Adding upstream version 2.1.30.upstream/2.1.30upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 263 insertions, 0 deletions

diff --git a/src/path.h b/src/path.h
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+++ b/src/path.h
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+/**
+ * @file path.h
+ * @author Michal Vasko <mvasko@cesnet.cz>
+ * @brief Path structure and manipulation routines.
+ *
+ * Copyright (c) 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_PATH_H_
+#define LY_PATH_H_
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "log.h"
+#include "tree.h"
+#include "tree_data.h"
+
+struct ly_ctx;
+struct lys_module;
+struct lysc_ext_instance;
+struct lysc_node;
+struct lyxp_expr;
+
+enum ly_path_pred_type {
+    LY_PATH_PREDTYPE_NONE = 0,  /**< no predicate */
+    LY_PATH_PREDTYPE_POSITION,  /**< position predicate - [2] */
+    LY_PATH_PREDTYPE_LIST,      /**< keys predicate - [key1='val1'][key2='val2']... */
+    LY_PATH_PREDTYPE_LEAFLIST   /**< leaflist value predicate - [.='value'] */
+};
+
+/**
+ * @brief Structure for simple path predicate.
+ */
+struct ly_path_predicate {
+    union {
+        uint64_t position; /**< position value for the position-predicate */
+
+        struct {
+            const struct lysc_node *key; /**< key node of the predicate, NULL in
+                                            case of a leaf-list predicate */
+            struct lyd_value value; /**< value representation according to the
+                                       key's type, its realtype is allocated */
+        };
+    };
+};
+
+/**
+ * @brief Structure for holding one segment of resolved path on schema including
+ * simple predicates. Is used as a [sized array](@ref sizedarrays).
+ */
+struct ly_path {
+    const struct lysc_node *node; /**< Schema node representing the path segment, first node has special meaning:
+                                       - is a top-level node - path is absolute,
+                                       - is inner node - path is relative */
+    const struct lysc_ext_instance *ext;    /**< Extension instance of @p node, if any */
+    struct ly_path_predicate *predicates;   /**< [Sized array](@ref sizedarrays) of the path segment's predicates */
+    enum ly_path_pred_type pred_type;       /**< Predicate type (see YANG ABNF) */
+};
+
+/**
+ * @defgroup path_begin_options Path begin options.
+ * @{
+ */
+#define LY_PATH_BEGIN_ABSOLUTE  0x01    /**< path must be absolute */
+#define LY_PATH_BEGIN_EITHER    0x02    /**< path be be either absolute or relative */
+/** @} */
+
+/**
+ * @defgroup path_prefix_options Path prefix options.
+ * @{
+ */
+#define LY_PATH_PREFIX_OPTIONAL     0x10    /**< prefixes in the path are optional */
+#define LY_PATH_PREFIX_MANDATORY    0x20    /**< prefixes in the path are mandatory (XML instance-identifier) */
+#define LY_PATH_PREFIX_STRICT_INHERIT 0x30  /**< prefixes in the path are mandatory in case they differ from the
+                                                 previous prefixes, otherwise they are prohibited (JSON instance-identifier) */
+/** @} */
+
+/**
+ * @defgroup path_pred_options Path predicate options.
+ * @{
+ */
+#define LY_PATH_PRED_KEYS       0x40 /* expected predicate only - [node='value']* */
+#define LY_PATH_PRED_SIMPLE     0x80 /* expected predicates - [node='value']*; [.='value']; [1] */
+#define LY_PATH_PRED_LEAFREF    0xC0 /* expected predicates only leafref - [node=current()/../../../node/node];
+                                        at least 1 ".." and 1 "node" after */
+/** @} */
+
+/**
+ * @brief Parse path into XPath token structure and perform all additional checks.
+ *
+ * @param[in] ctx libyang context.
+ * @param[in] ctx_node Optional context node, used for logging.
+ * @param[in] str_path Path to parse.
+ * @param[in] path_len Length of @p str_path.
+ * @param[in] lref Whether leafref is being parsed or not.
+ * @param[in] begin Begin option (@ref path_begin_options).
+ * @param[in] prefix Prefix option (@ref path_prefix_options).
+ * @param[in] pred Predicate option (@ref path_pred_options).
+ * @param[out] expr Parsed path.
+ * @return LY_ERR value.
+ */
+LY_ERR ly_path_parse(const struct ly_ctx *ctx, const struct lysc_node *ctx_node, const char *str_path, size_t path_len,
+        ly_bool lref, uint8_t begin, uint8_t prefix, uint8_t pred, struct lyxp_expr **expr);
+
+/**
+ * @brief Parse predicate into XPath token structure and perform all additional checks.
+ *
+ * @param[in] ctx libyang context.
+ * @param[in] cur_node Optional current (original context) node, used for logging.
+ * @param[in] str_path Path to parse.
+ * @param[in] path_len Length of @p str_path.
+ * @param[in] prefix Prefix option (@ref path_prefix_options).
+ * @param[in] pred Predicate option (@ref path_pred_options).
+ * @param[out] expr Parsed path.
+ * @return LY_ERR value.
+ */
+LY_ERR ly_path_parse_predicate(const struct ly_ctx *ctx, const struct lysc_node *cur_node, const char *str_path,
+        size_t path_len, uint8_t prefix, uint8_t pred, struct lyxp_expr **expr);
+
+/**
+ * @defgroup path_oper_options Path operation options.
+ * @{
+ */
+#define LY_PATH_OPER_INPUT  0x01    /**< if any RPC/action is traversed, its input nodes are used */
+#define LY_PATH_OPER_OUTPUT 0x02    /**< if any RPC/action is traversed, its output nodes are used */
+/** @} */
+
+/* lref */
+
+/**
+ * @defgroup path_target_options Path target options.
+ * @{
+ */
+#define LY_PATH_TARGET_SINGLE  0x10    /**< last (target) node must identify an exact instance */
+#define LY_PATH_TARGET_MANY    0x20    /**< last (target) node may identify all instances (of leaf-list/list) */
+/** @} */
+
+/**
+ * @brief Compile path into ly_path structure.
+ *
+ * @param[in] ctx libyang context.
+ * @param[in] cur_mod Current module of the path (where it was "instantiated"). Used for nodes in schema-nodeid
+ * without a prefix for ::LY_VALUE_SCHEMA and ::LY_VALUE_SCHEMA_RESOLVED format.
+ * @param[in] ctx_node Optional context node.
+ * @param[in] top_ext Extension instance containing the definition of the data being created. It is used to find the top-level
+ * node inside the extension instance instead of a module. Note that this is the case not only if the @p ctx_node is NULL,
+ * but also if the relative path starting in @p ctx_node reaches the document root via double dots.
+ * @param[in] expr Parsed path.
+ * @param[in] oper Oper option (@ref path_oper_options).
+ * @param[in] target Target option (@ref path_target_options).
+ * @param[in] limit_access_tree Whether to limit accessible tree.
+ * @param[in] format Format of the path.
+ * @param[in] prefix_data Format-specific data for resolving any prefixes (see ::ly_resolve_prefix).
+ * @param[out] path Compiled path.
+ * @return LY_ERR value.
+ */
+LY_ERR ly_path_compile(const struct ly_ctx *ctx, const struct lys_module *cur_mod, const struct lysc_node *ctx_node,
+        const struct lysc_ext_instance *top_ext, const struct lyxp_expr *expr, uint8_t oper, uint8_t target,
+        ly_bool limit_access_tree, LY_VALUE_FORMAT format, void *prefix_data, struct ly_path **path);
+
+/**
+ * @brief Compile path into ly_path structure. Any predicates of a leafref are only checked, not compiled.
+ *
+ * @param[in] ctx libyang context.
+ * @param[in] ctx_node Context node.
+ * @param[in] top_ext Extension instance containing the definition of the data being created. It is used to find the top-level
+ * node inside the extension instance instead of a module. Note that this is the case not only if the @p ctx_node is NULL,
+ * but also if the relative path starting in @p ctx_node reaches the document root via double dots.
+ * @param[in] expr Parsed path.
+ * @param[in] oper Oper option (@ref path_oper_options).
+ * @param[in] target Target option (@ref path_target_options).
+ * @param[in] format Format of the path.
+ * @param[in] prefix_data Format-specific data for resolving any prefixes (see ::ly_resolve_prefix).
+ * @param[out] path Compiled path.
+ * @return LY_ERR value.
+ */
+LY_ERR ly_path_compile_leafref(const struct ly_ctx *ctx, const struct lysc_node *ctx_node,
+        const struct lysc_ext_instance *top_ext, const struct lyxp_expr *expr, uint8_t oper, uint8_t target,
+        LY_VALUE_FORMAT format, void *prefix_data, struct ly_path **path);
+
+/**
+ * @brief Compile predicate into ly_path_predicate structure. Only simple predicates (not leafref) are supported.
+ *
+ * @param[in] ctx libyang context.
+ * @param[in] cur_node Optional current (original context) node.
+ * @param[in] cur_mod Current module of the path (where it was "instantiated"). Used for nodes without a prefix
+ * for ::LY_VALUE_SCHEMA and ::LY_VALUE_SCHEMA_RESOLVED format.
+ * @param[in] ctx_node Context node, node for which the predicate is defined.
+ * @param[in] expr Parsed path.
+ * @param[in,out] tok_idx Index in @p expr, is adjusted for parsed tokens.
+ * @param[in] format Format of the path.
+ * @param[in] prefix_data Format-specific data for resolving any prefixes (see ::ly_resolve_prefix).
+ * @param[out] predicates Compiled predicates.
+ * @param[out] pred_type Type of the compiled predicate(s).
+ * @return LY_ERR value.
+ */
+LY_ERR ly_path_compile_predicate(const struct ly_ctx *ctx, const struct lysc_node *cur_node, const struct lys_module *cur_mod,
+        const struct lysc_node *ctx_node, const struct lyxp_expr *expr, uint32_t *tok_idx, LY_VALUE_FORMAT format,
+        void *prefix_data, struct ly_path_predicate **predicates, enum ly_path_pred_type *pred_type);
+
+/**
+ * @brief Resolve at least partially the target defined by ly_path structure. Not supported for leafref!
+ *
+ * @param[in] path Path structure specifying the target.
+ * @param[in] start Starting node for relative paths, can be any for absolute paths.
+ * @param[out] path_idx Last found path segment index, can be NULL, set to 0 if not found.
+ * @param[out] match Last found matching node, can be NULL, set to NULL if not found.
+ * @return LY_ENOTFOUND if no nodes were found,
+ * @return LY_EINCOMPLETE if some node was found but not the last one,
+ * @return LY_SUCCESS when the last node in the path was found,
+ * @return LY_ERR on another error.
+ */
+LY_ERR ly_path_eval_partial(const struct ly_path *path, const struct lyd_node *start, LY_ARRAY_COUNT_TYPE *path_idx,
+        struct lyd_node **match);
+
+/**
+ * @brief Resolve the target defined by ly_path structure. Not supported for leafref!
+ *
+ * @param[in] path Path structure specifying the target.
+ * @param[in] start Starting node for relative paths, can be any for absolute paths.
+ * @param[out] match Found matching node, can be NULL, set to NULL if not found.
+ * @return LY_ENOTFOUND if no nodes were found,
+ * @return LY_SUCCESS when the last node in the path was found,
+ * @return LY_ERR on another error.
+ */
+LY_ERR ly_path_eval(const struct ly_path *path, const struct lyd_node *start, struct lyd_node **match);
+
+/**
+ * @brief Duplicate ly_path structure.
+ *
+ * @param[in] ctx libyang context.
+ * @param[in] path Path to duplicate.
+ * @param[out] dup Duplicated path.
+ * @return LY_ERR value.
+ */
+LY_ERR ly_path_dup(const struct ly_ctx *ctx, const struct ly_path *path, struct ly_path **dup);
+
+/**
+ * @brief Free ly_path_predicate structure.
+ *
+ * @param[in] ctx libyang context.
+ * @param[in] pred_type Predicate type.
+ * @param[in] predicates Predicates ([sized array](@ref sizedarrays)) to free.
+ */
+void ly_path_predicates_free(const struct ly_ctx *ctx, enum ly_path_pred_type pred_type,
+        struct ly_path_predicate *predicates);
+
+/**
+ * @brief Free ly_path structure.
+ *
+ * @param[in] ctx libyang context.
+ * @param[in] path The structure ([sized array](@ref sizedarrays)) to free.
+ */
+void ly_path_free(const struct ly_ctx *ctx, struct ly_path *path);
+
+#endif /* LY_PATH_H_ */