diff options
| author | Sven Eckelmann <sven@narfation.org> | 2016-10-22 09:46:24 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-10-26 17:19:07 -0400 |
| commit | 701470babace4c4bbcc8463a5609790f91f85bdb (patch) | |
| tree | 3468d1344b1e14378d18985af926817ea0b78951 | |
| parent | f806f772470d4b95df62a5d0f6e6cad5ccf49480 (diff) | |
| download | linux-701470babace4c4bbcc8463a5609790f91f85bdb.tar.gz | |
batman-adv: Revert "use core MTU range checking in misc drivers"
The maximum MTU is defined via the slave devices of an batman-adv
interface. Thus it is not possible to calculate the max_mtu during the
creation of the batman-adv device when no slave devices are attached. Doing
so would for example break non-fragmentation setups which then
(incorrectly) allow an MTU of 1500 even when underlying device cannot
transport 1500 bytes + batman-adv headers.
Checking the dynamically calculated max_mtu via the minimum of the slave
devices MTU during .ndo_change_mtu is also used by the bridge interface.
Cc: Jarod Wilson <jarod@redhat.com>
Fixes: b3e3893e1253 ("net: use core MTU range checking in misc drivers")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/batman-adv/soft-interface.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c index 112679d64be5..49e16b6e0ba3 100644 --- a/net/batman-adv/soft-interface.c +++ b/net/batman-adv/soft-interface.c @@ -158,6 +158,17 @@ static int batadv_interface_set_mac_addr(struct net_device *dev, void *p) return 0; } +static int batadv_interface_change_mtu(struct net_device *dev, int new_mtu) +{ + /* check ranges */ + if ((new_mtu < 68) || (new_mtu > batadv_hardif_min_mtu(dev))) + return -EINVAL; + + dev->mtu = new_mtu; + + return 0; +} + /** * batadv_interface_set_rx_mode - set the rx mode of a device * @dev: registered network device to modify @@ -909,6 +920,7 @@ static const struct net_device_ops batadv_netdev_ops = { .ndo_vlan_rx_add_vid = batadv_interface_add_vid, .ndo_vlan_rx_kill_vid = batadv_interface_kill_vid, .ndo_set_mac_address = batadv_interface_set_mac_addr, + .ndo_change_mtu = batadv_interface_change_mtu, .ndo_set_rx_mode = batadv_interface_set_rx_mode, .ndo_start_xmit = batadv_interface_tx, .ndo_validate_addr = eth_validate_addr, @@ -975,7 +987,6 @@ struct net_device *batadv_softif_create(struct net *net, const char *name) dev_net_set(soft_iface, net); soft_iface->rtnl_link_ops = &batadv_link_ops; - soft_iface->max_mtu = batadv_hardif_min_mtu(soft_iface); ret = register_netdevice(soft_iface); if (ret < 0) { |