1 files changed, 142 insertions, 0 deletions
diff --git a/fs_mgr/libsnapshot/snapuserd_server.h b/fs_mgr/libsnapshot/snapuserd_server.h
new file mode 100644
index 000000000..6699189ea
--- /dev/null
+++ b/fs_mgr/libsnapshot/snapuserd_server.h
@@ -0,0 +1,142 @@
+// Copyright (C) 2020 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.
+
+#pragma once
+
+#include <poll.h>
+
+#include <cstdio>
+#include <cstring>
+#include <functional>
+#include <future>
+#include <iostream>
+#include <mutex>
+#include <sstream>
+#include <string>
+#include <thread>
+#include <vector>
+
+#include <android-base/unique_fd.h>
+#include "snapuserd.h"
+
+namespace android {
+namespace snapshot {
+
+static constexpr uint32_t MAX_PACKET_SIZE = 512;
+
+enum class DaemonOperations {
+    INIT,
+    START,
+    QUERY,
+    STOP,
+    DELETE,
+    DETACH,
+    INVALID,
+};
+
+class DmUserHandler {
+  public:
+    explicit DmUserHandler(std::shared_ptr<Snapuserd> snapuserd);
+
+    void FreeResources() {
+        // Each worker thread holds a reference to snapuserd.
+        // Clear them so that all the resources
+        // held by snapuserd is released
+        if (snapuserd_) {
+            snapuserd_->FreeResources();
+            snapuserd_ = nullptr;
+        }
+    }
+    const std::shared_ptr<Snapuserd>& snapuserd() const { return snapuserd_; }
+    std::thread& thread() { return thread_; }
+
+    const std::string& misc_name() const { return misc_name_; }
+
+  private:
+    std::thread thread_;
+    std::shared_ptr<Snapuserd> snapuserd_;
+    std::string misc_name_;
+};
+
+class Stoppable {
+    std::promise<void> exitSignal_;
+    std::future<void> futureObj_;
+
+  public:
+    Stoppable() : futureObj_(exitSignal_.get_future()) {}
+
+    virtual ~Stoppable() {}
+
+    bool StopRequested() {
+        // checks if value in future object is available
+        if (futureObj_.wait_for(std::chrono::milliseconds(0)) == std::future_status::timeout) {
+            return false;
+        }
+        return true;
+    }
+    // Request the thread to stop by setting value in promise object
+    void StopThreads() { exitSignal_.set_value(); }
+};
+
+class SnapuserdServer : public Stoppable {
+  private:
+    android::base::unique_fd sockfd_;
+    bool terminating_;
+    std::vector<struct pollfd> watched_fds_;
+
+    std::mutex lock_;
+
+    using HandlerList = std::vector<std::shared_ptr<DmUserHandler>>;
+    HandlerList dm_users_;
+
+    void AddWatchedFd(android::base::borrowed_fd fd);
+    void AcceptClient();
+    bool HandleClient(android::base::borrowed_fd fd, int revents);
+    bool Recv(android::base::borrowed_fd fd, std::string* data);
+    bool Sendmsg(android::base::borrowed_fd fd, const std::string& msg);
+    bool Receivemsg(android::base::borrowed_fd fd, const std::string& str);
+
+    void ShutdownThreads();
+    bool RemoveAndJoinHandler(const std::string& control_device);
+    DaemonOperations Resolveop(std::string& input);
+    std::string GetDaemonStatus();
+    void Parsemsg(std::string const& msg, const char delim, std::vector<std::string>& out);
+
+    bool IsTerminating() { return terminating_; }
+
+    void RunThread(std::shared_ptr<DmUserHandler> handler);
+    void JoinAllThreads();
+
+    // Find a DmUserHandler within a lock.
+    HandlerList::iterator FindHandler(std::lock_guard<std::mutex>* proof_of_lock,
+                                      const std::string& misc_name);
+
+  public:
+    SnapuserdServer() { terminating_ = false; }
+    ~SnapuserdServer();
+
+    bool Start(const std::string& socketname);
+    bool Run();
+    void Interrupt();
+
+    std::shared_ptr<DmUserHandler> AddHandler(const std::string& misc_name,
+                                              const std::string& cow_device_path,
+                                              const std::string& backing_device);
+    bool StartHandler(const std::shared_ptr<DmUserHandler>& handler);
+
+    void SetTerminating() { terminating_ = true; }
+};
+
+}  // namespace snapshot
+}  // namespace android