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>
72 #include <linux/seq_file.h>
73 #include <linux/uio.h>
75 #include <asm/uaccess.h>
77 /* Uncomment to enable debugging */
78 /* #define TUN_DEBUG 1 */
83 #define tun_debug(level, tun, fmt, args...) \
86 netdev_printk(level, tun->dev, fmt, ##args); \
88 #define DBG1(level, fmt, args...) \
91 printk(level fmt, ##args); \
94 #define tun_debug(level, tun, fmt, args...) \
97 netdev_printk(level, tun->dev, fmt, ##args); \
99 #define DBG1(level, fmt, args...) \
102 printk(level fmt, ##args); \
106 /* TUN device flags */
108 /* IFF_ATTACH_QUEUE is never stored in device flags,
109 * overload it to mean fasync when stored there.
111 #define TUN_FASYNC IFF_ATTACH_QUEUE
112 /* High bits in flags field are unused. */
113 #define TUN_VNET_LE 0x80000000
115 #define TUN_FEATURES (IFF_NO_PI | IFF_ONE_QUEUE | IFF_VNET_HDR | \
117 #define GOODCOPY_LEN 128
119 #define FLT_EXACT_COUNT 8
121 unsigned int count
; /* Number of addrs. Zero means disabled */
122 u32 mask
[2]; /* Mask of the hashed addrs */
123 unsigned char addr
[FLT_EXACT_COUNT
][ETH_ALEN
];
126 /* MAX_TAP_QUEUES 256 is chosen to allow rx/tx queues to be equal
127 * to max number of VCPUs in guest. */
128 #define MAX_TAP_QUEUES 256
129 #define MAX_TAP_FLOWS 4096
131 #define TUN_FLOW_EXPIRE (3 * HZ)
133 /* A tun_file connects an open character device to a tuntap netdevice. It
134 * also contains all socket related structures (except sock_fprog and tap_filter)
135 * to serve as one transmit queue for tuntap device. The sock_fprog and
136 * tap_filter were kept in tun_struct since they were used for filtering for the
137 * netdevice not for a specific queue (at least I didn't see the requirement for
141 * The tun_file and tun_struct are loosely coupled, the pointer from one to the
142 * other can only be read while rcu_read_lock or rtnl_lock is held.
146 struct socket socket
;
148 struct tun_struct __rcu
*tun
;
149 struct fasync_struct
*fasync
;
150 /* only used for fasnyc */
154 unsigned int ifindex
;
156 struct list_head next
;
157 struct tun_struct
*detached
;
160 struct tun_flow_entry
{
161 struct hlist_node hash_link
;
163 struct tun_struct
*tun
;
168 unsigned long updated
;
171 #define TUN_NUM_FLOW_ENTRIES 1024
173 /* Since the socket were moved to tun_file, to preserve the behavior of persist
174 * device, socket filter, sndbuf and vnet header size were restore when the
175 * file were attached to a persist device.
178 struct tun_file __rcu
*tfiles
[MAX_TAP_QUEUES
];
179 unsigned int numqueues
;
184 struct net_device
*dev
;
185 netdev_features_t set_features
;
186 #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \
187 NETIF_F_TSO6|NETIF_F_UFO)
191 struct tap_filter txflt
;
192 struct sock_fprog fprog
;
193 /* protected by rtnl lock */
194 bool filter_attached
;
199 struct hlist_head flows
[TUN_NUM_FLOW_ENTRIES
];
200 struct timer_list flow_gc_timer
;
201 unsigned long ageing_time
;
202 unsigned int numdisabled
;
203 struct list_head disabled
;
208 static inline u16
tun16_to_cpu(struct tun_struct
*tun
, __virtio16 val
)
210 return __virtio16_to_cpu(tun
->flags
& TUN_VNET_LE
, val
);
213 static inline __virtio16
cpu_to_tun16(struct tun_struct
*tun
, u16 val
)
215 return __cpu_to_virtio16(tun
->flags
& TUN_VNET_LE
, val
);
218 static inline u32
tun_hashfn(u32 rxhash
)
220 return rxhash
& 0x3ff;
223 static struct tun_flow_entry
*tun_flow_find(struct hlist_head
*head
, u32 rxhash
)
225 struct tun_flow_entry
*e
;
227 hlist_for_each_entry_rcu(e
, head
, hash_link
) {
228 if (e
->rxhash
== rxhash
)
234 static struct tun_flow_entry
*tun_flow_create(struct tun_struct
*tun
,
235 struct hlist_head
*head
,
236 u32 rxhash
, u16 queue_index
)
238 struct tun_flow_entry
*e
= kmalloc(sizeof(*e
), GFP_ATOMIC
);
241 tun_debug(KERN_INFO
, tun
, "create flow: hash %u index %u\n",
242 rxhash
, queue_index
);
243 e
->updated
= jiffies
;
246 e
->queue_index
= queue_index
;
248 hlist_add_head_rcu(&e
->hash_link
, head
);
254 static void tun_flow_delete(struct tun_struct
*tun
, struct tun_flow_entry
*e
)
256 tun_debug(KERN_INFO
, tun
, "delete flow: hash %u index %u\n",
257 e
->rxhash
, e
->queue_index
);
258 hlist_del_rcu(&e
->hash_link
);
263 static void tun_flow_flush(struct tun_struct
*tun
)
267 spin_lock_bh(&tun
->lock
);
268 for (i
= 0; i
< TUN_NUM_FLOW_ENTRIES
; i
++) {
269 struct tun_flow_entry
*e
;
270 struct hlist_node
*n
;
272 hlist_for_each_entry_safe(e
, n
, &tun
->flows
[i
], hash_link
)
273 tun_flow_delete(tun
, e
);
275 spin_unlock_bh(&tun
->lock
);
278 static void tun_flow_delete_by_queue(struct tun_struct
*tun
, u16 queue_index
)
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 if (e
->queue_index
== queue_index
)
289 tun_flow_delete(tun
, e
);
292 spin_unlock_bh(&tun
->lock
);
295 static void tun_flow_cleanup(unsigned long data
)
297 struct tun_struct
*tun
= (struct tun_struct
*)data
;
298 unsigned long delay
= tun
->ageing_time
;
299 unsigned long next_timer
= jiffies
+ delay
;
300 unsigned long count
= 0;
303 tun_debug(KERN_INFO
, tun
, "tun_flow_cleanup\n");
305 spin_lock_bh(&tun
->lock
);
306 for (i
= 0; i
< TUN_NUM_FLOW_ENTRIES
; i
++) {
307 struct tun_flow_entry
*e
;
308 struct hlist_node
*n
;
310 hlist_for_each_entry_safe(e
, n
, &tun
->flows
[i
], hash_link
) {
311 unsigned long this_timer
;
313 this_timer
= e
->updated
+ delay
;
314 if (time_before_eq(this_timer
, jiffies
))
315 tun_flow_delete(tun
, e
);
316 else if (time_before(this_timer
, next_timer
))
317 next_timer
= this_timer
;
322 mod_timer(&tun
->flow_gc_timer
, round_jiffies_up(next_timer
));
323 spin_unlock_bh(&tun
->lock
);
326 static void tun_flow_update(struct tun_struct
*tun
, u32 rxhash
,
327 struct tun_file
*tfile
)
329 struct hlist_head
*head
;
330 struct tun_flow_entry
*e
;
331 unsigned long delay
= tun
->ageing_time
;
332 u16 queue_index
= tfile
->queue_index
;
337 head
= &tun
->flows
[tun_hashfn(rxhash
)];
341 /* We may get a very small possibility of OOO during switching, not
342 * worth to optimize.*/
343 if (tun
->numqueues
== 1 || tfile
->detached
)
346 e
= tun_flow_find(head
, rxhash
);
348 /* TODO: keep queueing to old queue until it's empty? */
349 e
->queue_index
= queue_index
;
350 e
->updated
= jiffies
;
351 sock_rps_record_flow_hash(e
->rps_rxhash
);
353 spin_lock_bh(&tun
->lock
);
354 if (!tun_flow_find(head
, rxhash
) &&
355 tun
->flow_count
< MAX_TAP_FLOWS
)
356 tun_flow_create(tun
, head
, rxhash
, queue_index
);
358 if (!timer_pending(&tun
->flow_gc_timer
))
359 mod_timer(&tun
->flow_gc_timer
,
360 round_jiffies_up(jiffies
+ delay
));
361 spin_unlock_bh(&tun
->lock
);
369 * Save the hash received in the stack receive path and update the
370 * flow_hash table accordingly.
372 static inline void tun_flow_save_rps_rxhash(struct tun_flow_entry
*e
, u32 hash
)
374 if (unlikely(e
->rps_rxhash
!= hash
))
375 e
->rps_rxhash
= hash
;
378 /* We try to identify a flow through its rxhash first. The reason that
379 * we do not check rxq no. is because some cards(e.g 82599), chooses
380 * the rxq based on the txq where the last packet of the flow comes. As
381 * the userspace application move between processors, we may get a
382 * different rxq no. here. If we could not get rxhash, then we would
383 * hope the rxq no. may help here.
385 static u16
tun_select_queue(struct net_device
*dev
, struct sk_buff
*skb
,
386 void *accel_priv
, select_queue_fallback_t fallback
)
388 struct tun_struct
*tun
= netdev_priv(dev
);
389 struct tun_flow_entry
*e
;
394 numqueues
= ACCESS_ONCE(tun
->numqueues
);
396 txq
= skb_get_hash(skb
);
398 e
= tun_flow_find(&tun
->flows
[tun_hashfn(txq
)], txq
);
400 tun_flow_save_rps_rxhash(e
, txq
);
401 txq
= e
->queue_index
;
403 /* use multiply and shift instead of expensive divide */
404 txq
= ((u64
)txq
* numqueues
) >> 32;
405 } else if (likely(skb_rx_queue_recorded(skb
))) {
406 txq
= skb_get_rx_queue(skb
);
407 while (unlikely(txq
>= numqueues
))
415 static inline bool tun_not_capable(struct tun_struct
*tun
)
417 const struct cred
*cred
= current_cred();
418 struct net
*net
= dev_net(tun
->dev
);
420 return ((uid_valid(tun
->owner
) && !uid_eq(cred
->euid
, tun
->owner
)) ||
421 (gid_valid(tun
->group
) && !in_egroup_p(tun
->group
))) &&
422 !ns_capable(net
->user_ns
, CAP_NET_ADMIN
);
425 static void tun_set_real_num_queues(struct tun_struct
*tun
)
427 netif_set_real_num_tx_queues(tun
->dev
, tun
->numqueues
);
428 netif_set_real_num_rx_queues(tun
->dev
, tun
->numqueues
);
431 static void tun_disable_queue(struct tun_struct
*tun
, struct tun_file
*tfile
)
433 tfile
->detached
= tun
;
434 list_add_tail(&tfile
->next
, &tun
->disabled
);
438 static struct tun_struct
*tun_enable_queue(struct tun_file
*tfile
)
440 struct tun_struct
*tun
= tfile
->detached
;
442 tfile
->detached
= NULL
;
443 list_del_init(&tfile
->next
);
448 static void tun_queue_purge(struct tun_file
*tfile
)
450 skb_queue_purge(&tfile
->sk
.sk_receive_queue
);
451 skb_queue_purge(&tfile
->sk
.sk_error_queue
);
454 static void __tun_detach(struct tun_file
*tfile
, bool clean
)
456 struct tun_file
*ntfile
;
457 struct tun_struct
*tun
;
459 tun
= rtnl_dereference(tfile
->tun
);
461 if (tun
&& !tfile
->detached
) {
462 u16 index
= tfile
->queue_index
;
463 BUG_ON(index
>= tun
->numqueues
);
465 rcu_assign_pointer(tun
->tfiles
[index
],
466 tun
->tfiles
[tun
->numqueues
- 1]);
467 ntfile
= rtnl_dereference(tun
->tfiles
[index
]);
468 ntfile
->queue_index
= index
;
472 RCU_INIT_POINTER(tfile
->tun
, NULL
);
473 sock_put(&tfile
->sk
);
475 tun_disable_queue(tun
, tfile
);
478 tun_flow_delete_by_queue(tun
, tun
->numqueues
+ 1);
479 /* Drop read queue */
480 tun_queue_purge(tfile
);
481 tun_set_real_num_queues(tun
);
482 } else if (tfile
->detached
&& clean
) {
483 tun
= tun_enable_queue(tfile
);
484 sock_put(&tfile
->sk
);
488 if (tun
&& tun
->numqueues
== 0 && tun
->numdisabled
== 0) {
489 netif_carrier_off(tun
->dev
);
491 if (!(tun
->flags
& IFF_PERSIST
) &&
492 tun
->dev
->reg_state
== NETREG_REGISTERED
)
493 unregister_netdevice(tun
->dev
);
495 sock_put(&tfile
->sk
);
499 static void tun_detach(struct tun_file
*tfile
, bool clean
)
502 __tun_detach(tfile
, clean
);
506 static void tun_detach_all(struct net_device
*dev
)
508 struct tun_struct
*tun
= netdev_priv(dev
);
509 struct tun_file
*tfile
, *tmp
;
510 int i
, n
= tun
->numqueues
;
512 for (i
= 0; i
< n
; i
++) {
513 tfile
= rtnl_dereference(tun
->tfiles
[i
]);
515 tfile
->socket
.sk
->sk_data_ready(tfile
->socket
.sk
);
516 RCU_INIT_POINTER(tfile
->tun
, NULL
);
519 list_for_each_entry(tfile
, &tun
->disabled
, next
) {
520 tfile
->socket
.sk
->sk_data_ready(tfile
->socket
.sk
);
521 RCU_INIT_POINTER(tfile
->tun
, NULL
);
523 BUG_ON(tun
->numqueues
!= 0);
526 for (i
= 0; i
< n
; i
++) {
527 tfile
= rtnl_dereference(tun
->tfiles
[i
]);
528 /* Drop read queue */
529 tun_queue_purge(tfile
);
530 sock_put(&tfile
->sk
);
532 list_for_each_entry_safe(tfile
, tmp
, &tun
->disabled
, next
) {
533 tun_enable_queue(tfile
);
534 tun_queue_purge(tfile
);
535 sock_put(&tfile
->sk
);
537 BUG_ON(tun
->numdisabled
!= 0);
539 if (tun
->flags
& IFF_PERSIST
)
540 module_put(THIS_MODULE
);
543 static int tun_attach(struct tun_struct
*tun
, struct file
*file
, bool skip_filter
)
545 struct tun_file
*tfile
= file
->private_data
;
548 err
= security_tun_dev_attach(tfile
->socket
.sk
, tun
->security
);
553 if (rtnl_dereference(tfile
->tun
) && !tfile
->detached
)
557 if (!(tun
->flags
& IFF_MULTI_QUEUE
) && tun
->numqueues
== 1)
561 if (!tfile
->detached
&&
562 tun
->numqueues
+ tun
->numdisabled
== MAX_TAP_QUEUES
)
567 /* Re-attach the filter to persist device */
568 if (!skip_filter
&& (tun
->filter_attached
== true)) {
569 err
= sk_attach_filter(&tun
->fprog
, tfile
->socket
.sk
);
573 tfile
->queue_index
= tun
->numqueues
;
574 rcu_assign_pointer(tfile
->tun
, tun
);
575 rcu_assign_pointer(tun
->tfiles
[tun
->numqueues
], tfile
);
579 tun_enable_queue(tfile
);
581 sock_hold(&tfile
->sk
);
583 tun_set_real_num_queues(tun
);
585 /* device is allowed to go away first, so no need to hold extra
593 static struct tun_struct
*__tun_get(struct tun_file
*tfile
)
595 struct tun_struct
*tun
;
598 tun
= rcu_dereference(tfile
->tun
);
606 static struct tun_struct
*tun_get(struct file
*file
)
608 return __tun_get(file
->private_data
);
611 static void tun_put(struct tun_struct
*tun
)
617 static void addr_hash_set(u32
*mask
, const u8
*addr
)
619 int n
= ether_crc(ETH_ALEN
, addr
) >> 26;
620 mask
[n
>> 5] |= (1 << (n
& 31));
623 static unsigned int addr_hash_test(const u32
*mask
, const u8
*addr
)
625 int n
= ether_crc(ETH_ALEN
, addr
) >> 26;
626 return mask
[n
>> 5] & (1 << (n
& 31));
629 static int update_filter(struct tap_filter
*filter
, void __user
*arg
)
631 struct { u8 u
[ETH_ALEN
]; } *addr
;
632 struct tun_filter uf
;
633 int err
, alen
, n
, nexact
;
635 if (copy_from_user(&uf
, arg
, sizeof(uf
)))
644 alen
= ETH_ALEN
* uf
.count
;
645 addr
= kmalloc(alen
, GFP_KERNEL
);
649 if (copy_from_user(addr
, arg
+ sizeof(uf
), alen
)) {
654 /* The filter is updated without holding any locks. Which is
655 * perfectly safe. We disable it first and in the worst
656 * case we'll accept a few undesired packets. */
660 /* Use first set of addresses as an exact filter */
661 for (n
= 0; n
< uf
.count
&& n
< FLT_EXACT_COUNT
; n
++)
662 memcpy(filter
->addr
[n
], addr
[n
].u
, ETH_ALEN
);
666 /* Remaining multicast addresses are hashed,
667 * unicast will leave the filter disabled. */
668 memset(filter
->mask
, 0, sizeof(filter
->mask
));
669 for (; n
< uf
.count
; n
++) {
670 if (!is_multicast_ether_addr(addr
[n
].u
)) {
671 err
= 0; /* no filter */
674 addr_hash_set(filter
->mask
, addr
[n
].u
);
677 /* For ALLMULTI just set the mask to all ones.
678 * This overrides the mask populated above. */
679 if ((uf
.flags
& TUN_FLT_ALLMULTI
))
680 memset(filter
->mask
, ~0, sizeof(filter
->mask
));
682 /* Now enable the filter */
684 filter
->count
= nexact
;
686 /* Return the number of exact filters */
694 /* Returns: 0 - drop, !=0 - accept */
695 static int run_filter(struct tap_filter
*filter
, const struct sk_buff
*skb
)
697 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
699 struct ethhdr
*eh
= (struct ethhdr
*) skb
->data
;
703 for (i
= 0; i
< filter
->count
; i
++)
704 if (ether_addr_equal(eh
->h_dest
, filter
->addr
[i
]))
707 /* Inexact match (multicast only) */
708 if (is_multicast_ether_addr(eh
->h_dest
))
709 return addr_hash_test(filter
->mask
, eh
->h_dest
);
715 * Checks whether the packet is accepted or not.
716 * Returns: 0 - drop, !=0 - accept
718 static int check_filter(struct tap_filter
*filter
, const struct sk_buff
*skb
)
723 return run_filter(filter
, skb
);
726 /* Network device part of the driver */
728 static const struct ethtool_ops tun_ethtool_ops
;
730 /* Net device detach from fd. */
731 static void tun_net_uninit(struct net_device
*dev
)
736 /* Net device open. */
737 static int tun_net_open(struct net_device
*dev
)
739 netif_tx_start_all_queues(dev
);
743 /* Net device close. */
744 static int tun_net_close(struct net_device
*dev
)
746 netif_tx_stop_all_queues(dev
);
750 /* Net device start xmit */
751 static netdev_tx_t
tun_net_xmit(struct sk_buff
*skb
, struct net_device
*dev
)
753 struct tun_struct
*tun
= netdev_priv(dev
);
754 int txq
= skb
->queue_mapping
;
755 struct tun_file
*tfile
;
759 tfile
= rcu_dereference(tun
->tfiles
[txq
]);
760 numqueues
= ACCESS_ONCE(tun
->numqueues
);
762 /* Drop packet if interface is not attached */
763 if (txq
>= numqueues
)
766 if (numqueues
== 1) {
767 /* Select queue was not called for the skbuff, so we extract the
768 * RPS hash and save it into the flow_table here.
772 rxhash
= skb_get_hash(skb
);
774 struct tun_flow_entry
*e
;
775 e
= tun_flow_find(&tun
->flows
[tun_hashfn(rxhash
)],
778 tun_flow_save_rps_rxhash(e
, rxhash
);
782 tun_debug(KERN_INFO
, tun
, "tun_net_xmit %d\n", skb
->len
);
786 /* Drop if the filter does not like it.
787 * This is a noop if the filter is disabled.
788 * Filter can be enabled only for the TAP devices. */
789 if (!check_filter(&tun
->txflt
, skb
))
792 if (tfile
->socket
.sk
->sk_filter
&&
793 sk_filter(tfile
->socket
.sk
, skb
))
796 /* Limit the number of packets queued by dividing txq length with the
799 if (skb_queue_len(&tfile
->socket
.sk
->sk_receive_queue
) * numqueues
800 >= dev
->tx_queue_len
)
803 if (unlikely(skb_orphan_frags(skb
, GFP_ATOMIC
)))
807 sock_tx_timestamp(skb
->sk
, &skb_shinfo(skb
)->tx_flags
);
808 sw_tx_timestamp(skb
);
811 /* Orphan the skb - required as we might hang on to it
812 * for indefinite time.
819 skb_queue_tail(&tfile
->socket
.sk
->sk_receive_queue
, skb
);
821 /* Notify and wake up reader process */
822 if (tfile
->flags
& TUN_FASYNC
)
823 kill_fasync(&tfile
->fasync
, SIGIO
, POLL_IN
);
824 tfile
->socket
.sk
->sk_data_ready(tfile
->socket
.sk
);
830 dev
->stats
.tx_dropped
++;
834 return NET_XMIT_DROP
;
837 static void tun_net_mclist(struct net_device
*dev
)
840 * This callback is supposed to deal with mc filter in
841 * _rx_ path and has nothing to do with the _tx_ path.
842 * In rx path we always accept everything userspace gives us.
847 #define MAX_MTU 65535
850 tun_net_change_mtu(struct net_device
*dev
, int new_mtu
)
852 if (new_mtu
< MIN_MTU
|| new_mtu
+ dev
->hard_header_len
> MAX_MTU
)
858 static netdev_features_t
tun_net_fix_features(struct net_device
*dev
,
859 netdev_features_t features
)
861 struct tun_struct
*tun
= netdev_priv(dev
);
863 return (features
& tun
->set_features
) | (features
& ~TUN_USER_FEATURES
);
865 #ifdef CONFIG_NET_POLL_CONTROLLER
866 static void tun_poll_controller(struct net_device
*dev
)
869 * Tun only receives frames when:
870 * 1) the char device endpoint gets data from user space
871 * 2) the tun socket gets a sendmsg call from user space
872 * Since both of those are synchronous operations, we are guaranteed
873 * never to have pending data when we poll for it
874 * so there is nothing to do here but return.
875 * We need this though so netpoll recognizes us as an interface that
876 * supports polling, which enables bridge devices in virt setups to
877 * still use netconsole
882 static const struct net_device_ops tun_netdev_ops
= {
883 .ndo_uninit
= tun_net_uninit
,
884 .ndo_open
= tun_net_open
,
885 .ndo_stop
= tun_net_close
,
886 .ndo_start_xmit
= tun_net_xmit
,
887 .ndo_change_mtu
= tun_net_change_mtu
,
888 .ndo_fix_features
= tun_net_fix_features
,
889 .ndo_select_queue
= tun_select_queue
,
890 #ifdef CONFIG_NET_POLL_CONTROLLER
891 .ndo_poll_controller
= tun_poll_controller
,
895 static const struct net_device_ops tap_netdev_ops
= {
896 .ndo_uninit
= tun_net_uninit
,
897 .ndo_open
= tun_net_open
,
898 .ndo_stop
= tun_net_close
,
899 .ndo_start_xmit
= tun_net_xmit
,
900 .ndo_change_mtu
= tun_net_change_mtu
,
901 .ndo_fix_features
= tun_net_fix_features
,
902 .ndo_set_rx_mode
= tun_net_mclist
,
903 .ndo_set_mac_address
= eth_mac_addr
,
904 .ndo_validate_addr
= eth_validate_addr
,
905 .ndo_select_queue
= tun_select_queue
,
906 #ifdef CONFIG_NET_POLL_CONTROLLER
907 .ndo_poll_controller
= tun_poll_controller
,
911 static void tun_flow_init(struct tun_struct
*tun
)
915 for (i
= 0; i
< TUN_NUM_FLOW_ENTRIES
; i
++)
916 INIT_HLIST_HEAD(&tun
->flows
[i
]);
918 tun
->ageing_time
= TUN_FLOW_EXPIRE
;
919 setup_timer(&tun
->flow_gc_timer
, tun_flow_cleanup
, (unsigned long)tun
);
920 mod_timer(&tun
->flow_gc_timer
,
921 round_jiffies_up(jiffies
+ tun
->ageing_time
));
924 static void tun_flow_uninit(struct tun_struct
*tun
)
926 del_timer_sync(&tun
->flow_gc_timer
);
930 /* Initialize net device. */
931 static void tun_net_init(struct net_device
*dev
)
933 struct tun_struct
*tun
= netdev_priv(dev
);
935 switch (tun
->flags
& TUN_TYPE_MASK
) {
937 dev
->netdev_ops
= &tun_netdev_ops
;
939 /* Point-to-Point TUN Device */
940 dev
->hard_header_len
= 0;
944 /* Zero header length */
945 dev
->type
= ARPHRD_NONE
;
946 dev
->flags
= IFF_POINTOPOINT
| IFF_NOARP
| IFF_MULTICAST
;
947 dev
->tx_queue_len
= TUN_READQ_SIZE
; /* We prefer our own queue length */
951 dev
->netdev_ops
= &tap_netdev_ops
;
952 /* Ethernet TAP Device */
954 dev
->priv_flags
&= ~IFF_TX_SKB_SHARING
;
955 dev
->priv_flags
|= IFF_LIVE_ADDR_CHANGE
;
957 eth_hw_addr_random(dev
);
959 dev
->tx_queue_len
= TUN_READQ_SIZE
; /* We prefer our own queue length */
964 /* Character device part */
967 static unsigned int tun_chr_poll(struct file
*file
, poll_table
*wait
)
969 struct tun_file
*tfile
= file
->private_data
;
970 struct tun_struct
*tun
= __tun_get(tfile
);
972 unsigned int mask
= 0;
977 sk
= tfile
->socket
.sk
;
979 tun_debug(KERN_INFO
, tun
, "tun_chr_poll\n");
981 poll_wait(file
, sk_sleep(sk
), wait
);
983 if (!skb_queue_empty(&sk
->sk_receive_queue
))
984 mask
|= POLLIN
| POLLRDNORM
;
986 if (sock_writeable(sk
) ||
987 (!test_and_set_bit(SOCK_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
) &&
989 mask
|= POLLOUT
| POLLWRNORM
;
991 if (tun
->dev
->reg_state
!= NETREG_REGISTERED
)
998 /* prepad is the amount to reserve at front. len is length after that.
999 * linear is a hint as to how much to copy (usually headers). */
1000 static struct sk_buff
*tun_alloc_skb(struct tun_file
*tfile
,
1001 size_t prepad
, size_t len
,
1002 size_t linear
, int noblock
)
1004 struct sock
*sk
= tfile
->socket
.sk
;
1005 struct sk_buff
*skb
;
1008 /* Under a page? Don't bother with paged skb. */
1009 if (prepad
+ len
< PAGE_SIZE
|| !linear
)
1012 skb
= sock_alloc_send_pskb(sk
, prepad
+ linear
, len
- linear
, noblock
,
1015 return ERR_PTR(err
);
1017 skb_reserve(skb
, prepad
);
1018 skb_put(skb
, linear
);
1019 skb
->data_len
= len
- linear
;
1020 skb
->len
+= len
- linear
;
1025 /* Get packet from user space buffer */
1026 static ssize_t
tun_get_user(struct tun_struct
*tun
, struct tun_file
*tfile
,
1027 void *msg_control
, struct iov_iter
*from
,
1030 struct tun_pi pi
= { 0, cpu_to_be16(ETH_P_IP
) };
1031 struct sk_buff
*skb
;
1032 size_t total_len
= iov_iter_count(from
);
1033 size_t len
= total_len
, align
= NET_SKB_PAD
, linear
;
1034 struct virtio_net_hdr gso
= { 0 };
1037 bool zerocopy
= false;
1042 if (!(tun
->flags
& IFF_NO_PI
)) {
1043 if (len
< sizeof(pi
))
1047 n
= copy_from_iter(&pi
, sizeof(pi
), from
);
1048 if (n
!= sizeof(pi
))
1052 if (tun
->flags
& IFF_VNET_HDR
) {
1053 if (len
< tun
->vnet_hdr_sz
)
1055 len
-= tun
->vnet_hdr_sz
;
1057 n
= copy_from_iter(&gso
, sizeof(gso
), from
);
1058 if (n
!= sizeof(gso
))
1061 if ((gso
.flags
& VIRTIO_NET_HDR_F_NEEDS_CSUM
) &&
1062 tun16_to_cpu(tun
, gso
.csum_start
) + tun16_to_cpu(tun
, gso
.csum_offset
) + 2 > tun16_to_cpu(tun
, gso
.hdr_len
))
1063 gso
.hdr_len
= cpu_to_tun16(tun
, tun16_to_cpu(tun
, gso
.csum_start
) + tun16_to_cpu(tun
, gso
.csum_offset
) + 2);
1065 if (tun16_to_cpu(tun
, gso
.hdr_len
) > len
)
1067 iov_iter_advance(from
, tun
->vnet_hdr_sz
- sizeof(gso
));
1070 if ((tun
->flags
& TUN_TYPE_MASK
) == IFF_TAP
) {
1071 align
+= NET_IP_ALIGN
;
1072 if (unlikely(len
< ETH_HLEN
||
1073 (gso
.hdr_len
&& tun16_to_cpu(tun
, gso
.hdr_len
) < ETH_HLEN
)))
1077 good_linear
= SKB_MAX_HEAD(align
);
1080 struct iov_iter i
= *from
;
1082 /* There are 256 bytes to be copied in skb, so there is
1083 * enough room for skb expand head in case it is used.
1084 * The rest of the buffer is mapped from userspace.
1086 copylen
= gso
.hdr_len
? tun16_to_cpu(tun
, gso
.hdr_len
) : GOODCOPY_LEN
;
1087 if (copylen
> good_linear
)
1088 copylen
= good_linear
;
1090 iov_iter_advance(&i
, copylen
);
1091 if (iov_iter_npages(&i
, INT_MAX
) <= MAX_SKB_FRAGS
)
1097 if (tun16_to_cpu(tun
, gso
.hdr_len
) > good_linear
)
1098 linear
= good_linear
;
1100 linear
= tun16_to_cpu(tun
, gso
.hdr_len
);
1103 skb
= tun_alloc_skb(tfile
, align
, copylen
, linear
, noblock
);
1105 if (PTR_ERR(skb
) != -EAGAIN
)
1106 tun
->dev
->stats
.rx_dropped
++;
1107 return PTR_ERR(skb
);
1111 err
= zerocopy_sg_from_iter(skb
, from
);
1113 err
= skb_copy_datagram_from_iter(skb
, 0, from
, len
);
1114 if (!err
&& msg_control
) {
1115 struct ubuf_info
*uarg
= msg_control
;
1116 uarg
->callback(uarg
, false);
1121 tun
->dev
->stats
.rx_dropped
++;
1126 if (gso
.flags
& VIRTIO_NET_HDR_F_NEEDS_CSUM
) {
1127 if (!skb_partial_csum_set(skb
, tun16_to_cpu(tun
, gso
.csum_start
),
1128 tun16_to_cpu(tun
, gso
.csum_offset
))) {
1129 tun
->dev
->stats
.rx_frame_errors
++;
1135 switch (tun
->flags
& TUN_TYPE_MASK
) {
1137 if (tun
->flags
& IFF_NO_PI
) {
1138 switch (skb
->data
[0] & 0xf0) {
1140 pi
.proto
= htons(ETH_P_IP
);
1143 pi
.proto
= htons(ETH_P_IPV6
);
1146 tun
->dev
->stats
.rx_dropped
++;
1152 skb_reset_mac_header(skb
);
1153 skb
->protocol
= pi
.proto
;
1154 skb
->dev
= tun
->dev
;
1157 skb
->protocol
= eth_type_trans(skb
, tun
->dev
);
1161 if (gso
.gso_type
!= VIRTIO_NET_HDR_GSO_NONE
) {
1163 switch (gso
.gso_type
& ~VIRTIO_NET_HDR_GSO_ECN
) {
1164 case VIRTIO_NET_HDR_GSO_TCPV4
:
1165 skb_shinfo(skb
)->gso_type
= SKB_GSO_TCPV4
;
1167 case VIRTIO_NET_HDR_GSO_TCPV6
:
1168 skb_shinfo(skb
)->gso_type
= SKB_GSO_TCPV6
;
1170 case VIRTIO_NET_HDR_GSO_UDP
:
1171 skb_shinfo(skb
)->gso_type
= SKB_GSO_UDP
;
1174 tun
->dev
->stats
.rx_frame_errors
++;
1179 if (gso
.gso_type
& VIRTIO_NET_HDR_GSO_ECN
)
1180 skb_shinfo(skb
)->gso_type
|= SKB_GSO_TCP_ECN
;
1182 skb_shinfo(skb
)->gso_size
= tun16_to_cpu(tun
, gso
.gso_size
);
1183 if (skb_shinfo(skb
)->gso_size
== 0) {
1184 tun
->dev
->stats
.rx_frame_errors
++;
1189 /* Header must be checked, and gso_segs computed. */
1190 skb_shinfo(skb
)->gso_type
|= SKB_GSO_DODGY
;
1191 skb_shinfo(skb
)->gso_segs
= 0;
1194 /* copy skb_ubuf_info for callback when skb has no error */
1196 skb_shinfo(skb
)->destructor_arg
= msg_control
;
1197 skb_shinfo(skb
)->tx_flags
|= SKBTX_DEV_ZEROCOPY
;
1198 skb_shinfo(skb
)->tx_flags
|= SKBTX_SHARED_FRAG
;
1201 skb_reset_network_header(skb
);
1202 skb_probe_transport_header(skb
, 0);
1204 rxhash
= skb_get_hash(skb
);
1207 tun
->dev
->stats
.rx_packets
++;
1208 tun
->dev
->stats
.rx_bytes
+= len
;
1210 tun_flow_update(tun
, rxhash
, tfile
);
1214 static ssize_t
tun_chr_write_iter(struct kiocb
*iocb
, struct iov_iter
*from
)
1216 struct file
*file
= iocb
->ki_filp
;
1217 struct tun_struct
*tun
= tun_get(file
);
1218 struct tun_file
*tfile
= file
->private_data
;
1224 result
= tun_get_user(tun
, tfile
, NULL
, from
, file
->f_flags
& O_NONBLOCK
);
1230 /* Put packet to the user space buffer */
1231 static ssize_t
tun_put_user(struct tun_struct
*tun
,
1232 struct tun_file
*tfile
,
1233 struct sk_buff
*skb
,
1234 struct iov_iter
*iter
)
1236 struct tun_pi pi
= { 0, skb
->protocol
};
1238 int vlan_offset
= 0;
1240 int vnet_hdr_sz
= 0;
1242 if (skb_vlan_tag_present(skb
))
1243 vlan_hlen
= VLAN_HLEN
;
1245 if (tun
->flags
& IFF_VNET_HDR
)
1246 vnet_hdr_sz
= tun
->vnet_hdr_sz
;
1248 total
= skb
->len
+ vlan_hlen
+ vnet_hdr_sz
;
1250 if (!(tun
->flags
& IFF_NO_PI
)) {
1251 if (iov_iter_count(iter
) < sizeof(pi
))
1254 total
+= sizeof(pi
);
1255 if (iov_iter_count(iter
) < total
) {
1256 /* Packet will be striped */
1257 pi
.flags
|= TUN_PKT_STRIP
;
1260 if (copy_to_iter(&pi
, sizeof(pi
), iter
) != sizeof(pi
))
1265 struct virtio_net_hdr gso
= { 0 }; /* no info leak */
1266 if (iov_iter_count(iter
) < vnet_hdr_sz
)
1269 if (skb_is_gso(skb
)) {
1270 struct skb_shared_info
*sinfo
= skb_shinfo(skb
);
1272 /* This is a hint as to how much should be linear. */
1273 gso
.hdr_len
= cpu_to_tun16(tun
, skb_headlen(skb
));
1274 gso
.gso_size
= cpu_to_tun16(tun
, sinfo
->gso_size
);
1275 if (sinfo
->gso_type
& SKB_GSO_TCPV4
)
1276 gso
.gso_type
= VIRTIO_NET_HDR_GSO_TCPV4
;
1277 else if (sinfo
->gso_type
& SKB_GSO_TCPV6
)
1278 gso
.gso_type
= VIRTIO_NET_HDR_GSO_TCPV6
;
1279 else if (sinfo
->gso_type
& SKB_GSO_UDP
)
1280 gso
.gso_type
= VIRTIO_NET_HDR_GSO_UDP
;
1282 pr_err("unexpected GSO type: "
1283 "0x%x, gso_size %d, hdr_len %d\n",
1284 sinfo
->gso_type
, tun16_to_cpu(tun
, gso
.gso_size
),
1285 tun16_to_cpu(tun
, gso
.hdr_len
));
1286 print_hex_dump(KERN_ERR
, "tun: ",
1289 min((int)tun16_to_cpu(tun
, gso
.hdr_len
), 64), true);
1293 if (sinfo
->gso_type
& SKB_GSO_TCP_ECN
)
1294 gso
.gso_type
|= VIRTIO_NET_HDR_GSO_ECN
;
1296 gso
.gso_type
= VIRTIO_NET_HDR_GSO_NONE
;
1298 if (skb
->ip_summed
== CHECKSUM_PARTIAL
) {
1299 gso
.flags
= VIRTIO_NET_HDR_F_NEEDS_CSUM
;
1300 gso
.csum_start
= cpu_to_tun16(tun
, skb_checksum_start_offset(skb
) +
1302 gso
.csum_offset
= cpu_to_tun16(tun
, skb
->csum_offset
);
1303 } else if (skb
->ip_summed
== CHECKSUM_UNNECESSARY
) {
1304 gso
.flags
= VIRTIO_NET_HDR_F_DATA_VALID
;
1305 } /* else everything is zero */
1307 if (copy_to_iter(&gso
, sizeof(gso
), iter
) != sizeof(gso
))
1310 iov_iter_advance(iter
, vnet_hdr_sz
- sizeof(gso
));
1316 __be16 h_vlan_proto
;
1320 veth
.h_vlan_proto
= skb
->vlan_proto
;
1321 veth
.h_vlan_TCI
= htons(skb_vlan_tag_get(skb
));
1323 vlan_offset
= offsetof(struct vlan_ethhdr
, h_vlan_proto
);
1325 ret
= skb_copy_datagram_iter(skb
, 0, iter
, vlan_offset
);
1326 if (ret
|| !iov_iter_count(iter
))
1329 ret
= copy_to_iter(&veth
, sizeof(veth
), iter
);
1330 if (ret
!= sizeof(veth
) || !iov_iter_count(iter
))
1334 skb_copy_datagram_iter(skb
, vlan_offset
, iter
, skb
->len
- vlan_offset
);
1337 tun
->dev
->stats
.tx_packets
++;
1338 tun
->dev
->stats
.tx_bytes
+= skb
->len
+ vlan_hlen
;
1343 static ssize_t
tun_do_read(struct tun_struct
*tun
, struct tun_file
*tfile
,
1344 struct iov_iter
*to
,
1347 struct sk_buff
*skb
;
1349 int peeked
, err
, off
= 0;
1351 tun_debug(KERN_INFO
, tun
, "tun_do_read\n");
1353 if (!iov_iter_count(to
))
1356 if (tun
->dev
->reg_state
!= NETREG_REGISTERED
)
1359 /* Read frames from queue */
1360 skb
= __skb_recv_datagram(tfile
->socket
.sk
, noblock
? MSG_DONTWAIT
: 0,
1361 &peeked
, &off
, &err
);
1365 ret
= tun_put_user(tun
, tfile
, skb
, to
);
1366 if (unlikely(ret
< 0))
1374 static ssize_t
tun_chr_read_iter(struct kiocb
*iocb
, struct iov_iter
*to
)
1376 struct file
*file
= iocb
->ki_filp
;
1377 struct tun_file
*tfile
= file
->private_data
;
1378 struct tun_struct
*tun
= __tun_get(tfile
);
1379 ssize_t len
= iov_iter_count(to
), ret
;
1383 ret
= tun_do_read(tun
, tfile
, to
, file
->f_flags
& O_NONBLOCK
);
1384 ret
= min_t(ssize_t
, ret
, len
);
1391 static void tun_free_netdev(struct net_device
*dev
)
1393 struct tun_struct
*tun
= netdev_priv(dev
);
1395 BUG_ON(!(list_empty(&tun
->disabled
)));
1396 tun_flow_uninit(tun
);
1397 security_tun_dev_free_security(tun
->security
);
1401 static void tun_setup(struct net_device
*dev
)
1403 struct tun_struct
*tun
= netdev_priv(dev
);
1405 tun
->owner
= INVALID_UID
;
1406 tun
->group
= INVALID_GID
;
1408 dev
->ethtool_ops
= &tun_ethtool_ops
;
1409 dev
->destructor
= tun_free_netdev
;
1412 /* Trivial set of netlink ops to allow deleting tun or tap
1413 * device with netlink.
1415 static int tun_validate(struct nlattr
*tb
[], struct nlattr
*data
[])
1420 static struct rtnl_link_ops tun_link_ops __read_mostly
= {
1422 .priv_size
= sizeof(struct tun_struct
),
1424 .validate
= tun_validate
,
1427 static void tun_sock_write_space(struct sock
*sk
)
1429 struct tun_file
*tfile
;
1430 wait_queue_head_t
*wqueue
;
1432 if (!sock_writeable(sk
))
1435 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
))
1438 wqueue
= sk_sleep(sk
);
1439 if (wqueue
&& waitqueue_active(wqueue
))
1440 wake_up_interruptible_sync_poll(wqueue
, POLLOUT
|
1441 POLLWRNORM
| POLLWRBAND
);
1443 tfile
= container_of(sk
, struct tun_file
, sk
);
1444 kill_fasync(&tfile
->fasync
, SIGIO
, POLL_OUT
);
1447 static int tun_sendmsg(struct socket
*sock
, struct msghdr
*m
, size_t total_len
)
1450 struct tun_file
*tfile
= container_of(sock
, struct tun_file
, socket
);
1451 struct tun_struct
*tun
= __tun_get(tfile
);
1456 ret
= tun_get_user(tun
, tfile
, m
->msg_control
, &m
->msg_iter
,
1457 m
->msg_flags
& MSG_DONTWAIT
);
1462 static int tun_recvmsg(struct socket
*sock
, struct msghdr
*m
, size_t total_len
,
1465 struct tun_file
*tfile
= container_of(sock
, struct tun_file
, socket
);
1466 struct tun_struct
*tun
= __tun_get(tfile
);
1472 if (flags
& ~(MSG_DONTWAIT
|MSG_TRUNC
|MSG_ERRQUEUE
)) {
1476 if (flags
& MSG_ERRQUEUE
) {
1477 ret
= sock_recv_errqueue(sock
->sk
, m
, total_len
,
1478 SOL_PACKET
, TUN_TX_TIMESTAMP
);
1481 ret
= tun_do_read(tun
, tfile
, &m
->msg_iter
, flags
& MSG_DONTWAIT
);
1482 if (ret
> (ssize_t
)total_len
) {
1483 m
->msg_flags
|= MSG_TRUNC
;
1484 ret
= flags
& MSG_TRUNC
? ret
: total_len
;
1491 /* Ops structure to mimic raw sockets with tun */
1492 static const struct proto_ops tun_socket_ops
= {
1493 .sendmsg
= tun_sendmsg
,
1494 .recvmsg
= tun_recvmsg
,
1497 static struct proto tun_proto
= {
1499 .owner
= THIS_MODULE
,
1500 .obj_size
= sizeof(struct tun_file
),
1503 static int tun_flags(struct tun_struct
*tun
)
1505 return tun
->flags
& (TUN_FEATURES
| IFF_PERSIST
| IFF_TUN
| IFF_TAP
);
1508 static ssize_t
tun_show_flags(struct device
*dev
, struct device_attribute
*attr
,
1511 struct tun_struct
*tun
= netdev_priv(to_net_dev(dev
));
1512 return sprintf(buf
, "0x%x\n", tun_flags(tun
));
1515 static ssize_t
tun_show_owner(struct device
*dev
, struct device_attribute
*attr
,
1518 struct tun_struct
*tun
= netdev_priv(to_net_dev(dev
));
1519 return uid_valid(tun
->owner
)?
1520 sprintf(buf
, "%u\n",
1521 from_kuid_munged(current_user_ns(), tun
->owner
)):
1522 sprintf(buf
, "-1\n");
1525 static ssize_t
tun_show_group(struct device
*dev
, struct device_attribute
*attr
,
1528 struct tun_struct
*tun
= netdev_priv(to_net_dev(dev
));
1529 return gid_valid(tun
->group
) ?
1530 sprintf(buf
, "%u\n",
1531 from_kgid_munged(current_user_ns(), tun
->group
)):
1532 sprintf(buf
, "-1\n");
1535 static DEVICE_ATTR(tun_flags
, 0444, tun_show_flags
, NULL
);
1536 static DEVICE_ATTR(owner
, 0444, tun_show_owner
, NULL
);
1537 static DEVICE_ATTR(group
, 0444, tun_show_group
, NULL
);
1539 static struct attribute
*tun_dev_attrs
[] = {
1540 &dev_attr_tun_flags
.attr
,
1541 &dev_attr_owner
.attr
,
1542 &dev_attr_group
.attr
,
1546 static const struct attribute_group tun_attr_group
= {
1547 .attrs
= tun_dev_attrs
1550 static int tun_set_iff(struct net
*net
, struct file
*file
, struct ifreq
*ifr
)
1552 struct tun_struct
*tun
;
1553 struct tun_file
*tfile
= file
->private_data
;
1554 struct net_device
*dev
;
1557 if (tfile
->detached
)
1560 dev
= __dev_get_by_name(net
, ifr
->ifr_name
);
1562 if (ifr
->ifr_flags
& IFF_TUN_EXCL
)
1564 if ((ifr
->ifr_flags
& IFF_TUN
) && dev
->netdev_ops
== &tun_netdev_ops
)
1565 tun
= netdev_priv(dev
);
1566 else if ((ifr
->ifr_flags
& IFF_TAP
) && dev
->netdev_ops
== &tap_netdev_ops
)
1567 tun
= netdev_priv(dev
);
1571 if (!!(ifr
->ifr_flags
& IFF_MULTI_QUEUE
) !=
1572 !!(tun
->flags
& IFF_MULTI_QUEUE
))
1575 if (tun_not_capable(tun
))
1577 err
= security_tun_dev_open(tun
->security
);
1581 err
= tun_attach(tun
, file
, ifr
->ifr_flags
& IFF_NOFILTER
);
1585 if (tun
->flags
& IFF_MULTI_QUEUE
&&
1586 (tun
->numqueues
+ tun
->numdisabled
> 1)) {
1587 /* One or more queue has already been attached, no need
1588 * to initialize the device again.
1595 unsigned long flags
= 0;
1596 int queues
= ifr
->ifr_flags
& IFF_MULTI_QUEUE
?
1599 if (!ns_capable(net
->user_ns
, CAP_NET_ADMIN
))
1601 err
= security_tun_dev_create();
1606 if (ifr
->ifr_flags
& IFF_TUN
) {
1610 } else if (ifr
->ifr_flags
& IFF_TAP
) {
1618 name
= ifr
->ifr_name
;
1620 dev
= alloc_netdev_mqs(sizeof(struct tun_struct
), name
,
1621 NET_NAME_UNKNOWN
, tun_setup
, queues
,
1627 dev_net_set(dev
, net
);
1628 dev
->rtnl_link_ops
= &tun_link_ops
;
1629 dev
->ifindex
= tfile
->ifindex
;
1630 dev
->sysfs_groups
[0] = &tun_attr_group
;
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
&
1655 ~(NETIF_F_HW_VLAN_CTAG_TX
|
1656 NETIF_F_HW_VLAN_STAG_TX
);
1658 INIT_LIST_HEAD(&tun
->disabled
);
1659 err
= tun_attach(tun
, file
, false);
1663 err
= register_netdevice(tun
->dev
);
1668 netif_carrier_on(tun
->dev
);
1670 tun_debug(KERN_INFO
, tun
, "tun_set_iff\n");
1672 tun
->flags
= (tun
->flags
& ~TUN_FEATURES
) |
1673 (ifr
->ifr_flags
& TUN_FEATURES
);
1675 /* Make sure persistent devices do not get stuck in
1678 if (netif_running(tun
->dev
))
1679 netif_tx_wake_all_queues(tun
->dev
);
1681 strcpy(ifr
->ifr_name
, tun
->dev
->name
);
1685 tun_detach_all(dev
);
1687 tun_flow_uninit(tun
);
1688 security_tun_dev_free_security(tun
->security
);
1694 static void tun_get_iff(struct net
*net
, struct tun_struct
*tun
,
1697 tun_debug(KERN_INFO
, tun
, "tun_get_iff\n");
1699 strcpy(ifr
->ifr_name
, tun
->dev
->name
);
1701 ifr
->ifr_flags
= tun_flags(tun
);
1705 /* This is like a cut-down ethtool ops, except done via tun fd so no
1706 * privs required. */
1707 static int set_offload(struct tun_struct
*tun
, unsigned long arg
)
1709 netdev_features_t features
= 0;
1711 if (arg
& TUN_F_CSUM
) {
1712 features
|= NETIF_F_HW_CSUM
;
1715 if (arg
& (TUN_F_TSO4
|TUN_F_TSO6
)) {
1716 if (arg
& TUN_F_TSO_ECN
) {
1717 features
|= NETIF_F_TSO_ECN
;
1718 arg
&= ~TUN_F_TSO_ECN
;
1720 if (arg
& TUN_F_TSO4
)
1721 features
|= NETIF_F_TSO
;
1722 if (arg
& TUN_F_TSO6
)
1723 features
|= NETIF_F_TSO6
;
1724 arg
&= ~(TUN_F_TSO4
|TUN_F_TSO6
);
1727 if (arg
& TUN_F_UFO
) {
1728 features
|= NETIF_F_UFO
;
1733 /* This gives the user a way to test for new features in future by
1734 * trying to set them. */
1738 tun
->set_features
= features
;
1739 netdev_update_features(tun
->dev
);
1744 static void tun_detach_filter(struct tun_struct
*tun
, int n
)
1747 struct tun_file
*tfile
;
1749 for (i
= 0; i
< n
; i
++) {
1750 tfile
= rtnl_dereference(tun
->tfiles
[i
]);
1751 sk_detach_filter(tfile
->socket
.sk
);
1754 tun
->filter_attached
= false;
1757 static int tun_attach_filter(struct tun_struct
*tun
)
1760 struct tun_file
*tfile
;
1762 for (i
= 0; i
< tun
->numqueues
; i
++) {
1763 tfile
= rtnl_dereference(tun
->tfiles
[i
]);
1764 ret
= sk_attach_filter(&tun
->fprog
, tfile
->socket
.sk
);
1766 tun_detach_filter(tun
, i
);
1771 tun
->filter_attached
= true;
1775 static void tun_set_sndbuf(struct tun_struct
*tun
)
1777 struct tun_file
*tfile
;
1780 for (i
= 0; i
< tun
->numqueues
; i
++) {
1781 tfile
= rtnl_dereference(tun
->tfiles
[i
]);
1782 tfile
->socket
.sk
->sk_sndbuf
= tun
->sndbuf
;
1786 static int tun_set_queue(struct file
*file
, struct ifreq
*ifr
)
1788 struct tun_file
*tfile
= file
->private_data
;
1789 struct tun_struct
*tun
;
1794 if (ifr
->ifr_flags
& IFF_ATTACH_QUEUE
) {
1795 tun
= tfile
->detached
;
1800 ret
= security_tun_dev_attach_queue(tun
->security
);
1803 ret
= tun_attach(tun
, file
, false);
1804 } else if (ifr
->ifr_flags
& IFF_DETACH_QUEUE
) {
1805 tun
= rtnl_dereference(tfile
->tun
);
1806 if (!tun
|| !(tun
->flags
& IFF_MULTI_QUEUE
) || tfile
->detached
)
1809 __tun_detach(tfile
, false);
1818 static long __tun_chr_ioctl(struct file
*file
, unsigned int cmd
,
1819 unsigned long arg
, int ifreq_len
)
1821 struct tun_file
*tfile
= file
->private_data
;
1822 struct tun_struct
*tun
;
1823 void __user
* argp
= (void __user
*)arg
;
1829 unsigned int ifindex
;
1833 if (cmd
== TUNSETIFF
|| cmd
== TUNSETQUEUE
|| _IOC_TYPE(cmd
) == 0x89) {
1834 if (copy_from_user(&ifr
, argp
, ifreq_len
))
1837 memset(&ifr
, 0, sizeof(ifr
));
1839 if (cmd
== TUNGETFEATURES
) {
1840 /* Currently this just means: "what IFF flags are valid?".
1841 * This is needed because we never checked for invalid flags on
1844 return put_user(IFF_TUN
| IFF_TAP
| TUN_FEATURES
,
1845 (unsigned int __user
*)argp
);
1846 } else if (cmd
== TUNSETQUEUE
)
1847 return tun_set_queue(file
, &ifr
);
1852 tun
= __tun_get(tfile
);
1853 if (cmd
== TUNSETIFF
&& !tun
) {
1854 ifr
.ifr_name
[IFNAMSIZ
-1] = '\0';
1856 ret
= tun_set_iff(sock_net(&tfile
->sk
), file
, &ifr
);
1861 if (copy_to_user(argp
, &ifr
, ifreq_len
))
1865 if (cmd
== TUNSETIFINDEX
) {
1871 if (copy_from_user(&ifindex
, argp
, sizeof(ifindex
)))
1875 tfile
->ifindex
= ifindex
;
1883 tun_debug(KERN_INFO
, tun
, "tun_chr_ioctl cmd %u\n", cmd
);
1888 tun_get_iff(current
->nsproxy
->net_ns
, tun
, &ifr
);
1890 if (tfile
->detached
)
1891 ifr
.ifr_flags
|= IFF_DETACH_QUEUE
;
1892 if (!tfile
->socket
.sk
->sk_filter
)
1893 ifr
.ifr_flags
|= IFF_NOFILTER
;
1895 if (copy_to_user(argp
, &ifr
, ifreq_len
))
1900 /* Disable/Enable checksum */
1902 /* [unimplemented] */
1903 tun_debug(KERN_INFO
, tun
, "ignored: set checksum %s\n",
1904 arg
? "disabled" : "enabled");
1908 /* Disable/Enable persist mode. Keep an extra reference to the
1909 * module to prevent the module being unprobed.
1911 if (arg
&& !(tun
->flags
& IFF_PERSIST
)) {
1912 tun
->flags
|= IFF_PERSIST
;
1913 __module_get(THIS_MODULE
);
1915 if (!arg
&& (tun
->flags
& IFF_PERSIST
)) {
1916 tun
->flags
&= ~IFF_PERSIST
;
1917 module_put(THIS_MODULE
);
1920 tun_debug(KERN_INFO
, tun
, "persist %s\n",
1921 arg
? "enabled" : "disabled");
1925 /* Set owner of the device */
1926 owner
= make_kuid(current_user_ns(), arg
);
1927 if (!uid_valid(owner
)) {
1932 tun_debug(KERN_INFO
, tun
, "owner set to %u\n",
1933 from_kuid(&init_user_ns
, tun
->owner
));
1937 /* Set group of the device */
1938 group
= make_kgid(current_user_ns(), arg
);
1939 if (!gid_valid(group
)) {
1944 tun_debug(KERN_INFO
, tun
, "group set to %u\n",
1945 from_kgid(&init_user_ns
, tun
->group
));
1949 /* Only allow setting the type when the interface is down */
1950 if (tun
->dev
->flags
& IFF_UP
) {
1951 tun_debug(KERN_INFO
, tun
,
1952 "Linktype set failed because interface is up\n");
1955 tun
->dev
->type
= (int) arg
;
1956 tun_debug(KERN_INFO
, tun
, "linktype set to %d\n",
1968 ret
= set_offload(tun
, arg
);
1971 case TUNSETTXFILTER
:
1972 /* Can be set only for TAPs */
1974 if ((tun
->flags
& TUN_TYPE_MASK
) != IFF_TAP
)
1976 ret
= update_filter(&tun
->txflt
, (void __user
*)arg
);
1980 /* Get hw address */
1981 memcpy(ifr
.ifr_hwaddr
.sa_data
, tun
->dev
->dev_addr
, ETH_ALEN
);
1982 ifr
.ifr_hwaddr
.sa_family
= tun
->dev
->type
;
1983 if (copy_to_user(argp
, &ifr
, ifreq_len
))
1988 /* Set hw address */
1989 tun_debug(KERN_DEBUG
, tun
, "set hw address: %pM\n",
1990 ifr
.ifr_hwaddr
.sa_data
);
1992 ret
= dev_set_mac_address(tun
->dev
, &ifr
.ifr_hwaddr
);
1996 sndbuf
= tfile
->socket
.sk
->sk_sndbuf
;
1997 if (copy_to_user(argp
, &sndbuf
, sizeof(sndbuf
)))
2002 if (copy_from_user(&sndbuf
, argp
, sizeof(sndbuf
))) {
2007 tun
->sndbuf
= sndbuf
;
2008 tun_set_sndbuf(tun
);
2011 case TUNGETVNETHDRSZ
:
2012 vnet_hdr_sz
= tun
->vnet_hdr_sz
;
2013 if (copy_to_user(argp
, &vnet_hdr_sz
, sizeof(vnet_hdr_sz
)))
2017 case TUNSETVNETHDRSZ
:
2018 if (copy_from_user(&vnet_hdr_sz
, argp
, sizeof(vnet_hdr_sz
))) {
2022 if (vnet_hdr_sz
< (int)sizeof(struct virtio_net_hdr
)) {
2027 tun
->vnet_hdr_sz
= vnet_hdr_sz
;
2031 le
= !!(tun
->flags
& TUN_VNET_LE
);
2032 if (put_user(le
, (int __user
*)argp
))
2037 if (get_user(le
, (int __user
*)argp
)) {
2042 tun
->flags
|= TUN_VNET_LE
;
2044 tun
->flags
&= ~TUN_VNET_LE
;
2047 case TUNATTACHFILTER
:
2048 /* Can be set only for TAPs */
2050 if ((tun
->flags
& TUN_TYPE_MASK
) != IFF_TAP
)
2053 if (copy_from_user(&tun
->fprog
, argp
, sizeof(tun
->fprog
)))
2056 ret
= tun_attach_filter(tun
);
2059 case TUNDETACHFILTER
:
2060 /* Can be set only for TAPs */
2062 if ((tun
->flags
& TUN_TYPE_MASK
) != IFF_TAP
)
2065 tun_detach_filter(tun
, tun
->numqueues
);
2070 if ((tun
->flags
& TUN_TYPE_MASK
) != IFF_TAP
)
2073 if (copy_to_user(argp
, &tun
->fprog
, sizeof(tun
->fprog
)))
2090 static long tun_chr_ioctl(struct file
*file
,
2091 unsigned int cmd
, unsigned long arg
)
2093 return __tun_chr_ioctl(file
, cmd
, arg
, sizeof (struct ifreq
));
2096 #ifdef CONFIG_COMPAT
2097 static long tun_chr_compat_ioctl(struct file
*file
,
2098 unsigned int cmd
, unsigned long arg
)
2103 case TUNSETTXFILTER
:
2108 arg
= (unsigned long)compat_ptr(arg
);
2111 arg
= (compat_ulong_t
)arg
;
2116 * compat_ifreq is shorter than ifreq, so we must not access beyond
2117 * the end of that structure. All fields that are used in this
2118 * driver are compatible though, we don't need to convert the
2121 return __tun_chr_ioctl(file
, cmd
, arg
, sizeof(struct compat_ifreq
));
2123 #endif /* CONFIG_COMPAT */
2125 static int tun_chr_fasync(int fd
, struct file
*file
, int on
)
2127 struct tun_file
*tfile
= file
->private_data
;
2130 if ((ret
= fasync_helper(fd
, file
, on
, &tfile
->fasync
)) < 0)
2134 __f_setown(file
, task_pid(current
), PIDTYPE_PID
, 0);
2135 tfile
->flags
|= TUN_FASYNC
;
2137 tfile
->flags
&= ~TUN_FASYNC
;
2143 static int tun_chr_open(struct inode
*inode
, struct file
* file
)
2145 struct net
*net
= current
->nsproxy
->net_ns
;
2146 struct tun_file
*tfile
;
2148 DBG1(KERN_INFO
, "tunX: tun_chr_open\n");
2150 tfile
= (struct tun_file
*)sk_alloc(net
, AF_UNSPEC
, GFP_KERNEL
,
2154 RCU_INIT_POINTER(tfile
->tun
, NULL
);
2158 init_waitqueue_head(&tfile
->wq
.wait
);
2159 RCU_INIT_POINTER(tfile
->socket
.wq
, &tfile
->wq
);
2161 tfile
->socket
.file
= file
;
2162 tfile
->socket
.ops
= &tun_socket_ops
;
2164 sock_init_data(&tfile
->socket
, &tfile
->sk
);
2166 tfile
->sk
.sk_write_space
= tun_sock_write_space
;
2167 tfile
->sk
.sk_sndbuf
= INT_MAX
;
2169 file
->private_data
= tfile
;
2170 INIT_LIST_HEAD(&tfile
->next
);
2172 sock_set_flag(&tfile
->sk
, SOCK_ZEROCOPY
);
2177 static int tun_chr_close(struct inode
*inode
, struct file
*file
)
2179 struct tun_file
*tfile
= file
->private_data
;
2181 tun_detach(tfile
, true);
2186 #ifdef CONFIG_PROC_FS
2187 static void tun_chr_show_fdinfo(struct seq_file
*m
, struct file
*f
)
2189 struct tun_struct
*tun
;
2192 memset(&ifr
, 0, sizeof(ifr
));
2197 tun_get_iff(current
->nsproxy
->net_ns
, tun
, &ifr
);
2203 seq_printf(m
, "iff:\t%s\n", ifr
.ifr_name
);
2207 static const struct file_operations tun_fops
= {
2208 .owner
= THIS_MODULE
,
2209 .llseek
= no_llseek
,
2210 .read_iter
= tun_chr_read_iter
,
2211 .write_iter
= tun_chr_write_iter
,
2212 .poll
= tun_chr_poll
,
2213 .unlocked_ioctl
= tun_chr_ioctl
,
2214 #ifdef CONFIG_COMPAT
2215 .compat_ioctl
= tun_chr_compat_ioctl
,
2217 .open
= tun_chr_open
,
2218 .release
= tun_chr_close
,
2219 .fasync
= tun_chr_fasync
,
2220 #ifdef CONFIG_PROC_FS
2221 .show_fdinfo
= tun_chr_show_fdinfo
,
2225 static struct miscdevice tun_miscdev
= {
2228 .nodename
= "net/tun",
2232 /* ethtool interface */
2234 static int tun_get_settings(struct net_device
*dev
, struct ethtool_cmd
*cmd
)
2237 cmd
->advertising
= 0;
2238 ethtool_cmd_speed_set(cmd
, SPEED_10
);
2239 cmd
->duplex
= DUPLEX_FULL
;
2240 cmd
->port
= PORT_TP
;
2241 cmd
->phy_address
= 0;
2242 cmd
->transceiver
= XCVR_INTERNAL
;
2243 cmd
->autoneg
= AUTONEG_DISABLE
;
2249 static void tun_get_drvinfo(struct net_device
*dev
, struct ethtool_drvinfo
*info
)
2251 struct tun_struct
*tun
= netdev_priv(dev
);
2253 strlcpy(info
->driver
, DRV_NAME
, sizeof(info
->driver
));
2254 strlcpy(info
->version
, DRV_VERSION
, sizeof(info
->version
));
2256 switch (tun
->flags
& TUN_TYPE_MASK
) {
2258 strlcpy(info
->bus_info
, "tun", sizeof(info
->bus_info
));
2261 strlcpy(info
->bus_info
, "tap", sizeof(info
->bus_info
));
2266 static u32
tun_get_msglevel(struct net_device
*dev
)
2269 struct tun_struct
*tun
= netdev_priv(dev
);
2276 static void tun_set_msglevel(struct net_device
*dev
, u32 value
)
2279 struct tun_struct
*tun
= netdev_priv(dev
);
2284 static const struct ethtool_ops tun_ethtool_ops
= {
2285 .get_settings
= tun_get_settings
,
2286 .get_drvinfo
= tun_get_drvinfo
,
2287 .get_msglevel
= tun_get_msglevel
,
2288 .set_msglevel
= tun_set_msglevel
,
2289 .get_link
= ethtool_op_get_link
,
2290 .get_ts_info
= ethtool_op_get_ts_info
,
2294 static int __init
tun_init(void)
2298 pr_info("%s, %s\n", DRV_DESCRIPTION
, DRV_VERSION
);
2299 pr_info("%s\n", DRV_COPYRIGHT
);
2301 ret
= rtnl_link_register(&tun_link_ops
);
2303 pr_err("Can't register link_ops\n");
2307 ret
= misc_register(&tun_miscdev
);
2309 pr_err("Can't register misc device %d\n", TUN_MINOR
);
2314 rtnl_link_unregister(&tun_link_ops
);
2319 static void tun_cleanup(void)
2321 misc_deregister(&tun_miscdev
);
2322 rtnl_link_unregister(&tun_link_ops
);
2325 /* Get an underlying socket object from tun file. Returns error unless file is
2326 * attached to a device. The returned object works like a packet socket, it
2327 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
2328 * holding a reference to the file for as long as the socket is in use. */
2329 struct socket
*tun_get_socket(struct file
*file
)
2331 struct tun_file
*tfile
;
2332 if (file
->f_op
!= &tun_fops
)
2333 return ERR_PTR(-EINVAL
);
2334 tfile
= file
->private_data
;
2336 return ERR_PTR(-EBADFD
);
2337 return &tfile
->socket
;
2339 EXPORT_SYMBOL_GPL(tun_get_socket
);
2341 module_init(tun_init
);
2342 module_exit(tun_cleanup
);
2343 MODULE_DESCRIPTION(DRV_DESCRIPTION
);
2344 MODULE_AUTHOR(DRV_COPYRIGHT
);
2345 MODULE_LICENSE("GPL");
2346 MODULE_ALIAS_MISCDEV(TUN_MINOR
);
2347 MODULE_ALIAS("devname:net/tun");