kernel-fxtec-pro1x/drivers/net/tun.c
Ang Way Chuang f09f7ee20c tun: Proper handling of IPv6 header in tun driver when TUN_NO_PI is set
By default, tun.c running in TUN_TUN_DEV mode will set the protocol of
packet to IPv4 if TUN_NO_PI is set. My program failed to work when I
assumed that the driver will check the first nibble of packet,
determine IP version and set the appropriate protocol.

Signed-off-by: Ang Way Chuang <wcang@nav6.org>
Acked-by: Max Krasnyansky <maxk@qualcomm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-06-17 21:10:33 -07:00

1033 lines
23 KiB
C

/*
* 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:
*
* Brian Braunstein <linuxkernel@bristyle.com> 2007/03/23
* Fixed hw address handling. Now net_device.dev_addr is kept consistent
* with tun.dev_addr when the address is set by this module.
*
* Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14
* Add TUNSETLINK ioctl to set the link encapsulation
*
* Mark Smith <markzzzsmith@yahoo.com.au>
* Use random_ether_addr() for tap MAC address.
*
* 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>
#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>
#include <linux/nsproxy.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>
#include <asm/system.h>
#include <asm/uaccess.h>
/* Uncomment to enable debugging */
/* #define TUN_DEBUG 1 */
#ifdef TUN_DEBUG
static int debug;
#define DBG if(tun->debug)printk
#define DBG1 if(debug==2)printk
#else
#define DBG( a... )
#define DBG1( a... )
#endif
struct tun_struct {
struct list_head list;
unsigned long flags;
int attached;
uid_t owner;
gid_t group;
wait_queue_head_t read_wait;
struct sk_buff_head readq;
struct net_device *dev;
struct fasync_struct *fasync;
unsigned long if_flags;
u8 dev_addr[ETH_ALEN];
u32 chr_filter[2];
u32 net_filter[2];
#ifdef TUN_DEBUG
int debug;
#endif
};
/* Network device part of the driver */
static unsigned int tun_net_id;
struct tun_net {
struct list_head dev_list;
};
static const struct ethtool_ops tun_ethtool_ops;
/* 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 */
if (!tun->attached)
goto drop;
/* Packet dropping */
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. */
dev->stats.tx_fifo_errors++;
} else {
/* Single queue mode.
* Driver handles dropping of all packets itself. */
goto drop;
}
}
/* Queue packet */
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);
wake_up_interruptible(&tun->read_wait);
return 0;
drop:
dev->stats.tx_dropped++;
kfree_skb(skb);
return 0;
}
/** Add the specified Ethernet address to this multicast filter. */
static void
add_multi(u32* filter, const u8* addr)
{
int bit_nr = ether_crc(ETH_ALEN, addr) >> 26;
filter[bit_nr >> 5] |= 1 << (bit_nr & 31);
}
/** Remove the specified Ethernet addres from this multicast filter. */
static void
del_multi(u32* filter, const u8* addr)
{
int bit_nr = ether_crc(ETH_ALEN, addr) >> 26;
filter[bit_nr >> 5] &= ~(1 << (bit_nr & 31));
}
/** Update the list of multicast groups to which the network device belongs.
* This list is used to filter packets being sent from the character device to
* the network device. */
static void
tun_net_mclist(struct net_device *dev)
{
struct tun_struct *tun = netdev_priv(dev);
const struct dev_mc_list *mclist;
int i;
DECLARE_MAC_BUF(mac);
DBG(KERN_DEBUG "%s: tun_net_mclist: mc_count %d\n",
dev->name, dev->mc_count);
memset(tun->chr_filter, 0, sizeof tun->chr_filter);
for (i = 0, mclist = dev->mc_list; i < dev->mc_count && mclist != NULL;
i++, mclist = mclist->next) {
add_multi(tun->net_filter, mclist->dmi_addr);
DBG(KERN_DEBUG "%s: tun_net_mclist: %s\n",
dev->name, print_mac(mac, mclist->dmi_addr));
}
}
#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;
}
/* Initialize net device. */
static void tun_net_init(struct net_device *dev)
{
struct tun_struct *tun = netdev_priv(dev);
switch (tun->flags & TUN_TYPE_MASK) {
case TUN_TUN_DEV:
/* Point-to-Point TUN Device */
dev->hard_header_len = 0;
dev->addr_len = 0;
dev->mtu = 1500;
dev->change_mtu = tun_net_change_mtu;
/* Zero header length */
dev->type = ARPHRD_NONE;
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:
/* Ethernet TAP Device */
dev->set_multicast_list = tun_net_mclist;
ether_setup(dev);
dev->change_mtu = tun_net_change_mtu;
/* random address already created for us by tun_set_iff, use it */
memcpy(dev->dev_addr, tun->dev_addr, min(sizeof(tun->dev_addr), sizeof(dev->dev_addr)) );
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)
{
struct tun_struct *tun = file->private_data;
unsigned int mask = POLLOUT | POLLWRNORM;
if (!tun)
return -EBADFD;
DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name);
poll_wait(file, &tun->read_wait, wait);
if (!skb_queue_empty(&tun->readq))
mask |= POLLIN | POLLRDNORM;
return mask;
}
/* Get packet from user space buffer */
static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, size_t count)
{
struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) };
struct sk_buff *skb;
size_t len = count, align = 0;
if (!(tun->flags & TUN_NO_PI)) {
if ((len -= sizeof(pi)) > count)
return -EINVAL;
if(memcpy_fromiovec((void *)&pi, iv, sizeof(pi)))
return -EFAULT;
}
if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
align = NET_IP_ALIGN;
if (unlikely(len < ETH_HLEN))
return -EINVAL;
}
if (!(skb = alloc_skb(len + align, GFP_KERNEL))) {
tun->dev->stats.rx_dropped++;
return -ENOMEM;
}
if (align)
skb_reserve(skb, align);
if (memcpy_fromiovec(skb_put(skb, len), iv, len)) {
tun->dev->stats.rx_dropped++;
kfree_skb(skb);
return -EFAULT;
}
switch (tun->flags & TUN_TYPE_MASK) {
case TUN_TUN_DEV:
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;
}
}
skb_reset_mac_header(skb);
skb->protocol = pi.proto;
skb->dev = tun->dev;
break;
case TUN_TAP_DEV:
skb->protocol = eth_type_trans(skb, tun->dev);
break;
};
if (tun->flags & TUN_NOCHECKSUM)
skb->ip_summed = CHECKSUM_UNNECESSARY;
netif_rx_ni(skb);
tun->dev->last_rx = jiffies;
tun->dev->stats.rx_packets++;
tun->dev->stats.rx_bytes += len;
return count;
}
static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
unsigned long count, loff_t pos)
{
struct tun_struct *tun = iocb->ki_filp->private_data;
if (!tun)
return -EBADFD;
DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);
return tun_get_user(tun, (struct iovec *) iv, iov_length(iv, count));
}
/* Put packet to the user space buffer */
static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
struct sk_buff *skb,
struct iovec *iv, int len)
{
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;
}
if (memcpy_toiovec(iv, (void *) &pi, sizeof(pi)))
return -EFAULT;
total += sizeof(pi);
}
len = min_t(int, skb->len, len);
skb_copy_datagram_iovec(skb, 0, iv, len);
total += len;
tun->dev->stats.tx_packets++;
tun->dev->stats.tx_bytes += len;
return total;
}
static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
unsigned long count, loff_t pos)
{
struct file *file = iocb->ki_filp;
struct tun_struct *tun = file->private_data;
DECLARE_WAITQUEUE(wait, current);
struct sk_buff *skb;
ssize_t len, ret = 0;
DECLARE_MAC_BUF(mac);
if (!tun)
return -EBADFD;
DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
len = iov_length(iv, count);
if (len < 0)
return -EINVAL;
add_wait_queue(&tun->read_wait, &wait);
while (len) {
const u8 ones[ ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
u8 addr[ ETH_ALEN];
int bit_nr;
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;
}
/* Nothing to read, let's sleep */
schedule();
continue;
}
netif_wake_queue(tun->dev);
/** Decide whether to accept this packet. This code is designed to
* behave identically to an Ethernet interface. Accept the packet if
* - we are promiscuous.
* - the packet is addressed to us.
* - the packet is broadcast.
* - the packet is multicast and
* - we are multicast promiscous.
* - we belong to the multicast group.
*/
skb_copy_from_linear_data(skb, addr, min_t(size_t, sizeof addr,
skb->len));
bit_nr = ether_crc(sizeof addr, addr) >> 26;
if ((tun->if_flags & IFF_PROMISC) ||
memcmp(addr, tun->dev_addr, sizeof addr) == 0 ||
memcmp(addr, ones, sizeof addr) == 0 ||
(((addr[0] == 1 && addr[1] == 0 && addr[2] == 0x5e) ||
(addr[0] == 0x33 && addr[1] == 0x33)) &&
((tun->if_flags & IFF_ALLMULTI) ||
(tun->chr_filter[bit_nr >> 5] & (1 << (bit_nr & 31)))))) {
DBG(KERN_DEBUG "%s: tun_chr_readv: accepted: %s\n",
tun->dev->name, print_mac(mac, addr));
ret = tun_put_user(tun, skb, (struct iovec *) iv, len);
kfree_skb(skb);
break;
} else {
DBG(KERN_DEBUG "%s: tun_chr_readv: rejected: %s\n",
tun->dev->name, print_mac(mac, addr));
kfree_skb(skb);
continue;
}
}
current->state = TASK_RUNNING;
remove_wait_queue(&tun->read_wait, &wait);
return ret;
}
static void tun_setup(struct net_device *dev)
{
struct tun_struct *tun = netdev_priv(dev);
skb_queue_head_init(&tun->readq);
init_waitqueue_head(&tun->read_wait);
tun->owner = -1;
tun->group = -1;
dev->open = tun_net_open;
dev->hard_start_xmit = tun_net_xmit;
dev->stop = tun_net_close;
dev->ethtool_ops = &tun_ethtool_ops;
dev->destructor = free_netdev;
dev->features |= NETIF_F_NETNS_LOCAL;
}
static struct tun_struct *tun_get_by_name(struct tun_net *tn, const char *name)
{
struct tun_struct *tun;
ASSERT_RTNL();
list_for_each_entry(tun, &tn->dev_list, list) {
if (!strncmp(tun->dev->name, name, IFNAMSIZ))
return tun;
}
return NULL;
}
static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
{
struct tun_net *tn;
struct tun_struct *tun;
struct net_device *dev;
int err;
tn = net_generic(net, tun_net_id);
tun = tun_get_by_name(tn, ifr->ifr_name);
if (tun) {
if (tun->attached)
return -EBUSY;
/* Check permissions */
if (((tun->owner != -1 &&
current->euid != tun->owner) ||
(tun->group != -1 &&
current->egid != tun->group)) &&
!capable(CAP_NET_ADMIN))
return -EPERM;
}
else if (__dev_get_by_name(net, ifr->ifr_name))
return -EINVAL;
else {
char *name;
unsigned long flags = 0;
err = -EINVAL;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
/* 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";
} else
goto failed;
if (*ifr->ifr_name)
name = ifr->ifr_name;
dev = alloc_netdev(sizeof(struct tun_struct), name,
tun_setup);
if (!dev)
return -ENOMEM;
dev_net_set(dev, net);
tun = netdev_priv(dev);
tun->dev = dev;
tun->flags = flags;
/* Be promiscuous by default to maintain previous behaviour. */
tun->if_flags = IFF_PROMISC;
/* Generate random Ethernet address. */
*(__be16 *)tun->dev_addr = htons(0x00FF);
get_random_bytes(tun->dev_addr + sizeof(u16), 4);
memset(tun->chr_filter, 0, sizeof tun->chr_filter);
tun_net_init(dev);
if (strchr(dev->name, '%')) {
err = dev_alloc_name(dev, dev->name);
if (err < 0)
goto err_free_dev;
}
err = register_netdevice(tun->dev);
if (err < 0)
goto err_free_dev;
list_add(&tun->list, &tn->dev_list);
}
DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);
if (ifr->ifr_flags & IFF_NO_PI)
tun->flags |= TUN_NO_PI;
else
tun->flags &= ~TUN_NO_PI;
if (ifr->ifr_flags & IFF_ONE_QUEUE)
tun->flags |= TUN_ONE_QUEUE;
else
tun->flags &= ~TUN_ONE_QUEUE;
file->private_data = tun;
tun->attached = 1;
get_net(dev_net(tun->dev));
strcpy(ifr->ifr_name, tun->dev->name);
return 0;
err_free_dev:
free_netdev(dev);
failed:
return err;
}
static int tun_chr_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
struct tun_struct *tun = file->private_data;
void __user* argp = (void __user*)arg;
struct ifreq ifr;
DECLARE_MAC_BUF(mac);
if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
if (copy_from_user(&ifr, argp, sizeof ifr))
return -EFAULT;
if (cmd == TUNSETIFF && !tun) {
int err;
ifr.ifr_name[IFNAMSIZ-1] = '\0';
rtnl_lock();
err = tun_set_iff(current->nsproxy->net_ns, file, &ifr);
rtnl_unlock();
if (err)
return err;
if (copy_to_user(argp, &ifr, sizeof(ifr)))
return -EFAULT;
return 0;
}
if (!tun)
return -EBADFD;
DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd);
switch (cmd) {
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",
tun->dev->name, arg ? "enabled" : "disabled");
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;
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;
case TUNSETLINK:
{
int ret;
/* Only allow setting the type when the interface is down */
rtnl_lock();
if (tun->dev->flags & IFF_UP) {
DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
tun->dev->name);
ret = -EBUSY;
} else {
tun->dev->type = (int) arg;
DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
ret = 0;
}
rtnl_unlock();
return ret;
}
#ifdef TUN_DEBUG
case TUNSETDEBUG:
tun->debug = arg;
break;
#endif
case SIOCGIFFLAGS:
ifr.ifr_flags = tun->if_flags;
if (copy_to_user( argp, &ifr, sizeof ifr))
return -EFAULT;
return 0;
case SIOCSIFFLAGS:
/** Set the character device's interface flags. Currently only
* IFF_PROMISC and IFF_ALLMULTI are used. */
tun->if_flags = ifr.ifr_flags;
DBG(KERN_INFO "%s: interface flags 0x%lx\n",
tun->dev->name, tun->if_flags);
return 0;
case SIOCGIFHWADDR:
/* Note: the actual net device's address may be different */
memcpy(ifr.ifr_hwaddr.sa_data, tun->dev_addr,
min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr));
if (copy_to_user( argp, &ifr, sizeof ifr))
return -EFAULT;
return 0;
case SIOCSIFHWADDR:
{
/* try to set the actual net device's hw address */
int ret;
rtnl_lock();
ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
rtnl_unlock();
if (ret == 0) {
/** Set the character device's hardware address. This is used when
* filtering packets being sent from the network device to the character
* device. */
memcpy(tun->dev_addr, ifr.ifr_hwaddr.sa_data,
min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr));
DBG(KERN_DEBUG "%s: set hardware address: %x:%x:%x:%x:%x:%x\n",
tun->dev->name,
tun->dev_addr[0], tun->dev_addr[1], tun->dev_addr[2],
tun->dev_addr[3], tun->dev_addr[4], tun->dev_addr[5]);
}
return ret;
}
case SIOCADDMULTI:
/** Add the specified group to the character device's multicast filter
* list. */
rtnl_lock();
netif_tx_lock_bh(tun->dev);
add_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data);
netif_tx_unlock_bh(tun->dev);
rtnl_unlock();
DBG(KERN_DEBUG "%s: add multi: %s\n",
tun->dev->name, print_mac(mac, ifr.ifr_hwaddr.sa_data));
return 0;
case SIOCDELMULTI:
/** Remove the specified group from the character device's multicast
* filter list. */
rtnl_lock();
netif_tx_lock_bh(tun->dev);
del_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data);
netif_tx_unlock_bh(tun->dev);
rtnl_unlock();
DBG(KERN_DEBUG "%s: del multi: %s\n",
tun->dev->name, print_mac(mac, ifr.ifr_hwaddr.sa_data));
return 0;
default:
return -EINVAL;
};
return 0;
}
static int tun_chr_fasync(int fd, struct file *file, int on)
{
struct tun_struct *tun = file->private_data;
int ret;
if (!tun)
return -EBADFD;
DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);
if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
return ret;
if (on) {
ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
if (ret)
return ret;
tun->flags |= TUN_FASYNC;
} else
tun->flags &= ~TUN_FASYNC;
return 0;
}
static int tun_chr_open(struct inode *inode, struct file * file)
{
DBG1(KERN_INFO "tunX: tun_chr_open\n");
file->private_data = NULL;
return 0;
}
static int tun_chr_close(struct inode *inode, struct file *file)
{
struct tun_struct *tun = file->private_data;
if (!tun)
return 0;
DBG(KERN_INFO "%s: tun_chr_close\n", tun->dev->name);
tun_chr_fasync(-1, file, 0);
rtnl_lock();
/* Detach from net device */
file->private_data = NULL;
tun->attached = 0;
put_net(dev_net(tun->dev));
/* Drop read queue */
skb_queue_purge(&tun->readq);
if (!(tun->flags & TUN_PERSIST)) {
list_del(&tun->list);
unregister_netdevice(tun->dev);
}
rtnl_unlock();
return 0;
}
static const struct file_operations tun_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.read = do_sync_read,
.aio_read = tun_chr_aio_read,
.write = do_sync_write,
.aio_write = tun_chr_aio_write,
.poll = tun_chr_poll,
.ioctl = tun_chr_ioctl,
.open = tun_chr_open,
.release = tun_chr_close,
.fasync = tun_chr_fasync
};
static struct miscdevice tun_miscdev = {
.minor = TUN_MINOR,
.name = "tun",
.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);
return tun->attached;
}
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;
}
static const struct ethtool_ops tun_ethtool_ops = {
.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
};
static int tun_init_net(struct net *net)
{
struct tun_net *tn;
tn = kmalloc(sizeof(*tn), GFP_KERNEL);
if (tn == NULL)
return -ENOMEM;
INIT_LIST_HEAD(&tn->dev_list);
if (net_assign_generic(net, tun_net_id, tn)) {
kfree(tn);
return -ENOMEM;
}
return 0;
}
static void tun_exit_net(struct net *net)
{
struct tun_net *tn;
struct tun_struct *tun, *nxt;
tn = net_generic(net, tun_net_id);
rtnl_lock();
list_for_each_entry_safe(tun, nxt, &tn->dev_list, list) {
DBG(KERN_INFO "%s cleaned up\n", tun->dev->name);
unregister_netdevice(tun->dev);
}
rtnl_unlock();
kfree(tn);
}
static struct pernet_operations tun_net_ops = {
.init = tun_init_net,
.exit = tun_exit_net,
};
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);
ret = register_pernet_gen_device(&tun_net_id, &tun_net_ops);
if (ret) {
printk(KERN_ERR "tun: Can't register pernet ops\n");
goto err_pernet;
}
ret = misc_register(&tun_miscdev);
if (ret) {
printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
goto err_misc;
}
return 0;
err_misc:
unregister_pernet_gen_device(tun_net_id, &tun_net_ops);
err_pernet:
return ret;
}
static void tun_cleanup(void)
{
misc_deregister(&tun_miscdev);
unregister_pernet_gen_device(tun_net_id, &tun_net_ops);
}
module_init(tun_init);
module_exit(tun_cleanup);
MODULE_DESCRIPTION(DRV_DESCRIPTION);
MODULE_AUTHOR(DRV_COPYRIGHT);
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(TUN_MINOR);