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