kernel-netlink: Allow change of Netlink socket receive buffer size

Signed-off-by: Thomas Egerer <[email protected]>

conf/plugins/kernel-netlink.opt

@@ -1,6 +1,14 @@
 charon.plugins.kernel-netlink.buflen = <min(PAGE_SIZE, 8192)>
 	Buffer size for received Netlink messages.
 
+charon.plugins.kernel-netlink.force_receive_buffer_size = no
+	Force maximum Netlink receive buffer on Netlink socket.
+
+	If the maximum Netlink socket receive buffer in bytes set by
+	_receive_buffer_size_ exceeds the system-wide maximum from
+	/proc/sys/net/core/rmem_max, this option can be used to override the limit.
+	Enabling this option requires special priviliges (CAP_NET_ADMIN).
+
 charon.plugins.kernel-netlink.fwmark =
 	Firewall mark to set on the routing rule that directs traffic to our routing
 	table.
@@ -39,6 +47,15 @@ charon.plugins.kernel-netlink.port_bypass = no
 	port based policies use global XFRM bypass policies for the used IKE UDP
 	ports.
 
+charon.plugins.kernel-netlink.receive_buffer_size = 0
+	Maximum Netlink socket receive buffer in bytes.
+
+	Maximum Netlink socket receive buffer in bytes. This value controls how many
+	bytes of Netlink messages can be received on a Netlink socket. The default
+	value is set by /proc/sys/net/core/rmem_default. The specified value cannot
+	exceed the system-wide maximum from /proc/sys/net/core/rmem_max, unless
+	_force_receive_buffer_size_	is enabled.
+
 charon.plugins.kernel-netlink.roam_events = yes
 	Whether to trigger roam events when interfaces, addresses or routes change.