linux/net/decnet/dn_route.c
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   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        struct dn_route __rcu *chain;
  89        spinlock_t lock;
  90};
  91
  92extern struct neigh_table dn_neigh_table;
  93
  94
  95static unsigned char dn_hiord_addr[6] = {0xAA, 0x00, 0x04, 0x00, 0x00, 0x00};
  96
  97static const int dn_rt_min_delay = 2 * HZ;
  98static const int dn_rt_max_delay = 10 * HZ;
  99static const int dn_rt_mtu_expires = 10 * 60 * HZ;
 100
 101static unsigned long dn_rt_deadline;
 102
 103static int dn_dst_gc(struct dst_ops *ops);
 104static struct dst_entry *dn_dst_check(struct dst_entry *, __u32);
 105static unsigned int dn_dst_default_advmss(const struct dst_entry *dst);
 106static unsigned int dn_dst_mtu(const struct dst_entry *dst);
 107static void dn_dst_destroy(struct dst_entry *);
 108static void dn_dst_ifdown(struct dst_entry *, struct net_device *dev, int how);
 109static struct dst_entry *dn_dst_negative_advice(struct dst_entry *);
 110static void dn_dst_link_failure(struct sk_buff *);
 111static void dn_dst_update_pmtu(struct dst_entry *dst, struct sock *sk,
 112                               struct sk_buff *skb , u32 mtu,
 113                               bool confirm_neigh);
 114static void dn_dst_redirect(struct dst_entry *dst, struct sock *sk,
 115                            struct sk_buff *skb);
 116static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst,
 117                                             struct sk_buff *skb,
 118                                             const void *daddr);
 119static int dn_route_input(struct sk_buff *);
 120static void dn_run_flush(struct timer_list *unused);
 121
 122static struct dn_rt_hash_bucket *dn_rt_hash_table;
 123static unsigned int dn_rt_hash_mask;
 124
 125static struct timer_list dn_route_timer;
 126static DEFINE_TIMER(dn_rt_flush_timer, dn_run_flush);
 127int decnet_dst_gc_interval = 2;
 128
 129static 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
 146static 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
 155static 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
 169static __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
 178static 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
 211static 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 */
 253static void dn_dst_update_pmtu(struct dst_entry *dst, struct sock *sk,
 254                               struct sk_buff *skb, u32 mtu,
 255                               bool confirm_neigh)
 256{
 257        struct dn_route *rt = (struct dn_route *) dst;
 258        struct neighbour *n = rt->n;
 259        u32 min_mtu = 230;
 260        struct dn_dev *dn;
 261
 262        dn = n ? rcu_dereference_raw(n->dev->dn_ptr) : NULL;
 263
 264        if (dn && dn->use_long == 0)
 265                min_mtu -= 6;
 266        else
 267                min_mtu -= 21;
 268
 269        if (dst_metric(dst, RTAX_MTU) > mtu && mtu >= min_mtu) {
 270                if (!(dst_metric_locked(dst, RTAX_MTU))) {
 271                        dst_metric_set(dst, RTAX_MTU, mtu);
 272                        dst_set_expires(dst, dn_rt_mtu_expires);
 273                }
 274                if (!(dst_metric_locked(dst, RTAX_ADVMSS))) {
 275                        u32 mss = mtu - DN_MAX_NSP_DATA_HEADER;
 276                        u32 existing_mss = dst_metric_raw(dst, RTAX_ADVMSS);
 277                        if (!existing_mss || existing_mss > mss)
 278                                dst_metric_set(dst, RTAX_ADVMSS, mss);
 279                }
 280        }
 281}
 282
 283static void dn_dst_redirect(struct dst_entry *dst, struct sock *sk,
 284                            struct sk_buff *skb)
 285{
 286}
 287
 288/*
 289 * When a route has been marked obsolete. (e.g. routing cache flush)
 290 */
 291static struct dst_entry *dn_dst_check(struct dst_entry *dst, __u32 cookie)
 292{
 293        return NULL;
 294}
 295
 296static struct dst_entry *dn_dst_negative_advice(struct dst_entry *dst)
 297{
 298        dst_release(dst);
 299        return NULL;
 300}
 301
 302static void dn_dst_link_failure(struct sk_buff *skb)
 303{
 304}
 305
 306static inline int compare_keys(struct flowidn *fl1, struct flowidn *fl2)
 307{
 308        return ((fl1->daddr ^ fl2->daddr) |
 309                (fl1->saddr ^ fl2->saddr) |
 310                (fl1->flowidn_mark ^ fl2->flowidn_mark) |
 311                (fl1->flowidn_scope ^ fl2->flowidn_scope) |
 312                (fl1->flowidn_oif ^ fl2->flowidn_oif) |
 313                (fl1->flowidn_iif ^ fl2->flowidn_iif)) == 0;
 314}
 315
 316static int dn_insert_route(struct dn_route *rt, unsigned int hash, struct dn_route **rp)
 317{
 318        struct dn_route *rth;
 319        struct dn_route __rcu **rthp;
 320        unsigned long now = jiffies;
 321
 322        rthp = &dn_rt_hash_table[hash].chain;
 323
 324        spin_lock_bh(&dn_rt_hash_table[hash].lock);
 325        while ((rth = rcu_dereference_protected(*rthp,
 326                                                lockdep_is_held(&dn_rt_hash_table[hash].lock))) != NULL) {
 327                if (compare_keys(&rth->fld, &rt->fld)) {
 328                        /* Put it first */
 329                        *rthp = rth->dn_next;
 330                        rcu_assign_pointer(rth->dn_next,
 331                                           dn_rt_hash_table[hash].chain);
 332                        rcu_assign_pointer(dn_rt_hash_table[hash].chain, rth);
 333
 334                        dst_hold_and_use(&rth->dst, now);
 335                        spin_unlock_bh(&dn_rt_hash_table[hash].lock);
 336
 337                        dst_release_immediate(&rt->dst);
 338                        *rp = rth;
 339                        return 0;
 340                }
 341                rthp = &rth->dn_next;
 342        }
 343
 344        rcu_assign_pointer(rt->dn_next, dn_rt_hash_table[hash].chain);
 345        rcu_assign_pointer(dn_rt_hash_table[hash].chain, rt);
 346
 347        dst_hold_and_use(&rt->dst, now);
 348        spin_unlock_bh(&dn_rt_hash_table[hash].lock);
 349        *rp = rt;
 350        return 0;
 351}
 352
 353static void dn_run_flush(struct timer_list *unused)
 354{
 355        int i;
 356        struct dn_route *rt, *next;
 357
 358        for (i = 0; i < dn_rt_hash_mask; i++) {
 359                spin_lock_bh(&dn_rt_hash_table[i].lock);
 360
 361                rt = xchg((struct dn_route **)&dn_rt_hash_table[i].chain, NULL);
 362                if (!rt)
 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        skb = skb_unshare(skb, GFP_ATOMIC);
 429        if (!skb)
 430                return NET_RX_DROP;
 431
 432        cb = DN_SKB_CB(skb);
 433        /* Skip packet length and point to flags */
 434        ptr = skb->data + 2;
 435        *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
 436
 437        dst = (__le16 *)ptr;
 438        ptr += 2;
 439        src = (__le16 *)ptr;
 440        ptr += 2;
 441        *ptr = 0; /* Zero hop count */
 442
 443        swap(*src, *dst);
 444
 445        skb->pkt_type = PACKET_OUTGOING;
 446        dn_rt_finish_output(skb, NULL, NULL);
 447        return NET_RX_SUCCESS;
 448}
 449
 450/**
 451 * dn_return_long - Return a long packet to its sender
 452 * @skb: The long format packet to return
 453 *
 454 */
 455static int dn_return_long(struct sk_buff *skb)
 456{
 457        struct dn_skb_cb *cb;
 458        unsigned char *ptr;
 459        unsigned char *src_addr, *dst_addr;
 460        unsigned char tmp[ETH_ALEN];
 461
 462        /* Add back all headers */
 463        skb_push(skb, skb->data - skb_network_header(skb));
 464
 465        skb = skb_unshare(skb, GFP_ATOMIC);
 466        if (!skb)
 467                return NET_RX_DROP;
 468
 469        cb = DN_SKB_CB(skb);
 470        /* Ignore packet length and point to flags */
 471        ptr = skb->data + 2;
 472
 473        /* Skip padding */
 474        if (*ptr & DN_RT_F_PF) {
 475                char padlen = (*ptr & ~DN_RT_F_PF);
 476                ptr += padlen;
 477        }
 478
 479        *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
 480        ptr += 2;
 481        dst_addr = ptr;
 482        ptr += 8;
 483        src_addr = ptr;
 484        ptr += 6;
 485        *ptr = 0; /* Zero hop count */
 486
 487        /* Swap source and destination */
 488        memcpy(tmp, src_addr, ETH_ALEN);
 489        memcpy(src_addr, dst_addr, ETH_ALEN);
 490        memcpy(dst_addr, tmp, ETH_ALEN);
 491
 492        skb->pkt_type = PACKET_OUTGOING;
 493        dn_rt_finish_output(skb, dst_addr, src_addr);
 494        return NET_RX_SUCCESS;
 495}
 496
 497/**
 498 * dn_route_rx_packet - Try and find a route for an incoming packet
 499 * @net: The applicable net namespace
 500 * @sk: Socket packet transmitted on
 501 * @skb: The packet to find a route for
 502 *
 503 * Returns: result of input function if route is found, error code otherwise
 504 */
 505static int dn_route_rx_packet(struct net *net, struct sock *sk, struct sk_buff *skb)
 506{
 507        struct dn_skb_cb *cb;
 508        int err;
 509
 510        err = dn_route_input(skb);
 511        if (err == 0)
 512                return dst_input(skb);
 513
 514        cb = DN_SKB_CB(skb);
 515        if (decnet_debug_level & 4) {
 516                char *devname = skb->dev ? skb->dev->name : "???";
 517
 518                printk(KERN_DEBUG
 519                        "DECnet: dn_route_rx_packet: rt_flags=0x%02x dev=%s len=%d src=0x%04hx dst=0x%04hx err=%d type=%d\n",
 520                        (int)cb->rt_flags, devname, skb->len,
 521                        le16_to_cpu(cb->src), le16_to_cpu(cb->dst),
 522                        err, skb->pkt_type);
 523        }
 524
 525        if ((skb->pkt_type == PACKET_HOST) && (cb->rt_flags & DN_RT_F_RQR)) {
 526                switch (cb->rt_flags & DN_RT_PKT_MSK) {
 527                case DN_RT_PKT_SHORT:
 528                        return dn_return_short(skb);
 529                case DN_RT_PKT_LONG:
 530                        return dn_return_long(skb);
 531                }
 532        }
 533
 534        kfree_skb(skb);
 535        return NET_RX_DROP;
 536}
 537
 538static int dn_route_rx_long(struct sk_buff *skb)
 539{
 540        struct dn_skb_cb *cb = DN_SKB_CB(skb);
 541        unsigned char *ptr = skb->data;
 542
 543        if (!pskb_may_pull(skb, 21)) /* 20 for long header, 1 for shortest nsp */
 544                goto drop_it;
 545
 546        skb_pull(skb, 20);
 547        skb_reset_transport_header(skb);
 548
 549        /* Destination info */
 550        ptr += 2;
 551        cb->dst = dn_eth2dn(ptr);
 552        if (memcmp(ptr, dn_hiord_addr, 4) != 0)
 553                goto drop_it;
 554        ptr += 6;
 555
 556
 557        /* Source info */
 558        ptr += 2;
 559        cb->src = dn_eth2dn(ptr);
 560        if (memcmp(ptr, dn_hiord_addr, 4) != 0)
 561                goto drop_it;
 562        ptr += 6;
 563        /* Other junk */
 564        ptr++;
 565        cb->hops = *ptr++; /* Visit Count */
 566
 567        return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING,
 568                       &init_net, NULL, skb, skb->dev, NULL,
 569                       dn_route_rx_packet);
 570
 571drop_it:
 572        kfree_skb(skb);
 573        return NET_RX_DROP;
 574}
 575
 576
 577
 578static int dn_route_rx_short(struct sk_buff *skb)
 579{
 580        struct dn_skb_cb *cb = DN_SKB_CB(skb);
 581        unsigned char *ptr = skb->data;
 582
 583        if (!pskb_may_pull(skb, 6)) /* 5 for short header + 1 for shortest nsp */
 584                goto drop_it;
 585
 586        skb_pull(skb, 5);
 587        skb_reset_transport_header(skb);
 588
 589        cb->dst = *(__le16 *)ptr;
 590        ptr += 2;
 591        cb->src = *(__le16 *)ptr;
 592        ptr += 2;
 593        cb->hops = *ptr & 0x3f;
 594
 595        return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING,
 596                       &init_net, NULL, skb, skb->dev, NULL,
 597                       dn_route_rx_packet);
 598
 599drop_it:
 600        kfree_skb(skb);
 601        return NET_RX_DROP;
 602}
 603
 604static int dn_route_discard(struct net *net, struct sock *sk, struct sk_buff *skb)
 605{
 606        /*
 607         * I know we drop the packet here, but that's considered success in
 608         * this case
 609         */
 610        kfree_skb(skb);
 611        return NET_RX_SUCCESS;
 612}
 613
 614static int dn_route_ptp_hello(struct net *net, struct sock *sk, struct sk_buff *skb)
 615{
 616        dn_dev_hello(skb);
 617        dn_neigh_pointopoint_hello(skb);
 618        return NET_RX_SUCCESS;
 619}
 620
 621int dn_route_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
 622{
 623        struct dn_skb_cb *cb;
 624        unsigned char flags = 0;
 625        __u16 len = le16_to_cpu(*(__le16 *)skb->data);
 626        struct dn_dev *dn = rcu_dereference(dev->dn_ptr);
 627        unsigned char padlen = 0;
 628
 629        if (!net_eq(dev_net(dev), &init_net))
 630                goto dump_it;
 631
 632        if (dn == NULL)
 633                goto dump_it;
 634
 635        skb = skb_share_check(skb, GFP_ATOMIC);
 636        if (!skb)
 637                goto out;
 638
 639        if (!pskb_may_pull(skb, 3))
 640                goto dump_it;
 641
 642        skb_pull(skb, 2);
 643
 644        if (len > skb->len)
 645                goto dump_it;
 646
 647        skb_trim(skb, len);
 648
 649        flags = *skb->data;
 650
 651        cb = DN_SKB_CB(skb);
 652        cb->stamp = jiffies;
 653        cb->iif = dev->ifindex;
 654
 655        /*
 656         * If we have padding, remove it.
 657         */
 658        if (flags & DN_RT_F_PF) {
 659                padlen = flags & ~DN_RT_F_PF;
 660                if (!pskb_may_pull(skb, padlen + 1))
 661                        goto dump_it;
 662                skb_pull(skb, padlen);
 663                flags = *skb->data;
 664        }
 665
 666        skb_reset_network_header(skb);
 667
 668        /*
 669         * Weed out future version DECnet
 670         */
 671        if (flags & DN_RT_F_VER)
 672                goto dump_it;
 673
 674        cb->rt_flags = flags;
 675
 676        if (decnet_debug_level & 1)
 677                printk(KERN_DEBUG
 678                        "dn_route_rcv: got 0x%02x from %s [%d %d %d]\n",
 679                        (int)flags, dev->name, len, skb->len,
 680                        padlen);
 681
 682        if (flags & DN_RT_PKT_CNTL) {
 683                if (unlikely(skb_linearize(skb)))
 684                        goto dump_it;
 685
 686                switch (flags & DN_RT_CNTL_MSK) {
 687                case DN_RT_PKT_INIT:
 688                        dn_dev_init_pkt(skb);
 689                        break;
 690                case DN_RT_PKT_VERI:
 691                        dn_dev_veri_pkt(skb);
 692                        break;
 693                }
 694
 695                if (dn->parms.state != DN_DEV_S_RU)
 696                        goto dump_it;
 697
 698                switch (flags & DN_RT_CNTL_MSK) {
 699                case DN_RT_PKT_HELO:
 700                        return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
 701                                       &init_net, NULL, skb, skb->dev, NULL,
 702                                       dn_route_ptp_hello);
 703
 704                case DN_RT_PKT_L1RT:
 705                case DN_RT_PKT_L2RT:
 706                        return NF_HOOK(NFPROTO_DECNET, NF_DN_ROUTE,
 707                                       &init_net, NULL, skb, skb->dev, NULL,
 708                                       dn_route_discard);
 709                case DN_RT_PKT_ERTH:
 710                        return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
 711                                       &init_net, NULL, skb, skb->dev, NULL,
 712                                       dn_neigh_router_hello);
 713
 714                case DN_RT_PKT_EEDH:
 715                        return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
 716                                       &init_net, NULL, skb, skb->dev, NULL,
 717                                       dn_neigh_endnode_hello);
 718                }
 719        } else {
 720                if (dn->parms.state != DN_DEV_S_RU)
 721                        goto dump_it;
 722
 723                skb_pull(skb, 1); /* Pull flags */
 724
 725                switch (flags & DN_RT_PKT_MSK) {
 726                case DN_RT_PKT_LONG:
 727                        return dn_route_rx_long(skb);
 728                case DN_RT_PKT_SHORT:
 729                        return dn_route_rx_short(skb);
 730                }
 731        }
 732
 733dump_it:
 734        kfree_skb(skb);
 735out:
 736        return NET_RX_DROP;
 737}
 738
 739static int dn_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 740{
 741        struct dst_entry *dst = skb_dst(skb);
 742        struct dn_route *rt = (struct dn_route *)dst;
 743        struct net_device *dev = dst->dev;
 744        struct dn_skb_cb *cb = DN_SKB_CB(skb);
 745
 746        int err = -EINVAL;
 747
 748        if (rt->n == NULL)
 749                goto error;
 750
 751        skb->dev = dev;
 752
 753        cb->src = rt->rt_saddr;
 754        cb->dst = rt->rt_daddr;
 755
 756        /*
 757         * Always set the Intra-Ethernet bit on all outgoing packets
 758         * originated on this node. Only valid flag from upper layers
 759         * is return-to-sender-requested. Set hop count to 0 too.
 760         */
 761        cb->rt_flags &= ~DN_RT_F_RQR;
 762        cb->rt_flags |= DN_RT_F_IE;
 763        cb->hops = 0;
 764
 765        return NF_HOOK(NFPROTO_DECNET, NF_DN_LOCAL_OUT,
 766                       &init_net, sk, skb, NULL, dev,
 767                       dn_to_neigh_output);
 768
 769error:
 770        net_dbg_ratelimited("dn_output: This should not happen\n");
 771
 772        kfree_skb(skb);
 773
 774        return err;
 775}
 776
 777static int dn_forward(struct sk_buff *skb)
 778{
 779        struct dn_skb_cb *cb = DN_SKB_CB(skb);
 780        struct dst_entry *dst = skb_dst(skb);
 781        struct dn_dev *dn_db = rcu_dereference(dst->dev->dn_ptr);
 782        struct dn_route *rt;
 783        int header_len;
 784        struct net_device *dev = skb->dev;
 785
 786        if (skb->pkt_type != PACKET_HOST)
 787                goto drop;
 788
 789        /* Ensure that we have enough space for headers */
 790        rt = (struct dn_route *)skb_dst(skb);
 791        header_len = dn_db->use_long ? 21 : 6;
 792        if (skb_cow(skb, LL_RESERVED_SPACE(rt->dst.dev)+header_len))
 793                goto drop;
 794
 795        /*
 796         * Hop count exceeded.
 797         */
 798        if (++cb->hops > 30)
 799                goto drop;
 800
 801        skb->dev = rt->dst.dev;
 802
 803        /*
 804         * If packet goes out same interface it came in on, then set
 805         * the Intra-Ethernet bit. This has no effect for short
 806         * packets, so we don't need to test for them here.
 807         */
 808        cb->rt_flags &= ~DN_RT_F_IE;
 809        if (rt->rt_flags & RTCF_DOREDIRECT)
 810                cb->rt_flags |= DN_RT_F_IE;
 811
 812        return NF_HOOK(NFPROTO_DECNET, NF_DN_FORWARD,
 813                       &init_net, NULL, skb, dev, skb->dev,
 814                       dn_to_neigh_output);
 815
 816drop:
 817        kfree_skb(skb);
 818        return NET_RX_DROP;
 819}
 820
 821/*
 822 * Used to catch bugs. This should never normally get
 823 * called.
 824 */
 825static int dn_rt_bug_out(struct net *net, struct sock *sk, struct sk_buff *skb)
 826{
 827        struct dn_skb_cb *cb = DN_SKB_CB(skb);
 828
 829        net_dbg_ratelimited("dn_rt_bug: skb from:%04x to:%04x\n",
 830                            le16_to_cpu(cb->src), le16_to_cpu(cb->dst));
 831
 832        kfree_skb(skb);
 833
 834        return NET_RX_DROP;
 835}
 836
 837static int dn_rt_bug(struct sk_buff *skb)
 838{
 839        struct dn_skb_cb *cb = DN_SKB_CB(skb);
 840
 841        net_dbg_ratelimited("dn_rt_bug: skb from:%04x to:%04x\n",
 842                            le16_to_cpu(cb->src), le16_to_cpu(cb->dst));
 843
 844        kfree_skb(skb);
 845
 846        return NET_RX_DROP;
 847}
 848
 849static unsigned int dn_dst_default_advmss(const struct dst_entry *dst)
 850{
 851        return dn_mss_from_pmtu(dst->dev, dst_mtu(dst));
 852}
 853
 854static unsigned int dn_dst_mtu(const struct dst_entry *dst)
 855{
 856        unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
 857
 858        return mtu ? : dst->dev->mtu;
 859}
 860
 861static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst,
 862                                             struct sk_buff *skb,
 863                                             const void *daddr)
 864{
 865        return __neigh_lookup_errno(&dn_neigh_table, daddr, dst->dev);
 866}
 867
 868static int dn_rt_set_next_hop(struct dn_route *rt, struct dn_fib_res *res)
 869{
 870        struct dn_fib_info *fi = res->fi;
 871        struct net_device *dev = rt->dst.dev;
 872        unsigned int mss_metric;
 873        struct neighbour *n;
 874
 875        if (fi) {
 876                if (DN_FIB_RES_GW(*res) &&
 877                    DN_FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
 878                        rt->rt_gateway = DN_FIB_RES_GW(*res);
 879                dst_init_metrics(&rt->dst, fi->fib_metrics, true);
 880        }
 881        rt->rt_type = res->type;
 882
 883        if (dev != NULL && rt->n == NULL) {
 884                n = __neigh_lookup_errno(&dn_neigh_table, &rt->rt_gateway, dev);
 885                if (IS_ERR(n))
 886                        return PTR_ERR(n);
 887                rt->n = n;
 888        }
 889
 890        if (dst_metric(&rt->dst, RTAX_MTU) > rt->dst.dev->mtu)
 891                dst_metric_set(&rt->dst, RTAX_MTU, rt->dst.dev->mtu);
 892        mss_metric = dst_metric_raw(&rt->dst, RTAX_ADVMSS);
 893        if (mss_metric) {
 894                unsigned int mss = dn_mss_from_pmtu(dev, dst_mtu(&rt->dst));
 895                if (mss_metric > mss)
 896                        dst_metric_set(&rt->dst, RTAX_ADVMSS, mss);
 897        }
 898        return 0;
 899}
 900
 901static inline int dn_match_addr(__le16 addr1, __le16 addr2)
 902{
 903        __u16 tmp = le16_to_cpu(addr1) ^ le16_to_cpu(addr2);
 904        int match = 16;
 905        while (tmp) {
 906                tmp >>= 1;
 907                match--;
 908        }
 909        return match;
 910}
 911
 912static __le16 dnet_select_source(const struct net_device *dev, __le16 daddr, int scope)
 913{
 914        __le16 saddr = 0;
 915        struct dn_dev *dn_db;
 916        struct dn_ifaddr *ifa;
 917        int best_match = 0;
 918        int ret;
 919
 920        rcu_read_lock();
 921        dn_db = rcu_dereference(dev->dn_ptr);
 922        for (ifa = rcu_dereference(dn_db->ifa_list);
 923             ifa != NULL;
 924             ifa = rcu_dereference(ifa->ifa_next)) {
 925                if (ifa->ifa_scope > scope)
 926                        continue;
 927                if (!daddr) {
 928                        saddr = ifa->ifa_local;
 929                        break;
 930                }
 931                ret = dn_match_addr(daddr, ifa->ifa_local);
 932                if (ret > best_match)
 933                        saddr = ifa->ifa_local;
 934                if (best_match == 0)
 935                        saddr = ifa->ifa_local;
 936        }
 937        rcu_read_unlock();
 938
 939        return saddr;
 940}
 941
 942static inline __le16 __dn_fib_res_prefsrc(struct dn_fib_res *res)
 943{
 944        return dnet_select_source(DN_FIB_RES_DEV(*res), DN_FIB_RES_GW(*res), res->scope);
 945}
 946
 947static inline __le16 dn_fib_rules_map_destination(__le16 daddr, struct dn_fib_res *res)
 948{
 949        __le16 mask = dnet_make_mask(res->prefixlen);
 950        return (daddr&~mask)|res->fi->fib_nh->nh_gw;
 951}
 952
 953static int dn_route_output_slow(struct dst_entry **pprt, const struct flowidn *oldflp, int try_hard)
 954{
 955        struct flowidn fld = {
 956                .daddr = oldflp->daddr,
 957                .saddr = oldflp->saddr,
 958                .flowidn_scope = RT_SCOPE_UNIVERSE,
 959                .flowidn_mark = oldflp->flowidn_mark,
 960                .flowidn_iif = LOOPBACK_IFINDEX,
 961                .flowidn_oif = oldflp->flowidn_oif,
 962        };
 963        struct dn_route *rt = NULL;
 964        struct net_device *dev_out = NULL, *dev;
 965        struct neighbour *neigh = NULL;
 966        unsigned int hash;
 967        unsigned int flags = 0;
 968        struct dn_fib_res res = { .fi = NULL, .type = RTN_UNICAST };
 969        int err;
 970        int free_res = 0;
 971        __le16 gateway = 0;
 972
 973        if (decnet_debug_level & 16)
 974                printk(KERN_DEBUG
 975                       "dn_route_output_slow: dst=%04x src=%04x mark=%d"
 976                       " iif=%d oif=%d\n", le16_to_cpu(oldflp->daddr),
 977                       le16_to_cpu(oldflp->saddr),
 978                       oldflp->flowidn_mark, LOOPBACK_IFINDEX,
 979                       oldflp->flowidn_oif);
 980
 981        /* If we have an output interface, verify its a DECnet device */
 982        if (oldflp->flowidn_oif) {
 983                dev_out = dev_get_by_index(&init_net, oldflp->flowidn_oif);
 984                err = -ENODEV;
 985                if (dev_out && dev_out->dn_ptr == NULL) {
 986                        dev_put(dev_out);
 987                        dev_out = NULL;
 988                }
 989                if (dev_out == NULL)
 990                        goto out;
 991        }
 992
 993        /* If we have a source address, verify that its a local address */
 994        if (oldflp->saddr) {
 995                err = -EADDRNOTAVAIL;
 996
 997                if (dev_out) {
 998                        if (dn_dev_islocal(dev_out, oldflp->saddr))
 999                                goto source_ok;
1000                        dev_put(dev_out);
1001                        goto out;
1002                }
1003                rcu_read_lock();
1004                for_each_netdev_rcu(&init_net, dev) {
1005                        if (!dev->dn_ptr)
1006                                continue;
1007                        if (!dn_dev_islocal(dev, oldflp->saddr))
1008                                continue;
1009                        if ((dev->flags & IFF_LOOPBACK) &&
1010                            oldflp->daddr &&
1011                            !dn_dev_islocal(dev, oldflp->daddr))
1012                                continue;
1013
1014                        dev_out = dev;
1015                        break;
1016                }
1017                rcu_read_unlock();
1018                if (dev_out == NULL)
1019                        goto out;
1020                dev_hold(dev_out);
1021source_ok:
1022                ;
1023        }
1024
1025        /* No destination? Assume its local */
1026        if (!fld.daddr) {
1027                fld.daddr = fld.saddr;
1028
1029                if (dev_out)
1030                        dev_put(dev_out);
1031                err = -EINVAL;
1032                dev_out = init_net.loopback_dev;
1033                if (!dev_out->dn_ptr)
1034                        goto out;
1035                err = -EADDRNOTAVAIL;
1036                dev_hold(dev_out);
1037                if (!fld.daddr) {
1038                        fld.daddr =
1039                        fld.saddr = dnet_select_source(dev_out, 0,
1040                                                       RT_SCOPE_HOST);
1041                        if (!fld.daddr)
1042                                goto done;
1043                }
1044                fld.flowidn_oif = LOOPBACK_IFINDEX;
1045                res.type = RTN_LOCAL;
1046                goto make_route;
1047        }
1048
1049        if (decnet_debug_level & 16)
1050                printk(KERN_DEBUG
1051                       "dn_route_output_slow: initial checks complete."
1052                       " dst=%04x src=%04x oif=%d try_hard=%d\n",
1053                       le16_to_cpu(fld.daddr), le16_to_cpu(fld.saddr),
1054                       fld.flowidn_oif, try_hard);
1055
1056        /*
1057         * N.B. If the kernel is compiled without router support then
1058         * dn_fib_lookup() will evaluate to non-zero so this if () block
1059         * will always be executed.
1060         */
1061        err = -ESRCH;
1062        if (try_hard || (err = dn_fib_lookup(&fld, &res)) != 0) {
1063                struct dn_dev *dn_db;
1064                if (err != -ESRCH)
1065                        goto out;
1066                /*
1067                 * Here the fallback is basically the standard algorithm for
1068                 * routing in endnodes which is described in the DECnet routing
1069                 * docs
1070                 *
1071                 * If we are not trying hard, look in neighbour cache.
1072                 * The result is tested to ensure that if a specific output
1073                 * device/source address was requested, then we honour that
1074                 * here
1075                 */
1076                if (!try_hard) {
1077                        neigh = neigh_lookup_nodev(&dn_neigh_table, &init_net, &fld.daddr);
1078                        if (neigh) {
1079                                if ((oldflp->flowidn_oif &&
1080                                    (neigh->dev->ifindex != oldflp->flowidn_oif)) ||
1081                                    (oldflp->saddr &&
1082                                    (!dn_dev_islocal(neigh->dev,
1083                                                     oldflp->saddr)))) {
1084                                        neigh_release(neigh);
1085                                        neigh = NULL;
1086                                } else {
1087                                        if (dev_out)
1088                                                dev_put(dev_out);
1089                                        if (dn_dev_islocal(neigh->dev, fld.daddr)) {
1090                                                dev_out = init_net.loopback_dev;
1091                                                res.type = RTN_LOCAL;
1092                                        } else {
1093                                                dev_out = neigh->dev;
1094                                        }
1095                                        dev_hold(dev_out);
1096                                        goto select_source;
1097                                }
1098                        }
1099                }
1100
1101                /* Not there? Perhaps its a local address */
1102                if (dev_out == NULL)
1103                        dev_out = dn_dev_get_default();
1104                err = -ENODEV;
1105                if (dev_out == NULL)
1106                        goto out;
1107                dn_db = rcu_dereference_raw(dev_out->dn_ptr);
1108                if (!dn_db)
1109                        goto e_inval;
1110                /* Possible improvement - check all devices for local addr */
1111                if (dn_dev_islocal(dev_out, fld.daddr)) {
1112                        dev_put(dev_out);
1113                        dev_out = init_net.loopback_dev;
1114                        dev_hold(dev_out);
1115                        res.type = RTN_LOCAL;
1116                        goto select_source;
1117                }
1118                /* Not local either.... try sending it to the default router */
1119                neigh = neigh_clone(dn_db->router);
1120                BUG_ON(neigh && neigh->dev != dev_out);
1121
1122                /* Ok then, we assume its directly connected and move on */
1123select_source:
1124                if (neigh)
1125                        gateway = ((struct dn_neigh *)neigh)->addr;
1126                if (gateway == 0)
1127                        gateway = fld.daddr;
1128                if (fld.saddr == 0) {
1129                        fld.saddr = dnet_select_source(dev_out, gateway,
1130                                                       res.type == RTN_LOCAL ?
1131                                                       RT_SCOPE_HOST :
1132                                                       RT_SCOPE_LINK);
1133                        if (fld.saddr == 0 && res.type != RTN_LOCAL)
1134                                goto e_addr;
1135                }
1136                fld.flowidn_oif = dev_out->ifindex;
1137                goto make_route;
1138        }
1139        free_res = 1;
1140
1141        if (res.type == RTN_NAT)
1142                goto e_inval;
1143
1144        if (res.type == RTN_LOCAL) {
1145                if (!fld.saddr)
1146                        fld.saddr = fld.daddr;
1147                if (dev_out)
1148                        dev_put(dev_out);
1149                dev_out = init_net.loopback_dev;
1150                dev_hold(dev_out);
1151                if (!dev_out->dn_ptr)
1152                        goto e_inval;
1153                fld.flowidn_oif = dev_out->ifindex;
1154                if (res.fi)
1155                        dn_fib_info_put(res.fi);
1156                res.fi = NULL;
1157                goto make_route;
1158        }
1159
1160        if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1161                dn_fib_select_multipath(&fld, &res);
1162
1163        /*
1164         * We could add some logic to deal with default routes here and
1165         * get rid of some of the special casing above.
1166         */
1167
1168        if (!fld.saddr)
1169                fld.saddr = DN_FIB_RES_PREFSRC(res);
1170
1171        if (dev_out)
1172                dev_put(dev_out);
1173        dev_out = DN_FIB_RES_DEV(res);
1174        dev_hold(dev_out);
1175        fld.flowidn_oif = dev_out->ifindex;
1176        gateway = DN_FIB_RES_GW(res);
1177
1178make_route:
1179        if (dev_out->flags & IFF_LOOPBACK)
1180                flags |= RTCF_LOCAL;
1181
1182        rt = dst_alloc(&dn_dst_ops, dev_out, 0, DST_OBSOLETE_NONE, 0);
1183        if (rt == NULL)
1184                goto e_nobufs;
1185
1186        rt->dn_next = NULL;
1187        memset(&rt->fld, 0, sizeof(rt->fld));
1188        rt->fld.saddr        = oldflp->saddr;
1189        rt->fld.daddr        = oldflp->daddr;
1190        rt->fld.flowidn_oif  = oldflp->flowidn_oif;
1191        rt->fld.flowidn_iif  = 0;
1192        rt->fld.flowidn_mark = oldflp->flowidn_mark;
1193
1194        rt->rt_saddr      = fld.saddr;
1195        rt->rt_daddr      = fld.daddr;
1196        rt->rt_gateway    = gateway ? gateway : fld.daddr;
1197        rt->rt_local_src  = fld.saddr;
1198
1199        rt->rt_dst_map    = fld.daddr;
1200        rt->rt_src_map    = fld.saddr;
1201
1202        rt->n = neigh;
1203        neigh = NULL;
1204
1205        rt->dst.lastuse = jiffies;
1206        rt->dst.output  = dn_output;
1207        rt->dst.input   = dn_rt_bug;
1208        rt->rt_flags      = flags;
1209        if (flags & RTCF_LOCAL)
1210                rt->dst.input = dn_nsp_rx;
1211
1212        err = dn_rt_set_next_hop(rt, &res);
1213        if (err)
1214                goto e_neighbour;
1215
1216        hash = dn_hash(rt->fld.saddr, rt->fld.daddr);
1217        /* dn_insert_route() increments dst->__refcnt */
1218        dn_insert_route(rt, hash, (struct dn_route **)pprt);
1219
1220done:
1221        if (neigh)
1222                neigh_release(neigh);
1223        if (free_res)
1224                dn_fib_res_put(&res);
1225        if (dev_out)
1226                dev_put(dev_out);
1227out:
1228        return err;
1229
1230e_addr:
1231        err = -EADDRNOTAVAIL;
1232        goto done;
1233e_inval:
1234        err = -EINVAL;
1235        goto done;
1236e_nobufs:
1237        err = -ENOBUFS;
1238        goto done;
1239e_neighbour:
1240        dst_release_immediate(&rt->dst);
1241        goto e_nobufs;
1242}
1243
1244
1245/*
1246 * N.B. The flags may be moved into the flowi at some future stage.
1247 */
1248static int __dn_route_output_key(struct dst_entry **pprt, const struct flowidn *flp, int flags)
1249{
1250        unsigned int hash = dn_hash(flp->saddr, flp->daddr);
1251        struct dn_route *rt = NULL;
1252
1253        if (!(flags & MSG_TRYHARD)) {
1254                rcu_read_lock_bh();
1255                for (rt = rcu_dereference_bh(dn_rt_hash_table[hash].chain); rt;
1256                        rt = rcu_dereference_bh(rt->dn_next)) {
1257                        if ((flp->daddr == rt->fld.daddr) &&
1258                            (flp->saddr == rt->fld.saddr) &&
1259                            (flp->flowidn_mark == rt->fld.flowidn_mark) &&
1260                            dn_is_output_route(rt) &&
1261                            (rt->fld.flowidn_oif == flp->flowidn_oif)) {
1262                                dst_hold_and_use(&rt->dst, jiffies);
1263                                rcu_read_unlock_bh();
1264                                *pprt = &rt->dst;
1265                                return 0;
1266                        }
1267                }
1268                rcu_read_unlock_bh();
1269        }
1270
1271        return dn_route_output_slow(pprt, flp, flags);
1272}
1273
1274static int dn_route_output_key(struct dst_entry **pprt, struct flowidn *flp, int flags)
1275{
1276        int err;
1277
1278        err = __dn_route_output_key(pprt, flp, flags);
1279        if (err == 0 && flp->flowidn_proto) {
1280                *pprt = xfrm_lookup(&init_net, *pprt,
1281                                    flowidn_to_flowi(flp), NULL, 0);
1282                if (IS_ERR(*pprt)) {
1283                        err = PTR_ERR(*pprt);
1284                        *pprt = NULL;
1285                }
1286        }
1287        return err;
1288}
1289
1290int dn_route_output_sock(struct dst_entry __rcu **pprt, struct flowidn *fl, struct sock *sk, int flags)
1291{
1292        int err;
1293
1294        err = __dn_route_output_key(pprt, fl, flags & MSG_TRYHARD);
1295        if (err == 0 && fl->flowidn_proto) {
1296                *pprt = xfrm_lookup(&init_net, *pprt,
1297                                    flowidn_to_flowi(fl), sk, 0);
1298                if (IS_ERR(*pprt)) {
1299                        err = PTR_ERR(*pprt);
1300                        *pprt = NULL;
1301                }
1302        }
1303        return err;
1304}
1305
1306static int dn_route_input_slow(struct sk_buff *skb)
1307{
1308        struct dn_route *rt = NULL;
1309        struct dn_skb_cb *cb = DN_SKB_CB(skb);
1310        struct net_device *in_dev = skb->dev;
1311        struct net_device *out_dev = NULL;
1312        struct dn_dev *dn_db;
1313        struct neighbour *neigh = NULL;
1314        unsigned int hash;
1315        int flags = 0;
1316        __le16 gateway = 0;
1317        __le16 local_src = 0;
1318        struct flowidn fld = {
1319                .daddr = cb->dst,
1320                .saddr = cb->src,
1321                .flowidn_scope = RT_SCOPE_UNIVERSE,
1322                .flowidn_mark = skb->mark,
1323                .flowidn_iif = skb->dev->ifindex,
1324        };
1325        struct dn_fib_res res = { .fi = NULL, .type = RTN_UNREACHABLE };
1326        int err = -EINVAL;
1327        int free_res = 0;
1328
1329        dev_hold(in_dev);
1330
1331        dn_db = rcu_dereference(in_dev->dn_ptr);
1332        if (!dn_db)
1333                goto out;
1334
1335        /* Zero source addresses are not allowed */
1336        if (fld.saddr == 0)
1337                goto out;
1338
1339        /*
1340         * In this case we've just received a packet from a source
1341         * outside ourselves pretending to come from us. We don't
1342         * allow it any further to prevent routing loops, spoofing and
1343         * other nasties. Loopback packets already have the dst attached
1344         * so this only affects packets which have originated elsewhere.
1345         */
1346        err  = -ENOTUNIQ;
1347        if (dn_dev_islocal(in_dev, cb->src))
1348                goto out;
1349
1350        err = dn_fib_lookup(&fld, &res);
1351        if (err) {
1352                if (err != -ESRCH)
1353                        goto out;
1354                /*
1355                 * Is the destination us ?
1356                 */
1357                if (!dn_dev_islocal(in_dev, cb->dst))
1358                        goto e_inval;
1359
1360                res.type = RTN_LOCAL;
1361        } else {
1362                __le16 src_map = fld.saddr;
1363                free_res = 1;
1364
1365                out_dev = DN_FIB_RES_DEV(res);
1366                if (out_dev == NULL) {
1367                        net_crit_ratelimited("Bug in dn_route_input_slow() No output device\n");
1368                        goto e_inval;
1369                }
1370                dev_hold(out_dev);
1371
1372                if (res.r)
1373                        src_map = fld.saddr; /* no NAT support for now */
1374
1375                gateway = DN_FIB_RES_GW(res);
1376                if (res.type == RTN_NAT) {
1377                        fld.daddr = dn_fib_rules_map_destination(fld.daddr, &res);
1378                        dn_fib_res_put(&res);
1379                        free_res = 0;
1380                        if (dn_fib_lookup(&fld, &res))
1381                                goto e_inval;
1382                        free_res = 1;
1383                        if (res.type != RTN_UNICAST)
1384                                goto e_inval;
1385                        flags |= RTCF_DNAT;
1386                        gateway = fld.daddr;
1387                }
1388                fld.saddr = src_map;
1389        }
1390
1391        switch (res.type) {
1392        case RTN_UNICAST:
1393                /*
1394                 * Forwarding check here, we only check for forwarding
1395                 * being turned off, if you want to only forward intra
1396                 * area, its up to you to set the routing tables up
1397                 * correctly.
1398                 */
1399                if (dn_db->parms.forwarding == 0)
1400                        goto e_inval;
1401
1402                if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1403                        dn_fib_select_multipath(&fld, &res);
1404
1405                /*
1406                 * Check for out_dev == in_dev. We use the RTCF_DOREDIRECT
1407                 * flag as a hint to set the intra-ethernet bit when
1408                 * forwarding. If we've got NAT in operation, we don't do
1409                 * this optimisation.
1410                 */
1411                if (out_dev == in_dev && !(flags & RTCF_NAT))
1412                        flags |= RTCF_DOREDIRECT;
1413
1414                local_src = DN_FIB_RES_PREFSRC(res);
1415                break;
1416        case RTN_BLACKHOLE:
1417        case RTN_UNREACHABLE:
1418                break;
1419        case RTN_LOCAL:
1420                flags |= RTCF_LOCAL;
1421                fld.saddr = cb->dst;
1422                fld.daddr = cb->src;
1423
1424                /* Routing tables gave us a gateway */
1425                if (gateway)
1426                        goto make_route;
1427
1428                /* Packet was intra-ethernet, so we know its on-link */
1429                if (cb->rt_flags & DN_RT_F_IE) {
1430                        gateway = cb->src;
1431                        goto make_route;
1432                }
1433
1434                /* Use the default router if there is one */
1435                neigh = neigh_clone(dn_db->router);
1436                if (neigh) {
1437                        gateway = ((struct dn_neigh *)neigh)->addr;
1438                        goto make_route;
1439                }
1440
1441                /* Close eyes and pray */
1442                gateway = cb->src;
1443                goto make_route;
1444        default:
1445                goto e_inval;
1446        }
1447
1448make_route:
1449        rt = dst_alloc(&dn_dst_ops, out_dev, 1, DST_OBSOLETE_NONE, 0);
1450        if (rt == NULL)
1451                goto e_nobufs;
1452
1453        rt->dn_next = NULL;
1454        memset(&rt->fld, 0, sizeof(rt->fld));
1455        rt->rt_saddr      = fld.saddr;
1456        rt->rt_daddr      = fld.daddr;
1457        rt->rt_gateway    = fld.daddr;
1458        if (gateway)
1459                rt->rt_gateway = gateway;
1460        rt->rt_local_src  = local_src ? local_src : rt->rt_saddr;
1461
1462        rt->rt_dst_map    = fld.daddr;
1463        rt->rt_src_map    = fld.saddr;
1464
1465        rt->fld.saddr        = cb->src;
1466        rt->fld.daddr        = cb->dst;
1467        rt->fld.flowidn_oif  = 0;
1468        rt->fld.flowidn_iif  = in_dev->ifindex;
1469        rt->fld.flowidn_mark = fld.flowidn_mark;
1470
1471        rt->n = neigh;
1472        rt->dst.lastuse = jiffies;
1473        rt->dst.output = dn_rt_bug_out;
1474        switch (res.type) {
1475        case RTN_UNICAST:
1476                rt->dst.input = dn_forward;
1477                break;
1478        case RTN_LOCAL:
1479                rt->dst.output = dn_output;
1480                rt->dst.input = dn_nsp_rx;
1481                rt->dst.dev = in_dev;
1482                flags |= RTCF_LOCAL;
1483                break;
1484        default:
1485        case RTN_UNREACHABLE:
1486        case RTN_BLACKHOLE:
1487                rt->dst.input = dst_discard;
1488        }
1489        rt->rt_flags = flags;
1490
1491        err = dn_rt_set_next_hop(rt, &res);
1492        if (err)
1493                goto e_neighbour;
1494
1495        hash = dn_hash(rt->fld.saddr, rt->fld.daddr);
1496        /* dn_insert_route() increments dst->__refcnt */
1497        dn_insert_route(rt, hash, &rt);
1498        skb_dst_set(skb, &rt->dst);
1499
1500done:
1501        if (neigh)
1502                neigh_release(neigh);
1503        if (free_res)
1504                dn_fib_res_put(&res);
1505        dev_put(in_dev);
1506        if (out_dev)
1507                dev_put(out_dev);
1508out:
1509        return err;
1510
1511e_inval:
1512        err = -EINVAL;
1513        goto done;
1514
1515e_nobufs:
1516        err = -ENOBUFS;
1517        goto done;
1518
1519e_neighbour:
1520        dst_release_immediate(&rt->dst);
1521        goto done;
1522}
1523
1524static int dn_route_input(struct sk_buff *skb)
1525{
1526        struct dn_route *rt;
1527        struct dn_skb_cb *cb = DN_SKB_CB(skb);
1528        unsigned int hash = dn_hash(cb->src, cb->dst);
1529
1530        if (skb_dst(skb))
1531                return 0;
1532
1533        rcu_read_lock();
1534        for (rt = rcu_dereference(dn_rt_hash_table[hash].chain); rt != NULL;
1535            rt = rcu_dereference(rt->dn_next)) {
1536                if ((rt->fld.saddr == cb->src) &&
1537                    (rt->fld.daddr == cb->dst) &&
1538                    (rt->fld.flowidn_oif == 0) &&
1539                    (rt->fld.flowidn_mark == skb->mark) &&
1540                    (rt->fld.flowidn_iif == cb->iif)) {
1541                        dst_hold_and_use(&rt->dst, jiffies);
1542                        rcu_read_unlock();
1543                        skb_dst_set(skb, (struct dst_entry *)rt);
1544                        return 0;
1545                }
1546        }
1547        rcu_read_unlock();
1548
1549        return dn_route_input_slow(skb);
1550}
1551
1552static int dn_rt_fill_info(struct sk_buff *skb, u32 portid, u32 seq,
1553                           int event, int nowait, unsigned int flags)
1554{
1555        struct dn_route *rt = (struct dn_route *)skb_dst(skb);
1556        struct rtmsg *r;
1557        struct nlmsghdr *nlh;
1558        long expires;
1559
1560        nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
1561        if (!nlh)
1562                return -EMSGSIZE;
1563
1564        r = nlmsg_data(nlh);
1565        r->rtm_family = AF_DECnet;
1566        r->rtm_dst_len = 16;
1567        r->rtm_src_len = 0;
1568        r->rtm_tos = 0;
1569        r->rtm_table = RT_TABLE_MAIN;
1570        r->rtm_type = rt->rt_type;
1571        r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
1572        r->rtm_scope = RT_SCOPE_UNIVERSE;
1573        r->rtm_protocol = RTPROT_UNSPEC;
1574
1575        if (rt->rt_flags & RTCF_NOTIFY)
1576                r->rtm_flags |= RTM_F_NOTIFY;
1577
1578        if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN) < 0 ||
1579            nla_put_le16(skb, RTA_DST, rt->rt_daddr) < 0)
1580                goto errout;
1581
1582        if (rt->fld.saddr) {
1583                r->rtm_src_len = 16;
1584                if (nla_put_le16(skb, RTA_SRC, rt->fld.saddr) < 0)
1585                        goto errout;
1586        }
1587        if (rt->dst.dev &&
1588            nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex) < 0)
1589                goto errout;
1590
1591        /*
1592         * Note to self - change this if input routes reverse direction when
1593         * they deal only with inputs and not with replies like they do
1594         * currently.
1595         */
1596        if (nla_put_le16(skb, RTA_PREFSRC, rt->rt_local_src) < 0)
1597                goto errout;
1598
1599        if (rt->rt_daddr != rt->rt_gateway &&
1600            nla_put_le16(skb, RTA_GATEWAY, rt->rt_gateway) < 0)
1601                goto errout;
1602
1603        if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
1604                goto errout;
1605
1606        expires = rt->dst.expires ? rt->dst.expires - jiffies : 0;
1607        if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires,
1608                               rt->dst.error) < 0)
1609                goto errout;
1610
1611        if (dn_is_input_route(rt) &&
1612            nla_put_u32(skb, RTA_IIF, rt->fld.flowidn_iif) < 0)
1613                goto errout;
1614
1615        nlmsg_end(skb, nlh);
1616        return 0;
1617
1618errout:
1619        nlmsg_cancel(skb, nlh);
1620        return -EMSGSIZE;
1621}
1622
1623const struct nla_policy rtm_dn_policy[RTA_MAX + 1] = {
1624        [RTA_DST]               = { .type = NLA_U16 },
1625        [RTA_SRC]               = { .type = NLA_U16 },
1626        [RTA_IIF]               = { .type = NLA_U32 },
1627        [RTA_OIF]               = { .type = NLA_U32 },
1628        [RTA_GATEWAY]           = { .type = NLA_U16 },
1629        [RTA_PRIORITY]          = { .type = NLA_U32 },
1630        [RTA_PREFSRC]           = { .type = NLA_U16 },
1631        [RTA_METRICS]           = { .type = NLA_NESTED },
1632        [RTA_MULTIPATH]         = { .type = NLA_NESTED },
1633        [RTA_TABLE]             = { .type = NLA_U32 },
1634        [RTA_MARK]              = { .type = NLA_U32 },
1635};
1636
1637/*
1638 * This is called by both endnodes and routers now.
1639 */
1640static int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
1641                             struct netlink_ext_ack *extack)
1642{
1643        struct net *net = sock_net(in_skb->sk);
1644        struct rtmsg *rtm = nlmsg_data(nlh);
1645        struct dn_route *rt = NULL;
1646        struct dn_skb_cb *cb;
1647        int err;
1648        struct sk_buff *skb;
1649        struct flowidn fld;
1650        struct nlattr *tb[RTA_MAX+1];
1651
1652        if (!net_eq(net, &init_net))
1653                return -EINVAL;
1654
1655        err = nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
1656                                     rtm_dn_policy, extack);
1657        if (err < 0)
1658                return err;
1659
1660        memset(&fld, 0, sizeof(fld));
1661        fld.flowidn_proto = DNPROTO_NSP;
1662
1663        skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1664        if (skb == NULL)
1665                return -ENOBUFS;
1666        skb_reset_mac_header(skb);
1667        cb = DN_SKB_CB(skb);
1668
1669        if (tb[RTA_SRC])
1670                fld.saddr = nla_get_le16(tb[RTA_SRC]);
1671
1672        if (tb[RTA_DST])
1673                fld.daddr = nla_get_le16(tb[RTA_DST]);
1674
1675        if (tb[RTA_IIF])
1676                fld.flowidn_iif = nla_get_u32(tb[RTA_IIF]);
1677
1678        if (fld.flowidn_iif) {
1679                struct net_device *dev;
1680                dev = __dev_get_by_index(&init_net, fld.flowidn_iif);
1681                if (!dev || !dev->dn_ptr) {
1682                        kfree_skb(skb);
1683                        return -ENODEV;
1684                }
1685                skb->protocol = htons(ETH_P_DNA_RT);
1686                skb->dev = dev;
1687                cb->src = fld.saddr;
1688                cb->dst = fld.daddr;
1689                local_bh_disable();
1690                err = dn_route_input(skb);
1691                local_bh_enable();
1692                memset(cb, 0, sizeof(struct dn_skb_cb));
1693                rt = (struct dn_route *)skb_dst(skb);
1694                if (!err && -rt->dst.error)
1695                        err = rt->dst.error;
1696        } else {
1697                if (tb[RTA_OIF])
1698                        fld.flowidn_oif = nla_get_u32(tb[RTA_OIF]);
1699
1700                err = dn_route_output_key((struct dst_entry **)&rt, &fld, 0);
1701        }
1702
1703        skb->dev = NULL;
1704        if (err)
1705                goto out_free;
1706        skb_dst_set(skb, &rt->dst);
1707        if (rtm->rtm_flags & RTM_F_NOTIFY)
1708                rt->rt_flags |= RTCF_NOTIFY;
1709
1710        err = dn_rt_fill_info(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, RTM_NEWROUTE, 0, 0);
1711        if (err < 0) {
1712                err = -EMSGSIZE;
1713                goto out_free;
1714        }
1715
1716        return rtnl_unicast(skb, &init_net, NETLINK_CB(in_skb).portid);
1717
1718out_free:
1719        kfree_skb(skb);
1720        return err;
1721}
1722
1723/*
1724 * For routers, this is called from dn_fib_dump, but for endnodes its
1725 * called directly from the rtnetlink dispatch table.
1726 */
1727int dn_cache_dump(struct sk_buff *skb, struct netlink_callback *cb)
1728{
1729        struct net *net = sock_net(skb->sk);
1730        struct dn_route *rt;
1731        int h, s_h;
1732        int idx, s_idx;
1733        struct rtmsg *rtm;
1734
1735        if (!net_eq(net, &init_net))
1736                return 0;
1737
1738        if (nlmsg_len(cb->nlh) < sizeof(struct rtmsg))
1739                return -EINVAL;
1740
1741        rtm = nlmsg_data(cb->nlh);
1742        if (!(rtm->rtm_flags & RTM_F_CLONED))
1743                return 0;
1744
1745        s_h = cb->args[0];
1746        s_idx = idx = cb->args[1];
1747        for (h = 0; h <= dn_rt_hash_mask; h++) {
1748                if (h < s_h)
1749                        continue;
1750                if (h > s_h)
1751                        s_idx = 0;
1752                rcu_read_lock_bh();
1753                for (rt = rcu_dereference_bh(dn_rt_hash_table[h].chain), idx = 0;
1754                        rt;
1755                        rt = rcu_dereference_bh(rt->dn_next), idx++) {
1756                        if (idx < s_idx)
1757                                continue;
1758                        skb_dst_set(skb, dst_clone(&rt->dst));
1759                        if (dn_rt_fill_info(skb, NETLINK_CB(cb->skb).portid,
1760                                        cb->nlh->nlmsg_seq, RTM_NEWROUTE,
1761                                        1, NLM_F_MULTI) < 0) {
1762                                skb_dst_drop(skb);
1763                                rcu_read_unlock_bh();
1764                                goto done;
1765                        }
1766                        skb_dst_drop(skb);
1767                }
1768                rcu_read_unlock_bh();
1769        }
1770
1771done:
1772        cb->args[0] = h;
1773        cb->args[1] = idx;
1774        return skb->len;
1775}
1776
1777#ifdef CONFIG_PROC_FS
1778struct dn_rt_cache_iter_state {
1779        int bucket;
1780};
1781
1782static struct dn_route *dn_rt_cache_get_first(struct seq_file *seq)
1783{
1784        struct dn_route *rt = NULL;
1785        struct dn_rt_cache_iter_state *s = seq->private;
1786
1787        for (s->bucket = dn_rt_hash_mask; s->bucket >= 0; --s->bucket) {
1788                rcu_read_lock_bh();
1789                rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1790                if (rt)
1791                        break;
1792                rcu_read_unlock_bh();
1793        }
1794        return rt;
1795}
1796
1797static struct dn_route *dn_rt_cache_get_next(struct seq_file *seq, struct dn_route *rt)
1798{
1799        struct dn_rt_cache_iter_state *s = seq->private;
1800
1801        rt = rcu_dereference_bh(rt->dn_next);
1802        while (!rt) {
1803                rcu_read_unlock_bh();
1804                if (--s->bucket < 0)
1805                        break;
1806                rcu_read_lock_bh();
1807                rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1808        }
1809        return rt;
1810}
1811
1812static void *dn_rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
1813{
1814        struct dn_route *rt = dn_rt_cache_get_first(seq);
1815
1816        if (rt) {
1817                while (*pos && (rt = dn_rt_cache_get_next(seq, rt)))
1818                        --*pos;
1819        }
1820        return *pos ? NULL : rt;
1821}
1822
1823static void *dn_rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1824{
1825        struct dn_route *rt = dn_rt_cache_get_next(seq, v);
1826        ++*pos;
1827        return rt;
1828}
1829
1830static void dn_rt_cache_seq_stop(struct seq_file *seq, void *v)
1831{
1832        if (v)
1833                rcu_read_unlock_bh();
1834}
1835
1836static int dn_rt_cache_seq_show(struct seq_file *seq, void *v)
1837{
1838        struct dn_route *rt = v;
1839        char buf1[DN_ASCBUF_LEN], buf2[DN_ASCBUF_LEN];
1840
1841        seq_printf(seq, "%-8s %-7s %-7s %04d %04d %04d\n",
1842                   rt->dst.dev ? rt->dst.dev->name : "*",
1843                   dn_addr2asc(le16_to_cpu(rt->rt_daddr), buf1),
1844                   dn_addr2asc(le16_to_cpu(rt->rt_saddr), buf2),
1845                   atomic_read(&rt->dst.__refcnt),
1846                   rt->dst.__use, 0);
1847        return 0;
1848}
1849
1850static const struct seq_operations dn_rt_cache_seq_ops = {
1851        .start  = dn_rt_cache_seq_start,
1852        .next   = dn_rt_cache_seq_next,
1853        .stop   = dn_rt_cache_seq_stop,
1854        .show   = dn_rt_cache_seq_show,
1855};
1856#endif /* CONFIG_PROC_FS */
1857
1858void __init dn_route_init(void)
1859{
1860        int i, goal, order;
1861
1862        dn_dst_ops.kmem_cachep =
1863                kmem_cache_create("dn_dst_cache", sizeof(struct dn_route), 0,
1864                                  SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
1865        dst_entries_init(&dn_dst_ops);
1866        timer_setup(&dn_route_timer, dn_dst_check_expire, 0);
1867        dn_route_timer.expires = jiffies + decnet_dst_gc_interval * HZ;
1868        add_timer(&dn_route_timer);
1869
1870        goal = totalram_pages() >> (26 - PAGE_SHIFT);
1871
1872        for (order = 0; (1UL << order) < goal; order++)
1873                /* NOTHING */;
1874
1875        /*
1876         * Only want 1024 entries max, since the table is very, very unlikely
1877         * to be larger than that.
1878         */
1879        while (order && ((((1UL << order) * PAGE_SIZE) /
1880                                sizeof(struct dn_rt_hash_bucket)) >= 2048))
1881                order--;
1882
1883        do {
1884                dn_rt_hash_mask = (1UL << order) * PAGE_SIZE /
1885                        sizeof(struct dn_rt_hash_bucket);
1886                while (dn_rt_hash_mask & (dn_rt_hash_mask - 1))
1887                        dn_rt_hash_mask--;
1888                dn_rt_hash_table = (struct dn_rt_hash_bucket *)
1889                        __get_free_pages(GFP_ATOMIC, order);
1890        } while (dn_rt_hash_table == NULL && --order > 0);
1891
1892        if (!dn_rt_hash_table)
1893                panic("Failed to allocate DECnet route cache hash table\n");
1894
1895        printk(KERN_INFO
1896                "DECnet: Routing cache hash table of %u buckets, %ldKbytes\n",
1897                dn_rt_hash_mask,
1898                (long)(dn_rt_hash_mask*sizeof(struct dn_rt_hash_bucket))/1024);
1899
1900        dn_rt_hash_mask--;
1901        for (i = 0; i <= dn_rt_hash_mask; i++) {
1902                spin_lock_init(&dn_rt_hash_table[i].lock);
1903                dn_rt_hash_table[i].chain = NULL;
1904        }
1905
1906        dn_dst_ops.gc_thresh = (dn_rt_hash_mask + 1);
1907
1908        proc_create_seq_private("decnet_cache", 0444, init_net.proc_net,
1909                        &dn_rt_cache_seq_ops,
1910                        sizeof(struct dn_rt_cache_iter_state), NULL);
1911
1912#ifdef CONFIG_DECNET_ROUTER
1913        rtnl_register_module(THIS_MODULE, PF_DECnet, RTM_GETROUTE,
1914                             dn_cache_getroute, dn_fib_dump, 0);
1915#else
1916        rtnl_register_module(THIS_MODULE, PF_DECnet, RTM_GETROUTE,
1917                             dn_cache_getroute, dn_cache_dump, 0);
1918#endif
1919}
1920
1921void __exit dn_route_cleanup(void)
1922{
1923        del_timer(&dn_route_timer);
1924        dn_run_flush(NULL);
1925
1926        remove_proc_entry("decnet_cache", init_net.proc_net);
1927        dst_entries_destroy(&dn_dst_ops);
1928}
1929