l2cap: update APIs (breaking changes)

pandora/l2cap.proto

@@ -28,17 +28,16 @@ option java_outer_classname = "L2CAPProto";
 service L2CAP {
   // Establish an L2CAP channel on an ACL connection.
   rpc Connect(ConnectRequest) returns (ConnectResponse);
-  // Await and accept incoming L2CAP channels on an existing ACL connection.
-  // Returns a stream of channel, this accept and yield channels until the stream
-  // is closed. Every incoming L2CAP channel connection request not handled by this
+  // Await and accept an incoming L2CAP channel on an existing ACL connection.
+  // Every incoming L2CAP channel connection request not handled by this
   // method should be rejected.
-  rpc OnConnection(OnConnectionRequest) returns (stream OnConnectionResponse);
+  rpc WaitConnection(WaitConnectionRequest) returns (WaitConnectionResponse);
   // Disconnect an established L2CAP channel.
   rpc Disconnect(DisconnectRequest) returns (DisconnectResponse);
   // Await an established L2CAP channel's termination.
   rpc WaitDisconnection(WaitDisconnectionRequest) returns (WaitDisconnectionResponse);
   // Fetch data received from an active L2CAP channel.
-  // Packets are yielded until the stream is closed, packets are droped otherwise. 
+  // Packets are yielded until the stream is closed, packets are dropped otherwise.
   rpc Receive(ReceiveRequest) returns (stream ReceiveResponse);
   // Send data over an L2CAP channel to a connected device.
   rpc Send(SendRequest) returns (SendResponse);
@@ -60,6 +59,23 @@ message Channel {
   google.protobuf.Any cookie = 1;
 }
 
+// Fixed channel, represented by a `Connection` and a Fixed Channel Identifier (CID).
+message FixedChannel {
+  // Specifies the underlying ACL connection, either BR/EDR (Basic Rate/Enhanced Data Rate) or BLE.
+  Connection connection = 1;
+  // Fixed Channel Identifier (CID). Represents the unique identifier for the fixed channel.
+  // Available CIDs are:
+  // - 0x0001: L2CAP Signaling Channel
+  // - 0x0002: Connectionless Channel
+  // - 0x0003: AMP Manager Protocol
+  // - 0x0004: Attribute Protocol (ATT) for BLE
+  // - 0x0005: L2CAP Signaling Channel for BLE
+  // - 0x0006: Security Manager Protocol for BLE
+  // - 0x0007: Security Manager Protocol for BR/EDR
+  // - CIDs in the range of 0x0007 to 0x003F are reserved for standardization purposes.
+  uint32 cid = 2;
+}
+
 // Request for establishing an L2CAP connection-oriented channel, 
 // where data is transmitted with acknowledgment.
 message ConnectionOrientedChannelRequest {
@@ -82,35 +98,18 @@ message CreditBasedChannelRequest {
   uint32 initial_credit = 4;
 }
 
-// Request for establishing a fixed L2CAP channel, often pre-defined for specific purposes.
-message FixedChannelRequest {
-  // Fixed Channel Identifier (CID). Represents the unique identifier for the fixed channel.
-  // Available CIDs are:
-  // - 0x0001: L2CAP Signaling Channel
-  // - 0x0002: Connectionless Channel
-  // - 0x0003: AMP Manager Protocol
-  // - 0x0004: Attribute Protocol (ATT) for BLE
-  // - 0x0005: L2CAP Signaling Channel for BLE
-  // - 0x0006: Security Manager Protocol for BLE
-  // - 0x0007: Security Manager Protocol for BR/EDR
-  // - CIDs in the range of 0x0007 to 0x003F are reserved for standardization purposes.
-  uint32 cid = 1;
-}
-
 // Request of the `Connect` method.
 message ConnectRequest {
   // Specifies the underlying ACL connection, either BR/EDR (Basic Rate/Enhanced Data Rate) or BLE.
   Connection connection = 1;
   // Defines the type and specifics of the channel to establish.
   oneof type {
-    // Request a fixed channel.
-    FixedChannelRequest fixed = 2;
     // Request a connection-oriented channel.
-    ConnectionOrientedChannelRequest basic = 3;
+    ConnectionOrientedChannelRequest basic = 2;
     // Request a BLE credit-based channel.
-    CreditBasedChannelRequest le_credit_based = 4;
+    CreditBasedChannelRequest le_credit_based = 3;
     // Request an enhanced credit-based channel.
-    CreditBasedChannelRequest enhanced_credit_based = 5;
+    CreditBasedChannelRequest enhanced_credit_based = 4;
   }
 }
 
@@ -124,25 +123,23 @@ message ConnectResponse {
   }
 }
 
-// Request of the `OnConnection` method.
-message OnConnectionRequest {
+// Request of the `WaitConnection` method.
+message WaitConnectionRequest {
   // Specifies the underlying ACL connection, either BR/EDR or BLE.
   Connection connection = 1;
   // Defines the type and specifics of the channel to wait and accept.
   oneof type {
-    // Accept fixed channels.
-    FixedChannelRequest fixed = 2;
     // Accept connection-oriented channels.
-    ConnectionOrientedChannelRequest basic = 3;
+    ConnectionOrientedChannelRequest basic = 2;
     // Accept BLE credit-based channels.
-    CreditBasedChannelRequest le_credit_based = 4;
+    CreditBasedChannelRequest le_credit_based = 3;
     // Accept enhanced credit-based channels.
-    CreditBasedChannelRequest enhanced_credit_based = 5;
+    CreditBasedChannelRequest enhanced_credit_based = 4;
   }
 }
 
-// Response of the `OnConnection` method.
-message OnConnectionResponse {
+// Response of the `WaitConnection` method.
+message WaitConnectionResponse {
   oneof result {
     CommandRejectReason error = 1;
     Channel channel = 2;
@@ -180,7 +177,12 @@ message WaitDisconnectionResponse {
 // Request of the `Receive` method.
 message ReceiveRequest {
   // Specifies the channel to fetch data from.
-  Channel channel = 1;
+  oneof source {
+    // Fetch data from a dynamic channel.
+    Channel channel = 1;
+    // Fetch data from a fixed channel.
+    FixedChannel fixed_channel = 2;
+  }
 }
 
 // Response of the `Receive` method.
@@ -192,9 +194,14 @@ message ReceiveResponse {
 // Request of the `Send` method.
 message SendRequest {
   // Specifies the channel to send data over.
-  Channel channel = 1;
+  oneof sink {
+    // Send data over a dynamic channel.
+    Channel channel = 1;
+    // Send data over a fixed channel.
+    FixedChannel fixed_channel = 2;
+  }
   // Data to be sent over the specified channel.
-  bytes data = 2;
+  bytes data = 3;
 }
 
 // Response of the `Send` method.