Merge pull request #274 from betrusted-io/xous-names-tryconnect

Add TryConnect call to xous-names

api/xous-api-names/src/api.rs

@@ -52,6 +52,34 @@ pub enum Opcode {
  /// }
  /// ```
  BlockingConnect = 6,
+
+ /// Connect to a Server, returning the connection ID or an authentication request if
+ /// it exists, and returning ServerNotFound if it does not exist.
+ ///
+ /// # Message Types
+ ///
+ /// * MutableLend
+ ///
+ /// # Arguments
+ ///
+ /// The memory being pointed to should be a &str, and the length of the string should
+ /// be specified in the `valid` field.
+ ///
+ /// # Return Values
+ ///
+ /// Memory is overwritten to contain a return value. This return value can be defined
+ /// as the following enum:
+ ///
+ /// ```rust
+ /// #[repr(C)]
+ /// #[non_exhaustive]
+ /// enum ConnectResult {
+ /// Success(xous::CID /* connection ID */, [u32; 4] /* Disconnection token */),
+ /// Error(u32 /* error code */),
+ /// Unhandled, /* Catchall for future Results */
+ /// }
+ /// ```
+ TryConnect = 7,
 }
 
 #[derive(Debug, rkyv::Archive, rkyv::Serialize, rkyv::Deserialize)]

services/xous-names/src/main.rs

@@ -26,6 +26,9 @@ enum ConnectError {
 
  /// The message was not a mutable memory message
  InvalidMessageType = 4,
+
+ /// The server does not currently exist, and a blocking request was made
+ ServerNotFound = 5,
 }
 
 #[derive(PartialEq)]
@@ -464,7 +467,7 @@ fn main() -> ! {
  xous::return_scalar(msg.sender, 0).unwrap();
  }
  }),
- Some(api::Opcode::BlockingConnect) => {
+ Some(api::Opcode::BlockingConnect) | Some(api::Opcode::TryConnect) => {
  if !msg.body.is_blocking() {
  continue;
  }
@@ -479,9 +482,13 @@ fn main() -> ! {
  respond_connect_success(msg, cid, disc)
  }
  Ok(ConnectSuccess::Wait) => {
- // Push waiting connections here, which will prevent it from getting
- // dropped and responded to.
- waiting_connections.push(msg);
+ if msg.body.id() == api::Opcode::TryConnect as usize {
+ respond_connect_error(msg, ConnectError::ServerNotFound);
+ } else {
+ // Push waiting connections here, which will prevent it from getting
+ // dropped and responded to.
+ waiting_connections.push(msg);
+ }
  }
  }
  }