[netdrvr] Remove Linux-specific changelogs from several Becker template drivers
[linux-2.6] / drivers / net / tun.c
1 /*
2  *  TUN - Universal TUN/TAP device driver.
3  *  Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com>
4  *
5  *  This program is free software; you can redistribute it and/or modify
6  *  it under the terms of the GNU General Public License as published by
7  *  the Free Software Foundation; either version 2 of the License, or
8  *  (at your option) any later version.
9  *
10  *  This program is distributed in the hope that it will be useful,
11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13  *  GNU General Public License for more details.
14  *
15  *  $Id: tun.c,v 1.15 2002/03/01 02:44:24 maxk Exp $
16  */
17
18 /*
19  *  Changes:
20  *
21  *  Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14
22  *    Add TUNSETLINK ioctl to set the link encapsulation
23  *
24  *  Mark Smith <markzzzsmith@yahoo.com.au>
25  *   Use random_ether_addr() for tap MAC address.
26  *
27  *  Harald Roelle <harald.roelle@ifi.lmu.de>  2004/04/20
28  *    Fixes in packet dropping, queue length setting and queue wakeup.
29  *    Increased default tx queue length.
30  *    Added ethtool API.
31  *    Minor cleanups
32  *
33  *  Daniel Podlejski <underley@underley.eu.org>
34  *    Modifications for 2.3.99-pre5 kernel.
35  */
36
37 #define DRV_NAME        "tun"
38 #define DRV_VERSION     "1.6"
39 #define DRV_DESCRIPTION "Universal TUN/TAP device driver"
40 #define DRV_COPYRIGHT   "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>"
41
42 #include <linux/module.h>
43 #include <linux/errno.h>
44 #include <linux/kernel.h>
45 #include <linux/major.h>
46 #include <linux/slab.h>
47 #include <linux/poll.h>
48 #include <linux/fcntl.h>
49 #include <linux/init.h>
50 #include <linux/skbuff.h>
51 #include <linux/netdevice.h>
52 #include <linux/etherdevice.h>
53 #include <linux/miscdevice.h>
54 #include <linux/ethtool.h>
55 #include <linux/rtnetlink.h>
56 #include <linux/if.h>
57 #include <linux/if_arp.h>
58 #include <linux/if_ether.h>
59 #include <linux/if_tun.h>
60 #include <linux/crc32.h>
61
62 #include <asm/system.h>
63 #include <asm/uaccess.h>
64
65 #ifdef TUN_DEBUG
66 static int debug;
67 #endif
68
69 /* Network device part of the driver */
70
71 static LIST_HEAD(tun_dev_list);
72 static struct ethtool_ops tun_ethtool_ops;
73
74 /* Net device open. */
75 static int tun_net_open(struct net_device *dev)
76 {
77         netif_start_queue(dev);
78         return 0;
79 }
80
81 /* Net device close. */
82 static int tun_net_close(struct net_device *dev)
83 {
84         netif_stop_queue(dev);
85         return 0;
86 }
87
88 /* Net device start xmit */
89 static int tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
90 {
91         struct tun_struct *tun = netdev_priv(dev);
92
93         DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len);
94
95         /* Drop packet if interface is not attached */
96         if (!tun->attached)
97                 goto drop;
98
99         /* Packet dropping */
100         if (skb_queue_len(&tun->readq) >= dev->tx_queue_len) {
101                 if (!(tun->flags & TUN_ONE_QUEUE)) {
102                         /* Normal queueing mode. */
103                         /* Packet scheduler handles dropping of further packets. */
104                         netif_stop_queue(dev);
105
106                         /* We won't see all dropped packets individually, so overrun
107                          * error is more appropriate. */
108                         tun->stats.tx_fifo_errors++;
109                 } else {
110                         /* Single queue mode.
111                          * Driver handles dropping of all packets itself. */
112                         goto drop;
113                 }
114         }
115
116         /* Queue packet */
117         skb_queue_tail(&tun->readq, skb);
118         dev->trans_start = jiffies;
119
120         /* Notify and wake up reader process */
121         if (tun->flags & TUN_FASYNC)
122                 kill_fasync(&tun->fasync, SIGIO, POLL_IN);
123         wake_up_interruptible(&tun->read_wait);
124         return 0;
125
126 drop:
127         tun->stats.tx_dropped++;
128         kfree_skb(skb);
129         return 0;
130 }
131
132 /** Add the specified Ethernet address to this multicast filter. */
133 static void
134 add_multi(u32* filter, const u8* addr)
135 {
136         int bit_nr = ether_crc(ETH_ALEN, addr) >> 26;
137         filter[bit_nr >> 5] |= 1 << (bit_nr & 31);
138 }
139
140 /** Remove the specified Ethernet addres from this multicast filter. */
141 static void
142 del_multi(u32* filter, const u8* addr)
143 {
144         int bit_nr = ether_crc(ETH_ALEN, addr) >> 26;
145         filter[bit_nr >> 5] &= ~(1 << (bit_nr & 31));
146 }
147
148 /** Update the list of multicast groups to which the network device belongs.
149  * This list is used to filter packets being sent from the character device to
150  * the network device. */
151 static void
152 tun_net_mclist(struct net_device *dev)
153 {
154         struct tun_struct *tun = netdev_priv(dev);
155         const struct dev_mc_list *mclist;
156         int i;
157         DBG(KERN_DEBUG "%s: tun_net_mclist: mc_count %d\n",
158                         dev->name, dev->mc_count);
159         memset(tun->chr_filter, 0, sizeof tun->chr_filter);
160         for (i = 0, mclist = dev->mc_list; i < dev->mc_count && mclist != NULL;
161                         i++, mclist = mclist->next) {
162                 add_multi(tun->net_filter, mclist->dmi_addr);
163                 DBG(KERN_DEBUG "%s: tun_net_mclist: %x:%x:%x:%x:%x:%x\n",
164                                 dev->name,
165                                 mclist->dmi_addr[0], mclist->dmi_addr[1], mclist->dmi_addr[2],
166                                 mclist->dmi_addr[3], mclist->dmi_addr[4], mclist->dmi_addr[5]);
167         }
168 }
169
170 static struct net_device_stats *tun_net_stats(struct net_device *dev)
171 {
172         struct tun_struct *tun = netdev_priv(dev);
173         return &tun->stats;
174 }
175
176 /* Initialize net device. */
177 static void tun_net_init(struct net_device *dev)
178 {
179         struct tun_struct *tun = netdev_priv(dev);
180    
181         switch (tun->flags & TUN_TYPE_MASK) {
182         case TUN_TUN_DEV:
183                 /* Point-to-Point TUN Device */
184                 dev->hard_header_len = 0;
185                 dev->addr_len = 0;
186                 dev->mtu = 1500;
187
188                 /* Zero header length */
189                 dev->type = ARPHRD_NONE; 
190                 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
191                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
192                 break;
193
194         case TUN_TAP_DEV:
195                 /* Ethernet TAP Device */
196                 dev->set_multicast_list = tun_net_mclist;
197
198                 ether_setup(dev);
199                 random_ether_addr(dev->dev_addr);
200                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
201                 break;
202         }
203 }
204
205 /* Character device part */
206
207 /* Poll */
208 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
209 {  
210         struct tun_struct *tun = file->private_data;
211         unsigned int mask = POLLOUT | POLLWRNORM;
212
213         if (!tun)
214                 return -EBADFD;
215
216         DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name);
217
218         poll_wait(file, &tun->read_wait, wait);
219  
220         if (!skb_queue_empty(&tun->readq))
221                 mask |= POLLIN | POLLRDNORM;
222
223         return mask;
224 }
225
226 /* Get packet from user space buffer */
227 static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, size_t count)
228 {
229         struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) };
230         struct sk_buff *skb;
231         size_t len = count, align = 0;
232
233         if (!(tun->flags & TUN_NO_PI)) {
234                 if ((len -= sizeof(pi)) > count)
235                         return -EINVAL;
236
237                 if(memcpy_fromiovec((void *)&pi, iv, sizeof(pi)))
238                         return -EFAULT;
239         }
240
241         if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV)
242                 align = NET_IP_ALIGN;
243  
244         if (!(skb = alloc_skb(len + align, GFP_KERNEL))) {
245                 tun->stats.rx_dropped++;
246                 return -ENOMEM;
247         }
248
249         if (align)
250                 skb_reserve(skb, align);
251         if (memcpy_fromiovec(skb_put(skb, len), iv, len)) {
252                 tun->stats.rx_dropped++;
253                 kfree_skb(skb);
254                 return -EFAULT;
255         }
256
257         skb->dev = tun->dev;
258         switch (tun->flags & TUN_TYPE_MASK) {
259         case TUN_TUN_DEV:
260                 skb->mac.raw = skb->data;
261                 skb->protocol = pi.proto;
262                 break;
263         case TUN_TAP_DEV:
264                 skb->protocol = eth_type_trans(skb, tun->dev);
265                 break;
266         };
267
268         if (tun->flags & TUN_NOCHECKSUM)
269                 skb->ip_summed = CHECKSUM_UNNECESSARY;
270  
271         netif_rx_ni(skb);
272         tun->dev->last_rx = jiffies;
273    
274         tun->stats.rx_packets++;
275         tun->stats.rx_bytes += len;
276
277         return count;
278
279
280 static inline size_t iov_total(const struct iovec *iv, unsigned long count)
281 {
282         unsigned long i;
283         size_t len;
284
285         for (i = 0, len = 0; i < count; i++) 
286                 len += iv[i].iov_len;
287
288         return len;
289 }
290
291 /* Writev */
292 static ssize_t tun_chr_writev(struct file * file, const struct iovec *iv, 
293                               unsigned long count, loff_t *pos)
294 {
295         struct tun_struct *tun = file->private_data;
296
297         if (!tun)
298                 return -EBADFD;
299
300         DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);
301
302         return tun_get_user(tun, (struct iovec *) iv, iov_total(iv, count));
303 }
304
305 /* Write */
306 static ssize_t tun_chr_write(struct file * file, const char __user * buf, 
307                              size_t count, loff_t *pos)
308 {
309         struct iovec iv = { (void __user *) buf, count };
310         return tun_chr_writev(file, &iv, 1, pos);
311 }
312
313 /* Put packet to the user space buffer */
314 static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
315                                        struct sk_buff *skb,
316                                        struct iovec *iv, int len)
317 {
318         struct tun_pi pi = { 0, skb->protocol };
319         ssize_t total = 0;
320
321         if (!(tun->flags & TUN_NO_PI)) {
322                 if ((len -= sizeof(pi)) < 0)
323                         return -EINVAL;
324
325                 if (len < skb->len) {
326                         /* Packet will be striped */
327                         pi.flags |= TUN_PKT_STRIP;
328                 }
329  
330                 if (memcpy_toiovec(iv, (void *) &pi, sizeof(pi)))
331                         return -EFAULT;
332                 total += sizeof(pi);
333         }       
334
335         len = min_t(int, skb->len, len);
336
337         skb_copy_datagram_iovec(skb, 0, iv, len);
338         total += len;
339
340         tun->stats.tx_packets++;
341         tun->stats.tx_bytes += len;
342
343         return total;
344 }
345
346 /* Readv */
347 static ssize_t tun_chr_readv(struct file *file, const struct iovec *iv,
348                             unsigned long count, loff_t *pos)
349 {
350         struct tun_struct *tun = file->private_data;
351         DECLARE_WAITQUEUE(wait, current);
352         struct sk_buff *skb;
353         ssize_t len, ret = 0;
354
355         if (!tun)
356                 return -EBADFD;
357
358         DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
359
360         len = iov_total(iv, count);
361         if (len < 0)
362                 return -EINVAL;
363
364         add_wait_queue(&tun->read_wait, &wait);
365         while (len) {
366                 const u8 ones[ ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
367                 u8 addr[ ETH_ALEN];
368                 int bit_nr;
369
370                 current->state = TASK_INTERRUPTIBLE;
371
372                 /* Read frames from the queue */
373                 if (!(skb=skb_dequeue(&tun->readq))) {
374                         if (file->f_flags & O_NONBLOCK) {
375                                 ret = -EAGAIN;
376                                 break;
377                         }
378                         if (signal_pending(current)) {
379                                 ret = -ERESTARTSYS;
380                                 break;
381                         }
382
383                         /* Nothing to read, let's sleep */
384                         schedule();
385                         continue;
386                 }
387                 netif_wake_queue(tun->dev);
388
389                 /** Decide whether to accept this packet. This code is designed to
390                  * behave identically to an Ethernet interface. Accept the packet if
391                  * - we are promiscuous.
392                  * - the packet is addressed to us.
393                  * - the packet is broadcast.
394                  * - the packet is multicast and
395                  *   - we are multicast promiscous.
396                  *   - we belong to the multicast group.
397                  */
398                 memcpy(addr, skb->data,
399                        min_t(size_t, sizeof addr, skb->len));
400                 bit_nr = ether_crc(sizeof addr, addr) >> 26;
401                 if ((tun->if_flags & IFF_PROMISC) ||
402                                 memcmp(addr, tun->dev_addr, sizeof addr) == 0 ||
403                                 memcmp(addr, ones, sizeof addr) == 0 ||
404                                 (((addr[0] == 1 && addr[1] == 0 && addr[2] == 0x5e) ||
405                                   (addr[0] == 0x33 && addr[1] == 0x33)) &&
406                                  ((tun->if_flags & IFF_ALLMULTI) ||
407                                   (tun->chr_filter[bit_nr >> 5] & (1 << (bit_nr & 31)))))) {
408                         DBG(KERN_DEBUG "%s: tun_chr_readv: accepted: %x:%x:%x:%x:%x:%x\n",
409                                         tun->dev->name, addr[0], addr[1], addr[2],
410                                         addr[3], addr[4], addr[5]);
411                         ret = tun_put_user(tun, skb, (struct iovec *) iv, len);
412                         kfree_skb(skb);
413                         break;
414                 } else {
415                         DBG(KERN_DEBUG "%s: tun_chr_readv: rejected: %x:%x:%x:%x:%x:%x\n",
416                                         tun->dev->name, addr[0], addr[1], addr[2],
417                                         addr[3], addr[4], addr[5]);
418                         kfree_skb(skb);
419                         continue;
420                 }
421         }
422
423         current->state = TASK_RUNNING;
424         remove_wait_queue(&tun->read_wait, &wait);
425
426         return ret;
427 }
428
429 /* Read */
430 static ssize_t tun_chr_read(struct file * file, char __user * buf, 
431                             size_t count, loff_t *pos)
432 {
433         struct iovec iv = { buf, count };
434         return tun_chr_readv(file, &iv, 1, pos);
435 }
436
437 static void tun_setup(struct net_device *dev)
438 {
439         struct tun_struct *tun = netdev_priv(dev);
440
441         skb_queue_head_init(&tun->readq);
442         init_waitqueue_head(&tun->read_wait);
443
444         tun->owner = -1;
445
446         SET_MODULE_OWNER(dev);
447         dev->open = tun_net_open;
448         dev->hard_start_xmit = tun_net_xmit;
449         dev->stop = tun_net_close;
450         dev->get_stats = tun_net_stats;
451         dev->ethtool_ops = &tun_ethtool_ops;
452         dev->destructor = free_netdev;
453 }
454
455 static struct tun_struct *tun_get_by_name(const char *name)
456 {
457         struct tun_struct *tun;
458
459         ASSERT_RTNL();
460         list_for_each_entry(tun, &tun_dev_list, list) {
461                 if (!strncmp(tun->dev->name, name, IFNAMSIZ))
462                     return tun;
463         }
464
465         return NULL;
466 }
467
468 static int tun_set_iff(struct file *file, struct ifreq *ifr)
469 {
470         struct tun_struct *tun;
471         struct net_device *dev;
472         int err;
473
474         tun = tun_get_by_name(ifr->ifr_name);
475         if (tun) {
476                 if (tun->attached)
477                         return -EBUSY;
478
479                 /* Check permissions */
480                 if (tun->owner != -1 &&
481                     current->euid != tun->owner && !capable(CAP_NET_ADMIN))
482                         return -EPERM;
483         } 
484         else if (__dev_get_by_name(ifr->ifr_name)) 
485                 return -EINVAL;
486         else {
487                 char *name;
488                 unsigned long flags = 0;
489
490                 err = -EINVAL;
491
492                 if (!capable(CAP_NET_ADMIN))
493                         return -EPERM;
494
495                 /* Set dev type */
496                 if (ifr->ifr_flags & IFF_TUN) {
497                         /* TUN device */
498                         flags |= TUN_TUN_DEV;
499                         name = "tun%d";
500                 } else if (ifr->ifr_flags & IFF_TAP) {
501                         /* TAP device */
502                         flags |= TUN_TAP_DEV;
503                         name = "tap%d";
504                 } else 
505                         goto failed;
506    
507                 if (*ifr->ifr_name)
508                         name = ifr->ifr_name;
509
510                 dev = alloc_netdev(sizeof(struct tun_struct), name,
511                                    tun_setup);
512                 if (!dev)
513                         return -ENOMEM;
514
515                 tun = netdev_priv(dev);
516                 tun->dev = dev;
517                 tun->flags = flags;
518                 /* Be promiscuous by default to maintain previous behaviour. */
519                 tun->if_flags = IFF_PROMISC;
520                 /* Generate random Ethernet address. */
521                 *(u16 *)tun->dev_addr = htons(0x00FF);
522                 get_random_bytes(tun->dev_addr + sizeof(u16), 4);
523                 memset(tun->chr_filter, 0, sizeof tun->chr_filter);
524
525                 tun_net_init(dev);
526
527                 if (strchr(dev->name, '%')) {
528                         err = dev_alloc_name(dev, dev->name);
529                         if (err < 0)
530                                 goto err_free_dev;
531                 }
532
533                 err = register_netdevice(tun->dev);
534                 if (err < 0)
535                         goto err_free_dev;
536         
537                 list_add(&tun->list, &tun_dev_list);
538         }
539
540         DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);
541
542         if (ifr->ifr_flags & IFF_NO_PI)
543                 tun->flags |= TUN_NO_PI;
544
545         if (ifr->ifr_flags & IFF_ONE_QUEUE)
546                 tun->flags |= TUN_ONE_QUEUE;
547
548         file->private_data = tun;
549         tun->attached = 1;
550
551         strcpy(ifr->ifr_name, tun->dev->name);
552         return 0;
553
554  err_free_dev:
555         free_netdev(dev);
556  failed:
557         return err;
558 }
559
560 static int tun_chr_ioctl(struct inode *inode, struct file *file, 
561                          unsigned int cmd, unsigned long arg)
562 {
563         struct tun_struct *tun = file->private_data;
564         void __user* argp = (void __user*)arg;
565         struct ifreq ifr;
566
567         if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
568                 if (copy_from_user(&ifr, argp, sizeof ifr))
569                         return -EFAULT;
570
571         if (cmd == TUNSETIFF && !tun) {
572                 int err;
573
574                 ifr.ifr_name[IFNAMSIZ-1] = '\0';
575
576                 rtnl_lock();
577                 err = tun_set_iff(file, &ifr);
578                 rtnl_unlock();
579
580                 if (err)
581                         return err;
582
583                 if (copy_to_user(argp, &ifr, sizeof(ifr)))
584                         return -EFAULT;
585                 return 0;
586         }
587
588         if (!tun)
589                 return -EBADFD;
590
591         DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd);
592
593         switch (cmd) {
594         case TUNSETNOCSUM:
595                 /* Disable/Enable checksum */
596                 if (arg)
597                         tun->flags |= TUN_NOCHECKSUM;
598                 else
599                         tun->flags &= ~TUN_NOCHECKSUM;
600
601                 DBG(KERN_INFO "%s: checksum %s\n",
602                     tun->dev->name, arg ? "disabled" : "enabled");
603                 break;
604
605         case TUNSETPERSIST:
606                 /* Disable/Enable persist mode */
607                 if (arg)
608                         tun->flags |= TUN_PERSIST;
609                 else
610                         tun->flags &= ~TUN_PERSIST;
611
612                 DBG(KERN_INFO "%s: persist %s\n",
613                     tun->dev->name, arg ? "disabled" : "enabled");
614                 break;
615
616         case TUNSETOWNER:
617                 /* Set owner of the device */
618                 tun->owner = (uid_t) arg;
619
620                 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner);
621                 break;
622
623         case TUNSETLINK:
624                 /* Only allow setting the type when the interface is down */
625                 if (tun->dev->flags & IFF_UP) {
626                         DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
627                                 tun->dev->name);
628                         return -EBUSY;
629                 } else {
630                         tun->dev->type = (int) arg;
631                         DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
632                 }
633                 break;
634
635 #ifdef TUN_DEBUG
636         case TUNSETDEBUG:
637                 tun->debug = arg;
638                 break;
639 #endif
640
641         case SIOCGIFFLAGS:
642                 ifr.ifr_flags = tun->if_flags;
643                 if (copy_to_user( argp, &ifr, sizeof ifr))
644                         return -EFAULT;
645                 return 0;
646
647         case SIOCSIFFLAGS:
648                 /** Set the character device's interface flags. Currently only
649                  * IFF_PROMISC and IFF_ALLMULTI are used. */
650                 tun->if_flags = ifr.ifr_flags;
651                 DBG(KERN_INFO "%s: interface flags 0x%lx\n",
652                                 tun->dev->name, tun->if_flags);
653                 return 0;
654
655         case SIOCGIFHWADDR:
656                 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev_addr,
657                                 min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr));
658                 if (copy_to_user( argp, &ifr, sizeof ifr))
659                         return -EFAULT;
660                 return 0;
661
662         case SIOCSIFHWADDR:
663                 /** Set the character device's hardware address. This is used when
664                  * filtering packets being sent from the network device to the character
665                  * device. */
666                 memcpy(tun->dev_addr, ifr.ifr_hwaddr.sa_data,
667                                 min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr));
668                 DBG(KERN_DEBUG "%s: set hardware address: %x:%x:%x:%x:%x:%x\n",
669                                 tun->dev->name,
670                                 tun->dev_addr[0], tun->dev_addr[1], tun->dev_addr[2],
671                                 tun->dev_addr[3], tun->dev_addr[4], tun->dev_addr[5]);
672                 return 0;
673
674         case SIOCADDMULTI:
675                 /** Add the specified group to the character device's multicast filter
676                  * list. */
677                 add_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data);
678                 DBG(KERN_DEBUG "%s: add multi: %x:%x:%x:%x:%x:%x\n",
679                                 tun->dev->name,
680                                 (u8)ifr.ifr_hwaddr.sa_data[0], (u8)ifr.ifr_hwaddr.sa_data[1],
681                                 (u8)ifr.ifr_hwaddr.sa_data[2], (u8)ifr.ifr_hwaddr.sa_data[3],
682                                 (u8)ifr.ifr_hwaddr.sa_data[4], (u8)ifr.ifr_hwaddr.sa_data[5]);
683                 return 0;
684
685         case SIOCDELMULTI:
686                 /** Remove the specified group from the character device's multicast
687                  * filter list. */
688                 del_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data);
689                 DBG(KERN_DEBUG "%s: del multi: %x:%x:%x:%x:%x:%x\n",
690                                 tun->dev->name,
691                                 (u8)ifr.ifr_hwaddr.sa_data[0], (u8)ifr.ifr_hwaddr.sa_data[1],
692                                 (u8)ifr.ifr_hwaddr.sa_data[2], (u8)ifr.ifr_hwaddr.sa_data[3],
693                                 (u8)ifr.ifr_hwaddr.sa_data[4], (u8)ifr.ifr_hwaddr.sa_data[5]);
694                 return 0;
695
696         default:
697                 return -EINVAL;
698         };
699
700         return 0;
701 }
702
703 static int tun_chr_fasync(int fd, struct file *file, int on)
704 {
705         struct tun_struct *tun = file->private_data;
706         int ret;
707
708         if (!tun)
709                 return -EBADFD;
710
711         DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);
712
713         if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
714                 return ret; 
715  
716         if (on) {
717                 ret = f_setown(file, current->pid, 0);
718                 if (ret)
719                         return ret;
720                 tun->flags |= TUN_FASYNC;
721         } else 
722                 tun->flags &= ~TUN_FASYNC;
723
724         return 0;
725 }
726
727 static int tun_chr_open(struct inode *inode, struct file * file)
728 {
729         DBG1(KERN_INFO "tunX: tun_chr_open\n");
730         file->private_data = NULL;
731         return 0;
732 }
733
734 static int tun_chr_close(struct inode *inode, struct file *file)
735 {
736         struct tun_struct *tun = file->private_data;
737
738         if (!tun)
739                 return 0;
740
741         DBG(KERN_INFO "%s: tun_chr_close\n", tun->dev->name);
742
743         tun_chr_fasync(-1, file, 0);
744
745         rtnl_lock();
746
747         /* Detach from net device */
748         file->private_data = NULL;
749         tun->attached = 0;
750
751         /* Drop read queue */
752         skb_queue_purge(&tun->readq);
753
754         if (!(tun->flags & TUN_PERSIST)) {
755                 list_del(&tun->list);
756                 unregister_netdevice(tun->dev);
757         }
758
759         rtnl_unlock();
760
761         return 0;
762 }
763
764 static struct file_operations tun_fops = {
765         .owner  = THIS_MODULE,  
766         .llseek = no_llseek,
767         .read   = tun_chr_read,
768         .readv  = tun_chr_readv,
769         .write  = tun_chr_write,
770         .writev = tun_chr_writev,
771         .poll   = tun_chr_poll,
772         .ioctl  = tun_chr_ioctl,
773         .open   = tun_chr_open,
774         .release = tun_chr_close,
775         .fasync = tun_chr_fasync                
776 };
777
778 static struct miscdevice tun_miscdev = {
779         .minor = TUN_MINOR,
780         .name = "tun",
781         .fops = &tun_fops,
782 };
783
784 /* ethtool interface */
785
786 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
787 {
788         cmd->supported          = 0;
789         cmd->advertising        = 0;
790         cmd->speed              = SPEED_10;
791         cmd->duplex             = DUPLEX_FULL;
792         cmd->port               = PORT_TP;
793         cmd->phy_address        = 0;
794         cmd->transceiver        = XCVR_INTERNAL;
795         cmd->autoneg            = AUTONEG_DISABLE;
796         cmd->maxtxpkt           = 0;
797         cmd->maxrxpkt           = 0;
798         return 0;
799 }
800
801 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
802 {
803         struct tun_struct *tun = netdev_priv(dev);
804
805         strcpy(info->driver, DRV_NAME);
806         strcpy(info->version, DRV_VERSION);
807         strcpy(info->fw_version, "N/A");
808
809         switch (tun->flags & TUN_TYPE_MASK) {
810         case TUN_TUN_DEV:
811                 strcpy(info->bus_info, "tun");
812                 break;
813         case TUN_TAP_DEV:
814                 strcpy(info->bus_info, "tap");
815                 break;
816         }
817 }
818
819 static u32 tun_get_msglevel(struct net_device *dev)
820 {
821 #ifdef TUN_DEBUG
822         struct tun_struct *tun = netdev_priv(dev);
823         return tun->debug;
824 #else
825         return -EOPNOTSUPP;
826 #endif
827 }
828
829 static void tun_set_msglevel(struct net_device *dev, u32 value)
830 {
831 #ifdef TUN_DEBUG
832         struct tun_struct *tun = netdev_priv(dev);
833         tun->debug = value;
834 #endif
835 }
836
837 static u32 tun_get_link(struct net_device *dev)
838 {
839         struct tun_struct *tun = netdev_priv(dev);
840         return tun->attached;
841 }
842
843 static u32 tun_get_rx_csum(struct net_device *dev)
844 {
845         struct tun_struct *tun = netdev_priv(dev);
846         return (tun->flags & TUN_NOCHECKSUM) == 0;
847 }
848
849 static int tun_set_rx_csum(struct net_device *dev, u32 data)
850 {
851         struct tun_struct *tun = netdev_priv(dev);
852         if (data)
853                 tun->flags &= ~TUN_NOCHECKSUM;
854         else
855                 tun->flags |= TUN_NOCHECKSUM;
856         return 0;
857 }
858
859 static struct ethtool_ops tun_ethtool_ops = {
860         .get_settings   = tun_get_settings,
861         .get_drvinfo    = tun_get_drvinfo,
862         .get_msglevel   = tun_get_msglevel,
863         .set_msglevel   = tun_set_msglevel,
864         .get_link       = tun_get_link,
865         .get_rx_csum    = tun_get_rx_csum,
866         .set_rx_csum    = tun_set_rx_csum
867 };
868
869 static int __init tun_init(void)
870 {
871         int ret = 0;
872
873         printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
874         printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);
875
876         ret = misc_register(&tun_miscdev);
877         if (ret)
878                 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
879         return ret;
880 }
881
882 static void tun_cleanup(void)
883 {
884         struct tun_struct *tun, *nxt;
885
886         misc_deregister(&tun_miscdev);  
887
888         rtnl_lock();
889         list_for_each_entry_safe(tun, nxt, &tun_dev_list, list) {
890                 DBG(KERN_INFO "%s cleaned up\n", tun->dev->name);
891                 unregister_netdevice(tun->dev);
892         }
893         rtnl_unlock();
894         
895 }
896
897 module_init(tun_init);
898 module_exit(tun_cleanup);
899 MODULE_DESCRIPTION(DRV_DESCRIPTION);
900 MODULE_AUTHOR(DRV_COPYRIGHT);
901 MODULE_LICENSE("GPL");
902 MODULE_ALIAS_MISCDEV(TUN_MINOR);