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 #include <linux/string.h>
   6 #include <linux/errno.h>
   7 #include <linux/kernel.h> /* for UINT_MAX */
   8 #include <linux/module.h>
   9 #include <linux/init.h>
  10 #include <linux/netdevice.h>
  11 #include <linux/skbuff.h>
  12 #include <linux/wait.h>
  13 #include <linux/timer.h>
  14 #include <linux/if_arp.h> /* for some manifest constants */
  15 #include <linux/notifier.h>
  16 #include <linux/atm.h>
  17 #include <linux/atmdev.h>
  18 #include <linux/atmclip.h>
  19 #include <linux/atmarp.h>
  20 #include <linux/capability.h>
  21 #include <linux/ip.h> /* for net/route.h */
  22 #include <linux/in.h> /* for struct sockaddr_in */
  23 #include <linux/if.h> /* for IFF_UP */
  24 #include <linux/inetdevice.h>
  25 #include <linux/bitops.h>
  26 #include <linux/poison.h>
  27 #include <linux/proc_fs.h>
  28 #include <linux/seq_file.h>
  29 #include <linux/rcupdate.h>
  30 #include <linux/jhash.h>
  31 #include <net/route.h> /* for struct rtable and routing */
  32 #include <net/icmp.h> /* icmp_send */
  33 #include <asm/param.h> /* for HZ */
  34 #include <asm/byteorder.h> /* for htons etc. */
  35 #include <asm/system.h> /* save/restore_flags */
  36 #include <asm/uaccess.h>
  37 #include <asm/atomic.h>
  38
  39 #include "common.h"
  40 #include "resources.h"
  41 #include <net/atmclip.h>
  42
  43
  44 #if 0
  45 #define DPRINTK(format,args...) printk(format,##args)
  46 #else
  47 #define DPRINTK(format,args...)
  48 #endif
  49
  50
  51 static struct net_device *clip_devs;
  52 static struct atm_vcc *atmarpd;
  53 static struct neigh_table clip_tbl;
  54 static struct timer_list idle_timer;
  55
  56 static int to_atmarpd(enum atmarp_ctrl_type type, int itf, __be32 ip)
  57 {
  58         struct sock *sk;
  59         struct atmarp_ctrl *ctrl;
  60         struct sk_buff *skb;
  61
  62         DPRINTK("to_atmarpd(%d)\n", type);
  63         if (!atmarpd)
  64                 return -EUNATCH;
  65         skb = alloc_skb(sizeof(struct atmarp_ctrl),GFP_ATOMIC);
  66         if (!skb)
  67                 return -ENOMEM;
  68         ctrl = (struct atmarp_ctrl *) skb_put(skb,sizeof(struct atmarp_ctrl));
  69         ctrl->type = type;
  70         ctrl->itf_num = itf;
  71         ctrl->ip = ip;
  72         atm_force_charge(atmarpd, skb->truesize);
  73
  74         sk = sk_atm(atmarpd);
  75         skb_queue_tail(&sk->sk_receive_queue, skb);
  76         sk->sk_data_ready(sk, skb->len);
  77         return 0;
  78 }
  79
  80 static void link_vcc(struct clip_vcc *clip_vcc, struct atmarp_entry *entry)
  81 {
  82         DPRINTK("link_vcc %p to entry %p (neigh %p)\n", clip_vcc, entry,
  83                 entry->neigh);
  84         clip_vcc->entry = entry;
  85         clip_vcc->xoff = 0;     /* @@@ may overrun buffer by one packet */
  86         clip_vcc->next = entry->vccs;
  87         entry->vccs = clip_vcc;
  88         entry->neigh->used = jiffies;
  89 }
  90
  91 static void unlink_clip_vcc(struct clip_vcc *clip_vcc)
  92 {
  93         struct atmarp_entry *entry = clip_vcc->entry;
  94         struct clip_vcc **walk;
  95
  96         if (!entry) {
  97                 printk(KERN_CRIT "!clip_vcc->entry (clip_vcc %p)\n", clip_vcc);
  98                 return;
  99         }
 100         netif_tx_lock_bh(entry->neigh->dev);    /* block clip_start_xmit() */
 101         entry->neigh->used = jiffies;
 102         for (walk = &entry->vccs; *walk; walk = &(*walk)->next)
 103                 if (*walk == clip_vcc) {
 104                         int error;
 105
 106                         *walk = clip_vcc->next; /* atomic */
 107                         clip_vcc->entry = NULL;
 108                         if (clip_vcc->xoff)
 109                                 netif_wake_queue(entry->neigh->dev);
 110                         if (entry->vccs)
 111                                 goto out;
 112                         entry->expires = jiffies - 1;
 113                         /* force resolution or expiration */
 114                         error = neigh_update(entry->neigh, NULL, NUD_NONE,
 115                                              NEIGH_UPDATE_F_ADMIN);
 116                         if (error)
 117                                 printk(KERN_CRIT "unlink_clip_vcc: "
 118                                        "neigh_update failed with %d\n", error);
 119                         goto out;
 120                 }
 121         printk(KERN_CRIT "ATMARP: unlink_clip_vcc failed (entry %p, vcc "
 122                "0x%p)\n", entry, clip_vcc);
 123       out:
 124         netif_tx_unlock_bh(entry->neigh->dev);
 125 }
 126
 127 /* The neighbour entry n->lock is held. */
 128 static int neigh_check_cb(struct neighbour *n)
 129 {
 130         struct atmarp_entry *entry = NEIGH2ENTRY(n);
 131         struct clip_vcc *cv;
 132
 133         for (cv = entry->vccs; cv; cv = cv->next) {
 134                 unsigned long exp = cv->last_use + cv->idle_timeout;
 135
 136                 if (cv->idle_timeout && time_after(jiffies, exp)) {
 137                         DPRINTK("releasing vcc %p->%p of entry %p\n",
 138                                 cv, cv->vcc, entry);
 139                         vcc_release_async(cv->vcc, -ETIMEDOUT);
 140                 }
 141         }
 142
 143         if (entry->vccs || time_before(jiffies, entry->expires))
 144                 return 0;
 145
 146         if (atomic_read(&n->refcnt) > 1) {
 147                 struct sk_buff *skb;
 148
 149                 DPRINTK("destruction postponed with ref %d\n",
 150                         atomic_read(&n->refcnt));
 151
 152                 while ((skb = skb_dequeue(&n->arp_queue)) != NULL)
 153                         dev_kfree_skb(skb);
 154
 155                 return 0;
 156         }
 157
 158         DPRINTK("expired neigh %p\n", n);
 159         return 1;
 160 }
 161
 162 static void idle_timer_check(unsigned long dummy)
 163 {
 164         write_lock(&clip_tbl.lock);
 165         __neigh_for_each_release(&clip_tbl, neigh_check_cb);
 166         mod_timer(&idle_timer, jiffies + CLIP_CHECK_INTERVAL * HZ);
 167         write_unlock(&clip_tbl.lock);
 168 }
 169
 170 static int clip_arp_rcv(struct sk_buff *skb)
 171 {
 172         struct atm_vcc *vcc;
 173
 174         DPRINTK("clip_arp_rcv\n");
 175         vcc = ATM_SKB(skb)->vcc;
 176         if (!vcc || !atm_charge(vcc, skb->truesize)) {
 177                 dev_kfree_skb_any(skb);
 178                 return 0;
 179         }
 180         DPRINTK("pushing to %p\n", vcc);
 181         DPRINTK("using %p\n", CLIP_VCC(vcc)->old_push);
 182         CLIP_VCC(vcc)->old_push(vcc, skb);
 183         return 0;
 184 }
 185
 186 static const unsigned char llc_oui[] = {
 187         0xaa,   /* DSAP: non-ISO */
 188         0xaa,   /* SSAP: non-ISO */
 189         0x03,   /* Ctrl: Unnumbered Information Command PDU */
 190         0x00,   /* OUI: EtherType */
 191         0x00,
 192         0x00
 193 };
 194
 195 static void clip_push(struct atm_vcc *vcc, struct sk_buff *skb)
 196 {
 197         struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
 198
 199         DPRINTK("clip push\n");
 200         if (!skb) {
 201                 DPRINTK("removing VCC %p\n", clip_vcc);
 202                 if (clip_vcc->entry)
 203                         unlink_clip_vcc(clip_vcc);
 204                 clip_vcc->old_push(vcc, NULL);  /* pass on the bad news */
 205                 kfree(clip_vcc);
 206                 return;
 207         }
 208         atm_return(vcc, skb->truesize);
 209         skb->dev = clip_vcc->entry ? clip_vcc->entry->neigh->dev : clip_devs;
 210         /* clip_vcc->entry == NULL if we don't have an IP address yet */
 211         if (!skb->dev) {
 212                 dev_kfree_skb_any(skb);
 213                 return;
 214         }
 215         ATM_SKB(skb)->vcc = vcc;
 216         skb->mac.raw = skb->data;
 217         if (!clip_vcc->encap
 218             || skb->len < RFC1483LLC_LEN
 219             || memcmp(skb->data, llc_oui, sizeof (llc_oui)))
 220                 skb->protocol = htons(ETH_P_IP);
 221         else {
 222                 skb->protocol = ((__be16 *) skb->data)[3];
 223                 skb_pull(skb, RFC1483LLC_LEN);
 224                 if (skb->protocol == htons(ETH_P_ARP)) {
 225                         PRIV(skb->dev)->stats.rx_packets++;
 226                         PRIV(skb->dev)->stats.rx_bytes += skb->len;
 227                         clip_arp_rcv(skb);
 228                         return;
 229                 }
 230         }
 231         clip_vcc->last_use = jiffies;
 232         PRIV(skb->dev)->stats.rx_packets++;
 233         PRIV(skb->dev)->stats.rx_bytes += skb->len;
 234         memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
 235         netif_rx(skb);
 236 }
 237
 238 /*
 239  * Note: these spinlocks _must_not_ block on non-SMP. The only goal is that
 240  * clip_pop is atomic with respect to the critical section in clip_start_xmit.
 241  */
 242
 243 static void clip_pop(struct atm_vcc *vcc, struct sk_buff *skb)
 244 {
 245         struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
 246         struct net_device *dev = skb->dev;
 247         int old;
 248         unsigned long flags;
 249
 250         DPRINTK("clip_pop(vcc %p)\n", vcc);
 251         clip_vcc->old_pop(vcc, skb);
 252         /* skb->dev == NULL in outbound ARP packets */
 253         if (!dev)
 254                 return;
 255         spin_lock_irqsave(&PRIV(dev)->xoff_lock, flags);
 256         if (atm_may_send(vcc, 0)) {
 257                 old = xchg(&clip_vcc->xoff, 0);
 258                 if (old)
 259                         netif_wake_queue(dev);
 260         }
 261         spin_unlock_irqrestore(&PRIV(dev)->xoff_lock, flags);
 262 }
 263
 264 static void clip_neigh_destroy(struct neighbour *neigh)
 265 {
 266         DPRINTK("clip_neigh_destroy (neigh %p)\n", neigh);
 267         if (NEIGH2ENTRY(neigh)->vccs)
 268                 printk(KERN_CRIT "clip_neigh_destroy: vccs != NULL !!!\n");
 269         NEIGH2ENTRY(neigh)->vccs = (void *) NEIGHBOR_DEAD;
 270 }
 271
 272 static void clip_neigh_solicit(struct neighbour *neigh, struct sk_buff *skb)
 273 {
 274         DPRINTK("clip_neigh_solicit (neigh %p, skb %p)\n", neigh, skb);
 275         to_atmarpd(act_need, PRIV(neigh->dev)->number, NEIGH2ENTRY(neigh)->ip);
 276 }
 277
 278 static void clip_neigh_error(struct neighbour *neigh, struct sk_buff *skb)
 279 {
 280 #ifndef CONFIG_ATM_CLIP_NO_ICMP
 281         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
 282 #endif
 283         kfree_skb(skb);
 284 }
 285
 286 static struct neigh_ops clip_neigh_ops = {
 287         .family =               AF_INET,
 288         .solicit =              clip_neigh_solicit,
 289         .error_report =         clip_neigh_error,
 290         .output =               dev_queue_xmit,
 291         .connected_output =     dev_queue_xmit,
 292         .hh_output =            dev_queue_xmit,
 293         .queue_xmit =           dev_queue_xmit,
 294 };
 295
 296 static int clip_constructor(struct neighbour *neigh)
 297 {
 298         struct atmarp_entry *entry = NEIGH2ENTRY(neigh);
 299         struct net_device *dev = neigh->dev;
 300         struct in_device *in_dev;
 301         struct neigh_parms *parms;
 302
 303         DPRINTK("clip_constructor (neigh %p, entry %p)\n", neigh, entry);
 304         neigh->type = inet_addr_type(entry->ip);
 305         if (neigh->type != RTN_UNICAST)
 306                 return -EINVAL;
 307
 308         rcu_read_lock();
 309         in_dev = __in_dev_get_rcu(dev);
 310         if (!in_dev) {
 311                 rcu_read_unlock();
 312                 return -EINVAL;
 313         }
 314
 315         parms = in_dev->arp_parms;
 316         __neigh_parms_put(neigh->parms);
 317         neigh->parms = neigh_parms_clone(parms);
 318         rcu_read_unlock();
 319
 320         neigh->ops = &clip_neigh_ops;
 321         neigh->output = neigh->nud_state & NUD_VALID ?
 322             neigh->ops->connected_output : neigh->ops->output;
 323         entry->neigh = neigh;
 324         entry->vccs = NULL;
 325         entry->expires = jiffies - 1;
 326         return 0;
 327 }
 328
 329 static u32 clip_hash(const void *pkey, const struct net_device *dev)
 330 {
 331         return jhash_2words(*(u32 *) pkey, dev->ifindex, clip_tbl.hash_rnd);
 332 }
 333
 334 static struct neigh_table clip_tbl = {
 335         .family         = AF_INET,
 336         .entry_size     = sizeof(struct neighbour)+sizeof(struct atmarp_entry),
 337         .key_len        = 4,
 338         .hash           = clip_hash,
 339         .constructor    = clip_constructor,
 340         .id             = "clip_arp_cache",
 341
 342         /* parameters are copied from ARP ... */
 343         .parms = {
 344                 .tbl                    = &clip_tbl,
 345                 .neigh_destructor       = clip_neigh_destroy,
 346                 .base_reachable_time    = 30 * HZ,
 347                 .retrans_time           = 1 * HZ,
 348                 .gc_staletime           = 60 * HZ,
 349                 .reachable_time         = 30 * HZ,
 350                 .delay_probe_time       = 5 * HZ,
 351                 .queue_len              = 3,
 352                 .ucast_probes           = 3,
 353                 .mcast_probes           = 3,
 354                 .anycast_delay          = 1 * HZ,
 355                 .proxy_delay            = (8 * HZ) / 10,
 356                 .proxy_qlen             = 64,
 357                 .locktime               = 1 * HZ,
 358         },
 359         .gc_interval    = 30 * HZ,
 360         .gc_thresh1     = 128,
 361         .gc_thresh2     = 512,
 362         .gc_thresh3     = 1024,
 363 };
 364
 365 /* @@@ copy bh locking from arp.c -- need to bh-enable atm code before */
 366
 367 /*
 368  * We play with the resolve flag: 0 and 1 have the usual meaning, but -1 means
 369  * to allocate the neighbour entry but not to ask atmarpd for resolution. Also,
 370  * don't increment the usage count. This is used to create entries in
 371  * clip_setentry.
 372  */
 373
 374 static int clip_encap(struct atm_vcc *vcc, int mode)
 375 {
 376         CLIP_VCC(vcc)->encap = mode;
 377         return 0;
 378 }
 379
 380 static int clip_start_xmit(struct sk_buff *skb, struct net_device *dev)
 381 {
 382         struct clip_priv *clip_priv = PRIV(dev);
 383         struct atmarp_entry *entry;
 384         struct atm_vcc *vcc;
 385         int old;
 386         unsigned long flags;
 387
 388         DPRINTK("clip_start_xmit (skb %p)\n", skb);
 389         if (!skb->dst) {
 390                 printk(KERN_ERR "clip_start_xmit: skb->dst == NULL\n");
 391                 dev_kfree_skb(skb);
 392                 clip_priv->stats.tx_dropped++;
 393                 return 0;
 394         }
 395         if (!skb->dst->neighbour) {
 396 #if 0
 397                 skb->dst->neighbour = clip_find_neighbour(skb->dst, 1);
 398                 if (!skb->dst->neighbour) {
 399                         dev_kfree_skb(skb);     /* lost that one */
 400                         clip_priv->stats.tx_dropped++;
 401                         return 0;
 402                 }
 403 #endif
 404                 printk(KERN_ERR "clip_start_xmit: NO NEIGHBOUR !\n");
 405                 dev_kfree_skb(skb);
 406                 clip_priv->stats.tx_dropped++;
 407                 return 0;
 408         }
 409         entry = NEIGH2ENTRY(skb->dst->neighbour);
 410         if (!entry->vccs) {
 411                 if (time_after(jiffies, entry->expires)) {
 412                         /* should be resolved */
 413                         entry->expires = jiffies + ATMARP_RETRY_DELAY * HZ;
 414                         to_atmarpd(act_need, PRIV(dev)->number, entry->ip);
 415                 }
 416                 if (entry->neigh->arp_queue.qlen < ATMARP_MAX_UNRES_PACKETS)
 417                         skb_queue_tail(&entry->neigh->arp_queue, skb);
 418                 else {
 419                         dev_kfree_skb(skb);
 420                         clip_priv->stats.tx_dropped++;
 421                 }
 422                 return 0;
 423         }
 424         DPRINTK("neigh %p, vccs %p\n", entry, entry->vccs);
 425         ATM_SKB(skb)->vcc = vcc = entry->vccs->vcc;
 426         DPRINTK("using neighbour %p, vcc %p\n", skb->dst->neighbour, vcc);
 427         if (entry->vccs->encap) {
 428                 void *here;
 429
 430                 here = skb_push(skb, RFC1483LLC_LEN);
 431                 memcpy(here, llc_oui, sizeof(llc_oui));
 432                 ((__be16 *) here)[3] = skb->protocol;
 433         }
 434         atomic_add(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
 435         ATM_SKB(skb)->atm_options = vcc->atm_options;
 436         entry->vccs->last_use = jiffies;
 437         DPRINTK("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, vcc, vcc->dev);
 438         old = xchg(&entry->vccs->xoff, 1);      /* assume XOFF ... */
 439         if (old) {
 440                 printk(KERN_WARNING "clip_start_xmit: XOFF->XOFF transition\n");
 441                 return 0;
 442         }
 443         clip_priv->stats.tx_packets++;
 444         clip_priv->stats.tx_bytes += skb->len;
 445         vcc->send(vcc, skb);
 446         if (atm_may_send(vcc, 0)) {
 447                 entry->vccs->xoff = 0;
 448                 return 0;
 449         }
 450         spin_lock_irqsave(&clip_priv->xoff_lock, flags);
 451         netif_stop_queue(dev);  /* XOFF -> throttle immediately */
 452         barrier();
 453         if (!entry->vccs->xoff)
 454                 netif_start_queue(dev);
 455         /* Oh, we just raced with clip_pop. netif_start_queue should be
 456            good enough, because nothing should really be asleep because
 457            of the brief netif_stop_queue. If this isn't true or if it
 458            changes, use netif_wake_queue instead. */
 459         spin_unlock_irqrestore(&clip_priv->xoff_lock, flags);
 460         return 0;
 461 }
 462
 463 static struct net_device_stats *clip_get_stats(struct net_device *dev)
 464 {
 465         return &PRIV(dev)->stats;
 466 }
 467
 468 static int clip_mkip(struct atm_vcc *vcc, int timeout)
 469 {
 470         struct clip_vcc *clip_vcc;
 471         struct sk_buff *skb;
 472         struct sk_buff_head *rq;
 473         unsigned long flags;
 474
 475         if (!vcc->push)
 476                 return -EBADFD;
 477         clip_vcc = kmalloc(sizeof(struct clip_vcc), GFP_KERNEL);
 478         if (!clip_vcc)
 479                 return -ENOMEM;
 480         DPRINTK("mkip clip_vcc %p vcc %p\n", clip_vcc, vcc);
 481         clip_vcc->vcc = vcc;
 482         vcc->user_back = clip_vcc;
 483         set_bit(ATM_VF_IS_CLIP, &vcc->flags);
 484         clip_vcc->entry = NULL;
 485         clip_vcc->xoff = 0;
 486         clip_vcc->encap = 1;
 487         clip_vcc->last_use = jiffies;
 488         clip_vcc->idle_timeout = timeout * HZ;
 489         clip_vcc->old_push = vcc->push;
 490         clip_vcc->old_pop = vcc->pop;
 491         vcc->push = clip_push;
 492         vcc->pop = clip_pop;
 493
 494         rq = &sk_atm(vcc)->sk_receive_queue;
 495
 496         spin_lock_irqsave(&rq->lock, flags);
 497         if (skb_queue_empty(rq)) {
 498                 skb = NULL;
 499         } else {
 500                 /* NULL terminate the list.  */
 501                 rq->prev->next = NULL;
 502                 skb = rq->next;
 503         }
 504         rq->prev = rq->next = (struct sk_buff *)rq;
 505         rq->qlen = 0;
 506         spin_unlock_irqrestore(&rq->lock, flags);
 507
 508         /* re-process everything received between connection setup and MKIP */
 509         while (skb) {
 510                 struct sk_buff *next = skb->next;
 511
 512                 skb->next = skb->prev = NULL;
 513                 if (!clip_devs) {
 514                         atm_return(vcc, skb->truesize);
 515                         kfree_skb(skb);
 516                 } else {
 517                         unsigned int len = skb->len;
 518
 519                         skb_get(skb);
 520                         clip_push(vcc, skb);
 521                         PRIV(skb->dev)->stats.rx_packets--;
 522                         PRIV(skb->dev)->stats.rx_bytes -= len;
 523                         kfree_skb(skb);
 524                 }
 525
 526                 skb = next;
 527         }
 528         return 0;
 529 }
 530
 531 static int clip_setentry(struct atm_vcc *vcc, __be32 ip)
 532 {
 533         struct neighbour *neigh;
 534         struct atmarp_entry *entry;
 535         int error;
 536         struct clip_vcc *clip_vcc;
 537         struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, .tos = 1}} };
 538         struct rtable *rt;
 539
 540         if (vcc->push != clip_push) {
 541                 printk(KERN_WARNING "clip_setentry: non-CLIP VCC\n");
 542                 return -EBADF;
 543         }
 544         clip_vcc = CLIP_VCC(vcc);
 545         if (!ip) {
 546                 if (!clip_vcc->entry) {
 547                         printk(KERN_ERR "hiding hidden ATMARP entry\n");
 548                         return 0;
 549                 }
 550                 DPRINTK("setentry: remove\n");
 551                 unlink_clip_vcc(clip_vcc);
 552                 return 0;
 553         }
 554         error = ip_route_output_key(&rt, &fl);
 555         if (error)
 556                 return error;
 557         neigh = __neigh_lookup(&clip_tbl, &ip, rt->u.dst.dev, 1);
 558         ip_rt_put(rt);
 559         if (!neigh)
 560                 return -ENOMEM;
 561         entry = NEIGH2ENTRY(neigh);
 562         if (entry != clip_vcc->entry) {
 563                 if (!clip_vcc->entry)
 564                         DPRINTK("setentry: add\n");
 565                 else {
 566                         DPRINTK("setentry: update\n");
 567                         unlink_clip_vcc(clip_vcc);
 568                 }
 569                 link_vcc(clip_vcc, entry);
 570         }
 571         error = neigh_update(neigh, llc_oui, NUD_PERMANENT,
 572                              NEIGH_UPDATE_F_OVERRIDE | NEIGH_UPDATE_F_ADMIN);
 573         neigh_release(neigh);
 574         return error;
 575 }
 576
 577 static void clip_setup(struct net_device *dev)
 578 {
 579         dev->hard_start_xmit = clip_start_xmit;
 580         /* sg_xmit ... */
 581         dev->get_stats = clip_get_stats;
 582         dev->type = ARPHRD_ATM;
 583         dev->hard_header_len = RFC1483LLC_LEN;
 584         dev->mtu = RFC1626_MTU;
 585         dev->tx_queue_len = 100;        /* "normal" queue (packets) */
 586         /* When using a "real" qdisc, the qdisc determines the queue */
 587         /* length. tx_queue_len is only used for the default case, */
 588         /* without any more elaborate queuing. 100 is a reasonable */
 589         /* compromise between decent burst-tolerance and protection */
 590         /* against memory hogs. */
 591 }
 592
 593 static int clip_create(int number)
 594 {
 595         struct net_device *dev;
 596         struct clip_priv *clip_priv;
 597         int error;
 598
 599         if (number != -1) {
 600                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
 601                         if (PRIV(dev)->number == number)
 602                                 return -EEXIST;
 603         } else {
 604                 number = 0;
 605                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
 606                         if (PRIV(dev)->number >= number)
 607                                 number = PRIV(dev)->number + 1;
 608         }
 609         dev = alloc_netdev(sizeof(struct clip_priv), "", clip_setup);
 610         if (!dev)
 611                 return -ENOMEM;
 612         clip_priv = PRIV(dev);
 613         sprintf(dev->name, "atm%d", number);
 614         spin_lock_init(&clip_priv->xoff_lock);
 615         clip_priv->number = number;
 616         error = register_netdev(dev);
 617         if (error) {
 618                 free_netdev(dev);
 619                 return error;
 620         }
 621         clip_priv->next = clip_devs;
 622         clip_devs = dev;
 623         DPRINTK("registered (net:%s)\n", dev->name);
 624         return number;
 625 }
 626
 627 static int clip_device_event(struct notifier_block *this, unsigned long event,
 628                              void *arg)
 629 {
 630         struct net_device *dev = arg;
 631
 632         if (event == NETDEV_UNREGISTER) {
 633                 neigh_ifdown(&clip_tbl, dev);
 634                 return NOTIFY_DONE;
 635         }
 636
 637         /* ignore non-CLIP devices */
 638         if (dev->type != ARPHRD_ATM || dev->hard_start_xmit != clip_start_xmit)
 639                 return NOTIFY_DONE;
 640
 641         switch (event) {
 642         case NETDEV_UP:
 643                 DPRINTK("clip_device_event NETDEV_UP\n");
 644                 to_atmarpd(act_up, PRIV(dev)->number, 0);
 645                 break;
 646         case NETDEV_GOING_DOWN:
 647                 DPRINTK("clip_device_event NETDEV_DOWN\n");
 648                 to_atmarpd(act_down, PRIV(dev)->number, 0);
 649                 break;
 650         case NETDEV_CHANGE:
 651         case NETDEV_CHANGEMTU:
 652                 DPRINTK("clip_device_event NETDEV_CHANGE*\n");
 653                 to_atmarpd(act_change, PRIV(dev)->number, 0);
 654                 break;
 655         }
 656         return NOTIFY_DONE;
 657 }
 658
 659 static int clip_inet_event(struct notifier_block *this, unsigned long event,
 660                            void *ifa)
 661 {
 662         struct in_device *in_dev;
 663
 664         in_dev = ((struct in_ifaddr *)ifa)->ifa_dev;
 665         if (!in_dev || !in_dev->dev) {
 666                 printk(KERN_WARNING "clip_inet_event: no device\n");
 667                 return NOTIFY_DONE;
 668         }
 669         /*
 670          * Transitions are of the down-change-up type, so it's sufficient to
 671          * handle the change on up.
 672          */
 673         if (event != NETDEV_UP)
 674                 return NOTIFY_DONE;
 675         return clip_device_event(this, NETDEV_CHANGE, in_dev->dev);
 676 }
 677
 678
 679 static struct notifier_block clip_dev_notifier = {
 680         .notifier_call = clip_device_event,
 681 };
 682
 683
 684
 685 static struct notifier_block clip_inet_notifier = {
 686         .notifier_call = clip_inet_event,
 687 };
 688
 689
 690
 691 static void atmarpd_close(struct atm_vcc *vcc)
 692 {
 693         DPRINTK("atmarpd_close\n");
 694
 695         rtnl_lock();
 696         atmarpd = NULL;
 697         skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
 698         rtnl_unlock();
 699
 700         DPRINTK("(done)\n");
 701         module_put(THIS_MODULE);
 702 }
 703
 704
 705 static struct atmdev_ops atmarpd_dev_ops = {
 706         .close = atmarpd_close
 707 };
 708
 709
 710 static struct atm_dev atmarpd_dev = {
 711         .ops =                  &atmarpd_dev_ops,
 712         .type =                 "arpd",
 713         .number =               999,
 714         .lock =                 SPIN_LOCK_UNLOCKED
 715 };
 716
 717
 718 static int atm_init_atmarp(struct atm_vcc *vcc)
 719 {
 720         rtnl_lock();
 721         if (atmarpd) {
 722                 rtnl_unlock();
 723                 return -EADDRINUSE;
 724         }
 725
 726         mod_timer(&idle_timer, jiffies+CLIP_CHECK_INTERVAL*HZ);
 727
 728         atmarpd = vcc;
 729         set_bit(ATM_VF_META,&vcc->flags);
 730         set_bit(ATM_VF_READY,&vcc->flags);
 731             /* allow replies and avoid getting closed if signaling dies */
 732         vcc->dev = &atmarpd_dev;
 733         vcc_insert_socket(sk_atm(vcc));
 734         vcc->push = NULL;
 735         vcc->pop = NULL; /* crash */
 736         vcc->push_oam = NULL; /* crash */
 737         rtnl_unlock();
 738         return 0;
 739 }
 740
 741 static int clip_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 742 {
 743         struct atm_vcc *vcc = ATM_SD(sock);
 744         int err = 0;
 745
 746         switch (cmd) {
 747         case SIOCMKCLIP:
 748         case ATMARPD_CTRL:
 749         case ATMARP_MKIP:
 750         case ATMARP_SETENTRY:
 751         case ATMARP_ENCAP:
 752                 if (!capable(CAP_NET_ADMIN))
 753                         return -EPERM;
 754                 break;
 755         default:
 756                 return -ENOIOCTLCMD;
 757         }
 758
 759         switch (cmd) {
 760         case SIOCMKCLIP:
 761                 err = clip_create(arg);
 762                 break;
 763         case ATMARPD_CTRL:
 764                 err = atm_init_atmarp(vcc);
 765                 if (!err) {
 766                         sock->state = SS_CONNECTED;
 767                         __module_get(THIS_MODULE);
 768                 }
 769                 break;
 770         case ATMARP_MKIP:
 771                 err = clip_mkip(vcc, arg);
 772                 break;
 773         case ATMARP_SETENTRY:
 774                 err = clip_setentry(vcc, (__force __be32)arg);
 775                 break;
 776         case ATMARP_ENCAP:
 777                 err = clip_encap(vcc, arg);
 778                 break;
 779         }
 780         return err;
 781 }
 782
 783 static struct atm_ioctl clip_ioctl_ops = {
 784         .owner = THIS_MODULE,
 785         .ioctl = clip_ioctl,
 786 };
 787
 788 #ifdef CONFIG_PROC_FS
 789
 790 static void svc_addr(struct seq_file *seq, struct sockaddr_atmsvc *addr)
 791 {
 792         static int code[] = { 1, 2, 10, 6, 1, 0 };
 793         static int e164[] = { 1, 8, 4, 6, 1, 0 };
 794
 795         if (*addr->sas_addr.pub) {
 796                 seq_printf(seq, "%s", addr->sas_addr.pub);
 797                 if (*addr->sas_addr.prv)
 798                         seq_putc(seq, '+');
 799         } else if (!*addr->sas_addr.prv) {
 800                 seq_printf(seq, "%s", "(none)");
 801                 return;
 802         }
 803         if (*addr->sas_addr.prv) {
 804                 unsigned char *prv = addr->sas_addr.prv;
 805                 int *fields;
 806                 int i, j;
 807
 808                 fields = *prv == ATM_AFI_E164 ? e164 : code;
 809                 for (i = 0; fields[i]; i++) {
 810                         for (j = fields[i]; j; j--)
 811                                 seq_printf(seq, "%02X", *prv++);
 812                         if (fields[i + 1])
 813                                 seq_putc(seq, '.');
 814                 }
 815         }
 816 }
 817
 818 /* This means the neighbour entry has no attached VCC objects. */
 819 #define SEQ_NO_VCC_TOKEN        ((void *) 2)
 820
 821 static void atmarp_info(struct seq_file *seq, struct net_device *dev,
 822                         struct atmarp_entry *entry, struct clip_vcc *clip_vcc)
 823 {
 824         unsigned long exp;
 825         char buf[17];
 826         int svc, llc, off;
 827
 828         svc = ((clip_vcc == SEQ_NO_VCC_TOKEN) ||
 829                (sk_atm(clip_vcc->vcc)->sk_family == AF_ATMSVC));
 830
 831         llc = ((clip_vcc == SEQ_NO_VCC_TOKEN) || clip_vcc->encap);
 832
 833         if (clip_vcc == SEQ_NO_VCC_TOKEN)
 834                 exp = entry->neigh->used;
 835         else
 836                 exp = clip_vcc->last_use;
 837
 838         exp = (jiffies - exp) / HZ;
 839
 840         seq_printf(seq, "%-6s%-4s%-4s%5ld ",
 841                    dev->name, svc ? "SVC" : "PVC", llc ? "LLC" : "NULL", exp);
 842
 843         off = scnprintf(buf, sizeof(buf) - 1, "%d.%d.%d.%d",
 844                         NIPQUAD(entry->ip));
 845         while (off < 16)
 846                 buf[off++] = ' ';
 847         buf[off] = '\0';
 848         seq_printf(seq, "%s", buf);
 849
 850         if (clip_vcc == SEQ_NO_VCC_TOKEN) {
 851                 if (time_before(jiffies, entry->expires))
 852                         seq_printf(seq, "(resolving)\n");
 853                 else
 854                         seq_printf(seq, "(expired, ref %d)\n",
 855                                    atomic_read(&entry->neigh->refcnt));
 856         } else if (!svc) {
 857                 seq_printf(seq, "%d.%d.%d\n",
 858                            clip_vcc->vcc->dev->number,
 859                            clip_vcc->vcc->vpi, clip_vcc->vcc->vci);
 860         } else {
 861                 svc_addr(seq, &clip_vcc->vcc->remote);
 862                 seq_putc(seq, '\n');
 863         }
 864 }
 865
 866 struct clip_seq_state {
 867         /* This member must be first. */
 868         struct neigh_seq_state ns;
 869
 870         /* Local to clip specific iteration. */
 871         struct clip_vcc *vcc;
 872 };
 873
 874 static struct clip_vcc *clip_seq_next_vcc(struct atmarp_entry *e,
 875                                           struct clip_vcc *curr)
 876 {
 877         if (!curr) {
 878                 curr = e->vccs;
 879                 if (!curr)
 880                         return SEQ_NO_VCC_TOKEN;
 881                 return curr;
 882         }
 883         if (curr == SEQ_NO_VCC_TOKEN)
 884                 return NULL;
 885
 886         curr = curr->next;
 887
 888         return curr;
 889 }
 890
 891 static void *clip_seq_vcc_walk(struct clip_seq_state *state,
 892                                struct atmarp_entry *e, loff_t * pos)
 893 {
 894         struct clip_vcc *vcc = state->vcc;
 895
 896         vcc = clip_seq_next_vcc(e, vcc);
 897         if (vcc && pos != NULL) {
 898                 while (*pos) {
 899                         vcc = clip_seq_next_vcc(e, vcc);
 900                         if (!vcc)
 901                                 break;
 902                         --(*pos);
 903                 }
 904         }
 905         state->vcc = vcc;
 906
 907         return vcc;
 908 }
 909
 910 static void *clip_seq_sub_iter(struct neigh_seq_state *_state,
 911                                struct neighbour *n, loff_t * pos)
 912 {
 913         struct clip_seq_state *state = (struct clip_seq_state *)_state;
 914
 915         return clip_seq_vcc_walk(state, NEIGH2ENTRY(n), pos);
 916 }
 917
 918 static void *clip_seq_start(struct seq_file *seq, loff_t * pos)
 919 {
 920         return neigh_seq_start(seq, pos, &clip_tbl, NEIGH_SEQ_NEIGH_ONLY);
 921 }
 922
 923 static int clip_seq_show(struct seq_file *seq, void *v)
 924 {
 925         static char atm_arp_banner[] =
 926             "IPitf TypeEncp Idle IP address      ATM address\n";
 927
 928         if (v == SEQ_START_TOKEN) {
 929                 seq_puts(seq, atm_arp_banner);
 930         } else {
 931                 struct clip_seq_state *state = seq->private;
 932                 struct neighbour *n = v;
 933                 struct clip_vcc *vcc = state->vcc;
 934
 935                 atmarp_info(seq, n->dev, NEIGH2ENTRY(n), vcc);
 936         }
 937         return 0;
 938 }
 939
 940 static struct seq_operations arp_seq_ops = {
 941         .start  = clip_seq_start,
 942         .next   = neigh_seq_next,
 943         .stop   = neigh_seq_stop,
 944         .show   = clip_seq_show,
 945 };
 946
 947 static int arp_seq_open(struct inode *inode, struct file *file)
 948 {
 949         struct clip_seq_state *state;
 950         struct seq_file *seq;
 951         int rc = -EAGAIN;
 952
 953         state = kzalloc(sizeof(*state), GFP_KERNEL);
 954         if (!state) {
 955                 rc = -ENOMEM;
 956                 goto out_kfree;
 957         }
 958         state->ns.neigh_sub_iter = clip_seq_sub_iter;
 959
 960         rc = seq_open(file, &arp_seq_ops);
 961         if (rc)
 962                 goto out_kfree;
 963
 964         seq = file->private_data;
 965         seq->private = state;
 966 out:
 967         return rc;
 968
 969 out_kfree:
 970         kfree(state);
 971         goto out;
 972 }
 973
 974 static struct file_operations arp_seq_fops = {
 975         .open           = arp_seq_open,
 976         .read           = seq_read,
 977         .llseek         = seq_lseek,
 978         .release        = seq_release_private,
 979         .owner          = THIS_MODULE
 980 };
 981 #endif
 982
 983 static int __init atm_clip_init(void)
 984 {
 985         neigh_table_init_no_netlink(&clip_tbl);
 986
 987         clip_tbl_hook = &clip_tbl;
 988         register_atm_ioctl(&clip_ioctl_ops);
 989         register_netdevice_notifier(&clip_dev_notifier);
 990         register_inetaddr_notifier(&clip_inet_notifier);
 991
 992         setup_timer(&idle_timer, idle_timer_check, 0);
 993
 994 #ifdef CONFIG_PROC_FS
 995         {
 996                 struct proc_dir_entry *p;
 997
 998                 p = create_proc_entry("arp", S_IRUGO, atm_proc_root);
 999                 if (p)
1000                         p->proc_fops = &arp_seq_fops;
1001         }
1002 #endif
1003
1004         return 0;
1005 }
1006
1007 static void __exit atm_clip_exit(void)
1008 {
1009         struct net_device *dev, *next;
1010
1011         remove_proc_entry("arp", atm_proc_root);
1012
1013         unregister_inetaddr_notifier(&clip_inet_notifier);
1014         unregister_netdevice_notifier(&clip_dev_notifier);
1015
1016         deregister_atm_ioctl(&clip_ioctl_ops);
1017
1018         /* First, stop the idle timer, so it stops banging
1019          * on the table.
1020          */
1021         del_timer_sync(&idle_timer);
1022
1023         /* Next, purge the table, so that the device
1024          * unregister loop below does not hang due to
1025          * device references remaining in the table.
1026          */
1027         neigh_ifdown(&clip_tbl, NULL);
1028
1029         dev = clip_devs;
1030         while (dev) {
1031                 next = PRIV(dev)->next;
1032                 unregister_netdev(dev);
1033                 free_netdev(dev);
1034                 dev = next;
1035         }
1036
1037         /* Now it is safe to fully shutdown whole table. */
1038         neigh_table_clear(&clip_tbl);
1039
1040         clip_tbl_hook = NULL;
1041 }
1042
1043 module_init(atm_clip_init);
1044 module_exit(atm_clip_exit);
1045 MODULE_AUTHOR("Werner Almesberger");
1046 MODULE_DESCRIPTION("Classical/IP over ATM interface");
1047 MODULE_LICENSE("GPL");