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  * Changes:
   6  *      Harald Welte <laforge@gnumonks.org>:
   7  *      - backport DaveM's generalized neighbour cache from 2.6.9-rcX */
   8
   9
  10 #include <linux/config.h>
  11 #include <linux/string.h>
  12 #include <linux/errno.h>
  13 #include <linux/kernel.h> /* for UINT_MAX */
  14 #include <linux/module.h>
  15 #include <linux/init.h>
  16 #include <linux/netdevice.h>
  17 #include <linux/skbuff.h>
  18 #include <linux/wait.h>
  19 #include <linux/timer.h>
  20 #include <linux/if_arp.h> /* for some manifest constants */
  21 #include <linux/notifier.h>
  22 #include <linux/atm.h>
  23 #include <linux/atmdev.h>
  24 #include <linux/atmclip.h>
  25 #include <linux/atmarp.h>
  26 #include <linux/ip.h> /* for net/route.h */
  27 #include <linux/in.h> /* for struct sockaddr_in */
  28 #include <linux/if.h> /* for IFF_UP */
  29 #include <linux/inetdevice.h>
  30 #include <linux/bitops.h>
  31 #include <linux/jhash.h>
  32 #include <net/route.h> /* for struct rtable and routing */
  33 #include <net/icmp.h> /* icmp_send */
  34 #include <asm/param.h> /* for HZ */
  35 #include <asm/byteorder.h> /* for htons etc. */
  36 #include <asm/system.h> /* save/restore_flags */
  37 #include <asm/uaccess.h>
  38 #include <asm/atomic.h>
  39
  40 #include "common.h"
  41 #include "resources.h"
  42 #include "ipcommon.h"
  43 #include <net/atmclip.h>
  44
  45
  46 #if 0
  47 #define DPRINTK(format,args...) printk(format,##args)
  48 #else
  49 #define DPRINTK(format,args...)
  50 #endif
  51
  52
  53 struct net_device *clip_devs = NULL;
  54 struct atm_vcc *atmarpd = NULL;
  55 static struct neigh_table clip_tbl;
  56 static struct timer_list idle_timer;
  57 static int start_timer = 1;
  58
  59
  60 static int to_atmarpd(enum atmarp_ctrl_type type,int itf,unsigned long ip)
  61 {
  62         struct atmarp_ctrl *ctrl;
  63         struct sk_buff *skb;
  64
  65         DPRINTK("to_atmarpd(%d)\n",type);
  66         if (!atmarpd) return -EUNATCH;
  67         skb = alloc_skb(sizeof(struct atmarp_ctrl),GFP_ATOMIC);
  68         if (!skb) return -ENOMEM;
  69         ctrl = (struct atmarp_ctrl *) skb_put(skb,sizeof(struct atmarp_ctrl));
  70         ctrl->type = type;
  71         ctrl->itf_num = itf;
  72         ctrl->ip = ip;
  73         atm_force_charge(atmarpd,skb->truesize);
  74         skb_queue_tail(&atmarpd->sk->receive_queue,skb);
  75         wake_up(&atmarpd->sleep);
  76         return 0;
  77 }
  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
  92 static void unlink_clip_vcc(struct clip_vcc *clip_vcc)
  93 {
  94         struct atmarp_entry *entry = clip_vcc->entry;
  95         struct clip_vcc **walk;
  96
  97         if (!entry) {
  98                 printk(KERN_CRIT "!clip_vcc->entry (clip_vcc %p)\n",clip_vcc);
  99                 return;
 100         }
 101         spin_lock_bh(&entry->neigh->dev->xmit_lock);    /* block clip_start_xmit() */
 102         entry->neigh->used = jiffies;
 103         for (walk = &entry->vccs; *walk; walk = &(*walk)->next)
 104                 if (*walk == clip_vcc) {
 105                         int error;
 106
 107                         *walk = clip_vcc->next; /* atomic */
 108                         clip_vcc->entry = NULL;
 109                         if (clip_vcc->xoff)
 110                                 netif_wake_queue(entry->neigh->dev);
 111                         if (entry->vccs)
 112                                 goto out;
 113                         entry->expires = jiffies-1;
 114                                 /* force resolution or expiration */
 115                         error = neigh_update(entry->neigh,NULL,NUD_NONE,0,0);
 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         spin_unlock_bh(&entry->neigh->dev->xmit_lock);
 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
 187 static void clip_push(struct atm_vcc *vcc,struct sk_buff *skb)
 188 {
 189         struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
 190
 191         DPRINTK("clip push\n");
 192         if (!skb) {
 193                 DPRINTK("removing VCC %p\n",clip_vcc);
 194                 if (clip_vcc->entry) 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->mac.raw = skb->data;
 208         if (!clip_vcc->encap || skb->len < RFC1483LLC_LEN || memcmp(skb->data,
 209             llc_oui,sizeof(llc_oui))) skb->protocol = htons(ETH_P_IP);
 210         else {
 211                 skb->protocol = ((u16 *) skb->data)[3];
 212                 skb_pull(skb,RFC1483LLC_LEN);
 213                 if (skb->protocol == htons(ETH_P_ARP)) {
 214                         PRIV(skb->dev)->stats.rx_packets++;
 215                         PRIV(skb->dev)->stats.rx_bytes += skb->len;
 216                         clip_arp_rcv(skb);
 217                         return;
 218                 }
 219         }
 220         clip_vcc->last_use = jiffies;
 221         PRIV(skb->dev)->stats.rx_packets++;
 222         PRIV(skb->dev)->stats.rx_bytes += skb->len;
 223         memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
 224         netif_rx(skb);
 225 }
 226
 227
 228 /*
 229  * Note: these spinlocks _must_not_ block on non-SMP. The only goal is that
 230  * clip_pop is atomic with respect to the critical section in clip_start_xmit.
 231  */
 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         DPRINTK("clip_pop(vcc %p)\n",vcc);
 242         clip_vcc->old_pop(vcc,skb);
 243         /* skb->dev == NULL in outbound ARP packets */
 244         if (!dev) return;
 245         spin_lock_irqsave(&PRIV(dev)->xoff_lock,flags);
 246         if (atm_may_send(vcc,0)) {
 247                 old = xchg(&clip_vcc->xoff,0);
 248                 if (old) netif_wake_queue(dev);
 249         }
 250         spin_unlock_irqrestore(&PRIV(dev)->xoff_lock,flags);
 251 }
 252
 253
 254 static void clip_neigh_destroy(struct neighbour *neigh)
 255 {
 256         DPRINTK("clip_neigh_destroy (neigh %p)\n",neigh);
 257         if (NEIGH2ENTRY(neigh)->vccs)
 258                 printk(KERN_CRIT "clip_neigh_destroy: vccs != NULL !!!\n");
 259         NEIGH2ENTRY(neigh)->vccs = (void *) 0xdeadbeef;
 260 }
 261
 262
 263 static void clip_neigh_solicit(struct neighbour *neigh,struct sk_buff *skb)
 264 {
 265         DPRINTK("clip_neigh_solicit (neigh %p, skb %p)\n",neigh,skb);
 266         to_atmarpd(act_need,PRIV(neigh->dev)->number,NEIGH2ENTRY(neigh)->ip);
 267 }
 268
 269
 270 static void clip_neigh_error(struct neighbour *neigh,struct sk_buff *skb)
 271 {
 272 #ifndef CONFIG_ATM_CLIP_NO_ICMP
 273         icmp_send(skb,ICMP_DEST_UNREACH,ICMP_HOST_UNREACH,0);
 274 #endif
 275         kfree_skb(skb);
 276 }
 277
 278
 279 static struct neigh_ops clip_neigh_ops = {
 280         family:                 AF_INET,
 281         destructor:             clip_neigh_destroy,
 282         solicit:                clip_neigh_solicit,
 283         error_report:           clip_neigh_error,
 284         output:                 dev_queue_xmit,
 285         connected_output:       dev_queue_xmit,
 286         hh_output:              dev_queue_xmit,
 287         queue_xmit:             dev_queue_xmit,
 288 };
 289
 290
 291 static int clip_constructor(struct neighbour *neigh)
 292 {
 293         struct atmarp_entry *entry = NEIGH2ENTRY(neigh);
 294         struct net_device *dev = neigh->dev;
 295         struct in_device *in_dev = dev->ip_ptr;
 296
 297         DPRINTK("clip_constructor (neigh %p, entry %p)\n",neigh,entry);
 298         if (!in_dev) return -EINVAL;
 299         neigh->type = inet_addr_type(entry->ip);
 300         if (neigh->type != RTN_UNICAST) return -EINVAL;
 301         if (in_dev->arp_parms) neigh->parms = in_dev->arp_parms;
 302         neigh->ops = &clip_neigh_ops;
 303         neigh->output = neigh->nud_state & NUD_VALID ?
 304             neigh->ops->connected_output : neigh->ops->output;
 305         entry->neigh = neigh;
 306         entry->vccs = NULL;
 307         entry->expires = jiffies-1;
 308         return 0;
 309 }
 310
 311 static u32 clip_hash(const void *pkey, const struct net_device *dev)
 312 {
 313         return jhash_2words(*(u32 *)pkey, dev->ifindex, clip_tbl.hash_rnd);
 314 }
 315
 316
 317 static struct neigh_table clip_tbl = {
 318         NULL,                   /* next */
 319         AF_INET,                /* family */
 320         sizeof(struct neighbour)+sizeof(struct atmarp_entry), /* entry_size */
 321         4,                      /* key_len */
 322         clip_hash,
 323         clip_constructor,       /* constructor */
 324         NULL,                   /* pconstructor */
 325         NULL,                   /* pdestructor */
 326         NULL,                   /* proxy_redo */
 327         "clip_arp_cache",
 328         {                       /* neigh_parms */
 329                 NULL,           /* next */
 330                 NULL,           /* neigh_setup */
 331                 &clip_tbl,      /* tbl */
 332                 0,              /* entries */
 333                 NULL,           /* priv */
 334                 NULL,           /* sysctl_table */
 335                 30*HZ,          /* base_reachable_time */
 336                 1*HZ,           /* retrans_time */
 337                 60*HZ,          /* gc_staletime */
 338                 30*HZ,          /* reachable_time */
 339                 5*HZ,           /* delay_probe_time */
 340                 3,              /* queue_len */
 341                 3,              /* ucast_probes */
 342                 0,              /* app_probes */
 343                 3,              /* mcast_probes */
 344                 1*HZ,           /* anycast_delay */
 345                 (8*HZ)/10,      /* proxy_delay */
 346                 1*HZ,           /* proxy_qlen */
 347                 64              /* locktime */
 348         },
 349         30*HZ,128,512,1024      /* copied from ARP ... */
 350 };
 351
 352
 353 /* @@@ copy bh locking from arp.c -- need to bh-enable atm code before */
 354
 355 /*
 356  * We play with the resolve flag: 0 and 1 have the usual meaning, but -1 means
 357  * to allocate the neighbour entry but not to ask atmarpd for resolution. Also,
 358  * don't increment the usage count. This is used to create entries in
 359  * clip_setentry.
 360  */
 361
 362
 363 static int clip_encap(struct atm_vcc *vcc,int mode)
 364 {
 365         CLIP_VCC(vcc)->encap = mode;
 366         return 0;
 367 }
 368
 369
 370 static int clip_start_xmit(struct sk_buff *skb,struct net_device *dev)
 371 {
 372         struct clip_priv *clip_priv = PRIV(dev);
 373         struct atmarp_entry *entry;
 374         struct atm_vcc *vcc;
 375         int old;
 376         unsigned long flags;
 377
 378         DPRINTK("clip_start_xmit (skb %p)\n",skb);
 379         if (!skb->dst) {
 380                 printk(KERN_ERR "clip_start_xmit: skb->dst == NULL\n");
 381                 dev_kfree_skb(skb);
 382                 clip_priv->stats.tx_dropped++;
 383                 return 0;
 384         }
 385         if (!skb->dst->neighbour) {
 386 #if 0
 387                 skb->dst->neighbour = clip_find_neighbour(skb->dst,1);
 388                 if (!skb->dst->neighbour) {
 389                         dev_kfree_skb(skb); /* lost that one */
 390                         clip_priv->stats.tx_dropped++;
 391                         return 0;
 392                 }
 393 #endif
 394                 printk(KERN_ERR "clip_start_xmit: NO NEIGHBOUR !\n");
 395                 dev_kfree_skb(skb);
 396                 clip_priv->stats.tx_dropped++;
 397                 return 0;
 398         }
 399         entry = NEIGH2ENTRY(skb->dst->neighbour);
 400         if (!entry->vccs) {
 401                 if (time_after(jiffies, entry->expires)) {
 402                         /* should be resolved */
 403                         entry->expires = jiffies+ATMARP_RETRY_DELAY*HZ;
 404                         to_atmarpd(act_need,PRIV(dev)->number,entry->ip);
 405                 }
 406                 if (entry->neigh->arp_queue.qlen < ATMARP_MAX_UNRES_PACKETS)
 407                         skb_queue_tail(&entry->neigh->arp_queue,skb);
 408                 else {
 409                         dev_kfree_skb(skb);
 410                         clip_priv->stats.tx_dropped++;
 411                 }
 412                 return 0;
 413         }
 414         DPRINTK("neigh %p, vccs %p\n",entry,entry->vccs);
 415         ATM_SKB(skb)->vcc = vcc = entry->vccs->vcc;
 416         DPRINTK("using neighbour %p, vcc %p\n",skb->dst->neighbour,vcc);
 417         if (entry->vccs->encap) {
 418                 void *here;
 419
 420                 here = skb_push(skb,RFC1483LLC_LEN);
 421                 memcpy(here,llc_oui,sizeof(llc_oui));
 422                 ((u16 *) here)[3] = skb->protocol;
 423         }
 424         atomic_add(skb->truesize,&vcc->sk->wmem_alloc);
 425         ATM_SKB(skb)->atm_options = vcc->atm_options;
 426         entry->vccs->last_use = jiffies;
 427         DPRINTK("atm_skb(%p)->vcc(%p)->dev(%p)\n",skb,vcc,vcc->dev);
 428         old = xchg(&entry->vccs->xoff,1); /* assume XOFF ... */
 429         if (old) {
 430                 printk(KERN_WARNING "clip_start_xmit: XOFF->XOFF transition\n");
 431                 return 0;
 432         }
 433         clip_priv->stats.tx_packets++;
 434         clip_priv->stats.tx_bytes += skb->len;
 435         (void) vcc->send(vcc,skb);
 436         if (atm_may_send(vcc,0)) {
 437                 entry->vccs->xoff = 0;
 438                 return 0;
 439         }
 440         spin_lock_irqsave(&clip_priv->xoff_lock,flags);
 441         netif_stop_queue(dev); /* XOFF -> throttle immediately */
 442         barrier();
 443         if (!entry->vccs->xoff)
 444                 netif_start_queue(dev);
 445                 /* Oh, we just raced with clip_pop. netif_start_queue should be
 446                    good enough, because nothing should really be asleep because
 447                    of the brief netif_stop_queue. If this isn't true or if it
 448                    changes, use netif_wake_queue instead. */
 449         spin_unlock_irqrestore(&clip_priv->xoff_lock,flags);
 450         return 0;
 451 }
 452
 453
 454 static struct net_device_stats *clip_get_stats(struct net_device *dev)
 455 {
 456         return &PRIV(dev)->stats;
 457 }
 458
 459
 460 static int clip_mkip(struct atm_vcc *vcc,int timeout)
 461 {
 462         struct clip_vcc *clip_vcc;
 463         struct sk_buff_head copy;
 464         struct sk_buff *skb;
 465
 466         if (!vcc->push) return -EBADFD;
 467         clip_vcc = kmalloc(sizeof(struct clip_vcc),GFP_KERNEL);
 468         if (!clip_vcc) return -ENOMEM;
 469         DPRINTK("mkip clip_vcc %p vcc %p\n",clip_vcc,vcc);
 470         clip_vcc->vcc = vcc;
 471         vcc->user_back = clip_vcc;
 472         clip_vcc->entry = NULL;
 473         clip_vcc->xoff = 0;
 474         clip_vcc->encap = 1;
 475         clip_vcc->last_use = jiffies;
 476         clip_vcc->idle_timeout = timeout*HZ;
 477         clip_vcc->old_push = vcc->push;
 478         clip_vcc->old_pop = vcc->pop;
 479         vcc->push = clip_push;
 480         vcc->pop = clip_pop;
 481         skb_queue_head_init(&copy);
 482         skb_migrate(&vcc->sk->receive_queue,&copy);
 483         /* re-process everything received between connection setup and MKIP */
 484         while ((skb = skb_dequeue(&copy)))
 485                 if (!clip_devs) {
 486                         atm_return(vcc,skb->truesize);
 487                         kfree_skb(skb);
 488                 }
 489                 else {
 490                         unsigned int len = skb->len;
 491
 492                         skb_get(skb);
 493                         clip_push(vcc,skb);
 494                         PRIV(skb->dev)->stats.rx_packets--;
 495                         PRIV(skb->dev)->stats.rx_bytes -= len;
 496                         kfree_skb(skb);
 497                 }
 498         return 0;
 499 }
 500
 501
 502 static int clip_setentry(struct atm_vcc *vcc,u32 ip)
 503 {
 504         struct neighbour *neigh;
 505         struct atmarp_entry *entry;
 506         int error;
 507         struct clip_vcc *clip_vcc;
 508         struct rtable *rt;
 509
 510         if (vcc->push != clip_push) {
 511                 printk(KERN_WARNING "clip_setentry: non-CLIP VCC\n");
 512                 return -EBADF;
 513         }
 514         clip_vcc = CLIP_VCC(vcc);
 515         if (!ip) {
 516                 if (!clip_vcc->entry) {
 517                         printk(KERN_ERR "hiding hidden ATMARP entry\n");
 518                         return 0;
 519                 }
 520                 DPRINTK("setentry: remove\n");
 521                 unlink_clip_vcc(clip_vcc);
 522                 return 0;
 523         }
 524         error = ip_route_output(&rt,ip,0,1,0);
 525         if (error) return error;
 526         neigh = __neigh_lookup(&clip_tbl,&ip,rt->u.dst.dev,1);
 527         ip_rt_put(rt);
 528         if (!neigh)
 529                 return -ENOMEM;
 530         entry = NEIGH2ENTRY(neigh);
 531         if (entry != clip_vcc->entry) {
 532                 if (!clip_vcc->entry) DPRINTK("setentry: add\n");
 533                 else {
 534                         DPRINTK("setentry: update\n");
 535                         unlink_clip_vcc(clip_vcc);
 536                 }
 537                 link_vcc(clip_vcc,entry);
 538         }
 539         error = neigh_update(neigh,llc_oui,NUD_PERMANENT,1,0);
 540         neigh_release(neigh);
 541         return error;
 542 }
 543
 544
 545 static int clip_init(struct net_device *dev)
 546 {
 547         DPRINTK("clip_init %s\n",dev->name);
 548         dev->hard_start_xmit = clip_start_xmit;
 549         /* sg_xmit ... */
 550         dev->hard_header = NULL;
 551         dev->rebuild_header = NULL;
 552         dev->set_mac_address = NULL;
 553         dev->hard_header_parse = NULL;
 554         dev->hard_header_cache = NULL;
 555         dev->header_cache_update = NULL;
 556         dev->change_mtu = NULL;
 557         dev->do_ioctl = NULL;
 558         dev->get_stats = clip_get_stats;
 559         dev->type = ARPHRD_ATM;
 560         dev->hard_header_len = RFC1483LLC_LEN;
 561         dev->mtu = RFC1626_MTU;
 562         dev->addr_len = 0;
 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         dev->flags = 0;
 570         return 0;
 571 }
 572
 573
 574 static int clip_create(int number)
 575 {
 576         struct net_device *dev;
 577         struct clip_priv *clip_priv;
 578         int error;
 579
 580         if (number != -1) {
 581                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
 582                         if (PRIV(dev)->number == number) return -EEXIST;
 583         }
 584         else {
 585                 number = 0;
 586                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
 587                         if (PRIV(dev)->number >= number)
 588                                 number = PRIV(dev)->number+1;
 589         }
 590         dev = kmalloc(sizeof(struct net_device)+sizeof(struct clip_priv),
 591             GFP_KERNEL);
 592         if (!dev) return -ENOMEM;
 593         memset(dev,0,sizeof(struct net_device)+sizeof(struct clip_priv));
 594         clip_priv = PRIV(dev);
 595         sprintf(dev->name,"atm%d",number);
 596         dev->init = clip_init;
 597         spin_lock_init(&clip_priv->xoff_lock);
 598         clip_priv->number = number;
 599         error = register_netdev(dev);
 600         if (error) {
 601                 kfree(dev);
 602                 return error;
 603         }
 604         clip_priv->next = clip_devs;
 605         clip_devs = dev;
 606         DPRINTK("registered (net:%s)\n",dev->name);
 607         return number;
 608 }
 609
 610
 611 static int clip_device_event(struct notifier_block *this,unsigned long event,
 612     void *dev)
 613 {
 614         /* ignore non-CLIP devices */
 615         if (((struct net_device *) dev)->type != ARPHRD_ATM ||
 616             ((struct net_device *) dev)->init != clip_init)
 617                 return NOTIFY_DONE;
 618         switch (event) {
 619                 case NETDEV_UP:
 620                         DPRINTK("clip_device_event NETDEV_UP\n");
 621                         (void) to_atmarpd(act_up,PRIV(dev)->number,0);
 622                         break;
 623                 case NETDEV_GOING_DOWN:
 624                         DPRINTK("clip_device_event NETDEV_DOWN\n");
 625                         (void) to_atmarpd(act_down,PRIV(dev)->number,0);
 626                         break;
 627                 case NETDEV_CHANGE:
 628                 case NETDEV_CHANGEMTU:
 629                         DPRINTK("clip_device_event NETDEV_CHANGE*\n");
 630                         (void) to_atmarpd(act_change,PRIV(dev)->number,0);
 631                         break;
 632                 case NETDEV_REBOOT:
 633                 case NETDEV_REGISTER:
 634                 case NETDEV_DOWN:
 635                         DPRINTK("clip_device_event %ld\n",event);
 636                         /* ignore */
 637                         break;
 638                 default:
 639                         printk(KERN_WARNING "clip_device_event: unknown event "
 640                             "%ld\n",event);
 641                         break;
 642         }
 643         return NOTIFY_DONE;
 644 }
 645
 646
 647 static int clip_inet_event(struct notifier_block *this,unsigned long event,
 648     void *ifa)
 649 {
 650         struct in_device *in_dev;
 651
 652         in_dev = ((struct in_ifaddr *) ifa)->ifa_dev;
 653         if (!in_dev || !in_dev->dev) {
 654                 printk(KERN_WARNING "clip_inet_event: no device\n");
 655                 return NOTIFY_DONE;
 656         }
 657         /*
 658          * Transitions are of the down-change-up type, so it's sufficient to
 659          * handle the change on up.
 660          */
 661         if (event != NETDEV_UP) return NOTIFY_DONE;
 662         return clip_device_event(this,NETDEV_CHANGE,in_dev->dev);
 663 }
 664
 665
 666 static struct notifier_block clip_dev_notifier = {
 667         clip_device_event,
 668         NULL,
 669         0
 670 };
 671
 672
 673
 674 static struct notifier_block clip_inet_notifier = {
 675         clip_inet_event,
 676         NULL,
 677         0
 678 };
 679
 680
 681
 682 static void atmarpd_close(struct atm_vcc *vcc)
 683 {
 684         DPRINTK("atmarpd_close\n");
 685         atmarpd = NULL; /* assumed to be atomic */
 686         barrier();
 687         unregister_inetaddr_notifier(&clip_inet_notifier);
 688         unregister_netdevice_notifier(&clip_dev_notifier);
 689         if (skb_peek(&vcc->sk->receive_queue))
 690                 printk(KERN_ERR "atmarpd_close: closing with requests "
 691                     "pending\n");
 692         skb_queue_purge(&vcc->sk->receive_queue);
 693         DPRINTK("(done)\n");
 694         MOD_DEC_USE_COUNT;
 695 }
 696
 697
 698 static struct atmdev_ops atmarpd_dev_ops = {
 699         .close = atmarpd_close,
 700 };
 701
 702
 703 static struct atm_dev atmarpd_dev = {
 704         .ops =          &atmarpd_dev_ops,
 705         .type =         "arpd",
 706         .number =       999,
 707         .lock =         SPIN_LOCK_UNLOCKED
 708 };
 709
 710
 711 static int atm_init_atmarp(struct atm_vcc *vcc)
 712 {
 713         struct net_device *dev;
 714
 715         if (atmarpd) return -EADDRINUSE;
 716         if (start_timer) {
 717                 start_timer = 0;
 718                 init_timer(&idle_timer);
 719                 idle_timer.expires = jiffies+CLIP_CHECK_INTERVAL*HZ;
 720                 idle_timer.function = idle_timer_check;
 721                 add_timer(&idle_timer);
 722         }
 723         atmarpd = vcc;
 724         set_bit(ATM_VF_META,&vcc->flags);
 725         set_bit(ATM_VF_READY,&vcc->flags);
 726             /* allow replies and avoid getting closed if signaling dies */
 727         vcc->dev = &atmarpd_dev;
 728         vcc_insert_socket(vcc->sk);
 729         vcc->push = NULL;
 730         vcc->pop = NULL; /* crash */
 731         vcc->push_oam = NULL; /* crash */
 732         if (register_netdevice_notifier(&clip_dev_notifier))
 733                 printk(KERN_ERR "register_netdevice_notifier failed\n");
 734         if (register_inetaddr_notifier(&clip_inet_notifier))
 735                 printk(KERN_ERR "register_inetaddr_notifier failed\n");
 736         for (dev = clip_devs; dev; dev = PRIV(dev)->next)
 737                 if (dev->flags & IFF_UP)
 738                         (void) to_atmarpd(act_up,PRIV(dev)->number,0);
 739         MOD_INC_USE_COUNT;
 740         return 0;
 741 }
 742
 743 static struct atm_clip_ops __atm_clip_ops = {
 744         .clip_create =          clip_create,
 745         .clip_mkip =            clip_mkip,
 746         .clip_setentry =        clip_setentry,
 747         .clip_encap =           clip_encap,
 748         .clip_push =            clip_push,
 749         .atm_init_atmarp =      atm_init_atmarp,
 750         .owner =                THIS_MODULE
 751 };
 752
 753 static int __init atm_clip_init(void)
 754 {
 755         neigh_table_init(&clip_tbl);
 756
 757         clip_tbl_hook = &clip_tbl;
 758         atm_clip_ops_set(&__atm_clip_ops);
 759
 760         return 0;
 761 }
 762
 763 static void __exit atm_clip_exit(void)
 764 {
 765         struct net_device *dev, *next;
 766
 767         atm_clip_ops_set(NULL);
 768
 769         /* First, stop the idle timer, so it stops banging
 770          * on the table.
 771          */
 772         if (start_timer == 0)
 773                 del_timer(&idle_timer);
 774
 775         /* Next, purge the table, so that the device
 776          * unregister loop below does not hang due to
 777          * device references remaining in the table.
 778          */
 779         neigh_ifdown(&clip_tbl, NULL);
 780
 781         dev = clip_devs;
 782         while (dev) {
 783                 next = PRIV(dev)->next;
 784                 unregister_netdev(dev);
 785                 kfree(dev);
 786                 dev = next;
 787         }
 788
 789         /* Now it is safe to fully shutdown whole table. */
 790         neigh_table_clear(&clip_tbl);
 791
 792         clip_tbl_hook = NULL;
 793 }
 794
 795 module_init(atm_clip_init);
 796 module_exit(atm_clip_exit);
 797
 798 MODULE_LICENSE("GPL");