Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
[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/smp_lock.h>
48 #include <linux/poll.h>
49 #include <linux/fcntl.h>
50 #include <linux/init.h>
51 #include <linux/skbuff.h>
52 #include <linux/netdevice.h>
53 #include <linux/etherdevice.h>
54 #include <linux/miscdevice.h>
55 #include <linux/ethtool.h>
56 #include <linux/rtnetlink.h>
57 #include <linux/if.h>
58 #include <linux/if_arp.h>
59 #include <linux/if_ether.h>
60 #include <linux/if_tun.h>
61 #include <linux/crc32.h>
62 #include <linux/nsproxy.h>
63 #include <linux/virtio_net.h>
64 #include <net/net_namespace.h>
65 #include <net/netns/generic.h>
66 #include <net/rtnetlink.h>
67 #include <net/sock.h>
68
69 #include <asm/system.h>
70 #include <asm/uaccess.h>
71
72 /* Uncomment to enable debugging */
73 /* #define TUN_DEBUG 1 */
74
75 #ifdef TUN_DEBUG
76 static int debug;
77
78 #define DBG  if(tun->debug)printk
79 #define DBG1 if(debug==2)printk
80 #else
81 #define DBG( a... )
82 #define DBG1( a... )
83 #endif
84
85 #define FLT_EXACT_COUNT 8
86 struct tap_filter {
87         unsigned int    count;    /* Number of addrs. Zero means disabled */
88         u32             mask[2];  /* Mask of the hashed addrs */
89         unsigned char   addr[FLT_EXACT_COUNT][ETH_ALEN];
90 };
91
92 struct tun_file {
93         atomic_t count;
94         struct tun_struct *tun;
95         struct net *net;
96 };
97
98 struct tun_sock;
99
100 struct tun_struct {
101         struct tun_file         *tfile;
102         unsigned int            flags;
103         uid_t                   owner;
104         gid_t                   group;
105
106         struct net_device       *dev;
107         struct fasync_struct    *fasync;
108
109         struct tap_filter       txflt;
110         struct socket           socket;
111
112 #ifdef TUN_DEBUG
113         int debug;
114 #endif
115 };
116
117 struct tun_sock {
118         struct sock             sk;
119         struct tun_struct       *tun;
120 };
121
122 static inline struct tun_sock *tun_sk(struct sock *sk)
123 {
124         return container_of(sk, struct tun_sock, sk);
125 }
126
127 static int tun_attach(struct tun_struct *tun, struct file *file)
128 {
129         struct tun_file *tfile = file->private_data;
130         int err;
131
132         ASSERT_RTNL();
133
134         netif_tx_lock_bh(tun->dev);
135
136         err = -EINVAL;
137         if (tfile->tun)
138                 goto out;
139
140         err = -EBUSY;
141         if (tun->tfile)
142                 goto out;
143
144         err = 0;
145         tfile->tun = tun;
146         tun->tfile = tfile;
147         dev_hold(tun->dev);
148         sock_hold(tun->socket.sk);
149         atomic_inc(&tfile->count);
150
151 out:
152         netif_tx_unlock_bh(tun->dev);
153         return err;
154 }
155
156 static void __tun_detach(struct tun_struct *tun)
157 {
158         /* Detach from net device */
159         netif_tx_lock_bh(tun->dev);
160         tun->tfile = NULL;
161         netif_tx_unlock_bh(tun->dev);
162
163         /* Drop read queue */
164         skb_queue_purge(&tun->socket.sk->sk_receive_queue);
165
166         /* Drop the extra count on the net device */
167         dev_put(tun->dev);
168 }
169
170 static void tun_detach(struct tun_struct *tun)
171 {
172         rtnl_lock();
173         __tun_detach(tun);
174         rtnl_unlock();
175 }
176
177 static struct tun_struct *__tun_get(struct tun_file *tfile)
178 {
179         struct tun_struct *tun = NULL;
180
181         if (atomic_inc_not_zero(&tfile->count))
182                 tun = tfile->tun;
183
184         return tun;
185 }
186
187 static struct tun_struct *tun_get(struct file *file)
188 {
189         return __tun_get(file->private_data);
190 }
191
192 static void tun_put(struct tun_struct *tun)
193 {
194         struct tun_file *tfile = tun->tfile;
195
196         if (atomic_dec_and_test(&tfile->count))
197                 tun_detach(tfile->tun);
198 }
199
200 /* TAP filterting */
201 static void addr_hash_set(u32 *mask, const u8 *addr)
202 {
203         int n = ether_crc(ETH_ALEN, addr) >> 26;
204         mask[n >> 5] |= (1 << (n & 31));
205 }
206
207 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
208 {
209         int n = ether_crc(ETH_ALEN, addr) >> 26;
210         return mask[n >> 5] & (1 << (n & 31));
211 }
212
213 static int update_filter(struct tap_filter *filter, void __user *arg)
214 {
215         struct { u8 u[ETH_ALEN]; } *addr;
216         struct tun_filter uf;
217         int err, alen, n, nexact;
218
219         if (copy_from_user(&uf, arg, sizeof(uf)))
220                 return -EFAULT;
221
222         if (!uf.count) {
223                 /* Disabled */
224                 filter->count = 0;
225                 return 0;
226         }
227
228         alen = ETH_ALEN * uf.count;
229         addr = kmalloc(alen, GFP_KERNEL);
230         if (!addr)
231                 return -ENOMEM;
232
233         if (copy_from_user(addr, arg + sizeof(uf), alen)) {
234                 err = -EFAULT;
235                 goto done;
236         }
237
238         /* The filter is updated without holding any locks. Which is
239          * perfectly safe. We disable it first and in the worst
240          * case we'll accept a few undesired packets. */
241         filter->count = 0;
242         wmb();
243
244         /* Use first set of addresses as an exact filter */
245         for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
246                 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
247
248         nexact = n;
249
250         /* Remaining multicast addresses are hashed,
251          * unicast will leave the filter disabled. */
252         memset(filter->mask, 0, sizeof(filter->mask));
253         for (; n < uf.count; n++) {
254                 if (!is_multicast_ether_addr(addr[n].u)) {
255                         err = 0; /* no filter */
256                         goto done;
257                 }
258                 addr_hash_set(filter->mask, addr[n].u);
259         }
260
261         /* For ALLMULTI just set the mask to all ones.
262          * This overrides the mask populated above. */
263         if ((uf.flags & TUN_FLT_ALLMULTI))
264                 memset(filter->mask, ~0, sizeof(filter->mask));
265
266         /* Now enable the filter */
267         wmb();
268         filter->count = nexact;
269
270         /* Return the number of exact filters */
271         err = nexact;
272
273 done:
274         kfree(addr);
275         return err;
276 }
277
278 /* Returns: 0 - drop, !=0 - accept */
279 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
280 {
281         /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
282          * at this point. */
283         struct ethhdr *eh = (struct ethhdr *) skb->data;
284         int i;
285
286         /* Exact match */
287         for (i = 0; i < filter->count; i++)
288                 if (!compare_ether_addr(eh->h_dest, filter->addr[i]))
289                         return 1;
290
291         /* Inexact match (multicast only) */
292         if (is_multicast_ether_addr(eh->h_dest))
293                 return addr_hash_test(filter->mask, eh->h_dest);
294
295         return 0;
296 }
297
298 /*
299  * Checks whether the packet is accepted or not.
300  * Returns: 0 - drop, !=0 - accept
301  */
302 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
303 {
304         if (!filter->count)
305                 return 1;
306
307         return run_filter(filter, skb);
308 }
309
310 /* Network device part of the driver */
311
312 static const struct ethtool_ops tun_ethtool_ops;
313
314 /* Net device detach from fd. */
315 static void tun_net_uninit(struct net_device *dev)
316 {
317         struct tun_struct *tun = netdev_priv(dev);
318         struct tun_file *tfile = tun->tfile;
319
320         /* Inform the methods they need to stop using the dev.
321          */
322         if (tfile) {
323                 wake_up_all(&tun->socket.wait);
324                 if (atomic_dec_and_test(&tfile->count))
325                         __tun_detach(tun);
326         }
327 }
328
329 static void tun_free_netdev(struct net_device *dev)
330 {
331         struct tun_struct *tun = netdev_priv(dev);
332
333         sock_put(tun->socket.sk);
334 }
335
336 /* Net device open. */
337 static int tun_net_open(struct net_device *dev)
338 {
339         netif_start_queue(dev);
340         return 0;
341 }
342
343 /* Net device close. */
344 static int tun_net_close(struct net_device *dev)
345 {
346         netif_stop_queue(dev);
347         return 0;
348 }
349
350 /* Net device start xmit */
351 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
352 {
353         struct tun_struct *tun = netdev_priv(dev);
354
355         DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len);
356
357         /* Drop packet if interface is not attached */
358         if (!tun->tfile)
359                 goto drop;
360
361         /* Drop if the filter does not like it.
362          * This is a noop if the filter is disabled.
363          * Filter can be enabled only for the TAP devices. */
364         if (!check_filter(&tun->txflt, skb))
365                 goto drop;
366
367         if (skb_queue_len(&tun->socket.sk->sk_receive_queue) >= dev->tx_queue_len) {
368                 if (!(tun->flags & TUN_ONE_QUEUE)) {
369                         /* Normal queueing mode. */
370                         /* Packet scheduler handles dropping of further packets. */
371                         netif_stop_queue(dev);
372
373                         /* We won't see all dropped packets individually, so overrun
374                          * error is more appropriate. */
375                         dev->stats.tx_fifo_errors++;
376                 } else {
377                         /* Single queue mode.
378                          * Driver handles dropping of all packets itself. */
379                         goto drop;
380                 }
381         }
382
383         /* Enqueue packet */
384         skb_queue_tail(&tun->socket.sk->sk_receive_queue, skb);
385         dev->trans_start = jiffies;
386
387         /* Notify and wake up reader process */
388         if (tun->flags & TUN_FASYNC)
389                 kill_fasync(&tun->fasync, SIGIO, POLL_IN);
390         wake_up_interruptible(&tun->socket.wait);
391         return NETDEV_TX_OK;
392
393 drop:
394         dev->stats.tx_dropped++;
395         kfree_skb(skb);
396         return NETDEV_TX_OK;
397 }
398
399 static void tun_net_mclist(struct net_device *dev)
400 {
401         /*
402          * This callback is supposed to deal with mc filter in
403          * _rx_ path and has nothing to do with the _tx_ path.
404          * In rx path we always accept everything userspace gives us.
405          */
406         return;
407 }
408
409 #define MIN_MTU 68
410 #define MAX_MTU 65535
411
412 static int
413 tun_net_change_mtu(struct net_device *dev, int new_mtu)
414 {
415         if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
416                 return -EINVAL;
417         dev->mtu = new_mtu;
418         return 0;
419 }
420
421 static const struct net_device_ops tun_netdev_ops = {
422         .ndo_uninit             = tun_net_uninit,
423         .ndo_open               = tun_net_open,
424         .ndo_stop               = tun_net_close,
425         .ndo_start_xmit         = tun_net_xmit,
426         .ndo_change_mtu         = tun_net_change_mtu,
427 };
428
429 static const struct net_device_ops tap_netdev_ops = {
430         .ndo_uninit             = tun_net_uninit,
431         .ndo_open               = tun_net_open,
432         .ndo_stop               = tun_net_close,
433         .ndo_start_xmit         = tun_net_xmit,
434         .ndo_change_mtu         = tun_net_change_mtu,
435         .ndo_set_multicast_list = tun_net_mclist,
436         .ndo_set_mac_address    = eth_mac_addr,
437         .ndo_validate_addr      = eth_validate_addr,
438 };
439
440 /* Initialize net device. */
441 static void tun_net_init(struct net_device *dev)
442 {
443         struct tun_struct *tun = netdev_priv(dev);
444
445         switch (tun->flags & TUN_TYPE_MASK) {
446         case TUN_TUN_DEV:
447                 dev->netdev_ops = &tun_netdev_ops;
448
449                 /* Point-to-Point TUN Device */
450                 dev->hard_header_len = 0;
451                 dev->addr_len = 0;
452                 dev->mtu = 1500;
453
454                 /* Zero header length */
455                 dev->type = ARPHRD_NONE;
456                 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
457                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
458                 break;
459
460         case TUN_TAP_DEV:
461                 dev->netdev_ops = &tap_netdev_ops;
462                 /* Ethernet TAP Device */
463                 ether_setup(dev);
464
465                 random_ether_addr(dev->dev_addr);
466
467                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
468                 break;
469         }
470 }
471
472 /* Character device part */
473
474 /* Poll */
475 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
476 {
477         struct tun_file *tfile = file->private_data;
478         struct tun_struct *tun = __tun_get(tfile);
479         struct sock *sk;
480         unsigned int mask = 0;
481
482         if (!tun)
483                 return POLLERR;
484
485         sk = tun->socket.sk;
486
487         DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name);
488
489         poll_wait(file, &tun->socket.wait, wait);
490
491         if (!skb_queue_empty(&sk->sk_receive_queue))
492                 mask |= POLLIN | POLLRDNORM;
493
494         if (sock_writeable(sk) ||
495             (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
496              sock_writeable(sk)))
497                 mask |= POLLOUT | POLLWRNORM;
498
499         if (tun->dev->reg_state != NETREG_REGISTERED)
500                 mask = POLLERR;
501
502         tun_put(tun);
503         return mask;
504 }
505
506 /* prepad is the amount to reserve at front.  len is length after that.
507  * linear is a hint as to how much to copy (usually headers). */
508 static inline struct sk_buff *tun_alloc_skb(struct tun_struct *tun,
509                                             size_t prepad, size_t len,
510                                             size_t linear, int noblock)
511 {
512         struct sock *sk = tun->socket.sk;
513         struct sk_buff *skb;
514         int err;
515
516         /* Under a page?  Don't bother with paged skb. */
517         if (prepad + len < PAGE_SIZE || !linear)
518                 linear = len;
519
520         skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
521                                    &err);
522         if (!skb)
523                 return ERR_PTR(err);
524
525         skb_reserve(skb, prepad);
526         skb_put(skb, linear);
527         skb->data_len = len - linear;
528         skb->len += len - linear;
529
530         return skb;
531 }
532
533 /* Get packet from user space buffer */
534 static __inline__ ssize_t tun_get_user(struct tun_struct *tun,
535                                        const struct iovec *iv, size_t count,
536                                        int noblock)
537 {
538         struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
539         struct sk_buff *skb;
540         size_t len = count, align = 0;
541         struct virtio_net_hdr gso = { 0 };
542         int offset = 0;
543
544         if (!(tun->flags & TUN_NO_PI)) {
545                 if ((len -= sizeof(pi)) > count)
546                         return -EINVAL;
547
548                 if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
549                         return -EFAULT;
550                 offset += sizeof(pi);
551         }
552
553         if (tun->flags & TUN_VNET_HDR) {
554                 if ((len -= sizeof(gso)) > count)
555                         return -EINVAL;
556
557                 if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
558                         return -EFAULT;
559
560                 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
561                     gso.csum_start + gso.csum_offset + 2 > gso.hdr_len)
562                         gso.hdr_len = gso.csum_start + gso.csum_offset + 2;
563
564                 if (gso.hdr_len > len)
565                         return -EINVAL;
566                 offset += sizeof(gso);
567         }
568
569         if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
570                 align = NET_IP_ALIGN;
571                 if (unlikely(len < ETH_HLEN ||
572                              (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
573                         return -EINVAL;
574         }
575
576         skb = tun_alloc_skb(tun, align, len, gso.hdr_len, noblock);
577         if (IS_ERR(skb)) {
578                 if (PTR_ERR(skb) != -EAGAIN)
579                         tun->dev->stats.rx_dropped++;
580                 return PTR_ERR(skb);
581         }
582
583         if (skb_copy_datagram_from_iovec(skb, 0, iv, offset, len)) {
584                 tun->dev->stats.rx_dropped++;
585                 kfree_skb(skb);
586                 return -EFAULT;
587         }
588
589         if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
590                 if (!skb_partial_csum_set(skb, gso.csum_start,
591                                           gso.csum_offset)) {
592                         tun->dev->stats.rx_frame_errors++;
593                         kfree_skb(skb);
594                         return -EINVAL;
595                 }
596         } else if (tun->flags & TUN_NOCHECKSUM)
597                 skb->ip_summed = CHECKSUM_UNNECESSARY;
598
599         switch (tun->flags & TUN_TYPE_MASK) {
600         case TUN_TUN_DEV:
601                 if (tun->flags & TUN_NO_PI) {
602                         switch (skb->data[0] & 0xf0) {
603                         case 0x40:
604                                 pi.proto = htons(ETH_P_IP);
605                                 break;
606                         case 0x60:
607                                 pi.proto = htons(ETH_P_IPV6);
608                                 break;
609                         default:
610                                 tun->dev->stats.rx_dropped++;
611                                 kfree_skb(skb);
612                                 return -EINVAL;
613                         }
614                 }
615
616                 skb_reset_mac_header(skb);
617                 skb->protocol = pi.proto;
618                 skb->dev = tun->dev;
619                 break;
620         case TUN_TAP_DEV:
621                 skb->protocol = eth_type_trans(skb, tun->dev);
622                 break;
623         };
624
625         if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
626                 pr_debug("GSO!\n");
627                 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
628                 case VIRTIO_NET_HDR_GSO_TCPV4:
629                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
630                         break;
631                 case VIRTIO_NET_HDR_GSO_TCPV6:
632                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
633                         break;
634                 case VIRTIO_NET_HDR_GSO_UDP:
635                         skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
636                         break;
637                 default:
638                         tun->dev->stats.rx_frame_errors++;
639                         kfree_skb(skb);
640                         return -EINVAL;
641                 }
642
643                 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
644                         skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
645
646                 skb_shinfo(skb)->gso_size = gso.gso_size;
647                 if (skb_shinfo(skb)->gso_size == 0) {
648                         tun->dev->stats.rx_frame_errors++;
649                         kfree_skb(skb);
650                         return -EINVAL;
651                 }
652
653                 /* Header must be checked, and gso_segs computed. */
654                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
655                 skb_shinfo(skb)->gso_segs = 0;
656         }
657
658         netif_rx_ni(skb);
659
660         tun->dev->stats.rx_packets++;
661         tun->dev->stats.rx_bytes += len;
662
663         return count;
664 }
665
666 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
667                               unsigned long count, loff_t pos)
668 {
669         struct file *file = iocb->ki_filp;
670         struct tun_struct *tun = tun_get(file);
671         ssize_t result;
672
673         if (!tun)
674                 return -EBADFD;
675
676         DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);
677
678         result = tun_get_user(tun, iv, iov_length(iv, count),
679                               file->f_flags & O_NONBLOCK);
680
681         tun_put(tun);
682         return result;
683 }
684
685 /* Put packet to the user space buffer */
686 static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
687                                        struct sk_buff *skb,
688                                        const struct iovec *iv, int len)
689 {
690         struct tun_pi pi = { 0, skb->protocol };
691         ssize_t total = 0;
692
693         if (!(tun->flags & TUN_NO_PI)) {
694                 if ((len -= sizeof(pi)) < 0)
695                         return -EINVAL;
696
697                 if (len < skb->len) {
698                         /* Packet will be striped */
699                         pi.flags |= TUN_PKT_STRIP;
700                 }
701
702                 if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi)))
703                         return -EFAULT;
704                 total += sizeof(pi);
705         }
706
707         if (tun->flags & TUN_VNET_HDR) {
708                 struct virtio_net_hdr gso = { 0 }; /* no info leak */
709                 if ((len -= sizeof(gso)) < 0)
710                         return -EINVAL;
711
712                 if (skb_is_gso(skb)) {
713                         struct skb_shared_info *sinfo = skb_shinfo(skb);
714
715                         /* This is a hint as to how much should be linear. */
716                         gso.hdr_len = skb_headlen(skb);
717                         gso.gso_size = sinfo->gso_size;
718                         if (sinfo->gso_type & SKB_GSO_TCPV4)
719                                 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
720                         else if (sinfo->gso_type & SKB_GSO_TCPV6)
721                                 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
722                         else if (sinfo->gso_type & SKB_GSO_UDP)
723                                 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
724                         else
725                                 BUG();
726                         if (sinfo->gso_type & SKB_GSO_TCP_ECN)
727                                 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
728                 } else
729                         gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
730
731                 if (skb->ip_summed == CHECKSUM_PARTIAL) {
732                         gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
733                         gso.csum_start = skb->csum_start - skb_headroom(skb);
734                         gso.csum_offset = skb->csum_offset;
735                 } /* else everything is zero */
736
737                 if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
738                                                sizeof(gso))))
739                         return -EFAULT;
740                 total += sizeof(gso);
741         }
742
743         len = min_t(int, skb->len, len);
744
745         skb_copy_datagram_const_iovec(skb, 0, iv, total, len);
746         total += len;
747
748         tun->dev->stats.tx_packets++;
749         tun->dev->stats.tx_bytes += len;
750
751         return total;
752 }
753
754 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
755                             unsigned long count, loff_t pos)
756 {
757         struct file *file = iocb->ki_filp;
758         struct tun_file *tfile = file->private_data;
759         struct tun_struct *tun = __tun_get(tfile);
760         DECLARE_WAITQUEUE(wait, current);
761         struct sk_buff *skb;
762         ssize_t len, ret = 0;
763
764         if (!tun)
765                 return -EBADFD;
766
767         DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
768
769         len = iov_length(iv, count);
770         if (len < 0) {
771                 ret = -EINVAL;
772                 goto out;
773         }
774
775         add_wait_queue(&tun->socket.wait, &wait);
776         while (len) {
777                 current->state = TASK_INTERRUPTIBLE;
778
779                 /* Read frames from the queue */
780                 if (!(skb=skb_dequeue(&tun->socket.sk->sk_receive_queue))) {
781                         if (file->f_flags & O_NONBLOCK) {
782                                 ret = -EAGAIN;
783                                 break;
784                         }
785                         if (signal_pending(current)) {
786                                 ret = -ERESTARTSYS;
787                                 break;
788                         }
789                         if (tun->dev->reg_state != NETREG_REGISTERED) {
790                                 ret = -EIO;
791                                 break;
792                         }
793
794                         /* Nothing to read, let's sleep */
795                         schedule();
796                         continue;
797                 }
798                 netif_wake_queue(tun->dev);
799
800                 ret = tun_put_user(tun, skb, iv, len);
801                 kfree_skb(skb);
802                 break;
803         }
804
805         current->state = TASK_RUNNING;
806         remove_wait_queue(&tun->socket.wait, &wait);
807
808 out:
809         tun_put(tun);
810         return ret;
811 }
812
813 static void tun_setup(struct net_device *dev)
814 {
815         struct tun_struct *tun = netdev_priv(dev);
816
817         tun->owner = -1;
818         tun->group = -1;
819
820         dev->ethtool_ops = &tun_ethtool_ops;
821         dev->destructor = tun_free_netdev;
822 }
823
824 /* Trivial set of netlink ops to allow deleting tun or tap
825  * device with netlink.
826  */
827 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
828 {
829         return -EINVAL;
830 }
831
832 static struct rtnl_link_ops tun_link_ops __read_mostly = {
833         .kind           = DRV_NAME,
834         .priv_size      = sizeof(struct tun_struct),
835         .setup          = tun_setup,
836         .validate       = tun_validate,
837 };
838
839 static void tun_sock_write_space(struct sock *sk)
840 {
841         struct tun_struct *tun;
842
843         if (!sock_writeable(sk))
844                 return;
845
846         if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
847                 return;
848
849         if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
850                 wake_up_interruptible_sync(sk->sk_sleep);
851
852         tun = container_of(sk, struct tun_sock, sk)->tun;
853         kill_fasync(&tun->fasync, SIGIO, POLL_OUT);
854 }
855
856 static void tun_sock_destruct(struct sock *sk)
857 {
858         free_netdev(container_of(sk, struct tun_sock, sk)->tun->dev);
859 }
860
861 static struct proto tun_proto = {
862         .name           = "tun",
863         .owner          = THIS_MODULE,
864         .obj_size       = sizeof(struct tun_sock),
865 };
866
867 static int tun_flags(struct tun_struct *tun)
868 {
869         int flags = 0;
870
871         if (tun->flags & TUN_TUN_DEV)
872                 flags |= IFF_TUN;
873         else
874                 flags |= IFF_TAP;
875
876         if (tun->flags & TUN_NO_PI)
877                 flags |= IFF_NO_PI;
878
879         if (tun->flags & TUN_ONE_QUEUE)
880                 flags |= IFF_ONE_QUEUE;
881
882         if (tun->flags & TUN_VNET_HDR)
883                 flags |= IFF_VNET_HDR;
884
885         return flags;
886 }
887
888 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
889                               char *buf)
890 {
891         struct tun_struct *tun = netdev_priv(to_net_dev(dev));
892         return sprintf(buf, "0x%x\n", tun_flags(tun));
893 }
894
895 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
896                               char *buf)
897 {
898         struct tun_struct *tun = netdev_priv(to_net_dev(dev));
899         return sprintf(buf, "%d\n", tun->owner);
900 }
901
902 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
903                               char *buf)
904 {
905         struct tun_struct *tun = netdev_priv(to_net_dev(dev));
906         return sprintf(buf, "%d\n", tun->group);
907 }
908
909 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
910 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
911 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
912
913 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
914 {
915         struct sock *sk;
916         struct tun_struct *tun;
917         struct net_device *dev;
918         int err;
919
920         dev = __dev_get_by_name(net, ifr->ifr_name);
921         if (dev) {
922                 const struct cred *cred = current_cred();
923
924                 if (ifr->ifr_flags & IFF_TUN_EXCL)
925                         return -EBUSY;
926                 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
927                         tun = netdev_priv(dev);
928                 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
929                         tun = netdev_priv(dev);
930                 else
931                         return -EINVAL;
932
933                 if (((tun->owner != -1 && cred->euid != tun->owner) ||
934                      (tun->group != -1 && !in_egroup_p(tun->group))) &&
935                     !capable(CAP_NET_ADMIN))
936                         return -EPERM;
937                 err = security_tun_dev_attach(tun->socket.sk);
938                 if (err < 0)
939                         return err;
940
941                 err = tun_attach(tun, file);
942                 if (err < 0)
943                         return err;
944         }
945         else {
946                 char *name;
947                 unsigned long flags = 0;
948
949                 if (!capable(CAP_NET_ADMIN))
950                         return -EPERM;
951                 err = security_tun_dev_create();
952                 if (err < 0)
953                         return err;
954
955                 /* Set dev type */
956                 if (ifr->ifr_flags & IFF_TUN) {
957                         /* TUN device */
958                         flags |= TUN_TUN_DEV;
959                         name = "tun%d";
960                 } else if (ifr->ifr_flags & IFF_TAP) {
961                         /* TAP device */
962                         flags |= TUN_TAP_DEV;
963                         name = "tap%d";
964                 } else
965                         return -EINVAL;
966
967                 if (*ifr->ifr_name)
968                         name = ifr->ifr_name;
969
970                 dev = alloc_netdev(sizeof(struct tun_struct), name,
971                                    tun_setup);
972                 if (!dev)
973                         return -ENOMEM;
974
975                 dev_net_set(dev, net);
976                 dev->rtnl_link_ops = &tun_link_ops;
977
978                 tun = netdev_priv(dev);
979                 tun->dev = dev;
980                 tun->flags = flags;
981                 tun->txflt.count = 0;
982
983                 err = -ENOMEM;
984                 sk = sk_alloc(net, AF_UNSPEC, GFP_KERNEL, &tun_proto);
985                 if (!sk)
986                         goto err_free_dev;
987
988                 init_waitqueue_head(&tun->socket.wait);
989                 sock_init_data(&tun->socket, sk);
990                 sk->sk_write_space = tun_sock_write_space;
991                 sk->sk_sndbuf = INT_MAX;
992
993                 container_of(sk, struct tun_sock, sk)->tun = tun;
994
995                 security_tun_dev_post_create(sk);
996
997                 tun_net_init(dev);
998
999                 if (strchr(dev->name, '%')) {
1000                         err = dev_alloc_name(dev, dev->name);
1001                         if (err < 0)
1002                                 goto err_free_sk;
1003                 }
1004
1005                 err = register_netdevice(tun->dev);
1006                 if (err < 0)
1007                         goto err_free_sk;
1008
1009                 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
1010                     device_create_file(&tun->dev->dev, &dev_attr_owner) ||
1011                     device_create_file(&tun->dev->dev, &dev_attr_group))
1012                         printk(KERN_ERR "Failed to create tun sysfs files\n");
1013
1014                 sk->sk_destruct = tun_sock_destruct;
1015
1016                 err = tun_attach(tun, file);
1017                 if (err < 0)
1018                         goto failed;
1019         }
1020
1021         DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);
1022
1023         if (ifr->ifr_flags & IFF_NO_PI)
1024                 tun->flags |= TUN_NO_PI;
1025         else
1026                 tun->flags &= ~TUN_NO_PI;
1027
1028         if (ifr->ifr_flags & IFF_ONE_QUEUE)
1029                 tun->flags |= TUN_ONE_QUEUE;
1030         else
1031                 tun->flags &= ~TUN_ONE_QUEUE;
1032
1033         if (ifr->ifr_flags & IFF_VNET_HDR)
1034                 tun->flags |= TUN_VNET_HDR;
1035         else
1036                 tun->flags &= ~TUN_VNET_HDR;
1037
1038         /* Make sure persistent devices do not get stuck in
1039          * xoff state.
1040          */
1041         if (netif_running(tun->dev))
1042                 netif_wake_queue(tun->dev);
1043
1044         strcpy(ifr->ifr_name, tun->dev->name);
1045         return 0;
1046
1047  err_free_sk:
1048         sock_put(sk);
1049  err_free_dev:
1050         free_netdev(dev);
1051  failed:
1052         return err;
1053 }
1054
1055 static int tun_get_iff(struct net *net, struct tun_struct *tun,
1056                        struct ifreq *ifr)
1057 {
1058         DBG(KERN_INFO "%s: tun_get_iff\n", tun->dev->name);
1059
1060         strcpy(ifr->ifr_name, tun->dev->name);
1061
1062         ifr->ifr_flags = tun_flags(tun);
1063
1064         return 0;
1065 }
1066
1067 /* This is like a cut-down ethtool ops, except done via tun fd so no
1068  * privs required. */
1069 static int set_offload(struct net_device *dev, unsigned long arg)
1070 {
1071         unsigned int old_features, features;
1072
1073         old_features = dev->features;
1074         /* Unset features, set them as we chew on the arg. */
1075         features = (old_features & ~(NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST
1076                                     |NETIF_F_TSO_ECN|NETIF_F_TSO|NETIF_F_TSO6
1077                                     |NETIF_F_UFO));
1078
1079         if (arg & TUN_F_CSUM) {
1080                 features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1081                 arg &= ~TUN_F_CSUM;
1082
1083                 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1084                         if (arg & TUN_F_TSO_ECN) {
1085                                 features |= NETIF_F_TSO_ECN;
1086                                 arg &= ~TUN_F_TSO_ECN;
1087                         }
1088                         if (arg & TUN_F_TSO4)
1089                                 features |= NETIF_F_TSO;
1090                         if (arg & TUN_F_TSO6)
1091                                 features |= NETIF_F_TSO6;
1092                         arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1093                 }
1094
1095                 if (arg & TUN_F_UFO) {
1096                         features |= NETIF_F_UFO;
1097                         arg &= ~TUN_F_UFO;
1098                 }
1099         }
1100
1101         /* This gives the user a way to test for new features in future by
1102          * trying to set them. */
1103         if (arg)
1104                 return -EINVAL;
1105
1106         dev->features = features;
1107         if (old_features != dev->features)
1108                 netdev_features_change(dev);
1109
1110         return 0;
1111 }
1112
1113 static long tun_chr_ioctl(struct file *file, unsigned int cmd,
1114                           unsigned long arg)
1115 {
1116         struct tun_file *tfile = file->private_data;
1117         struct tun_struct *tun;
1118         void __user* argp = (void __user*)arg;
1119         struct ifreq ifr;
1120         int sndbuf;
1121         int ret;
1122
1123         if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
1124                 if (copy_from_user(&ifr, argp, sizeof ifr))
1125                         return -EFAULT;
1126
1127         if (cmd == TUNGETFEATURES) {
1128                 /* Currently this just means: "what IFF flags are valid?".
1129                  * This is needed because we never checked for invalid flags on
1130                  * TUNSETIFF. */
1131                 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
1132                                 IFF_VNET_HDR,
1133                                 (unsigned int __user*)argp);
1134         }
1135
1136         rtnl_lock();
1137
1138         tun = __tun_get(tfile);
1139         if (cmd == TUNSETIFF && !tun) {
1140                 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1141
1142                 ret = tun_set_iff(tfile->net, file, &ifr);
1143
1144                 if (ret)
1145                         goto unlock;
1146
1147                 if (copy_to_user(argp, &ifr, sizeof(ifr)))
1148                         ret = -EFAULT;
1149                 goto unlock;
1150         }
1151
1152         ret = -EBADFD;
1153         if (!tun)
1154                 goto unlock;
1155
1156         DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd);
1157
1158         ret = 0;
1159         switch (cmd) {
1160         case TUNGETIFF:
1161                 ret = tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1162                 if (ret)
1163                         break;
1164
1165                 if (copy_to_user(argp, &ifr, sizeof(ifr)))
1166                         ret = -EFAULT;
1167                 break;
1168
1169         case TUNSETNOCSUM:
1170                 /* Disable/Enable checksum */
1171                 if (arg)
1172                         tun->flags |= TUN_NOCHECKSUM;
1173                 else
1174                         tun->flags &= ~TUN_NOCHECKSUM;
1175
1176                 DBG(KERN_INFO "%s: checksum %s\n",
1177                     tun->dev->name, arg ? "disabled" : "enabled");
1178                 break;
1179
1180         case TUNSETPERSIST:
1181                 /* Disable/Enable persist mode */
1182                 if (arg)
1183                         tun->flags |= TUN_PERSIST;
1184                 else
1185                         tun->flags &= ~TUN_PERSIST;
1186
1187                 DBG(KERN_INFO "%s: persist %s\n",
1188                     tun->dev->name, arg ? "enabled" : "disabled");
1189                 break;
1190
1191         case TUNSETOWNER:
1192                 /* Set owner of the device */
1193                 tun->owner = (uid_t) arg;
1194
1195                 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner);
1196                 break;
1197
1198         case TUNSETGROUP:
1199                 /* Set group of the device */
1200                 tun->group= (gid_t) arg;
1201
1202                 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group);
1203                 break;
1204
1205         case TUNSETLINK:
1206                 /* Only allow setting the type when the interface is down */
1207                 if (tun->dev->flags & IFF_UP) {
1208                         DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
1209                                 tun->dev->name);
1210                         ret = -EBUSY;
1211                 } else {
1212                         tun->dev->type = (int) arg;
1213                         DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
1214                         ret = 0;
1215                 }
1216                 break;
1217
1218 #ifdef TUN_DEBUG
1219         case TUNSETDEBUG:
1220                 tun->debug = arg;
1221                 break;
1222 #endif
1223         case TUNSETOFFLOAD:
1224                 ret = set_offload(tun->dev, arg);
1225                 break;
1226
1227         case TUNSETTXFILTER:
1228                 /* Can be set only for TAPs */
1229                 ret = -EINVAL;
1230                 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1231                         break;
1232                 ret = update_filter(&tun->txflt, (void __user *)arg);
1233                 break;
1234
1235         case SIOCGIFHWADDR:
1236                 /* Get hw addres */
1237                 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
1238                 ifr.ifr_hwaddr.sa_family = tun->dev->type;
1239                 if (copy_to_user(argp, &ifr, sizeof ifr))
1240                         ret = -EFAULT;
1241                 break;
1242
1243         case SIOCSIFHWADDR:
1244                 /* Set hw address */
1245                 DBG(KERN_DEBUG "%s: set hw address: %pM\n",
1246                         tun->dev->name, ifr.ifr_hwaddr.sa_data);
1247
1248                 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
1249                 break;
1250
1251         case TUNGETSNDBUF:
1252                 sndbuf = tun->socket.sk->sk_sndbuf;
1253                 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
1254                         ret = -EFAULT;
1255                 break;
1256
1257         case TUNSETSNDBUF:
1258                 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
1259                         ret = -EFAULT;
1260                         break;
1261                 }
1262
1263                 tun->socket.sk->sk_sndbuf = sndbuf;
1264                 break;
1265
1266         default:
1267                 ret = -EINVAL;
1268                 break;
1269         };
1270
1271 unlock:
1272         rtnl_unlock();
1273         if (tun)
1274                 tun_put(tun);
1275         return ret;
1276 }
1277
1278 static int tun_chr_fasync(int fd, struct file *file, int on)
1279 {
1280         struct tun_struct *tun = tun_get(file);
1281         int ret;
1282
1283         if (!tun)
1284                 return -EBADFD;
1285
1286         DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);
1287
1288         lock_kernel();
1289         if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
1290                 goto out;
1291
1292         if (on) {
1293                 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
1294                 if (ret)
1295                         goto out;
1296                 tun->flags |= TUN_FASYNC;
1297         } else
1298                 tun->flags &= ~TUN_FASYNC;
1299         ret = 0;
1300 out:
1301         unlock_kernel();
1302         tun_put(tun);
1303         return ret;
1304 }
1305
1306 static int tun_chr_open(struct inode *inode, struct file * file)
1307 {
1308         struct tun_file *tfile;
1309         cycle_kernel_lock();
1310         DBG1(KERN_INFO "tunX: tun_chr_open\n");
1311
1312         tfile = kmalloc(sizeof(*tfile), GFP_KERNEL);
1313         if (!tfile)
1314                 return -ENOMEM;
1315         atomic_set(&tfile->count, 0);
1316         tfile->tun = NULL;
1317         tfile->net = get_net(current->nsproxy->net_ns);
1318         file->private_data = tfile;
1319         return 0;
1320 }
1321
1322 static int tun_chr_close(struct inode *inode, struct file *file)
1323 {
1324         struct tun_file *tfile = file->private_data;
1325         struct tun_struct *tun;
1326
1327         tun = __tun_get(tfile);
1328         if (tun) {
1329                 struct net_device *dev = tun->dev;
1330
1331                 DBG(KERN_INFO "%s: tun_chr_close\n", dev->name);
1332
1333                 __tun_detach(tun);
1334
1335                 /* If desireable, unregister the netdevice. */
1336                 if (!(tun->flags & TUN_PERSIST)) {
1337                         rtnl_lock();
1338                         if (dev->reg_state == NETREG_REGISTERED)
1339                                 unregister_netdevice(dev);
1340                         rtnl_unlock();
1341                 }
1342         }
1343
1344         tun = tfile->tun;
1345         if (tun)
1346                 sock_put(tun->socket.sk);
1347
1348         put_net(tfile->net);
1349         kfree(tfile);
1350
1351         return 0;
1352 }
1353
1354 static const struct file_operations tun_fops = {
1355         .owner  = THIS_MODULE,
1356         .llseek = no_llseek,
1357         .read  = do_sync_read,
1358         .aio_read  = tun_chr_aio_read,
1359         .write = do_sync_write,
1360         .aio_write = tun_chr_aio_write,
1361         .poll   = tun_chr_poll,
1362         .unlocked_ioctl = tun_chr_ioctl,
1363         .open   = tun_chr_open,
1364         .release = tun_chr_close,
1365         .fasync = tun_chr_fasync
1366 };
1367
1368 static struct miscdevice tun_miscdev = {
1369         .minor = TUN_MINOR,
1370         .name = "tun",
1371         .nodename = "net/tun",
1372         .fops = &tun_fops,
1373 };
1374
1375 /* ethtool interface */
1376
1377 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1378 {
1379         cmd->supported          = 0;
1380         cmd->advertising        = 0;
1381         cmd->speed              = SPEED_10;
1382         cmd->duplex             = DUPLEX_FULL;
1383         cmd->port               = PORT_TP;
1384         cmd->phy_address        = 0;
1385         cmd->transceiver        = XCVR_INTERNAL;
1386         cmd->autoneg            = AUTONEG_DISABLE;
1387         cmd->maxtxpkt           = 0;
1388         cmd->maxrxpkt           = 0;
1389         return 0;
1390 }
1391
1392 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
1393 {
1394         struct tun_struct *tun = netdev_priv(dev);
1395
1396         strcpy(info->driver, DRV_NAME);
1397         strcpy(info->version, DRV_VERSION);
1398         strcpy(info->fw_version, "N/A");
1399
1400         switch (tun->flags & TUN_TYPE_MASK) {
1401         case TUN_TUN_DEV:
1402                 strcpy(info->bus_info, "tun");
1403                 break;
1404         case TUN_TAP_DEV:
1405                 strcpy(info->bus_info, "tap");
1406                 break;
1407         }
1408 }
1409
1410 static u32 tun_get_msglevel(struct net_device *dev)
1411 {
1412 #ifdef TUN_DEBUG
1413         struct tun_struct *tun = netdev_priv(dev);
1414         return tun->debug;
1415 #else
1416         return -EOPNOTSUPP;
1417 #endif
1418 }
1419
1420 static void tun_set_msglevel(struct net_device *dev, u32 value)
1421 {
1422 #ifdef TUN_DEBUG
1423         struct tun_struct *tun = netdev_priv(dev);
1424         tun->debug = value;
1425 #endif
1426 }
1427
1428 static u32 tun_get_link(struct net_device *dev)
1429 {
1430         struct tun_struct *tun = netdev_priv(dev);
1431         return !!tun->tfile;
1432 }
1433
1434 static u32 tun_get_rx_csum(struct net_device *dev)
1435 {
1436         struct tun_struct *tun = netdev_priv(dev);
1437         return (tun->flags & TUN_NOCHECKSUM) == 0;
1438 }
1439
1440 static int tun_set_rx_csum(struct net_device *dev, u32 data)
1441 {
1442         struct tun_struct *tun = netdev_priv(dev);
1443         if (data)
1444                 tun->flags &= ~TUN_NOCHECKSUM;
1445         else
1446                 tun->flags |= TUN_NOCHECKSUM;
1447         return 0;
1448 }
1449
1450 static const struct ethtool_ops tun_ethtool_ops = {
1451         .get_settings   = tun_get_settings,
1452         .get_drvinfo    = tun_get_drvinfo,
1453         .get_msglevel   = tun_get_msglevel,
1454         .set_msglevel   = tun_set_msglevel,
1455         .get_link       = tun_get_link,
1456         .get_rx_csum    = tun_get_rx_csum,
1457         .set_rx_csum    = tun_set_rx_csum
1458 };
1459
1460
1461 static int __init tun_init(void)
1462 {
1463         int ret = 0;
1464
1465         printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
1466         printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);
1467
1468         ret = rtnl_link_register(&tun_link_ops);
1469         if (ret) {
1470                 printk(KERN_ERR "tun: Can't register link_ops\n");
1471                 goto err_linkops;
1472         }
1473
1474         ret = misc_register(&tun_miscdev);
1475         if (ret) {
1476                 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
1477                 goto err_misc;
1478         }
1479         return  0;
1480 err_misc:
1481         rtnl_link_unregister(&tun_link_ops);
1482 err_linkops:
1483         return ret;
1484 }
1485
1486 static void tun_cleanup(void)
1487 {
1488         misc_deregister(&tun_miscdev);
1489         rtnl_link_unregister(&tun_link_ops);
1490 }
1491
1492 module_init(tun_init);
1493 module_exit(tun_cleanup);
1494 MODULE_DESCRIPTION(DRV_DESCRIPTION);
1495 MODULE_AUTHOR(DRV_COPYRIGHT);
1496 MODULE_LICENSE("GPL");
1497 MODULE_ALIAS_MISCDEV(TUN_MINOR);