ensure chain jump is added only onceadd-firewall-rules

1 files changed, 6 insertions, 5 deletions

diff --git a/src/fw.rs b/src/fw.rs
index 42ce73a..8ee3e6b 100644
--- a/src/fw.rs
+++ b/src/fw.rs
@@ -1,7 +1,6 @@
 use iptables;
 use regex::Regex;
 use std::collections::HashSet;
-use std::io;
 use crate::messages;
 
 #[derive(Debug)]
@@ -14,15 +13,17 @@ impl From<iptables::error::IPTError> for FirewallError {
 }
 
 pub fn setup(ipt: &iptables::IPTables) -> Result<(), FirewallError> {
-    
-    ipt.new_chain("filter", "DIPLONAT")?;
-    ipt.insert("filter", "INPUT", "-j DIPLONAT", 1)?;
+
+    if !ipt.chain_exists("filter", "DIPLONAT")? {
+        ipt.new_chain("filter", "DIPLONAT")?;
+    }
+
+    ipt.insert_unique("filter", "INPUT", "-j DIPLONAT", 1)?;
 
     Ok(())
 }
 
 pub fn open_ports(ipt: &iptables::IPTables, ports: messages::PublicExposedPorts) -> Result<(), FirewallError> {
-
     for p in ports.tcp_ports {
         ipt.append("filter", "DIPLONAT", &format!("-p tcp --dport {} -j ACCEPT", p))?;
     }