tun: TUNSETFEATURES to set gso features.

ethtool is useful for setting (some) device fields, but it's
root-only.  Finer feature control is available through a tun-specific
ioctl.

(Includes Mark McLoughlin <markmc@redhat.com>'s fix to hold rtnl sem).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Max Krasnyansky <maxk@qualcomm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Rusty Russell 2008-07-03 03:46:16 -07:00 committed by David S. Miller
parent 07240fd090
commit 5228ddc98f
2 changed files with 56 additions and 0 deletions

View file

@ -611,6 +611,46 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
return err;
}
/* 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;
}
static int tun_chr_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
@ -715,6 +755,15 @@ static int tun_chr_ioctl(struct inode *inode, struct file *file,
break;
#endif
case TUNSETOFFLOAD:
{
int ret;
rtnl_lock();
ret = set_offload(tun->dev, arg);
rtnl_unlock();
return ret;
}
case SIOCGIFFLAGS:
ifr.ifr_flags = tun->if_flags;
if (copy_to_user( argp, &ifr, sizeof ifr))

View file

@ -41,6 +41,7 @@
#define TUNSETLINK _IOW('T', 205, int)
#define TUNSETGROUP _IOW('T', 206, int)
#define TUNGETFEATURES _IOR('T', 207, unsigned int)
#define TUNSETOFFLOAD _IOW('T', 208, unsigned int)
/* TUNSETIFF ifr flags */
#define IFF_TUN 0x0001
@ -48,6 +49,12 @@
#define IFF_NO_PI 0x1000
#define IFF_ONE_QUEUE 0x2000
/* Features for GSO (TUNSETOFFLOAD). */
#define TUN_F_CSUM 0x01 /* You can hand me unchecksummed packets. */
#define TUN_F_TSO4 0x02 /* I can handle TSO for IPv4 packets */
#define TUN_F_TSO6 0x04 /* I can handle TSO for IPv6 packets */
#define TUN_F_TSO_ECN 0x08 /* I can handle TSO with ECN bits. */
struct tun_pi {
unsigned short flags;
__be16 proto;