Pull cpu-hotplug into release branch
[linux-2.6] / 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/config.h>
6 #include <linux/string.h>
7 #include <linux/errno.h>
8 #include <linux/kernel.h> /* for UINT_MAX */
9 #include <linux/module.h>
10 #include <linux/init.h>
11 #include <linux/netdevice.h>
12 #include <linux/skbuff.h>
13 #include <linux/wait.h>
14 #include <linux/timer.h>
15 #include <linux/if_arp.h> /* for some manifest constants */
16 #include <linux/notifier.h>
17 #include <linux/atm.h>
18 #include <linux/atmdev.h>
19 #include <linux/atmclip.h>
20 #include <linux/atmarp.h>
21 #include <linux/capability.h>
22 #include <linux/ip.h> /* for net/route.h */
23 #include <linux/in.h> /* for struct sockaddr_in */
24 #include <linux/if.h> /* for IFF_UP */
25 #include <linux/inetdevice.h>
26 #include <linux/bitops.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 "ipcommon.h"
42 #include <net/atmclip.h>
43
44
45 #if 0
46 #define DPRINTK(format,args...) printk(format,##args)
47 #else
48 #define DPRINTK(format,args...)
49 #endif
50
51
52 static struct net_device *clip_devs;
53 static struct atm_vcc *atmarpd;
54 static struct neigh_table clip_tbl;
55 static struct timer_list idle_timer;
56
57 static int to_atmarpd(enum atmarp_ctrl_type type, int itf, unsigned long ip)
58 {
59         struct sock *sk;
60         struct atmarp_ctrl *ctrl;
61         struct sk_buff *skb;
62
63         DPRINTK("to_atmarpd(%d)\n", type);
64         if (!atmarpd)
65                 return -EUNATCH;
66         skb = alloc_skb(sizeof(struct atmarp_ctrl),GFP_ATOMIC);
67         if (!skb)
68                 return -ENOMEM;
69         ctrl = (struct atmarp_ctrl *) skb_put(skb,sizeof(struct atmarp_ctrl));
70         ctrl->type = type;
71         ctrl->itf_num = itf;
72         ctrl->ip = ip;
73         atm_force_charge(atmarpd, skb->truesize);
74
75         sk = sk_atm(atmarpd);
76         skb_queue_tail(&sk->sk_receive_queue, skb);
77         sk->sk_data_ready(sk, skb->len);
78         return 0;
79 }
80
81 static void link_vcc(struct clip_vcc *clip_vcc, struct atmarp_entry *entry)
82 {
83         DPRINTK("link_vcc %p to entry %p (neigh %p)\n", clip_vcc, entry,
84                 entry->neigh);
85         clip_vcc->entry = entry;
86         clip_vcc->xoff = 0;     /* @@@ may overrun buffer by one packet */
87         clip_vcc->next = entry->vccs;
88         entry->vccs = clip_vcc;
89         entry->neigh->used = jiffies;
90 }
91
92 static void unlink_clip_vcc(struct clip_vcc *clip_vcc)
93 {
94         struct atmarp_entry *entry = clip_vcc->entry;
95         struct clip_vcc **walk;
96
97         if (!entry) {
98                 printk(KERN_CRIT "!clip_vcc->entry (clip_vcc %p)\n", clip_vcc);
99                 return;
100         }
101         spin_lock_bh(&entry->neigh->dev->xmit_lock);    /* block clip_start_xmit() */
102         entry->neigh->used = jiffies;
103         for (walk = &entry->vccs; *walk; walk = &(*walk)->next)
104                 if (*walk == clip_vcc) {
105                         int error;
106
107                         *walk = clip_vcc->next; /* atomic */
108                         clip_vcc->entry = NULL;
109                         if (clip_vcc->xoff)
110                                 netif_wake_queue(entry->neigh->dev);
111                         if (entry->vccs)
112                                 goto out;
113                         entry->expires = jiffies - 1;
114                         /* force resolution or expiration */
115                         error = neigh_update(entry->neigh, NULL, NUD_NONE,
116                                              NEIGH_UPDATE_F_ADMIN);
117                         if (error)
118                                 printk(KERN_CRIT "unlink_clip_vcc: "
119                                        "neigh_update failed with %d\n", error);
120                         goto out;
121                 }
122         printk(KERN_CRIT "ATMARP: unlink_clip_vcc failed (entry %p, vcc "
123                "0x%p)\n", entry, clip_vcc);
124       out:
125         spin_unlock_bh(&entry->neigh->dev->xmit_lock);
126 }
127
128 /* The neighbour entry n->lock is held. */
129 static int neigh_check_cb(struct neighbour *n)
130 {
131         struct atmarp_entry *entry = NEIGH2ENTRY(n);
132         struct clip_vcc *cv;
133
134         for (cv = entry->vccs; cv; cv = cv->next) {
135                 unsigned long exp = cv->last_use + cv->idle_timeout;
136
137                 if (cv->idle_timeout && time_after(jiffies, exp)) {
138                         DPRINTK("releasing vcc %p->%p of entry %p\n",
139                                 cv, cv->vcc, entry);
140                         vcc_release_async(cv->vcc, -ETIMEDOUT);
141                 }
142         }
143
144         if (entry->vccs || time_before(jiffies, entry->expires))
145                 return 0;
146
147         if (atomic_read(&n->refcnt) > 1) {
148                 struct sk_buff *skb;
149
150                 DPRINTK("destruction postponed with ref %d\n",
151                         atomic_read(&n->refcnt));
152
153                 while ((skb = skb_dequeue(&n->arp_queue)) != NULL)
154                         dev_kfree_skb(skb);
155
156                 return 0;
157         }
158
159         DPRINTK("expired neigh %p\n", n);
160         return 1;
161 }
162
163 static void idle_timer_check(unsigned long dummy)
164 {
165         write_lock(&clip_tbl.lock);
166         __neigh_for_each_release(&clip_tbl, neigh_check_cb);
167         mod_timer(&idle_timer, jiffies + CLIP_CHECK_INTERVAL * HZ);
168         write_unlock(&clip_tbl.lock);
169 }
170
171 static int clip_arp_rcv(struct sk_buff *skb)
172 {
173         struct atm_vcc *vcc;
174
175         DPRINTK("clip_arp_rcv\n");
176         vcc = ATM_SKB(skb)->vcc;
177         if (!vcc || !atm_charge(vcc, skb->truesize)) {
178                 dev_kfree_skb_any(skb);
179                 return 0;
180         }
181         DPRINTK("pushing to %p\n", vcc);
182         DPRINTK("using %p\n", CLIP_VCC(vcc)->old_push);
183         CLIP_VCC(vcc)->old_push(vcc, skb);
184         return 0;
185 }
186
187 static const unsigned char llc_oui[] = {
188         0xaa,   /* DSAP: non-ISO */
189         0xaa,   /* SSAP: non-ISO */
190         0x03,   /* Ctrl: Unnumbered Information Command PDU */
191         0x00,   /* OUI: EtherType */
192         0x00,
193         0x00
194 };
195
196 static void clip_push(struct atm_vcc *vcc, struct sk_buff *skb)
197 {
198         struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
199
200         DPRINTK("clip push\n");
201         if (!skb) {
202                 DPRINTK("removing VCC %p\n", clip_vcc);
203                 if (clip_vcc->entry)
204                         unlink_clip_vcc(clip_vcc);
205                 clip_vcc->old_push(vcc, NULL);  /* pass on the bad news */
206                 kfree(clip_vcc);
207                 return;
208         }
209         atm_return(vcc, skb->truesize);
210         skb->dev = clip_vcc->entry ? clip_vcc->entry->neigh->dev : clip_devs;
211         /* clip_vcc->entry == NULL if we don't have an IP address yet */
212         if (!skb->dev) {
213                 dev_kfree_skb_any(skb);
214                 return;
215         }
216         ATM_SKB(skb)->vcc = vcc;
217         skb->mac.raw = skb->data;
218         if (!clip_vcc->encap
219             || skb->len < RFC1483LLC_LEN
220             || memcmp(skb->data, llc_oui, sizeof (llc_oui)))
221                 skb->protocol = htons(ETH_P_IP);
222         else {
223                 skb->protocol = ((u16 *) skb->data)[3];
224                 skb_pull(skb, RFC1483LLC_LEN);
225                 if (skb->protocol == htons(ETH_P_ARP)) {
226                         PRIV(skb->dev)->stats.rx_packets++;
227                         PRIV(skb->dev)->stats.rx_bytes += skb->len;
228                         clip_arp_rcv(skb);
229                         return;
230                 }
231         }
232         clip_vcc->last_use = jiffies;
233         PRIV(skb->dev)->stats.rx_packets++;
234         PRIV(skb->dev)->stats.rx_bytes += skb->len;
235         memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
236         netif_rx(skb);
237 }
238
239 /*
240  * Note: these spinlocks _must_not_ block on non-SMP. The only goal is that
241  * clip_pop is atomic with respect to the critical section in clip_start_xmit.
242  */
243
244 static void clip_pop(struct atm_vcc *vcc, struct sk_buff *skb)
245 {
246         struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
247         struct net_device *dev = skb->dev;
248         int old;
249         unsigned long flags;
250
251         DPRINTK("clip_pop(vcc %p)\n", vcc);
252         clip_vcc->old_pop(vcc, skb);
253         /* skb->dev == NULL in outbound ARP packets */
254         if (!dev)
255                 return;
256         spin_lock_irqsave(&PRIV(dev)->xoff_lock, flags);
257         if (atm_may_send(vcc, 0)) {
258                 old = xchg(&clip_vcc->xoff, 0);
259                 if (old)
260                         netif_wake_queue(dev);
261         }
262         spin_unlock_irqrestore(&PRIV(dev)->xoff_lock, flags);
263 }
264
265 static void clip_neigh_destroy(struct neighbour *neigh)
266 {
267         DPRINTK("clip_neigh_destroy (neigh %p)\n", neigh);
268         if (NEIGH2ENTRY(neigh)->vccs)
269                 printk(KERN_CRIT "clip_neigh_destroy: vccs != NULL !!!\n");
270         NEIGH2ENTRY(neigh)->vccs = (void *) 0xdeadbeef;
271 }
272
273 static void clip_neigh_solicit(struct neighbour *neigh, struct sk_buff *skb)
274 {
275         DPRINTK("clip_neigh_solicit (neigh %p, skb %p)\n", neigh, skb);
276         to_atmarpd(act_need, PRIV(neigh->dev)->number, NEIGH2ENTRY(neigh)->ip);
277 }
278
279 static void clip_neigh_error(struct neighbour *neigh, struct sk_buff *skb)
280 {
281 #ifndef CONFIG_ATM_CLIP_NO_ICMP
282         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
283 #endif
284         kfree_skb(skb);
285 }
286
287 static struct neigh_ops clip_neigh_ops = {
288         .family =               AF_INET,
289         .solicit =              clip_neigh_solicit,
290         .error_report =         clip_neigh_error,
291         .output =               dev_queue_xmit,
292         .connected_output =     dev_queue_xmit,
293         .hh_output =            dev_queue_xmit,
294         .queue_xmit =           dev_queue_xmit,
295 };
296
297 static int clip_constructor(struct neighbour *neigh)
298 {
299         struct atmarp_entry *entry = NEIGH2ENTRY(neigh);
300         struct net_device *dev = neigh->dev;
301         struct in_device *in_dev;
302         struct neigh_parms *parms;
303
304         DPRINTK("clip_constructor (neigh %p, entry %p)\n", neigh, entry);
305         neigh->type = inet_addr_type(entry->ip);
306         if (neigh->type != RTN_UNICAST)
307                 return -EINVAL;
308
309         rcu_read_lock();
310         in_dev = __in_dev_get_rcu(dev);
311         if (!in_dev) {
312                 rcu_read_unlock();
313                 return -EINVAL;
314         }
315
316         parms = in_dev->arp_parms;
317         __neigh_parms_put(neigh->parms);
318         neigh->parms = neigh_parms_clone(parms);
319         rcu_read_unlock();
320
321         neigh->ops = &clip_neigh_ops;
322         neigh->output = neigh->nud_state & NUD_VALID ?
323             neigh->ops->connected_output : neigh->ops->output;
324         entry->neigh = neigh;
325         entry->vccs = NULL;
326         entry->expires = jiffies - 1;
327         return 0;
328 }
329
330 static u32 clip_hash(const void *pkey, const struct net_device *dev)
331 {
332         return jhash_2words(*(u32 *) pkey, dev->ifindex, clip_tbl.hash_rnd);
333 }
334
335 static struct neigh_table clip_tbl = {
336         .family         = AF_INET,
337         .entry_size     = sizeof(struct neighbour)+sizeof(struct atmarp_entry),
338         .key_len        = 4,
339         .hash           = clip_hash,
340         .constructor    = clip_constructor,
341         .id             = "clip_arp_cache",
342
343         /* parameters are copied from ARP ... */
344         .parms = {
345                 .tbl                    = &clip_tbl,
346                 .neigh_destructor       = clip_neigh_destroy,
347                 .base_reachable_time    = 30 * HZ,
348                 .retrans_time           = 1 * HZ,
349                 .gc_staletime           = 60 * HZ,
350                 .reachable_time         = 30 * HZ,
351                 .delay_probe_time       = 5 * HZ,
352                 .queue_len              = 3,
353                 .ucast_probes           = 3,
354                 .mcast_probes           = 3,
355                 .anycast_delay          = 1 * HZ,
356                 .proxy_delay            = (8 * HZ) / 10,
357                 .proxy_qlen             = 64,
358                 .locktime               = 1 * HZ,
359         },
360         .gc_interval    = 30 * HZ,
361         .gc_thresh1     = 128,
362         .gc_thresh2     = 512,
363         .gc_thresh3     = 1024,
364 };
365
366 /* @@@ copy bh locking from arp.c -- need to bh-enable atm code before */
367
368 /*
369  * We play with the resolve flag: 0 and 1 have the usual meaning, but -1 means
370  * to allocate the neighbour entry but not to ask atmarpd for resolution. Also,
371  * don't increment the usage count. This is used to create entries in
372  * clip_setentry.
373  */
374
375 static int clip_encap(struct atm_vcc *vcc, int mode)
376 {
377         CLIP_VCC(vcc)->encap = mode;
378         return 0;
379 }
380
381 static int clip_start_xmit(struct sk_buff *skb, struct net_device *dev)
382 {
383         struct clip_priv *clip_priv = PRIV(dev);
384         struct atmarp_entry *entry;
385         struct atm_vcc *vcc;
386         int old;
387         unsigned long flags;
388
389         DPRINTK("clip_start_xmit (skb %p)\n", skb);
390         if (!skb->dst) {
391                 printk(KERN_ERR "clip_start_xmit: skb->dst == NULL\n");
392                 dev_kfree_skb(skb);
393                 clip_priv->stats.tx_dropped++;
394                 return 0;
395         }
396         if (!skb->dst->neighbour) {
397 #if 0
398                 skb->dst->neighbour = clip_find_neighbour(skb->dst, 1);
399                 if (!skb->dst->neighbour) {
400                         dev_kfree_skb(skb);     /* lost that one */
401                         clip_priv->stats.tx_dropped++;
402                         return 0;
403                 }
404 #endif
405                 printk(KERN_ERR "clip_start_xmit: NO NEIGHBOUR !\n");
406                 dev_kfree_skb(skb);
407                 clip_priv->stats.tx_dropped++;
408                 return 0;
409         }
410         entry = NEIGH2ENTRY(skb->dst->neighbour);
411         if (!entry->vccs) {
412                 if (time_after(jiffies, entry->expires)) {
413                         /* should be resolved */
414                         entry->expires = jiffies + ATMARP_RETRY_DELAY * HZ;
415                         to_atmarpd(act_need, PRIV(dev)->number, entry->ip);
416                 }
417                 if (entry->neigh->arp_queue.qlen < ATMARP_MAX_UNRES_PACKETS)
418                         skb_queue_tail(&entry->neigh->arp_queue, skb);
419                 else {
420                         dev_kfree_skb(skb);
421                         clip_priv->stats.tx_dropped++;
422                 }
423                 return 0;
424         }
425         DPRINTK("neigh %p, vccs %p\n", entry, entry->vccs);
426         ATM_SKB(skb)->vcc = vcc = entry->vccs->vcc;
427         DPRINTK("using neighbour %p, vcc %p\n", skb->dst->neighbour, vcc);
428         if (entry->vccs->encap) {
429                 void *here;
430
431                 here = skb_push(skb, RFC1483LLC_LEN);
432                 memcpy(here, llc_oui, sizeof(llc_oui));
433                 ((u16 *) here)[3] = skb->protocol;
434         }
435         atomic_add(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
436         ATM_SKB(skb)->atm_options = vcc->atm_options;
437         entry->vccs->last_use = jiffies;
438         DPRINTK("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, vcc, vcc->dev);
439         old = xchg(&entry->vccs->xoff, 1);      /* assume XOFF ... */
440         if (old) {
441                 printk(KERN_WARNING "clip_start_xmit: XOFF->XOFF transition\n");
442                 return 0;
443         }
444         clip_priv->stats.tx_packets++;
445         clip_priv->stats.tx_bytes += skb->len;
446         vcc->send(vcc, skb);
447         if (atm_may_send(vcc, 0)) {
448                 entry->vccs->xoff = 0;
449                 return 0;
450         }
451         spin_lock_irqsave(&clip_priv->xoff_lock, flags);
452         netif_stop_queue(dev);  /* XOFF -> throttle immediately */
453         barrier();
454         if (!entry->vccs->xoff)
455                 netif_start_queue(dev);
456         /* Oh, we just raced with clip_pop. netif_start_queue should be
457            good enough, because nothing should really be asleep because
458            of the brief netif_stop_queue. If this isn't true or if it
459            changes, use netif_wake_queue instead. */
460         spin_unlock_irqrestore(&clip_priv->xoff_lock, flags);
461         return 0;
462 }
463
464 static struct net_device_stats *clip_get_stats(struct net_device *dev)
465 {
466         return &PRIV(dev)->stats;
467 }
468
469 static int clip_mkip(struct atm_vcc *vcc, int timeout)
470 {
471         struct clip_vcc *clip_vcc;
472         struct sk_buff_head copy;
473         struct sk_buff *skb;
474
475         if (!vcc->push)
476                 return -EBADFD;
477         clip_vcc = kmalloc(sizeof(struct clip_vcc), GFP_KERNEL);
478         if (!clip_vcc)
479                 return -ENOMEM;
480         DPRINTK("mkip clip_vcc %p vcc %p\n", clip_vcc, vcc);
481         clip_vcc->vcc = vcc;
482         vcc->user_back = clip_vcc;
483         set_bit(ATM_VF_IS_CLIP, &vcc->flags);
484         clip_vcc->entry = NULL;
485         clip_vcc->xoff = 0;
486         clip_vcc->encap = 1;
487         clip_vcc->last_use = jiffies;
488         clip_vcc->idle_timeout = timeout * HZ;
489         clip_vcc->old_push = vcc->push;
490         clip_vcc->old_pop = vcc->pop;
491         vcc->push = clip_push;
492         vcc->pop = clip_pop;
493         skb_queue_head_init(&copy);
494         skb_migrate(&sk_atm(vcc)->sk_receive_queue, &copy);
495         /* re-process everything received between connection setup and MKIP */
496         while ((skb = skb_dequeue(&copy)) != NULL)
497                 if (!clip_devs) {
498                         atm_return(vcc, skb->truesize);
499                         kfree_skb(skb);
500                 } else {
501                         unsigned int len = skb->len;
502
503                         clip_push(vcc, skb);
504                         PRIV(skb->dev)->stats.rx_packets--;
505                         PRIV(skb->dev)->stats.rx_bytes -= len;
506                 }
507         return 0;
508 }
509
510 static int clip_setentry(struct atm_vcc *vcc, u32 ip)
511 {
512         struct neighbour *neigh;
513         struct atmarp_entry *entry;
514         int error;
515         struct clip_vcc *clip_vcc;
516         struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, .tos = 1}} };
517         struct rtable *rt;
518
519         if (vcc->push != clip_push) {
520                 printk(KERN_WARNING "clip_setentry: non-CLIP VCC\n");
521                 return -EBADF;
522         }
523         clip_vcc = CLIP_VCC(vcc);
524         if (!ip) {
525                 if (!clip_vcc->entry) {
526                         printk(KERN_ERR "hiding hidden ATMARP entry\n");
527                         return 0;
528                 }
529                 DPRINTK("setentry: remove\n");
530                 unlink_clip_vcc(clip_vcc);
531                 return 0;
532         }
533         error = ip_route_output_key(&rt, &fl);
534         if (error)
535                 return error;
536         neigh = __neigh_lookup(&clip_tbl, &ip, rt->u.dst.dev, 1);
537         ip_rt_put(rt);
538         if (!neigh)
539                 return -ENOMEM;
540         entry = NEIGH2ENTRY(neigh);
541         if (entry != clip_vcc->entry) {
542                 if (!clip_vcc->entry)
543                         DPRINTK("setentry: add\n");
544                 else {
545                         DPRINTK("setentry: update\n");
546                         unlink_clip_vcc(clip_vcc);
547                 }
548                 link_vcc(clip_vcc, entry);
549         }
550         error = neigh_update(neigh, llc_oui, NUD_PERMANENT,
551                              NEIGH_UPDATE_F_OVERRIDE | NEIGH_UPDATE_F_ADMIN);
552         neigh_release(neigh);
553         return error;
554 }
555
556 static void clip_setup(struct net_device *dev)
557 {
558         dev->hard_start_xmit = clip_start_xmit;
559         /* sg_xmit ... */
560         dev->get_stats = clip_get_stats;
561         dev->type = ARPHRD_ATM;
562         dev->hard_header_len = RFC1483LLC_LEN;
563         dev->mtu = RFC1626_MTU;
564         dev->tx_queue_len = 100;        /* "normal" queue (packets) */
565         /* When using a "real" qdisc, the qdisc determines the queue */
566         /* length. tx_queue_len is only used for the default case, */
567         /* without any more elaborate queuing. 100 is a reasonable */
568         /* compromise between decent burst-tolerance and protection */
569         /* against memory hogs. */
570 }
571
572 static int clip_create(int number)
573 {
574         struct net_device *dev;
575         struct clip_priv *clip_priv;
576         int error;
577
578         if (number != -1) {
579                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
580                         if (PRIV(dev)->number == number)
581                                 return -EEXIST;
582         } else {
583                 number = 0;
584                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
585                         if (PRIV(dev)->number >= number)
586                                 number = PRIV(dev)->number + 1;
587         }
588         dev = alloc_netdev(sizeof(struct clip_priv), "", clip_setup);
589         if (!dev)
590                 return -ENOMEM;
591         clip_priv = PRIV(dev);
592         sprintf(dev->name, "atm%d", number);
593         spin_lock_init(&clip_priv->xoff_lock);
594         clip_priv->number = number;
595         error = register_netdev(dev);
596         if (error) {
597                 free_netdev(dev);
598                 return error;
599         }
600         clip_priv->next = clip_devs;
601         clip_devs = dev;
602         DPRINTK("registered (net:%s)\n", dev->name);
603         return number;
604 }
605
606 static int clip_device_event(struct notifier_block *this, unsigned long event,
607                              void *arg)
608 {
609         struct net_device *dev = arg;
610
611         if (event == NETDEV_UNREGISTER) {
612                 neigh_ifdown(&clip_tbl, dev);
613                 return NOTIFY_DONE;
614         }
615
616         /* ignore non-CLIP devices */
617         if (dev->type != ARPHRD_ATM || dev->hard_start_xmit != clip_start_xmit)
618                 return NOTIFY_DONE;
619
620         switch (event) {
621         case NETDEV_UP:
622                 DPRINTK("clip_device_event NETDEV_UP\n");
623                 to_atmarpd(act_up, PRIV(dev)->number, 0);
624                 break;
625         case NETDEV_GOING_DOWN:
626                 DPRINTK("clip_device_event NETDEV_DOWN\n");
627                 to_atmarpd(act_down, PRIV(dev)->number, 0);
628                 break;
629         case NETDEV_CHANGE:
630         case NETDEV_CHANGEMTU:
631                 DPRINTK("clip_device_event NETDEV_CHANGE*\n");
632                 to_atmarpd(act_change, PRIV(dev)->number, 0);
633                 break;
634         }
635         return NOTIFY_DONE;
636 }
637
638 static int clip_inet_event(struct notifier_block *this, unsigned long event,
639                            void *ifa)
640 {
641         struct in_device *in_dev;
642
643         in_dev = ((struct in_ifaddr *)ifa)->ifa_dev;
644         if (!in_dev || !in_dev->dev) {
645                 printk(KERN_WARNING "clip_inet_event: no device\n");
646                 return NOTIFY_DONE;
647         }
648         /*
649          * Transitions are of the down-change-up type, so it's sufficient to
650          * handle the change on up.
651          */
652         if (event != NETDEV_UP)
653                 return NOTIFY_DONE;
654         return clip_device_event(this, NETDEV_CHANGE, in_dev->dev);
655 }
656
657
658 static struct notifier_block clip_dev_notifier = {
659         .notifier_call = clip_device_event,
660 };
661
662
663
664 static struct notifier_block clip_inet_notifier = {
665         .notifier_call = clip_inet_event,
666 };
667
668
669
670 static void atmarpd_close(struct atm_vcc *vcc)
671 {
672         DPRINTK("atmarpd_close\n");
673
674         rtnl_lock();
675         atmarpd = NULL;
676         skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
677         rtnl_unlock();
678
679         DPRINTK("(done)\n");
680         module_put(THIS_MODULE);
681 }
682
683
684 static struct atmdev_ops atmarpd_dev_ops = {
685         .close = atmarpd_close
686 };
687
688
689 static struct atm_dev atmarpd_dev = {
690         .ops =                  &atmarpd_dev_ops,
691         .type =                 "arpd",
692         .number =               999,
693         .lock =                 SPIN_LOCK_UNLOCKED
694 };
695
696
697 static int atm_init_atmarp(struct atm_vcc *vcc)
698 {
699         rtnl_lock();
700         if (atmarpd) {
701                 rtnl_unlock();
702                 return -EADDRINUSE;
703         }
704
705         mod_timer(&idle_timer, jiffies+CLIP_CHECK_INTERVAL*HZ);
706
707         atmarpd = vcc;
708         set_bit(ATM_VF_META,&vcc->flags);
709         set_bit(ATM_VF_READY,&vcc->flags);
710             /* allow replies and avoid getting closed if signaling dies */
711         vcc->dev = &atmarpd_dev;
712         vcc_insert_socket(sk_atm(vcc));
713         vcc->push = NULL;
714         vcc->pop = NULL; /* crash */
715         vcc->push_oam = NULL; /* crash */
716         rtnl_unlock();
717         return 0;
718 }
719
720 static int clip_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
721 {
722         struct atm_vcc *vcc = ATM_SD(sock);
723         int err = 0;
724
725         switch (cmd) {
726         case SIOCMKCLIP:
727         case ATMARPD_CTRL:
728         case ATMARP_MKIP:
729         case ATMARP_SETENTRY:
730         case ATMARP_ENCAP:
731                 if (!capable(CAP_NET_ADMIN))
732                         return -EPERM;
733                 break;
734         default:
735                 return -ENOIOCTLCMD;
736         }
737
738         switch (cmd) {
739         case SIOCMKCLIP:
740                 err = clip_create(arg);
741                 break;
742         case ATMARPD_CTRL:
743                 err = atm_init_atmarp(vcc);
744                 if (!err) {
745                         sock->state = SS_CONNECTED;
746                         __module_get(THIS_MODULE);
747                 }
748                 break;
749         case ATMARP_MKIP:
750                 err = clip_mkip(vcc, arg);
751                 break;
752         case ATMARP_SETENTRY:
753                 err = clip_setentry(vcc, arg);
754                 break;
755         case ATMARP_ENCAP:
756                 err = clip_encap(vcc, arg);
757                 break;
758         }
759         return err;
760 }
761
762 static struct atm_ioctl clip_ioctl_ops = {
763         .owner = THIS_MODULE,
764         .ioctl = clip_ioctl,
765 };
766
767 #ifdef CONFIG_PROC_FS
768
769 static void svc_addr(struct seq_file *seq, struct sockaddr_atmsvc *addr)
770 {
771         static int code[] = { 1, 2, 10, 6, 1, 0 };
772         static int e164[] = { 1, 8, 4, 6, 1, 0 };
773
774         if (*addr->sas_addr.pub) {
775                 seq_printf(seq, "%s", addr->sas_addr.pub);
776                 if (*addr->sas_addr.prv)
777                         seq_putc(seq, '+');
778         } else if (!*addr->sas_addr.prv) {
779                 seq_printf(seq, "%s", "(none)");
780                 return;
781         }
782         if (*addr->sas_addr.prv) {
783                 unsigned char *prv = addr->sas_addr.prv;
784                 int *fields;
785                 int i, j;
786
787                 fields = *prv == ATM_AFI_E164 ? e164 : code;
788                 for (i = 0; fields[i]; i++) {
789                         for (j = fields[i]; j; j--)
790                                 seq_printf(seq, "%02X", *prv++);
791                         if (fields[i + 1])
792                                 seq_putc(seq, '.');
793                 }
794         }
795 }
796
797 /* This means the neighbour entry has no attached VCC objects. */
798 #define SEQ_NO_VCC_TOKEN        ((void *) 2)
799
800 static void atmarp_info(struct seq_file *seq, struct net_device *dev,
801                         struct atmarp_entry *entry, struct clip_vcc *clip_vcc)
802 {
803         unsigned long exp;
804         char buf[17];
805         int svc, llc, off;
806
807         svc = ((clip_vcc == SEQ_NO_VCC_TOKEN) ||
808                (sk_atm(clip_vcc->vcc)->sk_family == AF_ATMSVC));
809
810         llc = ((clip_vcc == SEQ_NO_VCC_TOKEN) || clip_vcc->encap);
811
812         if (clip_vcc == SEQ_NO_VCC_TOKEN)
813                 exp = entry->neigh->used;
814         else
815                 exp = clip_vcc->last_use;
816
817         exp = (jiffies - exp) / HZ;
818
819         seq_printf(seq, "%-6s%-4s%-4s%5ld ",
820                    dev->name, svc ? "SVC" : "PVC", llc ? "LLC" : "NULL", exp);
821
822         off = scnprintf(buf, sizeof(buf) - 1, "%d.%d.%d.%d",
823                         NIPQUAD(entry->ip));
824         while (off < 16)
825                 buf[off++] = ' ';
826         buf[off] = '\0';
827         seq_printf(seq, "%s", buf);
828
829         if (clip_vcc == SEQ_NO_VCC_TOKEN) {
830                 if (time_before(jiffies, entry->expires))
831                         seq_printf(seq, "(resolving)\n");
832                 else
833                         seq_printf(seq, "(expired, ref %d)\n",
834                                    atomic_read(&entry->neigh->refcnt));
835         } else if (!svc) {
836                 seq_printf(seq, "%d.%d.%d\n",
837                            clip_vcc->vcc->dev->number,
838                            clip_vcc->vcc->vpi, clip_vcc->vcc->vci);
839         } else {
840                 svc_addr(seq, &clip_vcc->vcc->remote);
841                 seq_putc(seq, '\n');
842         }
843 }
844
845 struct clip_seq_state {
846         /* This member must be first. */
847         struct neigh_seq_state ns;
848
849         /* Local to clip specific iteration. */
850         struct clip_vcc *vcc;
851 };
852
853 static struct clip_vcc *clip_seq_next_vcc(struct atmarp_entry *e,
854                                           struct clip_vcc *curr)
855 {
856         if (!curr) {
857                 curr = e->vccs;
858                 if (!curr)
859                         return SEQ_NO_VCC_TOKEN;
860                 return curr;
861         }
862         if (curr == SEQ_NO_VCC_TOKEN)
863                 return NULL;
864
865         curr = curr->next;
866
867         return curr;
868 }
869
870 static void *clip_seq_vcc_walk(struct clip_seq_state *state,
871                                struct atmarp_entry *e, loff_t * pos)
872 {
873         struct clip_vcc *vcc = state->vcc;
874
875         vcc = clip_seq_next_vcc(e, vcc);
876         if (vcc && pos != NULL) {
877                 while (*pos) {
878                         vcc = clip_seq_next_vcc(e, vcc);
879                         if (!vcc)
880                                 break;
881                         --(*pos);
882                 }
883         }
884         state->vcc = vcc;
885
886         return vcc;
887 }
888
889 static void *clip_seq_sub_iter(struct neigh_seq_state *_state,
890                                struct neighbour *n, loff_t * pos)
891 {
892         struct clip_seq_state *state = (struct clip_seq_state *)_state;
893
894         return clip_seq_vcc_walk(state, NEIGH2ENTRY(n), pos);
895 }
896
897 static void *clip_seq_start(struct seq_file *seq, loff_t * pos)
898 {
899         return neigh_seq_start(seq, pos, &clip_tbl, NEIGH_SEQ_NEIGH_ONLY);
900 }
901
902 static int clip_seq_show(struct seq_file *seq, void *v)
903 {
904         static char atm_arp_banner[] =
905             "IPitf TypeEncp Idle IP address      ATM address\n";
906
907         if (v == SEQ_START_TOKEN) {
908                 seq_puts(seq, atm_arp_banner);
909         } else {
910                 struct clip_seq_state *state = seq->private;
911                 struct neighbour *n = v;
912                 struct clip_vcc *vcc = state->vcc;
913
914                 atmarp_info(seq, n->dev, NEIGH2ENTRY(n), vcc);
915         }
916         return 0;
917 }
918
919 static struct seq_operations arp_seq_ops = {
920         .start  = clip_seq_start,
921         .next   = neigh_seq_next,
922         .stop   = neigh_seq_stop,
923         .show   = clip_seq_show,
924 };
925
926 static int arp_seq_open(struct inode *inode, struct file *file)
927 {
928         struct clip_seq_state *state;
929         struct seq_file *seq;
930         int rc = -EAGAIN;
931
932         state = kmalloc(sizeof(*state), GFP_KERNEL);
933         if (!state) {
934                 rc = -ENOMEM;
935                 goto out_kfree;
936         }
937         memset(state, 0, sizeof(*state));
938         state->ns.neigh_sub_iter = clip_seq_sub_iter;
939
940         rc = seq_open(file, &arp_seq_ops);
941         if (rc)
942                 goto out_kfree;
943
944         seq = file->private_data;
945         seq->private = state;
946 out:
947         return rc;
948
949 out_kfree:
950         kfree(state);
951         goto out;
952 }
953
954 static struct file_operations arp_seq_fops = {
955         .open           = arp_seq_open,
956         .read           = seq_read,
957         .llseek         = seq_lseek,
958         .release        = seq_release_private,
959         .owner          = THIS_MODULE
960 };
961 #endif
962
963 static int __init atm_clip_init(void)
964 {
965         struct proc_dir_entry *p;
966         neigh_table_init_no_netlink(&clip_tbl);
967
968         clip_tbl_hook = &clip_tbl;
969         register_atm_ioctl(&clip_ioctl_ops);
970         register_netdevice_notifier(&clip_dev_notifier);
971         register_inetaddr_notifier(&clip_inet_notifier);
972
973         setup_timer(&idle_timer, idle_timer_check, 0);
974
975         p = create_proc_entry("arp", S_IRUGO, atm_proc_root);
976         if (p)
977                 p->proc_fops = &arp_seq_fops;
978
979         return 0;
980 }
981
982 static void __exit atm_clip_exit(void)
983 {
984         struct net_device *dev, *next;
985
986         remove_proc_entry("arp", atm_proc_root);
987
988         unregister_inetaddr_notifier(&clip_inet_notifier);
989         unregister_netdevice_notifier(&clip_dev_notifier);
990
991         deregister_atm_ioctl(&clip_ioctl_ops);
992
993         /* First, stop the idle timer, so it stops banging
994          * on the table.
995          */
996         del_timer_sync(&idle_timer);
997
998         /* Next, purge the table, so that the device
999          * unregister loop below does not hang due to
1000          * device references remaining in the table.
1001          */
1002         neigh_ifdown(&clip_tbl, NULL);
1003
1004         dev = clip_devs;
1005         while (dev) {
1006                 next = PRIV(dev)->next;
1007                 unregister_netdev(dev);
1008                 free_netdev(dev);
1009                 dev = next;
1010         }
1011
1012         /* Now it is safe to fully shutdown whole table. */
1013         neigh_table_clear(&clip_tbl);
1014
1015         clip_tbl_hook = NULL;
1016 }
1017
1018 module_init(atm_clip_init);
1019 module_exit(atm_clip_exit);
1020 MODULE_AUTHOR("Werner Almesberger");
1021 MODULE_DESCRIPTION("Classical/IP over ATM interface");
1022 MODULE_LICENSE("GPL");