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;
164 struct tun_struct __rcu *tun;
165 struct fasync_struct *fasync;
166 /* only used for fasnyc */
170 unsigned int ifindex;
172 struct napi_struct napi;
174 bool napi_frags_enabled;
175 struct mutex napi_mutex; /* Protects access to the above napi */
176 struct list_head next;
177 struct tun_struct *detached;
178 struct ptr_ring tx_ring;
179 struct xdp_rxq_info xdp_rxq;
187 struct tun_flow_entry {
188 struct hlist_node hash_link;
190 struct tun_struct *tun;
195 unsigned long updated ____cacheline_aligned_in_smp;
198 #define TUN_NUM_FLOW_ENTRIES 1024
199 #define TUN_MASK_FLOW_ENTRIES (TUN_NUM_FLOW_ENTRIES - 1)
203 struct bpf_prog *prog;
206 /* Since the socket were moved to tun_file, to preserve the behavior of persist
207 * device, socket filter, sndbuf and vnet header size were restore when the
208 * file were attached to a persist device.
211 struct tun_file __rcu *tfiles[MAX_TAP_QUEUES];
212 unsigned int numqueues;
217 struct net_device *dev;
218 netdev_features_t set_features;
219 #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \
225 struct tap_filter txflt;
226 struct sock_fprog fprog;
227 /* protected by rtnl lock */
228 bool filter_attached;
233 struct hlist_head flows[TUN_NUM_FLOW_ENTRIES];
234 struct timer_list flow_gc_timer;
235 unsigned long ageing_time;
236 unsigned int numdisabled;
237 struct list_head disabled;
241 struct tun_pcpu_stats __percpu *pcpu_stats;
242 struct bpf_prog __rcu *xdp_prog;
243 struct tun_prog __rcu *steering_prog;
244 struct tun_prog __rcu *filter_prog;
245 struct ethtool_link_ksettings link_ksettings;
253 bool tun_is_xdp_frame(void *ptr)
255 return (unsigned long)ptr & TUN_XDP_FLAG;
257 EXPORT_SYMBOL(tun_is_xdp_frame);
259 void *tun_xdp_to_ptr(void *ptr)
261 return (void *)((unsigned long)ptr | TUN_XDP_FLAG);
263 EXPORT_SYMBOL(tun_xdp_to_ptr);
265 void *tun_ptr_to_xdp(void *ptr)
267 return (void *)((unsigned long)ptr & ~TUN_XDP_FLAG);
269 EXPORT_SYMBOL(tun_ptr_to_xdp);
271 static int tun_napi_receive(struct napi_struct *napi, int budget)
273 struct tun_file *tfile = container_of(napi, struct tun_file, napi);
274 struct sk_buff_head *queue = &tfile->sk.sk_write_queue;
275 struct sk_buff_head process_queue;
279 __skb_queue_head_init(&process_queue);
281 spin_lock(&queue->lock);
282 skb_queue_splice_tail_init(queue, &process_queue);
283 spin_unlock(&queue->lock);
285 while (received < budget && (skb = __skb_dequeue(&process_queue))) {
286 napi_gro_receive(napi, skb);
290 if (!skb_queue_empty(&process_queue)) {
291 spin_lock(&queue->lock);
292 skb_queue_splice(&process_queue, queue);
293 spin_unlock(&queue->lock);
299 static int tun_napi_poll(struct napi_struct *napi, int budget)
301 unsigned int received;
303 received = tun_napi_receive(napi, budget);
305 if (received < budget)
306 napi_complete_done(napi, received);
311 static void tun_napi_init(struct tun_struct *tun, struct tun_file *tfile,
312 bool napi_en, bool napi_frags)
314 tfile->napi_enabled = napi_en;
315 tfile->napi_frags_enabled = napi_en && napi_frags;
317 netif_napi_add(tun->dev, &tfile->napi, tun_napi_poll,
319 napi_enable(&tfile->napi);
323 static void tun_napi_disable(struct tun_file *tfile)
325 if (tfile->napi_enabled)
326 napi_disable(&tfile->napi);
329 static void tun_napi_del(struct tun_file *tfile)
331 if (tfile->napi_enabled)
332 netif_napi_del(&tfile->napi);
335 static bool tun_napi_frags_enabled(const struct tun_file *tfile)
337 return tfile->napi_frags_enabled;
340 #ifdef CONFIG_TUN_VNET_CROSS_LE
341 static inline bool tun_legacy_is_little_endian(struct tun_struct *tun)
343 return tun->flags & TUN_VNET_BE ? false :
344 virtio_legacy_is_little_endian();
347 static long tun_get_vnet_be(struct tun_struct *tun, int __user *argp)
349 int be = !!(tun->flags & TUN_VNET_BE);
351 if (put_user(be, argp))
357 static long tun_set_vnet_be(struct tun_struct *tun, int __user *argp)
361 if (get_user(be, argp))
365 tun->flags |= TUN_VNET_BE;
367 tun->flags &= ~TUN_VNET_BE;
372 static inline bool tun_legacy_is_little_endian(struct tun_struct *tun)
374 return virtio_legacy_is_little_endian();
377 static long tun_get_vnet_be(struct tun_struct *tun, int __user *argp)
382 static long tun_set_vnet_be(struct tun_struct *tun, int __user *argp)
386 #endif /* CONFIG_TUN_VNET_CROSS_LE */
388 static inline bool tun_is_little_endian(struct tun_struct *tun)
390 return tun->flags & TUN_VNET_LE ||
391 tun_legacy_is_little_endian(tun);
394 static inline u16 tun16_to_cpu(struct tun_struct *tun, __virtio16 val)
396 return __virtio16_to_cpu(tun_is_little_endian(tun), val);
399 static inline __virtio16 cpu_to_tun16(struct tun_struct *tun, u16 val)
401 return __cpu_to_virtio16(tun_is_little_endian(tun), val);
404 static inline u32 tun_hashfn(u32 rxhash)
406 return rxhash & TUN_MASK_FLOW_ENTRIES;
409 static struct tun_flow_entry *tun_flow_find(struct hlist_head *head, u32 rxhash)
411 struct tun_flow_entry *e;
413 hlist_for_each_entry_rcu(e, head, hash_link) {
414 if (e->rxhash == rxhash)
420 static struct tun_flow_entry *tun_flow_create(struct tun_struct *tun,
421 struct hlist_head *head,
422 u32 rxhash, u16 queue_index)
424 struct tun_flow_entry *e = kmalloc(sizeof(*e), GFP_ATOMIC);
427 tun_debug(KERN_INFO, tun, "create flow: hash %u index %u\n",
428 rxhash, queue_index);
429 e->updated = jiffies;
432 e->queue_index = queue_index;
434 hlist_add_head_rcu(&e->hash_link, head);
440 static void tun_flow_delete(struct tun_struct *tun, struct tun_flow_entry *e)
442 tun_debug(KERN_INFO, tun, "delete flow: hash %u index %u\n",
443 e->rxhash, e->queue_index);
444 hlist_del_rcu(&e->hash_link);
449 static void tun_flow_flush(struct tun_struct *tun)
453 spin_lock_bh(&tun->lock);
454 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
455 struct tun_flow_entry *e;
456 struct hlist_node *n;
458 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link)
459 tun_flow_delete(tun, e);
461 spin_unlock_bh(&tun->lock);
464 static void tun_flow_delete_by_queue(struct tun_struct *tun, u16 queue_index)
468 spin_lock_bh(&tun->lock);
469 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
470 struct tun_flow_entry *e;
471 struct hlist_node *n;
473 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
474 if (e->queue_index == queue_index)
475 tun_flow_delete(tun, e);
478 spin_unlock_bh(&tun->lock);
481 static void tun_flow_cleanup(struct timer_list *t)
483 struct tun_struct *tun = from_timer(tun, t, flow_gc_timer);
484 unsigned long delay = tun->ageing_time;
485 unsigned long next_timer = jiffies + delay;
486 unsigned long count = 0;
489 tun_debug(KERN_INFO, tun, "tun_flow_cleanup\n");
491 spin_lock(&tun->lock);
492 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
493 struct tun_flow_entry *e;
494 struct hlist_node *n;
496 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
497 unsigned long this_timer;
499 this_timer = e->updated + delay;
500 if (time_before_eq(this_timer, jiffies)) {
501 tun_flow_delete(tun, e);
505 if (time_before(this_timer, next_timer))
506 next_timer = this_timer;
511 mod_timer(&tun->flow_gc_timer, round_jiffies_up(next_timer));
512 spin_unlock(&tun->lock);
515 static void tun_flow_update(struct tun_struct *tun, u32 rxhash,
516 struct tun_file *tfile)
518 struct hlist_head *head;
519 struct tun_flow_entry *e;
520 unsigned long delay = tun->ageing_time;
521 u16 queue_index = tfile->queue_index;
523 head = &tun->flows[tun_hashfn(rxhash)];
527 e = tun_flow_find(head, rxhash);
529 /* TODO: keep queueing to old queue until it's empty? */
530 if (e->queue_index != queue_index)
531 e->queue_index = queue_index;
532 if (e->updated != jiffies)
533 e->updated = jiffies;
534 sock_rps_record_flow_hash(e->rps_rxhash);
536 spin_lock_bh(&tun->lock);
537 if (!tun_flow_find(head, rxhash) &&
538 tun->flow_count < MAX_TAP_FLOWS)
539 tun_flow_create(tun, head, rxhash, queue_index);
541 if (!timer_pending(&tun->flow_gc_timer))
542 mod_timer(&tun->flow_gc_timer,
543 round_jiffies_up(jiffies + delay));
544 spin_unlock_bh(&tun->lock);
551 * Save the hash received in the stack receive path and update the
552 * flow_hash table accordingly.
554 static inline void tun_flow_save_rps_rxhash(struct tun_flow_entry *e, u32 hash)
556 if (unlikely(e->rps_rxhash != hash))
557 e->rps_rxhash = hash;
560 /* We try to identify a flow through its rxhash. The reason that
561 * we do not check rxq no. is because some cards(e.g 82599), chooses
562 * the rxq based on the txq where the last packet of the flow comes. As
563 * the userspace application move between processors, we may get a
564 * different rxq no. here.
566 static u16 tun_automq_select_queue(struct tun_struct *tun, struct sk_buff *skb)
568 struct tun_flow_entry *e;
572 numqueues = READ_ONCE(tun->numqueues);
574 txq = __skb_get_hash_symmetric(skb);
575 e = tun_flow_find(&tun->flows[tun_hashfn(txq)], txq);
577 tun_flow_save_rps_rxhash(e, txq);
578 txq = e->queue_index;
580 /* use multiply and shift instead of expensive divide */
581 txq = ((u64)txq * numqueues) >> 32;
587 static u16 tun_ebpf_select_queue(struct tun_struct *tun, struct sk_buff *skb)
589 struct tun_prog *prog;
593 numqueues = READ_ONCE(tun->numqueues);
597 prog = rcu_dereference(tun->steering_prog);
599 ret = bpf_prog_run_clear_cb(prog->prog, skb);
601 return ret % numqueues;
604 static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb,
605 struct net_device *sb_dev)
607 struct tun_struct *tun = netdev_priv(dev);
611 if (rcu_dereference(tun->steering_prog))
612 ret = tun_ebpf_select_queue(tun, skb);
614 ret = tun_automq_select_queue(tun, skb);
620 static inline bool tun_not_capable(struct tun_struct *tun)
622 const struct cred *cred = current_cred();
623 struct net *net = dev_net(tun->dev);
625 return ((uid_valid(tun->owner) && !uid_eq(cred->euid, tun->owner)) ||
626 (gid_valid(tun->group) && !in_egroup_p(tun->group))) &&
627 !ns_capable(net->user_ns, CAP_NET_ADMIN);
630 static void tun_set_real_num_queues(struct tun_struct *tun)
632 netif_set_real_num_tx_queues(tun->dev, tun->numqueues);
633 netif_set_real_num_rx_queues(tun->dev, tun->numqueues);
636 static void tun_disable_queue(struct tun_struct *tun, struct tun_file *tfile)
638 tfile->detached = tun;
639 list_add_tail(&tfile->next, &tun->disabled);
643 static struct tun_struct *tun_enable_queue(struct tun_file *tfile)
645 struct tun_struct *tun = tfile->detached;
647 tfile->detached = NULL;
648 list_del_init(&tfile->next);
653 void tun_ptr_free(void *ptr)
657 if (tun_is_xdp_frame(ptr)) {
658 struct xdp_frame *xdpf = tun_ptr_to_xdp(ptr);
660 xdp_return_frame(xdpf);
662 __skb_array_destroy_skb(ptr);
665 EXPORT_SYMBOL_GPL(tun_ptr_free);
667 static void tun_queue_purge(struct tun_file *tfile)
671 while ((ptr = ptr_ring_consume(&tfile->tx_ring)) != NULL)
674 skb_queue_purge(&tfile->sk.sk_write_queue);
675 skb_queue_purge(&tfile->sk.sk_error_queue);
678 static void __tun_detach(struct tun_file *tfile, bool clean)
680 struct tun_file *ntfile;
681 struct tun_struct *tun;
683 tun = rtnl_dereference(tfile->tun);
686 tun_napi_disable(tfile);
690 if (tun && !tfile->detached) {
691 u16 index = tfile->queue_index;
692 BUG_ON(index >= tun->numqueues);
694 rcu_assign_pointer(tun->tfiles[index],
695 tun->tfiles[tun->numqueues - 1]);
696 ntfile = rtnl_dereference(tun->tfiles[index]);
697 ntfile->queue_index = index;
698 rcu_assign_pointer(tun->tfiles[tun->numqueues - 1],
703 RCU_INIT_POINTER(tfile->tun, NULL);
704 sock_put(&tfile->sk);
706 tun_disable_queue(tun, tfile);
709 tun_flow_delete_by_queue(tun, tun->numqueues + 1);
710 /* Drop read queue */
711 tun_queue_purge(tfile);
712 tun_set_real_num_queues(tun);
713 } else if (tfile->detached && clean) {
714 tun = tun_enable_queue(tfile);
715 sock_put(&tfile->sk);
719 if (tun && tun->numqueues == 0 && tun->numdisabled == 0) {
720 netif_carrier_off(tun->dev);
722 if (!(tun->flags & IFF_PERSIST) &&
723 tun->dev->reg_state == NETREG_REGISTERED)
724 unregister_netdevice(tun->dev);
727 xdp_rxq_info_unreg(&tfile->xdp_rxq);
728 ptr_ring_cleanup(&tfile->tx_ring, tun_ptr_free);
729 sock_put(&tfile->sk);
733 static void tun_detach(struct tun_file *tfile, bool clean)
735 struct tun_struct *tun;
736 struct net_device *dev;
739 tun = rtnl_dereference(tfile->tun);
740 dev = tun ? tun->dev : NULL;
741 __tun_detach(tfile, clean);
743 netdev_state_change(dev);
747 static void tun_detach_all(struct net_device *dev)
749 struct tun_struct *tun = netdev_priv(dev);
750 struct tun_file *tfile, *tmp;
751 int i, n = tun->numqueues;
753 for (i = 0; i < n; i++) {
754 tfile = rtnl_dereference(tun->tfiles[i]);
756 tun_napi_disable(tfile);
757 tfile->socket.sk->sk_shutdown = RCV_SHUTDOWN;
758 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
759 RCU_INIT_POINTER(tfile->tun, NULL);
762 list_for_each_entry(tfile, &tun->disabled, next) {
763 tfile->socket.sk->sk_shutdown = RCV_SHUTDOWN;
764 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
765 RCU_INIT_POINTER(tfile->tun, NULL);
767 BUG_ON(tun->numqueues != 0);
770 for (i = 0; i < n; i++) {
771 tfile = rtnl_dereference(tun->tfiles[i]);
773 /* Drop read queue */
774 tun_queue_purge(tfile);
775 xdp_rxq_info_unreg(&tfile->xdp_rxq);
776 sock_put(&tfile->sk);
778 list_for_each_entry_safe(tfile, tmp, &tun->disabled, next) {
779 tun_enable_queue(tfile);
780 tun_queue_purge(tfile);
781 xdp_rxq_info_unreg(&tfile->xdp_rxq);
782 sock_put(&tfile->sk);
784 BUG_ON(tun->numdisabled != 0);
786 if (tun->flags & IFF_PERSIST)
787 module_put(THIS_MODULE);
790 static int tun_attach(struct tun_struct *tun, struct file *file,
791 bool skip_filter, bool napi, bool napi_frags)
793 struct tun_file *tfile = file->private_data;
794 struct net_device *dev = tun->dev;
797 err = security_tun_dev_attach(tfile->socket.sk, tun->security);
802 if (rtnl_dereference(tfile->tun) && !tfile->detached)
806 if (!(tun->flags & IFF_MULTI_QUEUE) && tun->numqueues == 1)
810 if (!tfile->detached &&
811 tun->numqueues + tun->numdisabled == MAX_TAP_QUEUES)
816 /* Re-attach the filter to persist device */
817 if (!skip_filter && (tun->filter_attached == true)) {
818 lock_sock(tfile->socket.sk);
819 err = sk_attach_filter(&tun->fprog, tfile->socket.sk);
820 release_sock(tfile->socket.sk);
825 if (!tfile->detached &&
826 ptr_ring_resize(&tfile->tx_ring, dev->tx_queue_len,
827 GFP_KERNEL, tun_ptr_free)) {
832 tfile->queue_index = tun->numqueues;
833 tfile->socket.sk->sk_shutdown &= ~RCV_SHUTDOWN;
835 if (tfile->detached) {
836 /* Re-attach detached tfile, updating XDP queue_index */
837 WARN_ON(!xdp_rxq_info_is_reg(&tfile->xdp_rxq));
839 if (tfile->xdp_rxq.queue_index != tfile->queue_index)
840 tfile->xdp_rxq.queue_index = tfile->queue_index;
842 /* Setup XDP RX-queue info, for new tfile getting attached */
843 err = xdp_rxq_info_reg(&tfile->xdp_rxq,
844 tun->dev, tfile->queue_index);
847 err = xdp_rxq_info_reg_mem_model(&tfile->xdp_rxq,
848 MEM_TYPE_PAGE_SHARED, NULL);
850 xdp_rxq_info_unreg(&tfile->xdp_rxq);
856 if (tfile->detached) {
857 tun_enable_queue(tfile);
859 sock_hold(&tfile->sk);
860 tun_napi_init(tun, tfile, napi, napi_frags);
863 if (rtnl_dereference(tun->xdp_prog))
864 sock_set_flag(&tfile->sk, SOCK_XDP);
866 /* device is allowed to go away first, so no need to hold extra
870 /* Publish tfile->tun and tun->tfiles only after we've fully
871 * initialized tfile; otherwise we risk using half-initialized
874 rcu_assign_pointer(tfile->tun, tun);
875 rcu_assign_pointer(tun->tfiles[tun->numqueues], tfile);
877 tun_set_real_num_queues(tun);
882 static struct tun_struct *tun_get(struct tun_file *tfile)
884 struct tun_struct *tun;
887 tun = rcu_dereference(tfile->tun);
895 static void tun_put(struct tun_struct *tun)
901 static void addr_hash_set(u32 *mask, const u8 *addr)
903 int n = ether_crc(ETH_ALEN, addr) >> 26;
904 mask[n >> 5] |= (1 << (n & 31));
907 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
909 int n = ether_crc(ETH_ALEN, addr) >> 26;
910 return mask[n >> 5] & (1 << (n & 31));
913 static int update_filter(struct tap_filter *filter, void __user *arg)
915 struct { u8 u[ETH_ALEN]; } *addr;
916 struct tun_filter uf;
917 int err, alen, n, nexact;
919 if (copy_from_user(&uf, arg, sizeof(uf)))
928 alen = ETH_ALEN * uf.count;
929 addr = memdup_user(arg + sizeof(uf), alen);
931 return PTR_ERR(addr);
933 /* The filter is updated without holding any locks. Which is
934 * perfectly safe. We disable it first and in the worst
935 * case we'll accept a few undesired packets. */
939 /* Use first set of addresses as an exact filter */
940 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
941 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
945 /* Remaining multicast addresses are hashed,
946 * unicast will leave the filter disabled. */
947 memset(filter->mask, 0, sizeof(filter->mask));
948 for (; n < uf.count; n++) {
949 if (!is_multicast_ether_addr(addr[n].u)) {
950 err = 0; /* no filter */
953 addr_hash_set(filter->mask, addr[n].u);
956 /* For ALLMULTI just set the mask to all ones.
957 * This overrides the mask populated above. */
958 if ((uf.flags & TUN_FLT_ALLMULTI))
959 memset(filter->mask, ~0, sizeof(filter->mask));
961 /* Now enable the filter */
963 filter->count = nexact;
965 /* Return the number of exact filters */
972 /* Returns: 0 - drop, !=0 - accept */
973 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
975 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
977 struct ethhdr *eh = (struct ethhdr *) skb->data;
981 for (i = 0; i < filter->count; i++)
982 if (ether_addr_equal(eh->h_dest, filter->addr[i]))
985 /* Inexact match (multicast only) */
986 if (is_multicast_ether_addr(eh->h_dest))
987 return addr_hash_test(filter->mask, eh->h_dest);
993 * Checks whether the packet is accepted or not.
994 * Returns: 0 - drop, !=0 - accept
996 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
1001 return run_filter(filter, skb);
1004 /* Network device part of the driver */
1006 static const struct ethtool_ops tun_ethtool_ops;
1008 /* Net device detach from fd. */
1009 static void tun_net_uninit(struct net_device *dev)
1011 tun_detach_all(dev);
1014 /* Net device open. */
1015 static int tun_net_open(struct net_device *dev)
1017 struct tun_struct *tun = netdev_priv(dev);
1020 netif_tx_start_all_queues(dev);
1022 for (i = 0; i < tun->numqueues; i++) {
1023 struct tun_file *tfile;
1025 tfile = rtnl_dereference(tun->tfiles[i]);
1026 tfile->socket.sk->sk_write_space(tfile->socket.sk);
1032 /* Net device close. */
1033 static int tun_net_close(struct net_device *dev)
1035 netif_tx_stop_all_queues(dev);
1039 /* Net device start xmit */
1040 static void tun_automq_xmit(struct tun_struct *tun, struct sk_buff *skb)
1043 if (tun->numqueues == 1 && static_branch_unlikely(&rps_needed)) {
1044 /* Select queue was not called for the skbuff, so we extract the
1045 * RPS hash and save it into the flow_table here.
1047 struct tun_flow_entry *e;
1050 rxhash = __skb_get_hash_symmetric(skb);
1051 e = tun_flow_find(&tun->flows[tun_hashfn(rxhash)], rxhash);
1053 tun_flow_save_rps_rxhash(e, rxhash);
1058 static unsigned int run_ebpf_filter(struct tun_struct *tun,
1059 struct sk_buff *skb,
1062 struct tun_prog *prog = rcu_dereference(tun->filter_prog);
1065 len = bpf_prog_run_clear_cb(prog->prog, skb);
1070 /* Net device start xmit */
1071 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
1073 struct tun_struct *tun = netdev_priv(dev);
1074 int txq = skb->queue_mapping;
1075 struct tun_file *tfile;
1079 tfile = rcu_dereference(tun->tfiles[txq]);
1081 /* Drop packet if interface is not attached */
1085 if (!rcu_dereference(tun->steering_prog))
1086 tun_automq_xmit(tun, skb);
1088 tun_debug(KERN_INFO, tun, "tun_net_xmit %d\n", skb->len);
1092 /* Drop if the filter does not like it.
1093 * This is a noop if the filter is disabled.
1094 * Filter can be enabled only for the TAP devices. */
1095 if (!check_filter(&tun->txflt, skb))
1098 if (tfile->socket.sk->sk_filter &&
1099 sk_filter(tfile->socket.sk, skb))
1102 len = run_ebpf_filter(tun, skb, len);
1103 if (len == 0 || pskb_trim(skb, len))
1106 if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
1109 skb_tx_timestamp(skb);
1111 /* Orphan the skb - required as we might hang on to it
1112 * for indefinite time.
1118 if (ptr_ring_produce(&tfile->tx_ring, skb))
1121 /* Notify and wake up reader process */
1122 if (tfile->flags & TUN_FASYNC)
1123 kill_fasync(&tfile->fasync, SIGIO, POLL_IN);
1124 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
1127 return NETDEV_TX_OK;
1130 this_cpu_inc(tun->pcpu_stats->tx_dropped);
1134 return NET_XMIT_DROP;
1137 static void tun_net_mclist(struct net_device *dev)
1140 * This callback is supposed to deal with mc filter in
1141 * _rx_ path and has nothing to do with the _tx_ path.
1142 * In rx path we always accept everything userspace gives us.
1146 static netdev_features_t tun_net_fix_features(struct net_device *dev,
1147 netdev_features_t features)
1149 struct tun_struct *tun = netdev_priv(dev);
1151 return (features & tun->set_features) | (features & ~TUN_USER_FEATURES);
1154 static void tun_set_headroom(struct net_device *dev, int new_hr)
1156 struct tun_struct *tun = netdev_priv(dev);
1158 if (new_hr < NET_SKB_PAD)
1159 new_hr = NET_SKB_PAD;
1161 tun->align = new_hr;
1165 tun_net_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
1167 u32 rx_dropped = 0, tx_dropped = 0, rx_frame_errors = 0;
1168 struct tun_struct *tun = netdev_priv(dev);
1169 struct tun_pcpu_stats *p;
1172 for_each_possible_cpu(i) {
1173 u64 rxpackets, rxbytes, txpackets, txbytes;
1176 p = per_cpu_ptr(tun->pcpu_stats, i);
1178 start = u64_stats_fetch_begin(&p->syncp);
1179 rxpackets = p->rx_packets;
1180 rxbytes = p->rx_bytes;
1181 txpackets = p->tx_packets;
1182 txbytes = p->tx_bytes;
1183 } while (u64_stats_fetch_retry(&p->syncp, start));
1185 stats->rx_packets += rxpackets;
1186 stats->rx_bytes += rxbytes;
1187 stats->tx_packets += txpackets;
1188 stats->tx_bytes += txbytes;
1191 rx_dropped += p->rx_dropped;
1192 rx_frame_errors += p->rx_frame_errors;
1193 tx_dropped += p->tx_dropped;
1195 stats->rx_dropped = rx_dropped;
1196 stats->rx_frame_errors = rx_frame_errors;
1197 stats->tx_dropped = tx_dropped;
1200 static int tun_xdp_set(struct net_device *dev, struct bpf_prog *prog,
1201 struct netlink_ext_ack *extack)
1203 struct tun_struct *tun = netdev_priv(dev);
1204 struct tun_file *tfile;
1205 struct bpf_prog *old_prog;
1208 old_prog = rtnl_dereference(tun->xdp_prog);
1209 rcu_assign_pointer(tun->xdp_prog, prog);
1211 bpf_prog_put(old_prog);
1213 for (i = 0; i < tun->numqueues; i++) {
1214 tfile = rtnl_dereference(tun->tfiles[i]);
1216 sock_set_flag(&tfile->sk, SOCK_XDP);
1218 sock_reset_flag(&tfile->sk, SOCK_XDP);
1220 list_for_each_entry(tfile, &tun->disabled, next) {
1222 sock_set_flag(&tfile->sk, SOCK_XDP);
1224 sock_reset_flag(&tfile->sk, SOCK_XDP);
1230 static u32 tun_xdp_query(struct net_device *dev)
1232 struct tun_struct *tun = netdev_priv(dev);
1233 const struct bpf_prog *xdp_prog;
1235 xdp_prog = rtnl_dereference(tun->xdp_prog);
1237 return xdp_prog->aux->id;
1242 static int tun_xdp(struct net_device *dev, struct netdev_bpf *xdp)
1244 switch (xdp->command) {
1245 case XDP_SETUP_PROG:
1246 return tun_xdp_set(dev, xdp->prog, xdp->extack);
1247 case XDP_QUERY_PROG:
1248 xdp->prog_id = tun_xdp_query(dev);
1255 static int tun_net_change_carrier(struct net_device *dev, bool new_carrier)
1258 struct tun_struct *tun = netdev_priv(dev);
1260 if (!tun->numqueues)
1263 netif_carrier_on(dev);
1265 netif_carrier_off(dev);
1270 static const struct net_device_ops tun_netdev_ops = {
1271 .ndo_uninit = tun_net_uninit,
1272 .ndo_open = tun_net_open,
1273 .ndo_stop = tun_net_close,
1274 .ndo_start_xmit = tun_net_xmit,
1275 .ndo_fix_features = tun_net_fix_features,
1276 .ndo_select_queue = tun_select_queue,
1277 .ndo_set_rx_headroom = tun_set_headroom,
1278 .ndo_get_stats64 = tun_net_get_stats64,
1279 .ndo_change_carrier = tun_net_change_carrier,
1282 static void __tun_xdp_flush_tfile(struct tun_file *tfile)
1284 /* Notify and wake up reader process */
1285 if (tfile->flags & TUN_FASYNC)
1286 kill_fasync(&tfile->fasync, SIGIO, POLL_IN);
1287 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
1290 static int tun_xdp_xmit(struct net_device *dev, int n,
1291 struct xdp_frame **frames, u32 flags)
1293 struct tun_struct *tun = netdev_priv(dev);
1294 struct tun_file *tfile;
1300 if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
1306 numqueues = READ_ONCE(tun->numqueues);
1309 return -ENXIO; /* Caller will free/return all frames */
1312 tfile = rcu_dereference(tun->tfiles[smp_processor_id() %
1314 if (unlikely(!tfile))
1317 spin_lock(&tfile->tx_ring.producer_lock);
1318 for (i = 0; i < n; i++) {
1319 struct xdp_frame *xdp = frames[i];
1320 /* Encode the XDP flag into lowest bit for consumer to differ
1321 * XDP buffer from sk_buff.
1323 void *frame = tun_xdp_to_ptr(xdp);
1325 if (__ptr_ring_produce(&tfile->tx_ring, frame)) {
1326 this_cpu_inc(tun->pcpu_stats->tx_dropped);
1327 xdp_return_frame_rx_napi(xdp);
1331 spin_unlock(&tfile->tx_ring.producer_lock);
1333 if (flags & XDP_XMIT_FLUSH)
1334 __tun_xdp_flush_tfile(tfile);
1340 static int tun_xdp_tx(struct net_device *dev, struct xdp_buff *xdp)
1342 struct xdp_frame *frame = convert_to_xdp_frame(xdp);
1344 if (unlikely(!frame))
1347 return tun_xdp_xmit(dev, 1, &frame, XDP_XMIT_FLUSH);
1350 static const struct net_device_ops tap_netdev_ops = {
1351 .ndo_uninit = tun_net_uninit,
1352 .ndo_open = tun_net_open,
1353 .ndo_stop = tun_net_close,
1354 .ndo_start_xmit = tun_net_xmit,
1355 .ndo_fix_features = tun_net_fix_features,
1356 .ndo_set_rx_mode = tun_net_mclist,
1357 .ndo_set_mac_address = eth_mac_addr,
1358 .ndo_validate_addr = eth_validate_addr,
1359 .ndo_select_queue = tun_select_queue,
1360 .ndo_features_check = passthru_features_check,
1361 .ndo_set_rx_headroom = tun_set_headroom,
1362 .ndo_get_stats64 = tun_net_get_stats64,
1364 .ndo_xdp_xmit = tun_xdp_xmit,
1365 .ndo_change_carrier = tun_net_change_carrier,
1368 static void tun_flow_init(struct tun_struct *tun)
1372 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++)
1373 INIT_HLIST_HEAD(&tun->flows[i]);
1375 tun->ageing_time = TUN_FLOW_EXPIRE;
1376 timer_setup(&tun->flow_gc_timer, tun_flow_cleanup, 0);
1377 mod_timer(&tun->flow_gc_timer,
1378 round_jiffies_up(jiffies + tun->ageing_time));
1381 static void tun_flow_uninit(struct tun_struct *tun)
1383 del_timer_sync(&tun->flow_gc_timer);
1384 tun_flow_flush(tun);
1388 #define MAX_MTU 65535
1390 /* Initialize net device. */
1391 static void tun_net_init(struct net_device *dev)
1393 struct tun_struct *tun = netdev_priv(dev);
1395 switch (tun->flags & TUN_TYPE_MASK) {
1397 dev->netdev_ops = &tun_netdev_ops;
1399 /* Point-to-Point TUN Device */
1400 dev->hard_header_len = 0;
1404 /* Zero header length */
1405 dev->type = ARPHRD_NONE;
1406 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1410 dev->netdev_ops = &tap_netdev_ops;
1411 /* Ethernet TAP Device */
1413 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1414 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1416 eth_hw_addr_random(dev);
1421 dev->min_mtu = MIN_MTU;
1422 dev->max_mtu = MAX_MTU - dev->hard_header_len;
1425 static bool tun_sock_writeable(struct tun_struct *tun, struct tun_file *tfile)
1427 struct sock *sk = tfile->socket.sk;
1429 return (tun->dev->flags & IFF_UP) && sock_writeable(sk);
1432 /* Character device part */
1435 static __poll_t tun_chr_poll(struct file *file, poll_table *wait)
1437 struct tun_file *tfile = file->private_data;
1438 struct tun_struct *tun = tun_get(tfile);
1445 sk = tfile->socket.sk;
1447 tun_debug(KERN_INFO, tun, "tun_chr_poll\n");
1449 poll_wait(file, sk_sleep(sk), wait);
1451 if (!ptr_ring_empty(&tfile->tx_ring))
1452 mask |= EPOLLIN | EPOLLRDNORM;
1454 /* Make sure SOCKWQ_ASYNC_NOSPACE is set if not writable to
1455 * guarantee EPOLLOUT to be raised by either here or
1456 * tun_sock_write_space(). Then process could get notification
1457 * after it writes to a down device and meets -EIO.
1459 if (tun_sock_writeable(tun, tfile) ||
1460 (!test_and_set_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
1461 tun_sock_writeable(tun, tfile)))
1462 mask |= EPOLLOUT | EPOLLWRNORM;
1464 if (tun->dev->reg_state != NETREG_REGISTERED)
1471 static struct sk_buff *tun_napi_alloc_frags(struct tun_file *tfile,
1473 const struct iov_iter *it)
1475 struct sk_buff *skb;
1480 if (it->nr_segs > MAX_SKB_FRAGS + 1)
1481 return ERR_PTR(-ENOMEM);
1484 skb = napi_get_frags(&tfile->napi);
1487 return ERR_PTR(-ENOMEM);
1489 linear = iov_iter_single_seg_count(it);
1490 err = __skb_grow(skb, linear);
1495 skb->data_len = len - linear;
1496 skb->truesize += skb->data_len;
1498 for (i = 1; i < it->nr_segs; i++) {
1499 size_t fragsz = it->iov[i].iov_len;
1503 if (fragsz == 0 || fragsz > PAGE_SIZE) {
1507 frag = netdev_alloc_frag(fragsz);
1512 page = virt_to_head_page(frag);
1513 skb_fill_page_desc(skb, i - 1, page,
1514 frag - page_address(page), fragsz);
1519 /* frees skb and all frags allocated with napi_alloc_frag() */
1520 napi_free_frags(&tfile->napi);
1521 return ERR_PTR(err);
1524 /* prepad is the amount to reserve at front. len is length after that.
1525 * linear is a hint as to how much to copy (usually headers). */
1526 static struct sk_buff *tun_alloc_skb(struct tun_file *tfile,
1527 size_t prepad, size_t len,
1528 size_t linear, int noblock)
1530 struct sock *sk = tfile->socket.sk;
1531 struct sk_buff *skb;
1534 /* Under a page? Don't bother with paged skb. */
1535 if (prepad + len < PAGE_SIZE || !linear)
1538 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
1541 return ERR_PTR(err);
1543 skb_reserve(skb, prepad);
1544 skb_put(skb, linear);
1545 skb->data_len = len - linear;
1546 skb->len += len - linear;
1551 static void tun_rx_batched(struct tun_struct *tun, struct tun_file *tfile,
1552 struct sk_buff *skb, int more)
1554 struct sk_buff_head *queue = &tfile->sk.sk_write_queue;
1555 struct sk_buff_head process_queue;
1556 u32 rx_batched = tun->rx_batched;
1559 if (!rx_batched || (!more && skb_queue_empty(queue))) {
1561 skb_record_rx_queue(skb, tfile->queue_index);
1562 netif_receive_skb(skb);
1567 spin_lock(&queue->lock);
1568 if (!more || skb_queue_len(queue) == rx_batched) {
1569 __skb_queue_head_init(&process_queue);
1570 skb_queue_splice_tail_init(queue, &process_queue);
1573 __skb_queue_tail(queue, skb);
1575 spin_unlock(&queue->lock);
1578 struct sk_buff *nskb;
1581 while ((nskb = __skb_dequeue(&process_queue))) {
1582 skb_record_rx_queue(nskb, tfile->queue_index);
1583 netif_receive_skb(nskb);
1585 skb_record_rx_queue(skb, tfile->queue_index);
1586 netif_receive_skb(skb);
1591 static bool tun_can_build_skb(struct tun_struct *tun, struct tun_file *tfile,
1592 int len, int noblock, bool zerocopy)
1594 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
1597 if (tfile->socket.sk->sk_sndbuf != INT_MAX)
1606 if (SKB_DATA_ALIGN(len + TUN_RX_PAD) +
1607 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) > PAGE_SIZE)
1613 static struct sk_buff *__tun_build_skb(struct page_frag *alloc_frag, char *buf,
1614 int buflen, int len, int pad)
1616 struct sk_buff *skb = build_skb(buf, buflen);
1619 return ERR_PTR(-ENOMEM);
1621 skb_reserve(skb, pad);
1624 get_page(alloc_frag->page);
1625 alloc_frag->offset += buflen;
1630 static int tun_xdp_act(struct tun_struct *tun, struct bpf_prog *xdp_prog,
1631 struct xdp_buff *xdp, u32 act)
1637 err = xdp_do_redirect(tun->dev, xdp, xdp_prog);
1642 err = tun_xdp_tx(tun->dev, xdp);
1649 bpf_warn_invalid_xdp_action(act);
1652 trace_xdp_exception(tun->dev, xdp_prog, act);
1655 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1662 static struct sk_buff *tun_build_skb(struct tun_struct *tun,
1663 struct tun_file *tfile,
1664 struct iov_iter *from,
1665 struct virtio_net_hdr *hdr,
1666 int len, int *skb_xdp)
1668 struct page_frag *alloc_frag = ¤t->task_frag;
1669 struct bpf_prog *xdp_prog;
1670 int buflen = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
1673 int pad = TUN_RX_PAD;
1677 xdp_prog = rcu_dereference(tun->xdp_prog);
1679 pad += XDP_PACKET_HEADROOM;
1680 buflen += SKB_DATA_ALIGN(len + pad);
1683 alloc_frag->offset = ALIGN((u64)alloc_frag->offset, SMP_CACHE_BYTES);
1684 if (unlikely(!skb_page_frag_refill(buflen, alloc_frag, GFP_KERNEL)))
1685 return ERR_PTR(-ENOMEM);
1687 buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
1688 copied = copy_page_from_iter(alloc_frag->page,
1689 alloc_frag->offset + pad,
1692 return ERR_PTR(-EFAULT);
1694 /* There's a small window that XDP may be set after the check
1695 * of xdp_prog above, this should be rare and for simplicity
1696 * we do XDP on skb in case the headroom is not enough.
1698 if (hdr->gso_type || !xdp_prog) {
1700 return __tun_build_skb(alloc_frag, buf, buflen, len, pad);
1707 xdp_prog = rcu_dereference(tun->xdp_prog);
1709 struct xdp_buff xdp;
1712 xdp.data_hard_start = buf;
1713 xdp.data = buf + pad;
1714 xdp_set_data_meta_invalid(&xdp);
1715 xdp.data_end = xdp.data + len;
1716 xdp.rxq = &tfile->xdp_rxq;
1718 act = bpf_prog_run_xdp(xdp_prog, &xdp);
1719 if (act == XDP_REDIRECT || act == XDP_TX) {
1720 get_page(alloc_frag->page);
1721 alloc_frag->offset += buflen;
1723 err = tun_xdp_act(tun, xdp_prog, &xdp, act);
1726 if (err == XDP_REDIRECT)
1728 if (err != XDP_PASS)
1731 pad = xdp.data - xdp.data_hard_start;
1732 len = xdp.data_end - xdp.data;
1737 return __tun_build_skb(alloc_frag, buf, buflen, len, pad);
1740 put_page(alloc_frag->page);
1747 /* Get packet from user space buffer */
1748 static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
1749 void *msg_control, struct iov_iter *from,
1750 int noblock, bool more)
1752 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
1753 struct sk_buff *skb;
1754 size_t total_len = iov_iter_count(from);
1755 size_t len = total_len, align = tun->align, linear;
1756 struct virtio_net_hdr gso = { 0 };
1757 struct tun_pcpu_stats *stats;
1760 bool zerocopy = false;
1764 bool frags = tun_napi_frags_enabled(tfile);
1766 if (!(tun->flags & IFF_NO_PI)) {
1767 if (len < sizeof(pi))
1771 if (!copy_from_iter_full(&pi, sizeof(pi), from))
1775 if (tun->flags & IFF_VNET_HDR) {
1776 int vnet_hdr_sz = READ_ONCE(tun->vnet_hdr_sz);
1778 if (len < vnet_hdr_sz)
1782 if (!copy_from_iter_full(&gso, sizeof(gso), from))
1785 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
1786 tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2 > tun16_to_cpu(tun, gso.hdr_len))
1787 gso.hdr_len = cpu_to_tun16(tun, tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2);
1789 if (tun16_to_cpu(tun, gso.hdr_len) > len)
1791 iov_iter_advance(from, vnet_hdr_sz - sizeof(gso));
1794 if ((tun->flags & TUN_TYPE_MASK) == IFF_TAP) {
1795 align += NET_IP_ALIGN;
1796 if (unlikely(len < ETH_HLEN ||
1797 (gso.hdr_len && tun16_to_cpu(tun, gso.hdr_len) < ETH_HLEN)))
1801 good_linear = SKB_MAX_HEAD(align);
1804 struct iov_iter i = *from;
1806 /* There are 256 bytes to be copied in skb, so there is
1807 * enough room for skb expand head in case it is used.
1808 * The rest of the buffer is mapped from userspace.
1810 copylen = gso.hdr_len ? tun16_to_cpu(tun, gso.hdr_len) : GOODCOPY_LEN;
1811 if (copylen > good_linear)
1812 copylen = good_linear;
1814 iov_iter_advance(&i, copylen);
1815 if (iov_iter_npages(&i, INT_MAX) <= MAX_SKB_FRAGS)
1819 if (!frags && tun_can_build_skb(tun, tfile, len, noblock, zerocopy)) {
1820 /* For the packet that is not easy to be processed
1821 * (e.g gso or jumbo packet), we will do it at after
1822 * skb was created with generic XDP routine.
1824 skb = tun_build_skb(tun, tfile, from, &gso, len, &skb_xdp);
1826 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1827 return PTR_ERR(skb);
1834 if (tun16_to_cpu(tun, gso.hdr_len) > good_linear)
1835 linear = good_linear;
1837 linear = tun16_to_cpu(tun, gso.hdr_len);
1841 mutex_lock(&tfile->napi_mutex);
1842 skb = tun_napi_alloc_frags(tfile, copylen, from);
1843 /* tun_napi_alloc_frags() enforces a layout for the skb.
1844 * If zerocopy is enabled, then this layout will be
1845 * overwritten by zerocopy_sg_from_iter().
1849 skb = tun_alloc_skb(tfile, align, copylen, linear,
1854 if (PTR_ERR(skb) != -EAGAIN)
1855 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1857 mutex_unlock(&tfile->napi_mutex);
1858 return PTR_ERR(skb);
1862 err = zerocopy_sg_from_iter(skb, from);
1864 err = skb_copy_datagram_from_iter(skb, 0, from, len);
1869 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1872 tfile->napi.skb = NULL;
1873 mutex_unlock(&tfile->napi_mutex);
1880 if (virtio_net_hdr_to_skb(skb, &gso, tun_is_little_endian(tun))) {
1881 this_cpu_inc(tun->pcpu_stats->rx_frame_errors);
1884 tfile->napi.skb = NULL;
1885 mutex_unlock(&tfile->napi_mutex);
1891 switch (tun->flags & TUN_TYPE_MASK) {
1893 if (tun->flags & IFF_NO_PI) {
1894 u8 ip_version = skb->len ? (skb->data[0] >> 4) : 0;
1896 switch (ip_version) {
1898 pi.proto = htons(ETH_P_IP);
1901 pi.proto = htons(ETH_P_IPV6);
1904 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1910 skb_reset_mac_header(skb);
1911 skb->protocol = pi.proto;
1912 skb->dev = tun->dev;
1916 skb->protocol = eth_type_trans(skb, tun->dev);
1920 /* copy skb_ubuf_info for callback when skb has no error */
1922 skb_shinfo(skb)->destructor_arg = msg_control;
1923 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
1924 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
1925 } else if (msg_control) {
1926 struct ubuf_info *uarg = msg_control;
1927 uarg->callback(uarg, false);
1930 skb_reset_network_header(skb);
1931 skb_probe_transport_header(skb);
1934 struct bpf_prog *xdp_prog;
1939 xdp_prog = rcu_dereference(tun->xdp_prog);
1941 ret = do_xdp_generic(xdp_prog, skb);
1942 if (ret != XDP_PASS) {
1952 /* Compute the costly rx hash only if needed for flow updates.
1953 * We may get a very small possibility of OOO during switching, not
1954 * worth to optimize.
1956 if (!rcu_access_pointer(tun->steering_prog) && tun->numqueues > 1 &&
1958 rxhash = __skb_get_hash_symmetric(skb);
1961 if (unlikely(!(tun->dev->flags & IFF_UP))) {
1968 /* Exercise flow dissector code path. */
1969 u32 headlen = eth_get_headlen(tun->dev, skb->data,
1972 if (unlikely(headlen > skb_headlen(skb))) {
1973 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1974 napi_free_frags(&tfile->napi);
1976 mutex_unlock(&tfile->napi_mutex);
1982 napi_gro_frags(&tfile->napi);
1984 mutex_unlock(&tfile->napi_mutex);
1985 } else if (tfile->napi_enabled) {
1986 struct sk_buff_head *queue = &tfile->sk.sk_write_queue;
1989 spin_lock_bh(&queue->lock);
1990 __skb_queue_tail(queue, skb);
1991 queue_len = skb_queue_len(queue);
1992 spin_unlock(&queue->lock);
1994 if (!more || queue_len > NAPI_POLL_WEIGHT)
1995 napi_schedule(&tfile->napi);
1998 } else if (!IS_ENABLED(CONFIG_4KSTACKS)) {
1999 tun_rx_batched(tun, tfile, skb, more);
2005 stats = get_cpu_ptr(tun->pcpu_stats);
2006 u64_stats_update_begin(&stats->syncp);
2007 stats->rx_packets++;
2008 stats->rx_bytes += len;
2009 u64_stats_update_end(&stats->syncp);
2013 tun_flow_update(tun, rxhash, tfile);
2018 static ssize_t tun_chr_write_iter(struct kiocb *iocb, struct iov_iter *from)
2020 struct file *file = iocb->ki_filp;
2021 struct tun_file *tfile = file->private_data;
2022 struct tun_struct *tun = tun_get(tfile);
2028 result = tun_get_user(tun, tfile, NULL, from,
2029 file->f_flags & O_NONBLOCK, false);
2035 static ssize_t tun_put_user_xdp(struct tun_struct *tun,
2036 struct tun_file *tfile,
2037 struct xdp_frame *xdp_frame,
2038 struct iov_iter *iter)
2040 int vnet_hdr_sz = 0;
2041 size_t size = xdp_frame->len;
2042 struct tun_pcpu_stats *stats;
2045 if (tun->flags & IFF_VNET_HDR) {
2046 struct virtio_net_hdr gso = { 0 };
2048 vnet_hdr_sz = READ_ONCE(tun->vnet_hdr_sz);
2049 if (unlikely(iov_iter_count(iter) < vnet_hdr_sz))
2051 if (unlikely(copy_to_iter(&gso, sizeof(gso), iter) !=
2054 iov_iter_advance(iter, vnet_hdr_sz - sizeof(gso));
2057 ret = copy_to_iter(xdp_frame->data, size, iter) + vnet_hdr_sz;
2059 stats = get_cpu_ptr(tun->pcpu_stats);
2060 u64_stats_update_begin(&stats->syncp);
2061 stats->tx_packets++;
2062 stats->tx_bytes += ret;
2063 u64_stats_update_end(&stats->syncp);
2064 put_cpu_ptr(tun->pcpu_stats);
2069 /* Put packet to the user space buffer */
2070 static ssize_t tun_put_user(struct tun_struct *tun,
2071 struct tun_file *tfile,
2072 struct sk_buff *skb,
2073 struct iov_iter *iter)
2075 struct tun_pi pi = { 0, skb->protocol };
2076 struct tun_pcpu_stats *stats;
2078 int vlan_offset = 0;
2080 int vnet_hdr_sz = 0;
2082 if (skb_vlan_tag_present(skb))
2083 vlan_hlen = VLAN_HLEN;
2085 if (tun->flags & IFF_VNET_HDR)
2086 vnet_hdr_sz = READ_ONCE(tun->vnet_hdr_sz);
2088 total = skb->len + vlan_hlen + vnet_hdr_sz;
2090 if (!(tun->flags & IFF_NO_PI)) {
2091 if (iov_iter_count(iter) < sizeof(pi))
2094 total += sizeof(pi);
2095 if (iov_iter_count(iter) < total) {
2096 /* Packet will be striped */
2097 pi.flags |= TUN_PKT_STRIP;
2100 if (copy_to_iter(&pi, sizeof(pi), iter) != sizeof(pi))
2105 struct virtio_net_hdr gso;
2107 if (iov_iter_count(iter) < vnet_hdr_sz)
2110 if (virtio_net_hdr_from_skb(skb, &gso,
2111 tun_is_little_endian(tun), true,
2113 struct skb_shared_info *sinfo = skb_shinfo(skb);
2114 pr_err("unexpected GSO type: "
2115 "0x%x, gso_size %d, hdr_len %d\n",
2116 sinfo->gso_type, tun16_to_cpu(tun, gso.gso_size),
2117 tun16_to_cpu(tun, gso.hdr_len));
2118 print_hex_dump(KERN_ERR, "tun: ",
2121 min((int)tun16_to_cpu(tun, gso.hdr_len), 64), true);
2126 if (copy_to_iter(&gso, sizeof(gso), iter) != sizeof(gso))
2129 iov_iter_advance(iter, vnet_hdr_sz - sizeof(gso));
2136 veth.h_vlan_proto = skb->vlan_proto;
2137 veth.h_vlan_TCI = htons(skb_vlan_tag_get(skb));
2139 vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto);
2141 ret = skb_copy_datagram_iter(skb, 0, iter, vlan_offset);
2142 if (ret || !iov_iter_count(iter))
2145 ret = copy_to_iter(&veth, sizeof(veth), iter);
2146 if (ret != sizeof(veth) || !iov_iter_count(iter))
2150 skb_copy_datagram_iter(skb, vlan_offset, iter, skb->len - vlan_offset);
2153 /* caller is in process context, */
2154 stats = get_cpu_ptr(tun->pcpu_stats);
2155 u64_stats_update_begin(&stats->syncp);
2156 stats->tx_packets++;
2157 stats->tx_bytes += skb->len + vlan_hlen;
2158 u64_stats_update_end(&stats->syncp);
2159 put_cpu_ptr(tun->pcpu_stats);
2164 static void *tun_ring_recv(struct tun_file *tfile, int noblock, int *err)
2166 DECLARE_WAITQUEUE(wait, current);
2170 ptr = ptr_ring_consume(&tfile->tx_ring);
2178 add_wait_queue(&tfile->wq.wait, &wait);
2181 set_current_state(TASK_INTERRUPTIBLE);
2182 ptr = ptr_ring_consume(&tfile->tx_ring);
2185 if (signal_pending(current)) {
2186 error = -ERESTARTSYS;
2189 if (tfile->socket.sk->sk_shutdown & RCV_SHUTDOWN) {
2197 __set_current_state(TASK_RUNNING);
2198 remove_wait_queue(&tfile->wq.wait, &wait);
2205 static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
2206 struct iov_iter *to,
2207 int noblock, void *ptr)
2212 tun_debug(KERN_INFO, tun, "tun_do_read\n");
2214 if (!iov_iter_count(to)) {
2220 /* Read frames from ring */
2221 ptr = tun_ring_recv(tfile, noblock, &err);
2226 if (tun_is_xdp_frame(ptr)) {
2227 struct xdp_frame *xdpf = tun_ptr_to_xdp(ptr);
2229 ret = tun_put_user_xdp(tun, tfile, xdpf, to);
2230 xdp_return_frame(xdpf);
2232 struct sk_buff *skb = ptr;
2234 ret = tun_put_user(tun, tfile, skb, to);
2235 if (unlikely(ret < 0))
2244 static ssize_t tun_chr_read_iter(struct kiocb *iocb, struct iov_iter *to)
2246 struct file *file = iocb->ki_filp;
2247 struct tun_file *tfile = file->private_data;
2248 struct tun_struct *tun = tun_get(tfile);
2249 ssize_t len = iov_iter_count(to), ret;
2253 ret = tun_do_read(tun, tfile, to, file->f_flags & O_NONBLOCK, NULL);
2254 ret = min_t(ssize_t, ret, len);
2261 static void tun_prog_free(struct rcu_head *rcu)
2263 struct tun_prog *prog = container_of(rcu, struct tun_prog, rcu);
2265 bpf_prog_destroy(prog->prog);
2269 static int __tun_set_ebpf(struct tun_struct *tun,
2270 struct tun_prog __rcu **prog_p,
2271 struct bpf_prog *prog)
2273 struct tun_prog *old, *new = NULL;
2276 new = kmalloc(sizeof(*new), GFP_KERNEL);
2282 spin_lock_bh(&tun->lock);
2283 old = rcu_dereference_protected(*prog_p,
2284 lockdep_is_held(&tun->lock));
2285 rcu_assign_pointer(*prog_p, new);
2286 spin_unlock_bh(&tun->lock);
2289 call_rcu(&old->rcu, tun_prog_free);
2294 static void tun_free_netdev(struct net_device *dev)
2296 struct tun_struct *tun = netdev_priv(dev);
2298 BUG_ON(!(list_empty(&tun->disabled)));
2299 free_percpu(tun->pcpu_stats);
2300 tun_flow_uninit(tun);
2301 security_tun_dev_free_security(tun->security);
2302 __tun_set_ebpf(tun, &tun->steering_prog, NULL);
2303 __tun_set_ebpf(tun, &tun->filter_prog, NULL);
2306 static void tun_setup(struct net_device *dev)
2308 struct tun_struct *tun = netdev_priv(dev);
2310 tun->owner = INVALID_UID;
2311 tun->group = INVALID_GID;
2312 tun_default_link_ksettings(dev, &tun->link_ksettings);
2314 dev->ethtool_ops = &tun_ethtool_ops;
2315 dev->needs_free_netdev = true;
2316 dev->priv_destructor = tun_free_netdev;
2317 /* We prefer our own queue length */
2318 dev->tx_queue_len = TUN_READQ_SIZE;
2321 /* Trivial set of netlink ops to allow deleting tun or tap
2322 * device with netlink.
2324 static int tun_validate(struct nlattr *tb[], struct nlattr *data[],
2325 struct netlink_ext_ack *extack)
2327 NL_SET_ERR_MSG(extack,
2328 "tun/tap creation via rtnetlink is not supported.");
2332 static size_t tun_get_size(const struct net_device *dev)
2334 BUILD_BUG_ON(sizeof(u32) != sizeof(uid_t));
2335 BUILD_BUG_ON(sizeof(u32) != sizeof(gid_t));
2337 return nla_total_size(sizeof(uid_t)) + /* OWNER */
2338 nla_total_size(sizeof(gid_t)) + /* GROUP */
2339 nla_total_size(sizeof(u8)) + /* TYPE */
2340 nla_total_size(sizeof(u8)) + /* PI */
2341 nla_total_size(sizeof(u8)) + /* VNET_HDR */
2342 nla_total_size(sizeof(u8)) + /* PERSIST */
2343 nla_total_size(sizeof(u8)) + /* MULTI_QUEUE */
2344 nla_total_size(sizeof(u32)) + /* NUM_QUEUES */
2345 nla_total_size(sizeof(u32)) + /* NUM_DISABLED_QUEUES */
2349 static int tun_fill_info(struct sk_buff *skb, const struct net_device *dev)
2351 struct tun_struct *tun = netdev_priv(dev);
2353 if (nla_put_u8(skb, IFLA_TUN_TYPE, tun->flags & TUN_TYPE_MASK))
2354 goto nla_put_failure;
2355 if (uid_valid(tun->owner) &&
2356 nla_put_u32(skb, IFLA_TUN_OWNER,
2357 from_kuid_munged(current_user_ns(), tun->owner)))
2358 goto nla_put_failure;
2359 if (gid_valid(tun->group) &&
2360 nla_put_u32(skb, IFLA_TUN_GROUP,
2361 from_kgid_munged(current_user_ns(), tun->group)))
2362 goto nla_put_failure;
2363 if (nla_put_u8(skb, IFLA_TUN_PI, !(tun->flags & IFF_NO_PI)))
2364 goto nla_put_failure;
2365 if (nla_put_u8(skb, IFLA_TUN_VNET_HDR, !!(tun->flags & IFF_VNET_HDR)))
2366 goto nla_put_failure;
2367 if (nla_put_u8(skb, IFLA_TUN_PERSIST, !!(tun->flags & IFF_PERSIST)))
2368 goto nla_put_failure;
2369 if (nla_put_u8(skb, IFLA_TUN_MULTI_QUEUE,
2370 !!(tun->flags & IFF_MULTI_QUEUE)))
2371 goto nla_put_failure;
2372 if (tun->flags & IFF_MULTI_QUEUE) {
2373 if (nla_put_u32(skb, IFLA_TUN_NUM_QUEUES, tun->numqueues))
2374 goto nla_put_failure;
2375 if (nla_put_u32(skb, IFLA_TUN_NUM_DISABLED_QUEUES,
2377 goto nla_put_failure;
2386 static struct rtnl_link_ops tun_link_ops __read_mostly = {
2388 .priv_size = sizeof(struct tun_struct),
2390 .validate = tun_validate,
2391 .get_size = tun_get_size,
2392 .fill_info = tun_fill_info,
2395 static void tun_sock_write_space(struct sock *sk)
2397 struct tun_file *tfile;
2398 wait_queue_head_t *wqueue;
2400 if (!sock_writeable(sk))
2403 if (!test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags))
2406 wqueue = sk_sleep(sk);
2407 if (wqueue && waitqueue_active(wqueue))
2408 wake_up_interruptible_sync_poll(wqueue, EPOLLOUT |
2409 EPOLLWRNORM | EPOLLWRBAND);
2411 tfile = container_of(sk, struct tun_file, sk);
2412 kill_fasync(&tfile->fasync, SIGIO, POLL_OUT);
2415 static void tun_put_page(struct tun_page *tpage)
2418 __page_frag_cache_drain(tpage->page, tpage->count);
2421 static int tun_xdp_one(struct tun_struct *tun,
2422 struct tun_file *tfile,
2423 struct xdp_buff *xdp, int *flush,
2424 struct tun_page *tpage)
2426 unsigned int datasize = xdp->data_end - xdp->data;
2427 struct tun_xdp_hdr *hdr = xdp->data_hard_start;
2428 struct virtio_net_hdr *gso = &hdr->gso;
2429 struct tun_pcpu_stats *stats;
2430 struct bpf_prog *xdp_prog;
2431 struct sk_buff *skb = NULL;
2432 u32 rxhash = 0, act;
2433 int buflen = hdr->buflen;
2435 bool skb_xdp = false;
2438 xdp_prog = rcu_dereference(tun->xdp_prog);
2440 if (gso->gso_type) {
2444 xdp_set_data_meta_invalid(xdp);
2445 xdp->rxq = &tfile->xdp_rxq;
2447 act = bpf_prog_run_xdp(xdp_prog, xdp);
2448 err = tun_xdp_act(tun, xdp_prog, xdp, act);
2450 put_page(virt_to_head_page(xdp->data));
2463 page = virt_to_head_page(xdp->data);
2464 if (tpage->page == page) {
2467 tun_put_page(tpage);
2476 skb = build_skb(xdp->data_hard_start, buflen);
2482 skb_reserve(skb, xdp->data - xdp->data_hard_start);
2483 skb_put(skb, xdp->data_end - xdp->data);
2485 if (virtio_net_hdr_to_skb(skb, gso, tun_is_little_endian(tun))) {
2486 this_cpu_inc(tun->pcpu_stats->rx_frame_errors);
2492 skb->protocol = eth_type_trans(skb, tun->dev);
2493 skb_reset_network_header(skb);
2494 skb_probe_transport_header(skb);
2497 err = do_xdp_generic(xdp_prog, skb);
2498 if (err != XDP_PASS)
2502 if (!rcu_dereference(tun->steering_prog) && tun->numqueues > 1 &&
2504 rxhash = __skb_get_hash_symmetric(skb);
2506 skb_record_rx_queue(skb, tfile->queue_index);
2507 netif_receive_skb(skb);
2509 /* No need for get_cpu_ptr() here since this function is
2510 * always called with bh disabled
2512 stats = this_cpu_ptr(tun->pcpu_stats);
2513 u64_stats_update_begin(&stats->syncp);
2514 stats->rx_packets++;
2515 stats->rx_bytes += datasize;
2516 u64_stats_update_end(&stats->syncp);
2519 tun_flow_update(tun, rxhash, tfile);
2525 static int tun_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
2528 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
2529 struct tun_struct *tun = tun_get(tfile);
2530 struct tun_msg_ctl *ctl = m->msg_control;
2531 struct xdp_buff *xdp;
2536 if (ctl && (ctl->type == TUN_MSG_PTR)) {
2537 struct tun_page tpage;
2541 memset(&tpage, 0, sizeof(tpage));
2546 for (i = 0; i < n; i++) {
2547 xdp = &((struct xdp_buff *)ctl->ptr)[i];
2548 tun_xdp_one(tun, tfile, xdp, &flush, &tpage);
2557 tun_put_page(&tpage);
2563 ret = tun_get_user(tun, tfile, ctl ? ctl->ptr : NULL, &m->msg_iter,
2564 m->msg_flags & MSG_DONTWAIT,
2565 m->msg_flags & MSG_MORE);
2571 static int tun_recvmsg(struct socket *sock, struct msghdr *m, size_t total_len,
2574 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
2575 struct tun_struct *tun = tun_get(tfile);
2576 void *ptr = m->msg_control;
2584 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC|MSG_ERRQUEUE)) {
2588 if (flags & MSG_ERRQUEUE) {
2589 ret = sock_recv_errqueue(sock->sk, m, total_len,
2590 SOL_PACKET, TUN_TX_TIMESTAMP);
2593 ret = tun_do_read(tun, tfile, &m->msg_iter, flags & MSG_DONTWAIT, ptr);
2594 if (ret > (ssize_t)total_len) {
2595 m->msg_flags |= MSG_TRUNC;
2596 ret = flags & MSG_TRUNC ? ret : total_len;
2609 static int tun_ptr_peek_len(void *ptr)
2612 if (tun_is_xdp_frame(ptr)) {
2613 struct xdp_frame *xdpf = tun_ptr_to_xdp(ptr);
2617 return __skb_array_len_with_tag(ptr);
2623 static int tun_peek_len(struct socket *sock)
2625 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
2626 struct tun_struct *tun;
2629 tun = tun_get(tfile);
2633 ret = PTR_RING_PEEK_CALL(&tfile->tx_ring, tun_ptr_peek_len);
2639 /* Ops structure to mimic raw sockets with tun */
2640 static const struct proto_ops tun_socket_ops = {
2641 .peek_len = tun_peek_len,
2642 .sendmsg = tun_sendmsg,
2643 .recvmsg = tun_recvmsg,
2646 static struct proto tun_proto = {
2648 .owner = THIS_MODULE,
2649 .obj_size = sizeof(struct tun_file),
2652 static int tun_flags(struct tun_struct *tun)
2654 return tun->flags & (TUN_FEATURES | IFF_PERSIST | IFF_TUN | IFF_TAP);
2657 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
2660 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
2661 return sprintf(buf, "0x%x\n", tun_flags(tun));
2664 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
2667 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
2668 return uid_valid(tun->owner)?
2669 sprintf(buf, "%u\n",
2670 from_kuid_munged(current_user_ns(), tun->owner)):
2671 sprintf(buf, "-1\n");
2674 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
2677 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
2678 return gid_valid(tun->group) ?
2679 sprintf(buf, "%u\n",
2680 from_kgid_munged(current_user_ns(), tun->group)):
2681 sprintf(buf, "-1\n");
2684 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
2685 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
2686 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
2688 static struct attribute *tun_dev_attrs[] = {
2689 &dev_attr_tun_flags.attr,
2690 &dev_attr_owner.attr,
2691 &dev_attr_group.attr,
2695 static const struct attribute_group tun_attr_group = {
2696 .attrs = tun_dev_attrs
2699 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
2701 struct tun_struct *tun;
2702 struct tun_file *tfile = file->private_data;
2703 struct net_device *dev;
2706 if (tfile->detached)
2709 if ((ifr->ifr_flags & IFF_NAPI_FRAGS)) {
2710 if (!capable(CAP_NET_ADMIN))
2713 if (!(ifr->ifr_flags & IFF_NAPI) ||
2714 (ifr->ifr_flags & TUN_TYPE_MASK) != IFF_TAP)
2718 dev = __dev_get_by_name(net, ifr->ifr_name);
2720 if (ifr->ifr_flags & IFF_TUN_EXCL)
2722 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
2723 tun = netdev_priv(dev);
2724 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
2725 tun = netdev_priv(dev);
2729 if (!!(ifr->ifr_flags & IFF_MULTI_QUEUE) !=
2730 !!(tun->flags & IFF_MULTI_QUEUE))
2733 if (tun_not_capable(tun))
2735 err = security_tun_dev_open(tun->security);
2739 err = tun_attach(tun, file, ifr->ifr_flags & IFF_NOFILTER,
2740 ifr->ifr_flags & IFF_NAPI,
2741 ifr->ifr_flags & IFF_NAPI_FRAGS);
2745 if (tun->flags & IFF_MULTI_QUEUE &&
2746 (tun->numqueues + tun->numdisabled > 1)) {
2747 /* One or more queue has already been attached, no need
2748 * to initialize the device again.
2750 netdev_state_change(dev);
2754 tun->flags = (tun->flags & ~TUN_FEATURES) |
2755 (ifr->ifr_flags & TUN_FEATURES);
2757 netdev_state_change(dev);
2760 unsigned long flags = 0;
2761 int queues = ifr->ifr_flags & IFF_MULTI_QUEUE ?
2764 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
2766 err = security_tun_dev_create();
2771 if (ifr->ifr_flags & IFF_TUN) {
2775 } else if (ifr->ifr_flags & IFF_TAP) {
2783 name = ifr->ifr_name;
2785 dev = alloc_netdev_mqs(sizeof(struct tun_struct), name,
2786 NET_NAME_UNKNOWN, tun_setup, queues,
2791 err = dev_get_valid_name(net, dev, name);
2795 dev_net_set(dev, net);
2796 dev->rtnl_link_ops = &tun_link_ops;
2797 dev->ifindex = tfile->ifindex;
2798 dev->sysfs_groups[0] = &tun_attr_group;
2800 tun = netdev_priv(dev);
2803 tun->txflt.count = 0;
2804 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
2806 tun->align = NET_SKB_PAD;
2807 tun->filter_attached = false;
2808 tun->sndbuf = tfile->socket.sk->sk_sndbuf;
2809 tun->rx_batched = 0;
2810 RCU_INIT_POINTER(tun->steering_prog, NULL);
2812 tun->pcpu_stats = netdev_alloc_pcpu_stats(struct tun_pcpu_stats);
2813 if (!tun->pcpu_stats) {
2818 spin_lock_init(&tun->lock);
2820 err = security_tun_dev_alloc_security(&tun->security);
2827 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
2828 TUN_USER_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
2829 NETIF_F_HW_VLAN_STAG_TX;
2830 dev->features = dev->hw_features | NETIF_F_LLTX;
2831 dev->vlan_features = dev->features &
2832 ~(NETIF_F_HW_VLAN_CTAG_TX |
2833 NETIF_F_HW_VLAN_STAG_TX);
2835 tun->flags = (tun->flags & ~TUN_FEATURES) |
2836 (ifr->ifr_flags & TUN_FEATURES);
2838 INIT_LIST_HEAD(&tun->disabled);
2839 err = tun_attach(tun, file, false, ifr->ifr_flags & IFF_NAPI,
2840 ifr->ifr_flags & IFF_NAPI_FRAGS);
2844 err = register_netdevice(tun->dev);
2849 netif_carrier_on(tun->dev);
2851 tun_debug(KERN_INFO, tun, "tun_set_iff\n");
2853 /* Make sure persistent devices do not get stuck in
2856 if (netif_running(tun->dev))
2857 netif_tx_wake_all_queues(tun->dev);
2859 strcpy(ifr->ifr_name, tun->dev->name);
2863 tun_detach_all(dev);
2864 /* register_netdevice() already called tun_free_netdev() */
2868 tun_flow_uninit(tun);
2869 security_tun_dev_free_security(tun->security);
2871 free_percpu(tun->pcpu_stats);
2877 static void tun_get_iff(struct tun_struct *tun, struct ifreq *ifr)
2879 tun_debug(KERN_INFO, tun, "tun_get_iff\n");
2881 strcpy(ifr->ifr_name, tun->dev->name);
2883 ifr->ifr_flags = tun_flags(tun);
2887 /* This is like a cut-down ethtool ops, except done via tun fd so no
2888 * privs required. */
2889 static int set_offload(struct tun_struct *tun, unsigned long arg)
2891 netdev_features_t features = 0;
2893 if (arg & TUN_F_CSUM) {
2894 features |= NETIF_F_HW_CSUM;
2897 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
2898 if (arg & TUN_F_TSO_ECN) {
2899 features |= NETIF_F_TSO_ECN;
2900 arg &= ~TUN_F_TSO_ECN;
2902 if (arg & TUN_F_TSO4)
2903 features |= NETIF_F_TSO;
2904 if (arg & TUN_F_TSO6)
2905 features |= NETIF_F_TSO6;
2906 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
2912 /* This gives the user a way to test for new features in future by
2913 * trying to set them. */
2917 tun->set_features = features;
2918 tun->dev->wanted_features &= ~TUN_USER_FEATURES;
2919 tun->dev->wanted_features |= features;
2920 netdev_update_features(tun->dev);
2925 static void tun_detach_filter(struct tun_struct *tun, int n)
2928 struct tun_file *tfile;
2930 for (i = 0; i < n; i++) {
2931 tfile = rtnl_dereference(tun->tfiles[i]);
2932 lock_sock(tfile->socket.sk);
2933 sk_detach_filter(tfile->socket.sk);
2934 release_sock(tfile->socket.sk);
2937 tun->filter_attached = false;
2940 static int tun_attach_filter(struct tun_struct *tun)
2943 struct tun_file *tfile;
2945 for (i = 0; i < tun->numqueues; i++) {
2946 tfile = rtnl_dereference(tun->tfiles[i]);
2947 lock_sock(tfile->socket.sk);
2948 ret = sk_attach_filter(&tun->fprog, tfile->socket.sk);
2949 release_sock(tfile->socket.sk);
2951 tun_detach_filter(tun, i);
2956 tun->filter_attached = true;
2960 static void tun_set_sndbuf(struct tun_struct *tun)
2962 struct tun_file *tfile;
2965 for (i = 0; i < tun->numqueues; i++) {
2966 tfile = rtnl_dereference(tun->tfiles[i]);
2967 tfile->socket.sk->sk_sndbuf = tun->sndbuf;
2971 static int tun_set_queue(struct file *file, struct ifreq *ifr)
2973 struct tun_file *tfile = file->private_data;
2974 struct tun_struct *tun;
2979 if (ifr->ifr_flags & IFF_ATTACH_QUEUE) {
2980 tun = tfile->detached;
2985 ret = security_tun_dev_attach_queue(tun->security);
2988 ret = tun_attach(tun, file, false, tun->flags & IFF_NAPI,
2989 tun->flags & IFF_NAPI_FRAGS);
2990 } else if (ifr->ifr_flags & IFF_DETACH_QUEUE) {
2991 tun = rtnl_dereference(tfile->tun);
2992 if (!tun || !(tun->flags & IFF_MULTI_QUEUE) || tfile->detached)
2995 __tun_detach(tfile, false);
3000 netdev_state_change(tun->dev);
3007 static int tun_set_ebpf(struct tun_struct *tun, struct tun_prog **prog_p,
3010 struct bpf_prog *prog;
3013 if (copy_from_user(&fd, data, sizeof(fd)))
3019 prog = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER);
3021 return PTR_ERR(prog);
3024 return __tun_set_ebpf(tun, prog_p, prog);
3027 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
3028 unsigned long arg, int ifreq_len)
3030 struct tun_file *tfile = file->private_data;
3031 struct net *net = sock_net(&tfile->sk);
3032 struct tun_struct *tun;
3033 void __user* argp = (void __user*)arg;
3034 unsigned int ifindex, carrier;
3042 bool do_notify = false;
3044 if (cmd == TUNSETIFF || cmd == TUNSETQUEUE ||
3045 (_IOC_TYPE(cmd) == SOCK_IOC_TYPE && cmd != SIOCGSKNS)) {
3046 if (copy_from_user(&ifr, argp, ifreq_len))
3049 memset(&ifr, 0, sizeof(ifr));
3051 if (cmd == TUNGETFEATURES) {
3052 /* Currently this just means: "what IFF flags are valid?".
3053 * This is needed because we never checked for invalid flags on
3056 return put_user(IFF_TUN | IFF_TAP | TUN_FEATURES,
3057 (unsigned int __user*)argp);
3058 } else if (cmd == TUNSETQUEUE) {
3059 return tun_set_queue(file, &ifr);
3060 } else if (cmd == SIOCGSKNS) {
3061 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
3063 return open_related_ns(&net->ns, get_net_ns);
3069 tun = tun_get(tfile);
3070 if (cmd == TUNSETIFF) {
3075 ifr.ifr_name[IFNAMSIZ-1] = '\0';
3077 ret = tun_set_iff(net, file, &ifr);
3082 if (copy_to_user(argp, &ifr, ifreq_len))
3086 if (cmd == TUNSETIFINDEX) {
3092 if (copy_from_user(&ifindex, argp, sizeof(ifindex)))
3096 tfile->ifindex = ifindex;
3104 tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %u\n", cmd);
3106 net = dev_net(tun->dev);
3110 tun_get_iff(tun, &ifr);
3112 if (tfile->detached)
3113 ifr.ifr_flags |= IFF_DETACH_QUEUE;
3114 if (!tfile->socket.sk->sk_filter)
3115 ifr.ifr_flags |= IFF_NOFILTER;
3117 if (copy_to_user(argp, &ifr, ifreq_len))
3122 /* Disable/Enable checksum */
3124 /* [unimplemented] */
3125 tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n",
3126 arg ? "disabled" : "enabled");
3130 /* Disable/Enable persist mode. Keep an extra reference to the
3131 * module to prevent the module being unprobed.
3133 if (arg && !(tun->flags & IFF_PERSIST)) {
3134 tun->flags |= IFF_PERSIST;
3135 __module_get(THIS_MODULE);
3138 if (!arg && (tun->flags & IFF_PERSIST)) {
3139 tun->flags &= ~IFF_PERSIST;
3140 module_put(THIS_MODULE);
3144 tun_debug(KERN_INFO, tun, "persist %s\n",
3145 arg ? "enabled" : "disabled");
3149 /* Set owner of the device */
3150 owner = make_kuid(current_user_ns(), arg);
3151 if (!uid_valid(owner)) {
3157 tun_debug(KERN_INFO, tun, "owner set to %u\n",
3158 from_kuid(&init_user_ns, tun->owner));
3162 /* Set group of the device */
3163 group = make_kgid(current_user_ns(), arg);
3164 if (!gid_valid(group)) {
3170 tun_debug(KERN_INFO, tun, "group set to %u\n",
3171 from_kgid(&init_user_ns, tun->group));
3175 /* Only allow setting the type when the interface is down */
3176 if (tun->dev->flags & IFF_UP) {
3177 tun_debug(KERN_INFO, tun,
3178 "Linktype set failed because interface is up\n");
3181 tun->dev->type = (int) arg;
3182 tun_debug(KERN_INFO, tun, "linktype set to %d\n",
3194 ret = set_offload(tun, arg);
3197 case TUNSETTXFILTER:
3198 /* Can be set only for TAPs */
3200 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
3202 ret = update_filter(&tun->txflt, (void __user *)arg);
3206 /* Get hw address */
3207 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
3208 ifr.ifr_hwaddr.sa_family = tun->dev->type;
3209 if (copy_to_user(argp, &ifr, ifreq_len))
3214 /* Set hw address */
3215 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n",
3216 ifr.ifr_hwaddr.sa_data);
3218 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr, NULL);
3222 sndbuf = tfile->socket.sk->sk_sndbuf;
3223 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
3228 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
3237 tun->sndbuf = sndbuf;
3238 tun_set_sndbuf(tun);
3241 case TUNGETVNETHDRSZ:
3242 vnet_hdr_sz = tun->vnet_hdr_sz;
3243 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
3247 case TUNSETVNETHDRSZ:
3248 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
3252 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
3257 tun->vnet_hdr_sz = vnet_hdr_sz;
3261 le = !!(tun->flags & TUN_VNET_LE);
3262 if (put_user(le, (int __user *)argp))
3267 if (get_user(le, (int __user *)argp)) {
3272 tun->flags |= TUN_VNET_LE;
3274 tun->flags &= ~TUN_VNET_LE;
3278 ret = tun_get_vnet_be(tun, argp);
3282 ret = tun_set_vnet_be(tun, argp);
3285 case TUNATTACHFILTER:
3286 /* Can be set only for TAPs */
3288 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
3291 if (copy_from_user(&tun->fprog, argp, sizeof(tun->fprog)))
3294 ret = tun_attach_filter(tun);
3297 case TUNDETACHFILTER:
3298 /* Can be set only for TAPs */
3300 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
3303 tun_detach_filter(tun, tun->numqueues);
3308 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
3311 if (copy_to_user(argp, &tun->fprog, sizeof(tun->fprog)))
3316 case TUNSETSTEERINGEBPF:
3317 ret = tun_set_ebpf(tun, &tun->steering_prog, argp);
3320 case TUNSETFILTEREBPF:
3321 ret = tun_set_ebpf(tun, &tun->filter_prog, argp);
3326 if (copy_from_user(&carrier, argp, sizeof(carrier)))
3329 ret = tun_net_change_carrier(tun->dev, (bool)carrier);
3332 case TUNGETDEVNETNS:
3334 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
3336 ret = open_related_ns(&net->ns, get_net_ns);
3345 netdev_state_change(tun->dev);
3354 static long tun_chr_ioctl(struct file *file,
3355 unsigned int cmd, unsigned long arg)
3357 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
3360 #ifdef CONFIG_COMPAT
3361 static long tun_chr_compat_ioctl(struct file *file,
3362 unsigned int cmd, unsigned long arg)
3367 case TUNSETTXFILTER:
3372 arg = (unsigned long)compat_ptr(arg);
3375 arg = (compat_ulong_t)arg;
3380 * compat_ifreq is shorter than ifreq, so we must not access beyond
3381 * the end of that structure. All fields that are used in this
3382 * driver are compatible though, we don't need to convert the
3385 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
3387 #endif /* CONFIG_COMPAT */
3389 static int tun_chr_fasync(int fd, struct file *file, int on)
3391 struct tun_file *tfile = file->private_data;
3394 if ((ret = fasync_helper(fd, file, on, &tfile->fasync)) < 0)
3398 __f_setown(file, task_pid(current), PIDTYPE_TGID, 0);
3399 tfile->flags |= TUN_FASYNC;
3401 tfile->flags &= ~TUN_FASYNC;
3407 static int tun_chr_open(struct inode *inode, struct file * file)
3409 struct net *net = current->nsproxy->net_ns;
3410 struct tun_file *tfile;
3412 DBG1(KERN_INFO, "tunX: tun_chr_open\n");
3414 tfile = (struct tun_file *)sk_alloc(net, AF_UNSPEC, GFP_KERNEL,
3418 if (ptr_ring_init(&tfile->tx_ring, 0, GFP_KERNEL)) {
3419 sk_free(&tfile->sk);
3423 mutex_init(&tfile->napi_mutex);
3424 RCU_INIT_POINTER(tfile->tun, NULL);
3428 init_waitqueue_head(&tfile->wq.wait);
3429 RCU_INIT_POINTER(tfile->socket.wq, &tfile->wq);
3431 tfile->socket.file = file;
3432 tfile->socket.ops = &tun_socket_ops;
3434 sock_init_data(&tfile->socket, &tfile->sk);
3436 tfile->sk.sk_write_space = tun_sock_write_space;
3437 tfile->sk.sk_sndbuf = INT_MAX;
3439 file->private_data = tfile;
3440 INIT_LIST_HEAD(&tfile->next);
3442 sock_set_flag(&tfile->sk, SOCK_ZEROCOPY);
3447 static int tun_chr_close(struct inode *inode, struct file *file)
3449 struct tun_file *tfile = file->private_data;
3451 tun_detach(tfile, true);
3456 #ifdef CONFIG_PROC_FS
3457 static void tun_chr_show_fdinfo(struct seq_file *m, struct file *file)
3459 struct tun_file *tfile = file->private_data;
3460 struct tun_struct *tun;
3463 memset(&ifr, 0, sizeof(ifr));
3466 tun = tun_get(tfile);
3468 tun_get_iff(tun, &ifr);
3474 seq_printf(m, "iff:\t%s\n", ifr.ifr_name);
3478 static const struct file_operations tun_fops = {
3479 .owner = THIS_MODULE,
3480 .llseek = no_llseek,
3481 .read_iter = tun_chr_read_iter,
3482 .write_iter = tun_chr_write_iter,
3483 .poll = tun_chr_poll,
3484 .unlocked_ioctl = tun_chr_ioctl,
3485 #ifdef CONFIG_COMPAT
3486 .compat_ioctl = tun_chr_compat_ioctl,
3488 .open = tun_chr_open,
3489 .release = tun_chr_close,
3490 .fasync = tun_chr_fasync,
3491 #ifdef CONFIG_PROC_FS
3492 .show_fdinfo = tun_chr_show_fdinfo,
3496 static struct miscdevice tun_miscdev = {
3499 .nodename = "net/tun",
3503 /* ethtool interface */
3505 static void tun_default_link_ksettings(struct net_device *dev,
3506 struct ethtool_link_ksettings *cmd)
3508 ethtool_link_ksettings_zero_link_mode(cmd, supported);
3509 ethtool_link_ksettings_zero_link_mode(cmd, advertising);
3510 cmd->base.speed = SPEED_10;
3511 cmd->base.duplex = DUPLEX_FULL;
3512 cmd->base.port = PORT_TP;
3513 cmd->base.phy_address = 0;
3514 cmd->base.autoneg = AUTONEG_DISABLE;
3517 static int tun_get_link_ksettings(struct net_device *dev,
3518 struct ethtool_link_ksettings *cmd)
3520 struct tun_struct *tun = netdev_priv(dev);
3522 memcpy(cmd, &tun->link_ksettings, sizeof(*cmd));
3526 static int tun_set_link_ksettings(struct net_device *dev,
3527 const struct ethtool_link_ksettings *cmd)
3529 struct tun_struct *tun = netdev_priv(dev);
3531 memcpy(&tun->link_ksettings, cmd, sizeof(*cmd));
3535 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
3537 struct tun_struct *tun = netdev_priv(dev);
3539 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
3540 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
3542 switch (tun->flags & TUN_TYPE_MASK) {
3544 strlcpy(info->bus_info, "tun", sizeof(info->bus_info));
3547 strlcpy(info->bus_info, "tap", sizeof(info->bus_info));
3552 static u32 tun_get_msglevel(struct net_device *dev)
3555 struct tun_struct *tun = netdev_priv(dev);
3562 static void tun_set_msglevel(struct net_device *dev, u32 value)
3565 struct tun_struct *tun = netdev_priv(dev);
3570 static int tun_get_coalesce(struct net_device *dev,
3571 struct ethtool_coalesce *ec)
3573 struct tun_struct *tun = netdev_priv(dev);
3575 ec->rx_max_coalesced_frames = tun->rx_batched;
3580 static int tun_set_coalesce(struct net_device *dev,
3581 struct ethtool_coalesce *ec)
3583 struct tun_struct *tun = netdev_priv(dev);
3585 if (ec->rx_max_coalesced_frames > NAPI_POLL_WEIGHT)
3586 tun->rx_batched = NAPI_POLL_WEIGHT;
3588 tun->rx_batched = ec->rx_max_coalesced_frames;
3593 static const struct ethtool_ops tun_ethtool_ops = {
3594 .get_drvinfo = tun_get_drvinfo,
3595 .get_msglevel = tun_get_msglevel,
3596 .set_msglevel = tun_set_msglevel,
3597 .get_link = ethtool_op_get_link,
3598 .get_ts_info = ethtool_op_get_ts_info,
3599 .get_coalesce = tun_get_coalesce,
3600 .set_coalesce = tun_set_coalesce,
3601 .get_link_ksettings = tun_get_link_ksettings,
3602 .set_link_ksettings = tun_set_link_ksettings,
3605 static int tun_queue_resize(struct tun_struct *tun)
3607 struct net_device *dev = tun->dev;
3608 struct tun_file *tfile;
3609 struct ptr_ring **rings;
3610 int n = tun->numqueues + tun->numdisabled;
3613 rings = kmalloc_array(n, sizeof(*rings), GFP_KERNEL);
3617 for (i = 0; i < tun->numqueues; i++) {
3618 tfile = rtnl_dereference(tun->tfiles[i]);
3619 rings[i] = &tfile->tx_ring;
3621 list_for_each_entry(tfile, &tun->disabled, next)
3622 rings[i++] = &tfile->tx_ring;
3624 ret = ptr_ring_resize_multiple(rings, n,
3625 dev->tx_queue_len, GFP_KERNEL,
3632 static int tun_device_event(struct notifier_block *unused,
3633 unsigned long event, void *ptr)
3635 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3636 struct tun_struct *tun = netdev_priv(dev);
3638 if (dev->rtnl_link_ops != &tun_link_ops)
3642 case NETDEV_CHANGE_TX_QUEUE_LEN:
3643 if (tun_queue_resize(tun))
3653 static struct notifier_block tun_notifier_block __read_mostly = {
3654 .notifier_call = tun_device_event,
3657 static int __init tun_init(void)
3661 pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
3663 ret = rtnl_link_register(&tun_link_ops);
3665 pr_err("Can't register link_ops\n");
3669 ret = misc_register(&tun_miscdev);
3671 pr_err("Can't register misc device %d\n", TUN_MINOR);
3675 ret = register_netdevice_notifier(&tun_notifier_block);
3677 pr_err("Can't register netdevice notifier\n");
3684 misc_deregister(&tun_miscdev);
3686 rtnl_link_unregister(&tun_link_ops);
3691 static void tun_cleanup(void)
3693 misc_deregister(&tun_miscdev);
3694 rtnl_link_unregister(&tun_link_ops);
3695 unregister_netdevice_notifier(&tun_notifier_block);
3698 /* Get an underlying socket object from tun file. Returns error unless file is
3699 * attached to a device. The returned object works like a packet socket, it
3700 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
3701 * holding a reference to the file for as long as the socket is in use. */
3702 struct socket *tun_get_socket(struct file *file)
3704 struct tun_file *tfile;
3705 if (file->f_op != &tun_fops)
3706 return ERR_PTR(-EINVAL);
3707 tfile = file->private_data;
3709 return ERR_PTR(-EBADFD);
3710 return &tfile->socket;
3712 EXPORT_SYMBOL_GPL(tun_get_socket);
3714 struct ptr_ring *tun_get_tx_ring(struct file *file)
3716 struct tun_file *tfile;
3718 if (file->f_op != &tun_fops)
3719 return ERR_PTR(-EINVAL);
3720 tfile = file->private_data;
3722 return ERR_PTR(-EBADFD);
3723 return &tfile->tx_ring;
3725 EXPORT_SYMBOL_GPL(tun_get_tx_ring);
3727 module_init(tun_init);
3728 module_exit(tun_cleanup);
3729 MODULE_DESCRIPTION(DRV_DESCRIPTION);
3730 MODULE_AUTHOR(DRV_COPYRIGHT);
3731 MODULE_LICENSE("GPL");
3732 MODULE_ALIAS_MISCDEV(TUN_MINOR);
3733 MODULE_ALIAS("devname:net/tun");