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/proc_fs.h>
  27 #include <linux/seq_file.h>
  28 #include <linux/rcupdate.h>
  29 #include <linux/jhash.h>
  30 #include <net/route.h> /* for struct rtable and routing */
  31 #include <net/icmp.h> /* icmp_send */
  32 #include <asm/param.h> /* for HZ */
  33 #include <asm/byteorder.h> /* for htons etc. */
  34 #include <asm/system.h> /* save/restore_flags */
  35 #include <asm/uaccess.h>
  36 #include <asm/atomic.h>
  37
  38 #include "common.h"
  39 #include "resources.h"
  40 #include "ipcommon.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, unsigned long 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 = ((u16 *) 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 *) 0xdeadbeef;
 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                 ((u16 *) 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_head copy;
 472         struct sk_buff *skb;
 473
 474         if (!vcc->push)
 475                 return -EBADFD;
 476         clip_vcc = kmalloc(sizeof(struct clip_vcc), GFP_KERNEL);
 477         if (!clip_vcc)
 478                 return -ENOMEM;
 479         DPRINTK("mkip clip_vcc %p vcc %p\n", clip_vcc, vcc);
 480         clip_vcc->vcc = vcc;
 481         vcc->user_back = clip_vcc;
 482         set_bit(ATM_VF_IS_CLIP, &vcc->flags);
 483         clip_vcc->entry = NULL;
 484         clip_vcc->xoff = 0;
 485         clip_vcc->encap = 1;
 486         clip_vcc->last_use = jiffies;
 487         clip_vcc->idle_timeout = timeout * HZ;
 488         clip_vcc->old_push = vcc->push;
 489         clip_vcc->old_pop = vcc->pop;
 490         vcc->push = clip_push;
 491         vcc->pop = clip_pop;
 492         skb_queue_head_init(&copy);
 493         skb_migrate(&sk_atm(vcc)->sk_receive_queue, &copy);
 494         /* re-process everything received between connection setup and MKIP */
 495         while ((skb = skb_dequeue(&copy)) != NULL)
 496                 if (!clip_devs) {
 497                         atm_return(vcc, skb->truesize);
 498                         kfree_skb(skb);
 499                 } else {
 500                         unsigned int len = skb->len;
 501
 502                         clip_push(vcc, skb);
 503                         PRIV(skb->dev)->stats.rx_packets--;
 504                         PRIV(skb->dev)->stats.rx_bytes -= len;
 505                 }
 506         return 0;
 507 }
 508
 509 static int clip_setentry(struct atm_vcc *vcc, u32 ip)
 510 {
 511         struct neighbour *neigh;
 512         struct atmarp_entry *entry;
 513         int error;
 514         struct clip_vcc *clip_vcc;
 515         struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, .tos = 1}} };
 516         struct rtable *rt;
 517
 518         if (vcc->push != clip_push) {
 519                 printk(KERN_WARNING "clip_setentry: non-CLIP VCC\n");
 520                 return -EBADF;
 521         }
 522         clip_vcc = CLIP_VCC(vcc);
 523         if (!ip) {
 524                 if (!clip_vcc->entry) {
 525                         printk(KERN_ERR "hiding hidden ATMARP entry\n");
 526                         return 0;
 527                 }
 528                 DPRINTK("setentry: remove\n");
 529                 unlink_clip_vcc(clip_vcc);
 530                 return 0;
 531         }
 532         error = ip_route_output_key(&rt, &fl);
 533         if (error)
 534                 return error;
 535         neigh = __neigh_lookup(&clip_tbl, &ip, rt->u.dst.dev, 1);
 536         ip_rt_put(rt);
 537         if (!neigh)
 538                 return -ENOMEM;
 539         entry = NEIGH2ENTRY(neigh);
 540         if (entry != clip_vcc->entry) {
 541                 if (!clip_vcc->entry)
 542                         DPRINTK("setentry: add\n");
 543                 else {
 544                         DPRINTK("setentry: update\n");
 545                         unlink_clip_vcc(clip_vcc);
 546                 }
 547                 link_vcc(clip_vcc, entry);
 548         }
 549         error = neigh_update(neigh, llc_oui, NUD_PERMANENT,
 550                              NEIGH_UPDATE_F_OVERRIDE | NEIGH_UPDATE_F_ADMIN);
 551         neigh_release(neigh);
 552         return error;
 553 }
 554
 555 static void clip_setup(struct net_device *dev)
 556 {
 557         dev->hard_start_xmit = clip_start_xmit;
 558         /* sg_xmit ... */
 559         dev->get_stats = clip_get_stats;
 560         dev->type = ARPHRD_ATM;
 561         dev->hard_header_len = RFC1483LLC_LEN;
 562         dev->mtu = RFC1626_MTU;
 563         dev->tx_queue_len = 100;        /* "normal" queue (packets) */
 564         /* When using a "real" qdisc, the qdisc determines the queue */
 565         /* length. tx_queue_len is only used for the default case, */
 566         /* without any more elaborate queuing. 100 is a reasonable */
 567         /* compromise between decent burst-tolerance and protection */
 568         /* against memory hogs. */
 569 }
 570
 571 static int clip_create(int number)
 572 {
 573         struct net_device *dev;
 574         struct clip_priv *clip_priv;
 575         int error;
 576
 577         if (number != -1) {
 578                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
 579                         if (PRIV(dev)->number == number)
 580                                 return -EEXIST;
 581         } else {
 582                 number = 0;
 583                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
 584                         if (PRIV(dev)->number >= number)
 585                                 number = PRIV(dev)->number + 1;
 586         }
 587         dev = alloc_netdev(sizeof(struct clip_priv), "", clip_setup);
 588         if (!dev)
 589                 return -ENOMEM;
 590         clip_priv = PRIV(dev);
 591         sprintf(dev->name, "atm%d", number);
 592         spin_lock_init(&clip_priv->xoff_lock);
 593         clip_priv->number = number;
 594         error = register_netdev(dev);
 595         if (error) {
 596                 free_netdev(dev);
 597                 return error;
 598         }
 599         clip_priv->next = clip_devs;
 600         clip_devs = dev;
 601         DPRINTK("registered (net:%s)\n", dev->name);
 602         return number;
 603 }
 604
 605 static int clip_device_event(struct notifier_block *this, unsigned long event,
 606                              void *arg)
 607 {
 608         struct net_device *dev = arg;
 609
 610         if (event == NETDEV_UNREGISTER) {
 611                 neigh_ifdown(&clip_tbl, dev);
 612                 return NOTIFY_DONE;
 613         }
 614
 615         /* ignore non-CLIP devices */
 616         if (dev->type != ARPHRD_ATM || dev->hard_start_xmit != clip_start_xmit)
 617                 return NOTIFY_DONE;
 618
 619         switch (event) {
 620         case NETDEV_UP:
 621                 DPRINTK("clip_device_event NETDEV_UP\n");
 622                 to_atmarpd(act_up, PRIV(dev)->number, 0);
 623                 break;
 624         case NETDEV_GOING_DOWN:
 625                 DPRINTK("clip_device_event NETDEV_DOWN\n");
 626                 to_atmarpd(act_down, PRIV(dev)->number, 0);
 627                 break;
 628         case NETDEV_CHANGE:
 629         case NETDEV_CHANGEMTU:
 630                 DPRINTK("clip_device_event NETDEV_CHANGE*\n");
 631                 to_atmarpd(act_change, PRIV(dev)->number, 0);
 632                 break;
 633         }
 634         return NOTIFY_DONE;
 635 }
 636
 637 static int clip_inet_event(struct notifier_block *this, unsigned long event,
 638                            void *ifa)
 639 {
 640         struct in_device *in_dev;
 641
 642         in_dev = ((struct in_ifaddr *)ifa)->ifa_dev;
 643         if (!in_dev || !in_dev->dev) {
 644                 printk(KERN_WARNING "clip_inet_event: no device\n");
 645                 return NOTIFY_DONE;
 646         }
 647         /*
 648          * Transitions are of the down-change-up type, so it's sufficient to
 649          * handle the change on up.
 650          */
 651         if (event != NETDEV_UP)
 652                 return NOTIFY_DONE;
 653         return clip_device_event(this, NETDEV_CHANGE, in_dev->dev);
 654 }
 655
 656
 657 static struct notifier_block clip_dev_notifier = {
 658         .notifier_call = clip_device_event,
 659 };
 660
 661
 662
 663 static struct notifier_block clip_inet_notifier = {
 664         .notifier_call = clip_inet_event,
 665 };
 666
 667
 668
 669 static void atmarpd_close(struct atm_vcc *vcc)
 670 {
 671         DPRINTK("atmarpd_close\n");
 672
 673         rtnl_lock();
 674         atmarpd = NULL;
 675         skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
 676         rtnl_unlock();
 677
 678         DPRINTK("(done)\n");
 679         module_put(THIS_MODULE);
 680 }
 681
 682
 683 static struct atmdev_ops atmarpd_dev_ops = {
 684         .close = atmarpd_close
 685 };
 686
 687
 688 static struct atm_dev atmarpd_dev = {
 689         .ops =                  &atmarpd_dev_ops,
 690         .type =                 "arpd",
 691         .number =               999,
 692         .lock =                 SPIN_LOCK_UNLOCKED
 693 };
 694
 695
 696 static int atm_init_atmarp(struct atm_vcc *vcc)
 697 {
 698         rtnl_lock();
 699         if (atmarpd) {
 700                 rtnl_unlock();
 701                 return -EADDRINUSE;
 702         }
 703
 704         mod_timer(&idle_timer, jiffies+CLIP_CHECK_INTERVAL*HZ);
 705
 706         atmarpd = vcc;
 707         set_bit(ATM_VF_META,&vcc->flags);
 708         set_bit(ATM_VF_READY,&vcc->flags);
 709             /* allow replies and avoid getting closed if signaling dies */
 710         vcc->dev = &atmarpd_dev;
 711         vcc_insert_socket(sk_atm(vcc));
 712         vcc->push = NULL;
 713         vcc->pop = NULL; /* crash */
 714         vcc->push_oam = NULL; /* crash */
 715         rtnl_unlock();
 716         return 0;
 717 }
 718
 719 static int clip_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 720 {
 721         struct atm_vcc *vcc = ATM_SD(sock);
 722         int err = 0;
 723
 724         switch (cmd) {
 725         case SIOCMKCLIP:
 726         case ATMARPD_CTRL:
 727         case ATMARP_MKIP:
 728         case ATMARP_SETENTRY:
 729         case ATMARP_ENCAP:
 730                 if (!capable(CAP_NET_ADMIN))
 731                         return -EPERM;
 732                 break;
 733         default:
 734                 return -ENOIOCTLCMD;
 735         }
 736
 737         switch (cmd) {
 738         case SIOCMKCLIP:
 739                 err = clip_create(arg);
 740                 break;
 741         case ATMARPD_CTRL:
 742                 err = atm_init_atmarp(vcc);
 743                 if (!err) {
 744                         sock->state = SS_CONNECTED;
 745                         __module_get(THIS_MODULE);
 746                 }
 747                 break;
 748         case ATMARP_MKIP:
 749                 err = clip_mkip(vcc, arg);
 750                 break;
 751         case ATMARP_SETENTRY:
 752                 err = clip_setentry(vcc, arg);
 753                 break;
 754         case ATMARP_ENCAP:
 755                 err = clip_encap(vcc, arg);
 756                 break;
 757         }
 758         return err;
 759 }
 760
 761 static struct atm_ioctl clip_ioctl_ops = {
 762         .owner = THIS_MODULE,
 763         .ioctl = clip_ioctl,
 764 };
 765
 766 #ifdef CONFIG_PROC_FS
 767
 768 static void svc_addr(struct seq_file *seq, struct sockaddr_atmsvc *addr)
 769 {
 770         static int code[] = { 1, 2, 10, 6, 1, 0 };
 771         static int e164[] = { 1, 8, 4, 6, 1, 0 };
 772
 773         if (*addr->sas_addr.pub) {
 774                 seq_printf(seq, "%s", addr->sas_addr.pub);
 775                 if (*addr->sas_addr.prv)
 776                         seq_putc(seq, '+');
 777         } else if (!*addr->sas_addr.prv) {
 778                 seq_printf(seq, "%s", "(none)");
 779                 return;
 780         }
 781         if (*addr->sas_addr.prv) {
 782                 unsigned char *prv = addr->sas_addr.prv;
 783                 int *fields;
 784                 int i, j;
 785
 786                 fields = *prv == ATM_AFI_E164 ? e164 : code;
 787                 for (i = 0; fields[i]; i++) {
 788                         for (j = fields[i]; j; j--)
 789                                 seq_printf(seq, "%02X", *prv++);
 790                         if (fields[i + 1])
 791                                 seq_putc(seq, '.');
 792                 }
 793         }
 794 }
 795
 796 /* This means the neighbour entry has no attached VCC objects. */
 797 #define SEQ_NO_VCC_TOKEN        ((void *) 2)
 798
 799 static void atmarp_info(struct seq_file *seq, struct net_device *dev,
 800                         struct atmarp_entry *entry, struct clip_vcc *clip_vcc)
 801 {
 802         unsigned long exp;
 803         char buf[17];
 804         int svc, llc, off;
 805
 806         svc = ((clip_vcc == SEQ_NO_VCC_TOKEN) ||
 807                (sk_atm(clip_vcc->vcc)->sk_family == AF_ATMSVC));
 808
 809         llc = ((clip_vcc == SEQ_NO_VCC_TOKEN) || clip_vcc->encap);
 810
 811         if (clip_vcc == SEQ_NO_VCC_TOKEN)
 812                 exp = entry->neigh->used;
 813         else
 814                 exp = clip_vcc->last_use;
 815
 816         exp = (jiffies - exp) / HZ;
 817
 818         seq_printf(seq, "%-6s%-4s%-4s%5ld ",
 819                    dev->name, svc ? "SVC" : "PVC", llc ? "LLC" : "NULL", exp);
 820
 821         off = scnprintf(buf, sizeof(buf) - 1, "%d.%d.%d.%d",
 822                         NIPQUAD(entry->ip));
 823         while (off < 16)
 824                 buf[off++] = ' ';
 825         buf[off] = '\0';
 826         seq_printf(seq, "%s", buf);
 827
 828         if (clip_vcc == SEQ_NO_VCC_TOKEN) {
 829                 if (time_before(jiffies, entry->expires))
 830                         seq_printf(seq, "(resolving)\n");
 831                 else
 832                         seq_printf(seq, "(expired, ref %d)\n",
 833                                    atomic_read(&entry->neigh->refcnt));
 834         } else if (!svc) {
 835                 seq_printf(seq, "%d.%d.%d\n",
 836                            clip_vcc->vcc->dev->number,
 837                            clip_vcc->vcc->vpi, clip_vcc->vcc->vci);
 838         } else {
 839                 svc_addr(seq, &clip_vcc->vcc->remote);
 840                 seq_putc(seq, '\n');
 841         }
 842 }
 843
 844 struct clip_seq_state {
 845         /* This member must be first. */
 846         struct neigh_seq_state ns;
 847
 848         /* Local to clip specific iteration. */
 849         struct clip_vcc *vcc;
 850 };
 851
 852 static struct clip_vcc *clip_seq_next_vcc(struct atmarp_entry *e,
 853                                           struct clip_vcc *curr)
 854 {
 855         if (!curr) {
 856                 curr = e->vccs;
 857                 if (!curr)
 858                         return SEQ_NO_VCC_TOKEN;
 859                 return curr;
 860         }
 861         if (curr == SEQ_NO_VCC_TOKEN)
 862                 return NULL;
 863
 864         curr = curr->next;
 865
 866         return curr;
 867 }
 868
 869 static void *clip_seq_vcc_walk(struct clip_seq_state *state,
 870                                struct atmarp_entry *e, loff_t * pos)
 871 {
 872         struct clip_vcc *vcc = state->vcc;
 873
 874         vcc = clip_seq_next_vcc(e, vcc);
 875         if (vcc && pos != NULL) {
 876                 while (*pos) {
 877                         vcc = clip_seq_next_vcc(e, vcc);
 878                         if (!vcc)
 879                                 break;
 880                         --(*pos);
 881                 }
 882         }
 883         state->vcc = vcc;
 884
 885         return vcc;
 886 }
 887
 888 static void *clip_seq_sub_iter(struct neigh_seq_state *_state,
 889                                struct neighbour *n, loff_t * pos)
 890 {
 891         struct clip_seq_state *state = (struct clip_seq_state *)_state;
 892
 893         return clip_seq_vcc_walk(state, NEIGH2ENTRY(n), pos);
 894 }
 895
 896 static void *clip_seq_start(struct seq_file *seq, loff_t * pos)
 897 {
 898         return neigh_seq_start(seq, pos, &clip_tbl, NEIGH_SEQ_NEIGH_ONLY);
 899 }
 900
 901 static int clip_seq_show(struct seq_file *seq, void *v)
 902 {
 903         static char atm_arp_banner[] =
 904             "IPitf TypeEncp Idle IP address      ATM address\n";
 905
 906         if (v == SEQ_START_TOKEN) {
 907                 seq_puts(seq, atm_arp_banner);
 908         } else {
 909                 struct clip_seq_state *state = seq->private;
 910                 struct neighbour *n = v;
 911                 struct clip_vcc *vcc = state->vcc;
 912
 913                 atmarp_info(seq, n->dev, NEIGH2ENTRY(n), vcc);
 914         }
 915         return 0;
 916 }
 917
 918 static struct seq_operations arp_seq_ops = {
 919         .start  = clip_seq_start,
 920         .next   = neigh_seq_next,
 921         .stop   = neigh_seq_stop,
 922         .show   = clip_seq_show,
 923 };
 924
 925 static int arp_seq_open(struct inode *inode, struct file *file)
 926 {
 927         struct clip_seq_state *state;
 928         struct seq_file *seq;
 929         int rc = -EAGAIN;
 930
 931         state = kmalloc(sizeof(*state), GFP_KERNEL);
 932         if (!state) {
 933                 rc = -ENOMEM;
 934                 goto out_kfree;
 935         }
 936         memset(state, 0, sizeof(*state));
 937         state->ns.neigh_sub_iter = clip_seq_sub_iter;
 938
 939         rc = seq_open(file, &arp_seq_ops);
 940         if (rc)
 941                 goto out_kfree;
 942
 943         seq = file->private_data;
 944         seq->private = state;
 945 out:
 946         return rc;
 947
 948 out_kfree:
 949         kfree(state);
 950         goto out;
 951 }
 952
 953 static struct file_operations arp_seq_fops = {
 954         .open           = arp_seq_open,
 955         .read           = seq_read,
 956         .llseek         = seq_lseek,
 957         .release        = seq_release_private,
 958         .owner          = THIS_MODULE
 959 };
 960 #endif
 961
 962 static int __init atm_clip_init(void)
 963 {
 964         struct proc_dir_entry *p;
 965         neigh_table_init_no_netlink(&clip_tbl);
 966
 967         clip_tbl_hook = &clip_tbl;
 968         register_atm_ioctl(&clip_ioctl_ops);
 969         register_netdevice_notifier(&clip_dev_notifier);
 970         register_inetaddr_notifier(&clip_inet_notifier);
 971
 972         setup_timer(&idle_timer, idle_timer_check, 0);
 973
 974         p = create_proc_entry("arp", S_IRUGO, atm_proc_root);
 975         if (p)
 976                 p->proc_fops = &arp_seq_fops;
 977
 978         return 0;
 979 }
 980
 981 static void __exit atm_clip_exit(void)
 982 {
 983         struct net_device *dev, *next;
 984
 985         remove_proc_entry("arp", atm_proc_root);
 986
 987         unregister_inetaddr_notifier(&clip_inet_notifier);
 988         unregister_netdevice_notifier(&clip_dev_notifier);
 989
 990         deregister_atm_ioctl(&clip_ioctl_ops);
 991
 992         /* First, stop the idle timer, so it stops banging
 993          * on the table.
 994          */
 995         del_timer_sync(&idle_timer);
 996
 997         /* Next, purge the table, so that the device
 998          * unregister loop below does not hang due to
 999          * device references remaining in the table.
1000          */
1001         neigh_ifdown(&clip_tbl, NULL);
1002
1003         dev = clip_devs;
1004         while (dev) {
1005                 next = PRIV(dev)->next;
1006                 unregister_netdev(dev);
1007                 free_netdev(dev);
1008                 dev = next;
1009         }
1010
1011         /* Now it is safe to fully shutdown whole table. */
1012         neigh_table_clear(&clip_tbl);
1013
1014         clip_tbl_hook = NULL;
1015 }
1016
1017 module_init(atm_clip_init);
1018 module_exit(atm_clip_exit);
1019 MODULE_AUTHOR("Werner Almesberger");
1020 MODULE_DESCRIPTION("Classical/IP over ATM interface");
1021 MODULE_LICENSE("GPL");