Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-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  *  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/smp_lock.h>
52 #include <linux/poll.h>
53 #include <linux/fcntl.h>
54 #include <linux/init.h>
55 #include <linux/skbuff.h>
56 #include <linux/netdevice.h>
57 #include <linux/etherdevice.h>
58 #include <linux/miscdevice.h>
59 #include <linux/ethtool.h>
60 #include <linux/rtnetlink.h>
61 #include <linux/if.h>
62 #include <linux/if_arp.h>
63 #include <linux/if_ether.h>
64 #include <linux/if_tun.h>
65 #include <linux/crc32.h>
66 #include <linux/nsproxy.h>
67 #include <net/net_namespace.h>
68 #include <net/netns/generic.h>
69
70 #include <asm/system.h>
71 #include <asm/uaccess.h>
72
73 /* Uncomment to enable debugging */
74 /* #define TUN_DEBUG 1 */
75
76 #ifdef TUN_DEBUG
77 static int debug;
78
79 #define DBG  if(tun->debug)printk
80 #define DBG1 if(debug==2)printk
81 #else
82 #define DBG( a... )
83 #define DBG1( a... )
84 #endif
85
86 struct tun_struct {
87         struct list_head        list;
88         unsigned long           flags;
89         int                     attached;
90         uid_t                   owner;
91         gid_t                   group;
92
93         wait_queue_head_t       read_wait;
94         struct sk_buff_head     readq;
95
96         struct net_device       *dev;
97
98         struct fasync_struct    *fasync;
99
100         unsigned long if_flags;
101         u8 dev_addr[ETH_ALEN];
102         u32 chr_filter[2];
103         u32 net_filter[2];
104
105 #ifdef TUN_DEBUG
106         int debug;
107 #endif
108 };
109
110 /* Network device part of the driver */
111
112 static unsigned int tun_net_id;
113 struct tun_net {
114         struct list_head dev_list;
115 };
116
117 static const struct ethtool_ops tun_ethtool_ops;
118
119 /* Net device open. */
120 static int tun_net_open(struct net_device *dev)
121 {
122         netif_start_queue(dev);
123         return 0;
124 }
125
126 /* Net device close. */
127 static int tun_net_close(struct net_device *dev)
128 {
129         netif_stop_queue(dev);
130         return 0;
131 }
132
133 /* Net device start xmit */
134 static int tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
135 {
136         struct tun_struct *tun = netdev_priv(dev);
137
138         DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len);
139
140         /* Drop packet if interface is not attached */
141         if (!tun->attached)
142                 goto drop;
143
144         /* Packet dropping */
145         if (skb_queue_len(&tun->readq) >= dev->tx_queue_len) {
146                 if (!(tun->flags & TUN_ONE_QUEUE)) {
147                         /* Normal queueing mode. */
148                         /* Packet scheduler handles dropping of further packets. */
149                         netif_stop_queue(dev);
150
151                         /* We won't see all dropped packets individually, so overrun
152                          * error is more appropriate. */
153                         dev->stats.tx_fifo_errors++;
154                 } else {
155                         /* Single queue mode.
156                          * Driver handles dropping of all packets itself. */
157                         goto drop;
158                 }
159         }
160
161         /* Queue packet */
162         skb_queue_tail(&tun->readq, skb);
163         dev->trans_start = jiffies;
164
165         /* Notify and wake up reader process */
166         if (tun->flags & TUN_FASYNC)
167                 kill_fasync(&tun->fasync, SIGIO, POLL_IN);
168         wake_up_interruptible(&tun->read_wait);
169         return 0;
170
171 drop:
172         dev->stats.tx_dropped++;
173         kfree_skb(skb);
174         return 0;
175 }
176
177 /** Add the specified Ethernet address to this multicast filter. */
178 static void
179 add_multi(u32* filter, const u8* addr)
180 {
181         int bit_nr = ether_crc(ETH_ALEN, addr) >> 26;
182         filter[bit_nr >> 5] |= 1 << (bit_nr & 31);
183 }
184
185 /** Remove the specified Ethernet addres from this multicast filter. */
186 static void
187 del_multi(u32* filter, const u8* addr)
188 {
189         int bit_nr = ether_crc(ETH_ALEN, addr) >> 26;
190         filter[bit_nr >> 5] &= ~(1 << (bit_nr & 31));
191 }
192
193 /** Update the list of multicast groups to which the network device belongs.
194  * This list is used to filter packets being sent from the character device to
195  * the network device. */
196 static void
197 tun_net_mclist(struct net_device *dev)
198 {
199         struct tun_struct *tun = netdev_priv(dev);
200         const struct dev_mc_list *mclist;
201         int i;
202         DECLARE_MAC_BUF(mac);
203         DBG(KERN_DEBUG "%s: tun_net_mclist: mc_count %d\n",
204                         dev->name, dev->mc_count);
205         memset(tun->chr_filter, 0, sizeof tun->chr_filter);
206         for (i = 0, mclist = dev->mc_list; i < dev->mc_count && mclist != NULL;
207                         i++, mclist = mclist->next) {
208                 add_multi(tun->net_filter, mclist->dmi_addr);
209                 DBG(KERN_DEBUG "%s: tun_net_mclist: %s\n",
210                     dev->name, print_mac(mac, mclist->dmi_addr));
211         }
212 }
213
214 #define MIN_MTU 68
215 #define MAX_MTU 65535
216
217 static int
218 tun_net_change_mtu(struct net_device *dev, int new_mtu)
219 {
220         if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
221                 return -EINVAL;
222         dev->mtu = new_mtu;
223         return 0;
224 }
225
226 /* Initialize net device. */
227 static void tun_net_init(struct net_device *dev)
228 {
229         struct tun_struct *tun = netdev_priv(dev);
230
231         switch (tun->flags & TUN_TYPE_MASK) {
232         case TUN_TUN_DEV:
233                 /* Point-to-Point TUN Device */
234                 dev->hard_header_len = 0;
235                 dev->addr_len = 0;
236                 dev->mtu = 1500;
237                 dev->change_mtu = tun_net_change_mtu;
238
239                 /* Zero header length */
240                 dev->type = ARPHRD_NONE;
241                 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
242                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
243                 break;
244
245         case TUN_TAP_DEV:
246                 /* Ethernet TAP Device */
247                 dev->set_multicast_list = tun_net_mclist;
248
249                 ether_setup(dev);
250                 dev->change_mtu = tun_net_change_mtu;
251
252                 /* random address already created for us by tun_set_iff, use it */
253                 memcpy(dev->dev_addr, tun->dev_addr, min(sizeof(tun->dev_addr), sizeof(dev->dev_addr)) );
254
255                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
256                 break;
257         }
258 }
259
260 /* Character device part */
261
262 /* Poll */
263 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
264 {
265         struct tun_struct *tun = file->private_data;
266         unsigned int mask = POLLOUT | POLLWRNORM;
267
268         if (!tun)
269                 return -EBADFD;
270
271         DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name);
272
273         poll_wait(file, &tun->read_wait, wait);
274
275         if (!skb_queue_empty(&tun->readq))
276                 mask |= POLLIN | POLLRDNORM;
277
278         return mask;
279 }
280
281 /* Get packet from user space buffer */
282 static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, size_t count)
283 {
284         struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) };
285         struct sk_buff *skb;
286         size_t len = count, align = 0;
287
288         if (!(tun->flags & TUN_NO_PI)) {
289                 if ((len -= sizeof(pi)) > count)
290                         return -EINVAL;
291
292                 if(memcpy_fromiovec((void *)&pi, iv, sizeof(pi)))
293                         return -EFAULT;
294         }
295
296         if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
297                 align = NET_IP_ALIGN;
298                 if (unlikely(len < ETH_HLEN))
299                         return -EINVAL;
300         }
301
302         if (!(skb = alloc_skb(len + align, GFP_KERNEL))) {
303                 tun->dev->stats.rx_dropped++;
304                 return -ENOMEM;
305         }
306
307         if (align)
308                 skb_reserve(skb, align);
309         if (memcpy_fromiovec(skb_put(skb, len), iv, len)) {
310                 tun->dev->stats.rx_dropped++;
311                 kfree_skb(skb);
312                 return -EFAULT;
313         }
314
315         switch (tun->flags & TUN_TYPE_MASK) {
316         case TUN_TUN_DEV:
317                 if (tun->flags & TUN_NO_PI) {
318                         switch (skb->data[0] & 0xf0) {
319                         case 0x40:
320                                 pi.proto = htons(ETH_P_IP);
321                                 break;
322                         case 0x60:
323                                 pi.proto = htons(ETH_P_IPV6);
324                                 break;
325                         default:
326                                 tun->dev->stats.rx_dropped++;
327                                 kfree_skb(skb);
328                                 return -EINVAL;
329                         }
330                 }
331
332                 skb_reset_mac_header(skb);
333                 skb->protocol = pi.proto;
334                 skb->dev = tun->dev;
335                 break;
336         case TUN_TAP_DEV:
337                 skb->protocol = eth_type_trans(skb, tun->dev);
338                 break;
339         };
340
341         if (tun->flags & TUN_NOCHECKSUM)
342                 skb->ip_summed = CHECKSUM_UNNECESSARY;
343
344         netif_rx_ni(skb);
345         tun->dev->last_rx = jiffies;
346
347         tun->dev->stats.rx_packets++;
348         tun->dev->stats.rx_bytes += len;
349
350         return count;
351 }
352
353 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
354                               unsigned long count, loff_t pos)
355 {
356         struct tun_struct *tun = iocb->ki_filp->private_data;
357
358         if (!tun)
359                 return -EBADFD;
360
361         DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);
362
363         return tun_get_user(tun, (struct iovec *) iv, iov_length(iv, count));
364 }
365
366 /* Put packet to the user space buffer */
367 static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
368                                        struct sk_buff *skb,
369                                        struct iovec *iv, int len)
370 {
371         struct tun_pi pi = { 0, skb->protocol };
372         ssize_t total = 0;
373
374         if (!(tun->flags & TUN_NO_PI)) {
375                 if ((len -= sizeof(pi)) < 0)
376                         return -EINVAL;
377
378                 if (len < skb->len) {
379                         /* Packet will be striped */
380                         pi.flags |= TUN_PKT_STRIP;
381                 }
382
383                 if (memcpy_toiovec(iv, (void *) &pi, sizeof(pi)))
384                         return -EFAULT;
385                 total += sizeof(pi);
386         }
387
388         len = min_t(int, skb->len, len);
389
390         skb_copy_datagram_iovec(skb, 0, iv, len);
391         total += len;
392
393         tun->dev->stats.tx_packets++;
394         tun->dev->stats.tx_bytes += len;
395
396         return total;
397 }
398
399 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
400                             unsigned long count, loff_t pos)
401 {
402         struct file *file = iocb->ki_filp;
403         struct tun_struct *tun = file->private_data;
404         DECLARE_WAITQUEUE(wait, current);
405         struct sk_buff *skb;
406         ssize_t len, ret = 0;
407         DECLARE_MAC_BUF(mac);
408
409         if (!tun)
410                 return -EBADFD;
411
412         DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
413
414         len = iov_length(iv, count);
415         if (len < 0)
416                 return -EINVAL;
417
418         add_wait_queue(&tun->read_wait, &wait);
419         while (len) {
420                 const u8 ones[ ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
421                 u8 addr[ ETH_ALEN];
422                 int bit_nr;
423
424                 current->state = TASK_INTERRUPTIBLE;
425
426                 /* Read frames from the queue */
427                 if (!(skb=skb_dequeue(&tun->readq))) {
428                         if (file->f_flags & O_NONBLOCK) {
429                                 ret = -EAGAIN;
430                                 break;
431                         }
432                         if (signal_pending(current)) {
433                                 ret = -ERESTARTSYS;
434                                 break;
435                         }
436
437                         /* Nothing to read, let's sleep */
438                         schedule();
439                         continue;
440                 }
441                 netif_wake_queue(tun->dev);
442
443                 /** Decide whether to accept this packet. This code is designed to
444                  * behave identically to an Ethernet interface. Accept the packet if
445                  * - we are promiscuous.
446                  * - the packet is addressed to us.
447                  * - the packet is broadcast.
448                  * - the packet is multicast and
449                  *   - we are multicast promiscous.
450                  *   - we belong to the multicast group.
451                  */
452                 skb_copy_from_linear_data(skb, addr, min_t(size_t, sizeof addr,
453                                                                    skb->len));
454                 bit_nr = ether_crc(sizeof addr, addr) >> 26;
455                 if ((tun->if_flags & IFF_PROMISC) ||
456                                 memcmp(addr, tun->dev_addr, sizeof addr) == 0 ||
457                                 memcmp(addr, ones, sizeof addr) == 0 ||
458                                 (((addr[0] == 1 && addr[1] == 0 && addr[2] == 0x5e) ||
459                                   (addr[0] == 0x33 && addr[1] == 0x33)) &&
460                                  ((tun->if_flags & IFF_ALLMULTI) ||
461                                   (tun->chr_filter[bit_nr >> 5] & (1 << (bit_nr & 31)))))) {
462                         DBG(KERN_DEBUG "%s: tun_chr_readv: accepted: %s\n",
463                                         tun->dev->name, print_mac(mac, addr));
464                         ret = tun_put_user(tun, skb, (struct iovec *) iv, len);
465                         kfree_skb(skb);
466                         break;
467                 } else {
468                         DBG(KERN_DEBUG "%s: tun_chr_readv: rejected: %s\n",
469                                         tun->dev->name, print_mac(mac, addr));
470                         kfree_skb(skb);
471                         continue;
472                 }
473         }
474
475         current->state = TASK_RUNNING;
476         remove_wait_queue(&tun->read_wait, &wait);
477
478         return ret;
479 }
480
481 static void tun_setup(struct net_device *dev)
482 {
483         struct tun_struct *tun = netdev_priv(dev);
484
485         skb_queue_head_init(&tun->readq);
486         init_waitqueue_head(&tun->read_wait);
487
488         tun->owner = -1;
489         tun->group = -1;
490
491         dev->open = tun_net_open;
492         dev->hard_start_xmit = tun_net_xmit;
493         dev->stop = tun_net_close;
494         dev->ethtool_ops = &tun_ethtool_ops;
495         dev->destructor = free_netdev;
496         dev->features |= NETIF_F_NETNS_LOCAL;
497 }
498
499 static struct tun_struct *tun_get_by_name(struct tun_net *tn, const char *name)
500 {
501         struct tun_struct *tun;
502
503         ASSERT_RTNL();
504         list_for_each_entry(tun, &tn->dev_list, list) {
505                 if (!strncmp(tun->dev->name, name, IFNAMSIZ))
506                     return tun;
507         }
508
509         return NULL;
510 }
511
512 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
513 {
514         struct tun_net *tn;
515         struct tun_struct *tun;
516         struct net_device *dev;
517         int err;
518
519         tn = net_generic(net, tun_net_id);
520         tun = tun_get_by_name(tn, ifr->ifr_name);
521         if (tun) {
522                 if (tun->attached)
523                         return -EBUSY;
524
525                 /* Check permissions */
526                 if (((tun->owner != -1 &&
527                       current->euid != tun->owner) ||
528                      (tun->group != -1 &&
529                       current->egid != tun->group)) &&
530                      !capable(CAP_NET_ADMIN))
531                         return -EPERM;
532         }
533         else if (__dev_get_by_name(net, ifr->ifr_name))
534                 return -EINVAL;
535         else {
536                 char *name;
537                 unsigned long flags = 0;
538
539                 err = -EINVAL;
540
541                 if (!capable(CAP_NET_ADMIN))
542                         return -EPERM;
543
544                 /* Set dev type */
545                 if (ifr->ifr_flags & IFF_TUN) {
546                         /* TUN device */
547                         flags |= TUN_TUN_DEV;
548                         name = "tun%d";
549                 } else if (ifr->ifr_flags & IFF_TAP) {
550                         /* TAP device */
551                         flags |= TUN_TAP_DEV;
552                         name = "tap%d";
553                 } else
554                         goto failed;
555
556                 if (*ifr->ifr_name)
557                         name = ifr->ifr_name;
558
559                 dev = alloc_netdev(sizeof(struct tun_struct), name,
560                                    tun_setup);
561                 if (!dev)
562                         return -ENOMEM;
563
564                 dev_net_set(dev, net);
565                 tun = netdev_priv(dev);
566                 tun->dev = dev;
567                 tun->flags = flags;
568                 /* Be promiscuous by default to maintain previous behaviour. */
569                 tun->if_flags = IFF_PROMISC;
570                 /* Generate random Ethernet address. */
571                 *(__be16 *)tun->dev_addr = htons(0x00FF);
572                 get_random_bytes(tun->dev_addr + sizeof(u16), 4);
573                 memset(tun->chr_filter, 0, sizeof tun->chr_filter);
574
575                 tun_net_init(dev);
576
577                 if (strchr(dev->name, '%')) {
578                         err = dev_alloc_name(dev, dev->name);
579                         if (err < 0)
580                                 goto err_free_dev;
581                 }
582
583                 err = register_netdevice(tun->dev);
584                 if (err < 0)
585                         goto err_free_dev;
586
587                 list_add(&tun->list, &tn->dev_list);
588         }
589
590         DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);
591
592         if (ifr->ifr_flags & IFF_NO_PI)
593                 tun->flags |= TUN_NO_PI;
594         else
595                 tun->flags &= ~TUN_NO_PI;
596
597         if (ifr->ifr_flags & IFF_ONE_QUEUE)
598                 tun->flags |= TUN_ONE_QUEUE;
599         else
600                 tun->flags &= ~TUN_ONE_QUEUE;
601
602         file->private_data = tun;
603         tun->attached = 1;
604         get_net(dev_net(tun->dev));
605
606         /* Make sure persistent devices do not get stuck in
607          * xoff state.
608          */
609         if (netif_running(tun->dev))
610                 netif_wake_queue(tun->dev);
611
612         strcpy(ifr->ifr_name, tun->dev->name);
613         return 0;
614
615  err_free_dev:
616         free_netdev(dev);
617  failed:
618         return err;
619 }
620
621 static int tun_chr_ioctl(struct inode *inode, struct file *file,
622                          unsigned int cmd, unsigned long arg)
623 {
624         struct tun_struct *tun = file->private_data;
625         void __user* argp = (void __user*)arg;
626         struct ifreq ifr;
627         DECLARE_MAC_BUF(mac);
628
629         if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
630                 if (copy_from_user(&ifr, argp, sizeof ifr))
631                         return -EFAULT;
632
633         if (cmd == TUNSETIFF && !tun) {
634                 int err;
635
636                 ifr.ifr_name[IFNAMSIZ-1] = '\0';
637
638                 rtnl_lock();
639                 err = tun_set_iff(current->nsproxy->net_ns, file, &ifr);
640                 rtnl_unlock();
641
642                 if (err)
643                         return err;
644
645                 if (copy_to_user(argp, &ifr, sizeof(ifr)))
646                         return -EFAULT;
647                 return 0;
648         }
649
650         if (!tun)
651                 return -EBADFD;
652
653         DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd);
654
655         switch (cmd) {
656         case TUNSETNOCSUM:
657                 /* Disable/Enable checksum */
658                 if (arg)
659                         tun->flags |= TUN_NOCHECKSUM;
660                 else
661                         tun->flags &= ~TUN_NOCHECKSUM;
662
663                 DBG(KERN_INFO "%s: checksum %s\n",
664                     tun->dev->name, arg ? "disabled" : "enabled");
665                 break;
666
667         case TUNSETPERSIST:
668                 /* Disable/Enable persist mode */
669                 if (arg)
670                         tun->flags |= TUN_PERSIST;
671                 else
672                         tun->flags &= ~TUN_PERSIST;
673
674                 DBG(KERN_INFO "%s: persist %s\n",
675                     tun->dev->name, arg ? "enabled" : "disabled");
676                 break;
677
678         case TUNSETOWNER:
679                 /* Set owner of the device */
680                 tun->owner = (uid_t) arg;
681
682                 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner);
683                 break;
684
685         case TUNSETGROUP:
686                 /* Set group of the device */
687                 tun->group= (gid_t) arg;
688
689                 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group);
690                 break;
691
692         case TUNSETLINK:
693         {
694                 int ret;
695
696                 /* Only allow setting the type when the interface is down */
697                 rtnl_lock();
698                 if (tun->dev->flags & IFF_UP) {
699                         DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
700                                 tun->dev->name);
701                         ret = -EBUSY;
702                 } else {
703                         tun->dev->type = (int) arg;
704                         DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
705                         ret = 0;
706                 }
707                 rtnl_unlock();
708                 return ret;
709         }
710
711 #ifdef TUN_DEBUG
712         case TUNSETDEBUG:
713                 tun->debug = arg;
714                 break;
715 #endif
716
717         case SIOCGIFFLAGS:
718                 ifr.ifr_flags = tun->if_flags;
719                 if (copy_to_user( argp, &ifr, sizeof ifr))
720                         return -EFAULT;
721                 return 0;
722
723         case SIOCSIFFLAGS:
724                 /** Set the character device's interface flags. Currently only
725                  * IFF_PROMISC and IFF_ALLMULTI are used. */
726                 tun->if_flags = ifr.ifr_flags;
727                 DBG(KERN_INFO "%s: interface flags 0x%lx\n",
728                                 tun->dev->name, tun->if_flags);
729                 return 0;
730
731         case SIOCGIFHWADDR:
732                 /* Note: the actual net device's address may be different */
733                 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev_addr,
734                                 min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr));
735                 if (copy_to_user( argp, &ifr, sizeof ifr))
736                         return -EFAULT;
737                 return 0;
738
739         case SIOCSIFHWADDR:
740         {
741                 /* try to set the actual net device's hw address */
742                 int ret;
743
744                 rtnl_lock();
745                 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
746                 rtnl_unlock();
747
748                 if (ret == 0) {
749                         /** Set the character device's hardware address. This is used when
750                          * filtering packets being sent from the network device to the character
751                          * device. */
752                         memcpy(tun->dev_addr, ifr.ifr_hwaddr.sa_data,
753                                         min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr));
754                         DBG(KERN_DEBUG "%s: set hardware address: %x:%x:%x:%x:%x:%x\n",
755                                         tun->dev->name,
756                                         tun->dev_addr[0], tun->dev_addr[1], tun->dev_addr[2],
757                                         tun->dev_addr[3], tun->dev_addr[4], tun->dev_addr[5]);
758                 }
759
760                 return  ret;
761         }
762
763         case SIOCADDMULTI:
764                 /** Add the specified group to the character device's multicast filter
765                  * list. */
766                 rtnl_lock();
767                 netif_tx_lock_bh(tun->dev);
768                 add_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data);
769                 netif_tx_unlock_bh(tun->dev);
770                 rtnl_unlock();
771
772                 DBG(KERN_DEBUG "%s: add multi: %s\n",
773                     tun->dev->name, print_mac(mac, ifr.ifr_hwaddr.sa_data));
774                 return 0;
775
776         case SIOCDELMULTI:
777                 /** Remove the specified group from the character device's multicast
778                  * filter list. */
779                 rtnl_lock();
780                 netif_tx_lock_bh(tun->dev);
781                 del_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data);
782                 netif_tx_unlock_bh(tun->dev);
783                 rtnl_unlock();
784
785                 DBG(KERN_DEBUG "%s: del multi: %s\n",
786                     tun->dev->name, print_mac(mac, ifr.ifr_hwaddr.sa_data));
787                 return 0;
788
789         default:
790                 return -EINVAL;
791         };
792
793         return 0;
794 }
795
796 static int tun_chr_fasync(int fd, struct file *file, int on)
797 {
798         struct tun_struct *tun = file->private_data;
799         int ret;
800
801         if (!tun)
802                 return -EBADFD;
803
804         DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);
805
806         lock_kernel();
807         if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
808                 goto out;
809
810         if (on) {
811                 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
812                 if (ret)
813                         goto out;
814                 tun->flags |= TUN_FASYNC;
815         } else
816                 tun->flags &= ~TUN_FASYNC;
817         ret = 0;
818 out:
819         unlock_kernel();
820         return ret;
821 }
822
823 static int tun_chr_open(struct inode *inode, struct file * file)
824 {
825         cycle_kernel_lock();
826         DBG1(KERN_INFO "tunX: tun_chr_open\n");
827         file->private_data = NULL;
828         return 0;
829 }
830
831 static int tun_chr_close(struct inode *inode, struct file *file)
832 {
833         struct tun_struct *tun = file->private_data;
834
835         if (!tun)
836                 return 0;
837
838         DBG(KERN_INFO "%s: tun_chr_close\n", tun->dev->name);
839
840         tun_chr_fasync(-1, file, 0);
841
842         rtnl_lock();
843
844         /* Detach from net device */
845         file->private_data = NULL;
846         tun->attached = 0;
847         put_net(dev_net(tun->dev));
848
849         /* Drop read queue */
850         skb_queue_purge(&tun->readq);
851
852         if (!(tun->flags & TUN_PERSIST)) {
853                 list_del(&tun->list);
854                 unregister_netdevice(tun->dev);
855         }
856
857         rtnl_unlock();
858
859         return 0;
860 }
861
862 static const struct file_operations tun_fops = {
863         .owner  = THIS_MODULE,
864         .llseek = no_llseek,
865         .read  = do_sync_read,
866         .aio_read  = tun_chr_aio_read,
867         .write = do_sync_write,
868         .aio_write = tun_chr_aio_write,
869         .poll   = tun_chr_poll,
870         .ioctl  = tun_chr_ioctl,
871         .open   = tun_chr_open,
872         .release = tun_chr_close,
873         .fasync = tun_chr_fasync
874 };
875
876 static struct miscdevice tun_miscdev = {
877         .minor = TUN_MINOR,
878         .name = "tun",
879         .fops = &tun_fops,
880 };
881
882 /* ethtool interface */
883
884 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
885 {
886         cmd->supported          = 0;
887         cmd->advertising        = 0;
888         cmd->speed              = SPEED_10;
889         cmd->duplex             = DUPLEX_FULL;
890         cmd->port               = PORT_TP;
891         cmd->phy_address        = 0;
892         cmd->transceiver        = XCVR_INTERNAL;
893         cmd->autoneg            = AUTONEG_DISABLE;
894         cmd->maxtxpkt           = 0;
895         cmd->maxrxpkt           = 0;
896         return 0;
897 }
898
899 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
900 {
901         struct tun_struct *tun = netdev_priv(dev);
902
903         strcpy(info->driver, DRV_NAME);
904         strcpy(info->version, DRV_VERSION);
905         strcpy(info->fw_version, "N/A");
906
907         switch (tun->flags & TUN_TYPE_MASK) {
908         case TUN_TUN_DEV:
909                 strcpy(info->bus_info, "tun");
910                 break;
911         case TUN_TAP_DEV:
912                 strcpy(info->bus_info, "tap");
913                 break;
914         }
915 }
916
917 static u32 tun_get_msglevel(struct net_device *dev)
918 {
919 #ifdef TUN_DEBUG
920         struct tun_struct *tun = netdev_priv(dev);
921         return tun->debug;
922 #else
923         return -EOPNOTSUPP;
924 #endif
925 }
926
927 static void tun_set_msglevel(struct net_device *dev, u32 value)
928 {
929 #ifdef TUN_DEBUG
930         struct tun_struct *tun = netdev_priv(dev);
931         tun->debug = value;
932 #endif
933 }
934
935 static u32 tun_get_link(struct net_device *dev)
936 {
937         struct tun_struct *tun = netdev_priv(dev);
938         return tun->attached;
939 }
940
941 static u32 tun_get_rx_csum(struct net_device *dev)
942 {
943         struct tun_struct *tun = netdev_priv(dev);
944         return (tun->flags & TUN_NOCHECKSUM) == 0;
945 }
946
947 static int tun_set_rx_csum(struct net_device *dev, u32 data)
948 {
949         struct tun_struct *tun = netdev_priv(dev);
950         if (data)
951                 tun->flags &= ~TUN_NOCHECKSUM;
952         else
953                 tun->flags |= TUN_NOCHECKSUM;
954         return 0;
955 }
956
957 static const struct ethtool_ops tun_ethtool_ops = {
958         .get_settings   = tun_get_settings,
959         .get_drvinfo    = tun_get_drvinfo,
960         .get_msglevel   = tun_get_msglevel,
961         .set_msglevel   = tun_set_msglevel,
962         .get_link       = tun_get_link,
963         .get_rx_csum    = tun_get_rx_csum,
964         .set_rx_csum    = tun_set_rx_csum
965 };
966
967 static int tun_init_net(struct net *net)
968 {
969         struct tun_net *tn;
970
971         tn = kmalloc(sizeof(*tn), GFP_KERNEL);
972         if (tn == NULL)
973                 return -ENOMEM;
974
975         INIT_LIST_HEAD(&tn->dev_list);
976
977         if (net_assign_generic(net, tun_net_id, tn)) {
978                 kfree(tn);
979                 return -ENOMEM;
980         }
981
982         return 0;
983 }
984
985 static void tun_exit_net(struct net *net)
986 {
987         struct tun_net *tn;
988         struct tun_struct *tun, *nxt;
989
990         tn = net_generic(net, tun_net_id);
991
992         rtnl_lock();
993         list_for_each_entry_safe(tun, nxt, &tn->dev_list, list) {
994                 DBG(KERN_INFO "%s cleaned up\n", tun->dev->name);
995                 unregister_netdevice(tun->dev);
996         }
997         rtnl_unlock();
998
999         kfree(tn);
1000 }
1001
1002 static struct pernet_operations tun_net_ops = {
1003         .init = tun_init_net,
1004         .exit = tun_exit_net,
1005 };
1006
1007 static int __init tun_init(void)
1008 {
1009         int ret = 0;
1010
1011         printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
1012         printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);
1013
1014         ret = register_pernet_gen_device(&tun_net_id, &tun_net_ops);
1015         if (ret) {
1016                 printk(KERN_ERR "tun: Can't register pernet ops\n");
1017                 goto err_pernet;
1018         }
1019
1020         ret = misc_register(&tun_miscdev);
1021         if (ret) {
1022                 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
1023                 goto err_misc;
1024         }
1025         return 0;
1026
1027 err_misc:
1028         unregister_pernet_gen_device(tun_net_id, &tun_net_ops);
1029 err_pernet:
1030         return ret;
1031 }
1032
1033 static void tun_cleanup(void)
1034 {
1035         misc_deregister(&tun_miscdev);
1036         unregister_pernet_gen_device(tun_net_id, &tun_net_ops);
1037 }
1038
1039 module_init(tun_init);
1040 module_exit(tun_cleanup);
1041 MODULE_DESCRIPTION(DRV_DESCRIPTION);
1042 MODULE_AUTHOR(DRV_COPYRIGHT);
1043 MODULE_LICENSE("GPL");
1044 MODULE_ALIAS_MISCDEV(TUN_MINOR);