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TOMOYO Linux Cross Reference
Linux/net/atm/clip.c

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  1 // SPDX-License-Identifier: GPL-2.0-only
  2 /* net/atm/clip.c - RFC1577 Classical IP over ATM */
  3 
  4 /* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */
  5 
  6 #define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
  7 
  8 #include <linux/string.h>
  9 #include <linux/errno.h>
 10 #include <linux/kernel.h> /* for UINT_MAX */
 11 #include <linux/module.h>
 12 #include <linux/init.h>
 13 #include <linux/netdevice.h>
 14 #include <linux/skbuff.h>
 15 #include <linux/wait.h>
 16 #include <linux/timer.h>
 17 #include <linux/if_arp.h> /* for some manifest constants */
 18 #include <linux/notifier.h>
 19 #include <linux/atm.h>
 20 #include <linux/atmdev.h>
 21 #include <linux/atmclip.h>
 22 #include <linux/atmarp.h>
 23 #include <linux/capability.h>
 24 #include <linux/ip.h> /* for net/route.h */
 25 #include <linux/in.h> /* for struct sockaddr_in */
 26 #include <linux/if.h> /* for IFF_UP */
 27 #include <linux/inetdevice.h>
 28 #include <linux/bitops.h>
 29 #include <linux/poison.h>
 30 #include <linux/proc_fs.h>
 31 #include <linux/seq_file.h>
 32 #include <linux/rcupdate.h>
 33 #include <linux/jhash.h>
 34 #include <linux/slab.h>
 35 #include <net/route.h> /* for struct rtable and routing */
 36 #include <net/icmp.h> /* icmp_send */
 37 #include <net/arp.h>
 38 #include <linux/param.h> /* for HZ */
 39 #include <linux/uaccess.h>
 40 #include <asm/byteorder.h> /* for htons etc. */
 41 #include <linux/atomic.h>
 42 
 43 #include "common.h"
 44 #include "resources.h"
 45 #include <net/atmclip.h>
 46 
 47 static struct net_device *clip_devs;
 48 static struct atm_vcc *atmarpd;
 49 static struct timer_list idle_timer;
 50 static const struct neigh_ops clip_neigh_ops;
 51 
 52 static int to_atmarpd(enum atmarp_ctrl_type type, int itf, __be32 ip)
 53 {
 54         struct sock *sk;
 55         struct atmarp_ctrl *ctrl;
 56         struct sk_buff *skb;
 57 
 58         pr_debug("(%d)\n", type);
 59         if (!atmarpd)
 60                 return -EUNATCH;
 61         skb = alloc_skb(sizeof(struct atmarp_ctrl), GFP_ATOMIC);
 62         if (!skb)
 63                 return -ENOMEM;
 64         ctrl = skb_put(skb, sizeof(struct atmarp_ctrl));
 65         ctrl->type = type;
 66         ctrl->itf_num = itf;
 67         ctrl->ip = ip;
 68         atm_force_charge(atmarpd, skb->truesize);
 69 
 70         sk = sk_atm(atmarpd);
 71         skb_queue_tail(&sk->sk_receive_queue, skb);
 72         sk->sk_data_ready(sk);
 73         return 0;
 74 }
 75 
 76 static void link_vcc(struct clip_vcc *clip_vcc, struct atmarp_entry *entry)
 77 {
 78         pr_debug("%p to entry %p (neigh %p)\n", clip_vcc, entry, entry->neigh);
 79         clip_vcc->entry = entry;
 80         clip_vcc->xoff = 0;     /* @@@ may overrun buffer by one packet */
 81         clip_vcc->next = entry->vccs;
 82         entry->vccs = clip_vcc;
 83         entry->neigh->used = jiffies;
 84 }
 85 
 86 static void unlink_clip_vcc(struct clip_vcc *clip_vcc)
 87 {
 88         struct atmarp_entry *entry = clip_vcc->entry;
 89         struct clip_vcc **walk;
 90 
 91         if (!entry) {
 92                 pr_err("!clip_vcc->entry (clip_vcc %p)\n", clip_vcc);
 93                 return;
 94         }
 95         netif_tx_lock_bh(entry->neigh->dev);    /* block clip_start_xmit() */
 96         entry->neigh->used = jiffies;
 97         for (walk = &entry->vccs; *walk; walk = &(*walk)->next)
 98                 if (*walk == clip_vcc) {
 99                         int error;
100 
101                         *walk = clip_vcc->next; /* atomic */
102                         clip_vcc->entry = NULL;
103                         if (clip_vcc->xoff)
104                                 netif_wake_queue(entry->neigh->dev);
105                         if (entry->vccs)
106                                 goto out;
107                         entry->expires = jiffies - 1;
108                         /* force resolution or expiration */
109                         error = neigh_update(entry->neigh, NULL, NUD_NONE,
110                                              NEIGH_UPDATE_F_ADMIN, 0);
111                         if (error)
112                                 pr_err("neigh_update failed with %d\n", error);
113                         goto out;
114                 }
115         pr_err("ATMARP: failed (entry %p, vcc 0x%p)\n", entry, clip_vcc);
116 out:
117         netif_tx_unlock_bh(entry->neigh->dev);
118 }
119 
120 /* The neighbour entry n->lock is held. */
121 static int neigh_check_cb(struct neighbour *n)
122 {
123         struct atmarp_entry *entry = neighbour_priv(n);
124         struct clip_vcc *cv;
125 
126         if (n->ops != &clip_neigh_ops)
127                 return 0;
128         for (cv = entry->vccs; cv; cv = cv->next) {
129                 unsigned long exp = cv->last_use + cv->idle_timeout;
130 
131                 if (cv->idle_timeout && time_after(jiffies, exp)) {
132                         pr_debug("releasing vcc %p->%p of entry %p\n",
133                                  cv, cv->vcc, entry);
134                         vcc_release_async(cv->vcc, -ETIMEDOUT);
135                 }
136         }
137 
138         if (entry->vccs || time_before(jiffies, entry->expires))
139                 return 0;
140 
141         if (refcount_read(&n->refcnt) > 1) {
142                 struct sk_buff *skb;
143 
144                 pr_debug("destruction postponed with ref %d\n",
145                          refcount_read(&n->refcnt));
146 
147                 while ((skb = skb_dequeue(&n->arp_queue)) != NULL)
148                         dev_kfree_skb(skb);
149 
150                 return 0;
151         }
152 
153         pr_debug("expired neigh %p\n", n);
154         return 1;
155 }
156 
157 static void idle_timer_check(struct timer_list *unused)
158 {
159         write_lock(&arp_tbl.lock);
160         __neigh_for_each_release(&arp_tbl, neigh_check_cb);
161         mod_timer(&idle_timer, jiffies + CLIP_CHECK_INTERVAL * HZ);
162         write_unlock(&arp_tbl.lock);
163 }
164 
165 static int clip_arp_rcv(struct sk_buff *skb)
166 {
167         struct atm_vcc *vcc;
168 
169         pr_debug("\n");
170         vcc = ATM_SKB(skb)->vcc;
171         if (!vcc || !atm_charge(vcc, skb->truesize)) {
172                 dev_kfree_skb_any(skb);
173                 return 0;
174         }
175         pr_debug("pushing to %p\n", vcc);
176         pr_debug("using %p\n", CLIP_VCC(vcc)->old_push);
177         CLIP_VCC(vcc)->old_push(vcc, skb);
178         return 0;
179 }
180 
181 static const unsigned char llc_oui[] = {
182         0xaa,   /* DSAP: non-ISO */
183         0xaa,   /* SSAP: non-ISO */
184         0x03,   /* Ctrl: Unnumbered Information Command PDU */
185         0x00,   /* OUI: EtherType */
186         0x00,
187         0x00
188 };
189 
190 static void clip_push(struct atm_vcc *vcc, struct sk_buff *skb)
191 {
192         struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
193 
194         pr_debug("\n");
195 
196         if (!clip_devs) {
197                 atm_return(vcc, skb->truesize);
198                 kfree_skb(skb);
199                 return;
200         }
201 
202         if (!skb) {
203                 pr_debug("removing VCC %p\n", clip_vcc);
204                 if (clip_vcc->entry)
205                         unlink_clip_vcc(clip_vcc);
206                 clip_vcc->old_push(vcc, NULL);  /* pass on the bad news */
207                 kfree(clip_vcc);
208                 return;
209         }
210         atm_return(vcc, skb->truesize);
211         skb->dev = clip_vcc->entry ? clip_vcc->entry->neigh->dev : clip_devs;
212         /* clip_vcc->entry == NULL if we don't have an IP address yet */
213         if (!skb->dev) {
214                 dev_kfree_skb_any(skb);
215                 return;
216         }
217         ATM_SKB(skb)->vcc = vcc;
218         skb_reset_mac_header(skb);
219         if (!clip_vcc->encap ||
220             skb->len < RFC1483LLC_LEN ||
221             memcmp(skb->data, llc_oui, sizeof(llc_oui)))
222                 skb->protocol = htons(ETH_P_IP);
223         else {
224                 skb->protocol = ((__be16 *)skb->data)[3];
225                 skb_pull(skb, RFC1483LLC_LEN);
226                 if (skb->protocol == htons(ETH_P_ARP)) {
227                         skb->dev->stats.rx_packets++;
228                         skb->dev->stats.rx_bytes += skb->len;
229                         clip_arp_rcv(skb);
230                         return;
231                 }
232         }
233         clip_vcc->last_use = jiffies;
234         skb->dev->stats.rx_packets++;
235         skb->dev->stats.rx_bytes += skb->len;
236         memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
237         netif_rx(skb);
238 }
239 
240 /*
241  * Note: these spinlocks _must_not_ block on non-SMP. The only goal is that
242  * clip_pop is atomic with respect to the critical section in clip_start_xmit.
243  */
244 
245 static void clip_pop(struct atm_vcc *vcc, struct sk_buff *skb)
246 {
247         struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
248         struct net_device *dev = skb->dev;
249         int old;
250         unsigned long flags;
251 
252         pr_debug("(vcc %p)\n", vcc);
253         clip_vcc->old_pop(vcc, skb);
254         /* skb->dev == NULL in outbound ARP packets */
255         if (!dev)
256                 return;
257         spin_lock_irqsave(&PRIV(dev)->xoff_lock, flags);
258         if (atm_may_send(vcc, 0)) {
259                 old = xchg(&clip_vcc->xoff, 0);
260                 if (old)
261                         netif_wake_queue(dev);
262         }
263         spin_unlock_irqrestore(&PRIV(dev)->xoff_lock, flags);
264 }
265 
266 static void clip_neigh_solicit(struct neighbour *neigh, struct sk_buff *skb)
267 {
268         __be32 *ip = (__be32 *) neigh->primary_key;
269 
270         pr_debug("(neigh %p, skb %p)\n", neigh, skb);
271         to_atmarpd(act_need, PRIV(neigh->dev)->number, *ip);
272 }
273 
274 static void clip_neigh_error(struct neighbour *neigh, struct sk_buff *skb)
275 {
276 #ifndef CONFIG_ATM_CLIP_NO_ICMP
277         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
278 #endif
279         kfree_skb(skb);
280 }
281 
282 static const struct neigh_ops clip_neigh_ops = {
283         .family =               AF_INET,
284         .solicit =              clip_neigh_solicit,
285         .error_report =         clip_neigh_error,
286         .output =               neigh_direct_output,
287         .connected_output =     neigh_direct_output,
288 };
289 
290 static int clip_constructor(struct net_device *dev, struct neighbour *neigh)
291 {
292         struct atmarp_entry *entry = neighbour_priv(neigh);
293 
294         if (neigh->tbl->family != AF_INET)
295                 return -EINVAL;
296 
297         if (neigh->type != RTN_UNICAST)
298                 return -EINVAL;
299 
300         neigh->nud_state = NUD_NONE;
301         neigh->ops = &clip_neigh_ops;
302         neigh->output = neigh->ops->output;
303         entry->neigh = neigh;
304         entry->vccs = NULL;
305         entry->expires = jiffies - 1;
306 
307         return 0;
308 }
309 
310 /* @@@ copy bh locking from arp.c -- need to bh-enable atm code before */
311 
312 /*
313  * We play with the resolve flag: 0 and 1 have the usual meaning, but -1 means
314  * to allocate the neighbour entry but not to ask atmarpd for resolution. Also,
315  * don't increment the usage count. This is used to create entries in
316  * clip_setentry.
317  */
318 
319 static int clip_encap(struct atm_vcc *vcc, int mode)
320 {
321         if (!CLIP_VCC(vcc))
322                 return -EBADFD;
323 
324         CLIP_VCC(vcc)->encap = mode;
325         return 0;
326 }
327 
328 static netdev_tx_t clip_start_xmit(struct sk_buff *skb,
329                                    struct net_device *dev)
330 {
331         struct clip_priv *clip_priv = PRIV(dev);
332         struct dst_entry *dst = skb_dst(skb);
333         struct atmarp_entry *entry;
334         struct neighbour *n;
335         struct atm_vcc *vcc;
336         struct rtable *rt;
337         __be32 *daddr;
338         int old;
339         unsigned long flags;
340 
341         pr_debug("(skb %p)\n", skb);
342         if (!dst) {
343                 pr_err("skb_dst(skb) == NULL\n");
344                 dev_kfree_skb(skb);
345                 dev->stats.tx_dropped++;
346                 return NETDEV_TX_OK;
347         }
348         rt = dst_rtable(dst);
349         if (rt->rt_gw_family == AF_INET)
350                 daddr = &rt->rt_gw4;
351         else
352                 daddr = &ip_hdr(skb)->daddr;
353         n = dst_neigh_lookup(dst, daddr);
354         if (!n) {
355                 pr_err("NO NEIGHBOUR !\n");
356                 dev_kfree_skb(skb);
357                 dev->stats.tx_dropped++;
358                 return NETDEV_TX_OK;
359         }
360         entry = neighbour_priv(n);
361         if (!entry->vccs) {
362                 if (time_after(jiffies, entry->expires)) {
363                         /* should be resolved */
364                         entry->expires = jiffies + ATMARP_RETRY_DELAY * HZ;
365                         to_atmarpd(act_need, PRIV(dev)->number, *((__be32 *)n->primary_key));
366                 }
367                 if (entry->neigh->arp_queue.qlen < ATMARP_MAX_UNRES_PACKETS)
368                         skb_queue_tail(&entry->neigh->arp_queue, skb);
369                 else {
370                         dev_kfree_skb(skb);
371                         dev->stats.tx_dropped++;
372                 }
373                 goto out_release_neigh;
374         }
375         pr_debug("neigh %p, vccs %p\n", entry, entry->vccs);
376         ATM_SKB(skb)->vcc = vcc = entry->vccs->vcc;
377         pr_debug("using neighbour %p, vcc %p\n", n, vcc);
378         if (entry->vccs->encap) {
379                 void *here;
380 
381                 here = skb_push(skb, RFC1483LLC_LEN);
382                 memcpy(here, llc_oui, sizeof(llc_oui));
383                 ((__be16 *) here)[3] = skb->protocol;
384         }
385         atm_account_tx(vcc, skb);
386         entry->vccs->last_use = jiffies;
387         pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, vcc, vcc->dev);
388         old = xchg(&entry->vccs->xoff, 1);      /* assume XOFF ... */
389         if (old) {
390                 pr_warn("XOFF->XOFF transition\n");
391                 goto out_release_neigh;
392         }
393         dev->stats.tx_packets++;
394         dev->stats.tx_bytes += skb->len;
395         vcc->send(vcc, skb);
396         if (atm_may_send(vcc, 0)) {
397                 entry->vccs->xoff = 0;
398                 goto out_release_neigh;
399         }
400         spin_lock_irqsave(&clip_priv->xoff_lock, flags);
401         netif_stop_queue(dev);  /* XOFF -> throttle immediately */
402         barrier();
403         if (!entry->vccs->xoff)
404                 netif_start_queue(dev);
405         /* Oh, we just raced with clip_pop. netif_start_queue should be
406            good enough, because nothing should really be asleep because
407            of the brief netif_stop_queue. If this isn't true or if it
408            changes, use netif_wake_queue instead. */
409         spin_unlock_irqrestore(&clip_priv->xoff_lock, flags);
410 out_release_neigh:
411         neigh_release(n);
412         return NETDEV_TX_OK;
413 }
414 
415 static int clip_mkip(struct atm_vcc *vcc, int timeout)
416 {
417         struct clip_vcc *clip_vcc;
418 
419         if (!vcc->push)
420                 return -EBADFD;
421         clip_vcc = kmalloc(sizeof(struct clip_vcc), GFP_KERNEL);
422         if (!clip_vcc)
423                 return -ENOMEM;
424         pr_debug("%p vcc %p\n", clip_vcc, vcc);
425         clip_vcc->vcc = vcc;
426         vcc->user_back = clip_vcc;
427         set_bit(ATM_VF_IS_CLIP, &vcc->flags);
428         clip_vcc->entry = NULL;
429         clip_vcc->xoff = 0;
430         clip_vcc->encap = 1;
431         clip_vcc->last_use = jiffies;
432         clip_vcc->idle_timeout = timeout * HZ;
433         clip_vcc->old_push = vcc->push;
434         clip_vcc->old_pop = vcc->pop;
435         vcc->push = clip_push;
436         vcc->pop = clip_pop;
437 
438         /* re-process everything received between connection setup and MKIP */
439         vcc_process_recv_queue(vcc);
440 
441         return 0;
442 }
443 
444 static int clip_setentry(struct atm_vcc *vcc, __be32 ip)
445 {
446         struct neighbour *neigh;
447         struct atmarp_entry *entry;
448         int error;
449         struct clip_vcc *clip_vcc;
450         struct rtable *rt;
451 
452         if (vcc->push != clip_push) {
453                 pr_warn("non-CLIP VCC\n");
454                 return -EBADF;
455         }
456         clip_vcc = CLIP_VCC(vcc);
457         if (!ip) {
458                 if (!clip_vcc->entry) {
459                         pr_err("hiding hidden ATMARP entry\n");
460                         return 0;
461                 }
462                 pr_debug("remove\n");
463                 unlink_clip_vcc(clip_vcc);
464                 return 0;
465         }
466         rt = ip_route_output(&init_net, ip, 0, 0, 0, RT_SCOPE_LINK);
467         if (IS_ERR(rt))
468                 return PTR_ERR(rt);
469         neigh = __neigh_lookup(&arp_tbl, &ip, rt->dst.dev, 1);
470         ip_rt_put(rt);
471         if (!neigh)
472                 return -ENOMEM;
473         entry = neighbour_priv(neigh);
474         if (entry != clip_vcc->entry) {
475                 if (!clip_vcc->entry)
476                         pr_debug("add\n");
477                 else {
478                         pr_debug("update\n");
479                         unlink_clip_vcc(clip_vcc);
480                 }
481                 link_vcc(clip_vcc, entry);
482         }
483         error = neigh_update(neigh, llc_oui, NUD_PERMANENT,
484                              NEIGH_UPDATE_F_OVERRIDE | NEIGH_UPDATE_F_ADMIN, 0);
485         neigh_release(neigh);
486         return error;
487 }
488 
489 static const struct net_device_ops clip_netdev_ops = {
490         .ndo_start_xmit         = clip_start_xmit,
491         .ndo_neigh_construct    = clip_constructor,
492 };
493 
494 static void clip_setup(struct net_device *dev)
495 {
496         dev->netdev_ops = &clip_netdev_ops;
497         dev->type = ARPHRD_ATM;
498         dev->neigh_priv_len = sizeof(struct atmarp_entry);
499         dev->hard_header_len = RFC1483LLC_LEN;
500         dev->mtu = RFC1626_MTU;
501         dev->tx_queue_len = 100;        /* "normal" queue (packets) */
502         /* When using a "real" qdisc, the qdisc determines the queue */
503         /* length. tx_queue_len is only used for the default case, */
504         /* without any more elaborate queuing. 100 is a reasonable */
505         /* compromise between decent burst-tolerance and protection */
506         /* against memory hogs. */
507         netif_keep_dst(dev);
508 }
509 
510 static int clip_create(int number)
511 {
512         struct net_device *dev;
513         struct clip_priv *clip_priv;
514         int error;
515 
516         if (number != -1) {
517                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
518                         if (PRIV(dev)->number == number)
519                                 return -EEXIST;
520         } else {
521                 number = 0;
522                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
523                         if (PRIV(dev)->number >= number)
524                                 number = PRIV(dev)->number + 1;
525         }
526         dev = alloc_netdev(sizeof(struct clip_priv), "", NET_NAME_UNKNOWN,
527                            clip_setup);
528         if (!dev)
529                 return -ENOMEM;
530         clip_priv = PRIV(dev);
531         sprintf(dev->name, "atm%d", number);
532         spin_lock_init(&clip_priv->xoff_lock);
533         clip_priv->number = number;
534         error = register_netdev(dev);
535         if (error) {
536                 free_netdev(dev);
537                 return error;
538         }
539         clip_priv->next = clip_devs;
540         clip_devs = dev;
541         pr_debug("registered (net:%s)\n", dev->name);
542         return number;
543 }
544 
545 static int clip_device_event(struct notifier_block *this, unsigned long event,
546                              void *ptr)
547 {
548         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
549 
550         if (!net_eq(dev_net(dev), &init_net))
551                 return NOTIFY_DONE;
552 
553         if (event == NETDEV_UNREGISTER)
554                 return NOTIFY_DONE;
555 
556         /* ignore non-CLIP devices */
557         if (dev->type != ARPHRD_ATM || dev->netdev_ops != &clip_netdev_ops)
558                 return NOTIFY_DONE;
559 
560         switch (event) {
561         case NETDEV_UP:
562                 pr_debug("NETDEV_UP\n");
563                 to_atmarpd(act_up, PRIV(dev)->number, 0);
564                 break;
565         case NETDEV_GOING_DOWN:
566                 pr_debug("NETDEV_DOWN\n");
567                 to_atmarpd(act_down, PRIV(dev)->number, 0);
568                 break;
569         case NETDEV_CHANGE:
570         case NETDEV_CHANGEMTU:
571                 pr_debug("NETDEV_CHANGE*\n");
572                 to_atmarpd(act_change, PRIV(dev)->number, 0);
573                 break;
574         }
575         return NOTIFY_DONE;
576 }
577 
578 static int clip_inet_event(struct notifier_block *this, unsigned long event,
579                            void *ifa)
580 {
581         struct in_device *in_dev;
582         struct netdev_notifier_info info;
583 
584         in_dev = ((struct in_ifaddr *)ifa)->ifa_dev;
585         /*
586          * Transitions are of the down-change-up type, so it's sufficient to
587          * handle the change on up.
588          */
589         if (event != NETDEV_UP)
590                 return NOTIFY_DONE;
591         netdev_notifier_info_init(&info, in_dev->dev);
592         return clip_device_event(this, NETDEV_CHANGE, &info);
593 }
594 
595 static struct notifier_block clip_dev_notifier = {
596         .notifier_call = clip_device_event,
597 };
598 
599 
600 
601 static struct notifier_block clip_inet_notifier = {
602         .notifier_call = clip_inet_event,
603 };
604 
605 
606 
607 static void atmarpd_close(struct atm_vcc *vcc)
608 {
609         pr_debug("\n");
610 
611         rtnl_lock();
612         atmarpd = NULL;
613         skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
614         rtnl_unlock();
615 
616         pr_debug("(done)\n");
617         module_put(THIS_MODULE);
618 }
619 
620 static const struct atmdev_ops atmarpd_dev_ops = {
621         .close = atmarpd_close
622 };
623 
624 
625 static struct atm_dev atmarpd_dev = {
626         .ops =                  &atmarpd_dev_ops,
627         .type =                 "arpd",
628         .number =               999,
629         .lock =                 __SPIN_LOCK_UNLOCKED(atmarpd_dev.lock)
630 };
631 
632 
633 static int atm_init_atmarp(struct atm_vcc *vcc)
634 {
635         rtnl_lock();
636         if (atmarpd) {
637                 rtnl_unlock();
638                 return -EADDRINUSE;
639         }
640 
641         mod_timer(&idle_timer, jiffies + CLIP_CHECK_INTERVAL * HZ);
642 
643         atmarpd = vcc;
644         set_bit(ATM_VF_META, &vcc->flags);
645         set_bit(ATM_VF_READY, &vcc->flags);
646             /* allow replies and avoid getting closed if signaling dies */
647         vcc->dev = &atmarpd_dev;
648         vcc_insert_socket(sk_atm(vcc));
649         vcc->push = NULL;
650         vcc->pop = NULL; /* crash */
651         vcc->push_oam = NULL; /* crash */
652         rtnl_unlock();
653         return 0;
654 }
655 
656 static int clip_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
657 {
658         struct atm_vcc *vcc = ATM_SD(sock);
659         int err = 0;
660 
661         switch (cmd) {
662         case SIOCMKCLIP:
663         case ATMARPD_CTRL:
664         case ATMARP_MKIP:
665         case ATMARP_SETENTRY:
666         case ATMARP_ENCAP:
667                 if (!capable(CAP_NET_ADMIN))
668                         return -EPERM;
669                 break;
670         default:
671                 return -ENOIOCTLCMD;
672         }
673 
674         switch (cmd) {
675         case SIOCMKCLIP:
676                 err = clip_create(arg);
677                 break;
678         case ATMARPD_CTRL:
679                 err = atm_init_atmarp(vcc);
680                 if (!err) {
681                         sock->state = SS_CONNECTED;
682                         __module_get(THIS_MODULE);
683                 }
684                 break;
685         case ATMARP_MKIP:
686                 err = clip_mkip(vcc, arg);
687                 break;
688         case ATMARP_SETENTRY:
689                 err = clip_setentry(vcc, (__force __be32)arg);
690                 break;
691         case ATMARP_ENCAP:
692                 err = clip_encap(vcc, arg);
693                 break;
694         }
695         return err;
696 }
697 
698 static struct atm_ioctl clip_ioctl_ops = {
699         .owner = THIS_MODULE,
700         .ioctl = clip_ioctl,
701 };
702 
703 #ifdef CONFIG_PROC_FS
704 
705 static void svc_addr(struct seq_file *seq, struct sockaddr_atmsvc *addr)
706 {
707         static int code[] = { 1, 2, 10, 6, 1, 0 };
708         static int e164[] = { 1, 8, 4, 6, 1, 0 };
709 
710         if (*addr->sas_addr.pub) {
711                 seq_printf(seq, "%s", addr->sas_addr.pub);
712                 if (*addr->sas_addr.prv)
713                         seq_putc(seq, '+');
714         } else if (!*addr->sas_addr.prv) {
715                 seq_printf(seq, "%s", "(none)");
716                 return;
717         }
718         if (*addr->sas_addr.prv) {
719                 unsigned char *prv = addr->sas_addr.prv;
720                 int *fields;
721                 int i, j;
722 
723                 fields = *prv == ATM_AFI_E164 ? e164 : code;
724                 for (i = 0; fields[i]; i++) {
725                         for (j = fields[i]; j; j--)
726                                 seq_printf(seq, "%02X", *prv++);
727                         if (fields[i + 1])
728                                 seq_putc(seq, '.');
729                 }
730         }
731 }
732 
733 /* This means the neighbour entry has no attached VCC objects. */
734 #define SEQ_NO_VCC_TOKEN        ((void *) 2)
735 
736 static void atmarp_info(struct seq_file *seq, struct neighbour *n,
737                         struct atmarp_entry *entry, struct clip_vcc *clip_vcc)
738 {
739         struct net_device *dev = n->dev;
740         unsigned long exp;
741         char buf[17];
742         int svc, llc, off;
743 
744         svc = ((clip_vcc == SEQ_NO_VCC_TOKEN) ||
745                (sk_atm(clip_vcc->vcc)->sk_family == AF_ATMSVC));
746 
747         llc = ((clip_vcc == SEQ_NO_VCC_TOKEN) || clip_vcc->encap);
748 
749         if (clip_vcc == SEQ_NO_VCC_TOKEN)
750                 exp = entry->neigh->used;
751         else
752                 exp = clip_vcc->last_use;
753 
754         exp = (jiffies - exp) / HZ;
755 
756         seq_printf(seq, "%-6s%-4s%-4s%5ld ",
757                    dev->name, svc ? "SVC" : "PVC", llc ? "LLC" : "NULL", exp);
758 
759         off = scnprintf(buf, sizeof(buf) - 1, "%pI4", n->primary_key);
760         while (off < 16)
761                 buf[off++] = ' ';
762         buf[off] = '\0';
763         seq_printf(seq, "%s", buf);
764 
765         if (clip_vcc == SEQ_NO_VCC_TOKEN) {
766                 if (time_before(jiffies, entry->expires))
767                         seq_printf(seq, "(resolving)\n");
768                 else
769                         seq_printf(seq, "(expired, ref %d)\n",
770                                    refcount_read(&entry->neigh->refcnt));
771         } else if (!svc) {
772                 seq_printf(seq, "%d.%d.%d\n",
773                            clip_vcc->vcc->dev->number,
774                            clip_vcc->vcc->vpi, clip_vcc->vcc->vci);
775         } else {
776                 svc_addr(seq, &clip_vcc->vcc->remote);
777                 seq_putc(seq, '\n');
778         }
779 }
780 
781 struct clip_seq_state {
782         /* This member must be first. */
783         struct neigh_seq_state ns;
784 
785         /* Local to clip specific iteration. */
786         struct clip_vcc *vcc;
787 };
788 
789 static struct clip_vcc *clip_seq_next_vcc(struct atmarp_entry *e,
790                                           struct clip_vcc *curr)
791 {
792         if (!curr) {
793                 curr = e->vccs;
794                 if (!curr)
795                         return SEQ_NO_VCC_TOKEN;
796                 return curr;
797         }
798         if (curr == SEQ_NO_VCC_TOKEN)
799                 return NULL;
800 
801         curr = curr->next;
802 
803         return curr;
804 }
805 
806 static void *clip_seq_vcc_walk(struct clip_seq_state *state,
807                                struct atmarp_entry *e, loff_t * pos)
808 {
809         struct clip_vcc *vcc = state->vcc;
810 
811         vcc = clip_seq_next_vcc(e, vcc);
812         if (vcc && pos != NULL) {
813                 while (*pos) {
814                         vcc = clip_seq_next_vcc(e, vcc);
815                         if (!vcc)
816                                 break;
817                         --(*pos);
818                 }
819         }
820         state->vcc = vcc;
821 
822         return vcc;
823 }
824 
825 static void *clip_seq_sub_iter(struct neigh_seq_state *_state,
826                                struct neighbour *n, loff_t * pos)
827 {
828         struct clip_seq_state *state = (struct clip_seq_state *)_state;
829 
830         if (n->dev->type != ARPHRD_ATM)
831                 return NULL;
832 
833         return clip_seq_vcc_walk(state, neighbour_priv(n), pos);
834 }
835 
836 static void *clip_seq_start(struct seq_file *seq, loff_t * pos)
837 {
838         struct clip_seq_state *state = seq->private;
839         state->ns.neigh_sub_iter = clip_seq_sub_iter;
840         return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_NEIGH_ONLY);
841 }
842 
843 static int clip_seq_show(struct seq_file *seq, void *v)
844 {
845         static char atm_arp_banner[] =
846             "IPitf TypeEncp Idle IP address      ATM address\n";
847 
848         if (v == SEQ_START_TOKEN) {
849                 seq_puts(seq, atm_arp_banner);
850         } else {
851                 struct clip_seq_state *state = seq->private;
852                 struct clip_vcc *vcc = state->vcc;
853                 struct neighbour *n = v;
854 
855                 atmarp_info(seq, n, neighbour_priv(n), vcc);
856         }
857         return 0;
858 }
859 
860 static const struct seq_operations arp_seq_ops = {
861         .start  = clip_seq_start,
862         .next   = neigh_seq_next,
863         .stop   = neigh_seq_stop,
864         .show   = clip_seq_show,
865 };
866 #endif
867 
868 static void atm_clip_exit_noproc(void);
869 
870 static int __init atm_clip_init(void)
871 {
872         register_atm_ioctl(&clip_ioctl_ops);
873         register_netdevice_notifier(&clip_dev_notifier);
874         register_inetaddr_notifier(&clip_inet_notifier);
875 
876         timer_setup(&idle_timer, idle_timer_check, 0);
877 
878 #ifdef CONFIG_PROC_FS
879         {
880                 struct proc_dir_entry *p;
881 
882                 p = proc_create_net("arp", 0444, atm_proc_root, &arp_seq_ops,
883                                 sizeof(struct clip_seq_state));
884                 if (!p) {
885                         pr_err("Unable to initialize /proc/net/atm/arp\n");
886                         atm_clip_exit_noproc();
887                         return -ENOMEM;
888                 }
889         }
890 #endif
891 
892         return 0;
893 }
894 
895 static void atm_clip_exit_noproc(void)
896 {
897         struct net_device *dev, *next;
898 
899         unregister_inetaddr_notifier(&clip_inet_notifier);
900         unregister_netdevice_notifier(&clip_dev_notifier);
901 
902         deregister_atm_ioctl(&clip_ioctl_ops);
903 
904         /* First, stop the idle timer, so it stops banging
905          * on the table.
906          */
907         del_timer_sync(&idle_timer);
908 
909         dev = clip_devs;
910         while (dev) {
911                 next = PRIV(dev)->next;
912                 unregister_netdev(dev);
913                 free_netdev(dev);
914                 dev = next;
915         }
916 }
917 
918 static void __exit atm_clip_exit(void)
919 {
920         remove_proc_entry("arp", atm_proc_root);
921 
922         atm_clip_exit_noproc();
923 }
924 
925 module_init(atm_clip_init);
926 module_exit(atm_clip_exit);
927 MODULE_AUTHOR("Werner Almesberger");
928 MODULE_DESCRIPTION("Classical/IP over ATM interface");
929 MODULE_LICENSE("GPL");
930 

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