tun.c 32.9 KB
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/*
 *  TUN - Universal TUN/TAP device driver.
 *  Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 *  GNU General Public License for more details.
 *
 *  $Id: tun.c,v 1.15 2002/03/01 02:44:24 maxk Exp $
 */

/*
 *  Changes:
 *
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 *  Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14
 *    Add TUNSETLINK ioctl to set the link encapsulation
 *
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 *  Mark Smith <markzzzsmith@yahoo.com.au>
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 *    Use random_ether_addr() for tap MAC address.
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 *
 *  Harald Roelle <harald.roelle@ifi.lmu.de>  2004/04/20
 *    Fixes in packet dropping, queue length setting and queue wakeup.
 *    Increased default tx queue length.
 *    Added ethtool API.
 *    Minor cleanups
 *
 *  Daniel Podlejski <underley@underley.eu.org>
 *    Modifications for 2.3.99-pre5 kernel.
 */

#define DRV_NAME	"tun"
#define DRV_VERSION	"1.6"
#define DRV_DESCRIPTION	"Universal TUN/TAP device driver"
#define DRV_COPYRIGHT	"(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>"

#include <linux/module.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/slab.h>
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#include <linux/smp_lock.h>
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#include <linux/poll.h>
#include <linux/fcntl.h>
#include <linux/init.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/miscdevice.h>
#include <linux/ethtool.h>
#include <linux/rtnetlink.h>
#include <linux/if.h>
#include <linux/if_arp.h>
#include <linux/if_ether.h>
#include <linux/if_tun.h>
#include <linux/crc32.h>
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#include <linux/nsproxy.h>
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#include <linux/virtio_net.h>
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#include <net/net_namespace.h>
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#include <net/netns/generic.h>
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#include <net/rtnetlink.h>
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#include <net/sock.h>
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#include <asm/system.h>
#include <asm/uaccess.h>

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/* Uncomment to enable debugging */
/* #define TUN_DEBUG 1 */

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#ifdef TUN_DEBUG
static int debug;
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#define DBG  if(tun->debug)printk
#define DBG1 if(debug==2)printk
#else
#define DBG( a... )
#define DBG1( a... )
#endif

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#define FLT_EXACT_COUNT 8
struct tap_filter {
	unsigned int    count;    /* Number of addrs. Zero means disabled */
	u32             mask[2];  /* Mask of the hashed addrs */
	unsigned char	addr[FLT_EXACT_COUNT][ETH_ALEN];
};

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struct tun_file {
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	atomic_t count;
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	struct tun_struct *tun;
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	struct net *net;
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};

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struct tun_sock;

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struct tun_struct {
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	struct tun_file		*tfile;
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	unsigned int 		flags;
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	uid_t			owner;
	gid_t			group;

	struct sk_buff_head	readq;

	struct net_device	*dev;
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	struct fasync_struct	*fasync;
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	struct tap_filter       txflt;
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	struct sock		*sk;
	struct socket		socket;
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#ifdef TUN_DEBUG
	int debug;
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#endif
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};
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struct tun_sock {
	struct sock		sk;
	struct tun_struct	*tun;
};

static inline struct tun_sock *tun_sk(struct sock *sk)
{
	return container_of(sk, struct tun_sock, sk);
}

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static int tun_attach(struct tun_struct *tun, struct file *file)
{
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	struct tun_file *tfile = file->private_data;
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	int err;
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	ASSERT_RTNL();

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	netif_tx_lock_bh(tun->dev);

	err = -EINVAL;
	if (tfile->tun)
		goto out;

	err = -EBUSY;
	if (tun->tfile)
		goto out;

	err = 0;
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	tfile->tun = tun;
	tun->tfile = tfile;
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	dev_hold(tun->dev);
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	sock_hold(tun->sk);
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	atomic_inc(&tfile->count);
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out:
	netif_tx_unlock_bh(tun->dev);
	return err;
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}

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static void __tun_detach(struct tun_struct *tun)
{
	/* Detach from net device */
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	netif_tx_lock_bh(tun->dev);
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	tun->tfile = NULL;
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	netif_tx_unlock_bh(tun->dev);
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	/* Drop read queue */
	skb_queue_purge(&tun->readq);
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	/* Drop the extra count on the net device */
	dev_put(tun->dev);
}

static void tun_detach(struct tun_struct *tun)
{
	rtnl_lock();
	__tun_detach(tun);
	rtnl_unlock();
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}

static struct tun_struct *__tun_get(struct tun_file *tfile)
{
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	struct tun_struct *tun = NULL;

	if (atomic_inc_not_zero(&tfile->count))
		tun = tfile->tun;

	return tun;
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}

static struct tun_struct *tun_get(struct file *file)
{
	return __tun_get(file->private_data);
}

static void tun_put(struct tun_struct *tun)
{
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	struct tun_file *tfile = tun->tfile;

	if (atomic_dec_and_test(&tfile->count))
		tun_detach(tfile->tun);
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}

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/* TAP filterting */
static void addr_hash_set(u32 *mask, const u8 *addr)
{
	int n = ether_crc(ETH_ALEN, addr) >> 26;
	mask[n >> 5] |= (1 << (n & 31));
}

static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
{
	int n = ether_crc(ETH_ALEN, addr) >> 26;
	return mask[n >> 5] & (1 << (n & 31));
}

static int update_filter(struct tap_filter *filter, void __user *arg)
{
	struct { u8 u[ETH_ALEN]; } *addr;
	struct tun_filter uf;
	int err, alen, n, nexact;

	if (copy_from_user(&uf, arg, sizeof(uf)))
		return -EFAULT;

	if (!uf.count) {
		/* Disabled */
		filter->count = 0;
		return 0;
	}

	alen = ETH_ALEN * uf.count;
	addr = kmalloc(alen, GFP_KERNEL);
	if (!addr)
		return -ENOMEM;

	if (copy_from_user(addr, arg + sizeof(uf), alen)) {
		err = -EFAULT;
		goto done;
	}

	/* The filter is updated without holding any locks. Which is
	 * perfectly safe. We disable it first and in the worst
	 * case we'll accept a few undesired packets. */
	filter->count = 0;
	wmb();

	/* Use first set of addresses as an exact filter */
	for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
		memcpy(filter->addr[n], addr[n].u, ETH_ALEN);

	nexact = n;

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	/* Remaining multicast addresses are hashed,
	 * unicast will leave the filter disabled. */
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	memset(filter->mask, 0, sizeof(filter->mask));
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	for (; n < uf.count; n++) {
		if (!is_multicast_ether_addr(addr[n].u)) {
			err = 0; /* no filter */
			goto done;
		}
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		addr_hash_set(filter->mask, addr[n].u);
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	}
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	/* For ALLMULTI just set the mask to all ones.
	 * This overrides the mask populated above. */
	if ((uf.flags & TUN_FLT_ALLMULTI))
		memset(filter->mask, ~0, sizeof(filter->mask));

	/* Now enable the filter */
	wmb();
	filter->count = nexact;

	/* Return the number of exact filters */
	err = nexact;

done:
	kfree(addr);
	return err;
}

/* Returns: 0 - drop, !=0 - accept */
static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
{
	/* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
	 * at this point. */
	struct ethhdr *eh = (struct ethhdr *) skb->data;
	int i;

	/* Exact match */
	for (i = 0; i < filter->count; i++)
		if (!compare_ether_addr(eh->h_dest, filter->addr[i]))
			return 1;

	/* Inexact match (multicast only) */
	if (is_multicast_ether_addr(eh->h_dest))
		return addr_hash_test(filter->mask, eh->h_dest);

	return 0;
}

/*
 * Checks whether the packet is accepted or not.
 * Returns: 0 - drop, !=0 - accept
 */
static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
{
	if (!filter->count)
		return 1;

	return run_filter(filter, skb);
}

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/* Network device part of the driver */

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static const struct ethtool_ops tun_ethtool_ops;
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/* Net device detach from fd. */
static void tun_net_uninit(struct net_device *dev)
{
	struct tun_struct *tun = netdev_priv(dev);
	struct tun_file *tfile = tun->tfile;

	/* Inform the methods they need to stop using the dev.
	 */
	if (tfile) {
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		wake_up_all(&tun->socket.wait);
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		if (atomic_dec_and_test(&tfile->count))
			__tun_detach(tun);
	}
}

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static void tun_free_netdev(struct net_device *dev)
{
	struct tun_struct *tun = netdev_priv(dev);

	sock_put(tun->sk);
}

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/* Net device open. */
static int tun_net_open(struct net_device *dev)
{
	netif_start_queue(dev);
	return 0;
}

/* Net device close. */
static int tun_net_close(struct net_device *dev)
{
	netif_stop_queue(dev);
	return 0;
}

/* Net device start xmit */
static int tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct tun_struct *tun = netdev_priv(dev);

	DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len);

	/* Drop packet if interface is not attached */
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	if (!tun->tfile)
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		goto drop;

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	/* Drop if the filter does not like it.
	 * This is a noop if the filter is disabled.
	 * Filter can be enabled only for the TAP devices. */
	if (!check_filter(&tun->txflt, skb))
		goto drop;

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	if (skb_queue_len(&tun->readq) >= dev->tx_queue_len) {
		if (!(tun->flags & TUN_ONE_QUEUE)) {
			/* Normal queueing mode. */
			/* Packet scheduler handles dropping of further packets. */
			netif_stop_queue(dev);

			/* We won't see all dropped packets individually, so overrun
			 * error is more appropriate. */
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			dev->stats.tx_fifo_errors++;
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		} else {
			/* Single queue mode.
			 * Driver handles dropping of all packets itself. */
			goto drop;
		}
	}

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	/* Enqueue packet */
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	skb_queue_tail(&tun->readq, skb);
	dev->trans_start = jiffies;

	/* Notify and wake up reader process */
	if (tun->flags & TUN_FASYNC)
		kill_fasync(&tun->fasync, SIGIO, POLL_IN);
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	wake_up_interruptible(&tun->socket.wait);
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	return 0;

drop:
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	dev->stats.tx_dropped++;
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	kfree_skb(skb);
	return 0;
}

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static void tun_net_mclist(struct net_device *dev)
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{
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	/*
	 * This callback is supposed to deal with mc filter in
	 * _rx_ path and has nothing to do with the _tx_ path.
	 * In rx path we always accept everything userspace gives us.
	 */
	return;
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}

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#define MIN_MTU 68
#define MAX_MTU 65535

static int
tun_net_change_mtu(struct net_device *dev, int new_mtu)
{
	if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
		return -EINVAL;
	dev->mtu = new_mtu;
	return 0;
}

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static const struct net_device_ops tun_netdev_ops = {
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	.ndo_uninit		= tun_net_uninit,
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	.ndo_open		= tun_net_open,
	.ndo_stop		= tun_net_close,
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	.ndo_start_xmit		= tun_net_xmit,
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	.ndo_change_mtu		= tun_net_change_mtu,
};

static const struct net_device_ops tap_netdev_ops = {
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	.ndo_uninit		= tun_net_uninit,
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	.ndo_open		= tun_net_open,
	.ndo_stop		= tun_net_close,
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	.ndo_start_xmit		= tun_net_xmit,
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	.ndo_change_mtu		= tun_net_change_mtu,
	.ndo_set_multicast_list	= tun_net_mclist,
	.ndo_set_mac_address	= eth_mac_addr,
	.ndo_validate_addr	= eth_validate_addr,
};

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/* Initialize net device. */
static void tun_net_init(struct net_device *dev)
{
	struct tun_struct *tun = netdev_priv(dev);
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	switch (tun->flags & TUN_TYPE_MASK) {
	case TUN_TUN_DEV:
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		dev->netdev_ops = &tun_netdev_ops;

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		/* Point-to-Point TUN Device */
		dev->hard_header_len = 0;
		dev->addr_len = 0;
		dev->mtu = 1500;

		/* Zero header length */
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		dev->type = ARPHRD_NONE;
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		dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
		dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
		break;

	case TUN_TAP_DEV:
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		dev->netdev_ops = &tap_netdev_ops;
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		/* Ethernet TAP Device */
		ether_setup(dev);
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		random_ether_addr(dev->dev_addr);
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		dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
		break;
	}
}

/* Character device part */

/* Poll */
static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
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{
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	struct tun_file *tfile = file->private_data;
	struct tun_struct *tun = __tun_get(tfile);
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	struct sock *sk;
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	unsigned int mask = 0;
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	if (!tun)
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		return POLLERR;
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	sk = tun->sk;

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	DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name);

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	poll_wait(file, &tun->socket.wait, wait);
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	if (!skb_queue_empty(&tun->readq))
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		mask |= POLLIN | POLLRDNORM;

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	if (sock_writeable(sk) ||
	    (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
	     sock_writeable(sk)))
		mask |= POLLOUT | POLLWRNORM;

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	if (tun->dev->reg_state != NETREG_REGISTERED)
		mask = POLLERR;

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	tun_put(tun);
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	return mask;
}

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/* prepad is the amount to reserve at front.  len is length after that.
 * linear is a hint as to how much to copy (usually headers). */
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static inline struct sk_buff *tun_alloc_skb(struct tun_struct *tun,
					    size_t prepad, size_t len,
					    size_t linear, int noblock)
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{
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	struct sock *sk = tun->sk;
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	struct sk_buff *skb;
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	int err;
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	/* Under a page?  Don't bother with paged skb. */
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	if (prepad + len < PAGE_SIZE || !linear)
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		linear = len;
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	skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
				   &err);
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	if (!skb)
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		return ERR_PTR(err);
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	skb_reserve(skb, prepad);
	skb_put(skb, linear);
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	skb->data_len = len - linear;
	skb->len += len - linear;
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	return skb;
}

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/* Get packet from user space buffer */
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static __inline__ ssize_t tun_get_user(struct tun_struct *tun,
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				       const struct iovec *iv, size_t count,
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				       int noblock)
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{
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	struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
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	struct sk_buff *skb;
	size_t len = count, align = 0;
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	struct virtio_net_hdr gso = { 0 };
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	int offset = 0;
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	if (!(tun->flags & TUN_NO_PI)) {
		if ((len -= sizeof(pi)) > count)
			return -EINVAL;

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		if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
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			return -EFAULT;
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		offset += sizeof(pi);
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	}

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	if (tun->flags & TUN_VNET_HDR) {
		if ((len -= sizeof(gso)) > count)
			return -EINVAL;

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		if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
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			return -EFAULT;

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		if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
		    gso.csum_start + gso.csum_offset + 2 > gso.hdr_len)
			gso.hdr_len = gso.csum_start + gso.csum_offset + 2;

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		if (gso.hdr_len > len)
			return -EINVAL;
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		offset += sizeof(gso);
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	}

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	if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
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		align = NET_IP_ALIGN;
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		if (unlikely(len < ETH_HLEN ||
			     (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
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			return -EINVAL;
	}
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	skb = tun_alloc_skb(tun, align, len, gso.hdr_len, noblock);
	if (IS_ERR(skb)) {
		if (PTR_ERR(skb) != -EAGAIN)
			tun->dev->stats.rx_dropped++;
		return PTR_ERR(skb);
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	}

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	if (skb_copy_datagram_from_iovec(skb, 0, iv, offset, len)) {
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		tun->dev->stats.rx_dropped++;
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		kfree_skb(skb);
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		return -EFAULT;
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	}
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	if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
		if (!skb_partial_csum_set(skb, gso.csum_start,
					  gso.csum_offset)) {
			tun->dev->stats.rx_frame_errors++;
			kfree_skb(skb);
			return -EINVAL;
		}
	} else if (tun->flags & TUN_NOCHECKSUM)
		skb->ip_summed = CHECKSUM_UNNECESSARY;

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	switch (tun->flags & TUN_TYPE_MASK) {
	case TUN_TUN_DEV:
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		if (tun->flags & TUN_NO_PI) {
			switch (skb->data[0] & 0xf0) {
			case 0x40:
				pi.proto = htons(ETH_P_IP);
				break;
			case 0x60:
				pi.proto = htons(ETH_P_IPV6);
				break;
			default:
				tun->dev->stats.rx_dropped++;
				kfree_skb(skb);
				return -EINVAL;
			}
		}

619
		skb_reset_mac_header(skb);
L
Linus Torvalds 已提交
620
		skb->protocol = pi.proto;
621
		skb->dev = tun->dev;
L
Linus Torvalds 已提交
622 623 624 625 626 627
		break;
	case TUN_TAP_DEV:
		skb->protocol = eth_type_trans(skb, tun->dev);
		break;
	};

628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656
	if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
		pr_debug("GSO!\n");
		switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
		case VIRTIO_NET_HDR_GSO_TCPV4:
			skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
			break;
		case VIRTIO_NET_HDR_GSO_TCPV6:
			skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
			break;
		default:
			tun->dev->stats.rx_frame_errors++;
			kfree_skb(skb);
			return -EINVAL;
		}

		if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
			skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;

		skb_shinfo(skb)->gso_size = gso.gso_size;
		if (skb_shinfo(skb)->gso_size == 0) {
			tun->dev->stats.rx_frame_errors++;
			kfree_skb(skb);
			return -EINVAL;
		}

		/* Header must be checked, and gso_segs computed. */
		skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
		skb_shinfo(skb)->gso_segs = 0;
	}
657

L
Linus Torvalds 已提交
658
	netif_rx_ni(skb);
659

660 661
	tun->dev->stats.rx_packets++;
	tun->dev->stats.rx_bytes += len;
L
Linus Torvalds 已提交
662 663

	return count;
664
}
L
Linus Torvalds 已提交
665

666 667
static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
			      unsigned long count, loff_t pos)
L
Linus Torvalds 已提交
668
{
669
	struct file *file = iocb->ki_filp;
H
Herbert Xu 已提交
670
	struct tun_struct *tun = tun_get(file);
E
Eric W. Biederman 已提交
671
	ssize_t result;
L
Linus Torvalds 已提交
672 673 674 675 676 677

	if (!tun)
		return -EBADFD;

	DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);

678
	result = tun_get_user(tun, iv, iov_length(iv, count),
679
			      file->f_flags & O_NONBLOCK);
E
Eric W. Biederman 已提交
680 681 682

	tun_put(tun);
	return result;
L
Linus Torvalds 已提交
683 684 685 686 687
}

/* Put packet to the user space buffer */
static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
				       struct sk_buff *skb,
688
				       const struct iovec *iv, int len)
L
Linus Torvalds 已提交
689 690 691 692 693 694 695 696 697 698 699 700
{
	struct tun_pi pi = { 0, skb->protocol };
	ssize_t total = 0;

	if (!(tun->flags & TUN_NO_PI)) {
		if ((len -= sizeof(pi)) < 0)
			return -EINVAL;

		if (len < skb->len) {
			/* Packet will be striped */
			pi.flags |= TUN_PKT_STRIP;
		}
701

702
		if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi)))
L
Linus Torvalds 已提交
703 704
			return -EFAULT;
		total += sizeof(pi);
705
	}
L
Linus Torvalds 已提交
706

707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734
	if (tun->flags & TUN_VNET_HDR) {
		struct virtio_net_hdr gso = { 0 }; /* no info leak */
		if ((len -= sizeof(gso)) < 0)
			return -EINVAL;

		if (skb_is_gso(skb)) {
			struct skb_shared_info *sinfo = skb_shinfo(skb);

			/* This is a hint as to how much should be linear. */
			gso.hdr_len = skb_headlen(skb);
			gso.gso_size = sinfo->gso_size;
			if (sinfo->gso_type & SKB_GSO_TCPV4)
				gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
			else if (sinfo->gso_type & SKB_GSO_TCPV6)
				gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
			else
				BUG();
			if (sinfo->gso_type & SKB_GSO_TCP_ECN)
				gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
		} else
			gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;

		if (skb->ip_summed == CHECKSUM_PARTIAL) {
			gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
			gso.csum_start = skb->csum_start - skb_headroom(skb);
			gso.csum_offset = skb->csum_offset;
		} /* else everything is zero */

735 736
		if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
					       sizeof(gso))))
737 738 739 740
			return -EFAULT;
		total += sizeof(gso);
	}

L
Linus Torvalds 已提交
741 742
	len = min_t(int, skb->len, len);

743
	skb_copy_datagram_const_iovec(skb, 0, iv, total, len);
L
Linus Torvalds 已提交
744 745
	total += len;

746 747
	tun->dev->stats.tx_packets++;
	tun->dev->stats.tx_bytes += len;
L
Linus Torvalds 已提交
748 749 750 751

	return total;
}

752 753
static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
			    unsigned long count, loff_t pos)
L
Linus Torvalds 已提交
754
{
755
	struct file *file = iocb->ki_filp;
756 757
	struct tun_file *tfile = file->private_data;
	struct tun_struct *tun = __tun_get(tfile);
L
Linus Torvalds 已提交
758 759 760 761 762 763 764 765 766
	DECLARE_WAITQUEUE(wait, current);
	struct sk_buff *skb;
	ssize_t len, ret = 0;

	if (!tun)
		return -EBADFD;

	DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);

A
Akinobu Mita 已提交
767
	len = iov_length(iv, count);
E
Eric W. Biederman 已提交
768 769 770 771
	if (len < 0) {
		ret = -EINVAL;
		goto out;
	}
L
Linus Torvalds 已提交
772

773
	add_wait_queue(&tun->socket.wait, &wait);
L
Linus Torvalds 已提交
774 775 776 777 778 779 780 781 782 783 784 785 786
	while (len) {
		current->state = TASK_INTERRUPTIBLE;

		/* Read frames from the queue */
		if (!(skb=skb_dequeue(&tun->readq))) {
			if (file->f_flags & O_NONBLOCK) {
				ret = -EAGAIN;
				break;
			}
			if (signal_pending(current)) {
				ret = -ERESTARTSYS;
				break;
			}
787 788 789 790
			if (tun->dev->reg_state != NETREG_REGISTERED) {
				ret = -EIO;
				break;
			}
L
Linus Torvalds 已提交
791 792 793 794 795 796 797

			/* Nothing to read, let's sleep */
			schedule();
			continue;
		}
		netif_wake_queue(tun->dev);

798
		ret = tun_put_user(tun, skb, iv, len);
799 800
		kfree_skb(skb);
		break;
L
Linus Torvalds 已提交
801 802 803
	}

	current->state = TASK_RUNNING;
804
	remove_wait_queue(&tun->socket.wait, &wait);
L
Linus Torvalds 已提交
805

E
Eric W. Biederman 已提交
806 807
out:
	tun_put(tun);
L
Linus Torvalds 已提交
808 809 810 811 812 813 814 815 816 817
	return ret;
}

static void tun_setup(struct net_device *dev)
{
	struct tun_struct *tun = netdev_priv(dev);

	skb_queue_head_init(&tun->readq);

	tun->owner = -1;
818
	tun->group = -1;
L
Linus Torvalds 已提交
819 820

	dev->ethtool_ops = &tun_ethtool_ops;
821
	dev->destructor = tun_free_netdev;
L
Linus Torvalds 已提交
822 823
}

824 825 826 827 828 829 830 831 832 833 834 835 836 837 838
/* Trivial set of netlink ops to allow deleting tun or tap
 * device with netlink.
 */
static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
{
	return -EINVAL;
}

static struct rtnl_link_ops tun_link_ops __read_mostly = {
	.kind		= DRV_NAME,
	.priv_size	= sizeof(struct tun_struct),
	.setup		= tun_setup,
	.validate	= tun_validate,
};

839 840 841 842 843 844 845 846 847 848
static void tun_sock_write_space(struct sock *sk)
{
	struct tun_struct *tun;

	if (!sock_writeable(sk))
		return;

	if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
		return;

H
Herbert Xu 已提交
849 850 851
	if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
		wake_up_interruptible_sync(sk->sk_sleep);

852 853 854 855 856 857
	tun = container_of(sk, struct tun_sock, sk)->tun;
	kill_fasync(&tun->fasync, SIGIO, POLL_OUT);
}

static void tun_sock_destruct(struct sock *sk)
{
858
	free_netdev(container_of(sk, struct tun_sock, sk)->tun->dev);
859 860 861 862 863 864 865
}

static struct proto tun_proto = {
	.name		= "tun",
	.owner		= THIS_MODULE,
	.obj_size	= sizeof(struct tun_sock),
};
866

867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912
static int tun_flags(struct tun_struct *tun)
{
	int flags = 0;

	if (tun->flags & TUN_TUN_DEV)
		flags |= IFF_TUN;
	else
		flags |= IFF_TAP;

	if (tun->flags & TUN_NO_PI)
		flags |= IFF_NO_PI;

	if (tun->flags & TUN_ONE_QUEUE)
		flags |= IFF_ONE_QUEUE;

	if (tun->flags & TUN_VNET_HDR)
		flags |= IFF_VNET_HDR;

	return flags;
}

static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
			      char *buf)
{
	struct tun_struct *tun = netdev_priv(to_net_dev(dev));
	return sprintf(buf, "0x%x\n", tun_flags(tun));
}

static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
			      char *buf)
{
	struct tun_struct *tun = netdev_priv(to_net_dev(dev));
	return sprintf(buf, "%d\n", tun->owner);
}

static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
			      char *buf)
{
	struct tun_struct *tun = netdev_priv(to_net_dev(dev));
	return sprintf(buf, "%d\n", tun->group);
}

static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
static DEVICE_ATTR(group, 0444, tun_show_group, NULL);

913
static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
L
Linus Torvalds 已提交
914
{
915
	struct sock *sk;
L
Linus Torvalds 已提交
916 917 918 919
	struct tun_struct *tun;
	struct net_device *dev;
	int err;

920 921
	dev = __dev_get_by_name(net, ifr->ifr_name);
	if (dev) {
P
Paul Moore 已提交
922 923
		const struct cred *cred = current_cred();

924 925
		if (ifr->ifr_flags & IFF_TUN_EXCL)
			return -EBUSY;
926 927 928 929 930 931 932
		if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
			tun = netdev_priv(dev);
		else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
			tun = netdev_priv(dev);
		else
			return -EINVAL;

P
Paul Moore 已提交
933 934 935 936 937 938 939 940
		if (((tun->owner != -1 && cred->euid != tun->owner) ||
		     (tun->group != -1 && !in_egroup_p(tun->group))) &&
		    !capable(CAP_NET_ADMIN))
			return -EPERM;
		err = security_tun_dev_attach(tun->sk);
		if (err < 0)
			return err;

941 942 943
		err = tun_attach(tun, file);
		if (err < 0)
			return err;
944
	}
L
Linus Torvalds 已提交
945 946 947 948 949 950
	else {
		char *name;
		unsigned long flags = 0;

		err = -EINVAL;

951 952
		if (!capable(CAP_NET_ADMIN))
			return -EPERM;
P
Paul Moore 已提交
953 954 955
		err = security_tun_dev_create();
		if (err < 0)
			return err;
956

L
Linus Torvalds 已提交
957 958 959 960 961 962 963 964 965
		/* Set dev type */
		if (ifr->ifr_flags & IFF_TUN) {
			/* TUN device */
			flags |= TUN_TUN_DEV;
			name = "tun%d";
		} else if (ifr->ifr_flags & IFF_TAP) {
			/* TAP device */
			flags |= TUN_TAP_DEV;
			name = "tap%d";
966
		} else
L
Linus Torvalds 已提交
967
			goto failed;
968

L
Linus Torvalds 已提交
969 970 971 972 973 974 975 976
		if (*ifr->ifr_name)
			name = ifr->ifr_name;

		dev = alloc_netdev(sizeof(struct tun_struct), name,
				   tun_setup);
		if (!dev)
			return -ENOMEM;

977
		dev_net_set(dev, net);
978
		dev->rtnl_link_ops = &tun_link_ops;
S
Stephen Hemminger 已提交
979

L
Linus Torvalds 已提交
980 981 982
		tun = netdev_priv(dev);
		tun->dev = dev;
		tun->flags = flags;
983
		tun->txflt.count = 0;
L
Linus Torvalds 已提交
984

985 986 987 988 989
		err = -ENOMEM;
		sk = sk_alloc(net, AF_UNSPEC, GFP_KERNEL, &tun_proto);
		if (!sk)
			goto err_free_dev;

990
		init_waitqueue_head(&tun->socket.wait);
991 992 993 994 995 996 997
		sock_init_data(&tun->socket, sk);
		sk->sk_write_space = tun_sock_write_space;
		sk->sk_sndbuf = INT_MAX;

		tun->sk = sk;
		container_of(sk, struct tun_sock, sk)->tun = tun;

P
Paul Moore 已提交
998 999
		security_tun_dev_post_create(sk);

L
Linus Torvalds 已提交
1000 1001 1002 1003 1004
		tun_net_init(dev);

		if (strchr(dev->name, '%')) {
			err = dev_alloc_name(dev, dev->name);
			if (err < 0)
1005
				goto err_free_sk;
L
Linus Torvalds 已提交
1006 1007
		}

1008
		err = -EINVAL;
L
Linus Torvalds 已提交
1009 1010
		err = register_netdevice(tun->dev);
		if (err < 0)
1011 1012
			goto err_free_sk;

1013 1014 1015 1016 1017
		if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
		    device_create_file(&tun->dev->dev, &dev_attr_owner) ||
		    device_create_file(&tun->dev->dev, &dev_attr_group))
			printk(KERN_ERR "Failed to create tun sysfs files\n");

1018
		sk->sk_destruct = tun_sock_destruct;
1019 1020 1021

		err = tun_attach(tun, file);
		if (err < 0)
1022
			goto failed;
L
Linus Torvalds 已提交
1023 1024 1025 1026 1027 1028
	}

	DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);

	if (ifr->ifr_flags & IFF_NO_PI)
		tun->flags |= TUN_NO_PI;
1029 1030
	else
		tun->flags &= ~TUN_NO_PI;
L
Linus Torvalds 已提交
1031 1032 1033

	if (ifr->ifr_flags & IFF_ONE_QUEUE)
		tun->flags |= TUN_ONE_QUEUE;
1034 1035
	else
		tun->flags &= ~TUN_ONE_QUEUE;
L
Linus Torvalds 已提交
1036

1037 1038 1039 1040 1041
	if (ifr->ifr_flags & IFF_VNET_HDR)
		tun->flags |= TUN_VNET_HDR;
	else
		tun->flags &= ~TUN_VNET_HDR;

1042 1043 1044 1045 1046 1047
	/* Make sure persistent devices do not get stuck in
	 * xoff state.
	 */
	if (netif_running(tun->dev))
		netif_wake_queue(tun->dev);

L
Linus Torvalds 已提交
1048 1049 1050
	strcpy(ifr->ifr_name, tun->dev->name);
	return 0;

1051 1052
 err_free_sk:
	sock_put(sk);
L
Linus Torvalds 已提交
1053 1054 1055 1056 1057 1058
 err_free_dev:
	free_netdev(dev);
 failed:
	return err;
}

1059 1060
static int tun_get_iff(struct net *net, struct tun_struct *tun,
		       struct ifreq *ifr)
1061 1062 1063 1064 1065
{
	DBG(KERN_INFO "%s: tun_get_iff\n", tun->dev->name);

	strcpy(ifr->ifr_name, tun->dev->name);

1066
	ifr->ifr_flags = tun_flags(tun);
1067 1068 1069 1070

	return 0;
}

1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110
/* This is like a cut-down ethtool ops, except done via tun fd so no
 * privs required. */
static int set_offload(struct net_device *dev, unsigned long arg)
{
	unsigned int old_features, features;

	old_features = dev->features;
	/* Unset features, set them as we chew on the arg. */
	features = (old_features & ~(NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST
				    |NETIF_F_TSO_ECN|NETIF_F_TSO|NETIF_F_TSO6));

	if (arg & TUN_F_CSUM) {
		features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
		arg &= ~TUN_F_CSUM;

		if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
			if (arg & TUN_F_TSO_ECN) {
				features |= NETIF_F_TSO_ECN;
				arg &= ~TUN_F_TSO_ECN;
			}
			if (arg & TUN_F_TSO4)
				features |= NETIF_F_TSO;
			if (arg & TUN_F_TSO6)
				features |= NETIF_F_TSO6;
			arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
		}
	}

	/* This gives the user a way to test for new features in future by
	 * trying to set them. */
	if (arg)
		return -EINVAL;

	dev->features = features;
	if (old_features != dev->features)
		netdev_features_change(dev);

	return 0;
}

1111 1112
static long tun_chr_ioctl(struct file *file, unsigned int cmd,
			  unsigned long arg)
L
Linus Torvalds 已提交
1113
{
E
Eric W. Biederman 已提交
1114
	struct tun_file *tfile = file->private_data;
E
Eric W. Biederman 已提交
1115
	struct tun_struct *tun;
L
Linus Torvalds 已提交
1116 1117
	void __user* argp = (void __user*)arg;
	struct ifreq ifr;
1118
	int sndbuf;
1119
	int ret;
L
Linus Torvalds 已提交
1120 1121 1122 1123 1124

	if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
		if (copy_from_user(&ifr, argp, sizeof ifr))
			return -EFAULT;

E
Eric W. Biederman 已提交
1125 1126 1127 1128 1129 1130 1131 1132 1133
	if (cmd == TUNGETFEATURES) {
		/* Currently this just means: "what IFF flags are valid?".
		 * This is needed because we never checked for invalid flags on
		 * TUNSETIFF. */
		return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
				IFF_VNET_HDR,
				(unsigned int __user*)argp);
	}

1134 1135
	rtnl_lock();

E
Eric W. Biederman 已提交
1136
	tun = __tun_get(tfile);
L
Linus Torvalds 已提交
1137 1138 1139
	if (cmd == TUNSETIFF && !tun) {
		ifr.ifr_name[IFNAMSIZ-1] = '\0';

1140
		ret = tun_set_iff(tfile->net, file, &ifr);
L
Linus Torvalds 已提交
1141

1142 1143
		if (ret)
			goto unlock;
L
Linus Torvalds 已提交
1144 1145

		if (copy_to_user(argp, &ifr, sizeof(ifr)))
1146 1147
			ret = -EFAULT;
		goto unlock;
L
Linus Torvalds 已提交
1148 1149
	}

1150
	ret = -EBADFD;
L
Linus Torvalds 已提交
1151
	if (!tun)
1152
		goto unlock;
L
Linus Torvalds 已提交
1153 1154 1155

	DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd);

E
Eric W. Biederman 已提交
1156
	ret = 0;
L
Linus Torvalds 已提交
1157
	switch (cmd) {
1158
	case TUNGETIFF:
1159
		ret = tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1160
		if (ret)
E
Eric W. Biederman 已提交
1161
			break;
1162 1163

		if (copy_to_user(argp, &ifr, sizeof(ifr)))
E
Eric W. Biederman 已提交
1164
			ret = -EFAULT;
1165 1166
		break;

L
Linus Torvalds 已提交
1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185
	case TUNSETNOCSUM:
		/* Disable/Enable checksum */
		if (arg)
			tun->flags |= TUN_NOCHECKSUM;
		else
			tun->flags &= ~TUN_NOCHECKSUM;

		DBG(KERN_INFO "%s: checksum %s\n",
		    tun->dev->name, arg ? "disabled" : "enabled");
		break;

	case TUNSETPERSIST:
		/* Disable/Enable persist mode */
		if (arg)
			tun->flags |= TUN_PERSIST;
		else
			tun->flags &= ~TUN_PERSIST;

		DBG(KERN_INFO "%s: persist %s\n",
T
Toyo Abe 已提交
1186
		    tun->dev->name, arg ? "enabled" : "disabled");
L
Linus Torvalds 已提交
1187 1188 1189 1190 1191 1192 1193 1194 1195
		break;

	case TUNSETOWNER:
		/* Set owner of the device */
		tun->owner = (uid_t) arg;

		DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner);
		break;

1196 1197 1198 1199 1200 1201 1202
	case TUNSETGROUP:
		/* Set group of the device */
		tun->group= (gid_t) arg;

		DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group);
		break;

1203 1204 1205 1206 1207
	case TUNSETLINK:
		/* Only allow setting the type when the interface is down */
		if (tun->dev->flags & IFF_UP) {
			DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
				tun->dev->name);
1208
			ret = -EBUSY;
1209 1210 1211
		} else {
			tun->dev->type = (int) arg;
			DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
1212
			ret = 0;
1213
		}
E
Eric W. Biederman 已提交
1214
		break;
1215

L
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1216 1217 1218 1219 1220
#ifdef TUN_DEBUG
	case TUNSETDEBUG:
		tun->debug = arg;
		break;
#endif
1221 1222
	case TUNSETOFFLOAD:
		ret = set_offload(tun->dev, arg);
E
Eric W. Biederman 已提交
1223
		break;
1224

1225 1226
	case TUNSETTXFILTER:
		/* Can be set only for TAPs */
E
Eric W. Biederman 已提交
1227
		ret = -EINVAL;
1228
		if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
E
Eric W. Biederman 已提交
1229
			break;
H
Harvey Harrison 已提交
1230
		ret = update_filter(&tun->txflt, (void __user *)arg);
E
Eric W. Biederman 已提交
1231
		break;
L
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1232 1233

	case SIOCGIFHWADDR:
1234 1235 1236 1237
		/* Get hw addres */
		memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
		ifr.ifr_hwaddr.sa_family = tun->dev->type;
		if (copy_to_user(argp, &ifr, sizeof ifr))
E
Eric W. Biederman 已提交
1238 1239
			ret = -EFAULT;
		break;
L
Linus Torvalds 已提交
1240 1241

	case SIOCSIFHWADDR:
1242
		/* Set hw address */
J
Johannes Berg 已提交
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		DBG(KERN_DEBUG "%s: set hw address: %pM\n",
			tun->dev->name, ifr.ifr_hwaddr.sa_data);
1245 1246

		ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
E
Eric W. Biederman 已提交
1247
		break;
1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263

	case TUNGETSNDBUF:
		sndbuf = tun->sk->sk_sndbuf;
		if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
			ret = -EFAULT;
		break;

	case TUNSETSNDBUF:
		if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
			ret = -EFAULT;
			break;
		}

		tun->sk->sk_sndbuf = sndbuf;
		break;

L
Linus Torvalds 已提交
1264
	default:
E
Eric W. Biederman 已提交
1265 1266
		ret = -EINVAL;
		break;
L
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1267 1268
	};

1269 1270 1271 1272
unlock:
	rtnl_unlock();
	if (tun)
		tun_put(tun);
E
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1273
	return ret;
L
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1274 1275 1276 1277
}

static int tun_chr_fasync(int fd, struct file *file, int on)
{
E
Eric W. Biederman 已提交
1278
	struct tun_struct *tun = tun_get(file);
L
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1279 1280 1281 1282 1283 1284 1285
	int ret;

	if (!tun)
		return -EBADFD;

	DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);

J
Jonathan Corbet 已提交
1286
	lock_kernel();
L
Linus Torvalds 已提交
1287
	if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
J
Jonathan Corbet 已提交
1288
		goto out;
1289

L
Linus Torvalds 已提交
1290
	if (on) {
1291
		ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
L
Linus Torvalds 已提交
1292
		if (ret)
J
Jonathan Corbet 已提交
1293
			goto out;
L
Linus Torvalds 已提交
1294
		tun->flags |= TUN_FASYNC;
1295
	} else
L
Linus Torvalds 已提交
1296
		tun->flags &= ~TUN_FASYNC;
J
Jonathan Corbet 已提交
1297 1298 1299
	ret = 0;
out:
	unlock_kernel();
E
Eric W. Biederman 已提交
1300
	tun_put(tun);
J
Jonathan Corbet 已提交
1301
	return ret;
L
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1302 1303 1304 1305
}

static int tun_chr_open(struct inode *inode, struct file * file)
{
E
Eric W. Biederman 已提交
1306
	struct tun_file *tfile;
A
Arnd Bergmann 已提交
1307
	cycle_kernel_lock();
L
Linus Torvalds 已提交
1308
	DBG1(KERN_INFO "tunX: tun_chr_open\n");
E
Eric W. Biederman 已提交
1309 1310 1311 1312

	tfile = kmalloc(sizeof(*tfile), GFP_KERNEL);
	if (!tfile)
		return -ENOMEM;
1313
	atomic_set(&tfile->count, 0);
E
Eric W. Biederman 已提交
1314
	tfile->tun = NULL;
E
Eric W. Biederman 已提交
1315
	tfile->net = get_net(current->nsproxy->net_ns);
E
Eric W. Biederman 已提交
1316
	file->private_data = tfile;
L
Linus Torvalds 已提交
1317 1318 1319 1320 1321
	return 0;
}

static int tun_chr_close(struct inode *inode, struct file *file)
{
E
Eric W. Biederman 已提交
1322
	struct tun_file *tfile = file->private_data;
E
Eric W. Biederman 已提交
1323
	struct tun_struct *tun;
L
Linus Torvalds 已提交
1324

E
Eric W. Biederman 已提交
1325
	tun = __tun_get(tfile);
E
Eric W. Biederman 已提交
1326
	if (tun) {
H
Herbert Xu 已提交
1327 1328 1329
		struct net_device *dev = tun->dev;

		DBG(KERN_INFO "%s: tun_chr_close\n", dev->name);
L
Linus Torvalds 已提交
1330

E
Eric W. Biederman 已提交
1331
		__tun_detach(tun);
L
Linus Torvalds 已提交
1332

E
Eric W. Biederman 已提交
1333
		/* If desireable, unregister the netdevice. */
H
Herbert Xu 已提交
1334 1335 1336 1337 1338 1339
		if (!(tun->flags & TUN_PERSIST)) {
			rtnl_lock();
			if (dev->reg_state == NETREG_REGISTERED)
				unregister_netdevice(dev);
			rtnl_unlock();
		}
E
Eric W. Biederman 已提交
1340
	}
L
Linus Torvalds 已提交
1341

1342 1343 1344 1345
	tun = tfile->tun;
	if (tun)
		sock_put(tun->sk);

E
Eric W. Biederman 已提交
1346
	put_net(tfile->net);
E
Eric W. Biederman 已提交
1347
	kfree(tfile);
L
Linus Torvalds 已提交
1348 1349 1350 1351

	return 0;
}

1352
static const struct file_operations tun_fops = {
1353
	.owner	= THIS_MODULE,
L
Linus Torvalds 已提交
1354
	.llseek = no_llseek,
1355 1356 1357 1358
	.read  = do_sync_read,
	.aio_read  = tun_chr_aio_read,
	.write = do_sync_write,
	.aio_write = tun_chr_aio_write,
L
Linus Torvalds 已提交
1359
	.poll	= tun_chr_poll,
1360
	.unlocked_ioctl = tun_chr_ioctl,
L
Linus Torvalds 已提交
1361 1362
	.open	= tun_chr_open,
	.release = tun_chr_close,
1363
	.fasync = tun_chr_fasync
L
Linus Torvalds 已提交
1364 1365 1366 1367 1368
};

static struct miscdevice tun_miscdev = {
	.minor = TUN_MINOR,
	.name = "tun",
1369
	.devnode = "net/tun",
L
Linus Torvalds 已提交
1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428
	.fops = &tun_fops,
};

/* ethtool interface */

static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
{
	cmd->supported		= 0;
	cmd->advertising	= 0;
	cmd->speed		= SPEED_10;
	cmd->duplex		= DUPLEX_FULL;
	cmd->port		= PORT_TP;
	cmd->phy_address	= 0;
	cmd->transceiver	= XCVR_INTERNAL;
	cmd->autoneg		= AUTONEG_DISABLE;
	cmd->maxtxpkt		= 0;
	cmd->maxrxpkt		= 0;
	return 0;
}

static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
{
	struct tun_struct *tun = netdev_priv(dev);

	strcpy(info->driver, DRV_NAME);
	strcpy(info->version, DRV_VERSION);
	strcpy(info->fw_version, "N/A");

	switch (tun->flags & TUN_TYPE_MASK) {
	case TUN_TUN_DEV:
		strcpy(info->bus_info, "tun");
		break;
	case TUN_TAP_DEV:
		strcpy(info->bus_info, "tap");
		break;
	}
}

static u32 tun_get_msglevel(struct net_device *dev)
{
#ifdef TUN_DEBUG
	struct tun_struct *tun = netdev_priv(dev);
	return tun->debug;
#else
	return -EOPNOTSUPP;
#endif
}

static void tun_set_msglevel(struct net_device *dev, u32 value)
{
#ifdef TUN_DEBUG
	struct tun_struct *tun = netdev_priv(dev);
	tun->debug = value;
#endif
}

static u32 tun_get_link(struct net_device *dev)
{
	struct tun_struct *tun = netdev_priv(dev);
E
Eric W. Biederman 已提交
1429
	return !!tun->tfile;
L
Linus Torvalds 已提交
1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447
}

static u32 tun_get_rx_csum(struct net_device *dev)
{
	struct tun_struct *tun = netdev_priv(dev);
	return (tun->flags & TUN_NOCHECKSUM) == 0;
}

static int tun_set_rx_csum(struct net_device *dev, u32 data)
{
	struct tun_struct *tun = netdev_priv(dev);
	if (data)
		tun->flags &= ~TUN_NOCHECKSUM;
	else
		tun->flags |= TUN_NOCHECKSUM;
	return 0;
}

1448
static const struct ethtool_ops tun_ethtool_ops = {
L
Linus Torvalds 已提交
1449 1450 1451 1452 1453 1454 1455 1456 1457
	.get_settings	= tun_get_settings,
	.get_drvinfo	= tun_get_drvinfo,
	.get_msglevel	= tun_get_msglevel,
	.set_msglevel	= tun_set_msglevel,
	.get_link	= tun_get_link,
	.get_rx_csum	= tun_get_rx_csum,
	.set_rx_csum	= tun_set_rx_csum
};

1458

L
Linus Torvalds 已提交
1459 1460 1461 1462 1463 1464 1465
static int __init tun_init(void)
{
	int ret = 0;

	printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
	printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);

1466
	ret = rtnl_link_register(&tun_link_ops);
1467
	if (ret) {
1468 1469
		printk(KERN_ERR "tun: Can't register link_ops\n");
		goto err_linkops;
1470 1471
	}

L
Linus Torvalds 已提交
1472
	ret = misc_register(&tun_miscdev);
1473
	if (ret) {
L
Linus Torvalds 已提交
1474
		printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
1475 1476
		goto err_misc;
	}
1477
	return  0;
1478
err_misc:
1479 1480
	rtnl_link_unregister(&tun_link_ops);
err_linkops:
L
Linus Torvalds 已提交
1481 1482 1483 1484 1485
	return ret;
}

static void tun_cleanup(void)
{
1486
	misc_deregister(&tun_miscdev);
1487
	rtnl_link_unregister(&tun_link_ops);
L
Linus Torvalds 已提交
1488 1489 1490 1491 1492 1493 1494 1495
}

module_init(tun_init);
module_exit(tun_cleanup);
MODULE_DESCRIPTION(DRV_DESCRIPTION);
MODULE_AUTHOR(DRV_COPYRIGHT);
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(TUN_MINOR);