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 dst_entry *dst = skb_dst(skb);
 368         struct atmarp_entry *entry;
 369         struct neighbour *n;
 370         struct atm_vcc *vcc;
 371         int old;
 372         unsigned long flags;
 373
 374         pr_debug("(skb %p)\n", skb);
 375         if (!dst) {
 376                 pr_err("skb_dst(skb) == NULL\n");
 377                 dev_kfree_skb(skb);
 378                 dev->stats.tx_dropped++;
 379                 return NETDEV_TX_OK;
 380         }
 381         n = dst_get_neighbour(dst);
 382         if (!n) {
 383 #if 0
 384                 n = clip_find_neighbour(skb_dst(skb), 1);
 385                 if (!n) {
 386                         dev_kfree_skb(skb);     /* lost that one */
 387                         dev->stats.tx_dropped++;
 388                         return 0;
 389                 }
 390                 dst_set_neighbour(dst, n);
 391 #endif
 392                 pr_err("NO NEIGHBOUR !\n");
 393                 dev_kfree_skb(skb);
 394                 dev->stats.tx_dropped++;
 395                 return NETDEV_TX_OK;
 396         }
 397         entry = NEIGH2ENTRY(n);
 398         if (!entry->vccs) {
 399                 if (time_after(jiffies, entry->expires)) {
 400                         /* should be resolved */
 401                         entry->expires = jiffies + ATMARP_RETRY_DELAY * HZ;
 402                         to_atmarpd(act_need, PRIV(dev)->number, entry->ip);
 403                 }
 404                 if (entry->neigh->arp_queue.qlen < ATMARP_MAX_UNRES_PACKETS)
 405                         skb_queue_tail(&entry->neigh->arp_queue, skb);
 406                 else {
 407                         dev_kfree_skb(skb);
 408                         dev->stats.tx_dropped++;
 409                 }
 410                 return NETDEV_TX_OK;
 411         }
 412         pr_debug("neigh %p, vccs %p\n", entry, entry->vccs);
 413         ATM_SKB(skb)->vcc = vcc = entry->vccs->vcc;
 414         pr_debug("using neighbour %p, vcc %p\n", n, vcc);
 415         if (entry->vccs->encap) {
 416                 void *here;
 417
 418                 here = skb_push(skb, RFC1483LLC_LEN);
 419                 memcpy(here, llc_oui, sizeof(llc_oui));
 420                 ((__be16 *) here)[3] = skb->protocol;
 421         }
 422         atomic_add(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
 423         ATM_SKB(skb)->atm_options = vcc->atm_options;
 424         entry->vccs->last_use = jiffies;
 425         pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, vcc, vcc->dev);
 426         old = xchg(&entry->vccs->xoff, 1);      /* assume XOFF ... */
 427         if (old) {
 428                 pr_warning("XOFF->XOFF transition\n");
 429                 return NETDEV_TX_OK;
 430         }
 431         dev->stats.tx_packets++;
 432         dev->stats.tx_bytes += skb->len;
 433         vcc->send(vcc, skb);
 434         if (atm_may_send(vcc, 0)) {
 435                 entry->vccs->xoff = 0;
 436                 return NETDEV_TX_OK;
 437         }
 438         spin_lock_irqsave(&clip_priv->xoff_lock, flags);
 439         netif_stop_queue(dev);  /* XOFF -> throttle immediately */
 440         barrier();
 441         if (!entry->vccs->xoff)
 442                 netif_start_queue(dev);
 443         /* Oh, we just raced with clip_pop. netif_start_queue should be
 444            good enough, because nothing should really be asleep because
 445            of the brief netif_stop_queue. If this isn't true or if it
 446            changes, use netif_wake_queue instead. */
 447         spin_unlock_irqrestore(&clip_priv->xoff_lock, flags);
 448         return NETDEV_TX_OK;
 449 }
 450
 451 static int clip_mkip(struct atm_vcc *vcc, int timeout)
 452 {
 453         struct sk_buff_head *rq, queue;
 454         struct clip_vcc *clip_vcc;
 455         struct sk_buff *skb, *tmp;
 456         unsigned long flags;
 457
 458         if (!vcc->push)
 459                 return -EBADFD;
 460         clip_vcc = kmalloc(sizeof(struct clip_vcc), GFP_KERNEL);
 461         if (!clip_vcc)
 462                 return -ENOMEM;
 463         pr_debug("%p vcc %p\n", clip_vcc, vcc);
 464         clip_vcc->vcc = vcc;
 465         vcc->user_back = clip_vcc;
 466         set_bit(ATM_VF_IS_CLIP, &vcc->flags);
 467         clip_vcc->entry = NULL;
 468         clip_vcc->xoff = 0;
 469         clip_vcc->encap = 1;
 470         clip_vcc->last_use = jiffies;
 471         clip_vcc->idle_timeout = timeout * HZ;
 472         clip_vcc->old_push = vcc->push;
 473         clip_vcc->old_pop = vcc->pop;
 474         vcc->push = clip_push;
 475         vcc->pop = clip_pop;
 476
 477         __skb_queue_head_init(&queue);
 478         rq = &sk_atm(vcc)->sk_receive_queue;
 479
 480         spin_lock_irqsave(&rq->lock, flags);
 481         skb_queue_splice_init(rq, &queue);
 482         spin_unlock_irqrestore(&rq->lock, flags);
 483
 484         /* re-process everything received between connection setup and MKIP */
 485         skb_queue_walk_safe(&queue, skb, tmp) {
 486                 if (!clip_devs) {
 487                         atm_return(vcc, skb->truesize);
 488                         kfree_skb(skb);
 489                 } else {
 490                         struct net_device *dev = skb->dev;
 491                         unsigned int len = skb->len;
 492
 493                         skb_get(skb);
 494                         clip_push(vcc, skb);
 495                         dev->stats.rx_packets--;
 496                         dev->stats.rx_bytes -= len;
 497                         kfree_skb(skb);
 498                 }
 499         }
 500         return 0;
 501 }
 502
 503 static int clip_setentry(struct atm_vcc *vcc, __be32 ip)
 504 {
 505         struct neighbour *neigh;
 506         struct atmarp_entry *entry;
 507         int error;
 508         struct clip_vcc *clip_vcc;
 509         struct rtable *rt;
 510
 511         if (vcc->push != clip_push) {
 512                 pr_warning("non-CLIP VCC\n");
 513                 return -EBADF;
 514         }
 515         clip_vcc = CLIP_VCC(vcc);
 516         if (!ip) {
 517                 if (!clip_vcc->entry) {
 518                         pr_err("hiding hidden ATMARP entry\n");
 519                         return 0;
 520                 }
 521                 pr_debug("remove\n");
 522                 unlink_clip_vcc(clip_vcc);
 523                 return 0;
 524         }
 525         rt = ip_route_output(&init_net, ip, 0, 1, 0);
 526         if (IS_ERR(rt))
 527                 return PTR_ERR(rt);
 528         neigh = __neigh_lookup(&clip_tbl, &ip, rt->dst.dev, 1);
 529         ip_rt_put(rt);
 530         if (!neigh)
 531                 return -ENOMEM;
 532         entry = NEIGH2ENTRY(neigh);
 533         if (entry != clip_vcc->entry) {
 534                 if (!clip_vcc->entry)
 535                         pr_debug("add\n");
 536                 else {
 537                         pr_debug("update\n");
 538                         unlink_clip_vcc(clip_vcc);
 539                 }
 540                 link_vcc(clip_vcc, entry);
 541         }
 542         error = neigh_update(neigh, llc_oui, NUD_PERMANENT,
 543                              NEIGH_UPDATE_F_OVERRIDE | NEIGH_UPDATE_F_ADMIN);
 544         neigh_release(neigh);
 545         return error;
 546 }
 547
 548 static const struct net_device_ops clip_netdev_ops = {
 549         .ndo_start_xmit = clip_start_xmit,
 550 };
 551
 552 static void clip_setup(struct net_device *dev)
 553 {
 554         dev->netdev_ops = &clip_netdev_ops;
 555         dev->type = ARPHRD_ATM;
 556         dev->hard_header_len = RFC1483LLC_LEN;
 557         dev->mtu = RFC1626_MTU;
 558         dev->tx_queue_len = 100;        /* "normal" queue (packets) */
 559         /* When using a "real" qdisc, the qdisc determines the queue */
 560         /* length. tx_queue_len is only used for the default case, */
 561         /* without any more elaborate queuing. 100 is a reasonable */
 562         /* compromise between decent burst-tolerance and protection */
 563         /* against memory hogs. */
 564         dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
 565 }
 566
 567 static int clip_create(int number)
 568 {
 569         struct net_device *dev;
 570         struct clip_priv *clip_priv;
 571         int error;
 572
 573         if (number != -1) {
 574                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
 575                         if (PRIV(dev)->number == number)
 576                                 return -EEXIST;
 577         } else {
 578                 number = 0;
 579                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
 580                         if (PRIV(dev)->number >= number)
 581                                 number = PRIV(dev)->number + 1;
 582         }
 583         dev = alloc_netdev(sizeof(struct clip_priv), "", clip_setup);
 584         if (!dev)
 585                 return -ENOMEM;
 586         clip_priv = PRIV(dev);
 587         sprintf(dev->name, "atm%d", number);
 588         spin_lock_init(&clip_priv->xoff_lock);
 589         clip_priv->number = number;
 590         error = register_netdev(dev);
 591         if (error) {
 592                 free_netdev(dev);
 593                 return error;
 594         }
 595         clip_priv->next = clip_devs;
 596         clip_devs = dev;
 597         pr_debug("registered (net:%s)\n", dev->name);
 598         return number;
 599 }
 600
 601 static int clip_device_event(struct notifier_block *this, unsigned long event,
 602                              void *arg)
 603 {
 604         struct net_device *dev = arg;
 605
 606         if (!net_eq(dev_net(dev), &init_net))
 607                 return NOTIFY_DONE;
 608
 609         if (event == NETDEV_UNREGISTER) {
 610                 neigh_ifdown(&clip_tbl, dev);
 611                 return NOTIFY_DONE;
 612         }
 613
 614         /* ignore non-CLIP devices */
 615         if (dev->type != ARPHRD_ATM || dev->netdev_ops != &clip_netdev_ops)
 616                 return NOTIFY_DONE;
 617
 618         switch (event) {
 619         case NETDEV_UP:
 620                 pr_debug("NETDEV_UP\n");
 621                 to_atmarpd(act_up, PRIV(dev)->number, 0);
 622                 break;
 623         case NETDEV_GOING_DOWN:
 624                 pr_debug("NETDEV_DOWN\n");
 625                 to_atmarpd(act_down, PRIV(dev)->number, 0);
 626                 break;
 627         case NETDEV_CHANGE:
 628         case NETDEV_CHANGEMTU:
 629                 pr_debug("NETDEV_CHANGE*\n");
 630                 to_atmarpd(act_change, PRIV(dev)->number, 0);
 631                 break;
 632         }
 633         return NOTIFY_DONE;
 634 }
 635
 636 static int clip_inet_event(struct notifier_block *this, unsigned long event,
 637                            void *ifa)
 638 {
 639         struct in_device *in_dev;
 640
 641         in_dev = ((struct in_ifaddr *)ifa)->ifa_dev;
 642         /*
 643          * Transitions are of the down-change-up type, so it's sufficient to
 644          * handle the change on up.
 645          */
 646         if (event != NETDEV_UP)
 647                 return NOTIFY_DONE;
 648         return clip_device_event(this, NETDEV_CHANGE, in_dev->dev);
 649 }
 650
 651 static struct notifier_block clip_dev_notifier = {
 652         .notifier_call = clip_device_event,
 653 };
 654
 655
 656
 657 static struct notifier_block clip_inet_notifier = {
 658         .notifier_call = clip_inet_event,
 659 };
 660
 661
 662
 663 static void atmarpd_close(struct atm_vcc *vcc)
 664 {
 665         pr_debug("\n");
 666
 667         rtnl_lock();
 668         atmarpd = NULL;
 669         skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
 670         rtnl_unlock();
 671
 672         pr_debug("(done)\n");
 673         module_put(THIS_MODULE);
 674 }
 675
 676 static struct atmdev_ops atmarpd_dev_ops = {
 677         .close = atmarpd_close
 678 };
 679
 680
 681 static struct atm_dev atmarpd_dev = {
 682         .ops =                  &atmarpd_dev_ops,
 683         .type =                 "arpd",
 684         .number =               999,
 685         .lock =                 __SPIN_LOCK_UNLOCKED(atmarpd_dev.lock)
 686 };
 687
 688
 689 static int atm_init_atmarp(struct atm_vcc *vcc)
 690 {
 691         rtnl_lock();
 692         if (atmarpd) {
 693                 rtnl_unlock();
 694                 return -EADDRINUSE;
 695         }
 696
 697         mod_timer(&idle_timer, jiffies + CLIP_CHECK_INTERVAL * HZ);
 698
 699         atmarpd = vcc;
 700         set_bit(ATM_VF_META, &vcc->flags);
 701         set_bit(ATM_VF_READY, &vcc->flags);
 702             /* allow replies and avoid getting closed if signaling dies */
 703         vcc->dev = &atmarpd_dev;
 704         vcc_insert_socket(sk_atm(vcc));
 705         vcc->push = NULL;
 706         vcc->pop = NULL; /* crash */
 707         vcc->push_oam = NULL; /* crash */
 708         rtnl_unlock();
 709         return 0;
 710 }
 711
 712 static int clip_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 713 {
 714         struct atm_vcc *vcc = ATM_SD(sock);
 715         int err = 0;
 716
 717         switch (cmd) {
 718         case SIOCMKCLIP:
 719         case ATMARPD_CTRL:
 720         case ATMARP_MKIP:
 721         case ATMARP_SETENTRY:
 722         case ATMARP_ENCAP:
 723                 if (!capable(CAP_NET_ADMIN))
 724                         return -EPERM;
 725                 break;
 726         default:
 727                 return -ENOIOCTLCMD;
 728         }
 729
 730         switch (cmd) {
 731         case SIOCMKCLIP:
 732                 err = clip_create(arg);
 733                 break;
 734         case ATMARPD_CTRL:
 735                 err = atm_init_atmarp(vcc);
 736                 if (!err) {
 737                         sock->state = SS_CONNECTED;
 738                         __module_get(THIS_MODULE);
 739                 }
 740                 break;
 741         case ATMARP_MKIP:
 742                 err = clip_mkip(vcc, arg);
 743                 break;
 744         case ATMARP_SETENTRY:
 745                 err = clip_setentry(vcc, (__force __be32)arg);
 746                 break;
 747         case ATMARP_ENCAP:
 748                 err = clip_encap(vcc, arg);
 749                 break;
 750         }
 751         return err;
 752 }
 753
 754 static struct atm_ioctl clip_ioctl_ops = {
 755         .owner = THIS_MODULE,
 756         .ioctl = clip_ioctl,
 757 };
 758
 759 #ifdef CONFIG_PROC_FS
 760
 761 static void svc_addr(struct seq_file *seq, struct sockaddr_atmsvc *addr)
 762 {
 763         static int code[] = { 1, 2, 10, 6, 1, 0 };
 764         static int e164[] = { 1, 8, 4, 6, 1, 0 };
 765
 766         if (*addr->sas_addr.pub) {
 767                 seq_printf(seq, "%s", addr->sas_addr.pub);
 768                 if (*addr->sas_addr.prv)
 769                         seq_putc(seq, '+');
 770         } else if (!*addr->sas_addr.prv) {
 771                 seq_printf(seq, "%s", "(none)");
 772                 return;
 773         }
 774         if (*addr->sas_addr.prv) {
 775                 unsigned char *prv = addr->sas_addr.prv;
 776                 int *fields;
 777                 int i, j;
 778
 779                 fields = *prv == ATM_AFI_E164 ? e164 : code;
 780                 for (i = 0; fields[i]; i++) {
 781                         for (j = fields[i]; j; j--)
 782                                 seq_printf(seq, "%02X", *prv++);
 783                         if (fields[i + 1])
 784                                 seq_putc(seq, '.');
 785                 }
 786         }
 787 }
 788
 789 /* This means the neighbour entry has no attached VCC objects. */
 790 #define SEQ_NO_VCC_TOKEN        ((void *) 2)
 791
 792 static void atmarp_info(struct seq_file *seq, struct net_device *dev,
 793                         struct atmarp_entry *entry, struct clip_vcc *clip_vcc)
 794 {
 795         unsigned long exp;
 796         char buf[17];
 797         int svc, llc, off;
 798
 799         svc = ((clip_vcc == SEQ_NO_VCC_TOKEN) ||
 800                (sk_atm(clip_vcc->vcc)->sk_family == AF_ATMSVC));
 801
 802         llc = ((clip_vcc == SEQ_NO_VCC_TOKEN) || clip_vcc->encap);
 803
 804         if (clip_vcc == SEQ_NO_VCC_TOKEN)
 805                 exp = entry->neigh->used;
 806         else
 807                 exp = clip_vcc->last_use;
 808
 809         exp = (jiffies - exp) / HZ;
 810
 811         seq_printf(seq, "%-6s%-4s%-4s%5ld ",
 812                    dev->name, svc ? "SVC" : "PVC", llc ? "LLC" : "NULL", exp);
 813
 814         off = scnprintf(buf, sizeof(buf) - 1, "%pI4",
 815                         &entry->ip);
 816         while (off < 16)
 817                 buf[off++] = ' ';
 818         buf[off] = '\0';
 819         seq_printf(seq, "%s", buf);
 820
 821         if (clip_vcc == SEQ_NO_VCC_TOKEN) {
 822                 if (time_before(jiffies, entry->expires))
 823                         seq_printf(seq, "(resolving)\n");
 824                 else
 825                         seq_printf(seq, "(expired, ref %d)\n",
 826                                    atomic_read(&entry->neigh->refcnt));
 827         } else if (!svc) {
 828                 seq_printf(seq, "%d.%d.%d\n",
 829                            clip_vcc->vcc->dev->number,
 830                            clip_vcc->vcc->vpi, clip_vcc->vcc->vci);
 831         } else {
 832                 svc_addr(seq, &clip_vcc->vcc->remote);
 833                 seq_putc(seq, '\n');
 834         }
 835 }
 836
 837 struct clip_seq_state {
 838         /* This member must be first. */
 839         struct neigh_seq_state ns;
 840
 841         /* Local to clip specific iteration. */
 842         struct clip_vcc *vcc;
 843 };
 844
 845 static struct clip_vcc *clip_seq_next_vcc(struct atmarp_entry *e,
 846                                           struct clip_vcc *curr)
 847 {
 848         if (!curr) {
 849                 curr = e->vccs;
 850                 if (!curr)
 851                         return SEQ_NO_VCC_TOKEN;
 852                 return curr;
 853         }
 854         if (curr == SEQ_NO_VCC_TOKEN)
 855                 return NULL;
 856
 857         curr = curr->next;
 858
 859         return curr;
 860 }
 861
 862 static void *clip_seq_vcc_walk(struct clip_seq_state *state,
 863                                struct atmarp_entry *e, loff_t * pos)
 864 {
 865         struct clip_vcc *vcc = state->vcc;
 866
 867         vcc = clip_seq_next_vcc(e, vcc);
 868         if (vcc && pos != NULL) {
 869                 while (*pos) {
 870                         vcc = clip_seq_next_vcc(e, vcc);
 871                         if (!vcc)
 872                                 break;
 873                         --(*pos);
 874                 }
 875         }
 876         state->vcc = vcc;
 877
 878         return vcc;
 879 }
 880
 881 static void *clip_seq_sub_iter(struct neigh_seq_state *_state,
 882                                struct neighbour *n, loff_t * pos)
 883 {
 884         struct clip_seq_state *state = (struct clip_seq_state *)_state;
 885
 886         return clip_seq_vcc_walk(state, NEIGH2ENTRY(n), pos);
 887 }
 888
 889 static void *clip_seq_start(struct seq_file *seq, loff_t * pos)
 890 {
 891         struct clip_seq_state *state = seq->private;
 892         state->ns.neigh_sub_iter = clip_seq_sub_iter;
 893         return neigh_seq_start(seq, pos, &clip_tbl, NEIGH_SEQ_NEIGH_ONLY);
 894 }
 895
 896 static int clip_seq_show(struct seq_file *seq, void *v)
 897 {
 898         static char atm_arp_banner[] =
 899             "IPitf TypeEncp Idle IP address      ATM address\n";
 900
 901         if (v == SEQ_START_TOKEN) {
 902                 seq_puts(seq, atm_arp_banner);
 903         } else {
 904                 struct clip_seq_state *state = seq->private;
 905                 struct neighbour *n = v;
 906                 struct clip_vcc *vcc = state->vcc;
 907
 908                 atmarp_info(seq, n->dev, NEIGH2ENTRY(n), vcc);
 909         }
 910         return 0;
 911 }
 912
 913 static const struct seq_operations arp_seq_ops = {
 914         .start  = clip_seq_start,
 915         .next   = neigh_seq_next,
 916         .stop   = neigh_seq_stop,
 917         .show   = clip_seq_show,
 918 };
 919
 920 static int arp_seq_open(struct inode *inode, struct file *file)
 921 {
 922         return seq_open_net(inode, file, &arp_seq_ops,
 923                             sizeof(struct clip_seq_state));
 924 }
 925
 926 static const struct file_operations arp_seq_fops = {
 927         .open           = arp_seq_open,
 928         .read           = seq_read,
 929         .llseek         = seq_lseek,
 930         .release        = seq_release_net,
 931         .owner          = THIS_MODULE
 932 };
 933 #endif
 934
 935 static void atm_clip_exit_noproc(void);
 936
 937 static int __init atm_clip_init(void)
 938 {
 939         neigh_table_init_no_netlink(&clip_tbl);
 940
 941         clip_tbl_hook = &clip_tbl;
 942         register_atm_ioctl(&clip_ioctl_ops);
 943         register_netdevice_notifier(&clip_dev_notifier);
 944         register_inetaddr_notifier(&clip_inet_notifier);
 945
 946         setup_timer(&idle_timer, idle_timer_check, 0);
 947
 948 #ifdef CONFIG_PROC_FS
 949         {
 950                 struct proc_dir_entry *p;
 951
 952                 p = proc_create("arp", S_IRUGO, atm_proc_root, &arp_seq_fops);
 953                 if (!p) {
 954                         pr_err("Unable to initialize /proc/net/atm/arp\n");
 955                         atm_clip_exit_noproc();
 956                         return -ENOMEM;
 957                 }
 958         }
 959 #endif
 960
 961         return 0;
 962 }
 963
 964 static void atm_clip_exit_noproc(void)
 965 {
 966         struct net_device *dev, *next;
 967
 968         unregister_inetaddr_notifier(&clip_inet_notifier);
 969         unregister_netdevice_notifier(&clip_dev_notifier);
 970
 971         deregister_atm_ioctl(&clip_ioctl_ops);
 972
 973         /* First, stop the idle timer, so it stops banging
 974          * on the table.
 975          */
 976         del_timer_sync(&idle_timer);
 977
 978         /* Next, purge the table, so that the device
 979          * unregister loop below does not hang due to
 980          * device references remaining in the table.
 981          */
 982         neigh_ifdown(&clip_tbl, NULL);
 983
 984         dev = clip_devs;
 985         while (dev) {
 986                 next = PRIV(dev)->next;
 987                 unregister_netdev(dev);
 988                 free_netdev(dev);
 989                 dev = next;
 990         }
 991
 992         /* Now it is safe to fully shutdown whole table. */
 993         neigh_table_clear(&clip_tbl);
 994
 995         clip_tbl_hook = NULL;
 996 }
 997
 998 static void __exit atm_clip_exit(void)
 999 {
1000         remove_proc_entry("arp", atm_proc_root);
1001
1002         atm_clip_exit_noproc();
1003 }
1004
1005 module_init(atm_clip_init);
1006 module_exit(atm_clip_exit);
1007 MODULE_AUTHOR("Werner Almesberger");
1008 MODULE_DESCRIPTION("Classical/IP over ATM interface");
1009 MODULE_LICENSE("GPL");