net/atm/clip.c

   1 /* net/atm/clip.c - RFC1577 Classical IP over ATM */
   2
   3 /* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */
   4
   5 #include <linux/string.h>
   6 #include <linux/errno.h>
   7 #include <linux/kernel.h> /* for UINT_MAX */
   8 #include <linux/module.h>
   9 #include <linux/init.h>
  10 #include <linux/netdevice.h>
  11 #include <linux/skbuff.h>
  12 #include <linux/wait.h>
  13 #include <linux/timer.h>
  14 #include <linux/if_arp.h> /* for some manifest constants */
  15 #include <linux/notifier.h>
  16 #include <linux/atm.h>
  17 #include <linux/atmdev.h>
  18 #include <linux/atmclip.h>
  19 #include <linux/atmarp.h>
  20 #include <linux/capability.h>
  21 #include <linux/ip.h> /* for net/route.h */
  22 #include <linux/in.h> /* for struct sockaddr_in */
  23 #include <linux/if.h> /* for IFF_UP */
  24 #include <linux/inetdevice.h>
  25 #include <linux/bitops.h>
  26 #include <linux/poison.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 <net/atmclip.h>
  42
  43
  44 #if 0
  45 #define DPRINTK(format,args...) printk(format,##args)
  46 #else
  47 #define DPRINTK(format,args...)
  48 #endif
  49
  50
  51 static struct net_device *clip_devs;
  52 static struct atm_vcc *atmarpd;
  53 static struct neigh_table clip_tbl;
  54 static struct timer_list idle_timer;
  55
  56 static int to_atmarpd(enum atmarp_ctrl_type type, int itf, __be32 ip)
  57 {
  58         struct sock *sk;
  59         struct atmarp_ctrl *ctrl;
  60         struct sk_buff *skb;
  61
  62         DPRINTK("to_atmarpd(%d)\n", type);
  63         if (!atmarpd)
  64                 return -EUNATCH;
  65         skb = alloc_skb(sizeof(struct atmarp_ctrl),GFP_ATOMIC);
  66         if (!skb)
  67                 return -ENOMEM;
  68         ctrl = (struct atmarp_ctrl *) skb_put(skb,sizeof(struct atmarp_ctrl));
  69         ctrl->type = type;
  70         ctrl->itf_num = itf;
  71         ctrl->ip = ip;
  72         atm_force_charge(atmarpd, skb->truesize);
  73
  74         sk = sk_atm(atmarpd);
  75         skb_queue_tail(&sk->sk_receive_queue, skb);
  76         sk->sk_data_ready(sk, skb->len);
  77         return 0;
  78 }
  79
  80 static void link_vcc(struct clip_vcc *clip_vcc, struct atmarp_entry *entry)
  81 {
  82         DPRINTK("link_vcc %p to entry %p (neigh %p)\n", clip_vcc, entry,
  83                 entry->neigh);
  84         clip_vcc->entry = entry;
  85         clip_vcc->xoff = 0;     /* @@@ may overrun buffer by one packet */
  86         clip_vcc->next = entry->vccs;
  87         entry->vccs = clip_vcc;
  88         entry->neigh->used = jiffies;
  89 }
  90
  91 static void unlink_clip_vcc(struct clip_vcc *clip_vcc)
  92 {
  93         struct atmarp_entry *entry = clip_vcc->entry;
  94         struct clip_vcc **walk;
  95
  96         if (!entry) {
  97                 printk(KERN_CRIT "!clip_vcc->entry (clip_vcc %p)\n", clip_vcc);
  98                 return;
  99         }
 100         netif_tx_lock_bh(entry->neigh->dev);    /* block clip_start_xmit() */
 101         entry->neigh->used = jiffies;
 102         for (walk = &entry->vccs; *walk; walk = &(*walk)->next)
 103                 if (*walk == clip_vcc) {
 104                         int error;
 105
 106                         *walk = clip_vcc->next; /* atomic */
 107                         clip_vcc->entry = NULL;
 108                         if (clip_vcc->xoff)
 109                                 netif_wake_queue(entry->neigh->dev);
 110                         if (entry->vccs)
 111                                 goto out;
 112                         entry->expires = jiffies - 1;
 113                         /* force resolution or expiration */
 114                         error = neigh_update(entry->neigh, NULL, NUD_NONE,
 115                                              NEIGH_UPDATE_F_ADMIN);
 116                         if (error)
 117                                 printk(KERN_CRIT "unlink_clip_vcc: "
 118                                        "neigh_update failed with %d\n", error);
 119                         goto out;
 120                 }
 121         printk(KERN_CRIT "ATMARP: unlink_clip_vcc failed (entry %p, vcc "
 122                "0x%p)\n", entry, clip_vcc);
 123       out:
 124         netif_tx_unlock_bh(entry->neigh->dev);
 125 }
 126
 127 /* The neighbour entry n->lock is held. */
 128 static int neigh_check_cb(struct neighbour *n)
 129 {
 130         struct atmarp_entry *entry = NEIGH2ENTRY(n);
 131         struct clip_vcc *cv;
 132
 133         for (cv = entry->vccs; cv; cv = cv->next) {
 134                 unsigned long exp = cv->last_use + cv->idle_timeout;
 135
 136                 if (cv->idle_timeout && time_after(jiffies, exp)) {
 137                         DPRINTK("releasing vcc %p->%p of entry %p\n",
 138                                 cv, cv->vcc, entry);
 139                         vcc_release_async(cv->vcc, -ETIMEDOUT);
 140                 }
 141         }
 142
 143         if (entry->vccs || time_before(jiffies, entry->expires))
 144                 return 0;
 145
 146         if (atomic_read(&n->refcnt) > 1) {
 147                 struct sk_buff *skb;
 148
 149                 DPRINTK("destruction postponed with ref %d\n",
 150                         atomic_read(&n->refcnt));
 151
 152                 while ((skb = skb_dequeue(&n->arp_queue)) != NULL)
 153                         dev_kfree_skb(skb);
 154
 155                 return 0;
 156         }
 157
 158         DPRINTK("expired neigh %p\n", n);
 159         return 1;
 160 }
 161
 162 static void idle_timer_check(unsigned long dummy)
 163 {
 164         write_lock(&clip_tbl.lock);
 165         __neigh_for_each_release(&clip_tbl, neigh_check_cb);
 166         mod_timer(&idle_timer, jiffies + CLIP_CHECK_INTERVAL * HZ);
 167         write_unlock(&clip_tbl.lock);
 168 }
 169
 170 static int clip_arp_rcv(struct sk_buff *skb)
 171 {
 172         struct atm_vcc *vcc;
 173
 174         DPRINTK("clip_arp_rcv\n");
 175         vcc = ATM_SKB(skb)->vcc;
 176         if (!vcc || !atm_charge(vcc, skb->truesize)) {
 177                 dev_kfree_skb_any(skb);
 178                 return 0;
 179         }
 180         DPRINTK("pushing to %p\n", vcc);
 181         DPRINTK("using %p\n", CLIP_VCC(vcc)->old_push);
 182         CLIP_VCC(vcc)->old_push(vcc, skb);
 183         return 0;
 184 }
 185
 186 static const unsigned char llc_oui[] = {
 187         0xaa,   /* DSAP: non-ISO */
 188         0xaa,   /* SSAP: non-ISO */
 189         0x03,   /* Ctrl: Unnumbered Information Command PDU */
 190         0x00,   /* OUI: EtherType */
 191         0x00,
 192         0x00
 193 };
 194
 195 static void clip_push(struct atm_vcc *vcc, struct sk_buff *skb)
 196 {
 197         struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
 198
 199         DPRINTK("clip push\n");
 200         if (!skb) {
 201                 DPRINTK("removing VCC %p\n", clip_vcc);
 202                 if (clip_vcc->entry)
 203                         unlink_clip_vcc(clip_vcc);
 204                 clip_vcc->old_push(vcc, NULL);  /* pass on the bad news */
 205                 kfree(clip_vcc);
 206                 return;
 207         }
 208         atm_return(vcc, skb->truesize);
 209         skb->dev = clip_vcc->entry ? clip_vcc->entry->neigh->dev : clip_devs;
 210         /* clip_vcc->entry == NULL if we don't have an IP address yet */
 211         if (!skb->dev) {
 212                 dev_kfree_skb_any(skb);
 213                 return;
 214         }
 215         ATM_SKB(skb)->vcc = vcc;
 216         skb->mac.raw = skb->data;
 217         if (!clip_vcc->encap
 218             || skb->len < RFC1483LLC_LEN
 219             || memcmp(skb->data, llc_oui, sizeof (llc_oui)))
 220                 skb->protocol = htons(ETH_P_IP);
 221         else {
 222                 skb->protocol = ((__be16 *) skb->data)[3];
 223                 skb_pull(skb, RFC1483LLC_LEN);
 224                 if (skb->protocol == htons(ETH_P_ARP)) {
 225                         PRIV(skb->dev)->stats.rx_packets++;
 226                         PRIV(skb->dev)->stats.rx_bytes += skb->len;
 227                         clip_arp_rcv(skb);
 228                         return;
 229                 }
 230         }
 231         clip_vcc->last_use = jiffies;
 232         PRIV(skb->dev)->stats.rx_packets++;
 233         PRIV(skb->dev)->stats.rx_bytes += skb->len;
 234         memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
 235         netif_rx(skb);
 236 }
 237
 238 /*
 239  * Note: these spinlocks _must_not_ block on non-SMP. The only goal is that
 240  * clip_pop is atomic with respect to the critical section in clip_start_xmit.
 241  */
 242
 243 static void clip_pop(struct atm_vcc *vcc, struct sk_buff *skb)
 244 {
 245         struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
 246         struct net_device *dev = skb->dev;
 247         int old;
 248         unsigned long flags;
 249
 250         DPRINTK("clip_pop(vcc %p)\n", vcc);
 251         clip_vcc->old_pop(vcc, skb);
 252         /* skb->dev == NULL in outbound ARP packets */
 253         if (!dev)
 254                 return;
 255         spin_lock_irqsave(&PRIV(dev)->xoff_lock, flags);
 256         if (atm_may_send(vcc, 0)) {
 257                 old = xchg(&clip_vcc->xoff, 0);
 258                 if (old)
 259                         netif_wake_queue(dev);
 260         }
 261         spin_unlock_irqrestore(&PRIV(dev)->xoff_lock, flags);
 262 }
 263
 264 static void clip_neigh_solicit(struct neighbour *neigh, struct sk_buff *skb)
 265 {
 266         DPRINTK("clip_neigh_solicit (neigh %p, skb %p)\n", neigh, skb);
 267         to_atmarpd(act_need, PRIV(neigh->dev)->number, NEIGH2ENTRY(neigh)->ip);
 268 }
 269
 270 static void clip_neigh_error(struct neighbour *neigh, struct sk_buff *skb)
 271 {
 272 #ifndef CONFIG_ATM_CLIP_NO_ICMP
 273         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
 274 #endif
 275         kfree_skb(skb);
 276 }
 277
 278 static struct neigh_ops clip_neigh_ops = {
 279         .family =               AF_INET,
 280         .solicit =              clip_neigh_solicit,
 281         .error_report =         clip_neigh_error,
 282         .output =               dev_queue_xmit,
 283         .connected_output =     dev_queue_xmit,
 284         .hh_output =            dev_queue_xmit,
 285         .queue_xmit =           dev_queue_xmit,
 286 };
 287
 288 static int clip_constructor(struct neighbour *neigh)
 289 {
 290         struct atmarp_entry *entry = NEIGH2ENTRY(neigh);
 291         struct net_device *dev = neigh->dev;
 292         struct in_device *in_dev;
 293         struct neigh_parms *parms;
 294
 295         DPRINTK("clip_constructor (neigh %p, entry %p)\n", neigh, entry);
 296         neigh->type = inet_addr_type(entry->ip);
 297         if (neigh->type != RTN_UNICAST)
 298                 return -EINVAL;
 299
 300         rcu_read_lock();
 301         in_dev = __in_dev_get_rcu(dev);
 302         if (!in_dev) {
 303                 rcu_read_unlock();
 304                 return -EINVAL;
 305         }
 306
 307         parms = in_dev->arp_parms;
 308         __neigh_parms_put(neigh->parms);
 309         neigh->parms = neigh_parms_clone(parms);
 310         rcu_read_unlock();
 311
 312         neigh->ops = &clip_neigh_ops;
 313         neigh->output = neigh->nud_state & NUD_VALID ?
 314             neigh->ops->connected_output : neigh->ops->output;
 315         entry->neigh = neigh;
 316         entry->vccs = NULL;
 317         entry->expires = jiffies - 1;
 318         return 0;
 319 }
 320
 321 static u32 clip_hash(const void *pkey, const struct net_device *dev)
 322 {
 323         return jhash_2words(*(u32 *) pkey, dev->ifindex, clip_tbl.hash_rnd);
 324 }
 325
 326 static struct neigh_table clip_tbl = {
 327         .family         = AF_INET,
 328         .entry_size     = sizeof(struct neighbour)+sizeof(struct atmarp_entry),
 329         .key_len        = 4,
 330         .hash           = clip_hash,
 331         .constructor    = clip_constructor,
 332         .id             = "clip_arp_cache",
 333
 334         /* parameters are copied from ARP ... */
 335         .parms = {
 336                 .tbl                    = &clip_tbl,
 337                 .base_reachable_time    = 30 * HZ,
 338                 .retrans_time           = 1 * HZ,
 339                 .gc_staletime           = 60 * HZ,
 340                 .reachable_time         = 30 * HZ,
 341                 .delay_probe_time       = 5 * HZ,
 342                 .queue_len              = 3,
 343                 .ucast_probes           = 3,
 344                 .mcast_probes           = 3,
 345                 .anycast_delay          = 1 * HZ,
 346                 .proxy_delay            = (8 * HZ) / 10,
 347                 .proxy_qlen             = 64,
 348                 .locktime               = 1 * HZ,
 349         },
 350         .gc_interval    = 30 * HZ,
 351         .gc_thresh1     = 128,
 352         .gc_thresh2     = 512,
 353         .gc_thresh3     = 1024,
 354 };
 355
 356 /* @@@ copy bh locking from arp.c -- need to bh-enable atm code before */
 357
 358 /*
 359  * We play with the resolve flag: 0 and 1 have the usual meaning, but -1 means
 360  * to allocate the neighbour entry but not to ask atmarpd for resolution. Also,
 361  * don't increment the usage count. This is used to create entries in
 362  * clip_setentry.
 363  */
 364
 365 static int clip_encap(struct atm_vcc *vcc, int mode)
 366 {
 367         CLIP_VCC(vcc)->encap = mode;
 368         return 0;
 369 }
 370
 371 static int clip_start_xmit(struct sk_buff *skb, struct net_device *dev)
 372 {
 373         struct clip_priv *clip_priv = PRIV(dev);
 374         struct atmarp_entry *entry;
 375         struct atm_vcc *vcc;
 376         int old;
 377         unsigned long flags;
 378
 379         DPRINTK("clip_start_xmit (skb %p)\n", skb);
 380         if (!skb->dst) {
 381                 printk(KERN_ERR "clip_start_xmit: skb->dst == NULL\n");
 382                 dev_kfree_skb(skb);
 383                 clip_priv->stats.tx_dropped++;
 384                 return 0;
 385         }
 386         if (!skb->dst->neighbour) {
 387 #if 0
 388                 skb->dst->neighbour = clip_find_neighbour(skb->dst, 1);
 389                 if (!skb->dst->neighbour) {
 390                         dev_kfree_skb(skb);     /* lost that one */
 391                         clip_priv->stats.tx_dropped++;
 392                         return 0;
 393                 }
 394 #endif
 395                 printk(KERN_ERR "clip_start_xmit: NO NEIGHBOUR !\n");
 396                 dev_kfree_skb(skb);
 397                 clip_priv->stats.tx_dropped++;
 398                 return 0;
 399         }
 400         entry = NEIGH2ENTRY(skb->dst->neighbour);
 401         if (!entry->vccs) {
 402                 if (time_after(jiffies, entry->expires)) {
 403                         /* should be resolved */
 404                         entry->expires = jiffies + ATMARP_RETRY_DELAY * HZ;
 405                         to_atmarpd(act_need, PRIV(dev)->number, entry->ip);
 406                 }
 407                 if (entry->neigh->arp_queue.qlen < ATMARP_MAX_UNRES_PACKETS)
 408                         skb_queue_tail(&entry->neigh->arp_queue, skb);
 409                 else {
 410                         dev_kfree_skb(skb);
 411                         clip_priv->stats.tx_dropped++;
 412                 }
 413                 return 0;
 414         }
 415         DPRINTK("neigh %p, vccs %p\n", entry, entry->vccs);
 416         ATM_SKB(skb)->vcc = vcc = entry->vccs->vcc;
 417         DPRINTK("using neighbour %p, vcc %p\n", skb->dst->neighbour, vcc);
 418         if (entry->vccs->encap) {
 419                 void *here;
 420
 421                 here = skb_push(skb, RFC1483LLC_LEN);
 422                 memcpy(here, llc_oui, sizeof(llc_oui));
 423                 ((__be16 *) here)[3] = skb->protocol;
 424         }
 425         atomic_add(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
 426         ATM_SKB(skb)->atm_options = vcc->atm_options;
 427         entry->vccs->last_use = jiffies;
 428         DPRINTK("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, vcc, vcc->dev);
 429         old = xchg(&entry->vccs->xoff, 1);      /* assume XOFF ... */
 430         if (old) {
 431                 printk(KERN_WARNING "clip_start_xmit: XOFF->XOFF transition\n");
 432                 return 0;
 433         }
 434         clip_priv->stats.tx_packets++;
 435         clip_priv->stats.tx_bytes += skb->len;
 436         vcc->send(vcc, skb);
 437         if (atm_may_send(vcc, 0)) {
 438                 entry->vccs->xoff = 0;
 439                 return 0;
 440         }
 441         spin_lock_irqsave(&clip_priv->xoff_lock, flags);
 442         netif_stop_queue(dev);  /* XOFF -> throttle immediately */
 443         barrier();
 444         if (!entry->vccs->xoff)
 445                 netif_start_queue(dev);
 446         /* Oh, we just raced with clip_pop. netif_start_queue should be
 447            good enough, because nothing should really be asleep because
 448            of the brief netif_stop_queue. If this isn't true or if it
 449            changes, use netif_wake_queue instead. */
 450         spin_unlock_irqrestore(&clip_priv->xoff_lock, flags);
 451         return 0;
 452 }
 453
 454 static struct net_device_stats *clip_get_stats(struct net_device *dev)
 455 {
 456         return &PRIV(dev)->stats;
 457 }
 458
 459 static int clip_mkip(struct atm_vcc *vcc, int timeout)
 460 {
 461         struct clip_vcc *clip_vcc;
 462         struct sk_buff *skb;
 463         struct sk_buff_head *rq;
 464         unsigned long flags;
 465
 466         if (!vcc->push)
 467                 return -EBADFD;
 468         clip_vcc = kmalloc(sizeof(struct clip_vcc), GFP_KERNEL);
 469         if (!clip_vcc)
 470                 return -ENOMEM;
 471         DPRINTK("mkip clip_vcc %p vcc %p\n", clip_vcc, vcc);
 472         clip_vcc->vcc = vcc;
 473         vcc->user_back = clip_vcc;
 474         set_bit(ATM_VF_IS_CLIP, &vcc->flags);
 475         clip_vcc->entry = NULL;
 476         clip_vcc->xoff = 0;
 477         clip_vcc->encap = 1;
 478         clip_vcc->last_use = jiffies;
 479         clip_vcc->idle_timeout = timeout * HZ;
 480         clip_vcc->old_push = vcc->push;
 481         clip_vcc->old_pop = vcc->pop;
 482         vcc->push = clip_push;
 483         vcc->pop = clip_pop;
 484
 485         rq = &sk_atm(vcc)->sk_receive_queue;
 486
 487         spin_lock_irqsave(&rq->lock, flags);
 488         if (skb_queue_empty(rq)) {
 489                 skb = NULL;
 490         } else {
 491                 /* NULL terminate the list.  */
 492                 rq->prev->next = NULL;
 493                 skb = rq->next;
 494         }
 495         rq->prev = rq->next = (struct sk_buff *)rq;
 496         rq->qlen = 0;
 497         spin_unlock_irqrestore(&rq->lock, flags);
 498
 499         /* re-process everything received between connection setup and MKIP */
 500         while (skb) {
 501                 struct sk_buff *next = skb->next;
 502
 503                 skb->next = skb->prev = NULL;
 504                 if (!clip_devs) {
 505                         atm_return(vcc, skb->truesize);
 506                         kfree_skb(skb);
 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
 517                 skb = next;
 518         }
 519         return 0;
 520 }
 521
 522 static int clip_setentry(struct atm_vcc *vcc, __be32 ip)
 523 {
 524         struct neighbour *neigh;
 525         struct atmarp_entry *entry;
 526         int error;
 527         struct clip_vcc *clip_vcc;
 528         struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, .tos = 1}} };
 529         struct rtable *rt;
 530
 531         if (vcc->push != clip_push) {
 532                 printk(KERN_WARNING "clip_setentry: non-CLIP VCC\n");
 533                 return -EBADF;
 534         }
 535         clip_vcc = CLIP_VCC(vcc);
 536         if (!ip) {
 537                 if (!clip_vcc->entry) {
 538                         printk(KERN_ERR "hiding hidden ATMARP entry\n");
 539                         return 0;
 540                 }
 541                 DPRINTK("setentry: remove\n");
 542                 unlink_clip_vcc(clip_vcc);
 543                 return 0;
 544         }
 545         error = ip_route_output_key(&rt, &fl);
 546         if (error)
 547                 return error;
 548         neigh = __neigh_lookup(&clip_tbl, &ip, rt->u.dst.dev, 1);
 549         ip_rt_put(rt);
 550         if (!neigh)
 551                 return -ENOMEM;
 552         entry = NEIGH2ENTRY(neigh);
 553         if (entry != clip_vcc->entry) {
 554                 if (!clip_vcc->entry)
 555                         DPRINTK("setentry: add\n");
 556                 else {
 557                         DPRINTK("setentry: update\n");
 558                         unlink_clip_vcc(clip_vcc);
 559                 }
 560                 link_vcc(clip_vcc, entry);
 561         }
 562         error = neigh_update(neigh, llc_oui, NUD_PERMANENT,
 563                              NEIGH_UPDATE_F_OVERRIDE | NEIGH_UPDATE_F_ADMIN);
 564         neigh_release(neigh);
 565         return error;
 566 }
 567
 568 static void clip_setup(struct net_device *dev)
 569 {
 570         dev->hard_start_xmit = clip_start_xmit;
 571         /* sg_xmit ... */
 572         dev->get_stats = clip_get_stats;
 573         dev->type = ARPHRD_ATM;
 574         dev->hard_header_len = RFC1483LLC_LEN;
 575         dev->mtu = RFC1626_MTU;
 576         dev->tx_queue_len = 100;        /* "normal" queue (packets) */
 577         /* When using a "real" qdisc, the qdisc determines the queue */
 578         /* length. tx_queue_len is only used for the default case, */
 579         /* without any more elaborate queuing. 100 is a reasonable */
 580         /* compromise between decent burst-tolerance and protection */
 581         /* against memory hogs. */
 582 }
 583
 584 static int clip_create(int number)
 585 {
 586         struct net_device *dev;
 587         struct clip_priv *clip_priv;
 588         int error;
 589
 590         if (number != -1) {
 591                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
 592                         if (PRIV(dev)->number == number)
 593                                 return -EEXIST;
 594         } else {
 595                 number = 0;
 596                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
 597                         if (PRIV(dev)->number >= number)
 598                                 number = PRIV(dev)->number + 1;
 599         }
 600         dev = alloc_netdev(sizeof(struct clip_priv), "", clip_setup);
 601         if (!dev)
 602                 return -ENOMEM;
 603         clip_priv = PRIV(dev);
 604         sprintf(dev->name, "atm%d", number);
 605         spin_lock_init(&clip_priv->xoff_lock);
 606         clip_priv->number = number;
 607         error = register_netdev(dev);
 608         if (error) {
 609                 free_netdev(dev);
 610                 return error;
 611         }
 612         clip_priv->next = clip_devs;
 613         clip_devs = dev;
 614         DPRINTK("registered (net:%s)\n", dev->name);
 615         return number;
 616 }
 617
 618 static int clip_device_event(struct notifier_block *this, unsigned long event,
 619                              void *arg)
 620 {
 621         struct net_device *dev = arg;
 622
 623         if (event == NETDEV_UNREGISTER) {
 624                 neigh_ifdown(&clip_tbl, dev);
 625                 return NOTIFY_DONE;
 626         }
 627
 628         /* ignore non-CLIP devices */
 629         if (dev->type != ARPHRD_ATM || dev->hard_start_xmit != clip_start_xmit)
 630                 return NOTIFY_DONE;
 631
 632         switch (event) {
 633         case NETDEV_UP:
 634                 DPRINTK("clip_device_event NETDEV_UP\n");
 635                 to_atmarpd(act_up, PRIV(dev)->number, 0);
 636                 break;
 637         case NETDEV_GOING_DOWN:
 638                 DPRINTK("clip_device_event NETDEV_DOWN\n");
 639                 to_atmarpd(act_down, PRIV(dev)->number, 0);
 640                 break;
 641         case NETDEV_CHANGE:
 642         case NETDEV_CHANGEMTU:
 643                 DPRINTK("clip_device_event NETDEV_CHANGE*\n");
 644                 to_atmarpd(act_change, PRIV(dev)->number, 0);
 645                 break;
 646         }
 647         return NOTIFY_DONE;
 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)
 665                 return NOTIFY_DONE;
 666         return clip_device_event(this, NETDEV_CHANGE, in_dev->dev);
 667 }
 668
 669
 670 static struct notifier_block clip_dev_notifier = {
 671         .notifier_call = clip_device_event,
 672 };
 673
 674
 675
 676 static struct notifier_block clip_inet_notifier = {
 677         .notifier_call = clip_inet_event,
 678 };
 679
 680
 681
 682 static void atmarpd_close(struct atm_vcc *vcc)
 683 {
 684         DPRINTK("atmarpd_close\n");
 685
 686         rtnl_lock();
 687         atmarpd = NULL;
 688         skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
 689         rtnl_unlock();
 690
 691         DPRINTK("(done)\n");
 692         module_put(THIS_MODULE);
 693 }
 694
 695
 696 static struct atmdev_ops atmarpd_dev_ops = {
 697         .close = atmarpd_close
 698 };
 699
 700
 701 static struct atm_dev atmarpd_dev = {
 702         .ops =                  &atmarpd_dev_ops,
 703         .type =                 "arpd",
 704         .number =               999,
 705         .lock =                 SPIN_LOCK_UNLOCKED
 706 };
 707
 708
 709 static int atm_init_atmarp(struct atm_vcc *vcc)
 710 {
 711         rtnl_lock();
 712         if (atmarpd) {
 713                 rtnl_unlock();
 714                 return -EADDRINUSE;
 715         }
 716
 717         mod_timer(&idle_timer, jiffies+CLIP_CHECK_INTERVAL*HZ);
 718
 719         atmarpd = vcc;
 720         set_bit(ATM_VF_META,&vcc->flags);
 721         set_bit(ATM_VF_READY,&vcc->flags);
 722             /* allow replies and avoid getting closed if signaling dies */
 723         vcc->dev = &atmarpd_dev;
 724         vcc_insert_socket(sk_atm(vcc));
 725         vcc->push = NULL;
 726         vcc->pop = NULL; /* crash */
 727         vcc->push_oam = NULL; /* crash */
 728         rtnl_unlock();
 729         return 0;
 730 }
 731
 732 static int clip_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 733 {
 734         struct atm_vcc *vcc = ATM_SD(sock);
 735         int err = 0;
 736
 737         switch (cmd) {
 738         case SIOCMKCLIP:
 739         case ATMARPD_CTRL:
 740         case ATMARP_MKIP:
 741         case ATMARP_SETENTRY:
 742         case ATMARP_ENCAP:
 743                 if (!capable(CAP_NET_ADMIN))
 744                         return -EPERM;
 745                 break;
 746         default:
 747                 return -ENOIOCTLCMD;
 748         }
 749
 750         switch (cmd) {
 751         case SIOCMKCLIP:
 752                 err = clip_create(arg);
 753                 break;
 754         case ATMARPD_CTRL:
 755                 err = atm_init_atmarp(vcc);
 756                 if (!err) {
 757                         sock->state = SS_CONNECTED;
 758                         __module_get(THIS_MODULE);
 759                 }
 760                 break;
 761         case ATMARP_MKIP:
 762                 err = clip_mkip(vcc, arg);
 763                 break;
 764         case ATMARP_SETENTRY:
 765                 err = clip_setentry(vcc, (__force __be32)arg);
 766                 break;
 767         case ATMARP_ENCAP:
 768                 err = clip_encap(vcc, arg);
 769                 break;
 770         }
 771         return err;
 772 }
 773
 774 static struct atm_ioctl clip_ioctl_ops = {
 775         .owner = THIS_MODULE,
 776         .ioctl = clip_ioctl,
 777 };
 778
 779 #ifdef CONFIG_PROC_FS
 780
 781 static void svc_addr(struct seq_file *seq, struct sockaddr_atmsvc *addr)
 782 {
 783         static int code[] = { 1, 2, 10, 6, 1, 0 };
 784         static int e164[] = { 1, 8, 4, 6, 1, 0 };
 785
 786         if (*addr->sas_addr.pub) {
 787                 seq_printf(seq, "%s", addr->sas_addr.pub);
 788                 if (*addr->sas_addr.prv)
 789                         seq_putc(seq, '+');
 790         } else if (!*addr->sas_addr.prv) {
 791                 seq_printf(seq, "%s", "(none)");
 792                 return;
 793         }
 794         if (*addr->sas_addr.prv) {
 795                 unsigned char *prv = addr->sas_addr.prv;
 796                 int *fields;
 797                 int i, j;
 798
 799                 fields = *prv == ATM_AFI_E164 ? e164 : code;
 800                 for (i = 0; fields[i]; i++) {
 801                         for (j = fields[i]; j; j--)
 802                                 seq_printf(seq, "%02X", *prv++);
 803                         if (fields[i + 1])
 804                                 seq_putc(seq, '.');
 805                 }
 806         }
 807 }
 808
 809 /* This means the neighbour entry has no attached VCC objects. */
 810 #define SEQ_NO_VCC_TOKEN        ((void *) 2)
 811
 812 static void atmarp_info(struct seq_file *seq, struct net_device *dev,
 813                         struct atmarp_entry *entry, struct clip_vcc *clip_vcc)
 814 {
 815         unsigned long exp;
 816         char buf[17];
 817         int svc, llc, off;
 818
 819         svc = ((clip_vcc == SEQ_NO_VCC_TOKEN) ||
 820                (sk_atm(clip_vcc->vcc)->sk_family == AF_ATMSVC));
 821
 822         llc = ((clip_vcc == SEQ_NO_VCC_TOKEN) || clip_vcc->encap);
 823
 824         if (clip_vcc == SEQ_NO_VCC_TOKEN)
 825                 exp = entry->neigh->used;
 826         else
 827                 exp = clip_vcc->last_use;
 828
 829         exp = (jiffies - exp) / HZ;
 830
 831         seq_printf(seq, "%-6s%-4s%-4s%5ld ",
 832                    dev->name, svc ? "SVC" : "PVC", llc ? "LLC" : "NULL", exp);
 833
 834         off = scnprintf(buf, sizeof(buf) - 1, "%d.%d.%d.%d",
 835                         NIPQUAD(entry->ip));
 836         while (off < 16)
 837                 buf[off++] = ' ';
 838         buf[off] = '\0';
 839         seq_printf(seq, "%s", buf);
 840
 841         if (clip_vcc == SEQ_NO_VCC_TOKEN) {
 842                 if (time_before(jiffies, entry->expires))
 843                         seq_printf(seq, "(resolving)\n");
 844                 else
 845                         seq_printf(seq, "(expired, ref %d)\n",
 846                                    atomic_read(&entry->neigh->refcnt));
 847         } else if (!svc) {
 848                 seq_printf(seq, "%d.%d.%d\n",
 849                            clip_vcc->vcc->dev->number,
 850                            clip_vcc->vcc->vpi, clip_vcc->vcc->vci);
 851         } else {
 852                 svc_addr(seq, &clip_vcc->vcc->remote);
 853                 seq_putc(seq, '\n');
 854         }
 855 }
 856
 857 struct clip_seq_state {
 858         /* This member must be first. */
 859         struct neigh_seq_state ns;
 860
 861         /* Local to clip specific iteration. */
 862         struct clip_vcc *vcc;
 863 };
 864
 865 static struct clip_vcc *clip_seq_next_vcc(struct atmarp_entry *e,
 866                                           struct clip_vcc *curr)
 867 {
 868         if (!curr) {
 869                 curr = e->vccs;
 870                 if (!curr)
 871                         return SEQ_NO_VCC_TOKEN;
 872                 return curr;
 873         }
 874         if (curr == SEQ_NO_VCC_TOKEN)
 875                 return NULL;
 876
 877         curr = curr->next;
 878
 879         return curr;
 880 }
 881
 882 static void *clip_seq_vcc_walk(struct clip_seq_state *state,
 883                                struct atmarp_entry *e, loff_t * pos)
 884 {
 885         struct clip_vcc *vcc = state->vcc;
 886
 887         vcc = clip_seq_next_vcc(e, vcc);
 888         if (vcc && pos != NULL) {
 889                 while (*pos) {
 890                         vcc = clip_seq_next_vcc(e, vcc);
 891                         if (!vcc)
 892                                 break;
 893                         --(*pos);
 894                 }
 895         }
 896         state->vcc = vcc;
 897
 898         return vcc;
 899 }
 900
 901 static void *clip_seq_sub_iter(struct neigh_seq_state *_state,
 902                                struct neighbour *n, loff_t * pos)
 903 {
 904         struct clip_seq_state *state = (struct clip_seq_state *)_state;
 905
 906         return clip_seq_vcc_walk(state, NEIGH2ENTRY(n), pos);
 907 }
 908
 909 static void *clip_seq_start(struct seq_file *seq, loff_t * pos)
 910 {
 911         return neigh_seq_start(seq, pos, &clip_tbl, NEIGH_SEQ_NEIGH_ONLY);
 912 }
 913
 914 static int clip_seq_show(struct seq_file *seq, void *v)
 915 {
 916         static char atm_arp_banner[] =
 917             "IPitf TypeEncp Idle IP address      ATM address\n";
 918
 919         if (v == SEQ_START_TOKEN) {
 920                 seq_puts(seq, atm_arp_banner);
 921         } else {
 922                 struct clip_seq_state *state = seq->private;
 923                 struct neighbour *n = v;
 924                 struct clip_vcc *vcc = state->vcc;
 925
 926                 atmarp_info(seq, n->dev, NEIGH2ENTRY(n), vcc);
 927         }
 928         return 0;
 929 }
 930
 931 static struct seq_operations arp_seq_ops = {
 932         .start  = clip_seq_start,
 933         .next   = neigh_seq_next,
 934         .stop   = neigh_seq_stop,
 935         .show   = clip_seq_show,
 936 };
 937
 938 static int arp_seq_open(struct inode *inode, struct file *file)
 939 {
 940         struct clip_seq_state *state;
 941         struct seq_file *seq;
 942         int rc = -EAGAIN;
 943
 944         state = kzalloc(sizeof(*state), GFP_KERNEL);
 945         if (!state) {
 946                 rc = -ENOMEM;
 947                 goto out_kfree;
 948         }
 949         state->ns.neigh_sub_iter = clip_seq_sub_iter;
 950
 951         rc = seq_open(file, &arp_seq_ops);
 952         if (rc)
 953                 goto out_kfree;
 954
 955         seq = file->private_data;
 956         seq->private = state;
 957 out:
 958         return rc;
 959
 960 out_kfree:
 961         kfree(state);
 962         goto out;
 963 }
 964
 965 static const struct file_operations arp_seq_fops = {
 966         .open           = arp_seq_open,
 967         .read           = seq_read,
 968         .llseek         = seq_lseek,
 969         .release        = seq_release_private,
 970         .owner          = THIS_MODULE
 971 };
 972 #endif
 973
 974 static int __init atm_clip_init(void)
 975 {
 976         neigh_table_init_no_netlink(&clip_tbl);
 977
 978         clip_tbl_hook = &clip_tbl;
 979         register_atm_ioctl(&clip_ioctl_ops);
 980         register_netdevice_notifier(&clip_dev_notifier);
 981         register_inetaddr_notifier(&clip_inet_notifier);
 982
 983         setup_timer(&idle_timer, idle_timer_check, 0);
 984
 985 #ifdef CONFIG_PROC_FS
 986         {
 987                 struct proc_dir_entry *p;
 988
 989                 p = create_proc_entry("arp", S_IRUGO, atm_proc_root);
 990                 if (p)
 991                         p->proc_fops = &arp_seq_fops;
 992         }
 993 #endif
 994
 995         return 0;
 996 }
 997
 998 static void __exit atm_clip_exit(void)
 999 {
1000         struct net_device *dev, *next;
1001
1002         remove_proc_entry("arp", atm_proc_root);
1003
1004         unregister_inetaddr_notifier(&clip_inet_notifier);
1005         unregister_netdevice_notifier(&clip_dev_notifier);
1006
1007         deregister_atm_ioctl(&clip_ioctl_ops);
1008
1009         /* First, stop the idle timer, so it stops banging
1010          * on the table.
1011          */
1012         del_timer_sync(&idle_timer);
1013
1014         /* Next, purge the table, so that the device
1015          * unregister loop below does not hang due to
1016          * device references remaining in the table.
1017          */
1018         neigh_ifdown(&clip_tbl, NULL);
1019
1020         dev = clip_devs;
1021         while (dev) {
1022                 next = PRIV(dev)->next;
1023                 unregister_netdev(dev);
1024                 free_netdev(dev);
1025                 dev = next;
1026         }
1027
1028         /* Now it is safe to fully shutdown whole table. */
1029         neigh_table_clear(&clip_tbl);
1030
1031         clip_tbl_hook = NULL;
1032 }
1033
1034 module_init(atm_clip_init);
1035 module_exit(atm_clip_exit);
1036 MODULE_AUTHOR("Werner Almesberger");
1037 MODULE_DESCRIPTION("Classical/IP over ATM interface");
1038 MODULE_LICENSE("GPL");