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