From 274038f8c94c493e2977983e2aecb5f5f0778479 Mon Sep 17 00:00:00 2001 From: Pavel Emelyanov Date: Tue, 11 Jun 2013 14:41:24 +0400 Subject: [PATCH] tun: Report "persist" flag to userspace The TUN_PERSIST flag is not reported at all -- both TUNGETIFF, and sysfs "flags" attribute skip one. Knowing whether a device is persistent or not is critical for checkpoint-restore, thus I propose to add the read-only IFF_PERSIST one for this. Setting this new IFF_PERSIST is hardly possible, as TUNSETIFF doesn't check for unknown flags being zero and thus there can be trash. Signed-off-by: Pavel Emelyanov Signed-off-by: David S. Miller --- drivers/net/tun.c | 3 +++ include/uapi/linux/if_tun.h | 2 ++ 2 files changed, 5 insertions(+) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 89776c592151..b90a73165d30 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1530,6 +1530,9 @@ static int tun_flags(struct tun_struct *tun) if (tun->flags & TUN_TAP_MQ) flags |= IFF_MULTI_QUEUE; + if (tun->flags & TUN_PERSIST) + flags |= IFF_PERSIST; + return flags; } diff --git a/include/uapi/linux/if_tun.h b/include/uapi/linux/if_tun.h index 2835b85fd46d..82334f88967e 100644 --- a/include/uapi/linux/if_tun.h +++ b/include/uapi/linux/if_tun.h @@ -68,6 +68,8 @@ #define IFF_MULTI_QUEUE 0x0100 #define IFF_ATTACH_QUEUE 0x0200 #define IFF_DETACH_QUEUE 0x0400 +/* read-only flag */ +#define IFF_PERSIST 0x0800 /* Features for GSO (TUNSETOFFLOAD). */ #define TUN_F_CSUM 0x01 /* You can hand me unchecksummed packets. */ -- 2.39.5