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                 fallthrough;
 160         case 256:
 161                 new_divisor = 1024;
 162                 new_hashmask = 0x3FF;
 163                 break;
 164         }
 165
 166         ht = kcalloc(new_divisor, sizeof(struct dn_fib_node*), GFP_KERNEL);
 167         if (ht == NULL)
 168                 return;
 169
 170         write_lock_bh(&dn_fib_tables_lock);
 171         old_ht = dz->dz_hash;
 172         dz->dz_hash = ht;
 173         dz->dz_hashmask = new_hashmask;
 174         dz->dz_divisor = new_divisor;
 175         dn_rebuild_zone(dz, old_ht, old_divisor);
 176         write_unlock_bh(&dn_fib_tables_lock);
 177         kfree(old_ht);
 178 }
 179
 180 static void dn_free_node(struct dn_fib_node *f)
 181 {
 182         dn_fib_release_info(DN_FIB_INFO(f));
 183         kmem_cache_free(dn_hash_kmem, f);
 184 }
 185
 186
 187 static struct dn_zone *dn_new_zone(struct dn_hash *table, int z)
 188 {
 189         int i;
 190         struct dn_zone *dz = kzalloc(sizeof(struct dn_zone), GFP_KERNEL);
 191         if (!dz)
 192                 return NULL;
 193
 194         if (z) {
 195                 dz->dz_divisor = 16;
 196                 dz->dz_hashmask = 0x0F;
 197         } else {
 198                 dz->dz_divisor = 1;
 199                 dz->dz_hashmask = 0;
 200         }
 201
 202         dz->dz_hash = kcalloc(dz->dz_divisor, sizeof(struct dn_fib_node *), GFP_KERNEL);
 203         if (!dz->dz_hash) {
 204                 kfree(dz);
 205                 return NULL;
 206         }
 207
 208         dz->dz_order = z;
 209         dz->dz_mask = dnet_make_mask(z);
 210
 211         for(i = z + 1; i <= 16; i++)
 212                 if (table->dh_zones[i])
 213                         break;
 214
 215         write_lock_bh(&dn_fib_tables_lock);
 216         if (i>16) {
 217                 dz->dz_next = table->dh_zone_list;
 218                 table->dh_zone_list = dz;
 219         } else {
 220                 dz->dz_next = table->dh_zones[i]->dz_next;
 221                 table->dh_zones[i]->dz_next = dz;
 222         }
 223         table->dh_zones[z] = dz;
 224         write_unlock_bh(&dn_fib_tables_lock);
 225         return dz;
 226 }
 227
 228
 229 static int dn_fib_nh_match(struct rtmsg *r, struct nlmsghdr *nlh, struct nlattr *attrs[], struct dn_fib_info *fi)
 230 {
 231         struct rtnexthop *nhp;
 232         int nhlen;
 233
 234         if (attrs[RTA_PRIORITY] &&
 235             nla_get_u32(attrs[RTA_PRIORITY]) != fi->fib_priority)
 236                 return 1;
 237
 238         if (attrs[RTA_OIF] || attrs[RTA_GATEWAY]) {
 239                 if ((!attrs[RTA_OIF] || nla_get_u32(attrs[RTA_OIF]) == fi->fib_nh->nh_oif) &&
 240                     (!attrs[RTA_GATEWAY]  || nla_get_le16(attrs[RTA_GATEWAY]) != fi->fib_nh->nh_gw))
 241                         return 0;
 242                 return 1;
 243         }
 244
 245         if (!attrs[RTA_MULTIPATH])
 246                 return 0;
 247
 248         nhp = nla_data(attrs[RTA_MULTIPATH]);
 249         nhlen = nla_len(attrs[RTA_MULTIPATH]);
 250
 251         for_nexthops(fi) {
 252                 int attrlen = nhlen - sizeof(struct rtnexthop);
 253                 __le16 gw;
 254
 255                 if (attrlen < 0 || (nhlen -= nhp->rtnh_len) < 0)
 256                         return -EINVAL;
 257                 if (nhp->rtnh_ifindex && nhp->rtnh_ifindex != nh->nh_oif)
 258                         return 1;
 259                 if (attrlen) {
 260                         struct nlattr *gw_attr;
 261
 262                         gw_attr = nla_find((struct nlattr *) (nhp + 1), attrlen, RTA_GATEWAY);
 263                         gw = gw_attr ? nla_get_le16(gw_attr) : 0;
 264
 265                         if (gw && gw != nh->nh_gw)
 266                                 return 1;
 267                 }
 268                 nhp = RTNH_NEXT(nhp);
 269         } endfor_nexthops(fi);
 270
 271         return 0;
 272 }
 273
 274 static inline size_t dn_fib_nlmsg_size(struct dn_fib_info *fi)
 275 {
 276         size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg))
 277                          + nla_total_size(4) /* RTA_TABLE */
 278                          + nla_total_size(2) /* RTA_DST */
 279                          + nla_total_size(4) /* RTA_PRIORITY */
 280                          + nla_total_size(TCP_CA_NAME_MAX); /* RTAX_CC_ALGO */
 281
 282         /* space for nested metrics */
 283         payload += nla_total_size((RTAX_MAX * nla_total_size(4)));
 284
 285         if (fi->fib_nhs) {
 286                 /* Also handles the special case fib_nhs == 1 */
 287
 288                 /* each nexthop is packed in an attribute */
 289                 size_t nhsize = nla_total_size(sizeof(struct rtnexthop));
 290
 291                 /* may contain a gateway attribute */
 292                 nhsize += nla_total_size(4);
 293
 294                 /* all nexthops are packed in a nested attribute */
 295                 payload += nla_total_size(fi->fib_nhs * nhsize);
 296         }
 297
 298         return payload;
 299 }
 300
 301 static int dn_fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event,
 302                         u32 tb_id, u8 type, u8 scope, void *dst, int dst_len,
 303                         struct dn_fib_info *fi, unsigned int flags)
 304 {
 305         struct rtmsg *rtm;
 306         struct nlmsghdr *nlh;
 307
 308         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags);
 309         if (!nlh)
 310                 return -EMSGSIZE;
 311
 312         rtm = nlmsg_data(nlh);
 313         rtm->rtm_family = AF_DECnet;
 314         rtm->rtm_dst_len = dst_len;
 315         rtm->rtm_src_len = 0;
 316         rtm->rtm_tos = 0;
 317         rtm->rtm_table = tb_id;
 318         rtm->rtm_flags = fi->fib_flags;
 319         rtm->rtm_scope = scope;
 320         rtm->rtm_type  = type;
 321         rtm->rtm_protocol = fi->fib_protocol;
 322
 323         if (nla_put_u32(skb, RTA_TABLE, tb_id) < 0)
 324                 goto errout;
 325
 326         if (rtm->rtm_dst_len &&
 327             nla_put(skb, RTA_DST, 2, dst) < 0)
 328                 goto errout;
 329
 330         if (fi->fib_priority &&
 331             nla_put_u32(skb, RTA_PRIORITY, fi->fib_priority) < 0)
 332                 goto errout;
 333
 334         if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0)
 335                 goto errout;
 336
 337         if (fi->fib_nhs == 1) {
 338                 if (fi->fib_nh->nh_gw &&
 339                     nla_put_le16(skb, RTA_GATEWAY, fi->fib_nh->nh_gw) < 0)
 340                         goto errout;
 341
 342                 if (fi->fib_nh->nh_oif &&
 343                     nla_put_u32(skb, RTA_OIF, fi->fib_nh->nh_oif) < 0)
 344                         goto errout;
 345         }
 346
 347         if (fi->fib_nhs > 1) {
 348                 struct rtnexthop *nhp;
 349                 struct nlattr *mp_head;
 350
 351                 mp_head = nla_nest_start_noflag(skb, RTA_MULTIPATH);
 352                 if (!mp_head)
 353                         goto errout;
 354
 355                 for_nexthops(fi) {
 356                         if (!(nhp = nla_reserve_nohdr(skb, sizeof(*nhp))))
 357                                 goto errout;
 358
 359                         nhp->rtnh_flags = nh->nh_flags & 0xFF;
 360                         nhp->rtnh_hops = nh->nh_weight - 1;
 361                         nhp->rtnh_ifindex = nh->nh_oif;
 362
 363                         if (nh->nh_gw &&
 364                             nla_put_le16(skb, RTA_GATEWAY, nh->nh_gw) < 0)
 365                                 goto errout;
 366
 367                         nhp->rtnh_len = skb_tail_pointer(skb) - (unsigned char *)nhp;
 368                 } endfor_nexthops(fi);
 369
 370                 nla_nest_end(skb, mp_head);
 371         }
 372
 373         nlmsg_end(skb, nlh);
 374         return 0;
 375
 376 errout:
 377         nlmsg_cancel(skb, nlh);
 378         return -EMSGSIZE;
 379 }
 380
 381
 382 static void dn_rtmsg_fib(int event, struct dn_fib_node *f, int z, u32 tb_id,
 383                         struct nlmsghdr *nlh, struct netlink_skb_parms *req)
 384 {
 385         struct sk_buff *skb;
 386         u32 portid = req ? req->portid : 0;
 387         int err = -ENOBUFS;
 388
 389         skb = nlmsg_new(dn_fib_nlmsg_size(DN_FIB_INFO(f)), GFP_KERNEL);
 390         if (skb == NULL)
 391                 goto errout;
 392
 393         err = dn_fib_dump_info(skb, portid, nlh->nlmsg_seq, event, tb_id,
 394                                f->fn_type, f->fn_scope, &f->fn_key, z,
 395                                DN_FIB_INFO(f), 0);
 396         if (err < 0) {
 397                 /* -EMSGSIZE implies BUG in dn_fib_nlmsg_size() */
 398                 WARN_ON(err == -EMSGSIZE);
 399                 kfree_skb(skb);
 400                 goto errout;
 401         }
 402         rtnl_notify(skb, &init_net, portid, RTNLGRP_DECnet_ROUTE, nlh, GFP_KERNEL);
 403         return;
 404 errout:
 405         if (err < 0)
 406                 rtnl_set_sk_err(&init_net, RTNLGRP_DECnet_ROUTE, err);
 407 }
 408
 409 static __inline__ int dn_hash_dump_bucket(struct sk_buff *skb,
 410                                 struct netlink_callback *cb,
 411                                 struct dn_fib_table *tb,
 412                                 struct dn_zone *dz,
 413                                 struct dn_fib_node *f)
 414 {
 415         int i, s_i;
 416
 417         s_i = cb->args[4];
 418         for(i = 0; f; i++, f = f->fn_next) {
 419                 if (i < s_i)
 420                         continue;
 421                 if (f->fn_state & DN_S_ZOMBIE)
 422                         continue;
 423                 if (dn_fib_dump_info(skb, NETLINK_CB(cb->skb).portid,
 424                                 cb->nlh->nlmsg_seq,
 425                                 RTM_NEWROUTE,
 426                                 tb->n,
 427                                 (f->fn_state & DN_S_ZOMBIE) ? 0 : f->fn_type,
 428                                 f->fn_scope, &f->fn_key, dz->dz_order,
 429                                 f->fn_info, NLM_F_MULTI) < 0) {
 430                         cb->args[4] = i;
 431                         return -1;
 432                 }
 433         }
 434         cb->args[4] = i;
 435         return skb->len;
 436 }
 437
 438 static __inline__ int dn_hash_dump_zone(struct sk_buff *skb,
 439                                 struct netlink_callback *cb,
 440                                 struct dn_fib_table *tb,
 441                                 struct dn_zone *dz)
 442 {
 443         int h, s_h;
 444
 445         s_h = cb->args[3];
 446         for(h = 0; h < dz->dz_divisor; h++) {
 447                 if (h < s_h)
 448                         continue;
 449                 if (h > s_h)
 450                         memset(&cb->args[4], 0, sizeof(cb->args) - 4*sizeof(cb->args[0]));
 451                 if (dz->dz_hash == NULL || dz->dz_hash[h] == NULL)
 452                         continue;
 453                 if (dn_hash_dump_bucket(skb, cb, tb, dz, dz->dz_hash[h]) < 0) {
 454                         cb->args[3] = h;
 455                         return -1;
 456                 }
 457         }
 458         cb->args[3] = h;
 459         return skb->len;
 460 }
 461
 462 static int dn_fib_table_dump(struct dn_fib_table *tb, struct sk_buff *skb,
 463                                 struct netlink_callback *cb)
 464 {
 465         int m, s_m;
 466         struct dn_zone *dz;
 467         struct dn_hash *table = (struct dn_hash *)tb->data;
 468
 469         s_m = cb->args[2];
 470         read_lock(&dn_fib_tables_lock);
 471         for(dz = table->dh_zone_list, m = 0; dz; dz = dz->dz_next, m++) {
 472                 if (m < s_m)
 473                         continue;
 474                 if (m > s_m)
 475                         memset(&cb->args[3], 0, sizeof(cb->args) - 3*sizeof(cb->args[0]));
 476
 477                 if (dn_hash_dump_zone(skb, cb, tb, dz) < 0) {
 478                         cb->args[2] = m;
 479                         read_unlock(&dn_fib_tables_lock);
 480                         return -1;
 481                 }
 482         }
 483         read_unlock(&dn_fib_tables_lock);
 484         cb->args[2] = m;
 485
 486         return skb->len;
 487 }
 488
 489 int dn_fib_dump(struct sk_buff *skb, struct netlink_callback *cb)
 490 {
 491         struct net *net = sock_net(skb->sk);
 492         unsigned int h, s_h;
 493         unsigned int e = 0, s_e;
 494         struct dn_fib_table *tb;
 495         int dumped = 0;
 496
 497         if (!net_eq(net, &init_net))
 498                 return 0;
 499
 500         if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
 501                 ((struct rtmsg *)nlmsg_data(cb->nlh))->rtm_flags&RTM_F_CLONED)
 502                         return dn_cache_dump(skb, cb);
 503
 504         s_h = cb->args[0];
 505         s_e = cb->args[1];
 506
 507         for (h = s_h; h < DN_FIB_TABLE_HASHSZ; h++, s_h = 0) {
 508                 e = 0;
 509                 hlist_for_each_entry(tb, &dn_fib_table_hash[h], hlist) {
 510                         if (e < s_e)
 511                                 goto next;
 512                         if (dumped)
 513                                 memset(&cb->args[2], 0, sizeof(cb->args) -
 514                                                  2 * sizeof(cb->args[0]));
 515                         if (tb->dump(tb, skb, cb) < 0)
 516                                 goto out;
 517                         dumped = 1;
 518 next:
 519                         e++;
 520                 }
 521         }
 522 out:
 523         cb->args[1] = e;
 524         cb->args[0] = h;
 525
 526         return skb->len;
 527 }
 528
 529 static int dn_fib_table_insert(struct dn_fib_table *tb, struct rtmsg *r, struct nlattr *attrs[],
 530                                struct nlmsghdr *n, struct netlink_skb_parms *req)
 531 {
 532         struct dn_hash *table = (struct dn_hash *)tb->data;
 533         struct dn_fib_node *new_f, *f, **fp, **del_fp;
 534         struct dn_zone *dz;
 535         struct dn_fib_info *fi;
 536         int z = r->rtm_dst_len;
 537         int type = r->rtm_type;
 538         dn_fib_key_t key;
 539         int err;
 540
 541         if (z > 16)
 542                 return -EINVAL;
 543
 544         dz = table->dh_zones[z];
 545         if (!dz && !(dz = dn_new_zone(table, z)))
 546                 return -ENOBUFS;
 547
 548         dz_key_0(key);
 549         if (attrs[RTA_DST]) {
 550                 __le16 dst = nla_get_le16(attrs[RTA_DST]);
 551                 if (dst & ~DZ_MASK(dz))
 552                         return -EINVAL;
 553                 key = dz_key(dst, dz);
 554         }
 555
 556         if ((fi = dn_fib_create_info(r, attrs, n, &err)) == NULL)
 557                 return err;
 558
 559         if (dz->dz_nent > (dz->dz_divisor << 2) &&
 560                         dz->dz_divisor > DN_MAX_DIVISOR &&
 561                         (z==16 || (1<<z) > dz->dz_divisor))
 562                 dn_rehash_zone(dz);
 563
 564         fp = dn_chain_p(key, dz);
 565
 566         DN_FIB_SCAN(f, fp) {
 567                 if (dn_key_leq(key, f->fn_key))
 568                         break;
 569         }
 570
 571         del_fp = NULL;
 572
 573         if (f && (f->fn_state & DN_S_ZOMBIE) &&
 574                         dn_key_eq(f->fn_key, key)) {
 575                 del_fp = fp;
 576                 fp = &f->fn_next;
 577                 f = *fp;
 578                 goto create;
 579         }
 580
 581         DN_FIB_SCAN_KEY(f, fp, key) {
 582                 if (fi->fib_priority <= DN_FIB_INFO(f)->fib_priority)
 583                         break;
 584         }
 585
 586         if (f && dn_key_eq(f->fn_key, key) &&
 587                         fi->fib_priority == DN_FIB_INFO(f)->fib_priority) {
 588                 struct dn_fib_node **ins_fp;
 589
 590                 err = -EEXIST;
 591                 if (n->nlmsg_flags & NLM_F_EXCL)
 592                         goto out;
 593
 594                 if (n->nlmsg_flags & NLM_F_REPLACE) {
 595                         del_fp = fp;
 596                         fp = &f->fn_next;
 597                         f = *fp;
 598                         goto replace;
 599                 }
 600
 601                 ins_fp = fp;
 602                 err = -EEXIST;
 603
 604                 DN_FIB_SCAN_KEY(f, fp, key) {
 605                         if (fi->fib_priority != DN_FIB_INFO(f)->fib_priority)
 606                                 break;
 607                         if (f->fn_type == type &&
 608                             f->fn_scope == r->rtm_scope &&
 609                             DN_FIB_INFO(f) == fi)
 610                                 goto out;
 611                 }
 612
 613                 if (!(n->nlmsg_flags & NLM_F_APPEND)) {
 614                         fp = ins_fp;
 615                         f = *fp;
 616                 }
 617         }
 618
 619 create:
 620         err = -ENOENT;
 621         if (!(n->nlmsg_flags & NLM_F_CREATE))
 622                 goto out;
 623
 624 replace:
 625         err = -ENOBUFS;
 626         new_f = kmem_cache_zalloc(dn_hash_kmem, GFP_KERNEL);
 627         if (new_f == NULL)
 628                 goto out;
 629
 630         new_f->fn_key = key;
 631         new_f->fn_type = type;
 632         new_f->fn_scope = r->rtm_scope;
 633         DN_FIB_INFO(new_f) = fi;
 634
 635         new_f->fn_next = f;
 636         write_lock_bh(&dn_fib_tables_lock);
 637         *fp = new_f;
 638         write_unlock_bh(&dn_fib_tables_lock);
 639         dz->dz_nent++;
 640
 641         if (del_fp) {
 642                 f = *del_fp;
 643                 write_lock_bh(&dn_fib_tables_lock);
 644                 *del_fp = f->fn_next;
 645                 write_unlock_bh(&dn_fib_tables_lock);
 646
 647                 if (!(f->fn_state & DN_S_ZOMBIE))
 648                         dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 649                 if (f->fn_state & DN_S_ACCESSED)
 650                         dn_rt_cache_flush(-1);
 651                 dn_free_node(f);
 652                 dz->dz_nent--;
 653         } else {
 654                 dn_rt_cache_flush(-1);
 655         }
 656
 657         dn_rtmsg_fib(RTM_NEWROUTE, new_f, z, tb->n, n, req);
 658
 659         return 0;
 660 out:
 661         dn_fib_release_info(fi);
 662         return err;
 663 }
 664
 665
 666 static int dn_fib_table_delete(struct dn_fib_table *tb, struct rtmsg *r, struct nlattr *attrs[],
 667                                struct nlmsghdr *n, struct netlink_skb_parms *req)
 668 {
 669         struct dn_hash *table = (struct dn_hash*)tb->data;
 670         struct dn_fib_node **fp, **del_fp, *f;
 671         int z = r->rtm_dst_len;
 672         struct dn_zone *dz;
 673         dn_fib_key_t key;
 674         int matched;
 675
 676
 677         if (z > 16)
 678                 return -EINVAL;
 679
 680         if ((dz = table->dh_zones[z]) == NULL)
 681                 return -ESRCH;
 682
 683         dz_key_0(key);
 684         if (attrs[RTA_DST]) {
 685                 __le16 dst = nla_get_le16(attrs[RTA_DST]);
 686                 if (dst & ~DZ_MASK(dz))
 687                         return -EINVAL;
 688                 key = dz_key(dst, dz);
 689         }
 690
 691         fp = dn_chain_p(key, dz);
 692
 693         DN_FIB_SCAN(f, fp) {
 694                 if (dn_key_eq(f->fn_key, key))
 695                         break;
 696                 if (dn_key_leq(key, f->fn_key))
 697                         return -ESRCH;
 698         }
 699
 700         matched = 0;
 701         del_fp = NULL;
 702         DN_FIB_SCAN_KEY(f, fp, key) {
 703                 struct dn_fib_info *fi = DN_FIB_INFO(f);
 704
 705                 if (f->fn_state & DN_S_ZOMBIE)
 706                         return -ESRCH;
 707
 708                 matched++;
 709
 710                 if (del_fp == NULL &&
 711                                 (!r->rtm_type || f->fn_type == r->rtm_type) &&
 712                                 (r->rtm_scope == RT_SCOPE_NOWHERE || f->fn_scope == r->rtm_scope) &&
 713                                 (!r->rtm_protocol ||
 714                                         fi->fib_protocol == r->rtm_protocol) &&
 715                                 dn_fib_nh_match(r, n, attrs, fi) == 0)
 716                         del_fp = fp;
 717         }
 718
 719         if (del_fp) {
 720                 f = *del_fp;
 721                 dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 722
 723                 if (matched != 1) {
 724                         write_lock_bh(&dn_fib_tables_lock);
 725                         *del_fp = f->fn_next;
 726                         write_unlock_bh(&dn_fib_tables_lock);
 727
 728                         if (f->fn_state & DN_S_ACCESSED)
 729                                 dn_rt_cache_flush(-1);
 730                         dn_free_node(f);
 731                         dz->dz_nent--;
 732                 } else {
 733                         f->fn_state |= DN_S_ZOMBIE;
 734                         if (f->fn_state & DN_S_ACCESSED) {
 735                                 f->fn_state &= ~DN_S_ACCESSED;
 736                                 dn_rt_cache_flush(-1);
 737                         }
 738                         if (++dn_fib_hash_zombies > 128)
 739                                 dn_fib_flush();
 740                 }
 741
 742                 return 0;
 743         }
 744
 745         return -ESRCH;
 746 }
 747
 748 static inline int dn_flush_list(struct dn_fib_node **fp, int z, struct dn_hash *table)
 749 {
 750         int found = 0;
 751         struct dn_fib_node *f;
 752
 753         while((f = *fp) != NULL) {
 754                 struct dn_fib_info *fi = DN_FIB_INFO(f);
 755
 756                 if (fi && ((f->fn_state & DN_S_ZOMBIE) || (fi->fib_flags & RTNH_F_DEAD))) {
 757                         write_lock_bh(&dn_fib_tables_lock);
 758                         *fp = f->fn_next;
 759                         write_unlock_bh(&dn_fib_tables_lock);
 760
 761                         dn_free_node(f);
 762                         found++;
 763                         continue;
 764                 }
 765                 fp = &f->fn_next;
 766         }
 767
 768         return found;
 769 }
 770
 771 static int dn_fib_table_flush(struct dn_fib_table *tb)
 772 {
 773         struct dn_hash *table = (struct dn_hash *)tb->data;
 774         struct dn_zone *dz;
 775         int found = 0;
 776
 777         dn_fib_hash_zombies = 0;
 778         for(dz = table->dh_zone_list; dz; dz = dz->dz_next) {
 779                 int i;
 780                 int tmp = 0;
 781                 for(i = dz->dz_divisor-1; i >= 0; i--)
 782                         tmp += dn_flush_list(&dz->dz_hash[i], dz->dz_order, table);
 783                 dz->dz_nent -= tmp;
 784                 found += tmp;
 785         }
 786
 787         return found;
 788 }
 789
 790 static int dn_fib_table_lookup(struct dn_fib_table *tb, const struct flowidn *flp, struct dn_fib_res *res)
 791 {
 792         int err;
 793         struct dn_zone *dz;
 794         struct dn_hash *t = (struct dn_hash *)tb->data;
 795
 796         read_lock(&dn_fib_tables_lock);
 797         for(dz = t->dh_zone_list; dz; dz = dz->dz_next) {
 798                 struct dn_fib_node *f;
 799                 dn_fib_key_t k = dz_key(flp->daddr, dz);
 800
 801                 for(f = dz_chain(k, dz); f; f = f->fn_next) {
 802                         if (!dn_key_eq(k, f->fn_key)) {
 803                                 if (dn_key_leq(k, f->fn_key))
 804                                         break;
 805                                 else
 806                                         continue;
 807                         }
 808
 809                         f->fn_state |= DN_S_ACCESSED;
 810
 811                         if (f->fn_state&DN_S_ZOMBIE)
 812                                 continue;
 813
 814                         if (f->fn_scope < flp->flowidn_scope)
 815                                 continue;
 816
 817                         err = dn_fib_semantic_match(f->fn_type, DN_FIB_INFO(f), flp, res);
 818
 819                         if (err == 0) {
 820                                 res->type = f->fn_type;
 821                                 res->scope = f->fn_scope;
 822                                 res->prefixlen = dz->dz_order;
 823                                 goto out;
 824                         }
 825                         if (err < 0)
 826                                 goto out;
 827                 }
 828         }
 829         err = 1;
 830 out:
 831         read_unlock(&dn_fib_tables_lock);
 832         return err;
 833 }
 834
 835
 836 struct dn_fib_table *dn_fib_get_table(u32 n, int create)
 837 {
 838         struct dn_fib_table *t;
 839         unsigned int h;
 840
 841         if (n < RT_TABLE_MIN)
 842                 return NULL;
 843
 844         if (n > RT_TABLE_MAX)
 845                 return NULL;
 846
 847         h = n & (DN_FIB_TABLE_HASHSZ - 1);
 848         rcu_read_lock();
 849         hlist_for_each_entry_rcu(t, &dn_fib_table_hash[h], hlist) {
 850                 if (t->n == n) {
 851                         rcu_read_unlock();
 852                         return t;
 853                 }
 854         }
 855         rcu_read_unlock();
 856
 857         if (!create)
 858                 return NULL;
 859
 860         if (in_interrupt()) {
 861                 net_dbg_ratelimited("DECnet: BUG! Attempt to create routing table from interrupt\n");
 862                 return NULL;
 863         }
 864
 865         t = kzalloc(sizeof(struct dn_fib_table) + sizeof(struct dn_hash),
 866                     GFP_KERNEL);
 867         if (t == NULL)
 868                 return NULL;
 869
 870         t->n = n;
 871         t->insert = dn_fib_table_insert;
 872         t->delete = dn_fib_table_delete;
 873         t->lookup = dn_fib_table_lookup;
 874         t->flush  = dn_fib_table_flush;
 875         t->dump = dn_fib_table_dump;
 876         hlist_add_head_rcu(&t->hlist, &dn_fib_table_hash[h]);
 877
 878         return t;
 879 }
 880
 881 struct dn_fib_table *dn_fib_empty_table(void)
 882 {
 883         u32 id;
 884
 885         for(id = RT_TABLE_MIN; id <= RT_TABLE_MAX; id++)
 886                 if (dn_fib_get_table(id, 0) == NULL)
 887                         return dn_fib_get_table(id, 1);
 888         return NULL;
 889 }
 890
 891 void dn_fib_flush(void)
 892 {
 893         int flushed = 0;
 894         struct dn_fib_table *tb;
 895         unsigned int h;
 896
 897         for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
 898                 hlist_for_each_entry(tb, &dn_fib_table_hash[h], hlist)
 899                         flushed += tb->flush(tb);
 900         }
 901
 902         if (flushed)
 903                 dn_rt_cache_flush(-1);
 904 }
 905
 906 void __init dn_fib_table_init(void)
 907 {
 908         dn_hash_kmem = kmem_cache_create("dn_fib_info_cache",
 909                                         sizeof(struct dn_fib_info),
 910                                         0, SLAB_HWCACHE_ALIGN,
 911                                         NULL);
 912 }
 913
 914 void __exit dn_fib_table_cleanup(void)
 915 {
 916         struct dn_fib_table *t;
 917         struct hlist_node *next;
 918         unsigned int h;
 919
 920         write_lock(&dn_fib_tables_lock);
 921         for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
 922                 hlist_for_each_entry_safe(t, next, &dn_fib_table_hash[h],
 923                                           hlist) {
 924                         hlist_del(&t->hlist);
 925                         kfree(t);
 926                 }
 927         }
 928         write_unlock(&dn_fib_tables_lock);
 929 }