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 "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
  57 static int to_atmarpd(enum atmarp_ctrl_type type, int itf, unsigned long ip)
  58 {
  59         struct sock *sk;
  60         struct atmarp_ctrl *ctrl;
  61         struct sk_buff *skb;
  62
  63         DPRINTK("to_atmarpd(%d)\n", type);
  64         if (!atmarpd)
  65                 return -EUNATCH;
  66         skb = alloc_skb(sizeof(struct atmarp_ctrl),GFP_ATOMIC);
  67         if (!skb)
  68                 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 static void link_vcc(struct clip_vcc *clip_vcc, struct atmarp_entry *entry)
  82 {
  83         DPRINTK("link_vcc %p to entry %p (neigh %p)\n", clip_vcc, entry,
  84                 entry->neigh);
  85         clip_vcc->entry = entry;
  86         clip_vcc->xoff = 0;     /* @@@ may overrun buffer by one packet */
  87         clip_vcc->next = entry->vccs;
  88         entry->vccs = clip_vcc;
  89         entry->neigh->used = jiffies;
  90 }
  91
  92 static void unlink_clip_vcc(struct clip_vcc *clip_vcc)
  93 {
  94         struct atmarp_entry *entry = clip_vcc->entry;
  95         struct clip_vcc **walk;
  96
  97         if (!entry) {
  98                 printk(KERN_CRIT "!clip_vcc->entry (clip_vcc %p)\n", clip_vcc);
  99                 return;
 100         }
 101         netif_tx_lock_bh(entry->neigh->dev);    /* block clip_start_xmit() */
 102         entry->neigh->used = jiffies;
 103         for (walk = &entry->vccs; *walk; walk = &(*walk)->next)
 104                 if (*walk == clip_vcc) {
 105                         int error;
 106
 107                         *walk = clip_vcc->next; /* atomic */
 108                         clip_vcc->entry = NULL;
 109                         if (clip_vcc->xoff)
 110                                 netif_wake_queue(entry->neigh->dev);
 111                         if (entry->vccs)
 112                                 goto out;
 113                         entry->expires = jiffies - 1;
 114                         /* force resolution or expiration */
 115                         error = neigh_update(entry->neigh, NULL, NUD_NONE,
 116                                              NEIGH_UPDATE_F_ADMIN);
 117                         if (error)
 118                                 printk(KERN_CRIT "unlink_clip_vcc: "
 119                                        "neigh_update failed with %d\n", error);
 120                         goto out;
 121                 }
 122         printk(KERN_CRIT "ATMARP: unlink_clip_vcc failed (entry %p, vcc "
 123                "0x%p)\n", entry, clip_vcc);
 124       out:
 125         netif_tx_unlock_bh(entry->neigh->dev);
 126 }
 127
 128 /* The neighbour entry n->lock is held. */
 129 static int neigh_check_cb(struct neighbour *n)
 130 {
 131         struct atmarp_entry *entry = NEIGH2ENTRY(n);
 132         struct clip_vcc *cv;
 133
 134         for (cv = entry->vccs; cv; cv = cv->next) {
 135                 unsigned long exp = cv->last_use + cv->idle_timeout;
 136
 137                 if (cv->idle_timeout && time_after(jiffies, exp)) {
 138                         DPRINTK("releasing vcc %p->%p of entry %p\n",
 139                                 cv, cv->vcc, entry);
 140                         vcc_release_async(cv->vcc, -ETIMEDOUT);
 141                 }
 142         }
 143
 144         if (entry->vccs || time_before(jiffies, entry->expires))
 145                 return 0;
 146
 147         if (atomic_read(&n->refcnt) > 1) {
 148                 struct sk_buff *skb;
 149
 150                 DPRINTK("destruction postponed with ref %d\n",
 151                         atomic_read(&n->refcnt));
 152
 153                 while ((skb = skb_dequeue(&n->arp_queue)) != NULL)
 154                         dev_kfree_skb(skb);
 155
 156                 return 0;
 157         }
 158
 159         DPRINTK("expired neigh %p\n", n);
 160         return 1;
 161 }
 162
 163 static void idle_timer_check(unsigned long dummy)
 164 {
 165         write_lock(&clip_tbl.lock);
 166         __neigh_for_each_release(&clip_tbl, neigh_check_cb);
 167         mod_timer(&idle_timer, jiffies + CLIP_CHECK_INTERVAL * HZ);
 168         write_unlock(&clip_tbl.lock);
 169 }
 170
 171 static int clip_arp_rcv(struct sk_buff *skb)
 172 {
 173         struct atm_vcc *vcc;
 174
 175         DPRINTK("clip_arp_rcv\n");
 176         vcc = ATM_SKB(skb)->vcc;
 177         if (!vcc || !atm_charge(vcc, skb->truesize)) {
 178                 dev_kfree_skb_any(skb);
 179                 return 0;
 180         }
 181         DPRINTK("pushing to %p\n", vcc);
 182         DPRINTK("using %p\n", CLIP_VCC(vcc)->old_push);
 183         CLIP_VCC(vcc)->old_push(vcc, skb);
 184         return 0;
 185 }
 186
 187 static const unsigned char llc_oui[] = {
 188         0xaa,   /* DSAP: non-ISO */
 189         0xaa,   /* SSAP: non-ISO */
 190         0x03,   /* Ctrl: Unnumbered Information Command PDU */
 191         0x00,   /* OUI: EtherType */
 192         0x00,
 193         0x00
 194 };
 195
 196 static void clip_push(struct atm_vcc *vcc, struct sk_buff *skb)
 197 {
 198         struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
 199
 200         DPRINTK("clip push\n");
 201         if (!skb) {
 202                 DPRINTK("removing VCC %p\n", clip_vcc);
 203                 if (clip_vcc->entry)
 204                         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
 219             || skb->len < RFC1483LLC_LEN
 220             || memcmp(skb->data, llc_oui, sizeof (llc_oui)))
 221                 skb->protocol = htons(ETH_P_IP);
 222         else {
 223                 skb->protocol = ((u16 *) skb->data)[3];
 224                 skb_pull(skb, RFC1483LLC_LEN);
 225                 if (skb->protocol == htons(ETH_P_ARP)) {
 226                         PRIV(skb->dev)->stats.rx_packets++;
 227                         PRIV(skb->dev)->stats.rx_bytes += skb->len;
 228                         clip_arp_rcv(skb);
 229                         return;
 230                 }
 231         }
 232         clip_vcc->last_use = jiffies;
 233         PRIV(skb->dev)->stats.rx_packets++;
 234         PRIV(skb->dev)->stats.rx_bytes += skb->len;
 235         memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
 236         netif_rx(skb);
 237 }
 238
 239 /*
 240  * Note: these spinlocks _must_not_ block on non-SMP. The only goal is that
 241  * clip_pop is atomic with respect to the critical section in clip_start_xmit.
 242  */
 243
 244 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)
 255                 return;
 256         spin_lock_irqsave(&PRIV(dev)->xoff_lock, flags);
 257         if (atm_may_send(vcc, 0)) {
 258                 old = xchg(&clip_vcc->xoff, 0);
 259                 if (old)
 260                         netif_wake_queue(dev);
 261         }
 262         spin_unlock_irqrestore(&PRIV(dev)->xoff_lock, flags);
 263 }
 264
 265 static void clip_neigh_destroy(struct neighbour *neigh)
 266 {
 267         DPRINTK("clip_neigh_destroy (neigh %p)\n", neigh);
 268         if (NEIGH2ENTRY(neigh)->vccs)
 269                 printk(KERN_CRIT "clip_neigh_destroy: vccs != NULL !!!\n");
 270         NEIGH2ENTRY(neigh)->vccs = (void *) NEIGHBOR_DEAD;
 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 static void clip_neigh_error(struct neighbour *neigh, struct sk_buff *skb)
 280 {
 281 #ifndef CONFIG_ATM_CLIP_NO_ICMP
 282         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
 283 #endif
 284         kfree_skb(skb);
 285 }
 286
 287 static struct neigh_ops clip_neigh_ops = {
 288         .family =               AF_INET,
 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 static int clip_constructor(struct neighbour *neigh)
 298 {
 299         struct atmarp_entry *entry = NEIGH2ENTRY(neigh);
 300         struct net_device *dev = neigh->dev;
 301         struct in_device *in_dev;
 302         struct neigh_parms *parms;
 303
 304         DPRINTK("clip_constructor (neigh %p, entry %p)\n", neigh, entry);
 305         neigh->type = inet_addr_type(entry->ip);
 306         if (neigh->type != RTN_UNICAST)
 307                 return -EINVAL;
 308
 309         rcu_read_lock();
 310         in_dev = __in_dev_get_rcu(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                 .neigh_destructor       = clip_neigh_destroy,
 347                 .base_reachable_time    = 30 * HZ,
 348                 .retrans_time           = 1 * HZ,
 349                 .gc_staletime           = 60 * HZ,
 350                 .reachable_time         = 30 * HZ,
 351                 .delay_probe_time       = 5 * HZ,
 352                 .queue_len              = 3,
 353                 .ucast_probes           = 3,
 354                 .mcast_probes           = 3,
 355                 .anycast_delay          = 1 * HZ,
 356                 .proxy_delay            = (8 * HZ) / 10,
 357                 .proxy_qlen             = 64,
 358                 .locktime               = 1 * HZ,
 359         },
 360         .gc_interval    = 30 * HZ,
 361         .gc_thresh1     = 128,
 362         .gc_thresh2     = 512,
 363         .gc_thresh3     = 1024,
 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 static int clip_encap(struct atm_vcc *vcc, int mode)
 376 {
 377         CLIP_VCC(vcc)->encap = mode;
 378         return 0;
 379 }
 380
 381 static int clip_start_xmit(struct sk_buff *skb, struct net_device *dev)
 382 {
 383         struct clip_priv *clip_priv = PRIV(dev);
 384         struct atmarp_entry *entry;
 385         struct atm_vcc *vcc;
 386         int old;
 387         unsigned long flags;
 388
 389         DPRINTK("clip_start_xmit (skb %p)\n", skb);
 390         if (!skb->dst) {
 391                 printk(KERN_ERR "clip_start_xmit: skb->dst == NULL\n");
 392                 dev_kfree_skb(skb);
 393                 clip_priv->stats.tx_dropped++;
 394                 return 0;
 395         }
 396         if (!skb->dst->neighbour) {
 397 #if 0
 398                 skb->dst->neighbour = clip_find_neighbour(skb->dst, 1);
 399                 if (!skb->dst->neighbour) {
 400                         dev_kfree_skb(skb);     /* lost that one */
 401                         clip_priv->stats.tx_dropped++;
 402                         return 0;
 403                 }
 404 #endif
 405                 printk(KERN_ERR "clip_start_xmit: NO NEIGHBOUR !\n");
 406                 dev_kfree_skb(skb);
 407                 clip_priv->stats.tx_dropped++;
 408                 return 0;
 409         }
 410         entry = NEIGH2ENTRY(skb->dst->neighbour);
 411         if (!entry->vccs) {
 412                 if (time_after(jiffies, entry->expires)) {
 413                         /* should be resolved */
 414                         entry->expires = jiffies + ATMARP_RETRY_DELAY * HZ;
 415                         to_atmarpd(act_need, PRIV(dev)->number, entry->ip);
 416                 }
 417                 if (entry->neigh->arp_queue.qlen < ATMARP_MAX_UNRES_PACKETS)
 418                         skb_queue_tail(&entry->neigh->arp_queue, skb);
 419                 else {
 420                         dev_kfree_skb(skb);
 421                         clip_priv->stats.tx_dropped++;
 422                 }
 423                 return 0;
 424         }
 425         DPRINTK("neigh %p, vccs %p\n", entry, entry->vccs);
 426         ATM_SKB(skb)->vcc = vcc = entry->vccs->vcc;
 427         DPRINTK("using neighbour %p, vcc %p\n", skb->dst->neighbour, vcc);
 428         if (entry->vccs->encap) {
 429                 void *here;
 430
 431                 here = skb_push(skb, RFC1483LLC_LEN);
 432                 memcpy(here, llc_oui, sizeof(llc_oui));
 433                 ((u16 *) here)[3] = skb->protocol;
 434         }
 435         atomic_add(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
 436         ATM_SKB(skb)->atm_options = vcc->atm_options;
 437         entry->vccs->last_use = jiffies;
 438         DPRINTK("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, vcc, vcc->dev);
 439         old = xchg(&entry->vccs->xoff, 1);      /* assume XOFF ... */
 440         if (old) {
 441                 printk(KERN_WARNING "clip_start_xmit: XOFF->XOFF transition\n");
 442                 return 0;
 443         }
 444         clip_priv->stats.tx_packets++;
 445         clip_priv->stats.tx_bytes += skb->len;
 446         vcc->send(vcc, skb);
 447         if (atm_may_send(vcc, 0)) {
 448                 entry->vccs->xoff = 0;
 449                 return 0;
 450         }
 451         spin_lock_irqsave(&clip_priv->xoff_lock, flags);
 452         netif_stop_queue(dev);  /* XOFF -> throttle immediately */
 453         barrier();
 454         if (!entry->vccs->xoff)
 455                 netif_start_queue(dev);
 456         /* Oh, we just raced with clip_pop. netif_start_queue should be
 457            good enough, because nothing should really be asleep because
 458            of the brief netif_stop_queue. If this isn't true or if it
 459            changes, use netif_wake_queue instead. */
 460         spin_unlock_irqrestore(&clip_priv->xoff_lock, flags);
 461         return 0;
 462 }
 463
 464 static struct net_device_stats *clip_get_stats(struct net_device *dev)
 465 {
 466         return &PRIV(dev)->stats;
 467 }
 468
 469 static int clip_mkip(struct atm_vcc *vcc, int timeout)
 470 {
 471         struct clip_vcc *clip_vcc;
 472         struct sk_buff_head copy;
 473         struct sk_buff *skb;
 474
 475         if (!vcc->push)
 476                 return -EBADFD;
 477         clip_vcc = kmalloc(sizeof(struct clip_vcc), GFP_KERNEL);
 478         if (!clip_vcc)
 479                 return -ENOMEM;
 480         DPRINTK("mkip clip_vcc %p vcc %p\n", clip_vcc, vcc);
 481         clip_vcc->vcc = vcc;
 482         vcc->user_back = clip_vcc;
 483         set_bit(ATM_VF_IS_CLIP, &vcc->flags);
 484         clip_vcc->entry = NULL;
 485         clip_vcc->xoff = 0;
 486         clip_vcc->encap = 1;
 487         clip_vcc->last_use = jiffies;
 488         clip_vcc->idle_timeout = timeout * HZ;
 489         clip_vcc->old_push = vcc->push;
 490         clip_vcc->old_pop = vcc->pop;
 491         vcc->push = clip_push;
 492         vcc->pop = clip_pop;
 493         skb_queue_head_init(&copy);
 494         skb_migrate(&sk_atm(vcc)->sk_receive_queue, &copy);
 495         /* re-process everything received between connection setup and MKIP */
 496         while ((skb = skb_dequeue(&copy)) != NULL)
 497                 if (!clip_devs) {
 498                         atm_return(vcc, skb->truesize);
 499                         kfree_skb(skb);
 500                 } else {
 501                         unsigned int len = skb->len;
 502
 503                         skb_get(skb);
 504                         clip_push(vcc, skb);
 505                         PRIV(skb->dev)->stats.rx_packets--;
 506                         PRIV(skb->dev)->stats.rx_bytes -= len;
 507                         kfree_skb(skb);
 508                 }
 509         return 0;
 510 }
 511
 512 static int clip_setentry(struct atm_vcc *vcc, u32 ip)
 513 {
 514         struct neighbour *neigh;
 515         struct atmarp_entry *entry;
 516         int error;
 517         struct clip_vcc *clip_vcc;
 518         struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, .tos = 1}} };
 519         struct rtable *rt;
 520
 521         if (vcc->push != clip_push) {
 522                 printk(KERN_WARNING "clip_setentry: non-CLIP VCC\n");
 523                 return -EBADF;
 524         }
 525         clip_vcc = CLIP_VCC(vcc);
 526         if (!ip) {
 527                 if (!clip_vcc->entry) {
 528                         printk(KERN_ERR "hiding hidden ATMARP entry\n");
 529                         return 0;
 530                 }
 531                 DPRINTK("setentry: remove\n");
 532                 unlink_clip_vcc(clip_vcc);
 533                 return 0;
 534         }
 535         error = ip_route_output_key(&rt, &fl);
 536         if (error)
 537                 return error;
 538         neigh = __neigh_lookup(&clip_tbl, &ip, rt->u.dst.dev, 1);
 539         ip_rt_put(rt);
 540         if (!neigh)
 541                 return -ENOMEM;
 542         entry = NEIGH2ENTRY(neigh);
 543         if (entry != clip_vcc->entry) {
 544                 if (!clip_vcc->entry)
 545                         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 static void clip_setup(struct net_device *dev)
 559 {
 560         dev->hard_start_xmit = clip_start_xmit;
 561         /* sg_xmit ... */
 562         dev->get_stats = clip_get_stats;
 563         dev->type = ARPHRD_ATM;
 564         dev->hard_header_len = RFC1483LLC_LEN;
 565         dev->mtu = RFC1626_MTU;
 566         dev->tx_queue_len = 100;        /* "normal" queue (packets) */
 567         /* When using a "real" qdisc, the qdisc determines the queue */
 568         /* length. tx_queue_len is only used for the default case, */
 569         /* without any more elaborate queuing. 100 is a reasonable */
 570         /* compromise between decent burst-tolerance and protection */
 571         /* against memory hogs. */
 572 }
 573
 574 static int clip_create(int number)
 575 {
 576         struct net_device *dev;
 577         struct clip_priv *clip_priv;
 578         int error;
 579
 580         if (number != -1) {
 581                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
 582                         if (PRIV(dev)->number == number)
 583                                 return -EEXIST;
 584         } else {
 585                 number = 0;
 586                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
 587                         if (PRIV(dev)->number >= number)
 588                                 number = PRIV(dev)->number + 1;
 589         }
 590         dev = alloc_netdev(sizeof(struct clip_priv), "", clip_setup);
 591         if (!dev)
 592                 return -ENOMEM;
 593         clip_priv = PRIV(dev);
 594         sprintf(dev->name, "atm%d", number);
 595         spin_lock_init(&clip_priv->xoff_lock);
 596         clip_priv->number = number;
 597         error = register_netdev(dev);
 598         if (error) {
 599                 free_netdev(dev);
 600                 return error;
 601         }
 602         clip_priv->next = clip_devs;
 603         clip_devs = dev;
 604         DPRINTK("registered (net:%s)\n", dev->name);
 605         return number;
 606 }
 607
 608 static int clip_device_event(struct notifier_block *this, unsigned long event,
 609                              void *arg)
 610 {
 611         struct net_device *dev = arg;
 612
 613         if (event == NETDEV_UNREGISTER) {
 614                 neigh_ifdown(&clip_tbl, dev);
 615                 return NOTIFY_DONE;
 616         }
 617
 618         /* ignore non-CLIP devices */
 619         if (dev->type != ARPHRD_ATM || dev->hard_start_xmit != clip_start_xmit)
 620                 return NOTIFY_DONE;
 621
 622         switch (event) {
 623         case NETDEV_UP:
 624                 DPRINTK("clip_device_event NETDEV_UP\n");
 625                 to_atmarpd(act_up, PRIV(dev)->number, 0);
 626                 break;
 627         case NETDEV_GOING_DOWN:
 628                 DPRINTK("clip_device_event NETDEV_DOWN\n");
 629                 to_atmarpd(act_down, PRIV(dev)->number, 0);
 630                 break;
 631         case NETDEV_CHANGE:
 632         case NETDEV_CHANGEMTU:
 633                 DPRINTK("clip_device_event NETDEV_CHANGE*\n");
 634                 to_atmarpd(act_change, PRIV(dev)->number, 0);
 635                 break;
 636         }
 637         return NOTIFY_DONE;
 638 }
 639
 640 static int clip_inet_event(struct notifier_block *this, unsigned long event,
 641                            void *ifa)
 642 {
 643         struct in_device *in_dev;
 644
 645         in_dev = ((struct in_ifaddr *)ifa)->ifa_dev;
 646         if (!in_dev || !in_dev->dev) {
 647                 printk(KERN_WARNING "clip_inet_event: no device\n");
 648                 return NOTIFY_DONE;
 649         }
 650         /*
 651          * Transitions are of the down-change-up type, so it's sufficient to
 652          * handle the change on up.
 653          */
 654         if (event != NETDEV_UP)
 655                 return NOTIFY_DONE;
 656         return clip_device_event(this, NETDEV_CHANGE, in_dev->dev);
 657 }
 658
 659
 660 static struct notifier_block clip_dev_notifier = {
 661         .notifier_call = clip_device_event,
 662 };
 663
 664
 665
 666 static struct notifier_block clip_inet_notifier = {
 667         .notifier_call = clip_inet_event,
 668 };
 669
 670
 671
 672 static void atmarpd_close(struct atm_vcc *vcc)
 673 {
 674         DPRINTK("atmarpd_close\n");
 675
 676         rtnl_lock();
 677         atmarpd = NULL;
 678         skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
 679         rtnl_unlock();
 680
 681         DPRINTK("(done)\n");
 682         module_put(THIS_MODULE);
 683 }
 684
 685
 686 static struct atmdev_ops atmarpd_dev_ops = {
 687         .close = atmarpd_close
 688 };
 689
 690
 691 static struct atm_dev atmarpd_dev = {
 692         .ops =                  &atmarpd_dev_ops,
 693         .type =                 "arpd",
 694         .number =               999,
 695         .lock =                 SPIN_LOCK_UNLOCKED
 696 };
 697
 698
 699 static int atm_init_atmarp(struct atm_vcc *vcc)
 700 {
 701         rtnl_lock();
 702         if (atmarpd) {
 703                 rtnl_unlock();
 704                 return -EADDRINUSE;
 705         }
 706
 707         mod_timer(&idle_timer, jiffies+CLIP_CHECK_INTERVAL*HZ);
 708
 709         atmarpd = vcc;
 710         set_bit(ATM_VF_META,&vcc->flags);
 711         set_bit(ATM_VF_READY,&vcc->flags);
 712             /* allow replies and avoid getting closed if signaling dies */
 713         vcc->dev = &atmarpd_dev;
 714         vcc_insert_socket(sk_atm(vcc));
 715         vcc->push = NULL;
 716         vcc->pop = NULL; /* crash */
 717         vcc->push_oam = NULL; /* crash */
 718         rtnl_unlock();
 719         return 0;
 720 }
 721
 722 static int clip_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 723 {
 724         struct atm_vcc *vcc = ATM_SD(sock);
 725         int err = 0;
 726
 727         switch (cmd) {
 728         case SIOCMKCLIP:
 729         case ATMARPD_CTRL:
 730         case ATMARP_MKIP:
 731         case ATMARP_SETENTRY:
 732         case ATMARP_ENCAP:
 733                 if (!capable(CAP_NET_ADMIN))
 734                         return -EPERM;
 735                 break;
 736         default:
 737                 return -ENOIOCTLCMD;
 738         }
 739
 740         switch (cmd) {
 741         case SIOCMKCLIP:
 742                 err = clip_create(arg);
 743                 break;
 744         case ATMARPD_CTRL:
 745                 err = atm_init_atmarp(vcc);
 746                 if (!err) {
 747                         sock->state = SS_CONNECTED;
 748                         __module_get(THIS_MODULE);
 749                 }
 750                 break;
 751         case ATMARP_MKIP:
 752                 err = clip_mkip(vcc, arg);
 753                 break;
 754         case ATMARP_SETENTRY:
 755                 err = clip_setentry(vcc, arg);
 756                 break;
 757         case ATMARP_ENCAP:
 758                 err = clip_encap(vcc, arg);
 759                 break;
 760         }
 761         return err;
 762 }
 763
 764 static struct atm_ioctl clip_ioctl_ops = {
 765         .owner = THIS_MODULE,
 766         .ioctl = clip_ioctl,
 767 };
 768
 769 #ifdef CONFIG_PROC_FS
 770
 771 static void svc_addr(struct seq_file *seq, struct sockaddr_atmsvc *addr)
 772 {
 773         static int code[] = { 1, 2, 10, 6, 1, 0 };
 774         static int e164[] = { 1, 8, 4, 6, 1, 0 };
 775
 776         if (*addr->sas_addr.pub) {
 777                 seq_printf(seq, "%s", addr->sas_addr.pub);
 778                 if (*addr->sas_addr.prv)
 779                         seq_putc(seq, '+');
 780         } else if (!*addr->sas_addr.prv) {
 781                 seq_printf(seq, "%s", "(none)");
 782                 return;
 783         }
 784         if (*addr->sas_addr.prv) {
 785                 unsigned char *prv = addr->sas_addr.prv;
 786                 int *fields;
 787                 int i, j;
 788
 789                 fields = *prv == ATM_AFI_E164 ? e164 : code;
 790                 for (i = 0; fields[i]; i++) {
 791                         for (j = fields[i]; j; j--)
 792                                 seq_printf(seq, "%02X", *prv++);
 793                         if (fields[i + 1])
 794                                 seq_putc(seq, '.');
 795                 }
 796         }
 797 }
 798
 799 /* This means the neighbour entry has no attached VCC objects. */
 800 #define SEQ_NO_VCC_TOKEN        ((void *) 2)
 801
 802 static void atmarp_info(struct seq_file *seq, struct net_device *dev,
 803                         struct atmarp_entry *entry, struct clip_vcc *clip_vcc)
 804 {
 805         unsigned long exp;
 806         char buf[17];
 807         int svc, llc, off;
 808
 809         svc = ((clip_vcc == SEQ_NO_VCC_TOKEN) ||
 810                (sk_atm(clip_vcc->vcc)->sk_family == AF_ATMSVC));
 811
 812         llc = ((clip_vcc == SEQ_NO_VCC_TOKEN) || clip_vcc->encap);
 813
 814         if (clip_vcc == SEQ_NO_VCC_TOKEN)
 815                 exp = entry->neigh->used;
 816         else
 817                 exp = clip_vcc->last_use;
 818
 819         exp = (jiffies - exp) / HZ;
 820
 821         seq_printf(seq, "%-6s%-4s%-4s%5ld ",
 822                    dev->name, svc ? "SVC" : "PVC", llc ? "LLC" : "NULL", exp);
 823
 824         off = scnprintf(buf, sizeof(buf) - 1, "%d.%d.%d.%d",
 825                         NIPQUAD(entry->ip));
 826         while (off < 16)
 827                 buf[off++] = ' ';
 828         buf[off] = '\0';
 829         seq_printf(seq, "%s", buf);
 830
 831         if (clip_vcc == SEQ_NO_VCC_TOKEN) {
 832                 if (time_before(jiffies, entry->expires))
 833                         seq_printf(seq, "(resolving)\n");
 834                 else
 835                         seq_printf(seq, "(expired, ref %d)\n",
 836                                    atomic_read(&entry->neigh->refcnt));
 837         } else if (!svc) {
 838                 seq_printf(seq, "%d.%d.%d\n",
 839                            clip_vcc->vcc->dev->number,
 840                            clip_vcc->vcc->vpi, clip_vcc->vcc->vci);
 841         } else {
 842                 svc_addr(seq, &clip_vcc->vcc->remote);
 843                 seq_putc(seq, '\n');
 844         }
 845 }
 846
 847 struct clip_seq_state {
 848         /* This member must be first. */
 849         struct neigh_seq_state ns;
 850
 851         /* Local to clip specific iteration. */
 852         struct clip_vcc *vcc;
 853 };
 854
 855 static struct clip_vcc *clip_seq_next_vcc(struct atmarp_entry *e,
 856                                           struct clip_vcc *curr)
 857 {
 858         if (!curr) {
 859                 curr = e->vccs;
 860                 if (!curr)
 861                         return SEQ_NO_VCC_TOKEN;
 862                 return curr;
 863         }
 864         if (curr == SEQ_NO_VCC_TOKEN)
 865                 return NULL;
 866
 867         curr = curr->next;
 868
 869         return curr;
 870 }
 871
 872 static void *clip_seq_vcc_walk(struct clip_seq_state *state,
 873                                struct atmarp_entry *e, loff_t * pos)
 874 {
 875         struct clip_vcc *vcc = state->vcc;
 876
 877         vcc = clip_seq_next_vcc(e, vcc);
 878         if (vcc && pos != NULL) {
 879                 while (*pos) {
 880                         vcc = clip_seq_next_vcc(e, vcc);
 881                         if (!vcc)
 882                                 break;
 883                         --(*pos);
 884                 }
 885         }
 886         state->vcc = vcc;
 887
 888         return vcc;
 889 }
 890
 891 static void *clip_seq_sub_iter(struct neigh_seq_state *_state,
 892                                struct neighbour *n, loff_t * pos)
 893 {
 894         struct clip_seq_state *state = (struct clip_seq_state *)_state;
 895
 896         return clip_seq_vcc_walk(state, NEIGH2ENTRY(n), pos);
 897 }
 898
 899 static void *clip_seq_start(struct seq_file *seq, loff_t * pos)
 900 {
 901         return neigh_seq_start(seq, pos, &clip_tbl, NEIGH_SEQ_NEIGH_ONLY);
 902 }
 903
 904 static int clip_seq_show(struct seq_file *seq, void *v)
 905 {
 906         static char atm_arp_banner[] =
 907             "IPitf TypeEncp Idle IP address      ATM address\n";
 908
 909         if (v == SEQ_START_TOKEN) {
 910                 seq_puts(seq, atm_arp_banner);
 911         } else {
 912                 struct clip_seq_state *state = seq->private;
 913                 struct neighbour *n = v;
 914                 struct clip_vcc *vcc = state->vcc;
 915
 916                 atmarp_info(seq, n->dev, NEIGH2ENTRY(n), vcc);
 917         }
 918         return 0;
 919 }
 920
 921 static struct seq_operations arp_seq_ops = {
 922         .start  = clip_seq_start,
 923         .next   = neigh_seq_next,
 924         .stop   = neigh_seq_stop,
 925         .show   = clip_seq_show,
 926 };
 927
 928 static int arp_seq_open(struct inode *inode, struct file *file)
 929 {
 930         struct clip_seq_state *state;
 931         struct seq_file *seq;
 932         int rc = -EAGAIN;
 933
 934         state = kzalloc(sizeof(*state), GFP_KERNEL);
 935         if (!state) {
 936                 rc = -ENOMEM;
 937                 goto out_kfree;
 938         }
 939         state->ns.neigh_sub_iter = clip_seq_sub_iter;
 940
 941         rc = seq_open(file, &arp_seq_ops);
 942         if (rc)
 943                 goto out_kfree;
 944
 945         seq = file->private_data;
 946         seq->private = state;
 947 out:
 948         return rc;
 949
 950 out_kfree:
 951         kfree(state);
 952         goto out;
 953 }
 954
 955 static struct file_operations arp_seq_fops = {
 956         .open           = arp_seq_open,
 957         .read           = seq_read,
 958         .llseek         = seq_lseek,
 959         .release        = seq_release_private,
 960         .owner          = THIS_MODULE
 961 };
 962 #endif
 963
 964 static int __init atm_clip_init(void)
 965 {
 966         neigh_table_init_no_netlink(&clip_tbl);
 967
 968         clip_tbl_hook = &clip_tbl;
 969         register_atm_ioctl(&clip_ioctl_ops);
 970         register_netdevice_notifier(&clip_dev_notifier);
 971         register_inetaddr_notifier(&clip_inet_notifier);
 972
 973         setup_timer(&idle_timer, idle_timer_check, 0);
 974
 975 #ifdef CONFIG_PROC_FS
 976         {
 977                 struct proc_dir_entry *p;
 978
 979                 p = create_proc_entry("arp", S_IRUGO, atm_proc_root);
 980                 if (p)
 981                         p->proc_fops = &arp_seq_fops;
 982         }
 983 #endif
 984
 985         return 0;
 986 }
 987
 988 static void __exit atm_clip_exit(void)
 989 {
 990         struct net_device *dev, *next;
 991
 992         remove_proc_entry("arp", atm_proc_root);
 993
 994         unregister_inetaddr_notifier(&clip_inet_notifier);
 995         unregister_netdevice_notifier(&clip_dev_notifier);
 996
 997         deregister_atm_ioctl(&clip_ioctl_ops);
 998
 999         /* First, stop the idle timer, so it stops banging
1000          * on the table.
1001          */
1002         del_timer_sync(&idle_timer);
1003
1004         /* Next, purge the table, so that the device
1005          * unregister loop below does not hang due to
1006          * device references remaining in the table.
1007          */
1008         neigh_ifdown(&clip_tbl, NULL);
1009
1010         dev = clip_devs;
1011         while (dev) {
1012                 next = PRIV(dev)->next;
1013                 unregister_netdev(dev);
1014                 free_netdev(dev);
1015                 dev = next;
1016         }
1017
1018         /* Now it is safe to fully shutdown whole table. */
1019         neigh_table_clear(&clip_tbl);
1020
1021         clip_tbl_hook = NULL;
1022 }
1023
1024 module_init(atm_clip_init);
1025 module_exit(atm_clip_exit);
1026 MODULE_AUTHOR("Werner Almesberger");
1027 MODULE_DESCRIPTION("Classical/IP over ATM interface");
1028 MODULE_LICENSE("GPL");