ip blocklist by clanker

2026-03-14 23:13:10 +01:00
parent d9246f76e6
commit 1180c1b65f
4 changed files with 196 additions and 17 deletions
--- a/modules/services/blocklist.nix
+++ b/modules/services/blocklist.nix
@@ -0,0 +1,192 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+
+let
+  # --- Blocklist sources ---
+  # Add or remove URLs here. Each must be a plain list of IPs or CIDRs (one per line).
+  # Comments (#) and blank lines are stripped automatically.
+  blocklistSources = [
+    # DShield top attacking subnets (SANS ISC) — tab-separated: IP / mask / CIDR prefix
+    "https://feeds.dshield.org/block.txt"
+    # blocklist.de — scanners, bots, brute-force, scrapers
+    "https://lists.blocklist.de/lists/all.txt"
+    # GreenSnow — bots and port scanners
+    "https://blocklist.greensnow.co/greensnow.txt"
+    # Spamhaus DROP — hijacked netblocks used by cybercrime operations
+    "https://www.spamhaus.org/drop/drop.txt"
+    # FireHOL level2 — 48-hour attack tracker, pre-merged CIDRs (good all-rounder)
+    "https://raw.githubusercontent.com/firehol/blocklist-ipsets/master/firehol_level2.netset"
+  ];
+
+  # nftables table and set names — must match your existing nftables config
+  nftTable = "inet ip_drop";
+  nftSet = "blocked-ip4";
+
+  # How often to refresh (systemd calendar format)
+  refreshInterval = "*:0/4"; # every 4 hours
+
+  # --- The updater script ---
+  # Written as a pkgs.writeShellApplication so nix handles the PATH / dependencies.
+  updaterScript = pkgs.writeShellApplication {
+    name = "nft-blocklist-update";
+
+    runtimeInputs = with pkgs; [
+      curl
+      gawk
+      iproute2 # provides 'ip' for basic sanity; not strictly needed but good to have
+      nftables # provides 'nft'
+      coreutils
+    ];
+
+    text = ''
+      set -euo pipefail
+
+      NFT_TABLE="${nftTable}"
+      NFT_SET="${nftSet}"
+
+      TMPFILE=$(mktemp /tmp/nft-blocklist-XXXXXX.txt)
+      trap 'rm -f "$TMPFILE"' EXIT
+
+      echo "[blocklist] Fetching sources..."
+
+      # --- Per-source fetch + normalise ---
+      # Each source may use a different format; we normalise to bare CIDRs.
+      fetch_and_normalise() {
+        local url="$1"
+        curl --silent --fail --max-time 30 --retry 3 "$url" | \
+          awk '
+            # Skip blank lines and comment lines
+            /^[[:space:]]*$/ { next }
+            /^[[:space:]]*#/ { next }
+
+            # DShield format: "IP<tab>netmask<tab>prefix ..." — convert to CIDR
+            /^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+[[:space:]]+[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+[[:space:]]+[0-9]+/ {
+              print $1 "/" $3
+              next
+            }
+
+            # Plain CIDR (e.g. 1.2.3.0/24) — pass through
+            /^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+\/[0-9]+/ {
+              print $1
+              next
+            }
+
+            # Plain host IP (no prefix) — treat as /32
+            /^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$/ {
+              print $1 "/32"
+              next
+            }
+          '
+      }
+
+      # Fetch all sources into the temp file, skip on individual failure
+      ${lib.concatMapStringsSep "\n" (url: ''
+        echo "[blocklist] Fetching: ${url}"
+        fetch_and_normalise "${url}" >> "$TMPFILE" || \
+          echo "[blocklist] WARNING: failed to fetch ${url}, skipping" >&2
+      '') blocklistSources}
+
+      # Deduplicate lines (nft auto-merge handles overlapping CIDRs at load time)
+      sort -u "$TMPFILE" -o "$TMPFILE"
+
+      TOTAL=$(wc -l < "$TMPFILE")
+      echo "[blocklist] Total entries after dedup: $TOTAL"
+
+      if [ "$TOTAL" -eq 0 ]; then
+        echo "[blocklist] ERROR: no entries fetched — aborting to avoid flushing the set" >&2
+        exit 1
+      fi
+
+      # Build the nft element string: "1.2.3.0/24, 5.6.7.8/32, ..."
+      ELEMENTS=$(paste -sd ',' "$TMPFILE")
+
+      echo "[blocklist] Loading into nft set $NFT_TABLE / $NFT_SET ..."
+
+      # Atomic-ish update: flush then reload inside a single nft transaction
+      nft -f - <<EOF
+      flush set $NFT_TABLE $NFT_SET
+      add element $NFT_TABLE $NFT_SET { $ELEMENTS }
+      EOF
+
+      echo "[blocklist] Done. $TOTAL entries active."
+    '';
+  };
+
+in
+{
+  # -------------------------------------------------------------------------
+  # systemd one-shot service that runs the updater
+  # -------------------------------------------------------------------------
+  systemd.services.nft-blocklist-update = {
+    description = "Update nftables IP blocklist (scanners / bots / scrapers)";
+    after = [
+      "network-online.target"
+      "nftables.service"
+    ];
+    wants = [ "network-online.target" ];
+    # Also run once at boot (after nftables is up) so the set is populated immediately
+    wantedBy = [ "multi-user.target" ];
+
+    serviceConfig = {
+      Type = "oneshot";
+      ExecStart = lib.getExe updaterScript;
+      # Run as root — required to call nft
+      User = "root";
+      # Basic hardening
+      PrivateTmp = true;
+      ProtectSystem = "strict";
+      ProtectHome = true;
+      # Allow writing only to /tmp (via PrivateTmp)
+      ReadWritePaths = [ ];
+    };
+  };
+
+  # -------------------------------------------------------------------------
+  # systemd timer — fires on the configured interval
+  # -------------------------------------------------------------------------
+  systemd.timers.nft-blocklist-update = {
+    description = "Periodically refresh nftables IP blocklist";
+    wantedBy = [ "timers.target" ];
+
+    timerConfig = {
+      OnCalendar = refreshInterval;
+      # Spread the start time by up to 5 min to avoid thundering-herd
+      RandomizedDelaySec = "5m";
+      Persistent = true; # catch up if the machine was off
+    };
+  };
+
+  # -------------------------------------------------------------------------
+  # nftables — make sure the table + set exist so the updater can populate them
+  # This merges with whatever other rules you already have.
+  # -------------------------------------------------------------------------
+  networking.nftables.tables.ip_drop = {
+    family = "inet";
+    content = ''
+      set blocked-ip4 {
+        typeof ip saddr
+        flags interval
+        auto-merge
+        # starts empty; nft-blocklist-update.service fills it at boot + every 4h
+        elements = { 45.144.212.240, 74.7.227.136 }
+      }
+
+      chain input {
+        type filter hook input priority -100; policy accept;
+        ip saddr @blocked-ip4 log prefix "nftables drop: " level info counter drop
+      }
+
+      chain forward {
+        type filter hook forward priority -100; policy accept;
+        ip saddr @blocked-ip4 drop
+      }
+    '';
+  };
+
+  # Make the script available on PATH for manual runs: nft-blocklist-update
+  environment.systemPackages = [ updaterScript ];
+}
--- a/modules/services/gitea.nix
+++ b/modules/services/gitea.nix
@@ -17,6 +17,7 @@ in
      description = "FQDN under which gitea is available";
    };
  };
+  # https://docs.gitea.com/next/administration/config-cheat-sheet
  config = lib.mkIf cfg.enable {
    # Initial setup requires
    services.gitea = {
--- a/modules/services/grafana.nix
+++ b/modules/services/grafana.nix
@@ -128,6 +128,7 @@ in
    enable = true;
    port = 9000;
    globalConfig.scrape_interval = "1m";
+    retentionTime = "15d";
    #stateDir = "../../${base}/prometheus";
    exporters = {
      node = {
--- a/systems/amd-server-vm/configuration.nix
+++ b/systems/amd-server-vm/configuration.nix
@@ -20,6 +20,7 @@
    ../../modules/services/ddclient-cloudflare.nix
    ../../modules/services/grafana.nix
    ../../modules/services/coturn.nix
+    ../../modules/services/blocklist.nix
    ./disk-config.nix
    ./mail.nix
    (modulesPath + "/installer/scan/not-detected.nix")
@@ -183,25 +184,9 @@
    1234 #kop-audio default port
    #9987 # teamspeak6 voice port
  ];
-  networking.nftables.tables.ip_drop = {
-    family = "inet";
-    content = ''
-      set blocked-ip4 {
-        typeof ip saddr
-        flags interval
-        auto-merge
-        elements = { 45.144.212.240 }
-      }
-      chain input {
-        # -100 priority to run before the default filter input chain (0)
-        type filter hook input priority -100; policy accept;
-
-        ip saddr @blocked-ip4 log prefix "nftables drop: " level info counter drop
-      }
-    '';
-  };
  networking.hostName = "server-vm"; # Define your hostname.

+
  #containers.privnetwork = {
  #  autoStart = true;
  #  privateNetwork = true;