This is a summary of the main changes in the kernel that diverge from mainline.
- added net/netfilter/xt_qtaguid*
- imported then modified net/netfilter/xt_quota2.c from xtables-addons project
- fixes in net/netfilter/ip6_tables.c
- modified ip*t_REJECT.c
- modified net/netfilter/xt_socket.c
A few comments on the kernel configuration:
- xt_qtaguid masquerades as xt_owner and relies on xt_socket and itself relies on the connection tracker.
- Support for xt_qtaguid will be phased out starting in the Android 9 release. See eBPF Traffic Monitoring for more information.
- The connection tracker can't handle large SIP packets, it must be disabled.
- The modified xt_quota2 uses the NFLOG support to notify userspace.