1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * TUN - Universal TUN/TAP device driver.
4 * Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com>
6 * $Id: tun.c,v 1.15 2002/03/01 02:44:24 maxk Exp $
12 * Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14
13 * Add TUNSETLINK ioctl to set the link encapsulation
15 * Mark Smith <markzzzsmith@yahoo.com.au>
16 * Use eth_random_addr() for tap MAC address.
18 * Harald Roelle <harald.roelle@ifi.lmu.de> 2004/04/20
19 * Fixes in packet dropping, queue length setting and queue wakeup.
20 * Increased default tx queue length.
24 * Daniel Podlejski <underley@underley.eu.org>
25 * Modifications for 2.3.99-pre5 kernel.
28 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
30 #define DRV_NAME "tun"
31 #define DRV_VERSION "1.6"
32 #define DRV_DESCRIPTION "Universal TUN/TAP device driver"
33 #define DRV_COPYRIGHT "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>"
35 #include <linux/module.h>
36 #include <linux/errno.h>
37 #include <linux/kernel.h>
38 #include <linux/sched/signal.h>
39 #include <linux/major.h>
40 #include <linux/slab.h>
41 #include <linux/poll.h>
42 #include <linux/fcntl.h>
43 #include <linux/init.h>
44 #include <linux/skbuff.h>
45 #include <linux/netdevice.h>
46 #include <linux/etherdevice.h>
47 #include <linux/miscdevice.h>
48 #include <linux/ethtool.h>
49 #include <linux/rtnetlink.h>
50 #include <linux/compat.h>
52 #include <linux/if_arp.h>
53 #include <linux/if_ether.h>
54 #include <linux/if_tun.h>
55 #include <linux/if_vlan.h>
56 #include <linux/crc32.h>
57 #include <linux/nsproxy.h>
58 #include <linux/virtio_net.h>
59 #include <linux/rcupdate.h>
60 #include <net/net_namespace.h>
61 #include <net/netns/generic.h>
62 #include <net/rtnetlink.h>
65 #include <net/ip_tunnels.h>
66 #include <linux/seq_file.h>
67 #include <linux/uio.h>
68 #include <linux/skb_array.h>
69 #include <linux/bpf.h>
70 #include <linux/bpf_trace.h>
71 #include <linux/mutex.h>
72 #include <linux/ieee802154.h>
73 #include <linux/if_ltalk.h>
74 #include <uapi/linux/if_fddi.h>
75 #include <uapi/linux/if_hippi.h>
76 #include <uapi/linux/if_fc.h>
79 #include <net/6lowpan.h>
81 #include <linux/uaccess.h>
82 #include <linux/proc_fs.h>
84 static void tun_default_link_ksettings(struct net_device
*dev
,
85 struct ethtool_link_ksettings
*cmd
);
87 #define TUN_RX_PAD (NET_IP_ALIGN + NET_SKB_PAD)
89 /* TUN device flags */
91 /* IFF_ATTACH_QUEUE is never stored in device flags,
92 * overload it to mean fasync when stored there.
94 #define TUN_FASYNC IFF_ATTACH_QUEUE
95 /* High bits in flags field are unused. */
96 #define TUN_VNET_LE 0x80000000
97 #define TUN_VNET_BE 0x40000000
99 #define TUN_FEATURES (IFF_NO_PI | IFF_ONE_QUEUE | IFF_VNET_HDR | \
100 IFF_MULTI_QUEUE | IFF_NAPI | IFF_NAPI_FRAGS)
102 #define GOODCOPY_LEN 128
104 #define FLT_EXACT_COUNT 8
106 unsigned int count
; /* Number of addrs. Zero means disabled */
107 u32 mask
[2]; /* Mask of the hashed addrs */
108 unsigned char addr
[FLT_EXACT_COUNT
][ETH_ALEN
];
111 /* MAX_TAP_QUEUES 256 is chosen to allow rx/tx queues to be equal
112 * to max number of VCPUs in guest. */
113 #define MAX_TAP_QUEUES 256
114 #define MAX_TAP_FLOWS 4096
116 #define TUN_FLOW_EXPIRE (3 * HZ)
118 /* A tun_file connects an open character device to a tuntap netdevice. It
119 * also contains all socket related structures (except sock_fprog and tap_filter)
120 * to serve as one transmit queue for tuntap device. The sock_fprog and
121 * tap_filter were kept in tun_struct since they were used for filtering for the
122 * netdevice not for a specific queue (at least I didn't see the requirement for
126 * The tun_file and tun_struct are loosely coupled, the pointer from one to the
127 * other can only be read while rcu_read_lock or rtnl_lock is held.
131 struct socket socket
;
132 struct tun_struct __rcu
*tun
;
133 struct fasync_struct
*fasync
;
134 /* only used for fasnyc */
138 unsigned int ifindex
;
140 struct napi_struct napi
;
142 bool napi_frags_enabled
;
143 struct mutex napi_mutex
; /* Protects access to the above napi */
144 struct list_head next
;
145 struct tun_struct
*detached
;
146 struct ptr_ring tx_ring
;
147 struct xdp_rxq_info xdp_rxq
;
155 struct tun_flow_entry
{
156 struct hlist_node hash_link
;
158 struct tun_struct
*tun
;
163 unsigned long updated ____cacheline_aligned_in_smp
;
166 #define TUN_NUM_FLOW_ENTRIES 1024
167 #define TUN_MASK_FLOW_ENTRIES (TUN_NUM_FLOW_ENTRIES - 1)
171 struct bpf_prog
*prog
;
174 /* Since the socket were moved to tun_file, to preserve the behavior of persist
175 * device, socket filter, sndbuf and vnet header size were restore when the
176 * file were attached to a persist device.
179 struct tun_file __rcu
*tfiles
[MAX_TAP_QUEUES
];
180 unsigned int numqueues
;
185 struct net_device
*dev
;
186 netdev_features_t set_features
;
187 #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \
193 struct tap_filter txflt
;
194 struct sock_fprog fprog
;
195 /* protected by rtnl lock */
196 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
;
207 atomic_long_t rx_frame_errors
;
208 struct bpf_prog __rcu
*xdp_prog
;
209 struct tun_prog __rcu
*steering_prog
;
210 struct tun_prog __rcu
*filter_prog
;
211 struct ethtool_link_ksettings link_ksettings
;
222 static void tun_flow_init(struct tun_struct
*tun
);
223 static void tun_flow_uninit(struct tun_struct
*tun
);
225 static int tun_napi_receive(struct napi_struct
*napi
, int budget
)
227 struct tun_file
*tfile
= container_of(napi
, struct tun_file
, napi
);
228 struct sk_buff_head
*queue
= &tfile
->sk
.sk_write_queue
;
229 struct sk_buff_head process_queue
;
233 __skb_queue_head_init(&process_queue
);
235 spin_lock(&queue
->lock
);
236 skb_queue_splice_tail_init(queue
, &process_queue
);
237 spin_unlock(&queue
->lock
);
239 while (received
< budget
&& (skb
= __skb_dequeue(&process_queue
))) {
240 napi_gro_receive(napi
, skb
);
244 if (!skb_queue_empty(&process_queue
)) {
245 spin_lock(&queue
->lock
);
246 skb_queue_splice(&process_queue
, queue
);
247 spin_unlock(&queue
->lock
);
253 static int tun_napi_poll(struct napi_struct
*napi
, int budget
)
255 unsigned int received
;
257 received
= tun_napi_receive(napi
, budget
);
259 if (received
< budget
)
260 napi_complete_done(napi
, received
);
265 static void tun_napi_init(struct tun_struct
*tun
, struct tun_file
*tfile
,
266 bool napi_en
, bool napi_frags
)
268 tfile
->napi_enabled
= napi_en
;
269 tfile
->napi_frags_enabled
= napi_en
&& napi_frags
;
271 netif_tx_napi_add(tun
->dev
, &tfile
->napi
, tun_napi_poll
,
273 napi_enable(&tfile
->napi
);
277 static void tun_napi_disable(struct tun_file
*tfile
)
279 if (tfile
->napi_enabled
)
280 napi_disable(&tfile
->napi
);
283 static void tun_napi_del(struct tun_file
*tfile
)
285 if (tfile
->napi_enabled
)
286 netif_napi_del(&tfile
->napi
);
289 static bool tun_napi_frags_enabled(const struct tun_file
*tfile
)
291 return tfile
->napi_frags_enabled
;
294 #ifdef CONFIG_TUN_VNET_CROSS_LE
295 static inline bool tun_legacy_is_little_endian(struct tun_struct
*tun
)
297 return tun
->flags
& TUN_VNET_BE
? false :
298 virtio_legacy_is_little_endian();
301 static long tun_get_vnet_be(struct tun_struct
*tun
, int __user
*argp
)
303 int be
= !!(tun
->flags
& TUN_VNET_BE
);
305 if (put_user(be
, argp
))
311 static long tun_set_vnet_be(struct tun_struct
*tun
, int __user
*argp
)
315 if (get_user(be
, argp
))
319 tun
->flags
|= TUN_VNET_BE
;
321 tun
->flags
&= ~TUN_VNET_BE
;
326 static inline bool tun_legacy_is_little_endian(struct tun_struct
*tun
)
328 return virtio_legacy_is_little_endian();
331 static long tun_get_vnet_be(struct tun_struct
*tun
, int __user
*argp
)
336 static long tun_set_vnet_be(struct tun_struct
*tun
, int __user
*argp
)
340 #endif /* CONFIG_TUN_VNET_CROSS_LE */
342 static inline bool tun_is_little_endian(struct tun_struct
*tun
)
344 return tun
->flags
& TUN_VNET_LE
||
345 tun_legacy_is_little_endian(tun
);
348 static inline u16
tun16_to_cpu(struct tun_struct
*tun
, __virtio16 val
)
350 return __virtio16_to_cpu(tun_is_little_endian(tun
), val
);
353 static inline __virtio16
cpu_to_tun16(struct tun_struct
*tun
, u16 val
)
355 return __cpu_to_virtio16(tun_is_little_endian(tun
), val
);
358 static inline u32
tun_hashfn(u32 rxhash
)
360 return rxhash
& TUN_MASK_FLOW_ENTRIES
;
363 static struct tun_flow_entry
*tun_flow_find(struct hlist_head
*head
, u32 rxhash
)
365 struct tun_flow_entry
*e
;
367 hlist_for_each_entry_rcu(e
, head
, hash_link
) {
368 if (e
->rxhash
== rxhash
)
374 static struct tun_flow_entry
*tun_flow_create(struct tun_struct
*tun
,
375 struct hlist_head
*head
,
376 u32 rxhash
, u16 queue_index
)
378 struct tun_flow_entry
*e
= kmalloc(sizeof(*e
), GFP_ATOMIC
);
381 netif_info(tun
, tx_queued
, tun
->dev
,
382 "create flow: hash %u index %u\n",
383 rxhash
, queue_index
);
384 e
->updated
= jiffies
;
387 e
->queue_index
= queue_index
;
389 hlist_add_head_rcu(&e
->hash_link
, head
);
395 static void tun_flow_delete(struct tun_struct
*tun
, struct tun_flow_entry
*e
)
397 netif_info(tun
, tx_queued
, tun
->dev
, "delete flow: hash %u index %u\n",
398 e
->rxhash
, e
->queue_index
);
399 hlist_del_rcu(&e
->hash_link
);
404 static void tun_flow_flush(struct tun_struct
*tun
)
408 spin_lock_bh(&tun
->lock
);
409 for (i
= 0; i
< TUN_NUM_FLOW_ENTRIES
; i
++) {
410 struct tun_flow_entry
*e
;
411 struct hlist_node
*n
;
413 hlist_for_each_entry_safe(e
, n
, &tun
->flows
[i
], hash_link
)
414 tun_flow_delete(tun
, e
);
416 spin_unlock_bh(&tun
->lock
);
419 static void tun_flow_delete_by_queue(struct tun_struct
*tun
, u16 queue_index
)
423 spin_lock_bh(&tun
->lock
);
424 for (i
= 0; i
< TUN_NUM_FLOW_ENTRIES
; i
++) {
425 struct tun_flow_entry
*e
;
426 struct hlist_node
*n
;
428 hlist_for_each_entry_safe(e
, n
, &tun
->flows
[i
], hash_link
) {
429 if (e
->queue_index
== queue_index
)
430 tun_flow_delete(tun
, e
);
433 spin_unlock_bh(&tun
->lock
);
436 static void tun_flow_cleanup(struct timer_list
*t
)
438 struct tun_struct
*tun
= from_timer(tun
, t
, flow_gc_timer
);
439 unsigned long delay
= tun
->ageing_time
;
440 unsigned long next_timer
= jiffies
+ delay
;
441 unsigned long count
= 0;
444 spin_lock(&tun
->lock
);
445 for (i
= 0; i
< TUN_NUM_FLOW_ENTRIES
; i
++) {
446 struct tun_flow_entry
*e
;
447 struct hlist_node
*n
;
449 hlist_for_each_entry_safe(e
, n
, &tun
->flows
[i
], hash_link
) {
450 unsigned long this_timer
;
452 this_timer
= e
->updated
+ delay
;
453 if (time_before_eq(this_timer
, jiffies
)) {
454 tun_flow_delete(tun
, e
);
458 if (time_before(this_timer
, next_timer
))
459 next_timer
= this_timer
;
464 mod_timer(&tun
->flow_gc_timer
, round_jiffies_up(next_timer
));
465 spin_unlock(&tun
->lock
);
468 static void tun_flow_update(struct tun_struct
*tun
, u32 rxhash
,
469 struct tun_file
*tfile
)
471 struct hlist_head
*head
;
472 struct tun_flow_entry
*e
;
473 unsigned long delay
= tun
->ageing_time
;
474 u16 queue_index
= tfile
->queue_index
;
476 head
= &tun
->flows
[tun_hashfn(rxhash
)];
480 e
= tun_flow_find(head
, rxhash
);
482 /* TODO: keep queueing to old queue until it's empty? */
483 if (READ_ONCE(e
->queue_index
) != queue_index
)
484 WRITE_ONCE(e
->queue_index
, queue_index
);
485 if (e
->updated
!= jiffies
)
486 e
->updated
= jiffies
;
487 sock_rps_record_flow_hash(e
->rps_rxhash
);
489 spin_lock_bh(&tun
->lock
);
490 if (!tun_flow_find(head
, rxhash
) &&
491 tun
->flow_count
< MAX_TAP_FLOWS
)
492 tun_flow_create(tun
, head
, rxhash
, queue_index
);
494 if (!timer_pending(&tun
->flow_gc_timer
))
495 mod_timer(&tun
->flow_gc_timer
,
496 round_jiffies_up(jiffies
+ delay
));
497 spin_unlock_bh(&tun
->lock
);
503 /* Save the hash received in the stack receive path and update the
504 * flow_hash table accordingly.
506 static inline void tun_flow_save_rps_rxhash(struct tun_flow_entry
*e
, u32 hash
)
508 if (unlikely(e
->rps_rxhash
!= hash
))
509 e
->rps_rxhash
= hash
;
512 /* We try to identify a flow through its rxhash. The reason that
513 * we do not check rxq no. is because some cards(e.g 82599), chooses
514 * the rxq based on the txq where the last packet of the flow comes. As
515 * the userspace application move between processors, we may get a
516 * different rxq no. here.
518 static u16
tun_automq_select_queue(struct tun_struct
*tun
, struct sk_buff
*skb
)
520 struct tun_flow_entry
*e
;
524 numqueues
= READ_ONCE(tun
->numqueues
);
526 txq
= __skb_get_hash_symmetric(skb
);
527 e
= tun_flow_find(&tun
->flows
[tun_hashfn(txq
)], txq
);
529 tun_flow_save_rps_rxhash(e
, txq
);
530 txq
= e
->queue_index
;
532 /* use multiply and shift instead of expensive divide */
533 txq
= ((u64
)txq
* numqueues
) >> 32;
539 static u16
tun_ebpf_select_queue(struct tun_struct
*tun
, struct sk_buff
*skb
)
541 struct tun_prog
*prog
;
545 numqueues
= READ_ONCE(tun
->numqueues
);
549 prog
= rcu_dereference(tun
->steering_prog
);
551 ret
= bpf_prog_run_clear_cb(prog
->prog
, skb
);
553 return ret
% numqueues
;
556 static u16
tun_select_queue(struct net_device
*dev
, struct sk_buff
*skb
,
557 struct net_device
*sb_dev
)
559 struct tun_struct
*tun
= netdev_priv(dev
);
563 if (rcu_dereference(tun
->steering_prog
))
564 ret
= tun_ebpf_select_queue(tun
, skb
);
566 ret
= tun_automq_select_queue(tun
, skb
);
572 static inline bool tun_not_capable(struct tun_struct
*tun
)
574 const struct cred
*cred
= current_cred();
575 struct net
*net
= dev_net(tun
->dev
);
577 return ((uid_valid(tun
->owner
) && !uid_eq(cred
->euid
, tun
->owner
)) ||
578 (gid_valid(tun
->group
) && !in_egroup_p(tun
->group
))) &&
579 !ns_capable(net
->user_ns
, CAP_NET_ADMIN
);
582 static void tun_set_real_num_queues(struct tun_struct
*tun
)
584 netif_set_real_num_tx_queues(tun
->dev
, tun
->numqueues
);
585 netif_set_real_num_rx_queues(tun
->dev
, tun
->numqueues
);
588 static void tun_disable_queue(struct tun_struct
*tun
, struct tun_file
*tfile
)
590 tfile
->detached
= tun
;
591 list_add_tail(&tfile
->next
, &tun
->disabled
);
595 static struct tun_struct
*tun_enable_queue(struct tun_file
*tfile
)
597 struct tun_struct
*tun
= tfile
->detached
;
599 tfile
->detached
= NULL
;
600 list_del_init(&tfile
->next
);
605 void tun_ptr_free(void *ptr
)
609 if (tun_is_xdp_frame(ptr
)) {
610 struct xdp_frame
*xdpf
= tun_ptr_to_xdp(ptr
);
612 xdp_return_frame(xdpf
);
614 __skb_array_destroy_skb(ptr
);
617 EXPORT_SYMBOL_GPL(tun_ptr_free
);
619 static void tun_queue_purge(struct tun_file
*tfile
)
623 while ((ptr
= ptr_ring_consume(&tfile
->tx_ring
)) != NULL
)
626 skb_queue_purge(&tfile
->sk
.sk_write_queue
);
627 skb_queue_purge(&tfile
->sk
.sk_error_queue
);
630 static void __tun_detach(struct tun_file
*tfile
, bool clean
)
632 struct tun_file
*ntfile
;
633 struct tun_struct
*tun
;
635 tun
= rtnl_dereference(tfile
->tun
);
638 tun_napi_disable(tfile
);
642 if (tun
&& !tfile
->detached
) {
643 u16 index
= tfile
->queue_index
;
644 BUG_ON(index
>= tun
->numqueues
);
646 rcu_assign_pointer(tun
->tfiles
[index
],
647 tun
->tfiles
[tun
->numqueues
- 1]);
648 ntfile
= rtnl_dereference(tun
->tfiles
[index
]);
649 ntfile
->queue_index
= index
;
650 rcu_assign_pointer(tun
->tfiles
[tun
->numqueues
- 1],
655 RCU_INIT_POINTER(tfile
->tun
, NULL
);
656 sock_put(&tfile
->sk
);
658 tun_disable_queue(tun
, tfile
);
661 tun_flow_delete_by_queue(tun
, tun
->numqueues
+ 1);
662 /* Drop read queue */
663 tun_queue_purge(tfile
);
664 tun_set_real_num_queues(tun
);
665 } else if (tfile
->detached
&& clean
) {
666 tun
= tun_enable_queue(tfile
);
667 sock_put(&tfile
->sk
);
671 if (tun
&& tun
->numqueues
== 0 && tun
->numdisabled
== 0) {
672 netif_carrier_off(tun
->dev
);
674 if (!(tun
->flags
& IFF_PERSIST
) &&
675 tun
->dev
->reg_state
== NETREG_REGISTERED
)
676 unregister_netdevice(tun
->dev
);
679 xdp_rxq_info_unreg(&tfile
->xdp_rxq
);
680 ptr_ring_cleanup(&tfile
->tx_ring
, tun_ptr_free
);
681 sock_put(&tfile
->sk
);
685 static void tun_detach(struct tun_file
*tfile
, bool clean
)
687 struct tun_struct
*tun
;
688 struct net_device
*dev
;
691 tun
= rtnl_dereference(tfile
->tun
);
692 dev
= tun
? tun
->dev
: NULL
;
693 __tun_detach(tfile
, clean
);
695 netdev_state_change(dev
);
699 static void tun_detach_all(struct net_device
*dev
)
701 struct tun_struct
*tun
= netdev_priv(dev
);
702 struct tun_file
*tfile
, *tmp
;
703 int i
, n
= tun
->numqueues
;
705 for (i
= 0; i
< n
; i
++) {
706 tfile
= rtnl_dereference(tun
->tfiles
[i
]);
708 tun_napi_disable(tfile
);
709 tfile
->socket
.sk
->sk_shutdown
= RCV_SHUTDOWN
;
710 tfile
->socket
.sk
->sk_data_ready(tfile
->socket
.sk
);
711 RCU_INIT_POINTER(tfile
->tun
, NULL
);
714 list_for_each_entry(tfile
, &tun
->disabled
, next
) {
715 tfile
->socket
.sk
->sk_shutdown
= RCV_SHUTDOWN
;
716 tfile
->socket
.sk
->sk_data_ready(tfile
->socket
.sk
);
717 RCU_INIT_POINTER(tfile
->tun
, NULL
);
719 BUG_ON(tun
->numqueues
!= 0);
722 for (i
= 0; i
< n
; i
++) {
723 tfile
= rtnl_dereference(tun
->tfiles
[i
]);
725 /* Drop read queue */
726 tun_queue_purge(tfile
);
727 xdp_rxq_info_unreg(&tfile
->xdp_rxq
);
728 sock_put(&tfile
->sk
);
730 list_for_each_entry_safe(tfile
, tmp
, &tun
->disabled
, next
) {
731 tun_enable_queue(tfile
);
732 tun_queue_purge(tfile
);
733 xdp_rxq_info_unreg(&tfile
->xdp_rxq
);
734 sock_put(&tfile
->sk
);
736 BUG_ON(tun
->numdisabled
!= 0);
738 if (tun
->flags
& IFF_PERSIST
)
739 module_put(THIS_MODULE
);
742 static int tun_attach(struct tun_struct
*tun
, struct file
*file
,
743 bool skip_filter
, bool napi
, bool napi_frags
,
746 struct tun_file
*tfile
= file
->private_data
;
747 struct net_device
*dev
= tun
->dev
;
750 err
= security_tun_dev_attach(tfile
->socket
.sk
, tun
->security
);
755 if (rtnl_dereference(tfile
->tun
) && !tfile
->detached
)
759 if (!(tun
->flags
& IFF_MULTI_QUEUE
) && tun
->numqueues
== 1)
763 if (!tfile
->detached
&&
764 tun
->numqueues
+ tun
->numdisabled
== MAX_TAP_QUEUES
)
769 /* Re-attach the filter to persist device */
770 if (!skip_filter
&& (tun
->filter_attached
== true)) {
771 lock_sock(tfile
->socket
.sk
);
772 err
= sk_attach_filter(&tun
->fprog
, tfile
->socket
.sk
);
773 release_sock(tfile
->socket
.sk
);
778 if (!tfile
->detached
&&
779 ptr_ring_resize(&tfile
->tx_ring
, dev
->tx_queue_len
,
780 GFP_KERNEL
, tun_ptr_free
)) {
785 tfile
->queue_index
= tun
->numqueues
;
786 tfile
->socket
.sk
->sk_shutdown
&= ~RCV_SHUTDOWN
;
788 if (tfile
->detached
) {
789 /* Re-attach detached tfile, updating XDP queue_index */
790 WARN_ON(!xdp_rxq_info_is_reg(&tfile
->xdp_rxq
));
792 if (tfile
->xdp_rxq
.queue_index
!= tfile
->queue_index
)
793 tfile
->xdp_rxq
.queue_index
= tfile
->queue_index
;
795 /* Setup XDP RX-queue info, for new tfile getting attached */
796 err
= xdp_rxq_info_reg(&tfile
->xdp_rxq
,
797 tun
->dev
, tfile
->queue_index
, 0);
800 err
= xdp_rxq_info_reg_mem_model(&tfile
->xdp_rxq
,
801 MEM_TYPE_PAGE_SHARED
, NULL
);
803 xdp_rxq_info_unreg(&tfile
->xdp_rxq
);
809 if (tfile
->detached
) {
810 tun_enable_queue(tfile
);
812 sock_hold(&tfile
->sk
);
813 tun_napi_init(tun
, tfile
, napi
, napi_frags
);
816 if (rtnl_dereference(tun
->xdp_prog
))
817 sock_set_flag(&tfile
->sk
, SOCK_XDP
);
819 /* device is allowed to go away first, so no need to hold extra
823 /* Publish tfile->tun and tun->tfiles only after we've fully
824 * initialized tfile; otherwise we risk using half-initialized
828 rcu_assign_pointer(tfile
->tun
, tun
);
829 rcu_assign_pointer(tun
->tfiles
[tun
->numqueues
], tfile
);
831 tun_set_real_num_queues(tun
);
836 static struct tun_struct
*tun_get(struct tun_file
*tfile
)
838 struct tun_struct
*tun
;
841 tun
= rcu_dereference(tfile
->tun
);
849 static void tun_put(struct tun_struct
*tun
)
855 static void addr_hash_set(u32
*mask
, const u8
*addr
)
857 int n
= ether_crc(ETH_ALEN
, addr
) >> 26;
858 mask
[n
>> 5] |= (1 << (n
& 31));
861 static unsigned int addr_hash_test(const u32
*mask
, const u8
*addr
)
863 int n
= ether_crc(ETH_ALEN
, addr
) >> 26;
864 return mask
[n
>> 5] & (1 << (n
& 31));
867 static int update_filter(struct tap_filter
*filter
, void __user
*arg
)
869 struct { u8 u
[ETH_ALEN
]; } *addr
;
870 struct tun_filter uf
;
871 int err
, alen
, n
, nexact
;
873 if (copy_from_user(&uf
, arg
, sizeof(uf
)))
882 alen
= ETH_ALEN
* uf
.count
;
883 addr
= memdup_user(arg
+ sizeof(uf
), alen
);
885 return PTR_ERR(addr
);
887 /* The filter is updated without holding any locks. Which is
888 * perfectly safe. We disable it first and in the worst
889 * case we'll accept a few undesired packets. */
893 /* Use first set of addresses as an exact filter */
894 for (n
= 0; n
< uf
.count
&& n
< FLT_EXACT_COUNT
; n
++)
895 memcpy(filter
->addr
[n
], addr
[n
].u
, ETH_ALEN
);
899 /* Remaining multicast addresses are hashed,
900 * unicast will leave the filter disabled. */
901 memset(filter
->mask
, 0, sizeof(filter
->mask
));
902 for (; n
< uf
.count
; n
++) {
903 if (!is_multicast_ether_addr(addr
[n
].u
)) {
904 err
= 0; /* no filter */
907 addr_hash_set(filter
->mask
, addr
[n
].u
);
910 /* For ALLMULTI just set the mask to all ones.
911 * This overrides the mask populated above. */
912 if ((uf
.flags
& TUN_FLT_ALLMULTI
))
913 memset(filter
->mask
, ~0, sizeof(filter
->mask
));
915 /* Now enable the filter */
917 filter
->count
= nexact
;
919 /* Return the number of exact filters */
926 /* Returns: 0 - drop, !=0 - accept */
927 static int run_filter(struct tap_filter
*filter
, const struct sk_buff
*skb
)
929 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
931 struct ethhdr
*eh
= (struct ethhdr
*) skb
->data
;
935 for (i
= 0; i
< filter
->count
; i
++)
936 if (ether_addr_equal(eh
->h_dest
, filter
->addr
[i
]))
939 /* Inexact match (multicast only) */
940 if (is_multicast_ether_addr(eh
->h_dest
))
941 return addr_hash_test(filter
->mask
, eh
->h_dest
);
947 * Checks whether the packet is accepted or not.
948 * Returns: 0 - drop, !=0 - accept
950 static int check_filter(struct tap_filter
*filter
, const struct sk_buff
*skb
)
955 return run_filter(filter
, skb
);
958 /* Network device part of the driver */
960 static const struct ethtool_ops tun_ethtool_ops
;
962 static int tun_net_init(struct net_device
*dev
)
964 struct tun_struct
*tun
= netdev_priv(dev
);
965 struct ifreq
*ifr
= tun
->ifr
;
968 dev
->tstats
= netdev_alloc_pcpu_stats(struct pcpu_sw_netstats
);
972 spin_lock_init(&tun
->lock
);
974 err
= security_tun_dev_alloc_security(&tun
->security
);
976 free_percpu(dev
->tstats
);
982 dev
->hw_features
= NETIF_F_SG
| NETIF_F_FRAGLIST
|
983 TUN_USER_FEATURES
| NETIF_F_HW_VLAN_CTAG_TX
|
984 NETIF_F_HW_VLAN_STAG_TX
;
985 dev
->features
= dev
->hw_features
| NETIF_F_LLTX
;
986 dev
->vlan_features
= dev
->features
&
987 ~(NETIF_F_HW_VLAN_CTAG_TX
|
988 NETIF_F_HW_VLAN_STAG_TX
);
990 tun
->flags
= (tun
->flags
& ~TUN_FEATURES
) |
991 (ifr
->ifr_flags
& TUN_FEATURES
);
993 INIT_LIST_HEAD(&tun
->disabled
);
994 err
= tun_attach(tun
, tun
->file
, false, ifr
->ifr_flags
& IFF_NAPI
,
995 ifr
->ifr_flags
& IFF_NAPI_FRAGS
, false);
997 tun_flow_uninit(tun
);
998 security_tun_dev_free_security(tun
->security
);
999 free_percpu(dev
->tstats
);
1005 /* Net device detach from fd. */
1006 static void tun_net_uninit(struct net_device
*dev
)
1008 tun_detach_all(dev
);
1011 /* Net device open. */
1012 static int tun_net_open(struct net_device
*dev
)
1014 netif_tx_start_all_queues(dev
);
1019 /* Net device close. */
1020 static int tun_net_close(struct net_device
*dev
)
1022 netif_tx_stop_all_queues(dev
);
1026 /* Net device start xmit */
1027 static void tun_automq_xmit(struct tun_struct
*tun
, struct sk_buff
*skb
)
1030 if (tun
->numqueues
== 1 && static_branch_unlikely(&rps_needed
)) {
1031 /* Select queue was not called for the skbuff, so we extract the
1032 * RPS hash and save it into the flow_table here.
1034 struct tun_flow_entry
*e
;
1037 rxhash
= __skb_get_hash_symmetric(skb
);
1038 e
= tun_flow_find(&tun
->flows
[tun_hashfn(rxhash
)], rxhash
);
1040 tun_flow_save_rps_rxhash(e
, rxhash
);
1045 static unsigned int run_ebpf_filter(struct tun_struct
*tun
,
1046 struct sk_buff
*skb
,
1049 struct tun_prog
*prog
= rcu_dereference(tun
->filter_prog
);
1052 len
= bpf_prog_run_clear_cb(prog
->prog
, skb
);
1057 /* Net device start xmit */
1058 static netdev_tx_t
tun_net_xmit(struct sk_buff
*skb
, struct net_device
*dev
)
1060 struct tun_struct
*tun
= netdev_priv(dev
);
1061 int txq
= skb
->queue_mapping
;
1062 struct netdev_queue
*queue
;
1063 struct tun_file
*tfile
;
1067 tfile
= rcu_dereference(tun
->tfiles
[txq
]);
1069 /* Drop packet if interface is not attached */
1073 if (!rcu_dereference(tun
->steering_prog
))
1074 tun_automq_xmit(tun
, skb
);
1076 netif_info(tun
, tx_queued
, tun
->dev
, "%s %d\n", __func__
, skb
->len
);
1078 /* Drop if the filter does not like it.
1079 * This is a noop if the filter is disabled.
1080 * Filter can be enabled only for the TAP devices. */
1081 if (!check_filter(&tun
->txflt
, skb
))
1084 if (tfile
->socket
.sk
->sk_filter
&&
1085 sk_filter(tfile
->socket
.sk
, skb
))
1088 len
= run_ebpf_filter(tun
, skb
, len
);
1089 if (len
== 0 || pskb_trim(skb
, len
))
1092 if (unlikely(skb_orphan_frags_rx(skb
, GFP_ATOMIC
)))
1095 skb_tx_timestamp(skb
);
1097 /* Orphan the skb - required as we might hang on to it
1098 * for indefinite time.
1104 if (ptr_ring_produce(&tfile
->tx_ring
, skb
))
1107 /* NETIF_F_LLTX requires to do our own update of trans_start */
1108 queue
= netdev_get_tx_queue(dev
, txq
);
1109 queue
->trans_start
= jiffies
;
1111 /* Notify and wake up reader process */
1112 if (tfile
->flags
& TUN_FASYNC
)
1113 kill_fasync(&tfile
->fasync
, SIGIO
, POLL_IN
);
1114 tfile
->socket
.sk
->sk_data_ready(tfile
->socket
.sk
);
1117 return NETDEV_TX_OK
;
1120 atomic_long_inc(&dev
->tx_dropped
);
1124 return NET_XMIT_DROP
;
1127 static void tun_net_mclist(struct net_device
*dev
)
1130 * This callback is supposed to deal with mc filter in
1131 * _rx_ path and has nothing to do with the _tx_ path.
1132 * In rx path we always accept everything userspace gives us.
1136 static netdev_features_t
tun_net_fix_features(struct net_device
*dev
,
1137 netdev_features_t features
)
1139 struct tun_struct
*tun
= netdev_priv(dev
);
1141 return (features
& tun
->set_features
) | (features
& ~TUN_USER_FEATURES
);
1144 static void tun_set_headroom(struct net_device
*dev
, int new_hr
)
1146 struct tun_struct
*tun
= netdev_priv(dev
);
1148 if (new_hr
< NET_SKB_PAD
)
1149 new_hr
= NET_SKB_PAD
;
1151 tun
->align
= new_hr
;
1155 tun_net_get_stats64(struct net_device
*dev
, struct rtnl_link_stats64
*stats
)
1157 struct tun_struct
*tun
= netdev_priv(dev
);
1159 dev_get_tstats64(dev
, stats
);
1161 stats
->rx_frame_errors
+=
1162 (unsigned long)atomic_long_read(&tun
->rx_frame_errors
);
1165 static int tun_xdp_set(struct net_device
*dev
, struct bpf_prog
*prog
,
1166 struct netlink_ext_ack
*extack
)
1168 struct tun_struct
*tun
= netdev_priv(dev
);
1169 struct tun_file
*tfile
;
1170 struct bpf_prog
*old_prog
;
1173 old_prog
= rtnl_dereference(tun
->xdp_prog
);
1174 rcu_assign_pointer(tun
->xdp_prog
, prog
);
1176 bpf_prog_put(old_prog
);
1178 for (i
= 0; i
< tun
->numqueues
; i
++) {
1179 tfile
= rtnl_dereference(tun
->tfiles
[i
]);
1181 sock_set_flag(&tfile
->sk
, SOCK_XDP
);
1183 sock_reset_flag(&tfile
->sk
, SOCK_XDP
);
1185 list_for_each_entry(tfile
, &tun
->disabled
, next
) {
1187 sock_set_flag(&tfile
->sk
, SOCK_XDP
);
1189 sock_reset_flag(&tfile
->sk
, SOCK_XDP
);
1195 static int tun_xdp(struct net_device
*dev
, struct netdev_bpf
*xdp
)
1197 switch (xdp
->command
) {
1198 case XDP_SETUP_PROG
:
1199 return tun_xdp_set(dev
, xdp
->prog
, xdp
->extack
);
1205 static int tun_net_change_carrier(struct net_device
*dev
, bool new_carrier
)
1208 struct tun_struct
*tun
= netdev_priv(dev
);
1210 if (!tun
->numqueues
)
1213 netif_carrier_on(dev
);
1215 netif_carrier_off(dev
);
1220 static const struct net_device_ops tun_netdev_ops
= {
1221 .ndo_init
= tun_net_init
,
1222 .ndo_uninit
= tun_net_uninit
,
1223 .ndo_open
= tun_net_open
,
1224 .ndo_stop
= tun_net_close
,
1225 .ndo_start_xmit
= tun_net_xmit
,
1226 .ndo_fix_features
= tun_net_fix_features
,
1227 .ndo_select_queue
= tun_select_queue
,
1228 .ndo_set_rx_headroom
= tun_set_headroom
,
1229 .ndo_get_stats64
= tun_net_get_stats64
,
1230 .ndo_change_carrier
= tun_net_change_carrier
,
1233 static void __tun_xdp_flush_tfile(struct tun_file
*tfile
)
1235 /* Notify and wake up reader process */
1236 if (tfile
->flags
& TUN_FASYNC
)
1237 kill_fasync(&tfile
->fasync
, SIGIO
, POLL_IN
);
1238 tfile
->socket
.sk
->sk_data_ready(tfile
->socket
.sk
);
1241 static int tun_xdp_xmit(struct net_device
*dev
, int n
,
1242 struct xdp_frame
**frames
, u32 flags
)
1244 struct tun_struct
*tun
= netdev_priv(dev
);
1245 struct tun_file
*tfile
;
1250 if (unlikely(flags
& ~XDP_XMIT_FLAGS_MASK
))
1256 numqueues
= READ_ONCE(tun
->numqueues
);
1259 return -ENXIO
; /* Caller will free/return all frames */
1262 tfile
= rcu_dereference(tun
->tfiles
[smp_processor_id() %
1264 if (unlikely(!tfile
))
1267 spin_lock(&tfile
->tx_ring
.producer_lock
);
1268 for (i
= 0; i
< n
; i
++) {
1269 struct xdp_frame
*xdp
= frames
[i
];
1270 /* Encode the XDP flag into lowest bit for consumer to differ
1271 * XDP buffer from sk_buff.
1273 void *frame
= tun_xdp_to_ptr(xdp
);
1275 if (__ptr_ring_produce(&tfile
->tx_ring
, frame
)) {
1276 atomic_long_inc(&dev
->tx_dropped
);
1281 spin_unlock(&tfile
->tx_ring
.producer_lock
);
1283 if (flags
& XDP_XMIT_FLUSH
)
1284 __tun_xdp_flush_tfile(tfile
);
1290 static int tun_xdp_tx(struct net_device
*dev
, struct xdp_buff
*xdp
)
1292 struct xdp_frame
*frame
= xdp_convert_buff_to_frame(xdp
);
1295 if (unlikely(!frame
))
1298 nxmit
= tun_xdp_xmit(dev
, 1, &frame
, XDP_XMIT_FLUSH
);
1300 xdp_return_frame_rx_napi(frame
);
1304 static const struct net_device_ops tap_netdev_ops
= {
1305 .ndo_init
= tun_net_init
,
1306 .ndo_uninit
= tun_net_uninit
,
1307 .ndo_open
= tun_net_open
,
1308 .ndo_stop
= tun_net_close
,
1309 .ndo_start_xmit
= tun_net_xmit
,
1310 .ndo_fix_features
= tun_net_fix_features
,
1311 .ndo_set_rx_mode
= tun_net_mclist
,
1312 .ndo_set_mac_address
= eth_mac_addr
,
1313 .ndo_validate_addr
= eth_validate_addr
,
1314 .ndo_select_queue
= tun_select_queue
,
1315 .ndo_features_check
= passthru_features_check
,
1316 .ndo_set_rx_headroom
= tun_set_headroom
,
1317 .ndo_get_stats64
= dev_get_tstats64
,
1319 .ndo_xdp_xmit
= tun_xdp_xmit
,
1320 .ndo_change_carrier
= tun_net_change_carrier
,
1323 static void tun_flow_init(struct tun_struct
*tun
)
1327 for (i
= 0; i
< TUN_NUM_FLOW_ENTRIES
; i
++)
1328 INIT_HLIST_HEAD(&tun
->flows
[i
]);
1330 tun
->ageing_time
= TUN_FLOW_EXPIRE
;
1331 timer_setup(&tun
->flow_gc_timer
, tun_flow_cleanup
, 0);
1332 mod_timer(&tun
->flow_gc_timer
,
1333 round_jiffies_up(jiffies
+ tun
->ageing_time
));
1336 static void tun_flow_uninit(struct tun_struct
*tun
)
1338 del_timer_sync(&tun
->flow_gc_timer
);
1339 tun_flow_flush(tun
);
1343 #define MAX_MTU 65535
1345 /* Initialize net device. */
1346 static void tun_net_initialize(struct net_device
*dev
)
1348 struct tun_struct
*tun
= netdev_priv(dev
);
1350 switch (tun
->flags
& TUN_TYPE_MASK
) {
1352 dev
->netdev_ops
= &tun_netdev_ops
;
1353 dev
->header_ops
= &ip_tunnel_header_ops
;
1355 /* Point-to-Point TUN Device */
1356 dev
->hard_header_len
= 0;
1360 /* Zero header length */
1361 dev
->type
= ARPHRD_NONE
;
1362 dev
->flags
= IFF_POINTOPOINT
| IFF_NOARP
| IFF_MULTICAST
;
1366 dev
->netdev_ops
= &tap_netdev_ops
;
1367 /* Ethernet TAP Device */
1369 dev
->priv_flags
&= ~IFF_TX_SKB_SHARING
;
1370 dev
->priv_flags
|= IFF_LIVE_ADDR_CHANGE
;
1372 eth_hw_addr_random(dev
);
1377 dev
->min_mtu
= MIN_MTU
;
1378 dev
->max_mtu
= MAX_MTU
- dev
->hard_header_len
;
1381 static bool tun_sock_writeable(struct tun_struct
*tun
, struct tun_file
*tfile
)
1383 struct sock
*sk
= tfile
->socket
.sk
;
1385 return (tun
->dev
->flags
& IFF_UP
) && sock_writeable(sk
);
1388 /* Character device part */
1391 static __poll_t
tun_chr_poll(struct file
*file
, poll_table
*wait
)
1393 struct tun_file
*tfile
= file
->private_data
;
1394 struct tun_struct
*tun
= tun_get(tfile
);
1401 sk
= tfile
->socket
.sk
;
1403 poll_wait(file
, sk_sleep(sk
), wait
);
1405 if (!ptr_ring_empty(&tfile
->tx_ring
))
1406 mask
|= EPOLLIN
| EPOLLRDNORM
;
1408 /* Make sure SOCKWQ_ASYNC_NOSPACE is set if not writable to
1409 * guarantee EPOLLOUT to be raised by either here or
1410 * tun_sock_write_space(). Then process could get notification
1411 * after it writes to a down device and meets -EIO.
1413 if (tun_sock_writeable(tun
, tfile
) ||
1414 (!test_and_set_bit(SOCKWQ_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
) &&
1415 tun_sock_writeable(tun
, tfile
)))
1416 mask
|= EPOLLOUT
| EPOLLWRNORM
;
1418 if (tun
->dev
->reg_state
!= NETREG_REGISTERED
)
1425 static struct sk_buff
*tun_napi_alloc_frags(struct tun_file
*tfile
,
1427 const struct iov_iter
*it
)
1429 struct sk_buff
*skb
;
1434 if (it
->nr_segs
> MAX_SKB_FRAGS
+ 1)
1435 return ERR_PTR(-EMSGSIZE
);
1438 skb
= napi_get_frags(&tfile
->napi
);
1441 return ERR_PTR(-ENOMEM
);
1443 linear
= iov_iter_single_seg_count(it
);
1444 err
= __skb_grow(skb
, linear
);
1449 skb
->data_len
= len
- linear
;
1450 skb
->truesize
+= skb
->data_len
;
1452 for (i
= 1; i
< it
->nr_segs
; i
++) {
1453 size_t fragsz
= it
->iov
[i
].iov_len
;
1457 if (fragsz
== 0 || fragsz
> PAGE_SIZE
) {
1461 frag
= netdev_alloc_frag(fragsz
);
1466 page
= virt_to_head_page(frag
);
1467 skb_fill_page_desc(skb
, i
- 1, page
,
1468 frag
- page_address(page
), fragsz
);
1473 /* frees skb and all frags allocated with napi_alloc_frag() */
1474 napi_free_frags(&tfile
->napi
);
1475 return ERR_PTR(err
);
1478 /* prepad is the amount to reserve at front. len is length after that.
1479 * linear is a hint as to how much to copy (usually headers). */
1480 static struct sk_buff
*tun_alloc_skb(struct tun_file
*tfile
,
1481 size_t prepad
, size_t len
,
1482 size_t linear
, int noblock
)
1484 struct sock
*sk
= tfile
->socket
.sk
;
1485 struct sk_buff
*skb
;
1488 /* Under a page? Don't bother with paged skb. */
1489 if (prepad
+ len
< PAGE_SIZE
|| !linear
)
1492 skb
= sock_alloc_send_pskb(sk
, prepad
+ linear
, len
- linear
, noblock
,
1495 return ERR_PTR(err
);
1497 skb_reserve(skb
, prepad
);
1498 skb_put(skb
, linear
);
1499 skb
->data_len
= len
- linear
;
1500 skb
->len
+= len
- linear
;
1505 static void tun_rx_batched(struct tun_struct
*tun
, struct tun_file
*tfile
,
1506 struct sk_buff
*skb
, int more
)
1508 struct sk_buff_head
*queue
= &tfile
->sk
.sk_write_queue
;
1509 struct sk_buff_head process_queue
;
1510 u32 rx_batched
= tun
->rx_batched
;
1513 if (!rx_batched
|| (!more
&& skb_queue_empty(queue
))) {
1515 skb_record_rx_queue(skb
, tfile
->queue_index
);
1516 netif_receive_skb(skb
);
1521 spin_lock(&queue
->lock
);
1522 if (!more
|| skb_queue_len(queue
) == rx_batched
) {
1523 __skb_queue_head_init(&process_queue
);
1524 skb_queue_splice_tail_init(queue
, &process_queue
);
1527 __skb_queue_tail(queue
, skb
);
1529 spin_unlock(&queue
->lock
);
1532 struct sk_buff
*nskb
;
1535 while ((nskb
= __skb_dequeue(&process_queue
))) {
1536 skb_record_rx_queue(nskb
, tfile
->queue_index
);
1537 netif_receive_skb(nskb
);
1539 skb_record_rx_queue(skb
, tfile
->queue_index
);
1540 netif_receive_skb(skb
);
1545 static bool tun_can_build_skb(struct tun_struct
*tun
, struct tun_file
*tfile
,
1546 int len
, int noblock
, bool zerocopy
)
1548 if ((tun
->flags
& TUN_TYPE_MASK
) != IFF_TAP
)
1551 if (tfile
->socket
.sk
->sk_sndbuf
!= INT_MAX
)
1560 if (SKB_DATA_ALIGN(len
+ TUN_RX_PAD
) +
1561 SKB_DATA_ALIGN(sizeof(struct skb_shared_info
)) > PAGE_SIZE
)
1567 static struct sk_buff
*__tun_build_skb(struct tun_file
*tfile
,
1568 struct page_frag
*alloc_frag
, char *buf
,
1569 int buflen
, int len
, int pad
)
1571 struct sk_buff
*skb
= build_skb(buf
, buflen
);
1574 return ERR_PTR(-ENOMEM
);
1576 skb_reserve(skb
, pad
);
1578 skb_set_owner_w(skb
, tfile
->socket
.sk
);
1580 get_page(alloc_frag
->page
);
1581 alloc_frag
->offset
+= buflen
;
1586 static int tun_xdp_act(struct tun_struct
*tun
, struct bpf_prog
*xdp_prog
,
1587 struct xdp_buff
*xdp
, u32 act
)
1593 err
= xdp_do_redirect(tun
->dev
, xdp
, xdp_prog
);
1598 err
= tun_xdp_tx(tun
->dev
, xdp
);
1605 bpf_warn_invalid_xdp_action(act
);
1608 trace_xdp_exception(tun
->dev
, xdp_prog
, act
);
1611 atomic_long_inc(&tun
->dev
->rx_dropped
);
1618 static struct sk_buff
*tun_build_skb(struct tun_struct
*tun
,
1619 struct tun_file
*tfile
,
1620 struct iov_iter
*from
,
1621 struct virtio_net_hdr
*hdr
,
1622 int len
, int *skb_xdp
)
1624 struct page_frag
*alloc_frag
= ¤t
->task_frag
;
1625 struct bpf_prog
*xdp_prog
;
1626 int buflen
= SKB_DATA_ALIGN(sizeof(struct skb_shared_info
));
1629 int pad
= TUN_RX_PAD
;
1633 xdp_prog
= rcu_dereference(tun
->xdp_prog
);
1635 pad
+= XDP_PACKET_HEADROOM
;
1636 buflen
+= SKB_DATA_ALIGN(len
+ pad
);
1639 alloc_frag
->offset
= ALIGN((u64
)alloc_frag
->offset
, SMP_CACHE_BYTES
);
1640 if (unlikely(!skb_page_frag_refill(buflen
, alloc_frag
, GFP_KERNEL
)))
1641 return ERR_PTR(-ENOMEM
);
1643 buf
= (char *)page_address(alloc_frag
->page
) + alloc_frag
->offset
;
1644 copied
= copy_page_from_iter(alloc_frag
->page
,
1645 alloc_frag
->offset
+ pad
,
1648 return ERR_PTR(-EFAULT
);
1650 /* There's a small window that XDP may be set after the check
1651 * of xdp_prog above, this should be rare and for simplicity
1652 * we do XDP on skb in case the headroom is not enough.
1654 if (hdr
->gso_type
|| !xdp_prog
) {
1656 return __tun_build_skb(tfile
, alloc_frag
, buf
, buflen
, len
,
1664 xdp_prog
= rcu_dereference(tun
->xdp_prog
);
1666 struct xdp_buff xdp
;
1669 xdp_init_buff(&xdp
, buflen
, &tfile
->xdp_rxq
);
1670 xdp_prepare_buff(&xdp
, buf
, pad
, len
, false);
1672 act
= bpf_prog_run_xdp(xdp_prog
, &xdp
);
1673 if (act
== XDP_REDIRECT
|| act
== XDP_TX
) {
1674 get_page(alloc_frag
->page
);
1675 alloc_frag
->offset
+= buflen
;
1677 err
= tun_xdp_act(tun
, xdp_prog
, &xdp
, act
);
1679 if (act
== XDP_REDIRECT
|| act
== XDP_TX
)
1680 put_page(alloc_frag
->page
);
1684 if (err
== XDP_REDIRECT
)
1686 if (err
!= XDP_PASS
)
1689 pad
= xdp
.data
- xdp
.data_hard_start
;
1690 len
= xdp
.data_end
- xdp
.data
;
1695 return __tun_build_skb(tfile
, alloc_frag
, buf
, buflen
, len
, pad
);
1703 /* Get packet from user space buffer */
1704 static ssize_t
tun_get_user(struct tun_struct
*tun
, struct tun_file
*tfile
,
1705 void *msg_control
, struct iov_iter
*from
,
1706 int noblock
, bool more
)
1708 struct tun_pi pi
= { 0, cpu_to_be16(ETH_P_IP
) };
1709 struct sk_buff
*skb
;
1710 size_t total_len
= iov_iter_count(from
);
1711 size_t len
= total_len
, align
= tun
->align
, linear
;
1712 struct virtio_net_hdr gso
= { 0 };
1715 bool zerocopy
= false;
1719 bool frags
= tun_napi_frags_enabled(tfile
);
1721 if (!(tun
->flags
& IFF_NO_PI
)) {
1722 if (len
< sizeof(pi
))
1726 if (!copy_from_iter_full(&pi
, sizeof(pi
), from
))
1730 if (tun
->flags
& IFF_VNET_HDR
) {
1731 int vnet_hdr_sz
= READ_ONCE(tun
->vnet_hdr_sz
);
1733 if (len
< vnet_hdr_sz
)
1737 if (!copy_from_iter_full(&gso
, sizeof(gso
), from
))
1740 if ((gso
.flags
& VIRTIO_NET_HDR_F_NEEDS_CSUM
) &&
1741 tun16_to_cpu(tun
, gso
.csum_start
) + tun16_to_cpu(tun
, gso
.csum_offset
) + 2 > tun16_to_cpu(tun
, gso
.hdr_len
))
1742 gso
.hdr_len
= cpu_to_tun16(tun
, tun16_to_cpu(tun
, gso
.csum_start
) + tun16_to_cpu(tun
, gso
.csum_offset
) + 2);
1744 if (tun16_to_cpu(tun
, gso
.hdr_len
) > len
)
1746 iov_iter_advance(from
, vnet_hdr_sz
- sizeof(gso
));
1749 if ((tun
->flags
& TUN_TYPE_MASK
) == IFF_TAP
) {
1750 align
+= NET_IP_ALIGN
;
1751 if (unlikely(len
< ETH_HLEN
||
1752 (gso
.hdr_len
&& tun16_to_cpu(tun
, gso
.hdr_len
) < ETH_HLEN
)))
1756 good_linear
= SKB_MAX_HEAD(align
);
1759 struct iov_iter i
= *from
;
1761 /* There are 256 bytes to be copied in skb, so there is
1762 * enough room for skb expand head in case it is used.
1763 * The rest of the buffer is mapped from userspace.
1765 copylen
= gso
.hdr_len
? tun16_to_cpu(tun
, gso
.hdr_len
) : GOODCOPY_LEN
;
1766 if (copylen
> good_linear
)
1767 copylen
= good_linear
;
1769 iov_iter_advance(&i
, copylen
);
1770 if (iov_iter_npages(&i
, INT_MAX
) <= MAX_SKB_FRAGS
)
1774 if (!frags
&& tun_can_build_skb(tun
, tfile
, len
, noblock
, zerocopy
)) {
1775 /* For the packet that is not easy to be processed
1776 * (e.g gso or jumbo packet), we will do it at after
1777 * skb was created with generic XDP routine.
1779 skb
= tun_build_skb(tun
, tfile
, from
, &gso
, len
, &skb_xdp
);
1781 atomic_long_inc(&tun
->dev
->rx_dropped
);
1782 return PTR_ERR(skb
);
1789 if (tun16_to_cpu(tun
, gso
.hdr_len
) > good_linear
)
1790 linear
= good_linear
;
1792 linear
= tun16_to_cpu(tun
, gso
.hdr_len
);
1796 mutex_lock(&tfile
->napi_mutex
);
1797 skb
= tun_napi_alloc_frags(tfile
, copylen
, from
);
1798 /* tun_napi_alloc_frags() enforces a layout for the skb.
1799 * If zerocopy is enabled, then this layout will be
1800 * overwritten by zerocopy_sg_from_iter().
1804 skb
= tun_alloc_skb(tfile
, align
, copylen
, linear
,
1809 if (PTR_ERR(skb
) != -EAGAIN
)
1810 atomic_long_inc(&tun
->dev
->rx_dropped
);
1812 mutex_unlock(&tfile
->napi_mutex
);
1813 return PTR_ERR(skb
);
1817 err
= zerocopy_sg_from_iter(skb
, from
);
1819 err
= skb_copy_datagram_from_iter(skb
, 0, from
, len
);
1824 atomic_long_inc(&tun
->dev
->rx_dropped
);
1827 tfile
->napi
.skb
= NULL
;
1828 mutex_unlock(&tfile
->napi_mutex
);
1835 if (virtio_net_hdr_to_skb(skb
, &gso
, tun_is_little_endian(tun
))) {
1836 atomic_long_inc(&tun
->rx_frame_errors
);
1839 tfile
->napi
.skb
= NULL
;
1840 mutex_unlock(&tfile
->napi_mutex
);
1846 switch (tun
->flags
& TUN_TYPE_MASK
) {
1848 if (tun
->flags
& IFF_NO_PI
) {
1849 u8 ip_version
= skb
->len
? (skb
->data
[0] >> 4) : 0;
1851 switch (ip_version
) {
1853 pi
.proto
= htons(ETH_P_IP
);
1856 pi
.proto
= htons(ETH_P_IPV6
);
1859 atomic_long_inc(&tun
->dev
->rx_dropped
);
1865 skb_reset_mac_header(skb
);
1866 skb
->protocol
= pi
.proto
;
1867 skb
->dev
= tun
->dev
;
1870 if (frags
&& !pskb_may_pull(skb
, ETH_HLEN
)) {
1874 skb
->protocol
= eth_type_trans(skb
, tun
->dev
);
1878 /* copy skb_ubuf_info for callback when skb has no error */
1880 skb_zcopy_init(skb
, msg_control
);
1881 } else if (msg_control
) {
1882 struct ubuf_info
*uarg
= msg_control
;
1883 uarg
->callback(NULL
, uarg
, false);
1886 skb_reset_network_header(skb
);
1887 skb_probe_transport_header(skb
);
1888 skb_record_rx_queue(skb
, tfile
->queue_index
);
1891 struct bpf_prog
*xdp_prog
;
1896 xdp_prog
= rcu_dereference(tun
->xdp_prog
);
1898 ret
= do_xdp_generic(xdp_prog
, skb
);
1899 if (ret
!= XDP_PASS
) {
1903 tfile
->napi
.skb
= NULL
;
1904 mutex_unlock(&tfile
->napi_mutex
);
1913 /* Compute the costly rx hash only if needed for flow updates.
1914 * We may get a very small possibility of OOO during switching, not
1915 * worth to optimize.
1917 if (!rcu_access_pointer(tun
->steering_prog
) && tun
->numqueues
> 1 &&
1919 rxhash
= __skb_get_hash_symmetric(skb
);
1922 if (unlikely(!(tun
->dev
->flags
& IFF_UP
))) {
1931 /* Exercise flow dissector code path. */
1932 skb_push(skb
, ETH_HLEN
);
1933 headlen
= eth_get_headlen(tun
->dev
, skb
->data
,
1936 if (unlikely(headlen
> skb_headlen(skb
))) {
1937 atomic_long_inc(&tun
->dev
->rx_dropped
);
1938 napi_free_frags(&tfile
->napi
);
1940 mutex_unlock(&tfile
->napi_mutex
);
1946 napi_gro_frags(&tfile
->napi
);
1948 mutex_unlock(&tfile
->napi_mutex
);
1949 } else if (tfile
->napi_enabled
) {
1950 struct sk_buff_head
*queue
= &tfile
->sk
.sk_write_queue
;
1953 spin_lock_bh(&queue
->lock
);
1954 __skb_queue_tail(queue
, skb
);
1955 queue_len
= skb_queue_len(queue
);
1956 spin_unlock(&queue
->lock
);
1958 if (!more
|| queue_len
> NAPI_POLL_WEIGHT
)
1959 napi_schedule(&tfile
->napi
);
1962 } else if (!IS_ENABLED(CONFIG_4KSTACKS
)) {
1963 tun_rx_batched(tun
, tfile
, skb
, more
);
1970 dev_sw_netstats_rx_add(tun
->dev
, len
);
1974 tun_flow_update(tun
, rxhash
, tfile
);
1979 static ssize_t
tun_chr_write_iter(struct kiocb
*iocb
, struct iov_iter
*from
)
1981 struct file
*file
= iocb
->ki_filp
;
1982 struct tun_file
*tfile
= file
->private_data
;
1983 struct tun_struct
*tun
= tun_get(tfile
);
1990 if ((file
->f_flags
& O_NONBLOCK
) || (iocb
->ki_flags
& IOCB_NOWAIT
))
1993 result
= tun_get_user(tun
, tfile
, NULL
, from
, noblock
, false);
1999 static ssize_t
tun_put_user_xdp(struct tun_struct
*tun
,
2000 struct tun_file
*tfile
,
2001 struct xdp_frame
*xdp_frame
,
2002 struct iov_iter
*iter
)
2004 int vnet_hdr_sz
= 0;
2005 size_t size
= xdp_frame
->len
;
2008 if (tun
->flags
& IFF_VNET_HDR
) {
2009 struct virtio_net_hdr gso
= { 0 };
2011 vnet_hdr_sz
= READ_ONCE(tun
->vnet_hdr_sz
);
2012 if (unlikely(iov_iter_count(iter
) < vnet_hdr_sz
))
2014 if (unlikely(copy_to_iter(&gso
, sizeof(gso
), iter
) !=
2017 iov_iter_advance(iter
, vnet_hdr_sz
- sizeof(gso
));
2020 ret
= copy_to_iter(xdp_frame
->data
, size
, iter
) + vnet_hdr_sz
;
2023 dev_sw_netstats_tx_add(tun
->dev
, 1, ret
);
2029 /* Put packet to the user space buffer */
2030 static ssize_t
tun_put_user(struct tun_struct
*tun
,
2031 struct tun_file
*tfile
,
2032 struct sk_buff
*skb
,
2033 struct iov_iter
*iter
)
2035 struct tun_pi pi
= { 0, skb
->protocol
};
2037 int vlan_offset
= 0;
2039 int vnet_hdr_sz
= 0;
2041 if (skb_vlan_tag_present(skb
))
2042 vlan_hlen
= VLAN_HLEN
;
2044 if (tun
->flags
& IFF_VNET_HDR
)
2045 vnet_hdr_sz
= READ_ONCE(tun
->vnet_hdr_sz
);
2047 total
= skb
->len
+ vlan_hlen
+ vnet_hdr_sz
;
2049 if (!(tun
->flags
& IFF_NO_PI
)) {
2050 if (iov_iter_count(iter
) < sizeof(pi
))
2053 total
+= sizeof(pi
);
2054 if (iov_iter_count(iter
) < total
) {
2055 /* Packet will be striped */
2056 pi
.flags
|= TUN_PKT_STRIP
;
2059 if (copy_to_iter(&pi
, sizeof(pi
), iter
) != sizeof(pi
))
2064 struct virtio_net_hdr gso
;
2066 if (iov_iter_count(iter
) < vnet_hdr_sz
)
2069 if (virtio_net_hdr_from_skb(skb
, &gso
,
2070 tun_is_little_endian(tun
), true,
2072 struct skb_shared_info
*sinfo
= skb_shinfo(skb
);
2073 pr_err("unexpected GSO type: "
2074 "0x%x, gso_size %d, hdr_len %d\n",
2075 sinfo
->gso_type
, tun16_to_cpu(tun
, gso
.gso_size
),
2076 tun16_to_cpu(tun
, gso
.hdr_len
));
2077 print_hex_dump(KERN_ERR
, "tun: ",
2080 min((int)tun16_to_cpu(tun
, gso
.hdr_len
), 64), true);
2085 if (copy_to_iter(&gso
, sizeof(gso
), iter
) != sizeof(gso
))
2088 iov_iter_advance(iter
, vnet_hdr_sz
- sizeof(gso
));
2095 veth
.h_vlan_proto
= skb
->vlan_proto
;
2096 veth
.h_vlan_TCI
= htons(skb_vlan_tag_get(skb
));
2098 vlan_offset
= offsetof(struct vlan_ethhdr
, h_vlan_proto
);
2100 ret
= skb_copy_datagram_iter(skb
, 0, iter
, vlan_offset
);
2101 if (ret
|| !iov_iter_count(iter
))
2104 ret
= copy_to_iter(&veth
, sizeof(veth
), iter
);
2105 if (ret
!= sizeof(veth
) || !iov_iter_count(iter
))
2109 skb_copy_datagram_iter(skb
, vlan_offset
, iter
, skb
->len
- vlan_offset
);
2112 /* caller is in process context, */
2114 dev_sw_netstats_tx_add(tun
->dev
, 1, skb
->len
+ vlan_hlen
);
2120 static void *tun_ring_recv(struct tun_file
*tfile
, int noblock
, int *err
)
2122 DECLARE_WAITQUEUE(wait
, current
);
2126 ptr
= ptr_ring_consume(&tfile
->tx_ring
);
2134 add_wait_queue(&tfile
->socket
.wq
.wait
, &wait
);
2137 set_current_state(TASK_INTERRUPTIBLE
);
2138 ptr
= ptr_ring_consume(&tfile
->tx_ring
);
2141 if (signal_pending(current
)) {
2142 error
= -ERESTARTSYS
;
2145 if (tfile
->socket
.sk
->sk_shutdown
& RCV_SHUTDOWN
) {
2153 __set_current_state(TASK_RUNNING
);
2154 remove_wait_queue(&tfile
->socket
.wq
.wait
, &wait
);
2161 static ssize_t
tun_do_read(struct tun_struct
*tun
, struct tun_file
*tfile
,
2162 struct iov_iter
*to
,
2163 int noblock
, void *ptr
)
2168 if (!iov_iter_count(to
)) {
2174 /* Read frames from ring */
2175 ptr
= tun_ring_recv(tfile
, noblock
, &err
);
2180 if (tun_is_xdp_frame(ptr
)) {
2181 struct xdp_frame
*xdpf
= tun_ptr_to_xdp(ptr
);
2183 ret
= tun_put_user_xdp(tun
, tfile
, xdpf
, to
);
2184 xdp_return_frame(xdpf
);
2186 struct sk_buff
*skb
= ptr
;
2188 ret
= tun_put_user(tun
, tfile
, skb
, to
);
2189 if (unlikely(ret
< 0))
2198 static ssize_t
tun_chr_read_iter(struct kiocb
*iocb
, struct iov_iter
*to
)
2200 struct file
*file
= iocb
->ki_filp
;
2201 struct tun_file
*tfile
= file
->private_data
;
2202 struct tun_struct
*tun
= tun_get(tfile
);
2203 ssize_t len
= iov_iter_count(to
), ret
;
2209 if ((file
->f_flags
& O_NONBLOCK
) || (iocb
->ki_flags
& IOCB_NOWAIT
))
2212 ret
= tun_do_read(tun
, tfile
, to
, noblock
, NULL
);
2213 ret
= min_t(ssize_t
, ret
, len
);
2220 static void tun_prog_free(struct rcu_head
*rcu
)
2222 struct tun_prog
*prog
= container_of(rcu
, struct tun_prog
, rcu
);
2224 bpf_prog_destroy(prog
->prog
);
2228 static int __tun_set_ebpf(struct tun_struct
*tun
,
2229 struct tun_prog __rcu
**prog_p
,
2230 struct bpf_prog
*prog
)
2232 struct tun_prog
*old
, *new = NULL
;
2235 new = kmalloc(sizeof(*new), GFP_KERNEL
);
2241 spin_lock_bh(&tun
->lock
);
2242 old
= rcu_dereference_protected(*prog_p
,
2243 lockdep_is_held(&tun
->lock
));
2244 rcu_assign_pointer(*prog_p
, new);
2245 spin_unlock_bh(&tun
->lock
);
2248 call_rcu(&old
->rcu
, tun_prog_free
);
2253 static void tun_free_netdev(struct net_device
*dev
)
2255 struct tun_struct
*tun
= netdev_priv(dev
);
2257 BUG_ON(!(list_empty(&tun
->disabled
)));
2259 free_percpu(dev
->tstats
);
2260 tun_flow_uninit(tun
);
2261 security_tun_dev_free_security(tun
->security
);
2262 __tun_set_ebpf(tun
, &tun
->steering_prog
, NULL
);
2263 __tun_set_ebpf(tun
, &tun
->filter_prog
, NULL
);
2266 static void tun_setup(struct net_device
*dev
)
2268 struct tun_struct
*tun
= netdev_priv(dev
);
2270 tun
->owner
= INVALID_UID
;
2271 tun
->group
= INVALID_GID
;
2272 tun_default_link_ksettings(dev
, &tun
->link_ksettings
);
2274 dev
->ethtool_ops
= &tun_ethtool_ops
;
2275 dev
->needs_free_netdev
= true;
2276 dev
->priv_destructor
= tun_free_netdev
;
2277 /* We prefer our own queue length */
2278 dev
->tx_queue_len
= TUN_READQ_SIZE
;
2281 /* Trivial set of netlink ops to allow deleting tun or tap
2282 * device with netlink.
2284 static int tun_validate(struct nlattr
*tb
[], struct nlattr
*data
[],
2285 struct netlink_ext_ack
*extack
)
2287 NL_SET_ERR_MSG(extack
,
2288 "tun/tap creation via rtnetlink is not supported.");
2292 static size_t tun_get_size(const struct net_device
*dev
)
2294 BUILD_BUG_ON(sizeof(u32
) != sizeof(uid_t
));
2295 BUILD_BUG_ON(sizeof(u32
) != sizeof(gid_t
));
2297 return nla_total_size(sizeof(uid_t
)) + /* OWNER */
2298 nla_total_size(sizeof(gid_t
)) + /* GROUP */
2299 nla_total_size(sizeof(u8
)) + /* TYPE */
2300 nla_total_size(sizeof(u8
)) + /* PI */
2301 nla_total_size(sizeof(u8
)) + /* VNET_HDR */
2302 nla_total_size(sizeof(u8
)) + /* PERSIST */
2303 nla_total_size(sizeof(u8
)) + /* MULTI_QUEUE */
2304 nla_total_size(sizeof(u32
)) + /* NUM_QUEUES */
2305 nla_total_size(sizeof(u32
)) + /* NUM_DISABLED_QUEUES */
2309 static int tun_fill_info(struct sk_buff
*skb
, const struct net_device
*dev
)
2311 struct tun_struct
*tun
= netdev_priv(dev
);
2313 if (nla_put_u8(skb
, IFLA_TUN_TYPE
, tun
->flags
& TUN_TYPE_MASK
))
2314 goto nla_put_failure
;
2315 if (uid_valid(tun
->owner
) &&
2316 nla_put_u32(skb
, IFLA_TUN_OWNER
,
2317 from_kuid_munged(current_user_ns(), tun
->owner
)))
2318 goto nla_put_failure
;
2319 if (gid_valid(tun
->group
) &&
2320 nla_put_u32(skb
, IFLA_TUN_GROUP
,
2321 from_kgid_munged(current_user_ns(), tun
->group
)))
2322 goto nla_put_failure
;
2323 if (nla_put_u8(skb
, IFLA_TUN_PI
, !(tun
->flags
& IFF_NO_PI
)))
2324 goto nla_put_failure
;
2325 if (nla_put_u8(skb
, IFLA_TUN_VNET_HDR
, !!(tun
->flags
& IFF_VNET_HDR
)))
2326 goto nla_put_failure
;
2327 if (nla_put_u8(skb
, IFLA_TUN_PERSIST
, !!(tun
->flags
& IFF_PERSIST
)))
2328 goto nla_put_failure
;
2329 if (nla_put_u8(skb
, IFLA_TUN_MULTI_QUEUE
,
2330 !!(tun
->flags
& IFF_MULTI_QUEUE
)))
2331 goto nla_put_failure
;
2332 if (tun
->flags
& IFF_MULTI_QUEUE
) {
2333 if (nla_put_u32(skb
, IFLA_TUN_NUM_QUEUES
, tun
->numqueues
))
2334 goto nla_put_failure
;
2335 if (nla_put_u32(skb
, IFLA_TUN_NUM_DISABLED_QUEUES
,
2337 goto nla_put_failure
;
2346 static struct rtnl_link_ops tun_link_ops __read_mostly
= {
2348 .priv_size
= sizeof(struct tun_struct
),
2350 .validate
= tun_validate
,
2351 .get_size
= tun_get_size
,
2352 .fill_info
= tun_fill_info
,
2355 static void tun_sock_write_space(struct sock
*sk
)
2357 struct tun_file
*tfile
;
2358 wait_queue_head_t
*wqueue
;
2360 if (!sock_writeable(sk
))
2363 if (!test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
))
2366 wqueue
= sk_sleep(sk
);
2367 if (wqueue
&& waitqueue_active(wqueue
))
2368 wake_up_interruptible_sync_poll(wqueue
, EPOLLOUT
|
2369 EPOLLWRNORM
| EPOLLWRBAND
);
2371 tfile
= container_of(sk
, struct tun_file
, sk
);
2372 kill_fasync(&tfile
->fasync
, SIGIO
, POLL_OUT
);
2375 static void tun_put_page(struct tun_page
*tpage
)
2378 __page_frag_cache_drain(tpage
->page
, tpage
->count
);
2381 static int tun_xdp_one(struct tun_struct
*tun
,
2382 struct tun_file
*tfile
,
2383 struct xdp_buff
*xdp
, int *flush
,
2384 struct tun_page
*tpage
)
2386 unsigned int datasize
= xdp
->data_end
- xdp
->data
;
2387 struct tun_xdp_hdr
*hdr
= xdp
->data_hard_start
;
2388 struct virtio_net_hdr
*gso
= &hdr
->gso
;
2389 struct bpf_prog
*xdp_prog
;
2390 struct sk_buff
*skb
= NULL
;
2391 u32 rxhash
= 0, act
;
2392 int buflen
= hdr
->buflen
;
2394 bool skb_xdp
= false;
2397 xdp_prog
= rcu_dereference(tun
->xdp_prog
);
2399 if (gso
->gso_type
) {
2404 xdp_init_buff(xdp
, buflen
, &tfile
->xdp_rxq
);
2405 xdp_set_data_meta_invalid(xdp
);
2407 act
= bpf_prog_run_xdp(xdp_prog
, xdp
);
2408 err
= tun_xdp_act(tun
, xdp_prog
, xdp
, act
);
2410 put_page(virt_to_head_page(xdp
->data
));
2423 page
= virt_to_head_page(xdp
->data
);
2424 if (tpage
->page
== page
) {
2427 tun_put_page(tpage
);
2436 skb
= build_skb(xdp
->data_hard_start
, buflen
);
2442 skb_reserve(skb
, xdp
->data
- xdp
->data_hard_start
);
2443 skb_put(skb
, xdp
->data_end
- xdp
->data
);
2445 if (virtio_net_hdr_to_skb(skb
, gso
, tun_is_little_endian(tun
))) {
2446 atomic_long_inc(&tun
->rx_frame_errors
);
2452 skb
->protocol
= eth_type_trans(skb
, tun
->dev
);
2453 skb_reset_network_header(skb
);
2454 skb_probe_transport_header(skb
);
2455 skb_record_rx_queue(skb
, tfile
->queue_index
);
2458 err
= do_xdp_generic(xdp_prog
, skb
);
2459 if (err
!= XDP_PASS
)
2463 if (!rcu_dereference(tun
->steering_prog
) && tun
->numqueues
> 1 &&
2465 rxhash
= __skb_get_hash_symmetric(skb
);
2467 netif_receive_skb(skb
);
2469 /* No need to disable preemption here since this function is
2470 * always called with bh disabled
2472 dev_sw_netstats_rx_add(tun
->dev
, datasize
);
2475 tun_flow_update(tun
, rxhash
, tfile
);
2481 static int tun_sendmsg(struct socket
*sock
, struct msghdr
*m
, size_t total_len
)
2484 struct tun_file
*tfile
= container_of(sock
, struct tun_file
, socket
);
2485 struct tun_struct
*tun
= tun_get(tfile
);
2486 struct tun_msg_ctl
*ctl
= m
->msg_control
;
2487 struct xdp_buff
*xdp
;
2492 if (ctl
&& (ctl
->type
== TUN_MSG_PTR
)) {
2493 struct tun_page tpage
;
2497 memset(&tpage
, 0, sizeof(tpage
));
2502 for (i
= 0; i
< n
; i
++) {
2503 xdp
= &((struct xdp_buff
*)ctl
->ptr
)[i
];
2504 tun_xdp_one(tun
, tfile
, xdp
, &flush
, &tpage
);
2513 tun_put_page(&tpage
);
2519 ret
= tun_get_user(tun
, tfile
, ctl
? ctl
->ptr
: NULL
, &m
->msg_iter
,
2520 m
->msg_flags
& MSG_DONTWAIT
,
2521 m
->msg_flags
& MSG_MORE
);
2527 static int tun_recvmsg(struct socket
*sock
, struct msghdr
*m
, size_t total_len
,
2530 struct tun_file
*tfile
= container_of(sock
, struct tun_file
, socket
);
2531 struct tun_struct
*tun
= tun_get(tfile
);
2532 void *ptr
= m
->msg_control
;
2540 if (flags
& ~(MSG_DONTWAIT
|MSG_TRUNC
|MSG_ERRQUEUE
)) {
2544 if (flags
& MSG_ERRQUEUE
) {
2545 ret
= sock_recv_errqueue(sock
->sk
, m
, total_len
,
2546 SOL_PACKET
, TUN_TX_TIMESTAMP
);
2549 ret
= tun_do_read(tun
, tfile
, &m
->msg_iter
, flags
& MSG_DONTWAIT
, ptr
);
2550 if (ret
> (ssize_t
)total_len
) {
2551 m
->msg_flags
|= MSG_TRUNC
;
2552 ret
= flags
& MSG_TRUNC
? ret
: total_len
;
2565 static int tun_ptr_peek_len(void *ptr
)
2568 if (tun_is_xdp_frame(ptr
)) {
2569 struct xdp_frame
*xdpf
= tun_ptr_to_xdp(ptr
);
2573 return __skb_array_len_with_tag(ptr
);
2579 static int tun_peek_len(struct socket
*sock
)
2581 struct tun_file
*tfile
= container_of(sock
, struct tun_file
, socket
);
2582 struct tun_struct
*tun
;
2585 tun
= tun_get(tfile
);
2589 ret
= PTR_RING_PEEK_CALL(&tfile
->tx_ring
, tun_ptr_peek_len
);
2595 /* Ops structure to mimic raw sockets with tun */
2596 static const struct proto_ops tun_socket_ops
= {
2597 .peek_len
= tun_peek_len
,
2598 .sendmsg
= tun_sendmsg
,
2599 .recvmsg
= tun_recvmsg
,
2602 static struct proto tun_proto
= {
2604 .owner
= THIS_MODULE
,
2605 .obj_size
= sizeof(struct tun_file
),
2608 static int tun_flags(struct tun_struct
*tun
)
2610 return tun
->flags
& (TUN_FEATURES
| IFF_PERSIST
| IFF_TUN
| IFF_TAP
);
2613 static ssize_t
tun_flags_show(struct device
*dev
, struct device_attribute
*attr
,
2616 struct tun_struct
*tun
= netdev_priv(to_net_dev(dev
));
2617 return sprintf(buf
, "0x%x\n", tun_flags(tun
));
2620 static ssize_t
owner_show(struct device
*dev
, struct device_attribute
*attr
,
2623 struct tun_struct
*tun
= netdev_priv(to_net_dev(dev
));
2624 return uid_valid(tun
->owner
)?
2625 sprintf(buf
, "%u\n",
2626 from_kuid_munged(current_user_ns(), tun
->owner
)):
2627 sprintf(buf
, "-1\n");
2630 static ssize_t
group_show(struct device
*dev
, struct device_attribute
*attr
,
2633 struct tun_struct
*tun
= netdev_priv(to_net_dev(dev
));
2634 return gid_valid(tun
->group
) ?
2635 sprintf(buf
, "%u\n",
2636 from_kgid_munged(current_user_ns(), tun
->group
)):
2637 sprintf(buf
, "-1\n");
2640 static DEVICE_ATTR_RO(tun_flags
);
2641 static DEVICE_ATTR_RO(owner
);
2642 static DEVICE_ATTR_RO(group
);
2644 static struct attribute
*tun_dev_attrs
[] = {
2645 &dev_attr_tun_flags
.attr
,
2646 &dev_attr_owner
.attr
,
2647 &dev_attr_group
.attr
,
2651 static const struct attribute_group tun_attr_group
= {
2652 .attrs
= tun_dev_attrs
2655 static int tun_set_iff(struct net
*net
, struct file
*file
, struct ifreq
*ifr
)
2657 struct tun_struct
*tun
;
2658 struct tun_file
*tfile
= file
->private_data
;
2659 struct net_device
*dev
;
2662 if (tfile
->detached
)
2665 if ((ifr
->ifr_flags
& IFF_NAPI_FRAGS
)) {
2666 if (!capable(CAP_NET_ADMIN
))
2669 if (!(ifr
->ifr_flags
& IFF_NAPI
) ||
2670 (ifr
->ifr_flags
& TUN_TYPE_MASK
) != IFF_TAP
)
2674 dev
= __dev_get_by_name(net
, ifr
->ifr_name
);
2676 if (ifr
->ifr_flags
& IFF_TUN_EXCL
)
2678 if ((ifr
->ifr_flags
& IFF_TUN
) && dev
->netdev_ops
== &tun_netdev_ops
)
2679 tun
= netdev_priv(dev
);
2680 else if ((ifr
->ifr_flags
& IFF_TAP
) && dev
->netdev_ops
== &tap_netdev_ops
)
2681 tun
= netdev_priv(dev
);
2685 if (!!(ifr
->ifr_flags
& IFF_MULTI_QUEUE
) !=
2686 !!(tun
->flags
& IFF_MULTI_QUEUE
))
2689 if (tun_not_capable(tun
))
2691 err
= security_tun_dev_open(tun
->security
);
2695 err
= tun_attach(tun
, file
, ifr
->ifr_flags
& IFF_NOFILTER
,
2696 ifr
->ifr_flags
& IFF_NAPI
,
2697 ifr
->ifr_flags
& IFF_NAPI_FRAGS
, true);
2701 if (tun
->flags
& IFF_MULTI_QUEUE
&&
2702 (tun
->numqueues
+ tun
->numdisabled
> 1)) {
2703 /* One or more queue has already been attached, no need
2704 * to initialize the device again.
2706 netdev_state_change(dev
);
2710 tun
->flags
= (tun
->flags
& ~TUN_FEATURES
) |
2711 (ifr
->ifr_flags
& TUN_FEATURES
);
2713 netdev_state_change(dev
);
2716 unsigned long flags
= 0;
2717 int queues
= ifr
->ifr_flags
& IFF_MULTI_QUEUE
?
2720 if (!ns_capable(net
->user_ns
, CAP_NET_ADMIN
))
2722 err
= security_tun_dev_create();
2727 if (ifr
->ifr_flags
& IFF_TUN
) {
2731 } else if (ifr
->ifr_flags
& IFF_TAP
) {
2739 name
= ifr
->ifr_name
;
2741 dev
= alloc_netdev_mqs(sizeof(struct tun_struct
), name
,
2742 NET_NAME_UNKNOWN
, tun_setup
, queues
,
2748 dev_net_set(dev
, net
);
2749 dev
->rtnl_link_ops
= &tun_link_ops
;
2750 dev
->ifindex
= tfile
->ifindex
;
2751 dev
->sysfs_groups
[0] = &tun_attr_group
;
2753 tun
= netdev_priv(dev
);
2756 tun
->txflt
.count
= 0;
2757 tun
->vnet_hdr_sz
= sizeof(struct virtio_net_hdr
);
2759 tun
->align
= NET_SKB_PAD
;
2760 tun
->filter_attached
= false;
2761 tun
->sndbuf
= tfile
->socket
.sk
->sk_sndbuf
;
2762 tun
->rx_batched
= 0;
2763 RCU_INIT_POINTER(tun
->steering_prog
, NULL
);
2768 tun_net_initialize(dev
);
2770 err
= register_netdevice(tun
->dev
);
2775 /* free_netdev() won't check refcnt, to avoid race
2776 * with dev_put() we need publish tun after registration.
2778 rcu_assign_pointer(tfile
->tun
, tun
);
2781 netif_carrier_on(tun
->dev
);
2783 /* Make sure persistent devices do not get stuck in
2786 if (netif_running(tun
->dev
))
2787 netif_tx_wake_all_queues(tun
->dev
);
2789 strcpy(ifr
->ifr_name
, tun
->dev
->name
);
2793 static void tun_get_iff(struct tun_struct
*tun
, struct ifreq
*ifr
)
2795 strcpy(ifr
->ifr_name
, tun
->dev
->name
);
2797 ifr
->ifr_flags
= tun_flags(tun
);
2801 /* This is like a cut-down ethtool ops, except done via tun fd so no
2802 * privs required. */
2803 static int set_offload(struct tun_struct
*tun
, unsigned long arg
)
2805 netdev_features_t features
= 0;
2807 if (arg
& TUN_F_CSUM
) {
2808 features
|= NETIF_F_HW_CSUM
;
2811 if (arg
& (TUN_F_TSO4
|TUN_F_TSO6
)) {
2812 if (arg
& TUN_F_TSO_ECN
) {
2813 features
|= NETIF_F_TSO_ECN
;
2814 arg
&= ~TUN_F_TSO_ECN
;
2816 if (arg
& TUN_F_TSO4
)
2817 features
|= NETIF_F_TSO
;
2818 if (arg
& TUN_F_TSO6
)
2819 features
|= NETIF_F_TSO6
;
2820 arg
&= ~(TUN_F_TSO4
|TUN_F_TSO6
);
2826 /* This gives the user a way to test for new features in future by
2827 * trying to set them. */
2831 tun
->set_features
= features
;
2832 tun
->dev
->wanted_features
&= ~TUN_USER_FEATURES
;
2833 tun
->dev
->wanted_features
|= features
;
2834 netdev_update_features(tun
->dev
);
2839 static void tun_detach_filter(struct tun_struct
*tun
, int n
)
2842 struct tun_file
*tfile
;
2844 for (i
= 0; i
< n
; i
++) {
2845 tfile
= rtnl_dereference(tun
->tfiles
[i
]);
2846 lock_sock(tfile
->socket
.sk
);
2847 sk_detach_filter(tfile
->socket
.sk
);
2848 release_sock(tfile
->socket
.sk
);
2851 tun
->filter_attached
= false;
2854 static int tun_attach_filter(struct tun_struct
*tun
)
2857 struct tun_file
*tfile
;
2859 for (i
= 0; i
< tun
->numqueues
; i
++) {
2860 tfile
= rtnl_dereference(tun
->tfiles
[i
]);
2861 lock_sock(tfile
->socket
.sk
);
2862 ret
= sk_attach_filter(&tun
->fprog
, tfile
->socket
.sk
);
2863 release_sock(tfile
->socket
.sk
);
2865 tun_detach_filter(tun
, i
);
2870 tun
->filter_attached
= true;
2874 static void tun_set_sndbuf(struct tun_struct
*tun
)
2876 struct tun_file
*tfile
;
2879 for (i
= 0; i
< tun
->numqueues
; i
++) {
2880 tfile
= rtnl_dereference(tun
->tfiles
[i
]);
2881 tfile
->socket
.sk
->sk_sndbuf
= tun
->sndbuf
;
2885 static int tun_set_queue(struct file
*file
, struct ifreq
*ifr
)
2887 struct tun_file
*tfile
= file
->private_data
;
2888 struct tun_struct
*tun
;
2893 if (ifr
->ifr_flags
& IFF_ATTACH_QUEUE
) {
2894 tun
= tfile
->detached
;
2899 ret
= security_tun_dev_attach_queue(tun
->security
);
2902 ret
= tun_attach(tun
, file
, false, tun
->flags
& IFF_NAPI
,
2903 tun
->flags
& IFF_NAPI_FRAGS
, true);
2904 } else if (ifr
->ifr_flags
& IFF_DETACH_QUEUE
) {
2905 tun
= rtnl_dereference(tfile
->tun
);
2906 if (!tun
|| !(tun
->flags
& IFF_MULTI_QUEUE
) || tfile
->detached
)
2909 __tun_detach(tfile
, false);
2914 netdev_state_change(tun
->dev
);
2921 static int tun_set_ebpf(struct tun_struct
*tun
, struct tun_prog __rcu
**prog_p
,
2924 struct bpf_prog
*prog
;
2927 if (copy_from_user(&fd
, data
, sizeof(fd
)))
2933 prog
= bpf_prog_get_type(fd
, BPF_PROG_TYPE_SOCKET_FILTER
);
2935 return PTR_ERR(prog
);
2938 return __tun_set_ebpf(tun
, prog_p
, prog
);
2941 /* Return correct value for tun->dev->addr_len based on tun->dev->type. */
2942 static unsigned char tun_get_addr_len(unsigned short type
)
2946 case ARPHRD_TUNNEL6
:
2947 return sizeof(struct in6_addr
);
2954 case ARPHRD_IEEE802154
:
2955 case ARPHRD_IEEE802154_MONITOR
:
2956 return IEEE802154_EXTENDED_ADDR_LEN
;
2957 case ARPHRD_PHONET_PIPE
:
2961 case ARPHRD_6LOWPAN
:
2962 return EUI64_ADDR_LEN
;
2967 case ARPHRD_IEEE802
:
2970 return ROSE_ADDR_LEN
;
2972 return AX25_ADDR_LEN
;
2973 case ARPHRD_LOCALTLK
:
2980 static long __tun_chr_ioctl(struct file
*file
, unsigned int cmd
,
2981 unsigned long arg
, int ifreq_len
)
2983 struct tun_file
*tfile
= file
->private_data
;
2984 struct net
*net
= sock_net(&tfile
->sk
);
2985 struct tun_struct
*tun
;
2986 void __user
* argp
= (void __user
*)arg
;
2987 unsigned int ifindex
, carrier
;
2995 bool do_notify
= false;
2997 if (cmd
== TUNSETIFF
|| cmd
== TUNSETQUEUE
||
2998 (_IOC_TYPE(cmd
) == SOCK_IOC_TYPE
&& cmd
!= SIOCGSKNS
)) {
2999 if (copy_from_user(&ifr
, argp
, ifreq_len
))
3002 memset(&ifr
, 0, sizeof(ifr
));
3004 if (cmd
== TUNGETFEATURES
) {
3005 /* Currently this just means: "what IFF flags are valid?".
3006 * This is needed because we never checked for invalid flags on
3009 return put_user(IFF_TUN
| IFF_TAP
| TUN_FEATURES
,
3010 (unsigned int __user
*)argp
);
3011 } else if (cmd
== TUNSETQUEUE
) {
3012 return tun_set_queue(file
, &ifr
);
3013 } else if (cmd
== SIOCGSKNS
) {
3014 if (!ns_capable(net
->user_ns
, CAP_NET_ADMIN
))
3016 return open_related_ns(&net
->ns
, get_net_ns
);
3021 tun
= tun_get(tfile
);
3022 if (cmd
== TUNSETIFF
) {
3027 ifr
.ifr_name
[IFNAMSIZ
-1] = '\0';
3029 ret
= tun_set_iff(net
, file
, &ifr
);
3034 if (copy_to_user(argp
, &ifr
, ifreq_len
))
3038 if (cmd
== TUNSETIFINDEX
) {
3044 if (copy_from_user(&ifindex
, argp
, sizeof(ifindex
)))
3048 tfile
->ifindex
= ifindex
;
3056 netif_info(tun
, drv
, tun
->dev
, "tun_chr_ioctl cmd %u\n", cmd
);
3058 net
= dev_net(tun
->dev
);
3062 tun_get_iff(tun
, &ifr
);
3064 if (tfile
->detached
)
3065 ifr
.ifr_flags
|= IFF_DETACH_QUEUE
;
3066 if (!tfile
->socket
.sk
->sk_filter
)
3067 ifr
.ifr_flags
|= IFF_NOFILTER
;
3069 if (copy_to_user(argp
, &ifr
, ifreq_len
))
3074 /* Disable/Enable checksum */
3076 /* [unimplemented] */
3077 netif_info(tun
, drv
, tun
->dev
, "ignored: set checksum %s\n",
3078 arg
? "disabled" : "enabled");
3082 /* Disable/Enable persist mode. Keep an extra reference to the
3083 * module to prevent the module being unprobed.
3085 if (arg
&& !(tun
->flags
& IFF_PERSIST
)) {
3086 tun
->flags
|= IFF_PERSIST
;
3087 __module_get(THIS_MODULE
);
3090 if (!arg
&& (tun
->flags
& IFF_PERSIST
)) {
3091 tun
->flags
&= ~IFF_PERSIST
;
3092 module_put(THIS_MODULE
);
3096 netif_info(tun
, drv
, tun
->dev
, "persist %s\n",
3097 arg
? "enabled" : "disabled");
3101 /* Set owner of the device */
3102 owner
= make_kuid(current_user_ns(), arg
);
3103 if (!uid_valid(owner
)) {
3109 netif_info(tun
, drv
, tun
->dev
, "owner set to %u\n",
3110 from_kuid(&init_user_ns
, tun
->owner
));
3114 /* Set group of the device */
3115 group
= make_kgid(current_user_ns(), arg
);
3116 if (!gid_valid(group
)) {
3122 netif_info(tun
, drv
, tun
->dev
, "group set to %u\n",
3123 from_kgid(&init_user_ns
, tun
->group
));
3127 /* Only allow setting the type when the interface is down */
3128 if (tun
->dev
->flags
& IFF_UP
) {
3129 netif_info(tun
, drv
, tun
->dev
,
3130 "Linktype set failed because interface is up\n");
3133 ret
= call_netdevice_notifiers(NETDEV_PRE_TYPE_CHANGE
,
3135 ret
= notifier_to_errno(ret
);
3137 netif_info(tun
, drv
, tun
->dev
,
3138 "Refused to change device type\n");
3141 tun
->dev
->type
= (int) arg
;
3142 tun
->dev
->addr_len
= tun_get_addr_len(tun
->dev
->type
);
3143 netif_info(tun
, drv
, tun
->dev
, "linktype set to %d\n",
3145 call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE
,
3151 tun
->msg_enable
= (u32
)arg
;
3155 ret
= set_offload(tun
, arg
);
3158 case TUNSETTXFILTER
:
3159 /* Can be set only for TAPs */
3161 if ((tun
->flags
& TUN_TYPE_MASK
) != IFF_TAP
)
3163 ret
= update_filter(&tun
->txflt
, (void __user
*)arg
);
3167 /* Get hw address */
3168 dev_get_mac_address(&ifr
.ifr_hwaddr
, net
, tun
->dev
->name
);
3169 if (copy_to_user(argp
, &ifr
, ifreq_len
))
3174 /* Set hw address */
3175 ret
= dev_set_mac_address_user(tun
->dev
, &ifr
.ifr_hwaddr
, NULL
);
3179 sndbuf
= tfile
->socket
.sk
->sk_sndbuf
;
3180 if (copy_to_user(argp
, &sndbuf
, sizeof(sndbuf
)))
3185 if (copy_from_user(&sndbuf
, argp
, sizeof(sndbuf
))) {
3194 tun
->sndbuf
= sndbuf
;
3195 tun_set_sndbuf(tun
);
3198 case TUNGETVNETHDRSZ
:
3199 vnet_hdr_sz
= tun
->vnet_hdr_sz
;
3200 if (copy_to_user(argp
, &vnet_hdr_sz
, sizeof(vnet_hdr_sz
)))
3204 case TUNSETVNETHDRSZ
:
3205 if (copy_from_user(&vnet_hdr_sz
, argp
, sizeof(vnet_hdr_sz
))) {
3209 if (vnet_hdr_sz
< (int)sizeof(struct virtio_net_hdr
)) {
3214 tun
->vnet_hdr_sz
= vnet_hdr_sz
;
3218 le
= !!(tun
->flags
& TUN_VNET_LE
);
3219 if (put_user(le
, (int __user
*)argp
))
3224 if (get_user(le
, (int __user
*)argp
)) {
3229 tun
->flags
|= TUN_VNET_LE
;
3231 tun
->flags
&= ~TUN_VNET_LE
;
3235 ret
= tun_get_vnet_be(tun
, argp
);
3239 ret
= tun_set_vnet_be(tun
, argp
);
3242 case TUNATTACHFILTER
:
3243 /* Can be set only for TAPs */
3245 if ((tun
->flags
& TUN_TYPE_MASK
) != IFF_TAP
)
3248 if (copy_from_user(&tun
->fprog
, argp
, sizeof(tun
->fprog
)))
3251 ret
= tun_attach_filter(tun
);
3254 case TUNDETACHFILTER
:
3255 /* Can be set only for TAPs */
3257 if ((tun
->flags
& TUN_TYPE_MASK
) != IFF_TAP
)
3260 tun_detach_filter(tun
, tun
->numqueues
);
3265 if ((tun
->flags
& TUN_TYPE_MASK
) != IFF_TAP
)
3268 if (copy_to_user(argp
, &tun
->fprog
, sizeof(tun
->fprog
)))
3273 case TUNSETSTEERINGEBPF
:
3274 ret
= tun_set_ebpf(tun
, &tun
->steering_prog
, argp
);
3277 case TUNSETFILTEREBPF
:
3278 ret
= tun_set_ebpf(tun
, &tun
->filter_prog
, argp
);
3283 if (copy_from_user(&carrier
, argp
, sizeof(carrier
)))
3286 ret
= tun_net_change_carrier(tun
->dev
, (bool)carrier
);
3289 case TUNGETDEVNETNS
:
3291 if (!ns_capable(net
->user_ns
, CAP_NET_ADMIN
))
3293 ret
= open_related_ns(&net
->ns
, get_net_ns
);
3302 netdev_state_change(tun
->dev
);
3311 static long tun_chr_ioctl(struct file
*file
,
3312 unsigned int cmd
, unsigned long arg
)
3314 return __tun_chr_ioctl(file
, cmd
, arg
, sizeof (struct ifreq
));
3317 #ifdef CONFIG_COMPAT
3318 static long tun_chr_compat_ioctl(struct file
*file
,
3319 unsigned int cmd
, unsigned long arg
)
3324 case TUNSETTXFILTER
:
3329 arg
= (unsigned long)compat_ptr(arg
);
3332 arg
= (compat_ulong_t
)arg
;
3337 * compat_ifreq is shorter than ifreq, so we must not access beyond
3338 * the end of that structure. All fields that are used in this
3339 * driver are compatible though, we don't need to convert the
3342 return __tun_chr_ioctl(file
, cmd
, arg
, sizeof(struct compat_ifreq
));
3344 #endif /* CONFIG_COMPAT */
3346 static int tun_chr_fasync(int fd
, struct file
*file
, int on
)
3348 struct tun_file
*tfile
= file
->private_data
;
3351 if ((ret
= fasync_helper(fd
, file
, on
, &tfile
->fasync
)) < 0)
3355 __f_setown(file
, task_pid(current
), PIDTYPE_TGID
, 0);
3356 tfile
->flags
|= TUN_FASYNC
;
3358 tfile
->flags
&= ~TUN_FASYNC
;
3364 static int tun_chr_open(struct inode
*inode
, struct file
* file
)
3366 struct net
*net
= current
->nsproxy
->net_ns
;
3367 struct tun_file
*tfile
;
3369 tfile
= (struct tun_file
*)sk_alloc(net
, AF_UNSPEC
, GFP_KERNEL
,
3373 if (ptr_ring_init(&tfile
->tx_ring
, 0, GFP_KERNEL
)) {
3374 sk_free(&tfile
->sk
);
3378 mutex_init(&tfile
->napi_mutex
);
3379 RCU_INIT_POINTER(tfile
->tun
, NULL
);
3383 init_waitqueue_head(&tfile
->socket
.wq
.wait
);
3385 tfile
->socket
.file
= file
;
3386 tfile
->socket
.ops
= &tun_socket_ops
;
3388 sock_init_data(&tfile
->socket
, &tfile
->sk
);
3390 tfile
->sk
.sk_write_space
= tun_sock_write_space
;
3391 tfile
->sk
.sk_sndbuf
= INT_MAX
;
3393 file
->private_data
= tfile
;
3394 INIT_LIST_HEAD(&tfile
->next
);
3396 sock_set_flag(&tfile
->sk
, SOCK_ZEROCOPY
);
3401 static int tun_chr_close(struct inode
*inode
, struct file
*file
)
3403 struct tun_file
*tfile
= file
->private_data
;
3405 tun_detach(tfile
, true);
3410 #ifdef CONFIG_PROC_FS
3411 static void tun_chr_show_fdinfo(struct seq_file
*m
, struct file
*file
)
3413 struct tun_file
*tfile
= file
->private_data
;
3414 struct tun_struct
*tun
;
3417 memset(&ifr
, 0, sizeof(ifr
));
3420 tun
= tun_get(tfile
);
3422 tun_get_iff(tun
, &ifr
);
3428 seq_printf(m
, "iff:\t%s\n", ifr
.ifr_name
);
3432 static const struct file_operations tun_fops
= {
3433 .owner
= THIS_MODULE
,
3434 .llseek
= no_llseek
,
3435 .read_iter
= tun_chr_read_iter
,
3436 .write_iter
= tun_chr_write_iter
,
3437 .poll
= tun_chr_poll
,
3438 .unlocked_ioctl
= tun_chr_ioctl
,
3439 #ifdef CONFIG_COMPAT
3440 .compat_ioctl
= tun_chr_compat_ioctl
,
3442 .open
= tun_chr_open
,
3443 .release
= tun_chr_close
,
3444 .fasync
= tun_chr_fasync
,
3445 #ifdef CONFIG_PROC_FS
3446 .show_fdinfo
= tun_chr_show_fdinfo
,
3450 static struct miscdevice tun_miscdev
= {
3453 .nodename
= "net/tun",
3457 /* ethtool interface */
3459 static void tun_default_link_ksettings(struct net_device
*dev
,
3460 struct ethtool_link_ksettings
*cmd
)
3462 ethtool_link_ksettings_zero_link_mode(cmd
, supported
);
3463 ethtool_link_ksettings_zero_link_mode(cmd
, advertising
);
3464 cmd
->base
.speed
= SPEED_10
;
3465 cmd
->base
.duplex
= DUPLEX_FULL
;
3466 cmd
->base
.port
= PORT_TP
;
3467 cmd
->base
.phy_address
= 0;
3468 cmd
->base
.autoneg
= AUTONEG_DISABLE
;
3471 static int tun_get_link_ksettings(struct net_device
*dev
,
3472 struct ethtool_link_ksettings
*cmd
)
3474 struct tun_struct
*tun
= netdev_priv(dev
);
3476 memcpy(cmd
, &tun
->link_ksettings
, sizeof(*cmd
));
3480 static int tun_set_link_ksettings(struct net_device
*dev
,
3481 const struct ethtool_link_ksettings
*cmd
)
3483 struct tun_struct
*tun
= netdev_priv(dev
);
3485 memcpy(&tun
->link_ksettings
, cmd
, sizeof(*cmd
));
3489 static void tun_get_drvinfo(struct net_device
*dev
, struct ethtool_drvinfo
*info
)
3491 struct tun_struct
*tun
= netdev_priv(dev
);
3493 strlcpy(info
->driver
, DRV_NAME
, sizeof(info
->driver
));
3494 strlcpy(info
->version
, DRV_VERSION
, sizeof(info
->version
));
3496 switch (tun
->flags
& TUN_TYPE_MASK
) {
3498 strlcpy(info
->bus_info
, "tun", sizeof(info
->bus_info
));
3501 strlcpy(info
->bus_info
, "tap", sizeof(info
->bus_info
));
3506 static u32
tun_get_msglevel(struct net_device
*dev
)
3508 struct tun_struct
*tun
= netdev_priv(dev
);
3510 return tun
->msg_enable
;
3513 static void tun_set_msglevel(struct net_device
*dev
, u32 value
)
3515 struct tun_struct
*tun
= netdev_priv(dev
);
3517 tun
->msg_enable
= value
;
3520 static int tun_get_coalesce(struct net_device
*dev
,
3521 struct ethtool_coalesce
*ec
,
3522 struct kernel_ethtool_coalesce
*kernel_coal
,
3523 struct netlink_ext_ack
*extack
)
3525 struct tun_struct
*tun
= netdev_priv(dev
);
3527 ec
->rx_max_coalesced_frames
= tun
->rx_batched
;
3532 static int tun_set_coalesce(struct net_device
*dev
,
3533 struct ethtool_coalesce
*ec
,
3534 struct kernel_ethtool_coalesce
*kernel_coal
,
3535 struct netlink_ext_ack
*extack
)
3537 struct tun_struct
*tun
= netdev_priv(dev
);
3539 if (ec
->rx_max_coalesced_frames
> NAPI_POLL_WEIGHT
)
3540 tun
->rx_batched
= NAPI_POLL_WEIGHT
;
3542 tun
->rx_batched
= ec
->rx_max_coalesced_frames
;
3547 static const struct ethtool_ops tun_ethtool_ops
= {
3548 .supported_coalesce_params
= ETHTOOL_COALESCE_RX_MAX_FRAMES
,
3549 .get_drvinfo
= tun_get_drvinfo
,
3550 .get_msglevel
= tun_get_msglevel
,
3551 .set_msglevel
= tun_set_msglevel
,
3552 .get_link
= ethtool_op_get_link
,
3553 .get_ts_info
= ethtool_op_get_ts_info
,
3554 .get_coalesce
= tun_get_coalesce
,
3555 .set_coalesce
= tun_set_coalesce
,
3556 .get_link_ksettings
= tun_get_link_ksettings
,
3557 .set_link_ksettings
= tun_set_link_ksettings
,
3560 static int tun_queue_resize(struct tun_struct
*tun
)
3562 struct net_device
*dev
= tun
->dev
;
3563 struct tun_file
*tfile
;
3564 struct ptr_ring
**rings
;
3565 int n
= tun
->numqueues
+ tun
->numdisabled
;
3568 rings
= kmalloc_array(n
, sizeof(*rings
), GFP_KERNEL
);
3572 for (i
= 0; i
< tun
->numqueues
; i
++) {
3573 tfile
= rtnl_dereference(tun
->tfiles
[i
]);
3574 rings
[i
] = &tfile
->tx_ring
;
3576 list_for_each_entry(tfile
, &tun
->disabled
, next
)
3577 rings
[i
++] = &tfile
->tx_ring
;
3579 ret
= ptr_ring_resize_multiple(rings
, n
,
3580 dev
->tx_queue_len
, GFP_KERNEL
,
3587 static int tun_device_event(struct notifier_block
*unused
,
3588 unsigned long event
, void *ptr
)
3590 struct net_device
*dev
= netdev_notifier_info_to_dev(ptr
);
3591 struct tun_struct
*tun
= netdev_priv(dev
);
3594 if (dev
->rtnl_link_ops
!= &tun_link_ops
)
3598 case NETDEV_CHANGE_TX_QUEUE_LEN
:
3599 if (tun_queue_resize(tun
))
3603 for (i
= 0; i
< tun
->numqueues
; i
++) {
3604 struct tun_file
*tfile
;
3606 tfile
= rtnl_dereference(tun
->tfiles
[i
]);
3607 tfile
->socket
.sk
->sk_write_space(tfile
->socket
.sk
);
3617 static struct notifier_block tun_notifier_block __read_mostly
= {
3618 .notifier_call
= tun_device_event
,
3621 static int __init
tun_init(void)
3625 pr_info("%s, %s\n", DRV_DESCRIPTION
, DRV_VERSION
);
3627 ret
= rtnl_link_register(&tun_link_ops
);
3629 pr_err("Can't register link_ops\n");
3633 ret
= misc_register(&tun_miscdev
);
3635 pr_err("Can't register misc device %d\n", TUN_MINOR
);
3639 ret
= register_netdevice_notifier(&tun_notifier_block
);
3641 pr_err("Can't register netdevice notifier\n");
3648 misc_deregister(&tun_miscdev
);
3650 rtnl_link_unregister(&tun_link_ops
);
3655 static void tun_cleanup(void)
3657 misc_deregister(&tun_miscdev
);
3658 rtnl_link_unregister(&tun_link_ops
);
3659 unregister_netdevice_notifier(&tun_notifier_block
);
3662 /* Get an underlying socket object from tun file. Returns error unless file is
3663 * attached to a device. The returned object works like a packet socket, it
3664 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
3665 * holding a reference to the file for as long as the socket is in use. */
3666 struct socket
*tun_get_socket(struct file
*file
)
3668 struct tun_file
*tfile
;
3669 if (file
->f_op
!= &tun_fops
)
3670 return ERR_PTR(-EINVAL
);
3671 tfile
= file
->private_data
;
3673 return ERR_PTR(-EBADFD
);
3674 return &tfile
->socket
;
3676 EXPORT_SYMBOL_GPL(tun_get_socket
);
3678 struct ptr_ring
*tun_get_tx_ring(struct file
*file
)
3680 struct tun_file
*tfile
;
3682 if (file
->f_op
!= &tun_fops
)
3683 return ERR_PTR(-EINVAL
);
3684 tfile
= file
->private_data
;
3686 return ERR_PTR(-EBADFD
);
3687 return &tfile
->tx_ring
;
3689 EXPORT_SYMBOL_GPL(tun_get_tx_ring
);
3691 module_init(tun_init
);
3692 module_exit(tun_cleanup
);
3693 MODULE_DESCRIPTION(DRV_DESCRIPTION
);
3694 MODULE_AUTHOR(DRV_COPYRIGHT
);
3695 MODULE_LICENSE("GPL");
3696 MODULE_ALIAS_MISCDEV(TUN_MINOR
);
3697 MODULE_ALIAS("devname:net/tun");