Merge "Add a hidden API for fgetfilecon(3)"

am: 9b04b2fd0b

Change-Id: Ic1f623ec3fd4b1e1b65840d2c2ded47b61554520

core/java/android/os/SELinux.java

@@ -18,9 +18,9 @@ package android.os;
 
 import android.util.Slog;
 
-import java.io.IOException;
 import java.io.File;
 import java.io.FileDescriptor;
+import java.io.IOException;
 
 /**
  * This class provides access to the centralized jni bindings for
@@ -78,6 +78,13 @@ public class SELinux {
      */
     public static final native String getPeerContext(FileDescriptor fd);
 
+    /**
+     * Get the security context of a file descriptor of a file.
+     * @param fd FileDescriptor of a file.
+     * @return a String representing the file descriptor security context.
+     */
+    public static final native String getFileContext(FileDescriptor fd);
+
     /**
      * Gets the security context of the current process.
      * @return a String representing the security context of the current process.

core/java/com/android/internal/os/BatteryStatsHelper.java

@@ -31,6 +31,7 @@ import android.os.Parcel;
 import android.os.ParcelFileDescriptor;
 import android.os.Process;
 import android.os.RemoteException;
+import android.os.SELinux;
 import android.os.ServiceManager;
 import android.os.SystemClock;
 import android.os.UserHandle;
@@ -1031,6 +1032,10 @@ public class BatteryStatsHelper {
         try {
             ParcelFileDescriptor pfd = service.getStatisticsStream();
             if (pfd != null) {
+                if (false) {
+                    Log.d(TAG, "selinux context: "
+                            + SELinux.getFileContext(pfd.getFileDescriptor()));
+                }
                 try (FileInputStream fis = new ParcelFileDescriptor.AutoCloseInputStream(pfd)) {
                     byte[] data = readFully(fis, MemoryFile.getSize(pfd.getFileDescriptor()));
                     Parcel parcel = Parcel.obtain();

core/jni/android_os_SELinux.cpp

@@ -60,6 +60,41 @@ static jboolean isSELinuxEnforced(JNIEnv *env, jobject) {
     return (security_getenforce() == 1) ? true : false;
 }
 
+static jstring getFdConInner(JNIEnv *env, jobject fileDescriptor, bool isSocket) {
+    if (isSELinuxDisabled) {
+        return NULL;
+    }
+
+    if (fileDescriptor == NULL) {
+        jniThrowNullPointerException(env,
+                "Trying to check security context of a null FileDescriptor.");
+        return NULL;
+    }
+
+    int fd = jniGetFDFromFileDescriptor(env, fileDescriptor);
+    if (env->ExceptionCheck()) {
+        ALOGE("getFdCon => getFD for %p failed", fileDescriptor);
+        return NULL;
+    }
+
+    security_context_t tmp = NULL;
+    int ret;
+    if (isSocket) {
+        ret = getpeercon(fd, &tmp);
+    } else{
+        ret = fgetfilecon(fd, &tmp);
+    }
+    Unique_SecurityContext context(tmp);
+
+    ScopedLocalRef<jstring> contextStr(env, NULL);
+    if (ret != -1) {
+        contextStr.reset(env->NewStringUTF(context.get()));
+    }
+
+    ALOGV("getFdCon(%d) => %s", fd, context.get());
+    return contextStr.release();
+}
+
 /*
  * Function: getPeerCon
  * Purpose: retrieves security context of peer socket
@@ -69,33 +104,19 @@ static jboolean isSELinuxEnforced(JNIEnv *env, jobject) {
  * Exceptions: NullPointerException if fileDescriptor object is NULL
  */
 static jstring getPeerCon(JNIEnv *env, jobject, jobject fileDescriptor) {
-    if (isSELinuxDisabled) {
+    return getFdConInner(env, fileDescriptor, true);
-        return NULL;
+}
-    }
 
-    if (fileDescriptor == NULL) {
+/*
-        jniThrowNullPointerException(env,
+ * Function: getFdCon
-                "Trying to check security context of a null peer socket.");
+ * Purpose: retrieves security context of a file descriptor.
-        return NULL;
+ * Parameters:
-    }
+ *        fileDescriptor: a FileDescriptor object
-
+ * Returns: jstring representing the security_context of socket or NULL if error
-    int fd = jniGetFDFromFileDescriptor(env, fileDescriptor);
+ * Exceptions: NullPointerException if fileDescriptor object is NULL
-    if (env->ExceptionCheck()) {
+ */
-        ALOGE("getPeerCon => getFD for %p failed", fileDescriptor);
+static jstring getFdCon(JNIEnv *env, jobject, jobject fileDescriptor) {
-        return NULL;
+    return getFdConInner(env, fileDescriptor, false);
-    }
-
-    security_context_t tmp = NULL;
-    int ret = getpeercon(fd, &tmp);
-    Unique_SecurityContext context(tmp);
-
-    ScopedLocalRef<jstring> contextStr(env, NULL);
-    if (ret != -1) {
-        contextStr.reset(env->NewStringUTF(context.get()));
-    }
-
-    ALOGV("getPeerCon(%d) => %s", fd, context.get());
-    return contextStr.release();
 }
 
 /*
@@ -326,6 +347,7 @@ static const JNINativeMethod method_table[] = {
     { "getContext"               , "()Ljava/lang/String;"                         , (void*)getCon           },
     { "getFileContext"           , "(Ljava/lang/String;)Ljava/lang/String;"       , (void*)getFileCon       },
     { "getPeerContext"           , "(Ljava/io/FileDescriptor;)Ljava/lang/String;" , (void*)getPeerCon       },
+    { "getFileContext"           , "(Ljava/io/FileDescriptor;)Ljava/lang/String;" , (void*)getFdCon         },
     { "getPidContext"            , "(I)Ljava/lang/String;"                        , (void*)getPidCon        },
     { "isSELinuxEnforced"        , "()Z"                                          , (void*)isSELinuxEnforced},
     { "isSELinuxEnabled"         , "()Z"                                          , (void*)isSELinuxEnabled },