From: Nicolas Dichtel nicolas.dichtel@6wind.com
[ Upstream commit 9bb392f62447d73cc7dd7562413a2cd9104c82f8 ]
My initial goal was to fix the default MTU, which is set to 65536, ie above the maximum defined in the driver: 65535 (ETH_MAX_MTU).
In fact, it's seems more consistent, wrt min_mtu, to set the max_mtu to IP6_MAX_MTU (65535 + sizeof(struct ipv6hdr)) and use it by default.
Let's also, for consistency, set the mtu in vrf_setup(). This function calls ether_setup(), which set the mtu to 1500. Thus, the whole mtu config is done in the same function.
Before the patch: $ ip link add blue type vrf table 1234 $ ip link list blue 9: blue: <NOARP,MASTER> mtu 65536 qdisc noop state DOWN mode DEFAULT group default qlen 1000 link/ether fa:f5:27:70:24:2a brd ff:ff:ff:ff:ff:ff $ ip link set dev blue mtu 65535 $ ip link set dev blue mtu 65536 Error: mtu greater than device maximum.
Fixes: 5055376a3b44 ("net: vrf: Fix ping failed when vrf mtu is set to 0") CC: Miaohe Lin linmiaohe@huawei.com Signed-off-by: Nicolas Dichtel nicolas.dichtel@6wind.com Reviewed-by: David Ahern dsahern@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/vrf.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c index b9b7e00b72a8..bc96ac0c5769 100644 --- a/drivers/net/vrf.c +++ b/drivers/net/vrf.c @@ -1184,9 +1184,6 @@ static int vrf_dev_init(struct net_device *dev)
dev->flags = IFF_MASTER | IFF_NOARP;
- /* MTU is irrelevant for VRF device; set to 64k similar to lo */ - dev->mtu = 64 * 1024; - /* similarly, oper state is irrelevant; set to up to avoid confusion */ dev->operstate = IF_OPER_UP; netdev_lockdep_set_classes(dev); @@ -1620,7 +1617,8 @@ static void vrf_setup(struct net_device *dev) * which breaks networking. */ dev->min_mtu = IPV6_MIN_MTU; - dev->max_mtu = ETH_MAX_MTU; + dev->max_mtu = IP6_MAX_MTU; + dev->mtu = dev->max_mtu; }
static int vrf_validate(struct nlattr *tb[], struct nlattr *data[],