From 56bb3d7f7c90e2f7012d96ebbcd178ac8180df53 Mon Sep 17 00:00:00 2001
From: mikl <mikl@iscg.dev>
Date: Mon, 3 Aug 2026 08:41:57 +0300
Subject: [PATCH] feat(mesh): add selected Telegram and OpenRouter egress
 policy

---
 hosts/heather/default.nix     |  5 ++-
 hosts/heather/mesh-egress.nix | 76 +++++++++++++++++++++++++++++++++++
 2 files changed, 80 insertions(+), 1 deletion(-)
 create mode 100644 hosts/heather/mesh-egress.nix

diff --git a/hosts/heather/default.nix b/hosts/heather/default.nix
index f550076..e546a2d 100644
--- a/hosts/heather/default.nix
+++ b/hosts/heather/default.nix
@@ -22,6 +22,7 @@
     ./tuwunel-admin.nix   # matrix admin web UI (systemd, статический бинарник)
     ./pi-web.nix          # pi-web (web UI для pi coding agent, systemd + npm global)
     ./mesh-clients.nix    # Sol-style client pool (wg-clients1)
+    ./mesh-egress.nix     # Sol-style selected-destination egress policy
   ];
 
   # First server-to-server WireGuard backbone link: heather ↔ hyacinth.
@@ -57,7 +58,9 @@
     peers = [
       {
         publicKey = "BxTH8+MiA8Hv48UfpWJDVXIhbO5HgO2KTBEXIqqr23k=";
-        allowedIPs = [ "10.99.0.2/32" "10.0.0.2/32" ];
+        # Match all destinations for future policy routes; allowedIPsAsRoutes=false
+        # keeps this from installing a default route automatically.
+        allowedIPs = [ "0.0.0.0/0" ];
         endpoint = "195.242.119.59:51820";
         persistentKeepalive = 25;
       }
diff --git a/hosts/heather/mesh-egress.nix b/hosts/heather/mesh-egress.nix
new file mode 100644
index 0000000..99d941e
--- /dev/null
+++ b/hosts/heather/mesh-egress.nix
@@ -0,0 +1,76 @@
+# Static, Sol-style destination policy for selected traffic via the EU peer.
+# This is policy routing, not application learning: prefixes are declared here,
+# and OpenRouter addresses are refreshed from DNS on a timer.
+{ config, pkgs, ... }:
+let
+  ip = "${pkgs.iproute2}/bin/ip";
+  getent = "${pkgs.glibc}/bin/getent";
+  routeScript = pkgs.writeShellScript "mesh-egress-routes" ''
+    set -eu
+    ${ip} link show wg-mesh >/dev/null
+
+    # Rebuild the destination table, while leaving the normal main table alone.
+    ${ip} route flush table 1101 2>/dev/null || true
+    ${ip} rule del pref 1101 2>/dev/null || true
+    ${ip} rule add pref 1101 lookup 1101
+
+    add_route() {
+      prefix="$1"
+      ${ip} route replace "$prefix" dev wg-mesh table 1101
+    }
+
+    # Telegram DC ranges (static destination policy, as in Sol's prefix lists).
+    for prefix in \
+      91.105.192.0/23 \
+      91.108.0.0/22 \
+      91.108.4.0/22 \
+      91.108.8.0/22 \
+      91.108.12.0/22 \
+      91.108.16.0/22 \
+      91.108.20.0/22 \
+      91.108.56.0/22 \
+      95.161.64.0/20 \
+      149.154.160.0/20; do
+      add_route "$prefix"
+    done
+
+    # OpenRouter is behind a CDN; refresh its current IPv4 addresses. We do
+    # not route all Cloudflare, only the names used by the API/web endpoint.
+    for name in openrouter.ai www.openrouter.ai api.openrouter.ai; do
+      ${getent} ahostsv4 "$name" 2>/dev/null | ${pkgs.gawk}/bin/awk '{print $1}' | sort -u | while read -r addr; do
+        [ -n "$addr" ] || continue
+        add_route "$addr/32"
+      done
+    done
+  '';
+in {
+  # Clients whose selected destinations match table 1101 are forwarded to
+  # hyacinth. Other traffic keeps Heather's normal route.
+  networking.nat = {
+    enable = true;
+    internalInterfaces = [ "wg-clients1" ];
+    externalInterface = "enp7s0";
+  };
+
+  systemd.services.mesh-egress-routes = {
+    description = "Install Sol-style selected destination routes via hyacinth";
+    wantedBy = [ "network-online.target" ];
+    after = [ "network-online.target" "wireguard-wg-mesh.service" ];
+    wants = [ "wireguard-wg-mesh.service" ];
+    serviceConfig = {
+      Type = "oneshot";
+      RemainAfterExit = true;
+      ExecStart = routeScript;
+    };
+  };
+
+  systemd.timers.mesh-egress-routes = {
+    description = "Refresh selected mesh egress destinations";
+    wantedBy = [ "timers.target" ];
+    timerConfig = {
+      OnBootSec = "30s";
+      OnUnitActiveSec = "5min";
+      Unit = "mesh-egress-routes.service";
+    };
+  };
+}