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 random_ether_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 DRV_NAME "tun"
38 #define DRV_VERSION "1.6"
39 #define DRV_DESCRIPTION "Universal TUN/TAP device driver"
40 #define DRV_COPYRIGHT "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>"
42 #include <linux/module.h>
43 #include <linux/errno.h>
44 #include <linux/kernel.h>
45 #include <linux/major.h>
46 #include <linux/slab.h>
47 #include <linux/poll.h>
48 #include <linux/fcntl.h>
49 #include <linux/init.h>
50 #include <linux/skbuff.h>
51 #include <linux/netdevice.h>
52 #include <linux/etherdevice.h>
53 #include <linux/miscdevice.h>
54 #include <linux/ethtool.h>
55 #include <linux/rtnetlink.h>
56 #include <linux/compat.h>
58 #include <linux/if_arp.h>
59 #include <linux/if_ether.h>
60 #include <linux/if_tun.h>
61 #include <linux/crc32.h>
62 #include <linux/nsproxy.h>
63 #include <linux/virtio_net.h>
64 #include <net/net_namespace.h>
65 #include <net/netns/generic.h>
66 #include <net/rtnetlink.h>
69 #include <asm/system.h>
70 #include <asm/uaccess.h>
72 /* Uncomment to enable debugging */
73 /* #define TUN_DEBUG 1 */
78 #define DBG if(tun->debug)printk
79 #define DBG1 if(debug==2)printk
85 #define FLT_EXACT_COUNT 8
87 unsigned int count; /* Number of addrs. Zero means disabled */
88 u32 mask[2]; /* Mask of the hashed addrs */
89 unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN];
94 struct tun_struct *tun;
101 struct tun_file *tfile;
106 struct net_device *dev;
107 struct fasync_struct *fasync;
109 struct tap_filter txflt;
110 struct socket socket;
119 struct tun_struct *tun;
122 static inline struct tun_sock *tun_sk(struct sock *sk)
124 return container_of(sk, struct tun_sock, sk);
127 static int tun_attach(struct tun_struct *tun, struct file *file)
129 struct tun_file *tfile = file->private_data;
134 netif_tx_lock_bh(tun->dev);
147 tun->socket.file = file;
149 sock_hold(tun->socket.sk);
150 atomic_inc(&tfile->count);
153 netif_tx_unlock_bh(tun->dev);
157 static void __tun_detach(struct tun_struct *tun)
159 /* Detach from net device */
160 netif_tx_lock_bh(tun->dev);
162 tun->socket.file = NULL;
163 netif_tx_unlock_bh(tun->dev);
165 /* Drop read queue */
166 skb_queue_purge(&tun->socket.sk->sk_receive_queue);
168 /* Drop the extra count on the net device */
172 static void tun_detach(struct tun_struct *tun)
179 static struct tun_struct *__tun_get(struct tun_file *tfile)
181 struct tun_struct *tun = NULL;
183 if (atomic_inc_not_zero(&tfile->count))
189 static struct tun_struct *tun_get(struct file *file)
191 return __tun_get(file->private_data);
194 static void tun_put(struct tun_struct *tun)
196 struct tun_file *tfile = tun->tfile;
198 if (atomic_dec_and_test(&tfile->count))
199 tun_detach(tfile->tun);
203 static void addr_hash_set(u32 *mask, const u8 *addr)
205 int n = ether_crc(ETH_ALEN, addr) >> 26;
206 mask[n >> 5] |= (1 << (n & 31));
209 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
211 int n = ether_crc(ETH_ALEN, addr) >> 26;
212 return mask[n >> 5] & (1 << (n & 31));
215 static int update_filter(struct tap_filter *filter, void __user *arg)
217 struct { u8 u[ETH_ALEN]; } *addr;
218 struct tun_filter uf;
219 int err, alen, n, nexact;
221 if (copy_from_user(&uf, arg, sizeof(uf)))
230 alen = ETH_ALEN * uf.count;
231 addr = kmalloc(alen, GFP_KERNEL);
235 if (copy_from_user(addr, arg + sizeof(uf), alen)) {
240 /* The filter is updated without holding any locks. Which is
241 * perfectly safe. We disable it first and in the worst
242 * case we'll accept a few undesired packets. */
246 /* Use first set of addresses as an exact filter */
247 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
248 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
252 /* Remaining multicast addresses are hashed,
253 * unicast will leave the filter disabled. */
254 memset(filter->mask, 0, sizeof(filter->mask));
255 for (; n < uf.count; n++) {
256 if (!is_multicast_ether_addr(addr[n].u)) {
257 err = 0; /* no filter */
260 addr_hash_set(filter->mask, addr[n].u);
263 /* For ALLMULTI just set the mask to all ones.
264 * This overrides the mask populated above. */
265 if ((uf.flags & TUN_FLT_ALLMULTI))
266 memset(filter->mask, ~0, sizeof(filter->mask));
268 /* Now enable the filter */
270 filter->count = nexact;
272 /* Return the number of exact filters */
280 /* Returns: 0 - drop, !=0 - accept */
281 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
283 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
285 struct ethhdr *eh = (struct ethhdr *) skb->data;
289 for (i = 0; i < filter->count; i++)
290 if (!compare_ether_addr(eh->h_dest, filter->addr[i]))
293 /* Inexact match (multicast only) */
294 if (is_multicast_ether_addr(eh->h_dest))
295 return addr_hash_test(filter->mask, eh->h_dest);
301 * Checks whether the packet is accepted or not.
302 * Returns: 0 - drop, !=0 - accept
304 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
309 return run_filter(filter, skb);
312 /* Network device part of the driver */
314 static const struct ethtool_ops tun_ethtool_ops;
316 /* Net device detach from fd. */
317 static void tun_net_uninit(struct net_device *dev)
319 struct tun_struct *tun = netdev_priv(dev);
320 struct tun_file *tfile = tun->tfile;
322 /* Inform the methods they need to stop using the dev.
325 wake_up_all(&tun->socket.wait);
326 if (atomic_dec_and_test(&tfile->count))
331 static void tun_free_netdev(struct net_device *dev)
333 struct tun_struct *tun = netdev_priv(dev);
335 sock_put(tun->socket.sk);
338 /* Net device open. */
339 static int tun_net_open(struct net_device *dev)
341 netif_start_queue(dev);
345 /* Net device close. */
346 static int tun_net_close(struct net_device *dev)
348 netif_stop_queue(dev);
352 /* Net device start xmit */
353 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
355 struct tun_struct *tun = netdev_priv(dev);
357 DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len);
359 /* Drop packet if interface is not attached */
363 /* Drop if the filter does not like it.
364 * This is a noop if the filter is disabled.
365 * Filter can be enabled only for the TAP devices. */
366 if (!check_filter(&tun->txflt, skb))
369 if (skb_queue_len(&tun->socket.sk->sk_receive_queue) >= dev->tx_queue_len) {
370 if (!(tun->flags & TUN_ONE_QUEUE)) {
371 /* Normal queueing mode. */
372 /* Packet scheduler handles dropping of further packets. */
373 netif_stop_queue(dev);
375 /* We won't see all dropped packets individually, so overrun
376 * error is more appropriate. */
377 dev->stats.tx_fifo_errors++;
379 /* Single queue mode.
380 * Driver handles dropping of all packets itself. */
386 skb_queue_tail(&tun->socket.sk->sk_receive_queue, skb);
387 dev->trans_start = jiffies;
389 /* Notify and wake up reader process */
390 if (tun->flags & TUN_FASYNC)
391 kill_fasync(&tun->fasync, SIGIO, POLL_IN);
392 wake_up_interruptible_poll(&tun->socket.wait, POLLIN |
393 POLLRDNORM | POLLRDBAND);
397 dev->stats.tx_dropped++;
402 static void tun_net_mclist(struct net_device *dev)
405 * This callback is supposed to deal with mc filter in
406 * _rx_ path and has nothing to do with the _tx_ path.
407 * In rx path we always accept everything userspace gives us.
413 #define MAX_MTU 65535
416 tun_net_change_mtu(struct net_device *dev, int new_mtu)
418 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
424 static const struct net_device_ops tun_netdev_ops = {
425 .ndo_uninit = tun_net_uninit,
426 .ndo_open = tun_net_open,
427 .ndo_stop = tun_net_close,
428 .ndo_start_xmit = tun_net_xmit,
429 .ndo_change_mtu = tun_net_change_mtu,
432 static const struct net_device_ops tap_netdev_ops = {
433 .ndo_uninit = tun_net_uninit,
434 .ndo_open = tun_net_open,
435 .ndo_stop = tun_net_close,
436 .ndo_start_xmit = tun_net_xmit,
437 .ndo_change_mtu = tun_net_change_mtu,
438 .ndo_set_multicast_list = tun_net_mclist,
439 .ndo_set_mac_address = eth_mac_addr,
440 .ndo_validate_addr = eth_validate_addr,
443 /* Initialize net device. */
444 static void tun_net_init(struct net_device *dev)
446 struct tun_struct *tun = netdev_priv(dev);
448 switch (tun->flags & TUN_TYPE_MASK) {
450 dev->netdev_ops = &tun_netdev_ops;
452 /* Point-to-Point TUN Device */
453 dev->hard_header_len = 0;
457 /* Zero header length */
458 dev->type = ARPHRD_NONE;
459 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
460 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
464 dev->netdev_ops = &tap_netdev_ops;
465 /* Ethernet TAP Device */
468 random_ether_addr(dev->dev_addr);
470 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
475 /* Character device part */
478 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
480 struct tun_file *tfile = file->private_data;
481 struct tun_struct *tun = __tun_get(tfile);
483 unsigned int mask = 0;
490 DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name);
492 poll_wait(file, &tun->socket.wait, wait);
494 if (!skb_queue_empty(&sk->sk_receive_queue))
495 mask |= POLLIN | POLLRDNORM;
497 if (sock_writeable(sk) ||
498 (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
500 mask |= POLLOUT | POLLWRNORM;
502 if (tun->dev->reg_state != NETREG_REGISTERED)
509 /* prepad is the amount to reserve at front. len is length after that.
510 * linear is a hint as to how much to copy (usually headers). */
511 static inline struct sk_buff *tun_alloc_skb(struct tun_struct *tun,
512 size_t prepad, size_t len,
513 size_t linear, int noblock)
515 struct sock *sk = tun->socket.sk;
519 /* Under a page? Don't bother with paged skb. */
520 if (prepad + len < PAGE_SIZE || !linear)
523 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
528 skb_reserve(skb, prepad);
529 skb_put(skb, linear);
530 skb->data_len = len - linear;
531 skb->len += len - linear;
536 /* Get packet from user space buffer */
537 static __inline__ ssize_t tun_get_user(struct tun_struct *tun,
538 const struct iovec *iv, size_t count,
541 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
543 size_t len = count, align = 0;
544 struct virtio_net_hdr gso = { 0 };
547 if (!(tun->flags & TUN_NO_PI)) {
548 if ((len -= sizeof(pi)) > count)
551 if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
553 offset += sizeof(pi);
556 if (tun->flags & TUN_VNET_HDR) {
557 if ((len -= sizeof(gso)) > count)
560 if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
563 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
564 gso.csum_start + gso.csum_offset + 2 > gso.hdr_len)
565 gso.hdr_len = gso.csum_start + gso.csum_offset + 2;
567 if (gso.hdr_len > len)
569 offset += sizeof(gso);
572 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
573 align = NET_IP_ALIGN;
574 if (unlikely(len < ETH_HLEN ||
575 (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
579 skb = tun_alloc_skb(tun, align, len, gso.hdr_len, noblock);
581 if (PTR_ERR(skb) != -EAGAIN)
582 tun->dev->stats.rx_dropped++;
586 if (skb_copy_datagram_from_iovec(skb, 0, iv, offset, len)) {
587 tun->dev->stats.rx_dropped++;
592 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
593 if (!skb_partial_csum_set(skb, gso.csum_start,
595 tun->dev->stats.rx_frame_errors++;
599 } else if (tun->flags & TUN_NOCHECKSUM)
600 skb->ip_summed = CHECKSUM_UNNECESSARY;
602 switch (tun->flags & TUN_TYPE_MASK) {
604 if (tun->flags & TUN_NO_PI) {
605 switch (skb->data[0] & 0xf0) {
607 pi.proto = htons(ETH_P_IP);
610 pi.proto = htons(ETH_P_IPV6);
613 tun->dev->stats.rx_dropped++;
619 skb_reset_mac_header(skb);
620 skb->protocol = pi.proto;
624 skb->protocol = eth_type_trans(skb, tun->dev);
628 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
630 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
631 case VIRTIO_NET_HDR_GSO_TCPV4:
632 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
634 case VIRTIO_NET_HDR_GSO_TCPV6:
635 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
637 case VIRTIO_NET_HDR_GSO_UDP:
638 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
641 tun->dev->stats.rx_frame_errors++;
646 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
647 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
649 skb_shinfo(skb)->gso_size = gso.gso_size;
650 if (skb_shinfo(skb)->gso_size == 0) {
651 tun->dev->stats.rx_frame_errors++;
656 /* Header must be checked, and gso_segs computed. */
657 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
658 skb_shinfo(skb)->gso_segs = 0;
663 tun->dev->stats.rx_packets++;
664 tun->dev->stats.rx_bytes += len;
669 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
670 unsigned long count, loff_t pos)
672 struct file *file = iocb->ki_filp;
673 struct tun_struct *tun = tun_get(file);
679 DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);
681 result = tun_get_user(tun, iv, iov_length(iv, count),
682 file->f_flags & O_NONBLOCK);
688 /* Put packet to the user space buffer */
689 static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
691 const struct iovec *iv, int len)
693 struct tun_pi pi = { 0, skb->protocol };
696 if (!(tun->flags & TUN_NO_PI)) {
697 if ((len -= sizeof(pi)) < 0)
700 if (len < skb->len) {
701 /* Packet will be striped */
702 pi.flags |= TUN_PKT_STRIP;
705 if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi)))
710 if (tun->flags & TUN_VNET_HDR) {
711 struct virtio_net_hdr gso = { 0 }; /* no info leak */
712 if ((len -= sizeof(gso)) < 0)
715 if (skb_is_gso(skb)) {
716 struct skb_shared_info *sinfo = skb_shinfo(skb);
718 /* This is a hint as to how much should be linear. */
719 gso.hdr_len = skb_headlen(skb);
720 gso.gso_size = sinfo->gso_size;
721 if (sinfo->gso_type & SKB_GSO_TCPV4)
722 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
723 else if (sinfo->gso_type & SKB_GSO_TCPV6)
724 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
725 else if (sinfo->gso_type & SKB_GSO_UDP)
726 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
729 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
730 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
732 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
734 if (skb->ip_summed == CHECKSUM_PARTIAL) {
735 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
736 gso.csum_start = skb->csum_start - skb_headroom(skb);
737 gso.csum_offset = skb->csum_offset;
738 } /* else everything is zero */
740 if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
743 total += sizeof(gso);
746 len = min_t(int, skb->len, len);
748 skb_copy_datagram_const_iovec(skb, 0, iv, total, len);
751 tun->dev->stats.tx_packets++;
752 tun->dev->stats.tx_bytes += len;
757 static ssize_t tun_do_read(struct tun_struct *tun,
758 struct kiocb *iocb, const struct iovec *iv,
759 ssize_t len, int noblock)
761 DECLARE_WAITQUEUE(wait, current);
765 DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
767 add_wait_queue(&tun->socket.wait, &wait);
769 current->state = TASK_INTERRUPTIBLE;
771 /* Read frames from the queue */
772 if (!(skb=skb_dequeue(&tun->socket.sk->sk_receive_queue))) {
777 if (signal_pending(current)) {
781 if (tun->dev->reg_state != NETREG_REGISTERED) {
786 /* Nothing to read, let's sleep */
790 netif_wake_queue(tun->dev);
792 ret = tun_put_user(tun, skb, iv, len);
797 current->state = TASK_RUNNING;
798 remove_wait_queue(&tun->socket.wait, &wait);
803 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
804 unsigned long count, loff_t pos)
806 struct file *file = iocb->ki_filp;
807 struct tun_file *tfile = file->private_data;
808 struct tun_struct *tun = __tun_get(tfile);
813 len = iov_length(iv, count);
819 ret = tun_do_read(tun, iocb, iv, len, file->f_flags & O_NONBLOCK);
820 ret = min_t(ssize_t, ret, len);
826 static void tun_setup(struct net_device *dev)
828 struct tun_struct *tun = netdev_priv(dev);
833 dev->ethtool_ops = &tun_ethtool_ops;
834 dev->destructor = tun_free_netdev;
837 /* Trivial set of netlink ops to allow deleting tun or tap
838 * device with netlink.
840 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
845 static struct rtnl_link_ops tun_link_ops __read_mostly = {
847 .priv_size = sizeof(struct tun_struct),
849 .validate = tun_validate,
852 static void tun_sock_write_space(struct sock *sk)
854 struct tun_struct *tun;
856 if (!sock_writeable(sk))
859 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
862 if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
863 wake_up_interruptible_sync_poll(sk->sk_sleep, POLLOUT |
864 POLLWRNORM | POLLWRBAND);
866 tun = tun_sk(sk)->tun;
867 kill_fasync(&tun->fasync, SIGIO, POLL_OUT);
870 static void tun_sock_destruct(struct sock *sk)
872 free_netdev(tun_sk(sk)->tun->dev);
875 static int tun_sendmsg(struct kiocb *iocb, struct socket *sock,
876 struct msghdr *m, size_t total_len)
878 struct tun_struct *tun = container_of(sock, struct tun_struct, socket);
879 return tun_get_user(tun, m->msg_iov, total_len,
880 m->msg_flags & MSG_DONTWAIT);
883 static int tun_recvmsg(struct kiocb *iocb, struct socket *sock,
884 struct msghdr *m, size_t total_len,
887 struct tun_struct *tun = container_of(sock, struct tun_struct, socket);
889 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC))
891 ret = tun_do_read(tun, iocb, m->msg_iov, total_len,
892 flags & MSG_DONTWAIT);
893 if (ret > total_len) {
894 m->msg_flags |= MSG_TRUNC;
895 ret = flags & MSG_TRUNC ? ret : total_len;
900 /* Ops structure to mimic raw sockets with tun */
901 static const struct proto_ops tun_socket_ops = {
902 .sendmsg = tun_sendmsg,
903 .recvmsg = tun_recvmsg,
906 static struct proto tun_proto = {
908 .owner = THIS_MODULE,
909 .obj_size = sizeof(struct tun_sock),
912 static int tun_flags(struct tun_struct *tun)
916 if (tun->flags & TUN_TUN_DEV)
921 if (tun->flags & TUN_NO_PI)
924 if (tun->flags & TUN_ONE_QUEUE)
925 flags |= IFF_ONE_QUEUE;
927 if (tun->flags & TUN_VNET_HDR)
928 flags |= IFF_VNET_HDR;
933 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
936 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
937 return sprintf(buf, "0x%x\n", tun_flags(tun));
940 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
943 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
944 return sprintf(buf, "%d\n", tun->owner);
947 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
950 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
951 return sprintf(buf, "%d\n", tun->group);
954 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
955 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
956 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
958 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
961 struct tun_struct *tun;
962 struct net_device *dev;
965 dev = __dev_get_by_name(net, ifr->ifr_name);
967 const struct cred *cred = current_cred();
969 if (ifr->ifr_flags & IFF_TUN_EXCL)
971 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
972 tun = netdev_priv(dev);
973 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
974 tun = netdev_priv(dev);
978 if (((tun->owner != -1 && cred->euid != tun->owner) ||
979 (tun->group != -1 && !in_egroup_p(tun->group))) &&
980 !capable(CAP_NET_ADMIN))
982 err = security_tun_dev_attach(tun->socket.sk);
986 err = tun_attach(tun, file);
992 unsigned long flags = 0;
994 if (!capable(CAP_NET_ADMIN))
996 err = security_tun_dev_create();
1001 if (ifr->ifr_flags & IFF_TUN) {
1003 flags |= TUN_TUN_DEV;
1005 } else if (ifr->ifr_flags & IFF_TAP) {
1007 flags |= TUN_TAP_DEV;
1013 name = ifr->ifr_name;
1015 dev = alloc_netdev(sizeof(struct tun_struct), name,
1020 dev_net_set(dev, net);
1021 dev->rtnl_link_ops = &tun_link_ops;
1023 tun = netdev_priv(dev);
1026 tun->txflt.count = 0;
1029 sk = sk_alloc(net, AF_UNSPEC, GFP_KERNEL, &tun_proto);
1033 init_waitqueue_head(&tun->socket.wait);
1034 tun->socket.ops = &tun_socket_ops;
1035 sock_init_data(&tun->socket, sk);
1036 sk->sk_write_space = tun_sock_write_space;
1037 sk->sk_sndbuf = INT_MAX;
1039 tun_sk(sk)->tun = tun;
1041 security_tun_dev_post_create(sk);
1045 if (strchr(dev->name, '%')) {
1046 err = dev_alloc_name(dev, dev->name);
1051 err = register_netdevice(tun->dev);
1055 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
1056 device_create_file(&tun->dev->dev, &dev_attr_owner) ||
1057 device_create_file(&tun->dev->dev, &dev_attr_group))
1058 printk(KERN_ERR "Failed to create tun sysfs files\n");
1060 sk->sk_destruct = tun_sock_destruct;
1062 err = tun_attach(tun, file);
1067 DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);
1069 if (ifr->ifr_flags & IFF_NO_PI)
1070 tun->flags |= TUN_NO_PI;
1072 tun->flags &= ~TUN_NO_PI;
1074 if (ifr->ifr_flags & IFF_ONE_QUEUE)
1075 tun->flags |= TUN_ONE_QUEUE;
1077 tun->flags &= ~TUN_ONE_QUEUE;
1079 if (ifr->ifr_flags & IFF_VNET_HDR)
1080 tun->flags |= TUN_VNET_HDR;
1082 tun->flags &= ~TUN_VNET_HDR;
1084 /* Make sure persistent devices do not get stuck in
1087 if (netif_running(tun->dev))
1088 netif_wake_queue(tun->dev);
1090 strcpy(ifr->ifr_name, tun->dev->name);
1101 static int tun_get_iff(struct net *net, struct tun_struct *tun,
1104 DBG(KERN_INFO "%s: tun_get_iff\n", tun->dev->name);
1106 strcpy(ifr->ifr_name, tun->dev->name);
1108 ifr->ifr_flags = tun_flags(tun);
1113 /* This is like a cut-down ethtool ops, except done via tun fd so no
1114 * privs required. */
1115 static int set_offload(struct net_device *dev, unsigned long arg)
1117 unsigned int old_features, features;
1119 old_features = dev->features;
1120 /* Unset features, set them as we chew on the arg. */
1121 features = (old_features & ~(NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST
1122 |NETIF_F_TSO_ECN|NETIF_F_TSO|NETIF_F_TSO6
1125 if (arg & TUN_F_CSUM) {
1126 features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1129 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1130 if (arg & TUN_F_TSO_ECN) {
1131 features |= NETIF_F_TSO_ECN;
1132 arg &= ~TUN_F_TSO_ECN;
1134 if (arg & TUN_F_TSO4)
1135 features |= NETIF_F_TSO;
1136 if (arg & TUN_F_TSO6)
1137 features |= NETIF_F_TSO6;
1138 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1141 if (arg & TUN_F_UFO) {
1142 features |= NETIF_F_UFO;
1147 /* This gives the user a way to test for new features in future by
1148 * trying to set them. */
1152 dev->features = features;
1153 if (old_features != dev->features)
1154 netdev_features_change(dev);
1159 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
1160 unsigned long arg, int ifreq_len)
1162 struct tun_file *tfile = file->private_data;
1163 struct tun_struct *tun;
1164 void __user* argp = (void __user*)arg;
1169 if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
1170 if (copy_from_user(&ifr, argp, ifreq_len))
1173 if (cmd == TUNGETFEATURES) {
1174 /* Currently this just means: "what IFF flags are valid?".
1175 * This is needed because we never checked for invalid flags on
1177 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
1179 (unsigned int __user*)argp);
1184 tun = __tun_get(tfile);
1185 if (cmd == TUNSETIFF && !tun) {
1186 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1188 ret = tun_set_iff(tfile->net, file, &ifr);
1193 if (copy_to_user(argp, &ifr, ifreq_len))
1202 DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd);
1207 ret = tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1211 if (copy_to_user(argp, &ifr, ifreq_len))
1216 /* Disable/Enable checksum */
1218 tun->flags |= TUN_NOCHECKSUM;
1220 tun->flags &= ~TUN_NOCHECKSUM;
1222 DBG(KERN_INFO "%s: checksum %s\n",
1223 tun->dev->name, arg ? "disabled" : "enabled");
1227 /* Disable/Enable persist mode */
1229 tun->flags |= TUN_PERSIST;
1231 tun->flags &= ~TUN_PERSIST;
1233 DBG(KERN_INFO "%s: persist %s\n",
1234 tun->dev->name, arg ? "enabled" : "disabled");
1238 /* Set owner of the device */
1239 tun->owner = (uid_t) arg;
1241 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner);
1245 /* Set group of the device */
1246 tun->group= (gid_t) arg;
1248 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group);
1252 /* Only allow setting the type when the interface is down */
1253 if (tun->dev->flags & IFF_UP) {
1254 DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
1258 tun->dev->type = (int) arg;
1259 DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
1270 ret = set_offload(tun->dev, arg);
1273 case TUNSETTXFILTER:
1274 /* Can be set only for TAPs */
1276 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1278 ret = update_filter(&tun->txflt, (void __user *)arg);
1283 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
1284 ifr.ifr_hwaddr.sa_family = tun->dev->type;
1285 if (copy_to_user(argp, &ifr, ifreq_len))
1290 /* Set hw address */
1291 DBG(KERN_DEBUG "%s: set hw address: %pM\n",
1292 tun->dev->name, ifr.ifr_hwaddr.sa_data);
1294 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
1298 sndbuf = tun->socket.sk->sk_sndbuf;
1299 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
1304 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
1309 tun->socket.sk->sk_sndbuf = sndbuf;
1324 static long tun_chr_ioctl(struct file *file,
1325 unsigned int cmd, unsigned long arg)
1327 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
1330 #ifdef CONFIG_COMPAT
1331 static long tun_chr_compat_ioctl(struct file *file,
1332 unsigned int cmd, unsigned long arg)
1337 case TUNSETTXFILTER:
1342 arg = (unsigned long)compat_ptr(arg);
1345 arg = (compat_ulong_t)arg;
1350 * compat_ifreq is shorter than ifreq, so we must not access beyond
1351 * the end of that structure. All fields that are used in this
1352 * driver are compatible though, we don't need to convert the
1355 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
1357 #endif /* CONFIG_COMPAT */
1359 static int tun_chr_fasync(int fd, struct file *file, int on)
1361 struct tun_struct *tun = tun_get(file);
1367 DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);
1369 if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
1373 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
1376 tun->flags |= TUN_FASYNC;
1378 tun->flags &= ~TUN_FASYNC;
1385 static int tun_chr_open(struct inode *inode, struct file * file)
1387 struct tun_file *tfile;
1389 DBG1(KERN_INFO "tunX: tun_chr_open\n");
1391 tfile = kmalloc(sizeof(*tfile), GFP_KERNEL);
1394 atomic_set(&tfile->count, 0);
1396 tfile->net = get_net(current->nsproxy->net_ns);
1397 file->private_data = tfile;
1401 static int tun_chr_close(struct inode *inode, struct file *file)
1403 struct tun_file *tfile = file->private_data;
1404 struct tun_struct *tun;
1406 tun = __tun_get(tfile);
1408 struct net_device *dev = tun->dev;
1410 DBG(KERN_INFO "%s: tun_chr_close\n", dev->name);
1414 /* If desireable, unregister the netdevice. */
1415 if (!(tun->flags & TUN_PERSIST)) {
1417 if (dev->reg_state == NETREG_REGISTERED)
1418 unregister_netdevice(dev);
1425 sock_put(tun->socket.sk);
1427 put_net(tfile->net);
1433 static const struct file_operations tun_fops = {
1434 .owner = THIS_MODULE,
1435 .llseek = no_llseek,
1436 .read = do_sync_read,
1437 .aio_read = tun_chr_aio_read,
1438 .write = do_sync_write,
1439 .aio_write = tun_chr_aio_write,
1440 .poll = tun_chr_poll,
1441 .unlocked_ioctl = tun_chr_ioctl,
1442 #ifdef CONFIG_COMPAT
1443 .compat_ioctl = tun_chr_compat_ioctl,
1445 .open = tun_chr_open,
1446 .release = tun_chr_close,
1447 .fasync = tun_chr_fasync
1450 static struct miscdevice tun_miscdev = {
1453 .nodename = "net/tun",
1457 /* ethtool interface */
1459 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1462 cmd->advertising = 0;
1463 cmd->speed = SPEED_10;
1464 cmd->duplex = DUPLEX_FULL;
1465 cmd->port = PORT_TP;
1466 cmd->phy_address = 0;
1467 cmd->transceiver = XCVR_INTERNAL;
1468 cmd->autoneg = AUTONEG_DISABLE;
1474 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
1476 struct tun_struct *tun = netdev_priv(dev);
1478 strcpy(info->driver, DRV_NAME);
1479 strcpy(info->version, DRV_VERSION);
1480 strcpy(info->fw_version, "N/A");
1482 switch (tun->flags & TUN_TYPE_MASK) {
1484 strcpy(info->bus_info, "tun");
1487 strcpy(info->bus_info, "tap");
1492 static u32 tun_get_msglevel(struct net_device *dev)
1495 struct tun_struct *tun = netdev_priv(dev);
1502 static void tun_set_msglevel(struct net_device *dev, u32 value)
1505 struct tun_struct *tun = netdev_priv(dev);
1510 static u32 tun_get_link(struct net_device *dev)
1512 struct tun_struct *tun = netdev_priv(dev);
1513 return !!tun->tfile;
1516 static u32 tun_get_rx_csum(struct net_device *dev)
1518 struct tun_struct *tun = netdev_priv(dev);
1519 return (tun->flags & TUN_NOCHECKSUM) == 0;
1522 static int tun_set_rx_csum(struct net_device *dev, u32 data)
1524 struct tun_struct *tun = netdev_priv(dev);
1526 tun->flags &= ~TUN_NOCHECKSUM;
1528 tun->flags |= TUN_NOCHECKSUM;
1532 static const struct ethtool_ops tun_ethtool_ops = {
1533 .get_settings = tun_get_settings,
1534 .get_drvinfo = tun_get_drvinfo,
1535 .get_msglevel = tun_get_msglevel,
1536 .set_msglevel = tun_set_msglevel,
1537 .get_link = tun_get_link,
1538 .get_rx_csum = tun_get_rx_csum,
1539 .set_rx_csum = tun_set_rx_csum
1543 static int __init tun_init(void)
1547 printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
1548 printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);
1550 ret = rtnl_link_register(&tun_link_ops);
1552 printk(KERN_ERR "tun: Can't register link_ops\n");
1556 ret = misc_register(&tun_miscdev);
1558 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
1563 rtnl_link_unregister(&tun_link_ops);
1568 static void tun_cleanup(void)
1570 misc_deregister(&tun_miscdev);
1571 rtnl_link_unregister(&tun_link_ops);
1574 /* Get an underlying socket object from tun file. Returns error unless file is
1575 * attached to a device. The returned object works like a packet socket, it
1576 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
1577 * holding a reference to the file for as long as the socket is in use. */
1578 struct socket *tun_get_socket(struct file *file)
1580 struct tun_struct *tun;
1581 if (file->f_op != &tun_fops)
1582 return ERR_PTR(-EINVAL);
1583 tun = tun_get(file);
1585 return ERR_PTR(-EBADFD);
1587 return &tun->socket;
1589 EXPORT_SYMBOL_GPL(tun_get_socket);
1591 module_init(tun_init);
1592 module_exit(tun_cleanup);
1593 MODULE_DESCRIPTION(DRV_DESCRIPTION);
1594 MODULE_AUTHOR(DRV_COPYRIGHT);
1595 MODULE_LICENSE("GPL");
1596 MODULE_ALIAS_MISCDEV(TUN_MINOR);