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 eth_random_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/uaccess.h>
74 /* Uncomment to enable debugging */
75 /* #define TUN_DEBUG 1 */
80 #define tun_debug(level, tun, fmt, args...) \
83 netdev_printk(level, tun->dev, fmt, ##args); \
85 #define DBG1(level, fmt, args...) \
88 printk(level fmt, ##args); \
91 #define tun_debug(level, tun, fmt, args...) \
94 netdev_printk(level, tun->dev, fmt, ##args); \
96 #define DBG1(level, fmt, args...) \
99 printk(level fmt, ##args); \
103 #define GOODCOPY_LEN 128
105 #define FLT_EXACT_COUNT 8
107 unsigned int count
; /* Number of addrs. Zero means disabled */
108 u32 mask
[2]; /* Mask of the hashed addrs */
109 unsigned char addr
[FLT_EXACT_COUNT
][ETH_ALEN
];
112 /* 1024 is probably a high enough limit: modern hypervisors seem to support on
113 * the order of 100-200 CPUs so this leaves us some breathing space if we want
114 * to match a queue per guest CPU.
116 #define MAX_TAP_QUEUES 1024
118 #define TUN_FLOW_EXPIRE (3 * HZ)
120 /* A tun_file connects an open character device to a tuntap netdevice. It
121 * also contains all socket related strctures (except sock_fprog and tap_filter)
122 * to serve as one transmit queue for tuntap device. The sock_fprog and
123 * tap_filter were kept in tun_struct since they were used for filtering for the
124 * netdevice not for a specific queue (at least I didn't see the requirement for
128 * The tun_file and tun_struct are loosely coupled, the pointer from one to the
129 * other can only be read while rcu_read_lock or rtnl_lock is held.
133 struct socket socket
;
135 struct tun_struct __rcu
*tun
;
137 struct fasync_struct
*fasync
;
138 /* only used for fasnyc */
143 struct tun_flow_entry
{
144 struct hlist_node hash_link
;
146 struct tun_struct
*tun
;
150 unsigned long updated
;
153 #define TUN_NUM_FLOW_ENTRIES 1024
155 /* Since the socket were moved to tun_file, to preserve the behavior of persist
156 * device, socket filter, sndbuf and vnet header size were restore when the
157 * file were attached to a persist device.
160 struct tun_file __rcu
*tfiles
[MAX_TAP_QUEUES
];
161 unsigned int numqueues
;
166 struct net_device
*dev
;
167 netdev_features_t set_features
;
168 #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \
169 NETIF_F_TSO6|NETIF_F_UFO)
173 struct tap_filter txflt
;
174 struct sock_fprog fprog
;
175 /* protected by rtnl lock */
176 bool filter_attached
;
181 struct kmem_cache
*flow_cache
;
182 struct hlist_head flows
[TUN_NUM_FLOW_ENTRIES
];
183 struct timer_list flow_gc_timer
;
184 unsigned long ageing_time
;
187 static inline u32
tun_hashfn(u32 rxhash
)
189 return rxhash
& 0x3ff;
192 static struct tun_flow_entry
*tun_flow_find(struct hlist_head
*head
, u32 rxhash
)
194 struct tun_flow_entry
*e
;
195 struct hlist_node
*n
;
197 hlist_for_each_entry_rcu(e
, n
, head
, hash_link
) {
198 if (e
->rxhash
== rxhash
)
204 static struct tun_flow_entry
*tun_flow_create(struct tun_struct
*tun
,
205 struct hlist_head
*head
,
206 u32 rxhash
, u16 queue_index
)
208 struct tun_flow_entry
*e
= kmem_cache_alloc(tun
->flow_cache
,
211 tun_debug(KERN_INFO
, tun
, "create flow: hash %u index %u\n",
212 rxhash
, queue_index
);
213 e
->updated
= jiffies
;
215 e
->queue_index
= queue_index
;
217 hlist_add_head_rcu(&e
->hash_link
, head
);
222 static void tun_flow_free(struct rcu_head
*head
)
224 struct tun_flow_entry
*e
225 = container_of(head
, struct tun_flow_entry
, rcu
);
226 kmem_cache_free(e
->tun
->flow_cache
, e
);
229 static void tun_flow_delete(struct tun_struct
*tun
, struct tun_flow_entry
*e
)
231 tun_debug(KERN_INFO
, tun
, "delete flow: hash %u index %u\n",
232 e
->rxhash
, e
->queue_index
);
233 hlist_del_rcu(&e
->hash_link
);
234 call_rcu(&e
->rcu
, tun_flow_free
);
237 static void tun_flow_flush(struct tun_struct
*tun
)
241 spin_lock_bh(&tun
->lock
);
242 for (i
= 0; i
< TUN_NUM_FLOW_ENTRIES
; i
++) {
243 struct tun_flow_entry
*e
;
244 struct hlist_node
*h
, *n
;
246 hlist_for_each_entry_safe(e
, h
, n
, &tun
->flows
[i
], hash_link
)
247 tun_flow_delete(tun
, e
);
249 spin_unlock_bh(&tun
->lock
);
252 static void tun_flow_delete_by_queue(struct tun_struct
*tun
, u16 queue_index
)
256 spin_lock_bh(&tun
->lock
);
257 for (i
= 0; i
< TUN_NUM_FLOW_ENTRIES
; i
++) {
258 struct tun_flow_entry
*e
;
259 struct hlist_node
*h
, *n
;
261 hlist_for_each_entry_safe(e
, h
, n
, &tun
->flows
[i
], hash_link
) {
262 if (e
->queue_index
== queue_index
)
263 tun_flow_delete(tun
, e
);
266 spin_unlock_bh(&tun
->lock
);
269 static void tun_flow_cleanup(unsigned long data
)
271 struct tun_struct
*tun
= (struct tun_struct
*)data
;
272 unsigned long delay
= tun
->ageing_time
;
273 unsigned long next_timer
= jiffies
+ delay
;
274 unsigned long count
= 0;
277 tun_debug(KERN_INFO
, tun
, "tun_flow_cleanup\n");
279 spin_lock_bh(&tun
->lock
);
280 for (i
= 0; i
< TUN_NUM_FLOW_ENTRIES
; i
++) {
281 struct tun_flow_entry
*e
;
282 struct hlist_node
*h
, *n
;
284 hlist_for_each_entry_safe(e
, h
, n
, &tun
->flows
[i
], hash_link
) {
285 unsigned long this_timer
;
287 this_timer
= e
->updated
+ delay
;
288 if (time_before_eq(this_timer
, jiffies
))
289 tun_flow_delete(tun
, e
);
290 else if (time_before(this_timer
, next_timer
))
291 next_timer
= this_timer
;
296 mod_timer(&tun
->flow_gc_timer
, round_jiffies_up(next_timer
));
297 spin_unlock_bh(&tun
->lock
);
300 static void tun_flow_update(struct tun_struct
*tun
, u32 rxhash
,
303 struct hlist_head
*head
;
304 struct tun_flow_entry
*e
;
305 unsigned long delay
= tun
->ageing_time
;
310 head
= &tun
->flows
[tun_hashfn(rxhash
)];
314 if (tun
->numqueues
== 1)
317 e
= tun_flow_find(head
, rxhash
);
319 /* TODO: keep queueing to old queue until it's empty? */
320 e
->queue_index
= queue_index
;
321 e
->updated
= jiffies
;
323 spin_lock_bh(&tun
->lock
);
324 if (!tun_flow_find(head
, rxhash
))
325 tun_flow_create(tun
, head
, rxhash
, queue_index
);
327 if (!timer_pending(&tun
->flow_gc_timer
))
328 mod_timer(&tun
->flow_gc_timer
,
329 round_jiffies_up(jiffies
+ delay
));
330 spin_unlock_bh(&tun
->lock
);
337 /* We try to identify a flow through its rxhash first. The reason that
338 * we do not check rxq no. is becuase some cards(e.g 82599), chooses
339 * the rxq based on the txq where the last packet of the flow comes. As
340 * the userspace application move between processors, we may get a
341 * different rxq no. here. If we could not get rxhash, then we would
342 * hope the rxq no. may help here.
344 static u16
tun_select_queue(struct net_device
*dev
, struct sk_buff
*skb
)
346 struct tun_struct
*tun
= netdev_priv(dev
);
347 struct tun_flow_entry
*e
;
352 numqueues
= tun
->numqueues
;
354 txq
= skb_get_rxhash(skb
);
356 e
= tun_flow_find(&tun
->flows
[tun_hashfn(txq
)], txq
);
358 txq
= e
->queue_index
;
360 /* use multiply and shift instead of expensive divide */
361 txq
= ((u64
)txq
* numqueues
) >> 32;
362 } else if (likely(skb_rx_queue_recorded(skb
))) {
363 txq
= skb_get_rx_queue(skb
);
364 while (unlikely(txq
>= numqueues
))
372 static inline bool tun_not_capable(struct tun_struct
*tun
)
374 const struct cred
*cred
= current_cred();
375 struct net
*net
= dev_net(tun
->dev
);
377 return ((uid_valid(tun
->owner
) && !uid_eq(cred
->euid
, tun
->owner
)) ||
378 (gid_valid(tun
->group
) && !in_egroup_p(tun
->group
))) &&
379 !ns_capable(net
->user_ns
, CAP_NET_ADMIN
);
382 static void tun_set_real_num_queues(struct tun_struct
*tun
)
384 netif_set_real_num_tx_queues(tun
->dev
, tun
->numqueues
);
385 netif_set_real_num_rx_queues(tun
->dev
, tun
->numqueues
);
388 static void __tun_detach(struct tun_file
*tfile
, bool clean
)
390 struct tun_file
*ntfile
;
391 struct tun_struct
*tun
;
392 struct net_device
*dev
;
394 tun
= rcu_dereference_protected(tfile
->tun
,
395 lockdep_rtnl_is_held());
397 u16 index
= tfile
->queue_index
;
398 BUG_ON(index
>= tun
->numqueues
);
401 rcu_assign_pointer(tun
->tfiles
[index
],
402 tun
->tfiles
[tun
->numqueues
- 1]);
403 rcu_assign_pointer(tfile
->tun
, NULL
);
404 ntfile
= rcu_dereference_protected(tun
->tfiles
[index
],
405 lockdep_rtnl_is_held());
406 ntfile
->queue_index
= index
;
409 sock_put(&tfile
->sk
);
412 tun_flow_delete_by_queue(tun
, tun
->numqueues
+ 1);
413 /* Drop read queue */
414 skb_queue_purge(&tfile
->sk
.sk_receive_queue
);
415 tun_set_real_num_queues(tun
);
417 if (tun
->numqueues
== 0 && !(tun
->flags
& TUN_PERSIST
))
418 if (dev
->reg_state
== NETREG_REGISTERED
)
419 unregister_netdevice(dev
);
423 BUG_ON(!test_bit(SOCK_EXTERNALLY_ALLOCATED
,
424 &tfile
->socket
.flags
));
425 sk_release_kernel(&tfile
->sk
);
429 static void tun_detach(struct tun_file
*tfile
, bool clean
)
432 __tun_detach(tfile
, clean
);
436 static void tun_detach_all(struct net_device
*dev
)
438 struct tun_struct
*tun
= netdev_priv(dev
);
439 struct tun_file
*tfile
;
440 int i
, n
= tun
->numqueues
;
442 for (i
= 0; i
< n
; i
++) {
443 tfile
= rcu_dereference_protected(tun
->tfiles
[i
],
444 lockdep_rtnl_is_held());
446 wake_up_all(&tfile
->wq
.wait
);
447 rcu_assign_pointer(tfile
->tun
, NULL
);
450 BUG_ON(tun
->numqueues
!= 0);
453 for (i
= 0; i
< n
; i
++) {
454 tfile
= rcu_dereference_protected(tun
->tfiles
[i
],
455 lockdep_rtnl_is_held());
456 /* Drop read queue */
457 skb_queue_purge(&tfile
->sk
.sk_receive_queue
);
458 sock_put(&tfile
->sk
);
462 static int tun_attach(struct tun_struct
*tun
, struct file
*file
)
464 struct tun_file
*tfile
= file
->private_data
;
468 if (rcu_dereference_protected(tfile
->tun
, lockdep_rtnl_is_held()))
472 if (!(tun
->flags
& TUN_TAP_MQ
) && tun
->numqueues
== 1)
476 if (tun
->numqueues
== MAX_TAP_QUEUES
)
481 /* Re-attach the filter to presist device */
482 if (tun
->filter_attached
== true) {
483 err
= sk_attach_filter(&tun
->fprog
, tfile
->socket
.sk
);
487 tfile
->queue_index
= tun
->numqueues
;
488 rcu_assign_pointer(tfile
->tun
, tun
);
489 rcu_assign_pointer(tun
->tfiles
[tun
->numqueues
], tfile
);
490 sock_hold(&tfile
->sk
);
493 tun_set_real_num_queues(tun
);
495 /* device is allowed to go away first, so no need to hold extra
503 static struct tun_struct
*__tun_get(struct tun_file
*tfile
)
505 struct tun_struct
*tun
;
508 tun
= rcu_dereference(tfile
->tun
);
516 static struct tun_struct
*tun_get(struct file
*file
)
518 return __tun_get(file
->private_data
);
521 static void tun_put(struct tun_struct
*tun
)
527 static void addr_hash_set(u32
*mask
, const u8
*addr
)
529 int n
= ether_crc(ETH_ALEN
, addr
) >> 26;
530 mask
[n
>> 5] |= (1 << (n
& 31));
533 static unsigned int addr_hash_test(const u32
*mask
, const u8
*addr
)
535 int n
= ether_crc(ETH_ALEN
, addr
) >> 26;
536 return mask
[n
>> 5] & (1 << (n
& 31));
539 static int update_filter(struct tap_filter
*filter
, void __user
*arg
)
541 struct { u8 u
[ETH_ALEN
]; } *addr
;
542 struct tun_filter uf
;
543 int err
, alen
, n
, nexact
;
545 if (copy_from_user(&uf
, arg
, sizeof(uf
)))
554 alen
= ETH_ALEN
* uf
.count
;
555 addr
= kmalloc(alen
, GFP_KERNEL
);
559 if (copy_from_user(addr
, arg
+ sizeof(uf
), alen
)) {
564 /* The filter is updated without holding any locks. Which is
565 * perfectly safe. We disable it first and in the worst
566 * case we'll accept a few undesired packets. */
570 /* Use first set of addresses as an exact filter */
571 for (n
= 0; n
< uf
.count
&& n
< FLT_EXACT_COUNT
; n
++)
572 memcpy(filter
->addr
[n
], addr
[n
].u
, ETH_ALEN
);
576 /* Remaining multicast addresses are hashed,
577 * unicast will leave the filter disabled. */
578 memset(filter
->mask
, 0, sizeof(filter
->mask
));
579 for (; n
< uf
.count
; n
++) {
580 if (!is_multicast_ether_addr(addr
[n
].u
)) {
581 err
= 0; /* no filter */
584 addr_hash_set(filter
->mask
, addr
[n
].u
);
587 /* For ALLMULTI just set the mask to all ones.
588 * This overrides the mask populated above. */
589 if ((uf
.flags
& TUN_FLT_ALLMULTI
))
590 memset(filter
->mask
, ~0, sizeof(filter
->mask
));
592 /* Now enable the filter */
594 filter
->count
= nexact
;
596 /* Return the number of exact filters */
604 /* Returns: 0 - drop, !=0 - accept */
605 static int run_filter(struct tap_filter
*filter
, const struct sk_buff
*skb
)
607 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
609 struct ethhdr
*eh
= (struct ethhdr
*) skb
->data
;
613 for (i
= 0; i
< filter
->count
; i
++)
614 if (ether_addr_equal(eh
->h_dest
, filter
->addr
[i
]))
617 /* Inexact match (multicast only) */
618 if (is_multicast_ether_addr(eh
->h_dest
))
619 return addr_hash_test(filter
->mask
, eh
->h_dest
);
625 * Checks whether the packet is accepted or not.
626 * Returns: 0 - drop, !=0 - accept
628 static int check_filter(struct tap_filter
*filter
, const struct sk_buff
*skb
)
633 return run_filter(filter
, skb
);
636 /* Network device part of the driver */
638 static const struct ethtool_ops tun_ethtool_ops
;
640 /* Net device detach from fd. */
641 static void tun_net_uninit(struct net_device
*dev
)
646 /* Net device open. */
647 static int tun_net_open(struct net_device
*dev
)
649 netif_tx_start_all_queues(dev
);
653 /* Net device close. */
654 static int tun_net_close(struct net_device
*dev
)
656 netif_tx_stop_all_queues(dev
);
660 /* Net device start xmit */
661 static netdev_tx_t
tun_net_xmit(struct sk_buff
*skb
, struct net_device
*dev
)
663 struct tun_struct
*tun
= netdev_priv(dev
);
664 int txq
= skb
->queue_mapping
;
665 struct tun_file
*tfile
;
668 tfile
= rcu_dereference(tun
->tfiles
[txq
]);
670 /* Drop packet if interface is not attached */
671 if (txq
>= tun
->numqueues
)
674 tun_debug(KERN_INFO
, tun
, "tun_net_xmit %d\n", skb
->len
);
678 /* Drop if the filter does not like it.
679 * This is a noop if the filter is disabled.
680 * Filter can be enabled only for the TAP devices. */
681 if (!check_filter(&tun
->txflt
, skb
))
684 if (tfile
->socket
.sk
->sk_filter
&&
685 sk_filter(tfile
->socket
.sk
, skb
))
688 /* Limit the number of packets queued by dividing txq length with the
691 if (skb_queue_len(&tfile
->socket
.sk
->sk_receive_queue
)
692 >= dev
->tx_queue_len
/ tun
->numqueues
)
695 /* Orphan the skb - required as we might hang on to it
696 * for indefinite time. */
697 if (unlikely(skb_orphan_frags(skb
, GFP_ATOMIC
)))
702 skb_queue_tail(&tfile
->socket
.sk
->sk_receive_queue
, skb
);
704 /* Notify and wake up reader process */
705 if (tfile
->flags
& TUN_FASYNC
)
706 kill_fasync(&tfile
->fasync
, SIGIO
, POLL_IN
);
707 wake_up_interruptible_poll(&tfile
->wq
.wait
, POLLIN
|
708 POLLRDNORM
| POLLRDBAND
);
714 dev
->stats
.tx_dropped
++;
721 static void tun_net_mclist(struct net_device
*dev
)
724 * This callback is supposed to deal with mc filter in
725 * _rx_ path and has nothing to do with the _tx_ path.
726 * In rx path we always accept everything userspace gives us.
731 #define MAX_MTU 65535
734 tun_net_change_mtu(struct net_device
*dev
, int new_mtu
)
736 if (new_mtu
< MIN_MTU
|| new_mtu
+ dev
->hard_header_len
> MAX_MTU
)
742 static netdev_features_t
tun_net_fix_features(struct net_device
*dev
,
743 netdev_features_t features
)
745 struct tun_struct
*tun
= netdev_priv(dev
);
747 return (features
& tun
->set_features
) | (features
& ~TUN_USER_FEATURES
);
749 #ifdef CONFIG_NET_POLL_CONTROLLER
750 static void tun_poll_controller(struct net_device
*dev
)
753 * Tun only receives frames when:
754 * 1) the char device endpoint gets data from user space
755 * 2) the tun socket gets a sendmsg call from user space
756 * Since both of those are syncronous operations, we are guaranteed
757 * never to have pending data when we poll for it
758 * so theres nothing to do here but return.
759 * We need this though so netpoll recognizes us as an interface that
760 * supports polling, which enables bridge devices in virt setups to
761 * still use netconsole
766 static const struct net_device_ops tun_netdev_ops
= {
767 .ndo_uninit
= tun_net_uninit
,
768 .ndo_open
= tun_net_open
,
769 .ndo_stop
= tun_net_close
,
770 .ndo_start_xmit
= tun_net_xmit
,
771 .ndo_change_mtu
= tun_net_change_mtu
,
772 .ndo_fix_features
= tun_net_fix_features
,
773 .ndo_select_queue
= tun_select_queue
,
774 #ifdef CONFIG_NET_POLL_CONTROLLER
775 .ndo_poll_controller
= tun_poll_controller
,
779 static const struct net_device_ops tap_netdev_ops
= {
780 .ndo_uninit
= tun_net_uninit
,
781 .ndo_open
= tun_net_open
,
782 .ndo_stop
= tun_net_close
,
783 .ndo_start_xmit
= tun_net_xmit
,
784 .ndo_change_mtu
= tun_net_change_mtu
,
785 .ndo_fix_features
= tun_net_fix_features
,
786 .ndo_set_rx_mode
= tun_net_mclist
,
787 .ndo_set_mac_address
= eth_mac_addr
,
788 .ndo_validate_addr
= eth_validate_addr
,
789 .ndo_select_queue
= tun_select_queue
,
790 #ifdef CONFIG_NET_POLL_CONTROLLER
791 .ndo_poll_controller
= tun_poll_controller
,
795 static int tun_flow_init(struct tun_struct
*tun
)
799 tun
->flow_cache
= kmem_cache_create("tun_flow_cache",
800 sizeof(struct tun_flow_entry
), 0, 0,
802 if (!tun
->flow_cache
)
805 for (i
= 0; i
< TUN_NUM_FLOW_ENTRIES
; i
++)
806 INIT_HLIST_HEAD(&tun
->flows
[i
]);
808 tun
->ageing_time
= TUN_FLOW_EXPIRE
;
809 setup_timer(&tun
->flow_gc_timer
, tun_flow_cleanup
, (unsigned long)tun
);
810 mod_timer(&tun
->flow_gc_timer
,
811 round_jiffies_up(jiffies
+ tun
->ageing_time
));
816 static void tun_flow_uninit(struct tun_struct
*tun
)
818 del_timer_sync(&tun
->flow_gc_timer
);
821 /* Wait for completion of call_rcu()'s */
823 kmem_cache_destroy(tun
->flow_cache
);
826 /* Initialize net device. */
827 static void tun_net_init(struct net_device
*dev
)
829 struct tun_struct
*tun
= netdev_priv(dev
);
831 switch (tun
->flags
& TUN_TYPE_MASK
) {
833 dev
->netdev_ops
= &tun_netdev_ops
;
835 /* Point-to-Point TUN Device */
836 dev
->hard_header_len
= 0;
840 /* Zero header length */
841 dev
->type
= ARPHRD_NONE
;
842 dev
->flags
= IFF_POINTOPOINT
| IFF_NOARP
| IFF_MULTICAST
;
843 dev
->tx_queue_len
= TUN_READQ_SIZE
; /* We prefer our own queue length */
847 dev
->netdev_ops
= &tap_netdev_ops
;
848 /* Ethernet TAP Device */
850 dev
->priv_flags
&= ~IFF_TX_SKB_SHARING
;
851 dev
->priv_flags
|= IFF_LIVE_ADDR_CHANGE
;
853 eth_hw_addr_random(dev
);
855 dev
->tx_queue_len
= TUN_READQ_SIZE
; /* We prefer our own queue length */
860 /* Character device part */
863 static unsigned int tun_chr_poll(struct file
*file
, poll_table
*wait
)
865 struct tun_file
*tfile
= file
->private_data
;
866 struct tun_struct
*tun
= __tun_get(tfile
);
868 unsigned int mask
= 0;
873 sk
= tfile
->socket
.sk
;
875 tun_debug(KERN_INFO
, tun
, "tun_chr_poll\n");
877 poll_wait(file
, &tfile
->wq
.wait
, wait
);
879 if (!skb_queue_empty(&sk
->sk_receive_queue
))
880 mask
|= POLLIN
| POLLRDNORM
;
882 if (sock_writeable(sk
) ||
883 (!test_and_set_bit(SOCK_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
) &&
885 mask
|= POLLOUT
| POLLWRNORM
;
887 if (tun
->dev
->reg_state
!= NETREG_REGISTERED
)
894 /* prepad is the amount to reserve at front. len is length after that.
895 * linear is a hint as to how much to copy (usually headers). */
896 static struct sk_buff
*tun_alloc_skb(struct tun_file
*tfile
,
897 size_t prepad
, size_t len
,
898 size_t linear
, int noblock
)
900 struct sock
*sk
= tfile
->socket
.sk
;
904 /* Under a page? Don't bother with paged skb. */
905 if (prepad
+ len
< PAGE_SIZE
|| !linear
)
908 skb
= sock_alloc_send_pskb(sk
, prepad
+ linear
, len
- linear
, noblock
,
913 skb_reserve(skb
, prepad
);
914 skb_put(skb
, linear
);
915 skb
->data_len
= len
- linear
;
916 skb
->len
+= len
- linear
;
921 /* set skb frags from iovec, this can move to core network code for reuse */
922 static int zerocopy_sg_from_iovec(struct sk_buff
*skb
, const struct iovec
*from
,
923 int offset
, size_t count
)
925 int len
= iov_length(from
, count
) - offset
;
926 int copy
= skb_headlen(skb
);
927 int size
, offset1
= 0;
930 /* Skip over from offset */
931 while (count
&& (offset
>= from
->iov_len
)) {
932 offset
-= from
->iov_len
;
937 /* copy up to skb headlen */
938 while (count
&& (copy
> 0)) {
939 size
= min_t(unsigned int, copy
, from
->iov_len
- offset
);
940 if (copy_from_user(skb
->data
+ offset1
, from
->iov_base
+ offset
,
957 struct page
*page
[MAX_SKB_FRAGS
];
960 unsigned long truesize
;
962 len
= from
->iov_len
- offset
;
968 base
= (unsigned long)from
->iov_base
+ offset
;
969 size
= ((base
& ~PAGE_MASK
) + len
+ ~PAGE_MASK
) >> PAGE_SHIFT
;
970 if (i
+ size
> MAX_SKB_FRAGS
)
972 num_pages
= get_user_pages_fast(base
, size
, 0, &page
[i
]);
973 if (num_pages
!= size
) {
974 for (i
= 0; i
< num_pages
; i
++)
978 truesize
= size
* PAGE_SIZE
;
979 skb
->data_len
+= len
;
981 skb
->truesize
+= truesize
;
982 atomic_add(truesize
, &skb
->sk
->sk_wmem_alloc
);
984 int off
= base
& ~PAGE_MASK
;
985 int size
= min_t(int, len
, PAGE_SIZE
- off
);
986 __skb_fill_page_desc(skb
, i
, page
[i
], off
, size
);
987 skb_shinfo(skb
)->nr_frags
++;
988 /* increase sk_wmem_alloc */
999 /* Get packet from user space buffer */
1000 static ssize_t
tun_get_user(struct tun_struct
*tun
, struct tun_file
*tfile
,
1001 void *msg_control
, const struct iovec
*iv
,
1002 size_t total_len
, size_t count
, int noblock
)
1004 struct tun_pi pi
= { 0, cpu_to_be16(ETH_P_IP
) };
1005 struct sk_buff
*skb
;
1006 size_t len
= total_len
, align
= NET_SKB_PAD
;
1007 struct virtio_net_hdr gso
= { 0 };
1010 bool zerocopy
= false;
1014 if (!(tun
->flags
& TUN_NO_PI
)) {
1015 if ((len
-= sizeof(pi
)) > total_len
)
1018 if (memcpy_fromiovecend((void *)&pi
, iv
, 0, sizeof(pi
)))
1020 offset
+= sizeof(pi
);
1023 if (tun
->flags
& TUN_VNET_HDR
) {
1024 if ((len
-= tun
->vnet_hdr_sz
) > total_len
)
1027 if (memcpy_fromiovecend((void *)&gso
, iv
, offset
, sizeof(gso
)))
1030 if ((gso
.flags
& VIRTIO_NET_HDR_F_NEEDS_CSUM
) &&
1031 gso
.csum_start
+ gso
.csum_offset
+ 2 > gso
.hdr_len
)
1032 gso
.hdr_len
= gso
.csum_start
+ gso
.csum_offset
+ 2;
1034 if (gso
.hdr_len
> len
)
1036 offset
+= tun
->vnet_hdr_sz
;
1039 if ((tun
->flags
& TUN_TYPE_MASK
) == TUN_TAP_DEV
) {
1040 align
+= NET_IP_ALIGN
;
1041 if (unlikely(len
< ETH_HLEN
||
1042 (gso
.hdr_len
&& gso
.hdr_len
< ETH_HLEN
)))
1050 /* Userspace may produce vectors with count greater than
1051 * MAX_SKB_FRAGS, so we need to linearize parts of the skb
1052 * to let the rest of data to be fit in the frags.
1054 if (count
> MAX_SKB_FRAGS
) {
1055 copylen
= iov_length(iv
, count
- MAX_SKB_FRAGS
);
1056 if (copylen
< offset
)
1062 /* There are 256 bytes to be copied in skb, so there is enough
1063 * room for skb expand head in case it is used.
1064 * The rest of the buffer is mapped from userspace.
1066 if (copylen
< gso
.hdr_len
)
1067 copylen
= gso
.hdr_len
;
1069 copylen
= GOODCOPY_LEN
;
1073 skb
= tun_alloc_skb(tfile
, align
, copylen
, gso
.hdr_len
, noblock
);
1075 if (PTR_ERR(skb
) != -EAGAIN
)
1076 tun
->dev
->stats
.rx_dropped
++;
1077 return PTR_ERR(skb
);
1081 err
= zerocopy_sg_from_iovec(skb
, iv
, offset
, count
);
1083 err
= skb_copy_datagram_from_iovec(skb
, 0, iv
, offset
, len
);
1086 tun
->dev
->stats
.rx_dropped
++;
1091 if (gso
.flags
& VIRTIO_NET_HDR_F_NEEDS_CSUM
) {
1092 if (!skb_partial_csum_set(skb
, gso
.csum_start
,
1094 tun
->dev
->stats
.rx_frame_errors
++;
1100 switch (tun
->flags
& TUN_TYPE_MASK
) {
1102 if (tun
->flags
& TUN_NO_PI
) {
1103 switch (skb
->data
[0] & 0xf0) {
1105 pi
.proto
= htons(ETH_P_IP
);
1108 pi
.proto
= htons(ETH_P_IPV6
);
1111 tun
->dev
->stats
.rx_dropped
++;
1117 skb_reset_mac_header(skb
);
1118 skb
->protocol
= pi
.proto
;
1119 skb
->dev
= tun
->dev
;
1122 skb
->protocol
= eth_type_trans(skb
, tun
->dev
);
1126 if (gso
.gso_type
!= VIRTIO_NET_HDR_GSO_NONE
) {
1128 switch (gso
.gso_type
& ~VIRTIO_NET_HDR_GSO_ECN
) {
1129 case VIRTIO_NET_HDR_GSO_TCPV4
:
1130 skb_shinfo(skb
)->gso_type
= SKB_GSO_TCPV4
;
1132 case VIRTIO_NET_HDR_GSO_TCPV6
:
1133 skb_shinfo(skb
)->gso_type
= SKB_GSO_TCPV6
;
1135 case VIRTIO_NET_HDR_GSO_UDP
:
1136 skb_shinfo(skb
)->gso_type
= SKB_GSO_UDP
;
1139 tun
->dev
->stats
.rx_frame_errors
++;
1144 if (gso
.gso_type
& VIRTIO_NET_HDR_GSO_ECN
)
1145 skb_shinfo(skb
)->gso_type
|= SKB_GSO_TCP_ECN
;
1147 skb_shinfo(skb
)->gso_size
= gso
.gso_size
;
1148 if (skb_shinfo(skb
)->gso_size
== 0) {
1149 tun
->dev
->stats
.rx_frame_errors
++;
1154 /* Header must be checked, and gso_segs computed. */
1155 skb_shinfo(skb
)->gso_type
|= SKB_GSO_DODGY
;
1156 skb_shinfo(skb
)->gso_segs
= 0;
1159 /* copy skb_ubuf_info for callback when skb has no error */
1161 skb_shinfo(skb
)->destructor_arg
= msg_control
;
1162 skb_shinfo(skb
)->tx_flags
|= SKBTX_DEV_ZEROCOPY
;
1165 rxhash
= skb_get_rxhash(skb
);
1168 tun
->dev
->stats
.rx_packets
++;
1169 tun
->dev
->stats
.rx_bytes
+= len
;
1171 tun_flow_update(tun
, rxhash
, tfile
->queue_index
);
1175 static ssize_t
tun_chr_aio_write(struct kiocb
*iocb
, const struct iovec
*iv
,
1176 unsigned long count
, loff_t pos
)
1178 struct file
*file
= iocb
->ki_filp
;
1179 struct tun_struct
*tun
= tun_get(file
);
1180 struct tun_file
*tfile
= file
->private_data
;
1186 tun_debug(KERN_INFO
, tun
, "tun_chr_write %ld\n", count
);
1188 result
= tun_get_user(tun
, tfile
, NULL
, iv
, iov_length(iv
, count
),
1189 count
, file
->f_flags
& O_NONBLOCK
);
1195 /* Put packet to the user space buffer */
1196 static ssize_t
tun_put_user(struct tun_struct
*tun
,
1197 struct tun_file
*tfile
,
1198 struct sk_buff
*skb
,
1199 const struct iovec
*iv
, int len
)
1201 struct tun_pi pi
= { 0, skb
->protocol
};
1204 if (!(tun
->flags
& TUN_NO_PI
)) {
1205 if ((len
-= sizeof(pi
)) < 0)
1208 if (len
< skb
->len
) {
1209 /* Packet will be striped */
1210 pi
.flags
|= TUN_PKT_STRIP
;
1213 if (memcpy_toiovecend(iv
, (void *) &pi
, 0, sizeof(pi
)))
1215 total
+= sizeof(pi
);
1218 if (tun
->flags
& TUN_VNET_HDR
) {
1219 struct virtio_net_hdr gso
= { 0 }; /* no info leak */
1220 if ((len
-= tun
->vnet_hdr_sz
) < 0)
1223 if (skb_is_gso(skb
)) {
1224 struct skb_shared_info
*sinfo
= skb_shinfo(skb
);
1226 /* This is a hint as to how much should be linear. */
1227 gso
.hdr_len
= skb_headlen(skb
);
1228 gso
.gso_size
= sinfo
->gso_size
;
1229 if (sinfo
->gso_type
& SKB_GSO_TCPV4
)
1230 gso
.gso_type
= VIRTIO_NET_HDR_GSO_TCPV4
;
1231 else if (sinfo
->gso_type
& SKB_GSO_TCPV6
)
1232 gso
.gso_type
= VIRTIO_NET_HDR_GSO_TCPV6
;
1233 else if (sinfo
->gso_type
& SKB_GSO_UDP
)
1234 gso
.gso_type
= VIRTIO_NET_HDR_GSO_UDP
;
1236 pr_err("unexpected GSO type: "
1237 "0x%x, gso_size %d, hdr_len %d\n",
1238 sinfo
->gso_type
, gso
.gso_size
,
1240 print_hex_dump(KERN_ERR
, "tun: ",
1243 min((int)gso
.hdr_len
, 64), true);
1247 if (sinfo
->gso_type
& SKB_GSO_TCP_ECN
)
1248 gso
.gso_type
|= VIRTIO_NET_HDR_GSO_ECN
;
1250 gso
.gso_type
= VIRTIO_NET_HDR_GSO_NONE
;
1252 if (skb
->ip_summed
== CHECKSUM_PARTIAL
) {
1253 gso
.flags
= VIRTIO_NET_HDR_F_NEEDS_CSUM
;
1254 gso
.csum_start
= skb_checksum_start_offset(skb
);
1255 gso
.csum_offset
= skb
->csum_offset
;
1256 } else if (skb
->ip_summed
== CHECKSUM_UNNECESSARY
) {
1257 gso
.flags
= VIRTIO_NET_HDR_F_DATA_VALID
;
1258 } /* else everything is zero */
1260 if (unlikely(memcpy_toiovecend(iv
, (void *)&gso
, total
,
1263 total
+= tun
->vnet_hdr_sz
;
1266 len
= min_t(int, skb
->len
, len
);
1268 skb_copy_datagram_const_iovec(skb
, 0, iv
, total
, len
);
1271 tun
->dev
->stats
.tx_packets
++;
1272 tun
->dev
->stats
.tx_bytes
+= len
;
1277 static ssize_t
tun_do_read(struct tun_struct
*tun
, struct tun_file
*tfile
,
1278 struct kiocb
*iocb
, const struct iovec
*iv
,
1279 ssize_t len
, int noblock
)
1281 DECLARE_WAITQUEUE(wait
, current
);
1282 struct sk_buff
*skb
;
1285 tun_debug(KERN_INFO
, tun
, "tun_do_read\n");
1287 if (unlikely(!noblock
))
1288 add_wait_queue(&tfile
->wq
.wait
, &wait
);
1290 current
->state
= TASK_INTERRUPTIBLE
;
1292 /* Read frames from the queue */
1293 if (!(skb
= skb_dequeue(&tfile
->socket
.sk
->sk_receive_queue
))) {
1298 if (signal_pending(current
)) {
1302 if (tun
->dev
->reg_state
!= NETREG_REGISTERED
) {
1307 /* Nothing to read, let's sleep */
1312 ret
= tun_put_user(tun
, tfile
, skb
, iv
, len
);
1317 current
->state
= TASK_RUNNING
;
1318 if (unlikely(!noblock
))
1319 remove_wait_queue(&tfile
->wq
.wait
, &wait
);
1324 static ssize_t
tun_chr_aio_read(struct kiocb
*iocb
, const struct iovec
*iv
,
1325 unsigned long count
, loff_t pos
)
1327 struct file
*file
= iocb
->ki_filp
;
1328 struct tun_file
*tfile
= file
->private_data
;
1329 struct tun_struct
*tun
= __tun_get(tfile
);
1334 len
= iov_length(iv
, count
);
1340 ret
= tun_do_read(tun
, tfile
, iocb
, iv
, len
,
1341 file
->f_flags
& O_NONBLOCK
);
1342 ret
= min_t(ssize_t
, ret
, len
);
1348 static void tun_free_netdev(struct net_device
*dev
)
1350 struct tun_struct
*tun
= netdev_priv(dev
);
1352 tun_flow_uninit(tun
);
1356 static void tun_setup(struct net_device
*dev
)
1358 struct tun_struct
*tun
= netdev_priv(dev
);
1360 tun
->owner
= INVALID_UID
;
1361 tun
->group
= INVALID_GID
;
1363 dev
->ethtool_ops
= &tun_ethtool_ops
;
1364 dev
->destructor
= tun_free_netdev
;
1367 /* Trivial set of netlink ops to allow deleting tun or tap
1368 * device with netlink.
1370 static int tun_validate(struct nlattr
*tb
[], struct nlattr
*data
[])
1375 static struct rtnl_link_ops tun_link_ops __read_mostly
= {
1377 .priv_size
= sizeof(struct tun_struct
),
1379 .validate
= tun_validate
,
1382 static void tun_sock_write_space(struct sock
*sk
)
1384 struct tun_file
*tfile
;
1385 wait_queue_head_t
*wqueue
;
1387 if (!sock_writeable(sk
))
1390 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
))
1393 wqueue
= sk_sleep(sk
);
1394 if (wqueue
&& waitqueue_active(wqueue
))
1395 wake_up_interruptible_sync_poll(wqueue
, POLLOUT
|
1396 POLLWRNORM
| POLLWRBAND
);
1398 tfile
= container_of(sk
, struct tun_file
, sk
);
1399 kill_fasync(&tfile
->fasync
, SIGIO
, POLL_OUT
);
1402 static int tun_sendmsg(struct kiocb
*iocb
, struct socket
*sock
,
1403 struct msghdr
*m
, size_t total_len
)
1406 struct tun_file
*tfile
= container_of(sock
, struct tun_file
, socket
);
1407 struct tun_struct
*tun
= __tun_get(tfile
);
1411 ret
= tun_get_user(tun
, tfile
, m
->msg_control
, m
->msg_iov
, total_len
,
1412 m
->msg_iovlen
, m
->msg_flags
& MSG_DONTWAIT
);
1418 static int tun_recvmsg(struct kiocb
*iocb
, struct socket
*sock
,
1419 struct msghdr
*m
, size_t total_len
,
1422 struct tun_file
*tfile
= container_of(sock
, struct tun_file
, socket
);
1423 struct tun_struct
*tun
= __tun_get(tfile
);
1429 if (flags
& ~(MSG_DONTWAIT
|MSG_TRUNC
))
1431 ret
= tun_do_read(tun
, tfile
, iocb
, m
->msg_iov
, total_len
,
1432 flags
& MSG_DONTWAIT
);
1433 if (ret
> total_len
) {
1434 m
->msg_flags
|= MSG_TRUNC
;
1435 ret
= flags
& MSG_TRUNC
? ret
: total_len
;
1441 static int tun_release(struct socket
*sock
)
1448 /* Ops structure to mimic raw sockets with tun */
1449 static const struct proto_ops tun_socket_ops
= {
1450 .sendmsg
= tun_sendmsg
,
1451 .recvmsg
= tun_recvmsg
,
1452 .release
= tun_release
,
1455 static struct proto tun_proto
= {
1457 .owner
= THIS_MODULE
,
1458 .obj_size
= sizeof(struct tun_file
),
1461 static int tun_flags(struct tun_struct
*tun
)
1465 if (tun
->flags
& TUN_TUN_DEV
)
1470 if (tun
->flags
& TUN_NO_PI
)
1473 /* This flag has no real effect. We track the value for backwards
1476 if (tun
->flags
& TUN_ONE_QUEUE
)
1477 flags
|= IFF_ONE_QUEUE
;
1479 if (tun
->flags
& TUN_VNET_HDR
)
1480 flags
|= IFF_VNET_HDR
;
1482 if (tun
->flags
& TUN_TAP_MQ
)
1483 flags
|= IFF_MULTI_QUEUE
;
1488 static ssize_t
tun_show_flags(struct device
*dev
, struct device_attribute
*attr
,
1491 struct tun_struct
*tun
= netdev_priv(to_net_dev(dev
));
1492 return sprintf(buf
, "0x%x\n", tun_flags(tun
));
1495 static ssize_t
tun_show_owner(struct device
*dev
, struct device_attribute
*attr
,
1498 struct tun_struct
*tun
= netdev_priv(to_net_dev(dev
));
1499 return uid_valid(tun
->owner
)?
1500 sprintf(buf
, "%u\n",
1501 from_kuid_munged(current_user_ns(), tun
->owner
)):
1502 sprintf(buf
, "-1\n");
1505 static ssize_t
tun_show_group(struct device
*dev
, struct device_attribute
*attr
,
1508 struct tun_struct
*tun
= netdev_priv(to_net_dev(dev
));
1509 return gid_valid(tun
->group
) ?
1510 sprintf(buf
, "%u\n",
1511 from_kgid_munged(current_user_ns(), tun
->group
)):
1512 sprintf(buf
, "-1\n");
1515 static DEVICE_ATTR(tun_flags
, 0444, tun_show_flags
, NULL
);
1516 static DEVICE_ATTR(owner
, 0444, tun_show_owner
, NULL
);
1517 static DEVICE_ATTR(group
, 0444, tun_show_group
, NULL
);
1519 static int tun_set_iff(struct net
*net
, struct file
*file
, struct ifreq
*ifr
)
1521 struct tun_struct
*tun
;
1522 struct tun_file
*tfile
= file
->private_data
;
1523 struct net_device
*dev
;
1526 dev
= __dev_get_by_name(net
, ifr
->ifr_name
);
1528 if (ifr
->ifr_flags
& IFF_TUN_EXCL
)
1530 if ((ifr
->ifr_flags
& IFF_TUN
) && dev
->netdev_ops
== &tun_netdev_ops
)
1531 tun
= netdev_priv(dev
);
1532 else if ((ifr
->ifr_flags
& IFF_TAP
) && dev
->netdev_ops
== &tap_netdev_ops
)
1533 tun
= netdev_priv(dev
);
1537 if (tun_not_capable(tun
))
1539 err
= security_tun_dev_attach(tfile
->socket
.sk
);
1543 err
= tun_attach(tun
, file
);
1549 unsigned long flags
= 0;
1551 if (!ns_capable(net
->user_ns
, CAP_NET_ADMIN
))
1553 err
= security_tun_dev_create();
1558 if (ifr
->ifr_flags
& IFF_TUN
) {
1560 flags
|= TUN_TUN_DEV
;
1562 } else if (ifr
->ifr_flags
& IFF_TAP
) {
1564 flags
|= TUN_TAP_DEV
;
1570 name
= ifr
->ifr_name
;
1572 dev
= alloc_netdev_mqs(sizeof(struct tun_struct
), name
,
1574 MAX_TAP_QUEUES
, MAX_TAP_QUEUES
);
1578 dev_net_set(dev
, net
);
1579 dev
->rtnl_link_ops
= &tun_link_ops
;
1581 tun
= netdev_priv(dev
);
1584 tun
->txflt
.count
= 0;
1585 tun
->vnet_hdr_sz
= sizeof(struct virtio_net_hdr
);
1587 tun
->filter_attached
= false;
1588 tun
->sndbuf
= tfile
->socket
.sk
->sk_sndbuf
;
1590 spin_lock_init(&tun
->lock
);
1592 security_tun_dev_post_create(&tfile
->sk
);
1596 err
= tun_flow_init(tun
);
1600 dev
->hw_features
= NETIF_F_SG
| NETIF_F_FRAGLIST
|
1602 dev
->features
= dev
->hw_features
;
1604 err
= tun_attach(tun
, file
);
1608 err
= register_netdevice(tun
->dev
);
1612 if (device_create_file(&tun
->dev
->dev
, &dev_attr_tun_flags
) ||
1613 device_create_file(&tun
->dev
->dev
, &dev_attr_owner
) ||
1614 device_create_file(&tun
->dev
->dev
, &dev_attr_group
))
1615 pr_err("Failed to create tun sysfs files\n");
1617 netif_carrier_on(tun
->dev
);
1620 tun_debug(KERN_INFO
, tun
, "tun_set_iff\n");
1622 if (ifr
->ifr_flags
& IFF_NO_PI
)
1623 tun
->flags
|= TUN_NO_PI
;
1625 tun
->flags
&= ~TUN_NO_PI
;
1627 /* This flag has no real effect. We track the value for backwards
1630 if (ifr
->ifr_flags
& IFF_ONE_QUEUE
)
1631 tun
->flags
|= TUN_ONE_QUEUE
;
1633 tun
->flags
&= ~TUN_ONE_QUEUE
;
1635 if (ifr
->ifr_flags
& IFF_VNET_HDR
)
1636 tun
->flags
|= TUN_VNET_HDR
;
1638 tun
->flags
&= ~TUN_VNET_HDR
;
1640 if (ifr
->ifr_flags
& IFF_MULTI_QUEUE
)
1641 tun
->flags
|= TUN_TAP_MQ
;
1643 tun
->flags
&= ~TUN_TAP_MQ
;
1645 /* Make sure persistent devices do not get stuck in
1648 if (netif_running(tun
->dev
))
1649 netif_tx_wake_all_queues(tun
->dev
);
1651 strcpy(ifr
->ifr_name
, tun
->dev
->name
);
1659 static void tun_get_iff(struct net
*net
, struct tun_struct
*tun
,
1662 tun_debug(KERN_INFO
, tun
, "tun_get_iff\n");
1664 strcpy(ifr
->ifr_name
, tun
->dev
->name
);
1666 ifr
->ifr_flags
= tun_flags(tun
);
1670 /* This is like a cut-down ethtool ops, except done via tun fd so no
1671 * privs required. */
1672 static int set_offload(struct tun_struct
*tun
, unsigned long arg
)
1674 netdev_features_t features
= 0;
1676 if (arg
& TUN_F_CSUM
) {
1677 features
|= NETIF_F_HW_CSUM
;
1680 if (arg
& (TUN_F_TSO4
|TUN_F_TSO6
)) {
1681 if (arg
& TUN_F_TSO_ECN
) {
1682 features
|= NETIF_F_TSO_ECN
;
1683 arg
&= ~TUN_F_TSO_ECN
;
1685 if (arg
& TUN_F_TSO4
)
1686 features
|= NETIF_F_TSO
;
1687 if (arg
& TUN_F_TSO6
)
1688 features
|= NETIF_F_TSO6
;
1689 arg
&= ~(TUN_F_TSO4
|TUN_F_TSO6
);
1692 if (arg
& TUN_F_UFO
) {
1693 features
|= NETIF_F_UFO
;
1698 /* This gives the user a way to test for new features in future by
1699 * trying to set them. */
1703 tun
->set_features
= features
;
1704 netdev_update_features(tun
->dev
);
1709 static void tun_detach_filter(struct tun_struct
*tun
, int n
)
1712 struct tun_file
*tfile
;
1714 for (i
= 0; i
< n
; i
++) {
1715 tfile
= rcu_dereference_protected(tun
->tfiles
[i
],
1716 lockdep_rtnl_is_held());
1717 sk_detach_filter(tfile
->socket
.sk
);
1720 tun
->filter_attached
= false;
1723 static int tun_attach_filter(struct tun_struct
*tun
)
1726 struct tun_file
*tfile
;
1728 for (i
= 0; i
< tun
->numqueues
; i
++) {
1729 tfile
= rcu_dereference_protected(tun
->tfiles
[i
],
1730 lockdep_rtnl_is_held());
1731 ret
= sk_attach_filter(&tun
->fprog
, tfile
->socket
.sk
);
1733 tun_detach_filter(tun
, i
);
1738 tun
->filter_attached
= true;
1742 static void tun_set_sndbuf(struct tun_struct
*tun
)
1744 struct tun_file
*tfile
;
1747 for (i
= 0; i
< tun
->numqueues
; i
++) {
1748 tfile
= rcu_dereference_protected(tun
->tfiles
[i
],
1749 lockdep_rtnl_is_held());
1750 tfile
->socket
.sk
->sk_sndbuf
= tun
->sndbuf
;
1754 static int tun_set_queue(struct file
*file
, struct ifreq
*ifr
)
1756 struct tun_file
*tfile
= file
->private_data
;
1757 struct tun_struct
*tun
;
1758 struct net_device
*dev
;
1763 if (ifr
->ifr_flags
& IFF_ATTACH_QUEUE
) {
1764 dev
= __dev_get_by_name(tfile
->net
, ifr
->ifr_name
);
1770 tun
= netdev_priv(dev
);
1771 if (dev
->netdev_ops
!= &tap_netdev_ops
&&
1772 dev
->netdev_ops
!= &tun_netdev_ops
)
1774 else if (tun_not_capable(tun
))
1777 ret
= tun_attach(tun
, file
);
1778 } else if (ifr
->ifr_flags
& IFF_DETACH_QUEUE
)
1779 __tun_detach(tfile
, false);
1788 static long __tun_chr_ioctl(struct file
*file
, unsigned int cmd
,
1789 unsigned long arg
, int ifreq_len
)
1791 struct tun_file
*tfile
= file
->private_data
;
1792 struct tun_struct
*tun
;
1793 void __user
* argp
= (void __user
*)arg
;
1801 if (cmd
== TUNSETIFF
|| cmd
== TUNSETQUEUE
|| _IOC_TYPE(cmd
) == 0x89) {
1802 if (copy_from_user(&ifr
, argp
, ifreq_len
))
1805 memset(&ifr
, 0, sizeof(ifr
));
1807 if (cmd
== TUNGETFEATURES
) {
1808 /* Currently this just means: "what IFF flags are valid?".
1809 * This is needed because we never checked for invalid flags on
1811 return put_user(IFF_TUN
| IFF_TAP
| IFF_NO_PI
| IFF_ONE_QUEUE
|
1812 IFF_VNET_HDR
| IFF_MULTI_QUEUE
,
1813 (unsigned int __user
*)argp
);
1814 } else if (cmd
== TUNSETQUEUE
)
1815 return tun_set_queue(file
, &ifr
);
1820 tun
= __tun_get(tfile
);
1821 if (cmd
== TUNSETIFF
&& !tun
) {
1822 ifr
.ifr_name
[IFNAMSIZ
-1] = '\0';
1824 ret
= tun_set_iff(tfile
->net
, file
, &ifr
);
1829 if (copy_to_user(argp
, &ifr
, ifreq_len
))
1838 tun_debug(KERN_INFO
, tun
, "tun_chr_ioctl cmd %u\n", cmd
);
1843 tun_get_iff(current
->nsproxy
->net_ns
, tun
, &ifr
);
1845 if (copy_to_user(argp
, &ifr
, ifreq_len
))
1850 /* Disable/Enable checksum */
1852 /* [unimplemented] */
1853 tun_debug(KERN_INFO
, tun
, "ignored: set checksum %s\n",
1854 arg
? "disabled" : "enabled");
1858 /* Disable/Enable persist mode. Keep an extra reference to the
1859 * module to prevent the module being unprobed.
1862 tun
->flags
|= TUN_PERSIST
;
1863 __module_get(THIS_MODULE
);
1865 tun
->flags
&= ~TUN_PERSIST
;
1866 module_put(THIS_MODULE
);
1869 tun_debug(KERN_INFO
, tun
, "persist %s\n",
1870 arg
? "enabled" : "disabled");
1874 /* Set owner of the device */
1875 owner
= make_kuid(current_user_ns(), arg
);
1876 if (!uid_valid(owner
)) {
1881 tun_debug(KERN_INFO
, tun
, "owner set to %u\n",
1882 from_kuid(&init_user_ns
, tun
->owner
));
1886 /* Set group of the device */
1887 group
= make_kgid(current_user_ns(), arg
);
1888 if (!gid_valid(group
)) {
1893 tun_debug(KERN_INFO
, tun
, "group set to %u\n",
1894 from_kgid(&init_user_ns
, tun
->group
));
1898 /* Only allow setting the type when the interface is down */
1899 if (tun
->dev
->flags
& IFF_UP
) {
1900 tun_debug(KERN_INFO
, tun
,
1901 "Linktype set failed because interface is up\n");
1904 tun
->dev
->type
= (int) arg
;
1905 tun_debug(KERN_INFO
, tun
, "linktype set to %d\n",
1917 ret
= set_offload(tun
, arg
);
1920 case TUNSETTXFILTER
:
1921 /* Can be set only for TAPs */
1923 if ((tun
->flags
& TUN_TYPE_MASK
) != TUN_TAP_DEV
)
1925 ret
= update_filter(&tun
->txflt
, (void __user
*)arg
);
1929 /* Get hw address */
1930 memcpy(ifr
.ifr_hwaddr
.sa_data
, tun
->dev
->dev_addr
, ETH_ALEN
);
1931 ifr
.ifr_hwaddr
.sa_family
= tun
->dev
->type
;
1932 if (copy_to_user(argp
, &ifr
, ifreq_len
))
1937 /* Set hw address */
1938 tun_debug(KERN_DEBUG
, tun
, "set hw address: %pM\n",
1939 ifr
.ifr_hwaddr
.sa_data
);
1941 ret
= dev_set_mac_address(tun
->dev
, &ifr
.ifr_hwaddr
);
1945 sndbuf
= tfile
->socket
.sk
->sk_sndbuf
;
1946 if (copy_to_user(argp
, &sndbuf
, sizeof(sndbuf
)))
1951 if (copy_from_user(&sndbuf
, argp
, sizeof(sndbuf
))) {
1956 tun
->sndbuf
= sndbuf
;
1957 tun_set_sndbuf(tun
);
1960 case TUNGETVNETHDRSZ
:
1961 vnet_hdr_sz
= tun
->vnet_hdr_sz
;
1962 if (copy_to_user(argp
, &vnet_hdr_sz
, sizeof(vnet_hdr_sz
)))
1966 case TUNSETVNETHDRSZ
:
1967 if (copy_from_user(&vnet_hdr_sz
, argp
, sizeof(vnet_hdr_sz
))) {
1971 if (vnet_hdr_sz
< (int)sizeof(struct virtio_net_hdr
)) {
1976 tun
->vnet_hdr_sz
= vnet_hdr_sz
;
1979 case TUNATTACHFILTER
:
1980 /* Can be set only for TAPs */
1982 if ((tun
->flags
& TUN_TYPE_MASK
) != TUN_TAP_DEV
)
1985 if (copy_from_user(&tun
->fprog
, argp
, sizeof(tun
->fprog
)))
1988 ret
= tun_attach_filter(tun
);
1991 case TUNDETACHFILTER
:
1992 /* Can be set only for TAPs */
1994 if ((tun
->flags
& TUN_TYPE_MASK
) != TUN_TAP_DEV
)
1997 tun_detach_filter(tun
, tun
->numqueues
);
2012 static long tun_chr_ioctl(struct file
*file
,
2013 unsigned int cmd
, unsigned long arg
)
2015 return __tun_chr_ioctl(file
, cmd
, arg
, sizeof (struct ifreq
));
2018 #ifdef CONFIG_COMPAT
2019 static long tun_chr_compat_ioctl(struct file
*file
,
2020 unsigned int cmd
, unsigned long arg
)
2025 case TUNSETTXFILTER
:
2030 arg
= (unsigned long)compat_ptr(arg
);
2033 arg
= (compat_ulong_t
)arg
;
2038 * compat_ifreq is shorter than ifreq, so we must not access beyond
2039 * the end of that structure. All fields that are used in this
2040 * driver are compatible though, we don't need to convert the
2043 return __tun_chr_ioctl(file
, cmd
, arg
, sizeof(struct compat_ifreq
));
2045 #endif /* CONFIG_COMPAT */
2047 static int tun_chr_fasync(int fd
, struct file
*file
, int on
)
2049 struct tun_file
*tfile
= file
->private_data
;
2052 if ((ret
= fasync_helper(fd
, file
, on
, &tfile
->fasync
)) < 0)
2056 ret
= __f_setown(file
, task_pid(current
), PIDTYPE_PID
, 0);
2059 tfile
->flags
|= TUN_FASYNC
;
2061 tfile
->flags
&= ~TUN_FASYNC
;
2067 static int tun_chr_open(struct inode
*inode
, struct file
* file
)
2069 struct tun_file
*tfile
;
2071 DBG1(KERN_INFO
, "tunX: tun_chr_open\n");
2073 tfile
= (struct tun_file
*)sk_alloc(&init_net
, AF_UNSPEC
, GFP_KERNEL
,
2077 rcu_assign_pointer(tfile
->tun
, NULL
);
2078 tfile
->net
= get_net(current
->nsproxy
->net_ns
);
2081 rcu_assign_pointer(tfile
->socket
.wq
, &tfile
->wq
);
2082 init_waitqueue_head(&tfile
->wq
.wait
);
2084 tfile
->socket
.file
= file
;
2085 tfile
->socket
.ops
= &tun_socket_ops
;
2087 sock_init_data(&tfile
->socket
, &tfile
->sk
);
2088 sk_change_net(&tfile
->sk
, tfile
->net
);
2090 tfile
->sk
.sk_write_space
= tun_sock_write_space
;
2091 tfile
->sk
.sk_sndbuf
= INT_MAX
;
2093 file
->private_data
= tfile
;
2094 set_bit(SOCK_EXTERNALLY_ALLOCATED
, &tfile
->socket
.flags
);
2099 static int tun_chr_close(struct inode
*inode
, struct file
*file
)
2101 struct tun_file
*tfile
= file
->private_data
;
2102 struct net
*net
= tfile
->net
;
2104 tun_detach(tfile
, true);
2110 static const struct file_operations tun_fops
= {
2111 .owner
= THIS_MODULE
,
2112 .llseek
= no_llseek
,
2113 .read
= do_sync_read
,
2114 .aio_read
= tun_chr_aio_read
,
2115 .write
= do_sync_write
,
2116 .aio_write
= tun_chr_aio_write
,
2117 .poll
= tun_chr_poll
,
2118 .unlocked_ioctl
= tun_chr_ioctl
,
2119 #ifdef CONFIG_COMPAT
2120 .compat_ioctl
= tun_chr_compat_ioctl
,
2122 .open
= tun_chr_open
,
2123 .release
= tun_chr_close
,
2124 .fasync
= tun_chr_fasync
2127 static struct miscdevice tun_miscdev
= {
2130 .nodename
= "net/tun",
2134 /* ethtool interface */
2136 static int tun_get_settings(struct net_device
*dev
, struct ethtool_cmd
*cmd
)
2139 cmd
->advertising
= 0;
2140 ethtool_cmd_speed_set(cmd
, SPEED_10
);
2141 cmd
->duplex
= DUPLEX_FULL
;
2142 cmd
->port
= PORT_TP
;
2143 cmd
->phy_address
= 0;
2144 cmd
->transceiver
= XCVR_INTERNAL
;
2145 cmd
->autoneg
= AUTONEG_DISABLE
;
2151 static void tun_get_drvinfo(struct net_device
*dev
, struct ethtool_drvinfo
*info
)
2153 struct tun_struct
*tun
= netdev_priv(dev
);
2155 strlcpy(info
->driver
, DRV_NAME
, sizeof(info
->driver
));
2156 strlcpy(info
->version
, DRV_VERSION
, sizeof(info
->version
));
2158 switch (tun
->flags
& TUN_TYPE_MASK
) {
2160 strlcpy(info
->bus_info
, "tun", sizeof(info
->bus_info
));
2163 strlcpy(info
->bus_info
, "tap", sizeof(info
->bus_info
));
2168 static u32
tun_get_msglevel(struct net_device
*dev
)
2171 struct tun_struct
*tun
= netdev_priv(dev
);
2178 static void tun_set_msglevel(struct net_device
*dev
, u32 value
)
2181 struct tun_struct
*tun
= netdev_priv(dev
);
2186 static const struct ethtool_ops tun_ethtool_ops
= {
2187 .get_settings
= tun_get_settings
,
2188 .get_drvinfo
= tun_get_drvinfo
,
2189 .get_msglevel
= tun_get_msglevel
,
2190 .set_msglevel
= tun_set_msglevel
,
2191 .get_link
= ethtool_op_get_link
,
2195 static int __init
tun_init(void)
2199 pr_info("%s, %s\n", DRV_DESCRIPTION
, DRV_VERSION
);
2200 pr_info("%s\n", DRV_COPYRIGHT
);
2202 ret
= rtnl_link_register(&tun_link_ops
);
2204 pr_err("Can't register link_ops\n");
2208 ret
= misc_register(&tun_miscdev
);
2210 pr_err("Can't register misc device %d\n", TUN_MINOR
);
2215 rtnl_link_unregister(&tun_link_ops
);
2220 static void tun_cleanup(void)
2222 misc_deregister(&tun_miscdev
);
2223 rtnl_link_unregister(&tun_link_ops
);
2226 /* Get an underlying socket object from tun file. Returns error unless file is
2227 * attached to a device. The returned object works like a packet socket, it
2228 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
2229 * holding a reference to the file for as long as the socket is in use. */
2230 struct socket
*tun_get_socket(struct file
*file
)
2232 struct tun_file
*tfile
;
2233 if (file
->f_op
!= &tun_fops
)
2234 return ERR_PTR(-EINVAL
);
2235 tfile
= file
->private_data
;
2237 return ERR_PTR(-EBADFD
);
2238 return &tfile
->socket
;
2240 EXPORT_SYMBOL_GPL(tun_get_socket
);
2242 module_init(tun_init
);
2243 module_exit(tun_cleanup
);
2244 MODULE_DESCRIPTION(DRV_DESCRIPTION
);
2245 MODULE_AUTHOR(DRV_COPYRIGHT
);
2246 MODULE_LICENSE("GPL");
2247 MODULE_ALIAS_MISCDEV(TUN_MINOR
);
2248 MODULE_ALIAS("devname:net/tun");