net/atm/atm_sysfs.c: checkpatch cleanups
[linux-2.6.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 #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 <net/route.h> /* for struct rtable and routing */
34 #include <net/icmp.h> /* icmp_send */
35 #include <asm/param.h> /* for HZ */
36 #include <asm/byteorder.h> /* for htons etc. */
37 #include <asm/system.h> /* save/restore_flags */
38 #include <asm/uaccess.h>
39 #include <asm/atomic.h>
40
41 #include "common.h"
42 #include "resources.h"
43 #include <net/atmclip.h>
44
45 static struct net_device *clip_devs;
46 static struct atm_vcc *atmarpd;
47 static struct neigh_table clip_tbl;
48 static struct timer_list idle_timer;
49
50 static int to_atmarpd(enum atmarp_ctrl_type type, int itf, __be32 ip)
51 {
52         struct sock *sk;
53         struct atmarp_ctrl *ctrl;
54         struct sk_buff *skb;
55
56         pr_debug("(%d)\n", type);
57         if (!atmarpd)
58                 return -EUNATCH;
59         skb = alloc_skb(sizeof(struct atmarp_ctrl),GFP_ATOMIC);
60         if (!skb)
61                 return -ENOMEM;
62         ctrl = (struct atmarp_ctrl *) skb_put(skb,sizeof(struct atmarp_ctrl));
63         ctrl->type = type;
64         ctrl->itf_num = itf;
65         ctrl->ip = ip;
66         atm_force_charge(atmarpd, skb->truesize);
67
68         sk = sk_atm(atmarpd);
69         skb_queue_tail(&sk->sk_receive_queue, skb);
70         sk->sk_data_ready(sk, skb->len);
71         return 0;
72 }
73
74 static void link_vcc(struct clip_vcc *clip_vcc, struct atmarp_entry *entry)
75 {
76         pr_debug("%p to entry %p (neigh %p)\n", clip_vcc, entry, entry->neigh);
77         clip_vcc->entry = entry;
78         clip_vcc->xoff = 0;     /* @@@ may overrun buffer by one packet */
79         clip_vcc->next = entry->vccs;
80         entry->vccs = clip_vcc;
81         entry->neigh->used = jiffies;
82 }
83
84 static void unlink_clip_vcc(struct clip_vcc *clip_vcc)
85 {
86         struct atmarp_entry *entry = clip_vcc->entry;
87         struct clip_vcc **walk;
88
89         if (!entry) {
90                 pr_crit("!clip_vcc->entry (clip_vcc %p)\n", clip_vcc);
91                 return;
92         }
93         netif_tx_lock_bh(entry->neigh->dev);    /* block clip_start_xmit() */
94         entry->neigh->used = jiffies;
95         for (walk = &entry->vccs; *walk; walk = &(*walk)->next)
96                 if (*walk == clip_vcc) {
97                         int error;
98
99                         *walk = clip_vcc->next; /* atomic */
100                         clip_vcc->entry = NULL;
101                         if (clip_vcc->xoff)
102                                 netif_wake_queue(entry->neigh->dev);
103                         if (entry->vccs)
104                                 goto out;
105                         entry->expires = jiffies - 1;
106                         /* force resolution or expiration */
107                         error = neigh_update(entry->neigh, NULL, NUD_NONE,
108                                              NEIGH_UPDATE_F_ADMIN);
109                         if (error)
110                                 pr_crit("neigh_update failed with %d\n", error);
111                         goto out;
112                 }
113         pr_crit("ATMARP: failed (entry %p, vcc 0x%p)\n", entry, clip_vcc);
114       out:
115         netif_tx_unlock_bh(entry->neigh->dev);
116 }
117
118 /* The neighbour entry n->lock is held. */
119 static int neigh_check_cb(struct neighbour *n)
120 {
121         struct atmarp_entry *entry = NEIGH2ENTRY(n);
122         struct clip_vcc *cv;
123
124         for (cv = entry->vccs; cv; cv = cv->next) {
125                 unsigned long exp = cv->last_use + cv->idle_timeout;
126
127                 if (cv->idle_timeout && time_after(jiffies, exp)) {
128                         pr_debug("releasing vcc %p->%p of entry %p\n",
129                                  cv, cv->vcc, entry);
130                         vcc_release_async(cv->vcc, -ETIMEDOUT);
131                 }
132         }
133
134         if (entry->vccs || time_before(jiffies, entry->expires))
135                 return 0;
136
137         if (atomic_read(&n->refcnt) > 1) {
138                 struct sk_buff *skb;
139
140                 pr_debug("destruction postponed with ref %d\n",
141                          atomic_read(&n->refcnt));
142
143                 while ((skb = skb_dequeue(&n->arp_queue)) != NULL)
144                         dev_kfree_skb(skb);
145
146                 return 0;
147         }
148
149         pr_debug("expired neigh %p\n", n);
150         return 1;
151 }
152
153 static void idle_timer_check(unsigned long dummy)
154 {
155         write_lock(&clip_tbl.lock);
156         __neigh_for_each_release(&clip_tbl, neigh_check_cb);
157         mod_timer(&idle_timer, jiffies + CLIP_CHECK_INTERVAL * HZ);
158         write_unlock(&clip_tbl.lock);
159 }
160
161 static int clip_arp_rcv(struct sk_buff *skb)
162 {
163         struct atm_vcc *vcc;
164
165         pr_debug("\n");
166         vcc = ATM_SKB(skb)->vcc;
167         if (!vcc || !atm_charge(vcc, skb->truesize)) {
168                 dev_kfree_skb_any(skb);
169                 return 0;
170         }
171         pr_debug("pushing to %p\n", vcc);
172         pr_debug("using %p\n", CLIP_VCC(vcc)->old_push);
173         CLIP_VCC(vcc)->old_push(vcc, skb);
174         return 0;
175 }
176
177 static const unsigned char llc_oui[] = {
178         0xaa,   /* DSAP: non-ISO */
179         0xaa,   /* SSAP: non-ISO */
180         0x03,   /* Ctrl: Unnumbered Information Command PDU */
181         0x00,   /* OUI: EtherType */
182         0x00,
183         0x00
184 };
185
186 static void clip_push(struct atm_vcc *vcc, struct sk_buff *skb)
187 {
188         struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
189
190         pr_debug("\n");
191         if (!skb) {
192                 pr_debug("removing VCC %p\n", clip_vcc);
193                 if (clip_vcc->entry)
194                         unlink_clip_vcc(clip_vcc);
195                 clip_vcc->old_push(vcc, NULL);  /* pass on the bad news */
196                 kfree(clip_vcc);
197                 return;
198         }
199         atm_return(vcc, skb->truesize);
200         skb->dev = clip_vcc->entry ? clip_vcc->entry->neigh->dev : clip_devs;
201         /* clip_vcc->entry == NULL if we don't have an IP address yet */
202         if (!skb->dev) {
203                 dev_kfree_skb_any(skb);
204                 return;
205         }
206         ATM_SKB(skb)->vcc = vcc;
207         skb_reset_mac_header(skb);
208         if (!clip_vcc->encap
209             || skb->len < RFC1483LLC_LEN
210             || memcmp(skb->data, llc_oui, sizeof (llc_oui)))
211                 skb->protocol = htons(ETH_P_IP);
212         else {
213                 skb->protocol = ((__be16 *) skb->data)[3];
214                 skb_pull(skb, RFC1483LLC_LEN);
215                 if (skb->protocol == htons(ETH_P_ARP)) {
216                         skb->dev->stats.rx_packets++;
217                         skb->dev->stats.rx_bytes += skb->len;
218                         clip_arp_rcv(skb);
219                         return;
220                 }
221         }
222         clip_vcc->last_use = jiffies;
223         skb->dev->stats.rx_packets++;
224         skb->dev->stats.rx_bytes += skb->len;
225         memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
226         netif_rx(skb);
227 }
228
229 /*
230  * Note: these spinlocks _must_not_ block on non-SMP. The only goal is that
231  * clip_pop is atomic with respect to the critical section in clip_start_xmit.
232  */
233
234 static void clip_pop(struct atm_vcc *vcc, struct sk_buff *skb)
235 {
236         struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
237         struct net_device *dev = skb->dev;
238         int old;
239         unsigned long flags;
240
241         pr_debug("(vcc %p)\n", vcc);
242         clip_vcc->old_pop(vcc, skb);
243         /* skb->dev == NULL in outbound ARP packets */
244         if (!dev)
245                 return;
246         spin_lock_irqsave(&PRIV(dev)->xoff_lock, flags);
247         if (atm_may_send(vcc, 0)) {
248                 old = xchg(&clip_vcc->xoff, 0);
249                 if (old)
250                         netif_wake_queue(dev);
251         }
252         spin_unlock_irqrestore(&PRIV(dev)->xoff_lock, flags);
253 }
254
255 static void clip_neigh_solicit(struct neighbour *neigh, struct sk_buff *skb)
256 {
257         pr_debug("(neigh %p, skb %p)\n", neigh, skb);
258         to_atmarpd(act_need, PRIV(neigh->dev)->number, NEIGH2ENTRY(neigh)->ip);
259 }
260
261 static void clip_neigh_error(struct neighbour *neigh, struct sk_buff *skb)
262 {
263 #ifndef CONFIG_ATM_CLIP_NO_ICMP
264         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
265 #endif
266         kfree_skb(skb);
267 }
268
269 static const struct neigh_ops clip_neigh_ops = {
270         .family =               AF_INET,
271         .solicit =              clip_neigh_solicit,
272         .error_report =         clip_neigh_error,
273         .output =               dev_queue_xmit,
274         .connected_output =     dev_queue_xmit,
275         .hh_output =            dev_queue_xmit,
276         .queue_xmit =           dev_queue_xmit,
277 };
278
279 static int clip_constructor(struct neighbour *neigh)
280 {
281         struct atmarp_entry *entry = NEIGH2ENTRY(neigh);
282         struct net_device *dev = neigh->dev;
283         struct in_device *in_dev;
284         struct neigh_parms *parms;
285
286         pr_debug("(neigh %p, entry %p)\n", neigh, entry);
287         neigh->type = inet_addr_type(&init_net, entry->ip);
288         if (neigh->type != RTN_UNICAST)
289                 return -EINVAL;
290
291         rcu_read_lock();
292         in_dev = __in_dev_get_rcu(dev);
293         if (!in_dev) {
294                 rcu_read_unlock();
295                 return -EINVAL;
296         }
297
298         parms = in_dev->arp_parms;
299         __neigh_parms_put(neigh->parms);
300         neigh->parms = neigh_parms_clone(parms);
301         rcu_read_unlock();
302
303         neigh->ops = &clip_neigh_ops;
304         neigh->output = neigh->nud_state & NUD_VALID ?
305             neigh->ops->connected_output : neigh->ops->output;
306         entry->neigh = neigh;
307         entry->vccs = NULL;
308         entry->expires = jiffies - 1;
309         return 0;
310 }
311
312 static u32 clip_hash(const void *pkey, const struct net_device *dev)
313 {
314         return jhash_2words(*(u32 *) pkey, dev->ifindex, clip_tbl.hash_rnd);
315 }
316
317 static struct neigh_table clip_tbl = {
318         .family         = AF_INET,
319         .entry_size     = sizeof(struct neighbour)+sizeof(struct atmarp_entry),
320         .key_len        = 4,
321         .hash           = clip_hash,
322         .constructor    = clip_constructor,
323         .id             = "clip_arp_cache",
324
325         /* parameters are copied from ARP ... */
326         .parms = {
327                 .tbl                    = &clip_tbl,
328                 .base_reachable_time    = 30 * HZ,
329                 .retrans_time           = 1 * HZ,
330                 .gc_staletime           = 60 * HZ,
331                 .reachable_time         = 30 * HZ,
332                 .delay_probe_time       = 5 * HZ,
333                 .queue_len              = 3,
334                 .ucast_probes           = 3,
335                 .mcast_probes           = 3,
336                 .anycast_delay          = 1 * HZ,
337                 .proxy_delay            = (8 * HZ) / 10,
338                 .proxy_qlen             = 64,
339                 .locktime               = 1 * HZ,
340         },
341         .gc_interval    = 30 * HZ,
342         .gc_thresh1     = 128,
343         .gc_thresh2     = 512,
344         .gc_thresh3     = 1024,
345 };
346
347 /* @@@ copy bh locking from arp.c -- need to bh-enable atm code before */
348
349 /*
350  * We play with the resolve flag: 0 and 1 have the usual meaning, but -1 means
351  * to allocate the neighbour entry but not to ask atmarpd for resolution. Also,
352  * don't increment the usage count. This is used to create entries in
353  * clip_setentry.
354  */
355
356 static int clip_encap(struct atm_vcc *vcc, int mode)
357 {
358         CLIP_VCC(vcc)->encap = mode;
359         return 0;
360 }
361
362 static netdev_tx_t clip_start_xmit(struct sk_buff *skb,
363                                    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("(skb %p)\n", skb);
372         if (!skb_dst(skb)) {
373                 pr_err("skb_dst(skb) == NULL\n");
374                 dev_kfree_skb(skb);
375                 dev->stats.tx_dropped++;
376                 return NETDEV_TX_OK;
377         }
378         if (!skb_dst(skb)->neighbour) {
379 #if 0
380                 skb_dst(skb)->neighbour = clip_find_neighbour(skb_dst(skb), 1);
381                 if (!skb_dst(skb)->neighbour) {
382                         dev_kfree_skb(skb);     /* lost that one */
383                         dev->stats.tx_dropped++;
384                         return 0;
385                 }
386 #endif
387                 pr_err("NO NEIGHBOUR !\n");
388                 dev_kfree_skb(skb);
389                 dev->stats.tx_dropped++;
390                 return NETDEV_TX_OK;
391         }
392         entry = NEIGH2ENTRY(skb_dst(skb)->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                         dev->stats.tx_dropped++;
404                 }
405                 return NETDEV_TX_OK;
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(skb)->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                 pr_warning("XOFF->XOFF transition\n");
424                 return NETDEV_TX_OK;
425         }
426         dev->stats.tx_packets++;
427         dev->stats.tx_bytes += skb->len;
428         vcc->send(vcc, skb);
429         if (atm_may_send(vcc, 0)) {
430                 entry->vccs->xoff = 0;
431                 return NETDEV_TX_OK;
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 NETDEV_TX_OK;
444 }
445
446 static int clip_mkip(struct atm_vcc *vcc, int timeout)
447 {
448         struct sk_buff_head *rq, queue;
449         struct clip_vcc *clip_vcc;
450         struct sk_buff *skb, *tmp;
451         unsigned long flags;
452
453         if (!vcc->push)
454                 return -EBADFD;
455         clip_vcc = kmalloc(sizeof(struct clip_vcc), GFP_KERNEL);
456         if (!clip_vcc)
457                 return -ENOMEM;
458         pr_debug("%p vcc %p\n", clip_vcc, vcc);
459         clip_vcc->vcc = vcc;
460         vcc->user_back = clip_vcc;
461         set_bit(ATM_VF_IS_CLIP, &vcc->flags);
462         clip_vcc->entry = NULL;
463         clip_vcc->xoff = 0;
464         clip_vcc->encap = 1;
465         clip_vcc->last_use = jiffies;
466         clip_vcc->idle_timeout = timeout * HZ;
467         clip_vcc->old_push = vcc->push;
468         clip_vcc->old_pop = vcc->pop;
469         vcc->push = clip_push;
470         vcc->pop = clip_pop;
471
472         __skb_queue_head_init(&queue);
473         rq = &sk_atm(vcc)->sk_receive_queue;
474
475         spin_lock_irqsave(&rq->lock, flags);
476         skb_queue_splice_init(rq, &queue);
477         spin_unlock_irqrestore(&rq->lock, flags);
478
479         /* re-process everything received between connection setup and MKIP */
480         skb_queue_walk_safe(&queue, skb, tmp) {
481                 if (!clip_devs) {
482                         atm_return(vcc, skb->truesize);
483                         kfree_skb(skb);
484                 } else {
485                         struct net_device *dev = skb->dev;
486                         unsigned int len = skb->len;
487
488                         skb_get(skb);
489                         clip_push(vcc, skb);
490                         dev->stats.rx_packets--;
491                         dev->stats.rx_bytes -= len;
492                         kfree_skb(skb);
493                 }
494         }
495         return 0;
496 }
497
498 static int clip_setentry(struct atm_vcc *vcc, __be32 ip)
499 {
500         struct neighbour *neigh;
501         struct atmarp_entry *entry;
502         int error;
503         struct clip_vcc *clip_vcc;
504         struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, .tos = 1}} };
505         struct rtable *rt;
506
507         if (vcc->push != clip_push) {
508                 pr_warning("non-CLIP VCC\n");
509                 return -EBADF;
510         }
511         clip_vcc = CLIP_VCC(vcc);
512         if (!ip) {
513                 if (!clip_vcc->entry) {
514                         pr_err("hiding hidden ATMARP entry\n");
515                         return 0;
516                 }
517                 pr_debug("remove\n");
518                 unlink_clip_vcc(clip_vcc);
519                 return 0;
520         }
521         error = ip_route_output_key(&init_net, &rt, &fl);
522         if (error)
523                 return error;
524         neigh = __neigh_lookup(&clip_tbl, &ip, rt->u.dst.dev, 1);
525         ip_rt_put(rt);
526         if (!neigh)
527                 return -ENOMEM;
528         entry = NEIGH2ENTRY(neigh);
529         if (entry != clip_vcc->entry) {
530                 if (!clip_vcc->entry)
531                         pr_debug("add\n");
532                 else {
533                         pr_debug("update\n");
534                         unlink_clip_vcc(clip_vcc);
535                 }
536                 link_vcc(clip_vcc, entry);
537         }
538         error = neigh_update(neigh, llc_oui, NUD_PERMANENT,
539                              NEIGH_UPDATE_F_OVERRIDE | NEIGH_UPDATE_F_ADMIN);
540         neigh_release(neigh);
541         return error;
542 }
543
544 static const struct net_device_ops clip_netdev_ops = {
545         .ndo_start_xmit = clip_start_xmit,
546 };
547
548 static void clip_setup(struct net_device *dev)
549 {
550         dev->netdev_ops = &clip_netdev_ops;
551         dev->type = ARPHRD_ATM;
552         dev->hard_header_len = RFC1483LLC_LEN;
553         dev->mtu = RFC1626_MTU;
554         dev->tx_queue_len = 100;        /* "normal" queue (packets) */
555         /* When using a "real" qdisc, the qdisc determines the queue */
556         /* length. tx_queue_len is only used for the default case, */
557         /* without any more elaborate queuing. 100 is a reasonable */
558         /* compromise between decent burst-tolerance and protection */
559         /* against memory hogs. */
560         dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
561 }
562
563 static int clip_create(int number)
564 {
565         struct net_device *dev;
566         struct clip_priv *clip_priv;
567         int error;
568
569         if (number != -1) {
570                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
571                         if (PRIV(dev)->number == number)
572                                 return -EEXIST;
573         } else {
574                 number = 0;
575                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
576                         if (PRIV(dev)->number >= number)
577                                 number = PRIV(dev)->number + 1;
578         }
579         dev = alloc_netdev(sizeof(struct clip_priv), "", clip_setup);
580         if (!dev)
581                 return -ENOMEM;
582         clip_priv = PRIV(dev);
583         sprintf(dev->name, "atm%d", number);
584         spin_lock_init(&clip_priv->xoff_lock);
585         clip_priv->number = number;
586         error = register_netdev(dev);
587         if (error) {
588                 free_netdev(dev);
589                 return error;
590         }
591         clip_priv->next = clip_devs;
592         clip_devs = dev;
593         pr_debug("registered (net:%s)\n", dev->name);
594         return number;
595 }
596
597 static int clip_device_event(struct notifier_block *this, unsigned long event,
598                              void *arg)
599 {
600         struct net_device *dev = arg;
601
602         if (!net_eq(dev_net(dev), &init_net))
603                 return NOTIFY_DONE;
604
605         if (event == NETDEV_UNREGISTER) {
606                 neigh_ifdown(&clip_tbl, dev);
607                 return NOTIFY_DONE;
608         }
609
610         /* ignore non-CLIP devices */
611         if (dev->type != ARPHRD_ATM || dev->netdev_ops != &clip_netdev_ops)
612                 return NOTIFY_DONE;
613
614         switch (event) {
615         case NETDEV_UP:
616                 pr_debug("NETDEV_UP\n");
617                 to_atmarpd(act_up, PRIV(dev)->number, 0);
618                 break;
619         case NETDEV_GOING_DOWN:
620                 pr_debug("NETDEV_DOWN\n");
621                 to_atmarpd(act_down, PRIV(dev)->number, 0);
622                 break;
623         case NETDEV_CHANGE:
624         case NETDEV_CHANGEMTU:
625                 pr_debug("NETDEV_CHANGE*\n");
626                 to_atmarpd(act_change, PRIV(dev)->number, 0);
627                 break;
628         }
629         return NOTIFY_DONE;
630 }
631
632 static int clip_inet_event(struct notifier_block *this, unsigned long event,
633                            void *ifa)
634 {
635         struct in_device *in_dev;
636
637         in_dev = ((struct in_ifaddr *)ifa)->ifa_dev;
638         /*
639          * Transitions are of the down-change-up type, so it's sufficient to
640          * handle the change on up.
641          */
642         if (event != NETDEV_UP)
643                 return NOTIFY_DONE;
644         return clip_device_event(this, NETDEV_CHANGE, in_dev->dev);
645 }
646
647
648 static struct notifier_block clip_dev_notifier = {
649         .notifier_call = clip_device_event,
650 };
651
652
653
654 static struct notifier_block clip_inet_notifier = {
655         .notifier_call = clip_inet_event,
656 };
657
658
659
660 static void atmarpd_close(struct atm_vcc *vcc)
661 {
662         pr_debug("\n");
663
664         rtnl_lock();
665         atmarpd = NULL;
666         skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
667         rtnl_unlock();
668
669         pr_debug("(done)\n");
670         module_put(THIS_MODULE);
671 }
672
673
674 static struct atmdev_ops atmarpd_dev_ops = {
675         .close = atmarpd_close
676 };
677
678
679 static struct atm_dev atmarpd_dev = {
680         .ops =                  &atmarpd_dev_ops,
681         .type =                 "arpd",
682         .number =               999,
683         .lock =                 __SPIN_LOCK_UNLOCKED(atmarpd_dev.lock)
684 };
685
686
687 static int atm_init_atmarp(struct atm_vcc *vcc)
688 {
689         rtnl_lock();
690         if (atmarpd) {
691                 rtnl_unlock();
692                 return -EADDRINUSE;
693         }
694
695         mod_timer(&idle_timer, jiffies+CLIP_CHECK_INTERVAL*HZ);
696
697         atmarpd = vcc;
698         set_bit(ATM_VF_META,&vcc->flags);
699         set_bit(ATM_VF_READY,&vcc->flags);
700             /* allow replies and avoid getting closed if signaling dies */
701         vcc->dev = &atmarpd_dev;
702         vcc_insert_socket(sk_atm(vcc));
703         vcc->push = NULL;
704         vcc->pop = NULL; /* crash */
705         vcc->push_oam = NULL; /* crash */
706         rtnl_unlock();
707         return 0;
708 }
709
710 static int clip_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
711 {
712         struct atm_vcc *vcc = ATM_SD(sock);
713         int err = 0;
714
715         switch (cmd) {
716         case SIOCMKCLIP:
717         case ATMARPD_CTRL:
718         case ATMARP_MKIP:
719         case ATMARP_SETENTRY:
720         case ATMARP_ENCAP:
721                 if (!capable(CAP_NET_ADMIN))
722                         return -EPERM;
723                 break;
724         default:
725                 return -ENOIOCTLCMD;
726         }
727
728         switch (cmd) {
729         case SIOCMKCLIP:
730                 err = clip_create(arg);
731                 break;
732         case ATMARPD_CTRL:
733                 err = atm_init_atmarp(vcc);
734                 if (!err) {
735                         sock->state = SS_CONNECTED;
736                         __module_get(THIS_MODULE);
737                 }
738                 break;
739         case ATMARP_MKIP:
740                 err = clip_mkip(vcc, arg);
741                 break;
742         case ATMARP_SETENTRY:
743                 err = clip_setentry(vcc, (__force __be32)arg);
744                 break;
745         case ATMARP_ENCAP:
746                 err = clip_encap(vcc, arg);
747                 break;
748         }
749         return err;
750 }
751
752 static struct atm_ioctl clip_ioctl_ops = {
753         .owner = THIS_MODULE,
754         .ioctl = clip_ioctl,
755 };
756
757 #ifdef CONFIG_PROC_FS
758
759 static void svc_addr(struct seq_file *seq, struct sockaddr_atmsvc *addr)
760 {
761         static int code[] = { 1, 2, 10, 6, 1, 0 };
762         static int e164[] = { 1, 8, 4, 6, 1, 0 };
763
764         if (*addr->sas_addr.pub) {
765                 seq_printf(seq, "%s", addr->sas_addr.pub);
766                 if (*addr->sas_addr.prv)
767                         seq_putc(seq, '+');
768         } else if (!*addr->sas_addr.prv) {
769                 seq_printf(seq, "%s", "(none)");
770                 return;
771         }
772         if (*addr->sas_addr.prv) {
773                 unsigned char *prv = addr->sas_addr.prv;
774                 int *fields;
775                 int i, j;
776
777                 fields = *prv == ATM_AFI_E164 ? e164 : code;
778                 for (i = 0; fields[i]; i++) {
779                         for (j = fields[i]; j; j--)
780                                 seq_printf(seq, "%02X", *prv++);
781                         if (fields[i + 1])
782                                 seq_putc(seq, '.');
783                 }
784         }
785 }
786
787 /* This means the neighbour entry has no attached VCC objects. */
788 #define SEQ_NO_VCC_TOKEN        ((void *) 2)
789
790 static void atmarp_info(struct seq_file *seq, struct net_device *dev,
791                         struct atmarp_entry *entry, struct clip_vcc *clip_vcc)
792 {
793         unsigned long exp;
794         char buf[17];
795         int svc, llc, off;
796
797         svc = ((clip_vcc == SEQ_NO_VCC_TOKEN) ||
798                (sk_atm(clip_vcc->vcc)->sk_family == AF_ATMSVC));
799
800         llc = ((clip_vcc == SEQ_NO_VCC_TOKEN) || clip_vcc->encap);
801
802         if (clip_vcc == SEQ_NO_VCC_TOKEN)
803                 exp = entry->neigh->used;
804         else
805                 exp = clip_vcc->last_use;
806
807         exp = (jiffies - exp) / HZ;
808
809         seq_printf(seq, "%-6s%-4s%-4s%5ld ",
810                    dev->name, svc ? "SVC" : "PVC", llc ? "LLC" : "NULL", exp);
811
812         off = scnprintf(buf, sizeof(buf) - 1, "%pI4",
813                         &entry->ip);
814         while (off < 16)
815                 buf[off++] = ' ';
816         buf[off] = '\0';
817         seq_printf(seq, "%s", buf);
818
819         if (clip_vcc == SEQ_NO_VCC_TOKEN) {
820                 if (time_before(jiffies, entry->expires))
821                         seq_printf(seq, "(resolving)\n");
822                 else
823                         seq_printf(seq, "(expired, ref %d)\n",
824                                    atomic_read(&entry->neigh->refcnt));
825         } else if (!svc) {
826                 seq_printf(seq, "%d.%d.%d\n",
827                            clip_vcc->vcc->dev->number,
828                            clip_vcc->vcc->vpi, clip_vcc->vcc->vci);
829         } else {
830                 svc_addr(seq, &clip_vcc->vcc->remote);
831                 seq_putc(seq, '\n');
832         }
833 }
834
835 struct clip_seq_state {
836         /* This member must be first. */
837         struct neigh_seq_state ns;
838
839         /* Local to clip specific iteration. */
840         struct clip_vcc *vcc;
841 };
842
843 static struct clip_vcc *clip_seq_next_vcc(struct atmarp_entry *e,
844                                           struct clip_vcc *curr)
845 {
846         if (!curr) {
847                 curr = e->vccs;
848                 if (!curr)
849                         return SEQ_NO_VCC_TOKEN;
850                 return curr;
851         }
852         if (curr == SEQ_NO_VCC_TOKEN)
853                 return NULL;
854
855         curr = curr->next;
856
857         return curr;
858 }
859
860 static void *clip_seq_vcc_walk(struct clip_seq_state *state,
861                                struct atmarp_entry *e, loff_t * pos)
862 {
863         struct clip_vcc *vcc = state->vcc;
864
865         vcc = clip_seq_next_vcc(e, vcc);
866         if (vcc && pos != NULL) {
867                 while (*pos) {
868                         vcc = clip_seq_next_vcc(e, vcc);
869                         if (!vcc)
870                                 break;
871                         --(*pos);
872                 }
873         }
874         state->vcc = vcc;
875
876         return vcc;
877 }
878
879 static void *clip_seq_sub_iter(struct neigh_seq_state *_state,
880                                struct neighbour *n, loff_t * pos)
881 {
882         struct clip_seq_state *state = (struct clip_seq_state *)_state;
883
884         return clip_seq_vcc_walk(state, NEIGH2ENTRY(n), pos);
885 }
886
887 static void *clip_seq_start(struct seq_file *seq, loff_t * pos)
888 {
889         struct clip_seq_state *state = seq->private;
890         state->ns.neigh_sub_iter = clip_seq_sub_iter;
891         return neigh_seq_start(seq, pos, &clip_tbl, NEIGH_SEQ_NEIGH_ONLY);
892 }
893
894 static int clip_seq_show(struct seq_file *seq, void *v)
895 {
896         static char atm_arp_banner[] =
897             "IPitf TypeEncp Idle IP address      ATM address\n";
898
899         if (v == SEQ_START_TOKEN) {
900                 seq_puts(seq, atm_arp_banner);
901         } else {
902                 struct clip_seq_state *state = seq->private;
903                 struct neighbour *n = v;
904                 struct clip_vcc *vcc = state->vcc;
905
906                 atmarp_info(seq, n->dev, NEIGH2ENTRY(n), vcc);
907         }
908         return 0;
909 }
910
911 static const struct seq_operations arp_seq_ops = {
912         .start  = clip_seq_start,
913         .next   = neigh_seq_next,
914         .stop   = neigh_seq_stop,
915         .show   = clip_seq_show,
916 };
917
918 static int arp_seq_open(struct inode *inode, struct file *file)
919 {
920         return seq_open_net(inode, file, &arp_seq_ops,
921                             sizeof(struct clip_seq_state));
922 }
923
924 static const struct file_operations arp_seq_fops = {
925         .open           = arp_seq_open,
926         .read           = seq_read,
927         .llseek         = seq_lseek,
928         .release        = seq_release_net,
929         .owner          = THIS_MODULE
930 };
931 #endif
932
933 static void atm_clip_exit_noproc(void);
934
935 static int __init atm_clip_init(void)
936 {
937         neigh_table_init_no_netlink(&clip_tbl);
938
939         clip_tbl_hook = &clip_tbl;
940         register_atm_ioctl(&clip_ioctl_ops);
941         register_netdevice_notifier(&clip_dev_notifier);
942         register_inetaddr_notifier(&clip_inet_notifier);
943
944         setup_timer(&idle_timer, idle_timer_check, 0);
945
946 #ifdef CONFIG_PROC_FS
947         {
948                 struct proc_dir_entry *p;
949
950                 p = proc_create("arp", S_IRUGO, atm_proc_root, &arp_seq_fops);
951                 if (!p) {
952                         pr_err("Unable to initialize /proc/net/atm/arp\n");
953                         atm_clip_exit_noproc();
954                         return -ENOMEM;
955                 }
956         }
957 #endif
958
959         return 0;
960 }
961
962 static void atm_clip_exit_noproc(void)
963 {
964         struct net_device *dev, *next;
965
966         unregister_inetaddr_notifier(&clip_inet_notifier);
967         unregister_netdevice_notifier(&clip_dev_notifier);
968
969         deregister_atm_ioctl(&clip_ioctl_ops);
970
971         /* First, stop the idle timer, so it stops banging
972          * on the table.
973          */
974         del_timer_sync(&idle_timer);
975
976         /* Next, purge the table, so that the device
977          * unregister loop below does not hang due to
978          * device references remaining in the table.
979          */
980         neigh_ifdown(&clip_tbl, NULL);
981
982         dev = clip_devs;
983         while (dev) {
984                 next = PRIV(dev)->next;
985                 unregister_netdev(dev);
986                 free_netdev(dev);
987                 dev = next;
988         }
989
990         /* Now it is safe to fully shutdown whole table. */
991         neigh_table_clear(&clip_tbl);
992
993         clip_tbl_hook = NULL;
994 }
995
996 static void __exit atm_clip_exit(void)
997 {
998         remove_proc_entry("arp", atm_proc_root);
999
1000         atm_clip_exit_noproc();
1001 }
1002
1003 module_init(atm_clip_init);
1004 module_exit(atm_clip_exit);
1005 MODULE_AUTHOR("Werner Almesberger");
1006 MODULE_DESCRIPTION("Classical/IP over ATM interface");
1007 MODULE_LICENSE("GPL");