ee1aab0805d1e218510317532212805f4305b2f6
[pandora-kernel.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/system.h>
73 #include <asm/uaccess.h>
74
75 /* Uncomment to enable debugging */
76 /* #define TUN_DEBUG 1 */
77
78 #ifdef TUN_DEBUG
79 static int debug;
80
81 #define tun_debug(level, tun, fmt, args...)                     \
82 do {                                                            \
83         if (tun->debug)                                         \
84                 netdev_printk(level, tun->dev, fmt, ##args);    \
85 } while (0)
86 #define DBG1(level, fmt, args...)                               \
87 do {                                                            \
88         if (debug == 2)                                         \
89                 printk(level fmt, ##args);                      \
90 } while (0)
91 #else
92 #define tun_debug(level, tun, fmt, args...)                     \
93 do {                                                            \
94         if (0)                                                  \
95                 netdev_printk(level, tun->dev, fmt, ##args);    \
96 } while (0)
97 #define DBG1(level, fmt, args...)                               \
98 do {                                                            \
99         if (0)                                                  \
100                 printk(level fmt, ##args);                      \
101 } while (0)
102 #endif
103
104 #define FLT_EXACT_COUNT 8
105 struct tap_filter {
106         unsigned int    count;    /* Number of addrs. Zero means disabled */
107         u32             mask[2];  /* Mask of the hashed addrs */
108         unsigned char   addr[FLT_EXACT_COUNT][ETH_ALEN];
109 };
110
111 struct tun_file {
112         atomic_t count;
113         struct tun_struct *tun;
114         struct net *net;
115 };
116
117 struct tun_sock;
118
119 struct tun_struct {
120         struct tun_file         *tfile;
121         unsigned int            flags;
122         uid_t                   owner;
123         gid_t                   group;
124
125         struct net_device       *dev;
126         u32                     set_features;
127 #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \
128                           NETIF_F_TSO6|NETIF_F_UFO)
129         struct fasync_struct    *fasync;
130
131         struct tap_filter       txflt;
132         struct socket           socket;
133         struct socket_wq        wq;
134
135         int                     vnet_hdr_sz;
136
137 #ifdef TUN_DEBUG
138         int debug;
139 #endif
140 };
141
142 struct tun_sock {
143         struct sock             sk;
144         struct tun_struct       *tun;
145 };
146
147 static inline struct tun_sock *tun_sk(struct sock *sk)
148 {
149         return container_of(sk, struct tun_sock, sk);
150 }
151
152 static int tun_attach(struct tun_struct *tun, struct file *file)
153 {
154         struct tun_file *tfile = file->private_data;
155         int err;
156
157         ASSERT_RTNL();
158
159         netif_tx_lock_bh(tun->dev);
160
161         err = -EINVAL;
162         if (tfile->tun)
163                 goto out;
164
165         err = -EBUSY;
166         if (tun->tfile)
167                 goto out;
168
169         err = 0;
170         tfile->tun = tun;
171         tun->tfile = tfile;
172         tun->socket.file = file;
173         netif_carrier_on(tun->dev);
174         dev_hold(tun->dev);
175         sock_hold(tun->socket.sk);
176         atomic_inc(&tfile->count);
177
178 out:
179         netif_tx_unlock_bh(tun->dev);
180         return err;
181 }
182
183 static void __tun_detach(struct tun_struct *tun)
184 {
185         /* Detach from net device */
186         netif_tx_lock_bh(tun->dev);
187         netif_carrier_off(tun->dev);
188         tun->tfile = NULL;
189         tun->socket.file = NULL;
190         netif_tx_unlock_bh(tun->dev);
191
192         /* Drop read queue */
193         skb_queue_purge(&tun->socket.sk->sk_receive_queue);
194
195         /* Drop the extra count on the net device */
196         dev_put(tun->dev);
197 }
198
199 static void tun_detach(struct tun_struct *tun)
200 {
201         rtnl_lock();
202         __tun_detach(tun);
203         rtnl_unlock();
204 }
205
206 static struct tun_struct *__tun_get(struct tun_file *tfile)
207 {
208         struct tun_struct *tun = NULL;
209
210         if (atomic_inc_not_zero(&tfile->count))
211                 tun = tfile->tun;
212
213         return tun;
214 }
215
216 static struct tun_struct *tun_get(struct file *file)
217 {
218         return __tun_get(file->private_data);
219 }
220
221 static void tun_put(struct tun_struct *tun)
222 {
223         struct tun_file *tfile = tun->tfile;
224
225         if (atomic_dec_and_test(&tfile->count))
226                 tun_detach(tfile->tun);
227 }
228
229 /* TAP filtering */
230 static void addr_hash_set(u32 *mask, const u8 *addr)
231 {
232         int n = ether_crc(ETH_ALEN, addr) >> 26;
233         mask[n >> 5] |= (1 << (n & 31));
234 }
235
236 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
237 {
238         int n = ether_crc(ETH_ALEN, addr) >> 26;
239         return mask[n >> 5] & (1 << (n & 31));
240 }
241
242 static int update_filter(struct tap_filter *filter, void __user *arg)
243 {
244         struct { u8 u[ETH_ALEN]; } *addr;
245         struct tun_filter uf;
246         int err, alen, n, nexact;
247
248         if (copy_from_user(&uf, arg, sizeof(uf)))
249                 return -EFAULT;
250
251         if (!uf.count) {
252                 /* Disabled */
253                 filter->count = 0;
254                 return 0;
255         }
256
257         alen = ETH_ALEN * uf.count;
258         addr = kmalloc(alen, GFP_KERNEL);
259         if (!addr)
260                 return -ENOMEM;
261
262         if (copy_from_user(addr, arg + sizeof(uf), alen)) {
263                 err = -EFAULT;
264                 goto done;
265         }
266
267         /* The filter is updated without holding any locks. Which is
268          * perfectly safe. We disable it first and in the worst
269          * case we'll accept a few undesired packets. */
270         filter->count = 0;
271         wmb();
272
273         /* Use first set of addresses as an exact filter */
274         for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
275                 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
276
277         nexact = n;
278
279         /* Remaining multicast addresses are hashed,
280          * unicast will leave the filter disabled. */
281         memset(filter->mask, 0, sizeof(filter->mask));
282         for (; n < uf.count; n++) {
283                 if (!is_multicast_ether_addr(addr[n].u)) {
284                         err = 0; /* no filter */
285                         goto done;
286                 }
287                 addr_hash_set(filter->mask, addr[n].u);
288         }
289
290         /* For ALLMULTI just set the mask to all ones.
291          * This overrides the mask populated above. */
292         if ((uf.flags & TUN_FLT_ALLMULTI))
293                 memset(filter->mask, ~0, sizeof(filter->mask));
294
295         /* Now enable the filter */
296         wmb();
297         filter->count = nexact;
298
299         /* Return the number of exact filters */
300         err = nexact;
301
302 done:
303         kfree(addr);
304         return err;
305 }
306
307 /* Returns: 0 - drop, !=0 - accept */
308 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
309 {
310         /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
311          * at this point. */
312         struct ethhdr *eh = (struct ethhdr *) skb->data;
313         int i;
314
315         /* Exact match */
316         for (i = 0; i < filter->count; i++)
317                 if (!compare_ether_addr(eh->h_dest, filter->addr[i]))
318                         return 1;
319
320         /* Inexact match (multicast only) */
321         if (is_multicast_ether_addr(eh->h_dest))
322                 return addr_hash_test(filter->mask, eh->h_dest);
323
324         return 0;
325 }
326
327 /*
328  * Checks whether the packet is accepted or not.
329  * Returns: 0 - drop, !=0 - accept
330  */
331 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
332 {
333         if (!filter->count)
334                 return 1;
335
336         return run_filter(filter, skb);
337 }
338
339 /* Network device part of the driver */
340
341 static const struct ethtool_ops tun_ethtool_ops;
342
343 /* Net device detach from fd. */
344 static void tun_net_uninit(struct net_device *dev)
345 {
346         struct tun_struct *tun = netdev_priv(dev);
347         struct tun_file *tfile = tun->tfile;
348
349         /* Inform the methods they need to stop using the dev.
350          */
351         if (tfile) {
352                 wake_up_all(&tun->wq.wait);
353                 if (atomic_dec_and_test(&tfile->count))
354                         __tun_detach(tun);
355         }
356 }
357
358 static void tun_free_netdev(struct net_device *dev)
359 {
360         struct tun_struct *tun = netdev_priv(dev);
361
362         sock_put(tun->socket.sk);
363 }
364
365 /* Net device open. */
366 static int tun_net_open(struct net_device *dev)
367 {
368         netif_start_queue(dev);
369         return 0;
370 }
371
372 /* Net device close. */
373 static int tun_net_close(struct net_device *dev)
374 {
375         netif_stop_queue(dev);
376         return 0;
377 }
378
379 /* Net device start xmit */
380 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
381 {
382         struct tun_struct *tun = netdev_priv(dev);
383
384         tun_debug(KERN_INFO, tun, "tun_net_xmit %d\n", skb->len);
385
386         /* Drop packet if interface is not attached */
387         if (!tun->tfile)
388                 goto drop;
389
390         /* Drop if the filter does not like it.
391          * This is a noop if the filter is disabled.
392          * Filter can be enabled only for the TAP devices. */
393         if (!check_filter(&tun->txflt, skb))
394                 goto drop;
395
396         if (tun->socket.sk->sk_filter &&
397             sk_filter(tun->socket.sk, skb))
398                 goto drop;
399
400         if (skb_queue_len(&tun->socket.sk->sk_receive_queue) >= dev->tx_queue_len) {
401                 if (!(tun->flags & TUN_ONE_QUEUE)) {
402                         /* Normal queueing mode. */
403                         /* Packet scheduler handles dropping of further packets. */
404                         netif_stop_queue(dev);
405
406                         /* We won't see all dropped packets individually, so overrun
407                          * error is more appropriate. */
408                         dev->stats.tx_fifo_errors++;
409                 } else {
410                         /* Single queue mode.
411                          * Driver handles dropping of all packets itself. */
412                         goto drop;
413                 }
414         }
415
416         /* Orphan the skb - required as we might hang on to it
417          * for indefinite time. */
418         skb_orphan(skb);
419
420         nf_reset(skb);
421
422         /* Enqueue packet */
423         skb_queue_tail(&tun->socket.sk->sk_receive_queue, skb);
424
425         /* Notify and wake up reader process */
426         if (tun->flags & TUN_FASYNC)
427                 kill_fasync(&tun->fasync, SIGIO, POLL_IN);
428         wake_up_interruptible_poll(&tun->wq.wait, POLLIN |
429                                    POLLRDNORM | POLLRDBAND);
430         return NETDEV_TX_OK;
431
432 drop:
433         dev->stats.tx_dropped++;
434         kfree_skb(skb);
435         return NETDEV_TX_OK;
436 }
437
438 static void tun_net_mclist(struct net_device *dev)
439 {
440         /*
441          * This callback is supposed to deal with mc filter in
442          * _rx_ path and has nothing to do with the _tx_ path.
443          * In rx path we always accept everything userspace gives us.
444          */
445 }
446
447 #define MIN_MTU 68
448 #define MAX_MTU 65535
449
450 static int
451 tun_net_change_mtu(struct net_device *dev, int new_mtu)
452 {
453         if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
454                 return -EINVAL;
455         dev->mtu = new_mtu;
456         return 0;
457 }
458
459 static u32 tun_net_fix_features(struct net_device *dev, u32 features)
460 {
461         struct tun_struct *tun = netdev_priv(dev);
462
463         return (features & tun->set_features) | (features & ~TUN_USER_FEATURES);
464 }
465 #ifdef CONFIG_NET_POLL_CONTROLLER
466 static void tun_poll_controller(struct net_device *dev)
467 {
468         /*
469          * Tun only receives frames when:
470          * 1) the char device endpoint gets data from user space
471          * 2) the tun socket gets a sendmsg call from user space
472          * Since both of those are syncronous operations, we are guaranteed
473          * never to have pending data when we poll for it
474          * so theres nothing to do here but return.
475          * We need this though so netpoll recognizes us as an interface that
476          * supports polling, which enables bridge devices in virt setups to
477          * still use netconsole
478          */
479         return;
480 }
481 #endif
482 static const struct net_device_ops tun_netdev_ops = {
483         .ndo_uninit             = tun_net_uninit,
484         .ndo_open               = tun_net_open,
485         .ndo_stop               = tun_net_close,
486         .ndo_start_xmit         = tun_net_xmit,
487         .ndo_change_mtu         = tun_net_change_mtu,
488         .ndo_fix_features       = tun_net_fix_features,
489 #ifdef CONFIG_NET_POLL_CONTROLLER
490         .ndo_poll_controller    = tun_poll_controller,
491 #endif
492 };
493
494 static const struct net_device_ops tap_netdev_ops = {
495         .ndo_uninit             = tun_net_uninit,
496         .ndo_open               = tun_net_open,
497         .ndo_stop               = tun_net_close,
498         .ndo_start_xmit         = tun_net_xmit,
499         .ndo_change_mtu         = tun_net_change_mtu,
500         .ndo_fix_features       = tun_net_fix_features,
501         .ndo_set_rx_mode        = tun_net_mclist,
502         .ndo_set_mac_address    = eth_mac_addr,
503         .ndo_validate_addr      = eth_validate_addr,
504 #ifdef CONFIG_NET_POLL_CONTROLLER
505         .ndo_poll_controller    = tun_poll_controller,
506 #endif
507 };
508
509 /* Initialize net device. */
510 static void tun_net_init(struct net_device *dev)
511 {
512         struct tun_struct *tun = netdev_priv(dev);
513
514         switch (tun->flags & TUN_TYPE_MASK) {
515         case TUN_TUN_DEV:
516                 dev->netdev_ops = &tun_netdev_ops;
517
518                 /* Point-to-Point TUN Device */
519                 dev->hard_header_len = 0;
520                 dev->addr_len = 0;
521                 dev->mtu = 1500;
522
523                 /* Zero header length */
524                 dev->type = ARPHRD_NONE;
525                 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
526                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
527                 break;
528
529         case TUN_TAP_DEV:
530                 dev->netdev_ops = &tap_netdev_ops;
531                 /* Ethernet TAP Device */
532                 ether_setup(dev);
533                 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
534
535                 random_ether_addr(dev->dev_addr);
536
537                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
538                 break;
539         }
540 }
541
542 /* Character device part */
543
544 /* Poll */
545 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
546 {
547         struct tun_file *tfile = file->private_data;
548         struct tun_struct *tun = __tun_get(tfile);
549         struct sock *sk;
550         unsigned int mask = 0;
551
552         if (!tun)
553                 return POLLERR;
554
555         sk = tun->socket.sk;
556
557         tun_debug(KERN_INFO, tun, "tun_chr_poll\n");
558
559         poll_wait(file, &tun->wq.wait, wait);
560
561         if (!skb_queue_empty(&sk->sk_receive_queue))
562                 mask |= POLLIN | POLLRDNORM;
563
564         if (sock_writeable(sk) ||
565             (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
566              sock_writeable(sk)))
567                 mask |= POLLOUT | POLLWRNORM;
568
569         if (tun->dev->reg_state != NETREG_REGISTERED)
570                 mask = POLLERR;
571
572         tun_put(tun);
573         return mask;
574 }
575
576 /* prepad is the amount to reserve at front.  len is length after that.
577  * linear is a hint as to how much to copy (usually headers). */
578 static struct sk_buff *tun_alloc_skb(struct tun_struct *tun,
579                                      size_t prepad, size_t len,
580                                      size_t linear, int noblock)
581 {
582         struct sock *sk = tun->socket.sk;
583         struct sk_buff *skb;
584         int err;
585
586         sock_update_classid(sk);
587
588         /* Under a page?  Don't bother with paged skb. */
589         if (prepad + len < PAGE_SIZE || !linear)
590                 linear = len;
591
592         skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
593                                    &err);
594         if (!skb)
595                 return ERR_PTR(err);
596
597         skb_reserve(skb, prepad);
598         skb_put(skb, linear);
599         skb->data_len = len - linear;
600         skb->len += len - linear;
601
602         return skb;
603 }
604
605 /* Get packet from user space buffer */
606 static ssize_t tun_get_user(struct tun_struct *tun,
607                             const struct iovec *iv, size_t count,
608                             int noblock)
609 {
610         struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
611         struct sk_buff *skb;
612         size_t len = count, align = NET_SKB_PAD;
613         struct virtio_net_hdr gso = { 0 };
614         int offset = 0;
615
616         if (!(tun->flags & TUN_NO_PI)) {
617                 if (len < sizeof(pi))
618                         return -EINVAL;
619                 len -= sizeof(pi);
620
621                 if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
622                         return -EFAULT;
623                 offset += sizeof(pi);
624         }
625
626         if (tun->flags & TUN_VNET_HDR) {
627                 if (len < tun->vnet_hdr_sz)
628                         return -EINVAL;
629                 len -= tun->vnet_hdr_sz;
630
631                 if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
632                         return -EFAULT;
633
634                 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
635                     gso.csum_start + gso.csum_offset + 2 > gso.hdr_len)
636                         gso.hdr_len = gso.csum_start + gso.csum_offset + 2;
637
638                 if (gso.hdr_len > len)
639                         return -EINVAL;
640                 offset += tun->vnet_hdr_sz;
641         }
642
643         if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
644                 align += NET_IP_ALIGN;
645                 if (unlikely(len < ETH_HLEN ||
646                              (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
647                         return -EINVAL;
648         }
649
650         skb = tun_alloc_skb(tun, align, len, gso.hdr_len, noblock);
651         if (IS_ERR(skb)) {
652                 if (PTR_ERR(skb) != -EAGAIN)
653                         tun->dev->stats.rx_dropped++;
654                 return PTR_ERR(skb);
655         }
656
657         if (skb_copy_datagram_from_iovec(skb, 0, iv, offset, len)) {
658                 tun->dev->stats.rx_dropped++;
659                 kfree_skb(skb);
660                 return -EFAULT;
661         }
662
663         if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
664                 if (!skb_partial_csum_set(skb, gso.csum_start,
665                                           gso.csum_offset)) {
666                         tun->dev->stats.rx_frame_errors++;
667                         kfree_skb(skb);
668                         return -EINVAL;
669                 }
670         }
671
672         switch (tun->flags & TUN_TYPE_MASK) {
673         case TUN_TUN_DEV:
674                 if (tun->flags & TUN_NO_PI) {
675                         switch (skb->data[0] & 0xf0) {
676                         case 0x40:
677                                 pi.proto = htons(ETH_P_IP);
678                                 break;
679                         case 0x60:
680                                 pi.proto = htons(ETH_P_IPV6);
681                                 break;
682                         default:
683                                 tun->dev->stats.rx_dropped++;
684                                 kfree_skb(skb);
685                                 return -EINVAL;
686                         }
687                 }
688
689                 skb_reset_mac_header(skb);
690                 skb->protocol = pi.proto;
691                 skb->dev = tun->dev;
692                 break;
693         case TUN_TAP_DEV:
694                 skb->protocol = eth_type_trans(skb, tun->dev);
695                 break;
696         }
697
698         if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
699                 pr_debug("GSO!\n");
700                 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
701                 case VIRTIO_NET_HDR_GSO_TCPV4:
702                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
703                         break;
704                 case VIRTIO_NET_HDR_GSO_TCPV6:
705                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
706                         break;
707                 case VIRTIO_NET_HDR_GSO_UDP:
708                         skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
709                         break;
710                 default:
711                         tun->dev->stats.rx_frame_errors++;
712                         kfree_skb(skb);
713                         return -EINVAL;
714                 }
715
716                 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
717                         skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
718
719                 skb_shinfo(skb)->gso_size = gso.gso_size;
720                 if (skb_shinfo(skb)->gso_size == 0) {
721                         tun->dev->stats.rx_frame_errors++;
722                         kfree_skb(skb);
723                         return -EINVAL;
724                 }
725
726                 /* Header must be checked, and gso_segs computed. */
727                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
728                 skb_shinfo(skb)->gso_segs = 0;
729         }
730
731         netif_rx_ni(skb);
732
733         tun->dev->stats.rx_packets++;
734         tun->dev->stats.rx_bytes += len;
735
736         return count;
737 }
738
739 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
740                               unsigned long count, loff_t pos)
741 {
742         struct file *file = iocb->ki_filp;
743         struct tun_struct *tun = tun_get(file);
744         ssize_t result;
745
746         if (!tun)
747                 return -EBADFD;
748
749         tun_debug(KERN_INFO, tun, "tun_chr_write %ld\n", count);
750
751         result = tun_get_user(tun, iv, iov_length(iv, count),
752                               file->f_flags & O_NONBLOCK);
753
754         tun_put(tun);
755         return result;
756 }
757
758 /* Put packet to the user space buffer */
759 static ssize_t tun_put_user(struct tun_struct *tun,
760                             struct sk_buff *skb,
761                             const struct iovec *iv, int len)
762 {
763         struct tun_pi pi = { 0, skb->protocol };
764         ssize_t total = 0;
765
766         if (!(tun->flags & TUN_NO_PI)) {
767                 if ((len -= sizeof(pi)) < 0)
768                         return -EINVAL;
769
770                 if (len < skb->len) {
771                         /* Packet will be striped */
772                         pi.flags |= TUN_PKT_STRIP;
773                 }
774
775                 if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi)))
776                         return -EFAULT;
777                 total += sizeof(pi);
778         }
779
780         if (tun->flags & TUN_VNET_HDR) {
781                 struct virtio_net_hdr gso = { 0 }; /* no info leak */
782                 if ((len -= tun->vnet_hdr_sz) < 0)
783                         return -EINVAL;
784
785                 if (skb_is_gso(skb)) {
786                         struct skb_shared_info *sinfo = skb_shinfo(skb);
787
788                         /* This is a hint as to how much should be linear. */
789                         gso.hdr_len = skb_headlen(skb);
790                         gso.gso_size = sinfo->gso_size;
791                         if (sinfo->gso_type & SKB_GSO_TCPV4)
792                                 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
793                         else if (sinfo->gso_type & SKB_GSO_TCPV6)
794                                 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
795                         else if (sinfo->gso_type & SKB_GSO_UDP)
796                                 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
797                         else {
798                                 pr_err("unexpected GSO type: "
799                                        "0x%x, gso_size %d, hdr_len %d\n",
800                                        sinfo->gso_type, gso.gso_size,
801                                        gso.hdr_len);
802                                 print_hex_dump(KERN_ERR, "tun: ",
803                                                DUMP_PREFIX_NONE,
804                                                16, 1, skb->head,
805                                                min((int)gso.hdr_len, 64), true);
806                                 WARN_ON_ONCE(1);
807                                 return -EINVAL;
808                         }
809                         if (sinfo->gso_type & SKB_GSO_TCP_ECN)
810                                 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
811                 } else
812                         gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
813
814                 if (skb->ip_summed == CHECKSUM_PARTIAL) {
815                         gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
816                         gso.csum_start = skb_checksum_start_offset(skb);
817                         gso.csum_offset = skb->csum_offset;
818                 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
819                         gso.flags = VIRTIO_NET_HDR_F_DATA_VALID;
820                 } /* else everything is zero */
821
822                 if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
823                                                sizeof(gso))))
824                         return -EFAULT;
825                 total += tun->vnet_hdr_sz;
826         }
827
828         len = min_t(int, skb->len, len);
829
830         skb_copy_datagram_const_iovec(skb, 0, iv, total, len);
831         total += skb->len;
832
833         tun->dev->stats.tx_packets++;
834         tun->dev->stats.tx_bytes += len;
835
836         return total;
837 }
838
839 static ssize_t tun_do_read(struct tun_struct *tun,
840                            struct kiocb *iocb, const struct iovec *iv,
841                            ssize_t len, int noblock)
842 {
843         DECLARE_WAITQUEUE(wait, current);
844         struct sk_buff *skb;
845         ssize_t ret = 0;
846
847         tun_debug(KERN_INFO, tun, "tun_chr_read\n");
848
849         if (unlikely(!noblock))
850                 add_wait_queue(&tun->wq.wait, &wait);
851         while (len) {
852                 current->state = TASK_INTERRUPTIBLE;
853
854                 /* Read frames from the queue */
855                 if (!(skb=skb_dequeue(&tun->socket.sk->sk_receive_queue))) {
856                         if (noblock) {
857                                 ret = -EAGAIN;
858                                 break;
859                         }
860                         if (signal_pending(current)) {
861                                 ret = -ERESTARTSYS;
862                                 break;
863                         }
864                         if (tun->dev->reg_state != NETREG_REGISTERED) {
865                                 ret = -EIO;
866                                 break;
867                         }
868
869                         /* Nothing to read, let's sleep */
870                         schedule();
871                         continue;
872                 }
873                 netif_wake_queue(tun->dev);
874
875                 ret = tun_put_user(tun, skb, iv, len);
876                 kfree_skb(skb);
877                 break;
878         }
879
880         current->state = TASK_RUNNING;
881         if (unlikely(!noblock))
882                 remove_wait_queue(&tun->wq.wait, &wait);
883
884         return ret;
885 }
886
887 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
888                             unsigned long count, loff_t pos)
889 {
890         struct file *file = iocb->ki_filp;
891         struct tun_file *tfile = file->private_data;
892         struct tun_struct *tun = __tun_get(tfile);
893         ssize_t len, ret;
894
895         if (!tun)
896                 return -EBADFD;
897         len = iov_length(iv, count);
898         if (len < 0) {
899                 ret = -EINVAL;
900                 goto out;
901         }
902
903         ret = tun_do_read(tun, iocb, iv, len, file->f_flags & O_NONBLOCK);
904         ret = min_t(ssize_t, ret, len);
905 out:
906         tun_put(tun);
907         return ret;
908 }
909
910 static void tun_setup(struct net_device *dev)
911 {
912         struct tun_struct *tun = netdev_priv(dev);
913
914         tun->owner = -1;
915         tun->group = -1;
916
917         dev->ethtool_ops = &tun_ethtool_ops;
918         dev->destructor = tun_free_netdev;
919 }
920
921 /* Trivial set of netlink ops to allow deleting tun or tap
922  * device with netlink.
923  */
924 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
925 {
926         return -EINVAL;
927 }
928
929 static struct rtnl_link_ops tun_link_ops __read_mostly = {
930         .kind           = DRV_NAME,
931         .priv_size      = sizeof(struct tun_struct),
932         .setup          = tun_setup,
933         .validate       = tun_validate,
934 };
935
936 static void tun_sock_write_space(struct sock *sk)
937 {
938         struct tun_struct *tun;
939         wait_queue_head_t *wqueue;
940
941         if (!sock_writeable(sk))
942                 return;
943
944         if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
945                 return;
946
947         wqueue = sk_sleep(sk);
948         if (wqueue && waitqueue_active(wqueue))
949                 wake_up_interruptible_sync_poll(wqueue, POLLOUT |
950                                                 POLLWRNORM | POLLWRBAND);
951
952         tun = tun_sk(sk)->tun;
953         kill_fasync(&tun->fasync, SIGIO, POLL_OUT);
954 }
955
956 static void tun_sock_destruct(struct sock *sk)
957 {
958         free_netdev(tun_sk(sk)->tun->dev);
959 }
960
961 static int tun_sendmsg(struct kiocb *iocb, struct socket *sock,
962                        struct msghdr *m, size_t total_len)
963 {
964         struct tun_struct *tun = container_of(sock, struct tun_struct, socket);
965         return tun_get_user(tun, m->msg_iov, total_len,
966                             m->msg_flags & MSG_DONTWAIT);
967 }
968
969 static int tun_recvmsg(struct kiocb *iocb, struct socket *sock,
970                        struct msghdr *m, size_t total_len,
971                        int flags)
972 {
973         struct tun_struct *tun = container_of(sock, struct tun_struct, socket);
974         int ret;
975         if (flags & ~(MSG_DONTWAIT|MSG_TRUNC))
976                 return -EINVAL;
977         ret = tun_do_read(tun, iocb, m->msg_iov, total_len,
978                           flags & MSG_DONTWAIT);
979         if (ret > total_len) {
980                 m->msg_flags |= MSG_TRUNC;
981                 ret = flags & MSG_TRUNC ? ret : total_len;
982         }
983         return ret;
984 }
985
986 /* Ops structure to mimic raw sockets with tun */
987 static const struct proto_ops tun_socket_ops = {
988         .sendmsg = tun_sendmsg,
989         .recvmsg = tun_recvmsg,
990 };
991
992 static struct proto tun_proto = {
993         .name           = "tun",
994         .owner          = THIS_MODULE,
995         .obj_size       = sizeof(struct tun_sock),
996 };
997
998 static int tun_flags(struct tun_struct *tun)
999 {
1000         int flags = 0;
1001
1002         if (tun->flags & TUN_TUN_DEV)
1003                 flags |= IFF_TUN;
1004         else
1005                 flags |= IFF_TAP;
1006
1007         if (tun->flags & TUN_NO_PI)
1008                 flags |= IFF_NO_PI;
1009
1010         if (tun->flags & TUN_ONE_QUEUE)
1011                 flags |= IFF_ONE_QUEUE;
1012
1013         if (tun->flags & TUN_VNET_HDR)
1014                 flags |= IFF_VNET_HDR;
1015
1016         return flags;
1017 }
1018
1019 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
1020                               char *buf)
1021 {
1022         struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1023         return sprintf(buf, "0x%x\n", tun_flags(tun));
1024 }
1025
1026 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
1027                               char *buf)
1028 {
1029         struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1030         return sprintf(buf, "%d\n", tun->owner);
1031 }
1032
1033 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
1034                               char *buf)
1035 {
1036         struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1037         return sprintf(buf, "%d\n", tun->group);
1038 }
1039
1040 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
1041 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
1042 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
1043
1044 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
1045 {
1046         struct sock *sk;
1047         struct tun_struct *tun;
1048         struct net_device *dev;
1049         int err;
1050
1051         dev = __dev_get_by_name(net, ifr->ifr_name);
1052         if (dev) {
1053                 const struct cred *cred = current_cred();
1054
1055                 if (ifr->ifr_flags & IFF_TUN_EXCL)
1056                         return -EBUSY;
1057                 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
1058                         tun = netdev_priv(dev);
1059                 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
1060                         tun = netdev_priv(dev);
1061                 else
1062                         return -EINVAL;
1063
1064                 if (((tun->owner != -1 && cred->euid != tun->owner) ||
1065                      (tun->group != -1 && !in_egroup_p(tun->group))) &&
1066                     !capable(CAP_NET_ADMIN))
1067                         return -EPERM;
1068                 err = security_tun_dev_attach(tun->socket.sk);
1069                 if (err < 0)
1070                         return err;
1071
1072                 err = tun_attach(tun, file);
1073                 if (err < 0)
1074                         return err;
1075         }
1076         else {
1077                 char *name;
1078                 unsigned long flags = 0;
1079
1080                 if (!capable(CAP_NET_ADMIN))
1081                         return -EPERM;
1082                 err = security_tun_dev_create();
1083                 if (err < 0)
1084                         return err;
1085
1086                 /* Set dev type */
1087                 if (ifr->ifr_flags & IFF_TUN) {
1088                         /* TUN device */
1089                         flags |= TUN_TUN_DEV;
1090                         name = "tun%d";
1091                 } else if (ifr->ifr_flags & IFF_TAP) {
1092                         /* TAP device */
1093                         flags |= TUN_TAP_DEV;
1094                         name = "tap%d";
1095                 } else
1096                         return -EINVAL;
1097
1098                 if (*ifr->ifr_name)
1099                         name = ifr->ifr_name;
1100
1101                 dev = alloc_netdev(sizeof(struct tun_struct), name,
1102                                    tun_setup);
1103                 if (!dev)
1104                         return -ENOMEM;
1105
1106                 dev_net_set(dev, net);
1107                 dev->rtnl_link_ops = &tun_link_ops;
1108
1109                 tun = netdev_priv(dev);
1110                 tun->dev = dev;
1111                 tun->flags = flags;
1112                 tun->txflt.count = 0;
1113                 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
1114
1115                 err = -ENOMEM;
1116                 sk = sk_alloc(net, AF_UNSPEC, GFP_KERNEL, &tun_proto);
1117                 if (!sk)
1118                         goto err_free_dev;
1119
1120                 tun->socket.wq = &tun->wq;
1121                 init_waitqueue_head(&tun->wq.wait);
1122                 tun->socket.ops = &tun_socket_ops;
1123                 sock_init_data(&tun->socket, sk);
1124                 sk->sk_write_space = tun_sock_write_space;
1125                 sk->sk_sndbuf = INT_MAX;
1126
1127                 tun_sk(sk)->tun = tun;
1128
1129                 security_tun_dev_post_create(sk);
1130
1131                 tun_net_init(dev);
1132
1133                 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
1134                         TUN_USER_FEATURES;
1135                 dev->features = dev->hw_features;
1136
1137                 err = register_netdevice(tun->dev);
1138                 if (err < 0)
1139                         goto err_free_sk;
1140
1141                 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
1142                     device_create_file(&tun->dev->dev, &dev_attr_owner) ||
1143                     device_create_file(&tun->dev->dev, &dev_attr_group))
1144                         pr_err("Failed to create tun sysfs files\n");
1145
1146                 sk->sk_destruct = tun_sock_destruct;
1147
1148                 err = tun_attach(tun, file);
1149                 if (err < 0)
1150                         goto failed;
1151         }
1152
1153         tun_debug(KERN_INFO, tun, "tun_set_iff\n");
1154
1155         if (ifr->ifr_flags & IFF_NO_PI)
1156                 tun->flags |= TUN_NO_PI;
1157         else
1158                 tun->flags &= ~TUN_NO_PI;
1159
1160         if (ifr->ifr_flags & IFF_ONE_QUEUE)
1161                 tun->flags |= TUN_ONE_QUEUE;
1162         else
1163                 tun->flags &= ~TUN_ONE_QUEUE;
1164
1165         if (ifr->ifr_flags & IFF_VNET_HDR)
1166                 tun->flags |= TUN_VNET_HDR;
1167         else
1168                 tun->flags &= ~TUN_VNET_HDR;
1169
1170         /* Make sure persistent devices do not get stuck in
1171          * xoff state.
1172          */
1173         if (netif_running(tun->dev))
1174                 netif_wake_queue(tun->dev);
1175
1176         strcpy(ifr->ifr_name, tun->dev->name);
1177         return 0;
1178
1179  err_free_sk:
1180         sock_put(sk);
1181  err_free_dev:
1182         free_netdev(dev);
1183  failed:
1184         return err;
1185 }
1186
1187 static int tun_get_iff(struct net *net, struct tun_struct *tun,
1188                        struct ifreq *ifr)
1189 {
1190         tun_debug(KERN_INFO, tun, "tun_get_iff\n");
1191
1192         strcpy(ifr->ifr_name, tun->dev->name);
1193
1194         ifr->ifr_flags = tun_flags(tun);
1195
1196         return 0;
1197 }
1198
1199 /* This is like a cut-down ethtool ops, except done via tun fd so no
1200  * privs required. */
1201 static int set_offload(struct tun_struct *tun, unsigned long arg)
1202 {
1203         u32 features = 0;
1204
1205         if (arg & TUN_F_CSUM) {
1206                 features |= NETIF_F_HW_CSUM;
1207                 arg &= ~TUN_F_CSUM;
1208
1209                 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1210                         if (arg & TUN_F_TSO_ECN) {
1211                                 features |= NETIF_F_TSO_ECN;
1212                                 arg &= ~TUN_F_TSO_ECN;
1213                         }
1214                         if (arg & TUN_F_TSO4)
1215                                 features |= NETIF_F_TSO;
1216                         if (arg & TUN_F_TSO6)
1217                                 features |= NETIF_F_TSO6;
1218                         arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1219                 }
1220
1221                 if (arg & TUN_F_UFO) {
1222                         features |= NETIF_F_UFO;
1223                         arg &= ~TUN_F_UFO;
1224                 }
1225         }
1226
1227         /* This gives the user a way to test for new features in future by
1228          * trying to set them. */
1229         if (arg)
1230                 return -EINVAL;
1231
1232         tun->set_features = features;
1233         netdev_update_features(tun->dev);
1234
1235         return 0;
1236 }
1237
1238 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
1239                             unsigned long arg, int ifreq_len)
1240 {
1241         struct tun_file *tfile = file->private_data;
1242         struct tun_struct *tun;
1243         void __user* argp = (void __user*)arg;
1244         struct sock_fprog fprog;
1245         struct ifreq ifr;
1246         int sndbuf;
1247         int vnet_hdr_sz;
1248         int ret;
1249
1250         if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89) {
1251                 if (copy_from_user(&ifr, argp, ifreq_len))
1252                         return -EFAULT;
1253         } else {
1254                 memset(&ifr, 0, sizeof(ifr));
1255         }
1256         if (cmd == TUNGETFEATURES) {
1257                 /* Currently this just means: "what IFF flags are valid?".
1258                  * This is needed because we never checked for invalid flags on
1259                  * TUNSETIFF. */
1260                 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
1261                                 IFF_VNET_HDR,
1262                                 (unsigned int __user*)argp);
1263         }
1264
1265         rtnl_lock();
1266
1267         tun = __tun_get(tfile);
1268         if (cmd == TUNSETIFF && !tun) {
1269                 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1270
1271                 ret = tun_set_iff(tfile->net, file, &ifr);
1272
1273                 if (ret)
1274                         goto unlock;
1275
1276                 if (copy_to_user(argp, &ifr, ifreq_len))
1277                         ret = -EFAULT;
1278                 goto unlock;
1279         }
1280
1281         ret = -EBADFD;
1282         if (!tun)
1283                 goto unlock;
1284
1285         tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %d\n", cmd);
1286
1287         ret = 0;
1288         switch (cmd) {
1289         case TUNGETIFF:
1290                 ret = tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1291                 if (ret)
1292                         break;
1293
1294                 if (copy_to_user(argp, &ifr, ifreq_len))
1295                         ret = -EFAULT;
1296                 break;
1297
1298         case TUNSETNOCSUM:
1299                 /* Disable/Enable checksum */
1300
1301                 /* [unimplemented] */
1302                 tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n",
1303                           arg ? "disabled" : "enabled");
1304                 break;
1305
1306         case TUNSETPERSIST:
1307                 /* Disable/Enable persist mode */
1308                 if (arg)
1309                         tun->flags |= TUN_PERSIST;
1310                 else
1311                         tun->flags &= ~TUN_PERSIST;
1312
1313                 tun_debug(KERN_INFO, tun, "persist %s\n",
1314                           arg ? "enabled" : "disabled");
1315                 break;
1316
1317         case TUNSETOWNER:
1318                 /* Set owner of the device */
1319                 tun->owner = (uid_t) arg;
1320
1321                 tun_debug(KERN_INFO, tun, "owner set to %d\n", tun->owner);
1322                 break;
1323
1324         case TUNSETGROUP:
1325                 /* Set group of the device */
1326                 tun->group= (gid_t) arg;
1327
1328                 tun_debug(KERN_INFO, tun, "group set to %d\n", tun->group);
1329                 break;
1330
1331         case TUNSETLINK:
1332                 /* Only allow setting the type when the interface is down */
1333                 if (tun->dev->flags & IFF_UP) {
1334                         tun_debug(KERN_INFO, tun,
1335                                   "Linktype set failed because interface is up\n");
1336                         ret = -EBUSY;
1337                 } else {
1338                         tun->dev->type = (int) arg;
1339                         tun_debug(KERN_INFO, tun, "linktype set to %d\n",
1340                                   tun->dev->type);
1341                         ret = 0;
1342                 }
1343                 break;
1344
1345 #ifdef TUN_DEBUG
1346         case TUNSETDEBUG:
1347                 tun->debug = arg;
1348                 break;
1349 #endif
1350         case TUNSETOFFLOAD:
1351                 ret = set_offload(tun, arg);
1352                 break;
1353
1354         case TUNSETTXFILTER:
1355                 /* Can be set only for TAPs */
1356                 ret = -EINVAL;
1357                 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1358                         break;
1359                 ret = update_filter(&tun->txflt, (void __user *)arg);
1360                 break;
1361
1362         case SIOCGIFHWADDR:
1363                 /* Get hw address */
1364                 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
1365                 ifr.ifr_hwaddr.sa_family = tun->dev->type;
1366                 if (copy_to_user(argp, &ifr, ifreq_len))
1367                         ret = -EFAULT;
1368                 break;
1369
1370         case SIOCSIFHWADDR:
1371                 /* Set hw address */
1372                 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n",
1373                           ifr.ifr_hwaddr.sa_data);
1374
1375                 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
1376                 break;
1377
1378         case TUNGETSNDBUF:
1379                 sndbuf = tun->socket.sk->sk_sndbuf;
1380                 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
1381                         ret = -EFAULT;
1382                 break;
1383
1384         case TUNSETSNDBUF:
1385                 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
1386                         ret = -EFAULT;
1387                         break;
1388                 }
1389
1390                 tun->socket.sk->sk_sndbuf = sndbuf;
1391                 break;
1392
1393         case TUNGETVNETHDRSZ:
1394                 vnet_hdr_sz = tun->vnet_hdr_sz;
1395                 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
1396                         ret = -EFAULT;
1397                 break;
1398
1399         case TUNSETVNETHDRSZ:
1400                 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
1401                         ret = -EFAULT;
1402                         break;
1403                 }
1404                 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
1405                         ret = -EINVAL;
1406                         break;
1407                 }
1408
1409                 tun->vnet_hdr_sz = vnet_hdr_sz;
1410                 break;
1411
1412         case TUNATTACHFILTER:
1413                 /* Can be set only for TAPs */
1414                 ret = -EINVAL;
1415                 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1416                         break;
1417                 ret = -EFAULT;
1418                 if (copy_from_user(&fprog, argp, sizeof(fprog)))
1419                         break;
1420
1421                 ret = sk_attach_filter(&fprog, tun->socket.sk);
1422                 break;
1423
1424         case TUNDETACHFILTER:
1425                 /* Can be set only for TAPs */
1426                 ret = -EINVAL;
1427                 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1428                         break;
1429                 ret = sk_detach_filter(tun->socket.sk);
1430                 break;
1431
1432         default:
1433                 ret = -EINVAL;
1434                 break;
1435         }
1436
1437 unlock:
1438         rtnl_unlock();
1439         if (tun)
1440                 tun_put(tun);
1441         return ret;
1442 }
1443
1444 static long tun_chr_ioctl(struct file *file,
1445                           unsigned int cmd, unsigned long arg)
1446 {
1447         return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
1448 }
1449
1450 #ifdef CONFIG_COMPAT
1451 static long tun_chr_compat_ioctl(struct file *file,
1452                          unsigned int cmd, unsigned long arg)
1453 {
1454         switch (cmd) {
1455         case TUNSETIFF:
1456         case TUNGETIFF:
1457         case TUNSETTXFILTER:
1458         case TUNGETSNDBUF:
1459         case TUNSETSNDBUF:
1460         case SIOCGIFHWADDR:
1461         case SIOCSIFHWADDR:
1462                 arg = (unsigned long)compat_ptr(arg);
1463                 break;
1464         default:
1465                 arg = (compat_ulong_t)arg;
1466                 break;
1467         }
1468
1469         /*
1470          * compat_ifreq is shorter than ifreq, so we must not access beyond
1471          * the end of that structure. All fields that are used in this
1472          * driver are compatible though, we don't need to convert the
1473          * contents.
1474          */
1475         return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
1476 }
1477 #endif /* CONFIG_COMPAT */
1478
1479 static int tun_chr_fasync(int fd, struct file *file, int on)
1480 {
1481         struct tun_struct *tun = tun_get(file);
1482         int ret;
1483
1484         if (!tun)
1485                 return -EBADFD;
1486
1487         tun_debug(KERN_INFO, tun, "tun_chr_fasync %d\n", on);
1488
1489         if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
1490                 goto out;
1491
1492         if (on) {
1493                 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
1494                 if (ret)
1495                         goto out;
1496                 tun->flags |= TUN_FASYNC;
1497         } else
1498                 tun->flags &= ~TUN_FASYNC;
1499         ret = 0;
1500 out:
1501         tun_put(tun);
1502         return ret;
1503 }
1504
1505 static int tun_chr_open(struct inode *inode, struct file * file)
1506 {
1507         struct tun_file *tfile;
1508
1509         DBG1(KERN_INFO, "tunX: tun_chr_open\n");
1510
1511         tfile = kmalloc(sizeof(*tfile), GFP_KERNEL);
1512         if (!tfile)
1513                 return -ENOMEM;
1514         atomic_set(&tfile->count, 0);
1515         tfile->tun = NULL;
1516         tfile->net = get_net(current->nsproxy->net_ns);
1517         file->private_data = tfile;
1518         return 0;
1519 }
1520
1521 static int tun_chr_close(struct inode *inode, struct file *file)
1522 {
1523         struct tun_file *tfile = file->private_data;
1524         struct tun_struct *tun;
1525
1526         tun = __tun_get(tfile);
1527         if (tun) {
1528                 struct net_device *dev = tun->dev;
1529
1530                 tun_debug(KERN_INFO, tun, "tun_chr_close\n");
1531
1532                 __tun_detach(tun);
1533
1534                 /* If desirable, unregister the netdevice. */
1535                 if (!(tun->flags & TUN_PERSIST)) {
1536                         rtnl_lock();
1537                         if (dev->reg_state == NETREG_REGISTERED)
1538                                 unregister_netdevice(dev);
1539                         rtnl_unlock();
1540                 }
1541         }
1542
1543         tun = tfile->tun;
1544         if (tun)
1545                 sock_put(tun->socket.sk);
1546
1547         put_net(tfile->net);
1548         kfree(tfile);
1549
1550         return 0;
1551 }
1552
1553 static const struct file_operations tun_fops = {
1554         .owner  = THIS_MODULE,
1555         .llseek = no_llseek,
1556         .read  = do_sync_read,
1557         .aio_read  = tun_chr_aio_read,
1558         .write = do_sync_write,
1559         .aio_write = tun_chr_aio_write,
1560         .poll   = tun_chr_poll,
1561         .unlocked_ioctl = tun_chr_ioctl,
1562 #ifdef CONFIG_COMPAT
1563         .compat_ioctl = tun_chr_compat_ioctl,
1564 #endif
1565         .open   = tun_chr_open,
1566         .release = tun_chr_close,
1567         .fasync = tun_chr_fasync
1568 };
1569
1570 static struct miscdevice tun_miscdev = {
1571         .minor = TUN_MINOR,
1572         .name = "tun",
1573         .nodename = "net/tun",
1574         .fops = &tun_fops,
1575 };
1576
1577 /* ethtool interface */
1578
1579 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1580 {
1581         cmd->supported          = 0;
1582         cmd->advertising        = 0;
1583         ethtool_cmd_speed_set(cmd, SPEED_10);
1584         cmd->duplex             = DUPLEX_FULL;
1585         cmd->port               = PORT_TP;
1586         cmd->phy_address        = 0;
1587         cmd->transceiver        = XCVR_INTERNAL;
1588         cmd->autoneg            = AUTONEG_DISABLE;
1589         cmd->maxtxpkt           = 0;
1590         cmd->maxrxpkt           = 0;
1591         return 0;
1592 }
1593
1594 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
1595 {
1596         struct tun_struct *tun = netdev_priv(dev);
1597
1598         strcpy(info->driver, DRV_NAME);
1599         strcpy(info->version, DRV_VERSION);
1600         strcpy(info->fw_version, "N/A");
1601
1602         switch (tun->flags & TUN_TYPE_MASK) {
1603         case TUN_TUN_DEV:
1604                 strcpy(info->bus_info, "tun");
1605                 break;
1606         case TUN_TAP_DEV:
1607                 strcpy(info->bus_info, "tap");
1608                 break;
1609         }
1610 }
1611
1612 static u32 tun_get_msglevel(struct net_device *dev)
1613 {
1614 #ifdef TUN_DEBUG
1615         struct tun_struct *tun = netdev_priv(dev);
1616         return tun->debug;
1617 #else
1618         return -EOPNOTSUPP;
1619 #endif
1620 }
1621
1622 static void tun_set_msglevel(struct net_device *dev, u32 value)
1623 {
1624 #ifdef TUN_DEBUG
1625         struct tun_struct *tun = netdev_priv(dev);
1626         tun->debug = value;
1627 #endif
1628 }
1629
1630 static const struct ethtool_ops tun_ethtool_ops = {
1631         .get_settings   = tun_get_settings,
1632         .get_drvinfo    = tun_get_drvinfo,
1633         .get_msglevel   = tun_get_msglevel,
1634         .set_msglevel   = tun_set_msglevel,
1635         .get_link       = ethtool_op_get_link,
1636 };
1637
1638
1639 static int __init tun_init(void)
1640 {
1641         int ret = 0;
1642
1643         pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
1644         pr_info("%s\n", DRV_COPYRIGHT);
1645
1646         ret = rtnl_link_register(&tun_link_ops);
1647         if (ret) {
1648                 pr_err("Can't register link_ops\n");
1649                 goto err_linkops;
1650         }
1651
1652         ret = misc_register(&tun_miscdev);
1653         if (ret) {
1654                 pr_err("Can't register misc device %d\n", TUN_MINOR);
1655                 goto err_misc;
1656         }
1657         return  0;
1658 err_misc:
1659         rtnl_link_unregister(&tun_link_ops);
1660 err_linkops:
1661         return ret;
1662 }
1663
1664 static void tun_cleanup(void)
1665 {
1666         misc_deregister(&tun_miscdev);
1667         rtnl_link_unregister(&tun_link_ops);
1668 }
1669
1670 /* Get an underlying socket object from tun file.  Returns error unless file is
1671  * attached to a device.  The returned object works like a packet socket, it
1672  * can be used for sock_sendmsg/sock_recvmsg.  The caller is responsible for
1673  * holding a reference to the file for as long as the socket is in use. */
1674 struct socket *tun_get_socket(struct file *file)
1675 {
1676         struct tun_struct *tun;
1677         if (file->f_op != &tun_fops)
1678                 return ERR_PTR(-EINVAL);
1679         tun = tun_get(file);
1680         if (!tun)
1681                 return ERR_PTR(-EBADFD);
1682         tun_put(tun);
1683         return &tun->socket;
1684 }
1685 EXPORT_SYMBOL_GPL(tun_get_socket);
1686
1687 module_init(tun_init);
1688 module_exit(tun_cleanup);
1689 MODULE_DESCRIPTION(DRV_DESCRIPTION);
1690 MODULE_AUTHOR(DRV_COPYRIGHT);
1691 MODULE_LICENSE("GPL");
1692 MODULE_ALIAS_MISCDEV(TUN_MINOR);
1693 MODULE_ALIAS("devname:net/tun");