linux/net/atm/clip.c
<<
>>
Prefs
   1// SPDX-License-Identifier: GPL-2.0-only
   2/* net/atm/clip.c - RFC1577 Classical IP over ATM */
   3
   4/* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */
   5
   6#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
   7
   8#include <linux/string.h>
   9#include <linux/errno.h>
  10#include <linux/kernel.h> /* for UINT_MAX */
  11#include <linux/module.h>
  12#include <linux/init.h>
  13#include <linux/netdevice.h>
  14#include <linux/skbuff.h>
  15#include <linux/wait.h>
  16#include <linux/timer.h>
  17#include <linux/if_arp.h> /* for some manifest constants */
  18#include <linux/notifier.h>
  19#include <linux/atm.h>
  20#include <linux/atmdev.h>
  21#include <linux/atmclip.h>
  22#include <linux/atmarp.h>
  23#include <linux/capability.h>
  24#include <linux/ip.h> /* for net/route.h */
  25#include <linux/in.h> /* for struct sockaddr_in */
  26#include <linux/if.h> /* for IFF_UP */
  27#include <linux/inetdevice.h>
  28#include <linux/bitops.h>
  29#include <linux/poison.h>
  30#include <linux/proc_fs.h>
  31#include <linux/seq_file.h>
  32#include <linux/rcupdate.h>
  33#include <linux/jhash.h>
  34#include <linux/slab.h>
  35#include <net/route.h> /* for struct rtable and routing */
  36#include <net/icmp.h> /* icmp_send */
  37#include <net/arp.h>
  38#include <linux/param.h> /* for HZ */
  39#include <linux/uaccess.h>
  40#include <asm/byteorder.h> /* for htons etc. */
  41#include <linux/atomic.h>
  42
  43#include "common.h"
  44#include "resources.h"
  45#include <net/atmclip.h>
  46
  47static struct net_device *clip_devs;
  48static struct atm_vcc *atmarpd;
  49static struct timer_list idle_timer;
  50static const struct neigh_ops clip_neigh_ops;
  51
  52static int to_atmarpd(enum atmarp_ctrl_type type, int itf, __be32 ip)
  53{
  54        struct sock *sk;
  55        struct atmarp_ctrl *ctrl;
  56        struct sk_buff *skb;
  57
  58        pr_debug("(%d)\n", type);
  59        if (!atmarpd)
  60                return -EUNATCH;
  61        skb = alloc_skb(sizeof(struct atmarp_ctrl), GFP_ATOMIC);
  62        if (!skb)
  63                return -ENOMEM;
  64        ctrl = skb_put(skb, sizeof(struct atmarp_ctrl));
  65        ctrl->type = type;
  66        ctrl->itf_num = itf;
  67        ctrl->ip = ip;
  68        atm_force_charge(atmarpd, skb->truesize);
  69
  70        sk = sk_atm(atmarpd);
  71        skb_queue_tail(&sk->sk_receive_queue, skb);
  72        sk->sk_data_ready(sk);
  73        return 0;
  74}
  75
  76static void link_vcc(struct clip_vcc *clip_vcc, struct atmarp_entry *entry)
  77{
  78        pr_debug("%p to entry %p (neigh %p)\n", clip_vcc, entry, entry->neigh);
  79        clip_vcc->entry = entry;
  80        clip_vcc->xoff = 0;     /* @@@ may overrun buffer by one packet */
  81        clip_vcc->next = entry->vccs;
  82        entry->vccs = clip_vcc;
  83        entry->neigh->used = jiffies;
  84}
  85
  86static void unlink_clip_vcc(struct clip_vcc *clip_vcc)
  87{
  88        struct atmarp_entry *entry = clip_vcc->entry;
  89        struct clip_vcc **walk;
  90
  91        if (!entry) {
  92                pr_err("!clip_vcc->entry (clip_vcc %p)\n", clip_vcc);
  93                return;
  94        }
  95        netif_tx_lock_bh(entry->neigh->dev);    /* block clip_start_xmit() */
  96        entry->neigh->used = jiffies;
  97        for (walk = &entry->vccs; *walk; walk = &(*walk)->next)
  98                if (*walk == clip_vcc) {
  99                        int error;
 100
 101                        *walk = clip_vcc->next; /* atomic */
 102                        clip_vcc->entry = NULL;
 103                        if (clip_vcc->xoff)
 104                                netif_wake_queue(entry->neigh->dev);
 105                        if (entry->vccs)
 106                                goto out;
 107                        entry->expires = jiffies - 1;
 108                        /* force resolution or expiration */
 109                        error = neigh_update(entry->neigh, NULL, NUD_NONE,
 110                                             NEIGH_UPDATE_F_ADMIN, 0);
 111                        if (error)
 112                                pr_err("neigh_update failed with %d\n", error);
 113                        goto out;
 114                }
 115        pr_err("ATMARP: failed (entry %p, vcc 0x%p)\n", entry, clip_vcc);
 116out:
 117        netif_tx_unlock_bh(entry->neigh->dev);
 118}
 119
 120/* The neighbour entry n->lock is held. */
 121static int neigh_check_cb(struct neighbour *n)
 122{
 123        struct atmarp_entry *entry = neighbour_priv(n);
 124        struct clip_vcc *cv;
 125
 126        if (n->ops != &clip_neigh_ops)
 127                return 0;
 128        for (cv = entry->vccs; cv; cv = cv->next) {
 129                unsigned long exp = cv->last_use + cv->idle_timeout;
 130
 131                if (cv->idle_timeout && time_after(jiffies, exp)) {
 132                        pr_debug("releasing vcc %p->%p of entry %p\n",
 133                                 cv, cv->vcc, entry);
 134                        vcc_release_async(cv->vcc, -ETIMEDOUT);
 135                }
 136        }
 137
 138        if (entry->vccs || time_before(jiffies, entry->expires))
 139                return 0;
 140
 141        if (refcount_read(&n->refcnt) > 1) {
 142                struct sk_buff *skb;
 143
 144                pr_debug("destruction postponed with ref %d\n",
 145                         refcount_read(&n->refcnt));
 146
 147                while ((skb = skb_dequeue(&n->arp_queue)) != NULL)
 148                        dev_kfree_skb(skb);
 149
 150                return 0;
 151        }
 152
 153        pr_debug("expired neigh %p\n", n);
 154        return 1;
 155}
 156
 157static void idle_timer_check(struct timer_list *unused)
 158{
 159        write_lock(&arp_tbl.lock);
 160        __neigh_for_each_release(&arp_tbl, neigh_check_cb);
 161        mod_timer(&idle_timer, jiffies + CLIP_CHECK_INTERVAL * HZ);
 162        write_unlock(&arp_tbl.lock);
 163}
 164
 165static int clip_arp_rcv(struct sk_buff *skb)
 166{
 167        struct atm_vcc *vcc;
 168
 169        pr_debug("\n");
 170        vcc = ATM_SKB(skb)->vcc;
 171        if (!vcc || !atm_charge(vcc, skb->truesize)) {
 172                dev_kfree_skb_any(skb);
 173                return 0;
 174        }
 175        pr_debug("pushing to %p\n", vcc);
 176        pr_debug("using %p\n", CLIP_VCC(vcc)->old_push);
 177        CLIP_VCC(vcc)->old_push(vcc, skb);
 178        return 0;
 179}
 180
 181static const unsigned char llc_oui[] = {
 182        0xaa,   /* DSAP: non-ISO */
 183        0xaa,   /* SSAP: non-ISO */
 184        0x03,   /* Ctrl: Unnumbered Information Command PDU */
 185        0x00,   /* OUI: EtherType */
 186        0x00,
 187        0x00
 188};
 189
 190static void clip_push(struct atm_vcc *vcc, struct sk_buff *skb)
 191{
 192        struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
 193
 194        pr_debug("\n");
 195
 196        if (!clip_devs) {
 197                atm_return(vcc, skb->truesize);
 198                kfree_skb(skb);
 199                return;
 200        }
 201
 202        if (!skb) {
 203                pr_debug("removing VCC %p\n", clip_vcc);
 204                if (clip_vcc->entry)
 205                        unlink_clip_vcc(clip_vcc);
 206                clip_vcc->old_push(vcc, NULL);  /* pass on the bad news */
 207                kfree(clip_vcc);
 208                return;
 209        }
 210        atm_return(vcc, skb->truesize);
 211        skb->dev = clip_vcc->entry ? clip_vcc->entry->neigh->dev : clip_devs;
 212        /* clip_vcc->entry == NULL if we don't have an IP address yet */
 213        if (!skb->dev) {
 214                dev_kfree_skb_any(skb);
 215                return;
 216        }
 217        ATM_SKB(skb)->vcc = vcc;
 218        skb_reset_mac_header(skb);
 219        if (!clip_vcc->encap ||
 220            skb->len < RFC1483LLC_LEN ||
 221            memcmp(skb->data, llc_oui, sizeof(llc_oui)))
 222                skb->protocol = htons(ETH_P_IP);
 223        else {
 224                skb->protocol = ((__be16 *)skb->data)[3];
 225                skb_pull(skb, RFC1483LLC_LEN);
 226                if (skb->protocol == htons(ETH_P_ARP)) {
 227                        skb->dev->stats.rx_packets++;
 228                        skb->dev->stats.rx_bytes += skb->len;
 229                        clip_arp_rcv(skb);
 230                        return;
 231                }
 232        }
 233        clip_vcc->last_use = jiffies;
 234        skb->dev->stats.rx_packets++;
 235        skb->dev->stats.rx_bytes += skb->len;
 236        memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
 237        netif_rx(skb);
 238}
 239
 240/*
 241 * Note: these spinlocks _must_not_ block on non-SMP. The only goal is that
 242 * clip_pop is atomic with respect to the critical section in clip_start_xmit.
 243 */
 244
 245static void clip_pop(struct atm_vcc *vcc, struct sk_buff *skb)
 246{
 247        struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
 248        struct net_device *dev = skb->dev;
 249        int old;
 250        unsigned long flags;
 251
 252        pr_debug("(vcc %p)\n", vcc);
 253        clip_vcc->old_pop(vcc, skb);
 254        /* skb->dev == NULL in outbound ARP packets */
 255        if (!dev)
 256                return;
 257        spin_lock_irqsave(&PRIV(dev)->xoff_lock, flags);
 258        if (atm_may_send(vcc, 0)) {
 259                old = xchg(&clip_vcc->xoff, 0);
 260                if (old)
 261                        netif_wake_queue(dev);
 262        }
 263        spin_unlock_irqrestore(&PRIV(dev)->xoff_lock, flags);
 264}
 265
 266static void clip_neigh_solicit(struct neighbour *neigh, struct sk_buff *skb)
 267{
 268        __be32 *ip = (__be32 *) neigh->primary_key;
 269
 270        pr_debug("(neigh %p, skb %p)\n", neigh, skb);
 271        to_atmarpd(act_need, PRIV(neigh->dev)->number, *ip);
 272}
 273
 274static void clip_neigh_error(struct neighbour *neigh, struct sk_buff *skb)
 275{
 276#ifndef CONFIG_ATM_CLIP_NO_ICMP
 277        icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
 278#endif
 279        kfree_skb(skb);
 280}
 281
 282static const struct neigh_ops clip_neigh_ops = {
 283        .family =               AF_INET,
 284        .solicit =              clip_neigh_solicit,
 285        .error_report =         clip_neigh_error,
 286        .output =               neigh_direct_output,
 287        .connected_output =     neigh_direct_output,
 288};
 289
 290static int clip_constructor(struct net_device *dev, struct neighbour *neigh)
 291{
 292        struct atmarp_entry *entry = neighbour_priv(neigh);
 293
 294        if (neigh->tbl->family != AF_INET)
 295                return -EINVAL;
 296
 297        if (neigh->type != RTN_UNICAST)
 298                return -EINVAL;
 299
 300        neigh->nud_state = NUD_NONE;
 301        neigh->ops = &clip_neigh_ops;
 302        neigh->output = neigh->ops->output;
 303        entry->neigh = neigh;
 304        entry->vccs = NULL;
 305        entry->expires = jiffies - 1;
 306
 307        return 0;
 308}
 309
 310/* @@@ copy bh locking from arp.c -- need to bh-enable atm code before */
 311
 312/*
 313 * We play with the resolve flag: 0 and 1 have the usual meaning, but -1 means
 314 * to allocate the neighbour entry but not to ask atmarpd for resolution. Also,
 315 * don't increment the usage count. This is used to create entries in
 316 * clip_setentry.
 317 */
 318
 319static int clip_encap(struct atm_vcc *vcc, int mode)
 320{
 321        if (!CLIP_VCC(vcc))
 322                return -EBADFD;
 323
 324        CLIP_VCC(vcc)->encap = mode;
 325        return 0;
 326}
 327
 328static netdev_tx_t clip_start_xmit(struct sk_buff *skb,
 329                                   struct net_device *dev)
 330{
 331        struct clip_priv *clip_priv = PRIV(dev);
 332        struct dst_entry *dst = skb_dst(skb);
 333        struct atmarp_entry *entry;
 334        struct neighbour *n;
 335        struct atm_vcc *vcc;
 336        struct rtable *rt;
 337        __be32 *daddr;
 338        int old;
 339        unsigned long flags;
 340
 341        pr_debug("(skb %p)\n", skb);
 342        if (!dst) {
 343                pr_err("skb_dst(skb) == NULL\n");
 344                dev_kfree_skb(skb);
 345                dev->stats.tx_dropped++;
 346                return NETDEV_TX_OK;
 347        }
 348        rt = (struct rtable *) dst;
 349        if (rt->rt_gw_family == AF_INET)
 350                daddr = &rt->rt_gw4;
 351        else
 352                daddr = &ip_hdr(skb)->daddr;
 353        n = dst_neigh_lookup(dst, daddr);
 354        if (!n) {
 355                pr_err("NO NEIGHBOUR !\n");
 356                dev_kfree_skb(skb);
 357                dev->stats.tx_dropped++;
 358                return NETDEV_TX_OK;
 359        }
 360        entry = neighbour_priv(n);
 361        if (!entry->vccs) {
 362                if (time_after(jiffies, entry->expires)) {
 363                        /* should be resolved */
 364                        entry->expires = jiffies + ATMARP_RETRY_DELAY * HZ;
 365                        to_atmarpd(act_need, PRIV(dev)->number, *((__be32 *)n->primary_key));
 366                }
 367                if (entry->neigh->arp_queue.qlen < ATMARP_MAX_UNRES_PACKETS)
 368                        skb_queue_tail(&entry->neigh->arp_queue, skb);
 369                else {
 370                        dev_kfree_skb(skb);
 371                        dev->stats.tx_dropped++;
 372                }
 373                goto out_release_neigh;
 374        }
 375        pr_debug("neigh %p, vccs %p\n", entry, entry->vccs);
 376        ATM_SKB(skb)->vcc = vcc = entry->vccs->vcc;
 377        pr_debug("using neighbour %p, vcc %p\n", n, vcc);
 378        if (entry->vccs->encap) {
 379                void *here;
 380
 381                here = skb_push(skb, RFC1483LLC_LEN);
 382                memcpy(here, llc_oui, sizeof(llc_oui));
 383                ((__be16 *) here)[3] = skb->protocol;
 384        }
 385        atm_account_tx(vcc, skb);
 386        entry->vccs->last_use = jiffies;
 387        pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, vcc, vcc->dev);
 388        old = xchg(&entry->vccs->xoff, 1);      /* assume XOFF ... */
 389        if (old) {
 390                pr_warn("XOFF->XOFF transition\n");
 391                goto out_release_neigh;
 392        }
 393        dev->stats.tx_packets++;
 394        dev->stats.tx_bytes += skb->len;
 395        vcc->send(vcc, skb);
 396        if (atm_may_send(vcc, 0)) {
 397                entry->vccs->xoff = 0;
 398                goto out_release_neigh;
 399        }
 400        spin_lock_irqsave(&clip_priv->xoff_lock, flags);
 401        netif_stop_queue(dev);  /* XOFF -> throttle immediately */
 402        barrier();
 403        if (!entry->vccs->xoff)
 404                netif_start_queue(dev);
 405        /* Oh, we just raced with clip_pop. netif_start_queue should be
 406           good enough, because nothing should really be asleep because
 407           of the brief netif_stop_queue. If this isn't true or if it
 408           changes, use netif_wake_queue instead. */
 409        spin_unlock_irqrestore(&clip_priv->xoff_lock, flags);
 410out_release_neigh:
 411        neigh_release(n);
 412        return NETDEV_TX_OK;
 413}
 414
 415static int clip_mkip(struct atm_vcc *vcc, int timeout)
 416{
 417        struct clip_vcc *clip_vcc;
 418
 419        if (!vcc->push)
 420                return -EBADFD;
 421        clip_vcc = kmalloc(sizeof(struct clip_vcc), GFP_KERNEL);
 422        if (!clip_vcc)
 423                return -ENOMEM;
 424        pr_debug("%p vcc %p\n", clip_vcc, vcc);
 425        clip_vcc->vcc = vcc;
 426        vcc->user_back = clip_vcc;
 427        set_bit(ATM_VF_IS_CLIP, &vcc->flags);
 428        clip_vcc->entry = NULL;
 429        clip_vcc->xoff = 0;
 430        clip_vcc->encap = 1;
 431        clip_vcc->last_use = jiffies;
 432        clip_vcc->idle_timeout = timeout * HZ;
 433        clip_vcc->old_push = vcc->push;
 434        clip_vcc->old_pop = vcc->pop;
 435        vcc->push = clip_push;
 436        vcc->pop = clip_pop;
 437
 438        /* re-process everything received between connection setup and MKIP */
 439        vcc_process_recv_queue(vcc);
 440
 441        return 0;
 442}
 443
 444static int clip_setentry(struct atm_vcc *vcc, __be32 ip)
 445{
 446        struct neighbour *neigh;
 447        struct atmarp_entry *entry;
 448        int error;
 449        struct clip_vcc *clip_vcc;
 450        struct rtable *rt;
 451
 452        if (vcc->push != clip_push) {
 453                pr_warn("non-CLIP VCC\n");
 454                return -EBADF;
 455        }
 456        clip_vcc = CLIP_VCC(vcc);
 457        if (!ip) {
 458                if (!clip_vcc->entry) {
 459                        pr_err("hiding hidden ATMARP entry\n");
 460                        return 0;
 461                }
 462                pr_debug("remove\n");
 463                unlink_clip_vcc(clip_vcc);
 464                return 0;
 465        }
 466        rt = ip_route_output(&init_net, ip, 0, 1, 0);
 467        if (IS_ERR(rt))
 468                return PTR_ERR(rt);
 469        neigh = __neigh_lookup(&arp_tbl, &ip, rt->dst.dev, 1);
 470        ip_rt_put(rt);
 471        if (!neigh)
 472                return -ENOMEM;
 473        entry = neighbour_priv(neigh);
 474        if (entry != clip_vcc->entry) {
 475                if (!clip_vcc->entry)
 476                        pr_debug("add\n");
 477                else {
 478                        pr_debug("update\n");
 479                        unlink_clip_vcc(clip_vcc);
 480                }
 481                link_vcc(clip_vcc, entry);
 482        }
 483        error = neigh_update(neigh, llc_oui, NUD_PERMANENT,
 484                             NEIGH_UPDATE_F_OVERRIDE | NEIGH_UPDATE_F_ADMIN, 0);
 485        neigh_release(neigh);
 486        return error;
 487}
 488
 489static const struct net_device_ops clip_netdev_ops = {
 490        .ndo_start_xmit         = clip_start_xmit,
 491        .ndo_neigh_construct    = clip_constructor,
 492};
 493
 494static void clip_setup(struct net_device *dev)
 495{
 496        dev->netdev_ops = &clip_netdev_ops;
 497        dev->type = ARPHRD_ATM;
 498        dev->neigh_priv_len = sizeof(struct atmarp_entry);
 499        dev->hard_header_len = RFC1483LLC_LEN;
 500        dev->mtu = RFC1626_MTU;
 501        dev->tx_queue_len = 100;        /* "normal" queue (packets) */
 502        /* When using a "real" qdisc, the qdisc determines the queue */
 503        /* length. tx_queue_len is only used for the default case, */
 504        /* without any more elaborate queuing. 100 is a reasonable */
 505        /* compromise between decent burst-tolerance and protection */
 506        /* against memory hogs. */
 507        netif_keep_dst(dev);
 508}
 509
 510static int clip_create(int number)
 511{
 512        struct net_device *dev;
 513        struct clip_priv *clip_priv;
 514        int error;
 515
 516        if (number != -1) {
 517                for (dev = clip_devs; dev; dev = PRIV(dev)->next)
 518                        if (PRIV(dev)->number == number)
 519                                return -EEXIST;
 520        } else {
 521                number = 0;
 522                for (dev = clip_devs; dev; dev = PRIV(dev)->next)
 523                        if (PRIV(dev)->number >= number)
 524                                number = PRIV(dev)->number + 1;
 525        }
 526        dev = alloc_netdev(sizeof(struct clip_priv), "", NET_NAME_UNKNOWN,
 527                           clip_setup);
 528        if (!dev)
 529                return -ENOMEM;
 530        clip_priv = PRIV(dev);
 531        sprintf(dev->name, "atm%d", number);
 532        spin_lock_init(&clip_priv->xoff_lock);
 533        clip_priv->number = number;
 534        error = register_netdev(dev);
 535        if (error) {
 536                free_netdev(dev);
 537                return error;
 538        }
 539        clip_priv->next = clip_devs;
 540        clip_devs = dev;
 541        pr_debug("registered (net:%s)\n", dev->name);
 542        return number;
 543}
 544
 545static int clip_device_event(struct notifier_block *this, unsigned long event,
 546                             void *ptr)
 547{
 548        struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 549
 550        if (!net_eq(dev_net(dev), &init_net))
 551                return NOTIFY_DONE;
 552
 553        if (event == NETDEV_UNREGISTER)
 554                return NOTIFY_DONE;
 555
 556        /* ignore non-CLIP devices */
 557        if (dev->type != ARPHRD_ATM || dev->netdev_ops != &clip_netdev_ops)
 558                return NOTIFY_DONE;
 559
 560        switch (event) {
 561        case NETDEV_UP:
 562                pr_debug("NETDEV_UP\n");
 563                to_atmarpd(act_up, PRIV(dev)->number, 0);
 564                break;
 565        case NETDEV_GOING_DOWN:
 566                pr_debug("NETDEV_DOWN\n");
 567                to_atmarpd(act_down, PRIV(dev)->number, 0);
 568                break;
 569        case NETDEV_CHANGE:
 570        case NETDEV_CHANGEMTU:
 571                pr_debug("NETDEV_CHANGE*\n");
 572                to_atmarpd(act_change, PRIV(dev)->number, 0);
 573                break;
 574        }
 575        return NOTIFY_DONE;
 576}
 577
 578static int clip_inet_event(struct notifier_block *this, unsigned long event,
 579                           void *ifa)
 580{
 581        struct in_device *in_dev;
 582        struct netdev_notifier_info info;
 583
 584        in_dev = ((struct in_ifaddr *)ifa)->ifa_dev;
 585        /*
 586         * Transitions are of the down-change-up type, so it's sufficient to
 587         * handle the change on up.
 588         */
 589        if (event != NETDEV_UP)
 590                return NOTIFY_DONE;
 591        netdev_notifier_info_init(&info, in_dev->dev);
 592        return clip_device_event(this, NETDEV_CHANGE, &info);
 593}
 594
 595static struct notifier_block clip_dev_notifier = {
 596        .notifier_call = clip_device_event,
 597};
 598
 599
 600
 601static struct notifier_block clip_inet_notifier = {
 602        .notifier_call = clip_inet_event,
 603};
 604
 605
 606
 607static void atmarpd_close(struct atm_vcc *vcc)
 608{
 609        pr_debug("\n");
 610
 611        rtnl_lock();
 612        atmarpd = NULL;
 613        skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
 614        rtnl_unlock();
 615
 616        pr_debug("(done)\n");
 617        module_put(THIS_MODULE);
 618}
 619
 620static const struct atmdev_ops atmarpd_dev_ops = {
 621        .close = atmarpd_close
 622};
 623
 624
 625static struct atm_dev atmarpd_dev = {
 626        .ops =                  &atmarpd_dev_ops,
 627        .type =                 "arpd",
 628        .number =               999,
 629        .lock =                 __SPIN_LOCK_UNLOCKED(atmarpd_dev.lock)
 630};
 631
 632
 633static int atm_init_atmarp(struct atm_vcc *vcc)
 634{
 635        rtnl_lock();
 636        if (atmarpd) {
 637                rtnl_unlock();
 638                return -EADDRINUSE;
 639        }
 640
 641        mod_timer(&idle_timer, jiffies + CLIP_CHECK_INTERVAL * HZ);
 642
 643        atmarpd = vcc;
 644        set_bit(ATM_VF_META, &vcc->flags);
 645        set_bit(ATM_VF_READY, &vcc->flags);
 646            /* allow replies and avoid getting closed if signaling dies */
 647        vcc->dev = &atmarpd_dev;
 648        vcc_insert_socket(sk_atm(vcc));
 649        vcc->push = NULL;
 650        vcc->pop = NULL; /* crash */
 651        vcc->push_oam = NULL; /* crash */
 652        rtnl_unlock();
 653        return 0;
 654}
 655
 656static int clip_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 657{
 658        struct atm_vcc *vcc = ATM_SD(sock);
 659        int err = 0;
 660
 661        switch (cmd) {
 662        case SIOCMKCLIP:
 663        case ATMARPD_CTRL:
 664        case ATMARP_MKIP:
 665        case ATMARP_SETENTRY:
 666        case ATMARP_ENCAP:
 667                if (!capable(CAP_NET_ADMIN))
 668                        return -EPERM;
 669                break;
 670        default:
 671                return -ENOIOCTLCMD;
 672        }
 673
 674        switch (cmd) {
 675        case SIOCMKCLIP:
 676                err = clip_create(arg);
 677                break;
 678        case ATMARPD_CTRL:
 679                err = atm_init_atmarp(vcc);
 680                if (!err) {
 681                        sock->state = SS_CONNECTED;
 682                        __module_get(THIS_MODULE);
 683                }
 684                break;
 685        case ATMARP_MKIP:
 686                err = clip_mkip(vcc, arg);
 687                break;
 688        case ATMARP_SETENTRY:
 689                err = clip_setentry(vcc, (__force __be32)arg);
 690                break;
 691        case ATMARP_ENCAP:
 692                err = clip_encap(vcc, arg);
 693                break;
 694        }
 695        return err;
 696}
 697
 698static struct atm_ioctl clip_ioctl_ops = {
 699        .owner = THIS_MODULE,
 700        .ioctl = clip_ioctl,
 701};
 702
 703#ifdef CONFIG_PROC_FS
 704
 705static void svc_addr(struct seq_file *seq, struct sockaddr_atmsvc *addr)
 706{
 707        static int code[] = { 1, 2, 10, 6, 1, 0 };
 708        static int e164[] = { 1, 8, 4, 6, 1, 0 };
 709
 710        if (*addr->sas_addr.pub) {
 711                seq_printf(seq, "%s", addr->sas_addr.pub);
 712                if (*addr->sas_addr.prv)
 713                        seq_putc(seq, '+');
 714        } else if (!*addr->sas_addr.prv) {
 715                seq_printf(seq, "%s", "(none)");
 716                return;
 717        }
 718        if (*addr->sas_addr.prv) {
 719                unsigned char *prv = addr->sas_addr.prv;
 720                int *fields;
 721                int i, j;
 722
 723                fields = *prv == ATM_AFI_E164 ? e164 : code;
 724                for (i = 0; fields[i]; i++) {
 725                        for (j = fields[i]; j; j--)
 726                                seq_printf(seq, "%02X", *prv++);
 727                        if (fields[i + 1])
 728                                seq_putc(seq, '.');
 729                }
 730        }
 731}
 732
 733/* This means the neighbour entry has no attached VCC objects. */
 734#define SEQ_NO_VCC_TOKEN        ((void *) 2)
 735
 736static void atmarp_info(struct seq_file *seq, struct neighbour *n,
 737                        struct atmarp_entry *entry, struct clip_vcc *clip_vcc)
 738{
 739        struct net_device *dev = n->dev;
 740        unsigned long exp;
 741        char buf[17];
 742        int svc, llc, off;
 743
 744        svc = ((clip_vcc == SEQ_NO_VCC_TOKEN) ||
 745               (sk_atm(clip_vcc->vcc)->sk_family == AF_ATMSVC));
 746
 747        llc = ((clip_vcc == SEQ_NO_VCC_TOKEN) || clip_vcc->encap);
 748
 749        if (clip_vcc == SEQ_NO_VCC_TOKEN)
 750                exp = entry->neigh->used;
 751        else
 752                exp = clip_vcc->last_use;
 753
 754        exp = (jiffies - exp) / HZ;
 755
 756        seq_printf(seq, "%-6s%-4s%-4s%5ld ",
 757                   dev->name, svc ? "SVC" : "PVC", llc ? "LLC" : "NULL", exp);
 758
 759        off = scnprintf(buf, sizeof(buf) - 1, "%pI4", n->primary_key);
 760        while (off < 16)
 761                buf[off++] = ' ';
 762        buf[off] = '\0';
 763        seq_printf(seq, "%s", buf);
 764
 765        if (clip_vcc == SEQ_NO_VCC_TOKEN) {
 766                if (time_before(jiffies, entry->expires))
 767                        seq_printf(seq, "(resolving)\n");
 768                else
 769                        seq_printf(seq, "(expired, ref %d)\n",
 770                                   refcount_read(&entry->neigh->refcnt));
 771        } else if (!svc) {
 772                seq_printf(seq, "%d.%d.%d\n",
 773                           clip_vcc->vcc->dev->number,
 774                           clip_vcc->vcc->vpi, clip_vcc->vcc->vci);
 775        } else {
 776                svc_addr(seq, &clip_vcc->vcc->remote);
 777                seq_putc(seq, '\n');
 778        }
 779}
 780
 781struct clip_seq_state {
 782        /* This member must be first. */
 783        struct neigh_seq_state ns;
 784
 785        /* Local to clip specific iteration. */
 786        struct clip_vcc *vcc;
 787};
 788
 789static struct clip_vcc *clip_seq_next_vcc(struct atmarp_entry *e,
 790                                          struct clip_vcc *curr)
 791{
 792        if (!curr) {
 793                curr = e->vccs;
 794                if (!curr)
 795                        return SEQ_NO_VCC_TOKEN;
 796                return curr;
 797        }
 798        if (curr == SEQ_NO_VCC_TOKEN)
 799                return NULL;
 800
 801        curr = curr->next;
 802
 803        return curr;
 804}
 805
 806static void *clip_seq_vcc_walk(struct clip_seq_state *state,
 807                               struct atmarp_entry *e, loff_t * pos)
 808{
 809        struct clip_vcc *vcc = state->vcc;
 810
 811        vcc = clip_seq_next_vcc(e, vcc);
 812        if (vcc && pos != NULL) {
 813                while (*pos) {
 814                        vcc = clip_seq_next_vcc(e, vcc);
 815                        if (!vcc)
 816                                break;
 817                        --(*pos);
 818                }
 819        }
 820        state->vcc = vcc;
 821
 822        return vcc;
 823}
 824
 825static void *clip_seq_sub_iter(struct neigh_seq_state *_state,
 826                               struct neighbour *n, loff_t * pos)
 827{
 828        struct clip_seq_state *state = (struct clip_seq_state *)_state;
 829
 830        if (n->dev->type != ARPHRD_ATM)
 831                return NULL;
 832
 833        return clip_seq_vcc_walk(state, neighbour_priv(n), pos);
 834}
 835
 836static void *clip_seq_start(struct seq_file *seq, loff_t * pos)
 837{
 838        struct clip_seq_state *state = seq->private;
 839        state->ns.neigh_sub_iter = clip_seq_sub_iter;
 840        return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_NEIGH_ONLY);
 841}
 842
 843static int clip_seq_show(struct seq_file *seq, void *v)
 844{
 845        static char atm_arp_banner[] =
 846            "IPitf TypeEncp Idle IP address      ATM address\n";
 847
 848        if (v == SEQ_START_TOKEN) {
 849                seq_puts(seq, atm_arp_banner);
 850        } else {
 851                struct clip_seq_state *state = seq->private;
 852                struct clip_vcc *vcc = state->vcc;
 853                struct neighbour *n = v;
 854
 855                atmarp_info(seq, n, neighbour_priv(n), vcc);
 856        }
 857        return 0;
 858}
 859
 860static const struct seq_operations arp_seq_ops = {
 861        .start  = clip_seq_start,
 862        .next   = neigh_seq_next,
 863        .stop   = neigh_seq_stop,
 864        .show   = clip_seq_show,
 865};
 866#endif
 867
 868static void atm_clip_exit_noproc(void);
 869
 870static int __init atm_clip_init(void)
 871{
 872        register_atm_ioctl(&clip_ioctl_ops);
 873        register_netdevice_notifier(&clip_dev_notifier);
 874        register_inetaddr_notifier(&clip_inet_notifier);
 875
 876        timer_setup(&idle_timer, idle_timer_check, 0);
 877
 878#ifdef CONFIG_PROC_FS
 879        {
 880                struct proc_dir_entry *p;
 881
 882                p = proc_create_net("arp", 0444, atm_proc_root, &arp_seq_ops,
 883                                sizeof(struct clip_seq_state));
 884                if (!p) {
 885                        pr_err("Unable to initialize /proc/net/atm/arp\n");
 886                        atm_clip_exit_noproc();
 887                        return -ENOMEM;
 888                }
 889        }
 890#endif
 891
 892        return 0;
 893}
 894
 895static void atm_clip_exit_noproc(void)
 896{
 897        struct net_device *dev, *next;
 898
 899        unregister_inetaddr_notifier(&clip_inet_notifier);
 900        unregister_netdevice_notifier(&clip_dev_notifier);
 901
 902        deregister_atm_ioctl(&clip_ioctl_ops);
 903
 904        /* First, stop the idle timer, so it stops banging
 905         * on the table.
 906         */
 907        del_timer_sync(&idle_timer);
 908
 909        dev = clip_devs;
 910        while (dev) {
 911                next = PRIV(dev)->next;
 912                unregister_netdev(dev);
 913                free_netdev(dev);
 914                dev = next;
 915        }
 916}
 917
 918static void __exit atm_clip_exit(void)
 919{
 920        remove_proc_entry("arp", atm_proc_root);
 921
 922        atm_clip_exit_noproc();
 923}
 924
 925module_init(atm_clip_init);
 926module_exit(atm_clip_exit);
 927MODULE_AUTHOR("Werner Almesberger");
 928MODULE_DESCRIPTION("Classical/IP over ATM interface");
 929MODULE_LICENSE("GPL");
 930