| /** |
| * @file libyang.h |
| * @author Radek Krejci <rkrejci@cesnet.cz> |
| * @brief The main libyang public header. |
| * |
| * Copyright (c) 2015-2017 CESNET, z.s.p.o. |
| * |
| * This source code is licensed under BSD 3-Clause License (the "License"). |
| * You may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * https://opensource.org/licenses/BSD-3-Clause |
| */ |
| |
| #ifndef LY_LIBYANG_H_ |
| #define LY_LIBYANG_H_ |
| |
| #include <stdio.h> |
| |
| @ENABLE_CACHE_MACRO@ |
| |
| @ENABLE_LATEST_REVISIONS_MACRO@ |
| |
| #include "tree_schema.h" |
| #include "tree_data.h" |
| #include "xml.h" |
| #include "dict.h" |
| |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| |
| #define LY_VERSION_MAJOR @LIBYANG_MAJOR_VERSION@ /**< libyang major version number */ |
| #define LY_VERSION_MINOR @LIBYANG_MINOR_VERSION@ /**< libyang minor version number */ |
| #define LY_VERSION_MICRO @LIBYANG_MICRO_VERSION@ /**< libyang micro version number */ |
| |
| /** |
| * @mainpage About |
| * |
| * libyang is a library implementing processing of the YANG schemas and data modeled by the YANG language. The |
| * library is implemented in C for GNU/Linux and provides C API. |
| * |
| * @section about-features Main Features |
| * |
| * - [Parsing (and validating) schemas](@ref howtoschemasparsers) in YANG format. |
| * - [Parsing (and validating) schemas](@ref howtoschemasparsers) in YIN format. |
| * - [Parsing, validating and printing instance data](@ref howtodata) in XML format. |
| * - [Parsing, validating and printing instance data](@ref howtodata) in JSON format |
| * ([RFC 7951](https://tools.ietf.org/html/rfc7951)). |
| * - [Manipulation with the instance data](@ref howtodatamanipulators). |
| * - Support for [default values in the instance data](@ref howtodatawd) ([RFC 6243](https://tools.ietf.org/html/rfc6243)). |
| * - Support for [YANG extensions and user types](@ref howtoschemaplugins). |
| * - Support for [YANG Metadata](@ref howtoschemametadata) ([RFC 7952](https://tools.ietf.org/html/rfc6243)). |
| * |
| * The current implementation covers YANG 1.0 ([RFC 6020](https://tools.ietf.org/html/rfc6020)) as well as |
| * YANG 1.1 ([RFC 7950](https://tools.ietf.org/html/rfc7950)). |
| * |
| * @subsection about-features-others Extra (side-effect) Features |
| * |
| * - XML parser. |
| * - Optimized string storage (dictionary). |
| * |
| * @section about-license License |
| * |
| * Copyright (c) 2015-2017 CESNET, z.s.p.o. |
| * |
| * (The BSD 3-Clause License) |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * 3. Neither the name of the Company nor the names of its contributors |
| * may be used to endorse or promote products derived from this |
| * software without specific prior written permission. |
| */ |
| |
| /** |
| * @page howto How To ... |
| * |
| * - @subpage howtocontext |
| * - @subpage howtoschemas |
| * - @subpage howtodata |
| * - @subpage howtoxpath |
| * - @subpage howtoxml |
| * - @subpage howtothreads |
| * - @subpage howtologger |
| */ |
| |
| /** @page howtocontext Context |
| * |
| * The context concept allows callers to work in environments with different sets of YANG schemas. |
| * |
| * The first step in libyang is to create a new context using ly_ctx_new(). It returns a handler |
| * used in the following work. |
| * |
| * When creating a new context, search dir can be specified (NULL is accepted) to provide directory |
| * where libyang will automatically search for schemas being imported or included. The search path |
| * can be later changed via ly_ctx_set_searchdir() and ly_ctx_unset_searchdrs() functions. If the search dir |
| * is specified, it is explored first. Except the searchpath, also all its subdirectories (and symlinks) are |
| * taken into account. In case the module is not found, libyang tries to find the (sub)module also in the current |
| * working working directory. Note, that in this case only the current directory without any other subdirectory |
| * is examined. This automatic searching can be completely avoided when the caller sets module searching callback |
| * (#ly_module_imp_clb) via ly_ctx_set_module_imp_clb(), but both approaches can also be combined. |
| * |
| * Schemas are added into the context using [parser functions](@ref howtoschemasparsers) - \b lys_parse_*(). |
| * In case of schemas, also ly_ctx_load_module() can be used - in that case the #ly_module_imp_clb or automatic |
| * search in search dir and in the current working directory is used. |
| * |
| * Similarly, data trees can be parsed by \b lyd_parse_*() functions. Note, that functions for schemas have \b lys_ |
| * prefix while functions for instance data have \b lyd_ prefix. It can happen during data parsing that a schema is |
| * required and __not found__ in the context or the schema is found, but is __only imported__, not implemented (so the |
| * data cannot actually be instantiated). In these cases, a callback is called, which should add this schema into |
| * the context or change its conformance to implemented. You can set the callback using ly_ctx_set_module_data_clb() |
| * (more in @ref howtodataparsers and @ref howtodatavalidation). |
| * |
| * Context can hold multiple revisions of the same schema, but only one of them can be implemented. The schema is not |
| * implemented in case it is automatically loaded as import for another module and it is not referenced in such |
| * a module (and no other) as target of leafref, augment or deviation. All modules with deviation definition are always |
| * marked as implemented. The imported (not implemented) module can be set implemented by lys_set_implemented(). But |
| * the implemented module cannot be changed back to just imported module. The imported modules are used only as a |
| * source of definitions for types and groupings for uses statements. The data in such modules are ignored - caller |
| * is not allowed to create the data (including instantiating identities) defined in the model via data parsers, |
| * the default nodes are not added into any data tree and mandatory nodes are not checked in the data trees. This |
| * can be changed by ly_ctx_set_allimplemented() function, which causes that all the imported modules are automatically |
| * set to be implemented. |
| * |
| * When loading/importing a module without revision, the latest revision of the required module is supposed to load. |
| * For a context, the first time the latest revision of a module is requested, it is properly searched for and loaded. |
| * However, when this module is requested (without revision) the second time, the one found previously is returned. |
| * This has the advantage of not searching for the module repeatedly but the drawback that if a later revision |
| * of the module is later made available, this context will not use it. If you are aware of a case when this |
| * optimization could cause problems, you can disable it using a cmake(1) build option (variable). |
| * |
| * Context holds all modules and their submodules internally. To get |
| * a specific module or submodule, use ly_ctx_get_module() and ly_ctx_get_submodule(). There are some additional |
| * alternatives to these functions (with different parameters). If you need to do something with all the modules or |
| * submodules in the context, it is advised to iterate over them using ly_ctx_get_module_iter(), it is |
| * the most efficient way. Alternatively, the ly_ctx_info() function can be used to get complex information |
| * about the schemas in the context in the form of data tree defined by |
| * <a href="https://tools.ietf.org/html/draft-ietf-netconf-yang-library-04">ietf-yang-library</a> schema. |
| * To get a specific node defined in a module in the context, ly_ctx_find_path() or ly_ctx_get_node() can be used. |
| * |
| * Modules held by a context can be removed by ly_ctx_remove_module(). Besides removing the module, it is possible |
| * just to disable it with lys_set_disabled(). In this case the module is hidden in the context (disabled modules can |
| * be iterated via ly_ctx_get_disabled_module_iter()) and not used during the common work with the context. The module |
| * is enabled explicitly by calling lys_set_enabled() or implicitly by the request to load the schema (directly or |
| * indirectly via import of another module) into the context. |
| * |
| * To clean the context from all the loaded modules (except the [internal modules](@ref howtoschemasparsers)), the |
| * ly_ctx_clean() function can be used. To remove the context, there is ly_ctx_destroy() function. |
| * |
| * - @subpage howtocontextdict |
| * |
| * \note API for this group of functions is available in the [context module](@ref context). |
| * |
| * Functions List |
| * -------------- |
| * - ly_ctx_new() |
| * - ly_ctx_set_searchdir() |
| * - ly_ctx_unset_searchdirs() |
| * - ly_ctx_get_searchdir() |
| * - ly_ctx_set_module_imp_clb() |
| * - ly_ctx_get_module_imp_clb() |
| * - ly_ctx_set_module_data_clb() |
| * - ly_ctx_get_module_data_clb() |
| * - ly_ctx_set_allimplemented() |
| * - ly_ctx_unset_allimplemented() |
| * - ly_ctx_load_module() |
| * - ly_ctx_info() |
| * - ly_ctx_get_module_iter() |
| * - ly_ctx_get_disabled_module_iter() |
| * - ly_ctx_get_module() |
| * - ly_ctx_get_module_older() |
| * - ly_ctx_get_module_by_ns() |
| * - ly_ctx_get_submodule() |
| * - ly_ctx_get_submodule2() |
| * - ly_ctx_get_node() |
| * - ly_ctx_find_path() |
| * - ly_ctx_remove_module() |
| * - ly_ctx_clean() |
| * - ly_ctx_destroy() |
| * - lys_set_implemented() |
| * - lys_set_disabled() |
| * - lys_set_enabled() |
| */ |
| |
| /** |
| * @page howtocontextdict Context Dictionary |
| * |
| * Context includes dictionary to store strings more effectively. The most of strings repeats quite often in schema |
| * as well as data trees. Therefore, instead of allocating those strings each time they appear, libyang stores them |
| * as records in the dictionary. The basic API to the context dictionary is public, so even a caller application can |
| * use the dictionary. |
| * |
| * To insert a string into the dictionary, caller can use lydict_insert() (adding a constant string) or |
| * lydict_insert_zc() (for dynamically allocated strings that won't be used by the caller after its insertion into |
| * the dictionary). Both functions return the pointer to the inserted string in the dictionary record. |
| * |
| * To remove (reference of the) string from the context dictionary, lydict_remove() is supposed to be used. |
| * |
| * \note Incorrect usage of the dictionary can break libyang functionality. |
| * |
| * \note API for this group of functions is described in the [XML Parser module](@ref dict). |
| * |
| * Functions List |
| * -------------- |
| * - lydict_insert() |
| * - lydict_insert_zc() |
| * - lydict_remove() |
| */ |
| |
| /** |
| * @page howtoschemas Schemas |
| * |
| * |
| * Schema is an internal libyang's representation of a YANG data model. Each schema is connected with |
| * its [context](@ref howtocontext) and loaded using [parser functions](@ref howtoschemasparsers). It means, that |
| * the schema cannot be created (nor changed) programmatically. In libyang, schemas are used only to |
| * access data model definitions. |
| * |
| * Schema tree nodes are able to hold private objects (via a pointer to a structure, function, variable, ...) used by |
| * a caller application. Such an object can be assigned to a specific node using lys_set_private() function. |
| * Note that the object is not freed by libyang when the context is being destroyed. So the caller is responsible |
| * for freeing the provided structure after the context is destroyed or the private pointer is set to NULL in |
| * appropriate schema nodes where the object was previously set. This can be automated via destructor function |
| * to free these private objects. The destructor is passed to the ly_ctx_destroy() function. On the other hand, |
| * freeing the object while the schema tree is still in use can lead to a segmentation fault. |
| * |
| * - @subpage howtoschemasparsers |
| * - @subpage howtoschemasfeatures |
| * - @subpage howtoschemaplugins |
| * - @subpage howtoschemasprinters |
| * |
| * \note There are many functions to access information from the schema trees. Details are available in |
| * the [Schema Tree module](@ref schematree). |
| * |
| * For information about difference between implemented and imported modules, see the |
| * [context description](@ref howtocontext). |
| * |
| * Functions List (not assigned to above subsections) |
| * -------------------------------------------------- |
| * - lys_getnext() |
| * - lys_parent() |
| * - lys_module() |
| * - lys_node_module() |
| * - lys_set_private() |
| * - lys_set_implemented() |
| * - lys_set_disabled() |
| * - lys_set_enabled() |
| */ |
| |
| /** |
| * @page howtoschemasparsers Parsing Schemas |
| * |
| * Schema parser allows to read schema from a specific format. libyang supports the following schema formats: |
| * |
| * - YANG |
| * |
| * Basic YANG schemas format described in [RFC 6020](http://tools.ietf.org/html/rfc6020) and |
| * [RFC 7951](http://tools.ietf.org/html/rfc7951) (so both YANG 1.0 and YANG 1.1 versions are supported). |
| * |
| * - YIN |
| * |
| * Alternative XML-based format to YANG - YANG Independent Notation. The details can be found in |
| * [RFC 6020](http://tools.ietf.org/html/rfc6020#section-11) and |
| * [RFC 7951](http://tools.ietf.org/html/rfc7951#section-13). |
| * |
| * When the [context](@ref howtocontext) is created, it already contains the following schemas, which |
| * are implemented internally by libyang: |
| * - ietf-yang-metadata@2016-08-05 |
| * - yang@2017-02-20 |
| * - ietf-inet-types@2013-07-15 |
| * - ietf-yang-types@2013-07-15 |
| * - ietf-yang-library@2016-06-21 |
| * |
| * The `yang` schema is the libyang's internal module to provide namespace and definitions of for various YANG |
| * attributes described in [RFC 7951](https://tools.ietf.org/html/rfc6243) (such as `insert` attribute for |
| * edit-config's data). |
| * |
| * Other schemas can be added to the context manually as described in [context page](@ref howtocontext) by the functions |
| * listed below. Besides the schema parser functions, it is also possible to use ly_ctx_load_module() which tries to |
| * find the required schema automatically - using #ly_module_imp_clb or automatic search in working directory and in the |
| * context's searchpath. |
| * |
| * Functions List |
| * -------------- |
| * - lys_parse_mem() |
| * - lys_parse_fd() |
| * - lys_parse_path() |
| * - ly_ctx_set_module_imp_clb() |
| * - ly_ctx_load_module() |
| */ |
| |
| /** |
| * @page howtoschemasfeatures YANG Features Manipulation |
| * |
| * The group of functions prefixed by \b lys_features_ are used to access and manipulate with the schema's |
| * features. |
| * |
| * The first two functions are used to access information about the features in the schema. |
| * lys_features_list() provides list of all features defined in the specific schema and its |
| * submodules. Optionally, it can also provide information about the state of all features. |
| * Alternatively, caller can use lys_features_state() function to get state of one specific |
| * feature. |
| * |
| * The remaining two functions, lys_features_enable() and lys_features_disable(), are used |
| * to enable and disable the specific feature (or all via the '`*`' value). By default, when the module |
| * is loaded by libyang parser, all features are disabled. |
| * |
| * To get know, if a specific schema node is currently disabled or enable, the lys_is_disabled() function can be used. |
| * |
| * Note, that the feature's state can affect some of the output formats (e.g. Tree format). |
| * |
| * Functions List |
| * -------------- |
| * - lys_features_list() |
| * - lys_features_enable() |
| * - lys_features_disable() |
| * - lys_features_state() |
| * - lys_is_disabled() |
| */ |
| |
| /** |
| * @page howtoschemaplugins YANG Extension and User Type Support |
| * |
| * Extensions and user types are supported in the form of **plugins**. These are loaded from the plugin directory |
| * (`LIBDIR/libyang/`) whenever a context is created. However, the list of plugins can be refreshed manually by ly_load_plugins(). |
| * The extension plugin directory path (default `LIBDIR/libyang/extensions/`) can be change via the |
| * `LIBYANG_EXTENSIONS_PLUGINS_DIR` environment variable and similarly the user type directory (default `LIBDIR/libyang/user_types/`) |
| * via `LIBYANG_USER_TYPES_PLUGINS_DIR`. Note, that unavailable plugins are not removed, only |
| * any new plugins are loaded. Also note that the availability of new plugins does not affect the current schemas in the |
| * contexts, they are applied only to the newly parsed schemas. |
| * |
| * The plugins list can be cleaned by ly_clean_plugins(). However, since various contexts (respectively their |
| * schemas) can link to the plugins, the cleanup is successful only when there is no remaining context. |
| * |
| * @section extensions Extensions |
| * |
| * YANG provides extensions as a mechanism how to add new statements into the language. Since they are very generic - |
| * extension instance can appear anywhere, they can contain any other YANG statement including extension instances and |
| * their specification has a form of the description text, it is very challenging for libyang to provide working and |
| * useful implementation. Therefore, you can reach some limitation regarding the extensions support, but the common |
| * use cases should be covered and supported. |
| * |
| * Since libyang does not understand human text, it is not possible to get the complete defintion of the extension from |
| * its description statement. Therefore, libyang allows the schema authors to provide @link extplugins extension |
| * plugin@endlink that provides information from the extension description to libyang. |
| * |
| * Here are some notes about the implementation of the particular YANG extensions features |
| * |
| * - Extension instance can appear anywhere |
| * This is completely supported. In addition, the extension plugins are allowed to provide callback function to |
| * check if the extension instance is actually allowed to be instantiated as a substatement of the particular node. |
| * In some case the extension instance is not stored in the libyang structures inside the statement it is |
| * instantiated since some statements (such as description, position and several others listed as #LYEXT_SUBSTMT) are |
| * not stored as a structure, but directly as a value. The extension instances of such statements are then actually |
| * stored besides the extension instances of the parent structure (e.g. in ::lys_type_bit in case of position's |
| * extension instances). These extension instances are indicated by the ::lys_ext_instance#insubstmt value which |
| * refers (sometimes in combination with ::lys_ext_instance#insubstmt_index) to the substatement where the particular |
| * extension is actually instantiated. |
| * |
| * - Extension instance can contain any other YANG statement |
| * This is supported with exceptions - the list of YANG statements is defined as #LY_STMT enumeration with the |
| * description if the specific statement can appear as an extension instance substatement or if there is some |
| * limitation regarding its cardinality. It also specifies how the specific statement is stored in the extension |
| * instance (which data type or structure is used). In some cases, like `include` or `yang-version` statements, it |
| * make no sense to have them inside an extension instance, so they are not supported by libyang. |
| * |
| * The list of allowed substatement for the specific extension instances is provided by the extension plugin. Besides |
| * the list of substatement, the plugin also specifies where the data are stored and the cardinality for each |
| * substatement. Other extension instances as an extension instance substatements are always allowed. Note, that if |
| * there is no extension plugin defined or if the list of the allowed substatements is empty, no substatement (except |
| * extension instances) is allowed. |
| * |
| * There are several extension types (enumerated as #LYEXT_TYPE) according to their purpose and content: |
| * |
| * - #LYEXT_FLAG - simple extension with no content (no substatement is allowed). The extension instance serves just as |
| * a flag with or without an argument and its value. The example of such an extension is NACM's __default-deny-write__ |
| * or __default-deny-all__. This is the default type of extension for the case there is no extension plugin available |
| * for the specific extension. Extension instances of this type are represented as ::lys_ext_instance. |
| * |
| * - #LYEXT_COMPLEX - complex extension with content. The specific rules for the content and how it is stored in the |
| * extension instance structure is specified by the plugin. Extension instances of this type are represented as |
| * ::lys_ext_instance_complex. |
| * |
| * Note that the ::lys_ext_instance structure serves as a generic structure for all extension instances. In case the |
| * ::lys_ext_instance#ext_type is set to a different value than #LYEXT_FLAG, the structure can be cast to the particular |
| * extension instance structure to access the type-specific members. |
| * |
| * @subsection extplugins Extension Plugins |
| * |
| * Extension plugins provide more detailed information about the extension in a understandable form for libyang. These |
| * information is usually provided in a text form in the extension's description statement. libyang provides several |
| * plugins for the common IETF extensions (NACM, Metadata, ...) that can be used as a code examples for other |
| * extensions. |
| * |
| * There are several types of extension plugins which corresponds to the extension types: |
| * |
| * - ::lyext_plugin - the plugin for a simple extensions of type #LYEXT_FLAG. The plugin is supposed to provide |
| * callbacks for: |
| * + @link lyext_check_position_clb checking extension position @endlink (if the extension instance can be instantiated |
| * in a particular parent) |
| * + @link lyext_check_inherit_clb deciding if the extension is supposed to be inherited @endlink |
| * (see #LYEXT_OPT_INHERIT). Note that the inherited extension instances are available in the libyang data |
| * structures, but they are not part of the schema so they are not printed into the schema output formats. |
| * + @link lyext_check_result_clb checking the result @endlink, the callback is called when the schema is completely |
| * parsed and all the data are available for the final (possibly complex) checking (or modification) |
| * - ::lyext_plugin_complex - the plugin for the complex extension instances (#LYEXT_COMPLEX). The structure extends |
| * the ::lyext_plugin structure by: |
| * + instance_size - the overall size of the ::lyext_plugin_complex structure to allocate. |
| * The substatement list is flexible array, so the size of the plugin structure depends on the content of the array. |
| * + substmt - the list of the allowed substatements to the extension instance, besides the substatement id, it |
| * also specifies its cardinality and the specific position in the ::lys_ext_instance_complex where the data are |
| * stored (as offset to the ::lys_ext_instance_complex#content member). The way how the data are stored is |
| * specified descriptions of #LY_STMT values. |
| * |
| * @subsection howtoschemametadata Metadata Support |
| * |
| * YANG Metadata annotations are defined in [RFC 7952](https://tools.ietf.org/html/rfc6243) as YANG extension. In |
| * practice, it allows to have XML attributes (there is also a special encoding for JSON) in YANG modeled data. |
| * libyang does not allow to have any XML attribute without the appropriate annotation definition describing the |
| * data as it is done e.g. for leafs. When an attribute without a matching annotation definition is found in the |
| * input data, it is silently dropped (with warning) or an error is reported in case the #LYD_OPT_STRICT parser |
| * option is provided to the [parser function](@ref howtodataparsers). |
| * |
| * There are some XML attributes, described by [YANG](https://tools.ietf.org/html/rfc7951) and |
| * [NETCONF](https://tools.ietf.org/html/rfc6241) specifications, which are not defined as annotations, but libyang |
| * implements them this way. In case of attributes in the YANG namespace (`insert`, `value` and `key` attributes |
| * for the NETCONF edit-config operation), they are defined in special libyang's internal module `yang`, which is |
| * available in each context and the content of this schema can be printed via |
| * [schema printers](@ref howtoschemasprinters). |
| * |
| * In case of the attributes described in [NETCONF specification](https://tools.ietf.org/html/rfc6241), the libyang's |
| * annotations structures are hidden and cannot be printed despite, internally, they are part of the `ietf-netconf`'s |
| * schema structure. Therefore, these attributes are available only when the `ietf-netconf` schema is loaded in the |
| * context. The definitions of these annotations are as follows: |
| * |
| * md:annotation operation { |
| * type enumeration { |
| * enum merge; |
| * enum replace; |
| * enum create; |
| * enum delete; |
| * enum remove; |
| * } |
| * } |
| * |
| * md:annotation type { |
| * type enumeration { |
| * enum subtree; |
| * enum xpath { |
| * if-feature "nc:xpath"; |
| * } |
| * } |
| * } |
| * |
| * md:annotation select { |
| * type string; |
| * } |
| * |
| * Note, that, following the specification, |
| * - the `type` and `select` XML attributes are supposed to be unqualified (without namespace) and that |
| * - the `select`'s content is XPath and it is internally transformed by libyang into the format where the |
| * XML namespace prefixes are replaced by the YANG module names. |
| * |
| * @section usertypes User Types |
| * |
| * Using this plugin mechanism, it is also possible to define what can be called **user types**. Values are |
| * always stored as a string in addition to being in a #lyd_val union. It is possible to customize how |
| * the value is stored in the union using a #lytype_store_clb callback. |
| * |
| * Generally, it is meant for storing certain types more effectively. For instance, when working with **ipv4-address** |
| * from the *ietf-inet-types* model, an application will most likely use the address in a binary form, not as a string. |
| * So, in the callback the value is simply transformed into the desired format and saved into #lyd_val value. However, |
| * the callback is allowed to store anything in the union. Another example, if there are many strings being created and |
| * handled, is to store the string length instead having 2 pointers to the same string. |
| * |
| * @subsection typeplugins User Type Plugins |
| * |
| * There is a simple example user type plugin in `src/user_types` that is not compiled nor installed. |
| * |
| * - ::lytype_plugin_list - plugin is supposed to provide callbacks for: |
| * + @link lytype_store_clb storing the value itself @endlink |
| * + freeing the stored value (optionally, if the store callback allocates memory) |
| * |
| * Functions List |
| * -------------- |
| * - lys_ext_instance_presence() |
| * - lys_ext_instance_substmt() |
| * - ly_load_plugins() |
| * - ly_clean_plugins() |
| */ |
| |
| /** |
| * @page howtoschemasprinters Printing Schemas |
| * |
| * Schema printers allows to serialize internal representation of a schema module in a specific format. libyang |
| * supports the following schema formats for printing: |
| * |
| * - YANG |
| * |
| * Basic YANG schemas format described in [RFC 6020](http://tools.ietf.org/html/rfc6020) and |
| * [RFC 7951](http://tools.ietf.org/html/rfc7951) (so both YANG 1.0 and YANG 1.1 versions are supported). |
| * |
| * - YIN |
| * |
| * Alternative XML-based format to YANG - YANG Independent Notation. The details can be found in |
| * [RFC 6020](http://tools.ietf.org/html/rfc6020#section-11) and |
| * [RFC 7951](http://tools.ietf.org/html/rfc7951#section-13). |
| * |
| * - Tree |
| * |
| * Simple tree structure of the module where each node is printed as: |
| * |
| * <status> <flags> <name> <opts> <type> <if-features> |
| * |
| * - `<status>` is one of: |
| * - `+` for current |
| * - `x` for deprecated |
| * - `o` for obsolete |
| * |
| * - `<flags>` is one of: |
| * - `rw` for configuration data |
| * - `ro` for status data |
| * - `-x` for RPCs |
| * - `-n` for Notification |
| * |
| * - `<name>` is the name of the node |
| * - `(<name>)` means that the node is a choice node |
| * - `:(<name>)` means that the node is a case node |
| * - if the node is augmented into the tree from another module, it is printed with the module name as |
| * `<module-name>:<name>`. |
| * |
| * - `<opts>` is one of: |
| * - `?` for an optional leaf or choice |
| * - `!` for a presence container |
| * - `*` for a leaf-list or list |
| * - `[<keys>]` for a list's keys |
| * |
| * - `<type>` is the name of the type for leafs and leaf-lists |
| * - if there is a default value defined, it is printed within angle brackets `<default-value>` |
| * - if the type is a leafref, the type is printed as -> TARGET` |
| * |
| * - `<if-features>` is the list of features this node depends on, printed within curly brackets and |
| * a question mark `{...}?` |
| * |
| * |
| * - Info |
| * |
| * Detailed information about the specific node in the schema tree. |
| * It allows to print information not only about a specific module, but also about its specific part: |
| * |
| * - absolute-schema-nodeid |
| * |
| * e.g. \a `/modules/module-set-id` in \a `ietf-yang-library` module |
| * |
| * - <b>typedef/</b>typedef-name |
| * |
| * e.g. \a `typedef/revision-identifier` in \a `ietf-yang-library` module |
| * |
| * - <b>feature/</b>feature-name |
| * |
| * e.g. \a `feature/ssh` in \a `ietf-netconf-server` module |
| * |
| * - <b>grouping/</b>grouping-name/descendant-schema-nodeid |
| * |
| * e.g. \a `grouping/module` or \a `grouping/module/module/submodules` in \a `ietf-yang-library` module |
| * |
| * - <b>type/</b>leaf-or-leaflist |
| * |
| * e.g. \a `type/modules/module-set-id` in \a `ietf-yang-library` module |
| * |
| * Printer functions allow to print to the different outputs including a callback function which allows caller |
| * to have a full control of the output data - libyang passes to the callback a private argument (some internal |
| * data provided by a caller of lys_print_clb()), string buffer and number of characters to print. Note that the |
| * callback is supposed to be called multiple times during the lys_print_clb() execution. |
| * |
| * Functions List |
| * -------------- |
| * - lys_print_mem() |
| * - lys_print_fd() |
| * - lys_print_file() |
| * - lys_print_clb() |
| */ |
| |
| /** |
| * @page howtodata Data Instances |
| * |
| * All data nodes in data trees are connected with their schema node - libyang is not able to represent data of an |
| * unknown schema. |
| * |
| * Connected to the aforementioned, it is important to mention that there are several kinds of data trees libyang |
| * can work with. Except for a standard full data tree and configuration data tree, there are trees specific for use |
| * in NETCONF, which are \<get\> or \<get-config\> replies, \<edit-config\> input content, generic RPC/action request, |
| * RPC/action reply, or a notification. |
| * |
| * Special care is needed when working with action input and RPC/action output, because in these cases the libyang data |
| * tree does not match the actual data tree NETCONF expects. |
| * |
| * <b>Action input</b> differentiates from a standard RPC that the child of \<rpc\> element is not the specific RPC |
| * request being sent, but a special \<action\> element in the base YANG namespace. It is expected to be present when |
| * parsing an action input and can optionally be included when the action is printed. |
| * |
| * As for <b>RPC output</b>, NETCONF expects the output parameters as direct children of the \<rpc-reply\> element. |
| * However, libyang encapsulates these parameters in the specific RPC request container. Same as before, it is expected |
| * to be without this container when parsing and can be printed out. |
| * |
| * Lastly, <b>action output</b> is almost similar to RPC output and in NETCONF you actually cannot distinguish them, |
| * but in case of action output, libyang puts all the output parameters under the action container, which is also |
| * just a child to all the schema tree ancestors up to the schema top-level, just like in an action input. Same applies |
| * even in this case, parsed data should be only the output parameters, you can decide how to print it. |
| * |
| * So, you do not have to use any special flag when you want to print the data tree the way libyang internally stores |
| * it, although you will not be able to parse it back, as was mentioned in the paragraphs above. To print data in the |
| * way NETCONF and libyang expects them to be, use #LYP_NETCONF flag for any printing function. |
| * |
| * Please, continue reading a specific subsection or go through all the subsections if you are a new user of libyang. |
| * |
| * - @subpage howtodataparsers |
| * - @subpage howtodatamanipulators |
| * - @subpage howtodatavalidation |
| * - @subpage howtodatawd |
| * - @subpage howtodataprinters |
| * |
| * \note API for this group of functions is described in the [Data Instances module](@ref datatree). |
| * |
| * Functions List (not assigned to above subsections) |
| * -------------------------------------------------- |
| * - lyd_find_instance() |
| * - lyd_find_xpath() |
| * - lyd_leaf_type() |
| */ |
| |
| /** |
| * @page howtodataparsers Parsing Data |
| * |
| * Data parser allows to read instances from a specific format. libyang supports the following data formats: |
| * |
| * - XML |
| * |
| * Original data format used in NETCONF protocol. XML mapping is part of the YANG specification |
| * ([RFC 6020](http://tools.ietf.org/html/rfc6020)). |
| * |
| * - JSON |
| * |
| * The alternative data format available in RESTCONF protocol. Specification of JSON encoding of data modeled by YANG |
| * can be found in [this draft](https://tools.ietf.org/html/draft-ietf-netmod-yang-json-05). |
| * |
| * Besides the format of input data, the parser functions accepts additional [options](@ref parseroptions) to specify |
| * how the input data should be processed. |
| * |
| * In contrast to the schema parser, data parser also accepts empty input data if such an empty data tree is valid |
| * according to the schemas in the libyang context. |
| * |
| * If a node from a schema, which is not present in the context or is not implemented, is parsed, a callback set by |
| * ly_ctx_set_module_data_clb() is called and this way the application is given the opportunity to add this schema into |
| * the context or change its conformance before the parsing would fail. |
| * |
| * In case of XML input data, there is one additional way to parse input data. Besides parsing the data from a string |
| * in memory or a file, caller is able to build an XML tree using [libyang XML parser](@ref howtoxml) and then use |
| * this tree (or a part of it) as input to the lyd_parse_xml() function. |
| * |
| * Functions List |
| * -------------- |
| * - lyd_parse_mem() |
| * - lyd_parse_fd() |
| * - lyd_parse_path() |
| * - lyd_parse_xml() |
| */ |
| |
| /** |
| * @page howtodatamanipulators Manipulating Data |
| * |
| * There are many functions to create or modify an existing data tree. You can add new nodes, reconnect nodes from |
| * one tree to another (or e.g. from one list instance to another) or remove nodes. The functions doesn't allow you |
| * to put a node to a wrong place (by checking the module), but not all validation checks can be made directly |
| * (or you have to make a valid change by multiple tree modifications) when the tree is being changed. Therefore, |
| * there is lyd_validate() function supposed to be called to make sure that the current data tree is valid. If |
| * working with RPCs, they are invalid also in case the data nodes are not ordered according to the schema, which |
| * you can fix easily with lyd_schema_sort(). Note, that not performing validation after some data tree changes |
| * can cause failure of various libyang functions later. All functions performing data tree changes are marked |
| * with the __PARTIAL CHANGE__ flag in their documentation meaning they leave at least partly non-validated data tree. |
| * |
| * Creating data is generally possible in two ways, they can be combined. You can add nodes one-by-one based on |
| * the node name and/or its parent (lyd_new(), \b lyd_new_anydata_*(), lyd_new_leaf(), and their output variants) or |
| * address the nodes using a simple XPath addressing (lyd_new_path()). The latter enables to create a whole path |
| * of nodes, requires less information about the modified data, and is generally simpler to use. The path format |
| * specifics can be found [here](@ref howtoxpath). |
| * |
| * Working with two data subtrees can also be performed two ways. Usually, you would use lyd_insert*() functions. |
| * They are generally meant for simple inserts of a node into a data tree. For more complicated inserts and when |
| * merging 2 trees use lyd_merge(). It offers additional options and is basically a more powerful insert. |
| * |
| * Also remember, that when you are creating/inserting a node, all the objects in that operation must belong to the |
| * same context. |
| * |
| * Modifying the single data tree in multiple threads is not safe. |
| * |
| * Functions List |
| * -------------- |
| * - lyd_dup() |
| * - lyd_dup_to_ctx() |
| * - lyd_change_leaf() |
| * - lyd_insert() |
| * - lyd_insert_sibling() |
| * - lyd_insert_before() |
| * - lyd_insert_after() |
| * - lyd_insert_attr() |
| * - lyd_merge() |
| * - lyd_merge_to_ctx() |
| * - lyd_new() |
| * - lyd_new_anydata() |
| * - lyd_new_leaf() |
| * - lyd_new_path() |
| * - lyd_new_output() |
| * - lyd_new_output_anydata() |
| * - lyd_new_output_leaf() |
| * - lyd_list_pos() |
| * - lyd_schema_sort() |
| * - lyd_unlink() |
| * - lyd_free() |
| * - lyd_free_attr() |
| * - lyd_free_withsiblings() |
| */ |
| |
| /** |
| * @page howtodatavalidation Validating Data |
| * |
| * By default, the represented data are supposed to represent a full YANG datastore content. So if a schema declares |
| * some mandatory nodes, despite configuration or status, the data are supposed to be present in the data tree being |
| * loaded or validated. However, it is possible to specify other kinds of data (see @ref parseroptions) allowing some |
| * exceptions to the validation process. |
| * |
| * Data validation is performed implicitly to the input data processed by the parser (\b lyd_parse_*() functions) and |
| * on demand via the lyd_validate() function. The lyd_validate() is supposed to be used when a (complex or simple) |
| * change is done on the data tree (via a combination of \b lyd_change_*(), \b lyd_insert*(), \b lyd_new*(), |
| * lyd_unlink() and lyd_free() functions). |
| * |
| * Part of data validation is resolving leafrefs and instance-identifiers. Leafrefs are resolved only when a change occured |
| * in the data tree that could have broken the link. However, as instance-identifiers can point to any node whatsoever |
| * without an import, it would not be effective to store metadata as in the case of leafrefs. That is why they are resolved |
| * during every validation. Also, for the same reason, it can easily happen that when parsing/validating data with |
| * an instance-identifier, it will target a remote node, whose schema is not currently present in the context. To handle |
| * this case, a callback should be set using ly_ctx_set_module_data_clb(), which can load the schema when required. |
| * |
| * Must And When Conditions Accessible Tree |
| * ---------------------------------------- |
| * |
| * In YANG 1.1, there can be \b must and/or \b when expressions in RPC/action input or output, or in notifications that |
| * require access to the configuration datastore and/or state data. Normally, when working with any of the aforementioned |
| * data trees, they must contain only the RPC/action/notification itself, without any additional configuration or state |
| * data. So how can then these conditions be verified during validation? |
| * |
| * There is an option to pass this additional data tree to all the functions that perform \b must and \b when condition |
| * checking (\b lyd_parse_*() and lyd_validate()). Also, there are 2 flags of \b struct lys_node that |
| * mark schema nodes that include paths that require foreign nodes (outside their subtree) for their evaluation. #LYS_XPATH_DEP |
| * marks nodes with such must and/or when expressions, #LYS_LEAFREF_DEP with such a leafref. |
| * The subtree root is always the particular operation data node (for RPC it is the RPC data node and all |
| * the input or output nodes as its children and similarly for action and notification). Note that for action and |
| * not-top-level notification this means that all their parents are not considered as belonging to their subtree even though |
| * they are included in their data tree and must be present for the operation validation to pass. The reason for this is that if |
| * there are any lists in those parents, we cannot know if there are not some other instances of them in the standard |
| * data tree in addition to the one used in the action/notification invocation. |
| * |
| * There were 2 ways of using this mechanism envisioned (explained below), but you can combine or modify them. |
| * |
| * ### Fine-grained Data Retrieval ### |
| * |
| * This approach is recommended when you do not maintain a full configuration data tree with state data at all times. |
| * |
| * Firstly, you should somehow learn that the operation data tree you are currently working with includes some schema |
| * node instances that have conditions that require foreign data. You can either know this about every operation beforehand |
| * or you go through all the schema nodes looking for the flags #LYS_XPATH_DEP and #LYS_LEAFREF_DEP. Then you should use lys_node_xpath_atomize() |
| * to retrieve all XPath condition dependencies (in the form of schema nodes) outside the operation subtree. You will likely |
| * want to use the flag #LYXP_NO_LOCAL to get rid of all the nodes from inside the subtree (you should already have those). |
| * The last thing to do is to build a data tree that includes at least all the instances of the nodes obtained from lys_node_xpath_atomize() |
| * (it will be expected). Then you pass this tree to the validation and it should now have access to all the nodes that |
| * can potentially affect the XPath evaluation and no other. |
| * |
| * ### Maintaining Configuration And State Data Tree ### |
| * |
| * If you have a full data tree with state data available for the validation process then it is quite simple (compared |
| * to the first approach). You can simply always pass it to validation of these operations and in cases it is not required |
| * (no nodes with conditions traversing foreign nodes) only a negligible amount of redundant work is performed and you can |
| * skip the process of learning whether it is required or not. |
| * |
| * Functions List |
| * -------------- |
| * - lyd_validate() |
| */ |
| |
| /** |
| * @page howtodatawd Default Values |
| * |
| * libyang provides support for work with default values as defined in [RFC 6243](https://tools.ietf.org/html/rfc6243). |
| * This document defines 4 modes for handling default nodes in a data tree, libyang adds the fifth mode: |
| * - \b explicit - Only the explicitly set configuration data. But in the case of status data, missing default |
| * data are added into the tree. In libyang, this mode is represented by #LYP_WD_EXPLICIT option. |
| * - \b trim - Data nodes containing the schema default value are removed. This mode is applied using #LYP_WD_TRIM option. |
| * - \b report-all - All the missing default data are added into the data tree. This mode is represented by |
| * #LYP_WD_ALL option. |
| * - \b report-all-tagged - In this case, all the missing default data are added as in case of the `report-all` mode, |
| * but additionally all the nodes (existing as well as added) containing the schema default value |
| * are tagged (see the note below). libyang uses #LYP_WD_ALL_TAG option for this mode. |
| * - \b report-implicit-tagged - The last mode is similar to the previous one, except only the added nodes are tagged. |
| * This is the libyang's extension and it is represented by #LYP_WD_IMPL_TAG option. |
| * |
| * libyang automatically adds/maintain the default nodes when a data tree is being parsed or validated. Note, that in a |
| * modified data tree (via e.g. lyd_insert() or lyd_free()), some of the default nodes can be missing or they can be |
| * present by mistake. Such a data tree is again corrected during the next lyd_validate() call. |
| * |
| * The implicit (default) nodes, created by libyang, are marked with the ::lyd_node#dflt flag which applies to the |
| * leafs and leaf-lists. In case of containers, the flag means that the container holds only a default node(s) or it |
| * is an empty container (according to YANG 1.1 spec, all such containers are part of the accessible data tree). |
| * |
| * The presence of the default nodes during the data tree lifetime is affected by the LYD_OPT_ flag used to |
| * parse/validate the tree: |
| * - #LYD_OPT_DATA - all the default nodes are present despite they are configuration or status nodes |
| * - #LYD_OPT_CONFIG - only the configuration data nodes are added into the tree |
| * - #LYD_OPT_GET, #LYD_OPT_GETCONFIG, #LYD_OPT_EDIT - no default nodes are added |
| * - #LYD_OPT_RPC, #LYD_OPT_RPCREPLY, #LYD_OPT_NOTIF - the default nodes from the particular subtree are added |
| * |
| * The with-default modes described above are supported when the data tree is being printed with the |
| * [LYP_WD_ printer flags](@ref printerflags). Note, that in case of #LYP_WD_ALL_TAG and #LYP_WD_IMPL_TAG modes, |
| * the XML/JSON attributes are printed only if the context includes the ietf-netconf-with-defaults schema. Otherwise, |
| * these modes have the same result as #LYP_WD_ALL. The presence of empty containers (despite they were added explicitly |
| * or implicitly as part of accessible data tree) depends on #LYP_KEEPEMPTYCONT option. |
| * |
| * To get know if the particular leaf or leaf-list node contains default value (despite implicit or explicit), you can |
| * use lyd_wd_default() function. |
| * |
| * Functions List |
| * -------------- |
| * - lyd_wd_default() |
| * |
| * - lyd_parse_mem() |
| * - lyd_parse_fd() |
| * - lyd_parse_path() |
| * - lyd_parse_xml() |
| * - lyd_validate() |
| * - lyd_print_mem() |
| * - lyd_print_fd() |
| * - lyd_print_file() |
| * - lyd_print_clb() |
| */ |
| |
| /** |
| * @page howtodataprinters Printing Data |
| * |
| * Data printers allows to serialize internal representation of a data tree in a specific format. libyang |
| * supports the following data formats for printing: |
| * |
| * - XML |
| * |
| * Basic format as specified in rules of mapping YANG modeled data to XML in |
| * [RFC 6020](http://tools.ietf.org/html/rfc6020). It is possible to specify if |
| * the indentation (formatting) will be used (by #LYP_FORMAT @ref printerflags "printer option"). |
| * |
| * - JSON |
| * |
| * The alternative data format available in RESTCONF protocol. Specification of JSON encoding of data modeled by YANG |
| * can be found in [this draft](https://tools.ietf.org/html/draft-ietf-netmod-yang-json-05).It is possible to specify |
| * if the indentation (formatting) will be used (by #LYP_FORMAT @ref printerflags "printer option"). |
| * |
| * Printer functions allow to print to the different outputs including a callback function which allows caller |
| * to have a full control of the output data - libyang passes to the callback a private argument (some internal |
| * data provided by a caller of lyd_print_clb()), string buffer and number of characters to print. Note that the |
| * callback is supposed to be called multiple times during the lyd_print_clb() execution. |
| * |
| * To print the data tree with default nodes according to the with-defaults capability defined in |
| * [RFC 6243](https://tools.ietf.org/html/rfc6243), check the [page about the default values](@ref howtodatawd). |
| * |
| * Also, to print the data in NETCONF format, use the #LYP_NETCONF flag. More information can be found on the page |
| * @ref howtodata. |
| * |
| * Functions List |
| * -------------- |
| * - lyd_print_mem() |
| * - lyd_print_fd() |
| * - lyd_print_file() |
| * - lyd_print_clb() |
| */ |
| |
| /** |
| * @page howtoxpath XPath Addressing |
| * |
| * Internally, XPath evaluation is performed on __when__ and __must__ conditions in the schema. For that almost |
| * a full XPath 1.0 evaluator was implemented. In YANG models you can also find paths identifying __augment__ |
| * targets, __leafref__ targets, and trivial paths in __choice default__ and __unique__ statements argument. |
| * The exact format of all those paths can be found in the relevant RFCs. Further will only be discussed |
| * paths that are used directly in libyang API functions. |
| * |
| * Schema |
| * ====== |
| * |
| * Regarding identifying schema nodes, we use a slightly modified version of YANG __augment__ target path: |
| * - strictly speaking, most XPath expressions are not accepted, only simple paths (no predicates, |
| * numbers, literals, operators, ...), |
| * - whenever a prefix is used for a node, it is not the import prefix, but the __module name__ itself, |
| * - __current module__ is specified separately for _absolute_ paths and is the module of the start |
| * (current) node for _relative_ paths, |
| * - unprefixed nodes all use the prefix of the __current module__ so all nodes from other modules than |
| * the __current module__ _MUST_ have prefixes, |
| * - nodes from the __current module__ _MAY_ have prefixes, |
| * |
| * Examples |
| * -------- |
| * |
| * - get all top-level nodes of the __module-name__ |
| * |
| * /module-name:* |
| * |
| * - get all the descendants of __container__ (excluding __container__) |
| * |
| * /module-name:container//\asterisk |
| * |
| * - get __aug-leaf__, which was added to __module-name__ from an augment module __augment-module__ |
| * |
| * /module-name:container/container2/augment-module:aug-cont/augment-module:aug-leaf |
| * |
| * Functions List |
| * -------------- |
| * - lys_find_path() |
| * - lys_path() |
| * - ly_path_data2schema() |
| * |
| * |
| * Data |
| * ==== |
| * |
| * As for paths evaluated on YANG data, we opted for standardized JSON paths ([RFC 7951](https://tools.ietf.org/html/rfc7951#section-6.11)). Summarized, it follows these conventions: |
| * - generally, you can use almost a full XPath in these paths where it makes sense, but only data nodes (node sets) |
| * will always be returned (except for paths, predicates are mostly used), |
| * - as per the specification, prefixes are actually __module names__, |
| * - also in the specification, for _absolute_ paths, the first (leftmost) node _MUST_ have a prefix, |
| * - for _relative_ paths, you specify the __context node__, which then acts as a parent for the first node in the path, |
| * - nodes always inherit their module (prefix) from their __parent node__ so whenever a node is from a different |
| * module than its parent, it _MUST_ have a prefix, |
| * - nodes from the same module as their __parent__ _MUST NOT_ have a prefix, |
| * - different from schema paths, non-data nodes (choice, case, uses, input, output) are skipped and not included |
| * in the path. |
| * |
| * Examples |
| * -------- |
| * |
| * - get __list__ instance with __key1__ of value __1__ and __key2__ of value __2__ (this can return more __list__ instances if there are more keys than __key1__ and __key2__) |
| * |
| * /module-name:container/list[key1='1'][key2='2'] |
| * |
| * - get __leaf-list__ instance with the value __val__ |
| * |
| * /module-name:container/leaf-list[.='val'] |
| * |
| * - get __aug-list__ with __aug-list-key__, which was added to __module-name__ from an augment module __augment-module__ |
| * |
| * /module-name:container/container2/augment-module:aug-cont/aug-list[aug-list-key='value'] |
| * |
| * Functions List |
| * -------------- |
| * - lyd_find_path() |
| * - lyd_new_path() |
| * - lyd_path() |
| * - lys_data_path() |
| * - ly_ctx_get_node() |
| * - ly_ctx_find_path() |
| * |
| */ |
| |
| /** |
| * @page howtoxml libyang XML Support |
| * |
| * libyang XML parser is able to parse XML documents. The main purpose is to load data modeled by YANG. However, it can |
| * be used as a standalone XML parser with the following limitations in comparison to a full-featured XML parsers: |
| * - comments are ignored |
| * - Doctype declaration is ignored |
| * - CData sections are ignored |
| * - Process Instructions (PI) are ignored |
| * |
| * The API is designed to almost only read-only access. You can simply load XML document, go through the tree as |
| * you wish and dump the tree to an output. The only "write" functions are lyxml_free() and lyxml_unlink() to remove |
| * part of the tree or to unlink (separate) a subtree. |
| * |
| * XML parser is used internally by libyang for parsing YIN schemas and data instances in XML format. |
| * |
| * \note API for this group of functions is described in the [XML Parser module](@ref xmlparser). |
| * |
| * Functions List |
| * -------------- |
| * - lyxml_parse_mem() |
| * - lyxml_parse_path() |
| * - lyxml_get_attr() |
| * - lyxml_get_ns() |
| * - lyxml_print_mem() |
| * - lyxml_print_fd() |
| * - lyxml_print_file() |
| * - lyxml_print_clb() |
| * - lyxml_unlink() |
| * - lyxml_free() |
| */ |
| |
| /** |
| * @page howtothreads libyang in Threads |
| * |
| * libyang can be used in multithreaded applications keeping in mind the following rules: |
| * - libyang context manipulation (adding new schemas) is not thread safe and it is supposed to be done in a main |
| * thread before any other work with context, schemas or data instances. Destroying the context is supposed to |
| * be done when no other thread accesses context, schemas nor data trees, |
| * - data parser (\b lyd_parse*() functions) can be used simultaneously in multiple threads (also the returned |
| * #ly_errno is thread safe), |
| * - data manipulation (lyd_new(), lyd_insert(), lyd_unlink(), lyd_free() and many other |
| * functions) a single data tree is not thread safe, |
| * - data printing of a single data tree is thread-safe. |
| */ |
| |
| /** |
| * @page howtologger Logger |
| * |
| * There are 4 verbosity levels defined as ::LY_LOG_LEVEL. The level can be |
| * changed by the ly_verb() function. By default, the verbosity level is |
| * set to #LY_LLERR value. |
| * |
| * All the logging operations are tied to the specific **thread** and **context**. |
| * The default behaviour is that the last message (error or warning, verbose and debug |
| * messages are never stored) is always stored and can be accessed using ly_errmsg(). On error, |
| * #ly_errno is set. If that was a validation error (#ly_errno is set to #LY_EVALID), |
| * also validation error code (via ly_vecode()) and path to the error node (via ly_errpath()) are available. |
| * |
| * For some specific cases, a YANG schema can define error message and/or error tag (mainly for |
| * use in NETCONF). If a message is set, it is provided via ly_errmsg(). If a tag is set in schema, |
| * it is available via ly_errapptag() (if not set, the returned string is empty). |
| * |
| * By default, all libyang messages are printed to `stderr`. However, the caller is able to set their own logging |
| * callback function. In that case, instead of printing messages, libyang passes error level, message and path |
| * (if any) to the caller's callback function. In case of error level, the message and path are still |
| * automatically stored and available via the functions and macros described above. |
| * |
| * This is the basic way of working with errors but another, more sophisticated is also available. With ly_log_options() |
| * you can modify what is done with all the messages. Default flags are #LY_LOLOG and #LY_LOSTORE_LAST so that messages |
| * are logged and the last one is stored. If you set the flag #LY_LOSTORE, all the messages will be stored. Be careful |
| * because unless you regularly clean them, the error list will grow indefinitely. With ly_err_first() you can retrieve |
| * the first generated error structure ly_err_item. It is a linked-list so you can get next errors using the **next** pointer. |
| * Being processed (for instance printed with ly_err_print()), you can then free them with ly_err_clean(). |
| * |
| * \note API for this group of functions is described in the [logger module](@ref logger). |
| * |
| * Functions List |
| * -------------- |
| * - ly_verb() |
| * - ly_set_log_clb() |
| * - ly_get_log_clb() |
| * - ly_log_options() |
| * - #ly_errno |
| * - ly_vecode() |
| * - ly_errmsg() |
| * - ly_errpath() |
| * - ly_errapptag() |
| * - ly_err_first() |
| * - ly_err_print() |
| * - ly_err_clean() |
| */ |
| |
| /** |
| * @defgroup context Context |
| * @{ |
| * |
| * Structures and functions to manipulate with the libyang "containers". The \em context concept allows callers |
| * to work in environments with different sets of YANG schemas. More detailed information can be found at |
| * @ref howtocontext page. |
| */ |
| |
| /** |
| * @brief libyang context handler. |
| */ |
| struct ly_ctx; |
| |
| /** |
| * @defgroup contextoptions Context options |
| * @ingroup context |
| * |
| * Options to change context behavior. |
| */ |
| |
| #define LY_CTX_ALLIMPLEMENTED 0x01 /**< All the imports of the schema being parsed are treated implemented. */ |
| #define LY_CTX_TRUSTED 0x02 /**< Handle the schema being parsed as trusted and skip its validation |
| tests. Note that while this option improves performance, it can |
| lead to an undefined behavior if the schema is not correct. */ |
| #define LY_CTX_NOYANGLIBRARY 0x04 /**< Do not internally implement ietf-yang-library module. The option |
| causes that function ly_ctx_info() does not work (returns NULL) until |
| the ietf-yang-library module is loaded manually. While any revision |
| of this schema can be loaded with this option, note that the only |
| revisions implemented by ly_ctx_info() are 2016-04-09 and 2018-01-17. |
| This option cannot be used with ly_ctx_new_yl*() functions. */ |
| |
| /**@} contextoptions */ |
| |
| /** |
| * @brief Create libyang context |
| * |
| * Context is used to hold all information about schemas. Usually, the application is supposed |
| * to work with a single context in which libyang is holding all schemas (and other internal |
| * information) according to which the data trees will be processed and validated. So, the schema |
| * trees are tightly connected with the specific context and they are held by the context internally |
| * - caller does not need to keep pointers to the schemas returned by lys_parse(), context knows |
| * about them. The data trees created with lyd_parse() are still connected with the specific context, |
| * but they are not internally held by the context. The data tree just points and lean on some data |
| * held by the context (schema tree, string dictionary, etc.). Therefore, in case of data trees, caller |
| * is supposed to keep pointers returned by the lyd_parse() and manage the data tree on its own. This |
| * also affects the number of instances of both tree types. While you can have only one instance of |
| * specific schema connected with a single context, number of data tree instances is not connected. |
| * |
| * @param[in] search_dir Directory where libyang will search for the imported or included modules |
| * and submodules. If no such directory is available, NULL is accepted. |
| * @param[in] options Context options, see @ref contextoptions. |
| * |
| * @return Pointer to the created libyang context, NULL in case of error. |
| */ |
| struct ly_ctx *ly_ctx_new(const char *search_dir, int options); |
| |
| /** |
| * @brief Create libyang context according to the content of the given yang-library data. |
| * |
| * This function loads the yang-library data from the file at the given path. If you need |
| * to pass the data as string, use ly_ctx_new_ylmem(). Both functions extend functionality of |
| * ly_ctx_new() by loading modules specified in the ietf-yang-library form into the context |
| * being created. |
| * |
| * The preferred tree model revision is 2018-01-17. However, only the first module-set is processed |
| * and loaded into the context. If there are no matching nodes from this tree, the legacy tree |
| * (originally from model revision 2016-04-09) is processed. |
| * |
| * Note, that the modules are loaded the same way as in case of ly_ctx_load_module(), so the schema |
| * paths in the yang-library data are ignored and the modules are loaded from the context's search |
| * locations. On the other hand, YANG features of the modules are set as specified in the yang-library |
| * data. |
| * |
| * To get yang library data from a libyang context, use ly_ctx_info(). |
| * |
| * @param[in] search_dir Directory where libyang will search for the imported or included modules |
| * and submodules. If no such directory is available, NULL is accepted. |
| * @param[in] path Path to the file containing yang-library data in the specified \p format. |
| * @param[in] format Format of the data in the provided file. |
| * @param[in] options Context options, see @ref contextoptions. |
| * @return Pointer to the created libyang context, NULL in case of error. |
| */ |
| struct ly_ctx *ly_ctx_new_ylpath(const char *search_dir, const char *path, LYD_FORMAT format, int options); |
| |
| /** |
| * @brief Create libyang context according to the content of the given yang-library data. |
| * |
| * This function loads the yang-library data from the given string. If you need to pass the data |
| * as path to a file holding the data, use ly_ctx_new_ylpath(). Both functions extend functionality of |
| * ly_ctx_new() by loading modules specified in the ietf-yang-library form into the context |
| * being created. |
| * |
| * The preferred tree model revision is 2018-01-17. However, only the first module-set is processed |
| * and loaded into the context. If there are no matching nodes from this tree, the legacy tree |
| * (originally from model revision 2016-04-09) is processed. |
| * |
| * Note, that the modules are loaded the same way as in case of ly_ctx_load_module(), so the schema |
| * paths in the yang-library data are ignored and the modules are loaded from the context's search |
| * locations. On the other hand, YANG features of the modules are set as specified in the yang-library |
| * data. |
| * |
| * To get yang library data from a libyang context, use ly_ctx_info(). |
| * |
| * @param[in] search_dir Directory where libyang will search for the imported or included modules |
| * and submodules. If no such directory is available, NULL is accepted. |
| * @param[in] data String containing yang-library data in the specified \p format. |
| * @param[in] format Format of the data in the provided file. |
| * @param[in] options Context options, see @ref contextoptions. |
| * @return Pointer to the created libyang context, NULL in case of error. |
| */ |
| struct ly_ctx *ly_ctx_new_ylmem(const char *search_dir, const char *data, LYD_FORMAT format, int options); |
| |
| /** |
| * @brief Number of internal modules, which are in the context and cannot be removed nor disabled. |
| * @param[in] ctx Context to investigate. |
| * @return Number of internal modules, 0 in case of invalid parameter. |
| */ |
| unsigned int ly_ctx_internal_modules_count(struct ly_ctx *ctx); |
| |
| /** |
| * @brief Add the search path into libyang context |
| * |
| * To reset search paths set in the context, use ly_ctx_unset_searchdirs() and then |
| * set search paths again. |
| * |
| * @param[in] ctx Context to be modified. |
| * @param[in] search_dir New search path to add to the current paths previously set in ctx. |
| * @return EXIT_SUCCESS, EXIT_FAILURE. |
| */ |
| int ly_ctx_set_searchdir(struct ly_ctx *ctx, const char *search_dir); |
| |
| /** |
| * @brief Clean the search path(s) from the libyang context |
| * |
| * @param[in] ctx Context to be modified. |
| * @param[in] index Index of the search path to be removed, use negative value to remove them all. |
| * Correct index value can be checked via ly_ctx_get_searchdirs(). |
| */ |
| void ly_ctx_unset_searchdirs(struct ly_ctx *ctx, int index); |
| |
| /** |
| * @brief Get the NULL-terminated list of the search paths in libyang context. |
| * |
| * @param[in] ctx Context to query. |
| * @return NULL-terminated list (array) of the search paths, NULL if no searchpath was set. |
| */ |
| const char * const *ly_ctx_get_searchdirs(const struct ly_ctx *ctx); |
| |
| /** |
| * @brief Make context to set all the imported modules to be implemented. By default, |
| * if the imported module is not used in leafref's path, augment or deviation, it is |
| * imported and its data tree is not taken into account. |
| * |
| * The same effect is achieved by using #LY_CTX_ALLIMPLEMENTED option when creating new context or parsing |
| * a specific schema. |
| * |
| * Note, that function does not make the currently loaded modules, it just change the |
| * schema parser behavior for the future parsing. This flag can be unset by ly_ctx_unset_allimplemented(). |
| * |
| * @param[in] ctx Context to be modified. |
| */ |
| void ly_ctx_set_allimplemented(struct ly_ctx *ctx); |
| |
| /** |
| * @brief Reverse function to ly_ctx_set_allimplemented(). |
| * |
| * @param[in] ctx Context to be modified. |
| */ |
| void ly_ctx_unset_allimplemented(struct ly_ctx *ctx); |
| |
| /** |
| * @brief Change the schema parser behavior when parsing new schemas forcing it to skip some of the schema |
| * validation checks to improve performance. Note that parsing invalid schemas this way may lead to an |
| * undefined behavior later, e.g. when working with data trees. |
| * |
| * The same effect is achieved by using #LY_CTX_TRUSTED option when creating new context or parsing |
| * a specific schema. |
| * |
| * This flag can be unset by ly_ctx_unset_trusted(). |
| * |
| * @param[in] ctx Context to be modified. |
| */ |
| void ly_ctx_set_trusted(struct ly_ctx *ctx); |
| |
| /** |
| * @brief Reverse function to ly_ctx_set_trusted(). |
| * |
| * @param[in] ctx Context to be modified. |
| */ |
| void ly_ctx_unset_trusted(struct ly_ctx *ctx); |
| |
| /** |
| * @brief Get data of an internal ietf-yang-library module. |
| * |
| * @param[in] ctx Context with the modules. |
| * @return Root data node corresponding to the model, NULL on error. |
| * Caller is responsible for freeing the returned data tree using lyd_free(). |
| */ |
| struct lyd_node *ly_ctx_info(struct ly_ctx *ctx); |
| |
| /** |
| * @brief Iterate over all (enabled) modules in a context. |
| * |
| * @param[in] ctx Context with the modules. |
| * @param[in,out] idx Index of the next module to be returned. Value of 0 starts from the beginning. |
| * @return Next context module, NULL if the last was already returned. |
| */ |
| const struct lys_module *ly_ctx_get_module_iter(const struct ly_ctx *ctx, uint32_t *idx); |
| |
| /** |
| * @brief Iterate over the disabled modules in a context. |
| * |
| * @param[in] ctx Context with the modules. |
| * @param[in,out] idx Index of the next module to be returned. Value of 0 starts from the beginning. |
| * @return Next context module, NULL if the last was already returned. |
| */ |
| const struct lys_module *ly_ctx_get_disabled_module_iter(const struct ly_ctx *ctx, uint32_t *idx); |
| |
| /** |
| * @brief Get pointer to the schema tree of the module of the specified name. |
| * |
| * @param[in] ctx Context to work in. |
| * @param[in] name Name of the YANG module to get. |
| * @param[in] revision Optional revision date of the YANG module to get. If not specified, |
| * the schema in the newest/implemented revision (see \p implemented parameter) is returned if any. |
| * @param[in] implemented In case the revision is not specified, require the implemented module |
| * instead of the newest revision of the module. |
| * @return Pointer to the data model structure, NULL if no schema following the name and |
| * revision requirements is present in the context. |
| */ |
| const struct lys_module *ly_ctx_get_module(const struct ly_ctx *ctx, const char *name, const char *revision, int implemented); |
| |
| /** |
| * @brief Get pointer to the older schema tree to the specified one in the provided context. |
| * |
| * The module is not necessarily from the provided \p ctx. If there are multiple schemas older than the |
| * provided one, the newest of them is returned. |
| * |
| * The function can be used in combination with ly_ctx_get_module() to get all revisions of a module in a context: |
| * \code{.c} |
| * for (mod = ly_ctx_get_module(ctx, name, NULL); mod; mod = ly_ctx_get_module_older(ctx, mod)) { |
| * ... |
| * } |
| * \endcode |
| * |
| * @param[in] ctx Context to work in. |
| * @param[in] module YANG module to compare with |
| * @return Pointer to the data model structure, NULL if no older schema is present in the context. |
| */ |
| const struct lys_module *ly_ctx_get_module_older(const struct ly_ctx *ctx, const struct lys_module *module); |
| |
| /** |
| * @brief Try to find the model in the searchpath of \p ctx and load it into it. If custom missing |
| * module callback is set, it is used instead. |
| * |
| * If there is a possibility that the requested module is already in the context, you should call |
| * the ly_ctx_get_module() first to avoid a lot of work performed by ly_ctx_load_module(). |
| * |
| * @param[in] ctx Context to add to. |
| * @param[in] name Name of the module to load. |
| * @param[in] revision Optional revision date of the module. If not specified, it is |
| * assumed that there is only one model revision in the searchpath (the first matching file |
| * is parsed). |
| * @return Pointer to the data model structure, NULL if not found or some error occured. |
| */ |
| const struct lys_module *ly_ctx_load_module(struct ly_ctx *ctx, const char *name, const char *revision); |
| |
| /** |
| * @brief Callback for retrieving missing included or imported models in a custom way. |
| * |
| * @param[in] mod_name Missing module name. |
| * @param[in] mod_rev Optional missing module revision. |
| * @param[in] submod_name Optional missing submodule name. |
| * @param[in] submod_rev Optional missing submodule revision. |
| * @param[in] user_data User-supplied callback data. |
| * @param[out] format Format of the returned module data. |
| * @param[out] free_module_data Callback for freeing the returned module data. If not set, the data will be left untouched. |
| * @return Requested module data, NULL if the module is supposed to be loaded |
| * using standard mechanisms (searched for in the filesystem), NULL and #ly_errno set if |
| * the callback failed resulting in the module failing to load. |
| */ |
| typedef char *(*ly_module_imp_clb)(const char *mod_name, const char *mod_rev, const char *submod_name, const char *sub_rev, |
| void *user_data, LYS_INFORMAT *format, void (**free_module_data)(void *model_data)); |
| |
| /** |
| * @brief Set missing include or import module callback. It is meant to be used when the models |
| * are not locally available (such as when downloading modules from a NETCONF server), it should |
| * not be required in other cases. |
| * |
| * @param[in] ctx Context that will use this callback. |
| * @param[in] clb Callback responsible for returning the missing model. |
| * @param[in] user_data Arbitrary data that will always be passed to the callback \p clb. |
| */ |
| void ly_ctx_set_module_imp_clb(struct ly_ctx *ctx, ly_module_imp_clb clb, void *user_data); |
| |
| /** |
| * @brief Get the custom callback for missing import/include module retrieval. |
| * |
| * @param[in] ctx Context to read from. |
| * @param[in] user_data Optional pointer for getting the user-supplied callback data. |
| * @return Callback or NULL if not set. |
| */ |
| ly_module_imp_clb ly_ctx_get_module_imp_clb(const struct ly_ctx *ctx, void **user_data); |
| |
| /** |
| * @brief Callback for retrieving missing modules in the context, for which some data was found. |
| * |
| * Either \p name or \p ns is ALWAYS set, but both can also be set. |
| * |
| * @param[in,out] ctx Context with the missing module. |
| * @param[in] name Missing module name. |
| * @param[in] ns Missing module namespace. |
| * @param[in] options Bitmask of LY_MODCLB_* values or 0. |
| * @param[in] user_data User-supplied callback data. |
| * @return Newly added or modified module, NULL on failure. |
| */ |
| typedef const struct lys_module *(*ly_module_data_clb)(struct ly_ctx *ctx, const char *name, const char *ns, |
| int options, void *user_data); |
| |
| /* Module is in the context, but is not implemented, so to continue with the data operation, it must be implemented. */ |
| #define LY_MODCLB_NOT_IMPLEMENTED 0x01 |
| |
| /** |
| * @brief Set the missing data module callback. It will be called when some data is parsed or searched for and their module |
| * is not found in the context or is not implemented. |
| * |
| * @param[in] ctx Context that will use this callback. |
| * @param[in] clb Callback responsible for returning the missing model. |
| * @param[in] user_data Arbitrary data that will always be passed to the callback \p clb. |
| */ |
| void ly_ctx_set_module_data_clb(struct ly_ctx *ctx, ly_module_data_clb clb, void *user_data); |
| |
| /** |
| * @brief Get the missing data module calback. |
| * |
| * @param[in] ctx Context to read from. |
| * @param[in] user_data Optional pointer for getting the user-supplied callbck data. |
| * @return Callback or NULL if not set. |
| */ |
| ly_module_data_clb ly_ctx_get_module_data_clb(const struct ly_ctx *ctx, void **user_data); |
| |
| /** |
| * @brief Get pointer to the schema tree of the module of the specified namespace |
| * |
| * @param[in] ctx Context to work in. |
| * @param[in] ns Namespace of the YANG module to get. |
| * @param[in] revision Optional revision date of the YANG module to get. If not specified, |
| * the schema in the newest/implemented revision (see \p implemented parameter) is returned if any. |
| * @param[in] implemented In case the revision is not specified, require the implemented module |
| * instead of the newest revision of the module. |
| * @return Pointer to the data model structure, NULL if no schema following the namespace and |
| * revision requirements is present in the context. |
| */ |
| const struct lys_module *ly_ctx_get_module_by_ns(const struct ly_ctx *ctx, const char *ns, const char *revision, int implemented); |
| |
| /** |
| * @brief Get submodule of a main module. |
| * |
| * If you already have the pointer to the submodule's main module, use ly_ctx_get_submodule2() instead. |
| * |
| * @param[in] ctx Context to work in. |
| * @param[in] module Name of the main (belongs-to) module. If NULL, all module submodules are searched. |
| * @param[in] revision Optional revision date of \p module. If NULL, all revisions of \p module |
| * are searched. If set, \p module must also be set. |
| * @param[in] submodule Name of the submodule to get. |
| * @param[in] sub_revision Optional revision date of \p submodule. If NULL, the newest revision of \p submodule |
| * is returned. |
| * @return Pointer to the data model structure. |
| */ |
| const struct lys_submodule *ly_ctx_get_submodule(const struct ly_ctx *ctx, const char *module, const char *revision, |
| const char *submodule, const char *sub_revision); |
| |
| /** |
| * @brief Get submodule of a main module. |
| * |
| * If you have only the name (and optionally revision) of the submodule's main module, use ly_ctx_get_submodule() |
| * instead. |
| * |
| * @param[in] main_module Main module (belongs to) of the searched submodule. |
| * @param[in] submodule Name of the submodule to get. |
| * @return Pointer to the data model structure. |
| */ |
| const struct lys_submodule *ly_ctx_get_submodule2(const struct lys_module *main_module, const char *submodule); |
| |
| /** |
| * @brief Get schema node according to the given data path (JSON format, see @ref howtoxpath). |
| * |
| * This function is meant as a utility function to ease getting a specific schema node |
| * directly from context having \p data_path a const immutable string. Generally, |
| * it is better to use lyd_find_path(), lys_find_path(), or ly_ctx_find_path(). Also, |
| * it is possible to transform data paths into schema paths using ly_path_data2schema(). |
| * |
| * @param[in] ctx Context to work in. Must be set if \p start is NULL. |
| * @param[in] start Starting node for a relative data node identifier, in which |
| * case it is mandatory and \p ctx can be NULL. |
| * @param[in] data_path JSON data path of the node to get. |
| * @param[in] output Search operation output instead input. |
| * @return Resolved schema node or NULL. |
| */ |
| const struct lys_node *ly_ctx_get_node(struct ly_ctx *ctx, const struct lys_node *start, const char *data_path, int output); |
| |
| /** |
| * @brief Get schema node according to the given schema path (see @ref howtoxpath). |
| * |
| * Note that the given path must be absolute and fully prefixed (which is the default output |
| * of lys_path() function). To get node specified by a relative path, use lys_find_path() instead. |
| * |
| * @param[in] ctx Context to work in. |
| * @param[in] path Schema path of the node to find. |
| * @return Set of found schema nodes. If no nodes are matching \p path the returned set is empty. |
| * In case of an error, NULL is returned. |
| */ |
| struct ly_set *ly_ctx_find_path(struct ly_ctx *ctx, const char *path); |
| |
| /** |
| * @brief Remove the specified module from its context. |
| * |
| * Beside the selected module, also all other modules depending on all the modules being removed |
| * will be removed as well. |
| * |
| * libyang internal modules (those present when the context is created) cannot be removed. |
| * |
| * @param[in] module Module to be removed. |
| * @param[in] private_destructor Optional destructor function for private objects assigned |
| * to the nodes via lys_set_private(). If NULL, the private objects are not freed by libyang. |
| * @return EXIT_SUCCESS or EXIT_FAILURE (in case of invalid parameter). |
| */ |
| int ly_ctx_remove_module(const struct lys_module *module, |
| void (*private_destructor)(const struct lys_node *node, void *priv)); |
| |
| /** |
| * @brief Remove all the modules from the context except the internal modules. Also the addition data in |
| * dictionary are kept. |
| * |
| * @param[in] ctx Context to work in. |
| * @param[in] private_destructor Optional destructor function for private objects assigned |
| * to the nodes via lys_set_private(). If NULL, the private objects are not freed by libyang. |
| */ |
| void ly_ctx_clean(struct ly_ctx *ctx, void (*private_destructor)(const struct lys_node *node, void *priv)); |
| |
| /** |
| * @brief Free all internal structures of the specified context. |
| * |
| * The function should be used before terminating the application to destroy |
| * and free all structures internally used by libyang. If the caller uses |
| * multiple contexts, the function should be called for each used context. |
| * |
| * All instance data are supposed to be freed before destroying the context. |
| * Data models are destroyed automatically as part of ly_ctx_destroy() call. |
| * |
| * @param[in] ctx libyang context to destroy |
| * @param[in] private_destructor Optional destructor function for private objects assigned |
| * to the nodes via lys_set_private(). If NULL, the private objects are not freed by libyang. |
| * Remember the differences between the structures derived from ::lys_node and always check |
| * ::lys_node#nodetype. |
| */ |
| void ly_ctx_destroy(struct ly_ctx *ctx, void (*private_destructor)(const struct lys_node *node, void *priv)); |
| |
| /** |
| * @brief Transform a data path in XML format (node prefixes are XML namespace prefixes of module namespaces) |
| * to JSON format (node prefixes are module names directly). |
| * |
| * @param[in] ctx Context to work in. |
| * @param[in] xml_path Path in XML format to transform. |
| * @param[in] xml XML tree to be used for XML namespace prefix resolution. |
| * @return Transformed JSON data path, needs to be freed. NULL on error. |
| */ |
| char *ly_path_xml2json(struct ly_ctx *ctx, const char *xml_path, struct lyxml_elem *xml); |
| |
| /** |
| * @brief Transform a data path into schema path (see @ref howtoxpath). |
| * |
| * Some XPath tokens such as "*" or "//" should not be used because they cannot be properly |
| * transformed into schema path. If used, any following nodes will not be transformed and simply copied, |
| * so use at your own risk! It causes no problems if the path ends with the aforementioned tokens. |
| * |
| * @param[in] ctx Context to work in. |
| * @param[in] data_path Data path to be transformed. |
| * @return Created schema path, NULL on error. |
| */ |
| char *ly_path_data2schema(struct ly_ctx *ctx, const char *data_path); |
| |
| /** @} context */ |
| |
| /** |
| * @defgroup nodeset Tree nodes set |
| * @ingroup datatree |
| * @ingroup schematree |
| * @{ |
| * |
| * Structure and functions to hold and manipulate with sets of nodes from schema or data trees. |
| */ |
| |
| /** |
| * @brief set array of ::ly_set |
| * It is kept in union to keep ::ly_set generic for data as well as schema trees |
| */ |
| union ly_set_set { |
| struct lys_node **s; /**< array of pointers to a ::lys_node objects */ |
| struct lyd_node **d; /**< array of pointers to a ::lyd_node objects */ |
| void **g; /**< dummy array for generic work */ |
| }; |
| |
| /** |
| * @brief Structure to hold a set of (not necessary somehow connected) ::lyd_node or ::lys_node objects. |
| * Caller is supposed to not mix the type of objects added to the set and according to its knowledge about |
| * the set content, it is supposed to access the set via the sset, dset or set members of the structure. |
| * |
| * Until ly_set_rm() or ly_set_rm_index() is used, the set keeps the order of the inserted items as they |
| * were added into the set, so the first added item is on array index 0. |
| * |
| * To free the structure, use ly_set_free() function, to manipulate with the structure, use other |
| * ly_set_* functions. |
| */ |
| struct ly_set { |
| unsigned int size; /**< allocated size of the set array */ |
| unsigned int number; /**< number of elements in (used size of) the set array */ |
| union ly_set_set set; /**< set array - union to keep ::ly_set generic for data as well as schema trees */ |
| }; |
| |
| /** |
| * @brief Option for ly_set_add() to allow duplicities in the ly_set structure so the |
| * set is not used as a set, but as a list of (container for) items. |
| */ |
| #define LY_SET_OPT_USEASLIST 0x01 |
| |
| /** |
| * @brief Create and initiate new ::ly_set structure. |
| * |
| * @return Created ::ly_set structure or NULL in case of error. |
| */ |
| struct ly_set *ly_set_new(void); |
| |
| /** |
| * @brief Duplicate the existing set. |
| * |
| * @param[in] set Original set to duplicate |
| * @return Duplication of the original set. |
| */ |
| struct ly_set *ly_set_dup(const struct ly_set *set); |
| |
| /** |
| * @brief Add a ::lyd_node or ::lys_node object into the set |
| * |
| * Since it is a set, the function checks for duplicity and if the |
| * node is already in the set, the index of the previously added |
| * node is returned. |
| * |
| * @param[in] set Set where the \p node will be added. |
| * @param[in] node The ::lyd_node or ::lys_node object to be added into the \p set; |
| * @param[in] options Options to change behavior of the function. Accepted options are: |
| * - #LY_SET_OPT_USEASLIST - do not check for duplicities |
| * @return -1 on failure, index of the \p node in the set on success |
| */ |
| int ly_set_add(struct ly_set *set, void *node, int options); |
| |
| /** |
| * @brief Add all objects from \p src to \p trg. |
| * |
| * Since it is a set, the function checks for duplicities. |
| * After success, \p src is completely freed. |
| * |
| * @param[in] trg Target (result) set. |
| * @param[in] src Source set. |
| * @param[in] options Options to change behavior of the function. Accepted options are: |
| * - #LY_SET_OPT_USEASLIST - do not check for duplicities |
| * @return -1 on failure, number of objects added into \p trg on success. |
| */ |
| int ly_set_merge(struct ly_set *trg, struct ly_set *src, int options); |
| |
| /** |
| * @brief Get know if the set contains the specified object. |
| * @param[in] set Set to explore. |
| * @param[in] node Object to be found in the set. |
| * @return Index of the object in the set or -1 if the object is not present in the set. |
| */ |
| int ly_set_contains(const struct ly_set *set, void *node); |
| |
| /** |
| * @brief Remove all objects from the set, but keep the set container for further use. |
| * |
| * @param[in] set Set to clean. |
| * @return 0 on success |
| */ |
| int ly_set_clean(struct ly_set *set); |
| |
| /** |
| * @brief Remove a ::lyd_node or ::lys_node object from the set. |
| * |
| * Note that after removing a node from a set, indexes of other nodes in the set can change |
| * (the last object is placed instead of the removed object). |
| * |
| * @param[in] set Set from which the \p node will be removed. |
| * @param[in] node The ::lyd_node or ::lys_node object to be removed from the \p set; |
| * @return 0 on success |
| */ |
| int ly_set_rm(struct ly_set *set, void *node); |
| |
| /** |
| * @brief Remove a ::lyd_node or ::lys_node object from the set index. |
| * |
| * Note that after removing a node from a set, indexes of other nodes in the set can change |
| * (the last object is placed instead of the removed object). |
| * |
| * @param[in] set Set from which a node will be removed. |
| * @param[in] index Index of the ::lyd_node or ::lys_node object in the \p set to be removed from the \p set; |
| * @return 0 on success |
| */ |
| int ly_set_rm_index(struct ly_set *set, unsigned int index); |
| |
| /** |
| * @brief Free the ::ly_set data. Frees only the set structure content, not the referred data. |
| * |
| * @param[in] set The set to be freed. |
| */ |
| void ly_set_free(struct ly_set *set); |
| |
| /**@} nodeset */ |
| |
| /** |
| * @defgroup printerflags Printer flags |
| * @ingroup datatree |
| * |
| * Validity flags for data nodes. |
| * |
| * @{ |
| */ |
| #define LYP_WITHSIBLINGS 0x01 /**< Flag for printing also the (following) sibling nodes of the data node. */ |
| #define LYP_FORMAT 0x02 /**< Flag for formatted output. */ |
| #define LYP_KEEPEMPTYCONT 0x04 /**< Preserve empty non-presence containers */ |
| #define LYP_WD_MASK 0xF0 /**< Mask for with-defaults modes */ |
| #define LYP_WD_EXPLICIT 0x00 /**< Explicit mode - print only data explicitly being present in the data tree. |
| Note that this is the default value when no WD option is specified. */ |
| #define LYP_WD_TRIM 0x10 /**< Do not print the nodes with the value equal to their default value */ |
| #define LYP_WD_ALL 0x20 /**< Include implicit default nodes */ |
| #define LYP_WD_ALL_TAG 0x40 /**< Same as #LYP_WD_ALL but also adds attribute 'default' with value 'true' to |
| all nodes that has its default value. The 'default' attribute has namespace: |
| urn:ietf:params:xml:ns:netconf:default:1.0 and thus the attributes are |
| printed only when the ietf-netconf-with-defaults module is present in libyang |
| context (but in that case this namespace is always printed). */ |
| #define LYP_WD_IMPL_TAG 0x80 /**< Same as LYP_WD_ALL_TAG but the attributes are added only to the nodes that |
| are not explicitly present in the original data tree despite their |
| value is equal to their default value. There is the same limitation regarding |
| the presence of ietf-netconf-with-defaults module in libyang context. */ |
| #define LYP_NETCONF 0x100 /**< Print the data tree for use in NETCONF meaning: |
| - for RPC output - skip the top-level RPC node, |
| - for action output - skip all the parents of and the action node itself, |
| - for action input - enclose the data in an action element in the base YANG namespace, |
| - for all other data - print the whole data tree normally. */ |
| |
| /** |
| * @} |
| */ |
| |
| /** |
| * @defgroup logger Logger |
| * @{ |
| * |
| * Publicly visible functions and values of the libyang logger. For more |
| * information, see \ref howtologger. |
| */ |
| |
| /** |
| * @typedef LY_LOG_LEVEL |
| * @brief Verbosity levels of the libyang logger. |
| */ |
| typedef enum { |
| LY_LLERR = 0, /**< Print only error messages, default value. */ |
| LY_LLWRN = 1, /**< Print error and warning messages. */ |
| LY_LLVRB = 2, /**< Besides errors and warnings, print some other verbose messages. */ |
| LY_LLDBG = 3 /**< Print all messages including some development debug messages (be careful, |
| without subsequently calling ly_verb_dbg() no debug messages will be printed!). */ |
| } LY_LOG_LEVEL; |
| |
| /** |
| * @brief Set logger verbosity level. |
| * @param[in] level Verbosity level. |
| * @return Previous verbosity level. |
| */ |
| LY_LOG_LEVEL ly_verb(LY_LOG_LEVEL level); |
| |
| /** |
| * @defgroup logopts Logging options |
| * @ingroup logger |
| * |
| * Logging option bits of libyang. |
| * |
| * @{ |
| */ |
| #define LY_LOLOG 0x01 /**< Log messages normally, using callback if set. If not set, messages will |
| not be printed by libyang. */ |
| #define LY_LOSTORE 0x02 /**< Store any generated errors or warnings, never verbose or debug messages. |
| Note that if #LY_LOLOG is not set then verbose and debug messages are always lost. */ |
| #define LY_LOSTORE_LAST 0x06 /**< Store any generated errors or warnings but only the last message, always overwrite |
| the previous one. */ |
| |
| /** |
| * @} |
| */ |
| |
| /** |
| * @brief Set additional logger options. Default is #LY_LOLOG | #LY_LOSTORE_LAST. |
| * |
| * @param[in] opts Bitfield of @ref logopts. |
| * @return Previous logger options. |
| */ |
| int ly_log_options(int opts); |
| |
| #ifndef NDEBUG |
| |
| /** |
| * @defgroup dbggroup Debug message groups |
| * @ingroup logger |
| * |
| * Selected displayed debug message groups. |
| * |
| * @{ |
| */ |
| |
| #define LY_LDGDICT 0x01 /**< Dictionary additions and deletions. */ |
| #define LY_LDGYANG 0x02 /**< YANG parser messages. */ |
| #define LY_LDGYIN 0x04 /**< YIN parser messages. */ |
| #define LY_LDGXPATH 0x08 /**< XPath parsing end evaluation. */ |
| #define LY_LDGDIFF 0x10 /**< Diff processing and creation. */ |
| |
| /** |
| * @} |
| */ |
| |
| /** |
| * @brief Enable specific debugging messages (independent of log level). |
| * @param[in] dbg_groups Bitfield of enabled debug message groups (see @ref dbggroup). |
| */ |
| void ly_verb_dbg(int dbg_groups); |
| |
| #endif |
| |
| /** |
| * @brief Set logger callback. |
| * |
| * !IMPORTANT! If an error has a specific error-app-tag defined in the model, it will NOT be set |
| * at the time of calling this callback. It will be set right after, so to retrieve it |
| * it must be checked afterwards with ly_errapptag(). |
| * |
| * @param[in] clb Logging callback. |
| * @param[in] path flag to resolve and provide path as the third parameter of the callback function. In case of |
| * validation and some other errors, it can be useful to get the path to the problematic element. Note, |
| * that according to the tree type and the specific situation, the path can slightly differs (keys |
| * presence) or it can be NULL, so consider it as an optional parameter. If the flag is 0, libyang will |
| * not bother with resolving the path. |
| */ |
| void ly_set_log_clb(void (*clb)(LY_LOG_LEVEL level, const char *msg, const char *path), int path); |
| |
| /** |
| * @brief Get logger callback. |
| * @return Logger callback (can be NULL). |
| */ |
| void (*ly_get_log_clb(void))(LY_LOG_LEVEL, const char *, const char *); |
| |
| /** |
| * @typedef LY_ERR |
| * @brief libyang's error codes available via ly_errno extern variable. |
| * @ingroup logger |
| */ |
| typedef enum { |
| LY_SUCCESS = 0, /**< no error, not set by functions, included just to complete #LY_ERR enumeration */ |
| LY_EMEM, /**< Memory allocation failure */ |
| LY_ESYS, /**< System call failure */ |
| LY_EINVAL, /**< Invalid value */ |
| LY_EINT, /**< Internal error */ |
| LY_EVALID, /**< Validation failure */ |
| LY_EPLUGIN /**< Error reported by a plugin */ |
| } LY_ERR; |
| |
| /** |
| * @typedef LY_VECODE |
| * @brief libyang's codes of validation error. Whenever ly_errno is set to LY_EVALID, the ly_vecode is also set |
| * to the appropriate LY_VECODE value. |
| * @ingroup logger |
| */ |
| typedef enum { |
| LYVE_SUCCESS = 0, /**< no error */ |
| |
| LYVE_XML_MISS, /**< missing XML object */ |
| LYVE_XML_INVAL, /**< invalid XML object */ |
| LYVE_XML_INCHAR, /**< invalid XML character */ |
| |
| LYVE_EOF, /**< unexpected end of input data */ |
| LYVE_INSTMT, /**< invalid statement (schema) */ |
| /* */ |
| LYVE_INPAR, /**< invalid (in)direct parent (schema) */ |
| LYVE_INID, /**< invalid identifier (schema) */ |
| LYVE_INDATE, /**< invalid date format */ |
| LYVE_INARG, /**< invalid value of a statement argument (schema) */ |
| LYVE_MISSSTMT, /**< missing required statement (schema) */ |
| /* */ |
| LYVE_MISSARG, /**< missing required statement argument (schema) */ |
| LYVE_TOOMANY, /**< too many instances of some object */ |
| LYVE_DUPID, /**< duplicated identifier (schema) */ |
| LYVE_DUPLEAFLIST, /**< multiple instances of leaf-list */ |
| LYVE_DUPLIST, /**< multiple instances of list */ |
| LYVE_NOUNIQ, /**< unique leaves match on 2 list instances (data) */ |
| LYVE_ENUM_INVAL, /**< invalid enum value (schema) */ |
| LYVE_ENUM_INNAME, /**< invalid enum name (schema) */ |
| /* */ |
| /* */ |
| LYVE_ENUM_WS, /**< enum name with leading/trailing whitespaces (schema) */ |
| LYVE_BITS_INVAL, /**< invalid bits value (schema) */ |
| LYVE_BITS_INNAME, /**< invalid bits name (schema) */ |
| /* */ |
| /* */ |
| LYVE_INMOD, /**< invalid module name */ |
| /* */ |
| LYVE_KEY_NLEAF, /**< list key is not a leaf (schema) */ |
| LYVE_KEY_TYPE, /**< invalid list key type (schema) */ |
| LYVE_KEY_CONFIG, /**< key config value differs from the list config value */ |
| LYVE_KEY_MISS, /**< list key not found (schema) */ |
| LYVE_KEY_DUP, /**< duplicated key identifier (schema) */ |
| LYVE_INREGEX, /**< invalid regular expression (schema) */ |
| LYVE_INRESOLV, /**< no resolvents found (schema) */ |
| LYVE_INSTATUS, /**< invalid derivation because of status (schema) */ |
| LYVE_CIRC_LEAFREFS,/**< circular chain of leafrefs detected (schema) */ |
| LYVE_CIRC_FEATURES,/**< circular chain of features detected (schema) */ |
| LYVE_CIRC_IMPORTS, /**< circular chain of imports detected (schema) */ |
| LYVE_CIRC_INCLUDES,/**< circular chain of includes detected (schema) */ |
| LYVE_INVER, /**< non-matching YANG versions of module and its submodules (schema) */ |
| LYVE_SUBMODULE, /**< submodule given instead of a module */ |
| |
| LYVE_OBSDATA, /**< obsolete data instantiation (data) */ |
| /* */ |
| LYVE_NORESOLV, /**< no resolvents found for an expression (data) */ |
| LYVE_INELEM, /**< invalid element (data) */ |
| /* */ |
| LYVE_MISSELEM, /**< missing required element (data) */ |
| LYVE_INVAL, /**< invalid value of an element (data) */ |
| LYVE_INMETA, /**< invalid metadata (attribute) value (data) */ |
| LYVE_INATTR, /**< invalid attribute in an element (data) */ |
| LYVE_MISSATTR, /**< missing attribute in an element (data) */ |
| LYVE_NOCONSTR, /**< value out of range/length/pattern (data) */ |
| LYVE_INCHAR, /**< unexpected characters (data) */ |
| LYVE_INPRED, /**< predicate resolution fail (data) */ |
| LYVE_MCASEDATA, /**< data for more cases of a choice (data) */ |
| LYVE_NOMUST, /**< unsatisfied must condition (data) */ |
| LYVE_NOWHEN, /**< unsatisfied when condition (data) */ |
| LYVE_INORDER, /**< invalid order of elements (data) */ |
| LYVE_INWHEN, /**< irresolvable when condition (data) */ |
| LYVE_NOMIN, /**< min-elements constraint not honored (data) */ |
| LYVE_NOMAX, /**< max-elements constraint not honored (data) */ |
| LYVE_NOREQINS, /**< required instance does not exits (data) */ |
| LYVE_NOLEAFREF, /**< leaf pointed to by leafref does not exist (data) */ |
| LYVE_NOMANDCHOICE, /**< no mandatory choice case branch exists (data) */ |
| |
| LYVE_XPATH_INTOK, /**< unexpected XPath token */ |
| LYVE_XPATH_EOF, /**< unexpected end of an XPath expression */ |
| LYVE_XPATH_INOP, /**< invalid XPath operation operands */ |
| /* */ |
| LYVE_XPATH_INCTX, /**< invalid XPath context type */ |
| LYVE_XPATH_INMOD, /**< invalid module name */ |
| LYVE_XPATH_INFUNC, /**< invalid XPath function name */ |
| LYVE_XPATH_INARGCOUNT, /**< invalid number of arguments for an XPath function */ |
| LYVE_XPATH_INARGTYPE, /**< invalid type of arguments for an XPath function */ |
| LYVE_XPATH_DUMMY, /**< invalid use of the XPath dummy node */ |
| LYVE_XPATH_NOEND, /**< unterminated string */ |
| |
| LYVE_PATH_INCHAR, /**< invalid characters (path) */ |
| LYVE_PATH_INMOD, /**< invalid module name (path) */ |
| LYVE_PATH_MISSMOD, /**< missing module name (path) */ |
| LYVE_PATH_INNODE, /**< invalid node name (path) */ |
| LYVE_PATH_INKEY, /**< invalid key name (path) */ |
| LYVE_PATH_MISSKEY, /**< missing some list keys (path) */ |
| LYVE_PATH_EXISTS, /**< target node already exists (path) */ |
| LYVE_PATH_MISSPAR, /**< some parent of the target node is missing (path) */ |
| } LY_VECODE; |
| |
| /** |
| * @cond INTERNAL |
| * Get address of (thread-specific) `ly_errno' variable. |
| */ |
| LY_ERR *ly_errno_glob_address(void); |
| |
| /** |
| * @endcond INTERNAL |
| * @brief libyang specific (thread-safe) errno (see #LY_ERR for the list of possible values and their meaning). |
| */ |
| #define ly_errno (*ly_errno_glob_address()) |
| |
| /** |
| * @brief Get the last (thread, context-specific) validation error code. |
| * |
| * This value is set only if ly_errno is #LY_EVALID. |
| * |
| * @param[in] ctx Relative context. |
| * @return Validation error code. |
| */ |
| LY_VECODE ly_vecode(const struct ly_ctx *ctx); |
| |
| /** |
| * @brief Get the last (thread, context-specific) error message. If the coresponding module defined |
| * a specific error message, it will be used instead the default one. |
| * |
| * Sometimes, the error message is extended with path of the element where the problem is. |
| * The path is available via ly_errpath(). |
| * |
| * @param[in] ctx Relative context. |
| * @return Text of the last error message, empty string if there is no error. |
| */ |
| const char *ly_errmsg(const struct ly_ctx *ctx); |
| |
| /** |
| * @brief Get the last (thread, context-specific) path of the element where was an error. |
| * |
| * The path always corresponds to the error message available via ly_errmsg(), so |
| * whenever a subsequent error message is printed, the path is erased or rewritten. |
| * The path reflects the type of the processed tree - data path for data tree functions |
| * and schema path in case of schema tree functions. In case of processing YIN schema |
| * or XML data, the path can be just XML path. In such a case, the corresponding |
| * ly_vecode (value 1-3) is set. |
| * |
| * @param[in] ctx Relative context. |
| * @return Path of the error element, empty string if error path does not apply to the last error. |
| */ |
| const char *ly_errpath(const struct ly_ctx *ctx); |
| |
| /** |
| * @brief Get the last (thread, context-specific) error-app-tag if there was a specific one defined |
| * in the module for the last error. |
| * |
| * The app-tag always corresponds to the error message available via ly_errmsg(), so |
| * whenever a subsequent error message is printed, the app-tag is erased or rewritten. |
| * |
| * @param[in] ctx Relative context. |
| * @return Error-app-tag of the last error, empty string if the error-app-tag does not apply to the last error. |
| */ |
| const char *ly_errapptag(const struct ly_ctx *ctx); |
| |
| /** |
| * @brief Libyang full error structure. |
| */ |
| struct ly_err_item { |
| LY_LOG_LEVEL level; |
| LY_ERR no; |
| LY_VECODE vecode; |
| char *msg; |
| char *path; |
| char *apptag; |
| struct ly_err_item *next; |
| struct ly_err_item *prev; /* first item's prev points to the last item */ |
| }; |
| |
| /** |
| * @brief Get the first (thread, context-specific) generated error structure. |
| * |
| * @param[in] ctx Relative context. |
| * @return First error structure (can be NULL), do not modify! |
| */ |
| struct ly_err_item *ly_err_first(const struct ly_ctx *ctx); |
| |
| /** |
| * @brief Print the error structure as if just generated. |
| * |
| * @param[in] eitem Error item structure to print. |
| */ |
| void ly_err_print(struct ly_err_item *eitem); |
| |
| /** |
| * @brief Free error structures from a context. |
| * |
| * If \p eitem is not set, free all the error structures. |
| * |
| * @param[in] ctx Relative context. |
| * @param[in] eitem Oldest error structure to remove, optional. |
| */ |
| void ly_err_clean(struct ly_ctx *ctx, struct ly_err_item *eitem); |
| |
| /** |
| * @} logger |
| */ |
| |
| #ifdef __cplusplus |
| } |
| #endif |
| |
| #endif /* LY_LIBYANG_H_ */ |