linux/net/decnet/dn_table.c
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   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/netlink.h>
  32#include <net/dst.h>
  33#include <net/flow.h>
  34#include <net/fib_rules.h>
  35#include <net/dn.h>
  36#include <net/dn_route.h>
  37#include <net/dn_fib.h>
  38#include <net/dn_neigh.h>
  39#include <net/dn_dev.h>
  40
  41struct dn_zone
  42{
  43        struct dn_zone          *dz_next;
  44        struct dn_fib_node      **dz_hash;
  45        int                     dz_nent;
  46        int                     dz_divisor;
  47        u32                     dz_hashmask;
  48#define DZ_HASHMASK(dz) ((dz)->dz_hashmask)
  49        int                     dz_order;
  50        __le16                  dz_mask;
  51#define DZ_MASK(dz)     ((dz)->dz_mask)
  52};
  53
  54struct dn_hash
  55{
  56        struct dn_zone  *dh_zones[17];
  57        struct dn_zone  *dh_zone_list;
  58};
  59
  60#define dz_key_0(key)           ((key).datum = 0)
  61#define dz_prefix(key,dz)       ((key).datum)
  62
  63#define for_nexthops(fi) { int nhsel; const struct dn_fib_nh *nh;\
  64        for(nhsel = 0, nh = (fi)->fib_nh; nhsel < (fi)->fib_nhs; nh++, nhsel++)
  65
  66#define endfor_nexthops(fi) }
  67
  68#define DN_MAX_DIVISOR 1024
  69#define DN_S_ZOMBIE 1
  70#define DN_S_ACCESSED 2
  71
  72#define DN_FIB_SCAN(f, fp) \
  73for( ; ((f) = *(fp)) != NULL; (fp) = &(f)->fn_next)
  74
  75#define DN_FIB_SCAN_KEY(f, fp, key) \
  76for( ; ((f) = *(fp)) != NULL && dn_key_eq((f)->fn_key, (key)); (fp) = &(f)->fn_next)
  77
  78#define RT_TABLE_MIN 1
  79#define DN_FIB_TABLE_HASHSZ 256
  80static struct hlist_head dn_fib_table_hash[DN_FIB_TABLE_HASHSZ];
  81static DEFINE_RWLOCK(dn_fib_tables_lock);
  82
  83static struct kmem_cache *dn_hash_kmem __read_mostly;
  84static int dn_fib_hash_zombies;
  85
  86static inline dn_fib_idx_t dn_hash(dn_fib_key_t key, struct dn_zone *dz)
  87{
  88        u16 h = le16_to_cpu(key.datum)>>(16 - dz->dz_order);
  89        h ^= (h >> 10);
  90        h ^= (h >> 6);
  91        h &= DZ_HASHMASK(dz);
  92        return *(dn_fib_idx_t *)&h;
  93}
  94
  95static inline dn_fib_key_t dz_key(__le16 dst, struct dn_zone *dz)
  96{
  97        dn_fib_key_t k;
  98        k.datum = dst & DZ_MASK(dz);
  99        return k;
 100}
 101
 102static inline struct dn_fib_node **dn_chain_p(dn_fib_key_t key, struct dn_zone *dz)
 103{
 104        return &dz->dz_hash[dn_hash(key, dz).datum];
 105}
 106
 107static inline struct dn_fib_node *dz_chain(dn_fib_key_t key, struct dn_zone *dz)
 108{
 109        return dz->dz_hash[dn_hash(key, dz).datum];
 110}
 111
 112static inline int dn_key_eq(dn_fib_key_t a, dn_fib_key_t b)
 113{
 114        return a.datum == b.datum;
 115}
 116
 117static inline int dn_key_leq(dn_fib_key_t a, dn_fib_key_t b)
 118{
 119        return a.datum <= b.datum;
 120}
 121
 122static inline void dn_rebuild_zone(struct dn_zone *dz,
 123                                   struct dn_fib_node **old_ht,
 124                                   int old_divisor)
 125{
 126        int i;
 127        struct dn_fib_node *f, **fp, *next;
 128
 129        for(i = 0; i < old_divisor; i++) {
 130                for(f = old_ht[i]; f; f = f->fn_next) {
 131                        next = f->fn_next;
 132                        for(fp = dn_chain_p(f->fn_key, dz);
 133                                *fp && dn_key_leq((*fp)->fn_key, f->fn_key);
 134                                fp = &(*fp)->fn_next)
 135                                /* NOTHING */;
 136                        f->fn_next = *fp;
 137                        *fp = f;
 138                }
 139        }
 140}
 141
 142static void dn_rehash_zone(struct dn_zone *dz)
 143{
 144        struct dn_fib_node **ht, **old_ht;
 145        int old_divisor, new_divisor;
 146        u32 new_hashmask;
 147
 148        old_divisor = dz->dz_divisor;
 149
 150        switch(old_divisor) {
 151                case 16:
 152                        new_divisor = 256;
 153                        new_hashmask = 0xFF;
 154                        break;
 155                default:
 156                        printk(KERN_DEBUG "DECnet: dn_rehash_zone: BUG! %d\n", old_divisor);
 157                case 256:
 158                        new_divisor = 1024;
 159                        new_hashmask = 0x3FF;
 160                        break;
 161        }
 162
 163        ht = kcalloc(new_divisor, sizeof(struct dn_fib_node*), GFP_KERNEL);
 164        if (ht == NULL)
 165                return;
 166
 167        write_lock_bh(&dn_fib_tables_lock);
 168        old_ht = dz->dz_hash;
 169        dz->dz_hash = ht;
 170        dz->dz_hashmask = new_hashmask;
 171        dz->dz_divisor = new_divisor;
 172        dn_rebuild_zone(dz, old_ht, old_divisor);
 173        write_unlock_bh(&dn_fib_tables_lock);
 174        kfree(old_ht);
 175}
 176
 177static void dn_free_node(struct dn_fib_node *f)
 178{
 179        dn_fib_release_info(DN_FIB_INFO(f));
 180        kmem_cache_free(dn_hash_kmem, f);
 181}
 182
 183
 184static struct dn_zone *dn_new_zone(struct dn_hash *table, int z)
 185{
 186        int i;
 187        struct dn_zone *dz = kzalloc(sizeof(struct dn_zone), GFP_KERNEL);
 188        if (!dz)
 189                return NULL;
 190
 191        if (z) {
 192                dz->dz_divisor = 16;
 193                dz->dz_hashmask = 0x0F;
 194        } else {
 195                dz->dz_divisor = 1;
 196                dz->dz_hashmask = 0;
 197        }
 198
 199        dz->dz_hash = kcalloc(dz->dz_divisor, sizeof(struct dn_fib_node *), GFP_KERNEL);
 200        if (!dz->dz_hash) {
 201                kfree(dz);
 202                return NULL;
 203        }
 204
 205        dz->dz_order = z;
 206        dz->dz_mask = dnet_make_mask(z);
 207
 208        for(i = z + 1; i <= 16; i++)
 209                if (table->dh_zones[i])
 210                        break;
 211
 212        write_lock_bh(&dn_fib_tables_lock);
 213        if (i>16) {
 214                dz->dz_next = table->dh_zone_list;
 215                table->dh_zone_list = dz;
 216        } else {
 217                dz->dz_next = table->dh_zones[i]->dz_next;
 218                table->dh_zones[i]->dz_next = dz;
 219        }
 220        table->dh_zones[z] = dz;
 221        write_unlock_bh(&dn_fib_tables_lock);
 222        return dz;
 223}
 224
 225
 226static int dn_fib_nh_match(struct rtmsg *r, struct nlmsghdr *nlh, struct dn_kern_rta *rta, struct dn_fib_info *fi)
 227{
 228        struct rtnexthop *nhp;
 229        int nhlen;
 230
 231        if (rta->rta_priority && *rta->rta_priority != fi->fib_priority)
 232                return 1;
 233
 234        if (rta->rta_oif || rta->rta_gw) {
 235                if ((!rta->rta_oif || *rta->rta_oif == fi->fib_nh->nh_oif) &&
 236                    (!rta->rta_gw  || memcmp(rta->rta_gw, &fi->fib_nh->nh_gw, 2) == 0))
 237                        return 0;
 238                return 1;
 239        }
 240
 241        if (rta->rta_mp == NULL)
 242                return 0;
 243
 244        nhp = RTA_DATA(rta->rta_mp);
 245        nhlen = RTA_PAYLOAD(rta->rta_mp);
 246
 247        for_nexthops(fi) {
 248                int attrlen = nhlen - sizeof(struct rtnexthop);
 249                __le16 gw;
 250
 251                if (attrlen < 0 || (nhlen -= nhp->rtnh_len) < 0)
 252                        return -EINVAL;
 253                if (nhp->rtnh_ifindex && nhp->rtnh_ifindex != nh->nh_oif)
 254                        return 1;
 255                if (attrlen) {
 256                        gw = dn_fib_get_attr16(RTNH_DATA(nhp), attrlen, RTA_GATEWAY);
 257
 258                        if (gw && gw != nh->nh_gw)
 259                                return 1;
 260                }
 261                nhp = RTNH_NEXT(nhp);
 262        } endfor_nexthops(fi);
 263
 264        return 0;
 265}
 266
 267static inline size_t dn_fib_nlmsg_size(struct dn_fib_info *fi)
 268{
 269        size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg))
 270                         + nla_total_size(4) /* RTA_TABLE */
 271                         + nla_total_size(2) /* RTA_DST */
 272                         + nla_total_size(4); /* RTA_PRIORITY */
 273
 274        /* space for nested metrics */
 275        payload += nla_total_size((RTAX_MAX * nla_total_size(4)));
 276
 277        if (fi->fib_nhs) {
 278                /* Also handles the special case fib_nhs == 1 */
 279
 280                /* each nexthop is packed in an attribute */
 281                size_t nhsize = nla_total_size(sizeof(struct rtnexthop));
 282
 283                /* may contain a gateway attribute */
 284                nhsize += nla_total_size(4);
 285
 286                /* all nexthops are packed in a nested attribute */
 287                payload += nla_total_size(fi->fib_nhs * nhsize);
 288        }
 289
 290        return payload;
 291}
 292
 293static int dn_fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
 294                        u32 tb_id, u8 type, u8 scope, void *dst, int dst_len,
 295                        struct dn_fib_info *fi, unsigned int flags)
 296{
 297        struct rtmsg *rtm;
 298        struct nlmsghdr *nlh;
 299        unsigned char *b = skb_tail_pointer(skb);
 300
 301        nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*rtm), flags);
 302        rtm = NLMSG_DATA(nlh);
 303        rtm->rtm_family = AF_DECnet;
 304        rtm->rtm_dst_len = dst_len;
 305        rtm->rtm_src_len = 0;
 306        rtm->rtm_tos = 0;
 307        rtm->rtm_table = tb_id;
 308        RTA_PUT_U32(skb, RTA_TABLE, tb_id);
 309        rtm->rtm_flags = fi->fib_flags;
 310        rtm->rtm_scope = scope;
 311        rtm->rtm_type  = type;
 312        if (rtm->rtm_dst_len)
 313                RTA_PUT(skb, RTA_DST, 2, dst);
 314        rtm->rtm_protocol = fi->fib_protocol;
 315        if (fi->fib_priority)
 316                RTA_PUT(skb, RTA_PRIORITY, 4, &fi->fib_priority);
 317        if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0)
 318                goto rtattr_failure;
 319        if (fi->fib_nhs == 1) {
 320                if (fi->fib_nh->nh_gw)
 321                        RTA_PUT(skb, RTA_GATEWAY, 2, &fi->fib_nh->nh_gw);
 322                if (fi->fib_nh->nh_oif)
 323                        RTA_PUT(skb, RTA_OIF, sizeof(int), &fi->fib_nh->nh_oif);
 324        }
 325        if (fi->fib_nhs > 1) {
 326                struct rtnexthop *nhp;
 327                struct rtattr *mp_head;
 328                if (skb_tailroom(skb) <= RTA_SPACE(0))
 329                        goto rtattr_failure;
 330                mp_head = (struct rtattr *)skb_put(skb, RTA_SPACE(0));
 331
 332                for_nexthops(fi) {
 333                        if (skb_tailroom(skb) < RTA_ALIGN(RTA_ALIGN(sizeof(*nhp)) + 4))
 334                                goto rtattr_failure;
 335                        nhp = (struct rtnexthop *)skb_put(skb, RTA_ALIGN(sizeof(*nhp)));
 336                        nhp->rtnh_flags = nh->nh_flags & 0xFF;
 337                        nhp->rtnh_hops = nh->nh_weight - 1;
 338                        nhp->rtnh_ifindex = nh->nh_oif;
 339                        if (nh->nh_gw)
 340                                RTA_PUT(skb, RTA_GATEWAY, 2, &nh->nh_gw);
 341                        nhp->rtnh_len = skb_tail_pointer(skb) - (unsigned char *)nhp;
 342                } endfor_nexthops(fi);
 343                mp_head->rta_type = RTA_MULTIPATH;
 344                mp_head->rta_len = skb_tail_pointer(skb) - (u8 *)mp_head;
 345        }
 346
 347        nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 348        return skb->len;
 349
 350
 351nlmsg_failure:
 352rtattr_failure:
 353        nlmsg_trim(skb, b);
 354        return -EMSGSIZE;
 355}
 356
 357
 358static void dn_rtmsg_fib(int event, struct dn_fib_node *f, int z, u32 tb_id,
 359                        struct nlmsghdr *nlh, struct netlink_skb_parms *req)
 360{
 361        struct sk_buff *skb;
 362        u32 pid = req ? req->pid : 0;
 363        int err = -ENOBUFS;
 364
 365        skb = nlmsg_new(dn_fib_nlmsg_size(DN_FIB_INFO(f)), GFP_KERNEL);
 366        if (skb == NULL)
 367                goto errout;
 368
 369        err = dn_fib_dump_info(skb, pid, nlh->nlmsg_seq, event, tb_id,
 370                               f->fn_type, f->fn_scope, &f->fn_key, z,
 371                               DN_FIB_INFO(f), 0);
 372        if (err < 0) {
 373                /* -EMSGSIZE implies BUG in dn_fib_nlmsg_size() */
 374                WARN_ON(err == -EMSGSIZE);
 375                kfree_skb(skb);
 376                goto errout;
 377        }
 378        err = rtnl_notify(skb, &init_net, pid, RTNLGRP_DECnet_ROUTE, nlh, GFP_KERNEL);
 379errout:
 380        if (err < 0)
 381                rtnl_set_sk_err(&init_net, RTNLGRP_DECnet_ROUTE, err);
 382}
 383
 384static __inline__ int dn_hash_dump_bucket(struct sk_buff *skb,
 385                                struct netlink_callback *cb,
 386                                struct dn_fib_table *tb,
 387                                struct dn_zone *dz,
 388                                struct dn_fib_node *f)
 389{
 390        int i, s_i;
 391
 392        s_i = cb->args[4];
 393        for(i = 0; f; i++, f = f->fn_next) {
 394                if (i < s_i)
 395                        continue;
 396                if (f->fn_state & DN_S_ZOMBIE)
 397                        continue;
 398                if (dn_fib_dump_info(skb, NETLINK_CB(cb->skb).pid,
 399                                cb->nlh->nlmsg_seq,
 400                                RTM_NEWROUTE,
 401                                tb->n,
 402                                (f->fn_state & DN_S_ZOMBIE) ? 0 : f->fn_type,
 403                                f->fn_scope, &f->fn_key, dz->dz_order,
 404                                f->fn_info, NLM_F_MULTI) < 0) {
 405                        cb->args[4] = i;
 406                        return -1;
 407                }
 408        }
 409        cb->args[4] = i;
 410        return skb->len;
 411}
 412
 413static __inline__ int dn_hash_dump_zone(struct sk_buff *skb,
 414                                struct netlink_callback *cb,
 415                                struct dn_fib_table *tb,
 416                                struct dn_zone *dz)
 417{
 418        int h, s_h;
 419
 420        s_h = cb->args[3];
 421        for(h = 0; h < dz->dz_divisor; h++) {
 422                if (h < s_h)
 423                        continue;
 424                if (h > s_h)
 425                        memset(&cb->args[4], 0, sizeof(cb->args) - 4*sizeof(cb->args[0]));
 426                if (dz->dz_hash == NULL || dz->dz_hash[h] == NULL)
 427                        continue;
 428                if (dn_hash_dump_bucket(skb, cb, tb, dz, dz->dz_hash[h]) < 0) {
 429                        cb->args[3] = h;
 430                        return -1;
 431                }
 432        }
 433        cb->args[3] = h;
 434        return skb->len;
 435}
 436
 437static int dn_fib_table_dump(struct dn_fib_table *tb, struct sk_buff *skb,
 438                                struct netlink_callback *cb)
 439{
 440        int m, s_m;
 441        struct dn_zone *dz;
 442        struct dn_hash *table = (struct dn_hash *)tb->data;
 443
 444        s_m = cb->args[2];
 445        read_lock(&dn_fib_tables_lock);
 446        for(dz = table->dh_zone_list, m = 0; dz; dz = dz->dz_next, m++) {
 447                if (m < s_m)
 448                        continue;
 449                if (m > s_m)
 450                        memset(&cb->args[3], 0, sizeof(cb->args) - 3*sizeof(cb->args[0]));
 451
 452                if (dn_hash_dump_zone(skb, cb, tb, dz) < 0) {
 453                        cb->args[2] = m;
 454                        read_unlock(&dn_fib_tables_lock);
 455                        return -1;
 456                }
 457        }
 458        read_unlock(&dn_fib_tables_lock);
 459        cb->args[2] = m;
 460
 461        return skb->len;
 462}
 463
 464int dn_fib_dump(struct sk_buff *skb, struct netlink_callback *cb)
 465{
 466        struct net *net = sock_net(skb->sk);
 467        unsigned int h, s_h;
 468        unsigned int e = 0, s_e;
 469        struct dn_fib_table *tb;
 470        struct hlist_node *node;
 471        int dumped = 0;
 472
 473        if (net != &init_net)
 474                return 0;
 475
 476        if (NLMSG_PAYLOAD(cb->nlh, 0) >= sizeof(struct rtmsg) &&
 477                ((struct rtmsg *)NLMSG_DATA(cb->nlh))->rtm_flags&RTM_F_CLONED)
 478                        return dn_cache_dump(skb, cb);
 479
 480        s_h = cb->args[0];
 481        s_e = cb->args[1];
 482
 483        for (h = s_h; h < DN_FIB_TABLE_HASHSZ; h++, s_h = 0) {
 484                e = 0;
 485                hlist_for_each_entry(tb, node, &dn_fib_table_hash[h], hlist) {
 486                        if (e < s_e)
 487                                goto next;
 488                        if (dumped)
 489                                memset(&cb->args[2], 0, sizeof(cb->args) -
 490                                                 2 * sizeof(cb->args[0]));
 491                        if (tb->dump(tb, skb, cb) < 0)
 492                                goto out;
 493                        dumped = 1;
 494next:
 495                        e++;
 496                }
 497        }
 498out:
 499        cb->args[1] = e;
 500        cb->args[0] = h;
 501
 502        return skb->len;
 503}
 504
 505static 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)
 506{
 507        struct dn_hash *table = (struct dn_hash *)tb->data;
 508        struct dn_fib_node *new_f, *f, **fp, **del_fp;
 509        struct dn_zone *dz;
 510        struct dn_fib_info *fi;
 511        int z = r->rtm_dst_len;
 512        int type = r->rtm_type;
 513        dn_fib_key_t key;
 514        int err;
 515
 516        if (z > 16)
 517                return -EINVAL;
 518
 519        dz = table->dh_zones[z];
 520        if (!dz && !(dz = dn_new_zone(table, z)))
 521                return -ENOBUFS;
 522
 523        dz_key_0(key);
 524        if (rta->rta_dst) {
 525                __le16 dst;
 526                memcpy(&dst, rta->rta_dst, 2);
 527                if (dst & ~DZ_MASK(dz))
 528                        return -EINVAL;
 529                key = dz_key(dst, dz);
 530        }
 531
 532        if ((fi = dn_fib_create_info(r, rta, n, &err)) == NULL)
 533                return err;
 534
 535        if (dz->dz_nent > (dz->dz_divisor << 2) &&
 536                        dz->dz_divisor > DN_MAX_DIVISOR &&
 537                        (z==16 || (1<<z) > dz->dz_divisor))
 538                dn_rehash_zone(dz);
 539
 540        fp = dn_chain_p(key, dz);
 541
 542        DN_FIB_SCAN(f, fp) {
 543                if (dn_key_leq(key, f->fn_key))
 544                        break;
 545        }
 546
 547        del_fp = NULL;
 548
 549        if (f && (f->fn_state & DN_S_ZOMBIE) &&
 550                        dn_key_eq(f->fn_key, key)) {
 551                del_fp = fp;
 552                fp = &f->fn_next;
 553                f = *fp;
 554                goto create;
 555        }
 556
 557        DN_FIB_SCAN_KEY(f, fp, key) {
 558                if (fi->fib_priority <= DN_FIB_INFO(f)->fib_priority)
 559                        break;
 560        }
 561
 562        if (f && dn_key_eq(f->fn_key, key) &&
 563                        fi->fib_priority == DN_FIB_INFO(f)->fib_priority) {
 564                struct dn_fib_node **ins_fp;
 565
 566                err = -EEXIST;
 567                if (n->nlmsg_flags & NLM_F_EXCL)
 568                        goto out;
 569
 570                if (n->nlmsg_flags & NLM_F_REPLACE) {
 571                        del_fp = fp;
 572                        fp = &f->fn_next;
 573                        f = *fp;
 574                        goto replace;
 575                }
 576
 577                ins_fp = fp;
 578                err = -EEXIST;
 579
 580                DN_FIB_SCAN_KEY(f, fp, key) {
 581                        if (fi->fib_priority != DN_FIB_INFO(f)->fib_priority)
 582                                break;
 583                        if (f->fn_type == type && f->fn_scope == r->rtm_scope
 584                                        && DN_FIB_INFO(f) == fi)
 585                                goto out;
 586                }
 587
 588                if (!(n->nlmsg_flags & NLM_F_APPEND)) {
 589                        fp = ins_fp;
 590                        f = *fp;
 591                }
 592        }
 593
 594create:
 595        err = -ENOENT;
 596        if (!(n->nlmsg_flags & NLM_F_CREATE))
 597                goto out;
 598
 599replace:
 600        err = -ENOBUFS;
 601        new_f = kmem_cache_zalloc(dn_hash_kmem, GFP_KERNEL);
 602        if (new_f == NULL)
 603                goto out;
 604
 605        new_f->fn_key = key;
 606        new_f->fn_type = type;
 607        new_f->fn_scope = r->rtm_scope;
 608        DN_FIB_INFO(new_f) = fi;
 609
 610        new_f->fn_next = f;
 611        write_lock_bh(&dn_fib_tables_lock);
 612        *fp = new_f;
 613        write_unlock_bh(&dn_fib_tables_lock);
 614        dz->dz_nent++;
 615
 616        if (del_fp) {
 617                f = *del_fp;
 618                write_lock_bh(&dn_fib_tables_lock);
 619                *del_fp = f->fn_next;
 620                write_unlock_bh(&dn_fib_tables_lock);
 621
 622                if (!(f->fn_state & DN_S_ZOMBIE))
 623                        dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 624                if (f->fn_state & DN_S_ACCESSED)
 625                        dn_rt_cache_flush(-1);
 626                dn_free_node(f);
 627                dz->dz_nent--;
 628        } else {
 629                dn_rt_cache_flush(-1);
 630        }
 631
 632        dn_rtmsg_fib(RTM_NEWROUTE, new_f, z, tb->n, n, req);
 633
 634        return 0;
 635out:
 636        dn_fib_release_info(fi);
 637        return err;
 638}
 639
 640
 641static 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)
 642{
 643        struct dn_hash *table = (struct dn_hash*)tb->data;
 644        struct dn_fib_node **fp, **del_fp, *f;
 645        int z = r->rtm_dst_len;
 646        struct dn_zone *dz;
 647        dn_fib_key_t key;
 648        int matched;
 649
 650
 651        if (z > 16)
 652                return -EINVAL;
 653
 654        if ((dz = table->dh_zones[z]) == NULL)
 655                return -ESRCH;
 656
 657        dz_key_0(key);
 658        if (rta->rta_dst) {
 659                __le16 dst;
 660                memcpy(&dst, rta->rta_dst, 2);
 661                if (dst & ~DZ_MASK(dz))
 662                        return -EINVAL;
 663                key = dz_key(dst, dz);
 664        }
 665
 666        fp = dn_chain_p(key, dz);
 667
 668        DN_FIB_SCAN(f, fp) {
 669                if (dn_key_eq(f->fn_key, key))
 670                        break;
 671                if (dn_key_leq(key, f->fn_key))
 672                        return -ESRCH;
 673        }
 674
 675        matched = 0;
 676        del_fp = NULL;
 677        DN_FIB_SCAN_KEY(f, fp, key) {
 678                struct dn_fib_info *fi = DN_FIB_INFO(f);
 679
 680                if (f->fn_state & DN_S_ZOMBIE)
 681                        return -ESRCH;
 682
 683                matched++;
 684
 685                if (del_fp == NULL &&
 686                                (!r->rtm_type || f->fn_type == r->rtm_type) &&
 687                                (r->rtm_scope == RT_SCOPE_NOWHERE || f->fn_scope == r->rtm_scope) &&
 688                                (!r->rtm_protocol ||
 689                                        fi->fib_protocol == r->rtm_protocol) &&
 690                                dn_fib_nh_match(r, n, rta, fi) == 0)
 691                        del_fp = fp;
 692        }
 693
 694        if (del_fp) {
 695                f = *del_fp;
 696                dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 697
 698                if (matched != 1) {
 699                        write_lock_bh(&dn_fib_tables_lock);
 700                        *del_fp = f->fn_next;
 701                        write_unlock_bh(&dn_fib_tables_lock);
 702
 703                        if (f->fn_state & DN_S_ACCESSED)
 704                                dn_rt_cache_flush(-1);
 705                        dn_free_node(f);
 706                        dz->dz_nent--;
 707                } else {
 708                        f->fn_state |= DN_S_ZOMBIE;
 709                        if (f->fn_state & DN_S_ACCESSED) {
 710                                f->fn_state &= ~DN_S_ACCESSED;
 711                                dn_rt_cache_flush(-1);
 712                        }
 713                        if (++dn_fib_hash_zombies > 128)
 714                                dn_fib_flush();
 715                }
 716
 717                return 0;
 718        }
 719
 720        return -ESRCH;
 721}
 722
 723static inline int dn_flush_list(struct dn_fib_node **fp, int z, struct dn_hash *table)
 724{
 725        int found = 0;
 726        struct dn_fib_node *f;
 727
 728        while((f = *fp) != NULL) {
 729                struct dn_fib_info *fi = DN_FIB_INFO(f);
 730
 731                if (fi && ((f->fn_state & DN_S_ZOMBIE) || (fi->fib_flags & RTNH_F_DEAD))) {
 732                        write_lock_bh(&dn_fib_tables_lock);
 733                        *fp = f->fn_next;
 734                        write_unlock_bh(&dn_fib_tables_lock);
 735
 736                        dn_free_node(f);
 737                        found++;
 738                        continue;
 739                }
 740                fp = &f->fn_next;
 741        }
 742
 743        return found;
 744}
 745
 746static int dn_fib_table_flush(struct dn_fib_table *tb)
 747{
 748        struct dn_hash *table = (struct dn_hash *)tb->data;
 749        struct dn_zone *dz;
 750        int found = 0;
 751
 752        dn_fib_hash_zombies = 0;
 753        for(dz = table->dh_zone_list; dz; dz = dz->dz_next) {
 754                int i;
 755                int tmp = 0;
 756                for(i = dz->dz_divisor-1; i >= 0; i--)
 757                        tmp += dn_flush_list(&dz->dz_hash[i], dz->dz_order, table);
 758                dz->dz_nent -= tmp;
 759                found += tmp;
 760        }
 761
 762        return found;
 763}
 764
 765static int dn_fib_table_lookup(struct dn_fib_table *tb, const struct flowi *flp, struct dn_fib_res *res)
 766{
 767        int err;
 768        struct dn_zone *dz;
 769        struct dn_hash *t = (struct dn_hash *)tb->data;
 770
 771        read_lock(&dn_fib_tables_lock);
 772        for(dz = t->dh_zone_list; dz; dz = dz->dz_next) {
 773                struct dn_fib_node *f;
 774                dn_fib_key_t k = dz_key(flp->fld_dst, dz);
 775
 776                for(f = dz_chain(k, dz); f; f = f->fn_next) {
 777                        if (!dn_key_eq(k, f->fn_key)) {
 778                                if (dn_key_leq(k, f->fn_key))
 779                                        break;
 780                                else
 781                                        continue;
 782                        }
 783
 784                        f->fn_state |= DN_S_ACCESSED;
 785
 786                        if (f->fn_state&DN_S_ZOMBIE)
 787                                continue;
 788
 789                        if (f->fn_scope < flp->fld_scope)
 790                                continue;
 791
 792                        err = dn_fib_semantic_match(f->fn_type, DN_FIB_INFO(f), flp, res);
 793
 794                        if (err == 0) {
 795                                res->type = f->fn_type;
 796                                res->scope = f->fn_scope;
 797                                res->prefixlen = dz->dz_order;
 798                                goto out;
 799                        }
 800                        if (err < 0)
 801                                goto out;
 802                }
 803        }
 804        err = 1;
 805out:
 806        read_unlock(&dn_fib_tables_lock);
 807        return err;
 808}
 809
 810
 811struct dn_fib_table *dn_fib_get_table(u32 n, int create)
 812{
 813        struct dn_fib_table *t;
 814        struct hlist_node *node;
 815        unsigned int h;
 816
 817        if (n < RT_TABLE_MIN)
 818                return NULL;
 819
 820        if (n > RT_TABLE_MAX)
 821                return NULL;
 822
 823        h = n & (DN_FIB_TABLE_HASHSZ - 1);
 824        rcu_read_lock();
 825        hlist_for_each_entry_rcu(t, node, &dn_fib_table_hash[h], hlist) {
 826                if (t->n == n) {
 827                        rcu_read_unlock();
 828                        return t;
 829                }
 830        }
 831        rcu_read_unlock();
 832
 833        if (!create)
 834                return NULL;
 835
 836        if (in_interrupt() && net_ratelimit()) {
 837                printk(KERN_DEBUG "DECnet: BUG! Attempt to create routing table from interrupt\n");
 838                return NULL;
 839        }
 840
 841        t = kzalloc(sizeof(struct dn_fib_table) + sizeof(struct dn_hash),
 842                    GFP_KERNEL);
 843        if (t == NULL)
 844                return NULL;
 845
 846        t->n = n;
 847        t->insert = dn_fib_table_insert;
 848        t->delete = dn_fib_table_delete;
 849        t->lookup = dn_fib_table_lookup;
 850        t->flush  = dn_fib_table_flush;
 851        t->dump = dn_fib_table_dump;
 852        hlist_add_head_rcu(&t->hlist, &dn_fib_table_hash[h]);
 853
 854        return t;
 855}
 856
 857struct dn_fib_table *dn_fib_empty_table(void)
 858{
 859        u32 id;
 860
 861        for(id = RT_TABLE_MIN; id <= RT_TABLE_MAX; id++)
 862                if (dn_fib_get_table(id, 0) == NULL)
 863                        return dn_fib_get_table(id, 1);
 864        return NULL;
 865}
 866
 867void dn_fib_flush(void)
 868{
 869        int flushed = 0;
 870        struct dn_fib_table *tb;
 871        struct hlist_node *node;
 872        unsigned int h;
 873
 874        for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
 875                hlist_for_each_entry(tb, node, &dn_fib_table_hash[h], hlist)
 876                        flushed += tb->flush(tb);
 877        }
 878
 879        if (flushed)
 880                dn_rt_cache_flush(-1);
 881}
 882
 883void __init dn_fib_table_init(void)
 884{
 885        dn_hash_kmem = kmem_cache_create("dn_fib_info_cache",
 886                                        sizeof(struct dn_fib_info),
 887                                        0, SLAB_HWCACHE_ALIGN,
 888                                        NULL);
 889}
 890
 891void __exit dn_fib_table_cleanup(void)
 892{
 893        struct dn_fib_table *t;
 894        struct hlist_node *node, *next;
 895        unsigned int h;
 896
 897        write_lock(&dn_fib_tables_lock);
 898        for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
 899                hlist_for_each_entry_safe(t, node, next, &dn_fib_table_hash[h],
 900                                          hlist) {
 901                        hlist_del(&t->hlist);
 902                        kfree(t);
 903                }
 904        }
 905        write_unlock(&dn_fib_tables_lock);
 906}
 907