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/netlink.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 <asm/atomic.h>
  29#include <asm/uaccess.h>
  30#include <linux/route.h> /* RTF_xxx */
  31#include <net/neighbour.h>
  32#include <net/netlink.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#define dz_prefix(key,dz)       ((key).datum)
  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        int i;
 128        struct dn_fib_node *f, **fp, *next;
 129
 130        for(i = 0; i < old_divisor; i++) {
 131                for(f = old_ht[i]; f; f = f->fn_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", 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 dn_kern_rta *rta, struct dn_fib_info *fi)
 228{
 229        struct rtnexthop *nhp;
 230        int nhlen;
 231
 232        if (rta->rta_priority && *rta->rta_priority != fi->fib_priority)
 233                return 1;
 234
 235        if (rta->rta_oif || rta->rta_gw) {
 236                if ((!rta->rta_oif || *rta->rta_oif == fi->fib_nh->nh_oif) &&
 237                    (!rta->rta_gw  || memcmp(rta->rta_gw, &fi->fib_nh->nh_gw, 2) == 0))
 238                        return 0;
 239                return 1;
 240        }
 241
 242        if (rta->rta_mp == NULL)
 243                return 0;
 244
 245        nhp = RTA_DATA(rta->rta_mp);
 246        nhlen = RTA_PAYLOAD(rta->rta_mp);
 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                        gw = dn_fib_get_attr16(RTNH_DATA(nhp), attrlen, RTA_GATEWAY);
 258
 259                        if (gw && gw != nh->nh_gw)
 260                                return 1;
 261                }
 262                nhp = RTNH_NEXT(nhp);
 263        } endfor_nexthops(fi);
 264
 265        return 0;
 266}
 267
 268static inline size_t dn_fib_nlmsg_size(struct dn_fib_info *fi)
 269{
 270        size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg))
 271                         + nla_total_size(4) /* RTA_TABLE */
 272                         + nla_total_size(2) /* RTA_DST */
 273                         + nla_total_size(4); /* RTA_PRIORITY */
 274
 275        /* space for nested metrics */
 276        payload += nla_total_size((RTAX_MAX * nla_total_size(4)));
 277
 278        if (fi->fib_nhs) {
 279                /* Also handles the special case fib_nhs == 1 */
 280
 281                /* each nexthop is packed in an attribute */
 282                size_t nhsize = nla_total_size(sizeof(struct rtnexthop));
 283
 284                /* may contain a gateway attribute */
 285                nhsize += nla_total_size(4);
 286
 287                /* all nexthops are packed in a nested attribute */
 288                payload += nla_total_size(fi->fib_nhs * nhsize);
 289        }
 290
 291        return payload;
 292}
 293
 294static int dn_fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
 295                        u32 tb_id, u8 type, u8 scope, void *dst, int dst_len,
 296                        struct dn_fib_info *fi, unsigned int flags)
 297{
 298        struct rtmsg *rtm;
 299        struct nlmsghdr *nlh;
 300        unsigned char *b = skb_tail_pointer(skb);
 301
 302        nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*rtm), flags);
 303        rtm = NLMSG_DATA(nlh);
 304        rtm->rtm_family = AF_DECnet;
 305        rtm->rtm_dst_len = dst_len;
 306        rtm->rtm_src_len = 0;
 307        rtm->rtm_tos = 0;
 308        rtm->rtm_table = tb_id;
 309        RTA_PUT_U32(skb, RTA_TABLE, tb_id);
 310        rtm->rtm_flags = fi->fib_flags;
 311        rtm->rtm_scope = scope;
 312        rtm->rtm_type  = type;
 313        if (rtm->rtm_dst_len)
 314                RTA_PUT(skb, RTA_DST, 2, dst);
 315        rtm->rtm_protocol = fi->fib_protocol;
 316        if (fi->fib_priority)
 317                RTA_PUT(skb, RTA_PRIORITY, 4, &fi->fib_priority);
 318        if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0)
 319                goto rtattr_failure;
 320        if (fi->fib_nhs == 1) {
 321                if (fi->fib_nh->nh_gw)
 322                        RTA_PUT(skb, RTA_GATEWAY, 2, &fi->fib_nh->nh_gw);
 323                if (fi->fib_nh->nh_oif)
 324                        RTA_PUT(skb, RTA_OIF, sizeof(int), &fi->fib_nh->nh_oif);
 325        }
 326        if (fi->fib_nhs > 1) {
 327                struct rtnexthop *nhp;
 328                struct rtattr *mp_head;
 329                if (skb_tailroom(skb) <= RTA_SPACE(0))
 330                        goto rtattr_failure;
 331                mp_head = (struct rtattr *)skb_put(skb, RTA_SPACE(0));
 332
 333                for_nexthops(fi) {
 334                        if (skb_tailroom(skb) < RTA_ALIGN(RTA_ALIGN(sizeof(*nhp)) + 4))
 335                                goto rtattr_failure;
 336                        nhp = (struct rtnexthop *)skb_put(skb, RTA_ALIGN(sizeof(*nhp)));
 337                        nhp->rtnh_flags = nh->nh_flags & 0xFF;
 338                        nhp->rtnh_hops = nh->nh_weight - 1;
 339                        nhp->rtnh_ifindex = nh->nh_oif;
 340                        if (nh->nh_gw)
 341                                RTA_PUT(skb, RTA_GATEWAY, 2, &nh->nh_gw);
 342                        nhp->rtnh_len = skb_tail_pointer(skb) - (unsigned char *)nhp;
 343                } endfor_nexthops(fi);
 344                mp_head->rta_type = RTA_MULTIPATH;
 345                mp_head->rta_len = skb_tail_pointer(skb) - (u8 *)mp_head;
 346        }
 347
 348        nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 349        return skb->len;
 350
 351
 352nlmsg_failure:
 353rtattr_failure:
 354        nlmsg_trim(skb, b);
 355        return -EMSGSIZE;
 356}
 357
 358
 359static void dn_rtmsg_fib(int event, struct dn_fib_node *f, int z, u32 tb_id,
 360                        struct nlmsghdr *nlh, struct netlink_skb_parms *req)
 361{
 362        struct sk_buff *skb;
 363        u32 pid = req ? req->pid : 0;
 364        int err = -ENOBUFS;
 365
 366        skb = nlmsg_new(dn_fib_nlmsg_size(DN_FIB_INFO(f)), GFP_KERNEL);
 367        if (skb == NULL)
 368                goto errout;
 369
 370        err = dn_fib_dump_info(skb, pid, nlh->nlmsg_seq, event, tb_id,
 371                               f->fn_type, f->fn_scope, &f->fn_key, z,
 372                               DN_FIB_INFO(f), 0);
 373        if (err < 0) {
 374                /* -EMSGSIZE implies BUG in dn_fib_nlmsg_size() */
 375                WARN_ON(err == -EMSGSIZE);
 376                kfree_skb(skb);
 377                goto errout;
 378        }
 379        rtnl_notify(skb, &init_net, pid, RTNLGRP_DECnet_ROUTE, nlh, GFP_KERNEL);
 380        return;
 381errout:
 382        if (err < 0)
 383                rtnl_set_sk_err(&init_net, RTNLGRP_DECnet_ROUTE, err);
 384}
 385
 386static __inline__ int dn_hash_dump_bucket(struct sk_buff *skb,
 387                                struct netlink_callback *cb,
 388                                struct dn_fib_table *tb,
 389                                struct dn_zone *dz,
 390                                struct dn_fib_node *f)
 391{
 392        int i, s_i;
 393
 394        s_i = cb->args[4];
 395        for(i = 0; f; i++, f = f->fn_next) {
 396                if (i < s_i)
 397                        continue;
 398                if (f->fn_state & DN_S_ZOMBIE)
 399                        continue;
 400                if (dn_fib_dump_info(skb, NETLINK_CB(cb->skb).pid,
 401                                cb->nlh->nlmsg_seq,
 402                                RTM_NEWROUTE,
 403                                tb->n,
 404                                (f->fn_state & DN_S_ZOMBIE) ? 0 : f->fn_type,
 405                                f->fn_scope, &f->fn_key, dz->dz_order,
 406                                f->fn_info, NLM_F_MULTI) < 0) {
 407                        cb->args[4] = i;
 408                        return -1;
 409                }
 410        }
 411        cb->args[4] = i;
 412        return skb->len;
 413}
 414
 415static __inline__ int dn_hash_dump_zone(struct sk_buff *skb,
 416                                struct netlink_callback *cb,
 417                                struct dn_fib_table *tb,
 418                                struct dn_zone *dz)
 419{
 420        int h, s_h;
 421
 422        s_h = cb->args[3];
 423        for(h = 0; h < dz->dz_divisor; h++) {
 424                if (h < s_h)
 425                        continue;
 426                if (h > s_h)
 427                        memset(&cb->args[4], 0, sizeof(cb->args) - 4*sizeof(cb->args[0]));
 428                if (dz->dz_hash == NULL || dz->dz_hash[h] == NULL)
 429                        continue;
 430                if (dn_hash_dump_bucket(skb, cb, tb, dz, dz->dz_hash[h]) < 0) {
 431                        cb->args[3] = h;
 432                        return -1;
 433                }
 434        }
 435        cb->args[3] = h;
 436        return skb->len;
 437}
 438
 439static int dn_fib_table_dump(struct dn_fib_table *tb, struct sk_buff *skb,
 440                                struct netlink_callback *cb)
 441{
 442        int m, s_m;
 443        struct dn_zone *dz;
 444        struct dn_hash *table = (struct dn_hash *)tb->data;
 445
 446        s_m = cb->args[2];
 447        read_lock(&dn_fib_tables_lock);
 448        for(dz = table->dh_zone_list, m = 0; dz; dz = dz->dz_next, m++) {
 449                if (m < s_m)
 450                        continue;
 451                if (m > s_m)
 452                        memset(&cb->args[3], 0, sizeof(cb->args) - 3*sizeof(cb->args[0]));
 453
 454                if (dn_hash_dump_zone(skb, cb, tb, dz) < 0) {
 455                        cb->args[2] = m;
 456                        read_unlock(&dn_fib_tables_lock);
 457                        return -1;
 458                }
 459        }
 460        read_unlock(&dn_fib_tables_lock);
 461        cb->args[2] = m;
 462
 463        return skb->len;
 464}
 465
 466int dn_fib_dump(struct sk_buff *skb, struct netlink_callback *cb)
 467{
 468        struct net *net = sock_net(skb->sk);
 469        unsigned int h, s_h;
 470        unsigned int e = 0, s_e;
 471        struct dn_fib_table *tb;
 472        struct hlist_node *node;
 473        int dumped = 0;
 474
 475        if (!net_eq(net, &init_net))
 476                return 0;
 477
 478        if (NLMSG_PAYLOAD(cb->nlh, 0) >= sizeof(struct rtmsg) &&
 479                ((struct rtmsg *)NLMSG_DATA(cb->nlh))->rtm_flags&RTM_F_CLONED)
 480                        return dn_cache_dump(skb, cb);
 481
 482        s_h = cb->args[0];
 483        s_e = cb->args[1];
 484
 485        for (h = s_h; h < DN_FIB_TABLE_HASHSZ; h++, s_h = 0) {
 486                e = 0;
 487                hlist_for_each_entry(tb, node, &dn_fib_table_hash[h], hlist) {
 488                        if (e < s_e)
 489                                goto next;
 490                        if (dumped)
 491                                memset(&cb->args[2], 0, sizeof(cb->args) -
 492                                                 2 * sizeof(cb->args[0]));
 493                        if (tb->dump(tb, skb, cb) < 0)
 494                                goto out;
 495                        dumped = 1;
 496next:
 497                        e++;
 498                }
 499        }
 500out:
 501        cb->args[1] = e;
 502        cb->args[0] = h;
 503
 504        return skb->len;
 505}
 506
 507static int dn_fib_table_insert(struct dn_fib_table *tb, struct rtmsg *r, struct dn_kern_rta *rta, struct nlmsghdr *n, struct netlink_skb_parms *req)
 508{
 509        struct dn_hash *table = (struct dn_hash *)tb->data;
 510        struct dn_fib_node *new_f, *f, **fp, **del_fp;
 511        struct dn_zone *dz;
 512        struct dn_fib_info *fi;
 513        int z = r->rtm_dst_len;
 514        int type = r->rtm_type;
 515        dn_fib_key_t key;
 516        int err;
 517
 518        if (z > 16)
 519                return -EINVAL;
 520
 521        dz = table->dh_zones[z];
 522        if (!dz && !(dz = dn_new_zone(table, z)))
 523                return -ENOBUFS;
 524
 525        dz_key_0(key);
 526        if (rta->rta_dst) {
 527                __le16 dst;
 528                memcpy(&dst, rta->rta_dst, 2);
 529                if (dst & ~DZ_MASK(dz))
 530                        return -EINVAL;
 531                key = dz_key(dst, dz);
 532        }
 533
 534        if ((fi = dn_fib_create_info(r, rta, n, &err)) == NULL)
 535                return err;
 536
 537        if (dz->dz_nent > (dz->dz_divisor << 2) &&
 538                        dz->dz_divisor > DN_MAX_DIVISOR &&
 539                        (z==16 || (1<<z) > dz->dz_divisor))
 540                dn_rehash_zone(dz);
 541
 542        fp = dn_chain_p(key, dz);
 543
 544        DN_FIB_SCAN(f, fp) {
 545                if (dn_key_leq(key, f->fn_key))
 546                        break;
 547        }
 548
 549        del_fp = NULL;
 550
 551        if (f && (f->fn_state & DN_S_ZOMBIE) &&
 552                        dn_key_eq(f->fn_key, key)) {
 553                del_fp = fp;
 554                fp = &f->fn_next;
 555                f = *fp;
 556                goto create;
 557        }
 558
 559        DN_FIB_SCAN_KEY(f, fp, key) {
 560                if (fi->fib_priority <= DN_FIB_INFO(f)->fib_priority)
 561                        break;
 562        }
 563
 564        if (f && dn_key_eq(f->fn_key, key) &&
 565                        fi->fib_priority == DN_FIB_INFO(f)->fib_priority) {
 566                struct dn_fib_node **ins_fp;
 567
 568                err = -EEXIST;
 569                if (n->nlmsg_flags & NLM_F_EXCL)
 570                        goto out;
 571
 572                if (n->nlmsg_flags & NLM_F_REPLACE) {
 573                        del_fp = fp;
 574                        fp = &f->fn_next;
 575                        f = *fp;
 576                        goto replace;
 577                }
 578
 579                ins_fp = fp;
 580                err = -EEXIST;
 581
 582                DN_FIB_SCAN_KEY(f, fp, key) {
 583                        if (fi->fib_priority != DN_FIB_INFO(f)->fib_priority)
 584                                break;
 585                        if (f->fn_type == type &&
 586                            f->fn_scope == r->rtm_scope &&
 587                            DN_FIB_INFO(f) == fi)
 588                                goto out;
 589                }
 590
 591                if (!(n->nlmsg_flags & NLM_F_APPEND)) {
 592                        fp = ins_fp;
 593                        f = *fp;
 594                }
 595        }
 596
 597create:
 598        err = -ENOENT;
 599        if (!(n->nlmsg_flags & NLM_F_CREATE))
 600                goto out;
 601
 602replace:
 603        err = -ENOBUFS;
 604        new_f = kmem_cache_zalloc(dn_hash_kmem, GFP_KERNEL);
 605        if (new_f == NULL)
 606                goto out;
 607
 608        new_f->fn_key = key;
 609        new_f->fn_type = type;
 610        new_f->fn_scope = r->rtm_scope;
 611        DN_FIB_INFO(new_f) = fi;
 612
 613        new_f->fn_next = f;
 614        write_lock_bh(&dn_fib_tables_lock);
 615        *fp = new_f;
 616        write_unlock_bh(&dn_fib_tables_lock);
 617        dz->dz_nent++;
 618
 619        if (del_fp) {
 620                f = *del_fp;
 621                write_lock_bh(&dn_fib_tables_lock);
 622                *del_fp = f->fn_next;
 623                write_unlock_bh(&dn_fib_tables_lock);
 624
 625                if (!(f->fn_state & DN_S_ZOMBIE))
 626                        dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 627                if (f->fn_state & DN_S_ACCESSED)
 628                        dn_rt_cache_flush(-1);
 629                dn_free_node(f);
 630                dz->dz_nent--;
 631        } else {
 632                dn_rt_cache_flush(-1);
 633        }
 634
 635        dn_rtmsg_fib(RTM_NEWROUTE, new_f, z, tb->n, n, req);
 636
 637        return 0;
 638out:
 639        dn_fib_release_info(fi);
 640        return err;
 641}
 642
 643
 644static int dn_fib_table_delete(struct dn_fib_table *tb, struct rtmsg *r, struct dn_kern_rta *rta, struct nlmsghdr *n, struct netlink_skb_parms *req)
 645{
 646        struct dn_hash *table = (struct dn_hash*)tb->data;
 647        struct dn_fib_node **fp, **del_fp, *f;
 648        int z = r->rtm_dst_len;
 649        struct dn_zone *dz;
 650        dn_fib_key_t key;
 651        int matched;
 652
 653
 654        if (z > 16)
 655                return -EINVAL;
 656
 657        if ((dz = table->dh_zones[z]) == NULL)
 658                return -ESRCH;
 659
 660        dz_key_0(key);
 661        if (rta->rta_dst) {
 662                __le16 dst;
 663                memcpy(&dst, rta->rta_dst, 2);
 664                if (dst & ~DZ_MASK(dz))
 665                        return -EINVAL;
 666                key = dz_key(dst, dz);
 667        }
 668
 669        fp = dn_chain_p(key, dz);
 670
 671        DN_FIB_SCAN(f, fp) {
 672                if (dn_key_eq(f->fn_key, key))
 673                        break;
 674                if (dn_key_leq(key, f->fn_key))
 675                        return -ESRCH;
 676        }
 677
 678        matched = 0;
 679        del_fp = NULL;
 680        DN_FIB_SCAN_KEY(f, fp, key) {
 681                struct dn_fib_info *fi = DN_FIB_INFO(f);
 682
 683                if (f->fn_state & DN_S_ZOMBIE)
 684                        return -ESRCH;
 685
 686                matched++;
 687
 688                if (del_fp == NULL &&
 689                                (!r->rtm_type || f->fn_type == r->rtm_type) &&
 690                                (r->rtm_scope == RT_SCOPE_NOWHERE || f->fn_scope == r->rtm_scope) &&
 691                                (!r->rtm_protocol ||
 692                                        fi->fib_protocol == r->rtm_protocol) &&
 693                                dn_fib_nh_match(r, n, rta, fi) == 0)
 694                        del_fp = fp;
 695        }
 696
 697        if (del_fp) {
 698                f = *del_fp;
 699                dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 700
 701                if (matched != 1) {
 702                        write_lock_bh(&dn_fib_tables_lock);
 703                        *del_fp = f->fn_next;
 704                        write_unlock_bh(&dn_fib_tables_lock);
 705
 706                        if (f->fn_state & DN_S_ACCESSED)
 707                                dn_rt_cache_flush(-1);
 708                        dn_free_node(f);
 709                        dz->dz_nent--;
 710                } else {
 711                        f->fn_state |= DN_S_ZOMBIE;
 712                        if (f->fn_state & DN_S_ACCESSED) {
 713                                f->fn_state &= ~DN_S_ACCESSED;
 714                                dn_rt_cache_flush(-1);
 715                        }
 716                        if (++dn_fib_hash_zombies > 128)
 717                                dn_fib_flush();
 718                }
 719
 720                return 0;
 721        }
 722
 723        return -ESRCH;
 724}
 725
 726static inline int dn_flush_list(struct dn_fib_node **fp, int z, struct dn_hash *table)
 727{
 728        int found = 0;
 729        struct dn_fib_node *f;
 730
 731        while((f = *fp) != NULL) {
 732                struct dn_fib_info *fi = DN_FIB_INFO(f);
 733
 734                if (fi && ((f->fn_state & DN_S_ZOMBIE) || (fi->fib_flags & RTNH_F_DEAD))) {
 735                        write_lock_bh(&dn_fib_tables_lock);
 736                        *fp = f->fn_next;
 737                        write_unlock_bh(&dn_fib_tables_lock);
 738
 739                        dn_free_node(f);
 740                        found++;
 741                        continue;
 742                }
 743                fp = &f->fn_next;
 744        }
 745
 746        return found;
 747}
 748
 749static int dn_fib_table_flush(struct dn_fib_table *tb)
 750{
 751        struct dn_hash *table = (struct dn_hash *)tb->data;
 752        struct dn_zone *dz;
 753        int found = 0;
 754
 755        dn_fib_hash_zombies = 0;
 756        for(dz = table->dh_zone_list; dz; dz = dz->dz_next) {
 757                int i;
 758                int tmp = 0;
 759                for(i = dz->dz_divisor-1; i >= 0; i--)
 760                        tmp += dn_flush_list(&dz->dz_hash[i], dz->dz_order, table);
 761                dz->dz_nent -= tmp;
 762                found += tmp;
 763        }
 764
 765        return found;
 766}
 767
 768static int dn_fib_table_lookup(struct dn_fib_table *tb, const struct flowi *flp, struct dn_fib_res *res)
 769{
 770        int err;
 771        struct dn_zone *dz;
 772        struct dn_hash *t = (struct dn_hash *)tb->data;
 773
 774        read_lock(&dn_fib_tables_lock);
 775        for(dz = t->dh_zone_list; dz; dz = dz->dz_next) {
 776                struct dn_fib_node *f;
 777                dn_fib_key_t k = dz_key(flp->fld_dst, dz);
 778
 779                for(f = dz_chain(k, dz); f; f = f->fn_next) {
 780                        if (!dn_key_eq(k, f->fn_key)) {
 781                                if (dn_key_leq(k, f->fn_key))
 782                                        break;
 783                                else
 784                                        continue;
 785                        }
 786
 787                        f->fn_state |= DN_S_ACCESSED;
 788
 789                        if (f->fn_state&DN_S_ZOMBIE)
 790                                continue;
 791
 792                        if (f->fn_scope < flp->fld_scope)
 793                                continue;
 794
 795                        err = dn_fib_semantic_match(f->fn_type, DN_FIB_INFO(f), flp, res);
 796
 797                        if (err == 0) {
 798                                res->type = f->fn_type;
 799                                res->scope = f->fn_scope;
 800                                res->prefixlen = dz->dz_order;
 801                                goto out;
 802                        }
 803                        if (err < 0)
 804                                goto out;
 805                }
 806        }
 807        err = 1;
 808out:
 809        read_unlock(&dn_fib_tables_lock);
 810        return err;
 811}
 812
 813
 814struct dn_fib_table *dn_fib_get_table(u32 n, int create)
 815{
 816        struct dn_fib_table *t;
 817        struct hlist_node *node;
 818        unsigned int h;
 819
 820        if (n < RT_TABLE_MIN)
 821                return NULL;
 822
 823        if (n > RT_TABLE_MAX)
 824                return NULL;
 825
 826        h = n & (DN_FIB_TABLE_HASHSZ - 1);
 827        rcu_read_lock();
 828        hlist_for_each_entry_rcu(t, node, &dn_fib_table_hash[h], hlist) {
 829                if (t->n == n) {
 830                        rcu_read_unlock();
 831                        return t;
 832                }
 833        }
 834        rcu_read_unlock();
 835
 836        if (!create)
 837                return NULL;
 838
 839        if (in_interrupt() && net_ratelimit()) {
 840                printk(KERN_DEBUG "DECnet: BUG! Attempt to create routing table from interrupt\n");
 841                return NULL;
 842        }
 843
 844        t = kzalloc(sizeof(struct dn_fib_table) + sizeof(struct dn_hash),
 845                    GFP_KERNEL);
 846        if (t == NULL)
 847                return NULL;
 848
 849        t->n = n;
 850        t->insert = dn_fib_table_insert;
 851        t->delete = dn_fib_table_delete;
 852        t->lookup = dn_fib_table_lookup;
 853        t->flush  = dn_fib_table_flush;
 854        t->dump = dn_fib_table_dump;
 855        hlist_add_head_rcu(&t->hlist, &dn_fib_table_hash[h]);
 856
 857        return t;
 858}
 859
 860struct dn_fib_table *dn_fib_empty_table(void)
 861{
 862        u32 id;
 863
 864        for(id = RT_TABLE_MIN; id <= RT_TABLE_MAX; id++)
 865                if (dn_fib_get_table(id, 0) == NULL)
 866                        return dn_fib_get_table(id, 1);
 867        return NULL;
 868}
 869
 870void dn_fib_flush(void)
 871{
 872        int flushed = 0;
 873        struct dn_fib_table *tb;
 874        struct hlist_node *node;
 875        unsigned int h;
 876
 877        for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
 878                hlist_for_each_entry(tb, node, &dn_fib_table_hash[h], hlist)
 879                        flushed += tb->flush(tb);
 880        }
 881
 882        if (flushed)
 883                dn_rt_cache_flush(-1);
 884}
 885
 886void __init dn_fib_table_init(void)
 887{
 888        dn_hash_kmem = kmem_cache_create("dn_fib_info_cache",
 889                                        sizeof(struct dn_fib_info),
 890                                        0, SLAB_HWCACHE_ALIGN,
 891                                        NULL);
 892}
 893
 894void __exit dn_fib_table_cleanup(void)
 895{
 896        struct dn_fib_table *t;
 897        struct hlist_node *node, *next;
 898        unsigned int h;
 899
 900        write_lock(&dn_fib_tables_lock);
 901        for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
 902                hlist_for_each_entry_safe(t, node, next, &dn_fib_table_hash[h],
 903                                          hlist) {
 904                        hlist_del(&t->hlist);
 905                        kfree(t);
 906                }
 907        }
 908        write_unlock(&dn_fib_tables_lock);
 909}
 910
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