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   1 /* net/atm/clip.c - RFC1577 Classical IP over ATM */
   2
   3 /* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */
   4
   5
   6 #include <linux/config.h>
   7 #include <linux/string.h>
   8 #include <linux/errno.h>
   9 #include <linux/kernel.h> /* for UINT_MAX */
  10 #include <linux/module.h>
  11 #include <linux/init.h>
  12 #include <linux/netdevice.h>
  13 #include <linux/skbuff.h>
  14 #include <linux/wait.h>
  15 #include <linux/timer.h>
  16 #include <linux/if_arp.h> /* for some manifest constants */
  17 #include <linux/notifier.h>
  18 #include <linux/atm.h>
  19 #include <linux/atmdev.h>
  20 #include <linux/atmclip.h>
  21 #include <linux/atmarp.h>
  22 #include <linux/capability.h>
  23 #include <linux/ip.h> /* for net/route.h */
  24 #include <linux/in.h> /* for struct sockaddr_in */
  25 #include <linux/if.h> /* for IFF_UP */
  26 #include <linux/inetdevice.h>
  27 #include <linux/bitops.h>
  28 #include <linux/proc_fs.h>
  29 #include <linux/seq_file.h>
  30 #include <linux/rcupdate.h>
  31 #include <linux/jhash.h>
  32 #include <net/route.h> /* for struct rtable and routing */
  33 #include <net/icmp.h> /* icmp_send */
  34 #include <asm/param.h> /* for HZ */
  35 #include <asm/byteorder.h> /* for htons etc. */
  36 #include <asm/system.h> /* save/restore_flags */
  37 #include <asm/uaccess.h>
  38 #include <asm/atomic.h>
  39
  40 #include "common.h"
  41 #include "resources.h"
  42 #include "ipcommon.h"
  43 #include <net/atmclip.h>
  44
  45
  46 #if 0
  47 #define DPRINTK(format,args...) printk(format,##args)
  48 #else
  49 #define DPRINTK(format,args...)
  50 #endif
  51
  52
  53 static struct net_device *clip_devs;
  54 static struct atm_vcc *atmarpd;
  55 static struct neigh_table clip_tbl;
  56 static struct timer_list idle_timer;
  57 static int start_timer = 1;
  58
  59
  60 static int to_atmarpd(enum atmarp_ctrl_type type,int itf,unsigned long ip)
  61 {
  62         struct sock *sk;
  63         struct atmarp_ctrl *ctrl;
  64         struct sk_buff *skb;
  65
  66         DPRINTK("to_atmarpd(%d)\n",type);
  67         if (!atmarpd) return -EUNATCH;
  68         skb = alloc_skb(sizeof(struct atmarp_ctrl),GFP_ATOMIC);
  69         if (!skb) return -ENOMEM;
  70         ctrl = (struct atmarp_ctrl *) skb_put(skb,sizeof(struct atmarp_ctrl));
  71         ctrl->type = type;
  72         ctrl->itf_num = itf;
  73         ctrl->ip = ip;
  74         atm_force_charge(atmarpd,skb->truesize);
  75
  76         sk = sk_atm(atmarpd);
  77         skb_queue_tail(&sk->sk_receive_queue, skb);
  78         sk->sk_data_ready(sk, skb->len);
  79         return 0;
  80 }
  81
  82
  83 static void link_vcc(struct clip_vcc *clip_vcc,struct atmarp_entry *entry)
  84 {
  85         DPRINTK("link_vcc %p to entry %p (neigh %p)\n",clip_vcc,entry,
  86             entry->neigh);
  87         clip_vcc->entry = entry;
  88         clip_vcc->xoff = 0; /* @@@ may overrun buffer by one packet */
  89         clip_vcc->next = entry->vccs;
  90         entry->vccs = clip_vcc;
  91         entry->neigh->used = jiffies;
  92 }
  93
  94
  95 static void unlink_clip_vcc(struct clip_vcc *clip_vcc)
  96 {
  97         struct atmarp_entry *entry = clip_vcc->entry;
  98         struct clip_vcc **walk;
  99
 100         if (!entry) {
 101                 printk(KERN_CRIT "!clip_vcc->entry (clip_vcc %p)\n",clip_vcc);
 102                 return;
 103         }
 104         spin_lock_bh(&entry->neigh->dev->xmit_lock);    /* block clip_start_xmit() */
 105         entry->neigh->used = jiffies;
 106         for (walk = &entry->vccs; *walk; walk = &(*walk)->next)
 107                 if (*walk == clip_vcc) {
 108                         int error;
 109
 110                         *walk = clip_vcc->next; /* atomic */
 111                         clip_vcc->entry = NULL;
 112                         if (clip_vcc->xoff)
 113                                 netif_wake_queue(entry->neigh->dev);
 114                         if (entry->vccs)
 115                                 goto out;
 116                         entry->expires = jiffies-1;
 117                                 /* force resolution or expiration */
 118                         error = neigh_update(entry->neigh, NULL, NUD_NONE,
 119                                              NEIGH_UPDATE_F_ADMIN);
 120                         if (error)
 121                                 printk(KERN_CRIT "unlink_clip_vcc: "
 122                                     "neigh_update failed with %d\n",error);
 123                         goto out;
 124                 }
 125         printk(KERN_CRIT "ATMARP: unlink_clip_vcc failed (entry %p, vcc "
 126           "0x%p)\n",entry,clip_vcc);
 127 out:
 128         spin_unlock_bh(&entry->neigh->dev->xmit_lock);
 129 }
 130
 131 /* The neighbour entry n->lock is held. */
 132 static int neigh_check_cb(struct neighbour *n)
 133 {
 134         struct atmarp_entry *entry = NEIGH2ENTRY(n);
 135         struct clip_vcc *cv;
 136
 137         for (cv = entry->vccs; cv; cv = cv->next) {
 138                 unsigned long exp = cv->last_use + cv->idle_timeout;
 139
 140                 if (cv->idle_timeout && time_after(jiffies, exp)) {
 141                         DPRINTK("releasing vcc %p->%p of entry %p\n",
 142                                 cv, cv->vcc, entry);
 143                         vcc_release_async(cv->vcc, -ETIMEDOUT);
 144                 }
 145         }
 146
 147         if (entry->vccs || time_before(jiffies, entry->expires))
 148                 return 0;
 149
 150         if (atomic_read(&n->refcnt) > 1) {
 151                 struct sk_buff *skb;
 152
 153                 DPRINTK("destruction postponed with ref %d\n",
 154                         atomic_read(&n->refcnt));
 155
 156                 while ((skb = skb_dequeue(&n->arp_queue)) != NULL)
 157                         dev_kfree_skb(skb);
 158
 159                 return 0;
 160         }
 161
 162         DPRINTK("expired neigh %p\n",n);
 163         return 1;
 164 }
 165
 166 static void idle_timer_check(unsigned long dummy)
 167 {
 168         write_lock(&clip_tbl.lock);
 169         __neigh_for_each_release(&clip_tbl, neigh_check_cb);
 170         mod_timer(&idle_timer, jiffies+CLIP_CHECK_INTERVAL*HZ);
 171         write_unlock(&clip_tbl.lock);
 172 }
 173
 174 static int clip_arp_rcv(struct sk_buff *skb)
 175 {
 176         struct atm_vcc *vcc;
 177
 178         DPRINTK("clip_arp_rcv\n");
 179         vcc = ATM_SKB(skb)->vcc;
 180         if (!vcc || !atm_charge(vcc,skb->truesize)) {
 181                 dev_kfree_skb_any(skb);
 182                 return 0;
 183         }
 184         DPRINTK("pushing to %p\n",vcc);
 185         DPRINTK("using %p\n",CLIP_VCC(vcc)->old_push);
 186         CLIP_VCC(vcc)->old_push(vcc,skb);
 187         return 0;
 188 }
 189
 190 static const unsigned char llc_oui[] = {
 191         0xaa,   /* DSAP: non-ISO */
 192         0xaa,   /* SSAP: non-ISO */
 193         0x03,   /* Ctrl: Unnumbered Information Command PDU */
 194         0x00,   /* OUI: EtherType */
 195         0x00,
 196         0x00 };
 197
 198 static void clip_push(struct atm_vcc *vcc,struct sk_buff *skb)
 199 {
 200         struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
 201
 202         DPRINTK("clip push\n");
 203         if (!skb) {
 204                 DPRINTK("removing VCC %p\n",clip_vcc);
 205                 if (clip_vcc->entry) unlink_clip_vcc(clip_vcc);
 206                 clip_vcc->old_push(vcc,NULL); /* pass on the bad news */
 207                 kfree(clip_vcc);
 208                 return;
 209         }
 210         atm_return(vcc,skb->truesize);
 211         skb->dev = clip_vcc->entry ? clip_vcc->entry->neigh->dev : clip_devs;
 212                 /* clip_vcc->entry == NULL if we don't have an IP address yet */
 213         if (!skb->dev) {
 214                 dev_kfree_skb_any(skb);
 215                 return;
 216         }
 217         ATM_SKB(skb)->vcc = vcc;
 218         skb->mac.raw = skb->data;
 219         if (!clip_vcc->encap || skb->len < RFC1483LLC_LEN || memcmp(skb->data,
 220             llc_oui,sizeof(llc_oui))) skb->protocol = htons(ETH_P_IP);
 221         else {
 222                 skb->protocol = ((u16 *) skb->data)[3];
 223                 skb_pull(skb,RFC1483LLC_LEN);
 224                 if (skb->protocol == htons(ETH_P_ARP)) {
 225                         PRIV(skb->dev)->stats.rx_packets++;
 226                         PRIV(skb->dev)->stats.rx_bytes += skb->len;
 227                         clip_arp_rcv(skb);
 228                         return;
 229                 }
 230         }
 231         clip_vcc->last_use = jiffies;
 232         PRIV(skb->dev)->stats.rx_packets++;
 233         PRIV(skb->dev)->stats.rx_bytes += skb->len;
 234         memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
 235         netif_rx(skb);
 236 }
 237
 238
 239 /*
 240  * Note: these spinlocks _must_not_ block on non-SMP. The only goal is that
 241  * clip_pop is atomic with respect to the critical section in clip_start_xmit.
 242  */
 243
 244
 245 static void clip_pop(struct atm_vcc *vcc,struct sk_buff *skb)
 246 {
 247         struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
 248         struct net_device *dev = skb->dev;
 249         int old;
 250         unsigned long flags;
 251
 252         DPRINTK("clip_pop(vcc %p)\n",vcc);
 253         clip_vcc->old_pop(vcc,skb);
 254         /* skb->dev == NULL in outbound ARP packets */
 255         if (!dev) return;
 256         spin_lock_irqsave(&PRIV(dev)->xoff_lock,flags);
 257         if (atm_may_send(vcc,0)) {
 258                 old = xchg(&clip_vcc->xoff,0);
 259                 if (old) netif_wake_queue(dev);
 260         }
 261         spin_unlock_irqrestore(&PRIV(dev)->xoff_lock,flags);
 262 }
 263
 264
 265 static void clip_neigh_destroy(struct neighbour *neigh)
 266 {
 267         DPRINTK("clip_neigh_destroy (neigh %p)\n",neigh);
 268         if (NEIGH2ENTRY(neigh)->vccs)
 269                 printk(KERN_CRIT "clip_neigh_destroy: vccs != NULL !!!\n");
 270         NEIGH2ENTRY(neigh)->vccs = (void *) 0xdeadbeef;
 271 }
 272
 273
 274 static void clip_neigh_solicit(struct neighbour *neigh,struct sk_buff *skb)
 275 {
 276         DPRINTK("clip_neigh_solicit (neigh %p, skb %p)\n",neigh,skb);
 277         to_atmarpd(act_need,PRIV(neigh->dev)->number,NEIGH2ENTRY(neigh)->ip);
 278 }
 279
 280
 281 static void clip_neigh_error(struct neighbour *neigh,struct sk_buff *skb)
 282 {
 283 #ifndef CONFIG_ATM_CLIP_NO_ICMP
 284         icmp_send(skb,ICMP_DEST_UNREACH,ICMP_HOST_UNREACH,0);
 285 #endif
 286         kfree_skb(skb);
 287 }
 288
 289
 290 static struct neigh_ops clip_neigh_ops = {
 291         .family =               AF_INET,
 292         .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 = __in_dev_get_rcu(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                 .neigh_destructor       = clip_neigh_destroy,
 350                 .base_reachable_time    = 30 * HZ,
 351                 .retrans_time           = 1 * HZ,
 352                 .gc_staletime           = 60 * HZ,
 353                 .reachable_time         = 30 * HZ,
 354                 .delay_probe_time       = 5 * HZ,
 355                 .queue_len              = 3,
 356                 .ucast_probes           = 3,
 357                 .mcast_probes           = 3,
 358                 .anycast_delay          = 1 * HZ,
 359                 .proxy_delay            = (8 * HZ) / 10,
 360                 .proxy_qlen             = 64,
 361                 .locktime               = 1 * HZ,
 362         },
 363         .gc_interval    = 30 * HZ,
 364         .gc_thresh1     = 128,
 365         .gc_thresh2     = 512,
 366         .gc_thresh3     = 1024,
 367 };
 368
 369
 370 /* @@@ copy bh locking from arp.c -- need to bh-enable atm code before */
 371
 372 /*
 373  * We play with the resolve flag: 0 and 1 have the usual meaning, but -1 means
 374  * to allocate the neighbour entry but not to ask atmarpd for resolution. Also,
 375  * don't increment the usage count. This is used to create entries in
 376  * clip_setentry.
 377  */
 378
 379
 380 static int clip_encap(struct atm_vcc *vcc,int mode)
 381 {
 382         CLIP_VCC(vcc)->encap = mode;
 383         return 0;
 384 }
 385
 386
 387 static int clip_start_xmit(struct sk_buff *skb,struct net_device *dev)
 388 {
 389         struct clip_priv *clip_priv = PRIV(dev);
 390         struct atmarp_entry *entry;
 391         struct atm_vcc *vcc;
 392         int old;
 393         unsigned long flags;
 394
 395         DPRINTK("clip_start_xmit (skb %p)\n",skb);
 396         if (!skb->dst) {
 397                 printk(KERN_ERR "clip_start_xmit: skb->dst == NULL\n");
 398                 dev_kfree_skb(skb);
 399                 clip_priv->stats.tx_dropped++;
 400                 return 0;
 401         }
 402         if (!skb->dst->neighbour) {
 403 #if 0
 404                 skb->dst->neighbour = clip_find_neighbour(skb->dst,1);
 405                 if (!skb->dst->neighbour) {
 406                         dev_kfree_skb(skb); /* lost that one */
 407                         clip_priv->stats.tx_dropped++;
 408                         return 0;
 409                 }
 410 #endif
 411                 printk(KERN_ERR "clip_start_xmit: NO NEIGHBOUR !\n");
 412                 dev_kfree_skb(skb);
 413                 clip_priv->stats.tx_dropped++;
 414                 return 0;
 415         }
 416         entry = NEIGH2ENTRY(skb->dst->neighbour);
 417         if (!entry->vccs) {
 418                 if (time_after(jiffies, entry->expires)) {
 419                         /* should be resolved */
 420                         entry->expires = jiffies+ATMARP_RETRY_DELAY*HZ;
 421                         to_atmarpd(act_need,PRIV(dev)->number,entry->ip);
 422                 }
 423                 if (entry->neigh->arp_queue.qlen < ATMARP_MAX_UNRES_PACKETS)
 424                         skb_queue_tail(&entry->neigh->arp_queue,skb);
 425                 else {
 426                         dev_kfree_skb(skb);
 427                         clip_priv->stats.tx_dropped++;
 428                 }
 429                 return 0;
 430         }
 431         DPRINTK("neigh %p, vccs %p\n",entry,entry->vccs);
 432         ATM_SKB(skb)->vcc = vcc = entry->vccs->vcc;
 433         DPRINTK("using neighbour %p, vcc %p\n",skb->dst->neighbour,vcc);
 434         if (entry->vccs->encap) {
 435                 void *here;
 436
 437                 here = skb_push(skb,RFC1483LLC_LEN);
 438                 memcpy(here,llc_oui,sizeof(llc_oui));
 439                 ((u16 *) here)[3] = skb->protocol;
 440         }
 441         atomic_add(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
 442         ATM_SKB(skb)->atm_options = vcc->atm_options;
 443         entry->vccs->last_use = jiffies;
 444         DPRINTK("atm_skb(%p)->vcc(%p)->dev(%p)\n",skb,vcc,vcc->dev);
 445         old = xchg(&entry->vccs->xoff,1); /* assume XOFF ... */
 446         if (old) {
 447                 printk(KERN_WARNING "clip_start_xmit: XOFF->XOFF transition\n");
 448                 return 0;
 449         }
 450         clip_priv->stats.tx_packets++;
 451         clip_priv->stats.tx_bytes += skb->len;
 452         (void) vcc->send(vcc,skb);
 453         if (atm_may_send(vcc,0)) {
 454                 entry->vccs->xoff = 0;
 455                 return 0;
 456         }
 457         spin_lock_irqsave(&clip_priv->xoff_lock,flags);
 458         netif_stop_queue(dev); /* XOFF -> throttle immediately */
 459         barrier();
 460         if (!entry->vccs->xoff)
 461                 netif_start_queue(dev);
 462                 /* Oh, we just raced with clip_pop. netif_start_queue should be
 463                    good enough, because nothing should really be asleep because
 464                    of the brief netif_stop_queue. If this isn't true or if it
 465                    changes, use netif_wake_queue instead. */
 466         spin_unlock_irqrestore(&clip_priv->xoff_lock,flags);
 467         return 0;
 468 }
 469
 470
 471 static struct net_device_stats *clip_get_stats(struct net_device *dev)
 472 {
 473         return &PRIV(dev)->stats;
 474 }
 475
 476
 477 static int clip_mkip(struct atm_vcc *vcc,int timeout)
 478 {
 479         struct clip_vcc *clip_vcc;
 480         struct sk_buff_head copy;
 481         struct sk_buff *skb;
 482
 483         if (!vcc->push) return -EBADFD;
 484         clip_vcc = kmalloc(sizeof(struct clip_vcc),GFP_KERNEL);
 485         if (!clip_vcc) return -ENOMEM;
 486         DPRINTK("mkip clip_vcc %p vcc %p\n",clip_vcc,vcc);
 487         clip_vcc->vcc = vcc;
 488         vcc->user_back = clip_vcc;
 489         set_bit(ATM_VF_IS_CLIP, &vcc->flags);
 490         clip_vcc->entry = NULL;
 491         clip_vcc->xoff = 0;
 492         clip_vcc->encap = 1;
 493         clip_vcc->last_use = jiffies;
 494         clip_vcc->idle_timeout = timeout*HZ;
 495         clip_vcc->old_push = vcc->push;
 496         clip_vcc->old_pop = vcc->pop;
 497         vcc->push = clip_push;
 498         vcc->pop = clip_pop;
 499         skb_queue_head_init(&copy);
 500         skb_migrate(&sk_atm(vcc)->sk_receive_queue, &copy);
 501         /* re-process everything received between connection setup and MKIP */
 502         while ((skb = skb_dequeue(&copy)) != NULL)
 503                 if (!clip_devs) {
 504                         atm_return(vcc,skb->truesize);
 505                         kfree_skb(skb);
 506                 }
 507                 else {
 508                         unsigned int len = skb->len;
 509
 510                         clip_push(vcc,skb);
 511                         PRIV(skb->dev)->stats.rx_packets--;
 512                         PRIV(skb->dev)->stats.rx_bytes -= len;
 513                 }
 514         return 0;
 515 }
 516
 517
 518 static int clip_setentry(struct atm_vcc *vcc,u32 ip)
 519 {
 520         struct neighbour *neigh;
 521         struct atmarp_entry *entry;
 522         int error;
 523         struct clip_vcc *clip_vcc;
 524         struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, .tos = 1 } } };
 525         struct rtable *rt;
 526
 527         if (vcc->push != clip_push) {
 528                 printk(KERN_WARNING "clip_setentry: non-CLIP VCC\n");
 529                 return -EBADF;
 530         }
 531         clip_vcc = CLIP_VCC(vcc);
 532         if (!ip) {
 533                 if (!clip_vcc->entry) {
 534                         printk(KERN_ERR "hiding hidden ATMARP entry\n");
 535                         return 0;
 536                 }
 537                 DPRINTK("setentry: remove\n");
 538                 unlink_clip_vcc(clip_vcc);
 539                 return 0;
 540         }
 541         error = ip_route_output_key(&rt,&fl);
 542         if (error) return error;
 543         neigh = __neigh_lookup(&clip_tbl,&ip,rt->u.dst.dev,1);
 544         ip_rt_put(rt);
 545         if (!neigh)
 546                 return -ENOMEM;
 547         entry = NEIGH2ENTRY(neigh);
 548         if (entry != clip_vcc->entry) {
 549                 if (!clip_vcc->entry) DPRINTK("setentry: add\n");
 550                 else {
 551                         DPRINTK("setentry: update\n");
 552                         unlink_clip_vcc(clip_vcc);
 553                 }
 554                 link_vcc(clip_vcc,entry);
 555         }
 556         error = neigh_update(neigh, llc_oui, NUD_PERMANENT,
 557                              NEIGH_UPDATE_F_OVERRIDE|NEIGH_UPDATE_F_ADMIN);
 558         neigh_release(neigh);
 559         return error;
 560 }
 561
 562
 563 static void clip_setup(struct net_device *dev)
 564 {
 565         dev->hard_start_xmit = clip_start_xmit;
 566         /* sg_xmit ... */
 567         dev->get_stats = clip_get_stats;
 568         dev->type = ARPHRD_ATM;
 569         dev->hard_header_len = RFC1483LLC_LEN;
 570         dev->mtu = RFC1626_MTU;
 571         dev->tx_queue_len = 100; /* "normal" queue (packets) */
 572             /* When using a "real" qdisc, the qdisc determines the queue */
 573             /* length. tx_queue_len is only used for the default case, */
 574             /* without any more elaborate queuing. 100 is a reasonable */
 575             /* compromise between decent burst-tolerance and protection */
 576             /* against memory hogs. */
 577 }
 578
 579
 580 static int clip_create(int number)
 581 {
 582         struct net_device *dev;
 583         struct clip_priv *clip_priv;
 584         int error;
 585
 586         if (number != -1) {
 587                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
 588                         if (PRIV(dev)->number == number) return -EEXIST;
 589         }
 590         else {
 591                 number = 0;
 592                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
 593                         if (PRIV(dev)->number >= number)
 594                                 number = PRIV(dev)->number+1;
 595         }
 596         dev = alloc_netdev(sizeof(struct clip_priv), "", clip_setup);
 597         if (!dev)
 598                 return -ENOMEM;
 599         clip_priv = PRIV(dev);
 600         sprintf(dev->name,"atm%d",number);
 601         spin_lock_init(&clip_priv->xoff_lock);
 602         clip_priv->number = number;
 603         error = register_netdev(dev);
 604         if (error) {
 605                 free_netdev(dev);
 606                 return error;
 607         }
 608         clip_priv->next = clip_devs;
 609         clip_devs = dev;
 610         DPRINTK("registered (net:%s)\n",dev->name);
 611         return number;
 612 }
 613
 614
 615 static int clip_device_event(struct notifier_block *this,unsigned long event,
 616     void *dev)
 617 {
 618         /* ignore non-CLIP devices */
 619         if (((struct net_device *) dev)->type != ARPHRD_ATM ||
 620             ((struct net_device *) dev)->hard_start_xmit != clip_start_xmit)
 621                 return NOTIFY_DONE;
 622         switch (event) {
 623                 case NETDEV_UP:
 624                         DPRINTK("clip_device_event NETDEV_UP\n");
 625                         (void) to_atmarpd(act_up,PRIV(dev)->number,0);
 626                         break;
 627                 case NETDEV_GOING_DOWN:
 628                         DPRINTK("clip_device_event NETDEV_DOWN\n");
 629                         (void) 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                         (void) to_atmarpd(act_change,PRIV(dev)->number,0);
 635                         break;
 636                 case NETDEV_REBOOT:
 637                 case NETDEV_REGISTER:
 638                 case NETDEV_DOWN:
 639                         DPRINTK("clip_device_event %ld\n",event);
 640                         /* ignore */
 641                         break;
 642                 default:
 643                         printk(KERN_WARNING "clip_device_event: unknown event "
 644                             "%ld\n",event);
 645                         break;
 646         }
 647         return NOTIFY_DONE;
 648 }
 649
 650
 651 static int clip_inet_event(struct notifier_block *this,unsigned long event,
 652     void *ifa)
 653 {
 654         struct in_device *in_dev;
 655
 656         in_dev = ((struct in_ifaddr *) ifa)->ifa_dev;
 657         if (!in_dev || !in_dev->dev) {
 658                 printk(KERN_WARNING "clip_inet_event: no device\n");
 659                 return NOTIFY_DONE;
 660         }
 661         /*
 662          * Transitions are of the down-change-up type, so it's sufficient to
 663          * handle the change on up.
 664          */
 665         if (event != NETDEV_UP) 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         clip_device_event,
 672         NULL,
 673         0
 674 };
 675
 676
 677
 678 static struct notifier_block clip_inet_notifier = {
 679         clip_inet_event,
 680         NULL,
 681         0
 682 };
 683
 684
 685
 686 static void atmarpd_close(struct atm_vcc *vcc)
 687 {
 688         DPRINTK("atmarpd_close\n");
 689         atmarpd = NULL; /* assumed to be atomic */
 690         barrier();
 691         unregister_inetaddr_notifier(&clip_inet_notifier);
 692         unregister_netdevice_notifier(&clip_dev_notifier);
 693         if (skb_peek(&sk_atm(vcc)->sk_receive_queue))
 694                 printk(KERN_ERR "atmarpd_close: closing with requests "
 695                     "pending\n");
 696         skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
 697         DPRINTK("(done)\n");
 698         module_put(THIS_MODULE);
 699 }
 700
 701
 702 static struct atmdev_ops atmarpd_dev_ops = {
 703         .close = atmarpd_close
 704 };
 705
 706
 707 static struct atm_dev atmarpd_dev = {
 708         .ops =                  &atmarpd_dev_ops,
 709         .type =                 "arpd",
 710         .number =               999,
 711         .lock =                 SPIN_LOCK_UNLOCKED
 712 };
 713
 714
 715 static int atm_init_atmarp(struct atm_vcc *vcc)
 716 {
 717         if (atmarpd) return -EADDRINUSE;
 718         if (start_timer) {
 719                 start_timer = 0;
 720                 init_timer(&idle_timer);
 721                 idle_timer.expires = jiffies+CLIP_CHECK_INTERVAL*HZ;
 722                 idle_timer.function = idle_timer_check;
 723                 add_timer(&idle_timer);
 724         }
 725         atmarpd = vcc;
 726         set_bit(ATM_VF_META,&vcc->flags);
 727         set_bit(ATM_VF_READY,&vcc->flags);
 728             /* allow replies and avoid getting closed if signaling dies */
 729         vcc->dev = &atmarpd_dev;
 730         vcc_insert_socket(sk_atm(vcc));
 731         vcc->push = NULL;
 732         vcc->pop = NULL; /* crash */
 733         vcc->push_oam = NULL; /* crash */
 734         if (register_netdevice_notifier(&clip_dev_notifier))
 735                 printk(KERN_ERR "register_netdevice_notifier failed\n");
 736         if (register_inetaddr_notifier(&clip_inet_notifier))
 737                 printk(KERN_ERR "register_inetaddr_notifier failed\n");
 738         return 0;
 739 }
 740
 741 static int clip_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 742 {
 743         struct atm_vcc *vcc = ATM_SD(sock);
 744         int err = 0;
 745
 746         switch (cmd) {
 747                 case SIOCMKCLIP:
 748                 case ATMARPD_CTRL:
 749                 case ATMARP_MKIP:
 750                 case ATMARP_SETENTRY:
 751                 case ATMARP_ENCAP:
 752                         if (!capable(CAP_NET_ADMIN))
 753                                 return -EPERM;
 754                         break;
 755                 default:
 756                         return -ENOIOCTLCMD;
 757         }
 758
 759         switch (cmd) {
 760                 case SIOCMKCLIP:
 761                         err = clip_create(arg);
 762                         break;
 763                 case ATMARPD_CTRL:
 764                         err = atm_init_atmarp(vcc);
 765                         if (!err) {
 766                                 sock->state = SS_CONNECTED;
 767                                 __module_get(THIS_MODULE);
 768                         }
 769                         break;
 770                 case ATMARP_MKIP:
 771                         err = clip_mkip(vcc ,arg);
 772                         break;
 773                 case ATMARP_SETENTRY:
 774                         err = clip_setentry(vcc, arg);
 775                         break;
 776                 case ATMARP_ENCAP:
 777                         err = clip_encap(vcc, arg);
 778                         break;
 779         }
 780         return err;
 781 }
 782
 783 static struct atm_ioctl clip_ioctl_ops = {
 784         .owner  = THIS_MODULE,
 785         .ioctl  = clip_ioctl,
 786 };
 787
 788 #ifdef CONFIG_PROC_FS
 789
 790 static void svc_addr(struct seq_file *seq, struct sockaddr_atmsvc *addr)
 791 {
 792         static int code[] = { 1,2,10,6,1,0 };
 793         static int e164[] = { 1,8,4,6,1,0 };
 794
 795         if (*addr->sas_addr.pub) {
 796                 seq_printf(seq, "%s", addr->sas_addr.pub);
 797                 if (*addr->sas_addr.prv)
 798                         seq_putc(seq, '+');
 799         } else if (!*addr->sas_addr.prv) {
 800                 seq_printf(seq, "%s", "(none)");
 801                 return;
 802         }
 803         if (*addr->sas_addr.prv) {
 804                 unsigned char *prv = addr->sas_addr.prv;
 805                 int *fields;
 806                 int i, j;
 807
 808                 fields = *prv == ATM_AFI_E164 ? e164 : code;
 809                 for (i = 0; fields[i]; i++) {
 810                         for (j = fields[i]; j; j--)
 811                                 seq_printf(seq, "%02X", *prv++);
 812                         if (fields[i+1])
 813                                 seq_putc(seq, '.');
 814                 }
 815         }
 816 }
 817
 818 /* This means the neighbour entry has no attached VCC objects. */
 819 #define SEQ_NO_VCC_TOKEN        ((void *) 2)
 820
 821 static void atmarp_info(struct seq_file *seq, struct net_device *dev,
 822                         struct atmarp_entry *entry, struct clip_vcc *clip_vcc)
 823 {
 824         unsigned long exp;
 825         char buf[17];
 826         int svc, llc, off;
 827
 828         svc = ((clip_vcc == SEQ_NO_VCC_TOKEN) ||
 829                (sk_atm(clip_vcc->vcc)->sk_family == AF_ATMSVC));
 830
 831         llc = ((clip_vcc == SEQ_NO_VCC_TOKEN) ||
 832                clip_vcc->encap);
 833
 834         if (clip_vcc == SEQ_NO_VCC_TOKEN)
 835                 exp = entry->neigh->used;
 836         else
 837                 exp = clip_vcc->last_use;
 838
 839         exp = (jiffies - exp) / HZ;
 840
 841         seq_printf(seq, "%-6s%-4s%-4s%5ld ",
 842                    dev->name,
 843                    svc ? "SVC" : "PVC",
 844                    llc ? "LLC" : "NULL",
 845                    exp);
 846
 847         off = scnprintf(buf, sizeof(buf) - 1, "%d.%d.%d.%d",
 848                         NIPQUAD(entry->ip));
 849         while (off < 16)
 850                 buf[off++] = ' ';
 851         buf[off] = '\0';
 852         seq_printf(seq, "%s", buf);
 853
 854         if (clip_vcc == SEQ_NO_VCC_TOKEN) {
 855                 if (time_before(jiffies, entry->expires))
 856                         seq_printf(seq, "(resolving)\n");
 857                 else
 858                         seq_printf(seq, "(expired, ref %d)\n",
 859                                    atomic_read(&entry->neigh->refcnt));
 860         } else if (!svc) {
 861                 seq_printf(seq, "%d.%d.%d\n",
 862                            clip_vcc->vcc->dev->number,
 863                            clip_vcc->vcc->vpi,
 864                            clip_vcc->vcc->vci);
 865         } else {
 866                 svc_addr(seq, &clip_vcc->vcc->remote);
 867                 seq_putc(seq, '\n');
 868         }
 869 }
 870
 871 struct clip_seq_state {
 872         /* This member must be first. */
 873         struct neigh_seq_state ns;
 874
 875         /* Local to clip specific iteration. */
 876         struct clip_vcc *vcc;
 877 };
 878
 879 static struct clip_vcc *clip_seq_next_vcc(struct atmarp_entry *e,
 880                                           struct clip_vcc *curr)
 881 {
 882         if (!curr) {
 883                 curr = e->vccs;
 884                 if (!curr)
 885                         return SEQ_NO_VCC_TOKEN;
 886                 return curr;
 887         }
 888         if (curr == SEQ_NO_VCC_TOKEN)
 889                 return NULL;
 890
 891         curr = curr->next;
 892
 893         return curr;
 894 }
 895
 896 static void *clip_seq_vcc_walk(struct clip_seq_state *state,
 897                                struct atmarp_entry *e, loff_t *pos)
 898 {
 899         struct clip_vcc *vcc = state->vcc;
 900
 901         vcc = clip_seq_next_vcc(e, vcc);
 902         if (vcc && pos != NULL) {
 903                 while (*pos) {
 904                         vcc = clip_seq_next_vcc(e, vcc);
 905                         if (!vcc)
 906                                 break;
 907                         --(*pos);
 908                 }
 909         }
 910         state->vcc = vcc;
 911
 912         return vcc;
 913 }
 914
 915 static void *clip_seq_sub_iter(struct neigh_seq_state *_state,
 916                                struct neighbour *n, loff_t *pos)
 917 {
 918         struct clip_seq_state *state = (struct clip_seq_state *) _state;
 919
 920         return clip_seq_vcc_walk(state, NEIGH2ENTRY(n), pos);
 921 }
 922
 923 static void *clip_seq_start(struct seq_file *seq, loff_t *pos)
 924 {
 925         return neigh_seq_start(seq, pos, &clip_tbl, NEIGH_SEQ_NEIGH_ONLY);
 926 }
 927
 928 static int clip_seq_show(struct seq_file *seq, void *v)
 929 {
 930         static char atm_arp_banner[] =
 931                 "IPitf TypeEncp Idle IP address      ATM address\n";
 932
 933         if (v == SEQ_START_TOKEN) {
 934                 seq_puts(seq, atm_arp_banner);
 935         } else {
 936                 struct clip_seq_state *state = seq->private;
 937                 struct neighbour *n = v;
 938                 struct clip_vcc *vcc = state->vcc;
 939
 940                 atmarp_info(seq, n->dev, NEIGH2ENTRY(n), vcc);
 941         }
 942         return 0;
 943 }
 944
 945 static struct seq_operations arp_seq_ops = {
 946         .start  = clip_seq_start,
 947         .next   = neigh_seq_next,
 948         .stop   = neigh_seq_stop,
 949         .show   = clip_seq_show,
 950 };
 951
 952 static int arp_seq_open(struct inode *inode, struct file *file)
 953 {
 954         struct clip_seq_state *state;
 955         struct seq_file *seq;
 956         int rc = -EAGAIN;
 957
 958         state = kmalloc(sizeof(*state), GFP_KERNEL);
 959         if (!state) {
 960                 rc = -ENOMEM;
 961                 goto out_kfree;
 962         }
 963         memset(state, 0, sizeof(*state));
 964         state->ns.neigh_sub_iter = clip_seq_sub_iter;
 965
 966         rc = seq_open(file, &arp_seq_ops);
 967         if (rc)
 968                 goto out_kfree;
 969
 970         seq = file->private_data;
 971         seq->private = state;
 972 out:
 973         return rc;
 974
 975 out_kfree:
 976         kfree(state);
 977         goto out;
 978 }
 979
 980 static struct file_operations arp_seq_fops = {
 981         .open           = arp_seq_open,
 982         .read           = seq_read,
 983         .llseek         = seq_lseek,
 984         .release        = seq_release_private,
 985         .owner          = THIS_MODULE
 986 };
 987 #endif
 988
 989 static int __init atm_clip_init(void)
 990 {
 991         neigh_table_init(&clip_tbl);
 992
 993         clip_tbl_hook = &clip_tbl;
 994         register_atm_ioctl(&clip_ioctl_ops);
 995
 996 #ifdef CONFIG_PROC_FS
 997 {
 998         struct proc_dir_entry *p;
 999
1000         p = create_proc_entry("arp", S_IRUGO, atm_proc_root);
1001         if (p)
1002                 p->proc_fops = &arp_seq_fops;
1003 }
1004 #endif
1005
1006         return 0;
1007 }
1008
1009 static void __exit atm_clip_exit(void)
1010 {
1011         struct net_device *dev, *next;
1012
1013         remove_proc_entry("arp", atm_proc_root);
1014
1015         deregister_atm_ioctl(&clip_ioctl_ops);
1016
1017         /* First, stop the idle timer, so it stops banging
1018          * on the table.
1019          */
1020         if (start_timer == 0)
1021                 del_timer(&idle_timer);
1022
1023         /* Next, purge the table, so that the device
1024          * unregister loop below does not hang due to
1025          * device references remaining in the table.
1026          */
1027         neigh_ifdown(&clip_tbl, NULL);
1028
1029         dev = clip_devs;
1030         while (dev) {
1031                 next = PRIV(dev)->next;
1032                 unregister_netdev(dev);
1033                 free_netdev(dev);
1034                 dev = next;
1035         }
1036
1037         /* Now it is safe to fully shutdown whole table. */
1038         neigh_table_clear(&clip_tbl);
1039
1040         clip_tbl_hook = NULL;
1041 }
1042
1043 module_init(atm_clip_init);
1044 module_exit(atm_clip_exit);
1045
1046 MODULE_LICENSE("GPL");