net/atm/clip.c

   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 <linux/atomic.h>
  41
  42 #include "common.h"
  43 #include "resources.h"
  44 #include <net/atmclip.h>
  45
  46 static struct net_device *clip_devs;
  47 static struct atm_vcc *atmarpd;
  48 static struct neigh_table clip_tbl;
  49 static struct timer_list idle_timer;
  50
  51 static 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
  75 static 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
  85 static 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);
 115 out:
 116         netif_tx_unlock_bh(entry->neigh->dev);
 117 }
 118
 119 /* The neighbour entry n->lock is held. */
 120 static 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
 154 static 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
 162 static 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
 178 static 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
 187 static 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
 193         if (!clip_devs) {
 194                 atm_return(vcc, skb->truesize);
 195                 kfree_skb(skb);
 196                 return;
 197         }
 198
 199         if (!skb) {
 200                 pr_debug("removing VCC %p\n", clip_vcc);
 201                 if (clip_vcc->entry)
 202                         unlink_clip_vcc(clip_vcc);
 203                 clip_vcc->old_push(vcc, NULL);  /* pass on the bad news */
 204                 kfree(clip_vcc);
 205                 return;
 206         }
 207         atm_return(vcc, skb->truesize);
 208         skb->dev = clip_vcc->entry ? clip_vcc->entry->neigh->dev : clip_devs;
 209         /* clip_vcc->entry == NULL if we don't have an IP address yet */
 210         if (!skb->dev) {
 211                 dev_kfree_skb_any(skb);
 212                 return;
 213         }
 214         ATM_SKB(skb)->vcc = vcc;
 215         skb_reset_mac_header(skb);
 216         if (!clip_vcc->encap ||
 217             skb->len < RFC1483LLC_LEN ||
 218             memcmp(skb->data, llc_oui, sizeof(llc_oui)))
 219                 skb->protocol = htons(ETH_P_IP);
 220         else {
 221                 skb->protocol = ((__be16 *)skb->data)[3];
 222                 skb_pull(skb, RFC1483LLC_LEN);
 223                 if (skb->protocol == htons(ETH_P_ARP)) {
 224                         skb->dev->stats.rx_packets++;
 225                         skb->dev->stats.rx_bytes += skb->len;
 226                         clip_arp_rcv(skb);
 227                         return;
 228                 }
 229         }
 230         clip_vcc->last_use = jiffies;
 231         skb->dev->stats.rx_packets++;
 232         skb->dev->stats.rx_bytes += skb->len;
 233         memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
 234         netif_rx(skb);
 235 }
 236
 237 /*
 238  * Note: these spinlocks _must_not_ block on non-SMP. The only goal is that
 239  * clip_pop is atomic with respect to the critical section in clip_start_xmit.
 240  */
 241
 242 static void clip_pop(struct atm_vcc *vcc, struct sk_buff *skb)
 243 {
 244         struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
 245         struct net_device *dev = skb->dev;
 246         int old;
 247         unsigned long flags;
 248
 249         pr_debug("(vcc %p)\n", vcc);
 250         clip_vcc->old_pop(vcc, skb);
 251         /* skb->dev == NULL in outbound ARP packets */
 252         if (!dev)
 253                 return;
 254         spin_lock_irqsave(&PRIV(dev)->xoff_lock, flags);
 255         if (atm_may_send(vcc, 0)) {
 256                 old = xchg(&clip_vcc->xoff, 0);
 257                 if (old)
 258                         netif_wake_queue(dev);
 259         }
 260         spin_unlock_irqrestore(&PRIV(dev)->xoff_lock, flags);
 261 }
 262
 263 static void clip_neigh_solicit(struct neighbour *neigh, struct sk_buff *skb)
 264 {
 265         pr_debug("(neigh %p, skb %p)\n", neigh, skb);
 266         to_atmarpd(act_need, PRIV(neigh->dev)->number, NEIGH2ENTRY(neigh)->ip);
 267 }
 268
 269 static void clip_neigh_error(struct neighbour *neigh, struct sk_buff *skb)
 270 {
 271 #ifndef CONFIG_ATM_CLIP_NO_ICMP
 272         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
 273 #endif
 274         kfree_skb(skb);
 275 }
 276
 277 static const struct neigh_ops clip_neigh_ops = {
 278         .family =               AF_INET,
 279         .solicit =              clip_neigh_solicit,
 280         .error_report =         clip_neigh_error,
 281         .output =               neigh_direct_output,
 282         .connected_output =     neigh_direct_output,
 283 };
 284
 285 static int clip_constructor(struct neighbour *neigh)
 286 {
 287         struct atmarp_entry *entry = NEIGH2ENTRY(neigh);
 288         struct net_device *dev = neigh->dev;
 289         struct in_device *in_dev;
 290         struct neigh_parms *parms;
 291
 292         pr_debug("(neigh %p, entry %p)\n", neigh, entry);
 293         neigh->type = inet_addr_type(&init_net, entry->ip);
 294         if (neigh->type != RTN_UNICAST)
 295                 return -EINVAL;
 296
 297         rcu_read_lock();
 298         in_dev = __in_dev_get_rcu(dev);
 299         if (!in_dev) {
 300                 rcu_read_unlock();
 301                 return -EINVAL;
 302         }
 303
 304         parms = in_dev->arp_parms;
 305         __neigh_parms_put(neigh->parms);
 306         neigh->parms = neigh_parms_clone(parms);
 307         rcu_read_unlock();
 308
 309         neigh->ops = &clip_neigh_ops;
 310         neigh->output = neigh->nud_state & NUD_VALID ?
 311             neigh->ops->connected_output : neigh->ops->output;
 312         entry->neigh = neigh;
 313         entry->vccs = NULL;
 314         entry->expires = jiffies - 1;
 315         return 0;
 316 }
 317
 318 static u32 clip_hash(const void *pkey, const struct net_device *dev, __u32 rnd)
 319 {
 320         return jhash_2words(*(u32 *) pkey, dev->ifindex, rnd);
 321 }
 322
 323 static struct neigh_table clip_tbl = {
 324         .family         = AF_INET,
 325         .key_len        = 4,
 326         .hash           = clip_hash,
 327         .constructor    = clip_constructor,
 328         .id             = "clip_arp_cache",
 329
 330         /* parameters are copied from ARP ... */
 331         .parms = {
 332                 .tbl                    = &clip_tbl,
 333                 .base_reachable_time    = 30 * HZ,
 334                 .retrans_time           = 1 * HZ,
 335                 .gc_staletime           = 60 * HZ,
 336                 .reachable_time         = 30 * HZ,
 337                 .delay_probe_time       = 5 * HZ,
 338                 .queue_len_bytes        = 64 * 1024,
 339                 .ucast_probes           = 3,
 340                 .mcast_probes           = 3,
 341                 .anycast_delay          = 1 * HZ,
 342                 .proxy_delay            = (8 * HZ) / 10,
 343                 .proxy_qlen             = 64,
 344                 .locktime               = 1 * HZ,
 345         },
 346         .gc_interval    = 30 * HZ,
 347         .gc_thresh1     = 128,
 348         .gc_thresh2     = 512,
 349         .gc_thresh3     = 1024,
 350 };
 351
 352 /* @@@ copy bh locking from arp.c -- need to bh-enable atm code before */
 353
 354 /*
 355  * We play with the resolve flag: 0 and 1 have the usual meaning, but -1 means
 356  * to allocate the neighbour entry but not to ask atmarpd for resolution. Also,
 357  * don't increment the usage count. This is used to create entries in
 358  * clip_setentry.
 359  */
 360
 361 static int clip_encap(struct atm_vcc *vcc, int mode)
 362 {
 363         CLIP_VCC(vcc)->encap = mode;
 364         return 0;
 365 }
 366
 367 static netdev_tx_t clip_start_xmit(struct sk_buff *skb,
 368                                    struct net_device *dev)
 369 {
 370         struct clip_priv *clip_priv = PRIV(dev);
 371         struct dst_entry *dst = skb_dst(skb);
 372         struct atmarp_entry *entry;
 373         struct neighbour *n;
 374         struct atm_vcc *vcc;
 375         int old;
 376         unsigned long flags;
 377
 378         pr_debug("(skb %p)\n", skb);
 379         if (!dst) {
 380                 pr_err("skb_dst(skb) == NULL\n");
 381                 dev_kfree_skb(skb);
 382                 dev->stats.tx_dropped++;
 383                 return NETDEV_TX_OK;
 384         }
 385         n = dst_get_neighbour(dst);
 386         if (!n) {
 387 #if 0
 388                 n = clip_find_neighbour(skb_dst(skb), 1);
 389                 if (!n) {
 390                         dev_kfree_skb(skb);     /* lost that one */
 391                         dev->stats.tx_dropped++;
 392                         return 0;
 393                 }
 394                 dst_set_neighbour(dst, n);
 395 #endif
 396                 pr_err("NO NEIGHBOUR !\n");
 397                 dev_kfree_skb(skb);
 398                 dev->stats.tx_dropped++;
 399                 return NETDEV_TX_OK;
 400         }
 401         entry = NEIGH2ENTRY(n);
 402         if (!entry->vccs) {
 403                 if (time_after(jiffies, entry->expires)) {
 404                         /* should be resolved */
 405                         entry->expires = jiffies + ATMARP_RETRY_DELAY * HZ;
 406                         to_atmarpd(act_need, PRIV(dev)->number, entry->ip);
 407                 }
 408                 if (entry->neigh->arp_queue.qlen < ATMARP_MAX_UNRES_PACKETS)
 409                         skb_queue_tail(&entry->neigh->arp_queue, skb);
 410                 else {
 411                         dev_kfree_skb(skb);
 412                         dev->stats.tx_dropped++;
 413                 }
 414                 return NETDEV_TX_OK;
 415         }
 416         pr_debug("neigh %p, vccs %p\n", entry, entry->vccs);
 417         ATM_SKB(skb)->vcc = vcc = entry->vccs->vcc;
 418         pr_debug("using neighbour %p, vcc %p\n", n, vcc);
 419         if (entry->vccs->encap) {
 420                 void *here;
 421
 422                 here = skb_push(skb, RFC1483LLC_LEN);
 423                 memcpy(here, llc_oui, sizeof(llc_oui));
 424                 ((__be16 *) here)[3] = skb->protocol;
 425         }
 426         atomic_add(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
 427         ATM_SKB(skb)->atm_options = vcc->atm_options;
 428         entry->vccs->last_use = jiffies;
 429         pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, vcc, vcc->dev);
 430         old = xchg(&entry->vccs->xoff, 1);      /* assume XOFF ... */
 431         if (old) {
 432                 pr_warning("XOFF->XOFF transition\n");
 433                 return NETDEV_TX_OK;
 434         }
 435         dev->stats.tx_packets++;
 436         dev->stats.tx_bytes += skb->len;
 437         vcc->send(vcc, skb);
 438         if (atm_may_send(vcc, 0)) {
 439                 entry->vccs->xoff = 0;
 440                 return NETDEV_TX_OK;
 441         }
 442         spin_lock_irqsave(&clip_priv->xoff_lock, flags);
 443         netif_stop_queue(dev);  /* XOFF -> throttle immediately */
 444         barrier();
 445         if (!entry->vccs->xoff)
 446                 netif_start_queue(dev);
 447         /* Oh, we just raced with clip_pop. netif_start_queue should be
 448            good enough, because nothing should really be asleep because
 449            of the brief netif_stop_queue. If this isn't true or if it
 450            changes, use netif_wake_queue instead. */
 451         spin_unlock_irqrestore(&clip_priv->xoff_lock, flags);
 452         return NETDEV_TX_OK;
 453 }
 454
 455 static int clip_mkip(struct atm_vcc *vcc, int timeout)
 456 {
 457         struct clip_vcc *clip_vcc;
 458
 459         if (!vcc->push)
 460                 return -EBADFD;
 461         clip_vcc = kmalloc(sizeof(struct clip_vcc), GFP_KERNEL);
 462         if (!clip_vcc)
 463                 return -ENOMEM;
 464         pr_debug("%p vcc %p\n", clip_vcc, vcc);
 465         clip_vcc->vcc = vcc;
 466         vcc->user_back = clip_vcc;
 467         set_bit(ATM_VF_IS_CLIP, &vcc->flags);
 468         clip_vcc->entry = NULL;
 469         clip_vcc->xoff = 0;
 470         clip_vcc->encap = 1;
 471         clip_vcc->last_use = jiffies;
 472         clip_vcc->idle_timeout = timeout * HZ;
 473         clip_vcc->old_push = vcc->push;
 474         clip_vcc->old_pop = vcc->pop;
 475         vcc->push = clip_push;
 476         vcc->pop = clip_pop;
 477
 478         /* re-process everything received between connection setup and MKIP */
 479         vcc_process_recv_queue(vcc);
 480
 481         return 0;
 482 }
 483
 484 static int clip_setentry(struct atm_vcc *vcc, __be32 ip)
 485 {
 486         struct neighbour *neigh;
 487         struct atmarp_entry *entry;
 488         int error;
 489         struct clip_vcc *clip_vcc;
 490         struct rtable *rt;
 491
 492         if (vcc->push != clip_push) {
 493                 pr_warning("non-CLIP VCC\n");
 494                 return -EBADF;
 495         }
 496         clip_vcc = CLIP_VCC(vcc);
 497         if (!ip) {
 498                 if (!clip_vcc->entry) {
 499                         pr_err("hiding hidden ATMARP entry\n");
 500                         return 0;
 501                 }
 502                 pr_debug("remove\n");
 503                 unlink_clip_vcc(clip_vcc);
 504                 return 0;
 505         }
 506         rt = ip_route_output(&init_net, ip, 0, 1, 0);
 507         if (IS_ERR(rt))
 508                 return PTR_ERR(rt);
 509         neigh = __neigh_lookup(&clip_tbl, &ip, rt->dst.dev, 1);
 510         ip_rt_put(rt);
 511         if (!neigh)
 512                 return -ENOMEM;
 513         entry = NEIGH2ENTRY(neigh);
 514         if (entry != clip_vcc->entry) {
 515                 if (!clip_vcc->entry)
 516                         pr_debug("add\n");
 517                 else {
 518                         pr_debug("update\n");
 519                         unlink_clip_vcc(clip_vcc);
 520                 }
 521                 link_vcc(clip_vcc, entry);
 522         }
 523         error = neigh_update(neigh, llc_oui, NUD_PERMANENT,
 524                              NEIGH_UPDATE_F_OVERRIDE | NEIGH_UPDATE_F_ADMIN);
 525         neigh_release(neigh);
 526         return error;
 527 }
 528
 529 static const struct net_device_ops clip_netdev_ops = {
 530         .ndo_start_xmit = clip_start_xmit,
 531 };
 532
 533 static void clip_setup(struct net_device *dev)
 534 {
 535         dev->netdev_ops = &clip_netdev_ops;
 536         dev->type = ARPHRD_ATM;
 537         dev->neigh_priv_len = sizeof(struct atmarp_entry);
 538         dev->hard_header_len = RFC1483LLC_LEN;
 539         dev->mtu = RFC1626_MTU;
 540         dev->tx_queue_len = 100;        /* "normal" queue (packets) */
 541         /* When using a "real" qdisc, the qdisc determines the queue */
 542         /* length. tx_queue_len is only used for the default case, */
 543         /* without any more elaborate queuing. 100 is a reasonable */
 544         /* compromise between decent burst-tolerance and protection */
 545         /* against memory hogs. */
 546         dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
 547 }
 548
 549 static int clip_create(int number)
 550 {
 551         struct net_device *dev;
 552         struct clip_priv *clip_priv;
 553         int error;
 554
 555         if (number != -1) {
 556                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
 557                         if (PRIV(dev)->number == number)
 558                                 return -EEXIST;
 559         } else {
 560                 number = 0;
 561                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
 562                         if (PRIV(dev)->number >= number)
 563                                 number = PRIV(dev)->number + 1;
 564         }
 565         dev = alloc_netdev(sizeof(struct clip_priv), "", clip_setup);
 566         if (!dev)
 567                 return -ENOMEM;
 568         clip_priv = PRIV(dev);
 569         sprintf(dev->name, "atm%d", number);
 570         spin_lock_init(&clip_priv->xoff_lock);
 571         clip_priv->number = number;
 572         error = register_netdev(dev);
 573         if (error) {
 574                 free_netdev(dev);
 575                 return error;
 576         }
 577         clip_priv->next = clip_devs;
 578         clip_devs = dev;
 579         pr_debug("registered (net:%s)\n", dev->name);
 580         return number;
 581 }
 582
 583 static int clip_device_event(struct notifier_block *this, unsigned long event,
 584                              void *arg)
 585 {
 586         struct net_device *dev = arg;
 587
 588         if (!net_eq(dev_net(dev), &init_net))
 589                 return NOTIFY_DONE;
 590
 591         if (event == NETDEV_UNREGISTER) {
 592                 neigh_ifdown(&clip_tbl, dev);
 593                 return NOTIFY_DONE;
 594         }
 595
 596         /* ignore non-CLIP devices */
 597         if (dev->type != ARPHRD_ATM || dev->netdev_ops != &clip_netdev_ops)
 598                 return NOTIFY_DONE;
 599
 600         switch (event) {
 601         case NETDEV_UP:
 602                 pr_debug("NETDEV_UP\n");
 603                 to_atmarpd(act_up, PRIV(dev)->number, 0);
 604                 break;
 605         case NETDEV_GOING_DOWN:
 606                 pr_debug("NETDEV_DOWN\n");
 607                 to_atmarpd(act_down, PRIV(dev)->number, 0);
 608                 break;
 609         case NETDEV_CHANGE:
 610         case NETDEV_CHANGEMTU:
 611                 pr_debug("NETDEV_CHANGE*\n");
 612                 to_atmarpd(act_change, PRIV(dev)->number, 0);
 613                 break;
 614         }
 615         return NOTIFY_DONE;
 616 }
 617
 618 static int clip_inet_event(struct notifier_block *this, unsigned long event,
 619                            void *ifa)
 620 {
 621         struct in_device *in_dev;
 622
 623         in_dev = ((struct in_ifaddr *)ifa)->ifa_dev;
 624         /*
 625          * Transitions are of the down-change-up type, so it's sufficient to
 626          * handle the change on up.
 627          */
 628         if (event != NETDEV_UP)
 629                 return NOTIFY_DONE;
 630         return clip_device_event(this, NETDEV_CHANGE, in_dev->dev);
 631 }
 632
 633 static struct notifier_block clip_dev_notifier = {
 634         .notifier_call = clip_device_event,
 635 };
 636
 637
 638
 639 static struct notifier_block clip_inet_notifier = {
 640         .notifier_call = clip_inet_event,
 641 };
 642
 643
 644
 645 static void atmarpd_close(struct atm_vcc *vcc)
 646 {
 647         pr_debug("\n");
 648
 649         rtnl_lock();
 650         atmarpd = NULL;
 651         skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
 652         rtnl_unlock();
 653
 654         pr_debug("(done)\n");
 655         module_put(THIS_MODULE);
 656 }
 657
 658 static struct atmdev_ops atmarpd_dev_ops = {
 659         .close = atmarpd_close
 660 };
 661
 662
 663 static struct atm_dev atmarpd_dev = {
 664         .ops =                  &atmarpd_dev_ops,
 665         .type =                 "arpd",
 666         .number =               999,
 667         .lock =                 __SPIN_LOCK_UNLOCKED(atmarpd_dev.lock)
 668 };
 669
 670
 671 static int atm_init_atmarp(struct atm_vcc *vcc)
 672 {
 673         rtnl_lock();
 674         if (atmarpd) {
 675                 rtnl_unlock();
 676                 return -EADDRINUSE;
 677         }
 678
 679         mod_timer(&idle_timer, jiffies + CLIP_CHECK_INTERVAL * HZ);
 680
 681         atmarpd = vcc;
 682         set_bit(ATM_VF_META, &vcc->flags);
 683         set_bit(ATM_VF_READY, &vcc->flags);
 684             /* allow replies and avoid getting closed if signaling dies */
 685         vcc->dev = &atmarpd_dev;
 686         vcc_insert_socket(sk_atm(vcc));
 687         vcc->push = NULL;
 688         vcc->pop = NULL; /* crash */
 689         vcc->push_oam = NULL; /* crash */
 690         rtnl_unlock();
 691         return 0;
 692 }
 693
 694 static int clip_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 695 {
 696         struct atm_vcc *vcc = ATM_SD(sock);
 697         int err = 0;
 698
 699         switch (cmd) {
 700         case SIOCMKCLIP:
 701         case ATMARPD_CTRL:
 702         case ATMARP_MKIP:
 703         case ATMARP_SETENTRY:
 704         case ATMARP_ENCAP:
 705                 if (!capable(CAP_NET_ADMIN))
 706                         return -EPERM;
 707                 break;
 708         default:
 709                 return -ENOIOCTLCMD;
 710         }
 711
 712         switch (cmd) {
 713         case SIOCMKCLIP:
 714                 err = clip_create(arg);
 715                 break;
 716         case ATMARPD_CTRL:
 717                 err = atm_init_atmarp(vcc);
 718                 if (!err) {
 719                         sock->state = SS_CONNECTED;
 720                         __module_get(THIS_MODULE);
 721                 }
 722                 break;
 723         case ATMARP_MKIP:
 724                 err = clip_mkip(vcc, arg);
 725                 break;
 726         case ATMARP_SETENTRY:
 727                 err = clip_setentry(vcc, (__force __be32)arg);
 728                 break;
 729         case ATMARP_ENCAP:
 730                 err = clip_encap(vcc, arg);
 731                 break;
 732         }
 733         return err;
 734 }
 735
 736 static struct atm_ioctl clip_ioctl_ops = {
 737         .owner = THIS_MODULE,
 738         .ioctl = clip_ioctl,
 739 };
 740
 741 #ifdef CONFIG_PROC_FS
 742
 743 static void svc_addr(struct seq_file *seq, struct sockaddr_atmsvc *addr)
 744 {
 745         static int code[] = { 1, 2, 10, 6, 1, 0 };
 746         static int e164[] = { 1, 8, 4, 6, 1, 0 };
 747
 748         if (*addr->sas_addr.pub) {
 749                 seq_printf(seq, "%s", addr->sas_addr.pub);
 750                 if (*addr->sas_addr.prv)
 751                         seq_putc(seq, '+');
 752         } else if (!*addr->sas_addr.prv) {
 753                 seq_printf(seq, "%s", "(none)");
 754                 return;
 755         }
 756         if (*addr->sas_addr.prv) {
 757                 unsigned char *prv = addr->sas_addr.prv;
 758                 int *fields;
 759                 int i, j;
 760
 761                 fields = *prv == ATM_AFI_E164 ? e164 : code;
 762                 for (i = 0; fields[i]; i++) {
 763                         for (j = fields[i]; j; j--)
 764                                 seq_printf(seq, "%02X", *prv++);
 765                         if (fields[i + 1])
 766                                 seq_putc(seq, '.');
 767                 }
 768         }
 769 }
 770
 771 /* This means the neighbour entry has no attached VCC objects. */
 772 #define SEQ_NO_VCC_TOKEN        ((void *) 2)
 773
 774 static void atmarp_info(struct seq_file *seq, struct net_device *dev,
 775                         struct atmarp_entry *entry, struct clip_vcc *clip_vcc)
 776 {
 777         unsigned long exp;
 778         char buf[17];
 779         int svc, llc, off;
 780
 781         svc = ((clip_vcc == SEQ_NO_VCC_TOKEN) ||
 782                (sk_atm(clip_vcc->vcc)->sk_family == AF_ATMSVC));
 783
 784         llc = ((clip_vcc == SEQ_NO_VCC_TOKEN) || clip_vcc->encap);
 785
 786         if (clip_vcc == SEQ_NO_VCC_TOKEN)
 787                 exp = entry->neigh->used;
 788         else
 789                 exp = clip_vcc->last_use;
 790
 791         exp = (jiffies - exp) / HZ;
 792
 793         seq_printf(seq, "%-6s%-4s%-4s%5ld ",
 794                    dev->name, svc ? "SVC" : "PVC", llc ? "LLC" : "NULL", exp);
 795
 796         off = scnprintf(buf, sizeof(buf) - 1, "%pI4",
 797                         &entry->ip);
 798         while (off < 16)
 799                 buf[off++] = ' ';
 800         buf[off] = '\0';
 801         seq_printf(seq, "%s", buf);
 802
 803         if (clip_vcc == SEQ_NO_VCC_TOKEN) {
 804                 if (time_before(jiffies, entry->expires))
 805                         seq_printf(seq, "(resolving)\n");
 806                 else
 807                         seq_printf(seq, "(expired, ref %d)\n",
 808                                    atomic_read(&entry->neigh->refcnt));
 809         } else if (!svc) {
 810                 seq_printf(seq, "%d.%d.%d\n",
 811                            clip_vcc->vcc->dev->number,
 812                            clip_vcc->vcc->vpi, clip_vcc->vcc->vci);
 813         } else {
 814                 svc_addr(seq, &clip_vcc->vcc->remote);
 815                 seq_putc(seq, '\n');
 816         }
 817 }
 818
 819 struct clip_seq_state {
 820         /* This member must be first. */
 821         struct neigh_seq_state ns;
 822
 823         /* Local to clip specific iteration. */
 824         struct clip_vcc *vcc;
 825 };
 826
 827 static struct clip_vcc *clip_seq_next_vcc(struct atmarp_entry *e,
 828                                           struct clip_vcc *curr)
 829 {
 830         if (!curr) {
 831                 curr = e->vccs;
 832                 if (!curr)
 833                         return SEQ_NO_VCC_TOKEN;
 834                 return curr;
 835         }
 836         if (curr == SEQ_NO_VCC_TOKEN)
 837                 return NULL;
 838
 839         curr = curr->next;
 840
 841         return curr;
 842 }
 843
 844 static void *clip_seq_vcc_walk(struct clip_seq_state *state,
 845                                struct atmarp_entry *e, loff_t * pos)
 846 {
 847         struct clip_vcc *vcc = state->vcc;
 848
 849         vcc = clip_seq_next_vcc(e, vcc);
 850         if (vcc && pos != NULL) {
 851                 while (*pos) {
 852                         vcc = clip_seq_next_vcc(e, vcc);
 853                         if (!vcc)
 854                                 break;
 855                         --(*pos);
 856                 }
 857         }
 858         state->vcc = vcc;
 859
 860         return vcc;
 861 }
 862
 863 static void *clip_seq_sub_iter(struct neigh_seq_state *_state,
 864                                struct neighbour *n, loff_t * pos)
 865 {
 866         struct clip_seq_state *state = (struct clip_seq_state *)_state;
 867
 868         return clip_seq_vcc_walk(state, NEIGH2ENTRY(n), pos);
 869 }
 870
 871 static void *clip_seq_start(struct seq_file *seq, loff_t * pos)
 872 {
 873         struct clip_seq_state *state = seq->private;
 874         state->ns.neigh_sub_iter = clip_seq_sub_iter;
 875         return neigh_seq_start(seq, pos, &clip_tbl, NEIGH_SEQ_NEIGH_ONLY);
 876 }
 877
 878 static int clip_seq_show(struct seq_file *seq, void *v)
 879 {
 880         static char atm_arp_banner[] =
 881             "IPitf TypeEncp Idle IP address      ATM address\n";
 882
 883         if (v == SEQ_START_TOKEN) {
 884                 seq_puts(seq, atm_arp_banner);
 885         } else {
 886                 struct clip_seq_state *state = seq->private;
 887                 struct neighbour *n = v;
 888                 struct clip_vcc *vcc = state->vcc;
 889
 890                 atmarp_info(seq, n->dev, NEIGH2ENTRY(n), vcc);
 891         }
 892         return 0;
 893 }
 894
 895 static const struct seq_operations arp_seq_ops = {
 896         .start  = clip_seq_start,
 897         .next   = neigh_seq_next,
 898         .stop   = neigh_seq_stop,
 899         .show   = clip_seq_show,
 900 };
 901
 902 static int arp_seq_open(struct inode *inode, struct file *file)
 903 {
 904         return seq_open_net(inode, file, &arp_seq_ops,
 905                             sizeof(struct clip_seq_state));
 906 }
 907
 908 static const struct file_operations arp_seq_fops = {
 909         .open           = arp_seq_open,
 910         .read           = seq_read,
 911         .llseek         = seq_lseek,
 912         .release        = seq_release_net,
 913         .owner          = THIS_MODULE
 914 };
 915 #endif
 916
 917 static void atm_clip_exit_noproc(void);
 918
 919 static int __init atm_clip_init(void)
 920 {
 921         neigh_table_init_no_netlink(&clip_tbl);
 922
 923         clip_tbl_hook = &clip_tbl;
 924         register_atm_ioctl(&clip_ioctl_ops);
 925         register_netdevice_notifier(&clip_dev_notifier);
 926         register_inetaddr_notifier(&clip_inet_notifier);
 927
 928         setup_timer(&idle_timer, idle_timer_check, 0);
 929
 930 #ifdef CONFIG_PROC_FS
 931         {
 932                 struct proc_dir_entry *p;
 933
 934                 p = proc_create("arp", S_IRUGO, atm_proc_root, &arp_seq_fops);
 935                 if (!p) {
 936                         pr_err("Unable to initialize /proc/net/atm/arp\n");
 937                         atm_clip_exit_noproc();
 938                         return -ENOMEM;
 939                 }
 940         }
 941 #endif
 942
 943         return 0;
 944 }
 945
 946 static void atm_clip_exit_noproc(void)
 947 {
 948         struct net_device *dev, *next;
 949
 950         unregister_inetaddr_notifier(&clip_inet_notifier);
 951         unregister_netdevice_notifier(&clip_dev_notifier);
 952
 953         deregister_atm_ioctl(&clip_ioctl_ops);
 954
 955         /* First, stop the idle timer, so it stops banging
 956          * on the table.
 957          */
 958         del_timer_sync(&idle_timer);
 959
 960         /* Next, purge the table, so that the device
 961          * unregister loop below does not hang due to
 962          * device references remaining in the table.
 963          */
 964         neigh_ifdown(&clip_tbl, NULL);
 965
 966         dev = clip_devs;
 967         while (dev) {
 968                 next = PRIV(dev)->next;
 969                 unregister_netdev(dev);
 970                 free_netdev(dev);
 971                 dev = next;
 972         }
 973
 974         /* Now it is safe to fully shutdown whole table. */
 975         neigh_table_clear(&clip_tbl);
 976
 977         clip_tbl_hook = NULL;
 978 }
 979
 980 static void __exit atm_clip_exit(void)
 981 {
 982         remove_proc_entry("arp", atm_proc_root);
 983
 984         atm_clip_exit_noproc();
 985 }
 986
 987 module_init(atm_clip_init);
 988 module_exit(atm_clip_exit);
 989 MODULE_AUTHOR("Werner Almesberger");
 990 MODULE_DESCRIPTION("Classical/IP over ATM interface");
 991 MODULE_LICENSE("GPL");