neigh: Pass neighbour entry to output ops.
[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 #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 <linux/slab.h>
34 #include <net/route.h> /* for struct rtable and routing */
35 #include <net/icmp.h> /* icmp_send */
36 #include <linux/param.h> /* for HZ */
37 #include <linux/uaccess.h>
38 #include <asm/byteorder.h> /* for htons etc. */
39 #include <asm/system.h> /* save/restore_flags */
40 #include <asm/atomic.h>
41
42 #include "common.h"
43 #include "resources.h"
44 #include <net/atmclip.h>
45
46 static struct net_device *clip_devs;
47 static struct atm_vcc *atmarpd;
48 static struct neigh_table clip_tbl;
49 static struct timer_list idle_timer;
50
51 static int to_atmarpd(enum atmarp_ctrl_type type, int itf, __be32 ip)
52 {
53         struct sock *sk;
54         struct atmarp_ctrl *ctrl;
55         struct sk_buff *skb;
56
57         pr_debug("(%d)\n", type);
58         if (!atmarpd)
59                 return -EUNATCH;
60         skb = alloc_skb(sizeof(struct atmarp_ctrl), GFP_ATOMIC);
61         if (!skb)
62                 return -ENOMEM;
63         ctrl = (struct atmarp_ctrl *)skb_put(skb, sizeof(struct atmarp_ctrl));
64         ctrl->type = type;
65         ctrl->itf_num = itf;
66         ctrl->ip = ip;
67         atm_force_charge(atmarpd, skb->truesize);
68
69         sk = sk_atm(atmarpd);
70         skb_queue_tail(&sk->sk_receive_queue, skb);
71         sk->sk_data_ready(sk, skb->len);
72         return 0;
73 }
74
75 static void link_vcc(struct clip_vcc *clip_vcc, struct atmarp_entry *entry)
76 {
77         pr_debug("%p to entry %p (neigh %p)\n", clip_vcc, entry, entry->neigh);
78         clip_vcc->entry = entry;
79         clip_vcc->xoff = 0;     /* @@@ may overrun buffer by one packet */
80         clip_vcc->next = entry->vccs;
81         entry->vccs = clip_vcc;
82         entry->neigh->used = jiffies;
83 }
84
85 static void unlink_clip_vcc(struct clip_vcc *clip_vcc)
86 {
87         struct atmarp_entry *entry = clip_vcc->entry;
88         struct clip_vcc **walk;
89
90         if (!entry) {
91                 pr_crit("!clip_vcc->entry (clip_vcc %p)\n", clip_vcc);
92                 return;
93         }
94         netif_tx_lock_bh(entry->neigh->dev);    /* block clip_start_xmit() */
95         entry->neigh->used = jiffies;
96         for (walk = &entry->vccs; *walk; walk = &(*walk)->next)
97                 if (*walk == clip_vcc) {
98                         int error;
99
100                         *walk = clip_vcc->next; /* atomic */
101                         clip_vcc->entry = NULL;
102                         if (clip_vcc->xoff)
103                                 netif_wake_queue(entry->neigh->dev);
104                         if (entry->vccs)
105                                 goto out;
106                         entry->expires = jiffies - 1;
107                         /* force resolution or expiration */
108                         error = neigh_update(entry->neigh, NULL, NUD_NONE,
109                                              NEIGH_UPDATE_F_ADMIN);
110                         if (error)
111                                 pr_crit("neigh_update failed with %d\n", error);
112                         goto out;
113                 }
114         pr_crit("ATMARP: failed (entry %p, vcc 0x%p)\n", entry, clip_vcc);
115 out:
116         netif_tx_unlock_bh(entry->neigh->dev);
117 }
118
119 /* The neighbour entry n->lock is held. */
120 static int neigh_check_cb(struct neighbour *n)
121 {
122         struct atmarp_entry *entry = NEIGH2ENTRY(n);
123         struct clip_vcc *cv;
124
125         for (cv = entry->vccs; cv; cv = cv->next) {
126                 unsigned long exp = cv->last_use + cv->idle_timeout;
127
128                 if (cv->idle_timeout && time_after(jiffies, exp)) {
129                         pr_debug("releasing vcc %p->%p of entry %p\n",
130                                  cv, cv->vcc, entry);
131                         vcc_release_async(cv->vcc, -ETIMEDOUT);
132                 }
133         }
134
135         if (entry->vccs || time_before(jiffies, entry->expires))
136                 return 0;
137
138         if (atomic_read(&n->refcnt) > 1) {
139                 struct sk_buff *skb;
140
141                 pr_debug("destruction postponed with ref %d\n",
142                          atomic_read(&n->refcnt));
143
144                 while ((skb = skb_dequeue(&n->arp_queue)) != NULL)
145                         dev_kfree_skb(skb);
146
147                 return 0;
148         }
149
150         pr_debug("expired neigh %p\n", n);
151         return 1;
152 }
153
154 static void idle_timer_check(unsigned long dummy)
155 {
156         write_lock(&clip_tbl.lock);
157         __neigh_for_each_release(&clip_tbl, neigh_check_cb);
158         mod_timer(&idle_timer, jiffies + CLIP_CHECK_INTERVAL * HZ);
159         write_unlock(&clip_tbl.lock);
160 }
161
162 static int clip_arp_rcv(struct sk_buff *skb)
163 {
164         struct atm_vcc *vcc;
165
166         pr_debug("\n");
167         vcc = ATM_SKB(skb)->vcc;
168         if (!vcc || !atm_charge(vcc, skb->truesize)) {
169                 dev_kfree_skb_any(skb);
170                 return 0;
171         }
172         pr_debug("pushing to %p\n", vcc);
173         pr_debug("using %p\n", CLIP_VCC(vcc)->old_push);
174         CLIP_VCC(vcc)->old_push(vcc, skb);
175         return 0;
176 }
177
178 static const unsigned char llc_oui[] = {
179         0xaa,   /* DSAP: non-ISO */
180         0xaa,   /* SSAP: non-ISO */
181         0x03,   /* Ctrl: Unnumbered Information Command PDU */
182         0x00,   /* OUI: EtherType */
183         0x00,
184         0x00
185 };
186
187 static void clip_push(struct atm_vcc *vcc, struct sk_buff *skb)
188 {
189         struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
190
191         pr_debug("\n");
192         if (!skb) {
193                 pr_debug("removing VCC %p\n", clip_vcc);
194                 if (clip_vcc->entry)
195                         unlink_clip_vcc(clip_vcc);
196                 clip_vcc->old_push(vcc, NULL);  /* pass on the bad news */
197                 kfree(clip_vcc);
198                 return;
199         }
200         atm_return(vcc, skb->truesize);
201         skb->dev = clip_vcc->entry ? clip_vcc->entry->neigh->dev : clip_devs;
202         /* clip_vcc->entry == NULL if we don't have an IP address yet */
203         if (!skb->dev) {
204                 dev_kfree_skb_any(skb);
205                 return;
206         }
207         ATM_SKB(skb)->vcc = vcc;
208         skb_reset_mac_header(skb);
209         if (!clip_vcc->encap ||
210             skb->len < RFC1483LLC_LEN ||
211             memcmp(skb->data, llc_oui, sizeof(llc_oui)))
212                 skb->protocol = htons(ETH_P_IP);
213         else {
214                 skb->protocol = ((__be16 *)skb->data)[3];
215                 skb_pull(skb, RFC1483LLC_LEN);
216                 if (skb->protocol == htons(ETH_P_ARP)) {
217                         skb->dev->stats.rx_packets++;
218                         skb->dev->stats.rx_bytes += skb->len;
219                         clip_arp_rcv(skb);
220                         return;
221                 }
222         }
223         clip_vcc->last_use = jiffies;
224         skb->dev->stats.rx_packets++;
225         skb->dev->stats.rx_bytes += skb->len;
226         memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
227         netif_rx(skb);
228 }
229
230 /*
231  * Note: these spinlocks _must_not_ block on non-SMP. The only goal is that
232  * clip_pop is atomic with respect to the critical section in clip_start_xmit.
233  */
234
235 static void clip_pop(struct atm_vcc *vcc, struct sk_buff *skb)
236 {
237         struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
238         struct net_device *dev = skb->dev;
239         int old;
240         unsigned long flags;
241
242         pr_debug("(vcc %p)\n", vcc);
243         clip_vcc->old_pop(vcc, skb);
244         /* skb->dev == NULL in outbound ARP packets */
245         if (!dev)
246                 return;
247         spin_lock_irqsave(&PRIV(dev)->xoff_lock, flags);
248         if (atm_may_send(vcc, 0)) {
249                 old = xchg(&clip_vcc->xoff, 0);
250                 if (old)
251                         netif_wake_queue(dev);
252         }
253         spin_unlock_irqrestore(&PRIV(dev)->xoff_lock, flags);
254 }
255
256 static void clip_neigh_solicit(struct neighbour *neigh, struct sk_buff *skb)
257 {
258         pr_debug("(neigh %p, skb %p)\n", neigh, skb);
259         to_atmarpd(act_need, PRIV(neigh->dev)->number, NEIGH2ENTRY(neigh)->ip);
260 }
261
262 static void clip_neigh_error(struct neighbour *neigh, struct sk_buff *skb)
263 {
264 #ifndef CONFIG_ATM_CLIP_NO_ICMP
265         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
266 #endif
267         kfree_skb(skb);
268 }
269
270 static const struct neigh_ops clip_neigh_ops = {
271         .family =               AF_INET,
272         .solicit =              clip_neigh_solicit,
273         .error_report =         clip_neigh_error,
274         .output =               neigh_direct_output,
275         .connected_output =     neigh_direct_output,
276 };
277
278 static int clip_constructor(struct neighbour *neigh)
279 {
280         struct atmarp_entry *entry = NEIGH2ENTRY(neigh);
281         struct net_device *dev = neigh->dev;
282         struct in_device *in_dev;
283         struct neigh_parms *parms;
284
285         pr_debug("(neigh %p, entry %p)\n", neigh, entry);
286         neigh->type = inet_addr_type(&init_net, entry->ip);
287         if (neigh->type != RTN_UNICAST)
288                 return -EINVAL;
289
290         rcu_read_lock();
291         in_dev = __in_dev_get_rcu(dev);
292         if (!in_dev) {
293                 rcu_read_unlock();
294                 return -EINVAL;
295         }
296
297         parms = in_dev->arp_parms;
298         __neigh_parms_put(neigh->parms);
299         neigh->parms = neigh_parms_clone(parms);
300         rcu_read_unlock();
301
302         neigh->ops = &clip_neigh_ops;
303         neigh->output = neigh->nud_state & NUD_VALID ?
304             neigh->ops->connected_output : neigh->ops->output;
305         entry->neigh = neigh;
306         entry->vccs = NULL;
307         entry->expires = jiffies - 1;
308         return 0;
309 }
310
311 static u32 clip_hash(const void *pkey, const struct net_device *dev, __u32 rnd)
312 {
313         return jhash_2words(*(u32 *) pkey, dev->ifindex, rnd);
314 }
315
316 static struct neigh_table clip_tbl = {
317         .family         = AF_INET,
318         .entry_size     = sizeof(struct neighbour)+sizeof(struct atmarp_entry),
319         .key_len        = 4,
320         .hash           = clip_hash,
321         .constructor    = clip_constructor,
322         .id             = "clip_arp_cache",
323
324         /* parameters are copied from ARP ... */
325         .parms = {
326                 .tbl                    = &clip_tbl,
327                 .base_reachable_time    = 30 * HZ,
328                 .retrans_time           = 1 * HZ,
329                 .gc_staletime           = 60 * HZ,
330                 .reachable_time         = 30 * HZ,
331                 .delay_probe_time       = 5 * HZ,
332                 .queue_len              = 3,
333                 .ucast_probes           = 3,
334                 .mcast_probes           = 3,
335                 .anycast_delay          = 1 * HZ,
336                 .proxy_delay            = (8 * HZ) / 10,
337                 .proxy_qlen             = 64,
338                 .locktime               = 1 * HZ,
339         },
340         .gc_interval    = 30 * HZ,
341         .gc_thresh1     = 128,
342         .gc_thresh2     = 512,
343         .gc_thresh3     = 1024,
344 };
345
346 /* @@@ copy bh locking from arp.c -- need to bh-enable atm code before */
347
348 /*
349  * We play with the resolve flag: 0 and 1 have the usual meaning, but -1 means
350  * to allocate the neighbour entry but not to ask atmarpd for resolution. Also,
351  * don't increment the usage count. This is used to create entries in
352  * clip_setentry.
353  */
354
355 static int clip_encap(struct atm_vcc *vcc, int mode)
356 {
357         CLIP_VCC(vcc)->encap = mode;
358         return 0;
359 }
360
361 static netdev_tx_t clip_start_xmit(struct sk_buff *skb,
362                                    struct net_device *dev)
363 {
364         struct clip_priv *clip_priv = PRIV(dev);
365         struct atmarp_entry *entry;
366         struct atm_vcc *vcc;
367         int old;
368         unsigned long flags;
369
370         pr_debug("(skb %p)\n", skb);
371         if (!skb_dst(skb)) {
372                 pr_err("skb_dst(skb) == NULL\n");
373                 dev_kfree_skb(skb);
374                 dev->stats.tx_dropped++;
375                 return NETDEV_TX_OK;
376         }
377         if (!skb_dst(skb)->neighbour) {
378 #if 0
379                 skb_dst(skb)->neighbour = clip_find_neighbour(skb_dst(skb), 1);
380                 if (!skb_dst(skb)->neighbour) {
381                         dev_kfree_skb(skb);     /* lost that one */
382                         dev->stats.tx_dropped++;
383                         return 0;
384                 }
385 #endif
386                 pr_err("NO NEIGHBOUR !\n");
387                 dev_kfree_skb(skb);
388                 dev->stats.tx_dropped++;
389                 return NETDEV_TX_OK;
390         }
391         entry = NEIGH2ENTRY(skb_dst(skb)->neighbour);
392         if (!entry->vccs) {
393                 if (time_after(jiffies, entry->expires)) {
394                         /* should be resolved */
395                         entry->expires = jiffies + ATMARP_RETRY_DELAY * HZ;
396                         to_atmarpd(act_need, PRIV(dev)->number, entry->ip);
397                 }
398                 if (entry->neigh->arp_queue.qlen < ATMARP_MAX_UNRES_PACKETS)
399                         skb_queue_tail(&entry->neigh->arp_queue, skb);
400                 else {
401                         dev_kfree_skb(skb);
402                         dev->stats.tx_dropped++;
403                 }
404                 return NETDEV_TX_OK;
405         }
406         pr_debug("neigh %p, vccs %p\n", entry, entry->vccs);
407         ATM_SKB(skb)->vcc = vcc = entry->vccs->vcc;
408         pr_debug("using neighbour %p, vcc %p\n", skb_dst(skb)->neighbour, vcc);
409         if (entry->vccs->encap) {
410                 void *here;
411
412                 here = skb_push(skb, RFC1483LLC_LEN);
413                 memcpy(here, llc_oui, sizeof(llc_oui));
414                 ((__be16 *) here)[3] = skb->protocol;
415         }
416         atomic_add(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
417         ATM_SKB(skb)->atm_options = vcc->atm_options;
418         entry->vccs->last_use = jiffies;
419         pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, vcc, vcc->dev);
420         old = xchg(&entry->vccs->xoff, 1);      /* assume XOFF ... */
421         if (old) {
422                 pr_warning("XOFF->XOFF transition\n");
423                 return NETDEV_TX_OK;
424         }
425         dev->stats.tx_packets++;
426         dev->stats.tx_bytes += skb->len;
427         vcc->send(vcc, skb);
428         if (atm_may_send(vcc, 0)) {
429                 entry->vccs->xoff = 0;
430                 return NETDEV_TX_OK;
431         }
432         spin_lock_irqsave(&clip_priv->xoff_lock, flags);
433         netif_stop_queue(dev);  /* XOFF -> throttle immediately */
434         barrier();
435         if (!entry->vccs->xoff)
436                 netif_start_queue(dev);
437         /* Oh, we just raced with clip_pop. netif_start_queue should be
438            good enough, because nothing should really be asleep because
439            of the brief netif_stop_queue. If this isn't true or if it
440            changes, use netif_wake_queue instead. */
441         spin_unlock_irqrestore(&clip_priv->xoff_lock, flags);
442         return NETDEV_TX_OK;
443 }
444
445 static int clip_mkip(struct atm_vcc *vcc, int timeout)
446 {
447         struct sk_buff_head *rq, queue;
448         struct clip_vcc *clip_vcc;
449         struct sk_buff *skb, *tmp;
450         unsigned long flags;
451
452         if (!vcc->push)
453                 return -EBADFD;
454         clip_vcc = kmalloc(sizeof(struct clip_vcc), GFP_KERNEL);
455         if (!clip_vcc)
456                 return -ENOMEM;
457         pr_debug("%p vcc %p\n", clip_vcc, vcc);
458         clip_vcc->vcc = vcc;
459         vcc->user_back = clip_vcc;
460         set_bit(ATM_VF_IS_CLIP, &vcc->flags);
461         clip_vcc->entry = NULL;
462         clip_vcc->xoff = 0;
463         clip_vcc->encap = 1;
464         clip_vcc->last_use = jiffies;
465         clip_vcc->idle_timeout = timeout * HZ;
466         clip_vcc->old_push = vcc->push;
467         clip_vcc->old_pop = vcc->pop;
468         vcc->push = clip_push;
469         vcc->pop = clip_pop;
470
471         __skb_queue_head_init(&queue);
472         rq = &sk_atm(vcc)->sk_receive_queue;
473
474         spin_lock_irqsave(&rq->lock, flags);
475         skb_queue_splice_init(rq, &queue);
476         spin_unlock_irqrestore(&rq->lock, flags);
477
478         /* re-process everything received between connection setup and MKIP */
479         skb_queue_walk_safe(&queue, skb, tmp) {
480                 if (!clip_devs) {
481                         atm_return(vcc, skb->truesize);
482                         kfree_skb(skb);
483                 } else {
484                         struct net_device *dev = skb->dev;
485                         unsigned int len = skb->len;
486
487                         skb_get(skb);
488                         clip_push(vcc, skb);
489                         dev->stats.rx_packets--;
490                         dev->stats.rx_bytes -= len;
491                         kfree_skb(skb);
492                 }
493         }
494         return 0;
495 }
496
497 static int clip_setentry(struct atm_vcc *vcc, __be32 ip)
498 {
499         struct neighbour *neigh;
500         struct atmarp_entry *entry;
501         int error;
502         struct clip_vcc *clip_vcc;
503         struct rtable *rt;
504
505         if (vcc->push != clip_push) {
506                 pr_warning("non-CLIP VCC\n");
507                 return -EBADF;
508         }
509         clip_vcc = CLIP_VCC(vcc);
510         if (!ip) {
511                 if (!clip_vcc->entry) {
512                         pr_err("hiding hidden ATMARP entry\n");
513                         return 0;
514                 }
515                 pr_debug("remove\n");
516                 unlink_clip_vcc(clip_vcc);
517                 return 0;
518         }
519         rt = ip_route_output(&init_net, ip, 0, 1, 0);
520         if (IS_ERR(rt))
521                 return PTR_ERR(rt);
522         neigh = __neigh_lookup(&clip_tbl, &ip, rt->dst.dev, 1);
523         ip_rt_put(rt);
524         if (!neigh)
525                 return -ENOMEM;
526         entry = NEIGH2ENTRY(neigh);
527         if (entry != clip_vcc->entry) {
528                 if (!clip_vcc->entry)
529                         pr_debug("add\n");
530                 else {
531                         pr_debug("update\n");
532                         unlink_clip_vcc(clip_vcc);
533                 }
534                 link_vcc(clip_vcc, entry);
535         }
536         error = neigh_update(neigh, llc_oui, NUD_PERMANENT,
537                              NEIGH_UPDATE_F_OVERRIDE | NEIGH_UPDATE_F_ADMIN);
538         neigh_release(neigh);
539         return error;
540 }
541
542 static const struct net_device_ops clip_netdev_ops = {
543         .ndo_start_xmit = clip_start_xmit,
544 };
545
546 static void clip_setup(struct net_device *dev)
547 {
548         dev->netdev_ops = &clip_netdev_ops;
549         dev->type = ARPHRD_ATM;
550         dev->hard_header_len = RFC1483LLC_LEN;
551         dev->mtu = RFC1626_MTU;
552         dev->tx_queue_len = 100;        /* "normal" queue (packets) */
553         /* When using a "real" qdisc, the qdisc determines the queue */
554         /* length. tx_queue_len is only used for the default case, */
555         /* without any more elaborate queuing. 100 is a reasonable */
556         /* compromise between decent burst-tolerance and protection */
557         /* against memory hogs. */
558         dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
559 }
560
561 static int clip_create(int number)
562 {
563         struct net_device *dev;
564         struct clip_priv *clip_priv;
565         int error;
566
567         if (number != -1) {
568                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
569                         if (PRIV(dev)->number == number)
570                                 return -EEXIST;
571         } else {
572                 number = 0;
573                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
574                         if (PRIV(dev)->number >= number)
575                                 number = PRIV(dev)->number + 1;
576         }
577         dev = alloc_netdev(sizeof(struct clip_priv), "", clip_setup);
578         if (!dev)
579                 return -ENOMEM;
580         clip_priv = PRIV(dev);
581         sprintf(dev->name, "atm%d", number);
582         spin_lock_init(&clip_priv->xoff_lock);
583         clip_priv->number = number;
584         error = register_netdev(dev);
585         if (error) {
586                 free_netdev(dev);
587                 return error;
588         }
589         clip_priv->next = clip_devs;
590         clip_devs = dev;
591         pr_debug("registered (net:%s)\n", dev->name);
592         return number;
593 }
594
595 static int clip_device_event(struct notifier_block *this, unsigned long event,
596                              void *arg)
597 {
598         struct net_device *dev = arg;
599
600         if (!net_eq(dev_net(dev), &init_net))
601                 return NOTIFY_DONE;
602
603         if (event == NETDEV_UNREGISTER) {
604                 neigh_ifdown(&clip_tbl, dev);
605                 return NOTIFY_DONE;
606         }
607
608         /* ignore non-CLIP devices */
609         if (dev->type != ARPHRD_ATM || dev->netdev_ops != &clip_netdev_ops)
610                 return NOTIFY_DONE;
611
612         switch (event) {
613         case NETDEV_UP:
614                 pr_debug("NETDEV_UP\n");
615                 to_atmarpd(act_up, PRIV(dev)->number, 0);
616                 break;
617         case NETDEV_GOING_DOWN:
618                 pr_debug("NETDEV_DOWN\n");
619                 to_atmarpd(act_down, PRIV(dev)->number, 0);
620                 break;
621         case NETDEV_CHANGE:
622         case NETDEV_CHANGEMTU:
623                 pr_debug("NETDEV_CHANGE*\n");
624                 to_atmarpd(act_change, PRIV(dev)->number, 0);
625                 break;
626         }
627         return NOTIFY_DONE;
628 }
629
630 static int clip_inet_event(struct notifier_block *this, unsigned long event,
631                            void *ifa)
632 {
633         struct in_device *in_dev;
634
635         in_dev = ((struct in_ifaddr *)ifa)->ifa_dev;
636         /*
637          * Transitions are of the down-change-up type, so it's sufficient to
638          * handle the change on up.
639          */
640         if (event != NETDEV_UP)
641                 return NOTIFY_DONE;
642         return clip_device_event(this, NETDEV_CHANGE, in_dev->dev);
643 }
644
645 static struct notifier_block clip_dev_notifier = {
646         .notifier_call = clip_device_event,
647 };
648
649
650
651 static struct notifier_block clip_inet_notifier = {
652         .notifier_call = clip_inet_event,
653 };
654
655
656
657 static void atmarpd_close(struct atm_vcc *vcc)
658 {
659         pr_debug("\n");
660
661         rtnl_lock();
662         atmarpd = NULL;
663         skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
664         rtnl_unlock();
665
666         pr_debug("(done)\n");
667         module_put(THIS_MODULE);
668 }
669
670 static struct atmdev_ops atmarpd_dev_ops = {
671         .close = atmarpd_close
672 };
673
674
675 static struct atm_dev atmarpd_dev = {
676         .ops =                  &atmarpd_dev_ops,
677         .type =                 "arpd",
678         .number =               999,
679         .lock =                 __SPIN_LOCK_UNLOCKED(atmarpd_dev.lock)
680 };
681
682
683 static int atm_init_atmarp(struct atm_vcc *vcc)
684 {
685         rtnl_lock();
686         if (atmarpd) {
687                 rtnl_unlock();
688                 return -EADDRINUSE;
689         }
690
691         mod_timer(&idle_timer, jiffies + CLIP_CHECK_INTERVAL * HZ);
692
693         atmarpd = vcc;
694         set_bit(ATM_VF_META, &vcc->flags);
695         set_bit(ATM_VF_READY, &vcc->flags);
696             /* allow replies and avoid getting closed if signaling dies */
697         vcc->dev = &atmarpd_dev;
698         vcc_insert_socket(sk_atm(vcc));
699         vcc->push = NULL;
700         vcc->pop = NULL; /* crash */
701         vcc->push_oam = NULL; /* crash */
702         rtnl_unlock();
703         return 0;
704 }
705
706 static int clip_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
707 {
708         struct atm_vcc *vcc = ATM_SD(sock);
709         int err = 0;
710
711         switch (cmd) {
712         case SIOCMKCLIP:
713         case ATMARPD_CTRL:
714         case ATMARP_MKIP:
715         case ATMARP_SETENTRY:
716         case ATMARP_ENCAP:
717                 if (!capable(CAP_NET_ADMIN))
718                         return -EPERM;
719                 break;
720         default:
721                 return -ENOIOCTLCMD;
722         }
723
724         switch (cmd) {
725         case SIOCMKCLIP:
726                 err = clip_create(arg);
727                 break;
728         case ATMARPD_CTRL:
729                 err = atm_init_atmarp(vcc);
730                 if (!err) {
731                         sock->state = SS_CONNECTED;
732                         __module_get(THIS_MODULE);
733                 }
734                 break;
735         case ATMARP_MKIP:
736                 err = clip_mkip(vcc, arg);
737                 break;
738         case ATMARP_SETENTRY:
739                 err = clip_setentry(vcc, (__force __be32)arg);
740                 break;
741         case ATMARP_ENCAP:
742                 err = clip_encap(vcc, arg);
743                 break;
744         }
745         return err;
746 }
747
748 static struct atm_ioctl clip_ioctl_ops = {
749         .owner = THIS_MODULE,
750         .ioctl = clip_ioctl,
751 };
752
753 #ifdef CONFIG_PROC_FS
754
755 static void svc_addr(struct seq_file *seq, struct sockaddr_atmsvc *addr)
756 {
757         static int code[] = { 1, 2, 10, 6, 1, 0 };
758         static int e164[] = { 1, 8, 4, 6, 1, 0 };
759
760         if (*addr->sas_addr.pub) {
761                 seq_printf(seq, "%s", addr->sas_addr.pub);
762                 if (*addr->sas_addr.prv)
763                         seq_putc(seq, '+');
764         } else if (!*addr->sas_addr.prv) {
765                 seq_printf(seq, "%s", "(none)");
766                 return;
767         }
768         if (*addr->sas_addr.prv) {
769                 unsigned char *prv = addr->sas_addr.prv;
770                 int *fields;
771                 int i, j;
772
773                 fields = *prv == ATM_AFI_E164 ? e164 : code;
774                 for (i = 0; fields[i]; i++) {
775                         for (j = fields[i]; j; j--)
776                                 seq_printf(seq, "%02X", *prv++);
777                         if (fields[i + 1])
778                                 seq_putc(seq, '.');
779                 }
780         }
781 }
782
783 /* This means the neighbour entry has no attached VCC objects. */
784 #define SEQ_NO_VCC_TOKEN        ((void *) 2)
785
786 static void atmarp_info(struct seq_file *seq, struct net_device *dev,
787                         struct atmarp_entry *entry, struct clip_vcc *clip_vcc)
788 {
789         unsigned long exp;
790         char buf[17];
791         int svc, llc, off;
792
793         svc = ((clip_vcc == SEQ_NO_VCC_TOKEN) ||
794                (sk_atm(clip_vcc->vcc)->sk_family == AF_ATMSVC));
795
796         llc = ((clip_vcc == SEQ_NO_VCC_TOKEN) || clip_vcc->encap);
797
798         if (clip_vcc == SEQ_NO_VCC_TOKEN)
799                 exp = entry->neigh->used;
800         else
801                 exp = clip_vcc->last_use;
802
803         exp = (jiffies - exp) / HZ;
804
805         seq_printf(seq, "%-6s%-4s%-4s%5ld ",
806                    dev->name, svc ? "SVC" : "PVC", llc ? "LLC" : "NULL", exp);
807
808         off = scnprintf(buf, sizeof(buf) - 1, "%pI4",
809                         &entry->ip);
810         while (off < 16)
811                 buf[off++] = ' ';
812         buf[off] = '\0';
813         seq_printf(seq, "%s", buf);
814
815         if (clip_vcc == SEQ_NO_VCC_TOKEN) {
816                 if (time_before(jiffies, entry->expires))
817                         seq_printf(seq, "(resolving)\n");
818                 else
819                         seq_printf(seq, "(expired, ref %d)\n",
820                                    atomic_read(&entry->neigh->refcnt));
821         } else if (!svc) {
822                 seq_printf(seq, "%d.%d.%d\n",
823                            clip_vcc->vcc->dev->number,
824                            clip_vcc->vcc->vpi, clip_vcc->vcc->vci);
825         } else {
826                 svc_addr(seq, &clip_vcc->vcc->remote);
827                 seq_putc(seq, '\n');
828         }
829 }
830
831 struct clip_seq_state {
832         /* This member must be first. */
833         struct neigh_seq_state ns;
834
835         /* Local to clip specific iteration. */
836         struct clip_vcc *vcc;
837 };
838
839 static struct clip_vcc *clip_seq_next_vcc(struct atmarp_entry *e,
840                                           struct clip_vcc *curr)
841 {
842         if (!curr) {
843                 curr = e->vccs;
844                 if (!curr)
845                         return SEQ_NO_VCC_TOKEN;
846                 return curr;
847         }
848         if (curr == SEQ_NO_VCC_TOKEN)
849                 return NULL;
850
851         curr = curr->next;
852
853         return curr;
854 }
855
856 static void *clip_seq_vcc_walk(struct clip_seq_state *state,
857                                struct atmarp_entry *e, loff_t * pos)
858 {
859         struct clip_vcc *vcc = state->vcc;
860
861         vcc = clip_seq_next_vcc(e, vcc);
862         if (vcc && pos != NULL) {
863                 while (*pos) {
864                         vcc = clip_seq_next_vcc(e, vcc);
865                         if (!vcc)
866                                 break;
867                         --(*pos);
868                 }
869         }
870         state->vcc = vcc;
871
872         return vcc;
873 }
874
875 static void *clip_seq_sub_iter(struct neigh_seq_state *_state,
876                                struct neighbour *n, loff_t * pos)
877 {
878         struct clip_seq_state *state = (struct clip_seq_state *)_state;
879
880         return clip_seq_vcc_walk(state, NEIGH2ENTRY(n), pos);
881 }
882
883 static void *clip_seq_start(struct seq_file *seq, loff_t * pos)
884 {
885         struct clip_seq_state *state = seq->private;
886         state->ns.neigh_sub_iter = clip_seq_sub_iter;
887         return neigh_seq_start(seq, pos, &clip_tbl, NEIGH_SEQ_NEIGH_ONLY);
888 }
889
890 static int clip_seq_show(struct seq_file *seq, void *v)
891 {
892         static char atm_arp_banner[] =
893             "IPitf TypeEncp Idle IP address      ATM address\n";
894
895         if (v == SEQ_START_TOKEN) {
896                 seq_puts(seq, atm_arp_banner);
897         } else {
898                 struct clip_seq_state *state = seq->private;
899                 struct neighbour *n = v;
900                 struct clip_vcc *vcc = state->vcc;
901
902                 atmarp_info(seq, n->dev, NEIGH2ENTRY(n), vcc);
903         }
904         return 0;
905 }
906
907 static const struct seq_operations arp_seq_ops = {
908         .start  = clip_seq_start,
909         .next   = neigh_seq_next,
910         .stop   = neigh_seq_stop,
911         .show   = clip_seq_show,
912 };
913
914 static int arp_seq_open(struct inode *inode, struct file *file)
915 {
916         return seq_open_net(inode, file, &arp_seq_ops,
917                             sizeof(struct clip_seq_state));
918 }
919
920 static const struct file_operations arp_seq_fops = {
921         .open           = arp_seq_open,
922         .read           = seq_read,
923         .llseek         = seq_lseek,
924         .release        = seq_release_net,
925         .owner          = THIS_MODULE
926 };
927 #endif
928
929 static void atm_clip_exit_noproc(void);
930
931 static int __init atm_clip_init(void)
932 {
933         neigh_table_init_no_netlink(&clip_tbl);
934
935         clip_tbl_hook = &clip_tbl;
936         register_atm_ioctl(&clip_ioctl_ops);
937         register_netdevice_notifier(&clip_dev_notifier);
938         register_inetaddr_notifier(&clip_inet_notifier);
939
940         setup_timer(&idle_timer, idle_timer_check, 0);
941
942 #ifdef CONFIG_PROC_FS
943         {
944                 struct proc_dir_entry *p;
945
946                 p = proc_create("arp", S_IRUGO, atm_proc_root, &arp_seq_fops);
947                 if (!p) {
948                         pr_err("Unable to initialize /proc/net/atm/arp\n");
949                         atm_clip_exit_noproc();
950                         return -ENOMEM;
951                 }
952         }
953 #endif
954
955         return 0;
956 }
957
958 static void atm_clip_exit_noproc(void)
959 {
960         struct net_device *dev, *next;
961
962         unregister_inetaddr_notifier(&clip_inet_notifier);
963         unregister_netdevice_notifier(&clip_dev_notifier);
964
965         deregister_atm_ioctl(&clip_ioctl_ops);
966
967         /* First, stop the idle timer, so it stops banging
968          * on the table.
969          */
970         del_timer_sync(&idle_timer);
971
972         /* Next, purge the table, so that the device
973          * unregister loop below does not hang due to
974          * device references remaining in the table.
975          */
976         neigh_ifdown(&clip_tbl, NULL);
977
978         dev = clip_devs;
979         while (dev) {
980                 next = PRIV(dev)->next;
981                 unregister_netdev(dev);
982                 free_netdev(dev);
983                 dev = next;
984         }
985
986         /* Now it is safe to fully shutdown whole table. */
987         neigh_table_clear(&clip_tbl);
988
989         clip_tbl_hook = NULL;
990 }
991
992 static void __exit atm_clip_exit(void)
993 {
994         remove_proc_entry("arp", atm_proc_root);
995
996         atm_clip_exit_noproc();
997 }
998
999 module_init(atm_clip_init);
1000 module_exit(atm_clip_exit);
1001 MODULE_AUTHOR("Werner Almesberger");
1002 MODULE_DESCRIPTION("Classical/IP over ATM interface");
1003 MODULE_LICENSE("GPL");