Separate out JSON store from controller code.

2 files changed, 234 insertions, 0 deletions

diff --git a/controller/JSONDB.cpp b/controller/JSONDB.cpp
new file mode 100644
index 00000000..40bc21ac
--- /dev/null
+++ b/controller/JSONDB.cpp
@@ -0,0 +1,146 @@
+/*
+ * ZeroTier One - Network Virtualization Everywhere
+ * Copyright (C) 2011-2015  ZeroTier, Inc.
+ *
+ * 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 3 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "JSONDB.hpp"
+
+namespace ZeroTier {
+
+static const nlohmann::json _EMPTY_JSON({{}});
+
+bool JSONDB::put(const std::string &n,const nlohmann::json &obj)
+{
+	if (!_isValidObjectName(n))
+		return false;
+
+	std::string path(_genPath(n,false));
+	if (!path.length())
+		return false;
+
+	std::string buf(obj.dump(2));
+	if (!OSUtils::writeFile(path.c_str(),buf))
+		return false;
+
+	_E &e = _db[n];
+
+	e.lastModifiedOnDisk = OSUtils::getLastModified(path.c_str());
+	e.lastCheck = OSUtils::now();
+	e.obj = obj;
+
+	return true;
+}
+
+const nlohmann::json &JSONDB::get(const std::string &n,unsigned long maxSinceCheck)
+{
+	if (!_isValidObjectName(n))
+		return _EMPTY_JSON;
+
+	const uint64_t now = OSUtils::now();
+	std::string buf;
+	std::map<std::string,_E>::iterator e(_db.find(n));
+
+	if (e != _db.end()) {
+		if ((now - e->second.lastCheck) <= (uint64_t)maxSinceCheck)
+			return e->second.obj;
+
+		std::string path(_genPath(n,false));
+		if (!path.length()) // sanity check
+			return _EMPTY_JSON;
+
+		// We are somewhat tolerant to momentary disk failures here. This may
+		// occur over e.g. EC2's elastic filesystem (NFS).
+		const uint64_t lm = OSUtils::getLastModified(path.c_str());
+		if ((lm)&&(e->second.lastModifiedOnDisk != lm)) {
+			if (OSUtils::readFile(path.c_str(),buf)) {
+				try {
+					e->second.lastModifiedOnDisk = lm;
+					e->second.lastCheck = now;
+					e->second.obj = nlohmann::json::parse(buf);
+				} catch ( ... ) {
+					e->second.obj = _EMPTY_JSON;
+				}
+			}
+		}
+
+		return e->second.obj;
+	} else {
+		std::string path(_genPath(n,false));
+		if (!path.length())
+			return _EMPTY_JSON;
+
+		if (!OSUtils::readFile(path.c_str(),buf))
+			return _EMPTY_JSON;
+
+		const uint64_t lm = OSUtils::getLastModified(path.c_str());
+		if (!lm)
+			return _EMPTY_JSON;
+
+		_E &e2 = _db[n];
+		e2.lastModifiedOnDisk = lm;
+		e2.lastCheck = now;
+		try {
+			e2.obj = nlohmann::json::parse(buf);
+		} catch ( ... ) {
+			e2.obj = _EMPTY_JSON;
+		}
+
+		return e2.obj;
+	}
+}
+
+bool JSONDB::_isValidObjectName(const std::string &n)
+{
+	if (n.length() == 0)
+		return false;
+	const char *p = n.c_str();
+	char c;
+	// For security reasons we should not allow dots, backslashes, or other path characters or potential path characters.
+	while ((c = *(p++))) {
+		if (!( ((c >= 'a')&&(c <= 'z')) || ((c >= 'A')&&(c <= 'Z')) || ((c >= '0')&&(c <= '9')) || (c == '/') || (c == '_') || (c == '~') || (c == '-') ))
+			return false;
+	}
+	return true;
+}
+
+std::string JSONDB::_genPath(const std::string &n,bool create)
+{
+	std::vector<std::string> pt(Utils::split(n.c_str(),"/","",""));
+	if (pt.size() == 0)
+		return std::string();
+	if (pt.size() == 1)
+		return pt[0];
+
+	std::string p(_basePath);
+	if (create) OSUtils::mkdir(p.c_str());
+	for(unsigned long i=0,j=pt.size()-1;i<j;++i) {
+		p.push_back(ZT_PATH_SEPARATOR);
+		p.append(pt[i]);
+		if (create) OSUtils::mkdir(p.c_str());
+	}
+
+	p.push_back(ZT_PATH_SEPARATOR);
+	p.append(pt[pt.size()-1]);
+	p.append(".json");
+
+	return p;
+}
+
+void JSONDB::_reloadAll(const std::string &path)
+{
+}
+
+} // namespace ZeroTier
diff --git a/controller/JSONDB.hpp b/controller/JSONDB.hpp
new file mode 100644
index 00000000..b189c530
--- /dev/null
+++ b/controller/JSONDB.hpp
@@ -0,0 +1,88 @@
+/*
+ * ZeroTier One - Network Virtualization Everywhere
+ * Copyright (C) 2011-2015  ZeroTier, Inc.
+ *
+ * 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 3 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef ZT_JSONDB_HPP
+#define ZT_JSONDB_HPP
+
+#include <string>
+#include <map>
+#include <stdexcept>
+#include <vector>
+#include <algorithm>
+
+#include "../node/Constants.hpp"
+#include "../node/Utils.hpp"
+#include "../ext/json/json.hpp"
+#include "../osdep/OSUtils.hpp"
+
+namespace ZeroTier {
+
+/**
+ * Hierarchical JSON store that persists into the filesystem
+ */
+class JSONDB
+{
+public:
+	JSONDB(const std::string &basePath) :
+		_basePath(basePath)
+	{
+		this->_reloadAll(_basePath);
+	}
+
+	bool put(const std::string &n,const nlohmann::json &obj);
+
+	inline bool put(const std::string &n1,const std::string &n2,const nlohmann::json &obj) { return this->put((n1 + "/" + n2),obj); }
+	inline bool put(const std::string &n1,const std::string &n2,const std::string &n3,const nlohmann::json &obj) { return this->put((n1 + "/" + n2 + "/" + n3),obj); }
+
+	const nlohmann::json &get(const std::string &n,unsigned long maxSinceCheck = 0);
+
+	inline const nlohmann::json &get(const std::string &n1,const std::string &n2,unsigned long maxSinceCheck = 0) { return this->get((n1 + "/" + n2),maxSinceCheck); }
+	inline const nlohmann::json &get(const std::string &n1,const std::string &n2,const std::string &n3,unsigned long maxSinceCheck = 0) { return this->get((n1 + "/" + n2 + "/" + n3),maxSinceCheck); }
+	inline const nlohmann::json &get(const std::string &n1,const std::string &n2,const std::string &n3,const std::string &n4,unsigned long maxSinceCheck = 0) { return this->get((n1 + "/" + n2 + "/" + n3 + "/" + n4),maxSinceCheck); }
+	inline const nlohmann::json &get(const std::string &n1,const std::string &n2,const std::string &n3,const std::string &n4,const std::string &n5,unsigned long maxSinceCheck = 0) { return this->get((n1 + "/" + n2 + "/" + n3 + "/" + n4 + "/" + n5),maxSinceCheck); }
+
+	template<typename F>
+	inline void each(F func,unsigned long maxSinceCheck = 0)
+	{
+		const uint64_t now = OSUtils::now();
+		for(std::map<std::string,_E>::const_iterator i(_db.begin());i!=_db.end();++i) {
+			if ((now - i->second.lastCheck) > (uint64_t)maxSinceCheck)
+				this->get(i->first);
+			func(i->first,i->second.obj);
+		}
+	}
+
+private:
+	bool _isValidObjectName(const std::string &n);
+	std::string _genPath(const std::string &n,bool create);
+	void _reloadAll(const std::string &path);
+
+	struct _E
+	{
+		uint64_t lastModifiedOnDisk;
+		uint64_t lastCheck;
+		nlohmann::json obj;
+	};
+
+	std::string _basePath;
+	std::map<std::string,_E> _db;
+};
+
+} // namespace ZeroTier
+
+#endif