876b77f1474521b8e9a77a425cac5e7e53edb2cb
[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
44 #if 0
45 #define DPRINTK(format,args...) printk(format,##args)
46 #else
47 #define DPRINTK(format,args...)
48 #endif
49
50
51 static struct net_device *clip_devs;
52 static struct atm_vcc *atmarpd;
53 static struct neigh_table clip_tbl;
54 static struct timer_list idle_timer;
55
56 static int to_atmarpd(enum atmarp_ctrl_type type, int itf, __be32 ip)
57 {
58         struct sock *sk;
59         struct atmarp_ctrl *ctrl;
60         struct sk_buff *skb;
61
62         DPRINTK("to_atmarpd(%d)\n", type);
63         if (!atmarpd)
64                 return -EUNATCH;
65         skb = alloc_skb(sizeof(struct atmarp_ctrl),GFP_ATOMIC);
66         if (!skb)
67                 return -ENOMEM;
68         ctrl = (struct atmarp_ctrl *) skb_put(skb,sizeof(struct atmarp_ctrl));
69         ctrl->type = type;
70         ctrl->itf_num = itf;
71         ctrl->ip = ip;
72         atm_force_charge(atmarpd, skb->truesize);
73
74         sk = sk_atm(atmarpd);
75         skb_queue_tail(&sk->sk_receive_queue, skb);
76         sk->sk_data_ready(sk, skb->len);
77         return 0;
78 }
79
80 static void link_vcc(struct clip_vcc *clip_vcc, struct atmarp_entry *entry)
81 {
82         DPRINTK("link_vcc %p to entry %p (neigh %p)\n", clip_vcc, entry,
83                 entry->neigh);
84         clip_vcc->entry = entry;
85         clip_vcc->xoff = 0;     /* @@@ may overrun buffer by one packet */
86         clip_vcc->next = entry->vccs;
87         entry->vccs = clip_vcc;
88         entry->neigh->used = jiffies;
89 }
90
91 static void unlink_clip_vcc(struct clip_vcc *clip_vcc)
92 {
93         struct atmarp_entry *entry = clip_vcc->entry;
94         struct clip_vcc **walk;
95
96         if (!entry) {
97                 printk(KERN_CRIT "!clip_vcc->entry (clip_vcc %p)\n", clip_vcc);
98                 return;
99         }
100         netif_tx_lock_bh(entry->neigh->dev);    /* block clip_start_xmit() */
101         entry->neigh->used = jiffies;
102         for (walk = &entry->vccs; *walk; walk = &(*walk)->next)
103                 if (*walk == clip_vcc) {
104                         int error;
105
106                         *walk = clip_vcc->next; /* atomic */
107                         clip_vcc->entry = NULL;
108                         if (clip_vcc->xoff)
109                                 netif_wake_queue(entry->neigh->dev);
110                         if (entry->vccs)
111                                 goto out;
112                         entry->expires = jiffies - 1;
113                         /* force resolution or expiration */
114                         error = neigh_update(entry->neigh, NULL, NUD_NONE,
115                                              NEIGH_UPDATE_F_ADMIN);
116                         if (error)
117                                 printk(KERN_CRIT "unlink_clip_vcc: "
118                                        "neigh_update failed with %d\n", error);
119                         goto out;
120                 }
121         printk(KERN_CRIT "ATMARP: unlink_clip_vcc failed (entry %p, vcc "
122                "0x%p)\n", entry, clip_vcc);
123       out:
124         netif_tx_unlock_bh(entry->neigh->dev);
125 }
126
127 /* The neighbour entry n->lock is held. */
128 static int neigh_check_cb(struct neighbour *n)
129 {
130         struct atmarp_entry *entry = NEIGH2ENTRY(n);
131         struct clip_vcc *cv;
132
133         for (cv = entry->vccs; cv; cv = cv->next) {
134                 unsigned long exp = cv->last_use + cv->idle_timeout;
135
136                 if (cv->idle_timeout && time_after(jiffies, exp)) {
137                         DPRINTK("releasing vcc %p->%p of entry %p\n",
138                                 cv, cv->vcc, entry);
139                         vcc_release_async(cv->vcc, -ETIMEDOUT);
140                 }
141         }
142
143         if (entry->vccs || time_before(jiffies, entry->expires))
144                 return 0;
145
146         if (atomic_read(&n->refcnt) > 1) {
147                 struct sk_buff *skb;
148
149                 DPRINTK("destruction postponed with ref %d\n",
150                         atomic_read(&n->refcnt));
151
152                 while ((skb = skb_dequeue(&n->arp_queue)) != NULL)
153                         dev_kfree_skb(skb);
154
155                 return 0;
156         }
157
158         DPRINTK("expired neigh %p\n", n);
159         return 1;
160 }
161
162 static void idle_timer_check(unsigned long dummy)
163 {
164         write_lock(&clip_tbl.lock);
165         __neigh_for_each_release(&clip_tbl, neigh_check_cb);
166         mod_timer(&idle_timer, jiffies + CLIP_CHECK_INTERVAL * HZ);
167         write_unlock(&clip_tbl.lock);
168 }
169
170 static int clip_arp_rcv(struct sk_buff *skb)
171 {
172         struct atm_vcc *vcc;
173
174         DPRINTK("clip_arp_rcv\n");
175         vcc = ATM_SKB(skb)->vcc;
176         if (!vcc || !atm_charge(vcc, skb->truesize)) {
177                 dev_kfree_skb_any(skb);
178                 return 0;
179         }
180         DPRINTK("pushing to %p\n", vcc);
181         DPRINTK("using %p\n", CLIP_VCC(vcc)->old_push);
182         CLIP_VCC(vcc)->old_push(vcc, skb);
183         return 0;
184 }
185
186 static const unsigned char llc_oui[] = {
187         0xaa,   /* DSAP: non-ISO */
188         0xaa,   /* SSAP: non-ISO */
189         0x03,   /* Ctrl: Unnumbered Information Command PDU */
190         0x00,   /* OUI: EtherType */
191         0x00,
192         0x00
193 };
194
195 static void clip_push(struct atm_vcc *vcc, struct sk_buff *skb)
196 {
197         struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
198
199         DPRINTK("clip push\n");
200         if (!skb) {
201                 DPRINTK("removing VCC %p\n", clip_vcc);
202                 if (clip_vcc->entry)
203                         unlink_clip_vcc(clip_vcc);
204                 clip_vcc->old_push(vcc, NULL);  /* pass on the bad news */
205                 kfree(clip_vcc);
206                 return;
207         }
208         atm_return(vcc, skb->truesize);
209         skb->dev = clip_vcc->entry ? clip_vcc->entry->neigh->dev : clip_devs;
210         /* clip_vcc->entry == NULL if we don't have an IP address yet */
211         if (!skb->dev) {
212                 dev_kfree_skb_any(skb);
213                 return;
214         }
215         ATM_SKB(skb)->vcc = vcc;
216         skb_reset_mac_header(skb);
217         if (!clip_vcc->encap
218             || skb->len < RFC1483LLC_LEN
219             || memcmp(skb->data, llc_oui, sizeof (llc_oui)))
220                 skb->protocol = htons(ETH_P_IP);
221         else {
222                 skb->protocol = ((__be16 *) skb->data)[3];
223                 skb_pull(skb, RFC1483LLC_LEN);
224                 if (skb->protocol == htons(ETH_P_ARP)) {
225                         PRIV(skb->dev)->stats.rx_packets++;
226                         PRIV(skb->dev)->stats.rx_bytes += skb->len;
227                         clip_arp_rcv(skb);
228                         return;
229                 }
230         }
231         clip_vcc->last_use = jiffies;
232         PRIV(skb->dev)->stats.rx_packets++;
233         PRIV(skb->dev)->stats.rx_bytes += skb->len;
234         memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
235         netif_rx(skb);
236 }
237
238 /*
239  * Note: these spinlocks _must_not_ block on non-SMP. The only goal is that
240  * clip_pop is atomic with respect to the critical section in clip_start_xmit.
241  */
242
243 static void clip_pop(struct atm_vcc *vcc, struct sk_buff *skb)
244 {
245         struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
246         struct net_device *dev = skb->dev;
247         int old;
248         unsigned long flags;
249
250         DPRINTK("clip_pop(vcc %p)\n", vcc);
251         clip_vcc->old_pop(vcc, skb);
252         /* skb->dev == NULL in outbound ARP packets */
253         if (!dev)
254                 return;
255         spin_lock_irqsave(&PRIV(dev)->xoff_lock, flags);
256         if (atm_may_send(vcc, 0)) {
257                 old = xchg(&clip_vcc->xoff, 0);
258                 if (old)
259                         netif_wake_queue(dev);
260         }
261         spin_unlock_irqrestore(&PRIV(dev)->xoff_lock, flags);
262 }
263
264 static void clip_neigh_solicit(struct neighbour *neigh, struct sk_buff *skb)
265 {
266         DPRINTK("clip_neigh_solicit (neigh %p, skb %p)\n", neigh, skb);
267         to_atmarpd(act_need, PRIV(neigh->dev)->number, NEIGH2ENTRY(neigh)->ip);
268 }
269
270 static void clip_neigh_error(struct neighbour *neigh, struct sk_buff *skb)
271 {
272 #ifndef CONFIG_ATM_CLIP_NO_ICMP
273         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
274 #endif
275         kfree_skb(skb);
276 }
277
278 static struct neigh_ops clip_neigh_ops = {
279         .family =               AF_INET,
280         .solicit =              clip_neigh_solicit,
281         .error_report =         clip_neigh_error,
282         .output =               dev_queue_xmit,
283         .connected_output =     dev_queue_xmit,
284         .hh_output =            dev_queue_xmit,
285         .queue_xmit =           dev_queue_xmit,
286 };
287
288 static int clip_constructor(struct neighbour *neigh)
289 {
290         struct atmarp_entry *entry = NEIGH2ENTRY(neigh);
291         struct net_device *dev = neigh->dev;
292         struct in_device *in_dev;
293         struct neigh_parms *parms;
294
295         DPRINTK("clip_constructor (neigh %p, entry %p)\n", neigh, entry);
296         neigh->type = inet_addr_type(entry->ip);
297         if (neigh->type != RTN_UNICAST)
298                 return -EINVAL;
299
300         rcu_read_lock();
301         in_dev = __in_dev_get_rcu(dev);
302         if (!in_dev) {
303                 rcu_read_unlock();
304                 return -EINVAL;
305         }
306
307         parms = in_dev->arp_parms;
308         __neigh_parms_put(neigh->parms);
309         neigh->parms = neigh_parms_clone(parms);
310         rcu_read_unlock();
311
312         neigh->ops = &clip_neigh_ops;
313         neigh->output = neigh->nud_state & NUD_VALID ?
314             neigh->ops->connected_output : neigh->ops->output;
315         entry->neigh = neigh;
316         entry->vccs = NULL;
317         entry->expires = jiffies - 1;
318         return 0;
319 }
320
321 static u32 clip_hash(const void *pkey, const struct net_device *dev)
322 {
323         return jhash_2words(*(u32 *) pkey, dev->ifindex, clip_tbl.hash_rnd);
324 }
325
326 static struct neigh_table clip_tbl = {
327         .family         = AF_INET,
328         .entry_size     = sizeof(struct neighbour)+sizeof(struct atmarp_entry),
329         .key_len        = 4,
330         .hash           = clip_hash,
331         .constructor    = clip_constructor,
332         .id             = "clip_arp_cache",
333
334         /* parameters are copied from ARP ... */
335         .parms = {
336                 .tbl                    = &clip_tbl,
337                 .base_reachable_time    = 30 * HZ,
338                 .retrans_time           = 1 * HZ,
339                 .gc_staletime           = 60 * HZ,
340                 .reachable_time         = 30 * HZ,
341                 .delay_probe_time       = 5 * HZ,
342                 .queue_len              = 3,
343                 .ucast_probes           = 3,
344                 .mcast_probes           = 3,
345                 .anycast_delay          = 1 * HZ,
346                 .proxy_delay            = (8 * HZ) / 10,
347                 .proxy_qlen             = 64,
348                 .locktime               = 1 * HZ,
349         },
350         .gc_interval    = 30 * HZ,
351         .gc_thresh1     = 128,
352         .gc_thresh2     = 512,
353         .gc_thresh3     = 1024,
354 };
355
356 /* @@@ copy bh locking from arp.c -- need to bh-enable atm code before */
357
358 /*
359  * We play with the resolve flag: 0 and 1 have the usual meaning, but -1 means
360  * to allocate the neighbour entry but not to ask atmarpd for resolution. Also,
361  * don't increment the usage count. This is used to create entries in
362  * clip_setentry.
363  */
364
365 static int clip_encap(struct atm_vcc *vcc, int mode)
366 {
367         CLIP_VCC(vcc)->encap = mode;
368         return 0;
369 }
370
371 static int clip_start_xmit(struct sk_buff *skb, struct net_device *dev)
372 {
373         struct clip_priv *clip_priv = PRIV(dev);
374         struct atmarp_entry *entry;
375         struct atm_vcc *vcc;
376         int old;
377         unsigned long flags;
378
379         DPRINTK("clip_start_xmit (skb %p)\n", skb);
380         if (!skb->dst) {
381                 printk(KERN_ERR "clip_start_xmit: skb->dst == NULL\n");
382                 dev_kfree_skb(skb);
383                 clip_priv->stats.tx_dropped++;
384                 return 0;
385         }
386         if (!skb->dst->neighbour) {
387 #if 0
388                 skb->dst->neighbour = clip_find_neighbour(skb->dst, 1);
389                 if (!skb->dst->neighbour) {
390                         dev_kfree_skb(skb);     /* lost that one */
391                         clip_priv->stats.tx_dropped++;
392                         return 0;
393                 }
394 #endif
395                 printk(KERN_ERR "clip_start_xmit: NO NEIGHBOUR !\n");
396                 dev_kfree_skb(skb);
397                 clip_priv->stats.tx_dropped++;
398                 return 0;
399         }
400         entry = NEIGH2ENTRY(skb->dst->neighbour);
401         if (!entry->vccs) {
402                 if (time_after(jiffies, entry->expires)) {
403                         /* should be resolved */
404                         entry->expires = jiffies + ATMARP_RETRY_DELAY * HZ;
405                         to_atmarpd(act_need, PRIV(dev)->number, entry->ip);
406                 }
407                 if (entry->neigh->arp_queue.qlen < ATMARP_MAX_UNRES_PACKETS)
408                         skb_queue_tail(&entry->neigh->arp_queue, skb);
409                 else {
410                         dev_kfree_skb(skb);
411                         clip_priv->stats.tx_dropped++;
412                 }
413                 return 0;
414         }
415         DPRINTK("neigh %p, vccs %p\n", entry, entry->vccs);
416         ATM_SKB(skb)->vcc = vcc = entry->vccs->vcc;
417         DPRINTK("using neighbour %p, vcc %p\n", skb->dst->neighbour, vcc);
418         if (entry->vccs->encap) {
419                 void *here;
420
421                 here = skb_push(skb, RFC1483LLC_LEN);
422                 memcpy(here, llc_oui, sizeof(llc_oui));
423                 ((__be16 *) here)[3] = skb->protocol;
424         }
425         atomic_add(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
426         ATM_SKB(skb)->atm_options = vcc->atm_options;
427         entry->vccs->last_use = jiffies;
428         DPRINTK("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, vcc, vcc->dev);
429         old = xchg(&entry->vccs->xoff, 1);      /* assume XOFF ... */
430         if (old) {
431                 printk(KERN_WARNING "clip_start_xmit: XOFF->XOFF transition\n");
432                 return 0;
433         }
434         clip_priv->stats.tx_packets++;
435         clip_priv->stats.tx_bytes += skb->len;
436         vcc->send(vcc, skb);
437         if (atm_may_send(vcc, 0)) {
438                 entry->vccs->xoff = 0;
439                 return 0;
440         }
441         spin_lock_irqsave(&clip_priv->xoff_lock, flags);
442         netif_stop_queue(dev);  /* XOFF -> throttle immediately */
443         barrier();
444         if (!entry->vccs->xoff)
445                 netif_start_queue(dev);
446         /* Oh, we just raced with clip_pop. netif_start_queue should be
447            good enough, because nothing should really be asleep because
448            of the brief netif_stop_queue. If this isn't true or if it
449            changes, use netif_wake_queue instead. */
450         spin_unlock_irqrestore(&clip_priv->xoff_lock, flags);
451         return 0;
452 }
453
454 static struct net_device_stats *clip_get_stats(struct net_device *dev)
455 {
456         return &PRIV(dev)->stats;
457 }
458
459 static int clip_mkip(struct atm_vcc *vcc, int timeout)
460 {
461         struct clip_vcc *clip_vcc;
462         struct sk_buff *skb;
463         struct sk_buff_head *rq;
464         unsigned long flags;
465
466         if (!vcc->push)
467                 return -EBADFD;
468         clip_vcc = kmalloc(sizeof(struct clip_vcc), GFP_KERNEL);
469         if (!clip_vcc)
470                 return -ENOMEM;
471         DPRINTK("mkip clip_vcc %p vcc %p\n", clip_vcc, vcc);
472         clip_vcc->vcc = vcc;
473         vcc->user_back = clip_vcc;
474         set_bit(ATM_VF_IS_CLIP, &vcc->flags);
475         clip_vcc->entry = NULL;
476         clip_vcc->xoff = 0;
477         clip_vcc->encap = 1;
478         clip_vcc->last_use = jiffies;
479         clip_vcc->idle_timeout = timeout * HZ;
480         clip_vcc->old_push = vcc->push;
481         clip_vcc->old_pop = vcc->pop;
482         vcc->push = clip_push;
483         vcc->pop = clip_pop;
484
485         rq = &sk_atm(vcc)->sk_receive_queue;
486
487         spin_lock_irqsave(&rq->lock, flags);
488         if (skb_queue_empty(rq)) {
489                 skb = NULL;
490         } else {
491                 /* NULL terminate the list.  */
492                 rq->prev->next = NULL;
493                 skb = rq->next;
494         }
495         rq->prev = rq->next = (struct sk_buff *)rq;
496         rq->qlen = 0;
497         spin_unlock_irqrestore(&rq->lock, flags);
498
499         /* re-process everything received between connection setup and MKIP */
500         while (skb) {
501                 struct sk_buff *next = skb->next;
502
503                 skb->next = skb->prev = NULL;
504                 if (!clip_devs) {
505                         atm_return(vcc, skb->truesize);
506                         kfree_skb(skb);
507                 } else {
508                         unsigned int len = skb->len;
509
510                         skb_get(skb);
511                         clip_push(vcc, skb);
512                         PRIV(skb->dev)->stats.rx_packets--;
513                         PRIV(skb->dev)->stats.rx_bytes -= len;
514                         kfree_skb(skb);
515                 }
516
517                 skb = next;
518         }
519         return 0;
520 }
521
522 static int clip_setentry(struct atm_vcc *vcc, __be32 ip)
523 {
524         struct neighbour *neigh;
525         struct atmarp_entry *entry;
526         int error;
527         struct clip_vcc *clip_vcc;
528         struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, .tos = 1}} };
529         struct rtable *rt;
530
531         if (vcc->push != clip_push) {
532                 printk(KERN_WARNING "clip_setentry: non-CLIP VCC\n");
533                 return -EBADF;
534         }
535         clip_vcc = CLIP_VCC(vcc);
536         if (!ip) {
537                 if (!clip_vcc->entry) {
538                         printk(KERN_ERR "hiding hidden ATMARP entry\n");
539                         return 0;
540                 }
541                 DPRINTK("setentry: remove\n");
542                 unlink_clip_vcc(clip_vcc);
543                 return 0;
544         }
545         error = ip_route_output_key(&rt, &fl);
546         if (error)
547                 return error;
548         neigh = __neigh_lookup(&clip_tbl, &ip, rt->u.dst.dev, 1);
549         ip_rt_put(rt);
550         if (!neigh)
551                 return -ENOMEM;
552         entry = NEIGH2ENTRY(neigh);
553         if (entry != clip_vcc->entry) {
554                 if (!clip_vcc->entry)
555                         DPRINTK("setentry: add\n");
556                 else {
557                         DPRINTK("setentry: update\n");
558                         unlink_clip_vcc(clip_vcc);
559                 }
560                 link_vcc(clip_vcc, entry);
561         }
562         error = neigh_update(neigh, llc_oui, NUD_PERMANENT,
563                              NEIGH_UPDATE_F_OVERRIDE | NEIGH_UPDATE_F_ADMIN);
564         neigh_release(neigh);
565         return error;
566 }
567
568 static void clip_setup(struct net_device *dev)
569 {
570         dev->hard_start_xmit = clip_start_xmit;
571         /* sg_xmit ... */
572         dev->get_stats = clip_get_stats;
573         dev->type = ARPHRD_ATM;
574         dev->hard_header_len = RFC1483LLC_LEN;
575         dev->mtu = RFC1626_MTU;
576         dev->tx_queue_len = 100;        /* "normal" queue (packets) */
577         /* When using a "real" qdisc, the qdisc determines the queue */
578         /* length. tx_queue_len is only used for the default case, */
579         /* without any more elaborate queuing. 100 is a reasonable */
580         /* compromise between decent burst-tolerance and protection */
581         /* against memory hogs. */
582 }
583
584 static int clip_create(int number)
585 {
586         struct net_device *dev;
587         struct clip_priv *clip_priv;
588         int error;
589
590         if (number != -1) {
591                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
592                         if (PRIV(dev)->number == number)
593                                 return -EEXIST;
594         } else {
595                 number = 0;
596                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
597                         if (PRIV(dev)->number >= number)
598                                 number = PRIV(dev)->number + 1;
599         }
600         dev = alloc_netdev(sizeof(struct clip_priv), "", clip_setup);
601         if (!dev)
602                 return -ENOMEM;
603         clip_priv = PRIV(dev);
604         sprintf(dev->name, "atm%d", number);
605         spin_lock_init(&clip_priv->xoff_lock);
606         clip_priv->number = number;
607         error = register_netdev(dev);
608         if (error) {
609                 free_netdev(dev);
610                 return error;
611         }
612         clip_priv->next = clip_devs;
613         clip_devs = dev;
614         DPRINTK("registered (net:%s)\n", dev->name);
615         return number;
616 }
617
618 static int clip_device_event(struct notifier_block *this, unsigned long event,
619                              void *arg)
620 {
621         struct net_device *dev = arg;
622
623         if (event == NETDEV_UNREGISTER) {
624                 neigh_ifdown(&clip_tbl, dev);
625                 return NOTIFY_DONE;
626         }
627
628         /* ignore non-CLIP devices */
629         if (dev->type != ARPHRD_ATM || dev->hard_start_xmit != clip_start_xmit)
630                 return NOTIFY_DONE;
631
632         switch (event) {
633         case NETDEV_UP:
634                 DPRINTK("clip_device_event NETDEV_UP\n");
635                 to_atmarpd(act_up, PRIV(dev)->number, 0);
636                 break;
637         case NETDEV_GOING_DOWN:
638                 DPRINTK("clip_device_event NETDEV_DOWN\n");
639                 to_atmarpd(act_down, PRIV(dev)->number, 0);
640                 break;
641         case NETDEV_CHANGE:
642         case NETDEV_CHANGEMTU:
643                 DPRINTK("clip_device_event NETDEV_CHANGE*\n");
644                 to_atmarpd(act_change, PRIV(dev)->number, 0);
645                 break;
646         }
647         return NOTIFY_DONE;
648 }
649
650 static int clip_inet_event(struct notifier_block *this, unsigned long event,
651                            void *ifa)
652 {
653         struct in_device *in_dev;
654
655         in_dev = ((struct in_ifaddr *)ifa)->ifa_dev;
656         if (!in_dev || !in_dev->dev) {
657                 printk(KERN_WARNING "clip_inet_event: no device\n");
658                 return NOTIFY_DONE;
659         }
660         /*
661          * Transitions are of the down-change-up type, so it's sufficient to
662          * handle the change on up.
663          */
664         if (event != NETDEV_UP)
665                 return NOTIFY_DONE;
666         return clip_device_event(this, NETDEV_CHANGE, in_dev->dev);
667 }
668
669
670 static struct notifier_block clip_dev_notifier = {
671         .notifier_call = clip_device_event,
672 };
673
674
675
676 static struct notifier_block clip_inet_notifier = {
677         .notifier_call = clip_inet_event,
678 };
679
680
681
682 static void atmarpd_close(struct atm_vcc *vcc)
683 {
684         DPRINTK("atmarpd_close\n");
685
686         rtnl_lock();
687         atmarpd = NULL;
688         skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
689         rtnl_unlock();
690
691         DPRINTK("(done)\n");
692         module_put(THIS_MODULE);
693 }
694
695
696 static struct atmdev_ops atmarpd_dev_ops = {
697         .close = atmarpd_close
698 };
699
700
701 static struct atm_dev atmarpd_dev = {
702         .ops =                  &atmarpd_dev_ops,
703         .type =                 "arpd",
704         .number =               999,
705         .lock =                 __SPIN_LOCK_UNLOCKED(atmarpd_dev.lock)
706 };
707
708
709 static int atm_init_atmarp(struct atm_vcc *vcc)
710 {
711         rtnl_lock();
712         if (atmarpd) {
713                 rtnl_unlock();
714                 return -EADDRINUSE;
715         }
716
717         mod_timer(&idle_timer, jiffies+CLIP_CHECK_INTERVAL*HZ);
718
719         atmarpd = vcc;
720         set_bit(ATM_VF_META,&vcc->flags);
721         set_bit(ATM_VF_READY,&vcc->flags);
722             /* allow replies and avoid getting closed if signaling dies */
723         vcc->dev = &atmarpd_dev;
724         vcc_insert_socket(sk_atm(vcc));
725         vcc->push = NULL;
726         vcc->pop = NULL; /* crash */
727         vcc->push_oam = NULL; /* crash */
728         rtnl_unlock();
729         return 0;
730 }
731
732 static int clip_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
733 {
734         struct atm_vcc *vcc = ATM_SD(sock);
735         int err = 0;
736
737         switch (cmd) {
738         case SIOCMKCLIP:
739         case ATMARPD_CTRL:
740         case ATMARP_MKIP:
741         case ATMARP_SETENTRY:
742         case ATMARP_ENCAP:
743                 if (!capable(CAP_NET_ADMIN))
744                         return -EPERM;
745                 break;
746         default:
747                 return -ENOIOCTLCMD;
748         }
749
750         switch (cmd) {
751         case SIOCMKCLIP:
752                 err = clip_create(arg);
753                 break;
754         case ATMARPD_CTRL:
755                 err = atm_init_atmarp(vcc);
756                 if (!err) {
757                         sock->state = SS_CONNECTED;
758                         __module_get(THIS_MODULE);
759                 }
760                 break;
761         case ATMARP_MKIP:
762                 err = clip_mkip(vcc, arg);
763                 break;
764         case ATMARP_SETENTRY:
765                 err = clip_setentry(vcc, (__force __be32)arg);
766                 break;
767         case ATMARP_ENCAP:
768                 err = clip_encap(vcc, arg);
769                 break;
770         }
771         return err;
772 }
773
774 static struct atm_ioctl clip_ioctl_ops = {
775         .owner = THIS_MODULE,
776         .ioctl = clip_ioctl,
777 };
778
779 #ifdef CONFIG_PROC_FS
780
781 static void svc_addr(struct seq_file *seq, struct sockaddr_atmsvc *addr)
782 {
783         static int code[] = { 1, 2, 10, 6, 1, 0 };
784         static int e164[] = { 1, 8, 4, 6, 1, 0 };
785
786         if (*addr->sas_addr.pub) {
787                 seq_printf(seq, "%s", addr->sas_addr.pub);
788                 if (*addr->sas_addr.prv)
789                         seq_putc(seq, '+');
790         } else if (!*addr->sas_addr.prv) {
791                 seq_printf(seq, "%s", "(none)");
792                 return;
793         }
794         if (*addr->sas_addr.prv) {
795                 unsigned char *prv = addr->sas_addr.prv;
796                 int *fields;
797                 int i, j;
798
799                 fields = *prv == ATM_AFI_E164 ? e164 : code;
800                 for (i = 0; fields[i]; i++) {
801                         for (j = fields[i]; j; j--)
802                                 seq_printf(seq, "%02X", *prv++);
803                         if (fields[i + 1])
804                                 seq_putc(seq, '.');
805                 }
806         }
807 }
808
809 /* This means the neighbour entry has no attached VCC objects. */
810 #define SEQ_NO_VCC_TOKEN        ((void *) 2)
811
812 static void atmarp_info(struct seq_file *seq, struct net_device *dev,
813                         struct atmarp_entry *entry, struct clip_vcc *clip_vcc)
814 {
815         unsigned long exp;
816         char buf[17];
817         int svc, llc, off;
818
819         svc = ((clip_vcc == SEQ_NO_VCC_TOKEN) ||
820                (sk_atm(clip_vcc->vcc)->sk_family == AF_ATMSVC));
821
822         llc = ((clip_vcc == SEQ_NO_VCC_TOKEN) || clip_vcc->encap);
823
824         if (clip_vcc == SEQ_NO_VCC_TOKEN)
825                 exp = entry->neigh->used;
826         else
827                 exp = clip_vcc->last_use;
828
829         exp = (jiffies - exp) / HZ;
830
831         seq_printf(seq, "%-6s%-4s%-4s%5ld ",
832                    dev->name, svc ? "SVC" : "PVC", llc ? "LLC" : "NULL", exp);
833
834         off = scnprintf(buf, sizeof(buf) - 1, "%d.%d.%d.%d",
835                         NIPQUAD(entry->ip));
836         while (off < 16)
837                 buf[off++] = ' ';
838         buf[off] = '\0';
839         seq_printf(seq, "%s", buf);
840
841         if (clip_vcc == SEQ_NO_VCC_TOKEN) {
842                 if (time_before(jiffies, entry->expires))
843                         seq_printf(seq, "(resolving)\n");
844                 else
845                         seq_printf(seq, "(expired, ref %d)\n",
846                                    atomic_read(&entry->neigh->refcnt));
847         } else if (!svc) {
848                 seq_printf(seq, "%d.%d.%d\n",
849                            clip_vcc->vcc->dev->number,
850                            clip_vcc->vcc->vpi, clip_vcc->vcc->vci);
851         } else {
852                 svc_addr(seq, &clip_vcc->vcc->remote);
853                 seq_putc(seq, '\n');
854         }
855 }
856
857 struct clip_seq_state {
858         /* This member must be first. */
859         struct neigh_seq_state ns;
860
861         /* Local to clip specific iteration. */
862         struct clip_vcc *vcc;
863 };
864
865 static struct clip_vcc *clip_seq_next_vcc(struct atmarp_entry *e,
866                                           struct clip_vcc *curr)
867 {
868         if (!curr) {
869                 curr = e->vccs;
870                 if (!curr)
871                         return SEQ_NO_VCC_TOKEN;
872                 return curr;
873         }
874         if (curr == SEQ_NO_VCC_TOKEN)
875                 return NULL;
876
877         curr = curr->next;
878
879         return curr;
880 }
881
882 static void *clip_seq_vcc_walk(struct clip_seq_state *state,
883                                struct atmarp_entry *e, loff_t * pos)
884 {
885         struct clip_vcc *vcc = state->vcc;
886
887         vcc = clip_seq_next_vcc(e, vcc);
888         if (vcc && pos != NULL) {
889                 while (*pos) {
890                         vcc = clip_seq_next_vcc(e, vcc);
891                         if (!vcc)
892                                 break;
893                         --(*pos);
894                 }
895         }
896         state->vcc = vcc;
897
898         return vcc;
899 }
900
901 static void *clip_seq_sub_iter(struct neigh_seq_state *_state,
902                                struct neighbour *n, loff_t * pos)
903 {
904         struct clip_seq_state *state = (struct clip_seq_state *)_state;
905
906         return clip_seq_vcc_walk(state, NEIGH2ENTRY(n), pos);
907 }
908
909 static void *clip_seq_start(struct seq_file *seq, loff_t * pos)
910 {
911         return neigh_seq_start(seq, pos, &clip_tbl, NEIGH_SEQ_NEIGH_ONLY);
912 }
913
914 static int clip_seq_show(struct seq_file *seq, void *v)
915 {
916         static char atm_arp_banner[] =
917             "IPitf TypeEncp Idle IP address      ATM address\n";
918
919         if (v == SEQ_START_TOKEN) {
920                 seq_puts(seq, atm_arp_banner);
921         } else {
922                 struct clip_seq_state *state = seq->private;
923                 struct neighbour *n = v;
924                 struct clip_vcc *vcc = state->vcc;
925
926                 atmarp_info(seq, n->dev, NEIGH2ENTRY(n), vcc);
927         }
928         return 0;
929 }
930
931 static struct seq_operations arp_seq_ops = {
932         .start  = clip_seq_start,
933         .next   = neigh_seq_next,
934         .stop   = neigh_seq_stop,
935         .show   = clip_seq_show,
936 };
937
938 static int arp_seq_open(struct inode *inode, struct file *file)
939 {
940         struct clip_seq_state *state;
941         struct seq_file *seq;
942         int rc = -EAGAIN;
943
944         state = kzalloc(sizeof(*state), GFP_KERNEL);
945         if (!state) {
946                 rc = -ENOMEM;
947                 goto out_kfree;
948         }
949         state->ns.neigh_sub_iter = clip_seq_sub_iter;
950
951         rc = seq_open(file, &arp_seq_ops);
952         if (rc)
953                 goto out_kfree;
954
955         seq = file->private_data;
956         seq->private = state;
957 out:
958         return rc;
959
960 out_kfree:
961         kfree(state);
962         goto out;
963 }
964
965 static const struct file_operations arp_seq_fops = {
966         .open           = arp_seq_open,
967         .read           = seq_read,
968         .llseek         = seq_lseek,
969         .release        = seq_release_private,
970         .owner          = THIS_MODULE
971 };
972 #endif
973
974 static int __init atm_clip_init(void)
975 {
976         neigh_table_init_no_netlink(&clip_tbl);
977
978         clip_tbl_hook = &clip_tbl;
979         register_atm_ioctl(&clip_ioctl_ops);
980         register_netdevice_notifier(&clip_dev_notifier);
981         register_inetaddr_notifier(&clip_inet_notifier);
982
983         setup_timer(&idle_timer, idle_timer_check, 0);
984
985 #ifdef CONFIG_PROC_FS
986         {
987                 struct proc_dir_entry *p;
988
989                 p = create_proc_entry("arp", S_IRUGO, atm_proc_root);
990                 if (p)
991                         p->proc_fops = &arp_seq_fops;
992         }
993 #endif
994
995         return 0;
996 }
997
998 static void __exit atm_clip_exit(void)
999 {
1000         struct net_device *dev, *next;
1001
1002         remove_proc_entry("arp", atm_proc_root);
1003
1004         unregister_inetaddr_notifier(&clip_inet_notifier);
1005         unregister_netdevice_notifier(&clip_dev_notifier);
1006
1007         deregister_atm_ioctl(&clip_ioctl_ops);
1008
1009         /* First, stop the idle timer, so it stops banging
1010          * on the table.
1011          */
1012         del_timer_sync(&idle_timer);
1013
1014         /* Next, purge the table, so that the device
1015          * unregister loop below does not hang due to
1016          * device references remaining in the table.
1017          */
1018         neigh_ifdown(&clip_tbl, NULL);
1019
1020         dev = clip_devs;
1021         while (dev) {
1022                 next = PRIV(dev)->next;
1023                 unregister_netdev(dev);
1024                 free_netdev(dev);
1025                 dev = next;
1026         }
1027
1028         /* Now it is safe to fully shutdown whole table. */
1029         neigh_table_clear(&clip_tbl);
1030
1031         clip_tbl_hook = NULL;
1032 }
1033
1034 module_init(atm_clip_init);
1035 module_exit(atm_clip_exit);
1036 MODULE_AUTHOR("Werner Almesberger");
1037 MODULE_DESCRIPTION("Classical/IP over ATM interface");
1038 MODULE_LICENSE("GPL");