diff options
Diffstat (limited to 'src/path.c')
| -rw-r--r-- | src/path.c | 1503 |
1 files changed, 1503 insertions, 0 deletions
diff --git a/src/path.c b/src/path.c new file mode 100644 index 0000000..9a77414 --- /dev/null +++ b/src/path.c @@ -0,0 +1,1503 @@ +/** + * @file path.c + * @author Michal Vasko <mvasko@cesnet.cz> + * @brief Path functions + * + * Copyright (c) 2020 - 2023 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 + */ + +#define _GNU_SOURCE + +#include "path.h" + +#include <assert.h> +#include <stdlib.h> +#include <string.h> + +#include "compat.h" +#include "log.h" +#include "ly_common.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, uint16_t prefix, uint16_t pred) +{ + LY_ERR ret = LY_SUCCESS; + struct ly_set *set = NULL; + uint32_t i; + const char *name; + size_t name_len; + + if (cur_node) { + LOG_LOCSET(cur_node, 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.", (int)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.", (int)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) && + lysp_check_identifierchar(NULL, ((char *)set->objs[i])[name_len], 0, NULL)) { + 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); + + /* fill repeat */ + exp->repeat[*tok_idx - 2] = calloc(2, sizeof *exp->repeat[*tok_idx]); + LY_CHECK_ERR_GOTO(!exp->repeat[*tok_idx - 2], LOGMEM(NULL); ret = LY_EMEM, cleanup); + exp->repeat[*tok_idx - 2][0] = LYXP_EXPR_EQUALITY; + + /* Literal, Number, or VariableReference */ + if (lyxp_next_token(NULL, exp, tok_idx, LYXP_TOKEN_LITERAL) && + lyxp_next_token(NULL, exp, tok_idx, LYXP_TOKEN_NUMBER) && + lyxp_next_token(NULL, exp, tok_idx, LYXP_TOKEN_VARREF)) { + /* error */ + lyxp_next_token(ctx, exp, tok_idx, LYXP_TOKEN_LITERAL); + goto 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); + + /* fill repeat */ + exp->repeat[*tok_idx - 2] = calloc(2, sizeof *exp->repeat[*tok_idx]); + LY_CHECK_ERR_GOTO(!exp->repeat[*tok_idx - 2], LOGMEM(NULL); ret = LY_EMEM, cleanup); + exp->repeat[*tok_idx - 2][0] = LYXP_EXPR_EQUALITY; + + /* 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 */ + + /* check for index 0 */ + if (!atoi(exp->expr + exp->tok_pos[*tok_idx - 1])) { + LOGVAL(ctx, LYVE_XPATH, "Invalid positional predicate \"%.*s\".", (int)exp->tok_len[*tok_idx - 1], + exp->expr + exp->tok_pos[*tok_idx - 1]); + goto token_error; + } + + /* ']' */ + 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) && + lysp_check_identifierchar(NULL, ((char *)set->objs[i])[name_len], 0, NULL)) { + 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); + + /* fill repeat */ + exp->repeat[*tok_idx - 2] = calloc(2, sizeof *exp->repeat[*tok_idx]); + LY_CHECK_ERR_GOTO(!exp->repeat[*tok_idx - 2], LOGMEM(NULL); ret = LY_EMEM, cleanup); + exp->repeat[*tok_idx - 2][0] = LYXP_EXPR_EQUALITY; + + /* 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.", + (int)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 if (lyxp_check_token(ctx, exp, *tok_idx, 0)) { + /* unexpected EOF */ + goto token_error; + } else { + /* invalid token */ + 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); + ly_set_free(set, NULL); + return ret; + +token_error: + LOG_LOCBACK(cur_node ? 1 : 0, 0); + ly_set_free(set, NULL); + return LY_EVALID; +} + +/** + * @brief Parse deref XPath function and perform all additional checks. + * + * @param[in] ctx libyang context. + * @param[in] ctx_node Optional context node, used for logging. + * @param[in] exp Parsed path. + * @param[in,out] tok_idx Index in @p exp, is adjusted. + * @return LY_ERR value. + */ +static LY_ERR +ly_path_parse_deref(const struct ly_ctx *ctx, const struct lysc_node *ctx_node, const struct lyxp_expr *exp, + uint32_t *tok_idx) +{ + size_t arg_len; + uint32_t begin_token, end_token; + struct lyxp_expr *arg_expr = NULL; + + /* mandatory FunctionName */ + LY_CHECK_RET(lyxp_next_token(ctx, exp, tok_idx, LYXP_TOKEN_FUNCNAME), LY_EVALID); + if (!strncmp(&exp->expr[exp->tok_pos[*tok_idx]], "deref", 5)) { + LOGVAL(ctx, LYVE_XPATH, "Unexpected XPath function \"%.*s\" in path, expected \"deref(...)\"", + (int)exp->tok_len[*tok_idx], exp->expr + exp->tok_pos[*tok_idx]); + return LY_EVALID; + } + + /* mandatory '(' */ + LY_CHECK_RET(lyxp_next_token(ctx, exp, tok_idx, LYXP_TOKEN_PAR1), LY_EVALID); + begin_token = *tok_idx; + + /* count tokens till ')' */ + while (lyxp_check_token(NULL, exp, *tok_idx, LYXP_TOKEN_PAR2) && *tok_idx < exp->used) { + /* emebedded functions are not allowed */ + if (!lyxp_check_token(NULL, exp, *tok_idx, LYXP_TOKEN_FUNCNAME)) { + LOGVAL(ctx, LYVE_XPATH, "Embedded function XPath function inside deref function within the path" + "is not allowed"); + return LY_EVALID; + } + + (*tok_idx)++; + } + + /* mandatory ')' */ + LY_CHECK_RET(lyxp_next_token(ctx, exp, tok_idx, LYXP_TOKEN_PAR2), LY_EVALID); + end_token = *tok_idx - 1; + + /* parse the path of deref argument */ + arg_len = exp->tok_pos[end_token] - exp->tok_pos[begin_token]; + LY_CHECK_RET(ly_path_parse(ctx, ctx_node, &exp->expr[exp->tok_pos[begin_token]], arg_len, 1, + LY_PATH_BEGIN_EITHER, LY_PATH_PREFIX_OPTIONAL, LY_PATH_PRED_LEAFREF, &arg_expr), LY_EVALID); + lyxp_expr_free(ctx, arg_expr); + + return LY_SUCCESS; +} + +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, uint16_t begin, uint16_t prefix, uint16_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; + ly_bool is_abs; + + 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_FIRST) || (prefix == LY_PATH_PREFIX_STRICT_INHERIT)); + assert((pred == LY_PATH_PRED_KEYS) || (pred == LY_PATH_PRED_SIMPLE) || (pred == LY_PATH_PRED_LEAFREF)); + + if (ctx_node) { + LOG_LOCSET(ctx_node, NULL); + } + + /* parse as a generic XPath expression, reparse is performed manually */ + LY_CHECK_GOTO(ret = lyxp_expr_parse(ctx, str_path, path_len, 0, &exp), error); + tok_idx = 0; + + /* alloc empty repeat (only '=', filled manually) */ + exp->repeat = calloc(exp->size, sizeof *exp->repeat); + LY_CHECK_ERR_GOTO(!exp->repeat, LOGMEM(ctx); ret = LY_EMEM, error); + + 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) { + /* optional function 'deref..' */ + if ((ly_ctx_get_options(ctx) & LY_CTX_LEAFREF_EXTENDED) && + !lyxp_check_token(NULL, exp, tok_idx, LYXP_TOKEN_FUNCNAME)) { + LY_CHECK_ERR_GOTO(ly_path_parse_deref(ctx, ctx_node, exp, &tok_idx), ret = LY_EVALID, error); + + /* '/' */ + LY_CHECK_ERR_GOTO(lyxp_next_token(ctx, exp, &tok_idx, LYXP_TOKEN_OPER_PATH), ret = LY_EVALID, + error); + } + + /* 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)); + } + + is_abs = 0; + } else { + is_abs = 1; + } + } else { + /* '/' */ + LY_CHECK_ERR_GOTO(lyxp_next_token(ctx, exp, &tok_idx, LYXP_TOKEN_OPER_PATH), ret = LY_EVALID, error); + + is_abs = 1; + } + + 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.", (int)cur_len, cur_node); + ret = LY_EVALID; + goto error; + } + } else if ((prefix == LY_PATH_PREFIX_FIRST) || (prefix == LY_PATH_PREFIX_STRICT_INHERIT)) { + if (!prev_prefix && is_abs) { + /* the first node must have a prefix */ + if (!strnstr(cur_node, ":", cur_len)) { + LOGVAL(ctx, LYVE_XPATH, "Prefix missing for \"%.*s\" in path.", (int)cur_len, cur_node); + ret = LY_EVALID; + goto error; + } + + /* remember the first prefix */ + prev_prefix = cur_node; + } else if (prev_prefix && (prefix == LY_PATH_PREFIX_STRICT_INHERIT)) { + /* 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.", (int)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); + return LY_SUCCESS; + +error: + lyxp_expr_free(ctx, exp); + LOG_LOCBACK(ctx_node ? 1 : 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, uint16_t prefix, uint16_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)); + + if (cur_node) { + LOG_LOCSET(cur_node, NULL); + } + + /* parse as a generic XPath expression, reparse is performed manually */ + LY_CHECK_GOTO(ret = lyxp_expr_parse(ctx, str_path, path_len, 0, &exp), error); + tok_idx = 0; + + /* alloc empty repeat (only '=', filled manually) */ + exp->repeat = calloc(exp->size, sizeof *exp->repeat); + LY_CHECK_ERR_GOTO(!exp->repeat, LOGMEM(ctx); ret = LY_EMEM, error); + + 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); + return LY_SUCCESS; + +error: + lyxp_expr_free(ctx, exp); + LOG_LOCBACK(cur_node ? 1 : 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) { + if (cur_node) { + LOG_LOCSET(cur_node, 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); + } 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); + 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) +{ + 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); + + if (cur_node) { + LOG_LOCSET(cur_node, NULL); + } + + *predicates = NULL; + + 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); + + /* new predicate */ + LY_ARRAY_NEW_GOTO(ctx, *predicates, p, ret, cleanup); + p->key = key; + + /* '=' */ + assert(expr->tokens[*tok_idx] == LYXP_TOKEN_OPER_EQUAL); + ++(*tok_idx); + + /* Literal, Number, or VariableReference */ + if (expr->tokens[*tok_idx] == LYXP_TOKEN_VARREF) { + /* store the variable name */ + p->variable = strndup(expr->expr + expr->tok_pos[*tok_idx], expr->tok_len[*tok_idx]); + LY_CHECK_ERR_GOTO(!p->variable, LOGMEM(ctx); ret = LY_EMEM, cleanup); + + p->type = LY_PATH_PREDTYPE_LIST_VAR; + ++(*tok_idx); + } else { + 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 { + assert(expr->tokens[*tok_idx] == LYXP_TOKEN_NUMBER); + val = expr->expr + expr->tok_pos[*tok_idx]; + val_len = expr->tok_len[*tok_idx]; + } + + /* store the value */ + LOG_LOCSET(key, NULL); + ret = lyd_value_store(ctx, &p->value, ((struct lysc_node_leaf *)key)->type, val, val_len, 0, 0, + NULL, format, prefix_data, LYD_HINT_DATA, key, NULL); + LOG_LOCBACK(1, 0); + LY_CHECK_ERR_GOTO(ret, p->value.realtype = NULL, cleanup); + + /* "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); + + p->type = LY_PATH_PREDTYPE_LIST; + ++(*tok_idx); + } + + /* ']' */ + 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, *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 */ + LY_ARRAY_NEW_GOTO(ctx, *predicates, p, ret, cleanup); + p->type = LY_PATH_PREDTYPE_LEAFLIST; + + /* '=' */ + 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 */ + if (ctx_node) { + LOG_LOCSET(ctx_node, NULL); + } + ret = lyd_value_store(ctx, &p->value, ((struct lysc_node_leaflist *)ctx_node)->type, val, val_len, 0, 0, + NULL, format, prefix_data, LYD_HINT_DATA, ctx_node, NULL); + LOG_LOCBACK(ctx_node ? 1 : 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 */ + LY_ARRAY_NEW_GOTO(ctx, *predicates, p, ret, cleanup); + p->type = LY_PATH_PREDTYPE_POSITION; + + /* 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); + 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; + + 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: + return (ret == LY_ENOTFOUND) ? LY_EVALID : ret; +} + +/** + * @brief Duplicate ly_path_predicate structure. + * + * @param[in] ctx libyang context. + * @param[in] pred The array of path predicates. + * @param[out] dup Duplicated predicates. + * @return LY_ERR value. + */ +static LY_ERR +ly_path_dup_predicates(const struct ly_ctx *ctx, const struct ly_path_predicate *pred, struct ly_path_predicate **dup) +{ + LY_ARRAY_COUNT_TYPE u; + + if (!pred) { + return LY_SUCCESS; + } + + LY_ARRAY_CREATE_RET(ctx, *dup, LY_ARRAY_COUNT(pred), LY_EMEM); + LY_ARRAY_FOR(pred, u) { + LY_ARRAY_INCREMENT(*dup); + (*dup)[u].type = pred->type; + + switch (pred[u].type) { + case LY_PATH_PREDTYPE_POSITION: + /* position-predicate */ + (*dup)[u].position = pred[u].position; + break; + case LY_PATH_PREDTYPE_LIST: + case LY_PATH_PREDTYPE_LEAFLIST: + /* key-predicate or leaf-list-predicate */ + (*dup)[u].key = pred[u].key; + pred[u].value.realtype->plugin->duplicate(ctx, &pred[u].value, &(*dup)[u].value); + LY_ATOMIC_INC_BARRIER(((struct lysc_type *)pred[u].value.realtype)->refcount); + break; + case LY_PATH_PREDTYPE_LIST_VAR: + /* key-predicate with a variable */ + (*dup)[u].key = pred[u].key; + (*dup)[u].variable = strdup(pred[u].variable); + break; + } + } + + return LY_SUCCESS; +} + +/** + * @brief Appends path elements from source to destination array + * + * @param[in] ctx libyang context. + * @param[in] src The source path + * @param[in,out] dst The destination path + * @return LY_ERR value. + */ +static LY_ERR +ly_path_append(const struct ly_ctx *ctx, const struct ly_path *src, struct ly_path **dst) +{ + LY_ERR ret = LY_SUCCESS; + LY_ARRAY_COUNT_TYPE u; + struct ly_path *p; + + if (!src) { + return LY_SUCCESS; + } + + LY_ARRAY_CREATE_RET(ctx, *dst, LY_ARRAY_COUNT(src), LY_EMEM); + LY_ARRAY_FOR(src, u) { + LY_ARRAY_NEW_GOTO(ctx, *dst, p, ret, cleanup); + p->node = src[u].node; + p->ext = src[u].ext; + LY_CHECK_GOTO(ret = ly_path_dup_predicates(ctx, src[u].predicates, &p->predicates), cleanup); + } + +cleanup: + return ret; +} + +/** + * @brief Compile deref XPath function into ly_path structure. + * + * @param[in] ctx libyang context. + * @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] 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[in,out] tok_idx Index in @p exp, is adjusted. + * @param[out] path Compiled path. + * @return LY_ERR value. + */ +static LY_ERR +ly_path_compile_deref(const struct ly_ctx *ctx, const struct lysc_node *ctx_node, + const struct lysc_ext_instance *top_ext, const struct lyxp_expr *expr, uint16_t oper, uint16_t target, + LY_VALUE_FORMAT format, void *prefix_data, uint32_t *tok_idx, struct ly_path **path) +{ + LY_ERR ret = LY_SUCCESS; + struct lyxp_expr expr2; + struct ly_path *path2 = NULL; + const struct lysc_node *node2; + const struct lysc_node_leaf *deref_leaf_node; + const struct lysc_type_leafref *lref; + uint32_t begin_token; + + *path = NULL; + + /* properly parsed path must always starts with 'deref' and '(' */ + assert(!lyxp_check_token(NULL, expr, *tok_idx, LYXP_TOKEN_FUNCNAME)); + assert(!strncmp(&expr->expr[expr->tok_pos[*tok_idx]], "deref", 5)); + (*tok_idx)++; + assert(!lyxp_check_token(NULL, expr, *tok_idx, LYXP_TOKEN_PAR1)); + (*tok_idx)++; + begin_token = *tok_idx; + + /* emebedded functions were already identified count tokens till ')' */ + while (lyxp_check_token(NULL, expr, *tok_idx, LYXP_TOKEN_PAR2) && (*tok_idx < expr->used)) { + (*tok_idx)++; + } + + /* properly parsed path must have ')' within the tokens */ + assert(!lyxp_check_token(NULL, expr, *tok_idx, LYXP_TOKEN_PAR2)); + + /* prepare expr representing just deref arg */ + expr2.tokens = &expr->tokens[begin_token]; + expr2.tok_pos = &expr->tok_pos[begin_token]; + expr2.tok_len = &expr->tok_len[begin_token]; + expr2.repeat = &expr->repeat[begin_token]; + expr2.used = *tok_idx - begin_token; + expr2.size = expr->size - begin_token; + expr2.expr = expr->expr; + + /* compile just deref arg, append it to the path and find dereferenced lref for next operations */ + LY_CHECK_GOTO(ret = ly_path_compile_leafref(ctx, ctx_node, top_ext, &expr2, oper, target, format, prefix_data, + &path2), cleanup); + node2 = path2[LY_ARRAY_COUNT(path2) - 1].node; + if ((node2->nodetype != LYS_LEAF) && (node2->nodetype != LYS_LEAFLIST)) { + LOGVAL(ctx, LYVE_XPATH, "The deref function target node \"%s\" is not leaf nor leaflist", node2->name); + ret = LY_EVALID; + goto cleanup; + } + deref_leaf_node = (const struct lysc_node_leaf *)node2; + if (deref_leaf_node->type->basetype != LY_TYPE_LEAFREF) { + LOGVAL(ctx, LYVE_XPATH, "The deref function target node \"%s\" is not leafref", node2->name); + ret = LY_EVALID; + goto cleanup; + } + lref = (const struct lysc_type_leafref *)deref_leaf_node->type; + LY_CHECK_GOTO(ret = ly_path_append(ctx, path2, path), cleanup); + ly_path_free(ctx, path2); + path2 = NULL; + + /* compile dereferenced leafref expression and append it to the path */ + LY_CHECK_GOTO(ret = ly_path_compile_leafref(ctx, node2, top_ext, lref->path, oper, target, format, prefix_data, + &path2), cleanup); + node2 = path2[LY_ARRAY_COUNT(path2) - 1].node; + LY_CHECK_GOTO(ret = ly_path_append(ctx, path2, path), cleanup); + ly_path_free(ctx, path2); + path2 = NULL; + + /* properly parsed path must always continue with ')' and '/' */ + assert(!lyxp_check_token(NULL, expr, *tok_idx, LYXP_TOKEN_PAR2)); + (*tok_idx)++; + assert(!lyxp_check_token(NULL, expr, *tok_idx, LYXP_TOKEN_OPER_PATH)); + (*tok_idx)++; + + /* prepare expr representing rest of the path after deref */ + expr2.tokens = &expr->tokens[*tok_idx]; + expr2.tok_pos = &expr->tok_pos[*tok_idx]; + expr2.tok_len = &expr->tok_len[*tok_idx]; + expr2.repeat = &expr->repeat[*tok_idx]; + expr2.used = expr->used - *tok_idx; + expr2.size = expr->size - *tok_idx; + expr2.expr = expr->expr; + + /* compile rest of the path and append it to the path */ + LY_CHECK_GOTO(ret = ly_path_compile_leafref(ctx, node2, top_ext, &expr2, oper, target, format, prefix_data, &path2), + cleanup); + LY_CHECK_GOTO(ret = ly_path_append(ctx, path2, path), cleanup); + +cleanup: + ly_path_free(ctx, path2); + if (ret) { + ly_path_free(ctx, *path); + *path = NULL; + } + return 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, uint16_t oper, uint16_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; + if (cur_node) { + LOG_LOCSET(cur_node, NULL); + } + + if (oper == LY_PATH_OPER_OUTPUT) { + getnext_opts = LYS_GETNEXT_OUTPUT; + } else { + getnext_opts = 0; + } + + if (lref && (ly_ctx_get_options(ctx) & LY_CTX_LEAFREF_EXTENDED) && + (expr->tokens[tok_idx] == LYXP_TOKEN_FUNCNAME)) { + /* deref function */ + ret = ly_path_compile_deref(ctx, ctx_node, top_ext, expr, oper, target, format, prefix_data, &tok_idx, path); + goto cleanup; + } else 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); + } + 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(cur_node ? 1 : 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, uint16_t oper, uint16_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, uint16_t oper, uint16_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, const struct lyxp_var *vars, + ly_bool with_opaq, 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) { + if (path[u].predicates) { + switch (path[u].predicates[0].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_VAR: + 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, vars, 1, &target)); + lyd_find_sibling_first(start, target, &node); + lyd_free_tree(target); + break; + } + } else { + /* we will use hashes to find one any/container/leaf instance */ + if (lyd_find_sibling_val(start, path[u].node, NULL, 0, &node) && with_opaq) { + if (!lyd_find_sibling_opaq_next(start, path[u].node->name, &node) && + (lyd_node_module(node) != path[u].node->module)) { + /* non-matching opaque node */ + node = NULL; + } + } + } + + 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, const struct lyxp_var *vars, struct lyd_node **match) +{ + LY_ERR ret; + struct lyd_node *m; + + ret = ly_path_eval_partial(path, start, vars, 0, 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_ERR ret = LY_SUCCESS; + LY_ARRAY_COUNT_TYPE u; + + 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; + (*dup)[u].ext = path[u].ext; + LY_CHECK_RET(ret = ly_path_dup_predicates(ctx, path[u].predicates, &(*dup)[u].predicates), ret); + } + + return LY_SUCCESS; +} + +void +ly_path_predicates_free(const struct ly_ctx *ctx, struct ly_path_predicate *predicates) +{ + LY_ARRAY_COUNT_TYPE u; + struct lysf_ctx fctx = {.ctx = (struct ly_ctx *)ctx}; + + if (!predicates) { + return; + } + + LY_ARRAY_FOR(predicates, u) { + switch (predicates[u].type) { + case LY_PATH_PREDTYPE_POSITION: + /* 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(&fctx, (struct lysc_type *)predicates[u].value.realtype); + } + break; + case LY_PATH_PREDTYPE_LIST_VAR: + free(predicates[u].variable); + 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].predicates); + } + LY_ARRAY_FREE(path); +} |