net/decnet/dn_neigh.c

   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 Neighbour Functions (Adjacency Database and
   7  *                                                        On-Ethernet Cache)
   8  *
   9  * Author:      Steve Whitehouse <SteveW@ACM.org>
  10  *
  11  *
  12  * Changes:
  13  *     Steve Whitehouse     : Fixed router listing routine
  14  *     Steve Whitehouse     : Added error_report functions
  15  *     Steve Whitehouse     : Added default router detection
  16  *     Steve Whitehouse     : Hop counts in outgoing messages
  17  *     Steve Whitehouse     : Fixed src/dst in outgoing messages so
  18  *                            forwarding now stands a good chance of
  19  *                            working.
  20  *     Steve Whitehouse     : Fixed neighbour states (for now anyway).
  21  *     Steve Whitehouse     : Made error_report functions dummies. This
  22  *                            is not the right place to return skbs.
  23  *     Steve Whitehouse     : Convert to seq_file
  24  *
  25  */
  26
  27 #include <linux/config.h>
  28 #include <linux/net.h>
  29 #include <linux/socket.h>
  30 #include <linux/if_arp.h>
  31 #include <linux/if_ether.h>
  32 #include <linux/init.h>
  33 #include <linux/proc_fs.h>
  34 #include <linux/string.h>
  35 #include <linux/netfilter_decnet.h>
  36 #include <linux/spinlock.h>
  37 #include <linux/seq_file.h>
  38 #include <linux/rcupdate.h>
  39 #include <linux/jhash.h>
  40 #include <asm/atomic.h>
  41 #include <net/neighbour.h>
  42 #include <net/dst.h>
  43 #include <net/flow.h>
  44 #include <net/dn.h>
  45 #include <net/dn_dev.h>
  46 #include <net/dn_neigh.h>
  47 #include <net/dn_route.h>
  48
  49 static u32 dn_neigh_hash(const void *pkey, const struct net_device *dev);
  50 static int dn_neigh_construct(struct neighbour *);
  51 static void dn_long_error_report(struct neighbour *, struct sk_buff *);
  52 static void dn_short_error_report(struct neighbour *, struct sk_buff *);
  53 static int dn_long_output(struct sk_buff *);
  54 static int dn_short_output(struct sk_buff *);
  55 static int dn_phase3_output(struct sk_buff *);
  56
  57
  58 /*
  59  * For talking to broadcast devices: Ethernet & PPP
  60  */
  61 static struct neigh_ops dn_long_ops = {
  62         .family =               AF_DECnet,
  63         .error_report =         dn_long_error_report,
  64         .output =               dn_long_output,
  65         .connected_output =     dn_long_output,
  66         .hh_output =            dev_queue_xmit,
  67         .queue_xmit =           dev_queue_xmit,
  68 };
  69
  70 /*
  71  * For talking to pointopoint and multidrop devices: DDCMP and X.25
  72  */
  73 static struct neigh_ops dn_short_ops = {
  74         .family =               AF_DECnet,
  75         .error_report =         dn_short_error_report,
  76         .output =               dn_short_output,
  77         .connected_output =     dn_short_output,
  78         .hh_output =            dev_queue_xmit,
  79         .queue_xmit =           dev_queue_xmit,
  80 };
  81
  82 /*
  83  * For talking to DECnet phase III nodes
  84  */
  85 static struct neigh_ops dn_phase3_ops = {
  86         .family =               AF_DECnet,
  87         .error_report =         dn_short_error_report, /* Can use short version here */
  88         .output =               dn_phase3_output,
  89         .connected_output =     dn_phase3_output,
  90         .hh_output =            dev_queue_xmit,
  91         .queue_xmit =           dev_queue_xmit
  92 };
  93
  94 struct neigh_table dn_neigh_table = {
  95         .family =                       PF_DECnet,
  96         .entry_size =                   sizeof(struct dn_neigh),
  97         .key_len =                      sizeof(dn_address),
  98         .hash =                         dn_neigh_hash,
  99         .constructor =                  dn_neigh_construct,
 100         .id =                           "dn_neigh_cache",
 101         .parms ={
 102                 .tbl =                  &dn_neigh_table,
 103                 .entries =              0,
 104                 .base_reachable_time =  30 * HZ,
 105                 .retrans_time = 1 * HZ,
 106                 .gc_staletime = 60 * HZ,
 107                 .reachable_time =               30 * HZ,
 108                 .delay_probe_time =     5 * HZ,
 109                 .queue_len =            3,
 110                 .ucast_probes = 0,
 111                 .app_probes =           0,
 112                 .mcast_probes = 0,
 113                 .anycast_delay =        0,
 114                 .proxy_delay =          0,
 115                 .proxy_qlen =           0,
 116                 .locktime =             1 * HZ,
 117         },
 118         .gc_interval =                  30 * HZ,
 119         .gc_thresh1 =                   128,
 120         .gc_thresh2 =                   512,
 121         .gc_thresh3 =                   1024,
 122 };
 123
 124 static u32 dn_neigh_hash(const void *pkey, const struct net_device *dev)
 125 {
 126         return jhash_2words(*(dn_address *)pkey, 0, dn_neigh_table.hash_rnd);
 127 }
 128
 129 static int dn_neigh_construct(struct neighbour *neigh)
 130 {
 131         struct net_device *dev = neigh->dev;
 132         struct dn_neigh *dn = (struct dn_neigh *)neigh;
 133         struct dn_dev *dn_db;
 134         struct neigh_parms *parms;
 135
 136         rcu_read_lock();
 137         dn_db = rcu_dereference(dev->dn_ptr);
 138         if (dn_db == NULL) {
 139                 rcu_read_unlock();
 140                 return -EINVAL;
 141         }
 142
 143         parms = dn_db->neigh_parms;
 144         if (!parms) {
 145                 rcu_read_unlock();
 146                 return -EINVAL;
 147         }
 148
 149         __neigh_parms_put(neigh->parms);
 150         neigh->parms = neigh_parms_clone(parms);
 151         rcu_read_unlock();
 152
 153         if (dn_db->use_long)
 154                 neigh->ops = &dn_long_ops;
 155         else
 156                 neigh->ops = &dn_short_ops;
 157
 158         if (dn->flags & DN_NDFLAG_P3)
 159                 neigh->ops = &dn_phase3_ops;
 160
 161         neigh->nud_state = NUD_NOARP;
 162         neigh->output = neigh->ops->connected_output;
 163
 164         if ((dev->type == ARPHRD_IPGRE) || (dev->flags & IFF_POINTOPOINT))
 165                 memcpy(neigh->ha, dev->broadcast, dev->addr_len);
 166         else if ((dev->type == ARPHRD_ETHER) || (dev->type == ARPHRD_LOOPBACK))
 167                 dn_dn2eth(neigh->ha, dn->addr);
 168         else {
 169                 if (net_ratelimit())
 170                         printk(KERN_DEBUG "Trying to create neigh for hw %d\n",  dev->type);
 171                 return -EINVAL;
 172         }
 173
 174         /*
 175          * Make an estimate of the remote block size by assuming that its
 176          * two less then the device mtu, which it true for ethernet (and
 177          * other things which support long format headers) since there is
 178          * an extra length field (of 16 bits) which isn't part of the
 179          * ethernet headers and which the DECnet specs won't admit is part
 180          * of the DECnet routing headers either.
 181          *
 182          * If we over estimate here its no big deal, the NSP negotiations
 183          * will prevent us from sending packets which are too large for the
 184          * remote node to handle. In any case this figure is normally updated
 185          * by a hello message in most cases.
 186          */
 187         dn->blksize = dev->mtu - 2;
 188
 189         return 0;
 190 }
 191
 192 static void dn_long_error_report(struct neighbour *neigh, struct sk_buff *skb)
 193 {
 194         printk(KERN_DEBUG "dn_long_error_report: called\n");
 195         kfree_skb(skb);
 196 }
 197
 198
 199 static void dn_short_error_report(struct neighbour *neigh, struct sk_buff *skb)
 200 {
 201         printk(KERN_DEBUG "dn_short_error_report: called\n");
 202         kfree_skb(skb);
 203 }
 204
 205 static int dn_neigh_output_packet(struct sk_buff *skb)
 206 {
 207         struct dst_entry *dst = skb->dst;
 208         struct dn_route *rt = (struct dn_route *)dst;
 209         struct neighbour *neigh = dst->neighbour;
 210         struct net_device *dev = neigh->dev;
 211         char mac_addr[ETH_ALEN];
 212
 213         dn_dn2eth(mac_addr, rt->rt_local_src);
 214         if (!dev->hard_header || dev->hard_header(skb, dev, ntohs(skb->protocol), neigh->ha, mac_addr, skb->len) >= 0)
 215                 return neigh->ops->queue_xmit(skb);
 216
 217         if (net_ratelimit())
 218                 printk(KERN_DEBUG "dn_neigh_output_packet: oops, can't send packet\n");
 219
 220         kfree_skb(skb);
 221         return -EINVAL;
 222 }
 223
 224 static int dn_long_output(struct sk_buff *skb)
 225 {
 226         struct dst_entry *dst = skb->dst;
 227         struct neighbour *neigh = dst->neighbour;
 228         struct net_device *dev = neigh->dev;
 229         int headroom = dev->hard_header_len + sizeof(struct dn_long_packet) + 3;
 230         unsigned char *data;
 231         struct dn_long_packet *lp;
 232         struct dn_skb_cb *cb = DN_SKB_CB(skb);
 233
 234
 235         if (skb_headroom(skb) < headroom) {
 236                 struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom);
 237                 if (skb2 == NULL) {
 238                         if (net_ratelimit())
 239                                 printk(KERN_CRIT "dn_long_output: no memory\n");
 240                         kfree_skb(skb);
 241                         return -ENOBUFS;
 242                 }
 243                 kfree_skb(skb);
 244                 skb = skb2;
 245                 if (net_ratelimit())
 246                         printk(KERN_INFO "dn_long_output: Increasing headroom\n");
 247         }
 248
 249         data = skb_push(skb, sizeof(struct dn_long_packet) + 3);
 250         lp = (struct dn_long_packet *)(data+3);
 251
 252         *((unsigned short *)data) = dn_htons(skb->len - 2);
 253         *(data + 2) = 1 | DN_RT_F_PF; /* Padding */
 254
 255         lp->msgflg   = DN_RT_PKT_LONG|(cb->rt_flags&(DN_RT_F_IE|DN_RT_F_RQR|DN_RT_F_RTS));
 256         lp->d_area   = lp->d_subarea = 0;
 257         dn_dn2eth(lp->d_id, dn_ntohs(cb->dst));
 258         lp->s_area   = lp->s_subarea = 0;
 259         dn_dn2eth(lp->s_id, dn_ntohs(cb->src));
 260         lp->nl2      = 0;
 261         lp->visit_ct = cb->hops & 0x3f;
 262         lp->s_class  = 0;
 263         lp->pt       = 0;
 264
 265         skb->nh.raw = skb->data;
 266
 267         return NF_HOOK(PF_DECnet, NF_DN_POST_ROUTING, skb, NULL, neigh->dev, dn_neigh_output_packet);
 268 }
 269
 270 static int dn_short_output(struct sk_buff *skb)
 271 {
 272         struct dst_entry *dst = skb->dst;
 273         struct neighbour *neigh = dst->neighbour;
 274         struct net_device *dev = neigh->dev;
 275         int headroom = dev->hard_header_len + sizeof(struct dn_short_packet) + 2;
 276         struct dn_short_packet *sp;
 277         unsigned char *data;
 278         struct dn_skb_cb *cb = DN_SKB_CB(skb);
 279
 280
 281         if (skb_headroom(skb) < headroom) {
 282                 struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom);
 283                 if (skb2 == NULL) {
 284                         if (net_ratelimit())
 285                                 printk(KERN_CRIT "dn_short_output: no memory\n");
 286                         kfree_skb(skb);
 287                         return -ENOBUFS;
 288                 }
 289                 kfree_skb(skb);
 290                 skb = skb2;
 291                 if (net_ratelimit())
 292                         printk(KERN_INFO "dn_short_output: Increasing headroom\n");
 293         }
 294
 295         data = skb_push(skb, sizeof(struct dn_short_packet) + 2);
 296         *((unsigned short *)data) = dn_htons(skb->len - 2);
 297         sp = (struct dn_short_packet *)(data+2);
 298
 299         sp->msgflg     = DN_RT_PKT_SHORT|(cb->rt_flags&(DN_RT_F_RQR|DN_RT_F_RTS));
 300         sp->dstnode    = cb->dst;
 301         sp->srcnode    = cb->src;
 302         sp->forward    = cb->hops & 0x3f;
 303
 304         skb->nh.raw = skb->data;
 305
 306         return NF_HOOK(PF_DECnet, NF_DN_POST_ROUTING, skb, NULL, neigh->dev, dn_neigh_output_packet);
 307 }
 308
 309 /*
 310  * Phase 3 output is the same is short output, execpt that
 311  * it clears the area bits before transmission.
 312  */
 313 static int dn_phase3_output(struct sk_buff *skb)
 314 {
 315         struct dst_entry *dst = skb->dst;
 316         struct neighbour *neigh = dst->neighbour;
 317         struct net_device *dev = neigh->dev;
 318         int headroom = dev->hard_header_len + sizeof(struct dn_short_packet) + 2;
 319         struct dn_short_packet *sp;
 320         unsigned char *data;
 321         struct dn_skb_cb *cb = DN_SKB_CB(skb);
 322
 323         if (skb_headroom(skb) < headroom) {
 324                 struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom);
 325                 if (skb2 == NULL) {
 326                         if (net_ratelimit())
 327                                 printk(KERN_CRIT "dn_phase3_output: no memory\n");
 328                         kfree_skb(skb);
 329                         return -ENOBUFS;
 330                 }
 331                 kfree_skb(skb);
 332                 skb = skb2;
 333                 if (net_ratelimit())
 334                         printk(KERN_INFO "dn_phase3_output: Increasing headroom\n");
 335         }
 336
 337         data = skb_push(skb, sizeof(struct dn_short_packet) + 2);
 338         *((unsigned short *)data) = dn_htons(skb->len - 2);
 339         sp = (struct dn_short_packet *)(data + 2);
 340
 341         sp->msgflg   = DN_RT_PKT_SHORT|(cb->rt_flags&(DN_RT_F_RQR|DN_RT_F_RTS));
 342         sp->dstnode  = cb->dst & dn_htons(0x03ff);
 343         sp->srcnode  = cb->src & dn_htons(0x03ff);
 344         sp->forward  = cb->hops & 0x3f;
 345
 346         skb->nh.raw = skb->data;
 347
 348         return NF_HOOK(PF_DECnet, NF_DN_POST_ROUTING, skb, NULL, neigh->dev, dn_neigh_output_packet);
 349 }
 350
 351 /*
 352  * Unfortunately, the neighbour code uses the device in its hash
 353  * function, so we don't get any advantage from it. This function
 354  * basically does a neigh_lookup(), but without comparing the device
 355  * field. This is required for the On-Ethernet cache
 356  */
 357 /*
 358  * Any traffic on a pointopoint link causes the timer to be reset
 359  * for the entry in the neighbour table.
 360  */
 361 void dn_neigh_pointopoint_notify(struct sk_buff *skb)
 362 {
 363         return;
 364 }
 365
 366 /*
 367  * Pointopoint link receives a hello message
 368  */
 369 void dn_neigh_pointopoint_hello(struct sk_buff *skb)
 370 {
 371         kfree_skb(skb);
 372 }
 373
 374 /*
 375  * Ethernet router hello message received
 376  */
 377 int dn_neigh_router_hello(struct sk_buff *skb)
 378 {
 379         struct rtnode_hello_message *msg = (struct rtnode_hello_message *)skb->data;
 380
 381         struct neighbour *neigh;
 382         struct dn_neigh *dn;
 383         struct dn_dev *dn_db;
 384         dn_address src;
 385
 386         src = dn_htons(dn_eth2dn(msg->id));
 387
 388         neigh = __neigh_lookup(&dn_neigh_table, &src, skb->dev, 1);
 389
 390         dn = (struct dn_neigh *)neigh;
 391
 392         if (neigh) {
 393                 write_lock(&neigh->lock);
 394
 395                 neigh->used = jiffies;
 396                 dn_db = (struct dn_dev *)neigh->dev->dn_ptr;
 397
 398                 if (!(neigh->nud_state & NUD_PERMANENT)) {
 399                         neigh->updated = jiffies;
 400
 401                         if (neigh->dev->type == ARPHRD_ETHER)
 402                                 memcpy(neigh->ha, &eth_hdr(skb)->h_source, ETH_ALEN);
 403
 404                         dn->blksize  = dn_ntohs(msg->blksize);
 405                         dn->priority = msg->priority;
 406
 407                         dn->flags &= ~DN_NDFLAG_P3;
 408
 409                         switch(msg->iinfo & DN_RT_INFO_TYPE) {
 410                                 case DN_RT_INFO_L1RT:
 411                                         dn->flags &=~DN_NDFLAG_R2;
 412                                         dn->flags |= DN_NDFLAG_R1;
 413                                         break;
 414                                 case DN_RT_INFO_L2RT:
 415                                         dn->flags |= DN_NDFLAG_R2;
 416                         }
 417                 }
 418
 419                 if (!dn_db->router) {
 420                         dn_db->router = neigh_clone(neigh);
 421                 } else {
 422                         if (msg->priority > ((struct dn_neigh *)dn_db->router)->priority)
 423                                 neigh_release(xchg(&dn_db->router, neigh_clone(neigh)));
 424                 }
 425                 write_unlock(&neigh->lock);
 426                 neigh_release(neigh);
 427         }
 428
 429         kfree_skb(skb);
 430         return 0;
 431 }
 432
 433 /*
 434  * Endnode hello message received
 435  */
 436 int dn_neigh_endnode_hello(struct sk_buff *skb)
 437 {
 438         struct endnode_hello_message *msg = (struct endnode_hello_message *)skb->data;
 439         struct neighbour *neigh;
 440         struct dn_neigh *dn;
 441         dn_address src;
 442
 443         src = dn_htons(dn_eth2dn(msg->id));
 444
 445         neigh = __neigh_lookup(&dn_neigh_table, &src, skb->dev, 1);
 446
 447         dn = (struct dn_neigh *)neigh;
 448
 449         if (neigh) {
 450                 write_lock(&neigh->lock);
 451
 452                 neigh->used = jiffies;
 453
 454                 if (!(neigh->nud_state & NUD_PERMANENT)) {
 455                         neigh->updated = jiffies;
 456
 457                         if (neigh->dev->type == ARPHRD_ETHER)
 458                                 memcpy(neigh->ha, &eth_hdr(skb)->h_source, ETH_ALEN);
 459                         dn->flags   &= ~(DN_NDFLAG_R1 | DN_NDFLAG_R2);
 460                         dn->blksize  = dn_ntohs(msg->blksize);
 461                         dn->priority = 0;
 462                 }
 463
 464                 write_unlock(&neigh->lock);
 465                 neigh_release(neigh);
 466         }
 467
 468         kfree_skb(skb);
 469         return 0;
 470 }
 471
 472 static char *dn_find_slot(char *base, int max, int priority)
 473 {
 474         int i;
 475         unsigned char *min = NULL;
 476
 477         base += 6; /* skip first id */
 478
 479         for(i = 0; i < max; i++) {
 480                 if (!min || (*base < *min))
 481                         min = base;
 482                 base += 7; /* find next priority */
 483         }
 484
 485         if (!min)
 486                 return NULL;
 487
 488         return (*min < priority) ? (min - 6) : NULL;
 489 }
 490
 491 struct elist_cb_state {
 492         struct net_device *dev;
 493         unsigned char *ptr;
 494         unsigned char *rs;
 495         int t, n;
 496 };
 497
 498 static void neigh_elist_cb(struct neighbour *neigh, void *_info)
 499 {
 500         struct elist_cb_state *s = _info;
 501         struct dn_dev *dn_db;
 502         struct dn_neigh *dn;
 503
 504         if (neigh->dev != s->dev)
 505                 return;
 506
 507         dn = (struct dn_neigh *) neigh;
 508         if (!(dn->flags & (DN_NDFLAG_R1|DN_NDFLAG_R2)))
 509                 return;
 510
 511         dn_db = (struct dn_dev *) s->dev->dn_ptr;
 512         if (dn_db->parms.forwarding == 1 && (dn->flags & DN_NDFLAG_R2))
 513                 return;
 514
 515         if (s->t == s->n)
 516                 s->rs = dn_find_slot(s->ptr, s->n, dn->priority);
 517         else
 518                 s->t++;
 519         if (s->rs == NULL)
 520                 return;
 521
 522         dn_dn2eth(s->rs, dn->addr);
 523         s->rs += 6;
 524         *(s->rs) = neigh->nud_state & NUD_CONNECTED ? 0x80 : 0x0;
 525         *(s->rs) |= dn->priority;
 526         s->rs++;
 527 }
 528
 529 int dn_neigh_elist(struct net_device *dev, unsigned char *ptr, int n)
 530 {
 531         struct elist_cb_state state;
 532
 533         state.dev = dev;
 534         state.t = 0;
 535         state.n = n;
 536         state.ptr = ptr;
 537         state.rs = ptr;
 538
 539         neigh_for_each(&dn_neigh_table, neigh_elist_cb, &state);
 540
 541         return state.t;
 542 }
 543
 544
 545 #ifdef CONFIG_PROC_FS
 546
 547 static inline void dn_neigh_format_entry(struct seq_file *seq,
 548                                          struct neighbour *n)
 549 {
 550         struct dn_neigh *dn = (struct dn_neigh *) n;
 551         char buf[DN_ASCBUF_LEN];
 552
 553         read_lock(&n->lock);
 554         seq_printf(seq, "%-7s %s%s%s   %02x    %02d  %07ld %-8s\n",
 555                    dn_addr2asc(dn_ntohs(dn->addr), buf),
 556                    (dn->flags&DN_NDFLAG_R1) ? "1" : "-",
 557                    (dn->flags&DN_NDFLAG_R2) ? "2" : "-",
 558                    (dn->flags&DN_NDFLAG_P3) ? "3" : "-",
 559                    dn->n.nud_state,
 560                    atomic_read(&dn->n.refcnt),
 561                    dn->blksize,
 562                    (dn->n.dev) ? dn->n.dev->name : "?");
 563         read_unlock(&n->lock);
 564 }
 565
 566 static int dn_neigh_seq_show(struct seq_file *seq, void *v)
 567 {
 568         if (v == SEQ_START_TOKEN) {
 569                 seq_puts(seq, "Addr    Flags State Use Blksize Dev\n");
 570         } else {
 571                 dn_neigh_format_entry(seq, v);
 572         }
 573
 574         return 0;
 575 }
 576
 577 static void *dn_neigh_seq_start(struct seq_file *seq, loff_t *pos)
 578 {
 579         return neigh_seq_start(seq, pos, &dn_neigh_table,
 580                                NEIGH_SEQ_NEIGH_ONLY);
 581 }
 582
 583 static struct seq_operations dn_neigh_seq_ops = {
 584         .start = dn_neigh_seq_start,
 585         .next  = neigh_seq_next,
 586         .stop  = neigh_seq_stop,
 587         .show  = dn_neigh_seq_show,
 588 };
 589
 590 static int dn_neigh_seq_open(struct inode *inode, struct file *file)
 591 {
 592         struct seq_file *seq;
 593         int rc = -ENOMEM;
 594         struct neigh_seq_state *s = kmalloc(sizeof(*s), GFP_KERNEL);
 595
 596         if (!s)
 597                 goto out;
 598
 599         memset(s, 0, sizeof(*s));
 600         rc = seq_open(file, &dn_neigh_seq_ops);
 601         if (rc)
 602                 goto out_kfree;
 603
 604         seq          = file->private_data;
 605         seq->private = s;
 606         memset(s, 0, sizeof(*s));
 607 out:
 608         return rc;
 609 out_kfree:
 610         kfree(s);
 611         goto out;
 612 }
 613
 614 static struct file_operations dn_neigh_seq_fops = {
 615         .owner          = THIS_MODULE,
 616         .open           = dn_neigh_seq_open,
 617         .read           = seq_read,
 618         .llseek         = seq_lseek,
 619         .release        = seq_release_private,
 620 };
 621
 622 #endif
 623
 624 void __init dn_neigh_init(void)
 625 {
 626         neigh_table_init(&dn_neigh_table);
 627         proc_net_fops_create("decnet_neigh", S_IRUGO, &dn_neigh_seq_fops);
 628 }
 629
 630 void __exit dn_neigh_cleanup(void)
 631 {
 632         proc_net_remove("decnet_neigh");
 633         neigh_table_clear(&dn_neigh_table);
 634 }