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/crc32.h>
64 #include <linux/nsproxy.h>
65 #include <linux/virtio_net.h>
66 #include <linux/rcupdate.h>
67 #include <net/net_namespace.h>
68 #include <net/netns/generic.h>
69 #include <net/rtnetlink.h>
72 #include <asm/uaccess.h>
74 /* Uncomment to enable debugging */
75 /* #define TUN_DEBUG 1 */
80 #define tun_debug(level, tun, fmt, args...) \
83 netdev_printk(level, tun->dev, fmt, ##args); \
85 #define DBG1(level, fmt, args...) \
88 printk(level fmt, ##args); \
91 #define tun_debug(level, tun, fmt, args...) \
94 netdev_printk(level, tun->dev, fmt, ##args); \
96 #define DBG1(level, fmt, args...) \
99 printk(level fmt, ##args); \
103 #define GOODCOPY_LEN 128
105 #define FLT_EXACT_COUNT 8
107 unsigned int count; /* Number of addrs. Zero means disabled */
108 u32 mask[2]; /* Mask of the hashed addrs */
109 unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN];
112 /* DEFAULT_MAX_NUM_RSS_QUEUES were choosed to let the rx/tx queues allocated for
113 * the netdevice to be fit in one page. So we can make sure the success of
114 * memory allocation. TODO: increase the limit. */
115 #define MAX_TAP_QUEUES DEFAULT_MAX_NUM_RSS_QUEUES
117 #define TUN_FLOW_EXPIRE (3 * HZ)
119 /* A tun_file connects an open character device to a tuntap netdevice. It
120 * also contains all socket related strctures (except sock_fprog and tap_filter)
121 * to serve as one transmit queue for tuntap device. The sock_fprog and
122 * tap_filter were kept in tun_struct since they were used for filtering for the
123 * netdevice not for a specific queue (at least I didn't see the requirement for
127 * The tun_file and tun_struct are loosely coupled, the pointer from one to the
128 * other can only be read while rcu_read_lock or rtnl_lock is held.
132 struct socket socket;
134 struct tun_struct __rcu *tun;
136 struct fasync_struct *fasync;
137 /* only used for fasnyc */
140 struct list_head next;
141 struct tun_struct *detached;
144 struct tun_flow_entry {
145 struct hlist_node hash_link;
147 struct tun_struct *tun;
151 unsigned long updated;
154 #define TUN_NUM_FLOW_ENTRIES 1024
156 /* Since the socket were moved to tun_file, to preserve the behavior of persist
157 * device, socket filter, sndbuf and vnet header size were restore when the
158 * file were attached to a persist device.
161 struct tun_file __rcu *tfiles[MAX_TAP_QUEUES];
162 unsigned int numqueues;
167 struct net_device *dev;
168 netdev_features_t set_features;
169 #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \
170 NETIF_F_TSO6|NETIF_F_UFO)
174 struct tap_filter txflt;
175 struct sock_fprog fprog;
176 /* protected by rtnl lock */
177 bool filter_attached;
182 struct hlist_head flows[TUN_NUM_FLOW_ENTRIES];
183 struct timer_list flow_gc_timer;
184 unsigned long ageing_time;
185 unsigned int numdisabled;
186 struct list_head disabled;
190 static inline u32 tun_hashfn(u32 rxhash)
192 return rxhash & 0x3ff;
195 static struct tun_flow_entry *tun_flow_find(struct hlist_head *head, u32 rxhash)
197 struct tun_flow_entry *e;
198 struct hlist_node *n;
200 hlist_for_each_entry_rcu(e, n, head, hash_link) {
201 if (e->rxhash == rxhash)
207 static struct tun_flow_entry *tun_flow_create(struct tun_struct *tun,
208 struct hlist_head *head,
209 u32 rxhash, u16 queue_index)
211 struct tun_flow_entry *e = kmalloc(sizeof(*e), GFP_ATOMIC);
214 tun_debug(KERN_INFO, tun, "create flow: hash %u index %u\n",
215 rxhash, queue_index);
216 e->updated = jiffies;
218 e->queue_index = queue_index;
220 hlist_add_head_rcu(&e->hash_link, head);
225 static void tun_flow_delete(struct tun_struct *tun, struct tun_flow_entry *e)
227 tun_debug(KERN_INFO, tun, "delete flow: hash %u index %u\n",
228 e->rxhash, e->queue_index);
229 hlist_del_rcu(&e->hash_link);
233 static void tun_flow_flush(struct tun_struct *tun)
237 spin_lock_bh(&tun->lock);
238 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
239 struct tun_flow_entry *e;
240 struct hlist_node *h, *n;
242 hlist_for_each_entry_safe(e, h, n, &tun->flows[i], hash_link)
243 tun_flow_delete(tun, e);
245 spin_unlock_bh(&tun->lock);
248 static void tun_flow_delete_by_queue(struct tun_struct *tun, u16 queue_index)
252 spin_lock_bh(&tun->lock);
253 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
254 struct tun_flow_entry *e;
255 struct hlist_node *h, *n;
257 hlist_for_each_entry_safe(e, h, n, &tun->flows[i], hash_link) {
258 if (e->queue_index == queue_index)
259 tun_flow_delete(tun, e);
262 spin_unlock_bh(&tun->lock);
265 static void tun_flow_cleanup(unsigned long data)
267 struct tun_struct *tun = (struct tun_struct *)data;
268 unsigned long delay = tun->ageing_time;
269 unsigned long next_timer = jiffies + delay;
270 unsigned long count = 0;
273 tun_debug(KERN_INFO, tun, "tun_flow_cleanup\n");
275 spin_lock_bh(&tun->lock);
276 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
277 struct tun_flow_entry *e;
278 struct hlist_node *h, *n;
280 hlist_for_each_entry_safe(e, h, n, &tun->flows[i], hash_link) {
281 unsigned long this_timer;
283 this_timer = e->updated + delay;
284 if (time_before_eq(this_timer, jiffies))
285 tun_flow_delete(tun, e);
286 else if (time_before(this_timer, next_timer))
287 next_timer = this_timer;
292 mod_timer(&tun->flow_gc_timer, round_jiffies_up(next_timer));
293 spin_unlock_bh(&tun->lock);
296 static void tun_flow_update(struct tun_struct *tun, u32 rxhash,
299 struct hlist_head *head;
300 struct tun_flow_entry *e;
301 unsigned long delay = tun->ageing_time;
306 head = &tun->flows[tun_hashfn(rxhash)];
310 if (tun->numqueues == 1)
313 e = tun_flow_find(head, rxhash);
315 /* TODO: keep queueing to old queue until it's empty? */
316 e->queue_index = queue_index;
317 e->updated = jiffies;
319 spin_lock_bh(&tun->lock);
320 if (!tun_flow_find(head, rxhash))
321 tun_flow_create(tun, head, rxhash, queue_index);
323 if (!timer_pending(&tun->flow_gc_timer))
324 mod_timer(&tun->flow_gc_timer,
325 round_jiffies_up(jiffies + delay));
326 spin_unlock_bh(&tun->lock);
333 /* We try to identify a flow through its rxhash first. The reason that
334 * we do not check rxq no. is becuase some cards(e.g 82599), chooses
335 * the rxq based on the txq where the last packet of the flow comes. As
336 * the userspace application move between processors, we may get a
337 * different rxq no. here. If we could not get rxhash, then we would
338 * hope the rxq no. may help here.
340 static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb)
342 struct tun_struct *tun = netdev_priv(dev);
343 struct tun_flow_entry *e;
348 numqueues = tun->numqueues;
350 txq = skb_get_rxhash(skb);
352 e = tun_flow_find(&tun->flows[tun_hashfn(txq)], txq);
354 txq = e->queue_index;
356 /* use multiply and shift instead of expensive divide */
357 txq = ((u64)txq * numqueues) >> 32;
358 } else if (likely(skb_rx_queue_recorded(skb))) {
359 txq = skb_get_rx_queue(skb);
360 while (unlikely(txq >= numqueues))
368 static inline bool tun_not_capable(struct tun_struct *tun)
370 const struct cred *cred = current_cred();
371 struct net *net = dev_net(tun->dev);
373 return ((uid_valid(tun->owner) && !uid_eq(cred->euid, tun->owner)) ||
374 (gid_valid(tun->group) && !in_egroup_p(tun->group))) &&
375 !ns_capable(net->user_ns, CAP_NET_ADMIN);
378 static void tun_set_real_num_queues(struct tun_struct *tun)
380 netif_set_real_num_tx_queues(tun->dev, tun->numqueues);
381 netif_set_real_num_rx_queues(tun->dev, tun->numqueues);
384 static void tun_disable_queue(struct tun_struct *tun, struct tun_file *tfile)
386 tfile->detached = tun;
387 list_add_tail(&tfile->next, &tun->disabled);
391 static struct tun_struct *tun_enable_queue(struct tun_file *tfile)
393 struct tun_struct *tun = tfile->detached;
395 tfile->detached = NULL;
396 list_del_init(&tfile->next);
401 static void __tun_detach(struct tun_file *tfile, bool clean)
403 struct tun_file *ntfile;
404 struct tun_struct *tun;
405 struct net_device *dev;
407 tun = rtnl_dereference(tfile->tun);
410 u16 index = tfile->queue_index;
411 BUG_ON(index >= tun->numqueues);
414 rcu_assign_pointer(tun->tfiles[index],
415 tun->tfiles[tun->numqueues - 1]);
416 rcu_assign_pointer(tfile->tun, NULL);
417 ntfile = rtnl_dereference(tun->tfiles[index]);
418 ntfile->queue_index = index;
422 sock_put(&tfile->sk);
424 tun_disable_queue(tun, tfile);
427 tun_flow_delete_by_queue(tun, tun->numqueues + 1);
428 /* Drop read queue */
429 skb_queue_purge(&tfile->sk.sk_receive_queue);
430 tun_set_real_num_queues(tun);
431 } else if (tfile->detached && clean) {
432 tun = tun_enable_queue(tfile);
433 sock_put(&tfile->sk);
437 if (tun && tun->numqueues == 0 && tun->numdisabled == 0 &&
438 !(tun->flags & TUN_PERSIST))
439 if (tun->dev->reg_state == NETREG_REGISTERED)
440 unregister_netdevice(tun->dev);
442 BUG_ON(!test_bit(SOCK_EXTERNALLY_ALLOCATED,
443 &tfile->socket.flags));
444 sk_release_kernel(&tfile->sk);
448 static void tun_detach(struct tun_file *tfile, bool clean)
451 __tun_detach(tfile, clean);
455 static void tun_detach_all(struct net_device *dev)
457 struct tun_struct *tun = netdev_priv(dev);
458 struct tun_file *tfile, *tmp;
459 int i, n = tun->numqueues;
461 for (i = 0; i < n; i++) {
462 tfile = rtnl_dereference(tun->tfiles[i]);
464 wake_up_all(&tfile->wq.wait);
465 rcu_assign_pointer(tfile->tun, NULL);
468 BUG_ON(tun->numqueues != 0);
471 for (i = 0; i < n; i++) {
472 tfile = rtnl_dereference(tun->tfiles[i]);
473 /* Drop read queue */
474 skb_queue_purge(&tfile->sk.sk_receive_queue);
475 sock_put(&tfile->sk);
477 list_for_each_entry_safe(tfile, tmp, &tun->disabled, next) {
478 tun_enable_queue(tfile);
479 skb_queue_purge(&tfile->sk.sk_receive_queue);
480 sock_put(&tfile->sk);
482 BUG_ON(tun->numdisabled != 0);
484 if (tun->flags & TUN_PERSIST)
485 module_put(THIS_MODULE);
488 static int tun_attach(struct tun_struct *tun, struct file *file)
490 struct tun_file *tfile = file->private_data;
493 err = security_tun_dev_attach(tfile->socket.sk, tun->security);
498 if (rtnl_dereference(tfile->tun))
502 if (!(tun->flags & TUN_TAP_MQ) && tun->numqueues == 1)
506 if (!tfile->detached &&
507 tun->numqueues + tun->numdisabled == MAX_TAP_QUEUES)
512 /* Re-attach the filter to presist device */
513 if (tun->filter_attached == true) {
514 err = sk_attach_filter(&tun->fprog, tfile->socket.sk);
518 tfile->queue_index = tun->numqueues;
519 rcu_assign_pointer(tfile->tun, tun);
520 rcu_assign_pointer(tun->tfiles[tun->numqueues], tfile);
524 tun_enable_queue(tfile);
526 sock_hold(&tfile->sk);
528 tun_set_real_num_queues(tun);
530 /* device is allowed to go away first, so no need to hold extra
538 static struct tun_struct *__tun_get(struct tun_file *tfile)
540 struct tun_struct *tun;
543 tun = rcu_dereference(tfile->tun);
551 static struct tun_struct *tun_get(struct file *file)
553 return __tun_get(file->private_data);
556 static void tun_put(struct tun_struct *tun)
562 static void addr_hash_set(u32 *mask, const u8 *addr)
564 int n = ether_crc(ETH_ALEN, addr) >> 26;
565 mask[n >> 5] |= (1 << (n & 31));
568 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
570 int n = ether_crc(ETH_ALEN, addr) >> 26;
571 return mask[n >> 5] & (1 << (n & 31));
574 static int update_filter(struct tap_filter *filter, void __user *arg)
576 struct { u8 u[ETH_ALEN]; } *addr;
577 struct tun_filter uf;
578 int err, alen, n, nexact;
580 if (copy_from_user(&uf, arg, sizeof(uf)))
589 alen = ETH_ALEN * uf.count;
590 addr = kmalloc(alen, GFP_KERNEL);
594 if (copy_from_user(addr, arg + sizeof(uf), alen)) {
599 /* The filter is updated without holding any locks. Which is
600 * perfectly safe. We disable it first and in the worst
601 * case we'll accept a few undesired packets. */
605 /* Use first set of addresses as an exact filter */
606 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
607 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
611 /* Remaining multicast addresses are hashed,
612 * unicast will leave the filter disabled. */
613 memset(filter->mask, 0, sizeof(filter->mask));
614 for (; n < uf.count; n++) {
615 if (!is_multicast_ether_addr(addr[n].u)) {
616 err = 0; /* no filter */
619 addr_hash_set(filter->mask, addr[n].u);
622 /* For ALLMULTI just set the mask to all ones.
623 * This overrides the mask populated above. */
624 if ((uf.flags & TUN_FLT_ALLMULTI))
625 memset(filter->mask, ~0, sizeof(filter->mask));
627 /* Now enable the filter */
629 filter->count = nexact;
631 /* Return the number of exact filters */
639 /* Returns: 0 - drop, !=0 - accept */
640 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
642 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
644 struct ethhdr *eh = (struct ethhdr *) skb->data;
648 for (i = 0; i < filter->count; i++)
649 if (ether_addr_equal(eh->h_dest, filter->addr[i]))
652 /* Inexact match (multicast only) */
653 if (is_multicast_ether_addr(eh->h_dest))
654 return addr_hash_test(filter->mask, eh->h_dest);
660 * Checks whether the packet is accepted or not.
661 * Returns: 0 - drop, !=0 - accept
663 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
668 return run_filter(filter, skb);
671 /* Network device part of the driver */
673 static const struct ethtool_ops tun_ethtool_ops;
675 /* Net device detach from fd. */
676 static void tun_net_uninit(struct net_device *dev)
681 /* Net device open. */
682 static int tun_net_open(struct net_device *dev)
684 netif_tx_start_all_queues(dev);
688 /* Net device close. */
689 static int tun_net_close(struct net_device *dev)
691 netif_tx_stop_all_queues(dev);
695 /* Net device start xmit */
696 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
698 struct tun_struct *tun = netdev_priv(dev);
699 int txq = skb->queue_mapping;
700 struct tun_file *tfile;
703 tfile = rcu_dereference(tun->tfiles[txq]);
705 /* Drop packet if interface is not attached */
706 if (txq >= tun->numqueues)
709 tun_debug(KERN_INFO, tun, "tun_net_xmit %d\n", skb->len);
713 /* Drop if the filter does not like it.
714 * This is a noop if the filter is disabled.
715 * Filter can be enabled only for the TAP devices. */
716 if (!check_filter(&tun->txflt, skb))
719 if (tfile->socket.sk->sk_filter &&
720 sk_filter(tfile->socket.sk, skb))
723 /* Limit the number of packets queued by dividing txq length with the
726 if (skb_queue_len(&tfile->socket.sk->sk_receive_queue)
727 >= dev->tx_queue_len / tun->numqueues)
730 /* Orphan the skb - required as we might hang on to it
731 * for indefinite time. */
732 if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
737 skb_queue_tail(&tfile->socket.sk->sk_receive_queue, skb);
739 /* Notify and wake up reader process */
740 if (tfile->flags & TUN_FASYNC)
741 kill_fasync(&tfile->fasync, SIGIO, POLL_IN);
742 wake_up_interruptible_poll(&tfile->wq.wait, POLLIN |
743 POLLRDNORM | POLLRDBAND);
749 dev->stats.tx_dropped++;
756 static void tun_net_mclist(struct net_device *dev)
759 * This callback is supposed to deal with mc filter in
760 * _rx_ path and has nothing to do with the _tx_ path.
761 * In rx path we always accept everything userspace gives us.
766 #define MAX_MTU 65535
769 tun_net_change_mtu(struct net_device *dev, int new_mtu)
771 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
777 static netdev_features_t tun_net_fix_features(struct net_device *dev,
778 netdev_features_t features)
780 struct tun_struct *tun = netdev_priv(dev);
782 return (features & tun->set_features) | (features & ~TUN_USER_FEATURES);
784 #ifdef CONFIG_NET_POLL_CONTROLLER
785 static void tun_poll_controller(struct net_device *dev)
788 * Tun only receives frames when:
789 * 1) the char device endpoint gets data from user space
790 * 2) the tun socket gets a sendmsg call from user space
791 * Since both of those are syncronous operations, we are guaranteed
792 * never to have pending data when we poll for it
793 * so theres nothing to do here but return.
794 * We need this though so netpoll recognizes us as an interface that
795 * supports polling, which enables bridge devices in virt setups to
796 * still use netconsole
801 static const struct net_device_ops tun_netdev_ops = {
802 .ndo_uninit = tun_net_uninit,
803 .ndo_open = tun_net_open,
804 .ndo_stop = tun_net_close,
805 .ndo_start_xmit = tun_net_xmit,
806 .ndo_change_mtu = tun_net_change_mtu,
807 .ndo_fix_features = tun_net_fix_features,
808 .ndo_select_queue = tun_select_queue,
809 #ifdef CONFIG_NET_POLL_CONTROLLER
810 .ndo_poll_controller = tun_poll_controller,
814 static const struct net_device_ops tap_netdev_ops = {
815 .ndo_uninit = tun_net_uninit,
816 .ndo_open = tun_net_open,
817 .ndo_stop = tun_net_close,
818 .ndo_start_xmit = tun_net_xmit,
819 .ndo_change_mtu = tun_net_change_mtu,
820 .ndo_fix_features = tun_net_fix_features,
821 .ndo_set_rx_mode = tun_net_mclist,
822 .ndo_set_mac_address = eth_mac_addr,
823 .ndo_validate_addr = eth_validate_addr,
824 .ndo_select_queue = tun_select_queue,
825 #ifdef CONFIG_NET_POLL_CONTROLLER
826 .ndo_poll_controller = tun_poll_controller,
830 static int tun_flow_init(struct tun_struct *tun)
834 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++)
835 INIT_HLIST_HEAD(&tun->flows[i]);
837 tun->ageing_time = TUN_FLOW_EXPIRE;
838 setup_timer(&tun->flow_gc_timer, tun_flow_cleanup, (unsigned long)tun);
839 mod_timer(&tun->flow_gc_timer,
840 round_jiffies_up(jiffies + tun->ageing_time));
845 static void tun_flow_uninit(struct tun_struct *tun)
847 del_timer_sync(&tun->flow_gc_timer);
851 /* Initialize net device. */
852 static void tun_net_init(struct net_device *dev)
854 struct tun_struct *tun = netdev_priv(dev);
856 switch (tun->flags & TUN_TYPE_MASK) {
858 dev->netdev_ops = &tun_netdev_ops;
860 /* Point-to-Point TUN Device */
861 dev->hard_header_len = 0;
865 /* Zero header length */
866 dev->type = ARPHRD_NONE;
867 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
868 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
872 dev->netdev_ops = &tap_netdev_ops;
873 /* Ethernet TAP Device */
875 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
876 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
878 eth_hw_addr_random(dev);
880 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
885 /* Character device part */
888 static unsigned int tun_chr_poll(struct file *file, poll_table *wait)
890 struct tun_file *tfile = file->private_data;
891 struct tun_struct *tun = __tun_get(tfile);
893 unsigned int mask = 0;
898 sk = tfile->socket.sk;
900 tun_debug(KERN_INFO, tun, "tun_chr_poll\n");
902 poll_wait(file, &tfile->wq.wait, wait);
904 if (!skb_queue_empty(&sk->sk_receive_queue))
905 mask |= POLLIN | POLLRDNORM;
907 if (sock_writeable(sk) ||
908 (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
910 mask |= POLLOUT | POLLWRNORM;
912 if (tun->dev->reg_state != NETREG_REGISTERED)
919 /* prepad is the amount to reserve at front. len is length after that.
920 * linear is a hint as to how much to copy (usually headers). */
921 static struct sk_buff *tun_alloc_skb(struct tun_file *tfile,
922 size_t prepad, size_t len,
923 size_t linear, int noblock)
925 struct sock *sk = tfile->socket.sk;
929 /* Under a page? Don't bother with paged skb. */
930 if (prepad + len < PAGE_SIZE || !linear)
933 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
938 skb_reserve(skb, prepad);
939 skb_put(skb, linear);
940 skb->data_len = len - linear;
941 skb->len += len - linear;
946 /* set skb frags from iovec, this can move to core network code for reuse */
947 static int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *from,
948 int offset, size_t count)
950 int len = iov_length(from, count) - offset;
951 int copy = skb_headlen(skb);
952 int size, offset1 = 0;
955 /* Skip over from offset */
956 while (count && (offset >= from->iov_len)) {
957 offset -= from->iov_len;
962 /* copy up to skb headlen */
963 while (count && (copy > 0)) {
964 size = min_t(unsigned int, copy, from->iov_len - offset);
965 if (copy_from_user(skb->data + offset1, from->iov_base + offset,
982 struct page *page[MAX_SKB_FRAGS];
985 unsigned long truesize;
987 len = from->iov_len - offset;
993 base = (unsigned long)from->iov_base + offset;
994 size = ((base & ~PAGE_MASK) + len + ~PAGE_MASK) >> PAGE_SHIFT;
995 if (i + size > MAX_SKB_FRAGS)
997 num_pages = get_user_pages_fast(base, size, 0, &page[i]);
998 if (num_pages != size) {
999 for (i = 0; i < num_pages; i++)
1003 truesize = size * PAGE_SIZE;
1004 skb->data_len += len;
1006 skb->truesize += truesize;
1007 atomic_add(truesize, &skb->sk->sk_wmem_alloc);
1009 int off = base & ~PAGE_MASK;
1010 int size = min_t(int, len, PAGE_SIZE - off);
1011 __skb_fill_page_desc(skb, i, page[i], off, size);
1012 skb_shinfo(skb)->nr_frags++;
1013 /* increase sk_wmem_alloc */
1024 /* Get packet from user space buffer */
1025 static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
1026 void *msg_control, const struct iovec *iv,
1027 size_t total_len, size_t count, int noblock)
1029 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
1030 struct sk_buff *skb;
1031 size_t len = total_len, align = NET_SKB_PAD;
1032 struct virtio_net_hdr gso = { 0 };
1035 bool zerocopy = false;
1039 if (!(tun->flags & TUN_NO_PI)) {
1040 if ((len -= sizeof(pi)) > total_len)
1043 if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
1045 offset += sizeof(pi);
1048 if (tun->flags & TUN_VNET_HDR) {
1049 if ((len -= tun->vnet_hdr_sz) > total_len)
1052 if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
1055 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
1056 gso.csum_start + gso.csum_offset + 2 > gso.hdr_len)
1057 gso.hdr_len = gso.csum_start + gso.csum_offset + 2;
1059 if (gso.hdr_len > len)
1061 offset += tun->vnet_hdr_sz;
1064 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
1065 align += NET_IP_ALIGN;
1066 if (unlikely(len < ETH_HLEN ||
1067 (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
1075 /* Userspace may produce vectors with count greater than
1076 * MAX_SKB_FRAGS, so we need to linearize parts of the skb
1077 * to let the rest of data to be fit in the frags.
1079 if (count > MAX_SKB_FRAGS) {
1080 copylen = iov_length(iv, count - MAX_SKB_FRAGS);
1081 if (copylen < offset)
1087 /* There are 256 bytes to be copied in skb, so there is enough
1088 * room for skb expand head in case it is used.
1089 * The rest of the buffer is mapped from userspace.
1091 if (copylen < gso.hdr_len)
1092 copylen = gso.hdr_len;
1094 copylen = GOODCOPY_LEN;
1098 skb = tun_alloc_skb(tfile, align, copylen, gso.hdr_len, noblock);
1100 if (PTR_ERR(skb) != -EAGAIN)
1101 tun->dev->stats.rx_dropped++;
1102 return PTR_ERR(skb);
1106 err = zerocopy_sg_from_iovec(skb, iv, offset, count);
1108 err = skb_copy_datagram_from_iovec(skb, 0, iv, offset, len);
1111 tun->dev->stats.rx_dropped++;
1116 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
1117 if (!skb_partial_csum_set(skb, gso.csum_start,
1119 tun->dev->stats.rx_frame_errors++;
1125 switch (tun->flags & TUN_TYPE_MASK) {
1127 if (tun->flags & TUN_NO_PI) {
1128 switch (skb->data[0] & 0xf0) {
1130 pi.proto = htons(ETH_P_IP);
1133 pi.proto = htons(ETH_P_IPV6);
1136 tun->dev->stats.rx_dropped++;
1142 skb_reset_mac_header(skb);
1143 skb->protocol = pi.proto;
1144 skb->dev = tun->dev;
1147 skb->protocol = eth_type_trans(skb, tun->dev);
1151 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
1153 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
1154 case VIRTIO_NET_HDR_GSO_TCPV4:
1155 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
1157 case VIRTIO_NET_HDR_GSO_TCPV6:
1158 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
1160 case VIRTIO_NET_HDR_GSO_UDP:
1161 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
1164 tun->dev->stats.rx_frame_errors++;
1169 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
1170 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
1172 skb_shinfo(skb)->gso_size = gso.gso_size;
1173 if (skb_shinfo(skb)->gso_size == 0) {
1174 tun->dev->stats.rx_frame_errors++;
1179 /* Header must be checked, and gso_segs computed. */
1180 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
1181 skb_shinfo(skb)->gso_segs = 0;
1184 /* copy skb_ubuf_info for callback when skb has no error */
1186 skb_shinfo(skb)->destructor_arg = msg_control;
1187 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
1190 skb_reset_network_header(skb);
1191 rxhash = skb_get_rxhash(skb);
1194 tun->dev->stats.rx_packets++;
1195 tun->dev->stats.rx_bytes += len;
1197 tun_flow_update(tun, rxhash, tfile->queue_index);
1201 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
1202 unsigned long count, loff_t pos)
1204 struct file *file = iocb->ki_filp;
1205 struct tun_struct *tun = tun_get(file);
1206 struct tun_file *tfile = file->private_data;
1212 tun_debug(KERN_INFO, tun, "tun_chr_write %ld\n", count);
1214 result = tun_get_user(tun, tfile, NULL, iv, iov_length(iv, count),
1215 count, file->f_flags & O_NONBLOCK);
1221 /* Put packet to the user space buffer */
1222 static ssize_t tun_put_user(struct tun_struct *tun,
1223 struct tun_file *tfile,
1224 struct sk_buff *skb,
1225 const struct iovec *iv, int len)
1227 struct tun_pi pi = { 0, skb->protocol };
1230 if (!(tun->flags & TUN_NO_PI)) {
1231 if ((len -= sizeof(pi)) < 0)
1234 if (len < skb->len) {
1235 /* Packet will be striped */
1236 pi.flags |= TUN_PKT_STRIP;
1239 if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi)))
1241 total += sizeof(pi);
1244 if (tun->flags & TUN_VNET_HDR) {
1245 struct virtio_net_hdr gso = { 0 }; /* no info leak */
1246 if ((len -= tun->vnet_hdr_sz) < 0)
1249 if (skb_is_gso(skb)) {
1250 struct skb_shared_info *sinfo = skb_shinfo(skb);
1252 /* This is a hint as to how much should be linear. */
1253 gso.hdr_len = skb_headlen(skb);
1254 gso.gso_size = sinfo->gso_size;
1255 if (sinfo->gso_type & SKB_GSO_TCPV4)
1256 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
1257 else if (sinfo->gso_type & SKB_GSO_TCPV6)
1258 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
1259 else if (sinfo->gso_type & SKB_GSO_UDP)
1260 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
1262 pr_err("unexpected GSO type: "
1263 "0x%x, gso_size %d, hdr_len %d\n",
1264 sinfo->gso_type, gso.gso_size,
1266 print_hex_dump(KERN_ERR, "tun: ",
1269 min((int)gso.hdr_len, 64), true);
1273 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
1274 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
1276 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
1278 if (skb->ip_summed == CHECKSUM_PARTIAL) {
1279 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
1280 gso.csum_start = skb_checksum_start_offset(skb);
1281 gso.csum_offset = skb->csum_offset;
1282 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
1283 gso.flags = VIRTIO_NET_HDR_F_DATA_VALID;
1284 } /* else everything is zero */
1286 if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
1289 total += tun->vnet_hdr_sz;
1292 len = min_t(int, skb->len, len);
1294 skb_copy_datagram_const_iovec(skb, 0, iv, total, len);
1297 tun->dev->stats.tx_packets++;
1298 tun->dev->stats.tx_bytes += len;
1303 static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
1304 struct kiocb *iocb, const struct iovec *iv,
1305 ssize_t len, int noblock)
1307 DECLARE_WAITQUEUE(wait, current);
1308 struct sk_buff *skb;
1311 tun_debug(KERN_INFO, tun, "tun_do_read\n");
1313 if (unlikely(!noblock))
1314 add_wait_queue(&tfile->wq.wait, &wait);
1316 current->state = TASK_INTERRUPTIBLE;
1318 /* Read frames from the queue */
1319 if (!(skb = skb_dequeue(&tfile->socket.sk->sk_receive_queue))) {
1324 if (signal_pending(current)) {
1328 if (tun->dev->reg_state != NETREG_REGISTERED) {
1333 /* Nothing to read, let's sleep */
1338 ret = tun_put_user(tun, tfile, skb, iv, len);
1343 current->state = TASK_RUNNING;
1344 if (unlikely(!noblock))
1345 remove_wait_queue(&tfile->wq.wait, &wait);
1350 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
1351 unsigned long count, loff_t pos)
1353 struct file *file = iocb->ki_filp;
1354 struct tun_file *tfile = file->private_data;
1355 struct tun_struct *tun = __tun_get(tfile);
1360 len = iov_length(iv, count);
1366 ret = tun_do_read(tun, tfile, iocb, iv, len,
1367 file->f_flags & O_NONBLOCK);
1368 ret = min_t(ssize_t, ret, len);
1374 static void tun_free_netdev(struct net_device *dev)
1376 struct tun_struct *tun = netdev_priv(dev);
1378 BUG_ON(!(list_empty(&tun->disabled)));
1379 tun_flow_uninit(tun);
1380 security_tun_dev_free_security(tun->security);
1384 static void tun_setup(struct net_device *dev)
1386 struct tun_struct *tun = netdev_priv(dev);
1388 tun->owner = INVALID_UID;
1389 tun->group = INVALID_GID;
1391 dev->ethtool_ops = &tun_ethtool_ops;
1392 dev->destructor = tun_free_netdev;
1395 /* Trivial set of netlink ops to allow deleting tun or tap
1396 * device with netlink.
1398 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
1403 static struct rtnl_link_ops tun_link_ops __read_mostly = {
1405 .priv_size = sizeof(struct tun_struct),
1407 .validate = tun_validate,
1410 static void tun_sock_write_space(struct sock *sk)
1412 struct tun_file *tfile;
1413 wait_queue_head_t *wqueue;
1415 if (!sock_writeable(sk))
1418 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
1421 wqueue = sk_sleep(sk);
1422 if (wqueue && waitqueue_active(wqueue))
1423 wake_up_interruptible_sync_poll(wqueue, POLLOUT |
1424 POLLWRNORM | POLLWRBAND);
1426 tfile = container_of(sk, struct tun_file, sk);
1427 kill_fasync(&tfile->fasync, SIGIO, POLL_OUT);
1430 static int tun_sendmsg(struct kiocb *iocb, struct socket *sock,
1431 struct msghdr *m, size_t total_len)
1434 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1435 struct tun_struct *tun = __tun_get(tfile);
1439 ret = tun_get_user(tun, tfile, m->msg_control, m->msg_iov, total_len,
1440 m->msg_iovlen, m->msg_flags & MSG_DONTWAIT);
1446 static int tun_recvmsg(struct kiocb *iocb, struct socket *sock,
1447 struct msghdr *m, size_t total_len,
1450 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1451 struct tun_struct *tun = __tun_get(tfile);
1457 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC))
1459 ret = tun_do_read(tun, tfile, iocb, m->msg_iov, total_len,
1460 flags & MSG_DONTWAIT);
1461 if (ret > total_len) {
1462 m->msg_flags |= MSG_TRUNC;
1463 ret = flags & MSG_TRUNC ? ret : total_len;
1469 static int tun_release(struct socket *sock)
1476 /* Ops structure to mimic raw sockets with tun */
1477 static const struct proto_ops tun_socket_ops = {
1478 .sendmsg = tun_sendmsg,
1479 .recvmsg = tun_recvmsg,
1480 .release = tun_release,
1483 static struct proto tun_proto = {
1485 .owner = THIS_MODULE,
1486 .obj_size = sizeof(struct tun_file),
1489 static int tun_flags(struct tun_struct *tun)
1493 if (tun->flags & TUN_TUN_DEV)
1498 if (tun->flags & TUN_NO_PI)
1501 /* This flag has no real effect. We track the value for backwards
1504 if (tun->flags & TUN_ONE_QUEUE)
1505 flags |= IFF_ONE_QUEUE;
1507 if (tun->flags & TUN_VNET_HDR)
1508 flags |= IFF_VNET_HDR;
1510 if (tun->flags & TUN_TAP_MQ)
1511 flags |= IFF_MULTI_QUEUE;
1516 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
1519 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1520 return sprintf(buf, "0x%x\n", tun_flags(tun));
1523 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
1526 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1527 return uid_valid(tun->owner)?
1528 sprintf(buf, "%u\n",
1529 from_kuid_munged(current_user_ns(), tun->owner)):
1530 sprintf(buf, "-1\n");
1533 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
1536 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1537 return gid_valid(tun->group) ?
1538 sprintf(buf, "%u\n",
1539 from_kgid_munged(current_user_ns(), tun->group)):
1540 sprintf(buf, "-1\n");
1543 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
1544 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
1545 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
1547 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
1549 struct tun_struct *tun;
1550 struct tun_file *tfile = file->private_data;
1551 struct net_device *dev;
1554 if (tfile->detached)
1557 dev = __dev_get_by_name(net, ifr->ifr_name);
1559 if (ifr->ifr_flags & IFF_TUN_EXCL)
1561 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
1562 tun = netdev_priv(dev);
1563 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
1564 tun = netdev_priv(dev);
1568 if (tun_not_capable(tun))
1570 err = security_tun_dev_open(tun->security);
1574 err = tun_attach(tun, file);
1578 if (tun->flags & TUN_TAP_MQ &&
1579 (tun->numqueues + tun->numdisabled > 1))
1584 unsigned long flags = 0;
1585 int queues = ifr->ifr_flags & IFF_MULTI_QUEUE ?
1588 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1590 err = security_tun_dev_create();
1595 if (ifr->ifr_flags & IFF_TUN) {
1597 flags |= TUN_TUN_DEV;
1599 } else if (ifr->ifr_flags & IFF_TAP) {
1601 flags |= TUN_TAP_DEV;
1607 name = ifr->ifr_name;
1609 dev = alloc_netdev_mqs(sizeof(struct tun_struct), name,
1610 tun_setup, queues, queues);
1615 dev_net_set(dev, net);
1616 dev->rtnl_link_ops = &tun_link_ops;
1618 tun = netdev_priv(dev);
1621 tun->txflt.count = 0;
1622 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
1624 tun->filter_attached = false;
1625 tun->sndbuf = tfile->socket.sk->sk_sndbuf;
1627 spin_lock_init(&tun->lock);
1629 err = security_tun_dev_alloc_security(&tun->security);
1635 err = tun_flow_init(tun);
1639 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
1641 dev->features = dev->hw_features;
1643 INIT_LIST_HEAD(&tun->disabled);
1644 err = tun_attach(tun, file);
1648 err = register_netdevice(tun->dev);
1652 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
1653 device_create_file(&tun->dev->dev, &dev_attr_owner) ||
1654 device_create_file(&tun->dev->dev, &dev_attr_group))
1655 pr_err("Failed to create tun sysfs files\n");
1657 netif_carrier_on(tun->dev);
1660 tun_debug(KERN_INFO, tun, "tun_set_iff\n");
1662 if (ifr->ifr_flags & IFF_NO_PI)
1663 tun->flags |= TUN_NO_PI;
1665 tun->flags &= ~TUN_NO_PI;
1667 /* This flag has no real effect. We track the value for backwards
1670 if (ifr->ifr_flags & IFF_ONE_QUEUE)
1671 tun->flags |= TUN_ONE_QUEUE;
1673 tun->flags &= ~TUN_ONE_QUEUE;
1675 if (ifr->ifr_flags & IFF_VNET_HDR)
1676 tun->flags |= TUN_VNET_HDR;
1678 tun->flags &= ~TUN_VNET_HDR;
1680 if (ifr->ifr_flags & IFF_MULTI_QUEUE)
1681 tun->flags |= TUN_TAP_MQ;
1683 tun->flags &= ~TUN_TAP_MQ;
1685 /* Make sure persistent devices do not get stuck in
1688 if (netif_running(tun->dev))
1689 netif_tx_wake_all_queues(tun->dev);
1691 strcpy(ifr->ifr_name, tun->dev->name);
1699 static void tun_get_iff(struct net *net, struct tun_struct *tun,
1702 tun_debug(KERN_INFO, tun, "tun_get_iff\n");
1704 strcpy(ifr->ifr_name, tun->dev->name);
1706 ifr->ifr_flags = tun_flags(tun);
1710 /* This is like a cut-down ethtool ops, except done via tun fd so no
1711 * privs required. */
1712 static int set_offload(struct tun_struct *tun, unsigned long arg)
1714 netdev_features_t features = 0;
1716 if (arg & TUN_F_CSUM) {
1717 features |= NETIF_F_HW_CSUM;
1720 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1721 if (arg & TUN_F_TSO_ECN) {
1722 features |= NETIF_F_TSO_ECN;
1723 arg &= ~TUN_F_TSO_ECN;
1725 if (arg & TUN_F_TSO4)
1726 features |= NETIF_F_TSO;
1727 if (arg & TUN_F_TSO6)
1728 features |= NETIF_F_TSO6;
1729 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1732 if (arg & TUN_F_UFO) {
1733 features |= NETIF_F_UFO;
1738 /* This gives the user a way to test for new features in future by
1739 * trying to set them. */
1743 tun->set_features = features;
1744 netdev_update_features(tun->dev);
1749 static void tun_detach_filter(struct tun_struct *tun, int n)
1752 struct tun_file *tfile;
1754 for (i = 0; i < n; i++) {
1755 tfile = rtnl_dereference(tun->tfiles[i]);
1756 sk_detach_filter(tfile->socket.sk);
1759 tun->filter_attached = false;
1762 static int tun_attach_filter(struct tun_struct *tun)
1765 struct tun_file *tfile;
1767 for (i = 0; i < tun->numqueues; i++) {
1768 tfile = rtnl_dereference(tun->tfiles[i]);
1769 ret = sk_attach_filter(&tun->fprog, tfile->socket.sk);
1771 tun_detach_filter(tun, i);
1776 tun->filter_attached = true;
1780 static void tun_set_sndbuf(struct tun_struct *tun)
1782 struct tun_file *tfile;
1785 for (i = 0; i < tun->numqueues; i++) {
1786 tfile = rtnl_dereference(tun->tfiles[i]);
1787 tfile->socket.sk->sk_sndbuf = tun->sndbuf;
1791 static int tun_set_queue(struct file *file, struct ifreq *ifr)
1793 struct tun_file *tfile = file->private_data;
1794 struct tun_struct *tun;
1799 if (ifr->ifr_flags & IFF_ATTACH_QUEUE) {
1800 tun = tfile->detached;
1805 ret = security_tun_dev_attach_queue(tun->security);
1808 ret = tun_attach(tun, file);
1809 } else if (ifr->ifr_flags & IFF_DETACH_QUEUE) {
1810 tun = rtnl_dereference(tfile->tun);
1811 if (!tun || !(tun->flags & TUN_TAP_MQ))
1814 __tun_detach(tfile, false);
1823 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
1824 unsigned long arg, int ifreq_len)
1826 struct tun_file *tfile = file->private_data;
1827 struct tun_struct *tun;
1828 void __user* argp = (void __user*)arg;
1836 if (cmd == TUNSETIFF || cmd == TUNSETQUEUE || _IOC_TYPE(cmd) == 0x89) {
1837 if (copy_from_user(&ifr, argp, ifreq_len))
1840 memset(&ifr, 0, sizeof(ifr));
1842 if (cmd == TUNGETFEATURES) {
1843 /* Currently this just means: "what IFF flags are valid?".
1844 * This is needed because we never checked for invalid flags on
1846 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
1847 IFF_VNET_HDR | IFF_MULTI_QUEUE,
1848 (unsigned int __user*)argp);
1849 } else if (cmd == TUNSETQUEUE)
1850 return tun_set_queue(file, &ifr);
1855 tun = __tun_get(tfile);
1856 if (cmd == TUNSETIFF && !tun) {
1857 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1859 ret = tun_set_iff(tfile->net, file, &ifr);
1864 if (copy_to_user(argp, &ifr, ifreq_len))
1873 tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %u\n", cmd);
1878 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1880 if (copy_to_user(argp, &ifr, ifreq_len))
1885 /* Disable/Enable checksum */
1887 /* [unimplemented] */
1888 tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n",
1889 arg ? "disabled" : "enabled");
1893 /* Disable/Enable persist mode. Keep an extra reference to the
1894 * module to prevent the module being unprobed.
1896 if (arg && !(tun->flags & TUN_PERSIST)) {
1897 tun->flags |= TUN_PERSIST;
1898 __module_get(THIS_MODULE);
1900 if (!arg && (tun->flags & TUN_PERSIST)) {
1901 tun->flags &= ~TUN_PERSIST;
1902 module_put(THIS_MODULE);
1905 tun_debug(KERN_INFO, tun, "persist %s\n",
1906 arg ? "enabled" : "disabled");
1910 /* Set owner of the device */
1911 owner = make_kuid(current_user_ns(), arg);
1912 if (!uid_valid(owner)) {
1917 tun_debug(KERN_INFO, tun, "owner set to %u\n",
1918 from_kuid(&init_user_ns, tun->owner));
1922 /* Set group of the device */
1923 group = make_kgid(current_user_ns(), arg);
1924 if (!gid_valid(group)) {
1929 tun_debug(KERN_INFO, tun, "group set to %u\n",
1930 from_kgid(&init_user_ns, tun->group));
1934 /* Only allow setting the type when the interface is down */
1935 if (tun->dev->flags & IFF_UP) {
1936 tun_debug(KERN_INFO, tun,
1937 "Linktype set failed because interface is up\n");
1940 tun->dev->type = (int) arg;
1941 tun_debug(KERN_INFO, tun, "linktype set to %d\n",
1953 ret = set_offload(tun, arg);
1956 case TUNSETTXFILTER:
1957 /* Can be set only for TAPs */
1959 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1961 ret = update_filter(&tun->txflt, (void __user *)arg);
1965 /* Get hw address */
1966 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
1967 ifr.ifr_hwaddr.sa_family = tun->dev->type;
1968 if (copy_to_user(argp, &ifr, ifreq_len))
1973 /* Set hw address */
1974 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n",
1975 ifr.ifr_hwaddr.sa_data);
1977 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
1981 sndbuf = tfile->socket.sk->sk_sndbuf;
1982 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
1987 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
1992 tun->sndbuf = sndbuf;
1993 tun_set_sndbuf(tun);
1996 case TUNGETVNETHDRSZ:
1997 vnet_hdr_sz = tun->vnet_hdr_sz;
1998 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
2002 case TUNSETVNETHDRSZ:
2003 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
2007 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
2012 tun->vnet_hdr_sz = vnet_hdr_sz;
2015 case TUNATTACHFILTER:
2016 /* Can be set only for TAPs */
2018 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
2021 if (copy_from_user(&tun->fprog, argp, sizeof(tun->fprog)))
2024 ret = tun_attach_filter(tun);
2027 case TUNDETACHFILTER:
2028 /* Can be set only for TAPs */
2030 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
2033 tun_detach_filter(tun, tun->numqueues);
2048 static long tun_chr_ioctl(struct file *file,
2049 unsigned int cmd, unsigned long arg)
2051 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
2054 #ifdef CONFIG_COMPAT
2055 static long tun_chr_compat_ioctl(struct file *file,
2056 unsigned int cmd, unsigned long arg)
2061 case TUNSETTXFILTER:
2066 arg = (unsigned long)compat_ptr(arg);
2069 arg = (compat_ulong_t)arg;
2074 * compat_ifreq is shorter than ifreq, so we must not access beyond
2075 * the end of that structure. All fields that are used in this
2076 * driver are compatible though, we don't need to convert the
2079 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
2081 #endif /* CONFIG_COMPAT */
2083 static int tun_chr_fasync(int fd, struct file *file, int on)
2085 struct tun_file *tfile = file->private_data;
2088 if ((ret = fasync_helper(fd, file, on, &tfile->fasync)) < 0)
2092 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
2095 tfile->flags |= TUN_FASYNC;
2097 tfile->flags &= ~TUN_FASYNC;
2103 static int tun_chr_open(struct inode *inode, struct file * file)
2105 struct tun_file *tfile;
2107 DBG1(KERN_INFO, "tunX: tun_chr_open\n");
2109 tfile = (struct tun_file *)sk_alloc(&init_net, AF_UNSPEC, GFP_KERNEL,
2113 rcu_assign_pointer(tfile->tun, NULL);
2114 tfile->net = get_net(current->nsproxy->net_ns);
2117 rcu_assign_pointer(tfile->socket.wq, &tfile->wq);
2118 init_waitqueue_head(&tfile->wq.wait);
2120 tfile->socket.file = file;
2121 tfile->socket.ops = &tun_socket_ops;
2123 sock_init_data(&tfile->socket, &tfile->sk);
2124 sk_change_net(&tfile->sk, tfile->net);
2126 tfile->sk.sk_write_space = tun_sock_write_space;
2127 tfile->sk.sk_sndbuf = INT_MAX;
2129 file->private_data = tfile;
2130 set_bit(SOCK_EXTERNALLY_ALLOCATED, &tfile->socket.flags);
2131 INIT_LIST_HEAD(&tfile->next);
2136 static int tun_chr_close(struct inode *inode, struct file *file)
2138 struct tun_file *tfile = file->private_data;
2139 struct net *net = tfile->net;
2141 tun_detach(tfile, true);
2147 static const struct file_operations tun_fops = {
2148 .owner = THIS_MODULE,
2149 .llseek = no_llseek,
2150 .read = do_sync_read,
2151 .aio_read = tun_chr_aio_read,
2152 .write = do_sync_write,
2153 .aio_write = tun_chr_aio_write,
2154 .poll = tun_chr_poll,
2155 .unlocked_ioctl = tun_chr_ioctl,
2156 #ifdef CONFIG_COMPAT
2157 .compat_ioctl = tun_chr_compat_ioctl,
2159 .open = tun_chr_open,
2160 .release = tun_chr_close,
2161 .fasync = tun_chr_fasync
2164 static struct miscdevice tun_miscdev = {
2167 .nodename = "net/tun",
2171 /* ethtool interface */
2173 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
2176 cmd->advertising = 0;
2177 ethtool_cmd_speed_set(cmd, SPEED_10);
2178 cmd->duplex = DUPLEX_FULL;
2179 cmd->port = PORT_TP;
2180 cmd->phy_address = 0;
2181 cmd->transceiver = XCVR_INTERNAL;
2182 cmd->autoneg = AUTONEG_DISABLE;
2188 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
2190 struct tun_struct *tun = netdev_priv(dev);
2192 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
2193 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
2195 switch (tun->flags & TUN_TYPE_MASK) {
2197 strlcpy(info->bus_info, "tun", sizeof(info->bus_info));
2200 strlcpy(info->bus_info, "tap", sizeof(info->bus_info));
2205 static u32 tun_get_msglevel(struct net_device *dev)
2208 struct tun_struct *tun = netdev_priv(dev);
2215 static void tun_set_msglevel(struct net_device *dev, u32 value)
2218 struct tun_struct *tun = netdev_priv(dev);
2223 static const struct ethtool_ops tun_ethtool_ops = {
2224 .get_settings = tun_get_settings,
2225 .get_drvinfo = tun_get_drvinfo,
2226 .get_msglevel = tun_get_msglevel,
2227 .set_msglevel = tun_set_msglevel,
2228 .get_link = ethtool_op_get_link,
2232 static int __init tun_init(void)
2236 pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
2237 pr_info("%s\n", DRV_COPYRIGHT);
2239 ret = rtnl_link_register(&tun_link_ops);
2241 pr_err("Can't register link_ops\n");
2245 ret = misc_register(&tun_miscdev);
2247 pr_err("Can't register misc device %d\n", TUN_MINOR);
2252 rtnl_link_unregister(&tun_link_ops);
2257 static void tun_cleanup(void)
2259 misc_deregister(&tun_miscdev);
2260 rtnl_link_unregister(&tun_link_ops);
2263 /* Get an underlying socket object from tun file. Returns error unless file is
2264 * attached to a device. The returned object works like a packet socket, it
2265 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
2266 * holding a reference to the file for as long as the socket is in use. */
2267 struct socket *tun_get_socket(struct file *file)
2269 struct tun_file *tfile;
2270 if (file->f_op != &tun_fops)
2271 return ERR_PTR(-EINVAL);
2272 tfile = file->private_data;
2274 return ERR_PTR(-EBADFD);
2275 return &tfile->socket;
2277 EXPORT_SYMBOL_GPL(tun_get_socket);
2279 module_init(tun_init);
2280 module_exit(tun_cleanup);
2281 MODULE_DESCRIPTION(DRV_DESCRIPTION);
2282 MODULE_AUTHOR(DRV_COPYRIGHT);
2283 MODULE_LICENSE("GPL");
2284 MODULE_ALIAS_MISCDEV(TUN_MINOR);
2285 MODULE_ALIAS("devname:net/tun");