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