Allow uncrypt to work without socket communication

It was inconvenient to uncrypt a update package under adb shell
because the uncrypt executable required a socket to start its job.
Add a workaround to allow uncrypt executes without socket
communication.

Test: run uncrypt under adb shell, and the block map generates successfully
Bug: 29906218

Change-Id: Ibc328b31636d925dc429ede8dcec7392a721dd53
diff --git a/uncrypt/uncrypt.cpp b/uncrypt/uncrypt.cpp
index c19943f..ba45946 100644
--- a/uncrypt/uncrypt.cpp
+++ b/uncrypt/uncrypt.cpp
@@ -210,6 +210,11 @@
 }
 
 static bool write_status_to_socket(int status, int socket) {
+    // If socket equals -1, uncrypt is in debug mode without socket communication.
+    // Skip writing and return success.
+    if (socket == -1) {
+        return true;
+    }
     int status_out = htonl(status);
     return android::base::WriteFully(socket, &status_out, sizeof(int));
 }
@@ -539,7 +544,7 @@
 }
 
 int main(int argc, char** argv) {
-    enum { UNCRYPT, SETUP_BCB, CLEAR_BCB } action;
+    enum { UNCRYPT, SETUP_BCB, CLEAR_BCB, UNCRYPT_DEBUG } action;
     const char* input_path = nullptr;
     const char* map_file = CACHE_BLOCK_MAP.c_str();
 
@@ -552,7 +557,7 @@
     } else if (argc == 3) {
         input_path = argv[1];
         map_file = argv[2];
-        action = UNCRYPT;
+        action = UNCRYPT_DEBUG;
     } else {
         usage(argv[0]);
         return 2;
@@ -562,6 +567,17 @@
         return 1;
     }
 
+    if (action == UNCRYPT_DEBUG) {
+        ALOGI("uncrypt called in debug mode, skip socket communication\n");
+        bool success = uncrypt_wrapper(input_path, map_file, -1);
+        if (success) {
+            ALOGI("uncrypt succeeded\n");
+        } else{
+            ALOGI("uncrypt failed\n");
+        }
+        return success ? 0 : 1;
+    }
+
     // c3. The socket is created by init when starting the service. uncrypt
     // will use the socket to communicate with its caller.
     android::base::unique_fd service_socket(android_get_control_socket(UNCRYPT_SOCKET.c_str()));