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authorKirill Tkhai <ktkhai@virtuozzo.com>2019-03-20 12:16:42 +0300
committerDavid S. Miller <davem@davemloft.net>2019-03-21 13:19:15 -0700
commit0c3e0e3bb623c3735b8c9ab8aa8332f944f83a9f (patch)
treea0bf65cefd6045f9942a5f010121d4a73964b1b8
parentMerge branch 'ipv6-Change-addrconf_f6i_alloc-to-use-ip6_route_info_create' (diff)
downloadlinux-dev-0c3e0e3bb623c3735b8c9ab8aa8332f944f83a9f.tar.xz
linux-dev-0c3e0e3bb623c3735b8c9ab8aa8332f944f83a9f.zip
tun: Add ioctl() TUNGETDEVNETNS cmd to allow obtaining real net ns of tun device
In commit f2780d6d7475 "tun: Add ioctl() SIOCGSKNS cmd to allow obtaining net ns of tun device" it was missed that tun may change its net ns, while net ns of socket remains the same as it was created initially. SIOCGSKNS returns net ns of socket, so it is not suitable for obtaining net ns of device. We may have two tun devices with the same names in two net ns, and in this case it's not possible to determ, which of them fd refers to (TUNGETIFF will return the same name). This patch adds new ioctl() cmd for obtaining net ns of a device. Reported-by: Harald Albrecht <harald.albrecht@gmx.net> Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/tun.c8
-rw-r--r--include/uapi/linux/if_tun.h1
2 files changed, 9 insertions, 0 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index ef3b65514976..60d0a4e60ec5 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -3102,6 +3102,7 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %u\n", cmd);
+ net = dev_net(tun->dev);
ret = 0;
switch (cmd) {
case TUNGETIFF:
@@ -3327,6 +3328,13 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
ret = tun_net_change_carrier(tun->dev, (bool)carrier);
break;
+ case TUNGETDEVNETNS:
+ ret = -EPERM;
+ if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
+ goto unlock;
+ ret = open_related_ns(&net->ns, get_net_ns);
+ break;
+
default:
ret = -EINVAL;
break;
diff --git a/include/uapi/linux/if_tun.h b/include/uapi/linux/if_tun.h
index 23a6753b37df..454ae31b93c7 100644
--- a/include/uapi/linux/if_tun.h
+++ b/include/uapi/linux/if_tun.h
@@ -60,6 +60,7 @@
#define TUNSETSTEERINGEBPF _IOR('T', 224, int)
#define TUNSETFILTEREBPF _IOR('T', 225, int)
#define TUNSETCARRIER _IOW('T', 226, int)
+#define TUNGETDEVNETNS _IO('T', 227)
/* TUNSETIFF ifr flags */
#define IFF_TUN 0x0001