net/decnet/dn_table.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * DECnet       An implementation of the DECnet protocol suite for the LINUX
   4  *              operating system.  DECnet is implemented using the  BSD Socket
   5  *              interface as the means of communication with the user level.
   6  *
   7  *              DECnet Routing Forwarding Information Base (Routing Tables)
   8  *
   9  * Author:      Steve Whitehouse <SteveW@ACM.org>
  10  *              Mostly copied from the IPv4 routing code
  11  *
  12  *
  13  * Changes:
  14  *
  15  */
  16 #include <linux/string.h>
  17 #include <linux/net.h>
  18 #include <linux/socket.h>
  19 #include <linux/slab.h>
  20 #include <linux/sockios.h>
  21 #include <linux/init.h>
  22 #include <linux/skbuff.h>
  23 #include <linux/rtnetlink.h>
  24 #include <linux/proc_fs.h>
  25 #include <linux/netdevice.h>
  26 #include <linux/timer.h>
  27 #include <linux/spinlock.h>
  28 #include <linux/atomic.h>
  29 #include <linux/uaccess.h>
  30 #include <linux/route.h> /* RTF_xxx */
  31 #include <net/neighbour.h>
  32 #include <net/netlink.h>
  33 #include <net/tcp.h>
  34 #include <net/dst.h>
  35 #include <net/flow.h>
  36 #include <net/fib_rules.h>
  37 #include <net/dn.h>
  38 #include <net/dn_route.h>
  39 #include <net/dn_fib.h>
  40 #include <net/dn_neigh.h>
  41 #include <net/dn_dev.h>
  42
  43 struct dn_zone
  44 {
  45         struct dn_zone          *dz_next;
  46         struct dn_fib_node      **dz_hash;
  47         int                     dz_nent;
  48         int                     dz_divisor;
  49         u32                     dz_hashmask;
  50 #define DZ_HASHMASK(dz) ((dz)->dz_hashmask)
  51         int                     dz_order;
  52         __le16                  dz_mask;
  53 #define DZ_MASK(dz)     ((dz)->dz_mask)
  54 };
  55
  56 struct dn_hash
  57 {
  58         struct dn_zone  *dh_zones[17];
  59         struct dn_zone  *dh_zone_list;
  60 };
  61
  62 #define dz_key_0(key)           ((key).datum = 0)
  63
  64 #define for_nexthops(fi) { int nhsel; const struct dn_fib_nh *nh;\
  65         for(nhsel = 0, nh = (fi)->fib_nh; nhsel < (fi)->fib_nhs; nh++, nhsel++)
  66
  67 #define endfor_nexthops(fi) }
  68
  69 #define DN_MAX_DIVISOR 1024
  70 #define DN_S_ZOMBIE 1
  71 #define DN_S_ACCESSED 2
  72
  73 #define DN_FIB_SCAN(f, fp) \
  74 for( ; ((f) = *(fp)) != NULL; (fp) = &(f)->fn_next)
  75
  76 #define DN_FIB_SCAN_KEY(f, fp, key) \
  77 for( ; ((f) = *(fp)) != NULL && dn_key_eq((f)->fn_key, (key)); (fp) = &(f)->fn_next)
  78
  79 #define RT_TABLE_MIN 1
  80 #define DN_FIB_TABLE_HASHSZ 256
  81 static struct hlist_head dn_fib_table_hash[DN_FIB_TABLE_HASHSZ];
  82 static DEFINE_RWLOCK(dn_fib_tables_lock);
  83
  84 static struct kmem_cache *dn_hash_kmem __read_mostly;
  85 static int dn_fib_hash_zombies;
  86
  87 static inline dn_fib_idx_t dn_hash(dn_fib_key_t key, struct dn_zone *dz)
  88 {
  89         u16 h = le16_to_cpu(key.datum)>>(16 - dz->dz_order);
  90         h ^= (h >> 10);
  91         h ^= (h >> 6);
  92         h &= DZ_HASHMASK(dz);
  93         return *(dn_fib_idx_t *)&h;
  94 }
  95
  96 static inline dn_fib_key_t dz_key(__le16 dst, struct dn_zone *dz)
  97 {
  98         dn_fib_key_t k;
  99         k.datum = dst & DZ_MASK(dz);
 100         return k;
 101 }
 102
 103 static inline struct dn_fib_node **dn_chain_p(dn_fib_key_t key, struct dn_zone *dz)
 104 {
 105         return &dz->dz_hash[dn_hash(key, dz).datum];
 106 }
 107
 108 static inline struct dn_fib_node *dz_chain(dn_fib_key_t key, struct dn_zone *dz)
 109 {
 110         return dz->dz_hash[dn_hash(key, dz).datum];
 111 }
 112
 113 static inline int dn_key_eq(dn_fib_key_t a, dn_fib_key_t b)
 114 {
 115         return a.datum == b.datum;
 116 }
 117
 118 static inline int dn_key_leq(dn_fib_key_t a, dn_fib_key_t b)
 119 {
 120         return a.datum <= b.datum;
 121 }
 122
 123 static inline void dn_rebuild_zone(struct dn_zone *dz,
 124                                    struct dn_fib_node **old_ht,
 125                                    int old_divisor)
 126 {
 127         struct dn_fib_node *f, **fp, *next;
 128         int i;
 129
 130         for(i = 0; i < old_divisor; i++) {
 131                 for(f = old_ht[i]; f; f = next) {
 132                         next = f->fn_next;
 133                         for(fp = dn_chain_p(f->fn_key, dz);
 134                                 *fp && dn_key_leq((*fp)->fn_key, f->fn_key);
 135                                 fp = &(*fp)->fn_next)
 136                                 /* NOTHING */;
 137                         f->fn_next = *fp;
 138                         *fp = f;
 139                 }
 140         }
 141 }
 142
 143 static void dn_rehash_zone(struct dn_zone *dz)
 144 {
 145         struct dn_fib_node **ht, **old_ht;
 146         int old_divisor, new_divisor;
 147         u32 new_hashmask;
 148
 149         old_divisor = dz->dz_divisor;
 150
 151         switch (old_divisor) {
 152         case 16:
 153                 new_divisor = 256;
 154                 new_hashmask = 0xFF;
 155                 break;
 156         default:
 157                 printk(KERN_DEBUG "DECnet: dn_rehash_zone: BUG! %d\n",
 158                        old_divisor);
 159         case 256:
 160                 new_divisor = 1024;
 161                 new_hashmask = 0x3FF;
 162                 break;
 163         }
 164
 165         ht = kcalloc(new_divisor, sizeof(struct dn_fib_node*), GFP_KERNEL);
 166         if (ht == NULL)
 167                 return;
 168
 169         write_lock_bh(&dn_fib_tables_lock);
 170         old_ht = dz->dz_hash;
 171         dz->dz_hash = ht;
 172         dz->dz_hashmask = new_hashmask;
 173         dz->dz_divisor = new_divisor;
 174         dn_rebuild_zone(dz, old_ht, old_divisor);
 175         write_unlock_bh(&dn_fib_tables_lock);
 176         kfree(old_ht);
 177 }
 178
 179 static void dn_free_node(struct dn_fib_node *f)
 180 {
 181         dn_fib_release_info(DN_FIB_INFO(f));
 182         kmem_cache_free(dn_hash_kmem, f);
 183 }
 184
 185
 186 static struct dn_zone *dn_new_zone(struct dn_hash *table, int z)
 187 {
 188         int i;
 189         struct dn_zone *dz = kzalloc(sizeof(struct dn_zone), GFP_KERNEL);
 190         if (!dz)
 191                 return NULL;
 192
 193         if (z) {
 194                 dz->dz_divisor = 16;
 195                 dz->dz_hashmask = 0x0F;
 196         } else {
 197                 dz->dz_divisor = 1;
 198                 dz->dz_hashmask = 0;
 199         }
 200
 201         dz->dz_hash = kcalloc(dz->dz_divisor, sizeof(struct dn_fib_node *), GFP_KERNEL);
 202         if (!dz->dz_hash) {
 203                 kfree(dz);
 204                 return NULL;
 205         }
 206
 207         dz->dz_order = z;
 208         dz->dz_mask = dnet_make_mask(z);
 209
 210         for(i = z + 1; i <= 16; i++)
 211                 if (table->dh_zones[i])
 212                         break;
 213
 214         write_lock_bh(&dn_fib_tables_lock);
 215         if (i>16) {
 216                 dz->dz_next = table->dh_zone_list;
 217                 table->dh_zone_list = dz;
 218         } else {
 219                 dz->dz_next = table->dh_zones[i]->dz_next;
 220                 table->dh_zones[i]->dz_next = dz;
 221         }
 222         table->dh_zones[z] = dz;
 223         write_unlock_bh(&dn_fib_tables_lock);
 224         return dz;
 225 }
 226
 227
 228 static int dn_fib_nh_match(struct rtmsg *r, struct nlmsghdr *nlh, struct nlattr *attrs[], struct dn_fib_info *fi)
 229 {
 230         struct rtnexthop *nhp;
 231         int nhlen;
 232
 233         if (attrs[RTA_PRIORITY] &&
 234             nla_get_u32(attrs[RTA_PRIORITY]) != fi->fib_priority)
 235                 return 1;
 236
 237         if (attrs[RTA_OIF] || attrs[RTA_GATEWAY]) {
 238                 if ((!attrs[RTA_OIF] || nla_get_u32(attrs[RTA_OIF]) == fi->fib_nh->nh_oif) &&
 239                     (!attrs[RTA_GATEWAY]  || nla_get_le16(attrs[RTA_GATEWAY]) != fi->fib_nh->nh_gw))
 240                         return 0;
 241                 return 1;
 242         }
 243
 244         if (!attrs[RTA_MULTIPATH])
 245                 return 0;
 246
 247         nhp = nla_data(attrs[RTA_MULTIPATH]);
 248         nhlen = nla_len(attrs[RTA_MULTIPATH]);
 249
 250         for_nexthops(fi) {
 251                 int attrlen = nhlen - sizeof(struct rtnexthop);
 252                 __le16 gw;
 253
 254                 if (attrlen < 0 || (nhlen -= nhp->rtnh_len) < 0)
 255                         return -EINVAL;
 256                 if (nhp->rtnh_ifindex && nhp->rtnh_ifindex != nh->nh_oif)
 257                         return 1;
 258                 if (attrlen) {
 259                         struct nlattr *gw_attr;
 260
 261                         gw_attr = nla_find((struct nlattr *) (nhp + 1), attrlen, RTA_GATEWAY);
 262                         gw = gw_attr ? nla_get_le16(gw_attr) : 0;
 263
 264                         if (gw && gw != nh->nh_gw)
 265                                 return 1;
 266                 }
 267                 nhp = RTNH_NEXT(nhp);
 268         } endfor_nexthops(fi);
 269
 270         return 0;
 271 }
 272
 273 static inline size_t dn_fib_nlmsg_size(struct dn_fib_info *fi)
 274 {
 275         size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg))
 276                          + nla_total_size(4) /* RTA_TABLE */
 277                          + nla_total_size(2) /* RTA_DST */
 278                          + nla_total_size(4) /* RTA_PRIORITY */
 279                          + nla_total_size(TCP_CA_NAME_MAX); /* RTAX_CC_ALGO */
 280
 281         /* space for nested metrics */
 282         payload += nla_total_size((RTAX_MAX * nla_total_size(4)));
 283
 284         if (fi->fib_nhs) {
 285                 /* Also handles the special case fib_nhs == 1 */
 286
 287                 /* each nexthop is packed in an attribute */
 288                 size_t nhsize = nla_total_size(sizeof(struct rtnexthop));
 289
 290                 /* may contain a gateway attribute */
 291                 nhsize += nla_total_size(4);
 292
 293                 /* all nexthops are packed in a nested attribute */
 294                 payload += nla_total_size(fi->fib_nhs * nhsize);
 295         }
 296
 297         return payload;
 298 }
 299
 300 static int dn_fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event,
 301                         u32 tb_id, u8 type, u8 scope, void *dst, int dst_len,
 302                         struct dn_fib_info *fi, unsigned int flags)
 303 {
 304         struct rtmsg *rtm;
 305         struct nlmsghdr *nlh;
 306
 307         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags);
 308         if (!nlh)
 309                 return -EMSGSIZE;
 310
 311         rtm = nlmsg_data(nlh);
 312         rtm->rtm_family = AF_DECnet;
 313         rtm->rtm_dst_len = dst_len;
 314         rtm->rtm_src_len = 0;
 315         rtm->rtm_tos = 0;
 316         rtm->rtm_table = tb_id;
 317         rtm->rtm_flags = fi->fib_flags;
 318         rtm->rtm_scope = scope;
 319         rtm->rtm_type  = type;
 320         rtm->rtm_protocol = fi->fib_protocol;
 321
 322         if (nla_put_u32(skb, RTA_TABLE, tb_id) < 0)
 323                 goto errout;
 324
 325         if (rtm->rtm_dst_len &&
 326             nla_put(skb, RTA_DST, 2, dst) < 0)
 327                 goto errout;
 328
 329         if (fi->fib_priority &&
 330             nla_put_u32(skb, RTA_PRIORITY, fi->fib_priority) < 0)
 331                 goto errout;
 332
 333         if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0)
 334                 goto errout;
 335
 336         if (fi->fib_nhs == 1) {
 337                 if (fi->fib_nh->nh_gw &&
 338                     nla_put_le16(skb, RTA_GATEWAY, fi->fib_nh->nh_gw) < 0)
 339                         goto errout;
 340
 341                 if (fi->fib_nh->nh_oif &&
 342                     nla_put_u32(skb, RTA_OIF, fi->fib_nh->nh_oif) < 0)
 343                         goto errout;
 344         }
 345
 346         if (fi->fib_nhs > 1) {
 347                 struct rtnexthop *nhp;
 348                 struct nlattr *mp_head;
 349
 350                 if (!(mp_head = nla_nest_start(skb, RTA_MULTIPATH)))
 351                         goto errout;
 352
 353                 for_nexthops(fi) {
 354                         if (!(nhp = nla_reserve_nohdr(skb, sizeof(*nhp))))
 355                                 goto errout;
 356
 357                         nhp->rtnh_flags = nh->nh_flags & 0xFF;
 358                         nhp->rtnh_hops = nh->nh_weight - 1;
 359                         nhp->rtnh_ifindex = nh->nh_oif;
 360
 361                         if (nh->nh_gw &&
 362                             nla_put_le16(skb, RTA_GATEWAY, nh->nh_gw) < 0)
 363                                 goto errout;
 364
 365                         nhp->rtnh_len = skb_tail_pointer(skb) - (unsigned char *)nhp;
 366                 } endfor_nexthops(fi);
 367
 368                 nla_nest_end(skb, mp_head);
 369         }
 370
 371         nlmsg_end(skb, nlh);
 372         return 0;
 373
 374 errout:
 375         nlmsg_cancel(skb, nlh);
 376         return -EMSGSIZE;
 377 }
 378
 379
 380 static void dn_rtmsg_fib(int event, struct dn_fib_node *f, int z, u32 tb_id,
 381                         struct nlmsghdr *nlh, struct netlink_skb_parms *req)
 382 {
 383         struct sk_buff *skb;
 384         u32 portid = req ? req->portid : 0;
 385         int err = -ENOBUFS;
 386
 387         skb = nlmsg_new(dn_fib_nlmsg_size(DN_FIB_INFO(f)), GFP_KERNEL);
 388         if (skb == NULL)
 389                 goto errout;
 390
 391         err = dn_fib_dump_info(skb, portid, nlh->nlmsg_seq, event, tb_id,
 392                                f->fn_type, f->fn_scope, &f->fn_key, z,
 393                                DN_FIB_INFO(f), 0);
 394         if (err < 0) {
 395                 /* -EMSGSIZE implies BUG in dn_fib_nlmsg_size() */
 396                 WARN_ON(err == -EMSGSIZE);
 397                 kfree_skb(skb);
 398                 goto errout;
 399         }
 400         rtnl_notify(skb, &init_net, portid, RTNLGRP_DECnet_ROUTE, nlh, GFP_KERNEL);
 401         return;
 402 errout:
 403         if (err < 0)
 404                 rtnl_set_sk_err(&init_net, RTNLGRP_DECnet_ROUTE, err);
 405 }
 406
 407 static __inline__ int dn_hash_dump_bucket(struct sk_buff *skb,
 408                                 struct netlink_callback *cb,
 409                                 struct dn_fib_table *tb,
 410                                 struct dn_zone *dz,
 411                                 struct dn_fib_node *f)
 412 {
 413         int i, s_i;
 414
 415         s_i = cb->args[4];
 416         for(i = 0; f; i++, f = f->fn_next) {
 417                 if (i < s_i)
 418                         continue;
 419                 if (f->fn_state & DN_S_ZOMBIE)
 420                         continue;
 421                 if (dn_fib_dump_info(skb, NETLINK_CB(cb->skb).portid,
 422                                 cb->nlh->nlmsg_seq,
 423                                 RTM_NEWROUTE,
 424                                 tb->n,
 425                                 (f->fn_state & DN_S_ZOMBIE) ? 0 : f->fn_type,
 426                                 f->fn_scope, &f->fn_key, dz->dz_order,
 427                                 f->fn_info, NLM_F_MULTI) < 0) {
 428                         cb->args[4] = i;
 429                         return -1;
 430                 }
 431         }
 432         cb->args[4] = i;
 433         return skb->len;
 434 }
 435
 436 static __inline__ int dn_hash_dump_zone(struct sk_buff *skb,
 437                                 struct netlink_callback *cb,
 438                                 struct dn_fib_table *tb,
 439                                 struct dn_zone *dz)
 440 {
 441         int h, s_h;
 442
 443         s_h = cb->args[3];
 444         for(h = 0; h < dz->dz_divisor; h++) {
 445                 if (h < s_h)
 446                         continue;
 447                 if (h > s_h)
 448                         memset(&cb->args[4], 0, sizeof(cb->args) - 4*sizeof(cb->args[0]));
 449                 if (dz->dz_hash == NULL || dz->dz_hash[h] == NULL)
 450                         continue;
 451                 if (dn_hash_dump_bucket(skb, cb, tb, dz, dz->dz_hash[h]) < 0) {
 452                         cb->args[3] = h;
 453                         return -1;
 454                 }
 455         }
 456         cb->args[3] = h;
 457         return skb->len;
 458 }
 459
 460 static int dn_fib_table_dump(struct dn_fib_table *tb, struct sk_buff *skb,
 461                                 struct netlink_callback *cb)
 462 {
 463         int m, s_m;
 464         struct dn_zone *dz;
 465         struct dn_hash *table = (struct dn_hash *)tb->data;
 466
 467         s_m = cb->args[2];
 468         read_lock(&dn_fib_tables_lock);
 469         for(dz = table->dh_zone_list, m = 0; dz; dz = dz->dz_next, m++) {
 470                 if (m < s_m)
 471                         continue;
 472                 if (m > s_m)
 473                         memset(&cb->args[3], 0, sizeof(cb->args) - 3*sizeof(cb->args[0]));
 474
 475                 if (dn_hash_dump_zone(skb, cb, tb, dz) < 0) {
 476                         cb->args[2] = m;
 477                         read_unlock(&dn_fib_tables_lock);
 478                         return -1;
 479                 }
 480         }
 481         read_unlock(&dn_fib_tables_lock);
 482         cb->args[2] = m;
 483
 484         return skb->len;
 485 }
 486
 487 int dn_fib_dump(struct sk_buff *skb, struct netlink_callback *cb)
 488 {
 489         struct net *net = sock_net(skb->sk);
 490         unsigned int h, s_h;
 491         unsigned int e = 0, s_e;
 492         struct dn_fib_table *tb;
 493         int dumped = 0;
 494
 495         if (!net_eq(net, &init_net))
 496                 return 0;
 497
 498         if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
 499                 ((struct rtmsg *)nlmsg_data(cb->nlh))->rtm_flags&RTM_F_CLONED)
 500                         return dn_cache_dump(skb, cb);
 501
 502         s_h = cb->args[0];
 503         s_e = cb->args[1];
 504
 505         for (h = s_h; h < DN_FIB_TABLE_HASHSZ; h++, s_h = 0) {
 506                 e = 0;
 507                 hlist_for_each_entry(tb, &dn_fib_table_hash[h], hlist) {
 508                         if (e < s_e)
 509                                 goto next;
 510                         if (dumped)
 511                                 memset(&cb->args[2], 0, sizeof(cb->args) -
 512                                                  2 * sizeof(cb->args[0]));
 513                         if (tb->dump(tb, skb, cb) < 0)
 514                                 goto out;
 515                         dumped = 1;
 516 next:
 517                         e++;
 518                 }
 519         }
 520 out:
 521         cb->args[1] = e;
 522         cb->args[0] = h;
 523
 524         return skb->len;
 525 }
 526
 527 static int dn_fib_table_insert(struct dn_fib_table *tb, struct rtmsg *r, struct nlattr *attrs[],
 528                                struct nlmsghdr *n, struct netlink_skb_parms *req)
 529 {
 530         struct dn_hash *table = (struct dn_hash *)tb->data;
 531         struct dn_fib_node *new_f, *f, **fp, **del_fp;
 532         struct dn_zone *dz;
 533         struct dn_fib_info *fi;
 534         int z = r->rtm_dst_len;
 535         int type = r->rtm_type;
 536         dn_fib_key_t key;
 537         int err;
 538
 539         if (z > 16)
 540                 return -EINVAL;
 541
 542         dz = table->dh_zones[z];
 543         if (!dz && !(dz = dn_new_zone(table, z)))
 544                 return -ENOBUFS;
 545
 546         dz_key_0(key);
 547         if (attrs[RTA_DST]) {
 548                 __le16 dst = nla_get_le16(attrs[RTA_DST]);
 549                 if (dst & ~DZ_MASK(dz))
 550                         return -EINVAL;
 551                 key = dz_key(dst, dz);
 552         }
 553
 554         if ((fi = dn_fib_create_info(r, attrs, n, &err)) == NULL)
 555                 return err;
 556
 557         if (dz->dz_nent > (dz->dz_divisor << 2) &&
 558                         dz->dz_divisor > DN_MAX_DIVISOR &&
 559                         (z==16 || (1<<z) > dz->dz_divisor))
 560                 dn_rehash_zone(dz);
 561
 562         fp = dn_chain_p(key, dz);
 563
 564         DN_FIB_SCAN(f, fp) {
 565                 if (dn_key_leq(key, f->fn_key))
 566                         break;
 567         }
 568
 569         del_fp = NULL;
 570
 571         if (f && (f->fn_state & DN_S_ZOMBIE) &&
 572                         dn_key_eq(f->fn_key, key)) {
 573                 del_fp = fp;
 574                 fp = &f->fn_next;
 575                 f = *fp;
 576                 goto create;
 577         }
 578
 579         DN_FIB_SCAN_KEY(f, fp, key) {
 580                 if (fi->fib_priority <= DN_FIB_INFO(f)->fib_priority)
 581                         break;
 582         }
 583
 584         if (f && dn_key_eq(f->fn_key, key) &&
 585                         fi->fib_priority == DN_FIB_INFO(f)->fib_priority) {
 586                 struct dn_fib_node **ins_fp;
 587
 588                 err = -EEXIST;
 589                 if (n->nlmsg_flags & NLM_F_EXCL)
 590                         goto out;
 591
 592                 if (n->nlmsg_flags & NLM_F_REPLACE) {
 593                         del_fp = fp;
 594                         fp = &f->fn_next;
 595                         f = *fp;
 596                         goto replace;
 597                 }
 598
 599                 ins_fp = fp;
 600                 err = -EEXIST;
 601
 602                 DN_FIB_SCAN_KEY(f, fp, key) {
 603                         if (fi->fib_priority != DN_FIB_INFO(f)->fib_priority)
 604                                 break;
 605                         if (f->fn_type == type &&
 606                             f->fn_scope == r->rtm_scope &&
 607                             DN_FIB_INFO(f) == fi)
 608                                 goto out;
 609                 }
 610
 611                 if (!(n->nlmsg_flags & NLM_F_APPEND)) {
 612                         fp = ins_fp;
 613                         f = *fp;
 614                 }
 615         }
 616
 617 create:
 618         err = -ENOENT;
 619         if (!(n->nlmsg_flags & NLM_F_CREATE))
 620                 goto out;
 621
 622 replace:
 623         err = -ENOBUFS;
 624         new_f = kmem_cache_zalloc(dn_hash_kmem, GFP_KERNEL);
 625         if (new_f == NULL)
 626                 goto out;
 627
 628         new_f->fn_key = key;
 629         new_f->fn_type = type;
 630         new_f->fn_scope = r->rtm_scope;
 631         DN_FIB_INFO(new_f) = fi;
 632
 633         new_f->fn_next = f;
 634         write_lock_bh(&dn_fib_tables_lock);
 635         *fp = new_f;
 636         write_unlock_bh(&dn_fib_tables_lock);
 637         dz->dz_nent++;
 638
 639         if (del_fp) {
 640                 f = *del_fp;
 641                 write_lock_bh(&dn_fib_tables_lock);
 642                 *del_fp = f->fn_next;
 643                 write_unlock_bh(&dn_fib_tables_lock);
 644
 645                 if (!(f->fn_state & DN_S_ZOMBIE))
 646                         dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 647                 if (f->fn_state & DN_S_ACCESSED)
 648                         dn_rt_cache_flush(-1);
 649                 dn_free_node(f);
 650                 dz->dz_nent--;
 651         } else {
 652                 dn_rt_cache_flush(-1);
 653         }
 654
 655         dn_rtmsg_fib(RTM_NEWROUTE, new_f, z, tb->n, n, req);
 656
 657         return 0;
 658 out:
 659         dn_fib_release_info(fi);
 660         return err;
 661 }
 662
 663
 664 static int dn_fib_table_delete(struct dn_fib_table *tb, struct rtmsg *r, struct nlattr *attrs[],
 665                                struct nlmsghdr *n, struct netlink_skb_parms *req)
 666 {
 667         struct dn_hash *table = (struct dn_hash*)tb->data;
 668         struct dn_fib_node **fp, **del_fp, *f;
 669         int z = r->rtm_dst_len;
 670         struct dn_zone *dz;
 671         dn_fib_key_t key;
 672         int matched;
 673
 674
 675         if (z > 16)
 676                 return -EINVAL;
 677
 678         if ((dz = table->dh_zones[z]) == NULL)
 679                 return -ESRCH;
 680
 681         dz_key_0(key);
 682         if (attrs[RTA_DST]) {
 683                 __le16 dst = nla_get_le16(attrs[RTA_DST]);
 684                 if (dst & ~DZ_MASK(dz))
 685                         return -EINVAL;
 686                 key = dz_key(dst, dz);
 687         }
 688
 689         fp = dn_chain_p(key, dz);
 690
 691         DN_FIB_SCAN(f, fp) {
 692                 if (dn_key_eq(f->fn_key, key))
 693                         break;
 694                 if (dn_key_leq(key, f->fn_key))
 695                         return -ESRCH;
 696         }
 697
 698         matched = 0;
 699         del_fp = NULL;
 700         DN_FIB_SCAN_KEY(f, fp, key) {
 701                 struct dn_fib_info *fi = DN_FIB_INFO(f);
 702
 703                 if (f->fn_state & DN_S_ZOMBIE)
 704                         return -ESRCH;
 705
 706                 matched++;
 707
 708                 if (del_fp == NULL &&
 709                                 (!r->rtm_type || f->fn_type == r->rtm_type) &&
 710                                 (r->rtm_scope == RT_SCOPE_NOWHERE || f->fn_scope == r->rtm_scope) &&
 711                                 (!r->rtm_protocol ||
 712                                         fi->fib_protocol == r->rtm_protocol) &&
 713                                 dn_fib_nh_match(r, n, attrs, fi) == 0)
 714                         del_fp = fp;
 715         }
 716
 717         if (del_fp) {
 718                 f = *del_fp;
 719                 dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 720
 721                 if (matched != 1) {
 722                         write_lock_bh(&dn_fib_tables_lock);
 723                         *del_fp = f->fn_next;
 724                         write_unlock_bh(&dn_fib_tables_lock);
 725
 726                         if (f->fn_state & DN_S_ACCESSED)
 727                                 dn_rt_cache_flush(-1);
 728                         dn_free_node(f);
 729                         dz->dz_nent--;
 730                 } else {
 731                         f->fn_state |= DN_S_ZOMBIE;
 732                         if (f->fn_state & DN_S_ACCESSED) {
 733                                 f->fn_state &= ~DN_S_ACCESSED;
 734                                 dn_rt_cache_flush(-1);
 735                         }
 736                         if (++dn_fib_hash_zombies > 128)
 737                                 dn_fib_flush();
 738                 }
 739
 740                 return 0;
 741         }
 742
 743         return -ESRCH;
 744 }
 745
 746 static inline int dn_flush_list(struct dn_fib_node **fp, int z, struct dn_hash *table)
 747 {
 748         int found = 0;
 749         struct dn_fib_node *f;
 750
 751         while((f = *fp) != NULL) {
 752                 struct dn_fib_info *fi = DN_FIB_INFO(f);
 753
 754                 if (fi && ((f->fn_state & DN_S_ZOMBIE) || (fi->fib_flags & RTNH_F_DEAD))) {
 755                         write_lock_bh(&dn_fib_tables_lock);
 756                         *fp = f->fn_next;
 757                         write_unlock_bh(&dn_fib_tables_lock);
 758
 759                         dn_free_node(f);
 760                         found++;
 761                         continue;
 762                 }
 763                 fp = &f->fn_next;
 764         }
 765
 766         return found;
 767 }
 768
 769 static int dn_fib_table_flush(struct dn_fib_table *tb)
 770 {
 771         struct dn_hash *table = (struct dn_hash *)tb->data;
 772         struct dn_zone *dz;
 773         int found = 0;
 774
 775         dn_fib_hash_zombies = 0;
 776         for(dz = table->dh_zone_list; dz; dz = dz->dz_next) {
 777                 int i;
 778                 int tmp = 0;
 779                 for(i = dz->dz_divisor-1; i >= 0; i--)
 780                         tmp += dn_flush_list(&dz->dz_hash[i], dz->dz_order, table);
 781                 dz->dz_nent -= tmp;
 782                 found += tmp;
 783         }
 784
 785         return found;
 786 }
 787
 788 static int dn_fib_table_lookup(struct dn_fib_table *tb, const struct flowidn *flp, struct dn_fib_res *res)
 789 {
 790         int err;
 791         struct dn_zone *dz;
 792         struct dn_hash *t = (struct dn_hash *)tb->data;
 793
 794         read_lock(&dn_fib_tables_lock);
 795         for(dz = t->dh_zone_list; dz; dz = dz->dz_next) {
 796                 struct dn_fib_node *f;
 797                 dn_fib_key_t k = dz_key(flp->daddr, dz);
 798
 799                 for(f = dz_chain(k, dz); f; f = f->fn_next) {
 800                         if (!dn_key_eq(k, f->fn_key)) {
 801                                 if (dn_key_leq(k, f->fn_key))
 802                                         break;
 803                                 else
 804                                         continue;
 805                         }
 806
 807                         f->fn_state |= DN_S_ACCESSED;
 808
 809                         if (f->fn_state&DN_S_ZOMBIE)
 810                                 continue;
 811
 812                         if (f->fn_scope < flp->flowidn_scope)
 813                                 continue;
 814
 815                         err = dn_fib_semantic_match(f->fn_type, DN_FIB_INFO(f), flp, res);
 816
 817                         if (err == 0) {
 818                                 res->type = f->fn_type;
 819                                 res->scope = f->fn_scope;
 820                                 res->prefixlen = dz->dz_order;
 821                                 goto out;
 822                         }
 823                         if (err < 0)
 824                                 goto out;
 825                 }
 826         }
 827         err = 1;
 828 out:
 829         read_unlock(&dn_fib_tables_lock);
 830         return err;
 831 }
 832
 833
 834 struct dn_fib_table *dn_fib_get_table(u32 n, int create)
 835 {
 836         struct dn_fib_table *t;
 837         unsigned int h;
 838
 839         if (n < RT_TABLE_MIN)
 840                 return NULL;
 841
 842         if (n > RT_TABLE_MAX)
 843                 return NULL;
 844
 845         h = n & (DN_FIB_TABLE_HASHSZ - 1);
 846         rcu_read_lock();
 847         hlist_for_each_entry_rcu(t, &dn_fib_table_hash[h], hlist) {
 848                 if (t->n == n) {
 849                         rcu_read_unlock();
 850                         return t;
 851                 }
 852         }
 853         rcu_read_unlock();
 854
 855         if (!create)
 856                 return NULL;
 857
 858         if (in_interrupt()) {
 859                 net_dbg_ratelimited("DECnet: BUG! Attempt to create routing table from interrupt\n");
 860                 return NULL;
 861         }
 862
 863         t = kzalloc(sizeof(struct dn_fib_table) + sizeof(struct dn_hash),
 864                     GFP_KERNEL);
 865         if (t == NULL)
 866                 return NULL;
 867
 868         t->n = n;
 869         t->insert = dn_fib_table_insert;
 870         t->delete = dn_fib_table_delete;
 871         t->lookup = dn_fib_table_lookup;
 872         t->flush  = dn_fib_table_flush;
 873         t->dump = dn_fib_table_dump;
 874         hlist_add_head_rcu(&t->hlist, &dn_fib_table_hash[h]);
 875
 876         return t;
 877 }
 878
 879 struct dn_fib_table *dn_fib_empty_table(void)
 880 {
 881         u32 id;
 882
 883         for(id = RT_TABLE_MIN; id <= RT_TABLE_MAX; id++)
 884                 if (dn_fib_get_table(id, 0) == NULL)
 885                         return dn_fib_get_table(id, 1);
 886         return NULL;
 887 }
 888
 889 void dn_fib_flush(void)
 890 {
 891         int flushed = 0;
 892         struct dn_fib_table *tb;
 893         unsigned int h;
 894
 895         for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
 896                 hlist_for_each_entry(tb, &dn_fib_table_hash[h], hlist)
 897                         flushed += tb->flush(tb);
 898         }
 899
 900         if (flushed)
 901                 dn_rt_cache_flush(-1);
 902 }
 903
 904 void __init dn_fib_table_init(void)
 905 {
 906         dn_hash_kmem = kmem_cache_create("dn_fib_info_cache",
 907                                         sizeof(struct dn_fib_info),
 908                                         0, SLAB_HWCACHE_ALIGN,
 909                                         NULL);
 910 }
 911
 912 void __exit dn_fib_table_cleanup(void)
 913 {
 914         struct dn_fib_table *t;
 915         struct hlist_node *next;
 916         unsigned int h;
 917
 918         write_lock(&dn_fib_tables_lock);
 919         for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
 920                 hlist_for_each_entry_safe(t, next, &dn_fib_table_hash[h],
 921                                           hlist) {
 922                         hlist_del(&t->hlist);
 923                         kfree(t);
 924                 }
 925         }
 926         write_unlock(&dn_fib_tables_lock);
 927 }