Use cras-config-dir instead of ucm-suffix for beamforming

Eventually we should have config files for beamforming,
before that let's just not (ab)use ucm as a config
side channel.

BUG=b:327062210
BUG=b:233174542
BUG=b:339785214
TEST=dbus-send --system --print-reply --dest=org.chromium.cras /org/chromium/cras org.chromium.cras.Control.DumpS2AsJSON

Change-Id: I2ba4a90e1256dfa2569cd8c28a1645086a1e6561
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/adhd/+/5528486
Commit-Queue: Li-Yu Yu <aaronyu@google.com>
Tested-by: chromeos-cop-builder@chromeos-cop.iam.gserviceaccount.com <chromeos-cop-builder@chromeos-cop.iam.gserviceaccount.com>
Reviewed-by: Chih-Yang Hsia <paulhsia@chromium.org>

5 files changed, 21 insertions, 23 deletions

diff --git a/cras/server/s2/s2.h b/cras/server/s2/s2.h
index e2699637..120ad9a3 100644
--- a/cras/server/s2/s2.h
+++ b/cras/server/s2/s2.h
@@ -34,7 +34,7 @@ void cras_s2_set_style_transfer_enabled(bool enabled);
 
 bool cras_s2_get_style_transfer_enabled(void);
 
-void cras_s2_set_ucm_suffix(const char *ucm_suffix);
+void cras_s2_load_cras_config_dir(void);
 
 bool cras_s2_get_beamforming_supported(void);
 
diff --git a/cras/server/s2/src/global.rs b/cras/server/s2/src/global.rs
index e35474d9..028c3a78 100644
--- a/cras/server/s2/src/global.rs
+++ b/cras/server/s2/src/global.rs
@@ -3,7 +3,6 @@
 // found in the LICENSE file.
 
 use std::ffi::c_char;
-use std::ffi::CStr;
 use std::ffi::CString;
 use std::ops::Deref;
 use std::sync::Mutex;
@@ -62,18 +61,14 @@ pub extern "C" fn cras_s2_get_style_transfer_enabled() -> bool {
 }
 
 #[no_mangle]
-pub unsafe extern "C" fn cras_s2_set_ucm_suffix(ucm_suffix: *const libc::c_char) {
-    if ucm_suffix.is_null() {
-        state().set_ucm_suffix("");
-    } else {
-        match CStr::from_ptr(ucm_suffix).to_str() {
-            Ok(str) => {
-                state().set_ucm_suffix(str);
-            }
-            Err(err) => {
-                state().set_ucm_suffix("");
-                log::error!("ucm_suffix is not a valid string: {err}");
-            }
+pub extern "C" fn cras_s2_load_cras_config_dir() {
+    match std::fs::read_to_string("/run/chromeos-config/v1/audio/main/cras-config-dir") {
+        Ok(str) => {
+            state().set_cras_config_dir(&str);
+        }
+        Err(err) => {
+            state().set_cras_config_dir("");
+            log::info!("Failed to read cras-config-dir: {err}");
         }
     }
 }
diff --git a/cras/server/s2/src/lib.rs b/cras/server/s2/src/lib.rs
index beb21559..9b8b8383 100644
--- a/cras/server/s2/src/lib.rs
+++ b/cras/server/s2/src/lib.rs
@@ -16,8 +16,8 @@ struct Input {
     dlc_manager_ready: bool,
     style_transfer_featured_allowed: bool,
     style_transfer_enabled: bool,
-    // cros_config /audio/main ucm-suffix.
-    ucm_suffix: String,
+    // cros_config /audio/main cras-config-dir.
+    cras_config_dir: String,
 }
 
 #[derive(Serialize)]
@@ -29,7 +29,8 @@ struct Output {
 }
 
 fn resolve(input: &Input) -> Output {
-    let beamforming_supported = input.ucm_suffix == "omniknight.3mic";
+    // TODO(b/339785214): Decide this based on config file content.
+    let beamforming_supported = input.cras_config_dir == "omniknight.3mic";
     Output {
         ap_nc_allowed: input.ap_nc_featured_allowed
             || input.ap_nc_segmentation_allowed
@@ -62,7 +63,7 @@ impl S2 {
             dlc_manager_ready: false,
             style_transfer_featured_allowed: false,
             style_transfer_enabled: false,
-            ucm_suffix: String::new(),
+            cras_config_dir: String::new(),
         };
         let output = resolve(&input);
         Self { input, output }
@@ -98,8 +99,8 @@ impl S2 {
         self.update();
     }
 
-    fn set_ucm_suffix(&mut self, ucm_suffix: &str) {
-        self.input.ucm_suffix = ucm_suffix.into();
+    fn set_cras_config_dir(&mut self, cras_config_dir: &str) {
+        self.input.cras_config_dir = cras_config_dir.into();
         self.update();
     }
 
@@ -169,11 +170,11 @@ mod tests {
         assert!(!s.output.beamforming_supported);
         assert!(s.output.style_transfer_supported);
 
-        s.set_ucm_suffix("omniknight.3mic");
+        s.set_cras_config_dir("omniknight.3mic");
         assert!(s.output.beamforming_supported);
         assert!(!s.output.style_transfer_supported);
 
-        s.set_ucm_suffix("omniknight");
+        s.set_cras_config_dir("omniknight");
         assert!(!s.output.beamforming_supported);
         assert!(s.output.style_transfer_supported);
     }
diff --git a/cras/src/server/cras_system_state.c b/cras/src/server/cras_system_state.c
index da2390bf..205bb73d 100644
--- a/cras/src/server/cras_system_state.c
+++ b/cras/src/server/cras_system_state.c
@@ -2,6 +2,7 @@
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
+
 #include "cras/src/server/cras_system_state.h"
 
 #include <errno.h>
@@ -209,6 +210,7 @@ void cras_system_state_init(const char* device_config_dir,
     syslog(LOG_ERR, "Fatal: no memory to create board config");
     exit(-ENOMEM);
   }
+  cras_s2_load_cras_config_dir();
 
   // Initial system state.
   exp_state->state_version = CRAS_SERVER_STATE_VERSION;
@@ -317,7 +319,6 @@ void cras_system_state_deinit() {
 void cras_system_state_set_internal_ucm_suffix(
     const char* internal_ucm_suffix) {
   state.internal_ucm_suffix = internal_ucm_suffix;
-  cras_s2_set_ucm_suffix(internal_ucm_suffix);
 }
 
 void cras_system_set_volume(size_t volume) {
diff --git a/init/cras.sh b/init/cras.sh
index ab8ee52e..116cf3f2 100644
--- a/init/cras.sh
+++ b/init/cras.sh
@@ -18,6 +18,7 @@ exec minijail0 -u cras -g cras -G --uts -v -l \
         -k '/run/imageloader,/run/imageloader,none,MS_BIND|MS_REC' \
         -b /run/libsegmentation \
         -b /run/udev \
+        -b /run/chromeos-config/v1 \
         -b /dev \
         -b /dev/shm,,1 \
         -k proc,/proc,proc \