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/if_vlan.h>
64 #include <linux/crc32.h>
65 #include <linux/nsproxy.h>
66 #include <linux/virtio_net.h>
67 #include <linux/rcupdate.h>
68 #include <net/net_namespace.h>
69 #include <net/netns/generic.h>
70 #include <net/rtnetlink.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 GOODCOPY_LEN 128
106 #define FLT_EXACT_COUNT 8
108 unsigned int count
; /* Number of addrs. Zero means disabled */
109 u32 mask
[2]; /* Mask of the hashed addrs */
110 unsigned char addr
[FLT_EXACT_COUNT
][ETH_ALEN
];
113 /* DEFAULT_MAX_NUM_RSS_QUEUES were choosed to let the rx/tx queues allocated for
114 * the netdevice to be fit in one page. So we can make sure the success of
115 * memory allocation. TODO: increase the limit. */
116 #define MAX_TAP_QUEUES DEFAULT_MAX_NUM_RSS_QUEUES
117 #define MAX_TAP_FLOWS 4096
119 #define TUN_FLOW_EXPIRE (3 * HZ)
121 /* A tun_file connects an open character device to a tuntap netdevice. It
122 * also contains all socket related strctures (except sock_fprog and tap_filter)
123 * to serve as one transmit queue for tuntap device. The sock_fprog and
124 * tap_filter were kept in tun_struct since they were used for filtering for the
125 * netdevice not for a specific queue (at least I didn't see the requirement for
129 * The tun_file and tun_struct are loosely coupled, the pointer from one to the
130 * other can only be read while rcu_read_lock or rtnl_lock is held.
134 struct socket socket
;
136 struct tun_struct __rcu
*tun
;
138 struct fasync_struct
*fasync
;
139 /* only used for fasnyc */
142 struct list_head next
;
143 struct tun_struct
*detached
;
146 struct tun_flow_entry
{
147 struct hlist_node hash_link
;
149 struct tun_struct
*tun
;
153 unsigned long updated
;
156 #define TUN_NUM_FLOW_ENTRIES 1024
158 /* Since the socket were moved to tun_file, to preserve the behavior of persist
159 * device, socket filter, sndbuf and vnet header size were restore when the
160 * file were attached to a persist device.
163 struct tun_file __rcu
*tfiles
[MAX_TAP_QUEUES
];
164 unsigned int numqueues
;
169 struct net_device
*dev
;
170 netdev_features_t set_features
;
171 #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \
172 NETIF_F_TSO6|NETIF_F_UFO)
176 struct tap_filter txflt
;
177 struct sock_fprog fprog
;
178 /* protected by rtnl lock */
179 bool filter_attached
;
184 struct hlist_head flows
[TUN_NUM_FLOW_ENTRIES
];
185 struct timer_list flow_gc_timer
;
186 unsigned long ageing_time
;
187 unsigned int numdisabled
;
188 struct list_head disabled
;
193 static inline u32
tun_hashfn(u32 rxhash
)
195 return rxhash
& 0x3ff;
198 static struct tun_flow_entry
*tun_flow_find(struct hlist_head
*head
, u32 rxhash
)
200 struct tun_flow_entry
*e
;
202 hlist_for_each_entry_rcu(e
, head
, hash_link
) {
203 if (e
->rxhash
== rxhash
)
209 static struct tun_flow_entry
*tun_flow_create(struct tun_struct
*tun
,
210 struct hlist_head
*head
,
211 u32 rxhash
, u16 queue_index
)
213 struct tun_flow_entry
*e
= kmalloc(sizeof(*e
), GFP_ATOMIC
);
216 tun_debug(KERN_INFO
, tun
, "create flow: hash %u index %u\n",
217 rxhash
, queue_index
);
218 e
->updated
= jiffies
;
220 e
->queue_index
= queue_index
;
222 hlist_add_head_rcu(&e
->hash_link
, head
);
228 static void tun_flow_delete(struct tun_struct
*tun
, struct tun_flow_entry
*e
)
230 tun_debug(KERN_INFO
, tun
, "delete flow: hash %u index %u\n",
231 e
->rxhash
, e
->queue_index
);
232 hlist_del_rcu(&e
->hash_link
);
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
*n
;
246 hlist_for_each_entry_safe(e
, 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
*n
;
261 hlist_for_each_entry_safe(e
, 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
*n
;
284 hlist_for_each_entry_safe(e
, 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
,
301 struct tun_file
*tfile
)
303 struct hlist_head
*head
;
304 struct tun_flow_entry
*e
;
305 unsigned long delay
= tun
->ageing_time
;
306 u16 queue_index
= tfile
->queue_index
;
311 head
= &tun
->flows
[tun_hashfn(rxhash
)];
315 /* We may get a very small possibility of OOO during switching, not
316 * worth to optimize.*/
317 if (tun
->numqueues
== 1 || tfile
->detached
)
320 e
= tun_flow_find(head
, rxhash
);
322 /* TODO: keep queueing to old queue until it's empty? */
323 e
->queue_index
= queue_index
;
324 e
->updated
= jiffies
;
326 spin_lock_bh(&tun
->lock
);
327 if (!tun_flow_find(head
, rxhash
) &&
328 tun
->flow_count
< MAX_TAP_FLOWS
)
329 tun_flow_create(tun
, head
, rxhash
, queue_index
);
331 if (!timer_pending(&tun
->flow_gc_timer
))
332 mod_timer(&tun
->flow_gc_timer
,
333 round_jiffies_up(jiffies
+ delay
));
334 spin_unlock_bh(&tun
->lock
);
341 /* We try to identify a flow through its rxhash first. The reason that
342 * we do not check rxq no. is becuase some cards(e.g 82599), chooses
343 * the rxq based on the txq where the last packet of the flow comes. As
344 * the userspace application move between processors, we may get a
345 * different rxq no. here. If we could not get rxhash, then we would
346 * hope the rxq no. may help here.
348 static u16
tun_select_queue(struct net_device
*dev
, struct sk_buff
*skb
)
350 struct tun_struct
*tun
= netdev_priv(dev
);
351 struct tun_flow_entry
*e
;
356 numqueues
= ACCESS_ONCE(tun
->numqueues
);
358 txq
= skb_get_rxhash(skb
);
360 e
= tun_flow_find(&tun
->flows
[tun_hashfn(txq
)], txq
);
362 txq
= e
->queue_index
;
364 /* use multiply and shift instead of expensive divide */
365 txq
= ((u64
)txq
* numqueues
) >> 32;
366 } else if (likely(skb_rx_queue_recorded(skb
))) {
367 txq
= skb_get_rx_queue(skb
);
368 while (unlikely(txq
>= numqueues
))
376 static inline bool tun_not_capable(struct tun_struct
*tun
)
378 const struct cred
*cred
= current_cred();
379 struct net
*net
= dev_net(tun
->dev
);
381 return ((uid_valid(tun
->owner
) && !uid_eq(cred
->euid
, tun
->owner
)) ||
382 (gid_valid(tun
->group
) && !in_egroup_p(tun
->group
))) &&
383 !ns_capable(net
->user_ns
, CAP_NET_ADMIN
);
386 static void tun_set_real_num_queues(struct tun_struct
*tun
)
388 netif_set_real_num_tx_queues(tun
->dev
, tun
->numqueues
);
389 netif_set_real_num_rx_queues(tun
->dev
, tun
->numqueues
);
392 static void tun_disable_queue(struct tun_struct
*tun
, struct tun_file
*tfile
)
394 tfile
->detached
= tun
;
395 list_add_tail(&tfile
->next
, &tun
->disabled
);
399 static struct tun_struct
*tun_enable_queue(struct tun_file
*tfile
)
401 struct tun_struct
*tun
= tfile
->detached
;
403 tfile
->detached
= NULL
;
404 list_del_init(&tfile
->next
);
409 static void __tun_detach(struct tun_file
*tfile
, bool clean
)
411 struct tun_file
*ntfile
;
412 struct tun_struct
*tun
;
414 tun
= rtnl_dereference(tfile
->tun
);
416 if (tun
&& !tfile
->detached
) {
417 u16 index
= tfile
->queue_index
;
418 BUG_ON(index
>= tun
->numqueues
);
420 rcu_assign_pointer(tun
->tfiles
[index
],
421 tun
->tfiles
[tun
->numqueues
- 1]);
422 ntfile
= rtnl_dereference(tun
->tfiles
[index
]);
423 ntfile
->queue_index
= index
;
427 rcu_assign_pointer(tfile
->tun
, NULL
);
428 sock_put(&tfile
->sk
);
430 tun_disable_queue(tun
, tfile
);
433 tun_flow_delete_by_queue(tun
, tun
->numqueues
+ 1);
434 /* Drop read queue */
435 skb_queue_purge(&tfile
->sk
.sk_receive_queue
);
436 tun_set_real_num_queues(tun
);
437 } else if (tfile
->detached
&& clean
) {
438 tun
= tun_enable_queue(tfile
);
439 sock_put(&tfile
->sk
);
443 if (tun
&& tun
->numqueues
== 0 && tun
->numdisabled
== 0) {
444 netif_carrier_off(tun
->dev
);
446 if (!(tun
->flags
& TUN_PERSIST
) &&
447 tun
->dev
->reg_state
== NETREG_REGISTERED
)
448 unregister_netdevice(tun
->dev
);
451 BUG_ON(!test_bit(SOCK_EXTERNALLY_ALLOCATED
,
452 &tfile
->socket
.flags
));
453 sk_release_kernel(&tfile
->sk
);
457 static void tun_detach(struct tun_file
*tfile
, bool clean
)
460 __tun_detach(tfile
, clean
);
464 static void tun_detach_all(struct net_device
*dev
)
466 struct tun_struct
*tun
= netdev_priv(dev
);
467 struct tun_file
*tfile
, *tmp
;
468 int i
, n
= tun
->numqueues
;
470 for (i
= 0; i
< n
; i
++) {
471 tfile
= rtnl_dereference(tun
->tfiles
[i
]);
473 wake_up_all(&tfile
->wq
.wait
);
474 rcu_assign_pointer(tfile
->tun
, NULL
);
477 list_for_each_entry(tfile
, &tun
->disabled
, next
) {
478 wake_up_all(&tfile
->wq
.wait
);
479 rcu_assign_pointer(tfile
->tun
, NULL
);
481 BUG_ON(tun
->numqueues
!= 0);
484 for (i
= 0; i
< n
; i
++) {
485 tfile
= rtnl_dereference(tun
->tfiles
[i
]);
486 /* Drop read queue */
487 skb_queue_purge(&tfile
->sk
.sk_receive_queue
);
488 sock_put(&tfile
->sk
);
490 list_for_each_entry_safe(tfile
, tmp
, &tun
->disabled
, next
) {
491 tun_enable_queue(tfile
);
492 skb_queue_purge(&tfile
->sk
.sk_receive_queue
);
493 sock_put(&tfile
->sk
);
495 BUG_ON(tun
->numdisabled
!= 0);
497 if (tun
->flags
& TUN_PERSIST
)
498 module_put(THIS_MODULE
);
501 static int tun_attach(struct tun_struct
*tun
, struct file
*file
)
503 struct tun_file
*tfile
= file
->private_data
;
506 err
= security_tun_dev_attach(tfile
->socket
.sk
, tun
->security
);
511 if (rtnl_dereference(tfile
->tun
) && !tfile
->detached
)
515 if (!(tun
->flags
& TUN_TAP_MQ
) && tun
->numqueues
== 1)
519 if (!tfile
->detached
&&
520 tun
->numqueues
+ tun
->numdisabled
== MAX_TAP_QUEUES
)
525 /* Re-attach the filter to presist device */
526 if (tun
->filter_attached
== true) {
527 err
= sk_attach_filter(&tun
->fprog
, tfile
->socket
.sk
);
531 tfile
->queue_index
= tun
->numqueues
;
532 rcu_assign_pointer(tfile
->tun
, tun
);
533 rcu_assign_pointer(tun
->tfiles
[tun
->numqueues
], tfile
);
537 tun_enable_queue(tfile
);
539 sock_hold(&tfile
->sk
);
541 tun_set_real_num_queues(tun
);
543 /* device is allowed to go away first, so no need to hold extra
551 static struct tun_struct
*__tun_get(struct tun_file
*tfile
)
553 struct tun_struct
*tun
;
556 tun
= rcu_dereference(tfile
->tun
);
564 static struct tun_struct
*tun_get(struct file
*file
)
566 return __tun_get(file
->private_data
);
569 static void tun_put(struct tun_struct
*tun
)
575 static void addr_hash_set(u32
*mask
, const u8
*addr
)
577 int n
= ether_crc(ETH_ALEN
, addr
) >> 26;
578 mask
[n
>> 5] |= (1 << (n
& 31));
581 static unsigned int addr_hash_test(const u32
*mask
, const u8
*addr
)
583 int n
= ether_crc(ETH_ALEN
, addr
) >> 26;
584 return mask
[n
>> 5] & (1 << (n
& 31));
587 static int update_filter(struct tap_filter
*filter
, void __user
*arg
)
589 struct { u8 u
[ETH_ALEN
]; } *addr
;
590 struct tun_filter uf
;
591 int err
, alen
, n
, nexact
;
593 if (copy_from_user(&uf
, arg
, sizeof(uf
)))
602 alen
= ETH_ALEN
* uf
.count
;
603 addr
= kmalloc(alen
, GFP_KERNEL
);
607 if (copy_from_user(addr
, arg
+ sizeof(uf
), alen
)) {
612 /* The filter is updated without holding any locks. Which is
613 * perfectly safe. We disable it first and in the worst
614 * case we'll accept a few undesired packets. */
618 /* Use first set of addresses as an exact filter */
619 for (n
= 0; n
< uf
.count
&& n
< FLT_EXACT_COUNT
; n
++)
620 memcpy(filter
->addr
[n
], addr
[n
].u
, ETH_ALEN
);
624 /* Remaining multicast addresses are hashed,
625 * unicast will leave the filter disabled. */
626 memset(filter
->mask
, 0, sizeof(filter
->mask
));
627 for (; n
< uf
.count
; n
++) {
628 if (!is_multicast_ether_addr(addr
[n
].u
)) {
629 err
= 0; /* no filter */
632 addr_hash_set(filter
->mask
, addr
[n
].u
);
635 /* For ALLMULTI just set the mask to all ones.
636 * This overrides the mask populated above. */
637 if ((uf
.flags
& TUN_FLT_ALLMULTI
))
638 memset(filter
->mask
, ~0, sizeof(filter
->mask
));
640 /* Now enable the filter */
642 filter
->count
= nexact
;
644 /* Return the number of exact filters */
652 /* Returns: 0 - drop, !=0 - accept */
653 static int run_filter(struct tap_filter
*filter
, const struct sk_buff
*skb
)
655 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
657 struct ethhdr
*eh
= (struct ethhdr
*) skb
->data
;
661 for (i
= 0; i
< filter
->count
; i
++)
662 if (ether_addr_equal(eh
->h_dest
, filter
->addr
[i
]))
665 /* Inexact match (multicast only) */
666 if (is_multicast_ether_addr(eh
->h_dest
))
667 return addr_hash_test(filter
->mask
, eh
->h_dest
);
673 * Checks whether the packet is accepted or not.
674 * Returns: 0 - drop, !=0 - accept
676 static int check_filter(struct tap_filter
*filter
, const struct sk_buff
*skb
)
681 return run_filter(filter
, skb
);
684 /* Network device part of the driver */
686 static const struct ethtool_ops tun_ethtool_ops
;
688 /* Net device detach from fd. */
689 static void tun_net_uninit(struct net_device
*dev
)
694 /* Net device open. */
695 static int tun_net_open(struct net_device
*dev
)
697 netif_tx_start_all_queues(dev
);
701 /* Net device close. */
702 static int tun_net_close(struct net_device
*dev
)
704 netif_tx_stop_all_queues(dev
);
708 /* Net device start xmit */
709 static netdev_tx_t
tun_net_xmit(struct sk_buff
*skb
, struct net_device
*dev
)
711 struct tun_struct
*tun
= netdev_priv(dev
);
712 int txq
= skb
->queue_mapping
;
713 struct tun_file
*tfile
;
716 tfile
= rcu_dereference(tun
->tfiles
[txq
]);
718 /* Drop packet if interface is not attached */
719 if (txq
>= tun
->numqueues
)
722 tun_debug(KERN_INFO
, tun
, "tun_net_xmit %d\n", skb
->len
);
726 /* Drop if the filter does not like it.
727 * This is a noop if the filter is disabled.
728 * Filter can be enabled only for the TAP devices. */
729 if (!check_filter(&tun
->txflt
, skb
))
732 if (tfile
->socket
.sk
->sk_filter
&&
733 sk_filter(tfile
->socket
.sk
, skb
))
736 /* Limit the number of packets queued by dividing txq length with the
739 if (skb_queue_len(&tfile
->socket
.sk
->sk_receive_queue
)
740 >= dev
->tx_queue_len
/ tun
->numqueues
)
744 sock_tx_timestamp(skb
->sk
, &skb_shinfo(skb
)->tx_flags
);
745 sw_tx_timestamp(skb
);
748 /* Orphan the skb - required as we might hang on to it
749 * for indefinite time. */
750 if (unlikely(skb_orphan_frags(skb
, GFP_ATOMIC
)))
757 skb_queue_tail(&tfile
->socket
.sk
->sk_receive_queue
, skb
);
759 /* Notify and wake up reader process */
760 if (tfile
->flags
& TUN_FASYNC
)
761 kill_fasync(&tfile
->fasync
, SIGIO
, POLL_IN
);
762 wake_up_interruptible_poll(&tfile
->wq
.wait
, POLLIN
|
763 POLLRDNORM
| POLLRDBAND
);
769 dev
->stats
.tx_dropped
++;
776 static void tun_net_mclist(struct net_device
*dev
)
779 * This callback is supposed to deal with mc filter in
780 * _rx_ path and has nothing to do with the _tx_ path.
781 * In rx path we always accept everything userspace gives us.
786 #define MAX_MTU 65535
789 tun_net_change_mtu(struct net_device
*dev
, int new_mtu
)
791 if (new_mtu
< MIN_MTU
|| new_mtu
+ dev
->hard_header_len
> MAX_MTU
)
797 static netdev_features_t
tun_net_fix_features(struct net_device
*dev
,
798 netdev_features_t features
)
800 struct tun_struct
*tun
= netdev_priv(dev
);
802 return (features
& tun
->set_features
) | (features
& ~TUN_USER_FEATURES
);
804 #ifdef CONFIG_NET_POLL_CONTROLLER
805 static void tun_poll_controller(struct net_device
*dev
)
808 * Tun only receives frames when:
809 * 1) the char device endpoint gets data from user space
810 * 2) the tun socket gets a sendmsg call from user space
811 * Since both of those are syncronous operations, we are guaranteed
812 * never to have pending data when we poll for it
813 * so theres nothing to do here but return.
814 * We need this though so netpoll recognizes us as an interface that
815 * supports polling, which enables bridge devices in virt setups to
816 * still use netconsole
821 static const struct net_device_ops tun_netdev_ops
= {
822 .ndo_uninit
= tun_net_uninit
,
823 .ndo_open
= tun_net_open
,
824 .ndo_stop
= tun_net_close
,
825 .ndo_start_xmit
= tun_net_xmit
,
826 .ndo_change_mtu
= tun_net_change_mtu
,
827 .ndo_fix_features
= tun_net_fix_features
,
828 .ndo_select_queue
= tun_select_queue
,
829 #ifdef CONFIG_NET_POLL_CONTROLLER
830 .ndo_poll_controller
= tun_poll_controller
,
834 static const struct net_device_ops tap_netdev_ops
= {
835 .ndo_uninit
= tun_net_uninit
,
836 .ndo_open
= tun_net_open
,
837 .ndo_stop
= tun_net_close
,
838 .ndo_start_xmit
= tun_net_xmit
,
839 .ndo_change_mtu
= tun_net_change_mtu
,
840 .ndo_fix_features
= tun_net_fix_features
,
841 .ndo_set_rx_mode
= tun_net_mclist
,
842 .ndo_set_mac_address
= eth_mac_addr
,
843 .ndo_validate_addr
= eth_validate_addr
,
844 .ndo_select_queue
= tun_select_queue
,
845 #ifdef CONFIG_NET_POLL_CONTROLLER
846 .ndo_poll_controller
= tun_poll_controller
,
850 static void tun_flow_init(struct tun_struct
*tun
)
854 for (i
= 0; i
< TUN_NUM_FLOW_ENTRIES
; i
++)
855 INIT_HLIST_HEAD(&tun
->flows
[i
]);
857 tun
->ageing_time
= TUN_FLOW_EXPIRE
;
858 setup_timer(&tun
->flow_gc_timer
, tun_flow_cleanup
, (unsigned long)tun
);
859 mod_timer(&tun
->flow_gc_timer
,
860 round_jiffies_up(jiffies
+ tun
->ageing_time
));
863 static void tun_flow_uninit(struct tun_struct
*tun
)
865 del_timer_sync(&tun
->flow_gc_timer
);
869 /* Initialize net device. */
870 static void tun_net_init(struct net_device
*dev
)
872 struct tun_struct
*tun
= netdev_priv(dev
);
874 switch (tun
->flags
& TUN_TYPE_MASK
) {
876 dev
->netdev_ops
= &tun_netdev_ops
;
878 /* Point-to-Point TUN Device */
879 dev
->hard_header_len
= 0;
883 /* Zero header length */
884 dev
->type
= ARPHRD_NONE
;
885 dev
->flags
= IFF_POINTOPOINT
| IFF_NOARP
| IFF_MULTICAST
;
886 dev
->tx_queue_len
= TUN_READQ_SIZE
; /* We prefer our own queue length */
890 dev
->netdev_ops
= &tap_netdev_ops
;
891 /* Ethernet TAP Device */
893 dev
->priv_flags
&= ~IFF_TX_SKB_SHARING
;
894 dev
->priv_flags
|= IFF_LIVE_ADDR_CHANGE
;
896 eth_hw_addr_random(dev
);
898 dev
->tx_queue_len
= TUN_READQ_SIZE
; /* We prefer our own queue length */
903 /* Character device part */
906 static unsigned int tun_chr_poll(struct file
*file
, poll_table
*wait
)
908 struct tun_file
*tfile
= file
->private_data
;
909 struct tun_struct
*tun
= __tun_get(tfile
);
911 unsigned int mask
= 0;
916 sk
= tfile
->socket
.sk
;
918 tun_debug(KERN_INFO
, tun
, "tun_chr_poll\n");
920 poll_wait(file
, &tfile
->wq
.wait
, wait
);
922 if (!skb_queue_empty(&sk
->sk_receive_queue
))
923 mask
|= POLLIN
| POLLRDNORM
;
925 if (sock_writeable(sk
) ||
926 (!test_and_set_bit(SOCK_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
) &&
928 mask
|= POLLOUT
| POLLWRNORM
;
930 if (tun
->dev
->reg_state
!= NETREG_REGISTERED
)
937 /* prepad is the amount to reserve at front. len is length after that.
938 * linear is a hint as to how much to copy (usually headers). */
939 static struct sk_buff
*tun_alloc_skb(struct tun_file
*tfile
,
940 size_t prepad
, size_t len
,
941 size_t linear
, int noblock
)
943 struct sock
*sk
= tfile
->socket
.sk
;
947 /* Under a page? Don't bother with paged skb. */
948 if (prepad
+ len
< PAGE_SIZE
|| !linear
)
951 skb
= sock_alloc_send_pskb(sk
, prepad
+ linear
, len
- linear
, noblock
,
956 skb_reserve(skb
, prepad
);
957 skb_put(skb
, linear
);
958 skb
->data_len
= len
- linear
;
959 skb
->len
+= len
- linear
;
964 /* set skb frags from iovec, this can move to core network code for reuse */
965 static int zerocopy_sg_from_iovec(struct sk_buff
*skb
, const struct iovec
*from
,
966 int offset
, size_t count
)
968 int len
= iov_length(from
, count
) - offset
;
969 int copy
= skb_headlen(skb
);
970 int size
, offset1
= 0;
973 /* Skip over from offset */
974 while (count
&& (offset
>= from
->iov_len
)) {
975 offset
-= from
->iov_len
;
980 /* copy up to skb headlen */
981 while (count
&& (copy
> 0)) {
982 size
= min_t(unsigned int, copy
, from
->iov_len
- offset
);
983 if (copy_from_user(skb
->data
+ offset1
, from
->iov_base
+ offset
,
1000 struct page
*page
[MAX_SKB_FRAGS
];
1003 unsigned long truesize
;
1005 len
= from
->iov_len
- offset
;
1011 base
= (unsigned long)from
->iov_base
+ offset
;
1012 size
= ((base
& ~PAGE_MASK
) + len
+ ~PAGE_MASK
) >> PAGE_SHIFT
;
1013 if (i
+ size
> MAX_SKB_FRAGS
)
1015 num_pages
= get_user_pages_fast(base
, size
, 0, &page
[i
]);
1016 if (num_pages
!= size
) {
1019 for (j
= 0; j
< num_pages
; j
++)
1020 put_page(page
[i
+ j
]);
1023 truesize
= size
* PAGE_SIZE
;
1024 skb
->data_len
+= len
;
1026 skb
->truesize
+= truesize
;
1027 atomic_add(truesize
, &skb
->sk
->sk_wmem_alloc
);
1029 int off
= base
& ~PAGE_MASK
;
1030 int size
= min_t(int, len
, PAGE_SIZE
- off
);
1031 __skb_fill_page_desc(skb
, i
, page
[i
], off
, size
);
1032 skb_shinfo(skb
)->nr_frags
++;
1033 /* increase sk_wmem_alloc */
1044 /* Get packet from user space buffer */
1045 static ssize_t
tun_get_user(struct tun_struct
*tun
, struct tun_file
*tfile
,
1046 void *msg_control
, const struct iovec
*iv
,
1047 size_t total_len
, size_t count
, int noblock
)
1049 struct tun_pi pi
= { 0, cpu_to_be16(ETH_P_IP
) };
1050 struct sk_buff
*skb
;
1051 size_t len
= total_len
, align
= NET_SKB_PAD
, linear
;
1052 struct virtio_net_hdr gso
= { 0 };
1055 bool zerocopy
= false;
1059 if (!(tun
->flags
& TUN_NO_PI
)) {
1060 if ((len
-= sizeof(pi
)) > total_len
)
1063 if (memcpy_fromiovecend((void *)&pi
, iv
, 0, sizeof(pi
)))
1065 offset
+= sizeof(pi
);
1068 if (tun
->flags
& TUN_VNET_HDR
) {
1069 if ((len
-= tun
->vnet_hdr_sz
) > total_len
)
1072 if (memcpy_fromiovecend((void *)&gso
, iv
, offset
, sizeof(gso
)))
1075 if ((gso
.flags
& VIRTIO_NET_HDR_F_NEEDS_CSUM
) &&
1076 gso
.csum_start
+ gso
.csum_offset
+ 2 > gso
.hdr_len
)
1077 gso
.hdr_len
= gso
.csum_start
+ gso
.csum_offset
+ 2;
1079 if (gso
.hdr_len
> len
)
1081 offset
+= tun
->vnet_hdr_sz
;
1084 if ((tun
->flags
& TUN_TYPE_MASK
) == TUN_TAP_DEV
) {
1085 align
+= NET_IP_ALIGN
;
1086 if (unlikely(len
< ETH_HLEN
||
1087 (gso
.hdr_len
&& gso
.hdr_len
< ETH_HLEN
)))
1092 /* There are 256 bytes to be copied in skb, so there is
1093 * enough room for skb expand head in case it is used.
1094 * The rest of the buffer is mapped from userspace.
1096 copylen
= gso
.hdr_len
? gso
.hdr_len
: GOODCOPY_LEN
;
1098 if (iov_pages(iv
, offset
+ copylen
, count
) <= MAX_SKB_FRAGS
)
1104 linear
= gso
.hdr_len
;
1107 skb
= tun_alloc_skb(tfile
, align
, copylen
, linear
, noblock
);
1109 if (PTR_ERR(skb
) != -EAGAIN
)
1110 tun
->dev
->stats
.rx_dropped
++;
1111 return PTR_ERR(skb
);
1115 err
= zerocopy_sg_from_iovec(skb
, iv
, offset
, count
);
1117 err
= skb_copy_datagram_from_iovec(skb
, 0, iv
, offset
, len
);
1118 if (!err
&& msg_control
) {
1119 struct ubuf_info
*uarg
= msg_control
;
1120 uarg
->callback(uarg
, false);
1125 tun
->dev
->stats
.rx_dropped
++;
1130 if (gso
.flags
& VIRTIO_NET_HDR_F_NEEDS_CSUM
) {
1131 if (!skb_partial_csum_set(skb
, gso
.csum_start
,
1133 tun
->dev
->stats
.rx_frame_errors
++;
1139 switch (tun
->flags
& TUN_TYPE_MASK
) {
1141 if (tun
->flags
& TUN_NO_PI
) {
1142 switch (skb
->data
[0] & 0xf0) {
1144 pi
.proto
= htons(ETH_P_IP
);
1147 pi
.proto
= htons(ETH_P_IPV6
);
1150 tun
->dev
->stats
.rx_dropped
++;
1156 skb_reset_mac_header(skb
);
1157 skb
->protocol
= pi
.proto
;
1158 skb
->dev
= tun
->dev
;
1161 skb
->protocol
= eth_type_trans(skb
, tun
->dev
);
1165 if (gso
.gso_type
!= VIRTIO_NET_HDR_GSO_NONE
) {
1167 switch (gso
.gso_type
& ~VIRTIO_NET_HDR_GSO_ECN
) {
1168 case VIRTIO_NET_HDR_GSO_TCPV4
:
1169 skb_shinfo(skb
)->gso_type
= SKB_GSO_TCPV4
;
1171 case VIRTIO_NET_HDR_GSO_TCPV6
:
1172 skb_shinfo(skb
)->gso_type
= SKB_GSO_TCPV6
;
1174 case VIRTIO_NET_HDR_GSO_UDP
:
1175 skb_shinfo(skb
)->gso_type
= SKB_GSO_UDP
;
1178 tun
->dev
->stats
.rx_frame_errors
++;
1183 if (gso
.gso_type
& VIRTIO_NET_HDR_GSO_ECN
)
1184 skb_shinfo(skb
)->gso_type
|= SKB_GSO_TCP_ECN
;
1186 skb_shinfo(skb
)->gso_size
= gso
.gso_size
;
1187 if (skb_shinfo(skb
)->gso_size
== 0) {
1188 tun
->dev
->stats
.rx_frame_errors
++;
1193 /* Header must be checked, and gso_segs computed. */
1194 skb_shinfo(skb
)->gso_type
|= SKB_GSO_DODGY
;
1195 skb_shinfo(skb
)->gso_segs
= 0;
1198 /* copy skb_ubuf_info for callback when skb has no error */
1200 skb_shinfo(skb
)->destructor_arg
= msg_control
;
1201 skb_shinfo(skb
)->tx_flags
|= SKBTX_DEV_ZEROCOPY
;
1202 skb_shinfo(skb
)->tx_flags
|= SKBTX_SHARED_FRAG
;
1205 skb_reset_network_header(skb
);
1206 skb_probe_transport_header(skb
, 0);
1208 rxhash
= skb_get_rxhash(skb
);
1211 tun
->dev
->stats
.rx_packets
++;
1212 tun
->dev
->stats
.rx_bytes
+= len
;
1214 tun_flow_update(tun
, rxhash
, tfile
);
1218 static ssize_t
tun_chr_aio_write(struct kiocb
*iocb
, const struct iovec
*iv
,
1219 unsigned long count
, loff_t pos
)
1221 struct file
*file
= iocb
->ki_filp
;
1222 struct tun_struct
*tun
= tun_get(file
);
1223 struct tun_file
*tfile
= file
->private_data
;
1229 tun_debug(KERN_INFO
, tun
, "tun_chr_write %ld\n", count
);
1231 result
= tun_get_user(tun
, tfile
, NULL
, iv
, iov_length(iv
, count
),
1232 count
, file
->f_flags
& O_NONBLOCK
);
1238 /* Put packet to the user space buffer */
1239 static ssize_t
tun_put_user(struct tun_struct
*tun
,
1240 struct tun_file
*tfile
,
1241 struct sk_buff
*skb
,
1242 const struct iovec
*iv
, int len
)
1244 struct tun_pi pi
= { 0, skb
->protocol
};
1246 int vlan_offset
= 0;
1248 if (!(tun
->flags
& TUN_NO_PI
)) {
1249 if ((len
-= sizeof(pi
)) < 0)
1252 if (len
< skb
->len
) {
1253 /* Packet will be striped */
1254 pi
.flags
|= TUN_PKT_STRIP
;
1257 if (memcpy_toiovecend(iv
, (void *) &pi
, 0, sizeof(pi
)))
1259 total
+= sizeof(pi
);
1262 if (tun
->flags
& TUN_VNET_HDR
) {
1263 struct virtio_net_hdr gso
= { 0 }; /* no info leak */
1264 if ((len
-= tun
->vnet_hdr_sz
) < 0)
1267 if (skb_is_gso(skb
)) {
1268 struct skb_shared_info
*sinfo
= skb_shinfo(skb
);
1270 /* This is a hint as to how much should be linear. */
1271 gso
.hdr_len
= skb_headlen(skb
);
1272 gso
.gso_size
= sinfo
->gso_size
;
1273 if (sinfo
->gso_type
& SKB_GSO_TCPV4
)
1274 gso
.gso_type
= VIRTIO_NET_HDR_GSO_TCPV4
;
1275 else if (sinfo
->gso_type
& SKB_GSO_TCPV6
)
1276 gso
.gso_type
= VIRTIO_NET_HDR_GSO_TCPV6
;
1277 else if (sinfo
->gso_type
& SKB_GSO_UDP
)
1278 gso
.gso_type
= VIRTIO_NET_HDR_GSO_UDP
;
1280 pr_err("unexpected GSO type: "
1281 "0x%x, gso_size %d, hdr_len %d\n",
1282 sinfo
->gso_type
, gso
.gso_size
,
1284 print_hex_dump(KERN_ERR
, "tun: ",
1287 min((int)gso
.hdr_len
, 64), true);
1291 if (sinfo
->gso_type
& SKB_GSO_TCP_ECN
)
1292 gso
.gso_type
|= VIRTIO_NET_HDR_GSO_ECN
;
1294 gso
.gso_type
= VIRTIO_NET_HDR_GSO_NONE
;
1296 if (skb
->ip_summed
== CHECKSUM_PARTIAL
) {
1297 gso
.flags
= VIRTIO_NET_HDR_F_NEEDS_CSUM
;
1298 gso
.csum_start
= skb_checksum_start_offset(skb
);
1299 gso
.csum_offset
= skb
->csum_offset
;
1300 } else if (skb
->ip_summed
== CHECKSUM_UNNECESSARY
) {
1301 gso
.flags
= VIRTIO_NET_HDR_F_DATA_VALID
;
1302 } /* else everything is zero */
1304 if (unlikely(memcpy_toiovecend(iv
, (void *)&gso
, total
,
1307 total
+= tun
->vnet_hdr_sz
;
1310 if (!vlan_tx_tag_present(skb
)) {
1311 len
= min_t(int, skb
->len
, len
);
1315 __be16 h_vlan_proto
;
1319 veth
.h_vlan_proto
= skb
->vlan_proto
;
1320 veth
.h_vlan_TCI
= htons(vlan_tx_tag_get(skb
));
1322 vlan_offset
= offsetof(struct vlan_ethhdr
, h_vlan_proto
);
1323 len
= min_t(int, skb
->len
+ VLAN_HLEN
, len
);
1325 copy
= min_t(int, vlan_offset
, len
);
1326 ret
= skb_copy_datagram_const_iovec(skb
, 0, iv
, total
, copy
);
1332 copy
= min_t(int, sizeof(veth
), len
);
1333 ret
= memcpy_toiovecend(iv
, (void *)&veth
, total
, copy
);
1340 skb_copy_datagram_const_iovec(skb
, vlan_offset
, iv
, total
, len
);
1344 tun
->dev
->stats
.tx_packets
++;
1345 tun
->dev
->stats
.tx_bytes
+= len
;
1350 static ssize_t
tun_do_read(struct tun_struct
*tun
, struct tun_file
*tfile
,
1351 struct kiocb
*iocb
, const struct iovec
*iv
,
1352 ssize_t len
, int noblock
)
1354 DECLARE_WAITQUEUE(wait
, current
);
1355 struct sk_buff
*skb
;
1358 tun_debug(KERN_INFO
, tun
, "tun_do_read\n");
1360 if (unlikely(!noblock
))
1361 add_wait_queue(&tfile
->wq
.wait
, &wait
);
1363 current
->state
= TASK_INTERRUPTIBLE
;
1365 /* Read frames from the queue */
1366 if (!(skb
= skb_dequeue(&tfile
->socket
.sk
->sk_receive_queue
))) {
1371 if (signal_pending(current
)) {
1375 if (tun
->dev
->reg_state
!= NETREG_REGISTERED
) {
1380 /* Nothing to read, let's sleep */
1385 ret
= tun_put_user(tun
, tfile
, skb
, iv
, len
);
1390 current
->state
= TASK_RUNNING
;
1391 if (unlikely(!noblock
))
1392 remove_wait_queue(&tfile
->wq
.wait
, &wait
);
1397 static ssize_t
tun_chr_aio_read(struct kiocb
*iocb
, const struct iovec
*iv
,
1398 unsigned long count
, loff_t pos
)
1400 struct file
*file
= iocb
->ki_filp
;
1401 struct tun_file
*tfile
= file
->private_data
;
1402 struct tun_struct
*tun
= __tun_get(tfile
);
1407 len
= iov_length(iv
, count
);
1413 ret
= tun_do_read(tun
, tfile
, iocb
, iv
, len
,
1414 file
->f_flags
& O_NONBLOCK
);
1415 ret
= min_t(ssize_t
, ret
, len
);
1421 static void tun_free_netdev(struct net_device
*dev
)
1423 struct tun_struct
*tun
= netdev_priv(dev
);
1425 BUG_ON(!(list_empty(&tun
->disabled
)));
1426 tun_flow_uninit(tun
);
1427 security_tun_dev_free_security(tun
->security
);
1431 static void tun_setup(struct net_device
*dev
)
1433 struct tun_struct
*tun
= netdev_priv(dev
);
1435 tun
->owner
= INVALID_UID
;
1436 tun
->group
= INVALID_GID
;
1438 dev
->ethtool_ops
= &tun_ethtool_ops
;
1439 dev
->destructor
= tun_free_netdev
;
1442 /* Trivial set of netlink ops to allow deleting tun or tap
1443 * device with netlink.
1445 static int tun_validate(struct nlattr
*tb
[], struct nlattr
*data
[])
1450 static struct rtnl_link_ops tun_link_ops __read_mostly
= {
1452 .priv_size
= sizeof(struct tun_struct
),
1454 .validate
= tun_validate
,
1457 static void tun_sock_write_space(struct sock
*sk
)
1459 struct tun_file
*tfile
;
1460 wait_queue_head_t
*wqueue
;
1462 if (!sock_writeable(sk
))
1465 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
))
1468 wqueue
= sk_sleep(sk
);
1469 if (wqueue
&& waitqueue_active(wqueue
))
1470 wake_up_interruptible_sync_poll(wqueue
, POLLOUT
|
1471 POLLWRNORM
| POLLWRBAND
);
1473 tfile
= container_of(sk
, struct tun_file
, sk
);
1474 kill_fasync(&tfile
->fasync
, SIGIO
, POLL_OUT
);
1477 static int tun_sendmsg(struct kiocb
*iocb
, struct socket
*sock
,
1478 struct msghdr
*m
, size_t total_len
)
1481 struct tun_file
*tfile
= container_of(sock
, struct tun_file
, socket
);
1482 struct tun_struct
*tun
= __tun_get(tfile
);
1486 ret
= tun_get_user(tun
, tfile
, m
->msg_control
, m
->msg_iov
, total_len
,
1487 m
->msg_iovlen
, m
->msg_flags
& MSG_DONTWAIT
);
1492 static int tun_recvmsg(struct kiocb
*iocb
, struct socket
*sock
,
1493 struct msghdr
*m
, size_t total_len
,
1496 struct tun_file
*tfile
= container_of(sock
, struct tun_file
, socket
);
1497 struct tun_struct
*tun
= __tun_get(tfile
);
1503 if (flags
& ~(MSG_DONTWAIT
|MSG_TRUNC
|MSG_ERRQUEUE
)) {
1507 if (flags
& MSG_ERRQUEUE
) {
1508 ret
= sock_recv_errqueue(sock
->sk
, m
, total_len
,
1509 SOL_PACKET
, TUN_TX_TIMESTAMP
);
1512 ret
= tun_do_read(tun
, tfile
, iocb
, m
->msg_iov
, total_len
,
1513 flags
& MSG_DONTWAIT
);
1514 if (ret
> total_len
) {
1515 m
->msg_flags
|= MSG_TRUNC
;
1516 ret
= flags
& MSG_TRUNC
? ret
: total_len
;
1523 static int tun_release(struct socket
*sock
)
1530 /* Ops structure to mimic raw sockets with tun */
1531 static const struct proto_ops tun_socket_ops
= {
1532 .sendmsg
= tun_sendmsg
,
1533 .recvmsg
= tun_recvmsg
,
1534 .release
= tun_release
,
1537 static struct proto tun_proto
= {
1539 .owner
= THIS_MODULE
,
1540 .obj_size
= sizeof(struct tun_file
),
1543 static int tun_flags(struct tun_struct
*tun
)
1547 if (tun
->flags
& TUN_TUN_DEV
)
1552 if (tun
->flags
& TUN_NO_PI
)
1555 /* This flag has no real effect. We track the value for backwards
1558 if (tun
->flags
& TUN_ONE_QUEUE
)
1559 flags
|= IFF_ONE_QUEUE
;
1561 if (tun
->flags
& TUN_VNET_HDR
)
1562 flags
|= IFF_VNET_HDR
;
1564 if (tun
->flags
& TUN_TAP_MQ
)
1565 flags
|= IFF_MULTI_QUEUE
;
1567 if (tun
->flags
& TUN_PERSIST
)
1568 flags
|= IFF_PERSIST
;
1573 static ssize_t
tun_show_flags(struct device
*dev
, struct device_attribute
*attr
,
1576 struct tun_struct
*tun
= netdev_priv(to_net_dev(dev
));
1577 return sprintf(buf
, "0x%x\n", tun_flags(tun
));
1580 static ssize_t
tun_show_owner(struct device
*dev
, struct device_attribute
*attr
,
1583 struct tun_struct
*tun
= netdev_priv(to_net_dev(dev
));
1584 return uid_valid(tun
->owner
)?
1585 sprintf(buf
, "%u\n",
1586 from_kuid_munged(current_user_ns(), tun
->owner
)):
1587 sprintf(buf
, "-1\n");
1590 static ssize_t
tun_show_group(struct device
*dev
, struct device_attribute
*attr
,
1593 struct tun_struct
*tun
= netdev_priv(to_net_dev(dev
));
1594 return gid_valid(tun
->group
) ?
1595 sprintf(buf
, "%u\n",
1596 from_kgid_munged(current_user_ns(), tun
->group
)):
1597 sprintf(buf
, "-1\n");
1600 static DEVICE_ATTR(tun_flags
, 0444, tun_show_flags
, NULL
);
1601 static DEVICE_ATTR(owner
, 0444, tun_show_owner
, NULL
);
1602 static DEVICE_ATTR(group
, 0444, tun_show_group
, NULL
);
1604 static int tun_set_iff(struct net
*net
, struct file
*file
, struct ifreq
*ifr
)
1606 struct tun_struct
*tun
;
1607 struct tun_file
*tfile
= file
->private_data
;
1608 struct net_device
*dev
;
1611 if (tfile
->detached
)
1614 dev
= __dev_get_by_name(net
, ifr
->ifr_name
);
1616 if (ifr
->ifr_flags
& IFF_TUN_EXCL
)
1618 if ((ifr
->ifr_flags
& IFF_TUN
) && dev
->netdev_ops
== &tun_netdev_ops
)
1619 tun
= netdev_priv(dev
);
1620 else if ((ifr
->ifr_flags
& IFF_TAP
) && dev
->netdev_ops
== &tap_netdev_ops
)
1621 tun
= netdev_priv(dev
);
1625 if (!!(ifr
->ifr_flags
& IFF_MULTI_QUEUE
) !=
1626 !!(tun
->flags
& TUN_TAP_MQ
))
1629 if (tun_not_capable(tun
))
1631 err
= security_tun_dev_open(tun
->security
);
1635 err
= tun_attach(tun
, file
);
1639 if (tun
->flags
& TUN_TAP_MQ
&&
1640 (tun
->numqueues
+ tun
->numdisabled
> 1)) {
1641 /* One or more queue has already been attached, no need
1642 * to initialize the device again.
1649 unsigned long flags
= 0;
1650 int queues
= ifr
->ifr_flags
& IFF_MULTI_QUEUE
?
1653 if (!ns_capable(net
->user_ns
, CAP_NET_ADMIN
))
1655 err
= security_tun_dev_create();
1660 if (ifr
->ifr_flags
& IFF_TUN
) {
1662 flags
|= TUN_TUN_DEV
;
1664 } else if (ifr
->ifr_flags
& IFF_TAP
) {
1666 flags
|= TUN_TAP_DEV
;
1672 name
= ifr
->ifr_name
;
1674 dev
= alloc_netdev_mqs(sizeof(struct tun_struct
), name
,
1675 tun_setup
, queues
, queues
);
1680 dev_net_set(dev
, net
);
1681 dev
->rtnl_link_ops
= &tun_link_ops
;
1683 tun
= netdev_priv(dev
);
1686 tun
->txflt
.count
= 0;
1687 tun
->vnet_hdr_sz
= sizeof(struct virtio_net_hdr
);
1689 tun
->filter_attached
= false;
1690 tun
->sndbuf
= tfile
->socket
.sk
->sk_sndbuf
;
1692 spin_lock_init(&tun
->lock
);
1694 err
= security_tun_dev_alloc_security(&tun
->security
);
1701 dev
->hw_features
= NETIF_F_SG
| NETIF_F_FRAGLIST
|
1702 TUN_USER_FEATURES
| NETIF_F_HW_VLAN_CTAG_TX
|
1703 NETIF_F_HW_VLAN_STAG_TX
;
1704 dev
->features
= dev
->hw_features
;
1705 dev
->vlan_features
= dev
->features
;
1707 INIT_LIST_HEAD(&tun
->disabled
);
1708 err
= tun_attach(tun
, file
);
1712 err
= register_netdevice(tun
->dev
);
1716 if (device_create_file(&tun
->dev
->dev
, &dev_attr_tun_flags
) ||
1717 device_create_file(&tun
->dev
->dev
, &dev_attr_owner
) ||
1718 device_create_file(&tun
->dev
->dev
, &dev_attr_group
))
1719 pr_err("Failed to create tun sysfs files\n");
1722 netif_carrier_on(tun
->dev
);
1724 tun_debug(KERN_INFO
, tun
, "tun_set_iff\n");
1726 if (ifr
->ifr_flags
& IFF_NO_PI
)
1727 tun
->flags
|= TUN_NO_PI
;
1729 tun
->flags
&= ~TUN_NO_PI
;
1731 /* This flag has no real effect. We track the value for backwards
1734 if (ifr
->ifr_flags
& IFF_ONE_QUEUE
)
1735 tun
->flags
|= TUN_ONE_QUEUE
;
1737 tun
->flags
&= ~TUN_ONE_QUEUE
;
1739 if (ifr
->ifr_flags
& IFF_VNET_HDR
)
1740 tun
->flags
|= TUN_VNET_HDR
;
1742 tun
->flags
&= ~TUN_VNET_HDR
;
1744 if (ifr
->ifr_flags
& IFF_MULTI_QUEUE
)
1745 tun
->flags
|= TUN_TAP_MQ
;
1747 tun
->flags
&= ~TUN_TAP_MQ
;
1749 /* Make sure persistent devices do not get stuck in
1752 if (netif_running(tun
->dev
))
1753 netif_tx_wake_all_queues(tun
->dev
);
1755 strcpy(ifr
->ifr_name
, tun
->dev
->name
);
1763 static void tun_get_iff(struct net
*net
, struct tun_struct
*tun
,
1766 tun_debug(KERN_INFO
, tun
, "tun_get_iff\n");
1768 strcpy(ifr
->ifr_name
, tun
->dev
->name
);
1770 ifr
->ifr_flags
= tun_flags(tun
);
1774 /* This is like a cut-down ethtool ops, except done via tun fd so no
1775 * privs required. */
1776 static int set_offload(struct tun_struct
*tun
, unsigned long arg
)
1778 netdev_features_t features
= 0;
1780 if (arg
& TUN_F_CSUM
) {
1781 features
|= NETIF_F_HW_CSUM
;
1784 if (arg
& (TUN_F_TSO4
|TUN_F_TSO6
)) {
1785 if (arg
& TUN_F_TSO_ECN
) {
1786 features
|= NETIF_F_TSO_ECN
;
1787 arg
&= ~TUN_F_TSO_ECN
;
1789 if (arg
& TUN_F_TSO4
)
1790 features
|= NETIF_F_TSO
;
1791 if (arg
& TUN_F_TSO6
)
1792 features
|= NETIF_F_TSO6
;
1793 arg
&= ~(TUN_F_TSO4
|TUN_F_TSO6
);
1796 if (arg
& TUN_F_UFO
) {
1797 features
|= NETIF_F_UFO
;
1802 /* This gives the user a way to test for new features in future by
1803 * trying to set them. */
1807 tun
->set_features
= features
;
1808 netdev_update_features(tun
->dev
);
1813 static void tun_detach_filter(struct tun_struct
*tun
, int n
)
1816 struct tun_file
*tfile
;
1818 for (i
= 0; i
< n
; i
++) {
1819 tfile
= rtnl_dereference(tun
->tfiles
[i
]);
1820 sk_detach_filter(tfile
->socket
.sk
);
1823 tun
->filter_attached
= false;
1826 static int tun_attach_filter(struct tun_struct
*tun
)
1829 struct tun_file
*tfile
;
1831 for (i
= 0; i
< tun
->numqueues
; i
++) {
1832 tfile
= rtnl_dereference(tun
->tfiles
[i
]);
1833 ret
= sk_attach_filter(&tun
->fprog
, tfile
->socket
.sk
);
1835 tun_detach_filter(tun
, i
);
1840 tun
->filter_attached
= true;
1844 static void tun_set_sndbuf(struct tun_struct
*tun
)
1846 struct tun_file
*tfile
;
1849 for (i
= 0; i
< tun
->numqueues
; i
++) {
1850 tfile
= rtnl_dereference(tun
->tfiles
[i
]);
1851 tfile
->socket
.sk
->sk_sndbuf
= tun
->sndbuf
;
1855 static int tun_set_queue(struct file
*file
, struct ifreq
*ifr
)
1857 struct tun_file
*tfile
= file
->private_data
;
1858 struct tun_struct
*tun
;
1863 if (ifr
->ifr_flags
& IFF_ATTACH_QUEUE
) {
1864 tun
= tfile
->detached
;
1869 ret
= security_tun_dev_attach_queue(tun
->security
);
1872 ret
= tun_attach(tun
, file
);
1873 } else if (ifr
->ifr_flags
& IFF_DETACH_QUEUE
) {
1874 tun
= rtnl_dereference(tfile
->tun
);
1875 if (!tun
|| !(tun
->flags
& TUN_TAP_MQ
) || tfile
->detached
)
1878 __tun_detach(tfile
, false);
1887 static long __tun_chr_ioctl(struct file
*file
, unsigned int cmd
,
1888 unsigned long arg
, int ifreq_len
)
1890 struct tun_file
*tfile
= file
->private_data
;
1891 struct tun_struct
*tun
;
1892 void __user
* argp
= (void __user
*)arg
;
1900 if (cmd
== TUNSETIFF
|| cmd
== TUNSETQUEUE
|| _IOC_TYPE(cmd
) == 0x89) {
1901 if (copy_from_user(&ifr
, argp
, ifreq_len
))
1904 memset(&ifr
, 0, sizeof(ifr
));
1906 if (cmd
== TUNGETFEATURES
) {
1907 /* Currently this just means: "what IFF flags are valid?".
1908 * This is needed because we never checked for invalid flags on
1910 return put_user(IFF_TUN
| IFF_TAP
| IFF_NO_PI
| IFF_ONE_QUEUE
|
1911 IFF_VNET_HDR
| IFF_MULTI_QUEUE
,
1912 (unsigned int __user
*)argp
);
1913 } else if (cmd
== TUNSETQUEUE
)
1914 return tun_set_queue(file
, &ifr
);
1919 tun
= __tun_get(tfile
);
1920 if (cmd
== TUNSETIFF
&& !tun
) {
1921 ifr
.ifr_name
[IFNAMSIZ
-1] = '\0';
1923 ret
= tun_set_iff(tfile
->net
, file
, &ifr
);
1928 if (copy_to_user(argp
, &ifr
, ifreq_len
))
1937 tun_debug(KERN_INFO
, tun
, "tun_chr_ioctl cmd %u\n", cmd
);
1942 tun_get_iff(current
->nsproxy
->net_ns
, tun
, &ifr
);
1944 if (copy_to_user(argp
, &ifr
, ifreq_len
))
1949 /* Disable/Enable checksum */
1951 /* [unimplemented] */
1952 tun_debug(KERN_INFO
, tun
, "ignored: set checksum %s\n",
1953 arg
? "disabled" : "enabled");
1957 /* Disable/Enable persist mode. Keep an extra reference to the
1958 * module to prevent the module being unprobed.
1960 if (arg
&& !(tun
->flags
& TUN_PERSIST
)) {
1961 tun
->flags
|= TUN_PERSIST
;
1962 __module_get(THIS_MODULE
);
1964 if (!arg
&& (tun
->flags
& TUN_PERSIST
)) {
1965 tun
->flags
&= ~TUN_PERSIST
;
1966 module_put(THIS_MODULE
);
1969 tun_debug(KERN_INFO
, tun
, "persist %s\n",
1970 arg
? "enabled" : "disabled");
1974 /* Set owner of the device */
1975 owner
= make_kuid(current_user_ns(), arg
);
1976 if (!uid_valid(owner
)) {
1981 tun_debug(KERN_INFO
, tun
, "owner set to %u\n",
1982 from_kuid(&init_user_ns
, tun
->owner
));
1986 /* Set group of the device */
1987 group
= make_kgid(current_user_ns(), arg
);
1988 if (!gid_valid(group
)) {
1993 tun_debug(KERN_INFO
, tun
, "group set to %u\n",
1994 from_kgid(&init_user_ns
, tun
->group
));
1998 /* Only allow setting the type when the interface is down */
1999 if (tun
->dev
->flags
& IFF_UP
) {
2000 tun_debug(KERN_INFO
, tun
,
2001 "Linktype set failed because interface is up\n");
2004 tun
->dev
->type
= (int) arg
;
2005 tun_debug(KERN_INFO
, tun
, "linktype set to %d\n",
2017 ret
= set_offload(tun
, arg
);
2020 case TUNSETTXFILTER
:
2021 /* Can be set only for TAPs */
2023 if ((tun
->flags
& TUN_TYPE_MASK
) != TUN_TAP_DEV
)
2025 ret
= update_filter(&tun
->txflt
, (void __user
*)arg
);
2029 /* Get hw address */
2030 memcpy(ifr
.ifr_hwaddr
.sa_data
, tun
->dev
->dev_addr
, ETH_ALEN
);
2031 ifr
.ifr_hwaddr
.sa_family
= tun
->dev
->type
;
2032 if (copy_to_user(argp
, &ifr
, ifreq_len
))
2037 /* Set hw address */
2038 tun_debug(KERN_DEBUG
, tun
, "set hw address: %pM\n",
2039 ifr
.ifr_hwaddr
.sa_data
);
2041 ret
= dev_set_mac_address(tun
->dev
, &ifr
.ifr_hwaddr
);
2045 sndbuf
= tfile
->socket
.sk
->sk_sndbuf
;
2046 if (copy_to_user(argp
, &sndbuf
, sizeof(sndbuf
)))
2051 if (copy_from_user(&sndbuf
, argp
, sizeof(sndbuf
))) {
2056 tun
->sndbuf
= sndbuf
;
2057 tun_set_sndbuf(tun
);
2060 case TUNGETVNETHDRSZ
:
2061 vnet_hdr_sz
= tun
->vnet_hdr_sz
;
2062 if (copy_to_user(argp
, &vnet_hdr_sz
, sizeof(vnet_hdr_sz
)))
2066 case TUNSETVNETHDRSZ
:
2067 if (copy_from_user(&vnet_hdr_sz
, argp
, sizeof(vnet_hdr_sz
))) {
2071 if (vnet_hdr_sz
< (int)sizeof(struct virtio_net_hdr
)) {
2076 tun
->vnet_hdr_sz
= vnet_hdr_sz
;
2079 case TUNATTACHFILTER
:
2080 /* Can be set only for TAPs */
2082 if ((tun
->flags
& TUN_TYPE_MASK
) != TUN_TAP_DEV
)
2085 if (copy_from_user(&tun
->fprog
, argp
, sizeof(tun
->fprog
)))
2088 ret
= tun_attach_filter(tun
);
2091 case TUNDETACHFILTER
:
2092 /* Can be set only for TAPs */
2094 if ((tun
->flags
& TUN_TYPE_MASK
) != TUN_TAP_DEV
)
2097 tun_detach_filter(tun
, tun
->numqueues
);
2112 static long tun_chr_ioctl(struct file
*file
,
2113 unsigned int cmd
, unsigned long arg
)
2115 return __tun_chr_ioctl(file
, cmd
, arg
, sizeof (struct ifreq
));
2118 #ifdef CONFIG_COMPAT
2119 static long tun_chr_compat_ioctl(struct file
*file
,
2120 unsigned int cmd
, unsigned long arg
)
2125 case TUNSETTXFILTER
:
2130 arg
= (unsigned long)compat_ptr(arg
);
2133 arg
= (compat_ulong_t
)arg
;
2138 * compat_ifreq is shorter than ifreq, so we must not access beyond
2139 * the end of that structure. All fields that are used in this
2140 * driver are compatible though, we don't need to convert the
2143 return __tun_chr_ioctl(file
, cmd
, arg
, sizeof(struct compat_ifreq
));
2145 #endif /* CONFIG_COMPAT */
2147 static int tun_chr_fasync(int fd
, struct file
*file
, int on
)
2149 struct tun_file
*tfile
= file
->private_data
;
2152 if ((ret
= fasync_helper(fd
, file
, on
, &tfile
->fasync
)) < 0)
2156 ret
= __f_setown(file
, task_pid(current
), PIDTYPE_PID
, 0);
2159 tfile
->flags
|= TUN_FASYNC
;
2161 tfile
->flags
&= ~TUN_FASYNC
;
2167 static int tun_chr_open(struct inode
*inode
, struct file
* file
)
2169 struct tun_file
*tfile
;
2171 DBG1(KERN_INFO
, "tunX: tun_chr_open\n");
2173 tfile
= (struct tun_file
*)sk_alloc(&init_net
, AF_UNSPEC
, GFP_KERNEL
,
2177 rcu_assign_pointer(tfile
->tun
, NULL
);
2178 tfile
->net
= get_net(current
->nsproxy
->net_ns
);
2181 rcu_assign_pointer(tfile
->socket
.wq
, &tfile
->wq
);
2182 init_waitqueue_head(&tfile
->wq
.wait
);
2184 tfile
->socket
.file
= file
;
2185 tfile
->socket
.ops
= &tun_socket_ops
;
2187 sock_init_data(&tfile
->socket
, &tfile
->sk
);
2188 sk_change_net(&tfile
->sk
, tfile
->net
);
2190 tfile
->sk
.sk_write_space
= tun_sock_write_space
;
2191 tfile
->sk
.sk_sndbuf
= INT_MAX
;
2193 file
->private_data
= tfile
;
2194 set_bit(SOCK_EXTERNALLY_ALLOCATED
, &tfile
->socket
.flags
);
2195 INIT_LIST_HEAD(&tfile
->next
);
2197 sock_set_flag(&tfile
->sk
, SOCK_ZEROCOPY
);
2202 static int tun_chr_close(struct inode
*inode
, struct file
*file
)
2204 struct tun_file
*tfile
= file
->private_data
;
2205 struct net
*net
= tfile
->net
;
2207 tun_detach(tfile
, true);
2213 static const struct file_operations tun_fops
= {
2214 .owner
= THIS_MODULE
,
2215 .llseek
= no_llseek
,
2216 .read
= do_sync_read
,
2217 .aio_read
= tun_chr_aio_read
,
2218 .write
= do_sync_write
,
2219 .aio_write
= tun_chr_aio_write
,
2220 .poll
= tun_chr_poll
,
2221 .unlocked_ioctl
= tun_chr_ioctl
,
2222 #ifdef CONFIG_COMPAT
2223 .compat_ioctl
= tun_chr_compat_ioctl
,
2225 .open
= tun_chr_open
,
2226 .release
= tun_chr_close
,
2227 .fasync
= tun_chr_fasync
2230 static struct miscdevice tun_miscdev
= {
2233 .nodename
= "net/tun",
2237 /* ethtool interface */
2239 static int tun_get_settings(struct net_device
*dev
, struct ethtool_cmd
*cmd
)
2242 cmd
->advertising
= 0;
2243 ethtool_cmd_speed_set(cmd
, SPEED_10
);
2244 cmd
->duplex
= DUPLEX_FULL
;
2245 cmd
->port
= PORT_TP
;
2246 cmd
->phy_address
= 0;
2247 cmd
->transceiver
= XCVR_INTERNAL
;
2248 cmd
->autoneg
= AUTONEG_DISABLE
;
2254 static void tun_get_drvinfo(struct net_device
*dev
, struct ethtool_drvinfo
*info
)
2256 struct tun_struct
*tun
= netdev_priv(dev
);
2258 strlcpy(info
->driver
, DRV_NAME
, sizeof(info
->driver
));
2259 strlcpy(info
->version
, DRV_VERSION
, sizeof(info
->version
));
2261 switch (tun
->flags
& TUN_TYPE_MASK
) {
2263 strlcpy(info
->bus_info
, "tun", sizeof(info
->bus_info
));
2266 strlcpy(info
->bus_info
, "tap", sizeof(info
->bus_info
));
2271 static u32
tun_get_msglevel(struct net_device
*dev
)
2274 struct tun_struct
*tun
= netdev_priv(dev
);
2281 static void tun_set_msglevel(struct net_device
*dev
, u32 value
)
2284 struct tun_struct
*tun
= netdev_priv(dev
);
2289 static const struct ethtool_ops tun_ethtool_ops
= {
2290 .get_settings
= tun_get_settings
,
2291 .get_drvinfo
= tun_get_drvinfo
,
2292 .get_msglevel
= tun_get_msglevel
,
2293 .set_msglevel
= tun_set_msglevel
,
2294 .get_link
= ethtool_op_get_link
,
2295 .get_ts_info
= ethtool_op_get_ts_info
,
2299 static int __init
tun_init(void)
2303 pr_info("%s, %s\n", DRV_DESCRIPTION
, DRV_VERSION
);
2304 pr_info("%s\n", DRV_COPYRIGHT
);
2306 ret
= rtnl_link_register(&tun_link_ops
);
2308 pr_err("Can't register link_ops\n");
2312 ret
= misc_register(&tun_miscdev
);
2314 pr_err("Can't register misc device %d\n", TUN_MINOR
);
2319 rtnl_link_unregister(&tun_link_ops
);
2324 static void tun_cleanup(void)
2326 misc_deregister(&tun_miscdev
);
2327 rtnl_link_unregister(&tun_link_ops
);
2330 /* Get an underlying socket object from tun file. Returns error unless file is
2331 * attached to a device. The returned object works like a packet socket, it
2332 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
2333 * holding a reference to the file for as long as the socket is in use. */
2334 struct socket
*tun_get_socket(struct file
*file
)
2336 struct tun_file
*tfile
;
2337 if (file
->f_op
!= &tun_fops
)
2338 return ERR_PTR(-EINVAL
);
2339 tfile
= file
->private_data
;
2341 return ERR_PTR(-EBADFD
);
2342 return &tfile
->socket
;
2344 EXPORT_SYMBOL_GPL(tun_get_socket
);
2346 module_init(tun_init
);
2347 module_exit(tun_cleanup
);
2348 MODULE_DESCRIPTION(DRV_DESCRIPTION
);
2349 MODULE_AUTHOR(DRV_COPYRIGHT
);
2350 MODULE_LICENSE("GPL");
2351 MODULE_ALIAS_MISCDEV(TUN_MINOR
);
2352 MODULE_ALIAS("devname:net/tun");