nx9-wg/docs/linux_requirements.md

Linux Platform and Kernel Requirements

nx9-wg is designed for native Linux execution and interacts directly with Linux kernel subsystems via Netlink sockets and direct /proc filesystem interfaces.

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1. Kernel Requirements

• Linux Kernel Version: 5.6 or newer (in-tree WireGuard module support).
• WireGuard Subsystem: wireguard.ko in-tree module (modprobe wireguard).
• Generic Netlink (Genl): Family wireguard for cryptographic interface and peer configuration.
• RTNETLINK: For network interface lifecycle (RTM_NEWLINK/DELLINK), address assignments (RTM_NEWADDR), and routing table management (RTM_NEWROUTE/DELROUTE).
• Sysctl IP Forwarding: Direct procfs mutation:
  • /proc/sys/net/ipv4/ip_forward (enabled for IPv4 packet routing)
  • /proc/sys/net/ipv6/conf/all/forwarding (enabled for IPv6 dual-stack routing)

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2. Dynamic Library & Runtime Dependencies

When compiled for Linux, nx9-wg links dynamically against standard system libraries:

Library	Runtime Function	Installation Package (Debian/Ubuntu)	Installation Package (RHEL/Fedora/Arch)
libnftables.so.1	Native nftables ruleset execution	libnftables1 / nftables	libnftables / nftables
libmnl.so.0	Minimal Netlink library	libmnl0	libmnl
libnftnl.so.11	Netfilter Netlink object library	libnftnl11	libnftnl
libc.so.6	Standard C library (glibc / musl)	Base system	Base system

Note

SQLite is statically embedded into the nx9-wg binary via libsqlite3-sys. No external SQLite installation or database daemon is required.

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3. Security Capabilities & Privilege Boundaries

When executed under systemd or non-root service accounts:

• CAP_NET_ADMIN: Strictly required for RTNETLINK interface lifecycle, IP route mutations, WireGuard Genl socket communication, and nftables Netfilter execution.
• CAP_NET_BIND_SERVICE: Required if binding the REST API or WireGuard UDP socket to privileged ports (< 1024).

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4. Execution Mode Classification

• Linux Native Mode: Automatically engaged on Linux systems with CAP_NET_ADMIN and kernel WireGuard/Netfilter modules.
• Non-Linux / Simulated Mode: Automatically engaged on macOS and Windows hosts for development and UI preview.
• Restricted Mode: Engaged when running on Linux without CAP_NET_ADMIN; control-plane REST API, SQLite queries, and diagnostics operate normally, while kernel mutation calls return descriptive permission errors without crashing.