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>
73 #include <linux/uaccess.h>
74 #include <linux/proc_fs.h>
76 static void tun_default_link_ksettings(struct net_device
*dev
,
77 struct ethtool_link_ksettings
*cmd
);
79 #define TUN_RX_PAD (NET_IP_ALIGN + NET_SKB_PAD)
81 /* TUN device flags */
83 /* IFF_ATTACH_QUEUE is never stored in device flags,
84 * overload it to mean fasync when stored there.
86 #define TUN_FASYNC IFF_ATTACH_QUEUE
87 /* High bits in flags field are unused. */
88 #define TUN_VNET_LE 0x80000000
89 #define TUN_VNET_BE 0x40000000
91 #define TUN_FEATURES (IFF_NO_PI | IFF_ONE_QUEUE | IFF_VNET_HDR | \
92 IFF_MULTI_QUEUE | IFF_NAPI | IFF_NAPI_FRAGS)
94 #define GOODCOPY_LEN 128
96 #define FLT_EXACT_COUNT 8
98 unsigned int count
; /* Number of addrs. Zero means disabled */
99 u32 mask
[2]; /* Mask of the hashed addrs */
100 unsigned char addr
[FLT_EXACT_COUNT
][ETH_ALEN
];
103 /* MAX_TAP_QUEUES 256 is chosen to allow rx/tx queues to be equal
104 * to max number of VCPUs in guest. */
105 #define MAX_TAP_QUEUES 256
106 #define MAX_TAP_FLOWS 4096
108 #define TUN_FLOW_EXPIRE (3 * HZ)
110 struct tun_pcpu_stats
{
111 u64_stats_t rx_packets
;
112 u64_stats_t rx_bytes
;
113 u64_stats_t tx_packets
;
114 u64_stats_t tx_bytes
;
115 struct u64_stats_sync syncp
;
121 /* A tun_file connects an open character device to a tuntap netdevice. It
122 * also contains all socket related structures (except sock_fprog and tap_filter)
123 * to serve as one transmit queue for tuntap device. The sock_fprog and
124 * tap_filter were kept in tun_struct since they were used for filtering for the
125 * netdevice not for a specific queue (at least I didn't see the requirement for
129 * The tun_file and tun_struct are loosely coupled, the pointer from one to the
130 * other can only be read while rcu_read_lock or rtnl_lock is held.
134 struct socket socket
;
135 struct tun_struct __rcu
*tun
;
136 struct fasync_struct
*fasync
;
137 /* only used for fasnyc */
141 unsigned int ifindex
;
143 struct napi_struct napi
;
145 bool napi_frags_enabled
;
146 struct mutex napi_mutex
; /* Protects access to the above napi */
147 struct list_head next
;
148 struct tun_struct
*detached
;
149 struct ptr_ring tx_ring
;
150 struct xdp_rxq_info xdp_rxq
;
158 struct tun_flow_entry
{
159 struct hlist_node hash_link
;
161 struct tun_struct
*tun
;
166 unsigned long updated ____cacheline_aligned_in_smp
;
169 #define TUN_NUM_FLOW_ENTRIES 1024
170 #define TUN_MASK_FLOW_ENTRIES (TUN_NUM_FLOW_ENTRIES - 1)
174 struct bpf_prog
*prog
;
177 /* Since the socket were moved to tun_file, to preserve the behavior of persist
178 * device, socket filter, sndbuf and vnet header size were restore when the
179 * file were attached to a persist device.
182 struct tun_file __rcu
*tfiles
[MAX_TAP_QUEUES
];
183 unsigned int numqueues
;
188 struct net_device
*dev
;
189 netdev_features_t set_features
;
190 #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \
196 struct tap_filter txflt
;
197 struct sock_fprog fprog
;
198 /* protected by rtnl lock */
199 bool filter_attached
;
202 struct hlist_head flows
[TUN_NUM_FLOW_ENTRIES
];
203 struct timer_list flow_gc_timer
;
204 unsigned long ageing_time
;
205 unsigned int numdisabled
;
206 struct list_head disabled
;
210 struct tun_pcpu_stats __percpu
*pcpu_stats
;
211 struct bpf_prog __rcu
*xdp_prog
;
212 struct tun_prog __rcu
*steering_prog
;
213 struct tun_prog __rcu
*filter_prog
;
214 struct ethtool_link_ksettings link_ksettings
;
222 static int tun_napi_receive(struct napi_struct
*napi
, int budget
)
224 struct tun_file
*tfile
= container_of(napi
, struct tun_file
, napi
);
225 struct sk_buff_head
*queue
= &tfile
->sk
.sk_write_queue
;
226 struct sk_buff_head process_queue
;
230 __skb_queue_head_init(&process_queue
);
232 spin_lock(&queue
->lock
);
233 skb_queue_splice_tail_init(queue
, &process_queue
);
234 spin_unlock(&queue
->lock
);
236 while (received
< budget
&& (skb
= __skb_dequeue(&process_queue
))) {
237 napi_gro_receive(napi
, skb
);
241 if (!skb_queue_empty(&process_queue
)) {
242 spin_lock(&queue
->lock
);
243 skb_queue_splice(&process_queue
, queue
);
244 spin_unlock(&queue
->lock
);
250 static int tun_napi_poll(struct napi_struct
*napi
, int budget
)
252 unsigned int received
;
254 received
= tun_napi_receive(napi
, budget
);
256 if (received
< budget
)
257 napi_complete_done(napi
, received
);
262 static void tun_napi_init(struct tun_struct
*tun
, struct tun_file
*tfile
,
263 bool napi_en
, bool napi_frags
)
265 tfile
->napi_enabled
= napi_en
;
266 tfile
->napi_frags_enabled
= napi_en
&& napi_frags
;
268 netif_tx_napi_add(tun
->dev
, &tfile
->napi
, tun_napi_poll
,
270 napi_enable(&tfile
->napi
);
274 static void tun_napi_disable(struct tun_file
*tfile
)
276 if (tfile
->napi_enabled
)
277 napi_disable(&tfile
->napi
);
280 static void tun_napi_del(struct tun_file
*tfile
)
282 if (tfile
->napi_enabled
)
283 netif_napi_del(&tfile
->napi
);
286 static bool tun_napi_frags_enabled(const struct tun_file
*tfile
)
288 return tfile
->napi_frags_enabled
;
291 #ifdef CONFIG_TUN_VNET_CROSS_LE
292 static inline bool tun_legacy_is_little_endian(struct tun_struct
*tun
)
294 return tun
->flags
& TUN_VNET_BE
? false :
295 virtio_legacy_is_little_endian();
298 static long tun_get_vnet_be(struct tun_struct
*tun
, int __user
*argp
)
300 int be
= !!(tun
->flags
& TUN_VNET_BE
);
302 if (put_user(be
, argp
))
308 static long tun_set_vnet_be(struct tun_struct
*tun
, int __user
*argp
)
312 if (get_user(be
, argp
))
316 tun
->flags
|= TUN_VNET_BE
;
318 tun
->flags
&= ~TUN_VNET_BE
;
323 static inline bool tun_legacy_is_little_endian(struct tun_struct
*tun
)
325 return virtio_legacy_is_little_endian();
328 static long tun_get_vnet_be(struct tun_struct
*tun
, int __user
*argp
)
333 static long tun_set_vnet_be(struct tun_struct
*tun
, int __user
*argp
)
337 #endif /* CONFIG_TUN_VNET_CROSS_LE */
339 static inline bool tun_is_little_endian(struct tun_struct
*tun
)
341 return tun
->flags
& TUN_VNET_LE
||
342 tun_legacy_is_little_endian(tun
);
345 static inline u16
tun16_to_cpu(struct tun_struct
*tun
, __virtio16 val
)
347 return __virtio16_to_cpu(tun_is_little_endian(tun
), val
);
350 static inline __virtio16
cpu_to_tun16(struct tun_struct
*tun
, u16 val
)
352 return __cpu_to_virtio16(tun_is_little_endian(tun
), val
);
355 static inline u32
tun_hashfn(u32 rxhash
)
357 return rxhash
& TUN_MASK_FLOW_ENTRIES
;
360 static struct tun_flow_entry
*tun_flow_find(struct hlist_head
*head
, u32 rxhash
)
362 struct tun_flow_entry
*e
;
364 hlist_for_each_entry_rcu(e
, head
, hash_link
) {
365 if (e
->rxhash
== rxhash
)
371 static struct tun_flow_entry
*tun_flow_create(struct tun_struct
*tun
,
372 struct hlist_head
*head
,
373 u32 rxhash
, u16 queue_index
)
375 struct tun_flow_entry
*e
= kmalloc(sizeof(*e
), GFP_ATOMIC
);
378 netif_info(tun
, tx_queued
, tun
->dev
,
379 "create flow: hash %u index %u\n",
380 rxhash
, queue_index
);
381 e
->updated
= jiffies
;
384 e
->queue_index
= queue_index
;
386 hlist_add_head_rcu(&e
->hash_link
, head
);
392 static void tun_flow_delete(struct tun_struct
*tun
, struct tun_flow_entry
*e
)
394 netif_info(tun
, tx_queued
, tun
->dev
, "delete flow: hash %u index %u\n",
395 e
->rxhash
, e
->queue_index
);
396 hlist_del_rcu(&e
->hash_link
);
401 static void tun_flow_flush(struct tun_struct
*tun
)
405 spin_lock_bh(&tun
->lock
);
406 for (i
= 0; i
< TUN_NUM_FLOW_ENTRIES
; i
++) {
407 struct tun_flow_entry
*e
;
408 struct hlist_node
*n
;
410 hlist_for_each_entry_safe(e
, n
, &tun
->flows
[i
], hash_link
)
411 tun_flow_delete(tun
, e
);
413 spin_unlock_bh(&tun
->lock
);
416 static void tun_flow_delete_by_queue(struct tun_struct
*tun
, u16 queue_index
)
420 spin_lock_bh(&tun
->lock
);
421 for (i
= 0; i
< TUN_NUM_FLOW_ENTRIES
; i
++) {
422 struct tun_flow_entry
*e
;
423 struct hlist_node
*n
;
425 hlist_for_each_entry_safe(e
, n
, &tun
->flows
[i
], hash_link
) {
426 if (e
->queue_index
== queue_index
)
427 tun_flow_delete(tun
, e
);
430 spin_unlock_bh(&tun
->lock
);
433 static void tun_flow_cleanup(struct timer_list
*t
)
435 struct tun_struct
*tun
= from_timer(tun
, t
, flow_gc_timer
);
436 unsigned long delay
= tun
->ageing_time
;
437 unsigned long next_timer
= jiffies
+ delay
;
438 unsigned long count
= 0;
441 spin_lock(&tun
->lock
);
442 for (i
= 0; i
< TUN_NUM_FLOW_ENTRIES
; i
++) {
443 struct tun_flow_entry
*e
;
444 struct hlist_node
*n
;
446 hlist_for_each_entry_safe(e
, n
, &tun
->flows
[i
], hash_link
) {
447 unsigned long this_timer
;
449 this_timer
= e
->updated
+ delay
;
450 if (time_before_eq(this_timer
, jiffies
)) {
451 tun_flow_delete(tun
, e
);
455 if (time_before(this_timer
, next_timer
))
456 next_timer
= this_timer
;
461 mod_timer(&tun
->flow_gc_timer
, round_jiffies_up(next_timer
));
462 spin_unlock(&tun
->lock
);
465 static void tun_flow_update(struct tun_struct
*tun
, u32 rxhash
,
466 struct tun_file
*tfile
)
468 struct hlist_head
*head
;
469 struct tun_flow_entry
*e
;
470 unsigned long delay
= tun
->ageing_time
;
471 u16 queue_index
= tfile
->queue_index
;
473 head
= &tun
->flows
[tun_hashfn(rxhash
)];
477 e
= tun_flow_find(head
, rxhash
);
479 /* TODO: keep queueing to old queue until it's empty? */
480 if (READ_ONCE(e
->queue_index
) != queue_index
)
481 WRITE_ONCE(e
->queue_index
, queue_index
);
482 if (e
->updated
!= jiffies
)
483 e
->updated
= jiffies
;
484 sock_rps_record_flow_hash(e
->rps_rxhash
);
486 spin_lock_bh(&tun
->lock
);
487 if (!tun_flow_find(head
, rxhash
) &&
488 tun
->flow_count
< MAX_TAP_FLOWS
)
489 tun_flow_create(tun
, head
, rxhash
, queue_index
);
491 if (!timer_pending(&tun
->flow_gc_timer
))
492 mod_timer(&tun
->flow_gc_timer
,
493 round_jiffies_up(jiffies
+ delay
));
494 spin_unlock_bh(&tun
->lock
);
500 /* Save the hash received in the stack receive path and update the
501 * flow_hash table accordingly.
503 static inline void tun_flow_save_rps_rxhash(struct tun_flow_entry
*e
, u32 hash
)
505 if (unlikely(e
->rps_rxhash
!= hash
))
506 e
->rps_rxhash
= hash
;
509 /* We try to identify a flow through its rxhash. The reason that
510 * we do not check rxq no. is because some cards(e.g 82599), chooses
511 * the rxq based on the txq where the last packet of the flow comes. As
512 * the userspace application move between processors, we may get a
513 * different rxq no. here.
515 static u16
tun_automq_select_queue(struct tun_struct
*tun
, struct sk_buff
*skb
)
517 struct tun_flow_entry
*e
;
521 numqueues
= READ_ONCE(tun
->numqueues
);
523 txq
= __skb_get_hash_symmetric(skb
);
524 e
= tun_flow_find(&tun
->flows
[tun_hashfn(txq
)], txq
);
526 tun_flow_save_rps_rxhash(e
, txq
);
527 txq
= e
->queue_index
;
529 /* use multiply and shift instead of expensive divide */
530 txq
= ((u64
)txq
* numqueues
) >> 32;
536 static u16
tun_ebpf_select_queue(struct tun_struct
*tun
, struct sk_buff
*skb
)
538 struct tun_prog
*prog
;
542 numqueues
= READ_ONCE(tun
->numqueues
);
546 prog
= rcu_dereference(tun
->steering_prog
);
548 ret
= bpf_prog_run_clear_cb(prog
->prog
, skb
);
550 return ret
% numqueues
;
553 static u16
tun_select_queue(struct net_device
*dev
, struct sk_buff
*skb
,
554 struct net_device
*sb_dev
)
556 struct tun_struct
*tun
= netdev_priv(dev
);
560 if (rcu_dereference(tun
->steering_prog
))
561 ret
= tun_ebpf_select_queue(tun
, skb
);
563 ret
= tun_automq_select_queue(tun
, skb
);
569 static inline bool tun_not_capable(struct tun_struct
*tun
)
571 const struct cred
*cred
= current_cred();
572 struct net
*net
= dev_net(tun
->dev
);
574 return ((uid_valid(tun
->owner
) && !uid_eq(cred
->euid
, tun
->owner
)) ||
575 (gid_valid(tun
->group
) && !in_egroup_p(tun
->group
))) &&
576 !ns_capable(net
->user_ns
, CAP_NET_ADMIN
);
579 static void tun_set_real_num_queues(struct tun_struct
*tun
)
581 netif_set_real_num_tx_queues(tun
->dev
, tun
->numqueues
);
582 netif_set_real_num_rx_queues(tun
->dev
, tun
->numqueues
);
585 static void tun_disable_queue(struct tun_struct
*tun
, struct tun_file
*tfile
)
587 tfile
->detached
= tun
;
588 list_add_tail(&tfile
->next
, &tun
->disabled
);
592 static struct tun_struct
*tun_enable_queue(struct tun_file
*tfile
)
594 struct tun_struct
*tun
= tfile
->detached
;
596 tfile
->detached
= NULL
;
597 list_del_init(&tfile
->next
);
602 void tun_ptr_free(void *ptr
)
606 if (tun_is_xdp_frame(ptr
)) {
607 struct xdp_frame
*xdpf
= tun_ptr_to_xdp(ptr
);
609 xdp_return_frame(xdpf
);
611 __skb_array_destroy_skb(ptr
);
614 EXPORT_SYMBOL_GPL(tun_ptr_free
);
616 static void tun_queue_purge(struct tun_file
*tfile
)
620 while ((ptr
= ptr_ring_consume(&tfile
->tx_ring
)) != NULL
)
623 skb_queue_purge(&tfile
->sk
.sk_write_queue
);
624 skb_queue_purge(&tfile
->sk
.sk_error_queue
);
627 static void __tun_detach(struct tun_file
*tfile
, bool clean
)
629 struct tun_file
*ntfile
;
630 struct tun_struct
*tun
;
632 tun
= rtnl_dereference(tfile
->tun
);
635 tun_napi_disable(tfile
);
639 if (tun
&& !tfile
->detached
) {
640 u16 index
= tfile
->queue_index
;
641 BUG_ON(index
>= tun
->numqueues
);
643 rcu_assign_pointer(tun
->tfiles
[index
],
644 tun
->tfiles
[tun
->numqueues
- 1]);
645 ntfile
= rtnl_dereference(tun
->tfiles
[index
]);
646 ntfile
->queue_index
= index
;
647 rcu_assign_pointer(tun
->tfiles
[tun
->numqueues
- 1],
652 RCU_INIT_POINTER(tfile
->tun
, NULL
);
653 sock_put(&tfile
->sk
);
655 tun_disable_queue(tun
, tfile
);
658 tun_flow_delete_by_queue(tun
, tun
->numqueues
+ 1);
659 /* Drop read queue */
660 tun_queue_purge(tfile
);
661 tun_set_real_num_queues(tun
);
662 } else if (tfile
->detached
&& clean
) {
663 tun
= tun_enable_queue(tfile
);
664 sock_put(&tfile
->sk
);
668 if (tun
&& tun
->numqueues
== 0 && tun
->numdisabled
== 0) {
669 netif_carrier_off(tun
->dev
);
671 if (!(tun
->flags
& IFF_PERSIST
) &&
672 tun
->dev
->reg_state
== NETREG_REGISTERED
)
673 unregister_netdevice(tun
->dev
);
676 xdp_rxq_info_unreg(&tfile
->xdp_rxq
);
677 ptr_ring_cleanup(&tfile
->tx_ring
, tun_ptr_free
);
678 sock_put(&tfile
->sk
);
682 static void tun_detach(struct tun_file
*tfile
, bool clean
)
684 struct tun_struct
*tun
;
685 struct net_device
*dev
;
688 tun
= rtnl_dereference(tfile
->tun
);
689 dev
= tun
? tun
->dev
: NULL
;
690 __tun_detach(tfile
, clean
);
692 netdev_state_change(dev
);
696 static void tun_detach_all(struct net_device
*dev
)
698 struct tun_struct
*tun
= netdev_priv(dev
);
699 struct tun_file
*tfile
, *tmp
;
700 int i
, n
= tun
->numqueues
;
702 for (i
= 0; i
< n
; i
++) {
703 tfile
= rtnl_dereference(tun
->tfiles
[i
]);
705 tun_napi_disable(tfile
);
706 tfile
->socket
.sk
->sk_shutdown
= RCV_SHUTDOWN
;
707 tfile
->socket
.sk
->sk_data_ready(tfile
->socket
.sk
);
708 RCU_INIT_POINTER(tfile
->tun
, NULL
);
711 list_for_each_entry(tfile
, &tun
->disabled
, next
) {
712 tfile
->socket
.sk
->sk_shutdown
= RCV_SHUTDOWN
;
713 tfile
->socket
.sk
->sk_data_ready(tfile
->socket
.sk
);
714 RCU_INIT_POINTER(tfile
->tun
, NULL
);
716 BUG_ON(tun
->numqueues
!= 0);
719 for (i
= 0; i
< n
; i
++) {
720 tfile
= rtnl_dereference(tun
->tfiles
[i
]);
722 /* Drop read queue */
723 tun_queue_purge(tfile
);
724 xdp_rxq_info_unreg(&tfile
->xdp_rxq
);
725 sock_put(&tfile
->sk
);
727 list_for_each_entry_safe(tfile
, tmp
, &tun
->disabled
, next
) {
728 tun_enable_queue(tfile
);
729 tun_queue_purge(tfile
);
730 xdp_rxq_info_unreg(&tfile
->xdp_rxq
);
731 sock_put(&tfile
->sk
);
733 BUG_ON(tun
->numdisabled
!= 0);
735 if (tun
->flags
& IFF_PERSIST
)
736 module_put(THIS_MODULE
);
739 static int tun_attach(struct tun_struct
*tun
, struct file
*file
,
740 bool skip_filter
, bool napi
, bool napi_frags
,
743 struct tun_file
*tfile
= file
->private_data
;
744 struct net_device
*dev
= tun
->dev
;
747 err
= security_tun_dev_attach(tfile
->socket
.sk
, tun
->security
);
752 if (rtnl_dereference(tfile
->tun
) && !tfile
->detached
)
756 if (!(tun
->flags
& IFF_MULTI_QUEUE
) && tun
->numqueues
== 1)
760 if (!tfile
->detached
&&
761 tun
->numqueues
+ tun
->numdisabled
== MAX_TAP_QUEUES
)
766 /* Re-attach the filter to persist device */
767 if (!skip_filter
&& (tun
->filter_attached
== true)) {
768 lock_sock(tfile
->socket
.sk
);
769 err
= sk_attach_filter(&tun
->fprog
, tfile
->socket
.sk
);
770 release_sock(tfile
->socket
.sk
);
775 if (!tfile
->detached
&&
776 ptr_ring_resize(&tfile
->tx_ring
, dev
->tx_queue_len
,
777 GFP_KERNEL
, tun_ptr_free
)) {
782 tfile
->queue_index
= tun
->numqueues
;
783 tfile
->socket
.sk
->sk_shutdown
&= ~RCV_SHUTDOWN
;
785 if (tfile
->detached
) {
786 /* Re-attach detached tfile, updating XDP queue_index */
787 WARN_ON(!xdp_rxq_info_is_reg(&tfile
->xdp_rxq
));
789 if (tfile
->xdp_rxq
.queue_index
!= tfile
->queue_index
)
790 tfile
->xdp_rxq
.queue_index
= tfile
->queue_index
;
792 /* Setup XDP RX-queue info, for new tfile getting attached */
793 err
= xdp_rxq_info_reg(&tfile
->xdp_rxq
,
794 tun
->dev
, tfile
->queue_index
);
797 err
= xdp_rxq_info_reg_mem_model(&tfile
->xdp_rxq
,
798 MEM_TYPE_PAGE_SHARED
, NULL
);
800 xdp_rxq_info_unreg(&tfile
->xdp_rxq
);
806 if (tfile
->detached
) {
807 tun_enable_queue(tfile
);
809 sock_hold(&tfile
->sk
);
810 tun_napi_init(tun
, tfile
, napi
, napi_frags
);
813 if (rtnl_dereference(tun
->xdp_prog
))
814 sock_set_flag(&tfile
->sk
, SOCK_XDP
);
816 /* device is allowed to go away first, so no need to hold extra
820 /* Publish tfile->tun and tun->tfiles only after we've fully
821 * initialized tfile; otherwise we risk using half-initialized
825 rcu_assign_pointer(tfile
->tun
, tun
);
826 rcu_assign_pointer(tun
->tfiles
[tun
->numqueues
], tfile
);
828 tun_set_real_num_queues(tun
);
833 static struct tun_struct
*tun_get(struct tun_file
*tfile
)
835 struct tun_struct
*tun
;
838 tun
= rcu_dereference(tfile
->tun
);
846 static void tun_put(struct tun_struct
*tun
)
852 static void addr_hash_set(u32
*mask
, const u8
*addr
)
854 int n
= ether_crc(ETH_ALEN
, addr
) >> 26;
855 mask
[n
>> 5] |= (1 << (n
& 31));
858 static unsigned int addr_hash_test(const u32
*mask
, const u8
*addr
)
860 int n
= ether_crc(ETH_ALEN
, addr
) >> 26;
861 return mask
[n
>> 5] & (1 << (n
& 31));
864 static int update_filter(struct tap_filter
*filter
, void __user
*arg
)
866 struct { u8 u
[ETH_ALEN
]; } *addr
;
867 struct tun_filter uf
;
868 int err
, alen
, n
, nexact
;
870 if (copy_from_user(&uf
, arg
, sizeof(uf
)))
879 alen
= ETH_ALEN
* uf
.count
;
880 addr
= memdup_user(arg
+ sizeof(uf
), alen
);
882 return PTR_ERR(addr
);
884 /* The filter is updated without holding any locks. Which is
885 * perfectly safe. We disable it first and in the worst
886 * case we'll accept a few undesired packets. */
890 /* Use first set of addresses as an exact filter */
891 for (n
= 0; n
< uf
.count
&& n
< FLT_EXACT_COUNT
; n
++)
892 memcpy(filter
->addr
[n
], addr
[n
].u
, ETH_ALEN
);
896 /* Remaining multicast addresses are hashed,
897 * unicast will leave the filter disabled. */
898 memset(filter
->mask
, 0, sizeof(filter
->mask
));
899 for (; n
< uf
.count
; n
++) {
900 if (!is_multicast_ether_addr(addr
[n
].u
)) {
901 err
= 0; /* no filter */
904 addr_hash_set(filter
->mask
, addr
[n
].u
);
907 /* For ALLMULTI just set the mask to all ones.
908 * This overrides the mask populated above. */
909 if ((uf
.flags
& TUN_FLT_ALLMULTI
))
910 memset(filter
->mask
, ~0, sizeof(filter
->mask
));
912 /* Now enable the filter */
914 filter
->count
= nexact
;
916 /* Return the number of exact filters */
923 /* Returns: 0 - drop, !=0 - accept */
924 static int run_filter(struct tap_filter
*filter
, const struct sk_buff
*skb
)
926 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
928 struct ethhdr
*eh
= (struct ethhdr
*) skb
->data
;
932 for (i
= 0; i
< filter
->count
; i
++)
933 if (ether_addr_equal(eh
->h_dest
, filter
->addr
[i
]))
936 /* Inexact match (multicast only) */
937 if (is_multicast_ether_addr(eh
->h_dest
))
938 return addr_hash_test(filter
->mask
, eh
->h_dest
);
944 * Checks whether the packet is accepted or not.
945 * Returns: 0 - drop, !=0 - accept
947 static int check_filter(struct tap_filter
*filter
, const struct sk_buff
*skb
)
952 return run_filter(filter
, skb
);
955 /* Network device part of the driver */
957 static const struct ethtool_ops tun_ethtool_ops
;
959 /* Net device detach from fd. */
960 static void tun_net_uninit(struct net_device
*dev
)
965 /* Net device open. */
966 static int tun_net_open(struct net_device
*dev
)
968 netif_tx_start_all_queues(dev
);
973 /* Net device close. */
974 static int tun_net_close(struct net_device
*dev
)
976 netif_tx_stop_all_queues(dev
);
980 /* Net device start xmit */
981 static void tun_automq_xmit(struct tun_struct
*tun
, struct sk_buff
*skb
)
984 if (tun
->numqueues
== 1 && static_branch_unlikely(&rps_needed
)) {
985 /* Select queue was not called for the skbuff, so we extract the
986 * RPS hash and save it into the flow_table here.
988 struct tun_flow_entry
*e
;
991 rxhash
= __skb_get_hash_symmetric(skb
);
992 e
= tun_flow_find(&tun
->flows
[tun_hashfn(rxhash
)], rxhash
);
994 tun_flow_save_rps_rxhash(e
, rxhash
);
999 static unsigned int run_ebpf_filter(struct tun_struct
*tun
,
1000 struct sk_buff
*skb
,
1003 struct tun_prog
*prog
= rcu_dereference(tun
->filter_prog
);
1006 len
= bpf_prog_run_clear_cb(prog
->prog
, skb
);
1011 /* Net device start xmit */
1012 static netdev_tx_t
tun_net_xmit(struct sk_buff
*skb
, struct net_device
*dev
)
1014 struct tun_struct
*tun
= netdev_priv(dev
);
1015 int txq
= skb
->queue_mapping
;
1016 struct tun_file
*tfile
;
1020 tfile
= rcu_dereference(tun
->tfiles
[txq
]);
1022 /* Drop packet if interface is not attached */
1026 if (!rcu_dereference(tun
->steering_prog
))
1027 tun_automq_xmit(tun
, skb
);
1029 netif_info(tun
, tx_queued
, tun
->dev
, "%s %d\n", __func__
, skb
->len
);
1031 /* Drop if the filter does not like it.
1032 * This is a noop if the filter is disabled.
1033 * Filter can be enabled only for the TAP devices. */
1034 if (!check_filter(&tun
->txflt
, skb
))
1037 if (tfile
->socket
.sk
->sk_filter
&&
1038 sk_filter(tfile
->socket
.sk
, skb
))
1041 len
= run_ebpf_filter(tun
, skb
, len
);
1042 if (len
== 0 || pskb_trim(skb
, len
))
1045 if (unlikely(skb_orphan_frags_rx(skb
, GFP_ATOMIC
)))
1048 skb_tx_timestamp(skb
);
1050 /* Orphan the skb - required as we might hang on to it
1051 * for indefinite time.
1057 if (ptr_ring_produce(&tfile
->tx_ring
, skb
))
1060 /* Notify and wake up reader process */
1061 if (tfile
->flags
& TUN_FASYNC
)
1062 kill_fasync(&tfile
->fasync
, SIGIO
, POLL_IN
);
1063 tfile
->socket
.sk
->sk_data_ready(tfile
->socket
.sk
);
1066 return NETDEV_TX_OK
;
1069 this_cpu_inc(tun
->pcpu_stats
->tx_dropped
);
1073 return NET_XMIT_DROP
;
1076 static void tun_net_mclist(struct net_device
*dev
)
1079 * This callback is supposed to deal with mc filter in
1080 * _rx_ path and has nothing to do with the _tx_ path.
1081 * In rx path we always accept everything userspace gives us.
1085 static netdev_features_t
tun_net_fix_features(struct net_device
*dev
,
1086 netdev_features_t features
)
1088 struct tun_struct
*tun
= netdev_priv(dev
);
1090 return (features
& tun
->set_features
) | (features
& ~TUN_USER_FEATURES
);
1093 static void tun_set_headroom(struct net_device
*dev
, int new_hr
)
1095 struct tun_struct
*tun
= netdev_priv(dev
);
1097 if (new_hr
< NET_SKB_PAD
)
1098 new_hr
= NET_SKB_PAD
;
1100 tun
->align
= new_hr
;
1104 tun_net_get_stats64(struct net_device
*dev
, struct rtnl_link_stats64
*stats
)
1106 u32 rx_dropped
= 0, tx_dropped
= 0, rx_frame_errors
= 0;
1107 struct tun_struct
*tun
= netdev_priv(dev
);
1108 struct tun_pcpu_stats
*p
;
1111 for_each_possible_cpu(i
) {
1112 u64 rxpackets
, rxbytes
, txpackets
, txbytes
;
1115 p
= per_cpu_ptr(tun
->pcpu_stats
, i
);
1117 start
= u64_stats_fetch_begin(&p
->syncp
);
1118 rxpackets
= u64_stats_read(&p
->rx_packets
);
1119 rxbytes
= u64_stats_read(&p
->rx_bytes
);
1120 txpackets
= u64_stats_read(&p
->tx_packets
);
1121 txbytes
= u64_stats_read(&p
->tx_bytes
);
1122 } while (u64_stats_fetch_retry(&p
->syncp
, start
));
1124 stats
->rx_packets
+= rxpackets
;
1125 stats
->rx_bytes
+= rxbytes
;
1126 stats
->tx_packets
+= txpackets
;
1127 stats
->tx_bytes
+= txbytes
;
1130 rx_dropped
+= p
->rx_dropped
;
1131 rx_frame_errors
+= p
->rx_frame_errors
;
1132 tx_dropped
+= p
->tx_dropped
;
1134 stats
->rx_dropped
= rx_dropped
;
1135 stats
->rx_frame_errors
= rx_frame_errors
;
1136 stats
->tx_dropped
= tx_dropped
;
1139 static int tun_xdp_set(struct net_device
*dev
, struct bpf_prog
*prog
,
1140 struct netlink_ext_ack
*extack
)
1142 struct tun_struct
*tun
= netdev_priv(dev
);
1143 struct tun_file
*tfile
;
1144 struct bpf_prog
*old_prog
;
1147 old_prog
= rtnl_dereference(tun
->xdp_prog
);
1148 rcu_assign_pointer(tun
->xdp_prog
, prog
);
1150 bpf_prog_put(old_prog
);
1152 for (i
= 0; i
< tun
->numqueues
; i
++) {
1153 tfile
= rtnl_dereference(tun
->tfiles
[i
]);
1155 sock_set_flag(&tfile
->sk
, SOCK_XDP
);
1157 sock_reset_flag(&tfile
->sk
, SOCK_XDP
);
1159 list_for_each_entry(tfile
, &tun
->disabled
, next
) {
1161 sock_set_flag(&tfile
->sk
, SOCK_XDP
);
1163 sock_reset_flag(&tfile
->sk
, SOCK_XDP
);
1169 static int tun_xdp(struct net_device
*dev
, struct netdev_bpf
*xdp
)
1171 switch (xdp
->command
) {
1172 case XDP_SETUP_PROG
:
1173 return tun_xdp_set(dev
, xdp
->prog
, xdp
->extack
);
1179 static int tun_net_change_carrier(struct net_device
*dev
, bool new_carrier
)
1182 struct tun_struct
*tun
= netdev_priv(dev
);
1184 if (!tun
->numqueues
)
1187 netif_carrier_on(dev
);
1189 netif_carrier_off(dev
);
1194 static const struct net_device_ops tun_netdev_ops
= {
1195 .ndo_uninit
= tun_net_uninit
,
1196 .ndo_open
= tun_net_open
,
1197 .ndo_stop
= tun_net_close
,
1198 .ndo_start_xmit
= tun_net_xmit
,
1199 .ndo_fix_features
= tun_net_fix_features
,
1200 .ndo_select_queue
= tun_select_queue
,
1201 .ndo_set_rx_headroom
= tun_set_headroom
,
1202 .ndo_get_stats64
= tun_net_get_stats64
,
1203 .ndo_change_carrier
= tun_net_change_carrier
,
1206 static void __tun_xdp_flush_tfile(struct tun_file
*tfile
)
1208 /* Notify and wake up reader process */
1209 if (tfile
->flags
& TUN_FASYNC
)
1210 kill_fasync(&tfile
->fasync
, SIGIO
, POLL_IN
);
1211 tfile
->socket
.sk
->sk_data_ready(tfile
->socket
.sk
);
1214 static int tun_xdp_xmit(struct net_device
*dev
, int n
,
1215 struct xdp_frame
**frames
, u32 flags
)
1217 struct tun_struct
*tun
= netdev_priv(dev
);
1218 struct tun_file
*tfile
;
1224 if (unlikely(flags
& ~XDP_XMIT_FLAGS_MASK
))
1230 numqueues
= READ_ONCE(tun
->numqueues
);
1233 return -ENXIO
; /* Caller will free/return all frames */
1236 tfile
= rcu_dereference(tun
->tfiles
[smp_processor_id() %
1238 if (unlikely(!tfile
))
1241 spin_lock(&tfile
->tx_ring
.producer_lock
);
1242 for (i
= 0; i
< n
; i
++) {
1243 struct xdp_frame
*xdp
= frames
[i
];
1244 /* Encode the XDP flag into lowest bit for consumer to differ
1245 * XDP buffer from sk_buff.
1247 void *frame
= tun_xdp_to_ptr(xdp
);
1249 if (__ptr_ring_produce(&tfile
->tx_ring
, frame
)) {
1250 this_cpu_inc(tun
->pcpu_stats
->tx_dropped
);
1251 xdp_return_frame_rx_napi(xdp
);
1255 spin_unlock(&tfile
->tx_ring
.producer_lock
);
1257 if (flags
& XDP_XMIT_FLUSH
)
1258 __tun_xdp_flush_tfile(tfile
);
1264 static int tun_xdp_tx(struct net_device
*dev
, struct xdp_buff
*xdp
)
1266 struct xdp_frame
*frame
= xdp_convert_buff_to_frame(xdp
);
1268 if (unlikely(!frame
))
1271 return tun_xdp_xmit(dev
, 1, &frame
, XDP_XMIT_FLUSH
);
1274 static const struct net_device_ops tap_netdev_ops
= {
1275 .ndo_uninit
= tun_net_uninit
,
1276 .ndo_open
= tun_net_open
,
1277 .ndo_stop
= tun_net_close
,
1278 .ndo_start_xmit
= tun_net_xmit
,
1279 .ndo_fix_features
= tun_net_fix_features
,
1280 .ndo_set_rx_mode
= tun_net_mclist
,
1281 .ndo_set_mac_address
= eth_mac_addr
,
1282 .ndo_validate_addr
= eth_validate_addr
,
1283 .ndo_select_queue
= tun_select_queue
,
1284 .ndo_features_check
= passthru_features_check
,
1285 .ndo_set_rx_headroom
= tun_set_headroom
,
1286 .ndo_get_stats64
= tun_net_get_stats64
,
1288 .ndo_xdp_xmit
= tun_xdp_xmit
,
1289 .ndo_change_carrier
= tun_net_change_carrier
,
1292 static void tun_flow_init(struct tun_struct
*tun
)
1296 for (i
= 0; i
< TUN_NUM_FLOW_ENTRIES
; i
++)
1297 INIT_HLIST_HEAD(&tun
->flows
[i
]);
1299 tun
->ageing_time
= TUN_FLOW_EXPIRE
;
1300 timer_setup(&tun
->flow_gc_timer
, tun_flow_cleanup
, 0);
1301 mod_timer(&tun
->flow_gc_timer
,
1302 round_jiffies_up(jiffies
+ tun
->ageing_time
));
1305 static void tun_flow_uninit(struct tun_struct
*tun
)
1307 del_timer_sync(&tun
->flow_gc_timer
);
1308 tun_flow_flush(tun
);
1312 #define MAX_MTU 65535
1314 /* Initialize net device. */
1315 static void tun_net_init(struct net_device
*dev
)
1317 struct tun_struct
*tun
= netdev_priv(dev
);
1319 switch (tun
->flags
& TUN_TYPE_MASK
) {
1321 dev
->netdev_ops
= &tun_netdev_ops
;
1322 dev
->header_ops
= &ip_tunnel_header_ops
;
1324 /* Point-to-Point TUN Device */
1325 dev
->hard_header_len
= 0;
1329 /* Zero header length */
1330 dev
->type
= ARPHRD_NONE
;
1331 dev
->flags
= IFF_POINTOPOINT
| IFF_NOARP
| IFF_MULTICAST
;
1335 dev
->netdev_ops
= &tap_netdev_ops
;
1336 /* Ethernet TAP Device */
1338 dev
->priv_flags
&= ~IFF_TX_SKB_SHARING
;
1339 dev
->priv_flags
|= IFF_LIVE_ADDR_CHANGE
;
1341 eth_hw_addr_random(dev
);
1346 dev
->min_mtu
= MIN_MTU
;
1347 dev
->max_mtu
= MAX_MTU
- dev
->hard_header_len
;
1350 static bool tun_sock_writeable(struct tun_struct
*tun
, struct tun_file
*tfile
)
1352 struct sock
*sk
= tfile
->socket
.sk
;
1354 return (tun
->dev
->flags
& IFF_UP
) && sock_writeable(sk
);
1357 /* Character device part */
1360 static __poll_t
tun_chr_poll(struct file
*file
, poll_table
*wait
)
1362 struct tun_file
*tfile
= file
->private_data
;
1363 struct tun_struct
*tun
= tun_get(tfile
);
1370 sk
= tfile
->socket
.sk
;
1372 poll_wait(file
, sk_sleep(sk
), wait
);
1374 if (!ptr_ring_empty(&tfile
->tx_ring
))
1375 mask
|= EPOLLIN
| EPOLLRDNORM
;
1377 /* Make sure SOCKWQ_ASYNC_NOSPACE is set if not writable to
1378 * guarantee EPOLLOUT to be raised by either here or
1379 * tun_sock_write_space(). Then process could get notification
1380 * after it writes to a down device and meets -EIO.
1382 if (tun_sock_writeable(tun
, tfile
) ||
1383 (!test_and_set_bit(SOCKWQ_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
) &&
1384 tun_sock_writeable(tun
, tfile
)))
1385 mask
|= EPOLLOUT
| EPOLLWRNORM
;
1387 if (tun
->dev
->reg_state
!= NETREG_REGISTERED
)
1394 static struct sk_buff
*tun_napi_alloc_frags(struct tun_file
*tfile
,
1396 const struct iov_iter
*it
)
1398 struct sk_buff
*skb
;
1403 if (it
->nr_segs
> MAX_SKB_FRAGS
+ 1)
1404 return ERR_PTR(-ENOMEM
);
1407 skb
= napi_get_frags(&tfile
->napi
);
1410 return ERR_PTR(-ENOMEM
);
1412 linear
= iov_iter_single_seg_count(it
);
1413 err
= __skb_grow(skb
, linear
);
1418 skb
->data_len
= len
- linear
;
1419 skb
->truesize
+= skb
->data_len
;
1421 for (i
= 1; i
< it
->nr_segs
; i
++) {
1422 size_t fragsz
= it
->iov
[i
].iov_len
;
1426 if (fragsz
== 0 || fragsz
> PAGE_SIZE
) {
1430 frag
= netdev_alloc_frag(fragsz
);
1435 page
= virt_to_head_page(frag
);
1436 skb_fill_page_desc(skb
, i
- 1, page
,
1437 frag
- page_address(page
), fragsz
);
1442 /* frees skb and all frags allocated with napi_alloc_frag() */
1443 napi_free_frags(&tfile
->napi
);
1444 return ERR_PTR(err
);
1447 /* prepad is the amount to reserve at front. len is length after that.
1448 * linear is a hint as to how much to copy (usually headers). */
1449 static struct sk_buff
*tun_alloc_skb(struct tun_file
*tfile
,
1450 size_t prepad
, size_t len
,
1451 size_t linear
, int noblock
)
1453 struct sock
*sk
= tfile
->socket
.sk
;
1454 struct sk_buff
*skb
;
1457 /* Under a page? Don't bother with paged skb. */
1458 if (prepad
+ len
< PAGE_SIZE
|| !linear
)
1461 skb
= sock_alloc_send_pskb(sk
, prepad
+ linear
, len
- linear
, noblock
,
1464 return ERR_PTR(err
);
1466 skb_reserve(skb
, prepad
);
1467 skb_put(skb
, linear
);
1468 skb
->data_len
= len
- linear
;
1469 skb
->len
+= len
- linear
;
1474 static void tun_rx_batched(struct tun_struct
*tun
, struct tun_file
*tfile
,
1475 struct sk_buff
*skb
, int more
)
1477 struct sk_buff_head
*queue
= &tfile
->sk
.sk_write_queue
;
1478 struct sk_buff_head process_queue
;
1479 u32 rx_batched
= tun
->rx_batched
;
1482 if (!rx_batched
|| (!more
&& skb_queue_empty(queue
))) {
1484 skb_record_rx_queue(skb
, tfile
->queue_index
);
1485 netif_receive_skb(skb
);
1490 spin_lock(&queue
->lock
);
1491 if (!more
|| skb_queue_len(queue
) == rx_batched
) {
1492 __skb_queue_head_init(&process_queue
);
1493 skb_queue_splice_tail_init(queue
, &process_queue
);
1496 __skb_queue_tail(queue
, skb
);
1498 spin_unlock(&queue
->lock
);
1501 struct sk_buff
*nskb
;
1504 while ((nskb
= __skb_dequeue(&process_queue
))) {
1505 skb_record_rx_queue(nskb
, tfile
->queue_index
);
1506 netif_receive_skb(nskb
);
1508 skb_record_rx_queue(skb
, tfile
->queue_index
);
1509 netif_receive_skb(skb
);
1514 static bool tun_can_build_skb(struct tun_struct
*tun
, struct tun_file
*tfile
,
1515 int len
, int noblock
, bool zerocopy
)
1517 if ((tun
->flags
& TUN_TYPE_MASK
) != IFF_TAP
)
1520 if (tfile
->socket
.sk
->sk_sndbuf
!= INT_MAX
)
1529 if (SKB_DATA_ALIGN(len
+ TUN_RX_PAD
) +
1530 SKB_DATA_ALIGN(sizeof(struct skb_shared_info
)) > PAGE_SIZE
)
1536 static struct sk_buff
*__tun_build_skb(struct tun_file
*tfile
,
1537 struct page_frag
*alloc_frag
, char *buf
,
1538 int buflen
, int len
, int pad
)
1540 struct sk_buff
*skb
= build_skb(buf
, buflen
);
1543 return ERR_PTR(-ENOMEM
);
1545 skb_reserve(skb
, pad
);
1547 skb_set_owner_w(skb
, tfile
->socket
.sk
);
1549 get_page(alloc_frag
->page
);
1550 alloc_frag
->offset
+= buflen
;
1555 static int tun_xdp_act(struct tun_struct
*tun
, struct bpf_prog
*xdp_prog
,
1556 struct xdp_buff
*xdp
, u32 act
)
1562 err
= xdp_do_redirect(tun
->dev
, xdp
, xdp_prog
);
1567 err
= tun_xdp_tx(tun
->dev
, xdp
);
1574 bpf_warn_invalid_xdp_action(act
);
1577 trace_xdp_exception(tun
->dev
, xdp_prog
, act
);
1580 this_cpu_inc(tun
->pcpu_stats
->rx_dropped
);
1587 static struct sk_buff
*tun_build_skb(struct tun_struct
*tun
,
1588 struct tun_file
*tfile
,
1589 struct iov_iter
*from
,
1590 struct virtio_net_hdr
*hdr
,
1591 int len
, int *skb_xdp
)
1593 struct page_frag
*alloc_frag
= ¤t
->task_frag
;
1594 struct bpf_prog
*xdp_prog
;
1595 int buflen
= SKB_DATA_ALIGN(sizeof(struct skb_shared_info
));
1598 int pad
= TUN_RX_PAD
;
1602 xdp_prog
= rcu_dereference(tun
->xdp_prog
);
1604 pad
+= XDP_PACKET_HEADROOM
;
1605 buflen
+= SKB_DATA_ALIGN(len
+ pad
);
1608 alloc_frag
->offset
= ALIGN((u64
)alloc_frag
->offset
, SMP_CACHE_BYTES
);
1609 if (unlikely(!skb_page_frag_refill(buflen
, alloc_frag
, GFP_KERNEL
)))
1610 return ERR_PTR(-ENOMEM
);
1612 buf
= (char *)page_address(alloc_frag
->page
) + alloc_frag
->offset
;
1613 copied
= copy_page_from_iter(alloc_frag
->page
,
1614 alloc_frag
->offset
+ pad
,
1617 return ERR_PTR(-EFAULT
);
1619 /* There's a small window that XDP may be set after the check
1620 * of xdp_prog above, this should be rare and for simplicity
1621 * we do XDP on skb in case the headroom is not enough.
1623 if (hdr
->gso_type
|| !xdp_prog
) {
1625 return __tun_build_skb(tfile
, alloc_frag
, buf
, buflen
, len
,
1633 xdp_prog
= rcu_dereference(tun
->xdp_prog
);
1635 struct xdp_buff xdp
;
1638 xdp
.data_hard_start
= buf
;
1639 xdp
.data
= buf
+ pad
;
1640 xdp_set_data_meta_invalid(&xdp
);
1641 xdp
.data_end
= xdp
.data
+ len
;
1642 xdp
.rxq
= &tfile
->xdp_rxq
;
1643 xdp
.frame_sz
= buflen
;
1645 act
= bpf_prog_run_xdp(xdp_prog
, &xdp
);
1646 if (act
== XDP_REDIRECT
|| act
== XDP_TX
) {
1647 get_page(alloc_frag
->page
);
1648 alloc_frag
->offset
+= buflen
;
1650 err
= tun_xdp_act(tun
, xdp_prog
, &xdp
, act
);
1652 if (act
== XDP_REDIRECT
|| act
== XDP_TX
)
1653 put_page(alloc_frag
->page
);
1657 if (err
== XDP_REDIRECT
)
1659 if (err
!= XDP_PASS
)
1662 pad
= xdp
.data
- xdp
.data_hard_start
;
1663 len
= xdp
.data_end
- xdp
.data
;
1668 return __tun_build_skb(tfile
, alloc_frag
, buf
, buflen
, len
, pad
);
1676 /* Get packet from user space buffer */
1677 static ssize_t
tun_get_user(struct tun_struct
*tun
, struct tun_file
*tfile
,
1678 void *msg_control
, struct iov_iter
*from
,
1679 int noblock
, bool more
)
1681 struct tun_pi pi
= { 0, cpu_to_be16(ETH_P_IP
) };
1682 struct sk_buff
*skb
;
1683 size_t total_len
= iov_iter_count(from
);
1684 size_t len
= total_len
, align
= tun
->align
, linear
;
1685 struct virtio_net_hdr gso
= { 0 };
1686 struct tun_pcpu_stats
*stats
;
1689 bool zerocopy
= false;
1693 bool frags
= tun_napi_frags_enabled(tfile
);
1695 if (!(tun
->flags
& IFF_NO_PI
)) {
1696 if (len
< sizeof(pi
))
1700 if (!copy_from_iter_full(&pi
, sizeof(pi
), from
))
1704 if (tun
->flags
& IFF_VNET_HDR
) {
1705 int vnet_hdr_sz
= READ_ONCE(tun
->vnet_hdr_sz
);
1707 if (len
< vnet_hdr_sz
)
1711 if (!copy_from_iter_full(&gso
, sizeof(gso
), from
))
1714 if ((gso
.flags
& VIRTIO_NET_HDR_F_NEEDS_CSUM
) &&
1715 tun16_to_cpu(tun
, gso
.csum_start
) + tun16_to_cpu(tun
, gso
.csum_offset
) + 2 > tun16_to_cpu(tun
, gso
.hdr_len
))
1716 gso
.hdr_len
= cpu_to_tun16(tun
, tun16_to_cpu(tun
, gso
.csum_start
) + tun16_to_cpu(tun
, gso
.csum_offset
) + 2);
1718 if (tun16_to_cpu(tun
, gso
.hdr_len
) > len
)
1720 iov_iter_advance(from
, vnet_hdr_sz
- sizeof(gso
));
1723 if ((tun
->flags
& TUN_TYPE_MASK
) == IFF_TAP
) {
1724 align
+= NET_IP_ALIGN
;
1725 if (unlikely(len
< ETH_HLEN
||
1726 (gso
.hdr_len
&& tun16_to_cpu(tun
, gso
.hdr_len
) < ETH_HLEN
)))
1730 good_linear
= SKB_MAX_HEAD(align
);
1733 struct iov_iter i
= *from
;
1735 /* There are 256 bytes to be copied in skb, so there is
1736 * enough room for skb expand head in case it is used.
1737 * The rest of the buffer is mapped from userspace.
1739 copylen
= gso
.hdr_len
? tun16_to_cpu(tun
, gso
.hdr_len
) : GOODCOPY_LEN
;
1740 if (copylen
> good_linear
)
1741 copylen
= good_linear
;
1743 iov_iter_advance(&i
, copylen
);
1744 if (iov_iter_npages(&i
, INT_MAX
) <= MAX_SKB_FRAGS
)
1748 if (!frags
&& tun_can_build_skb(tun
, tfile
, len
, noblock
, zerocopy
)) {
1749 /* For the packet that is not easy to be processed
1750 * (e.g gso or jumbo packet), we will do it at after
1751 * skb was created with generic XDP routine.
1753 skb
= tun_build_skb(tun
, tfile
, from
, &gso
, len
, &skb_xdp
);
1755 this_cpu_inc(tun
->pcpu_stats
->rx_dropped
);
1756 return PTR_ERR(skb
);
1763 if (tun16_to_cpu(tun
, gso
.hdr_len
) > good_linear
)
1764 linear
= good_linear
;
1766 linear
= tun16_to_cpu(tun
, gso
.hdr_len
);
1770 mutex_lock(&tfile
->napi_mutex
);
1771 skb
= tun_napi_alloc_frags(tfile
, copylen
, from
);
1772 /* tun_napi_alloc_frags() enforces a layout for the skb.
1773 * If zerocopy is enabled, then this layout will be
1774 * overwritten by zerocopy_sg_from_iter().
1778 skb
= tun_alloc_skb(tfile
, align
, copylen
, linear
,
1783 if (PTR_ERR(skb
) != -EAGAIN
)
1784 this_cpu_inc(tun
->pcpu_stats
->rx_dropped
);
1786 mutex_unlock(&tfile
->napi_mutex
);
1787 return PTR_ERR(skb
);
1791 err
= zerocopy_sg_from_iter(skb
, from
);
1793 err
= skb_copy_datagram_from_iter(skb
, 0, from
, len
);
1798 this_cpu_inc(tun
->pcpu_stats
->rx_dropped
);
1801 tfile
->napi
.skb
= NULL
;
1802 mutex_unlock(&tfile
->napi_mutex
);
1809 if (virtio_net_hdr_to_skb(skb
, &gso
, tun_is_little_endian(tun
))) {
1810 this_cpu_inc(tun
->pcpu_stats
->rx_frame_errors
);
1813 tfile
->napi
.skb
= NULL
;
1814 mutex_unlock(&tfile
->napi_mutex
);
1820 switch (tun
->flags
& TUN_TYPE_MASK
) {
1822 if (tun
->flags
& IFF_NO_PI
) {
1823 u8 ip_version
= skb
->len
? (skb
->data
[0] >> 4) : 0;
1825 switch (ip_version
) {
1827 pi
.proto
= htons(ETH_P_IP
);
1830 pi
.proto
= htons(ETH_P_IPV6
);
1833 this_cpu_inc(tun
->pcpu_stats
->rx_dropped
);
1839 skb_reset_mac_header(skb
);
1840 skb
->protocol
= pi
.proto
;
1841 skb
->dev
= tun
->dev
;
1844 if (frags
&& !pskb_may_pull(skb
, ETH_HLEN
)) {
1848 skb
->protocol
= eth_type_trans(skb
, tun
->dev
);
1852 /* copy skb_ubuf_info for callback when skb has no error */
1854 skb_shinfo(skb
)->destructor_arg
= msg_control
;
1855 skb_shinfo(skb
)->tx_flags
|= SKBTX_DEV_ZEROCOPY
;
1856 skb_shinfo(skb
)->tx_flags
|= SKBTX_SHARED_FRAG
;
1857 } else if (msg_control
) {
1858 struct ubuf_info
*uarg
= msg_control
;
1859 uarg
->callback(uarg
, false);
1862 skb_reset_network_header(skb
);
1863 skb_probe_transport_header(skb
);
1864 skb_record_rx_queue(skb
, tfile
->queue_index
);
1867 struct bpf_prog
*xdp_prog
;
1872 xdp_prog
= rcu_dereference(tun
->xdp_prog
);
1874 ret
= do_xdp_generic(xdp_prog
, skb
);
1875 if (ret
!= XDP_PASS
) {
1879 tfile
->napi
.skb
= NULL
;
1880 mutex_unlock(&tfile
->napi_mutex
);
1889 /* Compute the costly rx hash only if needed for flow updates.
1890 * We may get a very small possibility of OOO during switching, not
1891 * worth to optimize.
1893 if (!rcu_access_pointer(tun
->steering_prog
) && tun
->numqueues
> 1 &&
1895 rxhash
= __skb_get_hash_symmetric(skb
);
1898 if (unlikely(!(tun
->dev
->flags
& IFF_UP
))) {
1907 /* Exercise flow dissector code path. */
1908 skb_push(skb
, ETH_HLEN
);
1909 headlen
= eth_get_headlen(tun
->dev
, skb
->data
,
1912 if (unlikely(headlen
> skb_headlen(skb
))) {
1913 this_cpu_inc(tun
->pcpu_stats
->rx_dropped
);
1914 napi_free_frags(&tfile
->napi
);
1916 mutex_unlock(&tfile
->napi_mutex
);
1922 napi_gro_frags(&tfile
->napi
);
1924 mutex_unlock(&tfile
->napi_mutex
);
1925 } else if (tfile
->napi_enabled
) {
1926 struct sk_buff_head
*queue
= &tfile
->sk
.sk_write_queue
;
1929 spin_lock_bh(&queue
->lock
);
1930 __skb_queue_tail(queue
, skb
);
1931 queue_len
= skb_queue_len(queue
);
1932 spin_unlock(&queue
->lock
);
1934 if (!more
|| queue_len
> NAPI_POLL_WEIGHT
)
1935 napi_schedule(&tfile
->napi
);
1938 } else if (!IS_ENABLED(CONFIG_4KSTACKS
)) {
1939 tun_rx_batched(tun
, tfile
, skb
, more
);
1945 stats
= get_cpu_ptr(tun
->pcpu_stats
);
1946 u64_stats_update_begin(&stats
->syncp
);
1947 u64_stats_inc(&stats
->rx_packets
);
1948 u64_stats_add(&stats
->rx_bytes
, len
);
1949 u64_stats_update_end(&stats
->syncp
);
1953 tun_flow_update(tun
, rxhash
, tfile
);
1958 static ssize_t
tun_chr_write_iter(struct kiocb
*iocb
, struct iov_iter
*from
)
1960 struct file
*file
= iocb
->ki_filp
;
1961 struct tun_file
*tfile
= file
->private_data
;
1962 struct tun_struct
*tun
= tun_get(tfile
);
1968 result
= tun_get_user(tun
, tfile
, NULL
, from
,
1969 file
->f_flags
& O_NONBLOCK
, false);
1975 static ssize_t
tun_put_user_xdp(struct tun_struct
*tun
,
1976 struct tun_file
*tfile
,
1977 struct xdp_frame
*xdp_frame
,
1978 struct iov_iter
*iter
)
1980 int vnet_hdr_sz
= 0;
1981 size_t size
= xdp_frame
->len
;
1982 struct tun_pcpu_stats
*stats
;
1985 if (tun
->flags
& IFF_VNET_HDR
) {
1986 struct virtio_net_hdr gso
= { 0 };
1988 vnet_hdr_sz
= READ_ONCE(tun
->vnet_hdr_sz
);
1989 if (unlikely(iov_iter_count(iter
) < vnet_hdr_sz
))
1991 if (unlikely(copy_to_iter(&gso
, sizeof(gso
), iter
) !=
1994 iov_iter_advance(iter
, vnet_hdr_sz
- sizeof(gso
));
1997 ret
= copy_to_iter(xdp_frame
->data
, size
, iter
) + vnet_hdr_sz
;
1999 stats
= get_cpu_ptr(tun
->pcpu_stats
);
2000 u64_stats_update_begin(&stats
->syncp
);
2001 u64_stats_inc(&stats
->tx_packets
);
2002 u64_stats_add(&stats
->tx_bytes
, ret
);
2003 u64_stats_update_end(&stats
->syncp
);
2004 put_cpu_ptr(tun
->pcpu_stats
);
2009 /* Put packet to the user space buffer */
2010 static ssize_t
tun_put_user(struct tun_struct
*tun
,
2011 struct tun_file
*tfile
,
2012 struct sk_buff
*skb
,
2013 struct iov_iter
*iter
)
2015 struct tun_pi pi
= { 0, skb
->protocol
};
2016 struct tun_pcpu_stats
*stats
;
2018 int vlan_offset
= 0;
2020 int vnet_hdr_sz
= 0;
2022 if (skb_vlan_tag_present(skb
))
2023 vlan_hlen
= VLAN_HLEN
;
2025 if (tun
->flags
& IFF_VNET_HDR
)
2026 vnet_hdr_sz
= READ_ONCE(tun
->vnet_hdr_sz
);
2028 total
= skb
->len
+ vlan_hlen
+ vnet_hdr_sz
;
2030 if (!(tun
->flags
& IFF_NO_PI
)) {
2031 if (iov_iter_count(iter
) < sizeof(pi
))
2034 total
+= sizeof(pi
);
2035 if (iov_iter_count(iter
) < total
) {
2036 /* Packet will be striped */
2037 pi
.flags
|= TUN_PKT_STRIP
;
2040 if (copy_to_iter(&pi
, sizeof(pi
), iter
) != sizeof(pi
))
2045 struct virtio_net_hdr gso
;
2047 if (iov_iter_count(iter
) < vnet_hdr_sz
)
2050 if (virtio_net_hdr_from_skb(skb
, &gso
,
2051 tun_is_little_endian(tun
), true,
2053 struct skb_shared_info
*sinfo
= skb_shinfo(skb
);
2054 pr_err("unexpected GSO type: "
2055 "0x%x, gso_size %d, hdr_len %d\n",
2056 sinfo
->gso_type
, tun16_to_cpu(tun
, gso
.gso_size
),
2057 tun16_to_cpu(tun
, gso
.hdr_len
));
2058 print_hex_dump(KERN_ERR
, "tun: ",
2061 min((int)tun16_to_cpu(tun
, gso
.hdr_len
), 64), true);
2066 if (copy_to_iter(&gso
, sizeof(gso
), iter
) != sizeof(gso
))
2069 iov_iter_advance(iter
, vnet_hdr_sz
- sizeof(gso
));
2076 veth
.h_vlan_proto
= skb
->vlan_proto
;
2077 veth
.h_vlan_TCI
= htons(skb_vlan_tag_get(skb
));
2079 vlan_offset
= offsetof(struct vlan_ethhdr
, h_vlan_proto
);
2081 ret
= skb_copy_datagram_iter(skb
, 0, iter
, vlan_offset
);
2082 if (ret
|| !iov_iter_count(iter
))
2085 ret
= copy_to_iter(&veth
, sizeof(veth
), iter
);
2086 if (ret
!= sizeof(veth
) || !iov_iter_count(iter
))
2090 skb_copy_datagram_iter(skb
, vlan_offset
, iter
, skb
->len
- vlan_offset
);
2093 /* caller is in process context, */
2094 stats
= get_cpu_ptr(tun
->pcpu_stats
);
2095 u64_stats_update_begin(&stats
->syncp
);
2096 u64_stats_inc(&stats
->tx_packets
);
2097 u64_stats_add(&stats
->tx_bytes
, skb
->len
+ vlan_hlen
);
2098 u64_stats_update_end(&stats
->syncp
);
2099 put_cpu_ptr(tun
->pcpu_stats
);
2104 static void *tun_ring_recv(struct tun_file
*tfile
, int noblock
, int *err
)
2106 DECLARE_WAITQUEUE(wait
, current
);
2110 ptr
= ptr_ring_consume(&tfile
->tx_ring
);
2118 add_wait_queue(&tfile
->socket
.wq
.wait
, &wait
);
2121 set_current_state(TASK_INTERRUPTIBLE
);
2122 ptr
= ptr_ring_consume(&tfile
->tx_ring
);
2125 if (signal_pending(current
)) {
2126 error
= -ERESTARTSYS
;
2129 if (tfile
->socket
.sk
->sk_shutdown
& RCV_SHUTDOWN
) {
2137 __set_current_state(TASK_RUNNING
);
2138 remove_wait_queue(&tfile
->socket
.wq
.wait
, &wait
);
2145 static ssize_t
tun_do_read(struct tun_struct
*tun
, struct tun_file
*tfile
,
2146 struct iov_iter
*to
,
2147 int noblock
, void *ptr
)
2152 if (!iov_iter_count(to
)) {
2158 /* Read frames from ring */
2159 ptr
= tun_ring_recv(tfile
, noblock
, &err
);
2164 if (tun_is_xdp_frame(ptr
)) {
2165 struct xdp_frame
*xdpf
= tun_ptr_to_xdp(ptr
);
2167 ret
= tun_put_user_xdp(tun
, tfile
, xdpf
, to
);
2168 xdp_return_frame(xdpf
);
2170 struct sk_buff
*skb
= ptr
;
2172 ret
= tun_put_user(tun
, tfile
, skb
, to
);
2173 if (unlikely(ret
< 0))
2182 static ssize_t
tun_chr_read_iter(struct kiocb
*iocb
, struct iov_iter
*to
)
2184 struct file
*file
= iocb
->ki_filp
;
2185 struct tun_file
*tfile
= file
->private_data
;
2186 struct tun_struct
*tun
= tun_get(tfile
);
2187 ssize_t len
= iov_iter_count(to
), ret
;
2191 ret
= tun_do_read(tun
, tfile
, to
, file
->f_flags
& O_NONBLOCK
, NULL
);
2192 ret
= min_t(ssize_t
, ret
, len
);
2199 static void tun_prog_free(struct rcu_head
*rcu
)
2201 struct tun_prog
*prog
= container_of(rcu
, struct tun_prog
, rcu
);
2203 bpf_prog_destroy(prog
->prog
);
2207 static int __tun_set_ebpf(struct tun_struct
*tun
,
2208 struct tun_prog __rcu
**prog_p
,
2209 struct bpf_prog
*prog
)
2211 struct tun_prog
*old
, *new = NULL
;
2214 new = kmalloc(sizeof(*new), GFP_KERNEL
);
2220 spin_lock_bh(&tun
->lock
);
2221 old
= rcu_dereference_protected(*prog_p
,
2222 lockdep_is_held(&tun
->lock
));
2223 rcu_assign_pointer(*prog_p
, new);
2224 spin_unlock_bh(&tun
->lock
);
2227 call_rcu(&old
->rcu
, tun_prog_free
);
2232 static void tun_free_netdev(struct net_device
*dev
)
2234 struct tun_struct
*tun
= netdev_priv(dev
);
2236 BUG_ON(!(list_empty(&tun
->disabled
)));
2238 free_percpu(tun
->pcpu_stats
);
2239 /* We clear pcpu_stats so that tun_set_iff() can tell if
2240 * tun_free_netdev() has been called from register_netdevice().
2242 tun
->pcpu_stats
= NULL
;
2244 tun_flow_uninit(tun
);
2245 security_tun_dev_free_security(tun
->security
);
2246 __tun_set_ebpf(tun
, &tun
->steering_prog
, NULL
);
2247 __tun_set_ebpf(tun
, &tun
->filter_prog
, NULL
);
2250 static void tun_setup(struct net_device
*dev
)
2252 struct tun_struct
*tun
= netdev_priv(dev
);
2254 tun
->owner
= INVALID_UID
;
2255 tun
->group
= INVALID_GID
;
2256 tun_default_link_ksettings(dev
, &tun
->link_ksettings
);
2258 dev
->ethtool_ops
= &tun_ethtool_ops
;
2259 dev
->needs_free_netdev
= true;
2260 dev
->priv_destructor
= tun_free_netdev
;
2261 /* We prefer our own queue length */
2262 dev
->tx_queue_len
= TUN_READQ_SIZE
;
2265 /* Trivial set of netlink ops to allow deleting tun or tap
2266 * device with netlink.
2268 static int tun_validate(struct nlattr
*tb
[], struct nlattr
*data
[],
2269 struct netlink_ext_ack
*extack
)
2271 NL_SET_ERR_MSG(extack
,
2272 "tun/tap creation via rtnetlink is not supported.");
2276 static size_t tun_get_size(const struct net_device
*dev
)
2278 BUILD_BUG_ON(sizeof(u32
) != sizeof(uid_t
));
2279 BUILD_BUG_ON(sizeof(u32
) != sizeof(gid_t
));
2281 return nla_total_size(sizeof(uid_t
)) + /* OWNER */
2282 nla_total_size(sizeof(gid_t
)) + /* GROUP */
2283 nla_total_size(sizeof(u8
)) + /* TYPE */
2284 nla_total_size(sizeof(u8
)) + /* PI */
2285 nla_total_size(sizeof(u8
)) + /* VNET_HDR */
2286 nla_total_size(sizeof(u8
)) + /* PERSIST */
2287 nla_total_size(sizeof(u8
)) + /* MULTI_QUEUE */
2288 nla_total_size(sizeof(u32
)) + /* NUM_QUEUES */
2289 nla_total_size(sizeof(u32
)) + /* NUM_DISABLED_QUEUES */
2293 static int tun_fill_info(struct sk_buff
*skb
, const struct net_device
*dev
)
2295 struct tun_struct
*tun
= netdev_priv(dev
);
2297 if (nla_put_u8(skb
, IFLA_TUN_TYPE
, tun
->flags
& TUN_TYPE_MASK
))
2298 goto nla_put_failure
;
2299 if (uid_valid(tun
->owner
) &&
2300 nla_put_u32(skb
, IFLA_TUN_OWNER
,
2301 from_kuid_munged(current_user_ns(), tun
->owner
)))
2302 goto nla_put_failure
;
2303 if (gid_valid(tun
->group
) &&
2304 nla_put_u32(skb
, IFLA_TUN_GROUP
,
2305 from_kgid_munged(current_user_ns(), tun
->group
)))
2306 goto nla_put_failure
;
2307 if (nla_put_u8(skb
, IFLA_TUN_PI
, !(tun
->flags
& IFF_NO_PI
)))
2308 goto nla_put_failure
;
2309 if (nla_put_u8(skb
, IFLA_TUN_VNET_HDR
, !!(tun
->flags
& IFF_VNET_HDR
)))
2310 goto nla_put_failure
;
2311 if (nla_put_u8(skb
, IFLA_TUN_PERSIST
, !!(tun
->flags
& IFF_PERSIST
)))
2312 goto nla_put_failure
;
2313 if (nla_put_u8(skb
, IFLA_TUN_MULTI_QUEUE
,
2314 !!(tun
->flags
& IFF_MULTI_QUEUE
)))
2315 goto nla_put_failure
;
2316 if (tun
->flags
& IFF_MULTI_QUEUE
) {
2317 if (nla_put_u32(skb
, IFLA_TUN_NUM_QUEUES
, tun
->numqueues
))
2318 goto nla_put_failure
;
2319 if (nla_put_u32(skb
, IFLA_TUN_NUM_DISABLED_QUEUES
,
2321 goto nla_put_failure
;
2330 static struct rtnl_link_ops tun_link_ops __read_mostly
= {
2332 .priv_size
= sizeof(struct tun_struct
),
2334 .validate
= tun_validate
,
2335 .get_size
= tun_get_size
,
2336 .fill_info
= tun_fill_info
,
2339 static void tun_sock_write_space(struct sock
*sk
)
2341 struct tun_file
*tfile
;
2342 wait_queue_head_t
*wqueue
;
2344 if (!sock_writeable(sk
))
2347 if (!test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE
, &sk
->sk_socket
->flags
))
2350 wqueue
= sk_sleep(sk
);
2351 if (wqueue
&& waitqueue_active(wqueue
))
2352 wake_up_interruptible_sync_poll(wqueue
, EPOLLOUT
|
2353 EPOLLWRNORM
| EPOLLWRBAND
);
2355 tfile
= container_of(sk
, struct tun_file
, sk
);
2356 kill_fasync(&tfile
->fasync
, SIGIO
, POLL_OUT
);
2359 static void tun_put_page(struct tun_page
*tpage
)
2362 __page_frag_cache_drain(tpage
->page
, tpage
->count
);
2365 static int tun_xdp_one(struct tun_struct
*tun
,
2366 struct tun_file
*tfile
,
2367 struct xdp_buff
*xdp
, int *flush
,
2368 struct tun_page
*tpage
)
2370 unsigned int datasize
= xdp
->data_end
- xdp
->data
;
2371 struct tun_xdp_hdr
*hdr
= xdp
->data_hard_start
;
2372 struct virtio_net_hdr
*gso
= &hdr
->gso
;
2373 struct tun_pcpu_stats
*stats
;
2374 struct bpf_prog
*xdp_prog
;
2375 struct sk_buff
*skb
= NULL
;
2376 u32 rxhash
= 0, act
;
2377 int buflen
= hdr
->buflen
;
2379 bool skb_xdp
= false;
2382 xdp_prog
= rcu_dereference(tun
->xdp_prog
);
2384 if (gso
->gso_type
) {
2388 xdp_set_data_meta_invalid(xdp
);
2389 xdp
->rxq
= &tfile
->xdp_rxq
;
2390 xdp
->frame_sz
= buflen
;
2392 act
= bpf_prog_run_xdp(xdp_prog
, xdp
);
2393 err
= tun_xdp_act(tun
, xdp_prog
, xdp
, act
);
2395 put_page(virt_to_head_page(xdp
->data
));
2408 page
= virt_to_head_page(xdp
->data
);
2409 if (tpage
->page
== page
) {
2412 tun_put_page(tpage
);
2421 skb
= build_skb(xdp
->data_hard_start
, buflen
);
2427 skb_reserve(skb
, xdp
->data
- xdp
->data_hard_start
);
2428 skb_put(skb
, xdp
->data_end
- xdp
->data
);
2430 if (virtio_net_hdr_to_skb(skb
, gso
, tun_is_little_endian(tun
))) {
2431 this_cpu_inc(tun
->pcpu_stats
->rx_frame_errors
);
2437 skb
->protocol
= eth_type_trans(skb
, tun
->dev
);
2438 skb_reset_network_header(skb
);
2439 skb_probe_transport_header(skb
);
2440 skb_record_rx_queue(skb
, tfile
->queue_index
);
2443 err
= do_xdp_generic(xdp_prog
, skb
);
2444 if (err
!= XDP_PASS
)
2448 if (!rcu_dereference(tun
->steering_prog
) && tun
->numqueues
> 1 &&
2450 rxhash
= __skb_get_hash_symmetric(skb
);
2452 netif_receive_skb(skb
);
2454 /* No need for get_cpu_ptr() here since this function is
2455 * always called with bh disabled
2457 stats
= this_cpu_ptr(tun
->pcpu_stats
);
2458 u64_stats_update_begin(&stats
->syncp
);
2459 u64_stats_inc(&stats
->rx_packets
);
2460 u64_stats_add(&stats
->rx_bytes
, datasize
);
2461 u64_stats_update_end(&stats
->syncp
);
2464 tun_flow_update(tun
, rxhash
, tfile
);
2470 static int tun_sendmsg(struct socket
*sock
, struct msghdr
*m
, size_t total_len
)
2473 struct tun_file
*tfile
= container_of(sock
, struct tun_file
, socket
);
2474 struct tun_struct
*tun
= tun_get(tfile
);
2475 struct tun_msg_ctl
*ctl
= m
->msg_control
;
2476 struct xdp_buff
*xdp
;
2481 if (ctl
&& (ctl
->type
== TUN_MSG_PTR
)) {
2482 struct tun_page tpage
;
2486 memset(&tpage
, 0, sizeof(tpage
));
2491 for (i
= 0; i
< n
; i
++) {
2492 xdp
= &((struct xdp_buff
*)ctl
->ptr
)[i
];
2493 tun_xdp_one(tun
, tfile
, xdp
, &flush
, &tpage
);
2502 tun_put_page(&tpage
);
2508 ret
= tun_get_user(tun
, tfile
, ctl
? ctl
->ptr
: NULL
, &m
->msg_iter
,
2509 m
->msg_flags
& MSG_DONTWAIT
,
2510 m
->msg_flags
& MSG_MORE
);
2516 static int tun_recvmsg(struct socket
*sock
, struct msghdr
*m
, size_t total_len
,
2519 struct tun_file
*tfile
= container_of(sock
, struct tun_file
, socket
);
2520 struct tun_struct
*tun
= tun_get(tfile
);
2521 void *ptr
= m
->msg_control
;
2529 if (flags
& ~(MSG_DONTWAIT
|MSG_TRUNC
|MSG_ERRQUEUE
)) {
2533 if (flags
& MSG_ERRQUEUE
) {
2534 ret
= sock_recv_errqueue(sock
->sk
, m
, total_len
,
2535 SOL_PACKET
, TUN_TX_TIMESTAMP
);
2538 ret
= tun_do_read(tun
, tfile
, &m
->msg_iter
, flags
& MSG_DONTWAIT
, ptr
);
2539 if (ret
> (ssize_t
)total_len
) {
2540 m
->msg_flags
|= MSG_TRUNC
;
2541 ret
= flags
& MSG_TRUNC
? ret
: total_len
;
2554 static int tun_ptr_peek_len(void *ptr
)
2557 if (tun_is_xdp_frame(ptr
)) {
2558 struct xdp_frame
*xdpf
= tun_ptr_to_xdp(ptr
);
2562 return __skb_array_len_with_tag(ptr
);
2568 static int tun_peek_len(struct socket
*sock
)
2570 struct tun_file
*tfile
= container_of(sock
, struct tun_file
, socket
);
2571 struct tun_struct
*tun
;
2574 tun
= tun_get(tfile
);
2578 ret
= PTR_RING_PEEK_CALL(&tfile
->tx_ring
, tun_ptr_peek_len
);
2584 /* Ops structure to mimic raw sockets with tun */
2585 static const struct proto_ops tun_socket_ops
= {
2586 .peek_len
= tun_peek_len
,
2587 .sendmsg
= tun_sendmsg
,
2588 .recvmsg
= tun_recvmsg
,
2591 static struct proto tun_proto
= {
2593 .owner
= THIS_MODULE
,
2594 .obj_size
= sizeof(struct tun_file
),
2597 static int tun_flags(struct tun_struct
*tun
)
2599 return tun
->flags
& (TUN_FEATURES
| IFF_PERSIST
| IFF_TUN
| IFF_TAP
);
2602 static ssize_t
tun_show_flags(struct device
*dev
, struct device_attribute
*attr
,
2605 struct tun_struct
*tun
= netdev_priv(to_net_dev(dev
));
2606 return sprintf(buf
, "0x%x\n", tun_flags(tun
));
2609 static ssize_t
tun_show_owner(struct device
*dev
, struct device_attribute
*attr
,
2612 struct tun_struct
*tun
= netdev_priv(to_net_dev(dev
));
2613 return uid_valid(tun
->owner
)?
2614 sprintf(buf
, "%u\n",
2615 from_kuid_munged(current_user_ns(), tun
->owner
)):
2616 sprintf(buf
, "-1\n");
2619 static ssize_t
tun_show_group(struct device
*dev
, struct device_attribute
*attr
,
2622 struct tun_struct
*tun
= netdev_priv(to_net_dev(dev
));
2623 return gid_valid(tun
->group
) ?
2624 sprintf(buf
, "%u\n",
2625 from_kgid_munged(current_user_ns(), tun
->group
)):
2626 sprintf(buf
, "-1\n");
2629 static DEVICE_ATTR(tun_flags
, 0444, tun_show_flags
, NULL
);
2630 static DEVICE_ATTR(owner
, 0444, tun_show_owner
, NULL
);
2631 static DEVICE_ATTR(group
, 0444, tun_show_group
, NULL
);
2633 static struct attribute
*tun_dev_attrs
[] = {
2634 &dev_attr_tun_flags
.attr
,
2635 &dev_attr_owner
.attr
,
2636 &dev_attr_group
.attr
,
2640 static const struct attribute_group tun_attr_group
= {
2641 .attrs
= tun_dev_attrs
2644 static int tun_set_iff(struct net
*net
, struct file
*file
, struct ifreq
*ifr
)
2646 struct tun_struct
*tun
;
2647 struct tun_file
*tfile
= file
->private_data
;
2648 struct net_device
*dev
;
2651 if (tfile
->detached
)
2654 if ((ifr
->ifr_flags
& IFF_NAPI_FRAGS
)) {
2655 if (!capable(CAP_NET_ADMIN
))
2658 if (!(ifr
->ifr_flags
& IFF_NAPI
) ||
2659 (ifr
->ifr_flags
& TUN_TYPE_MASK
) != IFF_TAP
)
2663 dev
= __dev_get_by_name(net
, ifr
->ifr_name
);
2665 if (ifr
->ifr_flags
& IFF_TUN_EXCL
)
2667 if ((ifr
->ifr_flags
& IFF_TUN
) && dev
->netdev_ops
== &tun_netdev_ops
)
2668 tun
= netdev_priv(dev
);
2669 else if ((ifr
->ifr_flags
& IFF_TAP
) && dev
->netdev_ops
== &tap_netdev_ops
)
2670 tun
= netdev_priv(dev
);
2674 if (!!(ifr
->ifr_flags
& IFF_MULTI_QUEUE
) !=
2675 !!(tun
->flags
& IFF_MULTI_QUEUE
))
2678 if (tun_not_capable(tun
))
2680 err
= security_tun_dev_open(tun
->security
);
2684 err
= tun_attach(tun
, file
, ifr
->ifr_flags
& IFF_NOFILTER
,
2685 ifr
->ifr_flags
& IFF_NAPI
,
2686 ifr
->ifr_flags
& IFF_NAPI_FRAGS
, true);
2690 if (tun
->flags
& IFF_MULTI_QUEUE
&&
2691 (tun
->numqueues
+ tun
->numdisabled
> 1)) {
2692 /* One or more queue has already been attached, no need
2693 * to initialize the device again.
2695 netdev_state_change(dev
);
2699 tun
->flags
= (tun
->flags
& ~TUN_FEATURES
) |
2700 (ifr
->ifr_flags
& TUN_FEATURES
);
2702 netdev_state_change(dev
);
2705 unsigned long flags
= 0;
2706 int queues
= ifr
->ifr_flags
& IFF_MULTI_QUEUE
?
2709 if (!ns_capable(net
->user_ns
, CAP_NET_ADMIN
))
2711 err
= security_tun_dev_create();
2716 if (ifr
->ifr_flags
& IFF_TUN
) {
2720 } else if (ifr
->ifr_flags
& IFF_TAP
) {
2728 name
= ifr
->ifr_name
;
2730 dev
= alloc_netdev_mqs(sizeof(struct tun_struct
), name
,
2731 NET_NAME_UNKNOWN
, tun_setup
, queues
,
2737 dev_net_set(dev
, net
);
2738 dev
->rtnl_link_ops
= &tun_link_ops
;
2739 dev
->ifindex
= tfile
->ifindex
;
2740 dev
->sysfs_groups
[0] = &tun_attr_group
;
2742 tun
= netdev_priv(dev
);
2745 tun
->txflt
.count
= 0;
2746 tun
->vnet_hdr_sz
= sizeof(struct virtio_net_hdr
);
2748 tun
->align
= NET_SKB_PAD
;
2749 tun
->filter_attached
= false;
2750 tun
->sndbuf
= tfile
->socket
.sk
->sk_sndbuf
;
2751 tun
->rx_batched
= 0;
2752 RCU_INIT_POINTER(tun
->steering_prog
, NULL
);
2754 tun
->pcpu_stats
= netdev_alloc_pcpu_stats(struct tun_pcpu_stats
);
2755 if (!tun
->pcpu_stats
) {
2760 spin_lock_init(&tun
->lock
);
2762 err
= security_tun_dev_alloc_security(&tun
->security
);
2769 dev
->hw_features
= NETIF_F_SG
| NETIF_F_FRAGLIST
|
2770 TUN_USER_FEATURES
| NETIF_F_HW_VLAN_CTAG_TX
|
2771 NETIF_F_HW_VLAN_STAG_TX
;
2772 dev
->features
= dev
->hw_features
| NETIF_F_LLTX
;
2773 dev
->vlan_features
= dev
->features
&
2774 ~(NETIF_F_HW_VLAN_CTAG_TX
|
2775 NETIF_F_HW_VLAN_STAG_TX
);
2777 tun
->flags
= (tun
->flags
& ~TUN_FEATURES
) |
2778 (ifr
->ifr_flags
& TUN_FEATURES
);
2780 INIT_LIST_HEAD(&tun
->disabled
);
2781 err
= tun_attach(tun
, file
, false, ifr
->ifr_flags
& IFF_NAPI
,
2782 ifr
->ifr_flags
& IFF_NAPI_FRAGS
, false);
2786 err
= register_netdevice(tun
->dev
);
2789 /* free_netdev() won't check refcnt, to aovid race
2790 * with dev_put() we need publish tun after registration.
2792 rcu_assign_pointer(tfile
->tun
, tun
);
2795 netif_carrier_on(tun
->dev
);
2797 /* Make sure persistent devices do not get stuck in
2800 if (netif_running(tun
->dev
))
2801 netif_tx_wake_all_queues(tun
->dev
);
2803 strcpy(ifr
->ifr_name
, tun
->dev
->name
);
2807 tun_detach_all(dev
);
2808 /* We are here because register_netdevice() has failed.
2809 * If register_netdevice() already called tun_free_netdev()
2810 * while dealing with the error, tun->pcpu_stats has been cleared.
2812 if (!tun
->pcpu_stats
)
2816 tun_flow_uninit(tun
);
2817 security_tun_dev_free_security(tun
->security
);
2819 free_percpu(tun
->pcpu_stats
);
2825 static void tun_get_iff(struct tun_struct
*tun
, struct ifreq
*ifr
)
2827 strcpy(ifr
->ifr_name
, tun
->dev
->name
);
2829 ifr
->ifr_flags
= tun_flags(tun
);
2833 /* This is like a cut-down ethtool ops, except done via tun fd so no
2834 * privs required. */
2835 static int set_offload(struct tun_struct
*tun
, unsigned long arg
)
2837 netdev_features_t features
= 0;
2839 if (arg
& TUN_F_CSUM
) {
2840 features
|= NETIF_F_HW_CSUM
;
2843 if (arg
& (TUN_F_TSO4
|TUN_F_TSO6
)) {
2844 if (arg
& TUN_F_TSO_ECN
) {
2845 features
|= NETIF_F_TSO_ECN
;
2846 arg
&= ~TUN_F_TSO_ECN
;
2848 if (arg
& TUN_F_TSO4
)
2849 features
|= NETIF_F_TSO
;
2850 if (arg
& TUN_F_TSO6
)
2851 features
|= NETIF_F_TSO6
;
2852 arg
&= ~(TUN_F_TSO4
|TUN_F_TSO6
);
2858 /* This gives the user a way to test for new features in future by
2859 * trying to set them. */
2863 tun
->set_features
= features
;
2864 tun
->dev
->wanted_features
&= ~TUN_USER_FEATURES
;
2865 tun
->dev
->wanted_features
|= features
;
2866 netdev_update_features(tun
->dev
);
2871 static void tun_detach_filter(struct tun_struct
*tun
, int n
)
2874 struct tun_file
*tfile
;
2876 for (i
= 0; i
< n
; i
++) {
2877 tfile
= rtnl_dereference(tun
->tfiles
[i
]);
2878 lock_sock(tfile
->socket
.sk
);
2879 sk_detach_filter(tfile
->socket
.sk
);
2880 release_sock(tfile
->socket
.sk
);
2883 tun
->filter_attached
= false;
2886 static int tun_attach_filter(struct tun_struct
*tun
)
2889 struct tun_file
*tfile
;
2891 for (i
= 0; i
< tun
->numqueues
; i
++) {
2892 tfile
= rtnl_dereference(tun
->tfiles
[i
]);
2893 lock_sock(tfile
->socket
.sk
);
2894 ret
= sk_attach_filter(&tun
->fprog
, tfile
->socket
.sk
);
2895 release_sock(tfile
->socket
.sk
);
2897 tun_detach_filter(tun
, i
);
2902 tun
->filter_attached
= true;
2906 static void tun_set_sndbuf(struct tun_struct
*tun
)
2908 struct tun_file
*tfile
;
2911 for (i
= 0; i
< tun
->numqueues
; i
++) {
2912 tfile
= rtnl_dereference(tun
->tfiles
[i
]);
2913 tfile
->socket
.sk
->sk_sndbuf
= tun
->sndbuf
;
2917 static int tun_set_queue(struct file
*file
, struct ifreq
*ifr
)
2919 struct tun_file
*tfile
= file
->private_data
;
2920 struct tun_struct
*tun
;
2925 if (ifr
->ifr_flags
& IFF_ATTACH_QUEUE
) {
2926 tun
= tfile
->detached
;
2931 ret
= security_tun_dev_attach_queue(tun
->security
);
2934 ret
= tun_attach(tun
, file
, false, tun
->flags
& IFF_NAPI
,
2935 tun
->flags
& IFF_NAPI_FRAGS
, true);
2936 } else if (ifr
->ifr_flags
& IFF_DETACH_QUEUE
) {
2937 tun
= rtnl_dereference(tfile
->tun
);
2938 if (!tun
|| !(tun
->flags
& IFF_MULTI_QUEUE
) || tfile
->detached
)
2941 __tun_detach(tfile
, false);
2946 netdev_state_change(tun
->dev
);
2953 static int tun_set_ebpf(struct tun_struct
*tun
, struct tun_prog __rcu
**prog_p
,
2956 struct bpf_prog
*prog
;
2959 if (copy_from_user(&fd
, data
, sizeof(fd
)))
2965 prog
= bpf_prog_get_type(fd
, BPF_PROG_TYPE_SOCKET_FILTER
);
2967 return PTR_ERR(prog
);
2970 return __tun_set_ebpf(tun
, prog_p
, prog
);
2973 static long __tun_chr_ioctl(struct file
*file
, unsigned int cmd
,
2974 unsigned long arg
, int ifreq_len
)
2976 struct tun_file
*tfile
= file
->private_data
;
2977 struct net
*net
= sock_net(&tfile
->sk
);
2978 struct tun_struct
*tun
;
2979 void __user
* argp
= (void __user
*)arg
;
2980 unsigned int ifindex
, carrier
;
2988 bool do_notify
= false;
2990 if (cmd
== TUNSETIFF
|| cmd
== TUNSETQUEUE
||
2991 (_IOC_TYPE(cmd
) == SOCK_IOC_TYPE
&& cmd
!= SIOCGSKNS
)) {
2992 if (copy_from_user(&ifr
, argp
, ifreq_len
))
2995 memset(&ifr
, 0, sizeof(ifr
));
2997 if (cmd
== TUNGETFEATURES
) {
2998 /* Currently this just means: "what IFF flags are valid?".
2999 * This is needed because we never checked for invalid flags on
3002 return put_user(IFF_TUN
| IFF_TAP
| TUN_FEATURES
,
3003 (unsigned int __user
*)argp
);
3004 } else if (cmd
== TUNSETQUEUE
) {
3005 return tun_set_queue(file
, &ifr
);
3006 } else if (cmd
== SIOCGSKNS
) {
3007 if (!ns_capable(net
->user_ns
, CAP_NET_ADMIN
))
3009 return open_related_ns(&net
->ns
, get_net_ns
);
3015 tun
= tun_get(tfile
);
3016 if (cmd
== TUNSETIFF
) {
3021 ifr
.ifr_name
[IFNAMSIZ
-1] = '\0';
3023 ret
= tun_set_iff(net
, file
, &ifr
);
3028 if (copy_to_user(argp
, &ifr
, ifreq_len
))
3032 if (cmd
== TUNSETIFINDEX
) {
3038 if (copy_from_user(&ifindex
, argp
, sizeof(ifindex
)))
3042 tfile
->ifindex
= ifindex
;
3050 netif_info(tun
, drv
, tun
->dev
, "tun_chr_ioctl cmd %u\n", cmd
);
3052 net
= dev_net(tun
->dev
);
3056 tun_get_iff(tun
, &ifr
);
3058 if (tfile
->detached
)
3059 ifr
.ifr_flags
|= IFF_DETACH_QUEUE
;
3060 if (!tfile
->socket
.sk
->sk_filter
)
3061 ifr
.ifr_flags
|= IFF_NOFILTER
;
3063 if (copy_to_user(argp
, &ifr
, ifreq_len
))
3068 /* Disable/Enable checksum */
3070 /* [unimplemented] */
3071 netif_info(tun
, drv
, tun
->dev
, "ignored: set checksum %s\n",
3072 arg
? "disabled" : "enabled");
3076 /* Disable/Enable persist mode. Keep an extra reference to the
3077 * module to prevent the module being unprobed.
3079 if (arg
&& !(tun
->flags
& IFF_PERSIST
)) {
3080 tun
->flags
|= IFF_PERSIST
;
3081 __module_get(THIS_MODULE
);
3084 if (!arg
&& (tun
->flags
& IFF_PERSIST
)) {
3085 tun
->flags
&= ~IFF_PERSIST
;
3086 module_put(THIS_MODULE
);
3090 netif_info(tun
, drv
, tun
->dev
, "persist %s\n",
3091 arg
? "enabled" : "disabled");
3095 /* Set owner of the device */
3096 owner
= make_kuid(current_user_ns(), arg
);
3097 if (!uid_valid(owner
)) {
3103 netif_info(tun
, drv
, tun
->dev
, "owner set to %u\n",
3104 from_kuid(&init_user_ns
, tun
->owner
));
3108 /* Set group of the device */
3109 group
= make_kgid(current_user_ns(), arg
);
3110 if (!gid_valid(group
)) {
3116 netif_info(tun
, drv
, tun
->dev
, "group set to %u\n",
3117 from_kgid(&init_user_ns
, tun
->group
));
3121 /* Only allow setting the type when the interface is down */
3122 if (tun
->dev
->flags
& IFF_UP
) {
3123 netif_info(tun
, drv
, tun
->dev
,
3124 "Linktype set failed because interface is up\n");
3127 tun
->dev
->type
= (int) arg
;
3128 netif_info(tun
, drv
, tun
->dev
, "linktype set to %d\n",
3135 tun
->msg_enable
= (u32
)arg
;
3139 ret
= set_offload(tun
, arg
);
3142 case TUNSETTXFILTER
:
3143 /* Can be set only for TAPs */
3145 if ((tun
->flags
& TUN_TYPE_MASK
) != IFF_TAP
)
3147 ret
= update_filter(&tun
->txflt
, (void __user
*)arg
);
3151 /* Get hw address */
3152 memcpy(ifr
.ifr_hwaddr
.sa_data
, tun
->dev
->dev_addr
, ETH_ALEN
);
3153 ifr
.ifr_hwaddr
.sa_family
= tun
->dev
->type
;
3154 if (copy_to_user(argp
, &ifr
, ifreq_len
))
3159 /* Set hw address */
3160 ret
= dev_set_mac_address(tun
->dev
, &ifr
.ifr_hwaddr
, NULL
);
3164 sndbuf
= tfile
->socket
.sk
->sk_sndbuf
;
3165 if (copy_to_user(argp
, &sndbuf
, sizeof(sndbuf
)))
3170 if (copy_from_user(&sndbuf
, argp
, sizeof(sndbuf
))) {
3179 tun
->sndbuf
= sndbuf
;
3180 tun_set_sndbuf(tun
);
3183 case TUNGETVNETHDRSZ
:
3184 vnet_hdr_sz
= tun
->vnet_hdr_sz
;
3185 if (copy_to_user(argp
, &vnet_hdr_sz
, sizeof(vnet_hdr_sz
)))
3189 case TUNSETVNETHDRSZ
:
3190 if (copy_from_user(&vnet_hdr_sz
, argp
, sizeof(vnet_hdr_sz
))) {
3194 if (vnet_hdr_sz
< (int)sizeof(struct virtio_net_hdr
)) {
3199 tun
->vnet_hdr_sz
= vnet_hdr_sz
;
3203 le
= !!(tun
->flags
& TUN_VNET_LE
);
3204 if (put_user(le
, (int __user
*)argp
))
3209 if (get_user(le
, (int __user
*)argp
)) {
3214 tun
->flags
|= TUN_VNET_LE
;
3216 tun
->flags
&= ~TUN_VNET_LE
;
3220 ret
= tun_get_vnet_be(tun
, argp
);
3224 ret
= tun_set_vnet_be(tun
, argp
);
3227 case TUNATTACHFILTER
:
3228 /* Can be set only for TAPs */
3230 if ((tun
->flags
& TUN_TYPE_MASK
) != IFF_TAP
)
3233 if (copy_from_user(&tun
->fprog
, argp
, sizeof(tun
->fprog
)))
3236 ret
= tun_attach_filter(tun
);
3239 case TUNDETACHFILTER
:
3240 /* Can be set only for TAPs */
3242 if ((tun
->flags
& TUN_TYPE_MASK
) != IFF_TAP
)
3245 tun_detach_filter(tun
, tun
->numqueues
);
3250 if ((tun
->flags
& TUN_TYPE_MASK
) != IFF_TAP
)
3253 if (copy_to_user(argp
, &tun
->fprog
, sizeof(tun
->fprog
)))
3258 case TUNSETSTEERINGEBPF
:
3259 ret
= tun_set_ebpf(tun
, &tun
->steering_prog
, argp
);
3262 case TUNSETFILTEREBPF
:
3263 ret
= tun_set_ebpf(tun
, &tun
->filter_prog
, argp
);
3268 if (copy_from_user(&carrier
, argp
, sizeof(carrier
)))
3271 ret
= tun_net_change_carrier(tun
->dev
, (bool)carrier
);
3274 case TUNGETDEVNETNS
:
3276 if (!ns_capable(net
->user_ns
, CAP_NET_ADMIN
))
3278 ret
= open_related_ns(&net
->ns
, get_net_ns
);
3287 netdev_state_change(tun
->dev
);
3296 static long tun_chr_ioctl(struct file
*file
,
3297 unsigned int cmd
, unsigned long arg
)
3299 return __tun_chr_ioctl(file
, cmd
, arg
, sizeof (struct ifreq
));
3302 #ifdef CONFIG_COMPAT
3303 static long tun_chr_compat_ioctl(struct file
*file
,
3304 unsigned int cmd
, unsigned long arg
)
3309 case TUNSETTXFILTER
:
3314 arg
= (unsigned long)compat_ptr(arg
);
3317 arg
= (compat_ulong_t
)arg
;
3322 * compat_ifreq is shorter than ifreq, so we must not access beyond
3323 * the end of that structure. All fields that are used in this
3324 * driver are compatible though, we don't need to convert the
3327 return __tun_chr_ioctl(file
, cmd
, arg
, sizeof(struct compat_ifreq
));
3329 #endif /* CONFIG_COMPAT */
3331 static int tun_chr_fasync(int fd
, struct file
*file
, int on
)
3333 struct tun_file
*tfile
= file
->private_data
;
3336 if ((ret
= fasync_helper(fd
, file
, on
, &tfile
->fasync
)) < 0)
3340 __f_setown(file
, task_pid(current
), PIDTYPE_TGID
, 0);
3341 tfile
->flags
|= TUN_FASYNC
;
3343 tfile
->flags
&= ~TUN_FASYNC
;
3349 static int tun_chr_open(struct inode
*inode
, struct file
* file
)
3351 struct net
*net
= current
->nsproxy
->net_ns
;
3352 struct tun_file
*tfile
;
3354 tfile
= (struct tun_file
*)sk_alloc(net
, AF_UNSPEC
, GFP_KERNEL
,
3358 if (ptr_ring_init(&tfile
->tx_ring
, 0, GFP_KERNEL
)) {
3359 sk_free(&tfile
->sk
);
3363 mutex_init(&tfile
->napi_mutex
);
3364 RCU_INIT_POINTER(tfile
->tun
, NULL
);
3368 init_waitqueue_head(&tfile
->socket
.wq
.wait
);
3370 tfile
->socket
.file
= file
;
3371 tfile
->socket
.ops
= &tun_socket_ops
;
3373 sock_init_data(&tfile
->socket
, &tfile
->sk
);
3375 tfile
->sk
.sk_write_space
= tun_sock_write_space
;
3376 tfile
->sk
.sk_sndbuf
= INT_MAX
;
3378 file
->private_data
= tfile
;
3379 INIT_LIST_HEAD(&tfile
->next
);
3381 sock_set_flag(&tfile
->sk
, SOCK_ZEROCOPY
);
3386 static int tun_chr_close(struct inode
*inode
, struct file
*file
)
3388 struct tun_file
*tfile
= file
->private_data
;
3390 tun_detach(tfile
, true);
3395 #ifdef CONFIG_PROC_FS
3396 static void tun_chr_show_fdinfo(struct seq_file
*m
, struct file
*file
)
3398 struct tun_file
*tfile
= file
->private_data
;
3399 struct tun_struct
*tun
;
3402 memset(&ifr
, 0, sizeof(ifr
));
3405 tun
= tun_get(tfile
);
3407 tun_get_iff(tun
, &ifr
);
3413 seq_printf(m
, "iff:\t%s\n", ifr
.ifr_name
);
3417 static const struct file_operations tun_fops
= {
3418 .owner
= THIS_MODULE
,
3419 .llseek
= no_llseek
,
3420 .read_iter
= tun_chr_read_iter
,
3421 .write_iter
= tun_chr_write_iter
,
3422 .poll
= tun_chr_poll
,
3423 .unlocked_ioctl
= tun_chr_ioctl
,
3424 #ifdef CONFIG_COMPAT
3425 .compat_ioctl
= tun_chr_compat_ioctl
,
3427 .open
= tun_chr_open
,
3428 .release
= tun_chr_close
,
3429 .fasync
= tun_chr_fasync
,
3430 #ifdef CONFIG_PROC_FS
3431 .show_fdinfo
= tun_chr_show_fdinfo
,
3435 static struct miscdevice tun_miscdev
= {
3438 .nodename
= "net/tun",
3442 /* ethtool interface */
3444 static void tun_default_link_ksettings(struct net_device
*dev
,
3445 struct ethtool_link_ksettings
*cmd
)
3447 ethtool_link_ksettings_zero_link_mode(cmd
, supported
);
3448 ethtool_link_ksettings_zero_link_mode(cmd
, advertising
);
3449 cmd
->base
.speed
= SPEED_10
;
3450 cmd
->base
.duplex
= DUPLEX_FULL
;
3451 cmd
->base
.port
= PORT_TP
;
3452 cmd
->base
.phy_address
= 0;
3453 cmd
->base
.autoneg
= AUTONEG_DISABLE
;
3456 static int tun_get_link_ksettings(struct net_device
*dev
,
3457 struct ethtool_link_ksettings
*cmd
)
3459 struct tun_struct
*tun
= netdev_priv(dev
);
3461 memcpy(cmd
, &tun
->link_ksettings
, sizeof(*cmd
));
3465 static int tun_set_link_ksettings(struct net_device
*dev
,
3466 const struct ethtool_link_ksettings
*cmd
)
3468 struct tun_struct
*tun
= netdev_priv(dev
);
3470 memcpy(&tun
->link_ksettings
, cmd
, sizeof(*cmd
));
3474 static void tun_get_drvinfo(struct net_device
*dev
, struct ethtool_drvinfo
*info
)
3476 struct tun_struct
*tun
= netdev_priv(dev
);
3478 strlcpy(info
->driver
, DRV_NAME
, sizeof(info
->driver
));
3479 strlcpy(info
->version
, DRV_VERSION
, sizeof(info
->version
));
3481 switch (tun
->flags
& TUN_TYPE_MASK
) {
3483 strlcpy(info
->bus_info
, "tun", sizeof(info
->bus_info
));
3486 strlcpy(info
->bus_info
, "tap", sizeof(info
->bus_info
));
3491 static u32
tun_get_msglevel(struct net_device
*dev
)
3493 struct tun_struct
*tun
= netdev_priv(dev
);
3495 return tun
->msg_enable
;
3498 static void tun_set_msglevel(struct net_device
*dev
, u32 value
)
3500 struct tun_struct
*tun
= netdev_priv(dev
);
3502 tun
->msg_enable
= value
;
3505 static int tun_get_coalesce(struct net_device
*dev
,
3506 struct ethtool_coalesce
*ec
)
3508 struct tun_struct
*tun
= netdev_priv(dev
);
3510 ec
->rx_max_coalesced_frames
= tun
->rx_batched
;
3515 static int tun_set_coalesce(struct net_device
*dev
,
3516 struct ethtool_coalesce
*ec
)
3518 struct tun_struct
*tun
= netdev_priv(dev
);
3520 if (ec
->rx_max_coalesced_frames
> NAPI_POLL_WEIGHT
)
3521 tun
->rx_batched
= NAPI_POLL_WEIGHT
;
3523 tun
->rx_batched
= ec
->rx_max_coalesced_frames
;
3528 static const struct ethtool_ops tun_ethtool_ops
= {
3529 .supported_coalesce_params
= ETHTOOL_COALESCE_RX_MAX_FRAMES
,
3530 .get_drvinfo
= tun_get_drvinfo
,
3531 .get_msglevel
= tun_get_msglevel
,
3532 .set_msglevel
= tun_set_msglevel
,
3533 .get_link
= ethtool_op_get_link
,
3534 .get_ts_info
= ethtool_op_get_ts_info
,
3535 .get_coalesce
= tun_get_coalesce
,
3536 .set_coalesce
= tun_set_coalesce
,
3537 .get_link_ksettings
= tun_get_link_ksettings
,
3538 .set_link_ksettings
= tun_set_link_ksettings
,
3541 static int tun_queue_resize(struct tun_struct
*tun
)
3543 struct net_device
*dev
= tun
->dev
;
3544 struct tun_file
*tfile
;
3545 struct ptr_ring
**rings
;
3546 int n
= tun
->numqueues
+ tun
->numdisabled
;
3549 rings
= kmalloc_array(n
, sizeof(*rings
), GFP_KERNEL
);
3553 for (i
= 0; i
< tun
->numqueues
; i
++) {
3554 tfile
= rtnl_dereference(tun
->tfiles
[i
]);
3555 rings
[i
] = &tfile
->tx_ring
;
3557 list_for_each_entry(tfile
, &tun
->disabled
, next
)
3558 rings
[i
++] = &tfile
->tx_ring
;
3560 ret
= ptr_ring_resize_multiple(rings
, n
,
3561 dev
->tx_queue_len
, GFP_KERNEL
,
3568 static int tun_device_event(struct notifier_block
*unused
,
3569 unsigned long event
, void *ptr
)
3571 struct net_device
*dev
= netdev_notifier_info_to_dev(ptr
);
3572 struct tun_struct
*tun
= netdev_priv(dev
);
3575 if (dev
->rtnl_link_ops
!= &tun_link_ops
)
3579 case NETDEV_CHANGE_TX_QUEUE_LEN
:
3580 if (tun_queue_resize(tun
))
3584 for (i
= 0; i
< tun
->numqueues
; i
++) {
3585 struct tun_file
*tfile
;
3587 tfile
= rtnl_dereference(tun
->tfiles
[i
]);
3588 tfile
->socket
.sk
->sk_write_space(tfile
->socket
.sk
);
3598 static struct notifier_block tun_notifier_block __read_mostly
= {
3599 .notifier_call
= tun_device_event
,
3602 static int __init
tun_init(void)
3606 pr_info("%s, %s\n", DRV_DESCRIPTION
, DRV_VERSION
);
3608 ret
= rtnl_link_register(&tun_link_ops
);
3610 pr_err("Can't register link_ops\n");
3614 ret
= misc_register(&tun_miscdev
);
3616 pr_err("Can't register misc device %d\n", TUN_MINOR
);
3620 ret
= register_netdevice_notifier(&tun_notifier_block
);
3622 pr_err("Can't register netdevice notifier\n");
3629 misc_deregister(&tun_miscdev
);
3631 rtnl_link_unregister(&tun_link_ops
);
3636 static void tun_cleanup(void)
3638 misc_deregister(&tun_miscdev
);
3639 rtnl_link_unregister(&tun_link_ops
);
3640 unregister_netdevice_notifier(&tun_notifier_block
);
3643 /* Get an underlying socket object from tun file. Returns error unless file is
3644 * attached to a device. The returned object works like a packet socket, it
3645 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
3646 * holding a reference to the file for as long as the socket is in use. */
3647 struct socket
*tun_get_socket(struct file
*file
)
3649 struct tun_file
*tfile
;
3650 if (file
->f_op
!= &tun_fops
)
3651 return ERR_PTR(-EINVAL
);
3652 tfile
= file
->private_data
;
3654 return ERR_PTR(-EBADFD
);
3655 return &tfile
->socket
;
3657 EXPORT_SYMBOL_GPL(tun_get_socket
);
3659 struct ptr_ring
*tun_get_tx_ring(struct file
*file
)
3661 struct tun_file
*tfile
;
3663 if (file
->f_op
!= &tun_fops
)
3664 return ERR_PTR(-EINVAL
);
3665 tfile
= file
->private_data
;
3667 return ERR_PTR(-EBADFD
);
3668 return &tfile
->tx_ring
;
3670 EXPORT_SYMBOL_GPL(tun_get_tx_ring
);
3672 module_init(tun_init
);
3673 module_exit(tun_cleanup
);
3674 MODULE_DESCRIPTION(DRV_DESCRIPTION
);
3675 MODULE_AUTHOR(DRV_COPYRIGHT
);
3676 MODULE_LICENSE("GPL");
3677 MODULE_ALIAS_MISCDEV(TUN_MINOR
);
3678 MODULE_ALIAS("devname:net/tun");