linux/net/decnet/dn_route.c
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   1/*
   2 * DECnet       An implementation of the DECnet protocol suite for the LINUX
   3 *              operating system.  DECnet is implemented using the  BSD Socket
   4 *              interface as the means of communication with the user level.
   5 *
   6 *              DECnet Routing Functions (Endnode and Router)
   7 *
   8 * Authors:     Steve Whitehouse <SteveW@ACM.org>
   9 *              Eduardo Marcelo Serrat <emserrat@geocities.com>
  10 *
  11 * Changes:
  12 *              Steve Whitehouse : Fixes to allow "intra-ethernet" and
  13 *                                 "return-to-sender" bits on outgoing
  14 *                                 packets.
  15 *              Steve Whitehouse : Timeouts for cached routes.
  16 *              Steve Whitehouse : Use dst cache for input routes too.
  17 *              Steve Whitehouse : Fixed error values in dn_send_skb.
  18 *              Steve Whitehouse : Rework routing functions to better fit
  19 *                                 DECnet routing design
  20 *              Alexey Kuznetsov : New SMP locking
  21 *              Steve Whitehouse : More SMP locking changes & dn_cache_dump()
  22 *              Steve Whitehouse : Prerouting NF hook, now really is prerouting.
  23 *                                 Fixed possible skb leak in rtnetlink funcs.
  24 *              Steve Whitehouse : Dave Miller's dynamic hash table sizing and
  25 *                                 Alexey Kuznetsov's finer grained locking
  26 *                                 from ipv4/route.c.
  27 *              Steve Whitehouse : Routing is now starting to look like a
  28 *                                 sensible set of code now, mainly due to
  29 *                                 my copying the IPv4 routing code. The
  30 *                                 hooks here are modified and will continue
  31 *                                 to evolve for a while.
  32 *              Steve Whitehouse : Real SMP at last :-) Also new netfilter
  33 *                                 stuff. Look out raw sockets your days
  34 *                                 are numbered!
  35 *              Steve Whitehouse : Added return-to-sender functions. Added
  36 *                                 backlog congestion level return codes.
  37 *              Steve Whitehouse : Fixed bug where routes were set up with
  38 *                                 no ref count on net devices.
  39 *              Steve Whitehouse : RCU for the route cache
  40 *              Steve Whitehouse : Preparations for the flow cache
  41 *              Steve Whitehouse : Prepare for nonlinear skbs
  42 */
  43
  44/******************************************************************************
  45    (c) 1995-1998 E.M. Serrat           emserrat@geocities.com
  46
  47    This program is free software; you can redistribute it and/or modify
  48    it under the terms of the GNU General Public License as published by
  49    the Free Software Foundation; either version 2 of the License, or
  50    any later version.
  51
  52    This program is distributed in the hope that it will be useful,
  53    but WITHOUT ANY WARRANTY; without even the implied warranty of
  54    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  55    GNU General Public License for more details.
  56*******************************************************************************/
  57
  58#include <linux/errno.h>
  59#include <linux/types.h>
  60#include <linux/socket.h>
  61#include <linux/in.h>
  62#include <linux/kernel.h>
  63#include <linux/sockios.h>
  64#include <linux/net.h>
  65#include <linux/netdevice.h>
  66#include <linux/inet.h>
  67#include <linux/route.h>
  68#include <linux/in_route.h>
  69#include <linux/slab.h>
  70#include <net/sock.h>
  71#include <linux/mm.h>
  72#include <linux/proc_fs.h>
  73#include <linux/seq_file.h>
  74#include <linux/init.h>
  75#include <linux/rtnetlink.h>
  76#include <linux/string.h>
  77#include <linux/netfilter_decnet.h>
  78#include <linux/rcupdate.h>
  79#include <linux/times.h>
  80#include <linux/export.h>
  81#include <asm/errno.h>
  82#include <net/net_namespace.h>
  83#include <net/netlink.h>
  84#include <net/neighbour.h>
  85#include <net/dst.h>
  86#include <net/flow.h>
  87#include <net/fib_rules.h>
  88#include <net/dn.h>
  89#include <net/dn_dev.h>
  90#include <net/dn_nsp.h>
  91#include <net/dn_route.h>
  92#include <net/dn_neigh.h>
  93#include <net/dn_fib.h>
  94
  95struct dn_rt_hash_bucket
  96{
  97        struct dn_route __rcu *chain;
  98        spinlock_t lock;
  99};
 100
 101extern struct neigh_table dn_neigh_table;
 102
 103
 104static unsigned char dn_hiord_addr[6] = {0xAA,0x00,0x04,0x00,0x00,0x00};
 105
 106static const int dn_rt_min_delay = 2 * HZ;
 107static const int dn_rt_max_delay = 10 * HZ;
 108static const int dn_rt_mtu_expires = 10 * 60 * HZ;
 109
 110static unsigned long dn_rt_deadline;
 111
 112static int dn_dst_gc(struct dst_ops *ops);
 113static struct dst_entry *dn_dst_check(struct dst_entry *, __u32);
 114static unsigned int dn_dst_default_advmss(const struct dst_entry *dst);
 115static unsigned int dn_dst_mtu(const struct dst_entry *dst);
 116static void dn_dst_destroy(struct dst_entry *);
 117static void dn_dst_ifdown(struct dst_entry *, struct net_device *dev, int how);
 118static struct dst_entry *dn_dst_negative_advice(struct dst_entry *);
 119static void dn_dst_link_failure(struct sk_buff *);
 120static void dn_dst_update_pmtu(struct dst_entry *dst, struct sock *sk,
 121                               struct sk_buff *skb , u32 mtu);
 122static void dn_dst_redirect(struct dst_entry *dst, struct sock *sk,
 123                            struct sk_buff *skb);
 124static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst,
 125                                             struct sk_buff *skb,
 126                                             const void *daddr);
 127static int dn_route_input(struct sk_buff *);
 128static void dn_run_flush(unsigned long dummy);
 129
 130static struct dn_rt_hash_bucket *dn_rt_hash_table;
 131static unsigned int dn_rt_hash_mask;
 132
 133static struct timer_list dn_route_timer;
 134static DEFINE_TIMER(dn_rt_flush_timer, dn_run_flush, 0, 0);
 135int decnet_dst_gc_interval = 2;
 136
 137static struct dst_ops dn_dst_ops = {
 138        .family =               PF_DECnet,
 139        .gc_thresh =            128,
 140        .gc =                   dn_dst_gc,
 141        .check =                dn_dst_check,
 142        .default_advmss =       dn_dst_default_advmss,
 143        .mtu =                  dn_dst_mtu,
 144        .cow_metrics =          dst_cow_metrics_generic,
 145        .destroy =              dn_dst_destroy,
 146        .ifdown =               dn_dst_ifdown,
 147        .negative_advice =      dn_dst_negative_advice,
 148        .link_failure =         dn_dst_link_failure,
 149        .update_pmtu =          dn_dst_update_pmtu,
 150        .redirect =             dn_dst_redirect,
 151        .neigh_lookup =         dn_dst_neigh_lookup,
 152};
 153
 154static void dn_dst_destroy(struct dst_entry *dst)
 155{
 156        struct dn_route *rt = (struct dn_route *) dst;
 157
 158        if (rt->n)
 159                neigh_release(rt->n);
 160        dst_destroy_metrics_generic(dst);
 161}
 162
 163static void dn_dst_ifdown(struct dst_entry *dst, struct net_device *dev, int how)
 164{
 165        if (how) {
 166                struct dn_route *rt = (struct dn_route *) dst;
 167                struct neighbour *n = rt->n;
 168
 169                if (n && n->dev == dev) {
 170                        n->dev = dev_net(dev)->loopback_dev;
 171                        dev_hold(n->dev);
 172                        dev_put(dev);
 173                }
 174        }
 175}
 176
 177static __inline__ unsigned int dn_hash(__le16 src, __le16 dst)
 178{
 179        __u16 tmp = (__u16 __force)(src ^ dst);
 180        tmp ^= (tmp >> 3);
 181        tmp ^= (tmp >> 5);
 182        tmp ^= (tmp >> 10);
 183        return dn_rt_hash_mask & (unsigned int)tmp;
 184}
 185
 186static inline void dnrt_free(struct dn_route *rt)
 187{
 188        call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
 189}
 190
 191static inline void dnrt_drop(struct dn_route *rt)
 192{
 193        dst_release(&rt->dst);
 194        call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
 195}
 196
 197static void dn_dst_check_expire(unsigned long dummy)
 198{
 199        int i;
 200        struct dn_route *rt;
 201        struct dn_route __rcu **rtp;
 202        unsigned long now = jiffies;
 203        unsigned long expire = 120 * HZ;
 204
 205        for (i = 0; i <= dn_rt_hash_mask; i++) {
 206                rtp = &dn_rt_hash_table[i].chain;
 207
 208                spin_lock(&dn_rt_hash_table[i].lock);
 209                while ((rt = rcu_dereference_protected(*rtp,
 210                                                lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) {
 211                        if (atomic_read(&rt->dst.__refcnt) ||
 212                                        (now - rt->dst.lastuse) < expire) {
 213                                rtp = &rt->dst.dn_next;
 214                                continue;
 215                        }
 216                        *rtp = rt->dst.dn_next;
 217                        rt->dst.dn_next = NULL;
 218                        dnrt_free(rt);
 219                }
 220                spin_unlock(&dn_rt_hash_table[i].lock);
 221
 222                if ((jiffies - now) > 0)
 223                        break;
 224        }
 225
 226        mod_timer(&dn_route_timer, now + decnet_dst_gc_interval * HZ);
 227}
 228
 229static int dn_dst_gc(struct dst_ops *ops)
 230{
 231        struct dn_route *rt;
 232        struct dn_route __rcu **rtp;
 233        int i;
 234        unsigned long now = jiffies;
 235        unsigned long expire = 10 * HZ;
 236
 237        for (i = 0; i <= dn_rt_hash_mask; i++) {
 238
 239                spin_lock_bh(&dn_rt_hash_table[i].lock);
 240                rtp = &dn_rt_hash_table[i].chain;
 241
 242                while ((rt = rcu_dereference_protected(*rtp,
 243                                                lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) {
 244                        if (atomic_read(&rt->dst.__refcnt) ||
 245                                        (now - rt->dst.lastuse) < expire) {
 246                                rtp = &rt->dst.dn_next;
 247                                continue;
 248                        }
 249                        *rtp = rt->dst.dn_next;
 250                        rt->dst.dn_next = NULL;
 251                        dnrt_drop(rt);
 252                        break;
 253                }
 254                spin_unlock_bh(&dn_rt_hash_table[i].lock);
 255        }
 256
 257        return 0;
 258}
 259
 260/*
 261 * The decnet standards don't impose a particular minimum mtu, what they
 262 * do insist on is that the routing layer accepts a datagram of at least
 263 * 230 bytes long. Here we have to subtract the routing header length from
 264 * 230 to get the minimum acceptable mtu. If there is no neighbour, then we
 265 * assume the worst and use a long header size.
 266 *
 267 * We update both the mtu and the advertised mss (i.e. the segment size we
 268 * advertise to the other end).
 269 */
 270static void dn_dst_update_pmtu(struct dst_entry *dst, struct sock *sk,
 271                               struct sk_buff *skb, u32 mtu)
 272{
 273        struct dn_route *rt = (struct dn_route *) dst;
 274        struct neighbour *n = rt->n;
 275        u32 min_mtu = 230;
 276        struct dn_dev *dn;
 277
 278        dn = n ? rcu_dereference_raw(n->dev->dn_ptr) : NULL;
 279
 280        if (dn && dn->use_long == 0)
 281                min_mtu -= 6;
 282        else
 283                min_mtu -= 21;
 284
 285        if (dst_metric(dst, RTAX_MTU) > mtu && mtu >= min_mtu) {
 286                if (!(dst_metric_locked(dst, RTAX_MTU))) {
 287                        dst_metric_set(dst, RTAX_MTU, mtu);
 288                        dst_set_expires(dst, dn_rt_mtu_expires);
 289                }
 290                if (!(dst_metric_locked(dst, RTAX_ADVMSS))) {
 291                        u32 mss = mtu - DN_MAX_NSP_DATA_HEADER;
 292                        u32 existing_mss = dst_metric_raw(dst, RTAX_ADVMSS);
 293                        if (!existing_mss || existing_mss > mss)
 294                                dst_metric_set(dst, RTAX_ADVMSS, mss);
 295                }
 296        }
 297}
 298
 299static void dn_dst_redirect(struct dst_entry *dst, struct sock *sk,
 300                            struct sk_buff *skb)
 301{
 302}
 303
 304/*
 305 * When a route has been marked obsolete. (e.g. routing cache flush)
 306 */
 307static struct dst_entry *dn_dst_check(struct dst_entry *dst, __u32 cookie)
 308{
 309        return NULL;
 310}
 311
 312static struct dst_entry *dn_dst_negative_advice(struct dst_entry *dst)
 313{
 314        dst_release(dst);
 315        return NULL;
 316}
 317
 318static void dn_dst_link_failure(struct sk_buff *skb)
 319{
 320}
 321
 322static inline int compare_keys(struct flowidn *fl1, struct flowidn *fl2)
 323{
 324        return ((fl1->daddr ^ fl2->daddr) |
 325                (fl1->saddr ^ fl2->saddr) |
 326                (fl1->flowidn_mark ^ fl2->flowidn_mark) |
 327                (fl1->flowidn_scope ^ fl2->flowidn_scope) |
 328                (fl1->flowidn_oif ^ fl2->flowidn_oif) |
 329                (fl1->flowidn_iif ^ fl2->flowidn_iif)) == 0;
 330}
 331
 332static int dn_insert_route(struct dn_route *rt, unsigned int hash, struct dn_route **rp)
 333{
 334        struct dn_route *rth;
 335        struct dn_route __rcu **rthp;
 336        unsigned long now = jiffies;
 337
 338        rthp = &dn_rt_hash_table[hash].chain;
 339
 340        spin_lock_bh(&dn_rt_hash_table[hash].lock);
 341        while ((rth = rcu_dereference_protected(*rthp,
 342                                                lockdep_is_held(&dn_rt_hash_table[hash].lock))) != NULL) {
 343                if (compare_keys(&rth->fld, &rt->fld)) {
 344                        /* Put it first */
 345                        *rthp = rth->dst.dn_next;
 346                        rcu_assign_pointer(rth->dst.dn_next,
 347                                           dn_rt_hash_table[hash].chain);
 348                        rcu_assign_pointer(dn_rt_hash_table[hash].chain, rth);
 349
 350                        dst_use(&rth->dst, now);
 351                        spin_unlock_bh(&dn_rt_hash_table[hash].lock);
 352
 353                        dnrt_drop(rt);
 354                        *rp = rth;
 355                        return 0;
 356                }
 357                rthp = &rth->dst.dn_next;
 358        }
 359
 360        rcu_assign_pointer(rt->dst.dn_next, dn_rt_hash_table[hash].chain);
 361        rcu_assign_pointer(dn_rt_hash_table[hash].chain, rt);
 362
 363        dst_use(&rt->dst, now);
 364        spin_unlock_bh(&dn_rt_hash_table[hash].lock);
 365        *rp = rt;
 366        return 0;
 367}
 368
 369static void dn_run_flush(unsigned long dummy)
 370{
 371        int i;
 372        struct dn_route *rt, *next;
 373
 374        for (i = 0; i < dn_rt_hash_mask; i++) {
 375                spin_lock_bh(&dn_rt_hash_table[i].lock);
 376
 377                if ((rt = xchg((struct dn_route **)&dn_rt_hash_table[i].chain, NULL)) == NULL)
 378                        goto nothing_to_declare;
 379
 380                for(; rt; rt = next) {
 381                        next = rcu_dereference_raw(rt->dst.dn_next);
 382                        RCU_INIT_POINTER(rt->dst.dn_next, NULL);
 383                        dst_free((struct dst_entry *)rt);
 384                }
 385
 386nothing_to_declare:
 387                spin_unlock_bh(&dn_rt_hash_table[i].lock);
 388        }
 389}
 390
 391static DEFINE_SPINLOCK(dn_rt_flush_lock);
 392
 393void dn_rt_cache_flush(int delay)
 394{
 395        unsigned long now = jiffies;
 396        int user_mode = !in_interrupt();
 397
 398        if (delay < 0)
 399                delay = dn_rt_min_delay;
 400
 401        spin_lock_bh(&dn_rt_flush_lock);
 402
 403        if (del_timer(&dn_rt_flush_timer) && delay > 0 && dn_rt_deadline) {
 404                long tmo = (long)(dn_rt_deadline - now);
 405
 406                if (user_mode && tmo < dn_rt_max_delay - dn_rt_min_delay)
 407                        tmo = 0;
 408
 409                if (delay > tmo)
 410                        delay = tmo;
 411        }
 412
 413        if (delay <= 0) {
 414                spin_unlock_bh(&dn_rt_flush_lock);
 415                dn_run_flush(0);
 416                return;
 417        }
 418
 419        if (dn_rt_deadline == 0)
 420                dn_rt_deadline = now + dn_rt_max_delay;
 421
 422        dn_rt_flush_timer.expires = now + delay;
 423        add_timer(&dn_rt_flush_timer);
 424        spin_unlock_bh(&dn_rt_flush_lock);
 425}
 426
 427/**
 428 * dn_return_short - Return a short packet to its sender
 429 * @skb: The packet to return
 430 *
 431 */
 432static int dn_return_short(struct sk_buff *skb)
 433{
 434        struct dn_skb_cb *cb;
 435        unsigned char *ptr;
 436        __le16 *src;
 437        __le16 *dst;
 438
 439        /* Add back headers */
 440        skb_push(skb, skb->data - skb_network_header(skb));
 441
 442        if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
 443                return NET_RX_DROP;
 444
 445        cb = DN_SKB_CB(skb);
 446        /* Skip packet length and point to flags */
 447        ptr = skb->data + 2;
 448        *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
 449
 450        dst = (__le16 *)ptr;
 451        ptr += 2;
 452        src = (__le16 *)ptr;
 453        ptr += 2;
 454        *ptr = 0; /* Zero hop count */
 455
 456        swap(*src, *dst);
 457
 458        skb->pkt_type = PACKET_OUTGOING;
 459        dn_rt_finish_output(skb, NULL, NULL);
 460        return NET_RX_SUCCESS;
 461}
 462
 463/**
 464 * dn_return_long - Return a long packet to its sender
 465 * @skb: The long format packet to return
 466 *
 467 */
 468static int dn_return_long(struct sk_buff *skb)
 469{
 470        struct dn_skb_cb *cb;
 471        unsigned char *ptr;
 472        unsigned char *src_addr, *dst_addr;
 473        unsigned char tmp[ETH_ALEN];
 474
 475        /* Add back all headers */
 476        skb_push(skb, skb->data - skb_network_header(skb));
 477
 478        if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
 479                return NET_RX_DROP;
 480
 481        cb = DN_SKB_CB(skb);
 482        /* Ignore packet length and point to flags */
 483        ptr = skb->data + 2;
 484
 485        /* Skip padding */
 486        if (*ptr & DN_RT_F_PF) {
 487                char padlen = (*ptr & ~DN_RT_F_PF);
 488                ptr += padlen;
 489        }
 490
 491        *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
 492        ptr += 2;
 493        dst_addr = ptr;
 494        ptr += 8;
 495        src_addr = ptr;
 496        ptr += 6;
 497        *ptr = 0; /* Zero hop count */
 498
 499        /* Swap source and destination */
 500        memcpy(tmp, src_addr, ETH_ALEN);
 501        memcpy(src_addr, dst_addr, ETH_ALEN);
 502        memcpy(dst_addr, tmp, ETH_ALEN);
 503
 504        skb->pkt_type = PACKET_OUTGOING;
 505        dn_rt_finish_output(skb, dst_addr, src_addr);
 506        return NET_RX_SUCCESS;
 507}
 508
 509/**
 510 * dn_route_rx_packet - Try and find a route for an incoming packet
 511 * @skb: The packet to find a route for
 512 *
 513 * Returns: result of input function if route is found, error code otherwise
 514 */
 515static int dn_route_rx_packet(struct net *net, struct sock *sk, struct sk_buff *skb)
 516{
 517        struct dn_skb_cb *cb;
 518        int err;
 519
 520        if ((err = dn_route_input(skb)) == 0)
 521                return dst_input(skb);
 522
 523        cb = DN_SKB_CB(skb);
 524        if (decnet_debug_level & 4) {
 525                char *devname = skb->dev ? skb->dev->name : "???";
 526
 527                printk(KERN_DEBUG
 528                        "DECnet: dn_route_rx_packet: rt_flags=0x%02x dev=%s len=%d src=0x%04hx dst=0x%04hx err=%d type=%d\n",
 529                        (int)cb->rt_flags, devname, skb->len,
 530                        le16_to_cpu(cb->src), le16_to_cpu(cb->dst),
 531                        err, skb->pkt_type);
 532        }
 533
 534        if ((skb->pkt_type == PACKET_HOST) && (cb->rt_flags & DN_RT_F_RQR)) {
 535                switch (cb->rt_flags & DN_RT_PKT_MSK) {
 536                case DN_RT_PKT_SHORT:
 537                        return dn_return_short(skb);
 538                case DN_RT_PKT_LONG:
 539                        return dn_return_long(skb);
 540                }
 541        }
 542
 543        kfree_skb(skb);
 544        return NET_RX_DROP;
 545}
 546
 547static int dn_route_rx_long(struct sk_buff *skb)
 548{
 549        struct dn_skb_cb *cb = DN_SKB_CB(skb);
 550        unsigned char *ptr = skb->data;
 551
 552        if (!pskb_may_pull(skb, 21)) /* 20 for long header, 1 for shortest nsp */
 553                goto drop_it;
 554
 555        skb_pull(skb, 20);
 556        skb_reset_transport_header(skb);
 557
 558        /* Destination info */
 559        ptr += 2;
 560        cb->dst = dn_eth2dn(ptr);
 561        if (memcmp(ptr, dn_hiord_addr, 4) != 0)
 562                goto drop_it;
 563        ptr += 6;
 564
 565
 566        /* Source info */
 567        ptr += 2;
 568        cb->src = dn_eth2dn(ptr);
 569        if (memcmp(ptr, dn_hiord_addr, 4) != 0)
 570                goto drop_it;
 571        ptr += 6;
 572        /* Other junk */
 573        ptr++;
 574        cb->hops = *ptr++; /* Visit Count */
 575
 576        return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING,
 577                       &init_net, NULL, skb, skb->dev, NULL,
 578                       dn_route_rx_packet);
 579
 580drop_it:
 581        kfree_skb(skb);
 582        return NET_RX_DROP;
 583}
 584
 585
 586
 587static int dn_route_rx_short(struct sk_buff *skb)
 588{
 589        struct dn_skb_cb *cb = DN_SKB_CB(skb);
 590        unsigned char *ptr = skb->data;
 591
 592        if (!pskb_may_pull(skb, 6)) /* 5 for short header + 1 for shortest nsp */
 593                goto drop_it;
 594
 595        skb_pull(skb, 5);
 596        skb_reset_transport_header(skb);
 597
 598        cb->dst = *(__le16 *)ptr;
 599        ptr += 2;
 600        cb->src = *(__le16 *)ptr;
 601        ptr += 2;
 602        cb->hops = *ptr & 0x3f;
 603
 604        return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING,
 605                       &init_net, NULL, skb, skb->dev, NULL,
 606                       dn_route_rx_packet);
 607
 608drop_it:
 609        kfree_skb(skb);
 610        return NET_RX_DROP;
 611}
 612
 613static int dn_route_discard(struct net *net, struct sock *sk, struct sk_buff *skb)
 614{
 615        /*
 616         * I know we drop the packet here, but thats considered success in
 617         * this case
 618         */
 619        kfree_skb(skb);
 620        return NET_RX_SUCCESS;
 621}
 622
 623static int dn_route_ptp_hello(struct net *net, struct sock *sk, struct sk_buff *skb)
 624{
 625        dn_dev_hello(skb);
 626        dn_neigh_pointopoint_hello(skb);
 627        return NET_RX_SUCCESS;
 628}
 629
 630int dn_route_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
 631{
 632        struct dn_skb_cb *cb;
 633        unsigned char flags = 0;
 634        __u16 len = le16_to_cpu(*(__le16 *)skb->data);
 635        struct dn_dev *dn = rcu_dereference(dev->dn_ptr);
 636        unsigned char padlen = 0;
 637
 638        if (!net_eq(dev_net(dev), &init_net))
 639                goto dump_it;
 640
 641        if (dn == NULL)
 642                goto dump_it;
 643
 644        if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
 645                goto out;
 646
 647        if (!pskb_may_pull(skb, 3))
 648                goto dump_it;
 649
 650        skb_pull(skb, 2);
 651
 652        if (len > skb->len)
 653                goto dump_it;
 654
 655        skb_trim(skb, len);
 656
 657        flags = *skb->data;
 658
 659        cb = DN_SKB_CB(skb);
 660        cb->stamp = jiffies;
 661        cb->iif = dev->ifindex;
 662
 663        /*
 664         * If we have padding, remove it.
 665         */
 666        if (flags & DN_RT_F_PF) {
 667                padlen = flags & ~DN_RT_F_PF;
 668                if (!pskb_may_pull(skb, padlen + 1))
 669                        goto dump_it;
 670                skb_pull(skb, padlen);
 671                flags = *skb->data;
 672        }
 673
 674        skb_reset_network_header(skb);
 675
 676        /*
 677         * Weed out future version DECnet
 678         */
 679        if (flags & DN_RT_F_VER)
 680                goto dump_it;
 681
 682        cb->rt_flags = flags;
 683
 684        if (decnet_debug_level & 1)
 685                printk(KERN_DEBUG
 686                        "dn_route_rcv: got 0x%02x from %s [%d %d %d]\n",
 687                        (int)flags, (dev) ? dev->name : "???", len, skb->len,
 688                        padlen);
 689
 690        if (flags & DN_RT_PKT_CNTL) {
 691                if (unlikely(skb_linearize(skb)))
 692                        goto dump_it;
 693
 694                switch (flags & DN_RT_CNTL_MSK) {
 695                case DN_RT_PKT_INIT:
 696                        dn_dev_init_pkt(skb);
 697                        break;
 698                case DN_RT_PKT_VERI:
 699                        dn_dev_veri_pkt(skb);
 700                        break;
 701                }
 702
 703                if (dn->parms.state != DN_DEV_S_RU)
 704                        goto dump_it;
 705
 706                switch (flags & DN_RT_CNTL_MSK) {
 707                case DN_RT_PKT_HELO:
 708                        return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
 709                                       &init_net, NULL, skb, skb->dev, NULL,
 710                                       dn_route_ptp_hello);
 711
 712                case DN_RT_PKT_L1RT:
 713                case DN_RT_PKT_L2RT:
 714                        return NF_HOOK(NFPROTO_DECNET, NF_DN_ROUTE,
 715                                       &init_net, NULL, skb, skb->dev, NULL,
 716                                       dn_route_discard);
 717                case DN_RT_PKT_ERTH:
 718                        return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
 719                                       &init_net, NULL, skb, skb->dev, NULL,
 720                                       dn_neigh_router_hello);
 721
 722                case DN_RT_PKT_EEDH:
 723                        return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
 724                                       &init_net, NULL, skb, skb->dev, NULL,
 725                                       dn_neigh_endnode_hello);
 726                }
 727        } else {
 728                if (dn->parms.state != DN_DEV_S_RU)
 729                        goto dump_it;
 730
 731                skb_pull(skb, 1); /* Pull flags */
 732
 733                switch (flags & DN_RT_PKT_MSK) {
 734                case DN_RT_PKT_LONG:
 735                        return dn_route_rx_long(skb);
 736                case DN_RT_PKT_SHORT:
 737                        return dn_route_rx_short(skb);
 738                }
 739        }
 740
 741dump_it:
 742        kfree_skb(skb);
 743out:
 744        return NET_RX_DROP;
 745}
 746
 747static int dn_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 748{
 749        struct dst_entry *dst = skb_dst(skb);
 750        struct dn_route *rt = (struct dn_route *)dst;
 751        struct net_device *dev = dst->dev;
 752        struct dn_skb_cb *cb = DN_SKB_CB(skb);
 753
 754        int err = -EINVAL;
 755
 756        if (rt->n == NULL)
 757                goto error;
 758
 759        skb->dev = dev;
 760
 761        cb->src = rt->rt_saddr;
 762        cb->dst = rt->rt_daddr;
 763
 764        /*
 765         * Always set the Intra-Ethernet bit on all outgoing packets
 766         * originated on this node. Only valid flag from upper layers
 767         * is return-to-sender-requested. Set hop count to 0 too.
 768         */
 769        cb->rt_flags &= ~DN_RT_F_RQR;
 770        cb->rt_flags |= DN_RT_F_IE;
 771        cb->hops = 0;
 772
 773        return NF_HOOK(NFPROTO_DECNET, NF_DN_LOCAL_OUT,
 774                       &init_net, sk, skb, NULL, dev,
 775                       dn_to_neigh_output);
 776
 777error:
 778        net_dbg_ratelimited("dn_output: This should not happen\n");
 779
 780        kfree_skb(skb);
 781
 782        return err;
 783}
 784
 785static int dn_forward(struct sk_buff *skb)
 786{
 787        struct dn_skb_cb *cb = DN_SKB_CB(skb);
 788        struct dst_entry *dst = skb_dst(skb);
 789        struct dn_dev *dn_db = rcu_dereference(dst->dev->dn_ptr);
 790        struct dn_route *rt;
 791        int header_len;
 792        struct net_device *dev = skb->dev;
 793
 794        if (skb->pkt_type != PACKET_HOST)
 795                goto drop;
 796
 797        /* Ensure that we have enough space for headers */
 798        rt = (struct dn_route *)skb_dst(skb);
 799        header_len = dn_db->use_long ? 21 : 6;
 800        if (skb_cow(skb, LL_RESERVED_SPACE(rt->dst.dev)+header_len))
 801                goto drop;
 802
 803        /*
 804         * Hop count exceeded.
 805         */
 806        if (++cb->hops > 30)
 807                goto drop;
 808
 809        skb->dev = rt->dst.dev;
 810
 811        /*
 812         * If packet goes out same interface it came in on, then set
 813         * the Intra-Ethernet bit. This has no effect for short
 814         * packets, so we don't need to test for them here.
 815         */
 816        cb->rt_flags &= ~DN_RT_F_IE;
 817        if (rt->rt_flags & RTCF_DOREDIRECT)
 818                cb->rt_flags |= DN_RT_F_IE;
 819
 820        return NF_HOOK(NFPROTO_DECNET, NF_DN_FORWARD,
 821                       &init_net, NULL, skb, dev, skb->dev,
 822                       dn_to_neigh_output);
 823
 824drop:
 825        kfree_skb(skb);
 826        return NET_RX_DROP;
 827}
 828
 829/*
 830 * Used to catch bugs. This should never normally get
 831 * called.
 832 */
 833static int dn_rt_bug_out(struct net *net, struct sock *sk, 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 int dn_rt_bug(struct sk_buff *skb)
 846{
 847        struct dn_skb_cb *cb = DN_SKB_CB(skb);
 848
 849        net_dbg_ratelimited("dn_rt_bug: skb from:%04x to:%04x\n",
 850                            le16_to_cpu(cb->src), le16_to_cpu(cb->dst));
 851
 852        kfree_skb(skb);
 853
 854        return NET_RX_DROP;
 855}
 856
 857static unsigned int dn_dst_default_advmss(const struct dst_entry *dst)
 858{
 859        return dn_mss_from_pmtu(dst->dev, dst_mtu(dst));
 860}
 861
 862static unsigned int dn_dst_mtu(const struct dst_entry *dst)
 863{
 864        unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
 865
 866        return mtu ? : dst->dev->mtu;
 867}
 868
 869static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst,
 870                                             struct sk_buff *skb,
 871                                             const void *daddr)
 872{
 873        return __neigh_lookup_errno(&dn_neigh_table, daddr, dst->dev);
 874}
 875
 876static int dn_rt_set_next_hop(struct dn_route *rt, struct dn_fib_res *res)
 877{
 878        struct dn_fib_info *fi = res->fi;
 879        struct net_device *dev = rt->dst.dev;
 880        unsigned int mss_metric;
 881        struct neighbour *n;
 882
 883        if (fi) {
 884                if (DN_FIB_RES_GW(*res) &&
 885                    DN_FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
 886                        rt->rt_gateway = DN_FIB_RES_GW(*res);
 887                dst_init_metrics(&rt->dst, fi->fib_metrics, true);
 888        }
 889        rt->rt_type = res->type;
 890
 891        if (dev != NULL && rt->n == NULL) {
 892                n = __neigh_lookup_errno(&dn_neigh_table, &rt->rt_gateway, dev);
 893                if (IS_ERR(n))
 894                        return PTR_ERR(n);
 895                rt->n = n;
 896        }
 897
 898        if (dst_metric(&rt->dst, RTAX_MTU) > rt->dst.dev->mtu)
 899                dst_metric_set(&rt->dst, RTAX_MTU, rt->dst.dev->mtu);
 900        mss_metric = dst_metric_raw(&rt->dst, RTAX_ADVMSS);
 901        if (mss_metric) {
 902                unsigned int mss = dn_mss_from_pmtu(dev, dst_mtu(&rt->dst));
 903                if (mss_metric > mss)
 904                        dst_metric_set(&rt->dst, RTAX_ADVMSS, mss);
 905        }
 906        return 0;
 907}
 908
 909static inline int dn_match_addr(__le16 addr1, __le16 addr2)
 910{
 911        __u16 tmp = le16_to_cpu(addr1) ^ le16_to_cpu(addr2);
 912        int match = 16;
 913        while(tmp) {
 914                tmp >>= 1;
 915                match--;
 916        }
 917        return match;
 918}
 919
 920static __le16 dnet_select_source(const struct net_device *dev, __le16 daddr, int scope)
 921{
 922        __le16 saddr = 0;
 923        struct dn_dev *dn_db;
 924        struct dn_ifaddr *ifa;
 925        int best_match = 0;
 926        int ret;
 927
 928        rcu_read_lock();
 929        dn_db = rcu_dereference(dev->dn_ptr);
 930        for (ifa = rcu_dereference(dn_db->ifa_list);
 931             ifa != NULL;
 932             ifa = rcu_dereference(ifa->ifa_next)) {
 933                if (ifa->ifa_scope > scope)
 934                        continue;
 935                if (!daddr) {
 936                        saddr = ifa->ifa_local;
 937                        break;
 938                }
 939                ret = dn_match_addr(daddr, ifa->ifa_local);
 940                if (ret > best_match)
 941                        saddr = ifa->ifa_local;
 942                if (best_match == 0)
 943                        saddr = ifa->ifa_local;
 944        }
 945        rcu_read_unlock();
 946
 947        return saddr;
 948}
 949
 950static inline __le16 __dn_fib_res_prefsrc(struct dn_fib_res *res)
 951{
 952        return dnet_select_source(DN_FIB_RES_DEV(*res), DN_FIB_RES_GW(*res), res->scope);
 953}
 954
 955static inline __le16 dn_fib_rules_map_destination(__le16 daddr, struct dn_fib_res *res)
 956{
 957        __le16 mask = dnet_make_mask(res->prefixlen);
 958        return (daddr&~mask)|res->fi->fib_nh->nh_gw;
 959}
 960
 961static int dn_route_output_slow(struct dst_entry **pprt, const struct flowidn *oldflp, int try_hard)
 962{
 963        struct flowidn fld = {
 964                .daddr = oldflp->daddr,
 965                .saddr = oldflp->saddr,
 966                .flowidn_scope = RT_SCOPE_UNIVERSE,
 967                .flowidn_mark = oldflp->flowidn_mark,
 968                .flowidn_iif = LOOPBACK_IFINDEX,
 969                .flowidn_oif = oldflp->flowidn_oif,
 970        };
 971        struct dn_route *rt = NULL;
 972        struct net_device *dev_out = NULL, *dev;
 973        struct neighbour *neigh = NULL;
 974        unsigned int hash;
 975        unsigned int flags = 0;
 976        struct dn_fib_res res = { .fi = NULL, .type = RTN_UNICAST };
 977        int err;
 978        int free_res = 0;
 979        __le16 gateway = 0;
 980
 981        if (decnet_debug_level & 16)
 982                printk(KERN_DEBUG
 983                       "dn_route_output_slow: dst=%04x src=%04x mark=%d"
 984                       " iif=%d oif=%d\n", le16_to_cpu(oldflp->daddr),
 985                       le16_to_cpu(oldflp->saddr),
 986                       oldflp->flowidn_mark, LOOPBACK_IFINDEX,
 987                       oldflp->flowidn_oif);
 988
 989        /* If we have an output interface, verify its a DECnet device */
 990        if (oldflp->flowidn_oif) {
 991                dev_out = dev_get_by_index(&init_net, oldflp->flowidn_oif);
 992                err = -ENODEV;
 993                if (dev_out && dev_out->dn_ptr == NULL) {
 994                        dev_put(dev_out);
 995                        dev_out = NULL;
 996                }
 997                if (dev_out == NULL)
 998                        goto out;
 999        }
1000
1001        /* If we have a source address, verify that its a local address */
1002        if (oldflp->saddr) {
1003                err = -EADDRNOTAVAIL;
1004
1005                if (dev_out) {
1006                        if (dn_dev_islocal(dev_out, oldflp->saddr))
1007                                goto source_ok;
1008                        dev_put(dev_out);
1009                        goto out;
1010                }
1011                rcu_read_lock();
1012                for_each_netdev_rcu(&init_net, dev) {
1013                        if (!dev->dn_ptr)
1014                                continue;
1015                        if (!dn_dev_islocal(dev, oldflp->saddr))
1016                                continue;
1017                        if ((dev->flags & IFF_LOOPBACK) &&
1018                            oldflp->daddr &&
1019                            !dn_dev_islocal(dev, oldflp->daddr))
1020                                continue;
1021
1022                        dev_out = dev;
1023                        break;
1024                }
1025                rcu_read_unlock();
1026                if (dev_out == NULL)
1027                        goto out;
1028                dev_hold(dev_out);
1029source_ok:
1030                ;
1031        }
1032
1033        /* No destination? Assume its local */
1034        if (!fld.daddr) {
1035                fld.daddr = fld.saddr;
1036
1037                if (dev_out)
1038                        dev_put(dev_out);
1039                err = -EINVAL;
1040                dev_out = init_net.loopback_dev;
1041                if (!dev_out->dn_ptr)
1042                        goto out;
1043                err = -EADDRNOTAVAIL;
1044                dev_hold(dev_out);
1045                if (!fld.daddr) {
1046                        fld.daddr =
1047                        fld.saddr = dnet_select_source(dev_out, 0,
1048                                                       RT_SCOPE_HOST);
1049                        if (!fld.daddr)
1050                                goto out;
1051                }
1052                fld.flowidn_oif = LOOPBACK_IFINDEX;
1053                res.type = RTN_LOCAL;
1054                goto make_route;
1055        }
1056
1057        if (decnet_debug_level & 16)
1058                printk(KERN_DEBUG
1059                       "dn_route_output_slow: initial checks complete."
1060                       " dst=%04x src=%04x oif=%d try_hard=%d\n",
1061                       le16_to_cpu(fld.daddr), le16_to_cpu(fld.saddr),
1062                       fld.flowidn_oif, try_hard);
1063
1064        /*
1065         * N.B. If the kernel is compiled without router support then
1066         * dn_fib_lookup() will evaluate to non-zero so this if () block
1067         * will always be executed.
1068         */
1069        err = -ESRCH;
1070        if (try_hard || (err = dn_fib_lookup(&fld, &res)) != 0) {
1071                struct dn_dev *dn_db;
1072                if (err != -ESRCH)
1073                        goto out;
1074                /*
1075                 * Here the fallback is basically the standard algorithm for
1076                 * routing in endnodes which is described in the DECnet routing
1077                 * docs
1078                 *
1079                 * If we are not trying hard, look in neighbour cache.
1080                 * The result is tested to ensure that if a specific output
1081                 * device/source address was requested, then we honour that
1082                 * here
1083                 */
1084                if (!try_hard) {
1085                        neigh = neigh_lookup_nodev(&dn_neigh_table, &init_net, &fld.daddr);
1086                        if (neigh) {
1087                                if ((oldflp->flowidn_oif &&
1088                                    (neigh->dev->ifindex != oldflp->flowidn_oif)) ||
1089                                    (oldflp->saddr &&
1090                                    (!dn_dev_islocal(neigh->dev,
1091                                                     oldflp->saddr)))) {
1092                                        neigh_release(neigh);
1093                                        neigh = NULL;
1094                                } else {
1095                                        if (dev_out)
1096                                                dev_put(dev_out);
1097                                        if (dn_dev_islocal(neigh->dev, fld.daddr)) {
1098                                                dev_out = init_net.loopback_dev;
1099                                                res.type = RTN_LOCAL;
1100                                        } else {
1101                                                dev_out = neigh->dev;
1102                                        }
1103                                        dev_hold(dev_out);
1104                                        goto select_source;
1105                                }
1106                        }
1107                }
1108
1109                /* Not there? Perhaps its a local address */
1110                if (dev_out == NULL)
1111                        dev_out = dn_dev_get_default();
1112                err = -ENODEV;
1113                if (dev_out == NULL)
1114                        goto out;
1115                dn_db = rcu_dereference_raw(dev_out->dn_ptr);
1116                if (!dn_db)
1117                        goto e_inval;
1118                /* Possible improvement - check all devices for local addr */
1119                if (dn_dev_islocal(dev_out, fld.daddr)) {
1120                        dev_put(dev_out);
1121                        dev_out = init_net.loopback_dev;
1122                        dev_hold(dev_out);
1123                        res.type = RTN_LOCAL;
1124                        goto select_source;
1125                }
1126                /* Not local either.... try sending it to the default router */
1127                neigh = neigh_clone(dn_db->router);
1128                BUG_ON(neigh && neigh->dev != dev_out);
1129
1130                /* Ok then, we assume its directly connected and move on */
1131select_source:
1132                if (neigh)
1133                        gateway = ((struct dn_neigh *)neigh)->addr;
1134                if (gateway == 0)
1135                        gateway = fld.daddr;
1136                if (fld.saddr == 0) {
1137                        fld.saddr = dnet_select_source(dev_out, gateway,
1138                                                       res.type == RTN_LOCAL ?
1139                                                       RT_SCOPE_HOST :
1140                                                       RT_SCOPE_LINK);
1141                        if (fld.saddr == 0 && res.type != RTN_LOCAL)
1142                                goto e_addr;
1143                }
1144                fld.flowidn_oif = dev_out->ifindex;
1145                goto make_route;
1146        }
1147        free_res = 1;
1148
1149        if (res.type == RTN_NAT)
1150                goto e_inval;
1151
1152        if (res.type == RTN_LOCAL) {
1153                if (!fld.saddr)
1154                        fld.saddr = fld.daddr;
1155                if (dev_out)
1156                        dev_put(dev_out);
1157                dev_out = init_net.loopback_dev;
1158                dev_hold(dev_out);
1159                if (!dev_out->dn_ptr)
1160                        goto e_inval;
1161                fld.flowidn_oif = dev_out->ifindex;
1162                if (res.fi)
1163                        dn_fib_info_put(res.fi);
1164                res.fi = NULL;
1165                goto make_route;
1166        }
1167
1168        if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1169                dn_fib_select_multipath(&fld, &res);
1170
1171        /*
1172         * We could add some logic to deal with default routes here and
1173         * get rid of some of the special casing above.
1174         */
1175
1176        if (!fld.saddr)
1177                fld.saddr = DN_FIB_RES_PREFSRC(res);
1178
1179        if (dev_out)
1180                dev_put(dev_out);
1181        dev_out = DN_FIB_RES_DEV(res);
1182        dev_hold(dev_out);
1183        fld.flowidn_oif = dev_out->ifindex;
1184        gateway = DN_FIB_RES_GW(res);
1185
1186make_route:
1187        if (dev_out->flags & IFF_LOOPBACK)
1188                flags |= RTCF_LOCAL;
1189
1190        rt = dst_alloc(&dn_dst_ops, dev_out, 1, DST_OBSOLETE_NONE, DST_HOST);
1191        if (rt == NULL)
1192                goto e_nobufs;
1193
1194        memset(&rt->fld, 0, sizeof(rt->fld));
1195        rt->fld.saddr        = oldflp->saddr;
1196        rt->fld.daddr        = oldflp->daddr;
1197        rt->fld.flowidn_oif  = oldflp->flowidn_oif;
1198        rt->fld.flowidn_iif  = 0;
1199        rt->fld.flowidn_mark = oldflp->flowidn_mark;
1200
1201        rt->rt_saddr      = fld.saddr;
1202        rt->rt_daddr      = fld.daddr;
1203        rt->rt_gateway    = gateway ? gateway : fld.daddr;
1204        rt->rt_local_src  = fld.saddr;
1205
1206        rt->rt_dst_map    = fld.daddr;
1207        rt->rt_src_map    = fld.saddr;
1208
1209        rt->n = neigh;
1210        neigh = NULL;
1211
1212        rt->dst.lastuse = jiffies;
1213        rt->dst.output  = dn_output;
1214        rt->dst.input   = dn_rt_bug;
1215        rt->rt_flags      = flags;
1216        if (flags & RTCF_LOCAL)
1217                rt->dst.input = dn_nsp_rx;
1218
1219        err = dn_rt_set_next_hop(rt, &res);
1220        if (err)
1221                goto e_neighbour;
1222
1223        hash = dn_hash(rt->fld.saddr, rt->fld.daddr);
1224        dn_insert_route(rt, hash, (struct dn_route **)pprt);
1225
1226done:
1227        if (neigh)
1228                neigh_release(neigh);
1229        if (free_res)
1230                dn_fib_res_put(&res);
1231        if (dev_out)
1232                dev_put(dev_out);
1233out:
1234        return err;
1235
1236e_addr:
1237        err = -EADDRNOTAVAIL;
1238        goto done;
1239e_inval:
1240        err = -EINVAL;
1241        goto done;
1242e_nobufs:
1243        err = -ENOBUFS;
1244        goto done;
1245e_neighbour:
1246        dst_free(&rt->dst);
1247        goto e_nobufs;
1248}
1249
1250
1251/*
1252 * N.B. The flags may be moved into the flowi at some future stage.
1253 */
1254static int __dn_route_output_key(struct dst_entry **pprt, const struct flowidn *flp, int flags)
1255{
1256        unsigned int hash = dn_hash(flp->saddr, flp->daddr);
1257        struct dn_route *rt = NULL;
1258
1259        if (!(flags & MSG_TRYHARD)) {
1260                rcu_read_lock_bh();
1261                for (rt = rcu_dereference_bh(dn_rt_hash_table[hash].chain); rt;
1262                        rt = rcu_dereference_bh(rt->dst.dn_next)) {
1263                        if ((flp->daddr == rt->fld.daddr) &&
1264                            (flp->saddr == rt->fld.saddr) &&
1265                            (flp->flowidn_mark == rt->fld.flowidn_mark) &&
1266                            dn_is_output_route(rt) &&
1267                            (rt->fld.flowidn_oif == flp->flowidn_oif)) {
1268                                dst_use(&rt->dst, jiffies);
1269                                rcu_read_unlock_bh();
1270                                *pprt = &rt->dst;
1271                                return 0;
1272                        }
1273                }
1274                rcu_read_unlock_bh();
1275        }
1276
1277        return dn_route_output_slow(pprt, flp, flags);
1278}
1279
1280static int dn_route_output_key(struct dst_entry **pprt, struct flowidn *flp, int flags)
1281{
1282        int err;
1283
1284        err = __dn_route_output_key(pprt, flp, flags);
1285        if (err == 0 && flp->flowidn_proto) {
1286                *pprt = xfrm_lookup(&init_net, *pprt,
1287                                    flowidn_to_flowi(flp), NULL, 0);
1288                if (IS_ERR(*pprt)) {
1289                        err = PTR_ERR(*pprt);
1290                        *pprt = NULL;
1291                }
1292        }
1293        return err;
1294}
1295
1296int dn_route_output_sock(struct dst_entry __rcu **pprt, struct flowidn *fl, struct sock *sk, int flags)
1297{
1298        int err;
1299
1300        err = __dn_route_output_key(pprt, fl, flags & MSG_TRYHARD);
1301        if (err == 0 && fl->flowidn_proto) {
1302                *pprt = xfrm_lookup(&init_net, *pprt,
1303                                    flowidn_to_flowi(fl), sk, 0);
1304                if (IS_ERR(*pprt)) {
1305                        err = PTR_ERR(*pprt);
1306                        *pprt = NULL;
1307                }
1308        }
1309        return err;
1310}
1311
1312static int dn_route_input_slow(struct sk_buff *skb)
1313{
1314        struct dn_route *rt = NULL;
1315        struct dn_skb_cb *cb = DN_SKB_CB(skb);
1316        struct net_device *in_dev = skb->dev;
1317        struct net_device *out_dev = NULL;
1318        struct dn_dev *dn_db;
1319        struct neighbour *neigh = NULL;
1320        unsigned int hash;
1321        int flags = 0;
1322        __le16 gateway = 0;
1323        __le16 local_src = 0;
1324        struct flowidn fld = {
1325                .daddr = cb->dst,
1326                .saddr = cb->src,
1327                .flowidn_scope = RT_SCOPE_UNIVERSE,
1328                .flowidn_mark = skb->mark,
1329                .flowidn_iif = skb->dev->ifindex,
1330        };
1331        struct dn_fib_res res = { .fi = NULL, .type = RTN_UNREACHABLE };
1332        int err = -EINVAL;
1333        int free_res = 0;
1334
1335        dev_hold(in_dev);
1336
1337        if ((dn_db = rcu_dereference(in_dev->dn_ptr)) == NULL)
1338                goto out;
1339
1340        /* Zero source addresses are not allowed */
1341        if (fld.saddr == 0)
1342                goto out;
1343
1344        /*
1345         * In this case we've just received a packet from a source
1346         * outside ourselves pretending to come from us. We don't
1347         * allow it any further to prevent routing loops, spoofing and
1348         * other nasties. Loopback packets already have the dst attached
1349         * so this only affects packets which have originated elsewhere.
1350         */
1351        err  = -ENOTUNIQ;
1352        if (dn_dev_islocal(in_dev, cb->src))
1353                goto out;
1354
1355        err = dn_fib_lookup(&fld, &res);
1356        if (err) {
1357                if (err != -ESRCH)
1358                        goto out;
1359                /*
1360                 * Is the destination us ?
1361                 */
1362                if (!dn_dev_islocal(in_dev, cb->dst))
1363                        goto e_inval;
1364
1365                res.type = RTN_LOCAL;
1366        } else {
1367                __le16 src_map = fld.saddr;
1368                free_res = 1;
1369
1370                out_dev = DN_FIB_RES_DEV(res);
1371                if (out_dev == NULL) {
1372                        net_crit_ratelimited("Bug in dn_route_input_slow() No output device\n");
1373                        goto e_inval;
1374                }
1375                dev_hold(out_dev);
1376
1377                if (res.r)
1378                        src_map = fld.saddr; /* no NAT support for now */
1379
1380                gateway = DN_FIB_RES_GW(res);
1381                if (res.type == RTN_NAT) {
1382                        fld.daddr = dn_fib_rules_map_destination(fld.daddr, &res);
1383                        dn_fib_res_put(&res);
1384                        free_res = 0;
1385                        if (dn_fib_lookup(&fld, &res))
1386                                goto e_inval;
1387                        free_res = 1;
1388                        if (res.type != RTN_UNICAST)
1389                                goto e_inval;
1390                        flags |= RTCF_DNAT;
1391                        gateway = fld.daddr;
1392                }
1393                fld.saddr = src_map;
1394        }
1395
1396        switch(res.type) {
1397        case RTN_UNICAST:
1398                /*
1399                 * Forwarding check here, we only check for forwarding
1400                 * being turned off, if you want to only forward intra
1401                 * area, its up to you to set the routing tables up
1402                 * correctly.
1403                 */
1404                if (dn_db->parms.forwarding == 0)
1405                        goto e_inval;
1406
1407                if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1408                        dn_fib_select_multipath(&fld, &res);
1409
1410                /*
1411                 * Check for out_dev == in_dev. We use the RTCF_DOREDIRECT
1412                 * flag as a hint to set the intra-ethernet bit when
1413                 * forwarding. If we've got NAT in operation, we don't do
1414                 * this optimisation.
1415                 */
1416                if (out_dev == in_dev && !(flags & RTCF_NAT))
1417                        flags |= RTCF_DOREDIRECT;
1418
1419                local_src = DN_FIB_RES_PREFSRC(res);
1420
1421        case RTN_BLACKHOLE:
1422        case RTN_UNREACHABLE:
1423                break;
1424        case RTN_LOCAL:
1425                flags |= RTCF_LOCAL;
1426                fld.saddr = cb->dst;
1427                fld.daddr = cb->src;
1428
1429                /* Routing tables gave us a gateway */
1430                if (gateway)
1431                        goto make_route;
1432
1433                /* Packet was intra-ethernet, so we know its on-link */
1434                if (cb->rt_flags & DN_RT_F_IE) {
1435                        gateway = cb->src;
1436                        goto make_route;
1437                }
1438
1439                /* Use the default router if there is one */
1440                neigh = neigh_clone(dn_db->router);
1441                if (neigh) {
1442                        gateway = ((struct dn_neigh *)neigh)->addr;
1443                        goto make_route;
1444                }
1445
1446                /* Close eyes and pray */
1447                gateway = cb->src;
1448                goto make_route;
1449        default:
1450                goto e_inval;
1451        }
1452
1453make_route:
1454        rt = dst_alloc(&dn_dst_ops, out_dev, 0, DST_OBSOLETE_NONE, DST_HOST);
1455        if (rt == NULL)
1456                goto e_nobufs;
1457
1458        memset(&rt->fld, 0, sizeof(rt->fld));
1459        rt->rt_saddr      = fld.saddr;
1460        rt->rt_daddr      = fld.daddr;
1461        rt->rt_gateway    = fld.daddr;
1462        if (gateway)
1463                rt->rt_gateway = gateway;
1464        rt->rt_local_src  = local_src ? local_src : rt->rt_saddr;
1465
1466        rt->rt_dst_map    = fld.daddr;
1467        rt->rt_src_map    = fld.saddr;
1468
1469        rt->fld.saddr        = cb->src;
1470        rt->fld.daddr        = cb->dst;
1471        rt->fld.flowidn_oif  = 0;
1472        rt->fld.flowidn_iif  = in_dev->ifindex;
1473        rt->fld.flowidn_mark = fld.flowidn_mark;
1474
1475        rt->n = neigh;
1476        rt->dst.lastuse = jiffies;
1477        rt->dst.output = dn_rt_bug_out;
1478        switch (res.type) {
1479        case RTN_UNICAST:
1480                rt->dst.input = dn_forward;
1481                break;
1482        case RTN_LOCAL:
1483                rt->dst.output = dn_output;
1484                rt->dst.input = dn_nsp_rx;
1485                rt->dst.dev = in_dev;
1486                flags |= RTCF_LOCAL;
1487                break;
1488        default:
1489        case RTN_UNREACHABLE:
1490        case RTN_BLACKHOLE:
1491                rt->dst.input = dst_discard;
1492        }
1493        rt->rt_flags = flags;
1494
1495        err = dn_rt_set_next_hop(rt, &res);
1496        if (err)
1497                goto e_neighbour;
1498
1499        hash = dn_hash(rt->fld.saddr, rt->fld.daddr);
1500        dn_insert_route(rt, hash, &rt);
1501        skb_dst_set(skb, &rt->dst);
1502
1503done:
1504        if (neigh)
1505                neigh_release(neigh);
1506        if (free_res)
1507                dn_fib_res_put(&res);
1508        dev_put(in_dev);
1509        if (out_dev)
1510                dev_put(out_dev);
1511out:
1512        return err;
1513
1514e_inval:
1515        err = -EINVAL;
1516        goto done;
1517
1518e_nobufs:
1519        err = -ENOBUFS;
1520        goto done;
1521
1522e_neighbour:
1523        dst_free(&rt->dst);
1524        goto done;
1525}
1526
1527static int dn_route_input(struct sk_buff *skb)
1528{
1529        struct dn_route *rt;
1530        struct dn_skb_cb *cb = DN_SKB_CB(skb);
1531        unsigned int hash = dn_hash(cb->src, cb->dst);
1532
1533        if (skb_dst(skb))
1534                return 0;
1535
1536        rcu_read_lock();
1537        for(rt = rcu_dereference(dn_rt_hash_table[hash].chain); rt != NULL;
1538            rt = rcu_dereference(rt->dst.dn_next)) {
1539                if ((rt->fld.saddr == cb->src) &&
1540                    (rt->fld.daddr == cb->dst) &&
1541                    (rt->fld.flowidn_oif == 0) &&
1542                    (rt->fld.flowidn_mark == skb->mark) &&
1543                    (rt->fld.flowidn_iif == cb->iif)) {
1544                        dst_use(&rt->dst, jiffies);
1545                        rcu_read_unlock();
1546                        skb_dst_set(skb, (struct dst_entry *)rt);
1547                        return 0;
1548                }
1549        }
1550        rcu_read_unlock();
1551
1552        return dn_route_input_slow(skb);
1553}
1554
1555static int dn_rt_fill_info(struct sk_buff *skb, u32 portid, u32 seq,
1556                           int event, int nowait, unsigned int flags)
1557{
1558        struct dn_route *rt = (struct dn_route *)skb_dst(skb);
1559        struct rtmsg *r;
1560        struct nlmsghdr *nlh;
1561        long expires;
1562
1563        nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
1564        if (!nlh)
1565                return -EMSGSIZE;
1566
1567        r = nlmsg_data(nlh);
1568        r->rtm_family = AF_DECnet;
1569        r->rtm_dst_len = 16;
1570        r->rtm_src_len = 0;
1571        r->rtm_tos = 0;
1572        r->rtm_table = RT_TABLE_MAIN;
1573        r->rtm_type = rt->rt_type;
1574        r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
1575        r->rtm_scope = RT_SCOPE_UNIVERSE;
1576        r->rtm_protocol = RTPROT_UNSPEC;
1577
1578        if (rt->rt_flags & RTCF_NOTIFY)
1579                r->rtm_flags |= RTM_F_NOTIFY;
1580
1581        if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN) < 0 ||
1582            nla_put_le16(skb, RTA_DST, rt->rt_daddr) < 0)
1583                goto errout;
1584
1585        if (rt->fld.saddr) {
1586                r->rtm_src_len = 16;
1587                if (nla_put_le16(skb, RTA_SRC, rt->fld.saddr) < 0)
1588                        goto errout;
1589        }
1590        if (rt->dst.dev &&
1591            nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex) < 0)
1592                goto errout;
1593
1594        /*
1595         * Note to self - change this if input routes reverse direction when
1596         * they deal only with inputs and not with replies like they do
1597         * currently.
1598         */
1599        if (nla_put_le16(skb, RTA_PREFSRC, rt->rt_local_src) < 0)
1600                goto errout;
1601
1602        if (rt->rt_daddr != rt->rt_gateway &&
1603            nla_put_le16(skb, RTA_GATEWAY, rt->rt_gateway) < 0)
1604                goto errout;
1605
1606        if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
1607                goto errout;
1608
1609        expires = rt->dst.expires ? rt->dst.expires - jiffies : 0;
1610        if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires,
1611                               rt->dst.error) < 0)
1612                goto errout;
1613
1614        if (dn_is_input_route(rt) &&
1615            nla_put_u32(skb, RTA_IIF, rt->fld.flowidn_iif) < 0)
1616                goto errout;
1617
1618        nlmsg_end(skb, nlh);
1619        return 0;
1620
1621errout:
1622        nlmsg_cancel(skb, nlh);
1623        return -EMSGSIZE;
1624}
1625
1626const struct nla_policy rtm_dn_policy[RTA_MAX + 1] = {
1627        [RTA_DST]               = { .type = NLA_U16 },
1628        [RTA_SRC]               = { .type = NLA_U16 },
1629        [RTA_IIF]               = { .type = NLA_U32 },
1630        [RTA_OIF]               = { .type = NLA_U32 },
1631        [RTA_GATEWAY]           = { .type = NLA_U16 },
1632        [RTA_PRIORITY]          = { .type = NLA_U32 },
1633        [RTA_PREFSRC]           = { .type = NLA_U16 },
1634        [RTA_METRICS]           = { .type = NLA_NESTED },
1635        [RTA_MULTIPATH]         = { .type = NLA_NESTED },
1636        [RTA_TABLE]             = { .type = NLA_U32 },
1637        [RTA_MARK]              = { .type = NLA_U32 },
1638};
1639
1640/*
1641 * This is called by both endnodes and routers now.
1642 */
1643static int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
1644{
1645        struct net *net = sock_net(in_skb->sk);
1646        struct rtmsg *rtm = nlmsg_data(nlh);
1647        struct dn_route *rt = NULL;
1648        struct dn_skb_cb *cb;
1649        int err;
1650        struct sk_buff *skb;
1651        struct flowidn fld;
1652        struct nlattr *tb[RTA_MAX+1];
1653
1654        if (!net_eq(net, &init_net))
1655                return -EINVAL;
1656
1657        err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_dn_policy);
1658        if (err < 0)
1659                return err;
1660
1661        memset(&fld, 0, sizeof(fld));
1662        fld.flowidn_proto = DNPROTO_NSP;
1663
1664        skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1665        if (skb == NULL)
1666                return -ENOBUFS;
1667        skb_reset_mac_header(skb);
1668        cb = DN_SKB_CB(skb);
1669
1670        if (tb[RTA_SRC])
1671                fld.saddr = nla_get_le16(tb[RTA_SRC]);
1672
1673        if (tb[RTA_DST])
1674                fld.daddr = nla_get_le16(tb[RTA_DST]);
1675
1676        if (tb[RTA_IIF])
1677                fld.flowidn_iif = nla_get_u32(tb[RTA_IIF]);
1678
1679        if (fld.flowidn_iif) {
1680                struct net_device *dev;
1681                dev = __dev_get_by_index(&init_net, fld.flowidn_iif);
1682                if (!dev || !dev->dn_ptr) {
1683                        kfree_skb(skb);
1684                        return -ENODEV;
1685                }
1686                skb->protocol = htons(ETH_P_DNA_RT);
1687                skb->dev = dev;
1688                cb->src = fld.saddr;
1689                cb->dst = fld.daddr;
1690                local_bh_disable();
1691                err = dn_route_input(skb);
1692                local_bh_enable();
1693                memset(cb, 0, sizeof(struct dn_skb_cb));
1694                rt = (struct dn_route *)skb_dst(skb);
1695                if (!err && -rt->dst.error)
1696                        err = rt->dst.error;
1697        } else {
1698                if (tb[RTA_OIF])
1699                        fld.flowidn_oif = nla_get_u32(tb[RTA_OIF]);
1700
1701                err = dn_route_output_key((struct dst_entry **)&rt, &fld, 0);
1702        }
1703
1704        skb->dev = NULL;
1705        if (err)
1706                goto out_free;
1707        skb_dst_set(skb, &rt->dst);
1708        if (rtm->rtm_flags & RTM_F_NOTIFY)
1709                rt->rt_flags |= RTCF_NOTIFY;
1710
1711        err = dn_rt_fill_info(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, RTM_NEWROUTE, 0, 0);
1712        if (err < 0) {
1713                err = -EMSGSIZE;
1714                goto out_free;
1715        }
1716
1717        return rtnl_unicast(skb, &init_net, NETLINK_CB(in_skb).portid);
1718
1719out_free:
1720        kfree_skb(skb);
1721        return err;
1722}
1723
1724/*
1725 * For routers, this is called from dn_fib_dump, but for endnodes its
1726 * called directly from the rtnetlink dispatch table.
1727 */
1728int dn_cache_dump(struct sk_buff *skb, struct netlink_callback *cb)
1729{
1730        struct net *net = sock_net(skb->sk);
1731        struct dn_route *rt;
1732        int h, s_h;
1733        int idx, s_idx;
1734        struct rtmsg *rtm;
1735
1736        if (!net_eq(net, &init_net))
1737                return 0;
1738
1739        if (nlmsg_len(cb->nlh) < sizeof(struct rtmsg))
1740                return -EINVAL;
1741
1742        rtm = nlmsg_data(cb->nlh);
1743        if (!(rtm->rtm_flags & RTM_F_CLONED))
1744                return 0;
1745
1746        s_h = cb->args[0];
1747        s_idx = idx = cb->args[1];
1748        for(h = 0; h <= dn_rt_hash_mask; h++) {
1749                if (h < s_h)
1750                        continue;
1751                if (h > s_h)
1752                        s_idx = 0;
1753                rcu_read_lock_bh();
1754                for(rt = rcu_dereference_bh(dn_rt_hash_table[h].chain), idx = 0;
1755                        rt;
1756                        rt = rcu_dereference_bh(rt->dst.dn_next), idx++) {
1757                        if (idx < s_idx)
1758                                continue;
1759                        skb_dst_set(skb, dst_clone(&rt->dst));
1760                        if (dn_rt_fill_info(skb, NETLINK_CB(cb->skb).portid,
1761                                        cb->nlh->nlmsg_seq, RTM_NEWROUTE,
1762                                        1, NLM_F_MULTI) < 0) {
1763                                skb_dst_drop(skb);
1764                                rcu_read_unlock_bh();
1765                                goto done;
1766                        }
1767                        skb_dst_drop(skb);
1768                }
1769                rcu_read_unlock_bh();
1770        }
1771
1772done:
1773        cb->args[0] = h;
1774        cb->args[1] = idx;
1775        return skb->len;
1776}
1777
1778#ifdef CONFIG_PROC_FS
1779struct dn_rt_cache_iter_state {
1780        int bucket;
1781};
1782
1783static struct dn_route *dn_rt_cache_get_first(struct seq_file *seq)
1784{
1785        struct dn_route *rt = NULL;
1786        struct dn_rt_cache_iter_state *s = seq->private;
1787
1788        for(s->bucket = dn_rt_hash_mask; s->bucket >= 0; --s->bucket) {
1789                rcu_read_lock_bh();
1790                rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1791                if (rt)
1792                        break;
1793                rcu_read_unlock_bh();
1794        }
1795        return rt;
1796}
1797
1798static struct dn_route *dn_rt_cache_get_next(struct seq_file *seq, struct dn_route *rt)
1799{
1800        struct dn_rt_cache_iter_state *s = seq->private;
1801
1802        rt = rcu_dereference_bh(rt->dst.dn_next);
1803        while (!rt) {
1804                rcu_read_unlock_bh();
1805                if (--s->bucket < 0)
1806                        break;
1807                rcu_read_lock_bh();
1808                rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1809        }
1810        return rt;
1811}
1812
1813static void *dn_rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
1814{
1815        struct dn_route *rt = dn_rt_cache_get_first(seq);
1816
1817        if (rt) {
1818                while(*pos && (rt = dn_rt_cache_get_next(seq, rt)))
1819                        --*pos;
1820        }
1821        return *pos ? NULL : rt;
1822}
1823
1824static void *dn_rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1825{
1826        struct dn_route *rt = dn_rt_cache_get_next(seq, v);
1827        ++*pos;
1828        return rt;
1829}
1830
1831static void dn_rt_cache_seq_stop(struct seq_file *seq, void *v)
1832{
1833        if (v)
1834                rcu_read_unlock_bh();
1835}
1836
1837static int dn_rt_cache_seq_show(struct seq_file *seq, void *v)
1838{
1839        struct dn_route *rt = v;
1840        char buf1[DN_ASCBUF_LEN], buf2[DN_ASCBUF_LEN];
1841
1842        seq_printf(seq, "%-8s %-7s %-7s %04d %04d %04d\n",
1843                   rt->dst.dev ? rt->dst.dev->name : "*",
1844                   dn_addr2asc(le16_to_cpu(rt->rt_daddr), buf1),
1845                   dn_addr2asc(le16_to_cpu(rt->rt_saddr), buf2),
1846                   atomic_read(&rt->dst.__refcnt),
1847                   rt->dst.__use, 0);
1848        return 0;
1849}
1850
1851static const struct seq_operations dn_rt_cache_seq_ops = {
1852        .start  = dn_rt_cache_seq_start,
1853        .next   = dn_rt_cache_seq_next,
1854        .stop   = dn_rt_cache_seq_stop,
1855        .show   = dn_rt_cache_seq_show,
1856};
1857
1858static int dn_rt_cache_seq_open(struct inode *inode, struct file *file)
1859{
1860        return seq_open_private(file, &dn_rt_cache_seq_ops,
1861                        sizeof(struct dn_rt_cache_iter_state));
1862}
1863
1864static const struct file_operations dn_rt_cache_seq_fops = {
1865        .owner   = THIS_MODULE,
1866        .open    = dn_rt_cache_seq_open,
1867        .read    = seq_read,
1868        .llseek  = seq_lseek,
1869        .release = seq_release_private,
1870};
1871
1872#endif /* CONFIG_PROC_FS */
1873
1874void __init dn_route_init(void)
1875{
1876        int i, goal, order;
1877
1878        dn_dst_ops.kmem_cachep =
1879                kmem_cache_create("dn_dst_cache", sizeof(struct dn_route), 0,
1880                                  SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
1881        dst_entries_init(&dn_dst_ops);
1882        setup_timer(&dn_route_timer, dn_dst_check_expire, 0);
1883        dn_route_timer.expires = jiffies + decnet_dst_gc_interval * HZ;
1884        add_timer(&dn_route_timer);
1885
1886        goal = totalram_pages >> (26 - PAGE_SHIFT);
1887
1888        for(order = 0; (1UL << order) < goal; order++)
1889                /* NOTHING */;
1890
1891        /*
1892         * Only want 1024 entries max, since the table is very, very unlikely
1893         * to be larger than that.
1894         */
1895        while(order && ((((1UL << order) * PAGE_SIZE) /
1896                                sizeof(struct dn_rt_hash_bucket)) >= 2048))
1897                order--;
1898
1899        do {
1900                dn_rt_hash_mask = (1UL << order) * PAGE_SIZE /
1901                        sizeof(struct dn_rt_hash_bucket);
1902                while(dn_rt_hash_mask & (dn_rt_hash_mask - 1))
1903                        dn_rt_hash_mask--;
1904                dn_rt_hash_table = (struct dn_rt_hash_bucket *)
1905                        __get_free_pages(GFP_ATOMIC, order);
1906        } while (dn_rt_hash_table == NULL && --order > 0);
1907
1908        if (!dn_rt_hash_table)
1909                panic("Failed to allocate DECnet route cache hash table\n");
1910
1911        printk(KERN_INFO
1912                "DECnet: Routing cache hash table of %u buckets, %ldKbytes\n",
1913                dn_rt_hash_mask,
1914                (long)(dn_rt_hash_mask*sizeof(struct dn_rt_hash_bucket))/1024);
1915
1916        dn_rt_hash_mask--;
1917        for(i = 0; i <= dn_rt_hash_mask; i++) {
1918                spin_lock_init(&dn_rt_hash_table[i].lock);
1919                dn_rt_hash_table[i].chain = NULL;
1920        }
1921
1922        dn_dst_ops.gc_thresh = (dn_rt_hash_mask + 1);
1923
1924        proc_create("decnet_cache", S_IRUGO, init_net.proc_net,
1925                    &dn_rt_cache_seq_fops);
1926
1927#ifdef CONFIG_DECNET_ROUTER
1928        rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute,
1929                      dn_fib_dump, NULL);
1930#else
1931        rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute,
1932                      dn_cache_dump, NULL);
1933#endif
1934}
1935
1936void __exit dn_route_cleanup(void)
1937{
1938        del_timer(&dn_route_timer);
1939        dn_run_flush(0);
1940
1941        remove_proc_entry("decnet_cache", init_net.proc_net);
1942        dst_entries_destroy(&dn_dst_ops);
1943}
1944
1945