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diff --git a/src/parser_schema.h b/src/parser_schema.h new file mode 100644 index 0000000..f8df16d --- /dev/null +++ b/src/parser_schema.h @@ -0,0 +1,179 @@ +/** + * @file parser_schema.h + * @author Radek Krejci <rkrejci@cesnet.cz> + * @brief Schema parsers for libyang + * + * Copyright (c) 2015-2020 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_PARSER_SCHEMA_H_ +#define LY_PARSER_SCHEMA_H_ + +#include "log.h" + +#ifdef __cplusplus +extern "C" { +#endif + +struct ly_in; +struct lys_module; + +/** + * @page howtoSchemaParsers Parsing YANG Modules + * + * YANG module parsers allow to read YANG module from a specific format. libyang supports the following module 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 YANG modules, which + * are implemented internally by libyang: + * - ietf-yang-metadata@2016-08-05 + * - yang@2020-06-17 + * - ietf-inet-types@2013-07-15 + * - ietf-yang-types@2013-07-15 + * - ietf-datastores@2018-02-14 + * - ietf-yang-library@2019-01-04 + * + * The `yang` module 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 modules can be added to the context manually with the functions listed below. Besides them, + * it is also possible to use ::ly_ctx_load_module() which tries to find the required module automatically - using + * ::ly_module_imp_clb or automatic search in working directory and in the context's search directories. For details, see + * [how the context works](@ref howtoContext). + * + * YANG modules are loaded in two steps. First, the input YANG/YIN data are parsed into \b lysp_* structures that reflect + * the structure of the input module and submodule(s). Mostly just syntax checks are done, no reference or type checking is + * performed in this step. If the module is supposed to be implemented, not just imported by another module, the second step + * is to compile it. The compiled tree may significantly differ from the source (parsed) tree structure. All the references + * are resolved, groupings are instantiated, types are resolved (and compiled by joining all the relevant restrictions + * when derived from another types) and many other syntactical checks are done. + * + * There is the main parsing function ::lys_parse() working with the libyang [input handler](@ref howtoInput). However, + * to simplify some of the use-cases, it is also possible to use other functions accepting input data from various sources. + * + * Functions List + * -------------- + * - ::lys_parse() + * - ::lys_parse_mem() + * - ::lys_parse_fd() + * - ::lys_parse_path() + * + * - ::lys_search_localfile() + * - ::ly_ctx_set_module_imp_clb() + * - ::ly_ctx_load_module() + */ + +/** + * @addtogroup schematree + * @{ + */ + +/** + * @brief Schema input formats accepted by libyang [parser functions](@ref howtoSchemaParsers). + */ +typedef enum { + LYS_IN_UNKNOWN = 0, /**< unknown format, used as return value in case of error */ + LYS_IN_YANG = 1, /**< YANG schema input format */ + LYS_IN_YIN = 3 /**< YIN schema input format */ +} LYS_INFORMAT; + +/** + * @brief Load a schema into the specified context. + * + * @param[in] ctx libyang context where to process the data model. + * @param[in] in The input handle to provide the dumped data model in the specified format. + * @param[in] format Format of the schema to parse. Can be 0 to try to detect format from the input handler. + * @param[in] features Array of features to enable ended with NULL. If NULL, no features are enabled. + * @param[out] module Optional parsed module. + * @return LY_ERR value. + */ +LIBYANG_API_DECL LY_ERR lys_parse(struct ly_ctx *ctx, struct ly_in *in, LYS_INFORMAT format, const char **features, + struct lys_module **module); + +/** + * @brief Load a schema into the specified context. + * + * This function is considered for a simple use, if you have a complex use-case, + * consider use of ::lys_parse() with a standalone input handler. + * + * @param[in] ctx libyang context where to process the data model. + * @param[in] data The string containing the dumped data model in the specified format. + * @param[in] format Format of the schema to parse. + * @param[out] module Optional parsed module. + * @return LY_ERR value. + */ +LIBYANG_API_DECL LY_ERR lys_parse_mem(struct ly_ctx *ctx, const char *data, LYS_INFORMAT format, struct lys_module **module); + +/** + * @brief Read a schema from file descriptor into the specified context. + * + * \note Current implementation supports only reading data from standard (disk) file, not from sockets, pipes, etc. + * + * This function is considered for a simple use, if you have a complex use-case, + * consider use of ::lys_parse() with a standalone input handler. + * + * @param[in] ctx libyang context where to process the data model. + * @param[in] fd File descriptor of a regular file (e.g. sockets are not supported) containing the schema + * in the specified format. + * @param[in] format Format of the schema to parse. + * @param[out] module Optional parsed module. + * @return LY_ERR value. + */ +LIBYANG_API_DECL LY_ERR lys_parse_fd(struct ly_ctx *ctx, int fd, LYS_INFORMAT format, struct lys_module **module); + +/** + * @brief Load a schema into the specified context from a file. + * + * This function is considered for a simple use, if you have a complex use-case, + * consider use of ::lys_parse() with a standalone input handler. + * + * @param[in] ctx libyang context where to process the data model. + * @param[in] path Path to the file with the model in the specified format. + * @param[in] format Format of the schema to parse. + * @param[out] module Optional parsed module. + * @return LY_ERR value. + */ +LIBYANG_API_DECL LY_ERR lys_parse_path(struct ly_ctx *ctx, const char *path, LYS_INFORMAT format, struct lys_module **module); + +/** + * @brief Search for the schema file in the specified searchpaths. + * + * @param[in] searchpaths NULL-terminated array of paths to be searched (recursively). Current working + * directory is searched automatically (but non-recursively if not in the provided list). Caller can use + * result of the ::ly_ctx_get_searchdirs(). + * @param[in] cwd Flag to implicitly search also in the current working directory (non-recursively). + * @param[in] name Name of the schema to find. + * @param[in] revision Revision of the schema to find. If NULL, the newest found schema filepath is returned. + * @param[out] localfile Mandatory output variable containing absolute path of the found schema. If no schema + * complying the provided restriction is found, NULL is set. + * @param[out] format Optional output variable containing expected format of the schema document according to the + * file suffix. + * @return LY_ERR value (LY_SUCCESS is returned even if the file is not found, then the *localfile is NULL). + */ +LIBYANG_API_DECL LY_ERR lys_search_localfile(const char * const *searchpaths, ly_bool cwd, const char *name, const char *revision, + char **localfile, LYS_INFORMAT *format); + +/** @} schematree */ + +#ifdef __cplusplus +} +#endif + +#endif /* LY_PARSER_SCHEMA_H_ */ |