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        .protocol =             cpu_to_be16(ETH_P_DNA_RT),
 140        .gc_thresh =            128,
 141        .gc =                   dn_dst_gc,
 142        .check =                dn_dst_check,
 143        .default_advmss =       dn_dst_default_advmss,
 144        .mtu =                  dn_dst_mtu,
 145        .cow_metrics =          dst_cow_metrics_generic,
 146        .destroy =              dn_dst_destroy,
 147        .ifdown =               dn_dst_ifdown,
 148        .negative_advice =      dn_dst_negative_advice,
 149        .link_failure =         dn_dst_link_failure,
 150        .update_pmtu =          dn_dst_update_pmtu,
 151        .redirect =             dn_dst_redirect,
 152        .neigh_lookup =         dn_dst_neigh_lookup,
 153};
 154
 155static void dn_dst_destroy(struct dst_entry *dst)
 156{
 157        struct dn_route *rt = (struct dn_route *) dst;
 158
 159        if (rt->n)
 160                neigh_release(rt->n);
 161        dst_destroy_metrics_generic(dst);
 162}
 163
 164static void dn_dst_ifdown(struct dst_entry *dst, struct net_device *dev, int how)
 165{
 166        if (how) {
 167                struct dn_route *rt = (struct dn_route *) dst;
 168                struct neighbour *n = rt->n;
 169
 170                if (n && n->dev == dev) {
 171                        n->dev = dev_net(dev)->loopback_dev;
 172                        dev_hold(n->dev);
 173                        dev_put(dev);
 174                }
 175        }
 176}
 177
 178static __inline__ unsigned int dn_hash(__le16 src, __le16 dst)
 179{
 180        __u16 tmp = (__u16 __force)(src ^ dst);
 181        tmp ^= (tmp >> 3);
 182        tmp ^= (tmp >> 5);
 183        tmp ^= (tmp >> 10);
 184        return dn_rt_hash_mask & (unsigned int)tmp;
 185}
 186
 187static inline void dnrt_free(struct dn_route *rt)
 188{
 189        call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
 190}
 191
 192static inline void dnrt_drop(struct dn_route *rt)
 193{
 194        dst_release(&rt->dst);
 195        call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
 196}
 197
 198static void dn_dst_check_expire(unsigned long dummy)
 199{
 200        int i;
 201        struct dn_route *rt;
 202        struct dn_route __rcu **rtp;
 203        unsigned long now = jiffies;
 204        unsigned long expire = 120 * HZ;
 205
 206        for (i = 0; i <= dn_rt_hash_mask; i++) {
 207                rtp = &dn_rt_hash_table[i].chain;
 208
 209                spin_lock(&dn_rt_hash_table[i].lock);
 210                while ((rt = rcu_dereference_protected(*rtp,
 211                                                lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) {
 212                        if (atomic_read(&rt->dst.__refcnt) ||
 213                                        (now - rt->dst.lastuse) < expire) {
 214                                rtp = &rt->dst.dn_next;
 215                                continue;
 216                        }
 217                        *rtp = rt->dst.dn_next;
 218                        rt->dst.dn_next = NULL;
 219                        dnrt_free(rt);
 220                }
 221                spin_unlock(&dn_rt_hash_table[i].lock);
 222
 223                if ((jiffies - now) > 0)
 224                        break;
 225        }
 226
 227        mod_timer(&dn_route_timer, now + decnet_dst_gc_interval * HZ);
 228}
 229
 230static int dn_dst_gc(struct dst_ops *ops)
 231{
 232        struct dn_route *rt;
 233        struct dn_route __rcu **rtp;
 234        int i;
 235        unsigned long now = jiffies;
 236        unsigned long expire = 10 * HZ;
 237
 238        for (i = 0; i <= dn_rt_hash_mask; i++) {
 239
 240                spin_lock_bh(&dn_rt_hash_table[i].lock);
 241                rtp = &dn_rt_hash_table[i].chain;
 242
 243                while ((rt = rcu_dereference_protected(*rtp,
 244                                                lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) {
 245                        if (atomic_read(&rt->dst.__refcnt) ||
 246                                        (now - rt->dst.lastuse) < expire) {
 247                                rtp = &rt->dst.dn_next;
 248                                continue;
 249                        }
 250                        *rtp = rt->dst.dn_next;
 251                        rt->dst.dn_next = NULL;
 252                        dnrt_drop(rt);
 253                        break;
 254                }
 255                spin_unlock_bh(&dn_rt_hash_table[i].lock);
 256        }
 257
 258        return 0;
 259}
 260
 261/*
 262 * The decnet standards don't impose a particular minimum mtu, what they
 263 * do insist on is that the routing layer accepts a datagram of at least
 264 * 230 bytes long. Here we have to subtract the routing header length from
 265 * 230 to get the minimum acceptable mtu. If there is no neighbour, then we
 266 * assume the worst and use a long header size.
 267 *
 268 * We update both the mtu and the advertised mss (i.e. the segment size we
 269 * advertise to the other end).
 270 */
 271static void dn_dst_update_pmtu(struct dst_entry *dst, struct sock *sk,
 272                               struct sk_buff *skb, u32 mtu)
 273{
 274        struct dn_route *rt = (struct dn_route *) dst;
 275        struct neighbour *n = rt->n;
 276        u32 min_mtu = 230;
 277        struct dn_dev *dn;
 278
 279        dn = n ? rcu_dereference_raw(n->dev->dn_ptr) : NULL;
 280
 281        if (dn && dn->use_long == 0)
 282                min_mtu -= 6;
 283        else
 284                min_mtu -= 21;
 285
 286        if (dst_metric(dst, RTAX_MTU) > mtu && mtu >= min_mtu) {
 287                if (!(dst_metric_locked(dst, RTAX_MTU))) {
 288                        dst_metric_set(dst, RTAX_MTU, mtu);
 289                        dst_set_expires(dst, dn_rt_mtu_expires);
 290                }
 291                if (!(dst_metric_locked(dst, RTAX_ADVMSS))) {
 292                        u32 mss = mtu - DN_MAX_NSP_DATA_HEADER;
 293                        u32 existing_mss = dst_metric_raw(dst, RTAX_ADVMSS);
 294                        if (!existing_mss || existing_mss > mss)
 295                                dst_metric_set(dst, RTAX_ADVMSS, mss);
 296                }
 297        }
 298}
 299
 300static void dn_dst_redirect(struct dst_entry *dst, struct sock *sk,
 301                            struct sk_buff *skb)
 302{
 303}
 304
 305/*
 306 * When a route has been marked obsolete. (e.g. routing cache flush)
 307 */
 308static struct dst_entry *dn_dst_check(struct dst_entry *dst, __u32 cookie)
 309{
 310        return NULL;
 311}
 312
 313static struct dst_entry *dn_dst_negative_advice(struct dst_entry *dst)
 314{
 315        dst_release(dst);
 316        return NULL;
 317}
 318
 319static void dn_dst_link_failure(struct sk_buff *skb)
 320{
 321}
 322
 323static inline int compare_keys(struct flowidn *fl1, struct flowidn *fl2)
 324{
 325        return ((fl1->daddr ^ fl2->daddr) |
 326                (fl1->saddr ^ fl2->saddr) |
 327                (fl1->flowidn_mark ^ fl2->flowidn_mark) |
 328                (fl1->flowidn_scope ^ fl2->flowidn_scope) |
 329                (fl1->flowidn_oif ^ fl2->flowidn_oif) |
 330                (fl1->flowidn_iif ^ fl2->flowidn_iif)) == 0;
 331}
 332
 333static int dn_insert_route(struct dn_route *rt, unsigned int hash, struct dn_route **rp)
 334{
 335        struct dn_route *rth;
 336        struct dn_route __rcu **rthp;
 337        unsigned long now = jiffies;
 338
 339        rthp = &dn_rt_hash_table[hash].chain;
 340
 341        spin_lock_bh(&dn_rt_hash_table[hash].lock);
 342        while ((rth = rcu_dereference_protected(*rthp,
 343                                                lockdep_is_held(&dn_rt_hash_table[hash].lock))) != NULL) {
 344                if (compare_keys(&rth->fld, &rt->fld)) {
 345                        /* Put it first */
 346                        *rthp = rth->dst.dn_next;
 347                        rcu_assign_pointer(rth->dst.dn_next,
 348                                           dn_rt_hash_table[hash].chain);
 349                        rcu_assign_pointer(dn_rt_hash_table[hash].chain, rth);
 350
 351                        dst_use(&rth->dst, now);
 352                        spin_unlock_bh(&dn_rt_hash_table[hash].lock);
 353
 354                        dnrt_drop(rt);
 355                        *rp = rth;
 356                        return 0;
 357                }
 358                rthp = &rth->dst.dn_next;
 359        }
 360
 361        rcu_assign_pointer(rt->dst.dn_next, dn_rt_hash_table[hash].chain);
 362        rcu_assign_pointer(dn_rt_hash_table[hash].chain, rt);
 363
 364        dst_use(&rt->dst, now);
 365        spin_unlock_bh(&dn_rt_hash_table[hash].lock);
 366        *rp = rt;
 367        return 0;
 368}
 369
 370static void dn_run_flush(unsigned long dummy)
 371{
 372        int i;
 373        struct dn_route *rt, *next;
 374
 375        for (i = 0; i < dn_rt_hash_mask; i++) {
 376                spin_lock_bh(&dn_rt_hash_table[i].lock);
 377
 378                if ((rt = xchg((struct dn_route **)&dn_rt_hash_table[i].chain, NULL)) == NULL)
 379                        goto nothing_to_declare;
 380
 381                for(; rt; rt = next) {
 382                        next = rcu_dereference_raw(rt->dst.dn_next);
 383                        RCU_INIT_POINTER(rt->dst.dn_next, NULL);
 384                        dst_free((struct dst_entry *)rt);
 385                }
 386
 387nothing_to_declare:
 388                spin_unlock_bh(&dn_rt_hash_table[i].lock);
 389        }
 390}
 391
 392static DEFINE_SPINLOCK(dn_rt_flush_lock);
 393
 394void dn_rt_cache_flush(int delay)
 395{
 396        unsigned long now = jiffies;
 397        int user_mode = !in_interrupt();
 398
 399        if (delay < 0)
 400                delay = dn_rt_min_delay;
 401
 402        spin_lock_bh(&dn_rt_flush_lock);
 403
 404        if (del_timer(&dn_rt_flush_timer) && delay > 0 && dn_rt_deadline) {
 405                long tmo = (long)(dn_rt_deadline - now);
 406
 407                if (user_mode && tmo < dn_rt_max_delay - dn_rt_min_delay)
 408                        tmo = 0;
 409
 410                if (delay > tmo)
 411                        delay = tmo;
 412        }
 413
 414        if (delay <= 0) {
 415                spin_unlock_bh(&dn_rt_flush_lock);
 416                dn_run_flush(0);
 417                return;
 418        }
 419
 420        if (dn_rt_deadline == 0)
 421                dn_rt_deadline = now + dn_rt_max_delay;
 422
 423        dn_rt_flush_timer.expires = now + delay;
 424        add_timer(&dn_rt_flush_timer);
 425        spin_unlock_bh(&dn_rt_flush_lock);
 426}
 427
 428/**
 429 * dn_return_short - Return a short packet to its sender
 430 * @skb: The packet to return
 431 *
 432 */
 433static int dn_return_short(struct sk_buff *skb)
 434{
 435        struct dn_skb_cb *cb;
 436        unsigned char *ptr;
 437        __le16 *src;
 438        __le16 *dst;
 439
 440        /* Add back headers */
 441        skb_push(skb, skb->data - skb_network_header(skb));
 442
 443        if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
 444                return NET_RX_DROP;
 445
 446        cb = DN_SKB_CB(skb);
 447        /* Skip packet length and point to flags */
 448        ptr = skb->data + 2;
 449        *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
 450
 451        dst = (__le16 *)ptr;
 452        ptr += 2;
 453        src = (__le16 *)ptr;
 454        ptr += 2;
 455        *ptr = 0; /* Zero hop count */
 456
 457        swap(*src, *dst);
 458
 459        skb->pkt_type = PACKET_OUTGOING;
 460        dn_rt_finish_output(skb, NULL, NULL);
 461        return NET_RX_SUCCESS;
 462}
 463
 464/**
 465 * dn_return_long - Return a long packet to its sender
 466 * @skb: The long format packet to return
 467 *
 468 */
 469static int dn_return_long(struct sk_buff *skb)
 470{
 471        struct dn_skb_cb *cb;
 472        unsigned char *ptr;
 473        unsigned char *src_addr, *dst_addr;
 474        unsigned char tmp[ETH_ALEN];
 475
 476        /* Add back all headers */
 477        skb_push(skb, skb->data - skb_network_header(skb));
 478
 479        if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
 480                return NET_RX_DROP;
 481
 482        cb = DN_SKB_CB(skb);
 483        /* Ignore packet length and point to flags */
 484        ptr = skb->data + 2;
 485
 486        /* Skip padding */
 487        if (*ptr & DN_RT_F_PF) {
 488                char padlen = (*ptr & ~DN_RT_F_PF);
 489                ptr += padlen;
 490        }
 491
 492        *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
 493        ptr += 2;
 494        dst_addr = ptr;
 495        ptr += 8;
 496        src_addr = ptr;
 497        ptr += 6;
 498        *ptr = 0; /* Zero hop count */
 499
 500        /* Swap source and destination */
 501        memcpy(tmp, src_addr, ETH_ALEN);
 502        memcpy(src_addr, dst_addr, ETH_ALEN);
 503        memcpy(dst_addr, tmp, ETH_ALEN);
 504
 505        skb->pkt_type = PACKET_OUTGOING;
 506        dn_rt_finish_output(skb, dst_addr, src_addr);
 507        return NET_RX_SUCCESS;
 508}
 509
 510/**
 511 * dn_route_rx_packet - Try and find a route for an incoming packet
 512 * @skb: The packet to find a route for
 513 *
 514 * Returns: result of input function if route is found, error code otherwise
 515 */
 516static int dn_route_rx_packet(struct sk_buff *skb)
 517{
 518        struct dn_skb_cb *cb;
 519        int err;
 520
 521        if ((err = dn_route_input(skb)) == 0)
 522                return dst_input(skb);
 523
 524        cb = DN_SKB_CB(skb);
 525        if (decnet_debug_level & 4) {
 526                char *devname = skb->dev ? skb->dev->name : "???";
 527
 528                printk(KERN_DEBUG
 529                        "DECnet: dn_route_rx_packet: rt_flags=0x%02x dev=%s len=%d src=0x%04hx dst=0x%04hx err=%d type=%d\n",
 530                        (int)cb->rt_flags, devname, skb->len,
 531                        le16_to_cpu(cb->src), le16_to_cpu(cb->dst),
 532                        err, skb->pkt_type);
 533        }
 534
 535        if ((skb->pkt_type == PACKET_HOST) && (cb->rt_flags & DN_RT_F_RQR)) {
 536                switch (cb->rt_flags & DN_RT_PKT_MSK) {
 537                case DN_RT_PKT_SHORT:
 538                        return dn_return_short(skb);
 539                case DN_RT_PKT_LONG:
 540                        return dn_return_long(skb);
 541                }
 542        }
 543
 544        kfree_skb(skb);
 545        return NET_RX_DROP;
 546}
 547
 548static int dn_route_rx_long(struct sk_buff *skb)
 549{
 550        struct dn_skb_cb *cb = DN_SKB_CB(skb);
 551        unsigned char *ptr = skb->data;
 552
 553        if (!pskb_may_pull(skb, 21)) /* 20 for long header, 1 for shortest nsp */
 554                goto drop_it;
 555
 556        skb_pull(skb, 20);
 557        skb_reset_transport_header(skb);
 558
 559        /* Destination info */
 560        ptr += 2;
 561        cb->dst = dn_eth2dn(ptr);
 562        if (memcmp(ptr, dn_hiord_addr, 4) != 0)
 563                goto drop_it;
 564        ptr += 6;
 565
 566
 567        /* Source info */
 568        ptr += 2;
 569        cb->src = dn_eth2dn(ptr);
 570        if (memcmp(ptr, dn_hiord_addr, 4) != 0)
 571                goto drop_it;
 572        ptr += 6;
 573        /* Other junk */
 574        ptr++;
 575        cb->hops = *ptr++; /* Visit Count */
 576
 577        return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING, 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, skb, skb->dev, NULL,
 605                       dn_route_rx_packet);
 606
 607drop_it:
 608        kfree_skb(skb);
 609        return NET_RX_DROP;
 610}
 611
 612static int dn_route_discard(struct sk_buff *skb)
 613{
 614        /*
 615         * I know we drop the packet here, but thats considered success in
 616         * this case
 617         */
 618        kfree_skb(skb);
 619        return NET_RX_SUCCESS;
 620}
 621
 622static int dn_route_ptp_hello(struct sk_buff *skb)
 623{
 624        dn_dev_hello(skb);
 625        dn_neigh_pointopoint_hello(skb);
 626        return NET_RX_SUCCESS;
 627}
 628
 629int dn_route_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
 630{
 631        struct dn_skb_cb *cb;
 632        unsigned char flags = 0;
 633        __u16 len = le16_to_cpu(*(__le16 *)skb->data);
 634        struct dn_dev *dn = rcu_dereference(dev->dn_ptr);
 635        unsigned char padlen = 0;
 636
 637        if (!net_eq(dev_net(dev), &init_net))
 638                goto dump_it;
 639
 640        if (dn == NULL)
 641                goto dump_it;
 642
 643        if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
 644                goto out;
 645
 646        if (!pskb_may_pull(skb, 3))
 647                goto dump_it;
 648
 649        skb_pull(skb, 2);
 650
 651        if (len > skb->len)
 652                goto dump_it;
 653
 654        skb_trim(skb, len);
 655
 656        flags = *skb->data;
 657
 658        cb = DN_SKB_CB(skb);
 659        cb->stamp = jiffies;
 660        cb->iif = dev->ifindex;
 661
 662        /*
 663         * If we have padding, remove it.
 664         */
 665        if (flags & DN_RT_F_PF) {
 666                padlen = flags & ~DN_RT_F_PF;
 667                if (!pskb_may_pull(skb, padlen + 1))
 668                        goto dump_it;
 669                skb_pull(skb, padlen);
 670                flags = *skb->data;
 671        }
 672
 673        skb_reset_network_header(skb);
 674
 675        /*
 676         * Weed out future version DECnet
 677         */
 678        if (flags & DN_RT_F_VER)
 679                goto dump_it;
 680
 681        cb->rt_flags = flags;
 682
 683        if (decnet_debug_level & 1)
 684                printk(KERN_DEBUG
 685                        "dn_route_rcv: got 0x%02x from %s [%d %d %d]\n",
 686                        (int)flags, (dev) ? dev->name : "???", len, skb->len,
 687                        padlen);
 688
 689        if (flags & DN_RT_PKT_CNTL) {
 690                if (unlikely(skb_linearize(skb)))
 691                        goto dump_it;
 692
 693                switch (flags & DN_RT_CNTL_MSK) {
 694                case DN_RT_PKT_INIT:
 695                        dn_dev_init_pkt(skb);
 696                        break;
 697                case DN_RT_PKT_VERI:
 698                        dn_dev_veri_pkt(skb);
 699                        break;
 700                }
 701
 702                if (dn->parms.state != DN_DEV_S_RU)
 703                        goto dump_it;
 704
 705                switch (flags & DN_RT_CNTL_MSK) {
 706                case DN_RT_PKT_HELO:
 707                        return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
 708                                       skb, skb->dev, NULL,
 709                                       dn_route_ptp_hello);
 710
 711                case DN_RT_PKT_L1RT:
 712                case DN_RT_PKT_L2RT:
 713                        return NF_HOOK(NFPROTO_DECNET, NF_DN_ROUTE,
 714                                       skb, skb->dev, NULL,
 715                                       dn_route_discard);
 716                case DN_RT_PKT_ERTH:
 717                        return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
 718                                       skb, skb->dev, NULL,
 719                                       dn_neigh_router_hello);
 720
 721                case DN_RT_PKT_EEDH:
 722                        return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
 723                                       skb, skb->dev, NULL,
 724                                       dn_neigh_endnode_hello);
 725                }
 726        } else {
 727                if (dn->parms.state != DN_DEV_S_RU)
 728                        goto dump_it;
 729
 730                skb_pull(skb, 1); /* Pull flags */
 731
 732                switch (flags & DN_RT_PKT_MSK) {
 733                case DN_RT_PKT_LONG:
 734                        return dn_route_rx_long(skb);
 735                case DN_RT_PKT_SHORT:
 736                        return dn_route_rx_short(skb);
 737                }
 738        }
 739
 740dump_it:
 741        kfree_skb(skb);
 742out:
 743        return NET_RX_DROP;
 744}
 745
 746static int dn_to_neigh_output(struct sk_buff *skb)
 747{
 748        struct dst_entry *dst = skb_dst(skb);
 749        struct dn_route *rt = (struct dn_route *) dst;
 750        struct neighbour *n = rt->n;
 751
 752        return n->output(n, skb);
 753}
 754
 755static int dn_output(struct sock *sk, struct sk_buff *skb)
 756{
 757        struct dst_entry *dst = skb_dst(skb);
 758        struct dn_route *rt = (struct dn_route *)dst;
 759        struct net_device *dev = dst->dev;
 760        struct dn_skb_cb *cb = DN_SKB_CB(skb);
 761
 762        int err = -EINVAL;
 763
 764        if (rt->n == NULL)
 765                goto error;
 766
 767        skb->dev = dev;
 768
 769        cb->src = rt->rt_saddr;
 770        cb->dst = rt->rt_daddr;
 771
 772        /*
 773         * Always set the Intra-Ethernet bit on all outgoing packets
 774         * originated on this node. Only valid flag from upper layers
 775         * is return-to-sender-requested. Set hop count to 0 too.
 776         */
 777        cb->rt_flags &= ~DN_RT_F_RQR;
 778        cb->rt_flags |= DN_RT_F_IE;
 779        cb->hops = 0;
 780
 781        return NF_HOOK(NFPROTO_DECNET, NF_DN_LOCAL_OUT, skb, NULL, dev,
 782                       dn_to_neigh_output);
 783
 784error:
 785        net_dbg_ratelimited("dn_output: This should not happen\n");
 786
 787        kfree_skb(skb);
 788
 789        return err;
 790}
 791
 792static int dn_forward(struct sk_buff *skb)
 793{
 794        struct dn_skb_cb *cb = DN_SKB_CB(skb);
 795        struct dst_entry *dst = skb_dst(skb);
 796        struct dn_dev *dn_db = rcu_dereference(dst->dev->dn_ptr);
 797        struct dn_route *rt;
 798        int header_len;
 799#ifdef CONFIG_NETFILTER
 800        struct net_device *dev = skb->dev;
 801#endif
 802
 803        if (skb->pkt_type != PACKET_HOST)
 804                goto drop;
 805
 806        /* Ensure that we have enough space for headers */
 807        rt = (struct dn_route *)skb_dst(skb);
 808        header_len = dn_db->use_long ? 21 : 6;
 809        if (skb_cow(skb, LL_RESERVED_SPACE(rt->dst.dev)+header_len))
 810                goto drop;
 811
 812        /*
 813         * Hop count exceeded.
 814         */
 815        if (++cb->hops > 30)
 816                goto drop;
 817
 818        skb->dev = rt->dst.dev;
 819
 820        /*
 821         * If packet goes out same interface it came in on, then set
 822         * the Intra-Ethernet bit. This has no effect for short
 823         * packets, so we don't need to test for them here.
 824         */
 825        cb->rt_flags &= ~DN_RT_F_IE;
 826        if (rt->rt_flags & RTCF_DOREDIRECT)
 827                cb->rt_flags |= DN_RT_F_IE;
 828
 829        return NF_HOOK(NFPROTO_DECNET, NF_DN_FORWARD, skb, dev, skb->dev,
 830                       dn_to_neigh_output);
 831
 832drop:
 833        kfree_skb(skb);
 834        return NET_RX_DROP;
 835}
 836
 837/*
 838 * Used to catch bugs. This should never normally get
 839 * called.
 840 */
 841static int dn_rt_bug_sk(struct sock *sk, struct sk_buff *skb)
 842{
 843        struct dn_skb_cb *cb = DN_SKB_CB(skb);
 844
 845        net_dbg_ratelimited("dn_rt_bug: skb from:%04x to:%04x\n",
 846                            le16_to_cpu(cb->src), le16_to_cpu(cb->dst));
 847
 848        kfree_skb(skb);
 849
 850        return NET_RX_DROP;
 851}
 852
 853static int dn_rt_bug(struct sk_buff *skb)
 854{
 855        struct dn_skb_cb *cb = DN_SKB_CB(skb);
 856
 857        net_dbg_ratelimited("dn_rt_bug: skb from:%04x to:%04x\n",
 858                            le16_to_cpu(cb->src), le16_to_cpu(cb->dst));
 859
 860        kfree_skb(skb);
 861
 862        return NET_RX_DROP;
 863}
 864
 865static unsigned int dn_dst_default_advmss(const struct dst_entry *dst)
 866{
 867        return dn_mss_from_pmtu(dst->dev, dst_mtu(dst));
 868}
 869
 870static unsigned int dn_dst_mtu(const struct dst_entry *dst)
 871{
 872        unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
 873
 874        return mtu ? : dst->dev->mtu;
 875}
 876
 877static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst,
 878                                             struct sk_buff *skb,
 879                                             const void *daddr)
 880{
 881        return __neigh_lookup_errno(&dn_neigh_table, daddr, dst->dev);
 882}
 883
 884static int dn_rt_set_next_hop(struct dn_route *rt, struct dn_fib_res *res)
 885{
 886        struct dn_fib_info *fi = res->fi;
 887        struct net_device *dev = rt->dst.dev;
 888        unsigned int mss_metric;
 889        struct neighbour *n;
 890
 891        if (fi) {
 892                if (DN_FIB_RES_GW(*res) &&
 893                    DN_FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
 894                        rt->rt_gateway = DN_FIB_RES_GW(*res);
 895                dst_init_metrics(&rt->dst, fi->fib_metrics, true);
 896        }
 897        rt->rt_type = res->type;
 898
 899        if (dev != NULL && rt->n == NULL) {
 900                n = __neigh_lookup_errno(&dn_neigh_table, &rt->rt_gateway, dev);
 901                if (IS_ERR(n))
 902                        return PTR_ERR(n);
 903                rt->n = n;
 904        }
 905
 906        if (dst_metric(&rt->dst, RTAX_MTU) > rt->dst.dev->mtu)
 907                dst_metric_set(&rt->dst, RTAX_MTU, rt->dst.dev->mtu);
 908        mss_metric = dst_metric_raw(&rt->dst, RTAX_ADVMSS);
 909        if (mss_metric) {
 910                unsigned int mss = dn_mss_from_pmtu(dev, dst_mtu(&rt->dst));
 911                if (mss_metric > mss)
 912                        dst_metric_set(&rt->dst, RTAX_ADVMSS, mss);
 913        }
 914        return 0;
 915}
 916
 917static inline int dn_match_addr(__le16 addr1, __le16 addr2)
 918{
 919        __u16 tmp = le16_to_cpu(addr1) ^ le16_to_cpu(addr2);
 920        int match = 16;
 921        while(tmp) {
 922                tmp >>= 1;
 923                match--;
 924        }
 925        return match;
 926}
 927
 928static __le16 dnet_select_source(const struct net_device *dev, __le16 daddr, int scope)
 929{
 930        __le16 saddr = 0;
 931        struct dn_dev *dn_db;
 932        struct dn_ifaddr *ifa;
 933        int best_match = 0;
 934        int ret;
 935
 936        rcu_read_lock();
 937        dn_db = rcu_dereference(dev->dn_ptr);
 938        for (ifa = rcu_dereference(dn_db->ifa_list);
 939             ifa != NULL;
 940             ifa = rcu_dereference(ifa->ifa_next)) {
 941                if (ifa->ifa_scope > scope)
 942                        continue;
 943                if (!daddr) {
 944                        saddr = ifa->ifa_local;
 945                        break;
 946                }
 947                ret = dn_match_addr(daddr, ifa->ifa_local);
 948                if (ret > best_match)
 949                        saddr = ifa->ifa_local;
 950                if (best_match == 0)
 951                        saddr = ifa->ifa_local;
 952        }
 953        rcu_read_unlock();
 954
 955        return saddr;
 956}
 957
 958static inline __le16 __dn_fib_res_prefsrc(struct dn_fib_res *res)
 959{
 960        return dnet_select_source(DN_FIB_RES_DEV(*res), DN_FIB_RES_GW(*res), res->scope);
 961}
 962
 963static inline __le16 dn_fib_rules_map_destination(__le16 daddr, struct dn_fib_res *res)
 964{
 965        __le16 mask = dnet_make_mask(res->prefixlen);
 966        return (daddr&~mask)|res->fi->fib_nh->nh_gw;
 967}
 968
 969static int dn_route_output_slow(struct dst_entry **pprt, const struct flowidn *oldflp, int try_hard)
 970{
 971        struct flowidn fld = {
 972                .daddr = oldflp->daddr,
 973                .saddr = oldflp->saddr,
 974                .flowidn_scope = RT_SCOPE_UNIVERSE,
 975                .flowidn_mark = oldflp->flowidn_mark,
 976                .flowidn_iif = LOOPBACK_IFINDEX,
 977                .flowidn_oif = oldflp->flowidn_oif,
 978        };
 979        struct dn_route *rt = NULL;
 980        struct net_device *dev_out = NULL, *dev;
 981        struct neighbour *neigh = NULL;
 982        unsigned int hash;
 983        unsigned int flags = 0;
 984        struct dn_fib_res res = { .fi = NULL, .type = RTN_UNICAST };
 985        int err;
 986        int free_res = 0;
 987        __le16 gateway = 0;
 988
 989        if (decnet_debug_level & 16)
 990                printk(KERN_DEBUG
 991                       "dn_route_output_slow: dst=%04x src=%04x mark=%d"
 992                       " iif=%d oif=%d\n", le16_to_cpu(oldflp->daddr),
 993                       le16_to_cpu(oldflp->saddr),
 994                       oldflp->flowidn_mark, LOOPBACK_IFINDEX,
 995                       oldflp->flowidn_oif);
 996
 997        /* If we have an output interface, verify its a DECnet device */
 998        if (oldflp->flowidn_oif) {
 999                dev_out = dev_get_by_index(&init_net, oldflp->flowidn_oif);
1000                err = -ENODEV;
1001                if (dev_out && dev_out->dn_ptr == NULL) {
1002                        dev_put(dev_out);
1003                        dev_out = NULL;
1004                }
1005                if (dev_out == NULL)
1006                        goto out;
1007        }
1008
1009        /* If we have a source address, verify that its a local address */
1010        if (oldflp->saddr) {
1011                err = -EADDRNOTAVAIL;
1012
1013                if (dev_out) {
1014                        if (dn_dev_islocal(dev_out, oldflp->saddr))
1015                                goto source_ok;
1016                        dev_put(dev_out);
1017                        goto out;
1018                }
1019                rcu_read_lock();
1020                for_each_netdev_rcu(&init_net, dev) {
1021                        if (!dev->dn_ptr)
1022                                continue;
1023                        if (!dn_dev_islocal(dev, oldflp->saddr))
1024                                continue;
1025                        if ((dev->flags & IFF_LOOPBACK) &&
1026                            oldflp->daddr &&
1027                            !dn_dev_islocal(dev, oldflp->daddr))
1028                                continue;
1029
1030                        dev_out = dev;
1031                        break;
1032                }
1033                rcu_read_unlock();
1034                if (dev_out == NULL)
1035                        goto out;
1036                dev_hold(dev_out);
1037source_ok:
1038                ;
1039        }
1040
1041        /* No destination? Assume its local */
1042        if (!fld.daddr) {
1043                fld.daddr = fld.saddr;
1044
1045                err = -EADDRNOTAVAIL;
1046                if (dev_out)
1047                        dev_put(dev_out);
1048                dev_out = init_net.loopback_dev;
1049                dev_hold(dev_out);
1050                if (!fld.daddr) {
1051                        fld.daddr =
1052                        fld.saddr = dnet_select_source(dev_out, 0,
1053                                                       RT_SCOPE_HOST);
1054                        if (!fld.daddr)
1055                                goto out;
1056                }
1057                fld.flowidn_oif = LOOPBACK_IFINDEX;
1058                res.type = RTN_LOCAL;
1059                goto make_route;
1060        }
1061
1062        if (decnet_debug_level & 16)
1063                printk(KERN_DEBUG
1064                       "dn_route_output_slow: initial checks complete."
1065                       " dst=%o4x src=%04x oif=%d try_hard=%d\n",
1066                       le16_to_cpu(fld.daddr), le16_to_cpu(fld.saddr),
1067                       fld.flowidn_oif, try_hard);
1068
1069        /*
1070         * N.B. If the kernel is compiled without router support then
1071         * dn_fib_lookup() will evaluate to non-zero so this if () block
1072         * will always be executed.
1073         */
1074        err = -ESRCH;
1075        if (try_hard || (err = dn_fib_lookup(&fld, &res)) != 0) {
1076                struct dn_dev *dn_db;
1077                if (err != -ESRCH)
1078                        goto out;
1079                /*
1080                 * Here the fallback is basically the standard algorithm for
1081                 * routing in endnodes which is described in the DECnet routing
1082                 * docs
1083                 *
1084                 * If we are not trying hard, look in neighbour cache.
1085                 * The result is tested to ensure that if a specific output
1086                 * device/source address was requested, then we honour that
1087                 * here
1088                 */
1089                if (!try_hard) {
1090                        neigh = neigh_lookup_nodev(&dn_neigh_table, &init_net, &fld.daddr);
1091                        if (neigh) {
1092                                if ((oldflp->flowidn_oif &&
1093                                    (neigh->dev->ifindex != oldflp->flowidn_oif)) ||
1094                                    (oldflp->saddr &&
1095                                    (!dn_dev_islocal(neigh->dev,
1096                                                     oldflp->saddr)))) {
1097                                        neigh_release(neigh);
1098                                        neigh = NULL;
1099                                } else {
1100                                        if (dev_out)
1101                                                dev_put(dev_out);
1102                                        if (dn_dev_islocal(neigh->dev, fld.daddr)) {
1103                                                dev_out = init_net.loopback_dev;
1104                                                res.type = RTN_LOCAL;
1105                                        } else {
1106                                                dev_out = neigh->dev;
1107                                        }
1108                                        dev_hold(dev_out);
1109                                        goto select_source;
1110                                }
1111                        }
1112                }
1113
1114                /* Not there? Perhaps its a local address */
1115                if (dev_out == NULL)
1116                        dev_out = dn_dev_get_default();
1117                err = -ENODEV;
1118                if (dev_out == NULL)
1119                        goto out;
1120                dn_db = rcu_dereference_raw(dev_out->dn_ptr);
1121                /* Possible improvement - check all devices for local addr */
1122                if (dn_dev_islocal(dev_out, fld.daddr)) {
1123                        dev_put(dev_out);
1124                        dev_out = init_net.loopback_dev;
1125                        dev_hold(dev_out);
1126                        res.type = RTN_LOCAL;
1127                        goto select_source;
1128                }
1129                /* Not local either.... try sending it to the default router */
1130                neigh = neigh_clone(dn_db->router);
1131                BUG_ON(neigh && neigh->dev != dev_out);
1132
1133                /* Ok then, we assume its directly connected and move on */
1134select_source:
1135                if (neigh)
1136                        gateway = ((struct dn_neigh *)neigh)->addr;
1137                if (gateway == 0)
1138                        gateway = fld.daddr;
1139                if (fld.saddr == 0) {
1140                        fld.saddr = dnet_select_source(dev_out, gateway,
1141                                                       res.type == RTN_LOCAL ?
1142                                                       RT_SCOPE_HOST :
1143                                                       RT_SCOPE_LINK);
1144                        if (fld.saddr == 0 && res.type != RTN_LOCAL)
1145                                goto e_addr;
1146                }
1147                fld.flowidn_oif = dev_out->ifindex;
1148                goto make_route;
1149        }
1150        free_res = 1;
1151
1152        if (res.type == RTN_NAT)
1153                goto e_inval;
1154
1155        if (res.type == RTN_LOCAL) {
1156                if (!fld.saddr)
1157                        fld.saddr = fld.daddr;
1158                if (dev_out)
1159                        dev_put(dev_out);
1160                dev_out = init_net.loopback_dev;
1161                dev_hold(dev_out);
1162                fld.flowidn_oif = dev_out->ifindex;
1163                if (res.fi)
1164                        dn_fib_info_put(res.fi);
1165                res.fi = NULL;
1166                goto make_route;
1167        }
1168
1169        if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1170                dn_fib_select_multipath(&fld, &res);
1171
1172        /*
1173         * We could add some logic to deal with default routes here and
1174         * get rid of some of the special casing above.
1175         */
1176
1177        if (!fld.saddr)
1178                fld.saddr = DN_FIB_RES_PREFSRC(res);
1179
1180        if (dev_out)
1181                dev_put(dev_out);
1182        dev_out = DN_FIB_RES_DEV(res);
1183        dev_hold(dev_out);
1184        fld.flowidn_oif = dev_out->ifindex;
1185        gateway = DN_FIB_RES_GW(res);
1186
1187make_route:
1188        if (dev_out->flags & IFF_LOOPBACK)
1189                flags |= RTCF_LOCAL;
1190
1191        rt = dst_alloc(&dn_dst_ops, dev_out, 1, DST_OBSOLETE_NONE, DST_HOST);
1192        if (rt == NULL)
1193                goto e_nobufs;
1194
1195        memset(&rt->fld, 0, sizeof(rt->fld));
1196        rt->fld.saddr        = oldflp->saddr;
1197        rt->fld.daddr        = oldflp->daddr;
1198        rt->fld.flowidn_oif  = oldflp->flowidn_oif;
1199        rt->fld.flowidn_iif  = 0;
1200        rt->fld.flowidn_mark = oldflp->flowidn_mark;
1201
1202        rt->rt_saddr      = fld.saddr;
1203        rt->rt_daddr      = fld.daddr;
1204        rt->rt_gateway    = gateway ? gateway : fld.daddr;
1205        rt->rt_local_src  = fld.saddr;
1206
1207        rt->rt_dst_map    = fld.daddr;
1208        rt->rt_src_map    = fld.saddr;
1209
1210        rt->n = neigh;
1211        neigh = NULL;
1212
1213        rt->dst.lastuse = jiffies;
1214        rt->dst.output  = dn_output;
1215        rt->dst.input   = dn_rt_bug;
1216        rt->rt_flags      = flags;
1217        if (flags & RTCF_LOCAL)
1218                rt->dst.input = dn_nsp_rx;
1219
1220        err = dn_rt_set_next_hop(rt, &res);
1221        if (err)
1222                goto e_neighbour;
1223
1224        hash = dn_hash(rt->fld.saddr, rt->fld.daddr);
1225        dn_insert_route(rt, hash, (struct dn_route **)pprt);
1226
1227done:
1228        if (neigh)
1229                neigh_release(neigh);
1230        if (free_res)
1231                dn_fib_res_put(&res);
1232        if (dev_out)
1233                dev_put(dev_out);
1234out:
1235        return err;
1236
1237e_addr:
1238        err = -EADDRNOTAVAIL;
1239        goto done;
1240e_inval:
1241        err = -EINVAL;
1242        goto done;
1243e_nobufs:
1244        err = -ENOBUFS;
1245        goto done;
1246e_neighbour:
1247        dst_free(&rt->dst);
1248        goto e_nobufs;
1249}
1250
1251
1252/*
1253 * N.B. The flags may be moved into the flowi at some future stage.
1254 */
1255static int __dn_route_output_key(struct dst_entry **pprt, const struct flowidn *flp, int flags)
1256{
1257        unsigned int hash = dn_hash(flp->saddr, flp->daddr);
1258        struct dn_route *rt = NULL;
1259
1260        if (!(flags & MSG_TRYHARD)) {
1261                rcu_read_lock_bh();
1262                for (rt = rcu_dereference_bh(dn_rt_hash_table[hash].chain); rt;
1263                        rt = rcu_dereference_bh(rt->dst.dn_next)) {
1264                        if ((flp->daddr == rt->fld.daddr) &&
1265                            (flp->saddr == rt->fld.saddr) &&
1266                            (flp->flowidn_mark == rt->fld.flowidn_mark) &&
1267                            dn_is_output_route(rt) &&
1268                            (rt->fld.flowidn_oif == flp->flowidn_oif)) {
1269                                dst_use(&rt->dst, jiffies);
1270                                rcu_read_unlock_bh();
1271                                *pprt = &rt->dst;
1272                                return 0;
1273                        }
1274                }
1275                rcu_read_unlock_bh();
1276        }
1277
1278        return dn_route_output_slow(pprt, flp, flags);
1279}
1280
1281static int dn_route_output_key(struct dst_entry **pprt, struct flowidn *flp, int flags)
1282{
1283        int err;
1284
1285        err = __dn_route_output_key(pprt, flp, flags);
1286        if (err == 0 && flp->flowidn_proto) {
1287                *pprt = xfrm_lookup(&init_net, *pprt,
1288                                    flowidn_to_flowi(flp), NULL, 0);
1289                if (IS_ERR(*pprt)) {
1290                        err = PTR_ERR(*pprt);
1291                        *pprt = NULL;
1292                }
1293        }
1294        return err;
1295}
1296
1297int dn_route_output_sock(struct dst_entry __rcu **pprt, struct flowidn *fl, struct sock *sk, int flags)
1298{
1299        int err;
1300
1301        err = __dn_route_output_key(pprt, fl, flags & MSG_TRYHARD);
1302        if (err == 0 && fl->flowidn_proto) {
1303                *pprt = xfrm_lookup(&init_net, *pprt,
1304                                    flowidn_to_flowi(fl), sk, 0);
1305                if (IS_ERR(*pprt)) {
1306                        err = PTR_ERR(*pprt);
1307                        *pprt = NULL;
1308                }
1309        }
1310        return err;
1311}
1312
1313static int dn_route_input_slow(struct sk_buff *skb)
1314{
1315        struct dn_route *rt = NULL;
1316        struct dn_skb_cb *cb = DN_SKB_CB(skb);
1317        struct net_device *in_dev = skb->dev;
1318        struct net_device *out_dev = NULL;
1319        struct dn_dev *dn_db;
1320        struct neighbour *neigh = NULL;
1321        unsigned int hash;
1322        int flags = 0;
1323        __le16 gateway = 0;
1324        __le16 local_src = 0;
1325        struct flowidn fld = {
1326                .daddr = cb->dst,
1327                .saddr = cb->src,
1328                .flowidn_scope = RT_SCOPE_UNIVERSE,
1329                .flowidn_mark = skb->mark,
1330                .flowidn_iif = skb->dev->ifindex,
1331        };
1332        struct dn_fib_res res = { .fi = NULL, .type = RTN_UNREACHABLE };
1333        int err = -EINVAL;
1334        int free_res = 0;
1335
1336        dev_hold(in_dev);
1337
1338        if ((dn_db = rcu_dereference(in_dev->dn_ptr)) == NULL)
1339                goto out;
1340
1341        /* Zero source addresses are not allowed */
1342        if (fld.saddr == 0)
1343                goto out;
1344
1345        /*
1346         * In this case we've just received a packet from a source
1347         * outside ourselves pretending to come from us. We don't
1348         * allow it any further to prevent routing loops, spoofing and
1349         * other nasties. Loopback packets already have the dst attached
1350         * so this only affects packets which have originated elsewhere.
1351         */
1352        err  = -ENOTUNIQ;
1353        if (dn_dev_islocal(in_dev, cb->src))
1354                goto out;
1355
1356        err = dn_fib_lookup(&fld, &res);
1357        if (err) {
1358                if (err != -ESRCH)
1359                        goto out;
1360                /*
1361                 * Is the destination us ?
1362                 */
1363                if (!dn_dev_islocal(in_dev, cb->dst))
1364                        goto e_inval;
1365
1366                res.type = RTN_LOCAL;
1367        } else {
1368                __le16 src_map = fld.saddr;
1369                free_res = 1;
1370
1371                out_dev = DN_FIB_RES_DEV(res);
1372                if (out_dev == NULL) {
1373                        net_crit_ratelimited("Bug in dn_route_input_slow() No output device\n");
1374                        goto e_inval;
1375                }
1376                dev_hold(out_dev);
1377
1378                if (res.r)
1379                        src_map = fld.saddr; /* no NAT support for now */
1380
1381                gateway = DN_FIB_RES_GW(res);
1382                if (res.type == RTN_NAT) {
1383                        fld.daddr = dn_fib_rules_map_destination(fld.daddr, &res);
1384                        dn_fib_res_put(&res);
1385                        free_res = 0;
1386                        if (dn_fib_lookup(&fld, &res))
1387                                goto e_inval;
1388                        free_res = 1;
1389                        if (res.type != RTN_UNICAST)
1390                                goto e_inval;
1391                        flags |= RTCF_DNAT;
1392                        gateway = fld.daddr;
1393                }
1394                fld.saddr = src_map;
1395        }
1396
1397        switch(res.type) {
1398        case RTN_UNICAST:
1399                /*
1400                 * Forwarding check here, we only check for forwarding
1401                 * being turned off, if you want to only forward intra
1402                 * area, its up to you to set the routing tables up
1403                 * correctly.
1404                 */
1405                if (dn_db->parms.forwarding == 0)
1406                        goto e_inval;
1407
1408                if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1409                        dn_fib_select_multipath(&fld, &res);
1410
1411                /*
1412                 * Check for out_dev == in_dev. We use the RTCF_DOREDIRECT
1413                 * flag as a hint to set the intra-ethernet bit when
1414                 * forwarding. If we've got NAT in operation, we don't do
1415                 * this optimisation.
1416                 */
1417                if (out_dev == in_dev && !(flags & RTCF_NAT))
1418                        flags |= RTCF_DOREDIRECT;
1419
1420                local_src = DN_FIB_RES_PREFSRC(res);
1421
1422        case RTN_BLACKHOLE:
1423        case RTN_UNREACHABLE:
1424                break;
1425        case RTN_LOCAL:
1426                flags |= RTCF_LOCAL;
1427                fld.saddr = cb->dst;
1428                fld.daddr = cb->src;
1429
1430                /* Routing tables gave us a gateway */
1431                if (gateway)
1432                        goto make_route;
1433
1434                /* Packet was intra-ethernet, so we know its on-link */
1435                if (cb->rt_flags & DN_RT_F_IE) {
1436                        gateway = cb->src;
1437                        goto make_route;
1438                }
1439
1440                /* Use the default router if there is one */
1441                neigh = neigh_clone(dn_db->router);
1442                if (neigh) {
1443                        gateway = ((struct dn_neigh *)neigh)->addr;
1444                        goto make_route;
1445                }
1446
1447                /* Close eyes and pray */
1448                gateway = cb->src;
1449                goto make_route;
1450        default:
1451                goto e_inval;
1452        }
1453
1454make_route:
1455        rt = dst_alloc(&dn_dst_ops, out_dev, 0, DST_OBSOLETE_NONE, DST_HOST);
1456        if (rt == NULL)
1457                goto e_nobufs;
1458
1459        memset(&rt->fld, 0, sizeof(rt->fld));
1460        rt->rt_saddr      = fld.saddr;
1461        rt->rt_daddr      = fld.daddr;
1462        rt->rt_gateway    = fld.daddr;
1463        if (gateway)
1464                rt->rt_gateway = gateway;
1465        rt->rt_local_src  = local_src ? local_src : rt->rt_saddr;
1466
1467        rt->rt_dst_map    = fld.daddr;
1468        rt->rt_src_map    = fld.saddr;
1469
1470        rt->fld.saddr        = cb->src;
1471        rt->fld.daddr        = cb->dst;
1472        rt->fld.flowidn_oif  = 0;
1473        rt->fld.flowidn_iif  = in_dev->ifindex;
1474        rt->fld.flowidn_mark = fld.flowidn_mark;
1475
1476        rt->n = neigh;
1477        rt->dst.lastuse = jiffies;
1478        rt->dst.output = dn_rt_bug_sk;
1479        switch (res.type) {
1480        case RTN_UNICAST:
1481                rt->dst.input = dn_forward;
1482                break;
1483        case RTN_LOCAL:
1484                rt->dst.output = dn_output;
1485                rt->dst.input = dn_nsp_rx;
1486                rt->dst.dev = in_dev;
1487                flags |= RTCF_LOCAL;
1488                break;
1489        default:
1490        case RTN_UNREACHABLE:
1491        case RTN_BLACKHOLE:
1492                rt->dst.input = dst_discard;
1493        }
1494        rt->rt_flags = flags;
1495
1496        err = dn_rt_set_next_hop(rt, &res);
1497        if (err)
1498                goto e_neighbour;
1499
1500        hash = dn_hash(rt->fld.saddr, rt->fld.daddr);
1501        dn_insert_route(rt, hash, &rt);
1502        skb_dst_set(skb, &rt->dst);
1503
1504done:
1505        if (neigh)
1506                neigh_release(neigh);
1507        if (free_res)
1508                dn_fib_res_put(&res);
1509        dev_put(in_dev);
1510        if (out_dev)
1511                dev_put(out_dev);
1512out:
1513        return err;
1514
1515e_inval:
1516        err = -EINVAL;
1517        goto done;
1518
1519e_nobufs:
1520        err = -ENOBUFS;
1521        goto done;
1522
1523e_neighbour:
1524        dst_free(&rt->dst);
1525        goto done;
1526}
1527
1528static int dn_route_input(struct sk_buff *skb)
1529{
1530        struct dn_route *rt;
1531        struct dn_skb_cb *cb = DN_SKB_CB(skb);
1532        unsigned int hash = dn_hash(cb->src, cb->dst);
1533
1534        if (skb_dst(skb))
1535                return 0;
1536
1537        rcu_read_lock();
1538        for(rt = rcu_dereference(dn_rt_hash_table[hash].chain); rt != NULL;
1539            rt = rcu_dereference(rt->dst.dn_next)) {
1540                if ((rt->fld.saddr == cb->src) &&
1541                    (rt->fld.daddr == cb->dst) &&
1542                    (rt->fld.flowidn_oif == 0) &&
1543                    (rt->fld.flowidn_mark == skb->mark) &&
1544                    (rt->fld.flowidn_iif == cb->iif)) {
1545                        dst_use(&rt->dst, jiffies);
1546                        rcu_read_unlock();
1547                        skb_dst_set(skb, (struct dst_entry *)rt);
1548                        return 0;
1549                }
1550        }
1551        rcu_read_unlock();
1552
1553        return dn_route_input_slow(skb);
1554}
1555
1556static int dn_rt_fill_info(struct sk_buff *skb, u32 portid, u32 seq,
1557                           int event, int nowait, unsigned int flags)
1558{
1559        struct dn_route *rt = (struct dn_route *)skb_dst(skb);
1560        struct rtmsg *r;
1561        struct nlmsghdr *nlh;
1562        long expires;
1563
1564        nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
1565        if (!nlh)
1566                return -EMSGSIZE;
1567
1568        r = nlmsg_data(nlh);
1569        r->rtm_family = AF_DECnet;
1570        r->rtm_dst_len = 16;
1571        r->rtm_src_len = 0;
1572        r->rtm_tos = 0;
1573        r->rtm_table = RT_TABLE_MAIN;
1574        r->rtm_type = rt->rt_type;
1575        r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
1576        r->rtm_scope = RT_SCOPE_UNIVERSE;
1577        r->rtm_protocol = RTPROT_UNSPEC;
1578
1579        if (rt->rt_flags & RTCF_NOTIFY)
1580                r->rtm_flags |= RTM_F_NOTIFY;
1581
1582        if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN) < 0 ||
1583            nla_put_le16(skb, RTA_DST, rt->rt_daddr) < 0)
1584                goto errout;
1585
1586        if (rt->fld.saddr) {
1587                r->rtm_src_len = 16;
1588                if (nla_put_le16(skb, RTA_SRC, rt->fld.saddr) < 0)
1589                        goto errout;
1590        }
1591        if (rt->dst.dev &&
1592            nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex) < 0)
1593                goto errout;
1594
1595        /*
1596         * Note to self - change this if input routes reverse direction when
1597         * they deal only with inputs and not with replies like they do
1598         * currently.
1599         */
1600        if (nla_put_le16(skb, RTA_PREFSRC, rt->rt_local_src) < 0)
1601                goto errout;
1602
1603        if (rt->rt_daddr != rt->rt_gateway &&
1604            nla_put_le16(skb, RTA_GATEWAY, rt->rt_gateway) < 0)
1605                goto errout;
1606
1607        if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
1608                goto errout;
1609
1610        expires = rt->dst.expires ? rt->dst.expires - jiffies : 0;
1611        if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires,
1612                               rt->dst.error) < 0)
1613                goto errout;
1614
1615        if (dn_is_input_route(rt) &&
1616            nla_put_u32(skb, RTA_IIF, rt->fld.flowidn_iif) < 0)
1617                goto errout;
1618
1619        nlmsg_end(skb, nlh);
1620        return 0;
1621
1622errout:
1623        nlmsg_cancel(skb, nlh);
1624        return -EMSGSIZE;
1625}
1626
1627const struct nla_policy rtm_dn_policy[RTA_MAX + 1] = {
1628        [RTA_DST]               = { .type = NLA_U16 },
1629        [RTA_SRC]               = { .type = NLA_U16 },
1630        [RTA_IIF]               = { .type = NLA_U32 },
1631        [RTA_OIF]               = { .type = NLA_U32 },
1632        [RTA_GATEWAY]           = { .type = NLA_U16 },
1633        [RTA_PRIORITY]          = { .type = NLA_U32 },
1634        [RTA_PREFSRC]           = { .type = NLA_U16 },
1635        [RTA_METRICS]           = { .type = NLA_NESTED },
1636        [RTA_MULTIPATH]         = { .type = NLA_NESTED },
1637        [RTA_TABLE]             = { .type = NLA_U32 },
1638        [RTA_MARK]              = { .type = NLA_U32 },
1639};
1640
1641/*
1642 * This is called by both endnodes and routers now.
1643 */
1644static int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
1645{
1646        struct net *net = sock_net(in_skb->sk);
1647        struct rtmsg *rtm = nlmsg_data(nlh);
1648        struct dn_route *rt = NULL;
1649        struct dn_skb_cb *cb;
1650        int err;
1651        struct sk_buff *skb;
1652        struct flowidn fld;
1653        struct nlattr *tb[RTA_MAX+1];
1654
1655        if (!net_eq(net, &init_net))
1656                return -EINVAL;
1657
1658        err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_dn_policy);
1659        if (err < 0)
1660                return err;
1661
1662        memset(&fld, 0, sizeof(fld));
1663        fld.flowidn_proto = DNPROTO_NSP;
1664
1665        skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1666        if (skb == NULL)
1667                return -ENOBUFS;
1668        skb_reset_mac_header(skb);
1669        cb = DN_SKB_CB(skb);
1670
1671        if (tb[RTA_SRC])
1672                fld.saddr = nla_get_le16(tb[RTA_SRC]);
1673
1674        if (tb[RTA_DST])
1675                fld.daddr = nla_get_le16(tb[RTA_DST]);
1676
1677        if (tb[RTA_IIF])
1678                fld.flowidn_iif = nla_get_u32(tb[RTA_IIF]);
1679
1680        if (fld.flowidn_iif) {
1681                struct net_device *dev;
1682                if ((dev = dev_get_by_index(&init_net, fld.flowidn_iif)) == NULL) {
1683                        kfree_skb(skb);
1684                        return -ENODEV;
1685                }
1686                if (!dev->dn_ptr) {
1687                        dev_put(dev);
1688                        kfree_skb(skb);
1689                        return -ENODEV;
1690                }
1691                skb->protocol = htons(ETH_P_DNA_RT);
1692                skb->dev = dev;
1693                cb->src = fld.saddr;
1694                cb->dst = fld.daddr;
1695                local_bh_disable();
1696                err = dn_route_input(skb);
1697                local_bh_enable();
1698                memset(cb, 0, sizeof(struct dn_skb_cb));
1699                rt = (struct dn_route *)skb_dst(skb);
1700                if (!err && -rt->dst.error)
1701                        err = rt->dst.error;
1702        } else {
1703                if (tb[RTA_OIF])
1704                        fld.flowidn_oif = nla_get_u32(tb[RTA_OIF]);
1705
1706                err = dn_route_output_key((struct dst_entry **)&rt, &fld, 0);
1707        }
1708
1709        if (skb->dev)
1710                dev_put(skb->dev);
1711        skb->dev = NULL;
1712        if (err)
1713                goto out_free;
1714        skb_dst_set(skb, &rt->dst);
1715        if (rtm->rtm_flags & RTM_F_NOTIFY)
1716                rt->rt_flags |= RTCF_NOTIFY;
1717
1718        err = dn_rt_fill_info(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, RTM_NEWROUTE, 0, 0);
1719        if (err < 0) {
1720                err = -EMSGSIZE;
1721                goto out_free;
1722        }
1723
1724        return rtnl_unicast(skb, &init_net, NETLINK_CB(in_skb).portid);
1725
1726out_free:
1727        kfree_skb(skb);
1728        return err;
1729}
1730
1731/*
1732 * For routers, this is called from dn_fib_dump, but for endnodes its
1733 * called directly from the rtnetlink dispatch table.
1734 */
1735int dn_cache_dump(struct sk_buff *skb, struct netlink_callback *cb)
1736{
1737        struct net *net = sock_net(skb->sk);
1738        struct dn_route *rt;
1739        int h, s_h;
1740        int idx, s_idx;
1741        struct rtmsg *rtm;
1742
1743        if (!net_eq(net, &init_net))
1744                return 0;
1745
1746        if (nlmsg_len(cb->nlh) < sizeof(struct rtmsg))
1747                return -EINVAL;
1748
1749        rtm = nlmsg_data(cb->nlh);
1750        if (!(rtm->rtm_flags & RTM_F_CLONED))
1751                return 0;
1752
1753        s_h = cb->args[0];
1754        s_idx = idx = cb->args[1];
1755        for(h = 0; h <= dn_rt_hash_mask; h++) {
1756                if (h < s_h)
1757                        continue;
1758                if (h > s_h)
1759                        s_idx = 0;
1760                rcu_read_lock_bh();
1761                for(rt = rcu_dereference_bh(dn_rt_hash_table[h].chain), idx = 0;
1762                        rt;
1763                        rt = rcu_dereference_bh(rt->dst.dn_next), idx++) {
1764                        if (idx < s_idx)
1765                                continue;
1766                        skb_dst_set(skb, dst_clone(&rt->dst));
1767                        if (dn_rt_fill_info(skb, NETLINK_CB(cb->skb).portid,
1768                                        cb->nlh->nlmsg_seq, RTM_NEWROUTE,
1769                                        1, NLM_F_MULTI) < 0) {
1770                                skb_dst_drop(skb);
1771                                rcu_read_unlock_bh();
1772                                goto done;
1773                        }
1774                        skb_dst_drop(skb);
1775                }
1776                rcu_read_unlock_bh();
1777        }
1778
1779done:
1780        cb->args[0] = h;
1781        cb->args[1] = idx;
1782        return skb->len;
1783}
1784
1785#ifdef CONFIG_PROC_FS
1786struct dn_rt_cache_iter_state {
1787        int bucket;
1788};
1789
1790static struct dn_route *dn_rt_cache_get_first(struct seq_file *seq)
1791{
1792        struct dn_route *rt = NULL;
1793        struct dn_rt_cache_iter_state *s = seq->private;
1794
1795        for(s->bucket = dn_rt_hash_mask; s->bucket >= 0; --s->bucket) {
1796                rcu_read_lock_bh();
1797                rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1798                if (rt)
1799                        break;
1800                rcu_read_unlock_bh();
1801        }
1802        return rt;
1803}
1804
1805static struct dn_route *dn_rt_cache_get_next(struct seq_file *seq, struct dn_route *rt)
1806{
1807        struct dn_rt_cache_iter_state *s = seq->private;
1808
1809        rt = rcu_dereference_bh(rt->dst.dn_next);
1810        while (!rt) {
1811                rcu_read_unlock_bh();
1812                if (--s->bucket < 0)
1813                        break;
1814                rcu_read_lock_bh();
1815                rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1816        }
1817        return rt;
1818}
1819
1820static void *dn_rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
1821{
1822        struct dn_route *rt = dn_rt_cache_get_first(seq);
1823
1824        if (rt) {
1825                while(*pos && (rt = dn_rt_cache_get_next(seq, rt)))
1826                        --*pos;
1827        }
1828        return *pos ? NULL : rt;
1829}
1830
1831static void *dn_rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1832{
1833        struct dn_route *rt = dn_rt_cache_get_next(seq, v);
1834        ++*pos;
1835        return rt;
1836}
1837
1838static void dn_rt_cache_seq_stop(struct seq_file *seq, void *v)
1839{
1840        if (v)
1841                rcu_read_unlock_bh();
1842}
1843
1844static int dn_rt_cache_seq_show(struct seq_file *seq, void *v)
1845{
1846        struct dn_route *rt = v;
1847        char buf1[DN_ASCBUF_LEN], buf2[DN_ASCBUF_LEN];
1848
1849        seq_printf(seq, "%-8s %-7s %-7s %04d %04d %04d\n",
1850                   rt->dst.dev ? rt->dst.dev->name : "*",
1851                   dn_addr2asc(le16_to_cpu(rt->rt_daddr), buf1),
1852                   dn_addr2asc(le16_to_cpu(rt->rt_saddr), buf2),
1853                   atomic_read(&rt->dst.__refcnt),
1854                   rt->dst.__use, 0);
1855        return 0;
1856}
1857
1858static const struct seq_operations dn_rt_cache_seq_ops = {
1859        .start  = dn_rt_cache_seq_start,
1860        .next   = dn_rt_cache_seq_next,
1861        .stop   = dn_rt_cache_seq_stop,
1862        .show   = dn_rt_cache_seq_show,
1863};
1864
1865static int dn_rt_cache_seq_open(struct inode *inode, struct file *file)
1866{
1867        return seq_open_private(file, &dn_rt_cache_seq_ops,
1868                        sizeof(struct dn_rt_cache_iter_state));
1869}
1870
1871static const struct file_operations dn_rt_cache_seq_fops = {
1872        .owner   = THIS_MODULE,
1873        .open    = dn_rt_cache_seq_open,
1874        .read    = seq_read,
1875        .llseek  = seq_lseek,
1876        .release = seq_release_private,
1877};
1878
1879#endif /* CONFIG_PROC_FS */
1880
1881void __init dn_route_init(void)
1882{
1883        int i, goal, order;
1884
1885        dn_dst_ops.kmem_cachep =
1886                kmem_cache_create("dn_dst_cache", sizeof(struct dn_route), 0,
1887                                  SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
1888        dst_entries_init(&dn_dst_ops);
1889        setup_timer(&dn_route_timer, dn_dst_check_expire, 0);
1890        dn_route_timer.expires = jiffies + decnet_dst_gc_interval * HZ;
1891        add_timer(&dn_route_timer);
1892
1893        goal = totalram_pages >> (26 - PAGE_SHIFT);
1894
1895        for(order = 0; (1UL << order) < goal; order++)
1896                /* NOTHING */;
1897
1898        /*
1899         * Only want 1024 entries max, since the table is very, very unlikely
1900         * to be larger than that.
1901         */
1902        while(order && ((((1UL << order) * PAGE_SIZE) /
1903                                sizeof(struct dn_rt_hash_bucket)) >= 2048))
1904                order--;
1905
1906        do {
1907                dn_rt_hash_mask = (1UL << order) * PAGE_SIZE /
1908                        sizeof(struct dn_rt_hash_bucket);
1909                while(dn_rt_hash_mask & (dn_rt_hash_mask - 1))
1910                        dn_rt_hash_mask--;
1911                dn_rt_hash_table = (struct dn_rt_hash_bucket *)
1912                        __get_free_pages(GFP_ATOMIC, order);
1913        } while (dn_rt_hash_table == NULL && --order > 0);
1914
1915        if (!dn_rt_hash_table)
1916                panic("Failed to allocate DECnet route cache hash table\n");
1917
1918        printk(KERN_INFO
1919                "DECnet: Routing cache hash table of %u buckets, %ldKbytes\n",
1920                dn_rt_hash_mask,
1921                (long)(dn_rt_hash_mask*sizeof(struct dn_rt_hash_bucket))/1024);
1922
1923        dn_rt_hash_mask--;
1924        for(i = 0; i <= dn_rt_hash_mask; i++) {
1925                spin_lock_init(&dn_rt_hash_table[i].lock);
1926                dn_rt_hash_table[i].chain = NULL;
1927        }
1928
1929        dn_dst_ops.gc_thresh = (dn_rt_hash_mask + 1);
1930
1931        proc_create("decnet_cache", S_IRUGO, init_net.proc_net,
1932                    &dn_rt_cache_seq_fops);
1933
1934#ifdef CONFIG_DECNET_ROUTER
1935        rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute,
1936                      dn_fib_dump, NULL);
1937#else
1938        rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute,
1939                      dn_cache_dump, NULL);
1940#endif
1941}
1942
1943void __exit dn_route_cleanup(void)
1944{
1945        del_timer(&dn_route_timer);
1946        dn_run_flush(0);
1947
1948        remove_proc_entry("decnet_cache", init_net.proc_net);
1949        dst_entries_destroy(&dn_dst_ops);
1950}
1951
1952