Notify tun provider when custom DNS servers change

6 files changed, 65 insertions, 29 deletions

diff --git a/talpid-core/src/tunnel_state_machine/connected_state.rs b/talpid-core/src/tunnel_state_machine/connected_state.rs
index f3139715c8..b150d32481 100644
--- a/talpid-core/src/tunnel_state_machine/connected_state.rs
+++ b/talpid-core/src/tunnel_state_machine/connected_state.rs
@@ -193,26 +193,35 @@ impl ConnectedState {
                 }
             }
             Some(TunnelCommand::CustomDns(servers)) => {
-                if shared_values.set_custom_dns(servers) {
-                    if let Err(error) = self.set_firewall_policy(shared_values) {
-                        return self.disconnect(
-                            shared_values,
-                            AfterDisconnect::Block(ErrorStateCause::SetFirewallPolicyError(error)),
-                        );
-                    }
-
-                    match self.set_dns(shared_values) {
-                        Ok(()) => SameState(self.into()),
-                        Err(error) => {
-                            log::error!("{}", error.display_chain_with_msg("Failed to set DNS"));
-                            self.disconnect(
+                match shared_values.set_custom_dns(servers) {
+                    Ok(true) => {
+                        if let Err(error) = self.set_firewall_policy(shared_values) {
+                            return self.disconnect(
                                 shared_values,
-                                AfterDisconnect::Block(ErrorStateCause::SetDnsError),
-                            )
+                                AfterDisconnect::Block(ErrorStateCause::SetFirewallPolicyError(
+                                    error,
+                                )),
+                            );
+                        }
+
+                        match self.set_dns(shared_values) {
+                            Ok(()) => SameState(self.into()),
+                            Err(error) => {
+                                log::error!(
+                                    "{}",
+                                    error.display_chain_with_msg("Failed to set DNS")
+                                );
+                                self.disconnect(
+                                    shared_values,
+                                    AfterDisconnect::Block(ErrorStateCause::SetDnsError),
+                                )
+                            }
                         }
                     }
-                } else {
-                    SameState(self.into())
+                    Ok(false) => SameState(self.into()),
+                    Err(error_cause) => {
+                        self.disconnect(shared_values, AfterDisconnect::Block(error_cause))
+                    }
                 }
             }
             Some(TunnelCommand::BlockWhenDisconnected(block_when_disconnected)) => {
diff --git a/talpid-core/src/tunnel_state_machine/connecting_state.rs b/talpid-core/src/tunnel_state_machine/connecting_state.rs
index 5bf6d98766..4077f6ad5e 100644
--- a/talpid-core/src/tunnel_state_machine/connecting_state.rs
+++ b/talpid-core/src/tunnel_state_machine/connecting_state.rs
@@ -236,8 +236,11 @@ impl ConnectingState {
                 }
             }
             Some(TunnelCommand::CustomDns(servers)) => {
-                shared_values.set_custom_dns(servers);
-                SameState(self.into())
+                if let Err(error_cause) = shared_values.set_custom_dns(servers) {
+                    self.disconnect(shared_values, AfterDisconnect::Block(error_cause))
+                } else {
+                    SameState(self.into())
+                }
             }
             Some(TunnelCommand::BlockWhenDisconnected(block_when_disconnected)) => {
                 shared_values.block_when_disconnected = block_when_disconnected;
diff --git a/talpid-core/src/tunnel_state_machine/disconnected_state.rs b/talpid-core/src/tunnel_state_machine/disconnected_state.rs
index 9368a832ef..dcc4660e9f 100644
--- a/talpid-core/src/tunnel_state_machine/disconnected_state.rs
+++ b/talpid-core/src/tunnel_state_machine/disconnected_state.rs
@@ -78,7 +78,11 @@ impl TunnelState for DisconnectedState {
                 SameState(self.into())
             }
             Some(TunnelCommand::CustomDns(servers)) => {
-                shared_values.set_custom_dns(servers);
+                // Same situation as allow LAN above.
+                shared_values
+                    .set_custom_dns(servers)
+                    .expect("Failed to reconnect after changing custom DNS servers");
+
                 SameState(self.into())
             }
             Some(TunnelCommand::BlockWhenDisconnected(block_when_disconnected)) => {
diff --git a/talpid-core/src/tunnel_state_machine/disconnecting_state.rs b/talpid-core/src/tunnel_state_machine/disconnecting_state.rs
index 48d8d66c05..0928834d1c 100644
--- a/talpid-core/src/tunnel_state_machine/disconnecting_state.rs
+++ b/talpid-core/src/tunnel_state_machine/disconnecting_state.rs
@@ -33,7 +33,7 @@ impl DisconnectingState {
                     AfterDisconnect::Nothing
                 }
                 Some(TunnelCommand::CustomDns(servers)) => {
-                    shared_values.set_custom_dns(servers);
+                    let _ = shared_values.set_custom_dns(servers);
                     AfterDisconnect::Nothing
                 }
                 Some(TunnelCommand::BlockWhenDisconnected(block_when_disconnected)) => {
@@ -54,7 +54,7 @@ impl DisconnectingState {
                     AfterDisconnect::Block(reason)
                 }
                 Some(TunnelCommand::CustomDns(servers)) => {
-                    shared_values.set_custom_dns(servers);
+                    let _ = shared_values.set_custom_dns(servers);
                     AfterDisconnect::Block(reason)
                 }
                 Some(TunnelCommand::BlockWhenDisconnected(block_when_disconnected)) => {
@@ -80,7 +80,7 @@ impl DisconnectingState {
                     AfterDisconnect::Reconnect(retry_attempt)
                 }
                 Some(TunnelCommand::CustomDns(servers)) => {
-                    shared_values.set_custom_dns(servers);
+                    let _ = shared_values.set_custom_dns(servers);
                     AfterDisconnect::Reconnect(retry_attempt)
                 }
                 Some(TunnelCommand::BlockWhenDisconnected(block_when_disconnected)) => {
diff --git a/talpid-core/src/tunnel_state_machine/error_state.rs b/talpid-core/src/tunnel_state_machine/error_state.rs
index 11236e3f62..a87dccd5b4 100644
--- a/talpid-core/src/tunnel_state_machine/error_state.rs
+++ b/talpid-core/src/tunnel_state_machine/error_state.rs
@@ -106,8 +106,11 @@ impl TunnelState for ErrorState {
                 }
             }
             Some(TunnelCommand::CustomDns(servers)) => {
-                shared_values.set_custom_dns(servers);
-                SameState(self.into())
+                if let Err(error_state_cause) = shared_values.set_custom_dns(servers) {
+                    NewState(Self::enter(shared_values, error_state_cause))
+                } else {
+                    SameState(self.into())
+                }
             }
             Some(TunnelCommand::BlockWhenDisconnected(block_when_disconnected)) => {
                 shared_values.block_when_disconnected = block_when_disconnected;
diff --git a/talpid-core/src/tunnel_state_machine/mod.rs b/talpid-core/src/tunnel_state_machine/mod.rs
index fb00dfab55..adafe9f16e 100644
--- a/talpid-core/src/tunnel_state_machine/mod.rs
+++ b/talpid-core/src/tunnel_state_machine/mod.rs
@@ -328,12 +328,29 @@ impl SharedTunnelStateValues {
         Ok(())
     }
 
-    pub fn set_custom_dns(&mut self, custom_dns: Option<Vec<IpAddr>>) -> bool {
+    pub fn set_custom_dns(
+        &mut self,
+        custom_dns: Option<Vec<IpAddr>>,
+    ) -> Result<bool, ErrorStateCause> {
         if self.custom_dns != custom_dns {
-            self.custom_dns = custom_dns;
-            true
+            self.custom_dns = custom_dns.clone();
+
+            #[cfg(target_os = "android")]
+            {
+                if let Err(error) = self.tun_provider.set_custom_dns_servers(custom_dns) {
+                    log::error!(
+                        "{}",
+                        error.display_chain_with_msg(
+                            "Failed to restart tunnel after changing custom DNS servers",
+                        )
+                    );
+                    return Err(ErrorStateCause::StartTunnelError);
+                }
+            }
+
+            Ok(true)
         } else {
-            false
+            Ok(false)
         }
     }