protos: Compile protos for trunks daemon

The TPM device will need these protos to communicate TPM commands to the
Trunks daemon and receive TPM responses.

BUG=chromium:911799
TEST=cargo check
TEST=cargo check --features tpm
TEST=FEATURES=test emerge-nami crosvm
TEST=FEATURES=test USE=crosvm-tpm emerge-nami crosvm
TEST=local kokoro
CQ-DEPEND=CL:1553610
CQ-DEPEND=CL:1553971

Change-Id: I1a67a7b4a3714236b20a790068ca19129446f71c
Reviewed-on: https://chromium-review.googlesource.com/1554982
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: David Tolnay <dtolnay@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: David Tolnay <dtolnay@chromium.org>
Reviewed-by: Zach Reizner <zachr@chromium.org>
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>

7 files changed, 162 insertions, 1 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 1b28355..19667d1 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -152,6 +152,7 @@ dependencies = [
  "net_sys 0.1.0",
  "net_util 0.1.0",
  "p9 0.1.0",
+ "protos 0.1.0",
  "resources 0.1.0",
  "sync 0.1.0",
  "sys_util 0.1.0",
@@ -385,6 +386,14 @@ dependencies = [
 ]
 
 [[package]]
+name = "protos"
+version = "0.1.0"
+dependencies = [
+ "protobuf 2.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "protoc-rust 2.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "qcow"
 version = "0.1.0"
 dependencies = [
diff --git a/devices/Cargo.toml b/devices/Cargo.toml
index c1ddad0..d916df8 100644
--- a/devices/Cargo.toml
+++ b/devices/Cargo.toml
@@ -6,7 +6,7 @@ authors = ["The Chromium OS Authors"]
 [features]
 gpu = ["gpu_buffer", "gpu_display", "gpu_renderer"]
 sandboxed-libusb = ["usb_util/sandboxed-libusb"]
-tpm = ["tpm2"]
+tpm = ["protos", "tpm2"]
 wl-dmabuf = []
 
 [dependencies]
@@ -26,6 +26,7 @@ msg_socket = { path = "../msg_socket" }
 net_sys = { path = "../net_sys" }
 net_util = { path = "../net_util" }
 p9 = { path = "../p9" }
+protos = { path = "../protos", optional = true }
 resources = { path = "../resources" }
 sync = { path = "../sync" }
 sys_util = { path = "../sys_util" }
diff --git a/protos/Cargo.toml b/protos/Cargo.toml
new file mode 100644
index 0000000..1bc2c49
--- /dev/null
+++ b/protos/Cargo.toml
@@ -0,0 +1,11 @@
+[package]
+name = "protos"
+version = "0.1.0"
+authors = ["The Chromium OS Authors"]
+edition = "2018"
+
+[dependencies]
+protobuf = "2.3"
+
+[build-dependencies]
+protoc-rust = "2.3"
diff --git a/protos/build.rs b/protos/build.rs
new file mode 100644
index 0000000..f4f5d97
--- /dev/null
+++ b/protos/build.rs
@@ -0,0 +1,78 @@
+// Copyright 2019 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+use std::env;
+use std::error::Error;
+use std::fs::File;
+use std::io::Write;
+use std::path::PathBuf;
+
+type Result<T> = std::result::Result<T, Box<dyn Error>>;
+
+struct Proto {
+    // Where to find protos during builds within cros_sdk. Relative to $SYSROOT
+    // environment variable set by emerge builds.
+    dir_relative_to_sysroot: &'static str,
+
+    // Where to find protos during "cargo build" in a local developer
+    // environment. Relative to the platform/crosvm/protos directory.
+    dir_relative_to_us: &'static str,
+
+    // *.proto file expected to exist in both of the above directories.
+    proto_file_name: &'static str,
+
+    // Code generated by proto compiler will be exported under
+    // protos::$module_name.
+    name_for_module: &'static str,
+}
+
+static PROTOS: &[Proto] = &[Proto {
+    dir_relative_to_sysroot: "usr/include/chromeos/dbus/trunks",
+    dir_relative_to_us: "../../../platform2/trunks",
+    proto_file_name: "interface.proto",
+    name_for_module: "trunks",
+}];
+
+fn paths_to_strs(paths: &[PathBuf]) -> Vec<&str> {
+    paths
+        .iter()
+        .map(|p| p.as_os_str().to_str().unwrap())
+        .collect()
+}
+
+fn main() -> Result<()> {
+    let out_dir = env::var("OUT_DIR")?;
+    let sysroot = env::var_os("SYSROOT");
+
+    // Write out a Rust module that imports the modules generated by protoc.
+    let protos_rs = PathBuf::from(&out_dir).join("protos.rs");
+    let mut out = File::create(protos_rs)?;
+
+    let mut input_files = Vec::new();
+    let mut include_dirs = Vec::new();
+
+    for proto in PROTOS {
+        let dir = match &sysroot {
+            Some(dir) => PathBuf::from(dir).join(proto.dir_relative_to_sysroot),
+            None => PathBuf::from(proto.dir_relative_to_us),
+        };
+
+        input_files.push(dir.join(proto.proto_file_name));
+        include_dirs.push(dir);
+
+        let generated_module = proto.proto_file_name.replace(".proto", "");
+        writeln!(out, "#[path = \"{}/{}.rs\"]", out_dir, generated_module)?;
+        writeln!(out, "pub mod {};", proto.name_for_module)?;
+    }
+
+    // Invoke proto compiler.
+    protoc_rust::run(protoc_rust::Args {
+        out_dir: &out_dir,
+        input: &paths_to_strs(&input_files),
+        includes: &paths_to_strs(&include_dirs),
+        ..Default::default()
+    })?;
+
+    Ok(())
+}
diff --git a/protos/src/lib.rs b/protos/src/lib.rs
new file mode 100644
index 0000000..5381935
--- /dev/null
+++ b/protos/src/lib.rs
@@ -0,0 +1,5 @@
+// Copyright 2019 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+include!(concat!(env!("OUT_DIR"), "/protos.rs"));
diff --git a/protos/tests/common/mod.rs b/protos/tests/common/mod.rs
new file mode 100644
index 0000000..a5aaf07
--- /dev/null
+++ b/protos/tests/common/mod.rs
@@ -0,0 +1,35 @@
+// Copyright 2019 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+use protobuf::Message;
+
+/// Asserts that a given protobuf message object can be serialized to bytes and
+/// read back into a value of the same type, preserving equality between the
+/// original object and the one read back.
+///
+/// This is helpful for confirming that proto files have been compiled
+/// successfully and are exposed as intended by the public API of the parent
+/// crate. It also lets us exercise the full set of methods we intend to use for
+/// building particular proto objects so that we notice breakage early in the
+/// event that a proto external to this repository would make a breaking change.
+///
+/// Note: assumes that the given `message` is not just `T::new` so that we can
+/// tell that deserialization has happened successfully.
+///
+/// # Example
+///
+/// ```ignore
+/// let mut request = SendCommandRequest::new();
+/// request.set_command(b"...".to_vec());
+/// test_round_trip(request);
+/// ```
+pub fn test_round_trip<T: Message + PartialEq>(message: T) {
+    let serialized = message.write_to_bytes().unwrap();
+
+    let mut back = T::new();
+    assert_ne!(message, back);
+
+    back.merge_from_bytes(&serialized).unwrap();
+    assert_eq!(message, back);
+}
diff --git a/protos/tests/trunks.rs b/protos/tests/trunks.rs
new file mode 100644
index 0000000..574c110
--- /dev/null
+++ b/protos/tests/trunks.rs
@@ -0,0 +1,22 @@
+// Copyright 2019 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+mod common;
+
+use crate::common::test_round_trip;
+use protos::trunks::{SendCommandRequest, SendCommandResponse};
+
+#[test]
+fn send_command_request() {
+    let mut request = SendCommandRequest::new();
+    request.set_command(b"...".to_vec());
+    test_round_trip(request);
+}
+
+#[test]
+fn send_command_response() {
+    let mut response = SendCommandResponse::new();
+    response.set_response(b"...".to_vec());
+    test_round_trip(response);
+}