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