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