Hooks are provided at the network layer for IPv4 to facilitate:
Existing Netfilter [23] hooks are used to provide access to IP datagrams in pre-routing, local input, forwarding, local output and post-routing phases. Through these hooks, LSM intercepts packets before and after the standard iptables-based access control and translation mechanisms. Note that the Netfilter hooks used by LSM do not increase the code footprint imposed by LSM on the standard kernel.