linux/net/decnet/dn_neigh.c
<<
>>
Prefs
   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/net.h>
  28#include <linux/module.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/net_namespace.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
  50static u32 dn_neigh_hash(const void *pkey, const struct net_device *dev);
  51static int dn_neigh_construct(struct neighbour *);
  52static void dn_long_error_report(struct neighbour *, struct sk_buff *);
  53static void dn_short_error_report(struct neighbour *, struct sk_buff *);
  54static int dn_long_output(struct sk_buff *);
  55static int dn_short_output(struct sk_buff *);
  56static int dn_phase3_output(struct sk_buff *);
  57
  58
  59/*
  60 * For talking to broadcast devices: Ethernet & PPP
  61 */
  62static 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 */
  74static 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 */
  86static 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
  95struct neigh_table dn_neigh_table = {
  96        .family =                       PF_DECnet,
  97        .entry_size =                   sizeof(struct dn_neigh),
  98        .key_len =                      sizeof(__le16),
  99        .hash =                         dn_neigh_hash,
 100        .constructor =                  dn_neigh_construct,
 101        .id =                           "dn_neigh_cache",
 102        .parms ={
 103                .tbl =                  &dn_neigh_table,
 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
 124static u32 dn_neigh_hash(const void *pkey, const struct net_device *dev)
 125{
 126        return jhash_2words(*(__u16 *)pkey, 0, dn_neigh_table.hash_rnd);
 127}
 128
 129static 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
 152        if (dn_db->use_long)
 153                neigh->ops = &dn_long_ops;
 154        else
 155                neigh->ops = &dn_short_ops;
 156        rcu_read_unlock();
 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
 192static 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
 199static 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
 205static 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(skb, dev, ntohs(skb->protocol), neigh->ha,
 215                            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
 225static 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        *((__le16 *)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, cb->dst);
 259        lp->s_area   = lp->s_subarea = 0;
 260        dn_dn2eth(lp->s_id, 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_reset_network_header(skb);
 267
 268        return NF_HOOK(PF_DECnet, NF_DN_POST_ROUTING, skb, NULL, neigh->dev, dn_neigh_output_packet);
 269}
 270
 271static 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        *((__le16 *)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_reset_network_header(skb);
 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 */
 314static 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        *((__le16 *)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_reset_network_header(skb);
 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 */
 362void dn_neigh_pointopoint_hello(struct sk_buff *skb)
 363{
 364        kfree_skb(skb);
 365}
 366
 367/*
 368 * Ethernet router hello message received
 369 */
 370int 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        __le16 src;
 378
 379        src = 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                /* Only use routers in our area */
 413                if ((dn_ntohs(src)>>10) == (dn_ntohs((decnet_address))>>10)) {
 414                        if (!dn_db->router) {
 415                                dn_db->router = neigh_clone(neigh);
 416                        } else {
 417                                if (msg->priority > ((struct dn_neigh *)dn_db->router)->priority)
 418                                        neigh_release(xchg(&dn_db->router, neigh_clone(neigh)));
 419                        }
 420                }
 421                write_unlock(&neigh->lock);
 422                neigh_release(neigh);
 423        }
 424
 425        kfree_skb(skb);
 426        return 0;
 427}
 428
 429/*
 430 * Endnode hello message received
 431 */
 432int dn_neigh_endnode_hello(struct sk_buff *skb)
 433{
 434        struct endnode_hello_message *msg = (struct endnode_hello_message *)skb->data;
 435        struct neighbour *neigh;
 436        struct dn_neigh *dn;
 437        __le16 src;
 438
 439        src = dn_eth2dn(msg->id);
 440
 441        neigh = __neigh_lookup(&dn_neigh_table, &src, skb->dev, 1);
 442
 443        dn = (struct dn_neigh *)neigh;
 444
 445        if (neigh) {
 446                write_lock(&neigh->lock);
 447
 448                neigh->used = jiffies;
 449
 450                if (!(neigh->nud_state & NUD_PERMANENT)) {
 451                        neigh->updated = jiffies;
 452
 453                        if (neigh->dev->type == ARPHRD_ETHER)
 454                                memcpy(neigh->ha, &eth_hdr(skb)->h_source, ETH_ALEN);
 455                        dn->flags   &= ~(DN_NDFLAG_R1 | DN_NDFLAG_R2);
 456                        dn->blksize  = dn_ntohs(msg->blksize);
 457                        dn->priority = 0;
 458                }
 459
 460                write_unlock(&neigh->lock);
 461                neigh_release(neigh);
 462        }
 463
 464        kfree_skb(skb);
 465        return 0;
 466}
 467
 468static char *dn_find_slot(char *base, int max, int priority)
 469{
 470        int i;
 471        unsigned char *min = NULL;
 472
 473        base += 6; /* skip first id */
 474
 475        for(i = 0; i < max; i++) {
 476                if (!min || (*base < *min))
 477                        min = base;
 478                base += 7; /* find next priority */
 479        }
 480
 481        if (!min)
 482                return NULL;
 483
 484        return (*min < priority) ? (min - 6) : NULL;
 485}
 486
 487struct elist_cb_state {
 488        struct net_device *dev;
 489        unsigned char *ptr;
 490        unsigned char *rs;
 491        int t, n;
 492};
 493
 494static void neigh_elist_cb(struct neighbour *neigh, void *_info)
 495{
 496        struct elist_cb_state *s = _info;
 497        struct dn_neigh *dn;
 498
 499        if (neigh->dev != s->dev)
 500                return;
 501
 502        dn = (struct dn_neigh *) neigh;
 503        if (!(dn->flags & (DN_NDFLAG_R1|DN_NDFLAG_R2)))
 504                return;
 505
 506        if (s->t == s->n)
 507                s->rs = dn_find_slot(s->ptr, s->n, dn->priority);
 508        else
 509                s->t++;
 510        if (s->rs == NULL)
 511                return;
 512
 513        dn_dn2eth(s->rs, dn->addr);
 514        s->rs += 6;
 515        *(s->rs) = neigh->nud_state & NUD_CONNECTED ? 0x80 : 0x0;
 516        *(s->rs) |= dn->priority;
 517        s->rs++;
 518}
 519
 520int dn_neigh_elist(struct net_device *dev, unsigned char *ptr, int n)
 521{
 522        struct elist_cb_state state;
 523
 524        state.dev = dev;
 525        state.t = 0;
 526        state.n = n;
 527        state.ptr = ptr;
 528        state.rs = ptr;
 529
 530        neigh_for_each(&dn_neigh_table, neigh_elist_cb, &state);
 531
 532        return state.t;
 533}
 534
 535
 536#ifdef CONFIG_PROC_FS
 537
 538static inline void dn_neigh_format_entry(struct seq_file *seq,
 539                                         struct neighbour *n)
 540{
 541        struct dn_neigh *dn = (struct dn_neigh *) n;
 542        char buf[DN_ASCBUF_LEN];
 543
 544        read_lock(&n->lock);
 545        seq_printf(seq, "%-7s %s%s%s   %02x    %02d  %07ld %-8s\n",
 546                   dn_addr2asc(dn_ntohs(dn->addr), buf),
 547                   (dn->flags&DN_NDFLAG_R1) ? "1" : "-",
 548                   (dn->flags&DN_NDFLAG_R2) ? "2" : "-",
 549                   (dn->flags&DN_NDFLAG_P3) ? "3" : "-",
 550                   dn->n.nud_state,
 551                   atomic_read(&dn->n.refcnt),
 552                   dn->blksize,
 553                   (dn->n.dev) ? dn->n.dev->name : "?");
 554        read_unlock(&n->lock);
 555}
 556
 557static int dn_neigh_seq_show(struct seq_file *seq, void *v)
 558{
 559        if (v == SEQ_START_TOKEN) {
 560                seq_puts(seq, "Addr    Flags State Use Blksize Dev\n");
 561        } else {
 562                dn_neigh_format_entry(seq, v);
 563        }
 564
 565        return 0;
 566}
 567
 568static void *dn_neigh_seq_start(struct seq_file *seq, loff_t *pos)
 569{
 570        return neigh_seq_start(seq, pos, &dn_neigh_table,
 571                               NEIGH_SEQ_NEIGH_ONLY);
 572}
 573
 574static const struct seq_operations dn_neigh_seq_ops = {
 575        .start = dn_neigh_seq_start,
 576        .next  = neigh_seq_next,
 577        .stop  = neigh_seq_stop,
 578        .show  = dn_neigh_seq_show,
 579};
 580
 581static int dn_neigh_seq_open(struct inode *inode, struct file *file)
 582{
 583        return seq_open_net(inode, file, &dn_neigh_seq_ops,
 584                            sizeof(struct neigh_seq_state));
 585}
 586
 587static const struct file_operations dn_neigh_seq_fops = {
 588        .owner          = THIS_MODULE,
 589        .open           = dn_neigh_seq_open,
 590        .read           = seq_read,
 591        .llseek         = seq_lseek,
 592        .release        = seq_release_net,
 593};
 594
 595#endif
 596
 597void __init dn_neigh_init(void)
 598{
 599        neigh_table_init(&dn_neigh_table);
 600        proc_net_fops_create(&init_net, "decnet_neigh", S_IRUGO, &dn_neigh_seq_fops);
 601}
 602
 603void __exit dn_neigh_cleanup(void)
 604{
 605        proc_net_remove(&init_net, "decnet_neigh");
 606        neigh_table_clear(&dn_neigh_table);
 607}
 608
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.