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driver core: add devname module aliases to allow module on-demand auto-loading
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / net / tun.c
blob005cad6895786099bde8c676c62e9d3e23fa20f0
1 /*
2 * TUN - Universal TUN/TAP device driver.
3 * Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * $Id: tun.c,v 1.15 2002/03/01 02:44:24 maxk Exp $
16 */
17
18 /*
19 * Changes:
20 *
21 * Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14
22 * Add TUNSETLINK ioctl to set the link encapsulation
23 *
24 * Mark Smith <markzzzsmith@yahoo.com.au>
25 * Use random_ether_addr() for tap MAC address.
26 *
27 * Harald Roelle <harald.roelle@ifi.lmu.de> 2004/04/20
28 * Fixes in packet dropping, queue length setting and queue wakeup.
29 * Increased default tx queue length.
30 * Added ethtool API.
31 * Minor cleanups
32 *
33 * Daniel Podlejski <underley@underley.eu.org>
34 * Modifications for 2.3.99-pre5 kernel.
35 */
36
37 #define DRV_NAME "tun"
38 #define DRV_VERSION "1.6"
39 #define DRV_DESCRIPTION "Universal TUN/TAP device driver"
40 #define DRV_COPYRIGHT "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>"
41
42 #include <linux/module.h>
43 #include <linux/errno.h>
44 #include <linux/kernel.h>
45 #include <linux/major.h>
46 #include <linux/slab.h>
47 #include <linux/poll.h>
48 #include <linux/fcntl.h>
49 #include <linux/init.h>
50 #include <linux/skbuff.h>
51 #include <linux/netdevice.h>
52 #include <linux/etherdevice.h>
53 #include <linux/miscdevice.h>
54 #include <linux/ethtool.h>
55 #include <linux/rtnetlink.h>
56 #include <linux/compat.h>
57 #include <linux/if.h>
58 #include <linux/if_arp.h>
59 #include <linux/if_ether.h>
60 #include <linux/if_tun.h>
61 #include <linux/crc32.h>
62 #include <linux/nsproxy.h>
63 #include <linux/virtio_net.h>
64 #include <linux/rcupdate.h>
65 #include <net/net_namespace.h>
66 #include <net/netns/generic.h>
67 #include <net/rtnetlink.h>
68 #include <net/sock.h>
69
70 #include <asm/system.h>
71 #include <asm/uaccess.h>
72
73 /* Uncomment to enable debugging */
74 /* #define TUN_DEBUG 1 */
75
76 #ifdef TUN_DEBUG
77 static int debug;
78
79 #define DBG if(tun->debug)printk
80 #define DBG1 if(debug==2)printk
81 #else
82 #define DBG( a... )
83 #define DBG1( a... )
84 #endif
85
86 #define FLT_EXACT_COUNT 8
87 struct tap_filter {
88 unsigned int count; /* Number of addrs. Zero means disabled */
89 u32 mask[2]; /* Mask of the hashed addrs */
90 unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN];
91 };
92
93 struct tun_file {
94 atomic_t count;
95 struct tun_struct *tun;
96 struct net *net;
97 };
98
99 struct tun_sock;
100
101 struct tun_struct {
102 struct tun_file *tfile;
103 unsigned int flags;
104 uid_t owner;
105 gid_t group;
106
107 struct net_device *dev;
108 struct fasync_struct *fasync;
109
110 struct tap_filter txflt;
111 struct socket socket;
112 struct socket_wq wq;
113
114 int vnet_hdr_sz;
115
116 #ifdef TUN_DEBUG
117 int debug;
118 #endif
119 };
120
121 struct tun_sock {
122 struct sock sk;
123 struct tun_struct *tun;
124 };
125
126 static inline struct tun_sock *tun_sk(struct sock *sk)
127 {
128 return container_of(sk, struct tun_sock, sk);
129 }
130
131 static int tun_attach(struct tun_struct *tun, struct file *file)
132 {
133 struct tun_file *tfile = file->private_data;
134 int err;
135
136 ASSERT_RTNL();
137
138 netif_tx_lock_bh(tun->dev);
139
140 err = -EINVAL;
141 if (tfile->tun)
142 goto out;
143
144 err = -EBUSY;
145 if (tun->tfile)
146 goto out;
147
148 err = 0;
149 tfile->tun = tun;
150 tun->tfile = tfile;
151 tun->socket.file = file;
152 dev_hold(tun->dev);
153 sock_hold(tun->socket.sk);
154 atomic_inc(&tfile->count);
155
156 out:
157 netif_tx_unlock_bh(tun->dev);
158 return err;
159 }
160
161 static void __tun_detach(struct tun_struct *tun)
162 {
163 /* Detach from net device */
164 netif_tx_lock_bh(tun->dev);
165 tun->tfile = NULL;
166 tun->socket.file = NULL;
167 netif_tx_unlock_bh(tun->dev);
168
169 /* Drop read queue */
170 skb_queue_purge(&tun->socket.sk->sk_receive_queue);
171
172 /* Drop the extra count on the net device */
173 dev_put(tun->dev);
174 }
175
176 static void tun_detach(struct tun_struct *tun)
177 {
178 rtnl_lock();
179 __tun_detach(tun);
180 rtnl_unlock();
181 }
182
183 static struct tun_struct *__tun_get(struct tun_file *tfile)
184 {
185 struct tun_struct *tun = NULL;
186
187 if (atomic_inc_not_zero(&tfile->count))
188 tun = tfile->tun;
189
190 return tun;
191 }
192
193 static struct tun_struct *tun_get(struct file *file)
194 {
195 return __tun_get(file->private_data);
196 }
197
198 static void tun_put(struct tun_struct *tun)
199 {
200 struct tun_file *tfile = tun->tfile;
201
202 if (atomic_dec_and_test(&tfile->count))
203 tun_detach(tfile->tun);
204 }
205
206 /* TAP filterting */
207 static void addr_hash_set(u32 *mask, const u8 *addr)
208 {
209 int n = ether_crc(ETH_ALEN, addr) >> 26;
210 mask[n >> 5] |= (1 << (n & 31));
211 }
212
213 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
214 {
215 int n = ether_crc(ETH_ALEN, addr) >> 26;
216 return mask[n >> 5] & (1 << (n & 31));
217 }
218
219 static int update_filter(struct tap_filter *filter, void __user *arg)
220 {
221 struct { u8 u[ETH_ALEN]; } *addr;
222 struct tun_filter uf;
223 int err, alen, n, nexact;
224
225 if (copy_from_user(&uf, arg, sizeof(uf)))
226 return -EFAULT;
227
228 if (!uf.count) {
229 /* Disabled */
230 filter->count = 0;
231 return 0;
232 }
233
234 alen = ETH_ALEN * uf.count;
235 addr = kmalloc(alen, GFP_KERNEL);
236 if (!addr)
237 return -ENOMEM;
238
239 if (copy_from_user(addr, arg + sizeof(uf), alen)) {
240 err = -EFAULT;
241 goto done;
242 }
243
244 /* The filter is updated without holding any locks. Which is
245 * perfectly safe. We disable it first and in the worst
246 * case we'll accept a few undesired packets. */
247 filter->count = 0;
248 wmb();
249
250 /* Use first set of addresses as an exact filter */
251 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
252 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
253
254 nexact = n;
255
256 /* Remaining multicast addresses are hashed,
257 * unicast will leave the filter disabled. */
258 memset(filter->mask, 0, sizeof(filter->mask));
259 for (; n < uf.count; n++) {
260 if (!is_multicast_ether_addr(addr[n].u)) {
261 err = 0; /* no filter */
262 goto done;
263 }
264 addr_hash_set(filter->mask, addr[n].u);
265 }
266
267 /* For ALLMULTI just set the mask to all ones.
268 * This overrides the mask populated above. */
269 if ((uf.flags & TUN_FLT_ALLMULTI))
270 memset(filter->mask, ~0, sizeof(filter->mask));
271
272 /* Now enable the filter */
273 wmb();
274 filter->count = nexact;
275
276 /* Return the number of exact filters */
277 err = nexact;
278
279 done:
280 kfree(addr);
281 return err;
282 }
283
284 /* Returns: 0 - drop, !=0 - accept */
285 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
286 {
287 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
288 * at this point. */
289 struct ethhdr *eh = (struct ethhdr *) skb->data;
290 int i;
291
292 /* Exact match */
293 for (i = 0; i < filter->count; i++)
294 if (!compare_ether_addr(eh->h_dest, filter->addr[i]))
295 return 1;
296
297 /* Inexact match (multicast only) */
298 if (is_multicast_ether_addr(eh->h_dest))
299 return addr_hash_test(filter->mask, eh->h_dest);
300
301 return 0;
302 }
303
304 /*
305 * Checks whether the packet is accepted or not.
306 * Returns: 0 - drop, !=0 - accept
307 */
308 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
309 {
310 if (!filter->count)
311 return 1;
312
313 return run_filter(filter, skb);
314 }
315
316 /* Network device part of the driver */
317
318 static const struct ethtool_ops tun_ethtool_ops;
319
320 /* Net device detach from fd. */
321 static void tun_net_uninit(struct net_device *dev)
322 {
323 struct tun_struct *tun = netdev_priv(dev);
324 struct tun_file *tfile = tun->tfile;
325
326 /* Inform the methods they need to stop using the dev.
327 */
328 if (tfile) {
329 wake_up_all(&tun->wq.wait);
330 if (atomic_dec_and_test(&tfile->count))
331 __tun_detach(tun);
332 }
333 }
334
335 static void tun_free_netdev(struct net_device *dev)
336 {
337 struct tun_struct *tun = netdev_priv(dev);
338
339 sock_put(tun->socket.sk);
340 }
341
342 /* Net device open. */
343 static int tun_net_open(struct net_device *dev)
344 {
345 netif_start_queue(dev);
346 return 0;
347 }
348
349 /* Net device close. */
350 static int tun_net_close(struct net_device *dev)
351 {
352 netif_stop_queue(dev);
353 return 0;
354 }
355
356 /* Net device start xmit */
357 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
358 {
359 struct tun_struct *tun = netdev_priv(dev);
360
361 DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len);
362
363 /* Drop packet if interface is not attached */
364 if (!tun->tfile)
365 goto drop;
366
367 /* Drop if the filter does not like it.
368 * This is a noop if the filter is disabled.
369 * Filter can be enabled only for the TAP devices. */
370 if (!check_filter(&tun->txflt, skb))
371 goto drop;
372
373 if (tun->socket.sk->sk_filter &&
374 sk_filter(tun->socket.sk, skb))
375 goto drop;
376
377 if (skb_queue_len(&tun->socket.sk->sk_receive_queue) >= dev->tx_queue_len) {
378 if (!(tun->flags & TUN_ONE_QUEUE)) {
379 /* Normal queueing mode. */
380 /* Packet scheduler handles dropping of further packets. */
381 netif_stop_queue(dev);
382
383 /* We won't see all dropped packets individually, so overrun
384 * error is more appropriate. */
385 dev->stats.tx_fifo_errors++;
386 } else {
387 /* Single queue mode.
388 * Driver handles dropping of all packets itself. */
389 goto drop;
390 }
391 }
392
393 /* Orphan the skb - required as we might hang on to it
394 * for indefinite time. */
395 skb_orphan(skb);
396
397 /* Enqueue packet */
398 skb_queue_tail(&tun->socket.sk->sk_receive_queue, skb);
399
400 /* Notify and wake up reader process */
401 if (tun->flags & TUN_FASYNC)
402 kill_fasync(&tun->fasync, SIGIO, POLL_IN);
403 wake_up_interruptible_poll(&tun->wq.wait, POLLIN |
404 POLLRDNORM | POLLRDBAND);
405 return NETDEV_TX_OK;
406
407 drop:
408 dev->stats.tx_dropped++;
409 kfree_skb(skb);
410 return NETDEV_TX_OK;
411 }
412
413 static void tun_net_mclist(struct net_device *dev)
414 {
415 /*
416 * This callback is supposed to deal with mc filter in
417 * _rx_ path and has nothing to do with the _tx_ path.
418 * In rx path we always accept everything userspace gives us.
419 */
420 }
421
422 #define MIN_MTU 68
423 #define MAX_MTU 65535
424
425 static int
426 tun_net_change_mtu(struct net_device *dev, int new_mtu)
427 {
428 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
429 return -EINVAL;
430 dev->mtu = new_mtu;
431 return 0;
432 }
433
434 static const struct net_device_ops tun_netdev_ops = {
435 .ndo_uninit = tun_net_uninit,
436 .ndo_open = tun_net_open,
437 .ndo_stop = tun_net_close,
438 .ndo_start_xmit = tun_net_xmit,
439 .ndo_change_mtu = tun_net_change_mtu,
440 };
441
442 static const struct net_device_ops tap_netdev_ops = {
443 .ndo_uninit = tun_net_uninit,
444 .ndo_open = tun_net_open,
445 .ndo_stop = tun_net_close,
446 .ndo_start_xmit = tun_net_xmit,
447 .ndo_change_mtu = tun_net_change_mtu,
448 .ndo_set_multicast_list = tun_net_mclist,
449 .ndo_set_mac_address = eth_mac_addr,
450 .ndo_validate_addr = eth_validate_addr,
451 };
452
453 /* Initialize net device. */
454 static void tun_net_init(struct net_device *dev)
455 {
456 struct tun_struct *tun = netdev_priv(dev);
457
458 switch (tun->flags & TUN_TYPE_MASK) {
459 case TUN_TUN_DEV:
460 dev->netdev_ops = &tun_netdev_ops;
461
462 /* Point-to-Point TUN Device */
463 dev->hard_header_len = 0;
464 dev->addr_len = 0;
465 dev->mtu = 1500;
466
467 /* Zero header length */
468 dev->type = ARPHRD_NONE;
469 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
470 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
471 break;
472
473 case TUN_TAP_DEV:
474 dev->netdev_ops = &tap_netdev_ops;
475 /* Ethernet TAP Device */
476 ether_setup(dev);
477
478 random_ether_addr(dev->dev_addr);
479
480 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
481 break;
482 }
483 }
484
485 /* Character device part */
486
487 /* Poll */
488 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
489 {
490 struct tun_file *tfile = file->private_data;
491 struct tun_struct *tun = __tun_get(tfile);
492 struct sock *sk;
493 unsigned int mask = 0;
494
495 if (!tun)
496 return POLLERR;
497
498 sk = tun->socket.sk;
499
500 DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name);
501
502 poll_wait(file, &tun->wq.wait, wait);
503
504 if (!skb_queue_empty(&sk->sk_receive_queue))
505 mask |= POLLIN | POLLRDNORM;
506
507 if (sock_writeable(sk) ||
508 (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
509 sock_writeable(sk)))
510 mask |= POLLOUT | POLLWRNORM;
511
512 if (tun->dev->reg_state != NETREG_REGISTERED)
513 mask = POLLERR;
514
515 tun_put(tun);
516 return mask;
517 }
518
519 /* prepad is the amount to reserve at front. len is length after that.
520 * linear is a hint as to how much to copy (usually headers). */
521 static inline struct sk_buff *tun_alloc_skb(struct tun_struct *tun,
522 size_t prepad, size_t len,
523 size_t linear, int noblock)
524 {
525 struct sock *sk = tun->socket.sk;
526 struct sk_buff *skb;
527 int err;
528
529 /* Under a page? Don't bother with paged skb. */
530 if (prepad + len < PAGE_SIZE || !linear)
531 linear = len;
532
533 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
534 &err);
535 if (!skb)
536 return ERR_PTR(err);
537
538 skb_reserve(skb, prepad);
539 skb_put(skb, linear);
540 skb->data_len = len - linear;
541 skb->len += len - linear;
542
543 return skb;
544 }
545
546 /* Get packet from user space buffer */
547 static __inline__ ssize_t tun_get_user(struct tun_struct *tun,
548 const struct iovec *iv, size_t count,
549 int noblock)
550 {
551 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
552 struct sk_buff *skb;
553 size_t len = count, align = 0;
554 struct virtio_net_hdr gso = { 0 };
555 int offset = 0;
556
557 if (!(tun->flags & TUN_NO_PI)) {
558 if ((len -= sizeof(pi)) > count)
559 return -EINVAL;
560
561 if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
562 return -EFAULT;
563 offset += sizeof(pi);
564 }
565
566 if (tun->flags & TUN_VNET_HDR) {
567 if ((len -= tun->vnet_hdr_sz) > count)
568 return -EINVAL;
569
570 if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
571 return -EFAULT;
572
573 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
574 gso.csum_start + gso.csum_offset + 2 > gso.hdr_len)
575 gso.hdr_len = gso.csum_start + gso.csum_offset + 2;
576
577 if (gso.hdr_len > len)
578 return -EINVAL;
579 offset += tun->vnet_hdr_sz;
580 }
581
582 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
583 align = NET_IP_ALIGN;
584 if (unlikely(len < ETH_HLEN ||
585 (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
586 return -EINVAL;
587 }
588
589 skb = tun_alloc_skb(tun, align, len, gso.hdr_len, noblock);
590 if (IS_ERR(skb)) {
591 if (PTR_ERR(skb) != -EAGAIN)
592 tun->dev->stats.rx_dropped++;
593 return PTR_ERR(skb);
594 }
595
596 if (skb_copy_datagram_from_iovec(skb, 0, iv, offset, len)) {
597 tun->dev->stats.rx_dropped++;
598 kfree_skb(skb);
599 return -EFAULT;
600 }
601
602 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
603 if (!skb_partial_csum_set(skb, gso.csum_start,
604 gso.csum_offset)) {
605 tun->dev->stats.rx_frame_errors++;
606 kfree_skb(skb);
607 return -EINVAL;
608 }
609 } else if (tun->flags & TUN_NOCHECKSUM)
610 skb->ip_summed = CHECKSUM_UNNECESSARY;
611
612 switch (tun->flags & TUN_TYPE_MASK) {
613 case TUN_TUN_DEV:
614 if (tun->flags & TUN_NO_PI) {
615 switch (skb->data[0] & 0xf0) {
616 case 0x40:
617 pi.proto = htons(ETH_P_IP);
618 break;
619 case 0x60:
620 pi.proto = htons(ETH_P_IPV6);
621 break;
622 default:
623 tun->dev->stats.rx_dropped++;
624 kfree_skb(skb);
625 return -EINVAL;
626 }
627 }
628
629 skb_reset_mac_header(skb);
630 skb->protocol = pi.proto;
631 skb->dev = tun->dev;
632 break;
633 case TUN_TAP_DEV:
634 skb->protocol = eth_type_trans(skb, tun->dev);
635 break;
636 };
637
638 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
639 pr_debug("GSO!\n");
640 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
641 case VIRTIO_NET_HDR_GSO_TCPV4:
642 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
643 break;
644 case VIRTIO_NET_HDR_GSO_TCPV6:
645 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
646 break;
647 case VIRTIO_NET_HDR_GSO_UDP:
648 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
649 break;
650 default:
651 tun->dev->stats.rx_frame_errors++;
652 kfree_skb(skb);
653 return -EINVAL;
654 }
655
656 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
657 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
658
659 skb_shinfo(skb)->gso_size = gso.gso_size;
660 if (skb_shinfo(skb)->gso_size == 0) {
661 tun->dev->stats.rx_frame_errors++;
662 kfree_skb(skb);
663 return -EINVAL;
664 }
665
666 /* Header must be checked, and gso_segs computed. */
667 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
668 skb_shinfo(skb)->gso_segs = 0;
669 }
670
671 netif_rx_ni(skb);
672
673 tun->dev->stats.rx_packets++;
674 tun->dev->stats.rx_bytes += len;
675
676 return count;
677 }
678
679 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
680 unsigned long count, loff_t pos)
681 {
682 struct file *file = iocb->ki_filp;
683 struct tun_struct *tun = tun_get(file);
684 ssize_t result;
685
686 if (!tun)
687 return -EBADFD;
688
689 DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);
690
691 result = tun_get_user(tun, iv, iov_length(iv, count),
692 file->f_flags & O_NONBLOCK);
693
694 tun_put(tun);
695 return result;
696 }
697
698 /* Put packet to the user space buffer */
699 static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
700 struct sk_buff *skb,
701 const struct iovec *iv, int len)
702 {
703 struct tun_pi pi = { 0, skb->protocol };
704 ssize_t total = 0;
705
706 if (!(tun->flags & TUN_NO_PI)) {
707 if ((len -= sizeof(pi)) < 0)
708 return -EINVAL;
709
710 if (len < skb->len) {
711 /* Packet will be striped */
712 pi.flags |= TUN_PKT_STRIP;
713 }
714
715 if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi)))
716 return -EFAULT;
717 total += sizeof(pi);
718 }
719
720 if (tun->flags & TUN_VNET_HDR) {
721 struct virtio_net_hdr gso = { 0 }; /* no info leak */
722 if ((len -= tun->vnet_hdr_sz) < 0)
723 return -EINVAL;
724
725 if (skb_is_gso(skb)) {
726 struct skb_shared_info *sinfo = skb_shinfo(skb);
727
728 /* This is a hint as to how much should be linear. */
729 gso.hdr_len = skb_headlen(skb);
730 gso.gso_size = sinfo->gso_size;
731 if (sinfo->gso_type & SKB_GSO_TCPV4)
732 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
733 else if (sinfo->gso_type & SKB_GSO_TCPV6)
734 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
735 else if (sinfo->gso_type & SKB_GSO_UDP)
736 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
737 else
738 BUG();
739 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
740 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
741 } else
742 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
743
744 if (skb->ip_summed == CHECKSUM_PARTIAL) {
745 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
746 gso.csum_start = skb->csum_start - skb_headroom(skb);
747 gso.csum_offset = skb->csum_offset;
748 } /* else everything is zero */
749
750 if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
751 sizeof(gso))))
752 return -EFAULT;
753 total += tun->vnet_hdr_sz;
754 }
755
756 len = min_t(int, skb->len, len);
757
758 skb_copy_datagram_const_iovec(skb, 0, iv, total, len);
759 total += skb->len;
760
761 tun->dev->stats.tx_packets++;
762 tun->dev->stats.tx_bytes += len;
763
764 return total;
765 }
766
767 static ssize_t tun_do_read(struct tun_struct *tun,
768 struct kiocb *iocb, const struct iovec *iv,
769 ssize_t len, int noblock)
770 {
771 DECLARE_WAITQUEUE(wait, current);
772 struct sk_buff *skb;
773 ssize_t ret = 0;
774
775 DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
776
777 add_wait_queue(&tun->wq.wait, &wait);
778 while (len) {
779 current->state = TASK_INTERRUPTIBLE;
780
781 /* Read frames from the queue */
782 if (!(skb=skb_dequeue(&tun->socket.sk->sk_receive_queue))) {
783 if (noblock) {
784 ret = -EAGAIN;
785 break;
786 }
787 if (signal_pending(current)) {
788 ret = -ERESTARTSYS;
789 break;
790 }
791 if (tun->dev->reg_state != NETREG_REGISTERED) {
792 ret = -EIO;
793 break;
794 }
795
796 /* Nothing to read, let's sleep */
797 schedule();
798 continue;
799 }
800 netif_wake_queue(tun->dev);
801
802 ret = tun_put_user(tun, skb, iv, len);
803 kfree_skb(skb);
804 break;
805 }
806
807 current->state = TASK_RUNNING;
808 remove_wait_queue(&tun->wq.wait, &wait);
809
810 return ret;
811 }
812
813 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
814 unsigned long count, loff_t pos)
815 {
816 struct file *file = iocb->ki_filp;
817 struct tun_file *tfile = file->private_data;
818 struct tun_struct *tun = __tun_get(tfile);
819 ssize_t len, ret;
820
821 if (!tun)
822 return -EBADFD;
823 len = iov_length(iv, count);
824 if (len < 0) {
825 ret = -EINVAL;
826 goto out;
827 }
828
829 ret = tun_do_read(tun, iocb, iv, len, file->f_flags & O_NONBLOCK);
830 ret = min_t(ssize_t, ret, len);
831 out:
832 tun_put(tun);
833 return ret;
834 }
835
836 static void tun_setup(struct net_device *dev)
837 {
838 struct tun_struct *tun = netdev_priv(dev);
839
840 tun->owner = -1;
841 tun->group = -1;
842
843 dev->ethtool_ops = &tun_ethtool_ops;
844 dev->destructor = tun_free_netdev;
845 }
846
847 /* Trivial set of netlink ops to allow deleting tun or tap
848 * device with netlink.
849 */
850 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
851 {
852 return -EINVAL;
853 }
854
855 static struct rtnl_link_ops tun_link_ops __read_mostly = {
856 .kind = DRV_NAME,
857 .priv_size = sizeof(struct tun_struct),
858 .setup = tun_setup,
859 .validate = tun_validate,
860 };
861
862 static void tun_sock_write_space(struct sock *sk)
863 {
864 struct tun_struct *tun;
865 wait_queue_head_t *wqueue;
866
867 if (!sock_writeable(sk))
868 return;
869
870 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
871 return;
872
873 wqueue = sk_sleep(sk);
874 if (wqueue && waitqueue_active(wqueue))
875 wake_up_interruptible_sync_poll(wqueue, POLLOUT |
876 POLLWRNORM | POLLWRBAND);
877
878 tun = tun_sk(sk)->tun;
879 kill_fasync(&tun->fasync, SIGIO, POLL_OUT);
880 }
881
882 static void tun_sock_destruct(struct sock *sk)
883 {
884 free_netdev(tun_sk(sk)->tun->dev);
885 }
886
887 static int tun_sendmsg(struct kiocb *iocb, struct socket *sock,
888 struct msghdr *m, size_t total_len)
889 {
890 struct tun_struct *tun = container_of(sock, struct tun_struct, socket);
891 return tun_get_user(tun, m->msg_iov, total_len,
892 m->msg_flags & MSG_DONTWAIT);
893 }
894
895 static int tun_recvmsg(struct kiocb *iocb, struct socket *sock,
896 struct msghdr *m, size_t total_len,
897 int flags)
898 {
899 struct tun_struct *tun = container_of(sock, struct tun_struct, socket);
900 int ret;
901 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC))
902 return -EINVAL;
903 ret = tun_do_read(tun, iocb, m->msg_iov, total_len,
904 flags & MSG_DONTWAIT);
905 if (ret > total_len) {
906 m->msg_flags |= MSG_TRUNC;
907 ret = flags & MSG_TRUNC ? ret : total_len;
908 }
909 return ret;
910 }
911
912 /* Ops structure to mimic raw sockets with tun */
913 static const struct proto_ops tun_socket_ops = {
914 .sendmsg = tun_sendmsg,
915 .recvmsg = tun_recvmsg,
916 };
917
918 static struct proto tun_proto = {
919 .name = "tun",
920 .owner = THIS_MODULE,
921 .obj_size = sizeof(struct tun_sock),
922 };
923
924 static int tun_flags(struct tun_struct *tun)
925 {
926 int flags = 0;
927
928 if (tun->flags & TUN_TUN_DEV)
929 flags |= IFF_TUN;
930 else
931 flags |= IFF_TAP;
932
933 if (tun->flags & TUN_NO_PI)
934 flags |= IFF_NO_PI;
935
936 if (tun->flags & TUN_ONE_QUEUE)
937 flags |= IFF_ONE_QUEUE;
938
939 if (tun->flags & TUN_VNET_HDR)
940 flags |= IFF_VNET_HDR;
941
942 return flags;
943 }
944
945 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
946 char *buf)
947 {
948 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
949 return sprintf(buf, "0x%x\n", tun_flags(tun));
950 }
951
952 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
953 char *buf)
954 {
955 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
956 return sprintf(buf, "%d\n", tun->owner);
957 }
958
959 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
960 char *buf)
961 {
962 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
963 return sprintf(buf, "%d\n", tun->group);
964 }
965
966 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
967 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
968 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
969
970 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
971 {
972 struct sock *sk;
973 struct tun_struct *tun;
974 struct net_device *dev;
975 int err;
976
977 dev = __dev_get_by_name(net, ifr->ifr_name);
978 if (dev) {
979 const struct cred *cred = current_cred();
980
981 if (ifr->ifr_flags & IFF_TUN_EXCL)
982 return -EBUSY;
983 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
984 tun = netdev_priv(dev);
985 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
986 tun = netdev_priv(dev);
987 else
988 return -EINVAL;
989
990 if (((tun->owner != -1 && cred->euid != tun->owner) ||
991 (tun->group != -1 && !in_egroup_p(tun->group))) &&
992 !capable(CAP_NET_ADMIN))
993 return -EPERM;
994 err = security_tun_dev_attach(tun->socket.sk);
995 if (err < 0)
996 return err;
997
998 err = tun_attach(tun, file);
999 if (err < 0)
1000 return err;
1001 }
1002 else {
1003 char *name;
1004 unsigned long flags = 0;
1005
1006 if (!capable(CAP_NET_ADMIN))
1007 return -EPERM;
1008 err = security_tun_dev_create();
1009 if (err < 0)
1010 return err;
1011
1012 /* Set dev type */
1013 if (ifr->ifr_flags & IFF_TUN) {
1014 /* TUN device */
1015 flags |= TUN_TUN_DEV;
1016 name = "tun%d";
1017 } else if (ifr->ifr_flags & IFF_TAP) {
1018 /* TAP device */
1019 flags |= TUN_TAP_DEV;
1020 name = "tap%d";
1021 } else
1022 return -EINVAL;
1023
1024 if (*ifr->ifr_name)
1025 name = ifr->ifr_name;
1026
1027 dev = alloc_netdev(sizeof(struct tun_struct), name,
1028 tun_setup);
1029 if (!dev)
1030 return -ENOMEM;
1031
1032 dev_net_set(dev, net);
1033 dev->rtnl_link_ops = &tun_link_ops;
1034
1035 tun = netdev_priv(dev);
1036 tun->dev = dev;
1037 tun->flags = flags;
1038 tun->txflt.count = 0;
1039 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
1040
1041 err = -ENOMEM;
1042 sk = sk_alloc(net, AF_UNSPEC, GFP_KERNEL, &tun_proto);
1043 if (!sk)
1044 goto err_free_dev;
1045
1046 tun->socket.wq = &tun->wq;
1047 init_waitqueue_head(&tun->wq.wait);
1048 tun->socket.ops = &tun_socket_ops;
1049 sock_init_data(&tun->socket, sk);
1050 sk->sk_write_space = tun_sock_write_space;
1051 sk->sk_sndbuf = INT_MAX;
1052
1053 tun_sk(sk)->tun = tun;
1054
1055 security_tun_dev_post_create(sk);
1056
1057 tun_net_init(dev);
1058
1059 if (strchr(dev->name, '%')) {
1060 err = dev_alloc_name(dev, dev->name);
1061 if (err < 0)
1062 goto err_free_sk;
1063 }
1064
1065 err = register_netdevice(tun->dev);
1066 if (err < 0)
1067 goto err_free_sk;
1068
1069 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
1070 device_create_file(&tun->dev->dev, &dev_attr_owner) ||
1071 device_create_file(&tun->dev->dev, &dev_attr_group))
1072 printk(KERN_ERR "Failed to create tun sysfs files\n");
1073
1074 sk->sk_destruct = tun_sock_destruct;
1075
1076 err = tun_attach(tun, file);
1077 if (err < 0)
1078 goto failed;
1079 }
1080
1081 DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);
1082
1083 if (ifr->ifr_flags & IFF_NO_PI)
1084 tun->flags |= TUN_NO_PI;
1085 else
1086 tun->flags &= ~TUN_NO_PI;
1087
1088 if (ifr->ifr_flags & IFF_ONE_QUEUE)
1089 tun->flags |= TUN_ONE_QUEUE;
1090 else
1091 tun->flags &= ~TUN_ONE_QUEUE;
1092
1093 if (ifr->ifr_flags & IFF_VNET_HDR)
1094 tun->flags |= TUN_VNET_HDR;
1095 else
1096 tun->flags &= ~TUN_VNET_HDR;
1097
1098 /* Make sure persistent devices do not get stuck in
1099 * xoff state.
1100 */
1101 if (netif_running(tun->dev))
1102 netif_wake_queue(tun->dev);
1103
1104 strcpy(ifr->ifr_name, tun->dev->name);
1105 return 0;
1106
1107 err_free_sk:
1108 sock_put(sk);
1109 err_free_dev:
1110 free_netdev(dev);
1111 failed:
1112 return err;
1113 }
1114
1115 static int tun_get_iff(struct net *net, struct tun_struct *tun,
1116 struct ifreq *ifr)
1117 {
1118 DBG(KERN_INFO "%s: tun_get_iff\n", tun->dev->name);
1119
1120 strcpy(ifr->ifr_name, tun->dev->name);
1121
1122 ifr->ifr_flags = tun_flags(tun);
1123
1124 return 0;
1125 }
1126
1127 /* This is like a cut-down ethtool ops, except done via tun fd so no
1128 * privs required. */
1129 static int set_offload(struct net_device *dev, unsigned long arg)
1130 {
1131 unsigned int old_features, features;
1132
1133 old_features = dev->features;
1134 /* Unset features, set them as we chew on the arg. */
1135 features = (old_features & ~(NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST
1136 |NETIF_F_TSO_ECN|NETIF_F_TSO|NETIF_F_TSO6
1137 |NETIF_F_UFO));
1138
1139 if (arg & TUN_F_CSUM) {
1140 features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1141 arg &= ~TUN_F_CSUM;
1142
1143 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1144 if (arg & TUN_F_TSO_ECN) {
1145 features |= NETIF_F_TSO_ECN;
1146 arg &= ~TUN_F_TSO_ECN;
1147 }
1148 if (arg & TUN_F_TSO4)
1149 features |= NETIF_F_TSO;
1150 if (arg & TUN_F_TSO6)
1151 features |= NETIF_F_TSO6;
1152 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1153 }
1154
1155 if (arg & TUN_F_UFO) {
1156 features |= NETIF_F_UFO;
1157 arg &= ~TUN_F_UFO;
1158 }
1159 }
1160
1161 /* This gives the user a way to test for new features in future by
1162 * trying to set them. */
1163 if (arg)
1164 return -EINVAL;
1165
1166 dev->features = features;
1167 if (old_features != dev->features)
1168 netdev_features_change(dev);
1169
1170 return 0;
1171 }
1172
1173 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
1174 unsigned long arg, int ifreq_len)
1175 {
1176 struct tun_file *tfile = file->private_data;
1177 struct tun_struct *tun;
1178 void __user* argp = (void __user*)arg;
1179 struct sock_fprog fprog;
1180 struct ifreq ifr;
1181 int sndbuf;
1182 int vnet_hdr_sz;
1183 int ret;
1184
1185 if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
1186 if (copy_from_user(&ifr, argp, ifreq_len))
1187 return -EFAULT;
1188
1189 if (cmd == TUNGETFEATURES) {
1190 /* Currently this just means: "what IFF flags are valid?".
1191 * This is needed because we never checked for invalid flags on
1192 * TUNSETIFF. */
1193 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
1194 IFF_VNET_HDR,
1195 (unsigned int __user*)argp);
1196 }
1197
1198 rtnl_lock();
1199
1200 tun = __tun_get(tfile);
1201 if (cmd == TUNSETIFF && !tun) {
1202 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1203
1204 ret = tun_set_iff(tfile->net, file, &ifr);
1205
1206 if (ret)
1207 goto unlock;
1208
1209 if (copy_to_user(argp, &ifr, ifreq_len))
1210 ret = -EFAULT;
1211 goto unlock;
1212 }
1213
1214 ret = -EBADFD;
1215 if (!tun)
1216 goto unlock;
1217
1218 DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd);
1219
1220 ret = 0;
1221 switch (cmd) {
1222 case TUNGETIFF:
1223 ret = tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1224 if (ret)
1225 break;
1226
1227 if (copy_to_user(argp, &ifr, ifreq_len))
1228 ret = -EFAULT;
1229 break;
1230
1231 case TUNSETNOCSUM:
1232 /* Disable/Enable checksum */
1233 if (arg)
1234 tun->flags |= TUN_NOCHECKSUM;
1235 else
1236 tun->flags &= ~TUN_NOCHECKSUM;
1237
1238 DBG(KERN_INFO "%s: checksum %s\n",
1239 tun->dev->name, arg ? "disabled" : "enabled");
1240 break;
1241
1242 case TUNSETPERSIST:
1243 /* Disable/Enable persist mode */
1244 if (arg)
1245 tun->flags |= TUN_PERSIST;
1246 else
1247 tun->flags &= ~TUN_PERSIST;
1248
1249 DBG(KERN_INFO "%s: persist %s\n",
1250 tun->dev->name, arg ? "enabled" : "disabled");
1251 break;
1252
1253 case TUNSETOWNER:
1254 /* Set owner of the device */
1255 tun->owner = (uid_t) arg;
1256
1257 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner);
1258 break;
1259
1260 case TUNSETGROUP:
1261 /* Set group of the device */
1262 tun->group= (gid_t) arg;
1263
1264 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group);
1265 break;
1266
1267 case TUNSETLINK:
1268 /* Only allow setting the type when the interface is down */
1269 if (tun->dev->flags & IFF_UP) {
1270 DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
1271 tun->dev->name);
1272 ret = -EBUSY;
1273 } else {
1274 tun->dev->type = (int) arg;
1275 DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
1276 ret = 0;
1277 }
1278 break;
1279
1280 #ifdef TUN_DEBUG
1281 case TUNSETDEBUG:
1282 tun->debug = arg;
1283 break;
1284 #endif
1285 case TUNSETOFFLOAD:
1286 ret = set_offload(tun->dev, arg);
1287 break;
1288
1289 case TUNSETTXFILTER:
1290 /* Can be set only for TAPs */
1291 ret = -EINVAL;
1292 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1293 break;
1294 ret = update_filter(&tun->txflt, (void __user *)arg);
1295 break;
1296
1297 case SIOCGIFHWADDR:
1298 /* Get hw addres */
1299 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
1300 ifr.ifr_hwaddr.sa_family = tun->dev->type;
1301 if (copy_to_user(argp, &ifr, ifreq_len))
1302 ret = -EFAULT;
1303 break;
1304
1305 case SIOCSIFHWADDR:
1306 /* Set hw address */
1307 DBG(KERN_DEBUG "%s: set hw address: %pM\n",
1308 tun->dev->name, ifr.ifr_hwaddr.sa_data);
1309
1310 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
1311 break;
1312
1313 case TUNGETSNDBUF:
1314 sndbuf = tun->socket.sk->sk_sndbuf;
1315 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
1316 ret = -EFAULT;
1317 break;
1318
1319 case TUNSETSNDBUF:
1320 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
1321 ret = -EFAULT;
1322 break;
1323 }
1324
1325 tun->socket.sk->sk_sndbuf = sndbuf;
1326 break;
1327
1328 case TUNGETVNETHDRSZ:
1329 vnet_hdr_sz = tun->vnet_hdr_sz;
1330 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
1331 ret = -EFAULT;
1332 break;
1333
1334 case TUNSETVNETHDRSZ:
1335 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
1336 ret = -EFAULT;
1337 break;
1338 }
1339 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
1340 ret = -EINVAL;
1341 break;
1342 }
1343
1344 tun->vnet_hdr_sz = vnet_hdr_sz;
1345 break;
1346
1347 case TUNATTACHFILTER:
1348 /* Can be set only for TAPs */
1349 ret = -EINVAL;
1350 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1351 break;
1352 ret = -EFAULT;
1353 if (copy_from_user(&fprog, argp, sizeof(fprog)))
1354 break;
1355
1356 ret = sk_attach_filter(&fprog, tun->socket.sk);
1357 break;
1358
1359 case TUNDETACHFILTER:
1360 /* Can be set only for TAPs */
1361 ret = -EINVAL;
1362 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1363 break;
1364 ret = sk_detach_filter(tun->socket.sk);
1365 break;
1366
1367 default:
1368 ret = -EINVAL;
1369 break;
1370 }
1371
1372 unlock:
1373 rtnl_unlock();
1374 if (tun)
1375 tun_put(tun);
1376 return ret;
1377 }
1378
1379 static long tun_chr_ioctl(struct file *file,
1380 unsigned int cmd, unsigned long arg)
1381 {
1382 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
1383 }
1384
1385 #ifdef CONFIG_COMPAT
1386 static long tun_chr_compat_ioctl(struct file *file,
1387 unsigned int cmd, unsigned long arg)
1388 {
1389 switch (cmd) {
1390 case TUNSETIFF:
1391 case TUNGETIFF:
1392 case TUNSETTXFILTER:
1393 case TUNGETSNDBUF:
1394 case TUNSETSNDBUF:
1395 case SIOCGIFHWADDR:
1396 case SIOCSIFHWADDR:
1397 arg = (unsigned long)compat_ptr(arg);
1398 break;
1399 default:
1400 arg = (compat_ulong_t)arg;
1401 break;
1402 }
1403
1404 /*
1405 * compat_ifreq is shorter than ifreq, so we must not access beyond
1406 * the end of that structure. All fields that are used in this
1407 * driver are compatible though, we don't need to convert the
1408 * contents.
1409 */
1410 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
1411 }
1412 #endif /* CONFIG_COMPAT */
1413
1414 static int tun_chr_fasync(int fd, struct file *file, int on)
1415 {
1416 struct tun_struct *tun = tun_get(file);
1417 int ret;
1418
1419 if (!tun)
1420 return -EBADFD;
1421
1422 DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);
1423
1424 if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
1425 goto out;
1426
1427 if (on) {
1428 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
1429 if (ret)
1430 goto out;
1431 tun->flags |= TUN_FASYNC;
1432 } else
1433 tun->flags &= ~TUN_FASYNC;
1434 ret = 0;
1435 out:
1436 tun_put(tun);
1437 return ret;
1438 }
1439
1440 static int tun_chr_open(struct inode *inode, struct file * file)
1441 {
1442 struct tun_file *tfile;
1443
1444 DBG1(KERN_INFO "tunX: tun_chr_open\n");
1445
1446 tfile = kmalloc(sizeof(*tfile), GFP_KERNEL);
1447 if (!tfile)
1448 return -ENOMEM;
1449 atomic_set(&tfile->count, 0);
1450 tfile->tun = NULL;
1451 tfile->net = get_net(current->nsproxy->net_ns);
1452 file->private_data = tfile;
1453 return 0;
1454 }
1455
1456 static int tun_chr_close(struct inode *inode, struct file *file)
1457 {
1458 struct tun_file *tfile = file->private_data;
1459 struct tun_struct *tun;
1460
1461 tun = __tun_get(tfile);
1462 if (tun) {
1463 struct net_device *dev = tun->dev;
1464
1465 DBG(KERN_INFO "%s: tun_chr_close\n", dev->name);
1466
1467 __tun_detach(tun);
1468
1469 /* If desirable, unregister the netdevice. */
1470 if (!(tun->flags & TUN_PERSIST)) {
1471 rtnl_lock();
1472 if (dev->reg_state == NETREG_REGISTERED)
1473 unregister_netdevice(dev);
1474 rtnl_unlock();
1475 }
1476 }
1477
1478 tun = tfile->tun;
1479 if (tun)
1480 sock_put(tun->socket.sk);
1481
1482 put_net(tfile->net);
1483 kfree(tfile);
1484
1485 return 0;
1486 }
1487
1488 static const struct file_operations tun_fops = {
1489 .owner = THIS_MODULE,
1490 .llseek = no_llseek,
1491 .read = do_sync_read,
1492 .aio_read = tun_chr_aio_read,
1493 .write = do_sync_write,
1494 .aio_write = tun_chr_aio_write,
1495 .poll = tun_chr_poll,
1496 .unlocked_ioctl = tun_chr_ioctl,
1497 #ifdef CONFIG_COMPAT
1498 .compat_ioctl = tun_chr_compat_ioctl,
1499 #endif
1500 .open = tun_chr_open,
1501 .release = tun_chr_close,
1502 .fasync = tun_chr_fasync
1503 };
1504
1505 static struct miscdevice tun_miscdev = {
1506 .minor = TUN_MINOR,
1507 .name = "tun",
1508 .nodename = "net/tun",
1509 .fops = &tun_fops,
1510 };
1511
1512 /* ethtool interface */
1513
1514 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1515 {
1516 cmd->supported = 0;
1517 cmd->advertising = 0;
1518 cmd->speed = SPEED_10;
1519 cmd->duplex = DUPLEX_FULL;
1520 cmd->port = PORT_TP;
1521 cmd->phy_address = 0;
1522 cmd->transceiver = XCVR_INTERNAL;
1523 cmd->autoneg = AUTONEG_DISABLE;
1524 cmd->maxtxpkt = 0;
1525 cmd->maxrxpkt = 0;
1526 return 0;
1527 }
1528
1529 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
1530 {
1531 struct tun_struct *tun = netdev_priv(dev);
1532
1533 strcpy(info->driver, DRV_NAME);
1534 strcpy(info->version, DRV_VERSION);
1535 strcpy(info->fw_version, "N/A");
1536
1537 switch (tun->flags & TUN_TYPE_MASK) {
1538 case TUN_TUN_DEV:
1539 strcpy(info->bus_info, "tun");
1540 break;
1541 case TUN_TAP_DEV:
1542 strcpy(info->bus_info, "tap");
1543 break;
1544 }
1545 }
1546
1547 static u32 tun_get_msglevel(struct net_device *dev)
1548 {
1549 #ifdef TUN_DEBUG
1550 struct tun_struct *tun = netdev_priv(dev);
1551 return tun->debug;
1552 #else
1553 return -EOPNOTSUPP;
1554 #endif
1555 }
1556
1557 static void tun_set_msglevel(struct net_device *dev, u32 value)
1558 {
1559 #ifdef TUN_DEBUG
1560 struct tun_struct *tun = netdev_priv(dev);
1561 tun->debug = value;
1562 #endif
1563 }
1564
1565 static u32 tun_get_link(struct net_device *dev)
1566 {
1567 struct tun_struct *tun = netdev_priv(dev);
1568 return !!tun->tfile;
1569 }
1570
1571 static u32 tun_get_rx_csum(struct net_device *dev)
1572 {
1573 struct tun_struct *tun = netdev_priv(dev);
1574 return (tun->flags & TUN_NOCHECKSUM) == 0;
1575 }
1576
1577 static int tun_set_rx_csum(struct net_device *dev, u32 data)
1578 {
1579 struct tun_struct *tun = netdev_priv(dev);
1580 if (data)
1581 tun->flags &= ~TUN_NOCHECKSUM;
1582 else
1583 tun->flags |= TUN_NOCHECKSUM;
1584 return 0;
1585 }
1586
1587 static const struct ethtool_ops tun_ethtool_ops = {
1588 .get_settings = tun_get_settings,
1589 .get_drvinfo = tun_get_drvinfo,
1590 .get_msglevel = tun_get_msglevel,
1591 .set_msglevel = tun_set_msglevel,
1592 .get_link = tun_get_link,
1593 .get_rx_csum = tun_get_rx_csum,
1594 .set_rx_csum = tun_set_rx_csum
1595 };
1596
1597
1598 static int __init tun_init(void)
1599 {
1600 int ret = 0;
1601
1602 printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
1603 printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);
1604
1605 ret = rtnl_link_register(&tun_link_ops);
1606 if (ret) {
1607 printk(KERN_ERR "tun: Can't register link_ops\n");
1608 goto err_linkops;
1609 }
1610
1611 ret = misc_register(&tun_miscdev);
1612 if (ret) {
1613 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
1614 goto err_misc;
1615 }
1616 return 0;
1617 err_misc:
1618 rtnl_link_unregister(&tun_link_ops);
1619 err_linkops:
1620 return ret;
1621 }
1622
1623 static void tun_cleanup(void)
1624 {
1625 misc_deregister(&tun_miscdev);
1626 rtnl_link_unregister(&tun_link_ops);
1627 }
1628
1629 /* Get an underlying socket object from tun file. Returns error unless file is
1630 * attached to a device. The returned object works like a packet socket, it
1631 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
1632 * holding a reference to the file for as long as the socket is in use. */
1633 struct socket *tun_get_socket(struct file *file)
1634 {
1635 struct tun_struct *tun;
1636 if (file->f_op != &tun_fops)
1637 return ERR_PTR(-EINVAL);
1638 tun = tun_get(file);
1639 if (!tun)
1640 return ERR_PTR(-EBADFD);
1641 tun_put(tun);
1642 return &tun->socket;
1643 }
1644 EXPORT_SYMBOL_GPL(tun_get_socket);
1645
1646 module_init(tun_init);
1647 module_exit(tun_cleanup);
1648 MODULE_DESCRIPTION(DRV_DESCRIPTION);
1649 MODULE_AUTHOR(DRV_COPYRIGHT);
1650 MODULE_LICENSE("GPL");
1651 MODULE_ALIAS_MISCDEV(TUN_MINOR);
1652 MODULE_ALIAS("devname:net/tun");
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree