net/decnet/dn_table.c

   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
  43 struct 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
  56 struct 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) \
  74 for( ; ((f) = *(fp)) != NULL; (fp) = &(f)->fn_next)
  75
  76 #define DN_FIB_SCAN_KEY(f, fp, key) \
  77 for( ; ((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
  81 static struct hlist_head dn_fib_table_hash[DN_FIB_TABLE_HASHSZ];
  82 static DEFINE_RWLOCK(dn_fib_tables_lock);
  83
  84 static struct kmem_cache *dn_hash_kmem __read_mostly;
  85 static int dn_fib_hash_zombies;
  86
  87 static 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
  96 static 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
 103 static 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
 108 static 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
 113 static inline int dn_key_eq(dn_fib_key_t a, dn_fib_key_t b)
 114 {
 115         return a.datum == b.datum;
 116 }
 117
 118 static inline int dn_key_leq(dn_fib_key_t a, dn_fib_key_t b)
 119 {
 120         return a.datum <= b.datum;
 121 }
 122
 123 static 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
 143 static 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                 /* fall through */
 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
 180 static 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
 187 static 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
 229 static 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
 274 static 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
 301 static 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                 if (!(mp_head = nla_nest_start(skb, RTA_MULTIPATH)))
 352                         goto errout;
 353
 354                 for_nexthops(fi) {
 355                         if (!(nhp = nla_reserve_nohdr(skb, sizeof(*nhp))))
 356                                 goto errout;
 357
 358                         nhp->rtnh_flags = nh->nh_flags & 0xFF;
 359                         nhp->rtnh_hops = nh->nh_weight - 1;
 360                         nhp->rtnh_ifindex = nh->nh_oif;
 361
 362                         if (nh->nh_gw &&
 363                             nla_put_le16(skb, RTA_GATEWAY, nh->nh_gw) < 0)
 364                                 goto errout;
 365
 366                         nhp->rtnh_len = skb_tail_pointer(skb) - (unsigned char *)nhp;
 367                 } endfor_nexthops(fi);
 368
 369                 nla_nest_end(skb, mp_head);
 370         }
 371
 372         nlmsg_end(skb, nlh);
 373         return 0;
 374
 375 errout:
 376         nlmsg_cancel(skb, nlh);
 377         return -EMSGSIZE;
 378 }
 379
 380
 381 static void dn_rtmsg_fib(int event, struct dn_fib_node *f, int z, u32 tb_id,
 382                         struct nlmsghdr *nlh, struct netlink_skb_parms *req)
 383 {
 384         struct sk_buff *skb;
 385         u32 portid = req ? req->portid : 0;
 386         int err = -ENOBUFS;
 387
 388         skb = nlmsg_new(dn_fib_nlmsg_size(DN_FIB_INFO(f)), GFP_KERNEL);
 389         if (skb == NULL)
 390                 goto errout;
 391
 392         err = dn_fib_dump_info(skb, portid, nlh->nlmsg_seq, event, tb_id,
 393                                f->fn_type, f->fn_scope, &f->fn_key, z,
 394                                DN_FIB_INFO(f), 0);
 395         if (err < 0) {
 396                 /* -EMSGSIZE implies BUG in dn_fib_nlmsg_size() */
 397                 WARN_ON(err == -EMSGSIZE);
 398                 kfree_skb(skb);
 399                 goto errout;
 400         }
 401         rtnl_notify(skb, &init_net, portid, RTNLGRP_DECnet_ROUTE, nlh, GFP_KERNEL);
 402         return;
 403 errout:
 404         if (err < 0)
 405                 rtnl_set_sk_err(&init_net, RTNLGRP_DECnet_ROUTE, err);
 406 }
 407
 408 static __inline__ int dn_hash_dump_bucket(struct sk_buff *skb,
 409                                 struct netlink_callback *cb,
 410                                 struct dn_fib_table *tb,
 411                                 struct dn_zone *dz,
 412                                 struct dn_fib_node *f)
 413 {
 414         int i, s_i;
 415
 416         s_i = cb->args[4];
 417         for(i = 0; f; i++, f = f->fn_next) {
 418                 if (i < s_i)
 419                         continue;
 420                 if (f->fn_state & DN_S_ZOMBIE)
 421                         continue;
 422                 if (dn_fib_dump_info(skb, NETLINK_CB(cb->skb).portid,
 423                                 cb->nlh->nlmsg_seq,
 424                                 RTM_NEWROUTE,
 425                                 tb->n,
 426                                 (f->fn_state & DN_S_ZOMBIE) ? 0 : f->fn_type,
 427                                 f->fn_scope, &f->fn_key, dz->dz_order,
 428                                 f->fn_info, NLM_F_MULTI) < 0) {
 429                         cb->args[4] = i;
 430                         return -1;
 431                 }
 432         }
 433         cb->args[4] = i;
 434         return skb->len;
 435 }
 436
 437 static __inline__ int dn_hash_dump_zone(struct sk_buff *skb,
 438                                 struct netlink_callback *cb,
 439                                 struct dn_fib_table *tb,
 440                                 struct dn_zone *dz)
 441 {
 442         int h, s_h;
 443
 444         s_h = cb->args[3];
 445         for(h = 0; h < dz->dz_divisor; h++) {
 446                 if (h < s_h)
 447                         continue;
 448                 if (h > s_h)
 449                         memset(&cb->args[4], 0, sizeof(cb->args) - 4*sizeof(cb->args[0]));
 450                 if (dz->dz_hash == NULL || dz->dz_hash[h] == NULL)
 451                         continue;
 452                 if (dn_hash_dump_bucket(skb, cb, tb, dz, dz->dz_hash[h]) < 0) {
 453                         cb->args[3] = h;
 454                         return -1;
 455                 }
 456         }
 457         cb->args[3] = h;
 458         return skb->len;
 459 }
 460
 461 static int dn_fib_table_dump(struct dn_fib_table *tb, struct sk_buff *skb,
 462                                 struct netlink_callback *cb)
 463 {
 464         int m, s_m;
 465         struct dn_zone *dz;
 466         struct dn_hash *table = (struct dn_hash *)tb->data;
 467
 468         s_m = cb->args[2];
 469         read_lock(&dn_fib_tables_lock);
 470         for(dz = table->dh_zone_list, m = 0; dz; dz = dz->dz_next, m++) {
 471                 if (m < s_m)
 472                         continue;
 473                 if (m > s_m)
 474                         memset(&cb->args[3], 0, sizeof(cb->args) - 3*sizeof(cb->args[0]));
 475
 476                 if (dn_hash_dump_zone(skb, cb, tb, dz) < 0) {
 477                         cb->args[2] = m;
 478                         read_unlock(&dn_fib_tables_lock);
 479                         return -1;
 480                 }
 481         }
 482         read_unlock(&dn_fib_tables_lock);
 483         cb->args[2] = m;
 484
 485         return skb->len;
 486 }
 487
 488 int dn_fib_dump(struct sk_buff *skb, struct netlink_callback *cb)
 489 {
 490         struct net *net = sock_net(skb->sk);
 491         unsigned int h, s_h;
 492         unsigned int e = 0, s_e;
 493         struct dn_fib_table *tb;
 494         int dumped = 0;
 495
 496         if (!net_eq(net, &init_net))
 497                 return 0;
 498
 499         if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
 500                 ((struct rtmsg *)nlmsg_data(cb->nlh))->rtm_flags&RTM_F_CLONED)
 501                         return dn_cache_dump(skb, cb);
 502
 503         s_h = cb->args[0];
 504         s_e = cb->args[1];
 505
 506         for (h = s_h; h < DN_FIB_TABLE_HASHSZ; h++, s_h = 0) {
 507                 e = 0;
 508                 hlist_for_each_entry(tb, &dn_fib_table_hash[h], hlist) {
 509                         if (e < s_e)
 510                                 goto next;
 511                         if (dumped)
 512                                 memset(&cb->args[2], 0, sizeof(cb->args) -
 513                                                  2 * sizeof(cb->args[0]));
 514                         if (tb->dump(tb, skb, cb) < 0)
 515                                 goto out;
 516                         dumped = 1;
 517 next:
 518                         e++;
 519                 }
 520         }
 521 out:
 522         cb->args[1] = e;
 523         cb->args[0] = h;
 524
 525         return skb->len;
 526 }
 527
 528 static int dn_fib_table_insert(struct dn_fib_table *tb, struct rtmsg *r, struct nlattr *attrs[],
 529                                struct nlmsghdr *n, struct netlink_skb_parms *req)
 530 {
 531         struct dn_hash *table = (struct dn_hash *)tb->data;
 532         struct dn_fib_node *new_f, *f, **fp, **del_fp;
 533         struct dn_zone *dz;
 534         struct dn_fib_info *fi;
 535         int z = r->rtm_dst_len;
 536         int type = r->rtm_type;
 537         dn_fib_key_t key;
 538         int err;
 539
 540         if (z > 16)
 541                 return -EINVAL;
 542
 543         dz = table->dh_zones[z];
 544         if (!dz && !(dz = dn_new_zone(table, z)))
 545                 return -ENOBUFS;
 546
 547         dz_key_0(key);
 548         if (attrs[RTA_DST]) {
 549                 __le16 dst = nla_get_le16(attrs[RTA_DST]);
 550                 if (dst & ~DZ_MASK(dz))
 551                         return -EINVAL;
 552                 key = dz_key(dst, dz);
 553         }
 554
 555         if ((fi = dn_fib_create_info(r, attrs, n, &err)) == NULL)
 556                 return err;
 557
 558         if (dz->dz_nent > (dz->dz_divisor << 2) &&
 559                         dz->dz_divisor > DN_MAX_DIVISOR &&
 560                         (z==16 || (1<<z) > dz->dz_divisor))
 561                 dn_rehash_zone(dz);
 562
 563         fp = dn_chain_p(key, dz);
 564
 565         DN_FIB_SCAN(f, fp) {
 566                 if (dn_key_leq(key, f->fn_key))
 567                         break;
 568         }
 569
 570         del_fp = NULL;
 571
 572         if (f && (f->fn_state & DN_S_ZOMBIE) &&
 573                         dn_key_eq(f->fn_key, key)) {
 574                 del_fp = fp;
 575                 fp = &f->fn_next;
 576                 f = *fp;
 577                 goto create;
 578         }
 579
 580         DN_FIB_SCAN_KEY(f, fp, key) {
 581                 if (fi->fib_priority <= DN_FIB_INFO(f)->fib_priority)
 582                         break;
 583         }
 584
 585         if (f && dn_key_eq(f->fn_key, key) &&
 586                         fi->fib_priority == DN_FIB_INFO(f)->fib_priority) {
 587                 struct dn_fib_node **ins_fp;
 588
 589                 err = -EEXIST;
 590                 if (n->nlmsg_flags & NLM_F_EXCL)
 591                         goto out;
 592
 593                 if (n->nlmsg_flags & NLM_F_REPLACE) {
 594                         del_fp = fp;
 595                         fp = &f->fn_next;
 596                         f = *fp;
 597                         goto replace;
 598                 }
 599
 600                 ins_fp = fp;
 601                 err = -EEXIST;
 602
 603                 DN_FIB_SCAN_KEY(f, fp, key) {
 604                         if (fi->fib_priority != DN_FIB_INFO(f)->fib_priority)
 605                                 break;
 606                         if (f->fn_type == type &&
 607                             f->fn_scope == r->rtm_scope &&
 608                             DN_FIB_INFO(f) == fi)
 609                                 goto out;
 610                 }
 611
 612                 if (!(n->nlmsg_flags & NLM_F_APPEND)) {
 613                         fp = ins_fp;
 614                         f = *fp;
 615                 }
 616         }
 617
 618 create:
 619         err = -ENOENT;
 620         if (!(n->nlmsg_flags & NLM_F_CREATE))
 621                 goto out;
 622
 623 replace:
 624         err = -ENOBUFS;
 625         new_f = kmem_cache_zalloc(dn_hash_kmem, GFP_KERNEL);
 626         if (new_f == NULL)
 627                 goto out;
 628
 629         new_f->fn_key = key;
 630         new_f->fn_type = type;
 631         new_f->fn_scope = r->rtm_scope;
 632         DN_FIB_INFO(new_f) = fi;
 633
 634         new_f->fn_next = f;
 635         write_lock_bh(&dn_fib_tables_lock);
 636         *fp = new_f;
 637         write_unlock_bh(&dn_fib_tables_lock);
 638         dz->dz_nent++;
 639
 640         if (del_fp) {
 641                 f = *del_fp;
 642                 write_lock_bh(&dn_fib_tables_lock);
 643                 *del_fp = f->fn_next;
 644                 write_unlock_bh(&dn_fib_tables_lock);
 645
 646                 if (!(f->fn_state & DN_S_ZOMBIE))
 647                         dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 648                 if (f->fn_state & DN_S_ACCESSED)
 649                         dn_rt_cache_flush(-1);
 650                 dn_free_node(f);
 651                 dz->dz_nent--;
 652         } else {
 653                 dn_rt_cache_flush(-1);
 654         }
 655
 656         dn_rtmsg_fib(RTM_NEWROUTE, new_f, z, tb->n, n, req);
 657
 658         return 0;
 659 out:
 660         dn_fib_release_info(fi);
 661         return err;
 662 }
 663
 664
 665 static int dn_fib_table_delete(struct dn_fib_table *tb, struct rtmsg *r, struct nlattr *attrs[],
 666                                struct nlmsghdr *n, struct netlink_skb_parms *req)
 667 {
 668         struct dn_hash *table = (struct dn_hash*)tb->data;
 669         struct dn_fib_node **fp, **del_fp, *f;
 670         int z = r->rtm_dst_len;
 671         struct dn_zone *dz;
 672         dn_fib_key_t key;
 673         int matched;
 674
 675
 676         if (z > 16)
 677                 return -EINVAL;
 678
 679         if ((dz = table->dh_zones[z]) == NULL)
 680                 return -ESRCH;
 681
 682         dz_key_0(key);
 683         if (attrs[RTA_DST]) {
 684                 __le16 dst = nla_get_le16(attrs[RTA_DST]);
 685                 if (dst & ~DZ_MASK(dz))
 686                         return -EINVAL;
 687                 key = dz_key(dst, dz);
 688         }
 689
 690         fp = dn_chain_p(key, dz);
 691
 692         DN_FIB_SCAN(f, fp) {
 693                 if (dn_key_eq(f->fn_key, key))
 694                         break;
 695                 if (dn_key_leq(key, f->fn_key))
 696                         return -ESRCH;
 697         }
 698
 699         matched = 0;
 700         del_fp = NULL;
 701         DN_FIB_SCAN_KEY(f, fp, key) {
 702                 struct dn_fib_info *fi = DN_FIB_INFO(f);
 703
 704                 if (f->fn_state & DN_S_ZOMBIE)
 705                         return -ESRCH;
 706
 707                 matched++;
 708
 709                 if (del_fp == NULL &&
 710                                 (!r->rtm_type || f->fn_type == r->rtm_type) &&
 711                                 (r->rtm_scope == RT_SCOPE_NOWHERE || f->fn_scope == r->rtm_scope) &&
 712                                 (!r->rtm_protocol ||
 713                                         fi->fib_protocol == r->rtm_protocol) &&
 714                                 dn_fib_nh_match(r, n, attrs, fi) == 0)
 715                         del_fp = fp;
 716         }
 717
 718         if (del_fp) {
 719                 f = *del_fp;
 720                 dn_rtmsg_fib(RTM_DELROUTE, f, z, tb->n, n, req);
 721
 722                 if (matched != 1) {
 723                         write_lock_bh(&dn_fib_tables_lock);
 724                         *del_fp = f->fn_next;
 725                         write_unlock_bh(&dn_fib_tables_lock);
 726
 727                         if (f->fn_state & DN_S_ACCESSED)
 728                                 dn_rt_cache_flush(-1);
 729                         dn_free_node(f);
 730                         dz->dz_nent--;
 731                 } else {
 732                         f->fn_state |= DN_S_ZOMBIE;
 733                         if (f->fn_state & DN_S_ACCESSED) {
 734                                 f->fn_state &= ~DN_S_ACCESSED;
 735                                 dn_rt_cache_flush(-1);
 736                         }
 737                         if (++dn_fib_hash_zombies > 128)
 738                                 dn_fib_flush();
 739                 }
 740
 741                 return 0;
 742         }
 743
 744         return -ESRCH;
 745 }
 746
 747 static inline int dn_flush_list(struct dn_fib_node **fp, int z, struct dn_hash *table)
 748 {
 749         int found = 0;
 750         struct dn_fib_node *f;
 751
 752         while((f = *fp) != NULL) {
 753                 struct dn_fib_info *fi = DN_FIB_INFO(f);
 754
 755                 if (fi && ((f->fn_state & DN_S_ZOMBIE) || (fi->fib_flags & RTNH_F_DEAD))) {
 756                         write_lock_bh(&dn_fib_tables_lock);
 757                         *fp = f->fn_next;
 758                         write_unlock_bh(&dn_fib_tables_lock);
 759
 760                         dn_free_node(f);
 761                         found++;
 762                         continue;
 763                 }
 764                 fp = &f->fn_next;
 765         }
 766
 767         return found;
 768 }
 769
 770 static int dn_fib_table_flush(struct dn_fib_table *tb)
 771 {
 772         struct dn_hash *table = (struct dn_hash *)tb->data;
 773         struct dn_zone *dz;
 774         int found = 0;
 775
 776         dn_fib_hash_zombies = 0;
 777         for(dz = table->dh_zone_list; dz; dz = dz->dz_next) {
 778                 int i;
 779                 int tmp = 0;
 780                 for(i = dz->dz_divisor-1; i >= 0; i--)
 781                         tmp += dn_flush_list(&dz->dz_hash[i], dz->dz_order, table);
 782                 dz->dz_nent -= tmp;
 783                 found += tmp;
 784         }
 785
 786         return found;
 787 }
 788
 789 static int dn_fib_table_lookup(struct dn_fib_table *tb, const struct flowidn *flp, struct dn_fib_res *res)
 790 {
 791         int err;
 792         struct dn_zone *dz;
 793         struct dn_hash *t = (struct dn_hash *)tb->data;
 794
 795         read_lock(&dn_fib_tables_lock);
 796         for(dz = t->dh_zone_list; dz; dz = dz->dz_next) {
 797                 struct dn_fib_node *f;
 798                 dn_fib_key_t k = dz_key(flp->daddr, dz);
 799
 800                 for(f = dz_chain(k, dz); f; f = f->fn_next) {
 801                         if (!dn_key_eq(k, f->fn_key)) {
 802                                 if (dn_key_leq(k, f->fn_key))
 803                                         break;
 804                                 else
 805                                         continue;
 806                         }
 807
 808                         f->fn_state |= DN_S_ACCESSED;
 809
 810                         if (f->fn_state&DN_S_ZOMBIE)
 811                                 continue;
 812
 813                         if (f->fn_scope < flp->flowidn_scope)
 814                                 continue;
 815
 816                         err = dn_fib_semantic_match(f->fn_type, DN_FIB_INFO(f), flp, res);
 817
 818                         if (err == 0) {
 819                                 res->type = f->fn_type;
 820                                 res->scope = f->fn_scope;
 821                                 res->prefixlen = dz->dz_order;
 822                                 goto out;
 823                         }
 824                         if (err < 0)
 825                                 goto out;
 826                 }
 827         }
 828         err = 1;
 829 out:
 830         read_unlock(&dn_fib_tables_lock);
 831         return err;
 832 }
 833
 834
 835 struct dn_fib_table *dn_fib_get_table(u32 n, int create)
 836 {
 837         struct dn_fib_table *t;
 838         unsigned int h;
 839
 840         if (n < RT_TABLE_MIN)
 841                 return NULL;
 842
 843         if (n > RT_TABLE_MAX)
 844                 return NULL;
 845
 846         h = n & (DN_FIB_TABLE_HASHSZ - 1);
 847         rcu_read_lock();
 848         hlist_for_each_entry_rcu(t, &dn_fib_table_hash[h], hlist) {
 849                 if (t->n == n) {
 850                         rcu_read_unlock();
 851                         return t;
 852                 }
 853         }
 854         rcu_read_unlock();
 855
 856         if (!create)
 857                 return NULL;
 858
 859         if (in_interrupt()) {
 860                 net_dbg_ratelimited("DECnet: BUG! Attempt to create routing table from interrupt\n");
 861                 return NULL;
 862         }
 863
 864         t = kzalloc(sizeof(struct dn_fib_table) + sizeof(struct dn_hash),
 865                     GFP_KERNEL);
 866         if (t == NULL)
 867                 return NULL;
 868
 869         t->n = n;
 870         t->insert = dn_fib_table_insert;
 871         t->delete = dn_fib_table_delete;
 872         t->lookup = dn_fib_table_lookup;
 873         t->flush  = dn_fib_table_flush;
 874         t->dump = dn_fib_table_dump;
 875         hlist_add_head_rcu(&t->hlist, &dn_fib_table_hash[h]);
 876
 877         return t;
 878 }
 879
 880 struct dn_fib_table *dn_fib_empty_table(void)
 881 {
 882         u32 id;
 883
 884         for(id = RT_TABLE_MIN; id <= RT_TABLE_MAX; id++)
 885                 if (dn_fib_get_table(id, 0) == NULL)
 886                         return dn_fib_get_table(id, 1);
 887         return NULL;
 888 }
 889
 890 void dn_fib_flush(void)
 891 {
 892         int flushed = 0;
 893         struct dn_fib_table *tb;
 894         unsigned int h;
 895
 896         for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
 897                 hlist_for_each_entry(tb, &dn_fib_table_hash[h], hlist)
 898                         flushed += tb->flush(tb);
 899         }
 900
 901         if (flushed)
 902                 dn_rt_cache_flush(-1);
 903 }
 904
 905 void __init dn_fib_table_init(void)
 906 {
 907         dn_hash_kmem = kmem_cache_create("dn_fib_info_cache",
 908                                         sizeof(struct dn_fib_info),
 909                                         0, SLAB_HWCACHE_ALIGN,
 910                                         NULL);
 911 }
 912
 913 void __exit dn_fib_table_cleanup(void)
 914 {
 915         struct dn_fib_table *t;
 916         struct hlist_node *next;
 917         unsigned int h;
 918
 919         write_lock(&dn_fib_tables_lock);
 920         for (h = 0; h < DN_FIB_TABLE_HASHSZ; h++) {
 921                 hlist_for_each_entry_safe(t, next, &dn_fib_table_hash[h],
 922                                           hlist) {
 923                         hlist_del(&t->hlist);
 924                         kfree(t);
 925                 }
 926         }
 927         write_unlock(&dn_fib_tables_lock);
 928 }