net/atm/clip.c

   1 /* net/atm/clip.c - RFC1577 Classical IP over ATM */
   2
   3 /* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */
   4
   5
   6 #include <linux/config.h>
   7 #include <linux/string.h>
   8 #include <linux/errno.h>
   9 #include <linux/kernel.h> /* for UINT_MAX */
  10 #include <linux/module.h>
  11 #include <linux/init.h>
  12 #include <linux/netdevice.h>
  13 #include <linux/skbuff.h>
  14 #include <linux/wait.h>
  15 #include <linux/timer.h>
  16 #include <linux/if_arp.h> /* for some manifest constants */
  17 #include <linux/notifier.h>
  18 #include <linux/atm.h>
  19 #include <linux/atmdev.h>
  20 #include <linux/atmclip.h>
  21 #include <linux/atmarp.h>
  22 #include <linux/ip.h> /* for net/route.h */
  23 #include <linux/in.h> /* for struct sockaddr_in */
  24 #include <linux/if.h> /* for IFF_UP */
  25 #include <linux/inetdevice.h>
  26 #include <linux/bitops.h>
  27 #include <linux/proc_fs.h>
  28 #include <linux/seq_file.h>
  29 #include <net/route.h> /* for struct rtable and routing */
  30 #include <net/icmp.h> /* icmp_send */
  31 #include <asm/param.h> /* for HZ */
  32 #include <asm/byteorder.h> /* for htons etc. */
  33 #include <asm/system.h> /* save/restore_flags */
  34 #include <asm/uaccess.h>
  35 #include <asm/atomic.h>
  36
  37 #include "common.h"
  38 #include "resources.h"
  39 #include "ipcommon.h"
  40 #include <net/atmclip.h>
  41
  42
  43 #if 0
  44 #define DPRINTK(format,args...) printk(format,##args)
  45 #else
  46 #define DPRINTK(format,args...)
  47 #endif
  48
  49
  50 struct net_device *clip_devs = NULL;
  51 struct atm_vcc *atmarpd = NULL;
  52 static struct neigh_table clip_tbl;
  53 static struct timer_list idle_timer;
  54 static int start_timer = 1;
  55
  56
  57 static int to_atmarpd(enum atmarp_ctrl_type type,int itf,unsigned long ip)
  58 {
  59         struct atmarp_ctrl *ctrl;
  60         struct sk_buff *skb;
  61
  62         DPRINTK("to_atmarpd(%d)\n",type);
  63         if (!atmarpd) return -EUNATCH;
  64         skb = alloc_skb(sizeof(struct atmarp_ctrl),GFP_ATOMIC);
  65         if (!skb) return -ENOMEM;
  66         ctrl = (struct atmarp_ctrl *) skb_put(skb,sizeof(struct atmarp_ctrl));
  67         ctrl->type = type;
  68         ctrl->itf_num = itf;
  69         ctrl->ip = ip;
  70         atm_force_charge(atmarpd,skb->truesize);
  71         skb_queue_tail(&atmarpd->sk->sk_receive_queue, skb);
  72         atmarpd->sk->sk_data_ready(atmarpd->sk, skb->len);
  73         return 0;
  74 }
  75
  76
  77 static void link_vcc(struct clip_vcc *clip_vcc,struct atmarp_entry *entry)
  78 {
  79         DPRINTK("link_vcc %p to entry %p (neigh %p)\n",clip_vcc,entry,
  80             entry->neigh);
  81         clip_vcc->entry = entry;
  82         clip_vcc->xoff = 0; /* @@@ may overrun buffer by one packet */
  83         clip_vcc->next = entry->vccs;
  84         entry->vccs = clip_vcc;
  85         entry->neigh->used = jiffies;
  86 }
  87
  88
  89 static void unlink_clip_vcc(struct clip_vcc *clip_vcc)
  90 {
  91         struct atmarp_entry *entry = clip_vcc->entry;
  92         struct clip_vcc **walk;
  93
  94         if (!entry) {
  95                 printk(KERN_CRIT "!clip_vcc->entry (clip_vcc %p)\n",clip_vcc);
  96                 return;
  97         }
  98         spin_lock_bh(&entry->neigh->dev->xmit_lock);    /* block clip_start_xmit() */
  99         entry->neigh->used = jiffies;
 100         for (walk = &entry->vccs; *walk; walk = &(*walk)->next)
 101                 if (*walk == clip_vcc) {
 102                         int error;
 103
 104                         *walk = clip_vcc->next; /* atomic */
 105                         clip_vcc->entry = NULL;
 106                         if (clip_vcc->xoff)
 107                                 netif_wake_queue(entry->neigh->dev);
 108                         if (entry->vccs)
 109                                 goto out;
 110                         entry->expires = jiffies-1;
 111                                 /* force resolution or expiration */
 112                         error = neigh_update(entry->neigh,NULL,NUD_NONE,0,0);
 113                         if (error)
 114                                 printk(KERN_CRIT "unlink_clip_vcc: "
 115                                     "neigh_update failed with %d\n",error);
 116                         goto out;
 117                 }
 118         printk(KERN_CRIT "ATMARP: unlink_clip_vcc failed (entry %p, vcc "
 119           "0x%p)\n",entry,clip_vcc);
 120 out:
 121         spin_unlock_bh(&entry->neigh->dev->xmit_lock);
 122 }
 123
 124
 125 static void idle_timer_check(unsigned long dummy)
 126 {
 127         int i;
 128
 129         /*DPRINTK("idle_timer_check\n");*/
 130         write_lock(&clip_tbl.lock);
 131         for (i = 0; i <= NEIGH_HASHMASK; i++) {
 132                 struct neighbour **np;
 133
 134                 for (np = &clip_tbl.hash_buckets[i]; *np;) {
 135                         struct neighbour *n = *np;
 136                         struct atmarp_entry *entry = NEIGH2ENTRY(n);
 137                         struct clip_vcc *clip_vcc;
 138
 139                         write_lock(&n->lock);
 140
 141                         for (clip_vcc = entry->vccs; clip_vcc;
 142                             clip_vcc = clip_vcc->next)
 143                                 if (clip_vcc->idle_timeout &&
 144                                     time_after(jiffies, clip_vcc->last_use+
 145                                     clip_vcc->idle_timeout)) {
 146                                         DPRINTK("releasing vcc %p->%p of "
 147                                             "entry %p\n",clip_vcc,clip_vcc->vcc,
 148                                             entry);
 149                                         vcc_release_async(clip_vcc->vcc,
 150                                                           -ETIMEDOUT);
 151                                 }
 152                         if (entry->vccs ||
 153                             time_before(jiffies, entry->expires)) {
 154                                 np = &n->next;
 155                                 write_unlock(&n->lock);
 156                                 continue;
 157                         }
 158                         if (atomic_read(&n->refcnt) > 1) {
 159                                 struct sk_buff *skb;
 160
 161                                 DPRINTK("destruction postponed with ref %d\n",
 162                                     atomic_read(&n->refcnt));
 163                                 while ((skb = skb_dequeue(&n->arp_queue)) !=
 164                                      NULL)
 165                                         dev_kfree_skb(skb);
 166                                 np = &n->next;
 167                                 write_unlock(&n->lock);
 168                                 continue;
 169                         }
 170                         *np = n->next;
 171                         DPRINTK("expired neigh %p\n",n);
 172                         n->dead = 1;
 173                         write_unlock(&n->lock);
 174                         neigh_release(n);
 175                 }
 176         }
 177         mod_timer(&idle_timer, jiffies+CLIP_CHECK_INTERVAL*HZ);
 178         write_unlock(&clip_tbl.lock);
 179 }
 180
 181
 182 static int clip_arp_rcv(struct sk_buff *skb)
 183 {
 184         struct atm_vcc *vcc;
 185
 186         DPRINTK("clip_arp_rcv\n");
 187         vcc = ATM_SKB(skb)->vcc;
 188         if (!vcc || !atm_charge(vcc,skb->truesize)) {
 189                 dev_kfree_skb_any(skb);
 190                 return 0;
 191         }
 192         DPRINTK("pushing to %p\n",vcc);
 193         DPRINTK("using %p\n",CLIP_VCC(vcc)->old_push);
 194         CLIP_VCC(vcc)->old_push(vcc,skb);
 195         return 0;
 196 }
 197
 198 static const unsigned char llc_oui[] = {
 199         0xaa,   /* DSAP: non-ISO */
 200         0xaa,   /* SSAP: non-ISO */
 201         0x03,   /* Ctrl: Unnumbered Information Command PDU */
 202         0x00,   /* OUI: EtherType */
 203         0x00,
 204         0x00 };
 205
 206 static void clip_push(struct atm_vcc *vcc,struct sk_buff *skb)
 207 {
 208         struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
 209
 210         DPRINTK("clip push\n");
 211         if (!skb) {
 212                 DPRINTK("removing VCC %p\n",clip_vcc);
 213                 if (clip_vcc->entry) unlink_clip_vcc(clip_vcc);
 214                 clip_vcc->old_push(vcc,NULL); /* pass on the bad news */
 215                 kfree(clip_vcc);
 216                 return;
 217         }
 218         atm_return(vcc,skb->truesize);
 219         skb->dev = clip_vcc->entry ? clip_vcc->entry->neigh->dev : clip_devs;
 220                 /* clip_vcc->entry == NULL if we don't have an IP address yet */
 221         if (!skb->dev) {
 222                 dev_kfree_skb_any(skb);
 223                 return;
 224         }
 225         ATM_SKB(skb)->vcc = vcc;
 226         skb->mac.raw = skb->data;
 227         if (!clip_vcc->encap || skb->len < RFC1483LLC_LEN || memcmp(skb->data,
 228             llc_oui,sizeof(llc_oui))) skb->protocol = htons(ETH_P_IP);
 229         else {
 230                 skb->protocol = ((u16 *) skb->data)[3];
 231                 skb_pull(skb,RFC1483LLC_LEN);
 232                 if (skb->protocol == htons(ETH_P_ARP)) {
 233                         PRIV(skb->dev)->stats.rx_packets++;
 234                         PRIV(skb->dev)->stats.rx_bytes += skb->len;
 235                         clip_arp_rcv(skb);
 236                         return;
 237                 }
 238         }
 239         clip_vcc->last_use = jiffies;
 240         PRIV(skb->dev)->stats.rx_packets++;
 241         PRIV(skb->dev)->stats.rx_bytes += skb->len;
 242         memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
 243         netif_rx(skb);
 244 }
 245
 246
 247 /*
 248  * Note: these spinlocks _must_not_ block on non-SMP. The only goal is that
 249  * clip_pop is atomic with respect to the critical section in clip_start_xmit.
 250  */
 251
 252
 253 static void clip_pop(struct atm_vcc *vcc,struct sk_buff *skb)
 254 {
 255         struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
 256         struct net_device *dev = skb->dev;
 257         int old;
 258         unsigned long flags;
 259
 260         DPRINTK("clip_pop(vcc %p)\n",vcc);
 261         clip_vcc->old_pop(vcc,skb);
 262         /* skb->dev == NULL in outbound ARP packets */
 263         if (!dev) return;
 264         spin_lock_irqsave(&PRIV(dev)->xoff_lock,flags);
 265         if (atm_may_send(vcc,0)) {
 266                 old = xchg(&clip_vcc->xoff,0);
 267                 if (old) netif_wake_queue(dev);
 268         }
 269         spin_unlock_irqrestore(&PRIV(dev)->xoff_lock,flags);
 270 }
 271
 272
 273 static void clip_neigh_destroy(struct neighbour *neigh)
 274 {
 275         DPRINTK("clip_neigh_destroy (neigh %p)\n",neigh);
 276         if (NEIGH2ENTRY(neigh)->vccs)
 277                 printk(KERN_CRIT "clip_neigh_destroy: vccs != NULL !!!\n");
 278         NEIGH2ENTRY(neigh)->vccs = (void *) 0xdeadbeef;
 279 }
 280
 281
 282 static void clip_neigh_solicit(struct neighbour *neigh,struct sk_buff *skb)
 283 {
 284         DPRINTK("clip_neigh_solicit (neigh %p, skb %p)\n",neigh,skb);
 285         to_atmarpd(act_need,PRIV(neigh->dev)->number,NEIGH2ENTRY(neigh)->ip);
 286 }
 287
 288
 289 static void clip_neigh_error(struct neighbour *neigh,struct sk_buff *skb)
 290 {
 291 #ifndef CONFIG_ATM_CLIP_NO_ICMP
 292         icmp_send(skb,ICMP_DEST_UNREACH,ICMP_HOST_UNREACH,0);
 293 #endif
 294         kfree_skb(skb);
 295 }
 296
 297
 298 static struct neigh_ops clip_neigh_ops = {
 299         .family =               AF_INET,
 300         .destructor =           clip_neigh_destroy,
 301         .solicit =              clip_neigh_solicit,
 302         .error_report =         clip_neigh_error,
 303         .output =               dev_queue_xmit,
 304         .connected_output =     dev_queue_xmit,
 305         .hh_output =            dev_queue_xmit,
 306         .queue_xmit =           dev_queue_xmit,
 307 };
 308
 309
 310 static int clip_constructor(struct neighbour *neigh)
 311 {
 312         struct atmarp_entry *entry = NEIGH2ENTRY(neigh);
 313         struct net_device *dev = neigh->dev;
 314         struct in_device *in_dev = dev->ip_ptr;
 315
 316         DPRINTK("clip_constructor (neigh %p, entry %p)\n",neigh,entry);
 317         if (!in_dev) return -EINVAL;
 318         neigh->type = inet_addr_type(entry->ip);
 319         if (neigh->type != RTN_UNICAST) return -EINVAL;
 320         if (in_dev->arp_parms) neigh->parms = in_dev->arp_parms;
 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         u32 hash_val;
 333
 334         hash_val = *(u32*)pkey;
 335         hash_val ^= (hash_val>>16);
 336         hash_val ^= hash_val>>8;
 337         hash_val ^= hash_val>>3;
 338         hash_val = (hash_val^dev->ifindex)&NEIGH_HASHMASK;
 339
 340         return hash_val;
 341 }
 342
 343 static struct neigh_table clip_tbl = {
 344         .family         = AF_INET,
 345         .entry_size     = sizeof(struct neighbour)+sizeof(struct atmarp_entry),
 346         .key_len        = 4,
 347         .hash           = clip_hash,
 348         .constructor    = clip_constructor,
 349         .id             = "clip_arp_cache",
 350
 351         /* parameters are copied from ARP ... */
 352         .parms = {
 353                 .tbl                    = &clip_tbl,
 354                 .base_reachable_time    = 30 * HZ,
 355                 .retrans_time           = 1 * HZ,
 356                 .gc_staletime           = 60 * HZ,
 357                 .reachable_time         = 30 * HZ,
 358                 .delay_probe_time       = 5 * HZ,
 359                 .queue_len              = 3,
 360                 .ucast_probes           = 3,
 361                 .mcast_probes           = 3,
 362                 .anycast_delay          = 1 * HZ,
 363                 .proxy_delay            = (8 * HZ) / 10,
 364                 .proxy_qlen             = 64,
 365                 .locktime               = 1 * HZ,
 366         },
 367         .gc_interval    = 30 * HZ,
 368         .gc_thresh1     = 128,
 369         .gc_thresh2     = 512,
 370         .gc_thresh3     = 1024,
 371 };
 372
 373
 374 /* @@@ copy bh locking from arp.c -- need to bh-enable atm code before */
 375
 376 /*
 377  * We play with the resolve flag: 0 and 1 have the usual meaning, but -1 means
 378  * to allocate the neighbour entry but not to ask atmarpd for resolution. Also,
 379  * don't increment the usage count. This is used to create entries in
 380  * clip_setentry.
 381  */
 382
 383
 384 static int clip_encap(struct atm_vcc *vcc,int mode)
 385 {
 386         CLIP_VCC(vcc)->encap = mode;
 387         return 0;
 388 }
 389
 390
 391 static int clip_start_xmit(struct sk_buff *skb,struct net_device *dev)
 392 {
 393         struct clip_priv *clip_priv = PRIV(dev);
 394         struct atmarp_entry *entry;
 395         struct atm_vcc *vcc;
 396         int old;
 397         unsigned long flags;
 398
 399         DPRINTK("clip_start_xmit (skb %p)\n",skb);
 400         if (!skb->dst) {
 401                 printk(KERN_ERR "clip_start_xmit: skb->dst == NULL\n");
 402                 dev_kfree_skb(skb);
 403                 clip_priv->stats.tx_dropped++;
 404                 return 0;
 405         }
 406         if (!skb->dst->neighbour) {
 407 #if 0
 408                 skb->dst->neighbour = clip_find_neighbour(skb->dst,1);
 409                 if (!skb->dst->neighbour) {
 410                         dev_kfree_skb(skb); /* lost that one */
 411                         clip_priv->stats.tx_dropped++;
 412                         return 0;
 413                 }
 414 #endif
 415                 printk(KERN_ERR "clip_start_xmit: NO NEIGHBOUR !\n");
 416                 dev_kfree_skb(skb);
 417                 clip_priv->stats.tx_dropped++;
 418                 return 0;
 419         }
 420         entry = NEIGH2ENTRY(skb->dst->neighbour);
 421         if (!entry->vccs) {
 422                 if (time_after(jiffies, entry->expires)) {
 423                         /* should be resolved */
 424                         entry->expires = jiffies+ATMARP_RETRY_DELAY*HZ;
 425                         to_atmarpd(act_need,PRIV(dev)->number,entry->ip);
 426                 }
 427                 if (entry->neigh->arp_queue.qlen < ATMARP_MAX_UNRES_PACKETS)
 428                         skb_queue_tail(&entry->neigh->arp_queue,skb);
 429                 else {
 430                         dev_kfree_skb(skb);
 431                         clip_priv->stats.tx_dropped++;
 432                 }
 433                 return 0;
 434         }
 435         DPRINTK("neigh %p, vccs %p\n",entry,entry->vccs);
 436         ATM_SKB(skb)->vcc = vcc = entry->vccs->vcc;
 437         DPRINTK("using neighbour %p, vcc %p\n",skb->dst->neighbour,vcc);
 438         if (entry->vccs->encap) {
 439                 void *here;
 440
 441                 here = skb_push(skb,RFC1483LLC_LEN);
 442                 memcpy(here,llc_oui,sizeof(llc_oui));
 443                 ((u16 *) here)[3] = skb->protocol;
 444         }
 445         atomic_add(skb->truesize, &vcc->sk->sk_wmem_alloc);
 446         ATM_SKB(skb)->atm_options = vcc->atm_options;
 447         entry->vccs->last_use = jiffies;
 448         DPRINTK("atm_skb(%p)->vcc(%p)->dev(%p)\n",skb,vcc,vcc->dev);
 449         old = xchg(&entry->vccs->xoff,1); /* assume XOFF ... */
 450         if (old) {
 451                 printk(KERN_WARNING "clip_start_xmit: XOFF->XOFF transition\n");
 452                 return 0;
 453         }
 454         clip_priv->stats.tx_packets++;
 455         clip_priv->stats.tx_bytes += skb->len;
 456         (void) vcc->send(vcc,skb);
 457         if (atm_may_send(vcc,0)) {
 458                 entry->vccs->xoff = 0;
 459                 return 0;
 460         }
 461         spin_lock_irqsave(&clip_priv->xoff_lock,flags);
 462         netif_stop_queue(dev); /* XOFF -> throttle immediately */
 463         barrier();
 464         if (!entry->vccs->xoff)
 465                 netif_start_queue(dev);
 466                 /* Oh, we just raced with clip_pop. netif_start_queue should be
 467                    good enough, because nothing should really be asleep because
 468                    of the brief netif_stop_queue. If this isn't true or if it
 469                    changes, use netif_wake_queue instead. */
 470         spin_unlock_irqrestore(&clip_priv->xoff_lock,flags);
 471         return 0;
 472 }
 473
 474
 475 static struct net_device_stats *clip_get_stats(struct net_device *dev)
 476 {
 477         return &PRIV(dev)->stats;
 478 }
 479
 480
 481 static int clip_mkip(struct atm_vcc *vcc,int timeout)
 482 {
 483         struct clip_vcc *clip_vcc;
 484         struct sk_buff_head copy;
 485         struct sk_buff *skb;
 486
 487         if (!vcc->push) return -EBADFD;
 488         clip_vcc = kmalloc(sizeof(struct clip_vcc),GFP_KERNEL);
 489         if (!clip_vcc) return -ENOMEM;
 490         DPRINTK("mkip clip_vcc %p vcc %p\n",clip_vcc,vcc);
 491         clip_vcc->vcc = vcc;
 492         vcc->user_back = clip_vcc;
 493         set_bit(ATM_VF_IS_CLIP, &vcc->flags);
 494         clip_vcc->entry = NULL;
 495         clip_vcc->xoff = 0;
 496         clip_vcc->encap = 1;
 497         clip_vcc->last_use = jiffies;
 498         clip_vcc->idle_timeout = timeout*HZ;
 499         clip_vcc->old_push = vcc->push;
 500         clip_vcc->old_pop = vcc->pop;
 501         vcc->push = clip_push;
 502         vcc->pop = clip_pop;
 503         skb_queue_head_init(&copy);
 504         skb_migrate(&vcc->sk->sk_receive_queue, &copy);
 505         /* re-process everything received between connection setup and MKIP */
 506         while ((skb = skb_dequeue(&copy)))
 507                 if (!clip_devs) {
 508                         atm_return(vcc,skb->truesize);
 509                         kfree_skb(skb);
 510                 }
 511                 else {
 512                         unsigned int len = skb->len;
 513
 514                         clip_push(vcc,skb);
 515                         PRIV(skb->dev)->stats.rx_packets--;
 516                         PRIV(skb->dev)->stats.rx_bytes -= len;
 517                 }
 518         return 0;
 519 }
 520
 521
 522 static int clip_setentry(struct atm_vcc *vcc,u32 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) return error;
 547         neigh = __neigh_lookup(&clip_tbl,&ip,rt->u.dst.dev,1);
 548         ip_rt_put(rt);
 549         if (!neigh)
 550                 return -ENOMEM;
 551         entry = NEIGH2ENTRY(neigh);
 552         if (entry != clip_vcc->entry) {
 553                 if (!clip_vcc->entry) DPRINTK("setentry: add\n");
 554                 else {
 555                         DPRINTK("setentry: update\n");
 556                         unlink_clip_vcc(clip_vcc);
 557                 }
 558                 link_vcc(clip_vcc,entry);
 559         }
 560         error = neigh_update(neigh,llc_oui,NUD_PERMANENT,1,0);
 561         neigh_release(neigh);
 562         return error;
 563 }
 564
 565
 566 static void clip_setup(struct net_device *dev)
 567 {
 568         dev->hard_start_xmit = clip_start_xmit;
 569         /* sg_xmit ... */
 570         dev->get_stats = clip_get_stats;
 571         dev->type = ARPHRD_ATM;
 572         dev->hard_header_len = RFC1483LLC_LEN;
 573         dev->mtu = RFC1626_MTU;
 574         dev->tx_queue_len = 100; /* "normal" queue (packets) */
 575             /* When using a "real" qdisc, the qdisc determines the queue */
 576             /* length. tx_queue_len is only used for the default case, */
 577             /* without any more elaborate queuing. 100 is a reasonable */
 578             /* compromise between decent burst-tolerance and protection */
 579             /* against memory hogs. */
 580 }
 581
 582
 583 static int clip_create(int number)
 584 {
 585         struct net_device *dev;
 586         struct clip_priv *clip_priv;
 587         int error;
 588
 589         if (number != -1) {
 590                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
 591                         if (PRIV(dev)->number == number) return -EEXIST;
 592         }
 593         else {
 594                 number = 0;
 595                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
 596                         if (PRIV(dev)->number >= number)
 597                                 number = PRIV(dev)->number+1;
 598         }
 599         dev = alloc_netdev(sizeof(struct clip_priv), "", clip_setup);
 600         if (!dev)
 601                 return -ENOMEM;
 602         clip_priv = PRIV(dev);
 603         sprintf(dev->name,"atm%d",number);
 604         spin_lock_init(&clip_priv->xoff_lock);
 605         clip_priv->number = number;
 606         error = register_netdev(dev);
 607         if (error) {
 608                 free_netdev(dev);
 609                 return error;
 610         }
 611         clip_priv->next = clip_devs;
 612         clip_devs = dev;
 613         DPRINTK("registered (net:%s)\n",dev->name);
 614         return number;
 615 }
 616
 617
 618 static int clip_device_event(struct notifier_block *this,unsigned long event,
 619     void *dev)
 620 {
 621         /* ignore non-CLIP devices */
 622         if (((struct net_device *) dev)->type != ARPHRD_ATM ||
 623             ((struct net_device *) dev)->hard_start_xmit != clip_start_xmit)
 624                 return NOTIFY_DONE;
 625         switch (event) {
 626                 case NETDEV_UP:
 627                         DPRINTK("clip_device_event NETDEV_UP\n");
 628                         (void) to_atmarpd(act_up,PRIV(dev)->number,0);
 629                         break;
 630                 case NETDEV_GOING_DOWN:
 631                         DPRINTK("clip_device_event NETDEV_DOWN\n");
 632                         (void) to_atmarpd(act_down,PRIV(dev)->number,0);
 633                         break;
 634                 case NETDEV_CHANGE:
 635                 case NETDEV_CHANGEMTU:
 636                         DPRINTK("clip_device_event NETDEV_CHANGE*\n");
 637                         (void) to_atmarpd(act_change,PRIV(dev)->number,0);
 638                         break;
 639                 case NETDEV_REBOOT:
 640                 case NETDEV_REGISTER:
 641                 case NETDEV_DOWN:
 642                         DPRINTK("clip_device_event %ld\n",event);
 643                         /* ignore */
 644                         break;
 645                 default:
 646                         printk(KERN_WARNING "clip_device_event: unknown event "
 647                             "%ld\n",event);
 648                         break;
 649         }
 650         return NOTIFY_DONE;
 651 }
 652
 653
 654 static int clip_inet_event(struct notifier_block *this,unsigned long event,
 655     void *ifa)
 656 {
 657         struct in_device *in_dev;
 658
 659         in_dev = ((struct in_ifaddr *) ifa)->ifa_dev;
 660         if (!in_dev || !in_dev->dev) {
 661                 printk(KERN_WARNING "clip_inet_event: no device\n");
 662                 return NOTIFY_DONE;
 663         }
 664         /*
 665          * Transitions are of the down-change-up type, so it's sufficient to
 666          * handle the change on up.
 667          */
 668         if (event != NETDEV_UP) return NOTIFY_DONE;
 669         return clip_device_event(this,NETDEV_CHANGE,in_dev->dev);
 670 }
 671
 672
 673 static struct notifier_block clip_dev_notifier = {
 674         clip_device_event,
 675         NULL,
 676         0
 677 };
 678
 679
 680
 681 static struct notifier_block clip_inet_notifier = {
 682         clip_inet_event,
 683         NULL,
 684         0
 685 };
 686
 687
 688
 689 static void atmarpd_close(struct atm_vcc *vcc)
 690 {
 691         DPRINTK("atmarpd_close\n");
 692         atmarpd = NULL; /* assumed to be atomic */
 693         barrier();
 694         unregister_inetaddr_notifier(&clip_inet_notifier);
 695         unregister_netdevice_notifier(&clip_dev_notifier);
 696         if (skb_peek(&vcc->sk->sk_receive_queue))
 697                 printk(KERN_ERR "atmarpd_close: closing with requests "
 698                     "pending\n");
 699         skb_queue_purge(&vcc->sk->sk_receive_queue);
 700         DPRINTK("(done)\n");
 701         module_put(THIS_MODULE);
 702 }
 703
 704
 705 static struct atmdev_ops atmarpd_dev_ops = {
 706         .close = atmarpd_close
 707 };
 708
 709
 710 static struct atm_dev atmarpd_dev = {
 711         .ops =                  &atmarpd_dev_ops,
 712         .type =                 "arpd",
 713         .number =               999,
 714         .lock =                 SPIN_LOCK_UNLOCKED
 715 };
 716
 717
 718 static int atm_init_atmarp(struct atm_vcc *vcc)
 719 {
 720         if (atmarpd) return -EADDRINUSE;
 721         if (start_timer) {
 722                 start_timer = 0;
 723                 init_timer(&idle_timer);
 724                 idle_timer.expires = jiffies+CLIP_CHECK_INTERVAL*HZ;
 725                 idle_timer.function = idle_timer_check;
 726                 add_timer(&idle_timer);
 727         }
 728         atmarpd = vcc;
 729         set_bit(ATM_VF_META,&vcc->flags);
 730         set_bit(ATM_VF_READY,&vcc->flags);
 731             /* allow replies and avoid getting closed if signaling dies */
 732         vcc->dev = &atmarpd_dev;
 733         vcc_insert_socket(vcc->sk);
 734         vcc->push = NULL;
 735         vcc->pop = NULL; /* crash */
 736         vcc->push_oam = NULL; /* crash */
 737         if (register_netdevice_notifier(&clip_dev_notifier))
 738                 printk(KERN_ERR "register_netdevice_notifier failed\n");
 739         if (register_inetaddr_notifier(&clip_inet_notifier))
 740                 printk(KERN_ERR "register_inetaddr_notifier failed\n");
 741         return 0;
 742 }
 743
 744 static int clip_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 745 {
 746         struct atm_vcc *vcc = ATM_SD(sock);
 747         int err = 0;
 748
 749         switch (cmd) {
 750                 case SIOCMKCLIP:
 751                 case ATMARPD_CTRL:
 752                 case ATMARP_MKIP:
 753                 case ATMARP_SETENTRY:
 754                 case ATMARP_ENCAP:
 755                         if (!capable(CAP_NET_ADMIN))
 756                                 return -EPERM;
 757                         break;
 758                 default:
 759                         return -ENOIOCTLCMD;
 760         }
 761
 762         switch (cmd) {
 763                 case SIOCMKCLIP:
 764                         err = clip_create(arg);
 765                         break;
 766                 case ATMARPD_CTRL:
 767                         err = atm_init_atmarp(vcc);
 768                         if (!err) {
 769                                 sock->state = SS_CONNECTED;
 770                                 __module_get(THIS_MODULE);
 771                         }
 772                         break;
 773                 case ATMARP_MKIP:
 774                         err = clip_mkip(vcc ,arg);
 775                         break;
 776                 case ATMARP_SETENTRY:
 777                         err = clip_setentry(vcc, arg);
 778                         break;
 779                 case ATMARP_ENCAP:
 780                         err = clip_encap(vcc, arg);
 781                         break;
 782         }
 783         return err;
 784 }
 785
 786 static struct atm_ioctl clip_ioctl_ops = {
 787         .owner  = THIS_MODULE,
 788         .ioctl  = clip_ioctl,
 789 };
 790
 791 #ifdef CONFIG_PROC_FS
 792
 793 static void svc_addr(struct seq_file *seq, struct sockaddr_atmsvc *addr)
 794 {
 795         static int code[] = { 1,2,10,6,1,0 };
 796         static int e164[] = { 1,8,4,6,1,0 };
 797
 798         if (*addr->sas_addr.pub) {
 799                 seq_printf(seq, "%s", addr->sas_addr.pub);
 800                 if (*addr->sas_addr.prv)
 801                         seq_putc(seq, '+');
 802         } else if (!*addr->sas_addr.prv) {
 803                 seq_printf(seq, "%s", "(none)");
 804                 return;
 805         }
 806         if (*addr->sas_addr.prv) {
 807                 unsigned char *prv = addr->sas_addr.prv;
 808                 int *fields;
 809                 int i, j;
 810
 811                 fields = *prv == ATM_AFI_E164 ? e164 : code;
 812                 for (i = 0; fields[i]; i++) {
 813                         for (j = fields[i]; j; j--)
 814                                 seq_printf(seq, "%02X", *prv++);
 815                         if (fields[i+1])
 816                                 seq_putc(seq, '.');
 817                 }
 818         }
 819 }
 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         char buf[17];
 825         int svc, off;
 826
 827         svc = !clip_vcc || clip_vcc->vcc->sk->sk_family == AF_ATMSVC;
 828         seq_printf(seq, "%-6s%-4s%-4s%5ld ", dev->name, svc ? "SVC" : "PVC",
 829             !clip_vcc || clip_vcc->encap ? "LLC" : "NULL",
 830             (jiffies-(clip_vcc ? clip_vcc->last_use : entry->neigh->used))/HZ);
 831
 832         off = scnprintf(buf, sizeof(buf) - 1, "%d.%d.%d.%d", NIPQUAD(entry->ip));
 833         while (off < 16)
 834                 buf[off++] = ' ';
 835         buf[off] = '\0';
 836         seq_printf(seq, "%s", buf);
 837
 838         if (!clip_vcc) {
 839                 if (time_before(jiffies, entry->expires))
 840                         seq_printf(seq, "(resolving)\n");
 841                 else
 842                         seq_printf(seq, "(expired, ref %d)\n",
 843                                    atomic_read(&entry->neigh->refcnt));
 844         } else if (!svc) {
 845                 seq_printf(seq, "%d.%d.%d\n", clip_vcc->vcc->dev->number,
 846                            clip_vcc->vcc->vpi, clip_vcc->vcc->vci);
 847         } else {
 848                 svc_addr(seq, &clip_vcc->vcc->remote);
 849                 seq_putc(seq, '\n');
 850         }
 851 }
 852
 853 struct arp_state {
 854         int bucket;
 855         struct neighbour *n;
 856         struct clip_vcc *vcc;
 857 };
 858
 859 static void *arp_vcc_walk(struct arp_state *state,
 860                           struct atmarp_entry *e, loff_t *l)
 861 {
 862         struct clip_vcc *vcc = state->vcc;
 863
 864         if (!vcc)
 865                 vcc = e->vccs;
 866         if (vcc == (void *)1) {
 867                 vcc = e->vccs;
 868                 --*l;
 869         }
 870         for (; vcc; vcc = vcc->next) {
 871                 if (--*l < 0)
 872                         break;
 873         }
 874         state->vcc = vcc;
 875         return (*l < 0) ? state : NULL;
 876 }
 877
 878 static void *arp_get_idx(struct arp_state *state, loff_t l)
 879 {
 880         void *v = NULL;
 881
 882         for (; state->bucket <= NEIGH_HASHMASK; state->bucket++) {
 883                 for (; state->n; state->n = state->n->next) {
 884                         v = arp_vcc_walk(state, NEIGH2ENTRY(state->n), &l);
 885                         if (v)
 886                                 goto done;
 887                 }
 888                 state->n = clip_tbl.hash_buckets[state->bucket + 1];
 889         }
 890 done:
 891         return v;
 892 }
 893
 894 static void *arp_seq_start(struct seq_file *seq, loff_t *pos)
 895 {
 896         struct arp_state *state = seq->private;
 897         void *ret = (void *)1;
 898
 899         read_lock_bh(&clip_tbl.lock);
 900         state->bucket = 0;
 901         state->n = clip_tbl.hash_buckets[0];
 902         state->vcc = (void *)1;
 903         if (*pos)
 904                 ret = arp_get_idx(state, *pos);
 905         return ret;
 906 }
 907
 908 static void arp_seq_stop(struct seq_file *seq, void *v)
 909 {
 910         struct arp_state *state = seq->private;
 911
 912         if (state->bucket != -1)
 913                 read_unlock_bh(&clip_tbl.lock);
 914 }
 915
 916 static void *arp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 917 {
 918         struct arp_state *state = seq->private;
 919
 920         v = arp_get_idx(state, 1);
 921         *pos += !!PTR_ERR(v);
 922         return v;
 923 }
 924
 925 static int arp_seq_show(struct seq_file *seq, void *v)
 926 {
 927         static char atm_arp_banner[] =
 928                 "IPitf TypeEncp Idle IP address      ATM address\n";
 929
 930         if (v == (void *)1)
 931                 seq_puts(seq, atm_arp_banner);
 932         else {
 933                 struct arp_state *state = seq->private;
 934                 struct neighbour *n = state->n;
 935                 struct clip_vcc *vcc = state->vcc;
 936
 937                 atmarp_info(seq, n->dev, NEIGH2ENTRY(n), vcc);
 938         }
 939         return 0;
 940 }
 941
 942 static struct seq_operations arp_seq_ops = {
 943         .start  = arp_seq_start,
 944         .next   = arp_seq_next,
 945         .stop   = arp_seq_stop,
 946         .show   = arp_seq_show,
 947 };
 948
 949 static int arp_seq_open(struct inode *inode, struct file *file)
 950 {
 951         struct arp_state *state;
 952         struct seq_file *seq;
 953         int rc = -EAGAIN;
 954
 955         state = kmalloc(sizeof(*state), GFP_KERNEL);
 956         if (!state) {
 957                 rc = -ENOMEM;
 958                 goto out_kfree;
 959         }
 960
 961         rc = seq_open(file, &arp_seq_ops);
 962         if (rc)
 963                 goto out_kfree;
 964
 965         seq = file->private_data;
 966         seq->private = state;
 967 out:
 968         return rc;
 969
 970 out_kfree:
 971         kfree(state);
 972         goto out;
 973 }
 974
 975 static int arp_seq_release(struct inode *inode, struct file *file)
 976 {
 977         return seq_release_private(inode, file);
 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        = arp_seq_release,
 985         .owner          = THIS_MODULE
 986 };
 987 #endif
 988
 989 static int __init atm_clip_init(void)
 990 {
 991         /* we should use neigh_table_init() */
 992         clip_tbl.lock = RW_LOCK_UNLOCKED;
 993         clip_tbl.kmem_cachep = kmem_cache_create(clip_tbl.id,
 994             clip_tbl.entry_size, 0, SLAB_HWCACHE_ALIGN, NULL, NULL);
 995
 996         if (!clip_tbl.kmem_cachep)
 997                 return -ENOMEM;
 998
 999         /* so neigh_ifdown() doesn't complain */
1000         clip_tbl.proxy_timer.data = 0;
1001         clip_tbl.proxy_timer.function = 0;
1002         init_timer(&clip_tbl.proxy_timer);
1003         skb_queue_head_init(&clip_tbl.proxy_queue);
1004
1005         clip_tbl_hook = &clip_tbl;
1006         register_atm_ioctl(&clip_ioctl_ops);
1007
1008 #ifdef CONFIG_PROC_FS
1009 {
1010         struct proc_dir_entry *p;
1011
1012         p = create_proc_entry("arp", S_IRUGO, atm_proc_root);
1013         if (p)
1014                 p->proc_fops = &arp_seq_fops;
1015 }
1016 #endif
1017
1018         return 0;
1019 }
1020
1021 static void __exit atm_clip_exit(void)
1022 {
1023         struct net_device *dev, *next;
1024
1025         remove_proc_entry("arp", atm_proc_root);
1026
1027         deregister_atm_ioctl(&clip_ioctl_ops);
1028
1029         neigh_ifdown(&clip_tbl, NULL);
1030         dev = clip_devs;
1031         while (dev) {
1032                 next = PRIV(dev)->next;
1033                 unregister_netdev(dev);
1034                 free_netdev(dev);
1035                 dev = next;
1036         }
1037         if (start_timer == 0) del_timer(&idle_timer);
1038
1039         kmem_cache_destroy(clip_tbl.kmem_cachep);
1040
1041         clip_tbl_hook = NULL;
1042 }
1043
1044 module_init(atm_clip_init);
1045 module_exit(atm_clip_exit);
1046
1047 MODULE_LICENSE("GPL");