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/netlink.h>
  32 #include <net/dst.h>
  33 #include <net/flow.h>
  34 #include <net/fib_rules.h>
  35 #include <net/dn.h>
  36 #include <net/dn_route.h>
  37 #include <net/dn_fib.h>
  38 #include <net/dn_neigh.h>
  39 #include <net/dn_dev.h>
  40
  41 struct dn_zone
  42 {
  43         struct dn_zone          *dz_next;
  44         struct dn_fib_node      **dz_hash;
  45         int                     dz_nent;
  46         int                     dz_divisor;
  47         u32                     dz_hashmask;
  48 #define DZ_HASHMASK(dz) ((dz)->dz_hashmask)
  49         int                     dz_order;
  50         __le16                  dz_mask;
  51 #define DZ_MASK(dz)     ((dz)->dz_mask)
  52 };
  53
  54 struct dn_hash
  55 {
  56         struct dn_zone  *dh_zones[17];
  57         struct dn_zone  *dh_zone_list;
  58 };
  59
  60 #define dz_key_0(key)           ((key).datum = 0)
  61 #define dz_prefix(key,dz)       ((key).datum)
  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         int i;
 127         struct dn_fib_node *f, **fp, *next;
 128
 129         for(i = 0; i < old_divisor; i++) {
 130                 for(f = old_ht[i]; f; f = f->fn_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", old_divisor);
 157                 case 256:
 158                         new_divisor = 1024;
 159                         new_hashmask = 0x3FF;
 160                         break;
 161         }
 162
 163         ht = kcalloc(new_divisor, sizeof(struct dn_fib_node*), GFP_KERNEL);
 164         if (ht == NULL)
 165                 return;
 166
 167         write_lock_bh(&dn_fib_tables_lock);
 168         old_ht = dz->dz_hash;
 169         dz->dz_hash = ht;
 170         dz->dz_hashmask = new_hashmask;
 171         dz->dz_divisor = new_divisor;
 172         dn_rebuild_zone(dz, old_ht, old_divisor);
 173         write_unlock_bh(&dn_fib_tables_lock);
 174         kfree(old_ht);
 175 }
 176
 177 static void dn_free_node(struct dn_fib_node *f)
 178 {
 179         dn_fib_release_info(DN_FIB_INFO(f));
 180         kmem_cache_free(dn_hash_kmem, f);
 181 }
 182
 183
 184 static struct dn_zone *dn_new_zone(struct dn_hash *table, int z)
 185 {
 186         int i;
 187         struct dn_zone *dz = kzalloc(sizeof(struct dn_zone), GFP_KERNEL);
 188         if (!dz)
 189                 return NULL;
 190
 191         if (z) {
 192                 dz->dz_divisor = 16;
 193                 dz->dz_hashmask = 0x0F;
 194         } else {
 195                 dz->dz_divisor = 1;
 196                 dz->dz_hashmask = 0;
 197         }
 198
 199         dz->dz_hash = kcalloc(dz->dz_divisor, sizeof(struct dn_fib_node *), GFP_KERNEL);
 200         if (!dz->dz_hash) {
 201                 kfree(dz);
 202                 return NULL;
 203         }
 204
 205         dz->dz_order = z;
 206         dz->dz_mask = dnet_make_mask(z);
 207
 208         for(i = z + 1; i <= 16; i++)
 209                 if (table->dh_zones[i])
 210                         break;
 211
 212         write_lock_bh(&dn_fib_tables_lock);
 213         if (i>16) {
 214                 dz->dz_next = table->dh_zone_list;
 215                 table->dh_zone_list = dz;
 216         } else {
 217                 dz->dz_next = table->dh_zones[i]->dz_next;
 218                 table->dh_zones[i]->dz_next = dz;
 219         }
 220         table->dh_zones[z] = dz;
 221         write_unlock_bh(&dn_fib_tables_lock);
 222         return dz;
 223 }
 224
 225
 226 static int dn_fib_nh_match(struct rtmsg *r, struct nlmsghdr *nlh, struct dn_kern_rta *rta, struct dn_fib_info *fi)
 227 {
 228         struct rtnexthop *nhp;
 229         int nhlen;
 230
 231         if (rta->rta_priority && *rta->rta_priority != fi->fib_priority)
 232                 return 1;
 233
 234         if (rta->rta_oif || rta->rta_gw) {
 235                 if ((!rta->rta_oif || *rta->rta_oif == fi->fib_nh->nh_oif) &&
 236                     (!rta->rta_gw  || memcmp(rta->rta_gw, &fi->fib_nh->nh_gw, 2) == 0))
 237                         return 0;
 238                 return 1;
 239         }
 240
 241         if (rta->rta_mp == NULL)
 242                 return 0;
 243
 244         nhp = RTA_DATA(rta->rta_mp);
 245         nhlen = RTA_PAYLOAD(rta->rta_mp);
 246
 247         for_nexthops(fi) {
 248                 int attrlen = nhlen - sizeof(struct rtnexthop);
 249                 __le16 gw;
 250
 251                 if (attrlen < 0 || (nhlen -= nhp->rtnh_len) < 0)
 252                         return -EINVAL;
 253                 if (nhp->rtnh_ifindex && nhp->rtnh_ifindex != nh->nh_oif)
 254                         return 1;
 255                 if (attrlen) {
 256                         gw = dn_fib_get_attr16(RTNH_DATA(nhp), attrlen, RTA_GATEWAY);
 257
 258                         if (gw && gw != nh->nh_gw)
 259                                 return 1;
 260                 }
 261                 nhp = RTNH_NEXT(nhp);
 262         } endfor_nexthops(fi);
 263
 264         return 0;
 265 }
 266
 267 static inline size_t dn_fib_nlmsg_size(struct dn_fib_info *fi)
 268 {
 269         size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg))
 270                          + nla_total_size(4) /* RTA_TABLE */
 271                          + nla_total_size(2) /* RTA_DST */
 272                          + nla_total_size(4); /* RTA_PRIORITY */
 273
 274         /* space for nested metrics */
 275         payload += nla_total_size((RTAX_MAX * nla_total_size(4)));
 276
 277         if (fi->fib_nhs) {
 278                 /* Also handles the special case fib_nhs == 1 */
 279
 280                 /* each nexthop is packed in an attribute */
 281                 size_t nhsize = nla_total_size(sizeof(struct rtnexthop));
 282
 283                 /* may contain a gateway attribute */
 284                 nhsize += nla_total_size(4);
 285
 286                 /* all nexthops are packed in a nested attribute */
 287                 payload += nla_total_size(fi->fib_nhs * nhsize);
 288         }
 289
 290         return payload;
 291 }
 292
 293 static int dn_fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
 294                         u32 tb_id, u8 type, u8 scope, void *dst, int dst_len,
 295                         struct dn_fib_info *fi, unsigned int flags)
 296 {
 297         struct rtmsg *rtm;
 298         struct nlmsghdr *nlh;
 299         unsigned char *b = skb_tail_pointer(skb);
 300
 301         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*rtm), flags);
 302         rtm = NLMSG_DATA(nlh);
 303         rtm->rtm_family = AF_DECnet;
 304         rtm->rtm_dst_len = dst_len;
 305         rtm->rtm_src_len = 0;
 306         rtm->rtm_tos = 0;
 307         rtm->rtm_table = tb_id;
 308         RTA_PUT_U32(skb, RTA_TABLE, tb_id);
 309         rtm->rtm_flags = fi->fib_flags;
 310         rtm->rtm_scope = scope;
 311         rtm->rtm_type  = type;
 312         if (rtm->rtm_dst_len)
 313                 RTA_PUT(skb, RTA_DST, 2, dst);
 314         rtm->rtm_protocol = fi->fib_protocol;
 315         if (fi->fib_priority)
 316                 RTA_PUT(skb, RTA_PRIORITY, 4, &fi->fib_priority);
 317         if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0)
 318                 goto rtattr_failure;
 319         if (fi->fib_nhs == 1) {
 320                 if (fi->fib_nh->nh_gw)
 321                         RTA_PUT(skb, RTA_GATEWAY, 2, &fi->fib_nh->nh_gw);
 322                 if (fi->fib_nh->nh_oif)
 323                         RTA_PUT(skb, RTA_OIF, sizeof(int), &fi->fib_nh->nh_oif);
 324         }
 325         if (fi->fib_nhs > 1) {
 326                 struct rtnexthop *nhp;
 327                 struct rtattr *mp_head;
 328                 if (skb_tailroom(skb) <= RTA_SPACE(0))
 329                         goto rtattr_failure;
 330                 mp_head = (struct rtattr *)skb_put(skb, RTA_SPACE(0));
 331
 332                 for_nexthops(fi) {
 333                         if (skb_tailroom(skb) < RTA_ALIGN(RTA_ALIGN(sizeof(*nhp)) + 4))
 334                                 goto rtattr_failure;
 335                         nhp = (struct rtnexthop *)skb_put(skb, RTA_ALIGN(sizeof(*nhp)));
 336                         nhp->rtnh_flags = nh->nh_flags & 0xFF;
 337                         nhp->rtnh_hops = nh->nh_weight - 1;
 338                         nhp->rtnh_ifindex = nh->nh_oif;
 339                         if (nh->nh_gw)
 340                                 RTA_PUT(skb, RTA_GATEWAY, 2, &nh->nh_gw);
 341                         nhp->rtnh_len = skb_tail_pointer(skb) - (unsigned char *)nhp;
 342                 } endfor_nexthops(fi);
 343                 mp_head->rta_type = RTA_MULTIPATH;
 344                 mp_head->rta_len = skb_tail_pointer(skb) - (u8 *)mp_head;
 345         }
 346
 347         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 348         return skb->len;
 349
 350
 351 nlmsg_failure:
 352 rtattr_failure:
 353         nlmsg_trim(skb, b);
 354         return -EMSGSIZE;
 355 }
 356
 357
 358 static void dn_rtmsg_fib(int event, struct dn_fib_node *f, int z, u32 tb_id,
 359                         struct nlmsghdr *nlh, struct netlink_skb_parms *req)
 360 {
 361         struct sk_buff *skb;
 362         u32 pid = req ? req->pid : 0;
 363         int err = -ENOBUFS;
 364
 365         skb = nlmsg_new(dn_fib_nlmsg_size(DN_FIB_INFO(f)), GFP_KERNEL);
 366         if (skb == NULL)
 367                 goto errout;
 368
 369         err = dn_fib_dump_info(skb, pid, nlh->nlmsg_seq, event, tb_id,
 370                                f->fn_type, f->fn_scope, &f->fn_key, z,
 371                                DN_FIB_INFO(f), 0);
 372         if (err < 0) {
 373                 /* -EMSGSIZE implies BUG in dn_fib_nlmsg_size() */
 374                 WARN_ON(err == -EMSGSIZE);
 375                 kfree_skb(skb);
 376                 goto errout;
 377         }
 378         rtnl_notify(skb, &init_net, pid, RTNLGRP_DECnet_ROUTE, nlh, GFP_KERNEL);
 379         return;
 380 errout:
 381         if (err < 0)
 382                 rtnl_set_sk_err(&init_net, RTNLGRP_DECnet_ROUTE, err);
 383 }
 384
 385 static __inline__ int dn_hash_dump_bucket(struct sk_buff *skb,
 386                                 struct netlink_callback *cb,
 387                                 struct dn_fib_table *tb,
 388                                 struct dn_zone *dz,
 389                                 struct dn_fib_node *f)
 390 {
 391         int i, s_i;
 392
 393         s_i = cb->args[4];
 394         for(i = 0; f; i++, f = f->fn_next) {
 395                 if (i < s_i)
 396                         continue;
 397                 if (f->fn_state & DN_S_ZOMBIE)
 398                         continue;
 399                 if (dn_fib_dump_info(skb, NETLINK_CB(cb->skb).pid,
 400                                 cb->nlh->nlmsg_seq,
 401                                 RTM_NEWROUTE,
 402                                 tb->n,
 403                                 (f->fn_state & DN_S_ZOMBIE) ? 0 : f->fn_type,
 404                                 f->fn_scope, &f->fn_key, dz->dz_order,
 405                                 f->fn_info, NLM_F_MULTI) < 0) {
 406                         cb->args[4] = i;
 407                         return -1;
 408                 }
 409         }
 410         cb->args[4] = i;
 411         return skb->len;
 412 }
 413
 414 static __inline__ int dn_hash_dump_zone(struct sk_buff *skb,
 415                                 struct netlink_callback *cb,
 416                                 struct dn_fib_table *tb,
 417                                 struct dn_zone *dz)
 418 {
 419         int h, s_h;
 420
 421         s_h = cb->args[3];
 422         for(h = 0; h < dz->dz_divisor; h++) {
 423                 if (h < s_h)
 424                         continue;
 425                 if (h > s_h)
 426                         memset(&cb->args[4], 0, sizeof(cb->args) - 4*sizeof(cb->args[0]));
 427                 if (dz->dz_hash == NULL || dz->dz_hash[h] == NULL)
 428                         continue;
 429                 if (dn_hash_dump_bucket(skb, cb, tb, dz, dz->dz_hash[h]) < 0) {
 430                         cb->args[3] = h;
 431                         return -1;
 432                 }
 433         }
 434         cb->args[3] = h;
 435         return skb->len;
 436 }
 437
 438 static int dn_fib_table_dump(struct dn_fib_table *tb, struct sk_buff *skb,
 439                                 struct netlink_callback *cb)
 440 {
 441         int m, s_m;
 442         struct dn_zone *dz;
 443         struct dn_hash *table = (struct dn_hash *)tb->data;
 444
 445         s_m = cb->args[2];
 446         read_lock(&dn_fib_tables_lock);
 447         for(dz = table->dh_zone_list, m = 0; dz; dz = dz->dz_next, m++) {
 448                 if (m < s_m)
 449                         continue;
 450                 if (m > s_m)
 451                         memset(&cb->args[3], 0, sizeof(cb->args) - 3*sizeof(cb->args[0]));
 452
 453                 if (dn_hash_dump_zone(skb, cb, tb, dz) < 0) {
 454                         cb->args[2] = m;
 455                         read_unlock(&dn_fib_tables_lock);
 456                         return -1;
 457                 }
 458         }
 459         read_unlock(&dn_fib_tables_lock);
 460         cb->args[2] = m;
 461
 462         return skb->len;
 463 }
 464
 465 int dn_fib_dump(struct sk_buff *skb, struct netlink_callback *cb)
 466 {
 467         struct net *net = sock_net(skb->sk);
 468         unsigned int h, s_h;
 469         unsigned int e = 0, s_e;
 470         struct dn_fib_table *tb;
 471         struct hlist_node *node;
 472         int dumped = 0;
 473
 474         if (net != &init_net)
 475                 return 0;
 476
 477         if (NLMSG_PAYLOAD(cb->nlh, 0) >= sizeof(struct rtmsg) &&
 478                 ((struct rtmsg *)NLMSG_DATA(cb->nlh))->rtm_flags&RTM_F_CLONED)
 479                         return dn_cache_dump(skb, cb);
 480
 481         s_h = cb->args[0];
 482         s_e = cb->args[1];
 483
 484         for (h = s_h; h < DN_FIB_TABLE_HASHSZ; h++, s_h = 0) {
 485                 e = 0;
 486                 hlist_for_each_entry(tb, node, &dn_fib_table_hash[h], hlist) {
 487                         if (e < s_e)
 488                                 goto next;
 489                         if (dumped)
 490                                 memset(&cb->args[2], 0, sizeof(cb->args) -
 491                                                  2 * sizeof(cb->args[0]));
 492                         if (tb->dump(tb, skb, cb) < 0)
 493                                 goto out;
 494                         dumped = 1;
 495 next:
 496                         e++;
 497                 }
 498         }
 499 out:
 500         cb->args[1] = e;
 501         cb->args[0] = h;
 502
 503         return skb->len;
 504 }
 505
 506 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)
 507 {
 508         struct dn_hash *table = (struct dn_hash *)tb->data;
 509         struct dn_fib_node *new_f, *f, **fp, **del_fp;
 510         struct dn_zone *dz;
 511         struct dn_fib_info *fi;
 512         int z = r->rtm_dst_len;
 513         int type = r->rtm_type;
 514         dn_fib_key_t key;
 515         int err;
 516
 517         if (z > 16)
 518                 return -EINVAL;
 519
 520         dz = table->dh_zones[z];
 521         if (!dz && !(dz = dn_new_zone(table, z)))
 522                 return -ENOBUFS;
 523
 524         dz_key_0(key);
 525         if (rta->rta_dst) {
 526                 __le16 dst;
 527                 memcpy(&dst, rta->rta_dst, 2);
 528                 if (dst & ~DZ_MASK(dz))
 529                         return -EINVAL;
 530                 key = dz_key(dst, dz);
 531         }
 532
 533         if ((fi = dn_fib_create_info(r, rta, n, &err)) == NULL)
 534                 return err;
 535
 536         if (dz->dz_nent > (dz->dz_divisor << 2) &&
 537                         dz->dz_divisor > DN_MAX_DIVISOR &&
 538                         (z==16 || (1<<z) > dz->dz_divisor))
 539                 dn_rehash_zone(dz);
 540
 541         fp = dn_chain_p(key, dz);
 542
 543         DN_FIB_SCAN(f, fp) {
 544                 if (dn_key_leq(key, f->fn_key))
 545                         break;
 546         }
 547
 548         del_fp = NULL;
 549
 550         if (f && (f->fn_state & DN_S_ZOMBIE) &&
 551                         dn_key_eq(f->fn_key, key)) {
 552                 del_fp = fp;
 553                 fp = &f->fn_next;
 554                 f = *fp;
 555                 goto create;
 556         }
 557
 558         DN_FIB_SCAN_KEY(f, fp, key) {
 559                 if (fi->fib_priority <= DN_FIB_INFO(f)->fib_priority)
 560                         break;
 561         }
 562
 563         if (f && dn_key_eq(f->fn_key, key) &&
 564                         fi->fib_priority == DN_FIB_INFO(f)->fib_priority) {
 565                 struct dn_fib_node **ins_fp;
 566
 567                 err = -EEXIST;
 568                 if (n->nlmsg_flags & NLM_F_EXCL)
 569                         goto out;
 570
 571                 if (n->nlmsg_flags & NLM_F_REPLACE) {
 572                         del_fp = fp;
 573                         fp = &f->fn_next;
 574                         f = *fp;
 575                         goto replace;
 576                 }
 577
 578                 ins_fp = fp;
 579                 err = -EEXIST;
 580
 581                 DN_FIB_SCAN_KEY(f, fp, key) {
 582                         if (fi->fib_priority != DN_FIB_INFO(f)->fib_priority)
 583                                 break;
 584                         if (f->fn_type == type && f->fn_scope == r->rtm_scope
 585                                         && DN_FIB_INFO(f) == fi)
 586                                 goto out;
 587                 }
 588
 589                 if (!(n->nlmsg_flags & NLM_F_APPEND)) {
 590                         fp = ins_fp;
 591                         f = *fp;
 592                 }
 593         }
 594
 595 create:
 596         err = -ENOENT;
 597         if (!(n->nlmsg_flags & NLM_F_CREATE))
 598                 goto out;
 599
 600 replace:
 601         err = -ENOBUFS;
 602         new_f = kmem_cache_zalloc(dn_hash_kmem, GFP_KERNEL);
 603         if (new_f == NULL)
 604                 goto out;
 605
 606         new_f->fn_key = key;
 607         new_f->fn_type = type;
 608         new_f->fn_scope = r->rtm_scope;
 609         DN_FIB_INFO(new_f) = fi;
 610
 611         new_f->fn_next = f;
 612         write_lock_bh(&dn_fib_tables_lock);
 613         *fp = new_f;
 614         write_unlock_bh(&dn_fib_tables_lock);
 615         dz->dz_nent++;
 616
 617         if (del_fp) {
 618                 f = *del_fp;
 619                 write_lock_bh(&dn_fib_tables_lock);
 620                 *del_fp = f->fn_next;
 621                 write_unlock_bh(&dn_fib_tables_lock);
 622
 623                 if (!(f->fn_state & DN_S_ZOMBIE))
 624                         dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 625                 if (f->fn_state & DN_S_ACCESSED)
 626                         dn_rt_cache_flush(-1);
 627                 dn_free_node(f);
 628                 dz->dz_nent--;
 629         } else {
 630                 dn_rt_cache_flush(-1);
 631         }
 632
 633         dn_rtmsg_fib(RTM_NEWROUTE, new_f, z, tb->n, n, req);
 634
 635         return 0;
 636 out:
 637         dn_fib_release_info(fi);
 638         return err;
 639 }
 640
 641
 642 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)
 643 {
 644         struct dn_hash *table = (struct dn_hash*)tb->data;
 645         struct dn_fib_node **fp, **del_fp, *f;
 646         int z = r->rtm_dst_len;
 647         struct dn_zone *dz;
 648         dn_fib_key_t key;
 649         int matched;
 650
 651
 652         if (z > 16)
 653                 return -EINVAL;
 654
 655         if ((dz = table->dh_zones[z]) == NULL)
 656                 return -ESRCH;
 657
 658         dz_key_0(key);
 659         if (rta->rta_dst) {
 660                 __le16 dst;
 661                 memcpy(&dst, rta->rta_dst, 2);
 662                 if (dst & ~DZ_MASK(dz))
 663                         return -EINVAL;
 664                 key = dz_key(dst, dz);
 665         }
 666
 667         fp = dn_chain_p(key, dz);
 668
 669         DN_FIB_SCAN(f, fp) {
 670                 if (dn_key_eq(f->fn_key, key))
 671                         break;
 672                 if (dn_key_leq(key, f->fn_key))
 673                         return -ESRCH;
 674         }
 675
 676         matched = 0;
 677         del_fp = NULL;
 678         DN_FIB_SCAN_KEY(f, fp, key) {
 679                 struct dn_fib_info *fi = DN_FIB_INFO(f);
 680
 681                 if (f->fn_state & DN_S_ZOMBIE)
 682                         return -ESRCH;
 683
 684                 matched++;
 685
 686                 if (del_fp == NULL &&
 687                                 (!r->rtm_type || f->fn_type == r->rtm_type) &&
 688                                 (r->rtm_scope == RT_SCOPE_NOWHERE || f->fn_scope == r->rtm_scope) &&
 689                                 (!r->rtm_protocol ||
 690                                         fi->fib_protocol == r->rtm_protocol) &&
 691                                 dn_fib_nh_match(r, n, rta, fi) == 0)
 692                         del_fp = fp;
 693         }
 694
 695         if (del_fp) {
 696                 f = *del_fp;
 697                 dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 698
 699                 if (matched != 1) {
 700                         write_lock_bh(&dn_fib_tables_lock);
 701                         *del_fp = f->fn_next;
 702                         write_unlock_bh(&dn_fib_tables_lock);
 703
 704                         if (f->fn_state & DN_S_ACCESSED)
 705                                 dn_rt_cache_flush(-1);
 706                         dn_free_node(f);
 707                         dz->dz_nent--;
 708                 } else {
 709                         f->fn_state |= DN_S_ZOMBIE;
 710                         if (f->fn_state & DN_S_ACCESSED) {
 711                                 f->fn_state &= ~DN_S_ACCESSED;
 712                                 dn_rt_cache_flush(-1);
 713                         }
 714                         if (++dn_fib_hash_zombies > 128)
 715                                 dn_fib_flush();
 716                 }
 717
 718                 return 0;
 719         }
 720
 721         return -ESRCH;
 722 }
 723
 724 static inline int dn_flush_list(struct dn_fib_node **fp, int z, struct dn_hash *table)
 725 {
 726         int found = 0;
 727         struct dn_fib_node *f;
 728
 729         while((f = *fp) != NULL) {
 730                 struct dn_fib_info *fi = DN_FIB_INFO(f);
 731
 732                 if (fi && ((f->fn_state & DN_S_ZOMBIE) || (fi->fib_flags & RTNH_F_DEAD))) {
 733                         write_lock_bh(&dn_fib_tables_lock);
 734                         *fp = f->fn_next;
 735                         write_unlock_bh(&dn_fib_tables_lock);
 736
 737                         dn_free_node(f);
 738                         found++;
 739                         continue;
 740                 }
 741                 fp = &f->fn_next;
 742         }
 743
 744         return found;
 745 }
 746
 747 static int dn_fib_table_flush(struct dn_fib_table *tb)
 748 {
 749         struct dn_hash *table = (struct dn_hash *)tb->data;
 750         struct dn_zone *dz;
 751         int found = 0;
 752
 753         dn_fib_hash_zombies = 0;
 754         for(dz = table->dh_zone_list; dz; dz = dz->dz_next) {
 755                 int i;
 756                 int tmp = 0;
 757                 for(i = dz->dz_divisor-1; i >= 0; i--)
 758                         tmp += dn_flush_list(&dz->dz_hash[i], dz->dz_order, table);
 759                 dz->dz_nent -= tmp;
 760                 found += tmp;
 761         }
 762
 763         return found;
 764 }
 765
 766 static int dn_fib_table_lookup(struct dn_fib_table *tb, const struct flowi *flp, struct dn_fib_res *res)
 767 {
 768         int err;
 769         struct dn_zone *dz;
 770         struct dn_hash *t = (struct dn_hash *)tb->data;
 771
 772         read_lock(&dn_fib_tables_lock);
 773         for(dz = t->dh_zone_list; dz; dz = dz->dz_next) {
 774                 struct dn_fib_node *f;
 775                 dn_fib_key_t k = dz_key(flp->fld_dst, dz);
 776
 777                 for(f = dz_chain(k, dz); f; f = f->fn_next) {
 778                         if (!dn_key_eq(k, f->fn_key)) {
 779                                 if (dn_key_leq(k, f->fn_key))
 780                                         break;
 781                                 else
 782                                         continue;
 783                         }
 784
 785                         f->fn_state |= DN_S_ACCESSED;
 786
 787                         if (f->fn_state&DN_S_ZOMBIE)
 788                                 continue;
 789
 790                         if (f->fn_scope < flp->fld_scope)
 791                                 continue;
 792
 793                         err = dn_fib_semantic_match(f->fn_type, DN_FIB_INFO(f), flp, res);
 794
 795                         if (err == 0) {
 796                                 res->type = f->fn_type;
 797                                 res->scope = f->fn_scope;
 798                                 res->prefixlen = dz->dz_order;
 799                                 goto out;
 800                         }
 801                         if (err < 0)
 802                                 goto out;
 803                 }
 804         }
 805         err = 1;
 806 out:
 807         read_unlock(&dn_fib_tables_lock);
 808         return err;
 809 }
 810
 811
 812 struct dn_fib_table *dn_fib_get_table(u32 n, int create)
 813 {
 814         struct dn_fib_table *t;
 815         struct hlist_node *node;
 816         unsigned int h;
 817
 818         if (n < RT_TABLE_MIN)
 819                 return NULL;
 820
 821         if (n > RT_TABLE_MAX)
 822                 return NULL;
 823
 824         h = n & (DN_FIB_TABLE_HASHSZ - 1);
 825         rcu_read_lock();
 826         hlist_for_each_entry_rcu(t, node, &dn_fib_table_hash[h], hlist) {
 827                 if (t->n == n) {
 828                         rcu_read_unlock();
 829                         return t;
 830                 }
 831         }
 832         rcu_read_unlock();
 833
 834         if (!create)
 835                 return NULL;
 836
 837         if (in_interrupt() && net_ratelimit()) {
 838                 printk(KERN_DEBUG "DECnet: BUG! Attempt to create routing table from interrupt\n");
 839                 return NULL;
 840         }
 841
 842         t = kzalloc(sizeof(struct dn_fib_table) + sizeof(struct dn_hash),
 843                     GFP_KERNEL);
 844         if (t == NULL)
 845                 return NULL;
 846
 847         t->n = n;
 848         t->insert = dn_fib_table_insert;
 849         t->delete = dn_fib_table_delete;
 850         t->lookup = dn_fib_table_lookup;
 851         t->flush  = dn_fib_table_flush;
 852         t->dump = dn_fib_table_dump;
 853         hlist_add_head_rcu(&t->hlist, &dn_fib_table_hash[h]);
 854
 855         return t;
 856 }
 857
 858 struct dn_fib_table *dn_fib_empty_table(void)
 859 {
 860         u32 id;
 861
 862         for(id = RT_TABLE_MIN; id <= RT_TABLE_MAX; id++)
 863                 if (dn_fib_get_table(id, 0) == NULL)
 864                         return dn_fib_get_table(id, 1);
 865         return NULL;
 866 }
 867
 868 void dn_fib_flush(void)
 869 {
 870         int flushed = 0;
 871         struct dn_fib_table *tb;
 872         struct hlist_node *node;
 873         unsigned int h;
 874
 875         for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
 876                 hlist_for_each_entry(tb, node, &dn_fib_table_hash[h], hlist)
 877                         flushed += tb->flush(tb);
 878         }
 879
 880         if (flushed)
 881                 dn_rt_cache_flush(-1);
 882 }
 883
 884 void __init dn_fib_table_init(void)
 885 {
 886         dn_hash_kmem = kmem_cache_create("dn_fib_info_cache",
 887                                         sizeof(struct dn_fib_info),
 888                                         0, SLAB_HWCACHE_ALIGN,
 889                                         NULL);
 890 }
 891
 892 void __exit dn_fib_table_cleanup(void)
 893 {
 894         struct dn_fib_table *t;
 895         struct hlist_node *node, *next;
 896         unsigned int h;
 897
 898         write_lock(&dn_fib_tables_lock);
 899         for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
 900                 hlist_for_each_entry_safe(t, node, next, &dn_fib_table_hash[h],
 901                                           hlist) {
 902                         hlist_del(&t->hlist);
 903                         kfree(t);
 904                 }
 905         }
 906         write_unlock(&dn_fib_tables_lock);
 907 }