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 #define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
   6
   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/poison.h>
  29 #include <linux/proc_fs.h>
  30 #include <linux/seq_file.h>
  31 #include <linux/rcupdate.h>
  32 #include <linux/jhash.h>
  33 #include <linux/slab.h>
  34 #include <net/route.h> /* for struct rtable and routing */
  35 #include <net/icmp.h> /* icmp_send */
  36 #include <linux/param.h> /* for HZ */
  37 #include <linux/uaccess.h>
  38 #include <asm/byteorder.h> /* for htons etc. */
  39 #include <asm/system.h> /* save/restore_flags */
  40 #include <asm/atomic.h>
  41
  42 #include "common.h"
  43 #include "resources.h"
  44 #include <net/atmclip.h>
  45
  46 static struct net_device *clip_devs;
  47 static struct atm_vcc *atmarpd;
  48 static struct neigh_table clip_tbl;
  49 static struct timer_list idle_timer;
  50
  51 static int to_atmarpd(enum atmarp_ctrl_type type, int itf, __be32 ip)
  52 {
  53         struct sock *sk;
  54         struct atmarp_ctrl *ctrl;
  55         struct sk_buff *skb;
  56
  57         pr_debug("(%d)\n", type);
  58         if (!atmarpd)
  59                 return -EUNATCH;
  60         skb = alloc_skb(sizeof(struct atmarp_ctrl), GFP_ATOMIC);
  61         if (!skb)
  62                 return -ENOMEM;
  63         ctrl = (struct atmarp_ctrl *)skb_put(skb, sizeof(struct atmarp_ctrl));
  64         ctrl->type = type;
  65         ctrl->itf_num = itf;
  66         ctrl->ip = ip;
  67         atm_force_charge(atmarpd, skb->truesize);
  68
  69         sk = sk_atm(atmarpd);
  70         skb_queue_tail(&sk->sk_receive_queue, skb);
  71         sk->sk_data_ready(sk, skb->len);
  72         return 0;
  73 }
  74
  75 static void link_vcc(struct clip_vcc *clip_vcc, struct atmarp_entry *entry)
  76 {
  77         pr_debug("%p to entry %p (neigh %p)\n", clip_vcc, entry, entry->neigh);
  78         clip_vcc->entry = entry;
  79         clip_vcc->xoff = 0;     /* @@@ may overrun buffer by one packet */
  80         clip_vcc->next = entry->vccs;
  81         entry->vccs = clip_vcc;
  82         entry->neigh->used = jiffies;
  83 }
  84
  85 static void unlink_clip_vcc(struct clip_vcc *clip_vcc)
  86 {
  87         struct atmarp_entry *entry = clip_vcc->entry;
  88         struct clip_vcc **walk;
  89
  90         if (!entry) {
  91                 pr_crit("!clip_vcc->entry (clip_vcc %p)\n", clip_vcc);
  92                 return;
  93         }
  94         netif_tx_lock_bh(entry->neigh->dev);    /* block clip_start_xmit() */
  95         entry->neigh->used = jiffies;
  96         for (walk = &entry->vccs; *walk; walk = &(*walk)->next)
  97                 if (*walk == clip_vcc) {
  98                         int error;
  99
 100                         *walk = clip_vcc->next; /* atomic */
 101                         clip_vcc->entry = NULL;
 102                         if (clip_vcc->xoff)
 103                                 netif_wake_queue(entry->neigh->dev);
 104                         if (entry->vccs)
 105                                 goto out;
 106                         entry->expires = jiffies - 1;
 107                         /* force resolution or expiration */
 108                         error = neigh_update(entry->neigh, NULL, NUD_NONE,
 109                                              NEIGH_UPDATE_F_ADMIN);
 110                         if (error)
 111                                 pr_crit("neigh_update failed with %d\n", error);
 112                         goto out;
 113                 }
 114         pr_crit("ATMARP: failed (entry %p, vcc 0x%p)\n", entry, clip_vcc);
 115 out:
 116         netif_tx_unlock_bh(entry->neigh->dev);
 117 }
 118
 119 /* The neighbour entry n->lock is held. */
 120 static int neigh_check_cb(struct neighbour *n)
 121 {
 122         struct atmarp_entry *entry = NEIGH2ENTRY(n);
 123         struct clip_vcc *cv;
 124
 125         for (cv = entry->vccs; cv; cv = cv->next) {
 126                 unsigned long exp = cv->last_use + cv->idle_timeout;
 127
 128                 if (cv->idle_timeout && time_after(jiffies, exp)) {
 129                         pr_debug("releasing vcc %p->%p of entry %p\n",
 130                                  cv, cv->vcc, entry);
 131                         vcc_release_async(cv->vcc, -ETIMEDOUT);
 132                 }
 133         }
 134
 135         if (entry->vccs || time_before(jiffies, entry->expires))
 136                 return 0;
 137
 138         if (atomic_read(&n->refcnt) > 1) {
 139                 struct sk_buff *skb;
 140
 141                 pr_debug("destruction postponed with ref %d\n",
 142                          atomic_read(&n->refcnt));
 143
 144                 while ((skb = skb_dequeue(&n->arp_queue)) != NULL)
 145                         dev_kfree_skb(skb);
 146
 147                 return 0;
 148         }
 149
 150         pr_debug("expired neigh %p\n", n);
 151         return 1;
 152 }
 153
 154 static void idle_timer_check(unsigned long dummy)
 155 {
 156         write_lock(&clip_tbl.lock);
 157         __neigh_for_each_release(&clip_tbl, neigh_check_cb);
 158         mod_timer(&idle_timer, jiffies + CLIP_CHECK_INTERVAL * HZ);
 159         write_unlock(&clip_tbl.lock);
 160 }
 161
 162 static int clip_arp_rcv(struct sk_buff *skb)
 163 {
 164         struct atm_vcc *vcc;
 165
 166         pr_debug("\n");
 167         vcc = ATM_SKB(skb)->vcc;
 168         if (!vcc || !atm_charge(vcc, skb->truesize)) {
 169                 dev_kfree_skb_any(skb);
 170                 return 0;
 171         }
 172         pr_debug("pushing to %p\n", vcc);
 173         pr_debug("using %p\n", CLIP_VCC(vcc)->old_push);
 174         CLIP_VCC(vcc)->old_push(vcc, skb);
 175         return 0;
 176 }
 177
 178 static const unsigned char llc_oui[] = {
 179         0xaa,   /* DSAP: non-ISO */
 180         0xaa,   /* SSAP: non-ISO */
 181         0x03,   /* Ctrl: Unnumbered Information Command PDU */
 182         0x00,   /* OUI: EtherType */
 183         0x00,
 184         0x00
 185 };
 186
 187 static void clip_push(struct atm_vcc *vcc, struct sk_buff *skb)
 188 {
 189         struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
 190
 191         pr_debug("\n");
 192         if (!skb) {
 193                 pr_debug("removing VCC %p\n", clip_vcc);
 194                 if (clip_vcc->entry)
 195                         unlink_clip_vcc(clip_vcc);
 196                 clip_vcc->old_push(vcc, NULL);  /* pass on the bad news */
 197                 kfree(clip_vcc);
 198                 return;
 199         }
 200         atm_return(vcc, skb->truesize);
 201         skb->dev = clip_vcc->entry ? clip_vcc->entry->neigh->dev : clip_devs;
 202         /* clip_vcc->entry == NULL if we don't have an IP address yet */
 203         if (!skb->dev) {
 204                 dev_kfree_skb_any(skb);
 205                 return;
 206         }
 207         ATM_SKB(skb)->vcc = vcc;
 208         skb_reset_mac_header(skb);
 209         if (!clip_vcc->encap ||
 210             skb->len < RFC1483LLC_LEN ||
 211             memcmp(skb->data, llc_oui, sizeof(llc_oui)))
 212                 skb->protocol = htons(ETH_P_IP);
 213         else {
 214                 skb->protocol = ((__be16 *)skb->data)[3];
 215                 skb_pull(skb, RFC1483LLC_LEN);
 216                 if (skb->protocol == htons(ETH_P_ARP)) {
 217                         skb->dev->stats.rx_packets++;
 218                         skb->dev->stats.rx_bytes += skb->len;
 219                         clip_arp_rcv(skb);
 220                         return;
 221                 }
 222         }
 223         clip_vcc->last_use = jiffies;
 224         skb->dev->stats.rx_packets++;
 225         skb->dev->stats.rx_bytes += skb->len;
 226         memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
 227         netif_rx(skb);
 228 }
 229
 230 /*
 231  * Note: these spinlocks _must_not_ block on non-SMP. The only goal is that
 232  * clip_pop is atomic with respect to the critical section in clip_start_xmit.
 233  */
 234
 235 static void clip_pop(struct atm_vcc *vcc, struct sk_buff *skb)
 236 {
 237         struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
 238         struct net_device *dev = skb->dev;
 239         int old;
 240         unsigned long flags;
 241
 242         pr_debug("(vcc %p)\n", vcc);
 243         clip_vcc->old_pop(vcc, skb);
 244         /* skb->dev == NULL in outbound ARP packets */
 245         if (!dev)
 246                 return;
 247         spin_lock_irqsave(&PRIV(dev)->xoff_lock, flags);
 248         if (atm_may_send(vcc, 0)) {
 249                 old = xchg(&clip_vcc->xoff, 0);
 250                 if (old)
 251                         netif_wake_queue(dev);
 252         }
 253         spin_unlock_irqrestore(&PRIV(dev)->xoff_lock, flags);
 254 }
 255
 256 static void clip_neigh_solicit(struct neighbour *neigh, struct sk_buff *skb)
 257 {
 258         pr_debug("(neigh %p, skb %p)\n", neigh, skb);
 259         to_atmarpd(act_need, PRIV(neigh->dev)->number, NEIGH2ENTRY(neigh)->ip);
 260 }
 261
 262 static void clip_neigh_error(struct neighbour *neigh, struct sk_buff *skb)
 263 {
 264 #ifndef CONFIG_ATM_CLIP_NO_ICMP
 265         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
 266 #endif
 267         kfree_skb(skb);
 268 }
 269
 270 static const struct neigh_ops clip_neigh_ops = {
 271         .family =               AF_INET,
 272         .solicit =              clip_neigh_solicit,
 273         .error_report =         clip_neigh_error,
 274         .output =               dev_queue_xmit,
 275         .connected_output =     dev_queue_xmit,
 276         .hh_output =            dev_queue_xmit,
 277         .queue_xmit =           dev_queue_xmit,
 278 };
 279
 280 static int clip_constructor(struct neighbour *neigh)
 281 {
 282         struct atmarp_entry *entry = NEIGH2ENTRY(neigh);
 283         struct net_device *dev = neigh->dev;
 284         struct in_device *in_dev;
 285         struct neigh_parms *parms;
 286
 287         pr_debug("(neigh %p, entry %p)\n", neigh, entry);
 288         neigh->type = inet_addr_type(&init_net, entry->ip);
 289         if (neigh->type != RTN_UNICAST)
 290                 return -EINVAL;
 291
 292         rcu_read_lock();
 293         in_dev = __in_dev_get_rcu(dev);
 294         if (!in_dev) {
 295                 rcu_read_unlock();
 296                 return -EINVAL;
 297         }
 298
 299         parms = in_dev->arp_parms;
 300         __neigh_parms_put(neigh->parms);
 301         neigh->parms = neigh_parms_clone(parms);
 302         rcu_read_unlock();
 303
 304         neigh->ops = &clip_neigh_ops;
 305         neigh->output = neigh->nud_state & NUD_VALID ?
 306             neigh->ops->connected_output : neigh->ops->output;
 307         entry->neigh = neigh;
 308         entry->vccs = NULL;
 309         entry->expires = jiffies - 1;
 310         return 0;
 311 }
 312
 313 static u32 clip_hash(const void *pkey, const struct net_device *dev, __u32 rnd)
 314 {
 315         return jhash_2words(*(u32 *) pkey, dev->ifindex, rnd);
 316 }
 317
 318 static struct neigh_table clip_tbl = {
 319         .family         = AF_INET,
 320         .entry_size     = sizeof(struct neighbour)+sizeof(struct atmarp_entry),
 321         .key_len        = 4,
 322         .hash           = clip_hash,
 323         .constructor    = clip_constructor,
 324         .id             = "clip_arp_cache",
 325
 326         /* parameters are copied from ARP ... */
 327         .parms = {
 328                 .tbl                    = &clip_tbl,
 329                 .base_reachable_time    = 30 * HZ,
 330                 .retrans_time           = 1 * HZ,
 331                 .gc_staletime           = 60 * HZ,
 332                 .reachable_time         = 30 * HZ,
 333                 .delay_probe_time       = 5 * HZ,
 334                 .queue_len              = 3,
 335                 .ucast_probes           = 3,
 336                 .mcast_probes           = 3,
 337                 .anycast_delay          = 1 * HZ,
 338                 .proxy_delay            = (8 * HZ) / 10,
 339                 .proxy_qlen             = 64,
 340                 .locktime               = 1 * HZ,
 341         },
 342         .gc_interval    = 30 * HZ,
 343         .gc_thresh1     = 128,
 344         .gc_thresh2     = 512,
 345         .gc_thresh3     = 1024,
 346 };
 347
 348 /* @@@ copy bh locking from arp.c -- need to bh-enable atm code before */
 349
 350 /*
 351  * We play with the resolve flag: 0 and 1 have the usual meaning, but -1 means
 352  * to allocate the neighbour entry but not to ask atmarpd for resolution. Also,
 353  * don't increment the usage count. This is used to create entries in
 354  * clip_setentry.
 355  */
 356
 357 static int clip_encap(struct atm_vcc *vcc, int mode)
 358 {
 359         CLIP_VCC(vcc)->encap = mode;
 360         return 0;
 361 }
 362
 363 static netdev_tx_t clip_start_xmit(struct sk_buff *skb,
 364                                    struct net_device *dev)
 365 {
 366         struct clip_priv *clip_priv = PRIV(dev);
 367         struct atmarp_entry *entry;
 368         struct atm_vcc *vcc;
 369         int old;
 370         unsigned long flags;
 371
 372         pr_debug("(skb %p)\n", skb);
 373         if (!skb_dst(skb)) {
 374                 pr_err("skb_dst(skb) == NULL\n");
 375                 dev_kfree_skb(skb);
 376                 dev->stats.tx_dropped++;
 377                 return NETDEV_TX_OK;
 378         }
 379         if (!skb_dst(skb)->neighbour) {
 380 #if 0
 381                 skb_dst(skb)->neighbour = clip_find_neighbour(skb_dst(skb), 1);
 382                 if (!skb_dst(skb)->neighbour) {
 383                         dev_kfree_skb(skb);     /* lost that one */
 384                         dev->stats.tx_dropped++;
 385                         return 0;
 386                 }
 387 #endif
 388                 pr_err("NO NEIGHBOUR !\n");
 389                 dev_kfree_skb(skb);
 390                 dev->stats.tx_dropped++;
 391                 return NETDEV_TX_OK;
 392         }
 393         entry = NEIGH2ENTRY(skb_dst(skb)->neighbour);
 394         if (!entry->vccs) {
 395                 if (time_after(jiffies, entry->expires)) {
 396                         /* should be resolved */
 397                         entry->expires = jiffies + ATMARP_RETRY_DELAY * HZ;
 398                         to_atmarpd(act_need, PRIV(dev)->number, entry->ip);
 399                 }
 400                 if (entry->neigh->arp_queue.qlen < ATMARP_MAX_UNRES_PACKETS)
 401                         skb_queue_tail(&entry->neigh->arp_queue, skb);
 402                 else {
 403                         dev_kfree_skb(skb);
 404                         dev->stats.tx_dropped++;
 405                 }
 406                 return NETDEV_TX_OK;
 407         }
 408         pr_debug("neigh %p, vccs %p\n", entry, entry->vccs);
 409         ATM_SKB(skb)->vcc = vcc = entry->vccs->vcc;
 410         pr_debug("using neighbour %p, vcc %p\n", skb_dst(skb)->neighbour, vcc);
 411         if (entry->vccs->encap) {
 412                 void *here;
 413
 414                 here = skb_push(skb, RFC1483LLC_LEN);
 415                 memcpy(here, llc_oui, sizeof(llc_oui));
 416                 ((__be16 *) here)[3] = skb->protocol;
 417         }
 418         atomic_add(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
 419         ATM_SKB(skb)->atm_options = vcc->atm_options;
 420         entry->vccs->last_use = jiffies;
 421         pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, vcc, vcc->dev);
 422         old = xchg(&entry->vccs->xoff, 1);      /* assume XOFF ... */
 423         if (old) {
 424                 pr_warning("XOFF->XOFF transition\n");
 425                 return NETDEV_TX_OK;
 426         }
 427         dev->stats.tx_packets++;
 428         dev->stats.tx_bytes += skb->len;
 429         vcc->send(vcc, skb);
 430         if (atm_may_send(vcc, 0)) {
 431                 entry->vccs->xoff = 0;
 432                 return NETDEV_TX_OK;
 433         }
 434         spin_lock_irqsave(&clip_priv->xoff_lock, flags);
 435         netif_stop_queue(dev);  /* XOFF -> throttle immediately */
 436         barrier();
 437         if (!entry->vccs->xoff)
 438                 netif_start_queue(dev);
 439         /* Oh, we just raced with clip_pop. netif_start_queue should be
 440            good enough, because nothing should really be asleep because
 441            of the brief netif_stop_queue. If this isn't true or if it
 442            changes, use netif_wake_queue instead. */
 443         spin_unlock_irqrestore(&clip_priv->xoff_lock, flags);
 444         return NETDEV_TX_OK;
 445 }
 446
 447 static int clip_mkip(struct atm_vcc *vcc, int timeout)
 448 {
 449         struct sk_buff_head *rq, queue;
 450         struct clip_vcc *clip_vcc;
 451         struct sk_buff *skb, *tmp;
 452         unsigned long flags;
 453
 454         if (!vcc->push)
 455                 return -EBADFD;
 456         clip_vcc = kmalloc(sizeof(struct clip_vcc), GFP_KERNEL);
 457         if (!clip_vcc)
 458                 return -ENOMEM;
 459         pr_debug("%p vcc %p\n", clip_vcc, vcc);
 460         clip_vcc->vcc = vcc;
 461         vcc->user_back = clip_vcc;
 462         set_bit(ATM_VF_IS_CLIP, &vcc->flags);
 463         clip_vcc->entry = NULL;
 464         clip_vcc->xoff = 0;
 465         clip_vcc->encap = 1;
 466         clip_vcc->last_use = jiffies;
 467         clip_vcc->idle_timeout = timeout * HZ;
 468         clip_vcc->old_push = vcc->push;
 469         clip_vcc->old_pop = vcc->pop;
 470         vcc->push = clip_push;
 471         vcc->pop = clip_pop;
 472
 473         __skb_queue_head_init(&queue);
 474         rq = &sk_atm(vcc)->sk_receive_queue;
 475
 476         spin_lock_irqsave(&rq->lock, flags);
 477         skb_queue_splice_init(rq, &queue);
 478         spin_unlock_irqrestore(&rq->lock, flags);
 479
 480         /* re-process everything received between connection setup and MKIP */
 481         skb_queue_walk_safe(&queue, skb, tmp) {
 482                 if (!clip_devs) {
 483                         atm_return(vcc, skb->truesize);
 484                         kfree_skb(skb);
 485                 } else {
 486                         struct net_device *dev = skb->dev;
 487                         unsigned int len = skb->len;
 488
 489                         skb_get(skb);
 490                         clip_push(vcc, skb);
 491                         dev->stats.rx_packets--;
 492                         dev->stats.rx_bytes -= len;
 493                         kfree_skb(skb);
 494                 }
 495         }
 496         return 0;
 497 }
 498
 499 static int clip_setentry(struct atm_vcc *vcc, __be32 ip)
 500 {
 501         struct neighbour *neigh;
 502         struct atmarp_entry *entry;
 503         int error;
 504         struct clip_vcc *clip_vcc;
 505         struct flowi fl = { .fl4_dst = ip,
 506                             .fl4_tos = 1 };
 507         struct rtable *rt;
 508
 509         if (vcc->push != clip_push) {
 510                 pr_warning("non-CLIP VCC\n");
 511                 return -EBADF;
 512         }
 513         clip_vcc = CLIP_VCC(vcc);
 514         if (!ip) {
 515                 if (!clip_vcc->entry) {
 516                         pr_err("hiding hidden ATMARP entry\n");
 517                         return 0;
 518                 }
 519                 pr_debug("remove\n");
 520                 unlink_clip_vcc(clip_vcc);
 521                 return 0;
 522         }
 523         error = ip_route_output_key(&init_net, &rt, &fl);
 524         if (error)
 525                 return error;
 526         neigh = __neigh_lookup(&clip_tbl, &ip, rt->dst.dev, 1);
 527         ip_rt_put(rt);
 528         if (!neigh)
 529                 return -ENOMEM;
 530         entry = NEIGH2ENTRY(neigh);
 531         if (entry != clip_vcc->entry) {
 532                 if (!clip_vcc->entry)
 533                         pr_debug("add\n");
 534                 else {
 535                         pr_debug("update\n");
 536                         unlink_clip_vcc(clip_vcc);
 537                 }
 538                 link_vcc(clip_vcc, entry);
 539         }
 540         error = neigh_update(neigh, llc_oui, NUD_PERMANENT,
 541                              NEIGH_UPDATE_F_OVERRIDE | NEIGH_UPDATE_F_ADMIN);
 542         neigh_release(neigh);
 543         return error;
 544 }
 545
 546 static const struct net_device_ops clip_netdev_ops = {
 547         .ndo_start_xmit = clip_start_xmit,
 548 };
 549
 550 static void clip_setup(struct net_device *dev)
 551 {
 552         dev->netdev_ops = &clip_netdev_ops;
 553         dev->type = ARPHRD_ATM;
 554         dev->hard_header_len = RFC1483LLC_LEN;
 555         dev->mtu = RFC1626_MTU;
 556         dev->tx_queue_len = 100;        /* "normal" queue (packets) */
 557         /* When using a "real" qdisc, the qdisc determines the queue */
 558         /* length. tx_queue_len is only used for the default case, */
 559         /* without any more elaborate queuing. 100 is a reasonable */
 560         /* compromise between decent burst-tolerance and protection */
 561         /* against memory hogs. */
 562         dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
 563 }
 564
 565 static int clip_create(int number)
 566 {
 567         struct net_device *dev;
 568         struct clip_priv *clip_priv;
 569         int error;
 570
 571         if (number != -1) {
 572                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
 573                         if (PRIV(dev)->number == number)
 574                                 return -EEXIST;
 575         } else {
 576                 number = 0;
 577                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
 578                         if (PRIV(dev)->number >= number)
 579                                 number = PRIV(dev)->number + 1;
 580         }
 581         dev = alloc_netdev(sizeof(struct clip_priv), "", clip_setup);
 582         if (!dev)
 583                 return -ENOMEM;
 584         clip_priv = PRIV(dev);
 585         sprintf(dev->name, "atm%d", number);
 586         spin_lock_init(&clip_priv->xoff_lock);
 587         clip_priv->number = number;
 588         error = register_netdev(dev);
 589         if (error) {
 590                 free_netdev(dev);
 591                 return error;
 592         }
 593         clip_priv->next = clip_devs;
 594         clip_devs = dev;
 595         pr_debug("registered (net:%s)\n", dev->name);
 596         return number;
 597 }
 598
 599 static int clip_device_event(struct notifier_block *this, unsigned long event,
 600                              void *arg)
 601 {
 602         struct net_device *dev = arg;
 603
 604         if (!net_eq(dev_net(dev), &init_net))
 605                 return NOTIFY_DONE;
 606
 607         if (event == NETDEV_UNREGISTER) {
 608                 neigh_ifdown(&clip_tbl, dev);
 609                 return NOTIFY_DONE;
 610         }
 611
 612         /* ignore non-CLIP devices */
 613         if (dev->type != ARPHRD_ATM || dev->netdev_ops != &clip_netdev_ops)
 614                 return NOTIFY_DONE;
 615
 616         switch (event) {
 617         case NETDEV_UP:
 618                 pr_debug("NETDEV_UP\n");
 619                 to_atmarpd(act_up, PRIV(dev)->number, 0);
 620                 break;
 621         case NETDEV_GOING_DOWN:
 622                 pr_debug("NETDEV_DOWN\n");
 623                 to_atmarpd(act_down, PRIV(dev)->number, 0);
 624                 break;
 625         case NETDEV_CHANGE:
 626         case NETDEV_CHANGEMTU:
 627                 pr_debug("NETDEV_CHANGE*\n");
 628                 to_atmarpd(act_change, PRIV(dev)->number, 0);
 629                 break;
 630         }
 631         return NOTIFY_DONE;
 632 }
 633
 634 static int clip_inet_event(struct notifier_block *this, unsigned long event,
 635                            void *ifa)
 636 {
 637         struct in_device *in_dev;
 638
 639         in_dev = ((struct in_ifaddr *)ifa)->ifa_dev;
 640         /*
 641          * Transitions are of the down-change-up type, so it's sufficient to
 642          * handle the change on up.
 643          */
 644         if (event != NETDEV_UP)
 645                 return NOTIFY_DONE;
 646         return clip_device_event(this, NETDEV_CHANGE, in_dev->dev);
 647 }
 648
 649 static struct notifier_block clip_dev_notifier = {
 650         .notifier_call = clip_device_event,
 651 };
 652
 653
 654
 655 static struct notifier_block clip_inet_notifier = {
 656         .notifier_call = clip_inet_event,
 657 };
 658
 659
 660
 661 static void atmarpd_close(struct atm_vcc *vcc)
 662 {
 663         pr_debug("\n");
 664
 665         rtnl_lock();
 666         atmarpd = NULL;
 667         skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
 668         rtnl_unlock();
 669
 670         pr_debug("(done)\n");
 671         module_put(THIS_MODULE);
 672 }
 673
 674 static struct atmdev_ops atmarpd_dev_ops = {
 675         .close = atmarpd_close
 676 };
 677
 678
 679 static struct atm_dev atmarpd_dev = {
 680         .ops =                  &atmarpd_dev_ops,
 681         .type =                 "arpd",
 682         .number =               999,
 683         .lock =                 __SPIN_LOCK_UNLOCKED(atmarpd_dev.lock)
 684 };
 685
 686
 687 static int atm_init_atmarp(struct atm_vcc *vcc)
 688 {
 689         rtnl_lock();
 690         if (atmarpd) {
 691                 rtnl_unlock();
 692                 return -EADDRINUSE;
 693         }
 694
 695         mod_timer(&idle_timer, jiffies + CLIP_CHECK_INTERVAL * HZ);
 696
 697         atmarpd = vcc;
 698         set_bit(ATM_VF_META, &vcc->flags);
 699         set_bit(ATM_VF_READY, &vcc->flags);
 700             /* allow replies and avoid getting closed if signaling dies */
 701         vcc->dev = &atmarpd_dev;
 702         vcc_insert_socket(sk_atm(vcc));
 703         vcc->push = NULL;
 704         vcc->pop = NULL; /* crash */
 705         vcc->push_oam = NULL; /* crash */
 706         rtnl_unlock();
 707         return 0;
 708 }
 709
 710 static int clip_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 711 {
 712         struct atm_vcc *vcc = ATM_SD(sock);
 713         int err = 0;
 714
 715         switch (cmd) {
 716         case SIOCMKCLIP:
 717         case ATMARPD_CTRL:
 718         case ATMARP_MKIP:
 719         case ATMARP_SETENTRY:
 720         case ATMARP_ENCAP:
 721                 if (!capable(CAP_NET_ADMIN))
 722                         return -EPERM;
 723                 break;
 724         default:
 725                 return -ENOIOCTLCMD;
 726         }
 727
 728         switch (cmd) {
 729         case SIOCMKCLIP:
 730                 err = clip_create(arg);
 731                 break;
 732         case ATMARPD_CTRL:
 733                 err = atm_init_atmarp(vcc);
 734                 if (!err) {
 735                         sock->state = SS_CONNECTED;
 736                         __module_get(THIS_MODULE);
 737                 }
 738                 break;
 739         case ATMARP_MKIP:
 740                 err = clip_mkip(vcc, arg);
 741                 break;
 742         case ATMARP_SETENTRY:
 743                 err = clip_setentry(vcc, (__force __be32)arg);
 744                 break;
 745         case ATMARP_ENCAP:
 746                 err = clip_encap(vcc, arg);
 747                 break;
 748         }
 749         return err;
 750 }
 751
 752 static struct atm_ioctl clip_ioctl_ops = {
 753         .owner = THIS_MODULE,
 754         .ioctl = clip_ioctl,
 755 };
 756
 757 #ifdef CONFIG_PROC_FS
 758
 759 static void svc_addr(struct seq_file *seq, struct sockaddr_atmsvc *addr)
 760 {
 761         static int code[] = { 1, 2, 10, 6, 1, 0 };
 762         static int e164[] = { 1, 8, 4, 6, 1, 0 };
 763
 764         if (*addr->sas_addr.pub) {
 765                 seq_printf(seq, "%s", addr->sas_addr.pub);
 766                 if (*addr->sas_addr.prv)
 767                         seq_putc(seq, '+');
 768         } else if (!*addr->sas_addr.prv) {
 769                 seq_printf(seq, "%s", "(none)");
 770                 return;
 771         }
 772         if (*addr->sas_addr.prv) {
 773                 unsigned char *prv = addr->sas_addr.prv;
 774                 int *fields;
 775                 int i, j;
 776
 777                 fields = *prv == ATM_AFI_E164 ? e164 : code;
 778                 for (i = 0; fields[i]; i++) {
 779                         for (j = fields[i]; j; j--)
 780                                 seq_printf(seq, "%02X", *prv++);
 781                         if (fields[i + 1])
 782                                 seq_putc(seq, '.');
 783                 }
 784         }
 785 }
 786
 787 /* This means the neighbour entry has no attached VCC objects. */
 788 #define SEQ_NO_VCC_TOKEN        ((void *) 2)
 789
 790 static void atmarp_info(struct seq_file *seq, struct net_device *dev,
 791                         struct atmarp_entry *entry, struct clip_vcc *clip_vcc)
 792 {
 793         unsigned long exp;
 794         char buf[17];
 795         int svc, llc, off;
 796
 797         svc = ((clip_vcc == SEQ_NO_VCC_TOKEN) ||
 798                (sk_atm(clip_vcc->vcc)->sk_family == AF_ATMSVC));
 799
 800         llc = ((clip_vcc == SEQ_NO_VCC_TOKEN) || clip_vcc->encap);
 801
 802         if (clip_vcc == SEQ_NO_VCC_TOKEN)
 803                 exp = entry->neigh->used;
 804         else
 805                 exp = clip_vcc->last_use;
 806
 807         exp = (jiffies - exp) / HZ;
 808
 809         seq_printf(seq, "%-6s%-4s%-4s%5ld ",
 810                    dev->name, svc ? "SVC" : "PVC", llc ? "LLC" : "NULL", exp);
 811
 812         off = scnprintf(buf, sizeof(buf) - 1, "%pI4",
 813                         &entry->ip);
 814         while (off < 16)
 815                 buf[off++] = ' ';
 816         buf[off] = '\0';
 817         seq_printf(seq, "%s", buf);
 818
 819         if (clip_vcc == SEQ_NO_VCC_TOKEN) {
 820                 if (time_before(jiffies, entry->expires))
 821                         seq_printf(seq, "(resolving)\n");
 822                 else
 823                         seq_printf(seq, "(expired, ref %d)\n",
 824                                    atomic_read(&entry->neigh->refcnt));
 825         } else if (!svc) {
 826                 seq_printf(seq, "%d.%d.%d\n",
 827                            clip_vcc->vcc->dev->number,
 828                            clip_vcc->vcc->vpi, clip_vcc->vcc->vci);
 829         } else {
 830                 svc_addr(seq, &clip_vcc->vcc->remote);
 831                 seq_putc(seq, '\n');
 832         }
 833 }
 834
 835 struct clip_seq_state {
 836         /* This member must be first. */
 837         struct neigh_seq_state ns;
 838
 839         /* Local to clip specific iteration. */
 840         struct clip_vcc *vcc;
 841 };
 842
 843 static struct clip_vcc *clip_seq_next_vcc(struct atmarp_entry *e,
 844                                           struct clip_vcc *curr)
 845 {
 846         if (!curr) {
 847                 curr = e->vccs;
 848                 if (!curr)
 849                         return SEQ_NO_VCC_TOKEN;
 850                 return curr;
 851         }
 852         if (curr == SEQ_NO_VCC_TOKEN)
 853                 return NULL;
 854
 855         curr = curr->next;
 856
 857         return curr;
 858 }
 859
 860 static void *clip_seq_vcc_walk(struct clip_seq_state *state,
 861                                struct atmarp_entry *e, loff_t * pos)
 862 {
 863         struct clip_vcc *vcc = state->vcc;
 864
 865         vcc = clip_seq_next_vcc(e, vcc);
 866         if (vcc && pos != NULL) {
 867                 while (*pos) {
 868                         vcc = clip_seq_next_vcc(e, vcc);
 869                         if (!vcc)
 870                                 break;
 871                         --(*pos);
 872                 }
 873         }
 874         state->vcc = vcc;
 875
 876         return vcc;
 877 }
 878
 879 static void *clip_seq_sub_iter(struct neigh_seq_state *_state,
 880                                struct neighbour *n, loff_t * pos)
 881 {
 882         struct clip_seq_state *state = (struct clip_seq_state *)_state;
 883
 884         return clip_seq_vcc_walk(state, NEIGH2ENTRY(n), pos);
 885 }
 886
 887 static void *clip_seq_start(struct seq_file *seq, loff_t * pos)
 888 {
 889         struct clip_seq_state *state = seq->private;
 890         state->ns.neigh_sub_iter = clip_seq_sub_iter;
 891         return neigh_seq_start(seq, pos, &clip_tbl, NEIGH_SEQ_NEIGH_ONLY);
 892 }
 893
 894 static int clip_seq_show(struct seq_file *seq, void *v)
 895 {
 896         static char atm_arp_banner[] =
 897             "IPitf TypeEncp Idle IP address      ATM address\n";
 898
 899         if (v == SEQ_START_TOKEN) {
 900                 seq_puts(seq, atm_arp_banner);
 901         } else {
 902                 struct clip_seq_state *state = seq->private;
 903                 struct neighbour *n = v;
 904                 struct clip_vcc *vcc = state->vcc;
 905
 906                 atmarp_info(seq, n->dev, NEIGH2ENTRY(n), vcc);
 907         }
 908         return 0;
 909 }
 910
 911 static const struct seq_operations arp_seq_ops = {
 912         .start  = clip_seq_start,
 913         .next   = neigh_seq_next,
 914         .stop   = neigh_seq_stop,
 915         .show   = clip_seq_show,
 916 };
 917
 918 static int arp_seq_open(struct inode *inode, struct file *file)
 919 {
 920         return seq_open_net(inode, file, &arp_seq_ops,
 921                             sizeof(struct clip_seq_state));
 922 }
 923
 924 static const struct file_operations arp_seq_fops = {
 925         .open           = arp_seq_open,
 926         .read           = seq_read,
 927         .llseek         = seq_lseek,
 928         .release        = seq_release_net,
 929         .owner          = THIS_MODULE
 930 };
 931 #endif
 932
 933 static void atm_clip_exit_noproc(void);
 934
 935 static int __init atm_clip_init(void)
 936 {
 937         neigh_table_init_no_netlink(&clip_tbl);
 938
 939         clip_tbl_hook = &clip_tbl;
 940         register_atm_ioctl(&clip_ioctl_ops);
 941         register_netdevice_notifier(&clip_dev_notifier);
 942         register_inetaddr_notifier(&clip_inet_notifier);
 943
 944         setup_timer(&idle_timer, idle_timer_check, 0);
 945
 946 #ifdef CONFIG_PROC_FS
 947         {
 948                 struct proc_dir_entry *p;
 949
 950                 p = proc_create("arp", S_IRUGO, atm_proc_root, &arp_seq_fops);
 951                 if (!p) {
 952                         pr_err("Unable to initialize /proc/net/atm/arp\n");
 953                         atm_clip_exit_noproc();
 954                         return -ENOMEM;
 955                 }
 956         }
 957 #endif
 958
 959         return 0;
 960 }
 961
 962 static void atm_clip_exit_noproc(void)
 963 {
 964         struct net_device *dev, *next;
 965
 966         unregister_inetaddr_notifier(&clip_inet_notifier);
 967         unregister_netdevice_notifier(&clip_dev_notifier);
 968
 969         deregister_atm_ioctl(&clip_ioctl_ops);
 970
 971         /* First, stop the idle timer, so it stops banging
 972          * on the table.
 973          */
 974         del_timer_sync(&idle_timer);
 975
 976         /* Next, purge the table, so that the device
 977          * unregister loop below does not hang due to
 978          * device references remaining in the table.
 979          */
 980         neigh_ifdown(&clip_tbl, NULL);
 981
 982         dev = clip_devs;
 983         while (dev) {
 984                 next = PRIV(dev)->next;
 985                 unregister_netdev(dev);
 986                 free_netdev(dev);
 987                 dev = next;
 988         }
 989
 990         /* Now it is safe to fully shutdown whole table. */
 991         neigh_table_clear(&clip_tbl);
 992
 993         clip_tbl_hook = NULL;
 994 }
 995
 996 static void __exit atm_clip_exit(void)
 997 {
 998         remove_proc_entry("arp", atm_proc_root);
 999
1000         atm_clip_exit_noproc();
1001 }
1002
1003 module_init(atm_clip_init);
1004 module_exit(atm_clip_exit);
1005 MODULE_AUTHOR("Werner Almesberger");
1006 MODULE_DESCRIPTION("Classical/IP over ATM interface");
1007 MODULE_LICENSE("GPL");