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