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