src/yang_schema.cpp - CzechLight/netconf-cli - Gitiles

 /*
  * Copyright (C) 2018 CESNET, https://photonics.cesnet.cz/
  * Copyright (C) 2018 FIT CVUT, https://fit.cvut.cz/
  *
  * Written by Václav Kubernát <kubervac@fit.cvut.cz>
  *
 */

 #include <libyang/Libyang.hpp>
 #include <libyang/Tree_Data.hpp>
 #include <libyang/Tree_Schema.hpp>
 #include <string_view>
 #include "UniqueResource.hpp"
 #include "utils.hpp"
 #include "yang_schema.hpp"

 class YangLoadError : public std::runtime_error {
 public:
     using std::runtime_error::runtime_error;
     ~YangLoadError() override = default;
 };

 class UnsupportedYangTypeException : public std::runtime_error {
 public:
     using std::runtime_error::runtime_error;
     ~UnsupportedYangTypeException() override = default;
 };

 class InvalidSchemaQueryException : public std::runtime_error {
 public:
     using std::runtime_error::runtime_error;
     ~InvalidSchemaQueryException() override = default;
 };

 template <typename T>
 std::string pathToYangAbsSchemPath(const T& path)
 {
     std::string res = "/";
     std::string currentModule;

     for (const auto& it : path.m_nodes) {
         const auto name = nodeToSchemaString(it);

         if (it.m_suffix.type() == typeid(module_)) {
             currentModule = name;
             continue;
         } else {
             res += currentModule + ":";
             res += name + "/";
         }
     }

     return res;
 }

 YangSchema::YangSchema()
     : m_context(std::make_shared<libyang::Context>(nullptr, LY_CTX_DISABLE_SEARCHDIRS | LY_CTX_DISABLE_SEARCHDIR_CWD))
 {
 }

 YangSchema::YangSchema(std::shared_ptr<libyang::Context> lyCtx)
     : m_context(lyCtx)
 {

 }

 YangSchema::~YangSchema() = default;

 void YangSchema::addSchemaString(const char* schema)
 {
     if (!m_context->parse_module_mem(schema, LYS_IN_YANG)) {
         throw YangLoadError("Couldn't load schema");
     }
 }

 void YangSchema::addSchemaDirectory(const char* directoryName)
 {
     if (m_context->set_searchdir(directoryName)) {
         throw YangLoadError("Couldn't add schema search directory");
     }
 }

 void YangSchema::addSchemaFile(const char* filename)
 {
     if (!m_context->parse_module_path(filename, LYS_IN_YANG)) {
         throw YangLoadError("Couldn't load schema");
     }
 }

 bool YangSchema::isModule(const std::string& name) const
 {
     const auto set = modules();
     return set.find(name) != set.end();
 }

 bool YangSchema::isContainer(const schemaPath_& location, const ModuleNodePair& node) const
 {
     const auto schemaNode = getSchemaNode(location, node);
     return schemaNode && schemaNode->nodetype() == LYS_CONTAINER;
 }

 bool YangSchema::isLeaf(const schemaPath_& location, const ModuleNodePair& node) const
 {
     const auto schemaNode = getSchemaNode(location, node);
     return schemaNode && schemaNode->nodetype() == LYS_LEAF;
 }

 bool YangSchema::isList(const schemaPath_& location, const ModuleNodePair& node) const
 {
     const auto schemaNode = getSchemaNode(location, node);
     return schemaNode && schemaNode->nodetype() == LYS_LIST;
 }

 bool YangSchema::isPresenceContainer(const schemaPath_& location, const ModuleNodePair& node) const
 {
     if (!isContainer(location, node))
         return false;
     return libyang::Schema_Node_Container(getSchemaNode(location, node)).presence();
 }

 bool YangSchema::leafEnumHasValue(const schemaPath_& location, const ModuleNodePair& node, const std::string& value) const
 {
     auto enums = enumValues(location, node);

     return std::any_of(enums.begin(), enums.end(), [=](const auto& x) { return x == value; });
 }

 const std::set<std::string> YangSchema::enumValues(const schemaPath_& location, const ModuleNodePair& node) const
 {
     if (!isLeaf(location, node) || leafType(location, node) != yang::LeafDataTypes::Enum)
         return {};

     libyang::Schema_Node_Leaf leaf(getSchemaNode(location, node));
     auto type = leaf.type();
     auto enm = type->info()->enums()->enm();
     // The enum can be a derived type and enm() only returns values,
     // if that specific typedef changed the possible values. So we go
     // up the hierarchy until we find a typedef that defined these values.
     while (enm.empty()) {
         type = type->der()->type();
         enm = type->info()->enums()->enm();
     }

     std::vector<libyang::S_Type_Enum> enabled;
     std::copy_if(enm.begin(), enm.end(), std::back_inserter(enabled), [](const libyang::S_Type_Enum& it) {
         auto iffeatures = it->iffeature();
         return std::all_of(iffeatures.begin(), iffeatures.end(), [](auto it) { return it->value(); });
     });

     std::set<std::string> enumSet;
     std::transform(enabled.begin(), enabled.end(), std::inserter(enumSet, enumSet.end()), [](auto it) { return it->name(); });
     return enumSet;
 }

 const std::set<std::string> YangSchema::validIdentities(const schemaPath_& location, const ModuleNodePair& node, const Prefixes prefixes) const
 {
     if (!isLeaf(location, node) || leafType(location, node) != yang::LeafDataTypes::IdentityRef)
         return {};

     std::set<std::string> identSet;

     auto topLevelModule = location.m_nodes.empty() ? node.first.get() : location.m_nodes.front().m_prefix.get().m_name;
     auto insertToSet = [&identSet, prefixes, topLevelModule](auto module, auto name) {
         std::string stringIdent;
         if (prefixes == Prefixes::Always || topLevelModule != module) {
             stringIdent += module;
             stringIdent += ":";
         }
         stringIdent += name;
         identSet.emplace(stringIdent);
     };

     auto leaf = std::make_shared<libyang::Schema_Node_Leaf>(getSchemaNode(location, node));
     auto info = leaf->type()->info();
     for (auto base : info->ident()->ref()) { // Iterate over all bases
         insertToSet(base->module()->name(), base->name());
         // Iterate over derived identities (this is recursive!)
         for (auto derived : base->der()->schema()) {
             insertToSet(derived->module()->name(), derived->name());
         }
     }

     return identSet;
 }

 bool YangSchema::leafIdentityIsValid(const schemaPath_& location, const ModuleNodePair& node, const ModuleValuePair& value) const
 {
     auto identities = validIdentities(location, node, Prefixes::Always);

     auto topLevelModule = location.m_nodes.empty() ? node.first.get() : location.m_nodes.front().m_prefix.get().m_name;
     auto identModule = value.first ? value.first.value() : topLevelModule;
     return std::any_of(identities.begin(), identities.end(), [toFind = identModule + ":" + value.second](const auto& x) { return x == toFind; });
 }

 bool YangSchema::listHasKey(const schemaPath_& location, const ModuleNodePair& node, const std::string& key) const
 {
     if (!isList(location, node))
         return false;
     const auto keys = listKeys(location, node);
     return keys.find(key) != keys.end();
 }

 libyang::S_Schema_Node YangSchema::impl_getSchemaNode(const std::string& node) const
 {
     // If no node is found find_path prints an error message, so we have to
     // disable logging
     // https://github.com/CESNET/libyang/issues/753
     {
         int oldOptions;
         auto logBlocker = make_unique_resource(
             [&oldOptions]() {
                 oldOptions = libyang::set_log_options(0);
             },
             [&oldOptions]() {
                 libyang::set_log_options(oldOptions);
             });
         return m_context->get_node(nullptr, node.c_str());
     }
 }


 libyang::S_Schema_Node YangSchema::getSchemaNode(const std::string& node) const
 {
     return impl_getSchemaNode(node);
 }

 libyang::S_Schema_Node YangSchema::getSchemaNode(const schemaPath_& location, const ModuleNodePair& node) const
 {
     std::string absPath = joinPaths(pathToSchemaString(location, Prefixes::Always), fullNodeName(location, node));

     return impl_getSchemaNode(absPath);
 }

 const std::set<std::string> YangSchema::listKeys(const schemaPath_& location, const ModuleNodePair& node) const
 {
     std::set<std::string> keys;
     if (!isList(location, node))
         return keys;
     libyang::Schema_Node_List list(getSchemaNode(location, node));
     const auto& keysVec = list.keys();

     std::transform(keysVec.begin(), keysVec.end(), std::inserter(keys, keys.begin()), [](const auto& it) { return it->name(); });
     return keys;
 }

 yang::LeafDataTypes lyTypeToLeafDataTypes(LY_DATA_TYPE type)
 {
     switch (type) {
     case LY_TYPE_STRING:
         return yang::LeafDataTypes::String;
     case LY_TYPE_DEC64:
         return yang::LeafDataTypes::Decimal;
     case LY_TYPE_BOOL:
         return yang::LeafDataTypes::Bool;
     case LY_TYPE_INT8:
         return yang::LeafDataTypes::Int8;
     case LY_TYPE_INT16:
         return yang::LeafDataTypes::Int16;
     case LY_TYPE_INT32:
         return yang::LeafDataTypes::Int32;
     case LY_TYPE_INT64:
         return yang::LeafDataTypes::Int64;
     case LY_TYPE_UINT8:
         return yang::LeafDataTypes::Uint8;
     case LY_TYPE_UINT16:
         return yang::LeafDataTypes::Uint16;
     case LY_TYPE_UINT32:
         return yang::LeafDataTypes::Uint32;
     case LY_TYPE_UINT64:
         return yang::LeafDataTypes::Uint64;
     case LY_TYPE_ENUM:
         return yang::LeafDataTypes::Enum;
     case LY_TYPE_BINARY:
         return yang::LeafDataTypes::Binary;
     case LY_TYPE_IDENT:
         return yang::LeafDataTypes::IdentityRef;
     case LY_TYPE_LEAFREF:
         return yang::LeafDataTypes::LeafRef;
     default:
         using namespace std::string_literals;
         throw std::logic_error{"internal error: unsupported libyang data type "s + std::to_string(type)};
     }
 }

 yang::LeafDataTypes YangSchema::leafType(const schemaPath_& location, const ModuleNodePair& node) const
 {
     using namespace std::string_literals;
     if (!isLeaf(location, node))
         throw InvalidSchemaQueryException(fullNodeName(location, node) + " is not a leaf");

     libyang::Schema_Node_Leaf leaf(getSchemaNode(location, node));
     auto baseType{leaf.type()->base()};
     try {
         return lyTypeToLeafDataTypes(baseType);
     } catch (std::logic_error& ex) {
         throw UnsupportedYangTypeException("the type of "s + fullNodeName(location, node) + " is not supported: " + ex.what());
     }
 }

 yang::LeafDataTypes YangSchema::leafrefBase(const schemaPath_& location, const ModuleNodePair& node) const
 {
     using namespace std::string_literals;
     libyang::Schema_Node_Leaf leaf(getSchemaNode(location, node));
     try {
         return lyTypeToLeafDataTypes(leaf.type()->info()->lref()->target()->type()->base());
     } catch (std::logic_error& ex) {
         throw UnsupportedYangTypeException("the type of "s + fullNodeName(location, node) + " is not supported: " + ex.what());
     }
 }

 std::set<std::string> YangSchema::modules() const
 {
     const auto& modules = m_context->get_module_iter();

     std::set<std::string> res;
     std::transform(modules.begin(), modules.end(), std::inserter(res, res.end()), [](const auto module) { return module->name(); });
     return res;
 }

 std::set<std::string> YangSchema::childNodes(const schemaPath_& path, const Recursion recursion) const
 {
     using namespace std::string_view_literals;
     std::set<std::string> res;
     std::vector<libyang::S_Schema_Node> nodes;

     if (path.m_nodes.empty()) {
         nodes = m_context->data_instantiables(0);
     } else {
         const auto pathString = pathToSchemaString(path, Prefixes::Always);
         const auto node = getSchemaNode(pathString);
         nodes = node->child_instantiables(0);
     }

     for (const auto node : nodes) {
         if (node->module()->name() == "ietf-yang-library"sv)
             continue;
         if (recursion == Recursion::Recursive) {
             for (auto it : node->tree_dfs()) {
                 res.insert(it->path(LYS_PATH_FIRST_PREFIX));
             }
         } else {
             std::string toInsert;
             if (path.m_nodes.empty() || path.m_nodes.front().m_prefix.get().m_name != node->module()->name()) {
                 toInsert += node->module()->name();
                 toInsert += ":";
             }
             toInsert += node->name();
             res.insert(toInsert);
         }
     }

     return res;
 }

 std::set<std::string> YangSchema::moduleNodes(const module_& module, const Recursion recursion) const
 {
     std::set<std::string> res;
     const auto yangModule = m_context->get_module(module.m_name.c_str());

     std::vector<libyang::S_Schema_Node> nodes;

     for (const auto node : yangModule->data_instantiables(0)) {
         if (recursion == Recursion::Recursive) {
             for (const auto it : node->tree_dfs()) {
                 res.insert(it->path(LYS_PATH_FIRST_PREFIX));
             }
         } else {
             res.insert(module.m_name + ":" + node->name());
         }
     }

     return res;
 }

 void YangSchema::loadModule(const std::string& moduleName)
 {
     m_context->load_module(moduleName.c_str());
 }

 void YangSchema::enableFeature(const std::string& moduleName, const std::string& featureName)
 {
     m_context->get_module(moduleName.c_str())->feature_enable(featureName.c_str());
 }

 void YangSchema::registerModuleCallback(const std::function<std::string(const char*, const char*, const char*, const char*)>& clb)
 {
     auto lambda = [clb](const char* mod_name, const char* mod_revision, const char* submod_name, const char* submod_revision) {
         (void)submod_revision;
         auto moduleSource = clb(mod_name, mod_revision, submod_name, submod_revision);
         if (moduleSource.empty()) {
             return libyang::Context::mod_missing_cb_return{LYS_IN_YANG, nullptr};
         }
         return libyang::Context::mod_missing_cb_return{LYS_IN_YANG, strdup(moduleSource.c_str())};
     };

     auto deleter = [](void* data) {
         free(data);
     };
     m_context->add_missing_module_callback(lambda, deleter);
 }

 std::shared_ptr<libyang::Data_Node> YangSchema::dataNodeFromPath(const std::string& path, const std::optional<const std::string> value) const
 {
     return std::make_shared<libyang::Data_Node>(m_context,
                                                 path.c_str(),
                                                 value ? value.value().c_str() : nullptr,
                                                 LYD_ANYDATA_CONSTSTRING,
                                                 LYD_PATH_OPT_EDIT);
 }

 std::shared_ptr<libyang::Module> YangSchema::getYangModule(const std::string& name)
 {
     return m_context->get_module(name.c_str(), nullptr, 0);
 }
	/*
	* Copyright (C) 2018 CESNET, https://photonics.cesnet.cz/
	* Copyright (C) 2018 FIT CVUT, https://fit.cvut.cz/
	*
	* Written by Václav Kubernát <kubervac@fit.cvut.cz>
	*
	*/

	#include <libyang/Libyang.hpp>
	#include <libyang/Tree_Data.hpp>
	#include <libyang/Tree_Schema.hpp>
	#include <string_view>
	#include "UniqueResource.hpp"
	#include "utils.hpp"
	#include "yang_schema.hpp"

	class YangLoadError : public std::runtime_error {
	public:
	using std::runtime_error::runtime_error;
	~YangLoadError() override = default;
	};

	class UnsupportedYangTypeException : public std::runtime_error {
	public:
	using std::runtime_error::runtime_error;
	~UnsupportedYangTypeException() override = default;
	};

	class InvalidSchemaQueryException : public std::runtime_error {
	public:
	using std::runtime_error::runtime_error;
	~InvalidSchemaQueryException() override = default;
	};

	template <typename T>
	std::string pathToYangAbsSchemPath(const T& path)
	{
	std::string res = "/";
	std::string currentModule;

	for (const auto& it : path.m_nodes) {
	const auto name = nodeToSchemaString(it);

	if (it.m_suffix.type() == typeid(module_)) {
	currentModule = name;
	continue;
	} else {
	res += currentModule + ":";
	res += name + "/";
	}
	}

	return res;
	}

	YangSchema::YangSchema()
	: m_context(std::make_shared<libyang::Context>(nullptr, LY_CTX_DISABLE_SEARCHDIRS \| LY_CTX_DISABLE_SEARCHDIR_CWD))
	{
	}

	YangSchema::YangSchema(std::shared_ptr<libyang::Context> lyCtx)
	: m_context(lyCtx)
	{

	}

	YangSchema::~YangSchema() = default;

	void YangSchema::addSchemaString(const char* schema)
	{
	if (!m_context->parse_module_mem(schema, LYS_IN_YANG)) {
	throw YangLoadError("Couldn't load schema");
	}
	}

	void YangSchema::addSchemaDirectory(const char* directoryName)
	{
	if (m_context->set_searchdir(directoryName)) {
	throw YangLoadError("Couldn't add schema search directory");
	}
	}

	void YangSchema::addSchemaFile(const char* filename)
	{
	if (!m_context->parse_module_path(filename, LYS_IN_YANG)) {
	throw YangLoadError("Couldn't load schema");
	}
	}

	bool YangSchema::isModule(const std::string& name) const
	{
	const auto set = modules();
	return set.find(name) != set.end();
	}

	bool YangSchema::isContainer(const schemaPath_& location, const ModuleNodePair& node) const
	{
	const auto schemaNode = getSchemaNode(location, node);
	return schemaNode && schemaNode->nodetype() == LYS_CONTAINER;
	}

	bool YangSchema::isLeaf(const schemaPath_& location, const ModuleNodePair& node) const
	{
	const auto schemaNode = getSchemaNode(location, node);
	return schemaNode && schemaNode->nodetype() == LYS_LEAF;
	}

	bool YangSchema::isList(const schemaPath_& location, const ModuleNodePair& node) const
	{
	const auto schemaNode = getSchemaNode(location, node);
	return schemaNode && schemaNode->nodetype() == LYS_LIST;
	}

	bool YangSchema::isPresenceContainer(const schemaPath_& location, const ModuleNodePair& node) const
	{
	if (!isContainer(location, node))
	return false;
	return libyang::Schema_Node_Container(getSchemaNode(location, node)).presence();
	}

	bool YangSchema::leafEnumHasValue(const schemaPath_& location, const ModuleNodePair& node, const std::string& value) const
	{
	auto enums = enumValues(location, node);

	return std::any_of(enums.begin(), enums.end(), [=](const auto& x) { return x == value; });
	}

	const std::set<std::string> YangSchema::enumValues(const schemaPath_& location, const ModuleNodePair& node) const
	{
	if (!isLeaf(location, node) \|\| leafType(location, node) != yang::LeafDataTypes::Enum)
	return {};

	libyang::Schema_Node_Leaf leaf(getSchemaNode(location, node));
	auto type = leaf.type();
	auto enm = type->info()->enums()->enm();
	// The enum can be a derived type and enm() only returns values,
	// if that specific typedef changed the possible values. So we go
	// up the hierarchy until we find a typedef that defined these values.
	while (enm.empty()) {
	type = type->der()->type();
	enm = type->info()->enums()->enm();
	}

	std::vector<libyang::S_Type_Enum> enabled;
	std::copy_if(enm.begin(), enm.end(), std::back_inserter(enabled), [](const libyang::S_Type_Enum& it) {
	auto iffeatures = it->iffeature();
	return std::all_of(iffeatures.begin(), iffeatures.end(), [](auto it) { return it->value(); });
	});

	std::set<std::string> enumSet;
	std::transform(enabled.begin(), enabled.end(), std::inserter(enumSet, enumSet.end()), [](auto it) { return it->name(); });
	return enumSet;
	}

	const std::set<std::string> YangSchema::validIdentities(const schemaPath_& location, const ModuleNodePair& node, const Prefixes prefixes) const
	{
	if (!isLeaf(location, node) \|\| leafType(location, node) != yang::LeafDataTypes::IdentityRef)
	return {};

	std::set<std::string> identSet;

	auto topLevelModule = location.m_nodes.empty() ? node.first.get() : location.m_nodes.front().m_prefix.get().m_name;
	auto insertToSet = [&identSet, prefixes, topLevelModule](auto module, auto name) {
	std::string stringIdent;
	if (prefixes == Prefixes::Always \|\| topLevelModule != module) {
	stringIdent += module;
	stringIdent += ":";
	}
	stringIdent += name;
	identSet.emplace(stringIdent);
	};

	auto leaf = std::make_shared<libyang::Schema_Node_Leaf>(getSchemaNode(location, node));
	auto info = leaf->type()->info();
	for (auto base : info->ident()->ref()) { // Iterate over all bases
	insertToSet(base->module()->name(), base->name());
	// Iterate over derived identities (this is recursive!)
	for (auto derived : base->der()->schema()) {
	insertToSet(derived->module()->name(), derived->name());
	}
	}

	return identSet;
	}

	bool YangSchema::leafIdentityIsValid(const schemaPath_& location, const ModuleNodePair& node, const ModuleValuePair& value) const
	{
	auto identities = validIdentities(location, node, Prefixes::Always);

	auto topLevelModule = location.m_nodes.empty() ? node.first.get() : location.m_nodes.front().m_prefix.get().m_name;
	auto identModule = value.first ? value.first.value() : topLevelModule;
	return std::any_of(identities.begin(), identities.end(), [toFind = identModule + ":" + value.second](const auto& x) { return x == toFind; });
	}

	bool YangSchema::listHasKey(const schemaPath_& location, const ModuleNodePair& node, const std::string& key) const
	{
	if (!isList(location, node))
	return false;
	const auto keys = listKeys(location, node);
	return keys.find(key) != keys.end();
	}

	libyang::S_Schema_Node YangSchema::impl_getSchemaNode(const std::string& node) const
	{
	// If no node is found find_path prints an error message, so we have to
	// disable logging
	// https://github.com/CESNET/libyang/issues/753
	{
	int oldOptions;
	auto logBlocker = make_unique_resource(
	[&oldOptions]() {
	oldOptions = libyang::set_log_options(0);
	},
	[&oldOptions]() {
	libyang::set_log_options(oldOptions);
	});
	return m_context->get_node(nullptr, node.c_str());
	}
	}


	libyang::S_Schema_Node YangSchema::getSchemaNode(const std::string& node) const
	{
	return impl_getSchemaNode(node);
	}

	libyang::S_Schema_Node YangSchema::getSchemaNode(const schemaPath_& location, const ModuleNodePair& node) const
	{
	std::string absPath = joinPaths(pathToSchemaString(location, Prefixes::Always), fullNodeName(location, node));

	return impl_getSchemaNode(absPath);
	}

	const std::set<std::string> YangSchema::listKeys(const schemaPath_& location, const ModuleNodePair& node) const
	{
	std::set<std::string> keys;
	if (!isList(location, node))
	return keys;
	libyang::Schema_Node_List list(getSchemaNode(location, node));
	const auto& keysVec = list.keys();

	std::transform(keysVec.begin(), keysVec.end(), std::inserter(keys, keys.begin()), [](const auto& it) { return it->name(); });
	return keys;
	}

	yang::LeafDataTypes lyTypeToLeafDataTypes(LY_DATA_TYPE type)
	{
	switch (type) {
	case LY_TYPE_STRING:
	return yang::LeafDataTypes::String;
	case LY_TYPE_DEC64:
	return yang::LeafDataTypes::Decimal;
	case LY_TYPE_BOOL:
	return yang::LeafDataTypes::Bool;
	case LY_TYPE_INT8:
	return yang::LeafDataTypes::Int8;
	case LY_TYPE_INT16:
	return yang::LeafDataTypes::Int16;
	case LY_TYPE_INT32:
	return yang::LeafDataTypes::Int32;
	case LY_TYPE_INT64:
	return yang::LeafDataTypes::Int64;
	case LY_TYPE_UINT8:
	return yang::LeafDataTypes::Uint8;
	case LY_TYPE_UINT16:
	return yang::LeafDataTypes::Uint16;
	case LY_TYPE_UINT32:
	return yang::LeafDataTypes::Uint32;
	case LY_TYPE_UINT64:
	return yang::LeafDataTypes::Uint64;
	case LY_TYPE_ENUM:
	return yang::LeafDataTypes::Enum;
	case LY_TYPE_BINARY:
	return yang::LeafDataTypes::Binary;
	case LY_TYPE_IDENT:
	return yang::LeafDataTypes::IdentityRef;
	case LY_TYPE_LEAFREF:
	return yang::LeafDataTypes::LeafRef;
	default:
	using namespace std::string_literals;
	throw std::logic_error{"internal error: unsupported libyang data type "s + std::to_string(type)};
	}
	}

	yang::LeafDataTypes YangSchema::leafType(const schemaPath_& location, const ModuleNodePair& node) const
	{
	using namespace std::string_literals;
	if (!isLeaf(location, node))
	throw InvalidSchemaQueryException(fullNodeName(location, node) + " is not a leaf");

	libyang::Schema_Node_Leaf leaf(getSchemaNode(location, node));
	auto baseType{leaf.type()->base()};
	try {
	return lyTypeToLeafDataTypes(baseType);
	} catch (std::logic_error& ex) {
	throw UnsupportedYangTypeException("the type of "s + fullNodeName(location, node) + " is not supported: " + ex.what());
	}
	}

	yang::LeafDataTypes YangSchema::leafrefBase(const schemaPath_& location, const ModuleNodePair& node) const
	{
	using namespace std::string_literals;
	libyang::Schema_Node_Leaf leaf(getSchemaNode(location, node));
	try {
	return lyTypeToLeafDataTypes(leaf.type()->info()->lref()->target()->type()->base());
	} catch (std::logic_error& ex) {
	throw UnsupportedYangTypeException("the type of "s + fullNodeName(location, node) + " is not supported: " + ex.what());
	}
	}

	std::set<std::string> YangSchema::modules() const
	{
	const auto& modules = m_context->get_module_iter();

	std::set<std::string> res;
	std::transform(modules.begin(), modules.end(), std::inserter(res, res.end()), [](const auto module) { return module->name(); });
	return res;
	}

	std::set<std::string> YangSchema::childNodes(const schemaPath_& path, const Recursion recursion) const
	{
	using namespace std::string_view_literals;
	std::set<std::string> res;
	std::vector<libyang::S_Schema_Node> nodes;

	if (path.m_nodes.empty()) {
	nodes = m_context->data_instantiables(0);
	} else {
	const auto pathString = pathToSchemaString(path, Prefixes::Always);
	const auto node = getSchemaNode(pathString);
	nodes = node->child_instantiables(0);
	}

	for (const auto node : nodes) {
	if (node->module()->name() == "ietf-yang-library"sv)
	continue;
	if (recursion == Recursion::Recursive) {
	for (auto it : node->tree_dfs()) {
	res.insert(it->path(LYS_PATH_FIRST_PREFIX));
	}
	} else {
	std::string toInsert;
	if (path.m_nodes.empty() \|\| path.m_nodes.front().m_prefix.get().m_name != node->module()->name()) {
	toInsert += node->module()->name();
	toInsert += ":";
	}
	toInsert += node->name();
	res.insert(toInsert);
	}
	}

	return res;
	}

	std::set<std::string> YangSchema::moduleNodes(const module_& module, const Recursion recursion) const
	{
	std::set<std::string> res;
	const auto yangModule = m_context->get_module(module.m_name.c_str());

	std::vector<libyang::S_Schema_Node> nodes;

	for (const auto node : yangModule->data_instantiables(0)) {
	if (recursion == Recursion::Recursive) {
	for (const auto it : node->tree_dfs()) {
	res.insert(it->path(LYS_PATH_FIRST_PREFIX));
	}
	} else {
	res.insert(module.m_name + ":" + node->name());
	}
	}

	return res;
	}

	void YangSchema::loadModule(const std::string& moduleName)
	{
	m_context->load_module(moduleName.c_str());
	}

	void YangSchema::enableFeature(const std::string& moduleName, const std::string& featureName)
	{
	m_context->get_module(moduleName.c_str())->feature_enable(featureName.c_str());
	}

	void YangSchema::registerModuleCallback(const std::function<std::string(const char, const char, const char, const char)>& clb)
	{
	auto lambda = [clb](const char* mod_name, const char* mod_revision, const char* submod_name, const char* submod_revision) {
	(void)submod_revision;
	auto moduleSource = clb(mod_name, mod_revision, submod_name, submod_revision);
	if (moduleSource.empty()) {
	return libyang::Context::mod_missing_cb_return{LYS_IN_YANG, nullptr};
	}
	return libyang::Context::mod_missing_cb_return{LYS_IN_YANG, strdup(moduleSource.c_str())};
	};

	auto deleter = [](void* data) {
	free(data);
	};
	m_context->add_missing_module_callback(lambda, deleter);
	}

	std::shared_ptr<libyang::Data_Node> YangSchema::dataNodeFromPath(const std::string& path, const std::optional<const std::string> value) const
	{
	return std::make_shared<libyang::Data_Node>(m_context,
	path.c_str(),
	value ? value.value().c_str() : nullptr,
	LYD_ANYDATA_CONSTSTRING,
	LYD_PATH_OPT_EDIT);
	}

	std::shared_ptr<libyang::Module> YangSchema::getYangModule(const std::string& name)
	{
	return m_context->get_module(name.c_str(), nullptr, 0);
	}