linux/net/decnet/dn_route.c
<<
>>
Prefs
   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
  87struct dn_rt_hash_bucket
  88{
  89        struct dn_route __rcu *chain;
  90        spinlock_t lock;
  91};
  92
  93extern struct neigh_table dn_neigh_table;
  94
  95
  96static unsigned char dn_hiord_addr[6] = {0xAA,0x00,0x04,0x00,0x00,0x00};
  97
  98static const int dn_rt_min_delay = 2 * HZ;
  99static const int dn_rt_max_delay = 10 * HZ;
 100static const int dn_rt_mtu_expires = 10 * 60 * HZ;
 101
 102static unsigned long dn_rt_deadline;
 103
 104static int dn_dst_gc(struct dst_ops *ops);
 105static struct dst_entry *dn_dst_check(struct dst_entry *, __u32);
 106static unsigned int dn_dst_default_advmss(const struct dst_entry *dst);
 107static unsigned int dn_dst_mtu(const struct dst_entry *dst);
 108static void dn_dst_destroy(struct dst_entry *);
 109static void dn_dst_ifdown(struct dst_entry *, struct net_device *dev, int how);
 110static struct dst_entry *dn_dst_negative_advice(struct dst_entry *);
 111static void dn_dst_link_failure(struct sk_buff *);
 112static void dn_dst_update_pmtu(struct dst_entry *dst, struct sock *sk,
 113                               struct sk_buff *skb , u32 mtu,
 114                               bool confirm_neigh);
 115static void dn_dst_redirect(struct dst_entry *dst, struct sock *sk,
 116                            struct sk_buff *skb);
 117static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst,
 118                                             struct sk_buff *skb,
 119                                             const void *daddr);
 120static int dn_route_input(struct sk_buff *);
 121static void dn_run_flush(struct timer_list *unused);
 122
 123static struct dn_rt_hash_bucket *dn_rt_hash_table;
 124static unsigned int dn_rt_hash_mask;
 125
 126static struct timer_list dn_route_timer;
 127static DEFINE_TIMER(dn_rt_flush_timer, dn_run_flush);
 128int decnet_dst_gc_interval = 2;
 129
 130static struct dst_ops dn_dst_ops = {
 131        .family =               PF_DECnet,
 132        .gc_thresh =            128,
 133        .gc =                   dn_dst_gc,
 134        .check =                dn_dst_check,
 135        .default_advmss =       dn_dst_default_advmss,
 136        .mtu =                  dn_dst_mtu,
 137        .cow_metrics =          dst_cow_metrics_generic,
 138        .destroy =              dn_dst_destroy,
 139        .ifdown =               dn_dst_ifdown,
 140        .negative_advice =      dn_dst_negative_advice,
 141        .link_failure =         dn_dst_link_failure,
 142        .update_pmtu =          dn_dst_update_pmtu,
 143        .redirect =             dn_dst_redirect,
 144        .neigh_lookup =         dn_dst_neigh_lookup,
 145};
 146
 147static void dn_dst_destroy(struct dst_entry *dst)
 148{
 149        struct dn_route *rt = (struct dn_route *) dst;
 150
 151        if (rt->n)
 152                neigh_release(rt->n);
 153        dst_destroy_metrics_generic(dst);
 154}
 155
 156static void dn_dst_ifdown(struct dst_entry *dst, struct net_device *dev, int how)
 157{
 158        if (how) {
 159                struct dn_route *rt = (struct dn_route *) dst;
 160                struct neighbour *n = rt->n;
 161
 162                if (n && n->dev == dev) {
 163                        n->dev = dev_net(dev)->loopback_dev;
 164                        dev_hold(n->dev);
 165                        dev_put(dev);
 166                }
 167        }
 168}
 169
 170static __inline__ unsigned int dn_hash(__le16 src, __le16 dst)
 171{
 172        __u16 tmp = (__u16 __force)(src ^ dst);
 173        tmp ^= (tmp >> 3);
 174        tmp ^= (tmp >> 5);
 175        tmp ^= (tmp >> 10);
 176        return dn_rt_hash_mask & (unsigned int)tmp;
 177}
 178
 179static void dn_dst_check_expire(struct timer_list *unused)
 180{
 181        int i;
 182        struct dn_route *rt;
 183        struct dn_route __rcu **rtp;
 184        unsigned long now = jiffies;
 185        unsigned long expire = 120 * HZ;
 186
 187        for (i = 0; i <= dn_rt_hash_mask; i++) {
 188                rtp = &dn_rt_hash_table[i].chain;
 189
 190                spin_lock(&dn_rt_hash_table[i].lock);
 191                while ((rt = rcu_dereference_protected(*rtp,
 192                                                lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) {
 193                        if (atomic_read(&rt->dst.__refcnt) > 1 ||
 194                            (now - rt->dst.lastuse) < expire) {
 195                                rtp = &rt->dn_next;
 196                                continue;
 197                        }
 198                        *rtp = rt->dn_next;
 199                        rt->dn_next = NULL;
 200                        dst_dev_put(&rt->dst);
 201                        dst_release(&rt->dst);
 202                }
 203                spin_unlock(&dn_rt_hash_table[i].lock);
 204
 205                if ((jiffies - now) > 0)
 206                        break;
 207        }
 208
 209        mod_timer(&dn_route_timer, now + decnet_dst_gc_interval * HZ);
 210}
 211
 212static int dn_dst_gc(struct dst_ops *ops)
 213{
 214        struct dn_route *rt;
 215        struct dn_route __rcu **rtp;
 216        int i;
 217        unsigned long now = jiffies;
 218        unsigned long expire = 10 * HZ;
 219
 220        for (i = 0; i <= dn_rt_hash_mask; i++) {
 221
 222                spin_lock_bh(&dn_rt_hash_table[i].lock);
 223                rtp = &dn_rt_hash_table[i].chain;
 224
 225                while ((rt = rcu_dereference_protected(*rtp,
 226                                                lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) {
 227                        if (atomic_read(&rt->dst.__refcnt) > 1 ||
 228                            (now - rt->dst.lastuse) < expire) {
 229                                rtp = &rt->dn_next;
 230                                continue;
 231                        }
 232                        *rtp = rt->dn_next;
 233                        rt->dn_next = NULL;
 234                        dst_dev_put(&rt->dst);
 235                        dst_release(&rt->dst);
 236                        break;
 237                }
 238                spin_unlock_bh(&dn_rt_hash_table[i].lock);
 239        }
 240
 241        return 0;
 242}
 243
 244/*
 245 * The decnet standards don't impose a particular minimum mtu, what they
 246 * do insist on is that the routing layer accepts a datagram of at least
 247 * 230 bytes long. Here we have to subtract the routing header length from
 248 * 230 to get the minimum acceptable mtu. If there is no neighbour, then we
 249 * assume the worst and use a long header size.
 250 *
 251 * We update both the mtu and the advertised mss (i.e. the segment size we
 252 * advertise to the other end).
 253 */
 254static void dn_dst_update_pmtu(struct dst_entry *dst, struct sock *sk,
 255                               struct sk_buff *skb, u32 mtu,
 256                               bool confirm_neigh)
 257{
 258        struct dn_route *rt = (struct dn_route *) dst;
 259        struct neighbour *n = rt->n;
 260        u32 min_mtu = 230;
 261        struct dn_dev *dn;
 262
 263        dn = n ? rcu_dereference_raw(n->dev->dn_ptr) : NULL;
 264
 265        if (dn && dn->use_long == 0)
 266                min_mtu -= 6;
 267        else
 268                min_mtu -= 21;
 269
 270        if (dst_metric(dst, RTAX_MTU) > mtu && mtu >= min_mtu) {
 271                if (!(dst_metric_locked(dst, RTAX_MTU))) {
 272                        dst_metric_set(dst, RTAX_MTU, mtu);
 273                        dst_set_expires(dst, dn_rt_mtu_expires);
 274                }
 275                if (!(dst_metric_locked(dst, RTAX_ADVMSS))) {
 276                        u32 mss = mtu - DN_MAX_NSP_DATA_HEADER;
 277                        u32 existing_mss = dst_metric_raw(dst, RTAX_ADVMSS);
 278                        if (!existing_mss || existing_mss > mss)
 279                                dst_metric_set(dst, RTAX_ADVMSS, mss);
 280                }
 281        }
 282}
 283
 284static void dn_dst_redirect(struct dst_entry *dst, struct sock *sk,
 285                            struct sk_buff *skb)
 286{
 287}
 288
 289/*
 290 * When a route has been marked obsolete. (e.g. routing cache flush)
 291 */
 292static struct dst_entry *dn_dst_check(struct dst_entry *dst, __u32 cookie)
 293{
 294        return NULL;
 295}
 296
 297static struct dst_entry *dn_dst_negative_advice(struct dst_entry *dst)
 298{
 299        dst_release(dst);
 300        return NULL;
 301}
 302
 303static void dn_dst_link_failure(struct sk_buff *skb)
 304{
 305}
 306
 307static inline int compare_keys(struct flowidn *fl1, struct flowidn *fl2)
 308{
 309        return ((fl1->daddr ^ fl2->daddr) |
 310                (fl1->saddr ^ fl2->saddr) |
 311                (fl1->flowidn_mark ^ fl2->flowidn_mark) |
 312                (fl1->flowidn_scope ^ fl2->flowidn_scope) |
 313                (fl1->flowidn_oif ^ fl2->flowidn_oif) |
 314                (fl1->flowidn_iif ^ fl2->flowidn_iif)) == 0;
 315}
 316
 317static int dn_insert_route(struct dn_route *rt, unsigned int hash, struct dn_route **rp)
 318{
 319        struct dn_route *rth;
 320        struct dn_route __rcu **rthp;
 321        unsigned long now = jiffies;
 322
 323        rthp = &dn_rt_hash_table[hash].chain;
 324
 325        spin_lock_bh(&dn_rt_hash_table[hash].lock);
 326        while ((rth = rcu_dereference_protected(*rthp,
 327                                                lockdep_is_held(&dn_rt_hash_table[hash].lock))) != NULL) {
 328                if (compare_keys(&rth->fld, &rt->fld)) {
 329                        /* Put it first */
 330                        *rthp = rth->dn_next;
 331                        rcu_assign_pointer(rth->dn_next,
 332                                           dn_rt_hash_table[hash].chain);
 333                        rcu_assign_pointer(dn_rt_hash_table[hash].chain, rth);
 334
 335                        dst_hold_and_use(&rth->dst, now);
 336                        spin_unlock_bh(&dn_rt_hash_table[hash].lock);
 337
 338                        dst_release_immediate(&rt->dst);
 339                        *rp = rth;
 340                        return 0;
 341                }
 342                rthp = &rth->dn_next;
 343        }
 344
 345        rcu_assign_pointer(rt->dn_next, dn_rt_hash_table[hash].chain);
 346        rcu_assign_pointer(dn_rt_hash_table[hash].chain, rt);
 347
 348        dst_hold_and_use(&rt->dst, now);
 349        spin_unlock_bh(&dn_rt_hash_table[hash].lock);
 350        *rp = rt;
 351        return 0;
 352}
 353
 354static void dn_run_flush(struct timer_list *unused)
 355{
 356        int i;
 357        struct dn_route *rt, *next;
 358
 359        for (i = 0; i < dn_rt_hash_mask; i++) {
 360                spin_lock_bh(&dn_rt_hash_table[i].lock);
 361
 362                if ((rt = xchg((struct dn_route **)&dn_rt_hash_table[i].chain, NULL)) == NULL)
 363                        goto nothing_to_declare;
 364
 365                for(; rt; rt = next) {
 366                        next = rcu_dereference_raw(rt->dn_next);
 367                        RCU_INIT_POINTER(rt->dn_next, NULL);
 368                        dst_dev_put(&rt->dst);
 369                        dst_release(&rt->dst);
 370                }
 371
 372nothing_to_declare:
 373                spin_unlock_bh(&dn_rt_hash_table[i].lock);
 374        }
 375}
 376
 377static DEFINE_SPINLOCK(dn_rt_flush_lock);
 378
 379void dn_rt_cache_flush(int delay)
 380{
 381        unsigned long now = jiffies;
 382        int user_mode = !in_interrupt();
 383
 384        if (delay < 0)
 385                delay = dn_rt_min_delay;
 386
 387        spin_lock_bh(&dn_rt_flush_lock);
 388
 389        if (del_timer(&dn_rt_flush_timer) && delay > 0 && dn_rt_deadline) {
 390                long tmo = (long)(dn_rt_deadline - now);
 391
 392                if (user_mode && tmo < dn_rt_max_delay - dn_rt_min_delay)
 393                        tmo = 0;
 394
 395                if (delay > tmo)
 396                        delay = tmo;
 397        }
 398
 399        if (delay <= 0) {
 400                spin_unlock_bh(&dn_rt_flush_lock);
 401                dn_run_flush(NULL);
 402                return;
 403        }
 404
 405        if (dn_rt_deadline == 0)
 406                dn_rt_deadline = now + dn_rt_max_delay;
 407
 408        dn_rt_flush_timer.expires = now + delay;
 409        add_timer(&dn_rt_flush_timer);
 410        spin_unlock_bh(&dn_rt_flush_lock);
 411}
 412
 413/**
 414 * dn_return_short - Return a short packet to its sender
 415 * @skb: The packet to return
 416 *
 417 */
 418static int dn_return_short(struct sk_buff *skb)
 419{
 420        struct dn_skb_cb *cb;
 421        unsigned char *ptr;
 422        __le16 *src;
 423        __le16 *dst;
 424
 425        /* Add back headers */
 426        skb_push(skb, skb->data - skb_network_header(skb));
 427
 428        if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
 429                return NET_RX_DROP;
 430
 431        cb = DN_SKB_CB(skb);
 432        /* Skip packet length and point to flags */
 433        ptr = skb->data + 2;
 434        *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
 435
 436        dst = (__le16 *)ptr;
 437        ptr += 2;
 438        src = (__le16 *)ptr;
 439        ptr += 2;
 440        *ptr = 0; /* Zero hop count */
 441
 442        swap(*src, *dst);
 443
 444        skb->pkt_type = PACKET_OUTGOING;
 445        dn_rt_finish_output(skb, NULL, NULL);
 446        return NET_RX_SUCCESS;
 447}
 448
 449/**
 450 * dn_return_long - Return a long packet to its sender
 451 * @skb: The long format packet to return
 452 *
 453 */
 454static int dn_return_long(struct sk_buff *skb)
 455{
 456        struct dn_skb_cb *cb;
 457        unsigned char *ptr;
 458        unsigned char *src_addr, *dst_addr;
 459        unsigned char tmp[ETH_ALEN];
 460
 461        /* Add back all headers */
 462        skb_push(skb, skb->data - skb_network_header(skb));
 463
 464        if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
 465                return NET_RX_DROP;
 466
 467        cb = DN_SKB_CB(skb);
 468        /* Ignore packet length and point to flags */
 469        ptr = skb->data + 2;
 470
 471        /* Skip padding */
 472        if (*ptr & DN_RT_F_PF) {
 473                char padlen = (*ptr & ~DN_RT_F_PF);
 474                ptr += padlen;
 475        }
 476
 477        *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
 478        ptr += 2;
 479        dst_addr = ptr;
 480        ptr += 8;
 481        src_addr = ptr;
 482        ptr += 6;
 483        *ptr = 0; /* Zero hop count */
 484
 485        /* Swap source and destination */
 486        memcpy(tmp, src_addr, ETH_ALEN);
 487        memcpy(src_addr, dst_addr, ETH_ALEN);
 488        memcpy(dst_addr, tmp, ETH_ALEN);
 489
 490        skb->pkt_type = PACKET_OUTGOING;
 491        dn_rt_finish_output(skb, dst_addr, src_addr);
 492        return NET_RX_SUCCESS;
 493}
 494
 495/**
 496 * dn_route_rx_packet - Try and find a route for an incoming packet
 497 * @net: The applicable net namespace
 498 * @sk: Socket packet transmitted on
 499 * @skb: The packet to find a route for
 500 *
 501 * Returns: result of input function if route is found, error code otherwise
 502 */
 503static int dn_route_rx_packet(struct net *net, struct sock *sk, struct sk_buff *skb)
 504{
 505        struct dn_skb_cb *cb;
 506        int err;
 507
 508        if ((err = dn_route_input(skb)) == 0)
 509                return dst_input(skb);
 510
 511        cb = DN_SKB_CB(skb);
 512        if (decnet_debug_level & 4) {
 513                char *devname = skb->dev ? skb->dev->name : "???";
 514
 515                printk(KERN_DEBUG
 516                        "DECnet: dn_route_rx_packet: rt_flags=0x%02x dev=%s len=%d src=0x%04hx dst=0x%04hx err=%d type=%d\n",
 517                        (int)cb->rt_flags, devname, skb->len,
 518                        le16_to_cpu(cb->src), le16_to_cpu(cb->dst),
 519                        err, skb->pkt_type);
 520        }
 521
 522        if ((skb->pkt_type == PACKET_HOST) && (cb->rt_flags & DN_RT_F_RQR)) {
 523                switch (cb->rt_flags & DN_RT_PKT_MSK) {
 524                case DN_RT_PKT_SHORT:
 525                        return dn_return_short(skb);
 526                case DN_RT_PKT_LONG:
 527                        return dn_return_long(skb);
 528                }
 529        }
 530
 531        kfree_skb(skb);
 532        return NET_RX_DROP;
 533}
 534
 535static int dn_route_rx_long(struct sk_buff *skb)
 536{
 537        struct dn_skb_cb *cb = DN_SKB_CB(skb);
 538        unsigned char *ptr = skb->data;
 539
 540        if (!pskb_may_pull(skb, 21)) /* 20 for long header, 1 for shortest nsp */
 541                goto drop_it;
 542
 543        skb_pull(skb, 20);
 544        skb_reset_transport_header(skb);
 545
 546        /* Destination info */
 547        ptr += 2;
 548        cb->dst = dn_eth2dn(ptr);
 549        if (memcmp(ptr, dn_hiord_addr, 4) != 0)
 550                goto drop_it;
 551        ptr += 6;
 552
 553
 554        /* Source info */
 555        ptr += 2;
 556        cb->src = dn_eth2dn(ptr);
 557        if (memcmp(ptr, dn_hiord_addr, 4) != 0)
 558                goto drop_it;
 559        ptr += 6;
 560        /* Other junk */
 561        ptr++;
 562        cb->hops = *ptr++; /* Visit Count */
 563
 564        return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING,
 565                       &init_net, NULL, skb, skb->dev, NULL,
 566                       dn_route_rx_packet);
 567
 568drop_it:
 569        kfree_skb(skb);
 570        return NET_RX_DROP;
 571}
 572
 573
 574
 575static int dn_route_rx_short(struct sk_buff *skb)
 576{
 577        struct dn_skb_cb *cb = DN_SKB_CB(skb);
 578        unsigned char *ptr = skb->data;
 579
 580        if (!pskb_may_pull(skb, 6)) /* 5 for short header + 1 for shortest nsp */
 581                goto drop_it;
 582
 583        skb_pull(skb, 5);
 584        skb_reset_transport_header(skb);
 585
 586        cb->dst = *(__le16 *)ptr;
 587        ptr += 2;
 588        cb->src = *(__le16 *)ptr;
 589        ptr += 2;
 590        cb->hops = *ptr & 0x3f;
 591
 592        return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING,
 593                       &init_net, NULL, skb, skb->dev, NULL,
 594                       dn_route_rx_packet);
 595
 596drop_it:
 597        kfree_skb(skb);
 598        return NET_RX_DROP;
 599}
 600
 601static int dn_route_discard(struct net *net, struct sock *sk, struct sk_buff *skb)
 602{
 603        /*
 604         * I know we drop the packet here, but thats considered success in
 605         * this case
 606         */
 607        kfree_skb(skb);
 608        return NET_RX_SUCCESS;
 609}
 610
 611static int dn_route_ptp_hello(struct net *net, struct sock *sk, struct sk_buff *skb)
 612{
 613        dn_dev_hello(skb);
 614        dn_neigh_pointopoint_hello(skb);
 615        return NET_RX_SUCCESS;
 616}
 617
 618int dn_route_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
 619{
 620        struct dn_skb_cb *cb;
 621        unsigned char flags = 0;
 622        __u16 len = le16_to_cpu(*(__le16 *)skb->data);
 623        struct dn_dev *dn = rcu_dereference(dev->dn_ptr);
 624        unsigned char padlen = 0;
 625
 626        if (!net_eq(dev_net(dev), &init_net))
 627                goto dump_it;
 628
 629        if (dn == NULL)
 630                goto dump_it;
 631
 632        if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
 633                goto out;
 634
 635        if (!pskb_may_pull(skb, 3))
 636                goto dump_it;
 637
 638        skb_pull(skb, 2);
 639
 640        if (len > skb->len)
 641                goto dump_it;
 642
 643        skb_trim(skb, len);
 644
 645        flags = *skb->data;
 646
 647        cb = DN_SKB_CB(skb);
 648        cb->stamp = jiffies;
 649        cb->iif = dev->ifindex;
 650
 651        /*
 652         * If we have padding, remove it.
 653         */
 654        if (flags & DN_RT_F_PF) {
 655                padlen = flags & ~DN_RT_F_PF;
 656                if (!pskb_may_pull(skb, padlen + 1))
 657                        goto dump_it;
 658                skb_pull(skb, padlen);
 659                flags = *skb->data;
 660        }
 661
 662        skb_reset_network_header(skb);
 663
 664        /*
 665         * Weed out future version DECnet
 666         */
 667        if (flags & DN_RT_F_VER)
 668                goto dump_it;
 669
 670        cb->rt_flags = flags;
 671
 672        if (decnet_debug_level & 1)
 673                printk(KERN_DEBUG
 674                        "dn_route_rcv: got 0x%02x from %s [%d %d %d]\n",
 675                        (int)flags, dev->name, len, skb->len,
 676                        padlen);
 677
 678        if (flags & DN_RT_PKT_CNTL) {
 679                if (unlikely(skb_linearize(skb)))
 680                        goto dump_it;
 681
 682                switch (flags & DN_RT_CNTL_MSK) {
 683                case DN_RT_PKT_INIT:
 684                        dn_dev_init_pkt(skb);
 685                        break;
 686                case DN_RT_PKT_VERI:
 687                        dn_dev_veri_pkt(skb);
 688                        break;
 689                }
 690
 691                if (dn->parms.state != DN_DEV_S_RU)
 692                        goto dump_it;
 693
 694                switch (flags & DN_RT_CNTL_MSK) {
 695                case DN_RT_PKT_HELO:
 696                        return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
 697                                       &init_net, NULL, skb, skb->dev, NULL,
 698                                       dn_route_ptp_hello);
 699
 700                case DN_RT_PKT_L1RT:
 701                case DN_RT_PKT_L2RT:
 702                        return NF_HOOK(NFPROTO_DECNET, NF_DN_ROUTE,
 703                                       &init_net, NULL, skb, skb->dev, NULL,
 704                                       dn_route_discard);
 705                case DN_RT_PKT_ERTH:
 706                        return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
 707                                       &init_net, NULL, skb, skb->dev, NULL,
 708                                       dn_neigh_router_hello);
 709
 710                case DN_RT_PKT_EEDH:
 711                        return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
 712                                       &init_net, NULL, skb, skb->dev, NULL,
 713                                       dn_neigh_endnode_hello);
 714                }
 715        } else {
 716                if (dn->parms.state != DN_DEV_S_RU)
 717                        goto dump_it;
 718
 719                skb_pull(skb, 1); /* Pull flags */
 720
 721                switch (flags & DN_RT_PKT_MSK) {
 722                case DN_RT_PKT_LONG:
 723                        return dn_route_rx_long(skb);
 724                case DN_RT_PKT_SHORT:
 725                        return dn_route_rx_short(skb);
 726                }
 727        }
 728
 729dump_it:
 730        kfree_skb(skb);
 731out:
 732        return NET_RX_DROP;
 733}
 734
 735static int dn_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 736{
 737        struct dst_entry *dst = skb_dst(skb);
 738        struct dn_route *rt = (struct dn_route *)dst;
 739        struct net_device *dev = dst->dev;
 740        struct dn_skb_cb *cb = DN_SKB_CB(skb);
 741
 742        int err = -EINVAL;
 743
 744        if (rt->n == NULL)
 745                goto error;
 746
 747        skb->dev = dev;
 748
 749        cb->src = rt->rt_saddr;
 750        cb->dst = rt->rt_daddr;
 751
 752        /*
 753         * Always set the Intra-Ethernet bit on all outgoing packets
 754         * originated on this node. Only valid flag from upper layers
 755         * is return-to-sender-requested. Set hop count to 0 too.
 756         */
 757        cb->rt_flags &= ~DN_RT_F_RQR;
 758        cb->rt_flags |= DN_RT_F_IE;
 759        cb->hops = 0;
 760
 761        return NF_HOOK(NFPROTO_DECNET, NF_DN_LOCAL_OUT,
 762                       &init_net, sk, skb, NULL, dev,
 763                       dn_to_neigh_output);
 764
 765error:
 766        net_dbg_ratelimited("dn_output: This should not happen\n");
 767
 768        kfree_skb(skb);
 769
 770        return err;
 771}
 772
 773static int dn_forward(struct sk_buff *skb)
 774{
 775        struct dn_skb_cb *cb = DN_SKB_CB(skb);
 776        struct dst_entry *dst = skb_dst(skb);
 777        struct dn_dev *dn_db = rcu_dereference(dst->dev->dn_ptr);
 778        struct dn_route *rt;
 779        int header_len;
 780        struct net_device *dev = skb->dev;
 781
 782        if (skb->pkt_type != PACKET_HOST)
 783                goto drop;
 784
 785        /* Ensure that we have enough space for headers */
 786        rt = (struct dn_route *)skb_dst(skb);
 787        header_len = dn_db->use_long ? 21 : 6;
 788        if (skb_cow(skb, LL_RESERVED_SPACE(rt->dst.dev)+header_len))
 789                goto drop;
 790
 791        /*
 792         * Hop count exceeded.
 793         */
 794        if (++cb->hops > 30)
 795                goto drop;
 796
 797        skb->dev = rt->dst.dev;
 798
 799        /*
 800         * If packet goes out same interface it came in on, then set
 801         * the Intra-Ethernet bit. This has no effect for short
 802         * packets, so we don't need to test for them here.
 803         */
 804        cb->rt_flags &= ~DN_RT_F_IE;
 805        if (rt->rt_flags & RTCF_DOREDIRECT)
 806                cb->rt_flags |= DN_RT_F_IE;
 807
 808        return NF_HOOK(NFPROTO_DECNET, NF_DN_FORWARD,
 809                       &init_net, NULL, skb, dev, skb->dev,
 810                       dn_to_neigh_output);
 811
 812drop:
 813        kfree_skb(skb);
 814        return NET_RX_DROP;
 815}
 816
 817/*
 818 * Used to catch bugs. This should never normally get
 819 * called.
 820 */
 821static int dn_rt_bug_out(struct net *net, struct sock *sk, struct sk_buff *skb)
 822{
 823        struct dn_skb_cb *cb = DN_SKB_CB(skb);
 824
 825        net_dbg_ratelimited("dn_rt_bug: skb from:%04x to:%04x\n",
 826                            le16_to_cpu(cb->src), le16_to_cpu(cb->dst));
 827
 828        kfree_skb(skb);
 829
 830        return NET_RX_DROP;
 831}
 832
 833static int dn_rt_bug(struct sk_buff *skb)
 834{
 835        struct dn_skb_cb *cb = DN_SKB_CB(skb);
 836
 837        net_dbg_ratelimited("dn_rt_bug: skb from:%04x to:%04x\n",
 838                            le16_to_cpu(cb->src), le16_to_cpu(cb->dst));
 839
 840        kfree_skb(skb);
 841
 842        return NET_RX_DROP;
 843}
 844
 845static unsigned int dn_dst_default_advmss(const struct dst_entry *dst)
 846{
 847        return dn_mss_from_pmtu(dst->dev, dst_mtu(dst));
 848}
 849
 850static unsigned int dn_dst_mtu(const struct dst_entry *dst)
 851{
 852        unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
 853
 854        return mtu ? : dst->dev->mtu;
 855}
 856
 857static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst,
 858                                             struct sk_buff *skb,
 859                                             const void *daddr)
 860{
 861        return __neigh_lookup_errno(&dn_neigh_table, daddr, dst->dev);
 862}
 863
 864static int dn_rt_set_next_hop(struct dn_route *rt, struct dn_fib_res *res)
 865{
 866        struct dn_fib_info *fi = res->fi;
 867        struct net_device *dev = rt->dst.dev;
 868        unsigned int mss_metric;
 869        struct neighbour *n;
 870
 871        if (fi) {
 872                if (DN_FIB_RES_GW(*res) &&
 873                    DN_FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
 874                        rt->rt_gateway = DN_FIB_RES_GW(*res);
 875                dst_init_metrics(&rt->dst, fi->fib_metrics, true);
 876        }
 877        rt->rt_type = res->type;
 878
 879        if (dev != NULL && rt->n == NULL) {
 880                n = __neigh_lookup_errno(&dn_neigh_table, &rt->rt_gateway, dev);
 881                if (IS_ERR(n))
 882                        return PTR_ERR(n);
 883                rt->n = n;
 884        }
 885
 886        if (dst_metric(&rt->dst, RTAX_MTU) > rt->dst.dev->mtu)
 887                dst_metric_set(&rt->dst, RTAX_MTU, rt->dst.dev->mtu);
 888        mss_metric = dst_metric_raw(&rt->dst, RTAX_ADVMSS);
 889        if (mss_metric) {
 890                unsigned int mss = dn_mss_from_pmtu(dev, dst_mtu(&rt->dst));
 891                if (mss_metric > mss)
 892                        dst_metric_set(&rt->dst, RTAX_ADVMSS, mss);
 893        }
 894        return 0;
 895}
 896
 897static inline int dn_match_addr(__le16 addr1, __le16 addr2)
 898{
 899        __u16 tmp = le16_to_cpu(addr1) ^ le16_to_cpu(addr2);
 900        int match = 16;
 901        while(tmp) {
 902                tmp >>= 1;
 903                match--;
 904        }
 905        return match;
 906}
 907
 908static __le16 dnet_select_source(const struct net_device *dev, __le16 daddr, int scope)
 909{
 910        __le16 saddr = 0;
 911        struct dn_dev *dn_db;
 912        struct dn_ifaddr *ifa;
 913        int best_match = 0;
 914        int ret;
 915
 916        rcu_read_lock();
 917        dn_db = rcu_dereference(dev->dn_ptr);
 918        for (ifa = rcu_dereference(dn_db->ifa_list);
 919             ifa != NULL;
 920             ifa = rcu_dereference(ifa->ifa_next)) {
 921                if (ifa->ifa_scope > scope)
 922                        continue;
 923                if (!daddr) {
 924                        saddr = ifa->ifa_local;
 925                        break;
 926                }
 927                ret = dn_match_addr(daddr, ifa->ifa_local);
 928                if (ret > best_match)
 929                        saddr = ifa->ifa_local;
 930                if (best_match == 0)
 931                        saddr = ifa->ifa_local;
 932        }
 933        rcu_read_unlock();
 934
 935        return saddr;
 936}
 937
 938static inline __le16 __dn_fib_res_prefsrc(struct dn_fib_res *res)
 939{
 940        return dnet_select_source(DN_FIB_RES_DEV(*res), DN_FIB_RES_GW(*res), res->scope);
 941}
 942
 943static inline __le16 dn_fib_rules_map_destination(__le16 daddr, struct dn_fib_res *res)
 944{
 945        __le16 mask = dnet_make_mask(res->prefixlen);
 946        return (daddr&~mask)|res->fi->fib_nh->nh_gw;
 947}
 948
 949static int dn_route_output_slow(struct dst_entry **pprt, const struct flowidn *oldflp, int try_hard)
 950{
 951        struct flowidn fld = {
 952                .daddr = oldflp->daddr,
 953                .saddr = oldflp->saddr,
 954                .flowidn_scope = RT_SCOPE_UNIVERSE,
 955                .flowidn_mark = oldflp->flowidn_mark,
 956                .flowidn_iif = LOOPBACK_IFINDEX,
 957                .flowidn_oif = oldflp->flowidn_oif,
 958        };
 959        struct dn_route *rt = NULL;
 960        struct net_device *dev_out = NULL, *dev;
 961        struct neighbour *neigh = NULL;
 962        unsigned int hash;
 963        unsigned int flags = 0;
 964        struct dn_fib_res res = { .fi = NULL, .type = RTN_UNICAST };
 965        int err;
 966        int free_res = 0;
 967        __le16 gateway = 0;
 968
 969        if (decnet_debug_level & 16)
 970                printk(KERN_DEBUG
 971                       "dn_route_output_slow: dst=%04x src=%04x mark=%d"
 972                       " iif=%d oif=%d\n", le16_to_cpu(oldflp->daddr),
 973                       le16_to_cpu(oldflp->saddr),
 974                       oldflp->flowidn_mark, LOOPBACK_IFINDEX,
 975                       oldflp->flowidn_oif);
 976
 977        /* If we have an output interface, verify its a DECnet device */
 978        if (oldflp->flowidn_oif) {
 979                dev_out = dev_get_by_index(&init_net, oldflp->flowidn_oif);
 980                err = -ENODEV;
 981                if (dev_out && dev_out->dn_ptr == NULL) {
 982                        dev_put(dev_out);
 983                        dev_out = NULL;
 984                }
 985                if (dev_out == NULL)
 986                        goto out;
 987        }
 988
 989        /* If we have a source address, verify that its a local address */
 990        if (oldflp->saddr) {
 991                err = -EADDRNOTAVAIL;
 992
 993                if (dev_out) {
 994                        if (dn_dev_islocal(dev_out, oldflp->saddr))
 995                                goto source_ok;
 996                        dev_put(dev_out);
 997                        goto out;
 998                }
 999                rcu_read_lock();
1000                for_each_netdev_rcu(&init_net, dev) {
1001                        if (!dev->dn_ptr)
1002                                continue;
1003                        if (!dn_dev_islocal(dev, oldflp->saddr))
1004                                continue;
1005                        if ((dev->flags & IFF_LOOPBACK) &&
1006                            oldflp->daddr &&
1007                            !dn_dev_islocal(dev, oldflp->daddr))
1008                                continue;
1009
1010                        dev_out = dev;
1011                        break;
1012                }
1013                rcu_read_unlock();
1014                if (dev_out == NULL)
1015                        goto out;
1016                dev_hold(dev_out);
1017source_ok:
1018                ;
1019        }
1020
1021        /* No destination? Assume its local */
1022        if (!fld.daddr) {
1023                fld.daddr = fld.saddr;
1024
1025                if (dev_out)
1026                        dev_put(dev_out);
1027                err = -EINVAL;
1028                dev_out = init_net.loopback_dev;
1029                if (!dev_out->dn_ptr)
1030                        goto out;
1031                err = -EADDRNOTAVAIL;
1032                dev_hold(dev_out);
1033                if (!fld.daddr) {
1034                        fld.daddr =
1035                        fld.saddr = dnet_select_source(dev_out, 0,
1036                                                       RT_SCOPE_HOST);
1037                        if (!fld.daddr)
1038                                goto out;
1039                }
1040                fld.flowidn_oif = LOOPBACK_IFINDEX;
1041                res.type = RTN_LOCAL;
1042                goto make_route;
1043        }
1044
1045        if (decnet_debug_level & 16)
1046                printk(KERN_DEBUG
1047                       "dn_route_output_slow: initial checks complete."
1048                       " dst=%04x src=%04x oif=%d try_hard=%d\n",
1049                       le16_to_cpu(fld.daddr), le16_to_cpu(fld.saddr),
1050                       fld.flowidn_oif, try_hard);
1051
1052        /*
1053         * N.B. If the kernel is compiled without router support then
1054         * dn_fib_lookup() will evaluate to non-zero so this if () block
1055         * will always be executed.
1056         */
1057        err = -ESRCH;
1058        if (try_hard || (err = dn_fib_lookup(&fld, &res)) != 0) {
1059                struct dn_dev *dn_db;
1060                if (err != -ESRCH)
1061                        goto out;
1062                /*
1063                 * Here the fallback is basically the standard algorithm for
1064                 * routing in endnodes which is described in the DECnet routing
1065                 * docs
1066                 *
1067                 * If we are not trying hard, look in neighbour cache.
1068                 * The result is tested to ensure that if a specific output
1069                 * device/source address was requested, then we honour that
1070                 * here
1071                 */
1072                if (!try_hard) {
1073                        neigh = neigh_lookup_nodev(&dn_neigh_table, &init_net, &fld.daddr);
1074                        if (neigh) {
1075                                if ((oldflp->flowidn_oif &&
1076                                    (neigh->dev->ifindex != oldflp->flowidn_oif)) ||
1077                                    (oldflp->saddr &&
1078                                    (!dn_dev_islocal(neigh->dev,
1079                                                     oldflp->saddr)))) {
1080                                        neigh_release(neigh);
1081                                        neigh = NULL;
1082                                } else {
1083                                        if (dev_out)
1084                                                dev_put(dev_out);
1085                                        if (dn_dev_islocal(neigh->dev, fld.daddr)) {
1086                                                dev_out = init_net.loopback_dev;
1087                                                res.type = RTN_LOCAL;
1088                                        } else {
1089                                                dev_out = neigh->dev;
1090                                        }
1091                                        dev_hold(dev_out);
1092                                        goto select_source;
1093                                }
1094                        }
1095                }
1096
1097                /* Not there? Perhaps its a local address */
1098                if (dev_out == NULL)
1099                        dev_out = dn_dev_get_default();
1100                err = -ENODEV;
1101                if (dev_out == NULL)
1102                        goto out;
1103                dn_db = rcu_dereference_raw(dev_out->dn_ptr);
1104                if (!dn_db)
1105                        goto e_inval;
1106                /* Possible improvement - check all devices for local addr */
1107                if (dn_dev_islocal(dev_out, fld.daddr)) {
1108                        dev_put(dev_out);
1109                        dev_out = init_net.loopback_dev;
1110                        dev_hold(dev_out);
1111                        res.type = RTN_LOCAL;
1112                        goto select_source;
1113                }
1114                /* Not local either.... try sending it to the default router */
1115                neigh = neigh_clone(dn_db->router);
1116                BUG_ON(neigh && neigh->dev != dev_out);
1117
1118                /* Ok then, we assume its directly connected and move on */
1119select_source:
1120                if (neigh)
1121                        gateway = ((struct dn_neigh *)neigh)->addr;
1122                if (gateway == 0)
1123                        gateway = fld.daddr;
1124                if (fld.saddr == 0) {
1125                        fld.saddr = dnet_select_source(dev_out, gateway,
1126                                                       res.type == RTN_LOCAL ?
1127                                                       RT_SCOPE_HOST :
1128                                                       RT_SCOPE_LINK);
1129                        if (fld.saddr == 0 && res.type != RTN_LOCAL)
1130                                goto e_addr;
1131                }
1132                fld.flowidn_oif = dev_out->ifindex;
1133                goto make_route;
1134        }
1135        free_res = 1;
1136
1137        if (res.type == RTN_NAT)
1138                goto e_inval;
1139
1140        if (res.type == RTN_LOCAL) {
1141                if (!fld.saddr)
1142                        fld.saddr = fld.daddr;
1143                if (dev_out)
1144                        dev_put(dev_out);
1145                dev_out = init_net.loopback_dev;
1146                dev_hold(dev_out);
1147                if (!dev_out->dn_ptr)
1148                        goto e_inval;
1149                fld.flowidn_oif = dev_out->ifindex;
1150                if (res.fi)
1151                        dn_fib_info_put(res.fi);
1152                res.fi = NULL;
1153                goto make_route;
1154        }
1155
1156        if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1157                dn_fib_select_multipath(&fld, &res);
1158
1159        /*
1160         * We could add some logic to deal with default routes here and
1161         * get rid of some of the special casing above.
1162         */
1163
1164        if (!fld.saddr)
1165                fld.saddr = DN_FIB_RES_PREFSRC(res);
1166
1167        if (dev_out)
1168                dev_put(dev_out);
1169        dev_out = DN_FIB_RES_DEV(res);
1170        dev_hold(dev_out);
1171        fld.flowidn_oif = dev_out->ifindex;
1172        gateway = DN_FIB_RES_GW(res);
1173
1174make_route:
1175        if (dev_out->flags & IFF_LOOPBACK)
1176                flags |= RTCF_LOCAL;
1177
1178        rt = dst_alloc(&dn_dst_ops, dev_out, 0, DST_OBSOLETE_NONE, 0);
1179        if (rt == NULL)
1180                goto e_nobufs;
1181
1182        rt->dn_next = NULL;
1183        memset(&rt->fld, 0, sizeof(rt->fld));
1184        rt->fld.saddr        = oldflp->saddr;
1185        rt->fld.daddr        = oldflp->daddr;
1186        rt->fld.flowidn_oif  = oldflp->flowidn_oif;
1187        rt->fld.flowidn_iif  = 0;
1188        rt->fld.flowidn_mark = oldflp->flowidn_mark;
1189
1190        rt->rt_saddr      = fld.saddr;
1191        rt->rt_daddr      = fld.daddr;
1192        rt->rt_gateway    = gateway ? gateway : fld.daddr;
1193        rt->rt_local_src  = fld.saddr;
1194
1195        rt->rt_dst_map    = fld.daddr;
1196        rt->rt_src_map    = fld.saddr;
1197
1198        rt->n = neigh;
1199        neigh = NULL;
1200
1201        rt->dst.lastuse = jiffies;
1202        rt->dst.output  = dn_output;
1203        rt->dst.input   = dn_rt_bug;
1204        rt->rt_flags      = flags;
1205        if (flags & RTCF_LOCAL)
1206                rt->dst.input = dn_nsp_rx;
1207
1208        err = dn_rt_set_next_hop(rt, &res);
1209        if (err)
1210                goto e_neighbour;
1211
1212        hash = dn_hash(rt->fld.saddr, rt->fld.daddr);
1213        /* dn_insert_route() increments dst->__refcnt */
1214        dn_insert_route(rt, hash, (struct dn_route **)pprt);
1215
1216done:
1217        if (neigh)
1218                neigh_release(neigh);
1219        if (free_res)
1220                dn_fib_res_put(&res);
1221        if (dev_out)
1222                dev_put(dev_out);
1223out:
1224        return err;
1225
1226e_addr:
1227        err = -EADDRNOTAVAIL;
1228        goto done;
1229e_inval:
1230        err = -EINVAL;
1231        goto done;
1232e_nobufs:
1233        err = -ENOBUFS;
1234        goto done;
1235e_neighbour:
1236        dst_release_immediate(&rt->dst);
1237        goto e_nobufs;
1238}
1239
1240
1241/*
1242 * N.B. The flags may be moved into the flowi at some future stage.
1243 */
1244static int __dn_route_output_key(struct dst_entry **pprt, const struct flowidn *flp, int flags)
1245{
1246        unsigned int hash = dn_hash(flp->saddr, flp->daddr);
1247        struct dn_route *rt = NULL;
1248
1249        if (!(flags & MSG_TRYHARD)) {
1250                rcu_read_lock_bh();
1251                for (rt = rcu_dereference_bh(dn_rt_hash_table[hash].chain); rt;
1252                        rt = rcu_dereference_bh(rt->dn_next)) {
1253                        if ((flp->daddr == rt->fld.daddr) &&
1254                            (flp->saddr == rt->fld.saddr) &&
1255                            (flp->flowidn_mark == rt->fld.flowidn_mark) &&
1256                            dn_is_output_route(rt) &&
1257                            (rt->fld.flowidn_oif == flp->flowidn_oif)) {
1258                                dst_hold_and_use(&rt->dst, jiffies);
1259                                rcu_read_unlock_bh();
1260                                *pprt = &rt->dst;
1261                                return 0;
1262                        }
1263                }
1264                rcu_read_unlock_bh();
1265        }
1266
1267        return dn_route_output_slow(pprt, flp, flags);
1268}
1269
1270static int dn_route_output_key(struct dst_entry **pprt, struct flowidn *flp, int flags)
1271{
1272        int err;
1273
1274        err = __dn_route_output_key(pprt, flp, flags);
1275        if (err == 0 && flp->flowidn_proto) {
1276                *pprt = xfrm_lookup(&init_net, *pprt,
1277                                    flowidn_to_flowi(flp), NULL, 0);
1278                if (IS_ERR(*pprt)) {
1279                        err = PTR_ERR(*pprt);
1280                        *pprt = NULL;
1281                }
1282        }
1283        return err;
1284}
1285
1286int dn_route_output_sock(struct dst_entry __rcu **pprt, struct flowidn *fl, struct sock *sk, int flags)
1287{
1288        int err;
1289
1290        err = __dn_route_output_key(pprt, fl, flags & MSG_TRYHARD);
1291        if (err == 0 && fl->flowidn_proto) {
1292                *pprt = xfrm_lookup(&init_net, *pprt,
1293                                    flowidn_to_flowi(fl), sk, 0);
1294                if (IS_ERR(*pprt)) {
1295                        err = PTR_ERR(*pprt);
1296                        *pprt = NULL;
1297                }
1298        }
1299        return err;
1300}
1301
1302static int dn_route_input_slow(struct sk_buff *skb)
1303{
1304        struct dn_route *rt = NULL;
1305        struct dn_skb_cb *cb = DN_SKB_CB(skb);
1306        struct net_device *in_dev = skb->dev;
1307        struct net_device *out_dev = NULL;
1308        struct dn_dev *dn_db;
1309        struct neighbour *neigh = NULL;
1310        unsigned int hash;
1311        int flags = 0;
1312        __le16 gateway = 0;
1313        __le16 local_src = 0;
1314        struct flowidn fld = {
1315                .daddr = cb->dst,
1316                .saddr = cb->src,
1317                .flowidn_scope = RT_SCOPE_UNIVERSE,
1318                .flowidn_mark = skb->mark,
1319                .flowidn_iif = skb->dev->ifindex,
1320        };
1321        struct dn_fib_res res = { .fi = NULL, .type = RTN_UNREACHABLE };
1322        int err = -EINVAL;
1323        int free_res = 0;
1324
1325        dev_hold(in_dev);
1326
1327        if ((dn_db = rcu_dereference(in_dev->dn_ptr)) == NULL)
1328                goto out;
1329
1330        /* Zero source addresses are not allowed */
1331        if (fld.saddr == 0)
1332                goto out;
1333
1334        /*
1335         * In this case we've just received a packet from a source
1336         * outside ourselves pretending to come from us. We don't
1337         * allow it any further to prevent routing loops, spoofing and
1338         * other nasties. Loopback packets already have the dst attached
1339         * so this only affects packets which have originated elsewhere.
1340         */
1341        err  = -ENOTUNIQ;
1342        if (dn_dev_islocal(in_dev, cb->src))
1343                goto out;
1344
1345        err = dn_fib_lookup(&fld, &res);
1346        if (err) {
1347                if (err != -ESRCH)
1348                        goto out;
1349                /*
1350                 * Is the destination us ?
1351                 */
1352                if (!dn_dev_islocal(in_dev, cb->dst))
1353                        goto e_inval;
1354
1355                res.type = RTN_LOCAL;
1356        } else {
1357                __le16 src_map = fld.saddr;
1358                free_res = 1;
1359
1360                out_dev = DN_FIB_RES_DEV(res);
1361                if (out_dev == NULL) {
1362                        net_crit_ratelimited("Bug in dn_route_input_slow() No output device\n");
1363                        goto e_inval;
1364                }
1365                dev_hold(out_dev);
1366
1367                if (res.r)
1368                        src_map = fld.saddr; /* no NAT support for now */
1369
1370                gateway = DN_FIB_RES_GW(res);
1371                if (res.type == RTN_NAT) {
1372                        fld.daddr = dn_fib_rules_map_destination(fld.daddr, &res);
1373                        dn_fib_res_put(&res);
1374                        free_res = 0;
1375                        if (dn_fib_lookup(&fld, &res))
1376                                goto e_inval;
1377                        free_res = 1;
1378                        if (res.type != RTN_UNICAST)
1379                                goto e_inval;
1380                        flags |= RTCF_DNAT;
1381                        gateway = fld.daddr;
1382                }
1383                fld.saddr = src_map;
1384        }
1385
1386        switch(res.type) {
1387        case RTN_UNICAST:
1388                /*
1389                 * Forwarding check here, we only check for forwarding
1390                 * being turned off, if you want to only forward intra
1391                 * area, its up to you to set the routing tables up
1392                 * correctly.
1393                 */
1394                if (dn_db->parms.forwarding == 0)
1395                        goto e_inval;
1396
1397                if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1398                        dn_fib_select_multipath(&fld, &res);
1399
1400                /*
1401                 * Check for out_dev == in_dev. We use the RTCF_DOREDIRECT
1402                 * flag as a hint to set the intra-ethernet bit when
1403                 * forwarding. If we've got NAT in operation, we don't do
1404                 * this optimisation.
1405                 */
1406                if (out_dev == in_dev && !(flags & RTCF_NAT))
1407                        flags |= RTCF_DOREDIRECT;
1408
1409                local_src = DN_FIB_RES_PREFSRC(res);
1410
1411        case RTN_BLACKHOLE:
1412        case RTN_UNREACHABLE:
1413                break;
1414        case RTN_LOCAL:
1415                flags |= RTCF_LOCAL;
1416                fld.saddr = cb->dst;
1417                fld.daddr = cb->src;
1418
1419                /* Routing tables gave us a gateway */
1420                if (gateway)
1421                        goto make_route;
1422
1423                /* Packet was intra-ethernet, so we know its on-link */
1424                if (cb->rt_flags & DN_RT_F_IE) {
1425                        gateway = cb->src;
1426                        goto make_route;
1427                }
1428
1429                /* Use the default router if there is one */
1430                neigh = neigh_clone(dn_db->router);
1431                if (neigh) {
1432                        gateway = ((struct dn_neigh *)neigh)->addr;
1433                        goto make_route;
1434                }
1435
1436                /* Close eyes and pray */
1437                gateway = cb->src;
1438                goto make_route;
1439        default:
1440                goto e_inval;
1441        }
1442
1443make_route:
1444        rt = dst_alloc(&dn_dst_ops, out_dev, 1, DST_OBSOLETE_NONE, 0);
1445        if (rt == NULL)
1446                goto e_nobufs;
1447
1448        rt->dn_next = NULL;
1449        memset(&rt->fld, 0, sizeof(rt->fld));
1450        rt->rt_saddr      = fld.saddr;
1451        rt->rt_daddr      = fld.daddr;
1452        rt->rt_gateway    = fld.daddr;
1453        if (gateway)
1454                rt->rt_gateway = gateway;
1455        rt->rt_local_src  = local_src ? local_src : rt->rt_saddr;
1456
1457        rt->rt_dst_map    = fld.daddr;
1458        rt->rt_src_map    = fld.saddr;
1459
1460        rt->fld.saddr        = cb->src;
1461        rt->fld.daddr        = cb->dst;
1462        rt->fld.flowidn_oif  = 0;
1463        rt->fld.flowidn_iif  = in_dev->ifindex;
1464        rt->fld.flowidn_mark = fld.flowidn_mark;
1465
1466        rt->n = neigh;
1467        rt->dst.lastuse = jiffies;
1468        rt->dst.output = dn_rt_bug_out;
1469        switch (res.type) {
1470        case RTN_UNICAST:
1471                rt->dst.input = dn_forward;
1472                break;
1473        case RTN_LOCAL:
1474                rt->dst.output = dn_output;
1475                rt->dst.input = dn_nsp_rx;
1476                rt->dst.dev = in_dev;
1477                flags |= RTCF_LOCAL;
1478                break;
1479        default:
1480        case RTN_UNREACHABLE:
1481        case RTN_BLACKHOLE:
1482                rt->dst.input = dst_discard;
1483        }
1484        rt->rt_flags = flags;
1485
1486        err = dn_rt_set_next_hop(rt, &res);
1487        if (err)
1488                goto e_neighbour;
1489
1490        hash = dn_hash(rt->fld.saddr, rt->fld.daddr);
1491        /* dn_insert_route() increments dst->__refcnt */
1492        dn_insert_route(rt, hash, &rt);
1493        skb_dst_set(skb, &rt->dst);
1494
1495done:
1496        if (neigh)
1497                neigh_release(neigh);
1498        if (free_res)
1499                dn_fib_res_put(&res);
1500        dev_put(in_dev);
1501        if (out_dev)
1502                dev_put(out_dev);
1503out:
1504        return err;
1505
1506e_inval:
1507        err = -EINVAL;
1508        goto done;
1509
1510e_nobufs:
1511        err = -ENOBUFS;
1512        goto done;
1513
1514e_neighbour:
1515        dst_release_immediate(&rt->dst);
1516        goto done;
1517}
1518
1519static int dn_route_input(struct sk_buff *skb)
1520{
1521        struct dn_route *rt;
1522        struct dn_skb_cb *cb = DN_SKB_CB(skb);
1523        unsigned int hash = dn_hash(cb->src, cb->dst);
1524
1525        if (skb_dst(skb))
1526                return 0;
1527
1528        rcu_read_lock();
1529        for(rt = rcu_dereference(dn_rt_hash_table[hash].chain); rt != NULL;
1530            rt = rcu_dereference(rt->dn_next)) {
1531                if ((rt->fld.saddr == cb->src) &&
1532                    (rt->fld.daddr == cb->dst) &&
1533                    (rt->fld.flowidn_oif == 0) &&
1534                    (rt->fld.flowidn_mark == skb->mark) &&
1535                    (rt->fld.flowidn_iif == cb->iif)) {
1536                        dst_hold_and_use(&rt->dst, jiffies);
1537                        rcu_read_unlock();
1538                        skb_dst_set(skb, (struct dst_entry *)rt);
1539                        return 0;
1540                }
1541        }
1542        rcu_read_unlock();
1543
1544        return dn_route_input_slow(skb);
1545}
1546
1547static int dn_rt_fill_info(struct sk_buff *skb, u32 portid, u32 seq,
1548                           int event, int nowait, unsigned int flags)
1549{
1550        struct dn_route *rt = (struct dn_route *)skb_dst(skb);
1551        struct rtmsg *r;
1552        struct nlmsghdr *nlh;
1553        long expires;
1554
1555        nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
1556        if (!nlh)
1557                return -EMSGSIZE;
1558
1559        r = nlmsg_data(nlh);
1560        r->rtm_family = AF_DECnet;
1561        r->rtm_dst_len = 16;
1562        r->rtm_src_len = 0;
1563        r->rtm_tos = 0;
1564        r->rtm_table = RT_TABLE_MAIN;
1565        r->rtm_type = rt->rt_type;
1566        r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
1567        r->rtm_scope = RT_SCOPE_UNIVERSE;
1568        r->rtm_protocol = RTPROT_UNSPEC;
1569
1570        if (rt->rt_flags & RTCF_NOTIFY)
1571                r->rtm_flags |= RTM_F_NOTIFY;
1572
1573        if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN) < 0 ||
1574            nla_put_le16(skb, RTA_DST, rt->rt_daddr) < 0)
1575                goto errout;
1576
1577        if (rt->fld.saddr) {
1578                r->rtm_src_len = 16;
1579                if (nla_put_le16(skb, RTA_SRC, rt->fld.saddr) < 0)
1580                        goto errout;
1581        }
1582        if (rt->dst.dev &&
1583            nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex) < 0)
1584                goto errout;
1585
1586        /*
1587         * Note to self - change this if input routes reverse direction when
1588         * they deal only with inputs and not with replies like they do
1589         * currently.
1590         */
1591        if (nla_put_le16(skb, RTA_PREFSRC, rt->rt_local_src) < 0)
1592                goto errout;
1593
1594        if (rt->rt_daddr != rt->rt_gateway &&
1595            nla_put_le16(skb, RTA_GATEWAY, rt->rt_gateway) < 0)
1596                goto errout;
1597
1598        if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
1599                goto errout;
1600
1601        expires = rt->dst.expires ? rt->dst.expires - jiffies : 0;
1602        if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires,
1603                               rt->dst.error) < 0)
1604                goto errout;
1605
1606        if (dn_is_input_route(rt) &&
1607            nla_put_u32(skb, RTA_IIF, rt->fld.flowidn_iif) < 0)
1608                goto errout;
1609
1610        nlmsg_end(skb, nlh);
1611        return 0;
1612
1613errout:
1614        nlmsg_cancel(skb, nlh);
1615        return -EMSGSIZE;
1616}
1617
1618const struct nla_policy rtm_dn_policy[RTA_MAX + 1] = {
1619        [RTA_DST]               = { .type = NLA_U16 },
1620        [RTA_SRC]               = { .type = NLA_U16 },
1621        [RTA_IIF]               = { .type = NLA_U32 },
1622        [RTA_OIF]               = { .type = NLA_U32 },
1623        [RTA_GATEWAY]           = { .type = NLA_U16 },
1624        [RTA_PRIORITY]          = { .type = NLA_U32 },
1625        [RTA_PREFSRC]           = { .type = NLA_U16 },
1626        [RTA_METRICS]           = { .type = NLA_NESTED },
1627        [RTA_MULTIPATH]         = { .type = NLA_NESTED },
1628        [RTA_TABLE]             = { .type = NLA_U32 },
1629        [RTA_MARK]              = { .type = NLA_U32 },
1630};
1631
1632/*
1633 * This is called by both endnodes and routers now.
1634 */
1635static int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
1636                             struct netlink_ext_ack *extack)
1637{
1638        struct net *net = sock_net(in_skb->sk);
1639        struct rtmsg *rtm = nlmsg_data(nlh);
1640        struct dn_route *rt = NULL;
1641        struct dn_skb_cb *cb;
1642        int err;
1643        struct sk_buff *skb;
1644        struct flowidn fld;
1645        struct nlattr *tb[RTA_MAX+1];
1646
1647        if (!net_eq(net, &init_net))
1648                return -EINVAL;
1649
1650        err = nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
1651                                     rtm_dn_policy, extack);
1652        if (err < 0)
1653                return err;
1654
1655        memset(&fld, 0, sizeof(fld));
1656        fld.flowidn_proto = DNPROTO_NSP;
1657
1658        skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1659        if (skb == NULL)
1660                return -ENOBUFS;
1661        skb_reset_mac_header(skb);
1662        cb = DN_SKB_CB(skb);
1663
1664        if (tb[RTA_SRC])
1665                fld.saddr = nla_get_le16(tb[RTA_SRC]);
1666
1667        if (tb[RTA_DST])
1668                fld.daddr = nla_get_le16(tb[RTA_DST]);
1669
1670        if (tb[RTA_IIF])
1671                fld.flowidn_iif = nla_get_u32(tb[RTA_IIF]);
1672
1673        if (fld.flowidn_iif) {
1674                struct net_device *dev;
1675                dev = __dev_get_by_index(&init_net, fld.flowidn_iif);
1676                if (!dev || !dev->dn_ptr) {
1677                        kfree_skb(skb);
1678                        return -ENODEV;
1679                }
1680                skb->protocol = htons(ETH_P_DNA_RT);
1681                skb->dev = dev;
1682                cb->src = fld.saddr;
1683                cb->dst = fld.daddr;
1684                local_bh_disable();
1685                err = dn_route_input(skb);
1686                local_bh_enable();
1687                memset(cb, 0, sizeof(struct dn_skb_cb));
1688                rt = (struct dn_route *)skb_dst(skb);
1689                if (!err && -rt->dst.error)
1690                        err = rt->dst.error;
1691        } else {
1692                if (tb[RTA_OIF])
1693                        fld.flowidn_oif = nla_get_u32(tb[RTA_OIF]);
1694
1695                err = dn_route_output_key((struct dst_entry **)&rt, &fld, 0);
1696        }
1697
1698        skb->dev = NULL;
1699        if (err)
1700                goto out_free;
1701        skb_dst_set(skb, &rt->dst);
1702        if (rtm->rtm_flags & RTM_F_NOTIFY)
1703                rt->rt_flags |= RTCF_NOTIFY;
1704
1705        err = dn_rt_fill_info(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, RTM_NEWROUTE, 0, 0);
1706        if (err < 0) {
1707                err = -EMSGSIZE;
1708                goto out_free;
1709        }
1710
1711        return rtnl_unicast(skb, &init_net, NETLINK_CB(in_skb).portid);
1712
1713out_free:
1714        kfree_skb(skb);
1715        return err;
1716}
1717
1718/*
1719 * For routers, this is called from dn_fib_dump, but for endnodes its
1720 * called directly from the rtnetlink dispatch table.
1721 */
1722int dn_cache_dump(struct sk_buff *skb, struct netlink_callback *cb)
1723{
1724        struct net *net = sock_net(skb->sk);
1725        struct dn_route *rt;
1726        int h, s_h;
1727        int idx, s_idx;
1728        struct rtmsg *rtm;
1729
1730        if (!net_eq(net, &init_net))
1731                return 0;
1732
1733        if (nlmsg_len(cb->nlh) < sizeof(struct rtmsg))
1734                return -EINVAL;
1735
1736        rtm = nlmsg_data(cb->nlh);
1737        if (!(rtm->rtm_flags & RTM_F_CLONED))
1738                return 0;
1739
1740        s_h = cb->args[0];
1741        s_idx = idx = cb->args[1];
1742        for(h = 0; h <= dn_rt_hash_mask; h++) {
1743                if (h < s_h)
1744                        continue;
1745                if (h > s_h)
1746                        s_idx = 0;
1747                rcu_read_lock_bh();
1748                for(rt = rcu_dereference_bh(dn_rt_hash_table[h].chain), idx = 0;
1749                        rt;
1750                        rt = rcu_dereference_bh(rt->dn_next), idx++) {
1751                        if (idx < s_idx)
1752                                continue;
1753                        skb_dst_set(skb, dst_clone(&rt->dst));
1754                        if (dn_rt_fill_info(skb, NETLINK_CB(cb->skb).portid,
1755                                        cb->nlh->nlmsg_seq, RTM_NEWROUTE,
1756                                        1, NLM_F_MULTI) < 0) {
1757                                skb_dst_drop(skb);
1758                                rcu_read_unlock_bh();
1759                                goto done;
1760                        }
1761                        skb_dst_drop(skb);
1762                }
1763                rcu_read_unlock_bh();
1764        }
1765
1766done:
1767        cb->args[0] = h;
1768        cb->args[1] = idx;
1769        return skb->len;
1770}
1771
1772#ifdef CONFIG_PROC_FS
1773struct dn_rt_cache_iter_state {
1774        int bucket;
1775};
1776
1777static struct dn_route *dn_rt_cache_get_first(struct seq_file *seq)
1778{
1779        struct dn_route *rt = NULL;
1780        struct dn_rt_cache_iter_state *s = seq->private;
1781
1782        for(s->bucket = dn_rt_hash_mask; s->bucket >= 0; --s->bucket) {
1783                rcu_read_lock_bh();
1784                rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1785                if (rt)
1786                        break;
1787                rcu_read_unlock_bh();
1788        }
1789        return rt;
1790}
1791
1792static struct dn_route *dn_rt_cache_get_next(struct seq_file *seq, struct dn_route *rt)
1793{
1794        struct dn_rt_cache_iter_state *s = seq->private;
1795
1796        rt = rcu_dereference_bh(rt->dn_next);
1797        while (!rt) {
1798                rcu_read_unlock_bh();
1799                if (--s->bucket < 0)
1800                        break;
1801                rcu_read_lock_bh();
1802                rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1803        }
1804        return rt;
1805}
1806
1807static void *dn_rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
1808{
1809        struct dn_route *rt = dn_rt_cache_get_first(seq);
1810
1811        if (rt) {
1812                while(*pos && (rt = dn_rt_cache_get_next(seq, rt)))
1813                        --*pos;
1814        }
1815        return *pos ? NULL : rt;
1816}
1817
1818static void *dn_rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1819{
1820        struct dn_route *rt = dn_rt_cache_get_next(seq, v);
1821        ++*pos;
1822        return rt;
1823}
1824
1825static void dn_rt_cache_seq_stop(struct seq_file *seq, void *v)
1826{
1827        if (v)
1828                rcu_read_unlock_bh();
1829}
1830
1831static int dn_rt_cache_seq_show(struct seq_file *seq, void *v)
1832{
1833        struct dn_route *rt = v;
1834        char buf1[DN_ASCBUF_LEN], buf2[DN_ASCBUF_LEN];
1835
1836        seq_printf(seq, "%-8s %-7s %-7s %04d %04d %04d\n",
1837                   rt->dst.dev ? rt->dst.dev->name : "*",
1838                   dn_addr2asc(le16_to_cpu(rt->rt_daddr), buf1),
1839                   dn_addr2asc(le16_to_cpu(rt->rt_saddr), buf2),
1840                   atomic_read(&rt->dst.__refcnt),
1841                   rt->dst.__use, 0);
1842        return 0;
1843}
1844
1845static const struct seq_operations dn_rt_cache_seq_ops = {
1846        .start  = dn_rt_cache_seq_start,
1847        .next   = dn_rt_cache_seq_next,
1848        .stop   = dn_rt_cache_seq_stop,
1849        .show   = dn_rt_cache_seq_show,
1850};
1851#endif /* CONFIG_PROC_FS */
1852
1853void __init dn_route_init(void)
1854{
1855        int i, goal, order;
1856
1857        dn_dst_ops.kmem_cachep =
1858                kmem_cache_create("dn_dst_cache", sizeof(struct dn_route), 0,
1859                                  SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
1860        dst_entries_init(&dn_dst_ops);
1861        timer_setup(&dn_route_timer, dn_dst_check_expire, 0);
1862        dn_route_timer.expires = jiffies + decnet_dst_gc_interval * HZ;
1863        add_timer(&dn_route_timer);
1864
1865        goal = totalram_pages() >> (26 - PAGE_SHIFT);
1866
1867        for(order = 0; (1UL << order) < goal; order++)
1868                /* NOTHING */;
1869
1870        /*
1871         * Only want 1024 entries max, since the table is very, very unlikely
1872         * to be larger than that.
1873         */
1874        while(order && ((((1UL << order) * PAGE_SIZE) /
1875                                sizeof(struct dn_rt_hash_bucket)) >= 2048))
1876                order--;
1877
1878        do {
1879                dn_rt_hash_mask = (1UL << order) * PAGE_SIZE /
1880                        sizeof(struct dn_rt_hash_bucket);
1881                while(dn_rt_hash_mask & (dn_rt_hash_mask - 1))
1882                        dn_rt_hash_mask--;
1883                dn_rt_hash_table = (struct dn_rt_hash_bucket *)
1884                        __get_free_pages(GFP_ATOMIC, order);
1885        } while (dn_rt_hash_table == NULL && --order > 0);
1886
1887        if (!dn_rt_hash_table)
1888                panic("Failed to allocate DECnet route cache hash table\n");
1889
1890        printk(KERN_INFO
1891                "DECnet: Routing cache hash table of %u buckets, %ldKbytes\n",
1892                dn_rt_hash_mask,
1893                (long)(dn_rt_hash_mask*sizeof(struct dn_rt_hash_bucket))/1024);
1894
1895        dn_rt_hash_mask--;
1896        for(i = 0; i <= dn_rt_hash_mask; i++) {
1897                spin_lock_init(&dn_rt_hash_table[i].lock);
1898                dn_rt_hash_table[i].chain = NULL;
1899        }
1900
1901        dn_dst_ops.gc_thresh = (dn_rt_hash_mask + 1);
1902
1903        proc_create_seq_private("decnet_cache", 0444, init_net.proc_net,
1904                        &dn_rt_cache_seq_ops,
1905                        sizeof(struct dn_rt_cache_iter_state), NULL);
1906
1907#ifdef CONFIG_DECNET_ROUTER
1908        rtnl_register_module(THIS_MODULE, PF_DECnet, RTM_GETROUTE,
1909                             dn_cache_getroute, dn_fib_dump, 0);
1910#else
1911        rtnl_register_module(THIS_MODULE, PF_DECnet, RTM_GETROUTE,
1912                             dn_cache_getroute, dn_cache_dump, 0);
1913#endif
1914}
1915
1916void __exit dn_route_cleanup(void)
1917{
1918        del_timer(&dn_route_timer);
1919        dn_run_flush(NULL);
1920
1921        remove_proc_entry("decnet_cache", init_net.proc_net);
1922        dst_entries_destroy(&dn_dst_ops);
1923}
1924