146 lines
4 KiB
Nix
146 lines
4 KiB
Nix
{ self, ... }: { lib, pkgs, ... }: {
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boot.consoleLogLevel = lib.mkDefault 3;
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boot.initrd = {
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checkJournalingFS = lib.mkDefault false;
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includeDefaultModules = lib.mkDefault false;
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luks.cryptoModules = lib.mkDefault [ ];
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systemd.enable = lib.mkDefault true;
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verbose = lib.mkDefault false;
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};
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boot.kernelPackages = lib.mkDefault
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(pkgs.linuxPackagesFor self.packages.${pkgs.system}.linux-hardened);
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boot.modprobeConfig.enable = lib.mkDefault false;
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boot.kernelParams = [
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# Disable kernel messages on the console
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"quiet"
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# Zero‐fill page and slab allocations on free
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"init_on_free=1"
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# Disable I/O delay
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"io_delay=none"
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# Enable page allocator free list randomisation
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"page_alloc.shuffle=1"
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# Disable slab merging
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"slab_nomerge"
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# Disable vsyscall mechanism
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"vsyscall=none"
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# Enable transparent hugepages
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"transparent_hugepage=always"
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# Suspend USB devices without delay
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"usbcore.autosuspend=0"
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];
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boot.kernel.sysctl = {
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# Mitigate some TOCTOU vulnerabilities
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"fs.protected_fifos" = 2;
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"fs.protected_hardlinks" = 1;
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"fs.protected_regular" = 2;
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"fs.protected_symlinks" = 1;
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# Disable automatic loading of TTY line disciplines
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"dev.tty.ldisc_autoload" = 0;
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# Disable first 64 KiB of virtual memory for allocation
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"vm.mmap_min_addr" = 65536;
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# Increase ASLR randomisation
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"vm.mmap_rnd_bits" = 32;
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"vm.mmap_rnd_compat_bits" = 16;
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# Restrict ptrace()
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"kernel.yama.ptrace_scope" = 1;
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# Hide kernel memory addresses
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"kernel.kptr_restrict" = 2;
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# Restrict kernel log access
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"kernel.dmesg_restrict" = 1;
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# Enable hardened eBPF JIT
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"kernel.unprivileged_bpf_disabled" = 1;
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"net.core.bpf_jit_enable" = 1;
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"net.core.bpf_jit_harden" = 2;
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# Ignore ICMP redirects
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"net.ipv4.conf.default.accept_redirects" = 0;
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"net.ipv6.conf.default.accept_redirects" = 0;
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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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# Set default Qdisc
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"net.core.default_qdisc" = "fq";
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# Increase minimum PMTU
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"net.ipv4.route.min_pmtu" = 1280;
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# Set default TCP congestion control algorithm
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"net.ipv4.tcp_congestion_control" = "bbr";
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# Enable ECN
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"net.ipv4.tcp_ecn" = 1;
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# Enable TCP fast open
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"net.ipv4.tcp_fastopen" = 3;
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# Disable TCP slow start after idling
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"net.ipv4.tcp_slow_start_after_idle" = 0;
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# Allow re‐use of TCP ports during TIME-WAIT
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"net.ipv4.tcp_tw_reuse" = 1;
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# Enable TCP MTU probing
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"net.ipv4.tcp_mtu_probing" = 1;
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"net.ipv4.tcp_mtu_probe_floor" = 1220;
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# Increase socket buffer space
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# default of 16 MiB should be sufficient to saturate 1GE
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# maximum for 54 MiB sufficient for 10GE
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"net.core.rmem_default" = 16777216;
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"net.core.rmem_max" = 56623104;
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"net.core.wmem_default" = 16777216;
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"net.core.wmem_max" = 56623104;
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"net.core.optmem_max" = 65536;
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"net.ipv4.tcp_rmem" = "4096 1048576 56623104";
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"net.ipv4.tcp_wmem" = "4096 65536 56623104";
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"net.ipv4.tcp_notsent_lowat" = 16384;
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"net.ipv4.udp_rmem_min" = 9216;
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"net.ipv4.udp_wmem_min" = 9216;
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# Reduce TCP keep‐alive time‐out to 2 minutes
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"net.ipv4.tcp_keepalive_time" = 60;
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"net.ipv4.tcp_keepalive_probes" = 6;
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"net.ipv4.tcp_keepalive_intvl" = 10;
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# Widen local port range
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"net.ipv4.ip_local_port_range" = "16384 65535";
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# Increase default MTU
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"net.ipv6.conf.default.mtu" = 1452;
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"net.ipv6.conf.all.mtu" = 1452;
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# Set traffic class for NDP to CS6 (network control)
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"net.ipv6.conf.default.ndisc_tclass" = 192;
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"net.ipv6.conf.all.ndisc_tclass" = 192;
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# Dirty page cache ratio
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"vm.dirty_background_ratio" = 3;
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"vm.dirty_ratio" = 6;
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};
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# Work around initrd generation bug
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environment.etc."modprobe.d/nixos.conf".text = "";
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systemd.tmpfiles.rules = [
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"w- /sys/kernel/mm/transparent_hugepage/enabled - - - - always"
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"w- /sys/kernel/mm/transparent_hugepage/defrag - - - - defer+madvise"
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];
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}
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