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 <linux/rcupdate.h>
65 #include <net/net_namespace.h>
66 #include <net/netns/generic.h>
67 #include <net/rtnetlink.h>
70 #include <asm/system.h>
71 #include <asm/uaccess.h>
73 /* Uncomment to enable debugging */
74 /* #define TUN_DEBUG 1 */
79 #define DBG if(tun->debug)printk
80 #define DBG1 if(debug==2)printk
86 #define FLT_EXACT_COUNT 8
88 unsigned int count; /* Number of addrs. Zero means disabled */
89 u32 mask[2]; /* Mask of the hashed addrs */
90 unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN];
95 struct tun_struct *tun;
102 struct tun_file *tfile;
107 struct net_device *dev;
108 struct fasync_struct *fasync;
110 struct tap_filter txflt;
111 struct socket socket;
123 struct tun_struct *tun;
126 static inline struct tun_sock *tun_sk(struct sock *sk)
128 return container_of(sk, struct tun_sock, sk);
131 static int tun_attach(struct tun_struct *tun, struct file *file)
133 struct tun_file *tfile = file->private_data;
138 netif_tx_lock_bh(tun->dev);
151 tun->socket.file = file;
153 sock_hold(tun->socket.sk);
154 atomic_inc(&tfile->count);
157 netif_tx_unlock_bh(tun->dev);
161 static void __tun_detach(struct tun_struct *tun)
163 /* Detach from net device */
164 netif_tx_lock_bh(tun->dev);
166 tun->socket.file = NULL;
167 netif_tx_unlock_bh(tun->dev);
169 /* Drop read queue */
170 skb_queue_purge(&tun->socket.sk->sk_receive_queue);
172 /* Drop the extra count on the net device */
176 static void tun_detach(struct tun_struct *tun)
183 static struct tun_struct *__tun_get(struct tun_file *tfile)
185 struct tun_struct *tun = NULL;
187 if (atomic_inc_not_zero(&tfile->count))
193 static struct tun_struct *tun_get(struct file *file)
195 return __tun_get(file->private_data);
198 static void tun_put(struct tun_struct *tun)
200 struct tun_file *tfile = tun->tfile;
202 if (atomic_dec_and_test(&tfile->count))
203 tun_detach(tfile->tun);
207 static void addr_hash_set(u32 *mask, const u8 *addr)
209 int n = ether_crc(ETH_ALEN, addr) >> 26;
210 mask[n >> 5] |= (1 << (n & 31));
213 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
215 int n = ether_crc(ETH_ALEN, addr) >> 26;
216 return mask[n >> 5] & (1 << (n & 31));
219 static int update_filter(struct tap_filter *filter, void __user *arg)
221 struct { u8 u[ETH_ALEN]; } *addr;
222 struct tun_filter uf;
223 int err, alen, n, nexact;
225 if (copy_from_user(&uf, arg, sizeof(uf)))
234 alen = ETH_ALEN * uf.count;
235 addr = kmalloc(alen, GFP_KERNEL);
239 if (copy_from_user(addr, arg + sizeof(uf), alen)) {
244 /* The filter is updated without holding any locks. Which is
245 * perfectly safe. We disable it first and in the worst
246 * case we'll accept a few undesired packets. */
250 /* Use first set of addresses as an exact filter */
251 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
252 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
256 /* Remaining multicast addresses are hashed,
257 * unicast will leave the filter disabled. */
258 memset(filter->mask, 0, sizeof(filter->mask));
259 for (; n < uf.count; n++) {
260 if (!is_multicast_ether_addr(addr[n].u)) {
261 err = 0; /* no filter */
264 addr_hash_set(filter->mask, addr[n].u);
267 /* For ALLMULTI just set the mask to all ones.
268 * This overrides the mask populated above. */
269 if ((uf.flags & TUN_FLT_ALLMULTI))
270 memset(filter->mask, ~0, sizeof(filter->mask));
272 /* Now enable the filter */
274 filter->count = nexact;
276 /* Return the number of exact filters */
284 /* Returns: 0 - drop, !=0 - accept */
285 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
287 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
289 struct ethhdr *eh = (struct ethhdr *) skb->data;
293 for (i = 0; i < filter->count; i++)
294 if (!compare_ether_addr(eh->h_dest, filter->addr[i]))
297 /* Inexact match (multicast only) */
298 if (is_multicast_ether_addr(eh->h_dest))
299 return addr_hash_test(filter->mask, eh->h_dest);
305 * Checks whether the packet is accepted or not.
306 * Returns: 0 - drop, !=0 - accept
308 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
313 return run_filter(filter, skb);
316 /* Network device part of the driver */
318 static const struct ethtool_ops tun_ethtool_ops;
320 /* Net device detach from fd. */
321 static void tun_net_uninit(struct net_device *dev)
323 struct tun_struct *tun = netdev_priv(dev);
324 struct tun_file *tfile = tun->tfile;
326 /* Inform the methods they need to stop using the dev.
329 wake_up_all(&tun->wq.wait);
330 if (atomic_dec_and_test(&tfile->count))
335 static void tun_free_netdev(struct net_device *dev)
337 struct tun_struct *tun = netdev_priv(dev);
339 sock_put(tun->socket.sk);
342 /* Net device open. */
343 static int tun_net_open(struct net_device *dev)
345 netif_start_queue(dev);
349 /* Net device close. */
350 static int tun_net_close(struct net_device *dev)
352 netif_stop_queue(dev);
356 /* Net device start xmit */
357 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
359 struct tun_struct *tun = netdev_priv(dev);
361 DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len);
363 /* Drop packet if interface is not attached */
367 /* Drop if the filter does not like it.
368 * This is a noop if the filter is disabled.
369 * Filter can be enabled only for the TAP devices. */
370 if (!check_filter(&tun->txflt, skb))
373 if (tun->socket.sk->sk_filter &&
374 sk_filter(tun->socket.sk, skb))
377 if (skb_queue_len(&tun->socket.sk->sk_receive_queue) >= dev->tx_queue_len) {
378 if (!(tun->flags & TUN_ONE_QUEUE)) {
379 /* Normal queueing mode. */
380 /* Packet scheduler handles dropping of further packets. */
381 netif_stop_queue(dev);
383 /* We won't see all dropped packets individually, so overrun
384 * error is more appropriate. */
385 dev->stats.tx_fifo_errors++;
387 /* Single queue mode.
388 * Driver handles dropping of all packets itself. */
393 /* Orphan the skb - required as we might hang on to it
394 * for indefinite time. */
398 skb_queue_tail(&tun->socket.sk->sk_receive_queue, skb);
400 /* Notify and wake up reader process */
401 if (tun->flags & TUN_FASYNC)
402 kill_fasync(&tun->fasync, SIGIO, POLL_IN);
403 wake_up_interruptible_poll(&tun->wq.wait, POLLIN |
404 POLLRDNORM | POLLRDBAND);
408 dev->stats.tx_dropped++;
413 static void tun_net_mclist(struct net_device *dev)
416 * This callback is supposed to deal with mc filter in
417 * _rx_ path and has nothing to do with the _tx_ path.
418 * In rx path we always accept everything userspace gives us.
423 #define MAX_MTU 65535
426 tun_net_change_mtu(struct net_device *dev, int new_mtu)
428 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
434 static const struct net_device_ops tun_netdev_ops = {
435 .ndo_uninit = tun_net_uninit,
436 .ndo_open = tun_net_open,
437 .ndo_stop = tun_net_close,
438 .ndo_start_xmit = tun_net_xmit,
439 .ndo_change_mtu = tun_net_change_mtu,
442 static const struct net_device_ops tap_netdev_ops = {
443 .ndo_uninit = tun_net_uninit,
444 .ndo_open = tun_net_open,
445 .ndo_stop = tun_net_close,
446 .ndo_start_xmit = tun_net_xmit,
447 .ndo_change_mtu = tun_net_change_mtu,
448 .ndo_set_multicast_list = tun_net_mclist,
449 .ndo_set_mac_address = eth_mac_addr,
450 .ndo_validate_addr = eth_validate_addr,
453 /* Initialize net device. */
454 static void tun_net_init(struct net_device *dev)
456 struct tun_struct *tun = netdev_priv(dev);
458 switch (tun->flags & TUN_TYPE_MASK) {
460 dev->netdev_ops = &tun_netdev_ops;
462 /* Point-to-Point TUN Device */
463 dev->hard_header_len = 0;
467 /* Zero header length */
468 dev->type = ARPHRD_NONE;
469 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
470 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
474 dev->netdev_ops = &tap_netdev_ops;
475 /* Ethernet TAP Device */
478 random_ether_addr(dev->dev_addr);
480 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
485 /* Character device part */
488 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
490 struct tun_file *tfile = file->private_data;
491 struct tun_struct *tun = __tun_get(tfile);
493 unsigned int mask = 0;
500 DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name);
502 poll_wait(file, &tun->wq.wait, wait);
504 if (!skb_queue_empty(&sk->sk_receive_queue))
505 mask |= POLLIN | POLLRDNORM;
507 if (sock_writeable(sk) ||
508 (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
510 mask |= POLLOUT | POLLWRNORM;
512 if (tun->dev->reg_state != NETREG_REGISTERED)
519 /* prepad is the amount to reserve at front. len is length after that.
520 * linear is a hint as to how much to copy (usually headers). */
521 static inline struct sk_buff *tun_alloc_skb(struct tun_struct *tun,
522 size_t prepad, size_t len,
523 size_t linear, int noblock)
525 struct sock *sk = tun->socket.sk;
529 /* Under a page? Don't bother with paged skb. */
530 if (prepad + len < PAGE_SIZE || !linear)
533 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
538 skb_reserve(skb, prepad);
539 skb_put(skb, linear);
540 skb->data_len = len - linear;
541 skb->len += len - linear;
546 /* Get packet from user space buffer */
547 static __inline__ ssize_t tun_get_user(struct tun_struct *tun,
548 const struct iovec *iv, size_t count,
551 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
553 size_t len = count, align = 0;
554 struct virtio_net_hdr gso = { 0 };
557 if (!(tun->flags & TUN_NO_PI)) {
558 if ((len -= sizeof(pi)) > count)
561 if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
563 offset += sizeof(pi);
566 if (tun->flags & TUN_VNET_HDR) {
567 if ((len -= tun->vnet_hdr_sz) > count)
570 if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
573 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
574 gso.csum_start + gso.csum_offset + 2 > gso.hdr_len)
575 gso.hdr_len = gso.csum_start + gso.csum_offset + 2;
577 if (gso.hdr_len > len)
579 offset += tun->vnet_hdr_sz;
582 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
583 align = NET_IP_ALIGN;
584 if (unlikely(len < ETH_HLEN ||
585 (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
589 skb = tun_alloc_skb(tun, align, len, gso.hdr_len, noblock);
591 if (PTR_ERR(skb) != -EAGAIN)
592 tun->dev->stats.rx_dropped++;
596 if (skb_copy_datagram_from_iovec(skb, 0, iv, offset, len)) {
597 tun->dev->stats.rx_dropped++;
602 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
603 if (!skb_partial_csum_set(skb, gso.csum_start,
605 tun->dev->stats.rx_frame_errors++;
609 } else if (tun->flags & TUN_NOCHECKSUM)
610 skb->ip_summed = CHECKSUM_UNNECESSARY;
612 switch (tun->flags & TUN_TYPE_MASK) {
614 if (tun->flags & TUN_NO_PI) {
615 switch (skb->data[0] & 0xf0) {
617 pi.proto = htons(ETH_P_IP);
620 pi.proto = htons(ETH_P_IPV6);
623 tun->dev->stats.rx_dropped++;
629 skb_reset_mac_header(skb);
630 skb->protocol = pi.proto;
634 skb->protocol = eth_type_trans(skb, tun->dev);
638 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
640 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
641 case VIRTIO_NET_HDR_GSO_TCPV4:
642 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
644 case VIRTIO_NET_HDR_GSO_TCPV6:
645 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
647 case VIRTIO_NET_HDR_GSO_UDP:
648 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
651 tun->dev->stats.rx_frame_errors++;
656 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
657 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
659 skb_shinfo(skb)->gso_size = gso.gso_size;
660 if (skb_shinfo(skb)->gso_size == 0) {
661 tun->dev->stats.rx_frame_errors++;
666 /* Header must be checked, and gso_segs computed. */
667 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
668 skb_shinfo(skb)->gso_segs = 0;
673 tun->dev->stats.rx_packets++;
674 tun->dev->stats.rx_bytes += len;
679 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
680 unsigned long count, loff_t pos)
682 struct file *file = iocb->ki_filp;
683 struct tun_struct *tun = tun_get(file);
689 DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);
691 result = tun_get_user(tun, iv, iov_length(iv, count),
692 file->f_flags & O_NONBLOCK);
698 /* Put packet to the user space buffer */
699 static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
701 const struct iovec *iv, int len)
703 struct tun_pi pi = { 0, skb->protocol };
706 if (!(tun->flags & TUN_NO_PI)) {
707 if ((len -= sizeof(pi)) < 0)
710 if (len < skb->len) {
711 /* Packet will be striped */
712 pi.flags |= TUN_PKT_STRIP;
715 if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi)))
720 if (tun->flags & TUN_VNET_HDR) {
721 struct virtio_net_hdr gso = { 0 }; /* no info leak */
722 if ((len -= tun->vnet_hdr_sz) < 0)
725 if (skb_is_gso(skb)) {
726 struct skb_shared_info *sinfo = skb_shinfo(skb);
728 /* This is a hint as to how much should be linear. */
729 gso.hdr_len = skb_headlen(skb);
730 gso.gso_size = sinfo->gso_size;
731 if (sinfo->gso_type & SKB_GSO_TCPV4)
732 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
733 else if (sinfo->gso_type & SKB_GSO_TCPV6)
734 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
735 else if (sinfo->gso_type & SKB_GSO_UDP)
736 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
739 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
740 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
742 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
744 if (skb->ip_summed == CHECKSUM_PARTIAL) {
745 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
746 gso.csum_start = skb->csum_start - skb_headroom(skb);
747 gso.csum_offset = skb->csum_offset;
748 } /* else everything is zero */
750 if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
753 total += tun->vnet_hdr_sz;
756 len = min_t(int, skb->len, len);
758 skb_copy_datagram_const_iovec(skb, 0, iv, total, len);
761 tun->dev->stats.tx_packets++;
762 tun->dev->stats.tx_bytes += len;
767 static ssize_t tun_do_read(struct tun_struct *tun,
768 struct kiocb *iocb, const struct iovec *iv,
769 ssize_t len, int noblock)
771 DECLARE_WAITQUEUE(wait, current);
775 DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
777 add_wait_queue(&tun->wq.wait, &wait);
779 current->state = TASK_INTERRUPTIBLE;
781 /* Read frames from the queue */
782 if (!(skb=skb_dequeue(&tun->socket.sk->sk_receive_queue))) {
787 if (signal_pending(current)) {
791 if (tun->dev->reg_state != NETREG_REGISTERED) {
796 /* Nothing to read, let's sleep */
800 netif_wake_queue(tun->dev);
802 ret = tun_put_user(tun, skb, iv, len);
807 current->state = TASK_RUNNING;
808 remove_wait_queue(&tun->wq.wait, &wait);
813 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
814 unsigned long count, loff_t pos)
816 struct file *file = iocb->ki_filp;
817 struct tun_file *tfile = file->private_data;
818 struct tun_struct *tun = __tun_get(tfile);
823 len = iov_length(iv, count);
829 ret = tun_do_read(tun, iocb, iv, len, file->f_flags & O_NONBLOCK);
830 ret = min_t(ssize_t, ret, len);
836 static void tun_setup(struct net_device *dev)
838 struct tun_struct *tun = netdev_priv(dev);
843 dev->ethtool_ops = &tun_ethtool_ops;
844 dev->destructor = tun_free_netdev;
847 /* Trivial set of netlink ops to allow deleting tun or tap
848 * device with netlink.
850 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
855 static struct rtnl_link_ops tun_link_ops __read_mostly = {
857 .priv_size = sizeof(struct tun_struct),
859 .validate = tun_validate,
862 static void tun_sock_write_space(struct sock *sk)
864 struct tun_struct *tun;
865 wait_queue_head_t *wqueue;
867 if (!sock_writeable(sk))
870 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
873 wqueue = sk_sleep(sk);
874 if (wqueue && waitqueue_active(wqueue))
875 wake_up_interruptible_sync_poll(wqueue, POLLOUT |
876 POLLWRNORM | POLLWRBAND);
878 tun = tun_sk(sk)->tun;
879 kill_fasync(&tun->fasync, SIGIO, POLL_OUT);
882 static void tun_sock_destruct(struct sock *sk)
884 free_netdev(tun_sk(sk)->tun->dev);
887 static int tun_sendmsg(struct kiocb *iocb, struct socket *sock,
888 struct msghdr *m, size_t total_len)
890 struct tun_struct *tun = container_of(sock, struct tun_struct, socket);
891 return tun_get_user(tun, m->msg_iov, total_len,
892 m->msg_flags & MSG_DONTWAIT);
895 static int tun_recvmsg(struct kiocb *iocb, struct socket *sock,
896 struct msghdr *m, size_t total_len,
899 struct tun_struct *tun = container_of(sock, struct tun_struct, socket);
901 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC))
903 ret = tun_do_read(tun, iocb, m->msg_iov, total_len,
904 flags & MSG_DONTWAIT);
905 if (ret > total_len) {
906 m->msg_flags |= MSG_TRUNC;
907 ret = flags & MSG_TRUNC ? ret : total_len;
912 /* Ops structure to mimic raw sockets with tun */
913 static const struct proto_ops tun_socket_ops = {
914 .sendmsg = tun_sendmsg,
915 .recvmsg = tun_recvmsg,
918 static struct proto tun_proto = {
920 .owner = THIS_MODULE,
921 .obj_size = sizeof(struct tun_sock),
924 static int tun_flags(struct tun_struct *tun)
928 if (tun->flags & TUN_TUN_DEV)
933 if (tun->flags & TUN_NO_PI)
936 if (tun->flags & TUN_ONE_QUEUE)
937 flags |= IFF_ONE_QUEUE;
939 if (tun->flags & TUN_VNET_HDR)
940 flags |= IFF_VNET_HDR;
945 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
948 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
949 return sprintf(buf, "0x%x\n", tun_flags(tun));
952 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
955 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
956 return sprintf(buf, "%d\n", tun->owner);
959 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
962 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
963 return sprintf(buf, "%d\n", tun->group);
966 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
967 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
968 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
970 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
973 struct tun_struct *tun;
974 struct net_device *dev;
977 dev = __dev_get_by_name(net, ifr->ifr_name);
979 const struct cred *cred = current_cred();
981 if (ifr->ifr_flags & IFF_TUN_EXCL)
983 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
984 tun = netdev_priv(dev);
985 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
986 tun = netdev_priv(dev);
990 if (((tun->owner != -1 && cred->euid != tun->owner) ||
991 (tun->group != -1 && !in_egroup_p(tun->group))) &&
992 !capable(CAP_NET_ADMIN))
994 err = security_tun_dev_attach(tun->socket.sk);
998 err = tun_attach(tun, file);
1004 unsigned long flags = 0;
1006 if (!capable(CAP_NET_ADMIN))
1008 err = security_tun_dev_create();
1013 if (ifr->ifr_flags & IFF_TUN) {
1015 flags |= TUN_TUN_DEV;
1017 } else if (ifr->ifr_flags & IFF_TAP) {
1019 flags |= TUN_TAP_DEV;
1025 name = ifr->ifr_name;
1027 dev = alloc_netdev(sizeof(struct tun_struct), name,
1032 dev_net_set(dev, net);
1033 dev->rtnl_link_ops = &tun_link_ops;
1035 tun = netdev_priv(dev);
1038 tun->txflt.count = 0;
1039 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
1042 sk = sk_alloc(net, AF_UNSPEC, GFP_KERNEL, &tun_proto);
1046 tun->socket.wq = &tun->wq;
1047 init_waitqueue_head(&tun->wq.wait);
1048 tun->socket.ops = &tun_socket_ops;
1049 sock_init_data(&tun->socket, sk);
1050 sk->sk_write_space = tun_sock_write_space;
1051 sk->sk_sndbuf = INT_MAX;
1053 tun_sk(sk)->tun = tun;
1055 security_tun_dev_post_create(sk);
1059 if (strchr(dev->name, '%')) {
1060 err = dev_alloc_name(dev, dev->name);
1065 err = register_netdevice(tun->dev);
1069 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
1070 device_create_file(&tun->dev->dev, &dev_attr_owner) ||
1071 device_create_file(&tun->dev->dev, &dev_attr_group))
1072 printk(KERN_ERR "Failed to create tun sysfs files\n");
1074 sk->sk_destruct = tun_sock_destruct;
1076 err = tun_attach(tun, file);
1081 DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);
1083 if (ifr->ifr_flags & IFF_NO_PI)
1084 tun->flags |= TUN_NO_PI;
1086 tun->flags &= ~TUN_NO_PI;
1088 if (ifr->ifr_flags & IFF_ONE_QUEUE)
1089 tun->flags |= TUN_ONE_QUEUE;
1091 tun->flags &= ~TUN_ONE_QUEUE;
1093 if (ifr->ifr_flags & IFF_VNET_HDR)
1094 tun->flags |= TUN_VNET_HDR;
1096 tun->flags &= ~TUN_VNET_HDR;
1098 /* Make sure persistent devices do not get stuck in
1101 if (netif_running(tun->dev))
1102 netif_wake_queue(tun->dev);
1104 strcpy(ifr->ifr_name, tun->dev->name);
1115 static int tun_get_iff(struct net *net, struct tun_struct *tun,
1118 DBG(KERN_INFO "%s: tun_get_iff\n", tun->dev->name);
1120 strcpy(ifr->ifr_name, tun->dev->name);
1122 ifr->ifr_flags = tun_flags(tun);
1127 /* This is like a cut-down ethtool ops, except done via tun fd so no
1128 * privs required. */
1129 static int set_offload(struct net_device *dev, unsigned long arg)
1131 unsigned int old_features, features;
1133 old_features = dev->features;
1134 /* Unset features, set them as we chew on the arg. */
1135 features = (old_features & ~(NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST
1136 |NETIF_F_TSO_ECN|NETIF_F_TSO|NETIF_F_TSO6
1139 if (arg & TUN_F_CSUM) {
1140 features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1143 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1144 if (arg & TUN_F_TSO_ECN) {
1145 features |= NETIF_F_TSO_ECN;
1146 arg &= ~TUN_F_TSO_ECN;
1148 if (arg & TUN_F_TSO4)
1149 features |= NETIF_F_TSO;
1150 if (arg & TUN_F_TSO6)
1151 features |= NETIF_F_TSO6;
1152 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1155 if (arg & TUN_F_UFO) {
1156 features |= NETIF_F_UFO;
1161 /* This gives the user a way to test for new features in future by
1162 * trying to set them. */
1166 dev->features = features;
1167 if (old_features != dev->features)
1168 netdev_features_change(dev);
1173 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
1174 unsigned long arg, int ifreq_len)
1176 struct tun_file *tfile = file->private_data;
1177 struct tun_struct *tun;
1178 void __user* argp = (void __user*)arg;
1179 struct sock_fprog fprog;
1185 if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
1186 if (copy_from_user(&ifr, argp, ifreq_len))
1189 if (cmd == TUNGETFEATURES) {
1190 /* Currently this just means: "what IFF flags are valid?".
1191 * This is needed because we never checked for invalid flags on
1193 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
1195 (unsigned int __user*)argp);
1200 tun = __tun_get(tfile);
1201 if (cmd == TUNSETIFF && !tun) {
1202 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1204 ret = tun_set_iff(tfile->net, file, &ifr);
1209 if (copy_to_user(argp, &ifr, ifreq_len))
1218 DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd);
1223 ret = tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1227 if (copy_to_user(argp, &ifr, ifreq_len))
1232 /* Disable/Enable checksum */
1234 tun->flags |= TUN_NOCHECKSUM;
1236 tun->flags &= ~TUN_NOCHECKSUM;
1238 DBG(KERN_INFO "%s: checksum %s\n",
1239 tun->dev->name, arg ? "disabled" : "enabled");
1243 /* Disable/Enable persist mode */
1245 tun->flags |= TUN_PERSIST;
1247 tun->flags &= ~TUN_PERSIST;
1249 DBG(KERN_INFO "%s: persist %s\n",
1250 tun->dev->name, arg ? "enabled" : "disabled");
1254 /* Set owner of the device */
1255 tun->owner = (uid_t) arg;
1257 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner);
1261 /* Set group of the device */
1262 tun->group= (gid_t) arg;
1264 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group);
1268 /* Only allow setting the type when the interface is down */
1269 if (tun->dev->flags & IFF_UP) {
1270 DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
1274 tun->dev->type = (int) arg;
1275 DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
1286 ret = set_offload(tun->dev, arg);
1289 case TUNSETTXFILTER:
1290 /* Can be set only for TAPs */
1292 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1294 ret = update_filter(&tun->txflt, (void __user *)arg);
1299 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
1300 ifr.ifr_hwaddr.sa_family = tun->dev->type;
1301 if (copy_to_user(argp, &ifr, ifreq_len))
1306 /* Set hw address */
1307 DBG(KERN_DEBUG "%s: set hw address: %pM\n",
1308 tun->dev->name, ifr.ifr_hwaddr.sa_data);
1310 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
1314 sndbuf = tun->socket.sk->sk_sndbuf;
1315 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
1320 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
1325 tun->socket.sk->sk_sndbuf = sndbuf;
1328 case TUNGETVNETHDRSZ:
1329 vnet_hdr_sz = tun->vnet_hdr_sz;
1330 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
1334 case TUNSETVNETHDRSZ:
1335 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
1339 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
1344 tun->vnet_hdr_sz = vnet_hdr_sz;
1347 case TUNATTACHFILTER:
1348 /* Can be set only for TAPs */
1350 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1353 if (copy_from_user(&fprog, argp, sizeof(fprog)))
1356 ret = sk_attach_filter(&fprog, tun->socket.sk);
1359 case TUNDETACHFILTER:
1360 /* Can be set only for TAPs */
1362 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1364 ret = sk_detach_filter(tun->socket.sk);
1379 static long tun_chr_ioctl(struct file *file,
1380 unsigned int cmd, unsigned long arg)
1382 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
1385 #ifdef CONFIG_COMPAT
1386 static long tun_chr_compat_ioctl(struct file *file,
1387 unsigned int cmd, unsigned long arg)
1392 case TUNSETTXFILTER:
1397 arg = (unsigned long)compat_ptr(arg);
1400 arg = (compat_ulong_t)arg;
1405 * compat_ifreq is shorter than ifreq, so we must not access beyond
1406 * the end of that structure. All fields that are used in this
1407 * driver are compatible though, we don't need to convert the
1410 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
1412 #endif /* CONFIG_COMPAT */
1414 static int tun_chr_fasync(int fd, struct file *file, int on)
1416 struct tun_struct *tun = tun_get(file);
1422 DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);
1424 if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
1428 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
1431 tun->flags |= TUN_FASYNC;
1433 tun->flags &= ~TUN_FASYNC;
1440 static int tun_chr_open(struct inode *inode, struct file * file)
1442 struct tun_file *tfile;
1444 DBG1(KERN_INFO "tunX: tun_chr_open\n");
1446 tfile = kmalloc(sizeof(*tfile), GFP_KERNEL);
1449 atomic_set(&tfile->count, 0);
1451 tfile->net = get_net(current->nsproxy->net_ns);
1452 file->private_data = tfile;
1456 static int tun_chr_close(struct inode *inode, struct file *file)
1458 struct tun_file *tfile = file->private_data;
1459 struct tun_struct *tun;
1461 tun = __tun_get(tfile);
1463 struct net_device *dev = tun->dev;
1465 DBG(KERN_INFO "%s: tun_chr_close\n", dev->name);
1469 /* If desirable, unregister the netdevice. */
1470 if (!(tun->flags & TUN_PERSIST)) {
1472 if (dev->reg_state == NETREG_REGISTERED)
1473 unregister_netdevice(dev);
1480 sock_put(tun->socket.sk);
1482 put_net(tfile->net);
1488 static const struct file_operations tun_fops = {
1489 .owner = THIS_MODULE,
1490 .llseek = no_llseek,
1491 .read = do_sync_read,
1492 .aio_read = tun_chr_aio_read,
1493 .write = do_sync_write,
1494 .aio_write = tun_chr_aio_write,
1495 .poll = tun_chr_poll,
1496 .unlocked_ioctl = tun_chr_ioctl,
1497 #ifdef CONFIG_COMPAT
1498 .compat_ioctl = tun_chr_compat_ioctl,
1500 .open = tun_chr_open,
1501 .release = tun_chr_close,
1502 .fasync = tun_chr_fasync
1505 static struct miscdevice tun_miscdev = {
1508 .nodename = "net/tun",
1512 /* ethtool interface */
1514 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1517 cmd->advertising = 0;
1518 cmd->speed = SPEED_10;
1519 cmd->duplex = DUPLEX_FULL;
1520 cmd->port = PORT_TP;
1521 cmd->phy_address = 0;
1522 cmd->transceiver = XCVR_INTERNAL;
1523 cmd->autoneg = AUTONEG_DISABLE;
1529 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
1531 struct tun_struct *tun = netdev_priv(dev);
1533 strcpy(info->driver, DRV_NAME);
1534 strcpy(info->version, DRV_VERSION);
1535 strcpy(info->fw_version, "N/A");
1537 switch (tun->flags & TUN_TYPE_MASK) {
1539 strcpy(info->bus_info, "tun");
1542 strcpy(info->bus_info, "tap");
1547 static u32 tun_get_msglevel(struct net_device *dev)
1550 struct tun_struct *tun = netdev_priv(dev);
1557 static void tun_set_msglevel(struct net_device *dev, u32 value)
1560 struct tun_struct *tun = netdev_priv(dev);
1565 static u32 tun_get_link(struct net_device *dev)
1567 struct tun_struct *tun = netdev_priv(dev);
1568 return !!tun->tfile;
1571 static u32 tun_get_rx_csum(struct net_device *dev)
1573 struct tun_struct *tun = netdev_priv(dev);
1574 return (tun->flags & TUN_NOCHECKSUM) == 0;
1577 static int tun_set_rx_csum(struct net_device *dev, u32 data)
1579 struct tun_struct *tun = netdev_priv(dev);
1581 tun->flags &= ~TUN_NOCHECKSUM;
1583 tun->flags |= TUN_NOCHECKSUM;
1587 static const struct ethtool_ops tun_ethtool_ops = {
1588 .get_settings = tun_get_settings,
1589 .get_drvinfo = tun_get_drvinfo,
1590 .get_msglevel = tun_get_msglevel,
1591 .set_msglevel = tun_set_msglevel,
1592 .get_link = tun_get_link,
1593 .get_rx_csum = tun_get_rx_csum,
1594 .set_rx_csum = tun_set_rx_csum
1598 static int __init tun_init(void)
1602 printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
1603 printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);
1605 ret = rtnl_link_register(&tun_link_ops);
1607 printk(KERN_ERR "tun: Can't register link_ops\n");
1611 ret = misc_register(&tun_miscdev);
1613 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
1618 rtnl_link_unregister(&tun_link_ops);
1623 static void tun_cleanup(void)
1625 misc_deregister(&tun_miscdev);
1626 rtnl_link_unregister(&tun_link_ops);
1629 /* Get an underlying socket object from tun file. Returns error unless file is
1630 * attached to a device. The returned object works like a packet socket, it
1631 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
1632 * holding a reference to the file for as long as the socket is in use. */
1633 struct socket *tun_get_socket(struct file *file)
1635 struct tun_struct *tun;
1636 if (file->f_op != &tun_fops)
1637 return ERR_PTR(-EINVAL);
1638 tun = tun_get(file);
1640 return ERR_PTR(-EBADFD);
1642 return &tun->socket;
1644 EXPORT_SYMBOL_GPL(tun_get_socket);
1646 module_init(tun_init);
1647 module_exit(tun_cleanup);
1648 MODULE_DESCRIPTION(DRV_DESCRIPTION);
1649 MODULE_AUTHOR(DRV_COPYRIGHT);
1650 MODULE_LICENSE("GPL");
1651 MODULE_ALIAS_MISCDEV(TUN_MINOR);
1652 MODULE_ALIAS("devname:net/tun");