2 * TUN - Universal TUN/TAP device driver.
3 * Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com>
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.
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.
15 * $Id: tun.c,v 1.15 2002/03/01 02:44:24 maxk Exp $
21 * Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14
22 * Add TUNSETLINK ioctl to set the link encapsulation
24 * Mark Smith <markzzzsmith@yahoo.com.au>
25 * Use random_ether_addr() for tap MAC address.
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.
33 * Daniel Podlejski <underley@underley.eu.org>
34 * Modifications for 2.3.99-pre5 kernel.
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>"
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/smp_lock.h>
48 #include <linux/poll.h>
49 #include <linux/fcntl.h>
50 #include <linux/init.h>
51 #include <linux/skbuff.h>
52 #include <linux/netdevice.h>
53 #include <linux/etherdevice.h>
54 #include <linux/miscdevice.h>
55 #include <linux/ethtool.h>
56 #include <linux/rtnetlink.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 <net/net_namespace.h>
65 #include <net/netns/generic.h>
66 #include <net/rtnetlink.h>
69 #include <asm/system.h>
70 #include <asm/uaccess.h>
72 /* Uncomment to enable debugging */
73 /* #define TUN_DEBUG 1 */
78 #define DBG if(tun->debug)printk
79 #define DBG1 if(debug==2)printk
85 #define FLT_EXACT_COUNT 8
87 unsigned int count
; /* Number of addrs. Zero means disabled */
88 u32 mask
[2]; /* Mask of the hashed addrs */
89 unsigned char addr
[FLT_EXACT_COUNT
][ETH_ALEN
];
94 struct tun_struct
*tun
;
101 struct tun_file
*tfile
;
106 struct sk_buff_head readq
;
108 struct net_device
*dev
;
109 struct fasync_struct
*fasync
;
111 struct tap_filter txflt
;
113 struct socket socket
;
122 struct tun_struct
*tun
;
125 static inline struct tun_sock
*tun_sk(struct sock
*sk
)
127 return container_of(sk
, struct tun_sock
, sk
);
130 static int tun_attach(struct tun_struct
*tun
, struct file
*file
)
132 struct tun_file
*tfile
= file
->private_data
;
133 const struct cred
*cred
= current_cred();
138 /* Check permissions */
139 if (((tun
->owner
!= -1 && cred
->euid
!= tun
->owner
) ||
140 (tun
->group
!= -1 && !in_egroup_p(tun
->group
))) &&
141 !capable(CAP_NET_ADMIN
))
144 netif_tx_lock_bh(tun
->dev
);
159 atomic_inc(&tfile
->count
);
162 netif_tx_unlock_bh(tun
->dev
);
166 static void __tun_detach(struct tun_struct
*tun
)
168 /* Detach from net device */
169 netif_tx_lock_bh(tun
->dev
);
171 netif_tx_unlock_bh(tun
->dev
);
173 /* Drop read queue */
174 skb_queue_purge(&tun
->readq
);
176 /* Drop the extra count on the net device */
180 static void tun_detach(struct tun_struct
*tun
)
187 static struct tun_struct
*__tun_get(struct tun_file
*tfile
)
189 struct tun_struct
*tun
= NULL
;
191 if (atomic_inc_not_zero(&tfile
->count
))
197 static struct tun_struct
*tun_get(struct file
*file
)
199 return __tun_get(file
->private_data
);
202 static void tun_put(struct tun_struct
*tun
)
204 struct tun_file
*tfile
= tun
->tfile
;
206 if (atomic_dec_and_test(&tfile
->count
))
207 tun_detach(tfile
->tun
);
211 static void addr_hash_set(u32
*mask
, const u8
*addr
)
213 int n
= ether_crc(ETH_ALEN
, addr
) >> 26;
214 mask
[n
>> 5] |= (1 << (n
& 31));
217 static unsigned int addr_hash_test(const u32
*mask
, const u8
*addr
)
219 int n
= ether_crc(ETH_ALEN
, addr
) >> 26;
220 return mask
[n
>> 5] & (1 << (n
& 31));
223 static int update_filter(struct tap_filter
*filter
, void __user
*arg
)
225 struct { u8 u
[ETH_ALEN
]; } *addr
;
226 struct tun_filter uf
;
227 int err
, alen
, n
, nexact
;
229 if (copy_from_user(&uf
, arg
, sizeof(uf
)))
238 alen
= ETH_ALEN
* uf
.count
;
239 addr
= kmalloc(alen
, GFP_KERNEL
);
243 if (copy_from_user(addr
, arg
+ sizeof(uf
), alen
)) {
248 /* The filter is updated without holding any locks. Which is
249 * perfectly safe. We disable it first and in the worst
250 * case we'll accept a few undesired packets. */
254 /* Use first set of addresses as an exact filter */
255 for (n
= 0; n
< uf
.count
&& n
< FLT_EXACT_COUNT
; n
++)
256 memcpy(filter
->addr
[n
], addr
[n
].u
, ETH_ALEN
);
260 /* Remaining multicast addresses are hashed,
261 * unicast will leave the filter disabled. */
262 memset(filter
->mask
, 0, sizeof(filter
->mask
));
263 for (; n
< uf
.count
; n
++) {
264 if (!is_multicast_ether_addr(addr
[n
].u
)) {
265 err
= 0; /* no filter */
268 addr_hash_set(filter
->mask
, addr
[n
].u
);
271 /* For ALLMULTI just set the mask to all ones.
272 * This overrides the mask populated above. */
273 if ((uf
.flags
& TUN_FLT_ALLMULTI
))
274 memset(filter
->mask
, ~0, sizeof(filter
->mask
));
276 /* Now enable the filter */
278 filter
->count
= nexact
;
280 /* Return the number of exact filters */
288 /* Returns: 0 - drop, !=0 - accept */
289 static int run_filter(struct tap_filter
*filter
, const struct sk_buff
*skb
)
291 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
293 struct ethhdr
*eh
= (struct ethhdr
*) skb
->data
;
297 for (i
= 0; i
< filter
->count
; i
++)
298 if (!compare_ether_addr(eh
->h_dest
, filter
->addr
[i
]))
301 /* Inexact match (multicast only) */
302 if (is_multicast_ether_addr(eh
->h_dest
))
303 return addr_hash_test(filter
->mask
, eh
->h_dest
);
309 * Checks whether the packet is accepted or not.
310 * Returns: 0 - drop, !=0 - accept
312 static int check_filter(struct tap_filter
*filter
, const struct sk_buff
*skb
)
317 return run_filter(filter
, skb
);
320 /* Network device part of the driver */
322 static const struct ethtool_ops tun_ethtool_ops
;
324 /* Net device detach from fd. */
325 static void tun_net_uninit(struct net_device
*dev
)
327 struct tun_struct
*tun
= netdev_priv(dev
);
328 struct tun_file
*tfile
= tun
->tfile
;
330 /* Inform the methods they need to stop using the dev.
333 wake_up_all(&tun
->socket
.wait
);
334 if (atomic_dec_and_test(&tfile
->count
))
339 static void tun_free_netdev(struct net_device
*dev
)
341 struct tun_struct
*tun
= netdev_priv(dev
);
346 /* Net device open. */
347 static int tun_net_open(struct net_device
*dev
)
349 netif_start_queue(dev
);
353 /* Net device close. */
354 static int tun_net_close(struct net_device
*dev
)
356 netif_stop_queue(dev
);
360 /* Net device start xmit */
361 static int tun_net_xmit(struct sk_buff
*skb
, struct net_device
*dev
)
363 struct tun_struct
*tun
= netdev_priv(dev
);
365 DBG(KERN_INFO
"%s: tun_net_xmit %d\n", tun
->dev
->name
, skb
->len
);
367 /* Drop packet if interface is not attached */
371 /* Drop if the filter does not like it.
372 * This is a noop if the filter is disabled.
373 * Filter can be enabled only for the TAP devices. */
374 if (!check_filter(&tun
->txflt
, skb
))
377 if (skb_queue_len(&tun
->readq
) >= 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
);
383 /* We won't see all dropped packets individually, so overrun
384 * error is more appropriate. */
385 dev
->stats
.tx_fifo_errors
++;
387 /* Single queue mode.
388 * Driver handles dropping of all packets itself. */
394 skb_queue_tail(&tun
->readq
, skb
);
395 dev
->trans_start
= jiffies
;
397 /* Notify and wake up reader process */
398 if (tun
->flags
& TUN_FASYNC
)
399 kill_fasync(&tun
->fasync
, SIGIO
, POLL_IN
);
400 wake_up_interruptible(&tun
->socket
.wait
);
404 dev
->stats
.tx_dropped
++;
409 static void tun_net_mclist(struct net_device
*dev
)
412 * This callback is supposed to deal with mc filter in
413 * _rx_ path and has nothing to do with the _tx_ path.
414 * In rx path we always accept everything userspace gives us.
420 #define MAX_MTU 65535
423 tun_net_change_mtu(struct net_device
*dev
, int new_mtu
)
425 if (new_mtu
< MIN_MTU
|| new_mtu
+ dev
->hard_header_len
> MAX_MTU
)
431 static const struct net_device_ops tun_netdev_ops
= {
432 .ndo_uninit
= tun_net_uninit
,
433 .ndo_open
= tun_net_open
,
434 .ndo_stop
= tun_net_close
,
435 .ndo_start_xmit
= tun_net_xmit
,
436 .ndo_change_mtu
= tun_net_change_mtu
,
439 static const struct net_device_ops tap_netdev_ops
= {
440 .ndo_uninit
= tun_net_uninit
,
441 .ndo_open
= tun_net_open
,
442 .ndo_stop
= tun_net_close
,
443 .ndo_start_xmit
= tun_net_xmit
,
444 .ndo_change_mtu
= tun_net_change_mtu
,
445 .ndo_set_multicast_list
= tun_net_mclist
,
446 .ndo_set_mac_address
= eth_mac_addr
,
447 .ndo_validate_addr
= eth_validate_addr
,
450 /* Initialize net device. */
451 static void tun_net_init(struct net_device
*dev
)
453 struct tun_struct
*tun
= netdev_priv(dev
);
455 switch (tun
->flags
& TUN_TYPE_MASK
) {
457 dev
->netdev_ops
= &tun_netdev_ops
;
459 /* Point-to-Point TUN Device */
460 dev
->hard_header_len
= 0;
464 /* Zero header length */
465 dev
->type
= ARPHRD_NONE
;
466 dev
->flags
= IFF_POINTOPOINT
| IFF_NOARP
| IFF_MULTICAST
;
467 dev
->tx_queue_len
= TUN_READQ_SIZE
; /* We prefer our own queue length */
471 dev
->netdev_ops
= &tap_netdev_ops
;
472 /* Ethernet TAP Device */
475 random_ether_addr(dev
->dev_addr
);
477 dev
->tx_queue_len
= TUN_READQ_SIZE
; /* We prefer our own queue length */
482 /* Character device part */
485 static unsigned int tun_chr_poll(struct file
*file
, poll_table
* wait
)
487 struct tun_file
*tfile
= file
->private_data
;
488 struct tun_struct
*tun
= __tun_get(tfile
);
489 struct sock
*sk
= tun
->sk
;
490 unsigned int mask
= 0;
495 DBG(KERN_INFO
"%s: tun_chr_poll\n", tun
->dev
->name
);
497 poll_wait(file
, &tun
->socket
.wait
, wait
);
499 if (!skb_queue_empty(&tun
->readq
))
500 mask
|= POLLIN
| POLLRDNORM
;
502 if (sock_writeable(sk
) ||
503 (!test_and_set_bit(SOCK_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
) &&
505 mask
|= POLLOUT
| POLLWRNORM
;
507 if (tun
->dev
->reg_state
!= NETREG_REGISTERED
)
514 /* prepad is the amount to reserve at front. len is length after that.
515 * linear is a hint as to how much to copy (usually headers). */
516 static inline struct sk_buff
*tun_alloc_skb(struct tun_struct
*tun
,
517 size_t prepad
, size_t len
,
518 size_t linear
, int noblock
)
520 struct sock
*sk
= tun
->sk
;
524 /* Under a page? Don't bother with paged skb. */
525 if (prepad
+ len
< PAGE_SIZE
|| !linear
)
528 skb
= sock_alloc_send_pskb(sk
, prepad
+ linear
, len
- linear
, noblock
,
533 skb_reserve(skb
, prepad
);
534 skb_put(skb
, linear
);
535 skb
->data_len
= len
- linear
;
536 skb
->len
+= len
- linear
;
541 /* Get packet from user space buffer */
542 static __inline__ ssize_t
tun_get_user(struct tun_struct
*tun
,
543 const struct iovec
*iv
, size_t count
,
546 struct tun_pi pi
= { 0, cpu_to_be16(ETH_P_IP
) };
548 size_t len
= count
, align
= 0;
549 struct virtio_net_hdr gso
= { 0 };
552 if (!(tun
->flags
& TUN_NO_PI
)) {
553 if ((len
-= sizeof(pi
)) > count
)
556 if (memcpy_fromiovecend((void *)&pi
, iv
, 0, sizeof(pi
)))
558 offset
+= sizeof(pi
);
561 if (tun
->flags
& TUN_VNET_HDR
) {
562 if ((len
-= sizeof(gso
)) > count
)
565 if (memcpy_fromiovecend((void *)&gso
, iv
, offset
, sizeof(gso
)))
568 if ((gso
.flags
& VIRTIO_NET_HDR_F_NEEDS_CSUM
) &&
569 gso
.csum_start
+ gso
.csum_offset
+ 2 > gso
.hdr_len
)
570 gso
.hdr_len
= gso
.csum_start
+ gso
.csum_offset
+ 2;
572 if (gso
.hdr_len
> len
)
574 offset
+= sizeof(gso
);
577 if ((tun
->flags
& TUN_TYPE_MASK
) == TUN_TAP_DEV
) {
578 align
= NET_IP_ALIGN
;
579 if (unlikely(len
< ETH_HLEN
||
580 (gso
.hdr_len
&& gso
.hdr_len
< ETH_HLEN
)))
584 skb
= tun_alloc_skb(tun
, align
, len
, gso
.hdr_len
, noblock
);
586 if (PTR_ERR(skb
) != -EAGAIN
)
587 tun
->dev
->stats
.rx_dropped
++;
591 if (skb_copy_datagram_from_iovec(skb
, 0, iv
, offset
, len
)) {
592 tun
->dev
->stats
.rx_dropped
++;
597 if (gso
.flags
& VIRTIO_NET_HDR_F_NEEDS_CSUM
) {
598 if (!skb_partial_csum_set(skb
, gso
.csum_start
,
600 tun
->dev
->stats
.rx_frame_errors
++;
604 } else if (tun
->flags
& TUN_NOCHECKSUM
)
605 skb
->ip_summed
= CHECKSUM_UNNECESSARY
;
607 switch (tun
->flags
& TUN_TYPE_MASK
) {
609 if (tun
->flags
& TUN_NO_PI
) {
610 switch (skb
->data
[0] & 0xf0) {
612 pi
.proto
= htons(ETH_P_IP
);
615 pi
.proto
= htons(ETH_P_IPV6
);
618 tun
->dev
->stats
.rx_dropped
++;
624 skb_reset_mac_header(skb
);
625 skb
->protocol
= pi
.proto
;
629 skb
->protocol
= eth_type_trans(skb
, tun
->dev
);
633 if (gso
.gso_type
!= VIRTIO_NET_HDR_GSO_NONE
) {
635 switch (gso
.gso_type
& ~VIRTIO_NET_HDR_GSO_ECN
) {
636 case VIRTIO_NET_HDR_GSO_TCPV4
:
637 skb_shinfo(skb
)->gso_type
= SKB_GSO_TCPV4
;
639 case VIRTIO_NET_HDR_GSO_TCPV6
:
640 skb_shinfo(skb
)->gso_type
= SKB_GSO_TCPV6
;
643 tun
->dev
->stats
.rx_frame_errors
++;
648 if (gso
.gso_type
& VIRTIO_NET_HDR_GSO_ECN
)
649 skb_shinfo(skb
)->gso_type
|= SKB_GSO_TCP_ECN
;
651 skb_shinfo(skb
)->gso_size
= gso
.gso_size
;
652 if (skb_shinfo(skb
)->gso_size
== 0) {
653 tun
->dev
->stats
.rx_frame_errors
++;
658 /* Header must be checked, and gso_segs computed. */
659 skb_shinfo(skb
)->gso_type
|= SKB_GSO_DODGY
;
660 skb_shinfo(skb
)->gso_segs
= 0;
665 tun
->dev
->stats
.rx_packets
++;
666 tun
->dev
->stats
.rx_bytes
+= len
;
671 static ssize_t
tun_chr_aio_write(struct kiocb
*iocb
, const struct iovec
*iv
,
672 unsigned long count
, loff_t pos
)
674 struct file
*file
= iocb
->ki_filp
;
675 struct tun_struct
*tun
= tun_get(file
);
681 DBG(KERN_INFO
"%s: tun_chr_write %ld\n", tun
->dev
->name
, count
);
683 result
= tun_get_user(tun
, iv
, iov_length(iv
, count
),
684 file
->f_flags
& O_NONBLOCK
);
690 /* Put packet to the user space buffer */
691 static __inline__ ssize_t
tun_put_user(struct tun_struct
*tun
,
693 const struct iovec
*iv
, int len
)
695 struct tun_pi pi
= { 0, skb
->protocol
};
698 if (!(tun
->flags
& TUN_NO_PI
)) {
699 if ((len
-= sizeof(pi
)) < 0)
702 if (len
< skb
->len
) {
703 /* Packet will be striped */
704 pi
.flags
|= TUN_PKT_STRIP
;
707 if (memcpy_toiovecend(iv
, (void *) &pi
, 0, sizeof(pi
)))
712 if (tun
->flags
& TUN_VNET_HDR
) {
713 struct virtio_net_hdr gso
= { 0 }; /* no info leak */
714 if ((len
-= sizeof(gso
)) < 0)
717 if (skb_is_gso(skb
)) {
718 struct skb_shared_info
*sinfo
= skb_shinfo(skb
);
720 /* This is a hint as to how much should be linear. */
721 gso
.hdr_len
= skb_headlen(skb
);
722 gso
.gso_size
= sinfo
->gso_size
;
723 if (sinfo
->gso_type
& SKB_GSO_TCPV4
)
724 gso
.gso_type
= VIRTIO_NET_HDR_GSO_TCPV4
;
725 else if (sinfo
->gso_type
& SKB_GSO_TCPV6
)
726 gso
.gso_type
= VIRTIO_NET_HDR_GSO_TCPV6
;
729 if (sinfo
->gso_type
& SKB_GSO_TCP_ECN
)
730 gso
.gso_type
|= VIRTIO_NET_HDR_GSO_ECN
;
732 gso
.gso_type
= VIRTIO_NET_HDR_GSO_NONE
;
734 if (skb
->ip_summed
== CHECKSUM_PARTIAL
) {
735 gso
.flags
= VIRTIO_NET_HDR_F_NEEDS_CSUM
;
736 gso
.csum_start
= skb
->csum_start
- skb_headroom(skb
);
737 gso
.csum_offset
= skb
->csum_offset
;
738 } /* else everything is zero */
740 if (unlikely(memcpy_toiovecend(iv
, (void *)&gso
, total
,
743 total
+= sizeof(gso
);
746 len
= min_t(int, skb
->len
, len
);
748 skb_copy_datagram_const_iovec(skb
, 0, iv
, total
, len
);
751 tun
->dev
->stats
.tx_packets
++;
752 tun
->dev
->stats
.tx_bytes
+= len
;
757 static ssize_t
tun_chr_aio_read(struct kiocb
*iocb
, const struct iovec
*iv
,
758 unsigned long count
, loff_t pos
)
760 struct file
*file
= iocb
->ki_filp
;
761 struct tun_file
*tfile
= file
->private_data
;
762 struct tun_struct
*tun
= __tun_get(tfile
);
763 DECLARE_WAITQUEUE(wait
, current
);
765 ssize_t len
, ret
= 0;
770 DBG(KERN_INFO
"%s: tun_chr_read\n", tun
->dev
->name
);
772 len
= iov_length(iv
, count
);
778 add_wait_queue(&tun
->socket
.wait
, &wait
);
780 current
->state
= TASK_INTERRUPTIBLE
;
782 /* Read frames from the queue */
783 if (!(skb
=skb_dequeue(&tun
->readq
))) {
784 if (file
->f_flags
& O_NONBLOCK
) {
788 if (signal_pending(current
)) {
792 if (tun
->dev
->reg_state
!= NETREG_REGISTERED
) {
797 /* Nothing to read, let's sleep */
801 netif_wake_queue(tun
->dev
);
803 ret
= tun_put_user(tun
, skb
, iv
, len
);
808 current
->state
= TASK_RUNNING
;
809 remove_wait_queue(&tun
->socket
.wait
, &wait
);
816 static void tun_setup(struct net_device
*dev
)
818 struct tun_struct
*tun
= netdev_priv(dev
);
820 skb_queue_head_init(&tun
->readq
);
825 dev
->ethtool_ops
= &tun_ethtool_ops
;
826 dev
->destructor
= tun_free_netdev
;
829 /* Trivial set of netlink ops to allow deleting tun or tap
830 * device with netlink.
832 static int tun_validate(struct nlattr
*tb
[], struct nlattr
*data
[])
837 static struct rtnl_link_ops tun_link_ops __read_mostly
= {
839 .priv_size
= sizeof(struct tun_struct
),
841 .validate
= tun_validate
,
844 static void tun_sock_write_space(struct sock
*sk
)
846 struct tun_struct
*tun
;
848 if (!sock_writeable(sk
))
851 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
))
854 if (sk
->sk_sleep
&& waitqueue_active(sk
->sk_sleep
))
855 wake_up_interruptible_sync(sk
->sk_sleep
);
857 tun
= container_of(sk
, struct tun_sock
, sk
)->tun
;
858 kill_fasync(&tun
->fasync
, SIGIO
, POLL_OUT
);
861 static void tun_sock_destruct(struct sock
*sk
)
863 free_netdev(container_of(sk
, struct tun_sock
, sk
)->tun
->dev
);
866 static struct proto tun_proto
= {
868 .owner
= THIS_MODULE
,
869 .obj_size
= sizeof(struct tun_sock
),
872 static int tun_flags(struct tun_struct
*tun
)
876 if (tun
->flags
& TUN_TUN_DEV
)
881 if (tun
->flags
& TUN_NO_PI
)
884 if (tun
->flags
& TUN_ONE_QUEUE
)
885 flags
|= IFF_ONE_QUEUE
;
887 if (tun
->flags
& TUN_VNET_HDR
)
888 flags
|= IFF_VNET_HDR
;
893 static ssize_t
tun_show_flags(struct device
*dev
, struct device_attribute
*attr
,
896 struct tun_struct
*tun
= netdev_priv(to_net_dev(dev
));
897 return sprintf(buf
, "0x%x\n", tun_flags(tun
));
900 static ssize_t
tun_show_owner(struct device
*dev
, struct device_attribute
*attr
,
903 struct tun_struct
*tun
= netdev_priv(to_net_dev(dev
));
904 return sprintf(buf
, "%d\n", tun
->owner
);
907 static ssize_t
tun_show_group(struct device
*dev
, struct device_attribute
*attr
,
910 struct tun_struct
*tun
= netdev_priv(to_net_dev(dev
));
911 return sprintf(buf
, "%d\n", tun
->group
);
914 static DEVICE_ATTR(tun_flags
, 0444, tun_show_flags
, NULL
);
915 static DEVICE_ATTR(owner
, 0444, tun_show_owner
, NULL
);
916 static DEVICE_ATTR(group
, 0444, tun_show_group
, NULL
);
918 static int tun_set_iff(struct net
*net
, struct file
*file
, struct ifreq
*ifr
)
921 struct tun_struct
*tun
;
922 struct net_device
*dev
;
925 dev
= __dev_get_by_name(net
, ifr
->ifr_name
);
927 if (ifr
->ifr_flags
& IFF_TUN_EXCL
)
929 if ((ifr
->ifr_flags
& IFF_TUN
) && dev
->netdev_ops
== &tun_netdev_ops
)
930 tun
= netdev_priv(dev
);
931 else if ((ifr
->ifr_flags
& IFF_TAP
) && dev
->netdev_ops
== &tap_netdev_ops
)
932 tun
= netdev_priv(dev
);
936 err
= tun_attach(tun
, file
);
942 unsigned long flags
= 0;
946 if (!capable(CAP_NET_ADMIN
))
950 if (ifr
->ifr_flags
& IFF_TUN
) {
952 flags
|= TUN_TUN_DEV
;
954 } else if (ifr
->ifr_flags
& IFF_TAP
) {
956 flags
|= TUN_TAP_DEV
;
962 name
= ifr
->ifr_name
;
964 dev
= alloc_netdev(sizeof(struct tun_struct
), name
,
969 dev_net_set(dev
, net
);
970 dev
->rtnl_link_ops
= &tun_link_ops
;
972 tun
= netdev_priv(dev
);
975 tun
->txflt
.count
= 0;
978 sk
= sk_alloc(net
, AF_UNSPEC
, GFP_KERNEL
, &tun_proto
);
982 init_waitqueue_head(&tun
->socket
.wait
);
983 sock_init_data(&tun
->socket
, sk
);
984 sk
->sk_write_space
= tun_sock_write_space
;
985 sk
->sk_sndbuf
= INT_MAX
;
988 container_of(sk
, struct tun_sock
, sk
)->tun
= tun
;
992 if (strchr(dev
->name
, '%')) {
993 err
= dev_alloc_name(dev
, dev
->name
);
999 err
= register_netdevice(tun
->dev
);
1003 if (device_create_file(&tun
->dev
->dev
, &dev_attr_tun_flags
) ||
1004 device_create_file(&tun
->dev
->dev
, &dev_attr_owner
) ||
1005 device_create_file(&tun
->dev
->dev
, &dev_attr_group
))
1006 printk(KERN_ERR
"Failed to create tun sysfs files\n");
1008 sk
->sk_destruct
= tun_sock_destruct
;
1010 err
= tun_attach(tun
, file
);
1015 DBG(KERN_INFO
"%s: tun_set_iff\n", tun
->dev
->name
);
1017 if (ifr
->ifr_flags
& IFF_NO_PI
)
1018 tun
->flags
|= TUN_NO_PI
;
1020 tun
->flags
&= ~TUN_NO_PI
;
1022 if (ifr
->ifr_flags
& IFF_ONE_QUEUE
)
1023 tun
->flags
|= TUN_ONE_QUEUE
;
1025 tun
->flags
&= ~TUN_ONE_QUEUE
;
1027 if (ifr
->ifr_flags
& IFF_VNET_HDR
)
1028 tun
->flags
|= TUN_VNET_HDR
;
1030 tun
->flags
&= ~TUN_VNET_HDR
;
1032 /* Make sure persistent devices do not get stuck in
1035 if (netif_running(tun
->dev
))
1036 netif_wake_queue(tun
->dev
);
1038 strcpy(ifr
->ifr_name
, tun
->dev
->name
);
1049 static int tun_get_iff(struct net
*net
, struct file
*file
, struct ifreq
*ifr
)
1051 struct tun_struct
*tun
= tun_get(file
);
1056 DBG(KERN_INFO
"%s: tun_get_iff\n", tun
->dev
->name
);
1058 strcpy(ifr
->ifr_name
, tun
->dev
->name
);
1060 ifr
->ifr_flags
= tun_flags(tun
);
1066 /* This is like a cut-down ethtool ops, except done via tun fd so no
1067 * privs required. */
1068 static int set_offload(struct net_device
*dev
, unsigned long arg
)
1070 unsigned int old_features
, features
;
1072 old_features
= dev
->features
;
1073 /* Unset features, set them as we chew on the arg. */
1074 features
= (old_features
& ~(NETIF_F_HW_CSUM
|NETIF_F_SG
|NETIF_F_FRAGLIST
1075 |NETIF_F_TSO_ECN
|NETIF_F_TSO
|NETIF_F_TSO6
));
1077 if (arg
& TUN_F_CSUM
) {
1078 features
|= NETIF_F_HW_CSUM
|NETIF_F_SG
|NETIF_F_FRAGLIST
;
1081 if (arg
& (TUN_F_TSO4
|TUN_F_TSO6
)) {
1082 if (arg
& TUN_F_TSO_ECN
) {
1083 features
|= NETIF_F_TSO_ECN
;
1084 arg
&= ~TUN_F_TSO_ECN
;
1086 if (arg
& TUN_F_TSO4
)
1087 features
|= NETIF_F_TSO
;
1088 if (arg
& TUN_F_TSO6
)
1089 features
|= NETIF_F_TSO6
;
1090 arg
&= ~(TUN_F_TSO4
|TUN_F_TSO6
);
1094 /* This gives the user a way to test for new features in future by
1095 * trying to set them. */
1099 dev
->features
= features
;
1100 if (old_features
!= dev
->features
)
1101 netdev_features_change(dev
);
1106 static int tun_chr_ioctl(struct inode
*inode
, struct file
*file
,
1107 unsigned int cmd
, unsigned long arg
)
1109 struct tun_file
*tfile
= file
->private_data
;
1110 struct tun_struct
*tun
;
1111 void __user
* argp
= (void __user
*)arg
;
1116 if (cmd
== TUNSETIFF
|| _IOC_TYPE(cmd
) == 0x89)
1117 if (copy_from_user(&ifr
, argp
, sizeof ifr
))
1120 if (cmd
== TUNGETFEATURES
) {
1121 /* Currently this just means: "what IFF flags are valid?".
1122 * This is needed because we never checked for invalid flags on
1124 return put_user(IFF_TUN
| IFF_TAP
| IFF_NO_PI
| IFF_ONE_QUEUE
|
1126 (unsigned int __user
*)argp
);
1129 tun
= __tun_get(tfile
);
1130 if (cmd
== TUNSETIFF
&& !tun
) {
1133 ifr
.ifr_name
[IFNAMSIZ
-1] = '\0';
1136 err
= tun_set_iff(tfile
->net
, file
, &ifr
);
1142 if (copy_to_user(argp
, &ifr
, sizeof(ifr
)))
1151 DBG(KERN_INFO
"%s: tun_chr_ioctl cmd %d\n", tun
->dev
->name
, cmd
);
1156 ret
= tun_get_iff(current
->nsproxy
->net_ns
, file
, &ifr
);
1160 if (copy_to_user(argp
, &ifr
, sizeof(ifr
)))
1165 /* Disable/Enable checksum */
1167 tun
->flags
|= TUN_NOCHECKSUM
;
1169 tun
->flags
&= ~TUN_NOCHECKSUM
;
1171 DBG(KERN_INFO
"%s: checksum %s\n",
1172 tun
->dev
->name
, arg
? "disabled" : "enabled");
1176 /* Disable/Enable persist mode */
1178 tun
->flags
|= TUN_PERSIST
;
1180 tun
->flags
&= ~TUN_PERSIST
;
1182 DBG(KERN_INFO
"%s: persist %s\n",
1183 tun
->dev
->name
, arg
? "enabled" : "disabled");
1187 /* Set owner of the device */
1188 tun
->owner
= (uid_t
) arg
;
1190 DBG(KERN_INFO
"%s: owner set to %d\n", tun
->dev
->name
, tun
->owner
);
1194 /* Set group of the device */
1195 tun
->group
= (gid_t
) arg
;
1197 DBG(KERN_INFO
"%s: group set to %d\n", tun
->dev
->name
, tun
->group
);
1201 /* Only allow setting the type when the interface is down */
1203 if (tun
->dev
->flags
& IFF_UP
) {
1204 DBG(KERN_INFO
"%s: Linktype set failed because interface is up\n",
1208 tun
->dev
->type
= (int) arg
;
1209 DBG(KERN_INFO
"%s: linktype set to %d\n", tun
->dev
->name
, tun
->dev
->type
);
1222 ret
= set_offload(tun
->dev
, arg
);
1226 case TUNSETTXFILTER
:
1227 /* Can be set only for TAPs */
1229 if ((tun
->flags
& TUN_TYPE_MASK
) != TUN_TAP_DEV
)
1232 ret
= update_filter(&tun
->txflt
, (void __user
*)arg
);
1238 memcpy(ifr
.ifr_hwaddr
.sa_data
, tun
->dev
->dev_addr
, ETH_ALEN
);
1239 ifr
.ifr_hwaddr
.sa_family
= tun
->dev
->type
;
1240 if (copy_to_user(argp
, &ifr
, sizeof ifr
))
1245 /* Set hw address */
1246 DBG(KERN_DEBUG
"%s: set hw address: %pM\n",
1247 tun
->dev
->name
, ifr
.ifr_hwaddr
.sa_data
);
1250 ret
= dev_set_mac_address(tun
->dev
, &ifr
.ifr_hwaddr
);
1255 sndbuf
= tun
->sk
->sk_sndbuf
;
1256 if (copy_to_user(argp
, &sndbuf
, sizeof(sndbuf
)))
1261 if (copy_from_user(&sndbuf
, argp
, sizeof(sndbuf
))) {
1266 tun
->sk
->sk_sndbuf
= sndbuf
;
1278 static int tun_chr_fasync(int fd
, struct file
*file
, int on
)
1280 struct tun_struct
*tun
= tun_get(file
);
1286 DBG(KERN_INFO
"%s: tun_chr_fasync %d\n", tun
->dev
->name
, on
);
1289 if ((ret
= fasync_helper(fd
, file
, on
, &tun
->fasync
)) < 0)
1293 ret
= __f_setown(file
, task_pid(current
), PIDTYPE_PID
, 0);
1296 tun
->flags
|= TUN_FASYNC
;
1298 tun
->flags
&= ~TUN_FASYNC
;
1306 static int tun_chr_open(struct inode
*inode
, struct file
* file
)
1308 struct tun_file
*tfile
;
1309 cycle_kernel_lock();
1310 DBG1(KERN_INFO
"tunX: tun_chr_open\n");
1312 tfile
= kmalloc(sizeof(*tfile
), GFP_KERNEL
);
1315 atomic_set(&tfile
->count
, 0);
1317 tfile
->net
= get_net(current
->nsproxy
->net_ns
);
1318 file
->private_data
= tfile
;
1322 static int tun_chr_close(struct inode
*inode
, struct file
*file
)
1324 struct tun_file
*tfile
= file
->private_data
;
1325 struct tun_struct
*tun
;
1329 tun
= __tun_get(tfile
);
1331 DBG(KERN_INFO
"%s: tun_chr_close\n", tun
->dev
->name
);
1335 /* If desireable, unregister the netdevice. */
1336 if (!(tun
->flags
& TUN_PERSIST
))
1337 unregister_netdevice(tun
->dev
);
1346 put_net(tfile
->net
);
1352 static const struct file_operations tun_fops
= {
1353 .owner
= THIS_MODULE
,
1354 .llseek
= no_llseek
,
1355 .read
= do_sync_read
,
1356 .aio_read
= tun_chr_aio_read
,
1357 .write
= do_sync_write
,
1358 .aio_write
= tun_chr_aio_write
,
1359 .poll
= tun_chr_poll
,
1360 .ioctl
= tun_chr_ioctl
,
1361 .open
= tun_chr_open
,
1362 .release
= tun_chr_close
,
1363 .fasync
= tun_chr_fasync
1366 static struct miscdevice tun_miscdev
= {
1369 .devnode
= "net/tun",
1373 /* ethtool interface */
1375 static int tun_get_settings(struct net_device
*dev
, struct ethtool_cmd
*cmd
)
1378 cmd
->advertising
= 0;
1379 cmd
->speed
= SPEED_10
;
1380 cmd
->duplex
= DUPLEX_FULL
;
1381 cmd
->port
= PORT_TP
;
1382 cmd
->phy_address
= 0;
1383 cmd
->transceiver
= XCVR_INTERNAL
;
1384 cmd
->autoneg
= AUTONEG_DISABLE
;
1390 static void tun_get_drvinfo(struct net_device
*dev
, struct ethtool_drvinfo
*info
)
1392 struct tun_struct
*tun
= netdev_priv(dev
);
1394 strcpy(info
->driver
, DRV_NAME
);
1395 strcpy(info
->version
, DRV_VERSION
);
1396 strcpy(info
->fw_version
, "N/A");
1398 switch (tun
->flags
& TUN_TYPE_MASK
) {
1400 strcpy(info
->bus_info
, "tun");
1403 strcpy(info
->bus_info
, "tap");
1408 static u32
tun_get_msglevel(struct net_device
*dev
)
1411 struct tun_struct
*tun
= netdev_priv(dev
);
1418 static void tun_set_msglevel(struct net_device
*dev
, u32 value
)
1421 struct tun_struct
*tun
= netdev_priv(dev
);
1426 static u32
tun_get_link(struct net_device
*dev
)
1428 struct tun_struct
*tun
= netdev_priv(dev
);
1429 return !!tun
->tfile
;
1432 static u32
tun_get_rx_csum(struct net_device
*dev
)
1434 struct tun_struct
*tun
= netdev_priv(dev
);
1435 return (tun
->flags
& TUN_NOCHECKSUM
) == 0;
1438 static int tun_set_rx_csum(struct net_device
*dev
, u32 data
)
1440 struct tun_struct
*tun
= netdev_priv(dev
);
1442 tun
->flags
&= ~TUN_NOCHECKSUM
;
1444 tun
->flags
|= TUN_NOCHECKSUM
;
1448 static const struct ethtool_ops tun_ethtool_ops
= {
1449 .get_settings
= tun_get_settings
,
1450 .get_drvinfo
= tun_get_drvinfo
,
1451 .get_msglevel
= tun_get_msglevel
,
1452 .set_msglevel
= tun_set_msglevel
,
1453 .get_link
= tun_get_link
,
1454 .get_rx_csum
= tun_get_rx_csum
,
1455 .set_rx_csum
= tun_set_rx_csum
1459 static int __init
tun_init(void)
1463 printk(KERN_INFO
"tun: %s, %s\n", DRV_DESCRIPTION
, DRV_VERSION
);
1464 printk(KERN_INFO
"tun: %s\n", DRV_COPYRIGHT
);
1466 ret
= rtnl_link_register(&tun_link_ops
);
1468 printk(KERN_ERR
"tun: Can't register link_ops\n");
1472 ret
= misc_register(&tun_miscdev
);
1474 printk(KERN_ERR
"tun: Can't register misc device %d\n", TUN_MINOR
);
1479 rtnl_link_unregister(&tun_link_ops
);
1484 static void tun_cleanup(void)
1486 misc_deregister(&tun_miscdev
);
1487 rtnl_link_unregister(&tun_link_ops
);
1490 module_init(tun_init
);
1491 module_exit(tun_cleanup
);
1492 MODULE_DESCRIPTION(DRV_DESCRIPTION
);
1493 MODULE_AUTHOR(DRV_COPYRIGHT
);
1494 MODULE_LICENSE("GPL");
1495 MODULE_ALIAS_MISCDEV(TUN_MINOR
);