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 -EMSGSIZE;
 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         if (err < 0) {
 372                 /* -EMSGSIZE implies BUG in dn_fib_nlmsg_size() */
 373                 WARN_ON(err == -EMSGSIZE);
 374                 kfree_skb(skb);
 375                 goto errout;
 376         }
 377         err = rtnl_notify(skb, pid, RTNLGRP_DECnet_ROUTE, nlh, GFP_KERNEL);
 378 errout:
 379         if (err < 0)
 380                 rtnl_set_sk_err(RTNLGRP_DECnet_ROUTE, err);
 381 }
 382
 383 static __inline__ int dn_hash_dump_bucket(struct sk_buff *skb,
 384                                 struct netlink_callback *cb,
 385                                 struct dn_fib_table *tb,
 386                                 struct dn_zone *dz,
 387                                 struct dn_fib_node *f)
 388 {
 389         int i, s_i;
 390
 391         s_i = cb->args[4];
 392         for(i = 0; f; i++, f = f->fn_next) {
 393                 if (i < s_i)
 394                         continue;
 395                 if (f->fn_state & DN_S_ZOMBIE)
 396                         continue;
 397                 if (dn_fib_dump_info(skb, NETLINK_CB(cb->skb).pid,
 398                                 cb->nlh->nlmsg_seq,
 399                                 RTM_NEWROUTE,
 400                                 tb->n,
 401                                 (f->fn_state & DN_S_ZOMBIE) ? 0 : f->fn_type,
 402                                 f->fn_scope, &f->fn_key, dz->dz_order,
 403                                 f->fn_info, NLM_F_MULTI) < 0) {
 404                         cb->args[4] = i;
 405                         return -1;
 406                 }
 407         }
 408         cb->args[4] = i;
 409         return skb->len;
 410 }
 411
 412 static __inline__ int dn_hash_dump_zone(struct sk_buff *skb,
 413                                 struct netlink_callback *cb,
 414                                 struct dn_fib_table *tb,
 415                                 struct dn_zone *dz)
 416 {
 417         int h, s_h;
 418
 419         s_h = cb->args[3];
 420         for(h = 0; h < dz->dz_divisor; h++) {
 421                 if (h < s_h)
 422                         continue;
 423                 if (h > s_h)
 424                         memset(&cb->args[4], 0, sizeof(cb->args) - 4*sizeof(cb->args[0]));
 425                 if (dz->dz_hash == NULL || dz->dz_hash[h] == NULL)
 426                         continue;
 427                 if (dn_hash_dump_bucket(skb, cb, tb, dz, dz->dz_hash[h]) < 0) {
 428                         cb->args[3] = h;
 429                         return -1;
 430                 }
 431         }
 432         cb->args[3] = h;
 433         return skb->len;
 434 }
 435
 436 static int dn_fib_table_dump(struct dn_fib_table *tb, struct sk_buff *skb,
 437                                 struct netlink_callback *cb)
 438 {
 439         int m, s_m;
 440         struct dn_zone *dz;
 441         struct dn_hash *table = (struct dn_hash *)tb->data;
 442
 443         s_m = cb->args[2];
 444         read_lock(&dn_fib_tables_lock);
 445         for(dz = table->dh_zone_list, m = 0; dz; dz = dz->dz_next, m++) {
 446                 if (m < s_m)
 447                         continue;
 448                 if (m > s_m)
 449                         memset(&cb->args[3], 0, sizeof(cb->args) - 3*sizeof(cb->args[0]));
 450
 451                 if (dn_hash_dump_zone(skb, cb, tb, dz) < 0) {
 452                         cb->args[2] = m;
 453                         read_unlock(&dn_fib_tables_lock);
 454                         return -1;
 455                 }
 456         }
 457         read_unlock(&dn_fib_tables_lock);
 458         cb->args[2] = m;
 459
 460         return skb->len;
 461 }
 462
 463 int dn_fib_dump(struct sk_buff *skb, struct netlink_callback *cb)
 464 {
 465         unsigned int h, s_h;
 466         unsigned int e = 0, s_e;
 467         struct dn_fib_table *tb;
 468         struct hlist_node *node;
 469         int dumped = 0;
 470
 471         if (NLMSG_PAYLOAD(cb->nlh, 0) >= sizeof(struct rtmsg) &&
 472                 ((struct rtmsg *)NLMSG_DATA(cb->nlh))->rtm_flags&RTM_F_CLONED)
 473                         return dn_cache_dump(skb, cb);
 474
 475         s_h = cb->args[0];
 476         s_e = cb->args[1];
 477
 478         for (h = s_h; h < DN_FIB_TABLE_HASHSZ; h++, s_h = 0) {
 479                 e = 0;
 480                 hlist_for_each_entry(tb, node, &dn_fib_table_hash[h], hlist) {
 481                         if (e < s_e)
 482                                 goto next;
 483                         if (dumped)
 484                                 memset(&cb->args[2], 0, sizeof(cb->args) -
 485                                                  2 * sizeof(cb->args[0]));
 486                         if (tb->dump(tb, skb, cb) < 0)
 487                                 goto out;
 488                         dumped = 1;
 489 next:
 490                         e++;
 491                 }
 492         }
 493 out:
 494         cb->args[1] = e;
 495         cb->args[0] = h;
 496
 497         return skb->len;
 498 }
 499
 500 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)
 501 {
 502         struct dn_hash *table = (struct dn_hash *)tb->data;
 503         struct dn_fib_node *new_f, *f, **fp, **del_fp;
 504         struct dn_zone *dz;
 505         struct dn_fib_info *fi;
 506         int z = r->rtm_dst_len;
 507         int type = r->rtm_type;
 508         dn_fib_key_t key;
 509         int err;
 510
 511         if (z > 16)
 512                 return -EINVAL;
 513
 514         dz = table->dh_zones[z];
 515         if (!dz && !(dz = dn_new_zone(table, z)))
 516                 return -ENOBUFS;
 517
 518         dz_key_0(key);
 519         if (rta->rta_dst) {
 520                 __le16 dst;
 521                 memcpy(&dst, rta->rta_dst, 2);
 522                 if (dst & ~DZ_MASK(dz))
 523                         return -EINVAL;
 524                 key = dz_key(dst, dz);
 525         }
 526
 527         if ((fi = dn_fib_create_info(r, rta, n, &err)) == NULL)
 528                 return err;
 529
 530         if (dz->dz_nent > (dz->dz_divisor << 2) &&
 531                         dz->dz_divisor > DN_MAX_DIVISOR &&
 532                         (z==16 || (1<<z) > dz->dz_divisor))
 533                 dn_rehash_zone(dz);
 534
 535         fp = dn_chain_p(key, dz);
 536
 537         DN_FIB_SCAN(f, fp) {
 538                 if (dn_key_leq(key, f->fn_key))
 539                         break;
 540         }
 541
 542         del_fp = NULL;
 543
 544         if (f && (f->fn_state & DN_S_ZOMBIE) &&
 545                         dn_key_eq(f->fn_key, key)) {
 546                 del_fp = fp;
 547                 fp = &f->fn_next;
 548                 f = *fp;
 549                 goto create;
 550         }
 551
 552         DN_FIB_SCAN_KEY(f, fp, key) {
 553                 if (fi->fib_priority <= DN_FIB_INFO(f)->fib_priority)
 554                         break;
 555         }
 556
 557         if (f && dn_key_eq(f->fn_key, key) &&
 558                         fi->fib_priority == DN_FIB_INFO(f)->fib_priority) {
 559                 struct dn_fib_node **ins_fp;
 560
 561                 err = -EEXIST;
 562                 if (n->nlmsg_flags & NLM_F_EXCL)
 563                         goto out;
 564
 565                 if (n->nlmsg_flags & NLM_F_REPLACE) {
 566                         del_fp = fp;
 567                         fp = &f->fn_next;
 568                         f = *fp;
 569                         goto replace;
 570                 }
 571
 572                 ins_fp = fp;
 573                 err = -EEXIST;
 574
 575                 DN_FIB_SCAN_KEY(f, fp, key) {
 576                         if (fi->fib_priority != DN_FIB_INFO(f)->fib_priority)
 577                                 break;
 578                         if (f->fn_type == type && f->fn_scope == r->rtm_scope
 579                                         && DN_FIB_INFO(f) == fi)
 580                                 goto out;
 581                 }
 582
 583                 if (!(n->nlmsg_flags & NLM_F_APPEND)) {
 584                         fp = ins_fp;
 585                         f = *fp;
 586                 }
 587         }
 588
 589 create:
 590         err = -ENOENT;
 591         if (!(n->nlmsg_flags & NLM_F_CREATE))
 592                 goto out;
 593
 594 replace:
 595         err = -ENOBUFS;
 596         new_f = kmem_cache_zalloc(dn_hash_kmem, GFP_KERNEL);
 597         if (new_f == NULL)
 598                 goto out;
 599
 600         new_f->fn_key = key;
 601         new_f->fn_type = type;
 602         new_f->fn_scope = r->rtm_scope;
 603         DN_FIB_INFO(new_f) = fi;
 604
 605         new_f->fn_next = f;
 606         write_lock_bh(&dn_fib_tables_lock);
 607         *fp = new_f;
 608         write_unlock_bh(&dn_fib_tables_lock);
 609         dz->dz_nent++;
 610
 611         if (del_fp) {
 612                 f = *del_fp;
 613                 write_lock_bh(&dn_fib_tables_lock);
 614                 *del_fp = f->fn_next;
 615                 write_unlock_bh(&dn_fib_tables_lock);
 616
 617                 if (!(f->fn_state & DN_S_ZOMBIE))
 618                         dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 619                 if (f->fn_state & DN_S_ACCESSED)
 620                         dn_rt_cache_flush(-1);
 621                 dn_free_node(f);
 622                 dz->dz_nent--;
 623         } else {
 624                 dn_rt_cache_flush(-1);
 625         }
 626
 627         dn_rtmsg_fib(RTM_NEWROUTE, new_f, z, tb->n, n, req);
 628
 629         return 0;
 630 out:
 631         dn_fib_release_info(fi);
 632         return err;
 633 }
 634
 635
 636 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)
 637 {
 638         struct dn_hash *table = (struct dn_hash*)tb->data;
 639         struct dn_fib_node **fp, **del_fp, *f;
 640         int z = r->rtm_dst_len;
 641         struct dn_zone *dz;
 642         dn_fib_key_t key;
 643         int matched;
 644
 645
 646         if (z > 16)
 647                 return -EINVAL;
 648
 649         if ((dz = table->dh_zones[z]) == NULL)
 650                 return -ESRCH;
 651
 652         dz_key_0(key);
 653         if (rta->rta_dst) {
 654                 __le16 dst;
 655                 memcpy(&dst, rta->rta_dst, 2);
 656                 if (dst & ~DZ_MASK(dz))
 657                         return -EINVAL;
 658                 key = dz_key(dst, dz);
 659         }
 660
 661         fp = dn_chain_p(key, dz);
 662
 663         DN_FIB_SCAN(f, fp) {
 664                 if (dn_key_eq(f->fn_key, key))
 665                         break;
 666                 if (dn_key_leq(key, f->fn_key))
 667                         return -ESRCH;
 668         }
 669
 670         matched = 0;
 671         del_fp = NULL;
 672         DN_FIB_SCAN_KEY(f, fp, key) {
 673                 struct dn_fib_info *fi = DN_FIB_INFO(f);
 674
 675                 if (f->fn_state & DN_S_ZOMBIE)
 676                         return -ESRCH;
 677
 678                 matched++;
 679
 680                 if (del_fp == NULL &&
 681                                 (!r->rtm_type || f->fn_type == r->rtm_type) &&
 682                                 (r->rtm_scope == RT_SCOPE_NOWHERE || f->fn_scope == r->rtm_scope) &&
 683                                 (!r->rtm_protocol ||
 684                                         fi->fib_protocol == r->rtm_protocol) &&
 685                                 dn_fib_nh_match(r, n, rta, fi) == 0)
 686                         del_fp = fp;
 687         }
 688
 689         if (del_fp) {
 690                 f = *del_fp;
 691                 dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 692
 693                 if (matched != 1) {
 694                         write_lock_bh(&dn_fib_tables_lock);
 695                         *del_fp = f->fn_next;
 696                         write_unlock_bh(&dn_fib_tables_lock);
 697
 698                         if (f->fn_state & DN_S_ACCESSED)
 699                                 dn_rt_cache_flush(-1);
 700                         dn_free_node(f);
 701                         dz->dz_nent--;
 702                 } else {
 703                         f->fn_state |= DN_S_ZOMBIE;
 704                         if (f->fn_state & DN_S_ACCESSED) {
 705                                 f->fn_state &= ~DN_S_ACCESSED;
 706                                 dn_rt_cache_flush(-1);
 707                         }
 708                         if (++dn_fib_hash_zombies > 128)
 709                                 dn_fib_flush();
 710                 }
 711
 712                 return 0;
 713         }
 714
 715         return -ESRCH;
 716 }
 717
 718 static inline int dn_flush_list(struct dn_fib_node **fp, int z, struct dn_hash *table)
 719 {
 720         int found = 0;
 721         struct dn_fib_node *f;
 722
 723         while((f = *fp) != NULL) {
 724                 struct dn_fib_info *fi = DN_FIB_INFO(f);
 725
 726                 if (fi && ((f->fn_state & DN_S_ZOMBIE) || (fi->fib_flags & RTNH_F_DEAD))) {
 727                         write_lock_bh(&dn_fib_tables_lock);
 728                         *fp = f->fn_next;
 729                         write_unlock_bh(&dn_fib_tables_lock);
 730
 731                         dn_free_node(f);
 732                         found++;
 733                         continue;
 734                 }
 735                 fp = &f->fn_next;
 736         }
 737
 738         return found;
 739 }
 740
 741 static int dn_fib_table_flush(struct dn_fib_table *tb)
 742 {
 743         struct dn_hash *table = (struct dn_hash *)tb->data;
 744         struct dn_zone *dz;
 745         int found = 0;
 746
 747         dn_fib_hash_zombies = 0;
 748         for(dz = table->dh_zone_list; dz; dz = dz->dz_next) {
 749                 int i;
 750                 int tmp = 0;
 751                 for(i = dz->dz_divisor-1; i >= 0; i--)
 752                         tmp += dn_flush_list(&dz->dz_hash[i], dz->dz_order, table);
 753                 dz->dz_nent -= tmp;
 754                 found += tmp;
 755         }
 756
 757         return found;
 758 }
 759
 760 static int dn_fib_table_lookup(struct dn_fib_table *tb, const struct flowi *flp, struct dn_fib_res *res)
 761 {
 762         int err;
 763         struct dn_zone *dz;
 764         struct dn_hash *t = (struct dn_hash *)tb->data;
 765
 766         read_lock(&dn_fib_tables_lock);
 767         for(dz = t->dh_zone_list; dz; dz = dz->dz_next) {
 768                 struct dn_fib_node *f;
 769                 dn_fib_key_t k = dz_key(flp->fld_dst, dz);
 770
 771                 for(f = dz_chain(k, dz); f; f = f->fn_next) {
 772                         if (!dn_key_eq(k, f->fn_key)) {
 773                                 if (dn_key_leq(k, f->fn_key))
 774                                         break;
 775                                 else
 776                                         continue;
 777                         }
 778
 779                         f->fn_state |= DN_S_ACCESSED;
 780
 781                         if (f->fn_state&DN_S_ZOMBIE)
 782                                 continue;
 783
 784                         if (f->fn_scope < flp->fld_scope)
 785                                 continue;
 786
 787                         err = dn_fib_semantic_match(f->fn_type, DN_FIB_INFO(f), flp, res);
 788
 789                         if (err == 0) {
 790                                 res->type = f->fn_type;
 791                                 res->scope = f->fn_scope;
 792                                 res->prefixlen = dz->dz_order;
 793                                 goto out;
 794                         }
 795                         if (err < 0)
 796                                 goto out;
 797                 }
 798         }
 799         err = 1;
 800 out:
 801         read_unlock(&dn_fib_tables_lock);
 802         return err;
 803 }
 804
 805
 806 struct dn_fib_table *dn_fib_get_table(u32 n, int create)
 807 {
 808         struct dn_fib_table *t;
 809         struct hlist_node *node;
 810         unsigned int h;
 811
 812         if (n < RT_TABLE_MIN)
 813                 return NULL;
 814
 815         if (n > RT_TABLE_MAX)
 816                 return NULL;
 817
 818         h = n & (DN_FIB_TABLE_HASHSZ - 1);
 819         rcu_read_lock();
 820         hlist_for_each_entry_rcu(t, node, &dn_fib_table_hash[h], hlist) {
 821                 if (t->n == n) {
 822                         rcu_read_unlock();
 823                         return t;
 824                 }
 825         }
 826         rcu_read_unlock();
 827
 828         if (!create)
 829                 return NULL;
 830
 831         if (in_interrupt() && net_ratelimit()) {
 832                 printk(KERN_DEBUG "DECnet: BUG! Attempt to create routing table from interrupt\n");
 833                 return NULL;
 834         }
 835
 836         t = kzalloc(sizeof(struct dn_fib_table) + sizeof(struct dn_hash),
 837                     GFP_KERNEL);
 838         if (t == NULL)
 839                 return NULL;
 840
 841         t->n = n;
 842         t->insert = dn_fib_table_insert;
 843         t->delete = dn_fib_table_delete;
 844         t->lookup = dn_fib_table_lookup;
 845         t->flush  = dn_fib_table_flush;
 846         t->dump = dn_fib_table_dump;
 847         hlist_add_head_rcu(&t->hlist, &dn_fib_table_hash[h]);
 848
 849         return t;
 850 }
 851
 852 struct dn_fib_table *dn_fib_empty_table(void)
 853 {
 854         u32 id;
 855
 856         for(id = RT_TABLE_MIN; id <= RT_TABLE_MAX; id++)
 857                 if (dn_fib_get_table(id, 0) == NULL)
 858                         return dn_fib_get_table(id, 1);
 859         return NULL;
 860 }
 861
 862 void dn_fib_flush(void)
 863 {
 864         int flushed = 0;
 865         struct dn_fib_table *tb;
 866         struct hlist_node *node;
 867         unsigned int h;
 868
 869         for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
 870                 hlist_for_each_entry(tb, node, &dn_fib_table_hash[h], hlist)
 871                         flushed += tb->flush(tb);
 872         }
 873
 874         if (flushed)
 875                 dn_rt_cache_flush(-1);
 876 }
 877
 878 void __init dn_fib_table_init(void)
 879 {
 880         dn_hash_kmem = kmem_cache_create("dn_fib_info_cache",
 881                                         sizeof(struct dn_fib_info),
 882                                         0, SLAB_HWCACHE_ALIGN,
 883                                         NULL, NULL);
 884 }
 885
 886 void __exit dn_fib_table_cleanup(void)
 887 {
 888         struct dn_fib_table *t;
 889         struct hlist_node *node, *next;
 890         unsigned int h;
 891
 892         write_lock(&dn_fib_tables_lock);
 893         for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
 894                 hlist_for_each_entry_safe(t, node, next, &dn_fib_table_hash[h],
 895                                           hlist) {
 896                         hlist_del(&t->hlist);
 897                         kfree(t);
 898                 }
 899         }
 900         write_unlock(&dn_fib_tables_lock);
 901 }