[ATM]: Simplify /proc/net/atm/arp opening
[linux-3.10.git] / 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 #include <linux/string.h>
6 #include <linux/errno.h>
7 #include <linux/kernel.h> /* for UINT_MAX */
8 #include <linux/module.h>
9 #include <linux/init.h>
10 #include <linux/netdevice.h>
11 #include <linux/skbuff.h>
12 #include <linux/wait.h>
13 #include <linux/timer.h>
14 #include <linux/if_arp.h> /* for some manifest constants */
15 #include <linux/notifier.h>
16 #include <linux/atm.h>
17 #include <linux/atmdev.h>
18 #include <linux/atmclip.h>
19 #include <linux/atmarp.h>
20 #include <linux/capability.h>
21 #include <linux/ip.h> /* for net/route.h */
22 #include <linux/in.h> /* for struct sockaddr_in */
23 #include <linux/if.h> /* for IFF_UP */
24 #include <linux/inetdevice.h>
25 #include <linux/bitops.h>
26 #include <linux/poison.h>
27 #include <linux/proc_fs.h>
28 #include <linux/seq_file.h>
29 #include <linux/rcupdate.h>
30 #include <linux/jhash.h>
31 #include <net/route.h> /* for struct rtable and routing */
32 #include <net/icmp.h> /* icmp_send */
33 #include <asm/param.h> /* for HZ */
34 #include <asm/byteorder.h> /* for htons etc. */
35 #include <asm/system.h> /* save/restore_flags */
36 #include <asm/uaccess.h>
37 #include <asm/atomic.h>
38
39 #include "common.h"
40 #include "resources.h"
41 #include <net/atmclip.h>
42
43 static struct net_device *clip_devs;
44 static struct atm_vcc *atmarpd;
45 static struct neigh_table clip_tbl;
46 static struct timer_list idle_timer;
47
48 static int to_atmarpd(enum atmarp_ctrl_type type, int itf, __be32 ip)
49 {
50         struct sock *sk;
51         struct atmarp_ctrl *ctrl;
52         struct sk_buff *skb;
53
54         pr_debug("to_atmarpd(%d)\n", type);
55         if (!atmarpd)
56                 return -EUNATCH;
57         skb = alloc_skb(sizeof(struct atmarp_ctrl),GFP_ATOMIC);
58         if (!skb)
59                 return -ENOMEM;
60         ctrl = (struct atmarp_ctrl *) skb_put(skb,sizeof(struct atmarp_ctrl));
61         ctrl->type = type;
62         ctrl->itf_num = itf;
63         ctrl->ip = ip;
64         atm_force_charge(atmarpd, skb->truesize);
65
66         sk = sk_atm(atmarpd);
67         skb_queue_tail(&sk->sk_receive_queue, skb);
68         sk->sk_data_ready(sk, skb->len);
69         return 0;
70 }
71
72 static void link_vcc(struct clip_vcc *clip_vcc, struct atmarp_entry *entry)
73 {
74         pr_debug("link_vcc %p to entry %p (neigh %p)\n", clip_vcc, entry,
75                 entry->neigh);
76         clip_vcc->entry = entry;
77         clip_vcc->xoff = 0;     /* @@@ may overrun buffer by one packet */
78         clip_vcc->next = entry->vccs;
79         entry->vccs = clip_vcc;
80         entry->neigh->used = jiffies;
81 }
82
83 static void unlink_clip_vcc(struct clip_vcc *clip_vcc)
84 {
85         struct atmarp_entry *entry = clip_vcc->entry;
86         struct clip_vcc **walk;
87
88         if (!entry) {
89                 printk(KERN_CRIT "!clip_vcc->entry (clip_vcc %p)\n", clip_vcc);
90                 return;
91         }
92         netif_tx_lock_bh(entry->neigh->dev);    /* block clip_start_xmit() */
93         entry->neigh->used = jiffies;
94         for (walk = &entry->vccs; *walk; walk = &(*walk)->next)
95                 if (*walk == clip_vcc) {
96                         int error;
97
98                         *walk = clip_vcc->next; /* atomic */
99                         clip_vcc->entry = NULL;
100                         if (clip_vcc->xoff)
101                                 netif_wake_queue(entry->neigh->dev);
102                         if (entry->vccs)
103                                 goto out;
104                         entry->expires = jiffies - 1;
105                         /* force resolution or expiration */
106                         error = neigh_update(entry->neigh, NULL, NUD_NONE,
107                                              NEIGH_UPDATE_F_ADMIN);
108                         if (error)
109                                 printk(KERN_CRIT "unlink_clip_vcc: "
110                                        "neigh_update failed with %d\n", error);
111                         goto out;
112                 }
113         printk(KERN_CRIT "ATMARP: unlink_clip_vcc failed (entry %p, vcc "
114                "0x%p)\n", entry, clip_vcc);
115       out:
116         netif_tx_unlock_bh(entry->neigh->dev);
117 }
118
119 /* The neighbour entry n->lock is held. */
120 static int neigh_check_cb(struct neighbour *n)
121 {
122         struct atmarp_entry *entry = NEIGH2ENTRY(n);
123         struct clip_vcc *cv;
124
125         for (cv = entry->vccs; cv; cv = cv->next) {
126                 unsigned long exp = cv->last_use + cv->idle_timeout;
127
128                 if (cv->idle_timeout && time_after(jiffies, exp)) {
129                         pr_debug("releasing vcc %p->%p of entry %p\n",
130                                 cv, cv->vcc, entry);
131                         vcc_release_async(cv->vcc, -ETIMEDOUT);
132                 }
133         }
134
135         if (entry->vccs || time_before(jiffies, entry->expires))
136                 return 0;
137
138         if (atomic_read(&n->refcnt) > 1) {
139                 struct sk_buff *skb;
140
141                 pr_debug("destruction postponed with ref %d\n",
142                         atomic_read(&n->refcnt));
143
144                 while ((skb = skb_dequeue(&n->arp_queue)) != NULL)
145                         dev_kfree_skb(skb);
146
147                 return 0;
148         }
149
150         pr_debug("expired neigh %p\n", n);
151         return 1;
152 }
153
154 static void idle_timer_check(unsigned long dummy)
155 {
156         write_lock(&clip_tbl.lock);
157         __neigh_for_each_release(&clip_tbl, neigh_check_cb);
158         mod_timer(&idle_timer, jiffies + CLIP_CHECK_INTERVAL * HZ);
159         write_unlock(&clip_tbl.lock);
160 }
161
162 static int clip_arp_rcv(struct sk_buff *skb)
163 {
164         struct atm_vcc *vcc;
165
166         pr_debug("clip_arp_rcv\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("clip push\n");
192         if (!skb) {
193                 pr_debug("removing VCC %p\n", clip_vcc);
194                 if (clip_vcc->entry)
195                         unlink_clip_vcc(clip_vcc);
196                 clip_vcc->old_push(vcc, NULL);  /* pass on the bad news */
197                 kfree(clip_vcc);
198                 return;
199         }
200         atm_return(vcc, skb->truesize);
201         skb->dev = clip_vcc->entry ? clip_vcc->entry->neigh->dev : clip_devs;
202         /* clip_vcc->entry == NULL if we don't have an IP address yet */
203         if (!skb->dev) {
204                 dev_kfree_skb_any(skb);
205                 return;
206         }
207         ATM_SKB(skb)->vcc = vcc;
208         skb_reset_mac_header(skb);
209         if (!clip_vcc->encap
210             || skb->len < RFC1483LLC_LEN
211             || memcmp(skb->data, llc_oui, sizeof (llc_oui)))
212                 skb->protocol = htons(ETH_P_IP);
213         else {
214                 skb->protocol = ((__be16 *) skb->data)[3];
215                 skb_pull(skb, RFC1483LLC_LEN);
216                 if (skb->protocol == htons(ETH_P_ARP)) {
217                         PRIV(skb->dev)->stats.rx_packets++;
218                         PRIV(skb->dev)->stats.rx_bytes += skb->len;
219                         clip_arp_rcv(skb);
220                         return;
221                 }
222         }
223         clip_vcc->last_use = jiffies;
224         PRIV(skb->dev)->stats.rx_packets++;
225         PRIV(skb->dev)->stats.rx_bytes += skb->len;
226         memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
227         netif_rx(skb);
228 }
229
230 /*
231  * Note: these spinlocks _must_not_ block on non-SMP. The only goal is that
232  * clip_pop is atomic with respect to the critical section in clip_start_xmit.
233  */
234
235 static void clip_pop(struct atm_vcc *vcc, struct sk_buff *skb)
236 {
237         struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
238         struct net_device *dev = skb->dev;
239         int old;
240         unsigned long flags;
241
242         pr_debug("clip_pop(vcc %p)\n", vcc);
243         clip_vcc->old_pop(vcc, skb);
244         /* skb->dev == NULL in outbound ARP packets */
245         if (!dev)
246                 return;
247         spin_lock_irqsave(&PRIV(dev)->xoff_lock, flags);
248         if (atm_may_send(vcc, 0)) {
249                 old = xchg(&clip_vcc->xoff, 0);
250                 if (old)
251                         netif_wake_queue(dev);
252         }
253         spin_unlock_irqrestore(&PRIV(dev)->xoff_lock, flags);
254 }
255
256 static void clip_neigh_solicit(struct neighbour *neigh, struct sk_buff *skb)
257 {
258         pr_debug("clip_neigh_solicit (neigh %p, skb %p)\n", neigh, skb);
259         to_atmarpd(act_need, PRIV(neigh->dev)->number, NEIGH2ENTRY(neigh)->ip);
260 }
261
262 static void clip_neigh_error(struct neighbour *neigh, struct sk_buff *skb)
263 {
264 #ifndef CONFIG_ATM_CLIP_NO_ICMP
265         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
266 #endif
267         kfree_skb(skb);
268 }
269
270 static struct neigh_ops clip_neigh_ops = {
271         .family =               AF_INET,
272         .solicit =              clip_neigh_solicit,
273         .error_report =         clip_neigh_error,
274         .output =               dev_queue_xmit,
275         .connected_output =     dev_queue_xmit,
276         .hh_output =            dev_queue_xmit,
277         .queue_xmit =           dev_queue_xmit,
278 };
279
280 static int clip_constructor(struct neighbour *neigh)
281 {
282         struct atmarp_entry *entry = NEIGH2ENTRY(neigh);
283         struct net_device *dev = neigh->dev;
284         struct in_device *in_dev;
285         struct neigh_parms *parms;
286
287         pr_debug("clip_constructor (neigh %p, entry %p)\n", neigh, entry);
288         neigh->type = inet_addr_type(&init_net, entry->ip);
289         if (neigh->type != RTN_UNICAST)
290                 return -EINVAL;
291
292         rcu_read_lock();
293         in_dev = __in_dev_get_rcu(dev);
294         if (!in_dev) {
295                 rcu_read_unlock();
296                 return -EINVAL;
297         }
298
299         parms = in_dev->arp_parms;
300         __neigh_parms_put(neigh->parms);
301         neigh->parms = neigh_parms_clone(parms);
302         rcu_read_unlock();
303
304         neigh->ops = &clip_neigh_ops;
305         neigh->output = neigh->nud_state & NUD_VALID ?
306             neigh->ops->connected_output : neigh->ops->output;
307         entry->neigh = neigh;
308         entry->vccs = NULL;
309         entry->expires = jiffies - 1;
310         return 0;
311 }
312
313 static u32 clip_hash(const void *pkey, const struct net_device *dev)
314 {
315         return jhash_2words(*(u32 *) pkey, dev->ifindex, clip_tbl.hash_rnd);
316 }
317
318 static struct neigh_table clip_tbl = {
319         .family         = AF_INET,
320         .entry_size     = sizeof(struct neighbour)+sizeof(struct atmarp_entry),
321         .key_len        = 4,
322         .hash           = clip_hash,
323         .constructor    = clip_constructor,
324         .id             = "clip_arp_cache",
325
326         /* parameters are copied from ARP ... */
327         .parms = {
328                 .tbl                    = &clip_tbl,
329                 .base_reachable_time    = 30 * HZ,
330                 .retrans_time           = 1 * HZ,
331                 .gc_staletime           = 60 * HZ,
332                 .reachable_time         = 30 * HZ,
333                 .delay_probe_time       = 5 * HZ,
334                 .queue_len              = 3,
335                 .ucast_probes           = 3,
336                 .mcast_probes           = 3,
337                 .anycast_delay          = 1 * HZ,
338                 .proxy_delay            = (8 * HZ) / 10,
339                 .proxy_qlen             = 64,
340                 .locktime               = 1 * HZ,
341         },
342         .gc_interval    = 30 * HZ,
343         .gc_thresh1     = 128,
344         .gc_thresh2     = 512,
345         .gc_thresh3     = 1024,
346 };
347
348 /* @@@ copy bh locking from arp.c -- need to bh-enable atm code before */
349
350 /*
351  * We play with the resolve flag: 0 and 1 have the usual meaning, but -1 means
352  * to allocate the neighbour entry but not to ask atmarpd for resolution. Also,
353  * don't increment the usage count. This is used to create entries in
354  * clip_setentry.
355  */
356
357 static int clip_encap(struct atm_vcc *vcc, int mode)
358 {
359         CLIP_VCC(vcc)->encap = mode;
360         return 0;
361 }
362
363 static int clip_start_xmit(struct sk_buff *skb, struct net_device *dev)
364 {
365         struct clip_priv *clip_priv = PRIV(dev);
366         struct atmarp_entry *entry;
367         struct atm_vcc *vcc;
368         int old;
369         unsigned long flags;
370
371         pr_debug("clip_start_xmit (skb %p)\n", skb);
372         if (!skb->dst) {
373                 printk(KERN_ERR "clip_start_xmit: skb->dst == NULL\n");
374                 dev_kfree_skb(skb);
375                 clip_priv->stats.tx_dropped++;
376                 return 0;
377         }
378         if (!skb->dst->neighbour) {
379 #if 0
380                 skb->dst->neighbour = clip_find_neighbour(skb->dst, 1);
381                 if (!skb->dst->neighbour) {
382                         dev_kfree_skb(skb);     /* lost that one */
383                         clip_priv->stats.tx_dropped++;
384                         return 0;
385                 }
386 #endif
387                 printk(KERN_ERR "clip_start_xmit: NO NEIGHBOUR !\n");
388                 dev_kfree_skb(skb);
389                 clip_priv->stats.tx_dropped++;
390                 return 0;
391         }
392         entry = NEIGH2ENTRY(skb->dst->neighbour);
393         if (!entry->vccs) {
394                 if (time_after(jiffies, entry->expires)) {
395                         /* should be resolved */
396                         entry->expires = jiffies + ATMARP_RETRY_DELAY * HZ;
397                         to_atmarpd(act_need, PRIV(dev)->number, entry->ip);
398                 }
399                 if (entry->neigh->arp_queue.qlen < ATMARP_MAX_UNRES_PACKETS)
400                         skb_queue_tail(&entry->neigh->arp_queue, skb);
401                 else {
402                         dev_kfree_skb(skb);
403                         clip_priv->stats.tx_dropped++;
404                 }
405                 return 0;
406         }
407         pr_debug("neigh %p, vccs %p\n", entry, entry->vccs);
408         ATM_SKB(skb)->vcc = vcc = entry->vccs->vcc;
409         pr_debug("using neighbour %p, vcc %p\n", skb->dst->neighbour, vcc);
410         if (entry->vccs->encap) {
411                 void *here;
412
413                 here = skb_push(skb, RFC1483LLC_LEN);
414                 memcpy(here, llc_oui, sizeof(llc_oui));
415                 ((__be16 *) here)[3] = skb->protocol;
416         }
417         atomic_add(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
418         ATM_SKB(skb)->atm_options = vcc->atm_options;
419         entry->vccs->last_use = jiffies;
420         pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, vcc, vcc->dev);
421         old = xchg(&entry->vccs->xoff, 1);      /* assume XOFF ... */
422         if (old) {
423                 printk(KERN_WARNING "clip_start_xmit: XOFF->XOFF transition\n");
424                 return 0;
425         }
426         clip_priv->stats.tx_packets++;
427         clip_priv->stats.tx_bytes += skb->len;
428         vcc->send(vcc, skb);
429         if (atm_may_send(vcc, 0)) {
430                 entry->vccs->xoff = 0;
431                 return 0;
432         }
433         spin_lock_irqsave(&clip_priv->xoff_lock, flags);
434         netif_stop_queue(dev);  /* XOFF -> throttle immediately */
435         barrier();
436         if (!entry->vccs->xoff)
437                 netif_start_queue(dev);
438         /* Oh, we just raced with clip_pop. netif_start_queue should be
439            good enough, because nothing should really be asleep because
440            of the brief netif_stop_queue. If this isn't true or if it
441            changes, use netif_wake_queue instead. */
442         spin_unlock_irqrestore(&clip_priv->xoff_lock, flags);
443         return 0;
444 }
445
446 static struct net_device_stats *clip_get_stats(struct net_device *dev)
447 {
448         return &PRIV(dev)->stats;
449 }
450
451 static int clip_mkip(struct atm_vcc *vcc, int timeout)
452 {
453         struct clip_vcc *clip_vcc;
454         struct sk_buff *skb;
455         struct sk_buff_head *rq;
456         unsigned long flags;
457
458         if (!vcc->push)
459                 return -EBADFD;
460         clip_vcc = kmalloc(sizeof(struct clip_vcc), GFP_KERNEL);
461         if (!clip_vcc)
462                 return -ENOMEM;
463         pr_debug("mkip clip_vcc %p vcc %p\n", clip_vcc, vcc);
464         clip_vcc->vcc = vcc;
465         vcc->user_back = clip_vcc;
466         set_bit(ATM_VF_IS_CLIP, &vcc->flags);
467         clip_vcc->entry = NULL;
468         clip_vcc->xoff = 0;
469         clip_vcc->encap = 1;
470         clip_vcc->last_use = jiffies;
471         clip_vcc->idle_timeout = timeout * HZ;
472         clip_vcc->old_push = vcc->push;
473         clip_vcc->old_pop = vcc->pop;
474         vcc->push = clip_push;
475         vcc->pop = clip_pop;
476
477         rq = &sk_atm(vcc)->sk_receive_queue;
478
479         spin_lock_irqsave(&rq->lock, flags);
480         if (skb_queue_empty(rq)) {
481                 skb = NULL;
482         } else {
483                 /* NULL terminate the list.  */
484                 rq->prev->next = NULL;
485                 skb = rq->next;
486         }
487         rq->prev = rq->next = (struct sk_buff *)rq;
488         rq->qlen = 0;
489         spin_unlock_irqrestore(&rq->lock, flags);
490
491         /* re-process everything received between connection setup and MKIP */
492         while (skb) {
493                 struct sk_buff *next = skb->next;
494
495                 skb->next = skb->prev = NULL;
496                 if (!clip_devs) {
497                         atm_return(vcc, skb->truesize);
498                         kfree_skb(skb);
499                 } else {
500                         unsigned int len = skb->len;
501
502                         skb_get(skb);
503                         clip_push(vcc, skb);
504                         PRIV(skb->dev)->stats.rx_packets--;
505                         PRIV(skb->dev)->stats.rx_bytes -= len;
506                         kfree_skb(skb);
507                 }
508
509                 skb = next;
510         }
511         return 0;
512 }
513
514 static int clip_setentry(struct atm_vcc *vcc, __be32 ip)
515 {
516         struct neighbour *neigh;
517         struct atmarp_entry *entry;
518         int error;
519         struct clip_vcc *clip_vcc;
520         struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, .tos = 1}} };
521         struct rtable *rt;
522
523         if (vcc->push != clip_push) {
524                 printk(KERN_WARNING "clip_setentry: non-CLIP VCC\n");
525                 return -EBADF;
526         }
527         clip_vcc = CLIP_VCC(vcc);
528         if (!ip) {
529                 if (!clip_vcc->entry) {
530                         printk(KERN_ERR "hiding hidden ATMARP entry\n");
531                         return 0;
532                 }
533                 pr_debug("setentry: remove\n");
534                 unlink_clip_vcc(clip_vcc);
535                 return 0;
536         }
537         error = ip_route_output_key(&rt, &fl);
538         if (error)
539                 return error;
540         neigh = __neigh_lookup(&clip_tbl, &ip, rt->u.dst.dev, 1);
541         ip_rt_put(rt);
542         if (!neigh)
543                 return -ENOMEM;
544         entry = NEIGH2ENTRY(neigh);
545         if (entry != clip_vcc->entry) {
546                 if (!clip_vcc->entry)
547                         pr_debug("setentry: add\n");
548                 else {
549                         pr_debug("setentry: update\n");
550                         unlink_clip_vcc(clip_vcc);
551                 }
552                 link_vcc(clip_vcc, entry);
553         }
554         error = neigh_update(neigh, llc_oui, NUD_PERMANENT,
555                              NEIGH_UPDATE_F_OVERRIDE | NEIGH_UPDATE_F_ADMIN);
556         neigh_release(neigh);
557         return error;
558 }
559
560 static void clip_setup(struct net_device *dev)
561 {
562         dev->hard_start_xmit = clip_start_xmit;
563         /* sg_xmit ... */
564         dev->get_stats = clip_get_stats;
565         dev->type = ARPHRD_ATM;
566         dev->hard_header_len = RFC1483LLC_LEN;
567         dev->mtu = RFC1626_MTU;
568         dev->tx_queue_len = 100;        /* "normal" queue (packets) */
569         /* When using a "real" qdisc, the qdisc determines the queue */
570         /* length. tx_queue_len is only used for the default case, */
571         /* without any more elaborate queuing. 100 is a reasonable */
572         /* compromise between decent burst-tolerance and protection */
573         /* against memory hogs. */
574 }
575
576 static int clip_create(int number)
577 {
578         struct net_device *dev;
579         struct clip_priv *clip_priv;
580         int error;
581
582         if (number != -1) {
583                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
584                         if (PRIV(dev)->number == number)
585                                 return -EEXIST;
586         } else {
587                 number = 0;
588                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
589                         if (PRIV(dev)->number >= number)
590                                 number = PRIV(dev)->number + 1;
591         }
592         dev = alloc_netdev(sizeof(struct clip_priv), "", clip_setup);
593         if (!dev)
594                 return -ENOMEM;
595         clip_priv = PRIV(dev);
596         sprintf(dev->name, "atm%d", number);
597         spin_lock_init(&clip_priv->xoff_lock);
598         clip_priv->number = number;
599         error = register_netdev(dev);
600         if (error) {
601                 free_netdev(dev);
602                 return error;
603         }
604         clip_priv->next = clip_devs;
605         clip_devs = dev;
606         pr_debug("registered (net:%s)\n", dev->name);
607         return number;
608 }
609
610 static int clip_device_event(struct notifier_block *this, unsigned long event,
611                              void *arg)
612 {
613         struct net_device *dev = arg;
614
615         if (dev->nd_net != &init_net)
616                 return NOTIFY_DONE;
617
618         if (event == NETDEV_UNREGISTER) {
619                 neigh_ifdown(&clip_tbl, dev);
620                 return NOTIFY_DONE;
621         }
622
623         /* ignore non-CLIP devices */
624         if (dev->type != ARPHRD_ATM || dev->hard_start_xmit != clip_start_xmit)
625                 return NOTIFY_DONE;
626
627         switch (event) {
628         case NETDEV_UP:
629                 pr_debug("clip_device_event NETDEV_UP\n");
630                 to_atmarpd(act_up, PRIV(dev)->number, 0);
631                 break;
632         case NETDEV_GOING_DOWN:
633                 pr_debug("clip_device_event NETDEV_DOWN\n");
634                 to_atmarpd(act_down, PRIV(dev)->number, 0);
635                 break;
636         case NETDEV_CHANGE:
637         case NETDEV_CHANGEMTU:
638                 pr_debug("clip_device_event NETDEV_CHANGE*\n");
639                 to_atmarpd(act_change, PRIV(dev)->number, 0);
640                 break;
641         }
642         return NOTIFY_DONE;
643 }
644
645 static int clip_inet_event(struct notifier_block *this, unsigned long event,
646                            void *ifa)
647 {
648         struct in_device *in_dev;
649
650         in_dev = ((struct in_ifaddr *)ifa)->ifa_dev;
651         if (!in_dev || !in_dev->dev) {
652                 printk(KERN_WARNING "clip_inet_event: no device\n");
653                 return NOTIFY_DONE;
654         }
655         /*
656          * Transitions are of the down-change-up type, so it's sufficient to
657          * handle the change on up.
658          */
659         if (event != NETDEV_UP)
660                 return NOTIFY_DONE;
661         return clip_device_event(this, NETDEV_CHANGE, in_dev->dev);
662 }
663
664
665 static struct notifier_block clip_dev_notifier = {
666         .notifier_call = clip_device_event,
667 };
668
669
670
671 static struct notifier_block clip_inet_notifier = {
672         .notifier_call = clip_inet_event,
673 };
674
675
676
677 static void atmarpd_close(struct atm_vcc *vcc)
678 {
679         pr_debug("atmarpd_close\n");
680
681         rtnl_lock();
682         atmarpd = NULL;
683         skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
684         rtnl_unlock();
685
686         pr_debug("(done)\n");
687         module_put(THIS_MODULE);
688 }
689
690
691 static struct atmdev_ops atmarpd_dev_ops = {
692         .close = atmarpd_close
693 };
694
695
696 static struct atm_dev atmarpd_dev = {
697         .ops =                  &atmarpd_dev_ops,
698         .type =                 "arpd",
699         .number =               999,
700         .lock =                 __SPIN_LOCK_UNLOCKED(atmarpd_dev.lock)
701 };
702
703
704 static int atm_init_atmarp(struct atm_vcc *vcc)
705 {
706         rtnl_lock();
707         if (atmarpd) {
708                 rtnl_unlock();
709                 return -EADDRINUSE;
710         }
711
712         mod_timer(&idle_timer, jiffies+CLIP_CHECK_INTERVAL*HZ);
713
714         atmarpd = vcc;
715         set_bit(ATM_VF_META,&vcc->flags);
716         set_bit(ATM_VF_READY,&vcc->flags);
717             /* allow replies and avoid getting closed if signaling dies */
718         vcc->dev = &atmarpd_dev;
719         vcc_insert_socket(sk_atm(vcc));
720         vcc->push = NULL;
721         vcc->pop = NULL; /* crash */
722         vcc->push_oam = NULL; /* crash */
723         rtnl_unlock();
724         return 0;
725 }
726
727 static int clip_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
728 {
729         struct atm_vcc *vcc = ATM_SD(sock);
730         int err = 0;
731
732         switch (cmd) {
733         case SIOCMKCLIP:
734         case ATMARPD_CTRL:
735         case ATMARP_MKIP:
736         case ATMARP_SETENTRY:
737         case ATMARP_ENCAP:
738                 if (!capable(CAP_NET_ADMIN))
739                         return -EPERM;
740                 break;
741         default:
742                 return -ENOIOCTLCMD;
743         }
744
745         switch (cmd) {
746         case SIOCMKCLIP:
747                 err = clip_create(arg);
748                 break;
749         case ATMARPD_CTRL:
750                 err = atm_init_atmarp(vcc);
751                 if (!err) {
752                         sock->state = SS_CONNECTED;
753                         __module_get(THIS_MODULE);
754                 }
755                 break;
756         case ATMARP_MKIP:
757                 err = clip_mkip(vcc, arg);
758                 break;
759         case ATMARP_SETENTRY:
760                 err = clip_setentry(vcc, (__force __be32)arg);
761                 break;
762         case ATMARP_ENCAP:
763                 err = clip_encap(vcc, arg);
764                 break;
765         }
766         return err;
767 }
768
769 static struct atm_ioctl clip_ioctl_ops = {
770         .owner = THIS_MODULE,
771         .ioctl = clip_ioctl,
772 };
773
774 #ifdef CONFIG_PROC_FS
775
776 static void svc_addr(struct seq_file *seq, struct sockaddr_atmsvc *addr)
777 {
778         static int code[] = { 1, 2, 10, 6, 1, 0 };
779         static int e164[] = { 1, 8, 4, 6, 1, 0 };
780
781         if (*addr->sas_addr.pub) {
782                 seq_printf(seq, "%s", addr->sas_addr.pub);
783                 if (*addr->sas_addr.prv)
784                         seq_putc(seq, '+');
785         } else if (!*addr->sas_addr.prv) {
786                 seq_printf(seq, "%s", "(none)");
787                 return;
788         }
789         if (*addr->sas_addr.prv) {
790                 unsigned char *prv = addr->sas_addr.prv;
791                 int *fields;
792                 int i, j;
793
794                 fields = *prv == ATM_AFI_E164 ? e164 : code;
795                 for (i = 0; fields[i]; i++) {
796                         for (j = fields[i]; j; j--)
797                                 seq_printf(seq, "%02X", *prv++);
798                         if (fields[i + 1])
799                                 seq_putc(seq, '.');
800                 }
801         }
802 }
803
804 /* This means the neighbour entry has no attached VCC objects. */
805 #define SEQ_NO_VCC_TOKEN        ((void *) 2)
806
807 static void atmarp_info(struct seq_file *seq, struct net_device *dev,
808                         struct atmarp_entry *entry, struct clip_vcc *clip_vcc)
809 {
810         unsigned long exp;
811         char buf[17];
812         int svc, llc, off;
813
814         svc = ((clip_vcc == SEQ_NO_VCC_TOKEN) ||
815                (sk_atm(clip_vcc->vcc)->sk_family == AF_ATMSVC));
816
817         llc = ((clip_vcc == SEQ_NO_VCC_TOKEN) || clip_vcc->encap);
818
819         if (clip_vcc == SEQ_NO_VCC_TOKEN)
820                 exp = entry->neigh->used;
821         else
822                 exp = clip_vcc->last_use;
823
824         exp = (jiffies - exp) / HZ;
825
826         seq_printf(seq, "%-6s%-4s%-4s%5ld ",
827                    dev->name, svc ? "SVC" : "PVC", llc ? "LLC" : "NULL", exp);
828
829         off = scnprintf(buf, sizeof(buf) - 1, "%d.%d.%d.%d",
830                         NIPQUAD(entry->ip));
831         while (off < 16)
832                 buf[off++] = ' ';
833         buf[off] = '\0';
834         seq_printf(seq, "%s", buf);
835
836         if (clip_vcc == SEQ_NO_VCC_TOKEN) {
837                 if (time_before(jiffies, entry->expires))
838                         seq_printf(seq, "(resolving)\n");
839                 else
840                         seq_printf(seq, "(expired, ref %d)\n",
841                                    atomic_read(&entry->neigh->refcnt));
842         } else if (!svc) {
843                 seq_printf(seq, "%d.%d.%d\n",
844                            clip_vcc->vcc->dev->number,
845                            clip_vcc->vcc->vpi, clip_vcc->vcc->vci);
846         } else {
847                 svc_addr(seq, &clip_vcc->vcc->remote);
848                 seq_putc(seq, '\n');
849         }
850 }
851
852 struct clip_seq_state {
853         /* This member must be first. */
854         struct neigh_seq_state ns;
855
856         /* Local to clip specific iteration. */
857         struct clip_vcc *vcc;
858 };
859
860 static struct clip_vcc *clip_seq_next_vcc(struct atmarp_entry *e,
861                                           struct clip_vcc *curr)
862 {
863         if (!curr) {
864                 curr = e->vccs;
865                 if (!curr)
866                         return SEQ_NO_VCC_TOKEN;
867                 return curr;
868         }
869         if (curr == SEQ_NO_VCC_TOKEN)
870                 return NULL;
871
872         curr = curr->next;
873
874         return curr;
875 }
876
877 static void *clip_seq_vcc_walk(struct clip_seq_state *state,
878                                struct atmarp_entry *e, loff_t * pos)
879 {
880         struct clip_vcc *vcc = state->vcc;
881
882         vcc = clip_seq_next_vcc(e, vcc);
883         if (vcc && pos != NULL) {
884                 while (*pos) {
885                         vcc = clip_seq_next_vcc(e, vcc);
886                         if (!vcc)
887                                 break;
888                         --(*pos);
889                 }
890         }
891         state->vcc = vcc;
892
893         return vcc;
894 }
895
896 static void *clip_seq_sub_iter(struct neigh_seq_state *_state,
897                                struct neighbour *n, loff_t * pos)
898 {
899         struct clip_seq_state *state = (struct clip_seq_state *)_state;
900
901         return clip_seq_vcc_walk(state, NEIGH2ENTRY(n), pos);
902 }
903
904 static void *clip_seq_start(struct seq_file *seq, loff_t * pos)
905 {
906         struct clip_seq_state *state = seq->private;
907         state->ns.neigh_sub_iter = clip_seq_sub_iter;
908         return neigh_seq_start(seq, pos, &clip_tbl, NEIGH_SEQ_NEIGH_ONLY);
909 }
910
911 static int clip_seq_show(struct seq_file *seq, void *v)
912 {
913         static char atm_arp_banner[] =
914             "IPitf TypeEncp Idle IP address      ATM address\n";
915
916         if (v == SEQ_START_TOKEN) {
917                 seq_puts(seq, atm_arp_banner);
918         } else {
919                 struct clip_seq_state *state = seq->private;
920                 struct neighbour *n = v;
921                 struct clip_vcc *vcc = state->vcc;
922
923                 atmarp_info(seq, n->dev, NEIGH2ENTRY(n), vcc);
924         }
925         return 0;
926 }
927
928 static const struct seq_operations arp_seq_ops = {
929         .start  = clip_seq_start,
930         .next   = neigh_seq_next,
931         .stop   = neigh_seq_stop,
932         .show   = clip_seq_show,
933 };
934
935 static int arp_seq_open(struct inode *inode, struct file *file)
936 {
937         return seq_open_net(inode, file, &arp_seq_ops,
938                             sizeof(struct clip_seq_state));
939 }
940
941 static const struct file_operations arp_seq_fops = {
942         .open           = arp_seq_open,
943         .read           = seq_read,
944         .llseek         = seq_lseek,
945         .release        = seq_release_net,
946         .owner          = THIS_MODULE
947 };
948 #endif
949
950 static int __init atm_clip_init(void)
951 {
952         neigh_table_init_no_netlink(&clip_tbl);
953
954         clip_tbl_hook = &clip_tbl;
955         register_atm_ioctl(&clip_ioctl_ops);
956         register_netdevice_notifier(&clip_dev_notifier);
957         register_inetaddr_notifier(&clip_inet_notifier);
958
959         setup_timer(&idle_timer, idle_timer_check, 0);
960
961 #ifdef CONFIG_PROC_FS
962         {
963                 struct proc_dir_entry *p;
964
965                 p = create_proc_entry("arp", S_IRUGO, atm_proc_root);
966                 if (p)
967                         p->proc_fops = &arp_seq_fops;
968         }
969 #endif
970
971         return 0;
972 }
973
974 static void __exit atm_clip_exit(void)
975 {
976         struct net_device *dev, *next;
977
978         remove_proc_entry("arp", atm_proc_root);
979
980         unregister_inetaddr_notifier(&clip_inet_notifier);
981         unregister_netdevice_notifier(&clip_dev_notifier);
982
983         deregister_atm_ioctl(&clip_ioctl_ops);
984
985         /* First, stop the idle timer, so it stops banging
986          * on the table.
987          */
988         del_timer_sync(&idle_timer);
989
990         /* Next, purge the table, so that the device
991          * unregister loop below does not hang due to
992          * device references remaining in the table.
993          */
994         neigh_ifdown(&clip_tbl, NULL);
995
996         dev = clip_devs;
997         while (dev) {
998                 next = PRIV(dev)->next;
999                 unregister_netdev(dev);
1000                 free_netdev(dev);
1001                 dev = next;
1002         }
1003
1004         /* Now it is safe to fully shutdown whole table. */
1005         neigh_table_clear(&clip_tbl);
1006
1007         clip_tbl_hook = NULL;
1008 }
1009
1010 module_init(atm_clip_init);
1011 module_exit(atm_clip_exit);
1012 MODULE_AUTHOR("Werner Almesberger");
1013 MODULE_DESCRIPTION("Classical/IP over ATM interface");
1014 MODULE_LICENSE("GPL");