dhcpcd: rework mtu handling on buggy nic's

[people/pmueller/ipfire-2.x.git] / config / dhcpc / dhcpcd-hooks / 10-mtu

# Configure the MTU for the interface

eval $(/usr/local/bin/readhash /var/ipfire/ethernet/settings)

set_mtu()
{
	local mtu=$1
	ip link set "$interface" mtu "$mtu"

	# test for buggy nic that lose link at mtu set...
	carrier=`cat /sys/class/net/$interface/carrier`
	if [ "$carrier" == "0" ]; then
		syslog info "Warning! Carrier loss after MTU set. Reinit ..."
		ip link set "$interface" down
		ip link set "$interface" up
	fi
}
if [ -n "$new_interface_mtu" ] && $if_up; then
	if [ $RED_DHCP_FORCE_MTU -ge 576 ]; then
		new_interface_mtu=$RED_DHCP_FORCE_MTU
	fi
	if [ ! "$new_interface_mtu" == "$ifmtu" ]; then
		# The smalled MTU dhcpcd can work with is 576
		if [ "$new_interface_mtu" -gt 576 ]; then
			if set_mtu "$new_interface_mtu"; then
				syslog info "MTU set to $new_interface_mtu"
			fi
		fi
	fi
fi