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 <linux/seq_file.h>
66 #include <linux/uio.h>
67 #include <linux/skb_array.h>
68 #include <linux/bpf.h>
69 #include <linux/bpf_trace.h>
70 #include <linux/mutex.h>
72 #include <linux/uaccess.h>
73 #include <linux/proc_fs.h>
75 static void tun_default_link_ksettings(struct net_device *dev,
76 struct ethtool_link_ksettings *cmd);
78 /* Uncomment to enable debugging */
79 /* #define TUN_DEBUG 1 */
84 #define tun_debug(level, tun, fmt, args...) \
87 netdev_printk(level, tun->dev, fmt, ##args); \
89 #define DBG1(level, fmt, args...) \
92 printk(level fmt, ##args); \
95 #define tun_debug(level, tun, fmt, args...) \
98 netdev_printk(level, tun->dev, fmt, ##args); \
100 #define DBG1(level, fmt, args...) \
103 printk(level fmt, ##args); \
107 #define TUN_RX_PAD (NET_IP_ALIGN + NET_SKB_PAD)
109 /* TUN device flags */
111 /* IFF_ATTACH_QUEUE is never stored in device flags,
112 * overload it to mean fasync when stored there.
114 #define TUN_FASYNC IFF_ATTACH_QUEUE
115 /* High bits in flags field are unused. */
116 #define TUN_VNET_LE 0x80000000
117 #define TUN_VNET_BE 0x40000000
119 #define TUN_FEATURES (IFF_NO_PI | IFF_ONE_QUEUE | IFF_VNET_HDR | \
120 IFF_MULTI_QUEUE | IFF_NAPI | IFF_NAPI_FRAGS)
122 #define GOODCOPY_LEN 128
124 #define FLT_EXACT_COUNT 8
126 unsigned int count; /* Number of addrs. Zero means disabled */
127 u32 mask[2]; /* Mask of the hashed addrs */
128 unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN];
131 /* MAX_TAP_QUEUES 256 is chosen to allow rx/tx queues to be equal
132 * to max number of VCPUs in guest. */
133 #define MAX_TAP_QUEUES 256
134 #define MAX_TAP_FLOWS 4096
136 #define TUN_FLOW_EXPIRE (3 * HZ)
138 struct tun_pcpu_stats {
143 struct u64_stats_sync syncp;
149 /* A tun_file connects an open character device to a tuntap netdevice. It
150 * also contains all socket related structures (except sock_fprog and tap_filter)
151 * to serve as one transmit queue for tuntap device. The sock_fprog and
152 * tap_filter were kept in tun_struct since they were used for filtering for the
153 * netdevice not for a specific queue (at least I didn't see the requirement for
157 * The tun_file and tun_struct are loosely coupled, the pointer from one to the
158 * other can only be read while rcu_read_lock or rtnl_lock is held.
162 struct socket socket;
163 struct tun_struct __rcu *tun;
164 struct fasync_struct *fasync;
165 /* only used for fasnyc */
169 unsigned int ifindex;
171 struct napi_struct napi;
173 bool napi_frags_enabled;
174 struct mutex napi_mutex; /* Protects access to the above napi */
175 struct list_head next;
176 struct tun_struct *detached;
177 struct ptr_ring tx_ring;
178 struct xdp_rxq_info xdp_rxq;
186 struct tun_flow_entry {
187 struct hlist_node hash_link;
189 struct tun_struct *tun;
194 unsigned long updated ____cacheline_aligned_in_smp;
197 #define TUN_NUM_FLOW_ENTRIES 1024
198 #define TUN_MASK_FLOW_ENTRIES (TUN_NUM_FLOW_ENTRIES - 1)
202 struct bpf_prog *prog;
205 /* Since the socket were moved to tun_file, to preserve the behavior of persist
206 * device, socket filter, sndbuf and vnet header size were restore when the
207 * file were attached to a persist device.
210 struct tun_file __rcu *tfiles[MAX_TAP_QUEUES];
211 unsigned int numqueues;
216 struct net_device *dev;
217 netdev_features_t set_features;
218 #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \
224 struct tap_filter txflt;
225 struct sock_fprog fprog;
226 /* protected by rtnl lock */
227 bool filter_attached;
232 struct hlist_head flows[TUN_NUM_FLOW_ENTRIES];
233 struct timer_list flow_gc_timer;
234 unsigned long ageing_time;
235 unsigned int numdisabled;
236 struct list_head disabled;
240 struct tun_pcpu_stats __percpu *pcpu_stats;
241 struct bpf_prog __rcu *xdp_prog;
242 struct tun_prog __rcu *steering_prog;
243 struct tun_prog __rcu *filter_prog;
244 struct ethtool_link_ksettings link_ksettings;
252 bool tun_is_xdp_frame(void *ptr)
254 return (unsigned long)ptr & TUN_XDP_FLAG;
256 EXPORT_SYMBOL(tun_is_xdp_frame);
258 void *tun_xdp_to_ptr(void *ptr)
260 return (void *)((unsigned long)ptr | TUN_XDP_FLAG);
262 EXPORT_SYMBOL(tun_xdp_to_ptr);
264 void *tun_ptr_to_xdp(void *ptr)
266 return (void *)((unsigned long)ptr & ~TUN_XDP_FLAG);
268 EXPORT_SYMBOL(tun_ptr_to_xdp);
270 static int tun_napi_receive(struct napi_struct *napi, int budget)
272 struct tun_file *tfile = container_of(napi, struct tun_file, napi);
273 struct sk_buff_head *queue = &tfile->sk.sk_write_queue;
274 struct sk_buff_head process_queue;
278 __skb_queue_head_init(&process_queue);
280 spin_lock(&queue->lock);
281 skb_queue_splice_tail_init(queue, &process_queue);
282 spin_unlock(&queue->lock);
284 while (received < budget && (skb = __skb_dequeue(&process_queue))) {
285 napi_gro_receive(napi, skb);
289 if (!skb_queue_empty(&process_queue)) {
290 spin_lock(&queue->lock);
291 skb_queue_splice(&process_queue, queue);
292 spin_unlock(&queue->lock);
298 static int tun_napi_poll(struct napi_struct *napi, int budget)
300 unsigned int received;
302 received = tun_napi_receive(napi, budget);
304 if (received < budget)
305 napi_complete_done(napi, received);
310 static void tun_napi_init(struct tun_struct *tun, struct tun_file *tfile,
311 bool napi_en, bool napi_frags)
313 tfile->napi_enabled = napi_en;
314 tfile->napi_frags_enabled = napi_en && napi_frags;
316 netif_napi_add(tun->dev, &tfile->napi, tun_napi_poll,
318 napi_enable(&tfile->napi);
322 static void tun_napi_disable(struct tun_file *tfile)
324 if (tfile->napi_enabled)
325 napi_disable(&tfile->napi);
328 static void tun_napi_del(struct tun_file *tfile)
330 if (tfile->napi_enabled)
331 netif_napi_del(&tfile->napi);
334 static bool tun_napi_frags_enabled(const struct tun_file *tfile)
336 return tfile->napi_frags_enabled;
339 #ifdef CONFIG_TUN_VNET_CROSS_LE
340 static inline bool tun_legacy_is_little_endian(struct tun_struct *tun)
342 return tun->flags & TUN_VNET_BE ? false :
343 virtio_legacy_is_little_endian();
346 static long tun_get_vnet_be(struct tun_struct *tun, int __user *argp)
348 int be = !!(tun->flags & TUN_VNET_BE);
350 if (put_user(be, argp))
356 static long tun_set_vnet_be(struct tun_struct *tun, int __user *argp)
360 if (get_user(be, argp))
364 tun->flags |= TUN_VNET_BE;
366 tun->flags &= ~TUN_VNET_BE;
371 static inline bool tun_legacy_is_little_endian(struct tun_struct *tun)
373 return virtio_legacy_is_little_endian();
376 static long tun_get_vnet_be(struct tun_struct *tun, int __user *argp)
381 static long tun_set_vnet_be(struct tun_struct *tun, int __user *argp)
385 #endif /* CONFIG_TUN_VNET_CROSS_LE */
387 static inline bool tun_is_little_endian(struct tun_struct *tun)
389 return tun->flags & TUN_VNET_LE ||
390 tun_legacy_is_little_endian(tun);
393 static inline u16 tun16_to_cpu(struct tun_struct *tun, __virtio16 val)
395 return __virtio16_to_cpu(tun_is_little_endian(tun), val);
398 static inline __virtio16 cpu_to_tun16(struct tun_struct *tun, u16 val)
400 return __cpu_to_virtio16(tun_is_little_endian(tun), val);
403 static inline u32 tun_hashfn(u32 rxhash)
405 return rxhash & TUN_MASK_FLOW_ENTRIES;
408 static struct tun_flow_entry *tun_flow_find(struct hlist_head *head, u32 rxhash)
410 struct tun_flow_entry *e;
412 hlist_for_each_entry_rcu(e, head, hash_link) {
413 if (e->rxhash == rxhash)
419 static struct tun_flow_entry *tun_flow_create(struct tun_struct *tun,
420 struct hlist_head *head,
421 u32 rxhash, u16 queue_index)
423 struct tun_flow_entry *e = kmalloc(sizeof(*e), GFP_ATOMIC);
426 tun_debug(KERN_INFO, tun, "create flow: hash %u index %u\n",
427 rxhash, queue_index);
428 e->updated = jiffies;
431 e->queue_index = queue_index;
433 hlist_add_head_rcu(&e->hash_link, head);
439 static void tun_flow_delete(struct tun_struct *tun, struct tun_flow_entry *e)
441 tun_debug(KERN_INFO, tun, "delete flow: hash %u index %u\n",
442 e->rxhash, e->queue_index);
443 hlist_del_rcu(&e->hash_link);
448 static void tun_flow_flush(struct tun_struct *tun)
452 spin_lock_bh(&tun->lock);
453 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
454 struct tun_flow_entry *e;
455 struct hlist_node *n;
457 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link)
458 tun_flow_delete(tun, e);
460 spin_unlock_bh(&tun->lock);
463 static void tun_flow_delete_by_queue(struct tun_struct *tun, u16 queue_index)
467 spin_lock_bh(&tun->lock);
468 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
469 struct tun_flow_entry *e;
470 struct hlist_node *n;
472 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
473 if (e->queue_index == queue_index)
474 tun_flow_delete(tun, e);
477 spin_unlock_bh(&tun->lock);
480 static void tun_flow_cleanup(struct timer_list *t)
482 struct tun_struct *tun = from_timer(tun, t, flow_gc_timer);
483 unsigned long delay = tun->ageing_time;
484 unsigned long next_timer = jiffies + delay;
485 unsigned long count = 0;
488 tun_debug(KERN_INFO, tun, "tun_flow_cleanup\n");
490 spin_lock(&tun->lock);
491 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
492 struct tun_flow_entry *e;
493 struct hlist_node *n;
495 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
496 unsigned long this_timer;
498 this_timer = e->updated + delay;
499 if (time_before_eq(this_timer, jiffies)) {
500 tun_flow_delete(tun, e);
504 if (time_before(this_timer, next_timer))
505 next_timer = this_timer;
510 mod_timer(&tun->flow_gc_timer, round_jiffies_up(next_timer));
511 spin_unlock(&tun->lock);
514 static void tun_flow_update(struct tun_struct *tun, u32 rxhash,
515 struct tun_file *tfile)
517 struct hlist_head *head;
518 struct tun_flow_entry *e;
519 unsigned long delay = tun->ageing_time;
520 u16 queue_index = tfile->queue_index;
522 head = &tun->flows[tun_hashfn(rxhash)];
526 e = tun_flow_find(head, rxhash);
528 /* TODO: keep queueing to old queue until it's empty? */
529 if (e->queue_index != queue_index)
530 e->queue_index = queue_index;
531 if (e->updated != jiffies)
532 e->updated = jiffies;
533 sock_rps_record_flow_hash(e->rps_rxhash);
535 spin_lock_bh(&tun->lock);
536 if (!tun_flow_find(head, rxhash) &&
537 tun->flow_count < MAX_TAP_FLOWS)
538 tun_flow_create(tun, head, rxhash, queue_index);
540 if (!timer_pending(&tun->flow_gc_timer))
541 mod_timer(&tun->flow_gc_timer,
542 round_jiffies_up(jiffies + delay));
543 spin_unlock_bh(&tun->lock);
550 * Save the hash received in the stack receive path and update the
551 * flow_hash table accordingly.
553 static inline void tun_flow_save_rps_rxhash(struct tun_flow_entry *e, u32 hash)
555 if (unlikely(e->rps_rxhash != hash))
556 e->rps_rxhash = hash;
559 /* We try to identify a flow through its rxhash. The reason that
560 * we do not check rxq no. is because some cards(e.g 82599), chooses
561 * the rxq based on the txq where the last packet of the flow comes. As
562 * the userspace application move between processors, we may get a
563 * different rxq no. here.
565 static u16 tun_automq_select_queue(struct tun_struct *tun, struct sk_buff *skb)
567 struct tun_flow_entry *e;
571 numqueues = READ_ONCE(tun->numqueues);
573 txq = __skb_get_hash_symmetric(skb);
574 e = tun_flow_find(&tun->flows[tun_hashfn(txq)], txq);
576 tun_flow_save_rps_rxhash(e, txq);
577 txq = e->queue_index;
579 /* use multiply and shift instead of expensive divide */
580 txq = ((u64)txq * numqueues) >> 32;
586 static u16 tun_ebpf_select_queue(struct tun_struct *tun, struct sk_buff *skb)
588 struct tun_prog *prog;
592 numqueues = READ_ONCE(tun->numqueues);
596 prog = rcu_dereference(tun->steering_prog);
598 ret = bpf_prog_run_clear_cb(prog->prog, skb);
600 return ret % numqueues;
603 static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb,
604 struct net_device *sb_dev)
606 struct tun_struct *tun = netdev_priv(dev);
610 if (rcu_dereference(tun->steering_prog))
611 ret = tun_ebpf_select_queue(tun, skb);
613 ret = tun_automq_select_queue(tun, skb);
619 static inline bool tun_not_capable(struct tun_struct *tun)
621 const struct cred *cred = current_cred();
622 struct net *net = dev_net(tun->dev);
624 return ((uid_valid(tun->owner) && !uid_eq(cred->euid, tun->owner)) ||
625 (gid_valid(tun->group) && !in_egroup_p(tun->group))) &&
626 !ns_capable(net->user_ns, CAP_NET_ADMIN);
629 static void tun_set_real_num_queues(struct tun_struct *tun)
631 netif_set_real_num_tx_queues(tun->dev, tun->numqueues);
632 netif_set_real_num_rx_queues(tun->dev, tun->numqueues);
635 static void tun_disable_queue(struct tun_struct *tun, struct tun_file *tfile)
637 tfile->detached = tun;
638 list_add_tail(&tfile->next, &tun->disabled);
642 static struct tun_struct *tun_enable_queue(struct tun_file *tfile)
644 struct tun_struct *tun = tfile->detached;
646 tfile->detached = NULL;
647 list_del_init(&tfile->next);
652 void tun_ptr_free(void *ptr)
656 if (tun_is_xdp_frame(ptr)) {
657 struct xdp_frame *xdpf = tun_ptr_to_xdp(ptr);
659 xdp_return_frame(xdpf);
661 __skb_array_destroy_skb(ptr);
664 EXPORT_SYMBOL_GPL(tun_ptr_free);
666 static void tun_queue_purge(struct tun_file *tfile)
670 while ((ptr = ptr_ring_consume(&tfile->tx_ring)) != NULL)
673 skb_queue_purge(&tfile->sk.sk_write_queue);
674 skb_queue_purge(&tfile->sk.sk_error_queue);
677 static void __tun_detach(struct tun_file *tfile, bool clean)
679 struct tun_file *ntfile;
680 struct tun_struct *tun;
682 tun = rtnl_dereference(tfile->tun);
685 tun_napi_disable(tfile);
689 if (tun && !tfile->detached) {
690 u16 index = tfile->queue_index;
691 BUG_ON(index >= tun->numqueues);
693 rcu_assign_pointer(tun->tfiles[index],
694 tun->tfiles[tun->numqueues - 1]);
695 ntfile = rtnl_dereference(tun->tfiles[index]);
696 ntfile->queue_index = index;
697 rcu_assign_pointer(tun->tfiles[tun->numqueues - 1],
702 RCU_INIT_POINTER(tfile->tun, NULL);
703 sock_put(&tfile->sk);
705 tun_disable_queue(tun, tfile);
708 tun_flow_delete_by_queue(tun, tun->numqueues + 1);
709 /* Drop read queue */
710 tun_queue_purge(tfile);
711 tun_set_real_num_queues(tun);
712 } else if (tfile->detached && clean) {
713 tun = tun_enable_queue(tfile);
714 sock_put(&tfile->sk);
718 if (tun && tun->numqueues == 0 && tun->numdisabled == 0) {
719 netif_carrier_off(tun->dev);
721 if (!(tun->flags & IFF_PERSIST) &&
722 tun->dev->reg_state == NETREG_REGISTERED)
723 unregister_netdevice(tun->dev);
726 xdp_rxq_info_unreg(&tfile->xdp_rxq);
727 ptr_ring_cleanup(&tfile->tx_ring, tun_ptr_free);
728 sock_put(&tfile->sk);
732 static void tun_detach(struct tun_file *tfile, bool clean)
734 struct tun_struct *tun;
735 struct net_device *dev;
738 tun = rtnl_dereference(tfile->tun);
739 dev = tun ? tun->dev : NULL;
740 __tun_detach(tfile, clean);
742 netdev_state_change(dev);
746 static void tun_detach_all(struct net_device *dev)
748 struct tun_struct *tun = netdev_priv(dev);
749 struct tun_file *tfile, *tmp;
750 int i, n = tun->numqueues;
752 for (i = 0; i < n; i++) {
753 tfile = rtnl_dereference(tun->tfiles[i]);
755 tun_napi_disable(tfile);
756 tfile->socket.sk->sk_shutdown = RCV_SHUTDOWN;
757 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
758 RCU_INIT_POINTER(tfile->tun, NULL);
761 list_for_each_entry(tfile, &tun->disabled, next) {
762 tfile->socket.sk->sk_shutdown = RCV_SHUTDOWN;
763 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
764 RCU_INIT_POINTER(tfile->tun, NULL);
766 BUG_ON(tun->numqueues != 0);
769 for (i = 0; i < n; i++) {
770 tfile = rtnl_dereference(tun->tfiles[i]);
772 /* Drop read queue */
773 tun_queue_purge(tfile);
774 xdp_rxq_info_unreg(&tfile->xdp_rxq);
775 sock_put(&tfile->sk);
777 list_for_each_entry_safe(tfile, tmp, &tun->disabled, next) {
778 tun_enable_queue(tfile);
779 tun_queue_purge(tfile);
780 xdp_rxq_info_unreg(&tfile->xdp_rxq);
781 sock_put(&tfile->sk);
783 BUG_ON(tun->numdisabled != 0);
785 if (tun->flags & IFF_PERSIST)
786 module_put(THIS_MODULE);
789 static int tun_attach(struct tun_struct *tun, struct file *file,
790 bool skip_filter, bool napi, bool napi_frags)
792 struct tun_file *tfile = file->private_data;
793 struct net_device *dev = tun->dev;
796 err = security_tun_dev_attach(tfile->socket.sk, tun->security);
801 if (rtnl_dereference(tfile->tun) && !tfile->detached)
805 if (!(tun->flags & IFF_MULTI_QUEUE) && tun->numqueues == 1)
809 if (!tfile->detached &&
810 tun->numqueues + tun->numdisabled == MAX_TAP_QUEUES)
815 /* Re-attach the filter to persist device */
816 if (!skip_filter && (tun->filter_attached == true)) {
817 lock_sock(tfile->socket.sk);
818 err = sk_attach_filter(&tun->fprog, tfile->socket.sk);
819 release_sock(tfile->socket.sk);
824 if (!tfile->detached &&
825 ptr_ring_resize(&tfile->tx_ring, dev->tx_queue_len,
826 GFP_KERNEL, tun_ptr_free)) {
831 tfile->queue_index = tun->numqueues;
832 tfile->socket.sk->sk_shutdown &= ~RCV_SHUTDOWN;
834 if (tfile->detached) {
835 /* Re-attach detached tfile, updating XDP queue_index */
836 WARN_ON(!xdp_rxq_info_is_reg(&tfile->xdp_rxq));
838 if (tfile->xdp_rxq.queue_index != tfile->queue_index)
839 tfile->xdp_rxq.queue_index = tfile->queue_index;
841 /* Setup XDP RX-queue info, for new tfile getting attached */
842 err = xdp_rxq_info_reg(&tfile->xdp_rxq,
843 tun->dev, tfile->queue_index);
846 err = xdp_rxq_info_reg_mem_model(&tfile->xdp_rxq,
847 MEM_TYPE_PAGE_SHARED, NULL);
849 xdp_rxq_info_unreg(&tfile->xdp_rxq);
855 if (tfile->detached) {
856 tun_enable_queue(tfile);
858 sock_hold(&tfile->sk);
859 tun_napi_init(tun, tfile, napi, napi_frags);
862 if (rtnl_dereference(tun->xdp_prog))
863 sock_set_flag(&tfile->sk, SOCK_XDP);
865 /* device is allowed to go away first, so no need to hold extra
869 /* Publish tfile->tun and tun->tfiles only after we've fully
870 * initialized tfile; otherwise we risk using half-initialized
873 rcu_assign_pointer(tfile->tun, tun);
874 rcu_assign_pointer(tun->tfiles[tun->numqueues], tfile);
876 tun_set_real_num_queues(tun);
881 static struct tun_struct *tun_get(struct tun_file *tfile)
883 struct tun_struct *tun;
886 tun = rcu_dereference(tfile->tun);
894 static void tun_put(struct tun_struct *tun)
900 static void addr_hash_set(u32 *mask, const u8 *addr)
902 int n = ether_crc(ETH_ALEN, addr) >> 26;
903 mask[n >> 5] |= (1 << (n & 31));
906 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
908 int n = ether_crc(ETH_ALEN, addr) >> 26;
909 return mask[n >> 5] & (1 << (n & 31));
912 static int update_filter(struct tap_filter *filter, void __user *arg)
914 struct { u8 u[ETH_ALEN]; } *addr;
915 struct tun_filter uf;
916 int err, alen, n, nexact;
918 if (copy_from_user(&uf, arg, sizeof(uf)))
927 alen = ETH_ALEN * uf.count;
928 addr = memdup_user(arg + sizeof(uf), alen);
930 return PTR_ERR(addr);
932 /* The filter is updated without holding any locks. Which is
933 * perfectly safe. We disable it first and in the worst
934 * case we'll accept a few undesired packets. */
938 /* Use first set of addresses as an exact filter */
939 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
940 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
944 /* Remaining multicast addresses are hashed,
945 * unicast will leave the filter disabled. */
946 memset(filter->mask, 0, sizeof(filter->mask));
947 for (; n < uf.count; n++) {
948 if (!is_multicast_ether_addr(addr[n].u)) {
949 err = 0; /* no filter */
952 addr_hash_set(filter->mask, addr[n].u);
955 /* For ALLMULTI just set the mask to all ones.
956 * This overrides the mask populated above. */
957 if ((uf.flags & TUN_FLT_ALLMULTI))
958 memset(filter->mask, ~0, sizeof(filter->mask));
960 /* Now enable the filter */
962 filter->count = nexact;
964 /* Return the number of exact filters */
971 /* Returns: 0 - drop, !=0 - accept */
972 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
974 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
976 struct ethhdr *eh = (struct ethhdr *) skb->data;
980 for (i = 0; i < filter->count; i++)
981 if (ether_addr_equal(eh->h_dest, filter->addr[i]))
984 /* Inexact match (multicast only) */
985 if (is_multicast_ether_addr(eh->h_dest))
986 return addr_hash_test(filter->mask, eh->h_dest);
992 * Checks whether the packet is accepted or not.
993 * Returns: 0 - drop, !=0 - accept
995 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
1000 return run_filter(filter, skb);
1003 /* Network device part of the driver */
1005 static const struct ethtool_ops tun_ethtool_ops;
1007 /* Net device detach from fd. */
1008 static void tun_net_uninit(struct net_device *dev)
1010 tun_detach_all(dev);
1013 /* Net device open. */
1014 static int tun_net_open(struct net_device *dev)
1016 netif_tx_start_all_queues(dev);
1021 /* Net device close. */
1022 static int tun_net_close(struct net_device *dev)
1024 netif_tx_stop_all_queues(dev);
1028 /* Net device start xmit */
1029 static void tun_automq_xmit(struct tun_struct *tun, struct sk_buff *skb)
1032 if (tun->numqueues == 1 && static_branch_unlikely(&rps_needed)) {
1033 /* Select queue was not called for the skbuff, so we extract the
1034 * RPS hash and save it into the flow_table here.
1036 struct tun_flow_entry *e;
1039 rxhash = __skb_get_hash_symmetric(skb);
1040 e = tun_flow_find(&tun->flows[tun_hashfn(rxhash)], rxhash);
1042 tun_flow_save_rps_rxhash(e, rxhash);
1047 static unsigned int run_ebpf_filter(struct tun_struct *tun,
1048 struct sk_buff *skb,
1051 struct tun_prog *prog = rcu_dereference(tun->filter_prog);
1054 len = bpf_prog_run_clear_cb(prog->prog, skb);
1059 /* Net device start xmit */
1060 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
1062 struct tun_struct *tun = netdev_priv(dev);
1063 int txq = skb->queue_mapping;
1064 struct tun_file *tfile;
1068 tfile = rcu_dereference(tun->tfiles[txq]);
1070 /* Drop packet if interface is not attached */
1074 if (!rcu_dereference(tun->steering_prog))
1075 tun_automq_xmit(tun, skb);
1077 tun_debug(KERN_INFO, tun, "tun_net_xmit %d\n", skb->len);
1081 /* Drop if the filter does not like it.
1082 * This is a noop if the filter is disabled.
1083 * Filter can be enabled only for the TAP devices. */
1084 if (!check_filter(&tun->txflt, skb))
1087 if (tfile->socket.sk->sk_filter &&
1088 sk_filter(tfile->socket.sk, skb))
1091 len = run_ebpf_filter(tun, skb, len);
1092 if (len == 0 || pskb_trim(skb, len))
1095 if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
1098 skb_tx_timestamp(skb);
1100 /* Orphan the skb - required as we might hang on to it
1101 * for indefinite time.
1107 if (ptr_ring_produce(&tfile->tx_ring, skb))
1110 /* Notify and wake up reader process */
1111 if (tfile->flags & TUN_FASYNC)
1112 kill_fasync(&tfile->fasync, SIGIO, POLL_IN);
1113 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
1116 return NETDEV_TX_OK;
1119 this_cpu_inc(tun->pcpu_stats->tx_dropped);
1123 return NET_XMIT_DROP;
1126 static void tun_net_mclist(struct net_device *dev)
1129 * This callback is supposed to deal with mc filter in
1130 * _rx_ path and has nothing to do with the _tx_ path.
1131 * In rx path we always accept everything userspace gives us.
1135 static netdev_features_t tun_net_fix_features(struct net_device *dev,
1136 netdev_features_t features)
1138 struct tun_struct *tun = netdev_priv(dev);
1140 return (features & tun->set_features) | (features & ~TUN_USER_FEATURES);
1143 static void tun_set_headroom(struct net_device *dev, int new_hr)
1145 struct tun_struct *tun = netdev_priv(dev);
1147 if (new_hr < NET_SKB_PAD)
1148 new_hr = NET_SKB_PAD;
1150 tun->align = new_hr;
1154 tun_net_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
1156 u32 rx_dropped = 0, tx_dropped = 0, rx_frame_errors = 0;
1157 struct tun_struct *tun = netdev_priv(dev);
1158 struct tun_pcpu_stats *p;
1161 for_each_possible_cpu(i) {
1162 u64 rxpackets, rxbytes, txpackets, txbytes;
1165 p = per_cpu_ptr(tun->pcpu_stats, i);
1167 start = u64_stats_fetch_begin(&p->syncp);
1168 rxpackets = p->rx_packets;
1169 rxbytes = p->rx_bytes;
1170 txpackets = p->tx_packets;
1171 txbytes = p->tx_bytes;
1172 } while (u64_stats_fetch_retry(&p->syncp, start));
1174 stats->rx_packets += rxpackets;
1175 stats->rx_bytes += rxbytes;
1176 stats->tx_packets += txpackets;
1177 stats->tx_bytes += txbytes;
1180 rx_dropped += p->rx_dropped;
1181 rx_frame_errors += p->rx_frame_errors;
1182 tx_dropped += p->tx_dropped;
1184 stats->rx_dropped = rx_dropped;
1185 stats->rx_frame_errors = rx_frame_errors;
1186 stats->tx_dropped = tx_dropped;
1189 static int tun_xdp_set(struct net_device *dev, struct bpf_prog *prog,
1190 struct netlink_ext_ack *extack)
1192 struct tun_struct *tun = netdev_priv(dev);
1193 struct tun_file *tfile;
1194 struct bpf_prog *old_prog;
1197 old_prog = rtnl_dereference(tun->xdp_prog);
1198 rcu_assign_pointer(tun->xdp_prog, prog);
1200 bpf_prog_put(old_prog);
1202 for (i = 0; i < tun->numqueues; i++) {
1203 tfile = rtnl_dereference(tun->tfiles[i]);
1205 sock_set_flag(&tfile->sk, SOCK_XDP);
1207 sock_reset_flag(&tfile->sk, SOCK_XDP);
1209 list_for_each_entry(tfile, &tun->disabled, next) {
1211 sock_set_flag(&tfile->sk, SOCK_XDP);
1213 sock_reset_flag(&tfile->sk, SOCK_XDP);
1219 static u32 tun_xdp_query(struct net_device *dev)
1221 struct tun_struct *tun = netdev_priv(dev);
1222 const struct bpf_prog *xdp_prog;
1224 xdp_prog = rtnl_dereference(tun->xdp_prog);
1226 return xdp_prog->aux->id;
1231 static int tun_xdp(struct net_device *dev, struct netdev_bpf *xdp)
1233 switch (xdp->command) {
1234 case XDP_SETUP_PROG:
1235 return tun_xdp_set(dev, xdp->prog, xdp->extack);
1236 case XDP_QUERY_PROG:
1237 xdp->prog_id = tun_xdp_query(dev);
1244 static int tun_net_change_carrier(struct net_device *dev, bool new_carrier)
1247 struct tun_struct *tun = netdev_priv(dev);
1249 if (!tun->numqueues)
1252 netif_carrier_on(dev);
1254 netif_carrier_off(dev);
1259 static const struct net_device_ops tun_netdev_ops = {
1260 .ndo_uninit = tun_net_uninit,
1261 .ndo_open = tun_net_open,
1262 .ndo_stop = tun_net_close,
1263 .ndo_start_xmit = tun_net_xmit,
1264 .ndo_fix_features = tun_net_fix_features,
1265 .ndo_select_queue = tun_select_queue,
1266 .ndo_set_rx_headroom = tun_set_headroom,
1267 .ndo_get_stats64 = tun_net_get_stats64,
1268 .ndo_change_carrier = tun_net_change_carrier,
1271 static void __tun_xdp_flush_tfile(struct tun_file *tfile)
1273 /* Notify and wake up reader process */
1274 if (tfile->flags & TUN_FASYNC)
1275 kill_fasync(&tfile->fasync, SIGIO, POLL_IN);
1276 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
1279 static int tun_xdp_xmit(struct net_device *dev, int n,
1280 struct xdp_frame **frames, u32 flags)
1282 struct tun_struct *tun = netdev_priv(dev);
1283 struct tun_file *tfile;
1289 if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
1295 numqueues = READ_ONCE(tun->numqueues);
1298 return -ENXIO; /* Caller will free/return all frames */
1301 tfile = rcu_dereference(tun->tfiles[smp_processor_id() %
1303 if (unlikely(!tfile))
1306 spin_lock(&tfile->tx_ring.producer_lock);
1307 for (i = 0; i < n; i++) {
1308 struct xdp_frame *xdp = frames[i];
1309 /* Encode the XDP flag into lowest bit for consumer to differ
1310 * XDP buffer from sk_buff.
1312 void *frame = tun_xdp_to_ptr(xdp);
1314 if (__ptr_ring_produce(&tfile->tx_ring, frame)) {
1315 this_cpu_inc(tun->pcpu_stats->tx_dropped);
1316 xdp_return_frame_rx_napi(xdp);
1320 spin_unlock(&tfile->tx_ring.producer_lock);
1322 if (flags & XDP_XMIT_FLUSH)
1323 __tun_xdp_flush_tfile(tfile);
1329 static int tun_xdp_tx(struct net_device *dev, struct xdp_buff *xdp)
1331 struct xdp_frame *frame = convert_to_xdp_frame(xdp);
1333 if (unlikely(!frame))
1336 return tun_xdp_xmit(dev, 1, &frame, XDP_XMIT_FLUSH);
1339 static const struct net_device_ops tap_netdev_ops = {
1340 .ndo_uninit = tun_net_uninit,
1341 .ndo_open = tun_net_open,
1342 .ndo_stop = tun_net_close,
1343 .ndo_start_xmit = tun_net_xmit,
1344 .ndo_fix_features = tun_net_fix_features,
1345 .ndo_set_rx_mode = tun_net_mclist,
1346 .ndo_set_mac_address = eth_mac_addr,
1347 .ndo_validate_addr = eth_validate_addr,
1348 .ndo_select_queue = tun_select_queue,
1349 .ndo_features_check = passthru_features_check,
1350 .ndo_set_rx_headroom = tun_set_headroom,
1351 .ndo_get_stats64 = tun_net_get_stats64,
1353 .ndo_xdp_xmit = tun_xdp_xmit,
1354 .ndo_change_carrier = tun_net_change_carrier,
1357 static void tun_flow_init(struct tun_struct *tun)
1361 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++)
1362 INIT_HLIST_HEAD(&tun->flows[i]);
1364 tun->ageing_time = TUN_FLOW_EXPIRE;
1365 timer_setup(&tun->flow_gc_timer, tun_flow_cleanup, 0);
1366 mod_timer(&tun->flow_gc_timer,
1367 round_jiffies_up(jiffies + tun->ageing_time));
1370 static void tun_flow_uninit(struct tun_struct *tun)
1372 del_timer_sync(&tun->flow_gc_timer);
1373 tun_flow_flush(tun);
1377 #define MAX_MTU 65535
1379 /* Initialize net device. */
1380 static void tun_net_init(struct net_device *dev)
1382 struct tun_struct *tun = netdev_priv(dev);
1384 switch (tun->flags & TUN_TYPE_MASK) {
1386 dev->netdev_ops = &tun_netdev_ops;
1388 /* Point-to-Point TUN Device */
1389 dev->hard_header_len = 0;
1393 /* Zero header length */
1394 dev->type = ARPHRD_NONE;
1395 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1399 dev->netdev_ops = &tap_netdev_ops;
1400 /* Ethernet TAP Device */
1402 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1403 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1405 eth_hw_addr_random(dev);
1410 dev->min_mtu = MIN_MTU;
1411 dev->max_mtu = MAX_MTU - dev->hard_header_len;
1414 static bool tun_sock_writeable(struct tun_struct *tun, struct tun_file *tfile)
1416 struct sock *sk = tfile->socket.sk;
1418 return (tun->dev->flags & IFF_UP) && sock_writeable(sk);
1421 /* Character device part */
1424 static __poll_t tun_chr_poll(struct file *file, poll_table *wait)
1426 struct tun_file *tfile = file->private_data;
1427 struct tun_struct *tun = tun_get(tfile);
1434 sk = tfile->socket.sk;
1436 tun_debug(KERN_INFO, tun, "tun_chr_poll\n");
1438 poll_wait(file, sk_sleep(sk), wait);
1440 if (!ptr_ring_empty(&tfile->tx_ring))
1441 mask |= EPOLLIN | EPOLLRDNORM;
1443 /* Make sure SOCKWQ_ASYNC_NOSPACE is set if not writable to
1444 * guarantee EPOLLOUT to be raised by either here or
1445 * tun_sock_write_space(). Then process could get notification
1446 * after it writes to a down device and meets -EIO.
1448 if (tun_sock_writeable(tun, tfile) ||
1449 (!test_and_set_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
1450 tun_sock_writeable(tun, tfile)))
1451 mask |= EPOLLOUT | EPOLLWRNORM;
1453 if (tun->dev->reg_state != NETREG_REGISTERED)
1460 static struct sk_buff *tun_napi_alloc_frags(struct tun_file *tfile,
1462 const struct iov_iter *it)
1464 struct sk_buff *skb;
1469 if (it->nr_segs > MAX_SKB_FRAGS + 1)
1470 return ERR_PTR(-ENOMEM);
1473 skb = napi_get_frags(&tfile->napi);
1476 return ERR_PTR(-ENOMEM);
1478 linear = iov_iter_single_seg_count(it);
1479 err = __skb_grow(skb, linear);
1484 skb->data_len = len - linear;
1485 skb->truesize += skb->data_len;
1487 for (i = 1; i < it->nr_segs; i++) {
1488 size_t fragsz = it->iov[i].iov_len;
1492 if (fragsz == 0 || fragsz > PAGE_SIZE) {
1496 frag = netdev_alloc_frag(fragsz);
1501 page = virt_to_head_page(frag);
1502 skb_fill_page_desc(skb, i - 1, page,
1503 frag - page_address(page), fragsz);
1508 /* frees skb and all frags allocated with napi_alloc_frag() */
1509 napi_free_frags(&tfile->napi);
1510 return ERR_PTR(err);
1513 /* prepad is the amount to reserve at front. len is length after that.
1514 * linear is a hint as to how much to copy (usually headers). */
1515 static struct sk_buff *tun_alloc_skb(struct tun_file *tfile,
1516 size_t prepad, size_t len,
1517 size_t linear, int noblock)
1519 struct sock *sk = tfile->socket.sk;
1520 struct sk_buff *skb;
1523 /* Under a page? Don't bother with paged skb. */
1524 if (prepad + len < PAGE_SIZE || !linear)
1527 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
1530 return ERR_PTR(err);
1532 skb_reserve(skb, prepad);
1533 skb_put(skb, linear);
1534 skb->data_len = len - linear;
1535 skb->len += len - linear;
1540 static void tun_rx_batched(struct tun_struct *tun, struct tun_file *tfile,
1541 struct sk_buff *skb, int more)
1543 struct sk_buff_head *queue = &tfile->sk.sk_write_queue;
1544 struct sk_buff_head process_queue;
1545 u32 rx_batched = tun->rx_batched;
1548 if (!rx_batched || (!more && skb_queue_empty(queue))) {
1550 skb_record_rx_queue(skb, tfile->queue_index);
1551 netif_receive_skb(skb);
1556 spin_lock(&queue->lock);
1557 if (!more || skb_queue_len(queue) == rx_batched) {
1558 __skb_queue_head_init(&process_queue);
1559 skb_queue_splice_tail_init(queue, &process_queue);
1562 __skb_queue_tail(queue, skb);
1564 spin_unlock(&queue->lock);
1567 struct sk_buff *nskb;
1570 while ((nskb = __skb_dequeue(&process_queue))) {
1571 skb_record_rx_queue(nskb, tfile->queue_index);
1572 netif_receive_skb(nskb);
1574 skb_record_rx_queue(skb, tfile->queue_index);
1575 netif_receive_skb(skb);
1580 static bool tun_can_build_skb(struct tun_struct *tun, struct tun_file *tfile,
1581 int len, int noblock, bool zerocopy)
1583 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
1586 if (tfile->socket.sk->sk_sndbuf != INT_MAX)
1595 if (SKB_DATA_ALIGN(len + TUN_RX_PAD) +
1596 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) > PAGE_SIZE)
1602 static struct sk_buff *__tun_build_skb(struct page_frag *alloc_frag, char *buf,
1603 int buflen, int len, int pad)
1605 struct sk_buff *skb = build_skb(buf, buflen);
1608 return ERR_PTR(-ENOMEM);
1610 skb_reserve(skb, pad);
1613 get_page(alloc_frag->page);
1614 alloc_frag->offset += buflen;
1619 static int tun_xdp_act(struct tun_struct *tun, struct bpf_prog *xdp_prog,
1620 struct xdp_buff *xdp, u32 act)
1626 err = xdp_do_redirect(tun->dev, xdp, xdp_prog);
1631 err = tun_xdp_tx(tun->dev, xdp);
1638 bpf_warn_invalid_xdp_action(act);
1641 trace_xdp_exception(tun->dev, xdp_prog, act);
1644 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1651 static struct sk_buff *tun_build_skb(struct tun_struct *tun,
1652 struct tun_file *tfile,
1653 struct iov_iter *from,
1654 struct virtio_net_hdr *hdr,
1655 int len, int *skb_xdp)
1657 struct page_frag *alloc_frag = ¤t->task_frag;
1658 struct bpf_prog *xdp_prog;
1659 int buflen = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
1662 int pad = TUN_RX_PAD;
1666 xdp_prog = rcu_dereference(tun->xdp_prog);
1668 pad += XDP_PACKET_HEADROOM;
1669 buflen += SKB_DATA_ALIGN(len + pad);
1672 alloc_frag->offset = ALIGN((u64)alloc_frag->offset, SMP_CACHE_BYTES);
1673 if (unlikely(!skb_page_frag_refill(buflen, alloc_frag, GFP_KERNEL)))
1674 return ERR_PTR(-ENOMEM);
1676 buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
1677 copied = copy_page_from_iter(alloc_frag->page,
1678 alloc_frag->offset + pad,
1681 return ERR_PTR(-EFAULT);
1683 /* There's a small window that XDP may be set after the check
1684 * of xdp_prog above, this should be rare and for simplicity
1685 * we do XDP on skb in case the headroom is not enough.
1687 if (hdr->gso_type || !xdp_prog) {
1689 return __tun_build_skb(alloc_frag, buf, buflen, len, pad);
1696 xdp_prog = rcu_dereference(tun->xdp_prog);
1698 struct xdp_buff xdp;
1701 xdp.data_hard_start = buf;
1702 xdp.data = buf + pad;
1703 xdp_set_data_meta_invalid(&xdp);
1704 xdp.data_end = xdp.data + len;
1705 xdp.rxq = &tfile->xdp_rxq;
1707 act = bpf_prog_run_xdp(xdp_prog, &xdp);
1708 if (act == XDP_REDIRECT || act == XDP_TX) {
1709 get_page(alloc_frag->page);
1710 alloc_frag->offset += buflen;
1712 err = tun_xdp_act(tun, xdp_prog, &xdp, act);
1715 if (err == XDP_REDIRECT)
1717 if (err != XDP_PASS)
1720 pad = xdp.data - xdp.data_hard_start;
1721 len = xdp.data_end - xdp.data;
1726 return __tun_build_skb(alloc_frag, buf, buflen, len, pad);
1729 put_page(alloc_frag->page);
1736 /* Get packet from user space buffer */
1737 static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
1738 void *msg_control, struct iov_iter *from,
1739 int noblock, bool more)
1741 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
1742 struct sk_buff *skb;
1743 size_t total_len = iov_iter_count(from);
1744 size_t len = total_len, align = tun->align, linear;
1745 struct virtio_net_hdr gso = { 0 };
1746 struct tun_pcpu_stats *stats;
1749 bool zerocopy = false;
1753 bool frags = tun_napi_frags_enabled(tfile);
1755 if (!(tun->flags & IFF_NO_PI)) {
1756 if (len < sizeof(pi))
1760 if (!copy_from_iter_full(&pi, sizeof(pi), from))
1764 if (tun->flags & IFF_VNET_HDR) {
1765 int vnet_hdr_sz = READ_ONCE(tun->vnet_hdr_sz);
1767 if (len < vnet_hdr_sz)
1771 if (!copy_from_iter_full(&gso, sizeof(gso), from))
1774 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
1775 tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2 > tun16_to_cpu(tun, gso.hdr_len))
1776 gso.hdr_len = cpu_to_tun16(tun, tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2);
1778 if (tun16_to_cpu(tun, gso.hdr_len) > len)
1780 iov_iter_advance(from, vnet_hdr_sz - sizeof(gso));
1783 if ((tun->flags & TUN_TYPE_MASK) == IFF_TAP) {
1784 align += NET_IP_ALIGN;
1785 if (unlikely(len < ETH_HLEN ||
1786 (gso.hdr_len && tun16_to_cpu(tun, gso.hdr_len) < ETH_HLEN)))
1790 good_linear = SKB_MAX_HEAD(align);
1793 struct iov_iter i = *from;
1795 /* There are 256 bytes to be copied in skb, so there is
1796 * enough room for skb expand head in case it is used.
1797 * The rest of the buffer is mapped from userspace.
1799 copylen = gso.hdr_len ? tun16_to_cpu(tun, gso.hdr_len) : GOODCOPY_LEN;
1800 if (copylen > good_linear)
1801 copylen = good_linear;
1803 iov_iter_advance(&i, copylen);
1804 if (iov_iter_npages(&i, INT_MAX) <= MAX_SKB_FRAGS)
1808 if (!frags && tun_can_build_skb(tun, tfile, len, noblock, zerocopy)) {
1809 /* For the packet that is not easy to be processed
1810 * (e.g gso or jumbo packet), we will do it at after
1811 * skb was created with generic XDP routine.
1813 skb = tun_build_skb(tun, tfile, from, &gso, len, &skb_xdp);
1815 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1816 return PTR_ERR(skb);
1823 if (tun16_to_cpu(tun, gso.hdr_len) > good_linear)
1824 linear = good_linear;
1826 linear = tun16_to_cpu(tun, gso.hdr_len);
1830 mutex_lock(&tfile->napi_mutex);
1831 skb = tun_napi_alloc_frags(tfile, copylen, from);
1832 /* tun_napi_alloc_frags() enforces a layout for the skb.
1833 * If zerocopy is enabled, then this layout will be
1834 * overwritten by zerocopy_sg_from_iter().
1838 skb = tun_alloc_skb(tfile, align, copylen, linear,
1843 if (PTR_ERR(skb) != -EAGAIN)
1844 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1846 mutex_unlock(&tfile->napi_mutex);
1847 return PTR_ERR(skb);
1851 err = zerocopy_sg_from_iter(skb, from);
1853 err = skb_copy_datagram_from_iter(skb, 0, from, len);
1858 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1861 tfile->napi.skb = NULL;
1862 mutex_unlock(&tfile->napi_mutex);
1869 if (virtio_net_hdr_to_skb(skb, &gso, tun_is_little_endian(tun))) {
1870 this_cpu_inc(tun->pcpu_stats->rx_frame_errors);
1873 tfile->napi.skb = NULL;
1874 mutex_unlock(&tfile->napi_mutex);
1880 switch (tun->flags & TUN_TYPE_MASK) {
1882 if (tun->flags & IFF_NO_PI) {
1883 u8 ip_version = skb->len ? (skb->data[0] >> 4) : 0;
1885 switch (ip_version) {
1887 pi.proto = htons(ETH_P_IP);
1890 pi.proto = htons(ETH_P_IPV6);
1893 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1899 skb_reset_mac_header(skb);
1900 skb->protocol = pi.proto;
1901 skb->dev = tun->dev;
1905 skb->protocol = eth_type_trans(skb, tun->dev);
1909 /* copy skb_ubuf_info for callback when skb has no error */
1911 skb_shinfo(skb)->destructor_arg = msg_control;
1912 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
1913 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
1914 } else if (msg_control) {
1915 struct ubuf_info *uarg = msg_control;
1916 uarg->callback(uarg, false);
1919 skb_reset_network_header(skb);
1920 skb_probe_transport_header(skb);
1923 struct bpf_prog *xdp_prog;
1928 xdp_prog = rcu_dereference(tun->xdp_prog);
1930 ret = do_xdp_generic(xdp_prog, skb);
1931 if (ret != XDP_PASS) {
1941 /* Compute the costly rx hash only if needed for flow updates.
1942 * We may get a very small possibility of OOO during switching, not
1943 * worth to optimize.
1945 if (!rcu_access_pointer(tun->steering_prog) && tun->numqueues > 1 &&
1947 rxhash = __skb_get_hash_symmetric(skb);
1950 if (unlikely(!(tun->dev->flags & IFF_UP))) {
1957 /* Exercise flow dissector code path. */
1958 u32 headlen = eth_get_headlen(tun->dev, skb->data,
1961 if (unlikely(headlen > skb_headlen(skb))) {
1962 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1963 napi_free_frags(&tfile->napi);
1965 mutex_unlock(&tfile->napi_mutex);
1971 napi_gro_frags(&tfile->napi);
1973 mutex_unlock(&tfile->napi_mutex);
1974 } else if (tfile->napi_enabled) {
1975 struct sk_buff_head *queue = &tfile->sk.sk_write_queue;
1978 spin_lock_bh(&queue->lock);
1979 __skb_queue_tail(queue, skb);
1980 queue_len = skb_queue_len(queue);
1981 spin_unlock(&queue->lock);
1983 if (!more || queue_len > NAPI_POLL_WEIGHT)
1984 napi_schedule(&tfile->napi);
1987 } else if (!IS_ENABLED(CONFIG_4KSTACKS)) {
1988 tun_rx_batched(tun, tfile, skb, more);
1994 stats = get_cpu_ptr(tun->pcpu_stats);
1995 u64_stats_update_begin(&stats->syncp);
1996 stats->rx_packets++;
1997 stats->rx_bytes += len;
1998 u64_stats_update_end(&stats->syncp);
2002 tun_flow_update(tun, rxhash, tfile);
2007 static ssize_t tun_chr_write_iter(struct kiocb *iocb, struct iov_iter *from)
2009 struct file *file = iocb->ki_filp;
2010 struct tun_file *tfile = file->private_data;
2011 struct tun_struct *tun = tun_get(tfile);
2017 result = tun_get_user(tun, tfile, NULL, from,
2018 file->f_flags & O_NONBLOCK, false);
2024 static ssize_t tun_put_user_xdp(struct tun_struct *tun,
2025 struct tun_file *tfile,
2026 struct xdp_frame *xdp_frame,
2027 struct iov_iter *iter)
2029 int vnet_hdr_sz = 0;
2030 size_t size = xdp_frame->len;
2031 struct tun_pcpu_stats *stats;
2034 if (tun->flags & IFF_VNET_HDR) {
2035 struct virtio_net_hdr gso = { 0 };
2037 vnet_hdr_sz = READ_ONCE(tun->vnet_hdr_sz);
2038 if (unlikely(iov_iter_count(iter) < vnet_hdr_sz))
2040 if (unlikely(copy_to_iter(&gso, sizeof(gso), iter) !=
2043 iov_iter_advance(iter, vnet_hdr_sz - sizeof(gso));
2046 ret = copy_to_iter(xdp_frame->data, size, iter) + vnet_hdr_sz;
2048 stats = get_cpu_ptr(tun->pcpu_stats);
2049 u64_stats_update_begin(&stats->syncp);
2050 stats->tx_packets++;
2051 stats->tx_bytes += ret;
2052 u64_stats_update_end(&stats->syncp);
2053 put_cpu_ptr(tun->pcpu_stats);
2058 /* Put packet to the user space buffer */
2059 static ssize_t tun_put_user(struct tun_struct *tun,
2060 struct tun_file *tfile,
2061 struct sk_buff *skb,
2062 struct iov_iter *iter)
2064 struct tun_pi pi = { 0, skb->protocol };
2065 struct tun_pcpu_stats *stats;
2067 int vlan_offset = 0;
2069 int vnet_hdr_sz = 0;
2071 if (skb_vlan_tag_present(skb))
2072 vlan_hlen = VLAN_HLEN;
2074 if (tun->flags & IFF_VNET_HDR)
2075 vnet_hdr_sz = READ_ONCE(tun->vnet_hdr_sz);
2077 total = skb->len + vlan_hlen + vnet_hdr_sz;
2079 if (!(tun->flags & IFF_NO_PI)) {
2080 if (iov_iter_count(iter) < sizeof(pi))
2083 total += sizeof(pi);
2084 if (iov_iter_count(iter) < total) {
2085 /* Packet will be striped */
2086 pi.flags |= TUN_PKT_STRIP;
2089 if (copy_to_iter(&pi, sizeof(pi), iter) != sizeof(pi))
2094 struct virtio_net_hdr gso;
2096 if (iov_iter_count(iter) < vnet_hdr_sz)
2099 if (virtio_net_hdr_from_skb(skb, &gso,
2100 tun_is_little_endian(tun), true,
2102 struct skb_shared_info *sinfo = skb_shinfo(skb);
2103 pr_err("unexpected GSO type: "
2104 "0x%x, gso_size %d, hdr_len %d\n",
2105 sinfo->gso_type, tun16_to_cpu(tun, gso.gso_size),
2106 tun16_to_cpu(tun, gso.hdr_len));
2107 print_hex_dump(KERN_ERR, "tun: ",
2110 min((int)tun16_to_cpu(tun, gso.hdr_len), 64), true);
2115 if (copy_to_iter(&gso, sizeof(gso), iter) != sizeof(gso))
2118 iov_iter_advance(iter, vnet_hdr_sz - sizeof(gso));
2125 veth.h_vlan_proto = skb->vlan_proto;
2126 veth.h_vlan_TCI = htons(skb_vlan_tag_get(skb));
2128 vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto);
2130 ret = skb_copy_datagram_iter(skb, 0, iter, vlan_offset);
2131 if (ret || !iov_iter_count(iter))
2134 ret = copy_to_iter(&veth, sizeof(veth), iter);
2135 if (ret != sizeof(veth) || !iov_iter_count(iter))
2139 skb_copy_datagram_iter(skb, vlan_offset, iter, skb->len - vlan_offset);
2142 /* caller is in process context, */
2143 stats = get_cpu_ptr(tun->pcpu_stats);
2144 u64_stats_update_begin(&stats->syncp);
2145 stats->tx_packets++;
2146 stats->tx_bytes += skb->len + vlan_hlen;
2147 u64_stats_update_end(&stats->syncp);
2148 put_cpu_ptr(tun->pcpu_stats);
2153 static void *tun_ring_recv(struct tun_file *tfile, int noblock, int *err)
2155 DECLARE_WAITQUEUE(wait, current);
2159 ptr = ptr_ring_consume(&tfile->tx_ring);
2167 add_wait_queue(&tfile->socket.wq.wait, &wait);
2170 set_current_state(TASK_INTERRUPTIBLE);
2171 ptr = ptr_ring_consume(&tfile->tx_ring);
2174 if (signal_pending(current)) {
2175 error = -ERESTARTSYS;
2178 if (tfile->socket.sk->sk_shutdown & RCV_SHUTDOWN) {
2186 __set_current_state(TASK_RUNNING);
2187 remove_wait_queue(&tfile->socket.wq.wait, &wait);
2194 static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
2195 struct iov_iter *to,
2196 int noblock, void *ptr)
2201 tun_debug(KERN_INFO, tun, "tun_do_read\n");
2203 if (!iov_iter_count(to)) {
2209 /* Read frames from ring */
2210 ptr = tun_ring_recv(tfile, noblock, &err);
2215 if (tun_is_xdp_frame(ptr)) {
2216 struct xdp_frame *xdpf = tun_ptr_to_xdp(ptr);
2218 ret = tun_put_user_xdp(tun, tfile, xdpf, to);
2219 xdp_return_frame(xdpf);
2221 struct sk_buff *skb = ptr;
2223 ret = tun_put_user(tun, tfile, skb, to);
2224 if (unlikely(ret < 0))
2233 static ssize_t tun_chr_read_iter(struct kiocb *iocb, struct iov_iter *to)
2235 struct file *file = iocb->ki_filp;
2236 struct tun_file *tfile = file->private_data;
2237 struct tun_struct *tun = tun_get(tfile);
2238 ssize_t len = iov_iter_count(to), ret;
2242 ret = tun_do_read(tun, tfile, to, file->f_flags & O_NONBLOCK, NULL);
2243 ret = min_t(ssize_t, ret, len);
2250 static void tun_prog_free(struct rcu_head *rcu)
2252 struct tun_prog *prog = container_of(rcu, struct tun_prog, rcu);
2254 bpf_prog_destroy(prog->prog);
2258 static int __tun_set_ebpf(struct tun_struct *tun,
2259 struct tun_prog __rcu **prog_p,
2260 struct bpf_prog *prog)
2262 struct tun_prog *old, *new = NULL;
2265 new = kmalloc(sizeof(*new), GFP_KERNEL);
2271 spin_lock_bh(&tun->lock);
2272 old = rcu_dereference_protected(*prog_p,
2273 lockdep_is_held(&tun->lock));
2274 rcu_assign_pointer(*prog_p, new);
2275 spin_unlock_bh(&tun->lock);
2278 call_rcu(&old->rcu, tun_prog_free);
2283 static void tun_free_netdev(struct net_device *dev)
2285 struct tun_struct *tun = netdev_priv(dev);
2287 BUG_ON(!(list_empty(&tun->disabled)));
2288 free_percpu(tun->pcpu_stats);
2289 tun_flow_uninit(tun);
2290 security_tun_dev_free_security(tun->security);
2291 __tun_set_ebpf(tun, &tun->steering_prog, NULL);
2292 __tun_set_ebpf(tun, &tun->filter_prog, NULL);
2295 static void tun_setup(struct net_device *dev)
2297 struct tun_struct *tun = netdev_priv(dev);
2299 tun->owner = INVALID_UID;
2300 tun->group = INVALID_GID;
2301 tun_default_link_ksettings(dev, &tun->link_ksettings);
2303 dev->ethtool_ops = &tun_ethtool_ops;
2304 dev->needs_free_netdev = true;
2305 dev->priv_destructor = tun_free_netdev;
2306 /* We prefer our own queue length */
2307 dev->tx_queue_len = TUN_READQ_SIZE;
2310 /* Trivial set of netlink ops to allow deleting tun or tap
2311 * device with netlink.
2313 static int tun_validate(struct nlattr *tb[], struct nlattr *data[],
2314 struct netlink_ext_ack *extack)
2316 NL_SET_ERR_MSG(extack,
2317 "tun/tap creation via rtnetlink is not supported.");
2321 static size_t tun_get_size(const struct net_device *dev)
2323 BUILD_BUG_ON(sizeof(u32) != sizeof(uid_t));
2324 BUILD_BUG_ON(sizeof(u32) != sizeof(gid_t));
2326 return nla_total_size(sizeof(uid_t)) + /* OWNER */
2327 nla_total_size(sizeof(gid_t)) + /* GROUP */
2328 nla_total_size(sizeof(u8)) + /* TYPE */
2329 nla_total_size(sizeof(u8)) + /* PI */
2330 nla_total_size(sizeof(u8)) + /* VNET_HDR */
2331 nla_total_size(sizeof(u8)) + /* PERSIST */
2332 nla_total_size(sizeof(u8)) + /* MULTI_QUEUE */
2333 nla_total_size(sizeof(u32)) + /* NUM_QUEUES */
2334 nla_total_size(sizeof(u32)) + /* NUM_DISABLED_QUEUES */
2338 static int tun_fill_info(struct sk_buff *skb, const struct net_device *dev)
2340 struct tun_struct *tun = netdev_priv(dev);
2342 if (nla_put_u8(skb, IFLA_TUN_TYPE, tun->flags & TUN_TYPE_MASK))
2343 goto nla_put_failure;
2344 if (uid_valid(tun->owner) &&
2345 nla_put_u32(skb, IFLA_TUN_OWNER,
2346 from_kuid_munged(current_user_ns(), tun->owner)))
2347 goto nla_put_failure;
2348 if (gid_valid(tun->group) &&
2349 nla_put_u32(skb, IFLA_TUN_GROUP,
2350 from_kgid_munged(current_user_ns(), tun->group)))
2351 goto nla_put_failure;
2352 if (nla_put_u8(skb, IFLA_TUN_PI, !(tun->flags & IFF_NO_PI)))
2353 goto nla_put_failure;
2354 if (nla_put_u8(skb, IFLA_TUN_VNET_HDR, !!(tun->flags & IFF_VNET_HDR)))
2355 goto nla_put_failure;
2356 if (nla_put_u8(skb, IFLA_TUN_PERSIST, !!(tun->flags & IFF_PERSIST)))
2357 goto nla_put_failure;
2358 if (nla_put_u8(skb, IFLA_TUN_MULTI_QUEUE,
2359 !!(tun->flags & IFF_MULTI_QUEUE)))
2360 goto nla_put_failure;
2361 if (tun->flags & IFF_MULTI_QUEUE) {
2362 if (nla_put_u32(skb, IFLA_TUN_NUM_QUEUES, tun->numqueues))
2363 goto nla_put_failure;
2364 if (nla_put_u32(skb, IFLA_TUN_NUM_DISABLED_QUEUES,
2366 goto nla_put_failure;
2375 static struct rtnl_link_ops tun_link_ops __read_mostly = {
2377 .priv_size = sizeof(struct tun_struct),
2379 .validate = tun_validate,
2380 .get_size = tun_get_size,
2381 .fill_info = tun_fill_info,
2384 static void tun_sock_write_space(struct sock *sk)
2386 struct tun_file *tfile;
2387 wait_queue_head_t *wqueue;
2389 if (!sock_writeable(sk))
2392 if (!test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags))
2395 wqueue = sk_sleep(sk);
2396 if (wqueue && waitqueue_active(wqueue))
2397 wake_up_interruptible_sync_poll(wqueue, EPOLLOUT |
2398 EPOLLWRNORM | EPOLLWRBAND);
2400 tfile = container_of(sk, struct tun_file, sk);
2401 kill_fasync(&tfile->fasync, SIGIO, POLL_OUT);
2404 static void tun_put_page(struct tun_page *tpage)
2407 __page_frag_cache_drain(tpage->page, tpage->count);
2410 static int tun_xdp_one(struct tun_struct *tun,
2411 struct tun_file *tfile,
2412 struct xdp_buff *xdp, int *flush,
2413 struct tun_page *tpage)
2415 unsigned int datasize = xdp->data_end - xdp->data;
2416 struct tun_xdp_hdr *hdr = xdp->data_hard_start;
2417 struct virtio_net_hdr *gso = &hdr->gso;
2418 struct tun_pcpu_stats *stats;
2419 struct bpf_prog *xdp_prog;
2420 struct sk_buff *skb = NULL;
2421 u32 rxhash = 0, act;
2422 int buflen = hdr->buflen;
2424 bool skb_xdp = false;
2427 xdp_prog = rcu_dereference(tun->xdp_prog);
2429 if (gso->gso_type) {
2433 xdp_set_data_meta_invalid(xdp);
2434 xdp->rxq = &tfile->xdp_rxq;
2436 act = bpf_prog_run_xdp(xdp_prog, xdp);
2437 err = tun_xdp_act(tun, xdp_prog, xdp, act);
2439 put_page(virt_to_head_page(xdp->data));
2452 page = virt_to_head_page(xdp->data);
2453 if (tpage->page == page) {
2456 tun_put_page(tpage);
2465 skb = build_skb(xdp->data_hard_start, buflen);
2471 skb_reserve(skb, xdp->data - xdp->data_hard_start);
2472 skb_put(skb, xdp->data_end - xdp->data);
2474 if (virtio_net_hdr_to_skb(skb, gso, tun_is_little_endian(tun))) {
2475 this_cpu_inc(tun->pcpu_stats->rx_frame_errors);
2481 skb->protocol = eth_type_trans(skb, tun->dev);
2482 skb_reset_network_header(skb);
2483 skb_probe_transport_header(skb);
2486 err = do_xdp_generic(xdp_prog, skb);
2487 if (err != XDP_PASS)
2491 if (!rcu_dereference(tun->steering_prog) && tun->numqueues > 1 &&
2493 rxhash = __skb_get_hash_symmetric(skb);
2495 skb_record_rx_queue(skb, tfile->queue_index);
2496 netif_receive_skb(skb);
2498 /* No need for get_cpu_ptr() here since this function is
2499 * always called with bh disabled
2501 stats = this_cpu_ptr(tun->pcpu_stats);
2502 u64_stats_update_begin(&stats->syncp);
2503 stats->rx_packets++;
2504 stats->rx_bytes += datasize;
2505 u64_stats_update_end(&stats->syncp);
2508 tun_flow_update(tun, rxhash, tfile);
2514 static int tun_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
2517 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
2518 struct tun_struct *tun = tun_get(tfile);
2519 struct tun_msg_ctl *ctl = m->msg_control;
2520 struct xdp_buff *xdp;
2525 if (ctl && (ctl->type == TUN_MSG_PTR)) {
2526 struct tun_page tpage;
2530 memset(&tpage, 0, sizeof(tpage));
2535 for (i = 0; i < n; i++) {
2536 xdp = &((struct xdp_buff *)ctl->ptr)[i];
2537 tun_xdp_one(tun, tfile, xdp, &flush, &tpage);
2546 tun_put_page(&tpage);
2552 ret = tun_get_user(tun, tfile, ctl ? ctl->ptr : NULL, &m->msg_iter,
2553 m->msg_flags & MSG_DONTWAIT,
2554 m->msg_flags & MSG_MORE);
2560 static int tun_recvmsg(struct socket *sock, struct msghdr *m, size_t total_len,
2563 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
2564 struct tun_struct *tun = tun_get(tfile);
2565 void *ptr = m->msg_control;
2573 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC|MSG_ERRQUEUE)) {
2577 if (flags & MSG_ERRQUEUE) {
2578 ret = sock_recv_errqueue(sock->sk, m, total_len,
2579 SOL_PACKET, TUN_TX_TIMESTAMP);
2582 ret = tun_do_read(tun, tfile, &m->msg_iter, flags & MSG_DONTWAIT, ptr);
2583 if (ret > (ssize_t)total_len) {
2584 m->msg_flags |= MSG_TRUNC;
2585 ret = flags & MSG_TRUNC ? ret : total_len;
2598 static int tun_ptr_peek_len(void *ptr)
2601 if (tun_is_xdp_frame(ptr)) {
2602 struct xdp_frame *xdpf = tun_ptr_to_xdp(ptr);
2606 return __skb_array_len_with_tag(ptr);
2612 static int tun_peek_len(struct socket *sock)
2614 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
2615 struct tun_struct *tun;
2618 tun = tun_get(tfile);
2622 ret = PTR_RING_PEEK_CALL(&tfile->tx_ring, tun_ptr_peek_len);
2628 /* Ops structure to mimic raw sockets with tun */
2629 static const struct proto_ops tun_socket_ops = {
2630 .peek_len = tun_peek_len,
2631 .sendmsg = tun_sendmsg,
2632 .recvmsg = tun_recvmsg,
2635 static struct proto tun_proto = {
2637 .owner = THIS_MODULE,
2638 .obj_size = sizeof(struct tun_file),
2641 static int tun_flags(struct tun_struct *tun)
2643 return tun->flags & (TUN_FEATURES | IFF_PERSIST | IFF_TUN | IFF_TAP);
2646 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
2649 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
2650 return sprintf(buf, "0x%x\n", tun_flags(tun));
2653 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
2656 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
2657 return uid_valid(tun->owner)?
2658 sprintf(buf, "%u\n",
2659 from_kuid_munged(current_user_ns(), tun->owner)):
2660 sprintf(buf, "-1\n");
2663 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
2666 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
2667 return gid_valid(tun->group) ?
2668 sprintf(buf, "%u\n",
2669 from_kgid_munged(current_user_ns(), tun->group)):
2670 sprintf(buf, "-1\n");
2673 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
2674 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
2675 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
2677 static struct attribute *tun_dev_attrs[] = {
2678 &dev_attr_tun_flags.attr,
2679 &dev_attr_owner.attr,
2680 &dev_attr_group.attr,
2684 static const struct attribute_group tun_attr_group = {
2685 .attrs = tun_dev_attrs
2688 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
2690 struct tun_struct *tun;
2691 struct tun_file *tfile = file->private_data;
2692 struct net_device *dev;
2695 if (tfile->detached)
2698 if ((ifr->ifr_flags & IFF_NAPI_FRAGS)) {
2699 if (!capable(CAP_NET_ADMIN))
2702 if (!(ifr->ifr_flags & IFF_NAPI) ||
2703 (ifr->ifr_flags & TUN_TYPE_MASK) != IFF_TAP)
2707 dev = __dev_get_by_name(net, ifr->ifr_name);
2709 if (ifr->ifr_flags & IFF_TUN_EXCL)
2711 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
2712 tun = netdev_priv(dev);
2713 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
2714 tun = netdev_priv(dev);
2718 if (!!(ifr->ifr_flags & IFF_MULTI_QUEUE) !=
2719 !!(tun->flags & IFF_MULTI_QUEUE))
2722 if (tun_not_capable(tun))
2724 err = security_tun_dev_open(tun->security);
2728 err = tun_attach(tun, file, ifr->ifr_flags & IFF_NOFILTER,
2729 ifr->ifr_flags & IFF_NAPI,
2730 ifr->ifr_flags & IFF_NAPI_FRAGS);
2734 if (tun->flags & IFF_MULTI_QUEUE &&
2735 (tun->numqueues + tun->numdisabled > 1)) {
2736 /* One or more queue has already been attached, no need
2737 * to initialize the device again.
2739 netdev_state_change(dev);
2743 tun->flags = (tun->flags & ~TUN_FEATURES) |
2744 (ifr->ifr_flags & TUN_FEATURES);
2746 netdev_state_change(dev);
2749 unsigned long flags = 0;
2750 int queues = ifr->ifr_flags & IFF_MULTI_QUEUE ?
2753 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
2755 err = security_tun_dev_create();
2760 if (ifr->ifr_flags & IFF_TUN) {
2764 } else if (ifr->ifr_flags & IFF_TAP) {
2772 name = ifr->ifr_name;
2774 dev = alloc_netdev_mqs(sizeof(struct tun_struct), name,
2775 NET_NAME_UNKNOWN, tun_setup, queues,
2780 err = dev_get_valid_name(net, dev, name);
2784 dev_net_set(dev, net);
2785 dev->rtnl_link_ops = &tun_link_ops;
2786 dev->ifindex = tfile->ifindex;
2787 dev->sysfs_groups[0] = &tun_attr_group;
2789 tun = netdev_priv(dev);
2792 tun->txflt.count = 0;
2793 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
2795 tun->align = NET_SKB_PAD;
2796 tun->filter_attached = false;
2797 tun->sndbuf = tfile->socket.sk->sk_sndbuf;
2798 tun->rx_batched = 0;
2799 RCU_INIT_POINTER(tun->steering_prog, NULL);
2801 tun->pcpu_stats = netdev_alloc_pcpu_stats(struct tun_pcpu_stats);
2802 if (!tun->pcpu_stats) {
2807 spin_lock_init(&tun->lock);
2809 err = security_tun_dev_alloc_security(&tun->security);
2816 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
2817 TUN_USER_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
2818 NETIF_F_HW_VLAN_STAG_TX;
2819 dev->features = dev->hw_features | NETIF_F_LLTX;
2820 dev->vlan_features = dev->features &
2821 ~(NETIF_F_HW_VLAN_CTAG_TX |
2822 NETIF_F_HW_VLAN_STAG_TX);
2824 tun->flags = (tun->flags & ~TUN_FEATURES) |
2825 (ifr->ifr_flags & TUN_FEATURES);
2827 INIT_LIST_HEAD(&tun->disabled);
2828 err = tun_attach(tun, file, false, ifr->ifr_flags & IFF_NAPI,
2829 ifr->ifr_flags & IFF_NAPI_FRAGS);
2833 err = register_netdevice(tun->dev);
2838 netif_carrier_on(tun->dev);
2840 tun_debug(KERN_INFO, tun, "tun_set_iff\n");
2842 /* Make sure persistent devices do not get stuck in
2845 if (netif_running(tun->dev))
2846 netif_tx_wake_all_queues(tun->dev);
2848 strcpy(ifr->ifr_name, tun->dev->name);
2852 tun_detach_all(dev);
2853 /* register_netdevice() already called tun_free_netdev() */
2857 tun_flow_uninit(tun);
2858 security_tun_dev_free_security(tun->security);
2860 free_percpu(tun->pcpu_stats);
2866 static void tun_get_iff(struct tun_struct *tun, struct ifreq *ifr)
2868 tun_debug(KERN_INFO, tun, "tun_get_iff\n");
2870 strcpy(ifr->ifr_name, tun->dev->name);
2872 ifr->ifr_flags = tun_flags(tun);
2876 /* This is like a cut-down ethtool ops, except done via tun fd so no
2877 * privs required. */
2878 static int set_offload(struct tun_struct *tun, unsigned long arg)
2880 netdev_features_t features = 0;
2882 if (arg & TUN_F_CSUM) {
2883 features |= NETIF_F_HW_CSUM;
2886 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
2887 if (arg & TUN_F_TSO_ECN) {
2888 features |= NETIF_F_TSO_ECN;
2889 arg &= ~TUN_F_TSO_ECN;
2891 if (arg & TUN_F_TSO4)
2892 features |= NETIF_F_TSO;
2893 if (arg & TUN_F_TSO6)
2894 features |= NETIF_F_TSO6;
2895 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
2901 /* This gives the user a way to test for new features in future by
2902 * trying to set them. */
2906 tun->set_features = features;
2907 tun->dev->wanted_features &= ~TUN_USER_FEATURES;
2908 tun->dev->wanted_features |= features;
2909 netdev_update_features(tun->dev);
2914 static void tun_detach_filter(struct tun_struct *tun, int n)
2917 struct tun_file *tfile;
2919 for (i = 0; i < n; i++) {
2920 tfile = rtnl_dereference(tun->tfiles[i]);
2921 lock_sock(tfile->socket.sk);
2922 sk_detach_filter(tfile->socket.sk);
2923 release_sock(tfile->socket.sk);
2926 tun->filter_attached = false;
2929 static int tun_attach_filter(struct tun_struct *tun)
2932 struct tun_file *tfile;
2934 for (i = 0; i < tun->numqueues; i++) {
2935 tfile = rtnl_dereference(tun->tfiles[i]);
2936 lock_sock(tfile->socket.sk);
2937 ret = sk_attach_filter(&tun->fprog, tfile->socket.sk);
2938 release_sock(tfile->socket.sk);
2940 tun_detach_filter(tun, i);
2945 tun->filter_attached = true;
2949 static void tun_set_sndbuf(struct tun_struct *tun)
2951 struct tun_file *tfile;
2954 for (i = 0; i < tun->numqueues; i++) {
2955 tfile = rtnl_dereference(tun->tfiles[i]);
2956 tfile->socket.sk->sk_sndbuf = tun->sndbuf;
2960 static int tun_set_queue(struct file *file, struct ifreq *ifr)
2962 struct tun_file *tfile = file->private_data;
2963 struct tun_struct *tun;
2968 if (ifr->ifr_flags & IFF_ATTACH_QUEUE) {
2969 tun = tfile->detached;
2974 ret = security_tun_dev_attach_queue(tun->security);
2977 ret = tun_attach(tun, file, false, tun->flags & IFF_NAPI,
2978 tun->flags & IFF_NAPI_FRAGS);
2979 } else if (ifr->ifr_flags & IFF_DETACH_QUEUE) {
2980 tun = rtnl_dereference(tfile->tun);
2981 if (!tun || !(tun->flags & IFF_MULTI_QUEUE) || tfile->detached)
2984 __tun_detach(tfile, false);
2989 netdev_state_change(tun->dev);
2996 static int tun_set_ebpf(struct tun_struct *tun, struct tun_prog **prog_p,
2999 struct bpf_prog *prog;
3002 if (copy_from_user(&fd, data, sizeof(fd)))
3008 prog = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER);
3010 return PTR_ERR(prog);
3013 return __tun_set_ebpf(tun, prog_p, prog);
3016 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
3017 unsigned long arg, int ifreq_len)
3019 struct tun_file *tfile = file->private_data;
3020 struct net *net = sock_net(&tfile->sk);
3021 struct tun_struct *tun;
3022 void __user* argp = (void __user*)arg;
3023 unsigned int ifindex, carrier;
3031 bool do_notify = false;
3033 if (cmd == TUNSETIFF || cmd == TUNSETQUEUE ||
3034 (_IOC_TYPE(cmd) == SOCK_IOC_TYPE && cmd != SIOCGSKNS)) {
3035 if (copy_from_user(&ifr, argp, ifreq_len))
3038 memset(&ifr, 0, sizeof(ifr));
3040 if (cmd == TUNGETFEATURES) {
3041 /* Currently this just means: "what IFF flags are valid?".
3042 * This is needed because we never checked for invalid flags on
3045 return put_user(IFF_TUN | IFF_TAP | TUN_FEATURES,
3046 (unsigned int __user*)argp);
3047 } else if (cmd == TUNSETQUEUE) {
3048 return tun_set_queue(file, &ifr);
3049 } else if (cmd == SIOCGSKNS) {
3050 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
3052 return open_related_ns(&net->ns, get_net_ns);
3058 tun = tun_get(tfile);
3059 if (cmd == TUNSETIFF) {
3064 ifr.ifr_name[IFNAMSIZ-1] = '\0';
3066 ret = tun_set_iff(net, file, &ifr);
3071 if (copy_to_user(argp, &ifr, ifreq_len))
3075 if (cmd == TUNSETIFINDEX) {
3081 if (copy_from_user(&ifindex, argp, sizeof(ifindex)))
3085 tfile->ifindex = ifindex;
3093 tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %u\n", cmd);
3095 net = dev_net(tun->dev);
3099 tun_get_iff(tun, &ifr);
3101 if (tfile->detached)
3102 ifr.ifr_flags |= IFF_DETACH_QUEUE;
3103 if (!tfile->socket.sk->sk_filter)
3104 ifr.ifr_flags |= IFF_NOFILTER;
3106 if (copy_to_user(argp, &ifr, ifreq_len))
3111 /* Disable/Enable checksum */
3113 /* [unimplemented] */
3114 tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n",
3115 arg ? "disabled" : "enabled");
3119 /* Disable/Enable persist mode. Keep an extra reference to the
3120 * module to prevent the module being unprobed.
3122 if (arg && !(tun->flags & IFF_PERSIST)) {
3123 tun->flags |= IFF_PERSIST;
3124 __module_get(THIS_MODULE);
3127 if (!arg && (tun->flags & IFF_PERSIST)) {
3128 tun->flags &= ~IFF_PERSIST;
3129 module_put(THIS_MODULE);
3133 tun_debug(KERN_INFO, tun, "persist %s\n",
3134 arg ? "enabled" : "disabled");
3138 /* Set owner of the device */
3139 owner = make_kuid(current_user_ns(), arg);
3140 if (!uid_valid(owner)) {
3146 tun_debug(KERN_INFO, tun, "owner set to %u\n",
3147 from_kuid(&init_user_ns, tun->owner));
3151 /* Set group of the device */
3152 group = make_kgid(current_user_ns(), arg);
3153 if (!gid_valid(group)) {
3159 tun_debug(KERN_INFO, tun, "group set to %u\n",
3160 from_kgid(&init_user_ns, tun->group));
3164 /* Only allow setting the type when the interface is down */
3165 if (tun->dev->flags & IFF_UP) {
3166 tun_debug(KERN_INFO, tun,
3167 "Linktype set failed because interface is up\n");
3170 tun->dev->type = (int) arg;
3171 tun_debug(KERN_INFO, tun, "linktype set to %d\n",
3183 ret = set_offload(tun, arg);
3186 case TUNSETTXFILTER:
3187 /* Can be set only for TAPs */
3189 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
3191 ret = update_filter(&tun->txflt, (void __user *)arg);
3195 /* Get hw address */
3196 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
3197 ifr.ifr_hwaddr.sa_family = tun->dev->type;
3198 if (copy_to_user(argp, &ifr, ifreq_len))
3203 /* Set hw address */
3204 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n",
3205 ifr.ifr_hwaddr.sa_data);
3207 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr, NULL);
3211 sndbuf = tfile->socket.sk->sk_sndbuf;
3212 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
3217 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
3226 tun->sndbuf = sndbuf;
3227 tun_set_sndbuf(tun);
3230 case TUNGETVNETHDRSZ:
3231 vnet_hdr_sz = tun->vnet_hdr_sz;
3232 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
3236 case TUNSETVNETHDRSZ:
3237 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
3241 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
3246 tun->vnet_hdr_sz = vnet_hdr_sz;
3250 le = !!(tun->flags & TUN_VNET_LE);
3251 if (put_user(le, (int __user *)argp))
3256 if (get_user(le, (int __user *)argp)) {
3261 tun->flags |= TUN_VNET_LE;
3263 tun->flags &= ~TUN_VNET_LE;
3267 ret = tun_get_vnet_be(tun, argp);
3271 ret = tun_set_vnet_be(tun, argp);
3274 case TUNATTACHFILTER:
3275 /* Can be set only for TAPs */
3277 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
3280 if (copy_from_user(&tun->fprog, argp, sizeof(tun->fprog)))
3283 ret = tun_attach_filter(tun);
3286 case TUNDETACHFILTER:
3287 /* Can be set only for TAPs */
3289 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
3292 tun_detach_filter(tun, tun->numqueues);
3297 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
3300 if (copy_to_user(argp, &tun->fprog, sizeof(tun->fprog)))
3305 case TUNSETSTEERINGEBPF:
3306 ret = tun_set_ebpf(tun, &tun->steering_prog, argp);
3309 case TUNSETFILTEREBPF:
3310 ret = tun_set_ebpf(tun, &tun->filter_prog, argp);
3315 if (copy_from_user(&carrier, argp, sizeof(carrier)))
3318 ret = tun_net_change_carrier(tun->dev, (bool)carrier);
3321 case TUNGETDEVNETNS:
3323 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
3325 ret = open_related_ns(&net->ns, get_net_ns);
3334 netdev_state_change(tun->dev);
3343 static long tun_chr_ioctl(struct file *file,
3344 unsigned int cmd, unsigned long arg)
3346 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
3349 #ifdef CONFIG_COMPAT
3350 static long tun_chr_compat_ioctl(struct file *file,
3351 unsigned int cmd, unsigned long arg)
3356 case TUNSETTXFILTER:
3361 arg = (unsigned long)compat_ptr(arg);
3364 arg = (compat_ulong_t)arg;
3369 * compat_ifreq is shorter than ifreq, so we must not access beyond
3370 * the end of that structure. All fields that are used in this
3371 * driver are compatible though, we don't need to convert the
3374 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
3376 #endif /* CONFIG_COMPAT */
3378 static int tun_chr_fasync(int fd, struct file *file, int on)
3380 struct tun_file *tfile = file->private_data;
3383 if ((ret = fasync_helper(fd, file, on, &tfile->fasync)) < 0)
3387 __f_setown(file, task_pid(current), PIDTYPE_TGID, 0);
3388 tfile->flags |= TUN_FASYNC;
3390 tfile->flags &= ~TUN_FASYNC;
3396 static int tun_chr_open(struct inode *inode, struct file * file)
3398 struct net *net = current->nsproxy->net_ns;
3399 struct tun_file *tfile;
3401 DBG1(KERN_INFO, "tunX: tun_chr_open\n");
3403 tfile = (struct tun_file *)sk_alloc(net, AF_UNSPEC, GFP_KERNEL,
3407 if (ptr_ring_init(&tfile->tx_ring, 0, GFP_KERNEL)) {
3408 sk_free(&tfile->sk);
3412 mutex_init(&tfile->napi_mutex);
3413 RCU_INIT_POINTER(tfile->tun, NULL);
3417 init_waitqueue_head(&tfile->socket.wq.wait);
3419 tfile->socket.file = file;
3420 tfile->socket.ops = &tun_socket_ops;
3422 sock_init_data(&tfile->socket, &tfile->sk);
3424 tfile->sk.sk_write_space = tun_sock_write_space;
3425 tfile->sk.sk_sndbuf = INT_MAX;
3427 file->private_data = tfile;
3428 INIT_LIST_HEAD(&tfile->next);
3430 sock_set_flag(&tfile->sk, SOCK_ZEROCOPY);
3435 static int tun_chr_close(struct inode *inode, struct file *file)
3437 struct tun_file *tfile = file->private_data;
3439 tun_detach(tfile, true);
3444 #ifdef CONFIG_PROC_FS
3445 static void tun_chr_show_fdinfo(struct seq_file *m, struct file *file)
3447 struct tun_file *tfile = file->private_data;
3448 struct tun_struct *tun;
3451 memset(&ifr, 0, sizeof(ifr));
3454 tun = tun_get(tfile);
3456 tun_get_iff(tun, &ifr);
3462 seq_printf(m, "iff:\t%s\n", ifr.ifr_name);
3466 static const struct file_operations tun_fops = {
3467 .owner = THIS_MODULE,
3468 .llseek = no_llseek,
3469 .read_iter = tun_chr_read_iter,
3470 .write_iter = tun_chr_write_iter,
3471 .poll = tun_chr_poll,
3472 .unlocked_ioctl = tun_chr_ioctl,
3473 #ifdef CONFIG_COMPAT
3474 .compat_ioctl = tun_chr_compat_ioctl,
3476 .open = tun_chr_open,
3477 .release = tun_chr_close,
3478 .fasync = tun_chr_fasync,
3479 #ifdef CONFIG_PROC_FS
3480 .show_fdinfo = tun_chr_show_fdinfo,
3484 static struct miscdevice tun_miscdev = {
3487 .nodename = "net/tun",
3491 /* ethtool interface */
3493 static void tun_default_link_ksettings(struct net_device *dev,
3494 struct ethtool_link_ksettings *cmd)
3496 ethtool_link_ksettings_zero_link_mode(cmd, supported);
3497 ethtool_link_ksettings_zero_link_mode(cmd, advertising);
3498 cmd->base.speed = SPEED_10;
3499 cmd->base.duplex = DUPLEX_FULL;
3500 cmd->base.port = PORT_TP;
3501 cmd->base.phy_address = 0;
3502 cmd->base.autoneg = AUTONEG_DISABLE;
3505 static int tun_get_link_ksettings(struct net_device *dev,
3506 struct ethtool_link_ksettings *cmd)
3508 struct tun_struct *tun = netdev_priv(dev);
3510 memcpy(cmd, &tun->link_ksettings, sizeof(*cmd));
3514 static int tun_set_link_ksettings(struct net_device *dev,
3515 const struct ethtool_link_ksettings *cmd)
3517 struct tun_struct *tun = netdev_priv(dev);
3519 memcpy(&tun->link_ksettings, cmd, sizeof(*cmd));
3523 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
3525 struct tun_struct *tun = netdev_priv(dev);
3527 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
3528 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
3530 switch (tun->flags & TUN_TYPE_MASK) {
3532 strlcpy(info->bus_info, "tun", sizeof(info->bus_info));
3535 strlcpy(info->bus_info, "tap", sizeof(info->bus_info));
3540 static u32 tun_get_msglevel(struct net_device *dev)
3543 struct tun_struct *tun = netdev_priv(dev);
3550 static void tun_set_msglevel(struct net_device *dev, u32 value)
3553 struct tun_struct *tun = netdev_priv(dev);
3558 static int tun_get_coalesce(struct net_device *dev,
3559 struct ethtool_coalesce *ec)
3561 struct tun_struct *tun = netdev_priv(dev);
3563 ec->rx_max_coalesced_frames = tun->rx_batched;
3568 static int tun_set_coalesce(struct net_device *dev,
3569 struct ethtool_coalesce *ec)
3571 struct tun_struct *tun = netdev_priv(dev);
3573 if (ec->rx_max_coalesced_frames > NAPI_POLL_WEIGHT)
3574 tun->rx_batched = NAPI_POLL_WEIGHT;
3576 tun->rx_batched = ec->rx_max_coalesced_frames;
3581 static const struct ethtool_ops tun_ethtool_ops = {
3582 .get_drvinfo = tun_get_drvinfo,
3583 .get_msglevel = tun_get_msglevel,
3584 .set_msglevel = tun_set_msglevel,
3585 .get_link = ethtool_op_get_link,
3586 .get_ts_info = ethtool_op_get_ts_info,
3587 .get_coalesce = tun_get_coalesce,
3588 .set_coalesce = tun_set_coalesce,
3589 .get_link_ksettings = tun_get_link_ksettings,
3590 .set_link_ksettings = tun_set_link_ksettings,
3593 static int tun_queue_resize(struct tun_struct *tun)
3595 struct net_device *dev = tun->dev;
3596 struct tun_file *tfile;
3597 struct ptr_ring **rings;
3598 int n = tun->numqueues + tun->numdisabled;
3601 rings = kmalloc_array(n, sizeof(*rings), GFP_KERNEL);
3605 for (i = 0; i < tun->numqueues; i++) {
3606 tfile = rtnl_dereference(tun->tfiles[i]);
3607 rings[i] = &tfile->tx_ring;
3609 list_for_each_entry(tfile, &tun->disabled, next)
3610 rings[i++] = &tfile->tx_ring;
3612 ret = ptr_ring_resize_multiple(rings, n,
3613 dev->tx_queue_len, GFP_KERNEL,
3620 static int tun_device_event(struct notifier_block *unused,
3621 unsigned long event, void *ptr)
3623 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3624 struct tun_struct *tun = netdev_priv(dev);
3627 if (dev->rtnl_link_ops != &tun_link_ops)
3631 case NETDEV_CHANGE_TX_QUEUE_LEN:
3632 if (tun_queue_resize(tun))
3636 for (i = 0; i < tun->numqueues; i++) {
3637 struct tun_file *tfile;
3639 tfile = rtnl_dereference(tun->tfiles[i]);
3640 tfile->socket.sk->sk_write_space(tfile->socket.sk);
3650 static struct notifier_block tun_notifier_block __read_mostly = {
3651 .notifier_call = tun_device_event,
3654 static int __init tun_init(void)
3658 pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
3660 ret = rtnl_link_register(&tun_link_ops);
3662 pr_err("Can't register link_ops\n");
3666 ret = misc_register(&tun_miscdev);
3668 pr_err("Can't register misc device %d\n", TUN_MINOR);
3672 ret = register_netdevice_notifier(&tun_notifier_block);
3674 pr_err("Can't register netdevice notifier\n");
3681 misc_deregister(&tun_miscdev);
3683 rtnl_link_unregister(&tun_link_ops);
3688 static void tun_cleanup(void)
3690 misc_deregister(&tun_miscdev);
3691 rtnl_link_unregister(&tun_link_ops);
3692 unregister_netdevice_notifier(&tun_notifier_block);
3695 /* Get an underlying socket object from tun file. Returns error unless file is
3696 * attached to a device. The returned object works like a packet socket, it
3697 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
3698 * holding a reference to the file for as long as the socket is in use. */
3699 struct socket *tun_get_socket(struct file *file)
3701 struct tun_file *tfile;
3702 if (file->f_op != &tun_fops)
3703 return ERR_PTR(-EINVAL);
3704 tfile = file->private_data;
3706 return ERR_PTR(-EBADFD);
3707 return &tfile->socket;
3709 EXPORT_SYMBOL_GPL(tun_get_socket);
3711 struct ptr_ring *tun_get_tx_ring(struct file *file)
3713 struct tun_file *tfile;
3715 if (file->f_op != &tun_fops)
3716 return ERR_PTR(-EINVAL);
3717 tfile = file->private_data;
3719 return ERR_PTR(-EBADFD);
3720 return &tfile->tx_ring;
3722 EXPORT_SYMBOL_GPL(tun_get_tx_ring);
3724 module_init(tun_init);
3725 module_exit(tun_cleanup);
3726 MODULE_DESCRIPTION(DRV_DESCRIPTION);
3727 MODULE_AUTHOR(DRV_COPYRIGHT);
3728 MODULE_LICENSE("GPL");
3729 MODULE_ALIAS_MISCDEV(TUN_MINOR);
3730 MODULE_ALIAS("devname:net/tun");