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Merge branch 'for-next' into for-linus
[linux-2.6/btrfs-unstable.git] / drivers / net / tun.c
blob96c39bddc78c049e85411f6f298485b531356c78
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
113 #ifdef TUN_DEBUG
114 int debug;
115 #endif
116 };
117
118 struct tun_sock {
119 struct sock sk;
120 struct tun_struct *tun;
121 };
122
123 static inline struct tun_sock *tun_sk(struct sock *sk)
124 {
125 return container_of(sk, struct tun_sock, sk);
126 }
127
128 static int tun_attach(struct tun_struct *tun, struct file *file)
129 {
130 struct tun_file *tfile = file->private_data;
131 int err;
132
133 ASSERT_RTNL();
134
135 netif_tx_lock_bh(tun->dev);
136
137 err = -EINVAL;
138 if (tfile->tun)
139 goto out;
140
141 err = -EBUSY;
142 if (tun->tfile)
143 goto out;
144
145 err = 0;
146 tfile->tun = tun;
147 tun->tfile = tfile;
148 tun->socket.file = file;
149 dev_hold(tun->dev);
150 sock_hold(tun->socket.sk);
151 atomic_inc(&tfile->count);
152
153 out:
154 netif_tx_unlock_bh(tun->dev);
155 return err;
156 }
157
158 static void __tun_detach(struct tun_struct *tun)
159 {
160 /* Detach from net device */
161 netif_tx_lock_bh(tun->dev);
162 tun->tfile = NULL;
163 tun->socket.file = NULL;
164 netif_tx_unlock_bh(tun->dev);
165
166 /* Drop read queue */
167 skb_queue_purge(&tun->socket.sk->sk_receive_queue);
168
169 /* Drop the extra count on the net device */
170 dev_put(tun->dev);
171 }
172
173 static void tun_detach(struct tun_struct *tun)
174 {
175 rtnl_lock();
176 __tun_detach(tun);
177 rtnl_unlock();
178 }
179
180 static struct tun_struct *__tun_get(struct tun_file *tfile)
181 {
182 struct tun_struct *tun = NULL;
183
184 if (atomic_inc_not_zero(&tfile->count))
185 tun = tfile->tun;
186
187 return tun;
188 }
189
190 static struct tun_struct *tun_get(struct file *file)
191 {
192 return __tun_get(file->private_data);
193 }
194
195 static void tun_put(struct tun_struct *tun)
196 {
197 struct tun_file *tfile = tun->tfile;
198
199 if (atomic_dec_and_test(&tfile->count))
200 tun_detach(tfile->tun);
201 }
202
203 /* TAP filterting */
204 static void addr_hash_set(u32 *mask, const u8 *addr)
205 {
206 int n = ether_crc(ETH_ALEN, addr) >> 26;
207 mask[n >> 5] |= (1 << (n & 31));
208 }
209
210 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
211 {
212 int n = ether_crc(ETH_ALEN, addr) >> 26;
213 return mask[n >> 5] & (1 << (n & 31));
214 }
215
216 static int update_filter(struct tap_filter *filter, void __user *arg)
217 {
218 struct { u8 u[ETH_ALEN]; } *addr;
219 struct tun_filter uf;
220 int err, alen, n, nexact;
221
222 if (copy_from_user(&uf, arg, sizeof(uf)))
223 return -EFAULT;
224
225 if (!uf.count) {
226 /* Disabled */
227 filter->count = 0;
228 return 0;
229 }
230
231 alen = ETH_ALEN * uf.count;
232 addr = kmalloc(alen, GFP_KERNEL);
233 if (!addr)
234 return -ENOMEM;
235
236 if (copy_from_user(addr, arg + sizeof(uf), alen)) {
237 err = -EFAULT;
238 goto done;
239 }
240
241 /* The filter is updated without holding any locks. Which is
242 * perfectly safe. We disable it first and in the worst
243 * case we'll accept a few undesired packets. */
244 filter->count = 0;
245 wmb();
246
247 /* Use first set of addresses as an exact filter */
248 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
249 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
250
251 nexact = n;
252
253 /* Remaining multicast addresses are hashed,
254 * unicast will leave the filter disabled. */
255 memset(filter->mask, 0, sizeof(filter->mask));
256 for (; n < uf.count; n++) {
257 if (!is_multicast_ether_addr(addr[n].u)) {
258 err = 0; /* no filter */
259 goto done;
260 }
261 addr_hash_set(filter->mask, addr[n].u);
262 }
263
264 /* For ALLMULTI just set the mask to all ones.
265 * This overrides the mask populated above. */
266 if ((uf.flags & TUN_FLT_ALLMULTI))
267 memset(filter->mask, ~0, sizeof(filter->mask));
268
269 /* Now enable the filter */
270 wmb();
271 filter->count = nexact;
272
273 /* Return the number of exact filters */
274 err = nexact;
275
276 done:
277 kfree(addr);
278 return err;
279 }
280
281 /* Returns: 0 - drop, !=0 - accept */
282 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
283 {
284 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
285 * at this point. */
286 struct ethhdr *eh = (struct ethhdr *) skb->data;
287 int i;
288
289 /* Exact match */
290 for (i = 0; i < filter->count; i++)
291 if (!compare_ether_addr(eh->h_dest, filter->addr[i]))
292 return 1;
293
294 /* Inexact match (multicast only) */
295 if (is_multicast_ether_addr(eh->h_dest))
296 return addr_hash_test(filter->mask, eh->h_dest);
297
298 return 0;
299 }
300
301 /*
302 * Checks whether the packet is accepted or not.
303 * Returns: 0 - drop, !=0 - accept
304 */
305 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
306 {
307 if (!filter->count)
308 return 1;
309
310 return run_filter(filter, skb);
311 }
312
313 /* Network device part of the driver */
314
315 static const struct ethtool_ops tun_ethtool_ops;
316
317 /* Net device detach from fd. */
318 static void tun_net_uninit(struct net_device *dev)
319 {
320 struct tun_struct *tun = netdev_priv(dev);
321 struct tun_file *tfile = tun->tfile;
322
323 /* Inform the methods they need to stop using the dev.
324 */
325 if (tfile) {
326 wake_up_all(&tun->socket.wait);
327 if (atomic_dec_and_test(&tfile->count))
328 __tun_detach(tun);
329 }
330 }
331
332 static void tun_free_netdev(struct net_device *dev)
333 {
334 struct tun_struct *tun = netdev_priv(dev);
335
336 sock_put(tun->socket.sk);
337 }
338
339 /* Net device open. */
340 static int tun_net_open(struct net_device *dev)
341 {
342 netif_start_queue(dev);
343 return 0;
344 }
345
346 /* Net device close. */
347 static int tun_net_close(struct net_device *dev)
348 {
349 netif_stop_queue(dev);
350 return 0;
351 }
352
353 /* Net device start xmit */
354 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
355 {
356 struct tun_struct *tun = netdev_priv(dev);
357
358 DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len);
359
360 /* Drop packet if interface is not attached */
361 if (!tun->tfile)
362 goto drop;
363
364 /* Drop if the filter does not like it.
365 * This is a noop if the filter is disabled.
366 * Filter can be enabled only for the TAP devices. */
367 if (!check_filter(&tun->txflt, skb))
368 goto drop;
369
370 if (tun->socket.sk->sk_filter &&
371 sk_filter(tun->socket.sk, skb))
372 goto drop;
373
374 if (skb_queue_len(&tun->socket.sk->sk_receive_queue) >= dev->tx_queue_len) {
375 if (!(tun->flags & TUN_ONE_QUEUE)) {
376 /* Normal queueing mode. */
377 /* Packet scheduler handles dropping of further packets. */
378 netif_stop_queue(dev);
379
380 /* We won't see all dropped packets individually, so overrun
381 * error is more appropriate. */
382 dev->stats.tx_fifo_errors++;
383 } else {
384 /* Single queue mode.
385 * Driver handles dropping of all packets itself. */
386 goto drop;
387 }
388 }
389
390 /* Enqueue packet */
391 skb_queue_tail(&tun->socket.sk->sk_receive_queue, skb);
392 dev->trans_start = jiffies;
393
394 /* Notify and wake up reader process */
395 if (tun->flags & TUN_FASYNC)
396 kill_fasync(&tun->fasync, SIGIO, POLL_IN);
397 wake_up_interruptible_poll(&tun->socket.wait, POLLIN |
398 POLLRDNORM | POLLRDBAND);
399 return NETDEV_TX_OK;
400
401 drop:
402 dev->stats.tx_dropped++;
403 kfree_skb(skb);
404 return NETDEV_TX_OK;
405 }
406
407 static void tun_net_mclist(struct net_device *dev)
408 {
409 /*
410 * This callback is supposed to deal with mc filter in
411 * _rx_ path and has nothing to do with the _tx_ path.
412 * In rx path we always accept everything userspace gives us.
413 */
414 return;
415 }
416
417 #define MIN_MTU 68
418 #define MAX_MTU 65535
419
420 static int
421 tun_net_change_mtu(struct net_device *dev, int new_mtu)
422 {
423 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
424 return -EINVAL;
425 dev->mtu = new_mtu;
426 return 0;
427 }
428
429 static const struct net_device_ops tun_netdev_ops = {
430 .ndo_uninit = tun_net_uninit,
431 .ndo_open = tun_net_open,
432 .ndo_stop = tun_net_close,
433 .ndo_start_xmit = tun_net_xmit,
434 .ndo_change_mtu = tun_net_change_mtu,
435 };
436
437 static const struct net_device_ops tap_netdev_ops = {
438 .ndo_uninit = tun_net_uninit,
439 .ndo_open = tun_net_open,
440 .ndo_stop = tun_net_close,
441 .ndo_start_xmit = tun_net_xmit,
442 .ndo_change_mtu = tun_net_change_mtu,
443 .ndo_set_multicast_list = tun_net_mclist,
444 .ndo_set_mac_address = eth_mac_addr,
445 .ndo_validate_addr = eth_validate_addr,
446 };
447
448 /* Initialize net device. */
449 static void tun_net_init(struct net_device *dev)
450 {
451 struct tun_struct *tun = netdev_priv(dev);
452
453 switch (tun->flags & TUN_TYPE_MASK) {
454 case TUN_TUN_DEV:
455 dev->netdev_ops = &tun_netdev_ops;
456
457 /* Point-to-Point TUN Device */
458 dev->hard_header_len = 0;
459 dev->addr_len = 0;
460 dev->mtu = 1500;
461
462 /* Zero header length */
463 dev->type = ARPHRD_NONE;
464 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
465 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
466 break;
467
468 case TUN_TAP_DEV:
469 dev->netdev_ops = &tap_netdev_ops;
470 /* Ethernet TAP Device */
471 ether_setup(dev);
472
473 random_ether_addr(dev->dev_addr);
474
475 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
476 break;
477 }
478 }
479
480 /* Character device part */
481
482 /* Poll */
483 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
484 {
485 struct tun_file *tfile = file->private_data;
486 struct tun_struct *tun = __tun_get(tfile);
487 struct sock *sk;
488 unsigned int mask = 0;
489
490 if (!tun)
491 return POLLERR;
492
493 sk = tun->socket.sk;
494
495 DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name);
496
497 poll_wait(file, &tun->socket.wait, wait);
498
499 if (!skb_queue_empty(&sk->sk_receive_queue))
500 mask |= POLLIN | POLLRDNORM;
501
502 if (sock_writeable(sk) ||
503 (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
504 sock_writeable(sk)))
505 mask |= POLLOUT | POLLWRNORM;
506
507 if (tun->dev->reg_state != NETREG_REGISTERED)
508 mask = POLLERR;
509
510 tun_put(tun);
511 return mask;
512 }
513
514 /* prepad is the amount to reserve at front. len is length after that.
515 * linear is a hint as to how much to copy (usually headers). */
516 static inline struct sk_buff *tun_alloc_skb(struct tun_struct *tun,
517 size_t prepad, size_t len,
518 size_t linear, int noblock)
519 {
520 struct sock *sk = tun->socket.sk;
521 struct sk_buff *skb;
522 int err;
523
524 /* Under a page? Don't bother with paged skb. */
525 if (prepad + len < PAGE_SIZE || !linear)
526 linear = len;
527
528 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
529 &err);
530 if (!skb)
531 return ERR_PTR(err);
532
533 skb_reserve(skb, prepad);
534 skb_put(skb, linear);
535 skb->data_len = len - linear;
536 skb->len += len - linear;
537
538 return skb;
539 }
540
541 /* Get packet from user space buffer */
542 static __inline__ ssize_t tun_get_user(struct tun_struct *tun,
543 const struct iovec *iv, size_t count,
544 int noblock)
545 {
546 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
547 struct sk_buff *skb;
548 size_t len = count, align = 0;
549 struct virtio_net_hdr gso = { 0 };
550 int offset = 0;
551
552 if (!(tun->flags & TUN_NO_PI)) {
553 if ((len -= sizeof(pi)) > count)
554 return -EINVAL;
555
556 if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
557 return -EFAULT;
558 offset += sizeof(pi);
559 }
560
561 if (tun->flags & TUN_VNET_HDR) {
562 if ((len -= sizeof(gso)) > count)
563 return -EINVAL;
564
565 if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
566 return -EFAULT;
567
568 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
569 gso.csum_start + gso.csum_offset + 2 > gso.hdr_len)
570 gso.hdr_len = gso.csum_start + gso.csum_offset + 2;
571
572 if (gso.hdr_len > len)
573 return -EINVAL;
574 offset += sizeof(gso);
575 }
576
577 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
578 align = NET_IP_ALIGN;
579 if (unlikely(len < ETH_HLEN ||
580 (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
581 return -EINVAL;
582 }
583
584 skb = tun_alloc_skb(tun, align, len, gso.hdr_len, noblock);
585 if (IS_ERR(skb)) {
586 if (PTR_ERR(skb) != -EAGAIN)
587 tun->dev->stats.rx_dropped++;
588 return PTR_ERR(skb);
589 }
590
591 if (skb_copy_datagram_from_iovec(skb, 0, iv, offset, len)) {
592 tun->dev->stats.rx_dropped++;
593 kfree_skb(skb);
594 return -EFAULT;
595 }
596
597 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
598 if (!skb_partial_csum_set(skb, gso.csum_start,
599 gso.csum_offset)) {
600 tun->dev->stats.rx_frame_errors++;
601 kfree_skb(skb);
602 return -EINVAL;
603 }
604 } else if (tun->flags & TUN_NOCHECKSUM)
605 skb->ip_summed = CHECKSUM_UNNECESSARY;
606
607 switch (tun->flags & TUN_TYPE_MASK) {
608 case TUN_TUN_DEV:
609 if (tun->flags & TUN_NO_PI) {
610 switch (skb->data[0] & 0xf0) {
611 case 0x40:
612 pi.proto = htons(ETH_P_IP);
613 break;
614 case 0x60:
615 pi.proto = htons(ETH_P_IPV6);
616 break;
617 default:
618 tun->dev->stats.rx_dropped++;
619 kfree_skb(skb);
620 return -EINVAL;
621 }
622 }
623
624 skb_reset_mac_header(skb);
625 skb->protocol = pi.proto;
626 skb->dev = tun->dev;
627 break;
628 case TUN_TAP_DEV:
629 skb->protocol = eth_type_trans(skb, tun->dev);
630 break;
631 };
632
633 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
634 pr_debug("GSO!\n");
635 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
636 case VIRTIO_NET_HDR_GSO_TCPV4:
637 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
638 break;
639 case VIRTIO_NET_HDR_GSO_TCPV6:
640 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
641 break;
642 case VIRTIO_NET_HDR_GSO_UDP:
643 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
644 break;
645 default:
646 tun->dev->stats.rx_frame_errors++;
647 kfree_skb(skb);
648 return -EINVAL;
649 }
650
651 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
652 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
653
654 skb_shinfo(skb)->gso_size = gso.gso_size;
655 if (skb_shinfo(skb)->gso_size == 0) {
656 tun->dev->stats.rx_frame_errors++;
657 kfree_skb(skb);
658 return -EINVAL;
659 }
660
661 /* Header must be checked, and gso_segs computed. */
662 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
663 skb_shinfo(skb)->gso_segs = 0;
664 }
665
666 netif_rx_ni(skb);
667
668 tun->dev->stats.rx_packets++;
669 tun->dev->stats.rx_bytes += len;
670
671 return count;
672 }
673
674 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
675 unsigned long count, loff_t pos)
676 {
677 struct file *file = iocb->ki_filp;
678 struct tun_struct *tun = tun_get(file);
679 ssize_t result;
680
681 if (!tun)
682 return -EBADFD;
683
684 DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);
685
686 result = tun_get_user(tun, iv, iov_length(iv, count),
687 file->f_flags & O_NONBLOCK);
688
689 tun_put(tun);
690 return result;
691 }
692
693 /* Put packet to the user space buffer */
694 static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
695 struct sk_buff *skb,
696 const struct iovec *iv, int len)
697 {
698 struct tun_pi pi = { 0, skb->protocol };
699 ssize_t total = 0;
700
701 if (!(tun->flags & TUN_NO_PI)) {
702 if ((len -= sizeof(pi)) < 0)
703 return -EINVAL;
704
705 if (len < skb->len) {
706 /* Packet will be striped */
707 pi.flags |= TUN_PKT_STRIP;
708 }
709
710 if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi)))
711 return -EFAULT;
712 total += sizeof(pi);
713 }
714
715 if (tun->flags & TUN_VNET_HDR) {
716 struct virtio_net_hdr gso = { 0 }; /* no info leak */
717 if ((len -= sizeof(gso)) < 0)
718 return -EINVAL;
719
720 if (skb_is_gso(skb)) {
721 struct skb_shared_info *sinfo = skb_shinfo(skb);
722
723 /* This is a hint as to how much should be linear. */
724 gso.hdr_len = skb_headlen(skb);
725 gso.gso_size = sinfo->gso_size;
726 if (sinfo->gso_type & SKB_GSO_TCPV4)
727 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
728 else if (sinfo->gso_type & SKB_GSO_TCPV6)
729 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
730 else if (sinfo->gso_type & SKB_GSO_UDP)
731 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
732 else
733 BUG();
734 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
735 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
736 } else
737 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
738
739 if (skb->ip_summed == CHECKSUM_PARTIAL) {
740 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
741 gso.csum_start = skb->csum_start - skb_headroom(skb);
742 gso.csum_offset = skb->csum_offset;
743 } /* else everything is zero */
744
745 if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
746 sizeof(gso))))
747 return -EFAULT;
748 total += sizeof(gso);
749 }
750
751 len = min_t(int, skb->len, len);
752
753 skb_copy_datagram_const_iovec(skb, 0, iv, total, len);
754 total += skb->len;
755
756 tun->dev->stats.tx_packets++;
757 tun->dev->stats.tx_bytes += len;
758
759 return total;
760 }
761
762 static ssize_t tun_do_read(struct tun_struct *tun,
763 struct kiocb *iocb, const struct iovec *iv,
764 ssize_t len, int noblock)
765 {
766 DECLARE_WAITQUEUE(wait, current);
767 struct sk_buff *skb;
768 ssize_t ret = 0;
769
770 DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
771
772 add_wait_queue(&tun->socket.wait, &wait);
773 while (len) {
774 current->state = TASK_INTERRUPTIBLE;
775
776 /* Read frames from the queue */
777 if (!(skb=skb_dequeue(&tun->socket.sk->sk_receive_queue))) {
778 if (noblock) {
779 ret = -EAGAIN;
780 break;
781 }
782 if (signal_pending(current)) {
783 ret = -ERESTARTSYS;
784 break;
785 }
786 if (tun->dev->reg_state != NETREG_REGISTERED) {
787 ret = -EIO;
788 break;
789 }
790
791 /* Nothing to read, let's sleep */
792 schedule();
793 continue;
794 }
795 netif_wake_queue(tun->dev);
796
797 ret = tun_put_user(tun, skb, iv, len);
798 kfree_skb(skb);
799 break;
800 }
801
802 current->state = TASK_RUNNING;
803 remove_wait_queue(&tun->socket.wait, &wait);
804
805 return ret;
806 }
807
808 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
809 unsigned long count, loff_t pos)
810 {
811 struct file *file = iocb->ki_filp;
812 struct tun_file *tfile = file->private_data;
813 struct tun_struct *tun = __tun_get(tfile);
814 ssize_t len, ret;
815
816 if (!tun)
817 return -EBADFD;
818 len = iov_length(iv, count);
819 if (len < 0) {
820 ret = -EINVAL;
821 goto out;
822 }
823
824 ret = tun_do_read(tun, iocb, iv, len, file->f_flags & O_NONBLOCK);
825 ret = min_t(ssize_t, ret, len);
826 out:
827 tun_put(tun);
828 return ret;
829 }
830
831 static void tun_setup(struct net_device *dev)
832 {
833 struct tun_struct *tun = netdev_priv(dev);
834
835 tun->owner = -1;
836 tun->group = -1;
837
838 dev->ethtool_ops = &tun_ethtool_ops;
839 dev->destructor = tun_free_netdev;
840 }
841
842 /* Trivial set of netlink ops to allow deleting tun or tap
843 * device with netlink.
844 */
845 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
846 {
847 return -EINVAL;
848 }
849
850 static struct rtnl_link_ops tun_link_ops __read_mostly = {
851 .kind = DRV_NAME,
852 .priv_size = sizeof(struct tun_struct),
853 .setup = tun_setup,
854 .validate = tun_validate,
855 };
856
857 static void tun_sock_write_space(struct sock *sk)
858 {
859 struct tun_struct *tun;
860
861 if (!sock_writeable(sk))
862 return;
863
864 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
865 return;
866
867 if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
868 wake_up_interruptible_sync_poll(sk->sk_sleep, POLLOUT |
869 POLLWRNORM | POLLWRBAND);
870
871 tun = tun_sk(sk)->tun;
872 kill_fasync(&tun->fasync, SIGIO, POLL_OUT);
873 }
874
875 static void tun_sock_destruct(struct sock *sk)
876 {
877 free_netdev(tun_sk(sk)->tun->dev);
878 }
879
880 static int tun_sendmsg(struct kiocb *iocb, struct socket *sock,
881 struct msghdr *m, size_t total_len)
882 {
883 struct tun_struct *tun = container_of(sock, struct tun_struct, socket);
884 return tun_get_user(tun, m->msg_iov, total_len,
885 m->msg_flags & MSG_DONTWAIT);
886 }
887
888 static int tun_recvmsg(struct kiocb *iocb, struct socket *sock,
889 struct msghdr *m, size_t total_len,
890 int flags)
891 {
892 struct tun_struct *tun = container_of(sock, struct tun_struct, socket);
893 int ret;
894 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC))
895 return -EINVAL;
896 ret = tun_do_read(tun, iocb, m->msg_iov, total_len,
897 flags & MSG_DONTWAIT);
898 if (ret > total_len) {
899 m->msg_flags |= MSG_TRUNC;
900 ret = flags & MSG_TRUNC ? ret : total_len;
901 }
902 return ret;
903 }
904
905 /* Ops structure to mimic raw sockets with tun */
906 static const struct proto_ops tun_socket_ops = {
907 .sendmsg = tun_sendmsg,
908 .recvmsg = tun_recvmsg,
909 };
910
911 static struct proto tun_proto = {
912 .name = "tun",
913 .owner = THIS_MODULE,
914 .obj_size = sizeof(struct tun_sock),
915 };
916
917 static int tun_flags(struct tun_struct *tun)
918 {
919 int flags = 0;
920
921 if (tun->flags & TUN_TUN_DEV)
922 flags |= IFF_TUN;
923 else
924 flags |= IFF_TAP;
925
926 if (tun->flags & TUN_NO_PI)
927 flags |= IFF_NO_PI;
928
929 if (tun->flags & TUN_ONE_QUEUE)
930 flags |= IFF_ONE_QUEUE;
931
932 if (tun->flags & TUN_VNET_HDR)
933 flags |= IFF_VNET_HDR;
934
935 return flags;
936 }
937
938 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
939 char *buf)
940 {
941 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
942 return sprintf(buf, "0x%x\n", tun_flags(tun));
943 }
944
945 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
946 char *buf)
947 {
948 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
949 return sprintf(buf, "%d\n", tun->owner);
950 }
951
952 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
953 char *buf)
954 {
955 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
956 return sprintf(buf, "%d\n", tun->group);
957 }
958
959 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
960 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
961 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
962
963 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
964 {
965 struct sock *sk;
966 struct tun_struct *tun;
967 struct net_device *dev;
968 int err;
969
970 dev = __dev_get_by_name(net, ifr->ifr_name);
971 if (dev) {
972 const struct cred *cred = current_cred();
973
974 if (ifr->ifr_flags & IFF_TUN_EXCL)
975 return -EBUSY;
976 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
977 tun = netdev_priv(dev);
978 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
979 tun = netdev_priv(dev);
980 else
981 return -EINVAL;
982
983 if (((tun->owner != -1 && cred->euid != tun->owner) ||
984 (tun->group != -1 && !in_egroup_p(tun->group))) &&
985 !capable(CAP_NET_ADMIN))
986 return -EPERM;
987 err = security_tun_dev_attach(tun->socket.sk);
988 if (err < 0)
989 return err;
990
991 err = tun_attach(tun, file);
992 if (err < 0)
993 return err;
994 }
995 else {
996 char *name;
997 unsigned long flags = 0;
998
999 if (!capable(CAP_NET_ADMIN))
1000 return -EPERM;
1001 err = security_tun_dev_create();
1002 if (err < 0)
1003 return err;
1004
1005 /* Set dev type */
1006 if (ifr->ifr_flags & IFF_TUN) {
1007 /* TUN device */
1008 flags |= TUN_TUN_DEV;
1009 name = "tun%d";
1010 } else if (ifr->ifr_flags & IFF_TAP) {
1011 /* TAP device */
1012 flags |= TUN_TAP_DEV;
1013 name = "tap%d";
1014 } else
1015 return -EINVAL;
1016
1017 if (*ifr->ifr_name)
1018 name = ifr->ifr_name;
1019
1020 dev = alloc_netdev(sizeof(struct tun_struct), name,
1021 tun_setup);
1022 if (!dev)
1023 return -ENOMEM;
1024
1025 dev_net_set(dev, net);
1026 dev->rtnl_link_ops = &tun_link_ops;
1027
1028 tun = netdev_priv(dev);
1029 tun->dev = dev;
1030 tun->flags = flags;
1031 tun->txflt.count = 0;
1032
1033 err = -ENOMEM;
1034 sk = sk_alloc(net, AF_UNSPEC, GFP_KERNEL, &tun_proto);
1035 if (!sk)
1036 goto err_free_dev;
1037
1038 init_waitqueue_head(&tun->socket.wait);
1039 tun->socket.ops = &tun_socket_ops;
1040 sock_init_data(&tun->socket, sk);
1041 sk->sk_write_space = tun_sock_write_space;
1042 sk->sk_sndbuf = INT_MAX;
1043
1044 tun_sk(sk)->tun = tun;
1045
1046 security_tun_dev_post_create(sk);
1047
1048 tun_net_init(dev);
1049
1050 if (strchr(dev->name, '%')) {
1051 err = dev_alloc_name(dev, dev->name);
1052 if (err < 0)
1053 goto err_free_sk;
1054 }
1055
1056 err = register_netdevice(tun->dev);
1057 if (err < 0)
1058 goto err_free_sk;
1059
1060 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
1061 device_create_file(&tun->dev->dev, &dev_attr_owner) ||
1062 device_create_file(&tun->dev->dev, &dev_attr_group))
1063 printk(KERN_ERR "Failed to create tun sysfs files\n");
1064
1065 sk->sk_destruct = tun_sock_destruct;
1066
1067 err = tun_attach(tun, file);
1068 if (err < 0)
1069 goto failed;
1070 }
1071
1072 DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);
1073
1074 if (ifr->ifr_flags & IFF_NO_PI)
1075 tun->flags |= TUN_NO_PI;
1076 else
1077 tun->flags &= ~TUN_NO_PI;
1078
1079 if (ifr->ifr_flags & IFF_ONE_QUEUE)
1080 tun->flags |= TUN_ONE_QUEUE;
1081 else
1082 tun->flags &= ~TUN_ONE_QUEUE;
1083
1084 if (ifr->ifr_flags & IFF_VNET_HDR)
1085 tun->flags |= TUN_VNET_HDR;
1086 else
1087 tun->flags &= ~TUN_VNET_HDR;
1088
1089 /* Make sure persistent devices do not get stuck in
1090 * xoff state.
1091 */
1092 if (netif_running(tun->dev))
1093 netif_wake_queue(tun->dev);
1094
1095 strcpy(ifr->ifr_name, tun->dev->name);
1096 return 0;
1097
1098 err_free_sk:
1099 sock_put(sk);
1100 err_free_dev:
1101 free_netdev(dev);
1102 failed:
1103 return err;
1104 }
1105
1106 static int tun_get_iff(struct net *net, struct tun_struct *tun,
1107 struct ifreq *ifr)
1108 {
1109 DBG(KERN_INFO "%s: tun_get_iff\n", tun->dev->name);
1110
1111 strcpy(ifr->ifr_name, tun->dev->name);
1112
1113 ifr->ifr_flags = tun_flags(tun);
1114
1115 return 0;
1116 }
1117
1118 /* This is like a cut-down ethtool ops, except done via tun fd so no
1119 * privs required. */
1120 static int set_offload(struct net_device *dev, unsigned long arg)
1121 {
1122 unsigned int old_features, features;
1123
1124 old_features = dev->features;
1125 /* Unset features, set them as we chew on the arg. */
1126 features = (old_features & ~(NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST
1127 |NETIF_F_TSO_ECN|NETIF_F_TSO|NETIF_F_TSO6
1128 |NETIF_F_UFO));
1129
1130 if (arg & TUN_F_CSUM) {
1131 features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1132 arg &= ~TUN_F_CSUM;
1133
1134 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1135 if (arg & TUN_F_TSO_ECN) {
1136 features |= NETIF_F_TSO_ECN;
1137 arg &= ~TUN_F_TSO_ECN;
1138 }
1139 if (arg & TUN_F_TSO4)
1140 features |= NETIF_F_TSO;
1141 if (arg & TUN_F_TSO6)
1142 features |= NETIF_F_TSO6;
1143 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1144 }
1145
1146 if (arg & TUN_F_UFO) {
1147 features |= NETIF_F_UFO;
1148 arg &= ~TUN_F_UFO;
1149 }
1150 }
1151
1152 /* This gives the user a way to test for new features in future by
1153 * trying to set them. */
1154 if (arg)
1155 return -EINVAL;
1156
1157 dev->features = features;
1158 if (old_features != dev->features)
1159 netdev_features_change(dev);
1160
1161 return 0;
1162 }
1163
1164 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
1165 unsigned long arg, int ifreq_len)
1166 {
1167 struct tun_file *tfile = file->private_data;
1168 struct tun_struct *tun;
1169 void __user* argp = (void __user*)arg;
1170 struct sock_fprog fprog;
1171 struct ifreq ifr;
1172 int sndbuf;
1173 int ret;
1174
1175 if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
1176 if (copy_from_user(&ifr, argp, ifreq_len))
1177 return -EFAULT;
1178
1179 if (cmd == TUNGETFEATURES) {
1180 /* Currently this just means: "what IFF flags are valid?".
1181 * This is needed because we never checked for invalid flags on
1182 * TUNSETIFF. */
1183 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
1184 IFF_VNET_HDR,
1185 (unsigned int __user*)argp);
1186 }
1187
1188 rtnl_lock();
1189
1190 tun = __tun_get(tfile);
1191 if (cmd == TUNSETIFF && !tun) {
1192 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1193
1194 ret = tun_set_iff(tfile->net, file, &ifr);
1195
1196 if (ret)
1197 goto unlock;
1198
1199 if (copy_to_user(argp, &ifr, ifreq_len))
1200 ret = -EFAULT;
1201 goto unlock;
1202 }
1203
1204 ret = -EBADFD;
1205 if (!tun)
1206 goto unlock;
1207
1208 DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd);
1209
1210 ret = 0;
1211 switch (cmd) {
1212 case TUNGETIFF:
1213 ret = tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1214 if (ret)
1215 break;
1216
1217 if (copy_to_user(argp, &ifr, ifreq_len))
1218 ret = -EFAULT;
1219 break;
1220
1221 case TUNSETNOCSUM:
1222 /* Disable/Enable checksum */
1223 if (arg)
1224 tun->flags |= TUN_NOCHECKSUM;
1225 else
1226 tun->flags &= ~TUN_NOCHECKSUM;
1227
1228 DBG(KERN_INFO "%s: checksum %s\n",
1229 tun->dev->name, arg ? "disabled" : "enabled");
1230 break;
1231
1232 case TUNSETPERSIST:
1233 /* Disable/Enable persist mode */
1234 if (arg)
1235 tun->flags |= TUN_PERSIST;
1236 else
1237 tun->flags &= ~TUN_PERSIST;
1238
1239 DBG(KERN_INFO "%s: persist %s\n",
1240 tun->dev->name, arg ? "enabled" : "disabled");
1241 break;
1242
1243 case TUNSETOWNER:
1244 /* Set owner of the device */
1245 tun->owner = (uid_t) arg;
1246
1247 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner);
1248 break;
1249
1250 case TUNSETGROUP:
1251 /* Set group of the device */
1252 tun->group= (gid_t) arg;
1253
1254 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group);
1255 break;
1256
1257 case TUNSETLINK:
1258 /* Only allow setting the type when the interface is down */
1259 if (tun->dev->flags & IFF_UP) {
1260 DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
1261 tun->dev->name);
1262 ret = -EBUSY;
1263 } else {
1264 tun->dev->type = (int) arg;
1265 DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
1266 ret = 0;
1267 }
1268 break;
1269
1270 #ifdef TUN_DEBUG
1271 case TUNSETDEBUG:
1272 tun->debug = arg;
1273 break;
1274 #endif
1275 case TUNSETOFFLOAD:
1276 ret = set_offload(tun->dev, arg);
1277 break;
1278
1279 case TUNSETTXFILTER:
1280 /* Can be set only for TAPs */
1281 ret = -EINVAL;
1282 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1283 break;
1284 ret = update_filter(&tun->txflt, (void __user *)arg);
1285 break;
1286
1287 case SIOCGIFHWADDR:
1288 /* Get hw addres */
1289 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
1290 ifr.ifr_hwaddr.sa_family = tun->dev->type;
1291 if (copy_to_user(argp, &ifr, ifreq_len))
1292 ret = -EFAULT;
1293 break;
1294
1295 case SIOCSIFHWADDR:
1296 /* Set hw address */
1297 DBG(KERN_DEBUG "%s: set hw address: %pM\n",
1298 tun->dev->name, ifr.ifr_hwaddr.sa_data);
1299
1300 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
1301 break;
1302
1303 case TUNGETSNDBUF:
1304 sndbuf = tun->socket.sk->sk_sndbuf;
1305 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
1306 ret = -EFAULT;
1307 break;
1308
1309 case TUNSETSNDBUF:
1310 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
1311 ret = -EFAULT;
1312 break;
1313 }
1314
1315 tun->socket.sk->sk_sndbuf = sndbuf;
1316 break;
1317
1318 case TUNATTACHFILTER:
1319 /* Can be set only for TAPs */
1320 ret = -EINVAL;
1321 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1322 break;
1323 ret = -EFAULT;
1324 if (copy_from_user(&fprog, argp, sizeof(fprog)))
1325 break;
1326
1327 ret = sk_attach_filter(&fprog, tun->socket.sk);
1328 break;
1329
1330 case TUNDETACHFILTER:
1331 /* Can be set only for TAPs */
1332 ret = -EINVAL;
1333 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1334 break;
1335 ret = sk_detach_filter(tun->socket.sk);
1336 break;
1337
1338 default:
1339 ret = -EINVAL;
1340 break;
1341 };
1342
1343 unlock:
1344 rtnl_unlock();
1345 if (tun)
1346 tun_put(tun);
1347 return ret;
1348 }
1349
1350 static long tun_chr_ioctl(struct file *file,
1351 unsigned int cmd, unsigned long arg)
1352 {
1353 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
1354 }
1355
1356 #ifdef CONFIG_COMPAT
1357 static long tun_chr_compat_ioctl(struct file *file,
1358 unsigned int cmd, unsigned long arg)
1359 {
1360 switch (cmd) {
1361 case TUNSETIFF:
1362 case TUNGETIFF:
1363 case TUNSETTXFILTER:
1364 case TUNGETSNDBUF:
1365 case TUNSETSNDBUF:
1366 case SIOCGIFHWADDR:
1367 case SIOCSIFHWADDR:
1368 arg = (unsigned long)compat_ptr(arg);
1369 break;
1370 default:
1371 arg = (compat_ulong_t)arg;
1372 break;
1373 }
1374
1375 /*
1376 * compat_ifreq is shorter than ifreq, so we must not access beyond
1377 * the end of that structure. All fields that are used in this
1378 * driver are compatible though, we don't need to convert the
1379 * contents.
1380 */
1381 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
1382 }
1383 #endif /* CONFIG_COMPAT */
1384
1385 static int tun_chr_fasync(int fd, struct file *file, int on)
1386 {
1387 struct tun_struct *tun = tun_get(file);
1388 int ret;
1389
1390 if (!tun)
1391 return -EBADFD;
1392
1393 DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);
1394
1395 if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
1396 goto out;
1397
1398 if (on) {
1399 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
1400 if (ret)
1401 goto out;
1402 tun->flags |= TUN_FASYNC;
1403 } else
1404 tun->flags &= ~TUN_FASYNC;
1405 ret = 0;
1406 out:
1407 tun_put(tun);
1408 return ret;
1409 }
1410
1411 static int tun_chr_open(struct inode *inode, struct file * file)
1412 {
1413 struct tun_file *tfile;
1414
1415 DBG1(KERN_INFO "tunX: tun_chr_open\n");
1416
1417 tfile = kmalloc(sizeof(*tfile), GFP_KERNEL);
1418 if (!tfile)
1419 return -ENOMEM;
1420 atomic_set(&tfile->count, 0);
1421 tfile->tun = NULL;
1422 tfile->net = get_net(current->nsproxy->net_ns);
1423 file->private_data = tfile;
1424 return 0;
1425 }
1426
1427 static int tun_chr_close(struct inode *inode, struct file *file)
1428 {
1429 struct tun_file *tfile = file->private_data;
1430 struct tun_struct *tun;
1431
1432 tun = __tun_get(tfile);
1433 if (tun) {
1434 struct net_device *dev = tun->dev;
1435
1436 DBG(KERN_INFO "%s: tun_chr_close\n", dev->name);
1437
1438 __tun_detach(tun);
1439
1440 /* If desirable, unregister the netdevice. */
1441 if (!(tun->flags & TUN_PERSIST)) {
1442 rtnl_lock();
1443 if (dev->reg_state == NETREG_REGISTERED)
1444 unregister_netdevice(dev);
1445 rtnl_unlock();
1446 }
1447 }
1448
1449 tun = tfile->tun;
1450 if (tun)
1451 sock_put(tun->socket.sk);
1452
1453 put_net(tfile->net);
1454 kfree(tfile);
1455
1456 return 0;
1457 }
1458
1459 static const struct file_operations tun_fops = {
1460 .owner = THIS_MODULE,
1461 .llseek = no_llseek,
1462 .read = do_sync_read,
1463 .aio_read = tun_chr_aio_read,
1464 .write = do_sync_write,
1465 .aio_write = tun_chr_aio_write,
1466 .poll = tun_chr_poll,
1467 .unlocked_ioctl = tun_chr_ioctl,
1468 #ifdef CONFIG_COMPAT
1469 .compat_ioctl = tun_chr_compat_ioctl,
1470 #endif
1471 .open = tun_chr_open,
1472 .release = tun_chr_close,
1473 .fasync = tun_chr_fasync
1474 };
1475
1476 static struct miscdevice tun_miscdev = {
1477 .minor = TUN_MINOR,
1478 .name = "tun",
1479 .nodename = "net/tun",
1480 .fops = &tun_fops,
1481 };
1482
1483 /* ethtool interface */
1484
1485 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1486 {
1487 cmd->supported = 0;
1488 cmd->advertising = 0;
1489 cmd->speed = SPEED_10;
1490 cmd->duplex = DUPLEX_FULL;
1491 cmd->port = PORT_TP;
1492 cmd->phy_address = 0;
1493 cmd->transceiver = XCVR_INTERNAL;
1494 cmd->autoneg = AUTONEG_DISABLE;
1495 cmd->maxtxpkt = 0;
1496 cmd->maxrxpkt = 0;
1497 return 0;
1498 }
1499
1500 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
1501 {
1502 struct tun_struct *tun = netdev_priv(dev);
1503
1504 strcpy(info->driver, DRV_NAME);
1505 strcpy(info->version, DRV_VERSION);
1506 strcpy(info->fw_version, "N/A");
1507
1508 switch (tun->flags & TUN_TYPE_MASK) {
1509 case TUN_TUN_DEV:
1510 strcpy(info->bus_info, "tun");
1511 break;
1512 case TUN_TAP_DEV:
1513 strcpy(info->bus_info, "tap");
1514 break;
1515 }
1516 }
1517
1518 static u32 tun_get_msglevel(struct net_device *dev)
1519 {
1520 #ifdef TUN_DEBUG
1521 struct tun_struct *tun = netdev_priv(dev);
1522 return tun->debug;
1523 #else
1524 return -EOPNOTSUPP;
1525 #endif
1526 }
1527
1528 static void tun_set_msglevel(struct net_device *dev, u32 value)
1529 {
1530 #ifdef TUN_DEBUG
1531 struct tun_struct *tun = netdev_priv(dev);
1532 tun->debug = value;
1533 #endif
1534 }
1535
1536 static u32 tun_get_link(struct net_device *dev)
1537 {
1538 struct tun_struct *tun = netdev_priv(dev);
1539 return !!tun->tfile;
1540 }
1541
1542 static u32 tun_get_rx_csum(struct net_device *dev)
1543 {
1544 struct tun_struct *tun = netdev_priv(dev);
1545 return (tun->flags & TUN_NOCHECKSUM) == 0;
1546 }
1547
1548 static int tun_set_rx_csum(struct net_device *dev, u32 data)
1549 {
1550 struct tun_struct *tun = netdev_priv(dev);
1551 if (data)
1552 tun->flags &= ~TUN_NOCHECKSUM;
1553 else
1554 tun->flags |= TUN_NOCHECKSUM;
1555 return 0;
1556 }
1557
1558 static const struct ethtool_ops tun_ethtool_ops = {
1559 .get_settings = tun_get_settings,
1560 .get_drvinfo = tun_get_drvinfo,
1561 .get_msglevel = tun_get_msglevel,
1562 .set_msglevel = tun_set_msglevel,
1563 .get_link = tun_get_link,
1564 .get_rx_csum = tun_get_rx_csum,
1565 .set_rx_csum = tun_set_rx_csum
1566 };
1567
1568
1569 static int __init tun_init(void)
1570 {
1571 int ret = 0;
1572
1573 printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
1574 printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);
1575
1576 ret = rtnl_link_register(&tun_link_ops);
1577 if (ret) {
1578 printk(KERN_ERR "tun: Can't register link_ops\n");
1579 goto err_linkops;
1580 }
1581
1582 ret = misc_register(&tun_miscdev);
1583 if (ret) {
1584 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
1585 goto err_misc;
1586 }
1587 return 0;
1588 err_misc:
1589 rtnl_link_unregister(&tun_link_ops);
1590 err_linkops:
1591 return ret;
1592 }
1593
1594 static void tun_cleanup(void)
1595 {
1596 misc_deregister(&tun_miscdev);
1597 rtnl_link_unregister(&tun_link_ops);
1598 }
1599
1600 /* Get an underlying socket object from tun file. Returns error unless file is
1601 * attached to a device. The returned object works like a packet socket, it
1602 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
1603 * holding a reference to the file for as long as the socket is in use. */
1604 struct socket *tun_get_socket(struct file *file)
1605 {
1606 struct tun_struct *tun;
1607 if (file->f_op != &tun_fops)
1608 return ERR_PTR(-EINVAL);
1609 tun = tun_get(file);
1610 if (!tun)
1611 return ERR_PTR(-EBADFD);
1612 tun_put(tun);
1613 return &tun->socket;
1614 }
1615 EXPORT_SYMBOL_GPL(tun_get_socket);
1616
1617 module_init(tun_init);
1618 module_exit(tun_cleanup);
1619 MODULE_DESCRIPTION(DRV_DESCRIPTION);
1620 MODULE_AUTHOR(DRV_COPYRIGHT);
1621 MODULE_LICENSE("GPL");
1622 MODULE_ALIAS_MISCDEV(TUN_MINOR);
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