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staging/mei: add mei to staging Kbuild
[zen-stable.git] / drivers / net / tun.c
blobf5e9ac00a07bdd95040d9e8f47903f55c46c708e
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 struct fasync_struct *fasync;
127
128 struct tap_filter txflt;
129 struct socket socket;
130 struct socket_wq wq;
131
132 int vnet_hdr_sz;
133
134 #ifdef TUN_DEBUG
135 int debug;
136 #endif
137 };
138
139 struct tun_sock {
140 struct sock sk;
141 struct tun_struct *tun;
142 };
143
144 static inline struct tun_sock *tun_sk(struct sock *sk)
145 {
146 return container_of(sk, struct tun_sock, sk);
147 }
148
149 static int tun_attach(struct tun_struct *tun, struct file *file)
150 {
151 struct tun_file *tfile = file->private_data;
152 int err;
153
154 ASSERT_RTNL();
155
156 netif_tx_lock_bh(tun->dev);
157
158 err = -EINVAL;
159 if (tfile->tun)
160 goto out;
161
162 err = -EBUSY;
163 if (tun->tfile)
164 goto out;
165
166 err = 0;
167 tfile->tun = tun;
168 tun->tfile = tfile;
169 tun->socket.file = file;
170 netif_carrier_on(tun->dev);
171 dev_hold(tun->dev);
172 sock_hold(tun->socket.sk);
173 atomic_inc(&tfile->count);
174
175 out:
176 netif_tx_unlock_bh(tun->dev);
177 return err;
178 }
179
180 static void __tun_detach(struct tun_struct *tun)
181 {
182 /* Detach from net device */
183 netif_tx_lock_bh(tun->dev);
184 netif_carrier_off(tun->dev);
185 tun->tfile = NULL;
186 tun->socket.file = NULL;
187 netif_tx_unlock_bh(tun->dev);
188
189 /* Drop read queue */
190 skb_queue_purge(&tun->socket.sk->sk_receive_queue);
191
192 /* Drop the extra count on the net device */
193 dev_put(tun->dev);
194 }
195
196 static void tun_detach(struct tun_struct *tun)
197 {
198 rtnl_lock();
199 __tun_detach(tun);
200 rtnl_unlock();
201 }
202
203 static struct tun_struct *__tun_get(struct tun_file *tfile)
204 {
205 struct tun_struct *tun = NULL;
206
207 if (atomic_inc_not_zero(&tfile->count))
208 tun = tfile->tun;
209
210 return tun;
211 }
212
213 static struct tun_struct *tun_get(struct file *file)
214 {
215 return __tun_get(file->private_data);
216 }
217
218 static void tun_put(struct tun_struct *tun)
219 {
220 struct tun_file *tfile = tun->tfile;
221
222 if (atomic_dec_and_test(&tfile->count))
223 tun_detach(tfile->tun);
224 }
225
226 /* TAP filtering */
227 static void addr_hash_set(u32 *mask, const u8 *addr)
228 {
229 int n = ether_crc(ETH_ALEN, addr) >> 26;
230 mask[n >> 5] |= (1 << (n & 31));
231 }
232
233 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
234 {
235 int n = ether_crc(ETH_ALEN, addr) >> 26;
236 return mask[n >> 5] & (1 << (n & 31));
237 }
238
239 static int update_filter(struct tap_filter *filter, void __user *arg)
240 {
241 struct { u8 u[ETH_ALEN]; } *addr;
242 struct tun_filter uf;
243 int err, alen, n, nexact;
244
245 if (copy_from_user(&uf, arg, sizeof(uf)))
246 return -EFAULT;
247
248 if (!uf.count) {
249 /* Disabled */
250 filter->count = 0;
251 return 0;
252 }
253
254 alen = ETH_ALEN * uf.count;
255 addr = kmalloc(alen, GFP_KERNEL);
256 if (!addr)
257 return -ENOMEM;
258
259 if (copy_from_user(addr, arg + sizeof(uf), alen)) {
260 err = -EFAULT;
261 goto done;
262 }
263
264 /* The filter is updated without holding any locks. Which is
265 * perfectly safe. We disable it first and in the worst
266 * case we'll accept a few undesired packets. */
267 filter->count = 0;
268 wmb();
269
270 /* Use first set of addresses as an exact filter */
271 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
272 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
273
274 nexact = n;
275
276 /* Remaining multicast addresses are hashed,
277 * unicast will leave the filter disabled. */
278 memset(filter->mask, 0, sizeof(filter->mask));
279 for (; n < uf.count; n++) {
280 if (!is_multicast_ether_addr(addr[n].u)) {
281 err = 0; /* no filter */
282 goto done;
283 }
284 addr_hash_set(filter->mask, addr[n].u);
285 }
286
287 /* For ALLMULTI just set the mask to all ones.
288 * This overrides the mask populated above. */
289 if ((uf.flags & TUN_FLT_ALLMULTI))
290 memset(filter->mask, ~0, sizeof(filter->mask));
291
292 /* Now enable the filter */
293 wmb();
294 filter->count = nexact;
295
296 /* Return the number of exact filters */
297 err = nexact;
298
299 done:
300 kfree(addr);
301 return err;
302 }
303
304 /* Returns: 0 - drop, !=0 - accept */
305 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
306 {
307 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
308 * at this point. */
309 struct ethhdr *eh = (struct ethhdr *) skb->data;
310 int i;
311
312 /* Exact match */
313 for (i = 0; i < filter->count; i++)
314 if (!compare_ether_addr(eh->h_dest, filter->addr[i]))
315 return 1;
316
317 /* Inexact match (multicast only) */
318 if (is_multicast_ether_addr(eh->h_dest))
319 return addr_hash_test(filter->mask, eh->h_dest);
320
321 return 0;
322 }
323
324 /*
325 * Checks whether the packet is accepted or not.
326 * Returns: 0 - drop, !=0 - accept
327 */
328 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
329 {
330 if (!filter->count)
331 return 1;
332
333 return run_filter(filter, skb);
334 }
335
336 /* Network device part of the driver */
337
338 static const struct ethtool_ops tun_ethtool_ops;
339
340 /* Net device detach from fd. */
341 static void tun_net_uninit(struct net_device *dev)
342 {
343 struct tun_struct *tun = netdev_priv(dev);
344 struct tun_file *tfile = tun->tfile;
345
346 /* Inform the methods they need to stop using the dev.
347 */
348 if (tfile) {
349 wake_up_all(&tun->wq.wait);
350 if (atomic_dec_and_test(&tfile->count))
351 __tun_detach(tun);
352 }
353 }
354
355 static void tun_free_netdev(struct net_device *dev)
356 {
357 struct tun_struct *tun = netdev_priv(dev);
358
359 sock_put(tun->socket.sk);
360 }
361
362 /* Net device open. */
363 static int tun_net_open(struct net_device *dev)
364 {
365 netif_start_queue(dev);
366 return 0;
367 }
368
369 /* Net device close. */
370 static int tun_net_close(struct net_device *dev)
371 {
372 netif_stop_queue(dev);
373 return 0;
374 }
375
376 /* Net device start xmit */
377 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
378 {
379 struct tun_struct *tun = netdev_priv(dev);
380
381 tun_debug(KERN_INFO, tun, "tun_net_xmit %d\n", skb->len);
382
383 /* Drop packet if interface is not attached */
384 if (!tun->tfile)
385 goto drop;
386
387 /* Drop if the filter does not like it.
388 * This is a noop if the filter is disabled.
389 * Filter can be enabled only for the TAP devices. */
390 if (!check_filter(&tun->txflt, skb))
391 goto drop;
392
393 if (tun->socket.sk->sk_filter &&
394 sk_filter(tun->socket.sk, skb))
395 goto drop;
396
397 if (skb_queue_len(&tun->socket.sk->sk_receive_queue) >= dev->tx_queue_len) {
398 if (!(tun->flags & TUN_ONE_QUEUE)) {
399 /* Normal queueing mode. */
400 /* Packet scheduler handles dropping of further packets. */
401 netif_stop_queue(dev);
402
403 /* We won't see all dropped packets individually, so overrun
404 * error is more appropriate. */
405 dev->stats.tx_fifo_errors++;
406 } else {
407 /* Single queue mode.
408 * Driver handles dropping of all packets itself. */
409 goto drop;
410 }
411 }
412
413 /* Orphan the skb - required as we might hang on to it
414 * for indefinite time. */
415 skb_orphan(skb);
416
417 /* Enqueue packet */
418 skb_queue_tail(&tun->socket.sk->sk_receive_queue, skb);
419
420 /* Notify and wake up reader process */
421 if (tun->flags & TUN_FASYNC)
422 kill_fasync(&tun->fasync, SIGIO, POLL_IN);
423 wake_up_interruptible_poll(&tun->wq.wait, POLLIN |
424 POLLRDNORM | POLLRDBAND);
425 return NETDEV_TX_OK;
426
427 drop:
428 dev->stats.tx_dropped++;
429 kfree_skb(skb);
430 return NETDEV_TX_OK;
431 }
432
433 static void tun_net_mclist(struct net_device *dev)
434 {
435 /*
436 * This callback is supposed to deal with mc filter in
437 * _rx_ path and has nothing to do with the _tx_ path.
438 * In rx path we always accept everything userspace gives us.
439 */
440 }
441
442 #define MIN_MTU 68
443 #define MAX_MTU 65535
444
445 static int
446 tun_net_change_mtu(struct net_device *dev, int new_mtu)
447 {
448 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
449 return -EINVAL;
450 dev->mtu = new_mtu;
451 return 0;
452 }
453
454 static const struct net_device_ops tun_netdev_ops = {
455 .ndo_uninit = tun_net_uninit,
456 .ndo_open = tun_net_open,
457 .ndo_stop = tun_net_close,
458 .ndo_start_xmit = tun_net_xmit,
459 .ndo_change_mtu = tun_net_change_mtu,
460 };
461
462 static const struct net_device_ops tap_netdev_ops = {
463 .ndo_uninit = tun_net_uninit,
464 .ndo_open = tun_net_open,
465 .ndo_stop = tun_net_close,
466 .ndo_start_xmit = tun_net_xmit,
467 .ndo_change_mtu = tun_net_change_mtu,
468 .ndo_set_multicast_list = tun_net_mclist,
469 .ndo_set_mac_address = eth_mac_addr,
470 .ndo_validate_addr = eth_validate_addr,
471 };
472
473 /* Initialize net device. */
474 static void tun_net_init(struct net_device *dev)
475 {
476 struct tun_struct *tun = netdev_priv(dev);
477
478 switch (tun->flags & TUN_TYPE_MASK) {
479 case TUN_TUN_DEV:
480 dev->netdev_ops = &tun_netdev_ops;
481
482 /* Point-to-Point TUN Device */
483 dev->hard_header_len = 0;
484 dev->addr_len = 0;
485 dev->mtu = 1500;
486
487 /* Zero header length */
488 dev->type = ARPHRD_NONE;
489 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
490 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
491 break;
492
493 case TUN_TAP_DEV:
494 dev->netdev_ops = &tap_netdev_ops;
495 /* Ethernet TAP Device */
496 ether_setup(dev);
497
498 random_ether_addr(dev->dev_addr);
499
500 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
501 break;
502 }
503 }
504
505 /* Character device part */
506
507 /* Poll */
508 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
509 {
510 struct tun_file *tfile = file->private_data;
511 struct tun_struct *tun = __tun_get(tfile);
512 struct sock *sk;
513 unsigned int mask = 0;
514
515 if (!tun)
516 return POLLERR;
517
518 sk = tun->socket.sk;
519
520 tun_debug(KERN_INFO, tun, "tun_chr_poll\n");
521
522 poll_wait(file, &tun->wq.wait, wait);
523
524 if (!skb_queue_empty(&sk->sk_receive_queue))
525 mask |= POLLIN | POLLRDNORM;
526
527 if (sock_writeable(sk) ||
528 (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
529 sock_writeable(sk)))
530 mask |= POLLOUT | POLLWRNORM;
531
532 if (tun->dev->reg_state != NETREG_REGISTERED)
533 mask = POLLERR;
534
535 tun_put(tun);
536 return mask;
537 }
538
539 /* prepad is the amount to reserve at front. len is length after that.
540 * linear is a hint as to how much to copy (usually headers). */
541 static inline struct sk_buff *tun_alloc_skb(struct tun_struct *tun,
542 size_t prepad, size_t len,
543 size_t linear, int noblock)
544 {
545 struct sock *sk = tun->socket.sk;
546 struct sk_buff *skb;
547 int err;
548
549 sock_update_classid(sk);
550
551 /* Under a page? Don't bother with paged skb. */
552 if (prepad + len < PAGE_SIZE || !linear)
553 linear = len;
554
555 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
556 &err);
557 if (!skb)
558 return ERR_PTR(err);
559
560 skb_reserve(skb, prepad);
561 skb_put(skb, linear);
562 skb->data_len = len - linear;
563 skb->len += len - linear;
564
565 return skb;
566 }
567
568 /* Get packet from user space buffer */
569 static __inline__ ssize_t tun_get_user(struct tun_struct *tun,
570 const struct iovec *iv, size_t count,
571 int noblock)
572 {
573 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
574 struct sk_buff *skb;
575 size_t len = count, align = 0;
576 struct virtio_net_hdr gso = { 0 };
577 int offset = 0;
578
579 if (!(tun->flags & TUN_NO_PI)) {
580 if ((len -= sizeof(pi)) > count)
581 return -EINVAL;
582
583 if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
584 return -EFAULT;
585 offset += sizeof(pi);
586 }
587
588 if (tun->flags & TUN_VNET_HDR) {
589 if ((len -= tun->vnet_hdr_sz) > count)
590 return -EINVAL;
591
592 if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
593 return -EFAULT;
594
595 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
596 gso.csum_start + gso.csum_offset + 2 > gso.hdr_len)
597 gso.hdr_len = gso.csum_start + gso.csum_offset + 2;
598
599 if (gso.hdr_len > len)
600 return -EINVAL;
601 offset += tun->vnet_hdr_sz;
602 }
603
604 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
605 align = NET_IP_ALIGN;
606 if (unlikely(len < ETH_HLEN ||
607 (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
608 return -EINVAL;
609 }
610
611 skb = tun_alloc_skb(tun, align, len, gso.hdr_len, noblock);
612 if (IS_ERR(skb)) {
613 if (PTR_ERR(skb) != -EAGAIN)
614 tun->dev->stats.rx_dropped++;
615 return PTR_ERR(skb);
616 }
617
618 if (skb_copy_datagram_from_iovec(skb, 0, iv, offset, len)) {
619 tun->dev->stats.rx_dropped++;
620 kfree_skb(skb);
621 return -EFAULT;
622 }
623
624 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
625 if (!skb_partial_csum_set(skb, gso.csum_start,
626 gso.csum_offset)) {
627 tun->dev->stats.rx_frame_errors++;
628 kfree_skb(skb);
629 return -EINVAL;
630 }
631 } else if (tun->flags & TUN_NOCHECKSUM)
632 skb->ip_summed = CHECKSUM_UNNECESSARY;
633
634 switch (tun->flags & TUN_TYPE_MASK) {
635 case TUN_TUN_DEV:
636 if (tun->flags & TUN_NO_PI) {
637 switch (skb->data[0] & 0xf0) {
638 case 0x40:
639 pi.proto = htons(ETH_P_IP);
640 break;
641 case 0x60:
642 pi.proto = htons(ETH_P_IPV6);
643 break;
644 default:
645 tun->dev->stats.rx_dropped++;
646 kfree_skb(skb);
647 return -EINVAL;
648 }
649 }
650
651 skb_reset_mac_header(skb);
652 skb->protocol = pi.proto;
653 skb->dev = tun->dev;
654 break;
655 case TUN_TAP_DEV:
656 skb->protocol = eth_type_trans(skb, tun->dev);
657 break;
658 };
659
660 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
661 pr_debug("GSO!\n");
662 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
663 case VIRTIO_NET_HDR_GSO_TCPV4:
664 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
665 break;
666 case VIRTIO_NET_HDR_GSO_TCPV6:
667 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
668 break;
669 case VIRTIO_NET_HDR_GSO_UDP:
670 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
671 break;
672 default:
673 tun->dev->stats.rx_frame_errors++;
674 kfree_skb(skb);
675 return -EINVAL;
676 }
677
678 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
679 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
680
681 skb_shinfo(skb)->gso_size = gso.gso_size;
682 if (skb_shinfo(skb)->gso_size == 0) {
683 tun->dev->stats.rx_frame_errors++;
684 kfree_skb(skb);
685 return -EINVAL;
686 }
687
688 /* Header must be checked, and gso_segs computed. */
689 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
690 skb_shinfo(skb)->gso_segs = 0;
691 }
692
693 netif_rx_ni(skb);
694
695 tun->dev->stats.rx_packets++;
696 tun->dev->stats.rx_bytes += len;
697
698 return count;
699 }
700
701 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
702 unsigned long count, loff_t pos)
703 {
704 struct file *file = iocb->ki_filp;
705 struct tun_struct *tun = tun_get(file);
706 ssize_t result;
707
708 if (!tun)
709 return -EBADFD;
710
711 tun_debug(KERN_INFO, tun, "tun_chr_write %ld\n", count);
712
713 result = tun_get_user(tun, iv, iov_length(iv, count),
714 file->f_flags & O_NONBLOCK);
715
716 tun_put(tun);
717 return result;
718 }
719
720 /* Put packet to the user space buffer */
721 static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
722 struct sk_buff *skb,
723 const struct iovec *iv, int len)
724 {
725 struct tun_pi pi = { 0, skb->protocol };
726 ssize_t total = 0;
727
728 if (!(tun->flags & TUN_NO_PI)) {
729 if ((len -= sizeof(pi)) < 0)
730 return -EINVAL;
731
732 if (len < skb->len) {
733 /* Packet will be striped */
734 pi.flags |= TUN_PKT_STRIP;
735 }
736
737 if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi)))
738 return -EFAULT;
739 total += sizeof(pi);
740 }
741
742 if (tun->flags & TUN_VNET_HDR) {
743 struct virtio_net_hdr gso = { 0 }; /* no info leak */
744 if ((len -= tun->vnet_hdr_sz) < 0)
745 return -EINVAL;
746
747 if (skb_is_gso(skb)) {
748 struct skb_shared_info *sinfo = skb_shinfo(skb);
749
750 /* This is a hint as to how much should be linear. */
751 gso.hdr_len = skb_headlen(skb);
752 gso.gso_size = sinfo->gso_size;
753 if (sinfo->gso_type & SKB_GSO_TCPV4)
754 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
755 else if (sinfo->gso_type & SKB_GSO_TCPV6)
756 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
757 else if (sinfo->gso_type & SKB_GSO_UDP)
758 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
759 else {
760 pr_err("unexpected GSO type: "
761 "0x%x, gso_size %d, hdr_len %d\n",
762 sinfo->gso_type, gso.gso_size,
763 gso.hdr_len);
764 print_hex_dump(KERN_ERR, "tun: ",
765 DUMP_PREFIX_NONE,
766 16, 1, skb->head,
767 min((int)gso.hdr_len, 64), true);
768 WARN_ON_ONCE(1);
769 return -EINVAL;
770 }
771 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
772 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
773 } else
774 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
775
776 if (skb->ip_summed == CHECKSUM_PARTIAL) {
777 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
778 gso.csum_start = skb_checksum_start_offset(skb);
779 gso.csum_offset = skb->csum_offset;
780 } /* else everything is zero */
781
782 if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
783 sizeof(gso))))
784 return -EFAULT;
785 total += tun->vnet_hdr_sz;
786 }
787
788 len = min_t(int, skb->len, len);
789
790 skb_copy_datagram_const_iovec(skb, 0, iv, total, len);
791 total += skb->len;
792
793 tun->dev->stats.tx_packets++;
794 tun->dev->stats.tx_bytes += len;
795
796 return total;
797 }
798
799 static ssize_t tun_do_read(struct tun_struct *tun,
800 struct kiocb *iocb, const struct iovec *iv,
801 ssize_t len, int noblock)
802 {
803 DECLARE_WAITQUEUE(wait, current);
804 struct sk_buff *skb;
805 ssize_t ret = 0;
806
807 tun_debug(KERN_INFO, tun, "tun_chr_read\n");
808
809 add_wait_queue(&tun->wq.wait, &wait);
810 while (len) {
811 current->state = TASK_INTERRUPTIBLE;
812
813 /* Read frames from the queue */
814 if (!(skb=skb_dequeue(&tun->socket.sk->sk_receive_queue))) {
815 if (noblock) {
816 ret = -EAGAIN;
817 break;
818 }
819 if (signal_pending(current)) {
820 ret = -ERESTARTSYS;
821 break;
822 }
823 if (tun->dev->reg_state != NETREG_REGISTERED) {
824 ret = -EIO;
825 break;
826 }
827
828 /* Nothing to read, let's sleep */
829 schedule();
830 continue;
831 }
832 netif_wake_queue(tun->dev);
833
834 ret = tun_put_user(tun, skb, iv, len);
835 kfree_skb(skb);
836 break;
837 }
838
839 current->state = TASK_RUNNING;
840 remove_wait_queue(&tun->wq.wait, &wait);
841
842 return ret;
843 }
844
845 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
846 unsigned long count, loff_t pos)
847 {
848 struct file *file = iocb->ki_filp;
849 struct tun_file *tfile = file->private_data;
850 struct tun_struct *tun = __tun_get(tfile);
851 ssize_t len, ret;
852
853 if (!tun)
854 return -EBADFD;
855 len = iov_length(iv, count);
856 if (len < 0) {
857 ret = -EINVAL;
858 goto out;
859 }
860
861 ret = tun_do_read(tun, iocb, iv, len, file->f_flags & O_NONBLOCK);
862 ret = min_t(ssize_t, ret, len);
863 out:
864 tun_put(tun);
865 return ret;
866 }
867
868 static void tun_setup(struct net_device *dev)
869 {
870 struct tun_struct *tun = netdev_priv(dev);
871
872 tun->owner = -1;
873 tun->group = -1;
874
875 dev->ethtool_ops = &tun_ethtool_ops;
876 dev->destructor = tun_free_netdev;
877 }
878
879 /* Trivial set of netlink ops to allow deleting tun or tap
880 * device with netlink.
881 */
882 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
883 {
884 return -EINVAL;
885 }
886
887 static struct rtnl_link_ops tun_link_ops __read_mostly = {
888 .kind = DRV_NAME,
889 .priv_size = sizeof(struct tun_struct),
890 .setup = tun_setup,
891 .validate = tun_validate,
892 };
893
894 static void tun_sock_write_space(struct sock *sk)
895 {
896 struct tun_struct *tun;
897 wait_queue_head_t *wqueue;
898
899 if (!sock_writeable(sk))
900 return;
901
902 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
903 return;
904
905 wqueue = sk_sleep(sk);
906 if (wqueue && waitqueue_active(wqueue))
907 wake_up_interruptible_sync_poll(wqueue, POLLOUT |
908 POLLWRNORM | POLLWRBAND);
909
910 tun = tun_sk(sk)->tun;
911 kill_fasync(&tun->fasync, SIGIO, POLL_OUT);
912 }
913
914 static void tun_sock_destruct(struct sock *sk)
915 {
916 free_netdev(tun_sk(sk)->tun->dev);
917 }
918
919 static int tun_sendmsg(struct kiocb *iocb, struct socket *sock,
920 struct msghdr *m, size_t total_len)
921 {
922 struct tun_struct *tun = container_of(sock, struct tun_struct, socket);
923 return tun_get_user(tun, m->msg_iov, total_len,
924 m->msg_flags & MSG_DONTWAIT);
925 }
926
927 static int tun_recvmsg(struct kiocb *iocb, struct socket *sock,
928 struct msghdr *m, size_t total_len,
929 int flags)
930 {
931 struct tun_struct *tun = container_of(sock, struct tun_struct, socket);
932 int ret;
933 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC))
934 return -EINVAL;
935 ret = tun_do_read(tun, iocb, m->msg_iov, total_len,
936 flags & MSG_DONTWAIT);
937 if (ret > total_len) {
938 m->msg_flags |= MSG_TRUNC;
939 ret = flags & MSG_TRUNC ? ret : total_len;
940 }
941 return ret;
942 }
943
944 /* Ops structure to mimic raw sockets with tun */
945 static const struct proto_ops tun_socket_ops = {
946 .sendmsg = tun_sendmsg,
947 .recvmsg = tun_recvmsg,
948 };
949
950 static struct proto tun_proto = {
951 .name = "tun",
952 .owner = THIS_MODULE,
953 .obj_size = sizeof(struct tun_sock),
954 };
955
956 static int tun_flags(struct tun_struct *tun)
957 {
958 int flags = 0;
959
960 if (tun->flags & TUN_TUN_DEV)
961 flags |= IFF_TUN;
962 else
963 flags |= IFF_TAP;
964
965 if (tun->flags & TUN_NO_PI)
966 flags |= IFF_NO_PI;
967
968 if (tun->flags & TUN_ONE_QUEUE)
969 flags |= IFF_ONE_QUEUE;
970
971 if (tun->flags & TUN_VNET_HDR)
972 flags |= IFF_VNET_HDR;
973
974 return flags;
975 }
976
977 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
978 char *buf)
979 {
980 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
981 return sprintf(buf, "0x%x\n", tun_flags(tun));
982 }
983
984 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
985 char *buf)
986 {
987 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
988 return sprintf(buf, "%d\n", tun->owner);
989 }
990
991 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
992 char *buf)
993 {
994 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
995 return sprintf(buf, "%d\n", tun->group);
996 }
997
998 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
999 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
1000 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
1001
1002 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
1003 {
1004 struct sock *sk;
1005 struct tun_struct *tun;
1006 struct net_device *dev;
1007 int err;
1008
1009 dev = __dev_get_by_name(net, ifr->ifr_name);
1010 if (dev) {
1011 const struct cred *cred = current_cred();
1012
1013 if (ifr->ifr_flags & IFF_TUN_EXCL)
1014 return -EBUSY;
1015 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
1016 tun = netdev_priv(dev);
1017 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
1018 tun = netdev_priv(dev);
1019 else
1020 return -EINVAL;
1021
1022 if (((tun->owner != -1 && cred->euid != tun->owner) ||
1023 (tun->group != -1 && !in_egroup_p(tun->group))) &&
1024 !capable(CAP_NET_ADMIN))
1025 return -EPERM;
1026 err = security_tun_dev_attach(tun->socket.sk);
1027 if (err < 0)
1028 return err;
1029
1030 err = tun_attach(tun, file);
1031 if (err < 0)
1032 return err;
1033 }
1034 else {
1035 char *name;
1036 unsigned long flags = 0;
1037
1038 if (!capable(CAP_NET_ADMIN))
1039 return -EPERM;
1040 err = security_tun_dev_create();
1041 if (err < 0)
1042 return err;
1043
1044 /* Set dev type */
1045 if (ifr->ifr_flags & IFF_TUN) {
1046 /* TUN device */
1047 flags |= TUN_TUN_DEV;
1048 name = "tun%d";
1049 } else if (ifr->ifr_flags & IFF_TAP) {
1050 /* TAP device */
1051 flags |= TUN_TAP_DEV;
1052 name = "tap%d";
1053 } else
1054 return -EINVAL;
1055
1056 if (*ifr->ifr_name)
1057 name = ifr->ifr_name;
1058
1059 dev = alloc_netdev(sizeof(struct tun_struct), name,
1060 tun_setup);
1061 if (!dev)
1062 return -ENOMEM;
1063
1064 dev_net_set(dev, net);
1065 dev->rtnl_link_ops = &tun_link_ops;
1066
1067 tun = netdev_priv(dev);
1068 tun->dev = dev;
1069 tun->flags = flags;
1070 tun->txflt.count = 0;
1071 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
1072
1073 err = -ENOMEM;
1074 sk = sk_alloc(net, AF_UNSPEC, GFP_KERNEL, &tun_proto);
1075 if (!sk)
1076 goto err_free_dev;
1077
1078 tun->socket.wq = &tun->wq;
1079 init_waitqueue_head(&tun->wq.wait);
1080 tun->socket.ops = &tun_socket_ops;
1081 sock_init_data(&tun->socket, sk);
1082 sk->sk_write_space = tun_sock_write_space;
1083 sk->sk_sndbuf = INT_MAX;
1084
1085 tun_sk(sk)->tun = tun;
1086
1087 security_tun_dev_post_create(sk);
1088
1089 tun_net_init(dev);
1090
1091 if (strchr(dev->name, '%')) {
1092 err = dev_alloc_name(dev, dev->name);
1093 if (err < 0)
1094 goto err_free_sk;
1095 }
1096
1097 err = register_netdevice(tun->dev);
1098 if (err < 0)
1099 goto err_free_sk;
1100
1101 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
1102 device_create_file(&tun->dev->dev, &dev_attr_owner) ||
1103 device_create_file(&tun->dev->dev, &dev_attr_group))
1104 pr_err("Failed to create tun sysfs files\n");
1105
1106 sk->sk_destruct = tun_sock_destruct;
1107
1108 err = tun_attach(tun, file);
1109 if (err < 0)
1110 goto failed;
1111 }
1112
1113 tun_debug(KERN_INFO, tun, "tun_set_iff\n");
1114
1115 if (ifr->ifr_flags & IFF_NO_PI)
1116 tun->flags |= TUN_NO_PI;
1117 else
1118 tun->flags &= ~TUN_NO_PI;
1119
1120 if (ifr->ifr_flags & IFF_ONE_QUEUE)
1121 tun->flags |= TUN_ONE_QUEUE;
1122 else
1123 tun->flags &= ~TUN_ONE_QUEUE;
1124
1125 if (ifr->ifr_flags & IFF_VNET_HDR)
1126 tun->flags |= TUN_VNET_HDR;
1127 else
1128 tun->flags &= ~TUN_VNET_HDR;
1129
1130 /* Make sure persistent devices do not get stuck in
1131 * xoff state.
1132 */
1133 if (netif_running(tun->dev))
1134 netif_wake_queue(tun->dev);
1135
1136 strcpy(ifr->ifr_name, tun->dev->name);
1137 return 0;
1138
1139 err_free_sk:
1140 sock_put(sk);
1141 err_free_dev:
1142 free_netdev(dev);
1143 failed:
1144 return err;
1145 }
1146
1147 static int tun_get_iff(struct net *net, struct tun_struct *tun,
1148 struct ifreq *ifr)
1149 {
1150 tun_debug(KERN_INFO, tun, "tun_get_iff\n");
1151
1152 strcpy(ifr->ifr_name, tun->dev->name);
1153
1154 ifr->ifr_flags = tun_flags(tun);
1155
1156 return 0;
1157 }
1158
1159 /* This is like a cut-down ethtool ops, except done via tun fd so no
1160 * privs required. */
1161 static int set_offload(struct net_device *dev, unsigned long arg)
1162 {
1163 u32 old_features, features;
1164
1165 old_features = dev->features;
1166 /* Unset features, set them as we chew on the arg. */
1167 features = (old_features & ~(NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST
1168 |NETIF_F_TSO_ECN|NETIF_F_TSO|NETIF_F_TSO6
1169 |NETIF_F_UFO));
1170
1171 if (arg & TUN_F_CSUM) {
1172 features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1173 arg &= ~TUN_F_CSUM;
1174
1175 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1176 if (arg & TUN_F_TSO_ECN) {
1177 features |= NETIF_F_TSO_ECN;
1178 arg &= ~TUN_F_TSO_ECN;
1179 }
1180 if (arg & TUN_F_TSO4)
1181 features |= NETIF_F_TSO;
1182 if (arg & TUN_F_TSO6)
1183 features |= NETIF_F_TSO6;
1184 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1185 }
1186
1187 if (arg & TUN_F_UFO) {
1188 features |= NETIF_F_UFO;
1189 arg &= ~TUN_F_UFO;
1190 }
1191 }
1192
1193 /* This gives the user a way to test for new features in future by
1194 * trying to set them. */
1195 if (arg)
1196 return -EINVAL;
1197
1198 dev->features = features;
1199 if (old_features != dev->features)
1200 netdev_features_change(dev);
1201
1202 return 0;
1203 }
1204
1205 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
1206 unsigned long arg, int ifreq_len)
1207 {
1208 struct tun_file *tfile = file->private_data;
1209 struct tun_struct *tun;
1210 void __user* argp = (void __user*)arg;
1211 struct sock_fprog fprog;
1212 struct ifreq ifr;
1213 int sndbuf;
1214 int vnet_hdr_sz;
1215 int ret;
1216
1217 if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
1218 if (copy_from_user(&ifr, argp, ifreq_len))
1219 return -EFAULT;
1220
1221 if (cmd == TUNGETFEATURES) {
1222 /* Currently this just means: "what IFF flags are valid?".
1223 * This is needed because we never checked for invalid flags on
1224 * TUNSETIFF. */
1225 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
1226 IFF_VNET_HDR,
1227 (unsigned int __user*)argp);
1228 }
1229
1230 rtnl_lock();
1231
1232 tun = __tun_get(tfile);
1233 if (cmd == TUNSETIFF && !tun) {
1234 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1235
1236 ret = tun_set_iff(tfile->net, file, &ifr);
1237
1238 if (ret)
1239 goto unlock;
1240
1241 if (copy_to_user(argp, &ifr, ifreq_len))
1242 ret = -EFAULT;
1243 goto unlock;
1244 }
1245
1246 ret = -EBADFD;
1247 if (!tun)
1248 goto unlock;
1249
1250 tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %d\n", cmd);
1251
1252 ret = 0;
1253 switch (cmd) {
1254 case TUNGETIFF:
1255 ret = tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1256 if (ret)
1257 break;
1258
1259 if (copy_to_user(argp, &ifr, ifreq_len))
1260 ret = -EFAULT;
1261 break;
1262
1263 case TUNSETNOCSUM:
1264 /* Disable/Enable checksum */
1265 if (arg)
1266 tun->flags |= TUN_NOCHECKSUM;
1267 else
1268 tun->flags &= ~TUN_NOCHECKSUM;
1269
1270 tun_debug(KERN_INFO, tun, "checksum %s\n",
1271 arg ? "disabled" : "enabled");
1272 break;
1273
1274 case TUNSETPERSIST:
1275 /* Disable/Enable persist mode */
1276 if (arg)
1277 tun->flags |= TUN_PERSIST;
1278 else
1279 tun->flags &= ~TUN_PERSIST;
1280
1281 tun_debug(KERN_INFO, tun, "persist %s\n",
1282 arg ? "enabled" : "disabled");
1283 break;
1284
1285 case TUNSETOWNER:
1286 /* Set owner of the device */
1287 tun->owner = (uid_t) arg;
1288
1289 tun_debug(KERN_INFO, tun, "owner set to %d\n", tun->owner);
1290 break;
1291
1292 case TUNSETGROUP:
1293 /* Set group of the device */
1294 tun->group= (gid_t) arg;
1295
1296 tun_debug(KERN_INFO, tun, "group set to %d\n", tun->group);
1297 break;
1298
1299 case TUNSETLINK:
1300 /* Only allow setting the type when the interface is down */
1301 if (tun->dev->flags & IFF_UP) {
1302 tun_debug(KERN_INFO, tun,
1303 "Linktype set failed because interface is up\n");
1304 ret = -EBUSY;
1305 } else {
1306 tun->dev->type = (int) arg;
1307 tun_debug(KERN_INFO, tun, "linktype set to %d\n",
1308 tun->dev->type);
1309 ret = 0;
1310 }
1311 break;
1312
1313 #ifdef TUN_DEBUG
1314 case TUNSETDEBUG:
1315 tun->debug = arg;
1316 break;
1317 #endif
1318 case TUNSETOFFLOAD:
1319 ret = set_offload(tun->dev, arg);
1320 break;
1321
1322 case TUNSETTXFILTER:
1323 /* Can be set only for TAPs */
1324 ret = -EINVAL;
1325 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1326 break;
1327 ret = update_filter(&tun->txflt, (void __user *)arg);
1328 break;
1329
1330 case SIOCGIFHWADDR:
1331 /* Get hw address */
1332 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
1333 ifr.ifr_hwaddr.sa_family = tun->dev->type;
1334 if (copy_to_user(argp, &ifr, ifreq_len))
1335 ret = -EFAULT;
1336 break;
1337
1338 case SIOCSIFHWADDR:
1339 /* Set hw address */
1340 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n",
1341 ifr.ifr_hwaddr.sa_data);
1342
1343 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
1344 break;
1345
1346 case TUNGETSNDBUF:
1347 sndbuf = tun->socket.sk->sk_sndbuf;
1348 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
1349 ret = -EFAULT;
1350 break;
1351
1352 case TUNSETSNDBUF:
1353 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
1354 ret = -EFAULT;
1355 break;
1356 }
1357
1358 tun->socket.sk->sk_sndbuf = sndbuf;
1359 break;
1360
1361 case TUNGETVNETHDRSZ:
1362 vnet_hdr_sz = tun->vnet_hdr_sz;
1363 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
1364 ret = -EFAULT;
1365 break;
1366
1367 case TUNSETVNETHDRSZ:
1368 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
1369 ret = -EFAULT;
1370 break;
1371 }
1372 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
1373 ret = -EINVAL;
1374 break;
1375 }
1376
1377 tun->vnet_hdr_sz = vnet_hdr_sz;
1378 break;
1379
1380 case TUNATTACHFILTER:
1381 /* Can be set only for TAPs */
1382 ret = -EINVAL;
1383 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1384 break;
1385 ret = -EFAULT;
1386 if (copy_from_user(&fprog, argp, sizeof(fprog)))
1387 break;
1388
1389 ret = sk_attach_filter(&fprog, tun->socket.sk);
1390 break;
1391
1392 case TUNDETACHFILTER:
1393 /* Can be set only for TAPs */
1394 ret = -EINVAL;
1395 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1396 break;
1397 ret = sk_detach_filter(tun->socket.sk);
1398 break;
1399
1400 default:
1401 ret = -EINVAL;
1402 break;
1403 }
1404
1405 unlock:
1406 rtnl_unlock();
1407 if (tun)
1408 tun_put(tun);
1409 return ret;
1410 }
1411
1412 static long tun_chr_ioctl(struct file *file,
1413 unsigned int cmd, unsigned long arg)
1414 {
1415 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
1416 }
1417
1418 #ifdef CONFIG_COMPAT
1419 static long tun_chr_compat_ioctl(struct file *file,
1420 unsigned int cmd, unsigned long arg)
1421 {
1422 switch (cmd) {
1423 case TUNSETIFF:
1424 case TUNGETIFF:
1425 case TUNSETTXFILTER:
1426 case TUNGETSNDBUF:
1427 case TUNSETSNDBUF:
1428 case SIOCGIFHWADDR:
1429 case SIOCSIFHWADDR:
1430 arg = (unsigned long)compat_ptr(arg);
1431 break;
1432 default:
1433 arg = (compat_ulong_t)arg;
1434 break;
1435 }
1436
1437 /*
1438 * compat_ifreq is shorter than ifreq, so we must not access beyond
1439 * the end of that structure. All fields that are used in this
1440 * driver are compatible though, we don't need to convert the
1441 * contents.
1442 */
1443 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
1444 }
1445 #endif /* CONFIG_COMPAT */
1446
1447 static int tun_chr_fasync(int fd, struct file *file, int on)
1448 {
1449 struct tun_struct *tun = tun_get(file);
1450 int ret;
1451
1452 if (!tun)
1453 return -EBADFD;
1454
1455 tun_debug(KERN_INFO, tun, "tun_chr_fasync %d\n", on);
1456
1457 if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
1458 goto out;
1459
1460 if (on) {
1461 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
1462 if (ret)
1463 goto out;
1464 tun->flags |= TUN_FASYNC;
1465 } else
1466 tun->flags &= ~TUN_FASYNC;
1467 ret = 0;
1468 out:
1469 tun_put(tun);
1470 return ret;
1471 }
1472
1473 static int tun_chr_open(struct inode *inode, struct file * file)
1474 {
1475 struct tun_file *tfile;
1476
1477 DBG1(KERN_INFO, "tunX: tun_chr_open\n");
1478
1479 tfile = kmalloc(sizeof(*tfile), GFP_KERNEL);
1480 if (!tfile)
1481 return -ENOMEM;
1482 atomic_set(&tfile->count, 0);
1483 tfile->tun = NULL;
1484 tfile->net = get_net(current->nsproxy->net_ns);
1485 file->private_data = tfile;
1486 return 0;
1487 }
1488
1489 static int tun_chr_close(struct inode *inode, struct file *file)
1490 {
1491 struct tun_file *tfile = file->private_data;
1492 struct tun_struct *tun;
1493
1494 tun = __tun_get(tfile);
1495 if (tun) {
1496 struct net_device *dev = tun->dev;
1497
1498 tun_debug(KERN_INFO, tun, "tun_chr_close\n");
1499
1500 __tun_detach(tun);
1501
1502 /* If desirable, unregister the netdevice. */
1503 if (!(tun->flags & TUN_PERSIST)) {
1504 rtnl_lock();
1505 if (dev->reg_state == NETREG_REGISTERED)
1506 unregister_netdevice(dev);
1507 rtnl_unlock();
1508 }
1509 }
1510
1511 tun = tfile->tun;
1512 if (tun)
1513 sock_put(tun->socket.sk);
1514
1515 put_net(tfile->net);
1516 kfree(tfile);
1517
1518 return 0;
1519 }
1520
1521 static const struct file_operations tun_fops = {
1522 .owner = THIS_MODULE,
1523 .llseek = no_llseek,
1524 .read = do_sync_read,
1525 .aio_read = tun_chr_aio_read,
1526 .write = do_sync_write,
1527 .aio_write = tun_chr_aio_write,
1528 .poll = tun_chr_poll,
1529 .unlocked_ioctl = tun_chr_ioctl,
1530 #ifdef CONFIG_COMPAT
1531 .compat_ioctl = tun_chr_compat_ioctl,
1532 #endif
1533 .open = tun_chr_open,
1534 .release = tun_chr_close,
1535 .fasync = tun_chr_fasync
1536 };
1537
1538 static struct miscdevice tun_miscdev = {
1539 .minor = TUN_MINOR,
1540 .name = "tun",
1541 .nodename = "net/tun",
1542 .fops = &tun_fops,
1543 };
1544
1545 /* ethtool interface */
1546
1547 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1548 {
1549 cmd->supported = 0;
1550 cmd->advertising = 0;
1551 cmd->speed = SPEED_10;
1552 cmd->duplex = DUPLEX_FULL;
1553 cmd->port = PORT_TP;
1554 cmd->phy_address = 0;
1555 cmd->transceiver = XCVR_INTERNAL;
1556 cmd->autoneg = AUTONEG_DISABLE;
1557 cmd->maxtxpkt = 0;
1558 cmd->maxrxpkt = 0;
1559 return 0;
1560 }
1561
1562 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
1563 {
1564 struct tun_struct *tun = netdev_priv(dev);
1565
1566 strcpy(info->driver, DRV_NAME);
1567 strcpy(info->version, DRV_VERSION);
1568 strcpy(info->fw_version, "N/A");
1569
1570 switch (tun->flags & TUN_TYPE_MASK) {
1571 case TUN_TUN_DEV:
1572 strcpy(info->bus_info, "tun");
1573 break;
1574 case TUN_TAP_DEV:
1575 strcpy(info->bus_info, "tap");
1576 break;
1577 }
1578 }
1579
1580 static u32 tun_get_msglevel(struct net_device *dev)
1581 {
1582 #ifdef TUN_DEBUG
1583 struct tun_struct *tun = netdev_priv(dev);
1584 return tun->debug;
1585 #else
1586 return -EOPNOTSUPP;
1587 #endif
1588 }
1589
1590 static void tun_set_msglevel(struct net_device *dev, u32 value)
1591 {
1592 #ifdef TUN_DEBUG
1593 struct tun_struct *tun = netdev_priv(dev);
1594 tun->debug = value;
1595 #endif
1596 }
1597
1598 static u32 tun_get_rx_csum(struct net_device *dev)
1599 {
1600 struct tun_struct *tun = netdev_priv(dev);
1601 return (tun->flags & TUN_NOCHECKSUM) == 0;
1602 }
1603
1604 static int tun_set_rx_csum(struct net_device *dev, u32 data)
1605 {
1606 struct tun_struct *tun = netdev_priv(dev);
1607 if (data)
1608 tun->flags &= ~TUN_NOCHECKSUM;
1609 else
1610 tun->flags |= TUN_NOCHECKSUM;
1611 return 0;
1612 }
1613
1614 static const struct ethtool_ops tun_ethtool_ops = {
1615 .get_settings = tun_get_settings,
1616 .get_drvinfo = tun_get_drvinfo,
1617 .get_msglevel = tun_get_msglevel,
1618 .set_msglevel = tun_set_msglevel,
1619 .get_link = ethtool_op_get_link,
1620 .get_rx_csum = tun_get_rx_csum,
1621 .set_rx_csum = tun_set_rx_csum
1622 };
1623
1624
1625 static int __init tun_init(void)
1626 {
1627 int ret = 0;
1628
1629 pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
1630 pr_info("%s\n", DRV_COPYRIGHT);
1631
1632 ret = rtnl_link_register(&tun_link_ops);
1633 if (ret) {
1634 pr_err("Can't register link_ops\n");
1635 goto err_linkops;
1636 }
1637
1638 ret = misc_register(&tun_miscdev);
1639 if (ret) {
1640 pr_err("Can't register misc device %d\n", TUN_MINOR);
1641 goto err_misc;
1642 }
1643 return 0;
1644 err_misc:
1645 rtnl_link_unregister(&tun_link_ops);
1646 err_linkops:
1647 return ret;
1648 }
1649
1650 static void tun_cleanup(void)
1651 {
1652 misc_deregister(&tun_miscdev);
1653 rtnl_link_unregister(&tun_link_ops);
1654 }
1655
1656 /* Get an underlying socket object from tun file. Returns error unless file is
1657 * attached to a device. The returned object works like a packet socket, it
1658 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
1659 * holding a reference to the file for as long as the socket is in use. */
1660 struct socket *tun_get_socket(struct file *file)
1661 {
1662 struct tun_struct *tun;
1663 if (file->f_op != &tun_fops)
1664 return ERR_PTR(-EINVAL);
1665 tun = tun_get(file);
1666 if (!tun)
1667 return ERR_PTR(-EBADFD);
1668 tun_put(tun);
1669 return &tun->socket;
1670 }
1671 EXPORT_SYMBOL_GPL(tun_get_socket);
1672
1673 module_init(tun_init);
1674 module_exit(tun_cleanup);
1675 MODULE_DESCRIPTION(DRV_DESCRIPTION);
1676 MODULE_AUTHOR(DRV_COPYRIGHT);
1677 MODULE_LICENSE("GPL");
1678 MODULE_ALIAS_MISCDEV(TUN_MINOR);
1679 MODULE_ALIAS("devname:net/tun");