FileUtils: add method to get UUID of a volume

Change-Id: I41b76c5e01c82a2f8e67b33133a76947877a2814

3 files changed, 54 insertions, 1 deletions

diff --git a/core/java/android/os/FileUtils.java b/core/java/android/os/FileUtils.java
index 2bec1c1..f3f1725 100644
--- a/core/java/android/os/FileUtils.java
+++ b/core/java/android/os/FileUtils.java
@@ -54,6 +54,13 @@ public class FileUtils {
 
     public static native int setPermissions(String file, int mode, int uid, int gid);
 
+    /** returns the UUID for the volume mounted
+     * at the given mount point, or -1 for failure
+     * @param mountPoint point for volume
+     * @return UUID or -1
+     */
+    public static native int getVolumeUUID(String mountPoint);
+
     /** returns the FAT file system volume ID for the volume mounted 
      * at the given mount point, or -1 for failure
      * @param mountPoint point for FAT volume
diff --git a/core/jni/Android.mk b/core/jni/Android.mk
index c86f949..4ec9f33 100644
--- a/core/jni/Android.mk
+++ b/core/jni/Android.mk
@@ -165,7 +165,8 @@ LOCAL_C_INCLUDES += \
 	$(call include-path-for, bluedroid) \
 	$(call include-path-for, libhardware)/hardware \
 	$(call include-path-for, libhardware_legacy)/hardware_legacy \
- $(TOP)/frameworks/av/include \
+	$(TOP)/frameworks/av/include \
+ 	external/e2fsprogs/lib \
 	external/skia/include/core \
 	external/skia/include/effects \
 	external/skia/include/images \
@@ -189,6 +190,7 @@ LOCAL_C_INCLUDES += \
 LOCAL_SHARED_LIBRARIES := \
 	libandroidfw \
 	libexpat \
+	libext2_blkid \
 	libnativehelper \
 	libcutils \
 	libutils \
diff --git a/core/jni/android_os_FileUtils.cpp b/core/jni/android_os_FileUtils.cpp
index a07f5b7..b624a0d 100644
--- a/core/jni/android_os_FileUtils.cpp
+++ b/core/jni/android_os_FileUtils.cpp
@@ -23,6 +23,7 @@
 
 #include "JNIHelp.h"
 
+#include <string.h>
 #include <sys/errno.h>
 #include <sys/stat.h>
 #include <sys/types.h>
@@ -30,6 +31,7 @@
 #include <signal.h>
 #include <sys/ioctl.h>
 #include <linux/msdos_fs.h>
+#include <blkid/blkid.h>
 
 namespace android {
 
@@ -55,6 +57,47 @@ jint android_os_FileUtils_setPermissions(JNIEnv* env, jobject clazz,
     return chmod(file8.string(), mode) == 0 ? 0 : errno;
 }
 
+jint android_os_FileUtils_getVolumeUUID(JNIEnv* env, jobject clazz, jstring path)
+{
+    char *uuid = NULL;
+
+    if (path == NULL) {
+        jniThrowException(env, "java/lang/IllegalArgumentException", NULL);
+        return -1;
+    }
+
+    const char *pathStr = env->GetStringUTFChars(path, NULL);
+    ALOGD("Trying to get UUID for %s \n", pathStr);
+
+    uuid = blkid_get_tag_value(NULL, "UUID", pathStr);
+    if (uuid) {
+        ALOGD("UUID for %s is %s\n", pathStr, uuid);
+
+        String8 s8uuid = (String8)uuid;
+        size_t len = s8uuid.length();
+        String8 result;
+
+        if (len > 0) {
+            for (int i = 0; i > len; i++)
+            {
+                if (strncmp((const char *)s8uuid[i], (const char *)"-", 1) != 0) {
+                    result.append((const char *)s8uuid[i]);
+                }
+            }
+            len = 0;
+        }
+
+        len = result.length();
+
+        if (len > 0) {
+            return atoi(s8uuid);
+        } else {
+            ALOGE("Couldn't get UUID for %s\n", pathStr);
+        }
+    }
+    return -1;
+}
+
 jint android_os_FileUtils_getFatVolumeId(JNIEnv* env, jobject clazz, jstring path)
 {
     if (path == NULL) {
@@ -78,6 +121,7 @@ jint android_os_FileUtils_getFatVolumeId(JNIEnv* env, jobject clazz, jstring pat
 
 static const JNINativeMethod methods[] = {
     {"setPermissions",  "(Ljava/lang/String;III)I", (void*)android_os_FileUtils_setPermissions},
+    {"getVolumeUUID",  "(Ljava/lang/String;)I", (void*)android_os_FileUtils_getVolumeUUID},
     {"getFatVolumeId",  "(Ljava/lang/String;)I", (void*)android_os_FileUtils_getFatVolumeId},
 };