]> git.karo-electronics.de Git - karo-tx-linux.git/blob - drivers/net/tun.c
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi...
[karo-tx-linux.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 pr_fmt(fmt) KBUILD_MODNAME ": " fmt
38
39 #define DRV_NAME        "tun"
40 #define DRV_VERSION     "1.6"
41 #define DRV_DESCRIPTION "Universal TUN/TAP device driver"
42 #define DRV_COPYRIGHT   "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>"
43
44 #include <linux/module.h>
45 #include <linux/errno.h>
46 #include <linux/kernel.h>
47 #include <linux/major.h>
48 #include <linux/slab.h>
49 #include <linux/poll.h>
50 #include <linux/fcntl.h>
51 #include <linux/init.h>
52 #include <linux/skbuff.h>
53 #include <linux/netdevice.h>
54 #include <linux/etherdevice.h>
55 #include <linux/miscdevice.h>
56 #include <linux/ethtool.h>
57 #include <linux/rtnetlink.h>
58 #include <linux/compat.h>
59 #include <linux/if.h>
60 #include <linux/if_arp.h>
61 #include <linux/if_ether.h>
62 #include <linux/if_tun.h>
63 #include <linux/crc32.h>
64 #include <linux/nsproxy.h>
65 #include <linux/virtio_net.h>
66 #include <linux/rcupdate.h>
67 #include <net/net_namespace.h>
68 #include <net/netns/generic.h>
69 #include <net/rtnetlink.h>
70 #include <net/sock.h>
71
72 #include <asm/uaccess.h>
73
74 /* Uncomment to enable debugging */
75 /* #define TUN_DEBUG 1 */
76
77 #ifdef TUN_DEBUG
78 static int debug;
79
80 #define tun_debug(level, tun, fmt, args...)                     \
81 do {                                                            \
82         if (tun->debug)                                         \
83                 netdev_printk(level, tun->dev, fmt, ##args);    \
84 } while (0)
85 #define DBG1(level, fmt, args...)                               \
86 do {                                                            \
87         if (debug == 2)                                         \
88                 printk(level fmt, ##args);                      \
89 } while (0)
90 #else
91 #define tun_debug(level, tun, fmt, args...)                     \
92 do {                                                            \
93         if (0)                                                  \
94                 netdev_printk(level, tun->dev, fmt, ##args);    \
95 } while (0)
96 #define DBG1(level, fmt, args...)                               \
97 do {                                                            \
98         if (0)                                                  \
99                 printk(level fmt, ##args);                      \
100 } while (0)
101 #endif
102
103 #define FLT_EXACT_COUNT 8
104 struct tap_filter {
105         unsigned int    count;    /* Number of addrs. Zero means disabled */
106         u32             mask[2];  /* Mask of the hashed addrs */
107         unsigned char   addr[FLT_EXACT_COUNT][ETH_ALEN];
108 };
109
110 struct tun_file {
111         atomic_t count;
112         struct tun_struct *tun;
113         struct net *net;
114 };
115
116 struct tun_sock;
117
118 struct tun_struct {
119         struct tun_file         *tfile;
120         unsigned int            flags;
121         uid_t                   owner;
122         gid_t                   group;
123
124         struct net_device       *dev;
125         netdev_features_t       set_features;
126 #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \
127                           NETIF_F_TSO6|NETIF_F_UFO)
128         struct fasync_struct    *fasync;
129
130         struct tap_filter       txflt;
131         struct socket           socket;
132         struct socket_wq        wq;
133
134         int                     vnet_hdr_sz;
135
136 #ifdef TUN_DEBUG
137         int debug;
138 #endif
139 };
140
141 struct tun_sock {
142         struct sock             sk;
143         struct tun_struct       *tun;
144 };
145
146 static inline struct tun_sock *tun_sk(struct sock *sk)
147 {
148         return container_of(sk, struct tun_sock, sk);
149 }
150
151 static int tun_attach(struct tun_struct *tun, struct file *file)
152 {
153         struct tun_file *tfile = file->private_data;
154         int err;
155
156         ASSERT_RTNL();
157
158         netif_tx_lock_bh(tun->dev);
159
160         err = -EINVAL;
161         if (tfile->tun)
162                 goto out;
163
164         err = -EBUSY;
165         if (tun->tfile)
166                 goto out;
167
168         err = 0;
169         tfile->tun = tun;
170         tun->tfile = tfile;
171         tun->socket.file = file;
172         netif_carrier_on(tun->dev);
173         dev_hold(tun->dev);
174         sock_hold(tun->socket.sk);
175         atomic_inc(&tfile->count);
176
177 out:
178         netif_tx_unlock_bh(tun->dev);
179         return err;
180 }
181
182 static void __tun_detach(struct tun_struct *tun)
183 {
184         /* Detach from net device */
185         netif_tx_lock_bh(tun->dev);
186         netif_carrier_off(tun->dev);
187         tun->tfile = NULL;
188         tun->socket.file = NULL;
189         netif_tx_unlock_bh(tun->dev);
190
191         /* Drop read queue */
192         skb_queue_purge(&tun->socket.sk->sk_receive_queue);
193
194         /* Drop the extra count on the net device */
195         dev_put(tun->dev);
196 }
197
198 static void tun_detach(struct tun_struct *tun)
199 {
200         rtnl_lock();
201         __tun_detach(tun);
202         rtnl_unlock();
203 }
204
205 static struct tun_struct *__tun_get(struct tun_file *tfile)
206 {
207         struct tun_struct *tun = NULL;
208
209         if (atomic_inc_not_zero(&tfile->count))
210                 tun = tfile->tun;
211
212         return tun;
213 }
214
215 static struct tun_struct *tun_get(struct file *file)
216 {
217         return __tun_get(file->private_data);
218 }
219
220 static void tun_put(struct tun_struct *tun)
221 {
222         struct tun_file *tfile = tun->tfile;
223
224         if (atomic_dec_and_test(&tfile->count))
225                 tun_detach(tfile->tun);
226 }
227
228 /* TAP filtering */
229 static void addr_hash_set(u32 *mask, const u8 *addr)
230 {
231         int n = ether_crc(ETH_ALEN, addr) >> 26;
232         mask[n >> 5] |= (1 << (n & 31));
233 }
234
235 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
236 {
237         int n = ether_crc(ETH_ALEN, addr) >> 26;
238         return mask[n >> 5] & (1 << (n & 31));
239 }
240
241 static int update_filter(struct tap_filter *filter, void __user *arg)
242 {
243         struct { u8 u[ETH_ALEN]; } *addr;
244         struct tun_filter uf;
245         int err, alen, n, nexact;
246
247         if (copy_from_user(&uf, arg, sizeof(uf)))
248                 return -EFAULT;
249
250         if (!uf.count) {
251                 /* Disabled */
252                 filter->count = 0;
253                 return 0;
254         }
255
256         alen = ETH_ALEN * uf.count;
257         addr = kmalloc(alen, GFP_KERNEL);
258         if (!addr)
259                 return -ENOMEM;
260
261         if (copy_from_user(addr, arg + sizeof(uf), alen)) {
262                 err = -EFAULT;
263                 goto done;
264         }
265
266         /* The filter is updated without holding any locks. Which is
267          * perfectly safe. We disable it first and in the worst
268          * case we'll accept a few undesired packets. */
269         filter->count = 0;
270         wmb();
271
272         /* Use first set of addresses as an exact filter */
273         for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
274                 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
275
276         nexact = n;
277
278         /* Remaining multicast addresses are hashed,
279          * unicast will leave the filter disabled. */
280         memset(filter->mask, 0, sizeof(filter->mask));
281         for (; n < uf.count; n++) {
282                 if (!is_multicast_ether_addr(addr[n].u)) {
283                         err = 0; /* no filter */
284                         goto done;
285                 }
286                 addr_hash_set(filter->mask, addr[n].u);
287         }
288
289         /* For ALLMULTI just set the mask to all ones.
290          * This overrides the mask populated above. */
291         if ((uf.flags & TUN_FLT_ALLMULTI))
292                 memset(filter->mask, ~0, sizeof(filter->mask));
293
294         /* Now enable the filter */
295         wmb();
296         filter->count = nexact;
297
298         /* Return the number of exact filters */
299         err = nexact;
300
301 done:
302         kfree(addr);
303         return err;
304 }
305
306 /* Returns: 0 - drop, !=0 - accept */
307 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
308 {
309         /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
310          * at this point. */
311         struct ethhdr *eh = (struct ethhdr *) skb->data;
312         int i;
313
314         /* Exact match */
315         for (i = 0; i < filter->count; i++)
316                 if (ether_addr_equal(eh->h_dest, filter->addr[i]))
317                         return 1;
318
319         /* Inexact match (multicast only) */
320         if (is_multicast_ether_addr(eh->h_dest))
321                 return addr_hash_test(filter->mask, eh->h_dest);
322
323         return 0;
324 }
325
326 /*
327  * Checks whether the packet is accepted or not.
328  * Returns: 0 - drop, !=0 - accept
329  */
330 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
331 {
332         if (!filter->count)
333                 return 1;
334
335         return run_filter(filter, skb);
336 }
337
338 /* Network device part of the driver */
339
340 static const struct ethtool_ops tun_ethtool_ops;
341
342 /* Net device detach from fd. */
343 static void tun_net_uninit(struct net_device *dev)
344 {
345         struct tun_struct *tun = netdev_priv(dev);
346         struct tun_file *tfile = tun->tfile;
347
348         /* Inform the methods they need to stop using the dev.
349          */
350         if (tfile) {
351                 wake_up_all(&tun->wq.wait);
352                 if (atomic_dec_and_test(&tfile->count))
353                         __tun_detach(tun);
354         }
355 }
356
357 static void tun_free_netdev(struct net_device *dev)
358 {
359         struct tun_struct *tun = netdev_priv(dev);
360
361         sk_release_kernel(tun->socket.sk);
362 }
363
364 /* Net device open. */
365 static int tun_net_open(struct net_device *dev)
366 {
367         netif_start_queue(dev);
368         return 0;
369 }
370
371 /* Net device close. */
372 static int tun_net_close(struct net_device *dev)
373 {
374         netif_stop_queue(dev);
375         return 0;
376 }
377
378 /* Net device start xmit */
379 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
380 {
381         struct tun_struct *tun = netdev_priv(dev);
382
383         tun_debug(KERN_INFO, tun, "tun_net_xmit %d\n", skb->len);
384
385         /* Drop packet if interface is not attached */
386         if (!tun->tfile)
387                 goto drop;
388
389         /* Drop if the filter does not like it.
390          * This is a noop if the filter is disabled.
391          * Filter can be enabled only for the TAP devices. */
392         if (!check_filter(&tun->txflt, skb))
393                 goto drop;
394
395         if (tun->socket.sk->sk_filter &&
396             sk_filter(tun->socket.sk, skb))
397                 goto drop;
398
399         if (skb_queue_len(&tun->socket.sk->sk_receive_queue) >= dev->tx_queue_len) {
400                 if (!(tun->flags & TUN_ONE_QUEUE)) {
401                         /* Normal queueing mode. */
402                         /* Packet scheduler handles dropping of further packets. */
403                         netif_stop_queue(dev);
404
405                         /* We won't see all dropped packets individually, so overrun
406                          * error is more appropriate. */
407                         dev->stats.tx_fifo_errors++;
408                 } else {
409                         /* Single queue mode.
410                          * Driver handles dropping of all packets itself. */
411                         goto drop;
412                 }
413         }
414
415         /* Orphan the skb - required as we might hang on to it
416          * for indefinite time. */
417         skb_orphan(skb);
418
419         /* Enqueue packet */
420         skb_queue_tail(&tun->socket.sk->sk_receive_queue, skb);
421
422         /* Notify and wake up reader process */
423         if (tun->flags & TUN_FASYNC)
424                 kill_fasync(&tun->fasync, SIGIO, POLL_IN);
425         wake_up_interruptible_poll(&tun->wq.wait, POLLIN |
426                                    POLLRDNORM | POLLRDBAND);
427         return NETDEV_TX_OK;
428
429 drop:
430         dev->stats.tx_dropped++;
431         kfree_skb(skb);
432         return NETDEV_TX_OK;
433 }
434
435 static void tun_net_mclist(struct net_device *dev)
436 {
437         /*
438          * This callback is supposed to deal with mc filter in
439          * _rx_ path and has nothing to do with the _tx_ path.
440          * In rx path we always accept everything userspace gives us.
441          */
442 }
443
444 #define MIN_MTU 68
445 #define MAX_MTU 65535
446
447 static int
448 tun_net_change_mtu(struct net_device *dev, int new_mtu)
449 {
450         if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
451                 return -EINVAL;
452         dev->mtu = new_mtu;
453         return 0;
454 }
455
456 static netdev_features_t tun_net_fix_features(struct net_device *dev,
457         netdev_features_t features)
458 {
459         struct tun_struct *tun = netdev_priv(dev);
460
461         return (features & tun->set_features) | (features & ~TUN_USER_FEATURES);
462 }
463 #ifdef CONFIG_NET_POLL_CONTROLLER
464 static void tun_poll_controller(struct net_device *dev)
465 {
466         /*
467          * Tun only receives frames when:
468          * 1) the char device endpoint gets data from user space
469          * 2) the tun socket gets a sendmsg call from user space
470          * Since both of those are syncronous operations, we are guaranteed
471          * never to have pending data when we poll for it
472          * so theres nothing to do here but return.
473          * We need this though so netpoll recognizes us as an interface that
474          * supports polling, which enables bridge devices in virt setups to
475          * still use netconsole
476          */
477         return;
478 }
479 #endif
480 static const struct net_device_ops tun_netdev_ops = {
481         .ndo_uninit             = tun_net_uninit,
482         .ndo_open               = tun_net_open,
483         .ndo_stop               = tun_net_close,
484         .ndo_start_xmit         = tun_net_xmit,
485         .ndo_change_mtu         = tun_net_change_mtu,
486         .ndo_fix_features       = tun_net_fix_features,
487 #ifdef CONFIG_NET_POLL_CONTROLLER
488         .ndo_poll_controller    = tun_poll_controller,
489 #endif
490 };
491
492 static const struct net_device_ops tap_netdev_ops = {
493         .ndo_uninit             = tun_net_uninit,
494         .ndo_open               = tun_net_open,
495         .ndo_stop               = tun_net_close,
496         .ndo_start_xmit         = tun_net_xmit,
497         .ndo_change_mtu         = tun_net_change_mtu,
498         .ndo_fix_features       = tun_net_fix_features,
499         .ndo_set_rx_mode        = tun_net_mclist,
500         .ndo_set_mac_address    = eth_mac_addr,
501         .ndo_validate_addr      = eth_validate_addr,
502 #ifdef CONFIG_NET_POLL_CONTROLLER
503         .ndo_poll_controller    = tun_poll_controller,
504 #endif
505 };
506
507 /* Initialize net device. */
508 static void tun_net_init(struct net_device *dev)
509 {
510         struct tun_struct *tun = netdev_priv(dev);
511
512         switch (tun->flags & TUN_TYPE_MASK) {
513         case TUN_TUN_DEV:
514                 dev->netdev_ops = &tun_netdev_ops;
515
516                 /* Point-to-Point TUN Device */
517                 dev->hard_header_len = 0;
518                 dev->addr_len = 0;
519                 dev->mtu = 1500;
520
521                 /* Zero header length */
522                 dev->type = ARPHRD_NONE;
523                 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
524                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
525                 break;
526
527         case TUN_TAP_DEV:
528                 dev->netdev_ops = &tap_netdev_ops;
529                 /* Ethernet TAP Device */
530                 ether_setup(dev);
531                 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
532
533                 eth_hw_addr_random(dev);
534
535                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
536                 break;
537         }
538 }
539
540 /* Character device part */
541
542 /* Poll */
543 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
544 {
545         struct tun_file *tfile = file->private_data;
546         struct tun_struct *tun = __tun_get(tfile);
547         struct sock *sk;
548         unsigned int mask = 0;
549
550         if (!tun)
551                 return POLLERR;
552
553         sk = tun->socket.sk;
554
555         tun_debug(KERN_INFO, tun, "tun_chr_poll\n");
556
557         poll_wait(file, &tun->wq.wait, wait);
558
559         if (!skb_queue_empty(&sk->sk_receive_queue))
560                 mask |= POLLIN | POLLRDNORM;
561
562         if (sock_writeable(sk) ||
563             (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
564              sock_writeable(sk)))
565                 mask |= POLLOUT | POLLWRNORM;
566
567         if (tun->dev->reg_state != NETREG_REGISTERED)
568                 mask = POLLERR;
569
570         tun_put(tun);
571         return mask;
572 }
573
574 /* prepad is the amount to reserve at front.  len is length after that.
575  * linear is a hint as to how much to copy (usually headers). */
576 static struct sk_buff *tun_alloc_skb(struct tun_struct *tun,
577                                      size_t prepad, size_t len,
578                                      size_t linear, int noblock)
579 {
580         struct sock *sk = tun->socket.sk;
581         struct sk_buff *skb;
582         int err;
583
584         sock_update_classid(sk);
585
586         /* Under a page?  Don't bother with paged skb. */
587         if (prepad + len < PAGE_SIZE || !linear)
588                 linear = len;
589
590         skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
591                                    &err);
592         if (!skb)
593                 return ERR_PTR(err);
594
595         skb_reserve(skb, prepad);
596         skb_put(skb, linear);
597         skb->data_len = len - linear;
598         skb->len += len - linear;
599
600         return skb;
601 }
602
603 /* Get packet from user space buffer */
604 static ssize_t tun_get_user(struct tun_struct *tun,
605                             const struct iovec *iv, size_t count,
606                             int noblock)
607 {
608         struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
609         struct sk_buff *skb;
610         size_t len = count, align = NET_SKB_PAD;
611         struct virtio_net_hdr gso = { 0 };
612         int offset = 0;
613
614         if (!(tun->flags & TUN_NO_PI)) {
615                 if ((len -= sizeof(pi)) > count)
616                         return -EINVAL;
617
618                 if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
619                         return -EFAULT;
620                 offset += sizeof(pi);
621         }
622
623         if (tun->flags & TUN_VNET_HDR) {
624                 if ((len -= tun->vnet_hdr_sz) > count)
625                         return -EINVAL;
626
627                 if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
628                         return -EFAULT;
629
630                 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
631                     gso.csum_start + gso.csum_offset + 2 > gso.hdr_len)
632                         gso.hdr_len = gso.csum_start + gso.csum_offset + 2;
633
634                 if (gso.hdr_len > len)
635                         return -EINVAL;
636                 offset += tun->vnet_hdr_sz;
637         }
638
639         if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
640                 align += NET_IP_ALIGN;
641                 if (unlikely(len < ETH_HLEN ||
642                              (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
643                         return -EINVAL;
644         }
645
646         skb = tun_alloc_skb(tun, align, len, gso.hdr_len, noblock);
647         if (IS_ERR(skb)) {
648                 if (PTR_ERR(skb) != -EAGAIN)
649                         tun->dev->stats.rx_dropped++;
650                 return PTR_ERR(skb);
651         }
652
653         if (skb_copy_datagram_from_iovec(skb, 0, iv, offset, len)) {
654                 tun->dev->stats.rx_dropped++;
655                 kfree_skb(skb);
656                 return -EFAULT;
657         }
658
659         if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
660                 if (!skb_partial_csum_set(skb, gso.csum_start,
661                                           gso.csum_offset)) {
662                         tun->dev->stats.rx_frame_errors++;
663                         kfree_skb(skb);
664                         return -EINVAL;
665                 }
666         }
667
668         switch (tun->flags & TUN_TYPE_MASK) {
669         case TUN_TUN_DEV:
670                 if (tun->flags & TUN_NO_PI) {
671                         switch (skb->data[0] & 0xf0) {
672                         case 0x40:
673                                 pi.proto = htons(ETH_P_IP);
674                                 break;
675                         case 0x60:
676                                 pi.proto = htons(ETH_P_IPV6);
677                                 break;
678                         default:
679                                 tun->dev->stats.rx_dropped++;
680                                 kfree_skb(skb);
681                                 return -EINVAL;
682                         }
683                 }
684
685                 skb_reset_mac_header(skb);
686                 skb->protocol = pi.proto;
687                 skb->dev = tun->dev;
688                 break;
689         case TUN_TAP_DEV:
690                 skb->protocol = eth_type_trans(skb, tun->dev);
691                 break;
692         }
693
694         if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
695                 pr_debug("GSO!\n");
696                 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
697                 case VIRTIO_NET_HDR_GSO_TCPV4:
698                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
699                         break;
700                 case VIRTIO_NET_HDR_GSO_TCPV6:
701                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
702                         break;
703                 case VIRTIO_NET_HDR_GSO_UDP:
704                         skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
705                         break;
706                 default:
707                         tun->dev->stats.rx_frame_errors++;
708                         kfree_skb(skb);
709                         return -EINVAL;
710                 }
711
712                 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
713                         skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
714
715                 skb_shinfo(skb)->gso_size = gso.gso_size;
716                 if (skb_shinfo(skb)->gso_size == 0) {
717                         tun->dev->stats.rx_frame_errors++;
718                         kfree_skb(skb);
719                         return -EINVAL;
720                 }
721
722                 /* Header must be checked, and gso_segs computed. */
723                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
724                 skb_shinfo(skb)->gso_segs = 0;
725         }
726
727         netif_rx_ni(skb);
728
729         tun->dev->stats.rx_packets++;
730         tun->dev->stats.rx_bytes += len;
731
732         return count;
733 }
734
735 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
736                               unsigned long count, loff_t pos)
737 {
738         struct file *file = iocb->ki_filp;
739         struct tun_struct *tun = tun_get(file);
740         ssize_t result;
741
742         if (!tun)
743                 return -EBADFD;
744
745         tun_debug(KERN_INFO, tun, "tun_chr_write %ld\n", count);
746
747         result = tun_get_user(tun, iv, iov_length(iv, count),
748                               file->f_flags & O_NONBLOCK);
749
750         tun_put(tun);
751         return result;
752 }
753
754 /* Put packet to the user space buffer */
755 static ssize_t tun_put_user(struct tun_struct *tun,
756                             struct sk_buff *skb,
757                             const struct iovec *iv, int len)
758 {
759         struct tun_pi pi = { 0, skb->protocol };
760         ssize_t total = 0;
761
762         if (!(tun->flags & TUN_NO_PI)) {
763                 if ((len -= sizeof(pi)) < 0)
764                         return -EINVAL;
765
766                 if (len < skb->len) {
767                         /* Packet will be striped */
768                         pi.flags |= TUN_PKT_STRIP;
769                 }
770
771                 if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi)))
772                         return -EFAULT;
773                 total += sizeof(pi);
774         }
775
776         if (tun->flags & TUN_VNET_HDR) {
777                 struct virtio_net_hdr gso = { 0 }; /* no info leak */
778                 if ((len -= tun->vnet_hdr_sz) < 0)
779                         return -EINVAL;
780
781                 if (skb_is_gso(skb)) {
782                         struct skb_shared_info *sinfo = skb_shinfo(skb);
783
784                         /* This is a hint as to how much should be linear. */
785                         gso.hdr_len = skb_headlen(skb);
786                         gso.gso_size = sinfo->gso_size;
787                         if (sinfo->gso_type & SKB_GSO_TCPV4)
788                                 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
789                         else if (sinfo->gso_type & SKB_GSO_TCPV6)
790                                 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
791                         else if (sinfo->gso_type & SKB_GSO_UDP)
792                                 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
793                         else {
794                                 pr_err("unexpected GSO type: "
795                                        "0x%x, gso_size %d, hdr_len %d\n",
796                                        sinfo->gso_type, gso.gso_size,
797                                        gso.hdr_len);
798                                 print_hex_dump(KERN_ERR, "tun: ",
799                                                DUMP_PREFIX_NONE,
800                                                16, 1, skb->head,
801                                                min((int)gso.hdr_len, 64), true);
802                                 WARN_ON_ONCE(1);
803                                 return -EINVAL;
804                         }
805                         if (sinfo->gso_type & SKB_GSO_TCP_ECN)
806                                 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
807                 } else
808                         gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
809
810                 if (skb->ip_summed == CHECKSUM_PARTIAL) {
811                         gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
812                         gso.csum_start = skb_checksum_start_offset(skb);
813                         gso.csum_offset = skb->csum_offset;
814                 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
815                         gso.flags = VIRTIO_NET_HDR_F_DATA_VALID;
816                 } /* else everything is zero */
817
818                 if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
819                                                sizeof(gso))))
820                         return -EFAULT;
821                 total += tun->vnet_hdr_sz;
822         }
823
824         len = min_t(int, skb->len, len);
825
826         skb_copy_datagram_const_iovec(skb, 0, iv, total, len);
827         total += skb->len;
828
829         tun->dev->stats.tx_packets++;
830         tun->dev->stats.tx_bytes += len;
831
832         return total;
833 }
834
835 static ssize_t tun_do_read(struct tun_struct *tun,
836                            struct kiocb *iocb, const struct iovec *iv,
837                            ssize_t len, int noblock)
838 {
839         DECLARE_WAITQUEUE(wait, current);
840         struct sk_buff *skb;
841         ssize_t ret = 0;
842
843         tun_debug(KERN_INFO, tun, "tun_chr_read\n");
844
845         if (unlikely(!noblock))
846                 add_wait_queue(&tun->wq.wait, &wait);
847         while (len) {
848                 current->state = TASK_INTERRUPTIBLE;
849
850                 /* Read frames from the queue */
851                 if (!(skb=skb_dequeue(&tun->socket.sk->sk_receive_queue))) {
852                         if (noblock) {
853                                 ret = -EAGAIN;
854                                 break;
855                         }
856                         if (signal_pending(current)) {
857                                 ret = -ERESTARTSYS;
858                                 break;
859                         }
860                         if (tun->dev->reg_state != NETREG_REGISTERED) {
861                                 ret = -EIO;
862                                 break;
863                         }
864
865                         /* Nothing to read, let's sleep */
866                         schedule();
867                         continue;
868                 }
869                 netif_wake_queue(tun->dev);
870
871                 ret = tun_put_user(tun, skb, iv, len);
872                 kfree_skb(skb);
873                 break;
874         }
875
876         current->state = TASK_RUNNING;
877         if (unlikely(!noblock))
878                 remove_wait_queue(&tun->wq.wait, &wait);
879
880         return ret;
881 }
882
883 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
884                             unsigned long count, loff_t pos)
885 {
886         struct file *file = iocb->ki_filp;
887         struct tun_file *tfile = file->private_data;
888         struct tun_struct *tun = __tun_get(tfile);
889         ssize_t len, ret;
890
891         if (!tun)
892                 return -EBADFD;
893         len = iov_length(iv, count);
894         if (len < 0) {
895                 ret = -EINVAL;
896                 goto out;
897         }
898
899         ret = tun_do_read(tun, iocb, iv, len, file->f_flags & O_NONBLOCK);
900         ret = min_t(ssize_t, ret, len);
901 out:
902         tun_put(tun);
903         return ret;
904 }
905
906 static void tun_setup(struct net_device *dev)
907 {
908         struct tun_struct *tun = netdev_priv(dev);
909
910         tun->owner = -1;
911         tun->group = -1;
912
913         dev->ethtool_ops = &tun_ethtool_ops;
914         dev->destructor = tun_free_netdev;
915 }
916
917 /* Trivial set of netlink ops to allow deleting tun or tap
918  * device with netlink.
919  */
920 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
921 {
922         return -EINVAL;
923 }
924
925 static struct rtnl_link_ops tun_link_ops __read_mostly = {
926         .kind           = DRV_NAME,
927         .priv_size      = sizeof(struct tun_struct),
928         .setup          = tun_setup,
929         .validate       = tun_validate,
930 };
931
932 static void tun_sock_write_space(struct sock *sk)
933 {
934         struct tun_struct *tun;
935         wait_queue_head_t *wqueue;
936
937         if (!sock_writeable(sk))
938                 return;
939
940         if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
941                 return;
942
943         wqueue = sk_sleep(sk);
944         if (wqueue && waitqueue_active(wqueue))
945                 wake_up_interruptible_sync_poll(wqueue, POLLOUT |
946                                                 POLLWRNORM | POLLWRBAND);
947
948         tun = tun_sk(sk)->tun;
949         kill_fasync(&tun->fasync, SIGIO, POLL_OUT);
950 }
951
952 static void tun_sock_destruct(struct sock *sk)
953 {
954         free_netdev(tun_sk(sk)->tun->dev);
955 }
956
957 static int tun_sendmsg(struct kiocb *iocb, struct socket *sock,
958                        struct msghdr *m, size_t total_len)
959 {
960         struct tun_struct *tun = container_of(sock, struct tun_struct, socket);
961         return tun_get_user(tun, m->msg_iov, total_len,
962                             m->msg_flags & MSG_DONTWAIT);
963 }
964
965 static int tun_recvmsg(struct kiocb *iocb, struct socket *sock,
966                        struct msghdr *m, size_t total_len,
967                        int flags)
968 {
969         struct tun_struct *tun = container_of(sock, struct tun_struct, socket);
970         int ret;
971         if (flags & ~(MSG_DONTWAIT|MSG_TRUNC))
972                 return -EINVAL;
973         ret = tun_do_read(tun, iocb, m->msg_iov, total_len,
974                           flags & MSG_DONTWAIT);
975         if (ret > total_len) {
976                 m->msg_flags |= MSG_TRUNC;
977                 ret = flags & MSG_TRUNC ? ret : total_len;
978         }
979         return ret;
980 }
981
982 static int tun_release(struct socket *sock)
983 {
984         if (sock->sk)
985                 sock_put(sock->sk);
986         return 0;
987 }
988
989 /* Ops structure to mimic raw sockets with tun */
990 static const struct proto_ops tun_socket_ops = {
991         .sendmsg = tun_sendmsg,
992         .recvmsg = tun_recvmsg,
993         .release = tun_release,
994 };
995
996 static struct proto tun_proto = {
997         .name           = "tun",
998         .owner          = THIS_MODULE,
999         .obj_size       = sizeof(struct tun_sock),
1000 };
1001
1002 static int tun_flags(struct tun_struct *tun)
1003 {
1004         int flags = 0;
1005
1006         if (tun->flags & TUN_TUN_DEV)
1007                 flags |= IFF_TUN;
1008         else
1009                 flags |= IFF_TAP;
1010
1011         if (tun->flags & TUN_NO_PI)
1012                 flags |= IFF_NO_PI;
1013
1014         if (tun->flags & TUN_ONE_QUEUE)
1015                 flags |= IFF_ONE_QUEUE;
1016
1017         if (tun->flags & TUN_VNET_HDR)
1018                 flags |= IFF_VNET_HDR;
1019
1020         return flags;
1021 }
1022
1023 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
1024                               char *buf)
1025 {
1026         struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1027         return sprintf(buf, "0x%x\n", tun_flags(tun));
1028 }
1029
1030 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
1031                               char *buf)
1032 {
1033         struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1034         return sprintf(buf, "%d\n", tun->owner);
1035 }
1036
1037 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
1038                               char *buf)
1039 {
1040         struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1041         return sprintf(buf, "%d\n", tun->group);
1042 }
1043
1044 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
1045 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
1046 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
1047
1048 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
1049 {
1050         struct sock *sk;
1051         struct tun_struct *tun;
1052         struct net_device *dev;
1053         int err;
1054
1055         dev = __dev_get_by_name(net, ifr->ifr_name);
1056         if (dev) {
1057                 const struct cred *cred = current_cred();
1058
1059                 if (ifr->ifr_flags & IFF_TUN_EXCL)
1060                         return -EBUSY;
1061                 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
1062                         tun = netdev_priv(dev);
1063                 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
1064                         tun = netdev_priv(dev);
1065                 else
1066                         return -EINVAL;
1067
1068                 if (((tun->owner != -1 && cred->euid != tun->owner) ||
1069                      (tun->group != -1 && !in_egroup_p(tun->group))) &&
1070                     !capable(CAP_NET_ADMIN))
1071                         return -EPERM;
1072                 err = security_tun_dev_attach(tun->socket.sk);
1073                 if (err < 0)
1074                         return err;
1075
1076                 err = tun_attach(tun, file);
1077                 if (err < 0)
1078                         return err;
1079         }
1080         else {
1081                 char *name;
1082                 unsigned long flags = 0;
1083
1084                 if (!capable(CAP_NET_ADMIN))
1085                         return -EPERM;
1086                 err = security_tun_dev_create();
1087                 if (err < 0)
1088                         return err;
1089
1090                 /* Set dev type */
1091                 if (ifr->ifr_flags & IFF_TUN) {
1092                         /* TUN device */
1093                         flags |= TUN_TUN_DEV;
1094                         name = "tun%d";
1095                 } else if (ifr->ifr_flags & IFF_TAP) {
1096                         /* TAP device */
1097                         flags |= TUN_TAP_DEV;
1098                         name = "tap%d";
1099                 } else
1100                         return -EINVAL;
1101
1102                 if (*ifr->ifr_name)
1103                         name = ifr->ifr_name;
1104
1105                 dev = alloc_netdev(sizeof(struct tun_struct), name,
1106                                    tun_setup);
1107                 if (!dev)
1108                         return -ENOMEM;
1109
1110                 dev_net_set(dev, net);
1111                 dev->rtnl_link_ops = &tun_link_ops;
1112
1113                 tun = netdev_priv(dev);
1114                 tun->dev = dev;
1115                 tun->flags = flags;
1116                 tun->txflt.count = 0;
1117                 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
1118
1119                 err = -ENOMEM;
1120                 sk = sk_alloc(&init_net, AF_UNSPEC, GFP_KERNEL, &tun_proto);
1121                 if (!sk)
1122                         goto err_free_dev;
1123
1124                 sk_change_net(sk, net);
1125                 tun->socket.wq = &tun->wq;
1126                 init_waitqueue_head(&tun->wq.wait);
1127                 tun->socket.ops = &tun_socket_ops;
1128                 sock_init_data(&tun->socket, sk);
1129                 sk->sk_write_space = tun_sock_write_space;
1130                 sk->sk_sndbuf = INT_MAX;
1131
1132                 tun_sk(sk)->tun = tun;
1133
1134                 security_tun_dev_post_create(sk);
1135
1136                 tun_net_init(dev);
1137
1138                 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
1139                         TUN_USER_FEATURES;
1140                 dev->features = dev->hw_features;
1141
1142                 err = register_netdevice(tun->dev);
1143                 if (err < 0)
1144                         goto err_free_sk;
1145
1146                 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
1147                     device_create_file(&tun->dev->dev, &dev_attr_owner) ||
1148                     device_create_file(&tun->dev->dev, &dev_attr_group))
1149                         pr_err("Failed to create tun sysfs files\n");
1150
1151                 sk->sk_destruct = tun_sock_destruct;
1152
1153                 err = tun_attach(tun, file);
1154                 if (err < 0)
1155                         goto failed;
1156         }
1157
1158         tun_debug(KERN_INFO, tun, "tun_set_iff\n");
1159
1160         if (ifr->ifr_flags & IFF_NO_PI)
1161                 tun->flags |= TUN_NO_PI;
1162         else
1163                 tun->flags &= ~TUN_NO_PI;
1164
1165         if (ifr->ifr_flags & IFF_ONE_QUEUE)
1166                 tun->flags |= TUN_ONE_QUEUE;
1167         else
1168                 tun->flags &= ~TUN_ONE_QUEUE;
1169
1170         if (ifr->ifr_flags & IFF_VNET_HDR)
1171                 tun->flags |= TUN_VNET_HDR;
1172         else
1173                 tun->flags &= ~TUN_VNET_HDR;
1174
1175         /* Make sure persistent devices do not get stuck in
1176          * xoff state.
1177          */
1178         if (netif_running(tun->dev))
1179                 netif_wake_queue(tun->dev);
1180
1181         strcpy(ifr->ifr_name, tun->dev->name);
1182         return 0;
1183
1184  err_free_sk:
1185         tun_free_netdev(dev);
1186  err_free_dev:
1187         free_netdev(dev);
1188  failed:
1189         return err;
1190 }
1191
1192 static int tun_get_iff(struct net *net, struct tun_struct *tun,
1193                        struct ifreq *ifr)
1194 {
1195         tun_debug(KERN_INFO, tun, "tun_get_iff\n");
1196
1197         strcpy(ifr->ifr_name, tun->dev->name);
1198
1199         ifr->ifr_flags = tun_flags(tun);
1200
1201         return 0;
1202 }
1203
1204 /* This is like a cut-down ethtool ops, except done via tun fd so no
1205  * privs required. */
1206 static int set_offload(struct tun_struct *tun, unsigned long arg)
1207 {
1208         netdev_features_t features = 0;
1209
1210         if (arg & TUN_F_CSUM) {
1211                 features |= NETIF_F_HW_CSUM;
1212                 arg &= ~TUN_F_CSUM;
1213
1214                 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1215                         if (arg & TUN_F_TSO_ECN) {
1216                                 features |= NETIF_F_TSO_ECN;
1217                                 arg &= ~TUN_F_TSO_ECN;
1218                         }
1219                         if (arg & TUN_F_TSO4)
1220                                 features |= NETIF_F_TSO;
1221                         if (arg & TUN_F_TSO6)
1222                                 features |= NETIF_F_TSO6;
1223                         arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1224                 }
1225
1226                 if (arg & TUN_F_UFO) {
1227                         features |= NETIF_F_UFO;
1228                         arg &= ~TUN_F_UFO;
1229                 }
1230         }
1231
1232         /* This gives the user a way to test for new features in future by
1233          * trying to set them. */
1234         if (arg)
1235                 return -EINVAL;
1236
1237         tun->set_features = features;
1238         netdev_update_features(tun->dev);
1239
1240         return 0;
1241 }
1242
1243 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
1244                             unsigned long arg, int ifreq_len)
1245 {
1246         struct tun_file *tfile = file->private_data;
1247         struct tun_struct *tun;
1248         void __user* argp = (void __user*)arg;
1249         struct sock_fprog fprog;
1250         struct ifreq ifr;
1251         int sndbuf;
1252         int vnet_hdr_sz;
1253         int ret;
1254
1255         if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
1256                 if (copy_from_user(&ifr, argp, ifreq_len))
1257                         return -EFAULT;
1258
1259         if (cmd == TUNGETFEATURES) {
1260                 /* Currently this just means: "what IFF flags are valid?".
1261                  * This is needed because we never checked for invalid flags on
1262                  * TUNSETIFF. */
1263                 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
1264                                 IFF_VNET_HDR,
1265                                 (unsigned int __user*)argp);
1266         }
1267
1268         rtnl_lock();
1269
1270         tun = __tun_get(tfile);
1271         if (cmd == TUNSETIFF && !tun) {
1272                 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1273
1274                 ret = tun_set_iff(tfile->net, file, &ifr);
1275
1276                 if (ret)
1277                         goto unlock;
1278
1279                 if (copy_to_user(argp, &ifr, ifreq_len))
1280                         ret = -EFAULT;
1281                 goto unlock;
1282         }
1283
1284         ret = -EBADFD;
1285         if (!tun)
1286                 goto unlock;
1287
1288         tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %d\n", cmd);
1289
1290         ret = 0;
1291         switch (cmd) {
1292         case TUNGETIFF:
1293                 ret = tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1294                 if (ret)
1295                         break;
1296
1297                 if (copy_to_user(argp, &ifr, ifreq_len))
1298                         ret = -EFAULT;
1299                 break;
1300
1301         case TUNSETNOCSUM:
1302                 /* Disable/Enable checksum */
1303
1304                 /* [unimplemented] */
1305                 tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n",
1306                           arg ? "disabled" : "enabled");
1307                 break;
1308
1309         case TUNSETPERSIST:
1310                 /* Disable/Enable persist mode */
1311                 if (arg)
1312                         tun->flags |= TUN_PERSIST;
1313                 else
1314                         tun->flags &= ~TUN_PERSIST;
1315
1316                 tun_debug(KERN_INFO, tun, "persist %s\n",
1317                           arg ? "enabled" : "disabled");
1318                 break;
1319
1320         case TUNSETOWNER:
1321                 /* Set owner of the device */
1322                 tun->owner = (uid_t) arg;
1323
1324                 tun_debug(KERN_INFO, tun, "owner set to %d\n", tun->owner);
1325                 break;
1326
1327         case TUNSETGROUP:
1328                 /* Set group of the device */
1329                 tun->group= (gid_t) arg;
1330
1331                 tun_debug(KERN_INFO, tun, "group set to %d\n", tun->group);
1332                 break;
1333
1334         case TUNSETLINK:
1335                 /* Only allow setting the type when the interface is down */
1336                 if (tun->dev->flags & IFF_UP) {
1337                         tun_debug(KERN_INFO, tun,
1338                                   "Linktype set failed because interface is up\n");
1339                         ret = -EBUSY;
1340                 } else {
1341                         tun->dev->type = (int) arg;
1342                         tun_debug(KERN_INFO, tun, "linktype set to %d\n",
1343                                   tun->dev->type);
1344                         ret = 0;
1345                 }
1346                 break;
1347
1348 #ifdef TUN_DEBUG
1349         case TUNSETDEBUG:
1350                 tun->debug = arg;
1351                 break;
1352 #endif
1353         case TUNSETOFFLOAD:
1354                 ret = set_offload(tun, arg);
1355                 break;
1356
1357         case TUNSETTXFILTER:
1358                 /* Can be set only for TAPs */
1359                 ret = -EINVAL;
1360                 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1361                         break;
1362                 ret = update_filter(&tun->txflt, (void __user *)arg);
1363                 break;
1364
1365         case SIOCGIFHWADDR:
1366                 /* Get hw address */
1367                 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
1368                 ifr.ifr_hwaddr.sa_family = tun->dev->type;
1369                 if (copy_to_user(argp, &ifr, ifreq_len))
1370                         ret = -EFAULT;
1371                 break;
1372
1373         case SIOCSIFHWADDR:
1374                 /* Set hw address */
1375                 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n",
1376                           ifr.ifr_hwaddr.sa_data);
1377
1378                 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
1379                 break;
1380
1381         case TUNGETSNDBUF:
1382                 sndbuf = tun->socket.sk->sk_sndbuf;
1383                 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
1384                         ret = -EFAULT;
1385                 break;
1386
1387         case TUNSETSNDBUF:
1388                 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
1389                         ret = -EFAULT;
1390                         break;
1391                 }
1392
1393                 tun->socket.sk->sk_sndbuf = sndbuf;
1394                 break;
1395
1396         case TUNGETVNETHDRSZ:
1397                 vnet_hdr_sz = tun->vnet_hdr_sz;
1398                 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
1399                         ret = -EFAULT;
1400                 break;
1401
1402         case TUNSETVNETHDRSZ:
1403                 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
1404                         ret = -EFAULT;
1405                         break;
1406                 }
1407                 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
1408                         ret = -EINVAL;
1409                         break;
1410                 }
1411
1412                 tun->vnet_hdr_sz = vnet_hdr_sz;
1413                 break;
1414
1415         case TUNATTACHFILTER:
1416                 /* Can be set only for TAPs */
1417                 ret = -EINVAL;
1418                 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1419                         break;
1420                 ret = -EFAULT;
1421                 if (copy_from_user(&fprog, argp, sizeof(fprog)))
1422                         break;
1423
1424                 ret = sk_attach_filter(&fprog, tun->socket.sk);
1425                 break;
1426
1427         case TUNDETACHFILTER:
1428                 /* Can be set only for TAPs */
1429                 ret = -EINVAL;
1430                 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1431                         break;
1432                 ret = sk_detach_filter(tun->socket.sk);
1433                 break;
1434
1435         default:
1436                 ret = -EINVAL;
1437                 break;
1438         }
1439
1440 unlock:
1441         rtnl_unlock();
1442         if (tun)
1443                 tun_put(tun);
1444         return ret;
1445 }
1446
1447 static long tun_chr_ioctl(struct file *file,
1448                           unsigned int cmd, unsigned long arg)
1449 {
1450         return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
1451 }
1452
1453 #ifdef CONFIG_COMPAT
1454 static long tun_chr_compat_ioctl(struct file *file,
1455                          unsigned int cmd, unsigned long arg)
1456 {
1457         switch (cmd) {
1458         case TUNSETIFF:
1459         case TUNGETIFF:
1460         case TUNSETTXFILTER:
1461         case TUNGETSNDBUF:
1462         case TUNSETSNDBUF:
1463         case SIOCGIFHWADDR:
1464         case SIOCSIFHWADDR:
1465                 arg = (unsigned long)compat_ptr(arg);
1466                 break;
1467         default:
1468                 arg = (compat_ulong_t)arg;
1469                 break;
1470         }
1471
1472         /*
1473          * compat_ifreq is shorter than ifreq, so we must not access beyond
1474          * the end of that structure. All fields that are used in this
1475          * driver are compatible though, we don't need to convert the
1476          * contents.
1477          */
1478         return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
1479 }
1480 #endif /* CONFIG_COMPAT */
1481
1482 static int tun_chr_fasync(int fd, struct file *file, int on)
1483 {
1484         struct tun_struct *tun = tun_get(file);
1485         int ret;
1486
1487         if (!tun)
1488                 return -EBADFD;
1489
1490         tun_debug(KERN_INFO, tun, "tun_chr_fasync %d\n", on);
1491
1492         if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
1493                 goto out;
1494
1495         if (on) {
1496                 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
1497                 if (ret)
1498                         goto out;
1499                 tun->flags |= TUN_FASYNC;
1500         } else
1501                 tun->flags &= ~TUN_FASYNC;
1502         ret = 0;
1503 out:
1504         tun_put(tun);
1505         return ret;
1506 }
1507
1508 static int tun_chr_open(struct inode *inode, struct file * file)
1509 {
1510         struct tun_file *tfile;
1511
1512         DBG1(KERN_INFO, "tunX: tun_chr_open\n");
1513
1514         tfile = kmalloc(sizeof(*tfile), GFP_KERNEL);
1515         if (!tfile)
1516                 return -ENOMEM;
1517         atomic_set(&tfile->count, 0);
1518         tfile->tun = NULL;
1519         tfile->net = get_net(current->nsproxy->net_ns);
1520         file->private_data = tfile;
1521         return 0;
1522 }
1523
1524 static int tun_chr_close(struct inode *inode, struct file *file)
1525 {
1526         struct tun_file *tfile = file->private_data;
1527         struct tun_struct *tun;
1528
1529         tun = __tun_get(tfile);
1530         if (tun) {
1531                 struct net_device *dev = tun->dev;
1532
1533                 tun_debug(KERN_INFO, tun, "tun_chr_close\n");
1534
1535                 __tun_detach(tun);
1536
1537                 /* If desirable, unregister the netdevice. */
1538                 if (!(tun->flags & TUN_PERSIST)) {
1539                         rtnl_lock();
1540                         if (dev->reg_state == NETREG_REGISTERED)
1541                                 unregister_netdevice(dev);
1542                         rtnl_unlock();
1543                 }
1544         }
1545
1546         tun = tfile->tun;
1547         if (tun)
1548                 sock_put(tun->socket.sk);
1549
1550         put_net(tfile->net);
1551         kfree(tfile);
1552
1553         return 0;
1554 }
1555
1556 static const struct file_operations tun_fops = {
1557         .owner  = THIS_MODULE,
1558         .llseek = no_llseek,
1559         .read  = do_sync_read,
1560         .aio_read  = tun_chr_aio_read,
1561         .write = do_sync_write,
1562         .aio_write = tun_chr_aio_write,
1563         .poll   = tun_chr_poll,
1564         .unlocked_ioctl = tun_chr_ioctl,
1565 #ifdef CONFIG_COMPAT
1566         .compat_ioctl = tun_chr_compat_ioctl,
1567 #endif
1568         .open   = tun_chr_open,
1569         .release = tun_chr_close,
1570         .fasync = tun_chr_fasync
1571 };
1572
1573 static struct miscdevice tun_miscdev = {
1574         .minor = TUN_MINOR,
1575         .name = "tun",
1576         .nodename = "net/tun",
1577         .fops = &tun_fops,
1578 };
1579
1580 /* ethtool interface */
1581
1582 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1583 {
1584         cmd->supported          = 0;
1585         cmd->advertising        = 0;
1586         ethtool_cmd_speed_set(cmd, SPEED_10);
1587         cmd->duplex             = DUPLEX_FULL;
1588         cmd->port               = PORT_TP;
1589         cmd->phy_address        = 0;
1590         cmd->transceiver        = XCVR_INTERNAL;
1591         cmd->autoneg            = AUTONEG_DISABLE;
1592         cmd->maxtxpkt           = 0;
1593         cmd->maxrxpkt           = 0;
1594         return 0;
1595 }
1596
1597 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
1598 {
1599         struct tun_struct *tun = netdev_priv(dev);
1600
1601         strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
1602         strlcpy(info->version, DRV_VERSION, sizeof(info->version));
1603
1604         switch (tun->flags & TUN_TYPE_MASK) {
1605         case TUN_TUN_DEV:
1606                 strlcpy(info->bus_info, "tun", sizeof(info->bus_info));
1607                 break;
1608         case TUN_TAP_DEV:
1609                 strlcpy(info->bus_info, "tap", sizeof(info->bus_info));
1610                 break;
1611         }
1612 }
1613
1614 static u32 tun_get_msglevel(struct net_device *dev)
1615 {
1616 #ifdef TUN_DEBUG
1617         struct tun_struct *tun = netdev_priv(dev);
1618         return tun->debug;
1619 #else
1620         return -EOPNOTSUPP;
1621 #endif
1622 }
1623
1624 static void tun_set_msglevel(struct net_device *dev, u32 value)
1625 {
1626 #ifdef TUN_DEBUG
1627         struct tun_struct *tun = netdev_priv(dev);
1628         tun->debug = value;
1629 #endif
1630 }
1631
1632 static const struct ethtool_ops tun_ethtool_ops = {
1633         .get_settings   = tun_get_settings,
1634         .get_drvinfo    = tun_get_drvinfo,
1635         .get_msglevel   = tun_get_msglevel,
1636         .set_msglevel   = tun_set_msglevel,
1637         .get_link       = ethtool_op_get_link,
1638 };
1639
1640
1641 static int __init tun_init(void)
1642 {
1643         int ret = 0;
1644
1645         pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
1646         pr_info("%s\n", DRV_COPYRIGHT);
1647
1648         ret = rtnl_link_register(&tun_link_ops);
1649         if (ret) {
1650                 pr_err("Can't register link_ops\n");
1651                 goto err_linkops;
1652         }
1653
1654         ret = misc_register(&tun_miscdev);
1655         if (ret) {
1656                 pr_err("Can't register misc device %d\n", TUN_MINOR);
1657                 goto err_misc;
1658         }
1659         return  0;
1660 err_misc:
1661         rtnl_link_unregister(&tun_link_ops);
1662 err_linkops:
1663         return ret;
1664 }
1665
1666 static void tun_cleanup(void)
1667 {
1668         misc_deregister(&tun_miscdev);
1669         rtnl_link_unregister(&tun_link_ops);
1670 }
1671
1672 /* Get an underlying socket object from tun file.  Returns error unless file is
1673  * attached to a device.  The returned object works like a packet socket, it
1674  * can be used for sock_sendmsg/sock_recvmsg.  The caller is responsible for
1675  * holding a reference to the file for as long as the socket is in use. */
1676 struct socket *tun_get_socket(struct file *file)
1677 {
1678         struct tun_struct *tun;
1679         if (file->f_op != &tun_fops)
1680                 return ERR_PTR(-EINVAL);
1681         tun = tun_get(file);
1682         if (!tun)
1683                 return ERR_PTR(-EBADFD);
1684         tun_put(tun);
1685         return &tun->socket;
1686 }
1687 EXPORT_SYMBOL_GPL(tun_get_socket);
1688
1689 module_init(tun_init);
1690 module_exit(tun_cleanup);
1691 MODULE_DESCRIPTION(DRV_DESCRIPTION);
1692 MODULE_AUTHOR(DRV_COPYRIGHT);
1693 MODULE_LICENSE("GPL");
1694 MODULE_ALIAS_MISCDEV(TUN_MINOR);
1695 MODULE_ALIAS("devname:net/tun");