kernel/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/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 <linux/atomic.h>
  28 #include <asm/uaccess.h>
  29 #include <linux/route.h> /* RTF_xxx */
  30 #include <net/neighbour.h>
  31 #include <net/netlink.h>
  32 #include <net/tcp.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 nlattr *attrs[], struct dn_fib_info *fi)
 228 {
 229         struct rtnexthop *nhp;
 230         int nhlen;
 231
 232         if (attrs[RTA_PRIORITY] &&
 233             nla_get_u32(attrs[RTA_PRIORITY]) != fi->fib_priority)
 234                 return 1;
 235
 236         if (attrs[RTA_OIF] || attrs[RTA_GATEWAY]) {
 237                 if ((!attrs[RTA_OIF] || nla_get_u32(attrs[RTA_OIF]) == fi->fib_nh->nh_oif) &&
 238                     (!attrs[RTA_GATEWAY]  || nla_get_le16(attrs[RTA_GATEWAY]) != fi->fib_nh->nh_gw))
 239                         return 0;
 240                 return 1;
 241         }
 242
 243         if (!attrs[RTA_MULTIPATH])
 244                 return 0;
 245
 246         nhp = nla_data(attrs[RTA_MULTIPATH]);
 247         nhlen = nla_len(attrs[RTA_MULTIPATH]);
 248
 249         for_nexthops(fi) {
 250                 int attrlen = nhlen - sizeof(struct rtnexthop);
 251                 __le16 gw;
 252
 253                 if (attrlen < 0 || (nhlen -= nhp->rtnh_len) < 0)
 254                         return -EINVAL;
 255                 if (nhp->rtnh_ifindex && nhp->rtnh_ifindex != nh->nh_oif)
 256                         return 1;
 257                 if (attrlen) {
 258                         struct nlattr *gw_attr;
 259
 260                         gw_attr = nla_find((struct nlattr *) (nhp + 1), attrlen, RTA_GATEWAY);
 261                         gw = gw_attr ? nla_get_le16(gw_attr) : 0;
 262
 263                         if (gw && gw != nh->nh_gw)
 264                                 return 1;
 265                 }
 266                 nhp = RTNH_NEXT(nhp);
 267         } endfor_nexthops(fi);
 268
 269         return 0;
 270 }
 271
 272 static inline size_t dn_fib_nlmsg_size(struct dn_fib_info *fi)
 273 {
 274         size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg))
 275                          + nla_total_size(4) /* RTA_TABLE */
 276                          + nla_total_size(2) /* RTA_DST */
 277                          + nla_total_size(4) /* RTA_PRIORITY */
 278                          + nla_total_size(TCP_CA_NAME_MAX); /* RTAX_CC_ALGO */
 279
 280         /* space for nested metrics */
 281         payload += nla_total_size((RTAX_MAX * nla_total_size(4)));
 282
 283         if (fi->fib_nhs) {
 284                 /* Also handles the special case fib_nhs == 1 */
 285
 286                 /* each nexthop is packed in an attribute */
 287                 size_t nhsize = nla_total_size(sizeof(struct rtnexthop));
 288
 289                 /* may contain a gateway attribute */
 290                 nhsize += nla_total_size(4);
 291
 292                 /* all nexthops are packed in a nested attribute */
 293                 payload += nla_total_size(fi->fib_nhs * nhsize);
 294         }
 295
 296         return payload;
 297 }
 298
 299 static int dn_fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event,
 300                         u32 tb_id, u8 type, u8 scope, void *dst, int dst_len,
 301                         struct dn_fib_info *fi, unsigned int flags)
 302 {
 303         struct rtmsg *rtm;
 304         struct nlmsghdr *nlh;
 305
 306         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags);
 307         if (!nlh)
 308                 return -EMSGSIZE;
 309
 310         rtm = nlmsg_data(nlh);
 311         rtm->rtm_family = AF_DECnet;
 312         rtm->rtm_dst_len = dst_len;
 313         rtm->rtm_src_len = 0;
 314         rtm->rtm_tos = 0;
 315         rtm->rtm_table = tb_id;
 316         rtm->rtm_flags = fi->fib_flags;
 317         rtm->rtm_scope = scope;
 318         rtm->rtm_type  = type;
 319         rtm->rtm_protocol = fi->fib_protocol;
 320
 321         if (nla_put_u32(skb, RTA_TABLE, tb_id) < 0)
 322                 goto errout;
 323
 324         if (rtm->rtm_dst_len &&
 325             nla_put(skb, RTA_DST, 2, dst) < 0)
 326                 goto errout;
 327
 328         if (fi->fib_priority &&
 329             nla_put_u32(skb, RTA_PRIORITY, fi->fib_priority) < 0)
 330                 goto errout;
 331
 332         if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0)
 333                 goto errout;
 334
 335         if (fi->fib_nhs == 1) {
 336                 if (fi->fib_nh->nh_gw &&
 337                     nla_put_le16(skb, RTA_GATEWAY, fi->fib_nh->nh_gw) < 0)
 338                         goto errout;
 339
 340                 if (fi->fib_nh->nh_oif &&
 341                     nla_put_u32(skb, RTA_OIF, fi->fib_nh->nh_oif) < 0)
 342                         goto errout;
 343         }
 344
 345         if (fi->fib_nhs > 1) {
 346                 struct rtnexthop *nhp;
 347                 struct nlattr *mp_head;
 348
 349                 if (!(mp_head = nla_nest_start(skb, RTA_MULTIPATH)))
 350                         goto errout;
 351
 352                 for_nexthops(fi) {
 353                         if (!(nhp = nla_reserve_nohdr(skb, sizeof(*nhp))))
 354                                 goto errout;
 355
 356                         nhp->rtnh_flags = nh->nh_flags & 0xFF;
 357                         nhp->rtnh_hops = nh->nh_weight - 1;
 358                         nhp->rtnh_ifindex = nh->nh_oif;
 359
 360                         if (nh->nh_gw &&
 361                             nla_put_le16(skb, RTA_GATEWAY, nh->nh_gw) < 0)
 362                                 goto errout;
 363
 364                         nhp->rtnh_len = skb_tail_pointer(skb) - (unsigned char *)nhp;
 365                 } endfor_nexthops(fi);
 366
 367                 nla_nest_end(skb, mp_head);
 368         }
 369
 370         nlmsg_end(skb, nlh);
 371         return 0;
 372
 373 errout:
 374         nlmsg_cancel(skb, nlh);
 375         return -EMSGSIZE;
 376 }
 377
 378
 379 static void dn_rtmsg_fib(int event, struct dn_fib_node *f, int z, u32 tb_id,
 380                         struct nlmsghdr *nlh, struct netlink_skb_parms *req)
 381 {
 382         struct sk_buff *skb;
 383         u32 portid = req ? req->portid : 0;
 384         int err = -ENOBUFS;
 385
 386         skb = nlmsg_new(dn_fib_nlmsg_size(DN_FIB_INFO(f)), GFP_KERNEL);
 387         if (skb == NULL)
 388                 goto errout;
 389
 390         err = dn_fib_dump_info(skb, portid, nlh->nlmsg_seq, event, tb_id,
 391                                f->fn_type, f->fn_scope, &f->fn_key, z,
 392                                DN_FIB_INFO(f), 0);
 393         if (err < 0) {
 394                 /* -EMSGSIZE implies BUG in dn_fib_nlmsg_size() */
 395                 WARN_ON(err == -EMSGSIZE);
 396                 kfree_skb(skb);
 397                 goto errout;
 398         }
 399         rtnl_notify(skb, &init_net, portid, RTNLGRP_DECnet_ROUTE, nlh, GFP_KERNEL);
 400         return;
 401 errout:
 402         if (err < 0)
 403                 rtnl_set_sk_err(&init_net, RTNLGRP_DECnet_ROUTE, err);
 404 }
 405
 406 static __inline__ int dn_hash_dump_bucket(struct sk_buff *skb,
 407                                 struct netlink_callback *cb,
 408                                 struct dn_fib_table *tb,
 409                                 struct dn_zone *dz,
 410                                 struct dn_fib_node *f)
 411 {
 412         int i, s_i;
 413
 414         s_i = cb->args[4];
 415         for(i = 0; f; i++, f = f->fn_next) {
 416                 if (i < s_i)
 417                         continue;
 418                 if (f->fn_state & DN_S_ZOMBIE)
 419                         continue;
 420                 if (dn_fib_dump_info(skb, NETLINK_CB(cb->skb).portid,
 421                                 cb->nlh->nlmsg_seq,
 422                                 RTM_NEWROUTE,
 423                                 tb->n,
 424                                 (f->fn_state & DN_S_ZOMBIE) ? 0 : f->fn_type,
 425                                 f->fn_scope, &f->fn_key, dz->dz_order,
 426                                 f->fn_info, NLM_F_MULTI) < 0) {
 427                         cb->args[4] = i;
 428                         return -1;
 429                 }
 430         }
 431         cb->args[4] = i;
 432         return skb->len;
 433 }
 434
 435 static __inline__ int dn_hash_dump_zone(struct sk_buff *skb,
 436                                 struct netlink_callback *cb,
 437                                 struct dn_fib_table *tb,
 438                                 struct dn_zone *dz)
 439 {
 440         int h, s_h;
 441
 442         s_h = cb->args[3];
 443         for(h = 0; h < dz->dz_divisor; h++) {
 444                 if (h < s_h)
 445                         continue;
 446                 if (h > s_h)
 447                         memset(&cb->args[4], 0, sizeof(cb->args) - 4*sizeof(cb->args[0]));
 448                 if (dz->dz_hash == NULL || dz->dz_hash[h] == NULL)
 449                         continue;
 450                 if (dn_hash_dump_bucket(skb, cb, tb, dz, dz->dz_hash[h]) < 0) {
 451                         cb->args[3] = h;
 452                         return -1;
 453                 }
 454         }
 455         cb->args[3] = h;
 456         return skb->len;
 457 }
 458
 459 static int dn_fib_table_dump(struct dn_fib_table *tb, struct sk_buff *skb,
 460                                 struct netlink_callback *cb)
 461 {
 462         int m, s_m;
 463         struct dn_zone *dz;
 464         struct dn_hash *table = (struct dn_hash *)tb->data;
 465
 466         s_m = cb->args[2];
 467         read_lock(&dn_fib_tables_lock);
 468         for(dz = table->dh_zone_list, m = 0; dz; dz = dz->dz_next, m++) {
 469                 if (m < s_m)
 470                         continue;
 471                 if (m > s_m)
 472                         memset(&cb->args[3], 0, sizeof(cb->args) - 3*sizeof(cb->args[0]));
 473
 474                 if (dn_hash_dump_zone(skb, cb, tb, dz) < 0) {
 475                         cb->args[2] = m;
 476                         read_unlock(&dn_fib_tables_lock);
 477                         return -1;
 478                 }
 479         }
 480         read_unlock(&dn_fib_tables_lock);
 481         cb->args[2] = m;
 482
 483         return skb->len;
 484 }
 485
 486 int dn_fib_dump(struct sk_buff *skb, struct netlink_callback *cb)
 487 {
 488         struct net *net = sock_net(skb->sk);
 489         unsigned int h, s_h;
 490         unsigned int e = 0, s_e;
 491         struct dn_fib_table *tb;
 492         int dumped = 0;
 493
 494         if (!net_eq(net, &init_net))
 495                 return 0;
 496
 497         if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
 498                 ((struct rtmsg *)nlmsg_data(cb->nlh))->rtm_flags&RTM_F_CLONED)
 499                         return dn_cache_dump(skb, cb);
 500
 501         s_h = cb->args[0];
 502         s_e = cb->args[1];
 503
 504         for (h = s_h; h < DN_FIB_TABLE_HASHSZ; h++, s_h = 0) {
 505                 e = 0;
 506                 hlist_for_each_entry(tb, &dn_fib_table_hash[h], hlist) {
 507                         if (e < s_e)
 508                                 goto next;
 509                         if (dumped)
 510                                 memset(&cb->args[2], 0, sizeof(cb->args) -
 511                                                  2 * sizeof(cb->args[0]));
 512                         if (tb->dump(tb, skb, cb) < 0)
 513                                 goto out;
 514                         dumped = 1;
 515 next:
 516                         e++;
 517                 }
 518         }
 519 out:
 520         cb->args[1] = e;
 521         cb->args[0] = h;
 522
 523         return skb->len;
 524 }
 525
 526 static int dn_fib_table_insert(struct dn_fib_table *tb, struct rtmsg *r, struct nlattr *attrs[],
 527                                struct nlmsghdr *n, struct netlink_skb_parms *req)
 528 {
 529         struct dn_hash *table = (struct dn_hash *)tb->data;
 530         struct dn_fib_node *new_f, *f, **fp, **del_fp;
 531         struct dn_zone *dz;
 532         struct dn_fib_info *fi;
 533         int z = r->rtm_dst_len;
 534         int type = r->rtm_type;
 535         dn_fib_key_t key;
 536         int err;
 537
 538         if (z > 16)
 539                 return -EINVAL;
 540
 541         dz = table->dh_zones[z];
 542         if (!dz && !(dz = dn_new_zone(table, z)))
 543                 return -ENOBUFS;
 544
 545         dz_key_0(key);
 546         if (attrs[RTA_DST]) {
 547                 __le16 dst = nla_get_le16(attrs[RTA_DST]);
 548                 if (dst & ~DZ_MASK(dz))
 549                         return -EINVAL;
 550                 key = dz_key(dst, dz);
 551         }
 552
 553         if ((fi = dn_fib_create_info(r, attrs, n, &err)) == NULL)
 554                 return err;
 555
 556         if (dz->dz_nent > (dz->dz_divisor << 2) &&
 557                         dz->dz_divisor > DN_MAX_DIVISOR &&
 558                         (z==16 || (1<<z) > dz->dz_divisor))
 559                 dn_rehash_zone(dz);
 560
 561         fp = dn_chain_p(key, dz);
 562
 563         DN_FIB_SCAN(f, fp) {
 564                 if (dn_key_leq(key, f->fn_key))
 565                         break;
 566         }
 567
 568         del_fp = NULL;
 569
 570         if (f && (f->fn_state & DN_S_ZOMBIE) &&
 571                         dn_key_eq(f->fn_key, key)) {
 572                 del_fp = fp;
 573                 fp = &f->fn_next;
 574                 f = *fp;
 575                 goto create;
 576         }
 577
 578         DN_FIB_SCAN_KEY(f, fp, key) {
 579                 if (fi->fib_priority <= DN_FIB_INFO(f)->fib_priority)
 580                         break;
 581         }
 582
 583         if (f && dn_key_eq(f->fn_key, key) &&
 584                         fi->fib_priority == DN_FIB_INFO(f)->fib_priority) {
 585                 struct dn_fib_node **ins_fp;
 586
 587                 err = -EEXIST;
 588                 if (n->nlmsg_flags & NLM_F_EXCL)
 589                         goto out;
 590
 591                 if (n->nlmsg_flags & NLM_F_REPLACE) {
 592                         del_fp = fp;
 593                         fp = &f->fn_next;
 594                         f = *fp;
 595                         goto replace;
 596                 }
 597
 598                 ins_fp = fp;
 599                 err = -EEXIST;
 600
 601                 DN_FIB_SCAN_KEY(f, fp, key) {
 602                         if (fi->fib_priority != DN_FIB_INFO(f)->fib_priority)
 603                                 break;
 604                         if (f->fn_type == type &&
 605                             f->fn_scope == r->rtm_scope &&
 606                             DN_FIB_INFO(f) == fi)
 607                                 goto out;
 608                 }
 609
 610                 if (!(n->nlmsg_flags & NLM_F_APPEND)) {
 611                         fp = ins_fp;
 612                         f = *fp;
 613                 }
 614         }
 615
 616 create:
 617         err = -ENOENT;
 618         if (!(n->nlmsg_flags & NLM_F_CREATE))
 619                 goto out;
 620
 621 replace:
 622         err = -ENOBUFS;
 623         new_f = kmem_cache_zalloc(dn_hash_kmem, GFP_KERNEL);
 624         if (new_f == NULL)
 625                 goto out;
 626
 627         new_f->fn_key = key;
 628         new_f->fn_type = type;
 629         new_f->fn_scope = r->rtm_scope;
 630         DN_FIB_INFO(new_f) = fi;
 631
 632         new_f->fn_next = f;
 633         write_lock_bh(&dn_fib_tables_lock);
 634         *fp = new_f;
 635         write_unlock_bh(&dn_fib_tables_lock);
 636         dz->dz_nent++;
 637
 638         if (del_fp) {
 639                 f = *del_fp;
 640                 write_lock_bh(&dn_fib_tables_lock);
 641                 *del_fp = f->fn_next;
 642                 write_unlock_bh(&dn_fib_tables_lock);
 643
 644                 if (!(f->fn_state & DN_S_ZOMBIE))
 645                         dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 646                 if (f->fn_state & DN_S_ACCESSED)
 647                         dn_rt_cache_flush(-1);
 648                 dn_free_node(f);
 649                 dz->dz_nent--;
 650         } else {
 651                 dn_rt_cache_flush(-1);
 652         }
 653
 654         dn_rtmsg_fib(RTM_NEWROUTE, new_f, z, tb->n, n, req);
 655
 656         return 0;
 657 out:
 658         dn_fib_release_info(fi);
 659         return err;
 660 }
 661
 662
 663 static int dn_fib_table_delete(struct dn_fib_table *tb, struct rtmsg *r, struct nlattr *attrs[],
 664                                struct nlmsghdr *n, struct netlink_skb_parms *req)
 665 {
 666         struct dn_hash *table = (struct dn_hash*)tb->data;
 667         struct dn_fib_node **fp, **del_fp, *f;
 668         int z = r->rtm_dst_len;
 669         struct dn_zone *dz;
 670         dn_fib_key_t key;
 671         int matched;
 672
 673
 674         if (z > 16)
 675                 return -EINVAL;
 676
 677         if ((dz = table->dh_zones[z]) == NULL)
 678                 return -ESRCH;
 679
 680         dz_key_0(key);
 681         if (attrs[RTA_DST]) {
 682                 __le16 dst = nla_get_le16(attrs[RTA_DST]);
 683                 if (dst & ~DZ_MASK(dz))
 684                         return -EINVAL;
 685                 key = dz_key(dst, dz);
 686         }
 687
 688         fp = dn_chain_p(key, dz);
 689
 690         DN_FIB_SCAN(f, fp) {
 691                 if (dn_key_eq(f->fn_key, key))
 692                         break;
 693                 if (dn_key_leq(key, f->fn_key))
 694                         return -ESRCH;
 695         }
 696
 697         matched = 0;
 698         del_fp = NULL;
 699         DN_FIB_SCAN_KEY(f, fp, key) {
 700                 struct dn_fib_info *fi = DN_FIB_INFO(f);
 701
 702                 if (f->fn_state & DN_S_ZOMBIE)
 703                         return -ESRCH;
 704
 705                 matched++;
 706
 707                 if (del_fp == NULL &&
 708                                 (!r->rtm_type || f->fn_type == r->rtm_type) &&
 709                                 (r->rtm_scope == RT_SCOPE_NOWHERE || f->fn_scope == r->rtm_scope) &&
 710                                 (!r->rtm_protocol ||
 711                                         fi->fib_protocol == r->rtm_protocol) &&
 712                                 dn_fib_nh_match(r, n, attrs, fi) == 0)
 713                         del_fp = fp;
 714         }
 715
 716         if (del_fp) {
 717                 f = *del_fp;
 718                 dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 719
 720                 if (matched != 1) {
 721                         write_lock_bh(&dn_fib_tables_lock);
 722                         *del_fp = f->fn_next;
 723                         write_unlock_bh(&dn_fib_tables_lock);
 724
 725                         if (f->fn_state & DN_S_ACCESSED)
 726                                 dn_rt_cache_flush(-1);
 727                         dn_free_node(f);
 728                         dz->dz_nent--;
 729                 } else {
 730                         f->fn_state |= DN_S_ZOMBIE;
 731                         if (f->fn_state & DN_S_ACCESSED) {
 732                                 f->fn_state &= ~DN_S_ACCESSED;
 733                                 dn_rt_cache_flush(-1);
 734                         }
 735                         if (++dn_fib_hash_zombies > 128)
 736                                 dn_fib_flush();
 737                 }
 738
 739                 return 0;
 740         }
 741
 742         return -ESRCH;
 743 }
 744
 745 static inline int dn_flush_list(struct dn_fib_node **fp, int z, struct dn_hash *table)
 746 {
 747         int found = 0;
 748         struct dn_fib_node *f;
 749
 750         while((f = *fp) != NULL) {
 751                 struct dn_fib_info *fi = DN_FIB_INFO(f);
 752
 753                 if (fi && ((f->fn_state & DN_S_ZOMBIE) || (fi->fib_flags & RTNH_F_DEAD))) {
 754                         write_lock_bh(&dn_fib_tables_lock);
 755                         *fp = f->fn_next;
 756                         write_unlock_bh(&dn_fib_tables_lock);
 757
 758                         dn_free_node(f);
 759                         found++;
 760                         continue;
 761                 }
 762                 fp = &f->fn_next;
 763         }
 764
 765         return found;
 766 }
 767
 768 static int dn_fib_table_flush(struct dn_fib_table *tb)
 769 {
 770         struct dn_hash *table = (struct dn_hash *)tb->data;
 771         struct dn_zone *dz;
 772         int found = 0;
 773
 774         dn_fib_hash_zombies = 0;
 775         for(dz = table->dh_zone_list; dz; dz = dz->dz_next) {
 776                 int i;
 777                 int tmp = 0;
 778                 for(i = dz->dz_divisor-1; i >= 0; i--)
 779                         tmp += dn_flush_list(&dz->dz_hash[i], dz->dz_order, table);
 780                 dz->dz_nent -= tmp;
 781                 found += tmp;
 782         }
 783
 784         return found;
 785 }
 786
 787 static int dn_fib_table_lookup(struct dn_fib_table *tb, const struct flowidn *flp, struct dn_fib_res *res)
 788 {
 789         int err;
 790         struct dn_zone *dz;
 791         struct dn_hash *t = (struct dn_hash *)tb->data;
 792
 793         read_lock(&dn_fib_tables_lock);
 794         for(dz = t->dh_zone_list; dz; dz = dz->dz_next) {
 795                 struct dn_fib_node *f;
 796                 dn_fib_key_t k = dz_key(flp->daddr, dz);
 797
 798                 for(f = dz_chain(k, dz); f; f = f->fn_next) {
 799                         if (!dn_key_eq(k, f->fn_key)) {
 800                                 if (dn_key_leq(k, f->fn_key))
 801                                         break;
 802                                 else
 803                                         continue;
 804                         }
 805
 806                         f->fn_state |= DN_S_ACCESSED;
 807
 808                         if (f->fn_state&DN_S_ZOMBIE)
 809                                 continue;
 810
 811                         if (f->fn_scope < flp->flowidn_scope)
 812                                 continue;
 813
 814                         err = dn_fib_semantic_match(f->fn_type, DN_FIB_INFO(f), flp, res);
 815
 816                         if (err == 0) {
 817                                 res->type = f->fn_type;
 818                                 res->scope = f->fn_scope;
 819                                 res->prefixlen = dz->dz_order;
 820                                 goto out;
 821                         }
 822                         if (err < 0)
 823                                 goto out;
 824                 }
 825         }
 826         err = 1;
 827 out:
 828         read_unlock(&dn_fib_tables_lock);
 829         return err;
 830 }
 831
 832
 833 struct dn_fib_table *dn_fib_get_table(u32 n, int create)
 834 {
 835         struct dn_fib_table *t;
 836         unsigned int h;
 837
 838         if (n < RT_TABLE_MIN)
 839                 return NULL;
 840
 841         if (n > RT_TABLE_MAX)
 842                 return NULL;
 843
 844         h = n & (DN_FIB_TABLE_HASHSZ - 1);
 845         rcu_read_lock();
 846         hlist_for_each_entry_rcu(t, &dn_fib_table_hash[h], hlist) {
 847                 if (t->n == n) {
 848                         rcu_read_unlock();
 849                         return t;
 850                 }
 851         }
 852         rcu_read_unlock();
 853
 854         if (!create)
 855                 return NULL;
 856
 857         if (in_interrupt()) {
 858                 net_dbg_ratelimited("DECnet: BUG! Attempt to create routing table from interrupt\n");
 859                 return NULL;
 860         }
 861
 862         t = kzalloc(sizeof(struct dn_fib_table) + sizeof(struct dn_hash),
 863                     GFP_KERNEL);
 864         if (t == NULL)
 865                 return NULL;
 866
 867         t->n = n;
 868         t->insert = dn_fib_table_insert;
 869         t->delete = dn_fib_table_delete;
 870         t->lookup = dn_fib_table_lookup;
 871         t->flush  = dn_fib_table_flush;
 872         t->dump = dn_fib_table_dump;
 873         hlist_add_head_rcu(&t->hlist, &dn_fib_table_hash[h]);
 874
 875         return t;
 876 }
 877
 878 struct dn_fib_table *dn_fib_empty_table(void)
 879 {
 880         u32 id;
 881
 882         for(id = RT_TABLE_MIN; id <= RT_TABLE_MAX; id++)
 883                 if (dn_fib_get_table(id, 0) == NULL)
 884                         return dn_fib_get_table(id, 1);
 885         return NULL;
 886 }
 887
 888 void dn_fib_flush(void)
 889 {
 890         int flushed = 0;
 891         struct dn_fib_table *tb;
 892         unsigned int h;
 893
 894         for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
 895                 hlist_for_each_entry(tb, &dn_fib_table_hash[h], hlist)
 896                         flushed += tb->flush(tb);
 897         }
 898
 899         if (flushed)
 900                 dn_rt_cache_flush(-1);
 901 }
 902
 903 void __init dn_fib_table_init(void)
 904 {
 905         dn_hash_kmem = kmem_cache_create("dn_fib_info_cache",
 906                                         sizeof(struct dn_fib_info),
 907                                         0, SLAB_HWCACHE_ALIGN,
 908                                         NULL);
 909 }
 910
 911 void __exit dn_fib_table_cleanup(void)
 912 {
 913         struct dn_fib_table *t;
 914         struct hlist_node *next;
 915         unsigned int h;
 916
 917         write_lock(&dn_fib_tables_lock);
 918         for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
 919                 hlist_for_each_entry_safe(t, next, &dn_fib_table_hash[h],
 920                                           hlist) {
 921                         hlist_del(&t->hlist);
 922                         kfree(t);
 923                 }
 924         }
 925         write_unlock(&dn_fib_tables_lock);
 926 }