feat(opnsense-config): dnsmasq dhcp static mappings (#130)

Co-authored-by: Jean-Gabriel Gill-Couture <jeangabriel.gc@gmail.com>
Co-authored-by: Ian Letourneau <ian@noma.to>
Reviewed-on: #130
Reviewed-by: Ian Letourneau <ian@noma.to>
Co-authored-by: Jean-Gabriel Gill-Couture <jg@nationtech.io>
Co-committed-by: Jean-Gabriel Gill-Couture <jg@nationtech.io>

opnsense-config/src/config/manager/ssh.rs

@@ -1,8 +1,9 @@
 use crate::config::{manager::ConfigManager, OPNsenseShell};
 use crate::error::Error;
 use async_trait::async_trait;
-use log::info;
+use log::{info, warn};
 use russh_keys::key::KeyPair;
+use sha2::Digest;
 use std::sync::Arc;
 
 #[derive(Debug)]
@@ -35,10 +36,10 @@ impl SshConfigManager {
             .await
     }
 
-    async fn move_to_live_config(&self, new_config_path: &str) -> Result<String, Error> {
+    async fn copy_to_live_config(&self, new_config_path: &str) -> Result<String, Error> {
         info!("Overwriting OPNSense /conf/config.xml with {new_config_path}");
         self.opnsense_shell
-            .exec(&format!("mv {new_config_path} /conf/config.xml"))
+            .exec(&format!("cp {new_config_path} /conf/config.xml"))
             .await
     }
 
@@ -56,19 +57,41 @@ impl ConfigManager for SshConfigManager {
         self.opnsense_shell.exec("cat /conf/config.xml").await
     }
 
-    async fn save_config(&self, content: &str) -> Result<(), Error> {
+    async fn save_config(&self, content: &str, hash: &str) -> Result<(), Error> {
+        let current_content = self.load_as_str().await?;
+
+        if !check_hash(&current_content, hash) {
+            warn!("OPNSense config file changed since loading it! Hash when loading : {hash}");
+            // return Err(Error::Config(format!(
+            //     "OPNSense config file changed since loading it! Hash when loading : {hash}"
+            // )));
+        }
+
         let temp_filename = self
             .opnsense_shell
             .write_content_to_temp_file(content)
             .await?;
         self.backup_config_remote().await?;
-        self.move_to_live_config(&temp_filename).await?;
+        self.copy_to_live_config(&temp_filename).await?;
         Ok(())
     }
 
-    async fn apply_new_config(&self, content: &str) -> Result<(), Error> {
-        self.save_config(content).await?;
+    async fn apply_new_config(&self, content: &str, hash: &str) -> Result<(), Error> {
+        self.save_config(content, &hash).await?;
         self.reload_all_services().await?;
         Ok(())
     }
 }
+
+pub fn get_hash(content: &str) -> String {
+    let mut hasher = sha2::Sha256::new();
+    hasher.update(content.as_bytes());
+    let hash_bytes = hasher.finalize();
+    let hash_string = format!("{:x}", hash_bytes);
+    info!("Loaded OPNSense config.xml with hash {hash_string:?}");
+    hash_string
+}
+
+pub fn check_hash(content: &str, source_hash: &str) -> bool {
+    get_hash(content) == source_hash
+}