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[mirror_ubuntu-zesty-kernel.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 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
464 static const struct net_device_ops tun_netdev_ops = {
465 .ndo_uninit = tun_net_uninit,
466 .ndo_open = tun_net_open,
467 .ndo_stop = tun_net_close,
468 .ndo_start_xmit = tun_net_xmit,
469 .ndo_change_mtu = tun_net_change_mtu,
470 .ndo_fix_features = tun_net_fix_features,
471 };
472
473 static const struct net_device_ops tap_netdev_ops = {
474 .ndo_uninit = tun_net_uninit,
475 .ndo_open = tun_net_open,
476 .ndo_stop = tun_net_close,
477 .ndo_start_xmit = tun_net_xmit,
478 .ndo_change_mtu = tun_net_change_mtu,
479 .ndo_fix_features = tun_net_fix_features,
480 .ndo_set_multicast_list = tun_net_mclist,
481 .ndo_set_mac_address = eth_mac_addr,
482 .ndo_validate_addr = eth_validate_addr,
483 };
484
485 /* Initialize net device. */
486 static void tun_net_init(struct net_device *dev)
487 {
488 struct tun_struct *tun = netdev_priv(dev);
489
490 switch (tun->flags & TUN_TYPE_MASK) {
491 case TUN_TUN_DEV:
492 dev->netdev_ops = &tun_netdev_ops;
493
494 /* Point-to-Point TUN Device */
495 dev->hard_header_len = 0;
496 dev->addr_len = 0;
497 dev->mtu = 1500;
498
499 /* Zero header length */
500 dev->type = ARPHRD_NONE;
501 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
502 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
503 break;
504
505 case TUN_TAP_DEV:
506 dev->netdev_ops = &tap_netdev_ops;
507 /* Ethernet TAP Device */
508 ether_setup(dev);
509
510 random_ether_addr(dev->dev_addr);
511
512 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
513 break;
514 }
515 }
516
517 /* Character device part */
518
519 /* Poll */
520 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
521 {
522 struct tun_file *tfile = file->private_data;
523 struct tun_struct *tun = __tun_get(tfile);
524 struct sock *sk;
525 unsigned int mask = 0;
526
527 if (!tun)
528 return POLLERR;
529
530 sk = tun->socket.sk;
531
532 tun_debug(KERN_INFO, tun, "tun_chr_poll\n");
533
534 poll_wait(file, &tun->wq.wait, wait);
535
536 if (!skb_queue_empty(&sk->sk_receive_queue))
537 mask |= POLLIN | POLLRDNORM;
538
539 if (sock_writeable(sk) ||
540 (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
541 sock_writeable(sk)))
542 mask |= POLLOUT | POLLWRNORM;
543
544 if (tun->dev->reg_state != NETREG_REGISTERED)
545 mask = POLLERR;
546
547 tun_put(tun);
548 return mask;
549 }
550
551 /* prepad is the amount to reserve at front. len is length after that.
552 * linear is a hint as to how much to copy (usually headers). */
553 static inline struct sk_buff *tun_alloc_skb(struct tun_struct *tun,
554 size_t prepad, size_t len,
555 size_t linear, int noblock)
556 {
557 struct sock *sk = tun->socket.sk;
558 struct sk_buff *skb;
559 int err;
560
561 sock_update_classid(sk);
562
563 /* Under a page? Don't bother with paged skb. */
564 if (prepad + len < PAGE_SIZE || !linear)
565 linear = len;
566
567 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
568 &err);
569 if (!skb)
570 return ERR_PTR(err);
571
572 skb_reserve(skb, prepad);
573 skb_put(skb, linear);
574 skb->data_len = len - linear;
575 skb->len += len - linear;
576
577 return skb;
578 }
579
580 /* Get packet from user space buffer */
581 static __inline__ ssize_t tun_get_user(struct tun_struct *tun,
582 const struct iovec *iv, size_t count,
583 int noblock)
584 {
585 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
586 struct sk_buff *skb;
587 size_t len = count, align = 0;
588 struct virtio_net_hdr gso = { 0 };
589 int offset = 0;
590
591 if (!(tun->flags & TUN_NO_PI)) {
592 if ((len -= sizeof(pi)) > count)
593 return -EINVAL;
594
595 if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
596 return -EFAULT;
597 offset += sizeof(pi);
598 }
599
600 if (tun->flags & TUN_VNET_HDR) {
601 if ((len -= tun->vnet_hdr_sz) > count)
602 return -EINVAL;
603
604 if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
605 return -EFAULT;
606
607 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
608 gso.csum_start + gso.csum_offset + 2 > gso.hdr_len)
609 gso.hdr_len = gso.csum_start + gso.csum_offset + 2;
610
611 if (gso.hdr_len > len)
612 return -EINVAL;
613 offset += tun->vnet_hdr_sz;
614 }
615
616 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
617 align = NET_IP_ALIGN;
618 if (unlikely(len < ETH_HLEN ||
619 (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
620 return -EINVAL;
621 }
622
623 skb = tun_alloc_skb(tun, align, len, gso.hdr_len, noblock);
624 if (IS_ERR(skb)) {
625 if (PTR_ERR(skb) != -EAGAIN)
626 tun->dev->stats.rx_dropped++;
627 return PTR_ERR(skb);
628 }
629
630 if (skb_copy_datagram_from_iovec(skb, 0, iv, offset, len)) {
631 tun->dev->stats.rx_dropped++;
632 kfree_skb(skb);
633 return -EFAULT;
634 }
635
636 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
637 if (!skb_partial_csum_set(skb, gso.csum_start,
638 gso.csum_offset)) {
639 tun->dev->stats.rx_frame_errors++;
640 kfree_skb(skb);
641 return -EINVAL;
642 }
643 }
644
645 switch (tun->flags & TUN_TYPE_MASK) {
646 case TUN_TUN_DEV:
647 if (tun->flags & TUN_NO_PI) {
648 switch (skb->data[0] & 0xf0) {
649 case 0x40:
650 pi.proto = htons(ETH_P_IP);
651 break;
652 case 0x60:
653 pi.proto = htons(ETH_P_IPV6);
654 break;
655 default:
656 tun->dev->stats.rx_dropped++;
657 kfree_skb(skb);
658 return -EINVAL;
659 }
660 }
661
662 skb_reset_mac_header(skb);
663 skb->protocol = pi.proto;
664 skb->dev = tun->dev;
665 break;
666 case TUN_TAP_DEV:
667 skb->protocol = eth_type_trans(skb, tun->dev);
668 break;
669 };
670
671 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
672 pr_debug("GSO!\n");
673 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
674 case VIRTIO_NET_HDR_GSO_TCPV4:
675 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
676 break;
677 case VIRTIO_NET_HDR_GSO_TCPV6:
678 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
679 break;
680 case VIRTIO_NET_HDR_GSO_UDP:
681 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
682 break;
683 default:
684 tun->dev->stats.rx_frame_errors++;
685 kfree_skb(skb);
686 return -EINVAL;
687 }
688
689 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
690 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
691
692 skb_shinfo(skb)->gso_size = gso.gso_size;
693 if (skb_shinfo(skb)->gso_size == 0) {
694 tun->dev->stats.rx_frame_errors++;
695 kfree_skb(skb);
696 return -EINVAL;
697 }
698
699 /* Header must be checked, and gso_segs computed. */
700 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
701 skb_shinfo(skb)->gso_segs = 0;
702 }
703
704 netif_rx_ni(skb);
705
706 tun->dev->stats.rx_packets++;
707 tun->dev->stats.rx_bytes += len;
708
709 return count;
710 }
711
712 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
713 unsigned long count, loff_t pos)
714 {
715 struct file *file = iocb->ki_filp;
716 struct tun_struct *tun = tun_get(file);
717 ssize_t result;
718
719 if (!tun)
720 return -EBADFD;
721
722 tun_debug(KERN_INFO, tun, "tun_chr_write %ld\n", count);
723
724 result = tun_get_user(tun, iv, iov_length(iv, count),
725 file->f_flags & O_NONBLOCK);
726
727 tun_put(tun);
728 return result;
729 }
730
731 /* Put packet to the user space buffer */
732 static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
733 struct sk_buff *skb,
734 const struct iovec *iv, int len)
735 {
736 struct tun_pi pi = { 0, skb->protocol };
737 ssize_t total = 0;
738
739 if (!(tun->flags & TUN_NO_PI)) {
740 if ((len -= sizeof(pi)) < 0)
741 return -EINVAL;
742
743 if (len < skb->len) {
744 /* Packet will be striped */
745 pi.flags |= TUN_PKT_STRIP;
746 }
747
748 if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi)))
749 return -EFAULT;
750 total += sizeof(pi);
751 }
752
753 if (tun->flags & TUN_VNET_HDR) {
754 struct virtio_net_hdr gso = { 0 }; /* no info leak */
755 if ((len -= tun->vnet_hdr_sz) < 0)
756 return -EINVAL;
757
758 if (skb_is_gso(skb)) {
759 struct skb_shared_info *sinfo = skb_shinfo(skb);
760
761 /* This is a hint as to how much should be linear. */
762 gso.hdr_len = skb_headlen(skb);
763 gso.gso_size = sinfo->gso_size;
764 if (sinfo->gso_type & SKB_GSO_TCPV4)
765 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
766 else if (sinfo->gso_type & SKB_GSO_TCPV6)
767 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
768 else if (sinfo->gso_type & SKB_GSO_UDP)
769 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
770 else {
771 pr_err("unexpected GSO type: "
772 "0x%x, gso_size %d, hdr_len %d\n",
773 sinfo->gso_type, gso.gso_size,
774 gso.hdr_len);
775 print_hex_dump(KERN_ERR, "tun: ",
776 DUMP_PREFIX_NONE,
777 16, 1, skb->head,
778 min((int)gso.hdr_len, 64), true);
779 WARN_ON_ONCE(1);
780 return -EINVAL;
781 }
782 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
783 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
784 } else
785 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
786
787 if (skb->ip_summed == CHECKSUM_PARTIAL) {
788 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
789 gso.csum_start = skb_checksum_start_offset(skb);
790 gso.csum_offset = skb->csum_offset;
791 } /* else everything is zero */
792
793 if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
794 sizeof(gso))))
795 return -EFAULT;
796 total += tun->vnet_hdr_sz;
797 }
798
799 len = min_t(int, skb->len, len);
800
801 skb_copy_datagram_const_iovec(skb, 0, iv, total, len);
802 total += skb->len;
803
804 tun->dev->stats.tx_packets++;
805 tun->dev->stats.tx_bytes += len;
806
807 return total;
808 }
809
810 static ssize_t tun_do_read(struct tun_struct *tun,
811 struct kiocb *iocb, const struct iovec *iv,
812 ssize_t len, int noblock)
813 {
814 DECLARE_WAITQUEUE(wait, current);
815 struct sk_buff *skb;
816 ssize_t ret = 0;
817
818 tun_debug(KERN_INFO, tun, "tun_chr_read\n");
819
820 add_wait_queue(&tun->wq.wait, &wait);
821 while (len) {
822 current->state = TASK_INTERRUPTIBLE;
823
824 /* Read frames from the queue */
825 if (!(skb=skb_dequeue(&tun->socket.sk->sk_receive_queue))) {
826 if (noblock) {
827 ret = -EAGAIN;
828 break;
829 }
830 if (signal_pending(current)) {
831 ret = -ERESTARTSYS;
832 break;
833 }
834 if (tun->dev->reg_state != NETREG_REGISTERED) {
835 ret = -EIO;
836 break;
837 }
838
839 /* Nothing to read, let's sleep */
840 schedule();
841 continue;
842 }
843 netif_wake_queue(tun->dev);
844
845 ret = tun_put_user(tun, skb, iv, len);
846 kfree_skb(skb);
847 break;
848 }
849
850 current->state = TASK_RUNNING;
851 remove_wait_queue(&tun->wq.wait, &wait);
852
853 return ret;
854 }
855
856 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
857 unsigned long count, loff_t pos)
858 {
859 struct file *file = iocb->ki_filp;
860 struct tun_file *tfile = file->private_data;
861 struct tun_struct *tun = __tun_get(tfile);
862 ssize_t len, ret;
863
864 if (!tun)
865 return -EBADFD;
866 len = iov_length(iv, count);
867 if (len < 0) {
868 ret = -EINVAL;
869 goto out;
870 }
871
872 ret = tun_do_read(tun, iocb, iv, len, file->f_flags & O_NONBLOCK);
873 ret = min_t(ssize_t, ret, len);
874 out:
875 tun_put(tun);
876 return ret;
877 }
878
879 static void tun_setup(struct net_device *dev)
880 {
881 struct tun_struct *tun = netdev_priv(dev);
882
883 tun->owner = -1;
884 tun->group = -1;
885
886 dev->ethtool_ops = &tun_ethtool_ops;
887 dev->destructor = tun_free_netdev;
888 }
889
890 /* Trivial set of netlink ops to allow deleting tun or tap
891 * device with netlink.
892 */
893 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
894 {
895 return -EINVAL;
896 }
897
898 static struct rtnl_link_ops tun_link_ops __read_mostly = {
899 .kind = DRV_NAME,
900 .priv_size = sizeof(struct tun_struct),
901 .setup = tun_setup,
902 .validate = tun_validate,
903 };
904
905 static void tun_sock_write_space(struct sock *sk)
906 {
907 struct tun_struct *tun;
908 wait_queue_head_t *wqueue;
909
910 if (!sock_writeable(sk))
911 return;
912
913 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
914 return;
915
916 wqueue = sk_sleep(sk);
917 if (wqueue && waitqueue_active(wqueue))
918 wake_up_interruptible_sync_poll(wqueue, POLLOUT |
919 POLLWRNORM | POLLWRBAND);
920
921 tun = tun_sk(sk)->tun;
922 kill_fasync(&tun->fasync, SIGIO, POLL_OUT);
923 }
924
925 static void tun_sock_destruct(struct sock *sk)
926 {
927 free_netdev(tun_sk(sk)->tun->dev);
928 }
929
930 static int tun_sendmsg(struct kiocb *iocb, struct socket *sock,
931 struct msghdr *m, size_t total_len)
932 {
933 struct tun_struct *tun = container_of(sock, struct tun_struct, socket);
934 return tun_get_user(tun, m->msg_iov, total_len,
935 m->msg_flags & MSG_DONTWAIT);
936 }
937
938 static int tun_recvmsg(struct kiocb *iocb, struct socket *sock,
939 struct msghdr *m, size_t total_len,
940 int flags)
941 {
942 struct tun_struct *tun = container_of(sock, struct tun_struct, socket);
943 int ret;
944 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC))
945 return -EINVAL;
946 ret = tun_do_read(tun, iocb, m->msg_iov, total_len,
947 flags & MSG_DONTWAIT);
948 if (ret > total_len) {
949 m->msg_flags |= MSG_TRUNC;
950 ret = flags & MSG_TRUNC ? ret : total_len;
951 }
952 return ret;
953 }
954
955 /* Ops structure to mimic raw sockets with tun */
956 static const struct proto_ops tun_socket_ops = {
957 .sendmsg = tun_sendmsg,
958 .recvmsg = tun_recvmsg,
959 };
960
961 static struct proto tun_proto = {
962 .name = "tun",
963 .owner = THIS_MODULE,
964 .obj_size = sizeof(struct tun_sock),
965 };
966
967 static int tun_flags(struct tun_struct *tun)
968 {
969 int flags = 0;
970
971 if (tun->flags & TUN_TUN_DEV)
972 flags |= IFF_TUN;
973 else
974 flags |= IFF_TAP;
975
976 if (tun->flags & TUN_NO_PI)
977 flags |= IFF_NO_PI;
978
979 if (tun->flags & TUN_ONE_QUEUE)
980 flags |= IFF_ONE_QUEUE;
981
982 if (tun->flags & TUN_VNET_HDR)
983 flags |= IFF_VNET_HDR;
984
985 return flags;
986 }
987
988 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
989 char *buf)
990 {
991 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
992 return sprintf(buf, "0x%x\n", tun_flags(tun));
993 }
994
995 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
996 char *buf)
997 {
998 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
999 return sprintf(buf, "%d\n", tun->owner);
1000 }
1001
1002 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
1003 char *buf)
1004 {
1005 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1006 return sprintf(buf, "%d\n", tun->group);
1007 }
1008
1009 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
1010 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
1011 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
1012
1013 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
1014 {
1015 struct sock *sk;
1016 struct tun_struct *tun;
1017 struct net_device *dev;
1018 int err;
1019
1020 dev = __dev_get_by_name(net, ifr->ifr_name);
1021 if (dev) {
1022 const struct cred *cred = current_cred();
1023
1024 if (ifr->ifr_flags & IFF_TUN_EXCL)
1025 return -EBUSY;
1026 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
1027 tun = netdev_priv(dev);
1028 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
1029 tun = netdev_priv(dev);
1030 else
1031 return -EINVAL;
1032
1033 if (((tun->owner != -1 && cred->euid != tun->owner) ||
1034 (tun->group != -1 && !in_egroup_p(tun->group))) &&
1035 !capable(CAP_NET_ADMIN))
1036 return -EPERM;
1037 err = security_tun_dev_attach(tun->socket.sk);
1038 if (err < 0)
1039 return err;
1040
1041 err = tun_attach(tun, file);
1042 if (err < 0)
1043 return err;
1044 }
1045 else {
1046 char *name;
1047 unsigned long flags = 0;
1048
1049 if (!capable(CAP_NET_ADMIN))
1050 return -EPERM;
1051 err = security_tun_dev_create();
1052 if (err < 0)
1053 return err;
1054
1055 /* Set dev type */
1056 if (ifr->ifr_flags & IFF_TUN) {
1057 /* TUN device */
1058 flags |= TUN_TUN_DEV;
1059 name = "tun%d";
1060 } else if (ifr->ifr_flags & IFF_TAP) {
1061 /* TAP device */
1062 flags |= TUN_TAP_DEV;
1063 name = "tap%d";
1064 } else
1065 return -EINVAL;
1066
1067 if (*ifr->ifr_name)
1068 name = ifr->ifr_name;
1069
1070 dev = alloc_netdev(sizeof(struct tun_struct), name,
1071 tun_setup);
1072 if (!dev)
1073 return -ENOMEM;
1074
1075 dev_net_set(dev, net);
1076 dev->rtnl_link_ops = &tun_link_ops;
1077
1078 tun = netdev_priv(dev);
1079 tun->dev = dev;
1080 tun->flags = flags;
1081 tun->txflt.count = 0;
1082 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
1083
1084 err = -ENOMEM;
1085 sk = sk_alloc(net, AF_UNSPEC, GFP_KERNEL, &tun_proto);
1086 if (!sk)
1087 goto err_free_dev;
1088
1089 tun->socket.wq = &tun->wq;
1090 init_waitqueue_head(&tun->wq.wait);
1091 tun->socket.ops = &tun_socket_ops;
1092 sock_init_data(&tun->socket, sk);
1093 sk->sk_write_space = tun_sock_write_space;
1094 sk->sk_sndbuf = INT_MAX;
1095
1096 tun_sk(sk)->tun = tun;
1097
1098 security_tun_dev_post_create(sk);
1099
1100 tun_net_init(dev);
1101
1102 if (strchr(dev->name, '%')) {
1103 err = dev_alloc_name(dev, dev->name);
1104 if (err < 0)
1105 goto err_free_sk;
1106 }
1107
1108 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
1109 TUN_USER_FEATURES;
1110 dev->features = dev->hw_features;
1111
1112 err = register_netdevice(tun->dev);
1113 if (err < 0)
1114 goto err_free_sk;
1115
1116 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
1117 device_create_file(&tun->dev->dev, &dev_attr_owner) ||
1118 device_create_file(&tun->dev->dev, &dev_attr_group))
1119 pr_err("Failed to create tun sysfs files\n");
1120
1121 sk->sk_destruct = tun_sock_destruct;
1122
1123 err = tun_attach(tun, file);
1124 if (err < 0)
1125 goto failed;
1126 }
1127
1128 tun_debug(KERN_INFO, tun, "tun_set_iff\n");
1129
1130 if (ifr->ifr_flags & IFF_NO_PI)
1131 tun->flags |= TUN_NO_PI;
1132 else
1133 tun->flags &= ~TUN_NO_PI;
1134
1135 if (ifr->ifr_flags & IFF_ONE_QUEUE)
1136 tun->flags |= TUN_ONE_QUEUE;
1137 else
1138 tun->flags &= ~TUN_ONE_QUEUE;
1139
1140 if (ifr->ifr_flags & IFF_VNET_HDR)
1141 tun->flags |= TUN_VNET_HDR;
1142 else
1143 tun->flags &= ~TUN_VNET_HDR;
1144
1145 /* Make sure persistent devices do not get stuck in
1146 * xoff state.
1147 */
1148 if (netif_running(tun->dev))
1149 netif_wake_queue(tun->dev);
1150
1151 strcpy(ifr->ifr_name, tun->dev->name);
1152 return 0;
1153
1154 err_free_sk:
1155 sock_put(sk);
1156 err_free_dev:
1157 free_netdev(dev);
1158 failed:
1159 return err;
1160 }
1161
1162 static int tun_get_iff(struct net *net, struct tun_struct *tun,
1163 struct ifreq *ifr)
1164 {
1165 tun_debug(KERN_INFO, tun, "tun_get_iff\n");
1166
1167 strcpy(ifr->ifr_name, tun->dev->name);
1168
1169 ifr->ifr_flags = tun_flags(tun);
1170
1171 return 0;
1172 }
1173
1174 /* This is like a cut-down ethtool ops, except done via tun fd so no
1175 * privs required. */
1176 static int set_offload(struct tun_struct *tun, unsigned long arg)
1177 {
1178 u32 features = 0;
1179
1180 if (arg & TUN_F_CSUM) {
1181 features |= NETIF_F_HW_CSUM;
1182 arg &= ~TUN_F_CSUM;
1183
1184 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1185 if (arg & TUN_F_TSO_ECN) {
1186 features |= NETIF_F_TSO_ECN;
1187 arg &= ~TUN_F_TSO_ECN;
1188 }
1189 if (arg & TUN_F_TSO4)
1190 features |= NETIF_F_TSO;
1191 if (arg & TUN_F_TSO6)
1192 features |= NETIF_F_TSO6;
1193 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1194 }
1195
1196 if (arg & TUN_F_UFO) {
1197 features |= NETIF_F_UFO;
1198 arg &= ~TUN_F_UFO;
1199 }
1200 }
1201
1202 /* This gives the user a way to test for new features in future by
1203 * trying to set them. */
1204 if (arg)
1205 return -EINVAL;
1206
1207 tun->set_features = features;
1208 netdev_update_features(tun->dev);
1209
1210 return 0;
1211 }
1212
1213 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
1214 unsigned long arg, int ifreq_len)
1215 {
1216 struct tun_file *tfile = file->private_data;
1217 struct tun_struct *tun;
1218 void __user* argp = (void __user*)arg;
1219 struct sock_fprog fprog;
1220 struct ifreq ifr;
1221 int sndbuf;
1222 int vnet_hdr_sz;
1223 int ret;
1224
1225 if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
1226 if (copy_from_user(&ifr, argp, ifreq_len))
1227 return -EFAULT;
1228
1229 if (cmd == TUNGETFEATURES) {
1230 /* Currently this just means: "what IFF flags are valid?".
1231 * This is needed because we never checked for invalid flags on
1232 * TUNSETIFF. */
1233 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
1234 IFF_VNET_HDR,
1235 (unsigned int __user*)argp);
1236 }
1237
1238 rtnl_lock();
1239
1240 tun = __tun_get(tfile);
1241 if (cmd == TUNSETIFF && !tun) {
1242 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1243
1244 ret = tun_set_iff(tfile->net, file, &ifr);
1245
1246 if (ret)
1247 goto unlock;
1248
1249 if (copy_to_user(argp, &ifr, ifreq_len))
1250 ret = -EFAULT;
1251 goto unlock;
1252 }
1253
1254 ret = -EBADFD;
1255 if (!tun)
1256 goto unlock;
1257
1258 tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %d\n", cmd);
1259
1260 ret = 0;
1261 switch (cmd) {
1262 case TUNGETIFF:
1263 ret = tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1264 if (ret)
1265 break;
1266
1267 if (copy_to_user(argp, &ifr, ifreq_len))
1268 ret = -EFAULT;
1269 break;
1270
1271 case TUNSETNOCSUM:
1272 /* Disable/Enable checksum */
1273
1274 /* [unimplemented] */
1275 tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n",
1276 arg ? "disabled" : "enabled");
1277 break;
1278
1279 case TUNSETPERSIST:
1280 /* Disable/Enable persist mode */
1281 if (arg)
1282 tun->flags |= TUN_PERSIST;
1283 else
1284 tun->flags &= ~TUN_PERSIST;
1285
1286 tun_debug(KERN_INFO, tun, "persist %s\n",
1287 arg ? "enabled" : "disabled");
1288 break;
1289
1290 case TUNSETOWNER:
1291 /* Set owner of the device */
1292 tun->owner = (uid_t) arg;
1293
1294 tun_debug(KERN_INFO, tun, "owner set to %d\n", tun->owner);
1295 break;
1296
1297 case TUNSETGROUP:
1298 /* Set group of the device */
1299 tun->group= (gid_t) arg;
1300
1301 tun_debug(KERN_INFO, tun, "group set to %d\n", tun->group);
1302 break;
1303
1304 case TUNSETLINK:
1305 /* Only allow setting the type when the interface is down */
1306 if (tun->dev->flags & IFF_UP) {
1307 tun_debug(KERN_INFO, tun,
1308 "Linktype set failed because interface is up\n");
1309 ret = -EBUSY;
1310 } else {
1311 tun->dev->type = (int) arg;
1312 tun_debug(KERN_INFO, tun, "linktype set to %d\n",
1313 tun->dev->type);
1314 ret = 0;
1315 }
1316 break;
1317
1318 #ifdef TUN_DEBUG
1319 case TUNSETDEBUG:
1320 tun->debug = arg;
1321 break;
1322 #endif
1323 case TUNSETOFFLOAD:
1324 ret = set_offload(tun, arg);
1325 break;
1326
1327 case TUNSETTXFILTER:
1328 /* Can be set only for TAPs */
1329 ret = -EINVAL;
1330 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1331 break;
1332 ret = update_filter(&tun->txflt, (void __user *)arg);
1333 break;
1334
1335 case SIOCGIFHWADDR:
1336 /* Get hw address */
1337 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
1338 ifr.ifr_hwaddr.sa_family = tun->dev->type;
1339 if (copy_to_user(argp, &ifr, ifreq_len))
1340 ret = -EFAULT;
1341 break;
1342
1343 case SIOCSIFHWADDR:
1344 /* Set hw address */
1345 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n",
1346 ifr.ifr_hwaddr.sa_data);
1347
1348 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
1349 break;
1350
1351 case TUNGETSNDBUF:
1352 sndbuf = tun->socket.sk->sk_sndbuf;
1353 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
1354 ret = -EFAULT;
1355 break;
1356
1357 case TUNSETSNDBUF:
1358 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
1359 ret = -EFAULT;
1360 break;
1361 }
1362
1363 tun->socket.sk->sk_sndbuf = sndbuf;
1364 break;
1365
1366 case TUNGETVNETHDRSZ:
1367 vnet_hdr_sz = tun->vnet_hdr_sz;
1368 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
1369 ret = -EFAULT;
1370 break;
1371
1372 case TUNSETVNETHDRSZ:
1373 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
1374 ret = -EFAULT;
1375 break;
1376 }
1377 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
1378 ret = -EINVAL;
1379 break;
1380 }
1381
1382 tun->vnet_hdr_sz = vnet_hdr_sz;
1383 break;
1384
1385 case TUNATTACHFILTER:
1386 /* Can be set only for TAPs */
1387 ret = -EINVAL;
1388 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1389 break;
1390 ret = -EFAULT;
1391 if (copy_from_user(&fprog, argp, sizeof(fprog)))
1392 break;
1393
1394 ret = sk_attach_filter(&fprog, tun->socket.sk);
1395 break;
1396
1397 case TUNDETACHFILTER:
1398 /* Can be set only for TAPs */
1399 ret = -EINVAL;
1400 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1401 break;
1402 ret = sk_detach_filter(tun->socket.sk);
1403 break;
1404
1405 default:
1406 ret = -EINVAL;
1407 break;
1408 }
1409
1410 unlock:
1411 rtnl_unlock();
1412 if (tun)
1413 tun_put(tun);
1414 return ret;
1415 }
1416
1417 static long tun_chr_ioctl(struct file *file,
1418 unsigned int cmd, unsigned long arg)
1419 {
1420 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
1421 }
1422
1423 #ifdef CONFIG_COMPAT
1424 static long tun_chr_compat_ioctl(struct file *file,
1425 unsigned int cmd, unsigned long arg)
1426 {
1427 switch (cmd) {
1428 case TUNSETIFF:
1429 case TUNGETIFF:
1430 case TUNSETTXFILTER:
1431 case TUNGETSNDBUF:
1432 case TUNSETSNDBUF:
1433 case SIOCGIFHWADDR:
1434 case SIOCSIFHWADDR:
1435 arg = (unsigned long)compat_ptr(arg);
1436 break;
1437 default:
1438 arg = (compat_ulong_t)arg;
1439 break;
1440 }
1441
1442 /*
1443 * compat_ifreq is shorter than ifreq, so we must not access beyond
1444 * the end of that structure. All fields that are used in this
1445 * driver are compatible though, we don't need to convert the
1446 * contents.
1447 */
1448 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
1449 }
1450 #endif /* CONFIG_COMPAT */
1451
1452 static int tun_chr_fasync(int fd, struct file *file, int on)
1453 {
1454 struct tun_struct *tun = tun_get(file);
1455 int ret;
1456
1457 if (!tun)
1458 return -EBADFD;
1459
1460 tun_debug(KERN_INFO, tun, "tun_chr_fasync %d\n", on);
1461
1462 if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
1463 goto out;
1464
1465 if (on) {
1466 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
1467 if (ret)
1468 goto out;
1469 tun->flags |= TUN_FASYNC;
1470 } else
1471 tun->flags &= ~TUN_FASYNC;
1472 ret = 0;
1473 out:
1474 tun_put(tun);
1475 return ret;
1476 }
1477
1478 static int tun_chr_open(struct inode *inode, struct file * file)
1479 {
1480 struct tun_file *tfile;
1481
1482 DBG1(KERN_INFO, "tunX: tun_chr_open\n");
1483
1484 tfile = kmalloc(sizeof(*tfile), GFP_KERNEL);
1485 if (!tfile)
1486 return -ENOMEM;
1487 atomic_set(&tfile->count, 0);
1488 tfile->tun = NULL;
1489 tfile->net = get_net(current->nsproxy->net_ns);
1490 file->private_data = tfile;
1491 return 0;
1492 }
1493
1494 static int tun_chr_close(struct inode *inode, struct file *file)
1495 {
1496 struct tun_file *tfile = file->private_data;
1497 struct tun_struct *tun;
1498
1499 tun = __tun_get(tfile);
1500 if (tun) {
1501 struct net_device *dev = tun->dev;
1502
1503 tun_debug(KERN_INFO, tun, "tun_chr_close\n");
1504
1505 __tun_detach(tun);
1506
1507 /* If desirable, unregister the netdevice. */
1508 if (!(tun->flags & TUN_PERSIST)) {
1509 rtnl_lock();
1510 if (dev->reg_state == NETREG_REGISTERED)
1511 unregister_netdevice(dev);
1512 rtnl_unlock();
1513 }
1514 }
1515
1516 tun = tfile->tun;
1517 if (tun)
1518 sock_put(tun->socket.sk);
1519
1520 put_net(tfile->net);
1521 kfree(tfile);
1522
1523 return 0;
1524 }
1525
1526 static const struct file_operations tun_fops = {
1527 .owner = THIS_MODULE,
1528 .llseek = no_llseek,
1529 .read = do_sync_read,
1530 .aio_read = tun_chr_aio_read,
1531 .write = do_sync_write,
1532 .aio_write = tun_chr_aio_write,
1533 .poll = tun_chr_poll,
1534 .unlocked_ioctl = tun_chr_ioctl,
1535 #ifdef CONFIG_COMPAT
1536 .compat_ioctl = tun_chr_compat_ioctl,
1537 #endif
1538 .open = tun_chr_open,
1539 .release = tun_chr_close,
1540 .fasync = tun_chr_fasync
1541 };
1542
1543 static struct miscdevice tun_miscdev = {
1544 .minor = TUN_MINOR,
1545 .name = "tun",
1546 .nodename = "net/tun",
1547 .fops = &tun_fops,
1548 };
1549
1550 /* ethtool interface */
1551
1552 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1553 {
1554 cmd->supported = 0;
1555 cmd->advertising = 0;
1556 cmd->speed = SPEED_10;
1557 cmd->duplex = DUPLEX_FULL;
1558 cmd->port = PORT_TP;
1559 cmd->phy_address = 0;
1560 cmd->transceiver = XCVR_INTERNAL;
1561 cmd->autoneg = AUTONEG_DISABLE;
1562 cmd->maxtxpkt = 0;
1563 cmd->maxrxpkt = 0;
1564 return 0;
1565 }
1566
1567 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
1568 {
1569 struct tun_struct *tun = netdev_priv(dev);
1570
1571 strcpy(info->driver, DRV_NAME);
1572 strcpy(info->version, DRV_VERSION);
1573 strcpy(info->fw_version, "N/A");
1574
1575 switch (tun->flags & TUN_TYPE_MASK) {
1576 case TUN_TUN_DEV:
1577 strcpy(info->bus_info, "tun");
1578 break;
1579 case TUN_TAP_DEV:
1580 strcpy(info->bus_info, "tap");
1581 break;
1582 }
1583 }
1584
1585 static u32 tun_get_msglevel(struct net_device *dev)
1586 {
1587 #ifdef TUN_DEBUG
1588 struct tun_struct *tun = netdev_priv(dev);
1589 return tun->debug;
1590 #else
1591 return -EOPNOTSUPP;
1592 #endif
1593 }
1594
1595 static void tun_set_msglevel(struct net_device *dev, u32 value)
1596 {
1597 #ifdef TUN_DEBUG
1598 struct tun_struct *tun = netdev_priv(dev);
1599 tun->debug = value;
1600 #endif
1601 }
1602
1603 static const struct ethtool_ops tun_ethtool_ops = {
1604 .get_settings = tun_get_settings,
1605 .get_drvinfo = tun_get_drvinfo,
1606 .get_msglevel = tun_get_msglevel,
1607 .set_msglevel = tun_set_msglevel,
1608 .get_link = ethtool_op_get_link,
1609 };
1610
1611
1612 static int __init tun_init(void)
1613 {
1614 int ret = 0;
1615
1616 pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
1617 pr_info("%s\n", DRV_COPYRIGHT);
1618
1619 ret = rtnl_link_register(&tun_link_ops);
1620 if (ret) {
1621 pr_err("Can't register link_ops\n");
1622 goto err_linkops;
1623 }
1624
1625 ret = misc_register(&tun_miscdev);
1626 if (ret) {
1627 pr_err("Can't register misc device %d\n", TUN_MINOR);
1628 goto err_misc;
1629 }
1630 return 0;
1631 err_misc:
1632 rtnl_link_unregister(&tun_link_ops);
1633 err_linkops:
1634 return ret;
1635 }
1636
1637 static void tun_cleanup(void)
1638 {
1639 misc_deregister(&tun_miscdev);
1640 rtnl_link_unregister(&tun_link_ops);
1641 }
1642
1643 /* Get an underlying socket object from tun file. Returns error unless file is
1644 * attached to a device. The returned object works like a packet socket, it
1645 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
1646 * holding a reference to the file for as long as the socket is in use. */
1647 struct socket *tun_get_socket(struct file *file)
1648 {
1649 struct tun_struct *tun;
1650 if (file->f_op != &tun_fops)
1651 return ERR_PTR(-EINVAL);
1652 tun = tun_get(file);
1653 if (!tun)
1654 return ERR_PTR(-EBADFD);
1655 tun_put(tun);
1656 return &tun->socket;
1657 }
1658 EXPORT_SYMBOL_GPL(tun_get_socket);
1659
1660 module_init(tun_init);
1661 module_exit(tun_cleanup);
1662 MODULE_DESCRIPTION(DRV_DESCRIPTION);
1663 MODULE_AUTHOR(DRV_COPYRIGHT);
1664 MODULE_LICENSE("GPL");
1665 MODULE_ALIAS_MISCDEV(TUN_MINOR);
1666 MODULE_ALIAS("devname:net/tun");
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