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