Merge branch 'workaround-component-id-bug'

2 files changed, 88 insertions, 5 deletions

diff --git a/talpid-core/src/tunnel/openvpn/mod.rs b/talpid-core/src/tunnel/openvpn/mod.rs
index 7f299d8e73..fd186026d4 100644
--- a/talpid-core/src/tunnel/openvpn/mod.rs
+++ b/talpid-core/src/tunnel/openvpn/mod.rs
@@ -32,7 +32,7 @@ use std::{collections::HashSet, net::IpAddr};
 #[cfg(windows)]
 use std::{ffi::OsStr, os::windows::ffi::OsStrExt, time::Instant};
 use talpid_types::net::openvpn;
-#[cfg(target_os = "linux")]
+#[cfg(any(windows, target_os = "linux"))]
 use talpid_types::ErrorExt;
 use tokio::task;
 #[cfg(target_os = "linux")]
@@ -51,6 +51,8 @@ use winapi::shared::{
     winerror::{ERROR_FILE_NOT_FOUND, NO_ERROR},
     ws2def::AF_UNSPEC,
 };
+#[cfg(windows)]
+use winreg::enums::{KEY_READ, KEY_WRITE};
 
 #[cfg(windows)]
 mod windows;
@@ -60,6 +62,7 @@ mod windows;
 lazy_static! {
     static ref ADAPTER_ALIAS: U16CString = U16CString::from_str("Mullvad").unwrap();
     static ref ADAPTER_POOL: U16CString = U16CString::from_str("Mullvad").unwrap();
+    static ref ADAPTER_GUID_STR: String = windows::string_from_guid(&ADAPTER_GUID);
 }
 
 #[cfg(windows)]
@@ -375,6 +378,38 @@ impl OpenVpnMonitor<OpenVpnCommand> {
                 log::warn!("You may need to restart Windows to complete the install of Wintun");
             }
 
+            // Workaround: OpenVPN looks up "ComponentId" to identify tunnel devices.
+            // If Wintun fails to create this registry value, create it here.
+            let adapter_key =
+                windows::find_adapter_registry_key(&*ADAPTER_GUID_STR, KEY_READ | KEY_WRITE);
+            match adapter_key {
+                Ok(adapter_key) => {
+                    let component_id: io::Result<String> = adapter_key.get_value("ComponentId");
+                    match component_id {
+                        Ok(_) => (),
+                        Err(error) => {
+                            if error.kind() == io::ErrorKind::NotFound {
+                                if let Err(error) = adapter_key.set_value("ComponentId", &"wintun")
+                                {
+                                    log::error!(
+                                        "{}",
+                                        error.display_chain_with_msg(
+                                            "Failed to set ComponentId registry value"
+                                        )
+                                    );
+                                }
+                            }
+                        }
+                    }
+                }
+                Err(error) => {
+                    log::error!(
+                        "{}",
+                        error.display_chain_with_msg("Failed to find network adapter registry key")
+                    );
+                }
+            }
+
             adapter
         };
 
@@ -696,8 +731,7 @@ impl<C: OpenVpnBuilder + 'static> OpenVpnMonitor<C> {
             .ca(resource_dir.join("ca.crt"));
         #[cfg(windows)]
         {
-            use std::ffi::OsString;
-            cmd.tunnel_alias(Some(OsString::from("Mullvad")));
+            cmd.tunnel_alias(Some(ADAPTER_ALIAS.to_os_string()));
             cmd.windows_driver(Some(crate::process::openvpn::WindowsDriver::Wintun));
         }
         if let Some(proxy_settings) = params.proxy.clone().take() {
diff --git a/talpid-core/src/tunnel/openvpn/windows.rs b/talpid-core/src/tunnel/openvpn/windows.rs
index f64892fcab..1c691794e0 100644
--- a/talpid-core/src/tunnel/openvpn/windows.rs
+++ b/talpid-core/src/tunnel/openvpn/windows.rs
@@ -13,10 +13,14 @@ use winapi::{
         guiddef::GUID,
         minwindef::{BOOL, FARPROC, HINSTANCE, HMODULE},
     },
-    um::libloaderapi::{
-        FreeLibrary, GetProcAddress, LoadLibraryExW, LOAD_WITH_ALTERED_SEARCH_PATH,
+    um::{
+        libloaderapi::{
+            FreeLibrary, GetProcAddress, LoadLibraryExW, LOAD_WITH_ALTERED_SEARCH_PATH,
+        },
+        winreg::REGSAM,
     },
 };
+use winreg::{enums::HKEY_LOCAL_MACHINE, RegKey};
 
 
 type WintunOpenAdapterFn =
@@ -241,3 +245,48 @@ impl Drop for WintunDll {
         unsafe { FreeLibrary(self.handle) };
     }
 }
+
+/// Obtain a string representation for a GUID object.
+pub fn string_from_guid(guid: &GUID) -> String {
+    use std::{ffi::OsString, os::windows::ffi::OsStringExt};
+    use winapi::um::combaseapi::StringFromGUID2;
+
+    let mut buffer = [0u16; 40];
+    let length = unsafe { StringFromGUID2(guid, &mut buffer[0] as *mut _, buffer.len() as i32 - 1) }
+        as usize;
+    if length > 0 {
+        let length = length - 1;
+        OsString::from_wide(&buffer[0..length])
+            .to_string_lossy()
+            .to_string()
+    } else {
+        "".to_string()
+    }
+}
+
+pub fn find_adapter_registry_key(find_guid: &str, permissions: REGSAM) -> io::Result<RegKey> {
+    let net_devs = RegKey::predef(HKEY_LOCAL_MACHINE).open_subkey_with_flags(
+        r"SYSTEM\CurrentControlSet\Control\Class\{4d36e972-e325-11ce-bfc1-08002be10318}",
+        permissions,
+    )?;
+    let find_guid = find_guid.to_lowercase();
+
+    for subkey_name in net_devs.enum_keys() {
+        let subkey_name = match subkey_name {
+            Ok(subkey_name) => subkey_name,
+            Err(_error) => continue,
+        };
+
+        let subkey: io::Result<RegKey> = net_devs.open_subkey_with_flags(&subkey_name, permissions);
+        if let Ok(subkey) = subkey {
+            let guid_str: io::Result<String> = subkey.get_value("NetCfgInstanceId");
+            if let Ok(guid_str) = guid_str {
+                if guid_str.to_lowercase() == find_guid {
+                    return Ok(subkey);
+                }
+            }
+        }
+    }
+
+    Err(io::Error::new(io::ErrorKind::NotFound, "device not found"))
+}