diff options
| author | Patrick Rohr <prohr@google.com> | 2022-09-20 12:48:25 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2022-09-23 12:02:03 +0100 |
| commit | 195624d9c26b64c6856863da30ec578a790feec4 (patch) | |
| tree | b59b33f799ab16cd2bf18fee50074a58f8e2db5b /drivers/net/tun.c | |
| parent | 504c25cb76a9cb805407f7701b25a1fbd48605fa (diff) | |
tun: support not enabling carrier in TUNSETIFF
This change adds support for not enabling carrier during TUNSETIFF
interface creation by specifying the IFF_NO_CARRIER flag.
Our tests make heavy use of tun interfaces. In some scenarios, the test
process creates the interface but another process brings it up after the
interface is discovered via netlink notification. In that case, it is
not possible to create a tun/tap interface with carrier off without it
racing against the bring up. Immediately setting carrier off via
TUNSETCARRIER is still too late.
Signed-off-by: Patrick Rohr <prohr@google.com>
Cc: Maciej Żenczykowski <maze@google.com>
Cc: Lorenzo Colitti <lorenzo@google.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: Maciej Żenczykowski <maze@google.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/tun.c')
| -rw-r--r-- | drivers/net/tun.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 259b2b84b2b3..db736b944016 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -2828,7 +2828,10 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) rcu_assign_pointer(tfile->tun, tun); } - netif_carrier_on(tun->dev); + if (ifr->ifr_flags & IFF_NO_CARRIER) + netif_carrier_off(tun->dev); + else + netif_carrier_on(tun->dev); /* Make sure persistent devices do not get stuck in * xoff state. @@ -3056,8 +3059,8 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd, * This is needed because we never checked for invalid flags on * TUNSETIFF. */ - return put_user(IFF_TUN | IFF_TAP | TUN_FEATURES, - (unsigned int __user*)argp); + return put_user(IFF_TUN | IFF_TAP | IFF_NO_CARRIER | + TUN_FEATURES, (unsigned int __user*)argp); } else if (cmd == TUNSETQUEUE) { return tun_set_queue(file, &ifr); } else if (cmd == SIOCGSKNS) { |