Fix resolved by always resolving interface names to real IDs.

2 files changed, 23 insertions, 31 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 146635e87f..49b695afb9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -30,6 +30,10 @@ Line wrap the file at 100 chars.                                              Th
 - The app will have it's window resized correctly when display scaling settings are changed. This
  should also fix bad window behaviour on startup.
 
+### Fixed
+#### Linux
+- Fixed systemd-resolved DNS management.
+
 
 ## [2018.4-beta2] - 2018-10-08
 ### Added
diff --git a/talpid-core/src/security/linux/dns/systemd_resolved.rs b/talpid-core/src/security/linux/dns/systemd_resolved.rs
index e5aea9a0de..5c416187fd 100644
--- a/talpid-core/src/security/linux/dns/systemd_resolved.rs
+++ b/talpid-core/src/security/linux/dns/systemd_resolved.rs
@@ -1,6 +1,5 @@
 extern crate dbus;
 
-use std::collections::HashMap;
 use std::net::IpAddr;
 
 use error_chain::ChainedError;
@@ -54,7 +53,7 @@ lazy_static! {
 
 pub struct SystemdResolved {
     dbus_connection: dbus::Connection,
-    interface_links: HashMap<String, dbus::Path<'static>>,
+    interface_link: Option<(String, dbus::Path<'static>)>,
 }
 
 impl SystemdResolved {
@@ -63,7 +62,7 @@ impl SystemdResolved {
             dbus::Connection::get_private(BusType::System).chain_err(|| ErrorKind::DBusError)?;
         let systemd_resolved = SystemdResolved {
             dbus_connection,
-            interface_links: HashMap::new(),
+            interface_link: None,
         };
 
         systemd_resolved.ensure_resolved_exists()?;
@@ -94,23 +93,17 @@ impl SystemdResolved {
     }
 
     pub fn set_dns(&mut self, interface_name: &str, servers: &[IpAddr]) -> Result<()> {
-        let new_entry = if let Some(link_object_path) = self.interface_links.get(interface_name) {
-            self.set_link_dns(&link_object_path, servers)?;
-
-            None
-        } else {
-            let link_object_path = self.fetch_link(interface_name)?;
-
-            self.set_link_dns(&link_object_path, servers)?;
-
-            Some((interface_name.to_owned(), link_object_path))
-        };
-
-        if let Some((interface_name, link_object_path)) = new_entry {
-            self.interface_links
-                .insert(interface_name, link_object_path);
+        let link_object_path = self.fetch_link(interface_name)?;
+        if let Err(e) = self.reset() {
+            debug!(
+                "Failed to reset previous DNS settings - {}",
+                e.display_chain()
+            );
         }
 
+        self.set_link_dns(&link_object_path, servers)?;
+        self.interface_link = Some((interface_name.to_string(), link_object_path));
+
         Ok(())
     }
 
@@ -151,23 +144,18 @@ impl SystemdResolved {
     }
 
     pub fn reset(&mut self) -> Result<()> {
-        let mut result = Ok(());
-        let interface_links: Vec<_> = self.interface_links.drain().collect();
-
-        for (interface_name, link_object_path) in interface_links {
-            if let Err(error) = self.revert_link(link_object_path, &interface_name) {
-                let chained_error = error.chain_err(|| {
+        if let Some((interface_name, link_object_path)) = self.interface_link.take() {
+            self.revert_link(link_object_path, &interface_name)
+                .chain_err(|| {
                     format!(
                         "Failed to revert DNS settings of interface: {}",
                         interface_name
                     )
-                });
-                error!("{}", chained_error.display_chain());
-                result = Err(Error::from(ErrorKind::RevertDnsError));
-            }
-        }
-
-        result
+                })?;
+        } else {
+            trace!("No DNS settings to reset");
+        };
+        Ok(())
     }
 
     fn revert_link(