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 <linux/param.h> /* for HZ */
  37#include <linux/uaccess.h>
  38#include <asm/byteorder.h> /* for htons etc. */
  39#include <asm/system.h> /* save/restore_flags */
  40#include <asm/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 neigh_table clip_tbl;
  49static struct timer_list idle_timer;
  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 = 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("\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("\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                        skb->dev->stats.rx_packets++;
 218                        skb->dev->stats.rx_bytes += skb->len;
 219                        clip_arp_rcv(skb);
 220                        return;
 221                }
 222        }
 223        clip_vcc->last_use = jiffies;
 224        skb->dev->stats.rx_packets++;
 225        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("(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("(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 const 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("(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 netdev_tx_t clip_start_xmit(struct sk_buff *skb,
 364                                   struct net_device *dev)
 365{
 366        struct clip_priv *clip_priv = PRIV(dev);
 367        struct atmarp_entry *entry;
 368        struct atm_vcc *vcc;
 369        int old;
 370        unsigned long flags;
 371
 372        pr_debug("(skb %p)\n", skb);
 373        if (!skb_dst(skb)) {
 374                pr_err("skb_dst(skb) == NULL\n");
 375                dev_kfree_skb(skb);
 376                dev->stats.tx_dropped++;
 377                return NETDEV_TX_OK;
 378        }
 379        if (!skb_dst(skb)->neighbour) {
 380#if 0
 381                skb_dst(skb)->neighbour = clip_find_neighbour(skb_dst(skb), 1);
 382                if (!skb_dst(skb)->neighbour) {
 383                        dev_kfree_skb(skb);     /* lost that one */
 384                        dev->stats.tx_dropped++;
 385                        return 0;
 386                }
 387#endif
 388                pr_err("NO NEIGHBOUR !\n");
 389                dev_kfree_skb(skb);
 390                dev->stats.tx_dropped++;
 391                return NETDEV_TX_OK;
 392        }
 393        entry = NEIGH2ENTRY(skb_dst(skb)->neighbour);
 394        if (!entry->vccs) {
 395                if (time_after(jiffies, entry->expires)) {
 396                        /* should be resolved */
 397                        entry->expires = jiffies + ATMARP_RETRY_DELAY * HZ;
 398                        to_atmarpd(act_need, PRIV(dev)->number, entry->ip);
 399                }
 400                if (entry->neigh->arp_queue.qlen < ATMARP_MAX_UNRES_PACKETS)
 401                        skb_queue_tail(&entry->neigh->arp_queue, skb);
 402                else {
 403                        dev_kfree_skb(skb);
 404                        dev->stats.tx_dropped++;
 405                }
 406                return NETDEV_TX_OK;
 407        }
 408        pr_debug("neigh %p, vccs %p\n", entry, entry->vccs);
 409        ATM_SKB(skb)->vcc = vcc = entry->vccs->vcc;
 410        pr_debug("using neighbour %p, vcc %p\n", skb_dst(skb)->neighbour, vcc);
 411        if (entry->vccs->encap) {
 412                void *here;
 413
 414                here = skb_push(skb, RFC1483LLC_LEN);
 415                memcpy(here, llc_oui, sizeof(llc_oui));
 416                ((__be16 *) here)[3] = skb->protocol;
 417        }
 418        atomic_add(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
 419        ATM_SKB(skb)->atm_options = vcc->atm_options;
 420        entry->vccs->last_use = jiffies;
 421        pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, vcc, vcc->dev);
 422        old = xchg(&entry->vccs->xoff, 1);      /* assume XOFF ... */
 423        if (old) {
 424                pr_warning("XOFF->XOFF transition\n");
 425                return NETDEV_TX_OK;
 426        }
 427        dev->stats.tx_packets++;
 428        dev->stats.tx_bytes += skb->len;
 429        vcc->send(vcc, skb);
 430        if (atm_may_send(vcc, 0)) {
 431                entry->vccs->xoff = 0;
 432                return NETDEV_TX_OK;
 433        }
 434        spin_lock_irqsave(&clip_priv->xoff_lock, flags);
 435        netif_stop_queue(dev);  /* XOFF -> throttle immediately */
 436        barrier();
 437        if (!entry->vccs->xoff)
 438                netif_start_queue(dev);
 439        /* Oh, we just raced with clip_pop. netif_start_queue should be
 440           good enough, because nothing should really be asleep because
 441           of the brief netif_stop_queue. If this isn't true or if it
 442           changes, use netif_wake_queue instead. */
 443        spin_unlock_irqrestore(&clip_priv->xoff_lock, flags);
 444        return NETDEV_TX_OK;
 445}
 446
 447static int clip_mkip(struct atm_vcc *vcc, int timeout)
 448{
 449        struct sk_buff_head *rq, queue;
 450        struct clip_vcc *clip_vcc;
 451        struct sk_buff *skb, *tmp;
 452        unsigned long flags;
 453
 454        if (!vcc->push)
 455                return -EBADFD;
 456        clip_vcc = kmalloc(sizeof(struct clip_vcc), GFP_KERNEL);
 457        if (!clip_vcc)
 458                return -ENOMEM;
 459        pr_debug("%p vcc %p\n", clip_vcc, vcc);
 460        clip_vcc->vcc = vcc;
 461        vcc->user_back = clip_vcc;
 462        set_bit(ATM_VF_IS_CLIP, &vcc->flags);
 463        clip_vcc->entry = NULL;
 464        clip_vcc->xoff = 0;
 465        clip_vcc->encap = 1;
 466        clip_vcc->last_use = jiffies;
 467        clip_vcc->idle_timeout = timeout * HZ;
 468        clip_vcc->old_push = vcc->push;
 469        clip_vcc->old_pop = vcc->pop;
 470        vcc->push = clip_push;
 471        vcc->pop = clip_pop;
 472
 473        __skb_queue_head_init(&queue);
 474        rq = &sk_atm(vcc)->sk_receive_queue;
 475
 476        spin_lock_irqsave(&rq->lock, flags);
 477        skb_queue_splice_init(rq, &queue);
 478        spin_unlock_irqrestore(&rq->lock, flags);
 479
 480        /* re-process everything received between connection setup and MKIP */
 481        skb_queue_walk_safe(&queue, skb, tmp) {
 482                if (!clip_devs) {
 483                        atm_return(vcc, skb->truesize);
 484                        kfree_skb(skb);
 485                } else {
 486                        struct net_device *dev = skb->dev;
 487                        unsigned int len = skb->len;
 488
 489                        skb_get(skb);
 490                        clip_push(vcc, skb);
 491                        dev->stats.rx_packets--;
 492                        dev->stats.rx_bytes -= len;
 493                        kfree_skb(skb);
 494                }
 495        }
 496        return 0;
 497}
 498
 499static int clip_setentry(struct atm_vcc *vcc, __be32 ip)
 500{
 501        struct neighbour *neigh;
 502        struct atmarp_entry *entry;
 503        int error;
 504        struct clip_vcc *clip_vcc;
 505        struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, .tos = 1}} };
 506        struct rtable *rt;
 507
 508        if (vcc->push != clip_push) {
 509                pr_warning("non-CLIP VCC\n");
 510                return -EBADF;
 511        }
 512        clip_vcc = CLIP_VCC(vcc);
 513        if (!ip) {
 514                if (!clip_vcc->entry) {
 515                        pr_err("hiding hidden ATMARP entry\n");
 516                        return 0;
 517                }
 518                pr_debug("remove\n");
 519                unlink_clip_vcc(clip_vcc);
 520                return 0;
 521        }
 522        error = ip_route_output_key(&init_net, &rt, &fl);
 523        if (error)
 524                return error;
 525        neigh = __neigh_lookup(&clip_tbl, &ip, rt->u.dst.dev, 1);
 526        ip_rt_put(rt);
 527        if (!neigh)
 528                return -ENOMEM;
 529        entry = NEIGH2ENTRY(neigh);
 530        if (entry != clip_vcc->entry) {
 531                if (!clip_vcc->entry)
 532                        pr_debug("add\n");
 533                else {
 534                        pr_debug("update\n");
 535                        unlink_clip_vcc(clip_vcc);
 536                }
 537                link_vcc(clip_vcc, entry);
 538        }
 539        error = neigh_update(neigh, llc_oui, NUD_PERMANENT,
 540                             NEIGH_UPDATE_F_OVERRIDE | NEIGH_UPDATE_F_ADMIN);
 541        neigh_release(neigh);
 542        return error;
 543}
 544
 545static const struct net_device_ops clip_netdev_ops = {
 546        .ndo_start_xmit = clip_start_xmit,
 547};
 548
 549static void clip_setup(struct net_device *dev)
 550{
 551        dev->netdev_ops = &clip_netdev_ops;
 552        dev->type = ARPHRD_ATM;
 553        dev->hard_header_len = RFC1483LLC_LEN;
 554        dev->mtu = RFC1626_MTU;
 555        dev->tx_queue_len = 100;        /* "normal" queue (packets) */
 556        /* When using a "real" qdisc, the qdisc determines the queue */
 557        /* length. tx_queue_len is only used for the default case, */
 558        /* without any more elaborate queuing. 100 is a reasonable */
 559        /* compromise between decent burst-tolerance and protection */
 560        /* against memory hogs. */
 561        dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
 562}
 563
 564static int clip_create(int number)
 565{
 566        struct net_device *dev;
 567        struct clip_priv *clip_priv;
 568        int error;
 569
 570        if (number != -1) {
 571                for (dev = clip_devs; dev; dev = PRIV(dev)->next)
 572                        if (PRIV(dev)->number == number)
 573                                return -EEXIST;
 574        } else {
 575                number = 0;
 576                for (dev = clip_devs; dev; dev = PRIV(dev)->next)
 577                        if (PRIV(dev)->number >= number)
 578                                number = PRIV(dev)->number + 1;
 579        }
 580        dev = alloc_netdev(sizeof(struct clip_priv), "", clip_setup);
 581        if (!dev)
 582                return -ENOMEM;
 583        clip_priv = PRIV(dev);
 584        sprintf(dev->name, "atm%d", number);
 585        spin_lock_init(&clip_priv->xoff_lock);
 586        clip_priv->number = number;
 587        error = register_netdev(dev);
 588        if (error) {
 589                free_netdev(dev);
 590                return error;
 591        }
 592        clip_priv->next = clip_devs;
 593        clip_devs = dev;
 594        pr_debug("registered (net:%s)\n", dev->name);
 595        return number;
 596}
 597
 598static int clip_device_event(struct notifier_block *this, unsigned long event,
 599                             void *arg)
 600{
 601        struct net_device *dev = arg;
 602
 603        if (!net_eq(dev_net(dev), &init_net))
 604                return NOTIFY_DONE;
 605
 606        if (event == NETDEV_UNREGISTER) {
 607                neigh_ifdown(&clip_tbl, dev);
 608                return NOTIFY_DONE;
 609        }
 610
 611        /* ignore non-CLIP devices */
 612        if (dev->type != ARPHRD_ATM || dev->netdev_ops != &clip_netdev_ops)
 613                return NOTIFY_DONE;
 614
 615        switch (event) {
 616        case NETDEV_UP:
 617                pr_debug("NETDEV_UP\n");
 618                to_atmarpd(act_up, PRIV(dev)->number, 0);
 619                break;
 620        case NETDEV_GOING_DOWN:
 621                pr_debug("NETDEV_DOWN\n");
 622                to_atmarpd(act_down, PRIV(dev)->number, 0);
 623                break;
 624        case NETDEV_CHANGE:
 625        case NETDEV_CHANGEMTU:
 626                pr_debug("NETDEV_CHANGE*\n");
 627                to_atmarpd(act_change, PRIV(dev)->number, 0);
 628                break;
 629        }
 630        return NOTIFY_DONE;
 631}
 632
 633static int clip_inet_event(struct notifier_block *this, unsigned long event,
 634                           void *ifa)
 635{
 636        struct in_device *in_dev;
 637
 638        in_dev = ((struct in_ifaddr *)ifa)->ifa_dev;
 639        /*
 640         * Transitions are of the down-change-up type, so it's sufficient to
 641         * handle the change on up.
 642         */
 643        if (event != NETDEV_UP)
 644                return NOTIFY_DONE;
 645        return clip_device_event(this, NETDEV_CHANGE, in_dev->dev);
 646}
 647
 648static struct notifier_block clip_dev_notifier = {
 649        .notifier_call = clip_device_event,
 650};
 651
 652
 653
 654static struct notifier_block clip_inet_notifier = {
 655        .notifier_call = clip_inet_event,
 656};
 657
 658
 659
 660static void atmarpd_close(struct atm_vcc *vcc)
 661{
 662        pr_debug("\n");
 663
 664        rtnl_lock();
 665        atmarpd = NULL;
 666        skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
 667        rtnl_unlock();
 668
 669        pr_debug("(done)\n");
 670        module_put(THIS_MODULE);
 671}
 672
 673static struct atmdev_ops atmarpd_dev_ops = {
 674        .close = atmarpd_close
 675};
 676
 677
 678static struct atm_dev atmarpd_dev = {
 679        .ops =                  &atmarpd_dev_ops,
 680        .type =                 "arpd",
 681        .number =               999,
 682        .lock =                 __SPIN_LOCK_UNLOCKED(atmarpd_dev.lock)
 683};
 684
 685
 686static int atm_init_atmarp(struct atm_vcc *vcc)
 687{
 688        rtnl_lock();
 689        if (atmarpd) {
 690                rtnl_unlock();
 691                return -EADDRINUSE;
 692        }
 693
 694        mod_timer(&idle_timer, jiffies + CLIP_CHECK_INTERVAL * HZ);
 695
 696        atmarpd = vcc;
 697        set_bit(ATM_VF_META, &vcc->flags);
 698        set_bit(ATM_VF_READY, &vcc->flags);
 699            /* allow replies and avoid getting closed if signaling dies */
 700        vcc->dev = &atmarpd_dev;
 701        vcc_insert_socket(sk_atm(vcc));
 702        vcc->push = NULL;
 703        vcc->pop = NULL; /* crash */
 704        vcc->push_oam = NULL; /* crash */
 705        rtnl_unlock();
 706        return 0;
 707}
 708
 709static int clip_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 710{
 711        struct atm_vcc *vcc = ATM_SD(sock);
 712        int err = 0;
 713
 714        switch (cmd) {
 715        case SIOCMKCLIP:
 716        case ATMARPD_CTRL:
 717        case ATMARP_MKIP:
 718        case ATMARP_SETENTRY:
 719        case ATMARP_ENCAP:
 720                if (!capable(CAP_NET_ADMIN))
 721                        return -EPERM;
 722                break;
 723        default:
 724                return -ENOIOCTLCMD;
 725        }
 726
 727        switch (cmd) {
 728        case SIOCMKCLIP:
 729                err = clip_create(arg);
 730                break;
 731        case ATMARPD_CTRL:
 732                err = atm_init_atmarp(vcc);
 733                if (!err) {
 734                        sock->state = SS_CONNECTED;
 735                        __module_get(THIS_MODULE);
 736                }
 737                break;
 738        case ATMARP_MKIP:
 739                err = clip_mkip(vcc, arg);
 740                break;
 741        case ATMARP_SETENTRY:
 742                err = clip_setentry(vcc, (__force __be32)arg);
 743                break;
 744        case ATMARP_ENCAP:
 745                err = clip_encap(vcc, arg);
 746                break;
 747        }
 748        return err;
 749}
 750
 751static struct atm_ioctl clip_ioctl_ops = {
 752        .owner = THIS_MODULE,
 753        .ioctl = clip_ioctl,
 754};
 755
 756#ifdef CONFIG_PROC_FS
 757
 758static void svc_addr(struct seq_file *seq, struct sockaddr_atmsvc *addr)
 759{
 760        static int code[] = { 1, 2, 10, 6, 1, 0 };
 761        static int e164[] = { 1, 8, 4, 6, 1, 0 };
 762
 763        if (*addr->sas_addr.pub) {
 764                seq_printf(seq, "%s", addr->sas_addr.pub);
 765                if (*addr->sas_addr.prv)
 766                        seq_putc(seq, '+');
 767        } else if (!*addr->sas_addr.prv) {
 768                seq_printf(seq, "%s", "(none)");
 769                return;
 770        }
 771        if (*addr->sas_addr.prv) {
 772                unsigned char *prv = addr->sas_addr.prv;
 773                int *fields;
 774                int i, j;
 775
 776                fields = *prv == ATM_AFI_E164 ? e164 : code;
 777                for (i = 0; fields[i]; i++) {
 778                        for (j = fields[i]; j; j--)
 779                                seq_printf(seq, "%02X", *prv++);
 780                        if (fields[i + 1])
 781                                seq_putc(seq, '.');
 782                }
 783        }
 784}
 785
 786/* This means the neighbour entry has no attached VCC objects. */
 787#define SEQ_NO_VCC_TOKEN        ((void *) 2)
 788
 789static void atmarp_info(struct seq_file *seq, struct net_device *dev,
 790                        struct atmarp_entry *entry, struct clip_vcc *clip_vcc)
 791{
 792        unsigned long exp;
 793        char buf[17];
 794        int svc, llc, off;
 795
 796        svc = ((clip_vcc == SEQ_NO_VCC_TOKEN) ||
 797               (sk_atm(clip_vcc->vcc)->sk_family == AF_ATMSVC));
 798
 799        llc = ((clip_vcc == SEQ_NO_VCC_TOKEN) || clip_vcc->encap);
 800
 801        if (clip_vcc == SEQ_NO_VCC_TOKEN)
 802                exp = entry->neigh->used;
 803        else
 804                exp = clip_vcc->last_use;
 805
 806        exp = (jiffies - exp) / HZ;
 807
 808        seq_printf(seq, "%-6s%-4s%-4s%5ld ",
 809                   dev->name, svc ? "SVC" : "PVC", llc ? "LLC" : "NULL", exp);
 810
 811        off = scnprintf(buf, sizeof(buf) - 1, "%pI4",
 812                        &entry->ip);
 813        while (off < 16)
 814                buf[off++] = ' ';
 815        buf[off] = '\0';
 816        seq_printf(seq, "%s", buf);
 817
 818        if (clip_vcc == SEQ_NO_VCC_TOKEN) {
 819                if (time_before(jiffies, entry->expires))
 820                        seq_printf(seq, "(resolving)\n");
 821                else
 822                        seq_printf(seq, "(expired, ref %d)\n",
 823                                   atomic_read(&entry->neigh->refcnt));
 824        } else if (!svc) {
 825                seq_printf(seq, "%d.%d.%d\n",
 826                           clip_vcc->vcc->dev->number,
 827                           clip_vcc->vcc->vpi, clip_vcc->vcc->vci);
 828        } else {
 829                svc_addr(seq, &clip_vcc->vcc->remote);
 830                seq_putc(seq, '\n');
 831        }
 832}
 833
 834struct clip_seq_state {
 835        /* This member must be first. */
 836        struct neigh_seq_state ns;
 837
 838        /* Local to clip specific iteration. */
 839        struct clip_vcc *vcc;
 840};
 841
 842static struct clip_vcc *clip_seq_next_vcc(struct atmarp_entry *e,
 843                                          struct clip_vcc *curr)
 844{
 845        if (!curr) {
 846                curr = e->vccs;
 847                if (!curr)
 848                        return SEQ_NO_VCC_TOKEN;
 849                return curr;
 850        }
 851        if (curr == SEQ_NO_VCC_TOKEN)
 852                return NULL;
 853
 854        curr = curr->next;
 855
 856        return curr;
 857}
 858
 859static void *clip_seq_vcc_walk(struct clip_seq_state *state,
 860                               struct atmarp_entry *e, loff_t * pos)
 861{
 862        struct clip_vcc *vcc = state->vcc;
 863
 864        vcc = clip_seq_next_vcc(e, vcc);
 865        if (vcc && pos != NULL) {
 866                while (*pos) {
 867                        vcc = clip_seq_next_vcc(e, vcc);
 868                        if (!vcc)
 869                                break;
 870                        --(*pos);
 871                }
 872        }
 873        state->vcc = vcc;
 874
 875        return vcc;
 876}
 877
 878static void *clip_seq_sub_iter(struct neigh_seq_state *_state,
 879                               struct neighbour *n, loff_t * pos)
 880{
 881        struct clip_seq_state *state = (struct clip_seq_state *)_state;
 882
 883        return clip_seq_vcc_walk(state, NEIGH2ENTRY(n), pos);
 884}
 885
 886static void *clip_seq_start(struct seq_file *seq, loff_t * pos)
 887{
 888        struct clip_seq_state *state = seq->private;
 889        state->ns.neigh_sub_iter = clip_seq_sub_iter;
 890        return neigh_seq_start(seq, pos, &clip_tbl, NEIGH_SEQ_NEIGH_ONLY);
 891}
 892
 893static int clip_seq_show(struct seq_file *seq, void *v)
 894{
 895        static char atm_arp_banner[] =
 896            "IPitf TypeEncp Idle IP address      ATM address\n";
 897
 898        if (v == SEQ_START_TOKEN) {
 899                seq_puts(seq, atm_arp_banner);
 900        } else {
 901                struct clip_seq_state *state = seq->private;
 902                struct neighbour *n = v;
 903                struct clip_vcc *vcc = state->vcc;
 904
 905                atmarp_info(seq, n->dev, NEIGH2ENTRY(n), vcc);
 906        }
 907        return 0;
 908}
 909
 910static const struct seq_operations arp_seq_ops = {
 911        .start  = clip_seq_start,
 912        .next   = neigh_seq_next,
 913        .stop   = neigh_seq_stop,
 914        .show   = clip_seq_show,
 915};
 916
 917static int arp_seq_open(struct inode *inode, struct file *file)
 918{
 919        return seq_open_net(inode, file, &arp_seq_ops,
 920                            sizeof(struct clip_seq_state));
 921}
 922
 923static const struct file_operations arp_seq_fops = {
 924        .open           = arp_seq_open,
 925        .read           = seq_read,
 926        .llseek         = seq_lseek,
 927        .release        = seq_release_net,
 928        .owner          = THIS_MODULE
 929};
 930#endif
 931
 932static void atm_clip_exit_noproc(void);
 933
 934static int __init atm_clip_init(void)
 935{
 936        neigh_table_init_no_netlink(&clip_tbl);
 937
 938        clip_tbl_hook = &clip_tbl;
 939        register_atm_ioctl(&clip_ioctl_ops);
 940        register_netdevice_notifier(&clip_dev_notifier);
 941        register_inetaddr_notifier(&clip_inet_notifier);
 942
 943        setup_timer(&idle_timer, idle_timer_check, 0);
 944
 945#ifdef CONFIG_PROC_FS
 946        {
 947                struct proc_dir_entry *p;
 948
 949                p = proc_create("arp", S_IRUGO, atm_proc_root, &arp_seq_fops);
 950                if (!p) {
 951                        pr_err("Unable to initialize /proc/net/atm/arp\n");
 952                        atm_clip_exit_noproc();
 953                        return -ENOMEM;
 954                }
 955        }
 956#endif
 957
 958        return 0;
 959}
 960
 961static void atm_clip_exit_noproc(void)
 962{
 963        struct net_device *dev, *next;
 964
 965        unregister_inetaddr_notifier(&clip_inet_notifier);
 966        unregister_netdevice_notifier(&clip_dev_notifier);
 967
 968        deregister_atm_ioctl(&clip_ioctl_ops);
 969
 970        /* First, stop the idle timer, so it stops banging
 971         * on the table.
 972         */
 973        del_timer_sync(&idle_timer);
 974
 975        /* Next, purge the table, so that the device
 976         * unregister loop below does not hang due to
 977         * device references remaining in the table.
 978         */
 979        neigh_ifdown(&clip_tbl, NULL);
 980
 981        dev = clip_devs;
 982        while (dev) {
 983                next = PRIV(dev)->next;
 984                unregister_netdev(dev);
 985                free_netdev(dev);
 986                dev = next;
 987        }
 988
 989        /* Now it is safe to fully shutdown whole table. */
 990        neigh_table_clear(&clip_tbl);
 991
 992        clip_tbl_hook = NULL;
 993}
 994
 995static void __exit atm_clip_exit(void)
 996{
 997        remove_proc_entry("arp", atm_proc_root);
 998
 999        atm_clip_exit_noproc();
1000}
1001
1002module_init(atm_clip_init);
1003module_exit(atm_clip_exit);
1004MODULE_AUTHOR("Werner Almesberger");
1005MODULE_DESCRIPTION("Classical/IP over ATM interface");
1006MODULE_LICENSE("GPL");
1007