net/decnet/dn_route.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   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 Functions (Endnode and Router)
   8  *
   9  * Authors:     Steve Whitehouse <SteveW@ACM.org>
  10  *              Eduardo Marcelo Serrat <emserrat@geocities.com>
  11  *
  12  * Changes:
  13  *              Steve Whitehouse : Fixes to allow "intra-ethernet" and
  14  *                                 "return-to-sender" bits on outgoing
  15  *                                 packets.
  16  *              Steve Whitehouse : Timeouts for cached routes.
  17  *              Steve Whitehouse : Use dst cache for input routes too.
  18  *              Steve Whitehouse : Fixed error values in dn_send_skb.
  19  *              Steve Whitehouse : Rework routing functions to better fit
  20  *                                 DECnet routing design
  21  *              Alexey Kuznetsov : New SMP locking
  22  *              Steve Whitehouse : More SMP locking changes & dn_cache_dump()
  23  *              Steve Whitehouse : Prerouting NF hook, now really is prerouting.
  24  *                                 Fixed possible skb leak in rtnetlink funcs.
  25  *              Steve Whitehouse : Dave Miller's dynamic hash table sizing and
  26  *                                 Alexey Kuznetsov's finer grained locking
  27  *                                 from ipv4/route.c.
  28  *              Steve Whitehouse : Routing is now starting to look like a
  29  *                                 sensible set of code now, mainly due to
  30  *                                 my copying the IPv4 routing code. The
  31  *                                 hooks here are modified and will continue
  32  *                                 to evolve for a while.
  33  *              Steve Whitehouse : Real SMP at last :-) Also new netfilter
  34  *                                 stuff. Look out raw sockets your days
  35  *                                 are numbered!
  36  *              Steve Whitehouse : Added return-to-sender functions. Added
  37  *                                 backlog congestion level return codes.
  38  *              Steve Whitehouse : Fixed bug where routes were set up with
  39  *                                 no ref count on net devices.
  40  *              Steve Whitehouse : RCU for the route cache
  41  *              Steve Whitehouse : Preparations for the flow cache
  42  *              Steve Whitehouse : Prepare for nonlinear skbs
  43  */
  44
  45 /******************************************************************************
  46     (c) 1995-1998 E.M. Serrat           emserrat@geocities.com
  47
  48 *******************************************************************************/
  49
  50 #include <linux/errno.h>
  51 #include <linux/types.h>
  52 #include <linux/socket.h>
  53 #include <linux/in.h>
  54 #include <linux/kernel.h>
  55 #include <linux/sockios.h>
  56 #include <linux/net.h>
  57 #include <linux/netdevice.h>
  58 #include <linux/inet.h>
  59 #include <linux/route.h>
  60 #include <linux/in_route.h>
  61 #include <linux/slab.h>
  62 #include <net/sock.h>
  63 #include <linux/mm.h>
  64 #include <linux/proc_fs.h>
  65 #include <linux/seq_file.h>
  66 #include <linux/init.h>
  67 #include <linux/rtnetlink.h>
  68 #include <linux/string.h>
  69 #include <linux/netfilter_decnet.h>
  70 #include <linux/rcupdate.h>
  71 #include <linux/times.h>
  72 #include <linux/export.h>
  73 #include <asm/errno.h>
  74 #include <net/net_namespace.h>
  75 #include <net/netlink.h>
  76 #include <net/neighbour.h>
  77 #include <net/dst.h>
  78 #include <net/flow.h>
  79 #include <net/fib_rules.h>
  80 #include <net/dn.h>
  81 #include <net/dn_dev.h>
  82 #include <net/dn_nsp.h>
  83 #include <net/dn_route.h>
  84 #include <net/dn_neigh.h>
  85 #include <net/dn_fib.h>
  86
  87 struct dn_rt_hash_bucket
  88 {
  89         struct dn_route __rcu *chain;
  90         spinlock_t lock;
  91 };
  92
  93 extern struct neigh_table dn_neigh_table;
  94
  95
  96 static unsigned char dn_hiord_addr[6] = {0xAA,0x00,0x04,0x00,0x00,0x00};
  97
  98 static const int dn_rt_min_delay = 2 * HZ;
  99 static const int dn_rt_max_delay = 10 * HZ;
 100 static const int dn_rt_mtu_expires = 10 * 60 * HZ;
 101
 102 static unsigned long dn_rt_deadline;
 103
 104 static int dn_dst_gc(struct dst_ops *ops);
 105 static struct dst_entry *dn_dst_check(struct dst_entry *, __u32);
 106 static unsigned int dn_dst_default_advmss(const struct dst_entry *dst);
 107 static unsigned int dn_dst_mtu(const struct dst_entry *dst);
 108 static void dn_dst_destroy(struct dst_entry *);
 109 static void dn_dst_ifdown(struct dst_entry *, struct net_device *dev, int how);
 110 static struct dst_entry *dn_dst_negative_advice(struct dst_entry *);
 111 static void dn_dst_link_failure(struct sk_buff *);
 112 static void dn_dst_update_pmtu(struct dst_entry *dst, struct sock *sk,
 113                                struct sk_buff *skb , u32 mtu);
 114 static void dn_dst_redirect(struct dst_entry *dst, struct sock *sk,
 115                             struct sk_buff *skb);
 116 static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst,
 117                                              struct sk_buff *skb,
 118                                              const void *daddr);
 119 static int dn_route_input(struct sk_buff *);
 120 static void dn_run_flush(struct timer_list *unused);
 121
 122 static struct dn_rt_hash_bucket *dn_rt_hash_table;
 123 static unsigned int dn_rt_hash_mask;
 124
 125 static struct timer_list dn_route_timer;
 126 static DEFINE_TIMER(dn_rt_flush_timer, dn_run_flush);
 127 int decnet_dst_gc_interval = 2;
 128
 129 static struct dst_ops dn_dst_ops = {
 130         .family =               PF_DECnet,
 131         .gc_thresh =            128,
 132         .gc =                   dn_dst_gc,
 133         .check =                dn_dst_check,
 134         .default_advmss =       dn_dst_default_advmss,
 135         .mtu =                  dn_dst_mtu,
 136         .cow_metrics =          dst_cow_metrics_generic,
 137         .destroy =              dn_dst_destroy,
 138         .ifdown =               dn_dst_ifdown,
 139         .negative_advice =      dn_dst_negative_advice,
 140         .link_failure =         dn_dst_link_failure,
 141         .update_pmtu =          dn_dst_update_pmtu,
 142         .redirect =             dn_dst_redirect,
 143         .neigh_lookup =         dn_dst_neigh_lookup,
 144 };
 145
 146 static void dn_dst_destroy(struct dst_entry *dst)
 147 {
 148         struct dn_route *rt = (struct dn_route *) dst;
 149
 150         if (rt->n)
 151                 neigh_release(rt->n);
 152         dst_destroy_metrics_generic(dst);
 153 }
 154
 155 static void dn_dst_ifdown(struct dst_entry *dst, struct net_device *dev, int how)
 156 {
 157         if (how) {
 158                 struct dn_route *rt = (struct dn_route *) dst;
 159                 struct neighbour *n = rt->n;
 160
 161                 if (n && n->dev == dev) {
 162                         n->dev = dev_net(dev)->loopback_dev;
 163                         dev_hold(n->dev);
 164                         dev_put(dev);
 165                 }
 166         }
 167 }
 168
 169 static __inline__ unsigned int dn_hash(__le16 src, __le16 dst)
 170 {
 171         __u16 tmp = (__u16 __force)(src ^ dst);
 172         tmp ^= (tmp >> 3);
 173         tmp ^= (tmp >> 5);
 174         tmp ^= (tmp >> 10);
 175         return dn_rt_hash_mask & (unsigned int)tmp;
 176 }
 177
 178 static void dn_dst_check_expire(struct timer_list *unused)
 179 {
 180         int i;
 181         struct dn_route *rt;
 182         struct dn_route __rcu **rtp;
 183         unsigned long now = jiffies;
 184         unsigned long expire = 120 * HZ;
 185
 186         for (i = 0; i <= dn_rt_hash_mask; i++) {
 187                 rtp = &dn_rt_hash_table[i].chain;
 188
 189                 spin_lock(&dn_rt_hash_table[i].lock);
 190                 while ((rt = rcu_dereference_protected(*rtp,
 191                                                 lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) {
 192                         if (atomic_read(&rt->dst.__refcnt) > 1 ||
 193                             (now - rt->dst.lastuse) < expire) {
 194                                 rtp = &rt->dn_next;
 195                                 continue;
 196                         }
 197                         *rtp = rt->dn_next;
 198                         rt->dn_next = NULL;
 199                         dst_dev_put(&rt->dst);
 200                         dst_release(&rt->dst);
 201                 }
 202                 spin_unlock(&dn_rt_hash_table[i].lock);
 203
 204                 if ((jiffies - now) > 0)
 205                         break;
 206         }
 207
 208         mod_timer(&dn_route_timer, now + decnet_dst_gc_interval * HZ);
 209 }
 210
 211 static int dn_dst_gc(struct dst_ops *ops)
 212 {
 213         struct dn_route *rt;
 214         struct dn_route __rcu **rtp;
 215         int i;
 216         unsigned long now = jiffies;
 217         unsigned long expire = 10 * HZ;
 218
 219         for (i = 0; i <= dn_rt_hash_mask; i++) {
 220
 221                 spin_lock_bh(&dn_rt_hash_table[i].lock);
 222                 rtp = &dn_rt_hash_table[i].chain;
 223
 224                 while ((rt = rcu_dereference_protected(*rtp,
 225                                                 lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) {
 226                         if (atomic_read(&rt->dst.__refcnt) > 1 ||
 227                             (now - rt->dst.lastuse) < expire) {
 228                                 rtp = &rt->dn_next;
 229                                 continue;
 230                         }
 231                         *rtp = rt->dn_next;
 232                         rt->dn_next = NULL;
 233                         dst_dev_put(&rt->dst);
 234                         dst_release(&rt->dst);
 235                         break;
 236                 }
 237                 spin_unlock_bh(&dn_rt_hash_table[i].lock);
 238         }
 239
 240         return 0;
 241 }
 242
 243 /*
 244  * The decnet standards don't impose a particular minimum mtu, what they
 245  * do insist on is that the routing layer accepts a datagram of at least
 246  * 230 bytes long. Here we have to subtract the routing header length from
 247  * 230 to get the minimum acceptable mtu. If there is no neighbour, then we
 248  * assume the worst and use a long header size.
 249  *
 250  * We update both the mtu and the advertised mss (i.e. the segment size we
 251  * advertise to the other end).
 252  */
 253 static void dn_dst_update_pmtu(struct dst_entry *dst, struct sock *sk,
 254                                struct sk_buff *skb, u32 mtu)
 255 {
 256         struct dn_route *rt = (struct dn_route *) dst;
 257         struct neighbour *n = rt->n;
 258         u32 min_mtu = 230;
 259         struct dn_dev *dn;
 260
 261         dn = n ? rcu_dereference_raw(n->dev->dn_ptr) : NULL;
 262
 263         if (dn && dn->use_long == 0)
 264                 min_mtu -= 6;
 265         else
 266                 min_mtu -= 21;
 267
 268         if (dst_metric(dst, RTAX_MTU) > mtu && mtu >= min_mtu) {
 269                 if (!(dst_metric_locked(dst, RTAX_MTU))) {
 270                         dst_metric_set(dst, RTAX_MTU, mtu);
 271                         dst_set_expires(dst, dn_rt_mtu_expires);
 272                 }
 273                 if (!(dst_metric_locked(dst, RTAX_ADVMSS))) {
 274                         u32 mss = mtu - DN_MAX_NSP_DATA_HEADER;
 275                         u32 existing_mss = dst_metric_raw(dst, RTAX_ADVMSS);
 276                         if (!existing_mss || existing_mss > mss)
 277                                 dst_metric_set(dst, RTAX_ADVMSS, mss);
 278                 }
 279         }
 280 }
 281
 282 static void dn_dst_redirect(struct dst_entry *dst, struct sock *sk,
 283                             struct sk_buff *skb)
 284 {
 285 }
 286
 287 /*
 288  * When a route has been marked obsolete. (e.g. routing cache flush)
 289  */
 290 static struct dst_entry *dn_dst_check(struct dst_entry *dst, __u32 cookie)
 291 {
 292         return NULL;
 293 }
 294
 295 static struct dst_entry *dn_dst_negative_advice(struct dst_entry *dst)
 296 {
 297         dst_release(dst);
 298         return NULL;
 299 }
 300
 301 static void dn_dst_link_failure(struct sk_buff *skb)
 302 {
 303 }
 304
 305 static inline int compare_keys(struct flowidn *fl1, struct flowidn *fl2)
 306 {
 307         return ((fl1->daddr ^ fl2->daddr) |
 308                 (fl1->saddr ^ fl2->saddr) |
 309                 (fl1->flowidn_mark ^ fl2->flowidn_mark) |
 310                 (fl1->flowidn_scope ^ fl2->flowidn_scope) |
 311                 (fl1->flowidn_oif ^ fl2->flowidn_oif) |
 312                 (fl1->flowidn_iif ^ fl2->flowidn_iif)) == 0;
 313 }
 314
 315 static int dn_insert_route(struct dn_route *rt, unsigned int hash, struct dn_route **rp)
 316 {
 317         struct dn_route *rth;
 318         struct dn_route __rcu **rthp;
 319         unsigned long now = jiffies;
 320
 321         rthp = &dn_rt_hash_table[hash].chain;
 322
 323         spin_lock_bh(&dn_rt_hash_table[hash].lock);
 324         while ((rth = rcu_dereference_protected(*rthp,
 325                                                 lockdep_is_held(&dn_rt_hash_table[hash].lock))) != NULL) {
 326                 if (compare_keys(&rth->fld, &rt->fld)) {
 327                         /* Put it first */
 328                         *rthp = rth->dn_next;
 329                         rcu_assign_pointer(rth->dn_next,
 330                                            dn_rt_hash_table[hash].chain);
 331                         rcu_assign_pointer(dn_rt_hash_table[hash].chain, rth);
 332
 333                         dst_hold_and_use(&rth->dst, now);
 334                         spin_unlock_bh(&dn_rt_hash_table[hash].lock);
 335
 336                         dst_release_immediate(&rt->dst);
 337                         *rp = rth;
 338                         return 0;
 339                 }
 340                 rthp = &rth->dn_next;
 341         }
 342
 343         rcu_assign_pointer(rt->dn_next, dn_rt_hash_table[hash].chain);
 344         rcu_assign_pointer(dn_rt_hash_table[hash].chain, rt);
 345
 346         dst_hold_and_use(&rt->dst, now);
 347         spin_unlock_bh(&dn_rt_hash_table[hash].lock);
 348         *rp = rt;
 349         return 0;
 350 }
 351
 352 static void dn_run_flush(struct timer_list *unused)
 353 {
 354         int i;
 355         struct dn_route *rt, *next;
 356
 357         for (i = 0; i < dn_rt_hash_mask; i++) {
 358                 spin_lock_bh(&dn_rt_hash_table[i].lock);
 359
 360                 if ((rt = xchg((struct dn_route **)&dn_rt_hash_table[i].chain, NULL)) == NULL)
 361                         goto nothing_to_declare;
 362
 363                 for(; rt; rt = next) {
 364                         next = rcu_dereference_raw(rt->dn_next);
 365                         RCU_INIT_POINTER(rt->dn_next, NULL);
 366                         dst_dev_put(&rt->dst);
 367                         dst_release(&rt->dst);
 368                 }
 369
 370 nothing_to_declare:
 371                 spin_unlock_bh(&dn_rt_hash_table[i].lock);
 372         }
 373 }
 374
 375 static DEFINE_SPINLOCK(dn_rt_flush_lock);
 376
 377 void dn_rt_cache_flush(int delay)
 378 {
 379         unsigned long now = jiffies;
 380         int user_mode = !in_interrupt();
 381
 382         if (delay < 0)
 383                 delay = dn_rt_min_delay;
 384
 385         spin_lock_bh(&dn_rt_flush_lock);
 386
 387         if (del_timer(&dn_rt_flush_timer) && delay > 0 && dn_rt_deadline) {
 388                 long tmo = (long)(dn_rt_deadline - now);
 389
 390                 if (user_mode && tmo < dn_rt_max_delay - dn_rt_min_delay)
 391                         tmo = 0;
 392
 393                 if (delay > tmo)
 394                         delay = tmo;
 395         }
 396
 397         if (delay <= 0) {
 398                 spin_unlock_bh(&dn_rt_flush_lock);
 399                 dn_run_flush(NULL);
 400                 return;
 401         }
 402
 403         if (dn_rt_deadline == 0)
 404                 dn_rt_deadline = now + dn_rt_max_delay;
 405
 406         dn_rt_flush_timer.expires = now + delay;
 407         add_timer(&dn_rt_flush_timer);
 408         spin_unlock_bh(&dn_rt_flush_lock);
 409 }
 410
 411 /**
 412  * dn_return_short - Return a short packet to its sender
 413  * @skb: The packet to return
 414  *
 415  */
 416 static int dn_return_short(struct sk_buff *skb)
 417 {
 418         struct dn_skb_cb *cb;
 419         unsigned char *ptr;
 420         __le16 *src;
 421         __le16 *dst;
 422
 423         /* Add back headers */
 424         skb_push(skb, skb->data - skb_network_header(skb));
 425
 426         if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
 427                 return NET_RX_DROP;
 428
 429         cb = DN_SKB_CB(skb);
 430         /* Skip packet length and point to flags */
 431         ptr = skb->data + 2;
 432         *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
 433
 434         dst = (__le16 *)ptr;
 435         ptr += 2;
 436         src = (__le16 *)ptr;
 437         ptr += 2;
 438         *ptr = 0; /* Zero hop count */
 439
 440         swap(*src, *dst);
 441
 442         skb->pkt_type = PACKET_OUTGOING;
 443         dn_rt_finish_output(skb, NULL, NULL);
 444         return NET_RX_SUCCESS;
 445 }
 446
 447 /**
 448  * dn_return_long - Return a long packet to its sender
 449  * @skb: The long format packet to return
 450  *
 451  */
 452 static int dn_return_long(struct sk_buff *skb)
 453 {
 454         struct dn_skb_cb *cb;
 455         unsigned char *ptr;
 456         unsigned char *src_addr, *dst_addr;
 457         unsigned char tmp[ETH_ALEN];
 458
 459         /* Add back all headers */
 460         skb_push(skb, skb->data - skb_network_header(skb));
 461
 462         if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
 463                 return NET_RX_DROP;
 464
 465         cb = DN_SKB_CB(skb);
 466         /* Ignore packet length and point to flags */
 467         ptr = skb->data + 2;
 468
 469         /* Skip padding */
 470         if (*ptr & DN_RT_F_PF) {
 471                 char padlen = (*ptr & ~DN_RT_F_PF);
 472                 ptr += padlen;
 473         }
 474
 475         *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
 476         ptr += 2;
 477         dst_addr = ptr;
 478         ptr += 8;
 479         src_addr = ptr;
 480         ptr += 6;
 481         *ptr = 0; /* Zero hop count */
 482
 483         /* Swap source and destination */
 484         memcpy(tmp, src_addr, ETH_ALEN);
 485         memcpy(src_addr, dst_addr, ETH_ALEN);
 486         memcpy(dst_addr, tmp, ETH_ALEN);
 487
 488         skb->pkt_type = PACKET_OUTGOING;
 489         dn_rt_finish_output(skb, dst_addr, src_addr);
 490         return NET_RX_SUCCESS;
 491 }
 492
 493 /**
 494  * dn_route_rx_packet - Try and find a route for an incoming packet
 495  * @skb: The packet to find a route for
 496  *
 497  * Returns: result of input function if route is found, error code otherwise
 498  */
 499 static int dn_route_rx_packet(struct net *net, struct sock *sk, struct sk_buff *skb)
 500 {
 501         struct dn_skb_cb *cb;
 502         int err;
 503
 504         if ((err = dn_route_input(skb)) == 0)
 505                 return dst_input(skb);
 506
 507         cb = DN_SKB_CB(skb);
 508         if (decnet_debug_level & 4) {
 509                 char *devname = skb->dev ? skb->dev->name : "???";
 510
 511                 printk(KERN_DEBUG
 512                         "DECnet: dn_route_rx_packet: rt_flags=0x%02x dev=%s len=%d src=0x%04hx dst=0x%04hx err=%d type=%d\n",
 513                         (int)cb->rt_flags, devname, skb->len,
 514                         le16_to_cpu(cb->src), le16_to_cpu(cb->dst),
 515                         err, skb->pkt_type);
 516         }
 517
 518         if ((skb->pkt_type == PACKET_HOST) && (cb->rt_flags & DN_RT_F_RQR)) {
 519                 switch (cb->rt_flags & DN_RT_PKT_MSK) {
 520                 case DN_RT_PKT_SHORT:
 521                         return dn_return_short(skb);
 522                 case DN_RT_PKT_LONG:
 523                         return dn_return_long(skb);
 524                 }
 525         }
 526
 527         kfree_skb(skb);
 528         return NET_RX_DROP;
 529 }
 530
 531 static int dn_route_rx_long(struct sk_buff *skb)
 532 {
 533         struct dn_skb_cb *cb = DN_SKB_CB(skb);
 534         unsigned char *ptr = skb->data;
 535
 536         if (!pskb_may_pull(skb, 21)) /* 20 for long header, 1 for shortest nsp */
 537                 goto drop_it;
 538
 539         skb_pull(skb, 20);
 540         skb_reset_transport_header(skb);
 541
 542         /* Destination info */
 543         ptr += 2;
 544         cb->dst = dn_eth2dn(ptr);
 545         if (memcmp(ptr, dn_hiord_addr, 4) != 0)
 546                 goto drop_it;
 547         ptr += 6;
 548
 549
 550         /* Source info */
 551         ptr += 2;
 552         cb->src = dn_eth2dn(ptr);
 553         if (memcmp(ptr, dn_hiord_addr, 4) != 0)
 554                 goto drop_it;
 555         ptr += 6;
 556         /* Other junk */
 557         ptr++;
 558         cb->hops = *ptr++; /* Visit Count */
 559
 560         return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING,
 561                        &init_net, NULL, skb, skb->dev, NULL,
 562                        dn_route_rx_packet);
 563
 564 drop_it:
 565         kfree_skb(skb);
 566         return NET_RX_DROP;
 567 }
 568
 569
 570
 571 static int dn_route_rx_short(struct sk_buff *skb)
 572 {
 573         struct dn_skb_cb *cb = DN_SKB_CB(skb);
 574         unsigned char *ptr = skb->data;
 575
 576         if (!pskb_may_pull(skb, 6)) /* 5 for short header + 1 for shortest nsp */
 577                 goto drop_it;
 578
 579         skb_pull(skb, 5);
 580         skb_reset_transport_header(skb);
 581
 582         cb->dst = *(__le16 *)ptr;
 583         ptr += 2;
 584         cb->src = *(__le16 *)ptr;
 585         ptr += 2;
 586         cb->hops = *ptr & 0x3f;
 587
 588         return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING,
 589                        &init_net, NULL, skb, skb->dev, NULL,
 590                        dn_route_rx_packet);
 591
 592 drop_it:
 593         kfree_skb(skb);
 594         return NET_RX_DROP;
 595 }
 596
 597 static int dn_route_discard(struct net *net, struct sock *sk, struct sk_buff *skb)
 598 {
 599         /*
 600          * I know we drop the packet here, but thats considered success in
 601          * this case
 602          */
 603         kfree_skb(skb);
 604         return NET_RX_SUCCESS;
 605 }
 606
 607 static int dn_route_ptp_hello(struct net *net, struct sock *sk, struct sk_buff *skb)
 608 {
 609         dn_dev_hello(skb);
 610         dn_neigh_pointopoint_hello(skb);
 611         return NET_RX_SUCCESS;
 612 }
 613
 614 int dn_route_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
 615 {
 616         struct dn_skb_cb *cb;
 617         unsigned char flags = 0;
 618         __u16 len = le16_to_cpu(*(__le16 *)skb->data);
 619         struct dn_dev *dn = rcu_dereference(dev->dn_ptr);
 620         unsigned char padlen = 0;
 621
 622         if (!net_eq(dev_net(dev), &init_net))
 623                 goto dump_it;
 624
 625         if (dn == NULL)
 626                 goto dump_it;
 627
 628         if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
 629                 goto out;
 630
 631         if (!pskb_may_pull(skb, 3))
 632                 goto dump_it;
 633
 634         skb_pull(skb, 2);
 635
 636         if (len > skb->len)
 637                 goto dump_it;
 638
 639         skb_trim(skb, len);
 640
 641         flags = *skb->data;
 642
 643         cb = DN_SKB_CB(skb);
 644         cb->stamp = jiffies;
 645         cb->iif = dev->ifindex;
 646
 647         /*
 648          * If we have padding, remove it.
 649          */
 650         if (flags & DN_RT_F_PF) {
 651                 padlen = flags & ~DN_RT_F_PF;
 652                 if (!pskb_may_pull(skb, padlen + 1))
 653                         goto dump_it;
 654                 skb_pull(skb, padlen);
 655                 flags = *skb->data;
 656         }
 657
 658         skb_reset_network_header(skb);
 659
 660         /*
 661          * Weed out future version DECnet
 662          */
 663         if (flags & DN_RT_F_VER)
 664                 goto dump_it;
 665
 666         cb->rt_flags = flags;
 667
 668         if (decnet_debug_level & 1)
 669                 printk(KERN_DEBUG
 670                         "dn_route_rcv: got 0x%02x from %s [%d %d %d]\n",
 671                         (int)flags, (dev) ? dev->name : "???", len, skb->len,
 672                         padlen);
 673
 674         if (flags & DN_RT_PKT_CNTL) {
 675                 if (unlikely(skb_linearize(skb)))
 676                         goto dump_it;
 677
 678                 switch (flags & DN_RT_CNTL_MSK) {
 679                 case DN_RT_PKT_INIT:
 680                         dn_dev_init_pkt(skb);
 681                         break;
 682                 case DN_RT_PKT_VERI:
 683                         dn_dev_veri_pkt(skb);
 684                         break;
 685                 }
 686
 687                 if (dn->parms.state != DN_DEV_S_RU)
 688                         goto dump_it;
 689
 690                 switch (flags & DN_RT_CNTL_MSK) {
 691                 case DN_RT_PKT_HELO:
 692                         return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
 693                                        &init_net, NULL, skb, skb->dev, NULL,
 694                                        dn_route_ptp_hello);
 695
 696                 case DN_RT_PKT_L1RT:
 697                 case DN_RT_PKT_L2RT:
 698                         return NF_HOOK(NFPROTO_DECNET, NF_DN_ROUTE,
 699                                        &init_net, NULL, skb, skb->dev, NULL,
 700                                        dn_route_discard);
 701                 case DN_RT_PKT_ERTH:
 702                         return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
 703                                        &init_net, NULL, skb, skb->dev, NULL,
 704                                        dn_neigh_router_hello);
 705
 706                 case DN_RT_PKT_EEDH:
 707                         return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
 708                                        &init_net, NULL, skb, skb->dev, NULL,
 709                                        dn_neigh_endnode_hello);
 710                 }
 711         } else {
 712                 if (dn->parms.state != DN_DEV_S_RU)
 713                         goto dump_it;
 714
 715                 skb_pull(skb, 1); /* Pull flags */
 716
 717                 switch (flags & DN_RT_PKT_MSK) {
 718                 case DN_RT_PKT_LONG:
 719                         return dn_route_rx_long(skb);
 720                 case DN_RT_PKT_SHORT:
 721                         return dn_route_rx_short(skb);
 722                 }
 723         }
 724
 725 dump_it:
 726         kfree_skb(skb);
 727 out:
 728         return NET_RX_DROP;
 729 }
 730
 731 static int dn_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 732 {
 733         struct dst_entry *dst = skb_dst(skb);
 734         struct dn_route *rt = (struct dn_route *)dst;
 735         struct net_device *dev = dst->dev;
 736         struct dn_skb_cb *cb = DN_SKB_CB(skb);
 737
 738         int err = -EINVAL;
 739
 740         if (rt->n == NULL)
 741                 goto error;
 742
 743         skb->dev = dev;
 744
 745         cb->src = rt->rt_saddr;
 746         cb->dst = rt->rt_daddr;
 747
 748         /*
 749          * Always set the Intra-Ethernet bit on all outgoing packets
 750          * originated on this node. Only valid flag from upper layers
 751          * is return-to-sender-requested. Set hop count to 0 too.
 752          */
 753         cb->rt_flags &= ~DN_RT_F_RQR;
 754         cb->rt_flags |= DN_RT_F_IE;
 755         cb->hops = 0;
 756
 757         return NF_HOOK(NFPROTO_DECNET, NF_DN_LOCAL_OUT,
 758                        &init_net, sk, skb, NULL, dev,
 759                        dn_to_neigh_output);
 760
 761 error:
 762         net_dbg_ratelimited("dn_output: This should not happen\n");
 763
 764         kfree_skb(skb);
 765
 766         return err;
 767 }
 768
 769 static int dn_forward(struct sk_buff *skb)
 770 {
 771         struct dn_skb_cb *cb = DN_SKB_CB(skb);
 772         struct dst_entry *dst = skb_dst(skb);
 773         struct dn_dev *dn_db = rcu_dereference(dst->dev->dn_ptr);
 774         struct dn_route *rt;
 775         int header_len;
 776         struct net_device *dev = skb->dev;
 777
 778         if (skb->pkt_type != PACKET_HOST)
 779                 goto drop;
 780
 781         /* Ensure that we have enough space for headers */
 782         rt = (struct dn_route *)skb_dst(skb);
 783         header_len = dn_db->use_long ? 21 : 6;
 784         if (skb_cow(skb, LL_RESERVED_SPACE(rt->dst.dev)+header_len))
 785                 goto drop;
 786
 787         /*
 788          * Hop count exceeded.
 789          */
 790         if (++cb->hops > 30)
 791                 goto drop;
 792
 793         skb->dev = rt->dst.dev;
 794
 795         /*
 796          * If packet goes out same interface it came in on, then set
 797          * the Intra-Ethernet bit. This has no effect for short
 798          * packets, so we don't need to test for them here.
 799          */
 800         cb->rt_flags &= ~DN_RT_F_IE;
 801         if (rt->rt_flags & RTCF_DOREDIRECT)
 802                 cb->rt_flags |= DN_RT_F_IE;
 803
 804         return NF_HOOK(NFPROTO_DECNET, NF_DN_FORWARD,
 805                        &init_net, NULL, skb, dev, skb->dev,
 806                        dn_to_neigh_output);
 807
 808 drop:
 809         kfree_skb(skb);
 810         return NET_RX_DROP;
 811 }
 812
 813 /*
 814  * Used to catch bugs. This should never normally get
 815  * called.
 816  */
 817 static int dn_rt_bug_out(struct net *net, struct sock *sk, struct sk_buff *skb)
 818 {
 819         struct dn_skb_cb *cb = DN_SKB_CB(skb);
 820
 821         net_dbg_ratelimited("dn_rt_bug: skb from:%04x to:%04x\n",
 822                             le16_to_cpu(cb->src), le16_to_cpu(cb->dst));
 823
 824         kfree_skb(skb);
 825
 826         return NET_RX_DROP;
 827 }
 828
 829 static int dn_rt_bug(struct sk_buff *skb)
 830 {
 831         struct dn_skb_cb *cb = DN_SKB_CB(skb);
 832
 833         net_dbg_ratelimited("dn_rt_bug: skb from:%04x to:%04x\n",
 834                             le16_to_cpu(cb->src), le16_to_cpu(cb->dst));
 835
 836         kfree_skb(skb);
 837
 838         return NET_RX_DROP;
 839 }
 840
 841 static unsigned int dn_dst_default_advmss(const struct dst_entry *dst)
 842 {
 843         return dn_mss_from_pmtu(dst->dev, dst_mtu(dst));
 844 }
 845
 846 static unsigned int dn_dst_mtu(const struct dst_entry *dst)
 847 {
 848         unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
 849
 850         return mtu ? : dst->dev->mtu;
 851 }
 852
 853 static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst,
 854                                              struct sk_buff *skb,
 855                                              const void *daddr)
 856 {
 857         return __neigh_lookup_errno(&dn_neigh_table, daddr, dst->dev);
 858 }
 859
 860 static int dn_rt_set_next_hop(struct dn_route *rt, struct dn_fib_res *res)
 861 {
 862         struct dn_fib_info *fi = res->fi;
 863         struct net_device *dev = rt->dst.dev;
 864         unsigned int mss_metric;
 865         struct neighbour *n;
 866
 867         if (fi) {
 868                 if (DN_FIB_RES_GW(*res) &&
 869                     DN_FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
 870                         rt->rt_gateway = DN_FIB_RES_GW(*res);
 871                 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
 872         }
 873         rt->rt_type = res->type;
 874
 875         if (dev != NULL && rt->n == NULL) {
 876                 n = __neigh_lookup_errno(&dn_neigh_table, &rt->rt_gateway, dev);
 877                 if (IS_ERR(n))
 878                         return PTR_ERR(n);
 879                 rt->n = n;
 880         }
 881
 882         if (dst_metric(&rt->dst, RTAX_MTU) > rt->dst.dev->mtu)
 883                 dst_metric_set(&rt->dst, RTAX_MTU, rt->dst.dev->mtu);
 884         mss_metric = dst_metric_raw(&rt->dst, RTAX_ADVMSS);
 885         if (mss_metric) {
 886                 unsigned int mss = dn_mss_from_pmtu(dev, dst_mtu(&rt->dst));
 887                 if (mss_metric > mss)
 888                         dst_metric_set(&rt->dst, RTAX_ADVMSS, mss);
 889         }
 890         return 0;
 891 }
 892
 893 static inline int dn_match_addr(__le16 addr1, __le16 addr2)
 894 {
 895         __u16 tmp = le16_to_cpu(addr1) ^ le16_to_cpu(addr2);
 896         int match = 16;
 897         while(tmp) {
 898                 tmp >>= 1;
 899                 match--;
 900         }
 901         return match;
 902 }
 903
 904 static __le16 dnet_select_source(const struct net_device *dev, __le16 daddr, int scope)
 905 {
 906         __le16 saddr = 0;
 907         struct dn_dev *dn_db;
 908         struct dn_ifaddr *ifa;
 909         int best_match = 0;
 910         int ret;
 911
 912         rcu_read_lock();
 913         dn_db = rcu_dereference(dev->dn_ptr);
 914         for (ifa = rcu_dereference(dn_db->ifa_list);
 915              ifa != NULL;
 916              ifa = rcu_dereference(ifa->ifa_next)) {
 917                 if (ifa->ifa_scope > scope)
 918                         continue;
 919                 if (!daddr) {
 920                         saddr = ifa->ifa_local;
 921                         break;
 922                 }
 923                 ret = dn_match_addr(daddr, ifa->ifa_local);
 924                 if (ret > best_match)
 925                         saddr = ifa->ifa_local;
 926                 if (best_match == 0)
 927                         saddr = ifa->ifa_local;
 928         }
 929         rcu_read_unlock();
 930
 931         return saddr;
 932 }
 933
 934 static inline __le16 __dn_fib_res_prefsrc(struct dn_fib_res *res)
 935 {
 936         return dnet_select_source(DN_FIB_RES_DEV(*res), DN_FIB_RES_GW(*res), res->scope);
 937 }
 938
 939 static inline __le16 dn_fib_rules_map_destination(__le16 daddr, struct dn_fib_res *res)
 940 {
 941         __le16 mask = dnet_make_mask(res->prefixlen);
 942         return (daddr&~mask)|res->fi->fib_nh->nh_gw;
 943 }
 944
 945 static int dn_route_output_slow(struct dst_entry **pprt, const struct flowidn *oldflp, int try_hard)
 946 {
 947         struct flowidn fld = {
 948                 .daddr = oldflp->daddr,
 949                 .saddr = oldflp->saddr,
 950                 .flowidn_scope = RT_SCOPE_UNIVERSE,
 951                 .flowidn_mark = oldflp->flowidn_mark,
 952                 .flowidn_iif = LOOPBACK_IFINDEX,
 953                 .flowidn_oif = oldflp->flowidn_oif,
 954         };
 955         struct dn_route *rt = NULL;
 956         struct net_device *dev_out = NULL, *dev;
 957         struct neighbour *neigh = NULL;
 958         unsigned int hash;
 959         unsigned int flags = 0;
 960         struct dn_fib_res res = { .fi = NULL, .type = RTN_UNICAST };
 961         int err;
 962         int free_res = 0;
 963         __le16 gateway = 0;
 964
 965         if (decnet_debug_level & 16)
 966                 printk(KERN_DEBUG
 967                        "dn_route_output_slow: dst=%04x src=%04x mark=%d"
 968                        " iif=%d oif=%d\n", le16_to_cpu(oldflp->daddr),
 969                        le16_to_cpu(oldflp->saddr),
 970                        oldflp->flowidn_mark, LOOPBACK_IFINDEX,
 971                        oldflp->flowidn_oif);
 972
 973         /* If we have an output interface, verify its a DECnet device */
 974         if (oldflp->flowidn_oif) {
 975                 dev_out = dev_get_by_index(&init_net, oldflp->flowidn_oif);
 976                 err = -ENODEV;
 977                 if (dev_out && dev_out->dn_ptr == NULL) {
 978                         dev_put(dev_out);
 979                         dev_out = NULL;
 980                 }
 981                 if (dev_out == NULL)
 982                         goto out;
 983         }
 984
 985         /* If we have a source address, verify that its a local address */
 986         if (oldflp->saddr) {
 987                 err = -EADDRNOTAVAIL;
 988
 989                 if (dev_out) {
 990                         if (dn_dev_islocal(dev_out, oldflp->saddr))
 991                                 goto source_ok;
 992                         dev_put(dev_out);
 993                         goto out;
 994                 }
 995                 rcu_read_lock();
 996                 for_each_netdev_rcu(&init_net, dev) {
 997                         if (!dev->dn_ptr)
 998                                 continue;
 999                         if (!dn_dev_islocal(dev, oldflp->saddr))
1000                                 continue;
1001                         if ((dev->flags & IFF_LOOPBACK) &&
1002                             oldflp->daddr &&
1003                             !dn_dev_islocal(dev, oldflp->daddr))
1004                                 continue;
1005
1006                         dev_out = dev;
1007                         break;
1008                 }
1009                 rcu_read_unlock();
1010                 if (dev_out == NULL)
1011                         goto out;
1012                 dev_hold(dev_out);
1013 source_ok:
1014                 ;
1015         }
1016
1017         /* No destination? Assume its local */
1018         if (!fld.daddr) {
1019                 fld.daddr = fld.saddr;
1020
1021                 if (dev_out)
1022                         dev_put(dev_out);
1023                 err = -EINVAL;
1024                 dev_out = init_net.loopback_dev;
1025                 if (!dev_out->dn_ptr)
1026                         goto out;
1027                 err = -EADDRNOTAVAIL;
1028                 dev_hold(dev_out);
1029                 if (!fld.daddr) {
1030                         fld.daddr =
1031                         fld.saddr = dnet_select_source(dev_out, 0,
1032                                                        RT_SCOPE_HOST);
1033                         if (!fld.daddr)
1034                                 goto out;
1035                 }
1036                 fld.flowidn_oif = LOOPBACK_IFINDEX;
1037                 res.type = RTN_LOCAL;
1038                 goto make_route;
1039         }
1040
1041         if (decnet_debug_level & 16)
1042                 printk(KERN_DEBUG
1043                        "dn_route_output_slow: initial checks complete."
1044                        " dst=%04x src=%04x oif=%d try_hard=%d\n",
1045                        le16_to_cpu(fld.daddr), le16_to_cpu(fld.saddr),
1046                        fld.flowidn_oif, try_hard);
1047
1048         /*
1049          * N.B. If the kernel is compiled without router support then
1050          * dn_fib_lookup() will evaluate to non-zero so this if () block
1051          * will always be executed.
1052          */
1053         err = -ESRCH;
1054         if (try_hard || (err = dn_fib_lookup(&fld, &res)) != 0) {
1055                 struct dn_dev *dn_db;
1056                 if (err != -ESRCH)
1057                         goto out;
1058                 /*
1059                  * Here the fallback is basically the standard algorithm for
1060                  * routing in endnodes which is described in the DECnet routing
1061                  * docs
1062                  *
1063                  * If we are not trying hard, look in neighbour cache.
1064                  * The result is tested to ensure that if a specific output
1065                  * device/source address was requested, then we honour that
1066                  * here
1067                  */
1068                 if (!try_hard) {
1069                         neigh = neigh_lookup_nodev(&dn_neigh_table, &init_net, &fld.daddr);
1070                         if (neigh) {
1071                                 if ((oldflp->flowidn_oif &&
1072                                     (neigh->dev->ifindex != oldflp->flowidn_oif)) ||
1073                                     (oldflp->saddr &&
1074                                     (!dn_dev_islocal(neigh->dev,
1075                                                      oldflp->saddr)))) {
1076                                         neigh_release(neigh);
1077                                         neigh = NULL;
1078                                 } else {
1079                                         if (dev_out)
1080                                                 dev_put(dev_out);
1081                                         if (dn_dev_islocal(neigh->dev, fld.daddr)) {
1082                                                 dev_out = init_net.loopback_dev;
1083                                                 res.type = RTN_LOCAL;
1084                                         } else {
1085                                                 dev_out = neigh->dev;
1086                                         }
1087                                         dev_hold(dev_out);
1088                                         goto select_source;
1089                                 }
1090                         }
1091                 }
1092
1093                 /* Not there? Perhaps its a local address */
1094                 if (dev_out == NULL)
1095                         dev_out = dn_dev_get_default();
1096                 err = -ENODEV;
1097                 if (dev_out == NULL)
1098                         goto out;
1099                 dn_db = rcu_dereference_raw(dev_out->dn_ptr);
1100                 if (!dn_db)
1101                         goto e_inval;
1102                 /* Possible improvement - check all devices for local addr */
1103                 if (dn_dev_islocal(dev_out, fld.daddr)) {
1104                         dev_put(dev_out);
1105                         dev_out = init_net.loopback_dev;
1106                         dev_hold(dev_out);
1107                         res.type = RTN_LOCAL;
1108                         goto select_source;
1109                 }
1110                 /* Not local either.... try sending it to the default router */
1111                 neigh = neigh_clone(dn_db->router);
1112                 BUG_ON(neigh && neigh->dev != dev_out);
1113
1114                 /* Ok then, we assume its directly connected and move on */
1115 select_source:
1116                 if (neigh)
1117                         gateway = ((struct dn_neigh *)neigh)->addr;
1118                 if (gateway == 0)
1119                         gateway = fld.daddr;
1120                 if (fld.saddr == 0) {
1121                         fld.saddr = dnet_select_source(dev_out, gateway,
1122                                                        res.type == RTN_LOCAL ?
1123                                                        RT_SCOPE_HOST :
1124                                                        RT_SCOPE_LINK);
1125                         if (fld.saddr == 0 && res.type != RTN_LOCAL)
1126                                 goto e_addr;
1127                 }
1128                 fld.flowidn_oif = dev_out->ifindex;
1129                 goto make_route;
1130         }
1131         free_res = 1;
1132
1133         if (res.type == RTN_NAT)
1134                 goto e_inval;
1135
1136         if (res.type == RTN_LOCAL) {
1137                 if (!fld.saddr)
1138                         fld.saddr = fld.daddr;
1139                 if (dev_out)
1140                         dev_put(dev_out);
1141                 dev_out = init_net.loopback_dev;
1142                 dev_hold(dev_out);
1143                 if (!dev_out->dn_ptr)
1144                         goto e_inval;
1145                 fld.flowidn_oif = dev_out->ifindex;
1146                 if (res.fi)
1147                         dn_fib_info_put(res.fi);
1148                 res.fi = NULL;
1149                 goto make_route;
1150         }
1151
1152         if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1153                 dn_fib_select_multipath(&fld, &res);
1154
1155         /*
1156          * We could add some logic to deal with default routes here and
1157          * get rid of some of the special casing above.
1158          */
1159
1160         if (!fld.saddr)
1161                 fld.saddr = DN_FIB_RES_PREFSRC(res);
1162
1163         if (dev_out)
1164                 dev_put(dev_out);
1165         dev_out = DN_FIB_RES_DEV(res);
1166         dev_hold(dev_out);
1167         fld.flowidn_oif = dev_out->ifindex;
1168         gateway = DN_FIB_RES_GW(res);
1169
1170 make_route:
1171         if (dev_out->flags & IFF_LOOPBACK)
1172                 flags |= RTCF_LOCAL;
1173
1174         rt = dst_alloc(&dn_dst_ops, dev_out, 0, DST_OBSOLETE_NONE, DST_HOST);
1175         if (rt == NULL)
1176                 goto e_nobufs;
1177
1178         rt->dn_next = NULL;
1179         memset(&rt->fld, 0, sizeof(rt->fld));
1180         rt->fld.saddr        = oldflp->saddr;
1181         rt->fld.daddr        = oldflp->daddr;
1182         rt->fld.flowidn_oif  = oldflp->flowidn_oif;
1183         rt->fld.flowidn_iif  = 0;
1184         rt->fld.flowidn_mark = oldflp->flowidn_mark;
1185
1186         rt->rt_saddr      = fld.saddr;
1187         rt->rt_daddr      = fld.daddr;
1188         rt->rt_gateway    = gateway ? gateway : fld.daddr;
1189         rt->rt_local_src  = fld.saddr;
1190
1191         rt->rt_dst_map    = fld.daddr;
1192         rt->rt_src_map    = fld.saddr;
1193
1194         rt->n = neigh;
1195         neigh = NULL;
1196
1197         rt->dst.lastuse = jiffies;
1198         rt->dst.output  = dn_output;
1199         rt->dst.input   = dn_rt_bug;
1200         rt->rt_flags      = flags;
1201         if (flags & RTCF_LOCAL)
1202                 rt->dst.input = dn_nsp_rx;
1203
1204         err = dn_rt_set_next_hop(rt, &res);
1205         if (err)
1206                 goto e_neighbour;
1207
1208         hash = dn_hash(rt->fld.saddr, rt->fld.daddr);
1209         /* dn_insert_route() increments dst->__refcnt */
1210         dn_insert_route(rt, hash, (struct dn_route **)pprt);
1211
1212 done:
1213         if (neigh)
1214                 neigh_release(neigh);
1215         if (free_res)
1216                 dn_fib_res_put(&res);
1217         if (dev_out)
1218                 dev_put(dev_out);
1219 out:
1220         return err;
1221
1222 e_addr:
1223         err = -EADDRNOTAVAIL;
1224         goto done;
1225 e_inval:
1226         err = -EINVAL;
1227         goto done;
1228 e_nobufs:
1229         err = -ENOBUFS;
1230         goto done;
1231 e_neighbour:
1232         dst_release_immediate(&rt->dst);
1233         goto e_nobufs;
1234 }
1235
1236
1237 /*
1238  * N.B. The flags may be moved into the flowi at some future stage.
1239  */
1240 static int __dn_route_output_key(struct dst_entry **pprt, const struct flowidn *flp, int flags)
1241 {
1242         unsigned int hash = dn_hash(flp->saddr, flp->daddr);
1243         struct dn_route *rt = NULL;
1244
1245         if (!(flags & MSG_TRYHARD)) {
1246                 rcu_read_lock_bh();
1247                 for (rt = rcu_dereference_bh(dn_rt_hash_table[hash].chain); rt;
1248                         rt = rcu_dereference_bh(rt->dn_next)) {
1249                         if ((flp->daddr == rt->fld.daddr) &&
1250                             (flp->saddr == rt->fld.saddr) &&
1251                             (flp->flowidn_mark == rt->fld.flowidn_mark) &&
1252                             dn_is_output_route(rt) &&
1253                             (rt->fld.flowidn_oif == flp->flowidn_oif)) {
1254                                 dst_hold_and_use(&rt->dst, jiffies);
1255                                 rcu_read_unlock_bh();
1256                                 *pprt = &rt->dst;
1257                                 return 0;
1258                         }
1259                 }
1260                 rcu_read_unlock_bh();
1261         }
1262
1263         return dn_route_output_slow(pprt, flp, flags);
1264 }
1265
1266 static int dn_route_output_key(struct dst_entry **pprt, struct flowidn *flp, int flags)
1267 {
1268         int err;
1269
1270         err = __dn_route_output_key(pprt, flp, flags);
1271         if (err == 0 && flp->flowidn_proto) {
1272                 *pprt = xfrm_lookup(&init_net, *pprt,
1273                                     flowidn_to_flowi(flp), NULL, 0);
1274                 if (IS_ERR(*pprt)) {
1275                         err = PTR_ERR(*pprt);
1276                         *pprt = NULL;
1277                 }
1278         }
1279         return err;
1280 }
1281
1282 int dn_route_output_sock(struct dst_entry __rcu **pprt, struct flowidn *fl, struct sock *sk, int flags)
1283 {
1284         int err;
1285
1286         err = __dn_route_output_key(pprt, fl, flags & MSG_TRYHARD);
1287         if (err == 0 && fl->flowidn_proto) {
1288                 *pprt = xfrm_lookup(&init_net, *pprt,
1289                                     flowidn_to_flowi(fl), sk, 0);
1290                 if (IS_ERR(*pprt)) {
1291                         err = PTR_ERR(*pprt);
1292                         *pprt = NULL;
1293                 }
1294         }
1295         return err;
1296 }
1297
1298 static int dn_route_input_slow(struct sk_buff *skb)
1299 {
1300         struct dn_route *rt = NULL;
1301         struct dn_skb_cb *cb = DN_SKB_CB(skb);
1302         struct net_device *in_dev = skb->dev;
1303         struct net_device *out_dev = NULL;
1304         struct dn_dev *dn_db;
1305         struct neighbour *neigh = NULL;
1306         unsigned int hash;
1307         int flags = 0;
1308         __le16 gateway = 0;
1309         __le16 local_src = 0;
1310         struct flowidn fld = {
1311                 .daddr = cb->dst,
1312                 .saddr = cb->src,
1313                 .flowidn_scope = RT_SCOPE_UNIVERSE,
1314                 .flowidn_mark = skb->mark,
1315                 .flowidn_iif = skb->dev->ifindex,
1316         };
1317         struct dn_fib_res res = { .fi = NULL, .type = RTN_UNREACHABLE };
1318         int err = -EINVAL;
1319         int free_res = 0;
1320
1321         dev_hold(in_dev);
1322
1323         if ((dn_db = rcu_dereference(in_dev->dn_ptr)) == NULL)
1324                 goto out;
1325
1326         /* Zero source addresses are not allowed */
1327         if (fld.saddr == 0)
1328                 goto out;
1329
1330         /*
1331          * In this case we've just received a packet from a source
1332          * outside ourselves pretending to come from us. We don't
1333          * allow it any further to prevent routing loops, spoofing and
1334          * other nasties. Loopback packets already have the dst attached
1335          * so this only affects packets which have originated elsewhere.
1336          */
1337         err  = -ENOTUNIQ;
1338         if (dn_dev_islocal(in_dev, cb->src))
1339                 goto out;
1340
1341         err = dn_fib_lookup(&fld, &res);
1342         if (err) {
1343                 if (err != -ESRCH)
1344                         goto out;
1345                 /*
1346                  * Is the destination us ?
1347                  */
1348                 if (!dn_dev_islocal(in_dev, cb->dst))
1349                         goto e_inval;
1350
1351                 res.type = RTN_LOCAL;
1352         } else {
1353                 __le16 src_map = fld.saddr;
1354                 free_res = 1;
1355
1356                 out_dev = DN_FIB_RES_DEV(res);
1357                 if (out_dev == NULL) {
1358                         net_crit_ratelimited("Bug in dn_route_input_slow() No output device\n");
1359                         goto e_inval;
1360                 }
1361                 dev_hold(out_dev);
1362
1363                 if (res.r)
1364                         src_map = fld.saddr; /* no NAT support for now */
1365
1366                 gateway = DN_FIB_RES_GW(res);
1367                 if (res.type == RTN_NAT) {
1368                         fld.daddr = dn_fib_rules_map_destination(fld.daddr, &res);
1369                         dn_fib_res_put(&res);
1370                         free_res = 0;
1371                         if (dn_fib_lookup(&fld, &res))
1372                                 goto e_inval;
1373                         free_res = 1;
1374                         if (res.type != RTN_UNICAST)
1375                                 goto e_inval;
1376                         flags |= RTCF_DNAT;
1377                         gateway = fld.daddr;
1378                 }
1379                 fld.saddr = src_map;
1380         }
1381
1382         switch(res.type) {
1383         case RTN_UNICAST:
1384                 /*
1385                  * Forwarding check here, we only check for forwarding
1386                  * being turned off, if you want to only forward intra
1387                  * area, its up to you to set the routing tables up
1388                  * correctly.
1389                  */
1390                 if (dn_db->parms.forwarding == 0)
1391                         goto e_inval;
1392
1393                 if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1394                         dn_fib_select_multipath(&fld, &res);
1395
1396                 /*
1397                  * Check for out_dev == in_dev. We use the RTCF_DOREDIRECT
1398                  * flag as a hint to set the intra-ethernet bit when
1399                  * forwarding. If we've got NAT in operation, we don't do
1400                  * this optimisation.
1401                  */
1402                 if (out_dev == in_dev && !(flags & RTCF_NAT))
1403                         flags |= RTCF_DOREDIRECT;
1404
1405                 local_src = DN_FIB_RES_PREFSRC(res);
1406
1407         case RTN_BLACKHOLE:
1408         case RTN_UNREACHABLE:
1409                 break;
1410         case RTN_LOCAL:
1411                 flags |= RTCF_LOCAL;
1412                 fld.saddr = cb->dst;
1413                 fld.daddr = cb->src;
1414
1415                 /* Routing tables gave us a gateway */
1416                 if (gateway)
1417                         goto make_route;
1418
1419                 /* Packet was intra-ethernet, so we know its on-link */
1420                 if (cb->rt_flags & DN_RT_F_IE) {
1421                         gateway = cb->src;
1422                         goto make_route;
1423                 }
1424
1425                 /* Use the default router if there is one */
1426                 neigh = neigh_clone(dn_db->router);
1427                 if (neigh) {
1428                         gateway = ((struct dn_neigh *)neigh)->addr;
1429                         goto make_route;
1430                 }
1431
1432                 /* Close eyes and pray */
1433                 gateway = cb->src;
1434                 goto make_route;
1435         default:
1436                 goto e_inval;
1437         }
1438
1439 make_route:
1440         rt = dst_alloc(&dn_dst_ops, out_dev, 1, DST_OBSOLETE_NONE, DST_HOST);
1441         if (rt == NULL)
1442                 goto e_nobufs;
1443
1444         rt->dn_next = NULL;
1445         memset(&rt->fld, 0, sizeof(rt->fld));
1446         rt->rt_saddr      = fld.saddr;
1447         rt->rt_daddr      = fld.daddr;
1448         rt->rt_gateway    = fld.daddr;
1449         if (gateway)
1450                 rt->rt_gateway = gateway;
1451         rt->rt_local_src  = local_src ? local_src : rt->rt_saddr;
1452
1453         rt->rt_dst_map    = fld.daddr;
1454         rt->rt_src_map    = fld.saddr;
1455
1456         rt->fld.saddr        = cb->src;
1457         rt->fld.daddr        = cb->dst;
1458         rt->fld.flowidn_oif  = 0;
1459         rt->fld.flowidn_iif  = in_dev->ifindex;
1460         rt->fld.flowidn_mark = fld.flowidn_mark;
1461
1462         rt->n = neigh;
1463         rt->dst.lastuse = jiffies;
1464         rt->dst.output = dn_rt_bug_out;
1465         switch (res.type) {
1466         case RTN_UNICAST:
1467                 rt->dst.input = dn_forward;
1468                 break;
1469         case RTN_LOCAL:
1470                 rt->dst.output = dn_output;
1471                 rt->dst.input = dn_nsp_rx;
1472                 rt->dst.dev = in_dev;
1473                 flags |= RTCF_LOCAL;
1474                 break;
1475         default:
1476         case RTN_UNREACHABLE:
1477         case RTN_BLACKHOLE:
1478                 rt->dst.input = dst_discard;
1479         }
1480         rt->rt_flags = flags;
1481
1482         err = dn_rt_set_next_hop(rt, &res);
1483         if (err)
1484                 goto e_neighbour;
1485
1486         hash = dn_hash(rt->fld.saddr, rt->fld.daddr);
1487         /* dn_insert_route() increments dst->__refcnt */
1488         dn_insert_route(rt, hash, &rt);
1489         skb_dst_set(skb, &rt->dst);
1490
1491 done:
1492         if (neigh)
1493                 neigh_release(neigh);
1494         if (free_res)
1495                 dn_fib_res_put(&res);
1496         dev_put(in_dev);
1497         if (out_dev)
1498                 dev_put(out_dev);
1499 out:
1500         return err;
1501
1502 e_inval:
1503         err = -EINVAL;
1504         goto done;
1505
1506 e_nobufs:
1507         err = -ENOBUFS;
1508         goto done;
1509
1510 e_neighbour:
1511         dst_release_immediate(&rt->dst);
1512         goto done;
1513 }
1514
1515 static int dn_route_input(struct sk_buff *skb)
1516 {
1517         struct dn_route *rt;
1518         struct dn_skb_cb *cb = DN_SKB_CB(skb);
1519         unsigned int hash = dn_hash(cb->src, cb->dst);
1520
1521         if (skb_dst(skb))
1522                 return 0;
1523
1524         rcu_read_lock();
1525         for(rt = rcu_dereference(dn_rt_hash_table[hash].chain); rt != NULL;
1526             rt = rcu_dereference(rt->dn_next)) {
1527                 if ((rt->fld.saddr == cb->src) &&
1528                     (rt->fld.daddr == cb->dst) &&
1529                     (rt->fld.flowidn_oif == 0) &&
1530                     (rt->fld.flowidn_mark == skb->mark) &&
1531                     (rt->fld.flowidn_iif == cb->iif)) {
1532                         dst_hold_and_use(&rt->dst, jiffies);
1533                         rcu_read_unlock();
1534                         skb_dst_set(skb, (struct dst_entry *)rt);
1535                         return 0;
1536                 }
1537         }
1538         rcu_read_unlock();
1539
1540         return dn_route_input_slow(skb);
1541 }
1542
1543 static int dn_rt_fill_info(struct sk_buff *skb, u32 portid, u32 seq,
1544                            int event, int nowait, unsigned int flags)
1545 {
1546         struct dn_route *rt = (struct dn_route *)skb_dst(skb);
1547         struct rtmsg *r;
1548         struct nlmsghdr *nlh;
1549         long expires;
1550
1551         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
1552         if (!nlh)
1553                 return -EMSGSIZE;
1554
1555         r = nlmsg_data(nlh);
1556         r->rtm_family = AF_DECnet;
1557         r->rtm_dst_len = 16;
1558         r->rtm_src_len = 0;
1559         r->rtm_tos = 0;
1560         r->rtm_table = RT_TABLE_MAIN;
1561         r->rtm_type = rt->rt_type;
1562         r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
1563         r->rtm_scope = RT_SCOPE_UNIVERSE;
1564         r->rtm_protocol = RTPROT_UNSPEC;
1565
1566         if (rt->rt_flags & RTCF_NOTIFY)
1567                 r->rtm_flags |= RTM_F_NOTIFY;
1568
1569         if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN) < 0 ||
1570             nla_put_le16(skb, RTA_DST, rt->rt_daddr) < 0)
1571                 goto errout;
1572
1573         if (rt->fld.saddr) {
1574                 r->rtm_src_len = 16;
1575                 if (nla_put_le16(skb, RTA_SRC, rt->fld.saddr) < 0)
1576                         goto errout;
1577         }
1578         if (rt->dst.dev &&
1579             nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex) < 0)
1580                 goto errout;
1581
1582         /*
1583          * Note to self - change this if input routes reverse direction when
1584          * they deal only with inputs and not with replies like they do
1585          * currently.
1586          */
1587         if (nla_put_le16(skb, RTA_PREFSRC, rt->rt_local_src) < 0)
1588                 goto errout;
1589
1590         if (rt->rt_daddr != rt->rt_gateway &&
1591             nla_put_le16(skb, RTA_GATEWAY, rt->rt_gateway) < 0)
1592                 goto errout;
1593
1594         if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
1595                 goto errout;
1596
1597         expires = rt->dst.expires ? rt->dst.expires - jiffies : 0;
1598         if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires,
1599                                rt->dst.error) < 0)
1600                 goto errout;
1601
1602         if (dn_is_input_route(rt) &&
1603             nla_put_u32(skb, RTA_IIF, rt->fld.flowidn_iif) < 0)
1604                 goto errout;
1605
1606         nlmsg_end(skb, nlh);
1607         return 0;
1608
1609 errout:
1610         nlmsg_cancel(skb, nlh);
1611         return -EMSGSIZE;
1612 }
1613
1614 const struct nla_policy rtm_dn_policy[RTA_MAX + 1] = {
1615         [RTA_DST]               = { .type = NLA_U16 },
1616         [RTA_SRC]               = { .type = NLA_U16 },
1617         [RTA_IIF]               = { .type = NLA_U32 },
1618         [RTA_OIF]               = { .type = NLA_U32 },
1619         [RTA_GATEWAY]           = { .type = NLA_U16 },
1620         [RTA_PRIORITY]          = { .type = NLA_U32 },
1621         [RTA_PREFSRC]           = { .type = NLA_U16 },
1622         [RTA_METRICS]           = { .type = NLA_NESTED },
1623         [RTA_MULTIPATH]         = { .type = NLA_NESTED },
1624         [RTA_TABLE]             = { .type = NLA_U32 },
1625         [RTA_MARK]              = { .type = NLA_U32 },
1626 };
1627
1628 /*
1629  * This is called by both endnodes and routers now.
1630  */
1631 static int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
1632                              struct netlink_ext_ack *extack)
1633 {
1634         struct net *net = sock_net(in_skb->sk);
1635         struct rtmsg *rtm = nlmsg_data(nlh);
1636         struct dn_route *rt = NULL;
1637         struct dn_skb_cb *cb;
1638         int err;
1639         struct sk_buff *skb;
1640         struct flowidn fld;
1641         struct nlattr *tb[RTA_MAX+1];
1642
1643         if (!net_eq(net, &init_net))
1644                 return -EINVAL;
1645
1646         err = nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
1647                                      rtm_dn_policy, extack);
1648         if (err < 0)
1649                 return err;
1650
1651         memset(&fld, 0, sizeof(fld));
1652         fld.flowidn_proto = DNPROTO_NSP;
1653
1654         skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1655         if (skb == NULL)
1656                 return -ENOBUFS;
1657         skb_reset_mac_header(skb);
1658         cb = DN_SKB_CB(skb);
1659
1660         if (tb[RTA_SRC])
1661                 fld.saddr = nla_get_le16(tb[RTA_SRC]);
1662
1663         if (tb[RTA_DST])
1664                 fld.daddr = nla_get_le16(tb[RTA_DST]);
1665
1666         if (tb[RTA_IIF])
1667                 fld.flowidn_iif = nla_get_u32(tb[RTA_IIF]);
1668
1669         if (fld.flowidn_iif) {
1670                 struct net_device *dev;
1671                 dev = __dev_get_by_index(&init_net, fld.flowidn_iif);
1672                 if (!dev || !dev->dn_ptr) {
1673                         kfree_skb(skb);
1674                         return -ENODEV;
1675                 }
1676                 skb->protocol = htons(ETH_P_DNA_RT);
1677                 skb->dev = dev;
1678                 cb->src = fld.saddr;
1679                 cb->dst = fld.daddr;
1680                 local_bh_disable();
1681                 err = dn_route_input(skb);
1682                 local_bh_enable();
1683                 memset(cb, 0, sizeof(struct dn_skb_cb));
1684                 rt = (struct dn_route *)skb_dst(skb);
1685                 if (!err && -rt->dst.error)
1686                         err = rt->dst.error;
1687         } else {
1688                 if (tb[RTA_OIF])
1689                         fld.flowidn_oif = nla_get_u32(tb[RTA_OIF]);
1690
1691                 err = dn_route_output_key((struct dst_entry **)&rt, &fld, 0);
1692         }
1693
1694         skb->dev = NULL;
1695         if (err)
1696                 goto out_free;
1697         skb_dst_set(skb, &rt->dst);
1698         if (rtm->rtm_flags & RTM_F_NOTIFY)
1699                 rt->rt_flags |= RTCF_NOTIFY;
1700
1701         err = dn_rt_fill_info(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, RTM_NEWROUTE, 0, 0);
1702         if (err < 0) {
1703                 err = -EMSGSIZE;
1704                 goto out_free;
1705         }
1706
1707         return rtnl_unicast(skb, &init_net, NETLINK_CB(in_skb).portid);
1708
1709 out_free:
1710         kfree_skb(skb);
1711         return err;
1712 }
1713
1714 /*
1715  * For routers, this is called from dn_fib_dump, but for endnodes its
1716  * called directly from the rtnetlink dispatch table.
1717  */
1718 int dn_cache_dump(struct sk_buff *skb, struct netlink_callback *cb)
1719 {
1720         struct net *net = sock_net(skb->sk);
1721         struct dn_route *rt;
1722         int h, s_h;
1723         int idx, s_idx;
1724         struct rtmsg *rtm;
1725
1726         if (!net_eq(net, &init_net))
1727                 return 0;
1728
1729         if (nlmsg_len(cb->nlh) < sizeof(struct rtmsg))
1730                 return -EINVAL;
1731
1732         rtm = nlmsg_data(cb->nlh);
1733         if (!(rtm->rtm_flags & RTM_F_CLONED))
1734                 return 0;
1735
1736         s_h = cb->args[0];
1737         s_idx = idx = cb->args[1];
1738         for(h = 0; h <= dn_rt_hash_mask; h++) {
1739                 if (h < s_h)
1740                         continue;
1741                 if (h > s_h)
1742                         s_idx = 0;
1743                 rcu_read_lock_bh();
1744                 for(rt = rcu_dereference_bh(dn_rt_hash_table[h].chain), idx = 0;
1745                         rt;
1746                         rt = rcu_dereference_bh(rt->dn_next), idx++) {
1747                         if (idx < s_idx)
1748                                 continue;
1749                         skb_dst_set(skb, dst_clone(&rt->dst));
1750                         if (dn_rt_fill_info(skb, NETLINK_CB(cb->skb).portid,
1751                                         cb->nlh->nlmsg_seq, RTM_NEWROUTE,
1752                                         1, NLM_F_MULTI) < 0) {
1753                                 skb_dst_drop(skb);
1754                                 rcu_read_unlock_bh();
1755                                 goto done;
1756                         }
1757                         skb_dst_drop(skb);
1758                 }
1759                 rcu_read_unlock_bh();
1760         }
1761
1762 done:
1763         cb->args[0] = h;
1764         cb->args[1] = idx;
1765         return skb->len;
1766 }
1767
1768 #ifdef CONFIG_PROC_FS
1769 struct dn_rt_cache_iter_state {
1770         int bucket;
1771 };
1772
1773 static struct dn_route *dn_rt_cache_get_first(struct seq_file *seq)
1774 {
1775         struct dn_route *rt = NULL;
1776         struct dn_rt_cache_iter_state *s = seq->private;
1777
1778         for(s->bucket = dn_rt_hash_mask; s->bucket >= 0; --s->bucket) {
1779                 rcu_read_lock_bh();
1780                 rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1781                 if (rt)
1782                         break;
1783                 rcu_read_unlock_bh();
1784         }
1785         return rt;
1786 }
1787
1788 static struct dn_route *dn_rt_cache_get_next(struct seq_file *seq, struct dn_route *rt)
1789 {
1790         struct dn_rt_cache_iter_state *s = seq->private;
1791
1792         rt = rcu_dereference_bh(rt->dn_next);
1793         while (!rt) {
1794                 rcu_read_unlock_bh();
1795                 if (--s->bucket < 0)
1796                         break;
1797                 rcu_read_lock_bh();
1798                 rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1799         }
1800         return rt;
1801 }
1802
1803 static void *dn_rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
1804 {
1805         struct dn_route *rt = dn_rt_cache_get_first(seq);
1806
1807         if (rt) {
1808                 while(*pos && (rt = dn_rt_cache_get_next(seq, rt)))
1809                         --*pos;
1810         }
1811         return *pos ? NULL : rt;
1812 }
1813
1814 static void *dn_rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1815 {
1816         struct dn_route *rt = dn_rt_cache_get_next(seq, v);
1817         ++*pos;
1818         return rt;
1819 }
1820
1821 static void dn_rt_cache_seq_stop(struct seq_file *seq, void *v)
1822 {
1823         if (v)
1824                 rcu_read_unlock_bh();
1825 }
1826
1827 static int dn_rt_cache_seq_show(struct seq_file *seq, void *v)
1828 {
1829         struct dn_route *rt = v;
1830         char buf1[DN_ASCBUF_LEN], buf2[DN_ASCBUF_LEN];
1831
1832         seq_printf(seq, "%-8s %-7s %-7s %04d %04d %04d\n",
1833                    rt->dst.dev ? rt->dst.dev->name : "*",
1834                    dn_addr2asc(le16_to_cpu(rt->rt_daddr), buf1),
1835                    dn_addr2asc(le16_to_cpu(rt->rt_saddr), buf2),
1836                    atomic_read(&rt->dst.__refcnt),
1837                    rt->dst.__use, 0);
1838         return 0;
1839 }
1840
1841 static const struct seq_operations dn_rt_cache_seq_ops = {
1842         .start  = dn_rt_cache_seq_start,
1843         .next   = dn_rt_cache_seq_next,
1844         .stop   = dn_rt_cache_seq_stop,
1845         .show   = dn_rt_cache_seq_show,
1846 };
1847 #endif /* CONFIG_PROC_FS */
1848
1849 void __init dn_route_init(void)
1850 {
1851         int i, goal, order;
1852
1853         dn_dst_ops.kmem_cachep =
1854                 kmem_cache_create("dn_dst_cache", sizeof(struct dn_route), 0,
1855                                   SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
1856         dst_entries_init(&dn_dst_ops);
1857         timer_setup(&dn_route_timer, dn_dst_check_expire, 0);
1858         dn_route_timer.expires = jiffies + decnet_dst_gc_interval * HZ;
1859         add_timer(&dn_route_timer);
1860
1861         goal = totalram_pages() >> (26 - PAGE_SHIFT);
1862
1863         for(order = 0; (1UL << order) < goal; order++)
1864                 /* NOTHING */;
1865
1866         /*
1867          * Only want 1024 entries max, since the table is very, very unlikely
1868          * to be larger than that.
1869          */
1870         while(order && ((((1UL << order) * PAGE_SIZE) /
1871                                 sizeof(struct dn_rt_hash_bucket)) >= 2048))
1872                 order--;
1873
1874         do {
1875                 dn_rt_hash_mask = (1UL << order) * PAGE_SIZE /
1876                         sizeof(struct dn_rt_hash_bucket);
1877                 while(dn_rt_hash_mask & (dn_rt_hash_mask - 1))
1878                         dn_rt_hash_mask--;
1879                 dn_rt_hash_table = (struct dn_rt_hash_bucket *)
1880                         __get_free_pages(GFP_ATOMIC, order);
1881         } while (dn_rt_hash_table == NULL && --order > 0);
1882
1883         if (!dn_rt_hash_table)
1884                 panic("Failed to allocate DECnet route cache hash table\n");
1885
1886         printk(KERN_INFO
1887                 "DECnet: Routing cache hash table of %u buckets, %ldKbytes\n",
1888                 dn_rt_hash_mask,
1889                 (long)(dn_rt_hash_mask*sizeof(struct dn_rt_hash_bucket))/1024);
1890
1891         dn_rt_hash_mask--;
1892         for(i = 0; i <= dn_rt_hash_mask; i++) {
1893                 spin_lock_init(&dn_rt_hash_table[i].lock);
1894                 dn_rt_hash_table[i].chain = NULL;
1895         }
1896
1897         dn_dst_ops.gc_thresh = (dn_rt_hash_mask + 1);
1898
1899         proc_create_seq_private("decnet_cache", 0444, init_net.proc_net,
1900                         &dn_rt_cache_seq_ops,
1901                         sizeof(struct dn_rt_cache_iter_state), NULL);
1902
1903 #ifdef CONFIG_DECNET_ROUTER
1904         rtnl_register_module(THIS_MODULE, PF_DECnet, RTM_GETROUTE,
1905                              dn_cache_getroute, dn_fib_dump, 0);
1906 #else
1907         rtnl_register_module(THIS_MODULE, PF_DECnet, RTM_GETROUTE,
1908                              dn_cache_getroute, dn_cache_dump, 0);
1909 #endif
1910 }
1911
1912 void __exit dn_route_cleanup(void)
1913 {
1914         del_timer(&dn_route_timer);
1915         dn_run_flush(NULL);
1916
1917         remove_proc_entry("decnet_cache", init_net.proc_net);
1918         dst_entries_destroy(&dn_dst_ops);
1919 }