Control fault injection with config files instead of build flags

Bug: 26570379
Change-Id: I76109d09276d6e3ed3a32b6fedafb2582f545c0c
(cherry picked from commit d940887dde23597dc358b16d96ca48dd7480fee6)
diff --git a/otafault/config.h b/otafault/config.h
new file mode 100644
index 0000000..4430be3
--- /dev/null
+++ b/otafault/config.h
@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+ * Read configuration files in the OTA package to determine which files, if any, will trigger errors.
+ *
+ * OTA packages can be modified to trigger errors by adding a top-level
+ * directory called .libotafault, which may optionally contain up to three
+ * files called READ, WRITE, and FSYNC. Each one of these optional files
+ * contains the name of a single file on the device disk which will cause
+ * an IO error on the first call of the appropriate I/O action to that file.
+ *
+ * Example:
+ * ota.zip
+ *   <normal package contents>
+ *   .libotafault
+ *     WRITE
+ *
+ * If the contents of the file WRITE were /system/build.prop, the first write
+ * action to /system/build.prop would fail with EIO. Note that READ and
+ * FSYNC files are absent, so these actions will not cause an error.
+ */
+
+#ifndef _UPDATER_OTA_IO_CFG_H_
+#define _UPDATER_OTA_IO_CFG_H_
+
+#include <string>
+
+#include <stdbool.h>
+
+#include "minzip/Zip.h"
+
+#define OTAIO_BASE_DIR ".libotafault"
+#define OTAIO_READ "READ"
+#define OTAIO_WRITE "WRITE"
+#define OTAIO_FSYNC "FSYNC"
+#define OTAIO_CACHE "CACHE"
+
+/*
+ * Initialize libotafault by providing a reference to the OTA package.
+ */
+void ota_io_init(ZipArchive* za);
+
+/*
+ * Return true if a config file is present for the given IO type.
+ */
+bool should_fault_inject(const char* io_type);
+
+/*
+ * Return true if an EIO should occur on the next hit to /cache/saved.file
+ * instead of the next hit to the specified file.
+ */
+bool should_hit_cache();
+
+/*
+ * Return the name of the file that should cause an error for the
+ * given IO type.
+ */
+std::string fault_fname(const char* io_type);
+
+#endif