net/decnet/dn_route.c

   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 Functions (Endnode and Router)
   7  *
   8  * Authors:     Steve Whitehouse <SteveW@ACM.org>
   9  *              Eduardo Marcelo Serrat <emserrat@geocities.com>
  10  *
  11  * Changes:
  12  *              Steve Whitehouse : Fixes to allow "intra-ethernet" and
  13  *                                 "return-to-sender" bits on outgoing
  14  *                                 packets.
  15  *              Steve Whitehouse : Timeouts for cached routes.
  16  *              Steve Whitehouse : Use dst cache for input routes too.
  17  *              Steve Whitehouse : Fixed error values in dn_send_skb.
  18  *              Steve Whitehouse : Rework routing functions to better fit
  19  *                                 DECnet routing design
  20  *              Alexey Kuznetsov : New SMP locking
  21  *              Steve Whitehouse : More SMP locking changes & dn_cache_dump()
  22  *              Steve Whitehouse : Prerouting NF hook, now really is prerouting.
  23  *                                 Fixed possible skb leak in rtnetlink funcs.
  24  *              Steve Whitehouse : Dave Miller's dynamic hash table sizing and
  25  *                                 Alexey Kuznetsov's finer grained locking
  26  *                                 from ipv4/route.c.
  27  *              Steve Whitehouse : Routing is now starting to look like a
  28  *                                 sensible set of code now, mainly due to
  29  *                                 my copying the IPv4 routing code. The
  30  *                                 hooks here are modified and will continue
  31  *                                 to evolve for a while.
  32  *              Steve Whitehouse : Real SMP at last :-) Also new netfilter
  33  *                                 stuff. Look out raw sockets your days
  34  *                                 are numbered!
  35  *              Steve Whitehouse : Added return-to-sender functions. Added
  36  *                                 backlog congestion level return codes.
  37  *              Steve Whitehouse : Fixed bug where routes were set up with
  38  *                                 no ref count on net devices.
  39  *              Steve Whitehouse : RCU for the route cache
  40  *              Steve Whitehouse : Preparations for the flow cache
  41  *              Steve Whitehouse : Prepare for nonlinear skbs
  42  */
  43
  44 /******************************************************************************
  45     (c) 1995-1998 E.M. Serrat           emserrat@geocities.com
  46
  47     This program is free software; you can redistribute it and/or modify
  48     it under the terms of the GNU General Public License as published by
  49     the Free Software Foundation; either version 2 of the License, or
  50     any later version.
  51
  52     This program is distributed in the hope that it will be useful,
  53     but WITHOUT ANY WARRANTY; without even the implied warranty of
  54     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  55     GNU General Public License for more details.
  56 *******************************************************************************/
  57
  58 #include <linux/errno.h>
  59 #include <linux/types.h>
  60 #include <linux/socket.h>
  61 #include <linux/in.h>
  62 #include <linux/kernel.h>
  63 #include <linux/sockios.h>
  64 #include <linux/net.h>
  65 #include <linux/netdevice.h>
  66 #include <linux/inet.h>
  67 #include <linux/route.h>
  68 #include <linux/in_route.h>
  69 #include <linux/slab.h>
  70 #include <net/sock.h>
  71 #include <linux/mm.h>
  72 #include <linux/proc_fs.h>
  73 #include <linux/seq_file.h>
  74 #include <linux/init.h>
  75 #include <linux/rtnetlink.h>
  76 #include <linux/string.h>
  77 #include <linux/netfilter_decnet.h>
  78 #include <linux/rcupdate.h>
  79 #include <linux/times.h>
  80 #include <linux/export.h>
  81 #include <asm/errno.h>
  82 #include <net/net_namespace.h>
  83 #include <net/netlink.h>
  84 #include <net/neighbour.h>
  85 #include <net/dst.h>
  86 #include <net/flow.h>
  87 #include <net/fib_rules.h>
  88 #include <net/dn.h>
  89 #include <net/dn_dev.h>
  90 #include <net/dn_nsp.h>
  91 #include <net/dn_route.h>
  92 #include <net/dn_neigh.h>
  93 #include <net/dn_fib.h>
  94
  95 struct dn_rt_hash_bucket
  96 {
  97         struct dn_route __rcu *chain;
  98         spinlock_t lock;
  99 };
 100
 101 extern struct neigh_table dn_neigh_table;
 102
 103
 104 static unsigned char dn_hiord_addr[6] = {0xAA,0x00,0x04,0x00,0x00,0x00};
 105
 106 static const int dn_rt_min_delay = 2 * HZ;
 107 static const int dn_rt_max_delay = 10 * HZ;
 108 static const int dn_rt_mtu_expires = 10 * 60 * HZ;
 109
 110 static unsigned long dn_rt_deadline;
 111
 112 static int dn_dst_gc(struct dst_ops *ops);
 113 static struct dst_entry *dn_dst_check(struct dst_entry *, __u32);
 114 static unsigned int dn_dst_default_advmss(const struct dst_entry *dst);
 115 static unsigned int dn_dst_mtu(const struct dst_entry *dst);
 116 static void dn_dst_destroy(struct dst_entry *);
 117 static void dn_dst_ifdown(struct dst_entry *, struct net_device *dev, int how);
 118 static struct dst_entry *dn_dst_negative_advice(struct dst_entry *);
 119 static void dn_dst_link_failure(struct sk_buff *);
 120 static void dn_dst_update_pmtu(struct dst_entry *dst, u32 mtu);
 121 static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst,
 122                                              struct sk_buff *skb,
 123                                              const void *daddr);
 124 static int dn_route_input(struct sk_buff *);
 125 static void dn_run_flush(unsigned long dummy);
 126
 127 static struct dn_rt_hash_bucket *dn_rt_hash_table;
 128 static unsigned int dn_rt_hash_mask;
 129
 130 static struct timer_list dn_route_timer;
 131 static DEFINE_TIMER(dn_rt_flush_timer, dn_run_flush, 0, 0);
 132 int decnet_dst_gc_interval = 2;
 133
 134 static struct dst_ops dn_dst_ops = {
 135         .family =               PF_DECnet,
 136         .protocol =             cpu_to_be16(ETH_P_DNA_RT),
 137         .gc_thresh =            128,
 138         .gc =                   dn_dst_gc,
 139         .check =                dn_dst_check,
 140         .default_advmss =       dn_dst_default_advmss,
 141         .mtu =                  dn_dst_mtu,
 142         .cow_metrics =          dst_cow_metrics_generic,
 143         .destroy =              dn_dst_destroy,
 144         .ifdown =               dn_dst_ifdown,
 145         .negative_advice =      dn_dst_negative_advice,
 146         .link_failure =         dn_dst_link_failure,
 147         .update_pmtu =          dn_dst_update_pmtu,
 148         .neigh_lookup =         dn_dst_neigh_lookup,
 149 };
 150
 151 static void dn_dst_destroy(struct dst_entry *dst)
 152 {
 153         struct dn_route *rt = (struct dn_route *) dst;
 154
 155         if (rt->n)
 156                 neigh_release(rt->n);
 157         dst_destroy_metrics_generic(dst);
 158 }
 159
 160 static void dn_dst_ifdown(struct dst_entry *dst, struct net_device *dev, int how)
 161 {
 162         if (how) {
 163                 struct dn_route *rt = (struct dn_route *) dst;
 164                 struct neighbour *n = rt->n;
 165
 166                 if (n && n->dev == dev) {
 167                         n->dev = dev_net(dev)->loopback_dev;
 168                         dev_hold(n->dev);
 169                         dev_put(dev);
 170                 }
 171         }
 172 }
 173
 174 static __inline__ unsigned int dn_hash(__le16 src, __le16 dst)
 175 {
 176         __u16 tmp = (__u16 __force)(src ^ dst);
 177         tmp ^= (tmp >> 3);
 178         tmp ^= (tmp >> 5);
 179         tmp ^= (tmp >> 10);
 180         return dn_rt_hash_mask & (unsigned int)tmp;
 181 }
 182
 183 static inline void dnrt_free(struct dn_route *rt)
 184 {
 185         call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
 186 }
 187
 188 static inline void dnrt_drop(struct dn_route *rt)
 189 {
 190         dst_release(&rt->dst);
 191         call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
 192 }
 193
 194 static void dn_dst_check_expire(unsigned long dummy)
 195 {
 196         int i;
 197         struct dn_route *rt;
 198         struct dn_route __rcu **rtp;
 199         unsigned long now = jiffies;
 200         unsigned long expire = 120 * HZ;
 201
 202         for (i = 0; i <= dn_rt_hash_mask; i++) {
 203                 rtp = &dn_rt_hash_table[i].chain;
 204
 205                 spin_lock(&dn_rt_hash_table[i].lock);
 206                 while ((rt = rcu_dereference_protected(*rtp,
 207                                                 lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) {
 208                         if (atomic_read(&rt->dst.__refcnt) ||
 209                                         (now - rt->dst.lastuse) < expire) {
 210                                 rtp = &rt->dst.dn_next;
 211                                 continue;
 212                         }
 213                         *rtp = rt->dst.dn_next;
 214                         rt->dst.dn_next = NULL;
 215                         dnrt_free(rt);
 216                 }
 217                 spin_unlock(&dn_rt_hash_table[i].lock);
 218
 219                 if ((jiffies - now) > 0)
 220                         break;
 221         }
 222
 223         mod_timer(&dn_route_timer, now + decnet_dst_gc_interval * HZ);
 224 }
 225
 226 static int dn_dst_gc(struct dst_ops *ops)
 227 {
 228         struct dn_route *rt;
 229         struct dn_route __rcu **rtp;
 230         int i;
 231         unsigned long now = jiffies;
 232         unsigned long expire = 10 * HZ;
 233
 234         for (i = 0; i <= dn_rt_hash_mask; i++) {
 235
 236                 spin_lock_bh(&dn_rt_hash_table[i].lock);
 237                 rtp = &dn_rt_hash_table[i].chain;
 238
 239                 while ((rt = rcu_dereference_protected(*rtp,
 240                                                 lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) {
 241                         if (atomic_read(&rt->dst.__refcnt) ||
 242                                         (now - rt->dst.lastuse) < expire) {
 243                                 rtp = &rt->dst.dn_next;
 244                                 continue;
 245                         }
 246                         *rtp = rt->dst.dn_next;
 247                         rt->dst.dn_next = NULL;
 248                         dnrt_drop(rt);
 249                         break;
 250                 }
 251                 spin_unlock_bh(&dn_rt_hash_table[i].lock);
 252         }
 253
 254         return 0;
 255 }
 256
 257 /*
 258  * The decnet standards don't impose a particular minimum mtu, what they
 259  * do insist on is that the routing layer accepts a datagram of at least
 260  * 230 bytes long. Here we have to subtract the routing header length from
 261  * 230 to get the minimum acceptable mtu. If there is no neighbour, then we
 262  * assume the worst and use a long header size.
 263  *
 264  * We update both the mtu and the advertised mss (i.e. the segment size we
 265  * advertise to the other end).
 266  */
 267 static void dn_dst_update_pmtu(struct dst_entry *dst, u32 mtu)
 268 {
 269         struct dn_route *rt = (struct dn_route *) dst;
 270         struct neighbour *n = rt->n;
 271         u32 min_mtu = 230;
 272         struct dn_dev *dn;
 273
 274         dn = n ? rcu_dereference_raw(n->dev->dn_ptr) : NULL;
 275
 276         if (dn && dn->use_long == 0)
 277                 min_mtu -= 6;
 278         else
 279                 min_mtu -= 21;
 280
 281         if (dst_metric(dst, RTAX_MTU) > mtu && mtu >= min_mtu) {
 282                 if (!(dst_metric_locked(dst, RTAX_MTU))) {
 283                         dst_metric_set(dst, RTAX_MTU, mtu);
 284                         dst_set_expires(dst, dn_rt_mtu_expires);
 285                 }
 286                 if (!(dst_metric_locked(dst, RTAX_ADVMSS))) {
 287                         u32 mss = mtu - DN_MAX_NSP_DATA_HEADER;
 288                         u32 existing_mss = dst_metric_raw(dst, RTAX_ADVMSS);
 289                         if (!existing_mss || existing_mss > mss)
 290                                 dst_metric_set(dst, RTAX_ADVMSS, mss);
 291                 }
 292         }
 293 }
 294
 295 /*
 296  * When a route has been marked obsolete. (e.g. routing cache flush)
 297  */
 298 static struct dst_entry *dn_dst_check(struct dst_entry *dst, __u32 cookie)
 299 {
 300         return NULL;
 301 }
 302
 303 static struct dst_entry *dn_dst_negative_advice(struct dst_entry *dst)
 304 {
 305         dst_release(dst);
 306         return NULL;
 307 }
 308
 309 static void dn_dst_link_failure(struct sk_buff *skb)
 310 {
 311 }
 312
 313 static inline int compare_keys(struct flowidn *fl1, struct flowidn *fl2)
 314 {
 315         return ((fl1->daddr ^ fl2->daddr) |
 316                 (fl1->saddr ^ fl2->saddr) |
 317                 (fl1->flowidn_mark ^ fl2->flowidn_mark) |
 318                 (fl1->flowidn_scope ^ fl2->flowidn_scope) |
 319                 (fl1->flowidn_oif ^ fl2->flowidn_oif) |
 320                 (fl1->flowidn_iif ^ fl2->flowidn_iif)) == 0;
 321 }
 322
 323 static int dn_insert_route(struct dn_route *rt, unsigned int hash, struct dn_route **rp)
 324 {
 325         struct dn_route *rth;
 326         struct dn_route __rcu **rthp;
 327         unsigned long now = jiffies;
 328
 329         rthp = &dn_rt_hash_table[hash].chain;
 330
 331         spin_lock_bh(&dn_rt_hash_table[hash].lock);
 332         while ((rth = rcu_dereference_protected(*rthp,
 333                                                 lockdep_is_held(&dn_rt_hash_table[hash].lock))) != NULL) {
 334                 if (compare_keys(&rth->fld, &rt->fld)) {
 335                         /* Put it first */
 336                         *rthp = rth->dst.dn_next;
 337                         rcu_assign_pointer(rth->dst.dn_next,
 338                                            dn_rt_hash_table[hash].chain);
 339                         rcu_assign_pointer(dn_rt_hash_table[hash].chain, rth);
 340
 341                         dst_use(&rth->dst, now);
 342                         spin_unlock_bh(&dn_rt_hash_table[hash].lock);
 343
 344                         dnrt_drop(rt);
 345                         *rp = rth;
 346                         return 0;
 347                 }
 348                 rthp = &rth->dst.dn_next;
 349         }
 350
 351         rcu_assign_pointer(rt->dst.dn_next, dn_rt_hash_table[hash].chain);
 352         rcu_assign_pointer(dn_rt_hash_table[hash].chain, rt);
 353
 354         dst_use(&rt->dst, now);
 355         spin_unlock_bh(&dn_rt_hash_table[hash].lock);
 356         *rp = rt;
 357         return 0;
 358 }
 359
 360 static void dn_run_flush(unsigned long dummy)
 361 {
 362         int i;
 363         struct dn_route *rt, *next;
 364
 365         for (i = 0; i < dn_rt_hash_mask; i++) {
 366                 spin_lock_bh(&dn_rt_hash_table[i].lock);
 367
 368                 if ((rt = xchg((struct dn_route **)&dn_rt_hash_table[i].chain, NULL)) == NULL)
 369                         goto nothing_to_declare;
 370
 371                 for(; rt; rt = next) {
 372                         next = rcu_dereference_raw(rt->dst.dn_next);
 373                         RCU_INIT_POINTER(rt->dst.dn_next, NULL);
 374                         dst_free((struct dst_entry *)rt);
 375                 }
 376
 377 nothing_to_declare:
 378                 spin_unlock_bh(&dn_rt_hash_table[i].lock);
 379         }
 380 }
 381
 382 static DEFINE_SPINLOCK(dn_rt_flush_lock);
 383
 384 void dn_rt_cache_flush(int delay)
 385 {
 386         unsigned long now = jiffies;
 387         int user_mode = !in_interrupt();
 388
 389         if (delay < 0)
 390                 delay = dn_rt_min_delay;
 391
 392         spin_lock_bh(&dn_rt_flush_lock);
 393
 394         if (del_timer(&dn_rt_flush_timer) && delay > 0 && dn_rt_deadline) {
 395                 long tmo = (long)(dn_rt_deadline - now);
 396
 397                 if (user_mode && tmo < dn_rt_max_delay - dn_rt_min_delay)
 398                         tmo = 0;
 399
 400                 if (delay > tmo)
 401                         delay = tmo;
 402         }
 403
 404         if (delay <= 0) {
 405                 spin_unlock_bh(&dn_rt_flush_lock);
 406                 dn_run_flush(0);
 407                 return;
 408         }
 409
 410         if (dn_rt_deadline == 0)
 411                 dn_rt_deadline = now + dn_rt_max_delay;
 412
 413         dn_rt_flush_timer.expires = now + delay;
 414         add_timer(&dn_rt_flush_timer);
 415         spin_unlock_bh(&dn_rt_flush_lock);
 416 }
 417
 418 /**
 419  * dn_return_short - Return a short packet to its sender
 420  * @skb: The packet to return
 421  *
 422  */
 423 static int dn_return_short(struct sk_buff *skb)
 424 {
 425         struct dn_skb_cb *cb;
 426         unsigned char *ptr;
 427         __le16 *src;
 428         __le16 *dst;
 429
 430         /* Add back headers */
 431         skb_push(skb, skb->data - skb_network_header(skb));
 432
 433         if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
 434                 return NET_RX_DROP;
 435
 436         cb = DN_SKB_CB(skb);
 437         /* Skip packet length and point to flags */
 438         ptr = skb->data + 2;
 439         *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
 440
 441         dst = (__le16 *)ptr;
 442         ptr += 2;
 443         src = (__le16 *)ptr;
 444         ptr += 2;
 445         *ptr = 0; /* Zero hop count */
 446
 447         swap(*src, *dst);
 448
 449         skb->pkt_type = PACKET_OUTGOING;
 450         dn_rt_finish_output(skb, NULL, NULL);
 451         return NET_RX_SUCCESS;
 452 }
 453
 454 /**
 455  * dn_return_long - Return a long packet to its sender
 456  * @skb: The long format packet to return
 457  *
 458  */
 459 static int dn_return_long(struct sk_buff *skb)
 460 {
 461         struct dn_skb_cb *cb;
 462         unsigned char *ptr;
 463         unsigned char *src_addr, *dst_addr;
 464         unsigned char tmp[ETH_ALEN];
 465
 466         /* Add back all headers */
 467         skb_push(skb, skb->data - skb_network_header(skb));
 468
 469         if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
 470                 return NET_RX_DROP;
 471
 472         cb = DN_SKB_CB(skb);
 473         /* Ignore packet length and point to flags */
 474         ptr = skb->data + 2;
 475
 476         /* Skip padding */
 477         if (*ptr & DN_RT_F_PF) {
 478                 char padlen = (*ptr & ~DN_RT_F_PF);
 479                 ptr += padlen;
 480         }
 481
 482         *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
 483         ptr += 2;
 484         dst_addr = ptr;
 485         ptr += 8;
 486         src_addr = ptr;
 487         ptr += 6;
 488         *ptr = 0; /* Zero hop count */
 489
 490         /* Swap source and destination */
 491         memcpy(tmp, src_addr, ETH_ALEN);
 492         memcpy(src_addr, dst_addr, ETH_ALEN);
 493         memcpy(dst_addr, tmp, ETH_ALEN);
 494
 495         skb->pkt_type = PACKET_OUTGOING;
 496         dn_rt_finish_output(skb, dst_addr, src_addr);
 497         return NET_RX_SUCCESS;
 498 }
 499
 500 /**
 501  * dn_route_rx_packet - Try and find a route for an incoming packet
 502  * @skb: The packet to find a route for
 503  *
 504  * Returns: result of input function if route is found, error code otherwise
 505  */
 506 static int dn_route_rx_packet(struct sk_buff *skb)
 507 {
 508         struct dn_skb_cb *cb;
 509         int err;
 510
 511         if ((err = dn_route_input(skb)) == 0)
 512                 return dst_input(skb);
 513
 514         cb = DN_SKB_CB(skb);
 515         if (decnet_debug_level & 4) {
 516                 char *devname = skb->dev ? skb->dev->name : "???";
 517
 518                 printk(KERN_DEBUG
 519                         "DECnet: dn_route_rx_packet: rt_flags=0x%02x dev=%s len=%d src=0x%04hx dst=0x%04hx err=%d type=%d\n",
 520                         (int)cb->rt_flags, devname, skb->len,
 521                         le16_to_cpu(cb->src), le16_to_cpu(cb->dst),
 522                         err, skb->pkt_type);
 523         }
 524
 525         if ((skb->pkt_type == PACKET_HOST) && (cb->rt_flags & DN_RT_F_RQR)) {
 526                 switch (cb->rt_flags & DN_RT_PKT_MSK) {
 527                 case DN_RT_PKT_SHORT:
 528                         return dn_return_short(skb);
 529                 case DN_RT_PKT_LONG:
 530                         return dn_return_long(skb);
 531                 }
 532         }
 533
 534         kfree_skb(skb);
 535         return NET_RX_DROP;
 536 }
 537
 538 static int dn_route_rx_long(struct sk_buff *skb)
 539 {
 540         struct dn_skb_cb *cb = DN_SKB_CB(skb);
 541         unsigned char *ptr = skb->data;
 542
 543         if (!pskb_may_pull(skb, 21)) /* 20 for long header, 1 for shortest nsp */
 544                 goto drop_it;
 545
 546         skb_pull(skb, 20);
 547         skb_reset_transport_header(skb);
 548
 549         /* Destination info */
 550         ptr += 2;
 551         cb->dst = dn_eth2dn(ptr);
 552         if (memcmp(ptr, dn_hiord_addr, 4) != 0)
 553                 goto drop_it;
 554         ptr += 6;
 555
 556
 557         /* Source info */
 558         ptr += 2;
 559         cb->src = dn_eth2dn(ptr);
 560         if (memcmp(ptr, dn_hiord_addr, 4) != 0)
 561                 goto drop_it;
 562         ptr += 6;
 563         /* Other junk */
 564         ptr++;
 565         cb->hops = *ptr++; /* Visit Count */
 566
 567         return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING, skb, skb->dev, NULL,
 568                        dn_route_rx_packet);
 569
 570 drop_it:
 571         kfree_skb(skb);
 572         return NET_RX_DROP;
 573 }
 574
 575
 576
 577 static int dn_route_rx_short(struct sk_buff *skb)
 578 {
 579         struct dn_skb_cb *cb = DN_SKB_CB(skb);
 580         unsigned char *ptr = skb->data;
 581
 582         if (!pskb_may_pull(skb, 6)) /* 5 for short header + 1 for shortest nsp */
 583                 goto drop_it;
 584
 585         skb_pull(skb, 5);
 586         skb_reset_transport_header(skb);
 587
 588         cb->dst = *(__le16 *)ptr;
 589         ptr += 2;
 590         cb->src = *(__le16 *)ptr;
 591         ptr += 2;
 592         cb->hops = *ptr & 0x3f;
 593
 594         return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING, skb, skb->dev, NULL,
 595                        dn_route_rx_packet);
 596
 597 drop_it:
 598         kfree_skb(skb);
 599         return NET_RX_DROP;
 600 }
 601
 602 static int dn_route_discard(struct sk_buff *skb)
 603 {
 604         /*
 605          * I know we drop the packet here, but thats considered success in
 606          * this case
 607          */
 608         kfree_skb(skb);
 609         return NET_RX_SUCCESS;
 610 }
 611
 612 static int dn_route_ptp_hello(struct sk_buff *skb)
 613 {
 614         dn_dev_hello(skb);
 615         dn_neigh_pointopoint_hello(skb);
 616         return NET_RX_SUCCESS;
 617 }
 618
 619 int dn_route_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
 620 {
 621         struct dn_skb_cb *cb;
 622         unsigned char flags = 0;
 623         __u16 len = le16_to_cpu(*(__le16 *)skb->data);
 624         struct dn_dev *dn = rcu_dereference(dev->dn_ptr);
 625         unsigned char padlen = 0;
 626
 627         if (!net_eq(dev_net(dev), &init_net))
 628                 goto dump_it;
 629
 630         if (dn == NULL)
 631                 goto dump_it;
 632
 633         if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
 634                 goto out;
 635
 636         if (!pskb_may_pull(skb, 3))
 637                 goto dump_it;
 638
 639         skb_pull(skb, 2);
 640
 641         if (len > skb->len)
 642                 goto dump_it;
 643
 644         skb_trim(skb, len);
 645
 646         flags = *skb->data;
 647
 648         cb = DN_SKB_CB(skb);
 649         cb->stamp = jiffies;
 650         cb->iif = dev->ifindex;
 651
 652         /*
 653          * If we have padding, remove it.
 654          */
 655         if (flags & DN_RT_F_PF) {
 656                 padlen = flags & ~DN_RT_F_PF;
 657                 if (!pskb_may_pull(skb, padlen + 1))
 658                         goto dump_it;
 659                 skb_pull(skb, padlen);
 660                 flags = *skb->data;
 661         }
 662
 663         skb_reset_network_header(skb);
 664
 665         /*
 666          * Weed out future version DECnet
 667          */
 668         if (flags & DN_RT_F_VER)
 669                 goto dump_it;
 670
 671         cb->rt_flags = flags;
 672
 673         if (decnet_debug_level & 1)
 674                 printk(KERN_DEBUG
 675                         "dn_route_rcv: got 0x%02x from %s [%d %d %d]\n",
 676                         (int)flags, (dev) ? dev->name : "???", len, skb->len,
 677                         padlen);
 678
 679         if (flags & DN_RT_PKT_CNTL) {
 680                 if (unlikely(skb_linearize(skb)))
 681                         goto dump_it;
 682
 683                 switch (flags & DN_RT_CNTL_MSK) {
 684                 case DN_RT_PKT_INIT:
 685                         dn_dev_init_pkt(skb);
 686                         break;
 687                 case DN_RT_PKT_VERI:
 688                         dn_dev_veri_pkt(skb);
 689                         break;
 690                 }
 691
 692                 if (dn->parms.state != DN_DEV_S_RU)
 693                         goto dump_it;
 694
 695                 switch (flags & DN_RT_CNTL_MSK) {
 696                 case DN_RT_PKT_HELO:
 697                         return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
 698                                        skb, skb->dev, NULL,
 699                                        dn_route_ptp_hello);
 700
 701                 case DN_RT_PKT_L1RT:
 702                 case DN_RT_PKT_L2RT:
 703                         return NF_HOOK(NFPROTO_DECNET, NF_DN_ROUTE,
 704                                        skb, skb->dev, NULL,
 705                                        dn_route_discard);
 706                 case DN_RT_PKT_ERTH:
 707                         return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
 708                                        skb, skb->dev, NULL,
 709                                        dn_neigh_router_hello);
 710
 711                 case DN_RT_PKT_EEDH:
 712                         return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
 713                                        skb, skb->dev, NULL,
 714                                        dn_neigh_endnode_hello);
 715                 }
 716         } else {
 717                 if (dn->parms.state != DN_DEV_S_RU)
 718                         goto dump_it;
 719
 720                 skb_pull(skb, 1); /* Pull flags */
 721
 722                 switch (flags & DN_RT_PKT_MSK) {
 723                 case DN_RT_PKT_LONG:
 724                         return dn_route_rx_long(skb);
 725                 case DN_RT_PKT_SHORT:
 726                         return dn_route_rx_short(skb);
 727                 }
 728         }
 729
 730 dump_it:
 731         kfree_skb(skb);
 732 out:
 733         return NET_RX_DROP;
 734 }
 735
 736 static int dn_to_neigh_output(struct sk_buff *skb)
 737 {
 738         struct dst_entry *dst = skb_dst(skb);
 739         struct dn_route *rt = (struct dn_route *) dst;
 740         struct neighbour *n = rt->n;
 741
 742         return n->output(n, skb);
 743 }
 744
 745 static int dn_output(struct sk_buff *skb)
 746 {
 747         struct dst_entry *dst = skb_dst(skb);
 748         struct dn_route *rt = (struct dn_route *)dst;
 749         struct net_device *dev = dst->dev;
 750         struct dn_skb_cb *cb = DN_SKB_CB(skb);
 751
 752         int err = -EINVAL;
 753
 754         if (rt->n == NULL)
 755                 goto error;
 756
 757         skb->dev = dev;
 758
 759         cb->src = rt->rt_saddr;
 760         cb->dst = rt->rt_daddr;
 761
 762         /*
 763          * Always set the Intra-Ethernet bit on all outgoing packets
 764          * originated on this node. Only valid flag from upper layers
 765          * is return-to-sender-requested. Set hop count to 0 too.
 766          */
 767         cb->rt_flags &= ~DN_RT_F_RQR;
 768         cb->rt_flags |= DN_RT_F_IE;
 769         cb->hops = 0;
 770
 771         return NF_HOOK(NFPROTO_DECNET, NF_DN_LOCAL_OUT, skb, NULL, dev,
 772                        dn_to_neigh_output);
 773
 774 error:
 775         net_dbg_ratelimited("dn_output: This should not happen\n");
 776
 777         kfree_skb(skb);
 778
 779         return err;
 780 }
 781
 782 static int dn_forward(struct sk_buff *skb)
 783 {
 784         struct dn_skb_cb *cb = DN_SKB_CB(skb);
 785         struct dst_entry *dst = skb_dst(skb);
 786         struct dn_dev *dn_db = rcu_dereference(dst->dev->dn_ptr);
 787         struct dn_route *rt;
 788         int header_len;
 789 #ifdef CONFIG_NETFILTER
 790         struct net_device *dev = skb->dev;
 791 #endif
 792
 793         if (skb->pkt_type != PACKET_HOST)
 794                 goto drop;
 795
 796         /* Ensure that we have enough space for headers */
 797         rt = (struct dn_route *)skb_dst(skb);
 798         header_len = dn_db->use_long ? 21 : 6;
 799         if (skb_cow(skb, LL_RESERVED_SPACE(rt->dst.dev)+header_len))
 800                 goto drop;
 801
 802         /*
 803          * Hop count exceeded.
 804          */
 805         if (++cb->hops > 30)
 806                 goto drop;
 807
 808         skb->dev = rt->dst.dev;
 809
 810         /*
 811          * If packet goes out same interface it came in on, then set
 812          * the Intra-Ethernet bit. This has no effect for short
 813          * packets, so we don't need to test for them here.
 814          */
 815         cb->rt_flags &= ~DN_RT_F_IE;
 816         if (rt->rt_flags & RTCF_DOREDIRECT)
 817                 cb->rt_flags |= DN_RT_F_IE;
 818
 819         return NF_HOOK(NFPROTO_DECNET, NF_DN_FORWARD, skb, dev, skb->dev,
 820                        dn_to_neigh_output);
 821
 822 drop:
 823         kfree_skb(skb);
 824         return NET_RX_DROP;
 825 }
 826
 827 /*
 828  * Used to catch bugs. This should never normally get
 829  * called.
 830  */
 831 static int dn_rt_bug(struct sk_buff *skb)
 832 {
 833         struct dn_skb_cb *cb = DN_SKB_CB(skb);
 834
 835         net_dbg_ratelimited("dn_rt_bug: skb from:%04x to:%04x\n",
 836                             le16_to_cpu(cb->src), le16_to_cpu(cb->dst));
 837
 838         kfree_skb(skb);
 839
 840         return NET_RX_DROP;
 841 }
 842
 843 static unsigned int dn_dst_default_advmss(const struct dst_entry *dst)
 844 {
 845         return dn_mss_from_pmtu(dst->dev, dst_mtu(dst));
 846 }
 847
 848 static unsigned int dn_dst_mtu(const struct dst_entry *dst)
 849 {
 850         unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
 851
 852         return mtu ? : dst->dev->mtu;
 853 }
 854
 855 static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst,
 856                                              struct sk_buff *skb,
 857                                              const void *daddr)
 858 {
 859         return __neigh_lookup_errno(&dn_neigh_table, daddr, dst->dev);
 860 }
 861
 862 static int dn_rt_set_next_hop(struct dn_route *rt, struct dn_fib_res *res)
 863 {
 864         struct dn_fib_info *fi = res->fi;
 865         struct net_device *dev = rt->dst.dev;
 866         unsigned int mss_metric;
 867         struct neighbour *n;
 868
 869         if (fi) {
 870                 if (DN_FIB_RES_GW(*res) &&
 871                     DN_FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
 872                         rt->rt_gateway = DN_FIB_RES_GW(*res);
 873                 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
 874         }
 875         rt->rt_type = res->type;
 876
 877         if (dev != NULL && rt->n == NULL) {
 878                 n = __neigh_lookup_errno(&dn_neigh_table, &rt->rt_gateway, dev);
 879                 if (IS_ERR(n))
 880                         return PTR_ERR(n);
 881                 rt->n = n;
 882         }
 883
 884         if (dst_metric(&rt->dst, RTAX_MTU) > rt->dst.dev->mtu)
 885                 dst_metric_set(&rt->dst, RTAX_MTU, rt->dst.dev->mtu);
 886         mss_metric = dst_metric_raw(&rt->dst, RTAX_ADVMSS);
 887         if (mss_metric) {
 888                 unsigned int mss = dn_mss_from_pmtu(dev, dst_mtu(&rt->dst));
 889                 if (mss_metric > mss)
 890                         dst_metric_set(&rt->dst, RTAX_ADVMSS, mss);
 891         }
 892         return 0;
 893 }
 894
 895 static inline int dn_match_addr(__le16 addr1, __le16 addr2)
 896 {
 897         __u16 tmp = le16_to_cpu(addr1) ^ le16_to_cpu(addr2);
 898         int match = 16;
 899         while(tmp) {
 900                 tmp >>= 1;
 901                 match--;
 902         }
 903         return match;
 904 }
 905
 906 static __le16 dnet_select_source(const struct net_device *dev, __le16 daddr, int scope)
 907 {
 908         __le16 saddr = 0;
 909         struct dn_dev *dn_db;
 910         struct dn_ifaddr *ifa;
 911         int best_match = 0;
 912         int ret;
 913
 914         rcu_read_lock();
 915         dn_db = rcu_dereference(dev->dn_ptr);
 916         for (ifa = rcu_dereference(dn_db->ifa_list);
 917              ifa != NULL;
 918              ifa = rcu_dereference(ifa->ifa_next)) {
 919                 if (ifa->ifa_scope > scope)
 920                         continue;
 921                 if (!daddr) {
 922                         saddr = ifa->ifa_local;
 923                         break;
 924                 }
 925                 ret = dn_match_addr(daddr, ifa->ifa_local);
 926                 if (ret > best_match)
 927                         saddr = ifa->ifa_local;
 928                 if (best_match == 0)
 929                         saddr = ifa->ifa_local;
 930         }
 931         rcu_read_unlock();
 932
 933         return saddr;
 934 }
 935
 936 static inline __le16 __dn_fib_res_prefsrc(struct dn_fib_res *res)
 937 {
 938         return dnet_select_source(DN_FIB_RES_DEV(*res), DN_FIB_RES_GW(*res), res->scope);
 939 }
 940
 941 static inline __le16 dn_fib_rules_map_destination(__le16 daddr, struct dn_fib_res *res)
 942 {
 943         __le16 mask = dnet_make_mask(res->prefixlen);
 944         return (daddr&~mask)|res->fi->fib_nh->nh_gw;
 945 }
 946
 947 static int dn_route_output_slow(struct dst_entry **pprt, const struct flowidn *oldflp, int try_hard)
 948 {
 949         struct flowidn fld = {
 950                 .daddr = oldflp->daddr,
 951                 .saddr = oldflp->saddr,
 952                 .flowidn_scope = RT_SCOPE_UNIVERSE,
 953                 .flowidn_mark = oldflp->flowidn_mark,
 954                 .flowidn_iif = init_net.loopback_dev->ifindex,
 955                 .flowidn_oif = oldflp->flowidn_oif,
 956         };
 957         struct dn_route *rt = NULL;
 958         struct net_device *dev_out = NULL, *dev;
 959         struct neighbour *neigh = NULL;
 960         unsigned int hash;
 961         unsigned int flags = 0;
 962         struct dn_fib_res res = { .fi = NULL, .type = RTN_UNICAST };
 963         int err;
 964         int free_res = 0;
 965         __le16 gateway = 0;
 966
 967         if (decnet_debug_level & 16)
 968                 printk(KERN_DEBUG
 969                        "dn_route_output_slow: dst=%04x src=%04x mark=%d"
 970                        " iif=%d oif=%d\n", le16_to_cpu(oldflp->daddr),
 971                        le16_to_cpu(oldflp->saddr),
 972                        oldflp->flowidn_mark, init_net.loopback_dev->ifindex,
 973                        oldflp->flowidn_oif);
 974
 975         /* If we have an output interface, verify its a DECnet device */
 976         if (oldflp->flowidn_oif) {
 977                 dev_out = dev_get_by_index(&init_net, oldflp->flowidn_oif);
 978                 err = -ENODEV;
 979                 if (dev_out && dev_out->dn_ptr == NULL) {
 980                         dev_put(dev_out);
 981                         dev_out = NULL;
 982                 }
 983                 if (dev_out == NULL)
 984                         goto out;
 985         }
 986
 987         /* If we have a source address, verify that its a local address */
 988         if (oldflp->saddr) {
 989                 err = -EADDRNOTAVAIL;
 990
 991                 if (dev_out) {
 992                         if (dn_dev_islocal(dev_out, oldflp->saddr))
 993                                 goto source_ok;
 994                         dev_put(dev_out);
 995                         goto out;
 996                 }
 997                 rcu_read_lock();
 998                 for_each_netdev_rcu(&init_net, dev) {
 999                         if (!dev->dn_ptr)
1000                                 continue;
1001                         if (!dn_dev_islocal(dev, oldflp->saddr))
1002                                 continue;
1003                         if ((dev->flags & IFF_LOOPBACK) &&
1004                             oldflp->daddr &&
1005                             !dn_dev_islocal(dev, oldflp->daddr))
1006                                 continue;
1007
1008                         dev_out = dev;
1009                         break;
1010                 }
1011                 rcu_read_unlock();
1012                 if (dev_out == NULL)
1013                         goto out;
1014                 dev_hold(dev_out);
1015 source_ok:
1016                 ;
1017         }
1018
1019         /* No destination? Assume its local */
1020         if (!fld.daddr) {
1021                 fld.daddr = fld.saddr;
1022
1023                 err = -EADDRNOTAVAIL;
1024                 if (dev_out)
1025                         dev_put(dev_out);
1026                 dev_out = init_net.loopback_dev;
1027                 dev_hold(dev_out);
1028                 if (!fld.daddr) {
1029                         fld.daddr =
1030                         fld.saddr = dnet_select_source(dev_out, 0,
1031                                                        RT_SCOPE_HOST);
1032                         if (!fld.daddr)
1033                                 goto out;
1034                 }
1035                 fld.flowidn_oif = init_net.loopback_dev->ifindex;
1036                 res.type = RTN_LOCAL;
1037                 goto make_route;
1038         }
1039
1040         if (decnet_debug_level & 16)
1041                 printk(KERN_DEBUG
1042                        "dn_route_output_slow: initial checks complete."
1043                        " dst=%o4x src=%04x oif=%d try_hard=%d\n",
1044                        le16_to_cpu(fld.daddr), le16_to_cpu(fld.saddr),
1045                        fld.flowidn_oif, try_hard);
1046
1047         /*
1048          * N.B. If the kernel is compiled without router support then
1049          * dn_fib_lookup() will evaluate to non-zero so this if () block
1050          * will always be executed.
1051          */
1052         err = -ESRCH;
1053         if (try_hard || (err = dn_fib_lookup(&fld, &res)) != 0) {
1054                 struct dn_dev *dn_db;
1055                 if (err != -ESRCH)
1056                         goto out;
1057                 /*
1058                  * Here the fallback is basically the standard algorithm for
1059                  * routing in endnodes which is described in the DECnet routing
1060                  * docs
1061                  *
1062                  * If we are not trying hard, look in neighbour cache.
1063                  * The result is tested to ensure that if a specific output
1064                  * device/source address was requested, then we honour that
1065                  * here
1066                  */
1067                 if (!try_hard) {
1068                         neigh = neigh_lookup_nodev(&dn_neigh_table, &init_net, &fld.daddr);
1069                         if (neigh) {
1070                                 if ((oldflp->flowidn_oif &&
1071                                     (neigh->dev->ifindex != oldflp->flowidn_oif)) ||
1072                                     (oldflp->saddr &&
1073                                     (!dn_dev_islocal(neigh->dev,
1074                                                      oldflp->saddr)))) {
1075                                         neigh_release(neigh);
1076                                         neigh = NULL;
1077                                 } else {
1078                                         if (dev_out)
1079                                                 dev_put(dev_out);
1080                                         if (dn_dev_islocal(neigh->dev, fld.daddr)) {
1081                                                 dev_out = init_net.loopback_dev;
1082                                                 res.type = RTN_LOCAL;
1083                                         } else {
1084                                                 dev_out = neigh->dev;
1085                                         }
1086                                         dev_hold(dev_out);
1087                                         goto select_source;
1088                                 }
1089                         }
1090                 }
1091
1092                 /* Not there? Perhaps its a local address */
1093                 if (dev_out == NULL)
1094                         dev_out = dn_dev_get_default();
1095                 err = -ENODEV;
1096                 if (dev_out == NULL)
1097                         goto out;
1098                 dn_db = rcu_dereference_raw(dev_out->dn_ptr);
1099                 /* Possible improvement - check all devices for local addr */
1100                 if (dn_dev_islocal(dev_out, fld.daddr)) {
1101                         dev_put(dev_out);
1102                         dev_out = init_net.loopback_dev;
1103                         dev_hold(dev_out);
1104                         res.type = RTN_LOCAL;
1105                         goto select_source;
1106                 }
1107                 /* Not local either.... try sending it to the default router */
1108                 neigh = neigh_clone(dn_db->router);
1109                 BUG_ON(neigh && neigh->dev != dev_out);
1110
1111                 /* Ok then, we assume its directly connected and move on */
1112 select_source:
1113                 if (neigh)
1114                         gateway = ((struct dn_neigh *)neigh)->addr;
1115                 if (gateway == 0)
1116                         gateway = fld.daddr;
1117                 if (fld.saddr == 0) {
1118                         fld.saddr = dnet_select_source(dev_out, gateway,
1119                                                        res.type == RTN_LOCAL ?
1120                                                        RT_SCOPE_HOST :
1121                                                        RT_SCOPE_LINK);
1122                         if (fld.saddr == 0 && res.type != RTN_LOCAL)
1123                                 goto e_addr;
1124                 }
1125                 fld.flowidn_oif = dev_out->ifindex;
1126                 goto make_route;
1127         }
1128         free_res = 1;
1129
1130         if (res.type == RTN_NAT)
1131                 goto e_inval;
1132
1133         if (res.type == RTN_LOCAL) {
1134                 if (!fld.saddr)
1135                         fld.saddr = fld.daddr;
1136                 if (dev_out)
1137                         dev_put(dev_out);
1138                 dev_out = init_net.loopback_dev;
1139                 dev_hold(dev_out);
1140                 fld.flowidn_oif = dev_out->ifindex;
1141                 if (res.fi)
1142                         dn_fib_info_put(res.fi);
1143                 res.fi = NULL;
1144                 goto make_route;
1145         }
1146
1147         if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1148                 dn_fib_select_multipath(&fld, &res);
1149
1150         /*
1151          * We could add some logic to deal with default routes here and
1152          * get rid of some of the special casing above.
1153          */
1154
1155         if (!fld.saddr)
1156                 fld.saddr = DN_FIB_RES_PREFSRC(res);
1157
1158         if (dev_out)
1159                 dev_put(dev_out);
1160         dev_out = DN_FIB_RES_DEV(res);
1161         dev_hold(dev_out);
1162         fld.flowidn_oif = dev_out->ifindex;
1163         gateway = DN_FIB_RES_GW(res);
1164
1165 make_route:
1166         if (dev_out->flags & IFF_LOOPBACK)
1167                 flags |= RTCF_LOCAL;
1168
1169         rt = dst_alloc(&dn_dst_ops, dev_out, 1, 0, DST_HOST);
1170         if (rt == NULL)
1171                 goto e_nobufs;
1172
1173         memset(&rt->fld, 0, sizeof(rt->fld));
1174         rt->fld.saddr        = oldflp->saddr;
1175         rt->fld.daddr        = oldflp->daddr;
1176         rt->fld.flowidn_oif  = oldflp->flowidn_oif;
1177         rt->fld.flowidn_iif  = 0;
1178         rt->fld.flowidn_mark = oldflp->flowidn_mark;
1179
1180         rt->rt_saddr      = fld.saddr;
1181         rt->rt_daddr      = fld.daddr;
1182         rt->rt_gateway    = gateway ? gateway : fld.daddr;
1183         rt->rt_local_src  = fld.saddr;
1184
1185         rt->rt_dst_map    = fld.daddr;
1186         rt->rt_src_map    = fld.saddr;
1187
1188         rt->n = neigh;
1189         neigh = NULL;
1190
1191         rt->dst.lastuse = jiffies;
1192         rt->dst.output  = dn_output;
1193         rt->dst.input   = dn_rt_bug;
1194         rt->rt_flags      = flags;
1195         if (flags & RTCF_LOCAL)
1196                 rt->dst.input = dn_nsp_rx;
1197
1198         err = dn_rt_set_next_hop(rt, &res);
1199         if (err)
1200                 goto e_neighbour;
1201
1202         hash = dn_hash(rt->fld.saddr, rt->fld.daddr);
1203         dn_insert_route(rt, hash, (struct dn_route **)pprt);
1204
1205 done:
1206         if (neigh)
1207                 neigh_release(neigh);
1208         if (free_res)
1209                 dn_fib_res_put(&res);
1210         if (dev_out)
1211                 dev_put(dev_out);
1212 out:
1213         return err;
1214
1215 e_addr:
1216         err = -EADDRNOTAVAIL;
1217         goto done;
1218 e_inval:
1219         err = -EINVAL;
1220         goto done;
1221 e_nobufs:
1222         err = -ENOBUFS;
1223         goto done;
1224 e_neighbour:
1225         dst_free(&rt->dst);
1226         goto e_nobufs;
1227 }
1228
1229
1230 /*
1231  * N.B. The flags may be moved into the flowi at some future stage.
1232  */
1233 static int __dn_route_output_key(struct dst_entry **pprt, const struct flowidn *flp, int flags)
1234 {
1235         unsigned int hash = dn_hash(flp->saddr, flp->daddr);
1236         struct dn_route *rt = NULL;
1237
1238         if (!(flags & MSG_TRYHARD)) {
1239                 rcu_read_lock_bh();
1240                 for (rt = rcu_dereference_bh(dn_rt_hash_table[hash].chain); rt;
1241                         rt = rcu_dereference_bh(rt->dst.dn_next)) {
1242                         if ((flp->daddr == rt->fld.daddr) &&
1243                             (flp->saddr == rt->fld.saddr) &&
1244                             (flp->flowidn_mark == rt->fld.flowidn_mark) &&
1245                             dn_is_output_route(rt) &&
1246                             (rt->fld.flowidn_oif == flp->flowidn_oif)) {
1247                                 dst_use(&rt->dst, jiffies);
1248                                 rcu_read_unlock_bh();
1249                                 *pprt = &rt->dst;
1250                                 return 0;
1251                         }
1252                 }
1253                 rcu_read_unlock_bh();
1254         }
1255
1256         return dn_route_output_slow(pprt, flp, flags);
1257 }
1258
1259 static int dn_route_output_key(struct dst_entry **pprt, struct flowidn *flp, int flags)
1260 {
1261         int err;
1262
1263         err = __dn_route_output_key(pprt, flp, flags);
1264         if (err == 0 && flp->flowidn_proto) {
1265                 *pprt = xfrm_lookup(&init_net, *pprt,
1266                                     flowidn_to_flowi(flp), NULL, 0);
1267                 if (IS_ERR(*pprt)) {
1268                         err = PTR_ERR(*pprt);
1269                         *pprt = NULL;
1270                 }
1271         }
1272         return err;
1273 }
1274
1275 int dn_route_output_sock(struct dst_entry **pprt, struct flowidn *fl, struct sock *sk, int flags)
1276 {
1277         int err;
1278
1279         err = __dn_route_output_key(pprt, fl, flags & MSG_TRYHARD);
1280         if (err == 0 && fl->flowidn_proto) {
1281                 if (!(flags & MSG_DONTWAIT))
1282                         fl->flowidn_flags |= FLOWI_FLAG_CAN_SLEEP;
1283                 *pprt = xfrm_lookup(&init_net, *pprt,
1284                                     flowidn_to_flowi(fl), sk, 0);
1285                 if (IS_ERR(*pprt)) {
1286                         err = PTR_ERR(*pprt);
1287                         *pprt = NULL;
1288                 }
1289         }
1290         return err;
1291 }
1292
1293 static int dn_route_input_slow(struct sk_buff *skb)
1294 {
1295         struct dn_route *rt = NULL;
1296         struct dn_skb_cb *cb = DN_SKB_CB(skb);
1297         struct net_device *in_dev = skb->dev;
1298         struct net_device *out_dev = NULL;
1299         struct dn_dev *dn_db;
1300         struct neighbour *neigh = NULL;
1301         unsigned int hash;
1302         int flags = 0;
1303         __le16 gateway = 0;
1304         __le16 local_src = 0;
1305         struct flowidn fld = {
1306                 .daddr = cb->dst,
1307                 .saddr = cb->src,
1308                 .flowidn_scope = RT_SCOPE_UNIVERSE,
1309                 .flowidn_mark = skb->mark,
1310                 .flowidn_iif = skb->dev->ifindex,
1311         };
1312         struct dn_fib_res res = { .fi = NULL, .type = RTN_UNREACHABLE };
1313         int err = -EINVAL;
1314         int free_res = 0;
1315
1316         dev_hold(in_dev);
1317
1318         if ((dn_db = rcu_dereference(in_dev->dn_ptr)) == NULL)
1319                 goto out;
1320
1321         /* Zero source addresses are not allowed */
1322         if (fld.saddr == 0)
1323                 goto out;
1324
1325         /*
1326          * In this case we've just received a packet from a source
1327          * outside ourselves pretending to come from us. We don't
1328          * allow it any further to prevent routing loops, spoofing and
1329          * other nasties. Loopback packets already have the dst attached
1330          * so this only affects packets which have originated elsewhere.
1331          */
1332         err  = -ENOTUNIQ;
1333         if (dn_dev_islocal(in_dev, cb->src))
1334                 goto out;
1335
1336         err = dn_fib_lookup(&fld, &res);
1337         if (err) {
1338                 if (err != -ESRCH)
1339                         goto out;
1340                 /*
1341                  * Is the destination us ?
1342                  */
1343                 if (!dn_dev_islocal(in_dev, cb->dst))
1344                         goto e_inval;
1345
1346                 res.type = RTN_LOCAL;
1347         } else {
1348                 __le16 src_map = fld.saddr;
1349                 free_res = 1;
1350
1351                 out_dev = DN_FIB_RES_DEV(res);
1352                 if (out_dev == NULL) {
1353                         net_crit_ratelimited("Bug in dn_route_input_slow() No output device\n");
1354                         goto e_inval;
1355                 }
1356                 dev_hold(out_dev);
1357
1358                 if (res.r)
1359                         src_map = fld.saddr; /* no NAT support for now */
1360
1361                 gateway = DN_FIB_RES_GW(res);
1362                 if (res.type == RTN_NAT) {
1363                         fld.daddr = dn_fib_rules_map_destination(fld.daddr, &res);
1364                         dn_fib_res_put(&res);
1365                         free_res = 0;
1366                         if (dn_fib_lookup(&fld, &res))
1367                                 goto e_inval;
1368                         free_res = 1;
1369                         if (res.type != RTN_UNICAST)
1370                                 goto e_inval;
1371                         flags |= RTCF_DNAT;
1372                         gateway = fld.daddr;
1373                 }
1374                 fld.saddr = src_map;
1375         }
1376
1377         switch(res.type) {
1378         case RTN_UNICAST:
1379                 /*
1380                  * Forwarding check here, we only check for forwarding
1381                  * being turned off, if you want to only forward intra
1382                  * area, its up to you to set the routing tables up
1383                  * correctly.
1384                  */
1385                 if (dn_db->parms.forwarding == 0)
1386                         goto e_inval;
1387
1388                 if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1389                         dn_fib_select_multipath(&fld, &res);
1390
1391                 /*
1392                  * Check for out_dev == in_dev. We use the RTCF_DOREDIRECT
1393                  * flag as a hint to set the intra-ethernet bit when
1394                  * forwarding. If we've got NAT in operation, we don't do
1395                  * this optimisation.
1396                  */
1397                 if (out_dev == in_dev && !(flags & RTCF_NAT))
1398                         flags |= RTCF_DOREDIRECT;
1399
1400                 local_src = DN_FIB_RES_PREFSRC(res);
1401
1402         case RTN_BLACKHOLE:
1403         case RTN_UNREACHABLE:
1404                 break;
1405         case RTN_LOCAL:
1406                 flags |= RTCF_LOCAL;
1407                 fld.saddr = cb->dst;
1408                 fld.daddr = cb->src;
1409
1410                 /* Routing tables gave us a gateway */
1411                 if (gateway)
1412                         goto make_route;
1413
1414                 /* Packet was intra-ethernet, so we know its on-link */
1415                 if (cb->rt_flags & DN_RT_F_IE) {
1416                         gateway = cb->src;
1417                         flags |= RTCF_DIRECTSRC;
1418                         goto make_route;
1419                 }
1420
1421                 /* Use the default router if there is one */
1422                 neigh = neigh_clone(dn_db->router);
1423                 if (neigh) {
1424                         gateway = ((struct dn_neigh *)neigh)->addr;
1425                         goto make_route;
1426                 }
1427
1428                 /* Close eyes and pray */
1429                 gateway = cb->src;
1430                 flags |= RTCF_DIRECTSRC;
1431                 goto make_route;
1432         default:
1433                 goto e_inval;
1434         }
1435
1436 make_route:
1437         rt = dst_alloc(&dn_dst_ops, out_dev, 0, 0, DST_HOST);
1438         if (rt == NULL)
1439                 goto e_nobufs;
1440
1441         memset(&rt->fld, 0, sizeof(rt->fld));
1442         rt->rt_saddr      = fld.saddr;
1443         rt->rt_daddr      = fld.daddr;
1444         rt->rt_gateway    = fld.daddr;
1445         if (gateway)
1446                 rt->rt_gateway = gateway;
1447         rt->rt_local_src  = local_src ? local_src : rt->rt_saddr;
1448
1449         rt->rt_dst_map    = fld.daddr;
1450         rt->rt_src_map    = fld.saddr;
1451
1452         rt->fld.saddr        = cb->src;
1453         rt->fld.daddr        = cb->dst;
1454         rt->fld.flowidn_oif  = 0;
1455         rt->fld.flowidn_iif  = in_dev->ifindex;
1456         rt->fld.flowidn_mark = fld.flowidn_mark;
1457
1458         rt->n = neigh;
1459         rt->dst.lastuse = jiffies;
1460         rt->dst.output = dn_rt_bug;
1461         switch (res.type) {
1462         case RTN_UNICAST:
1463                 rt->dst.input = dn_forward;
1464                 break;
1465         case RTN_LOCAL:
1466                 rt->dst.output = dn_output;
1467                 rt->dst.input = dn_nsp_rx;
1468                 rt->dst.dev = in_dev;
1469                 flags |= RTCF_LOCAL;
1470                 break;
1471         default:
1472         case RTN_UNREACHABLE:
1473         case RTN_BLACKHOLE:
1474                 rt->dst.input = dst_discard;
1475         }
1476         rt->rt_flags = flags;
1477
1478         err = dn_rt_set_next_hop(rt, &res);
1479         if (err)
1480                 goto e_neighbour;
1481
1482         hash = dn_hash(rt->fld.saddr, rt->fld.daddr);
1483         dn_insert_route(rt, hash, &rt);
1484         skb_dst_set(skb, &rt->dst);
1485
1486 done:
1487         if (neigh)
1488                 neigh_release(neigh);
1489         if (free_res)
1490                 dn_fib_res_put(&res);
1491         dev_put(in_dev);
1492         if (out_dev)
1493                 dev_put(out_dev);
1494 out:
1495         return err;
1496
1497 e_inval:
1498         err = -EINVAL;
1499         goto done;
1500
1501 e_nobufs:
1502         err = -ENOBUFS;
1503         goto done;
1504
1505 e_neighbour:
1506         dst_free(&rt->dst);
1507         goto done;
1508 }
1509
1510 static int dn_route_input(struct sk_buff *skb)
1511 {
1512         struct dn_route *rt;
1513         struct dn_skb_cb *cb = DN_SKB_CB(skb);
1514         unsigned int hash = dn_hash(cb->src, cb->dst);
1515
1516         if (skb_dst(skb))
1517                 return 0;
1518
1519         rcu_read_lock();
1520         for(rt = rcu_dereference(dn_rt_hash_table[hash].chain); rt != NULL;
1521             rt = rcu_dereference(rt->dst.dn_next)) {
1522                 if ((rt->fld.saddr == cb->src) &&
1523                     (rt->fld.daddr == cb->dst) &&
1524                     (rt->fld.flowidn_oif == 0) &&
1525                     (rt->fld.flowidn_mark == skb->mark) &&
1526                     (rt->fld.flowidn_iif == cb->iif)) {
1527                         dst_use(&rt->dst, jiffies);
1528                         rcu_read_unlock();
1529                         skb_dst_set(skb, (struct dst_entry *)rt);
1530                         return 0;
1531                 }
1532         }
1533         rcu_read_unlock();
1534
1535         return dn_route_input_slow(skb);
1536 }
1537
1538 static int dn_rt_fill_info(struct sk_buff *skb, u32 pid, u32 seq,
1539                            int event, int nowait, unsigned int flags)
1540 {
1541         struct dn_route *rt = (struct dn_route *)skb_dst(skb);
1542         struct rtmsg *r;
1543         struct nlmsghdr *nlh;
1544         long expires;
1545
1546         nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
1547         if (!nlh)
1548                 return -EMSGSIZE;
1549
1550         r = nlmsg_data(nlh);
1551         r->rtm_family = AF_DECnet;
1552         r->rtm_dst_len = 16;
1553         r->rtm_src_len = 0;
1554         r->rtm_tos = 0;
1555         r->rtm_table = RT_TABLE_MAIN;
1556         r->rtm_type = rt->rt_type;
1557         r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
1558         r->rtm_scope = RT_SCOPE_UNIVERSE;
1559         r->rtm_protocol = RTPROT_UNSPEC;
1560
1561         if (rt->rt_flags & RTCF_NOTIFY)
1562                 r->rtm_flags |= RTM_F_NOTIFY;
1563
1564         if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN) < 0 ||
1565             nla_put_le16(skb, RTA_DST, rt->rt_daddr) < 0)
1566                 goto errout;
1567
1568         if (rt->fld.saddr) {
1569                 r->rtm_src_len = 16;
1570                 if (nla_put_le16(skb, RTA_SRC, rt->fld.saddr) < 0)
1571                         goto errout;
1572         }
1573         if (rt->dst.dev &&
1574             nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex) < 0)
1575                 goto errout;
1576
1577         /*
1578          * Note to self - change this if input routes reverse direction when
1579          * they deal only with inputs and not with replies like they do
1580          * currently.
1581          */
1582         if (nla_put_le16(skb, RTA_PREFSRC, rt->rt_local_src) < 0)
1583                 goto errout;
1584
1585         if (rt->rt_daddr != rt->rt_gateway &&
1586             nla_put_le16(skb, RTA_GATEWAY, rt->rt_gateway) < 0)
1587                 goto errout;
1588
1589         if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
1590                 goto errout;
1591
1592         expires = rt->dst.expires ? rt->dst.expires - jiffies : 0;
1593         if (rtnl_put_cacheinfo(skb, &rt->dst, 0, 0, 0, expires,
1594                                rt->dst.error) < 0)
1595                 goto errout;
1596
1597         if (dn_is_input_route(rt) &&
1598             nla_put_u32(skb, RTA_IIF, rt->fld.flowidn_iif) < 0)
1599                 goto errout;
1600
1601         return nlmsg_end(skb, nlh);
1602
1603 errout:
1604         nlmsg_cancel(skb, nlh);
1605         return -EMSGSIZE;
1606 }
1607
1608 /*
1609  * This is called by both endnodes and routers now.
1610  */
1611 static int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, void *arg)
1612 {
1613         struct net *net = sock_net(in_skb->sk);
1614         struct rtattr **rta = arg;
1615         struct rtmsg *rtm = nlmsg_data(nlh);
1616         struct dn_route *rt = NULL;
1617         struct dn_skb_cb *cb;
1618         int err;
1619         struct sk_buff *skb;
1620         struct flowidn fld;
1621
1622         if (!net_eq(net, &init_net))
1623                 return -EINVAL;
1624
1625         memset(&fld, 0, sizeof(fld));
1626         fld.flowidn_proto = DNPROTO_NSP;
1627
1628         skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1629         if (skb == NULL)
1630                 return -ENOBUFS;
1631         skb_reset_mac_header(skb);
1632         cb = DN_SKB_CB(skb);
1633
1634         if (rta[RTA_SRC-1])
1635                 memcpy(&fld.saddr, RTA_DATA(rta[RTA_SRC-1]), 2);
1636         if (rta[RTA_DST-1])
1637                 memcpy(&fld.daddr, RTA_DATA(rta[RTA_DST-1]), 2);
1638         if (rta[RTA_IIF-1])
1639                 memcpy(&fld.flowidn_iif, RTA_DATA(rta[RTA_IIF-1]), sizeof(int));
1640
1641         if (fld.flowidn_iif) {
1642                 struct net_device *dev;
1643                 if ((dev = dev_get_by_index(&init_net, fld.flowidn_iif)) == NULL) {
1644                         kfree_skb(skb);
1645                         return -ENODEV;
1646                 }
1647                 if (!dev->dn_ptr) {
1648                         dev_put(dev);
1649                         kfree_skb(skb);
1650                         return -ENODEV;
1651                 }
1652                 skb->protocol = htons(ETH_P_DNA_RT);
1653                 skb->dev = dev;
1654                 cb->src = fld.saddr;
1655                 cb->dst = fld.daddr;
1656                 local_bh_disable();
1657                 err = dn_route_input(skb);
1658                 local_bh_enable();
1659                 memset(cb, 0, sizeof(struct dn_skb_cb));
1660                 rt = (struct dn_route *)skb_dst(skb);
1661                 if (!err && -rt->dst.error)
1662                         err = rt->dst.error;
1663         } else {
1664                 int oif = 0;
1665                 if (rta[RTA_OIF - 1])
1666                         memcpy(&oif, RTA_DATA(rta[RTA_OIF - 1]), sizeof(int));
1667                 fld.flowidn_oif = oif;
1668                 err = dn_route_output_key((struct dst_entry **)&rt, &fld, 0);
1669         }
1670
1671         if (skb->dev)
1672                 dev_put(skb->dev);
1673         skb->dev = NULL;
1674         if (err)
1675                 goto out_free;
1676         skb_dst_set(skb, &rt->dst);
1677         if (rtm->rtm_flags & RTM_F_NOTIFY)
1678                 rt->rt_flags |= RTCF_NOTIFY;
1679
1680         err = dn_rt_fill_info(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, RTM_NEWROUTE, 0, 0);
1681
1682         if (err == 0)
1683                 goto out_free;
1684         if (err < 0) {
1685                 err = -EMSGSIZE;
1686                 goto out_free;
1687         }
1688
1689         return rtnl_unicast(skb, &init_net, NETLINK_CB(in_skb).pid);
1690
1691 out_free:
1692         kfree_skb(skb);
1693         return err;
1694 }
1695
1696 /*
1697  * For routers, this is called from dn_fib_dump, but for endnodes its
1698  * called directly from the rtnetlink dispatch table.
1699  */
1700 int dn_cache_dump(struct sk_buff *skb, struct netlink_callback *cb)
1701 {
1702         struct net *net = sock_net(skb->sk);
1703         struct dn_route *rt;
1704         int h, s_h;
1705         int idx, s_idx;
1706         struct rtmsg *rtm;
1707
1708         if (!net_eq(net, &init_net))
1709                 return 0;
1710
1711         if (nlmsg_len(cb->nlh) < sizeof(struct rtmsg))
1712                 return -EINVAL;
1713
1714         rtm = nlmsg_data(cb->nlh);
1715         if (!(rtm->rtm_flags & RTM_F_CLONED))
1716                 return 0;
1717
1718         s_h = cb->args[0];
1719         s_idx = idx = cb->args[1];
1720         for(h = 0; h <= dn_rt_hash_mask; h++) {
1721                 if (h < s_h)
1722                         continue;
1723                 if (h > s_h)
1724                         s_idx = 0;
1725                 rcu_read_lock_bh();
1726                 for(rt = rcu_dereference_bh(dn_rt_hash_table[h].chain), idx = 0;
1727                         rt;
1728                         rt = rcu_dereference_bh(rt->dst.dn_next), idx++) {
1729                         if (idx < s_idx)
1730                                 continue;
1731                         skb_dst_set(skb, dst_clone(&rt->dst));
1732                         if (dn_rt_fill_info(skb, NETLINK_CB(cb->skb).pid,
1733                                         cb->nlh->nlmsg_seq, RTM_NEWROUTE,
1734                                         1, NLM_F_MULTI) <= 0) {
1735                                 skb_dst_drop(skb);
1736                                 rcu_read_unlock_bh();
1737                                 goto done;
1738                         }
1739                         skb_dst_drop(skb);
1740                 }
1741                 rcu_read_unlock_bh();
1742         }
1743
1744 done:
1745         cb->args[0] = h;
1746         cb->args[1] = idx;
1747         return skb->len;
1748 }
1749
1750 #ifdef CONFIG_PROC_FS
1751 struct dn_rt_cache_iter_state {
1752         int bucket;
1753 };
1754
1755 static struct dn_route *dn_rt_cache_get_first(struct seq_file *seq)
1756 {
1757         struct dn_route *rt = NULL;
1758         struct dn_rt_cache_iter_state *s = seq->private;
1759
1760         for(s->bucket = dn_rt_hash_mask; s->bucket >= 0; --s->bucket) {
1761                 rcu_read_lock_bh();
1762                 rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1763                 if (rt)
1764                         break;
1765                 rcu_read_unlock_bh();
1766         }
1767         return rt;
1768 }
1769
1770 static struct dn_route *dn_rt_cache_get_next(struct seq_file *seq, struct dn_route *rt)
1771 {
1772         struct dn_rt_cache_iter_state *s = seq->private;
1773
1774         rt = rcu_dereference_bh(rt->dst.dn_next);
1775         while (!rt) {
1776                 rcu_read_unlock_bh();
1777                 if (--s->bucket < 0)
1778                         break;
1779                 rcu_read_lock_bh();
1780                 rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1781         }
1782         return rt;
1783 }
1784
1785 static void *dn_rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
1786 {
1787         struct dn_route *rt = dn_rt_cache_get_first(seq);
1788
1789         if (rt) {
1790                 while(*pos && (rt = dn_rt_cache_get_next(seq, rt)))
1791                         --*pos;
1792         }
1793         return *pos ? NULL : rt;
1794 }
1795
1796 static void *dn_rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1797 {
1798         struct dn_route *rt = dn_rt_cache_get_next(seq, v);
1799         ++*pos;
1800         return rt;
1801 }
1802
1803 static void dn_rt_cache_seq_stop(struct seq_file *seq, void *v)
1804 {
1805         if (v)
1806                 rcu_read_unlock_bh();
1807 }
1808
1809 static int dn_rt_cache_seq_show(struct seq_file *seq, void *v)
1810 {
1811         struct dn_route *rt = v;
1812         char buf1[DN_ASCBUF_LEN], buf2[DN_ASCBUF_LEN];
1813
1814         seq_printf(seq, "%-8s %-7s %-7s %04d %04d %04d\n",
1815                    rt->dst.dev ? rt->dst.dev->name : "*",
1816                    dn_addr2asc(le16_to_cpu(rt->rt_daddr), buf1),
1817                    dn_addr2asc(le16_to_cpu(rt->rt_saddr), buf2),
1818                    atomic_read(&rt->dst.__refcnt),
1819                    rt->dst.__use, 0);
1820         return 0;
1821 }
1822
1823 static const struct seq_operations dn_rt_cache_seq_ops = {
1824         .start  = dn_rt_cache_seq_start,
1825         .next   = dn_rt_cache_seq_next,
1826         .stop   = dn_rt_cache_seq_stop,
1827         .show   = dn_rt_cache_seq_show,
1828 };
1829
1830 static int dn_rt_cache_seq_open(struct inode *inode, struct file *file)
1831 {
1832         return seq_open_private(file, &dn_rt_cache_seq_ops,
1833                         sizeof(struct dn_rt_cache_iter_state));
1834 }
1835
1836 static const struct file_operations dn_rt_cache_seq_fops = {
1837         .owner   = THIS_MODULE,
1838         .open    = dn_rt_cache_seq_open,
1839         .read    = seq_read,
1840         .llseek  = seq_lseek,
1841         .release = seq_release_private,
1842 };
1843
1844 #endif /* CONFIG_PROC_FS */
1845
1846 void __init dn_route_init(void)
1847 {
1848         int i, goal, order;
1849
1850         dn_dst_ops.kmem_cachep =
1851                 kmem_cache_create("dn_dst_cache", sizeof(struct dn_route), 0,
1852                                   SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
1853         dst_entries_init(&dn_dst_ops);
1854         setup_timer(&dn_route_timer, dn_dst_check_expire, 0);
1855         dn_route_timer.expires = jiffies + decnet_dst_gc_interval * HZ;
1856         add_timer(&dn_route_timer);
1857
1858         goal = totalram_pages >> (26 - PAGE_SHIFT);
1859
1860         for(order = 0; (1UL << order) < goal; order++)
1861                 /* NOTHING */;
1862
1863         /*
1864          * Only want 1024 entries max, since the table is very, very unlikely
1865          * to be larger than that.
1866          */
1867         while(order && ((((1UL << order) * PAGE_SIZE) /
1868                                 sizeof(struct dn_rt_hash_bucket)) >= 2048))
1869                 order--;
1870
1871         do {
1872                 dn_rt_hash_mask = (1UL << order) * PAGE_SIZE /
1873                         sizeof(struct dn_rt_hash_bucket);
1874                 while(dn_rt_hash_mask & (dn_rt_hash_mask - 1))
1875                         dn_rt_hash_mask--;
1876                 dn_rt_hash_table = (struct dn_rt_hash_bucket *)
1877                         __get_free_pages(GFP_ATOMIC, order);
1878         } while (dn_rt_hash_table == NULL && --order > 0);
1879
1880         if (!dn_rt_hash_table)
1881                 panic("Failed to allocate DECnet route cache hash table\n");
1882
1883         printk(KERN_INFO
1884                 "DECnet: Routing cache hash table of %u buckets, %ldKbytes\n",
1885                 dn_rt_hash_mask,
1886                 (long)(dn_rt_hash_mask*sizeof(struct dn_rt_hash_bucket))/1024);
1887
1888         dn_rt_hash_mask--;
1889         for(i = 0; i <= dn_rt_hash_mask; i++) {
1890                 spin_lock_init(&dn_rt_hash_table[i].lock);
1891                 dn_rt_hash_table[i].chain = NULL;
1892         }
1893
1894         dn_dst_ops.gc_thresh = (dn_rt_hash_mask + 1);
1895
1896         proc_net_fops_create(&init_net, "decnet_cache", S_IRUGO, &dn_rt_cache_seq_fops);
1897
1898 #ifdef CONFIG_DECNET_ROUTER
1899         rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute,
1900                       dn_fib_dump, NULL);
1901 #else
1902         rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute,
1903                       dn_cache_dump, NULL);
1904 #endif
1905 }
1906
1907 void __exit dn_route_cleanup(void)
1908 {
1909         del_timer(&dn_route_timer);
1910         dn_run_flush(0);
1911
1912         proc_net_remove(&init_net, "decnet_cache");
1913         dst_entries_destroy(&dn_dst_ops);
1914 }
1915