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 <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
  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) \
  72for( ; ((f) = *(fp)) != NULL; (fp) = &(f)->fn_next)
  73
  74#define DN_FIB_SCAN_KEY(f, fp, key) \
  75for( ; ((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
  79static struct hlist_head dn_fib_table_hash[DN_FIB_TABLE_HASHSZ];
  80static DEFINE_RWLOCK(dn_fib_tables_lock);
  81
  82static struct kmem_cache *dn_hash_kmem __read_mostly;
  83static int dn_fib_hash_zombies;
  84
  85static inline dn_fib_idx_t dn_hash(dn_fib_key_t key, struct dn_zone *dz)
  86{
  87        u16 h = le16_to_cpu(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
  94static 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
 101static 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
 106static 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
 111static inline int dn_key_eq(dn_fib_key_t a, dn_fib_key_t b)
 112{
 113        return a.datum == b.datum;
 114}
 115
 116static inline int dn_key_leq(dn_fib_key_t a, dn_fib_key_t b)
 117{
 118        return a.datum <= b.datum;
 119}
 120
 121static inline void dn_rebuild_zone(struct dn_zone *dz,
 122                                   struct dn_fib_node **old_ht,
 123                                   int old_divisor)
 124{
 125        struct dn_fib_node *f, **fp, *next;
 126        int i;
 127
 128        for(i = 0; i < old_divisor; i++) {
 129                for(f = old_ht[i]; f; f = 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
 141static 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",
 156                       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 nlattr *attrs[], struct dn_fib_info *fi)
 227{
 228        struct rtnexthop *nhp;
 229        int nhlen;
 230
 231        if (attrs[RTA_PRIORITY] &&
 232            nla_get_u32(attrs[RTA_PRIORITY]) != fi->fib_priority)
 233                return 1;
 234
 235        if (attrs[RTA_OIF] || attrs[RTA_GATEWAY]) {
 236                if ((!attrs[RTA_OIF] || nla_get_u32(attrs[RTA_OIF]) == fi->fib_nh->nh_oif) &&
 237                    (!attrs[RTA_GATEWAY]  || nla_get_le16(attrs[RTA_GATEWAY]) != fi->fib_nh->nh_gw))
 238                        return 0;
 239                return 1;
 240        }
 241
 242        if (!attrs[RTA_MULTIPATH])
 243                return 0;
 244
 245        nhp = nla_data(attrs[RTA_MULTIPATH]);
 246        nhlen = nla_len(attrs[RTA_MULTIPATH]);
 247
 248        for_nexthops(fi) {
 249                int attrlen = nhlen - sizeof(struct rtnexthop);
 250                __le16 gw;
 251
 252                if (attrlen < 0 || (nhlen -= nhp->rtnh_len) < 0)
 253                        return -EINVAL;
 254                if (nhp->rtnh_ifindex && nhp->rtnh_ifindex != nh->nh_oif)
 255                        return 1;
 256                if (attrlen) {
 257                        struct nlattr *gw_attr;
 258
 259                        gw_attr = nla_find((struct nlattr *) (nhp + 1), attrlen, RTA_GATEWAY);
 260                        gw = gw_attr ? nla_get_le16(gw_attr) : 0;
 261
 262                        if (gw && gw != nh->nh_gw)
 263                                return 1;
 264                }
 265                nhp = RTNH_NEXT(nhp);
 266        } endfor_nexthops(fi);
 267
 268        return 0;
 269}
 270
 271static inline size_t dn_fib_nlmsg_size(struct dn_fib_info *fi)
 272{
 273        size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg))
 274                         + nla_total_size(4) /* RTA_TABLE */
 275                         + nla_total_size(2) /* RTA_DST */
 276                         + nla_total_size(4); /* RTA_PRIORITY */
 277
 278        /* space for nested metrics */
 279        payload += nla_total_size((RTAX_MAX * nla_total_size(4)));
 280
 281        if (fi->fib_nhs) {
 282                /* Also handles the special case fib_nhs == 1 */
 283
 284                /* each nexthop is packed in an attribute */
 285                size_t nhsize = nla_total_size(sizeof(struct rtnexthop));
 286
 287                /* may contain a gateway attribute */
 288                nhsize += nla_total_size(4);
 289
 290                /* all nexthops are packed in a nested attribute */
 291                payload += nla_total_size(fi->fib_nhs * nhsize);
 292        }
 293
 294        return payload;
 295}
 296
 297static int dn_fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event,
 298                        u32 tb_id, u8 type, u8 scope, void *dst, int dst_len,
 299                        struct dn_fib_info *fi, unsigned int flags)
 300{
 301        struct rtmsg *rtm;
 302        struct nlmsghdr *nlh;
 303
 304        nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags);
 305        if (!nlh)
 306                return -EMSGSIZE;
 307
 308        rtm = nlmsg_data(nlh);
 309        rtm->rtm_family = AF_DECnet;
 310        rtm->rtm_dst_len = dst_len;
 311        rtm->rtm_src_len = 0;
 312        rtm->rtm_tos = 0;
 313        rtm->rtm_table = tb_id;
 314        rtm->rtm_flags = fi->fib_flags;
 315        rtm->rtm_scope = scope;
 316        rtm->rtm_type  = type;
 317        rtm->rtm_protocol = fi->fib_protocol;
 318
 319        if (nla_put_u32(skb, RTA_TABLE, tb_id) < 0)
 320                goto errout;
 321
 322        if (rtm->rtm_dst_len &&
 323            nla_put(skb, RTA_DST, 2, dst) < 0)
 324                goto errout;
 325
 326        if (fi->fib_priority &&
 327            nla_put_u32(skb, RTA_PRIORITY, fi->fib_priority) < 0)
 328                goto errout;
 329
 330        if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0)
 331                goto errout;
 332
 333        if (fi->fib_nhs == 1) {
 334                if (fi->fib_nh->nh_gw &&
 335                    nla_put_le16(skb, RTA_GATEWAY, fi->fib_nh->nh_gw) < 0)
 336                        goto errout;
 337
 338                if (fi->fib_nh->nh_oif &&
 339                    nla_put_u32(skb, RTA_OIF, fi->fib_nh->nh_oif) < 0)
 340                        goto errout;
 341        }
 342
 343        if (fi->fib_nhs > 1) {
 344                struct rtnexthop *nhp;
 345                struct nlattr *mp_head;
 346
 347                if (!(mp_head = nla_nest_start(skb, RTA_MULTIPATH)))
 348                        goto errout;
 349
 350                for_nexthops(fi) {
 351                        if (!(nhp = nla_reserve_nohdr(skb, sizeof(*nhp))))
 352                                goto errout;
 353
 354                        nhp->rtnh_flags = nh->nh_flags & 0xFF;
 355                        nhp->rtnh_hops = nh->nh_weight - 1;
 356                        nhp->rtnh_ifindex = nh->nh_oif;
 357
 358                        if (nh->nh_gw &&
 359                            nla_put_le16(skb, RTA_GATEWAY, nh->nh_gw) < 0)
 360                                goto errout;
 361
 362                        nhp->rtnh_len = skb_tail_pointer(skb) - (unsigned char *)nhp;
 363                } endfor_nexthops(fi);
 364
 365                nla_nest_end(skb, mp_head);
 366        }
 367
 368        return nlmsg_end(skb, nlh);
 369
 370errout:
 371        nlmsg_cancel(skb, nlh);
 372        return -EMSGSIZE;
 373}
 374
 375
 376static void dn_rtmsg_fib(int event, struct dn_fib_node *f, int z, u32 tb_id,
 377                        struct nlmsghdr *nlh, struct netlink_skb_parms *req)
 378{
 379        struct sk_buff *skb;
 380        u32 portid = req ? req->portid : 0;
 381        int err = -ENOBUFS;
 382
 383        skb = nlmsg_new(dn_fib_nlmsg_size(DN_FIB_INFO(f)), GFP_KERNEL);
 384        if (skb == NULL)
 385                goto errout;
 386
 387        err = dn_fib_dump_info(skb, portid, nlh->nlmsg_seq, event, tb_id,
 388                               f->fn_type, f->fn_scope, &f->fn_key, z,
 389                               DN_FIB_INFO(f), 0);
 390        if (err < 0) {
 391                /* -EMSGSIZE implies BUG in dn_fib_nlmsg_size() */
 392                WARN_ON(err == -EMSGSIZE);
 393                kfree_skb(skb);
 394                goto errout;
 395        }
 396        rtnl_notify(skb, &init_net, portid, RTNLGRP_DECnet_ROUTE, nlh, GFP_KERNEL);
 397        return;
 398errout:
 399        if (err < 0)
 400                rtnl_set_sk_err(&init_net, RTNLGRP_DECnet_ROUTE, err);
 401}
 402
 403static __inline__ int dn_hash_dump_bucket(struct sk_buff *skb,
 404                                struct netlink_callback *cb,
 405                                struct dn_fib_table *tb,
 406                                struct dn_zone *dz,
 407                                struct dn_fib_node *f)
 408{
 409        int i, s_i;
 410
 411        s_i = cb->args[4];
 412        for(i = 0; f; i++, f = f->fn_next) {
 413                if (i < s_i)
 414                        continue;
 415                if (f->fn_state & DN_S_ZOMBIE)
 416                        continue;
 417                if (dn_fib_dump_info(skb, NETLINK_CB(cb->skb).portid,
 418                                cb->nlh->nlmsg_seq,
 419                                RTM_NEWROUTE,
 420                                tb->n,
 421                                (f->fn_state & DN_S_ZOMBIE) ? 0 : f->fn_type,
 422                                f->fn_scope, &f->fn_key, dz->dz_order,
 423                                f->fn_info, NLM_F_MULTI) < 0) {
 424                        cb->args[4] = i;
 425                        return -1;
 426                }
 427        }
 428        cb->args[4] = i;
 429        return skb->len;
 430}
 431
 432static __inline__ int dn_hash_dump_zone(struct sk_buff *skb,
 433                                struct netlink_callback *cb,
 434                                struct dn_fib_table *tb,
 435                                struct dn_zone *dz)
 436{
 437        int h, s_h;
 438
 439        s_h = cb->args[3];
 440        for(h = 0; h < dz->dz_divisor; h++) {
 441                if (h < s_h)
 442                        continue;
 443                if (h > s_h)
 444                        memset(&cb->args[4], 0, sizeof(cb->args) - 4*sizeof(cb->args[0]));
 445                if (dz->dz_hash == NULL || dz->dz_hash[h] == NULL)
 446                        continue;
 447                if (dn_hash_dump_bucket(skb, cb, tb, dz, dz->dz_hash[h]) < 0) {
 448                        cb->args[3] = h;
 449                        return -1;
 450                }
 451        }
 452        cb->args[3] = h;
 453        return skb->len;
 454}
 455
 456static int dn_fib_table_dump(struct dn_fib_table *tb, struct sk_buff *skb,
 457                                struct netlink_callback *cb)
 458{
 459        int m, s_m;
 460        struct dn_zone *dz;
 461        struct dn_hash *table = (struct dn_hash *)tb->data;
 462
 463        s_m = cb->args[2];
 464        read_lock(&dn_fib_tables_lock);
 465        for(dz = table->dh_zone_list, m = 0; dz; dz = dz->dz_next, m++) {
 466                if (m < s_m)
 467                        continue;
 468                if (m > s_m)
 469                        memset(&cb->args[3], 0, sizeof(cb->args) - 3*sizeof(cb->args[0]));
 470
 471                if (dn_hash_dump_zone(skb, cb, tb, dz) < 0) {
 472                        cb->args[2] = m;
 473                        read_unlock(&dn_fib_tables_lock);
 474                        return -1;
 475                }
 476        }
 477        read_unlock(&dn_fib_tables_lock);
 478        cb->args[2] = m;
 479
 480        return skb->len;
 481}
 482
 483int dn_fib_dump(struct sk_buff *skb, struct netlink_callback *cb)
 484{
 485        struct net *net = sock_net(skb->sk);
 486        unsigned int h, s_h;
 487        unsigned int e = 0, s_e;
 488        struct dn_fib_table *tb;
 489        int dumped = 0;
 490
 491        if (!net_eq(net, &init_net))
 492                return 0;
 493
 494        if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
 495                ((struct rtmsg *)nlmsg_data(cb->nlh))->rtm_flags&RTM_F_CLONED)
 496                        return dn_cache_dump(skb, cb);
 497
 498        s_h = cb->args[0];
 499        s_e = cb->args[1];
 500
 501        for (h = s_h; h < DN_FIB_TABLE_HASHSZ; h++, s_h = 0) {
 502                e = 0;
 503                hlist_for_each_entry(tb, &dn_fib_table_hash[h], hlist) {
 504                        if (e < s_e)
 505                                goto next;
 506                        if (dumped)
 507                                memset(&cb->args[2], 0, sizeof(cb->args) -
 508                                                 2 * sizeof(cb->args[0]));
 509                        if (tb->dump(tb, skb, cb) < 0)
 510                                goto out;
 511                        dumped = 1;
 512next:
 513                        e++;
 514                }
 515        }
 516out:
 517        cb->args[1] = e;
 518        cb->args[0] = h;
 519
 520        return skb->len;
 521}
 522
 523static int dn_fib_table_insert(struct dn_fib_table *tb, struct rtmsg *r, struct nlattr *attrs[],
 524                               struct nlmsghdr *n, struct netlink_skb_parms *req)
 525{
 526        struct dn_hash *table = (struct dn_hash *)tb->data;
 527        struct dn_fib_node *new_f, *f, **fp, **del_fp;
 528        struct dn_zone *dz;
 529        struct dn_fib_info *fi;
 530        int z = r->rtm_dst_len;
 531        int type = r->rtm_type;
 532        dn_fib_key_t key;
 533        int err;
 534
 535        if (z > 16)
 536                return -EINVAL;
 537
 538        dz = table->dh_zones[z];
 539        if (!dz && !(dz = dn_new_zone(table, z)))
 540                return -ENOBUFS;
 541
 542        dz_key_0(key);
 543        if (attrs[RTA_DST]) {
 544                __le16 dst = nla_get_le16(attrs[RTA_DST]);
 545                if (dst & ~DZ_MASK(dz))
 546                        return -EINVAL;
 547                key = dz_key(dst, dz);
 548        }
 549
 550        if ((fi = dn_fib_create_info(r, attrs, n, &err)) == NULL)
 551                return err;
 552
 553        if (dz->dz_nent > (dz->dz_divisor << 2) &&
 554                        dz->dz_divisor > DN_MAX_DIVISOR &&
 555                        (z==16 || (1<<z) > dz->dz_divisor))
 556                dn_rehash_zone(dz);
 557
 558        fp = dn_chain_p(key, dz);
 559
 560        DN_FIB_SCAN(f, fp) {
 561                if (dn_key_leq(key, f->fn_key))
 562                        break;
 563        }
 564
 565        del_fp = NULL;
 566
 567        if (f && (f->fn_state & DN_S_ZOMBIE) &&
 568                        dn_key_eq(f->fn_key, key)) {
 569                del_fp = fp;
 570                fp = &f->fn_next;
 571                f = *fp;
 572                goto create;
 573        }
 574
 575        DN_FIB_SCAN_KEY(f, fp, key) {
 576                if (fi->fib_priority <= DN_FIB_INFO(f)->fib_priority)
 577                        break;
 578        }
 579
 580        if (f && dn_key_eq(f->fn_key, key) &&
 581                        fi->fib_priority == DN_FIB_INFO(f)->fib_priority) {
 582                struct dn_fib_node **ins_fp;
 583
 584                err = -EEXIST;
 585                if (n->nlmsg_flags & NLM_F_EXCL)
 586                        goto out;
 587
 588                if (n->nlmsg_flags & NLM_F_REPLACE) {
 589                        del_fp = fp;
 590                        fp = &f->fn_next;
 591                        f = *fp;
 592                        goto replace;
 593                }
 594
 595                ins_fp = fp;
 596                err = -EEXIST;
 597
 598                DN_FIB_SCAN_KEY(f, fp, key) {
 599                        if (fi->fib_priority != DN_FIB_INFO(f)->fib_priority)
 600                                break;
 601                        if (f->fn_type == type &&
 602                            f->fn_scope == r->rtm_scope &&
 603                            DN_FIB_INFO(f) == fi)
 604                                goto out;
 605                }
 606
 607                if (!(n->nlmsg_flags & NLM_F_APPEND)) {
 608                        fp = ins_fp;
 609                        f = *fp;
 610                }
 611        }
 612
 613create:
 614        err = -ENOENT;
 615        if (!(n->nlmsg_flags & NLM_F_CREATE))
 616                goto out;
 617
 618replace:
 619        err = -ENOBUFS;
 620        new_f = kmem_cache_zalloc(dn_hash_kmem, GFP_KERNEL);
 621        if (new_f == NULL)
 622                goto out;
 623
 624        new_f->fn_key = key;
 625        new_f->fn_type = type;
 626        new_f->fn_scope = r->rtm_scope;
 627        DN_FIB_INFO(new_f) = fi;
 628
 629        new_f->fn_next = f;
 630        write_lock_bh(&dn_fib_tables_lock);
 631        *fp = new_f;
 632        write_unlock_bh(&dn_fib_tables_lock);
 633        dz->dz_nent++;
 634
 635        if (del_fp) {
 636                f = *del_fp;
 637                write_lock_bh(&dn_fib_tables_lock);
 638                *del_fp = f->fn_next;
 639                write_unlock_bh(&dn_fib_tables_lock);
 640
 641                if (!(f->fn_state & DN_S_ZOMBIE))
 642                        dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 643                if (f->fn_state & DN_S_ACCESSED)
 644                        dn_rt_cache_flush(-1);
 645                dn_free_node(f);
 646                dz->dz_nent--;
 647        } else {
 648                dn_rt_cache_flush(-1);
 649        }
 650
 651        dn_rtmsg_fib(RTM_NEWROUTE, new_f, z, tb->n, n, req);
 652
 653        return 0;
 654out:
 655        dn_fib_release_info(fi);
 656        return err;
 657}
 658
 659
 660static int dn_fib_table_delete(struct dn_fib_table *tb, struct rtmsg *r, struct nlattr *attrs[],
 661                               struct nlmsghdr *n, struct netlink_skb_parms *req)
 662{
 663        struct dn_hash *table = (struct dn_hash*)tb->data;
 664        struct dn_fib_node **fp, **del_fp, *f;
 665        int z = r->rtm_dst_len;
 666        struct dn_zone *dz;
 667        dn_fib_key_t key;
 668        int matched;
 669
 670
 671        if (z > 16)
 672                return -EINVAL;
 673
 674        if ((dz = table->dh_zones[z]) == NULL)
 675                return -ESRCH;
 676
 677        dz_key_0(key);
 678        if (attrs[RTA_DST]) {
 679                __le16 dst = nla_get_le16(attrs[RTA_DST]);
 680                if (dst & ~DZ_MASK(dz))
 681                        return -EINVAL;
 682                key = dz_key(dst, dz);
 683        }
 684
 685        fp = dn_chain_p(key, dz);
 686
 687        DN_FIB_SCAN(f, fp) {
 688                if (dn_key_eq(f->fn_key, key))
 689                        break;
 690                if (dn_key_leq(key, f->fn_key))
 691                        return -ESRCH;
 692        }
 693
 694        matched = 0;
 695        del_fp = NULL;
 696        DN_FIB_SCAN_KEY(f, fp, key) {
 697                struct dn_fib_info *fi = DN_FIB_INFO(f);
 698
 699                if (f->fn_state & DN_S_ZOMBIE)
 700                        return -ESRCH;
 701
 702                matched++;
 703
 704                if (del_fp == NULL &&
 705                                (!r->rtm_type || f->fn_type == r->rtm_type) &&
 706                                (r->rtm_scope == RT_SCOPE_NOWHERE || f->fn_scope == r->rtm_scope) &&
 707                                (!r->rtm_protocol ||
 708                                        fi->fib_protocol == r->rtm_protocol) &&
 709                                dn_fib_nh_match(r, n, attrs, fi) == 0)
 710                        del_fp = fp;
 711        }
 712
 713        if (del_fp) {
 714                f = *del_fp;
 715                dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 716
 717                if (matched != 1) {
 718                        write_lock_bh(&dn_fib_tables_lock);
 719                        *del_fp = f->fn_next;
 720                        write_unlock_bh(&dn_fib_tables_lock);
 721
 722                        if (f->fn_state & DN_S_ACCESSED)
 723                                dn_rt_cache_flush(-1);
 724                        dn_free_node(f);
 725                        dz->dz_nent--;
 726                } else {
 727                        f->fn_state |= DN_S_ZOMBIE;
 728                        if (f->fn_state & DN_S_ACCESSED) {
 729                                f->fn_state &= ~DN_S_ACCESSED;
 730                                dn_rt_cache_flush(-1);
 731                        }
 732                        if (++dn_fib_hash_zombies > 128)
 733                                dn_fib_flush();
 734                }
 735
 736                return 0;
 737        }
 738
 739        return -ESRCH;
 740}
 741
 742static inline int dn_flush_list(struct dn_fib_node **fp, int z, struct dn_hash *table)
 743{
 744        int found = 0;
 745        struct dn_fib_node *f;
 746
 747        while((f = *fp) != NULL) {
 748                struct dn_fib_info *fi = DN_FIB_INFO(f);
 749
 750                if (fi && ((f->fn_state & DN_S_ZOMBIE) || (fi->fib_flags & RTNH_F_DEAD))) {
 751                        write_lock_bh(&dn_fib_tables_lock);
 752                        *fp = f->fn_next;
 753                        write_unlock_bh(&dn_fib_tables_lock);
 754
 755                        dn_free_node(f);
 756                        found++;
 757                        continue;
 758                }
 759                fp = &f->fn_next;
 760        }
 761
 762        return found;
 763}
 764
 765static int dn_fib_table_flush(struct dn_fib_table *tb)
 766{
 767        struct dn_hash *table = (struct dn_hash *)tb->data;
 768        struct dn_zone *dz;
 769        int found = 0;
 770
 771        dn_fib_hash_zombies = 0;
 772        for(dz = table->dh_zone_list; dz; dz = dz->dz_next) {
 773                int i;
 774                int tmp = 0;
 775                for(i = dz->dz_divisor-1; i >= 0; i--)
 776                        tmp += dn_flush_list(&dz->dz_hash[i], dz->dz_order, table);
 777                dz->dz_nent -= tmp;
 778                found += tmp;
 779        }
 780
 781        return found;
 782}
 783
 784static int dn_fib_table_lookup(struct dn_fib_table *tb, const struct flowidn *flp, struct dn_fib_res *res)
 785{
 786        int err;
 787        struct dn_zone *dz;
 788        struct dn_hash *t = (struct dn_hash *)tb->data;
 789
 790        read_lock(&dn_fib_tables_lock);
 791        for(dz = t->dh_zone_list; dz; dz = dz->dz_next) {
 792                struct dn_fib_node *f;
 793                dn_fib_key_t k = dz_key(flp->daddr, dz);
 794
 795                for(f = dz_chain(k, dz); f; f = f->fn_next) {
 796                        if (!dn_key_eq(k, f->fn_key)) {
 797                                if (dn_key_leq(k, f->fn_key))
 798                                        break;
 799                                else
 800                                        continue;
 801                        }
 802
 803                        f->fn_state |= DN_S_ACCESSED;
 804
 805                        if (f->fn_state&DN_S_ZOMBIE)
 806                                continue;
 807
 808                        if (f->fn_scope < flp->flowidn_scope)
 809                                continue;
 810
 811                        err = dn_fib_semantic_match(f->fn_type, DN_FIB_INFO(f), flp, res);
 812
 813                        if (err == 0) {
 814                                res->type = f->fn_type;
 815                                res->scope = f->fn_scope;
 816                                res->prefixlen = dz->dz_order;
 817                                goto out;
 818                        }
 819                        if (err < 0)
 820                                goto out;
 821                }
 822        }
 823        err = 1;
 824out:
 825        read_unlock(&dn_fib_tables_lock);
 826        return err;
 827}
 828
 829
 830struct dn_fib_table *dn_fib_get_table(u32 n, int create)
 831{
 832        struct dn_fib_table *t;
 833        unsigned int h;
 834
 835        if (n < RT_TABLE_MIN)
 836                return NULL;
 837
 838        if (n > RT_TABLE_MAX)
 839                return NULL;
 840
 841        h = n & (DN_FIB_TABLE_HASHSZ - 1);
 842        rcu_read_lock();
 843        hlist_for_each_entry_rcu(t, &dn_fib_table_hash[h], hlist) {
 844                if (t->n == n) {
 845                        rcu_read_unlock();
 846                        return t;
 847                }
 848        }
 849        rcu_read_unlock();
 850
 851        if (!create)
 852                return NULL;
 853
 854        if (in_interrupt()) {
 855                net_dbg_ratelimited("DECnet: BUG! Attempt to create routing table from interrupt\n");
 856                return NULL;
 857        }
 858
 859        t = kzalloc(sizeof(struct dn_fib_table) + sizeof(struct dn_hash),
 860                    GFP_KERNEL);
 861        if (t == NULL)
 862                return NULL;
 863
 864        t->n = n;
 865        t->insert = dn_fib_table_insert;
 866        t->delete = dn_fib_table_delete;
 867        t->lookup = dn_fib_table_lookup;
 868        t->flush  = dn_fib_table_flush;
 869        t->dump = dn_fib_table_dump;
 870        hlist_add_head_rcu(&t->hlist, &dn_fib_table_hash[h]);
 871
 872        return t;
 873}
 874
 875struct dn_fib_table *dn_fib_empty_table(void)
 876{
 877        u32 id;
 878
 879        for(id = RT_TABLE_MIN; id <= RT_TABLE_MAX; id++)
 880                if (dn_fib_get_table(id, 0) == NULL)
 881                        return dn_fib_get_table(id, 1);
 882        return NULL;
 883}
 884
 885void dn_fib_flush(void)
 886{
 887        int flushed = 0;
 888        struct dn_fib_table *tb;
 889        unsigned int h;
 890
 891        for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
 892                hlist_for_each_entry(tb, &dn_fib_table_hash[h], hlist)
 893                        flushed += tb->flush(tb);
 894        }
 895
 896        if (flushed)
 897                dn_rt_cache_flush(-1);
 898}
 899
 900void __init dn_fib_table_init(void)
 901{
 902        dn_hash_kmem = kmem_cache_create("dn_fib_info_cache",
 903                                        sizeof(struct dn_fib_info),
 904                                        0, SLAB_HWCACHE_ALIGN,
 905                                        NULL);
 906}
 907
 908void __exit dn_fib_table_cleanup(void)
 909{
 910        struct dn_fib_table *t;
 911        struct hlist_node *next;
 912        unsigned int h;
 913
 914        write_lock(&dn_fib_tables_lock);
 915        for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
 916                hlist_for_each_entry_safe(t, next, &dn_fib_table_hash[h],
 917                                          hlist) {
 918                        hlist_del(&t->hlist);
 919                        kfree(t);
 920                }
 921        }
 922        write_unlock(&dn_fib_tables_lock);
 923}
 924