diff --git a/otafault/ota_io.cpp b/otafault/ota_io.cpp
new file mode 100644
index 0000000..02e80f9
--- /dev/null
+++ b/otafault/ota_io.cpp
@@ -0,0 +1,160 @@
+/*
+ * 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.
+ */
+
+#if defined (TARGET_INJECT_FAULTS)
+#include <map>
+#endif
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "ota_io.h"
+
+#if defined (TARGET_INJECT_FAULTS)
+static std::map<int, const char*> FilenameCache;
+static std::string FaultFileName =
+#if defined (TARGET_READ_FAULT)
+        TARGET_READ_FAULT;
+#elif defined (TARGET_WRITE_FAULT)
+        TARGET_WRITE_FAULT;
+#elif defined (TARGET_FSYNC_FAULT)
+        TARGET_FSYNC_FAULT;
+#endif // defined (TARGET_READ_FAULT)
+#endif // defined (TARGET_INJECT_FAULTS)
+
+int ota_open(const char* path, int oflags) {
+#if defined (TARGET_INJECT_FAULTS)
+    // Let the caller handle errors; we do not care if open succeeds or fails
+    int fd = open(path, oflags);
+    FilenameCache[fd] = path;
+    return fd;
+#else
+    return open(path, oflags);
+#endif
+}
+
+int ota_open(const char* path, int oflags, mode_t mode) {
+#if defined (TARGET_INJECT_FAULTS)
+    int fd = open(path, oflags, mode);
+    FilenameCache[fd] = path;
+    return fd;
+#else
+    return open(path, oflags, mode);
+#endif
+}
+
+FILE* ota_fopen(const char* path, const char* mode) {
+#if defined (TARGET_INJECT_FAULTS)
+    FILE* fh = fopen(path, mode);
+    FilenameCache[(intptr_t)fh] = path;
+    return fh;
+#else
+    return fopen(path, mode);
+#endif
+}
+
+int ota_close(int fd) {
+#if defined (TARGET_INJECT_FAULTS)
+    // descriptors can be reused, so make sure not to leave them in the cahce
+    FilenameCache.erase(fd);
+#endif
+    return close(fd);
+}
+
+int ota_fclose(FILE* fh) {
+#if defined (TARGET_INJECT_FAULTS)
+    FilenameCache.erase((intptr_t)fh);
+#endif
+    return fclose(fh);
+}
+
+size_t ota_fread(void* ptr, size_t size, size_t nitems, FILE* stream) {
+#if defined (TARGET_READ_FAULT)
+    if (FilenameCache.find((intptr_t)stream) != FilenameCache.end()
+            && FilenameCache[(intptr_t)stream] == FaultFileName) {
+        FaultFileName = "";
+        errno = EIO;
+        return 0;
+    } else {
+        return fread(ptr, size, nitems, stream);
+    }
+#else
+    return fread(ptr, size, nitems, stream);
+#endif
+}
+
+ssize_t ota_read(int fd, void* buf, size_t nbyte) {
+#if defined (TARGET_READ_FAULT)
+    if (FilenameCache.find(fd) != FilenameCache.end()
+            && FilenameCache[fd] == FaultFileName) {
+        FaultFileName = "";
+        errno = EIO;
+        return -1;
+    } else {
+        return read(fd, buf, nbyte);
+    }
+#else
+    return read(fd, buf, nbyte);
+#endif
+}
+
+size_t ota_fwrite(const void* ptr, size_t size, size_t count, FILE* stream) {
+#if defined (TARGET_WRITE_FAULT)
+    if (FilenameCache.find((intptr_t)stream) != FilenameCache.end()
+            && FilenameCache[(intptr_t)stream] == FaultFileName) {
+        FaultFileName = "";
+        errno = EIO;
+        return 0;
+    } else {
+        return fwrite(ptr, size, count, stream);
+    }
+#else
+    return fwrite(ptr, size, count, stream);
+#endif
+}
+
+ssize_t ota_write(int fd, const void* buf, size_t nbyte) {
+#if defined (TARGET_WRITE_FAULT)
+    if (FilenameCache.find(fd) != FilenameCache.end()
+            && FilenameCache[fd] == FaultFileName) {
+        FaultFileName = "";
+        errno = EIO;
+        return -1;
+    } else {
+        return write(fd, buf, nbyte);
+    }
+#else
+    return write(fd, buf, nbyte);
+#endif
+}
+
+int ota_fsync(int fd) {
+#if defined (TARGET_FSYNC_FAULT)
+    if (FilenameCache.find(fd) != FilenameCache.end()
+            && FilenameCache[fd] == FaultFileName) {
+        FaultFileName = "";
+        errno = EIO;
+        return -1;
+    } else {
+        return fsync(fd);
+    }
+#else
+    return fsync(fd);
+#endif
+}