From 9fda48f589f190ce9201ca3b14380ea256c1820d Mon Sep 17 00:00:00 2001
From: Mats Rauhala <mats.rauhala@iki.fi>
Date: Tue, 15 Sep 2026 22:27:20 +0300
Subject: [PATCH] runtime: reject out-of-range HA_METRICS_PORT values

---
 src/HomeAssistant/Runtime.hs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/HomeAssistant/Runtime.hs b/src/HomeAssistant/Runtime.hs
index 68f026e..446724a 100644
--- a/src/HomeAssistant/Runtime.hs
+++ b/src/HomeAssistant/Runtime.hs
@@ -86,7 +86,9 @@ lookupPort = do
   m <- lookupEnv "HA_METRICS_PORT"
   case m of
     Nothing -> pure 8124
-    Just s  -> maybe (fail ("HA_METRICS_PORT is not a number: " <> s)) pure (readMaybe s)
+    Just s  -> case readMaybe s of
+      Just p | p >= 1 && p <= 65535 -> pure p
+      _ -> fail ("HA_METRICS_PORT must be a port in 1..65535: " <> s)
 
 defaultMain :: IO ()
 defaultMain = withSocketsDo $ do