linux/net/atm/clip.c
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   1/* net/atm/clip.c - RFC1577 Classical IP over ATM */
   2
   3/* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */
   4
   5#include <linux/string.h>
   6#include <linux/errno.h>
   7#include <linux/kernel.h> /* for UINT_MAX */
   8#include <linux/module.h>
   9#include <linux/init.h>
  10#include <linux/netdevice.h>
  11#include <linux/skbuff.h>
  12#include <linux/wait.h>
  13#include <linux/timer.h>
  14#include <linux/if_arp.h> /* for some manifest constants */
  15#include <linux/notifier.h>
  16#include <linux/atm.h>
  17#include <linux/atmdev.h>
  18#include <linux/atmclip.h>
  19#include <linux/atmarp.h>
  20#include <linux/capability.h>
  21#include <linux/ip.h> /* for net/route.h */
  22#include <linux/in.h> /* for struct sockaddr_in */
  23#include <linux/if.h> /* for IFF_UP */
  24#include <linux/inetdevice.h>
  25#include <linux/bitops.h>
  26#include <linux/poison.h>
  27#include <linux/proc_fs.h>
  28#include <linux/seq_file.h>
  29#include <linux/rcupdate.h>
  30#include <linux/jhash.h>
  31#include <net/route.h> /* for struct rtable and routing */
  32#include <net/icmp.h> /* icmp_send */
  33#include <asm/param.h> /* for HZ */
  34#include <asm/byteorder.h> /* for htons etc. */
  35#include <asm/system.h> /* save/restore_flags */
  36#include <asm/uaccess.h>
  37#include <asm/atomic.h>
  38
  39#include "common.h"
  40#include "resources.h"
  41#include <net/atmclip.h>
  42
  43static struct net_device *clip_devs;
  44static struct atm_vcc *atmarpd;
  45static struct neigh_table clip_tbl;
  46static struct timer_list idle_timer;
  47
  48static int to_atmarpd(enum atmarp_ctrl_type type, int itf, __be32 ip)
  49{
  50        struct sock *sk;
  51        struct atmarp_ctrl *ctrl;
  52        struct sk_buff *skb;
  53
  54        pr_debug("to_atmarpd(%d)\n", type);
  55        if (!atmarpd)
  56                return -EUNATCH;
  57        skb = alloc_skb(sizeof(struct atmarp_ctrl),GFP_ATOMIC);
  58        if (!skb)
  59                return -ENOMEM;
  60        ctrl = (struct atmarp_ctrl *) skb_put(skb,sizeof(struct atmarp_ctrl));
  61        ctrl->type = type;
  62        ctrl->itf_num = itf;
  63        ctrl->ip = ip;
  64        atm_force_charge(atmarpd, skb->truesize);
  65
  66        sk = sk_atm(atmarpd);
  67        skb_queue_tail(&sk->sk_receive_queue, skb);
  68        sk->sk_data_ready(sk, skb->len);
  69        return 0;
  70}
  71
  72static void link_vcc(struct clip_vcc *clip_vcc, struct atmarp_entry *entry)
  73{
  74        pr_debug("link_vcc %p to entry %p (neigh %p)\n", clip_vcc, entry,
  75                entry->neigh);
  76        clip_vcc->entry = entry;
  77        clip_vcc->xoff = 0;     /* @@@ may overrun buffer by one packet */
  78        clip_vcc->next = entry->vccs;
  79        entry->vccs = clip_vcc;
  80        entry->neigh->used = jiffies;
  81}
  82
  83static void unlink_clip_vcc(struct clip_vcc *clip_vcc)
  84{
  85        struct atmarp_entry *entry = clip_vcc->entry;
  86        struct clip_vcc **walk;
  87
  88        if (!entry) {
  89                printk(KERN_CRIT "!clip_vcc->entry (clip_vcc %p)\n", clip_vcc);
  90                return;
  91        }
  92        netif_tx_lock_bh(entry->neigh->dev);    /* block clip_start_xmit() */
  93        entry->neigh->used = jiffies;
  94        for (walk = &entry->vccs; *walk; walk = &(*walk)->next)
  95                if (*walk == clip_vcc) {
  96                        int error;
  97
  98                        *walk = clip_vcc->next; /* atomic */
  99                        clip_vcc->entry = NULL;
 100                        if (clip_vcc->xoff)
 101                                netif_wake_queue(entry->neigh->dev);
 102                        if (entry->vccs)
 103                                goto out;
 104                        entry->expires = jiffies - 1;
 105                        /* force resolution or expiration */
 106                        error = neigh_update(entry->neigh, NULL, NUD_NONE,
 107                                             NEIGH_UPDATE_F_ADMIN);
 108                        if (error)
 109                                printk(KERN_CRIT "unlink_clip_vcc: "
 110                                       "neigh_update failed with %d\n", error);
 111                        goto out;
 112                }
 113        printk(KERN_CRIT "ATMARP: unlink_clip_vcc failed (entry %p, vcc "
 114               "0x%p)\n", entry, clip_vcc);
 115      out:
 116        netif_tx_unlock_bh(entry->neigh->dev);
 117}
 118
 119/* The neighbour entry n->lock is held. */
 120static int neigh_check_cb(struct neighbour *n)
 121{
 122        struct atmarp_entry *entry = NEIGH2ENTRY(n);
 123        struct clip_vcc *cv;
 124
 125        for (cv = entry->vccs; cv; cv = cv->next) {
 126                unsigned long exp = cv->last_use + cv->idle_timeout;
 127
 128                if (cv->idle_timeout && time_after(jiffies, exp)) {
 129                        pr_debug("releasing vcc %p->%p of entry %p\n",
 130                                cv, cv->vcc, entry);
 131                        vcc_release_async(cv->vcc, -ETIMEDOUT);
 132                }
 133        }
 134
 135        if (entry->vccs || time_before(jiffies, entry->expires))
 136                return 0;
 137
 138        if (atomic_read(&n->refcnt) > 1) {
 139                struct sk_buff *skb;
 140
 141                pr_debug("destruction postponed with ref %d\n",
 142                        atomic_read(&n->refcnt));
 143
 144                while ((skb = skb_dequeue(&n->arp_queue)) != NULL)
 145                        dev_kfree_skb(skb);
 146
 147                return 0;
 148        }
 149
 150        pr_debug("expired neigh %p\n", n);
 151        return 1;
 152}
 153
 154static void idle_timer_check(unsigned long dummy)
 155{
 156        write_lock(&clip_tbl.lock);
 157        __neigh_for_each_release(&clip_tbl, neigh_check_cb);
 158        mod_timer(&idle_timer, jiffies + CLIP_CHECK_INTERVAL * HZ);
 159        write_unlock(&clip_tbl.lock);
 160}
 161
 162static int clip_arp_rcv(struct sk_buff *skb)
 163{
 164        struct atm_vcc *vcc;
 165
 166        pr_debug("clip_arp_rcv\n");
 167        vcc = ATM_SKB(skb)->vcc;
 168        if (!vcc || !atm_charge(vcc, skb->truesize)) {
 169                dev_kfree_skb_any(skb);
 170                return 0;
 171        }
 172        pr_debug("pushing to %p\n", vcc);
 173        pr_debug("using %p\n", CLIP_VCC(vcc)->old_push);
 174        CLIP_VCC(vcc)->old_push(vcc, skb);
 175        return 0;
 176}
 177
 178static const unsigned char llc_oui[] = {
 179        0xaa,   /* DSAP: non-ISO */
 180        0xaa,   /* SSAP: non-ISO */
 181        0x03,   /* Ctrl: Unnumbered Information Command PDU */
 182        0x00,   /* OUI: EtherType */
 183        0x00,
 184        0x00
 185};
 186
 187static void clip_push(struct atm_vcc *vcc, struct sk_buff *skb)
 188{
 189        struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
 190
 191        pr_debug("clip push\n");
 192        if (!skb) {
 193                pr_debug("removing VCC %p\n", clip_vcc);
 194                if (clip_vcc->entry)
 195                        unlink_clip_vcc(clip_vcc);
 196                clip_vcc->old_push(vcc, NULL);  /* pass on the bad news */
 197                kfree(clip_vcc);
 198                return;
 199        }
 200        atm_return(vcc, skb->truesize);
 201        skb->dev = clip_vcc->entry ? clip_vcc->entry->neigh->dev : clip_devs;
 202        /* clip_vcc->entry == NULL if we don't have an IP address yet */
 203        if (!skb->dev) {
 204                dev_kfree_skb_any(skb);
 205                return;
 206        }
 207        ATM_SKB(skb)->vcc = vcc;
 208        skb_reset_mac_header(skb);
 209        if (!clip_vcc->encap
 210            || skb->len < RFC1483LLC_LEN
 211            || memcmp(skb->data, llc_oui, sizeof (llc_oui)))
 212                skb->protocol = htons(ETH_P_IP);
 213        else {
 214                skb->protocol = ((__be16 *) skb->data)[3];
 215                skb_pull(skb, RFC1483LLC_LEN);
 216                if (skb->protocol == htons(ETH_P_ARP)) {
 217                        PRIV(skb->dev)->stats.rx_packets++;
 218                        PRIV(skb->dev)->stats.rx_bytes += skb->len;
 219                        clip_arp_rcv(skb);
 220                        return;
 221                }
 222        }
 223        clip_vcc->last_use = jiffies;
 224        PRIV(skb->dev)->stats.rx_packets++;
 225        PRIV(skb->dev)->stats.rx_bytes += skb->len;
 226        memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
 227        netif_rx(skb);
 228}
 229
 230/*
 231 * Note: these spinlocks _must_not_ block on non-SMP. The only goal is that
 232 * clip_pop is atomic with respect to the critical section in clip_start_xmit.
 233 */
 234
 235static void clip_pop(struct atm_vcc *vcc, struct sk_buff *skb)
 236{
 237        struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
 238        struct net_device *dev = skb->dev;
 239        int old;
 240        unsigned long flags;
 241
 242        pr_debug("clip_pop(vcc %p)\n", vcc);
 243        clip_vcc->old_pop(vcc, skb);
 244        /* skb->dev == NULL in outbound ARP packets */
 245        if (!dev)
 246                return;
 247        spin_lock_irqsave(&PRIV(dev)->xoff_lock, flags);
 248        if (atm_may_send(vcc, 0)) {
 249                old = xchg(&clip_vcc->xoff, 0);
 250                if (old)
 251                        netif_wake_queue(dev);
 252        }
 253        spin_unlock_irqrestore(&PRIV(dev)->xoff_lock, flags);
 254}
 255
 256static void clip_neigh_solicit(struct neighbour *neigh, struct sk_buff *skb)
 257{
 258        pr_debug("clip_neigh_solicit (neigh %p, skb %p)\n", neigh, skb);
 259        to_atmarpd(act_need, PRIV(neigh->dev)->number, NEIGH2ENTRY(neigh)->ip);
 260}
 261
 262static void clip_neigh_error(struct neighbour *neigh, struct sk_buff *skb)
 263{
 264#ifndef CONFIG_ATM_CLIP_NO_ICMP
 265        icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
 266#endif
 267        kfree_skb(skb);
 268}
 269
 270static struct neigh_ops clip_neigh_ops = {
 271        .family =               AF_INET,
 272        .solicit =              clip_neigh_solicit,
 273        .error_report =         clip_neigh_error,
 274        .output =               dev_queue_xmit,
 275        .connected_output =     dev_queue_xmit,
 276        .hh_output =            dev_queue_xmit,
 277        .queue_xmit =           dev_queue_xmit,
 278};
 279
 280static int clip_constructor(struct neighbour *neigh)
 281{
 282        struct atmarp_entry *entry = NEIGH2ENTRY(neigh);
 283        struct net_device *dev = neigh->dev;
 284        struct in_device *in_dev;
 285        struct neigh_parms *parms;
 286
 287        pr_debug("clip_constructor (neigh %p, entry %p)\n", neigh, entry);
 288        neigh->type = inet_addr_type(&init_net, entry->ip);
 289        if (neigh->type != RTN_UNICAST)
 290                return -EINVAL;
 291
 292        rcu_read_lock();
 293        in_dev = __in_dev_get_rcu(dev);
 294        if (!in_dev) {
 295                rcu_read_unlock();
 296                return -EINVAL;
 297        }
 298
 299        parms = in_dev->arp_parms;
 300        __neigh_parms_put(neigh->parms);
 301        neigh->parms = neigh_parms_clone(parms);
 302        rcu_read_unlock();
 303
 304        neigh->ops = &clip_neigh_ops;
 305        neigh->output = neigh->nud_state & NUD_VALID ?
 306            neigh->ops->connected_output : neigh->ops->output;
 307        entry->neigh = neigh;
 308        entry->vccs = NULL;
 309        entry->expires = jiffies - 1;
 310        return 0;
 311}
 312
 313static u32 clip_hash(const void *pkey, const struct net_device *dev)
 314{
 315        return jhash_2words(*(u32 *) pkey, dev->ifindex, clip_tbl.hash_rnd);
 316}
 317
 318static struct neigh_table clip_tbl = {
 319        .family         = AF_INET,
 320        .entry_size     = sizeof(struct neighbour)+sizeof(struct atmarp_entry),
 321        .key_len        = 4,
 322        .hash           = clip_hash,
 323        .constructor    = clip_constructor,
 324        .id             = "clip_arp_cache",
 325
 326        /* parameters are copied from ARP ... */
 327        .parms = {
 328                .tbl                    = &clip_tbl,
 329                .base_reachable_time    = 30 * HZ,
 330                .retrans_time           = 1 * HZ,
 331                .gc_staletime           = 60 * HZ,
 332                .reachable_time         = 30 * HZ,
 333                .delay_probe_time       = 5 * HZ,
 334                .queue_len              = 3,
 335                .ucast_probes           = 3,
 336                .mcast_probes           = 3,
 337                .anycast_delay          = 1 * HZ,
 338                .proxy_delay            = (8 * HZ) / 10,
 339                .proxy_qlen             = 64,
 340                .locktime               = 1 * HZ,
 341        },
 342        .gc_interval    = 30 * HZ,
 343        .gc_thresh1     = 128,
 344        .gc_thresh2     = 512,
 345        .gc_thresh3     = 1024,
 346};
 347
 348/* @@@ copy bh locking from arp.c -- need to bh-enable atm code before */
 349
 350/*
 351 * We play with the resolve flag: 0 and 1 have the usual meaning, but -1 means
 352 * to allocate the neighbour entry but not to ask atmarpd for resolution. Also,
 353 * don't increment the usage count. This is used to create entries in
 354 * clip_setentry.
 355 */
 356
 357static int clip_encap(struct atm_vcc *vcc, int mode)
 358{
 359        CLIP_VCC(vcc)->encap = mode;
 360        return 0;
 361}
 362
 363static int clip_start_xmit(struct sk_buff *skb, struct net_device *dev)
 364{
 365        struct clip_priv *clip_priv = PRIV(dev);
 366        struct atmarp_entry *entry;
 367        struct atm_vcc *vcc;
 368        int old;
 369        unsigned long flags;
 370
 371        pr_debug("clip_start_xmit (skb %p)\n", skb);
 372        if (!skb->dst) {
 373                printk(KERN_ERR "clip_start_xmit: skb->dst == NULL\n");
 374                dev_kfree_skb(skb);
 375                clip_priv->stats.tx_dropped++;
 376                return 0;
 377        }
 378        if (!skb->dst->neighbour) {
 379#if 0
 380                skb->dst->neighbour = clip_find_neighbour(skb->dst, 1);
 381                if (!skb->dst->neighbour) {
 382                        dev_kfree_skb(skb);     /* lost that one */
 383                        clip_priv->stats.tx_dropped++;
 384                        return 0;
 385                }
 386#endif
 387                printk(KERN_ERR "clip_start_xmit: NO NEIGHBOUR !\n");
 388                dev_kfree_skb(skb);
 389                clip_priv->stats.tx_dropped++;
 390                return 0;
 391        }
 392        entry = NEIGH2ENTRY(skb->dst->neighbour);
 393        if (!entry->vccs) {
 394                if (time_after(jiffies, entry->expires)) {
 395                        /* should be resolved */
 396                        entry->expires = jiffies + ATMARP_RETRY_DELAY * HZ;
 397                        to_atmarpd(act_need, PRIV(dev)->number, entry->ip);
 398                }
 399                if (entry->neigh->arp_queue.qlen < ATMARP_MAX_UNRES_PACKETS)
 400                        skb_queue_tail(&entry->neigh->arp_queue, skb);
 401                else {
 402                        dev_kfree_skb(skb);
 403                        clip_priv->stats.tx_dropped++;
 404                }
 405                return 0;
 406        }
 407        pr_debug("neigh %p, vccs %p\n", entry, entry->vccs);
 408        ATM_SKB(skb)->vcc = vcc = entry->vccs->vcc;
 409        pr_debug("using neighbour %p, vcc %p\n", skb->dst->neighbour, vcc);
 410        if (entry->vccs->encap) {
 411                void *here;
 412
 413                here = skb_push(skb, RFC1483LLC_LEN);
 414                memcpy(here, llc_oui, sizeof(llc_oui));
 415                ((__be16 *) here)[3] = skb->protocol;
 416        }
 417        atomic_add(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
 418        ATM_SKB(skb)->atm_options = vcc->atm_options;
 419        entry->vccs->last_use = jiffies;
 420        pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, vcc, vcc->dev);
 421        old = xchg(&entry->vccs->xoff, 1);      /* assume XOFF ... */
 422        if (old) {
 423                printk(KERN_WARNING "clip_start_xmit: XOFF->XOFF transition\n");
 424                return 0;
 425        }
 426        clip_priv->stats.tx_packets++;
 427        clip_priv->stats.tx_bytes += skb->len;
 428        vcc->send(vcc, skb);
 429        if (atm_may_send(vcc, 0)) {
 430                entry->vccs->xoff = 0;
 431                return 0;
 432        }
 433        spin_lock_irqsave(&clip_priv->xoff_lock, flags);
 434        netif_stop_queue(dev);  /* XOFF -> throttle immediately */
 435        barrier();
 436        if (!entry->vccs->xoff)
 437                netif_start_queue(dev);
 438        /* Oh, we just raced with clip_pop. netif_start_queue should be
 439           good enough, because nothing should really be asleep because
 440           of the brief netif_stop_queue. If this isn't true or if it
 441           changes, use netif_wake_queue instead. */
 442        spin_unlock_irqrestore(&clip_priv->xoff_lock, flags);
 443        return 0;
 444}
 445
 446static struct net_device_stats *clip_get_stats(struct net_device *dev)
 447{
 448        return &PRIV(dev)->stats;
 449}
 450
 451static int clip_mkip(struct atm_vcc *vcc, int timeout)
 452{
 453        struct clip_vcc *clip_vcc;
 454        struct sk_buff *skb;
 455        struct sk_buff_head *rq;
 456        unsigned long flags;
 457
 458        if (!vcc->push)
 459                return -EBADFD;
 460        clip_vcc = kmalloc(sizeof(struct clip_vcc), GFP_KERNEL);
 461        if (!clip_vcc)
 462                return -ENOMEM;
 463        pr_debug("mkip clip_vcc %p vcc %p\n", clip_vcc, vcc);
 464        clip_vcc->vcc = vcc;
 465        vcc->user_back = clip_vcc;
 466        set_bit(ATM_VF_IS_CLIP, &vcc->flags);
 467        clip_vcc->entry = NULL;
 468        clip_vcc->xoff = 0;
 469        clip_vcc->encap = 1;
 470        clip_vcc->last_use = jiffies;
 471        clip_vcc->idle_timeout = timeout * HZ;
 472        clip_vcc->old_push = vcc->push;
 473        clip_vcc->old_pop = vcc->pop;
 474        vcc->push = clip_push;
 475        vcc->pop = clip_pop;
 476
 477        rq = &sk_atm(vcc)->sk_receive_queue;
 478
 479        spin_lock_irqsave(&rq->lock, flags);
 480        if (skb_queue_empty(rq)) {
 481                skb = NULL;
 482        } else {
 483                /* NULL terminate the list.  */
 484                rq->prev->next = NULL;
 485                skb = rq->next;
 486        }
 487        rq->prev = rq->next = (struct sk_buff *)rq;
 488        rq->qlen = 0;
 489        spin_unlock_irqrestore(&rq->lock, flags);
 490
 491        /* re-process everything received between connection setup and MKIP */
 492        while (skb) {
 493                struct sk_buff *next = skb->next;
 494
 495                skb->next = skb->prev = NULL;
 496                if (!clip_devs) {
 497                        atm_return(vcc, skb->truesize);
 498                        kfree_skb(skb);
 499                } else {
 500                        unsigned int len = skb->len;
 501
 502                        skb_get(skb);
 503                        clip_push(vcc, skb);
 504                        PRIV(skb->dev)->stats.rx_packets--;
 505                        PRIV(skb->dev)->stats.rx_bytes -= len;
 506                        kfree_skb(skb);
 507                }
 508
 509                skb = next;
 510        }
 511        return 0;
 512}
 513
 514static int clip_setentry(struct atm_vcc *vcc, __be32 ip)
 515{
 516        struct neighbour *neigh;
 517        struct atmarp_entry *entry;
 518        int error;
 519        struct clip_vcc *clip_vcc;
 520        struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, .tos = 1}} };
 521        struct rtable *rt;
 522
 523        if (vcc->push != clip_push) {
 524                printk(KERN_WARNING "clip_setentry: non-CLIP VCC\n");
 525                return -EBADF;
 526        }
 527        clip_vcc = CLIP_VCC(vcc);
 528        if (!ip) {
 529                if (!clip_vcc->entry) {
 530                        printk(KERN_ERR "hiding hidden ATMARP entry\n");
 531                        return 0;
 532                }
 533                pr_debug("setentry: remove\n");
 534                unlink_clip_vcc(clip_vcc);
 535                return 0;
 536        }
 537        error = ip_route_output_key(&init_net, &rt, &fl);
 538        if (error)
 539                return error;
 540        neigh = __neigh_lookup(&clip_tbl, &ip, rt->u.dst.dev, 1);
 541        ip_rt_put(rt);
 542        if (!neigh)
 543                return -ENOMEM;
 544        entry = NEIGH2ENTRY(neigh);
 545        if (entry != clip_vcc->entry) {
 546                if (!clip_vcc->entry)
 547                        pr_debug("setentry: add\n");
 548                else {
 549                        pr_debug("setentry: update\n");
 550                        unlink_clip_vcc(clip_vcc);
 551                }
 552                link_vcc(clip_vcc, entry);
 553        }
 554        error = neigh_update(neigh, llc_oui, NUD_PERMANENT,
 555                             NEIGH_UPDATE_F_OVERRIDE | NEIGH_UPDATE_F_ADMIN);
 556        neigh_release(neigh);
 557        return error;
 558}
 559
 560static void clip_setup(struct net_device *dev)
 561{
 562        dev->hard_start_xmit = clip_start_xmit;
 563        /* sg_xmit ... */
 564        dev->get_stats = clip_get_stats;
 565        dev->type = ARPHRD_ATM;
 566        dev->hard_header_len = RFC1483LLC_LEN;
 567        dev->mtu = RFC1626_MTU;
 568        dev->tx_queue_len = 100;        /* "normal" queue (packets) */
 569        /* When using a "real" qdisc, the qdisc determines the queue */
 570        /* length. tx_queue_len is only used for the default case, */
 571        /* without any more elaborate queuing. 100 is a reasonable */
 572        /* compromise between decent burst-tolerance and protection */
 573        /* against memory hogs. */
 574}
 575
 576static int clip_create(int number)
 577{
 578        struct net_device *dev;
 579        struct clip_priv *clip_priv;
 580        int error;
 581
 582        if (number != -1) {
 583                for (dev = clip_devs; dev; dev = PRIV(dev)->next)
 584                        if (PRIV(dev)->number == number)
 585                                return -EEXIST;
 586        } else {
 587                number = 0;
 588                for (dev = clip_devs; dev; dev = PRIV(dev)->next)
 589                        if (PRIV(dev)->number >= number)
 590                                number = PRIV(dev)->number + 1;
 591        }
 592        dev = alloc_netdev(sizeof(struct clip_priv), "", clip_setup);
 593        if (!dev)
 594                return -ENOMEM;
 595        clip_priv = PRIV(dev);
 596        sprintf(dev->name, "atm%d", number);
 597        spin_lock_init(&clip_priv->xoff_lock);
 598        clip_priv->number = number;
 599        error = register_netdev(dev);
 600        if (error) {
 601                free_netdev(dev);
 602                return error;
 603        }
 604        clip_priv->next = clip_devs;
 605        clip_devs = dev;
 606        pr_debug("registered (net:%s)\n", dev->name);
 607        return number;
 608}
 609
 610static int clip_device_event(struct notifier_block *this, unsigned long event,
 611                             void *arg)
 612{
 613        struct net_device *dev = arg;
 614
 615        if (!net_eq(dev_net(dev), &init_net))
 616                return NOTIFY_DONE;
 617
 618        if (event == NETDEV_UNREGISTER) {
 619                neigh_ifdown(&clip_tbl, dev);
 620                return NOTIFY_DONE;
 621        }
 622
 623        /* ignore non-CLIP devices */
 624        if (dev->type != ARPHRD_ATM || dev->hard_start_xmit != clip_start_xmit)
 625                return NOTIFY_DONE;
 626
 627        switch (event) {
 628        case NETDEV_UP:
 629                pr_debug("clip_device_event NETDEV_UP\n");
 630                to_atmarpd(act_up, PRIV(dev)->number, 0);
 631                break;
 632        case NETDEV_GOING_DOWN:
 633                pr_debug("clip_device_event NETDEV_DOWN\n");
 634                to_atmarpd(act_down, PRIV(dev)->number, 0);
 635                break;
 636        case NETDEV_CHANGE:
 637        case NETDEV_CHANGEMTU:
 638                pr_debug("clip_device_event NETDEV_CHANGE*\n");
 639                to_atmarpd(act_change, PRIV(dev)->number, 0);
 640                break;
 641        }
 642        return NOTIFY_DONE;
 643}
 644
 645static int clip_inet_event(struct notifier_block *this, unsigned long event,
 646                           void *ifa)
 647{
 648        struct in_device *in_dev;
 649
 650        in_dev = ((struct in_ifaddr *)ifa)->ifa_dev;
 651        /*
 652         * Transitions are of the down-change-up type, so it's sufficient to
 653         * handle the change on up.
 654         */
 655        if (event != NETDEV_UP)
 656                return NOTIFY_DONE;
 657        return clip_device_event(this, NETDEV_CHANGE, in_dev->dev);
 658}
 659
 660
 661static struct notifier_block clip_dev_notifier = {
 662        .notifier_call = clip_device_event,
 663};
 664
 665
 666
 667static struct notifier_block clip_inet_notifier = {
 668        .notifier_call = clip_inet_event,
 669};
 670
 671
 672
 673static void atmarpd_close(struct atm_vcc *vcc)
 674{
 675        pr_debug("atmarpd_close\n");
 676
 677        rtnl_lock();
 678        atmarpd = NULL;
 679        skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
 680        rtnl_unlock();
 681
 682        pr_debug("(done)\n");
 683        module_put(THIS_MODULE);
 684}
 685
 686
 687static struct atmdev_ops atmarpd_dev_ops = {
 688        .close = atmarpd_close
 689};
 690
 691
 692static struct atm_dev atmarpd_dev = {
 693        .ops =                  &atmarpd_dev_ops,
 694        .type =                 "arpd",
 695        .number =               999,
 696        .lock =                 __SPIN_LOCK_UNLOCKED(atmarpd_dev.lock)
 697};
 698
 699
 700static int atm_init_atmarp(struct atm_vcc *vcc)
 701{
 702        rtnl_lock();
 703        if (atmarpd) {
 704                rtnl_unlock();
 705                return -EADDRINUSE;
 706        }
 707
 708        mod_timer(&idle_timer, jiffies+CLIP_CHECK_INTERVAL*HZ);
 709
 710        atmarpd = vcc;
 711        set_bit(ATM_VF_META,&vcc->flags);
 712        set_bit(ATM_VF_READY,&vcc->flags);
 713            /* allow replies and avoid getting closed if signaling dies */
 714        vcc->dev = &atmarpd_dev;
 715        vcc_insert_socket(sk_atm(vcc));
 716        vcc->push = NULL;
 717        vcc->pop = NULL; /* crash */
 718        vcc->push_oam = NULL; /* crash */
 719        rtnl_unlock();
 720        return 0;
 721}
 722
 723static int clip_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 724{
 725        struct atm_vcc *vcc = ATM_SD(sock);
 726        int err = 0;
 727
 728        switch (cmd) {
 729        case SIOCMKCLIP:
 730        case ATMARPD_CTRL:
 731        case ATMARP_MKIP:
 732        case ATMARP_SETENTRY:
 733        case ATMARP_ENCAP:
 734                if (!capable(CAP_NET_ADMIN))
 735                        return -EPERM;
 736                break;
 737        default:
 738                return -ENOIOCTLCMD;
 739        }
 740
 741        switch (cmd) {
 742        case SIOCMKCLIP:
 743                err = clip_create(arg);
 744                break;
 745        case ATMARPD_CTRL:
 746                err = atm_init_atmarp(vcc);
 747                if (!err) {
 748                        sock->state = SS_CONNECTED;
 749                        __module_get(THIS_MODULE);
 750                }
 751                break;
 752        case ATMARP_MKIP:
 753                err = clip_mkip(vcc, arg);
 754                break;
 755        case ATMARP_SETENTRY:
 756                err = clip_setentry(vcc, (__force __be32)arg);
 757                break;
 758        case ATMARP_ENCAP:
 759                err = clip_encap(vcc, arg);
 760                break;
 761        }
 762        return err;
 763}
 764
 765static struct atm_ioctl clip_ioctl_ops = {
 766        .owner = THIS_MODULE,
 767        .ioctl = clip_ioctl,
 768};
 769
 770#ifdef CONFIG_PROC_FS
 771
 772static void svc_addr(struct seq_file *seq, struct sockaddr_atmsvc *addr)
 773{
 774        static int code[] = { 1, 2, 10, 6, 1, 0 };
 775        static int e164[] = { 1, 8, 4, 6, 1, 0 };
 776
 777        if (*addr->sas_addr.pub) {
 778                seq_printf(seq, "%s", addr->sas_addr.pub);
 779                if (*addr->sas_addr.prv)
 780                        seq_putc(seq, '+');
 781        } else if (!*addr->sas_addr.prv) {
 782                seq_printf(seq, "%s", "(none)");
 783                return;
 784        }
 785        if (*addr->sas_addr.prv) {
 786                unsigned char *prv = addr->sas_addr.prv;
 787                int *fields;
 788                int i, j;
 789
 790                fields = *prv == ATM_AFI_E164 ? e164 : code;
 791                for (i = 0; fields[i]; i++) {
 792                        for (j = fields[i]; j; j--)
 793                                seq_printf(seq, "%02X", *prv++);
 794                        if (fields[i + 1])
 795                                seq_putc(seq, '.');
 796                }
 797        }
 798}
 799
 800/* This means the neighbour entry has no attached VCC objects. */
 801#define SEQ_NO_VCC_TOKEN        ((void *) 2)
 802
 803static void atmarp_info(struct seq_file *seq, struct net_device *dev,
 804                        struct atmarp_entry *entry, struct clip_vcc *clip_vcc)
 805{
 806        unsigned long exp;
 807        char buf[17];
 808        int svc, llc, off;
 809
 810        svc = ((clip_vcc == SEQ_NO_VCC_TOKEN) ||
 811               (sk_atm(clip_vcc->vcc)->sk_family == AF_ATMSVC));
 812
 813        llc = ((clip_vcc == SEQ_NO_VCC_TOKEN) || clip_vcc->encap);
 814
 815        if (clip_vcc == SEQ_NO_VCC_TOKEN)
 816                exp = entry->neigh->used;
 817        else
 818                exp = clip_vcc->last_use;
 819
 820        exp = (jiffies - exp) / HZ;
 821
 822        seq_printf(seq, "%-6s%-4s%-4s%5ld ",
 823                   dev->name, svc ? "SVC" : "PVC", llc ? "LLC" : "NULL", exp);
 824
 825        off = scnprintf(buf, sizeof(buf) - 1, "%pI4",
 826                        &entry->ip);
 827        while (off < 16)
 828                buf[off++] = ' ';
 829        buf[off] = '\0';
 830        seq_printf(seq, "%s", buf);
 831
 832        if (clip_vcc == SEQ_NO_VCC_TOKEN) {
 833                if (time_before(jiffies, entry->expires))
 834                        seq_printf(seq, "(resolving)\n");
 835                else
 836                        seq_printf(seq, "(expired, ref %d)\n",
 837                                   atomic_read(&entry->neigh->refcnt));
 838        } else if (!svc) {
 839                seq_printf(seq, "%d.%d.%d\n",
 840                           clip_vcc->vcc->dev->number,
 841                           clip_vcc->vcc->vpi, clip_vcc->vcc->vci);
 842        } else {
 843                svc_addr(seq, &clip_vcc->vcc->remote);
 844                seq_putc(seq, '\n');
 845        }
 846}
 847
 848struct clip_seq_state {
 849        /* This member must be first. */
 850        struct neigh_seq_state ns;
 851
 852        /* Local to clip specific iteration. */
 853        struct clip_vcc *vcc;
 854};
 855
 856static struct clip_vcc *clip_seq_next_vcc(struct atmarp_entry *e,
 857                                          struct clip_vcc *curr)
 858{
 859        if (!curr) {
 860                curr = e->vccs;
 861                if (!curr)
 862                        return SEQ_NO_VCC_TOKEN;
 863                return curr;
 864        }
 865        if (curr == SEQ_NO_VCC_TOKEN)
 866                return NULL;
 867
 868        curr = curr->next;
 869
 870        return curr;
 871}
 872
 873static void *clip_seq_vcc_walk(struct clip_seq_state *state,
 874                               struct atmarp_entry *e, loff_t * pos)
 875{
 876        struct clip_vcc *vcc = state->vcc;
 877
 878        vcc = clip_seq_next_vcc(e, vcc);
 879        if (vcc && pos != NULL) {
 880                while (*pos) {
 881                        vcc = clip_seq_next_vcc(e, vcc);
 882                        if (!vcc)
 883                                break;
 884                        --(*pos);
 885                }
 886        }
 887        state->vcc = vcc;
 888
 889        return vcc;
 890}
 891
 892static void *clip_seq_sub_iter(struct neigh_seq_state *_state,
 893                               struct neighbour *n, loff_t * pos)
 894{
 895        struct clip_seq_state *state = (struct clip_seq_state *)_state;
 896
 897        return clip_seq_vcc_walk(state, NEIGH2ENTRY(n), pos);
 898}
 899
 900static void *clip_seq_start(struct seq_file *seq, loff_t * pos)
 901{
 902        struct clip_seq_state *state = seq->private;
 903        state->ns.neigh_sub_iter = clip_seq_sub_iter;
 904        return neigh_seq_start(seq, pos, &clip_tbl, NEIGH_SEQ_NEIGH_ONLY);
 905}
 906
 907static int clip_seq_show(struct seq_file *seq, void *v)
 908{
 909        static char atm_arp_banner[] =
 910            "IPitf TypeEncp Idle IP address      ATM address\n";
 911
 912        if (v == SEQ_START_TOKEN) {
 913                seq_puts(seq, atm_arp_banner);
 914        } else {
 915                struct clip_seq_state *state = seq->private;
 916                struct neighbour *n = v;
 917                struct clip_vcc *vcc = state->vcc;
 918
 919                atmarp_info(seq, n->dev, NEIGH2ENTRY(n), vcc);
 920        }
 921        return 0;
 922}
 923
 924static const struct seq_operations arp_seq_ops = {
 925        .start  = clip_seq_start,
 926        .next   = neigh_seq_next,
 927        .stop   = neigh_seq_stop,
 928        .show   = clip_seq_show,
 929};
 930
 931static int arp_seq_open(struct inode *inode, struct file *file)
 932{
 933        return seq_open_net(inode, file, &arp_seq_ops,
 934                            sizeof(struct clip_seq_state));
 935}
 936
 937static const struct file_operations arp_seq_fops = {
 938        .open           = arp_seq_open,
 939        .read           = seq_read,
 940        .llseek         = seq_lseek,
 941        .release        = seq_release_net,
 942        .owner          = THIS_MODULE
 943};
 944#endif
 945
 946static void atm_clip_exit_noproc(void);
 947
 948static int __init atm_clip_init(void)
 949{
 950        neigh_table_init_no_netlink(&clip_tbl);
 951
 952        clip_tbl_hook = &clip_tbl;
 953        register_atm_ioctl(&clip_ioctl_ops);
 954        register_netdevice_notifier(&clip_dev_notifier);
 955        register_inetaddr_notifier(&clip_inet_notifier);
 956
 957        setup_timer(&idle_timer, idle_timer_check, 0);
 958
 959#ifdef CONFIG_PROC_FS
 960        {
 961                struct proc_dir_entry *p;
 962
 963                p = proc_create("arp", S_IRUGO, atm_proc_root, &arp_seq_fops);
 964                if (!p) {
 965                        printk(KERN_ERR "Unable to initialize "
 966                               "/proc/net/atm/arp\n");
 967                        atm_clip_exit_noproc();
 968                        return -ENOMEM;
 969                }
 970        }
 971#endif
 972
 973        return 0;
 974}
 975
 976static void atm_clip_exit_noproc(void)
 977{
 978        struct net_device *dev, *next;
 979
 980        unregister_inetaddr_notifier(&clip_inet_notifier);
 981        unregister_netdevice_notifier(&clip_dev_notifier);
 982
 983        deregister_atm_ioctl(&clip_ioctl_ops);
 984
 985        /* First, stop the idle timer, so it stops banging
 986         * on the table.
 987         */
 988        del_timer_sync(&idle_timer);
 989
 990        /* Next, purge the table, so that the device
 991         * unregister loop below does not hang due to
 992         * device references remaining in the table.
 993         */
 994        neigh_ifdown(&clip_tbl, NULL);
 995
 996        dev = clip_devs;
 997        while (dev) {
 998                next = PRIV(dev)->next;
 999                unregister_netdev(dev);
1000                free_netdev(dev);
1001                dev = next;
1002        }
1003
1004        /* Now it is safe to fully shutdown whole table. */
1005        neigh_table_clear(&clip_tbl);
1006
1007        clip_tbl_hook = NULL;
1008}
1009
1010static void __exit atm_clip_exit(void)
1011{
1012        remove_proc_entry("arp", atm_proc_root);
1013
1014        atm_clip_exit_noproc();
1015}
1016
1017module_init(atm_clip_init);
1018module_exit(atm_clip_exit);
1019MODULE_AUTHOR("Werner Almesberger");
1020MODULE_DESCRIPTION("Classical/IP over ATM interface");
1021MODULE_LICENSE("GPL");
1022
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