Implement DNS management using NetworkManager

3 files changed, 112 insertions, 5 deletions

diff --git a/talpid-core/src/security/linux/dns/mod.rs b/talpid-core/src/security/linux/dns/mod.rs
index 4205d9d957..b9ebb90b1a 100644
--- a/talpid-core/src/security/linux/dns/mod.rs
+++ b/talpid-core/src/security/linux/dns/mod.rs
@@ -1,6 +1,7 @@
 mod resolvconf;
 mod static_resolv_conf;
 mod systemd_resolved;
+mod network_manager;
 
 use std::env;
 use std::net::IpAddr;
diff --git a/talpid-core/src/security/linux/dns/network_manager.rs b/talpid-core/src/security/linux/dns/network_manager.rs
new file mode 100644
index 0000000000..5bdddc7174
--- /dev/null
+++ b/talpid-core/src/security/linux/dns/network_manager.rs
@@ -0,0 +1,110 @@
+extern crate dbus;
+
+use std::collections::HashMap;
+use std::net::IpAddr;
+
+use self::dbus::arg::{RefArg, Variant};
+use self::dbus::stdintf::*;
+use self::dbus::BusType;
+
+error_chain! {
+    errors {
+        NoNetworkManager {
+            description("NetworkManager not detected")
+        }
+    }
+
+    foreign_links {
+        DbusError(dbus::Error);
+    }
+}
+
+const NM_BUS: &str = "org.freedesktop.NetworkManager";
+const NM_TOP_OBJECT: &str = "org.freedesktop.NetworkManager";
+const NM_OBJECT_PATH: &str = "/org/freedesktop/NetworkManager";
+const RPC_TIMEOUT_MS: i32 = 1000;
+const GLOBAL_DNS_CONF_KEY: &str = "GlobalDnsConfiguration";
+
+pub struct NetworkManager {
+    dbus_connection: dbus::Connection,
+}
+
+
+impl NetworkManager {
+    pub fn new() -> Result<Self> {
+        let dbus_connection = dbus::Connection::get_private(BusType::System)?;
+        let manager = NetworkManager { dbus_connection };
+        manager.ensure_network_manager_exists()?;
+        Ok(manager)
+    }
+
+    fn ensure_network_manager_exists(&self) -> Result<()> {
+        let _: Box<RefArg> = self
+            .as_manager()
+            .get(&NM_TOP_OBJECT, GLOBAL_DNS_CONF_KEY)
+            .chain_err(|| ErrorKind::NoNetworkManager)?;
+        Ok(())
+    }
+
+    fn as_manager<'a>(&'a self) -> dbus::ConnPath<'a, &'a dbus::Connection> {
+        self.dbus_connection
+            .with_path(NM_BUS, NM_OBJECT_PATH, RPC_TIMEOUT_MS)
+    }
+
+    pub fn set_dns(&mut self, servers: &[IpAddr]) -> Result<()> {
+        self.set_global_dns(create_global_settings(servers))
+    }
+
+    fn set_global_dns(&mut self, config: GlobalDnsConfig) -> Result<()> {
+        self.as_manager()
+            .set(NM_TOP_OBJECT, GLOBAL_DNS_CONF_KEY, config)
+            .map_err(|e| e.into())
+    }
+
+    pub fn reset(&mut self) -> Result<()> {
+        self.set_global_dns(create_empty_global_settings())
+    }
+}
+
+type GlobalDnsConfig = HashMap<&'static str, Variant<Box<RefArg>>>;
+
+// The NetworkManager GlobalDnsConfiguration schema looks something like this
+// {
+//  "searches": ["example.com", "search-domain.com"],
+//  "options": "this field is currently unused",
+//  "domains": {
+//   "*": {
+//     "servers": [ "1.1.1.1" ]
+//   }
+//   "example.com": {
+//     "servers": [ "8.8.8.8", "8.8.4.4" ]
+//   }
+//  }
+// }
+fn create_global_settings(server_list: &[IpAddr]) -> GlobalDnsConfig {
+    let mut global_settings = HashMap::new();
+    let mut domain_settings = HashMap::new();
+    let mut specific_domain_config = HashMap::new();
+
+    let dns_server_list = as_variant(
+        server_list
+            .iter()
+            .map(ToString::to_string)
+            .collect::<Vec<_>>(),
+    );
+    specific_domain_config.insert("servers".to_owned(), dns_server_list);
+    domain_settings.insert("*".to_owned(), as_variant(specific_domain_config));
+    global_settings.insert("domains", as_variant(domain_settings));
+    global_settings.insert("searches", as_variant(vec![] as Vec<String>));
+    global_settings.insert("options", as_variant(vec![] as Vec<String>));
+
+    global_settings
+}
+
+fn create_empty_global_settings() -> GlobalDnsConfig {
+    HashMap::new()
+}
+
+fn as_variant<T: RefArg + 'static>(t: T) -> Variant<Box<RefArg>> {
+    Variant(Box::new(t) as Box<RefArg>)
+}
diff --git a/talpid-core/src/security/linux/dns/systemd_resolved.rs b/talpid-core/src/security/linux/dns/systemd_resolved.rs
index f86ff9d7b5..e5aea9a0de 100644
--- a/talpid-core/src/security/linux/dns/systemd_resolved.rs
+++ b/talpid-core/src/security/linux/dns/systemd_resolved.rs
@@ -135,7 +135,6 @@ impl SystemdResolved {
         link_object_path: &'b dbus::Path<'static>,
         servers: &[IpAddr],
     ) -> Result<()> {
-
         let server_addresses = build_addresses_argument(servers);
 
         let mut reply = self
@@ -199,10 +198,7 @@ impl SystemdResolved {
 }
 
 fn build_addresses_argument(addresses: &[IpAddr]) -> MessageItem {
-    let addresses = addresses
-        .iter()
-        .map(ip_address_to_message_item)
-        .collect();
+    let addresses = addresses.iter().map(ip_address_to_message_item).collect();
 
     MessageItem::Array(
         MessageItemArray::new(addresses, Signature::make::<Vec<(i32, Vec<u8>)>>())