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gerrit.cesnet.cz / github / CESNET / libyang / 3b6c4dcf3353a7f85112e00c03b6f30e2b8f1c2d / . / src / path.c
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/**
* @file path.c
* @author Michal Vasko <mvasko@cesnet.cz>
* @brief Path functions
*
* 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
*/
#include "path.h"
#include <assert.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
#include "common.h"
#include "compat.h"
#include "log.h"
#include "plugins_types.h"
#include "schema_compile.h"
#include "set.h"
#include "tree.h"
#include "tree_data_internal.h"
#include "tree_edit.h"
#include "tree_schema.h"
#include "tree_schema_internal.h"
#include "xpath.h"
#define LOGVAL_P(CTX, CUR_NODE, CODE, ...) ly_vlog(CTX, (CUR_NODE) ? LY_VLOG_LYSC : LY_VLOG_NONE, CUR_NODE, CODE, ##__VA_ARGS__)
/**
* @brief Check predicate syntax.
*
* @param[in] ctx libyang context.
* @param[in] cur_node Current (original context) node.
* @param[in] exp Parsed predicate.
* @param[in,out] tok_idx Index in @p exp, is adjusted.
* @param[in] prefix Prefix option.
* @param[in] pred Predicate option.
* @return LY_ERR value.
*/
static LY_ERR
ly_path_check_predicate(const struct ly_ctx *ctx, const struct lysc_node *cur_node, const struct lyxp_expr *exp,
uint32_t *tok_idx, uint8_t prefix, uint8_t pred)
{
LY_ERR ret = LY_SUCCESS;
struct ly_set *set = NULL;
uint32_t i;
const char *name;
size_t name_len;
LOG_LOCSET(cur_node, NULL, NULL, NULL);
if (!lyxp_next_token(NULL, exp, tok_idx, LYXP_TOKEN_BRACK1)) {
/* '[' */
if (((pred == LY_PATH_PRED_SIMPLE) || (pred == LY_PATH_PRED_KEYS)) &&
!lyxp_check_token(NULL, exp, *tok_idx, LYXP_TOKEN_NAMETEST)) {
ret = ly_set_new(&set);
LY_CHECK_GOTO(ret, cleanup);
do {
/* NameTest is always expected here */
LY_CHECK_GOTO(lyxp_check_token(ctx, exp, *tok_idx, LYXP_TOKEN_NAMETEST), token_error);
/* check prefix based on the options */
name = strnstr(exp->expr + exp->tok_pos[*tok_idx], ":", exp->tok_len[*tok_idx]);
if ((prefix == LY_PATH_PREFIX_MANDATORY) && !name) {
LOGVAL(ctx, LYVE_XPATH, "Prefix missing for \"%.*s\" in path.", exp->tok_len[*tok_idx],
exp->expr + exp->tok_pos[*tok_idx]);
goto token_error;
} else if ((prefix == LY_PATH_PREFIX_STRICT_INHERIT) && name) {
LOGVAL(ctx, LYVE_XPATH, "Redundant prefix for \"%.*s\" in path.", exp->tok_len[*tok_idx],
exp->expr + exp->tok_pos[*tok_idx]);
goto token_error;
}
if (!name) {
name = exp->expr + exp->tok_pos[*tok_idx];
name_len = exp->tok_len[*tok_idx];
} else {
++name;
name_len = exp->tok_len[*tok_idx] - (name - (exp->expr + exp->tok_pos[*tok_idx]));
}
/* check whether it was not already specified */
for (i = 0; i < set->count; ++i) {
/* all the keys must be from the same module so this comparison should be fine */
if (!strncmp(set->objs[i], name, name_len) && !isalpha(((char *)set->objs[i])[name_len])) {
LOGVAL(ctx, LYVE_XPATH, "Duplicate predicate key \"%.*s\" in path.", (int)name_len, name);
goto token_error;
}
}
/* add it into the set */
ret = ly_set_add(set, (void *)name, 1, NULL);
LY_CHECK_GOTO(ret, cleanup);
/* NameTest */
++(*tok_idx);
/* '=' */
LY_CHECK_GOTO(lyxp_next_token(ctx, exp, tok_idx, LYXP_TOKEN_OPER_EQUAL), token_error);
/* Literal or Number */
LY_CHECK_GOTO(lyxp_next_token2(ctx, exp, tok_idx, LYXP_TOKEN_LITERAL, LYXP_TOKEN_NUMBER), token_error);
/* ']' */
LY_CHECK_GOTO(lyxp_next_token(ctx, exp, tok_idx, LYXP_TOKEN_BRACK2), token_error);
/* '[' */
} while (!lyxp_next_token(NULL, exp, tok_idx, LYXP_TOKEN_BRACK1));
} else if ((pred == LY_PATH_PRED_SIMPLE) && !lyxp_next_token(NULL, exp, tok_idx, LYXP_TOKEN_DOT)) {
/* '.' */
/* '=' */
LY_CHECK_GOTO(lyxp_next_token(ctx, exp, tok_idx, LYXP_TOKEN_OPER_EQUAL), token_error);
/* Literal or Number */
LY_CHECK_GOTO(lyxp_next_token2(ctx, exp, tok_idx, LYXP_TOKEN_LITERAL, LYXP_TOKEN_NUMBER), token_error);
/* ']' */
LY_CHECK_GOTO(lyxp_next_token(ctx, exp, tok_idx, LYXP_TOKEN_BRACK2), token_error);
} else if ((pred == LY_PATH_PRED_SIMPLE) && !lyxp_next_token(NULL, exp, tok_idx, LYXP_TOKEN_NUMBER)) {
/* Number */
/* ']' */
LY_CHECK_GOTO(lyxp_next_token(ctx, exp, tok_idx, LYXP_TOKEN_BRACK2), token_error);
} else if ((pred == LY_PATH_PRED_LEAFREF) && !lyxp_check_token(NULL, exp, *tok_idx, LYXP_TOKEN_NAMETEST)) {
assert(prefix == LY_PATH_PREFIX_OPTIONAL);
ret = ly_set_new(&set);
LY_CHECK_GOTO(ret, cleanup);
do {
/* NameTest is always expected here */
LY_CHECK_GOTO(lyxp_check_token(ctx, exp, *tok_idx, LYXP_TOKEN_NAMETEST), token_error);
name = strnstr(exp->expr + exp->tok_pos[*tok_idx], ":", exp->tok_len[*tok_idx]);
if (!name) {
name = exp->expr + exp->tok_pos[*tok_idx];
name_len = exp->tok_len[*tok_idx];
} else {
++name;
name_len = exp->tok_len[*tok_idx] - (name - (exp->expr + exp->tok_pos[*tok_idx]));
}
/* check whether it was not already specified */
for (i = 0; i < set->count; ++i) {
/* all the keys must be from the same module so this comparison should be fine */
if (!strncmp(set->objs[i], name, name_len) && !isalpha(((char *)set->objs[i])[name_len])) {
LOGVAL(ctx, LYVE_XPATH, "Duplicate predicate key \"%.*s\" in path.", (int)name_len, name);
goto token_error;
}
}
/* add it into the set */
ret = ly_set_add(set, (void *)name, 1, NULL);
LY_CHECK_GOTO(ret, cleanup);
/* NameTest */
++(*tok_idx);
/* '=' */
LY_CHECK_GOTO(lyxp_next_token(ctx, exp, tok_idx, LYXP_TOKEN_OPER_EQUAL), token_error);
/* FuncName */
LY_CHECK_GOTO(lyxp_check_token(ctx, exp, *tok_idx, LYXP_TOKEN_FUNCNAME), token_error);
if ((exp->tok_len[*tok_idx] != ly_strlen_const("current")) ||
strncmp(exp->expr + exp->tok_pos[*tok_idx], "current", ly_strlen_const("current"))) {
LOGVAL(ctx, LYVE_XPATH, "Invalid function \"%.*s\" invocation in path.",
exp->tok_len[*tok_idx], exp->expr + exp->tok_pos[*tok_idx]);
goto token_error;
}
++(*tok_idx);
/* '(' */
LY_CHECK_GOTO(lyxp_next_token(ctx, exp, tok_idx, LYXP_TOKEN_PAR1), token_error);
/* ')' */
LY_CHECK_GOTO(lyxp_next_token(ctx, exp, tok_idx, LYXP_TOKEN_PAR2), token_error);
/* '/' */
LY_CHECK_GOTO(lyxp_next_token(ctx, exp, tok_idx, LYXP_TOKEN_OPER_PATH), token_error);
/* '..' */
LY_CHECK_GOTO(lyxp_next_token(ctx, exp, tok_idx, LYXP_TOKEN_DDOT), token_error);
do {
/* '/' */
LY_CHECK_GOTO(lyxp_next_token(ctx, exp, tok_idx, LYXP_TOKEN_OPER_PATH), token_error);
} while (!lyxp_next_token(NULL, exp, tok_idx, LYXP_TOKEN_DDOT));
/* NameTest */
LY_CHECK_GOTO(lyxp_next_token(ctx, exp, tok_idx, LYXP_TOKEN_NAMETEST), token_error);
/* '/' */
while (!lyxp_next_token(NULL, exp, tok_idx, LYXP_TOKEN_OPER_PATH)) {
/* NameTest */
LY_CHECK_GOTO(lyxp_next_token(ctx, exp, tok_idx, LYXP_TOKEN_NAMETEST), token_error);
}
/* ']' */
LY_CHECK_GOTO(lyxp_next_token(ctx, exp, tok_idx, LYXP_TOKEN_BRACK2), token_error);
/* '[' */
} while (!lyxp_next_token(NULL, exp, tok_idx, LYXP_TOKEN_BRACK1));
} else {
LOGVAL(ctx, LY_VCODE_XP_INTOK, lyxp_token2str(exp->tokens[*tok_idx]), exp->expr + exp->tok_pos[*tok_idx]);
goto token_error;
}
}
cleanup:
LOG_LOCBACK(cur_node ? 1 : 0, 0, 0, 0);
ly_set_free(set, NULL);
return ret;
token_error:
LOG_LOCBACK(cur_node ? 1 : 0, 0, 0, 0);
ly_set_free(set, NULL);
return LY_EVALID;
}
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)
{
LY_ERR ret = LY_SUCCESS;
struct lyxp_expr *exp = NULL;
uint32_t tok_idx, cur_len;
const char *cur_node, *prev_prefix = NULL, *ptr;
assert((begin == LY_PATH_BEGIN_ABSOLUTE) || (begin == LY_PATH_BEGIN_EITHER));
assert((prefix == LY_PATH_PREFIX_OPTIONAL) || (prefix == LY_PATH_PREFIX_MANDATORY) ||
(prefix == LY_PATH_PREFIX_STRICT_INHERIT));
assert((pred == LY_PATH_PRED_KEYS) || (pred == LY_PATH_PRED_SIMPLE) || (pred == LY_PATH_PRED_LEAFREF));
LOG_LOCSET(ctx_node, NULL, NULL, NULL);
/* parse as a generic XPath expression */
LY_CHECK_GOTO(ret = lyxp_expr_parse(ctx, str_path, path_len, 1, &exp), error);
tok_idx = 0;
if (begin == LY_PATH_BEGIN_EITHER) {
/* is the path relative? */
if (lyxp_next_token(NULL, exp, &tok_idx, LYXP_TOKEN_OPER_PATH)) {
/* relative path check specific to leafref */
if (lref) {
/* mandatory '..' */
LY_CHECK_ERR_GOTO(lyxp_next_token(ctx, exp, &tok_idx, LYXP_TOKEN_DDOT), ret = LY_EVALID, error);
do {
/* '/' */
LY_CHECK_ERR_GOTO(lyxp_next_token(ctx, exp, &tok_idx, LYXP_TOKEN_OPER_PATH), ret = LY_EVALID, error);
/* optional '..' */
} while (!lyxp_next_token(NULL, exp, &tok_idx, LYXP_TOKEN_DDOT));
}
}
} else {
/* '/' */
LY_CHECK_ERR_GOTO(lyxp_next_token(ctx, exp, &tok_idx, LYXP_TOKEN_OPER_PATH), ret = LY_EVALID, error);
}
do {
/* NameTest */
LY_CHECK_ERR_GOTO(lyxp_check_token(ctx, exp, tok_idx, LYXP_TOKEN_NAMETEST), ret = LY_EVALID, error);
/* check prefix based on the options */
cur_node = exp->expr + exp->tok_pos[tok_idx];
cur_len = exp->tok_len[tok_idx];
if (prefix == LY_PATH_PREFIX_MANDATORY) {
if (!strnstr(cur_node, ":", cur_len)) {
LOGVAL(ctx, LYVE_XPATH, "Prefix missing for \"%.*s\" in path.", cur_len, cur_node);
ret = LY_EVALID;
goto error;
}
} else if (prefix == LY_PATH_PREFIX_STRICT_INHERIT) {
if (!prev_prefix) {
/* the first node must have a prefix */
if (!strnstr(cur_node, ":", cur_len)) {
LOGVAL(ctx, LYVE_XPATH, "Prefix missing for \"%.*s\" in path.", cur_len, cur_node);
ret = LY_EVALID;
goto error;
}
/* remember the first prefix */
prev_prefix = cur_node;
} else {
/* the prefix must be different, if any */
ptr = strnstr(cur_node, ":", cur_len);
if (ptr) {
if (!strncmp(prev_prefix, cur_node, ptr - cur_node) && (prev_prefix[ptr - cur_node] == ':')) {
LOGVAL(ctx, LYVE_XPATH, "Duplicate prefix for \"%.*s\" in path.", cur_len, cur_node);
ret = LY_EVALID;
goto error;
}
/* remember this next prefix */
prev_prefix = cur_node;
}
}
}
++tok_idx;
/* Predicate* */
LY_CHECK_GOTO(ret = ly_path_check_predicate(ctx, ctx_node, exp, &tok_idx, prefix, pred), error);
/* '/' */
} while (!lyxp_next_token(NULL, exp, &tok_idx, LYXP_TOKEN_OPER_PATH));
/* trailing token check */
if (exp->used > tok_idx) {
LOGVAL(ctx, LYVE_XPATH, "Unparsed characters \"%s\" left at the end of path.", exp->expr + exp->tok_pos[tok_idx]);
ret = LY_EVALID;
goto error;
}
*expr = exp;
LOG_LOCBACK(ctx_node ? 1 : 0, 0, 0, 0);
return LY_SUCCESS;
error:
lyxp_expr_free(ctx, exp);
LOG_LOCBACK(ctx_node ? 1 : 0, 0, 0, 0);
return ret;
}
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)
{
LY_ERR ret = LY_SUCCESS;
struct lyxp_expr *exp = NULL;
uint32_t tok_idx;
assert((prefix == LY_PATH_PREFIX_OPTIONAL) || (prefix == LY_PATH_PREFIX_MANDATORY));
assert((pred == LY_PATH_PRED_KEYS) || (pred == LY_PATH_PRED_SIMPLE) || (pred == LY_PATH_PRED_LEAFREF));
LOG_LOCSET(cur_node, NULL, NULL, NULL);
/* parse as a generic XPath expression */
LY_CHECK_GOTO(ret = lyxp_expr_parse(ctx, str_path, path_len, 0, &exp), error);
tok_idx = 0;
LY_CHECK_GOTO(ret = ly_path_check_predicate(ctx, cur_node, exp, &tok_idx, prefix, pred), error);
/* trailing token check */
if (exp->used > tok_idx) {
LOGVAL(ctx, LYVE_XPATH, "Unparsed characters \"%s\" left at the end of predicate.",
exp->expr + exp->tok_pos[tok_idx]);
ret = LY_EVALID;
goto error;
}
*expr = exp;
LOG_LOCBACK(cur_node ? 1 : 0, 0, 0, 0);
return LY_SUCCESS;
error:
lyxp_expr_free(ctx, exp);
LOG_LOCBACK(cur_node ? 1 : 0, 0, 0, 0);
return ret;
}
/**
* @brief Parse NameTest and get the corresponding schema node.
*
* @param[in] ctx libyang context.
* @param[in] cur_node Optional current (original context) node.
* @param[in] cur_mod Current module of the path (where the path is "instantiated"). Needed for ::LY_VALUE_SCHEMA
* and ::LY_VALUE_SCHEMA_RESOLVED.
* @param[in] prev_ctx_node Previous context node.
* @param[in] expr Parsed path.
* @param[in] tok_idx Index in @p expr.
* @param[in] format Format of the path.
* @param[in] prefix_data Format-specific data for resolving any prefixes (see ::ly_resolve_prefix).
* @param[in] top_ext Optional top-level extension to use for searching the schema node.
* @param[in] getnext_opts Options to be used for ::lys_getnext() calls.
* @param[out] snode Resolved schema node.
* @param[out] ext Optional extension instance of @p snode, if any.
* @return LY_ERR value.
*/
static LY_ERR
ly_path_compile_snode(const struct ly_ctx *ctx, const struct lysc_node *cur_node, const struct lys_module *cur_mod,
const struct lysc_node *prev_ctx_node, const struct lyxp_expr *expr, uint32_t tok_idx, LY_VALUE_FORMAT format,
void *prefix_data, const struct lysc_ext_instance *top_ext, uint32_t getnext_opts, const struct lysc_node **snode,
struct lysc_ext_instance **ext)
{
LY_ERR ret;
const struct lys_module *mod = NULL;
struct lysc_ext_instance *e = NULL;
const char *pref, *name;
size_t len, name_len;
assert(expr->tokens[tok_idx] == LYXP_TOKEN_NAMETEST);
*snode = NULL;
if (ext) {
*ext = NULL;
}
/* get prefix */
if ((pref = strnstr(expr->expr + expr->tok_pos[tok_idx], ":", expr->tok_len[tok_idx]))) {
len = pref - (expr->expr + expr->tok_pos[tok_idx]);
pref = expr->expr + expr->tok_pos[tok_idx];
} else {
len = 0;
}
/* set name */
if (pref) {
name = pref + len + 1;
name_len = expr->tok_len[tok_idx] - len - 1;
} else {
name = expr->expr + expr->tok_pos[tok_idx];
name_len = expr->tok_len[tok_idx];
}
/* find node module */
if (pref) {
LOG_LOCSET(cur_node, NULL, NULL, NULL);
mod = ly_resolve_prefix(prev_ctx_node ? prev_ctx_node->module->ctx : ctx, pref, len, format, prefix_data);
if ((!mod || !mod->implemented) && prev_ctx_node) {
/* check for nested ext data */
ret = ly_nested_ext_schema(NULL, prev_ctx_node, pref, len, format, prefix_data, name, name_len, snode, &e);
if (!ret) {
goto success;
} else if (ret != LY_ENOT) {
goto error;
}
}
if (!mod) {
LOGVAL(ctx, LYVE_XPATH, "No module connected with the prefix \"%.*s\" found (prefix format %s).",
(int)len, pref, ly_format2str(format));
ret = LY_EVALID;
goto error;
} else if (!mod->implemented) {
LOGVAL(ctx, LYVE_XPATH, "Not implemented module \"%s\" in path.", mod->name);
ret = LY_EVALID;
goto error;
}
LOG_LOCBACK(cur_node ? 1 : 0, 0, 0, 0);
} else {
switch (format) {
case LY_VALUE_SCHEMA:
case LY_VALUE_SCHEMA_RESOLVED:
if (!cur_mod) {
LOGINT_RET(ctx);
}
/* use current module */
mod = cur_mod;
break;
case LY_VALUE_JSON:
case LY_VALUE_LYB:
if (!prev_ctx_node) {
LOGINT_RET(ctx);
}
/* inherit module of the previous node */
mod = prev_ctx_node->module;
break;
case LY_VALUE_CANON:
case LY_VALUE_XML:
case LY_VALUE_STR_NS:
/* not really defined or accepted */
LOGINT_RET(ctx);
}
}
/* find schema node */
if (!prev_ctx_node && top_ext) {
*snode = lysc_ext_find_node(top_ext, mod, name, name_len, 0, getnext_opts);
} else {
*snode = lys_find_child(prev_ctx_node, mod, name, name_len, 0, getnext_opts);
if (!(*snode) && prev_ctx_node) {
ret = ly_nested_ext_schema(NULL, prev_ctx_node, pref, len, format, prefix_data, name, name_len, snode, &e);
LY_CHECK_RET(ret && (ret != LY_ENOT), ret);
}
}
if (!(*snode)) {
LOGVAL(ctx, LYVE_XPATH, "Not found node \"%.*s\" in path.", (int)name_len, name);
return LY_ENOTFOUND;
}
success:
if (ext) {
*ext = e;
}
return LY_SUCCESS;
error:
LOG_LOCBACK(cur_node ? 1 : 0, 0, 0, 0);
return ret;
}
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)
{
LY_ERR ret = LY_SUCCESS;
struct ly_path_predicate *p;
const struct lysc_node *key;
const char *val;
size_t val_len, key_count;
assert(ctx && ctx_node);
LOG_LOCSET(cur_node, NULL, NULL, NULL);
*pred_type = 0;
if (lyxp_next_token(NULL, expr, tok_idx, LYXP_TOKEN_BRACK1)) {
/* '[', no predicate */
goto cleanup; /* LY_SUCCESS */
}
if (expr->tokens[*tok_idx] == LYXP_TOKEN_NAMETEST) {
if (ctx_node->nodetype != LYS_LIST) {
LOGVAL(ctx, LYVE_XPATH, "List predicate defined for %s \"%s\" in path.",
lys_nodetype2str(ctx_node->nodetype), ctx_node->name);
ret = LY_EVALID;
goto cleanup;
} else if (ctx_node->flags & LYS_KEYLESS) {
LOGVAL(ctx, LYVE_XPATH, "List predicate defined for keyless %s \"%s\" in path.",
lys_nodetype2str(ctx_node->nodetype), ctx_node->name);
ret = LY_EVALID;
goto cleanup;
}
do {
/* NameTest, find the key */
LY_CHECK_RET(ly_path_compile_snode(ctx, cur_node, cur_mod, ctx_node, expr, *tok_idx, format, prefix_data,
NULL, 0, &key, NULL));
if ((key->nodetype != LYS_LEAF) || !(key->flags & LYS_KEY)) {
LOGVAL(ctx, LYVE_XPATH, "Key expected instead of %s \"%s\" in path.", lys_nodetype2str(key->nodetype),
key->name);
ret = LY_EVALID;
goto cleanup;
}
++(*tok_idx);
if (!*pred_type) {
/* new predicate */
*pred_type = LY_PATH_PREDTYPE_LIST;
}
assert(*pred_type == LY_PATH_PREDTYPE_LIST);
LY_ARRAY_NEW_GOTO(ctx, *predicates, p, ret, cleanup);
p->key = key;
/* '=' */
assert(expr->tokens[*tok_idx] == LYXP_TOKEN_OPER_EQUAL);
++(*tok_idx);
/* Literal or Number */
assert((expr->tokens[*tok_idx] == LYXP_TOKEN_LITERAL) || (expr->tokens[*tok_idx] == LYXP_TOKEN_NUMBER));
if (expr->tokens[*tok_idx] == LYXP_TOKEN_LITERAL) {
/* skip quotes */
val = expr->expr + expr->tok_pos[*tok_idx] + 1;
val_len = expr->tok_len[*tok_idx] - 2;
} else {
val = expr->expr + expr->tok_pos[*tok_idx];
val_len = expr->tok_len[*tok_idx];
}
/* store the value */
LOG_LOCSET(key, NULL, NULL, NULL);
ret = lyd_value_store(ctx, &p->value, ((struct lysc_node_leaf *)key)->type, val, val_len, NULL, format,
prefix_data, LYD_HINT_DATA, key, NULL);
LOG_LOCBACK(key ? 1 : 0, 0, 0, 0);
LY_CHECK_ERR_GOTO(ret, p->value.realtype = NULL, cleanup);
++(*tok_idx);
/* "allocate" the type to avoid problems when freeing the value after the type was freed */
LY_ATOMIC_INC_BARRIER(((struct lysc_type *)p->value.realtype)->refcount);
/* ']' */
assert(expr->tokens[*tok_idx] == LYXP_TOKEN_BRACK2);
++(*tok_idx);
/* another predicate follows? */
} while (!lyxp_next_token(NULL, expr, tok_idx, LYXP_TOKEN_BRACK1));
/* check that all keys were set */
key_count = 0;
for (key = lysc_node_child(ctx_node); key && (key->flags & LYS_KEY); key = key->next) {
++key_count;
}
if (LY_ARRAY_COUNT(*predicates) != key_count) {
/* names (keys) are unique - it was checked when parsing */
LOGVAL(ctx, LYVE_XPATH, "Predicate missing for a key of %s \"%s\" in path.",
lys_nodetype2str(ctx_node->nodetype), ctx_node->name);
ly_path_predicates_free(ctx, LY_PATH_PREDTYPE_LIST, *predicates);
*predicates = NULL;
ret = LY_EVALID;
goto cleanup;
}
} else if (expr->tokens[*tok_idx] == LYXP_TOKEN_DOT) {
if (ctx_node->nodetype != LYS_LEAFLIST) {
LOGVAL(ctx, LYVE_XPATH, "Leaf-list predicate defined for %s \"%s\" in path.",
lys_nodetype2str(ctx_node->nodetype), ctx_node->name);
ret = LY_EVALID;
goto cleanup;
}
++(*tok_idx);
/* new predicate */
*pred_type = LY_PATH_PREDTYPE_LEAFLIST;
LY_ARRAY_NEW_GOTO(ctx, *predicates, p, ret, cleanup);
/* '=' */
assert(expr->tokens[*tok_idx] == LYXP_TOKEN_OPER_EQUAL);
++(*tok_idx);
/* Literal or Number */
assert((expr->tokens[*tok_idx] == LYXP_TOKEN_LITERAL) || (expr->tokens[*tok_idx] == LYXP_TOKEN_NUMBER));
if (expr->tokens[*tok_idx] == LYXP_TOKEN_LITERAL) {
/* skip quotes */
val = expr->expr + expr->tok_pos[*tok_idx] + 1;
val_len = expr->tok_len[*tok_idx] - 2;
} else {
val = expr->expr + expr->tok_pos[*tok_idx];
val_len = expr->tok_len[*tok_idx];
}
/* store the value */
LOG_LOCSET(ctx_node, NULL, NULL, NULL);
ret = lyd_value_store(ctx, &p->value, ((struct lysc_node_leaflist *)ctx_node)->type, val, val_len, NULL, format,
prefix_data, LYD_HINT_DATA, ctx_node, NULL);
LOG_LOCBACK(ctx_node ? 1 : 0, 0, 0, 0);
LY_CHECK_ERR_GOTO(ret, p->value.realtype = NULL, cleanup);
++(*tok_idx);
/* "allocate" the type to avoid problems when freeing the value after the type was freed */
LY_ATOMIC_INC_BARRIER(((struct lysc_type *)p->value.realtype)->refcount);
/* ']' */
assert(expr->tokens[*tok_idx] == LYXP_TOKEN_BRACK2);
++(*tok_idx);
} else {
assert(expr->tokens[*tok_idx] == LYXP_TOKEN_NUMBER);
if (!(ctx_node->nodetype & (LYS_LEAFLIST | LYS_LIST))) {
ret = LY_EVALID;
LOGVAL(ctx, LYVE_XPATH, "Positional predicate defined for %s \"%s\" in path.",
lys_nodetype2str(ctx_node->nodetype), ctx_node->name);
goto cleanup;
} else if (ctx_node->flags & LYS_CONFIG_W) {
ret = LY_EVALID;
LOGVAL(ctx, LYVE_XPATH, "Positional predicate defined for configuration %s \"%s\" in path.",
lys_nodetype2str(ctx_node->nodetype), ctx_node->name);
goto cleanup;
}
/* new predicate */
*pred_type = LY_PATH_PREDTYPE_POSITION;
LY_ARRAY_NEW_GOTO(ctx, *predicates, p, ret, cleanup);
/* syntax was already checked */
p->position = strtoull(expr->expr + expr->tok_pos[*tok_idx], (char **)&val, LY_BASE_DEC);
++(*tok_idx);
/* ']' */
assert(expr->tokens[*tok_idx] == LYXP_TOKEN_BRACK2);
++(*tok_idx);
}
cleanup:
LOG_LOCBACK(cur_node ? 1 : 0, 0, 0, 0);
return ret;
}
/**
* @brief Compile leafref predicate. Actually, it is only checked.
*
* @param[in] ctx_node Context node, node for which the predicate is defined.
* @param[in] cur_node Current (original context) node.
* @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).
* @return LY_ERR value.
*/
static LY_ERR
ly_path_compile_predicate_leafref(const struct lysc_node *ctx_node, const struct lysc_node *cur_node,
const struct lyxp_expr *expr, uint32_t *tok_idx, LY_VALUE_FORMAT format, void *prefix_data)
{
LY_ERR ret = LY_SUCCESS;
const struct lysc_node *key, *node, *node2;
struct ly_ctx *ctx = cur_node->module->ctx;
LOG_LOCSET(cur_node, NULL, NULL, NULL);
if (lyxp_next_token(NULL, expr, tok_idx, LYXP_TOKEN_BRACK1)) {
/* '[', no predicate */
goto cleanup; /* LY_SUCCESS */
}
if (ctx_node->nodetype != LYS_LIST) {
LOGVAL(ctx, LYVE_XPATH, "List predicate defined for %s \"%s\" in path.",
lys_nodetype2str(ctx_node->nodetype), ctx_node->name);
ret = LY_EVALID;
goto cleanup;
} else if (ctx_node->flags & LYS_KEYLESS) {
LOGVAL(ctx, LYVE_XPATH, "List predicate defined for keyless %s \"%s\" in path.",
lys_nodetype2str(ctx_node->nodetype), ctx_node->name);
ret = LY_EVALID;
goto cleanup;
}
do {
/* NameTest, find the key */
ret = ly_path_compile_snode(ctx, cur_node, cur_node->module, ctx_node, expr, *tok_idx, format, prefix_data,
NULL, 0, &key, NULL);
LY_CHECK_GOTO(ret, cleanup);
if ((key->nodetype != LYS_LEAF) || !(key->flags & LYS_KEY)) {
LOGVAL(ctx, LYVE_XPATH, "Key expected instead of %s \"%s\" in path.",
lys_nodetype2str(key->nodetype), key->name);
ret = LY_EVALID;
goto cleanup;
}
++(*tok_idx);
/* we are not actually compiling, throw the key away */
(void)key;
/* '=' */
assert(expr->tokens[*tok_idx] == LYXP_TOKEN_OPER_EQUAL);
++(*tok_idx);
/* FuncName */
assert(expr->tokens[*tok_idx] == LYXP_TOKEN_FUNCNAME);
++(*tok_idx);
/* evaluating from the "current()" node */
node = cur_node;
/* '(' */
assert(expr->tokens[*tok_idx] == LYXP_TOKEN_PAR1);
++(*tok_idx);
/* ')' */
assert(expr->tokens[*tok_idx] == LYXP_TOKEN_PAR2);
++(*tok_idx);
do {
/* '/' */
assert(expr->tokens[*tok_idx] == LYXP_TOKEN_OPER_PATH);
++(*tok_idx);
/* go to parent */
if (!node) {
LOGVAL(ctx, LYVE_XPATH, "Too many parent references in path.");
ret = LY_EVALID;
goto cleanup;
}
node = lysc_data_parent(node);
/* '..' */
assert(expr->tokens[*tok_idx] == LYXP_TOKEN_DDOT);
++(*tok_idx);
} while (expr->tokens[*tok_idx + 1] == LYXP_TOKEN_DDOT);
do {
/* '/' */
assert(expr->tokens[*tok_idx] == LYXP_TOKEN_OPER_PATH);
++(*tok_idx);
/* NameTest */
assert(expr->tokens[*tok_idx] == LYXP_TOKEN_NAMETEST);
LY_CHECK_RET(ly_path_compile_snode(ctx, cur_node, cur_node->module, node, expr, *tok_idx, format,
prefix_data, NULL, 0, &node2, NULL));
node = node2;
++(*tok_idx);
} while ((*tok_idx + 1 < expr->used) && (expr->tokens[*tok_idx + 1] == LYXP_TOKEN_NAMETEST));
/* check the last target node */
if (node->nodetype != LYS_LEAF) {
LOGVAL(ctx, LYVE_XPATH, "Leaf expected instead of %s \"%s\" in leafref predicate in path.",
lys_nodetype2str(node->nodetype), node->name);
ret = LY_EVALID;
goto cleanup;
}
/* we are not actually compiling, throw the rightside node away */
(void)node;
/* ']' */
assert(expr->tokens[*tok_idx] == LYXP_TOKEN_BRACK2);
++(*tok_idx);
/* another predicate follows? */
} while (!lyxp_next_token(NULL, expr, tok_idx, LYXP_TOKEN_BRACK1));
cleanup:
LOG_LOCBACK(1, 0, 0, 0);
return (ret == LY_ENOTFOUND) ? LY_EVALID : ret;
}
/**
* @brief Compile path into ly_path structure. Any predicates of a leafref are only checked, not compiled.
*
* @param[in] ctx libyang context.
* @param[in] cur_mod Current module of the path (where it was "instantiated"), ignored of @p lref. Used for nodes
* without a prefix for ::LY_VALUE_SCHEMA and ::LY_VALUE_SCHEMA_RESOLVED format.
* @param[in] ctx_node Optional context node, mandatory of @p lref.
* @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] lref Whether leafref is being compiled or not.
* @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 as described in
* [XPath context](https://datatracker.ietf.org/doc/html/rfc7950#section-6.4.1).
* @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_ERECOMPILE, only if @p lref.
* @return LY_ERR value.
*/
static 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, ly_bool lref, uint8_t oper, uint8_t target,
ly_bool limit_access_tree, LY_VALUE_FORMAT format, void *prefix_data, struct ly_path **path)
{
LY_ERR ret = LY_SUCCESS;
uint32_t tok_idx = 0, getnext_opts;
const struct lysc_node *node2, *cur_node, *op;
struct ly_path *p = NULL;
struct lysc_ext_instance *ext = NULL;
assert(ctx);
assert(!lref || ctx_node);
assert((oper == LY_PATH_OPER_INPUT) || (oper == LY_PATH_OPER_OUTPUT));
assert((target == LY_PATH_TARGET_SINGLE) || (target == LY_PATH_TARGET_MANY));
if (!limit_access_tree) {
op = NULL;
} else {
/* find operation, if we are in any */
for (op = ctx_node; op && !(op->nodetype & (LYS_RPC | LYS_ACTION | LYS_NOTIF)); op = op->parent) {}
}
*path = NULL;
/* remember original context node */
cur_node = ctx_node;
LOG_LOCSET(cur_node, NULL, NULL, NULL);
if (oper == LY_PATH_OPER_OUTPUT) {
getnext_opts = LYS_GETNEXT_OUTPUT;
} else {
getnext_opts = 0;
}
if (expr->tokens[tok_idx] == LYXP_TOKEN_OPER_PATH) {
/* absolute path */
ctx_node = NULL;
++tok_idx;
} else {
/* relative path */
if (!ctx_node) {
LOGVAL(ctx, LYVE_XPATH, "No initial schema parent for a relative path.");
ret = LY_EVALID;
goto cleanup;
}
/* go up the parents for leafref */
while (lref && (expr->tokens[tok_idx] == LYXP_TOKEN_DDOT)) {
if (!ctx_node) {
LOGVAL(ctx, LYVE_XPATH, "Too many parent references in path.");
ret = LY_EVALID;
goto cleanup;
}
/* get parent */
ctx_node = lysc_data_parent(ctx_node);
++tok_idx;
assert(expr->tokens[tok_idx] == LYXP_TOKEN_OPER_PATH);
++tok_idx;
}
}
do {
/* check last compiled inner node, whether it is uniquely identified (even key-less list) */
if (p && !lref && (target == LY_PATH_TARGET_SINGLE) && (p->node->nodetype == LYS_LIST) && !p->predicates) {
LOGVAL(ctx, LYVE_XPATH, "Predicate missing for %s \"%s\" in path.",
lys_nodetype2str(p->node->nodetype), p->node->name);
ret = LY_EVALID;
goto cleanup;
}
/* NameTest */
LY_CHECK_ERR_GOTO(lyxp_check_token(ctx, expr, tok_idx, LYXP_TOKEN_NAMETEST), ret = LY_EVALID, cleanup);
/* get schema node */
LY_CHECK_GOTO(ret = ly_path_compile_snode(ctx, cur_node, cur_mod, ctx_node, expr, tok_idx, format, prefix_data,
top_ext, getnext_opts, &node2, &ext), cleanup);
++tok_idx;
if ((op && (node2->nodetype & (LYS_RPC | LYS_ACTION | LYS_NOTIF)) && (node2 != op))) {
LOGVAL(ctx, LYVE_XPATH, "Not found node \"%s\" in path.", node2->name);
ret = LY_EVALID;
goto cleanup;
}
ctx_node = node2;
/* new path segment */
LY_ARRAY_NEW_GOTO(ctx, *path, p, ret, cleanup);
p->node = ctx_node;
p->ext = ext;
/* compile any predicates */
if (lref) {
ret = ly_path_compile_predicate_leafref(ctx_node, cur_node, expr, &tok_idx, format, prefix_data);
} else {
ret = ly_path_compile_predicate(ctx, cur_node, cur_mod, ctx_node, expr, &tok_idx, format, prefix_data,
&p->predicates, &p->pred_type);
}
LY_CHECK_GOTO(ret, cleanup);
} while (!lyxp_next_token(NULL, expr, &tok_idx, LYXP_TOKEN_OPER_PATH));
/* check leftover tokens */
if (tok_idx < expr->used) {
LOGVAL(ctx, LY_VCODE_XP_INTOK, lyxp_token2str(expr->tokens[tok_idx]), &expr->expr[expr->tok_pos[tok_idx]]);
ret = LY_EVALID;
goto cleanup;
}
/* check last compiled node */
if (!lref && (target == LY_PATH_TARGET_SINGLE) && (p->node->nodetype & (LYS_LIST | LYS_LEAFLIST)) && !p->predicates) {
LOGVAL(ctx, LYVE_XPATH, "Predicate missing for %s \"%s\" in path.",
lys_nodetype2str(p->node->nodetype), p->node->name);
ret = LY_EVALID;
goto cleanup;
}
cleanup:
if (ret) {
ly_path_free(ctx, *path);
*path = NULL;
}
LOG_LOCBACK(1, 0, 0, 0);
return (ret == LY_ENOTFOUND) ? LY_EVALID : ret;
}
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)
{
return _ly_path_compile(ctx, cur_mod, ctx_node, top_ext, expr, 0, oper, target, limit_access_tree, format,
prefix_data, path);
}
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)
{
return _ly_path_compile(ctx, ctx_node->module, ctx_node, top_ext, expr, 1, oper, target, 1, format, prefix_data, path);
}
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)
{
LY_ARRAY_COUNT_TYPE u;
struct lyd_node *prev_node = NULL, *elem, *node = NULL, *target;
uint64_t pos;
assert(path && start);
if (lysc_data_parent(path[0].node)) {
/* relative path, start from the parent children */
start = lyd_child(start);
} else {
/* absolute path, start from the first top-level sibling */
while (start->parent) {
start = lyd_parent(start);
}
while (start->prev->next) {
start = start->prev;
}
}
LY_ARRAY_FOR(path, u) {
switch (path[u].pred_type) {
case LY_PATH_PREDTYPE_POSITION:
/* we cannot use hashes and want an instance on a specific position */
pos = 1;
node = NULL;
LYD_LIST_FOR_INST(start, path[u].node, elem) {
if (pos == path[u].predicates[0].position) {
node = elem;
break;
}
++pos;
}
break;
case LY_PATH_PREDTYPE_LEAFLIST:
/* we will use hashes to find one leaf-list instance */
LY_CHECK_RET(lyd_create_term2(path[u].node, &path[u].predicates[0].value, &target));
lyd_find_sibling_first(start, target, &node);
lyd_free_tree(target);
break;
case LY_PATH_PREDTYPE_LIST:
/* we will use hashes to find one list instance */
LY_CHECK_RET(lyd_create_list(path[u].node, path[u].predicates, &target));
lyd_find_sibling_first(start, target, &node);
lyd_free_tree(target);
break;
case LY_PATH_PREDTYPE_NONE:
/* we will use hashes to find one any/container/leaf instance */
lyd_find_sibling_val(start, path[u].node, NULL, 0, &node);
break;
}
if (!node) {
/* no matching nodes */
break;
}
/* rememeber previous node */
prev_node = node;
/* next path segment, if any */
start = lyd_child(node);
}
if (node) {
/* we have found the full path */
if (path_idx) {
*path_idx = u;
}
if (match) {
*match = node;
}
return LY_SUCCESS;
} else if (prev_node) {
/* we have found only some partial match */
if (path_idx) {
*path_idx = u - 1;
}
if (match) {
*match = prev_node;
}
return LY_EINCOMPLETE;
}
/* we have not found any nodes */
if (path_idx) {
*path_idx = 0;
}
if (match) {
*match = NULL;
}
return LY_ENOTFOUND;
}
LY_ERR
ly_path_eval(const struct ly_path *path, const struct lyd_node *start, struct lyd_node **match)
{
LY_ERR ret;
struct lyd_node *m;
ret = ly_path_eval_partial(path, start, NULL, &m);
if (ret == LY_SUCCESS) {
/* last node was found */
if (match) {
*match = m;
}
return LY_SUCCESS;
}
/* not a full match */
if (match) {
*match = NULL;
}
return LY_ENOTFOUND;
}
LY_ERR
ly_path_dup(const struct ly_ctx *ctx, const struct ly_path *path, struct ly_path **dup)
{
LY_ARRAY_COUNT_TYPE u, v;
if (!path) {
return LY_SUCCESS;
}
LY_ARRAY_CREATE_RET(ctx, *dup, LY_ARRAY_COUNT(path), LY_EMEM);
LY_ARRAY_FOR(path, u) {
LY_ARRAY_INCREMENT(*dup);
(*dup)[u].node = path[u].node;
if (path[u].predicates) {
LY_ARRAY_CREATE_RET(ctx, (*dup)[u].predicates, LY_ARRAY_COUNT(path[u].predicates), LY_EMEM);
(*dup)[u].pred_type = path[u].pred_type;
LY_ARRAY_FOR(path[u].predicates, v) {
struct ly_path_predicate *pred = &path[u].predicates[v];
LY_ARRAY_INCREMENT((*dup)[u].predicates);
switch (path[u].pred_type) {
case LY_PATH_PREDTYPE_POSITION:
/* position-predicate */
(*dup)[u].predicates[v].position = pred->position;
break;
case LY_PATH_PREDTYPE_LIST:
case LY_PATH_PREDTYPE_LEAFLIST:
/* key-predicate or leaf-list-predicate */
(*dup)[u].predicates[v].key = pred->key;
pred->value.realtype->plugin->duplicate(ctx, &pred->value, &(*dup)[u].predicates[v].value);
LY_ATOMIC_INC_BARRIER(((struct lysc_type *)pred->value.realtype)->refcount);
break;
case LY_PATH_PREDTYPE_NONE:
break;
}
}
}
}
return LY_SUCCESS;
}
void
ly_path_predicates_free(const struct ly_ctx *ctx, enum ly_path_pred_type pred_type, struct ly_path_predicate *predicates)
{
LY_ARRAY_COUNT_TYPE u;
if (!predicates) {
return;
}
LY_ARRAY_FOR(predicates, u) {
switch (pred_type) {
case LY_PATH_PREDTYPE_POSITION:
case LY_PATH_PREDTYPE_NONE:
/* nothing to free */
break;
case LY_PATH_PREDTYPE_LIST:
case LY_PATH_PREDTYPE_LEAFLIST:
if (predicates[u].value.realtype) {
predicates[u].value.realtype->plugin->free(ctx, &predicates[u].value);
lysc_type_free((struct ly_ctx *)ctx, (struct lysc_type *)predicates[u].value.realtype);
}
break;
}
}
LY_ARRAY_FREE(predicates);
}
void
ly_path_free(const struct ly_ctx *ctx, struct ly_path *path)
{
LY_ARRAY_COUNT_TYPE u;
if (!path) {
return;
}
LY_ARRAY_FOR(path, u) {
ly_path_predicates_free(ctx, path[u].pred_type, path[u].predicates);
}
LY_ARRAY_FREE(path);
}