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Michal Vasko004d3152020-06-11 19:59:22 +02001/**
2 * @file path.h
3 * @author Michal Vasko <mvasko@cesnet.cz>
4 * @brief Path structure and manipulation routines.
5 *
6 * Copyright (c) 2020 CESNET, z.s.p.o.
7 *
8 * This source code is licensed under BSD 3-Clause License (the "License").
9 * You may not use this file except in compliance with the License.
10 * You may obtain a copy of the License at
11 *
12 * https://opensource.org/licenses/BSD-3-Clause
13 */
14
15#ifndef LY_PATH_H_
16#define LY_PATH_H_
17
Radek Krejciad97c5f2020-06-30 09:19:28 +020018#include <stddef.h>
Michal Vasko004d3152020-06-11 19:59:22 +020019#include <stdint.h>
20
21#include "log.h"
Michal Vaskof937cfe2020-08-03 16:07:12 +020022#include "plugins_types.h"
Michal Vasko00cbf532020-06-15 13:58:47 +020023#include "tree.h"
Michal Vasko004d3152020-06-11 19:59:22 +020024#include "tree_data.h"
25
Radek Krejciad97c5f2020-06-30 09:19:28 +020026struct ly_ctx;
27struct lys_module;
Michal Vasko004d3152020-06-11 19:59:22 +020028struct lysc_node;
29struct lyxp_expr;
30
31enum ly_path_pred_type {
32 LY_PATH_PREDTYPE_NONE = 0, /**< no predicate */
33 LY_PATH_PREDTYPE_POSITION, /**< position predicate - [2] */
34 LY_PATH_PREDTYPE_LIST, /**< keys predicate - [key1='val1'][key2='val2']... */
35 LY_PATH_PREDTYPE_LEAFLIST /**< leaflist value predicate - [.='value'] */
36};
37
38/**
39 * @brief Structure for holding one segment of resolved path on schema including simple predicates.
40 * Is used as a [sized array](@ref sizedarrays).
41 */
42struct ly_path {
43 const struct lysc_node *node; /**< Schema node representing the path segment, first node has special meaning:
44 - is a top-level node - path is absolute,
45 - is inner node - path is relative */
46 struct ly_path_predicate {
47 union {
48 uint64_t position; /**< position value for the position-predicate */
49 struct {
50 const struct lysc_node *key; /**< key node of the predicate, NULL in case of a leaf-list predicate */
51 struct lyd_value value; /**< value representation according to the key's type */
52 };
53 };
54 } *predicates; /**< [Sized array](@ref sizedarrays) of the path segment's predicates */
55 enum ly_path_pred_type pred_type; /**< Predicate type (see YANG ABNF) */
56};
57
58/**
59 * @defgroup path_begin_options Path begin options.
60 * @{
61 */
62#define LY_PATH_BEGIN_ABSOLUTE 0x01 /**< path must be absolute */
63#define LY_PATH_BEGIN_EITHER 0x02 /**< path be be iether absolute or relative */
64/** @} */
65
66/**
67 * @defgroup path_lref_options Path leafref options.
68 * @{
69 */
70#define LY_PATH_LREF_FALSE 0x04 /**< path does not represent leafref */
71#define LY_PATH_LREF_TRUE 0x08 /* '..' in path allowed, special leafref predicates expected (but are not compiled),
72 implement traversed modules */
73/** @} */
74
75/**
76 * @defgroup path_prefix_options Path prefix options.
77 * @{
78 */
79#define LY_PATH_PREFIX_OPTIONAL 0x10 /**< prefixes in the path are optional */
Michal Vasko8b06a5e2020-08-06 12:13:08 +020080#define LY_PATH_PREFIX_MANDATORY 0x20 /**< prefixes in the path are mandatory (XML instance-identifier) */
81#define LY_PATH_PREFIX_STRICT_INHERIT 0x30 /**< prefixes in the path are mandatory in case they differ from the
82 previous prefixes, otherwise they are prohibited (JSON instance-identifier) */
Michal Vasko004d3152020-06-11 19:59:22 +020083/** @} */
84
85/**
86 * @defgroup path_pred_options Path predicate options.
87 * @{
88 */
89#define LY_PATH_PRED_KEYS 0x40 /* expected predicate only - [node='value']* */
90#define LY_PATH_PRED_SIMPLE 0x80 /* expected predicates - [node='value']*; [.='value']; [1] */
91#define LY_PATH_PRED_LEAFREF 0xC0 /* expected predicates only leafref - [node=current()/../../../node/node];
92 at least 1 ".." and 1 "node" after */
93/** @} */
94
95/**
96 * @brief Parse path into XPath token structure and perform all additional checks.
97 *
98 * @param[in] ctx libyang context.
Michal Vasko6b26e742020-07-17 15:02:10 +020099 * @param[in] ctx_node Optional context node.
Michal Vasko004d3152020-06-11 19:59:22 +0200100 * @param[in] str_path Path to parse.
101 * @param[in] path_len Length of @p str_path.
102 * @param[in] begin Begin option (@ref path_begin_options).
103 * @param[in] lref Lref option (@ref path_lref_options).
104 * @param[in] prefix Prefix option (@ref path_prefix_options).
105 * @param[in] pred Predicate option (@ref path_pred_options).
106 * @param[out] expr Parsed path.
107 * @return LY_ERR value.
108 */
Michal Vasko6b26e742020-07-17 15:02:10 +0200109LY_ERR ly_path_parse(const struct ly_ctx *ctx, const struct lysc_node *ctx_node, const char *str_path, size_t path_len,
110 uint8_t begin, uint8_t lref, uint8_t prefix, uint8_t pred, struct lyxp_expr **expr);
Michal Vasko004d3152020-06-11 19:59:22 +0200111
112/**
113 * @brief Parse predicate into XPath token structure and perform all additional checks.
114 *
115 * @param[in] ctx libyang context.
Michal Vasko6b26e742020-07-17 15:02:10 +0200116 * @param[in] cur_node Optional current (original context) node.
Michal Vasko004d3152020-06-11 19:59:22 +0200117 * @param[in] str_path Path to parse.
118 * @param[in] path_len Length of @p str_path.
119 * @param[in] prefix Prefix option (@ref path_prefix_options).
120 * @param[in] pred Predicate option (@ref path_pred_options).
121 * @param[out] expr Parsed path.
122 * @return LY_ERR value.
123 */
Michal Vasko6b26e742020-07-17 15:02:10 +0200124LY_ERR ly_path_parse_predicate(const struct ly_ctx *ctx, const struct lysc_node *cur_node, const char *str_path,
125 size_t path_len, uint8_t prefix, uint8_t pred, struct lyxp_expr **expr);
Michal Vasko004d3152020-06-11 19:59:22 +0200126
127/**
Michal Vasko00cbf532020-06-15 13:58:47 +0200128 * @defgroup path_oper_options Path operation options.
129 * @{
130 */
131#define LY_PATH_OPER_INPUT 0x01 /**< if any RPC/action is traversed, its input nodes are used */
132#define LY_PATH_OPER_OUTPUT 0x02 /**< if any RPC/action is traversed, its output nodes are used */
133/** @} */
134
135/* lref */
136
137/**
138 * @defgroup path_target_options Path target options.
139 * @{
140 */
141#define LY_PATH_TARGET_SINGLE 0x10 /**< last (target) node must identify an exact instance */
142#define LY_PATH_TARGET_MANY 0x20 /**< last (target) node may identify all instances (of leaf-list/list) */
143/** @} */
144
145/**
Michal Vasko004d3152020-06-11 19:59:22 +0200146 * @brief Compile path into ly_path structure. Any predicates of a leafref are only checked, not compiled.
147 *
Michal Vasko00cbf532020-06-15 13:58:47 +0200148 * @param[in] ctx libyang context.
Michal Vasko004d3152020-06-11 19:59:22 +0200149 * @param[in] cur_mod Module of the current (original context) node. Used for nodes without prefix for ::LYD_SCHEMA format.
Michal Vasko6b26e742020-07-17 15:02:10 +0200150 * @param[in] ctx_node Optional context node.
Michal Vasko004d3152020-06-11 19:59:22 +0200151 * @param[in] expr Parsed path.
152 * @param[in] lref Lref option (@ref path_lref_options).
Michal Vasko00cbf532020-06-15 13:58:47 +0200153 * @param[in] oper Oper option (@ref path_oper_options).
154 * @param[in] target Target option (@ref path_target_options).
Michal Vasko004d3152020-06-11 19:59:22 +0200155 * @param[in] resolve_prefix Callback for prefix resolution.
156 * @param[in] prefix_data Data for @p resolve_prefix.
157 * @param[in] format Format of the path.
158 * @param[out] path Compiled path.
159 * @return LY_ERR value.
160 */
Michal Vasko00cbf532020-06-15 13:58:47 +0200161LY_ERR ly_path_compile(const struct ly_ctx *ctx, const struct lys_module *cur_mod, const struct lysc_node *ctx_node,
162 const struct lyxp_expr *expr, uint8_t lref, uint8_t oper, uint8_t target,
163 ly_clb_resolve_prefix resolve_prefix, void *prefix_data, LYD_FORMAT format, struct ly_path **path);
Michal Vasko004d3152020-06-11 19:59:22 +0200164
165/**
166 * @brief Compile predicate into ly_path_predicate structure. Only simple predicates (not leafref) are supported.
167 *
Michal Vasko00cbf532020-06-15 13:58:47 +0200168 * @param[in] ctx libyang context.
Michal Vasko6b26e742020-07-17 15:02:10 +0200169 * @param[in] cur_node Optional current (original context) node.
Michal Vasko004d3152020-06-11 19:59:22 +0200170 * @param[in] cur_mod Module of the current (original context) node. Used for nodes without prefix for ::LYD_SCHEMA format.
171 * @param[in] ctx_node Context node, node for which the predicate is defined.
172 * @param[in] expr Parsed path.
173 * @param[in,out] tok_idx Index in @p expr, is adjusted for parsed tokens.
174 * @param[in] resolve_prefix Callback for prefix resolution.
175 * @param[in] prefix_data Data for @p resolve_prefix.
176 * @param[in] format Format of the path.
177 * @param[out] predicates Compiled predicates.
178 * @param[out] pred_type Type of the compiled predicate(s).
179 * @return LY_ERR value.
180 */
Michal Vasko6b26e742020-07-17 15:02:10 +0200181LY_ERR ly_path_compile_predicate(const struct ly_ctx *ctx, const struct lysc_node *cur_node, const struct lys_module *cur_mod,
Michal Vasko00cbf532020-06-15 13:58:47 +0200182 const struct lysc_node *ctx_node, const struct lyxp_expr *expr, uint16_t *tok_idx,
183 ly_clb_resolve_prefix resolve_prefix, void *prefix_data, LYD_FORMAT format,
184 struct ly_path_predicate **predicates, enum ly_path_pred_type *pred_type);
185
186/**
187 * @brief Resolve at least partially the target defined by ly_path structure. Not supported for leafref!
188 *
189 * @param[in] path Path structure specifying the target.
190 * @param[in] start Starting node for relative paths, can be any for absolute paths.
191 * @param[out] path_idx Last found path segment index, can be NULL, set to 0 if not found.
192 * @param[out] match Last found matching node, can be NULL, set to NULL if not found.
193 * @return LY_ENOTFOUND if no nodes were found,
194 * @return LY_EINCOMPLETE if some node was found but not the last one,
195 * @return LY_SUCCESS when the last node in the path was found,
196 * @return LY_ERR on another error.
197 */
Michal Vaskofd69e1d2020-07-03 11:57:17 +0200198LY_ERR ly_path_eval_partial(const struct ly_path *path, const struct lyd_node *start, LY_ARRAY_COUNT_TYPE *path_idx,
Michal Vasko00cbf532020-06-15 13:58:47 +0200199 struct lyd_node **match);
Michal Vasko004d3152020-06-11 19:59:22 +0200200
201/**
202 * @brief Resolve the target defined by ly_path structure. Not supported for leafref!
203 *
204 * @param[in] path Path structure specifying the target.
205 * @param[in] start Starting node for relative paths, can be any for absolute paths.
206 * @param[out] match Found matching node, can be NULL, set to NULL if not found.
207 * @return LY_ENOTFOUND if no nodes were found,
208 * @return LY_SUCCESS when the last node in the path was found,
209 * @return LY_ERR on another error.
210 */
211LY_ERR ly_path_eval(const struct ly_path *path, const struct lyd_node *start, struct lyd_node **match);
212
213/**
214 * @brief Duplicate ly_path structure.
215 *
216 * @param[in] ctx libyang context.
217 * @param[in] path Path to duplicate.
218 * @param[out] dup Duplicated path.
219 * @return LY_ERR value.
220 */
221LY_ERR ly_path_dup(const struct ly_ctx *ctx, const struct ly_path *path, struct ly_path **dup);
222
223/**
224 * @brief Free ly_path_predicate structure.
225 *
226 * @param[in] ctx libyang context.
227 * @param[in] pred_type Predicate type.
228 * @param[in] llist Leaf-list in case of leaf-list predicate.
229 * @param[in] predicates Predicates ([sized array](@ref sizedarrays)) to free.
230 */
231void ly_path_predicates_free(const struct ly_ctx *ctx, enum ly_path_pred_type pred_type, const struct lysc_node *llist,
232 struct ly_path_predicate *predicates);
233
234/**
235 * @brief Free ly_path structure.
236 *
237 * @param[in] ctx libyang context.
238 * @param[in] path The structure ([sized array](@ref sizedarrays)) to free.
239 */
240void ly_path_free(const struct ly_ctx *ctx, struct ly_path *path);
241
242#endif /* LY_PATH_H_ */