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 pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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>"
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>
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>
72 #include <asm/system.h>
73 #include <asm/uaccess.h>
75 /* Uncomment to enable debugging */
76 /* #define TUN_DEBUG 1 */
81 #define tun_debug(level, tun, fmt, args...) \
84 netdev_printk(level, tun->dev, fmt, ##args); \
86 #define DBG1(level, fmt, args...) \
89 printk(level fmt, ##args); \
92 #define tun_debug(level, tun, fmt, args...) \
95 netdev_printk(level, tun->dev, fmt, ##args); \
97 #define DBG1(level, fmt, args...) \
100 printk(level fmt, ##args); \
104 #define FLT_EXACT_COUNT 8
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
];
113 struct tun_struct
*tun
;
120 struct tun_file
*tfile
;
125 struct net_device
*dev
;
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
;
131 struct tap_filter txflt
;
132 struct socket socket
;
144 struct tun_struct
*tun
;
147 static inline struct tun_sock
*tun_sk(struct sock
*sk
)
149 return container_of(sk
, struct tun_sock
, sk
);
152 static int tun_attach(struct tun_struct
*tun
, struct file
*file
)
154 struct tun_file
*tfile
= file
->private_data
;
159 netif_tx_lock_bh(tun
->dev
);
172 tun
->socket
.file
= file
;
173 netif_carrier_on(tun
->dev
);
175 sock_hold(tun
->socket
.sk
);
176 atomic_inc(&tfile
->count
);
179 netif_tx_unlock_bh(tun
->dev
);
183 static void __tun_detach(struct tun_struct
*tun
)
185 /* Detach from net device */
186 netif_tx_lock_bh(tun
->dev
);
187 netif_carrier_off(tun
->dev
);
189 tun
->socket
.file
= NULL
;
190 netif_tx_unlock_bh(tun
->dev
);
192 /* Drop read queue */
193 skb_queue_purge(&tun
->socket
.sk
->sk_receive_queue
);
195 /* Drop the extra count on the net device */
199 static void tun_detach(struct tun_struct
*tun
)
206 static struct tun_struct
*__tun_get(struct tun_file
*tfile
)
208 struct tun_struct
*tun
= NULL
;
210 if (atomic_inc_not_zero(&tfile
->count
))
216 static struct tun_struct
*tun_get(struct file
*file
)
218 return __tun_get(file
->private_data
);
221 static void tun_put(struct tun_struct
*tun
)
223 struct tun_file
*tfile
= tun
->tfile
;
225 if (atomic_dec_and_test(&tfile
->count
))
226 tun_detach(tfile
->tun
);
230 static void addr_hash_set(u32
*mask
, const u8
*addr
)
232 int n
= ether_crc(ETH_ALEN
, addr
) >> 26;
233 mask
[n
>> 5] |= (1 << (n
& 31));
236 static unsigned int addr_hash_test(const u32
*mask
, const u8
*addr
)
238 int n
= ether_crc(ETH_ALEN
, addr
) >> 26;
239 return mask
[n
>> 5] & (1 << (n
& 31));
242 static int update_filter(struct tap_filter
*filter
, void __user
*arg
)
244 struct { u8 u
[ETH_ALEN
]; } *addr
;
245 struct tun_filter uf
;
246 int err
, alen
, n
, nexact
;
248 if (copy_from_user(&uf
, arg
, sizeof(uf
)))
257 alen
= ETH_ALEN
* uf
.count
;
258 addr
= kmalloc(alen
, GFP_KERNEL
);
262 if (copy_from_user(addr
, arg
+ sizeof(uf
), alen
)) {
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. */
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
);
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 */
287 addr_hash_set(filter
->mask
, addr
[n
].u
);
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
));
295 /* Now enable the filter */
297 filter
->count
= nexact
;
299 /* Return the number of exact filters */
307 /* Returns: 0 - drop, !=0 - accept */
308 static int run_filter(struct tap_filter
*filter
, const struct sk_buff
*skb
)
310 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
312 struct ethhdr
*eh
= (struct ethhdr
*) skb
->data
;
316 for (i
= 0; i
< filter
->count
; i
++)
317 if (!compare_ether_addr(eh
->h_dest
, filter
->addr
[i
]))
320 /* Inexact match (multicast only) */
321 if (is_multicast_ether_addr(eh
->h_dest
))
322 return addr_hash_test(filter
->mask
, eh
->h_dest
);
328 * Checks whether the packet is accepted or not.
329 * Returns: 0 - drop, !=0 - accept
331 static int check_filter(struct tap_filter
*filter
, const struct sk_buff
*skb
)
336 return run_filter(filter
, skb
);
339 /* Network device part of the driver */
341 static const struct ethtool_ops tun_ethtool_ops
;
343 /* Net device detach from fd. */
344 static void tun_net_uninit(struct net_device
*dev
)
346 struct tun_struct
*tun
= netdev_priv(dev
);
347 struct tun_file
*tfile
= tun
->tfile
;
349 /* Inform the methods they need to stop using the dev.
352 wake_up_all(&tun
->wq
.wait
);
353 if (atomic_dec_and_test(&tfile
->count
))
358 static void tun_free_netdev(struct net_device
*dev
)
360 struct tun_struct
*tun
= netdev_priv(dev
);
362 sock_put(tun
->socket
.sk
);
365 /* Net device open. */
366 static int tun_net_open(struct net_device
*dev
)
368 netif_start_queue(dev
);
372 /* Net device close. */
373 static int tun_net_close(struct net_device
*dev
)
375 netif_stop_queue(dev
);
379 /* Net device start xmit */
380 static netdev_tx_t
tun_net_xmit(struct sk_buff
*skb
, struct net_device
*dev
)
382 struct tun_struct
*tun
= netdev_priv(dev
);
384 tun_debug(KERN_INFO
, tun
, "tun_net_xmit %d\n", skb
->len
);
386 /* Drop packet if interface is not attached */
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
))
396 if (tun
->socket
.sk
->sk_filter
&&
397 sk_filter(tun
->socket
.sk
, skb
))
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
);
406 /* We won't see all dropped packets individually, so overrun
407 * error is more appropriate. */
408 dev
->stats
.tx_fifo_errors
++;
410 /* Single queue mode.
411 * Driver handles dropping of all packets itself. */
416 /* Orphan the skb - required as we might hang on to it
417 * for indefinite time. */
421 skb_queue_tail(&tun
->socket
.sk
->sk_receive_queue
, skb
);
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
);
431 dev
->stats
.tx_dropped
++;
436 static void tun_net_mclist(struct net_device
*dev
)
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.
446 #define MAX_MTU 65535
449 tun_net_change_mtu(struct net_device
*dev
, int new_mtu
)
451 if (new_mtu
< MIN_MTU
|| new_mtu
+ dev
->hard_header_len
> MAX_MTU
)
457 static u32
tun_net_fix_features(struct net_device
*dev
, u32 features
)
459 struct tun_struct
*tun
= netdev_priv(dev
);
461 return (features
& tun
->set_features
) | (features
& ~TUN_USER_FEATURES
);
463 #ifdef CONFIG_NET_POLL_CONTROLLER
464 static void tun_poll_controller(struct net_device
*dev
)
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
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
,
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
,
507 /* Initialize net device. */
508 static void tun_net_init(struct net_device
*dev
)
510 struct tun_struct
*tun
= netdev_priv(dev
);
512 switch (tun
->flags
& TUN_TYPE_MASK
) {
514 dev
->netdev_ops
= &tun_netdev_ops
;
516 /* Point-to-Point TUN Device */
517 dev
->hard_header_len
= 0;
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 */
528 dev
->netdev_ops
= &tap_netdev_ops
;
529 /* Ethernet TAP Device */
531 dev
->priv_flags
&= ~IFF_TX_SKB_SHARING
;
533 random_ether_addr(dev
->dev_addr
);
535 dev
->tx_queue_len
= TUN_READQ_SIZE
; /* We prefer our own queue length */
540 /* Character device part */
543 static unsigned int tun_chr_poll(struct file
*file
, poll_table
* wait
)
545 struct tun_file
*tfile
= file
->private_data
;
546 struct tun_struct
*tun
= __tun_get(tfile
);
548 unsigned int mask
= 0;
555 tun_debug(KERN_INFO
, tun
, "tun_chr_poll\n");
557 poll_wait(file
, &tun
->wq
.wait
, wait
);
559 if (!skb_queue_empty(&sk
->sk_receive_queue
))
560 mask
|= POLLIN
| POLLRDNORM
;
562 if (sock_writeable(sk
) ||
563 (!test_and_set_bit(SOCK_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
) &&
565 mask
|= POLLOUT
| POLLWRNORM
;
567 if (tun
->dev
->reg_state
!= NETREG_REGISTERED
)
574 /* prepad is the amount to reserve at front. len is length after that.
575 * linear is a hint as to how much to copy (usually headers). */
576 static struct sk_buff
*tun_alloc_skb(struct tun_struct
*tun
,
577 size_t prepad
, size_t len
,
578 size_t linear
, int noblock
)
580 struct sock
*sk
= tun
->socket
.sk
;
584 sock_update_classid(sk
);
586 /* Under a page? Don't bother with paged skb. */
587 if (prepad
+ len
< PAGE_SIZE
|| !linear
)
590 skb
= sock_alloc_send_pskb(sk
, prepad
+ linear
, len
- linear
, noblock
,
595 skb_reserve(skb
, prepad
);
596 skb_put(skb
, linear
);
597 skb
->data_len
= len
- linear
;
598 skb
->len
+= len
- linear
;
603 /* Get packet from user space buffer */
604 static ssize_t
tun_get_user(struct tun_struct
*tun
,
605 const struct iovec
*iv
, size_t count
,
608 struct tun_pi pi
= { 0, cpu_to_be16(ETH_P_IP
) };
610 size_t len
= count
, align
= NET_SKB_PAD
;
611 struct virtio_net_hdr gso
= { 0 };
614 if (!(tun
->flags
& TUN_NO_PI
)) {
615 if ((len
-= sizeof(pi
)) > count
)
618 if (memcpy_fromiovecend((void *)&pi
, iv
, 0, sizeof(pi
)))
620 offset
+= sizeof(pi
);
623 if (tun
->flags
& TUN_VNET_HDR
) {
624 if ((len
-= tun
->vnet_hdr_sz
) > count
)
627 if (memcpy_fromiovecend((void *)&gso
, iv
, offset
, sizeof(gso
)))
630 if ((gso
.flags
& VIRTIO_NET_HDR_F_NEEDS_CSUM
) &&
631 gso
.csum_start
+ gso
.csum_offset
+ 2 > gso
.hdr_len
)
632 gso
.hdr_len
= gso
.csum_start
+ gso
.csum_offset
+ 2;
634 if (gso
.hdr_len
> len
)
636 offset
+= tun
->vnet_hdr_sz
;
639 if ((tun
->flags
& TUN_TYPE_MASK
) == TUN_TAP_DEV
) {
640 align
+= NET_IP_ALIGN
;
641 if (unlikely(len
< ETH_HLEN
||
642 (gso
.hdr_len
&& gso
.hdr_len
< ETH_HLEN
)))
646 skb
= tun_alloc_skb(tun
, align
, len
, gso
.hdr_len
, noblock
);
648 if (PTR_ERR(skb
) != -EAGAIN
)
649 tun
->dev
->stats
.rx_dropped
++;
653 if (skb_copy_datagram_from_iovec(skb
, 0, iv
, offset
, len
)) {
654 tun
->dev
->stats
.rx_dropped
++;
659 if (gso
.flags
& VIRTIO_NET_HDR_F_NEEDS_CSUM
) {
660 if (!skb_partial_csum_set(skb
, gso
.csum_start
,
662 tun
->dev
->stats
.rx_frame_errors
++;
668 switch (tun
->flags
& TUN_TYPE_MASK
) {
670 if (tun
->flags
& TUN_NO_PI
) {
671 switch (skb
->data
[0] & 0xf0) {
673 pi
.proto
= htons(ETH_P_IP
);
676 pi
.proto
= htons(ETH_P_IPV6
);
679 tun
->dev
->stats
.rx_dropped
++;
685 skb_reset_mac_header(skb
);
686 skb
->protocol
= pi
.proto
;
690 skb
->protocol
= eth_type_trans(skb
, tun
->dev
);
694 if (gso
.gso_type
!= VIRTIO_NET_HDR_GSO_NONE
) {
696 switch (gso
.gso_type
& ~VIRTIO_NET_HDR_GSO_ECN
) {
697 case VIRTIO_NET_HDR_GSO_TCPV4
:
698 skb_shinfo(skb
)->gso_type
= SKB_GSO_TCPV4
;
700 case VIRTIO_NET_HDR_GSO_TCPV6
:
701 skb_shinfo(skb
)->gso_type
= SKB_GSO_TCPV6
;
703 case VIRTIO_NET_HDR_GSO_UDP
:
704 skb_shinfo(skb
)->gso_type
= SKB_GSO_UDP
;
707 tun
->dev
->stats
.rx_frame_errors
++;
712 if (gso
.gso_type
& VIRTIO_NET_HDR_GSO_ECN
)
713 skb_shinfo(skb
)->gso_type
|= SKB_GSO_TCP_ECN
;
715 skb_shinfo(skb
)->gso_size
= gso
.gso_size
;
716 if (skb_shinfo(skb
)->gso_size
== 0) {
717 tun
->dev
->stats
.rx_frame_errors
++;
722 /* Header must be checked, and gso_segs computed. */
723 skb_shinfo(skb
)->gso_type
|= SKB_GSO_DODGY
;
724 skb_shinfo(skb
)->gso_segs
= 0;
729 tun
->dev
->stats
.rx_packets
++;
730 tun
->dev
->stats
.rx_bytes
+= len
;
735 static ssize_t
tun_chr_aio_write(struct kiocb
*iocb
, const struct iovec
*iv
,
736 unsigned long count
, loff_t pos
)
738 struct file
*file
= iocb
->ki_filp
;
739 struct tun_struct
*tun
= tun_get(file
);
745 tun_debug(KERN_INFO
, tun
, "tun_chr_write %ld\n", count
);
747 result
= tun_get_user(tun
, iv
, iov_length(iv
, count
),
748 file
->f_flags
& O_NONBLOCK
);
754 /* Put packet to the user space buffer */
755 static ssize_t
tun_put_user(struct tun_struct
*tun
,
757 const struct iovec
*iv
, int len
)
759 struct tun_pi pi
= { 0, skb
->protocol
};
762 if (!(tun
->flags
& TUN_NO_PI
)) {
763 if ((len
-= sizeof(pi
)) < 0)
766 if (len
< skb
->len
) {
767 /* Packet will be striped */
768 pi
.flags
|= TUN_PKT_STRIP
;
771 if (memcpy_toiovecend(iv
, (void *) &pi
, 0, sizeof(pi
)))
776 if (tun
->flags
& TUN_VNET_HDR
) {
777 struct virtio_net_hdr gso
= { 0 }; /* no info leak */
778 if ((len
-= tun
->vnet_hdr_sz
) < 0)
781 if (skb_is_gso(skb
)) {
782 struct skb_shared_info
*sinfo
= skb_shinfo(skb
);
784 /* This is a hint as to how much should be linear. */
785 gso
.hdr_len
= skb_headlen(skb
);
786 gso
.gso_size
= sinfo
->gso_size
;
787 if (sinfo
->gso_type
& SKB_GSO_TCPV4
)
788 gso
.gso_type
= VIRTIO_NET_HDR_GSO_TCPV4
;
789 else if (sinfo
->gso_type
& SKB_GSO_TCPV6
)
790 gso
.gso_type
= VIRTIO_NET_HDR_GSO_TCPV6
;
791 else if (sinfo
->gso_type
& SKB_GSO_UDP
)
792 gso
.gso_type
= VIRTIO_NET_HDR_GSO_UDP
;
794 pr_err("unexpected GSO type: "
795 "0x%x, gso_size %d, hdr_len %d\n",
796 sinfo
->gso_type
, gso
.gso_size
,
798 print_hex_dump(KERN_ERR
, "tun: ",
801 min((int)gso
.hdr_len
, 64), true);
805 if (sinfo
->gso_type
& SKB_GSO_TCP_ECN
)
806 gso
.gso_type
|= VIRTIO_NET_HDR_GSO_ECN
;
808 gso
.gso_type
= VIRTIO_NET_HDR_GSO_NONE
;
810 if (skb
->ip_summed
== CHECKSUM_PARTIAL
) {
811 gso
.flags
= VIRTIO_NET_HDR_F_NEEDS_CSUM
;
812 gso
.csum_start
= skb_checksum_start_offset(skb
);
813 gso
.csum_offset
= skb
->csum_offset
;
814 } else if (skb
->ip_summed
== CHECKSUM_UNNECESSARY
) {
815 gso
.flags
= VIRTIO_NET_HDR_F_DATA_VALID
;
816 } /* else everything is zero */
818 if (unlikely(memcpy_toiovecend(iv
, (void *)&gso
, total
,
821 total
+= tun
->vnet_hdr_sz
;
824 len
= min_t(int, skb
->len
, len
);
826 skb_copy_datagram_const_iovec(skb
, 0, iv
, total
, len
);
829 tun
->dev
->stats
.tx_packets
++;
830 tun
->dev
->stats
.tx_bytes
+= len
;
835 static ssize_t
tun_do_read(struct tun_struct
*tun
,
836 struct kiocb
*iocb
, const struct iovec
*iv
,
837 ssize_t len
, int noblock
)
839 DECLARE_WAITQUEUE(wait
, current
);
843 tun_debug(KERN_INFO
, tun
, "tun_chr_read\n");
845 if (unlikely(!noblock
))
846 add_wait_queue(&tun
->wq
.wait
, &wait
);
848 current
->state
= TASK_INTERRUPTIBLE
;
850 /* Read frames from the queue */
851 if (!(skb
=skb_dequeue(&tun
->socket
.sk
->sk_receive_queue
))) {
856 if (signal_pending(current
)) {
860 if (tun
->dev
->reg_state
!= NETREG_REGISTERED
) {
865 /* Nothing to read, let's sleep */
869 netif_wake_queue(tun
->dev
);
871 ret
= tun_put_user(tun
, skb
, iv
, len
);
876 current
->state
= TASK_RUNNING
;
877 if (unlikely(!noblock
))
878 remove_wait_queue(&tun
->wq
.wait
, &wait
);
883 static ssize_t
tun_chr_aio_read(struct kiocb
*iocb
, const struct iovec
*iv
,
884 unsigned long count
, loff_t pos
)
886 struct file
*file
= iocb
->ki_filp
;
887 struct tun_file
*tfile
= file
->private_data
;
888 struct tun_struct
*tun
= __tun_get(tfile
);
893 len
= iov_length(iv
, count
);
899 ret
= tun_do_read(tun
, iocb
, iv
, len
, file
->f_flags
& O_NONBLOCK
);
900 ret
= min_t(ssize_t
, ret
, len
);
906 static void tun_setup(struct net_device
*dev
)
908 struct tun_struct
*tun
= netdev_priv(dev
);
913 dev
->ethtool_ops
= &tun_ethtool_ops
;
914 dev
->destructor
= tun_free_netdev
;
917 /* Trivial set of netlink ops to allow deleting tun or tap
918 * device with netlink.
920 static int tun_validate(struct nlattr
*tb
[], struct nlattr
*data
[])
925 static struct rtnl_link_ops tun_link_ops __read_mostly
= {
927 .priv_size
= sizeof(struct tun_struct
),
929 .validate
= tun_validate
,
932 static void tun_sock_write_space(struct sock
*sk
)
934 struct tun_struct
*tun
;
935 wait_queue_head_t
*wqueue
;
937 if (!sock_writeable(sk
))
940 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
))
943 wqueue
= sk_sleep(sk
);
944 if (wqueue
&& waitqueue_active(wqueue
))
945 wake_up_interruptible_sync_poll(wqueue
, POLLOUT
|
946 POLLWRNORM
| POLLWRBAND
);
948 tun
= tun_sk(sk
)->tun
;
949 kill_fasync(&tun
->fasync
, SIGIO
, POLL_OUT
);
952 static void tun_sock_destruct(struct sock
*sk
)
954 free_netdev(tun_sk(sk
)->tun
->dev
);
957 static int tun_sendmsg(struct kiocb
*iocb
, struct socket
*sock
,
958 struct msghdr
*m
, size_t total_len
)
960 struct tun_struct
*tun
= container_of(sock
, struct tun_struct
, socket
);
961 return tun_get_user(tun
, m
->msg_iov
, total_len
,
962 m
->msg_flags
& MSG_DONTWAIT
);
965 static int tun_recvmsg(struct kiocb
*iocb
, struct socket
*sock
,
966 struct msghdr
*m
, size_t total_len
,
969 struct tun_struct
*tun
= container_of(sock
, struct tun_struct
, socket
);
971 if (flags
& ~(MSG_DONTWAIT
|MSG_TRUNC
))
973 ret
= tun_do_read(tun
, iocb
, m
->msg_iov
, total_len
,
974 flags
& MSG_DONTWAIT
);
975 if (ret
> total_len
) {
976 m
->msg_flags
|= MSG_TRUNC
;
977 ret
= flags
& MSG_TRUNC
? ret
: total_len
;
982 /* Ops structure to mimic raw sockets with tun */
983 static const struct proto_ops tun_socket_ops
= {
984 .sendmsg
= tun_sendmsg
,
985 .recvmsg
= tun_recvmsg
,
988 static struct proto tun_proto
= {
990 .owner
= THIS_MODULE
,
991 .obj_size
= sizeof(struct tun_sock
),
994 static int tun_flags(struct tun_struct
*tun
)
998 if (tun
->flags
& TUN_TUN_DEV
)
1003 if (tun
->flags
& TUN_NO_PI
)
1006 if (tun
->flags
& TUN_ONE_QUEUE
)
1007 flags
|= IFF_ONE_QUEUE
;
1009 if (tun
->flags
& TUN_VNET_HDR
)
1010 flags
|= IFF_VNET_HDR
;
1015 static ssize_t
tun_show_flags(struct device
*dev
, struct device_attribute
*attr
,
1018 struct tun_struct
*tun
= netdev_priv(to_net_dev(dev
));
1019 return sprintf(buf
, "0x%x\n", tun_flags(tun
));
1022 static ssize_t
tun_show_owner(struct device
*dev
, struct device_attribute
*attr
,
1025 struct tun_struct
*tun
= netdev_priv(to_net_dev(dev
));
1026 return sprintf(buf
, "%d\n", tun
->owner
);
1029 static ssize_t
tun_show_group(struct device
*dev
, struct device_attribute
*attr
,
1032 struct tun_struct
*tun
= netdev_priv(to_net_dev(dev
));
1033 return sprintf(buf
, "%d\n", tun
->group
);
1036 static DEVICE_ATTR(tun_flags
, 0444, tun_show_flags
, NULL
);
1037 static DEVICE_ATTR(owner
, 0444, tun_show_owner
, NULL
);
1038 static DEVICE_ATTR(group
, 0444, tun_show_group
, NULL
);
1040 static int tun_set_iff(struct net
*net
, struct file
*file
, struct ifreq
*ifr
)
1043 struct tun_struct
*tun
;
1044 struct net_device
*dev
;
1047 dev
= __dev_get_by_name(net
, ifr
->ifr_name
);
1049 const struct cred
*cred
= current_cred();
1051 if (ifr
->ifr_flags
& IFF_TUN_EXCL
)
1053 if ((ifr
->ifr_flags
& IFF_TUN
) && dev
->netdev_ops
== &tun_netdev_ops
)
1054 tun
= netdev_priv(dev
);
1055 else if ((ifr
->ifr_flags
& IFF_TAP
) && dev
->netdev_ops
== &tap_netdev_ops
)
1056 tun
= netdev_priv(dev
);
1060 if (((tun
->owner
!= -1 && cred
->euid
!= tun
->owner
) ||
1061 (tun
->group
!= -1 && !in_egroup_p(tun
->group
))) &&
1062 !capable(CAP_NET_ADMIN
))
1064 err
= security_tun_dev_attach(tun
->socket
.sk
);
1068 err
= tun_attach(tun
, file
);
1074 unsigned long flags
= 0;
1076 if (!capable(CAP_NET_ADMIN
))
1078 err
= security_tun_dev_create();
1083 if (ifr
->ifr_flags
& IFF_TUN
) {
1085 flags
|= TUN_TUN_DEV
;
1087 } else if (ifr
->ifr_flags
& IFF_TAP
) {
1089 flags
|= TUN_TAP_DEV
;
1095 name
= ifr
->ifr_name
;
1097 dev
= alloc_netdev(sizeof(struct tun_struct
), name
,
1102 dev_net_set(dev
, net
);
1103 dev
->rtnl_link_ops
= &tun_link_ops
;
1105 tun
= netdev_priv(dev
);
1108 tun
->txflt
.count
= 0;
1109 tun
->vnet_hdr_sz
= sizeof(struct virtio_net_hdr
);
1112 sk
= sk_alloc(net
, AF_UNSPEC
, GFP_KERNEL
, &tun_proto
);
1116 tun
->socket
.wq
= &tun
->wq
;
1117 init_waitqueue_head(&tun
->wq
.wait
);
1118 tun
->socket
.ops
= &tun_socket_ops
;
1119 sock_init_data(&tun
->socket
, sk
);
1120 sk
->sk_write_space
= tun_sock_write_space
;
1121 sk
->sk_sndbuf
= INT_MAX
;
1123 tun_sk(sk
)->tun
= tun
;
1125 security_tun_dev_post_create(sk
);
1129 dev
->hw_features
= NETIF_F_SG
| NETIF_F_FRAGLIST
|
1131 dev
->features
= dev
->hw_features
;
1133 err
= register_netdevice(tun
->dev
);
1137 if (device_create_file(&tun
->dev
->dev
, &dev_attr_tun_flags
) ||
1138 device_create_file(&tun
->dev
->dev
, &dev_attr_owner
) ||
1139 device_create_file(&tun
->dev
->dev
, &dev_attr_group
))
1140 pr_err("Failed to create tun sysfs files\n");
1142 sk
->sk_destruct
= tun_sock_destruct
;
1144 err
= tun_attach(tun
, file
);
1149 tun_debug(KERN_INFO
, tun
, "tun_set_iff\n");
1151 if (ifr
->ifr_flags
& IFF_NO_PI
)
1152 tun
->flags
|= TUN_NO_PI
;
1154 tun
->flags
&= ~TUN_NO_PI
;
1156 if (ifr
->ifr_flags
& IFF_ONE_QUEUE
)
1157 tun
->flags
|= TUN_ONE_QUEUE
;
1159 tun
->flags
&= ~TUN_ONE_QUEUE
;
1161 if (ifr
->ifr_flags
& IFF_VNET_HDR
)
1162 tun
->flags
|= TUN_VNET_HDR
;
1164 tun
->flags
&= ~TUN_VNET_HDR
;
1166 /* Make sure persistent devices do not get stuck in
1169 if (netif_running(tun
->dev
))
1170 netif_wake_queue(tun
->dev
);
1172 strcpy(ifr
->ifr_name
, tun
->dev
->name
);
1183 static int tun_get_iff(struct net
*net
, struct tun_struct
*tun
,
1186 tun_debug(KERN_INFO
, tun
, "tun_get_iff\n");
1188 strcpy(ifr
->ifr_name
, tun
->dev
->name
);
1190 ifr
->ifr_flags
= tun_flags(tun
);
1195 /* This is like a cut-down ethtool ops, except done via tun fd so no
1196 * privs required. */
1197 static int set_offload(struct tun_struct
*tun
, unsigned long arg
)
1201 if (arg
& TUN_F_CSUM
) {
1202 features
|= NETIF_F_HW_CSUM
;
1205 if (arg
& (TUN_F_TSO4
|TUN_F_TSO6
)) {
1206 if (arg
& TUN_F_TSO_ECN
) {
1207 features
|= NETIF_F_TSO_ECN
;
1208 arg
&= ~TUN_F_TSO_ECN
;
1210 if (arg
& TUN_F_TSO4
)
1211 features
|= NETIF_F_TSO
;
1212 if (arg
& TUN_F_TSO6
)
1213 features
|= NETIF_F_TSO6
;
1214 arg
&= ~(TUN_F_TSO4
|TUN_F_TSO6
);
1217 if (arg
& TUN_F_UFO
) {
1218 features
|= NETIF_F_UFO
;
1223 /* This gives the user a way to test for new features in future by
1224 * trying to set them. */
1228 tun
->set_features
= features
;
1229 netdev_update_features(tun
->dev
);
1234 static long __tun_chr_ioctl(struct file
*file
, unsigned int cmd
,
1235 unsigned long arg
, int ifreq_len
)
1237 struct tun_file
*tfile
= file
->private_data
;
1238 struct tun_struct
*tun
;
1239 void __user
* argp
= (void __user
*)arg
;
1240 struct sock_fprog fprog
;
1246 if (cmd
== TUNSETIFF
|| _IOC_TYPE(cmd
) == 0x89)
1247 if (copy_from_user(&ifr
, argp
, ifreq_len
))
1250 if (cmd
== TUNGETFEATURES
) {
1251 /* Currently this just means: "what IFF flags are valid?".
1252 * This is needed because we never checked for invalid flags on
1254 return put_user(IFF_TUN
| IFF_TAP
| IFF_NO_PI
| IFF_ONE_QUEUE
|
1256 (unsigned int __user
*)argp
);
1261 tun
= __tun_get(tfile
);
1262 if (cmd
== TUNSETIFF
&& !tun
) {
1263 ifr
.ifr_name
[IFNAMSIZ
-1] = '\0';
1265 ret
= tun_set_iff(tfile
->net
, file
, &ifr
);
1270 if (copy_to_user(argp
, &ifr
, ifreq_len
))
1279 tun_debug(KERN_INFO
, tun
, "tun_chr_ioctl cmd %d\n", cmd
);
1284 ret
= tun_get_iff(current
->nsproxy
->net_ns
, tun
, &ifr
);
1288 if (copy_to_user(argp
, &ifr
, ifreq_len
))
1293 /* Disable/Enable checksum */
1295 /* [unimplemented] */
1296 tun_debug(KERN_INFO
, tun
, "ignored: set checksum %s\n",
1297 arg
? "disabled" : "enabled");
1301 /* Disable/Enable persist mode */
1303 tun
->flags
|= TUN_PERSIST
;
1305 tun
->flags
&= ~TUN_PERSIST
;
1307 tun_debug(KERN_INFO
, tun
, "persist %s\n",
1308 arg
? "enabled" : "disabled");
1312 /* Set owner of the device */
1313 tun
->owner
= (uid_t
) arg
;
1315 tun_debug(KERN_INFO
, tun
, "owner set to %d\n", tun
->owner
);
1319 /* Set group of the device */
1320 tun
->group
= (gid_t
) arg
;
1322 tun_debug(KERN_INFO
, tun
, "group set to %d\n", tun
->group
);
1326 /* Only allow setting the type when the interface is down */
1327 if (tun
->dev
->flags
& IFF_UP
) {
1328 tun_debug(KERN_INFO
, tun
,
1329 "Linktype set failed because interface is up\n");
1332 tun
->dev
->type
= (int) arg
;
1333 tun_debug(KERN_INFO
, tun
, "linktype set to %d\n",
1345 ret
= set_offload(tun
, arg
);
1348 case TUNSETTXFILTER
:
1349 /* Can be set only for TAPs */
1351 if ((tun
->flags
& TUN_TYPE_MASK
) != TUN_TAP_DEV
)
1353 ret
= update_filter(&tun
->txflt
, (void __user
*)arg
);
1357 /* Get hw address */
1358 memcpy(ifr
.ifr_hwaddr
.sa_data
, tun
->dev
->dev_addr
, ETH_ALEN
);
1359 ifr
.ifr_hwaddr
.sa_family
= tun
->dev
->type
;
1360 if (copy_to_user(argp
, &ifr
, ifreq_len
))
1365 /* Set hw address */
1366 tun_debug(KERN_DEBUG
, tun
, "set hw address: %pM\n",
1367 ifr
.ifr_hwaddr
.sa_data
);
1369 ret
= dev_set_mac_address(tun
->dev
, &ifr
.ifr_hwaddr
);
1373 sndbuf
= tun
->socket
.sk
->sk_sndbuf
;
1374 if (copy_to_user(argp
, &sndbuf
, sizeof(sndbuf
)))
1379 if (copy_from_user(&sndbuf
, argp
, sizeof(sndbuf
))) {
1384 tun
->socket
.sk
->sk_sndbuf
= sndbuf
;
1387 case TUNGETVNETHDRSZ
:
1388 vnet_hdr_sz
= tun
->vnet_hdr_sz
;
1389 if (copy_to_user(argp
, &vnet_hdr_sz
, sizeof(vnet_hdr_sz
)))
1393 case TUNSETVNETHDRSZ
:
1394 if (copy_from_user(&vnet_hdr_sz
, argp
, sizeof(vnet_hdr_sz
))) {
1398 if (vnet_hdr_sz
< (int)sizeof(struct virtio_net_hdr
)) {
1403 tun
->vnet_hdr_sz
= vnet_hdr_sz
;
1406 case TUNATTACHFILTER
:
1407 /* Can be set only for TAPs */
1409 if ((tun
->flags
& TUN_TYPE_MASK
) != TUN_TAP_DEV
)
1412 if (copy_from_user(&fprog
, argp
, sizeof(fprog
)))
1415 ret
= sk_attach_filter(&fprog
, tun
->socket
.sk
);
1418 case TUNDETACHFILTER
:
1419 /* Can be set only for TAPs */
1421 if ((tun
->flags
& TUN_TYPE_MASK
) != TUN_TAP_DEV
)
1423 ret
= sk_detach_filter(tun
->socket
.sk
);
1438 static long tun_chr_ioctl(struct file
*file
,
1439 unsigned int cmd
, unsigned long arg
)
1441 return __tun_chr_ioctl(file
, cmd
, arg
, sizeof (struct ifreq
));
1444 #ifdef CONFIG_COMPAT
1445 static long tun_chr_compat_ioctl(struct file
*file
,
1446 unsigned int cmd
, unsigned long arg
)
1451 case TUNSETTXFILTER
:
1456 arg
= (unsigned long)compat_ptr(arg
);
1459 arg
= (compat_ulong_t
)arg
;
1464 * compat_ifreq is shorter than ifreq, so we must not access beyond
1465 * the end of that structure. All fields that are used in this
1466 * driver are compatible though, we don't need to convert the
1469 return __tun_chr_ioctl(file
, cmd
, arg
, sizeof(struct compat_ifreq
));
1471 #endif /* CONFIG_COMPAT */
1473 static int tun_chr_fasync(int fd
, struct file
*file
, int on
)
1475 struct tun_struct
*tun
= tun_get(file
);
1481 tun_debug(KERN_INFO
, tun
, "tun_chr_fasync %d\n", on
);
1483 if ((ret
= fasync_helper(fd
, file
, on
, &tun
->fasync
)) < 0)
1487 ret
= __f_setown(file
, task_pid(current
), PIDTYPE_PID
, 0);
1490 tun
->flags
|= TUN_FASYNC
;
1492 tun
->flags
&= ~TUN_FASYNC
;
1499 static int tun_chr_open(struct inode
*inode
, struct file
* file
)
1501 struct tun_file
*tfile
;
1503 DBG1(KERN_INFO
, "tunX: tun_chr_open\n");
1505 tfile
= kmalloc(sizeof(*tfile
), GFP_KERNEL
);
1508 atomic_set(&tfile
->count
, 0);
1510 tfile
->net
= get_net(current
->nsproxy
->net_ns
);
1511 file
->private_data
= tfile
;
1515 static int tun_chr_close(struct inode
*inode
, struct file
*file
)
1517 struct tun_file
*tfile
= file
->private_data
;
1518 struct tun_struct
*tun
;
1520 tun
= __tun_get(tfile
);
1522 struct net_device
*dev
= tun
->dev
;
1524 tun_debug(KERN_INFO
, tun
, "tun_chr_close\n");
1528 /* If desirable, unregister the netdevice. */
1529 if (!(tun
->flags
& TUN_PERSIST
)) {
1531 if (dev
->reg_state
== NETREG_REGISTERED
)
1532 unregister_netdevice(dev
);
1539 sock_put(tun
->socket
.sk
);
1541 put_net(tfile
->net
);
1547 static const struct file_operations tun_fops
= {
1548 .owner
= THIS_MODULE
,
1549 .llseek
= no_llseek
,
1550 .read
= do_sync_read
,
1551 .aio_read
= tun_chr_aio_read
,
1552 .write
= do_sync_write
,
1553 .aio_write
= tun_chr_aio_write
,
1554 .poll
= tun_chr_poll
,
1555 .unlocked_ioctl
= tun_chr_ioctl
,
1556 #ifdef CONFIG_COMPAT
1557 .compat_ioctl
= tun_chr_compat_ioctl
,
1559 .open
= tun_chr_open
,
1560 .release
= tun_chr_close
,
1561 .fasync
= tun_chr_fasync
1564 static struct miscdevice tun_miscdev
= {
1567 .nodename
= "net/tun",
1571 /* ethtool interface */
1573 static int tun_get_settings(struct net_device
*dev
, struct ethtool_cmd
*cmd
)
1576 cmd
->advertising
= 0;
1577 ethtool_cmd_speed_set(cmd
, SPEED_10
);
1578 cmd
->duplex
= DUPLEX_FULL
;
1579 cmd
->port
= PORT_TP
;
1580 cmd
->phy_address
= 0;
1581 cmd
->transceiver
= XCVR_INTERNAL
;
1582 cmd
->autoneg
= AUTONEG_DISABLE
;
1588 static void tun_get_drvinfo(struct net_device
*dev
, struct ethtool_drvinfo
*info
)
1590 struct tun_struct
*tun
= netdev_priv(dev
);
1592 strcpy(info
->driver
, DRV_NAME
);
1593 strcpy(info
->version
, DRV_VERSION
);
1594 strcpy(info
->fw_version
, "N/A");
1596 switch (tun
->flags
& TUN_TYPE_MASK
) {
1598 strcpy(info
->bus_info
, "tun");
1601 strcpy(info
->bus_info
, "tap");
1606 static u32
tun_get_msglevel(struct net_device
*dev
)
1609 struct tun_struct
*tun
= netdev_priv(dev
);
1616 static void tun_set_msglevel(struct net_device
*dev
, u32 value
)
1619 struct tun_struct
*tun
= netdev_priv(dev
);
1624 static const struct ethtool_ops tun_ethtool_ops
= {
1625 .get_settings
= tun_get_settings
,
1626 .get_drvinfo
= tun_get_drvinfo
,
1627 .get_msglevel
= tun_get_msglevel
,
1628 .set_msglevel
= tun_set_msglevel
,
1629 .get_link
= ethtool_op_get_link
,
1633 static int __init
tun_init(void)
1637 pr_info("%s, %s\n", DRV_DESCRIPTION
, DRV_VERSION
);
1638 pr_info("%s\n", DRV_COPYRIGHT
);
1640 ret
= rtnl_link_register(&tun_link_ops
);
1642 pr_err("Can't register link_ops\n");
1646 ret
= misc_register(&tun_miscdev
);
1648 pr_err("Can't register misc device %d\n", TUN_MINOR
);
1653 rtnl_link_unregister(&tun_link_ops
);
1658 static void tun_cleanup(void)
1660 misc_deregister(&tun_miscdev
);
1661 rtnl_link_unregister(&tun_link_ops
);
1664 /* Get an underlying socket object from tun file. Returns error unless file is
1665 * attached to a device. The returned object works like a packet socket, it
1666 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
1667 * holding a reference to the file for as long as the socket is in use. */
1668 struct socket
*tun_get_socket(struct file
*file
)
1670 struct tun_struct
*tun
;
1671 if (file
->f_op
!= &tun_fops
)
1672 return ERR_PTR(-EINVAL
);
1673 tun
= tun_get(file
);
1675 return ERR_PTR(-EBADFD
);
1677 return &tun
->socket
;
1679 EXPORT_SYMBOL_GPL(tun_get_socket
);
1681 module_init(tun_init
);
1682 module_exit(tun_cleanup
);
1683 MODULE_DESCRIPTION(DRV_DESCRIPTION
);
1684 MODULE_AUTHOR(DRV_COPYRIGHT
);
1685 MODULE_LICENSE("GPL");
1686 MODULE_ALIAS_MISCDEV(TUN_MINOR
);
1687 MODULE_ALIAS("devname:net/tun");