pch_can: fix 800k comms issue
[linux-2.6.git] / drivers / net / tun.c
1 /*
2  *  TUN - Universal TUN/TAP device driver.
3  *  Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com>
4  *
5  *  This program is free software; you can redistribute it and/or modify
6  *  it under the terms of the GNU General Public License as published by
7  *  the Free Software Foundation; either version 2 of the License, or
8  *  (at your option) any later version.
9  *
10  *  This program is distributed in the hope that it will be useful,
11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13  *  GNU General Public License for more details.
14  *
15  *  $Id: tun.c,v 1.15 2002/03/01 02:44:24 maxk Exp $
16  */
17
18 /*
19  *  Changes:
20  *
21  *  Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14
22  *    Add TUNSETLINK ioctl to set the link encapsulation
23  *
24  *  Mark Smith <markzzzsmith@yahoo.com.au>
25  *    Use random_ether_addr() for tap MAC address.
26  *
27  *  Harald Roelle <harald.roelle@ifi.lmu.de>  2004/04/20
28  *    Fixes in packet dropping, queue length setting and queue wakeup.
29  *    Increased default tx queue length.
30  *    Added ethtool API.
31  *    Minor cleanups
32  *
33  *  Daniel Podlejski <underley@underley.eu.org>
34  *    Modifications for 2.3.99-pre5 kernel.
35  */
36
37 #define DRV_NAME        "tun"
38 #define DRV_VERSION     "1.6"
39 #define DRV_DESCRIPTION "Universal TUN/TAP device driver"
40 #define DRV_COPYRIGHT   "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>"
41
42 #include <linux/module.h>
43 #include <linux/errno.h>
44 #include <linux/kernel.h>
45 #include <linux/major.h>
46 #include <linux/slab.h>
47 #include <linux/poll.h>
48 #include <linux/fcntl.h>
49 #include <linux/init.h>
50 #include <linux/skbuff.h>
51 #include <linux/netdevice.h>
52 #include <linux/etherdevice.h>
53 #include <linux/miscdevice.h>
54 #include <linux/ethtool.h>
55 #include <linux/rtnetlink.h>
56 #include <linux/compat.h>
57 #include <linux/if.h>
58 #include <linux/if_arp.h>
59 #include <linux/if_ether.h>
60 #include <linux/if_tun.h>
61 #include <linux/crc32.h>
62 #include <linux/nsproxy.h>
63 #include <linux/virtio_net.h>
64 #include <linux/rcupdate.h>
65 #include <net/net_namespace.h>
66 #include <net/netns/generic.h>
67 #include <net/rtnetlink.h>
68 #include <net/sock.h>
69
70 #include <asm/system.h>
71 #include <asm/uaccess.h>
72
73 /* Uncomment to enable debugging */
74 /* #define TUN_DEBUG 1 */
75
76 #ifdef TUN_DEBUG
77 static int debug;
78
79 #define DBG  if(tun->debug)printk
80 #define DBG1 if(debug==2)printk
81 #else
82 #define DBG( a... )
83 #define DBG1( a... )
84 #endif
85
86 #define FLT_EXACT_COUNT 8
87 struct tap_filter {
88         unsigned int    count;    /* Number of addrs. Zero means disabled */
89         u32             mask[2];  /* Mask of the hashed addrs */
90         unsigned char   addr[FLT_EXACT_COUNT][ETH_ALEN];
91 };
92
93 struct tun_file {
94         atomic_t count;
95         struct tun_struct *tun;
96         struct net *net;
97 };
98
99 struct tun_sock;
100
101 struct tun_struct {
102         struct tun_file         *tfile;
103         unsigned int            flags;
104         uid_t                   owner;
105         gid_t                   group;
106
107         struct net_device       *dev;
108         struct fasync_struct    *fasync;
109
110         struct tap_filter       txflt;
111         struct socket           socket;
112         struct socket_wq        wq;
113
114         int                     vnet_hdr_sz;
115
116 #ifdef TUN_DEBUG
117         int debug;
118 #endif
119 };
120
121 struct tun_sock {
122         struct sock             sk;
123         struct tun_struct       *tun;
124 };
125
126 static inline struct tun_sock *tun_sk(struct sock *sk)
127 {
128         return container_of(sk, struct tun_sock, sk);
129 }
130
131 static int tun_attach(struct tun_struct *tun, struct file *file)
132 {
133         struct tun_file *tfile = file->private_data;
134         int err;
135
136         ASSERT_RTNL();
137
138         netif_tx_lock_bh(tun->dev);
139
140         err = -EINVAL;
141         if (tfile->tun)
142                 goto out;
143
144         err = -EBUSY;
145         if (tun->tfile)
146                 goto out;
147
148         err = 0;
149         tfile->tun = tun;
150         tun->tfile = tfile;
151         tun->socket.file = file;
152         netif_carrier_on(tun->dev);
153         dev_hold(tun->dev);
154         sock_hold(tun->socket.sk);
155         atomic_inc(&tfile->count);
156
157 out:
158         netif_tx_unlock_bh(tun->dev);
159         return err;
160 }
161
162 static void __tun_detach(struct tun_struct *tun)
163 {
164         /* Detach from net device */
165         netif_tx_lock_bh(tun->dev);
166         netif_carrier_off(tun->dev);
167         tun->tfile = NULL;
168         tun->socket.file = NULL;
169         netif_tx_unlock_bh(tun->dev);
170
171         /* Drop read queue */
172         skb_queue_purge(&tun->socket.sk->sk_receive_queue);
173
174         /* Drop the extra count on the net device */
175         dev_put(tun->dev);
176 }
177
178 static void tun_detach(struct tun_struct *tun)
179 {
180         rtnl_lock();
181         __tun_detach(tun);
182         rtnl_unlock();
183 }
184
185 static struct tun_struct *__tun_get(struct tun_file *tfile)
186 {
187         struct tun_struct *tun = NULL;
188
189         if (atomic_inc_not_zero(&tfile->count))
190                 tun = tfile->tun;
191
192         return tun;
193 }
194
195 static struct tun_struct *tun_get(struct file *file)
196 {
197         return __tun_get(file->private_data);
198 }
199
200 static void tun_put(struct tun_struct *tun)
201 {
202         struct tun_file *tfile = tun->tfile;
203
204         if (atomic_dec_and_test(&tfile->count))
205                 tun_detach(tfile->tun);
206 }
207
208 /* TAP filterting */
209 static void addr_hash_set(u32 *mask, const u8 *addr)
210 {
211         int n = ether_crc(ETH_ALEN, addr) >> 26;
212         mask[n >> 5] |= (1 << (n & 31));
213 }
214
215 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
216 {
217         int n = ether_crc(ETH_ALEN, addr) >> 26;
218         return mask[n >> 5] & (1 << (n & 31));
219 }
220
221 static int update_filter(struct tap_filter *filter, void __user *arg)
222 {
223         struct { u8 u[ETH_ALEN]; } *addr;
224         struct tun_filter uf;
225         int err, alen, n, nexact;
226
227         if (copy_from_user(&uf, arg, sizeof(uf)))
228                 return -EFAULT;
229
230         if (!uf.count) {
231                 /* Disabled */
232                 filter->count = 0;
233                 return 0;
234         }
235
236         alen = ETH_ALEN * uf.count;
237         addr = kmalloc(alen, GFP_KERNEL);
238         if (!addr)
239                 return -ENOMEM;
240
241         if (copy_from_user(addr, arg + sizeof(uf), alen)) {
242                 err = -EFAULT;
243                 goto done;
244         }
245
246         /* The filter is updated without holding any locks. Which is
247          * perfectly safe. We disable it first and in the worst
248          * case we'll accept a few undesired packets. */
249         filter->count = 0;
250         wmb();
251
252         /* Use first set of addresses as an exact filter */
253         for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
254                 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
255
256         nexact = n;
257
258         /* Remaining multicast addresses are hashed,
259          * unicast will leave the filter disabled. */
260         memset(filter->mask, 0, sizeof(filter->mask));
261         for (; n < uf.count; n++) {
262                 if (!is_multicast_ether_addr(addr[n].u)) {
263                         err = 0; /* no filter */
264                         goto done;
265                 }
266                 addr_hash_set(filter->mask, addr[n].u);
267         }
268
269         /* For ALLMULTI just set the mask to all ones.
270          * This overrides the mask populated above. */
271         if ((uf.flags & TUN_FLT_ALLMULTI))
272                 memset(filter->mask, ~0, sizeof(filter->mask));
273
274         /* Now enable the filter */
275         wmb();
276         filter->count = nexact;
277
278         /* Return the number of exact filters */
279         err = nexact;
280
281 done:
282         kfree(addr);
283         return err;
284 }
285
286 /* Returns: 0 - drop, !=0 - accept */
287 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
288 {
289         /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
290          * at this point. */
291         struct ethhdr *eh = (struct ethhdr *) skb->data;
292         int i;
293
294         /* Exact match */
295         for (i = 0; i < filter->count; i++)
296                 if (!compare_ether_addr(eh->h_dest, filter->addr[i]))
297                         return 1;
298
299         /* Inexact match (multicast only) */
300         if (is_multicast_ether_addr(eh->h_dest))
301                 return addr_hash_test(filter->mask, eh->h_dest);
302
303         return 0;
304 }
305
306 /*
307  * Checks whether the packet is accepted or not.
308  * Returns: 0 - drop, !=0 - accept
309  */
310 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
311 {
312         if (!filter->count)
313                 return 1;
314
315         return run_filter(filter, skb);
316 }
317
318 /* Network device part of the driver */
319
320 static const struct ethtool_ops tun_ethtool_ops;
321
322 /* Net device detach from fd. */
323 static void tun_net_uninit(struct net_device *dev)
324 {
325         struct tun_struct *tun = netdev_priv(dev);
326         struct tun_file *tfile = tun->tfile;
327
328         /* Inform the methods they need to stop using the dev.
329          */
330         if (tfile) {
331                 wake_up_all(&tun->wq.wait);
332                 if (atomic_dec_and_test(&tfile->count))
333                         __tun_detach(tun);
334         }
335 }
336
337 static void tun_free_netdev(struct net_device *dev)
338 {
339         struct tun_struct *tun = netdev_priv(dev);
340
341         sock_put(tun->socket.sk);
342 }
343
344 /* Net device open. */
345 static int tun_net_open(struct net_device *dev)
346 {
347         netif_start_queue(dev);
348         return 0;
349 }
350
351 /* Net device close. */
352 static int tun_net_close(struct net_device *dev)
353 {
354         netif_stop_queue(dev);
355         return 0;
356 }
357
358 /* Net device start xmit */
359 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
360 {
361         struct tun_struct *tun = netdev_priv(dev);
362
363         DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len);
364
365         /* Drop packet if interface is not attached */
366         if (!tun->tfile)
367                 goto drop;
368
369         /* Drop if the filter does not like it.
370          * This is a noop if the filter is disabled.
371          * Filter can be enabled only for the TAP devices. */
372         if (!check_filter(&tun->txflt, skb))
373                 goto drop;
374
375         if (tun->socket.sk->sk_filter &&
376             sk_filter(tun->socket.sk, skb))
377                 goto drop;
378
379         if (skb_queue_len(&tun->socket.sk->sk_receive_queue) >= dev->tx_queue_len) {
380                 if (!(tun->flags & TUN_ONE_QUEUE)) {
381                         /* Normal queueing mode. */
382                         /* Packet scheduler handles dropping of further packets. */
383                         netif_stop_queue(dev);
384
385                         /* We won't see all dropped packets individually, so overrun
386                          * error is more appropriate. */
387                         dev->stats.tx_fifo_errors++;
388                 } else {
389                         /* Single queue mode.
390                          * Driver handles dropping of all packets itself. */
391                         goto drop;
392                 }
393         }
394
395         /* Orphan the skb - required as we might hang on to it
396          * for indefinite time. */
397         skb_orphan(skb);
398
399         /* Enqueue packet */
400         skb_queue_tail(&tun->socket.sk->sk_receive_queue, skb);
401
402         /* Notify and wake up reader process */
403         if (tun->flags & TUN_FASYNC)
404                 kill_fasync(&tun->fasync, SIGIO, POLL_IN);
405         wake_up_interruptible_poll(&tun->wq.wait, POLLIN |
406                                    POLLRDNORM | POLLRDBAND);
407         return NETDEV_TX_OK;
408
409 drop:
410         dev->stats.tx_dropped++;
411         kfree_skb(skb);
412         return NETDEV_TX_OK;
413 }
414
415 static void tun_net_mclist(struct net_device *dev)
416 {
417         /*
418          * This callback is supposed to deal with mc filter in
419          * _rx_ path and has nothing to do with the _tx_ path.
420          * In rx path we always accept everything userspace gives us.
421          */
422 }
423
424 #define MIN_MTU 68
425 #define MAX_MTU 65535
426
427 static int
428 tun_net_change_mtu(struct net_device *dev, int new_mtu)
429 {
430         if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
431                 return -EINVAL;
432         dev->mtu = new_mtu;
433         return 0;
434 }
435
436 static const struct net_device_ops tun_netdev_ops = {
437         .ndo_uninit             = tun_net_uninit,
438         .ndo_open               = tun_net_open,
439         .ndo_stop               = tun_net_close,
440         .ndo_start_xmit         = tun_net_xmit,
441         .ndo_change_mtu         = tun_net_change_mtu,
442 };
443
444 static const struct net_device_ops tap_netdev_ops = {
445         .ndo_uninit             = tun_net_uninit,
446         .ndo_open               = tun_net_open,
447         .ndo_stop               = tun_net_close,
448         .ndo_start_xmit         = tun_net_xmit,
449         .ndo_change_mtu         = tun_net_change_mtu,
450         .ndo_set_multicast_list = tun_net_mclist,
451         .ndo_set_mac_address    = eth_mac_addr,
452         .ndo_validate_addr      = eth_validate_addr,
453 };
454
455 /* Initialize net device. */
456 static void tun_net_init(struct net_device *dev)
457 {
458         struct tun_struct *tun = netdev_priv(dev);
459
460         switch (tun->flags & TUN_TYPE_MASK) {
461         case TUN_TUN_DEV:
462                 dev->netdev_ops = &tun_netdev_ops;
463
464                 /* Point-to-Point TUN Device */
465                 dev->hard_header_len = 0;
466                 dev->addr_len = 0;
467                 dev->mtu = 1500;
468
469                 /* Zero header length */
470                 dev->type = ARPHRD_NONE;
471                 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
472                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
473                 break;
474
475         case TUN_TAP_DEV:
476                 dev->netdev_ops = &tap_netdev_ops;
477                 /* Ethernet TAP Device */
478                 ether_setup(dev);
479
480                 random_ether_addr(dev->dev_addr);
481
482                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
483                 break;
484         }
485 }
486
487 /* Character device part */
488
489 /* Poll */
490 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
491 {
492         struct tun_file *tfile = file->private_data;
493         struct tun_struct *tun = __tun_get(tfile);
494         struct sock *sk;
495         unsigned int mask = 0;
496
497         if (!tun)
498                 return POLLERR;
499
500         sk = tun->socket.sk;
501
502         DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name);
503
504         poll_wait(file, &tun->wq.wait, wait);
505
506         if (!skb_queue_empty(&sk->sk_receive_queue))
507                 mask |= POLLIN | POLLRDNORM;
508
509         if (sock_writeable(sk) ||
510             (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
511              sock_writeable(sk)))
512                 mask |= POLLOUT | POLLWRNORM;
513
514         if (tun->dev->reg_state != NETREG_REGISTERED)
515                 mask = POLLERR;
516
517         tun_put(tun);
518         return mask;
519 }
520
521 /* prepad is the amount to reserve at front.  len is length after that.
522  * linear is a hint as to how much to copy (usually headers). */
523 static inline struct sk_buff *tun_alloc_skb(struct tun_struct *tun,
524                                             size_t prepad, size_t len,
525                                             size_t linear, int noblock)
526 {
527         struct sock *sk = tun->socket.sk;
528         struct sk_buff *skb;
529         int err;
530
531         sock_update_classid(sk);
532
533         /* Under a page?  Don't bother with paged skb. */
534         if (prepad + len < PAGE_SIZE || !linear)
535                 linear = len;
536
537         skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
538                                    &err);
539         if (!skb)
540                 return ERR_PTR(err);
541
542         skb_reserve(skb, prepad);
543         skb_put(skb, linear);
544         skb->data_len = len - linear;
545         skb->len += len - linear;
546
547         return skb;
548 }
549
550 /* Get packet from user space buffer */
551 static __inline__ ssize_t tun_get_user(struct tun_struct *tun,
552                                        const struct iovec *iv, size_t count,
553                                        int noblock)
554 {
555         struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
556         struct sk_buff *skb;
557         size_t len = count, align = 0;
558         struct virtio_net_hdr gso = { 0 };
559         int offset = 0;
560
561         if (!(tun->flags & TUN_NO_PI)) {
562                 if ((len -= sizeof(pi)) > count)
563                         return -EINVAL;
564
565                 if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
566                         return -EFAULT;
567                 offset += sizeof(pi);
568         }
569
570         if (tun->flags & TUN_VNET_HDR) {
571                 if ((len -= tun->vnet_hdr_sz) > count)
572                         return -EINVAL;
573
574                 if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
575                         return -EFAULT;
576
577                 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
578                     gso.csum_start + gso.csum_offset + 2 > gso.hdr_len)
579                         gso.hdr_len = gso.csum_start + gso.csum_offset + 2;
580
581                 if (gso.hdr_len > len)
582                         return -EINVAL;
583                 offset += tun->vnet_hdr_sz;
584         }
585
586         if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
587                 align = NET_IP_ALIGN;
588                 if (unlikely(len < ETH_HLEN ||
589                              (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
590                         return -EINVAL;
591         }
592
593         skb = tun_alloc_skb(tun, align, len, gso.hdr_len, noblock);
594         if (IS_ERR(skb)) {
595                 if (PTR_ERR(skb) != -EAGAIN)
596                         tun->dev->stats.rx_dropped++;
597                 return PTR_ERR(skb);
598         }
599
600         if (skb_copy_datagram_from_iovec(skb, 0, iv, offset, len)) {
601                 tun->dev->stats.rx_dropped++;
602                 kfree_skb(skb);
603                 return -EFAULT;
604         }
605
606         if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
607                 if (!skb_partial_csum_set(skb, gso.csum_start,
608                                           gso.csum_offset)) {
609                         tun->dev->stats.rx_frame_errors++;
610                         kfree_skb(skb);
611                         return -EINVAL;
612                 }
613         } else if (tun->flags & TUN_NOCHECKSUM)
614                 skb->ip_summed = CHECKSUM_UNNECESSARY;
615
616         switch (tun->flags & TUN_TYPE_MASK) {
617         case TUN_TUN_DEV:
618                 if (tun->flags & TUN_NO_PI) {
619                         switch (skb->data[0] & 0xf0) {
620                         case 0x40:
621                                 pi.proto = htons(ETH_P_IP);
622                                 break;
623                         case 0x60:
624                                 pi.proto = htons(ETH_P_IPV6);
625                                 break;
626                         default:
627                                 tun->dev->stats.rx_dropped++;
628                                 kfree_skb(skb);
629                                 return -EINVAL;
630                         }
631                 }
632
633                 skb_reset_mac_header(skb);
634                 skb->protocol = pi.proto;
635                 skb->dev = tun->dev;
636                 break;
637         case TUN_TAP_DEV:
638                 skb->protocol = eth_type_trans(skb, tun->dev);
639                 break;
640         };
641
642         if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
643                 pr_debug("GSO!\n");
644                 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
645                 case VIRTIO_NET_HDR_GSO_TCPV4:
646                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
647                         break;
648                 case VIRTIO_NET_HDR_GSO_TCPV6:
649                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
650                         break;
651                 case VIRTIO_NET_HDR_GSO_UDP:
652                         skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
653                         break;
654                 default:
655                         tun->dev->stats.rx_frame_errors++;
656                         kfree_skb(skb);
657                         return -EINVAL;
658                 }
659
660                 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
661                         skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
662
663                 skb_shinfo(skb)->gso_size = gso.gso_size;
664                 if (skb_shinfo(skb)->gso_size == 0) {
665                         tun->dev->stats.rx_frame_errors++;
666                         kfree_skb(skb);
667                         return -EINVAL;
668                 }
669
670                 /* Header must be checked, and gso_segs computed. */
671                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
672                 skb_shinfo(skb)->gso_segs = 0;
673         }
674
675         netif_rx_ni(skb);
676
677         tun->dev->stats.rx_packets++;
678         tun->dev->stats.rx_bytes += len;
679
680         return count;
681 }
682
683 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
684                               unsigned long count, loff_t pos)
685 {
686         struct file *file = iocb->ki_filp;
687         struct tun_struct *tun = tun_get(file);
688         ssize_t result;
689
690         if (!tun)
691                 return -EBADFD;
692
693         DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);
694
695         result = tun_get_user(tun, iv, iov_length(iv, count),
696                               file->f_flags & O_NONBLOCK);
697
698         tun_put(tun);
699         return result;
700 }
701
702 /* Put packet to the user space buffer */
703 static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
704                                        struct sk_buff *skb,
705                                        const struct iovec *iv, int len)
706 {
707         struct tun_pi pi = { 0, skb->protocol };
708         ssize_t total = 0;
709
710         if (!(tun->flags & TUN_NO_PI)) {
711                 if ((len -= sizeof(pi)) < 0)
712                         return -EINVAL;
713
714                 if (len < skb->len) {
715                         /* Packet will be striped */
716                         pi.flags |= TUN_PKT_STRIP;
717                 }
718
719                 if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi)))
720                         return -EFAULT;
721                 total += sizeof(pi);
722         }
723
724         if (tun->flags & TUN_VNET_HDR) {
725                 struct virtio_net_hdr gso = { 0 }; /* no info leak */
726                 if ((len -= tun->vnet_hdr_sz) < 0)
727                         return -EINVAL;
728
729                 if (skb_is_gso(skb)) {
730                         struct skb_shared_info *sinfo = skb_shinfo(skb);
731
732                         /* This is a hint as to how much should be linear. */
733                         gso.hdr_len = skb_headlen(skb);
734                         gso.gso_size = sinfo->gso_size;
735                         if (sinfo->gso_type & SKB_GSO_TCPV4)
736                                 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
737                         else if (sinfo->gso_type & SKB_GSO_TCPV6)
738                                 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
739                         else if (sinfo->gso_type & SKB_GSO_UDP)
740                                 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
741                         else {
742                                 printk(KERN_ERR "tun: unexpected GSO type: "
743                                        "0x%x, gso_size %d, hdr_len %d\n",
744                                        sinfo->gso_type, gso.gso_size,
745                                        gso.hdr_len);
746                                 print_hex_dump(KERN_ERR, "tun: ",
747                                                DUMP_PREFIX_NONE,
748                                                16, 1, skb->head,
749                                                min((int)gso.hdr_len, 64), true);
750                                 WARN_ON_ONCE(1);
751                                 return -EINVAL;
752                         }
753                         if (sinfo->gso_type & SKB_GSO_TCP_ECN)
754                                 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
755                 } else
756                         gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
757
758                 if (skb->ip_summed == CHECKSUM_PARTIAL) {
759                         gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
760                         gso.csum_start = skb_checksum_start_offset(skb);
761                         gso.csum_offset = skb->csum_offset;
762                 } /* else everything is zero */
763
764                 if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
765                                                sizeof(gso))))
766                         return -EFAULT;
767                 total += tun->vnet_hdr_sz;
768         }
769
770         len = min_t(int, skb->len, len);
771
772         skb_copy_datagram_const_iovec(skb, 0, iv, total, len);
773         total += skb->len;
774
775         tun->dev->stats.tx_packets++;
776         tun->dev->stats.tx_bytes += len;
777
778         return total;
779 }
780
781 static ssize_t tun_do_read(struct tun_struct *tun,
782                            struct kiocb *iocb, const struct iovec *iv,
783                            ssize_t len, int noblock)
784 {
785         DECLARE_WAITQUEUE(wait, current);
786         struct sk_buff *skb;
787         ssize_t ret = 0;
788
789         DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
790
791         add_wait_queue(&tun->wq.wait, &wait);
792         while (len) {
793                 current->state = TASK_INTERRUPTIBLE;
794
795                 /* Read frames from the queue */
796                 if (!(skb=skb_dequeue(&tun->socket.sk->sk_receive_queue))) {
797                         if (noblock) {
798                                 ret = -EAGAIN;
799                                 break;
800                         }
801                         if (signal_pending(current)) {
802                                 ret = -ERESTARTSYS;
803                                 break;
804                         }
805                         if (tun->dev->reg_state != NETREG_REGISTERED) {
806                                 ret = -EIO;
807                                 break;
808                         }
809
810                         /* Nothing to read, let's sleep */
811                         schedule();
812                         continue;
813                 }
814                 netif_wake_queue(tun->dev);
815
816                 ret = tun_put_user(tun, skb, iv, len);
817                 kfree_skb(skb);
818                 break;
819         }
820
821         current->state = TASK_RUNNING;
822         remove_wait_queue(&tun->wq.wait, &wait);
823
824         return ret;
825 }
826
827 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
828                             unsigned long count, loff_t pos)
829 {
830         struct file *file = iocb->ki_filp;
831         struct tun_file *tfile = file->private_data;
832         struct tun_struct *tun = __tun_get(tfile);
833         ssize_t len, ret;
834
835         if (!tun)
836                 return -EBADFD;
837         len = iov_length(iv, count);
838         if (len < 0) {
839                 ret = -EINVAL;
840                 goto out;
841         }
842
843         ret = tun_do_read(tun, iocb, iv, len, file->f_flags & O_NONBLOCK);
844         ret = min_t(ssize_t, ret, len);
845 out:
846         tun_put(tun);
847         return ret;
848 }
849
850 static void tun_setup(struct net_device *dev)
851 {
852         struct tun_struct *tun = netdev_priv(dev);
853
854         tun->owner = -1;
855         tun->group = -1;
856
857         dev->ethtool_ops = &tun_ethtool_ops;
858         dev->destructor = tun_free_netdev;
859 }
860
861 /* Trivial set of netlink ops to allow deleting tun or tap
862  * device with netlink.
863  */
864 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
865 {
866         return -EINVAL;
867 }
868
869 static struct rtnl_link_ops tun_link_ops __read_mostly = {
870         .kind           = DRV_NAME,
871         .priv_size      = sizeof(struct tun_struct),
872         .setup          = tun_setup,
873         .validate       = tun_validate,
874 };
875
876 static void tun_sock_write_space(struct sock *sk)
877 {
878         struct tun_struct *tun;
879         wait_queue_head_t *wqueue;
880
881         if (!sock_writeable(sk))
882                 return;
883
884         if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
885                 return;
886
887         wqueue = sk_sleep(sk);
888         if (wqueue && waitqueue_active(wqueue))
889                 wake_up_interruptible_sync_poll(wqueue, POLLOUT |
890                                                 POLLWRNORM | POLLWRBAND);
891
892         tun = tun_sk(sk)->tun;
893         kill_fasync(&tun->fasync, SIGIO, POLL_OUT);
894 }
895
896 static void tun_sock_destruct(struct sock *sk)
897 {
898         free_netdev(tun_sk(sk)->tun->dev);
899 }
900
901 static int tun_sendmsg(struct kiocb *iocb, struct socket *sock,
902                        struct msghdr *m, size_t total_len)
903 {
904         struct tun_struct *tun = container_of(sock, struct tun_struct, socket);
905         return tun_get_user(tun, m->msg_iov, total_len,
906                             m->msg_flags & MSG_DONTWAIT);
907 }
908
909 static int tun_recvmsg(struct kiocb *iocb, struct socket *sock,
910                        struct msghdr *m, size_t total_len,
911                        int flags)
912 {
913         struct tun_struct *tun = container_of(sock, struct tun_struct, socket);
914         int ret;
915         if (flags & ~(MSG_DONTWAIT|MSG_TRUNC))
916                 return -EINVAL;
917         ret = tun_do_read(tun, iocb, m->msg_iov, total_len,
918                           flags & MSG_DONTWAIT);
919         if (ret > total_len) {
920                 m->msg_flags |= MSG_TRUNC;
921                 ret = flags & MSG_TRUNC ? ret : total_len;
922         }
923         return ret;
924 }
925
926 /* Ops structure to mimic raw sockets with tun */
927 static const struct proto_ops tun_socket_ops = {
928         .sendmsg = tun_sendmsg,
929         .recvmsg = tun_recvmsg,
930 };
931
932 static struct proto tun_proto = {
933         .name           = "tun",
934         .owner          = THIS_MODULE,
935         .obj_size       = sizeof(struct tun_sock),
936 };
937
938 static int tun_flags(struct tun_struct *tun)
939 {
940         int flags = 0;
941
942         if (tun->flags & TUN_TUN_DEV)
943                 flags |= IFF_TUN;
944         else
945                 flags |= IFF_TAP;
946
947         if (tun->flags & TUN_NO_PI)
948                 flags |= IFF_NO_PI;
949
950         if (tun->flags & TUN_ONE_QUEUE)
951                 flags |= IFF_ONE_QUEUE;
952
953         if (tun->flags & TUN_VNET_HDR)
954                 flags |= IFF_VNET_HDR;
955
956         return flags;
957 }
958
959 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
960                               char *buf)
961 {
962         struct tun_struct *tun = netdev_priv(to_net_dev(dev));
963         return sprintf(buf, "0x%x\n", tun_flags(tun));
964 }
965
966 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
967                               char *buf)
968 {
969         struct tun_struct *tun = netdev_priv(to_net_dev(dev));
970         return sprintf(buf, "%d\n", tun->owner);
971 }
972
973 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
974                               char *buf)
975 {
976         struct tun_struct *tun = netdev_priv(to_net_dev(dev));
977         return sprintf(buf, "%d\n", tun->group);
978 }
979
980 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
981 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
982 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
983
984 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
985 {
986         struct sock *sk;
987         struct tun_struct *tun;
988         struct net_device *dev;
989         int err;
990
991         dev = __dev_get_by_name(net, ifr->ifr_name);
992         if (dev) {
993                 const struct cred *cred = current_cred();
994
995                 if (ifr->ifr_flags & IFF_TUN_EXCL)
996                         return -EBUSY;
997                 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
998                         tun = netdev_priv(dev);
999                 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
1000                         tun = netdev_priv(dev);
1001                 else
1002                         return -EINVAL;
1003
1004                 if (((tun->owner != -1 && cred->euid != tun->owner) ||
1005                      (tun->group != -1 && !in_egroup_p(tun->group))) &&
1006                     !capable(CAP_NET_ADMIN))
1007                         return -EPERM;
1008                 err = security_tun_dev_attach(tun->socket.sk);
1009                 if (err < 0)
1010                         return err;
1011
1012                 err = tun_attach(tun, file);
1013                 if (err < 0)
1014                         return err;
1015         }
1016         else {
1017                 char *name;
1018                 unsigned long flags = 0;
1019
1020                 if (!capable(CAP_NET_ADMIN))
1021                         return -EPERM;
1022                 err = security_tun_dev_create();
1023                 if (err < 0)
1024                         return err;
1025
1026                 /* Set dev type */
1027                 if (ifr->ifr_flags & IFF_TUN) {
1028                         /* TUN device */
1029                         flags |= TUN_TUN_DEV;
1030                         name = "tun%d";
1031                 } else if (ifr->ifr_flags & IFF_TAP) {
1032                         /* TAP device */
1033                         flags |= TUN_TAP_DEV;
1034                         name = "tap%d";
1035                 } else
1036                         return -EINVAL;
1037
1038                 if (*ifr->ifr_name)
1039                         name = ifr->ifr_name;
1040
1041                 dev = alloc_netdev(sizeof(struct tun_struct), name,
1042                                    tun_setup);
1043                 if (!dev)
1044                         return -ENOMEM;
1045
1046                 dev_net_set(dev, net);
1047                 dev->rtnl_link_ops = &tun_link_ops;
1048
1049                 tun = netdev_priv(dev);
1050                 tun->dev = dev;
1051                 tun->flags = flags;
1052                 tun->txflt.count = 0;
1053                 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
1054
1055                 err = -ENOMEM;
1056                 sk = sk_alloc(net, AF_UNSPEC, GFP_KERNEL, &tun_proto);
1057                 if (!sk)
1058                         goto err_free_dev;
1059
1060                 tun->socket.wq = &tun->wq;
1061                 init_waitqueue_head(&tun->wq.wait);
1062                 tun->socket.ops = &tun_socket_ops;
1063                 sock_init_data(&tun->socket, sk);
1064                 sk->sk_write_space = tun_sock_write_space;
1065                 sk->sk_sndbuf = INT_MAX;
1066
1067                 tun_sk(sk)->tun = tun;
1068
1069                 security_tun_dev_post_create(sk);
1070
1071                 tun_net_init(dev);
1072
1073                 if (strchr(dev->name, '%')) {
1074                         err = dev_alloc_name(dev, dev->name);
1075                         if (err < 0)
1076                                 goto err_free_sk;
1077                 }
1078
1079                 err = register_netdevice(tun->dev);
1080                 if (err < 0)
1081                         goto err_free_sk;
1082
1083                 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
1084                     device_create_file(&tun->dev->dev, &dev_attr_owner) ||
1085                     device_create_file(&tun->dev->dev, &dev_attr_group))
1086                         printk(KERN_ERR "Failed to create tun sysfs files\n");
1087
1088                 sk->sk_destruct = tun_sock_destruct;
1089
1090                 err = tun_attach(tun, file);
1091                 if (err < 0)
1092                         goto failed;
1093         }
1094
1095         DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);
1096
1097         if (ifr->ifr_flags & IFF_NO_PI)
1098                 tun->flags |= TUN_NO_PI;
1099         else
1100                 tun->flags &= ~TUN_NO_PI;
1101
1102         if (ifr->ifr_flags & IFF_ONE_QUEUE)
1103                 tun->flags |= TUN_ONE_QUEUE;
1104         else
1105                 tun->flags &= ~TUN_ONE_QUEUE;
1106
1107         if (ifr->ifr_flags & IFF_VNET_HDR)
1108                 tun->flags |= TUN_VNET_HDR;
1109         else
1110                 tun->flags &= ~TUN_VNET_HDR;
1111
1112         /* Make sure persistent devices do not get stuck in
1113          * xoff state.
1114          */
1115         if (netif_running(tun->dev))
1116                 netif_wake_queue(tun->dev);
1117
1118         strcpy(ifr->ifr_name, tun->dev->name);
1119         return 0;
1120
1121  err_free_sk:
1122         sock_put(sk);
1123  err_free_dev:
1124         free_netdev(dev);
1125  failed:
1126         return err;
1127 }
1128
1129 static int tun_get_iff(struct net *net, struct tun_struct *tun,
1130                        struct ifreq *ifr)
1131 {
1132         DBG(KERN_INFO "%s: tun_get_iff\n", tun->dev->name);
1133
1134         strcpy(ifr->ifr_name, tun->dev->name);
1135
1136         ifr->ifr_flags = tun_flags(tun);
1137
1138         return 0;
1139 }
1140
1141 /* This is like a cut-down ethtool ops, except done via tun fd so no
1142  * privs required. */
1143 static int set_offload(struct net_device *dev, unsigned long arg)
1144 {
1145         unsigned int old_features, features;
1146
1147         old_features = dev->features;
1148         /* Unset features, set them as we chew on the arg. */
1149         features = (old_features & ~(NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST
1150                                     |NETIF_F_TSO_ECN|NETIF_F_TSO|NETIF_F_TSO6
1151                                     |NETIF_F_UFO));
1152
1153         if (arg & TUN_F_CSUM) {
1154                 features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1155                 arg &= ~TUN_F_CSUM;
1156
1157                 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1158                         if (arg & TUN_F_TSO_ECN) {
1159                                 features |= NETIF_F_TSO_ECN;
1160                                 arg &= ~TUN_F_TSO_ECN;
1161                         }
1162                         if (arg & TUN_F_TSO4)
1163                                 features |= NETIF_F_TSO;
1164                         if (arg & TUN_F_TSO6)
1165                                 features |= NETIF_F_TSO6;
1166                         arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1167                 }
1168
1169                 if (arg & TUN_F_UFO) {
1170                         features |= NETIF_F_UFO;
1171                         arg &= ~TUN_F_UFO;
1172                 }
1173         }
1174
1175         /* This gives the user a way to test for new features in future by
1176          * trying to set them. */
1177         if (arg)
1178                 return -EINVAL;
1179
1180         dev->features = features;
1181         if (old_features != dev->features)
1182                 netdev_features_change(dev);
1183
1184         return 0;
1185 }
1186
1187 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
1188                             unsigned long arg, int ifreq_len)
1189 {
1190         struct tun_file *tfile = file->private_data;
1191         struct tun_struct *tun;
1192         void __user* argp = (void __user*)arg;
1193         struct sock_fprog fprog;
1194         struct ifreq ifr;
1195         int sndbuf;
1196         int vnet_hdr_sz;
1197         int ret;
1198
1199         if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
1200                 if (copy_from_user(&ifr, argp, ifreq_len))
1201                         return -EFAULT;
1202
1203         if (cmd == TUNGETFEATURES) {
1204                 /* Currently this just means: "what IFF flags are valid?".
1205                  * This is needed because we never checked for invalid flags on
1206                  * TUNSETIFF. */
1207                 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
1208                                 IFF_VNET_HDR,
1209                                 (unsigned int __user*)argp);
1210         }
1211
1212         rtnl_lock();
1213
1214         tun = __tun_get(tfile);
1215         if (cmd == TUNSETIFF && !tun) {
1216                 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1217
1218                 ret = tun_set_iff(tfile->net, file, &ifr);
1219
1220                 if (ret)
1221                         goto unlock;
1222
1223                 if (copy_to_user(argp, &ifr, ifreq_len))
1224                         ret = -EFAULT;
1225                 goto unlock;
1226         }
1227
1228         ret = -EBADFD;
1229         if (!tun)
1230                 goto unlock;
1231
1232         DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd);
1233
1234         ret = 0;
1235         switch (cmd) {
1236         case TUNGETIFF:
1237                 ret = tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1238                 if (ret)
1239                         break;
1240
1241                 if (copy_to_user(argp, &ifr, ifreq_len))
1242                         ret = -EFAULT;
1243                 break;
1244
1245         case TUNSETNOCSUM:
1246                 /* Disable/Enable checksum */
1247                 if (arg)
1248                         tun->flags |= TUN_NOCHECKSUM;
1249                 else
1250                         tun->flags &= ~TUN_NOCHECKSUM;
1251
1252                 DBG(KERN_INFO "%s: checksum %s\n",
1253                     tun->dev->name, arg ? "disabled" : "enabled");
1254                 break;
1255
1256         case TUNSETPERSIST:
1257                 /* Disable/Enable persist mode */
1258                 if (arg)
1259                         tun->flags |= TUN_PERSIST;
1260                 else
1261                         tun->flags &= ~TUN_PERSIST;
1262
1263                 DBG(KERN_INFO "%s: persist %s\n",
1264                     tun->dev->name, arg ? "enabled" : "disabled");
1265                 break;
1266
1267         case TUNSETOWNER:
1268                 /* Set owner of the device */
1269                 tun->owner = (uid_t) arg;
1270
1271                 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner);
1272                 break;
1273
1274         case TUNSETGROUP:
1275                 /* Set group of the device */
1276                 tun->group= (gid_t) arg;
1277
1278                 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group);
1279                 break;
1280
1281         case TUNSETLINK:
1282                 /* Only allow setting the type when the interface is down */
1283                 if (tun->dev->flags & IFF_UP) {
1284                         DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
1285                                 tun->dev->name);
1286                         ret = -EBUSY;
1287                 } else {
1288                         tun->dev->type = (int) arg;
1289                         DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
1290                         ret = 0;
1291                 }
1292                 break;
1293
1294 #ifdef TUN_DEBUG
1295         case TUNSETDEBUG:
1296                 tun->debug = arg;
1297                 break;
1298 #endif
1299         case TUNSETOFFLOAD:
1300                 ret = set_offload(tun->dev, arg);
1301                 break;
1302
1303         case TUNSETTXFILTER:
1304                 /* Can be set only for TAPs */
1305                 ret = -EINVAL;
1306                 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1307                         break;
1308                 ret = update_filter(&tun->txflt, (void __user *)arg);
1309                 break;
1310
1311         case SIOCGIFHWADDR:
1312                 /* Get hw address */
1313                 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
1314                 ifr.ifr_hwaddr.sa_family = tun->dev->type;
1315                 if (copy_to_user(argp, &ifr, ifreq_len))
1316                         ret = -EFAULT;
1317                 break;
1318
1319         case SIOCSIFHWADDR:
1320                 /* Set hw address */
1321                 DBG(KERN_DEBUG "%s: set hw address: %pM\n",
1322                         tun->dev->name, ifr.ifr_hwaddr.sa_data);
1323
1324                 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
1325                 break;
1326
1327         case TUNGETSNDBUF:
1328                 sndbuf = tun->socket.sk->sk_sndbuf;
1329                 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
1330                         ret = -EFAULT;
1331                 break;
1332
1333         case TUNSETSNDBUF:
1334                 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
1335                         ret = -EFAULT;
1336                         break;
1337                 }
1338
1339                 tun->socket.sk->sk_sndbuf = sndbuf;
1340                 break;
1341
1342         case TUNGETVNETHDRSZ:
1343                 vnet_hdr_sz = tun->vnet_hdr_sz;
1344                 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
1345                         ret = -EFAULT;
1346                 break;
1347
1348         case TUNSETVNETHDRSZ:
1349                 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
1350                         ret = -EFAULT;
1351                         break;
1352                 }
1353                 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
1354                         ret = -EINVAL;
1355                         break;
1356                 }
1357
1358                 tun->vnet_hdr_sz = vnet_hdr_sz;
1359                 break;
1360
1361         case TUNATTACHFILTER:
1362                 /* Can be set only for TAPs */
1363                 ret = -EINVAL;
1364                 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1365                         break;
1366                 ret = -EFAULT;
1367                 if (copy_from_user(&fprog, argp, sizeof(fprog)))
1368                         break;
1369
1370                 ret = sk_attach_filter(&fprog, tun->socket.sk);
1371                 break;
1372
1373         case TUNDETACHFILTER:
1374                 /* Can be set only for TAPs */
1375                 ret = -EINVAL;
1376                 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1377                         break;
1378                 ret = sk_detach_filter(tun->socket.sk);
1379                 break;
1380
1381         default:
1382                 ret = -EINVAL;
1383                 break;
1384         }
1385
1386 unlock:
1387         rtnl_unlock();
1388         if (tun)
1389                 tun_put(tun);
1390         return ret;
1391 }
1392
1393 static long tun_chr_ioctl(struct file *file,
1394                           unsigned int cmd, unsigned long arg)
1395 {
1396         return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
1397 }
1398
1399 #ifdef CONFIG_COMPAT
1400 static long tun_chr_compat_ioctl(struct file *file,
1401                          unsigned int cmd, unsigned long arg)
1402 {
1403         switch (cmd) {
1404         case TUNSETIFF:
1405         case TUNGETIFF:
1406         case TUNSETTXFILTER:
1407         case TUNGETSNDBUF:
1408         case TUNSETSNDBUF:
1409         case SIOCGIFHWADDR:
1410         case SIOCSIFHWADDR:
1411                 arg = (unsigned long)compat_ptr(arg);
1412                 break;
1413         default:
1414                 arg = (compat_ulong_t)arg;
1415                 break;
1416         }
1417
1418         /*
1419          * compat_ifreq is shorter than ifreq, so we must not access beyond
1420          * the end of that structure. All fields that are used in this
1421          * driver are compatible though, we don't need to convert the
1422          * contents.
1423          */
1424         return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
1425 }
1426 #endif /* CONFIG_COMPAT */
1427
1428 static int tun_chr_fasync(int fd, struct file *file, int on)
1429 {
1430         struct tun_struct *tun = tun_get(file);
1431         int ret;
1432
1433         if (!tun)
1434                 return -EBADFD;
1435
1436         DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);
1437
1438         if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
1439                 goto out;
1440
1441         if (on) {
1442                 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
1443                 if (ret)
1444                         goto out;
1445                 tun->flags |= TUN_FASYNC;
1446         } else
1447                 tun->flags &= ~TUN_FASYNC;
1448         ret = 0;
1449 out:
1450         tun_put(tun);
1451         return ret;
1452 }
1453
1454 static int tun_chr_open(struct inode *inode, struct file * file)
1455 {
1456         struct tun_file *tfile;
1457
1458         DBG1(KERN_INFO "tunX: tun_chr_open\n");
1459
1460         tfile = kmalloc(sizeof(*tfile), GFP_KERNEL);
1461         if (!tfile)
1462                 return -ENOMEM;
1463         atomic_set(&tfile->count, 0);
1464         tfile->tun = NULL;
1465         tfile->net = get_net(current->nsproxy->net_ns);
1466         file->private_data = tfile;
1467         return 0;
1468 }
1469
1470 static int tun_chr_close(struct inode *inode, struct file *file)
1471 {
1472         struct tun_file *tfile = file->private_data;
1473         struct tun_struct *tun;
1474
1475         tun = __tun_get(tfile);
1476         if (tun) {
1477                 struct net_device *dev = tun->dev;
1478
1479                 DBG(KERN_INFO "%s: tun_chr_close\n", dev->name);
1480
1481                 __tun_detach(tun);
1482
1483                 /* If desirable, unregister the netdevice. */
1484                 if (!(tun->flags & TUN_PERSIST)) {
1485                         rtnl_lock();
1486                         if (dev->reg_state == NETREG_REGISTERED)
1487                                 unregister_netdevice(dev);
1488                         rtnl_unlock();
1489                 }
1490         }
1491
1492         tun = tfile->tun;
1493         if (tun)
1494                 sock_put(tun->socket.sk);
1495
1496         put_net(tfile->net);
1497         kfree(tfile);
1498
1499         return 0;
1500 }
1501
1502 static const struct file_operations tun_fops = {
1503         .owner  = THIS_MODULE,
1504         .llseek = no_llseek,
1505         .read  = do_sync_read,
1506         .aio_read  = tun_chr_aio_read,
1507         .write = do_sync_write,
1508         .aio_write = tun_chr_aio_write,
1509         .poll   = tun_chr_poll,
1510         .unlocked_ioctl = tun_chr_ioctl,
1511 #ifdef CONFIG_COMPAT
1512         .compat_ioctl = tun_chr_compat_ioctl,
1513 #endif
1514         .open   = tun_chr_open,
1515         .release = tun_chr_close,
1516         .fasync = tun_chr_fasync
1517 };
1518
1519 static struct miscdevice tun_miscdev = {
1520         .minor = TUN_MINOR,
1521         .name = "tun",
1522         .nodename = "net/tun",
1523         .fops = &tun_fops,
1524 };
1525
1526 /* ethtool interface */
1527
1528 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1529 {
1530         cmd->supported          = 0;
1531         cmd->advertising        = 0;
1532         cmd->speed              = SPEED_10;
1533         cmd->duplex             = DUPLEX_FULL;
1534         cmd->port               = PORT_TP;
1535         cmd->phy_address        = 0;
1536         cmd->transceiver        = XCVR_INTERNAL;
1537         cmd->autoneg            = AUTONEG_DISABLE;
1538         cmd->maxtxpkt           = 0;
1539         cmd->maxrxpkt           = 0;
1540         return 0;
1541 }
1542
1543 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
1544 {
1545         struct tun_struct *tun = netdev_priv(dev);
1546
1547         strcpy(info->driver, DRV_NAME);
1548         strcpy(info->version, DRV_VERSION);
1549         strcpy(info->fw_version, "N/A");
1550
1551         switch (tun->flags & TUN_TYPE_MASK) {
1552         case TUN_TUN_DEV:
1553                 strcpy(info->bus_info, "tun");
1554                 break;
1555         case TUN_TAP_DEV:
1556                 strcpy(info->bus_info, "tap");
1557                 break;
1558         }
1559 }
1560
1561 static u32 tun_get_msglevel(struct net_device *dev)
1562 {
1563 #ifdef TUN_DEBUG
1564         struct tun_struct *tun = netdev_priv(dev);
1565         return tun->debug;
1566 #else
1567         return -EOPNOTSUPP;
1568 #endif
1569 }
1570
1571 static void tun_set_msglevel(struct net_device *dev, u32 value)
1572 {
1573 #ifdef TUN_DEBUG
1574         struct tun_struct *tun = netdev_priv(dev);
1575         tun->debug = value;
1576 #endif
1577 }
1578
1579 static u32 tun_get_rx_csum(struct net_device *dev)
1580 {
1581         struct tun_struct *tun = netdev_priv(dev);
1582         return (tun->flags & TUN_NOCHECKSUM) == 0;
1583 }
1584
1585 static int tun_set_rx_csum(struct net_device *dev, u32 data)
1586 {
1587         struct tun_struct *tun = netdev_priv(dev);
1588         if (data)
1589                 tun->flags &= ~TUN_NOCHECKSUM;
1590         else
1591                 tun->flags |= TUN_NOCHECKSUM;
1592         return 0;
1593 }
1594
1595 static const struct ethtool_ops tun_ethtool_ops = {
1596         .get_settings   = tun_get_settings,
1597         .get_drvinfo    = tun_get_drvinfo,
1598         .get_msglevel   = tun_get_msglevel,
1599         .set_msglevel   = tun_set_msglevel,
1600         .get_link       = ethtool_op_get_link,
1601         .get_rx_csum    = tun_get_rx_csum,
1602         .set_rx_csum    = tun_set_rx_csum
1603 };
1604
1605
1606 static int __init tun_init(void)
1607 {
1608         int ret = 0;
1609
1610         printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
1611         printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);
1612
1613         ret = rtnl_link_register(&tun_link_ops);
1614         if (ret) {
1615                 printk(KERN_ERR "tun: Can't register link_ops\n");
1616                 goto err_linkops;
1617         }
1618
1619         ret = misc_register(&tun_miscdev);
1620         if (ret) {
1621                 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
1622                 goto err_misc;
1623         }
1624         return  0;
1625 err_misc:
1626         rtnl_link_unregister(&tun_link_ops);
1627 err_linkops:
1628         return ret;
1629 }
1630
1631 static void tun_cleanup(void)
1632 {
1633         misc_deregister(&tun_miscdev);
1634         rtnl_link_unregister(&tun_link_ops);
1635 }
1636
1637 /* Get an underlying socket object from tun file.  Returns error unless file is
1638  * attached to a device.  The returned object works like a packet socket, it
1639  * can be used for sock_sendmsg/sock_recvmsg.  The caller is responsible for
1640  * holding a reference to the file for as long as the socket is in use. */
1641 struct socket *tun_get_socket(struct file *file)
1642 {
1643         struct tun_struct *tun;
1644         if (file->f_op != &tun_fops)
1645                 return ERR_PTR(-EINVAL);
1646         tun = tun_get(file);
1647         if (!tun)
1648                 return ERR_PTR(-EBADFD);
1649         tun_put(tun);
1650         return &tun->socket;
1651 }
1652 EXPORT_SYMBOL_GPL(tun_get_socket);
1653
1654 module_init(tun_init);
1655 module_exit(tun_cleanup);
1656 MODULE_DESCRIPTION(DRV_DESCRIPTION);
1657 MODULE_AUTHOR(DRV_COPYRIGHT);
1658 MODULE_LICENSE("GPL");
1659 MODULE_ALIAS_MISCDEV(TUN_MINOR);
1660 MODULE_ALIAS("devname:net/tun");