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/slab.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 <linux/atomic.h>
  42#include <net/net_namespace.h>
  43#include <net/neighbour.h>
  44#include <net/dst.h>
  45#include <net/flow.h>
  46#include <net/dn.h>
  47#include <net/dn_dev.h>
  48#include <net/dn_neigh.h>
  49#include <net/dn_route.h>
  50
  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 neighbour *, struct sk_buff *);
  55static int dn_short_output(struct neighbour *, struct sk_buff *);
  56static int dn_phase3_output(struct neighbour *, struct sk_buff *);
  57
  58
  59/*
  60 * For talking to broadcast devices: Ethernet & PPP
  61 */
  62static const 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};
  68
  69/*
  70 * For talking to pointopoint and multidrop devices: DDCMP and X.25
  71 */
  72static const struct neigh_ops dn_short_ops = {
  73        .family =               AF_DECnet,
  74        .error_report =         dn_short_error_report,
  75        .output =               dn_short_output,
  76        .connected_output =     dn_short_output,
  77};
  78
  79/*
  80 * For talking to DECnet phase III nodes
  81 */
  82static const struct neigh_ops dn_phase3_ops = {
  83        .family =               AF_DECnet,
  84        .error_report =         dn_short_error_report, /* Can use short version here */
  85        .output =               dn_phase3_output,
  86        .connected_output =     dn_phase3_output,
  87};
  88
  89static u32 dn_neigh_hash(const void *pkey,
  90                         const struct net_device *dev,
  91                         __u32 *hash_rnd)
  92{
  93        return jhash_2words(*(__u16 *)pkey, 0, hash_rnd[0]);
  94}
  95
  96struct neigh_table dn_neigh_table = {
  97        .family =                       PF_DECnet,
  98        .entry_size =                   sizeof(struct dn_neigh),
  99        .key_len =                      sizeof(__le16),
 100        .hash =                         dn_neigh_hash,
 101        .constructor =                  dn_neigh_construct,
 102        .id =                           "dn_neigh_cache",
 103        .parms ={
 104                .tbl =                  &dn_neigh_table,
 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_bytes =      64*1024,
 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
 125static int dn_neigh_construct(struct neighbour *neigh)
 126{
 127        struct net_device *dev = neigh->dev;
 128        struct dn_neigh *dn = (struct dn_neigh *)neigh;
 129        struct dn_dev *dn_db;
 130        struct neigh_parms *parms;
 131
 132        rcu_read_lock();
 133        dn_db = rcu_dereference(dev->dn_ptr);
 134        if (dn_db == NULL) {
 135                rcu_read_unlock();
 136                return -EINVAL;
 137        }
 138
 139        parms = dn_db->neigh_parms;
 140        if (!parms) {
 141                rcu_read_unlock();
 142                return -EINVAL;
 143        }
 144
 145        __neigh_parms_put(neigh->parms);
 146        neigh->parms = neigh_parms_clone(parms);
 147
 148        if (dn_db->use_long)
 149                neigh->ops = &dn_long_ops;
 150        else
 151                neigh->ops = &dn_short_ops;
 152        rcu_read_unlock();
 153
 154        if (dn->flags & DN_NDFLAG_P3)
 155                neigh->ops = &dn_phase3_ops;
 156
 157        neigh->nud_state = NUD_NOARP;
 158        neigh->output = neigh->ops->connected_output;
 159
 160        if ((dev->type == ARPHRD_IPGRE) || (dev->flags & IFF_POINTOPOINT))
 161                memcpy(neigh->ha, dev->broadcast, dev->addr_len);
 162        else if ((dev->type == ARPHRD_ETHER) || (dev->type == ARPHRD_LOOPBACK))
 163                dn_dn2eth(neigh->ha, dn->addr);
 164        else {
 165                net_dbg_ratelimited("Trying to create neigh for hw %d\n",
 166                                    dev->type);
 167                return -EINVAL;
 168        }
 169
 170        /*
 171         * Make an estimate of the remote block size by assuming that its
 172         * two less then the device mtu, which it true for ethernet (and
 173         * other things which support long format headers) since there is
 174         * an extra length field (of 16 bits) which isn't part of the
 175         * ethernet headers and which the DECnet specs won't admit is part
 176         * of the DECnet routing headers either.
 177         *
 178         * If we over estimate here its no big deal, the NSP negotiations
 179         * will prevent us from sending packets which are too large for the
 180         * remote node to handle. In any case this figure is normally updated
 181         * by a hello message in most cases.
 182         */
 183        dn->blksize = dev->mtu - 2;
 184
 185        return 0;
 186}
 187
 188static void dn_long_error_report(struct neighbour *neigh, struct sk_buff *skb)
 189{
 190        printk(KERN_DEBUG "dn_long_error_report: called\n");
 191        kfree_skb(skb);
 192}
 193
 194
 195static void dn_short_error_report(struct neighbour *neigh, struct sk_buff *skb)
 196{
 197        printk(KERN_DEBUG "dn_short_error_report: called\n");
 198        kfree_skb(skb);
 199}
 200
 201static int dn_neigh_output_packet(struct sk_buff *skb)
 202{
 203        struct dst_entry *dst = skb_dst(skb);
 204        struct dn_route *rt = (struct dn_route *)dst;
 205        struct neighbour *neigh = rt->n;
 206        struct net_device *dev = neigh->dev;
 207        char mac_addr[ETH_ALEN];
 208        unsigned int seq;
 209        int err;
 210
 211        dn_dn2eth(mac_addr, rt->rt_local_src);
 212        do {
 213                seq = read_seqbegin(&neigh->ha_lock);
 214                err = dev_hard_header(skb, dev, ntohs(skb->protocol),
 215                                      neigh->ha, mac_addr, skb->len);
 216        } while (read_seqretry(&neigh->ha_lock, seq));
 217
 218        if (err >= 0)
 219                err = dev_queue_xmit(skb);
 220        else {
 221                kfree_skb(skb);
 222                err = -EINVAL;
 223        }
 224        return err;
 225}
 226
 227static int dn_long_output(struct neighbour *neigh, struct sk_buff *skb)
 228{
 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                        net_crit_ratelimited("dn_long_output: no memory\n");
 240                        kfree_skb(skb);
 241                        return -ENOBUFS;
 242                }
 243                consume_skb(skb);
 244                skb = skb2;
 245                net_info_ratelimited("dn_long_output: Increasing headroom\n");
 246        }
 247
 248        data = skb_push(skb, sizeof(struct dn_long_packet) + 3);
 249        lp = (struct dn_long_packet *)(data+3);
 250
 251        *((__le16 *)data) = cpu_to_le16(skb->len - 2);
 252        *(data + 2) = 1 | DN_RT_F_PF; /* Padding */
 253
 254        lp->msgflg   = DN_RT_PKT_LONG|(cb->rt_flags&(DN_RT_F_IE|DN_RT_F_RQR|DN_RT_F_RTS));
 255        lp->d_area   = lp->d_subarea = 0;
 256        dn_dn2eth(lp->d_id, cb->dst);
 257        lp->s_area   = lp->s_subarea = 0;
 258        dn_dn2eth(lp->s_id, cb->src);
 259        lp->nl2      = 0;
 260        lp->visit_ct = cb->hops & 0x3f;
 261        lp->s_class  = 0;
 262        lp->pt       = 0;
 263
 264        skb_reset_network_header(skb);
 265
 266        return NF_HOOK(NFPROTO_DECNET, NF_DN_POST_ROUTING, skb, NULL,
 267                       neigh->dev, dn_neigh_output_packet);
 268}
 269
 270static int dn_short_output(struct neighbour *neigh, struct sk_buff *skb)
 271{
 272        struct net_device *dev = neigh->dev;
 273        int headroom = dev->hard_header_len + sizeof(struct dn_short_packet) + 2;
 274        struct dn_short_packet *sp;
 275        unsigned char *data;
 276        struct dn_skb_cb *cb = DN_SKB_CB(skb);
 277
 278
 279        if (skb_headroom(skb) < headroom) {
 280                struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom);
 281                if (skb2 == NULL) {
 282                        net_crit_ratelimited("dn_short_output: no memory\n");
 283                        kfree_skb(skb);
 284                        return -ENOBUFS;
 285                }
 286                consume_skb(skb);
 287                skb = skb2;
 288                net_info_ratelimited("dn_short_output: Increasing headroom\n");
 289        }
 290
 291        data = skb_push(skb, sizeof(struct dn_short_packet) + 2);
 292        *((__le16 *)data) = cpu_to_le16(skb->len - 2);
 293        sp = (struct dn_short_packet *)(data+2);
 294
 295        sp->msgflg     = DN_RT_PKT_SHORT|(cb->rt_flags&(DN_RT_F_RQR|DN_RT_F_RTS));
 296        sp->dstnode    = cb->dst;
 297        sp->srcnode    = cb->src;
 298        sp->forward    = cb->hops & 0x3f;
 299
 300        skb_reset_network_header(skb);
 301
 302        return NF_HOOK(NFPROTO_DECNET, NF_DN_POST_ROUTING, skb, NULL,
 303                       neigh->dev, dn_neigh_output_packet);
 304}
 305
 306/*
 307 * Phase 3 output is the same is short output, execpt that
 308 * it clears the area bits before transmission.
 309 */
 310static int dn_phase3_output(struct neighbour *neigh, struct sk_buff *skb)
 311{
 312        struct net_device *dev = neigh->dev;
 313        int headroom = dev->hard_header_len + sizeof(struct dn_short_packet) + 2;
 314        struct dn_short_packet *sp;
 315        unsigned char *data;
 316        struct dn_skb_cb *cb = DN_SKB_CB(skb);
 317
 318        if (skb_headroom(skb) < headroom) {
 319                struct sk_buff *skb2 = skb_realloc_headroom(skb, headroom);
 320                if (skb2 == NULL) {
 321                        net_crit_ratelimited("dn_phase3_output: no memory\n");
 322                        kfree_skb(skb);
 323                        return -ENOBUFS;
 324                }
 325                consume_skb(skb);
 326                skb = skb2;
 327                net_info_ratelimited("dn_phase3_output: Increasing headroom\n");
 328        }
 329
 330        data = skb_push(skb, sizeof(struct dn_short_packet) + 2);
 331        *((__le16 *)data) = cpu_to_le16(skb->len - 2);
 332        sp = (struct dn_short_packet *)(data + 2);
 333
 334        sp->msgflg   = DN_RT_PKT_SHORT|(cb->rt_flags&(DN_RT_F_RQR|DN_RT_F_RTS));
 335        sp->dstnode  = cb->dst & cpu_to_le16(0x03ff);
 336        sp->srcnode  = cb->src & cpu_to_le16(0x03ff);
 337        sp->forward  = cb->hops & 0x3f;
 338
 339        skb_reset_network_header(skb);
 340
 341        return NF_HOOK(NFPROTO_DECNET, NF_DN_POST_ROUTING, skb, NULL,
 342                       neigh->dev, dn_neigh_output_packet);
 343}
 344
 345/*
 346 * Unfortunately, the neighbour code uses the device in its hash
 347 * function, so we don't get any advantage from it. This function
 348 * basically does a neigh_lookup(), but without comparing the device
 349 * field. This is required for the On-Ethernet cache
 350 */
 351
 352/*
 353 * Pointopoint link receives a hello message
 354 */
 355void dn_neigh_pointopoint_hello(struct sk_buff *skb)
 356{
 357        kfree_skb(skb);
 358}
 359
 360/*
 361 * Ethernet router hello message received
 362 */
 363int dn_neigh_router_hello(struct sk_buff *skb)
 364{
 365        struct rtnode_hello_message *msg = (struct rtnode_hello_message *)skb->data;
 366
 367        struct neighbour *neigh;
 368        struct dn_neigh *dn;
 369        struct dn_dev *dn_db;
 370        __le16 src;
 371
 372        src = dn_eth2dn(msg->id);
 373
 374        neigh = __neigh_lookup(&dn_neigh_table, &src, skb->dev, 1);
 375
 376        dn = (struct dn_neigh *)neigh;
 377
 378        if (neigh) {
 379                write_lock(&neigh->lock);
 380
 381                neigh->used = jiffies;
 382                dn_db = rcu_dereference(neigh->dev->dn_ptr);
 383
 384                if (!(neigh->nud_state & NUD_PERMANENT)) {
 385                        neigh->updated = jiffies;
 386
 387                        if (neigh->dev->type == ARPHRD_ETHER)
 388                                memcpy(neigh->ha, &eth_hdr(skb)->h_source, ETH_ALEN);
 389
 390                        dn->blksize  = le16_to_cpu(msg->blksize);
 391                        dn->priority = msg->priority;
 392
 393                        dn->flags &= ~DN_NDFLAG_P3;
 394
 395                        switch (msg->iinfo & DN_RT_INFO_TYPE) {
 396                        case DN_RT_INFO_L1RT:
 397                                dn->flags &=~DN_NDFLAG_R2;
 398                                dn->flags |= DN_NDFLAG_R1;
 399                                break;
 400                        case DN_RT_INFO_L2RT:
 401                                dn->flags |= DN_NDFLAG_R2;
 402                        }
 403                }
 404
 405                /* Only use routers in our area */
 406                if ((le16_to_cpu(src)>>10) == (le16_to_cpu((decnet_address))>>10)) {
 407                        if (!dn_db->router) {
 408                                dn_db->router = neigh_clone(neigh);
 409                        } else {
 410                                if (msg->priority > ((struct dn_neigh *)dn_db->router)->priority)
 411                                        neigh_release(xchg(&dn_db->router, neigh_clone(neigh)));
 412                        }
 413                }
 414                write_unlock(&neigh->lock);
 415                neigh_release(neigh);
 416        }
 417
 418        kfree_skb(skb);
 419        return 0;
 420}
 421
 422/*
 423 * Endnode hello message received
 424 */
 425int dn_neigh_endnode_hello(struct sk_buff *skb)
 426{
 427        struct endnode_hello_message *msg = (struct endnode_hello_message *)skb->data;
 428        struct neighbour *neigh;
 429        struct dn_neigh *dn;
 430        __le16 src;
 431
 432        src = dn_eth2dn(msg->id);
 433
 434        neigh = __neigh_lookup(&dn_neigh_table, &src, skb->dev, 1);
 435
 436        dn = (struct dn_neigh *)neigh;
 437
 438        if (neigh) {
 439                write_lock(&neigh->lock);
 440
 441                neigh->used = jiffies;
 442
 443                if (!(neigh->nud_state & NUD_PERMANENT)) {
 444                        neigh->updated = jiffies;
 445
 446                        if (neigh->dev->type == ARPHRD_ETHER)
 447                                memcpy(neigh->ha, &eth_hdr(skb)->h_source, ETH_ALEN);
 448                        dn->flags   &= ~(DN_NDFLAG_R1 | DN_NDFLAG_R2);
 449                        dn->blksize  = le16_to_cpu(msg->blksize);
 450                        dn->priority = 0;
 451                }
 452
 453                write_unlock(&neigh->lock);
 454                neigh_release(neigh);
 455        }
 456
 457        kfree_skb(skb);
 458        return 0;
 459}
 460
 461static char *dn_find_slot(char *base, int max, int priority)
 462{
 463        int i;
 464        unsigned char *min = NULL;
 465
 466        base += 6; /* skip first id */
 467
 468        for(i = 0; i < max; i++) {
 469                if (!min || (*base < *min))
 470                        min = base;
 471                base += 7; /* find next priority */
 472        }
 473
 474        if (!min)
 475                return NULL;
 476
 477        return (*min < priority) ? (min - 6) : NULL;
 478}
 479
 480struct elist_cb_state {
 481        struct net_device *dev;
 482        unsigned char *ptr;
 483        unsigned char *rs;
 484        int t, n;
 485};
 486
 487static void neigh_elist_cb(struct neighbour *neigh, void *_info)
 488{
 489        struct elist_cb_state *s = _info;
 490        struct dn_neigh *dn;
 491
 492        if (neigh->dev != s->dev)
 493                return;
 494
 495        dn = (struct dn_neigh *) neigh;
 496        if (!(dn->flags & (DN_NDFLAG_R1|DN_NDFLAG_R2)))
 497                return;
 498
 499        if (s->t == s->n)
 500                s->rs = dn_find_slot(s->ptr, s->n, dn->priority);
 501        else
 502                s->t++;
 503        if (s->rs == NULL)
 504                return;
 505
 506        dn_dn2eth(s->rs, dn->addr);
 507        s->rs += 6;
 508        *(s->rs) = neigh->nud_state & NUD_CONNECTED ? 0x80 : 0x0;
 509        *(s->rs) |= dn->priority;
 510        s->rs++;
 511}
 512
 513int dn_neigh_elist(struct net_device *dev, unsigned char *ptr, int n)
 514{
 515        struct elist_cb_state state;
 516
 517        state.dev = dev;
 518        state.t = 0;
 519        state.n = n;
 520        state.ptr = ptr;
 521        state.rs = ptr;
 522
 523        neigh_for_each(&dn_neigh_table, neigh_elist_cb, &state);
 524
 525        return state.t;
 526}
 527
 528
 529#ifdef CONFIG_PROC_FS
 530
 531static inline void dn_neigh_format_entry(struct seq_file *seq,
 532                                         struct neighbour *n)
 533{
 534        struct dn_neigh *dn = (struct dn_neigh *) n;
 535        char buf[DN_ASCBUF_LEN];
 536
 537        read_lock(&n->lock);
 538        seq_printf(seq, "%-7s %s%s%s   %02x    %02d  %07ld %-8s\n",
 539                   dn_addr2asc(le16_to_cpu(dn->addr), buf),
 540                   (dn->flags&DN_NDFLAG_R1) ? "1" : "-",
 541                   (dn->flags&DN_NDFLAG_R2) ? "2" : "-",
 542                   (dn->flags&DN_NDFLAG_P3) ? "3" : "-",
 543                   dn->n.nud_state,
 544                   atomic_read(&dn->n.refcnt),
 545                   dn->blksize,
 546                   (dn->n.dev) ? dn->n.dev->name : "?");
 547        read_unlock(&n->lock);
 548}
 549
 550static int dn_neigh_seq_show(struct seq_file *seq, void *v)
 551{
 552        if (v == SEQ_START_TOKEN) {
 553                seq_puts(seq, "Addr    Flags State Use Blksize Dev\n");
 554        } else {
 555                dn_neigh_format_entry(seq, v);
 556        }
 557
 558        return 0;
 559}
 560
 561static void *dn_neigh_seq_start(struct seq_file *seq, loff_t *pos)
 562{
 563        return neigh_seq_start(seq, pos, &dn_neigh_table,
 564                               NEIGH_SEQ_NEIGH_ONLY);
 565}
 566
 567static const struct seq_operations dn_neigh_seq_ops = {
 568        .start = dn_neigh_seq_start,
 569        .next  = neigh_seq_next,
 570        .stop  = neigh_seq_stop,
 571        .show  = dn_neigh_seq_show,
 572};
 573
 574static int dn_neigh_seq_open(struct inode *inode, struct file *file)
 575{
 576        return seq_open_net(inode, file, &dn_neigh_seq_ops,
 577                            sizeof(struct neigh_seq_state));
 578}
 579
 580static const struct file_operations dn_neigh_seq_fops = {
 581        .owner          = THIS_MODULE,
 582        .open           = dn_neigh_seq_open,
 583        .read           = seq_read,
 584        .llseek         = seq_lseek,
 585        .release        = seq_release_net,
 586};
 587
 588#endif
 589
 590void __init dn_neigh_init(void)
 591{
 592        neigh_table_init(&dn_neigh_table);
 593        proc_net_fops_create(&init_net, "decnet_neigh", S_IRUGO, &dn_neigh_seq_fops);
 594}
 595
 596void __exit dn_neigh_cleanup(void)
 597{
 598        proc_net_remove(&init_net, "decnet_neigh");
 599        neigh_table_clear(&dn_neigh_table);
 600}
 601
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.