From 2f5e8e0bcd0ba4233b632a0e79bd2f1d606d236f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C4=99drzej=20Stuczy=C5=84ski?=
 <jedrzej.stuczynski@gmail.com>
Date: Wed, 9 Jul 2025 08:59:55 +0100
Subject: [PATCH] feat: forbid running mixnode + entry on the same node (#5878)

---
 nym-node/src/cli/commands/run/mod.rs | 1 +
 nym-node/src/config/mod.rs           | 7 +++++++
 2 files changed, 8 insertions(+)

diff --git a/nym-node/src/cli/commands/run/mod.rs b/nym-node/src/cli/commands/run/mod.rs
index 8b568150ed..703e47662b 100644
--- a/nym-node/src/cli/commands/run/mod.rs
+++ b/nym-node/src/cli/commands/run/mod.rs
@@ -78,6 +78,7 @@ pub(crate) async fn execute(mut args: Args) -> Result<(), NymNodeError> {
         }
         config
     };
+    config.validate()?;
 
     if !config.modes.any_enabled() {
         warn!("this node is going to run without mixnode or gateway support! consider providing `mode` value");
diff --git a/nym-node/src/config/mod.rs b/nym-node/src/config/mod.rs
index eca9289872..dfaa7eaef4 100644
--- a/nym-node/src/config/mod.rs
+++ b/nym-node/src/config/mod.rs
@@ -426,6 +426,13 @@ impl Config {
     pub fn validate(&self) -> Result<(), NymNodeError> {
         self.mixnet.validate()?;
 
+        // it's not allowed to run mixnode mode alongside entry mode
+        if self.modes.mixnode && self.modes.entry {
+            return Err(NymNodeError::config_validation_failure(
+                "illegal modes configuration - node cannot run as a mixnode and an entry gateway",
+            ));
+        }
+
         Ok(())
     }
 }