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authorSven Eckelmann <sven@narfation.org>2016-10-22 10:46:24 +0300
committerDavid S. Miller <davem@davemloft.net>2016-10-27 00:19:07 +0300
commit701470babace4c4bbcc8463a5609790f91f85bdb (patch)
tree3468d1344b1e14378d18985af926817ea0b78951 /net/batman-adv
parentf806f772470d4b95df62a5d0f6e6cad5ccf49480 (diff)
downloadlinux-701470babace4c4bbcc8463a5609790f91f85bdb.tar.xz
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>
Diffstat (limited to 'net/batman-adv')
-rw-r--r--net/batman-adv/soft-interface.c13
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) {