git.oblomov.eu Git - linux-2.6/blob - 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 sock *sk;
  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
  75         sk = sk_atm(atmarpd);
  76         skb_queue_tail(&sk->sk_receive_queue, skb);
  77         sk->sk_data_ready(sk, skb->len);
  78         return 0;
  79 }
  80
  81
  82 static void link_vcc(struct clip_vcc *clip_vcc,struct atmarp_entry *entry)
  83 {
  84         DPRINTK("link_vcc %p to entry %p (neigh %p)\n",clip_vcc,entry,
  85             entry->neigh);
  86         clip_vcc->entry = entry;
  87         clip_vcc->xoff = 0; /* @@@ may overrun buffer by one packet */
  88         clip_vcc->next = entry->vccs;
  89         entry->vccs = clip_vcc;
  90         entry->neigh->used = jiffies;
  91 }
  92
  93
  94 static void unlink_clip_vcc(struct clip_vcc *clip_vcc)
  95 {
  96         struct atmarp_entry *entry = clip_vcc->entry;
  97         struct clip_vcc **walk;
  98
  99         if (!entry) {
 100                 printk(KERN_CRIT "!clip_vcc->entry (clip_vcc %p)\n",clip_vcc);
 101                 return;
 102         }
 103         spin_lock_bh(&entry->neigh->dev->xmit_lock);    /* block clip_start_xmit() */
 104         entry->neigh->used = jiffies;
 105         for (walk = &entry->vccs; *walk; walk = &(*walk)->next)
 106                 if (*walk == clip_vcc) {
 107                         int error;
 108
 109                         *walk = clip_vcc->next; /* atomic */
 110                         clip_vcc->entry = NULL;
 111                         if (clip_vcc->xoff)
 112                                 netif_wake_queue(entry->neigh->dev);
 113                         if (entry->vccs)
 114                                 goto out;
 115                         entry->expires = jiffies-1;
 116                                 /* force resolution or expiration */
 117                         error = neigh_update(entry->neigh, NULL, NUD_NONE,
 118                                              NEIGH_UPDATE_F_ADMIN);
 119                         if (error)
 120                                 printk(KERN_CRIT "unlink_clip_vcc: "
 121                                     "neigh_update failed with %d\n",error);
 122                         goto out;
 123                 }
 124         printk(KERN_CRIT "ATMARP: unlink_clip_vcc failed (entry %p, vcc "
 125           "0x%p)\n",entry,clip_vcc);
 126 out:
 127         spin_unlock_bh(&entry->neigh->dev->xmit_lock);
 128 }
 129
 130 /* The neighbour entry n->lock is held. */
 131 static int neigh_check_cb(struct neighbour *n)
 132 {
 133         struct atmarp_entry *entry = NEIGH2ENTRY(n);
 134         struct clip_vcc *cv;
 135
 136         for (cv = entry->vccs; cv; cv = cv->next) {
 137                 unsigned long exp = cv->last_use + cv->idle_timeout;
 138
 139                 if (cv->idle_timeout && time_after(jiffies, exp)) {
 140                         DPRINTK("releasing vcc %p->%p of entry %p\n",
 141                                 cv, cv->vcc, entry);
 142                         vcc_release_async(cv->vcc, -ETIMEDOUT);
 143                 }
 144         }
 145
 146         if (entry->vccs || time_before(jiffies, entry->expires))
 147                 return 0;
 148
 149         if (atomic_read(&n->refcnt) > 1) {
 150                 struct sk_buff *skb;
 151
 152                 DPRINTK("destruction postponed with ref %d\n",
 153                         atomic_read(&n->refcnt));
 154
 155                 while ((skb = skb_dequeue(&n->arp_queue)) != NULL)
 156                         dev_kfree_skb(skb);
 157
 158                 return 0;
 159         }
 160
 161         DPRINTK("expired neigh %p\n",n);
 162         return 1;
 163 }
 164
 165 static void idle_timer_check(unsigned long dummy)
 166 {
 167         write_lock(&clip_tbl.lock);
 168         __neigh_for_each_release(&clip_tbl, neigh_check_cb);
 169         mod_timer(&idle_timer, jiffies+CLIP_CHECK_INTERVAL*HZ);
 170         write_unlock(&clip_tbl.lock);
 171 }
 172
 173 static int clip_arp_rcv(struct sk_buff *skb)
 174 {
 175         struct atm_vcc *vcc;
 176
 177         DPRINTK("clip_arp_rcv\n");
 178         vcc = ATM_SKB(skb)->vcc;
 179         if (!vcc || !atm_charge(vcc,skb->truesize)) {
 180                 dev_kfree_skb_any(skb);
 181                 return 0;
 182         }
 183         DPRINTK("pushing to %p\n",vcc);
 184         DPRINTK("using %p\n",CLIP_VCC(vcc)->old_push);
 185         CLIP_VCC(vcc)->old_push(vcc,skb);
 186         return 0;
 187 }
 188
 189 static const unsigned char llc_oui[] = {
 190         0xaa,   /* DSAP: non-ISO */
 191         0xaa,   /* SSAP: non-ISO */
 192         0x03,   /* Ctrl: Unnumbered Information Command PDU */
 193         0x00,   /* OUI: EtherType */
 194         0x00,
 195         0x00 };
 196
 197 static void clip_push(struct atm_vcc *vcc,struct sk_buff *skb)
 198 {
 199         struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
 200
 201         DPRINTK("clip push\n");
 202         if (!skb) {
 203                 DPRINTK("removing VCC %p\n",clip_vcc);
 204                 if (clip_vcc->entry) unlink_clip_vcc(clip_vcc);
 205                 clip_vcc->old_push(vcc,NULL); /* pass on the bad news */
 206                 kfree(clip_vcc);
 207                 return;
 208         }
 209         atm_return(vcc,skb->truesize);
 210         skb->dev = clip_vcc->entry ? clip_vcc->entry->neigh->dev : clip_devs;
 211                 /* clip_vcc->entry == NULL if we don't have an IP address yet */
 212         if (!skb->dev) {
 213                 dev_kfree_skb_any(skb);
 214                 return;
 215         }
 216         ATM_SKB(skb)->vcc = vcc;
 217         skb->mac.raw = skb->data;
 218         if (!clip_vcc->encap || skb->len < RFC1483LLC_LEN || memcmp(skb->data,
 219             llc_oui,sizeof(llc_oui))) skb->protocol = htons(ETH_P_IP);
 220         else {
 221                 skb->protocol = ((u16 *) skb->data)[3];
 222                 skb_pull(skb,RFC1483LLC_LEN);
 223                 if (skb->protocol == htons(ETH_P_ARP)) {
 224                         PRIV(skb->dev)->stats.rx_packets++;
 225                         PRIV(skb->dev)->stats.rx_bytes += skb->len;
 226                         clip_arp_rcv(skb);
 227                         return;
 228                 }
 229         }
 230         clip_vcc->last_use = jiffies;
 231         PRIV(skb->dev)->stats.rx_packets++;
 232         PRIV(skb->dev)->stats.rx_bytes += skb->len;
 233         memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
 234         netif_rx(skb);
 235 }
 236
 237
 238 /*
 239  * Note: these spinlocks _must_not_ block on non-SMP. The only goal is that
 240  * clip_pop is atomic with respect to the critical section in clip_start_xmit.
 241  */
 242
 243
 244 static void clip_pop(struct atm_vcc *vcc,struct sk_buff *skb)
 245 {
 246         struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
 247         struct net_device *dev = skb->dev;
 248         int old;
 249         unsigned long flags;
 250
 251         DPRINTK("clip_pop(vcc %p)\n",vcc);
 252         clip_vcc->old_pop(vcc,skb);
 253         /* skb->dev == NULL in outbound ARP packets */
 254         if (!dev) return;
 255         spin_lock_irqsave(&PRIV(dev)->xoff_lock,flags);
 256         if (atm_may_send(vcc,0)) {
 257                 old = xchg(&clip_vcc->xoff,0);
 258                 if (old) netif_wake_queue(dev);
 259         }
 260         spin_unlock_irqrestore(&PRIV(dev)->xoff_lock,flags);
 261 }
 262
 263
 264 static void clip_neigh_destroy(struct neighbour *neigh)
 265 {
 266         DPRINTK("clip_neigh_destroy (neigh %p)\n",neigh);
 267         if (NEIGH2ENTRY(neigh)->vccs)
 268                 printk(KERN_CRIT "clip_neigh_destroy: vccs != NULL !!!\n");
 269         NEIGH2ENTRY(neigh)->vccs = (void *) 0xdeadbeef;
 270 }
 271
 272
 273 static void clip_neigh_solicit(struct neighbour *neigh,struct sk_buff *skb)
 274 {
 275         DPRINTK("clip_neigh_solicit (neigh %p, skb %p)\n",neigh,skb);
 276         to_atmarpd(act_need,PRIV(neigh->dev)->number,NEIGH2ENTRY(neigh)->ip);
 277 }
 278
 279
 280 static void clip_neigh_error(struct neighbour *neigh,struct sk_buff *skb)
 281 {
 282 #ifndef CONFIG_ATM_CLIP_NO_ICMP
 283         icmp_send(skb,ICMP_DEST_UNREACH,ICMP_HOST_UNREACH,0);
 284 #endif
 285         kfree_skb(skb);
 286 }
 287
 288
 289 static struct neigh_ops clip_neigh_ops = {
 290         .family =               AF_INET,
 291         .destructor =           clip_neigh_destroy,
 292         .solicit =              clip_neigh_solicit,
 293         .error_report =         clip_neigh_error,
 294         .output =               dev_queue_xmit,
 295         .connected_output =     dev_queue_xmit,
 296         .hh_output =            dev_queue_xmit,
 297         .queue_xmit =           dev_queue_xmit,
 298 };
 299
 300
 301 static int clip_constructor(struct neighbour *neigh)
 302 {
 303         struct atmarp_entry *entry = NEIGH2ENTRY(neigh);
 304         struct net_device *dev = neigh->dev;
 305         struct in_device *in_dev;
 306         struct neigh_parms *parms;
 307
 308         DPRINTK("clip_constructor (neigh %p, entry %p)\n",neigh,entry);
 309         neigh->type = inet_addr_type(entry->ip);
 310         if (neigh->type != RTN_UNICAST) return -EINVAL;
 311
 312         rcu_read_lock();
 313         in_dev = rcu_dereference(__in_dev_get(dev));
 314         if (!in_dev) {
 315                 rcu_read_unlock();
 316                 return -EINVAL;
 317         }
 318
 319         parms = in_dev->arp_parms;
 320         __neigh_parms_put(neigh->parms);
 321         neigh->parms = neigh_parms_clone(parms);
 322         rcu_read_unlock();
 323
 324         neigh->ops = &clip_neigh_ops;
 325         neigh->output = neigh->nud_state & NUD_VALID ?
 326             neigh->ops->connected_output : neigh->ops->output;
 327         entry->neigh = neigh;
 328         entry->vccs = NULL;
 329         entry->expires = jiffies-1;
 330         return 0;
 331 }
 332
 333 static u32 clip_hash(const void *pkey, const struct net_device *dev)
 334 {
 335         return jhash_2words(*(u32 *)pkey, dev->ifindex, clip_tbl.hash_rnd);
 336 }
 337
 338 static struct neigh_table clip_tbl = {
 339         .family         = AF_INET,
 340         .entry_size     = sizeof(struct neighbour)+sizeof(struct atmarp_entry),
 341         .key_len        = 4,
 342         .hash           = clip_hash,
 343         .constructor    = clip_constructor,
 344         .id             = "clip_arp_cache",
 345
 346         /* parameters are copied from ARP ... */
 347         .parms = {
 348                 .tbl                    = &clip_tbl,
 349                 .base_reachable_time    = 30 * HZ,
 350                 .retrans_time           = 1 * HZ,
 351                 .gc_staletime           = 60 * HZ,
 352                 .reachable_time         = 30 * HZ,
 353                 .delay_probe_time       = 5 * HZ,
 354                 .queue_len              = 3,
 355                 .ucast_probes           = 3,
 356                 .mcast_probes           = 3,
 357                 .anycast_delay          = 1 * HZ,
 358                 .proxy_delay            = (8 * HZ) / 10,
 359                 .proxy_qlen             = 64,
 360                 .locktime               = 1 * HZ,
 361         },
 362         .gc_interval    = 30 * HZ,
 363         .gc_thresh1     = 128,
 364         .gc_thresh2     = 512,
 365         .gc_thresh3     = 1024,
 366 };
 367
 368
 369 /* @@@ copy bh locking from arp.c -- need to bh-enable atm code before */
 370
 371 /*
 372  * We play with the resolve flag: 0 and 1 have the usual meaning, but -1 means
 373  * to allocate the neighbour entry but not to ask atmarpd for resolution. Also,
 374  * don't increment the usage count. This is used to create entries in
 375  * clip_setentry.
 376  */
 377
 378
 379 static int clip_encap(struct atm_vcc *vcc,int mode)
 380 {
 381         CLIP_VCC(vcc)->encap = mode;
 382         return 0;
 383 }
 384
 385
 386 static int clip_start_xmit(struct sk_buff *skb,struct net_device *dev)
 387 {
 388         struct clip_priv *clip_priv = PRIV(dev);
 389         struct atmarp_entry *entry;
 390         struct atm_vcc *vcc;
 391         int old;
 392         unsigned long flags;
 393
 394         DPRINTK("clip_start_xmit (skb %p)\n",skb);
 395         if (!skb->dst) {
 396                 printk(KERN_ERR "clip_start_xmit: skb->dst == NULL\n");
 397                 dev_kfree_skb(skb);
 398                 clip_priv->stats.tx_dropped++;
 399                 return 0;
 400         }
 401         if (!skb->dst->neighbour) {
 402 #if 0
 403                 skb->dst->neighbour = clip_find_neighbour(skb->dst,1);
 404                 if (!skb->dst->neighbour) {
 405                         dev_kfree_skb(skb); /* lost that one */
 406                         clip_priv->stats.tx_dropped++;
 407                         return 0;
 408                 }
 409 #endif
 410                 printk(KERN_ERR "clip_start_xmit: NO NEIGHBOUR !\n");
 411                 dev_kfree_skb(skb);
 412                 clip_priv->stats.tx_dropped++;
 413                 return 0;
 414         }
 415         entry = NEIGH2ENTRY(skb->dst->neighbour);
 416         if (!entry->vccs) {
 417                 if (time_after(jiffies, entry->expires)) {
 418                         /* should be resolved */
 419                         entry->expires = jiffies+ATMARP_RETRY_DELAY*HZ;
 420                         to_atmarpd(act_need,PRIV(dev)->number,entry->ip);
 421                 }
 422                 if (entry->neigh->arp_queue.qlen < ATMARP_MAX_UNRES_PACKETS)
 423                         skb_queue_tail(&entry->neigh->arp_queue,skb);
 424                 else {
 425                         dev_kfree_skb(skb);
 426                         clip_priv->stats.tx_dropped++;
 427                 }
 428                 return 0;
 429         }
 430         DPRINTK("neigh %p, vccs %p\n",entry,entry->vccs);
 431         ATM_SKB(skb)->vcc = vcc = entry->vccs->vcc;
 432         DPRINTK("using neighbour %p, vcc %p\n",skb->dst->neighbour,vcc);
 433         if (entry->vccs->encap) {
 434                 void *here;
 435
 436                 here = skb_push(skb,RFC1483LLC_LEN);
 437                 memcpy(here,llc_oui,sizeof(llc_oui));
 438                 ((u16 *) here)[3] = skb->protocol;
 439         }
 440         atomic_add(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
 441         ATM_SKB(skb)->atm_options = vcc->atm_options;
 442         entry->vccs->last_use = jiffies;
 443         DPRINTK("atm_skb(%p)->vcc(%p)->dev(%p)\n",skb,vcc,vcc->dev);
 444         old = xchg(&entry->vccs->xoff,1); /* assume XOFF ... */
 445         if (old) {
 446                 printk(KERN_WARNING "clip_start_xmit: XOFF->XOFF transition\n");
 447                 return 0;
 448         }
 449         clip_priv->stats.tx_packets++;
 450         clip_priv->stats.tx_bytes += skb->len;
 451         (void) vcc->send(vcc,skb);
 452         if (atm_may_send(vcc,0)) {
 453                 entry->vccs->xoff = 0;
 454                 return 0;
 455         }
 456         spin_lock_irqsave(&clip_priv->xoff_lock,flags);
 457         netif_stop_queue(dev); /* XOFF -> throttle immediately */
 458         barrier();
 459         if (!entry->vccs->xoff)
 460                 netif_start_queue(dev);
 461                 /* Oh, we just raced with clip_pop. netif_start_queue should be
 462                    good enough, because nothing should really be asleep because
 463                    of the brief netif_stop_queue. If this isn't true or if it
 464                    changes, use netif_wake_queue instead. */
 465         spin_unlock_irqrestore(&clip_priv->xoff_lock,flags);
 466         return 0;
 467 }
 468
 469
 470 static struct net_device_stats *clip_get_stats(struct net_device *dev)
 471 {
 472         return &PRIV(dev)->stats;
 473 }
 474
 475
 476 static int clip_mkip(struct atm_vcc *vcc,int timeout)
 477 {
 478         struct clip_vcc *clip_vcc;
 479         struct sk_buff_head copy;
 480         struct sk_buff *skb;
 481
 482         if (!vcc->push) return -EBADFD;
 483         clip_vcc = kmalloc(sizeof(struct clip_vcc),GFP_KERNEL);
 484         if (!clip_vcc) return -ENOMEM;
 485         DPRINTK("mkip clip_vcc %p vcc %p\n",clip_vcc,vcc);
 486         clip_vcc->vcc = vcc;
 487         vcc->user_back = clip_vcc;
 488         set_bit(ATM_VF_IS_CLIP, &vcc->flags);
 489         clip_vcc->entry = NULL;
 490         clip_vcc->xoff = 0;
 491         clip_vcc->encap = 1;
 492         clip_vcc->last_use = jiffies;
 493         clip_vcc->idle_timeout = timeout*HZ;
 494         clip_vcc->old_push = vcc->push;
 495         clip_vcc->old_pop = vcc->pop;
 496         vcc->push = clip_push;
 497         vcc->pop = clip_pop;
 498         skb_queue_head_init(&copy);
 499         skb_migrate(&sk_atm(vcc)->sk_receive_queue, &copy);
 500         /* re-process everything received between connection setup and MKIP */
 501         while ((skb = skb_dequeue(&copy)) != NULL)
 502                 if (!clip_devs) {
 503                         atm_return(vcc,skb->truesize);
 504                         kfree_skb(skb);
 505                 }
 506                 else {
 507                         unsigned int len = skb->len;
 508
 509                         clip_push(vcc,skb);
 510                         PRIV(skb->dev)->stats.rx_packets--;
 511                         PRIV(skb->dev)->stats.rx_bytes -= len;
 512                 }
 513         return 0;
 514 }
 515
 516
 517 static int clip_setentry(struct atm_vcc *vcc,u32 ip)
 518 {
 519         struct neighbour *neigh;
 520         struct atmarp_entry *entry;
 521         int error;
 522         struct clip_vcc *clip_vcc;
 523         struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, .tos = 1 } } };
 524         struct rtable *rt;
 525
 526         if (vcc->push != clip_push) {
 527                 printk(KERN_WARNING "clip_setentry: non-CLIP VCC\n");
 528                 return -EBADF;
 529         }
 530         clip_vcc = CLIP_VCC(vcc);
 531         if (!ip) {
 532                 if (!clip_vcc->entry) {
 533                         printk(KERN_ERR "hiding hidden ATMARP entry\n");
 534                         return 0;
 535                 }
 536                 DPRINTK("setentry: remove\n");
 537                 unlink_clip_vcc(clip_vcc);
 538                 return 0;
 539         }
 540         error = ip_route_output_key(&rt,&fl);
 541         if (error) return error;
 542         neigh = __neigh_lookup(&clip_tbl,&ip,rt->u.dst.dev,1);
 543         ip_rt_put(rt);
 544         if (!neigh)
 545                 return -ENOMEM;
 546         entry = NEIGH2ENTRY(neigh);
 547         if (entry != clip_vcc->entry) {
 548                 if (!clip_vcc->entry) DPRINTK("setentry: add\n");
 549                 else {
 550                         DPRINTK("setentry: update\n");
 551                         unlink_clip_vcc(clip_vcc);
 552                 }
 553                 link_vcc(clip_vcc,entry);
 554         }
 555         error = neigh_update(neigh, llc_oui, NUD_PERMANENT,
 556                              NEIGH_UPDATE_F_OVERRIDE|NEIGH_UPDATE_F_ADMIN);
 557         neigh_release(neigh);
 558         return error;
 559 }
 560
 561
 562 static void clip_setup(struct net_device *dev)
 563 {
 564         dev->hard_start_xmit = clip_start_xmit;
 565         /* sg_xmit ... */
 566         dev->get_stats = clip_get_stats;
 567         dev->type = ARPHRD_ATM;
 568         dev->hard_header_len = RFC1483LLC_LEN;
 569         dev->mtu = RFC1626_MTU;
 570         dev->tx_queue_len = 100; /* "normal" queue (packets) */
 571             /* When using a "real" qdisc, the qdisc determines the queue */
 572             /* length. tx_queue_len is only used for the default case, */
 573             /* without any more elaborate queuing. 100 is a reasonable */
 574             /* compromise between decent burst-tolerance and protection */
 575             /* against memory hogs. */
 576 }
 577
 578
 579 static int clip_create(int number)
 580 {
 581         struct net_device *dev;
 582         struct clip_priv *clip_priv;
 583         int error;
 584
 585         if (number != -1) {
 586                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
 587                         if (PRIV(dev)->number == number) return -EEXIST;
 588         }
 589         else {
 590                 number = 0;
 591                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
 592                         if (PRIV(dev)->number >= number)
 593                                 number = PRIV(dev)->number+1;
 594         }
 595         dev = alloc_netdev(sizeof(struct clip_priv), "", clip_setup);
 596         if (!dev)
 597                 return -ENOMEM;
 598         clip_priv = PRIV(dev);
 599         sprintf(dev->name,"atm%d",number);
 600         spin_lock_init(&clip_priv->xoff_lock);
 601         clip_priv->number = number;
 602         error = register_netdev(dev);
 603         if (error) {
 604                 free_netdev(dev);
 605                 return error;
 606         }
 607         clip_priv->next = clip_devs;
 608         clip_devs = dev;
 609         DPRINTK("registered (net:%s)\n",dev->name);
 610         return number;
 611 }
 612
 613
 614 static int clip_device_event(struct notifier_block *this,unsigned long event,
 615     void *dev)
 616 {
 617         /* ignore non-CLIP devices */
 618         if (((struct net_device *) dev)->type != ARPHRD_ATM ||
 619             ((struct net_device *) dev)->hard_start_xmit != clip_start_xmit)
 620                 return NOTIFY_DONE;
 621         switch (event) {
 622                 case NETDEV_UP:
 623                         DPRINTK("clip_device_event NETDEV_UP\n");
 624                         (void) to_atmarpd(act_up,PRIV(dev)->number,0);
 625                         break;
 626                 case NETDEV_GOING_DOWN:
 627                         DPRINTK("clip_device_event NETDEV_DOWN\n");
 628                         (void) to_atmarpd(act_down,PRIV(dev)->number,0);
 629                         break;
 630                 case NETDEV_CHANGE:
 631                 case NETDEV_CHANGEMTU:
 632                         DPRINTK("clip_device_event NETDEV_CHANGE*\n");
 633                         (void) to_atmarpd(act_change,PRIV(dev)->number,0);
 634                         break;
 635                 case NETDEV_REBOOT:
 636                 case NETDEV_REGISTER:
 637                 case NETDEV_DOWN:
 638                         DPRINTK("clip_device_event %ld\n",event);
 639                         /* ignore */
 640                         break;
 641                 default:
 642                         printk(KERN_WARNING "clip_device_event: unknown event "
 643                             "%ld\n",event);
 644                         break;
 645         }
 646         return NOTIFY_DONE;
 647 }
 648
 649
 650 static int clip_inet_event(struct notifier_block *this,unsigned long event,
 651     void *ifa)
 652 {
 653         struct in_device *in_dev;
 654
 655         in_dev = ((struct in_ifaddr *) ifa)->ifa_dev;
 656         if (!in_dev || !in_dev->dev) {
 657                 printk(KERN_WARNING "clip_inet_event: no device\n");
 658                 return NOTIFY_DONE;
 659         }
 660         /*
 661          * Transitions are of the down-change-up type, so it's sufficient to
 662          * handle the change on up.
 663          */
 664         if (event != NETDEV_UP) return NOTIFY_DONE;
 665         return clip_device_event(this,NETDEV_CHANGE,in_dev->dev);
 666 }
 667
 668
 669 static struct notifier_block clip_dev_notifier = {
 670         clip_device_event,
 671         NULL,
 672         0
 673 };
 674
 675
 676
 677 static struct notifier_block clip_inet_notifier = {
 678         clip_inet_event,
 679         NULL,
 680         0
 681 };
 682
 683
 684
 685 static void atmarpd_close(struct atm_vcc *vcc)
 686 {
 687         DPRINTK("atmarpd_close\n");
 688         atmarpd = NULL; /* assumed to be atomic */
 689         barrier();
 690         unregister_inetaddr_notifier(&clip_inet_notifier);
 691         unregister_netdevice_notifier(&clip_dev_notifier);
 692         if (skb_peek(&sk_atm(vcc)->sk_receive_queue))
 693                 printk(KERN_ERR "atmarpd_close: closing with requests "
 694                     "pending\n");
 695         skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
 696         DPRINTK("(done)\n");
 697         module_put(THIS_MODULE);
 698 }
 699
 700
 701 static struct atmdev_ops atmarpd_dev_ops = {
 702         .close = atmarpd_close
 703 };
 704
 705
 706 static struct atm_dev atmarpd_dev = {
 707         .ops =                  &atmarpd_dev_ops,
 708         .type =                 "arpd",
 709         .number =               999,
 710         .lock =                 SPIN_LOCK_UNLOCKED
 711 };
 712
 713
 714 static int atm_init_atmarp(struct atm_vcc *vcc)
 715 {
 716         if (atmarpd) return -EADDRINUSE;
 717         if (start_timer) {
 718                 start_timer = 0;
 719                 init_timer(&idle_timer);
 720                 idle_timer.expires = jiffies+CLIP_CHECK_INTERVAL*HZ;
 721                 idle_timer.function = idle_timer_check;
 722                 add_timer(&idle_timer);
 723         }
 724         atmarpd = vcc;
 725         set_bit(ATM_VF_META,&vcc->flags);
 726         set_bit(ATM_VF_READY,&vcc->flags);
 727             /* allow replies and avoid getting closed if signaling dies */
 728         vcc->dev = &atmarpd_dev;
 729         vcc_insert_socket(sk_atm(vcc));
 730         vcc->push = NULL;
 731         vcc->pop = NULL; /* crash */
 732         vcc->push_oam = NULL; /* crash */
 733         if (register_netdevice_notifier(&clip_dev_notifier))
 734                 printk(KERN_ERR "register_netdevice_notifier failed\n");
 735         if (register_inetaddr_notifier(&clip_inet_notifier))
 736                 printk(KERN_ERR "register_inetaddr_notifier failed\n");
 737         return 0;
 738 }
 739
 740 static int clip_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 741 {
 742         struct atm_vcc *vcc = ATM_SD(sock);
 743         int err = 0;
 744
 745         switch (cmd) {
 746                 case SIOCMKCLIP:
 747                 case ATMARPD_CTRL:
 748                 case ATMARP_MKIP:
 749                 case ATMARP_SETENTRY:
 750                 case ATMARP_ENCAP:
 751                         if (!capable(CAP_NET_ADMIN))
 752                                 return -EPERM;
 753                         break;
 754                 default:
 755                         return -ENOIOCTLCMD;
 756         }
 757
 758         switch (cmd) {
 759                 case SIOCMKCLIP:
 760                         err = clip_create(arg);
 761                         break;
 762                 case ATMARPD_CTRL:
 763                         err = atm_init_atmarp(vcc);
 764                         if (!err) {
 765                                 sock->state = SS_CONNECTED;
 766                                 __module_get(THIS_MODULE);
 767                         }
 768                         break;
 769                 case ATMARP_MKIP:
 770                         err = clip_mkip(vcc ,arg);
 771                         break;
 772                 case ATMARP_SETENTRY:
 773                         err = clip_setentry(vcc, arg);
 774                         break;
 775                 case ATMARP_ENCAP:
 776                         err = clip_encap(vcc, arg);
 777                         break;
 778         }
 779         return err;
 780 }
 781
 782 static struct atm_ioctl clip_ioctl_ops = {
 783         .owner  = THIS_MODULE,
 784         .ioctl  = clip_ioctl,
 785 };
 786
 787 #ifdef CONFIG_PROC_FS
 788
 789 static void svc_addr(struct seq_file *seq, struct sockaddr_atmsvc *addr)
 790 {
 791         static int code[] = { 1,2,10,6,1,0 };
 792         static int e164[] = { 1,8,4,6,1,0 };
 793
 794         if (*addr->sas_addr.pub) {
 795                 seq_printf(seq, "%s", addr->sas_addr.pub);
 796                 if (*addr->sas_addr.prv)
 797                         seq_putc(seq, '+');
 798         } else if (!*addr->sas_addr.prv) {
 799                 seq_printf(seq, "%s", "(none)");
 800                 return;
 801         }
 802         if (*addr->sas_addr.prv) {
 803                 unsigned char *prv = addr->sas_addr.prv;
 804                 int *fields;
 805                 int i, j;
 806
 807                 fields = *prv == ATM_AFI_E164 ? e164 : code;
 808                 for (i = 0; fields[i]; i++) {
 809                         for (j = fields[i]; j; j--)
 810                                 seq_printf(seq, "%02X", *prv++);
 811                         if (fields[i+1])
 812                                 seq_putc(seq, '.');
 813                 }
 814         }
 815 }
 816
 817 /* This means the neighbour entry has no attached VCC objects. */
 818 #define SEQ_NO_VCC_TOKEN        ((void *) 2)
 819
 820 static void atmarp_info(struct seq_file *seq, struct net_device *dev,
 821                         struct atmarp_entry *entry, struct clip_vcc *clip_vcc)
 822 {
 823         unsigned long exp;
 824         char buf[17];
 825         int svc, llc, off;
 826
 827         svc = ((clip_vcc == SEQ_NO_VCC_TOKEN) ||
 828                (sk_atm(clip_vcc->vcc)->sk_family == AF_ATMSVC));
 829
 830         llc = ((clip_vcc == SEQ_NO_VCC_TOKEN) ||
 831                clip_vcc->encap);
 832
 833         if (clip_vcc == SEQ_NO_VCC_TOKEN)
 834                 exp = entry->neigh->used;
 835         else
 836                 exp = clip_vcc->last_use;
 837
 838         exp = (jiffies - exp) / HZ;
 839
 840         seq_printf(seq, "%-6s%-4s%-4s%5ld ",
 841                    dev->name,
 842                    svc ? "SVC" : "PVC",
 843                    llc ? "LLC" : "NULL",
 844                    exp);
 845
 846         off = scnprintf(buf, sizeof(buf) - 1, "%d.%d.%d.%d",
 847                         NIPQUAD(entry->ip));
 848         while (off < 16)
 849                 buf[off++] = ' ';
 850         buf[off] = '\0';
 851         seq_printf(seq, "%s", buf);
 852
 853         if (clip_vcc == SEQ_NO_VCC_TOKEN) {
 854                 if (time_before(jiffies, entry->expires))
 855                         seq_printf(seq, "(resolving)\n");
 856                 else
 857                         seq_printf(seq, "(expired, ref %d)\n",
 858                                    atomic_read(&entry->neigh->refcnt));
 859         } else if (!svc) {
 860                 seq_printf(seq, "%d.%d.%d\n",
 861                            clip_vcc->vcc->dev->number,
 862                            clip_vcc->vcc->vpi,
 863                            clip_vcc->vcc->vci);
 864         } else {
 865                 svc_addr(seq, &clip_vcc->vcc->remote);
 866                 seq_putc(seq, '\n');
 867         }
 868 }
 869
 870 struct clip_seq_state {
 871         /* This member must be first. */
 872         struct neigh_seq_state ns;
 873
 874         /* Local to clip specific iteration. */
 875         struct clip_vcc *vcc;
 876 };
 877
 878 static struct clip_vcc *clip_seq_next_vcc(struct atmarp_entry *e,
 879                                           struct clip_vcc *curr)
 880 {
 881         if (!curr) {
 882                 curr = e->vccs;
 883                 if (!curr)
 884                         return SEQ_NO_VCC_TOKEN;
 885                 return curr;
 886         }
 887         if (curr == SEQ_NO_VCC_TOKEN)
 888                 return NULL;
 889
 890         curr = curr->next;
 891
 892         return curr;
 893 }
 894
 895 static void *clip_seq_vcc_walk(struct clip_seq_state *state,
 896                                struct atmarp_entry *e, loff_t *pos)
 897 {
 898         struct clip_vcc *vcc = state->vcc;
 899
 900         vcc = clip_seq_next_vcc(e, vcc);
 901         if (vcc && pos != NULL) {
 902                 while (*pos) {
 903                         vcc = clip_seq_next_vcc(e, vcc);
 904                         if (!vcc)
 905                                 break;
 906                         --(*pos);
 907                 }
 908         }
 909         state->vcc = vcc;
 910
 911         return vcc;
 912 }
 913
 914 static void *clip_seq_sub_iter(struct neigh_seq_state *_state,
 915                                struct neighbour *n, loff_t *pos)
 916 {
 917         struct clip_seq_state *state = (struct clip_seq_state *) _state;
 918
 919         return clip_seq_vcc_walk(state, NEIGH2ENTRY(n), pos);
 920 }
 921
 922 static void *clip_seq_start(struct seq_file *seq, loff_t *pos)
 923 {
 924         return neigh_seq_start(seq, pos, &clip_tbl, NEIGH_SEQ_NEIGH_ONLY);
 925 }
 926
 927 static int clip_seq_show(struct seq_file *seq, void *v)
 928 {
 929         static char atm_arp_banner[] =
 930                 "IPitf TypeEncp Idle IP address      ATM address\n";
 931
 932         if (v == SEQ_START_TOKEN) {
 933                 seq_puts(seq, atm_arp_banner);
 934         } else {
 935                 struct clip_seq_state *state = seq->private;
 936                 struct neighbour *n = v;
 937                 struct clip_vcc *vcc = state->vcc;
 938
 939                 atmarp_info(seq, n->dev, NEIGH2ENTRY(n), vcc);
 940         }
 941         return 0;
 942 }
 943
 944 static struct seq_operations arp_seq_ops = {
 945         .start  = clip_seq_start,
 946         .next   = neigh_seq_next,
 947         .stop   = neigh_seq_stop,
 948         .show   = clip_seq_show,
 949 };
 950
 951 static int arp_seq_open(struct inode *inode, struct file *file)
 952 {
 953         struct clip_seq_state *state;
 954         struct seq_file *seq;
 955         int rc = -EAGAIN;
 956
 957         state = kmalloc(sizeof(*state), GFP_KERNEL);
 958         if (!state) {
 959                 rc = -ENOMEM;
 960                 goto out_kfree;
 961         }
 962         memset(state, 0, sizeof(*state));
 963         state->ns.neigh_sub_iter = clip_seq_sub_iter;
 964
 965         rc = seq_open(file, &arp_seq_ops);
 966         if (rc)
 967                 goto out_kfree;
 968
 969         seq = file->private_data;
 970         seq->private = state;
 971 out:
 972         return rc;
 973
 974 out_kfree:
 975         kfree(state);
 976         goto out;
 977 }
 978
 979 static struct file_operations arp_seq_fops = {
 980         .open           = arp_seq_open,
 981         .read           = seq_read,
 982         .llseek         = seq_lseek,
 983         .release        = seq_release_private,
 984         .owner          = THIS_MODULE
 985 };
 986 #endif
 987
 988 static int __init atm_clip_init(void)
 989 {
 990         neigh_table_init(&clip_tbl);
 991
 992         clip_tbl_hook = &clip_tbl;
 993         register_atm_ioctl(&clip_ioctl_ops);
 994
 995 #ifdef CONFIG_PROC_FS
 996 {
 997         struct proc_dir_entry *p;
 998
 999         p = create_proc_entry("arp", S_IRUGO, atm_proc_root);
1000         if (p)
1001                 p->proc_fops = &arp_seq_fops;
1002 }
1003 #endif
1004
1005         return 0;
1006 }
1007
1008 static void __exit atm_clip_exit(void)
1009 {
1010         struct net_device *dev, *next;
1011
1012         remove_proc_entry("arp", atm_proc_root);
1013
1014         deregister_atm_ioctl(&clip_ioctl_ops);
1015
1016         /* First, stop the idle timer, so it stops banging
1017          * on the table.
1018          */
1019         if (start_timer == 0)
1020                 del_timer(&idle_timer);
1021
1022         /* Next, purge the table, so that the device
1023          * unregister loop below does not hang due to
1024          * device references remaining in the table.
1025          */
1026         neigh_ifdown(&clip_tbl, NULL);
1027
1028         dev = clip_devs;
1029         while (dev) {
1030                 next = PRIV(dev)->next;
1031                 unregister_netdev(dev);
1032                 free_netdev(dev);
1033                 dev = next;
1034         }
1035
1036         /* Now it is safe to fully shutdown whole table. */
1037         neigh_table_clear(&clip_tbl);
1038
1039         clip_tbl_hook = NULL;
1040 }
1041
1042 module_init(atm_clip_init);
1043 module_exit(atm_clip_exit);
1044
1045 MODULE_LICENSE("GPL");