1 files changed, 423 insertions, 0 deletions
diff --git a/src/storage/plugins/NfsStorage.cxx b/src/storage/plugins/NfsStorage.cxx
new file mode 100644
index 000000000..324b40b6f
--- /dev/null
+++ b/src/storage/plugins/NfsStorage.cxx
@@ -0,0 +1,423 @@
+/*
+ * 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.
+ */
+
+#include "config.h"
+#include "NfsStorage.hxx"
+#include "storage/StoragePlugin.hxx"
+#include "storage/StorageInterface.hxx"
+#include "storage/FileInfo.hxx"
+#include "storage/MemoryDirectoryReader.hxx"
+#include "lib/nfs/Blocking.hxx"
+#include "lib/nfs/Domain.hxx"
+#include "lib/nfs/Base.hxx"
+#include "lib/nfs/Lease.hxx"
+#include "lib/nfs/Connection.hxx"
+#include "lib/nfs/Glue.hxx"
+#include "fs/AllocatedPath.hxx"
+#include "util/Error.hxx"
+#include "thread/Mutex.hxx"
+#include "thread/Cond.hxx"
+#include "event/Loop.hxx"
+#include "event/Call.hxx"
+#include "event/DeferredMonitor.hxx"
+#include "event/TimeoutMonitor.hxx"
+
+extern "C" {
+#include <nfsc/libnfs.h>
+#include <nfsc/libnfs-raw-nfs.h>
+}
+
+#include <string>
+
+#include <assert.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+class NfsStorage final
+	: public Storage, NfsLease, DeferredMonitor, TimeoutMonitor {
+
+	enum class State {
+		INITIAL, CONNECTING, READY, DELAY,
+	};
+
+	const std::string base;
+
+	const std::string server, export_name;
+
+	NfsConnection *connection;
+
+	Mutex mutex;
+	Cond cond;
+	State state;
+	Error last_error;
+
+public:
+	NfsStorage(EventLoop &_loop, const char *_base,
+		   std::string &&_server, std::string &&_export_name)
+		:DeferredMonitor(_loop), TimeoutMonitor(_loop),
+		 base(_base),
+		 server(std::move(_server)),
+		 export_name(std::move(_export_name)),
+		 state(State::INITIAL) {
+		nfs_init();
+	}
+
+	~NfsStorage() {
+		BlockingCall(GetEventLoop(), [this](){ Disconnect(); });
+		nfs_finish();
+	}
+
+	/* virtual methods from class Storage */
+	bool GetInfo(const char *uri_utf8, bool follow, FileInfo &info,
+		     Error &error) override;
+
+	StorageDirectoryReader *OpenDirectory(const char *uri_utf8,
+					      Error &error) override;
+
+	std::string MapUTF8(const char *uri_utf8) const override;
+
+	const char *MapToRelativeUTF8(const char *uri_utf8) const override;
+
+	/* virtual methods from NfsLease */
+	void OnNfsConnectionReady() final {
+		assert(state == State::CONNECTING);
+
+		SetState(State::READY);
+	}
+
+	void OnNfsConnectionFailed(gcc_unused const Error &error) final {
+		assert(state == State::CONNECTING);
+
+		SetState(State::DELAY, error);
+		TimeoutMonitor::ScheduleSeconds(60);
+	}
+
+	void OnNfsConnectionDisconnected(gcc_unused const Error &error) final {
+		assert(state == State::READY);
+
+		SetState(State::DELAY, error);
+		TimeoutMonitor::ScheduleSeconds(5);
+	}
+
+	/* virtual methods from DeferredMonitor */
+	void RunDeferred() final {
+		if (state == State::INITIAL)
+			Connect();
+	}
+
+	/* virtual methods from TimeoutMonitor */
+	void OnTimeout() final {
+		assert(state == State::DELAY);
+
+		Connect();
+	}
+
+private:
+	EventLoop &GetEventLoop() {
+		return DeferredMonitor::GetEventLoop();
+	}
+
+	void SetState(State _state) {
+		assert(GetEventLoop().IsInside());
+
+		const ScopeLock protect(mutex);
+		state = _state;
+		cond.broadcast();
+	}
+
+	void SetState(State _state, const Error &error) {
+		assert(GetEventLoop().IsInside());
+
+		const ScopeLock protect(mutex);
+		state = _state;
+		last_error.Clear();
+		last_error.Set(error);
+		cond.broadcast();
+	}
+
+	void Connect() {
+		assert(state != State::READY);
+		assert(GetEventLoop().IsInside());
+
+		connection = &nfs_get_connection(server.c_str(),
+						 export_name.c_str());
+		connection->AddLease(*this);
+
+		SetState(State::CONNECTING);
+	}
+
+	void EnsureConnected() {
+		if (state != State::READY)
+			Connect();
+	}
+
+	bool WaitConnected(Error &error) {
+		const ScopeLock protect(mutex);
+
+		while (true) {
+			switch (state) {
+			case State::INITIAL:
+				/* schedule connect */
+				mutex.unlock();
+				DeferredMonitor::Schedule();
+				mutex.lock();
+				break;
+
+			case State::CONNECTING:
+			case State::READY:
+				return true;
+
+			case State::DELAY:
+				assert(last_error.IsDefined());
+				error.Set(last_error);
+				return false;
+			}
+
+			cond.wait(mutex);
+		}
+	}
+
+	void Disconnect() {
+		assert(GetEventLoop().IsInside());
+
+		switch (state) {
+		case State::INITIAL:
+			DeferredMonitor::Cancel();
+			break;
+
+		case State::CONNECTING:
+		case State::READY:
+			connection->RemoveLease(*this);
+			SetState(State::INITIAL);
+			break;
+
+		case State::DELAY:
+			TimeoutMonitor::Cancel();
+			SetState(State::INITIAL);
+			break;
+		}
+	}
+};
+
+static std::string
+UriToNfsPath(const char *_uri_utf8, Error &error)
+{
+	assert(_uri_utf8 != nullptr);
+
+	/* libnfs paths must begin with a slash */
+	std::string uri_utf8("/");
+	uri_utf8.append(_uri_utf8);
+
+	return AllocatedPath::FromUTF8(uri_utf8.c_str(), error).Steal();
+}
+
+std::string
+NfsStorage::MapUTF8(const char *uri_utf8) const
+{
+	assert(uri_utf8 != nullptr);
+
+	if (*uri_utf8 == 0)
+		return base;
+
+	return PathTraitsUTF8::Build(base.c_str(), uri_utf8);
+}
+
+const char *
+NfsStorage::MapToRelativeUTF8(const char *uri_utf8) const
+{
+	return PathTraitsUTF8::Relative(base.c_str(), uri_utf8);
+}
+
+static void
+Copy(FileInfo &info, const struct stat &st)
+{
+	if (S_ISREG(st.st_mode))
+		info.type = FileInfo::Type::REGULAR;
+	else if (S_ISDIR(st.st_mode))
+		info.type = FileInfo::Type::DIRECTORY;
+	else
+		info.type = FileInfo::Type::OTHER;
+
+	info.size = st.st_size;
+	info.mtime = st.st_mtime;
+	info.device = st.st_dev;
+	info.inode = st.st_ino;
+}
+
+class NfsGetInfoOperation final : public BlockingNfsOperation {
+	const char *const path;
+	FileInfo &info;
+
+public:
+	NfsGetInfoOperation(NfsConnection &_connection, const char *_path,
+			    FileInfo &_info)
+		:BlockingNfsOperation(_connection), path(_path), info(_info) {}
+
+protected:
+	bool Start(Error &_error) override {
+		return connection.Stat(path, *this, _error);
+	}
+
+	void HandleResult(gcc_unused unsigned status, void *data) override {
+		Copy(info, *(const struct stat *)data);
+	}
+};
+
+bool
+NfsStorage::GetInfo(const char *uri_utf8, gcc_unused bool follow,
+		    FileInfo &info, Error &error)
+{
+	const std::string path = UriToNfsPath(uri_utf8, error);
+	if (path.empty())
+		return false;
+
+	if (!WaitConnected(error))
+		return false;
+
+	NfsGetInfoOperation operation(*connection, path.c_str(), info);
+	return operation.Run(error);
+}
+
+gcc_pure
+static bool
+SkipNameFS(const char *name)
+{
+	return name[0] == '.' &&
+		(name[1] == 0 ||
+		 (name[1] == '.' && name[2] == 0));
+}
+
+static void
+Copy(FileInfo &info, const struct nfsdirent &ent)
+{
+	switch (ent.type) {
+	case NF3REG:
+		info.type = FileInfo::Type::REGULAR;
+		break;
+
+	case NF3DIR:
+		info.type = FileInfo::Type::DIRECTORY;
+		break;
+
+	default:
+		info.type = FileInfo::Type::OTHER;
+		break;
+	}
+
+	info.size = ent.size;
+	info.mtime = ent.mtime.tv_sec;
+	info.device = 0;
+	info.inode = ent.inode;
+}
+
+class NfsListDirectoryOperation final : public BlockingNfsOperation {
+	const char *const path;
+
+	MemoryStorageDirectoryReader::List entries;
+
+public:
+	NfsListDirectoryOperation(NfsConnection &_connection,
+				  const char *_path)
+		:BlockingNfsOperation(_connection), path(_path) {}
+
+	StorageDirectoryReader *ToReader() {
+		return new MemoryStorageDirectoryReader(std::move(entries));
+	}
+
+protected:
+	bool Start(Error &_error) override {
+		return connection.OpenDirectory(path, *this, _error);
+	}
+
+	void HandleResult(gcc_unused unsigned status, void *data) override {
+		struct nfsdir *const dir = (struct nfsdir *)data;
+
+		CollectEntries(dir);
+		connection.CloseDirectory(dir);
+	}
+
+private:
+	void CollectEntries(struct nfsdir *dir);
+};
+
+inline void
+NfsListDirectoryOperation::CollectEntries(struct nfsdir *dir)
+{
+	assert(entries.empty());
+
+	const struct nfsdirent *ent;
+	while ((ent = connection.ReadDirectory(dir)) != nullptr) {
+		const Path name_fs = Path::FromFS(ent->name);
+		if (SkipNameFS(name_fs.c_str()))
+			continue;
+
+		std::string name_utf8 = name_fs.ToUTF8();
+		if (name_utf8.empty())
+			/* ignore files whose name cannot be converted
+			   to UTF-8 */
+			continue;
+
+		entries.emplace_front(std::move(name_utf8));
+		Copy(entries.front().info, *ent);
+	}
+}
+
+StorageDirectoryReader *
+NfsStorage::OpenDirectory(const char *uri_utf8, Error &error)
+{
+	const std::string path = UriToNfsPath(uri_utf8, error);
+	if (path.empty())
+		return nullptr;
+
+	if (!WaitConnected(error))
+		return nullptr;
+
+	NfsListDirectoryOperation operation(*connection, path.c_str());
+	if (!operation.Run(error))
+		return nullptr;
+
+	return operation.ToReader();
+}
+
+static Storage *
+CreateNfsStorageURI(EventLoop &event_loop, const char *base,
+		    Error &error)
+{
+	if (memcmp(base, "nfs://", 6) != 0)
+		return nullptr;
+
+	const char *p = base + 6;
+
+	const char *mount = strchr(p, '/');
+	if (mount == nullptr) {
+		error.Set(nfs_domain, "Malformed nfs:// URI");
+		return nullptr;
+	}
+
+	const std::string server(p, mount);
+
+	nfs_set_base(server.c_str(), mount);
+
+	return new NfsStorage(event_loop, base, server.c_str(), mount);
+}
+
+const StoragePlugin nfs_storage_plugin = {
+	"nfs",
+	CreateNfsStorageURI,
+};