Create routes-macos.sh

routes-macos.sh

@@ -0,0 +1,43 @@
+#!/bin/zsh
+set -u
+
+default_info="$(route -n get default 2>/dev/null || true)"
+default_if="$(printf '%s\n' "$default_info" | awk '/interface:/{print $2; exit}')"
+gateway="$(printf '%s\n' "$default_info" | awk '/gateway:/{print $2; exit}')"
+
+if [[ -n "${default_if:-}" && "$default_if" == utun* ]]; then
+  echo "Default route is currently $default_if. Disconnect WireGuard/VPN first." >&2
+  exit 1
+fi
+
+if [[ -z "${gateway:-}" ]]; then
+  echo "Could not determine normal default gateway." >&2
+  exit 1
+fi
+
+while IFS= read -r line; do
+  line="${line//$'\r'/}"
+
+  # Try to extract:
+  # - plain IPv4
+  # - IPv4/CIDR
+  # - relayed-address=IPv4:port  -> use only IPv4
+  remote="$(printf '%s\n' "$line" | sed -nE '
+    s/.*relayed-address=(([0-9]{1,3}\.){3}[0-9]{1,3}):[0-9]+.*/\1/p
+    t done
+    s/^(([0-9]{1,3}\.){3}[0-9]{1,3}\/[0-9]{1,2})$/\1/p
+    t done
+    s/^(([0-9]{1,3}\.){3}[0-9]{1,3})$/\1/p
+    :done
+  ')"
+
+  [[ -z "$remote" ]] && continue
+
+  if [[ "$remote" == */* ]]; then
+    sudo route -n delete -net "$remote" >/dev/null 2>&1 || true
+    sudo route -n add -net "$remote" "$gateway" || true
+  else
+    sudo route -n delete -host "$remote" >/dev/null 2>&1 || true
+    sudo route -n add -host "$remote" "$gateway" || true
+  fi
+done