Gargoyle is a free OpenWrt-based Linux distribution for a range of wireless routers based on Broadcom, Atheros, MediaTek and others chipsets, Asus Routers, Netgear, Linksys and TP-Link routers. Among notable features is the ability to limit and monitor bandwidth and set bandwidth caps per specific IP address.
Main features
Network file storage sharing, SMB, CIFS.
VPN server and VPN client (OpenVPN and WireGuard).
Tor server and Tor client.
Advertisement blocking.
Wifi scheduled on/off.
Bandwidth monitoring
Quotas, limits and bandwidth throttling
Quality of service (QoS) with active congestion control