diff options
| author | Mark McLoughlin <markmc@redhat.com> | 2008-08-15 15:09:56 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2008-08-15 19:52:19 -0700 |
| commit | e3b99556975907530aeb9745e7b3945a0da48f17 (patch) | |
| tree | 97f764e5c8587efcba64ad8d0edce9fee094e143 /drivers/net/tun.c | |
| parent | 04a0551c87363f100b04d28d7a15a632b70e18e7 (diff) | |
tun: TUNGETIFF interface to query name and flags
Add a TUNGETIFF interface so that userspace can query a
tun/tap descriptor for its name and flags.
This is needed because it is common for one app to create
a tap interface, exec another app and pass it the file
descriptor for the interface. Without TUNGETIFF the spawned
app has no way of detecting wheter the interface has e.g.
IFF_VNET_HDR set.
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Acked-by: Max Krasnyansky <maxk@qualcomm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/tun.c')
| -rw-r--r-- | drivers/net/tun.c | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c index e6bbc639c2d..95931a5a988 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -748,6 +748,36 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) return err; } +static int tun_get_iff(struct net *net, struct file *file, struct ifreq *ifr) +{ + struct tun_struct *tun = file->private_data; + + if (!tun) + return -EBADFD; + + DBG(KERN_INFO "%s: tun_get_iff\n", tun->dev->name); + + strcpy(ifr->ifr_name, tun->dev->name); + + ifr->ifr_flags = 0; + + if (ifr->ifr_flags & TUN_TUN_DEV) + ifr->ifr_flags |= IFF_TUN; + else + ifr->ifr_flags |= IFF_TAP; + + if (tun->flags & TUN_NO_PI) + ifr->ifr_flags |= IFF_NO_PI; + + if (tun->flags & TUN_ONE_QUEUE) + ifr->ifr_flags |= IFF_ONE_QUEUE; + + if (tun->flags & TUN_VNET_HDR) + ifr->ifr_flags |= IFF_VNET_HDR; + + return 0; +} + /* 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) @@ -833,6 +863,15 @@ static int tun_chr_ioctl(struct inode *inode, struct file *file, DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd); switch (cmd) { + case TUNGETIFF: + ret = tun_get_iff(current->nsproxy->net_ns, file, &ifr); + if (ret) + return ret; + + if (copy_to_user(argp, &ifr, sizeof(ifr))) + return -EFAULT; + break; + case TUNSETNOCSUM: /* Disable/Enable checksum */ if (arg) |