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 pr_fmt(fmt) KBUILD_MODNAME ": " fmt
39 #define DRV_NAME "tun"
40 #define DRV_VERSION "1.6"
41 #define DRV_DESCRIPTION "Universal TUN/TAP device driver"
42 #define DRV_COPYRIGHT "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>"
44 #include <linux/module.h>
45 #include <linux/errno.h>
46 #include <linux/kernel.h>
47 #include <linux/major.h>
48 #include <linux/slab.h>
49 #include <linux/poll.h>
50 #include <linux/fcntl.h>
51 #include <linux/init.h>
52 #include <linux/skbuff.h>
53 #include <linux/netdevice.h>
54 #include <linux/etherdevice.h>
55 #include <linux/miscdevice.h>
56 #include <linux/ethtool.h>
57 #include <linux/rtnetlink.h>
58 #include <linux/compat.h>
60 #include <linux/if_arp.h>
61 #include <linux/if_ether.h>
62 #include <linux/if_tun.h>
63 #include <linux/crc32.h>
64 #include <linux/nsproxy.h>
65 #include <linux/virtio_net.h>
66 #include <linux/rcupdate.h>
68 #include <net/net_namespace.h>
69 #include <net/netns/generic.h>
70 #include <net/rtnetlink.h>
73 #include <asm/system.h>
74 #include <asm/uaccess.h>
76 /* Uncomment to enable debugging */
77 /* #define TUN_DEBUG 1 */
82 #define tun_debug(level, tun, fmt, args...) \
85 netdev_printk(level, tun->dev, fmt, ##args); \
87 #define DBG1(level, fmt, args...) \
90 printk(level fmt, ##args); \
93 #define tun_debug(level, tun, fmt, args...) \
96 netdev_printk(level, tun->dev, fmt, ##args); \
98 #define DBG1(level, fmt, args...) \
101 printk(level fmt, ##args); \
105 #define FLT_EXACT_COUNT 8
107 unsigned int count; /* Number of addrs. Zero means disabled */
108 u32 mask[2]; /* Mask of the hashed addrs */
109 unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN];
114 struct tun_struct *tun;
121 struct tun_file *tfile;
126 struct net_device *dev;
128 #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \
129 NETIF_F_TSO6|NETIF_F_UFO)
130 struct fasync_struct *fasync;
132 struct tap_filter txflt;
133 struct socket socket;
145 struct tun_struct *tun;
148 static inline struct tun_sock *tun_sk(struct sock *sk)
150 return container_of(sk, struct tun_sock, sk);
153 static int tun_attach(struct tun_struct *tun, struct file *file)
155 struct tun_file *tfile = file->private_data;
160 netif_tx_lock_bh(tun->dev);
173 tun->socket.file = file;
174 netif_carrier_on(tun->dev);
176 sock_hold(tun->socket.sk);
177 atomic_inc(&tfile->count);
180 netif_tx_unlock_bh(tun->dev);
184 static void __tun_detach(struct tun_struct *tun)
186 /* Detach from net device */
187 netif_tx_lock_bh(tun->dev);
188 netif_carrier_off(tun->dev);
190 tun->socket.file = NULL;
191 netif_tx_unlock_bh(tun->dev);
193 /* Drop read queue */
194 skb_queue_purge(&tun->socket.sk->sk_receive_queue);
196 /* Drop the extra count on the net device */
200 static void tun_detach(struct tun_struct *tun)
207 static struct tun_struct *__tun_get(struct tun_file *tfile)
209 struct tun_struct *tun = NULL;
211 if (atomic_inc_not_zero(&tfile->count))
217 static struct tun_struct *tun_get(struct file *file)
219 return __tun_get(file->private_data);
222 static void tun_put(struct tun_struct *tun)
224 struct tun_file *tfile = tun->tfile;
226 if (atomic_dec_and_test(&tfile->count))
227 tun_detach(tfile->tun);
231 static void addr_hash_set(u32 *mask, const u8 *addr)
233 int n = ether_crc(ETH_ALEN, addr) >> 26;
234 mask[n >> 5] |= (1 << (n & 31));
237 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
239 int n = ether_crc(ETH_ALEN, addr) >> 26;
240 return mask[n >> 5] & (1 << (n & 31));
243 static int update_filter(struct tap_filter *filter, void __user *arg)
245 struct { u8 u[ETH_ALEN]; } *addr;
246 struct tun_filter uf;
247 int err, alen, n, nexact;
249 if (copy_from_user(&uf, arg, sizeof(uf)))
258 alen = ETH_ALEN * uf.count;
259 addr = kmalloc(alen, GFP_KERNEL);
263 if (copy_from_user(addr, arg + sizeof(uf), alen)) {
268 /* The filter is updated without holding any locks. Which is
269 * perfectly safe. We disable it first and in the worst
270 * case we'll accept a few undesired packets. */
274 /* Use first set of addresses as an exact filter */
275 for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
276 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
280 /* Remaining multicast addresses are hashed,
281 * unicast will leave the filter disabled. */
282 memset(filter->mask, 0, sizeof(filter->mask));
283 for (; n < uf.count; n++) {
284 if (!is_multicast_ether_addr(addr[n].u)) {
285 err = 0; /* no filter */
288 addr_hash_set(filter->mask, addr[n].u);
291 /* For ALLMULTI just set the mask to all ones.
292 * This overrides the mask populated above. */
293 if ((uf.flags & TUN_FLT_ALLMULTI))
294 memset(filter->mask, ~0, sizeof(filter->mask));
296 /* Now enable the filter */
298 filter->count = nexact;
300 /* Return the number of exact filters */
308 /* Returns: 0 - drop, !=0 - accept */
309 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
311 /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
313 struct ethhdr *eh = (struct ethhdr *) skb->data;
317 for (i = 0; i < filter->count; i++)
318 if (!compare_ether_addr(eh->h_dest, filter->addr[i]))
321 /* Inexact match (multicast only) */
322 if (is_multicast_ether_addr(eh->h_dest))
323 return addr_hash_test(filter->mask, eh->h_dest);
329 * Checks whether the packet is accepted or not.
330 * Returns: 0 - drop, !=0 - accept
332 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
337 return run_filter(filter, skb);
340 /* Network device part of the driver */
342 static const struct ethtool_ops tun_ethtool_ops;
344 /* Net device detach from fd. */
345 static void tun_net_uninit(struct net_device *dev)
347 struct tun_struct *tun = netdev_priv(dev);
348 struct tun_file *tfile = tun->tfile;
350 /* Inform the methods they need to stop using the dev.
353 wake_up_all(&tun->wq.wait);
354 if (atomic_dec_and_test(&tfile->count))
359 static void tun_free_netdev(struct net_device *dev)
361 struct tun_struct *tun = netdev_priv(dev);
363 sock_put(tun->socket.sk);
366 /* Net device open. */
367 static int tun_net_open(struct net_device *dev)
369 netif_start_queue(dev);
373 /* Net device close. */
374 static int tun_net_close(struct net_device *dev)
376 netif_stop_queue(dev);
380 /* Net device start xmit */
381 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
383 struct tun_struct *tun = netdev_priv(dev);
385 tun_debug(KERN_INFO, tun, "tun_net_xmit %d\n", skb->len);
387 /* Drop packet if interface is not attached */
391 /* Drop if the filter does not like it.
392 * This is a noop if the filter is disabled.
393 * Filter can be enabled only for the TAP devices. */
394 if (!check_filter(&tun->txflt, skb))
397 if (tun->socket.sk->sk_filter &&
398 sk_filter(tun->socket.sk, skb))
401 if (skb_queue_len(&tun->socket.sk->sk_receive_queue) >= dev->tx_queue_len) {
402 if (!(tun->flags & TUN_ONE_QUEUE)) {
403 /* Normal queueing mode. */
404 /* Packet scheduler handles dropping of further packets. */
405 netif_stop_queue(dev);
407 /* We won't see all dropped packets individually, so overrun
408 * error is more appropriate. */
409 dev->stats.tx_fifo_errors++;
411 /* Single queue mode.
412 * Driver handles dropping of all packets itself. */
417 /* Orphan the skb - required as we might hang on to it
418 * for indefinite time. */
424 skb_queue_tail(&tun->socket.sk->sk_receive_queue, skb);
426 /* Notify and wake up reader process */
427 if (tun->flags & TUN_FASYNC)
428 kill_fasync(&tun->fasync, SIGIO, POLL_IN);
429 wake_up_interruptible_poll(&tun->wq.wait, POLLIN |
430 POLLRDNORM | POLLRDBAND);
434 dev->stats.tx_dropped++;
439 static void tun_net_mclist(struct net_device *dev)
442 * This callback is supposed to deal with mc filter in
443 * _rx_ path and has nothing to do with the _tx_ path.
444 * In rx path we always accept everything userspace gives us.
449 #define MAX_MTU 65535
452 tun_net_change_mtu(struct net_device *dev, int new_mtu)
454 if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
460 static u32 tun_net_fix_features(struct net_device *dev, u32 features)
462 struct tun_struct *tun = netdev_priv(dev);
464 return (features & tun->set_features) | (features & ~TUN_USER_FEATURES);
466 #ifdef CONFIG_NET_POLL_CONTROLLER
467 static void tun_poll_controller(struct net_device *dev)
470 * Tun only receives frames when:
471 * 1) the char device endpoint gets data from user space
472 * 2) the tun socket gets a sendmsg call from user space
473 * Since both of those are syncronous operations, we are guaranteed
474 * never to have pending data when we poll for it
475 * so theres nothing to do here but return.
476 * We need this though so netpoll recognizes us as an interface that
477 * supports polling, which enables bridge devices in virt setups to
478 * still use netconsole
483 static const struct net_device_ops tun_netdev_ops = {
484 .ndo_uninit = tun_net_uninit,
485 .ndo_open = tun_net_open,
486 .ndo_stop = tun_net_close,
487 .ndo_start_xmit = tun_net_xmit,
488 .ndo_change_mtu = tun_net_change_mtu,
489 .ndo_fix_features = tun_net_fix_features,
490 #ifdef CONFIG_NET_POLL_CONTROLLER
491 .ndo_poll_controller = tun_poll_controller,
495 static const struct net_device_ops tap_netdev_ops = {
496 .ndo_uninit = tun_net_uninit,
497 .ndo_open = tun_net_open,
498 .ndo_stop = tun_net_close,
499 .ndo_start_xmit = tun_net_xmit,
500 .ndo_change_mtu = tun_net_change_mtu,
501 .ndo_fix_features = tun_net_fix_features,
502 .ndo_set_rx_mode = tun_net_mclist,
503 .ndo_set_mac_address = eth_mac_addr,
504 .ndo_validate_addr = eth_validate_addr,
505 #ifdef CONFIG_NET_POLL_CONTROLLER
506 .ndo_poll_controller = tun_poll_controller,
510 /* Initialize net device. */
511 static void tun_net_init(struct net_device *dev)
513 struct tun_struct *tun = netdev_priv(dev);
515 switch (tun->flags & TUN_TYPE_MASK) {
517 dev->netdev_ops = &tun_netdev_ops;
519 /* Point-to-Point TUN Device */
520 dev->hard_header_len = 0;
524 /* Zero header length */
525 dev->type = ARPHRD_NONE;
526 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
527 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
531 dev->netdev_ops = &tap_netdev_ops;
532 /* Ethernet TAP Device */
534 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
536 random_ether_addr(dev->dev_addr);
538 dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */
543 /* Character device part */
546 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
548 struct tun_file *tfile = file->private_data;
549 struct tun_struct *tun = __tun_get(tfile);
551 unsigned int mask = 0;
558 tun_debug(KERN_INFO, tun, "tun_chr_poll\n");
560 poll_wait(file, &tun->wq.wait, wait);
562 if (!skb_queue_empty(&sk->sk_receive_queue))
563 mask |= POLLIN | POLLRDNORM;
565 if (sock_writeable(sk) ||
566 (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
568 mask |= POLLOUT | POLLWRNORM;
570 if (tun->dev->reg_state != NETREG_REGISTERED)
577 /* prepad is the amount to reserve at front. len is length after that.
578 * linear is a hint as to how much to copy (usually headers). */
579 static struct sk_buff *tun_alloc_skb(struct tun_struct *tun,
580 size_t prepad, size_t len,
581 size_t linear, int noblock)
583 struct sock *sk = tun->socket.sk;
587 sock_update_classid(sk);
589 /* Under a page? Don't bother with paged skb. */
590 if (prepad + len < PAGE_SIZE || !linear)
593 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
598 skb_reserve(skb, prepad);
599 skb_put(skb, linear);
600 skb->data_len = len - linear;
601 skb->len += len - linear;
606 /* Get packet from user space buffer */
607 static ssize_t tun_get_user(struct tun_struct *tun,
608 const struct iovec *iv, size_t count,
611 struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
613 size_t len = count, align = NET_SKB_PAD;
614 struct virtio_net_hdr gso = { 0 };
617 if (!(tun->flags & TUN_NO_PI)) {
618 if (len < sizeof(pi))
622 if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
624 offset += sizeof(pi);
627 if (tun->flags & TUN_VNET_HDR) {
628 if (len < tun->vnet_hdr_sz)
630 len -= tun->vnet_hdr_sz;
632 if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
635 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
636 gso.csum_start + gso.csum_offset + 2 > gso.hdr_len)
637 gso.hdr_len = gso.csum_start + gso.csum_offset + 2;
639 if (gso.hdr_len > len)
641 offset += tun->vnet_hdr_sz;
644 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
645 align += NET_IP_ALIGN;
646 if (unlikely(len < ETH_HLEN ||
647 (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
651 skb = tun_alloc_skb(tun, align, len, gso.hdr_len, noblock);
653 if (PTR_ERR(skb) != -EAGAIN)
654 tun->dev->stats.rx_dropped++;
658 if (skb_copy_datagram_from_iovec(skb, 0, iv, offset, len)) {
659 tun->dev->stats.rx_dropped++;
664 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
665 if (!skb_partial_csum_set(skb, gso.csum_start,
667 tun->dev->stats.rx_frame_errors++;
673 switch (tun->flags & TUN_TYPE_MASK) {
675 if (tun->flags & TUN_NO_PI) {
676 switch (skb->data[0] & 0xf0) {
678 pi.proto = htons(ETH_P_IP);
681 pi.proto = htons(ETH_P_IPV6);
684 tun->dev->stats.rx_dropped++;
690 skb_reset_mac_header(skb);
691 skb->protocol = pi.proto;
695 skb->protocol = eth_type_trans(skb, tun->dev);
699 skb_reset_network_header(skb);
701 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
703 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
704 case VIRTIO_NET_HDR_GSO_TCPV4:
705 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
707 case VIRTIO_NET_HDR_GSO_TCPV6:
708 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
710 case VIRTIO_NET_HDR_GSO_UDP:
711 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
712 if (skb->protocol == htons(ETH_P_IPV6))
713 ipv6_proxy_select_ident(skb);
716 tun->dev->stats.rx_frame_errors++;
721 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
722 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
724 skb_shinfo(skb)->gso_size = gso.gso_size;
725 if (skb_shinfo(skb)->gso_size == 0) {
726 tun->dev->stats.rx_frame_errors++;
731 /* Header must be checked, and gso_segs computed. */
732 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
733 skb_shinfo(skb)->gso_segs = 0;
738 tun->dev->stats.rx_packets++;
739 tun->dev->stats.rx_bytes += len;
744 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
745 unsigned long count, loff_t pos)
747 struct file *file = iocb->ki_filp;
748 struct tun_struct *tun = tun_get(file);
754 tun_debug(KERN_INFO, tun, "tun_chr_write %ld\n", count);
756 result = tun_get_user(tun, iv, iov_length(iv, count),
757 file->f_flags & O_NONBLOCK);
763 /* Put packet to the user space buffer */
764 static ssize_t tun_put_user(struct tun_struct *tun,
766 const struct iovec *iv, int len)
768 struct tun_pi pi = { 0, skb->protocol };
771 if (!(tun->flags & TUN_NO_PI)) {
772 if ((len -= sizeof(pi)) < 0)
775 if (len < skb->len) {
776 /* Packet will be striped */
777 pi.flags |= TUN_PKT_STRIP;
780 if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi)))
785 if (tun->flags & TUN_VNET_HDR) {
786 struct virtio_net_hdr gso = { 0 }; /* no info leak */
787 if ((len -= tun->vnet_hdr_sz) < 0)
790 if (skb_is_gso(skb)) {
791 struct skb_shared_info *sinfo = skb_shinfo(skb);
793 /* This is a hint as to how much should be linear. */
794 gso.hdr_len = skb_headlen(skb);
795 gso.gso_size = sinfo->gso_size;
796 if (sinfo->gso_type & SKB_GSO_TCPV4)
797 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
798 else if (sinfo->gso_type & SKB_GSO_TCPV6)
799 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
800 else if (sinfo->gso_type & SKB_GSO_UDP)
801 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
803 pr_err("unexpected GSO type: "
804 "0x%x, gso_size %d, hdr_len %d\n",
805 sinfo->gso_type, gso.gso_size,
807 print_hex_dump(KERN_ERR, "tun: ",
810 min((int)gso.hdr_len, 64), true);
814 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
815 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
817 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
819 if (skb->ip_summed == CHECKSUM_PARTIAL) {
820 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
821 gso.csum_start = skb_checksum_start_offset(skb);
822 gso.csum_offset = skb->csum_offset;
823 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
824 gso.flags = VIRTIO_NET_HDR_F_DATA_VALID;
825 } /* else everything is zero */
827 if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
830 total += tun->vnet_hdr_sz;
833 len = min_t(int, skb->len, len);
835 skb_copy_datagram_const_iovec(skb, 0, iv, total, len);
838 tun->dev->stats.tx_packets++;
839 tun->dev->stats.tx_bytes += len;
844 static ssize_t tun_do_read(struct tun_struct *tun,
845 struct kiocb *iocb, const struct iovec *iv,
846 ssize_t len, int noblock)
848 DECLARE_WAITQUEUE(wait, current);
852 tun_debug(KERN_INFO, tun, "tun_chr_read\n");
854 if (unlikely(!noblock))
855 add_wait_queue(&tun->wq.wait, &wait);
857 current->state = TASK_INTERRUPTIBLE;
859 /* Read frames from the queue */
860 if (!(skb=skb_dequeue(&tun->socket.sk->sk_receive_queue))) {
865 if (signal_pending(current)) {
869 if (tun->dev->reg_state != NETREG_REGISTERED) {
874 /* Nothing to read, let's sleep */
878 netif_wake_queue(tun->dev);
880 ret = tun_put_user(tun, skb, iv, len);
885 current->state = TASK_RUNNING;
886 if (unlikely(!noblock))
887 remove_wait_queue(&tun->wq.wait, &wait);
892 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
893 unsigned long count, loff_t pos)
895 struct file *file = iocb->ki_filp;
896 struct tun_file *tfile = file->private_data;
897 struct tun_struct *tun = __tun_get(tfile);
902 len = iov_length(iv, count);
908 ret = tun_do_read(tun, iocb, iv, len, file->f_flags & O_NONBLOCK);
909 ret = min_t(ssize_t, ret, len);
915 static void tun_setup(struct net_device *dev)
917 struct tun_struct *tun = netdev_priv(dev);
922 dev->ethtool_ops = &tun_ethtool_ops;
923 dev->destructor = tun_free_netdev;
926 /* Trivial set of netlink ops to allow deleting tun or tap
927 * device with netlink.
929 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
934 static struct rtnl_link_ops tun_link_ops __read_mostly = {
936 .priv_size = sizeof(struct tun_struct),
938 .validate = tun_validate,
941 static void tun_sock_write_space(struct sock *sk)
943 struct tun_struct *tun;
944 wait_queue_head_t *wqueue;
946 if (!sock_writeable(sk))
949 if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
952 wqueue = sk_sleep(sk);
953 if (wqueue && waitqueue_active(wqueue))
954 wake_up_interruptible_sync_poll(wqueue, POLLOUT |
955 POLLWRNORM | POLLWRBAND);
957 tun = tun_sk(sk)->tun;
958 kill_fasync(&tun->fasync, SIGIO, POLL_OUT);
961 static void tun_sock_destruct(struct sock *sk)
963 free_netdev(tun_sk(sk)->tun->dev);
966 static int tun_sendmsg(struct kiocb *iocb, struct socket *sock,
967 struct msghdr *m, size_t total_len)
969 struct tun_struct *tun = container_of(sock, struct tun_struct, socket);
970 return tun_get_user(tun, m->msg_iov, total_len,
971 m->msg_flags & MSG_DONTWAIT);
974 static int tun_recvmsg(struct kiocb *iocb, struct socket *sock,
975 struct msghdr *m, size_t total_len,
978 struct tun_struct *tun = container_of(sock, struct tun_struct, socket);
980 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC))
982 ret = tun_do_read(tun, iocb, m->msg_iov, total_len,
983 flags & MSG_DONTWAIT);
984 if (ret > total_len) {
985 m->msg_flags |= MSG_TRUNC;
986 ret = flags & MSG_TRUNC ? ret : total_len;
991 /* Ops structure to mimic raw sockets with tun */
992 static const struct proto_ops tun_socket_ops = {
993 .sendmsg = tun_sendmsg,
994 .recvmsg = tun_recvmsg,
997 static struct proto tun_proto = {
999 .owner = THIS_MODULE,
1000 .obj_size = sizeof(struct tun_sock),
1003 static int tun_flags(struct tun_struct *tun)
1007 if (tun->flags & TUN_TUN_DEV)
1012 if (tun->flags & TUN_NO_PI)
1015 if (tun->flags & TUN_ONE_QUEUE)
1016 flags |= IFF_ONE_QUEUE;
1018 if (tun->flags & TUN_VNET_HDR)
1019 flags |= IFF_VNET_HDR;
1024 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
1027 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1028 return sprintf(buf, "0x%x\n", tun_flags(tun));
1031 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
1034 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1035 return sprintf(buf, "%d\n", tun->owner);
1038 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
1041 struct tun_struct *tun = netdev_priv(to_net_dev(dev));
1042 return sprintf(buf, "%d\n", tun->group);
1045 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
1046 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
1047 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
1049 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
1052 struct tun_struct *tun;
1053 struct net_device *dev;
1056 dev = __dev_get_by_name(net, ifr->ifr_name);
1058 const struct cred *cred = current_cred();
1060 if (ifr->ifr_flags & IFF_TUN_EXCL)
1062 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
1063 tun = netdev_priv(dev);
1064 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
1065 tun = netdev_priv(dev);
1069 if (((tun->owner != -1 && cred->euid != tun->owner) ||
1070 (tun->group != -1 && !in_egroup_p(tun->group))) &&
1071 !capable(CAP_NET_ADMIN))
1073 err = security_tun_dev_attach(tun->socket.sk);
1077 err = tun_attach(tun, file);
1083 unsigned long flags = 0;
1085 if (!capable(CAP_NET_ADMIN))
1087 err = security_tun_dev_create();
1092 if (ifr->ifr_flags & IFF_TUN) {
1094 flags |= TUN_TUN_DEV;
1096 } else if (ifr->ifr_flags & IFF_TAP) {
1098 flags |= TUN_TAP_DEV;
1104 name = ifr->ifr_name;
1106 dev = alloc_netdev(sizeof(struct tun_struct), name,
1111 dev_net_set(dev, net);
1112 dev->rtnl_link_ops = &tun_link_ops;
1114 tun = netdev_priv(dev);
1117 tun->txflt.count = 0;
1118 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
1121 sk = sk_alloc(net, AF_UNSPEC, GFP_KERNEL, &tun_proto);
1125 tun->socket.wq = &tun->wq;
1126 init_waitqueue_head(&tun->wq.wait);
1127 tun->socket.ops = &tun_socket_ops;
1128 sock_init_data(&tun->socket, sk);
1129 sk->sk_write_space = tun_sock_write_space;
1130 sk->sk_sndbuf = INT_MAX;
1132 tun_sk(sk)->tun = tun;
1134 security_tun_dev_post_create(sk);
1138 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
1140 dev->features = dev->hw_features;
1142 err = register_netdevice(tun->dev);
1146 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
1147 device_create_file(&tun->dev->dev, &dev_attr_owner) ||
1148 device_create_file(&tun->dev->dev, &dev_attr_group))
1149 pr_err("Failed to create tun sysfs files\n");
1151 sk->sk_destruct = tun_sock_destruct;
1153 err = tun_attach(tun, file);
1158 tun_debug(KERN_INFO, tun, "tun_set_iff\n");
1160 if (ifr->ifr_flags & IFF_NO_PI)
1161 tun->flags |= TUN_NO_PI;
1163 tun->flags &= ~TUN_NO_PI;
1165 if (ifr->ifr_flags & IFF_ONE_QUEUE)
1166 tun->flags |= TUN_ONE_QUEUE;
1168 tun->flags &= ~TUN_ONE_QUEUE;
1170 if (ifr->ifr_flags & IFF_VNET_HDR)
1171 tun->flags |= TUN_VNET_HDR;
1173 tun->flags &= ~TUN_VNET_HDR;
1175 /* Make sure persistent devices do not get stuck in
1178 if (netif_running(tun->dev))
1179 netif_wake_queue(tun->dev);
1181 strcpy(ifr->ifr_name, tun->dev->name);
1192 static int tun_get_iff(struct net *net, struct tun_struct *tun,
1195 tun_debug(KERN_INFO, tun, "tun_get_iff\n");
1197 strcpy(ifr->ifr_name, tun->dev->name);
1199 ifr->ifr_flags = tun_flags(tun);
1204 /* This is like a cut-down ethtool ops, except done via tun fd so no
1205 * privs required. */
1206 static int set_offload(struct tun_struct *tun, unsigned long arg)
1210 if (arg & TUN_F_CSUM) {
1211 features |= NETIF_F_HW_CSUM;
1214 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1215 if (arg & TUN_F_TSO_ECN) {
1216 features |= NETIF_F_TSO_ECN;
1217 arg &= ~TUN_F_TSO_ECN;
1219 if (arg & TUN_F_TSO4)
1220 features |= NETIF_F_TSO;
1221 if (arg & TUN_F_TSO6)
1222 features |= NETIF_F_TSO6;
1223 arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1226 if (arg & TUN_F_UFO) {
1227 features |= NETIF_F_UFO;
1232 /* This gives the user a way to test for new features in future by
1233 * trying to set them. */
1237 tun->set_features = features;
1238 netdev_update_features(tun->dev);
1243 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
1244 unsigned long arg, int ifreq_len)
1246 struct tun_file *tfile = file->private_data;
1247 struct tun_struct *tun;
1248 void __user* argp = (void __user*)arg;
1249 struct sock_fprog fprog;
1255 if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89) {
1256 if (copy_from_user(&ifr, argp, ifreq_len))
1259 memset(&ifr, 0, sizeof(ifr));
1261 if (cmd == TUNGETFEATURES) {
1262 /* Currently this just means: "what IFF flags are valid?".
1263 * This is needed because we never checked for invalid flags on
1265 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
1267 (unsigned int __user*)argp);
1272 tun = __tun_get(tfile);
1273 if (cmd == TUNSETIFF && !tun) {
1274 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1276 ret = tun_set_iff(tfile->net, file, &ifr);
1281 if (copy_to_user(argp, &ifr, ifreq_len))
1290 tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %d\n", cmd);
1295 ret = tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1299 if (copy_to_user(argp, &ifr, ifreq_len))
1304 /* Disable/Enable checksum */
1306 /* [unimplemented] */
1307 tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n",
1308 arg ? "disabled" : "enabled");
1312 /* Disable/Enable persist mode */
1314 tun->flags |= TUN_PERSIST;
1316 tun->flags &= ~TUN_PERSIST;
1318 tun_debug(KERN_INFO, tun, "persist %s\n",
1319 arg ? "enabled" : "disabled");
1323 /* Set owner of the device */
1324 tun->owner = (uid_t) arg;
1326 tun_debug(KERN_INFO, tun, "owner set to %d\n", tun->owner);
1330 /* Set group of the device */
1331 tun->group= (gid_t) arg;
1333 tun_debug(KERN_INFO, tun, "group set to %d\n", tun->group);
1337 /* Only allow setting the type when the interface is down */
1338 if (tun->dev->flags & IFF_UP) {
1339 tun_debug(KERN_INFO, tun,
1340 "Linktype set failed because interface is up\n");
1343 tun->dev->type = (int) arg;
1344 tun_debug(KERN_INFO, tun, "linktype set to %d\n",
1356 ret = set_offload(tun, arg);
1359 case TUNSETTXFILTER:
1360 /* Can be set only for TAPs */
1362 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1364 ret = update_filter(&tun->txflt, (void __user *)arg);
1368 /* Get hw address */
1369 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
1370 ifr.ifr_hwaddr.sa_family = tun->dev->type;
1371 if (copy_to_user(argp, &ifr, ifreq_len))
1376 /* Set hw address */
1377 tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n",
1378 ifr.ifr_hwaddr.sa_data);
1380 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
1384 sndbuf = tun->socket.sk->sk_sndbuf;
1385 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
1390 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
1395 tun->socket.sk->sk_sndbuf = sndbuf;
1398 case TUNGETVNETHDRSZ:
1399 vnet_hdr_sz = tun->vnet_hdr_sz;
1400 if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
1404 case TUNSETVNETHDRSZ:
1405 if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
1409 if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
1414 tun->vnet_hdr_sz = vnet_hdr_sz;
1417 case TUNATTACHFILTER:
1418 /* Can be set only for TAPs */
1420 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1423 if (copy_from_user(&fprog, argp, sizeof(fprog)))
1426 ret = sk_attach_filter(&fprog, tun->socket.sk);
1429 case TUNDETACHFILTER:
1430 /* Can be set only for TAPs */
1432 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1434 ret = sk_detach_filter(tun->socket.sk);
1449 static long tun_chr_ioctl(struct file *file,
1450 unsigned int cmd, unsigned long arg)
1452 return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
1455 #ifdef CONFIG_COMPAT
1456 static long tun_chr_compat_ioctl(struct file *file,
1457 unsigned int cmd, unsigned long arg)
1462 case TUNSETTXFILTER:
1467 arg = (unsigned long)compat_ptr(arg);
1470 arg = (compat_ulong_t)arg;
1475 * compat_ifreq is shorter than ifreq, so we must not access beyond
1476 * the end of that structure. All fields that are used in this
1477 * driver are compatible though, we don't need to convert the
1480 return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
1482 #endif /* CONFIG_COMPAT */
1484 static int tun_chr_fasync(int fd, struct file *file, int on)
1486 struct tun_struct *tun = tun_get(file);
1492 tun_debug(KERN_INFO, tun, "tun_chr_fasync %d\n", on);
1494 if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
1498 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
1501 tun->flags |= TUN_FASYNC;
1503 tun->flags &= ~TUN_FASYNC;
1510 static int tun_chr_open(struct inode *inode, struct file * file)
1512 struct tun_file *tfile;
1514 DBG1(KERN_INFO, "tunX: tun_chr_open\n");
1516 tfile = kmalloc(sizeof(*tfile), GFP_KERNEL);
1519 atomic_set(&tfile->count, 0);
1521 tfile->net = get_net(current->nsproxy->net_ns);
1522 file->private_data = tfile;
1526 static int tun_chr_close(struct inode *inode, struct file *file)
1528 struct tun_file *tfile = file->private_data;
1529 struct tun_struct *tun;
1531 tun = __tun_get(tfile);
1533 struct net_device *dev = tun->dev;
1535 tun_debug(KERN_INFO, tun, "tun_chr_close\n");
1539 /* If desirable, unregister the netdevice. */
1540 if (!(tun->flags & TUN_PERSIST)) {
1542 if (dev->reg_state == NETREG_REGISTERED)
1543 unregister_netdevice(dev);
1550 sock_put(tun->socket.sk);
1552 put_net(tfile->net);
1558 static const struct file_operations tun_fops = {
1559 .owner = THIS_MODULE,
1560 .llseek = no_llseek,
1561 .read = do_sync_read,
1562 .aio_read = tun_chr_aio_read,
1563 .write = do_sync_write,
1564 .aio_write = tun_chr_aio_write,
1565 .poll = tun_chr_poll,
1566 .unlocked_ioctl = tun_chr_ioctl,
1567 #ifdef CONFIG_COMPAT
1568 .compat_ioctl = tun_chr_compat_ioctl,
1570 .open = tun_chr_open,
1571 .release = tun_chr_close,
1572 .fasync = tun_chr_fasync
1575 static struct miscdevice tun_miscdev = {
1578 .nodename = "net/tun",
1582 /* ethtool interface */
1584 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1587 cmd->advertising = 0;
1588 ethtool_cmd_speed_set(cmd, SPEED_10);
1589 cmd->duplex = DUPLEX_FULL;
1590 cmd->port = PORT_TP;
1591 cmd->phy_address = 0;
1592 cmd->transceiver = XCVR_INTERNAL;
1593 cmd->autoneg = AUTONEG_DISABLE;
1599 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
1601 struct tun_struct *tun = netdev_priv(dev);
1603 strcpy(info->driver, DRV_NAME);
1604 strcpy(info->version, DRV_VERSION);
1605 strcpy(info->fw_version, "N/A");
1607 switch (tun->flags & TUN_TYPE_MASK) {
1609 strcpy(info->bus_info, "tun");
1612 strcpy(info->bus_info, "tap");
1617 static u32 tun_get_msglevel(struct net_device *dev)
1620 struct tun_struct *tun = netdev_priv(dev);
1627 static void tun_set_msglevel(struct net_device *dev, u32 value)
1630 struct tun_struct *tun = netdev_priv(dev);
1635 static const struct ethtool_ops tun_ethtool_ops = {
1636 .get_settings = tun_get_settings,
1637 .get_drvinfo = tun_get_drvinfo,
1638 .get_msglevel = tun_get_msglevel,
1639 .set_msglevel = tun_set_msglevel,
1640 .get_link = ethtool_op_get_link,
1644 static int __init tun_init(void)
1648 pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
1649 pr_info("%s\n", DRV_COPYRIGHT);
1651 ret = rtnl_link_register(&tun_link_ops);
1653 pr_err("Can't register link_ops\n");
1657 ret = misc_register(&tun_miscdev);
1659 pr_err("Can't register misc device %d\n", TUN_MINOR);
1664 rtnl_link_unregister(&tun_link_ops);
1669 static void tun_cleanup(void)
1671 misc_deregister(&tun_miscdev);
1672 rtnl_link_unregister(&tun_link_ops);
1675 /* Get an underlying socket object from tun file. Returns error unless file is
1676 * attached to a device. The returned object works like a packet socket, it
1677 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
1678 * holding a reference to the file for as long as the socket is in use. */
1679 struct socket *tun_get_socket(struct file *file)
1681 struct tun_struct *tun;
1682 if (file->f_op != &tun_fops)
1683 return ERR_PTR(-EINVAL);
1684 tun = tun_get(file);
1686 return ERR_PTR(-EBADFD);
1688 return &tun->socket;
1690 EXPORT_SYMBOL_GPL(tun_get_socket);
1692 module_init(tun_init);
1693 module_exit(tun_cleanup);
1694 MODULE_DESCRIPTION(DRV_DESCRIPTION);
1695 MODULE_AUTHOR(DRV_COPYRIGHT);
1696 MODULE_LICENSE("GPL");
1697 MODULE_ALIAS_MISCDEV(TUN_MINOR);
1698 MODULE_ALIAS("devname:net/tun");