From 031f5e0338ef672e728c878129fa044e8830c31a Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Wed, 19 Nov 2014 14:44:40 +0200 Subject: [PATCH] tun: move internal flag defines out of uapi TUN_ flags are internal and never exposed to userspace. Any application using it is almost certainly buggy. Move them out to tun.c. Note: we remove these completely in follow-up patches, this code movement is split out for ease of review. Signed-off-by: Michael S. Tsirkin --- drivers/net/tun.c | 72 +++++++++++-------------------------- include/uapi/linux/if_tun.h | 16 ++------- 2 files changed, 24 insertions(+), 64 deletions(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 9dd3746994a4..b4e4ca01facc 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -103,6 +103,21 @@ do { \ } while (0) #endif +/* TUN device flags */ + +/* IFF_ATTACH_QUEUE is never stored in device flags, + * overload it to mean fasync when stored there. + */ +#define TUN_FASYNC IFF_ATTACH_QUEUE +#define TUN_NO_PI IFF_NO_PI +/* This flag has no real effect */ +#define TUN_ONE_QUEUE IFF_ONE_QUEUE +#define TUN_PERSIST IFF_PERSIST +#define TUN_VNET_HDR IFF_VNET_HDR +#define TUN_TAP_MQ IFF_MULTI_QUEUE + +#define TUN_FEATURES (IFF_NO_PI | IFF_ONE_QUEUE | IFF_VNET_HDR | \ + IFF_MULTI_QUEUE) #define GOODCOPY_LEN 128 #define FLT_EXACT_COUNT 8 @@ -1521,32 +1536,7 @@ static struct proto tun_proto = { 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; - - /* This flag has no real effect. We track the value for backwards - * compatibility. - */ - if (tun->flags & TUN_ONE_QUEUE) - flags |= IFF_ONE_QUEUE; - - if (tun->flags & TUN_VNET_HDR) - flags |= IFF_VNET_HDR; - - if (tun->flags & TUN_TAP_MQ) - flags |= IFF_MULTI_QUEUE; - - if (tun->flags & TUN_PERSIST) - flags |= IFF_PERSIST; - - return flags; + return tun->flags & (TUN_FEATURES | IFF_PERSIST | IFF_TUN | IFF_TAP); } static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr, @@ -1706,28 +1696,8 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) 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; - - /* This flag has no real effect. We track the value for backwards - * compatibility. - */ - 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; - - if (ifr->ifr_flags & IFF_MULTI_QUEUE) - tun->flags |= TUN_TAP_MQ; - else - tun->flags &= ~TUN_TAP_MQ; + tun->flags = (tun->flags & ~TUN_FEATURES) | + (ifr->ifr_flags & TUN_FEATURES); /* Make sure persistent devices do not get stuck in * xoff state. @@ -1890,9 +1860,9 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd, 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 | IFF_MULTI_QUEUE, + * TUNSETIFF. + */ + return put_user(IFF_TUN | IFF_TAP | TUN_FEATURES, (unsigned int __user*)argp); } else if (cmd == TUNSETQUEUE) return tun_set_queue(file, &ifr); diff --git a/include/uapi/linux/if_tun.h b/include/uapi/linux/if_tun.h index e9502dd1ee2c..277a2607d166 100644 --- a/include/uapi/linux/if_tun.h +++ b/include/uapi/linux/if_tun.h @@ -22,21 +22,11 @@ /* Read queue size */ #define TUN_READQ_SIZE 500 - -/* TUN device flags */ -#define TUN_TUN_DEV 0x0001 -#define TUN_TAP_DEV 0x0002 +/* TUN device type flags: deprecated. Use IFF_TUN/IFF_TAP instead. */ +#define TUN_TUN_DEV IFF_TUN +#define TUN_TAP_DEV IFF_TAP #define TUN_TYPE_MASK 0x000f -#define TUN_FASYNC 0x0010 -#define TUN_NOCHECKSUM 0x0020 -#define TUN_NO_PI 0x0040 -/* This flag has no real effect */ -#define TUN_ONE_QUEUE 0x0080 -#define TUN_PERSIST 0x0100 -#define TUN_VNET_HDR 0x0200 -#define TUN_TAP_MQ 0x0400 - /* Ioctl defines */ #define TUNSETNOCSUM _IOW('T', 200, int) #define TUNSETDEBUG _IOW('T', 201, int)