linux/net/decnet/dn_table.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * DECnet       An implementation of the DECnet protocol suite for the LINUX
   4 *              operating system.  DECnet is implemented using the  BSD Socket
   5 *              interface as the means of communication with the user level.
   6 *
   7 *              DECnet Routing Forwarding Information Base (Routing Tables)
   8 *
   9 * Author:      Steve Whitehouse <SteveW@ACM.org>
  10 *              Mostly copied from the IPv4 routing code
  11 *
  12 *
  13 * Changes:
  14 *
  15 */
  16#include <linux/string.h>
  17#include <linux/net.h>
  18#include <linux/socket.h>
  19#include <linux/slab.h>
  20#include <linux/sockios.h>
  21#include <linux/init.h>
  22#include <linux/skbuff.h>
  23#include <linux/rtnetlink.h>
  24#include <linux/proc_fs.h>
  25#include <linux/netdevice.h>
  26#include <linux/timer.h>
  27#include <linux/spinlock.h>
  28#include <linux/atomic.h>
  29#include <linux/uaccess.h>
  30#include <linux/route.h> /* RTF_xxx */
  31#include <net/neighbour.h>
  32#include <net/netlink.h>
  33#include <net/tcp.h>
  34#include <net/dst.h>
  35#include <net/flow.h>
  36#include <net/fib_rules.h>
  37#include <net/dn.h>
  38#include <net/dn_route.h>
  39#include <net/dn_fib.h>
  40#include <net/dn_neigh.h>
  41#include <net/dn_dev.h>
  42
  43struct dn_zone
  44{
  45        struct dn_zone          *dz_next;
  46        struct dn_fib_node      **dz_hash;
  47        int                     dz_nent;
  48        int                     dz_divisor;
  49        u32                     dz_hashmask;
  50#define DZ_HASHMASK(dz) ((dz)->dz_hashmask)
  51        int                     dz_order;
  52        __le16                  dz_mask;
  53#define DZ_MASK(dz)     ((dz)->dz_mask)
  54};
  55
  56struct dn_hash
  57{
  58        struct dn_zone  *dh_zones[17];
  59        struct dn_zone  *dh_zone_list;
  60};
  61
  62#define dz_key_0(key)           ((key).datum = 0)
  63
  64#define for_nexthops(fi) { int nhsel; const struct dn_fib_nh *nh;\
  65        for(nhsel = 0, nh = (fi)->fib_nh; nhsel < (fi)->fib_nhs; nh++, nhsel++)
  66
  67#define endfor_nexthops(fi) }
  68
  69#define DN_MAX_DIVISOR 1024
  70#define DN_S_ZOMBIE 1
  71#define DN_S_ACCESSED 2
  72
  73#define DN_FIB_SCAN(f, fp) \
  74for( ; ((f) = *(fp)) != NULL; (fp) = &(f)->fn_next)
  75
  76#define DN_FIB_SCAN_KEY(f, fp, key) \
  77for( ; ((f) = *(fp)) != NULL && dn_key_eq((f)->fn_key, (key)); (fp) = &(f)->fn_next)
  78
  79#define RT_TABLE_MIN 1
  80#define DN_FIB_TABLE_HASHSZ 256
  81static struct hlist_head dn_fib_table_hash[DN_FIB_TABLE_HASHSZ];
  82static DEFINE_RWLOCK(dn_fib_tables_lock);
  83
  84static struct kmem_cache *dn_hash_kmem __read_mostly;
  85static int dn_fib_hash_zombies;
  86
  87static inline dn_fib_idx_t dn_hash(dn_fib_key_t key, struct dn_zone *dz)
  88{
  89        u16 h = le16_to_cpu(key.datum)>>(16 - dz->dz_order);
  90        h ^= (h >> 10);
  91        h ^= (h >> 6);
  92        h &= DZ_HASHMASK(dz);
  93        return *(dn_fib_idx_t *)&h;
  94}
  95
  96static inline dn_fib_key_t dz_key(__le16 dst, struct dn_zone *dz)
  97{
  98        dn_fib_key_t k;
  99        k.datum = dst & DZ_MASK(dz);
 100        return k;
 101}
 102
 103static inline struct dn_fib_node **dn_chain_p(dn_fib_key_t key, struct dn_zone *dz)
 104{
 105        return &dz->dz_hash[dn_hash(key, dz).datum];
 106}
 107
 108static inline struct dn_fib_node *dz_chain(dn_fib_key_t key, struct dn_zone *dz)
 109{
 110        return dz->dz_hash[dn_hash(key, dz).datum];
 111}
 112
 113static inline int dn_key_eq(dn_fib_key_t a, dn_fib_key_t b)
 114{
 115        return a.datum == b.datum;
 116}
 117
 118static inline int dn_key_leq(dn_fib_key_t a, dn_fib_key_t b)
 119{
 120        return a.datum <= b.datum;
 121}
 122
 123static inline void dn_rebuild_zone(struct dn_zone *dz,
 124                                   struct dn_fib_node **old_ht,
 125                                   int old_divisor)
 126{
 127        struct dn_fib_node *f, **fp, *next;
 128        int i;
 129
 130        for(i = 0; i < old_divisor; i++) {
 131                for(f = old_ht[i]; f; f = next) {
 132                        next = f->fn_next;
 133                        for(fp = dn_chain_p(f->fn_key, dz);
 134                                *fp && dn_key_leq((*fp)->fn_key, f->fn_key);
 135                                fp = &(*fp)->fn_next)
 136                                /* NOTHING */;
 137                        f->fn_next = *fp;
 138                        *fp = f;
 139                }
 140        }
 141}
 142
 143static void dn_rehash_zone(struct dn_zone *dz)
 144{
 145        struct dn_fib_node **ht, **old_ht;
 146        int old_divisor, new_divisor;
 147        u32 new_hashmask;
 148
 149        old_divisor = dz->dz_divisor;
 150
 151        switch (old_divisor) {
 152        case 16:
 153                new_divisor = 256;
 154                new_hashmask = 0xFF;
 155                break;
 156        default:
 157                printk(KERN_DEBUG "DECnet: dn_rehash_zone: BUG! %d\n",
 158                       old_divisor);
 159                fallthrough;
 160        case 256:
 161                new_divisor = 1024;
 162                new_hashmask = 0x3FF;
 163                break;
 164        }
 165
 166        ht = kcalloc(new_divisor, sizeof(struct dn_fib_node*), GFP_KERNEL);
 167        if (ht == NULL)
 168                return;
 169
 170        write_lock_bh(&dn_fib_tables_lock);
 171        old_ht = dz->dz_hash;
 172        dz->dz_hash = ht;
 173        dz->dz_hashmask = new_hashmask;
 174        dz->dz_divisor = new_divisor;
 175        dn_rebuild_zone(dz, old_ht, old_divisor);
 176        write_unlock_bh(&dn_fib_tables_lock);
 177        kfree(old_ht);
 178}
 179
 180static void dn_free_node(struct dn_fib_node *f)
 181{
 182        dn_fib_release_info(DN_FIB_INFO(f));
 183        kmem_cache_free(dn_hash_kmem, f);
 184}
 185
 186
 187static struct dn_zone *dn_new_zone(struct dn_hash *table, int z)
 188{
 189        int i;
 190        struct dn_zone *dz = kzalloc(sizeof(struct dn_zone), GFP_KERNEL);
 191        if (!dz)
 192                return NULL;
 193
 194        if (z) {
 195                dz->dz_divisor = 16;
 196                dz->dz_hashmask = 0x0F;
 197        } else {
 198                dz->dz_divisor = 1;
 199                dz->dz_hashmask = 0;
 200        }
 201
 202        dz->dz_hash = kcalloc(dz->dz_divisor, sizeof(struct dn_fib_node *), GFP_KERNEL);
 203        if (!dz->dz_hash) {
 204                kfree(dz);
 205                return NULL;
 206        }
 207
 208        dz->dz_order = z;
 209        dz->dz_mask = dnet_make_mask(z);
 210
 211        for(i = z + 1; i <= 16; i++)
 212                if (table->dh_zones[i])
 213                        break;
 214
 215        write_lock_bh(&dn_fib_tables_lock);
 216        if (i>16) {
 217                dz->dz_next = table->dh_zone_list;
 218                table->dh_zone_list = dz;
 219        } else {
 220                dz->dz_next = table->dh_zones[i]->dz_next;
 221                table->dh_zones[i]->dz_next = dz;
 222        }
 223        table->dh_zones[z] = dz;
 224        write_unlock_bh(&dn_fib_tables_lock);
 225        return dz;
 226}
 227
 228
 229static int dn_fib_nh_match(struct rtmsg *r, struct nlmsghdr *nlh, struct nlattr *attrs[], struct dn_fib_info *fi)
 230{
 231        struct rtnexthop *nhp;
 232        int nhlen;
 233
 234        if (attrs[RTA_PRIORITY] &&
 235            nla_get_u32(attrs[RTA_PRIORITY]) != fi->fib_priority)
 236                return 1;
 237
 238        if (attrs[RTA_OIF] || attrs[RTA_GATEWAY]) {
 239                if ((!attrs[RTA_OIF] || nla_get_u32(attrs[RTA_OIF]) == fi->fib_nh->nh_oif) &&
 240                    (!attrs[RTA_GATEWAY]  || nla_get_le16(attrs[RTA_GATEWAY]) != fi->fib_nh->nh_gw))
 241                        return 0;
 242                return 1;
 243        }
 244
 245        if (!attrs[RTA_MULTIPATH])
 246                return 0;
 247
 248        nhp = nla_data(attrs[RTA_MULTIPATH]);
 249        nhlen = nla_len(attrs[RTA_MULTIPATH]);
 250
 251        for_nexthops(fi) {
 252                int attrlen = nhlen - sizeof(struct rtnexthop);
 253                __le16 gw;
 254
 255                if (attrlen < 0 || (nhlen -= nhp->rtnh_len) < 0)
 256                        return -EINVAL;
 257                if (nhp->rtnh_ifindex && nhp->rtnh_ifindex != nh->nh_oif)
 258                        return 1;
 259                if (attrlen) {
 260                        struct nlattr *gw_attr;
 261
 262                        gw_attr = nla_find((struct nlattr *) (nhp + 1), attrlen, RTA_GATEWAY);
 263                        gw = gw_attr ? nla_get_le16(gw_attr) : 0;
 264
 265                        if (gw && gw != nh->nh_gw)
 266                                return 1;
 267                }
 268                nhp = RTNH_NEXT(nhp);
 269        } endfor_nexthops(fi);
 270
 271        return 0;
 272}
 273
 274static inline size_t dn_fib_nlmsg_size(struct dn_fib_info *fi)
 275{
 276        size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg))
 277                         + nla_total_size(4) /* RTA_TABLE */
 278                         + nla_total_size(2) /* RTA_DST */
 279                         + nla_total_size(4) /* RTA_PRIORITY */
 280                         + nla_total_size(TCP_CA_NAME_MAX); /* RTAX_CC_ALGO */
 281
 282        /* space for nested metrics */
 283        payload += nla_total_size((RTAX_MAX * nla_total_size(4)));
 284
 285        if (fi->fib_nhs) {
 286                /* Also handles the special case fib_nhs == 1 */
 287
 288                /* each nexthop is packed in an attribute */
 289                size_t nhsize = nla_total_size(sizeof(struct rtnexthop));
 290
 291                /* may contain a gateway attribute */
 292                nhsize += nla_total_size(4);
 293
 294                /* all nexthops are packed in a nested attribute */
 295                payload += nla_total_size(fi->fib_nhs * nhsize);
 296        }
 297
 298        return payload;
 299}
 300
 301static int dn_fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event,
 302                        u32 tb_id, u8 type, u8 scope, void *dst, int dst_len,
 303                        struct dn_fib_info *fi, unsigned int flags)
 304{
 305        struct rtmsg *rtm;
 306        struct nlmsghdr *nlh;
 307
 308        nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags);
 309        if (!nlh)
 310                return -EMSGSIZE;
 311
 312        rtm = nlmsg_data(nlh);
 313        rtm->rtm_family = AF_DECnet;
 314        rtm->rtm_dst_len = dst_len;
 315        rtm->rtm_src_len = 0;
 316        rtm->rtm_tos = 0;
 317        rtm->rtm_table = tb_id;
 318        rtm->rtm_flags = fi->fib_flags;
 319        rtm->rtm_scope = scope;
 320        rtm->rtm_type  = type;
 321        rtm->rtm_protocol = fi->fib_protocol;
 322
 323        if (nla_put_u32(skb, RTA_TABLE, tb_id) < 0)
 324                goto errout;
 325
 326        if (rtm->rtm_dst_len &&
 327            nla_put(skb, RTA_DST, 2, dst) < 0)
 328                goto errout;
 329
 330        if (fi->fib_priority &&
 331            nla_put_u32(skb, RTA_PRIORITY, fi->fib_priority) < 0)
 332                goto errout;
 333
 334        if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0)
 335                goto errout;
 336
 337        if (fi->fib_nhs == 1) {
 338                if (fi->fib_nh->nh_gw &&
 339                    nla_put_le16(skb, RTA_GATEWAY, fi->fib_nh->nh_gw) < 0)
 340                        goto errout;
 341
 342                if (fi->fib_nh->nh_oif &&
 343                    nla_put_u32(skb, RTA_OIF, fi->fib_nh->nh_oif) < 0)
 344                        goto errout;
 345        }
 346
 347        if (fi->fib_nhs > 1) {
 348                struct rtnexthop *nhp;
 349                struct nlattr *mp_head;
 350
 351                mp_head = nla_nest_start_noflag(skb, RTA_MULTIPATH);
 352                if (!mp_head)
 353                        goto errout;
 354
 355                for_nexthops(fi) {
 356                        if (!(nhp = nla_reserve_nohdr(skb, sizeof(*nhp))))
 357                                goto errout;
 358
 359                        nhp->rtnh_flags = nh->nh_flags & 0xFF;
 360                        nhp->rtnh_hops = nh->nh_weight - 1;
 361                        nhp->rtnh_ifindex = nh->nh_oif;
 362
 363                        if (nh->nh_gw &&
 364                            nla_put_le16(skb, RTA_GATEWAY, nh->nh_gw) < 0)
 365                                goto errout;
 366
 367                        nhp->rtnh_len = skb_tail_pointer(skb) - (unsigned char *)nhp;
 368                } endfor_nexthops(fi);
 369
 370                nla_nest_end(skb, mp_head);
 371        }
 372
 373        nlmsg_end(skb, nlh);
 374        return 0;
 375
 376errout:
 377        nlmsg_cancel(skb, nlh);
 378        return -EMSGSIZE;
 379}
 380
 381
 382static void dn_rtmsg_fib(int event, struct dn_fib_node *f, int z, u32 tb_id,
 383                        struct nlmsghdr *nlh, struct netlink_skb_parms *req)
 384{
 385        struct sk_buff *skb;
 386        u32 portid = req ? req->portid : 0;
 387        int err = -ENOBUFS;
 388
 389        skb = nlmsg_new(dn_fib_nlmsg_size(DN_FIB_INFO(f)), GFP_KERNEL);
 390        if (skb == NULL)
 391                goto errout;
 392
 393        err = dn_fib_dump_info(skb, portid, nlh->nlmsg_seq, event, tb_id,
 394                               f->fn_type, f->fn_scope, &f->fn_key, z,
 395                               DN_FIB_INFO(f), 0);
 396        if (err < 0) {
 397                /* -EMSGSIZE implies BUG in dn_fib_nlmsg_size() */
 398                WARN_ON(err == -EMSGSIZE);
 399                kfree_skb(skb);
 400                goto errout;
 401        }
 402        rtnl_notify(skb, &init_net, portid, RTNLGRP_DECnet_ROUTE, nlh, GFP_KERNEL);
 403        return;
 404errout:
 405        if (err < 0)
 406                rtnl_set_sk_err(&init_net, RTNLGRP_DECnet_ROUTE, err);
 407}
 408
 409static __inline__ int dn_hash_dump_bucket(struct sk_buff *skb,
 410                                struct netlink_callback *cb,
 411                                struct dn_fib_table *tb,
 412                                struct dn_zone *dz,
 413                                struct dn_fib_node *f)
 414{
 415        int i, s_i;
 416
 417        s_i = cb->args[4];
 418        for(i = 0; f; i++, f = f->fn_next) {
 419                if (i < s_i)
 420                        continue;
 421                if (f->fn_state & DN_S_ZOMBIE)
 422                        continue;
 423                if (dn_fib_dump_info(skb, NETLINK_CB(cb->skb).portid,
 424                                cb->nlh->nlmsg_seq,
 425                                RTM_NEWROUTE,
 426                                tb->n,
 427                                (f->fn_state & DN_S_ZOMBIE) ? 0 : f->fn_type,
 428                                f->fn_scope, &f->fn_key, dz->dz_order,
 429                                f->fn_info, NLM_F_MULTI) < 0) {
 430                        cb->args[4] = i;
 431                        return -1;
 432                }
 433        }
 434        cb->args[4] = i;
 435        return skb->len;
 436}
 437
 438static __inline__ int dn_hash_dump_zone(struct sk_buff *skb,
 439                                struct netlink_callback *cb,
 440                                struct dn_fib_table *tb,
 441                                struct dn_zone *dz)
 442{
 443        int h, s_h;
 444
 445        s_h = cb->args[3];
 446        for(h = 0; h < dz->dz_divisor; h++) {
 447                if (h < s_h)
 448                        continue;
 449                if (h > s_h)
 450                        memset(&cb->args[4], 0, sizeof(cb->args) - 4*sizeof(cb->args[0]));
 451                if (dz->dz_hash == NULL || dz->dz_hash[h] == NULL)
 452                        continue;
 453                if (dn_hash_dump_bucket(skb, cb, tb, dz, dz->dz_hash[h]) < 0) {
 454                        cb->args[3] = h;
 455                        return -1;
 456                }
 457        }
 458        cb->args[3] = h;
 459        return skb->len;
 460}
 461
 462static int dn_fib_table_dump(struct dn_fib_table *tb, struct sk_buff *skb,
 463                                struct netlink_callback *cb)
 464{
 465        int m, s_m;
 466        struct dn_zone *dz;
 467        struct dn_hash *table = (struct dn_hash *)tb->data;
 468
 469        s_m = cb->args[2];
 470        read_lock(&dn_fib_tables_lock);
 471        for(dz = table->dh_zone_list, m = 0; dz; dz = dz->dz_next, m++) {
 472                if (m < s_m)
 473                        continue;
 474                if (m > s_m)
 475                        memset(&cb->args[3], 0, sizeof(cb->args) - 3*sizeof(cb->args[0]));
 476
 477                if (dn_hash_dump_zone(skb, cb, tb, dz) < 0) {
 478                        cb->args[2] = m;
 479                        read_unlock(&dn_fib_tables_lock);
 480                        return -1;
 481                }
 482        }
 483        read_unlock(&dn_fib_tables_lock);
 484        cb->args[2] = m;
 485
 486        return skb->len;
 487}
 488
 489int dn_fib_dump(struct sk_buff *skb, struct netlink_callback *cb)
 490{
 491        struct net *net = sock_net(skb->sk);
 492        unsigned int h, s_h;
 493        unsigned int e = 0, s_e;
 494        struct dn_fib_table *tb;
 495        int dumped = 0;
 496
 497        if (!net_eq(net, &init_net))
 498                return 0;
 499
 500        if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
 501                ((struct rtmsg *)nlmsg_data(cb->nlh))->rtm_flags&RTM_F_CLONED)
 502                        return dn_cache_dump(skb, cb);
 503
 504        s_h = cb->args[0];
 505        s_e = cb->args[1];
 506
 507        for (h = s_h; h < DN_FIB_TABLE_HASHSZ; h++, s_h = 0) {
 508                e = 0;
 509                hlist_for_each_entry(tb, &dn_fib_table_hash[h], hlist) {
 510                        if (e < s_e)
 511                                goto next;
 512                        if (dumped)
 513                                memset(&cb->args[2], 0, sizeof(cb->args) -
 514                                                 2 * sizeof(cb->args[0]));
 515                        if (tb->dump(tb, skb, cb) < 0)
 516                                goto out;
 517                        dumped = 1;
 518next:
 519                        e++;
 520                }
 521        }
 522out:
 523        cb->args[1] = e;
 524        cb->args[0] = h;
 525
 526        return skb->len;
 527}
 528
 529static int dn_fib_table_insert(struct dn_fib_table *tb, struct rtmsg *r, struct nlattr *attrs[],
 530                               struct nlmsghdr *n, struct netlink_skb_parms *req)
 531{
 532        struct dn_hash *table = (struct dn_hash *)tb->data;
 533        struct dn_fib_node *new_f, *f, **fp, **del_fp;
 534        struct dn_zone *dz;
 535        struct dn_fib_info *fi;
 536        int z = r->rtm_dst_len;
 537        int type = r->rtm_type;
 538        dn_fib_key_t key;
 539        int err;
 540
 541        if (z > 16)
 542                return -EINVAL;
 543
 544        dz = table->dh_zones[z];
 545        if (!dz && !(dz = dn_new_zone(table, z)))
 546                return -ENOBUFS;
 547
 548        dz_key_0(key);
 549        if (attrs[RTA_DST]) {
 550                __le16 dst = nla_get_le16(attrs[RTA_DST]);
 551                if (dst & ~DZ_MASK(dz))
 552                        return -EINVAL;
 553                key = dz_key(dst, dz);
 554        }
 555
 556        if ((fi = dn_fib_create_info(r, attrs, n, &err)) == NULL)
 557                return err;
 558
 559        if (dz->dz_nent > (dz->dz_divisor << 2) &&
 560                        dz->dz_divisor > DN_MAX_DIVISOR &&
 561                        (z==16 || (1<<z) > dz->dz_divisor))
 562                dn_rehash_zone(dz);
 563
 564        fp = dn_chain_p(key, dz);
 565
 566        DN_FIB_SCAN(f, fp) {
 567                if (dn_key_leq(key, f->fn_key))
 568                        break;
 569        }
 570
 571        del_fp = NULL;
 572
 573        if (f && (f->fn_state & DN_S_ZOMBIE) &&
 574                        dn_key_eq(f->fn_key, key)) {
 575                del_fp = fp;
 576                fp = &f->fn_next;
 577                f = *fp;
 578                goto create;
 579        }
 580
 581        DN_FIB_SCAN_KEY(f, fp, key) {
 582                if (fi->fib_priority <= DN_FIB_INFO(f)->fib_priority)
 583                        break;
 584        }
 585
 586        if (f && dn_key_eq(f->fn_key, key) &&
 587                        fi->fib_priority == DN_FIB_INFO(f)->fib_priority) {
 588                struct dn_fib_node **ins_fp;
 589
 590                err = -EEXIST;
 591                if (n->nlmsg_flags & NLM_F_EXCL)
 592                        goto out;
 593
 594                if (n->nlmsg_flags & NLM_F_REPLACE) {
 595                        del_fp = fp;
 596                        fp = &f->fn_next;
 597                        f = *fp;
 598                        goto replace;
 599                }
 600
 601                ins_fp = fp;
 602                err = -EEXIST;
 603
 604                DN_FIB_SCAN_KEY(f, fp, key) {
 605                        if (fi->fib_priority != DN_FIB_INFO(f)->fib_priority)
 606                                break;
 607                        if (f->fn_type == type &&
 608                            f->fn_scope == r->rtm_scope &&
 609                            DN_FIB_INFO(f) == fi)
 610                                goto out;
 611                }
 612
 613                if (!(n->nlmsg_flags & NLM_F_APPEND)) {
 614                        fp = ins_fp;
 615                        f = *fp;
 616                }
 617        }
 618
 619create:
 620        err = -ENOENT;
 621        if (!(n->nlmsg_flags & NLM_F_CREATE))
 622                goto out;
 623
 624replace:
 625        err = -ENOBUFS;
 626        new_f = kmem_cache_zalloc(dn_hash_kmem, GFP_KERNEL);
 627        if (new_f == NULL)
 628                goto out;
 629
 630        new_f->fn_key = key;
 631        new_f->fn_type = type;
 632        new_f->fn_scope = r->rtm_scope;
 633        DN_FIB_INFO(new_f) = fi;
 634
 635        new_f->fn_next = f;
 636        write_lock_bh(&dn_fib_tables_lock);
 637        *fp = new_f;
 638        write_unlock_bh(&dn_fib_tables_lock);
 639        dz->dz_nent++;
 640
 641        if (del_fp) {
 642                f = *del_fp;
 643                write_lock_bh(&dn_fib_tables_lock);
 644                *del_fp = f->fn_next;
 645                write_unlock_bh(&dn_fib_tables_lock);
 646
 647                if (!(f->fn_state & DN_S_ZOMBIE))
 648                        dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 649                if (f->fn_state & DN_S_ACCESSED)
 650                        dn_rt_cache_flush(-1);
 651                dn_free_node(f);
 652                dz->dz_nent--;
 653        } else {
 654                dn_rt_cache_flush(-1);
 655        }
 656
 657        dn_rtmsg_fib(RTM_NEWROUTE, new_f, z, tb->n, n, req);
 658
 659        return 0;
 660out:
 661        dn_fib_release_info(fi);
 662        return err;
 663}
 664
 665
 666static int dn_fib_table_delete(struct dn_fib_table *tb, struct rtmsg *r, struct nlattr *attrs[],
 667                               struct nlmsghdr *n, struct netlink_skb_parms *req)
 668{
 669        struct dn_hash *table = (struct dn_hash*)tb->data;
 670        struct dn_fib_node **fp, **del_fp, *f;
 671        int z = r->rtm_dst_len;
 672        struct dn_zone *dz;
 673        dn_fib_key_t key;
 674        int matched;
 675
 676
 677        if (z > 16)
 678                return -EINVAL;
 679
 680        if ((dz = table->dh_zones[z]) == NULL)
 681                return -ESRCH;
 682
 683        dz_key_0(key);
 684        if (attrs[RTA_DST]) {
 685                __le16 dst = nla_get_le16(attrs[RTA_DST]);
 686                if (dst & ~DZ_MASK(dz))
 687                        return -EINVAL;
 688                key = dz_key(dst, dz);
 689        }
 690
 691        fp = dn_chain_p(key, dz);
 692
 693        DN_FIB_SCAN(f, fp) {
 694                if (dn_key_eq(f->fn_key, key))
 695                        break;
 696                if (dn_key_leq(key, f->fn_key))
 697                        return -ESRCH;
 698        }
 699
 700        matched = 0;
 701        del_fp = NULL;
 702        DN_FIB_SCAN_KEY(f, fp, key) {
 703                struct dn_fib_info *fi = DN_FIB_INFO(f);
 704
 705                if (f->fn_state & DN_S_ZOMBIE)
 706                        return -ESRCH;
 707
 708                matched++;
 709
 710                if (del_fp == NULL &&
 711                                (!r->rtm_type || f->fn_type == r->rtm_type) &&
 712                                (r->rtm_scope == RT_SCOPE_NOWHERE || f->fn_scope == r->rtm_scope) &&
 713                                (!r->rtm_protocol ||
 714                                        fi->fib_protocol == r->rtm_protocol) &&
 715                                dn_fib_nh_match(r, n, attrs, fi) == 0)
 716                        del_fp = fp;
 717        }
 718
 719        if (del_fp) {
 720                f = *del_fp;
 721                dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 722
 723                if (matched != 1) {
 724                        write_lock_bh(&dn_fib_tables_lock);
 725                        *del_fp = f->fn_next;
 726                        write_unlock_bh(&dn_fib_tables_lock);
 727
 728                        if (f->fn_state & DN_S_ACCESSED)
 729                                dn_rt_cache_flush(-1);
 730                        dn_free_node(f);
 731                        dz->dz_nent--;
 732                } else {
 733                        f->fn_state |= DN_S_ZOMBIE;
 734                        if (f->fn_state & DN_S_ACCESSED) {
 735                                f->fn_state &= ~DN_S_ACCESSED;
 736                                dn_rt_cache_flush(-1);
 737                        }
 738                        if (++dn_fib_hash_zombies > 128)
 739                                dn_fib_flush();
 740                }
 741
 742                return 0;
 743        }
 744
 745        return -ESRCH;
 746}
 747
 748static inline int dn_flush_list(struct dn_fib_node **fp, int z, struct dn_hash *table)
 749{
 750        int found = 0;
 751        struct dn_fib_node *f;
 752
 753        while((f = *fp) != NULL) {
 754                struct dn_fib_info *fi = DN_FIB_INFO(f);
 755
 756                if (fi && ((f->fn_state & DN_S_ZOMBIE) || (fi->fib_flags & RTNH_F_DEAD))) {
 757                        write_lock_bh(&dn_fib_tables_lock);
 758                        *fp = f->fn_next;
 759                        write_unlock_bh(&dn_fib_tables_lock);
 760
 761                        dn_free_node(f);
 762                        found++;
 763                        continue;
 764                }
 765                fp = &f->fn_next;
 766        }
 767
 768        return found;
 769}
 770
 771static int dn_fib_table_flush(struct dn_fib_table *tb)
 772{
 773        struct dn_hash *table = (struct dn_hash *)tb->data;
 774        struct dn_zone *dz;
 775        int found = 0;
 776
 777        dn_fib_hash_zombies = 0;
 778        for(dz = table->dh_zone_list; dz; dz = dz->dz_next) {
 779                int i;
 780                int tmp = 0;
 781                for(i = dz->dz_divisor-1; i >= 0; i--)
 782                        tmp += dn_flush_list(&dz->dz_hash[i], dz->dz_order, table);
 783                dz->dz_nent -= tmp;
 784                found += tmp;
 785        }
 786
 787        return found;
 788}
 789
 790static int dn_fib_table_lookup(struct dn_fib_table *tb, const struct flowidn *flp, struct dn_fib_res *res)
 791{
 792        int err;
 793        struct dn_zone *dz;
 794        struct dn_hash *t = (struct dn_hash *)tb->data;
 795
 796        read_lock(&dn_fib_tables_lock);
 797        for(dz = t->dh_zone_list; dz; dz = dz->dz_next) {
 798                struct dn_fib_node *f;
 799                dn_fib_key_t k = dz_key(flp->daddr, dz);
 800
 801                for(f = dz_chain(k, dz); f; f = f->fn_next) {
 802                        if (!dn_key_eq(k, f->fn_key)) {
 803                                if (dn_key_leq(k, f->fn_key))
 804                                        break;
 805                                else
 806                                        continue;
 807                        }
 808
 809                        f->fn_state |= DN_S_ACCESSED;
 810
 811                        if (f->fn_state&DN_S_ZOMBIE)
 812                                continue;
 813
 814                        if (f->fn_scope < flp->flowidn_scope)
 815                                continue;
 816
 817                        err = dn_fib_semantic_match(f->fn_type, DN_FIB_INFO(f), flp, res);
 818
 819                        if (err == 0) {
 820                                res->type = f->fn_type;
 821                                res->scope = f->fn_scope;
 822                                res->prefixlen = dz->dz_order;
 823                                goto out;
 824                        }
 825                        if (err < 0)
 826                                goto out;
 827                }
 828        }
 829        err = 1;
 830out:
 831        read_unlock(&dn_fib_tables_lock);
 832        return err;
 833}
 834
 835
 836struct dn_fib_table *dn_fib_get_table(u32 n, int create)
 837{
 838        struct dn_fib_table *t;
 839        unsigned int h;
 840
 841        if (n < RT_TABLE_MIN)
 842                return NULL;
 843
 844        if (n > RT_TABLE_MAX)
 845                return NULL;
 846
 847        h = n & (DN_FIB_TABLE_HASHSZ - 1);
 848        rcu_read_lock();
 849        hlist_for_each_entry_rcu(t, &dn_fib_table_hash[h], hlist) {
 850                if (t->n == n) {
 851                        rcu_read_unlock();
 852                        return t;
 853                }
 854        }
 855        rcu_read_unlock();
 856
 857        if (!create)
 858                return NULL;
 859
 860        if (in_interrupt()) {
 861                net_dbg_ratelimited("DECnet: BUG! Attempt to create routing table from interrupt\n");
 862                return NULL;
 863        }
 864
 865        t = kzalloc(sizeof(struct dn_fib_table) + sizeof(struct dn_hash),
 866                    GFP_KERNEL);
 867        if (t == NULL)
 868                return NULL;
 869
 870        t->n = n;
 871        t->insert = dn_fib_table_insert;
 872        t->delete = dn_fib_table_delete;
 873        t->lookup = dn_fib_table_lookup;
 874        t->flush  = dn_fib_table_flush;
 875        t->dump = dn_fib_table_dump;
 876        hlist_add_head_rcu(&t->hlist, &dn_fib_table_hash[h]);
 877
 878        return t;
 879}
 880
 881struct dn_fib_table *dn_fib_empty_table(void)
 882{
 883        u32 id;
 884
 885        for(id = RT_TABLE_MIN; id <= RT_TABLE_MAX; id++)
 886                if (dn_fib_get_table(id, 0) == NULL)
 887                        return dn_fib_get_table(id, 1);
 888        return NULL;
 889}
 890
 891void dn_fib_flush(void)
 892{
 893        int flushed = 0;
 894        struct dn_fib_table *tb;
 895        unsigned int h;
 896
 897        for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
 898                hlist_for_each_entry(tb, &dn_fib_table_hash[h], hlist)
 899                        flushed += tb->flush(tb);
 900        }
 901
 902        if (flushed)
 903                dn_rt_cache_flush(-1);
 904}
 905
 906void __init dn_fib_table_init(void)
 907{
 908        dn_hash_kmem = kmem_cache_create("dn_fib_info_cache",
 909                                        sizeof(struct dn_fib_info),
 910                                        0, SLAB_HWCACHE_ALIGN,
 911                                        NULL);
 912}
 913
 914void __exit dn_fib_table_cleanup(void)
 915{
 916        struct dn_fib_table *t;
 917        struct hlist_node *next;
 918        unsigned int h;
 919
 920        write_lock(&dn_fib_tables_lock);
 921        for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
 922                hlist_for_each_entry_safe(t, next, &dn_fib_table_hash[h],
 923                                          hlist) {
 924                        hlist_del(&t->hlist);
 925                        kfree(t);
 926                }
 927        }
 928        write_unlock(&dn_fib_tables_lock);
 929}
 930