fn_key, (key)); (fp) = &(f)->fn_next)
  77
  78 #define RT_TABLE_MIN 1
  79 #define DN_FIB_TABLE_HASHSZ 256
  80 static struct hlist_head dn_fib_table_hash[DN_FIB_TABLE_HASHSZ];
  81 static DEFINE_RWLOCK(dn_fib_tables_lock);
  82
  83 static struct kmem_cache *dn_hash_kmem __read_mostly;
  84 static int dn_fib_hash_zombies;
  85
  86 static inline dn_fib_idx_t dn_hash(dn_fib_key_t key, struct dn_zone *dz)
  87 {
  88         u16 h = le16_to_cpu(key.datum)>>(16 - dz->dz_order);
  89         h ^= (h >> 10);
  90         h ^= (h >> 6);
  91         h &= DZ_HASHMASK(dz);
  92         return *(dn_fib_idx_t *)&h;
  93 }
  94
  95 static inline dn_fib_key_t dz_key(__le16 dst, struct dn_zone *dz)
  96 {
  97         dn_fib_key_t k;
  98         k.datum = dst & DZ_MASK(dz);
  99         return k;
 100 }
 101
 102 static inline struct dn_fib_node **dn_chain_p(dn_fib_key_t key, struct dn_zone *dz)
 103 {
 104         return &dz->dz_hash[dn_hash(key, dz).datum];
 105 }
 106
 107 static inline struct dn_fib_node *dz_chain(dn_fib_key_t key, struct dn_zone *dz)
 108 {
 109         return dz->dz_hash[dn_hash(key, dz).datum];
 110 }
 111
 112 static inline int dn_key_eq(dn_fib_key_t a, dn_fib_key_t b)
 113 {
 114         return a.datum == b.datum;
 115 }
 116
 117 static inline int dn_key_leq(dn_fib_key_t a, dn_fib_key_t b)
 118 {
 119         return a.datum <= b.datum;
 120 }
 121
 122 static inline void dn_rebuild_zone(struct dn_zone *dz,
 123                                    struct dn_fib_node **old_ht,
 124                                    int old_divisor)
 125 {
 126         struct dn_fib_node *f, **fp, *next;
 127         int i;
 128
 129         for(i = 0; i < old_divisor; i++) {
 130                 for(f = old_ht[i]; f; f = next) {
 131                         next = f->fn_next;
 132                         for(fp = dn_chain_p(f->fn_key, dz);
 133                                 *fp && dn_key_leq((*fp)->fn_key, f->fn_key);
 134                                 fp = &(*fp)->fn_next)
 135                                 /* NOTHING */;
 136                         f->fn_next = *fp;
 137                         *fp = f;
 138                 }
 139         }
 140 }
 141
 142 static void dn_rehash_zone(struct dn_zone *dz)
 143 {
 144         struct dn_fib_node **ht, **old_ht;
 145         int old_divisor, new_divisor;
 146         u32 new_hashmask;
 147
 148         old_divisor = dz->dz_divisor;
 149
 150         switch (old_divisor) {
 151         case 16:
 152                 new_divisor = 256;
 153                 new_hashmask = 0xFF;
 154                 break;
 155         default:
 156                 printk(KERN_DEBUG "DECnet: dn_rehash_zone: BUG! %d\n",
 157                        old_divisor);
 158         case 256:
 159                 new_divisor = 1024;
 160                 new_hashmask = 0x3FF;
 161                 break;
 162         }
 163
 164         ht = kcalloc(new_divisor, sizeof(struct dn_fib_node*), GFP_KERNEL);
 165         if (ht == NULL)
 166                 return;
 167
 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 = kzalloc(sizeof(struct dn_zone), GFP_KERNEL);
 189         if (!dz)
 190                 return NULL;
 191
 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 = kcalloc(dz->dz_divisor, sizeof(struct dn_fib_node *), GFP_KERNEL);
 201         if (!dz->dz_hash) {
 202                 kfree(dz);
 203                 return NULL;
 204         }
 205
 206         dz->dz_order = z;
 207         dz->dz_mask = dnet_make_mask(z);
 208
 209         for(i = z + 1; i <= 16; i++)
 210                 if (table->dh_zones[i])
 211                         break;
 212
 213         write_lock_bh(&dn_fib_tables_lock);
 214         if (i>16) {
 215                 dz->dz_next = table->dh_zone_list;
 216                 table->dh_zone_list = dz;
 217         } else {
 218                 dz->dz_next = table->dh_zones[i]->dz_next;
 219                 table->dh_zones[i]->dz_next = dz;
 220         }
 221         table->dh_zones[z] = dz;
 222         write_unlock_bh(&dn_fib_tables_lock);
 223         return dz;
 224 }
 225
 226
 227 static int dn_fib_nh_match(struct rtmsg *r, struct nlmsghdr *nlh, struct dn_kern_rta *rta, struct dn_fib_info *fi)
 228 {
 229         struct rtnexthop *nhp;
 230         int nhlen;
 231
 232         if (rta->rta_priority && *rta->rta_priority != fi->fib_priority)
 233                 return 1;
 234
 235         if (rta->rta_oif || rta->rta_gw) {
 236                 if ((!rta->rta_oif || *rta->rta_oif == fi->fib_nh->nh_oif) &&
 237                     (!rta->rta_gw  || memcmp(rta->rta_gw, &fi->fib_nh->nh_gw, 2) == 0))
 238                         return 0;
 239                 return 1;
 240         }
 241
 242         if (rta->rta_mp == NULL)
 243                 return 0;
 244
 245         nhp = RTA_DATA(rta->rta_mp);
 246         nhlen = RTA_PAYLOAD(rta->rta_mp);
 247
 248         for_nexthops(fi) {
 249                 int attrlen = nhlen - sizeof(struct rtnexthop);
 250                 __le16 gw;
 251
 252                 if (attrlen < 0 || (nhlen -= nhp->rtnh_len) < 0)
 253                         return -EINVAL;
 254                 if (nhp->rtnh_ifindex && nhp->rtnh_ifindex != nh->nh_oif)
 255                         return 1;
 256                 if (attrlen) {
 257                         gw = dn_fib_get_attr16(RTNH_DATA(nhp), attrlen, RTA_GATEWAY);
 258
 259                         if (gw && gw != nh->nh_gw)
 260                                 return 1;
 261                 }
 262                 nhp = RTNH_NEXT(nhp);
 263         } endfor_nexthops(fi);
 264
 265         return 0;
 266 }
 267
 268 static inline size_t dn_fib_nlmsg_size(struct dn_fib_info *fi)
 269 {
 270         size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg))
 271                          + nla_total_size(4) /* RTA_TABLE */
 272                          + nla_total_size(2) /* RTA_DST */
 273                          + nla_total_size(4); /* RTA_PRIORITY */
 274
 275         /* space for nested metrics */
 276         payload += nla_total_size((RTAX_MAX * nla_total_size(4)));
 277
 278         if (fi->fib_nhs) {
 279                 /* Also handles the special case fib_nhs == 1 */
 280
 281                 /* each nexthop is packed in an attribute */
 282                 size_t nhsize = nla_total_size(sizeof(struct rtnexthop));
 283
 284                 /* may contain a gateway attribute */
 285                 nhsize += nla_total_size(4);
 286
 287                 /* all nexthops are packed in a nested attribute */
 288                 payload += nla_total_size(fi->fib_nhs * nhsize);
 289         }
 290
 291         return payload;
 292 }
 293
 294 static int dn_fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event,
 295                         u32 tb_id, u8 type, u8 scope, void *dst, int dst_len,
 296                         struct dn_fib_info *fi, unsigned int flags)
 297 {
 298         struct rtmsg *rtm;
 299         struct nlmsghdr *nlh;
 300
 301         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags);
 302         if (!nlh)
 303                 return -EMSGSIZE;
 304
 305         rtm = nlmsg_data(nlh);
 306         rtm->rtm_family = AF_DECnet;
 307         rtm->rtm_dst_len = dst_len;
 308         rtm->rtm_src_len = 0;
 309         rtm->rtm_tos = 0;
 310         rtm->rtm_table = tb_id;
 311         rtm->rtm_flags = fi->fib_flags;
 312         rtm->rtm_scope = scope;
 313         rtm->rtm_type  = type;
 314         rtm->rtm_protocol = fi->fib_protocol;
 315
 316         if (nla_put_u32(skb, RTA_TABLE, tb_id) < 0)
 317                 goto errout;
 318
 319         if (rtm->rtm_dst_len &&
 320             nla_put(skb, RTA_DST, 2, dst) < 0)
 321                 goto errout;
 322
 323         if (fi->fib_priority &&
 324             nla_put_u32(skb, RTA_PRIORITY, fi->fib_priority) < 0)
 325                 goto errout;
 326
 327         if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0)
 328                 goto errout;
 329
 330         if (fi->fib_nhs == 1) {
 331                 if (fi->fib_nh->nh_gw &&
 332                     nla_put_le16(skb, RTA_GATEWAY, fi->fib_nh->nh_gw) < 0)
 333                         goto errout;
 334
 335                 if (fi->fib_nh->nh_oif &&
 336                     nla_put_u32(skb, RTA_OIF, fi->fib_nh->nh_oif) < 0)
 337                         goto errout;
 338         }
 339
 340         if (fi->fib_nhs > 1) {
 341                 struct rtnexthop *nhp;
 342                 struct nlattr *mp_head;
 343
 344                 if (!(mp_head = nla_nest_start(skb, RTA_MULTIPATH)))
 345                         goto errout;
 346
 347                 for_nexthops(fi) {
 348                         if (!(nhp = nla_reserve_nohdr(skb, sizeof(*nhp))))
 349                                 goto errout;
 350
 351                         nhp->rtnh_flags = nh->nh_flags & 0xFF;
 352                         nhp->rtnh_hops = nh->nh_weight - 1;
 353                         nhp->rtnh_ifindex = nh->nh_oif;
 354
 355                         if (nh->nh_gw &&
 356                             nla_put_le16(skb, RTA_GATEWAY, nh->nh_gw) < 0)
 357                                 goto errout;
 358
 359                         nhp->rtnh_len = skb_tail_pointer(skb) - (unsigned char *)nhp;
 360                 } endfor_nexthops(fi);
 361
 362                 nla_nest_end(skb, mp_head);
 363         }
 364
 365         return nlmsg_end(skb, nlh);
 366
 367 errout:
 368         nlmsg_cancel(skb, nlh);
 369         return -EMSGSIZE;
 370 }
 371
 372
 373 static void dn_rtmsg_fib(int event, struct dn_fib_node *f, int z, u32 tb_id,
 374                         struct nlmsghdr *nlh, struct netlink_skb_parms *req)
 375 {
 376         struct sk_buff *skb;
 377         u32 portid = req ? req->portid : 0;
 378         int err = -ENOBUFS;
 379
 380         skb = nlmsg_new(dn_fib_nlmsg_size(DN_FIB_INFO(f)), GFP_KERNEL);
 381         if (skb == NULL)
 382                 goto errout;
 383
 384         err = dn_fib_dump_info(skb, portid, nlh->nlmsg_seq, event, tb_id,
 385                                f->fn_type, f->fn_scope, &f->fn_key, z,
 386                                DN_FIB_INFO(f), 0);
 387         if (err < 0) {
 388                 /* -EMSGSIZE implies BUG in dn_fib_nlmsg_size() */
 389                 WARN_ON(err == -EMSGSIZE);
 390                 kfree_skb(skb);
 391                 goto errout;
 392         }
 393         rtnl_notify(skb, &init_net, portid, RTNLGRP_DECnet_ROUTE, nlh, GFP_KERNEL);
 394         return;
 395 errout:
 396         if (err < 0)
 397                 rtnl_set_sk_err(&init_net, RTNLGRP_DECnet_ROUTE, err);
 398 }
 399
 400 static __inline__ int dn_hash_dump_bucket(struct sk_buff *skb,
 401                                 struct netlink_callback *cb,
 402                                 struct dn_fib_table *tb,
 403                                 struct dn_zone *dz,
 404                                 struct dn_fib_node *f)
 405 {
 406         int i, s_i;
 407
 408         s_i = cb->args[4];
 409         for(i = 0; f; i++, f = f->fn_next) {
 410                 if (i < s_i)
 411                         continue;
 412                 if (f->fn_state & DN_S_ZOMBIE)
 413                         continue;
 414                 if (dn_fib_dump_info(skb, NETLINK_CB(cb->skb).portid,
 415                                 cb->nlh->nlmsg_seq,
 416                                 RTM_NEWROUTE,
 417                                 tb->n,
 418                                 (f->fn_state & DN_S_ZOMBIE) ? 0 : f->fn_type,
 419                                 f->fn_scope, &f->fn_key, dz->dz_order,
 420                                 f->fn_info, NLM_F_MULTI) < 0) {
 421                         cb->args[4] = i;
 422                         return -1;
 423                 }
 424         }
 425         cb->args[4] = i;
 426         return skb->len;
 427 }
 428
 429 static __inline__ int dn_hash_dump_zone(struct sk_buff *skb,
 430                                 struct netlink_callback *cb,
 431                                 struct dn_fib_table *tb,
 432                                 struct dn_zone *dz)
 433 {
 434         int h, s_h;
 435
 436         s_h = cb->args[3];
 437         for(h = 0; h < dz->dz_divisor; h++) {
 438                 if (h < s_h)
 439                         continue;
 440                 if (h > s_h)
 441                         memset(&cb->args[4], 0, sizeof(cb->args) - 4*sizeof(cb->args[0]));
 442                 if (dz->dz_hash == NULL || dz->dz_hash[h] == NULL)
 443                         continue;
 444                 if (dn_hash_dump_bucket(skb, cb, tb, dz, dz->dz_hash[h]) < 0) {
 445                         cb->args[3] = h;
 446                         return -1;
 447                 }
 448         }
 449         cb->args[3] = h;
 450         return skb->len;
 451 }
 452
 453 static int dn_fib_table_dump(struct dn_fib_table *tb, struct sk_buff *skb,
 454                                 struct netlink_callback *cb)
 455 {
 456         int m, s_m;
 457         struct dn_zone *dz;
 458         struct dn_hash *table = (struct dn_hash *)tb->data;
 459
 460         s_m = cb->args[2];
 461         read_lock(&dn_fib_tables_lock);
 462         for(dz = table->dh_zone_list, m = 0; dz; dz = dz->dz_next, m++) {
 463                 if (m < s_m)
 464                         continue;
 465                 if (m > s_m)
 466                         memset(&cb->args[3], 0, sizeof(cb->args) - 3*sizeof(cb->args[0]));
 467
 468                 if (dn_hash_dump_zone(skb, cb, tb, dz) < 0) {
 469                         cb->args[2] = m;
 470                         read_unlock(&dn_fib_tables_lock);
 471                         return -1;
 472                 }
 473         }
 474         read_unlock(&dn_fib_tables_lock);
 475         cb->args[2] = m;
 476
 477         return skb->len;
 478 }
 479
 480 int dn_fib_dump(struct sk_buff *skb, struct netlink_callback *cb)
 481 {
 482         struct net *net = sock_net(skb->sk);
 483         unsigned int h, s_h;
 484         unsigned int e = 0, s_e;
 485         struct dn_fib_table *tb;
 486         struct hlist_node *node;
 487         int dumped = 0;
 488
 489         if (!net_eq(net, &init_net))
 490                 return 0;
 491
 492         if (NLMSG_PAYLOAD(cb->nlh, 0) >= sizeof(struct rtmsg) &&
 493                 ((struct rtmsg *)nlmsg_data(cb->nlh))->rtm_flags&RTM_F_CLONED)
 494                         return dn_cache_dump(skb, cb);
 495
 496         s_h = cb->args[0];
 497         s_e = cb->args[1];
 498
 499         for (h = s_h; h < DN_FIB_TABLE_HASHSZ; h++, s_h = 0) {
 500                 e = 0;
 501                 hlist_for_each_entry(tb, node, &dn_fib_table_hash[h], hlist) {
 502                         if (e < s_e)
 503                                 goto next;
 504                         if (dumped)
 505                                 memset(&cb->args[2], 0, sizeof(cb->args) -
 506                                                  2 * sizeof(cb->args[0]));
 507                         if (tb->dump(tb, skb, cb) < 0)
 508                                 goto out;
 509                         dumped = 1;
 510 next:
 511                         e++;
 512                 }
 513         }
 514 out:
 515         cb->args[1] = e;
 516         cb->args[0] = h;
 517
 518         return skb->len;
 519 }
 520
 521 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)
 522 {
 523         struct dn_hash *table = (struct dn_hash *)tb->data;
 524         struct dn_fib_node *new_f, *f, **fp, **del_fp;
 525         struct dn_zone *dz;
 526         struct dn_fib_info *fi;
 527         int z = r->rtm_dst_len;
 528         int type = r->rtm_type;
 529         dn_fib_key_t key;
 530         int err;
 531
 532         if (z > 16)
 533                 return -EINVAL;
 534
 535         dz = table->dh_zones[z];
 536         if (!dz && !(dz = dn_new_zone(table, z)))
 537                 return -ENOBUFS;
 538
 539         dz_key_0(key);
 540         if (rta->rta_dst) {
 541                 __le16 dst;
 542                 memcpy(&dst, rta->rta_dst, 2);
 543                 if (dst & ~DZ_MASK(dz))
 544                         return -EINVAL;
 545                 key = dz_key(dst, dz);
 546         }
 547
 548         if ((fi = dn_fib_create_info(r, rta, n, &err)) == NULL)
 549                 return err;
 550
 551         if (dz->dz_nent > (dz->dz_divisor << 2) &&
 552                         dz->dz_divisor > DN_MAX_DIVISOR &&
 553                         (z==16 || (1<<z) > dz->dz_divisor))
 554                 dn_rehash_zone(dz);
 555
 556         fp = dn_chain_p(key, dz);
 557
 558         DN_FIB_SCAN(f, fp) {
 559                 if (dn_key_leq(key, f->fn_key))
 560                         break;
 561         }
 562
 563         del_fp = NULL;
 564
 565         if (f && (f->fn_state & DN_S_ZOMBIE) &&
 566                         dn_key_eq(f->fn_key, key)) {
 567                 del_fp = fp;
 568                 fp = &f->fn_next;
 569                 f = *fp;
 570                 goto create;
 571         }
 572
 573         DN_FIB_SCAN_KEY(f, fp, key) {
 574                 if (fi->fib_priority <= DN_FIB_INFO(f)->fib_priority)
 575                         break;
 576         }
 577
 578         if (f && dn_key_eq(f->fn_key, key) &&
 579                         fi->fib_priority == DN_FIB_INFO(f)->fib_priority) {
 580                 struct dn_fib_node **ins_fp;
 581
 582                 err = -EEXIST;
 583                 if (n->nlmsg_flags & NLM_F_EXCL)
 584                         goto out;
 585
 586                 if (n->nlmsg_flags & NLM_F_REPLACE) {
 587                         del_fp = fp;
 588                         fp = &f->fn_next;
 589                         f = *fp;
 590                         goto replace;
 591                 }
 592
 593                 ins_fp = fp;
 594                 err = -EEXIST;
 595
 596                 DN_FIB_SCAN_KEY(f, fp, key) {
 597                         if (fi->fib_priority != DN_FIB_INFO(f)->fib_priority)
 598                                 break;
 599                         if (f->fn_type == type &&
 600                             f->fn_scope == r->rtm_scope &&
 601                             DN_FIB_INFO(f) == fi)
 602                                 goto out;
 603                 }
 604
 605                 if (!(n->nlmsg_flags & NLM_F_APPEND)) {
 606                         fp = ins_fp;
 607                         f = *fp;
 608                 }
 609         }
 610
 611 create:
 612         err = -ENOENT;
 613         if (!(n->nlmsg_flags & NLM_F_CREATE))
 614                 goto out;
 615
 616 replace:
 617         err = -ENOBUFS;
 618         new_f = kmem_cache_zalloc(dn_hash_kmem, GFP_KERNEL);
 619         if (new_f == NULL)
 620                 goto out;
 621
 622         new_f->fn_key = key;
 623         new_f->fn_type = type;
 624         new_f->fn_scope = r->rtm_scope;
 625         DN_FIB_INFO(new_f) = fi;
 626
 627         new_f->fn_next = f;
 628         write_lock_bh(&dn_fib_tables_lock);
 629         *fp = new_f;
 630         write_unlock_bh(&dn_fib_tables_lock);
 631         dz->dz_nent++;
 632
 633         if (del_fp) {
 634                 f = *del_fp;
 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_ZOMBIE))
 640                         dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 641                 if (f->fn_state & DN_S_ACCESSED)
 642                         dn_rt_cache_flush(-1);
 643                 dn_free_node(f);
 644                 dz->dz_nent--;
 645         } else {
 646                 dn_rt_cache_flush(-1);
 647         }
 648
 649         dn_rtmsg_fib(RTM_NEWROUTE, new_f, z, tb->n, n, req);
 650
 651         return 0;
 652 out:
 653         dn_fib_release_info(fi);
 654         return err;
 655 }
 656
 657
 658 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)
 659 {
 660         struct dn_hash *table = (struct dn_hash*)tb->data;
 661         struct dn_fib_node **fp, **del_fp, *f;
 662         int z = r->rtm_dst_len;
 663         struct dn_zone *dz;
 664         dn_fib_key_t key;
 665         int matched;
 666
 667
 668         if (z > 16)
 669                 return -EINVAL;
 670
 671         if ((dz = table->dh_zones[z]) == NULL)
 672                 return -ESRCH;
 673
 674         dz_key_0(key);
 675         if (rta->rta_dst) {
 676                 __le16 dst;
 677                 memcpy(&dst, rta->rta_dst, 2);
 678                 if (dst & ~DZ_MASK(dz))
 679                         return -EINVAL;
 680                 key = dz_key(dst, dz);
 681         }
 682
 683         fp = dn_chain_p(key, dz);
 684
 685         DN_FIB_SCAN(f, fp) {
 686                 if (dn_key_eq(f->fn_key, key))
 687                         break;
 688                 if (dn_key_leq(key, f->fn_key))
 689                         return -ESRCH;
 690         }
 691
 692         matched = 0;
 693         del_fp = NULL;
 694         DN_FIB_SCAN_KEY(f, fp, key) {
 695                 struct dn_fib_info *fi = DN_FIB_INFO(f);
 696
 697                 if (f->fn_state & DN_S_ZOMBIE)
 698                         return -ESRCH;
 699
 700                 matched++;
 701
 702                 if (del_fp == NULL &&
 703                                 (!r->rtm_type || f->fn_type == r->rtm_type) &&
 704                                 (r->rtm_scope == RT_SCOPE_NOWHERE || f->fn_scope == r->rtm_scope) &&
 705                                 (!r->rtm_protocol ||
 706                                         fi->fib_protocol == r->rtm_protocol) &&
 707                                 dn_fib_nh_match(r, n, rta, fi) == 0)
 708                         del_fp = fp;
 709         }
 710
 711         if (del_fp) {
 712                 f = *del_fp;
 713                 dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 714
 715                 if (matched != 1) {
 716                         write_lock_bh(&dn_fib_tables_lock);
 717                         *del_fp = f->fn_next;
 718                         write_unlock_bh(&dn_fib_tables_lock);
 719
 720                         if (f->fn_state & DN_S_ACCESSED)
 721                                 dn_rt_cache_flush(-1);
 722                         dn_free_node(f);
 723                         dz->dz_nent--;
 724                 } else {
 725                         f->fn_state |= DN_S_ZOMBIE;
 726                         if (f->fn_state & DN_S_ACCESSED) {
 727                                 f->fn_state &= ~DN_S_ACCESSED;
 728                                 dn_rt_cache_flush(-1);
 729                         }
 730                         if (++dn_fib_hash_zombies > 128)
 731                                 dn_fib_flush();
 732                 }
 733
 734                 return 0;
 735         }
 736
 737         return -ESRCH;
 738 }
 739
 740 static inline int dn_flush_list(struct dn_fib_node **fp, int z, struct dn_hash *table)
 741 {
 742         int found = 0;
 743         struct dn_fib_node *f;
 744
 745         while((f = *fp) != NULL) {
 746                 struct dn_fib_info *fi = DN_FIB_INFO(f);
 747
 748                 if (fi && ((f->fn_state & DN_S_ZOMBIE) || (fi->fib_flags & RTNH_F_DEAD))) {
 749                         write_lock_bh(&dn_fib_tables_lock);
 750                         *fp = f->fn_next;
 751                         write_unlock_bh(&dn_fib_tables_lock);
 752
 753                         dn_free_node(f);
 754                         found++;
 755                         continue;
 756                 }
 757                 fp = &f->fn_next;
 758         }
 759
 760         return found;
 761 }
 762
 763 static int dn_fib_table_flush(struct dn_fib_table *tb)
 764 {
 765         struct dn_hash *table = (struct dn_hash *)tb->data;
 766         struct dn_zone *dz;
 767         int found = 0;
 768
 769         dn_fib_hash_zombies = 0;
 770         for(dz = table->dh_zone_list; dz; dz = dz->dz_next) {
 771                 int i;
 772                 int tmp = 0;
 773                 for(i = dz->dz_divisor-1; i >= 0; i--)
 774                         tmp += dn_flush_list(&dz->dz_hash[i], dz->dz_order, table);
 775                 dz->dz_nent -= tmp;
 776                 found += tmp;
 777         }
 778
 779         return found;
 780 }
 781
 782 static int dn_fib_table_lookup(struct dn_fib_table *tb, const struct flowidn *flp, struct dn_fib_res *res)
 783 {
 784         int err;
 785         struct dn_zone *dz;
 786         struct dn_hash *t = (struct dn_hash *)tb->data;
 787
 788         read_lock(&dn_fib_tables_lock);
 789         for(dz = t->dh_zone_list; dz; dz = dz->dz_next) {
 790                 struct dn_fib_node *f;
 791                 dn_fib_key_t k = dz_key(flp->daddr, dz);
 792
 793                 for(f = dz_chain(k, dz); f; f = f->fn_next) {
 794                         if (!dn_key_eq(k, f->fn_key)) {
 795                                 if (dn_key_leq(k, f->fn_key))
 796                                         break;
 797                                 else
 798                                         continue;
 799                         }
 800
 801                         f->fn_state |= DN_S_ACCESSED;
 802
 803                         if (f->fn_state&DN_S_ZOMBIE)
 804                                 continue;
 805
 806                         if (f->fn_scope < flp->flowidn_scope)
 807                                 continue;
 808
 809                         err = dn_fib_semantic_match(f->fn_type, DN_FIB_INFO(f), flp, res);
 810
 811                         if (err == 0) {
 812                                 res->type = f->fn_type;
 813                                 res->scope = f->fn_scope;
 814                                 res->prefixlen = dz->dz_order;
 815                                 goto out;
 816                         }
 817                         if (err < 0)
 818                                 goto out;
 819                 }
 820         }
 821         err = 1;
 822 out:
 823         read_unlock(&dn_fib_tables_lock);
 824         return err;
 825 }
 826
 827
 828 struct dn_fib_table *dn_fib_get_table(u32 n, int create)
 829 {
 830         struct dn_fib_table *t;
 831         struct hlist_node *node;
 832         unsigned int h;
 833
 834         if (n < RT_TABLE_MIN)
 835                 return NULL;
 836
 837         if (n > RT_TABLE_MAX)
 838                 return NULL;
 839
 840         h = n & (DN_FIB_TABLE_HASHSZ - 1);
 841         rcu_read_lock();
 842         hlist_for_each_entry_rcu(t, node, &dn_fib_table_hash[h], hlist) {
 843                 if (t->n == n) {
 844                         rcu_read_unlock();
 845                         return t;
 846                 }
 847         }
 848         rcu_read_unlock();
 849
 850         if (!create)
 851                 return NULL;
 852
 853         if (in_interrupt()) {
 854                 net_dbg_ratelimited("DECnet: BUG! Attempt to create routing table from interrupt\n");
 855                 return NULL;
 856         }
 857
 858         t = kzalloc(sizeof(struct dn_fib_table) + sizeof(struct dn_hash),
 859                     GFP_KERNEL);
 860         if (t == NULL)
 861                 return NULL;
 862
 863         t->n = n;
 864         t->insert = dn_fib_table_insert;
 865         t->delete = dn_fib_table_delete;
 866         t->lookup = dn_fib_table_lookup;
 867         t->flush  = dn_fib_table_flush;
 868         t->dump = dn_fib_table_dump;
 869         hlist_add_head_rcu(&t->hlist, &dn_fib_table_hash[h]);
 870
 871         return t;
 872 }
 873
 874 struct dn_fib_table *dn_fib_empty_table(void)
 875 {
 876         u32 id;
 877
 878         for(id = RT_TABLE_MIN; id <= RT_TABLE_MAX; id++)
 879                 if (dn_fib_get_table(id, 0) == NULL)
 880                         return dn_fib_get_table(id, 1);
 881         return NULL;
 882 }
 883
 884 void dn_fib_flush(void)
 885 {
 886         int flushed = 0;
 887         struct dn_fib_table *tb;
 888         struct hlist_node *node;
 889         unsigned int h;
 890
 891         for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
 892                 hlist_for_each_entry(tb, node, &dn_fib_table_hash[h], hlist)
 893                         flushed += tb->flush(tb);
 894         }
 895
 896         if (flushed)
 897                 dn_rt_cache_flush(-1);
 898 }
 899
 900 void __init dn_fib_table_init(void)
 901 {
 902         dn_hash_kmem = kmem_cache_create("dn_fib_info_cache",
 903                                         sizeof(struct dn_fib_info),
 904                                         0, SLAB_HWCACHE_ALIGN,
 905                                         NULL);
 906 }
 907
 908 void __exit dn_fib_table_cleanup(void)
 909 {
 910         struct dn_fib_table *t;
 911         struct hlist_node *node, *next;
 912         unsigned int h;
 913
 914         write_lock(&dn_fib_tables_lock);
 915         for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
 916                 hlist_for_each_entry_safe(t, node, next, &dn_fib_table_hash[h],
 917                                           hlist) {
 918                         hlist_del(&t->hlist);
 919                         kfree(t);
 920                 }
 921         }
 922         write_unlock(&dn_fib_tables_lock);
 923 }