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