2 * TUN - Universal TUN/TAP device driver.
3 * Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * $Id: tun.c,v 1.15 2002/03/01 02:44:24 maxk Exp $
21 * Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14
22 * Add TUNSETLINK ioctl to set the link encapsulation
24 * Mark Smith <markzzzsmith@yahoo.com.au>
25 * Use eth_random_addr() for tap MAC address.
27 * Harald Roelle <harald.roelle@ifi.lmu.de> 2004/04/20
28 * Fixes in packet dropping, queue length setting and queue wakeup.
29 * Increased default tx queue length.
33 * Daniel Podlejski <underley@underley.eu.org>
34 * Modifications for 2.3.99-pre5 kernel.
37 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
39 #define DRV_NAME "tun"
40 #define DRV_VERSION "1.6"
41 #define DRV_DESCRIPTION "Universal TUN/TAP device driver"
42 #define DRV_COPYRIGHT "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>"
44 #include <linux/module.h>
45 #include <linux/errno.h>
46 #include <linux/kernel.h>
47 #include <linux/major.h>
48 #include <linux/slab.h>
49 #include <linux/poll.h>
50 #include <linux/fcntl.h>
51 #include <linux/init.h>
52 #include <linux/skbuff.h>
53 #include <linux/netdevice.h>
54 #include <linux/etherdevice.h>
55 #include <linux/miscdevice.h>
56 #include <linux/ethtool.h>
57 #include <linux/rtnetlink.h>
58 #include <linux/compat.h>
60 #include <linux/if_arp.h>
61 #include <linux/if_ether.h>
62 #include <linux/if_tun.h>
63 #include <linux/if_vlan.h>
64 #include <linux/crc32.h>
65 #include <linux/nsproxy.h>
66 #include <linux/virtio_net.h>
67 #include <linux/rcupdate.h>
69 #include <net/net_namespace.h>
70 #include <net/netns/generic.h>
71 #include <net/rtnetlink.h>
73 #include <linux/seq_file.h>
74 #include <linux/uio.h>
76 #include <asm/uaccess.h>
78 /* Uncomment to enable debugging */
79 /* #define TUN_DEBUG 1 */
84 #define tun_debug(level, tun, fmt, args...) \
87 netdev_printk(level, tun->dev, fmt, ##args); \
89 #define DBG1(level, fmt, args...) \
92 printk(level fmt, ##args); \
95 #define tun_debug(level, tun, fmt, args...) \
98 netdev_printk(level, tun->dev, fmt, ##args); \
100 #define DBG1(level, fmt, args...) \
103 printk(level fmt, ##args); \
107 #define GOODCOPY_LEN 128
109 #define FLT_EXACT_COUNT 8
111 unsigned int count; /* Number of addrs. Zero means disabled */
112 u32 mask[2]; /* Mask of the hashed addrs */
113 unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN];
116 /* DEFAULT_MAX_NUM_RSS_QUEUES were chosen to let the rx/tx queues allocated for
117 * the netdevice to be fit in one page. So we can make sure the success of
118 * memory allocation. TODO: increase the limit. */
119 #define MAX_TAP_QUEUES DEFAULT_MAX_NUM_RSS_QUEUES
120 #define MAX_TAP_FLOWS 4096
122 #define TUN_FLOW_EXPIRE (3 * HZ)
124 /* A tun_file connects an open character device to a tuntap netdevice. It
125 * also contains all socket related structures (except sock_fprog and tap_filter)
126 * to serve as one transmit queue for tuntap device. The sock_fprog and
127 * tap_filter were kept in tun_struct since they were used for filtering for the
128 * netdevice not for a specific queue (at least I didn't see the requirement for
132 * The tun_file and tun_struct are loosely coupled, the pointer from one to the
133 * other can only be read while rcu_read_lock or rtnl_lock is held.
137 struct socket socket;
139 struct tun_struct __rcu *tun;
141 struct fasync_struct *fasync;
142 /* only used for fasnyc */
146 unsigned int ifindex;
148 struct list_head next;
149 struct tun_struct *detached;
152 struct tun_flow_entry {
153 struct hlist_node hash_link;
155 struct tun_struct *tun;
160 unsigned long updated;
163 #define TUN_NUM_FLOW_ENTRIES 1024
165 /* Since the socket were moved to tun_file, to preserve the behavior of persist
166 * device, socket filter, sndbuf and vnet header size were restore when the
167 * file were attached to a persist device.
170 struct tun_file __rcu *tfiles[MAX_TAP_QUEUES];
171 unsigned int numqueues;
176 struct net_device *dev;
177 netdev_features_t set_features;
178 #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \
183 struct tap_filter txflt;
184 struct sock_fprog fprog;
185 /* protected by rtnl lock */
186 bool filter_attached;
191 struct hlist_head flows[TUN_NUM_FLOW_ENTRIES];
192 struct timer_list flow_gc_timer;
193 unsigned long ageing_time;
194 unsigned int numdisabled;
195 struct list_head disabled;
200 static inline u32 tun_hashfn(u32 rxhash)
202 return rxhash & 0x3ff;
205 static struct tun_flow_entry *tun_flow_find(struct hlist_head *head, u32 rxhash)
207 struct tun_flow_entry *e;
209 hlist_for_each_entry_rcu(e, head, hash_link) {
210 if (e->rxhash == rxhash)
216 static struct tun_flow_entry *tun_flow_create(struct tun_struct *tun,
217 struct hlist_head *head,
218 u32 rxhash, u16 queue_index)
220 struct tun_flow_entry *e = kmalloc(sizeof(*e), GFP_ATOMIC);
223 tun_debug(KERN_INFO, tun, "create flow: hash %u index %u\n",
224 rxhash, queue_index);
225 e->updated = jiffies;
228 e->queue_index = queue_index;
230 hlist_add_head_rcu(&e->hash_link, head);
236 static void tun_flow_delete(struct tun_struct *tun, struct tun_flow_entry *e)
238 tun_debug(KERN_INFO, tun, "delete flow: hash %u index %u\n",
239 e->rxhash, e->queue_index);
240 sock_rps_reset_flow_hash(e->rps_rxhash);
241 hlist_del_rcu(&e->hash_link);
246 static void tun_flow_flush(struct tun_struct *tun)
250 spin_lock_bh(&tun->lock);
251 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
252 struct tun_flow_entry *e;
253 struct hlist_node *n;
255 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link)
256 tun_flow_delete(tun, e);
258 spin_unlock_bh(&tun->lock);
261 static void tun_flow_delete_by_queue(struct tun_struct *tun, u16 queue_index)
265 spin_lock_bh(&tun->lock);
266 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
267 struct tun_flow_entry *e;
268 struct hlist_node *n;
270 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
271 if (e->queue_index == queue_index)
272 tun_flow_delete(tun, e);
275 spin_unlock_bh(&tun->lock);
278 static void tun_flow_cleanup(unsigned long data)
280 struct tun_struct *tun = (struct tun_struct *)data;
281 unsigned long delay = tun->ageing_time;
282 unsigned long next_timer = jiffies + delay;
283 unsigned long count = 0;
286 tun_debug(KERN_INFO, tun, "tun_flow_cleanup\n");
288 spin_lock_bh(&tun->lock);
289 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
290 struct tun_flow_entry *e;
291 struct hlist_node *n;
293 hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
294 unsigned long this_timer;
296 this_timer = e->updated + delay;
297 if (time_before_eq(this_timer, jiffies))
298 tun_flow_delete(tun, e);
299 else if (time_before(this_timer, next_timer))
300 next_timer = this_timer;
305 mod_timer(&tun->flow_gc_timer, round_jiffies_up(next_timer));
306 spin_unlock_bh(&tun->lock);
309 static void tun_flow_update(struct tun_struct *tun, u32 rxhash,
310 struct tun_file *tfile)
312 struct hlist_head *head;
313 struct tun_flow_entry *e;
314 unsigned long delay = tun->ageing_time;
315 u16 queue_index = tfile->queue_index;
320 head = &tun->flows[tun_hashfn(rxhash)];
324 /* We may get a very small possibility of OOO during switching, not
325 * worth to optimize.*/
326 if (tun->numqueues == 1 || tfile->detached)
329 e = tun_flow_find(head, rxhash);
331 /* TODO: keep queueing to old queue until it's empty? */
332 e->queue_index = queue_index;
333 e->updated = jiffies;
334 sock_rps_record_flow_hash(e->rps_rxhash);
336 spin_lock_bh(&tun->lock);
337 if (!tun_flow_find(head, rxhash) &&
338 tun->flow_count < MAX_TAP_FLOWS)
339 tun_flow_create(tun, head, rxhash, queue_index);
341 if (!timer_pending(&tun->flow_gc_timer))
342 mod_timer(&tun->flow_gc_timer,
343 round_jiffies_up(jiffies + delay));
344 spin_unlock_bh(&tun->lock);
352 * Save the hash received in the stack receive path and update the
353 * flow_hash table accordingly.
355 static inline void tun_flow_save_rps_rxhash(struct tun_flow_entry *e, u32 hash)
357 if (unlikely(e->rps_rxhash != hash)) {
358 sock_rps_reset_flow_hash(e->rps_rxhash);
359 e->rps_rxhash = hash;
363 /* We try to identify a flow through its rxhash first. The reason that
364 * we do not check rxq no. is because some cards(e.g 82599), chooses
365 * the rxq based on the txq where the last packet of the flow comes. As
366 * the userspace application move between processors, we may get a
367 * different rxq no. here. If we could not get rxhash, then we would
368 * hope the rxq no. may help here.
370 static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb,
371 void *accel_priv, select_queue_fallback_t fallback)
373 struct tun_struct *tun = netdev_priv(dev);
374 struct tun_flow_entry *e;
379 numqueues = ACCESS_ONCE(tun->numqueues);
381 txq = skb_get_hash(skb);
383 e = tun_flow_find(&tun->flows[tun_hashfn(txq)], txq);
385 tun_flow_save_rps_rxhash(e, txq);
386 txq = e->queue_index;
388 /* use multiply and shift instead of expensive divide */
389 txq = ((u64)txq * numqueues) >> 32;
390 } else if (likely(skb_rx_queue_recorded(skb))) {
391 txq = skb_get_rx_queue(skb);
392 while (unlikely(txq >= numqueues))
400 static inline bool tun_not_capable(struct tun_struct *tun)
402 const struct cred *cred = current_cred();
403 struct net *net = dev_net(tun->dev);
405 return ((uid_valid(tun->owner) && !uid_eq(cred->euid, tun->owner)) ||
406 (gid_valid(tun->group) && !in_egroup_p(tun->group))) &&
407 !ns_capable(net->user_ns, CAP_NET_ADMIN);
410 static void tun_set_real_num_queues(struct tun_struct *tun)
412 netif_set_real_num_tx_queues(tun->dev, tun->numqueues);
413 netif_set_real_num_rx_queues(tun->dev, tun->numqueues);
416 static void tun_disable_queue(struct tun_struct *tun, struct tun_file *tfile)
418 tfile->detached = tun;
419 list_add_tail(&tfile->next, &tun->disabled);
423 static struct tun_struct *tun_enable_queue(struct tun_file *tfile)
425 struct tun_struct *tun = tfile->detached;
427 tfile->detached = NULL;
428 list_del_init(&tfile->next);
433 static void tun_queue_purge(struct tun_file *tfile)
435 skb_queue_purge(&tfile->sk.sk_receive_queue);
436 skb_queue_purge(&tfile->sk.sk_error_queue);
439 static void __tun_detach(struct tun_file *tfile, bool clean)
441 struct tun_file *ntfile;
442 struct tun_struct *tun;
444 tun = rtnl_dereference(tfile->tun);
446 if (tun && !tfile->detached) {
447 u16 index = tfile->queue_index;
448 BUG_ON(index >= tun->numqueues);
450 rcu_assign_pointer(tun->tfiles[index],
451 tun->tfiles[tun->numqueues - 1]);
452 ntfile = rtnl_dereference(tun->tfiles[index]);
453 ntfile->queue_index = index;
457 RCU_INIT_POINTER(tfile->tun, NULL);
458 sock_put(&tfile->sk);
460 tun_disable_queue(tun, tfile);
463 tun_flow_delete_by_queue(tun, tun->numqueues + 1);
464 /* Drop read queue */
465 tun_queue_purge(tfile);
466 tun_set_real_num_queues(tun);
467 } else if (tfile->detached && clean) {
468 tun = tun_enable_queue(tfile);
469 sock_put(&tfile->sk);
473 if (tun && tun->numqueues == 0 && tun->numdisabled == 0) {
474 netif_carrier_off(tun->dev);
476 if (!(tun->flags & TUN_PERSIST) &&
477 tun->dev->reg_state == NETREG_REGISTERED)
478 unregister_netdevice(tun->dev);
481 BUG_ON(!test_bit(SOCK_EXTERNALLY_ALLOCATED,
482 &tfile->socket.flags));
483 sk_release_kernel(&tfile->sk);
487 static void tun_detach(struct tun_file *tfile, bool clean)
490 __tun_detach(tfile, clean);
494 static void tun_detach_all(struct net_device *dev)
496 struct tun_struct *tun = netdev_priv(dev);
497 struct tun_file *tfile, *tmp;
498 int i, n = tun->numqueues;
500 for (i = 0; i < n; i++) {
501 tfile = rtnl_dereference(tun->tfiles[i]);
503 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
504 RCU_INIT_POINTER(tfile->tun, NULL);
507 list_for_each_entry(tfile, &tun->disabled, next) {
508 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
509 RCU_INIT_POINTER(tfile->tun, NULL);
511 BUG_ON(tun->numqueues != 0);
514 for (i = 0; i < n; i++) {
515 tfile = rtnl_dereference(tun->tfiles[i]);
516 /* Drop read queue */
517 tun_queue_purge(tfile);
518 sock_put(&tfile->sk);
520 list_for_each_entry_safe(tfile, tmp, &tun->disabled, next) {
521 tun_enable_queue(tfile);
522 tun_queue_purge(tfile);
523 sock_put(&tfile->sk);
525 BUG_ON(tun->numdisabled != 0);
527 if (tun->flags & TUN_PERSIST)
528 module_put(THIS_MODULE);
531 static int tun_attach(struct tun_struct *tun, struct file *file, bool skip_filter)
533 struct tun_file *tfile = file->private_data;
536 err = security_tun_dev_attach(tfile->socket.sk, tun->security);
541 if (rtnl_dereference(tfile->tun) && !tfile->detached)
545 if (!(tun->flags & TUN_TAP_MQ) && tun->numqueues == 1)
549 if (!tfile->detached &&
550 tun->numqueues + tun->numdisabled == MAX_TAP_QUEUES)
555 /* Re-attach the filter to persist device */
556 if (!skip_filter && (tun->filter_attached == true)) {
557 err = sk_attach_filter(&tun->fprog, tfile->socket.sk);
561 tfile->queue_index = tun->numqueues;
562 rcu_assign_pointer(tfile->tun, tun);
563 rcu_assign_pointer(tun->tfiles[tun->numqueues], tfile);
567 tun_enable_queue(tfile);
569 sock_hold(&tfile->sk);
571 tun_set_real_num_queues(tun);
573 /* device is allowed to go away first, so no need to hold extra
581 static struct tun_struct *__tun_get(struct tun_file *tfile)
583 struct tun_struct *tun;
586 tun = rcu_dereference(tfile->tun);
594 static struct tun_struct *tun_get(struct file *file)
596 return __tun_get(file->private_data);
599 static void tun_put(struct tun_struct *tun)
605 static void addr_hash_set(u32 *mask, const u8 *addr)
607 int n = ether_crc(ETH_ALEN, addr) >> 26;
608 mask[n >> 5] |= (1 << (n & 31));
611 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
613 int n = ether_crc(ETH_ALEN, addr) >> 26;
614 return mask[n >> 5] & (1 << (n & 31));
617 static int update_filter(struct tap_filter *filter, void __user *arg)
619 struct { u8 u[ETH_ALEN]; } *addr;
620 struct tun_filter uf;
621 int err, alen, n, nexact;
623 if (copy_from_user(&uf, arg, sizeof(uf)))
632 alen = ETH_ALEN * uf.count;
633 addr = kmalloc(alen, GFP_KERNEL);
637 if (copy_from_user(addr, arg + sizeof(uf), alen)) {
642 /* The filter is updated without holding any locks. Which is
643 * perfectly safe. We disable it first and in the worst
644 * case we'll accept a few undesired packets. */
648 /* Use first set of addresses as an exact filter */
649 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
650 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
654 /* Remaining multicast addresses are hashed,
655 * unicast will leave the filter disabled. */
656 memset(filter->mask, 0, sizeof(filter->mask));
657 for (; n < uf.count; n++) {
658 if (!is_multicast_ether_addr(addr[n].u)) {
659 err = 0; /* no filter */
662 addr_hash_set(filter->mask, addr[n].u);
665 /* For ALLMULTI just set the mask to all ones.
666 * This overrides the mask populated above. */
667 if ((uf.flags & TUN_FLT_ALLMULTI))
668 memset(filter->mask, ~0, sizeof(filter->mask));
670 /* Now enable the filter */
672 filter->count = nexact;
674 /* Return the number of exact filters */
682 /* Returns: 0 - drop, !=0 - accept */
683 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
685 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
687 struct ethhdr *eh = (struct ethhdr *) skb->data;
691 for (i = 0; i < filter->count; i++)
692 if (ether_addr_equal(eh->h_dest, filter->addr[i]))
695 /* Inexact match (multicast only) */
696 if (is_multicast_ether_addr(eh->h_dest))
697 return addr_hash_test(filter->mask, eh->h_dest);
703 * Checks whether the packet is accepted or not.
704 * Returns: 0 - drop, !=0 - accept
706 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
711 return run_filter(filter, skb);
714 /* Network device part of the driver */
716 static const struct ethtool_ops tun_ethtool_ops;
718 /* Net device detach from fd. */
719 static void tun_net_uninit(struct net_device *dev)
724 /* Net device open. */
725 static int tun_net_open(struct net_device *dev)
727 netif_tx_start_all_queues(dev);
731 /* Net device close. */
732 static int tun_net_close(struct net_device *dev)
734 netif_tx_stop_all_queues(dev);
738 /* Net device start xmit */
739 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
741 struct tun_struct *tun = netdev_priv(dev);
742 int txq = skb->queue_mapping;
743 struct tun_file *tfile;
747 tfile = rcu_dereference(tun->tfiles[txq]);
748 numqueues = ACCESS_ONCE(tun->numqueues);
750 /* Drop packet if interface is not attached */
751 if (txq >= numqueues)
754 if (numqueues == 1) {
755 /* Select queue was not called for the skbuff, so we extract the
756 * RPS hash and save it into the flow_table here.
760 rxhash = skb_get_hash(skb);
762 struct tun_flow_entry *e;
763 e = tun_flow_find(&tun->flows[tun_hashfn(rxhash)],
766 tun_flow_save_rps_rxhash(e, rxhash);
770 tun_debug(KERN_INFO, tun, "tun_net_xmit %d\n", skb->len);
774 /* Drop if the filter does not like it.
775 * This is a noop if the filter is disabled.
776 * Filter can be enabled only for the TAP devices. */
777 if (!check_filter(&tun->txflt, skb))
780 if (tfile->socket.sk->sk_filter &&
781 sk_filter(tfile->socket.sk, skb))
784 /* Limit the number of packets queued by dividing txq length with the
787 if (skb_queue_len(&tfile->socket.sk->sk_receive_queue) * numqueues
788 >= dev->tx_queue_len)
791 if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
795 sock_tx_timestamp(skb->sk, &skb_shinfo(skb)->tx_flags);
796 sw_tx_timestamp(skb);
799 /* Orphan the skb - required as we might hang on to it
800 * for indefinite time.
807 skb_queue_tail(&tfile->socket.sk->sk_receive_queue, skb);
809 /* Notify and wake up reader process */
810 if (tfile->flags & TUN_FASYNC)
811 kill_fasync(&tfile->fasync, SIGIO, POLL_IN);
812 tfile->socket.sk->sk_data_ready(tfile->socket.sk);
818 dev->stats.tx_dropped++;
825 static void tun_net_mclist(struct net_device *dev)
828 * This callback is supposed to deal with mc filter in
829 * _rx_ path and has nothing to do with the _tx_ path.
830 * In rx path we always accept everything userspace gives us.
835 #define MAX_MTU 65535
838 tun_net_change_mtu(struct net_device *dev, int new_mtu)
840 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
846 static netdev_features_t tun_net_fix_features(struct net_device *dev,
847 netdev_features_t features)
849 struct tun_struct *tun = netdev_priv(dev);
851 return (features & tun->set_features) | (features & ~TUN_USER_FEATURES);
853 #ifdef CONFIG_NET_POLL_CONTROLLER
854 static void tun_poll_controller(struct net_device *dev)
857 * Tun only receives frames when:
858 * 1) the char device endpoint gets data from user space
859 * 2) the tun socket gets a sendmsg call from user space
860 * Since both of those are synchronous operations, we are guaranteed
861 * never to have pending data when we poll for it
862 * so there is nothing to do here but return.
863 * We need this though so netpoll recognizes us as an interface that
864 * supports polling, which enables bridge devices in virt setups to
865 * still use netconsole
870 static const struct net_device_ops tun_netdev_ops = {
871 .ndo_uninit = tun_net_uninit,
872 .ndo_open = tun_net_open,
873 .ndo_stop = tun_net_close,
874 .ndo_start_xmit = tun_net_xmit,
875 .ndo_change_mtu = tun_net_change_mtu,
876 .ndo_fix_features = tun_net_fix_features,
877 .ndo_select_queue = tun_select_queue,
878 #ifdef CONFIG_NET_POLL_CONTROLLER
879 .ndo_poll_controller = tun_poll_controller,
883 static const struct net_device_ops tap_netdev_ops = {
884 .ndo_uninit = tun_net_uninit,
885 .ndo_open = tun_net_open,
886 .ndo_stop = tun_net_close,
887 .ndo_start_xmit = tun_net_xmit,
888 .ndo_change_mtu = tun_net_change_mtu,
889 .ndo_fix_features = tun_net_fix_features,
890 .ndo_set_rx_mode = tun_net_mclist,
891 .ndo_set_mac_address = eth_mac_addr,
892 .ndo_validate_addr = eth_validate_addr,
893 .ndo_select_queue = tun_select_queue,
894 #ifdef CONFIG_NET_POLL_CONTROLLER
895 .ndo_poll_controller = tun_poll_controller,
899 static void tun_flow_init(struct tun_struct *tun)
903 for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++)
904 INIT_HLIST_HEAD(&tun->flows[i]);
906 tun->ageing_time = TUN_FLOW_EXPIRE;
907 setup_timer(&tun->flow_gc_timer, tun_flow_cleanup, (unsigned long)tun);
908 mod_timer(&tun->flow_gc_timer,
909 round_jiffies_up(jiffies + tun->ageing_time));
912 static void tun_flow_uninit(struct tun_struct *tun)
914 del_timer_sync(&tun->flow_gc_timer);
918 /* Initialize net device. */
919 static void tun_net_init(struct net_device *dev)
921 struct tun_struct *tun = netdev_priv(dev);
923 switch (tun->flags & TUN_TYPE_MASK) {
925 dev->netdev_ops = &tun_netdev_ops;
927 /* Point-to-Point TUN Device */
928 dev->hard_header_len = 0;
932 /* Zero header length */
933 dev->type = ARPHRD_NONE;
934 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
935 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
939 dev->netdev_ops = &tap_netdev_ops;
940 /* Ethernet TAP Device */
942 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
943 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
945 eth_hw_addr_random(dev);
947 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
952 /* Character device part */
955 static unsigned int tun_chr_poll(struct file *file, poll_table *wait)
957 struct tun_file *tfile = file->private_data;
958 struct tun_struct *tun = __tun_get(tfile);
960 unsigned int mask = 0;
965 sk = tfile->socket.sk;
967 tun_debug(KERN_INFO, tun, "tun_chr_poll\n");
969 poll_wait(file, sk_sleep(sk), wait);
971 if (!skb_queue_empty(&sk->sk_receive_queue))
972 mask |= POLLIN | POLLRDNORM;
974 if (sock_writeable(sk) ||
975 (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
977 mask |= POLLOUT | POLLWRNORM;
979 if (tun->dev->reg_state != NETREG_REGISTERED)
986 /* prepad is the amount to reserve at front. len is length after that.
987 * linear is a hint as to how much to copy (usually headers). */
988 static struct sk_buff *tun_alloc_skb(struct tun_file *tfile,
989 size_t prepad, size_t len,
990 size_t linear, int noblock)
992 struct sock *sk = tfile->socket.sk;
996 /* Under a page? Don't bother with paged skb. */
997 if (prepad + len < PAGE_SIZE || !linear)
1000 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
1003 return ERR_PTR(err);
1005 skb_reserve(skb, prepad);
1006 skb_put(skb, linear);
1007 skb->data_len = len - linear;
1008 skb->len += len - linear;
1013 /* Get packet from user space buffer */
1014 static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
1015 void *msg_control, const struct iovec *iv,
1016 size_t total_len, size_t count, int noblock)
1018 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
1019 struct sk_buff *skb;
1020 size_t len = total_len, align = NET_SKB_PAD, linear;
1021 struct virtio_net_hdr gso = { 0 };
1025 bool zerocopy = false;
1029 if (!(tun->flags & TUN_NO_PI)) {
1030 if (len < sizeof(pi))
1034 if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
1036 offset += sizeof(pi);
1039 if (tun->flags & TUN_VNET_HDR) {
1040 if (len < tun->vnet_hdr_sz)
1042 len -= tun->vnet_hdr_sz;
1044 if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
1047 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
1048 gso.csum_start + gso.csum_offset + 2 > gso.hdr_len)
1049 gso.hdr_len = gso.csum_start + gso.csum_offset + 2;
1051 if (gso.hdr_len > len)
1053 offset += tun->vnet_hdr_sz;
1056 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
1057 align += NET_IP_ALIGN;
1058 if (unlikely(len < ETH_HLEN ||
1059 (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
1063 good_linear = SKB_MAX_HEAD(align);
1066 /* There are 256 bytes to be copied in skb, so there is
1067 * enough room for skb expand head in case it is used.
1068 * The rest of the buffer is mapped from userspace.
1070 copylen = gso.hdr_len ? gso.hdr_len : GOODCOPY_LEN;
1071 if (copylen > good_linear)
1072 copylen = good_linear;
1074 if (iov_pages(iv, offset + copylen, count) <= MAX_SKB_FRAGS)
1080 if (gso.hdr_len > good_linear)
1081 linear = good_linear;
1083 linear = gso.hdr_len;
1086 skb = tun_alloc_skb(tfile, align, copylen, linear, noblock);
1088 if (PTR_ERR(skb) != -EAGAIN)
1089 tun->dev->stats.rx_dropped++;
1090 return PTR_ERR(skb);
1094 err = zerocopy_sg_from_iovec(skb, iv, offset, count);
1096 err = skb_copy_datagram_from_iovec(skb, 0, iv, offset, len);
1097 if (!err && msg_control) {
1098 struct ubuf_info *uarg = msg_control;
1099 uarg->callback(uarg, false);
1104 tun->dev->stats.rx_dropped++;
1109 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
1110 if (!skb_partial_csum_set(skb, gso.csum_start,
1112 tun->dev->stats.rx_frame_errors++;
1118 switch (tun->flags & TUN_TYPE_MASK) {
1120 if (tun->flags & TUN_NO_PI) {
1121 switch (skb->data[0] & 0xf0) {
1123 pi.proto = htons(ETH_P_IP);
1126 pi.proto = htons(ETH_P_IPV6);
1129 tun->dev->stats.rx_dropped++;
1135 skb_reset_mac_header(skb);
1136 skb->protocol = pi.proto;
1137 skb->dev = tun->dev;
1140 skb->protocol = eth_type_trans(skb, tun->dev);
1144 skb_reset_network_header(skb);
1146 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
1148 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
1149 case VIRTIO_NET_HDR_GSO_TCPV4:
1150 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
1152 case VIRTIO_NET_HDR_GSO_TCPV6:
1153 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
1155 case VIRTIO_NET_HDR_GSO_UDP:
1161 netdev_warn(tun->dev,
1162 "%s: using disabled UFO feature; please fix this program\n",
1165 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
1166 if (skb->protocol == htons(ETH_P_IPV6))
1167 ipv6_proxy_select_ident(skb);
1171 tun->dev->stats.rx_frame_errors++;
1176 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
1177 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
1179 skb_shinfo(skb)->gso_size = gso.gso_size;
1180 if (skb_shinfo(skb)->gso_size == 0) {
1181 tun->dev->stats.rx_frame_errors++;
1186 /* Header must be checked, and gso_segs computed. */
1187 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
1188 skb_shinfo(skb)->gso_segs = 0;
1191 /* copy skb_ubuf_info for callback when skb has no error */
1193 skb_shinfo(skb)->destructor_arg = msg_control;
1194 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
1195 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
1198 skb_probe_transport_header(skb, 0);
1200 rxhash = skb_get_hash(skb);
1203 tun->dev->stats.rx_packets++;
1204 tun->dev->stats.rx_bytes += len;
1206 tun_flow_update(tun, rxhash, tfile);
1210 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
1211 unsigned long count, loff_t pos)
1213 struct file *file = iocb->ki_filp;
1214 struct tun_struct *tun = tun_get(file);
1215 struct tun_file *tfile = file->private_data;
1221 tun_debug(KERN_INFO, tun, "tun_chr_write %ld\n", count);
1223 result = tun_get_user(tun, tfile, NULL, iv, iov_length(iv, count),
1224 count, file->f_flags & O_NONBLOCK);
1230 /* Put packet to the user space buffer */
1231 static ssize_t tun_put_user(struct tun_struct *tun,
1232 struct tun_file *tfile,
1233 struct sk_buff *skb,
1234 struct iov_iter *iter)
1236 struct tun_pi pi = { 0, skb->protocol };
1240 int vnet_hdr_sz = 0;
1242 if (vlan_tx_tag_present(skb))
1243 vlan_hlen = VLAN_HLEN;
1245 if (tun->flags & TUN_VNET_HDR)
1246 vnet_hdr_sz = tun->vnet_hdr_sz;
1248 total = skb->len + vlan_hlen + vnet_hdr_sz;
1250 if (!(tun->flags & TUN_NO_PI)) {
1251 if (iov_iter_count(iter) < sizeof(pi))
1254 total += sizeof(pi);
1255 if (iov_iter_count(iter) < total) {
1256 /* Packet will be striped */
1257 pi.flags |= TUN_PKT_STRIP;
1260 if (copy_to_iter(&pi, sizeof(pi), iter) != sizeof(pi))
1265 struct virtio_net_hdr gso = { 0 }; /* no info leak */
1266 if (iov_iter_count(iter) < vnet_hdr_sz)
1269 if (skb_is_gso(skb)) {
1270 struct skb_shared_info *sinfo = skb_shinfo(skb);
1272 /* This is a hint as to how much should be linear. */
1273 gso.hdr_len = skb_headlen(skb);
1274 gso.gso_size = sinfo->gso_size;
1275 if (sinfo->gso_type & SKB_GSO_TCPV4)
1276 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
1277 else if (sinfo->gso_type & SKB_GSO_TCPV6)
1278 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
1280 pr_err("unexpected GSO type: "
1281 "0x%x, gso_size %d, hdr_len %d\n",
1282 sinfo->gso_type, gso.gso_size,
1284 print_hex_dump(KERN_ERR, "tun: ",
1287 min((int)gso.hdr_len, 64), true);
1291 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
1292 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
1294 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
1296 if (skb->ip_summed == CHECKSUM_PARTIAL) {
1297 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
1298 gso.csum_start = skb_checksum_start_offset(skb) +
1300 gso.csum_offset = skb->csum_offset;
1301 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
1302 gso.flags = VIRTIO_NET_HDR_F_DATA_VALID;
1303 } /* else everything is zero */
1305 if (copy_to_iter(&gso, sizeof(gso), iter) != sizeof(gso))
1312 __be16 h_vlan_proto;
1316 veth.h_vlan_proto = skb->vlan_proto;
1317 veth.h_vlan_TCI = htons(vlan_tx_tag_get(skb));
1319 vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto);
1321 ret = skb_copy_datagram_iter(skb, 0, iter, vlan_offset);
1322 if (ret || !iov_iter_count(iter))
1325 ret = copy_to_iter(&veth, sizeof(veth), iter);
1326 if (ret != sizeof(veth) || !iov_iter_count(iter))
1330 skb_copy_datagram_iter(skb, vlan_offset, iter, skb->len - vlan_offset);
1333 tun->dev->stats.tx_packets++;
1334 tun->dev->stats.tx_bytes += skb->len + vlan_hlen;
1339 static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
1340 const struct iovec *iv, unsigned long segs,
1341 ssize_t len, int noblock)
1343 struct sk_buff *skb;
1345 int peeked, err, off = 0;
1346 struct iov_iter iter;
1348 tun_debug(KERN_INFO, tun, "tun_do_read\n");
1353 if (tun->dev->reg_state != NETREG_REGISTERED)
1356 /* Read frames from queue */
1357 skb = __skb_recv_datagram(tfile->socket.sk, noblock ? MSG_DONTWAIT : 0,
1358 &peeked, &off, &err);
1362 iov_iter_init(&iter, READ, iv, segs, len);
1363 ret = tun_put_user(tun, tfile, skb, &iter);
1369 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
1370 unsigned long count, loff_t pos)
1372 struct file *file = iocb->ki_filp;
1373 struct tun_file *tfile = file->private_data;
1374 struct tun_struct *tun = __tun_get(tfile);
1379 len = iov_length(iv, count);
1385 ret = tun_do_read(tun, tfile, iv, count, len,
1386 file->f_flags & O_NONBLOCK);
1387 ret = min_t(ssize_t, ret, len);
1395 static void tun_free_netdev(struct net_device *dev)
1397 struct tun_struct *tun = netdev_priv(dev);
1399 BUG_ON(!(list_empty(&tun->disabled)));
1400 tun_flow_uninit(tun);
1401 security_tun_dev_free_security(tun->security);
1405 static void tun_setup(struct net_device *dev)
1407 struct tun_struct *tun = netdev_priv(dev);
1409 tun->owner = INVALID_UID;
1410 tun->group = INVALID_GID;
1412 dev->ethtool_ops = &tun_ethtool_ops;
1413 dev->destructor = tun_free_netdev;
1416 /* Trivial set of netlink ops to allow deleting tun or tap
1417 * device with netlink.
1419 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
1424 static struct rtnl_link_ops tun_link_ops __read_mostly = {
1426 .priv_size = sizeof(struct tun_struct),
1428 .validate = tun_validate,
1431 static void tun_sock_write_space(struct sock *sk)
1433 struct tun_file *tfile;
1434 wait_queue_head_t *wqueue;
1436 if (!sock_writeable(sk))
1439 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
1442 wqueue = sk_sleep(sk);
1443 if (wqueue && waitqueue_active(wqueue))
1444 wake_up_interruptible_sync_poll(wqueue, POLLOUT |
1445 POLLWRNORM | POLLWRBAND);
1447 tfile = container_of(sk, struct tun_file, sk);
1448 kill_fasync(&tfile->fasync, SIGIO, POLL_OUT);
1451 static int tun_sendmsg(struct kiocb *iocb, struct socket *sock,
1452 struct msghdr *m, size_t total_len)
1455 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1456 struct tun_struct *tun = __tun_get(tfile);
1460 ret = tun_get_user(tun, tfile, m->msg_control, m->msg_iov, total_len,
1461 m->msg_iovlen, m->msg_flags & MSG_DONTWAIT);
1466 static int tun_recvmsg(struct kiocb *iocb, struct socket *sock,
1467 struct msghdr *m, size_t total_len,
1470 struct tun_file *tfile = container_of(sock, struct tun_file, socket);
1471 struct tun_struct *tun = __tun_get(tfile);
1477 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC|MSG_ERRQUEUE)) {
1481 if (flags & MSG_ERRQUEUE) {
1482 ret = sock_recv_errqueue(sock->sk, m, total_len,
1483 SOL_PACKET, TUN_TX_TIMESTAMP);
1486 ret = tun_do_read(tun, tfile, m->msg_iov, m->msg_iovlen, total_len,
1487 flags & MSG_DONTWAIT);
1488 if (ret > total_len) {
1489 m->msg_flags |= MSG_TRUNC;
1490 ret = flags & MSG_TRUNC ? ret : total_len;
1497 static int tun_release(struct socket *sock)
1504 /* Ops structure to mimic raw sockets with tun */
1505 static const struct proto_ops tun_socket_ops = {
1506 .sendmsg = tun_sendmsg,
1507 .recvmsg = tun_recvmsg,
1508 .release = tun_release,
1511 static struct proto tun_proto = {
1513 .owner = THIS_MODULE,
1514 .obj_size = sizeof(struct tun_file),
1517 static int tun_flags(struct tun_struct *tun)
1521 if (tun->flags & TUN_TUN_DEV)
1526 if (tun->flags & TUN_NO_PI)
1529 /* This flag has no real effect. We track the value for backwards
1532 if (tun->flags & TUN_ONE_QUEUE)
1533 flags |= IFF_ONE_QUEUE;
1535 if (tun->flags & TUN_VNET_HDR)
1536 flags |= IFF_VNET_HDR;
1538 if (tun->flags & TUN_TAP_MQ)
1539 flags |= IFF_MULTI_QUEUE;
1541 if (tun->flags & TUN_PERSIST)
1542 flags |= IFF_PERSIST;
1547 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
1550 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1551 return sprintf(buf, "0x%x\n", tun_flags(tun));
1554 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
1557 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1558 return uid_valid(tun->owner)?
1559 sprintf(buf, "%u\n",
1560 from_kuid_munged(current_user_ns(), tun->owner)):
1561 sprintf(buf, "-1\n");
1564 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
1567 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1568 return gid_valid(tun->group) ?
1569 sprintf(buf, "%u\n",
1570 from_kgid_munged(current_user_ns(), tun->group)):
1571 sprintf(buf, "-1\n");
1574 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
1575 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
1576 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
1578 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
1580 struct tun_struct *tun;
1581 struct tun_file *tfile = file->private_data;
1582 struct net_device *dev;
1585 if (tfile->detached)
1588 dev = __dev_get_by_name(net, ifr->ifr_name);
1590 if (ifr->ifr_flags & IFF_TUN_EXCL)
1592 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
1593 tun = netdev_priv(dev);
1594 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
1595 tun = netdev_priv(dev);
1599 if (!!(ifr->ifr_flags & IFF_MULTI_QUEUE) !=
1600 !!(tun->flags & TUN_TAP_MQ))
1603 if (tun_not_capable(tun))
1605 err = security_tun_dev_open(tun->security);
1609 err = tun_attach(tun, file, ifr->ifr_flags & IFF_NOFILTER);
1613 if (tun->flags & TUN_TAP_MQ &&
1614 (tun->numqueues + tun->numdisabled > 1)) {
1615 /* One or more queue has already been attached, no need
1616 * to initialize the device again.
1623 unsigned long flags = 0;
1624 int queues = ifr->ifr_flags & IFF_MULTI_QUEUE ?
1627 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1629 err = security_tun_dev_create();
1634 if (ifr->ifr_flags & IFF_TUN) {
1636 flags |= TUN_TUN_DEV;
1638 } else if (ifr->ifr_flags & IFF_TAP) {
1640 flags |= TUN_TAP_DEV;
1646 name = ifr->ifr_name;
1648 dev = alloc_netdev_mqs(sizeof(struct tun_struct), name,
1649 NET_NAME_UNKNOWN, tun_setup, queues,
1655 dev_net_set(dev, net);
1656 dev->rtnl_link_ops = &tun_link_ops;
1657 dev->ifindex = tfile->ifindex;
1659 tun = netdev_priv(dev);
1662 tun->txflt.count = 0;
1663 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
1665 tun->filter_attached = false;
1666 tun->sndbuf = tfile->socket.sk->sk_sndbuf;
1668 spin_lock_init(&tun->lock);
1670 err = security_tun_dev_alloc_security(&tun->security);
1677 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
1678 TUN_USER_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
1679 NETIF_F_HW_VLAN_STAG_TX;
1680 dev->features = dev->hw_features;
1681 dev->vlan_features = dev->features &
1682 ~(NETIF_F_HW_VLAN_CTAG_TX |
1683 NETIF_F_HW_VLAN_STAG_TX);
1685 INIT_LIST_HEAD(&tun->disabled);
1686 err = tun_attach(tun, file, false);
1690 err = register_netdevice(tun->dev);
1694 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
1695 device_create_file(&tun->dev->dev, &dev_attr_owner) ||
1696 device_create_file(&tun->dev->dev, &dev_attr_group))
1697 pr_err("Failed to create tun sysfs files\n");
1700 netif_carrier_on(tun->dev);
1702 tun_debug(KERN_INFO, tun, "tun_set_iff\n");
1704 if (ifr->ifr_flags & IFF_NO_PI)
1705 tun->flags |= TUN_NO_PI;
1707 tun->flags &= ~TUN_NO_PI;
1709 /* This flag has no real effect. We track the value for backwards
1712 if (ifr->ifr_flags & IFF_ONE_QUEUE)
1713 tun->flags |= TUN_ONE_QUEUE;
1715 tun->flags &= ~TUN_ONE_QUEUE;
1717 if (ifr->ifr_flags & IFF_VNET_HDR)
1718 tun->flags |= TUN_VNET_HDR;
1720 tun->flags &= ~TUN_VNET_HDR;
1722 if (ifr->ifr_flags & IFF_MULTI_QUEUE)
1723 tun->flags |= TUN_TAP_MQ;
1725 tun->flags &= ~TUN_TAP_MQ;
1727 /* Make sure persistent devices do not get stuck in
1730 if (netif_running(tun->dev))
1731 netif_tx_wake_all_queues(tun->dev);
1733 strcpy(ifr->ifr_name, tun->dev->name);
1737 tun_detach_all(dev);
1739 tun_flow_uninit(tun);
1740 security_tun_dev_free_security(tun->security);
1746 static void tun_get_iff(struct net *net, struct tun_struct *tun,
1749 tun_debug(KERN_INFO, tun, "tun_get_iff\n");
1751 strcpy(ifr->ifr_name, tun->dev->name);
1753 ifr->ifr_flags = tun_flags(tun);
1757 /* This is like a cut-down ethtool ops, except done via tun fd so no
1758 * privs required. */
1759 static int set_offload(struct tun_struct *tun, unsigned long arg)
1761 netdev_features_t features = 0;
1763 if (arg & TUN_F_CSUM) {
1764 features |= NETIF_F_HW_CSUM;
1767 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1768 if (arg & TUN_F_TSO_ECN) {
1769 features |= NETIF_F_TSO_ECN;
1770 arg &= ~TUN_F_TSO_ECN;
1772 if (arg & TUN_F_TSO4)
1773 features |= NETIF_F_TSO;
1774 if (arg & TUN_F_TSO6)
1775 features |= NETIF_F_TSO6;
1776 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1780 /* This gives the user a way to test for new features in future by
1781 * trying to set them. */
1785 tun->set_features = features;
1786 netdev_update_features(tun->dev);
1791 static void tun_detach_filter(struct tun_struct *tun, int n)
1794 struct tun_file *tfile;
1796 for (i = 0; i < n; i++) {
1797 tfile = rtnl_dereference(tun->tfiles[i]);
1798 sk_detach_filter(tfile->socket.sk);
1801 tun->filter_attached = false;
1804 static int tun_attach_filter(struct tun_struct *tun)
1807 struct tun_file *tfile;
1809 for (i = 0; i < tun->numqueues; i++) {
1810 tfile = rtnl_dereference(tun->tfiles[i]);
1811 ret = sk_attach_filter(&tun->fprog, tfile->socket.sk);
1813 tun_detach_filter(tun, i);
1818 tun->filter_attached = true;
1822 static void tun_set_sndbuf(struct tun_struct *tun)
1824 struct tun_file *tfile;
1827 for (i = 0; i < tun->numqueues; i++) {
1828 tfile = rtnl_dereference(tun->tfiles[i]);
1829 tfile->socket.sk->sk_sndbuf = tun->sndbuf;
1833 static int tun_set_queue(struct file *file, struct ifreq *ifr)
1835 struct tun_file *tfile = file->private_data;
1836 struct tun_struct *tun;
1841 if (ifr->ifr_flags & IFF_ATTACH_QUEUE) {
1842 tun = tfile->detached;
1847 ret = security_tun_dev_attach_queue(tun->security);
1850 ret = tun_attach(tun, file, false);
1851 } else if (ifr->ifr_flags & IFF_DETACH_QUEUE) {
1852 tun = rtnl_dereference(tfile->tun);
1853 if (!tun || !(tun->flags & TUN_TAP_MQ) || tfile->detached)
1856 __tun_detach(tfile, false);
1865 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
1866 unsigned long arg, int ifreq_len)
1868 struct tun_file *tfile = file->private_data;
1869 struct tun_struct *tun;
1870 void __user* argp = (void __user*)arg;
1876 unsigned int ifindex;
1879 if (cmd == TUNSETIFF || cmd == TUNSETQUEUE || _IOC_TYPE(cmd) == 0x89) {
1880 if (copy_from_user(&ifr, argp, ifreq_len))
1883 memset(&ifr, 0, sizeof(ifr));
1885 if (cmd == TUNGETFEATURES) {
1886 /* Currently this just means: "what IFF flags are valid?".
1887 * This is needed because we never checked for invalid flags on
1889 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
1890 IFF_VNET_HDR | IFF_MULTI_QUEUE,
1891 (unsigned int __user*)argp);
1892 } else if (cmd == TUNSETQUEUE)
1893 return tun_set_queue(file, &ifr);
1898 tun = __tun_get(tfile);
1899 if (cmd == TUNSETIFF && !tun) {
1900 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1902 ret = tun_set_iff(tfile->net, file, &ifr);
1907 if (copy_to_user(argp, &ifr, ifreq_len))
1911 if (cmd == TUNSETIFINDEX) {
1917 if (copy_from_user(&ifindex, argp, sizeof(ifindex)))
1921 tfile->ifindex = ifindex;
1929 tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %u\n", cmd);
1934 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1936 if (tfile->detached)
1937 ifr.ifr_flags |= IFF_DETACH_QUEUE;
1938 if (!tfile->socket.sk->sk_filter)
1939 ifr.ifr_flags |= IFF_NOFILTER;
1941 if (copy_to_user(argp, &ifr, ifreq_len))
1946 /* Disable/Enable checksum */
1948 /* [unimplemented] */
1949 tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n",
1950 arg ? "disabled" : "enabled");
1954 /* Disable/Enable persist mode. Keep an extra reference to the
1955 * module to prevent the module being unprobed.
1957 if (arg && !(tun->flags & TUN_PERSIST)) {
1958 tun->flags |= TUN_PERSIST;
1959 __module_get(THIS_MODULE);
1961 if (!arg && (tun->flags & TUN_PERSIST)) {
1962 tun->flags &= ~TUN_PERSIST;
1963 module_put(THIS_MODULE);
1966 tun_debug(KERN_INFO, tun, "persist %s\n",
1967 arg ? "enabled" : "disabled");
1971 /* Set owner of the device */
1972 owner = make_kuid(current_user_ns(), arg);
1973 if (!uid_valid(owner)) {
1978 tun_debug(KERN_INFO, tun, "owner set to %u\n",
1979 from_kuid(&init_user_ns, tun->owner));
1983 /* Set group of the device */
1984 group = make_kgid(current_user_ns(), arg);
1985 if (!gid_valid(group)) {
1990 tun_debug(KERN_INFO, tun, "group set to %u\n",
1991 from_kgid(&init_user_ns, tun->group));
1995 /* Only allow setting the type when the interface is down */
1996 if (tun->dev->flags & IFF_UP) {
1997 tun_debug(KERN_INFO, tun,
1998 "Linktype set failed because interface is up\n");
2001 tun->dev->type = (int) arg;
2002 tun_debug(KERN_INFO, tun, "linktype set to %d\n",
2014 ret = set_offload(tun, arg);
2017 case TUNSETTXFILTER:
2018 /* Can be set only for TAPs */
2020 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
2022 ret = update_filter(&tun->txflt, (void __user *)arg);
2026 /* Get hw address */
2027 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
2028 ifr.ifr_hwaddr.sa_family = tun->dev->type;
2029 if (copy_to_user(argp, &ifr, ifreq_len))
2034 /* Set hw address */
2035 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n",
2036 ifr.ifr_hwaddr.sa_data);
2038 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
2042 sndbuf = tfile->socket.sk->sk_sndbuf;
2043 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
2048 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
2053 tun->sndbuf = sndbuf;
2054 tun_set_sndbuf(tun);
2057 case TUNGETVNETHDRSZ:
2058 vnet_hdr_sz = tun->vnet_hdr_sz;
2059 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
2063 case TUNSETVNETHDRSZ:
2064 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
2068 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
2073 tun->vnet_hdr_sz = vnet_hdr_sz;
2076 case TUNATTACHFILTER:
2077 /* Can be set only for TAPs */
2079 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
2082 if (copy_from_user(&tun->fprog, argp, sizeof(tun->fprog)))
2085 ret = tun_attach_filter(tun);
2088 case TUNDETACHFILTER:
2089 /* Can be set only for TAPs */
2091 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
2094 tun_detach_filter(tun, tun->numqueues);
2099 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
2102 if (copy_to_user(argp, &tun->fprog, sizeof(tun->fprog)))
2119 static long tun_chr_ioctl(struct file *file,
2120 unsigned int cmd, unsigned long arg)
2122 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
2125 #ifdef CONFIG_COMPAT
2126 static long tun_chr_compat_ioctl(struct file *file,
2127 unsigned int cmd, unsigned long arg)
2132 case TUNSETTXFILTER:
2137 arg = (unsigned long)compat_ptr(arg);
2140 arg = (compat_ulong_t)arg;
2145 * compat_ifreq is shorter than ifreq, so we must not access beyond
2146 * the end of that structure. All fields that are used in this
2147 * driver are compatible though, we don't need to convert the
2150 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
2152 #endif /* CONFIG_COMPAT */
2154 static int tun_chr_fasync(int fd, struct file *file, int on)
2156 struct tun_file *tfile = file->private_data;
2159 if ((ret = fasync_helper(fd, file, on, &tfile->fasync)) < 0)
2163 __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
2164 tfile->flags |= TUN_FASYNC;
2166 tfile->flags &= ~TUN_FASYNC;
2172 static int tun_chr_open(struct inode *inode, struct file * file)
2174 struct tun_file *tfile;
2176 DBG1(KERN_INFO, "tunX: tun_chr_open\n");
2178 tfile = (struct tun_file *)sk_alloc(&init_net, AF_UNSPEC, GFP_KERNEL,
2182 RCU_INIT_POINTER(tfile->tun, NULL);
2183 tfile->net = get_net(current->nsproxy->net_ns);
2187 init_waitqueue_head(&tfile->wq.wait);
2188 RCU_INIT_POINTER(tfile->socket.wq, &tfile->wq);
2190 tfile->socket.file = file;
2191 tfile->socket.ops = &tun_socket_ops;
2193 sock_init_data(&tfile->socket, &tfile->sk);
2194 sk_change_net(&tfile->sk, tfile->net);
2196 tfile->sk.sk_write_space = tun_sock_write_space;
2197 tfile->sk.sk_sndbuf = INT_MAX;
2199 file->private_data = tfile;
2200 set_bit(SOCK_EXTERNALLY_ALLOCATED, &tfile->socket.flags);
2201 INIT_LIST_HEAD(&tfile->next);
2203 sock_set_flag(&tfile->sk, SOCK_ZEROCOPY);
2208 static int tun_chr_close(struct inode *inode, struct file *file)
2210 struct tun_file *tfile = file->private_data;
2211 struct net *net = tfile->net;
2213 tun_detach(tfile, true);
2219 #ifdef CONFIG_PROC_FS
2220 static int tun_chr_show_fdinfo(struct seq_file *m, struct file *f)
2222 struct tun_struct *tun;
2225 memset(&ifr, 0, sizeof(ifr));
2230 tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
2236 return seq_printf(m, "iff:\t%s\n", ifr.ifr_name);
2240 static const struct file_operations tun_fops = {
2241 .owner = THIS_MODULE,
2242 .llseek = no_llseek,
2243 .read = do_sync_read,
2244 .aio_read = tun_chr_aio_read,
2245 .write = do_sync_write,
2246 .aio_write = tun_chr_aio_write,
2247 .poll = tun_chr_poll,
2248 .unlocked_ioctl = tun_chr_ioctl,
2249 #ifdef CONFIG_COMPAT
2250 .compat_ioctl = tun_chr_compat_ioctl,
2252 .open = tun_chr_open,
2253 .release = tun_chr_close,
2254 .fasync = tun_chr_fasync,
2255 #ifdef CONFIG_PROC_FS
2256 .show_fdinfo = tun_chr_show_fdinfo,
2260 static struct miscdevice tun_miscdev = {
2263 .nodename = "net/tun",
2267 /* ethtool interface */
2269 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
2272 cmd->advertising = 0;
2273 ethtool_cmd_speed_set(cmd, SPEED_10);
2274 cmd->duplex = DUPLEX_FULL;
2275 cmd->port = PORT_TP;
2276 cmd->phy_address = 0;
2277 cmd->transceiver = XCVR_INTERNAL;
2278 cmd->autoneg = AUTONEG_DISABLE;
2284 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
2286 struct tun_struct *tun = netdev_priv(dev);
2288 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
2289 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
2291 switch (tun->flags & TUN_TYPE_MASK) {
2293 strlcpy(info->bus_info, "tun", sizeof(info->bus_info));
2296 strlcpy(info->bus_info, "tap", sizeof(info->bus_info));
2301 static u32 tun_get_msglevel(struct net_device *dev)
2304 struct tun_struct *tun = netdev_priv(dev);
2311 static void tun_set_msglevel(struct net_device *dev, u32 value)
2314 struct tun_struct *tun = netdev_priv(dev);
2319 static const struct ethtool_ops tun_ethtool_ops = {
2320 .get_settings = tun_get_settings,
2321 .get_drvinfo = tun_get_drvinfo,
2322 .get_msglevel = tun_get_msglevel,
2323 .set_msglevel = tun_set_msglevel,
2324 .get_link = ethtool_op_get_link,
2325 .get_ts_info = ethtool_op_get_ts_info,
2329 static int __init tun_init(void)
2333 pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
2334 pr_info("%s\n", DRV_COPYRIGHT);
2336 ret = rtnl_link_register(&tun_link_ops);
2338 pr_err("Can't register link_ops\n");
2342 ret = misc_register(&tun_miscdev);
2344 pr_err("Can't register misc device %d\n", TUN_MINOR);
2349 rtnl_link_unregister(&tun_link_ops);
2354 static void tun_cleanup(void)
2356 misc_deregister(&tun_miscdev);
2357 rtnl_link_unregister(&tun_link_ops);
2360 /* Get an underlying socket object from tun file. Returns error unless file is
2361 * attached to a device. The returned object works like a packet socket, it
2362 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
2363 * holding a reference to the file for as long as the socket is in use. */
2364 struct socket *tun_get_socket(struct file *file)
2366 struct tun_file *tfile;
2367 if (file->f_op != &tun_fops)
2368 return ERR_PTR(-EINVAL);
2369 tfile = file->private_data;
2371 return ERR_PTR(-EBADFD);
2372 return &tfile->socket;
2374 EXPORT_SYMBOL_GPL(tun_get_socket);
2376 module_init(tun_init);
2377 module_exit(tun_cleanup);
2378 MODULE_DESCRIPTION(DRV_DESCRIPTION);
2379 MODULE_AUTHOR(DRV_COPYRIGHT);
2380 MODULE_LICENSE("GPL");
2381 MODULE_ALIAS_MISCDEV(TUN_MINOR);
2382 MODULE_ALIAS("devname:net/tun");