neigh: Do not set tbl->entry_size in ipv4/ipv6 neigh tables.
[~shefty/rdma-dev.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 <linux/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
193         if (!clip_devs) {
194                 atm_return(vcc, skb->truesize);
195                 kfree_skb(skb);
196                 return;
197         }
198
199         if (!skb) {
200                 pr_debug("removing VCC %p\n", clip_vcc);
201                 if (clip_vcc->entry)
202                         unlink_clip_vcc(clip_vcc);
203                 clip_vcc->old_push(vcc, NULL);  /* pass on the bad news */
204                 kfree(clip_vcc);
205                 return;
206         }
207         atm_return(vcc, skb->truesize);
208         skb->dev = clip_vcc->entry ? clip_vcc->entry->neigh->dev : clip_devs;
209         /* clip_vcc->entry == NULL if we don't have an IP address yet */
210         if (!skb->dev) {
211                 dev_kfree_skb_any(skb);
212                 return;
213         }
214         ATM_SKB(skb)->vcc = vcc;
215         skb_reset_mac_header(skb);
216         if (!clip_vcc->encap ||
217             skb->len < RFC1483LLC_LEN ||
218             memcmp(skb->data, llc_oui, sizeof(llc_oui)))
219                 skb->protocol = htons(ETH_P_IP);
220         else {
221                 skb->protocol = ((__be16 *)skb->data)[3];
222                 skb_pull(skb, RFC1483LLC_LEN);
223                 if (skb->protocol == htons(ETH_P_ARP)) {
224                         skb->dev->stats.rx_packets++;
225                         skb->dev->stats.rx_bytes += skb->len;
226                         clip_arp_rcv(skb);
227                         return;
228                 }
229         }
230         clip_vcc->last_use = jiffies;
231         skb->dev->stats.rx_packets++;
232         skb->dev->stats.rx_bytes += skb->len;
233         memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
234         netif_rx(skb);
235 }
236
237 /*
238  * Note: these spinlocks _must_not_ block on non-SMP. The only goal is that
239  * clip_pop is atomic with respect to the critical section in clip_start_xmit.
240  */
241
242 static void clip_pop(struct atm_vcc *vcc, struct sk_buff *skb)
243 {
244         struct clip_vcc *clip_vcc = CLIP_VCC(vcc);
245         struct net_device *dev = skb->dev;
246         int old;
247         unsigned long flags;
248
249         pr_debug("(vcc %p)\n", vcc);
250         clip_vcc->old_pop(vcc, skb);
251         /* skb->dev == NULL in outbound ARP packets */
252         if (!dev)
253                 return;
254         spin_lock_irqsave(&PRIV(dev)->xoff_lock, flags);
255         if (atm_may_send(vcc, 0)) {
256                 old = xchg(&clip_vcc->xoff, 0);
257                 if (old)
258                         netif_wake_queue(dev);
259         }
260         spin_unlock_irqrestore(&PRIV(dev)->xoff_lock, flags);
261 }
262
263 static void clip_neigh_solicit(struct neighbour *neigh, struct sk_buff *skb)
264 {
265         pr_debug("(neigh %p, skb %p)\n", neigh, skb);
266         to_atmarpd(act_need, PRIV(neigh->dev)->number, NEIGH2ENTRY(neigh)->ip);
267 }
268
269 static void clip_neigh_error(struct neighbour *neigh, struct sk_buff *skb)
270 {
271 #ifndef CONFIG_ATM_CLIP_NO_ICMP
272         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
273 #endif
274         kfree_skb(skb);
275 }
276
277 static const struct neigh_ops clip_neigh_ops = {
278         .family =               AF_INET,
279         .solicit =              clip_neigh_solicit,
280         .error_report =         clip_neigh_error,
281         .output =               neigh_direct_output,
282         .connected_output =     neigh_direct_output,
283 };
284
285 static int clip_constructor(struct neighbour *neigh)
286 {
287         struct atmarp_entry *entry = NEIGH2ENTRY(neigh);
288         struct net_device *dev = neigh->dev;
289         struct in_device *in_dev;
290         struct neigh_parms *parms;
291
292         pr_debug("(neigh %p, entry %p)\n", neigh, entry);
293         neigh->type = inet_addr_type(&init_net, entry->ip);
294         if (neigh->type != RTN_UNICAST)
295                 return -EINVAL;
296
297         rcu_read_lock();
298         in_dev = __in_dev_get_rcu(dev);
299         if (!in_dev) {
300                 rcu_read_unlock();
301                 return -EINVAL;
302         }
303
304         parms = in_dev->arp_parms;
305         __neigh_parms_put(neigh->parms);
306         neigh->parms = neigh_parms_clone(parms);
307         rcu_read_unlock();
308
309         neigh->ops = &clip_neigh_ops;
310         neigh->output = neigh->nud_state & NUD_VALID ?
311             neigh->ops->connected_output : neigh->ops->output;
312         entry->neigh = neigh;
313         entry->vccs = NULL;
314         entry->expires = jiffies - 1;
315         return 0;
316 }
317
318 static u32 clip_hash(const void *pkey, const struct net_device *dev, __u32 rnd)
319 {
320         return jhash_2words(*(u32 *) pkey, dev->ifindex, rnd);
321 }
322
323 static struct neigh_table clip_tbl = {
324         .family         = AF_INET,
325         .key_len        = 4,
326         .hash           = clip_hash,
327         .constructor    = clip_constructor,
328         .id             = "clip_arp_cache",
329
330         /* parameters are copied from ARP ... */
331         .parms = {
332                 .tbl                    = &clip_tbl,
333                 .base_reachable_time    = 30 * HZ,
334                 .retrans_time           = 1 * HZ,
335                 .gc_staletime           = 60 * HZ,
336                 .reachable_time         = 30 * HZ,
337                 .delay_probe_time       = 5 * HZ,
338                 .queue_len_bytes        = 64 * 1024,
339                 .ucast_probes           = 3,
340                 .mcast_probes           = 3,
341                 .anycast_delay          = 1 * HZ,
342                 .proxy_delay            = (8 * HZ) / 10,
343                 .proxy_qlen             = 64,
344                 .locktime               = 1 * HZ,
345         },
346         .gc_interval    = 30 * HZ,
347         .gc_thresh1     = 128,
348         .gc_thresh2     = 512,
349         .gc_thresh3     = 1024,
350 };
351
352 /* @@@ copy bh locking from arp.c -- need to bh-enable atm code before */
353
354 /*
355  * We play with the resolve flag: 0 and 1 have the usual meaning, but -1 means
356  * to allocate the neighbour entry but not to ask atmarpd for resolution. Also,
357  * don't increment the usage count. This is used to create entries in
358  * clip_setentry.
359  */
360
361 static int clip_encap(struct atm_vcc *vcc, int mode)
362 {
363         CLIP_VCC(vcc)->encap = mode;
364         return 0;
365 }
366
367 static netdev_tx_t clip_start_xmit(struct sk_buff *skb,
368                                    struct net_device *dev)
369 {
370         struct clip_priv *clip_priv = PRIV(dev);
371         struct dst_entry *dst = skb_dst(skb);
372         struct atmarp_entry *entry;
373         struct neighbour *n;
374         struct atm_vcc *vcc;
375         int old;
376         unsigned long flags;
377
378         pr_debug("(skb %p)\n", skb);
379         if (!dst) {
380                 pr_err("skb_dst(skb) == NULL\n");
381                 dev_kfree_skb(skb);
382                 dev->stats.tx_dropped++;
383                 return NETDEV_TX_OK;
384         }
385         n = dst_get_neighbour(dst);
386         if (!n) {
387 #if 0
388                 n = clip_find_neighbour(skb_dst(skb), 1);
389                 if (!n) {
390                         dev_kfree_skb(skb);     /* lost that one */
391                         dev->stats.tx_dropped++;
392                         return 0;
393                 }
394                 dst_set_neighbour(dst, n);
395 #endif
396                 pr_err("NO NEIGHBOUR !\n");
397                 dev_kfree_skb(skb);
398                 dev->stats.tx_dropped++;
399                 return NETDEV_TX_OK;
400         }
401         entry = NEIGH2ENTRY(n);
402         if (!entry->vccs) {
403                 if (time_after(jiffies, entry->expires)) {
404                         /* should be resolved */
405                         entry->expires = jiffies + ATMARP_RETRY_DELAY * HZ;
406                         to_atmarpd(act_need, PRIV(dev)->number, entry->ip);
407                 }
408                 if (entry->neigh->arp_queue.qlen < ATMARP_MAX_UNRES_PACKETS)
409                         skb_queue_tail(&entry->neigh->arp_queue, skb);
410                 else {
411                         dev_kfree_skb(skb);
412                         dev->stats.tx_dropped++;
413                 }
414                 return NETDEV_TX_OK;
415         }
416         pr_debug("neigh %p, vccs %p\n", entry, entry->vccs);
417         ATM_SKB(skb)->vcc = vcc = entry->vccs->vcc;
418         pr_debug("using neighbour %p, vcc %p\n", n, vcc);
419         if (entry->vccs->encap) {
420                 void *here;
421
422                 here = skb_push(skb, RFC1483LLC_LEN);
423                 memcpy(here, llc_oui, sizeof(llc_oui));
424                 ((__be16 *) here)[3] = skb->protocol;
425         }
426         atomic_add(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
427         ATM_SKB(skb)->atm_options = vcc->atm_options;
428         entry->vccs->last_use = jiffies;
429         pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, vcc, vcc->dev);
430         old = xchg(&entry->vccs->xoff, 1);      /* assume XOFF ... */
431         if (old) {
432                 pr_warning("XOFF->XOFF transition\n");
433                 return NETDEV_TX_OK;
434         }
435         dev->stats.tx_packets++;
436         dev->stats.tx_bytes += skb->len;
437         vcc->send(vcc, skb);
438         if (atm_may_send(vcc, 0)) {
439                 entry->vccs->xoff = 0;
440                 return NETDEV_TX_OK;
441         }
442         spin_lock_irqsave(&clip_priv->xoff_lock, flags);
443         netif_stop_queue(dev);  /* XOFF -> throttle immediately */
444         barrier();
445         if (!entry->vccs->xoff)
446                 netif_start_queue(dev);
447         /* Oh, we just raced with clip_pop. netif_start_queue should be
448            good enough, because nothing should really be asleep because
449            of the brief netif_stop_queue. If this isn't true or if it
450            changes, use netif_wake_queue instead. */
451         spin_unlock_irqrestore(&clip_priv->xoff_lock, flags);
452         return NETDEV_TX_OK;
453 }
454
455 static int clip_mkip(struct atm_vcc *vcc, int timeout)
456 {
457         struct clip_vcc *clip_vcc;
458
459         if (!vcc->push)
460                 return -EBADFD;
461         clip_vcc = kmalloc(sizeof(struct clip_vcc), GFP_KERNEL);
462         if (!clip_vcc)
463                 return -ENOMEM;
464         pr_debug("%p vcc %p\n", clip_vcc, vcc);
465         clip_vcc->vcc = vcc;
466         vcc->user_back = clip_vcc;
467         set_bit(ATM_VF_IS_CLIP, &vcc->flags);
468         clip_vcc->entry = NULL;
469         clip_vcc->xoff = 0;
470         clip_vcc->encap = 1;
471         clip_vcc->last_use = jiffies;
472         clip_vcc->idle_timeout = timeout * HZ;
473         clip_vcc->old_push = vcc->push;
474         clip_vcc->old_pop = vcc->pop;
475         vcc->push = clip_push;
476         vcc->pop = clip_pop;
477
478         /* re-process everything received between connection setup and MKIP */
479         vcc_process_recv_queue(vcc);
480
481         return 0;
482 }
483
484 static int clip_setentry(struct atm_vcc *vcc, __be32 ip)
485 {
486         struct neighbour *neigh;
487         struct atmarp_entry *entry;
488         int error;
489         struct clip_vcc *clip_vcc;
490         struct rtable *rt;
491
492         if (vcc->push != clip_push) {
493                 pr_warning("non-CLIP VCC\n");
494                 return -EBADF;
495         }
496         clip_vcc = CLIP_VCC(vcc);
497         if (!ip) {
498                 if (!clip_vcc->entry) {
499                         pr_err("hiding hidden ATMARP entry\n");
500                         return 0;
501                 }
502                 pr_debug("remove\n");
503                 unlink_clip_vcc(clip_vcc);
504                 return 0;
505         }
506         rt = ip_route_output(&init_net, ip, 0, 1, 0);
507         if (IS_ERR(rt))
508                 return PTR_ERR(rt);
509         neigh = __neigh_lookup(&clip_tbl, &ip, rt->dst.dev, 1);
510         ip_rt_put(rt);
511         if (!neigh)
512                 return -ENOMEM;
513         entry = NEIGH2ENTRY(neigh);
514         if (entry != clip_vcc->entry) {
515                 if (!clip_vcc->entry)
516                         pr_debug("add\n");
517                 else {
518                         pr_debug("update\n");
519                         unlink_clip_vcc(clip_vcc);
520                 }
521                 link_vcc(clip_vcc, entry);
522         }
523         error = neigh_update(neigh, llc_oui, NUD_PERMANENT,
524                              NEIGH_UPDATE_F_OVERRIDE | NEIGH_UPDATE_F_ADMIN);
525         neigh_release(neigh);
526         return error;
527 }
528
529 static const struct net_device_ops clip_netdev_ops = {
530         .ndo_start_xmit = clip_start_xmit,
531 };
532
533 static void clip_setup(struct net_device *dev)
534 {
535         dev->netdev_ops = &clip_netdev_ops;
536         dev->type = ARPHRD_ATM;
537         dev->neigh_priv_len = sizeof(struct atmarp_entry);
538         dev->hard_header_len = RFC1483LLC_LEN;
539         dev->mtu = RFC1626_MTU;
540         dev->tx_queue_len = 100;        /* "normal" queue (packets) */
541         /* When using a "real" qdisc, the qdisc determines the queue */
542         /* length. tx_queue_len is only used for the default case, */
543         /* without any more elaborate queuing. 100 is a reasonable */
544         /* compromise between decent burst-tolerance and protection */
545         /* against memory hogs. */
546         dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
547 }
548
549 static int clip_create(int number)
550 {
551         struct net_device *dev;
552         struct clip_priv *clip_priv;
553         int error;
554
555         if (number != -1) {
556                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
557                         if (PRIV(dev)->number == number)
558                                 return -EEXIST;
559         } else {
560                 number = 0;
561                 for (dev = clip_devs; dev; dev = PRIV(dev)->next)
562                         if (PRIV(dev)->number >= number)
563                                 number = PRIV(dev)->number + 1;
564         }
565         dev = alloc_netdev(sizeof(struct clip_priv), "", clip_setup);
566         if (!dev)
567                 return -ENOMEM;
568         clip_priv = PRIV(dev);
569         sprintf(dev->name, "atm%d", number);
570         spin_lock_init(&clip_priv->xoff_lock);
571         clip_priv->number = number;
572         error = register_netdev(dev);
573         if (error) {
574                 free_netdev(dev);
575                 return error;
576         }
577         clip_priv->next = clip_devs;
578         clip_devs = dev;
579         pr_debug("registered (net:%s)\n", dev->name);
580         return number;
581 }
582
583 static int clip_device_event(struct notifier_block *this, unsigned long event,
584                              void *arg)
585 {
586         struct net_device *dev = arg;
587
588         if (!net_eq(dev_net(dev), &init_net))
589                 return NOTIFY_DONE;
590
591         if (event == NETDEV_UNREGISTER) {
592                 neigh_ifdown(&clip_tbl, dev);
593                 return NOTIFY_DONE;
594         }
595
596         /* ignore non-CLIP devices */
597         if (dev->type != ARPHRD_ATM || dev->netdev_ops != &clip_netdev_ops)
598                 return NOTIFY_DONE;
599
600         switch (event) {
601         case NETDEV_UP:
602                 pr_debug("NETDEV_UP\n");
603                 to_atmarpd(act_up, PRIV(dev)->number, 0);
604                 break;
605         case NETDEV_GOING_DOWN:
606                 pr_debug("NETDEV_DOWN\n");
607                 to_atmarpd(act_down, PRIV(dev)->number, 0);
608                 break;
609         case NETDEV_CHANGE:
610         case NETDEV_CHANGEMTU:
611                 pr_debug("NETDEV_CHANGE*\n");
612                 to_atmarpd(act_change, PRIV(dev)->number, 0);
613                 break;
614         }
615         return NOTIFY_DONE;
616 }
617
618 static int clip_inet_event(struct notifier_block *this, unsigned long event,
619                            void *ifa)
620 {
621         struct in_device *in_dev;
622
623         in_dev = ((struct in_ifaddr *)ifa)->ifa_dev;
624         /*
625          * Transitions are of the down-change-up type, so it's sufficient to
626          * handle the change on up.
627          */
628         if (event != NETDEV_UP)
629                 return NOTIFY_DONE;
630         return clip_device_event(this, NETDEV_CHANGE, in_dev->dev);
631 }
632
633 static struct notifier_block clip_dev_notifier = {
634         .notifier_call = clip_device_event,
635 };
636
637
638
639 static struct notifier_block clip_inet_notifier = {
640         .notifier_call = clip_inet_event,
641 };
642
643
644
645 static void atmarpd_close(struct atm_vcc *vcc)
646 {
647         pr_debug("\n");
648
649         rtnl_lock();
650         atmarpd = NULL;
651         skb_queue_purge(&sk_atm(vcc)->sk_receive_queue);
652         rtnl_unlock();
653
654         pr_debug("(done)\n");
655         module_put(THIS_MODULE);
656 }
657
658 static struct atmdev_ops atmarpd_dev_ops = {
659         .close = atmarpd_close
660 };
661
662
663 static struct atm_dev atmarpd_dev = {
664         .ops =                  &atmarpd_dev_ops,
665         .type =                 "arpd",
666         .number =               999,
667         .lock =                 __SPIN_LOCK_UNLOCKED(atmarpd_dev.lock)
668 };
669
670
671 static int atm_init_atmarp(struct atm_vcc *vcc)
672 {
673         rtnl_lock();
674         if (atmarpd) {
675                 rtnl_unlock();
676                 return -EADDRINUSE;
677         }
678
679         mod_timer(&idle_timer, jiffies + CLIP_CHECK_INTERVAL * HZ);
680
681         atmarpd = vcc;
682         set_bit(ATM_VF_META, &vcc->flags);
683         set_bit(ATM_VF_READY, &vcc->flags);
684             /* allow replies and avoid getting closed if signaling dies */
685         vcc->dev = &atmarpd_dev;
686         vcc_insert_socket(sk_atm(vcc));
687         vcc->push = NULL;
688         vcc->pop = NULL; /* crash */
689         vcc->push_oam = NULL; /* crash */
690         rtnl_unlock();
691         return 0;
692 }
693
694 static int clip_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
695 {
696         struct atm_vcc *vcc = ATM_SD(sock);
697         int err = 0;
698
699         switch (cmd) {
700         case SIOCMKCLIP:
701         case ATMARPD_CTRL:
702         case ATMARP_MKIP:
703         case ATMARP_SETENTRY:
704         case ATMARP_ENCAP:
705                 if (!capable(CAP_NET_ADMIN))
706                         return -EPERM;
707                 break;
708         default:
709                 return -ENOIOCTLCMD;
710         }
711
712         switch (cmd) {
713         case SIOCMKCLIP:
714                 err = clip_create(arg);
715                 break;
716         case ATMARPD_CTRL:
717                 err = atm_init_atmarp(vcc);
718                 if (!err) {
719                         sock->state = SS_CONNECTED;
720                         __module_get(THIS_MODULE);
721                 }
722                 break;
723         case ATMARP_MKIP:
724                 err = clip_mkip(vcc, arg);
725                 break;
726         case ATMARP_SETENTRY:
727                 err = clip_setentry(vcc, (__force __be32)arg);
728                 break;
729         case ATMARP_ENCAP:
730                 err = clip_encap(vcc, arg);
731                 break;
732         }
733         return err;
734 }
735
736 static struct atm_ioctl clip_ioctl_ops = {
737         .owner = THIS_MODULE,
738         .ioctl = clip_ioctl,
739 };
740
741 #ifdef CONFIG_PROC_FS
742
743 static void svc_addr(struct seq_file *seq, struct sockaddr_atmsvc *addr)
744 {
745         static int code[] = { 1, 2, 10, 6, 1, 0 };
746         static int e164[] = { 1, 8, 4, 6, 1, 0 };
747
748         if (*addr->sas_addr.pub) {
749                 seq_printf(seq, "%s", addr->sas_addr.pub);
750                 if (*addr->sas_addr.prv)
751                         seq_putc(seq, '+');
752         } else if (!*addr->sas_addr.prv) {
753                 seq_printf(seq, "%s", "(none)");
754                 return;
755         }
756         if (*addr->sas_addr.prv) {
757                 unsigned char *prv = addr->sas_addr.prv;
758                 int *fields;
759                 int i, j;
760
761                 fields = *prv == ATM_AFI_E164 ? e164 : code;
762                 for (i = 0; fields[i]; i++) {
763                         for (j = fields[i]; j; j--)
764                                 seq_printf(seq, "%02X", *prv++);
765                         if (fields[i + 1])
766                                 seq_putc(seq, '.');
767                 }
768         }
769 }
770
771 /* This means the neighbour entry has no attached VCC objects. */
772 #define SEQ_NO_VCC_TOKEN        ((void *) 2)
773
774 static void atmarp_info(struct seq_file *seq, struct net_device *dev,
775                         struct atmarp_entry *entry, struct clip_vcc *clip_vcc)
776 {
777         unsigned long exp;
778         char buf[17];
779         int svc, llc, off;
780
781         svc = ((clip_vcc == SEQ_NO_VCC_TOKEN) ||
782                (sk_atm(clip_vcc->vcc)->sk_family == AF_ATMSVC));
783
784         llc = ((clip_vcc == SEQ_NO_VCC_TOKEN) || clip_vcc->encap);
785
786         if (clip_vcc == SEQ_NO_VCC_TOKEN)
787                 exp = entry->neigh->used;
788         else
789                 exp = clip_vcc->last_use;
790
791         exp = (jiffies - exp) / HZ;
792
793         seq_printf(seq, "%-6s%-4s%-4s%5ld ",
794                    dev->name, svc ? "SVC" : "PVC", llc ? "LLC" : "NULL", exp);
795
796         off = scnprintf(buf, sizeof(buf) - 1, "%pI4",
797                         &entry->ip);
798         while (off < 16)
799                 buf[off++] = ' ';
800         buf[off] = '\0';
801         seq_printf(seq, "%s", buf);
802
803         if (clip_vcc == SEQ_NO_VCC_TOKEN) {
804                 if (time_before(jiffies, entry->expires))
805                         seq_printf(seq, "(resolving)\n");
806                 else
807                         seq_printf(seq, "(expired, ref %d)\n",
808                                    atomic_read(&entry->neigh->refcnt));
809         } else if (!svc) {
810                 seq_printf(seq, "%d.%d.%d\n",
811                            clip_vcc->vcc->dev->number,
812                            clip_vcc->vcc->vpi, clip_vcc->vcc->vci);
813         } else {
814                 svc_addr(seq, &clip_vcc->vcc->remote);
815                 seq_putc(seq, '\n');
816         }
817 }
818
819 struct clip_seq_state {
820         /* This member must be first. */
821         struct neigh_seq_state ns;
822
823         /* Local to clip specific iteration. */
824         struct clip_vcc *vcc;
825 };
826
827 static struct clip_vcc *clip_seq_next_vcc(struct atmarp_entry *e,
828                                           struct clip_vcc *curr)
829 {
830         if (!curr) {
831                 curr = e->vccs;
832                 if (!curr)
833                         return SEQ_NO_VCC_TOKEN;
834                 return curr;
835         }
836         if (curr == SEQ_NO_VCC_TOKEN)
837                 return NULL;
838
839         curr = curr->next;
840
841         return curr;
842 }
843
844 static void *clip_seq_vcc_walk(struct clip_seq_state *state,
845                                struct atmarp_entry *e, loff_t * pos)
846 {
847         struct clip_vcc *vcc = state->vcc;
848
849         vcc = clip_seq_next_vcc(e, vcc);
850         if (vcc && pos != NULL) {
851                 while (*pos) {
852                         vcc = clip_seq_next_vcc(e, vcc);
853                         if (!vcc)
854                                 break;
855                         --(*pos);
856                 }
857         }
858         state->vcc = vcc;
859
860         return vcc;
861 }
862
863 static void *clip_seq_sub_iter(struct neigh_seq_state *_state,
864                                struct neighbour *n, loff_t * pos)
865 {
866         struct clip_seq_state *state = (struct clip_seq_state *)_state;
867
868         return clip_seq_vcc_walk(state, NEIGH2ENTRY(n), pos);
869 }
870
871 static void *clip_seq_start(struct seq_file *seq, loff_t * pos)
872 {
873         struct clip_seq_state *state = seq->private;
874         state->ns.neigh_sub_iter = clip_seq_sub_iter;
875         return neigh_seq_start(seq, pos, &clip_tbl, NEIGH_SEQ_NEIGH_ONLY);
876 }
877
878 static int clip_seq_show(struct seq_file *seq, void *v)
879 {
880         static char atm_arp_banner[] =
881             "IPitf TypeEncp Idle IP address      ATM address\n";
882
883         if (v == SEQ_START_TOKEN) {
884                 seq_puts(seq, atm_arp_banner);
885         } else {
886                 struct clip_seq_state *state = seq->private;
887                 struct neighbour *n = v;
888                 struct clip_vcc *vcc = state->vcc;
889
890                 atmarp_info(seq, n->dev, NEIGH2ENTRY(n), vcc);
891         }
892         return 0;
893 }
894
895 static const struct seq_operations arp_seq_ops = {
896         .start  = clip_seq_start,
897         .next   = neigh_seq_next,
898         .stop   = neigh_seq_stop,
899         .show   = clip_seq_show,
900 };
901
902 static int arp_seq_open(struct inode *inode, struct file *file)
903 {
904         return seq_open_net(inode, file, &arp_seq_ops,
905                             sizeof(struct clip_seq_state));
906 }
907
908 static const struct file_operations arp_seq_fops = {
909         .open           = arp_seq_open,
910         .read           = seq_read,
911         .llseek         = seq_lseek,
912         .release        = seq_release_net,
913         .owner          = THIS_MODULE
914 };
915 #endif
916
917 static void atm_clip_exit_noproc(void);
918
919 static int __init atm_clip_init(void)
920 {
921         neigh_table_init_no_netlink(&clip_tbl);
922
923         clip_tbl_hook = &clip_tbl;
924         register_atm_ioctl(&clip_ioctl_ops);
925         register_netdevice_notifier(&clip_dev_notifier);
926         register_inetaddr_notifier(&clip_inet_notifier);
927
928         setup_timer(&idle_timer, idle_timer_check, 0);
929
930 #ifdef CONFIG_PROC_FS
931         {
932                 struct proc_dir_entry *p;
933
934                 p = proc_create("arp", S_IRUGO, atm_proc_root, &arp_seq_fops);
935                 if (!p) {
936                         pr_err("Unable to initialize /proc/net/atm/arp\n");
937                         atm_clip_exit_noproc();
938                         return -ENOMEM;
939                 }
940         }
941 #endif
942
943         return 0;
944 }
945
946 static void atm_clip_exit_noproc(void)
947 {
948         struct net_device *dev, *next;
949
950         unregister_inetaddr_notifier(&clip_inet_notifier);
951         unregister_netdevice_notifier(&clip_dev_notifier);
952
953         deregister_atm_ioctl(&clip_ioctl_ops);
954
955         /* First, stop the idle timer, so it stops banging
956          * on the table.
957          */
958         del_timer_sync(&idle_timer);
959
960         /* Next, purge the table, so that the device
961          * unregister loop below does not hang due to
962          * device references remaining in the table.
963          */
964         neigh_ifdown(&clip_tbl, NULL);
965
966         dev = clip_devs;
967         while (dev) {
968                 next = PRIV(dev)->next;
969                 unregister_netdev(dev);
970                 free_netdev(dev);
971                 dev = next;
972         }
973
974         /* Now it is safe to fully shutdown whole table. */
975         neigh_table_clear(&clip_tbl);
976
977         clip_tbl_hook = NULL;
978 }
979
980 static void __exit atm_clip_exit(void)
981 {
982         remove_proc_entry("arp", atm_proc_root);
983
984         atm_clip_exit_noproc();
985 }
986
987 module_init(atm_clip_init);
988 module_exit(atm_clip_exit);
989 MODULE_AUTHOR("Werner Almesberger");
990 MODULE_DESCRIPTION("Classical/IP over ATM interface");
991 MODULE_LICENSE("GPL");