From 5228ddc98fa49b3cedab4024e269d62410a0d806 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Thu, 3 Jul 2008 03:46:16 -0700 Subject: [PATCH] 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 's fix to hold rtnl sem). Signed-off-by: Rusty Russell Acked-by: Max Krasnyansky Signed-off-by: David S. Miller --- drivers/net/tun.c | 49 ++++++++++++++++++++++++++++++++++++++++++ include/linux/if_tun.h | 7 ++++++ 2 files changed, 56 insertions(+) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 3bb991fd2b5..a314955e699 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -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)) diff --git a/include/linux/if_tun.h b/include/linux/if_tun.h index 94f76a11230..3f0a0995d44 100644 --- a/include/linux/if_tun.h +++ b/include/linux/if_tun.h @@ -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; -- 2.41.0