1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * TUN - Universal TUN/TAP device driver.
4 * Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com>
6 * $Id: tun.c,v 1.15 2002/03/01 02:44:24 maxk Exp $
12 * Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14
13 * Add TUNSETLINK ioctl to set the link encapsulation
15 * Mark Smith <markzzzsmith@yahoo.com.au>
16 * Use eth_random_addr() for tap MAC address.
18 * Harald Roelle <harald.roelle@ifi.lmu.de> 2004/04/20
19 * Fixes in packet dropping, queue length setting and queue wakeup.
20 * Increased default tx queue length.
24 * Daniel Podlejski <underley@underley.eu.org>
25 * Modifications for 2.3.99-pre5 kernel.
28 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
30 #define DRV_NAME "tun"
31 #define DRV_VERSION "1.6"
32 #define DRV_DESCRIPTION "Universal TUN/TAP device driver"
33 #define DRV_COPYRIGHT "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>"
35 #include <linux/module.h>
36 #include <linux/errno.h>
37 #include <linux/kernel.h>
38 #include <linux/sched/signal.h>
39 #include <linux/major.h>
40 #include <linux/slab.h>
41 #include <linux/poll.h>
42 #include <linux/fcntl.h>
43 #include <linux/init.h>
44 #include <linux/skbuff.h>
45 #include <linux/netdevice.h>
46 #include <linux/etherdevice.h>
47 #include <linux/miscdevice.h>
48 #include <linux/ethtool.h>
49 #include <linux/rtnetlink.h>
50 #include <linux/compat.h>
52 #include <linux/if_arp.h>
53 #include <linux/if_ether.h>
54 #include <linux/if_tun.h>
55 #include <linux/if_vlan.h>
56 #include <linux/crc32.h>
57 #include <linux/nsproxy.h>
58 #include <linux/virtio_net.h>
59 #include <linux/rcupdate.h>
60 #include <net/net_namespace.h>
61 #include <net/netns/generic.h>
62 #include <net/rtnetlink.h>
65 #include <net/ip_tunnels.h>
66 #include <linux/seq_file.h>
67 #include <linux/uio.h>
68 #include <linux/skb_array.h>
69 #include <linux/bpf.h>
70 #include <linux/bpf_trace.h>
71 #include <linux/mutex.h>
73 #include <linux/uaccess.h>
74 #include <linux/proc_fs.h>
76 static void tun_default_link_ksettings(struct net_device *dev,
77 struct ethtool_link_ksettings *cmd);
79 #define TUN_RX_PAD (NET_IP_ALIGN + NET_SKB_PAD)
81 /* TUN device flags */
83 /* IFF_ATTACH_QUEUE is never stored in device flags,
84 * overload it to mean fasync when stored there.
86 #define TUN_FASYNC IFF_ATTACH_QUEUE
87 /* High bits in flags field are unused. */
88 #define TUN_VNET_LE 0x80000000
89 #define TUN_VNET_BE 0x40000000
91 #define TUN_FEATURES (IFF_NO_PI | IFF_ONE_QUEUE | IFF_VNET_HDR | \
92 IFF_MULTI_QUEUE | IFF_NAPI | IFF_NAPI_FRAGS)
94 #define GOODCOPY_LEN 128
96 #define FLT_EXACT_COUNT 8
98 unsigned int count; /* Number of addrs. Zero means disabled */
99 u32 mask[2]; /* Mask of the hashed addrs */
100 unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN];
103 /* MAX_TAP_QUEUES 256 is chosen to allow rx/tx queues to be equal
104 * to max number of VCPUs in guest. */
105 #define MAX_TAP_QUEUES 256
106 #define MAX_TAP_FLOWS 4096
108 #define TUN_FLOW_EXPIRE (3 * HZ)
110 struct tun_pcpu_stats {
111 u64_stats_t rx_packets;
112 u64_stats_t rx_bytes;
113 u64_stats_t tx_packets;
114 u64_stats_t tx_bytes;
115 struct u64_stats_sync syncp;
121 /* A tun_file connects an open character device to a tuntap netdevice. It
122 * also contains all socket related structures (except sock_fprog and tap_filter)
123 * to serve as one transmit queue for tuntap device. The sock_fprog and
124 * tap_filter were kept in tun_struct since they were used for filtering for the
125 * netdevice not for a specific queue (at least I didn't see the requirement for
129 * The tun_file and tun_struct are loosely coupled, the pointer from one to the
130 * other can only be read while rcu_read_lock or rtnl_lock is held.
134 struct socket socket;
135 struct tun_struct __rcu *tun;
136 struct fasync_struct *fasync;
137 /* only used for fasnyc */
141 unsigned int ifindex;
143 struct napi_struct napi;
145 bool napi_frags_enabled;
146 struct mutex napi_mutex; /* Protects access to the above napi */
147 struct list_head next;
148 struct tun_struct *detached;
149 struct ptr_ring tx_ring;
150 struct xdp_rxq_info xdp_rxq;
158 struct tun_flow_entry {
159 struct hlist_node hash_link;
161 struct tun_struct *tun;
166 unsigned long updated ____cacheline_aligned_in_smp;
169 #define TUN_NUM_FLOW_ENTRIES 1024
170 #define TUN_MASK_FLOW_ENTRIES (TUN_NUM_FLOW_ENTRIES - 1)
174 struct bpf_prog *prog;
177 /* Since the socket were moved to tun_file, to preserve the behavior of persist
178 * device, socket filter, sndbuf and vnet header size were restore when the
179 * file were attached to a persist device.
182 struct tun_file __rcu *tfiles[MAX_TAP_QUEUES];
183 unsigned int numqueues;
188 struct net_device *dev;
189 netdev_features_t set_features;
190 #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \
196 struct tap_filter txflt;
197 struct sock_fprog fprog;
198 /* protected by rtnl lock */
199 bool filter_attached;
202 struct hlist_head flows[TUN_NUM_FLOW_ENTRIES];
203 struct timer_list flow_gc_timer;
204 unsigned long ageing_time;
205 unsigned int numdisabled;
206 struct list_head disabled;
210 struct tun_pcpu_stats __percpu *pcpu_stats;
211 struct bpf_prog __rcu *xdp_prog;
212 struct tun_prog __rcu *steering_prog;
213 struct tun_prog __rcu *filter_prog;
214 struct ethtool_link_ksettings link_ksettings;
222 static int tun_napi_receive(struct napi_struct *napi, int budget)
224 struct tun_file *tfile = container_of(napi, struct tun_file, napi);
225 struct sk_buff_head *queue = &tfile->sk.sk_write_queue;
226 struct sk_buff_head process_queue;
230 __skb_queue_head_init(&process_queue);
232 spin_lock(&queue->lock);
233 skb_queue_splice_tail_init(queue, &process_queue);
234 spin_unlock(&queue->lock);
236 while (received < budget && (skb = __skb_dequeue(&process_queue))) {
237 napi_gro_receive(napi, skb);
241 if (!skb_queue_empty(&process_queue)) {
242 spin_lock(&queue->lock);
243 skb_queue_splice(&process_queue, queue);
244 spin_unlock(&queue->lock);
250 static int tun_napi_poll(struct napi_struct *napi, int budget)
252 unsigned int received;
254 received = tun_napi_receive(napi, budget);
256 if (received < budget)
257 napi_complete_done(napi, received);
262 static void tun_napi_init(struct tun_struct *tun, struct tun_file *tfile,
263 bool napi_en, bool napi_frags)
265 tfile->napi_enabled = napi_en;
266 tfile->napi_frags_enabled = napi_en && napi_frags;
268 netif_tx_napi_add(tun->dev, &tfile->napi, tun_napi_poll,
270 napi_enable(&tfile->napi);
274 static void tun_napi_disable(struct tun_file *tfile)
276 if (tfile->napi_enabled)
277 napi_disable(&tfile->napi);
280 static void tun_napi_del(struct tun_file *tfile)
282 if (tfile->napi_enabled)
283 netif_napi_del(&tfile->napi);
286 static bool tun_napi_frags_enabled(const struct tun_file *tfile)
288 return tfile->napi_frags_enabled;
291 #ifdef CONFIG_TUN_VNET_CROSS_LE
292 static inline bool tun_legacy_is_little_endian(struct tun_struct *tun)
294 return tun->flags & TUN_VNET_BE ? false :
295 virtio_legacy_is_little_endian();
298 static long tun_get_vnet_be(struct tun_struct *tun, int __user *argp)
300 int be = !!(tun->flags & TUN_VNET_BE);
302 if (put_user(be, argp))
308 static long tun_set_vnet_be(struct tun_struct *tun, int __user *argp)
312 if (get_user(be, argp))
316 tun->flags |= TUN_VNET_BE;
318 tun->flags &= ~TUN_VNET_BE;
323 static inline bool tun_legacy_is_little_endian(struct tun_struct *tun)
325 return virtio_legacy_is_little_endian();
328 static long tun_get_vnet_be(struct tun_struct *tun, int __user *argp)
333 static long tun_set_vnet_be(struct tun_struct *tun, int __user *argp)
337 #endif /* CONFIG_TUN_VNET_CROSS_LE */
339 static inline bool tun_is_little_endian(struct tun_struct *tun)
341 return tun->flags & TUN_VNET_LE ||
342 tun_legacy_is_little_endian(tun);
345 static inline u16 tun16_to_cpu(struct tun_struct *tun, __virtio16 val)
347 return __virtio16_to_cpu(tun_is_little_endian(tun), val);
350 static inline __virtio16 cpu_to_tun16(struct tun_struct *tun, u16 val)
352 return __cpu_to_virtio16(tun_is_little_endian(tun), val);
355 static inline u32 tun_hashfn(u32 rxhash)
357 return rxhash & TUN_MASK_FLOW_ENTRIES;
360 static struct tun_flow_entry *tun_flow_find(struct hlist_head *head, u32 rxhash)
362 struct tun_flow_entry *e;
364 hlist_for_each_entry_rcu(e, head, hash_link) {
365 if (e->rxhash == rxhash)
371 static struct tun_flow_entry *tun_flow_create(struct tun_struct *tun,
372 struct hlist_head *head,
373 u32 rxhash, u16 queue_index)
375 struct tun_flow_entry *e = kmalloc(sizeof(*e), GFP_ATOMIC);
378 netif_info(tun, tx_queued, tun->dev,
379 "create flow: hash %u index %u\n",
380 rxhash, queue_index);
381 e->updated = jiffies;
384 e->queue_index = queue_index;
386 hlist_add_head_rcu(&e->hash_link, head);
392 static void tun_flow_delete(struct tun_struct *tun, struct tun_flow_entry *e)
394 netif_info(tun, tx_queued, tun->dev, "delete flow: hash %u index %u\n",
395 e->rxhash, e->queue_index);
396 hlist_del_rcu(&e->hash_link);
401 static void tun_flow_flush(struct tun_struct *tun)
405 spin_lock_bh(&tun->lock);
406 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
407 struct tun_flow_entry *e;
408 struct hlist_node *n;
410 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link)
411 tun_flow_delete(tun, e);
413 spin_unlock_bh(&tun->lock);
416 static void tun_flow_delete_by_queue(struct tun_struct *tun, u16 queue_index)
420 spin_lock_bh(&tun->lock);
421 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
422 struct tun_flow_entry *e;
423 struct hlist_node *n;
425 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
426 if (e->queue_index == queue_index)
427 tun_flow_delete(tun, e);
430 spin_unlock_bh(&tun->lock);
433 static void tun_flow_cleanup(struct timer_list *t)
435 struct tun_struct *tun = from_timer(tun, t, flow_gc_timer);
436 unsigned long delay = tun->ageing_time;
437 unsigned long next_timer = jiffies + delay;
438 unsigned long count = 0;
441 spin_lock(&tun->lock);
442 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
443 struct tun_flow_entry *e;
444 struct hlist_node *n;
446 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
447 unsigned long this_timer;
449 this_timer = e->updated + delay;
450 if (time_before_eq(this_timer, jiffies)) {
451 tun_flow_delete(tun, e);
455 if (time_before(this_timer, next_timer))
456 next_timer = this_timer;
461 mod_timer(&tun->flow_gc_timer, round_jiffies_up(next_timer));
462 spin_unlock(&tun->lock);
465 static void tun_flow_update(struct tun_struct *tun, u32 rxhash,
466 struct tun_file *tfile)
468 struct hlist_head *head;
469 struct tun_flow_entry *e;
470 unsigned long delay = tun->ageing_time;
471 u16 queue_index = tfile->queue_index;
473 head = &tun->flows[tun_hashfn(rxhash)];
477 e = tun_flow_find(head, rxhash);
479 /* TODO: keep queueing to old queue until it's empty? */
480 if (READ_ONCE(e->queue_index) != queue_index)
481 WRITE_ONCE(e->queue_index, queue_index);
482 if (e->updated != jiffies)
483 e->updated = jiffies;
484 sock_rps_record_flow_hash(e->rps_rxhash);
486 spin_lock_bh(&tun->lock);
487 if (!tun_flow_find(head, rxhash) &&
488 tun->flow_count < MAX_TAP_FLOWS)
489 tun_flow_create(tun, head, rxhash, queue_index);
491 if (!timer_pending(&tun->flow_gc_timer))
492 mod_timer(&tun->flow_gc_timer,
493 round_jiffies_up(jiffies + delay));
494 spin_unlock_bh(&tun->lock);
500 /* Save the hash received in the stack receive path and update the
501 * flow_hash table accordingly.
503 static inline void tun_flow_save_rps_rxhash(struct tun_flow_entry *e, u32 hash)
505 if (unlikely(e->rps_rxhash != hash))
506 e->rps_rxhash = hash;
509 /* We try to identify a flow through its rxhash. The reason that
510 * we do not check rxq no. is because some cards(e.g 82599), chooses
511 * the rxq based on the txq where the last packet of the flow comes. As
512 * the userspace application move between processors, we may get a
513 * different rxq no. here.
515 static u16 tun_automq_select_queue(struct tun_struct *tun, struct sk_buff *skb)
517 struct tun_flow_entry *e;
521 numqueues = READ_ONCE(tun->numqueues);
523 txq = __skb_get_hash_symmetric(skb);
524 e = tun_flow_find(&tun->flows[tun_hashfn(txq)], txq);
526 tun_flow_save_rps_rxhash(e, txq);
527 txq = e->queue_index;
529 /* use multiply and shift instead of expensive divide */
530 txq = ((u64)txq * numqueues) >> 32;
536 static u16 tun_ebpf_select_queue(struct tun_struct *tun, struct sk_buff *skb)
538 struct tun_prog *prog;
542 numqueues = READ_ONCE(tun->numqueues);
546 prog = rcu_dereference(tun->steering_prog);
548 ret = bpf_prog_run_clear_cb(prog->prog, skb);
550 return ret % numqueues;
553 static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb,
554 struct net_device *sb_dev)
556 struct tun_struct *tun = netdev_priv(dev);
560 if (rcu_dereference(tun->steering_prog))
561 ret = tun_ebpf_select_queue(tun, skb);
563 ret = tun_automq_select_queue(tun, skb);
569 static inline bool tun_not_capable(struct tun_struct *tun)
571 const struct cred *cred = current_cred();
572 struct net *net = dev_net(tun->dev);
574 return ((uid_valid(tun->owner) && !uid_eq(cred->euid, tun->owner)) ||
575 (gid_valid(tun->group) && !in_egroup_p(tun->group))) &&
576 !ns_capable(net->user_ns, CAP_NET_ADMIN);
579 static void tun_set_real_num_queues(struct tun_struct *tun)
581 netif_set_real_num_tx_queues(tun->dev, tun->numqueues);
582 netif_set_real_num_rx_queues(tun->dev, tun->numqueues);
585 static void tun_disable_queue(struct tun_struct *tun, struct tun_file *tfile)
587 tfile->detached = tun;
588 list_add_tail(&tfile->next, &tun->disabled);
592 static struct tun_struct *tun_enable_queue(struct tun_file *tfile)
594 struct tun_struct *tun = tfile->detached;
596 tfile->detached = NULL;
597 list_del_init(&tfile->next);
602 void tun_ptr_free(void *ptr)
606 if (tun_is_xdp_frame(ptr)) {
607 struct xdp_frame *xdpf = tun_ptr_to_xdp(ptr);
609 xdp_return_frame(xdpf);
611 __skb_array_destroy_skb(ptr);
614 EXPORT_SYMBOL_GPL(tun_ptr_free);
616 static void tun_queue_purge(struct tun_file *tfile)
620 while ((ptr = ptr_ring_consume(&tfile->tx_ring)) != NULL)
623 skb_queue_purge(&tfile->sk.sk_write_queue);
624 skb_queue_purge(&tfile->sk.sk_error_queue);
627 static void __tun_detach(struct tun_file *tfile, bool clean)
629 struct tun_file *ntfile;
630 struct tun_struct *tun;
632 tun = rtnl_dereference(tfile->tun);
635 tun_napi_disable(tfile);
639 if (tun && !tfile->detached) {
640 u16 index = tfile->queue_index;
641 BUG_ON(index >= tun->numqueues);
643 rcu_assign_pointer(tun->tfiles[index],
644 tun->tfiles[tun->numqueues - 1]);
645 ntfile = rtnl_dereference(tun->tfiles[index]);
646 ntfile->queue_index = index;
647 rcu_assign_pointer(tun->tfiles[tun->numqueues - 1],
652 RCU_INIT_POINTER(tfile->tun, NULL);
653 sock_put(&tfile->sk);
655 tun_disable_queue(tun, tfile);
658 tun_flow_delete_by_queue(tun, tun->numqueues + 1);
659 /* Drop read queue */
660 tun_queue_purge(tfile);
661 tun_set_real_num_queues(tun);
662 } else if (tfile->detached && clean) {
663 tun = tun_enable_queue(tfile);
664 sock_put(&tfile->sk);
668 if (tun && tun->numqueues == 0 && tun->numdisabled == 0) {
669 netif_carrier_off(tun->dev);
671 if (!(tun->flags & IFF_PERSIST) &&
672 tun->dev->reg_state == NETREG_REGISTERED)
673 unregister_netdevice(tun->dev);
676 xdp_rxq_info_unreg(&tfile->xdp_rxq);
677 ptr_ring_cleanup(&tfile->tx_ring, tun_ptr_free);
678 sock_put(&tfile->sk);
682 static void tun_detach(struct tun_file *tfile, bool clean)
684 struct tun_struct *tun;
685 struct net_device *dev;
688 tun = rtnl_dereference(tfile->tun);
689 dev = tun ? tun->dev : NULL;
690 __tun_detach(tfile, clean);
692 netdev_state_change(dev);
696 static void tun_detach_all(struct net_device *dev)
698 struct tun_struct *tun = netdev_priv(dev);
699 struct tun_file *tfile, *tmp;
700 int i, n = tun->numqueues;
702 for (i = 0; i < n; i++) {
703 tfile = rtnl_dereference(tun->tfiles[i]);
705 tun_napi_disable(tfile);
706 tfile->socket.sk->sk_shutdown = RCV_SHUTDOWN;
707 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
708 RCU_INIT_POINTER(tfile->tun, NULL);
711 list_for_each_entry(tfile, &tun->disabled, next) {
712 tfile->socket.sk->sk_shutdown = RCV_SHUTDOWN;
713 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
714 RCU_INIT_POINTER(tfile->tun, NULL);
716 BUG_ON(tun->numqueues != 0);
719 for (i = 0; i < n; i++) {
720 tfile = rtnl_dereference(tun->tfiles[i]);
722 /* Drop read queue */
723 tun_queue_purge(tfile);
724 xdp_rxq_info_unreg(&tfile->xdp_rxq);
725 sock_put(&tfile->sk);
727 list_for_each_entry_safe(tfile, tmp, &tun->disabled, next) {
728 tun_enable_queue(tfile);
729 tun_queue_purge(tfile);
730 xdp_rxq_info_unreg(&tfile->xdp_rxq);
731 sock_put(&tfile->sk);
733 BUG_ON(tun->numdisabled != 0);
735 if (tun->flags & IFF_PERSIST)
736 module_put(THIS_MODULE);
739 static int tun_attach(struct tun_struct *tun, struct file *file,
740 bool skip_filter, bool napi, bool napi_frags,
743 struct tun_file *tfile = file->private_data;
744 struct net_device *dev = tun->dev;
747 err = security_tun_dev_attach(tfile->socket.sk, tun->security);
752 if (rtnl_dereference(tfile->tun) && !tfile->detached)
756 if (!(tun->flags & IFF_MULTI_QUEUE) && tun->numqueues == 1)
760 if (!tfile->detached &&
761 tun->numqueues + tun->numdisabled == MAX_TAP_QUEUES)
766 /* Re-attach the filter to persist device */
767 if (!skip_filter && (tun->filter_attached == true)) {
768 lock_sock(tfile->socket.sk);
769 err = sk_attach_filter(&tun->fprog, tfile->socket.sk);
770 release_sock(tfile->socket.sk);
775 if (!tfile->detached &&
776 ptr_ring_resize(&tfile->tx_ring, dev->tx_queue_len,
777 GFP_KERNEL, tun_ptr_free)) {
782 tfile->queue_index = tun->numqueues;
783 tfile->socket.sk->sk_shutdown &= ~RCV_SHUTDOWN;
785 if (tfile->detached) {
786 /* Re-attach detached tfile, updating XDP queue_index */
787 WARN_ON(!xdp_rxq_info_is_reg(&tfile->xdp_rxq));
789 if (tfile->xdp_rxq.queue_index != tfile->queue_index)
790 tfile->xdp_rxq.queue_index = tfile->queue_index;
792 /* Setup XDP RX-queue info, for new tfile getting attached */
793 err = xdp_rxq_info_reg(&tfile->xdp_rxq,
794 tun->dev, tfile->queue_index);
797 err = xdp_rxq_info_reg_mem_model(&tfile->xdp_rxq,
798 MEM_TYPE_PAGE_SHARED, NULL);
800 xdp_rxq_info_unreg(&tfile->xdp_rxq);
806 if (tfile->detached) {
807 tun_enable_queue(tfile);
809 sock_hold(&tfile->sk);
810 tun_napi_init(tun, tfile, napi, napi_frags);
813 if (rtnl_dereference(tun->xdp_prog))
814 sock_set_flag(&tfile->sk, SOCK_XDP);
816 /* device is allowed to go away first, so no need to hold extra
820 /* Publish tfile->tun and tun->tfiles only after we've fully
821 * initialized tfile; otherwise we risk using half-initialized
825 rcu_assign_pointer(tfile->tun, tun);
826 rcu_assign_pointer(tun->tfiles[tun->numqueues], tfile);
828 tun_set_real_num_queues(tun);
833 static struct tun_struct *tun_get(struct tun_file *tfile)
835 struct tun_struct *tun;
838 tun = rcu_dereference(tfile->tun);
846 static void tun_put(struct tun_struct *tun)
852 static void addr_hash_set(u32 *mask, const u8 *addr)
854 int n = ether_crc(ETH_ALEN, addr) >> 26;
855 mask[n >> 5] |= (1 << (n & 31));
858 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
860 int n = ether_crc(ETH_ALEN, addr) >> 26;
861 return mask[n >> 5] & (1 << (n & 31));
864 static int update_filter(struct tap_filter *filter, void __user *arg)
866 struct { u8 u[ETH_ALEN]; } *addr;
867 struct tun_filter uf;
868 int err, alen, n, nexact;
870 if (copy_from_user(&uf, arg, sizeof(uf)))
879 alen = ETH_ALEN * uf.count;
880 addr = memdup_user(arg + sizeof(uf), alen);
882 return PTR_ERR(addr);
884 /* The filter is updated without holding any locks. Which is
885 * perfectly safe. We disable it first and in the worst
886 * case we'll accept a few undesired packets. */
890 /* Use first set of addresses as an exact filter */
891 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
892 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
896 /* Remaining multicast addresses are hashed,
897 * unicast will leave the filter disabled. */
898 memset(filter->mask, 0, sizeof(filter->mask));
899 for (; n < uf.count; n++) {
900 if (!is_multicast_ether_addr(addr[n].u)) {
901 err = 0; /* no filter */
904 addr_hash_set(filter->mask, addr[n].u);
907 /* For ALLMULTI just set the mask to all ones.
908 * This overrides the mask populated above. */
909 if ((uf.flags & TUN_FLT_ALLMULTI))
910 memset(filter->mask, ~0, sizeof(filter->mask));
912 /* Now enable the filter */
914 filter->count = nexact;
916 /* Return the number of exact filters */
923 /* Returns: 0 - drop, !=0 - accept */
924 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
926 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
928 struct ethhdr *eh = (struct ethhdr *) skb->data;
932 for (i = 0; i < filter->count; i++)
933 if (ether_addr_equal(eh->h_dest, filter->addr[i]))
936 /* Inexact match (multicast only) */
937 if (is_multicast_ether_addr(eh->h_dest))
938 return addr_hash_test(filter->mask, eh->h_dest);
944 * Checks whether the packet is accepted or not.
945 * Returns: 0 - drop, !=0 - accept
947 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
952 return run_filter(filter, skb);
955 /* Network device part of the driver */
957 static const struct ethtool_ops tun_ethtool_ops;
959 /* Net device detach from fd. */
960 static void tun_net_uninit(struct net_device *dev)
965 /* Net device open. */
966 static int tun_net_open(struct net_device *dev)
968 netif_tx_start_all_queues(dev);
973 /* Net device close. */
974 static int tun_net_close(struct net_device *dev)
976 netif_tx_stop_all_queues(dev);
980 /* Net device start xmit */
981 static void tun_automq_xmit(struct tun_struct *tun, struct sk_buff *skb)
984 if (tun->numqueues == 1 && static_branch_unlikely(&rps_needed)) {
985 /* Select queue was not called for the skbuff, so we extract the
986 * RPS hash and save it into the flow_table here.
988 struct tun_flow_entry *e;
991 rxhash = __skb_get_hash_symmetric(skb);
992 e = tun_flow_find(&tun->flows[tun_hashfn(rxhash)], rxhash);
994 tun_flow_save_rps_rxhash(e, rxhash);
999 static unsigned int run_ebpf_filter(struct tun_struct *tun,
1000 struct sk_buff *skb,
1003 struct tun_prog *prog = rcu_dereference(tun->filter_prog);
1006 len = bpf_prog_run_clear_cb(prog->prog, skb);
1011 /* Net device start xmit */
1012 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
1014 struct tun_struct *tun = netdev_priv(dev);
1015 int txq = skb->queue_mapping;
1016 struct tun_file *tfile;
1020 tfile = rcu_dereference(tun->tfiles[txq]);
1022 /* Drop packet if interface is not attached */
1026 if (!rcu_dereference(tun->steering_prog))
1027 tun_automq_xmit(tun, skb);
1029 netif_info(tun, tx_queued, tun->dev, "%s %d\n", __func__, skb->len);
1031 /* Drop if the filter does not like it.
1032 * This is a noop if the filter is disabled.
1033 * Filter can be enabled only for the TAP devices. */
1034 if (!check_filter(&tun->txflt, skb))
1037 if (tfile->socket.sk->sk_filter &&
1038 sk_filter(tfile->socket.sk, skb))
1041 len = run_ebpf_filter(tun, skb, len);
1042 if (len == 0 || pskb_trim(skb, len))
1045 if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
1048 skb_tx_timestamp(skb);
1050 /* Orphan the skb - required as we might hang on to it
1051 * for indefinite time.
1057 if (ptr_ring_produce(&tfile->tx_ring, skb))
1060 /* Notify and wake up reader process */
1061 if (tfile->flags & TUN_FASYNC)
1062 kill_fasync(&tfile->fasync, SIGIO, POLL_IN);
1063 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
1066 return NETDEV_TX_OK;
1069 this_cpu_inc(tun->pcpu_stats->tx_dropped);
1073 return NET_XMIT_DROP;
1076 static void tun_net_mclist(struct net_device *dev)
1079 * This callback is supposed to deal with mc filter in
1080 * _rx_ path and has nothing to do with the _tx_ path.
1081 * In rx path we always accept everything userspace gives us.
1085 static netdev_features_t tun_net_fix_features(struct net_device *dev,
1086 netdev_features_t features)
1088 struct tun_struct *tun = netdev_priv(dev);
1090 return (features & tun->set_features) | (features & ~TUN_USER_FEATURES);
1093 static void tun_set_headroom(struct net_device *dev, int new_hr)
1095 struct tun_struct *tun = netdev_priv(dev);
1097 if (new_hr < NET_SKB_PAD)
1098 new_hr = NET_SKB_PAD;
1100 tun->align = new_hr;
1104 tun_net_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
1106 u32 rx_dropped = 0, tx_dropped = 0, rx_frame_errors = 0;
1107 struct tun_struct *tun = netdev_priv(dev);
1108 struct tun_pcpu_stats *p;
1111 for_each_possible_cpu(i) {
1112 u64 rxpackets, rxbytes, txpackets, txbytes;
1115 p = per_cpu_ptr(tun->pcpu_stats, i);
1117 start = u64_stats_fetch_begin(&p->syncp);
1118 rxpackets = u64_stats_read(&p->rx_packets);
1119 rxbytes = u64_stats_read(&p->rx_bytes);
1120 txpackets = u64_stats_read(&p->tx_packets);
1121 txbytes = u64_stats_read(&p->tx_bytes);
1122 } while (u64_stats_fetch_retry(&p->syncp, start));
1124 stats->rx_packets += rxpackets;
1125 stats->rx_bytes += rxbytes;
1126 stats->tx_packets += txpackets;
1127 stats->tx_bytes += txbytes;
1130 rx_dropped += p->rx_dropped;
1131 rx_frame_errors += p->rx_frame_errors;
1132 tx_dropped += p->tx_dropped;
1134 stats->rx_dropped = rx_dropped;
1135 stats->rx_frame_errors = rx_frame_errors;
1136 stats->tx_dropped = tx_dropped;
1139 static int tun_xdp_set(struct net_device *dev, struct bpf_prog *prog,
1140 struct netlink_ext_ack *extack)
1142 struct tun_struct *tun = netdev_priv(dev);
1143 struct tun_file *tfile;
1144 struct bpf_prog *old_prog;
1147 old_prog = rtnl_dereference(tun->xdp_prog);
1148 rcu_assign_pointer(tun->xdp_prog, prog);
1150 bpf_prog_put(old_prog);
1152 for (i = 0; i < tun->numqueues; i++) {
1153 tfile = rtnl_dereference(tun->tfiles[i]);
1155 sock_set_flag(&tfile->sk, SOCK_XDP);
1157 sock_reset_flag(&tfile->sk, SOCK_XDP);
1159 list_for_each_entry(tfile, &tun->disabled, next) {
1161 sock_set_flag(&tfile->sk, SOCK_XDP);
1163 sock_reset_flag(&tfile->sk, SOCK_XDP);
1169 static int tun_xdp(struct net_device *dev, struct netdev_bpf *xdp)
1171 switch (xdp->command) {
1172 case XDP_SETUP_PROG:
1173 return tun_xdp_set(dev, xdp->prog, xdp->extack);
1179 static int tun_net_change_carrier(struct net_device *dev, bool new_carrier)
1182 struct tun_struct *tun = netdev_priv(dev);
1184 if (!tun->numqueues)
1187 netif_carrier_on(dev);
1189 netif_carrier_off(dev);
1194 static const struct net_device_ops tun_netdev_ops = {
1195 .ndo_uninit = tun_net_uninit,
1196 .ndo_open = tun_net_open,
1197 .ndo_stop = tun_net_close,
1198 .ndo_start_xmit = tun_net_xmit,
1199 .ndo_fix_features = tun_net_fix_features,
1200 .ndo_select_queue = tun_select_queue,
1201 .ndo_set_rx_headroom = tun_set_headroom,
1202 .ndo_get_stats64 = tun_net_get_stats64,
1203 .ndo_change_carrier = tun_net_change_carrier,
1206 static void __tun_xdp_flush_tfile(struct tun_file *tfile)
1208 /* Notify and wake up reader process */
1209 if (tfile->flags & TUN_FASYNC)
1210 kill_fasync(&tfile->fasync, SIGIO, POLL_IN);
1211 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
1214 static int tun_xdp_xmit(struct net_device *dev, int n,
1215 struct xdp_frame **frames, u32 flags)
1217 struct tun_struct *tun = netdev_priv(dev);
1218 struct tun_file *tfile;
1224 if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
1230 numqueues = READ_ONCE(tun->numqueues);
1233 return -ENXIO; /* Caller will free/return all frames */
1236 tfile = rcu_dereference(tun->tfiles[smp_processor_id() %
1238 if (unlikely(!tfile))
1241 spin_lock(&tfile->tx_ring.producer_lock);
1242 for (i = 0; i < n; i++) {
1243 struct xdp_frame *xdp = frames[i];
1244 /* Encode the XDP flag into lowest bit for consumer to differ
1245 * XDP buffer from sk_buff.
1247 void *frame = tun_xdp_to_ptr(xdp);
1249 if (__ptr_ring_produce(&tfile->tx_ring, frame)) {
1250 this_cpu_inc(tun->pcpu_stats->tx_dropped);
1251 xdp_return_frame_rx_napi(xdp);
1255 spin_unlock(&tfile->tx_ring.producer_lock);
1257 if (flags & XDP_XMIT_FLUSH)
1258 __tun_xdp_flush_tfile(tfile);
1264 static int tun_xdp_tx(struct net_device *dev, struct xdp_buff *xdp)
1266 struct xdp_frame *frame = xdp_convert_buff_to_frame(xdp);
1268 if (unlikely(!frame))
1271 return tun_xdp_xmit(dev, 1, &frame, XDP_XMIT_FLUSH);
1274 static const struct net_device_ops tap_netdev_ops = {
1275 .ndo_uninit = tun_net_uninit,
1276 .ndo_open = tun_net_open,
1277 .ndo_stop = tun_net_close,
1278 .ndo_start_xmit = tun_net_xmit,
1279 .ndo_fix_features = tun_net_fix_features,
1280 .ndo_set_rx_mode = tun_net_mclist,
1281 .ndo_set_mac_address = eth_mac_addr,
1282 .ndo_validate_addr = eth_validate_addr,
1283 .ndo_select_queue = tun_select_queue,
1284 .ndo_features_check = passthru_features_check,
1285 .ndo_set_rx_headroom = tun_set_headroom,
1286 .ndo_get_stats64 = tun_net_get_stats64,
1288 .ndo_xdp_xmit = tun_xdp_xmit,
1289 .ndo_change_carrier = tun_net_change_carrier,
1292 static void tun_flow_init(struct tun_struct *tun)
1296 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++)
1297 INIT_HLIST_HEAD(&tun->flows[i]);
1299 tun->ageing_time = TUN_FLOW_EXPIRE;
1300 timer_setup(&tun->flow_gc_timer, tun_flow_cleanup, 0);
1301 mod_timer(&tun->flow_gc_timer,
1302 round_jiffies_up(jiffies + tun->ageing_time));
1305 static void tun_flow_uninit(struct tun_struct *tun)
1307 del_timer_sync(&tun->flow_gc_timer);
1308 tun_flow_flush(tun);
1312 #define MAX_MTU 65535
1314 /* Initialize net device. */
1315 static void tun_net_init(struct net_device *dev)
1317 struct tun_struct *tun = netdev_priv(dev);
1319 switch (tun->flags & TUN_TYPE_MASK) {
1321 dev->netdev_ops = &tun_netdev_ops;
1322 dev->header_ops = &ip_tunnel_header_ops;
1324 /* Point-to-Point TUN Device */
1325 dev->hard_header_len = 0;
1329 /* Zero header length */
1330 dev->type = ARPHRD_NONE;
1331 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1335 dev->netdev_ops = &tap_netdev_ops;
1336 /* Ethernet TAP Device */
1338 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1339 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1341 eth_hw_addr_random(dev);
1346 dev->min_mtu = MIN_MTU;
1347 dev->max_mtu = MAX_MTU - dev->hard_header_len;
1350 static bool tun_sock_writeable(struct tun_struct *tun, struct tun_file *tfile)
1352 struct sock *sk = tfile->socket.sk;
1354 return (tun->dev->flags & IFF_UP) && sock_writeable(sk);
1357 /* Character device part */
1360 static __poll_t tun_chr_poll(struct file *file, poll_table *wait)
1362 struct tun_file *tfile = file->private_data;
1363 struct tun_struct *tun = tun_get(tfile);
1370 sk = tfile->socket.sk;
1372 poll_wait(file, sk_sleep(sk), wait);
1374 if (!ptr_ring_empty(&tfile->tx_ring))
1375 mask |= EPOLLIN | EPOLLRDNORM;
1377 /* Make sure SOCKWQ_ASYNC_NOSPACE is set if not writable to
1378 * guarantee EPOLLOUT to be raised by either here or
1379 * tun_sock_write_space(). Then process could get notification
1380 * after it writes to a down device and meets -EIO.
1382 if (tun_sock_writeable(tun, tfile) ||
1383 (!test_and_set_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
1384 tun_sock_writeable(tun, tfile)))
1385 mask |= EPOLLOUT | EPOLLWRNORM;
1387 if (tun->dev->reg_state != NETREG_REGISTERED)
1394 static struct sk_buff *tun_napi_alloc_frags(struct tun_file *tfile,
1396 const struct iov_iter *it)
1398 struct sk_buff *skb;
1403 if (it->nr_segs > MAX_SKB_FRAGS + 1)
1404 return ERR_PTR(-ENOMEM);
1407 skb = napi_get_frags(&tfile->napi);
1410 return ERR_PTR(-ENOMEM);
1412 linear = iov_iter_single_seg_count(it);
1413 err = __skb_grow(skb, linear);
1418 skb->data_len = len - linear;
1419 skb->truesize += skb->data_len;
1421 for (i = 1; i < it->nr_segs; i++) {
1422 size_t fragsz = it->iov[i].iov_len;
1426 if (fragsz == 0 || fragsz > PAGE_SIZE) {
1430 frag = netdev_alloc_frag(fragsz);
1435 page = virt_to_head_page(frag);
1436 skb_fill_page_desc(skb, i - 1, page,
1437 frag - page_address(page), fragsz);
1442 /* frees skb and all frags allocated with napi_alloc_frag() */
1443 napi_free_frags(&tfile->napi);
1444 return ERR_PTR(err);
1447 /* prepad is the amount to reserve at front. len is length after that.
1448 * linear is a hint as to how much to copy (usually headers). */
1449 static struct sk_buff *tun_alloc_skb(struct tun_file *tfile,
1450 size_t prepad, size_t len,
1451 size_t linear, int noblock)
1453 struct sock *sk = tfile->socket.sk;
1454 struct sk_buff *skb;
1457 /* Under a page? Don't bother with paged skb. */
1458 if (prepad + len < PAGE_SIZE || !linear)
1461 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
1464 return ERR_PTR(err);
1466 skb_reserve(skb, prepad);
1467 skb_put(skb, linear);
1468 skb->data_len = len - linear;
1469 skb->len += len - linear;
1474 static void tun_rx_batched(struct tun_struct *tun, struct tun_file *tfile,
1475 struct sk_buff *skb, int more)
1477 struct sk_buff_head *queue = &tfile->sk.sk_write_queue;
1478 struct sk_buff_head process_queue;
1479 u32 rx_batched = tun->rx_batched;
1482 if (!rx_batched || (!more && skb_queue_empty(queue))) {
1484 skb_record_rx_queue(skb, tfile->queue_index);
1485 netif_receive_skb(skb);
1490 spin_lock(&queue->lock);
1491 if (!more || skb_queue_len(queue) == rx_batched) {
1492 __skb_queue_head_init(&process_queue);
1493 skb_queue_splice_tail_init(queue, &process_queue);
1496 __skb_queue_tail(queue, skb);
1498 spin_unlock(&queue->lock);
1501 struct sk_buff *nskb;
1504 while ((nskb = __skb_dequeue(&process_queue))) {
1505 skb_record_rx_queue(nskb, tfile->queue_index);
1506 netif_receive_skb(nskb);
1508 skb_record_rx_queue(skb, tfile->queue_index);
1509 netif_receive_skb(skb);
1514 static bool tun_can_build_skb(struct tun_struct *tun, struct tun_file *tfile,
1515 int len, int noblock, bool zerocopy)
1517 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
1520 if (tfile->socket.sk->sk_sndbuf != INT_MAX)
1529 if (SKB_DATA_ALIGN(len + TUN_RX_PAD) +
1530 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) > PAGE_SIZE)
1536 static struct sk_buff *__tun_build_skb(struct tun_file *tfile,
1537 struct page_frag *alloc_frag, char *buf,
1538 int buflen, int len, int pad)
1540 struct sk_buff *skb = build_skb(buf, buflen);
1543 return ERR_PTR(-ENOMEM);
1545 skb_reserve(skb, pad);
1547 skb_set_owner_w(skb, tfile->socket.sk);
1549 get_page(alloc_frag->page);
1550 alloc_frag->offset += buflen;
1555 static int tun_xdp_act(struct tun_struct *tun, struct bpf_prog *xdp_prog,
1556 struct xdp_buff *xdp, u32 act)
1562 err = xdp_do_redirect(tun->dev, xdp, xdp_prog);
1567 err = tun_xdp_tx(tun->dev, xdp);
1574 bpf_warn_invalid_xdp_action(act);
1577 trace_xdp_exception(tun->dev, xdp_prog, act);
1580 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1587 static struct sk_buff *tun_build_skb(struct tun_struct *tun,
1588 struct tun_file *tfile,
1589 struct iov_iter *from,
1590 struct virtio_net_hdr *hdr,
1591 int len, int *skb_xdp)
1593 struct page_frag *alloc_frag = ¤t->task_frag;
1594 struct bpf_prog *xdp_prog;
1595 int buflen = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
1598 int pad = TUN_RX_PAD;
1602 xdp_prog = rcu_dereference(tun->xdp_prog);
1604 pad += XDP_PACKET_HEADROOM;
1605 buflen += SKB_DATA_ALIGN(len + pad);
1608 alloc_frag->offset = ALIGN((u64)alloc_frag->offset, SMP_CACHE_BYTES);
1609 if (unlikely(!skb_page_frag_refill(buflen, alloc_frag, GFP_KERNEL)))
1610 return ERR_PTR(-ENOMEM);
1612 buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
1613 copied = copy_page_from_iter(alloc_frag->page,
1614 alloc_frag->offset + pad,
1617 return ERR_PTR(-EFAULT);
1619 /* There's a small window that XDP may be set after the check
1620 * of xdp_prog above, this should be rare and for simplicity
1621 * we do XDP on skb in case the headroom is not enough.
1623 if (hdr->gso_type || !xdp_prog) {
1625 return __tun_build_skb(tfile, alloc_frag, buf, buflen, len,
1633 xdp_prog = rcu_dereference(tun->xdp_prog);
1635 struct xdp_buff xdp;
1638 xdp.data_hard_start = buf;
1639 xdp.data = buf + pad;
1640 xdp_set_data_meta_invalid(&xdp);
1641 xdp.data_end = xdp.data + len;
1642 xdp.rxq = &tfile->xdp_rxq;
1643 xdp.frame_sz = buflen;
1645 act = bpf_prog_run_xdp(xdp_prog, &xdp);
1646 if (act == XDP_REDIRECT || act == XDP_TX) {
1647 get_page(alloc_frag->page);
1648 alloc_frag->offset += buflen;
1650 err = tun_xdp_act(tun, xdp_prog, &xdp, act);
1652 if (act == XDP_REDIRECT || act == XDP_TX)
1653 put_page(alloc_frag->page);
1657 if (err == XDP_REDIRECT)
1659 if (err != XDP_PASS)
1662 pad = xdp.data - xdp.data_hard_start;
1663 len = xdp.data_end - xdp.data;
1668 return __tun_build_skb(tfile, alloc_frag, buf, buflen, len, pad);
1676 /* Get packet from user space buffer */
1677 static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
1678 void *msg_control, struct iov_iter *from,
1679 int noblock, bool more)
1681 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
1682 struct sk_buff *skb;
1683 size_t total_len = iov_iter_count(from);
1684 size_t len = total_len, align = tun->align, linear;
1685 struct virtio_net_hdr gso = { 0 };
1686 struct tun_pcpu_stats *stats;
1689 bool zerocopy = false;
1693 bool frags = tun_napi_frags_enabled(tfile);
1695 if (!(tun->flags & IFF_NO_PI)) {
1696 if (len < sizeof(pi))
1700 if (!copy_from_iter_full(&pi, sizeof(pi), from))
1704 if (tun->flags & IFF_VNET_HDR) {
1705 int vnet_hdr_sz = READ_ONCE(tun->vnet_hdr_sz);
1707 if (len < vnet_hdr_sz)
1711 if (!copy_from_iter_full(&gso, sizeof(gso), from))
1714 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
1715 tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2 > tun16_to_cpu(tun, gso.hdr_len))
1716 gso.hdr_len = cpu_to_tun16(tun, tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2);
1718 if (tun16_to_cpu(tun, gso.hdr_len) > len)
1720 iov_iter_advance(from, vnet_hdr_sz - sizeof(gso));
1723 if ((tun->flags & TUN_TYPE_MASK) == IFF_TAP) {
1724 align += NET_IP_ALIGN;
1725 if (unlikely(len < ETH_HLEN ||
1726 (gso.hdr_len && tun16_to_cpu(tun, gso.hdr_len) < ETH_HLEN)))
1730 good_linear = SKB_MAX_HEAD(align);
1733 struct iov_iter i = *from;
1735 /* There are 256 bytes to be copied in skb, so there is
1736 * enough room for skb expand head in case it is used.
1737 * The rest of the buffer is mapped from userspace.
1739 copylen = gso.hdr_len ? tun16_to_cpu(tun, gso.hdr_len) : GOODCOPY_LEN;
1740 if (copylen > good_linear)
1741 copylen = good_linear;
1743 iov_iter_advance(&i, copylen);
1744 if (iov_iter_npages(&i, INT_MAX) <= MAX_SKB_FRAGS)
1748 if (!frags && tun_can_build_skb(tun, tfile, len, noblock, zerocopy)) {
1749 /* For the packet that is not easy to be processed
1750 * (e.g gso or jumbo packet), we will do it at after
1751 * skb was created with generic XDP routine.
1753 skb = tun_build_skb(tun, tfile, from, &gso, len, &skb_xdp);
1755 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1756 return PTR_ERR(skb);
1763 if (tun16_to_cpu(tun, gso.hdr_len) > good_linear)
1764 linear = good_linear;
1766 linear = tun16_to_cpu(tun, gso.hdr_len);
1770 mutex_lock(&tfile->napi_mutex);
1771 skb = tun_napi_alloc_frags(tfile, copylen, from);
1772 /* tun_napi_alloc_frags() enforces a layout for the skb.
1773 * If zerocopy is enabled, then this layout will be
1774 * overwritten by zerocopy_sg_from_iter().
1778 skb = tun_alloc_skb(tfile, align, copylen, linear,
1783 if (PTR_ERR(skb) != -EAGAIN)
1784 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1786 mutex_unlock(&tfile->napi_mutex);
1787 return PTR_ERR(skb);
1791 err = zerocopy_sg_from_iter(skb, from);
1793 err = skb_copy_datagram_from_iter(skb, 0, from, len);
1798 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1801 tfile->napi.skb = NULL;
1802 mutex_unlock(&tfile->napi_mutex);
1809 if (virtio_net_hdr_to_skb(skb, &gso, tun_is_little_endian(tun))) {
1810 this_cpu_inc(tun->pcpu_stats->rx_frame_errors);
1813 tfile->napi.skb = NULL;
1814 mutex_unlock(&tfile->napi_mutex);
1820 switch (tun->flags & TUN_TYPE_MASK) {
1822 if (tun->flags & IFF_NO_PI) {
1823 u8 ip_version = skb->len ? (skb->data[0] >> 4) : 0;
1825 switch (ip_version) {
1827 pi.proto = htons(ETH_P_IP);
1830 pi.proto = htons(ETH_P_IPV6);
1833 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1839 skb_reset_mac_header(skb);
1840 skb->protocol = pi.proto;
1841 skb->dev = tun->dev;
1844 if (frags && !pskb_may_pull(skb, ETH_HLEN)) {
1848 skb->protocol = eth_type_trans(skb, tun->dev);
1852 /* copy skb_ubuf_info for callback when skb has no error */
1854 skb_shinfo(skb)->destructor_arg = msg_control;
1855 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
1856 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
1857 } else if (msg_control) {
1858 struct ubuf_info *uarg = msg_control;
1859 uarg->callback(uarg, false);
1862 skb_reset_network_header(skb);
1863 skb_probe_transport_header(skb);
1864 skb_record_rx_queue(skb, tfile->queue_index);
1867 struct bpf_prog *xdp_prog;
1872 xdp_prog = rcu_dereference(tun->xdp_prog);
1874 ret = do_xdp_generic(xdp_prog, skb);
1875 if (ret != XDP_PASS) {
1879 tfile->napi.skb = NULL;
1880 mutex_unlock(&tfile->napi_mutex);
1889 /* Compute the costly rx hash only if needed for flow updates.
1890 * We may get a very small possibility of OOO during switching, not
1891 * worth to optimize.
1893 if (!rcu_access_pointer(tun->steering_prog) && tun->numqueues > 1 &&
1895 rxhash = __skb_get_hash_symmetric(skb);
1898 if (unlikely(!(tun->dev->flags & IFF_UP))) {
1907 /* Exercise flow dissector code path. */
1908 skb_push(skb, ETH_HLEN);
1909 headlen = eth_get_headlen(tun->dev, skb->data,
1912 if (unlikely(headlen > skb_headlen(skb))) {
1913 this_cpu_inc(tun->pcpu_stats->rx_dropped);
1914 napi_free_frags(&tfile->napi);
1916 mutex_unlock(&tfile->napi_mutex);
1922 napi_gro_frags(&tfile->napi);
1924 mutex_unlock(&tfile->napi_mutex);
1925 } else if (tfile->napi_enabled) {
1926 struct sk_buff_head *queue = &tfile->sk.sk_write_queue;
1929 spin_lock_bh(&queue->lock);
1930 __skb_queue_tail(queue, skb);
1931 queue_len = skb_queue_len(queue);
1932 spin_unlock(&queue->lock);
1934 if (!more || queue_len > NAPI_POLL_WEIGHT)
1935 napi_schedule(&tfile->napi);
1938 } else if (!IS_ENABLED(CONFIG_4KSTACKS)) {
1939 tun_rx_batched(tun, tfile, skb, more);
1945 stats = get_cpu_ptr(tun->pcpu_stats);
1946 u64_stats_update_begin(&stats->syncp);
1947 u64_stats_inc(&stats->rx_packets);
1948 u64_stats_add(&stats->rx_bytes, len);
1949 u64_stats_update_end(&stats->syncp);
1953 tun_flow_update(tun, rxhash, tfile);
1958 static ssize_t tun_chr_write_iter(struct kiocb *iocb, struct iov_iter *from)
1960 struct file *file = iocb->ki_filp;
1961 struct tun_file *tfile = file->private_data;
1962 struct tun_struct *tun = tun_get(tfile);
1969 if ((file->f_flags & O_NONBLOCK) || (iocb->ki_flags & IOCB_NOWAIT))
1972 result = tun_get_user(tun, tfile, NULL, from, noblock, false);
1978 static ssize_t tun_put_user_xdp(struct tun_struct *tun,
1979 struct tun_file *tfile,
1980 struct xdp_frame *xdp_frame,
1981 struct iov_iter *iter)
1983 int vnet_hdr_sz = 0;
1984 size_t size = xdp_frame->len;
1985 struct tun_pcpu_stats *stats;
1988 if (tun->flags & IFF_VNET_HDR) {
1989 struct virtio_net_hdr gso = { 0 };
1991 vnet_hdr_sz = READ_ONCE(tun->vnet_hdr_sz);
1992 if (unlikely(iov_iter_count(iter) < vnet_hdr_sz))
1994 if (unlikely(copy_to_iter(&gso, sizeof(gso), iter) !=
1997 iov_iter_advance(iter, vnet_hdr_sz - sizeof(gso));
2000 ret = copy_to_iter(xdp_frame->data, size, iter) + vnet_hdr_sz;
2002 stats = get_cpu_ptr(tun->pcpu_stats);
2003 u64_stats_update_begin(&stats->syncp);
2004 u64_stats_inc(&stats->tx_packets);
2005 u64_stats_add(&stats->tx_bytes, ret);
2006 u64_stats_update_end(&stats->syncp);
2007 put_cpu_ptr(tun->pcpu_stats);
2012 /* Put packet to the user space buffer */
2013 static ssize_t tun_put_user(struct tun_struct *tun,
2014 struct tun_file *tfile,
2015 struct sk_buff *skb,
2016 struct iov_iter *iter)
2018 struct tun_pi pi = { 0, skb->protocol };
2019 struct tun_pcpu_stats *stats;
2021 int vlan_offset = 0;
2023 int vnet_hdr_sz = 0;
2025 if (skb_vlan_tag_present(skb))
2026 vlan_hlen = VLAN_HLEN;
2028 if (tun->flags & IFF_VNET_HDR)
2029 vnet_hdr_sz = READ_ONCE(tun->vnet_hdr_sz);
2031 total = skb->len + vlan_hlen + vnet_hdr_sz;
2033 if (!(tun->flags & IFF_NO_PI)) {
2034 if (iov_iter_count(iter) < sizeof(pi))
2037 total += sizeof(pi);
2038 if (iov_iter_count(iter) < total) {
2039 /* Packet will be striped */
2040 pi.flags |= TUN_PKT_STRIP;
2043 if (copy_to_iter(&pi, sizeof(pi), iter) != sizeof(pi))
2048 struct virtio_net_hdr gso;
2050 if (iov_iter_count(iter) < vnet_hdr_sz)
2053 if (virtio_net_hdr_from_skb(skb, &gso,
2054 tun_is_little_endian(tun), true,
2056 struct skb_shared_info *sinfo = skb_shinfo(skb);
2057 pr_err("unexpected GSO type: "
2058 "0x%x, gso_size %d, hdr_len %d\n",
2059 sinfo->gso_type, tun16_to_cpu(tun, gso.gso_size),
2060 tun16_to_cpu(tun, gso.hdr_len));
2061 print_hex_dump(KERN_ERR, "tun: ",
2064 min((int)tun16_to_cpu(tun, gso.hdr_len), 64), true);
2069 if (copy_to_iter(&gso, sizeof(gso), iter) != sizeof(gso))
2072 iov_iter_advance(iter, vnet_hdr_sz - sizeof(gso));
2079 veth.h_vlan_proto = skb->vlan_proto;
2080 veth.h_vlan_TCI = htons(skb_vlan_tag_get(skb));
2082 vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto);
2084 ret = skb_copy_datagram_iter(skb, 0, iter, vlan_offset);
2085 if (ret || !iov_iter_count(iter))
2088 ret = copy_to_iter(&veth, sizeof(veth), iter);
2089 if (ret != sizeof(veth) || !iov_iter_count(iter))
2093 skb_copy_datagram_iter(skb, vlan_offset, iter, skb->len - vlan_offset);
2096 /* caller is in process context, */
2097 stats = get_cpu_ptr(tun->pcpu_stats);
2098 u64_stats_update_begin(&stats->syncp);
2099 u64_stats_inc(&stats->tx_packets);
2100 u64_stats_add(&stats->tx_bytes, skb->len + vlan_hlen);
2101 u64_stats_update_end(&stats->syncp);
2102 put_cpu_ptr(tun->pcpu_stats);
2107 static void *tun_ring_recv(struct tun_file *tfile, int noblock, int *err)
2109 DECLARE_WAITQUEUE(wait, current);
2113 ptr = ptr_ring_consume(&tfile->tx_ring);
2121 add_wait_queue(&tfile->socket.wq.wait, &wait);
2124 set_current_state(TASK_INTERRUPTIBLE);
2125 ptr = ptr_ring_consume(&tfile->tx_ring);
2128 if (signal_pending(current)) {
2129 error = -ERESTARTSYS;
2132 if (tfile->socket.sk->sk_shutdown & RCV_SHUTDOWN) {
2140 __set_current_state(TASK_RUNNING);
2141 remove_wait_queue(&tfile->socket.wq.wait, &wait);
2148 static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
2149 struct iov_iter *to,
2150 int noblock, void *ptr)
2155 if (!iov_iter_count(to)) {
2161 /* Read frames from ring */
2162 ptr = tun_ring_recv(tfile, noblock, &err);
2167 if (tun_is_xdp_frame(ptr)) {
2168 struct xdp_frame *xdpf = tun_ptr_to_xdp(ptr);
2170 ret = tun_put_user_xdp(tun, tfile, xdpf, to);
2171 xdp_return_frame(xdpf);
2173 struct sk_buff *skb = ptr;
2175 ret = tun_put_user(tun, tfile, skb, to);
2176 if (unlikely(ret < 0))
2185 static ssize_t tun_chr_read_iter(struct kiocb *iocb, struct iov_iter *to)
2187 struct file *file = iocb->ki_filp;
2188 struct tun_file *tfile = file->private_data;
2189 struct tun_struct *tun = tun_get(tfile);
2190 ssize_t len = iov_iter_count(to), ret;
2196 if ((file->f_flags & O_NONBLOCK) || (iocb->ki_flags & IOCB_NOWAIT))
2199 ret = tun_do_read(tun, tfile, to, noblock, NULL);
2200 ret = min_t(ssize_t, ret, len);
2207 static void tun_prog_free(struct rcu_head *rcu)
2209 struct tun_prog *prog = container_of(rcu, struct tun_prog, rcu);
2211 bpf_prog_destroy(prog->prog);
2215 static int __tun_set_ebpf(struct tun_struct *tun,
2216 struct tun_prog __rcu **prog_p,
2217 struct bpf_prog *prog)
2219 struct tun_prog *old, *new = NULL;
2222 new = kmalloc(sizeof(*new), GFP_KERNEL);
2228 spin_lock_bh(&tun->lock);
2229 old = rcu_dereference_protected(*prog_p,
2230 lockdep_is_held(&tun->lock));
2231 rcu_assign_pointer(*prog_p, new);
2232 spin_unlock_bh(&tun->lock);
2235 call_rcu(&old->rcu, tun_prog_free);
2240 static void tun_free_netdev(struct net_device *dev)
2242 struct tun_struct *tun = netdev_priv(dev);
2244 BUG_ON(!(list_empty(&tun->disabled)));
2246 free_percpu(tun->pcpu_stats);
2247 /* We clear pcpu_stats so that tun_set_iff() can tell if
2248 * tun_free_netdev() has been called from register_netdevice().
2250 tun->pcpu_stats = NULL;
2252 tun_flow_uninit(tun);
2253 security_tun_dev_free_security(tun->security);
2254 __tun_set_ebpf(tun, &tun->steering_prog, NULL);
2255 __tun_set_ebpf(tun, &tun->filter_prog, NULL);
2258 static void tun_setup(struct net_device *dev)
2260 struct tun_struct *tun = netdev_priv(dev);
2262 tun->owner = INVALID_UID;
2263 tun->group = INVALID_GID;
2264 tun_default_link_ksettings(dev, &tun->link_ksettings);
2266 dev->ethtool_ops = &tun_ethtool_ops;
2267 dev->needs_free_netdev = true;
2268 dev->priv_destructor = tun_free_netdev;
2269 /* We prefer our own queue length */
2270 dev->tx_queue_len = TUN_READQ_SIZE;
2273 /* Trivial set of netlink ops to allow deleting tun or tap
2274 * device with netlink.
2276 static int tun_validate(struct nlattr *tb[], struct nlattr *data[],
2277 struct netlink_ext_ack *extack)
2279 NL_SET_ERR_MSG(extack,
2280 "tun/tap creation via rtnetlink is not supported.");
2284 static size_t tun_get_size(const struct net_device *dev)
2286 BUILD_BUG_ON(sizeof(u32) != sizeof(uid_t));
2287 BUILD_BUG_ON(sizeof(u32) != sizeof(gid_t));
2289 return nla_total_size(sizeof(uid_t)) + /* OWNER */
2290 nla_total_size(sizeof(gid_t)) + /* GROUP */
2291 nla_total_size(sizeof(u8)) + /* TYPE */
2292 nla_total_size(sizeof(u8)) + /* PI */
2293 nla_total_size(sizeof(u8)) + /* VNET_HDR */
2294 nla_total_size(sizeof(u8)) + /* PERSIST */
2295 nla_total_size(sizeof(u8)) + /* MULTI_QUEUE */
2296 nla_total_size(sizeof(u32)) + /* NUM_QUEUES */
2297 nla_total_size(sizeof(u32)) + /* NUM_DISABLED_QUEUES */
2301 static int tun_fill_info(struct sk_buff *skb, const struct net_device *dev)
2303 struct tun_struct *tun = netdev_priv(dev);
2305 if (nla_put_u8(skb, IFLA_TUN_TYPE, tun->flags & TUN_TYPE_MASK))
2306 goto nla_put_failure;
2307 if (uid_valid(tun->owner) &&
2308 nla_put_u32(skb, IFLA_TUN_OWNER,
2309 from_kuid_munged(current_user_ns(), tun->owner)))
2310 goto nla_put_failure;
2311 if (gid_valid(tun->group) &&
2312 nla_put_u32(skb, IFLA_TUN_GROUP,
2313 from_kgid_munged(current_user_ns(), tun->group)))
2314 goto nla_put_failure;
2315 if (nla_put_u8(skb, IFLA_TUN_PI, !(tun->flags & IFF_NO_PI)))
2316 goto nla_put_failure;
2317 if (nla_put_u8(skb, IFLA_TUN_VNET_HDR, !!(tun->flags & IFF_VNET_HDR)))
2318 goto nla_put_failure;
2319 if (nla_put_u8(skb, IFLA_TUN_PERSIST, !!(tun->flags & IFF_PERSIST)))
2320 goto nla_put_failure;
2321 if (nla_put_u8(skb, IFLA_TUN_MULTI_QUEUE,
2322 !!(tun->flags & IFF_MULTI_QUEUE)))
2323 goto nla_put_failure;
2324 if (tun->flags & IFF_MULTI_QUEUE) {
2325 if (nla_put_u32(skb, IFLA_TUN_NUM_QUEUES, tun->numqueues))
2326 goto nla_put_failure;
2327 if (nla_put_u32(skb, IFLA_TUN_NUM_DISABLED_QUEUES,
2329 goto nla_put_failure;
2338 static struct rtnl_link_ops tun_link_ops __read_mostly = {
2340 .priv_size = sizeof(struct tun_struct),
2342 .validate = tun_validate,
2343 .get_size = tun_get_size,
2344 .fill_info = tun_fill_info,
2347 static void tun_sock_write_space(struct sock *sk)
2349 struct tun_file *tfile;
2350 wait_queue_head_t *wqueue;
2352 if (!sock_writeable(sk))
2355 if (!test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags))
2358 wqueue = sk_sleep(sk);
2359 if (wqueue && waitqueue_active(wqueue))
2360 wake_up_interruptible_sync_poll(wqueue, EPOLLOUT |
2361 EPOLLWRNORM | EPOLLWRBAND);
2363 tfile = container_of(sk, struct tun_file, sk);
2364 kill_fasync(&tfile->fasync, SIGIO, POLL_OUT);
2367 static void tun_put_page(struct tun_page *tpage)
2370 __page_frag_cache_drain(tpage->page, tpage->count);
2373 static int tun_xdp_one(struct tun_struct *tun,
2374 struct tun_file *tfile,
2375 struct xdp_buff *xdp, int *flush,
2376 struct tun_page *tpage)
2378 unsigned int datasize = xdp->data_end - xdp->data;
2379 struct tun_xdp_hdr *hdr = xdp->data_hard_start;
2380 struct virtio_net_hdr *gso = &hdr->gso;
2381 struct tun_pcpu_stats *stats;
2382 struct bpf_prog *xdp_prog;
2383 struct sk_buff *skb = NULL;
2384 u32 rxhash = 0, act;
2385 int buflen = hdr->buflen;
2387 bool skb_xdp = false;
2390 xdp_prog = rcu_dereference(tun->xdp_prog);
2392 if (gso->gso_type) {
2396 xdp_set_data_meta_invalid(xdp);
2397 xdp->rxq = &tfile->xdp_rxq;
2398 xdp->frame_sz = buflen;
2400 act = bpf_prog_run_xdp(xdp_prog, xdp);
2401 err = tun_xdp_act(tun, xdp_prog, xdp, act);
2403 put_page(virt_to_head_page(xdp->data));
2416 page = virt_to_head_page(xdp->data);
2417 if (tpage->page == page) {
2420 tun_put_page(tpage);
2429 skb = build_skb(xdp->data_hard_start, buflen);
2435 skb_reserve(skb, xdp->data - xdp->data_hard_start);
2436 skb_put(skb, xdp->data_end - xdp->data);
2438 if (virtio_net_hdr_to_skb(skb, gso, tun_is_little_endian(tun))) {
2439 this_cpu_inc(tun->pcpu_stats->rx_frame_errors);
2445 skb->protocol = eth_type_trans(skb, tun->dev);
2446 skb_reset_network_header(skb);
2447 skb_probe_transport_header(skb);
2448 skb_record_rx_queue(skb, tfile->queue_index);
2451 err = do_xdp_generic(xdp_prog, skb);
2452 if (err != XDP_PASS)
2456 if (!rcu_dereference(tun->steering_prog) && tun->numqueues > 1 &&
2458 rxhash = __skb_get_hash_symmetric(skb);
2460 netif_receive_skb(skb);
2462 /* No need for get_cpu_ptr() here since this function is
2463 * always called with bh disabled
2465 stats = this_cpu_ptr(tun->pcpu_stats);
2466 u64_stats_update_begin(&stats->syncp);
2467 u64_stats_inc(&stats->rx_packets);
2468 u64_stats_add(&stats->rx_bytes, datasize);
2469 u64_stats_update_end(&stats->syncp);
2472 tun_flow_update(tun, rxhash, tfile);
2478 static int tun_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
2481 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
2482 struct tun_struct *tun = tun_get(tfile);
2483 struct tun_msg_ctl *ctl = m->msg_control;
2484 struct xdp_buff *xdp;
2489 if (ctl && (ctl->type == TUN_MSG_PTR)) {
2490 struct tun_page tpage;
2494 memset(&tpage, 0, sizeof(tpage));
2499 for (i = 0; i < n; i++) {
2500 xdp = &((struct xdp_buff *)ctl->ptr)[i];
2501 tun_xdp_one(tun, tfile, xdp, &flush, &tpage);
2510 tun_put_page(&tpage);
2516 ret = tun_get_user(tun, tfile, ctl ? ctl->ptr : NULL, &m->msg_iter,
2517 m->msg_flags & MSG_DONTWAIT,
2518 m->msg_flags & MSG_MORE);
2524 static int tun_recvmsg(struct socket *sock, struct msghdr *m, size_t total_len,
2527 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
2528 struct tun_struct *tun = tun_get(tfile);
2529 void *ptr = m->msg_control;
2537 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC|MSG_ERRQUEUE)) {
2541 if (flags & MSG_ERRQUEUE) {
2542 ret = sock_recv_errqueue(sock->sk, m, total_len,
2543 SOL_PACKET, TUN_TX_TIMESTAMP);
2546 ret = tun_do_read(tun, tfile, &m->msg_iter, flags & MSG_DONTWAIT, ptr);
2547 if (ret > (ssize_t)total_len) {
2548 m->msg_flags |= MSG_TRUNC;
2549 ret = flags & MSG_TRUNC ? ret : total_len;
2562 static int tun_ptr_peek_len(void *ptr)
2565 if (tun_is_xdp_frame(ptr)) {
2566 struct xdp_frame *xdpf = tun_ptr_to_xdp(ptr);
2570 return __skb_array_len_with_tag(ptr);
2576 static int tun_peek_len(struct socket *sock)
2578 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
2579 struct tun_struct *tun;
2582 tun = tun_get(tfile);
2586 ret = PTR_RING_PEEK_CALL(&tfile->tx_ring, tun_ptr_peek_len);
2592 /* Ops structure to mimic raw sockets with tun */
2593 static const struct proto_ops tun_socket_ops = {
2594 .peek_len = tun_peek_len,
2595 .sendmsg = tun_sendmsg,
2596 .recvmsg = tun_recvmsg,
2599 static struct proto tun_proto = {
2601 .owner = THIS_MODULE,
2602 .obj_size = sizeof(struct tun_file),
2605 static int tun_flags(struct tun_struct *tun)
2607 return tun->flags & (TUN_FEATURES | IFF_PERSIST | IFF_TUN | IFF_TAP);
2610 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
2613 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
2614 return sprintf(buf, "0x%x\n", tun_flags(tun));
2617 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
2620 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
2621 return uid_valid(tun->owner)?
2622 sprintf(buf, "%u\n",
2623 from_kuid_munged(current_user_ns(), tun->owner)):
2624 sprintf(buf, "-1\n");
2627 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
2630 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
2631 return gid_valid(tun->group) ?
2632 sprintf(buf, "%u\n",
2633 from_kgid_munged(current_user_ns(), tun->group)):
2634 sprintf(buf, "-1\n");
2637 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
2638 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
2639 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
2641 static struct attribute *tun_dev_attrs[] = {
2642 &dev_attr_tun_flags.attr,
2643 &dev_attr_owner.attr,
2644 &dev_attr_group.attr,
2648 static const struct attribute_group tun_attr_group = {
2649 .attrs = tun_dev_attrs
2652 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
2654 struct tun_struct *tun;
2655 struct tun_file *tfile = file->private_data;
2656 struct net_device *dev;
2659 if (tfile->detached)
2662 if ((ifr->ifr_flags & IFF_NAPI_FRAGS)) {
2663 if (!capable(CAP_NET_ADMIN))
2666 if (!(ifr->ifr_flags & IFF_NAPI) ||
2667 (ifr->ifr_flags & TUN_TYPE_MASK) != IFF_TAP)
2671 dev = __dev_get_by_name(net, ifr->ifr_name);
2673 if (ifr->ifr_flags & IFF_TUN_EXCL)
2675 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
2676 tun = netdev_priv(dev);
2677 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
2678 tun = netdev_priv(dev);
2682 if (!!(ifr->ifr_flags & IFF_MULTI_QUEUE) !=
2683 !!(tun->flags & IFF_MULTI_QUEUE))
2686 if (tun_not_capable(tun))
2688 err = security_tun_dev_open(tun->security);
2692 err = tun_attach(tun, file, ifr->ifr_flags & IFF_NOFILTER,
2693 ifr->ifr_flags & IFF_NAPI,
2694 ifr->ifr_flags & IFF_NAPI_FRAGS, true);
2698 if (tun->flags & IFF_MULTI_QUEUE &&
2699 (tun->numqueues + tun->numdisabled > 1)) {
2700 /* One or more queue has already been attached, no need
2701 * to initialize the device again.
2703 netdev_state_change(dev);
2707 tun->flags = (tun->flags & ~TUN_FEATURES) |
2708 (ifr->ifr_flags & TUN_FEATURES);
2710 netdev_state_change(dev);
2713 unsigned long flags = 0;
2714 int queues = ifr->ifr_flags & IFF_MULTI_QUEUE ?
2717 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
2719 err = security_tun_dev_create();
2724 if (ifr->ifr_flags & IFF_TUN) {
2728 } else if (ifr->ifr_flags & IFF_TAP) {
2736 name = ifr->ifr_name;
2738 dev = alloc_netdev_mqs(sizeof(struct tun_struct), name,
2739 NET_NAME_UNKNOWN, tun_setup, queues,
2745 dev_net_set(dev, net);
2746 dev->rtnl_link_ops = &tun_link_ops;
2747 dev->ifindex = tfile->ifindex;
2748 dev->sysfs_groups[0] = &tun_attr_group;
2750 tun = netdev_priv(dev);
2753 tun->txflt.count = 0;
2754 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
2756 tun->align = NET_SKB_PAD;
2757 tun->filter_attached = false;
2758 tun->sndbuf = tfile->socket.sk->sk_sndbuf;
2759 tun->rx_batched = 0;
2760 RCU_INIT_POINTER(tun->steering_prog, NULL);
2762 tun->pcpu_stats = netdev_alloc_pcpu_stats(struct tun_pcpu_stats);
2763 if (!tun->pcpu_stats) {
2768 spin_lock_init(&tun->lock);
2770 err = security_tun_dev_alloc_security(&tun->security);
2777 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
2778 TUN_USER_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
2779 NETIF_F_HW_VLAN_STAG_TX;
2780 dev->features = dev->hw_features | NETIF_F_LLTX;
2781 dev->vlan_features = dev->features &
2782 ~(NETIF_F_HW_VLAN_CTAG_TX |
2783 NETIF_F_HW_VLAN_STAG_TX);
2785 tun->flags = (tun->flags & ~TUN_FEATURES) |
2786 (ifr->ifr_flags & TUN_FEATURES);
2788 INIT_LIST_HEAD(&tun->disabled);
2789 err = tun_attach(tun, file, false, ifr->ifr_flags & IFF_NAPI,
2790 ifr->ifr_flags & IFF_NAPI_FRAGS, false);
2794 err = register_netdevice(tun->dev);
2797 /* free_netdev() won't check refcnt, to aovid race
2798 * with dev_put() we need publish tun after registration.
2800 rcu_assign_pointer(tfile->tun, tun);
2803 netif_carrier_on(tun->dev);
2805 /* Make sure persistent devices do not get stuck in
2808 if (netif_running(tun->dev))
2809 netif_tx_wake_all_queues(tun->dev);
2811 strcpy(ifr->ifr_name, tun->dev->name);
2815 tun_detach_all(dev);
2816 /* We are here because register_netdevice() has failed.
2817 * If register_netdevice() already called tun_free_netdev()
2818 * while dealing with the error, tun->pcpu_stats has been cleared.
2820 if (!tun->pcpu_stats)
2824 tun_flow_uninit(tun);
2825 security_tun_dev_free_security(tun->security);
2827 free_percpu(tun->pcpu_stats);
2833 static void tun_get_iff(struct tun_struct *tun, struct ifreq *ifr)
2835 strcpy(ifr->ifr_name, tun->dev->name);
2837 ifr->ifr_flags = tun_flags(tun);
2841 /* This is like a cut-down ethtool ops, except done via tun fd so no
2842 * privs required. */
2843 static int set_offload(struct tun_struct *tun, unsigned long arg)
2845 netdev_features_t features = 0;
2847 if (arg & TUN_F_CSUM) {
2848 features |= NETIF_F_HW_CSUM;
2851 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
2852 if (arg & TUN_F_TSO_ECN) {
2853 features |= NETIF_F_TSO_ECN;
2854 arg &= ~TUN_F_TSO_ECN;
2856 if (arg & TUN_F_TSO4)
2857 features |= NETIF_F_TSO;
2858 if (arg & TUN_F_TSO6)
2859 features |= NETIF_F_TSO6;
2860 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
2866 /* This gives the user a way to test for new features in future by
2867 * trying to set them. */
2871 tun->set_features = features;
2872 tun->dev->wanted_features &= ~TUN_USER_FEATURES;
2873 tun->dev->wanted_features |= features;
2874 netdev_update_features(tun->dev);
2879 static void tun_detach_filter(struct tun_struct *tun, int n)
2882 struct tun_file *tfile;
2884 for (i = 0; i < n; i++) {
2885 tfile = rtnl_dereference(tun->tfiles[i]);
2886 lock_sock(tfile->socket.sk);
2887 sk_detach_filter(tfile->socket.sk);
2888 release_sock(tfile->socket.sk);
2891 tun->filter_attached = false;
2894 static int tun_attach_filter(struct tun_struct *tun)
2897 struct tun_file *tfile;
2899 for (i = 0; i < tun->numqueues; i++) {
2900 tfile = rtnl_dereference(tun->tfiles[i]);
2901 lock_sock(tfile->socket.sk);
2902 ret = sk_attach_filter(&tun->fprog, tfile->socket.sk);
2903 release_sock(tfile->socket.sk);
2905 tun_detach_filter(tun, i);
2910 tun->filter_attached = true;
2914 static void tun_set_sndbuf(struct tun_struct *tun)
2916 struct tun_file *tfile;
2919 for (i = 0; i < tun->numqueues; i++) {
2920 tfile = rtnl_dereference(tun->tfiles[i]);
2921 tfile->socket.sk->sk_sndbuf = tun->sndbuf;
2925 static int tun_set_queue(struct file *file, struct ifreq *ifr)
2927 struct tun_file *tfile = file->private_data;
2928 struct tun_struct *tun;
2933 if (ifr->ifr_flags & IFF_ATTACH_QUEUE) {
2934 tun = tfile->detached;
2939 ret = security_tun_dev_attach_queue(tun->security);
2942 ret = tun_attach(tun, file, false, tun->flags & IFF_NAPI,
2943 tun->flags & IFF_NAPI_FRAGS, true);
2944 } else if (ifr->ifr_flags & IFF_DETACH_QUEUE) {
2945 tun = rtnl_dereference(tfile->tun);
2946 if (!tun || !(tun->flags & IFF_MULTI_QUEUE) || tfile->detached)
2949 __tun_detach(tfile, false);
2954 netdev_state_change(tun->dev);
2961 static int tun_set_ebpf(struct tun_struct *tun, struct tun_prog __rcu **prog_p,
2964 struct bpf_prog *prog;
2967 if (copy_from_user(&fd, data, sizeof(fd)))
2973 prog = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER);
2975 return PTR_ERR(prog);
2978 return __tun_set_ebpf(tun, prog_p, prog);
2981 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
2982 unsigned long arg, int ifreq_len)
2984 struct tun_file *tfile = file->private_data;
2985 struct net *net = sock_net(&tfile->sk);
2986 struct tun_struct *tun;
2987 void __user* argp = (void __user*)arg;
2988 unsigned int ifindex, carrier;
2996 bool do_notify = false;
2998 if (cmd == TUNSETIFF || cmd == TUNSETQUEUE ||
2999 (_IOC_TYPE(cmd) == SOCK_IOC_TYPE && cmd != SIOCGSKNS)) {
3000 if (copy_from_user(&ifr, argp, ifreq_len))
3003 memset(&ifr, 0, sizeof(ifr));
3005 if (cmd == TUNGETFEATURES) {
3006 /* Currently this just means: "what IFF flags are valid?".
3007 * This is needed because we never checked for invalid flags on
3010 return put_user(IFF_TUN | IFF_TAP | TUN_FEATURES,
3011 (unsigned int __user*)argp);
3012 } else if (cmd == TUNSETQUEUE) {
3013 return tun_set_queue(file, &ifr);
3014 } else if (cmd == SIOCGSKNS) {
3015 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
3017 return open_related_ns(&net->ns, get_net_ns);
3023 tun = tun_get(tfile);
3024 if (cmd == TUNSETIFF) {
3029 ifr.ifr_name[IFNAMSIZ-1] = '\0';
3031 ret = tun_set_iff(net, file, &ifr);
3036 if (copy_to_user(argp, &ifr, ifreq_len))
3040 if (cmd == TUNSETIFINDEX) {
3046 if (copy_from_user(&ifindex, argp, sizeof(ifindex)))
3050 tfile->ifindex = ifindex;
3058 netif_info(tun, drv, tun->dev, "tun_chr_ioctl cmd %u\n", cmd);
3060 net = dev_net(tun->dev);
3064 tun_get_iff(tun, &ifr);
3066 if (tfile->detached)
3067 ifr.ifr_flags |= IFF_DETACH_QUEUE;
3068 if (!tfile->socket.sk->sk_filter)
3069 ifr.ifr_flags |= IFF_NOFILTER;
3071 if (copy_to_user(argp, &ifr, ifreq_len))
3076 /* Disable/Enable checksum */
3078 /* [unimplemented] */
3079 netif_info(tun, drv, tun->dev, "ignored: set checksum %s\n",
3080 arg ? "disabled" : "enabled");
3084 /* Disable/Enable persist mode. Keep an extra reference to the
3085 * module to prevent the module being unprobed.
3087 if (arg && !(tun->flags & IFF_PERSIST)) {
3088 tun->flags |= IFF_PERSIST;
3089 __module_get(THIS_MODULE);
3092 if (!arg && (tun->flags & IFF_PERSIST)) {
3093 tun->flags &= ~IFF_PERSIST;
3094 module_put(THIS_MODULE);
3098 netif_info(tun, drv, tun->dev, "persist %s\n",
3099 arg ? "enabled" : "disabled");
3103 /* Set owner of the device */
3104 owner = make_kuid(current_user_ns(), arg);
3105 if (!uid_valid(owner)) {
3111 netif_info(tun, drv, tun->dev, "owner set to %u\n",
3112 from_kuid(&init_user_ns, tun->owner));
3116 /* Set group of the device */
3117 group = make_kgid(current_user_ns(), arg);
3118 if (!gid_valid(group)) {
3124 netif_info(tun, drv, tun->dev, "group set to %u\n",
3125 from_kgid(&init_user_ns, tun->group));
3129 /* Only allow setting the type when the interface is down */
3130 if (tun->dev->flags & IFF_UP) {
3131 netif_info(tun, drv, tun->dev,
3132 "Linktype set failed because interface is up\n");
3135 tun->dev->type = (int) arg;
3136 netif_info(tun, drv, tun->dev, "linktype set to %d\n",
3143 tun->msg_enable = (u32)arg;
3147 ret = set_offload(tun, arg);
3150 case TUNSETTXFILTER:
3151 /* Can be set only for TAPs */
3153 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
3155 ret = update_filter(&tun->txflt, (void __user *)arg);
3159 /* Get hw address */
3160 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
3161 ifr.ifr_hwaddr.sa_family = tun->dev->type;
3162 if (copy_to_user(argp, &ifr, ifreq_len))
3167 /* Set hw address */
3168 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr, NULL);
3172 sndbuf = tfile->socket.sk->sk_sndbuf;
3173 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
3178 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
3187 tun->sndbuf = sndbuf;
3188 tun_set_sndbuf(tun);
3191 case TUNGETVNETHDRSZ:
3192 vnet_hdr_sz = tun->vnet_hdr_sz;
3193 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
3197 case TUNSETVNETHDRSZ:
3198 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
3202 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
3207 tun->vnet_hdr_sz = vnet_hdr_sz;
3211 le = !!(tun->flags & TUN_VNET_LE);
3212 if (put_user(le, (int __user *)argp))
3217 if (get_user(le, (int __user *)argp)) {
3222 tun->flags |= TUN_VNET_LE;
3224 tun->flags &= ~TUN_VNET_LE;
3228 ret = tun_get_vnet_be(tun, argp);
3232 ret = tun_set_vnet_be(tun, argp);
3235 case TUNATTACHFILTER:
3236 /* Can be set only for TAPs */
3238 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
3241 if (copy_from_user(&tun->fprog, argp, sizeof(tun->fprog)))
3244 ret = tun_attach_filter(tun);
3247 case TUNDETACHFILTER:
3248 /* Can be set only for TAPs */
3250 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
3253 tun_detach_filter(tun, tun->numqueues);
3258 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
3261 if (copy_to_user(argp, &tun->fprog, sizeof(tun->fprog)))
3266 case TUNSETSTEERINGEBPF:
3267 ret = tun_set_ebpf(tun, &tun->steering_prog, argp);
3270 case TUNSETFILTEREBPF:
3271 ret = tun_set_ebpf(tun, &tun->filter_prog, argp);
3276 if (copy_from_user(&carrier, argp, sizeof(carrier)))
3279 ret = tun_net_change_carrier(tun->dev, (bool)carrier);
3282 case TUNGETDEVNETNS:
3284 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
3286 ret = open_related_ns(&net->ns, get_net_ns);
3295 netdev_state_change(tun->dev);
3304 static long tun_chr_ioctl(struct file *file,
3305 unsigned int cmd, unsigned long arg)
3307 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
3310 #ifdef CONFIG_COMPAT
3311 static long tun_chr_compat_ioctl(struct file *file,
3312 unsigned int cmd, unsigned long arg)
3317 case TUNSETTXFILTER:
3322 arg = (unsigned long)compat_ptr(arg);
3325 arg = (compat_ulong_t)arg;
3330 * compat_ifreq is shorter than ifreq, so we must not access beyond
3331 * the end of that structure. All fields that are used in this
3332 * driver are compatible though, we don't need to convert the
3335 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
3337 #endif /* CONFIG_COMPAT */
3339 static int tun_chr_fasync(int fd, struct file *file, int on)
3341 struct tun_file *tfile = file->private_data;
3344 if ((ret = fasync_helper(fd, file, on, &tfile->fasync)) < 0)
3348 __f_setown(file, task_pid(current), PIDTYPE_TGID, 0);
3349 tfile->flags |= TUN_FASYNC;
3351 tfile->flags &= ~TUN_FASYNC;
3357 static int tun_chr_open(struct inode *inode, struct file * file)
3359 struct net *net = current->nsproxy->net_ns;
3360 struct tun_file *tfile;
3362 tfile = (struct tun_file *)sk_alloc(net, AF_UNSPEC, GFP_KERNEL,
3366 if (ptr_ring_init(&tfile->tx_ring, 0, GFP_KERNEL)) {
3367 sk_free(&tfile->sk);
3371 mutex_init(&tfile->napi_mutex);
3372 RCU_INIT_POINTER(tfile->tun, NULL);
3376 init_waitqueue_head(&tfile->socket.wq.wait);
3378 tfile->socket.file = file;
3379 tfile->socket.ops = &tun_socket_ops;
3381 sock_init_data(&tfile->socket, &tfile->sk);
3383 tfile->sk.sk_write_space = tun_sock_write_space;
3384 tfile->sk.sk_sndbuf = INT_MAX;
3386 file->private_data = tfile;
3387 INIT_LIST_HEAD(&tfile->next);
3389 sock_set_flag(&tfile->sk, SOCK_ZEROCOPY);
3394 static int tun_chr_close(struct inode *inode, struct file *file)
3396 struct tun_file *tfile = file->private_data;
3398 tun_detach(tfile, true);
3403 #ifdef CONFIG_PROC_FS
3404 static void tun_chr_show_fdinfo(struct seq_file *m, struct file *file)
3406 struct tun_file *tfile = file->private_data;
3407 struct tun_struct *tun;
3410 memset(&ifr, 0, sizeof(ifr));
3413 tun = tun_get(tfile);
3415 tun_get_iff(tun, &ifr);
3421 seq_printf(m, "iff:\t%s\n", ifr.ifr_name);
3425 static const struct file_operations tun_fops = {
3426 .owner = THIS_MODULE,
3427 .llseek = no_llseek,
3428 .read_iter = tun_chr_read_iter,
3429 .write_iter = tun_chr_write_iter,
3430 .poll = tun_chr_poll,
3431 .unlocked_ioctl = tun_chr_ioctl,
3432 #ifdef CONFIG_COMPAT
3433 .compat_ioctl = tun_chr_compat_ioctl,
3435 .open = tun_chr_open,
3436 .release = tun_chr_close,
3437 .fasync = tun_chr_fasync,
3438 #ifdef CONFIG_PROC_FS
3439 .show_fdinfo = tun_chr_show_fdinfo,
3443 static struct miscdevice tun_miscdev = {
3446 .nodename = "net/tun",
3450 /* ethtool interface */
3452 static void tun_default_link_ksettings(struct net_device *dev,
3453 struct ethtool_link_ksettings *cmd)
3455 ethtool_link_ksettings_zero_link_mode(cmd, supported);
3456 ethtool_link_ksettings_zero_link_mode(cmd, advertising);
3457 cmd->base.speed = SPEED_10;
3458 cmd->base.duplex = DUPLEX_FULL;
3459 cmd->base.port = PORT_TP;
3460 cmd->base.phy_address = 0;
3461 cmd->base.autoneg = AUTONEG_DISABLE;
3464 static int tun_get_link_ksettings(struct net_device *dev,
3465 struct ethtool_link_ksettings *cmd)
3467 struct tun_struct *tun = netdev_priv(dev);
3469 memcpy(cmd, &tun->link_ksettings, sizeof(*cmd));
3473 static int tun_set_link_ksettings(struct net_device *dev,
3474 const struct ethtool_link_ksettings *cmd)
3476 struct tun_struct *tun = netdev_priv(dev);
3478 memcpy(&tun->link_ksettings, cmd, sizeof(*cmd));
3482 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
3484 struct tun_struct *tun = netdev_priv(dev);
3486 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
3487 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
3489 switch (tun->flags & TUN_TYPE_MASK) {
3491 strlcpy(info->bus_info, "tun", sizeof(info->bus_info));
3494 strlcpy(info->bus_info, "tap", sizeof(info->bus_info));
3499 static u32 tun_get_msglevel(struct net_device *dev)
3501 struct tun_struct *tun = netdev_priv(dev);
3503 return tun->msg_enable;
3506 static void tun_set_msglevel(struct net_device *dev, u32 value)
3508 struct tun_struct *tun = netdev_priv(dev);
3510 tun->msg_enable = value;
3513 static int tun_get_coalesce(struct net_device *dev,
3514 struct ethtool_coalesce *ec)
3516 struct tun_struct *tun = netdev_priv(dev);
3518 ec->rx_max_coalesced_frames = tun->rx_batched;
3523 static int tun_set_coalesce(struct net_device *dev,
3524 struct ethtool_coalesce *ec)
3526 struct tun_struct *tun = netdev_priv(dev);
3528 if (ec->rx_max_coalesced_frames > NAPI_POLL_WEIGHT)
3529 tun->rx_batched = NAPI_POLL_WEIGHT;
3531 tun->rx_batched = ec->rx_max_coalesced_frames;
3536 static const struct ethtool_ops tun_ethtool_ops = {
3537 .supported_coalesce_params = ETHTOOL_COALESCE_RX_MAX_FRAMES,
3538 .get_drvinfo = tun_get_drvinfo,
3539 .get_msglevel = tun_get_msglevel,
3540 .set_msglevel = tun_set_msglevel,
3541 .get_link = ethtool_op_get_link,
3542 .get_ts_info = ethtool_op_get_ts_info,
3543 .get_coalesce = tun_get_coalesce,
3544 .set_coalesce = tun_set_coalesce,
3545 .get_link_ksettings = tun_get_link_ksettings,
3546 .set_link_ksettings = tun_set_link_ksettings,
3549 static int tun_queue_resize(struct tun_struct *tun)
3551 struct net_device *dev = tun->dev;
3552 struct tun_file *tfile;
3553 struct ptr_ring **rings;
3554 int n = tun->numqueues + tun->numdisabled;
3557 rings = kmalloc_array(n, sizeof(*rings), GFP_KERNEL);
3561 for (i = 0; i < tun->numqueues; i++) {
3562 tfile = rtnl_dereference(tun->tfiles[i]);
3563 rings[i] = &tfile->tx_ring;
3565 list_for_each_entry(tfile, &tun->disabled, next)
3566 rings[i++] = &tfile->tx_ring;
3568 ret = ptr_ring_resize_multiple(rings, n,
3569 dev->tx_queue_len, GFP_KERNEL,
3576 static int tun_device_event(struct notifier_block *unused,
3577 unsigned long event, void *ptr)
3579 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3580 struct tun_struct *tun = netdev_priv(dev);
3583 if (dev->rtnl_link_ops != &tun_link_ops)
3587 case NETDEV_CHANGE_TX_QUEUE_LEN:
3588 if (tun_queue_resize(tun))
3592 for (i = 0; i < tun->numqueues; i++) {
3593 struct tun_file *tfile;
3595 tfile = rtnl_dereference(tun->tfiles[i]);
3596 tfile->socket.sk->sk_write_space(tfile->socket.sk);
3606 static struct notifier_block tun_notifier_block __read_mostly = {
3607 .notifier_call = tun_device_event,
3610 static int __init tun_init(void)
3614 pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
3616 ret = rtnl_link_register(&tun_link_ops);
3618 pr_err("Can't register link_ops\n");
3622 ret = misc_register(&tun_miscdev);
3624 pr_err("Can't register misc device %d\n", TUN_MINOR);
3628 ret = register_netdevice_notifier(&tun_notifier_block);
3630 pr_err("Can't register netdevice notifier\n");
3637 misc_deregister(&tun_miscdev);
3639 rtnl_link_unregister(&tun_link_ops);
3644 static void tun_cleanup(void)
3646 misc_deregister(&tun_miscdev);
3647 rtnl_link_unregister(&tun_link_ops);
3648 unregister_netdevice_notifier(&tun_notifier_block);
3651 /* Get an underlying socket object from tun file. Returns error unless file is
3652 * attached to a device. The returned object works like a packet socket, it
3653 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
3654 * holding a reference to the file for as long as the socket is in use. */
3655 struct socket *tun_get_socket(struct file *file)
3657 struct tun_file *tfile;
3658 if (file->f_op != &tun_fops)
3659 return ERR_PTR(-EINVAL);
3660 tfile = file->private_data;
3662 return ERR_PTR(-EBADFD);
3663 return &tfile->socket;
3665 EXPORT_SYMBOL_GPL(tun_get_socket);
3667 struct ptr_ring *tun_get_tx_ring(struct file *file)
3669 struct tun_file *tfile;
3671 if (file->f_op != &tun_fops)
3672 return ERR_PTR(-EINVAL);
3673 tfile = file->private_data;
3675 return ERR_PTR(-EBADFD);
3676 return &tfile->tx_ring;
3678 EXPORT_SYMBOL_GPL(tun_get_tx_ring);
3680 module_init(tun_init);
3681 module_exit(tun_cleanup);
3682 MODULE_DESCRIPTION(DRV_DESCRIPTION);
3683 MODULE_AUTHOR(DRV_COPYRIGHT);
3684 MODULE_LICENSE("GPL");
3685 MODULE_ALIAS_MISCDEV(TUN_MINOR);
3686 MODULE_ALIAS("devname:net/tun");