Allow compiling protos from other workspaces

Ref #4573
Ref #4587

micro_rpc_workspace_test/Cargo.toml

@@ -5,6 +5,12 @@ edition = "2021"
 license = "Apache-2.0"
 
 [dependencies]
+oak_crypto = { path = "../oak_crypto" }
 micro_rpc = { path = "../micro_rpc" }
+prost = "*"
+tonic = "*"
+
+[build-dependencies]
+oak_grpc_utils = { path = "../oak_grpc_utils" }
 
 [workspace]

micro_rpc_workspace_test/build.rs

@@ -0,0 +1,33 @@
+//
+// Copyright 2024 The Project Oak Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+use oak_grpc_utils::{generate_grpc_code, CodegenOptions, ExternPath};
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    generate_grpc_code(
+        "proto",
+        &["test.proto", "stubs.proto"],
+        CodegenOptions {
+            extern_paths: vec![ExternPath::new(
+                ".oak.crypto.v1",
+                "::oak_crypto::proto::oak::crypto::v1",
+            )],
+            ..Default::default()
+        },
+    )?;
+
+    Ok(())
+}

micro_rpc_workspace_test/deny.toml

@@ -27,6 +27,7 @@ unknown-git = "allow"
 allow = [
   "Apache-2.0",
   "Apache-2.0 WITH LLVM-exception",
+  "BSD-3-Clause",
   "MIT",
   "Unicode-DFS-2016",
 ]

micro_rpc_workspace_test/proto/stubs.proto

@@ -0,0 +1,26 @@
+//
+// Copyright 2024 The Project Oak Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+syntax = "proto3";
+
+// This file contains empty proto message stubs to make protoc happy when compiling code that
+// depends on Oak protos that are not available in other repos.
+// The actual implementations are provided in Rust using the `extern_paths` option of
+// tonic: https://docs.rs/tonic-build/0.10.2/tonic_build/struct.Builder.html#method.extern_path
+// See also the `build.rs` file in this crate.
+package oak.crypto.v1;
+
+message EncryptedRequest {}

micro_rpc_workspace_test/proto/test.proto

@@ -0,0 +1,25 @@
+//
+// Copyright 2024 The Project Oak Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+syntax = "proto3";
+
+import "stubs.proto";
+
+package oak.test;
+
+message TestRequestWrapper {
+  .oak.crypto.v1.EncryptedRequest encrypted_request = 1;
+}

micro_rpc_workspace_test/src/lib.rs

@@ -14,6 +14,14 @@
 // limitations under the License.
 //
 
+mod proto {
+    pub mod oak {
+        pub mod test {
+            tonic::include_proto!("oak.test");
+        }
+    }
+}
+
 // Test to confirm that the dependency on micro_rpc and its own protobuf types works correctly.
 #[test]
 fn micro_rpc_dep_test() {
@@ -27,3 +35,23 @@ fn micro_rpc_dep_test() {
         r##"ResponseWrapper { response: Some(Error(Status { code: 3, message: "error" })) }"##
     );
 }
+
+// Test to confirm that the dependency on oak_crypto and its own protobuf types works correctly.
+#[test]
+fn oak_crypto_dep_test() {
+    let request_wrapper = proto::oak::test::TestRequestWrapper {
+        encrypted_request: Some(oak_crypto::proto::oak::crypto::v1::EncryptedRequest {
+            encrypted_message: Some(oak_crypto::proto::oak::crypto::v1::AeadEncryptedMessage {
+                associated_data: vec![],
+                nonce: vec![],
+                ciphertext: vec![],
+            }),
+            serialized_encapsulated_public_key: Some(vec![]),
+        }),
+    };
+
+    assert_eq!(
+        format!("{request_wrapper:?}"),
+        r##"TestRequestWrapper { encrypted_request: Some(EncryptedRequest { encrypted_message: Some(AeadEncryptedMessage { ciphertext: [], associated_data: [], nonce: [] }), serialized_encapsulated_public_key: Some([]) }) }"##
+    );
+}

oak_grpc_utils/src/lib.rs

@@ -42,21 +42,23 @@ impl ExternPath {
 
 /// Generate gRPC code from Protobuf using `tonic` library.
 ///
-/// The path to the root repository must be passed as `proto_path`. All paths to `.proto` files
+/// The path to the root repository must be passed as `include`. All paths to `.proto` files
 /// must be specified relative to this path. Likewise, all imported paths in `.proto` files must
 /// be specified relative to this path.
+// TODO(#4588): Swap the include and protos arguments, so they match the order of the
+// corresponding arguments in the `tonic_build::configure()` function.
 pub fn generate_grpc_code(
-    proto_path: &str,
-    file_paths: &[&str],
+    include: &str,
+    protos: &[&str],
     options: CodegenOptions,
 ) -> std::io::Result<()> {
     set_protoc_env_if_unset();
 
     // TODO(#1093): Move all proto generation to a common crate.
-    let proto_path = std::path::Path::new(proto_path);
-    let file_paths: Vec<std::path::PathBuf> = file_paths
+    let include = std::path::Path::new(include);
+    let file_paths: Vec<std::path::PathBuf> = protos
         .iter()
-        .map(|file_path| proto_path.join(file_path))
+        .map(|file_path| include.join(file_path))
         .collect();
 
     // Generate the normal (non-Oak) server and client code for the gRPC service,
@@ -80,7 +82,7 @@ pub fn generate_grpc_code(
     for extern_path in options.extern_paths {
         config = config.extern_path(extern_path.proto_path, extern_path.rust_path);
     }
-    config.compile(&file_paths, &[proto_path.to_path_buf()])
+    config.compile(&file_paths, &[include])
 }
 
 fn set_protoc_env_if_unset() {