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/ip.h> /* for net/route.h */
  23 #include <linux/in.h> /* for struct sockaddr_in */
  24 #include <linux/if.h> /* for IFF_UP */
  25 #include <linux/inetdevice.h>
  26 #include <linux/bitops.h>
  27 #include <linux/proc_fs.h>
  28 #include <linux/seq_file.h>
  29 #include <linux/rcupdate.h>
  30 #include <linux/jhash.h>
  31 #include <net/route.h> /* for struct rtable and routing */
  32 #include <net/icmp.h> /* icmp_send */
  33 #include <asm/param.h> /* for HZ */
  34 #include <asm/byteorder.h> /* for htons etc. */
  35 #include <asm/system.h> /* save/restore_flags */
  36 #include <asm/uaccess.h>
  37 #include <asm/atomic.h>
  38
  39 #include "common.h"
  40 #include "resources.h"
  41 #include "ipcommon.h"
  42 #include <net/atmclip.h>
  43
  44
  45 #if 0
  46 #define DPRINTK(format,args...) printk(format,##args)
  47 #else
  48 #define DPRINTK(format,args...)
  49 #endif
  50
  51
  52 static struct net_device *clip_devs;
  53 static struct atm_vcc *atmarpd;
  54 static struct neigh_table clip_tbl;
  55 static struct timer_list idle_timer;
  56 static int start_timer = 1;
  57
  58
  59 static int to_atmarpd(enum atmarp_ctrl_type type,int itf,unsigned long ip)
  60 {
  61         struct atmarp_ctrl *ctrl;
  62         struct sk_buff *skb;
  63
  64         DPRINTK("to_atmarpd(%d)\n",type);
  65         if (!atmarpd) return -EUNATCH;
  66         skb = alloc_skb(sizeof(struct atmarp_ctrl),GFP_ATOMIC);
  67         if (!skb) 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         skb_queue_tail(&atmarpd->sk->sk_receive_queue, skb);
  74         atmarpd->sk->sk_data_ready(atmarpd->sk, skb->len);
  75         return 0;
  76 }
  77
  78
  79 static void link_vcc(struct clip_vcc *clip_vcc,struct atmarp_entry *entry)
  80 {
  81         DPRINTK("link_vcc %p to entry %p (neigh %p)\n",clip_vcc,entry,
  82             entry->neigh);
  83         clip_vcc->entry = entry;
  84         clip_vcc->xoff = 0; /* @@@ may overrun buffer by one packet */
  85         clip_vcc->next = entry->vccs;
  86         entry->vccs = clip_vcc;
  87         entry->neigh->used = jiffies;
  88 }
  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         spin_lock_bh(&entry->neigh->dev->xmit_lock);    /* 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         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 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 static void clip_push(struct atm_vcc *vcc,struct sk_buff *skb)
 195 {
 196         struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
 197
 198         DPRINTK("clip push\n");
 199         if (!skb) {
 200                 DPRINTK("removing VCC %p\n",clip_vcc);
 201                 if (clip_vcc->entry) unlink_clip_vcc(clip_vcc);
 202                 clip_vcc->old_push(vcc,NULL); /* pass on the bad news */
 203                 kfree(clip_vcc);
 204                 return;
 205         }
 206         atm_return(vcc,skb->truesize);
 207         skb->dev = clip_vcc->entry ? clip_vcc->entry->neigh->dev : clip_devs;
 208                 /* clip_vcc->entry == NULL if we don't have an IP address yet */
 209         if (!skb->dev) {
 210                 dev_kfree_skb_any(skb);
 211                 return;
 212         }
 213         ATM_SKB(skb)->vcc = vcc;
 214         skb->mac.raw = skb->data;
 215         if (!clip_vcc->encap || skb->len < RFC1483LLC_LEN || memcmp(skb->data,
 216             llc_oui,sizeof(llc_oui))) skb->protocol = htons(ETH_P_IP);
 217         else {
 218                 skb->protocol = ((u16 *) skb->data)[3];
 219                 skb_pull(skb,RFC1483LLC_LEN);
 220                 if (skb->protocol == htons(ETH_P_ARP)) {
 221                         PRIV(skb->dev)->stats.rx_packets++;
 222                         PRIV(skb->dev)->stats.rx_bytes += skb->len;
 223                         clip_arp_rcv(skb);
 224                         return;
 225                 }
 226         }
 227         clip_vcc->last_use = jiffies;
 228         PRIV(skb->dev)->stats.rx_packets++;
 229         PRIV(skb->dev)->stats.rx_bytes += skb->len;
 230         memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
 231         netif_rx(skb);
 232 }
 233
 234
 235 /*
 236  * Note: these spinlocks _must_not_ block on non-SMP. The only goal is that
 237  * clip_pop is atomic with respect to the critical section in clip_start_xmit.
 238  */
 239
 240
 241 static void clip_pop(struct atm_vcc *vcc,struct sk_buff *skb)
 242 {
 243         struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
 244         struct net_device *dev = skb->dev;
 245         int old;
 246         unsigned long flags;
 247
 248         DPRINTK("clip_pop(vcc %p)\n",vcc);
 249         clip_vcc->old_pop(vcc,skb);
 250         /* skb->dev == NULL in outbound ARP packets */
 251         if (!dev) return;
 252         spin_lock_irqsave(&PRIV(dev)->xoff_lock,flags);
 253         if (atm_may_send(vcc,0)) {
 254                 old = xchg(&clip_vcc->xoff,0);
 255                 if (old) netif_wake_queue(dev);
 256         }
 257         spin_unlock_irqrestore(&PRIV(dev)->xoff_lock,flags);
 258 }
 259
 260
 261 static void clip_neigh_destroy(struct neighbour *neigh)
 262 {
 263         DPRINTK("clip_neigh_destroy (neigh %p)\n",neigh);
 264         if (NEIGH2ENTRY(neigh)->vccs)
 265                 printk(KERN_CRIT "clip_neigh_destroy: vccs != NULL !!!\n");
 266         NEIGH2ENTRY(neigh)->vccs = (void *) 0xdeadbeef;
 267 }
 268
 269
 270 static void clip_neigh_solicit(struct neighbour *neigh,struct sk_buff *skb)
 271 {
 272         DPRINTK("clip_neigh_solicit (neigh %p, skb %p)\n",neigh,skb);
 273         to_atmarpd(act_need,PRIV(neigh->dev)->number,NEIGH2ENTRY(neigh)->ip);
 274 }
 275
 276
 277 static void clip_neigh_error(struct neighbour *neigh,struct sk_buff *skb)
 278 {
 279 #ifndef CONFIG_ATM_CLIP_NO_ICMP
 280         icmp_send(skb,ICMP_DEST_UNREACH,ICMP_HOST_UNREACH,0);
 281 #endif
 282         kfree_skb(skb);
 283 }
 284
 285
 286 static struct neigh_ops clip_neigh_ops = {
 287         .family =               AF_INET,
 288         .destructor =           clip_neigh_destroy,
 289         .solicit =              clip_neigh_solicit,
 290         .error_report =         clip_neigh_error,
 291         .output =               dev_queue_xmit,
 292         .connected_output =     dev_queue_xmit,
 293         .hh_output =            dev_queue_xmit,
 294         .queue_xmit =           dev_queue_xmit,
 295 };
 296
 297
 298 static int clip_constructor(struct neighbour *neigh)
 299 {
 300         struct atmarp_entry *entry = NEIGH2ENTRY(neigh);
 301         struct net_device *dev = neigh->dev;
 302         struct in_device *in_dev;
 303         struct neigh_parms *parms;
 304
 305         DPRINTK("clip_constructor (neigh %p, entry %p)\n",neigh,entry);
 306         neigh->type = inet_addr_type(entry->ip);
 307         if (neigh->type != RTN_UNICAST) return -EINVAL;
 308
 309         rcu_read_lock();
 310         in_dev = rcu_dereference(__in_dev_get(dev));
 311         if (!in_dev) {
 312                 rcu_read_unlock();
 313                 return -EINVAL;
 314         }
 315
 316         parms = in_dev->arp_parms;
 317         __neigh_parms_put(neigh->parms);
 318         neigh->parms = neigh_parms_clone(parms);
 319         rcu_read_unlock();
 320
 321         neigh->ops = &clip_neigh_ops;
 322         neigh->output = neigh->nud_state & NUD_VALID ?
 323             neigh->ops->connected_output : neigh->ops->output;
 324         entry->neigh = neigh;
 325         entry->vccs = NULL;
 326         entry->expires = jiffies-1;
 327         return 0;
 328 }
 329
 330 static u32 clip_hash(const void *pkey, const struct net_device *dev)
 331 {
 332         return jhash_2words(*(u32 *)pkey, dev->ifindex, clip_tbl.hash_rnd);
 333 }
 334
 335 static struct neigh_table clip_tbl = {
 336         .family         = AF_INET,
 337         .entry_size     = sizeof(struct neighbour)+sizeof(struct atmarp_entry),
 338         .key_len        = 4,
 339         .hash           = clip_hash,
 340         .constructor    = clip_constructor,
 341         .id             = "clip_arp_cache",
 342
 343         /* parameters are copied from ARP ... */
 344         .parms = {
 345                 .tbl                    = &clip_tbl,
 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
 366 /* @@@ copy bh locking from arp.c -- need to bh-enable atm code before */
 367
 368 /*
 369  * We play with the resolve flag: 0 and 1 have the usual meaning, but -1 means
 370  * to allocate the neighbour entry but not to ask atmarpd for resolution. Also,
 371  * don't increment the usage count. This is used to create entries in
 372  * clip_setentry.
 373  */
 374
 375
 376 static int clip_encap(struct atm_vcc *vcc,int mode)
 377 {
 378         CLIP_VCC(vcc)->encap = mode;
 379         return 0;
 380 }
 381
 382
 383 static int clip_start_xmit(struct sk_buff *skb,struct net_device *dev)
 384 {
 385         struct clip_priv *clip_priv = PRIV(dev);
 386         struct atmarp_entry *entry;
 387         struct atm_vcc *vcc;
 388         int old;
 389         unsigned long flags;
 390
 391         DPRINTK("clip_start_xmit (skb %p)\n",skb);
 392         if (!skb->dst) {
 393                 printk(KERN_ERR "clip_start_xmit: skb->dst == NULL\n");
 394                 dev_kfree_skb(skb);
 395                 clip_priv->stats.tx_dropped++;
 396                 return 0;
 397         }
 398         if (!skb->dst->neighbour) {
 399 #if 0
 400                 skb->dst->neighbour = clip_find_neighbour(skb->dst,1);
 401                 if (!skb->dst->neighbour) {
 402                         dev_kfree_skb(skb); /* lost that one */
 403                         clip_priv->stats.tx_dropped++;
 404                         return 0;
 405                 }
 406 #endif
 407                 printk(KERN_ERR "clip_start_xmit: NO NEIGHBOUR !\n");
 408                 dev_kfree_skb(skb);
 409                 clip_priv->stats.tx_dropped++;
 410                 return 0;
 411         }
 412         entry = NEIGH2ENTRY(skb->dst->neighbour);
 413         if (!entry->vccs) {
 414                 if (time_after(jiffies, entry->expires)) {
 415                         /* should be resolved */
 416                         entry->expires = jiffies+ATMARP_RETRY_DELAY*HZ;
 417                         to_atmarpd(act_need,PRIV(dev)->number,entry->ip);
 418                 }
 419                 if (entry->neigh->arp_queue.qlen < ATMARP_MAX_UNRES_PACKETS)
 420                         skb_queue_tail(&entry->neigh->arp_queue,skb);
 421                 else {
 422                         dev_kfree_skb(skb);
 423                         clip_priv->stats.tx_dropped++;
 424                 }
 425                 return 0;
 426         }
 427         DPRINTK("neigh %p, vccs %p\n",entry,entry->vccs);
 428         ATM_SKB(skb)->vcc = vcc = entry->vccs->vcc;
 429         DPRINTK("using neighbour %p, vcc %p\n",skb->dst->neighbour,vcc);
 430         if (entry->vccs->encap) {
 431                 void *here;
 432
 433                 here = skb_push(skb,RFC1483LLC_LEN);
 434                 memcpy(here,llc_oui,sizeof(llc_oui));
 435                 ((u16 *) here)[3] = skb->protocol;
 436         }
 437         atomic_add(skb->truesize, &vcc->sk->sk_wmem_alloc);
 438         ATM_SKB(skb)->atm_options = vcc->atm_options;
 439         entry->vccs->last_use = jiffies;
 440         DPRINTK("atm_skb(%p)->vcc(%p)->dev(%p)\n",skb,vcc,vcc->dev);
 441         old = xchg(&entry->vccs->xoff,1); /* assume XOFF ... */
 442         if (old) {
 443                 printk(KERN_WARNING "clip_start_xmit: XOFF->XOFF transition\n");
 444                 return 0;
 445         }
 446         clip_priv->stats.tx_packets++;
 447         clip_priv->stats.tx_bytes += skb->len;
 448         (void) vcc->send(vcc,skb);
 449         if (atm_may_send(vcc,0)) {
 450                 entry->vccs->xoff = 0;
 451                 return 0;
 452         }
 453         spin_lock_irqsave(&clip_priv->xoff_lock,flags);
 454         netif_stop_queue(dev); /* XOFF -> throttle immediately */
 455         barrier();
 456         if (!entry->vccs->xoff)
 457                 netif_start_queue(dev);
 458                 /* Oh, we just raced with clip_pop. netif_start_queue should be
 459                    good enough, because nothing should really be asleep because
 460                    of the brief netif_stop_queue. If this isn't true or if it
 461                    changes, use netif_wake_queue instead. */
 462         spin_unlock_irqrestore(&clip_priv->xoff_lock,flags);
 463         return 0;
 464 }
 465
 466
 467 static struct net_device_stats *clip_get_stats(struct net_device *dev)
 468 {
 469         return &PRIV(dev)->stats;
 470 }
 471
 472
 473 static int clip_mkip(struct atm_vcc *vcc,int timeout)
 474 {
 475         struct clip_vcc *clip_vcc;
 476         struct sk_buff_head copy;
 477         struct sk_buff *skb;
 478
 479         if (!vcc->push) return -EBADFD;
 480         clip_vcc = kmalloc(sizeof(struct clip_vcc),GFP_KERNEL);
 481         if (!clip_vcc) return -ENOMEM;
 482         DPRINTK("mkip clip_vcc %p vcc %p\n",clip_vcc,vcc);
 483         clip_vcc->vcc = vcc;
 484         vcc->user_back = clip_vcc;
 485         set_bit(ATM_VF_IS_CLIP, &vcc->flags);
 486         clip_vcc->entry = NULL;
 487         clip_vcc->xoff = 0;
 488         clip_vcc->encap = 1;
 489         clip_vcc->last_use = jiffies;
 490         clip_vcc->idle_timeout = timeout*HZ;
 491         clip_vcc->old_push = vcc->push;
 492         clip_vcc->old_pop = vcc->pop;
 493         vcc->push = clip_push;
 494         vcc->pop = clip_pop;
 495         skb_queue_head_init(&copy);
 496         skb_migrate(&vcc->sk->sk_receive_queue, &copy);
 497         /* re-process everything received between connection setup and MKIP */
 498         while ((skb = skb_dequeue(&copy)) != NULL)
 499                 if (!clip_devs) {
 500                         atm_return(vcc,skb->truesize);
 501                         kfree_skb(skb);
 502                 }
 503                 else {
 504                         unsigned int len = skb->len;
 505
 506                         clip_push(vcc,skb);
 507                         PRIV(skb->dev)->stats.rx_packets--;
 508                         PRIV(skb->dev)->stats.rx_bytes -= len;
 509                 }
 510         return 0;
 511 }
 512
 513
 514 static int clip_setentry(struct atm_vcc *vcc,u32 ip)
 515 {
 516         struct neighbour *neigh;
 517         struct atmarp_entry *entry;
 518         int error;
 519         struct clip_vcc *clip_vcc;
 520         struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, .tos = 1 } } };
 521         struct rtable *rt;
 522
 523         if (vcc->push != clip_push) {
 524                 printk(KERN_WARNING "clip_setentry: non-CLIP VCC\n");
 525                 return -EBADF;
 526         }
 527         clip_vcc = CLIP_VCC(vcc);
 528         if (!ip) {
 529                 if (!clip_vcc->entry) {
 530                         printk(KERN_ERR "hiding hidden ATMARP entry\n");
 531                         return 0;
 532                 }
 533                 DPRINTK("setentry: remove\n");
 534                 unlink_clip_vcc(clip_vcc);
 535                 return 0;
 536         }
 537         error = ip_route_output_key(&rt,&fl);
 538         if (error) return error;
 539         neigh = __neigh_lookup(&clip_tbl,&ip,rt->u.dst.dev,1);
 540         ip_rt_put(rt);
 541         if (!neigh)
 542                 return -ENOMEM;
 543         entry = NEIGH2ENTRY(neigh);
 544         if (entry != clip_vcc->entry) {
 545                 if (!clip_vcc->entry) DPRINTK("setentry: add\n");
 546                 else {
 547                         DPRINTK("setentry: update\n");
 548                         unlink_clip_vcc(clip_vcc);
 549                 }
 550                 link_vcc(clip_vcc,entry);
 551         }
 552         error = neigh_update(neigh, llc_oui, NUD_PERMANENT,
 553                              NEIGH_UPDATE_F_OVERRIDE|NEIGH_UPDATE_F_ADMIN);
 554         neigh_release(neigh);
 555         return error;
 556 }
 557
 558
 559 static void clip_setup(struct net_device *dev)
 560 {
 561         dev->hard_start_xmit = clip_start_xmit;
 562         /* sg_xmit ... */
 563         dev->get_stats = clip_get_stats;
 564         dev->type = ARPHRD_ATM;
 565         dev->hard_header_len = RFC1483LLC_LEN;
 566         dev->mtu = RFC1626_MTU;
 567         dev->tx_queue_len = 100; /* "normal" queue (packets) */
 568             /* When using a "real" qdisc, the qdisc determines the queue */
 569             /* length. tx_queue_len is only used for the default case, */
 570             /* without any more elaborate queuing. 100 is a reasonable */
 571             /* compromise between decent burst-tolerance and protection */
 572             /* against memory hogs. */
 573 }
 574
 575
 576 static int clip_create(int number)
 577 {
 578         struct net_device *dev;
 579         struct clip_priv *clip_priv;
 580         int error;
 581
 582         if (number != -1) {
 583                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
 584                         if (PRIV(dev)->number == number) return -EEXIST;
 585         }
 586         else {
 587                 number = 0;
 588                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
 589                         if (PRIV(dev)->number >= number)
 590                                 number = PRIV(dev)->number+1;
 591         }
 592         dev = alloc_netdev(sizeof(struct clip_priv), "", clip_setup);
 593         if (!dev)
 594                 return -ENOMEM;
 595         clip_priv = PRIV(dev);
 596         sprintf(dev->name,"atm%d",number);
 597         spin_lock_init(&clip_priv->xoff_lock);
 598         clip_priv->number = number;
 599         error = register_netdev(dev);
 600         if (error) {
 601                 free_netdev(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)->hard_start_xmit != clip_start_xmit)
 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->sk_receive_queue))
 690                 printk(KERN_ERR "atmarpd_close: closing with requests "
 691                     "pending\n");
 692         skb_queue_purge(&vcc->sk->sk_receive_queue);
 693         DPRINTK("(done)\n");
 694         module_put(THIS_MODULE);
 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         if (atmarpd) return -EADDRINUSE;
 714         if (start_timer) {
 715                 start_timer = 0;
 716                 init_timer(&idle_timer);
 717                 idle_timer.expires = jiffies+CLIP_CHECK_INTERVAL*HZ;
 718                 idle_timer.function = idle_timer_check;
 719                 add_timer(&idle_timer);
 720         }
 721         atmarpd = vcc;
 722         set_bit(ATM_VF_META,&vcc->flags);
 723         set_bit(ATM_VF_READY,&vcc->flags);
 724             /* allow replies and avoid getting closed if signaling dies */
 725         vcc->dev = &atmarpd_dev;
 726         vcc_insert_socket(vcc->sk);
 727         vcc->push = NULL;
 728         vcc->pop = NULL; /* crash */
 729         vcc->push_oam = NULL; /* crash */
 730         if (register_netdevice_notifier(&clip_dev_notifier))
 731                 printk(KERN_ERR "register_netdevice_notifier failed\n");
 732         if (register_inetaddr_notifier(&clip_inet_notifier))
 733                 printk(KERN_ERR "register_inetaddr_notifier failed\n");
 734         return 0;
 735 }
 736
 737 static int clip_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 738 {
 739         struct atm_vcc *vcc = ATM_SD(sock);
 740         int err = 0;
 741
 742         switch (cmd) {
 743                 case SIOCMKCLIP:
 744                 case ATMARPD_CTRL:
 745                 case ATMARP_MKIP:
 746                 case ATMARP_SETENTRY:
 747                 case ATMARP_ENCAP:
 748                         if (!capable(CAP_NET_ADMIN))
 749                                 return -EPERM;
 750                         break;
 751                 default:
 752                         return -ENOIOCTLCMD;
 753         }
 754
 755         switch (cmd) {
 756                 case SIOCMKCLIP:
 757                         err = clip_create(arg);
 758                         break;
 759                 case ATMARPD_CTRL:
 760                         err = atm_init_atmarp(vcc);
 761                         if (!err) {
 762                                 sock->state = SS_CONNECTED;
 763                                 __module_get(THIS_MODULE);
 764                         }
 765                         break;
 766                 case ATMARP_MKIP:
 767                         err = clip_mkip(vcc ,arg);
 768                         break;
 769                 case ATMARP_SETENTRY:
 770                         err = clip_setentry(vcc, arg);
 771                         break;
 772                 case ATMARP_ENCAP:
 773                         err = clip_encap(vcc, arg);
 774                         break;
 775         }
 776         return err;
 777 }
 778
 779 static struct atm_ioctl clip_ioctl_ops = {
 780         .owner  = THIS_MODULE,
 781         .ioctl  = clip_ioctl,
 782 };
 783
 784 #ifdef CONFIG_PROC_FS
 785
 786 static void svc_addr(struct seq_file *seq, struct sockaddr_atmsvc *addr)
 787 {
 788         static int code[] = { 1,2,10,6,1,0 };
 789         static int e164[] = { 1,8,4,6,1,0 };
 790
 791         if (*addr->sas_addr.pub) {
 792                 seq_printf(seq, "%s", addr->sas_addr.pub);
 793                 if (*addr->sas_addr.prv)
 794                         seq_putc(seq, '+');
 795         } else if (!*addr->sas_addr.prv) {
 796                 seq_printf(seq, "%s", "(none)");
 797                 return;
 798         }
 799         if (*addr->sas_addr.prv) {
 800                 unsigned char *prv = addr->sas_addr.prv;
 801                 int *fields;
 802                 int i, j;
 803
 804                 fields = *prv == ATM_AFI_E164 ? e164 : code;
 805                 for (i = 0; fields[i]; i++) {
 806                         for (j = fields[i]; j; j--)
 807                                 seq_printf(seq, "%02X", *prv++);
 808                         if (fields[i+1])
 809                                 seq_putc(seq, '.');
 810                 }
 811         }
 812 }
 813
 814 /* This means the neighbour entry has no attached VCC objects. */
 815 #define SEQ_NO_VCC_TOKEN        ((void *) 2)
 816
 817 static void atmarp_info(struct seq_file *seq, struct net_device *dev,
 818                         struct atmarp_entry *entry, struct clip_vcc *clip_vcc)
 819 {
 820         unsigned long exp;
 821         char buf[17];
 822         int svc, llc, off;
 823
 824         svc = ((clip_vcc == SEQ_NO_VCC_TOKEN) ||
 825                (clip_vcc->vcc->sk->sk_family == AF_ATMSVC));
 826
 827         llc = ((clip_vcc == SEQ_NO_VCC_TOKEN) ||
 828                clip_vcc->encap);
 829
 830         if (clip_vcc == SEQ_NO_VCC_TOKEN)
 831                 exp = entry->neigh->used;
 832         else
 833                 exp = clip_vcc->last_use;
 834
 835         exp = (jiffies - exp) / HZ;
 836
 837         seq_printf(seq, "%-6s%-4s%-4s%5ld ",
 838                    dev->name,
 839                    svc ? "SVC" : "PVC",
 840                    llc ? "LLC" : "NULL",
 841                    exp);
 842
 843         off = scnprintf(buf, sizeof(buf) - 1, "%d.%d.%d.%d",
 844                         NIPQUAD(entry->ip));
 845         while (off < 16)
 846                 buf[off++] = ' ';
 847         buf[off] = '\0';
 848         seq_printf(seq, "%s", buf);
 849
 850         if (clip_vcc == SEQ_NO_VCC_TOKEN) {
 851                 if (time_before(jiffies, entry->expires))
 852                         seq_printf(seq, "(resolving)\n");
 853                 else
 854                         seq_printf(seq, "(expired, ref %d)\n",
 855                                    atomic_read(&entry->neigh->refcnt));
 856         } else if (!svc) {
 857                 seq_printf(seq, "%d.%d.%d\n",
 858                            clip_vcc->vcc->dev->number,
 859                            clip_vcc->vcc->vpi,
 860                            clip_vcc->vcc->vci);
 861         } else {
 862                 svc_addr(seq, &clip_vcc->vcc->remote);
 863                 seq_putc(seq, '\n');
 864         }
 865 }
 866
 867 struct clip_seq_state {
 868         /* This member must be first. */
 869         struct neigh_seq_state ns;
 870
 871         /* Local to clip specific iteration. */
 872         struct clip_vcc *vcc;
 873 };
 874
 875 static struct clip_vcc *clip_seq_next_vcc(struct atmarp_entry *e,
 876                                           struct clip_vcc *curr)
 877 {
 878         if (!curr) {
 879                 curr = e->vccs;
 880                 if (!curr)
 881                         return SEQ_NO_VCC_TOKEN;
 882                 return curr;
 883         }
 884         if (curr == SEQ_NO_VCC_TOKEN)
 885                 return NULL;
 886
 887         curr = curr->next;
 888
 889         return curr;
 890 }
 891
 892 static void *clip_seq_vcc_walk(struct clip_seq_state *state,
 893                                struct atmarp_entry *e, loff_t *pos)
 894 {
 895         struct clip_vcc *vcc = state->vcc;
 896
 897         vcc = clip_seq_next_vcc(e, vcc);
 898         if (vcc && pos != NULL) {
 899                 while (*pos) {
 900                         vcc = clip_seq_next_vcc(e, vcc);
 901                         if (!vcc)
 902                                 break;
 903                         --(*pos);
 904                 }
 905         }
 906         state->vcc = vcc;
 907
 908         return vcc;
 909 }
 910
 911 static void *clip_seq_sub_iter(struct neigh_seq_state *_state,
 912                                struct neighbour *n, loff_t *pos)
 913 {
 914         struct clip_seq_state *state = (struct clip_seq_state *) _state;
 915
 916         return clip_seq_vcc_walk(state, NEIGH2ENTRY(n), pos);
 917 }
 918
 919 static void *clip_seq_start(struct seq_file *seq, loff_t *pos)
 920 {
 921         return neigh_seq_start(seq, pos, &clip_tbl, NEIGH_SEQ_NEIGH_ONLY);
 922 }
 923
 924 static int clip_seq_show(struct seq_file *seq, void *v)
 925 {
 926         static char atm_arp_banner[] =
 927                 "IPitf TypeEncp Idle IP address      ATM address\n";
 928
 929         if (v == SEQ_START_TOKEN) {
 930                 seq_puts(seq, atm_arp_banner);
 931         } else {
 932                 struct clip_seq_state *state = seq->private;
 933                 struct neighbour *n = v;
 934                 struct clip_vcc *vcc = state->vcc;
 935
 936                 atmarp_info(seq, n->dev, NEIGH2ENTRY(n), vcc);
 937         }
 938         return 0;
 939 }
 940
 941 static struct seq_operations arp_seq_ops = {
 942         .start  = clip_seq_start,
 943         .next   = neigh_seq_next,
 944         .stop   = neigh_seq_stop,
 945         .show   = clip_seq_show,
 946 };
 947
 948 static int arp_seq_open(struct inode *inode, struct file *file)
 949 {
 950         struct clip_seq_state *state;
 951         struct seq_file *seq;
 952         int rc = -EAGAIN;
 953
 954         state = kmalloc(sizeof(*state), GFP_KERNEL);
 955         if (!state) {
 956                 rc = -ENOMEM;
 957                 goto out_kfree;
 958         }
 959         memset(state, 0, sizeof(*state));
 960         state->ns.neigh_sub_iter = clip_seq_sub_iter;
 961
 962         rc = seq_open(file, &arp_seq_ops);
 963         if (rc)
 964                 goto out_kfree;
 965
 966         seq = file->private_data;
 967         seq->private = state;
 968 out:
 969         return rc;
 970
 971 out_kfree:
 972         kfree(state);
 973         goto out;
 974 }
 975
 976 static struct file_operations arp_seq_fops = {
 977         .open           = arp_seq_open,
 978         .read           = seq_read,
 979         .llseek         = seq_lseek,
 980         .release        = seq_release_private,
 981         .owner          = THIS_MODULE
 982 };
 983 #endif
 984
 985 static int __init atm_clip_init(void)
 986 {
 987         neigh_table_init(&clip_tbl);
 988
 989         clip_tbl_hook = &clip_tbl;
 990         register_atm_ioctl(&clip_ioctl_ops);
 991
 992 #ifdef CONFIG_PROC_FS
 993 {
 994         struct proc_dir_entry *p;
 995
 996         p = create_proc_entry("arp", S_IRUGO, atm_proc_root);
 997         if (p)
 998                 p->proc_fops = &arp_seq_fops;
 999 }
1000 #endif
1001
1002         return 0;
1003 }
1004
1005 static void __exit atm_clip_exit(void)
1006 {
1007         struct net_device *dev, *next;
1008
1009         remove_proc_entry("arp", atm_proc_root);
1010
1011         deregister_atm_ioctl(&clip_ioctl_ops);
1012
1013         /* First, stop the idle timer, so it stops banging
1014          * on the table.
1015          */
1016         if (start_timer == 0)
1017                 del_timer(&idle_timer);
1018
1019         /* Next, purge the table, so that the device
1020          * unregister loop below does not hang due to
1021          * device references remaining in the table.
1022          */
1023         neigh_ifdown(&clip_tbl, NULL);
1024
1025         dev = clip_devs;
1026         while (dev) {
1027                 next = PRIV(dev)->next;
1028                 unregister_netdev(dev);
1029                 free_netdev(dev);
1030                 dev = next;
1031         }
1032
1033         /* Now it is safe to fully shutdown whole table. */
1034         neigh_table_clear(&clip_tbl);
1035
1036         clip_tbl_hook = NULL;
1037 }
1038
1039 module_init(atm_clip_init);
1040 module_exit(atm_clip_exit);
1041
1042 MODULE_LICENSE("GPL");