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