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 /* 1024 is probably a high enough limit: modern hypervisors seem to support on
113 * the order of 100-200 CPUs so this leaves us some breathing space if we want
114 * to match a queue per guest CPU.
116 #define MAX_TAP_QUEUES 1024
118 #define TUN_FLOW_EXPIRE (3 * HZ)
120 /* A tun_file connects an open character device to a tuntap netdevice. It
121 * also contains all socket related strctures (except sock_fprog and tap_filter)
122 * to serve as one transmit queue for tuntap device. The sock_fprog and
123 * tap_filter were kept in tun_struct since they were used for filtering for the
124 * netdevice not for a specific queue (at least I didn't see the requirement for
128 * The tun_file and tun_struct are loosely coupled, the pointer from one to the
129 * other can only be read while rcu_read_lock or rtnl_lock is held.
133 struct socket socket;
135 struct tun_struct __rcu *tun;
137 struct fasync_struct *fasync;
138 /* only used for fasnyc */
141 struct list_head next;
142 struct tun_struct *detached;
145 struct tun_flow_entry {
146 struct hlist_node hash_link;
148 struct tun_struct *tun;
152 unsigned long updated;
155 #define TUN_NUM_FLOW_ENTRIES 1024
157 /* Since the socket were moved to tun_file, to preserve the behavior of persist
158 * device, socket filter, sndbuf and vnet header size were restore when the
159 * file were attached to a persist device.
162 struct tun_file __rcu *tfiles[MAX_TAP_QUEUES];
163 unsigned int numqueues;
168 struct net_device *dev;
169 netdev_features_t set_features;
170 #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \
171 NETIF_F_TSO6|NETIF_F_UFO)
175 struct tap_filter txflt;
176 struct sock_fprog fprog;
177 /* protected by rtnl lock */
178 bool filter_attached;
183 struct kmem_cache *flow_cache;
184 struct hlist_head flows[TUN_NUM_FLOW_ENTRIES];
185 struct timer_list flow_gc_timer;
186 unsigned long ageing_time;
187 unsigned int numdisabled;
188 struct list_head disabled;
191 static inline u32 tun_hashfn(u32 rxhash)
193 return rxhash & 0x3ff;
196 static struct tun_flow_entry *tun_flow_find(struct hlist_head *head, u32 rxhash)
198 struct tun_flow_entry *e;
199 struct hlist_node *n;
201 hlist_for_each_entry_rcu(e, n, head, hash_link) {
202 if (e->rxhash == rxhash)
208 static struct tun_flow_entry *tun_flow_create(struct tun_struct *tun,
209 struct hlist_head *head,
210 u32 rxhash, u16 queue_index)
212 struct tun_flow_entry *e = kmem_cache_alloc(tun->flow_cache,
215 tun_debug(KERN_INFO, tun, "create flow: hash %u index %u\n",
216 rxhash, queue_index);
217 e->updated = jiffies;
219 e->queue_index = queue_index;
221 hlist_add_head_rcu(&e->hash_link, head);
226 static void tun_flow_free(struct rcu_head *head)
228 struct tun_flow_entry *e
229 = container_of(head, struct tun_flow_entry, rcu);
230 kmem_cache_free(e->tun->flow_cache, e);
233 static void tun_flow_delete(struct tun_struct *tun, struct tun_flow_entry *e)
235 tun_debug(KERN_INFO, tun, "delete flow: hash %u index %u\n",
236 e->rxhash, e->queue_index);
237 hlist_del_rcu(&e->hash_link);
238 call_rcu(&e->rcu, tun_flow_free);
241 static void tun_flow_flush(struct tun_struct *tun)
245 spin_lock_bh(&tun->lock);
246 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
247 struct tun_flow_entry *e;
248 struct hlist_node *h, *n;
250 hlist_for_each_entry_safe(e, h, n, &tun->flows[i], hash_link)
251 tun_flow_delete(tun, e);
253 spin_unlock_bh(&tun->lock);
256 static void tun_flow_delete_by_queue(struct tun_struct *tun, u16 queue_index)
260 spin_lock_bh(&tun->lock);
261 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
262 struct tun_flow_entry *e;
263 struct hlist_node *h, *n;
265 hlist_for_each_entry_safe(e, h, n, &tun->flows[i], hash_link) {
266 if (e->queue_index == queue_index)
267 tun_flow_delete(tun, e);
270 spin_unlock_bh(&tun->lock);
273 static void tun_flow_cleanup(unsigned long data)
275 struct tun_struct *tun = (struct tun_struct *)data;
276 unsigned long delay = tun->ageing_time;
277 unsigned long next_timer = jiffies + delay;
278 unsigned long count = 0;
281 tun_debug(KERN_INFO, tun, "tun_flow_cleanup\n");
283 spin_lock_bh(&tun->lock);
284 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
285 struct tun_flow_entry *e;
286 struct hlist_node *h, *n;
288 hlist_for_each_entry_safe(e, h, n, &tun->flows[i], hash_link) {
289 unsigned long this_timer;
291 this_timer = e->updated + delay;
292 if (time_before_eq(this_timer, jiffies))
293 tun_flow_delete(tun, e);
294 else if (time_before(this_timer, next_timer))
295 next_timer = this_timer;
300 mod_timer(&tun->flow_gc_timer, round_jiffies_up(next_timer));
301 spin_unlock_bh(&tun->lock);
304 static void tun_flow_update(struct tun_struct *tun, u32 rxhash,
307 struct hlist_head *head;
308 struct tun_flow_entry *e;
309 unsigned long delay = tun->ageing_time;
314 head = &tun->flows[tun_hashfn(rxhash)];
318 if (tun->numqueues == 1)
321 e = tun_flow_find(head, rxhash);
323 /* TODO: keep queueing to old queue until it's empty? */
324 e->queue_index = queue_index;
325 e->updated = jiffies;
327 spin_lock_bh(&tun->lock);
328 if (!tun_flow_find(head, rxhash))
329 tun_flow_create(tun, head, rxhash, queue_index);
331 if (!timer_pending(&tun->flow_gc_timer))
332 mod_timer(&tun->flow_gc_timer,
333 round_jiffies_up(jiffies + delay));
334 spin_unlock_bh(&tun->lock);
341 /* We try to identify a flow through its rxhash first. The reason that
342 * we do not check rxq no. is becuase some cards(e.g 82599), chooses
343 * the rxq based on the txq where the last packet of the flow comes. As
344 * the userspace application move between processors, we may get a
345 * different rxq no. here. If we could not get rxhash, then we would
346 * hope the rxq no. may help here.
348 static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb)
350 struct tun_struct *tun = netdev_priv(dev);
351 struct tun_flow_entry *e;
356 numqueues = tun->numqueues;
358 txq = skb_get_rxhash(skb);
360 e = tun_flow_find(&tun->flows[tun_hashfn(txq)], txq);
362 txq = e->queue_index;
364 /* use multiply and shift instead of expensive divide */
365 txq = ((u64)txq * numqueues) >> 32;
366 } else if (likely(skb_rx_queue_recorded(skb))) {
367 txq = skb_get_rx_queue(skb);
368 while (unlikely(txq >= numqueues))
376 static inline bool tun_not_capable(struct tun_struct *tun)
378 const struct cred *cred = current_cred();
379 struct net *net = dev_net(tun->dev);
381 return ((uid_valid(tun->owner) && !uid_eq(cred->euid, tun->owner)) ||
382 (gid_valid(tun->group) && !in_egroup_p(tun->group))) &&
383 !ns_capable(net->user_ns, CAP_NET_ADMIN);
386 static void tun_set_real_num_queues(struct tun_struct *tun)
388 netif_set_real_num_tx_queues(tun->dev, tun->numqueues);
389 netif_set_real_num_rx_queues(tun->dev, tun->numqueues);
392 static void tun_disable_queue(struct tun_struct *tun, struct tun_file *tfile)
394 tfile->detached = tun;
395 list_add_tail(&tfile->next, &tun->disabled);
399 static struct tun_struct *tun_enable_queue(struct tun_file *tfile)
401 struct tun_struct *tun = tfile->detached;
403 tfile->detached = NULL;
404 list_del_init(&tfile->next);
409 static void __tun_detach(struct tun_file *tfile, bool clean)
411 struct tun_file *ntfile;
412 struct tun_struct *tun;
413 struct net_device *dev;
415 tun = rcu_dereference_protected(tfile->tun,
416 lockdep_rtnl_is_held());
418 u16 index = tfile->queue_index;
419 BUG_ON(index >= tun->numqueues);
422 rcu_assign_pointer(tun->tfiles[index],
423 tun->tfiles[tun->numqueues - 1]);
424 rcu_assign_pointer(tfile->tun, NULL);
425 ntfile = rcu_dereference_protected(tun->tfiles[index],
426 lockdep_rtnl_is_held());
427 ntfile->queue_index = index;
431 sock_put(&tfile->sk);
433 tun_disable_queue(tun, tfile);
436 tun_flow_delete_by_queue(tun, tun->numqueues + 1);
437 /* Drop read queue */
438 skb_queue_purge(&tfile->sk.sk_receive_queue);
439 tun_set_real_num_queues(tun);
440 } else if (tfile->detached && clean)
441 tun = tun_enable_queue(tfile);
444 if (tun && tun->numqueues == 0 && tun->numdisabled == 0 &&
445 !(tun->flags & TUN_PERSIST))
446 if (tun->dev->reg_state == NETREG_REGISTERED)
447 unregister_netdevice(tun->dev);
449 BUG_ON(!test_bit(SOCK_EXTERNALLY_ALLOCATED,
450 &tfile->socket.flags));
451 sk_release_kernel(&tfile->sk);
455 static void tun_detach(struct tun_file *tfile, bool clean)
458 __tun_detach(tfile, clean);
462 static void tun_detach_all(struct net_device *dev)
464 struct tun_struct *tun = netdev_priv(dev);
465 struct tun_file *tfile, *tmp;
466 int i, n = tun->numqueues;
468 for (i = 0; i < n; i++) {
469 tfile = rcu_dereference_protected(tun->tfiles[i],
470 lockdep_rtnl_is_held());
472 wake_up_all(&tfile->wq.wait);
473 rcu_assign_pointer(tfile->tun, NULL);
476 BUG_ON(tun->numqueues != 0);
479 for (i = 0; i < n; i++) {
480 tfile = rcu_dereference_protected(tun->tfiles[i],
481 lockdep_rtnl_is_held());
482 /* Drop read queue */
483 skb_queue_purge(&tfile->sk.sk_receive_queue);
484 sock_put(&tfile->sk);
486 list_for_each_entry_safe(tfile, tmp, &tun->disabled, next) {
487 tun_enable_queue(tfile);
488 skb_queue_purge(&tfile->sk.sk_receive_queue);
489 sock_put(&tfile->sk);
491 BUG_ON(tun->numdisabled != 0);
494 static int tun_attach(struct tun_struct *tun, struct file *file)
496 struct tun_file *tfile = file->private_data;
500 if (rcu_dereference_protected(tfile->tun, lockdep_rtnl_is_held()))
504 if (!(tun->flags & TUN_TAP_MQ) && tun->numqueues == 1)
508 if (!tfile->detached &&
509 tun->numqueues + tun->numdisabled == MAX_TAP_QUEUES)
514 /* Re-attach the filter to presist device */
515 if (tun->filter_attached == true) {
516 err = sk_attach_filter(&tun->fprog, tfile->socket.sk);
520 tfile->queue_index = tun->numqueues;
521 rcu_assign_pointer(tfile->tun, tun);
522 rcu_assign_pointer(tun->tfiles[tun->numqueues], tfile);
526 tun_enable_queue(tfile);
528 sock_hold(&tfile->sk);
530 tun_set_real_num_queues(tun);
532 /* device is allowed to go away first, so no need to hold extra
540 static struct tun_struct *__tun_get(struct tun_file *tfile)
542 struct tun_struct *tun;
545 tun = rcu_dereference(tfile->tun);
553 static struct tun_struct *tun_get(struct file *file)
555 return __tun_get(file->private_data);
558 static void tun_put(struct tun_struct *tun)
564 static void addr_hash_set(u32 *mask, const u8 *addr)
566 int n = ether_crc(ETH_ALEN, addr) >> 26;
567 mask[n >> 5] |= (1 << (n & 31));
570 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
572 int n = ether_crc(ETH_ALEN, addr) >> 26;
573 return mask[n >> 5] & (1 << (n & 31));
576 static int update_filter(struct tap_filter *filter, void __user *arg)
578 struct { u8 u[ETH_ALEN]; } *addr;
579 struct tun_filter uf;
580 int err, alen, n, nexact;
582 if (copy_from_user(&uf, arg, sizeof(uf)))
591 alen = ETH_ALEN * uf.count;
592 addr = kmalloc(alen, GFP_KERNEL);
596 if (copy_from_user(addr, arg + sizeof(uf), alen)) {
601 /* The filter is updated without holding any locks. Which is
602 * perfectly safe. We disable it first and in the worst
603 * case we'll accept a few undesired packets. */
607 /* Use first set of addresses as an exact filter */
608 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
609 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
613 /* Remaining multicast addresses are hashed,
614 * unicast will leave the filter disabled. */
615 memset(filter->mask, 0, sizeof(filter->mask));
616 for (; n < uf.count; n++) {
617 if (!is_multicast_ether_addr(addr[n].u)) {
618 err = 0; /* no filter */
621 addr_hash_set(filter->mask, addr[n].u);
624 /* For ALLMULTI just set the mask to all ones.
625 * This overrides the mask populated above. */
626 if ((uf.flags & TUN_FLT_ALLMULTI))
627 memset(filter->mask, ~0, sizeof(filter->mask));
629 /* Now enable the filter */
631 filter->count = nexact;
633 /* Return the number of exact filters */
641 /* Returns: 0 - drop, !=0 - accept */
642 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
644 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
646 struct ethhdr *eh = (struct ethhdr *) skb->data;
650 for (i = 0; i < filter->count; i++)
651 if (ether_addr_equal(eh->h_dest, filter->addr[i]))
654 /* Inexact match (multicast only) */
655 if (is_multicast_ether_addr(eh->h_dest))
656 return addr_hash_test(filter->mask, eh->h_dest);
662 * Checks whether the packet is accepted or not.
663 * Returns: 0 - drop, !=0 - accept
665 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
670 return run_filter(filter, skb);
673 /* Network device part of the driver */
675 static const struct ethtool_ops tun_ethtool_ops;
677 /* Net device detach from fd. */
678 static void tun_net_uninit(struct net_device *dev)
683 /* Net device open. */
684 static int tun_net_open(struct net_device *dev)
686 netif_tx_start_all_queues(dev);
690 /* Net device close. */
691 static int tun_net_close(struct net_device *dev)
693 netif_tx_stop_all_queues(dev);
697 /* Net device start xmit */
698 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
700 struct tun_struct *tun = netdev_priv(dev);
701 int txq = skb->queue_mapping;
702 struct tun_file *tfile;
705 tfile = rcu_dereference(tun->tfiles[txq]);
707 /* Drop packet if interface is not attached */
708 if (txq >= tun->numqueues)
711 tun_debug(KERN_INFO, tun, "tun_net_xmit %d\n", skb->len);
715 /* Drop if the filter does not like it.
716 * This is a noop if the filter is disabled.
717 * Filter can be enabled only for the TAP devices. */
718 if (!check_filter(&tun->txflt, skb))
721 if (tfile->socket.sk->sk_filter &&
722 sk_filter(tfile->socket.sk, skb))
725 /* Limit the number of packets queued by dividing txq length with the
728 if (skb_queue_len(&tfile->socket.sk->sk_receive_queue)
729 >= dev->tx_queue_len / tun->numqueues)
732 /* Orphan the skb - required as we might hang on to it
733 * for indefinite time. */
734 if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
739 skb_queue_tail(&tfile->socket.sk->sk_receive_queue, skb);
741 /* Notify and wake up reader process */
742 if (tfile->flags & TUN_FASYNC)
743 kill_fasync(&tfile->fasync, SIGIO, POLL_IN);
744 wake_up_interruptible_poll(&tfile->wq.wait, POLLIN |
745 POLLRDNORM | POLLRDBAND);
751 dev->stats.tx_dropped++;
758 static void tun_net_mclist(struct net_device *dev)
761 * This callback is supposed to deal with mc filter in
762 * _rx_ path and has nothing to do with the _tx_ path.
763 * In rx path we always accept everything userspace gives us.
768 #define MAX_MTU 65535
771 tun_net_change_mtu(struct net_device *dev, int new_mtu)
773 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
779 static netdev_features_t tun_net_fix_features(struct net_device *dev,
780 netdev_features_t features)
782 struct tun_struct *tun = netdev_priv(dev);
784 return (features & tun->set_features) | (features & ~TUN_USER_FEATURES);
786 #ifdef CONFIG_NET_POLL_CONTROLLER
787 static void tun_poll_controller(struct net_device *dev)
790 * Tun only receives frames when:
791 * 1) the char device endpoint gets data from user space
792 * 2) the tun socket gets a sendmsg call from user space
793 * Since both of those are syncronous operations, we are guaranteed
794 * never to have pending data when we poll for it
795 * so theres nothing to do here but return.
796 * We need this though so netpoll recognizes us as an interface that
797 * supports polling, which enables bridge devices in virt setups to
798 * still use netconsole
803 static const struct net_device_ops tun_netdev_ops = {
804 .ndo_uninit = tun_net_uninit,
805 .ndo_open = tun_net_open,
806 .ndo_stop = tun_net_close,
807 .ndo_start_xmit = tun_net_xmit,
808 .ndo_change_mtu = tun_net_change_mtu,
809 .ndo_fix_features = tun_net_fix_features,
810 .ndo_select_queue = tun_select_queue,
811 #ifdef CONFIG_NET_POLL_CONTROLLER
812 .ndo_poll_controller = tun_poll_controller,
816 static const struct net_device_ops tap_netdev_ops = {
817 .ndo_uninit = tun_net_uninit,
818 .ndo_open = tun_net_open,
819 .ndo_stop = tun_net_close,
820 .ndo_start_xmit = tun_net_xmit,
821 .ndo_change_mtu = tun_net_change_mtu,
822 .ndo_fix_features = tun_net_fix_features,
823 .ndo_set_rx_mode = tun_net_mclist,
824 .ndo_set_mac_address = eth_mac_addr,
825 .ndo_validate_addr = eth_validate_addr,
826 .ndo_select_queue = tun_select_queue,
827 #ifdef CONFIG_NET_POLL_CONTROLLER
828 .ndo_poll_controller = tun_poll_controller,
832 static int tun_flow_init(struct tun_struct *tun)
836 tun->flow_cache = kmem_cache_create("tun_flow_cache",
837 sizeof(struct tun_flow_entry), 0, 0,
839 if (!tun->flow_cache)
842 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++)
843 INIT_HLIST_HEAD(&tun->flows[i]);
845 tun->ageing_time = TUN_FLOW_EXPIRE;
846 setup_timer(&tun->flow_gc_timer, tun_flow_cleanup, (unsigned long)tun);
847 mod_timer(&tun->flow_gc_timer,
848 round_jiffies_up(jiffies + tun->ageing_time));
853 static void tun_flow_uninit(struct tun_struct *tun)
855 del_timer_sync(&tun->flow_gc_timer);
858 /* Wait for completion of call_rcu()'s */
860 kmem_cache_destroy(tun->flow_cache);
863 /* Initialize net device. */
864 static void tun_net_init(struct net_device *dev)
866 struct tun_struct *tun = netdev_priv(dev);
868 switch (tun->flags & TUN_TYPE_MASK) {
870 dev->netdev_ops = &tun_netdev_ops;
872 /* Point-to-Point TUN Device */
873 dev->hard_header_len = 0;
877 /* Zero header length */
878 dev->type = ARPHRD_NONE;
879 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
880 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
884 dev->netdev_ops = &tap_netdev_ops;
885 /* Ethernet TAP Device */
887 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
888 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
890 eth_hw_addr_random(dev);
892 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
897 /* Character device part */
900 static unsigned int tun_chr_poll(struct file *file, poll_table *wait)
902 struct tun_file *tfile = file->private_data;
903 struct tun_struct *tun = __tun_get(tfile);
905 unsigned int mask = 0;
910 sk = tfile->socket.sk;
912 tun_debug(KERN_INFO, tun, "tun_chr_poll\n");
914 poll_wait(file, &tfile->wq.wait, wait);
916 if (!skb_queue_empty(&sk->sk_receive_queue))
917 mask |= POLLIN | POLLRDNORM;
919 if (sock_writeable(sk) ||
920 (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
922 mask |= POLLOUT | POLLWRNORM;
924 if (tun->dev->reg_state != NETREG_REGISTERED)
931 /* prepad is the amount to reserve at front. len is length after that.
932 * linear is a hint as to how much to copy (usually headers). */
933 static struct sk_buff *tun_alloc_skb(struct tun_file *tfile,
934 size_t prepad, size_t len,
935 size_t linear, int noblock)
937 struct sock *sk = tfile->socket.sk;
941 /* Under a page? Don't bother with paged skb. */
942 if (prepad + len < PAGE_SIZE || !linear)
945 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
950 skb_reserve(skb, prepad);
951 skb_put(skb, linear);
952 skb->data_len = len - linear;
953 skb->len += len - linear;
958 /* set skb frags from iovec, this can move to core network code for reuse */
959 static int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *from,
960 int offset, size_t count)
962 int len = iov_length(from, count) - offset;
963 int copy = skb_headlen(skb);
964 int size, offset1 = 0;
967 /* Skip over from offset */
968 while (count && (offset >= from->iov_len)) {
969 offset -= from->iov_len;
974 /* copy up to skb headlen */
975 while (count && (copy > 0)) {
976 size = min_t(unsigned int, copy, from->iov_len - offset);
977 if (copy_from_user(skb->data + offset1, from->iov_base + offset,
994 struct page *page[MAX_SKB_FRAGS];
997 unsigned long truesize;
999 len = from->iov_len - offset;
1005 base = (unsigned long)from->iov_base + offset;
1006 size = ((base & ~PAGE_MASK) + len + ~PAGE_MASK) >> PAGE_SHIFT;
1007 if (i + size > MAX_SKB_FRAGS)
1009 num_pages = get_user_pages_fast(base, size, 0, &page[i]);
1010 if (num_pages != size) {
1011 for (i = 0; i < num_pages; i++)
1015 truesize = size * PAGE_SIZE;
1016 skb->data_len += len;
1018 skb->truesize += truesize;
1019 atomic_add(truesize, &skb->sk->sk_wmem_alloc);
1021 int off = base & ~PAGE_MASK;
1022 int size = min_t(int, len, PAGE_SIZE - off);
1023 __skb_fill_page_desc(skb, i, page[i], off, size);
1024 skb_shinfo(skb)->nr_frags++;
1025 /* increase sk_wmem_alloc */
1036 /* Get packet from user space buffer */
1037 static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
1038 void *msg_control, const struct iovec *iv,
1039 size_t total_len, size_t count, int noblock)
1041 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
1042 struct sk_buff *skb;
1043 size_t len = total_len, align = NET_SKB_PAD;
1044 struct virtio_net_hdr gso = { 0 };
1047 bool zerocopy = false;
1051 if (!(tun->flags & TUN_NO_PI)) {
1052 if ((len -= sizeof(pi)) > total_len)
1055 if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
1057 offset += sizeof(pi);
1060 if (tun->flags & TUN_VNET_HDR) {
1061 if ((len -= tun->vnet_hdr_sz) > total_len)
1064 if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
1067 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
1068 gso.csum_start + gso.csum_offset + 2 > gso.hdr_len)
1069 gso.hdr_len = gso.csum_start + gso.csum_offset + 2;
1071 if (gso.hdr_len > len)
1073 offset += tun->vnet_hdr_sz;
1076 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
1077 align += NET_IP_ALIGN;
1078 if (unlikely(len < ETH_HLEN ||
1079 (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
1087 /* Userspace may produce vectors with count greater than
1088 * MAX_SKB_FRAGS, so we need to linearize parts of the skb
1089 * to let the rest of data to be fit in the frags.
1091 if (count > MAX_SKB_FRAGS) {
1092 copylen = iov_length(iv, count - MAX_SKB_FRAGS);
1093 if (copylen < offset)
1099 /* There are 256 bytes to be copied in skb, so there is enough
1100 * room for skb expand head in case it is used.
1101 * The rest of the buffer is mapped from userspace.
1103 if (copylen < gso.hdr_len)
1104 copylen = gso.hdr_len;
1106 copylen = GOODCOPY_LEN;
1110 skb = tun_alloc_skb(tfile, align, copylen, gso.hdr_len, noblock);
1112 if (PTR_ERR(skb) != -EAGAIN)
1113 tun->dev->stats.rx_dropped++;
1114 return PTR_ERR(skb);
1118 err = zerocopy_sg_from_iovec(skb, iv, offset, count);
1120 err = skb_copy_datagram_from_iovec(skb, 0, iv, offset, len);
1123 tun->dev->stats.rx_dropped++;
1128 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
1129 if (!skb_partial_csum_set(skb, gso.csum_start,
1131 tun->dev->stats.rx_frame_errors++;
1137 switch (tun->flags & TUN_TYPE_MASK) {
1139 if (tun->flags & TUN_NO_PI) {
1140 switch (skb->data[0] & 0xf0) {
1142 pi.proto = htons(ETH_P_IP);
1145 pi.proto = htons(ETH_P_IPV6);
1148 tun->dev->stats.rx_dropped++;
1154 skb_reset_mac_header(skb);
1155 skb->protocol = pi.proto;
1156 skb->dev = tun->dev;
1159 skb->protocol = eth_type_trans(skb, tun->dev);
1163 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
1165 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
1166 case VIRTIO_NET_HDR_GSO_TCPV4:
1167 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
1169 case VIRTIO_NET_HDR_GSO_TCPV6:
1170 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
1172 case VIRTIO_NET_HDR_GSO_UDP:
1173 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
1176 tun->dev->stats.rx_frame_errors++;
1181 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
1182 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
1184 skb_shinfo(skb)->gso_size = gso.gso_size;
1185 if (skb_shinfo(skb)->gso_size == 0) {
1186 tun->dev->stats.rx_frame_errors++;
1191 /* Header must be checked, and gso_segs computed. */
1192 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
1193 skb_shinfo(skb)->gso_segs = 0;
1196 /* copy skb_ubuf_info for callback when skb has no error */
1198 skb_shinfo(skb)->destructor_arg = msg_control;
1199 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
1202 skb_reset_network_header(skb);
1203 rxhash = skb_get_rxhash(skb);
1206 tun->dev->stats.rx_packets++;
1207 tun->dev->stats.rx_bytes += len;
1209 tun_flow_update(tun, rxhash, tfile->queue_index);
1213 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
1214 unsigned long count, loff_t pos)
1216 struct file *file = iocb->ki_filp;
1217 struct tun_struct *tun = tun_get(file);
1218 struct tun_file *tfile = file->private_data;
1224 tun_debug(KERN_INFO, tun, "tun_chr_write %ld\n", count);
1226 result = tun_get_user(tun, tfile, NULL, iv, iov_length(iv, count),
1227 count, file->f_flags & O_NONBLOCK);
1233 /* Put packet to the user space buffer */
1234 static ssize_t tun_put_user(struct tun_struct *tun,
1235 struct tun_file *tfile,
1236 struct sk_buff *skb,
1237 const struct iovec *iv, int len)
1239 struct tun_pi pi = { 0, skb->protocol };
1242 if (!(tun->flags & TUN_NO_PI)) {
1243 if ((len -= sizeof(pi)) < 0)
1246 if (len < skb->len) {
1247 /* Packet will be striped */
1248 pi.flags |= TUN_PKT_STRIP;
1251 if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi)))
1253 total += sizeof(pi);
1256 if (tun->flags & TUN_VNET_HDR) {
1257 struct virtio_net_hdr gso = { 0 }; /* no info leak */
1258 if ((len -= tun->vnet_hdr_sz) < 0)
1261 if (skb_is_gso(skb)) {
1262 struct skb_shared_info *sinfo = skb_shinfo(skb);
1264 /* This is a hint as to how much should be linear. */
1265 gso.hdr_len = skb_headlen(skb);
1266 gso.gso_size = sinfo->gso_size;
1267 if (sinfo->gso_type & SKB_GSO_TCPV4)
1268 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
1269 else if (sinfo->gso_type & SKB_GSO_TCPV6)
1270 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
1271 else if (sinfo->gso_type & SKB_GSO_UDP)
1272 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
1274 pr_err("unexpected GSO type: "
1275 "0x%x, gso_size %d, hdr_len %d\n",
1276 sinfo->gso_type, gso.gso_size,
1278 print_hex_dump(KERN_ERR, "tun: ",
1281 min((int)gso.hdr_len, 64), true);
1285 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
1286 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
1288 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
1290 if (skb->ip_summed == CHECKSUM_PARTIAL) {
1291 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
1292 gso.csum_start = skb_checksum_start_offset(skb);
1293 gso.csum_offset = skb->csum_offset;
1294 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
1295 gso.flags = VIRTIO_NET_HDR_F_DATA_VALID;
1296 } /* else everything is zero */
1298 if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
1301 total += tun->vnet_hdr_sz;
1304 len = min_t(int, skb->len, len);
1306 skb_copy_datagram_const_iovec(skb, 0, iv, total, len);
1309 tun->dev->stats.tx_packets++;
1310 tun->dev->stats.tx_bytes += len;
1315 static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
1316 struct kiocb *iocb, const struct iovec *iv,
1317 ssize_t len, int noblock)
1319 DECLARE_WAITQUEUE(wait, current);
1320 struct sk_buff *skb;
1323 tun_debug(KERN_INFO, tun, "tun_do_read\n");
1325 if (unlikely(!noblock))
1326 add_wait_queue(&tfile->wq.wait, &wait);
1328 current->state = TASK_INTERRUPTIBLE;
1330 /* Read frames from the queue */
1331 if (!(skb = skb_dequeue(&tfile->socket.sk->sk_receive_queue))) {
1336 if (signal_pending(current)) {
1340 if (tun->dev->reg_state != NETREG_REGISTERED) {
1345 /* Nothing to read, let's sleep */
1350 ret = tun_put_user(tun, tfile, skb, iv, len);
1355 current->state = TASK_RUNNING;
1356 if (unlikely(!noblock))
1357 remove_wait_queue(&tfile->wq.wait, &wait);
1362 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
1363 unsigned long count, loff_t pos)
1365 struct file *file = iocb->ki_filp;
1366 struct tun_file *tfile = file->private_data;
1367 struct tun_struct *tun = __tun_get(tfile);
1372 len = iov_length(iv, count);
1378 ret = tun_do_read(tun, tfile, iocb, iv, len,
1379 file->f_flags & O_NONBLOCK);
1380 ret = min_t(ssize_t, ret, len);
1386 static void tun_free_netdev(struct net_device *dev)
1388 struct tun_struct *tun = netdev_priv(dev);
1390 BUG_ON(!(list_empty(&tun->disabled)));
1391 tun_flow_uninit(tun);
1395 static void tun_setup(struct net_device *dev)
1397 struct tun_struct *tun = netdev_priv(dev);
1399 tun->owner = INVALID_UID;
1400 tun->group = INVALID_GID;
1402 dev->ethtool_ops = &tun_ethtool_ops;
1403 dev->destructor = tun_free_netdev;
1406 /* Trivial set of netlink ops to allow deleting tun or tap
1407 * device with netlink.
1409 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
1414 static struct rtnl_link_ops tun_link_ops __read_mostly = {
1416 .priv_size = sizeof(struct tun_struct),
1418 .validate = tun_validate,
1421 static void tun_sock_write_space(struct sock *sk)
1423 struct tun_file *tfile;
1424 wait_queue_head_t *wqueue;
1426 if (!sock_writeable(sk))
1429 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
1432 wqueue = sk_sleep(sk);
1433 if (wqueue && waitqueue_active(wqueue))
1434 wake_up_interruptible_sync_poll(wqueue, POLLOUT |
1435 POLLWRNORM | POLLWRBAND);
1437 tfile = container_of(sk, struct tun_file, sk);
1438 kill_fasync(&tfile->fasync, SIGIO, POLL_OUT);
1441 static int tun_sendmsg(struct kiocb *iocb, struct socket *sock,
1442 struct msghdr *m, size_t total_len)
1445 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1446 struct tun_struct *tun = __tun_get(tfile);
1450 ret = tun_get_user(tun, tfile, m->msg_control, m->msg_iov, total_len,
1451 m->msg_iovlen, m->msg_flags & MSG_DONTWAIT);
1457 static int tun_recvmsg(struct kiocb *iocb, struct socket *sock,
1458 struct msghdr *m, size_t total_len,
1461 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1462 struct tun_struct *tun = __tun_get(tfile);
1468 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC))
1470 ret = tun_do_read(tun, tfile, iocb, m->msg_iov, total_len,
1471 flags & MSG_DONTWAIT);
1472 if (ret > total_len) {
1473 m->msg_flags |= MSG_TRUNC;
1474 ret = flags & MSG_TRUNC ? ret : total_len;
1480 static int tun_release(struct socket *sock)
1487 /* Ops structure to mimic raw sockets with tun */
1488 static const struct proto_ops tun_socket_ops = {
1489 .sendmsg = tun_sendmsg,
1490 .recvmsg = tun_recvmsg,
1491 .release = tun_release,
1494 static struct proto tun_proto = {
1496 .owner = THIS_MODULE,
1497 .obj_size = sizeof(struct tun_file),
1500 static int tun_flags(struct tun_struct *tun)
1504 if (tun->flags & TUN_TUN_DEV)
1509 if (tun->flags & TUN_NO_PI)
1512 /* This flag has no real effect. We track the value for backwards
1515 if (tun->flags & TUN_ONE_QUEUE)
1516 flags |= IFF_ONE_QUEUE;
1518 if (tun->flags & TUN_VNET_HDR)
1519 flags |= IFF_VNET_HDR;
1521 if (tun->flags & TUN_TAP_MQ)
1522 flags |= IFF_MULTI_QUEUE;
1527 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
1530 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1531 return sprintf(buf, "0x%x\n", tun_flags(tun));
1534 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
1537 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1538 return uid_valid(tun->owner)?
1539 sprintf(buf, "%u\n",
1540 from_kuid_munged(current_user_ns(), tun->owner)):
1541 sprintf(buf, "-1\n");
1544 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
1547 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1548 return gid_valid(tun->group) ?
1549 sprintf(buf, "%u\n",
1550 from_kgid_munged(current_user_ns(), tun->group)):
1551 sprintf(buf, "-1\n");
1554 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
1555 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
1556 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
1558 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
1560 struct tun_struct *tun;
1561 struct tun_file *tfile = file->private_data;
1562 struct net_device *dev;
1565 dev = __dev_get_by_name(net, ifr->ifr_name);
1567 if (ifr->ifr_flags & IFF_TUN_EXCL)
1569 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
1570 tun = netdev_priv(dev);
1571 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
1572 tun = netdev_priv(dev);
1576 if (tun_not_capable(tun))
1578 err = security_tun_dev_attach(tfile->socket.sk);
1582 err = tun_attach(tun, file);
1586 if (tun->flags & TUN_TAP_MQ &&
1587 (tun->numqueues + tun->numdisabled > 1))
1592 unsigned long flags = 0;
1594 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1596 err = security_tun_dev_create();
1601 if (ifr->ifr_flags & IFF_TUN) {
1603 flags |= TUN_TUN_DEV;
1605 } else if (ifr->ifr_flags & IFF_TAP) {
1607 flags |= TUN_TAP_DEV;
1613 name = ifr->ifr_name;
1615 dev = alloc_netdev_mqs(sizeof(struct tun_struct), name,
1617 MAX_TAP_QUEUES, MAX_TAP_QUEUES);
1621 dev_net_set(dev, net);
1622 dev->rtnl_link_ops = &tun_link_ops;
1624 tun = netdev_priv(dev);
1627 tun->txflt.count = 0;
1628 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
1630 tun->filter_attached = false;
1631 tun->sndbuf = tfile->socket.sk->sk_sndbuf;
1633 spin_lock_init(&tun->lock);
1635 security_tun_dev_post_create(&tfile->sk);
1639 err = tun_flow_init(tun);
1643 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
1645 dev->features = dev->hw_features;
1647 INIT_LIST_HEAD(&tun->disabled);
1648 err = tun_attach(tun, file);
1652 err = register_netdevice(tun->dev);
1656 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
1657 device_create_file(&tun->dev->dev, &dev_attr_owner) ||
1658 device_create_file(&tun->dev->dev, &dev_attr_group))
1659 pr_err("Failed to create tun sysfs files\n");
1661 netif_carrier_on(tun->dev);
1664 tun_debug(KERN_INFO, tun, "tun_set_iff\n");
1666 if (ifr->ifr_flags & IFF_NO_PI)
1667 tun->flags |= TUN_NO_PI;
1669 tun->flags &= ~TUN_NO_PI;
1671 /* This flag has no real effect. We track the value for backwards
1674 if (ifr->ifr_flags & IFF_ONE_QUEUE)
1675 tun->flags |= TUN_ONE_QUEUE;
1677 tun->flags &= ~TUN_ONE_QUEUE;
1679 if (ifr->ifr_flags & IFF_VNET_HDR)
1680 tun->flags |= TUN_VNET_HDR;
1682 tun->flags &= ~TUN_VNET_HDR;
1684 if (ifr->ifr_flags & IFF_MULTI_QUEUE)
1685 tun->flags |= TUN_TAP_MQ;
1687 tun->flags &= ~TUN_TAP_MQ;
1689 /* Make sure persistent devices do not get stuck in
1692 if (netif_running(tun->dev))
1693 netif_tx_wake_all_queues(tun->dev);
1695 strcpy(ifr->ifr_name, tun->dev->name);
1703 static void tun_get_iff(struct net *net, struct tun_struct *tun,
1706 tun_debug(KERN_INFO, tun, "tun_get_iff\n");
1708 strcpy(ifr->ifr_name, tun->dev->name);
1710 ifr->ifr_flags = tun_flags(tun);
1714 /* This is like a cut-down ethtool ops, except done via tun fd so no
1715 * privs required. */
1716 static int set_offload(struct tun_struct *tun, unsigned long arg)
1718 netdev_features_t features = 0;
1720 if (arg & TUN_F_CSUM) {
1721 features |= NETIF_F_HW_CSUM;
1724 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1725 if (arg & TUN_F_TSO_ECN) {
1726 features |= NETIF_F_TSO_ECN;
1727 arg &= ~TUN_F_TSO_ECN;
1729 if (arg & TUN_F_TSO4)
1730 features |= NETIF_F_TSO;
1731 if (arg & TUN_F_TSO6)
1732 features |= NETIF_F_TSO6;
1733 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1736 if (arg & TUN_F_UFO) {
1737 features |= NETIF_F_UFO;
1742 /* This gives the user a way to test for new features in future by
1743 * trying to set them. */
1747 tun->set_features = features;
1748 netdev_update_features(tun->dev);
1753 static void tun_detach_filter(struct tun_struct *tun, int n)
1756 struct tun_file *tfile;
1758 for (i = 0; i < n; i++) {
1759 tfile = rcu_dereference_protected(tun->tfiles[i],
1760 lockdep_rtnl_is_held());
1761 sk_detach_filter(tfile->socket.sk);
1764 tun->filter_attached = false;
1767 static int tun_attach_filter(struct tun_struct *tun)
1770 struct tun_file *tfile;
1772 for (i = 0; i < tun->numqueues; i++) {
1773 tfile = rcu_dereference_protected(tun->tfiles[i],
1774 lockdep_rtnl_is_held());
1775 ret = sk_attach_filter(&tun->fprog, tfile->socket.sk);
1777 tun_detach_filter(tun, i);
1782 tun->filter_attached = true;
1786 static void tun_set_sndbuf(struct tun_struct *tun)
1788 struct tun_file *tfile;
1791 for (i = 0; i < tun->numqueues; i++) {
1792 tfile = rcu_dereference_protected(tun->tfiles[i],
1793 lockdep_rtnl_is_held());
1794 tfile->socket.sk->sk_sndbuf = tun->sndbuf;
1798 static int tun_set_queue(struct file *file, struct ifreq *ifr)
1800 struct tun_file *tfile = file->private_data;
1801 struct tun_struct *tun;
1806 if (ifr->ifr_flags & IFF_ATTACH_QUEUE) {
1807 tun = tfile->detached;
1810 else if (tun_not_capable(tun))
1813 ret = tun_attach(tun, file);
1814 } else if (ifr->ifr_flags & IFF_DETACH_QUEUE) {
1815 tun = rcu_dereference_protected(tfile->tun,
1816 lockdep_rtnl_is_held());
1817 if (!tun || !(tun->flags & TUN_TAP_MQ))
1820 __tun_detach(tfile, false);
1828 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
1829 unsigned long arg, int ifreq_len)
1831 struct tun_file *tfile = file->private_data;
1832 struct tun_struct *tun;
1833 void __user* argp = (void __user*)arg;
1841 if (cmd == TUNSETIFF || cmd == TUNSETQUEUE || _IOC_TYPE(cmd) == 0x89) {
1842 if (copy_from_user(&ifr, argp, ifreq_len))
1845 memset(&ifr, 0, sizeof(ifr));
1847 if (cmd == TUNGETFEATURES) {
1848 /* Currently this just means: "what IFF flags are valid?".
1849 * This is needed because we never checked for invalid flags on
1851 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
1852 IFF_VNET_HDR | IFF_MULTI_QUEUE,
1853 (unsigned int __user*)argp);
1854 } else if (cmd == TUNSETQUEUE)
1855 return tun_set_queue(file, &ifr);
1860 tun = __tun_get(tfile);
1861 if (cmd == TUNSETIFF && !tun) {
1862 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1864 ret = tun_set_iff(tfile->net, file, &ifr);
1869 if (copy_to_user(argp, &ifr, ifreq_len))
1878 tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %u\n", cmd);
1883 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1885 if (copy_to_user(argp, &ifr, ifreq_len))
1890 /* Disable/Enable checksum */
1892 /* [unimplemented] */
1893 tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n",
1894 arg ? "disabled" : "enabled");
1898 /* Disable/Enable persist mode. Keep an extra reference to the
1899 * module to prevent the module being unprobed.
1902 tun->flags |= TUN_PERSIST;
1903 __module_get(THIS_MODULE);
1905 tun->flags &= ~TUN_PERSIST;
1906 module_put(THIS_MODULE);
1909 tun_debug(KERN_INFO, tun, "persist %s\n",
1910 arg ? "enabled" : "disabled");
1914 /* Set owner of the device */
1915 owner = make_kuid(current_user_ns(), arg);
1916 if (!uid_valid(owner)) {
1921 tun_debug(KERN_INFO, tun, "owner set to %u\n",
1922 from_kuid(&init_user_ns, tun->owner));
1926 /* Set group of the device */
1927 group = make_kgid(current_user_ns(), arg);
1928 if (!gid_valid(group)) {
1933 tun_debug(KERN_INFO, tun, "group set to %u\n",
1934 from_kgid(&init_user_ns, tun->group));
1938 /* Only allow setting the type when the interface is down */
1939 if (tun->dev->flags & IFF_UP) {
1940 tun_debug(KERN_INFO, tun,
1941 "Linktype set failed because interface is up\n");
1944 tun->dev->type = (int) arg;
1945 tun_debug(KERN_INFO, tun, "linktype set to %d\n",
1957 ret = set_offload(tun, arg);
1960 case TUNSETTXFILTER:
1961 /* Can be set only for TAPs */
1963 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1965 ret = update_filter(&tun->txflt, (void __user *)arg);
1969 /* Get hw address */
1970 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
1971 ifr.ifr_hwaddr.sa_family = tun->dev->type;
1972 if (copy_to_user(argp, &ifr, ifreq_len))
1977 /* Set hw address */
1978 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n",
1979 ifr.ifr_hwaddr.sa_data);
1981 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
1985 sndbuf = tfile->socket.sk->sk_sndbuf;
1986 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
1991 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
1996 tun->sndbuf = sndbuf;
1997 tun_set_sndbuf(tun);
2000 case TUNGETVNETHDRSZ:
2001 vnet_hdr_sz = tun->vnet_hdr_sz;
2002 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
2006 case TUNSETVNETHDRSZ:
2007 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
2011 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
2016 tun->vnet_hdr_sz = vnet_hdr_sz;
2019 case TUNATTACHFILTER:
2020 /* Can be set only for TAPs */
2022 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
2025 if (copy_from_user(&tun->fprog, argp, sizeof(tun->fprog)))
2028 ret = tun_attach_filter(tun);
2031 case TUNDETACHFILTER:
2032 /* Can be set only for TAPs */
2034 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
2037 tun_detach_filter(tun, tun->numqueues);
2052 static long tun_chr_ioctl(struct file *file,
2053 unsigned int cmd, unsigned long arg)
2055 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
2058 #ifdef CONFIG_COMPAT
2059 static long tun_chr_compat_ioctl(struct file *file,
2060 unsigned int cmd, unsigned long arg)
2065 case TUNSETTXFILTER:
2070 arg = (unsigned long)compat_ptr(arg);
2073 arg = (compat_ulong_t)arg;
2078 * compat_ifreq is shorter than ifreq, so we must not access beyond
2079 * the end of that structure. All fields that are used in this
2080 * driver are compatible though, we don't need to convert the
2083 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
2085 #endif /* CONFIG_COMPAT */
2087 static int tun_chr_fasync(int fd, struct file *file, int on)
2089 struct tun_file *tfile = file->private_data;
2092 if ((ret = fasync_helper(fd, file, on, &tfile->fasync)) < 0)
2096 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
2099 tfile->flags |= TUN_FASYNC;
2101 tfile->flags &= ~TUN_FASYNC;
2107 static int tun_chr_open(struct inode *inode, struct file * file)
2109 struct tun_file *tfile;
2111 DBG1(KERN_INFO, "tunX: tun_chr_open\n");
2113 tfile = (struct tun_file *)sk_alloc(&init_net, AF_UNSPEC, GFP_KERNEL,
2117 rcu_assign_pointer(tfile->tun, NULL);
2118 tfile->net = get_net(current->nsproxy->net_ns);
2121 rcu_assign_pointer(tfile->socket.wq, &tfile->wq);
2122 init_waitqueue_head(&tfile->wq.wait);
2124 tfile->socket.file = file;
2125 tfile->socket.ops = &tun_socket_ops;
2127 sock_init_data(&tfile->socket, &tfile->sk);
2128 sk_change_net(&tfile->sk, tfile->net);
2130 tfile->sk.sk_write_space = tun_sock_write_space;
2131 tfile->sk.sk_sndbuf = INT_MAX;
2133 file->private_data = tfile;
2134 set_bit(SOCK_EXTERNALLY_ALLOCATED, &tfile->socket.flags);
2135 INIT_LIST_HEAD(&tfile->next);
2140 static int tun_chr_close(struct inode *inode, struct file *file)
2142 struct tun_file *tfile = file->private_data;
2143 struct net *net = tfile->net;
2145 tun_detach(tfile, true);
2151 static const struct file_operations tun_fops = {
2152 .owner = THIS_MODULE,
2153 .llseek = no_llseek,
2154 .read = do_sync_read,
2155 .aio_read = tun_chr_aio_read,
2156 .write = do_sync_write,
2157 .aio_write = tun_chr_aio_write,
2158 .poll = tun_chr_poll,
2159 .unlocked_ioctl = tun_chr_ioctl,
2160 #ifdef CONFIG_COMPAT
2161 .compat_ioctl = tun_chr_compat_ioctl,
2163 .open = tun_chr_open,
2164 .release = tun_chr_close,
2165 .fasync = tun_chr_fasync
2168 static struct miscdevice tun_miscdev = {
2171 .nodename = "net/tun",
2175 /* ethtool interface */
2177 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
2180 cmd->advertising = 0;
2181 ethtool_cmd_speed_set(cmd, SPEED_10);
2182 cmd->duplex = DUPLEX_FULL;
2183 cmd->port = PORT_TP;
2184 cmd->phy_address = 0;
2185 cmd->transceiver = XCVR_INTERNAL;
2186 cmd->autoneg = AUTONEG_DISABLE;
2192 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
2194 struct tun_struct *tun = netdev_priv(dev);
2196 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
2197 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
2199 switch (tun->flags & TUN_TYPE_MASK) {
2201 strlcpy(info->bus_info, "tun", sizeof(info->bus_info));
2204 strlcpy(info->bus_info, "tap", sizeof(info->bus_info));
2209 static u32 tun_get_msglevel(struct net_device *dev)
2212 struct tun_struct *tun = netdev_priv(dev);
2219 static void tun_set_msglevel(struct net_device *dev, u32 value)
2222 struct tun_struct *tun = netdev_priv(dev);
2227 static const struct ethtool_ops tun_ethtool_ops = {
2228 .get_settings = tun_get_settings,
2229 .get_drvinfo = tun_get_drvinfo,
2230 .get_msglevel = tun_get_msglevel,
2231 .set_msglevel = tun_set_msglevel,
2232 .get_link = ethtool_op_get_link,
2236 static int __init tun_init(void)
2240 pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
2241 pr_info("%s\n", DRV_COPYRIGHT);
2243 ret = rtnl_link_register(&tun_link_ops);
2245 pr_err("Can't register link_ops\n");
2249 ret = misc_register(&tun_miscdev);
2251 pr_err("Can't register misc device %d\n", TUN_MINOR);
2256 rtnl_link_unregister(&tun_link_ops);
2261 static void tun_cleanup(void)
2263 misc_deregister(&tun_miscdev);
2264 rtnl_link_unregister(&tun_link_ops);
2267 /* Get an underlying socket object from tun file. Returns error unless file is
2268 * attached to a device. The returned object works like a packet socket, it
2269 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
2270 * holding a reference to the file for as long as the socket is in use. */
2271 struct socket *tun_get_socket(struct file *file)
2273 struct tun_file *tfile;
2274 if (file->f_op != &tun_fops)
2275 return ERR_PTR(-EINVAL);
2276 tfile = file->private_data;
2278 return ERR_PTR(-EBADFD);
2279 return &tfile->socket;
2281 EXPORT_SYMBOL_GPL(tun_get_socket);
2283 module_init(tun_init);
2284 module_exit(tun_cleanup);
2285 MODULE_DESCRIPTION(DRV_DESCRIPTION);
2286 MODULE_AUTHOR(DRV_COPYRIGHT);
2287 MODULE_LICENSE("GPL");
2288 MODULE_ALIAS_MISCDEV(TUN_MINOR);
2289 MODULE_ALIAS("devname:net/tun");