net/decnet/dn_table.c

   1 /*
   2  * DECnet       An implementation of the DECnet protocol suite for the LINUX
   3  *              operating system.  DECnet is implemented using the  BSD Socket
   4  *              interface as the means of communication with the user level.
   5  *
   6  *              DECnet Routing Forwarding Information Base (Routing Tables)
   7  *
   8  * Author:      Steve Whitehouse <SteveW@ACM.org>
   9  *              Mostly copied from the IPv4 routing code
  10  *
  11  *
  12  * Changes:
  13  *
  14  */
  15 #include <linux/string.h>
  16 #include <linux/net.h>
  17 #include <linux/socket.h>
  18 #include <linux/sockios.h>
  19 #include <linux/init.h>
  20 #include <linux/skbuff.h>
  21 #include <linux/netlink.h>
  22 #include <linux/rtnetlink.h>
  23 #include <linux/proc_fs.h>
  24 #include <linux/netdevice.h>
  25 #include <linux/timer.h>
  26 #include <linux/spinlock.h>
  27 #include <asm/atomic.h>
  28 #include <asm/uaccess.h>
  29 #include <linux/route.h> /* RTF_xxx */
  30 #include <net/neighbour.h>
  31 #include <net/dst.h>
  32 #include <net/flow.h>
  33 #include <net/fib_rules.h>
  34 #include <net/dn.h>
  35 #include <net/dn_route.h>
  36 #include <net/dn_fib.h>
  37 #include <net/dn_neigh.h>
  38 #include <net/dn_dev.h>
  39
  40 struct dn_zone
  41 {
  42         struct dn_zone          *dz_next;
  43         struct dn_fib_node      **dz_hash;
  44         int                     dz_nent;
  45         int                     dz_divisor;
  46         u32                     dz_hashmask;
  47 #define DZ_HASHMASK(dz) ((dz)->dz_hashmask)
  48         int                     dz_order;
  49         __le16                  dz_mask;
  50 #define DZ_MASK(dz)     ((dz)->dz_mask)
  51 };
  52
  53 struct dn_hash
  54 {
  55         struct dn_zone  *dh_zones[17];
  56         struct dn_zone  *dh_zone_list;
  57 };
  58
  59 #define dz_key_0(key)           ((key).datum = 0)
  60 #define dz_prefix(key,dz)       ((key).datum)
  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 = dn_ntohs(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         int i;
 126         struct dn_fib_node *f, **fp, *next;
 127
 128         for(i = 0; i < old_divisor; i++) {
 129                 for(f = old_ht[i]; f; f = f->fn_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", old_divisor);
 156                 case 256:
 157                         new_divisor = 1024;
 158                         new_hashmask = 0x3FF;
 159                         break;
 160         }
 161
 162         ht = kcalloc(new_divisor, sizeof(struct dn_fib_node*), GFP_KERNEL);
 163         if (ht == NULL)
 164                 return;
 165
 166         write_lock_bh(&dn_fib_tables_lock);
 167         old_ht = dz->dz_hash;
 168         dz->dz_hash = ht;
 169         dz->dz_hashmask = new_hashmask;
 170         dz->dz_divisor = new_divisor;
 171         dn_rebuild_zone(dz, old_ht, old_divisor);
 172         write_unlock_bh(&dn_fib_tables_lock);
 173         kfree(old_ht);
 174 }
 175
 176 static void dn_free_node(struct dn_fib_node *f)
 177 {
 178         dn_fib_release_info(DN_FIB_INFO(f));
 179         kmem_cache_free(dn_hash_kmem, f);
 180 }
 181
 182
 183 static struct dn_zone *dn_new_zone(struct dn_hash *table, int z)
 184 {
 185         int i;
 186         struct dn_zone *dz = kzalloc(sizeof(struct dn_zone), GFP_KERNEL);
 187         if (!dz)
 188                 return NULL;
 189
 190         if (z) {
 191                 dz->dz_divisor = 16;
 192                 dz->dz_hashmask = 0x0F;
 193         } else {
 194                 dz->dz_divisor = 1;
 195                 dz->dz_hashmask = 0;
 196         }
 197
 198         dz->dz_hash = kcalloc(dz->dz_divisor, sizeof(struct dn_fib_node *), GFP_KERNEL);
 199         if (!dz->dz_hash) {
 200                 kfree(dz);
 201                 return NULL;
 202         }
 203
 204         dz->dz_order = z;
 205         dz->dz_mask = dnet_make_mask(z);
 206
 207         for(i = z + 1; i <= 16; i++)
 208                 if (table->dh_zones[i])
 209                         break;
 210
 211         write_lock_bh(&dn_fib_tables_lock);
 212         if (i>16) {
 213                 dz->dz_next = table->dh_zone_list;
 214                 table->dh_zone_list = dz;
 215         } else {
 216                 dz->dz_next = table->dh_zones[i]->dz_next;
 217                 table->dh_zones[i]->dz_next = dz;
 218         }
 219         table->dh_zones[z] = dz;
 220         write_unlock_bh(&dn_fib_tables_lock);
 221         return dz;
 222 }
 223
 224
 225 static int dn_fib_nh_match(struct rtmsg *r, struct nlmsghdr *nlh, struct dn_kern_rta *rta, struct dn_fib_info *fi)
 226 {
 227         struct rtnexthop *nhp;
 228         int nhlen;
 229
 230         if (rta->rta_priority && *rta->rta_priority != fi->fib_priority)
 231                 return 1;
 232
 233         if (rta->rta_oif || rta->rta_gw) {
 234                 if ((!rta->rta_oif || *rta->rta_oif == fi->fib_nh->nh_oif) &&
 235                     (!rta->rta_gw  || memcmp(rta->rta_gw, &fi->fib_nh->nh_gw, 2) == 0))
 236                         return 0;
 237                 return 1;
 238         }
 239
 240         if (rta->rta_mp == NULL)
 241                 return 0;
 242
 243         nhp = RTA_DATA(rta->rta_mp);
 244         nhlen = RTA_PAYLOAD(rta->rta_mp);
 245
 246         for_nexthops(fi) {
 247                 int attrlen = nhlen - sizeof(struct rtnexthop);
 248                 __le16 gw;
 249
 250                 if (attrlen < 0 || (nhlen -= nhp->rtnh_len) < 0)
 251                         return -EINVAL;
 252                 if (nhp->rtnh_ifindex && nhp->rtnh_ifindex != nh->nh_oif)
 253                         return 1;
 254                 if (attrlen) {
 255                         gw = dn_fib_get_attr16(RTNH_DATA(nhp), attrlen, RTA_GATEWAY);
 256
 257                         if (gw && gw != nh->nh_gw)
 258                                 return 1;
 259                 }
 260                 nhp = RTNH_NEXT(nhp);
 261         } endfor_nexthops(fi);
 262
 263         return 0;
 264 }
 265
 266 static inline size_t dn_fib_nlmsg_size(struct dn_fib_info *fi)
 267 {
 268         size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg))
 269                          + nla_total_size(4) /* RTA_TABLE */
 270                          + nla_total_size(2) /* RTA_DST */
 271                          + nla_total_size(4); /* RTA_PRIORITY */
 272
 273         /* space for nested metrics */
 274         payload += nla_total_size((RTAX_MAX * nla_total_size(4)));
 275
 276         if (fi->fib_nhs) {
 277                 /* Also handles the special case fib_nhs == 1 */
 278
 279                 /* each nexthop is packed in an attribute */
 280                 size_t nhsize = nla_total_size(sizeof(struct rtnexthop));
 281
 282                 /* may contain a gateway attribute */
 283                 nhsize += nla_total_size(4);
 284
 285                 /* all nexthops are packed in a nested attribute */
 286                 payload += nla_total_size(fi->fib_nhs * nhsize);
 287         }
 288
 289         return payload;
 290 }
 291
 292 static int dn_fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
 293                         u32 tb_id, u8 type, u8 scope, void *dst, int dst_len,
 294                         struct dn_fib_info *fi, unsigned int flags)
 295 {
 296         struct rtmsg *rtm;
 297         struct nlmsghdr *nlh;
 298         unsigned char *b = skb->tail;
 299
 300         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*rtm), flags);
 301         rtm = NLMSG_DATA(nlh);
 302         rtm->rtm_family = AF_DECnet;
 303         rtm->rtm_dst_len = dst_len;
 304         rtm->rtm_src_len = 0;
 305         rtm->rtm_tos = 0;
 306         rtm->rtm_table = tb_id;
 307         RTA_PUT_U32(skb, RTA_TABLE, tb_id);
 308         rtm->rtm_flags = fi->fib_flags;
 309         rtm->rtm_scope = scope;
 310         rtm->rtm_type  = type;
 311         if (rtm->rtm_dst_len)
 312                 RTA_PUT(skb, RTA_DST, 2, dst);
 313         rtm->rtm_protocol = fi->fib_protocol;
 314         if (fi->fib_priority)
 315                 RTA_PUT(skb, RTA_PRIORITY, 4, &fi->fib_priority);
 316         if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0)
 317                 goto rtattr_failure;
 318         if (fi->fib_nhs == 1) {
 319                 if (fi->fib_nh->nh_gw)
 320                         RTA_PUT(skb, RTA_GATEWAY, 2, &fi->fib_nh->nh_gw);
 321                 if (fi->fib_nh->nh_oif)
 322                         RTA_PUT(skb, RTA_OIF, sizeof(int), &fi->fib_nh->nh_oif);
 323         }
 324         if (fi->fib_nhs > 1) {
 325                 struct rtnexthop *nhp;
 326                 struct rtattr *mp_head;
 327                 if (skb_tailroom(skb) <= RTA_SPACE(0))
 328                         goto rtattr_failure;
 329                 mp_head = (struct rtattr *)skb_put(skb, RTA_SPACE(0));
 330
 331                 for_nexthops(fi) {
 332                         if (skb_tailroom(skb) < RTA_ALIGN(RTA_ALIGN(sizeof(*nhp)) + 4))
 333                                 goto rtattr_failure;
 334                         nhp = (struct rtnexthop *)skb_put(skb, RTA_ALIGN(sizeof(*nhp)));
 335                         nhp->rtnh_flags = nh->nh_flags & 0xFF;
 336                         nhp->rtnh_hops = nh->nh_weight - 1;
 337                         nhp->rtnh_ifindex = nh->nh_oif;
 338                         if (nh->nh_gw)
 339                                 RTA_PUT(skb, RTA_GATEWAY, 2, &nh->nh_gw);
 340                         nhp->rtnh_len = skb->tail - (unsigned char *)nhp;
 341                 } endfor_nexthops(fi);
 342                 mp_head->rta_type = RTA_MULTIPATH;
 343                 mp_head->rta_len = skb->tail - (u8*)mp_head;
 344         }
 345
 346         nlh->nlmsg_len = skb->tail - b;
 347         return skb->len;
 348
 349
 350 nlmsg_failure:
 351 rtattr_failure:
 352         skb_trim(skb, b - skb->data);
 353         return -1;
 354 }
 355
 356
 357 static void dn_rtmsg_fib(int event, struct dn_fib_node *f, int z, u32 tb_id,
 358                         struct nlmsghdr *nlh, struct netlink_skb_parms *req)
 359 {
 360         struct sk_buff *skb;
 361         u32 pid = req ? req->pid : 0;
 362         int err = -ENOBUFS;
 363
 364         skb = nlmsg_new(dn_fib_nlmsg_size(DN_FIB_INFO(f)), GFP_KERNEL);
 365         if (skb == NULL)
 366                 goto errout;
 367
 368         err = dn_fib_dump_info(skb, pid, nlh->nlmsg_seq, event, tb_id,
 369                                f->fn_type, f->fn_scope, &f->fn_key, z,
 370                                DN_FIB_INFO(f), 0);
 371         /* failure implies BUG in dn_fib_nlmsg_size() */
 372         BUG_ON(err < 0);
 373
 374         err = rtnl_notify(skb, pid, RTNLGRP_DECnet_ROUTE, nlh, GFP_KERNEL);
 375 errout:
 376         if (err < 0)
 377                 rtnl_set_sk_err(RTNLGRP_DECnet_ROUTE, err);
 378 }
 379
 380 static __inline__ int dn_hash_dump_bucket(struct sk_buff *skb,
 381                                 struct netlink_callback *cb,
 382                                 struct dn_fib_table *tb,
 383                                 struct dn_zone *dz,
 384                                 struct dn_fib_node *f)
 385 {
 386         int i, s_i;
 387
 388         s_i = cb->args[4];
 389         for(i = 0; f; i++, f = f->fn_next) {
 390                 if (i < s_i)
 391                         continue;
 392                 if (f->fn_state & DN_S_ZOMBIE)
 393                         continue;
 394                 if (dn_fib_dump_info(skb, NETLINK_CB(cb->skb).pid,
 395                                 cb->nlh->nlmsg_seq,
 396                                 RTM_NEWROUTE,
 397                                 tb->n,
 398                                 (f->fn_state & DN_S_ZOMBIE) ? 0 : f->fn_type,
 399                                 f->fn_scope, &f->fn_key, dz->dz_order,
 400                                 f->fn_info, NLM_F_MULTI) < 0) {
 401                         cb->args[4] = i;
 402                         return -1;
 403                 }
 404         }
 405         cb->args[4] = i;
 406         return skb->len;
 407 }
 408
 409 static __inline__ int dn_hash_dump_zone(struct sk_buff *skb,
 410                                 struct netlink_callback *cb,
 411                                 struct dn_fib_table *tb,
 412                                 struct dn_zone *dz)
 413 {
 414         int h, s_h;
 415
 416         s_h = cb->args[3];
 417         for(h = 0; h < dz->dz_divisor; h++) {
 418                 if (h < s_h)
 419                         continue;
 420                 if (h > s_h)
 421                         memset(&cb->args[4], 0, sizeof(cb->args) - 4*sizeof(cb->args[0]));
 422                 if (dz->dz_hash == NULL || dz->dz_hash[h] == NULL)
 423                         continue;
 424                 if (dn_hash_dump_bucket(skb, cb, tb, dz, dz->dz_hash[h]) < 0) {
 425                         cb->args[3] = h;
 426                         return -1;
 427                 }
 428         }
 429         cb->args[3] = h;
 430         return skb->len;
 431 }
 432
 433 static int dn_fib_table_dump(struct dn_fib_table *tb, struct sk_buff *skb,
 434                                 struct netlink_callback *cb)
 435 {
 436         int m, s_m;
 437         struct dn_zone *dz;
 438         struct dn_hash *table = (struct dn_hash *)tb->data;
 439
 440         s_m = cb->args[2];
 441         read_lock(&dn_fib_tables_lock);
 442         for(dz = table->dh_zone_list, m = 0; dz; dz = dz->dz_next, m++) {
 443                 if (m < s_m)
 444                         continue;
 445                 if (m > s_m)
 446                         memset(&cb->args[3], 0, sizeof(cb->args) - 3*sizeof(cb->args[0]));
 447
 448                 if (dn_hash_dump_zone(skb, cb, tb, dz) < 0) {
 449                         cb->args[2] = m;
 450                         read_unlock(&dn_fib_tables_lock);
 451                         return -1;
 452                 }
 453         }
 454         read_unlock(&dn_fib_tables_lock);
 455         cb->args[2] = m;
 456
 457         return skb->len;
 458 }
 459
 460 int dn_fib_dump(struct sk_buff *skb, struct netlink_callback *cb)
 461 {
 462         unsigned int h, s_h;
 463         unsigned int e = 0, s_e;
 464         struct dn_fib_table *tb;
 465         struct hlist_node *node;
 466         int dumped = 0;
 467
 468         if (NLMSG_PAYLOAD(cb->nlh, 0) >= sizeof(struct rtmsg) &&
 469                 ((struct rtmsg *)NLMSG_DATA(cb->nlh))->rtm_flags&RTM_F_CLONED)
 470                         return dn_cache_dump(skb, cb);
 471
 472         s_h = cb->args[0];
 473         s_e = cb->args[1];
 474
 475         for (h = s_h; h < DN_FIB_TABLE_HASHSZ; h++, s_h = 0) {
 476                 e = 0;
 477                 hlist_for_each_entry(tb, node, &dn_fib_table_hash[h], hlist) {
 478                         if (e < s_e)
 479                                 goto next;
 480                         if (dumped)
 481                                 memset(&cb->args[2], 0, sizeof(cb->args) -
 482                                                  2 * sizeof(cb->args[0]));
 483                         if (tb->dump(tb, skb, cb) < 0)
 484                                 goto out;
 485                         dumped = 1;
 486 next:
 487                         e++;
 488                 }
 489         }
 490 out:
 491         cb->args[1] = e;
 492         cb->args[0] = h;
 493
 494         return skb->len;
 495 }
 496
 497 static int dn_fib_table_insert(struct dn_fib_table *tb, struct rtmsg *r, struct dn_kern_rta *rta, struct nlmsghdr *n, struct netlink_skb_parms *req)
 498 {
 499         struct dn_hash *table = (struct dn_hash *)tb->data;
 500         struct dn_fib_node *new_f, *f, **fp, **del_fp;
 501         struct dn_zone *dz;
 502         struct dn_fib_info *fi;
 503         int z = r->rtm_dst_len;
 504         int type = r->rtm_type;
 505         dn_fib_key_t key;
 506         int err;
 507
 508         if (z > 16)
 509                 return -EINVAL;
 510
 511         dz = table->dh_zones[z];
 512         if (!dz && !(dz = dn_new_zone(table, z)))
 513                 return -ENOBUFS;
 514
 515         dz_key_0(key);
 516         if (rta->rta_dst) {
 517                 __le16 dst;
 518                 memcpy(&dst, rta->rta_dst, 2);
 519                 if (dst & ~DZ_MASK(dz))
 520                         return -EINVAL;
 521                 key = dz_key(dst, dz);
 522         }
 523
 524         if ((fi = dn_fib_create_info(r, rta, n, &err)) == NULL)
 525                 return err;
 526
 527         if (dz->dz_nent > (dz->dz_divisor << 2) &&
 528                         dz->dz_divisor > DN_MAX_DIVISOR &&
 529                         (z==16 || (1<<z) > dz->dz_divisor))
 530                 dn_rehash_zone(dz);
 531
 532         fp = dn_chain_p(key, dz);
 533
 534         DN_FIB_SCAN(f, fp) {
 535                 if (dn_key_leq(key, f->fn_key))
 536                         break;
 537         }
 538
 539         del_fp = NULL;
 540
 541         if (f && (f->fn_state & DN_S_ZOMBIE) &&
 542                         dn_key_eq(f->fn_key, key)) {
 543                 del_fp = fp;
 544                 fp = &f->fn_next;
 545                 f = *fp;
 546                 goto create;
 547         }
 548
 549         DN_FIB_SCAN_KEY(f, fp, key) {
 550                 if (fi->fib_priority <= DN_FIB_INFO(f)->fib_priority)
 551                         break;
 552         }
 553
 554         if (f && dn_key_eq(f->fn_key, key) &&
 555                         fi->fib_priority == DN_FIB_INFO(f)->fib_priority) {
 556                 struct dn_fib_node **ins_fp;
 557
 558                 err = -EEXIST;
 559                 if (n->nlmsg_flags & NLM_F_EXCL)
 560                         goto out;
 561
 562                 if (n->nlmsg_flags & NLM_F_REPLACE) {
 563                         del_fp = fp;
 564                         fp = &f->fn_next;
 565                         f = *fp;
 566                         goto replace;
 567                 }
 568
 569                 ins_fp = fp;
 570                 err = -EEXIST;
 571
 572                 DN_FIB_SCAN_KEY(f, fp, key) {
 573                         if (fi->fib_priority != DN_FIB_INFO(f)->fib_priority)
 574                                 break;
 575                         if (f->fn_type == type && f->fn_scope == r->rtm_scope
 576                                         && DN_FIB_INFO(f) == fi)
 577                                 goto out;
 578                 }
 579
 580                 if (!(n->nlmsg_flags & NLM_F_APPEND)) {
 581                         fp = ins_fp;
 582                         f = *fp;
 583                 }
 584         }
 585
 586 create:
 587         err = -ENOENT;
 588         if (!(n->nlmsg_flags & NLM_F_CREATE))
 589                 goto out;
 590
 591 replace:
 592         err = -ENOBUFS;
 593         new_f = kmem_cache_alloc(dn_hash_kmem, GFP_KERNEL);
 594         if (new_f == NULL)
 595                 goto out;
 596
 597         memset(new_f, 0, sizeof(struct dn_fib_node));
 598
 599         new_f->fn_key = key;
 600         new_f->fn_type = type;
 601         new_f->fn_scope = r->rtm_scope;
 602         DN_FIB_INFO(new_f) = fi;
 603
 604         new_f->fn_next = f;
 605         write_lock_bh(&dn_fib_tables_lock);
 606         *fp = new_f;
 607         write_unlock_bh(&dn_fib_tables_lock);
 608         dz->dz_nent++;
 609
 610         if (del_fp) {
 611                 f = *del_fp;
 612                 write_lock_bh(&dn_fib_tables_lock);
 613                 *del_fp = f->fn_next;
 614                 write_unlock_bh(&dn_fib_tables_lock);
 615
 616                 if (!(f->fn_state & DN_S_ZOMBIE))
 617                         dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 618                 if (f->fn_state & DN_S_ACCESSED)
 619                         dn_rt_cache_flush(-1);
 620                 dn_free_node(f);
 621                 dz->dz_nent--;
 622         } else {
 623                 dn_rt_cache_flush(-1);
 624         }
 625
 626         dn_rtmsg_fib(RTM_NEWROUTE, new_f, z, tb->n, n, req);
 627
 628         return 0;
 629 out:
 630         dn_fib_release_info(fi);
 631         return err;
 632 }
 633
 634
 635 static int dn_fib_table_delete(struct dn_fib_table *tb, struct rtmsg *r, struct dn_kern_rta *rta, struct nlmsghdr *n, struct netlink_skb_parms *req)
 636 {
 637         struct dn_hash *table = (struct dn_hash*)tb->data;
 638         struct dn_fib_node **fp, **del_fp, *f;
 639         int z = r->rtm_dst_len;
 640         struct dn_zone *dz;
 641         dn_fib_key_t key;
 642         int matched;
 643
 644
 645         if (z > 16)
 646                 return -EINVAL;
 647
 648         if ((dz = table->dh_zones[z]) == NULL)
 649                 return -ESRCH;
 650
 651         dz_key_0(key);
 652         if (rta->rta_dst) {
 653                 __le16 dst;
 654                 memcpy(&dst, rta->rta_dst, 2);
 655                 if (dst & ~DZ_MASK(dz))
 656                         return -EINVAL;
 657                 key = dz_key(dst, dz);
 658         }
 659
 660         fp = dn_chain_p(key, dz);
 661
 662         DN_FIB_SCAN(f, fp) {
 663                 if (dn_key_eq(f->fn_key, key))
 664                         break;
 665                 if (dn_key_leq(key, f->fn_key))
 666                         return -ESRCH;
 667         }
 668
 669         matched = 0;
 670         del_fp = NULL;
 671         DN_FIB_SCAN_KEY(f, fp, key) {
 672                 struct dn_fib_info *fi = DN_FIB_INFO(f);
 673
 674                 if (f->fn_state & DN_S_ZOMBIE)
 675                         return -ESRCH;
 676
 677                 matched++;
 678
 679                 if (del_fp == NULL &&
 680                                 (!r->rtm_type || f->fn_type == r->rtm_type) &&
 681                                 (r->rtm_scope == RT_SCOPE_NOWHERE || f->fn_scope == r->rtm_scope) &&
 682                                 (!r->rtm_protocol ||
 683                                         fi->fib_protocol == r->rtm_protocol) &&
 684                                 dn_fib_nh_match(r, n, rta, fi) == 0)
 685                         del_fp = fp;
 686         }
 687
 688         if (del_fp) {
 689                 f = *del_fp;
 690                 dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 691
 692                 if (matched != 1) {
 693                         write_lock_bh(&dn_fib_tables_lock);
 694                         *del_fp = f->fn_next;
 695                         write_unlock_bh(&dn_fib_tables_lock);
 696
 697                         if (f->fn_state & DN_S_ACCESSED)
 698                                 dn_rt_cache_flush(-1);
 699                         dn_free_node(f);
 700                         dz->dz_nent--;
 701                 } else {
 702                         f->fn_state |= DN_S_ZOMBIE;
 703                         if (f->fn_state & DN_S_ACCESSED) {
 704                                 f->fn_state &= ~DN_S_ACCESSED;
 705                                 dn_rt_cache_flush(-1);
 706                         }
 707                         if (++dn_fib_hash_zombies > 128)
 708                                 dn_fib_flush();
 709                 }
 710
 711                 return 0;
 712         }
 713
 714         return -ESRCH;
 715 }
 716
 717 static inline int dn_flush_list(struct dn_fib_node **fp, int z, struct dn_hash *table)
 718 {
 719         int found = 0;
 720         struct dn_fib_node *f;
 721
 722         while((f = *fp) != NULL) {
 723                 struct dn_fib_info *fi = DN_FIB_INFO(f);
 724
 725                 if (fi && ((f->fn_state & DN_S_ZOMBIE) || (fi->fib_flags & RTNH_F_DEAD))) {
 726                         write_lock_bh(&dn_fib_tables_lock);
 727                         *fp = f->fn_next;
 728                         write_unlock_bh(&dn_fib_tables_lock);
 729
 730                         dn_free_node(f);
 731                         found++;
 732                         continue;
 733                 }
 734                 fp = &f->fn_next;
 735         }
 736
 737         return found;
 738 }
 739
 740 static int dn_fib_table_flush(struct dn_fib_table *tb)
 741 {
 742         struct dn_hash *table = (struct dn_hash *)tb->data;
 743         struct dn_zone *dz;
 744         int found = 0;
 745
 746         dn_fib_hash_zombies = 0;
 747         for(dz = table->dh_zone_list; dz; dz = dz->dz_next) {
 748                 int i;
 749                 int tmp = 0;
 750                 for(i = dz->dz_divisor-1; i >= 0; i--)
 751                         tmp += dn_flush_list(&dz->dz_hash[i], dz->dz_order, table);
 752                 dz->dz_nent -= tmp;
 753                 found += tmp;
 754         }
 755
 756         return found;
 757 }
 758
 759 static int dn_fib_table_lookup(struct dn_fib_table *tb, const struct flowi *flp, struct dn_fib_res *res)
 760 {
 761         int err;
 762         struct dn_zone *dz;
 763         struct dn_hash *t = (struct dn_hash *)tb->data;
 764
 765         read_lock(&dn_fib_tables_lock);
 766         for(dz = t->dh_zone_list; dz; dz = dz->dz_next) {
 767                 struct dn_fib_node *f;
 768                 dn_fib_key_t k = dz_key(flp->fld_dst, dz);
 769
 770                 for(f = dz_chain(k, dz); f; f = f->fn_next) {
 771                         if (!dn_key_eq(k, f->fn_key)) {
 772                                 if (dn_key_leq(k, f->fn_key))
 773                                         break;
 774                                 else
 775                                         continue;
 776                         }
 777
 778                         f->fn_state |= DN_S_ACCESSED;
 779
 780                         if (f->fn_state&DN_S_ZOMBIE)
 781                                 continue;
 782
 783                         if (f->fn_scope < flp->fld_scope)
 784                                 continue;
 785
 786                         err = dn_fib_semantic_match(f->fn_type, DN_FIB_INFO(f), flp, res);
 787
 788                         if (err == 0) {
 789                                 res->type = f->fn_type;
 790                                 res->scope = f->fn_scope;
 791                                 res->prefixlen = dz->dz_order;
 792                                 goto out;
 793                         }
 794                         if (err < 0)
 795                                 goto out;
 796                 }
 797         }
 798         err = 1;
 799 out:
 800         read_unlock(&dn_fib_tables_lock);
 801         return err;
 802 }
 803
 804
 805 struct dn_fib_table *dn_fib_get_table(u32 n, int create)
 806 {
 807         struct dn_fib_table *t;
 808         struct hlist_node *node;
 809         unsigned int h;
 810
 811         if (n < RT_TABLE_MIN)
 812                 return NULL;
 813
 814         if (n > RT_TABLE_MAX)
 815                 return NULL;
 816
 817         h = n & (DN_FIB_TABLE_HASHSZ - 1);
 818         rcu_read_lock();
 819         hlist_for_each_entry_rcu(t, node, &dn_fib_table_hash[h], hlist) {
 820                 if (t->n == n) {
 821                         rcu_read_unlock();
 822                         return t;
 823                 }
 824         }
 825         rcu_read_unlock();
 826
 827         if (!create)
 828                 return NULL;
 829
 830         if (in_interrupt() && net_ratelimit()) {
 831                 printk(KERN_DEBUG "DECnet: BUG! Attempt to create routing table from interrupt\n");
 832                 return NULL;
 833         }
 834
 835         t = kzalloc(sizeof(struct dn_fib_table) + sizeof(struct dn_hash),
 836                     GFP_KERNEL);
 837         if (t == NULL)
 838                 return NULL;
 839
 840         t->n = n;
 841         t->insert = dn_fib_table_insert;
 842         t->delete = dn_fib_table_delete;
 843         t->lookup = dn_fib_table_lookup;
 844         t->flush  = dn_fib_table_flush;
 845         t->dump = dn_fib_table_dump;
 846         hlist_add_head_rcu(&t->hlist, &dn_fib_table_hash[h]);
 847
 848         return t;
 849 }
 850
 851 struct dn_fib_table *dn_fib_empty_table(void)
 852 {
 853         u32 id;
 854
 855         for(id = RT_TABLE_MIN; id <= RT_TABLE_MAX; id++)
 856                 if (dn_fib_get_table(id, 0) == NULL)
 857                         return dn_fib_get_table(id, 1);
 858         return NULL;
 859 }
 860
 861 void dn_fib_flush(void)
 862 {
 863         int flushed = 0;
 864         struct dn_fib_table *tb;
 865         struct hlist_node *node;
 866         unsigned int h;
 867
 868         for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
 869                 hlist_for_each_entry(tb, node, &dn_fib_table_hash[h], hlist)
 870                         flushed += tb->flush(tb);
 871         }
 872
 873         if (flushed)
 874                 dn_rt_cache_flush(-1);
 875 }
 876
 877 void __init dn_fib_table_init(void)
 878 {
 879         dn_hash_kmem = kmem_cache_create("dn_fib_info_cache",
 880                                         sizeof(struct dn_fib_info),
 881                                         0, SLAB_HWCACHE_ALIGN,
 882                                         NULL, NULL);
 883 }
 884
 885 void __exit dn_fib_table_cleanup(void)
 886 {
 887         struct dn_fib_table *t;
 888         struct hlist_node *node, *next;
 889         unsigned int h;
 890
 891         write_lock(&dn_fib_tables_lock);
 892         for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
 893                 hlist_for_each_entry_safe(t, node, next, &dn_fib_table_hash[h],
 894                                           hlist) {
 895                         hlist_del(&t->hlist);
 896                         kfree(t);
 897                 }
 898         }
 899         write_unlock(&dn_fib_tables_lock);
 900 }