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 */
143 unsigned int ifindex
;
145 struct list_head next
;
146 struct tun_struct
*detached
;
149 struct tun_flow_entry
{
150 struct hlist_node hash_link
;
152 struct tun_struct
*tun
;
156 unsigned long updated
;
159 #define TUN_NUM_FLOW_ENTRIES 1024
161 /* Since the socket were moved to tun_file, to preserve the behavior of persist
162 * device, socket filter, sndbuf and vnet header size were restore when the
163 * file were attached to a persist device.
166 struct tun_file __rcu
*tfiles
[MAX_TAP_QUEUES
];
167 unsigned int numqueues
;
172 struct net_device
*dev
;
173 netdev_features_t set_features
;
174 #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \
175 NETIF_F_TSO6|NETIF_F_UFO)
179 struct tap_filter txflt
;
180 struct sock_fprog fprog
;
181 /* protected by rtnl lock */
182 bool filter_attached
;
187 struct hlist_head flows
[TUN_NUM_FLOW_ENTRIES
];
188 struct timer_list flow_gc_timer
;
189 unsigned long ageing_time
;
190 unsigned int numdisabled
;
191 struct list_head disabled
;
196 static inline u32
tun_hashfn(u32 rxhash
)
198 return rxhash
& 0x3ff;
201 static struct tun_flow_entry
*tun_flow_find(struct hlist_head
*head
, u32 rxhash
)
203 struct tun_flow_entry
*e
;
205 hlist_for_each_entry_rcu(e
, head
, hash_link
) {
206 if (e
->rxhash
== rxhash
)
212 static struct tun_flow_entry
*tun_flow_create(struct tun_struct
*tun
,
213 struct hlist_head
*head
,
214 u32 rxhash
, u16 queue_index
)
216 struct tun_flow_entry
*e
= kmalloc(sizeof(*e
), GFP_ATOMIC
);
219 tun_debug(KERN_INFO
, tun
, "create flow: hash %u index %u\n",
220 rxhash
, queue_index
);
221 e
->updated
= jiffies
;
223 e
->queue_index
= queue_index
;
225 hlist_add_head_rcu(&e
->hash_link
, head
);
231 static void tun_flow_delete(struct tun_struct
*tun
, struct tun_flow_entry
*e
)
233 tun_debug(KERN_INFO
, tun
, "delete flow: hash %u index %u\n",
234 e
->rxhash
, e
->queue_index
);
235 hlist_del_rcu(&e
->hash_link
);
240 static void tun_flow_flush(struct tun_struct
*tun
)
244 spin_lock_bh(&tun
->lock
);
245 for (i
= 0; i
< TUN_NUM_FLOW_ENTRIES
; i
++) {
246 struct tun_flow_entry
*e
;
247 struct hlist_node
*n
;
249 hlist_for_each_entry_safe(e
, n
, &tun
->flows
[i
], hash_link
)
250 tun_flow_delete(tun
, e
);
252 spin_unlock_bh(&tun
->lock
);
255 static void tun_flow_delete_by_queue(struct tun_struct
*tun
, u16 queue_index
)
259 spin_lock_bh(&tun
->lock
);
260 for (i
= 0; i
< TUN_NUM_FLOW_ENTRIES
; i
++) {
261 struct tun_flow_entry
*e
;
262 struct hlist_node
*n
;
264 hlist_for_each_entry_safe(e
, n
, &tun
->flows
[i
], hash_link
) {
265 if (e
->queue_index
== queue_index
)
266 tun_flow_delete(tun
, e
);
269 spin_unlock_bh(&tun
->lock
);
272 static void tun_flow_cleanup(unsigned long data
)
274 struct tun_struct
*tun
= (struct tun_struct
*)data
;
275 unsigned long delay
= tun
->ageing_time
;
276 unsigned long next_timer
= jiffies
+ delay
;
277 unsigned long count
= 0;
280 tun_debug(KERN_INFO
, tun
, "tun_flow_cleanup\n");
282 spin_lock_bh(&tun
->lock
);
283 for (i
= 0; i
< TUN_NUM_FLOW_ENTRIES
; i
++) {
284 struct tun_flow_entry
*e
;
285 struct hlist_node
*n
;
287 hlist_for_each_entry_safe(e
, n
, &tun
->flows
[i
], hash_link
) {
288 unsigned long this_timer
;
290 this_timer
= e
->updated
+ delay
;
291 if (time_before_eq(this_timer
, jiffies
))
292 tun_flow_delete(tun
, e
);
293 else if (time_before(this_timer
, next_timer
))
294 next_timer
= this_timer
;
299 mod_timer(&tun
->flow_gc_timer
, round_jiffies_up(next_timer
));
300 spin_unlock_bh(&tun
->lock
);
303 static void tun_flow_update(struct tun_struct
*tun
, u32 rxhash
,
304 struct tun_file
*tfile
)
306 struct hlist_head
*head
;
307 struct tun_flow_entry
*e
;
308 unsigned long delay
= tun
->ageing_time
;
309 u16 queue_index
= tfile
->queue_index
;
314 head
= &tun
->flows
[tun_hashfn(rxhash
)];
318 /* We may get a very small possibility of OOO during switching, not
319 * worth to optimize.*/
320 if (tun
->numqueues
== 1 || tfile
->detached
)
323 e
= tun_flow_find(head
, rxhash
);
325 /* TODO: keep queueing to old queue until it's empty? */
326 e
->queue_index
= queue_index
;
327 e
->updated
= jiffies
;
329 spin_lock_bh(&tun
->lock
);
330 if (!tun_flow_find(head
, rxhash
) &&
331 tun
->flow_count
< MAX_TAP_FLOWS
)
332 tun_flow_create(tun
, head
, rxhash
, queue_index
);
334 if (!timer_pending(&tun
->flow_gc_timer
))
335 mod_timer(&tun
->flow_gc_timer
,
336 round_jiffies_up(jiffies
+ delay
));
337 spin_unlock_bh(&tun
->lock
);
344 /* We try to identify a flow through its rxhash first. The reason that
345 * we do not check rxq no. is becuase some cards(e.g 82599), chooses
346 * the rxq based on the txq where the last packet of the flow comes. As
347 * the userspace application move between processors, we may get a
348 * different rxq no. here. If we could not get rxhash, then we would
349 * hope the rxq no. may help here.
351 static u16
tun_select_queue(struct net_device
*dev
, struct sk_buff
*skb
,
354 struct tun_struct
*tun
= netdev_priv(dev
);
355 struct tun_flow_entry
*e
;
360 numqueues
= ACCESS_ONCE(tun
->numqueues
);
362 txq
= skb_get_rxhash(skb
);
364 e
= tun_flow_find(&tun
->flows
[tun_hashfn(txq
)], txq
);
366 txq
= e
->queue_index
;
368 /* use multiply and shift instead of expensive divide */
369 txq
= ((u64
)txq
* numqueues
) >> 32;
370 } else if (likely(skb_rx_queue_recorded(skb
))) {
371 txq
= skb_get_rx_queue(skb
);
372 while (unlikely(txq
>= numqueues
))
380 static inline bool tun_not_capable(struct tun_struct
*tun
)
382 const struct cred
*cred
= current_cred();
383 struct net
*net
= dev_net(tun
->dev
);
385 return ((uid_valid(tun
->owner
) && !uid_eq(cred
->euid
, tun
->owner
)) ||
386 (gid_valid(tun
->group
) && !in_egroup_p(tun
->group
))) &&
387 !ns_capable(net
->user_ns
, CAP_NET_ADMIN
);
390 static void tun_set_real_num_queues(struct tun_struct
*tun
)
392 netif_set_real_num_tx_queues(tun
->dev
, tun
->numqueues
);
393 netif_set_real_num_rx_queues(tun
->dev
, tun
->numqueues
);
396 static void tun_disable_queue(struct tun_struct
*tun
, struct tun_file
*tfile
)
398 tfile
->detached
= tun
;
399 list_add_tail(&tfile
->next
, &tun
->disabled
);
403 static struct tun_struct
*tun_enable_queue(struct tun_file
*tfile
)
405 struct tun_struct
*tun
= tfile
->detached
;
407 tfile
->detached
= NULL
;
408 list_del_init(&tfile
->next
);
413 static void tun_queue_purge(struct tun_file
*tfile
)
415 skb_queue_purge(&tfile
->sk
.sk_receive_queue
);
416 skb_queue_purge(&tfile
->sk
.sk_error_queue
);
419 static void __tun_detach(struct tun_file
*tfile
, bool clean
)
421 struct tun_file
*ntfile
;
422 struct tun_struct
*tun
;
424 tun
= rtnl_dereference(tfile
->tun
);
426 if (tun
&& !tfile
->detached
) {
427 u16 index
= tfile
->queue_index
;
428 BUG_ON(index
>= tun
->numqueues
);
430 rcu_assign_pointer(tun
->tfiles
[index
],
431 tun
->tfiles
[tun
->numqueues
- 1]);
432 ntfile
= rtnl_dereference(tun
->tfiles
[index
]);
433 ntfile
->queue_index
= index
;
437 rcu_assign_pointer(tfile
->tun
, NULL
);
438 sock_put(&tfile
->sk
);
440 tun_disable_queue(tun
, tfile
);
443 tun_flow_delete_by_queue(tun
, tun
->numqueues
+ 1);
444 /* Drop read queue */
445 tun_queue_purge(tfile
);
446 tun_set_real_num_queues(tun
);
447 } else if (tfile
->detached
&& clean
) {
448 tun
= tun_enable_queue(tfile
);
449 sock_put(&tfile
->sk
);
453 if (tun
&& tun
->numqueues
== 0 && tun
->numdisabled
== 0) {
454 netif_carrier_off(tun
->dev
);
456 if (!(tun
->flags
& TUN_PERSIST
) &&
457 tun
->dev
->reg_state
== NETREG_REGISTERED
)
458 unregister_netdevice(tun
->dev
);
461 BUG_ON(!test_bit(SOCK_EXTERNALLY_ALLOCATED
,
462 &tfile
->socket
.flags
));
463 sk_release_kernel(&tfile
->sk
);
467 static void tun_detach(struct tun_file
*tfile
, bool clean
)
470 __tun_detach(tfile
, clean
);
474 static void tun_detach_all(struct net_device
*dev
)
476 struct tun_struct
*tun
= netdev_priv(dev
);
477 struct tun_file
*tfile
, *tmp
;
478 int i
, n
= tun
->numqueues
;
480 for (i
= 0; i
< n
; i
++) {
481 tfile
= rtnl_dereference(tun
->tfiles
[i
]);
483 wake_up_all(&tfile
->wq
.wait
);
484 rcu_assign_pointer(tfile
->tun
, NULL
);
487 list_for_each_entry(tfile
, &tun
->disabled
, next
) {
488 wake_up_all(&tfile
->wq
.wait
);
489 rcu_assign_pointer(tfile
->tun
, NULL
);
491 BUG_ON(tun
->numqueues
!= 0);
494 for (i
= 0; i
< n
; i
++) {
495 tfile
= rtnl_dereference(tun
->tfiles
[i
]);
496 /* Drop read queue */
497 tun_queue_purge(tfile
);
498 sock_put(&tfile
->sk
);
500 list_for_each_entry_safe(tfile
, tmp
, &tun
->disabled
, next
) {
501 tun_enable_queue(tfile
);
502 tun_queue_purge(tfile
);
503 sock_put(&tfile
->sk
);
505 BUG_ON(tun
->numdisabled
!= 0);
507 if (tun
->flags
& TUN_PERSIST
)
508 module_put(THIS_MODULE
);
511 static int tun_attach(struct tun_struct
*tun
, struct file
*file
, bool skip_filter
)
513 struct tun_file
*tfile
= file
->private_data
;
516 err
= security_tun_dev_attach(tfile
->socket
.sk
, tun
->security
);
521 if (rtnl_dereference(tfile
->tun
) && !tfile
->detached
)
525 if (!(tun
->flags
& TUN_TAP_MQ
) && tun
->numqueues
== 1)
529 if (!tfile
->detached
&&
530 tun
->numqueues
+ tun
->numdisabled
== MAX_TAP_QUEUES
)
535 /* Re-attach the filter to presist device */
536 if (!skip_filter
&& (tun
->filter_attached
== true)) {
537 err
= sk_attach_filter(&tun
->fprog
, tfile
->socket
.sk
);
541 tfile
->queue_index
= tun
->numqueues
;
542 rcu_assign_pointer(tfile
->tun
, tun
);
543 rcu_assign_pointer(tun
->tfiles
[tun
->numqueues
], tfile
);
547 tun_enable_queue(tfile
);
549 sock_hold(&tfile
->sk
);
551 tun_set_real_num_queues(tun
);
553 /* device is allowed to go away first, so no need to hold extra
561 static struct tun_struct
*__tun_get(struct tun_file
*tfile
)
563 struct tun_struct
*tun
;
566 tun
= rcu_dereference(tfile
->tun
);
574 static struct tun_struct
*tun_get(struct file
*file
)
576 return __tun_get(file
->private_data
);
579 static void tun_put(struct tun_struct
*tun
)
585 static void addr_hash_set(u32
*mask
, const u8
*addr
)
587 int n
= ether_crc(ETH_ALEN
, addr
) >> 26;
588 mask
[n
>> 5] |= (1 << (n
& 31));
591 static unsigned int addr_hash_test(const u32
*mask
, const u8
*addr
)
593 int n
= ether_crc(ETH_ALEN
, addr
) >> 26;
594 return mask
[n
>> 5] & (1 << (n
& 31));
597 static int update_filter(struct tap_filter
*filter
, void __user
*arg
)
599 struct { u8 u
[ETH_ALEN
]; } *addr
;
600 struct tun_filter uf
;
601 int err
, alen
, n
, nexact
;
603 if (copy_from_user(&uf
, arg
, sizeof(uf
)))
612 alen
= ETH_ALEN
* uf
.count
;
613 addr
= kmalloc(alen
, GFP_KERNEL
);
617 if (copy_from_user(addr
, arg
+ sizeof(uf
), alen
)) {
622 /* The filter is updated without holding any locks. Which is
623 * perfectly safe. We disable it first and in the worst
624 * case we'll accept a few undesired packets. */
628 /* Use first set of addresses as an exact filter */
629 for (n
= 0; n
< uf
.count
&& n
< FLT_EXACT_COUNT
; n
++)
630 memcpy(filter
->addr
[n
], addr
[n
].u
, ETH_ALEN
);
634 /* Remaining multicast addresses are hashed,
635 * unicast will leave the filter disabled. */
636 memset(filter
->mask
, 0, sizeof(filter
->mask
));
637 for (; n
< uf
.count
; n
++) {
638 if (!is_multicast_ether_addr(addr
[n
].u
)) {
639 err
= 0; /* no filter */
642 addr_hash_set(filter
->mask
, addr
[n
].u
);
645 /* For ALLMULTI just set the mask to all ones.
646 * This overrides the mask populated above. */
647 if ((uf
.flags
& TUN_FLT_ALLMULTI
))
648 memset(filter
->mask
, ~0, sizeof(filter
->mask
));
650 /* Now enable the filter */
652 filter
->count
= nexact
;
654 /* Return the number of exact filters */
662 /* Returns: 0 - drop, !=0 - accept */
663 static int run_filter(struct tap_filter
*filter
, const struct sk_buff
*skb
)
665 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
667 struct ethhdr
*eh
= (struct ethhdr
*) skb
->data
;
671 for (i
= 0; i
< filter
->count
; i
++)
672 if (ether_addr_equal(eh
->h_dest
, filter
->addr
[i
]))
675 /* Inexact match (multicast only) */
676 if (is_multicast_ether_addr(eh
->h_dest
))
677 return addr_hash_test(filter
->mask
, eh
->h_dest
);
683 * Checks whether the packet is accepted or not.
684 * Returns: 0 - drop, !=0 - accept
686 static int check_filter(struct tap_filter
*filter
, const struct sk_buff
*skb
)
691 return run_filter(filter
, skb
);
694 /* Network device part of the driver */
696 static const struct ethtool_ops tun_ethtool_ops
;
698 /* Net device detach from fd. */
699 static void tun_net_uninit(struct net_device
*dev
)
704 /* Net device open. */
705 static int tun_net_open(struct net_device
*dev
)
707 netif_tx_start_all_queues(dev
);
711 /* Net device close. */
712 static int tun_net_close(struct net_device
*dev
)
714 netif_tx_stop_all_queues(dev
);
718 /* Net device start xmit */
719 static netdev_tx_t
tun_net_xmit(struct sk_buff
*skb
, struct net_device
*dev
)
721 struct tun_struct
*tun
= netdev_priv(dev
);
722 int txq
= skb
->queue_mapping
;
723 struct tun_file
*tfile
;
726 tfile
= rcu_dereference(tun
->tfiles
[txq
]);
728 /* Drop packet if interface is not attached */
729 if (txq
>= tun
->numqueues
)
732 tun_debug(KERN_INFO
, tun
, "tun_net_xmit %d\n", skb
->len
);
736 /* Drop if the filter does not like it.
737 * This is a noop if the filter is disabled.
738 * Filter can be enabled only for the TAP devices. */
739 if (!check_filter(&tun
->txflt
, skb
))
742 if (tfile
->socket
.sk
->sk_filter
&&
743 sk_filter(tfile
->socket
.sk
, skb
))
746 /* Limit the number of packets queued by dividing txq length with the
749 if (skb_queue_len(&tfile
->socket
.sk
->sk_receive_queue
)
750 >= dev
->tx_queue_len
/ tun
->numqueues
)
753 if (unlikely(skb_orphan_frags(skb
, GFP_ATOMIC
)))
757 sock_tx_timestamp(skb
->sk
, &skb_shinfo(skb
)->tx_flags
);
758 sw_tx_timestamp(skb
);
761 /* Orphan the skb - required as we might hang on to it
762 * for indefinite time.
769 skb_queue_tail(&tfile
->socket
.sk
->sk_receive_queue
, skb
);
771 /* Notify and wake up reader process */
772 if (tfile
->flags
& TUN_FASYNC
)
773 kill_fasync(&tfile
->fasync
, SIGIO
, POLL_IN
);
774 wake_up_interruptible_poll(&tfile
->wq
.wait
, POLLIN
|
775 POLLRDNORM
| POLLRDBAND
);
781 dev
->stats
.tx_dropped
++;
788 static void tun_net_mclist(struct net_device
*dev
)
791 * This callback is supposed to deal with mc filter in
792 * _rx_ path and has nothing to do with the _tx_ path.
793 * In rx path we always accept everything userspace gives us.
798 #define MAX_MTU 65535
801 tun_net_change_mtu(struct net_device
*dev
, int new_mtu
)
803 if (new_mtu
< MIN_MTU
|| new_mtu
+ dev
->hard_header_len
> MAX_MTU
)
809 static netdev_features_t
tun_net_fix_features(struct net_device
*dev
,
810 netdev_features_t features
)
812 struct tun_struct
*tun
= netdev_priv(dev
);
814 return (features
& tun
->set_features
) | (features
& ~TUN_USER_FEATURES
);
816 #ifdef CONFIG_NET_POLL_CONTROLLER
817 static void tun_poll_controller(struct net_device
*dev
)
820 * Tun only receives frames when:
821 * 1) the char device endpoint gets data from user space
822 * 2) the tun socket gets a sendmsg call from user space
823 * Since both of those are syncronous operations, we are guaranteed
824 * never to have pending data when we poll for it
825 * so theres nothing to do here but return.
826 * We need this though so netpoll recognizes us as an interface that
827 * supports polling, which enables bridge devices in virt setups to
828 * still use netconsole
833 static const struct net_device_ops tun_netdev_ops
= {
834 .ndo_uninit
= tun_net_uninit
,
835 .ndo_open
= tun_net_open
,
836 .ndo_stop
= tun_net_close
,
837 .ndo_start_xmit
= tun_net_xmit
,
838 .ndo_change_mtu
= tun_net_change_mtu
,
839 .ndo_fix_features
= tun_net_fix_features
,
840 .ndo_select_queue
= tun_select_queue
,
841 #ifdef CONFIG_NET_POLL_CONTROLLER
842 .ndo_poll_controller
= tun_poll_controller
,
846 static const struct net_device_ops tap_netdev_ops
= {
847 .ndo_uninit
= tun_net_uninit
,
848 .ndo_open
= tun_net_open
,
849 .ndo_stop
= tun_net_close
,
850 .ndo_start_xmit
= tun_net_xmit
,
851 .ndo_change_mtu
= tun_net_change_mtu
,
852 .ndo_fix_features
= tun_net_fix_features
,
853 .ndo_set_rx_mode
= tun_net_mclist
,
854 .ndo_set_mac_address
= eth_mac_addr
,
855 .ndo_validate_addr
= eth_validate_addr
,
856 .ndo_select_queue
= tun_select_queue
,
857 #ifdef CONFIG_NET_POLL_CONTROLLER
858 .ndo_poll_controller
= tun_poll_controller
,
862 static void tun_flow_init(struct tun_struct
*tun
)
866 for (i
= 0; i
< TUN_NUM_FLOW_ENTRIES
; i
++)
867 INIT_HLIST_HEAD(&tun
->flows
[i
]);
869 tun
->ageing_time
= TUN_FLOW_EXPIRE
;
870 setup_timer(&tun
->flow_gc_timer
, tun_flow_cleanup
, (unsigned long)tun
);
871 mod_timer(&tun
->flow_gc_timer
,
872 round_jiffies_up(jiffies
+ tun
->ageing_time
));
875 static void tun_flow_uninit(struct tun_struct
*tun
)
877 del_timer_sync(&tun
->flow_gc_timer
);
881 /* Initialize net device. */
882 static void tun_net_init(struct net_device
*dev
)
884 struct tun_struct
*tun
= netdev_priv(dev
);
886 switch (tun
->flags
& TUN_TYPE_MASK
) {
888 dev
->netdev_ops
= &tun_netdev_ops
;
890 /* Point-to-Point TUN Device */
891 dev
->hard_header_len
= 0;
895 /* Zero header length */
896 dev
->type
= ARPHRD_NONE
;
897 dev
->flags
= IFF_POINTOPOINT
| IFF_NOARP
| IFF_MULTICAST
;
898 dev
->tx_queue_len
= TUN_READQ_SIZE
; /* We prefer our own queue length */
902 dev
->netdev_ops
= &tap_netdev_ops
;
903 /* Ethernet TAP Device */
905 dev
->priv_flags
&= ~IFF_TX_SKB_SHARING
;
906 dev
->priv_flags
|= IFF_LIVE_ADDR_CHANGE
;
908 eth_hw_addr_random(dev
);
910 dev
->tx_queue_len
= TUN_READQ_SIZE
; /* We prefer our own queue length */
915 /* Character device part */
918 static unsigned int tun_chr_poll(struct file
*file
, poll_table
*wait
)
920 struct tun_file
*tfile
= file
->private_data
;
921 struct tun_struct
*tun
= __tun_get(tfile
);
923 unsigned int mask
= 0;
928 sk
= tfile
->socket
.sk
;
930 tun_debug(KERN_INFO
, tun
, "tun_chr_poll\n");
932 poll_wait(file
, &tfile
->wq
.wait
, wait
);
934 if (!skb_queue_empty(&sk
->sk_receive_queue
))
935 mask
|= POLLIN
| POLLRDNORM
;
937 if (sock_writeable(sk
) ||
938 (!test_and_set_bit(SOCK_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
) &&
940 mask
|= POLLOUT
| POLLWRNORM
;
942 if (tun
->dev
->reg_state
!= NETREG_REGISTERED
)
949 /* prepad is the amount to reserve at front. len is length after that.
950 * linear is a hint as to how much to copy (usually headers). */
951 static struct sk_buff
*tun_alloc_skb(struct tun_file
*tfile
,
952 size_t prepad
, size_t len
,
953 size_t linear
, int noblock
)
955 struct sock
*sk
= tfile
->socket
.sk
;
959 /* Under a page? Don't bother with paged skb. */
960 if (prepad
+ len
< PAGE_SIZE
|| !linear
)
963 skb
= sock_alloc_send_pskb(sk
, prepad
+ linear
, len
- linear
, noblock
,
968 skb_reserve(skb
, prepad
);
969 skb_put(skb
, linear
);
970 skb
->data_len
= len
- linear
;
971 skb
->len
+= len
- linear
;
976 /* Get packet from user space buffer */
977 static ssize_t
tun_get_user(struct tun_struct
*tun
, struct tun_file
*tfile
,
978 void *msg_control
, const struct iovec
*iv
,
979 size_t total_len
, size_t count
, int noblock
)
981 struct tun_pi pi
= { 0, cpu_to_be16(ETH_P_IP
) };
983 size_t len
= total_len
, align
= NET_SKB_PAD
, linear
;
984 struct virtio_net_hdr gso
= { 0 };
988 bool zerocopy
= false;
992 if (!(tun
->flags
& TUN_NO_PI
)) {
993 if (len
< sizeof(pi
))
997 if (memcpy_fromiovecend((void *)&pi
, iv
, 0, sizeof(pi
)))
999 offset
+= sizeof(pi
);
1002 if (tun
->flags
& TUN_VNET_HDR
) {
1003 if (len
< tun
->vnet_hdr_sz
)
1005 len
-= tun
->vnet_hdr_sz
;
1007 if (memcpy_fromiovecend((void *)&gso
, iv
, offset
, sizeof(gso
)))
1010 if ((gso
.flags
& VIRTIO_NET_HDR_F_NEEDS_CSUM
) &&
1011 gso
.csum_start
+ gso
.csum_offset
+ 2 > gso
.hdr_len
)
1012 gso
.hdr_len
= gso
.csum_start
+ gso
.csum_offset
+ 2;
1014 if (gso
.hdr_len
> len
)
1016 offset
+= tun
->vnet_hdr_sz
;
1019 if ((tun
->flags
& TUN_TYPE_MASK
) == TUN_TAP_DEV
) {
1020 align
+= NET_IP_ALIGN
;
1021 if (unlikely(len
< ETH_HLEN
||
1022 (gso
.hdr_len
&& gso
.hdr_len
< ETH_HLEN
)))
1026 good_linear
= SKB_MAX_HEAD(align
);
1029 /* There are 256 bytes to be copied in skb, so there is
1030 * enough room for skb expand head in case it is used.
1031 * The rest of the buffer is mapped from userspace.
1033 copylen
= gso
.hdr_len
? gso
.hdr_len
: GOODCOPY_LEN
;
1034 if (copylen
> good_linear
)
1035 copylen
= good_linear
;
1037 if (iov_pages(iv
, offset
+ copylen
, count
) <= MAX_SKB_FRAGS
)
1043 if (gso
.hdr_len
> good_linear
)
1044 linear
= good_linear
;
1046 linear
= gso
.hdr_len
;
1049 skb
= tun_alloc_skb(tfile
, align
, copylen
, linear
, noblock
);
1051 if (PTR_ERR(skb
) != -EAGAIN
)
1052 tun
->dev
->stats
.rx_dropped
++;
1053 return PTR_ERR(skb
);
1057 err
= zerocopy_sg_from_iovec(skb
, iv
, offset
, count
);
1059 err
= skb_copy_datagram_from_iovec(skb
, 0, iv
, offset
, len
);
1060 if (!err
&& msg_control
) {
1061 struct ubuf_info
*uarg
= msg_control
;
1062 uarg
->callback(uarg
, false);
1067 tun
->dev
->stats
.rx_dropped
++;
1072 if (gso
.flags
& VIRTIO_NET_HDR_F_NEEDS_CSUM
) {
1073 if (!skb_partial_csum_set(skb
, gso
.csum_start
,
1075 tun
->dev
->stats
.rx_frame_errors
++;
1081 switch (tun
->flags
& TUN_TYPE_MASK
) {
1083 if (tun
->flags
& TUN_NO_PI
) {
1084 switch (skb
->data
[0] & 0xf0) {
1086 pi
.proto
= htons(ETH_P_IP
);
1089 pi
.proto
= htons(ETH_P_IPV6
);
1092 tun
->dev
->stats
.rx_dropped
++;
1098 skb_reset_mac_header(skb
);
1099 skb
->protocol
= pi
.proto
;
1100 skb
->dev
= tun
->dev
;
1103 skb
->protocol
= eth_type_trans(skb
, tun
->dev
);
1107 if (gso
.gso_type
!= VIRTIO_NET_HDR_GSO_NONE
) {
1109 switch (gso
.gso_type
& ~VIRTIO_NET_HDR_GSO_ECN
) {
1110 case VIRTIO_NET_HDR_GSO_TCPV4
:
1111 skb_shinfo(skb
)->gso_type
= SKB_GSO_TCPV4
;
1113 case VIRTIO_NET_HDR_GSO_TCPV6
:
1114 skb_shinfo(skb
)->gso_type
= SKB_GSO_TCPV6
;
1116 case VIRTIO_NET_HDR_GSO_UDP
:
1117 skb_shinfo(skb
)->gso_type
= SKB_GSO_UDP
;
1120 tun
->dev
->stats
.rx_frame_errors
++;
1125 if (gso
.gso_type
& VIRTIO_NET_HDR_GSO_ECN
)
1126 skb_shinfo(skb
)->gso_type
|= SKB_GSO_TCP_ECN
;
1128 skb_shinfo(skb
)->gso_size
= gso
.gso_size
;
1129 if (skb_shinfo(skb
)->gso_size
== 0) {
1130 tun
->dev
->stats
.rx_frame_errors
++;
1135 /* Header must be checked, and gso_segs computed. */
1136 skb_shinfo(skb
)->gso_type
|= SKB_GSO_DODGY
;
1137 skb_shinfo(skb
)->gso_segs
= 0;
1140 /* copy skb_ubuf_info for callback when skb has no error */
1142 skb_shinfo(skb
)->destructor_arg
= msg_control
;
1143 skb_shinfo(skb
)->tx_flags
|= SKBTX_DEV_ZEROCOPY
;
1144 skb_shinfo(skb
)->tx_flags
|= SKBTX_SHARED_FRAG
;
1147 skb_reset_network_header(skb
);
1148 skb_probe_transport_header(skb
, 0);
1150 rxhash
= skb_get_rxhash(skb
);
1153 tun
->dev
->stats
.rx_packets
++;
1154 tun
->dev
->stats
.rx_bytes
+= len
;
1156 tun_flow_update(tun
, rxhash
, tfile
);
1160 static ssize_t
tun_chr_aio_write(struct kiocb
*iocb
, const struct iovec
*iv
,
1161 unsigned long count
, loff_t pos
)
1163 struct file
*file
= iocb
->ki_filp
;
1164 struct tun_struct
*tun
= tun_get(file
);
1165 struct tun_file
*tfile
= file
->private_data
;
1171 tun_debug(KERN_INFO
, tun
, "tun_chr_write %ld\n", count
);
1173 result
= tun_get_user(tun
, tfile
, NULL
, iv
, iov_length(iv
, count
),
1174 count
, file
->f_flags
& O_NONBLOCK
);
1180 /* Put packet to the user space buffer */
1181 static ssize_t
tun_put_user(struct tun_struct
*tun
,
1182 struct tun_file
*tfile
,
1183 struct sk_buff
*skb
,
1184 const struct iovec
*iv
, int len
)
1186 struct tun_pi pi
= { 0, skb
->protocol
};
1188 int vlan_offset
= 0, copied
;
1190 if (!(tun
->flags
& TUN_NO_PI
)) {
1191 if ((len
-= sizeof(pi
)) < 0)
1194 if (len
< skb
->len
) {
1195 /* Packet will be striped */
1196 pi
.flags
|= TUN_PKT_STRIP
;
1199 if (memcpy_toiovecend(iv
, (void *) &pi
, 0, sizeof(pi
)))
1201 total
+= sizeof(pi
);
1204 if (tun
->flags
& TUN_VNET_HDR
) {
1205 struct virtio_net_hdr gso
= { 0 }; /* no info leak */
1206 if ((len
-= tun
->vnet_hdr_sz
) < 0)
1209 if (skb_is_gso(skb
)) {
1210 struct skb_shared_info
*sinfo
= skb_shinfo(skb
);
1212 /* This is a hint as to how much should be linear. */
1213 gso
.hdr_len
= skb_headlen(skb
);
1214 gso
.gso_size
= sinfo
->gso_size
;
1215 if (sinfo
->gso_type
& SKB_GSO_TCPV4
)
1216 gso
.gso_type
= VIRTIO_NET_HDR_GSO_TCPV4
;
1217 else if (sinfo
->gso_type
& SKB_GSO_TCPV6
)
1218 gso
.gso_type
= VIRTIO_NET_HDR_GSO_TCPV6
;
1219 else if (sinfo
->gso_type
& SKB_GSO_UDP
)
1220 gso
.gso_type
= VIRTIO_NET_HDR_GSO_UDP
;
1222 pr_err("unexpected GSO type: "
1223 "0x%x, gso_size %d, hdr_len %d\n",
1224 sinfo
->gso_type
, gso
.gso_size
,
1226 print_hex_dump(KERN_ERR
, "tun: ",
1229 min((int)gso
.hdr_len
, 64), true);
1233 if (sinfo
->gso_type
& SKB_GSO_TCP_ECN
)
1234 gso
.gso_type
|= VIRTIO_NET_HDR_GSO_ECN
;
1236 gso
.gso_type
= VIRTIO_NET_HDR_GSO_NONE
;
1238 if (skb
->ip_summed
== CHECKSUM_PARTIAL
) {
1239 gso
.flags
= VIRTIO_NET_HDR_F_NEEDS_CSUM
;
1240 gso
.csum_start
= skb_checksum_start_offset(skb
);
1241 gso
.csum_offset
= skb
->csum_offset
;
1242 } else if (skb
->ip_summed
== CHECKSUM_UNNECESSARY
) {
1243 gso
.flags
= VIRTIO_NET_HDR_F_DATA_VALID
;
1244 } /* else everything is zero */
1246 if (unlikely(memcpy_toiovecend(iv
, (void *)&gso
, total
,
1249 total
+= tun
->vnet_hdr_sz
;
1254 if (!vlan_tx_tag_present(skb
)) {
1255 len
= min_t(int, skb
->len
, len
);
1259 __be16 h_vlan_proto
;
1263 veth
.h_vlan_proto
= skb
->vlan_proto
;
1264 veth
.h_vlan_TCI
= htons(vlan_tx_tag_get(skb
));
1266 vlan_offset
= offsetof(struct vlan_ethhdr
, h_vlan_proto
);
1267 len
= min_t(int, skb
->len
+ VLAN_HLEN
, len
);
1270 copy
= min_t(int, vlan_offset
, len
);
1271 ret
= skb_copy_datagram_const_iovec(skb
, 0, iv
, copied
, copy
);
1277 copy
= min_t(int, sizeof(veth
), len
);
1278 ret
= memcpy_toiovecend(iv
, (void *)&veth
, copied
, copy
);
1285 skb_copy_datagram_const_iovec(skb
, vlan_offset
, iv
, copied
, len
);
1288 tun
->dev
->stats
.tx_packets
++;
1289 tun
->dev
->stats
.tx_bytes
+= len
;
1294 static ssize_t
tun_do_read(struct tun_struct
*tun
, struct tun_file
*tfile
,
1295 struct kiocb
*iocb
, const struct iovec
*iv
,
1296 ssize_t len
, int noblock
)
1298 DECLARE_WAITQUEUE(wait
, current
);
1299 struct sk_buff
*skb
;
1302 tun_debug(KERN_INFO
, tun
, "tun_do_read\n");
1304 if (unlikely(!noblock
))
1305 add_wait_queue(&tfile
->wq
.wait
, &wait
);
1307 if (unlikely(!noblock
))
1308 current
->state
= TASK_INTERRUPTIBLE
;
1310 /* Read frames from the queue */
1311 if (!(skb
= skb_dequeue(&tfile
->socket
.sk
->sk_receive_queue
))) {
1316 if (signal_pending(current
)) {
1320 if (tun
->dev
->reg_state
!= NETREG_REGISTERED
) {
1325 /* Nothing to read, let's sleep */
1330 ret
= tun_put_user(tun
, tfile
, skb
, iv
, len
);
1335 if (unlikely(!noblock
)) {
1336 current
->state
= TASK_RUNNING
;
1337 remove_wait_queue(&tfile
->wq
.wait
, &wait
);
1343 static ssize_t
tun_chr_aio_read(struct kiocb
*iocb
, const struct iovec
*iv
,
1344 unsigned long count
, loff_t pos
)
1346 struct file
*file
= iocb
->ki_filp
;
1347 struct tun_file
*tfile
= file
->private_data
;
1348 struct tun_struct
*tun
= __tun_get(tfile
);
1353 len
= iov_length(iv
, count
);
1359 ret
= tun_do_read(tun
, tfile
, iocb
, iv
, len
,
1360 file
->f_flags
& O_NONBLOCK
);
1361 ret
= min_t(ssize_t
, ret
, len
);
1369 static void tun_free_netdev(struct net_device
*dev
)
1371 struct tun_struct
*tun
= netdev_priv(dev
);
1373 BUG_ON(!(list_empty(&tun
->disabled
)));
1374 tun_flow_uninit(tun
);
1375 security_tun_dev_free_security(tun
->security
);
1379 static void tun_setup(struct net_device
*dev
)
1381 struct tun_struct
*tun
= netdev_priv(dev
);
1383 tun
->owner
= INVALID_UID
;
1384 tun
->group
= INVALID_GID
;
1386 dev
->ethtool_ops
= &tun_ethtool_ops
;
1387 dev
->destructor
= tun_free_netdev
;
1390 /* Trivial set of netlink ops to allow deleting tun or tap
1391 * device with netlink.
1393 static int tun_validate(struct nlattr
*tb
[], struct nlattr
*data
[])
1398 static struct rtnl_link_ops tun_link_ops __read_mostly
= {
1400 .priv_size
= sizeof(struct tun_struct
),
1402 .validate
= tun_validate
,
1405 static void tun_sock_write_space(struct sock
*sk
)
1407 struct tun_file
*tfile
;
1408 wait_queue_head_t
*wqueue
;
1410 if (!sock_writeable(sk
))
1413 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
))
1416 wqueue
= sk_sleep(sk
);
1417 if (wqueue
&& waitqueue_active(wqueue
))
1418 wake_up_interruptible_sync_poll(wqueue
, POLLOUT
|
1419 POLLWRNORM
| POLLWRBAND
);
1421 tfile
= container_of(sk
, struct tun_file
, sk
);
1422 kill_fasync(&tfile
->fasync
, SIGIO
, POLL_OUT
);
1425 static int tun_sendmsg(struct kiocb
*iocb
, struct socket
*sock
,
1426 struct msghdr
*m
, size_t total_len
)
1429 struct tun_file
*tfile
= container_of(sock
, struct tun_file
, socket
);
1430 struct tun_struct
*tun
= __tun_get(tfile
);
1434 ret
= tun_get_user(tun
, tfile
, m
->msg_control
, m
->msg_iov
, total_len
,
1435 m
->msg_iovlen
, m
->msg_flags
& MSG_DONTWAIT
);
1440 static int tun_recvmsg(struct kiocb
*iocb
, struct socket
*sock
,
1441 struct msghdr
*m
, size_t total_len
,
1444 struct tun_file
*tfile
= container_of(sock
, struct tun_file
, socket
);
1445 struct tun_struct
*tun
= __tun_get(tfile
);
1451 if (flags
& ~(MSG_DONTWAIT
|MSG_TRUNC
|MSG_ERRQUEUE
)) {
1455 if (flags
& MSG_ERRQUEUE
) {
1456 ret
= sock_recv_errqueue(sock
->sk
, m
, total_len
,
1457 SOL_PACKET
, TUN_TX_TIMESTAMP
);
1460 ret
= tun_do_read(tun
, tfile
, iocb
, m
->msg_iov
, total_len
,
1461 flags
& MSG_DONTWAIT
);
1462 if (ret
> total_len
) {
1463 m
->msg_flags
|= MSG_TRUNC
;
1464 ret
= flags
& MSG_TRUNC
? ret
: total_len
;
1471 static int tun_release(struct socket
*sock
)
1478 /* Ops structure to mimic raw sockets with tun */
1479 static const struct proto_ops tun_socket_ops
= {
1480 .sendmsg
= tun_sendmsg
,
1481 .recvmsg
= tun_recvmsg
,
1482 .release
= tun_release
,
1485 static struct proto tun_proto
= {
1487 .owner
= THIS_MODULE
,
1488 .obj_size
= sizeof(struct tun_file
),
1491 static int tun_flags(struct tun_struct
*tun
)
1495 if (tun
->flags
& TUN_TUN_DEV
)
1500 if (tun
->flags
& TUN_NO_PI
)
1503 /* This flag has no real effect. We track the value for backwards
1506 if (tun
->flags
& TUN_ONE_QUEUE
)
1507 flags
|= IFF_ONE_QUEUE
;
1509 if (tun
->flags
& TUN_VNET_HDR
)
1510 flags
|= IFF_VNET_HDR
;
1512 if (tun
->flags
& TUN_TAP_MQ
)
1513 flags
|= IFF_MULTI_QUEUE
;
1515 if (tun
->flags
& TUN_PERSIST
)
1516 flags
|= IFF_PERSIST
;
1521 static ssize_t
tun_show_flags(struct device
*dev
, struct device_attribute
*attr
,
1524 struct tun_struct
*tun
= netdev_priv(to_net_dev(dev
));
1525 return sprintf(buf
, "0x%x\n", tun_flags(tun
));
1528 static ssize_t
tun_show_owner(struct device
*dev
, struct device_attribute
*attr
,
1531 struct tun_struct
*tun
= netdev_priv(to_net_dev(dev
));
1532 return uid_valid(tun
->owner
)?
1533 sprintf(buf
, "%u\n",
1534 from_kuid_munged(current_user_ns(), tun
->owner
)):
1535 sprintf(buf
, "-1\n");
1538 static ssize_t
tun_show_group(struct device
*dev
, struct device_attribute
*attr
,
1541 struct tun_struct
*tun
= netdev_priv(to_net_dev(dev
));
1542 return gid_valid(tun
->group
) ?
1543 sprintf(buf
, "%u\n",
1544 from_kgid_munged(current_user_ns(), tun
->group
)):
1545 sprintf(buf
, "-1\n");
1548 static DEVICE_ATTR(tun_flags
, 0444, tun_show_flags
, NULL
);
1549 static DEVICE_ATTR(owner
, 0444, tun_show_owner
, NULL
);
1550 static DEVICE_ATTR(group
, 0444, tun_show_group
, NULL
);
1552 static int tun_set_iff(struct net
*net
, struct file
*file
, struct ifreq
*ifr
)
1554 struct tun_struct
*tun
;
1555 struct tun_file
*tfile
= file
->private_data
;
1556 struct net_device
*dev
;
1559 if (tfile
->detached
)
1562 dev
= __dev_get_by_name(net
, ifr
->ifr_name
);
1564 if (ifr
->ifr_flags
& IFF_TUN_EXCL
)
1566 if ((ifr
->ifr_flags
& IFF_TUN
) && dev
->netdev_ops
== &tun_netdev_ops
)
1567 tun
= netdev_priv(dev
);
1568 else if ((ifr
->ifr_flags
& IFF_TAP
) && dev
->netdev_ops
== &tap_netdev_ops
)
1569 tun
= netdev_priv(dev
);
1573 if (!!(ifr
->ifr_flags
& IFF_MULTI_QUEUE
) !=
1574 !!(tun
->flags
& TUN_TAP_MQ
))
1577 if (tun_not_capable(tun
))
1579 err
= security_tun_dev_open(tun
->security
);
1583 err
= tun_attach(tun
, file
, ifr
->ifr_flags
& IFF_NOFILTER
);
1587 if (tun
->flags
& TUN_TAP_MQ
&&
1588 (tun
->numqueues
+ tun
->numdisabled
> 1)) {
1589 /* One or more queue has already been attached, no need
1590 * to initialize the device again.
1597 unsigned long flags
= 0;
1598 int queues
= ifr
->ifr_flags
& IFF_MULTI_QUEUE
?
1601 if (!ns_capable(net
->user_ns
, CAP_NET_ADMIN
))
1603 err
= security_tun_dev_create();
1608 if (ifr
->ifr_flags
& IFF_TUN
) {
1610 flags
|= TUN_TUN_DEV
;
1612 } else if (ifr
->ifr_flags
& IFF_TAP
) {
1614 flags
|= TUN_TAP_DEV
;
1620 name
= ifr
->ifr_name
;
1622 dev
= alloc_netdev_mqs(sizeof(struct tun_struct
), name
,
1623 tun_setup
, queues
, queues
);
1628 dev_net_set(dev
, net
);
1629 dev
->rtnl_link_ops
= &tun_link_ops
;
1630 dev
->ifindex
= tfile
->ifindex
;
1632 tun
= netdev_priv(dev
);
1635 tun
->txflt
.count
= 0;
1636 tun
->vnet_hdr_sz
= sizeof(struct virtio_net_hdr
);
1638 tun
->filter_attached
= false;
1639 tun
->sndbuf
= tfile
->socket
.sk
->sk_sndbuf
;
1641 spin_lock_init(&tun
->lock
);
1643 err
= security_tun_dev_alloc_security(&tun
->security
);
1650 dev
->hw_features
= NETIF_F_SG
| NETIF_F_FRAGLIST
|
1651 TUN_USER_FEATURES
| NETIF_F_HW_VLAN_CTAG_TX
|
1652 NETIF_F_HW_VLAN_STAG_TX
;
1653 dev
->features
= dev
->hw_features
;
1654 dev
->vlan_features
= dev
->features
;
1656 INIT_LIST_HEAD(&tun
->disabled
);
1657 err
= tun_attach(tun
, file
, false);
1661 err
= register_netdevice(tun
->dev
);
1665 if (device_create_file(&tun
->dev
->dev
, &dev_attr_tun_flags
) ||
1666 device_create_file(&tun
->dev
->dev
, &dev_attr_owner
) ||
1667 device_create_file(&tun
->dev
->dev
, &dev_attr_group
))
1668 pr_err("Failed to create tun sysfs files\n");
1671 netif_carrier_on(tun
->dev
);
1673 tun_debug(KERN_INFO
, tun
, "tun_set_iff\n");
1675 if (ifr
->ifr_flags
& IFF_NO_PI
)
1676 tun
->flags
|= TUN_NO_PI
;
1678 tun
->flags
&= ~TUN_NO_PI
;
1680 /* This flag has no real effect. We track the value for backwards
1683 if (ifr
->ifr_flags
& IFF_ONE_QUEUE
)
1684 tun
->flags
|= TUN_ONE_QUEUE
;
1686 tun
->flags
&= ~TUN_ONE_QUEUE
;
1688 if (ifr
->ifr_flags
& IFF_VNET_HDR
)
1689 tun
->flags
|= TUN_VNET_HDR
;
1691 tun
->flags
&= ~TUN_VNET_HDR
;
1693 if (ifr
->ifr_flags
& IFF_MULTI_QUEUE
)
1694 tun
->flags
|= TUN_TAP_MQ
;
1696 tun
->flags
&= ~TUN_TAP_MQ
;
1698 /* Make sure persistent devices do not get stuck in
1701 if (netif_running(tun
->dev
))
1702 netif_tx_wake_all_queues(tun
->dev
);
1704 strcpy(ifr
->ifr_name
, tun
->dev
->name
);
1708 tun_detach_all(dev
);
1710 tun_flow_uninit(tun
);
1711 security_tun_dev_free_security(tun
->security
);
1717 static void tun_get_iff(struct net
*net
, struct tun_struct
*tun
,
1720 tun_debug(KERN_INFO
, tun
, "tun_get_iff\n");
1722 strcpy(ifr
->ifr_name
, tun
->dev
->name
);
1724 ifr
->ifr_flags
= tun_flags(tun
);
1728 /* This is like a cut-down ethtool ops, except done via tun fd so no
1729 * privs required. */
1730 static int set_offload(struct tun_struct
*tun
, unsigned long arg
)
1732 netdev_features_t features
= 0;
1734 if (arg
& TUN_F_CSUM
) {
1735 features
|= NETIF_F_HW_CSUM
;
1738 if (arg
& (TUN_F_TSO4
|TUN_F_TSO6
)) {
1739 if (arg
& TUN_F_TSO_ECN
) {
1740 features
|= NETIF_F_TSO_ECN
;
1741 arg
&= ~TUN_F_TSO_ECN
;
1743 if (arg
& TUN_F_TSO4
)
1744 features
|= NETIF_F_TSO
;
1745 if (arg
& TUN_F_TSO6
)
1746 features
|= NETIF_F_TSO6
;
1747 arg
&= ~(TUN_F_TSO4
|TUN_F_TSO6
);
1750 if (arg
& TUN_F_UFO
) {
1751 features
|= NETIF_F_UFO
;
1756 /* This gives the user a way to test for new features in future by
1757 * trying to set them. */
1761 tun
->set_features
= features
;
1762 netdev_update_features(tun
->dev
);
1767 static void tun_detach_filter(struct tun_struct
*tun
, int n
)
1770 struct tun_file
*tfile
;
1772 for (i
= 0; i
< n
; i
++) {
1773 tfile
= rtnl_dereference(tun
->tfiles
[i
]);
1774 sk_detach_filter(tfile
->socket
.sk
);
1777 tun
->filter_attached
= false;
1780 static int tun_attach_filter(struct tun_struct
*tun
)
1783 struct tun_file
*tfile
;
1785 for (i
= 0; i
< tun
->numqueues
; i
++) {
1786 tfile
= rtnl_dereference(tun
->tfiles
[i
]);
1787 ret
= sk_attach_filter(&tun
->fprog
, tfile
->socket
.sk
);
1789 tun_detach_filter(tun
, i
);
1794 tun
->filter_attached
= true;
1798 static void tun_set_sndbuf(struct tun_struct
*tun
)
1800 struct tun_file
*tfile
;
1803 for (i
= 0; i
< tun
->numqueues
; i
++) {
1804 tfile
= rtnl_dereference(tun
->tfiles
[i
]);
1805 tfile
->socket
.sk
->sk_sndbuf
= tun
->sndbuf
;
1809 static int tun_set_queue(struct file
*file
, struct ifreq
*ifr
)
1811 struct tun_file
*tfile
= file
->private_data
;
1812 struct tun_struct
*tun
;
1817 if (ifr
->ifr_flags
& IFF_ATTACH_QUEUE
) {
1818 tun
= tfile
->detached
;
1823 ret
= security_tun_dev_attach_queue(tun
->security
);
1826 ret
= tun_attach(tun
, file
, false);
1827 } else if (ifr
->ifr_flags
& IFF_DETACH_QUEUE
) {
1828 tun
= rtnl_dereference(tfile
->tun
);
1829 if (!tun
|| !(tun
->flags
& TUN_TAP_MQ
) || tfile
->detached
)
1832 __tun_detach(tfile
, false);
1841 static long __tun_chr_ioctl(struct file
*file
, unsigned int cmd
,
1842 unsigned long arg
, int ifreq_len
)
1844 struct tun_file
*tfile
= file
->private_data
;
1845 struct tun_struct
*tun
;
1846 void __user
* argp
= (void __user
*)arg
;
1852 unsigned int ifindex
;
1855 if (cmd
== TUNSETIFF
|| cmd
== TUNSETQUEUE
|| _IOC_TYPE(cmd
) == 0x89) {
1856 if (copy_from_user(&ifr
, argp
, ifreq_len
))
1859 memset(&ifr
, 0, sizeof(ifr
));
1861 if (cmd
== TUNGETFEATURES
) {
1862 /* Currently this just means: "what IFF flags are valid?".
1863 * This is needed because we never checked for invalid flags on
1865 return put_user(IFF_TUN
| IFF_TAP
| IFF_NO_PI
| IFF_ONE_QUEUE
|
1866 IFF_VNET_HDR
| IFF_MULTI_QUEUE
,
1867 (unsigned int __user
*)argp
);
1868 } else if (cmd
== TUNSETQUEUE
)
1869 return tun_set_queue(file
, &ifr
);
1874 tun
= __tun_get(tfile
);
1875 if (cmd
== TUNSETIFF
&& !tun
) {
1876 ifr
.ifr_name
[IFNAMSIZ
-1] = '\0';
1878 ret
= tun_set_iff(tfile
->net
, file
, &ifr
);
1883 if (copy_to_user(argp
, &ifr
, ifreq_len
))
1887 if (cmd
== TUNSETIFINDEX
) {
1893 if (copy_from_user(&ifindex
, argp
, sizeof(ifindex
)))
1897 tfile
->ifindex
= ifindex
;
1905 tun_debug(KERN_INFO
, tun
, "tun_chr_ioctl cmd %u\n", cmd
);
1910 tun_get_iff(current
->nsproxy
->net_ns
, tun
, &ifr
);
1912 if (tfile
->detached
)
1913 ifr
.ifr_flags
|= IFF_DETACH_QUEUE
;
1914 if (!tfile
->socket
.sk
->sk_filter
)
1915 ifr
.ifr_flags
|= IFF_NOFILTER
;
1917 if (copy_to_user(argp
, &ifr
, ifreq_len
))
1922 /* Disable/Enable checksum */
1924 /* [unimplemented] */
1925 tun_debug(KERN_INFO
, tun
, "ignored: set checksum %s\n",
1926 arg
? "disabled" : "enabled");
1930 /* Disable/Enable persist mode. Keep an extra reference to the
1931 * module to prevent the module being unprobed.
1933 if (arg
&& !(tun
->flags
& TUN_PERSIST
)) {
1934 tun
->flags
|= TUN_PERSIST
;
1935 __module_get(THIS_MODULE
);
1937 if (!arg
&& (tun
->flags
& TUN_PERSIST
)) {
1938 tun
->flags
&= ~TUN_PERSIST
;
1939 module_put(THIS_MODULE
);
1942 tun_debug(KERN_INFO
, tun
, "persist %s\n",
1943 arg
? "enabled" : "disabled");
1947 /* Set owner of the device */
1948 owner
= make_kuid(current_user_ns(), arg
);
1949 if (!uid_valid(owner
)) {
1954 tun_debug(KERN_INFO
, tun
, "owner set to %u\n",
1955 from_kuid(&init_user_ns
, tun
->owner
));
1959 /* Set group of the device */
1960 group
= make_kgid(current_user_ns(), arg
);
1961 if (!gid_valid(group
)) {
1966 tun_debug(KERN_INFO
, tun
, "group set to %u\n",
1967 from_kgid(&init_user_ns
, tun
->group
));
1971 /* Only allow setting the type when the interface is down */
1972 if (tun
->dev
->flags
& IFF_UP
) {
1973 tun_debug(KERN_INFO
, tun
,
1974 "Linktype set failed because interface is up\n");
1977 tun
->dev
->type
= (int) arg
;
1978 tun_debug(KERN_INFO
, tun
, "linktype set to %d\n",
1990 ret
= set_offload(tun
, arg
);
1993 case TUNSETTXFILTER
:
1994 /* Can be set only for TAPs */
1996 if ((tun
->flags
& TUN_TYPE_MASK
) != TUN_TAP_DEV
)
1998 ret
= update_filter(&tun
->txflt
, (void __user
*)arg
);
2002 /* Get hw address */
2003 memcpy(ifr
.ifr_hwaddr
.sa_data
, tun
->dev
->dev_addr
, ETH_ALEN
);
2004 ifr
.ifr_hwaddr
.sa_family
= tun
->dev
->type
;
2005 if (copy_to_user(argp
, &ifr
, ifreq_len
))
2010 /* Set hw address */
2011 tun_debug(KERN_DEBUG
, tun
, "set hw address: %pM\n",
2012 ifr
.ifr_hwaddr
.sa_data
);
2014 ret
= dev_set_mac_address(tun
->dev
, &ifr
.ifr_hwaddr
);
2018 sndbuf
= tfile
->socket
.sk
->sk_sndbuf
;
2019 if (copy_to_user(argp
, &sndbuf
, sizeof(sndbuf
)))
2024 if (copy_from_user(&sndbuf
, argp
, sizeof(sndbuf
))) {
2029 tun
->sndbuf
= sndbuf
;
2030 tun_set_sndbuf(tun
);
2033 case TUNGETVNETHDRSZ
:
2034 vnet_hdr_sz
= tun
->vnet_hdr_sz
;
2035 if (copy_to_user(argp
, &vnet_hdr_sz
, sizeof(vnet_hdr_sz
)))
2039 case TUNSETVNETHDRSZ
:
2040 if (copy_from_user(&vnet_hdr_sz
, argp
, sizeof(vnet_hdr_sz
))) {
2044 if (vnet_hdr_sz
< (int)sizeof(struct virtio_net_hdr
)) {
2049 tun
->vnet_hdr_sz
= vnet_hdr_sz
;
2052 case TUNATTACHFILTER
:
2053 /* Can be set only for TAPs */
2055 if ((tun
->flags
& TUN_TYPE_MASK
) != TUN_TAP_DEV
)
2058 if (copy_from_user(&tun
->fprog
, argp
, sizeof(tun
->fprog
)))
2061 ret
= tun_attach_filter(tun
);
2064 case TUNDETACHFILTER
:
2065 /* Can be set only for TAPs */
2067 if ((tun
->flags
& TUN_TYPE_MASK
) != TUN_TAP_DEV
)
2070 tun_detach_filter(tun
, tun
->numqueues
);
2075 if ((tun
->flags
& TUN_TYPE_MASK
) != TUN_TAP_DEV
)
2078 if (copy_to_user(argp
, &tun
->fprog
, sizeof(tun
->fprog
)))
2095 static long tun_chr_ioctl(struct file
*file
,
2096 unsigned int cmd
, unsigned long arg
)
2098 return __tun_chr_ioctl(file
, cmd
, arg
, sizeof (struct ifreq
));
2101 #ifdef CONFIG_COMPAT
2102 static long tun_chr_compat_ioctl(struct file
*file
,
2103 unsigned int cmd
, unsigned long arg
)
2108 case TUNSETTXFILTER
:
2113 arg
= (unsigned long)compat_ptr(arg
);
2116 arg
= (compat_ulong_t
)arg
;
2121 * compat_ifreq is shorter than ifreq, so we must not access beyond
2122 * the end of that structure. All fields that are used in this
2123 * driver are compatible though, we don't need to convert the
2126 return __tun_chr_ioctl(file
, cmd
, arg
, sizeof(struct compat_ifreq
));
2128 #endif /* CONFIG_COMPAT */
2130 static int tun_chr_fasync(int fd
, struct file
*file
, int on
)
2132 struct tun_file
*tfile
= file
->private_data
;
2135 if ((ret
= fasync_helper(fd
, file
, on
, &tfile
->fasync
)) < 0)
2139 ret
= __f_setown(file
, task_pid(current
), PIDTYPE_PID
, 0);
2142 tfile
->flags
|= TUN_FASYNC
;
2144 tfile
->flags
&= ~TUN_FASYNC
;
2150 static int tun_chr_open(struct inode
*inode
, struct file
* file
)
2152 struct tun_file
*tfile
;
2154 DBG1(KERN_INFO
, "tunX: tun_chr_open\n");
2156 tfile
= (struct tun_file
*)sk_alloc(&init_net
, AF_UNSPEC
, GFP_KERNEL
,
2160 rcu_assign_pointer(tfile
->tun
, NULL
);
2161 tfile
->net
= get_net(current
->nsproxy
->net_ns
);
2165 rcu_assign_pointer(tfile
->socket
.wq
, &tfile
->wq
);
2166 init_waitqueue_head(&tfile
->wq
.wait
);
2168 tfile
->socket
.file
= file
;
2169 tfile
->socket
.ops
= &tun_socket_ops
;
2171 sock_init_data(&tfile
->socket
, &tfile
->sk
);
2172 sk_change_net(&tfile
->sk
, tfile
->net
);
2174 tfile
->sk
.sk_write_space
= tun_sock_write_space
;
2175 tfile
->sk
.sk_sndbuf
= INT_MAX
;
2177 file
->private_data
= tfile
;
2178 set_bit(SOCK_EXTERNALLY_ALLOCATED
, &tfile
->socket
.flags
);
2179 INIT_LIST_HEAD(&tfile
->next
);
2181 sock_set_flag(&tfile
->sk
, SOCK_ZEROCOPY
);
2186 static int tun_chr_close(struct inode
*inode
, struct file
*file
)
2188 struct tun_file
*tfile
= file
->private_data
;
2189 struct net
*net
= tfile
->net
;
2191 tun_detach(tfile
, true);
2197 static const struct file_operations tun_fops
= {
2198 .owner
= THIS_MODULE
,
2199 .llseek
= no_llseek
,
2200 .read
= do_sync_read
,
2201 .aio_read
= tun_chr_aio_read
,
2202 .write
= do_sync_write
,
2203 .aio_write
= tun_chr_aio_write
,
2204 .poll
= tun_chr_poll
,
2205 .unlocked_ioctl
= tun_chr_ioctl
,
2206 #ifdef CONFIG_COMPAT
2207 .compat_ioctl
= tun_chr_compat_ioctl
,
2209 .open
= tun_chr_open
,
2210 .release
= tun_chr_close
,
2211 .fasync
= tun_chr_fasync
2214 static struct miscdevice tun_miscdev
= {
2217 .nodename
= "net/tun",
2221 /* ethtool interface */
2223 static int tun_get_settings(struct net_device
*dev
, struct ethtool_cmd
*cmd
)
2226 cmd
->advertising
= 0;
2227 ethtool_cmd_speed_set(cmd
, SPEED_10
);
2228 cmd
->duplex
= DUPLEX_FULL
;
2229 cmd
->port
= PORT_TP
;
2230 cmd
->phy_address
= 0;
2231 cmd
->transceiver
= XCVR_INTERNAL
;
2232 cmd
->autoneg
= AUTONEG_DISABLE
;
2238 static void tun_get_drvinfo(struct net_device
*dev
, struct ethtool_drvinfo
*info
)
2240 struct tun_struct
*tun
= netdev_priv(dev
);
2242 strlcpy(info
->driver
, DRV_NAME
, sizeof(info
->driver
));
2243 strlcpy(info
->version
, DRV_VERSION
, sizeof(info
->version
));
2245 switch (tun
->flags
& TUN_TYPE_MASK
) {
2247 strlcpy(info
->bus_info
, "tun", sizeof(info
->bus_info
));
2250 strlcpy(info
->bus_info
, "tap", sizeof(info
->bus_info
));
2255 static u32
tun_get_msglevel(struct net_device
*dev
)
2258 struct tun_struct
*tun
= netdev_priv(dev
);
2265 static void tun_set_msglevel(struct net_device
*dev
, u32 value
)
2268 struct tun_struct
*tun
= netdev_priv(dev
);
2273 static const struct ethtool_ops tun_ethtool_ops
= {
2274 .get_settings
= tun_get_settings
,
2275 .get_drvinfo
= tun_get_drvinfo
,
2276 .get_msglevel
= tun_get_msglevel
,
2277 .set_msglevel
= tun_set_msglevel
,
2278 .get_link
= ethtool_op_get_link
,
2279 .get_ts_info
= ethtool_op_get_ts_info
,
2283 static int __init
tun_init(void)
2287 pr_info("%s, %s\n", DRV_DESCRIPTION
, DRV_VERSION
);
2288 pr_info("%s\n", DRV_COPYRIGHT
);
2290 ret
= rtnl_link_register(&tun_link_ops
);
2292 pr_err("Can't register link_ops\n");
2296 ret
= misc_register(&tun_miscdev
);
2298 pr_err("Can't register misc device %d\n", TUN_MINOR
);
2303 rtnl_link_unregister(&tun_link_ops
);
2308 static void tun_cleanup(void)
2310 misc_deregister(&tun_miscdev
);
2311 rtnl_link_unregister(&tun_link_ops
);
2314 /* Get an underlying socket object from tun file. Returns error unless file is
2315 * attached to a device. The returned object works like a packet socket, it
2316 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
2317 * holding a reference to the file for as long as the socket is in use. */
2318 struct socket
*tun_get_socket(struct file
*file
)
2320 struct tun_file
*tfile
;
2321 if (file
->f_op
!= &tun_fops
)
2322 return ERR_PTR(-EINVAL
);
2323 tfile
= file
->private_data
;
2325 return ERR_PTR(-EBADFD
);
2326 return &tfile
->socket
;
2328 EXPORT_SYMBOL_GPL(tun_get_socket
);
2330 module_init(tun_init
);
2331 module_exit(tun_cleanup
);
2332 MODULE_DESCRIPTION(DRV_DESCRIPTION
);
2333 MODULE_AUTHOR(DRV_COPYRIGHT
);
2334 MODULE_LICENSE("GPL");
2335 MODULE_ALIAS_MISCDEV(TUN_MINOR
);
2336 MODULE_ALIAS("devname:net/tun");