net: Remove BKL from tun
[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  *  Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14
22  *    Add TUNSETLINK ioctl to set the link encapsulation
23  *
24  *  Mark Smith <markzzzsmith@yahoo.com.au>
25  *    Use random_ether_addr() for tap MAC address.
26  *
27  *  Harald Roelle <harald.roelle@ifi.lmu.de>  2004/04/20
28  *    Fixes in packet dropping, queue length setting and queue wakeup.
29  *    Increased default tx queue length.
30  *    Added ethtool API.
31  *    Minor cleanups
32  *
33  *  Daniel Podlejski <underley@underley.eu.org>
34  *    Modifications for 2.3.99-pre5 kernel.
35  */
36
37 #define DRV_NAME        "tun"
38 #define DRV_VERSION     "1.6"
39 #define DRV_DESCRIPTION "Universal TUN/TAP device driver"
40 #define DRV_COPYRIGHT   "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>"
41
42 #include <linux/module.h>
43 #include <linux/errno.h>
44 #include <linux/kernel.h>
45 #include <linux/major.h>
46 #include <linux/slab.h>
47 #include <linux/poll.h>
48 #include <linux/fcntl.h>
49 #include <linux/init.h>
50 #include <linux/skbuff.h>
51 #include <linux/netdevice.h>
52 #include <linux/etherdevice.h>
53 #include <linux/miscdevice.h>
54 #include <linux/ethtool.h>
55 #include <linux/rtnetlink.h>
56 #include <linux/if.h>
57 #include <linux/if_arp.h>
58 #include <linux/if_ether.h>
59 #include <linux/if_tun.h>
60 #include <linux/crc32.h>
61 #include <linux/nsproxy.h>
62 #include <linux/virtio_net.h>
63 #include <net/net_namespace.h>
64 #include <net/netns/generic.h>
65 #include <net/rtnetlink.h>
66 #include <net/sock.h>
67
68 #include <asm/system.h>
69 #include <asm/uaccess.h>
70
71 /* Uncomment to enable debugging */
72 /* #define TUN_DEBUG 1 */
73
74 #ifdef TUN_DEBUG
75 static int debug;
76
77 #define DBG  if(tun->debug)printk
78 #define DBG1 if(debug==2)printk
79 #else
80 #define DBG( a... )
81 #define DBG1( a... )
82 #endif
83
84 #define FLT_EXACT_COUNT 8
85 struct tap_filter {
86         unsigned int    count;    /* Number of addrs. Zero means disabled */
87         u32             mask[2];  /* Mask of the hashed addrs */
88         unsigned char   addr[FLT_EXACT_COUNT][ETH_ALEN];
89 };
90
91 struct tun_file {
92         atomic_t count;
93         struct tun_struct *tun;
94         struct net *net;
95 };
96
97 struct tun_sock;
98
99 struct tun_struct {
100         struct tun_file         *tfile;
101         unsigned int            flags;
102         uid_t                   owner;
103         gid_t                   group;
104
105         struct net_device       *dev;
106         struct fasync_struct    *fasync;
107
108         struct tap_filter       txflt;
109         struct socket           socket;
110
111 #ifdef TUN_DEBUG
112         int debug;
113 #endif
114 };
115
116 struct tun_sock {
117         struct sock             sk;
118         struct tun_struct       *tun;
119 };
120
121 static inline struct tun_sock *tun_sk(struct sock *sk)
122 {
123         return container_of(sk, struct tun_sock, sk);
124 }
125
126 static int tun_attach(struct tun_struct *tun, struct file *file)
127 {
128         struct tun_file *tfile = file->private_data;
129         int err;
130
131         ASSERT_RTNL();
132
133         netif_tx_lock_bh(tun->dev);
134
135         err = -EINVAL;
136         if (tfile->tun)
137                 goto out;
138
139         err = -EBUSY;
140         if (tun->tfile)
141                 goto out;
142
143         err = 0;
144         tfile->tun = tun;
145         tun->tfile = tfile;
146         dev_hold(tun->dev);
147         sock_hold(tun->socket.sk);
148         atomic_inc(&tfile->count);
149
150 out:
151         netif_tx_unlock_bh(tun->dev);
152         return err;
153 }
154
155 static void __tun_detach(struct tun_struct *tun)
156 {
157         /* Detach from net device */
158         netif_tx_lock_bh(tun->dev);
159         tun->tfile = NULL;
160         netif_tx_unlock_bh(tun->dev);
161
162         /* Drop read queue */
163         skb_queue_purge(&tun->socket.sk->sk_receive_queue);
164
165         /* Drop the extra count on the net device */
166         dev_put(tun->dev);
167 }
168
169 static void tun_detach(struct tun_struct *tun)
170 {
171         rtnl_lock();
172         __tun_detach(tun);
173         rtnl_unlock();
174 }
175
176 static struct tun_struct *__tun_get(struct tun_file *tfile)
177 {
178         struct tun_struct *tun = NULL;
179
180         if (atomic_inc_not_zero(&tfile->count))
181                 tun = tfile->tun;
182
183         return tun;
184 }
185
186 static struct tun_struct *tun_get(struct file *file)
187 {
188         return __tun_get(file->private_data);
189 }
190
191 static void tun_put(struct tun_struct *tun)
192 {
193         struct tun_file *tfile = tun->tfile;
194
195         if (atomic_dec_and_test(&tfile->count))
196                 tun_detach(tfile->tun);
197 }
198
199 /* TAP filterting */
200 static void addr_hash_set(u32 *mask, const u8 *addr)
201 {
202         int n = ether_crc(ETH_ALEN, addr) >> 26;
203         mask[n >> 5] |= (1 << (n & 31));
204 }
205
206 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
207 {
208         int n = ether_crc(ETH_ALEN, addr) >> 26;
209         return mask[n >> 5] & (1 << (n & 31));
210 }
211
212 static int update_filter(struct tap_filter *filter, void __user *arg)
213 {
214         struct { u8 u[ETH_ALEN]; } *addr;
215         struct tun_filter uf;
216         int err, alen, n, nexact;
217
218         if (copy_from_user(&uf, arg, sizeof(uf)))
219                 return -EFAULT;
220
221         if (!uf.count) {
222                 /* Disabled */
223                 filter->count = 0;
224                 return 0;
225         }
226
227         alen = ETH_ALEN * uf.count;
228         addr = kmalloc(alen, GFP_KERNEL);
229         if (!addr)
230                 return -ENOMEM;
231
232         if (copy_from_user(addr, arg + sizeof(uf), alen)) {
233                 err = -EFAULT;
234                 goto done;
235         }
236
237         /* The filter is updated without holding any locks. Which is
238          * perfectly safe. We disable it first and in the worst
239          * case we'll accept a few undesired packets. */
240         filter->count = 0;
241         wmb();
242
243         /* Use first set of addresses as an exact filter */
244         for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
245                 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
246
247         nexact = n;
248
249         /* Remaining multicast addresses are hashed,
250          * unicast will leave the filter disabled. */
251         memset(filter->mask, 0, sizeof(filter->mask));
252         for (; n < uf.count; n++) {
253                 if (!is_multicast_ether_addr(addr[n].u)) {
254                         err = 0; /* no filter */
255                         goto done;
256                 }
257                 addr_hash_set(filter->mask, addr[n].u);
258         }
259
260         /* For ALLMULTI just set the mask to all ones.
261          * This overrides the mask populated above. */
262         if ((uf.flags & TUN_FLT_ALLMULTI))
263                 memset(filter->mask, ~0, sizeof(filter->mask));
264
265         /* Now enable the filter */
266         wmb();
267         filter->count = nexact;
268
269         /* Return the number of exact filters */
270         err = nexact;
271
272 done:
273         kfree(addr);
274         return err;
275 }
276
277 /* Returns: 0 - drop, !=0 - accept */
278 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
279 {
280         /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
281          * at this point. */
282         struct ethhdr *eh = (struct ethhdr *) skb->data;
283         int i;
284
285         /* Exact match */
286         for (i = 0; i < filter->count; i++)
287                 if (!compare_ether_addr(eh->h_dest, filter->addr[i]))
288                         return 1;
289
290         /* Inexact match (multicast only) */
291         if (is_multicast_ether_addr(eh->h_dest))
292                 return addr_hash_test(filter->mask, eh->h_dest);
293
294         return 0;
295 }
296
297 /*
298  * Checks whether the packet is accepted or not.
299  * Returns: 0 - drop, !=0 - accept
300  */
301 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
302 {
303         if (!filter->count)
304                 return 1;
305
306         return run_filter(filter, skb);
307 }
308
309 /* Network device part of the driver */
310
311 static const struct ethtool_ops tun_ethtool_ops;
312
313 /* Net device detach from fd. */
314 static void tun_net_uninit(struct net_device *dev)
315 {
316         struct tun_struct *tun = netdev_priv(dev);
317         struct tun_file *tfile = tun->tfile;
318
319         /* Inform the methods they need to stop using the dev.
320          */
321         if (tfile) {
322                 wake_up_all(&tun->socket.wait);
323                 if (atomic_dec_and_test(&tfile->count))
324                         __tun_detach(tun);
325         }
326 }
327
328 static void tun_free_netdev(struct net_device *dev)
329 {
330         struct tun_struct *tun = netdev_priv(dev);
331
332         sock_put(tun->socket.sk);
333 }
334
335 /* Net device open. */
336 static int tun_net_open(struct net_device *dev)
337 {
338         netif_start_queue(dev);
339         return 0;
340 }
341
342 /* Net device close. */
343 static int tun_net_close(struct net_device *dev)
344 {
345         netif_stop_queue(dev);
346         return 0;
347 }
348
349 /* Net device start xmit */
350 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
351 {
352         struct tun_struct *tun = netdev_priv(dev);
353
354         DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len);
355
356         /* Drop packet if interface is not attached */
357         if (!tun->tfile)
358                 goto drop;
359
360         /* Drop if the filter does not like it.
361          * This is a noop if the filter is disabled.
362          * Filter can be enabled only for the TAP devices. */
363         if (!check_filter(&tun->txflt, skb))
364                 goto drop;
365
366         if (skb_queue_len(&tun->socket.sk->sk_receive_queue) >= dev->tx_queue_len) {
367                 if (!(tun->flags & TUN_ONE_QUEUE)) {
368                         /* Normal queueing mode. */
369                         /* Packet scheduler handles dropping of further packets. */
370                         netif_stop_queue(dev);
371
372                         /* We won't see all dropped packets individually, so overrun
373                          * error is more appropriate. */
374                         dev->stats.tx_fifo_errors++;
375                 } else {
376                         /* Single queue mode.
377                          * Driver handles dropping of all packets itself. */
378                         goto drop;
379                 }
380         }
381
382         /* Enqueue packet */
383         skb_queue_tail(&tun->socket.sk->sk_receive_queue, skb);
384         dev->trans_start = jiffies;
385
386         /* Notify and wake up reader process */
387         if (tun->flags & TUN_FASYNC)
388                 kill_fasync(&tun->fasync, SIGIO, POLL_IN);
389         wake_up_interruptible(&tun->socket.wait);
390         return NETDEV_TX_OK;
391
392 drop:
393         dev->stats.tx_dropped++;
394         kfree_skb(skb);
395         return NETDEV_TX_OK;
396 }
397
398 static void tun_net_mclist(struct net_device *dev)
399 {
400         /*
401          * This callback is supposed to deal with mc filter in
402          * _rx_ path and has nothing to do with the _tx_ path.
403          * In rx path we always accept everything userspace gives us.
404          */
405         return;
406 }
407
408 #define MIN_MTU 68
409 #define MAX_MTU 65535
410
411 static int
412 tun_net_change_mtu(struct net_device *dev, int new_mtu)
413 {
414         if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
415                 return -EINVAL;
416         dev->mtu = new_mtu;
417         return 0;
418 }
419
420 static const struct net_device_ops tun_netdev_ops = {
421         .ndo_uninit             = tun_net_uninit,
422         .ndo_open               = tun_net_open,
423         .ndo_stop               = tun_net_close,
424         .ndo_start_xmit         = tun_net_xmit,
425         .ndo_change_mtu         = tun_net_change_mtu,
426 };
427
428 static const struct net_device_ops tap_netdev_ops = {
429         .ndo_uninit             = tun_net_uninit,
430         .ndo_open               = tun_net_open,
431         .ndo_stop               = tun_net_close,
432         .ndo_start_xmit         = tun_net_xmit,
433         .ndo_change_mtu         = tun_net_change_mtu,
434         .ndo_set_multicast_list = tun_net_mclist,
435         .ndo_set_mac_address    = eth_mac_addr,
436         .ndo_validate_addr      = eth_validate_addr,
437 };
438
439 /* Initialize net device. */
440 static void tun_net_init(struct net_device *dev)
441 {
442         struct tun_struct *tun = netdev_priv(dev);
443
444         switch (tun->flags & TUN_TYPE_MASK) {
445         case TUN_TUN_DEV:
446                 dev->netdev_ops = &tun_netdev_ops;
447
448                 /* Point-to-Point TUN Device */
449                 dev->hard_header_len = 0;
450                 dev->addr_len = 0;
451                 dev->mtu = 1500;
452
453                 /* Zero header length */
454                 dev->type = ARPHRD_NONE;
455                 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
456                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
457                 break;
458
459         case TUN_TAP_DEV:
460                 dev->netdev_ops = &tap_netdev_ops;
461                 /* Ethernet TAP Device */
462                 ether_setup(dev);
463
464                 random_ether_addr(dev->dev_addr);
465
466                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
467                 break;
468         }
469 }
470
471 /* Character device part */
472
473 /* Poll */
474 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
475 {
476         struct tun_file *tfile = file->private_data;
477         struct tun_struct *tun = __tun_get(tfile);
478         struct sock *sk;
479         unsigned int mask = 0;
480
481         if (!tun)
482                 return POLLERR;
483
484         sk = tun->socket.sk;
485
486         DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name);
487
488         poll_wait(file, &tun->socket.wait, wait);
489
490         if (!skb_queue_empty(&sk->sk_receive_queue))
491                 mask |= POLLIN | POLLRDNORM;
492
493         if (sock_writeable(sk) ||
494             (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
495              sock_writeable(sk)))
496                 mask |= POLLOUT | POLLWRNORM;
497
498         if (tun->dev->reg_state != NETREG_REGISTERED)
499                 mask = POLLERR;
500
501         tun_put(tun);
502         return mask;
503 }
504
505 /* prepad is the amount to reserve at front.  len is length after that.
506  * linear is a hint as to how much to copy (usually headers). */
507 static inline struct sk_buff *tun_alloc_skb(struct tun_struct *tun,
508                                             size_t prepad, size_t len,
509                                             size_t linear, int noblock)
510 {
511         struct sock *sk = tun->socket.sk;
512         struct sk_buff *skb;
513         int err;
514
515         /* Under a page?  Don't bother with paged skb. */
516         if (prepad + len < PAGE_SIZE || !linear)
517                 linear = len;
518
519         skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
520                                    &err);
521         if (!skb)
522                 return ERR_PTR(err);
523
524         skb_reserve(skb, prepad);
525         skb_put(skb, linear);
526         skb->data_len = len - linear;
527         skb->len += len - linear;
528
529         return skb;
530 }
531
532 /* Get packet from user space buffer */
533 static __inline__ ssize_t tun_get_user(struct tun_struct *tun,
534                                        const struct iovec *iv, size_t count,
535                                        int noblock)
536 {
537         struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
538         struct sk_buff *skb;
539         size_t len = count, align = 0;
540         struct virtio_net_hdr gso = { 0 };
541         int offset = 0;
542
543         if (!(tun->flags & TUN_NO_PI)) {
544                 if ((len -= sizeof(pi)) > count)
545                         return -EINVAL;
546
547                 if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
548                         return -EFAULT;
549                 offset += sizeof(pi);
550         }
551
552         if (tun->flags & TUN_VNET_HDR) {
553                 if ((len -= sizeof(gso)) > count)
554                         return -EINVAL;
555
556                 if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
557                         return -EFAULT;
558
559                 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
560                     gso.csum_start + gso.csum_offset + 2 > gso.hdr_len)
561                         gso.hdr_len = gso.csum_start + gso.csum_offset + 2;
562
563                 if (gso.hdr_len > len)
564                         return -EINVAL;
565                 offset += sizeof(gso);
566         }
567
568         if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
569                 align = NET_IP_ALIGN;
570                 if (unlikely(len < ETH_HLEN ||
571                              (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
572                         return -EINVAL;
573         }
574
575         skb = tun_alloc_skb(tun, align, len, gso.hdr_len, noblock);
576         if (IS_ERR(skb)) {
577                 if (PTR_ERR(skb) != -EAGAIN)
578                         tun->dev->stats.rx_dropped++;
579                 return PTR_ERR(skb);
580         }
581
582         if (skb_copy_datagram_from_iovec(skb, 0, iv, offset, len)) {
583                 tun->dev->stats.rx_dropped++;
584                 kfree_skb(skb);
585                 return -EFAULT;
586         }
587
588         if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
589                 if (!skb_partial_csum_set(skb, gso.csum_start,
590                                           gso.csum_offset)) {
591                         tun->dev->stats.rx_frame_errors++;
592                         kfree_skb(skb);
593                         return -EINVAL;
594                 }
595         } else if (tun->flags & TUN_NOCHECKSUM)
596                 skb->ip_summed = CHECKSUM_UNNECESSARY;
597
598         switch (tun->flags & TUN_TYPE_MASK) {
599         case TUN_TUN_DEV:
600                 if (tun->flags & TUN_NO_PI) {
601                         switch (skb->data[0] & 0xf0) {
602                         case 0x40:
603                                 pi.proto = htons(ETH_P_IP);
604                                 break;
605                         case 0x60:
606                                 pi.proto = htons(ETH_P_IPV6);
607                                 break;
608                         default:
609                                 tun->dev->stats.rx_dropped++;
610                                 kfree_skb(skb);
611                                 return -EINVAL;
612                         }
613                 }
614
615                 skb_reset_mac_header(skb);
616                 skb->protocol = pi.proto;
617                 skb->dev = tun->dev;
618                 break;
619         case TUN_TAP_DEV:
620                 skb->protocol = eth_type_trans(skb, tun->dev);
621                 break;
622         };
623
624         if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
625                 pr_debug("GSO!\n");
626                 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
627                 case VIRTIO_NET_HDR_GSO_TCPV4:
628                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
629                         break;
630                 case VIRTIO_NET_HDR_GSO_TCPV6:
631                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
632                         break;
633                 case VIRTIO_NET_HDR_GSO_UDP:
634                         skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
635                         break;
636                 default:
637                         tun->dev->stats.rx_frame_errors++;
638                         kfree_skb(skb);
639                         return -EINVAL;
640                 }
641
642                 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
643                         skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
644
645                 skb_shinfo(skb)->gso_size = gso.gso_size;
646                 if (skb_shinfo(skb)->gso_size == 0) {
647                         tun->dev->stats.rx_frame_errors++;
648                         kfree_skb(skb);
649                         return -EINVAL;
650                 }
651
652                 /* Header must be checked, and gso_segs computed. */
653                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
654                 skb_shinfo(skb)->gso_segs = 0;
655         }
656
657         netif_rx_ni(skb);
658
659         tun->dev->stats.rx_packets++;
660         tun->dev->stats.rx_bytes += len;
661
662         return count;
663 }
664
665 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
666                               unsigned long count, loff_t pos)
667 {
668         struct file *file = iocb->ki_filp;
669         struct tun_struct *tun = tun_get(file);
670         ssize_t result;
671
672         if (!tun)
673                 return -EBADFD;
674
675         DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);
676
677         result = tun_get_user(tun, iv, iov_length(iv, count),
678                               file->f_flags & O_NONBLOCK);
679
680         tun_put(tun);
681         return result;
682 }
683
684 /* Put packet to the user space buffer */
685 static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
686                                        struct sk_buff *skb,
687                                        const struct iovec *iv, int len)
688 {
689         struct tun_pi pi = { 0, skb->protocol };
690         ssize_t total = 0;
691
692         if (!(tun->flags & TUN_NO_PI)) {
693                 if ((len -= sizeof(pi)) < 0)
694                         return -EINVAL;
695
696                 if (len < skb->len) {
697                         /* Packet will be striped */
698                         pi.flags |= TUN_PKT_STRIP;
699                 }
700
701                 if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi)))
702                         return -EFAULT;
703                 total += sizeof(pi);
704         }
705
706         if (tun->flags & TUN_VNET_HDR) {
707                 struct virtio_net_hdr gso = { 0 }; /* no info leak */
708                 if ((len -= sizeof(gso)) < 0)
709                         return -EINVAL;
710
711                 if (skb_is_gso(skb)) {
712                         struct skb_shared_info *sinfo = skb_shinfo(skb);
713
714                         /* This is a hint as to how much should be linear. */
715                         gso.hdr_len = skb_headlen(skb);
716                         gso.gso_size = sinfo->gso_size;
717                         if (sinfo->gso_type & SKB_GSO_TCPV4)
718                                 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
719                         else if (sinfo->gso_type & SKB_GSO_TCPV6)
720                                 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
721                         else if (sinfo->gso_type & SKB_GSO_UDP)
722                                 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
723                         else
724                                 BUG();
725                         if (sinfo->gso_type & SKB_GSO_TCP_ECN)
726                                 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
727                 } else
728                         gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
729
730                 if (skb->ip_summed == CHECKSUM_PARTIAL) {
731                         gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
732                         gso.csum_start = skb->csum_start - skb_headroom(skb);
733                         gso.csum_offset = skb->csum_offset;
734                 } /* else everything is zero */
735
736                 if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
737                                                sizeof(gso))))
738                         return -EFAULT;
739                 total += sizeof(gso);
740         }
741
742         len = min_t(int, skb->len, len);
743
744         skb_copy_datagram_const_iovec(skb, 0, iv, total, len);
745         total += len;
746
747         tun->dev->stats.tx_packets++;
748         tun->dev->stats.tx_bytes += len;
749
750         return total;
751 }
752
753 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
754                             unsigned long count, loff_t pos)
755 {
756         struct file *file = iocb->ki_filp;
757         struct tun_file *tfile = file->private_data;
758         struct tun_struct *tun = __tun_get(tfile);
759         DECLARE_WAITQUEUE(wait, current);
760         struct sk_buff *skb;
761         ssize_t len, ret = 0;
762
763         if (!tun)
764                 return -EBADFD;
765
766         DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
767
768         len = iov_length(iv, count);
769         if (len < 0) {
770                 ret = -EINVAL;
771                 goto out;
772         }
773
774         add_wait_queue(&tun->socket.wait, &wait);
775         while (len) {
776                 current->state = TASK_INTERRUPTIBLE;
777
778                 /* Read frames from the queue */
779                 if (!(skb=skb_dequeue(&tun->socket.sk->sk_receive_queue))) {
780                         if (file->f_flags & O_NONBLOCK) {
781                                 ret = -EAGAIN;
782                                 break;
783                         }
784                         if (signal_pending(current)) {
785                                 ret = -ERESTARTSYS;
786                                 break;
787                         }
788                         if (tun->dev->reg_state != NETREG_REGISTERED) {
789                                 ret = -EIO;
790                                 break;
791                         }
792
793                         /* Nothing to read, let's sleep */
794                         schedule();
795                         continue;
796                 }
797                 netif_wake_queue(tun->dev);
798
799                 ret = tun_put_user(tun, skb, iv, len);
800                 kfree_skb(skb);
801                 break;
802         }
803
804         current->state = TASK_RUNNING;
805         remove_wait_queue(&tun->socket.wait, &wait);
806
807 out:
808         tun_put(tun);
809         return ret;
810 }
811
812 static void tun_setup(struct net_device *dev)
813 {
814         struct tun_struct *tun = netdev_priv(dev);
815
816         tun->owner = -1;
817         tun->group = -1;
818
819         dev->ethtool_ops = &tun_ethtool_ops;
820         dev->destructor = tun_free_netdev;
821 }
822
823 /* Trivial set of netlink ops to allow deleting tun or tap
824  * device with netlink.
825  */
826 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
827 {
828         return -EINVAL;
829 }
830
831 static struct rtnl_link_ops tun_link_ops __read_mostly = {
832         .kind           = DRV_NAME,
833         .priv_size      = sizeof(struct tun_struct),
834         .setup          = tun_setup,
835         .validate       = tun_validate,
836 };
837
838 static void tun_sock_write_space(struct sock *sk)
839 {
840         struct tun_struct *tun;
841
842         if (!sock_writeable(sk))
843                 return;
844
845         if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
846                 return;
847
848         if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
849                 wake_up_interruptible_sync(sk->sk_sleep);
850
851         tun = container_of(sk, struct tun_sock, sk)->tun;
852         kill_fasync(&tun->fasync, SIGIO, POLL_OUT);
853 }
854
855 static void tun_sock_destruct(struct sock *sk)
856 {
857         free_netdev(container_of(sk, struct tun_sock, sk)->tun->dev);
858 }
859
860 static struct proto tun_proto = {
861         .name           = "tun",
862         .owner          = THIS_MODULE,
863         .obj_size       = sizeof(struct tun_sock),
864 };
865
866 static int tun_flags(struct tun_struct *tun)
867 {
868         int flags = 0;
869
870         if (tun->flags & TUN_TUN_DEV)
871                 flags |= IFF_TUN;
872         else
873                 flags |= IFF_TAP;
874
875         if (tun->flags & TUN_NO_PI)
876                 flags |= IFF_NO_PI;
877
878         if (tun->flags & TUN_ONE_QUEUE)
879                 flags |= IFF_ONE_QUEUE;
880
881         if (tun->flags & TUN_VNET_HDR)
882                 flags |= IFF_VNET_HDR;
883
884         return flags;
885 }
886
887 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
888                               char *buf)
889 {
890         struct tun_struct *tun = netdev_priv(to_net_dev(dev));
891         return sprintf(buf, "0x%x\n", tun_flags(tun));
892 }
893
894 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
895                               char *buf)
896 {
897         struct tun_struct *tun = netdev_priv(to_net_dev(dev));
898         return sprintf(buf, "%d\n", tun->owner);
899 }
900
901 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
902                               char *buf)
903 {
904         struct tun_struct *tun = netdev_priv(to_net_dev(dev));
905         return sprintf(buf, "%d\n", tun->group);
906 }
907
908 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
909 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
910 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
911
912 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
913 {
914         struct sock *sk;
915         struct tun_struct *tun;
916         struct net_device *dev;
917         int err;
918
919         dev = __dev_get_by_name(net, ifr->ifr_name);
920         if (dev) {
921                 const struct cred *cred = current_cred();
922
923                 if (ifr->ifr_flags & IFF_TUN_EXCL)
924                         return -EBUSY;
925                 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
926                         tun = netdev_priv(dev);
927                 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
928                         tun = netdev_priv(dev);
929                 else
930                         return -EINVAL;
931
932                 if (((tun->owner != -1 && cred->euid != tun->owner) ||
933                      (tun->group != -1 && !in_egroup_p(tun->group))) &&
934                     !capable(CAP_NET_ADMIN))
935                         return -EPERM;
936                 err = security_tun_dev_attach(tun->socket.sk);
937                 if (err < 0)
938                         return err;
939
940                 err = tun_attach(tun, file);
941                 if (err < 0)
942                         return err;
943         }
944         else {
945                 char *name;
946                 unsigned long flags = 0;
947
948                 if (!capable(CAP_NET_ADMIN))
949                         return -EPERM;
950                 err = security_tun_dev_create();
951                 if (err < 0)
952                         return err;
953
954                 /* Set dev type */
955                 if (ifr->ifr_flags & IFF_TUN) {
956                         /* TUN device */
957                         flags |= TUN_TUN_DEV;
958                         name = "tun%d";
959                 } else if (ifr->ifr_flags & IFF_TAP) {
960                         /* TAP device */
961                         flags |= TUN_TAP_DEV;
962                         name = "tap%d";
963                 } else
964                         return -EINVAL;
965
966                 if (*ifr->ifr_name)
967                         name = ifr->ifr_name;
968
969                 dev = alloc_netdev(sizeof(struct tun_struct), name,
970                                    tun_setup);
971                 if (!dev)
972                         return -ENOMEM;
973
974                 dev_net_set(dev, net);
975                 dev->rtnl_link_ops = &tun_link_ops;
976
977                 tun = netdev_priv(dev);
978                 tun->dev = dev;
979                 tun->flags = flags;
980                 tun->txflt.count = 0;
981
982                 err = -ENOMEM;
983                 sk = sk_alloc(net, AF_UNSPEC, GFP_KERNEL, &tun_proto);
984                 if (!sk)
985                         goto err_free_dev;
986
987                 init_waitqueue_head(&tun->socket.wait);
988                 sock_init_data(&tun->socket, sk);
989                 sk->sk_write_space = tun_sock_write_space;
990                 sk->sk_sndbuf = INT_MAX;
991
992                 container_of(sk, struct tun_sock, sk)->tun = tun;
993
994                 security_tun_dev_post_create(sk);
995
996                 tun_net_init(dev);
997
998                 if (strchr(dev->name, '%')) {
999                         err = dev_alloc_name(dev, dev->name);
1000                         if (err < 0)
1001                                 goto err_free_sk;
1002                 }
1003
1004                 err = register_netdevice(tun->dev);
1005                 if (err < 0)
1006                         goto err_free_sk;
1007
1008                 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
1009                     device_create_file(&tun->dev->dev, &dev_attr_owner) ||
1010                     device_create_file(&tun->dev->dev, &dev_attr_group))
1011                         printk(KERN_ERR "Failed to create tun sysfs files\n");
1012
1013                 sk->sk_destruct = tun_sock_destruct;
1014
1015                 err = tun_attach(tun, file);
1016                 if (err < 0)
1017                         goto failed;
1018         }
1019
1020         DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);
1021
1022         if (ifr->ifr_flags & IFF_NO_PI)
1023                 tun->flags |= TUN_NO_PI;
1024         else
1025                 tun->flags &= ~TUN_NO_PI;
1026
1027         if (ifr->ifr_flags & IFF_ONE_QUEUE)
1028                 tun->flags |= TUN_ONE_QUEUE;
1029         else
1030                 tun->flags &= ~TUN_ONE_QUEUE;
1031
1032         if (ifr->ifr_flags & IFF_VNET_HDR)
1033                 tun->flags |= TUN_VNET_HDR;
1034         else
1035                 tun->flags &= ~TUN_VNET_HDR;
1036
1037         /* Make sure persistent devices do not get stuck in
1038          * xoff state.
1039          */
1040         if (netif_running(tun->dev))
1041                 netif_wake_queue(tun->dev);
1042
1043         strcpy(ifr->ifr_name, tun->dev->name);
1044         return 0;
1045
1046  err_free_sk:
1047         sock_put(sk);
1048  err_free_dev:
1049         free_netdev(dev);
1050  failed:
1051         return err;
1052 }
1053
1054 static int tun_get_iff(struct net *net, struct tun_struct *tun,
1055                        struct ifreq *ifr)
1056 {
1057         DBG(KERN_INFO "%s: tun_get_iff\n", tun->dev->name);
1058
1059         strcpy(ifr->ifr_name, tun->dev->name);
1060
1061         ifr->ifr_flags = tun_flags(tun);
1062
1063         return 0;
1064 }
1065
1066 /* This is like a cut-down ethtool ops, except done via tun fd so no
1067  * privs required. */
1068 static int set_offload(struct net_device *dev, unsigned long arg)
1069 {
1070         unsigned int old_features, features;
1071
1072         old_features = dev->features;
1073         /* Unset features, set them as we chew on the arg. */
1074         features = (old_features & ~(NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST
1075                                     |NETIF_F_TSO_ECN|NETIF_F_TSO|NETIF_F_TSO6
1076                                     |NETIF_F_UFO));
1077
1078         if (arg & TUN_F_CSUM) {
1079                 features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1080                 arg &= ~TUN_F_CSUM;
1081
1082                 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1083                         if (arg & TUN_F_TSO_ECN) {
1084                                 features |= NETIF_F_TSO_ECN;
1085                                 arg &= ~TUN_F_TSO_ECN;
1086                         }
1087                         if (arg & TUN_F_TSO4)
1088                                 features |= NETIF_F_TSO;
1089                         if (arg & TUN_F_TSO6)
1090                                 features |= NETIF_F_TSO6;
1091                         arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1092                 }
1093
1094                 if (arg & TUN_F_UFO) {
1095                         features |= NETIF_F_UFO;
1096                         arg &= ~TUN_F_UFO;
1097                 }
1098         }
1099
1100         /* This gives the user a way to test for new features in future by
1101          * trying to set them. */
1102         if (arg)
1103                 return -EINVAL;
1104
1105         dev->features = features;
1106         if (old_features != dev->features)
1107                 netdev_features_change(dev);
1108
1109         return 0;
1110 }
1111
1112 static long tun_chr_ioctl(struct file *file, unsigned int cmd,
1113                           unsigned long arg)
1114 {
1115         struct tun_file *tfile = file->private_data;
1116         struct tun_struct *tun;
1117         void __user* argp = (void __user*)arg;
1118         struct ifreq ifr;
1119         int sndbuf;
1120         int ret;
1121
1122         if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
1123                 if (copy_from_user(&ifr, argp, sizeof ifr))
1124                         return -EFAULT;
1125
1126         if (cmd == TUNGETFEATURES) {
1127                 /* Currently this just means: "what IFF flags are valid?".
1128                  * This is needed because we never checked for invalid flags on
1129                  * TUNSETIFF. */
1130                 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
1131                                 IFF_VNET_HDR,
1132                                 (unsigned int __user*)argp);
1133         }
1134
1135         rtnl_lock();
1136
1137         tun = __tun_get(tfile);
1138         if (cmd == TUNSETIFF && !tun) {
1139                 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1140
1141                 ret = tun_set_iff(tfile->net, file, &ifr);
1142
1143                 if (ret)
1144                         goto unlock;
1145
1146                 if (copy_to_user(argp, &ifr, sizeof(ifr)))
1147                         ret = -EFAULT;
1148                 goto unlock;
1149         }
1150
1151         ret = -EBADFD;
1152         if (!tun)
1153                 goto unlock;
1154
1155         DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd);
1156
1157         ret = 0;
1158         switch (cmd) {
1159         case TUNGETIFF:
1160                 ret = tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1161                 if (ret)
1162                         break;
1163
1164                 if (copy_to_user(argp, &ifr, sizeof(ifr)))
1165                         ret = -EFAULT;
1166                 break;
1167
1168         case TUNSETNOCSUM:
1169                 /* Disable/Enable checksum */
1170                 if (arg)
1171                         tun->flags |= TUN_NOCHECKSUM;
1172                 else
1173                         tun->flags &= ~TUN_NOCHECKSUM;
1174
1175                 DBG(KERN_INFO "%s: checksum %s\n",
1176                     tun->dev->name, arg ? "disabled" : "enabled");
1177                 break;
1178
1179         case TUNSETPERSIST:
1180                 /* Disable/Enable persist mode */
1181                 if (arg)
1182                         tun->flags |= TUN_PERSIST;
1183                 else
1184                         tun->flags &= ~TUN_PERSIST;
1185
1186                 DBG(KERN_INFO "%s: persist %s\n",
1187                     tun->dev->name, arg ? "enabled" : "disabled");
1188                 break;
1189
1190         case TUNSETOWNER:
1191                 /* Set owner of the device */
1192                 tun->owner = (uid_t) arg;
1193
1194                 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner);
1195                 break;
1196
1197         case TUNSETGROUP:
1198                 /* Set group of the device */
1199                 tun->group= (gid_t) arg;
1200
1201                 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group);
1202                 break;
1203
1204         case TUNSETLINK:
1205                 /* Only allow setting the type when the interface is down */
1206                 if (tun->dev->flags & IFF_UP) {
1207                         DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
1208                                 tun->dev->name);
1209                         ret = -EBUSY;
1210                 } else {
1211                         tun->dev->type = (int) arg;
1212                         DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
1213                         ret = 0;
1214                 }
1215                 break;
1216
1217 #ifdef TUN_DEBUG
1218         case TUNSETDEBUG:
1219                 tun->debug = arg;
1220                 break;
1221 #endif
1222         case TUNSETOFFLOAD:
1223                 ret = set_offload(tun->dev, arg);
1224                 break;
1225
1226         case TUNSETTXFILTER:
1227                 /* Can be set only for TAPs */
1228                 ret = -EINVAL;
1229                 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1230                         break;
1231                 ret = update_filter(&tun->txflt, (void __user *)arg);
1232                 break;
1233
1234         case SIOCGIFHWADDR:
1235                 /* Get hw addres */
1236                 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
1237                 ifr.ifr_hwaddr.sa_family = tun->dev->type;
1238                 if (copy_to_user(argp, &ifr, sizeof ifr))
1239                         ret = -EFAULT;
1240                 break;
1241
1242         case SIOCSIFHWADDR:
1243                 /* Set hw address */
1244                 DBG(KERN_DEBUG "%s: set hw address: %pM\n",
1245                         tun->dev->name, ifr.ifr_hwaddr.sa_data);
1246
1247                 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
1248                 break;
1249
1250         case TUNGETSNDBUF:
1251                 sndbuf = tun->socket.sk->sk_sndbuf;
1252                 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
1253                         ret = -EFAULT;
1254                 break;
1255
1256         case TUNSETSNDBUF:
1257                 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
1258                         ret = -EFAULT;
1259                         break;
1260                 }
1261
1262                 tun->socket.sk->sk_sndbuf = sndbuf;
1263                 break;
1264
1265         default:
1266                 ret = -EINVAL;
1267                 break;
1268         };
1269
1270 unlock:
1271         rtnl_unlock();
1272         if (tun)
1273                 tun_put(tun);
1274         return ret;
1275 }
1276
1277 static int tun_chr_fasync(int fd, struct file *file, int on)
1278 {
1279         struct tun_struct *tun = tun_get(file);
1280         int ret;
1281
1282         if (!tun)
1283                 return -EBADFD;
1284
1285         DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);
1286
1287         if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
1288                 goto out;
1289
1290         if (on) {
1291                 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
1292                 if (ret)
1293                         goto out;
1294                 tun->flags |= TUN_FASYNC;
1295         } else
1296                 tun->flags &= ~TUN_FASYNC;
1297         ret = 0;
1298 out:
1299         tun_put(tun);
1300         return ret;
1301 }
1302
1303 static int tun_chr_open(struct inode *inode, struct file * file)
1304 {
1305         struct tun_file *tfile;
1306
1307         DBG1(KERN_INFO "tunX: tun_chr_open\n");
1308
1309         tfile = kmalloc(sizeof(*tfile), GFP_KERNEL);
1310         if (!tfile)
1311                 return -ENOMEM;
1312         atomic_set(&tfile->count, 0);
1313         tfile->tun = NULL;
1314         tfile->net = get_net(current->nsproxy->net_ns);
1315         file->private_data = tfile;
1316         return 0;
1317 }
1318
1319 static int tun_chr_close(struct inode *inode, struct file *file)
1320 {
1321         struct tun_file *tfile = file->private_data;
1322         struct tun_struct *tun;
1323
1324         tun = __tun_get(tfile);
1325         if (tun) {
1326                 struct net_device *dev = tun->dev;
1327
1328                 DBG(KERN_INFO "%s: tun_chr_close\n", dev->name);
1329
1330                 __tun_detach(tun);
1331
1332                 /* If desireable, unregister the netdevice. */
1333                 if (!(tun->flags & TUN_PERSIST)) {
1334                         rtnl_lock();
1335                         if (dev->reg_state == NETREG_REGISTERED)
1336                                 unregister_netdevice(dev);
1337                         rtnl_unlock();
1338                 }
1339         }
1340
1341         tun = tfile->tun;
1342         if (tun)
1343                 sock_put(tun->socket.sk);
1344
1345         put_net(tfile->net);
1346         kfree(tfile);
1347
1348         return 0;
1349 }
1350
1351 static const struct file_operations tun_fops = {
1352         .owner  = THIS_MODULE,
1353         .llseek = no_llseek,
1354         .read  = do_sync_read,
1355         .aio_read  = tun_chr_aio_read,
1356         .write = do_sync_write,
1357         .aio_write = tun_chr_aio_write,
1358         .poll   = tun_chr_poll,
1359         .unlocked_ioctl = tun_chr_ioctl,
1360         .open   = tun_chr_open,
1361         .release = tun_chr_close,
1362         .fasync = tun_chr_fasync
1363 };
1364
1365 static struct miscdevice tun_miscdev = {
1366         .minor = TUN_MINOR,
1367         .name = "tun",
1368         .nodename = "net/tun",
1369         .fops = &tun_fops,
1370 };
1371
1372 /* ethtool interface */
1373
1374 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1375 {
1376         cmd->supported          = 0;
1377         cmd->advertising        = 0;
1378         cmd->speed              = SPEED_10;
1379         cmd->duplex             = DUPLEX_FULL;
1380         cmd->port               = PORT_TP;
1381         cmd->phy_address        = 0;
1382         cmd->transceiver        = XCVR_INTERNAL;
1383         cmd->autoneg            = AUTONEG_DISABLE;
1384         cmd->maxtxpkt           = 0;
1385         cmd->maxrxpkt           = 0;
1386         return 0;
1387 }
1388
1389 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
1390 {
1391         struct tun_struct *tun = netdev_priv(dev);
1392
1393         strcpy(info->driver, DRV_NAME);
1394         strcpy(info->version, DRV_VERSION);
1395         strcpy(info->fw_version, "N/A");
1396
1397         switch (tun->flags & TUN_TYPE_MASK) {
1398         case TUN_TUN_DEV:
1399                 strcpy(info->bus_info, "tun");
1400                 break;
1401         case TUN_TAP_DEV:
1402                 strcpy(info->bus_info, "tap");
1403                 break;
1404         }
1405 }
1406
1407 static u32 tun_get_msglevel(struct net_device *dev)
1408 {
1409 #ifdef TUN_DEBUG
1410         struct tun_struct *tun = netdev_priv(dev);
1411         return tun->debug;
1412 #else
1413         return -EOPNOTSUPP;
1414 #endif
1415 }
1416
1417 static void tun_set_msglevel(struct net_device *dev, u32 value)
1418 {
1419 #ifdef TUN_DEBUG
1420         struct tun_struct *tun = netdev_priv(dev);
1421         tun->debug = value;
1422 #endif
1423 }
1424
1425 static u32 tun_get_link(struct net_device *dev)
1426 {
1427         struct tun_struct *tun = netdev_priv(dev);
1428         return !!tun->tfile;
1429 }
1430
1431 static u32 tun_get_rx_csum(struct net_device *dev)
1432 {
1433         struct tun_struct *tun = netdev_priv(dev);
1434         return (tun->flags & TUN_NOCHECKSUM) == 0;
1435 }
1436
1437 static int tun_set_rx_csum(struct net_device *dev, u32 data)
1438 {
1439         struct tun_struct *tun = netdev_priv(dev);
1440         if (data)
1441                 tun->flags &= ~TUN_NOCHECKSUM;
1442         else
1443                 tun->flags |= TUN_NOCHECKSUM;
1444         return 0;
1445 }
1446
1447 static const struct ethtool_ops tun_ethtool_ops = {
1448         .get_settings   = tun_get_settings,
1449         .get_drvinfo    = tun_get_drvinfo,
1450         .get_msglevel   = tun_get_msglevel,
1451         .set_msglevel   = tun_set_msglevel,
1452         .get_link       = tun_get_link,
1453         .get_rx_csum    = tun_get_rx_csum,
1454         .set_rx_csum    = tun_set_rx_csum
1455 };
1456
1457
1458 static int __init tun_init(void)
1459 {
1460         int ret = 0;
1461
1462         printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
1463         printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);
1464
1465         ret = rtnl_link_register(&tun_link_ops);
1466         if (ret) {
1467                 printk(KERN_ERR "tun: Can't register link_ops\n");
1468                 goto err_linkops;
1469         }
1470
1471         ret = misc_register(&tun_miscdev);
1472         if (ret) {
1473                 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
1474                 goto err_misc;
1475         }
1476         return  0;
1477 err_misc:
1478         rtnl_link_unregister(&tun_link_ops);
1479 err_linkops:
1480         return ret;
1481 }
1482
1483 static void tun_cleanup(void)
1484 {
1485         misc_deregister(&tun_miscdev);
1486         rtnl_link_unregister(&tun_link_ops);
1487 }
1488
1489 module_init(tun_init);
1490 module_exit(tun_cleanup);
1491 MODULE_DESCRIPTION(DRV_DESCRIPTION);
1492 MODULE_AUTHOR(DRV_COPYRIGHT);
1493 MODULE_LICENSE("GPL");
1494 MODULE_ALIAS_MISCDEV(TUN_MINOR);