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
   6 #include <linux/config.h>
   7 #include <linux/string.h>
   8 #include <linux/errno.h>
   9 #include <linux/kernel.h> /* for UINT_MAX */
  10 #include <linux/module.h>
  11 #include <linux/init.h>
  12 #include <linux/netdevice.h>
  13 #include <linux/skbuff.h>
  14 #include <linux/wait.h>
  15 #include <linux/timer.h>
  16 #include <linux/if_arp.h> /* for some manifest constants */
  17 #include <linux/notifier.h>
  18 #include <linux/atm.h>
  19 #include <linux/atmdev.h>
  20 #include <linux/atmclip.h>
  21 #include <linux/atmarp.h>
  22 #include <linux/capability.h>
  23 #include <linux/ip.h> /* for net/route.h */
  24 #include <linux/in.h> /* for struct sockaddr_in */
  25 #include <linux/if.h> /* for IFF_UP */
  26 #include <linux/inetdevice.h>
  27 #include <linux/bitops.h>
  28 #include <linux/proc_fs.h>
  29 #include <linux/seq_file.h>
  30 #include <linux/rcupdate.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 static struct net_device *clip_devs;
  54 static struct atm_vcc *atmarpd;
  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 sock *sk;
  63         struct atmarp_ctrl *ctrl;
  64         struct sk_buff *skb;
  65
  66         DPRINTK("to_atmarpd(%d)\n",type);
  67         if (!atmarpd) return -EUNATCH;
  68         skb = alloc_skb(sizeof(struct atmarp_ctrl),GFP_ATOMIC);
  69         if (!skb) return -ENOMEM;
  70         ctrl = (struct atmarp_ctrl *) skb_put(skb,sizeof(struct atmarp_ctrl));
  71         ctrl->type = type;
  72         ctrl->itf_num = itf;
  73         ctrl->ip = ip;
  74         atm_force_charge(atmarpd,skb->truesize);
  75
  76         sk = sk_atm(atmarpd);
  77         skb_queue_tail(&sk->sk_receive_queue, skb);
  78         sk->sk_data_ready(sk, skb->len);
  79         return 0;
  80 }
  81
  82
  83 static void link_vcc(struct clip_vcc *clip_vcc,struct atmarp_entry *entry)
  84 {
  85         DPRINTK("link_vcc %p to entry %p (neigh %p)\n",clip_vcc,entry,
  86             entry->neigh);
  87         clip_vcc->entry = entry;
  88         clip_vcc->xoff = 0; /* @@@ may overrun buffer by one packet */
  89         clip_vcc->next = entry->vccs;
  90         entry->vccs = clip_vcc;
  91         entry->neigh->used = jiffies;
  92 }
  93
  94
  95 static void unlink_clip_vcc(struct clip_vcc *clip_vcc)
  96 {
  97         struct atmarp_entry *entry = clip_vcc->entry;
  98         struct clip_vcc **walk;
  99
 100         if (!entry) {
 101                 printk(KERN_CRIT "!clip_vcc->entry (clip_vcc %p)\n",clip_vcc);
 102                 return;
 103         }
 104         spin_lock_bh(&entry->neigh->dev->xmit_lock);    /* block clip_start_xmit() */
 105         entry->neigh->used = jiffies;
 106         for (walk = &entry->vccs; *walk; walk = &(*walk)->next)
 107                 if (*walk == clip_vcc) {
 108                         int error;
 109
 110                         *walk = clip_vcc->next; /* atomic */
 111                         clip_vcc->entry = NULL;
 112                         if (clip_vcc->xoff)
 113                                 netif_wake_queue(entry->neigh->dev);
 114                         if (entry->vccs)
 115                                 goto out;
 116                         entry->expires = jiffies-1;
 117                                 /* force resolution or expiration */
 118                         error = neigh_update(entry->neigh, NULL, NUD_NONE,
 119                                              NEIGH_UPDATE_F_ADMIN);
 120                         if (error)
 121                                 printk(KERN_CRIT "unlink_clip_vcc: "
 122                                     "neigh_update failed with %d\n",error);
 123                         goto out;
 124                 }
 125         printk(KERN_CRIT "ATMARP: unlink_clip_vcc failed (entry %p, vcc "
 126           "0x%p)\n",entry,clip_vcc);
 127 out:
 128         spin_unlock_bh(&entry->neigh->dev->xmit_lock);
 129 }
 130
 131 /* The neighbour entry n->lock is held. */
 132 static int neigh_check_cb(struct neighbour *n)
 133 {
 134         struct atmarp_entry *entry = NEIGH2ENTRY(n);
 135         struct clip_vcc *cv;
 136
 137         for (cv = entry->vccs; cv; cv = cv->next) {
 138                 unsigned long exp = cv->last_use + cv->idle_timeout;
 139
 140                 if (cv->idle_timeout && time_after(jiffies, exp)) {
 141                         DPRINTK("releasing vcc %p->%p of entry %p\n",
 142                                 cv, cv->vcc, entry);
 143                         vcc_release_async(cv->vcc, -ETIMEDOUT);
 144                 }
 145         }
 146
 147         if (entry->vccs || time_before(jiffies, entry->expires))
 148                 return 0;
 149
 150         if (atomic_read(&n->refcnt) > 1) {
 151                 struct sk_buff *skb;
 152
 153                 DPRINTK("destruction postponed with ref %d\n",
 154                         atomic_read(&n->refcnt));
 155
 156                 while ((skb = skb_dequeue(&n->arp_queue)) != NULL)
 157                         dev_kfree_skb(skb);
 158
 159                 return 0;
 160         }
 161
 162         DPRINTK("expired neigh %p\n",n);
 163         return 1;
 164 }
 165
 166 static void idle_timer_check(unsigned long dummy)
 167 {
 168         write_lock(&clip_tbl.lock);
 169         __neigh_for_each_release(&clip_tbl, neigh_check_cb);
 170         mod_timer(&idle_timer, jiffies+CLIP_CHECK_INTERVAL*HZ);
 171         write_unlock(&clip_tbl.lock);
 172 }
 173
 174 static int clip_arp_rcv(struct sk_buff *skb)
 175 {
 176         struct atm_vcc *vcc;
 177
 178         DPRINTK("clip_arp_rcv\n");
 179         vcc = ATM_SKB(skb)->vcc;
 180         if (!vcc || !atm_charge(vcc,skb->truesize)) {
 181                 dev_kfree_skb_any(skb);
 182                 return 0;
 183         }
 184         DPRINTK("pushing to %p\n",vcc);
 185         DPRINTK("using %p\n",CLIP_VCC(vcc)->old_push);
 186         CLIP_VCC(vcc)->old_push(vcc,skb);
 187         return 0;
 188 }
 189
 190 static const unsigned char llc_oui[] = {
 191         0xaa,   /* DSAP: non-ISO */
 192         0xaa,   /* SSAP: non-ISO */
 193         0x03,   /* Ctrl: Unnumbered Information Command PDU */
 194         0x00,   /* OUI: EtherType */
 195         0x00,
 196         0x00 };
 197
 198 static void clip_push(struct atm_vcc *vcc,struct sk_buff *skb)
 199 {
 200         struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
 201
 202         DPRINTK("clip push\n");
 203         if (!skb) {
 204                 DPRINTK("removing VCC %p\n",clip_vcc);
 205                 if (clip_vcc->entry) unlink_clip_vcc(clip_vcc);
 206                 clip_vcc->old_push(vcc,NULL); /* pass on the bad news */
 207                 kfree(clip_vcc);
 208                 return;
 209         }
 210         atm_return(vcc,skb->truesize);
 211         skb->dev = clip_vcc->entry ? clip_vcc->entry->neigh->dev : clip_devs;
 212                 /* clip_vcc->entry == NULL if we don't have an IP address yet */
 213         if (!skb->dev) {
 214                 dev_kfree_skb_any(skb);
 215                 return;
 216         }
 217         ATM_SKB(skb)->vcc = vcc;
 218         skb->mac.raw = skb->data;
 219         if (!clip_vcc->encap || skb->len < RFC1483LLC_LEN || memcmp(skb->data,
 220             llc_oui,sizeof(llc_oui))) 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 /*
 240  * Note: these spinlocks _must_not_ block on non-SMP. The only goal is that
 241  * clip_pop is atomic with respect to the critical section in clip_start_xmit.
 242  */
 243
 244
 245 static void clip_pop(struct atm_vcc *vcc,struct sk_buff *skb)
 246 {
 247         struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
 248         struct net_device *dev = skb->dev;
 249         int old;
 250         unsigned long flags;
 251
 252         DPRINTK("clip_pop(vcc %p)\n",vcc);
 253         clip_vcc->old_pop(vcc,skb);
 254         /* skb->dev == NULL in outbound ARP packets */
 255         if (!dev) return;
 256         spin_lock_irqsave(&PRIV(dev)->xoff_lock,flags);
 257         if (atm_may_send(vcc,0)) {
 258                 old = xchg(&clip_vcc->xoff,0);
 259                 if (old) netif_wake_queue(dev);
 260         }
 261         spin_unlock_irqrestore(&PRIV(dev)->xoff_lock,flags);
 262 }
 263
 264
 265 static void clip_neigh_destroy(struct neighbour *neigh)
 266 {
 267         DPRINTK("clip_neigh_destroy (neigh %p)\n",neigh);
 268         if (NEIGH2ENTRY(neigh)->vccs)
 269                 printk(KERN_CRIT "clip_neigh_destroy: vccs != NULL !!!\n");
 270         NEIGH2ENTRY(neigh)->vccs = (void *) 0xdeadbeef;
 271 }
 272
 273
 274 static void clip_neigh_solicit(struct neighbour *neigh,struct sk_buff *skb)
 275 {
 276         DPRINTK("clip_neigh_solicit (neigh %p, skb %p)\n",neigh,skb);
 277         to_atmarpd(act_need,PRIV(neigh->dev)->number,NEIGH2ENTRY(neigh)->ip);
 278 }
 279
 280
 281 static void clip_neigh_error(struct neighbour *neigh,struct sk_buff *skb)
 282 {
 283 #ifndef CONFIG_ATM_CLIP_NO_ICMP
 284         icmp_send(skb,ICMP_DEST_UNREACH,ICMP_HOST_UNREACH,0);
 285 #endif
 286         kfree_skb(skb);
 287 }
 288
 289
 290 static struct neigh_ops clip_neigh_ops = {
 291         .family =               AF_INET,
 292         .destructor =           clip_neigh_destroy,
 293         .solicit =              clip_neigh_solicit,
 294         .error_report =         clip_neigh_error,
 295         .output =               dev_queue_xmit,
 296         .connected_output =     dev_queue_xmit,
 297         .hh_output =            dev_queue_xmit,
 298         .queue_xmit =           dev_queue_xmit,
 299 };
 300
 301
 302 static int clip_constructor(struct neighbour *neigh)
 303 {
 304         struct atmarp_entry *entry = NEIGH2ENTRY(neigh);
 305         struct net_device *dev = neigh->dev;
 306         struct in_device *in_dev;
 307         struct neigh_parms *parms;
 308
 309         DPRINTK("clip_constructor (neigh %p, entry %p)\n",neigh,entry);
 310         neigh->type = inet_addr_type(entry->ip);
 311         if (neigh->type != RTN_UNICAST) return -EINVAL;
 312
 313         rcu_read_lock();
 314         in_dev = __in_dev_get_rcu(dev);
 315         if (!in_dev) {
 316                 rcu_read_unlock();
 317                 return -EINVAL;
 318         }
 319
 320         parms = in_dev->arp_parms;
 321         __neigh_parms_put(neigh->parms);
 322         neigh->parms = neigh_parms_clone(parms);
 323         rcu_read_unlock();
 324
 325         neigh->ops = &clip_neigh_ops;
 326         neigh->output = neigh->nud_state & NUD_VALID ?
 327             neigh->ops->connected_output : neigh->ops->output;
 328         entry->neigh = neigh;
 329         entry->vccs = NULL;
 330         entry->expires = jiffies-1;
 331         return 0;
 332 }
 333
 334 static u32 clip_hash(const void *pkey, const struct net_device *dev)
 335 {
 336         return jhash_2words(*(u32 *)pkey, dev->ifindex, clip_tbl.hash_rnd);
 337 }
 338
 339 static struct neigh_table clip_tbl = {
 340         .family         = AF_INET,
 341         .entry_size     = sizeof(struct neighbour)+sizeof(struct atmarp_entry),
 342         .key_len        = 4,
 343         .hash           = clip_hash,
 344         .constructor    = clip_constructor,
 345         .id             = "clip_arp_cache",
 346
 347         /* parameters are copied from ARP ... */
 348         .parms = {
 349                 .tbl                    = &clip_tbl,
 350                 .base_reachable_time    = 30 * HZ,
 351                 .retrans_time           = 1 * HZ,
 352                 .gc_staletime           = 60 * HZ,
 353                 .reachable_time         = 30 * HZ,
 354                 .delay_probe_time       = 5 * HZ,
 355                 .queue_len              = 3,
 356                 .ucast_probes           = 3,
 357                 .mcast_probes           = 3,
 358                 .anycast_delay          = 1 * HZ,
 359                 .proxy_delay            = (8 * HZ) / 10,
 360                 .proxy_qlen             = 64,
 361                 .locktime               = 1 * HZ,
 362         },
 363         .gc_interval    = 30 * HZ,
 364         .gc_thresh1     = 128,
 365         .gc_thresh2     = 512,
 366         .gc_thresh3     = 1024,
 367 };
 368
 369
 370 /* @@@ copy bh locking from arp.c -- need to bh-enable atm code before */
 371
 372 /*
 373  * We play with the resolve flag: 0 and 1 have the usual meaning, but -1 means
 374  * to allocate the neighbour entry but not to ask atmarpd for resolution. Also,
 375  * don't increment the usage count. This is used to create entries in
 376  * clip_setentry.
 377  */
 378
 379
 380 static int clip_encap(struct atm_vcc *vcc,int mode)
 381 {
 382         CLIP_VCC(vcc)->encap = mode;
 383         return 0;
 384 }
 385
 386
 387 static int clip_start_xmit(struct sk_buff *skb,struct net_device *dev)
 388 {
 389         struct clip_priv *clip_priv = PRIV(dev);
 390         struct atmarp_entry *entry;
 391         struct atm_vcc *vcc;
 392         int old;
 393         unsigned long flags;
 394
 395         DPRINTK("clip_start_xmit (skb %p)\n",skb);
 396         if (!skb->dst) {
 397                 printk(KERN_ERR "clip_start_xmit: skb->dst == NULL\n");
 398                 dev_kfree_skb(skb);
 399                 clip_priv->stats.tx_dropped++;
 400                 return 0;
 401         }
 402         if (!skb->dst->neighbour) {
 403 #if 0
 404                 skb->dst->neighbour = clip_find_neighbour(skb->dst,1);
 405                 if (!skb->dst->neighbour) {
 406                         dev_kfree_skb(skb); /* lost that one */
 407                         clip_priv->stats.tx_dropped++;
 408                         return 0;
 409                 }
 410 #endif
 411                 printk(KERN_ERR "clip_start_xmit: NO NEIGHBOUR !\n");
 412                 dev_kfree_skb(skb);
 413                 clip_priv->stats.tx_dropped++;
 414                 return 0;
 415         }
 416         entry = NEIGH2ENTRY(skb->dst->neighbour);
 417         if (!entry->vccs) {
 418                 if (time_after(jiffies, entry->expires)) {
 419                         /* should be resolved */
 420                         entry->expires = jiffies+ATMARP_RETRY_DELAY*HZ;
 421                         to_atmarpd(act_need,PRIV(dev)->number,entry->ip);
 422                 }
 423                 if (entry->neigh->arp_queue.qlen < ATMARP_MAX_UNRES_PACKETS)
 424                         skb_queue_tail(&entry->neigh->arp_queue,skb);
 425                 else {
 426                         dev_kfree_skb(skb);
 427                         clip_priv->stats.tx_dropped++;
 428                 }
 429                 return 0;
 430         }
 431         DPRINTK("neigh %p, vccs %p\n",entry,entry->vccs);
 432         ATM_SKB(skb)->vcc = vcc = entry->vccs->vcc;
 433         DPRINTK("using neighbour %p, vcc %p\n",skb->dst->neighbour,vcc);
 434         if (entry->vccs->encap) {
 435                 void *here;
 436
 437                 here = skb_push(skb,RFC1483LLC_LEN);
 438                 memcpy(here,llc_oui,sizeof(llc_oui));
 439                 ((u16 *) here)[3] = skb->protocol;
 440         }
 441         atomic_add(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
 442         ATM_SKB(skb)->atm_options = vcc->atm_options;
 443         entry->vccs->last_use = jiffies;
 444         DPRINTK("atm_skb(%p)->vcc(%p)->dev(%p)\n",skb,vcc,vcc->dev);
 445         old = xchg(&entry->vccs->xoff,1); /* assume XOFF ... */
 446         if (old) {
 447                 printk(KERN_WARNING "clip_start_xmit: XOFF->XOFF transition\n");
 448                 return 0;
 449         }
 450         clip_priv->stats.tx_packets++;
 451         clip_priv->stats.tx_bytes += skb->len;
 452         (void) vcc->send(vcc,skb);
 453         if (atm_may_send(vcc,0)) {
 454                 entry->vccs->xoff = 0;
 455                 return 0;
 456         }
 457         spin_lock_irqsave(&clip_priv->xoff_lock,flags);
 458         netif_stop_queue(dev); /* XOFF -> throttle immediately */
 459         barrier();
 460         if (!entry->vccs->xoff)
 461                 netif_start_queue(dev);
 462                 /* Oh, we just raced with clip_pop. netif_start_queue should be
 463                    good enough, because nothing should really be asleep because
 464                    of the brief netif_stop_queue. If this isn't true or if it
 465                    changes, use netif_wake_queue instead. */
 466         spin_unlock_irqrestore(&clip_priv->xoff_lock,flags);
 467         return 0;
 468 }
 469
 470
 471 static struct net_device_stats *clip_get_stats(struct net_device *dev)
 472 {
 473         return &PRIV(dev)->stats;
 474 }
 475
 476
 477 static int clip_mkip(struct atm_vcc *vcc,int timeout)
 478 {
 479         struct clip_vcc *clip_vcc;
 480         struct sk_buff_head copy;
 481         struct sk_buff *skb;
 482
 483         if (!vcc->push) return -EBADFD;
 484         clip_vcc = kmalloc(sizeof(struct clip_vcc),GFP_KERNEL);
 485         if (!clip_vcc) return -ENOMEM;
 486         DPRINTK("mkip clip_vcc %p vcc %p\n",clip_vcc,vcc);
 487         clip_vcc->vcc = vcc;
 488         vcc->user_back = clip_vcc;
 489         set_bit(ATM_VF_IS_CLIP, &vcc->flags);
 490         clip_vcc->entry = NULL;
 491         clip_vcc->xoff = 0;
 492         clip_vcc->encap = 1;
 493         clip_vcc->last_use = jiffies;
 494         clip_vcc->idle_timeout = timeout*HZ;
 495         clip_vcc->old_push = vcc->push;
 496         clip_vcc->old_pop = vcc->pop;
 497         vcc->push = clip_push;
 498         vcc->pop = clip_pop;
 499         skb_queue_head_init(&copy);
 500         skb_migrate(&sk_atm(vcc)->sk_receive_queue, &copy);
 501         /* re-process everything received between connection setup and MKIP */
 502         while ((skb = skb_dequeue(&copy)) != NULL)
 503                 if (!clip_devs) {
 504                         atm_return(vcc,skb->truesize);
 505                         kfree_skb(skb);
 506                 }
 507                 else {
 508                         unsigned int len = skb->len;
 509
 510                         skb_get(skb);
 511                         clip_push(vcc,skb);
 512                         PRIV(skb->dev)->stats.rx_packets--;
 513                         PRIV(skb->dev)->stats.rx_bytes -= len;
 514                         kfree_skb(skb);
 515                 }
 516         return 0;
 517 }
 518
 519
 520 static int clip_setentry(struct atm_vcc *vcc,u32 ip)
 521 {
 522         struct neighbour *neigh;
 523         struct atmarp_entry *entry;
 524         int error;
 525         struct clip_vcc *clip_vcc;
 526         struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, .tos = 1 } } };
 527         struct rtable *rt;
 528
 529         if (vcc->push != clip_push) {
 530                 printk(KERN_WARNING "clip_setentry: non-CLIP VCC\n");
 531                 return -EBADF;
 532         }
 533         clip_vcc = CLIP_VCC(vcc);
 534         if (!ip) {
 535                 if (!clip_vcc->entry) {
 536                         printk(KERN_ERR "hiding hidden ATMARP entry\n");
 537                         return 0;
 538                 }
 539                 DPRINTK("setentry: remove\n");
 540                 unlink_clip_vcc(clip_vcc);
 541                 return 0;
 542         }
 543         error = ip_route_output_key(&rt,&fl);
 544         if (error) return error;
 545         neigh = __neigh_lookup(&clip_tbl,&ip,rt->u.dst.dev,1);
 546         ip_rt_put(rt);
 547         if (!neigh)
 548                 return -ENOMEM;
 549         entry = NEIGH2ENTRY(neigh);
 550         if (entry != clip_vcc->entry) {
 551                 if (!clip_vcc->entry) DPRINTK("setentry: add\n");
 552                 else {
 553                         DPRINTK("setentry: update\n");
 554                         unlink_clip_vcc(clip_vcc);
 555                 }
 556                 link_vcc(clip_vcc,entry);
 557         }
 558         error = neigh_update(neigh, llc_oui, NUD_PERMANENT,
 559                              NEIGH_UPDATE_F_OVERRIDE|NEIGH_UPDATE_F_ADMIN);
 560         neigh_release(neigh);
 561         return error;
 562 }
 563
 564
 565 static void clip_setup(struct net_device *dev)
 566 {
 567         dev->hard_start_xmit = clip_start_xmit;
 568         /* sg_xmit ... */
 569         dev->get_stats = clip_get_stats;
 570         dev->type = ARPHRD_ATM;
 571         dev->hard_header_len = RFC1483LLC_LEN;
 572         dev->mtu = RFC1626_MTU;
 573         dev->tx_queue_len = 100; /* "normal" queue (packets) */
 574             /* When using a "real" qdisc, the qdisc determines the queue */
 575             /* length. tx_queue_len is only used for the default case, */
 576             /* without any more elaborate queuing. 100 is a reasonable */
 577             /* compromise between decent burst-tolerance and protection */
 578             /* against memory hogs. */
 579 }
 580
 581
 582 static int clip_create(int number)
 583 {
 584         struct net_device *dev;
 585         struct clip_priv *clip_priv;
 586         int error;
 587
 588         if (number != -1) {
 589                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
 590                         if (PRIV(dev)->number == number) return -EEXIST;
 591         }
 592         else {
 593                 number = 0;
 594                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
 595                         if (PRIV(dev)->number >= number)
 596                                 number = PRIV(dev)->number+1;
 597         }
 598         dev = alloc_netdev(sizeof(struct clip_priv), "", clip_setup);
 599         if (!dev)
 600                 return -ENOMEM;
 601         clip_priv = PRIV(dev);
 602         sprintf(dev->name,"atm%d",number);
 603         spin_lock_init(&clip_priv->xoff_lock);
 604         clip_priv->number = number;
 605         error = register_netdev(dev);
 606         if (error) {
 607                 free_netdev(dev);
 608                 return error;
 609         }
 610         clip_priv->next = clip_devs;
 611         clip_devs = dev;
 612         DPRINTK("registered (net:%s)\n",dev->name);
 613         return number;
 614 }
 615
 616
 617 static int clip_device_event(struct notifier_block *this,unsigned long event,
 618                              void *arg)
 619 {
 620         struct net_device *dev = arg;
 621
 622         if (event == NETDEV_UNREGISTER) {
 623                 neigh_ifdown(&clip_tbl, dev);
 624                 return NOTIFY_DONE;
 625         }
 626
 627         /* ignore non-CLIP devices */
 628         if (dev->type != ARPHRD_ATM || dev->hard_start_xmit != clip_start_xmit)
 629                 return NOTIFY_DONE;
 630
 631         switch (event) {
 632                 case NETDEV_UP:
 633                         DPRINTK("clip_device_event NETDEV_UP\n");
 634                         (void) to_atmarpd(act_up,PRIV(dev)->number,0);
 635                         break;
 636                 case NETDEV_GOING_DOWN:
 637                         DPRINTK("clip_device_event NETDEV_DOWN\n");
 638                         (void) to_atmarpd(act_down,PRIV(dev)->number,0);
 639                         break;
 640                 case NETDEV_CHANGE:
 641                 case NETDEV_CHANGEMTU:
 642                         DPRINTK("clip_device_event NETDEV_CHANGE*\n");
 643                         (void) to_atmarpd(act_change,PRIV(dev)->number,0);
 644                         break;
 645                 case NETDEV_REBOOT:
 646                 case NETDEV_REGISTER:
 647                 case NETDEV_DOWN:
 648                         DPRINTK("clip_device_event %ld\n",event);
 649                         /* ignore */
 650                         break;
 651                 default:
 652                         printk(KERN_WARNING "clip_device_event: unknown event "
 653                             "%ld\n",event);
 654                         break;
 655         }
 656         return NOTIFY_DONE;
 657 }
 658
 659
 660 static int clip_inet_event(struct notifier_block *this,unsigned long event,
 661     void *ifa)
 662 {
 663         struct in_device *in_dev;
 664
 665         in_dev = ((struct in_ifaddr *) ifa)->ifa_dev;
 666         if (!in_dev || !in_dev->dev) {
 667                 printk(KERN_WARNING "clip_inet_event: no device\n");
 668                 return NOTIFY_DONE;
 669         }
 670         /*
 671          * Transitions are of the down-change-up type, so it's sufficient to
 672          * handle the change on up.
 673          */
 674         if (event != NETDEV_UP) 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         clip_device_event,
 681         NULL,
 682         0
 683 };
 684
 685
 686
 687 static struct notifier_block clip_inet_notifier = {
 688         clip_inet_event,
 689         NULL,
 690         0
 691 };
 692
 693
 694
 695 static void atmarpd_close(struct atm_vcc *vcc)
 696 {
 697         DPRINTK("atmarpd_close\n");
 698
 699         rtnl_lock();
 700         atmarpd = NULL;
 701         skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
 702         rtnl_unlock();
 703
 704         DPRINTK("(done)\n");
 705         module_put(THIS_MODULE);
 706 }
 707
 708
 709 static struct atmdev_ops atmarpd_dev_ops = {
 710         .close = atmarpd_close
 711 };
 712
 713
 714 static struct atm_dev atmarpd_dev = {
 715         .ops =                  &atmarpd_dev_ops,
 716         .type =                 "arpd",
 717         .number =               999,
 718         .lock =                 SPIN_LOCK_UNLOCKED
 719 };
 720
 721
 722 static int atm_init_atmarp(struct atm_vcc *vcc)
 723 {
 724         rtnl_lock();
 725         if (atmarpd) {
 726                 rtnl_unlock();
 727                 return -EADDRINUSE;
 728         }
 729
 730         if (start_timer) {
 731                 start_timer = 0;
 732                 init_timer(&idle_timer);
 733                 idle_timer.expires = jiffies+CLIP_CHECK_INTERVAL*HZ;
 734                 idle_timer.function = idle_timer_check;
 735                 add_timer(&idle_timer);
 736         }
 737         atmarpd = vcc;
 738         set_bit(ATM_VF_META,&vcc->flags);
 739         set_bit(ATM_VF_READY,&vcc->flags);
 740             /* allow replies and avoid getting closed if signaling dies */
 741         vcc->dev = &atmarpd_dev;
 742         vcc_insert_socket(sk_atm(vcc));
 743         vcc->push = NULL;
 744         vcc->pop = NULL; /* crash */
 745         vcc->push_oam = NULL; /* crash */
 746         rtnl_unlock();
 747         return 0;
 748 }
 749
 750 static int clip_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 751 {
 752         struct atm_vcc *vcc = ATM_SD(sock);
 753         int err = 0;
 754
 755         switch (cmd) {
 756                 case SIOCMKCLIP:
 757                 case ATMARPD_CTRL:
 758                 case ATMARP_MKIP:
 759                 case ATMARP_SETENTRY:
 760                 case ATMARP_ENCAP:
 761                         if (!capable(CAP_NET_ADMIN))
 762                                 return -EPERM;
 763                         break;
 764                 default:
 765                         return -ENOIOCTLCMD;
 766         }
 767
 768         switch (cmd) {
 769                 case SIOCMKCLIP:
 770                         err = clip_create(arg);
 771                         break;
 772                 case ATMARPD_CTRL:
 773                         err = atm_init_atmarp(vcc);
 774                         if (!err) {
 775                                 sock->state = SS_CONNECTED;
 776                                 __module_get(THIS_MODULE);
 777                         }
 778                         break;
 779                 case ATMARP_MKIP:
 780                         err = clip_mkip(vcc ,arg);
 781                         break;
 782                 case ATMARP_SETENTRY:
 783                         err = clip_setentry(vcc, arg);
 784                         break;
 785                 case ATMARP_ENCAP:
 786                         err = clip_encap(vcc, arg);
 787                         break;
 788         }
 789         return err;
 790 }
 791
 792 static struct atm_ioctl clip_ioctl_ops = {
 793         .owner  = THIS_MODULE,
 794         .ioctl  = clip_ioctl,
 795 };
 796
 797 #ifdef CONFIG_PROC_FS
 798
 799 static void svc_addr(struct seq_file *seq, struct sockaddr_atmsvc *addr)
 800 {
 801         static int code[] = { 1,2,10,6,1,0 };
 802         static int e164[] = { 1,8,4,6,1,0 };
 803
 804         if (*addr->sas_addr.pub) {
 805                 seq_printf(seq, "%s", addr->sas_addr.pub);
 806                 if (*addr->sas_addr.prv)
 807                         seq_putc(seq, '+');
 808         } else if (!*addr->sas_addr.prv) {
 809                 seq_printf(seq, "%s", "(none)");
 810                 return;
 811         }
 812         if (*addr->sas_addr.prv) {
 813                 unsigned char *prv = addr->sas_addr.prv;
 814                 int *fields;
 815                 int i, j;
 816
 817                 fields = *prv == ATM_AFI_E164 ? e164 : code;
 818                 for (i = 0; fields[i]; i++) {
 819                         for (j = fields[i]; j; j--)
 820                                 seq_printf(seq, "%02X", *prv++);
 821                         if (fields[i+1])
 822                                 seq_putc(seq, '.');
 823                 }
 824         }
 825 }
 826
 827 /* This means the neighbour entry has no attached VCC objects. */
 828 #define SEQ_NO_VCC_TOKEN        ((void *) 2)
 829
 830 static void atmarp_info(struct seq_file *seq, struct net_device *dev,
 831                         struct atmarp_entry *entry, struct clip_vcc *clip_vcc)
 832 {
 833         unsigned long exp;
 834         char buf[17];
 835         int svc, llc, off;
 836
 837         svc = ((clip_vcc == SEQ_NO_VCC_TOKEN) ||
 838                (sk_atm(clip_vcc->vcc)->sk_family == AF_ATMSVC));
 839
 840         llc = ((clip_vcc == SEQ_NO_VCC_TOKEN) ||
 841                clip_vcc->encap);
 842
 843         if (clip_vcc == SEQ_NO_VCC_TOKEN)
 844                 exp = entry->neigh->used;
 845         else
 846                 exp = clip_vcc->last_use;
 847
 848         exp = (jiffies - exp) / HZ;
 849
 850         seq_printf(seq, "%-6s%-4s%-4s%5ld ",
 851                    dev->name,
 852                    svc ? "SVC" : "PVC",
 853                    llc ? "LLC" : "NULL",
 854                    exp);
 855
 856         off = scnprintf(buf, sizeof(buf) - 1, "%d.%d.%d.%d",
 857                         NIPQUAD(entry->ip));
 858         while (off < 16)
 859                 buf[off++] = ' ';
 860         buf[off] = '\0';
 861         seq_printf(seq, "%s", buf);
 862
 863         if (clip_vcc == SEQ_NO_VCC_TOKEN) {
 864                 if (time_before(jiffies, entry->expires))
 865                         seq_printf(seq, "(resolving)\n");
 866                 else
 867                         seq_printf(seq, "(expired, ref %d)\n",
 868                                    atomic_read(&entry->neigh->refcnt));
 869         } else if (!svc) {
 870                 seq_printf(seq, "%d.%d.%d\n",
 871                            clip_vcc->vcc->dev->number,
 872                            clip_vcc->vcc->vpi,
 873                            clip_vcc->vcc->vci);
 874         } else {
 875                 svc_addr(seq, &clip_vcc->vcc->remote);
 876                 seq_putc(seq, '\n');
 877         }
 878 }
 879
 880 struct clip_seq_state {
 881         /* This member must be first. */
 882         struct neigh_seq_state ns;
 883
 884         /* Local to clip specific iteration. */
 885         struct clip_vcc *vcc;
 886 };
 887
 888 static struct clip_vcc *clip_seq_next_vcc(struct atmarp_entry *e,
 889                                           struct clip_vcc *curr)
 890 {
 891         if (!curr) {
 892                 curr = e->vccs;
 893                 if (!curr)
 894                         return SEQ_NO_VCC_TOKEN;
 895                 return curr;
 896         }
 897         if (curr == SEQ_NO_VCC_TOKEN)
 898                 return NULL;
 899
 900         curr = curr->next;
 901
 902         return curr;
 903 }
 904
 905 static void *clip_seq_vcc_walk(struct clip_seq_state *state,
 906                                struct atmarp_entry *e, loff_t *pos)
 907 {
 908         struct clip_vcc *vcc = state->vcc;
 909
 910         vcc = clip_seq_next_vcc(e, vcc);
 911         if (vcc && pos != NULL) {
 912                 while (*pos) {
 913                         vcc = clip_seq_next_vcc(e, vcc);
 914                         if (!vcc)
 915                                 break;
 916                         --(*pos);
 917                 }
 918         }
 919         state->vcc = vcc;
 920
 921         return vcc;
 922 }
 923
 924 static void *clip_seq_sub_iter(struct neigh_seq_state *_state,
 925                                struct neighbour *n, loff_t *pos)
 926 {
 927         struct clip_seq_state *state = (struct clip_seq_state *) _state;
 928
 929         return clip_seq_vcc_walk(state, NEIGH2ENTRY(n), pos);
 930 }
 931
 932 static void *clip_seq_start(struct seq_file *seq, loff_t *pos)
 933 {
 934         return neigh_seq_start(seq, pos, &clip_tbl, NEIGH_SEQ_NEIGH_ONLY);
 935 }
 936
 937 static int clip_seq_show(struct seq_file *seq, void *v)
 938 {
 939         static char atm_arp_banner[] =
 940                 "IPitf TypeEncp Idle IP address      ATM address\n";
 941
 942         if (v == SEQ_START_TOKEN) {
 943                 seq_puts(seq, atm_arp_banner);
 944         } else {
 945                 struct clip_seq_state *state = seq->private;
 946                 struct neighbour *n = v;
 947                 struct clip_vcc *vcc = state->vcc;
 948
 949                 atmarp_info(seq, n->dev, NEIGH2ENTRY(n), vcc);
 950         }
 951         return 0;
 952 }
 953
 954 static struct seq_operations arp_seq_ops = {
 955         .start  = clip_seq_start,
 956         .next   = neigh_seq_next,
 957         .stop   = neigh_seq_stop,
 958         .show   = clip_seq_show,
 959 };
 960
 961 static int arp_seq_open(struct inode *inode, struct file *file)
 962 {
 963         struct clip_seq_state *state;
 964         struct seq_file *seq;
 965         int rc = -EAGAIN;
 966
 967         state = kmalloc(sizeof(*state), GFP_KERNEL);
 968         if (!state) {
 969                 rc = -ENOMEM;
 970                 goto out_kfree;
 971         }
 972         memset(state, 0, sizeof(*state));
 973         state->ns.neigh_sub_iter = clip_seq_sub_iter;
 974
 975         rc = seq_open(file, &arp_seq_ops);
 976         if (rc)
 977                 goto out_kfree;
 978
 979         seq = file->private_data;
 980         seq->private = state;
 981 out:
 982         return rc;
 983
 984 out_kfree:
 985         kfree(state);
 986         goto out;
 987 }
 988
 989 static struct file_operations arp_seq_fops = {
 990         .open           = arp_seq_open,
 991         .read           = seq_read,
 992         .llseek         = seq_lseek,
 993         .release        = seq_release_private,
 994         .owner          = THIS_MODULE
 995 };
 996 #endif
 997
 998 static int __init atm_clip_init(void)
 999 {
1000         neigh_table_init(&clip_tbl);
1001
1002         clip_tbl_hook = &clip_tbl;
1003         register_atm_ioctl(&clip_ioctl_ops);
1004         register_netdevice_notifier(&clip_dev_notifier);
1005         register_inetaddr_notifier(&clip_inet_notifier);
1006
1007 #ifdef CONFIG_PROC_FS
1008 {
1009         struct proc_dir_entry *p;
1010
1011         p = create_proc_entry("arp", S_IRUGO, atm_proc_root);
1012         if (p)
1013                 p->proc_fops = &arp_seq_fops;
1014 }
1015 #endif
1016
1017         return 0;
1018 }
1019
1020 static void __exit atm_clip_exit(void)
1021 {
1022         struct net_device *dev, *next;
1023
1024         remove_proc_entry("arp", atm_proc_root);
1025
1026         unregister_inetaddr_notifier(&clip_inet_notifier);
1027         unregister_netdevice_notifier(&clip_dev_notifier);
1028
1029         deregister_atm_ioctl(&clip_ioctl_ops);
1030
1031         /* First, stop the idle timer, so it stops banging
1032          * on the table.
1033          */
1034         if (start_timer == 0)
1035                 del_timer(&idle_timer);
1036
1037         /* Next, purge the table, so that the device
1038          * unregister loop below does not hang due to
1039          * device references remaining in the table.
1040          */
1041         neigh_ifdown(&clip_tbl, NULL);
1042
1043         dev = clip_devs;
1044         while (dev) {
1045                 next = PRIV(dev)->next;
1046                 unregister_netdev(dev);
1047                 free_netdev(dev);
1048                 dev = next;
1049         }
1050
1051         /* Now it is safe to fully shutdown whole table. */
1052         neigh_table_clear(&clip_tbl);
1053
1054         clip_tbl_hook = NULL;
1055 }
1056
1057 module_init(atm_clip_init);
1058 module_exit(atm_clip_exit);
1059
1060 MODULE_LICENSE("GPL");