2 * TUN - Universal TUN/TAP device driver.
3 * Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * $Id: tun.c,v 1.15 2002/03/01 02:44:24 maxk Exp $
21 * Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14
22 * Add TUNSETLINK ioctl to set the link encapsulation
24 * Mark Smith <markzzzsmith@yahoo.com.au>
25 * Use eth_random_addr() for tap MAC address.
27 * Harald Roelle <harald.roelle@ifi.lmu.de> 2004/04/20
28 * Fixes in packet dropping, queue length setting and queue wakeup.
29 * Increased default tx queue length.
33 * Daniel Podlejski <underley@underley.eu.org>
34 * Modifications for 2.3.99-pre5 kernel.
37 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
39 #define DRV_NAME "tun"
40 #define DRV_VERSION "1.6"
41 #define DRV_DESCRIPTION "Universal TUN/TAP device driver"
42 #define DRV_COPYRIGHT "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>"
44 #include <linux/module.h>
45 #include <linux/errno.h>
46 #include <linux/kernel.h>
47 #include <linux/major.h>
48 #include <linux/slab.h>
49 #include <linux/poll.h>
50 #include <linux/fcntl.h>
51 #include <linux/init.h>
52 #include <linux/skbuff.h>
53 #include <linux/netdevice.h>
54 #include <linux/etherdevice.h>
55 #include <linux/miscdevice.h>
56 #include <linux/ethtool.h>
57 #include <linux/rtnetlink.h>
58 #include <linux/compat.h>
60 #include <linux/if_arp.h>
61 #include <linux/if_ether.h>
62 #include <linux/if_tun.h>
63 #include <linux/if_vlan.h>
64 #include <linux/crc32.h>
65 #include <linux/nsproxy.h>
66 #include <linux/virtio_net.h>
67 #include <linux/rcupdate.h>
69 #include <net/net_namespace.h>
70 #include <net/netns/generic.h>
71 #include <net/rtnetlink.h>
73 #include <linux/seq_file.h>
74 #include <linux/uio.h>
76 #include <asm/uaccess.h>
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 /* TUN device flags */
109 /* IFF_ATTACH_QUEUE is never stored in device flags,
110 * overload it to mean fasync when stored there.
112 #define TUN_FASYNC IFF_ATTACH_QUEUE
113 /* High bits in flags field are unused. */
114 #define TUN_VNET_LE 0x80000000
116 #define TUN_FEATURES (IFF_NO_PI | IFF_ONE_QUEUE | IFF_VNET_HDR | \
118 #define GOODCOPY_LEN 128
120 #define FLT_EXACT_COUNT 8
122 unsigned int count; /* Number of addrs. Zero means disabled */
123 u32 mask[2]; /* Mask of the hashed addrs */
124 unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN];
127 /* DEFAULT_MAX_NUM_RSS_QUEUES were chosen to let the rx/tx queues allocated for
128 * the netdevice to be fit in one page. So we can make sure the success of
129 * memory allocation. TODO: increase the limit. */
130 #define MAX_TAP_QUEUES DEFAULT_MAX_NUM_RSS_QUEUES
131 #define MAX_TAP_FLOWS 4096
133 #define TUN_FLOW_EXPIRE (3 * HZ)
135 /* A tun_file connects an open character device to a tuntap netdevice. It
136 * also contains all socket related structures (except sock_fprog and tap_filter)
137 * to serve as one transmit queue for tuntap device. The sock_fprog and
138 * tap_filter were kept in tun_struct since they were used for filtering for the
139 * netdevice not for a specific queue (at least I didn't see the requirement for
143 * The tun_file and tun_struct are loosely coupled, the pointer from one to the
144 * other can only be read while rcu_read_lock or rtnl_lock is held.
148 struct socket socket;
150 struct tun_struct __rcu *tun;
152 struct fasync_struct *fasync;
153 /* only used for fasnyc */
157 unsigned int ifindex;
159 struct list_head next;
160 struct tun_struct *detached;
163 struct tun_flow_entry {
164 struct hlist_node hash_link;
166 struct tun_struct *tun;
171 unsigned long updated;
174 #define TUN_NUM_FLOW_ENTRIES 1024
176 /* Since the socket were moved to tun_file, to preserve the behavior of persist
177 * device, socket filter, sndbuf and vnet header size were restore when the
178 * file were attached to a persist device.
181 struct tun_file __rcu *tfiles[MAX_TAP_QUEUES];
182 unsigned int numqueues;
187 struct net_device *dev;
188 netdev_features_t set_features;
189 #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \
194 struct tap_filter txflt;
195 struct sock_fprog fprog;
196 /* protected by rtnl lock */
197 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;
211 static inline u16 tun16_to_cpu(struct tun_struct *tun, __virtio16 val)
213 return __virtio16_to_cpu(tun->flags & TUN_VNET_LE, val);
216 static inline __virtio16 cpu_to_tun16(struct tun_struct *tun, u16 val)
218 return __cpu_to_virtio16(tun->flags & TUN_VNET_LE, val);
221 static inline u32 tun_hashfn(u32 rxhash)
223 return rxhash & 0x3ff;
226 static struct tun_flow_entry *tun_flow_find(struct hlist_head *head, u32 rxhash)
228 struct tun_flow_entry *e;
230 hlist_for_each_entry_rcu(e, head, hash_link) {
231 if (e->rxhash == rxhash)
237 static struct tun_flow_entry *tun_flow_create(struct tun_struct *tun,
238 struct hlist_head *head,
239 u32 rxhash, u16 queue_index)
241 struct tun_flow_entry *e = kmalloc(sizeof(*e), GFP_ATOMIC);
244 tun_debug(KERN_INFO, tun, "create flow: hash %u index %u\n",
245 rxhash, queue_index);
246 e->updated = jiffies;
249 e->queue_index = queue_index;
251 hlist_add_head_rcu(&e->hash_link, head);
257 static void tun_flow_delete(struct tun_struct *tun, struct tun_flow_entry *e)
259 tun_debug(KERN_INFO, tun, "delete flow: hash %u index %u\n",
260 e->rxhash, e->queue_index);
261 sock_rps_reset_flow_hash(e->rps_rxhash);
262 hlist_del_rcu(&e->hash_link);
267 static void tun_flow_flush(struct tun_struct *tun)
271 spin_lock_bh(&tun->lock);
272 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
273 struct tun_flow_entry *e;
274 struct hlist_node *n;
276 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link)
277 tun_flow_delete(tun, e);
279 spin_unlock_bh(&tun->lock);
282 static void tun_flow_delete_by_queue(struct tun_struct *tun, u16 queue_index)
286 spin_lock_bh(&tun->lock);
287 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
288 struct tun_flow_entry *e;
289 struct hlist_node *n;
291 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
292 if (e->queue_index == queue_index)
293 tun_flow_delete(tun, e);
296 spin_unlock_bh(&tun->lock);
299 static void tun_flow_cleanup(unsigned long data)
301 struct tun_struct *tun = (struct tun_struct *)data;
302 unsigned long delay = tun->ageing_time;
303 unsigned long next_timer = jiffies + delay;
304 unsigned long count = 0;
307 tun_debug(KERN_INFO, tun, "tun_flow_cleanup\n");
309 spin_lock_bh(&tun->lock);
310 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
311 struct tun_flow_entry *e;
312 struct hlist_node *n;
314 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
315 unsigned long this_timer;
317 this_timer = e->updated + delay;
318 if (time_before_eq(this_timer, jiffies))
319 tun_flow_delete(tun, e);
320 else if (time_before(this_timer, next_timer))
321 next_timer = this_timer;
326 mod_timer(&tun->flow_gc_timer, round_jiffies_up(next_timer));
327 spin_unlock_bh(&tun->lock);
330 static void tun_flow_update(struct tun_struct *tun, u32 rxhash,
331 struct tun_file *tfile)
333 struct hlist_head *head;
334 struct tun_flow_entry *e;
335 unsigned long delay = tun->ageing_time;
336 u16 queue_index = tfile->queue_index;
341 head = &tun->flows[tun_hashfn(rxhash)];
345 /* We may get a very small possibility of OOO during switching, not
346 * worth to optimize.*/
347 if (tun->numqueues == 1 || tfile->detached)
350 e = tun_flow_find(head, rxhash);
352 /* TODO: keep queueing to old queue until it's empty? */
353 e->queue_index = queue_index;
354 e->updated = jiffies;
355 sock_rps_record_flow_hash(e->rps_rxhash);
357 spin_lock_bh(&tun->lock);
358 if (!tun_flow_find(head, rxhash) &&
359 tun->flow_count < MAX_TAP_FLOWS)
360 tun_flow_create(tun, head, rxhash, queue_index);
362 if (!timer_pending(&tun->flow_gc_timer))
363 mod_timer(&tun->flow_gc_timer,
364 round_jiffies_up(jiffies + delay));
365 spin_unlock_bh(&tun->lock);
373 * Save the hash received in the stack receive path and update the
374 * flow_hash table accordingly.
376 static inline void tun_flow_save_rps_rxhash(struct tun_flow_entry *e, u32 hash)
378 if (unlikely(e->rps_rxhash != hash)) {
379 sock_rps_reset_flow_hash(e->rps_rxhash);
380 e->rps_rxhash = hash;
384 /* We try to identify a flow through its rxhash first. The reason that
385 * we do not check rxq no. is because some cards(e.g 82599), chooses
386 * the rxq based on the txq where the last packet of the flow comes. As
387 * the userspace application move between processors, we may get a
388 * different rxq no. here. If we could not get rxhash, then we would
389 * hope the rxq no. may help here.
391 static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb,
392 void *accel_priv, select_queue_fallback_t fallback)
394 struct tun_struct *tun = netdev_priv(dev);
395 struct tun_flow_entry *e;
400 numqueues = ACCESS_ONCE(tun->numqueues);
402 txq = skb_get_hash(skb);
404 e = tun_flow_find(&tun->flows[tun_hashfn(txq)], txq);
406 tun_flow_save_rps_rxhash(e, txq);
407 txq = e->queue_index;
409 /* use multiply and shift instead of expensive divide */
410 txq = ((u64)txq * numqueues) >> 32;
411 } else if (likely(skb_rx_queue_recorded(skb))) {
412 txq = skb_get_rx_queue(skb);
413 while (unlikely(txq >= numqueues))
421 static inline bool tun_not_capable(struct tun_struct *tun)
423 const struct cred *cred = current_cred();
424 struct net *net = dev_net(tun->dev);
426 return ((uid_valid(tun->owner) && !uid_eq(cred->euid, tun->owner)) ||
427 (gid_valid(tun->group) && !in_egroup_p(tun->group))) &&
428 !ns_capable(net->user_ns, CAP_NET_ADMIN);
431 static void tun_set_real_num_queues(struct tun_struct *tun)
433 netif_set_real_num_tx_queues(tun->dev, tun->numqueues);
434 netif_set_real_num_rx_queues(tun->dev, tun->numqueues);
437 static void tun_disable_queue(struct tun_struct *tun, struct tun_file *tfile)
439 tfile->detached = tun;
440 list_add_tail(&tfile->next, &tun->disabled);
444 static struct tun_struct *tun_enable_queue(struct tun_file *tfile)
446 struct tun_struct *tun = tfile->detached;
448 tfile->detached = NULL;
449 list_del_init(&tfile->next);
454 static void tun_queue_purge(struct tun_file *tfile)
456 skb_queue_purge(&tfile->sk.sk_receive_queue);
457 skb_queue_purge(&tfile->sk.sk_error_queue);
460 static void __tun_detach(struct tun_file *tfile, bool clean)
462 struct tun_file *ntfile;
463 struct tun_struct *tun;
465 tun = rtnl_dereference(tfile->tun);
467 if (tun && !tfile->detached) {
468 u16 index = tfile->queue_index;
469 BUG_ON(index >= tun->numqueues);
471 rcu_assign_pointer(tun->tfiles[index],
472 tun->tfiles[tun->numqueues - 1]);
473 ntfile = rtnl_dereference(tun->tfiles[index]);
474 ntfile->queue_index = index;
478 RCU_INIT_POINTER(tfile->tun, NULL);
479 sock_put(&tfile->sk);
481 tun_disable_queue(tun, tfile);
484 tun_flow_delete_by_queue(tun, tun->numqueues + 1);
485 /* Drop read queue */
486 tun_queue_purge(tfile);
487 tun_set_real_num_queues(tun);
488 } else if (tfile->detached && clean) {
489 tun = tun_enable_queue(tfile);
490 sock_put(&tfile->sk);
494 if (tun && tun->numqueues == 0 && tun->numdisabled == 0) {
495 netif_carrier_off(tun->dev);
497 if (!(tun->flags & IFF_PERSIST) &&
498 tun->dev->reg_state == NETREG_REGISTERED)
499 unregister_netdevice(tun->dev);
502 BUG_ON(!test_bit(SOCK_EXTERNALLY_ALLOCATED,
503 &tfile->socket.flags));
504 sk_release_kernel(&tfile->sk);
508 static void tun_detach(struct tun_file *tfile, bool clean)
511 __tun_detach(tfile, clean);
515 static void tun_detach_all(struct net_device *dev)
517 struct tun_struct *tun = netdev_priv(dev);
518 struct tun_file *tfile, *tmp;
519 int i, n = tun->numqueues;
521 for (i = 0; i < n; i++) {
522 tfile = rtnl_dereference(tun->tfiles[i]);
524 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
525 RCU_INIT_POINTER(tfile->tun, NULL);
528 list_for_each_entry(tfile, &tun->disabled, next) {
529 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
530 RCU_INIT_POINTER(tfile->tun, NULL);
532 BUG_ON(tun->numqueues != 0);
535 for (i = 0; i < n; i++) {
536 tfile = rtnl_dereference(tun->tfiles[i]);
537 /* Drop read queue */
538 tun_queue_purge(tfile);
539 sock_put(&tfile->sk);
541 list_for_each_entry_safe(tfile, tmp, &tun->disabled, next) {
542 tun_enable_queue(tfile);
543 tun_queue_purge(tfile);
544 sock_put(&tfile->sk);
546 BUG_ON(tun->numdisabled != 0);
548 if (tun->flags & IFF_PERSIST)
549 module_put(THIS_MODULE);
552 static int tun_attach(struct tun_struct *tun, struct file *file, bool skip_filter)
554 struct tun_file *tfile = file->private_data;
557 err = security_tun_dev_attach(tfile->socket.sk, tun->security);
562 if (rtnl_dereference(tfile->tun) && !tfile->detached)
566 if (!(tun->flags & IFF_MULTI_QUEUE) && tun->numqueues == 1)
570 if (!tfile->detached &&
571 tun->numqueues + tun->numdisabled == MAX_TAP_QUEUES)
576 /* Re-attach the filter to persist device */
577 if (!skip_filter && (tun->filter_attached == true)) {
578 err = sk_attach_filter(&tun->fprog, tfile->socket.sk);
582 tfile->queue_index = tun->numqueues;
583 rcu_assign_pointer(tfile->tun, tun);
584 rcu_assign_pointer(tun->tfiles[tun->numqueues], tfile);
588 tun_enable_queue(tfile);
590 sock_hold(&tfile->sk);
592 tun_set_real_num_queues(tun);
594 /* device is allowed to go away first, so no need to hold extra
602 static struct tun_struct *__tun_get(struct tun_file *tfile)
604 struct tun_struct *tun;
607 tun = rcu_dereference(tfile->tun);
615 static struct tun_struct *tun_get(struct file *file)
617 return __tun_get(file->private_data);
620 static void tun_put(struct tun_struct *tun)
626 static void addr_hash_set(u32 *mask, const u8 *addr)
628 int n = ether_crc(ETH_ALEN, addr) >> 26;
629 mask[n >> 5] |= (1 << (n & 31));
632 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
634 int n = ether_crc(ETH_ALEN, addr) >> 26;
635 return mask[n >> 5] & (1 << (n & 31));
638 static int update_filter(struct tap_filter *filter, void __user *arg)
640 struct { u8 u[ETH_ALEN]; } *addr;
641 struct tun_filter uf;
642 int err, alen, n, nexact;
644 if (copy_from_user(&uf, arg, sizeof(uf)))
653 alen = ETH_ALEN * uf.count;
654 addr = kmalloc(alen, GFP_KERNEL);
658 if (copy_from_user(addr, arg + sizeof(uf), alen)) {
663 /* The filter is updated without holding any locks. Which is
664 * perfectly safe. We disable it first and in the worst
665 * case we'll accept a few undesired packets. */
669 /* Use first set of addresses as an exact filter */
670 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
671 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
675 /* Remaining multicast addresses are hashed,
676 * unicast will leave the filter disabled. */
677 memset(filter->mask, 0, sizeof(filter->mask));
678 for (; n < uf.count; n++) {
679 if (!is_multicast_ether_addr(addr[n].u)) {
680 err = 0; /* no filter */
683 addr_hash_set(filter->mask, addr[n].u);
686 /* For ALLMULTI just set the mask to all ones.
687 * This overrides the mask populated above. */
688 if ((uf.flags & TUN_FLT_ALLMULTI))
689 memset(filter->mask, ~0, sizeof(filter->mask));
691 /* Now enable the filter */
693 filter->count = nexact;
695 /* Return the number of exact filters */
703 /* Returns: 0 - drop, !=0 - accept */
704 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
706 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
708 struct ethhdr *eh = (struct ethhdr *) skb->data;
712 for (i = 0; i < filter->count; i++)
713 if (ether_addr_equal(eh->h_dest, filter->addr[i]))
716 /* Inexact match (multicast only) */
717 if (is_multicast_ether_addr(eh->h_dest))
718 return addr_hash_test(filter->mask, eh->h_dest);
724 * Checks whether the packet is accepted or not.
725 * Returns: 0 - drop, !=0 - accept
727 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
732 return run_filter(filter, skb);
735 /* Network device part of the driver */
737 static const struct ethtool_ops tun_ethtool_ops;
739 /* Net device detach from fd. */
740 static void tun_net_uninit(struct net_device *dev)
745 /* Net device open. */
746 static int tun_net_open(struct net_device *dev)
748 netif_tx_start_all_queues(dev);
752 /* Net device close. */
753 static int tun_net_close(struct net_device *dev)
755 netif_tx_stop_all_queues(dev);
759 /* Net device start xmit */
760 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
762 struct tun_struct *tun = netdev_priv(dev);
763 int txq = skb->queue_mapping;
764 struct tun_file *tfile;
768 tfile = rcu_dereference(tun->tfiles[txq]);
769 numqueues = ACCESS_ONCE(tun->numqueues);
771 /* Drop packet if interface is not attached */
772 if (txq >= numqueues)
775 if (numqueues == 1) {
776 /* Select queue was not called for the skbuff, so we extract the
777 * RPS hash and save it into the flow_table here.
781 rxhash = skb_get_hash(skb);
783 struct tun_flow_entry *e;
784 e = tun_flow_find(&tun->flows[tun_hashfn(rxhash)],
787 tun_flow_save_rps_rxhash(e, rxhash);
791 tun_debug(KERN_INFO, tun, "tun_net_xmit %d\n", skb->len);
795 /* Drop if the filter does not like it.
796 * This is a noop if the filter is disabled.
797 * Filter can be enabled only for the TAP devices. */
798 if (!check_filter(&tun->txflt, skb))
801 if (tfile->socket.sk->sk_filter &&
802 sk_filter(tfile->socket.sk, skb))
805 /* Limit the number of packets queued by dividing txq length with the
808 if (skb_queue_len(&tfile->socket.sk->sk_receive_queue) * numqueues
809 >= dev->tx_queue_len)
812 if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
816 sock_tx_timestamp(skb->sk, &skb_shinfo(skb)->tx_flags);
817 sw_tx_timestamp(skb);
820 /* Orphan the skb - required as we might hang on to it
821 * for indefinite time.
828 skb_queue_tail(&tfile->socket.sk->sk_receive_queue, skb);
830 /* Notify and wake up reader process */
831 if (tfile->flags & TUN_FASYNC)
832 kill_fasync(&tfile->fasync, SIGIO, POLL_IN);
833 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
839 dev->stats.tx_dropped++;
843 return NET_XMIT_DROP;
846 static void tun_net_mclist(struct net_device *dev)
849 * This callback is supposed to deal with mc filter in
850 * _rx_ path and has nothing to do with the _tx_ path.
851 * In rx path we always accept everything userspace gives us.
856 #define MAX_MTU 65535
859 tun_net_change_mtu(struct net_device *dev, int new_mtu)
861 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
867 static netdev_features_t tun_net_fix_features(struct net_device *dev,
868 netdev_features_t features)
870 struct tun_struct *tun = netdev_priv(dev);
872 return (features & tun->set_features) | (features & ~TUN_USER_FEATURES);
874 #ifdef CONFIG_NET_POLL_CONTROLLER
875 static void tun_poll_controller(struct net_device *dev)
878 * Tun only receives frames when:
879 * 1) the char device endpoint gets data from user space
880 * 2) the tun socket gets a sendmsg call from user space
881 * Since both of those are synchronous operations, we are guaranteed
882 * never to have pending data when we poll for it
883 * so there is nothing to do here but return.
884 * We need this though so netpoll recognizes us as an interface that
885 * supports polling, which enables bridge devices in virt setups to
886 * still use netconsole
891 static const struct net_device_ops tun_netdev_ops = {
892 .ndo_uninit = tun_net_uninit,
893 .ndo_open = tun_net_open,
894 .ndo_stop = tun_net_close,
895 .ndo_start_xmit = tun_net_xmit,
896 .ndo_change_mtu = tun_net_change_mtu,
897 .ndo_fix_features = tun_net_fix_features,
898 .ndo_select_queue = tun_select_queue,
899 #ifdef CONFIG_NET_POLL_CONTROLLER
900 .ndo_poll_controller = tun_poll_controller,
904 static const struct net_device_ops tap_netdev_ops = {
905 .ndo_uninit = tun_net_uninit,
906 .ndo_open = tun_net_open,
907 .ndo_stop = tun_net_close,
908 .ndo_start_xmit = tun_net_xmit,
909 .ndo_change_mtu = tun_net_change_mtu,
910 .ndo_fix_features = tun_net_fix_features,
911 .ndo_set_rx_mode = tun_net_mclist,
912 .ndo_set_mac_address = eth_mac_addr,
913 .ndo_validate_addr = eth_validate_addr,
914 .ndo_select_queue = tun_select_queue,
915 #ifdef CONFIG_NET_POLL_CONTROLLER
916 .ndo_poll_controller = tun_poll_controller,
920 static void tun_flow_init(struct tun_struct *tun)
924 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++)
925 INIT_HLIST_HEAD(&tun->flows[i]);
927 tun->ageing_time = TUN_FLOW_EXPIRE;
928 setup_timer(&tun->flow_gc_timer, tun_flow_cleanup, (unsigned long)tun);
929 mod_timer(&tun->flow_gc_timer,
930 round_jiffies_up(jiffies + tun->ageing_time));
933 static void tun_flow_uninit(struct tun_struct *tun)
935 del_timer_sync(&tun->flow_gc_timer);
939 /* Initialize net device. */
940 static void tun_net_init(struct net_device *dev)
942 struct tun_struct *tun = netdev_priv(dev);
944 switch (tun->flags & TUN_TYPE_MASK) {
946 dev->netdev_ops = &tun_netdev_ops;
948 /* Point-to-Point TUN Device */
949 dev->hard_header_len = 0;
953 /* Zero header length */
954 dev->type = ARPHRD_NONE;
955 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
956 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
960 dev->netdev_ops = &tap_netdev_ops;
961 /* Ethernet TAP Device */
963 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
964 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
966 eth_hw_addr_random(dev);
968 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
973 /* Character device part */
976 static unsigned int tun_chr_poll(struct file *file, poll_table *wait)
978 struct tun_file *tfile = file->private_data;
979 struct tun_struct *tun = __tun_get(tfile);
981 unsigned int mask = 0;
986 sk = tfile->socket.sk;
988 tun_debug(KERN_INFO, tun, "tun_chr_poll\n");
990 poll_wait(file, sk_sleep(sk), wait);
992 if (!skb_queue_empty(&sk->sk_receive_queue))
993 mask |= POLLIN | POLLRDNORM;
995 if (sock_writeable(sk) ||
996 (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
998 mask |= POLLOUT | POLLWRNORM;
1000 if (tun->dev->reg_state != NETREG_REGISTERED)
1007 /* prepad is the amount to reserve at front. len is length after that.
1008 * linear is a hint as to how much to copy (usually headers). */
1009 static struct sk_buff *tun_alloc_skb(struct tun_file *tfile,
1010 size_t prepad, size_t len,
1011 size_t linear, int noblock)
1013 struct sock *sk = tfile->socket.sk;
1014 struct sk_buff *skb;
1017 /* Under a page? Don't bother with paged skb. */
1018 if (prepad + len < PAGE_SIZE || !linear)
1021 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
1024 return ERR_PTR(err);
1026 skb_reserve(skb, prepad);
1027 skb_put(skb, linear);
1028 skb->data_len = len - linear;
1029 skb->len += len - linear;
1034 /* Get packet from user space buffer */
1035 static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
1036 void *msg_control, struct iov_iter *from,
1039 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
1040 struct sk_buff *skb;
1041 size_t total_len = iov_iter_count(from);
1042 size_t len = total_len, align = NET_SKB_PAD, linear;
1043 struct virtio_net_hdr gso = { 0 };
1046 bool zerocopy = false;
1051 if (!(tun->flags & IFF_NO_PI)) {
1052 if (len < sizeof(pi))
1056 n = copy_from_iter(&pi, sizeof(pi), from);
1057 if (n != sizeof(pi))
1061 if (tun->flags & IFF_VNET_HDR) {
1062 if (len < tun->vnet_hdr_sz)
1064 len -= tun->vnet_hdr_sz;
1066 n = copy_from_iter(&gso, sizeof(gso), from);
1067 if (n != sizeof(gso))
1070 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
1071 tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2 > tun16_to_cpu(tun, gso.hdr_len))
1072 gso.hdr_len = cpu_to_tun16(tun, tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2);
1074 if (tun16_to_cpu(tun, gso.hdr_len) > len)
1076 iov_iter_advance(from, tun->vnet_hdr_sz - sizeof(gso));
1079 if ((tun->flags & TUN_TYPE_MASK) == IFF_TAP) {
1080 align += NET_IP_ALIGN;
1081 if (unlikely(len < ETH_HLEN ||
1082 (gso.hdr_len && tun16_to_cpu(tun, gso.hdr_len) < ETH_HLEN)))
1086 good_linear = SKB_MAX_HEAD(align);
1089 struct iov_iter i = *from;
1091 /* There are 256 bytes to be copied in skb, so there is
1092 * enough room for skb expand head in case it is used.
1093 * The rest of the buffer is mapped from userspace.
1095 copylen = gso.hdr_len ? tun16_to_cpu(tun, gso.hdr_len) : GOODCOPY_LEN;
1096 if (copylen > good_linear)
1097 copylen = good_linear;
1099 iov_iter_advance(&i, copylen);
1100 if (iov_iter_npages(&i, INT_MAX) <= MAX_SKB_FRAGS)
1106 if (tun16_to_cpu(tun, gso.hdr_len) > good_linear)
1107 linear = good_linear;
1109 linear = tun16_to_cpu(tun, gso.hdr_len);
1112 skb = tun_alloc_skb(tfile, align, copylen, linear, noblock);
1114 if (PTR_ERR(skb) != -EAGAIN)
1115 tun->dev->stats.rx_dropped++;
1116 return PTR_ERR(skb);
1120 err = zerocopy_sg_from_iter(skb, from);
1122 err = skb_copy_datagram_from_iter(skb, 0, from, len);
1123 if (!err && msg_control) {
1124 struct ubuf_info *uarg = msg_control;
1125 uarg->callback(uarg, false);
1130 tun->dev->stats.rx_dropped++;
1135 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
1136 if (!skb_partial_csum_set(skb, tun16_to_cpu(tun, gso.csum_start),
1137 tun16_to_cpu(tun, gso.csum_offset))) {
1138 tun->dev->stats.rx_frame_errors++;
1144 switch (tun->flags & TUN_TYPE_MASK) {
1146 if (tun->flags & IFF_NO_PI) {
1147 switch (skb->data[0] & 0xf0) {
1149 pi.proto = htons(ETH_P_IP);
1152 pi.proto = htons(ETH_P_IPV6);
1155 tun->dev->stats.rx_dropped++;
1161 skb_reset_mac_header(skb);
1162 skb->protocol = pi.proto;
1163 skb->dev = tun->dev;
1166 skb->protocol = eth_type_trans(skb, tun->dev);
1170 skb_reset_network_header(skb);
1172 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
1174 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
1175 case VIRTIO_NET_HDR_GSO_TCPV4:
1176 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
1178 case VIRTIO_NET_HDR_GSO_TCPV6:
1179 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
1181 case VIRTIO_NET_HDR_GSO_UDP:
1187 netdev_warn(tun->dev,
1188 "%s: using disabled UFO feature; please fix this program\n",
1191 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
1192 if (skb->protocol == htons(ETH_P_IPV6))
1193 ipv6_proxy_select_ident(skb);
1197 tun->dev->stats.rx_frame_errors++;
1202 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
1203 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
1205 skb_shinfo(skb)->gso_size = tun16_to_cpu(tun, gso.gso_size);
1206 if (skb_shinfo(skb)->gso_size == 0) {
1207 tun->dev->stats.rx_frame_errors++;
1212 /* Header must be checked, and gso_segs computed. */
1213 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
1214 skb_shinfo(skb)->gso_segs = 0;
1217 /* copy skb_ubuf_info for callback when skb has no error */
1219 skb_shinfo(skb)->destructor_arg = msg_control;
1220 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
1221 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
1224 skb_probe_transport_header(skb, 0);
1226 rxhash = skb_get_hash(skb);
1229 tun->dev->stats.rx_packets++;
1230 tun->dev->stats.rx_bytes += len;
1232 tun_flow_update(tun, rxhash, tfile);
1236 static ssize_t tun_chr_write_iter(struct kiocb *iocb, struct iov_iter *from)
1238 struct file *file = iocb->ki_filp;
1239 struct tun_struct *tun = tun_get(file);
1240 struct tun_file *tfile = file->private_data;
1246 result = tun_get_user(tun, tfile, NULL, from, file->f_flags & O_NONBLOCK);
1252 /* Put packet to the user space buffer */
1253 static ssize_t tun_put_user(struct tun_struct *tun,
1254 struct tun_file *tfile,
1255 struct sk_buff *skb,
1256 struct iov_iter *iter)
1258 struct tun_pi pi = { 0, skb->protocol };
1260 int vlan_offset = 0;
1262 int vnet_hdr_sz = 0;
1264 if (vlan_tx_tag_present(skb))
1265 vlan_hlen = VLAN_HLEN;
1267 if (tun->flags & IFF_VNET_HDR)
1268 vnet_hdr_sz = tun->vnet_hdr_sz;
1270 total = skb->len + vlan_hlen + vnet_hdr_sz;
1272 if (!(tun->flags & IFF_NO_PI)) {
1273 if (iov_iter_count(iter) < sizeof(pi))
1276 total += sizeof(pi);
1277 if (iov_iter_count(iter) < total) {
1278 /* Packet will be striped */
1279 pi.flags |= TUN_PKT_STRIP;
1282 if (copy_to_iter(&pi, sizeof(pi), iter) != sizeof(pi))
1287 struct virtio_net_hdr gso = { 0 }; /* no info leak */
1288 if (iov_iter_count(iter) < vnet_hdr_sz)
1291 if (skb_is_gso(skb)) {
1292 struct skb_shared_info *sinfo = skb_shinfo(skb);
1294 /* This is a hint as to how much should be linear. */
1295 gso.hdr_len = cpu_to_tun16(tun, skb_headlen(skb));
1296 gso.gso_size = cpu_to_tun16(tun, sinfo->gso_size);
1297 if (sinfo->gso_type & SKB_GSO_TCPV4)
1298 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
1299 else if (sinfo->gso_type & SKB_GSO_TCPV6)
1300 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
1302 pr_err("unexpected GSO type: "
1303 "0x%x, gso_size %d, hdr_len %d\n",
1304 sinfo->gso_type, tun16_to_cpu(tun, gso.gso_size),
1305 tun16_to_cpu(tun, gso.hdr_len));
1306 print_hex_dump(KERN_ERR, "tun: ",
1309 min((int)tun16_to_cpu(tun, gso.hdr_len), 64), true);
1313 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
1314 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
1316 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
1318 if (skb->ip_summed == CHECKSUM_PARTIAL) {
1319 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
1320 gso.csum_start = cpu_to_tun16(tun, skb_checksum_start_offset(skb) +
1322 gso.csum_offset = cpu_to_tun16(tun, skb->csum_offset);
1323 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
1324 gso.flags = VIRTIO_NET_HDR_F_DATA_VALID;
1325 } /* else everything is zero */
1327 if (copy_to_iter(&gso, sizeof(gso), iter) != sizeof(gso))
1330 iov_iter_advance(iter, vnet_hdr_sz - sizeof(gso));
1336 __be16 h_vlan_proto;
1340 veth.h_vlan_proto = skb->vlan_proto;
1341 veth.h_vlan_TCI = htons(vlan_tx_tag_get(skb));
1343 vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto);
1345 ret = skb_copy_datagram_iter(skb, 0, iter, vlan_offset);
1346 if (ret || !iov_iter_count(iter))
1349 ret = copy_to_iter(&veth, sizeof(veth), iter);
1350 if (ret != sizeof(veth) || !iov_iter_count(iter))
1354 skb_copy_datagram_iter(skb, vlan_offset, iter, skb->len - vlan_offset);
1357 tun->dev->stats.tx_packets++;
1358 tun->dev->stats.tx_bytes += skb->len + vlan_hlen;
1363 static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
1364 struct iov_iter *to,
1367 struct sk_buff *skb;
1369 int peeked, err, off = 0;
1371 tun_debug(KERN_INFO, tun, "tun_do_read\n");
1373 if (!iov_iter_count(to))
1376 if (tun->dev->reg_state != NETREG_REGISTERED)
1379 /* Read frames from queue */
1380 skb = __skb_recv_datagram(tfile->socket.sk, noblock ? MSG_DONTWAIT : 0,
1381 &peeked, &off, &err);
1385 ret = tun_put_user(tun, tfile, skb, to);
1386 if (unlikely(ret < 0))
1394 static ssize_t tun_chr_read_iter(struct kiocb *iocb, struct iov_iter *to)
1396 struct file *file = iocb->ki_filp;
1397 struct tun_file *tfile = file->private_data;
1398 struct tun_struct *tun = __tun_get(tfile);
1399 ssize_t len = iov_iter_count(to), ret;
1403 ret = tun_do_read(tun, tfile, to, file->f_flags & O_NONBLOCK);
1404 ret = min_t(ssize_t, ret, len);
1411 static void tun_free_netdev(struct net_device *dev)
1413 struct tun_struct *tun = netdev_priv(dev);
1415 BUG_ON(!(list_empty(&tun->disabled)));
1416 tun_flow_uninit(tun);
1417 security_tun_dev_free_security(tun->security);
1421 static void tun_setup(struct net_device *dev)
1423 struct tun_struct *tun = netdev_priv(dev);
1425 tun->owner = INVALID_UID;
1426 tun->group = INVALID_GID;
1428 dev->ethtool_ops = &tun_ethtool_ops;
1429 dev->destructor = tun_free_netdev;
1432 /* Trivial set of netlink ops to allow deleting tun or tap
1433 * device with netlink.
1435 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
1440 static struct rtnl_link_ops tun_link_ops __read_mostly = {
1442 .priv_size = sizeof(struct tun_struct),
1444 .validate = tun_validate,
1447 static void tun_sock_write_space(struct sock *sk)
1449 struct tun_file *tfile;
1450 wait_queue_head_t *wqueue;
1452 if (!sock_writeable(sk))
1455 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
1458 wqueue = sk_sleep(sk);
1459 if (wqueue && waitqueue_active(wqueue))
1460 wake_up_interruptible_sync_poll(wqueue, POLLOUT |
1461 POLLWRNORM | POLLWRBAND);
1463 tfile = container_of(sk, struct tun_file, sk);
1464 kill_fasync(&tfile->fasync, SIGIO, POLL_OUT);
1467 static int tun_sendmsg(struct kiocb *iocb, struct socket *sock,
1468 struct msghdr *m, size_t total_len)
1471 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1472 struct tun_struct *tun = __tun_get(tfile);
1477 ret = tun_get_user(tun, tfile, m->msg_control, &m->msg_iter,
1478 m->msg_flags & MSG_DONTWAIT);
1483 static int tun_recvmsg(struct kiocb *iocb, struct socket *sock,
1484 struct msghdr *m, size_t total_len,
1487 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1488 struct tun_struct *tun = __tun_get(tfile);
1494 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC|MSG_ERRQUEUE)) {
1498 if (flags & MSG_ERRQUEUE) {
1499 ret = sock_recv_errqueue(sock->sk, m, total_len,
1500 SOL_PACKET, TUN_TX_TIMESTAMP);
1503 ret = tun_do_read(tun, tfile, &m->msg_iter, flags & MSG_DONTWAIT);
1504 if (ret > total_len) {
1505 m->msg_flags |= MSG_TRUNC;
1506 ret = flags & MSG_TRUNC ? ret : total_len;
1513 static int tun_release(struct socket *sock)
1520 /* Ops structure to mimic raw sockets with tun */
1521 static const struct proto_ops tun_socket_ops = {
1522 .sendmsg = tun_sendmsg,
1523 .recvmsg = tun_recvmsg,
1524 .release = tun_release,
1527 static struct proto tun_proto = {
1529 .owner = THIS_MODULE,
1530 .obj_size = sizeof(struct tun_file),
1533 static int tun_flags(struct tun_struct *tun)
1535 return tun->flags & (TUN_FEATURES | IFF_PERSIST | IFF_TUN | IFF_TAP);
1538 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
1541 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1542 return sprintf(buf, "0x%x\n", tun_flags(tun));
1545 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
1548 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1549 return uid_valid(tun->owner)?
1550 sprintf(buf, "%u\n",
1551 from_kuid_munged(current_user_ns(), tun->owner)):
1552 sprintf(buf, "-1\n");
1555 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
1558 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1559 return gid_valid(tun->group) ?
1560 sprintf(buf, "%u\n",
1561 from_kgid_munged(current_user_ns(), tun->group)):
1562 sprintf(buf, "-1\n");
1565 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
1566 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
1567 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
1569 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
1571 struct tun_struct *tun;
1572 struct tun_file *tfile = file->private_data;
1573 struct net_device *dev;
1576 if (tfile->detached)
1579 dev = __dev_get_by_name(net, ifr->ifr_name);
1581 if (ifr->ifr_flags & IFF_TUN_EXCL)
1583 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
1584 tun = netdev_priv(dev);
1585 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
1586 tun = netdev_priv(dev);
1590 if (!!(ifr->ifr_flags & IFF_MULTI_QUEUE) !=
1591 !!(tun->flags & IFF_MULTI_QUEUE))
1594 if (tun_not_capable(tun))
1596 err = security_tun_dev_open(tun->security);
1600 err = tun_attach(tun, file, ifr->ifr_flags & IFF_NOFILTER);
1604 if (tun->flags & IFF_MULTI_QUEUE &&
1605 (tun->numqueues + tun->numdisabled > 1)) {
1606 /* One or more queue has already been attached, no need
1607 * to initialize the device again.
1614 unsigned long flags = 0;
1615 int queues = ifr->ifr_flags & IFF_MULTI_QUEUE ?
1618 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1620 err = security_tun_dev_create();
1625 if (ifr->ifr_flags & IFF_TUN) {
1629 } else if (ifr->ifr_flags & IFF_TAP) {
1637 name = ifr->ifr_name;
1639 dev = alloc_netdev_mqs(sizeof(struct tun_struct), name,
1640 NET_NAME_UNKNOWN, tun_setup, queues,
1646 dev_net_set(dev, net);
1647 dev->rtnl_link_ops = &tun_link_ops;
1648 dev->ifindex = tfile->ifindex;
1650 tun = netdev_priv(dev);
1653 tun->txflt.count = 0;
1654 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
1656 tun->filter_attached = false;
1657 tun->sndbuf = tfile->socket.sk->sk_sndbuf;
1659 spin_lock_init(&tun->lock);
1661 err = security_tun_dev_alloc_security(&tun->security);
1668 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
1669 TUN_USER_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
1670 NETIF_F_HW_VLAN_STAG_TX;
1671 dev->features = dev->hw_features;
1672 dev->vlan_features = dev->features &
1673 ~(NETIF_F_HW_VLAN_CTAG_TX |
1674 NETIF_F_HW_VLAN_STAG_TX);
1676 INIT_LIST_HEAD(&tun->disabled);
1677 err = tun_attach(tun, file, false);
1681 err = register_netdevice(tun->dev);
1685 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
1686 device_create_file(&tun->dev->dev, &dev_attr_owner) ||
1687 device_create_file(&tun->dev->dev, &dev_attr_group))
1688 pr_err("Failed to create tun sysfs files\n");
1691 netif_carrier_on(tun->dev);
1693 tun_debug(KERN_INFO, tun, "tun_set_iff\n");
1695 tun->flags = (tun->flags & ~TUN_FEATURES) |
1696 (ifr->ifr_flags & TUN_FEATURES);
1698 /* Make sure persistent devices do not get stuck in
1701 if (netif_running(tun->dev))
1702 netif_tx_wake_all_queues(tun->dev);
1704 strcpy(ifr->ifr_name, tun->dev->name);
1708 tun_detach_all(dev);
1710 tun_flow_uninit(tun);
1711 security_tun_dev_free_security(tun->security);
1717 static void tun_get_iff(struct net *net, struct tun_struct *tun,
1720 tun_debug(KERN_INFO, tun, "tun_get_iff\n");
1722 strcpy(ifr->ifr_name, tun->dev->name);
1724 ifr->ifr_flags = tun_flags(tun);
1728 /* This is like a cut-down ethtool ops, except done via tun fd so no
1729 * privs required. */
1730 static int set_offload(struct tun_struct *tun, unsigned long arg)
1732 netdev_features_t features = 0;
1734 if (arg & TUN_F_CSUM) {
1735 features |= NETIF_F_HW_CSUM;
1738 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1739 if (arg & TUN_F_TSO_ECN) {
1740 features |= NETIF_F_TSO_ECN;
1741 arg &= ~TUN_F_TSO_ECN;
1743 if (arg & TUN_F_TSO4)
1744 features |= NETIF_F_TSO;
1745 if (arg & TUN_F_TSO6)
1746 features |= NETIF_F_TSO6;
1747 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1751 /* This gives the user a way to test for new features in future by
1752 * trying to set them. */
1756 tun->set_features = features;
1757 netdev_update_features(tun->dev);
1762 static void tun_detach_filter(struct tun_struct *tun, int n)
1765 struct tun_file *tfile;
1767 for (i = 0; i < n; i++) {
1768 tfile = rtnl_dereference(tun->tfiles[i]);
1769 sk_detach_filter(tfile->socket.sk);
1772 tun->filter_attached = false;
1775 static int tun_attach_filter(struct tun_struct *tun)
1778 struct tun_file *tfile;
1780 for (i = 0; i < tun->numqueues; i++) {
1781 tfile = rtnl_dereference(tun->tfiles[i]);
1782 ret = sk_attach_filter(&tun->fprog, tfile->socket.sk);
1784 tun_detach_filter(tun, i);
1789 tun->filter_attached = true;
1793 static void tun_set_sndbuf(struct tun_struct *tun)
1795 struct tun_file *tfile;
1798 for (i = 0; i < tun->numqueues; i++) {
1799 tfile = rtnl_dereference(tun->tfiles[i]);
1800 tfile->socket.sk->sk_sndbuf = tun->sndbuf;
1804 static int tun_set_queue(struct file *file, struct ifreq *ifr)
1806 struct tun_file *tfile = file->private_data;
1807 struct tun_struct *tun;
1812 if (ifr->ifr_flags & IFF_ATTACH_QUEUE) {
1813 tun = tfile->detached;
1818 ret = security_tun_dev_attach_queue(tun->security);
1821 ret = tun_attach(tun, file, false);
1822 } else if (ifr->ifr_flags & IFF_DETACH_QUEUE) {
1823 tun = rtnl_dereference(tfile->tun);
1824 if (!tun || !(tun->flags & IFF_MULTI_QUEUE) || tfile->detached)
1827 __tun_detach(tfile, false);
1836 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
1837 unsigned long arg, int ifreq_len)
1839 struct tun_file *tfile = file->private_data;
1840 struct tun_struct *tun;
1841 void __user* argp = (void __user*)arg;
1847 unsigned int ifindex;
1851 if (cmd == TUNSETIFF || cmd == TUNSETQUEUE || _IOC_TYPE(cmd) == 0x89) {
1852 if (copy_from_user(&ifr, argp, ifreq_len))
1855 memset(&ifr, 0, sizeof(ifr));
1857 if (cmd == TUNGETFEATURES) {
1858 /* Currently this just means: "what IFF flags are valid?".
1859 * This is needed because we never checked for invalid flags on
1862 return put_user(IFF_TUN | IFF_TAP | TUN_FEATURES,
1863 (unsigned int __user*)argp);
1864 } else if (cmd == TUNSETQUEUE)
1865 return tun_set_queue(file, &ifr);
1870 tun = __tun_get(tfile);
1871 if (cmd == TUNSETIFF && !tun) {
1872 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1874 ret = tun_set_iff(tfile->net, file, &ifr);
1879 if (copy_to_user(argp, &ifr, ifreq_len))
1883 if (cmd == TUNSETIFINDEX) {
1889 if (copy_from_user(&ifindex, argp, sizeof(ifindex)))
1893 tfile->ifindex = ifindex;
1901 tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %u\n", cmd);
1906 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1908 if (tfile->detached)
1909 ifr.ifr_flags |= IFF_DETACH_QUEUE;
1910 if (!tfile->socket.sk->sk_filter)
1911 ifr.ifr_flags |= IFF_NOFILTER;
1913 if (copy_to_user(argp, &ifr, ifreq_len))
1918 /* Disable/Enable checksum */
1920 /* [unimplemented] */
1921 tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n",
1922 arg ? "disabled" : "enabled");
1926 /* Disable/Enable persist mode. Keep an extra reference to the
1927 * module to prevent the module being unprobed.
1929 if (arg && !(tun->flags & IFF_PERSIST)) {
1930 tun->flags |= IFF_PERSIST;
1931 __module_get(THIS_MODULE);
1933 if (!arg && (tun->flags & IFF_PERSIST)) {
1934 tun->flags &= ~IFF_PERSIST;
1935 module_put(THIS_MODULE);
1938 tun_debug(KERN_INFO, tun, "persist %s\n",
1939 arg ? "enabled" : "disabled");
1943 /* Set owner of the device */
1944 owner = make_kuid(current_user_ns(), arg);
1945 if (!uid_valid(owner)) {
1950 tun_debug(KERN_INFO, tun, "owner set to %u\n",
1951 from_kuid(&init_user_ns, tun->owner));
1955 /* Set group of the device */
1956 group = make_kgid(current_user_ns(), arg);
1957 if (!gid_valid(group)) {
1962 tun_debug(KERN_INFO, tun, "group set to %u\n",
1963 from_kgid(&init_user_ns, tun->group));
1967 /* Only allow setting the type when the interface is down */
1968 if (tun->dev->flags & IFF_UP) {
1969 tun_debug(KERN_INFO, tun,
1970 "Linktype set failed because interface is up\n");
1973 tun->dev->type = (int) arg;
1974 tun_debug(KERN_INFO, tun, "linktype set to %d\n",
1986 ret = set_offload(tun, arg);
1989 case TUNSETTXFILTER:
1990 /* Can be set only for TAPs */
1992 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
1994 ret = update_filter(&tun->txflt, (void __user *)arg);
1998 /* Get hw address */
1999 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
2000 ifr.ifr_hwaddr.sa_family = tun->dev->type;
2001 if (copy_to_user(argp, &ifr, ifreq_len))
2006 /* Set hw address */
2007 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n",
2008 ifr.ifr_hwaddr.sa_data);
2010 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
2014 sndbuf = tfile->socket.sk->sk_sndbuf;
2015 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
2020 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
2025 tun->sndbuf = sndbuf;
2026 tun_set_sndbuf(tun);
2029 case TUNGETVNETHDRSZ:
2030 vnet_hdr_sz = tun->vnet_hdr_sz;
2031 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
2035 case TUNSETVNETHDRSZ:
2036 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
2040 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
2045 tun->vnet_hdr_sz = vnet_hdr_sz;
2049 le = !!(tun->flags & TUN_VNET_LE);
2050 if (put_user(le, (int __user *)argp))
2055 if (get_user(le, (int __user *)argp)) {
2060 tun->flags |= TUN_VNET_LE;
2062 tun->flags &= ~TUN_VNET_LE;
2065 case TUNATTACHFILTER:
2066 /* Can be set only for TAPs */
2068 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
2071 if (copy_from_user(&tun->fprog, argp, sizeof(tun->fprog)))
2074 ret = tun_attach_filter(tun);
2077 case TUNDETACHFILTER:
2078 /* Can be set only for TAPs */
2080 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
2083 tun_detach_filter(tun, tun->numqueues);
2088 if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
2091 if (copy_to_user(argp, &tun->fprog, sizeof(tun->fprog)))
2108 static long tun_chr_ioctl(struct file *file,
2109 unsigned int cmd, unsigned long arg)
2111 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
2114 #ifdef CONFIG_COMPAT
2115 static long tun_chr_compat_ioctl(struct file *file,
2116 unsigned int cmd, unsigned long arg)
2121 case TUNSETTXFILTER:
2126 arg = (unsigned long)compat_ptr(arg);
2129 arg = (compat_ulong_t)arg;
2134 * compat_ifreq is shorter than ifreq, so we must not access beyond
2135 * the end of that structure. All fields that are used in this
2136 * driver are compatible though, we don't need to convert the
2139 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
2141 #endif /* CONFIG_COMPAT */
2143 static int tun_chr_fasync(int fd, struct file *file, int on)
2145 struct tun_file *tfile = file->private_data;
2148 if ((ret = fasync_helper(fd, file, on, &tfile->fasync)) < 0)
2152 __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
2153 tfile->flags |= TUN_FASYNC;
2155 tfile->flags &= ~TUN_FASYNC;
2161 static int tun_chr_open(struct inode *inode, struct file * file)
2163 struct tun_file *tfile;
2165 DBG1(KERN_INFO, "tunX: tun_chr_open\n");
2167 tfile = (struct tun_file *)sk_alloc(&init_net, AF_UNSPEC, GFP_KERNEL,
2171 RCU_INIT_POINTER(tfile->tun, NULL);
2172 tfile->net = get_net(current->nsproxy->net_ns);
2176 init_waitqueue_head(&tfile->wq.wait);
2177 RCU_INIT_POINTER(tfile->socket.wq, &tfile->wq);
2179 tfile->socket.file = file;
2180 tfile->socket.ops = &tun_socket_ops;
2182 sock_init_data(&tfile->socket, &tfile->sk);
2183 sk_change_net(&tfile->sk, tfile->net);
2185 tfile->sk.sk_write_space = tun_sock_write_space;
2186 tfile->sk.sk_sndbuf = INT_MAX;
2188 file->private_data = tfile;
2189 set_bit(SOCK_EXTERNALLY_ALLOCATED, &tfile->socket.flags);
2190 INIT_LIST_HEAD(&tfile->next);
2192 sock_set_flag(&tfile->sk, SOCK_ZEROCOPY);
2197 static int tun_chr_close(struct inode *inode, struct file *file)
2199 struct tun_file *tfile = file->private_data;
2200 struct net *net = tfile->net;
2202 tun_detach(tfile, true);
2208 #ifdef CONFIG_PROC_FS
2209 static void tun_chr_show_fdinfo(struct seq_file *m, struct file *f)
2211 struct tun_struct *tun;
2214 memset(&ifr, 0, sizeof(ifr));
2219 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
2225 seq_printf(m, "iff:\t%s\n", ifr.ifr_name);
2229 static const struct file_operations tun_fops = {
2230 .owner = THIS_MODULE,
2231 .llseek = no_llseek,
2232 .read = new_sync_read,
2233 .write = new_sync_write,
2234 .read_iter = tun_chr_read_iter,
2235 .write_iter = tun_chr_write_iter,
2236 .poll = tun_chr_poll,
2237 .unlocked_ioctl = tun_chr_ioctl,
2238 #ifdef CONFIG_COMPAT
2239 .compat_ioctl = tun_chr_compat_ioctl,
2241 .open = tun_chr_open,
2242 .release = tun_chr_close,
2243 .fasync = tun_chr_fasync,
2244 #ifdef CONFIG_PROC_FS
2245 .show_fdinfo = tun_chr_show_fdinfo,
2249 static struct miscdevice tun_miscdev = {
2252 .nodename = "net/tun",
2256 /* ethtool interface */
2258 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
2261 cmd->advertising = 0;
2262 ethtool_cmd_speed_set(cmd, SPEED_10);
2263 cmd->duplex = DUPLEX_FULL;
2264 cmd->port = PORT_TP;
2265 cmd->phy_address = 0;
2266 cmd->transceiver = XCVR_INTERNAL;
2267 cmd->autoneg = AUTONEG_DISABLE;
2273 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
2275 struct tun_struct *tun = netdev_priv(dev);
2277 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
2278 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
2280 switch (tun->flags & TUN_TYPE_MASK) {
2282 strlcpy(info->bus_info, "tun", sizeof(info->bus_info));
2285 strlcpy(info->bus_info, "tap", sizeof(info->bus_info));
2290 static u32 tun_get_msglevel(struct net_device *dev)
2293 struct tun_struct *tun = netdev_priv(dev);
2300 static void tun_set_msglevel(struct net_device *dev, u32 value)
2303 struct tun_struct *tun = netdev_priv(dev);
2308 static const struct ethtool_ops tun_ethtool_ops = {
2309 .get_settings = tun_get_settings,
2310 .get_drvinfo = tun_get_drvinfo,
2311 .get_msglevel = tun_get_msglevel,
2312 .set_msglevel = tun_set_msglevel,
2313 .get_link = ethtool_op_get_link,
2314 .get_ts_info = ethtool_op_get_ts_info,
2318 static int __init tun_init(void)
2322 pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
2323 pr_info("%s\n", DRV_COPYRIGHT);
2325 ret = rtnl_link_register(&tun_link_ops);
2327 pr_err("Can't register link_ops\n");
2331 ret = misc_register(&tun_miscdev);
2333 pr_err("Can't register misc device %d\n", TUN_MINOR);
2338 rtnl_link_unregister(&tun_link_ops);
2343 static void tun_cleanup(void)
2345 misc_deregister(&tun_miscdev);
2346 rtnl_link_unregister(&tun_link_ops);
2349 /* Get an underlying socket object from tun file. Returns error unless file is
2350 * attached to a device. The returned object works like a packet socket, it
2351 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
2352 * holding a reference to the file for as long as the socket is in use. */
2353 struct socket *tun_get_socket(struct file *file)
2355 struct tun_file *tfile;
2356 if (file->f_op != &tun_fops)
2357 return ERR_PTR(-EINVAL);
2358 tfile = file->private_data;
2360 return ERR_PTR(-EBADFD);
2361 return &tfile->socket;
2363 EXPORT_SYMBOL_GPL(tun_get_socket);
2365 module_init(tun_init);
2366 module_exit(tun_cleanup);
2367 MODULE_DESCRIPTION(DRV_DESCRIPTION);
2368 MODULE_AUTHOR(DRV_COPYRIGHT);
2369 MODULE_LICENSE("GPL");
2370 MODULE_ALIAS_MISCDEV(TUN_MINOR);
2371 MODULE_ALIAS("devname:net/tun");