[PATCH] batman-adv: Revert "use core MTU range checking in misc drivers"
From: Sven Eckelmann <sven@narfation.org>
Date: 2016-10-22 07:46:54
Also in:
batman, lkml
Subsystem:
batman advanced, the rest · Maintainers:
Marek Lindner, Simon Wunderlich, Antonio Quartulli, Sven Eckelmann, Linus Torvalds
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 <redacted>
Fixes: b3e3893e1253 ("net: use core MTU range checking in misc drivers")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
---
Original patch + my comment: https://patchwork.ozlabs.org/patch/684722/
I just got informed about this patch when it was already applied in net-next.
So I can only ask for an revet of the batman-adv parts
net/batman-adv/soft-interface.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
index 112679d..49e16b6 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) {
--
2.9.3