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