Add a flag that makes dumpstate wait for options

There are 2 ways of running bugreports. Running dumpstate binary
directly with command line options (existing flow), or running the
binary to start the binder service, which waits for a caller to supply
arguments like file descriptors to write output to (new flow to support
the bugreport triggering API).

Support the second flow with a new commandline flag.

Also add a new service that uses the flag, to be used in the API.

BUG:111441001
Test: adb shell setprop "ctl.start" "bugreportd" -> starts service &
waits.
Test: interactive bugreport still works
Change-Id: I64cd03d15f45a896692d7462998d4faa6e413ef1
diff --git a/cmds/dumpstate/main.cpp b/cmds/dumpstate/main.cpp
index 78aad11..68d3733 100644
--- a/cmds/dumpstate/main.cpp
+++ b/cmds/dumpstate/main.cpp
@@ -14,8 +14,55 @@
  * limitations under the License.
  */
 
+#define LOG_TAG "dumpstate"
+
+#include <binder/IPCThreadState.h>
+
+#include "DumpstateInternal.h"
+#include "DumpstateService.h"
 #include "dumpstate.h"
 
+namespace {
+
+// Returns true if we should start the service and wait for a listener
+// to bind with bugreport options.
+bool ShouldStartServiceAndWait(int argc, char* argv[]) {
+    bool do_wait = false;
+    int c;
+    // Keep flags in sync with Dumpstate::DumpOptions::Initialize.
+    while ((c = getopt(argc, argv, "wdho:svqzpPBRSV:")) != -1 && !do_wait) {
+        switch (c) {
+            case 'w':
+                do_wait = true;
+                break;
+            default:
+                // Ignore all other options
+                break;
+        }
+    }
+
+    // Reset next index used by getopt so getopt can be called called again in Dumpstate::Run to
+    // parse bugreport options.
+    optind = 1;
+    return do_wait;
+}
+
+}  // namespace
+
 int main(int argc, char* argv[]) {
-    return run_main(argc, argv);
+    if (ShouldStartServiceAndWait(argc, argv)) {
+        int ret;
+        if ((ret = android::os::DumpstateService::Start()) != android::OK) {
+            MYLOGE("Unable to start 'dumpstate' service: %d", ret);
+            exit(1);
+        }
+        MYLOGI("'dumpstate' service started and will wait for a call to startBugreport()");
+
+        // Waits forever for an incoming connection.
+        // TODO(b/111441001): should this time out?
+        android::IPCThreadState::self()->joinThreadPool();
+        return 0;
+    } else {
+        return run_main(argc, argv);
+    }
 }