1 files changed, 239 insertions, 0 deletions
diff --git a/src/lib/nfs/Connection.hxx b/src/lib/nfs/Connection.hxx
new file mode 100644
index 000000000..3969a7e8f
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+++ b/src/lib/nfs/Connection.hxx
@@ -0,0 +1,239 @@
+/*
+ * Copyright (C) 2003-2014 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPD_NFS_CONNECTION_HXX
+#define MPD_NFS_CONNECTION_HXX
+
+#include "Lease.hxx"
+#include "Cancellable.hxx"
+#include "event/SocketMonitor.hxx"
+#include "event/TimeoutMonitor.hxx"
+#include "event/DeferredMonitor.hxx"
+#include "util/Error.hxx"
+
+#include <boost/intrusive/list.hpp>
+
+#include <string>
+#include <list>
+#include <forward_list>
+
+struct nfs_context;
+struct nfsdir;
+struct nfsdirent;
+class NfsCallback;
+
+/**
+ * An asynchronous connection to a NFS server.
+ */
+class NfsConnection : SocketMonitor, TimeoutMonitor, DeferredMonitor {
+	class CancellableCallback : public CancellablePointer<NfsCallback> {
+		NfsConnection &connection;
+
+		/**
+		 * Is this a nfs_open_async() operation?  If yes, then
+		 * we need to call nfs_close_async() on the new file
+		 * handle as soon as the callback is invoked
+		 * successfully.
+		 */
+		const bool open;
+
+		/**
+		 * The file handle scheduled to be closed as soon as
+		 * the operation finishes.
+		 */
+		struct nfsfh *close_fh;
+
+	public:
+		explicit CancellableCallback(NfsCallback &_callback,
+					     NfsConnection &_connection,
+					     bool _open)
+			:CancellablePointer<NfsCallback>(_callback),
+			 connection(_connection),
+			 open(_open), close_fh(nullptr) {}
+
+		bool Stat(nfs_context *context, const char *path,
+			  Error &error);
+		bool OpenDirectory(nfs_context *context, const char *path,
+				   Error &error);
+		bool Open(nfs_context *context, const char *path, int flags,
+			  Error &error);
+		bool Stat(nfs_context *context, struct nfsfh *fh,
+			  Error &error);
+		bool Read(nfs_context *context, struct nfsfh *fh,
+			  uint64_t offset, size_t size,
+			  Error &error);
+
+		/**
+		 * Cancel the operation and schedule a call to
+		 * nfs_close_async() with the given file handle.
+		 */
+		void CancelAndScheduleClose(struct nfsfh *fh);
+
+		/**
+		 * Called by NfsConnection::DestroyContext() right
+		 * before nfs_destroy_context().  This object is given
+		 * a chance to prepare for the latter.
+		 */
+		void PrepareDestroyContext();
+
+	private:
+		static void Callback(int err, struct nfs_context *nfs,
+				     void *data, void *private_data);
+		void Callback(int err, void *data);
+	};
+
+	std::string server, export_name;
+
+	nfs_context *context;
+
+	typedef std::list<NfsLease *> LeaseList;
+	LeaseList new_leases, active_leases;
+
+	typedef CancellableList<NfsCallback, CancellableCallback> CallbackList;
+	CallbackList callbacks;
+
+	/**
+	 * A list of NFS file handles (struct nfsfh *) which shall be
+	 * closed as soon as nfs_service() returns.  If we close the
+	 * file handle while in nfs_service(), libnfs may crash, and
+	 * deferring this call to after nfs_service() avoids this
+	 * problem.
+	 */
+	std::forward_list<struct nfsfh *> deferred_close;
+
+	Error postponed_mount_error;
+
+#ifndef NDEBUG
+	/**
+	 * True when nfs_service() is being called.
+	 */
+	bool in_service;
+
+	/**
+	 * True when OnSocketReady() is being called.  During that,
+	 * event updates are omitted.
+	 */
+	bool in_event;
+
+	/**
+	 * True when DestroyContext() is being called.
+	 */
+	bool in_destroy;
+#endif
+
+	bool mount_finished;
+
+public:
+	gcc_nonnull_all
+	NfsConnection(EventLoop &_loop,
+		      const char *_server, const char *_export_name)
+		:SocketMonitor(_loop), TimeoutMonitor(_loop),
+		 DeferredMonitor(_loop),
+		 server(_server), export_name(_export_name),
+		 context(nullptr) {}
+
+	/**
+	 * Must be run from EventLoop's thread.
+	 */
+	~NfsConnection();
+
+	gcc_pure
+	const char *GetServer() const {
+		return server.c_str();
+	}
+
+	gcc_pure
+	const char *GetExportName() const {
+		return export_name.c_str();
+	}
+
+	EventLoop &GetEventLoop() {
+		return SocketMonitor::GetEventLoop();
+	}
+
+	/**
+	 * Ensure that the connection is established.  The connection
+	 * is kept up while at least one #NfsLease is registered.
+	 *
+	 * This method is thread-safe.  However, #NfsLease's methods
+	 * will be invoked from within the #EventLoop's thread.
+	 */
+	void AddLease(NfsLease &lease);
+	void RemoveLease(NfsLease &lease);
+
+	bool Stat(const char *path, NfsCallback &callback, Error &error);
+
+	bool OpenDirectory(const char *path, NfsCallback &callback,
+			   Error &error);
+	const struct nfsdirent *ReadDirectory(struct nfsdir *dir);
+	void CloseDirectory(struct nfsdir *dir);
+
+	bool Open(const char *path, int flags, NfsCallback &callback,
+		  Error &error);
+	bool Stat(struct nfsfh *fh, NfsCallback &callback, Error &error);
+	bool Read(struct nfsfh *fh, uint64_t offset, size_t size,
+		  NfsCallback &callback, Error &error);
+	void Cancel(NfsCallback &callback);
+
+	void Close(struct nfsfh *fh);
+	void CancelAndClose(struct nfsfh *fh, NfsCallback &callback);
+
+protected:
+	virtual void OnNfsConnectionError(Error &&error) = 0;
+
+private:
+	void DestroyContext();
+
+	/**
+	 * Wrapper for nfs_close_async().
+	 */
+	void InternalClose(struct nfsfh *fh);
+
+	/**
+	 * Invoke nfs_close_async() after nfs_service() returns.
+	 */
+	void DeferClose(struct nfsfh *fh);
+
+	bool MountInternal(Error &error);
+	void BroadcastMountSuccess();
+	void BroadcastMountError(Error &&error);
+	void BroadcastError(Error &&error);
+
+	static void MountCallback(int status, nfs_context *nfs, void *data,
+				  void *private_data);
+	void MountCallback(int status, nfs_context *nfs, void *data);
+
+	void ScheduleSocket();
+
+	/**
+	 * Wrapper for nfs_service().
+	 */
+	int Service(unsigned flags);
+
+	/* virtual methods from SocketMonitor */
+	virtual bool OnSocketReady(unsigned flags) override;
+
+	/* virtual methods from TimeoutMonitor */
+	void OnTimeout() final;
+
+	/* virtual methods from DeferredMonitor */
+	virtual void RunDeferred() override;
+};
+
+#endif