?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
[linux-btrfs-devel.git] / drivers / net / tun.c
blob7bea9c65119e339326155c45e4af6e268bda0c6c
1 /*
2 * TUN - Universal TUN/TAP device driver.
3 * Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * $Id: tun.c,v 1.15 2002/03/01 02:44:24 maxk Exp $
16 */
17
18 /*
19 * Changes:
20 *
21 * Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14
22 * Add TUNSETLINK ioctl to set the link encapsulation
23 *
24 * Mark Smith <markzzzsmith@yahoo.com.au>
25 * Use random_ether_addr() for tap MAC address.
26 *
27 * Harald Roelle <harald.roelle@ifi.lmu.de> 2004/04/20
28 * Fixes in packet dropping, queue length setting and queue wakeup.
29 * Increased default tx queue length.
30 * Added ethtool API.
31 * Minor cleanups
32 *
33 * Daniel Podlejski <underley@underley.eu.org>
34 * Modifications for 2.3.99-pre5 kernel.
35 */
36
37 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
38
39 #define DRV_NAME "tun"
40 #define DRV_VERSION "1.6"
41 #define DRV_DESCRIPTION "Universal TUN/TAP device driver"
42 #define DRV_COPYRIGHT "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>"
43
44 #include <linux/module.h>
45 #include <linux/errno.h>
46 #include <linux/kernel.h>
47 #include <linux/major.h>
48 #include <linux/slab.h>
49 #include <linux/poll.h>
50 #include <linux/fcntl.h>
51 #include <linux/init.h>
52 #include <linux/skbuff.h>
53 #include <linux/netdevice.h>
54 #include <linux/etherdevice.h>
55 #include <linux/miscdevice.h>
56 #include <linux/ethtool.h>
57 #include <linux/rtnetlink.h>
58 #include <linux/compat.h>
59 #include <linux/if.h>
60 #include <linux/if_arp.h>
61 #include <linux/if_ether.h>
62 #include <linux/if_tun.h>
63 #include <linux/crc32.h>
64 #include <linux/nsproxy.h>
65 #include <linux/virtio_net.h>
66 #include <linux/rcupdate.h>
67 #include <net/net_namespace.h>
68 #include <net/netns/generic.h>
69 #include <net/rtnetlink.h>
70 #include <net/sock.h>
71
72 #include <asm/system.h>
73 #include <asm/uaccess.h>
74
75 /* Uncomment to enable debugging */
76 /* #define TUN_DEBUG 1 */
77
78 #ifdef TUN_DEBUG
79 static int debug;
80
81 #define tun_debug(level, tun, fmt, args...) \
82 do { \
83 if (tun->debug) \
84 netdev_printk(level, tun->dev, fmt, ##args); \
85 } while (0)
86 #define DBG1(level, fmt, args...) \
87 do { \
88 if (debug == 2) \
89 printk(level fmt, ##args); \
90 } while (0)
91 #else
92 #define tun_debug(level, tun, fmt, args...) \
93 do { \
94 if (0) \
95 netdev_printk(level, tun->dev, fmt, ##args); \
96 } while (0)
97 #define DBG1(level, fmt, args...) \
98 do { \
99 if (0) \
100 printk(level fmt, ##args); \
101 } while (0)
102 #endif
103
104 #define FLT_EXACT_COUNT 8
105 struct tap_filter {
106 unsigned int count; /* Number of addrs. Zero means disabled */
107 u32 mask[2]; /* Mask of the hashed addrs */
108 unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN];
109 };
110
111 struct tun_file {
112 atomic_t count;
113 struct tun_struct *tun;
114 struct net *net;
115 };
116
117 struct tun_sock;
118
119 struct tun_struct {
120 struct tun_file *tfile;
121 unsigned int flags;
122 uid_t owner;
123 gid_t group;
124
125 struct net_device *dev;
126 u32 set_features;
127 #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \
128 NETIF_F_TSO6|NETIF_F_UFO)
129 struct fasync_struct *fasync;
130
131 struct tap_filter txflt;
132 struct socket socket;
133 struct socket_wq wq;
134
135 int vnet_hdr_sz;
136
137 #ifdef TUN_DEBUG
138 int debug;
139 #endif
140 };
141
142 struct tun_sock {
143 struct sock sk;
144 struct tun_struct *tun;
145 };
146
147 static inline struct tun_sock *tun_sk(struct sock *sk)
148 {
149 return container_of(sk, struct tun_sock, sk);
150 }
151
152 static int tun_attach(struct tun_struct *tun, struct file *file)
153 {
154 struct tun_file *tfile = file->private_data;
155 int err;
156
157 ASSERT_RTNL();
158
159 netif_tx_lock_bh(tun->dev);
160
161 err = -EINVAL;
162 if (tfile->tun)
163 goto out;
164
165 err = -EBUSY;
166 if (tun->tfile)
167 goto out;
168
169 err = 0;
170 tfile->tun = tun;
171 tun->tfile = tfile;
172 tun->socket.file = file;
173 netif_carrier_on(tun->dev);
174 dev_hold(tun->dev);
175 sock_hold(tun->socket.sk);
176 atomic_inc(&tfile->count);
177
178 out:
179 netif_tx_unlock_bh(tun->dev);
180 return err;
181 }
182
183 static void __tun_detach(struct tun_struct *tun)
184 {
185 /* Detach from net device */
186 netif_tx_lock_bh(tun->dev);
187 netif_carrier_off(tun->dev);
188 tun->tfile = NULL;
189 tun->socket.file = NULL;
190 netif_tx_unlock_bh(tun->dev);
191
192 /* Drop read queue */
193 skb_queue_purge(&tun->socket.sk->sk_receive_queue);
194
195 /* Drop the extra count on the net device */
196 dev_put(tun->dev);
197 }
198
199 static void tun_detach(struct tun_struct *tun)
200 {
201 rtnl_lock();
202 __tun_detach(tun);
203 rtnl_unlock();
204 }
205
206 static struct tun_struct *__tun_get(struct tun_file *tfile)
207 {
208 struct tun_struct *tun = NULL;
209
210 if (atomic_inc_not_zero(&tfile->count))
211 tun = tfile->tun;
212
213 return tun;
214 }
215
216 static struct tun_struct *tun_get(struct file *file)
217 {
218 return __tun_get(file->private_data);
219 }
220
221 static void tun_put(struct tun_struct *tun)
222 {
223 struct tun_file *tfile = tun->tfile;
224
225 if (atomic_dec_and_test(&tfile->count))
226 tun_detach(tfile->tun);
227 }
228
229 /* TAP filtering */
230 static void addr_hash_set(u32 *mask, const u8 *addr)
231 {
232 int n = ether_crc(ETH_ALEN, addr) >> 26;
233 mask[n >> 5] |= (1 << (n & 31));
234 }
235
236 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
237 {
238 int n = ether_crc(ETH_ALEN, addr) >> 26;
239 return mask[n >> 5] & (1 << (n & 31));
240 }
241
242 static int update_filter(struct tap_filter *filter, void __user *arg)
243 {
244 struct { u8 u[ETH_ALEN]; } *addr;
245 struct tun_filter uf;
246 int err, alen, n, nexact;
247
248 if (copy_from_user(&uf, arg, sizeof(uf)))
249 return -EFAULT;
250
251 if (!uf.count) {
252 /* Disabled */
253 filter->count = 0;
254 return 0;
255 }
256
257 alen = ETH_ALEN * uf.count;
258 addr = kmalloc(alen, GFP_KERNEL);
259 if (!addr)
260 return -ENOMEM;
261
262 if (copy_from_user(addr, arg + sizeof(uf), alen)) {
263 err = -EFAULT;
264 goto done;
265 }
266
267 /* The filter is updated without holding any locks. Which is
268 * perfectly safe. We disable it first and in the worst
269 * case we'll accept a few undesired packets. */
270 filter->count = 0;
271 wmb();
272
273 /* Use first set of addresses as an exact filter */
274 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
275 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
276
277 nexact = n;
278
279 /* Remaining multicast addresses are hashed,
280 * unicast will leave the filter disabled. */
281 memset(filter->mask, 0, sizeof(filter->mask));
282 for (; n < uf.count; n++) {
283 if (!is_multicast_ether_addr(addr[n].u)) {
284 err = 0; /* no filter */
285 goto done;
286 }
287 addr_hash_set(filter->mask, addr[n].u);
288 }
289
290 /* For ALLMULTI just set the mask to all ones.
291 * This overrides the mask populated above. */
292 if ((uf.flags & TUN_FLT_ALLMULTI))
293 memset(filter->mask, ~0, sizeof(filter->mask));
294
295 /* Now enable the filter */
296 wmb();
297 filter->count = nexact;
298
299 /* Return the number of exact filters */
300 err = nexact;
301
302 done:
303 kfree(addr);
304 return err;
305 }
306
307 /* Returns: 0 - drop, !=0 - accept */
308 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
309 {
310 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
311 * at this point. */
312 struct ethhdr *eh = (struct ethhdr *) skb->data;
313 int i;
314
315 /* Exact match */
316 for (i = 0; i < filter->count; i++)
317 if (!compare_ether_addr(eh->h_dest, filter->addr[i]))
318 return 1;
319
320 /* Inexact match (multicast only) */
321 if (is_multicast_ether_addr(eh->h_dest))
322 return addr_hash_test(filter->mask, eh->h_dest);
323
324 return 0;
325 }
326
327 /*
328 * Checks whether the packet is accepted or not.
329 * Returns: 0 - drop, !=0 - accept
330 */
331 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
332 {
333 if (!filter->count)
334 return 1;
335
336 return run_filter(filter, skb);
337 }
338
339 /* Network device part of the driver */
340
341 static const struct ethtool_ops tun_ethtool_ops;
342
343 /* Net device detach from fd. */
344 static void tun_net_uninit(struct net_device *dev)
345 {
346 struct tun_struct *tun = netdev_priv(dev);
347 struct tun_file *tfile = tun->tfile;
348
349 /* Inform the methods they need to stop using the dev.
350 */
351 if (tfile) {
352 wake_up_all(&tun->wq.wait);
353 if (atomic_dec_and_test(&tfile->count))
354 __tun_detach(tun);
355 }
356 }
357
358 static void tun_free_netdev(struct net_device *dev)
359 {
360 struct tun_struct *tun = netdev_priv(dev);
361
362 sock_put(tun->socket.sk);
363 }
364
365 /* Net device open. */
366 static int tun_net_open(struct net_device *dev)
367 {
368 netif_start_queue(dev);
369 return 0;
370 }
371
372 /* Net device close. */
373 static int tun_net_close(struct net_device *dev)
374 {
375 netif_stop_queue(dev);
376 return 0;
377 }
378
379 /* Net device start xmit */
380 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
381 {
382 struct tun_struct *tun = netdev_priv(dev);
383
384 tun_debug(KERN_INFO, tun, "tun_net_xmit %d\n", skb->len);
385
386 /* Drop packet if interface is not attached */
387 if (!tun->tfile)
388 goto drop;
389
390 /* Drop if the filter does not like it.
391 * This is a noop if the filter is disabled.
392 * Filter can be enabled only for the TAP devices. */
393 if (!check_filter(&tun->txflt, skb))
394 goto drop;
395
396 if (tun->socket.sk->sk_filter &&
397 sk_filter(tun->socket.sk, skb))
398 goto drop;
399
400 if (skb_queue_len(&tun->socket.sk->sk_receive_queue) >= dev->tx_queue_len) {
401 if (!(tun->flags & TUN_ONE_QUEUE)) {
402 /* Normal queueing mode. */
403 /* Packet scheduler handles dropping of further packets. */
404 netif_stop_queue(dev);
405
406 /* We won't see all dropped packets individually, so overrun
407 * error is more appropriate. */
408 dev->stats.tx_fifo_errors++;
409 } else {
410 /* Single queue mode.
411 * Driver handles dropping of all packets itself. */
412 goto drop;
413 }
414 }
415
416 /* Orphan the skb - required as we might hang on to it
417 * for indefinite time. */
418 skb_orphan(skb);
419
420 /* Enqueue packet */
421 skb_queue_tail(&tun->socket.sk->sk_receive_queue, skb);
422
423 /* Notify and wake up reader process */
424 if (tun->flags & TUN_FASYNC)
425 kill_fasync(&tun->fasync, SIGIO, POLL_IN);
426 wake_up_interruptible_poll(&tun->wq.wait, POLLIN |
427 POLLRDNORM | POLLRDBAND);
428 return NETDEV_TX_OK;
429
430 drop:
431 dev->stats.tx_dropped++;
432 kfree_skb(skb);
433 return NETDEV_TX_OK;
434 }
435
436 static void tun_net_mclist(struct net_device *dev)
437 {
438 /*
439 * This callback is supposed to deal with mc filter in
440 * _rx_ path and has nothing to do with the _tx_ path.
441 * In rx path we always accept everything userspace gives us.
442 */
443 }
444
445 #define MIN_MTU 68
446 #define MAX_MTU 65535
447
448 static int
449 tun_net_change_mtu(struct net_device *dev, int new_mtu)
450 {
451 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
452 return -EINVAL;
453 dev->mtu = new_mtu;
454 return 0;
455 }
456
457 static u32 tun_net_fix_features(struct net_device *dev, u32 features)
458 {
459 struct tun_struct *tun = netdev_priv(dev);
460
461 return (features & tun->set_features) | (features & ~TUN_USER_FEATURES);
462 }
463 #ifdef CONFIG_NET_POLL_CONTROLLER
464 static void tun_poll_controller(struct net_device *dev)
465 {
466 /*
467 * Tun only receives frames when:
468 * 1) the char device endpoint gets data from user space
469 * 2) the tun socket gets a sendmsg call from user space
470 * Since both of those are syncronous operations, we are guaranteed
471 * never to have pending data when we poll for it
472 * so theres nothing to do here but return.
473 * We need this though so netpoll recognizes us as an interface that
474 * supports polling, which enables bridge devices in virt setups to
475 * still use netconsole
476 */
477 return;
478 }
479 #endif
480 static const struct net_device_ops tun_netdev_ops = {
481 .ndo_uninit = tun_net_uninit,
482 .ndo_open = tun_net_open,
483 .ndo_stop = tun_net_close,
484 .ndo_start_xmit = tun_net_xmit,
485 .ndo_change_mtu = tun_net_change_mtu,
486 .ndo_fix_features = tun_net_fix_features,
487 #ifdef CONFIG_NET_POLL_CONTROLLER
488 .ndo_poll_controller = tun_poll_controller,
489 #endif
490 };
491
492 static const struct net_device_ops tap_netdev_ops = {
493 .ndo_uninit = tun_net_uninit,
494 .ndo_open = tun_net_open,
495 .ndo_stop = tun_net_close,
496 .ndo_start_xmit = tun_net_xmit,
497 .ndo_change_mtu = tun_net_change_mtu,
498 .ndo_fix_features = tun_net_fix_features,
499 .ndo_set_rx_mode = tun_net_mclist,
500 .ndo_set_mac_address = eth_mac_addr,
501 .ndo_validate_addr = eth_validate_addr,
502 #ifdef CONFIG_NET_POLL_CONTROLLER
503 .ndo_poll_controller = tun_poll_controller,
504 #endif
505 };
506
507 /* Initialize net device. */
508 static void tun_net_init(struct net_device *dev)
509 {
510 struct tun_struct *tun = netdev_priv(dev);
511
512 switch (tun->flags & TUN_TYPE_MASK) {
513 case TUN_TUN_DEV:
514 dev->netdev_ops = &tun_netdev_ops;
515
516 /* Point-to-Point TUN Device */
517 dev->hard_header_len = 0;
518 dev->addr_len = 0;
519 dev->mtu = 1500;
520
521 /* Zero header length */
522 dev->type = ARPHRD_NONE;
523 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
524 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
525 break;
526
527 case TUN_TAP_DEV:
528 dev->netdev_ops = &tap_netdev_ops;
529 /* Ethernet TAP Device */
530 ether_setup(dev);
531 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
532
533 random_ether_addr(dev->dev_addr);
534
535 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
536 break;
537 }
538 }
539
540 /* Character device part */
541
542 /* Poll */
543 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
544 {
545 struct tun_file *tfile = file->private_data;
546 struct tun_struct *tun = __tun_get(tfile);
547 struct sock *sk;
548 unsigned int mask = 0;
549
550 if (!tun)
551 return POLLERR;
552
553 sk = tun->socket.sk;
554
555 tun_debug(KERN_INFO, tun, "tun_chr_poll\n");
556
557 poll_wait(file, &tun->wq.wait, wait);
558
559 if (!skb_queue_empty(&sk->sk_receive_queue))
560 mask |= POLLIN | POLLRDNORM;
561
562 if (sock_writeable(sk) ||
563 (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
564 sock_writeable(sk)))
565 mask |= POLLOUT | POLLWRNORM;
566
567 if (tun->dev->reg_state != NETREG_REGISTERED)
568 mask = POLLERR;
569
570 tun_put(tun);
571 return mask;
572 }
573
574 /* prepad is the amount to reserve at front. len is length after that.
575 * linear is a hint as to how much to copy (usually headers). */
576 static struct sk_buff *tun_alloc_skb(struct tun_struct *tun,
577 size_t prepad, size_t len,
578 size_t linear, int noblock)
579 {
580 struct sock *sk = tun->socket.sk;
581 struct sk_buff *skb;
582 int err;
583
584 sock_update_classid(sk);
585
586 /* Under a page? Don't bother with paged skb. */
587 if (prepad + len < PAGE_SIZE || !linear)
588 linear = len;
589
590 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
591 &err);
592 if (!skb)
593 return ERR_PTR(err);
594
595 skb_reserve(skb, prepad);
596 skb_put(skb, linear);
597 skb->data_len = len - linear;
598 skb->len += len - linear;
599
600 return skb;
601 }
602
603 /* Get packet from user space buffer */
604 static ssize_t tun_get_user(struct tun_struct *tun,
605 const struct iovec *iv, size_t count,
606 int noblock)
607 {
608 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
609 struct sk_buff *skb;
610 size_t len = count, align = NET_SKB_PAD;
611 struct virtio_net_hdr gso = { 0 };
612 int offset = 0;
613
614 if (!(tun->flags & TUN_NO_PI)) {
615 if ((len -= sizeof(pi)) > count)
616 return -EINVAL;
617
618 if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
619 return -EFAULT;
620 offset += sizeof(pi);
621 }
622
623 if (tun->flags & TUN_VNET_HDR) {
624 if ((len -= tun->vnet_hdr_sz) > count)
625 return -EINVAL;
626
627 if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
628 return -EFAULT;
629
630 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
631 gso.csum_start + gso.csum_offset + 2 > gso.hdr_len)
632 gso.hdr_len = gso.csum_start + gso.csum_offset + 2;
633
634 if (gso.hdr_len > len)
635 return -EINVAL;
636 offset += tun->vnet_hdr_sz;
637 }
638
639 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
640 align += NET_IP_ALIGN;
641 if (unlikely(len < ETH_HLEN ||
642 (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
643 return -EINVAL;
644 }
645
646 skb = tun_alloc_skb(tun, align, len, gso.hdr_len, noblock);
647 if (IS_ERR(skb)) {
648 if (PTR_ERR(skb) != -EAGAIN)
649 tun->dev->stats.rx_dropped++;
650 return PTR_ERR(skb);
651 }
652
653 if (skb_copy_datagram_from_iovec(skb, 0, iv, offset, len)) {
654 tun->dev->stats.rx_dropped++;
655 kfree_skb(skb);
656 return -EFAULT;
657 }
658
659 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
660 if (!skb_partial_csum_set(skb, gso.csum_start,
661 gso.csum_offset)) {
662 tun->dev->stats.rx_frame_errors++;
663 kfree_skb(skb);
664 return -EINVAL;
665 }
666 }
667
668 switch (tun->flags & TUN_TYPE_MASK) {
669 case TUN_TUN_DEV:
670 if (tun->flags & TUN_NO_PI) {
671 switch (skb->data[0] & 0xf0) {
672 case 0x40:
673 pi.proto = htons(ETH_P_IP);
674 break;
675 case 0x60:
676 pi.proto = htons(ETH_P_IPV6);
677 break;
678 default:
679 tun->dev->stats.rx_dropped++;
680 kfree_skb(skb);
681 return -EINVAL;
682 }
683 }
684
685 skb_reset_mac_header(skb);
686 skb->protocol = pi.proto;
687 skb->dev = tun->dev;
688 break;
689 case TUN_TAP_DEV:
690 skb->protocol = eth_type_trans(skb, tun->dev);
691 break;
692 }
693
694 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
695 pr_debug("GSO!\n");
696 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
697 case VIRTIO_NET_HDR_GSO_TCPV4:
698 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
699 break;
700 case VIRTIO_NET_HDR_GSO_TCPV6:
701 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
702 break;
703 case VIRTIO_NET_HDR_GSO_UDP:
704 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
705 break;
706 default:
707 tun->dev->stats.rx_frame_errors++;
708 kfree_skb(skb);
709 return -EINVAL;
710 }
711
712 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
713 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
714
715 skb_shinfo(skb)->gso_size = gso.gso_size;
716 if (skb_shinfo(skb)->gso_size == 0) {
717 tun->dev->stats.rx_frame_errors++;
718 kfree_skb(skb);
719 return -EINVAL;
720 }
721
722 /* Header must be checked, and gso_segs computed. */
723 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
724 skb_shinfo(skb)->gso_segs = 0;
725 }
726
727 netif_rx_ni(skb);
728
729 tun->dev->stats.rx_packets++;
730 tun->dev->stats.rx_bytes += len;
731
732 return count;
733 }
734
735 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
736 unsigned long count, loff_t pos)
737 {
738 struct file *file = iocb->ki_filp;
739 struct tun_struct *tun = tun_get(file);
740 ssize_t result;
741
742 if (!tun)
743 return -EBADFD;
744
745 tun_debug(KERN_INFO, tun, "tun_chr_write %ld\n", count);
746
747 result = tun_get_user(tun, iv, iov_length(iv, count),
748 file->f_flags & O_NONBLOCK);
749
750 tun_put(tun);
751 return result;
752 }
753
754 /* Put packet to the user space buffer */
755 static ssize_t tun_put_user(struct tun_struct *tun,
756 struct sk_buff *skb,
757 const struct iovec *iv, int len)
758 {
759 struct tun_pi pi = { 0, skb->protocol };
760 ssize_t total = 0;
761
762 if (!(tun->flags & TUN_NO_PI)) {
763 if ((len -= sizeof(pi)) < 0)
764 return -EINVAL;
765
766 if (len < skb->len) {
767 /* Packet will be striped */
768 pi.flags |= TUN_PKT_STRIP;
769 }
770
771 if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi)))
772 return -EFAULT;
773 total += sizeof(pi);
774 }
775
776 if (tun->flags & TUN_VNET_HDR) {
777 struct virtio_net_hdr gso = { 0 }; /* no info leak */
778 if ((len -= tun->vnet_hdr_sz) < 0)
779 return -EINVAL;
780
781 if (skb_is_gso(skb)) {
782 struct skb_shared_info *sinfo = skb_shinfo(skb);
783
784 /* This is a hint as to how much should be linear. */
785 gso.hdr_len = skb_headlen(skb);
786 gso.gso_size = sinfo->gso_size;
787 if (sinfo->gso_type & SKB_GSO_TCPV4)
788 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
789 else if (sinfo->gso_type & SKB_GSO_TCPV6)
790 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
791 else if (sinfo->gso_type & SKB_GSO_UDP)
792 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
793 else {
794 pr_err("unexpected GSO type: "
795 "0x%x, gso_size %d, hdr_len %d\n",
796 sinfo->gso_type, gso.gso_size,
797 gso.hdr_len);
798 print_hex_dump(KERN_ERR, "tun: ",
799 DUMP_PREFIX_NONE,
800 16, 1, skb->head,
801 min((int)gso.hdr_len, 64), true);
802 WARN_ON_ONCE(1);
803 return -EINVAL;
804 }
805 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
806 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
807 } else
808 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
809
810 if (skb->ip_summed == CHECKSUM_PARTIAL) {
811 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
812 gso.csum_start = skb_checksum_start_offset(skb);
813 gso.csum_offset = skb->csum_offset;
814 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
815 gso.flags = VIRTIO_NET_HDR_F_DATA_VALID;
816 } /* else everything is zero */
817
818 if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
819 sizeof(gso))))
820 return -EFAULT;
821 total += tun->vnet_hdr_sz;
822 }
823
824 len = min_t(int, skb->len, len);
825
826 skb_copy_datagram_const_iovec(skb, 0, iv, total, len);
827 total += skb->len;
828
829 tun->dev->stats.tx_packets++;
830 tun->dev->stats.tx_bytes += len;
831
832 return total;
833 }
834
835 static ssize_t tun_do_read(struct tun_struct *tun,
836 struct kiocb *iocb, const struct iovec *iv,
837 ssize_t len, int noblock)
838 {
839 DECLARE_WAITQUEUE(wait, current);
840 struct sk_buff *skb;
841 ssize_t ret = 0;
842
843 tun_debug(KERN_INFO, tun, "tun_chr_read\n");
844
845 if (unlikely(!noblock))
846 add_wait_queue(&tun->wq.wait, &wait);
847 while (len) {
848 current->state = TASK_INTERRUPTIBLE;
849
850 /* Read frames from the queue */
851 if (!(skb=skb_dequeue(&tun->socket.sk->sk_receive_queue))) {
852 if (noblock) {
853 ret = -EAGAIN;
854 break;
855 }
856 if (signal_pending(current)) {
857 ret = -ERESTARTSYS;
858 break;
859 }
860 if (tun->dev->reg_state != NETREG_REGISTERED) {
861 ret = -EIO;
862 break;
863 }
864
865 /* Nothing to read, let's sleep */
866 schedule();
867 continue;
868 }
869 netif_wake_queue(tun->dev);
870
871 ret = tun_put_user(tun, skb, iv, len);
872 kfree_skb(skb);
873 break;
874 }
875
876 current->state = TASK_RUNNING;
877 if (unlikely(!noblock))
878 remove_wait_queue(&tun->wq.wait, &wait);
879
880 return ret;
881 }
882
883 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
884 unsigned long count, loff_t pos)
885 {
886 struct file *file = iocb->ki_filp;
887 struct tun_file *tfile = file->private_data;
888 struct tun_struct *tun = __tun_get(tfile);
889 ssize_t len, ret;
890
891 if (!tun)
892 return -EBADFD;
893 len = iov_length(iv, count);
894 if (len < 0) {
895 ret = -EINVAL;
896 goto out;
897 }
898
899 ret = tun_do_read(tun, iocb, iv, len, file->f_flags & O_NONBLOCK);
900 ret = min_t(ssize_t, ret, len);
901 out:
902 tun_put(tun);
903 return ret;
904 }
905
906 static void tun_setup(struct net_device *dev)
907 {
908 struct tun_struct *tun = netdev_priv(dev);
909
910 tun->owner = -1;
911 tun->group = -1;
912
913 dev->ethtool_ops = &tun_ethtool_ops;
914 dev->destructor = tun_free_netdev;
915 }
916
917 /* Trivial set of netlink ops to allow deleting tun or tap
918 * device with netlink.
919 */
920 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
921 {
922 return -EINVAL;
923 }
924
925 static struct rtnl_link_ops tun_link_ops __read_mostly = {
926 .kind = DRV_NAME,
927 .priv_size = sizeof(struct tun_struct),
928 .setup = tun_setup,
929 .validate = tun_validate,
930 };
931
932 static void tun_sock_write_space(struct sock *sk)
933 {
934 struct tun_struct *tun;
935 wait_queue_head_t *wqueue;
936
937 if (!sock_writeable(sk))
938 return;
939
940 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
941 return;
942
943 wqueue = sk_sleep(sk);
944 if (wqueue && waitqueue_active(wqueue))
945 wake_up_interruptible_sync_poll(wqueue, POLLOUT |
946 POLLWRNORM | POLLWRBAND);
947
948 tun = tun_sk(sk)->tun;
949 kill_fasync(&tun->fasync, SIGIO, POLL_OUT);
950 }
951
952 static void tun_sock_destruct(struct sock *sk)
953 {
954 free_netdev(tun_sk(sk)->tun->dev);
955 }
956
957 static int tun_sendmsg(struct kiocb *iocb, struct socket *sock,
958 struct msghdr *m, size_t total_len)
959 {
960 struct tun_struct *tun = container_of(sock, struct tun_struct, socket);
961 return tun_get_user(tun, m->msg_iov, total_len,
962 m->msg_flags & MSG_DONTWAIT);
963 }
964
965 static int tun_recvmsg(struct kiocb *iocb, struct socket *sock,
966 struct msghdr *m, size_t total_len,
967 int flags)
968 {
969 struct tun_struct *tun = container_of(sock, struct tun_struct, socket);
970 int ret;
971 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC))
972 return -EINVAL;
973 ret = tun_do_read(tun, iocb, m->msg_iov, total_len,
974 flags & MSG_DONTWAIT);
975 if (ret > total_len) {
976 m->msg_flags |= MSG_TRUNC;
977 ret = flags & MSG_TRUNC ? ret : total_len;
978 }
979 return ret;
980 }
981
982 /* Ops structure to mimic raw sockets with tun */
983 static const struct proto_ops tun_socket_ops = {
984 .sendmsg = tun_sendmsg,
985 .recvmsg = tun_recvmsg,
986 };
987
988 static struct proto tun_proto = {
989 .name = "tun",
990 .owner = THIS_MODULE,
991 .obj_size = sizeof(struct tun_sock),
992 };
993
994 static int tun_flags(struct tun_struct *tun)
995 {
996 int flags = 0;
997
998 if (tun->flags & TUN_TUN_DEV)
999 flags |= IFF_TUN;
1000 else
1001 flags |= IFF_TAP;
1002
1003 if (tun->flags & TUN_NO_PI)
1004 flags |= IFF_NO_PI;
1005
1006 if (tun->flags & TUN_ONE_QUEUE)
1007 flags |= IFF_ONE_QUEUE;
1008
1009 if (tun->flags & TUN_VNET_HDR)
1010 flags |= IFF_VNET_HDR;
1011
1012 return flags;
1013 }
1014
1015 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
1016 char *buf)
1017 {
1018 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1019 return sprintf(buf, "0x%x\n", tun_flags(tun));
1020 }
1021
1022 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
1023 char *buf)
1024 {
1025 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1026 return sprintf(buf, "%d\n", tun->owner);
1027 }
1028
1029 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
1030 char *buf)
1031 {
1032 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1033 return sprintf(buf, "%d\n", tun->group);
1034 }
1035
1036 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
1037 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
1038 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
1039
1040 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
1041 {
1042 struct sock *sk;
1043 struct tun_struct *tun;
1044 struct net_device *dev;
1045 int err;
1046
1047 dev = __dev_get_by_name(net, ifr->ifr_name);
1048 if (dev) {
1049 const struct cred *cred = current_cred();
1050
1051 if (ifr->ifr_flags & IFF_TUN_EXCL)
1052 return -EBUSY;
1053 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
1054 tun = netdev_priv(dev);
1055 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
1056 tun = netdev_priv(dev);
1057 else
1058 return -EINVAL;
1059
1060 if (((tun->owner != -1 && cred->euid != tun->owner) ||
1061 (tun->group != -1 && !in_egroup_p(tun->group))) &&
1062 !capable(CAP_NET_ADMIN))
1063 return -EPERM;
1064 err = security_tun_dev_attach(tun->socket.sk);
1065 if (err < 0)
1066 return err;
1067
1068 err = tun_attach(tun, file);
1069 if (err < 0)
1070 return err;
1071 }
1072 else {
1073 char *name;
1074 unsigned long flags = 0;
1075
1076 if (!capable(CAP_NET_ADMIN))
1077 return -EPERM;
1078 err = security_tun_dev_create();
1079 if (err < 0)
1080 return err;
1081
1082 /* Set dev type */
1083 if (ifr->ifr_flags & IFF_TUN) {
1084 /* TUN device */
1085 flags |= TUN_TUN_DEV;
1086 name = "tun%d";
1087 } else if (ifr->ifr_flags & IFF_TAP) {
1088 /* TAP device */
1089 flags |= TUN_TAP_DEV;
1090 name = "tap%d";
1091 } else
1092 return -EINVAL;
1093
1094 if (*ifr->ifr_name)
1095 name = ifr->ifr_name;
1096
1097 dev = alloc_netdev(sizeof(struct tun_struct), name,
1098 tun_setup);
1099 if (!dev)
1100 return -ENOMEM;
1101
1102 dev_net_set(dev, net);
1103 dev->rtnl_link_ops = &tun_link_ops;
1104
1105 tun = netdev_priv(dev);
1106 tun->dev = dev;
1107 tun->flags = flags;
1108 tun->txflt.count = 0;
1109 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
1110
1111 err = -ENOMEM;
1112 sk = sk_alloc(net, AF_UNSPEC, GFP_KERNEL, &tun_proto);
1113 if (!sk)
1114 goto err_free_dev;
1115
1116 tun->socket.wq = &tun->wq;
1117 init_waitqueue_head(&tun->wq.wait);
1118 tun->socket.ops = &tun_socket_ops;
1119 sock_init_data(&tun->socket, sk);
1120 sk->sk_write_space = tun_sock_write_space;
1121 sk->sk_sndbuf = INT_MAX;
1122
1123 tun_sk(sk)->tun = tun;
1124
1125 security_tun_dev_post_create(sk);
1126
1127 tun_net_init(dev);
1128
1129 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
1130 TUN_USER_FEATURES;
1131 dev->features = dev->hw_features;
1132
1133 err = register_netdevice(tun->dev);
1134 if (err < 0)
1135 goto err_free_sk;
1136
1137 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
1138 device_create_file(&tun->dev->dev, &dev_attr_owner) ||
1139 device_create_file(&tun->dev->dev, &dev_attr_group))
1140 pr_err("Failed to create tun sysfs files\n");
1141
1142 sk->sk_destruct = tun_sock_destruct;
1143
1144 err = tun_attach(tun, file);
1145 if (err < 0)
1146 goto failed;
1147 }
1148
1149 tun_debug(KERN_INFO, tun, "tun_set_iff\n");
1150
1151 if (ifr->ifr_flags & IFF_NO_PI)
1152 tun->flags |= TUN_NO_PI;
1153 else
1154 tun->flags &= ~TUN_NO_PI;
1155
1156 if (ifr->ifr_flags & IFF_ONE_QUEUE)
1157 tun->flags |= TUN_ONE_QUEUE;
1158 else
1159 tun->flags &= ~TUN_ONE_QUEUE;
1160
1161 if (ifr->ifr_flags & IFF_VNET_HDR)
1162 tun->flags |= TUN_VNET_HDR;
1163 else
1164 tun->flags &= ~TUN_VNET_HDR;
1165
1166 /* Make sure persistent devices do not get stuck in
1167 * xoff state.
1168 */
1169 if (netif_running(tun->dev))
1170 netif_wake_queue(tun->dev);
1171
1172 strcpy(ifr->ifr_name, tun->dev->name);
1173 return 0;
1174
1175 err_free_sk:
1176 sock_put(sk);
1177 err_free_dev:
1178 free_netdev(dev);
1179 failed:
1180 return err;
1181 }
1182
1183 static int tun_get_iff(struct net *net, struct tun_struct *tun,
1184 struct ifreq *ifr)
1185 {
1186 tun_debug(KERN_INFO, tun, "tun_get_iff\n");
1187
1188 strcpy(ifr->ifr_name, tun->dev->name);
1189
1190 ifr->ifr_flags = tun_flags(tun);
1191
1192 return 0;
1193 }
1194
1195 /* This is like a cut-down ethtool ops, except done via tun fd so no
1196 * privs required. */
1197 static int set_offload(struct tun_struct *tun, unsigned long arg)
1198 {
1199 u32 features = 0;
1200
1201 if (arg & TUN_F_CSUM) {
1202 features |= NETIF_F_HW_CSUM;
1203 arg &= ~TUN_F_CSUM;
1204
1205 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1206 if (arg & TUN_F_TSO_ECN) {
1207 features |= NETIF_F_TSO_ECN;
1208 arg &= ~TUN_F_TSO_ECN;
1209 }
1210 if (arg & TUN_F_TSO4)
1211 features |= NETIF_F_TSO;
1212 if (arg & TUN_F_TSO6)
1213 features |= NETIF_F_TSO6;
1214 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1215 }
1216
1217 if (arg & TUN_F_UFO) {
1218 features |= NETIF_F_UFO;
1219 arg &= ~TUN_F_UFO;
1220 }
1221 }
1222
1223 /* This gives the user a way to test for new features in future by
1224 * trying to set them. */
1225 if (arg)
1226 return -EINVAL;
1227
1228 tun->set_features = features;
1229 netdev_update_features(tun->dev);
1230
1231 return 0;
1232 }
1233
1234 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
1235 unsigned long arg, int ifreq_len)
1236 {
1237 struct tun_file *tfile = file->private_data;
1238 struct tun_struct *tun;
1239 void __user* argp = (void __user*)arg;
1240 struct sock_fprog fprog;
1241 struct ifreq ifr;
1242 int sndbuf;
1243 int vnet_hdr_sz;
1244 int ret;
1245
1246 if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
1247 if (copy_from_user(&ifr, argp, ifreq_len))
1248 return -EFAULT;
1249
1250 if (cmd == TUNGETFEATURES) {
1251 /* Currently this just means: "what IFF flags are valid?".
1252 * This is needed because we never checked for invalid flags on
1253 * TUNSETIFF. */
1254 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
1255 IFF_VNET_HDR,
1256 (unsigned int __user*)argp);
1257 }
1258
1259 rtnl_lock();
1260
1261 tun = __tun_get(tfile);
1262 if (cmd == TUNSETIFF && !tun) {
1263 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1264
1265 ret = tun_set_iff(tfile->net, file, &ifr);
1266
1267 if (ret)
1268 goto unlock;
1269
1270 if (copy_to_user(argp, &ifr, ifreq_len))
1271 ret = -EFAULT;
1272 goto unlock;
1273 }
1274
1275 ret = -EBADFD;
1276 if (!tun)
1277 goto unlock;
1278
1279 tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %d\n", cmd);
1280
1281 ret = 0;
1282 switch (cmd) {
1283 case TUNGETIFF:
1284 ret = tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1285 if (ret)
1286 break;
1287
1288 if (copy_to_user(argp, &ifr, ifreq_len))
1289 ret = -EFAULT;
1290 break;
1291
1292 case TUNSETNOCSUM:
1293 /* Disable/Enable checksum */
1294
1295 /* [unimplemented] */
1296 tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n",
1297 arg ? "disabled" : "enabled");
1298 break;
1299
1300 case TUNSETPERSIST:
1301 /* Disable/Enable persist mode */
1302 if (arg)
1303 tun->flags |= TUN_PERSIST;
1304 else
1305 tun->flags &= ~TUN_PERSIST;
1306
1307 tun_debug(KERN_INFO, tun, "persist %s\n",
1308 arg ? "enabled" : "disabled");
1309 break;
1310
1311 case TUNSETOWNER:
1312 /* Set owner of the device */
1313 tun->owner = (uid_t) arg;
1314
1315 tun_debug(KERN_INFO, tun, "owner set to %d\n", tun->owner);
1316 break;
1317
1318 case TUNSETGROUP:
1319 /* Set group of the device */
1320 tun->group= (gid_t) arg;
1321
1322 tun_debug(KERN_INFO, tun, "group set to %d\n", tun->group);
1323 break;
1324
1325 case TUNSETLINK:
1326 /* Only allow setting the type when the interface is down */
1327 if (tun->dev->flags & IFF_UP) {
1328 tun_debug(KERN_INFO, tun,
1329 "Linktype set failed because interface is up\n");
1330 ret = -EBUSY;
1331 } else {
1332 tun->dev->type = (int) arg;
1333 tun_debug(KERN_INFO, tun, "linktype set to %d\n",
1334 tun->dev->type);
1335 ret = 0;
1336 }
1337 break;
1338
1339 #ifdef TUN_DEBUG
1340 case TUNSETDEBUG:
1341 tun->debug = arg;
1342 break;
1343 #endif
1344 case TUNSETOFFLOAD:
1345 ret = set_offload(tun, arg);
1346 break;
1347
1348 case TUNSETTXFILTER:
1349 /* Can be set only for TAPs */
1350 ret = -EINVAL;
1351 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1352 break;
1353 ret = update_filter(&tun->txflt, (void __user *)arg);
1354 break;
1355
1356 case SIOCGIFHWADDR:
1357 /* Get hw address */
1358 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
1359 ifr.ifr_hwaddr.sa_family = tun->dev->type;
1360 if (copy_to_user(argp, &ifr, ifreq_len))
1361 ret = -EFAULT;
1362 break;
1363
1364 case SIOCSIFHWADDR:
1365 /* Set hw address */
1366 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n",
1367 ifr.ifr_hwaddr.sa_data);
1368
1369 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
1370 break;
1371
1372 case TUNGETSNDBUF:
1373 sndbuf = tun->socket.sk->sk_sndbuf;
1374 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
1375 ret = -EFAULT;
1376 break;
1377
1378 case TUNSETSNDBUF:
1379 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
1380 ret = -EFAULT;
1381 break;
1382 }
1383
1384 tun->socket.sk->sk_sndbuf = sndbuf;
1385 break;
1386
1387 case TUNGETVNETHDRSZ:
1388 vnet_hdr_sz = tun->vnet_hdr_sz;
1389 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
1390 ret = -EFAULT;
1391 break;
1392
1393 case TUNSETVNETHDRSZ:
1394 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
1395 ret = -EFAULT;
1396 break;
1397 }
1398 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
1399 ret = -EINVAL;
1400 break;
1401 }
1402
1403 tun->vnet_hdr_sz = vnet_hdr_sz;
1404 break;
1405
1406 case TUNATTACHFILTER:
1407 /* Can be set only for TAPs */
1408 ret = -EINVAL;
1409 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1410 break;
1411 ret = -EFAULT;
1412 if (copy_from_user(&fprog, argp, sizeof(fprog)))
1413 break;
1414
1415 ret = sk_attach_filter(&fprog, tun->socket.sk);
1416 break;
1417
1418 case TUNDETACHFILTER:
1419 /* Can be set only for TAPs */
1420 ret = -EINVAL;
1421 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1422 break;
1423 ret = sk_detach_filter(tun->socket.sk);
1424 break;
1425
1426 default:
1427 ret = -EINVAL;
1428 break;
1429 }
1430
1431 unlock:
1432 rtnl_unlock();
1433 if (tun)
1434 tun_put(tun);
1435 return ret;
1436 }
1437
1438 static long tun_chr_ioctl(struct file *file,
1439 unsigned int cmd, unsigned long arg)
1440 {
1441 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
1442 }
1443
1444 #ifdef CONFIG_COMPAT
1445 static long tun_chr_compat_ioctl(struct file *file,
1446 unsigned int cmd, unsigned long arg)
1447 {
1448 switch (cmd) {
1449 case TUNSETIFF:
1450 case TUNGETIFF:
1451 case TUNSETTXFILTER:
1452 case TUNGETSNDBUF:
1453 case TUNSETSNDBUF:
1454 case SIOCGIFHWADDR:
1455 case SIOCSIFHWADDR:
1456 arg = (unsigned long)compat_ptr(arg);
1457 break;
1458 default:
1459 arg = (compat_ulong_t)arg;
1460 break;
1461 }
1462
1463 /*
1464 * compat_ifreq is shorter than ifreq, so we must not access beyond
1465 * the end of that structure. All fields that are used in this
1466 * driver are compatible though, we don't need to convert the
1467 * contents.
1468 */
1469 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
1470 }
1471 #endif /* CONFIG_COMPAT */
1472
1473 static int tun_chr_fasync(int fd, struct file *file, int on)
1474 {
1475 struct tun_struct *tun = tun_get(file);
1476 int ret;
1477
1478 if (!tun)
1479 return -EBADFD;
1480
1481 tun_debug(KERN_INFO, tun, "tun_chr_fasync %d\n", on);
1482
1483 if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
1484 goto out;
1485
1486 if (on) {
1487 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
1488 if (ret)
1489 goto out;
1490 tun->flags |= TUN_FASYNC;
1491 } else
1492 tun->flags &= ~TUN_FASYNC;
1493 ret = 0;
1494 out:
1495 tun_put(tun);
1496 return ret;
1497 }
1498
1499 static int tun_chr_open(struct inode *inode, struct file * file)
1500 {
1501 struct tun_file *tfile;
1502
1503 DBG1(KERN_INFO, "tunX: tun_chr_open\n");
1504
1505 tfile = kmalloc(sizeof(*tfile), GFP_KERNEL);
1506 if (!tfile)
1507 return -ENOMEM;
1508 atomic_set(&tfile->count, 0);
1509 tfile->tun = NULL;
1510 tfile->net = get_net(current->nsproxy->net_ns);
1511 file->private_data = tfile;
1512 return 0;
1513 }
1514
1515 static int tun_chr_close(struct inode *inode, struct file *file)
1516 {
1517 struct tun_file *tfile = file->private_data;
1518 struct tun_struct *tun;
1519
1520 tun = __tun_get(tfile);
1521 if (tun) {
1522 struct net_device *dev = tun->dev;
1523
1524 tun_debug(KERN_INFO, tun, "tun_chr_close\n");
1525
1526 __tun_detach(tun);
1527
1528 /* If desirable, unregister the netdevice. */
1529 if (!(tun->flags & TUN_PERSIST)) {
1530 rtnl_lock();
1531 if (dev->reg_state == NETREG_REGISTERED)
1532 unregister_netdevice(dev);
1533 rtnl_unlock();
1534 }
1535 }
1536
1537 tun = tfile->tun;
1538 if (tun)
1539 sock_put(tun->socket.sk);
1540
1541 put_net(tfile->net);
1542 kfree(tfile);
1543
1544 return 0;
1545 }
1546
1547 static const struct file_operations tun_fops = {
1548 .owner = THIS_MODULE,
1549 .llseek = no_llseek,
1550 .read = do_sync_read,
1551 .aio_read = tun_chr_aio_read,
1552 .write = do_sync_write,
1553 .aio_write = tun_chr_aio_write,
1554 .poll = tun_chr_poll,
1555 .unlocked_ioctl = tun_chr_ioctl,
1556 #ifdef CONFIG_COMPAT
1557 .compat_ioctl = tun_chr_compat_ioctl,
1558 #endif
1559 .open = tun_chr_open,
1560 .release = tun_chr_close,
1561 .fasync = tun_chr_fasync
1562 };
1563
1564 static struct miscdevice tun_miscdev = {
1565 .minor = TUN_MINOR,
1566 .name = "tun",
1567 .nodename = "net/tun",
1568 .fops = &tun_fops,
1569 };
1570
1571 /* ethtool interface */
1572
1573 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1574 {
1575 cmd->supported = 0;
1576 cmd->advertising = 0;
1577 ethtool_cmd_speed_set(cmd, SPEED_10);
1578 cmd->duplex = DUPLEX_FULL;
1579 cmd->port = PORT_TP;
1580 cmd->phy_address = 0;
1581 cmd->transceiver = XCVR_INTERNAL;
1582 cmd->autoneg = AUTONEG_DISABLE;
1583 cmd->maxtxpkt = 0;
1584 cmd->maxrxpkt = 0;
1585 return 0;
1586 }
1587
1588 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
1589 {
1590 struct tun_struct *tun = netdev_priv(dev);
1591
1592 strcpy(info->driver, DRV_NAME);
1593 strcpy(info->version, DRV_VERSION);
1594 strcpy(info->fw_version, "N/A");
1595
1596 switch (tun->flags & TUN_TYPE_MASK) {
1597 case TUN_TUN_DEV:
1598 strcpy(info->bus_info, "tun");
1599 break;
1600 case TUN_TAP_DEV:
1601 strcpy(info->bus_info, "tap");
1602 break;
1603 }
1604 }
1605
1606 static u32 tun_get_msglevel(struct net_device *dev)
1607 {
1608 #ifdef TUN_DEBUG
1609 struct tun_struct *tun = netdev_priv(dev);
1610 return tun->debug;
1611 #else
1612 return -EOPNOTSUPP;
1613 #endif
1614 }
1615
1616 static void tun_set_msglevel(struct net_device *dev, u32 value)
1617 {
1618 #ifdef TUN_DEBUG
1619 struct tun_struct *tun = netdev_priv(dev);
1620 tun->debug = value;
1621 #endif
1622 }
1623
1624 static const struct ethtool_ops tun_ethtool_ops = {
1625 .get_settings = tun_get_settings,
1626 .get_drvinfo = tun_get_drvinfo,
1627 .get_msglevel = tun_get_msglevel,
1628 .set_msglevel = tun_set_msglevel,
1629 .get_link = ethtool_op_get_link,
1630 };
1631
1632
1633 static int __init tun_init(void)
1634 {
1635 int ret = 0;
1636
1637 pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
1638 pr_info("%s\n", DRV_COPYRIGHT);
1639
1640 ret = rtnl_link_register(&tun_link_ops);
1641 if (ret) {
1642 pr_err("Can't register link_ops\n");
1643 goto err_linkops;
1644 }
1645
1646 ret = misc_register(&tun_miscdev);
1647 if (ret) {
1648 pr_err("Can't register misc device %d\n", TUN_MINOR);
1649 goto err_misc;
1650 }
1651 return 0;
1652 err_misc:
1653 rtnl_link_unregister(&tun_link_ops);
1654 err_linkops:
1655 return ret;
1656 }
1657
1658 static void tun_cleanup(void)
1659 {
1660 misc_deregister(&tun_miscdev);
1661 rtnl_link_unregister(&tun_link_ops);
1662 }
1663
1664 /* Get an underlying socket object from tun file. Returns error unless file is
1665 * attached to a device. The returned object works like a packet socket, it
1666 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
1667 * holding a reference to the file for as long as the socket is in use. */
1668 struct socket *tun_get_socket(struct file *file)
1669 {
1670 struct tun_struct *tun;
1671 if (file->f_op != &tun_fops)
1672 return ERR_PTR(-EINVAL);
1673 tun = tun_get(file);
1674 if (!tun)
1675 return ERR_PTR(-EBADFD);
1676 tun_put(tun);
1677 return &tun->socket;
1678 }
1679 EXPORT_SYMBOL_GPL(tun_get_socket);
1680
1681 module_init(tun_init);
1682 module_exit(tun_cleanup);
1683 MODULE_DESCRIPTION(DRV_DESCRIPTION);
1684 MODULE_AUTHOR(DRV_COPYRIGHT);
1685 MODULE_LICENSE("GPL");
1686 MODULE_ALIAS_MISCDEV(TUN_MINOR);
1687 MODULE_ALIAS("devname:net/tun");
Linux Btrfs Development