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alistair23-linux/drivers/net/tun.c
Linus Torvalds 437589a74b Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 
Pull user namespace changes from Eric Biederman:
 "This is a mostly modest set of changes to enable basic user namespace
  support.  This allows the code to code to compile with user namespaces
  enabled and removes the assumption there is only the initial user
  namespace.  Everything is converted except for the most complex of the
  filesystems: autofs4, 9p, afs, ceph, cifs, coda, fuse, gfs2, ncpfs,
  nfs, ocfs2 and xfs as those patches need a bit more review.

  The strategy is to push kuid_t and kgid_t values are far down into
  subsystems and filesystems as reasonable.  Leaving the make_kuid and
  from_kuid operations to happen at the edge of userspace, as the values
  come off the disk, and as the values come in from the network.
  Letting compile type incompatible compile errors (present when user
  namespaces are enabled) guide me to find the issues.

  The most tricky areas have been the places where we had an implicit
  union of uid and gid values and were storing them in an unsigned int.
  Those places were converted into explicit unions.  I made certain to
  handle those places with simple trivial patches.

  Out of that work I discovered we have generic interfaces for storing
  quota by projid.  I had never heard of the project identifiers before.
  Adding full user namespace support for project identifiers accounts
  for most of the code size growth in my git tree.

  Ultimately there will be work to relax privlige checks from
  "capable(FOO)" to "ns_capable(user_ns, FOO)" where it is safe allowing
  root in a user names to do those things that today we only forbid to
  non-root users because it will confuse suid root applications.

  While I was pushing kuid_t and kgid_t changes deep into the audit code
  I made a few other cleanups.  I capitalized on the fact we process
  netlink messages in the context of the message sender.  I removed
  usage of NETLINK_CRED, and started directly using current->tty.

  Some of these patches have also made it into maintainer trees, with no
  problems from identical code from different trees showing up in
  linux-next.

  After reading through all of this code I feel like I might be able to
  win a game of kernel trivial pursuit."

Fix up some fairly trivial conflicts in netfilter uid/git logging code.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (107 commits)
  userns: Convert the ufs filesystem to use kuid/kgid where appropriate
  userns: Convert the udf filesystem to use kuid/kgid where appropriate
  userns: Convert ubifs to use kuid/kgid
  userns: Convert squashfs to use kuid/kgid where appropriate
  userns: Convert reiserfs to use kuid and kgid where appropriate
  userns: Convert jfs to use kuid/kgid where appropriate
  userns: Convert jffs2 to use kuid and kgid where appropriate
  userns: Convert hpfs to use kuid and kgid where appropriate
  userns: Convert btrfs to use kuid/kgid where appropriate
  userns: Convert bfs to use kuid/kgid where appropriate
  userns: Convert affs to use kuid/kgid wherwe appropriate
  userns: On alpha modify linux_to_osf_stat to use convert from kuids and kgids
  userns: On ia64 deal with current_uid and current_gid being kuid and kgid
  userns: On ppc convert current_uid from a kuid before printing.
  userns: Convert s390 getting uid and gid system calls to use kuid and kgid
  userns: Convert s390 hypfs to use kuid and kgid where appropriate
  userns: Convert binder ipc to use kuids
  userns: Teach security_path_chown to take kuids and kgids
  userns: Add user namespace support to IMA
  userns: Convert EVM to deal with kuids and kgids in it's hmac computation
  ...
2012-10-02 11:11:09 -07:00

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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:
*
* Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14
* Add TUNSETLINK ioctl to set the link encapsulation
*
* Mark Smith <markzzzsmith@yahoo.com.au>
* Use eth_random_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 pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#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/compat.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 <linux/virtio_net.h>
#include <linux/rcupdate.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>
#include <net/rtnetlink.h>
#include <net/sock.h>
#include <net/cls_cgroup.h>
#include <asm/uaccess.h>
/* Uncomment to enable debugging */
/* #define TUN_DEBUG 1 */
#ifdef TUN_DEBUG
static int debug;
#define tun_debug(level, tun, fmt, args...) \
do { \
if (tun->debug) \
netdev_printk(level, tun->dev, fmt, ##args); \
} while (0)
#define DBG1(level, fmt, args...) \
do { \
if (debug == 2) \
printk(level fmt, ##args); \
} while (0)
#else
#define tun_debug(level, tun, fmt, args...) \
do { \
if (0) \
netdev_printk(level, tun->dev, fmt, ##args); \
} while (0)
#define DBG1(level, fmt, args...) \
do { \
if (0) \
printk(level fmt, ##args); \
} while (0)
#endif
#define GOODCOPY_LEN 128
#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];
};
struct tun_file {
atomic_t count;
struct tun_struct *tun;
struct net *net;
};
struct tun_sock;
struct tun_struct {
struct tun_file *tfile;
unsigned int flags;
kuid_t owner;
kgid_t group;
struct net_device *dev;
netdev_features_t set_features;
#define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \
NETIF_F_TSO6|NETIF_F_UFO)
struct fasync_struct *fasync;
struct tap_filter txflt;
struct socket socket;
struct socket_wq wq;
int vnet_hdr_sz;
#ifdef TUN_DEBUG
int debug;
#endif
};
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);
}
static int tun_attach(struct tun_struct *tun, struct file *file)
{
struct tun_file *tfile = file->private_data;
int err;
ASSERT_RTNL();
netif_tx_lock_bh(tun->dev);
err = -EINVAL;
if (tfile->tun)
goto out;
err = -EBUSY;
if (tun->tfile)
goto out;
err = 0;
tfile->tun = tun;
tun->tfile = tfile;
tun->socket.file = file;
netif_carrier_on(tun->dev);
dev_hold(tun->dev);
sock_hold(tun->socket.sk);
atomic_inc(&tfile->count);
out:
netif_tx_unlock_bh(tun->dev);
return err;
}
static void __tun_detach(struct tun_struct *tun)
{
/* Detach from net device */
netif_tx_lock_bh(tun->dev);
netif_carrier_off(tun->dev);
tun->tfile = NULL;
netif_tx_unlock_bh(tun->dev);
/* Drop read queue */
skb_queue_purge(&tun->socket.sk->sk_receive_queue);
/* 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();
}
static struct tun_struct *__tun_get(struct tun_file *tfile)
{
struct tun_struct *tun = NULL;
if (atomic_inc_not_zero(&tfile->count))
tun = tfile->tun;
return tun;
}
static struct tun_struct *tun_get(struct file *file)
{
return __tun_get(file->private_data);
}
static void tun_put(struct tun_struct *tun)
{
struct tun_file *tfile = tun->tfile;
if (atomic_dec_and_test(&tfile->count))
tun_detach(tfile->tun);
}
/* TAP filtering */
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;
/* Remaining multicast addresses are hashed,
* unicast will leave the filter disabled. */
memset(filter->mask, 0, sizeof(filter->mask));
for (; n < uf.count; n++) {
if (!is_multicast_ether_addr(addr[n].u)) {
err = 0; /* no filter */
goto done;
}
addr_hash_set(filter->mask, addr[n].u);
}
/* 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 (ether_addr_equal(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);
}
/* Network device part of the driver */
static const struct ethtool_ops tun_ethtool_ops;
/* 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) {
wake_up_all(&tun->wq.wait);
if (atomic_dec_and_test(&tfile->count))
__tun_detach(tun);
}
}
static void tun_free_netdev(struct net_device *dev)
{
struct tun_struct *tun = netdev_priv(dev);
BUG_ON(!test_bit(SOCK_EXTERNALLY_ALLOCATED, &tun->socket.flags));
sk_release_kernel(tun->socket.sk);
}
/* 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 netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct tun_struct *tun = netdev_priv(dev);
tun_debug(KERN_INFO, tun, "tun_net_xmit %d\n", skb->len);
/* Drop packet if interface is not attached */
if (!tun->tfile)
goto drop;
/* 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;
if (tun->socket.sk->sk_filter &&
sk_filter(tun->socket.sk, skb))
goto drop;
if (skb_queue_len(&tun->socket.sk->sk_receive_queue) >= 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;
}
}
/* Orphan the skb - required as we might hang on to it
* for indefinite time. */
if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
goto drop;
skb_orphan(skb);
/* Enqueue packet */
skb_queue_tail(&tun->socket.sk->sk_receive_queue, skb);
/* Notify and wake up reader process */
if (tun->flags & TUN_FASYNC)
kill_fasync(&tun->fasync, SIGIO, POLL_IN);
wake_up_interruptible_poll(&tun->wq.wait, POLLIN |
POLLRDNORM | POLLRDBAND);
return NETDEV_TX_OK;
drop:
dev->stats.tx_dropped++;
kfree_skb(skb);
return NETDEV_TX_OK;
}
static void tun_net_mclist(struct net_device *dev)
{
/*
* 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.
*/
}
#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;
}
static netdev_features_t tun_net_fix_features(struct net_device *dev,
netdev_features_t features)
{
struct tun_struct *tun = netdev_priv(dev);
return (features & tun->set_features) | (features & ~TUN_USER_FEATURES);
}
#ifdef CONFIG_NET_POLL_CONTROLLER
static void tun_poll_controller(struct net_device *dev)
{
/*
* Tun only receives frames when:
* 1) the char device endpoint gets data from user space
* 2) the tun socket gets a sendmsg call from user space
* Since both of those are syncronous operations, we are guaranteed
* never to have pending data when we poll for it
* so theres nothing to do here but return.
* We need this though so netpoll recognizes us as an interface that
* supports polling, which enables bridge devices in virt setups to
* still use netconsole
*/
return;
}
#endif
static const struct net_device_ops tun_netdev_ops = {
.ndo_uninit = tun_net_uninit,
.ndo_open = tun_net_open,
.ndo_stop = tun_net_close,
.ndo_start_xmit = tun_net_xmit,
.ndo_change_mtu = tun_net_change_mtu,
.ndo_fix_features = tun_net_fix_features,
#ifdef CONFIG_NET_POLL_CONTROLLER
.ndo_poll_controller = tun_poll_controller,
#endif
};
static const struct net_device_ops tap_netdev_ops = {
.ndo_uninit = tun_net_uninit,
.ndo_open = tun_net_open,
.ndo_stop = tun_net_close,
.ndo_start_xmit = tun_net_xmit,
.ndo_change_mtu = tun_net_change_mtu,
.ndo_fix_features = tun_net_fix_features,
.ndo_set_rx_mode = tun_net_mclist,
.ndo_set_mac_address = eth_mac_addr,
.ndo_validate_addr = eth_validate_addr,
#ifdef CONFIG_NET_POLL_CONTROLLER
.ndo_poll_controller = tun_poll_controller,
#endif
};
/* 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:
dev->netdev_ops = &tun_netdev_ops;
/* Point-to-Point TUN Device */
dev->hard_header_len = 0;
dev->addr_len = 0;
dev->mtu = 1500;
/* 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:
dev->netdev_ops = &tap_netdev_ops;
/* Ethernet TAP Device */
ether_setup(dev);
dev->priv_flags &= ~IFF_TX_SKB_SHARING;
eth_hw_addr_random(dev);
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_file *tfile = file->private_data;
struct tun_struct *tun = __tun_get(tfile);
struct sock *sk;
unsigned int mask = 0;
if (!tun)
return POLLERR;
sk = tun->socket.sk;
tun_debug(KERN_INFO, tun, "tun_chr_poll\n");
poll_wait(file, &tun->wq.wait, wait);
if (!skb_queue_empty(&sk->sk_receive_queue))
mask |= POLLIN | POLLRDNORM;
if (sock_writeable(sk) ||
(!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
sock_writeable(sk)))
mask |= POLLOUT | POLLWRNORM;
if (tun->dev->reg_state != NETREG_REGISTERED)
mask = POLLERR;
tun_put(tun);
return mask;
}
/* 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). */
static struct sk_buff *tun_alloc_skb(struct tun_struct *tun,
size_t prepad, size_t len,
size_t linear, int noblock)
{
struct sock *sk = tun->socket.sk;
struct sk_buff *skb;
int err;
sock_update_classid(sk);
/* Under a page? Don't bother with paged skb. */
if (prepad + len < PAGE_SIZE || !linear)
linear = len;
skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
&err);
if (!skb)
return ERR_PTR(err);
skb_reserve(skb, prepad);
skb_put(skb, linear);
skb->data_len = len - linear;
skb->len += len - linear;
return skb;
}
/* set skb frags from iovec, this can move to core network code for reuse */
static int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *from,
int offset, size_t count)
{
int len = iov_length(from, count) - offset;
int copy = skb_headlen(skb);
int size, offset1 = 0;
int i = 0;
/* Skip over from offset */
while (count && (offset >= from->iov_len)) {
offset -= from->iov_len;
++from;
--count;
}
/* copy up to skb headlen */
while (count && (copy > 0)) {
size = min_t(unsigned int, copy, from->iov_len - offset);
if (copy_from_user(skb->data + offset1, from->iov_base + offset,
size))
return -EFAULT;
if (copy > size) {
++from;
--count;
offset = 0;
} else
offset += size;
copy -= size;
offset1 += size;
}
if (len == offset1)
return 0;
while (count--) {
struct page *page[MAX_SKB_FRAGS];
int num_pages;
unsigned long base;
unsigned long truesize;
len = from->iov_len - offset;
if (!len) {
offset = 0;
++from;
continue;
}
base = (unsigned long)from->iov_base + offset;
size = ((base & ~PAGE_MASK) + len + ~PAGE_MASK) >> PAGE_SHIFT;
if (i + size > MAX_SKB_FRAGS)
return -EMSGSIZE;
num_pages = get_user_pages_fast(base, size, 0, &page[i]);
if (num_pages != size) {
for (i = 0; i < num_pages; i++)
put_page(page[i]);
return -EFAULT;
}
truesize = size * PAGE_SIZE;
skb->data_len += len;
skb->len += len;
skb->truesize += truesize;
atomic_add(truesize, &skb->sk->sk_wmem_alloc);
while (len) {
int off = base & ~PAGE_MASK;
int size = min_t(int, len, PAGE_SIZE - off);
__skb_fill_page_desc(skb, i, page[i], off, size);
skb_shinfo(skb)->nr_frags++;
/* increase sk_wmem_alloc */
base += size;
len -= size;
i++;
}
offset = 0;
++from;
}
return 0;
}
/* Get packet from user space buffer */
static ssize_t tun_get_user(struct tun_struct *tun, void *msg_control,
const struct iovec *iv, size_t total_len,
size_t count, int noblock)
{
struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
struct sk_buff *skb;
size_t len = total_len, align = NET_SKB_PAD;
struct virtio_net_hdr gso = { 0 };
int offset = 0;
int copylen;
bool zerocopy = false;
int err;
if (!(tun->flags & TUN_NO_PI)) {
if ((len -= sizeof(pi)) > total_len)
return -EINVAL;
if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
return -EFAULT;
offset += sizeof(pi);
}
if (tun->flags & TUN_VNET_HDR) {
if ((len -= tun->vnet_hdr_sz) > total_len)
return -EINVAL;
if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
return -EFAULT;
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;
if (gso.hdr_len > len)
return -EINVAL;
offset += tun->vnet_hdr_sz;
}
if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
align += NET_IP_ALIGN;
if (unlikely(len < ETH_HLEN ||
(gso.hdr_len && gso.hdr_len < ETH_HLEN)))
return -EINVAL;
}
if (msg_control)
zerocopy = true;
if (zerocopy) {
/* Userspace may produce vectors with count greater than
* MAX_SKB_FRAGS, so we need to linearize parts of the skb
* to let the rest of data to be fit in the frags.
*/
if (count > MAX_SKB_FRAGS) {
copylen = iov_length(iv, count - MAX_SKB_FRAGS);
if (copylen < offset)
copylen = 0;
else
copylen -= offset;
} else
copylen = 0;
/* There are 256 bytes to be copied in skb, so there is enough
* room for skb expand head in case it is used.
* The rest of the buffer is mapped from userspace.
*/
if (copylen < gso.hdr_len)
copylen = gso.hdr_len;
if (!copylen)
copylen = GOODCOPY_LEN;
} else
copylen = len;
skb = tun_alloc_skb(tun, align, copylen, gso.hdr_len, noblock);
if (IS_ERR(skb)) {
if (PTR_ERR(skb) != -EAGAIN)
tun->dev->stats.rx_dropped++;
return PTR_ERR(skb);
}
if (zerocopy)
err = zerocopy_sg_from_iovec(skb, iv, offset, count);
else
err = skb_copy_datagram_from_iovec(skb, 0, iv, offset, len);
if (err) {
tun->dev->stats.rx_dropped++;
kfree_skb(skb);
return -EFAULT;
}
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;
}
}
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 (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;
case VIRTIO_NET_HDR_GSO_UDP:
skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
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;
}
/* copy skb_ubuf_info for callback when skb has no error */
if (zerocopy) {
skb_shinfo(skb)->destructor_arg = msg_control;
skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
}
netif_rx_ni(skb);
tun->dev->stats.rx_packets++;
tun->dev->stats.rx_bytes += len;
return total_len;
}
static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
unsigned long count, loff_t pos)
{
struct file *file = iocb->ki_filp;
struct tun_struct *tun = tun_get(file);
ssize_t result;
if (!tun)
return -EBADFD;
tun_debug(KERN_INFO, tun, "tun_chr_write %ld\n", count);
result = tun_get_user(tun, NULL, iv, iov_length(iv, count), count,
file->f_flags & O_NONBLOCK);
tun_put(tun);
return result;
}
/* Put packet to the user space buffer */
static ssize_t tun_put_user(struct tun_struct *tun,
struct sk_buff *skb,
const 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_toiovecend(iv, (void *) &pi, 0, sizeof(pi)))
return -EFAULT;
total += sizeof(pi);
}
if (tun->flags & TUN_VNET_HDR) {
struct virtio_net_hdr gso = { 0 }; /* no info leak */
if ((len -= tun->vnet_hdr_sz) < 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 if (sinfo->gso_type & SKB_GSO_UDP)
gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
else {
pr_err("unexpected GSO type: "
"0x%x, gso_size %d, hdr_len %d\n",
sinfo->gso_type, gso.gso_size,
gso.hdr_len);
print_hex_dump(KERN_ERR, "tun: ",
DUMP_PREFIX_NONE,
16, 1, skb->head,
min((int)gso.hdr_len, 64), true);
WARN_ON_ONCE(1);
return -EINVAL;
}
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_checksum_start_offset(skb);
gso.csum_offset = skb->csum_offset;
} else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
gso.flags = VIRTIO_NET_HDR_F_DATA_VALID;
} /* else everything is zero */
if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
sizeof(gso))))
return -EFAULT;
total += tun->vnet_hdr_sz;
}
len = min_t(int, skb->len, len);
skb_copy_datagram_const_iovec(skb, 0, iv, total, len);
total += skb->len;
tun->dev->stats.tx_packets++;
tun->dev->stats.tx_bytes += len;
return total;
}
static ssize_t tun_do_read(struct tun_struct *tun,
struct kiocb *iocb, const struct iovec *iv,
ssize_t len, int noblock)
{
DECLARE_WAITQUEUE(wait, current);
struct sk_buff *skb;
ssize_t ret = 0;
tun_debug(KERN_INFO, tun, "tun_chr_read\n");
if (unlikely(!noblock))
add_wait_queue(&tun->wq.wait, &wait);
while (len) {
current->state = TASK_INTERRUPTIBLE;
/* Read frames from the queue */
if (!(skb=skb_dequeue(&tun->socket.sk->sk_receive_queue))) {
if (noblock) {
ret = -EAGAIN;
break;
}
if (signal_pending(current)) {
ret = -ERESTARTSYS;
break;
}
if (tun->dev->reg_state != NETREG_REGISTERED) {
ret = -EIO;
break;
}
/* Nothing to read, let's sleep */
schedule();
continue;
}
netif_wake_queue(tun->dev);
ret = tun_put_user(tun, skb, iv, len);
kfree_skb(skb);
break;
}
current->state = TASK_RUNNING;
if (unlikely(!noblock))
remove_wait_queue(&tun->wq.wait, &wait);
return ret;
}
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_file *tfile = file->private_data;
struct tun_struct *tun = __tun_get(tfile);
ssize_t len, ret;
if (!tun)
return -EBADFD;
len = iov_length(iv, count);
if (len < 0) {
ret = -EINVAL;
goto out;
}
ret = tun_do_read(tun, iocb, iv, len, file->f_flags & O_NONBLOCK);
ret = min_t(ssize_t, ret, len);
out:
tun_put(tun);
return ret;
}
static void tun_setup(struct net_device *dev)
{
struct tun_struct *tun = netdev_priv(dev);
tun->owner = INVALID_UID;
tun->group = INVALID_GID;
dev->ethtool_ops = &tun_ethtool_ops;
dev->destructor = tun_free_netdev;
}
/* 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,
};
static void tun_sock_write_space(struct sock *sk)
{
struct tun_struct *tun;
wait_queue_head_t *wqueue;
if (!sock_writeable(sk))
return;
if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
return;
wqueue = sk_sleep(sk);
if (wqueue && waitqueue_active(wqueue))
wake_up_interruptible_sync_poll(wqueue, POLLOUT |
POLLWRNORM | POLLWRBAND);
tun = tun_sk(sk)->tun;
kill_fasync(&tun->fasync, SIGIO, POLL_OUT);
}
static void tun_sock_destruct(struct sock *sk)
{
free_netdev(tun_sk(sk)->tun->dev);
}
static int tun_sendmsg(struct kiocb *iocb, struct socket *sock,
struct msghdr *m, size_t total_len)
{
struct tun_struct *tun = container_of(sock, struct tun_struct, socket);
return tun_get_user(tun, m->msg_control, m->msg_iov, total_len,
m->msg_iovlen, m->msg_flags & MSG_DONTWAIT);
}
static int tun_recvmsg(struct kiocb *iocb, struct socket *sock,
struct msghdr *m, size_t total_len,
int flags)
{
struct tun_struct *tun = container_of(sock, struct tun_struct, socket);
int ret;
if (flags & ~(MSG_DONTWAIT|MSG_TRUNC))
return -EINVAL;
ret = tun_do_read(tun, iocb, m->msg_iov, total_len,
flags & MSG_DONTWAIT);
if (ret > total_len) {
m->msg_flags |= MSG_TRUNC;
ret = flags & MSG_TRUNC ? ret : total_len;
}
return ret;
}
static int tun_release(struct socket *sock)
{
if (sock->sk)
sock_put(sock->sk);
return 0;
}
/* Ops structure to mimic raw sockets with tun */
static const struct proto_ops tun_socket_ops = {
.sendmsg = tun_sendmsg,
.recvmsg = tun_recvmsg,
.release = tun_release,
};
static struct proto tun_proto = {
.name = "tun",
.owner = THIS_MODULE,
.obj_size = sizeof(struct tun_sock),
};
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 uid_valid(tun->owner)?
sprintf(buf, "%u\n",
from_kuid_munged(current_user_ns(), tun->owner)):
sprintf(buf, "-1\n");
}
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 gid_valid(tun->group) ?
sprintf(buf, "%u\n",
from_kgid_munged(current_user_ns(), tun->group)):
sprintf(buf, "-1\n");
}
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);
static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
{
struct sock *sk;
struct tun_struct *tun;
struct net_device *dev;
int err;
dev = __dev_get_by_name(net, ifr->ifr_name);
if (dev) {
const struct cred *cred = current_cred();
if (ifr->ifr_flags & IFF_TUN_EXCL)
return -EBUSY;
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;
if (((uid_valid(tun->owner) && !uid_eq(cred->euid, tun->owner)) ||
(gid_valid(tun->group) && !in_egroup_p(tun->group))) &&
!capable(CAP_NET_ADMIN))
return -EPERM;
err = security_tun_dev_attach(tun->socket.sk);
if (err < 0)
return err;
err = tun_attach(tun, file);
if (err < 0)
return err;
}
else {
char *name;
unsigned long flags = 0;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
err = security_tun_dev_create();
if (err < 0)
return err;
/* 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
return -EINVAL;
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);
dev->rtnl_link_ops = &tun_link_ops;
tun = netdev_priv(dev);
tun->dev = dev;
tun->flags = flags;
tun->txflt.count = 0;
tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
set_bit(SOCK_EXTERNALLY_ALLOCATED, &tun->socket.flags);
err = -ENOMEM;
sk = sk_alloc(&init_net, AF_UNSPEC, GFP_KERNEL, &tun_proto);
if (!sk)
goto err_free_dev;
sk_change_net(sk, net);
tun->socket.wq = &tun->wq;
init_waitqueue_head(&tun->wq.wait);
tun->socket.ops = &tun_socket_ops;
sock_init_data(&tun->socket, sk);
sk->sk_write_space = tun_sock_write_space;
sk->sk_sndbuf = INT_MAX;
sock_set_flag(sk, SOCK_ZEROCOPY);
tun_sk(sk)->tun = tun;
security_tun_dev_post_create(sk);
tun_net_init(dev);
dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
TUN_USER_FEATURES;
dev->features = dev->hw_features;
err = register_netdevice(tun->dev);
if (err < 0)
goto err_free_sk;
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))
pr_err("Failed to create tun sysfs files\n");
sk->sk_destruct = tun_sock_destruct;
err = tun_attach(tun, file);
if (err < 0)
goto failed;
}
tun_debug(KERN_INFO, tun, "tun_set_iff\n");
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;
if (ifr->ifr_flags & IFF_VNET_HDR)
tun->flags |= TUN_VNET_HDR;
else
tun->flags &= ~TUN_VNET_HDR;
/* Make sure persistent devices do not get stuck in
* xoff state.
*/
if (netif_running(tun->dev))
netif_wake_queue(tun->dev);
strcpy(ifr->ifr_name, tun->dev->name);
return 0;
err_free_sk:
tun_free_netdev(dev);
err_free_dev:
free_netdev(dev);
failed:
return err;
}
static int tun_get_iff(struct net *net, struct tun_struct *tun,
struct ifreq *ifr)
{
tun_debug(KERN_INFO, tun, "tun_get_iff\n");
strcpy(ifr->ifr_name, tun->dev->name);
ifr->ifr_flags = tun_flags(tun);
return 0;
}
/* This is like a cut-down ethtool ops, except done via tun fd so no
* privs required. */
static int set_offload(struct tun_struct *tun, unsigned long arg)
{
netdev_features_t features = 0;
if (arg & TUN_F_CSUM) {
features |= NETIF_F_HW_CSUM;
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);
}
if (arg & TUN_F_UFO) {
features |= NETIF_F_UFO;
arg &= ~TUN_F_UFO;
}
}
/* This gives the user a way to test for new features in future by
* trying to set them. */
if (arg)
return -EINVAL;
tun->set_features = features;
netdev_update_features(tun->dev);
return 0;
}
static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
unsigned long arg, int ifreq_len)
{
struct tun_file *tfile = file->private_data;
struct tun_struct *tun;
void __user* argp = (void __user*)arg;
struct sock_fprog fprog;
struct ifreq ifr;
kuid_t owner;
kgid_t group;
int sndbuf;
int vnet_hdr_sz;
int ret;
if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89) {
if (copy_from_user(&ifr, argp, ifreq_len))
return -EFAULT;
} else {
memset(&ifr, 0, sizeof(ifr));
}
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);
}
rtnl_lock();
tun = __tun_get(tfile);
if (cmd == TUNSETIFF && !tun) {
ifr.ifr_name[IFNAMSIZ-1] = '\0';
ret = tun_set_iff(tfile->net, file, &ifr);
if (ret)
goto unlock;
if (copy_to_user(argp, &ifr, ifreq_len))
ret = -EFAULT;
goto unlock;
}
ret = -EBADFD;
if (!tun)
goto unlock;
tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %d\n", cmd);
ret = 0;
switch (cmd) {
case TUNGETIFF:
ret = tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
if (ret)
break;
if (copy_to_user(argp, &ifr, ifreq_len))
ret = -EFAULT;
break;
case TUNSETNOCSUM:
/* Disable/Enable checksum */
/* [unimplemented] */
tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n",
arg ? "disabled" : "enabled");
break;
case TUNSETPERSIST:
/* Disable/Enable persist mode */
if (arg)
tun->flags |= TUN_PERSIST;
else
tun->flags &= ~TUN_PERSIST;
tun_debug(KERN_INFO, tun, "persist %s\n",
arg ? "enabled" : "disabled");
break;
case TUNSETOWNER:
/* Set owner of the device */
owner = make_kuid(current_user_ns(), arg);
if (!uid_valid(owner)) {
ret = -EINVAL;
break;
}
tun->owner = owner;
tun_debug(KERN_INFO, tun, "owner set to %d\n",
from_kuid(&init_user_ns, tun->owner));
break;
case TUNSETGROUP:
/* Set group of the device */
group = make_kgid(current_user_ns(), arg);
if (!gid_valid(group)) {
ret = -EINVAL;
break;
}
tun->group = group;
tun_debug(KERN_INFO, tun, "group set to %d\n",
from_kgid(&init_user_ns, tun->group));
break;
case TUNSETLINK:
/* Only allow setting the type when the interface is down */
if (tun->dev->flags & IFF_UP) {
tun_debug(KERN_INFO, tun,
"Linktype set failed because interface is up\n");
ret = -EBUSY;
} else {
tun->dev->type = (int) arg;
tun_debug(KERN_INFO, tun, "linktype set to %d\n",
tun->dev->type);
ret = 0;
}
break;
#ifdef TUN_DEBUG
case TUNSETDEBUG:
tun->debug = arg;
break;
#endif
case TUNSETOFFLOAD:
ret = set_offload(tun, arg);
break;
case TUNSETTXFILTER:
/* Can be set only for TAPs */
ret = -EINVAL;
if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
break;
ret = update_filter(&tun->txflt, (void __user *)arg);
break;
case SIOCGIFHWADDR:
/* Get hw address */
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, ifreq_len))
ret = -EFAULT;
break;
case SIOCSIFHWADDR:
/* Set hw address */
tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n",
ifr.ifr_hwaddr.sa_data);
ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
break;
case TUNGETSNDBUF:
sndbuf = tun->socket.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->socket.sk->sk_sndbuf = sndbuf;
break;
case TUNGETVNETHDRSZ:
vnet_hdr_sz = tun->vnet_hdr_sz;
if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz)))
ret = -EFAULT;
break;
case TUNSETVNETHDRSZ:
if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) {
ret = -EFAULT;
break;
}
if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) {
ret = -EINVAL;
break;
}
tun->vnet_hdr_sz = vnet_hdr_sz;
break;
case TUNATTACHFILTER:
/* Can be set only for TAPs */
ret = -EINVAL;
if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
break;
ret = -EFAULT;
if (copy_from_user(&fprog, argp, sizeof(fprog)))
break;
ret = sk_attach_filter(&fprog, tun->socket.sk);
break;
case TUNDETACHFILTER:
/* Can be set only for TAPs */
ret = -EINVAL;
if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
break;
ret = sk_detach_filter(tun->socket.sk);
break;
default:
ret = -EINVAL;
break;
}
unlock:
rtnl_unlock();
if (tun)
tun_put(tun);
return ret;
}
static long tun_chr_ioctl(struct file *file,
unsigned int cmd, unsigned long arg)
{
return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
}
#ifdef CONFIG_COMPAT
static long tun_chr_compat_ioctl(struct file *file,
unsigned int cmd, unsigned long arg)
{
switch (cmd) {
case TUNSETIFF:
case TUNGETIFF:
case TUNSETTXFILTER:
case TUNGETSNDBUF:
case TUNSETSNDBUF:
case SIOCGIFHWADDR:
case SIOCSIFHWADDR:
arg = (unsigned long)compat_ptr(arg);
break;
default:
arg = (compat_ulong_t)arg;
break;
}
/*
* compat_ifreq is shorter than ifreq, so we must not access beyond
* the end of that structure. All fields that are used in this
* driver are compatible though, we don't need to convert the
* contents.
*/
return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
}
#endif /* CONFIG_COMPAT */
static int tun_chr_fasync(int fd, struct file *file, int on)
{
struct tun_struct *tun = tun_get(file);
int ret;
if (!tun)
return -EBADFD;
tun_debug(KERN_INFO, tun, "tun_chr_fasync %d\n", on);
if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
goto out;
if (on) {
ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
if (ret)
goto out;
tun->flags |= TUN_FASYNC;
} else
tun->flags &= ~TUN_FASYNC;
ret = 0;
out:
tun_put(tun);
return ret;
}
static int tun_chr_open(struct inode *inode, struct file * file)
{
struct tun_file *tfile;
DBG1(KERN_INFO, "tunX: tun_chr_open\n");
tfile = kmalloc(sizeof(*tfile), GFP_KERNEL);
if (!tfile)
return -ENOMEM;
atomic_set(&tfile->count, 0);
tfile->tun = NULL;
tfile->net = get_net(current->nsproxy->net_ns);
file->private_data = tfile;
return 0;
}
static int tun_chr_close(struct inode *inode, struct file *file)
{
struct tun_file *tfile = file->private_data;
struct tun_struct *tun;
tun = __tun_get(tfile);
if (tun) {
struct net_device *dev = tun->dev;
tun_debug(KERN_INFO, tun, "tun_chr_close\n");
__tun_detach(tun);
/* If desirable, unregister the netdevice. */
if (!(tun->flags & TUN_PERSIST)) {
rtnl_lock();
if (dev->reg_state == NETREG_REGISTERED)
unregister_netdevice(dev);
rtnl_unlock();
}
}
tun = tfile->tun;
if (tun)
sock_put(tun->socket.sk);
put_net(tfile->net);
kfree(tfile);
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,
.unlocked_ioctl = tun_chr_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = tun_chr_compat_ioctl,
#endif
.open = tun_chr_open,
.release = tun_chr_close,
.fasync = tun_chr_fasync
};
static struct miscdevice tun_miscdev = {
.minor = TUN_MINOR,
.name = "tun",
.nodename = "net/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;
ethtool_cmd_speed_set(cmd, 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);
strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
strlcpy(info->version, DRV_VERSION, sizeof(info->version));
switch (tun->flags & TUN_TYPE_MASK) {
case TUN_TUN_DEV:
strlcpy(info->bus_info, "tun", sizeof(info->bus_info));
break;
case TUN_TAP_DEV:
strlcpy(info->bus_info, "tap", sizeof(info->bus_info));
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 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 = ethtool_op_get_link,
};
static int __init tun_init(void)
{
int ret = 0;
pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
pr_info("%s\n", DRV_COPYRIGHT);
ret = rtnl_link_register(&tun_link_ops);
if (ret) {
pr_err("Can't register link_ops\n");
goto err_linkops;
}
ret = misc_register(&tun_miscdev);
if (ret) {
pr_err("Can't register misc device %d\n", TUN_MINOR);
goto err_misc;
}
return 0;
err_misc:
rtnl_link_unregister(&tun_link_ops);
err_linkops:
return ret;
}
static void tun_cleanup(void)
{
misc_deregister(&tun_miscdev);
rtnl_link_unregister(&tun_link_ops);
}
/* Get an underlying socket object from tun file. Returns error unless file is
* attached to a device. The returned object works like a packet socket, it
* can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
* holding a reference to the file for as long as the socket is in use. */
struct socket *tun_get_socket(struct file *file)
{
struct tun_struct *tun;
if (file->f_op != &tun_fops)
return ERR_PTR(-EINVAL);
tun = tun_get(file);
if (!tun)
return ERR_PTR(-EBADFD);
tun_put(tun);
return &tun->socket;
}
EXPORT_SYMBOL_GPL(tun_get_socket);
module_init(tun_init);
module_exit(tun_cleanup);
MODULE_DESCRIPTION(DRV_DESCRIPTION);
MODULE_AUTHOR(DRV_COPYRIGHT);
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(TUN_MINOR);
MODULE_ALIAS("devname:net/tun");
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