From 980c9e8ceeb69ac4c921173d0d06323f5c678647 Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Sat, 9 May 2009 22:54:21 -0700 Subject: tun: add tun_flags, owner, group attributes in sysfs This patch adds three attribute files in /sys/class/net/$dev/ for tun devices; allowing userspace to obtain the information which TUNGETIFF offers, and more, but without having to attach to the device in question (which may not be possible if it's in use). It also fixes a bug which has been present in the TUNGETIFF ioctl since its inception, where it would never set IFF_TUN or IFF_TAP according to the device type. (Look carefully at the code which I remove from tun_get_iff() and how the new tun_flags() helper is subtly different). Signed-off-by: David Woodhouse Signed-off-by: David S. Miller --- drivers/net/tun.c | 67 ++++++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 52 insertions(+), 15 deletions(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 94622e5fb936..4cda69b6b28c 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -865,6 +865,52 @@ static struct proto tun_proto = { .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 sprintf(buf, "%d\n", tun->owner); +} + +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 sprintf(buf, "%d\n", tun->group); +} + +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; @@ -950,6 +996,11 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) 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)) + printk(KERN_ERR "Failed to create tun sysfs files\n"); + sk->sk_destruct = tun_sock_destruct; err = tun_attach(tun, file); @@ -1002,21 +1053,7 @@ static int tun_get_iff(struct net *net, struct file *file, struct ifreq *ifr) 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; + ifr->ifr_flags = tun_flags(tun); tun_put(tun); return 0; -- cgit v1.2.3