Start paving the way for vold calls over Binder.
This change is the bare minimum needed to publish a new vold
Binder service and move the simple "reset" call over to go through
the new interface.
Test: builds, boots
Bug: 13758960
Change-Id: I5b70976653c69f92e1efc8d1f432b2038eb618a4
diff --git a/VoldNativeService.cpp b/VoldNativeService.cpp
new file mode 100644
index 0000000..2d55e14
--- /dev/null
+++ b/VoldNativeService.cpp
@@ -0,0 +1,116 @@
+/*
+ * Copyright (C) 2017 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.
+ */
+
+#include "VoldNativeService.h"
+#include "VolumeManager.h"
+
+#include <fstream>
+
+#include <android-base/logging.h>
+#include <android-base/stringprintf.h>
+#include <android-base/strings.h>
+#include <private/android_filesystem_config.h>
+
+#ifndef LOG_TAG
+#define LOG_TAG "vold"
+#endif
+
+using android::base::StringPrintf;
+using std::endl;
+
+namespace android {
+namespace vold {
+
+namespace {
+
+constexpr const char* kDump = "android.permission.DUMP";
+
+static binder::Status ok() {
+ return binder::Status::ok();
+}
+
+static binder::Status exception(uint32_t code, const std::string& msg) {
+ return binder::Status::fromExceptionCode(code, String8(msg.c_str()));
+}
+
+binder::Status checkPermission(const char* permission) {
+ pid_t pid;
+ uid_t uid;
+
+ if (checkCallingPermission(String16(permission), reinterpret_cast<int32_t*>(&pid),
+ reinterpret_cast<int32_t*>(&uid))) {
+ return ok();
+ } else {
+ return exception(binder::Status::EX_SECURITY,
+ StringPrintf("UID %d / PID %d lacks permission %s", uid, pid, permission));
+ }
+}
+
+binder::Status checkUid(uid_t expectedUid) {
+ uid_t uid = IPCThreadState::self()->getCallingUid();
+ if (uid == expectedUid || uid == AID_ROOT) {
+ return ok();
+ } else {
+ return exception(binder::Status::EX_SECURITY,
+ StringPrintf("UID %d is not expected UID %d", uid, expectedUid));
+ }
+}
+
+#define ENFORCE_UID(uid) { \
+ binder::Status status = checkUid((uid)); \
+ if (!status.isOk()) { \
+ return status; \
+ } \
+}
+
+} // namespace
+
+status_t VoldNativeService::start() {
+ IPCThreadState::self()->disableBackgroundScheduling(true);
+ status_t ret = BinderService<VoldNativeService>::publish();
+ if (ret != android::OK) {
+ return ret;
+ }
+ sp<ProcessState> ps(ProcessState::self());
+ ps->startThreadPool();
+ ps->giveThreadPoolName();
+ return android::OK;
+}
+
+status_t VoldNativeService::dump(int fd, const Vector<String16> & /* args */) {
+ auto out = std::fstream(StringPrintf("/proc/self/fd/%d", fd));
+ const binder::Status dump_permission = checkPermission(kDump);
+ if (!dump_permission.isOk()) {
+ out << dump_permission.toString8() << endl;
+ return PERMISSION_DENIED;
+ }
+
+ out << "vold is happy!" << endl;
+ out.flush();
+
+ return NO_ERROR;
+}
+
+binder::Status VoldNativeService::reset() {
+ ENFORCE_UID(AID_SYSTEM);
+
+ LOG(INFO) << "reset() via Binder!";
+ VolumeManager::Instance()->reset();
+ return ok();
+}
+
+} // namespace vold
+} // namespace android