92 lines
2.2 KiB
Nix
92 lines
2.2 KiB
Nix
{
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config,
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lib,
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pkgs,
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...
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}: let
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cfg = config.module.kernel;
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in {
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options.module.kernel = {
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enable = lib.mkEnableOption "the kernel tweaks.";
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hardening = lib.mkOption {
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default = false;
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type = lib.types.bool;
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};
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hotspotTtlBypass = lib.mkOption {
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default = false;
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type = lib.types.bool;
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};
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latest = lib.mkOption {
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default = false;
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type = lib.types.bool;
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};
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};
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config = lib.mkIf cfg.enable (lib.mkMerge [
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{
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boot.kernel.sysctl = {
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# Allow sysrq.
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"kernel.sysrq" = 1;
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# Increase file watchers.
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"fs.inotify.max_user_event" = 9999999;
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"fs.inotify.max_user_instances" = 9999999;
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"fs.inotify.max_user_watches" = 9999999;
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# "fs.file-max" = 999999;
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};
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}
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(lib.mkIf cfg.hardening {
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boot.kernel.sysctl = {
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# Spoof protection.
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"net.ipv4.conf.all.rp_filter" = 1;
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"net.ipv4.conf.default.rp_filter" = 1;
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# Packet forwarding.
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"net.ipv4.ip_forward" = 0;
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"net.ipv6.conf.all.forwarding" = 1;
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# MITM protection.
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"net.ipv4.conf.all.accept_redirects" = 0;
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"net.ipv6.conf.all.accept_redirects" = 0;
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# Do not send ICMP redirects (we are not a router).
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"net.ipv4.conf.all.send_redirects" = 0;
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# Do not accept IP source route packets (we are not a router).
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"net.ipv4.conf.all.accept_source_route" = 0;
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"net.ipv6.conf.all.accept_source_route" = 0;
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# Protect filesystem links.
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"fs.protected_hardlinks" = 0;
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"fs.protected_symlinks" = 0;
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# Lynis config.
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"kernel.core_uses_pid" = 1;
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"kernel.kptr_restrict" = 2;
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# IP hardening.
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"net.ipv4.conf.all.log_martians" = 1;
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"net.ipv4.conf.default.accept_redirects" = 0;
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"net.ipv4.conf.default.accept_source_route" = 0;
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"net.ipv4.conf.default.log_martians" = 0;
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"net.ipv4.tcp_timestamps" = 0;
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"net.ipv6.conf.default.accept_redirects" = 0;
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# Disable ipv6.
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"net.ipv6.conf.all.disable_ipv6" = 1;
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"net.ipv6.conf.default.disable_ipv6" = 1;
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"net.ipv6.conf.lo.disable_ipv6" = 1;
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};
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})
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(lib.mkIf cfg.hotspotTtlBypass {
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boot.kernel.sysctl."net.ipv4.ip_default_ttl" = 65;
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})
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(lib.mkIf cfg.latest {
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boot.kernelPackages = pkgs.linuxPackages_latest;
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})
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]);
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}
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