projects / deliverable / linux.git / blob
? search:


9a6b3824da146bdc8943eaba02b0e48ec5dac74c
[deliverable/linux.git] / drivers / net / tun.c
1 /*
2 * TUN - Universal TUN/TAP device driver.
3 * Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * $Id: tun.c,v 1.15 2002/03/01 02:44:24 maxk Exp $
16 */
17
18 /*
19 * Changes:
20 *
21 * Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14
22 * Add TUNSETLINK ioctl to set the link encapsulation
23 *
24 * Mark Smith <markzzzsmith@yahoo.com.au>
25 * Use random_ether_addr() for tap MAC address.
26 *
27 * Harald Roelle <harald.roelle@ifi.lmu.de> 2004/04/20
28 * Fixes in packet dropping, queue length setting and queue wakeup.
29 * Increased default tx queue length.
30 * Added ethtool API.
31 * Minor cleanups
32 *
33 * Daniel Podlejski <underley@underley.eu.org>
34 * Modifications for 2.3.99-pre5 kernel.
35 */
36
37 #define 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_multicast_list = 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
532 random_ether_addr(dev->dev_addr);
533
534 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
535 break;
536 }
537 }
538
539 /* Character device part */
540
541 /* Poll */
542 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
543 {
544 struct tun_file *tfile = file->private_data;
545 struct tun_struct *tun = __tun_get(tfile);
546 struct sock *sk;
547 unsigned int mask = 0;
548
549 if (!tun)
550 return POLLERR;
551
552 sk = tun->socket.sk;
553
554 tun_debug(KERN_INFO, tun, "tun_chr_poll\n");
555
556 poll_wait(file, &tun->wq.wait, wait);
557
558 if (!skb_queue_empty(&sk->sk_receive_queue))
559 mask |= POLLIN | POLLRDNORM;
560
561 if (sock_writeable(sk) ||
562 (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
563 sock_writeable(sk)))
564 mask |= POLLOUT | POLLWRNORM;
565
566 if (tun->dev->reg_state != NETREG_REGISTERED)
567 mask = POLLERR;
568
569 tun_put(tun);
570 return mask;
571 }
572
573 /* prepad is the amount to reserve at front. len is length after that.
574 * linear is a hint as to how much to copy (usually headers). */
575 static struct sk_buff *tun_alloc_skb(struct tun_struct *tun,
576 size_t prepad, size_t len,
577 size_t linear, int noblock)
578 {
579 struct sock *sk = tun->socket.sk;
580 struct sk_buff *skb;
581 int err;
582
583 sock_update_classid(sk);
584
585 /* Under a page? Don't bother with paged skb. */
586 if (prepad + len < PAGE_SIZE || !linear)
587 linear = len;
588
589 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
590 &err);
591 if (!skb)
592 return ERR_PTR(err);
593
594 skb_reserve(skb, prepad);
595 skb_put(skb, linear);
596 skb->data_len = len - linear;
597 skb->len += len - linear;
598
599 return skb;
600 }
601
602 /* Get packet from user space buffer */
603 static ssize_t tun_get_user(struct tun_struct *tun,
604 const struct iovec *iv, size_t count,
605 int noblock)
606 {
607 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
608 struct sk_buff *skb;
609 size_t len = count, align = NET_SKB_PAD;
610 struct virtio_net_hdr gso = { 0 };
611 int offset = 0;
612
613 if (!(tun->flags & TUN_NO_PI)) {
614 if ((len -= sizeof(pi)) > count)
615 return -EINVAL;
616
617 if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
618 return -EFAULT;
619 offset += sizeof(pi);
620 }
621
622 if (tun->flags & TUN_VNET_HDR) {
623 if ((len -= tun->vnet_hdr_sz) > count)
624 return -EINVAL;
625
626 if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
627 return -EFAULT;
628
629 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
630 gso.csum_start + gso.csum_offset + 2 > gso.hdr_len)
631 gso.hdr_len = gso.csum_start + gso.csum_offset + 2;
632
633 if (gso.hdr_len > len)
634 return -EINVAL;
635 offset += tun->vnet_hdr_sz;
636 }
637
638 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
639 align += NET_IP_ALIGN;
640 if (unlikely(len < ETH_HLEN ||
641 (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
642 return -EINVAL;
643 }
644
645 skb = tun_alloc_skb(tun, align, len, gso.hdr_len, noblock);
646 if (IS_ERR(skb)) {
647 if (PTR_ERR(skb) != -EAGAIN)
648 tun->dev->stats.rx_dropped++;
649 return PTR_ERR(skb);
650 }
651
652 if (skb_copy_datagram_from_iovec(skb, 0, iv, offset, len)) {
653 tun->dev->stats.rx_dropped++;
654 kfree_skb(skb);
655 return -EFAULT;
656 }
657
658 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
659 if (!skb_partial_csum_set(skb, gso.csum_start,
660 gso.csum_offset)) {
661 tun->dev->stats.rx_frame_errors++;
662 kfree_skb(skb);
663 return -EINVAL;
664 }
665 }
666
667 switch (tun->flags & TUN_TYPE_MASK) {
668 case TUN_TUN_DEV:
669 if (tun->flags & TUN_NO_PI) {
670 switch (skb->data[0] & 0xf0) {
671 case 0x40:
672 pi.proto = htons(ETH_P_IP);
673 break;
674 case 0x60:
675 pi.proto = htons(ETH_P_IPV6);
676 break;
677 default:
678 tun->dev->stats.rx_dropped++;
679 kfree_skb(skb);
680 return -EINVAL;
681 }
682 }
683
684 skb_reset_mac_header(skb);
685 skb->protocol = pi.proto;
686 skb->dev = tun->dev;
687 break;
688 case TUN_TAP_DEV:
689 skb->protocol = eth_type_trans(skb, tun->dev);
690 break;
691 }
692
693 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
694 pr_debug("GSO!\n");
695 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
696 case VIRTIO_NET_HDR_GSO_TCPV4:
697 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
698 break;
699 case VIRTIO_NET_HDR_GSO_TCPV6:
700 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
701 break;
702 case VIRTIO_NET_HDR_GSO_UDP:
703 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
704 break;
705 default:
706 tun->dev->stats.rx_frame_errors++;
707 kfree_skb(skb);
708 return -EINVAL;
709 }
710
711 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
712 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
713
714 skb_shinfo(skb)->gso_size = gso.gso_size;
715 if (skb_shinfo(skb)->gso_size == 0) {
716 tun->dev->stats.rx_frame_errors++;
717 kfree_skb(skb);
718 return -EINVAL;
719 }
720
721 /* Header must be checked, and gso_segs computed. */
722 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
723 skb_shinfo(skb)->gso_segs = 0;
724 }
725
726 netif_rx_ni(skb);
727
728 tun->dev->stats.rx_packets++;
729 tun->dev->stats.rx_bytes += len;
730
731 return count;
732 }
733
734 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
735 unsigned long count, loff_t pos)
736 {
737 struct file *file = iocb->ki_filp;
738 struct tun_struct *tun = tun_get(file);
739 ssize_t result;
740
741 if (!tun)
742 return -EBADFD;
743
744 tun_debug(KERN_INFO, tun, "tun_chr_write %ld\n", count);
745
746 result = tun_get_user(tun, iv, iov_length(iv, count),
747 file->f_flags & O_NONBLOCK);
748
749 tun_put(tun);
750 return result;
751 }
752
753 /* Put packet to the user space buffer */
754 static ssize_t tun_put_user(struct tun_struct *tun,
755 struct sk_buff *skb,
756 const struct iovec *iv, int len)
757 {
758 struct tun_pi pi = { 0, skb->protocol };
759 ssize_t total = 0;
760
761 if (!(tun->flags & TUN_NO_PI)) {
762 if ((len -= sizeof(pi)) < 0)
763 return -EINVAL;
764
765 if (len < skb->len) {
766 /* Packet will be striped */
767 pi.flags |= TUN_PKT_STRIP;
768 }
769
770 if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi)))
771 return -EFAULT;
772 total += sizeof(pi);
773 }
774
775 if (tun->flags & TUN_VNET_HDR) {
776 struct virtio_net_hdr gso = { 0 }; /* no info leak */
777 if ((len -= tun->vnet_hdr_sz) < 0)
778 return -EINVAL;
779
780 if (skb_is_gso(skb)) {
781 struct skb_shared_info *sinfo = skb_shinfo(skb);
782
783 /* This is a hint as to how much should be linear. */
784 gso.hdr_len = skb_headlen(skb);
785 gso.gso_size = sinfo->gso_size;
786 if (sinfo->gso_type & SKB_GSO_TCPV4)
787 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
788 else if (sinfo->gso_type & SKB_GSO_TCPV6)
789 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
790 else if (sinfo->gso_type & SKB_GSO_UDP)
791 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
792 else {
793 pr_err("unexpected GSO type: "
794 "0x%x, gso_size %d, hdr_len %d\n",
795 sinfo->gso_type, gso.gso_size,
796 gso.hdr_len);
797 print_hex_dump(KERN_ERR, "tun: ",
798 DUMP_PREFIX_NONE,
799 16, 1, skb->head,
800 min((int)gso.hdr_len, 64), true);
801 WARN_ON_ONCE(1);
802 return -EINVAL;
803 }
804 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
805 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
806 } else
807 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
808
809 if (skb->ip_summed == CHECKSUM_PARTIAL) {
810 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
811 gso.csum_start = skb_checksum_start_offset(skb);
812 gso.csum_offset = skb->csum_offset;
813 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
814 gso.flags = VIRTIO_NET_HDR_F_DATA_VALID;
815 } /* else everything is zero */
816
817 if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
818 sizeof(gso))))
819 return -EFAULT;
820 total += tun->vnet_hdr_sz;
821 }
822
823 len = min_t(int, skb->len, len);
824
825 skb_copy_datagram_const_iovec(skb, 0, iv, total, len);
826 total += skb->len;
827
828 tun->dev->stats.tx_packets++;
829 tun->dev->stats.tx_bytes += len;
830
831 return total;
832 }
833
834 static ssize_t tun_do_read(struct tun_struct *tun,
835 struct kiocb *iocb, const struct iovec *iv,
836 ssize_t len, int noblock)
837 {
838 DECLARE_WAITQUEUE(wait, current);
839 struct sk_buff *skb;
840 ssize_t ret = 0;
841
842 tun_debug(KERN_INFO, tun, "tun_chr_read\n");
843
844 if (unlikely(!noblock))
845 add_wait_queue(&tun->wq.wait, &wait);
846 while (len) {
847 current->state = TASK_INTERRUPTIBLE;
848
849 /* Read frames from the queue */
850 if (!(skb=skb_dequeue(&tun->socket.sk->sk_receive_queue))) {
851 if (noblock) {
852 ret = -EAGAIN;
853 break;
854 }
855 if (signal_pending(current)) {
856 ret = -ERESTARTSYS;
857 break;
858 }
859 if (tun->dev->reg_state != NETREG_REGISTERED) {
860 ret = -EIO;
861 break;
862 }
863
864 /* Nothing to read, let's sleep */
865 schedule();
866 continue;
867 }
868 netif_wake_queue(tun->dev);
869
870 ret = tun_put_user(tun, skb, iv, len);
871 kfree_skb(skb);
872 break;
873 }
874
875 current->state = TASK_RUNNING;
876 if (unlikely(!noblock))
877 remove_wait_queue(&tun->wq.wait, &wait);
878
879 return ret;
880 }
881
882 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
883 unsigned long count, loff_t pos)
884 {
885 struct file *file = iocb->ki_filp;
886 struct tun_file *tfile = file->private_data;
887 struct tun_struct *tun = __tun_get(tfile);
888 ssize_t len, ret;
889
890 if (!tun)
891 return -EBADFD;
892 len = iov_length(iv, count);
893 if (len < 0) {
894 ret = -EINVAL;
895 goto out;
896 }
897
898 ret = tun_do_read(tun, iocb, iv, len, file->f_flags & O_NONBLOCK);
899 ret = min_t(ssize_t, ret, len);
900 out:
901 tun_put(tun);
902 return ret;
903 }
904
905 static void tun_setup(struct net_device *dev)
906 {
907 struct tun_struct *tun = netdev_priv(dev);
908
909 tun->owner = -1;
910 tun->group = -1;
911
912 dev->ethtool_ops = &tun_ethtool_ops;
913 dev->destructor = tun_free_netdev;
914 }
915
916 /* Trivial set of netlink ops to allow deleting tun or tap
917 * device with netlink.
918 */
919 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
920 {
921 return -EINVAL;
922 }
923
924 static struct rtnl_link_ops tun_link_ops __read_mostly = {
925 .kind = DRV_NAME,
926 .priv_size = sizeof(struct tun_struct),
927 .setup = tun_setup,
928 .validate = tun_validate,
929 };
930
931 static void tun_sock_write_space(struct sock *sk)
932 {
933 struct tun_struct *tun;
934 wait_queue_head_t *wqueue;
935
936 if (!sock_writeable(sk))
937 return;
938
939 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
940 return;
941
942 wqueue = sk_sleep(sk);
943 if (wqueue && waitqueue_active(wqueue))
944 wake_up_interruptible_sync_poll(wqueue, POLLOUT |
945 POLLWRNORM | POLLWRBAND);
946
947 tun = tun_sk(sk)->tun;
948 kill_fasync(&tun->fasync, SIGIO, POLL_OUT);
949 }
950
951 static void tun_sock_destruct(struct sock *sk)
952 {
953 free_netdev(tun_sk(sk)->tun->dev);
954 }
955
956 static int tun_sendmsg(struct kiocb *iocb, struct socket *sock,
957 struct msghdr *m, size_t total_len)
958 {
959 struct tun_struct *tun = container_of(sock, struct tun_struct, socket);
960 return tun_get_user(tun, m->msg_iov, total_len,
961 m->msg_flags & MSG_DONTWAIT);
962 }
963
964 static int tun_recvmsg(struct kiocb *iocb, struct socket *sock,
965 struct msghdr *m, size_t total_len,
966 int flags)
967 {
968 struct tun_struct *tun = container_of(sock, struct tun_struct, socket);
969 int ret;
970 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC))
971 return -EINVAL;
972 ret = tun_do_read(tun, iocb, m->msg_iov, total_len,
973 flags & MSG_DONTWAIT);
974 if (ret > total_len) {
975 m->msg_flags |= MSG_TRUNC;
976 ret = flags & MSG_TRUNC ? ret : total_len;
977 }
978 return ret;
979 }
980
981 /* Ops structure to mimic raw sockets with tun */
982 static const struct proto_ops tun_socket_ops = {
983 .sendmsg = tun_sendmsg,
984 .recvmsg = tun_recvmsg,
985 };
986
987 static struct proto tun_proto = {
988 .name = "tun",
989 .owner = THIS_MODULE,
990 .obj_size = sizeof(struct tun_sock),
991 };
992
993 static int tun_flags(struct tun_struct *tun)
994 {
995 int flags = 0;
996
997 if (tun->flags & TUN_TUN_DEV)
998 flags |= IFF_TUN;
999 else
1000 flags |= IFF_TAP;
1001
1002 if (tun->flags & TUN_NO_PI)
1003 flags |= IFF_NO_PI;
1004
1005 if (tun->flags & TUN_ONE_QUEUE)
1006 flags |= IFF_ONE_QUEUE;
1007
1008 if (tun->flags & TUN_VNET_HDR)
1009 flags |= IFF_VNET_HDR;
1010
1011 return flags;
1012 }
1013
1014 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
1015 char *buf)
1016 {
1017 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1018 return sprintf(buf, "0x%x\n", tun_flags(tun));
1019 }
1020
1021 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
1022 char *buf)
1023 {
1024 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1025 return sprintf(buf, "%d\n", tun->owner);
1026 }
1027
1028 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
1029 char *buf)
1030 {
1031 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1032 return sprintf(buf, "%d\n", tun->group);
1033 }
1034
1035 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
1036 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
1037 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
1038
1039 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
1040 {
1041 struct sock *sk;
1042 struct tun_struct *tun;
1043 struct net_device *dev;
1044 int err;
1045
1046 dev = __dev_get_by_name(net, ifr->ifr_name);
1047 if (dev) {
1048 const struct cred *cred = current_cred();
1049
1050 if (ifr->ifr_flags & IFF_TUN_EXCL)
1051 return -EBUSY;
1052 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
1053 tun = netdev_priv(dev);
1054 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
1055 tun = netdev_priv(dev);
1056 else
1057 return -EINVAL;
1058
1059 if (((tun->owner != -1 && cred->euid != tun->owner) ||
1060 (tun->group != -1 && !in_egroup_p(tun->group))) &&
1061 !capable(CAP_NET_ADMIN))
1062 return -EPERM;
1063 err = security_tun_dev_attach(tun->socket.sk);
1064 if (err < 0)
1065 return err;
1066
1067 err = tun_attach(tun, file);
1068 if (err < 0)
1069 return err;
1070 }
1071 else {
1072 char *name;
1073 unsigned long flags = 0;
1074
1075 if (!capable(CAP_NET_ADMIN))
1076 return -EPERM;
1077 err = security_tun_dev_create();
1078 if (err < 0)
1079 return err;
1080
1081 /* Set dev type */
1082 if (ifr->ifr_flags & IFF_TUN) {
1083 /* TUN device */
1084 flags |= TUN_TUN_DEV;
1085 name = "tun%d";
1086 } else if (ifr->ifr_flags & IFF_TAP) {
1087 /* TAP device */
1088 flags |= TUN_TAP_DEV;
1089 name = "tap%d";
1090 } else
1091 return -EINVAL;
1092
1093 if (*ifr->ifr_name)
1094 name = ifr->ifr_name;
1095
1096 dev = alloc_netdev(sizeof(struct tun_struct), name,
1097 tun_setup);
1098 if (!dev)
1099 return -ENOMEM;
1100
1101 dev_net_set(dev, net);
1102 dev->rtnl_link_ops = &tun_link_ops;
1103
1104 tun = netdev_priv(dev);
1105 tun->dev = dev;
1106 tun->flags = flags;
1107 tun->txflt.count = 0;
1108 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
1109
1110 err = -ENOMEM;
1111 sk = sk_alloc(net, AF_UNSPEC, GFP_KERNEL, &tun_proto);
1112 if (!sk)
1113 goto err_free_dev;
1114
1115 tun->socket.wq = &tun->wq;
1116 init_waitqueue_head(&tun->wq.wait);
1117 tun->socket.ops = &tun_socket_ops;
1118 sock_init_data(&tun->socket, sk);
1119 sk->sk_write_space = tun_sock_write_space;
1120 sk->sk_sndbuf = INT_MAX;
1121
1122 tun_sk(sk)->tun = tun;
1123
1124 security_tun_dev_post_create(sk);
1125
1126 tun_net_init(dev);
1127
1128 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
1129 TUN_USER_FEATURES;
1130 dev->features = dev->hw_features;
1131
1132 err = register_netdevice(tun->dev);
1133 if (err < 0)
1134 goto err_free_sk;
1135
1136 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
1137 device_create_file(&tun->dev->dev, &dev_attr_owner) ||
1138 device_create_file(&tun->dev->dev, &dev_attr_group))
1139 pr_err("Failed to create tun sysfs files\n");
1140
1141 sk->sk_destruct = tun_sock_destruct;
1142
1143 err = tun_attach(tun, file);
1144 if (err < 0)
1145 goto failed;
1146 }
1147
1148 tun_debug(KERN_INFO, tun, "tun_set_iff\n");
1149
1150 if (ifr->ifr_flags & IFF_NO_PI)
1151 tun->flags |= TUN_NO_PI;
1152 else
1153 tun->flags &= ~TUN_NO_PI;
1154
1155 if (ifr->ifr_flags & IFF_ONE_QUEUE)
1156 tun->flags |= TUN_ONE_QUEUE;
1157 else
1158 tun->flags &= ~TUN_ONE_QUEUE;
1159
1160 if (ifr->ifr_flags & IFF_VNET_HDR)
1161 tun->flags |= TUN_VNET_HDR;
1162 else
1163 tun->flags &= ~TUN_VNET_HDR;
1164
1165 /* Make sure persistent devices do not get stuck in
1166 * xoff state.
1167 */
1168 if (netif_running(tun->dev))
1169 netif_wake_queue(tun->dev);
1170
1171 strcpy(ifr->ifr_name, tun->dev->name);
1172 return 0;
1173
1174 err_free_sk:
1175 sock_put(sk);
1176 err_free_dev:
1177 free_netdev(dev);
1178 failed:
1179 return err;
1180 }
1181
1182 static int tun_get_iff(struct net *net, struct tun_struct *tun,
1183 struct ifreq *ifr)
1184 {
1185 tun_debug(KERN_INFO, tun, "tun_get_iff\n");
1186
1187 strcpy(ifr->ifr_name, tun->dev->name);
1188
1189 ifr->ifr_flags = tun_flags(tun);
1190
1191 return 0;
1192 }
1193
1194 /* This is like a cut-down ethtool ops, except done via tun fd so no
1195 * privs required. */
1196 static int set_offload(struct tun_struct *tun, unsigned long arg)
1197 {
1198 u32 features = 0;
1199
1200 if (arg & TUN_F_CSUM) {
1201 features |= NETIF_F_HW_CSUM;
1202 arg &= ~TUN_F_CSUM;
1203
1204 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1205 if (arg & TUN_F_TSO_ECN) {
1206 features |= NETIF_F_TSO_ECN;
1207 arg &= ~TUN_F_TSO_ECN;
1208 }
1209 if (arg & TUN_F_TSO4)
1210 features |= NETIF_F_TSO;
1211 if (arg & TUN_F_TSO6)
1212 features |= NETIF_F_TSO6;
1213 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1214 }
1215
1216 if (arg & TUN_F_UFO) {
1217 features |= NETIF_F_UFO;
1218 arg &= ~TUN_F_UFO;
1219 }
1220 }
1221
1222 /* This gives the user a way to test for new features in future by
1223 * trying to set them. */
1224 if (arg)
1225 return -EINVAL;
1226
1227 tun->set_features = features;
1228 netdev_update_features(tun->dev);
1229
1230 return 0;
1231 }
1232
1233 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
1234 unsigned long arg, int ifreq_len)
1235 {
1236 struct tun_file *tfile = file->private_data;
1237 struct tun_struct *tun;
1238 void __user* argp = (void __user*)arg;
1239 struct sock_fprog fprog;
1240 struct ifreq ifr;
1241 int sndbuf;
1242 int vnet_hdr_sz;
1243 int ret;
1244
1245 if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
1246 if (copy_from_user(&ifr, argp, ifreq_len))
1247 return -EFAULT;
1248
1249 if (cmd == TUNGETFEATURES) {
1250 /* Currently this just means: "what IFF flags are valid?".
1251 * This is needed because we never checked for invalid flags on
1252 * TUNSETIFF. */
1253 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
1254 IFF_VNET_HDR,
1255 (unsigned int __user*)argp);
1256 }
1257
1258 rtnl_lock();
1259
1260 tun = __tun_get(tfile);
1261 if (cmd == TUNSETIFF && !tun) {
1262 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1263
1264 ret = tun_set_iff(tfile->net, file, &ifr);
1265
1266 if (ret)
1267 goto unlock;
1268
1269 if (copy_to_user(argp, &ifr, ifreq_len))
1270 ret = -EFAULT;
1271 goto unlock;
1272 }
1273
1274 ret = -EBADFD;
1275 if (!tun)
1276 goto unlock;
1277
1278 tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %d\n", cmd);
1279
1280 ret = 0;
1281 switch (cmd) {
1282 case TUNGETIFF:
1283 ret = tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1284 if (ret)
1285 break;
1286
1287 if (copy_to_user(argp, &ifr, ifreq_len))
1288 ret = -EFAULT;
1289 break;
1290
1291 case TUNSETNOCSUM:
1292 /* Disable/Enable checksum */
1293
1294 /* [unimplemented] */
1295 tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n",
1296 arg ? "disabled" : "enabled");
1297 break;
1298
1299 case TUNSETPERSIST:
1300 /* Disable/Enable persist mode */
1301 if (arg)
1302 tun->flags |= TUN_PERSIST;
1303 else
1304 tun->flags &= ~TUN_PERSIST;
1305
1306 tun_debug(KERN_INFO, tun, "persist %s\n",
1307 arg ? "enabled" : "disabled");
1308 break;
1309
1310 case TUNSETOWNER:
1311 /* Set owner of the device */
1312 tun->owner = (uid_t) arg;
1313
1314 tun_debug(KERN_INFO, tun, "owner set to %d\n", tun->owner);
1315 break;
1316
1317 case TUNSETGROUP:
1318 /* Set group of the device */
1319 tun->group= (gid_t) arg;
1320
1321 tun_debug(KERN_INFO, tun, "group set to %d\n", tun->group);
1322 break;
1323
1324 case TUNSETLINK:
1325 /* Only allow setting the type when the interface is down */
1326 if (tun->dev->flags & IFF_UP) {
1327 tun_debug(KERN_INFO, tun,
1328 "Linktype set failed because interface is up\n");
1329 ret = -EBUSY;
1330 } else {
1331 tun->dev->type = (int) arg;
1332 tun_debug(KERN_INFO, tun, "linktype set to %d\n",
1333 tun->dev->type);
1334 ret = 0;
1335 }
1336 break;
1337
1338 #ifdef TUN_DEBUG
1339 case TUNSETDEBUG:
1340 tun->debug = arg;
1341 break;
1342 #endif
1343 case TUNSETOFFLOAD:
1344 ret = set_offload(tun, arg);
1345 break;
1346
1347 case TUNSETTXFILTER:
1348 /* Can be set only for TAPs */
1349 ret = -EINVAL;
1350 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1351 break;
1352 ret = update_filter(&tun->txflt, (void __user *)arg);
1353 break;
1354
1355 case SIOCGIFHWADDR:
1356 /* Get hw address */
1357 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
1358 ifr.ifr_hwaddr.sa_family = tun->dev->type;
1359 if (copy_to_user(argp, &ifr, ifreq_len))
1360 ret = -EFAULT;
1361 break;
1362
1363 case SIOCSIFHWADDR:
1364 /* Set hw address */
1365 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n",
1366 ifr.ifr_hwaddr.sa_data);
1367
1368 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
1369 break;
1370
1371 case TUNGETSNDBUF:
1372 sndbuf = tun->socket.sk->sk_sndbuf;
1373 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
1374 ret = -EFAULT;
1375 break;
1376
1377 case TUNSETSNDBUF:
1378 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
1379 ret = -EFAULT;
1380 break;
1381 }
1382
1383 tun->socket.sk->sk_sndbuf = sndbuf;
1384 break;
1385
1386 case TUNGETVNETHDRSZ:
1387 vnet_hdr_sz = tun->vnet_hdr_sz;
1388 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
1389 ret = -EFAULT;
1390 break;
1391
1392 case TUNSETVNETHDRSZ:
1393 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
1394 ret = -EFAULT;
1395 break;
1396 }
1397 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
1398 ret = -EINVAL;
1399 break;
1400 }
1401
1402 tun->vnet_hdr_sz = vnet_hdr_sz;
1403 break;
1404
1405 case TUNATTACHFILTER:
1406 /* Can be set only for TAPs */
1407 ret = -EINVAL;
1408 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1409 break;
1410 ret = -EFAULT;
1411 if (copy_from_user(&fprog, argp, sizeof(fprog)))
1412 break;
1413
1414 ret = sk_attach_filter(&fprog, tun->socket.sk);
1415 break;
1416
1417 case TUNDETACHFILTER:
1418 /* Can be set only for TAPs */
1419 ret = -EINVAL;
1420 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1421 break;
1422 ret = sk_detach_filter(tun->socket.sk);
1423 break;
1424
1425 default:
1426 ret = -EINVAL;
1427 break;
1428 }
1429
1430 unlock:
1431 rtnl_unlock();
1432 if (tun)
1433 tun_put(tun);
1434 return ret;
1435 }
1436
1437 static long tun_chr_ioctl(struct file *file,
1438 unsigned int cmd, unsigned long arg)
1439 {
1440 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
1441 }
1442
1443 #ifdef CONFIG_COMPAT
1444 static long tun_chr_compat_ioctl(struct file *file,
1445 unsigned int cmd, unsigned long arg)
1446 {
1447 switch (cmd) {
1448 case TUNSETIFF:
1449 case TUNGETIFF:
1450 case TUNSETTXFILTER:
1451 case TUNGETSNDBUF:
1452 case TUNSETSNDBUF:
1453 case SIOCGIFHWADDR:
1454 case SIOCSIFHWADDR:
1455 arg = (unsigned long)compat_ptr(arg);
1456 break;
1457 default:
1458 arg = (compat_ulong_t)arg;
1459 break;
1460 }
1461
1462 /*
1463 * compat_ifreq is shorter than ifreq, so we must not access beyond
1464 * the end of that structure. All fields that are used in this
1465 * driver are compatible though, we don't need to convert the
1466 * contents.
1467 */
1468 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
1469 }
1470 #endif /* CONFIG_COMPAT */
1471
1472 static int tun_chr_fasync(int fd, struct file *file, int on)
1473 {
1474 struct tun_struct *tun = tun_get(file);
1475 int ret;
1476
1477 if (!tun)
1478 return -EBADFD;
1479
1480 tun_debug(KERN_INFO, tun, "tun_chr_fasync %d\n", on);
1481
1482 if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
1483 goto out;
1484
1485 if (on) {
1486 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
1487 if (ret)
1488 goto out;
1489 tun->flags |= TUN_FASYNC;
1490 } else
1491 tun->flags &= ~TUN_FASYNC;
1492 ret = 0;
1493 out:
1494 tun_put(tun);
1495 return ret;
1496 }
1497
1498 static int tun_chr_open(struct inode *inode, struct file * file)
1499 {
1500 struct tun_file *tfile;
1501
1502 DBG1(KERN_INFO, "tunX: tun_chr_open\n");
1503
1504 tfile = kmalloc(sizeof(*tfile), GFP_KERNEL);
1505 if (!tfile)
1506 return -ENOMEM;
1507 atomic_set(&tfile->count, 0);
1508 tfile->tun = NULL;
1509 tfile->net = get_net(current->nsproxy->net_ns);
1510 file->private_data = tfile;
1511 return 0;
1512 }
1513
1514 static int tun_chr_close(struct inode *inode, struct file *file)
1515 {
1516 struct tun_file *tfile = file->private_data;
1517 struct tun_struct *tun;
1518
1519 tun = __tun_get(tfile);
1520 if (tun) {
1521 struct net_device *dev = tun->dev;
1522
1523 tun_debug(KERN_INFO, tun, "tun_chr_close\n");
1524
1525 __tun_detach(tun);
1526
1527 /* If desirable, unregister the netdevice. */
1528 if (!(tun->flags & TUN_PERSIST)) {
1529 rtnl_lock();
1530 if (dev->reg_state == NETREG_REGISTERED)
1531 unregister_netdevice(dev);
1532 rtnl_unlock();
1533 }
1534 }
1535
1536 tun = tfile->tun;
1537 if (tun)
1538 sock_put(tun->socket.sk);
1539
1540 put_net(tfile->net);
1541 kfree(tfile);
1542
1543 return 0;
1544 }
1545
1546 static const struct file_operations tun_fops = {
1547 .owner = THIS_MODULE,
1548 .llseek = no_llseek,
1549 .read = do_sync_read,
1550 .aio_read = tun_chr_aio_read,
1551 .write = do_sync_write,
1552 .aio_write = tun_chr_aio_write,
1553 .poll = tun_chr_poll,
1554 .unlocked_ioctl = tun_chr_ioctl,
1555 #ifdef CONFIG_COMPAT
1556 .compat_ioctl = tun_chr_compat_ioctl,
1557 #endif
1558 .open = tun_chr_open,
1559 .release = tun_chr_close,
1560 .fasync = tun_chr_fasync
1561 };
1562
1563 static struct miscdevice tun_miscdev = {
1564 .minor = TUN_MINOR,
1565 .name = "tun",
1566 .nodename = "net/tun",
1567 .fops = &tun_fops,
1568 };
1569
1570 /* ethtool interface */
1571
1572 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1573 {
1574 cmd->supported = 0;
1575 cmd->advertising = 0;
1576 ethtool_cmd_speed_set(cmd, SPEED_10);
1577 cmd->duplex = DUPLEX_FULL;
1578 cmd->port = PORT_TP;
1579 cmd->phy_address = 0;
1580 cmd->transceiver = XCVR_INTERNAL;
1581 cmd->autoneg = AUTONEG_DISABLE;
1582 cmd->maxtxpkt = 0;
1583 cmd->maxrxpkt = 0;
1584 return 0;
1585 }
1586
1587 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
1588 {
1589 struct tun_struct *tun = netdev_priv(dev);
1590
1591 strcpy(info->driver, DRV_NAME);
1592 strcpy(info->version, DRV_VERSION);
1593 strcpy(info->fw_version, "N/A");
1594
1595 switch (tun->flags & TUN_TYPE_MASK) {
1596 case TUN_TUN_DEV:
1597 strcpy(info->bus_info, "tun");
1598 break;
1599 case TUN_TAP_DEV:
1600 strcpy(info->bus_info, "tap");
1601 break;
1602 }
1603 }
1604
1605 static u32 tun_get_msglevel(struct net_device *dev)
1606 {
1607 #ifdef TUN_DEBUG
1608 struct tun_struct *tun = netdev_priv(dev);
1609 return tun->debug;
1610 #else
1611 return -EOPNOTSUPP;
1612 #endif
1613 }
1614
1615 static void tun_set_msglevel(struct net_device *dev, u32 value)
1616 {
1617 #ifdef TUN_DEBUG
1618 struct tun_struct *tun = netdev_priv(dev);
1619 tun->debug = value;
1620 #endif
1621 }
1622
1623 static const struct ethtool_ops tun_ethtool_ops = {
1624 .get_settings = tun_get_settings,
1625 .get_drvinfo = tun_get_drvinfo,
1626 .get_msglevel = tun_get_msglevel,
1627 .set_msglevel = tun_set_msglevel,
1628 .get_link = ethtool_op_get_link,
1629 };
1630
1631
1632 static int __init tun_init(void)
1633 {
1634 int ret = 0;
1635
1636 pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
1637 pr_info("%s\n", DRV_COPYRIGHT);
1638
1639 ret = rtnl_link_register(&tun_link_ops);
1640 if (ret) {
1641 pr_err("Can't register link_ops\n");
1642 goto err_linkops;
1643 }
1644
1645 ret = misc_register(&tun_miscdev);
1646 if (ret) {
1647 pr_err("Can't register misc device %d\n", TUN_MINOR);
1648 goto err_misc;
1649 }
1650 return 0;
1651 err_misc:
1652 rtnl_link_unregister(&tun_link_ops);
1653 err_linkops:
1654 return ret;
1655 }
1656
1657 static void tun_cleanup(void)
1658 {
1659 misc_deregister(&tun_miscdev);
1660 rtnl_link_unregister(&tun_link_ops);
1661 }
1662
1663 /* Get an underlying socket object from tun file. Returns error unless file is
1664 * attached to a device. The returned object works like a packet socket, it
1665 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
1666 * holding a reference to the file for as long as the socket is in use. */
1667 struct socket *tun_get_socket(struct file *file)
1668 {
1669 struct tun_struct *tun;
1670 if (file->f_op != &tun_fops)
1671 return ERR_PTR(-EINVAL);
1672 tun = tun_get(file);
1673 if (!tun)
1674 return ERR_PTR(-EBADFD);
1675 tun_put(tun);
1676 return &tun->socket;
1677 }
1678 EXPORT_SYMBOL_GPL(tun_get_socket);
1679
1680 module_init(tun_init);
1681 module_exit(tun_cleanup);
1682 MODULE_DESCRIPTION(DRV_DESCRIPTION);
1683 MODULE_AUTHOR(DRV_COPYRIGHT);
1684 MODULE_LICENSE("GPL");
1685 MODULE_ALIAS_MISCDEV(TUN_MINOR);
1686 MODULE_ALIAS("devname:net/tun");
Linux kernel - Deliverables
This page took 0.133049 seconds and 4 git commands to generate.