net: make struct tun_struct private to tun.c
[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  *  Brian Braunstein <linuxkernel@bristyle.com> 2007/03/23
22  *    Fixed hw address handling.  Now net_device.dev_addr is kept consistent
23  *    with tun.dev_addr when the address is set by this module.
24  *
25  *  Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14
26  *    Add TUNSETLINK ioctl to set the link encapsulation
27  *
28  *  Mark Smith <markzzzsmith@yahoo.com.au>
29  *   Use random_ether_addr() for tap MAC address.
30  *
31  *  Harald Roelle <harald.roelle@ifi.lmu.de>  2004/04/20
32  *    Fixes in packet dropping, queue length setting and queue wakeup.
33  *    Increased default tx queue length.
34  *    Added ethtool API.
35  *    Minor cleanups
36  *
37  *  Daniel Podlejski <underley@underley.eu.org>
38  *    Modifications for 2.3.99-pre5 kernel.
39  */
40
41 #define DRV_NAME        "tun"
42 #define DRV_VERSION     "1.6"
43 #define DRV_DESCRIPTION "Universal TUN/TAP device driver"
44 #define DRV_COPYRIGHT   "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>"
45
46 #include <linux/module.h>
47 #include <linux/errno.h>
48 #include <linux/kernel.h>
49 #include <linux/major.h>
50 #include <linux/slab.h>
51 #include <linux/poll.h>
52 #include <linux/fcntl.h>
53 #include <linux/init.h>
54 #include <linux/skbuff.h>
55 #include <linux/netdevice.h>
56 #include <linux/etherdevice.h>
57 #include <linux/miscdevice.h>
58 #include <linux/ethtool.h>
59 #include <linux/rtnetlink.h>
60 #include <linux/if.h>
61 #include <linux/if_arp.h>
62 #include <linux/if_ether.h>
63 #include <linux/if_tun.h>
64 #include <linux/crc32.h>
65 #include <net/net_namespace.h>
66
67 #include <asm/system.h>
68 #include <asm/uaccess.h>
69
70 /* Uncomment to enable debugging */
71 /* #define TUN_DEBUG 1 */
72
73 #ifdef TUN_DEBUG
74 static int debug;
75
76 #define DBG  if(tun->debug)printk
77 #define DBG1 if(debug==2)printk
78 #else
79 #define DBG( a... )
80 #define DBG1( a... )
81 #endif
82
83 struct tun_struct {
84         struct list_head        list;
85         unsigned long           flags;
86         int                     attached;
87         uid_t                   owner;
88         gid_t                   group;
89
90         wait_queue_head_t       read_wait;
91         struct sk_buff_head     readq;
92
93         struct net_device       *dev;
94
95         struct fasync_struct    *fasync;
96
97         unsigned long if_flags;
98         u8 dev_addr[ETH_ALEN];
99         u32 chr_filter[2];
100         u32 net_filter[2];
101
102 #ifdef TUN_DEBUG
103         int debug;
104 #endif
105 };
106
107 /* Network device part of the driver */
108
109 static LIST_HEAD(tun_dev_list);
110 static const struct ethtool_ops tun_ethtool_ops;
111
112 /* Net device open. */
113 static int tun_net_open(struct net_device *dev)
114 {
115         netif_start_queue(dev);
116         return 0;
117 }
118
119 /* Net device close. */
120 static int tun_net_close(struct net_device *dev)
121 {
122         netif_stop_queue(dev);
123         return 0;
124 }
125
126 /* Net device start xmit */
127 static int tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
128 {
129         struct tun_struct *tun = netdev_priv(dev);
130
131         DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len);
132
133         /* Drop packet if interface is not attached */
134         if (!tun->attached)
135                 goto drop;
136
137         /* Packet dropping */
138         if (skb_queue_len(&tun->readq) >= dev->tx_queue_len) {
139                 if (!(tun->flags & TUN_ONE_QUEUE)) {
140                         /* Normal queueing mode. */
141                         /* Packet scheduler handles dropping of further packets. */
142                         netif_stop_queue(dev);
143
144                         /* We won't see all dropped packets individually, so overrun
145                          * error is more appropriate. */
146                         dev->stats.tx_fifo_errors++;
147                 } else {
148                         /* Single queue mode.
149                          * Driver handles dropping of all packets itself. */
150                         goto drop;
151                 }
152         }
153
154         /* Queue packet */
155         skb_queue_tail(&tun->readq, skb);
156         dev->trans_start = jiffies;
157
158         /* Notify and wake up reader process */
159         if (tun->flags & TUN_FASYNC)
160                 kill_fasync(&tun->fasync, SIGIO, POLL_IN);
161         wake_up_interruptible(&tun->read_wait);
162         return 0;
163
164 drop:
165         dev->stats.tx_dropped++;
166         kfree_skb(skb);
167         return 0;
168 }
169
170 /** Add the specified Ethernet address to this multicast filter. */
171 static void
172 add_multi(u32* filter, const u8* addr)
173 {
174         int bit_nr = ether_crc(ETH_ALEN, addr) >> 26;
175         filter[bit_nr >> 5] |= 1 << (bit_nr & 31);
176 }
177
178 /** Remove the specified Ethernet addres from this multicast filter. */
179 static void
180 del_multi(u32* filter, const u8* addr)
181 {
182         int bit_nr = ether_crc(ETH_ALEN, addr) >> 26;
183         filter[bit_nr >> 5] &= ~(1 << (bit_nr & 31));
184 }
185
186 /** Update the list of multicast groups to which the network device belongs.
187  * This list is used to filter packets being sent from the character device to
188  * the network device. */
189 static void
190 tun_net_mclist(struct net_device *dev)
191 {
192         struct tun_struct *tun = netdev_priv(dev);
193         const struct dev_mc_list *mclist;
194         int i;
195         DECLARE_MAC_BUF(mac);
196         DBG(KERN_DEBUG "%s: tun_net_mclist: mc_count %d\n",
197                         dev->name, dev->mc_count);
198         memset(tun->chr_filter, 0, sizeof tun->chr_filter);
199         for (i = 0, mclist = dev->mc_list; i < dev->mc_count && mclist != NULL;
200                         i++, mclist = mclist->next) {
201                 add_multi(tun->net_filter, mclist->dmi_addr);
202                 DBG(KERN_DEBUG "%s: tun_net_mclist: %s\n",
203                     dev->name, print_mac(mac, mclist->dmi_addr));
204         }
205 }
206
207 #define MIN_MTU 68
208 #define MAX_MTU 65535
209
210 static int
211 tun_net_change_mtu(struct net_device *dev, int new_mtu)
212 {
213         if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
214                 return -EINVAL;
215         dev->mtu = new_mtu;
216         return 0;
217 }
218
219 /* Initialize net device. */
220 static void tun_net_init(struct net_device *dev)
221 {
222         struct tun_struct *tun = netdev_priv(dev);
223
224         switch (tun->flags & TUN_TYPE_MASK) {
225         case TUN_TUN_DEV:
226                 /* Point-to-Point TUN Device */
227                 dev->hard_header_len = 0;
228                 dev->addr_len = 0;
229                 dev->mtu = 1500;
230                 dev->change_mtu = tun_net_change_mtu;
231
232                 /* Zero header length */
233                 dev->type = ARPHRD_NONE;
234                 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
235                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
236                 break;
237
238         case TUN_TAP_DEV:
239                 /* Ethernet TAP Device */
240                 dev->set_multicast_list = tun_net_mclist;
241
242                 ether_setup(dev);
243                 dev->change_mtu = tun_net_change_mtu;
244
245                 /* random address already created for us by tun_set_iff, use it */
246                 memcpy(dev->dev_addr, tun->dev_addr, min(sizeof(tun->dev_addr), sizeof(dev->dev_addr)) );
247
248                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
249                 break;
250         }
251 }
252
253 /* Character device part */
254
255 /* Poll */
256 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
257 {
258         struct tun_struct *tun = file->private_data;
259         unsigned int mask = POLLOUT | POLLWRNORM;
260
261         if (!tun)
262                 return -EBADFD;
263
264         DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name);
265
266         poll_wait(file, &tun->read_wait, wait);
267
268         if (!skb_queue_empty(&tun->readq))
269                 mask |= POLLIN | POLLRDNORM;
270
271         return mask;
272 }
273
274 /* Get packet from user space buffer */
275 static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, size_t count)
276 {
277         struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) };
278         struct sk_buff *skb;
279         size_t len = count, align = 0;
280
281         if (!(tun->flags & TUN_NO_PI)) {
282                 if ((len -= sizeof(pi)) > count)
283                         return -EINVAL;
284
285                 if(memcpy_fromiovec((void *)&pi, iv, sizeof(pi)))
286                         return -EFAULT;
287         }
288
289         if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV)
290                 align = NET_IP_ALIGN;
291
292         if (!(skb = alloc_skb(len + align, GFP_KERNEL))) {
293                 tun->dev->stats.rx_dropped++;
294                 return -ENOMEM;
295         }
296
297         if (align)
298                 skb_reserve(skb, align);
299         if (memcpy_fromiovec(skb_put(skb, len), iv, len)) {
300                 tun->dev->stats.rx_dropped++;
301                 kfree_skb(skb);
302                 return -EFAULT;
303         }
304
305         switch (tun->flags & TUN_TYPE_MASK) {
306         case TUN_TUN_DEV:
307                 skb_reset_mac_header(skb);
308                 skb->protocol = pi.proto;
309                 skb->dev = tun->dev;
310                 break;
311         case TUN_TAP_DEV:
312                 skb->protocol = eth_type_trans(skb, tun->dev);
313                 break;
314         };
315
316         if (tun->flags & TUN_NOCHECKSUM)
317                 skb->ip_summed = CHECKSUM_UNNECESSARY;
318
319         netif_rx_ni(skb);
320         tun->dev->last_rx = jiffies;
321
322         tun->dev->stats.rx_packets++;
323         tun->dev->stats.rx_bytes += len;
324
325         return count;
326 }
327
328 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
329                               unsigned long count, loff_t pos)
330 {
331         struct tun_struct *tun = iocb->ki_filp->private_data;
332
333         if (!tun)
334                 return -EBADFD;
335
336         DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);
337
338         return tun_get_user(tun, (struct iovec *) iv, iov_length(iv, count));
339 }
340
341 /* Put packet to the user space buffer */
342 static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
343                                        struct sk_buff *skb,
344                                        struct iovec *iv, int len)
345 {
346         struct tun_pi pi = { 0, skb->protocol };
347         ssize_t total = 0;
348
349         if (!(tun->flags & TUN_NO_PI)) {
350                 if ((len -= sizeof(pi)) < 0)
351                         return -EINVAL;
352
353                 if (len < skb->len) {
354                         /* Packet will be striped */
355                         pi.flags |= TUN_PKT_STRIP;
356                 }
357
358                 if (memcpy_toiovec(iv, (void *) &pi, sizeof(pi)))
359                         return -EFAULT;
360                 total += sizeof(pi);
361         }
362
363         len = min_t(int, skb->len, len);
364
365         skb_copy_datagram_iovec(skb, 0, iv, len);
366         total += len;
367
368         tun->dev->stats.tx_packets++;
369         tun->dev->stats.tx_bytes += len;
370
371         return total;
372 }
373
374 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
375                             unsigned long count, loff_t pos)
376 {
377         struct file *file = iocb->ki_filp;
378         struct tun_struct *tun = file->private_data;
379         DECLARE_WAITQUEUE(wait, current);
380         struct sk_buff *skb;
381         ssize_t len, ret = 0;
382         DECLARE_MAC_BUF(mac);
383
384         if (!tun)
385                 return -EBADFD;
386
387         DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
388
389         len = iov_length(iv, count);
390         if (len < 0)
391                 return -EINVAL;
392
393         add_wait_queue(&tun->read_wait, &wait);
394         while (len) {
395                 const u8 ones[ ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
396                 u8 addr[ ETH_ALEN];
397                 int bit_nr;
398
399                 current->state = TASK_INTERRUPTIBLE;
400
401                 /* Read frames from the queue */
402                 if (!(skb=skb_dequeue(&tun->readq))) {
403                         if (file->f_flags & O_NONBLOCK) {
404                                 ret = -EAGAIN;
405                                 break;
406                         }
407                         if (signal_pending(current)) {
408                                 ret = -ERESTARTSYS;
409                                 break;
410                         }
411
412                         /* Nothing to read, let's sleep */
413                         schedule();
414                         continue;
415                 }
416                 netif_wake_queue(tun->dev);
417
418                 /** Decide whether to accept this packet. This code is designed to
419                  * behave identically to an Ethernet interface. Accept the packet if
420                  * - we are promiscuous.
421                  * - the packet is addressed to us.
422                  * - the packet is broadcast.
423                  * - the packet is multicast and
424                  *   - we are multicast promiscous.
425                  *   - we belong to the multicast group.
426                  */
427                 skb_copy_from_linear_data(skb, addr, min_t(size_t, sizeof addr,
428                                                                    skb->len));
429                 bit_nr = ether_crc(sizeof addr, addr) >> 26;
430                 if ((tun->if_flags & IFF_PROMISC) ||
431                                 memcmp(addr, tun->dev_addr, sizeof addr) == 0 ||
432                                 memcmp(addr, ones, sizeof addr) == 0 ||
433                                 (((addr[0] == 1 && addr[1] == 0 && addr[2] == 0x5e) ||
434                                   (addr[0] == 0x33 && addr[1] == 0x33)) &&
435                                  ((tun->if_flags & IFF_ALLMULTI) ||
436                                   (tun->chr_filter[bit_nr >> 5] & (1 << (bit_nr & 31)))))) {
437                         DBG(KERN_DEBUG "%s: tun_chr_readv: accepted: %s\n",
438                                         tun->dev->name, print_mac(mac, addr));
439                         ret = tun_put_user(tun, skb, (struct iovec *) iv, len);
440                         kfree_skb(skb);
441                         break;
442                 } else {
443                         DBG(KERN_DEBUG "%s: tun_chr_readv: rejected: %s\n",
444                                         tun->dev->name, print_mac(mac, addr));
445                         kfree_skb(skb);
446                         continue;
447                 }
448         }
449
450         current->state = TASK_RUNNING;
451         remove_wait_queue(&tun->read_wait, &wait);
452
453         return ret;
454 }
455
456 static void tun_setup(struct net_device *dev)
457 {
458         struct tun_struct *tun = netdev_priv(dev);
459
460         skb_queue_head_init(&tun->readq);
461         init_waitqueue_head(&tun->read_wait);
462
463         tun->owner = -1;
464         tun->group = -1;
465
466         dev->open = tun_net_open;
467         dev->hard_start_xmit = tun_net_xmit;
468         dev->stop = tun_net_close;
469         dev->ethtool_ops = &tun_ethtool_ops;
470         dev->destructor = free_netdev;
471 }
472
473 static struct tun_struct *tun_get_by_name(const char *name)
474 {
475         struct tun_struct *tun;
476
477         ASSERT_RTNL();
478         list_for_each_entry(tun, &tun_dev_list, list) {
479                 if (!strncmp(tun->dev->name, name, IFNAMSIZ))
480                     return tun;
481         }
482
483         return NULL;
484 }
485
486 static int tun_set_iff(struct file *file, struct ifreq *ifr)
487 {
488         struct tun_struct *tun;
489         struct net_device *dev;
490         int err;
491
492         tun = tun_get_by_name(ifr->ifr_name);
493         if (tun) {
494                 if (tun->attached)
495                         return -EBUSY;
496
497                 /* Check permissions */
498                 if (((tun->owner != -1 &&
499                       current->euid != tun->owner) ||
500                      (tun->group != -1 &&
501                       current->egid != tun->group)) &&
502                      !capable(CAP_NET_ADMIN))
503                         return -EPERM;
504         }
505         else if (__dev_get_by_name(&init_net, ifr->ifr_name))
506                 return -EINVAL;
507         else {
508                 char *name;
509                 unsigned long flags = 0;
510
511                 err = -EINVAL;
512
513                 if (!capable(CAP_NET_ADMIN))
514                         return -EPERM;
515
516                 /* Set dev type */
517                 if (ifr->ifr_flags & IFF_TUN) {
518                         /* TUN device */
519                         flags |= TUN_TUN_DEV;
520                         name = "tun%d";
521                 } else if (ifr->ifr_flags & IFF_TAP) {
522                         /* TAP device */
523                         flags |= TUN_TAP_DEV;
524                         name = "tap%d";
525                 } else
526                         goto failed;
527
528                 if (*ifr->ifr_name)
529                         name = ifr->ifr_name;
530
531                 dev = alloc_netdev(sizeof(struct tun_struct), name,
532                                    tun_setup);
533                 if (!dev)
534                         return -ENOMEM;
535
536                 tun = netdev_priv(dev);
537                 tun->dev = dev;
538                 tun->flags = flags;
539                 /* Be promiscuous by default to maintain previous behaviour. */
540                 tun->if_flags = IFF_PROMISC;
541                 /* Generate random Ethernet address. */
542                 *(__be16 *)tun->dev_addr = htons(0x00FF);
543                 get_random_bytes(tun->dev_addr + sizeof(u16), 4);
544                 memset(tun->chr_filter, 0, sizeof tun->chr_filter);
545
546                 tun_net_init(dev);
547
548                 if (strchr(dev->name, '%')) {
549                         err = dev_alloc_name(dev, dev->name);
550                         if (err < 0)
551                                 goto err_free_dev;
552                 }
553
554                 err = register_netdevice(tun->dev);
555                 if (err < 0)
556                         goto err_free_dev;
557
558                 list_add(&tun->list, &tun_dev_list);
559         }
560
561         DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);
562
563         if (ifr->ifr_flags & IFF_NO_PI)
564                 tun->flags |= TUN_NO_PI;
565         else
566                 tun->flags &= ~TUN_NO_PI;
567
568         if (ifr->ifr_flags & IFF_ONE_QUEUE)
569                 tun->flags |= TUN_ONE_QUEUE;
570         else
571                 tun->flags &= ~TUN_ONE_QUEUE;
572
573         file->private_data = tun;
574         tun->attached = 1;
575
576         strcpy(ifr->ifr_name, tun->dev->name);
577         return 0;
578
579  err_free_dev:
580         free_netdev(dev);
581  failed:
582         return err;
583 }
584
585 static int tun_chr_ioctl(struct inode *inode, struct file *file,
586                          unsigned int cmd, unsigned long arg)
587 {
588         struct tun_struct *tun = file->private_data;
589         void __user* argp = (void __user*)arg;
590         struct ifreq ifr;
591         DECLARE_MAC_BUF(mac);
592
593         if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
594                 if (copy_from_user(&ifr, argp, sizeof ifr))
595                         return -EFAULT;
596
597         if (cmd == TUNSETIFF && !tun) {
598                 int err;
599
600                 ifr.ifr_name[IFNAMSIZ-1] = '\0';
601
602                 rtnl_lock();
603                 err = tun_set_iff(file, &ifr);
604                 rtnl_unlock();
605
606                 if (err)
607                         return err;
608
609                 if (copy_to_user(argp, &ifr, sizeof(ifr)))
610                         return -EFAULT;
611                 return 0;
612         }
613
614         if (!tun)
615                 return -EBADFD;
616
617         DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd);
618
619         switch (cmd) {
620         case TUNSETNOCSUM:
621                 /* Disable/Enable checksum */
622                 if (arg)
623                         tun->flags |= TUN_NOCHECKSUM;
624                 else
625                         tun->flags &= ~TUN_NOCHECKSUM;
626
627                 DBG(KERN_INFO "%s: checksum %s\n",
628                     tun->dev->name, arg ? "disabled" : "enabled");
629                 break;
630
631         case TUNSETPERSIST:
632                 /* Disable/Enable persist mode */
633                 if (arg)
634                         tun->flags |= TUN_PERSIST;
635                 else
636                         tun->flags &= ~TUN_PERSIST;
637
638                 DBG(KERN_INFO "%s: persist %s\n",
639                     tun->dev->name, arg ? "enabled" : "disabled");
640                 break;
641
642         case TUNSETOWNER:
643                 /* Set owner of the device */
644                 tun->owner = (uid_t) arg;
645
646                 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner);
647                 break;
648
649         case TUNSETGROUP:
650                 /* Set group of the device */
651                 tun->group= (gid_t) arg;
652
653                 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group);
654                 break;
655
656         case TUNSETLINK:
657                 /* Only allow setting the type when the interface is down */
658                 if (tun->dev->flags & IFF_UP) {
659                         DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
660                                 tun->dev->name);
661                         return -EBUSY;
662                 } else {
663                         tun->dev->type = (int) arg;
664                         DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
665                 }
666                 break;
667
668 #ifdef TUN_DEBUG
669         case TUNSETDEBUG:
670                 tun->debug = arg;
671                 break;
672 #endif
673
674         case SIOCGIFFLAGS:
675                 ifr.ifr_flags = tun->if_flags;
676                 if (copy_to_user( argp, &ifr, sizeof ifr))
677                         return -EFAULT;
678                 return 0;
679
680         case SIOCSIFFLAGS:
681                 /** Set the character device's interface flags. Currently only
682                  * IFF_PROMISC and IFF_ALLMULTI are used. */
683                 tun->if_flags = ifr.ifr_flags;
684                 DBG(KERN_INFO "%s: interface flags 0x%lx\n",
685                                 tun->dev->name, tun->if_flags);
686                 return 0;
687
688         case SIOCGIFHWADDR:
689                 /* Note: the actual net device's address may be different */
690                 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev_addr,
691                                 min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr));
692                 if (copy_to_user( argp, &ifr, sizeof ifr))
693                         return -EFAULT;
694                 return 0;
695
696         case SIOCSIFHWADDR:
697         {
698                 /* try to set the actual net device's hw address */
699                 int ret;
700
701                 rtnl_lock();
702                 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
703                 rtnl_unlock();
704
705                 if (ret == 0) {
706                         /** Set the character device's hardware address. This is used when
707                          * filtering packets being sent from the network device to the character
708                          * device. */
709                         memcpy(tun->dev_addr, ifr.ifr_hwaddr.sa_data,
710                                         min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr));
711                         DBG(KERN_DEBUG "%s: set hardware address: %x:%x:%x:%x:%x:%x\n",
712                                         tun->dev->name,
713                                         tun->dev_addr[0], tun->dev_addr[1], tun->dev_addr[2],
714                                         tun->dev_addr[3], tun->dev_addr[4], tun->dev_addr[5]);
715                 }
716
717                 return  ret;
718         }
719
720         case SIOCADDMULTI:
721                 /** Add the specified group to the character device's multicast filter
722                  * list. */
723                 add_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data);
724                 DBG(KERN_DEBUG "%s: add multi: %s\n",
725                     tun->dev->name, print_mac(mac, ifr.ifr_hwaddr.sa_data));
726                 return 0;
727
728         case SIOCDELMULTI:
729                 /** Remove the specified group from the character device's multicast
730                  * filter list. */
731                 del_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data);
732                 DBG(KERN_DEBUG "%s: del multi: %s\n",
733                     tun->dev->name, print_mac(mac, ifr.ifr_hwaddr.sa_data));
734                 return 0;
735
736         default:
737                 return -EINVAL;
738         };
739
740         return 0;
741 }
742
743 static int tun_chr_fasync(int fd, struct file *file, int on)
744 {
745         struct tun_struct *tun = file->private_data;
746         int ret;
747
748         if (!tun)
749                 return -EBADFD;
750
751         DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);
752
753         if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
754                 return ret;
755
756         if (on) {
757                 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
758                 if (ret)
759                         return ret;
760                 tun->flags |= TUN_FASYNC;
761         } else
762                 tun->flags &= ~TUN_FASYNC;
763
764         return 0;
765 }
766
767 static int tun_chr_open(struct inode *inode, struct file * file)
768 {
769         DBG1(KERN_INFO "tunX: tun_chr_open\n");
770         file->private_data = NULL;
771         return 0;
772 }
773
774 static int tun_chr_close(struct inode *inode, struct file *file)
775 {
776         struct tun_struct *tun = file->private_data;
777
778         if (!tun)
779                 return 0;
780
781         DBG(KERN_INFO "%s: tun_chr_close\n", tun->dev->name);
782
783         tun_chr_fasync(-1, file, 0);
784
785         rtnl_lock();
786
787         /* Detach from net device */
788         file->private_data = NULL;
789         tun->attached = 0;
790
791         /* Drop read queue */
792         skb_queue_purge(&tun->readq);
793
794         if (!(tun->flags & TUN_PERSIST)) {
795                 list_del(&tun->list);
796                 unregister_netdevice(tun->dev);
797         }
798
799         rtnl_unlock();
800
801         return 0;
802 }
803
804 static const struct file_operations tun_fops = {
805         .owner  = THIS_MODULE,
806         .llseek = no_llseek,
807         .read  = do_sync_read,
808         .aio_read  = tun_chr_aio_read,
809         .write = do_sync_write,
810         .aio_write = tun_chr_aio_write,
811         .poll   = tun_chr_poll,
812         .ioctl  = tun_chr_ioctl,
813         .open   = tun_chr_open,
814         .release = tun_chr_close,
815         .fasync = tun_chr_fasync
816 };
817
818 static struct miscdevice tun_miscdev = {
819         .minor = TUN_MINOR,
820         .name = "tun",
821         .fops = &tun_fops,
822 };
823
824 /* ethtool interface */
825
826 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
827 {
828         cmd->supported          = 0;
829         cmd->advertising        = 0;
830         cmd->speed              = SPEED_10;
831         cmd->duplex             = DUPLEX_FULL;
832         cmd->port               = PORT_TP;
833         cmd->phy_address        = 0;
834         cmd->transceiver        = XCVR_INTERNAL;
835         cmd->autoneg            = AUTONEG_DISABLE;
836         cmd->maxtxpkt           = 0;
837         cmd->maxrxpkt           = 0;
838         return 0;
839 }
840
841 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
842 {
843         struct tun_struct *tun = netdev_priv(dev);
844
845         strcpy(info->driver, DRV_NAME);
846         strcpy(info->version, DRV_VERSION);
847         strcpy(info->fw_version, "N/A");
848
849         switch (tun->flags & TUN_TYPE_MASK) {
850         case TUN_TUN_DEV:
851                 strcpy(info->bus_info, "tun");
852                 break;
853         case TUN_TAP_DEV:
854                 strcpy(info->bus_info, "tap");
855                 break;
856         }
857 }
858
859 static u32 tun_get_msglevel(struct net_device *dev)
860 {
861 #ifdef TUN_DEBUG
862         struct tun_struct *tun = netdev_priv(dev);
863         return tun->debug;
864 #else
865         return -EOPNOTSUPP;
866 #endif
867 }
868
869 static void tun_set_msglevel(struct net_device *dev, u32 value)
870 {
871 #ifdef TUN_DEBUG
872         struct tun_struct *tun = netdev_priv(dev);
873         tun->debug = value;
874 #endif
875 }
876
877 static u32 tun_get_link(struct net_device *dev)
878 {
879         struct tun_struct *tun = netdev_priv(dev);
880         return tun->attached;
881 }
882
883 static u32 tun_get_rx_csum(struct net_device *dev)
884 {
885         struct tun_struct *tun = netdev_priv(dev);
886         return (tun->flags & TUN_NOCHECKSUM) == 0;
887 }
888
889 static int tun_set_rx_csum(struct net_device *dev, u32 data)
890 {
891         struct tun_struct *tun = netdev_priv(dev);
892         if (data)
893                 tun->flags &= ~TUN_NOCHECKSUM;
894         else
895                 tun->flags |= TUN_NOCHECKSUM;
896         return 0;
897 }
898
899 static const struct ethtool_ops tun_ethtool_ops = {
900         .get_settings   = tun_get_settings,
901         .get_drvinfo    = tun_get_drvinfo,
902         .get_msglevel   = tun_get_msglevel,
903         .set_msglevel   = tun_set_msglevel,
904         .get_link       = tun_get_link,
905         .get_rx_csum    = tun_get_rx_csum,
906         .set_rx_csum    = tun_set_rx_csum
907 };
908
909 static int __init tun_init(void)
910 {
911         int ret = 0;
912
913         printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
914         printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);
915
916         ret = misc_register(&tun_miscdev);
917         if (ret)
918                 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
919         return ret;
920 }
921
922 static void tun_cleanup(void)
923 {
924         struct tun_struct *tun, *nxt;
925
926         misc_deregister(&tun_miscdev);
927
928         rtnl_lock();
929         list_for_each_entry_safe(tun, nxt, &tun_dev_list, list) {
930                 DBG(KERN_INFO "%s cleaned up\n", tun->dev->name);
931                 unregister_netdevice(tun->dev);
932         }
933         rtnl_unlock();
934
935 }
936
937 module_init(tun_init);
938 module_exit(tun_cleanup);
939 MODULE_DESCRIPTION(DRV_DESCRIPTION);
940 MODULE_AUTHOR(DRV_COPYRIGHT);
941 MODULE_LICENSE("GPL");
942 MODULE_ALIAS_MISCDEV(TUN_MINOR);