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/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
  62 #define for_nexthops(fi) { int nhsel; const struct dn_fib_nh *nh;\
  63         for(nhsel = 0, nh = (fi)->fib_nh; nhsel < (fi)->fib_nhs; nh++, nhsel++)
  64
  65 #define endfor_nexthops(fi) }
  66
  67 #define DN_MAX_DIVISOR 1024
  68 #define DN_S_ZOMBIE 1
  69 #define DN_S_ACCESSED 2
  70
  71 #define DN_FIB_SCAN(f, fp) \
  72 for( ; ((f) = *(fp)) != NULL; (fp) = &(f)->fn_next)
  73
  74 #define DN_FIB_SCAN_KEY(f, fp, key) \
  75 for( ; ((f) = *(fp)) != NULL && dn_key_eq((f)->fn_key, (key)); (fp) = &(f)->fn_next)
  76
  77 #define RT_TABLE_MIN 1
  78 #define DN_FIB_TABLE_HASHSZ 256
  79 static struct hlist_head dn_fib_table_hash[DN_FIB_TABLE_HASHSZ];
  80 static DEFINE_RWLOCK(dn_fib_tables_lock);
  81
  82 static struct kmem_cache *dn_hash_kmem __read_mostly;
  83 static int dn_fib_hash_zombies;
  84
  85 static inline dn_fib_idx_t dn_hash(dn_fib_key_t key, struct dn_zone *dz)
  86 {
  87         u16 h = le16_to_cpu(key.datum)>>(16 - dz->dz_order);
  88         h ^= (h >> 10);
  89         h ^= (h >> 6);
  90         h &= DZ_HASHMASK(dz);
  91         return *(dn_fib_idx_t *)&h;
  92 }
  93
  94 static inline dn_fib_key_t dz_key(__le16 dst, struct dn_zone *dz)
  95 {
  96         dn_fib_key_t k;
  97         k.datum = dst & DZ_MASK(dz);
  98         return k;
  99 }
 100
 101 static inline struct dn_fib_node **dn_chain_p(dn_fib_key_t key, struct dn_zone *dz)
 102 {
 103         return &dz->dz_hash[dn_hash(key, dz).datum];
 104 }
 105
 106 static inline struct dn_fib_node *dz_chain(dn_fib_key_t key, struct dn_zone *dz)
 107 {
 108         return dz->dz_hash[dn_hash(key, dz).datum];
 109 }
 110
 111 static inline int dn_key_eq(dn_fib_key_t a, dn_fib_key_t b)
 112 {
 113         return a.datum == b.datum;
 114 }
 115
 116 static inline int dn_key_leq(dn_fib_key_t a, dn_fib_key_t b)
 117 {
 118         return a.datum <= b.datum;
 119 }
 120
 121 static inline void dn_rebuild_zone(struct dn_zone *dz,
 122                                    struct dn_fib_node **old_ht,
 123                                    int old_divisor)
 124 {
 125         struct dn_fib_node *f, **fp, *next;
 126         int i;
 127
 128         for(i = 0; i < old_divisor; i++) {
 129                 for(f = old_ht[i]; f; f = next) {
 130                         next = f->fn_next;
 131                         for(fp = dn_chain_p(f->fn_key, dz);
 132                                 *fp && dn_key_leq((*fp)->fn_key, f->fn_key);
 133                                 fp = &(*fp)->fn_next)
 134                                 /* NOTHING */;
 135                         f->fn_next = *fp;
 136                         *fp = f;
 137                 }
 138         }
 139 }
 140
 141 static void dn_rehash_zone(struct dn_zone *dz)
 142 {
 143         struct dn_fib_node **ht, **old_ht;
 144         int old_divisor, new_divisor;
 145         u32 new_hashmask;
 146
 147         old_divisor = dz->dz_divisor;
 148
 149         switch (old_divisor) {
 150         case 16:
 151                 new_divisor = 256;
 152                 new_hashmask = 0xFF;
 153                 break;
 154         default:
 155                 printk(KERN_DEBUG "DECnet: dn_rehash_zone: BUG! %d\n",
 156                        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 nlattr *attrs[], struct dn_fib_info *fi)
 227 {
 228         struct rtnexthop *nhp;
 229         int nhlen;
 230
 231         if (attrs[RTA_PRIORITY] &&
 232             nla_get_u32(attrs[RTA_PRIORITY]) != fi->fib_priority)
 233                 return 1;
 234
 235         if (attrs[RTA_OIF] || attrs[RTA_GATEWAY]) {
 236                 if ((!attrs[RTA_OIF] || nla_get_u32(attrs[RTA_OIF]) == fi->fib_nh->nh_oif) &&
 237                     (!attrs[RTA_GATEWAY]  || nla_get_le16(attrs[RTA_GATEWAY]) != fi->fib_nh->nh_gw))
 238                         return 0;
 239                 return 1;
 240         }
 241
 242         if (!attrs[RTA_MULTIPATH])
 243                 return 0;
 244
 245         nhp = nla_data(attrs[RTA_MULTIPATH]);
 246         nhlen = nla_len(attrs[RTA_MULTIPATH]);
 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                         struct nlattr *gw_attr;
 258
 259                         gw_attr = nla_find((struct nlattr *) (nhp + 1), attrlen, RTA_GATEWAY);
 260                         gw = gw_attr ? nla_get_le16(gw_attr) : 0;
 261
 262                         if (gw && gw != nh->nh_gw)
 263                                 return 1;
 264                 }
 265                 nhp = RTNH_NEXT(nhp);
 266         } endfor_nexthops(fi);
 267
 268         return 0;
 269 }
 270
 271 static inline size_t dn_fib_nlmsg_size(struct dn_fib_info *fi)
 272 {
 273         size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg))
 274                          + nla_total_size(4) /* RTA_TABLE */
 275                          + nla_total_size(2) /* RTA_DST */
 276                          + nla_total_size(4); /* RTA_PRIORITY */
 277
 278         /* space for nested metrics */
 279         payload += nla_total_size((RTAX_MAX * nla_total_size(4)));
 280
 281         if (fi->fib_nhs) {
 282                 /* Also handles the special case fib_nhs == 1 */
 283
 284                 /* each nexthop is packed in an attribute */
 285                 size_t nhsize = nla_total_size(sizeof(struct rtnexthop));
 286
 287                 /* may contain a gateway attribute */
 288                 nhsize += nla_total_size(4);
 289
 290                 /* all nexthops are packed in a nested attribute */
 291                 payload += nla_total_size(fi->fib_nhs * nhsize);
 292         }
 293
 294         return payload;
 295 }
 296
 297 static int dn_fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event,
 298                         u32 tb_id, u8 type, u8 scope, void *dst, int dst_len,
 299                         struct dn_fib_info *fi, unsigned int flags)
 300 {
 301         struct rtmsg *rtm;
 302         struct nlmsghdr *nlh;
 303
 304         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags);
 305         if (!nlh)
 306                 return -EMSGSIZE;
 307
 308         rtm = nlmsg_data(nlh);
 309         rtm->rtm_family = AF_DECnet;
 310         rtm->rtm_dst_len = dst_len;
 311         rtm->rtm_src_len = 0;
 312         rtm->rtm_tos = 0;
 313         rtm->rtm_table = tb_id;
 314         rtm->rtm_flags = fi->fib_flags;
 315         rtm->rtm_scope = scope;
 316         rtm->rtm_type  = type;
 317         rtm->rtm_protocol = fi->fib_protocol;
 318
 319         if (nla_put_u32(skb, RTA_TABLE, tb_id) < 0)
 320                 goto errout;
 321
 322         if (rtm->rtm_dst_len &&
 323             nla_put(skb, RTA_DST, 2, dst) < 0)
 324                 goto errout;
 325
 326         if (fi->fib_priority &&
 327             nla_put_u32(skb, RTA_PRIORITY, fi->fib_priority) < 0)
 328                 goto errout;
 329
 330         if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0)
 331                 goto errout;
 332
 333         if (fi->fib_nhs == 1) {
 334                 if (fi->fib_nh->nh_gw &&
 335                     nla_put_le16(skb, RTA_GATEWAY, fi->fib_nh->nh_gw) < 0)
 336                         goto errout;
 337
 338                 if (fi->fib_nh->nh_oif &&
 339                     nla_put_u32(skb, RTA_OIF, fi->fib_nh->nh_oif) < 0)
 340                         goto errout;
 341         }
 342
 343         if (fi->fib_nhs > 1) {
 344                 struct rtnexthop *nhp;
 345                 struct nlattr *mp_head;
 346
 347                 if (!(mp_head = nla_nest_start(skb, RTA_MULTIPATH)))
 348                         goto errout;
 349
 350                 for_nexthops(fi) {
 351                         if (!(nhp = nla_reserve_nohdr(skb, sizeof(*nhp))))
 352                                 goto errout;
 353
 354                         nhp->rtnh_flags = nh->nh_flags & 0xFF;
 355                         nhp->rtnh_hops = nh->nh_weight - 1;
 356                         nhp->rtnh_ifindex = nh->nh_oif;
 357
 358                         if (nh->nh_gw &&
 359                             nla_put_le16(skb, RTA_GATEWAY, nh->nh_gw) < 0)
 360                                 goto errout;
 361
 362                         nhp->rtnh_len = skb_tail_pointer(skb) - (unsigned char *)nhp;
 363                 } endfor_nexthops(fi);
 364
 365                 nla_nest_end(skb, mp_head);
 366         }
 367
 368         return nlmsg_end(skb, nlh);
 369
 370 errout:
 371         nlmsg_cancel(skb, nlh);
 372         return -EMSGSIZE;
 373 }
 374
 375
 376 static void dn_rtmsg_fib(int event, struct dn_fib_node *f, int z, u32 tb_id,
 377                         struct nlmsghdr *nlh, struct netlink_skb_parms *req)
 378 {
 379         struct sk_buff *skb;
 380         u32 portid = req ? req->portid : 0;
 381         int err = -ENOBUFS;
 382
 383         skb = nlmsg_new(dn_fib_nlmsg_size(DN_FIB_INFO(f)), GFP_KERNEL);
 384         if (skb == NULL)
 385                 goto errout;
 386
 387         err = dn_fib_dump_info(skb, portid, nlh->nlmsg_seq, event, tb_id,
 388                                f->fn_type, f->fn_scope, &f->fn_key, z,
 389                                DN_FIB_INFO(f), 0);
 390         if (err < 0) {
 391                 /* -EMSGSIZE implies BUG in dn_fib_nlmsg_size() */
 392                 WARN_ON(err == -EMSGSIZE);
 393                 kfree_skb(skb);
 394                 goto errout;
 395         }
 396         rtnl_notify(skb, &init_net, portid, RTNLGRP_DECnet_ROUTE, nlh, GFP_KERNEL);
 397         return;
 398 errout:
 399         if (err < 0)
 400                 rtnl_set_sk_err(&init_net, RTNLGRP_DECnet_ROUTE, err);
 401 }
 402
 403 static __inline__ int dn_hash_dump_bucket(struct sk_buff *skb,
 404                                 struct netlink_callback *cb,
 405                                 struct dn_fib_table *tb,
 406                                 struct dn_zone *dz,
 407                                 struct dn_fib_node *f)
 408 {
 409         int i, s_i;
 410
 411         s_i = cb->args[4];
 412         for(i = 0; f; i++, f = f->fn_next) {
 413                 if (i < s_i)
 414                         continue;
 415                 if (f->fn_state & DN_S_ZOMBIE)
 416                         continue;
 417                 if (dn_fib_dump_info(skb, NETLINK_CB(cb->skb).portid,
 418                                 cb->nlh->nlmsg_seq,
 419                                 RTM_NEWROUTE,
 420                                 tb->n,
 421                                 (f->fn_state & DN_S_ZOMBIE) ? 0 : f->fn_type,
 422                                 f->fn_scope, &f->fn_key, dz->dz_order,
 423                                 f->fn_info, NLM_F_MULTI) < 0) {
 424                         cb->args[4] = i;
 425                         return -1;
 426                 }
 427         }
 428         cb->args[4] = i;
 429         return skb->len;
 430 }
 431
 432 static __inline__ int dn_hash_dump_zone(struct sk_buff *skb,
 433                                 struct netlink_callback *cb,
 434                                 struct dn_fib_table *tb,
 435                                 struct dn_zone *dz)
 436 {
 437         int h, s_h;
 438
 439         s_h = cb->args[3];
 440         for(h = 0; h < dz->dz_divisor; h++) {
 441                 if (h < s_h)
 442                         continue;
 443                 if (h > s_h)
 444                         memset(&cb->args[4], 0, sizeof(cb->args) - 4*sizeof(cb->args[0]));
 445                 if (dz->dz_hash == NULL || dz->dz_hash[h] == NULL)
 446                         continue;
 447                 if (dn_hash_dump_bucket(skb, cb, tb, dz, dz->dz_hash[h]) < 0) {
 448                         cb->args[3] = h;
 449                         return -1;
 450                 }
 451         }
 452         cb->args[3] = h;
 453         return skb->len;
 454 }
 455
 456 static int dn_fib_table_dump(struct dn_fib_table *tb, struct sk_buff *skb,
 457                                 struct netlink_callback *cb)
 458 {
 459         int m, s_m;
 460         struct dn_zone *dz;
 461         struct dn_hash *table = (struct dn_hash *)tb->data;
 462
 463         s_m = cb->args[2];
 464         read_lock(&dn_fib_tables_lock);
 465         for(dz = table->dh_zone_list, m = 0; dz; dz = dz->dz_next, m++) {
 466                 if (m < s_m)
 467                         continue;
 468                 if (m > s_m)
 469                         memset(&cb->args[3], 0, sizeof(cb->args) - 3*sizeof(cb->args[0]));
 470
 471                 if (dn_hash_dump_zone(skb, cb, tb, dz) < 0) {
 472                         cb->args[2] = m;
 473                         read_unlock(&dn_fib_tables_lock);
 474                         return -1;
 475                 }
 476         }
 477         read_unlock(&dn_fib_tables_lock);
 478         cb->args[2] = m;
 479
 480         return skb->len;
 481 }
 482
 483 int dn_fib_dump(struct sk_buff *skb, struct netlink_callback *cb)
 484 {
 485         struct net *net = sock_net(skb->sk);
 486         unsigned int h, s_h;
 487         unsigned int e = 0, s_e;
 488         struct dn_fib_table *tb;
 489         int dumped = 0;
 490
 491         if (!net_eq(net, &init_net))
 492                 return 0;
 493
 494         if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
 495                 ((struct rtmsg *)nlmsg_data(cb->nlh))->rtm_flags&RTM_F_CLONED)
 496                         return dn_cache_dump(skb, cb);
 497
 498         s_h = cb->args[0];
 499         s_e = cb->args[1];
 500
 501         for (h = s_h; h < DN_FIB_TABLE_HASHSZ; h++, s_h = 0) {
 502                 e = 0;
 503                 hlist_for_each_entry(tb, &dn_fib_table_hash[h], hlist) {
 504                         if (e < s_e)
 505                                 goto next;
 506                         if (dumped)
 507                                 memset(&cb->args[2], 0, sizeof(cb->args) -
 508                                                  2 * sizeof(cb->args[0]));
 509                         if (tb->dump(tb, skb, cb) < 0)
 510                                 goto out;
 511                         dumped = 1;
 512 next:
 513                         e++;
 514                 }
 515         }
 516 out:
 517         cb->args[1] = e;
 518         cb->args[0] = h;
 519
 520         return skb->len;
 521 }
 522
 523 static int dn_fib_table_insert(struct dn_fib_table *tb, struct rtmsg *r, struct nlattr *attrs[],
 524                                struct nlmsghdr *n, struct netlink_skb_parms *req)
 525 {
 526         struct dn_hash *table = (struct dn_hash *)tb->data;
 527         struct dn_fib_node *new_f, *f, **fp, **del_fp;
 528         struct dn_zone *dz;
 529         struct dn_fib_info *fi;
 530         int z = r->rtm_dst_len;
 531         int type = r->rtm_type;
 532         dn_fib_key_t key;
 533         int err;
 534
 535         if (z > 16)
 536                 return -EINVAL;
 537
 538         dz = table->dh_zones[z];
 539         if (!dz && !(dz = dn_new_zone(table, z)))
 540                 return -ENOBUFS;
 541
 542         dz_key_0(key);
 543         if (attrs[RTA_DST]) {
 544                 __le16 dst = nla_get_le16(attrs[RTA_DST]);
 545                 if (dst & ~DZ_MASK(dz))
 546                         return -EINVAL;
 547                 key = dz_key(dst, dz);
 548         }
 549
 550         if ((fi = dn_fib_create_info(r, attrs, n, &err)) == NULL)
 551                 return err;
 552
 553         if (dz->dz_nent > (dz->dz_divisor << 2) &&
 554                         dz->dz_divisor > DN_MAX_DIVISOR &&
 555                         (z==16 || (1<<z) > dz->dz_divisor))
 556                 dn_rehash_zone(dz);
 557
 558         fp = dn_chain_p(key, dz);
 559
 560         DN_FIB_SCAN(f, fp) {
 561                 if (dn_key_leq(key, f->fn_key))
 562                         break;
 563         }
 564
 565         del_fp = NULL;
 566
 567         if (f && (f->fn_state & DN_S_ZOMBIE) &&
 568                         dn_key_eq(f->fn_key, key)) {
 569                 del_fp = fp;
 570                 fp = &f->fn_next;
 571                 f = *fp;
 572                 goto create;
 573         }
 574
 575         DN_FIB_SCAN_KEY(f, fp, key) {
 576                 if (fi->fib_priority <= DN_FIB_INFO(f)->fib_priority)
 577                         break;
 578         }
 579
 580         if (f && dn_key_eq(f->fn_key, key) &&
 581                         fi->fib_priority == DN_FIB_INFO(f)->fib_priority) {
 582                 struct dn_fib_node **ins_fp;
 583
 584                 err = -EEXIST;
 585                 if (n->nlmsg_flags & NLM_F_EXCL)
 586                         goto out;
 587
 588                 if (n->nlmsg_flags & NLM_F_REPLACE) {
 589                         del_fp = fp;
 590                         fp = &f->fn_next;
 591                         f = *fp;
 592                         goto replace;
 593                 }
 594
 595                 ins_fp = fp;
 596                 err = -EEXIST;
 597
 598                 DN_FIB_SCAN_KEY(f, fp, key) {
 599                         if (fi->fib_priority != DN_FIB_INFO(f)->fib_priority)
 600                                 break;
 601                         if (f->fn_type == type &&
 602                             f->fn_scope == r->rtm_scope &&
 603                             DN_FIB_INFO(f) == fi)
 604                                 goto out;
 605                 }
 606
 607                 if (!(n->nlmsg_flags & NLM_F_APPEND)) {
 608                         fp = ins_fp;
 609                         f = *fp;
 610                 }
 611         }
 612
 613 create:
 614         err = -ENOENT;
 615         if (!(n->nlmsg_flags & NLM_F_CREATE))
 616                 goto out;
 617
 618 replace:
 619         err = -ENOBUFS;
 620         new_f = kmem_cache_zalloc(dn_hash_kmem, GFP_KERNEL);
 621         if (new_f == NULL)
 622                 goto out;
 623
 624         new_f->fn_key = key;
 625         new_f->fn_type = type;
 626         new_f->fn_scope = r->rtm_scope;
 627         DN_FIB_INFO(new_f) = fi;
 628
 629         new_f->fn_next = f;
 630         write_lock_bh(&dn_fib_tables_lock);
 631         *fp = new_f;
 632         write_unlock_bh(&dn_fib_tables_lock);
 633         dz->dz_nent++;
 634
 635         if (del_fp) {
 636                 f = *del_fp;
 637                 write_lock_bh(&dn_fib_tables_lock);
 638                 *del_fp = f->fn_next;
 639                 write_unlock_bh(&dn_fib_tables_lock);
 640
 641                 if (!(f->fn_state & DN_S_ZOMBIE))
 642                         dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 643                 if (f->fn_state & DN_S_ACCESSED)
 644                         dn_rt_cache_flush(-1);
 645                 dn_free_node(f);
 646                 dz->dz_nent--;
 647         } else {
 648                 dn_rt_cache_flush(-1);
 649         }
 650
 651         dn_rtmsg_fib(RTM_NEWROUTE, new_f, z, tb->n, n, req);
 652
 653         return 0;
 654 out:
 655         dn_fib_release_info(fi);
 656         return err;
 657 }
 658
 659
 660 static int dn_fib_table_delete(struct dn_fib_table *tb, struct rtmsg *r, struct nlattr *attrs[],
 661                                struct nlmsghdr *n, struct netlink_skb_parms *req)
 662 {
 663         struct dn_hash *table = (struct dn_hash*)tb->data;
 664         struct dn_fib_node **fp, **del_fp, *f;
 665         int z = r->rtm_dst_len;
 666         struct dn_zone *dz;
 667         dn_fib_key_t key;
 668         int matched;
 669
 670
 671         if (z > 16)
 672                 return -EINVAL;
 673
 674         if ((dz = table->dh_zones[z]) == NULL)
 675                 return -ESRCH;
 676
 677         dz_key_0(key);
 678         if (attrs[RTA_DST]) {
 679                 __le16 dst = nla_get_le16(attrs[RTA_DST]);
 680                 if (dst & ~DZ_MASK(dz))
 681                         return -EINVAL;
 682                 key = dz_key(dst, dz);
 683         }
 684
 685         fp = dn_chain_p(key, dz);
 686
 687         DN_FIB_SCAN(f, fp) {
 688                 if (dn_key_eq(f->fn_key, key))
 689                         break;
 690                 if (dn_key_leq(key, f->fn_key))
 691                         return -ESRCH;
 692         }
 693
 694         matched = 0;
 695         del_fp = NULL;
 696         DN_FIB_SCAN_KEY(f, fp, key) {
 697                 struct dn_fib_info *fi = DN_FIB_INFO(f);
 698
 699                 if (f->fn_state & DN_S_ZOMBIE)
 700                         return -ESRCH;
 701
 702                 matched++;
 703
 704                 if (del_fp == NULL &&
 705                                 (!r->rtm_type || f->fn_type == r->rtm_type) &&
 706                                 (r->rtm_scope == RT_SCOPE_NOWHERE || f->fn_scope == r->rtm_scope) &&
 707                                 (!r->rtm_protocol ||
 708                                         fi->fib_protocol == r->rtm_protocol) &&
 709                                 dn_fib_nh_match(r, n, attrs, fi) == 0)
 710                         del_fp = fp;
 711         }
 712
 713         if (del_fp) {
 714                 f = *del_fp;
 715                 dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 716
 717                 if (matched != 1) {
 718                         write_lock_bh(&dn_fib_tables_lock);
 719                         *del_fp = f->fn_next;
 720                         write_unlock_bh(&dn_fib_tables_lock);
 721
 722                         if (f->fn_state & DN_S_ACCESSED)
 723                                 dn_rt_cache_flush(-1);
 724                         dn_free_node(f);
 725                         dz->dz_nent--;
 726                 } else {
 727                         f->fn_state |= DN_S_ZOMBIE;
 728                         if (f->fn_state & DN_S_ACCESSED) {
 729                                 f->fn_state &= ~DN_S_ACCESSED;
 730                                 dn_rt_cache_flush(-1);
 731                         }
 732                         if (++dn_fib_hash_zombies > 128)
 733                                 dn_fib_flush();
 734                 }
 735
 736                 return 0;
 737         }
 738
 739         return -ESRCH;
 740 }
 741
 742 static inline int dn_flush_list(struct dn_fib_node **fp, int z, struct dn_hash *table)
 743 {
 744         int found = 0;
 745         struct dn_fib_node *f;
 746
 747         while((f = *fp) != NULL) {
 748                 struct dn_fib_info *fi = DN_FIB_INFO(f);
 749
 750                 if (fi && ((f->fn_state & DN_S_ZOMBIE) || (fi->fib_flags & RTNH_F_DEAD))) {
 751                         write_lock_bh(&dn_fib_tables_lock);
 752                         *fp = f->fn_next;
 753                         write_unlock_bh(&dn_fib_tables_lock);
 754
 755                         dn_free_node(f);
 756                         found++;
 757                         continue;
 758                 }
 759                 fp = &f->fn_next;
 760         }
 761
 762         return found;
 763 }
 764
 765 static int dn_fib_table_flush(struct dn_fib_table *tb)
 766 {
 767         struct dn_hash *table = (struct dn_hash *)tb->data;
 768         struct dn_zone *dz;
 769         int found = 0;
 770
 771         dn_fib_hash_zombies = 0;
 772         for(dz = table->dh_zone_list; dz; dz = dz->dz_next) {
 773                 int i;
 774                 int tmp = 0;
 775                 for(i = dz->dz_divisor-1; i >= 0; i--)
 776                         tmp += dn_flush_list(&dz->dz_hash[i], dz->dz_order, table);
 777                 dz->dz_nent -= tmp;
 778                 found += tmp;
 779         }
 780
 781         return found;
 782 }
 783
 784 static int dn_fib_table_lookup(struct dn_fib_table *tb, const struct flowidn *flp, struct dn_fib_res *res)
 785 {
 786         int err;
 787         struct dn_zone *dz;
 788         struct dn_hash *t = (struct dn_hash *)tb->data;
 789
 790         read_lock(&dn_fib_tables_lock);
 791         for(dz = t->dh_zone_list; dz; dz = dz->dz_next) {
 792                 struct dn_fib_node *f;
 793                 dn_fib_key_t k = dz_key(flp->daddr, dz);
 794
 795                 for(f = dz_chain(k, dz); f; f = f->fn_next) {
 796                         if (!dn_key_eq(k, f->fn_key)) {
 797                                 if (dn_key_leq(k, f->fn_key))
 798                                         break;
 799                                 else
 800                                         continue;
 801                         }
 802
 803                         f->fn_state |= DN_S_ACCESSED;
 804
 805                         if (f->fn_state&DN_S_ZOMBIE)
 806                                 continue;
 807
 808                         if (f->fn_scope < flp->flowidn_scope)
 809                                 continue;
 810
 811                         err = dn_fib_semantic_match(f->fn_type, DN_FIB_INFO(f), flp, res);
 812
 813                         if (err == 0) {
 814                                 res->type = f->fn_type;
 815                                 res->scope = f->fn_scope;
 816                                 res->prefixlen = dz->dz_order;
 817                                 goto out;
 818                         }
 819                         if (err < 0)
 820                                 goto out;
 821                 }
 822         }
 823         err = 1;
 824 out:
 825         read_unlock(&dn_fib_tables_lock);
 826         return err;
 827 }
 828
 829
 830 struct dn_fib_table *dn_fib_get_table(u32 n, int create)
 831 {
 832         struct dn_fib_table *t;
 833         unsigned int h;
 834
 835         if (n < RT_TABLE_MIN)
 836                 return NULL;
 837
 838         if (n > RT_TABLE_MAX)
 839                 return NULL;
 840
 841         h = n & (DN_FIB_TABLE_HASHSZ - 1);
 842         rcu_read_lock();
 843         hlist_for_each_entry_rcu(t, &dn_fib_table_hash[h], hlist) {
 844                 if (t->n == n) {
 845                         rcu_read_unlock();
 846                         return t;
 847                 }
 848         }
 849         rcu_read_unlock();
 850
 851         if (!create)
 852                 return NULL;
 853
 854         if (in_interrupt()) {
 855                 net_dbg_ratelimited("DECnet: BUG! Attempt to create routing table from interrupt\n");
 856                 return NULL;
 857         }
 858
 859         t = kzalloc(sizeof(struct dn_fib_table) + sizeof(struct dn_hash),
 860                     GFP_KERNEL);
 861         if (t == NULL)
 862                 return NULL;
 863
 864         t->n = n;
 865         t->insert = dn_fib_table_insert;
 866         t->delete = dn_fib_table_delete;
 867         t->lookup = dn_fib_table_lookup;
 868         t->flush  = dn_fib_table_flush;
 869         t->dump = dn_fib_table_dump;
 870         hlist_add_head_rcu(&t->hlist, &dn_fib_table_hash[h]);
 871
 872         return t;
 873 }
 874
 875 struct dn_fib_table *dn_fib_empty_table(void)
 876 {
 877         u32 id;
 878
 879         for(id = RT_TABLE_MIN; id <= RT_TABLE_MAX; id++)
 880                 if (dn_fib_get_table(id, 0) == NULL)
 881                         return dn_fib_get_table(id, 1);
 882         return NULL;
 883 }
 884
 885 void dn_fib_flush(void)
 886 {
 887         int flushed = 0;
 888         struct dn_fib_table *tb;
 889         unsigned int h;
 890
 891         for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
 892                 hlist_for_each_entry(tb, &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 *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, 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 }