src/parser_yang.c

/**
 * @file parser_yang.c
 * @author Pavol Vican
 * @brief YANG parser for libyang
 *
 * Copyright (c) 2015 CESNET, z.s.p.o.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name of the Company nor the names of its contributors
 *    may be used to endorse or promote products derived from this
 *    software without specific prior written permission.
 */

#include <ctype.h>
#include <pcre.h>
#include "parser_yang.h"
#include "parser_yang_bis.h"
#include "parser.h"
#include "xpath.h"

static int 
yang_check_string(struct lys_module *module, const char **target, char *what, char *where, char *value, int line)
{
    if (*target) {
        LOGVAL(LYE_TOOMANY, line, LY_VLOG_NONE, NULL, what, where);
        free(value);
        return 1;
    } else {
        *target = lydict_insert_zc(module->ctx, value);
        return 0;
    }
}

int 
yang_read_common(struct lys_module *module, char *value, int type, int line) 
{
    int ret = 0;

    switch (type) {
    case MODULE_KEYWORD:
        module->name = lydict_insert_zc(module->ctx, value);
        break;
    case NAMESPACE_KEYWORD:
        ret = yang_check_string(module, &module->ns, "namespace", "module", value, line);
        break;
    case ORGANIZATION_KEYWORD:
        ret = yang_check_string(module, &module->org, "organization", "module", value, line);
        break;
    case CONTACT_KEYWORD:
        ret = yang_check_string(module, &module->contact, "contact", "module", value, line);
        break;
    }

    return ret;
}

int 
yang_read_prefix(struct lys_module *module, void *save, char *value, int type, int line) 
{
    int ret = 0;

    if (lyp_check_identifier(value, LY_IDENT_PREFIX, line, module, NULL)) {
        free(value);
        return EXIT_FAILURE;
    }
    switch (type){
    case MODULE_KEYWORD:
        ret = yang_check_string(module, &module->prefix, "prefix", "module", value, line);
        break;
    case IMPORT_KEYWORD:
        ((struct lys_import *)save)->prefix = lydict_insert_zc(module->ctx, value);
        break;
    }

    return ret;
}

void *
yang_elem_of_array(void **ptr, uint8_t *act_size, int type, int sizeof_struct)
{
    void *retval;

    if (!(*act_size % LY_ARRAY_SIZE) && !(*ptr = ly_realloc(*ptr, (*act_size + LY_ARRAY_SIZE) * sizeof_struct))) {
        LOGMEM;
        return NULL;
    }
    switch (type) {
    case IMPORT_KEYWORD:
        retval = &((struct lys_import *)(*ptr))[*act_size];
        break;
    case REVISION_KEYWORD:
        retval = &((struct lys_revision *)(*ptr))[*act_size];
        break;
    }
    (*act_size)++;
    memset(retval,0,sizeof_struct);
    return retval;
}

int
yang_fill_import(struct lys_module *module, struct lys_import *imp, char *value, int line)
{
    int count, i;

    /* check for circular import, store it if passed */
    if (!module->ctx->models.parsing) {
        count = 0;
    } else {
        for (count = 0; module->ctx->models.parsing[count]; ++count) {
            if (value == module->ctx->models.parsing[count]) {
                LOGERR(LY_EVALID, "Circular import dependency on the module \"%s\".", value);
                goto error;
            }
        }
    }
    ++count;
    module->ctx->models.parsing =
            ly_realloc(module->ctx->models.parsing, (count + 1) * sizeof *module->ctx->models.parsing);
    if (!module->ctx->models.parsing) {
        LOGMEM;
        goto error;
    }
    module->ctx->models.parsing[count - 1] = value;
    module->ctx->models.parsing[count] = NULL;

    /* try to load the module */
    imp->module = (struct lys_module *)ly_ctx_get_module(module->ctx, value, imp->rev[0] ? imp->rev : NULL);
    if (!imp->module) {
        /* whether to use a user callback is decided in the function */
        imp->module = (struct lys_module *)ly_ctx_load_module(module->ctx, value, imp->rev[0] ? imp->rev : NULL);
    }

    /* remove the new module name now that its parsing is finished (even if failed) */
    if (module->ctx->models.parsing[count] || (module->ctx->models.parsing[count - 1] != value)) {
        LOGINT;
    }
    --count;
    if (count) {
        module->ctx->models.parsing[count] = NULL;
    } else {
        free(module->ctx->models.parsing);
        module->ctx->models.parsing = NULL;
    }

    /* check the result */
    if (!imp->module) {
        LOGERR(LY_EVALID, "Importing \"%s\" module into \"%s\" failed.", value, module->name);
        goto error;
    }

    module->imp_size++;

    /* check duplicities in imported modules */
    for (i = 0; i < module->imp_size - 1; i++) {
        if (!strcmp(module->imp[i].module->name, module->imp[module->imp_size - 1].module->name)) {
            LOGVAL(LYE_SPEC, line, LY_VLOG_NONE, NULL, "Importing module \"%s\" repeatedly.", module->imp[i].module->name);
            goto error;
        }
    }

    free(value);
    return EXIT_SUCCESS;

    error:

    free(value);
    return EXIT_FAILURE;
}

int
yang_read_description(struct lys_module *module, void *node, char *value, int type, int line)
{
    int ret;

    if (!node) {
        ret = yang_check_string(module, &module->dsc, "description", "module", value, line);
    } else {
        switch (type) {
        case REVISION_KEYWORD:
            ret = yang_check_string(module, &((struct lys_revision *) node)->dsc, "description", "revision", value, line);
            break;
        case FEATURE_KEYWORD:
            ret = yang_check_string(module, &((struct lys_feature *) node)->dsc, "description", "feature", value, line);
            break;
        case IDENTITY_KEYWORD:
            ret = yang_check_string(module, &((struct lys_ident *) node)->dsc, "description", "identity", value, line);
            break;
        case MUST_KEYWORD:
            ret = yang_check_string(module, &((struct lys_restr *) node)->dsc, "description", "must", value, line);
            break;
        case WHEN_KEYWORD:
            ret = yang_check_string(module, &((struct lys_when *) node)->dsc, "description", "when" , value, line);
            break;
        case CONTAINER_KEYWORD:
            ret = yang_check_string(module, &((struct lys_node_container *) node)->dsc, "description", "container", value, line);
            break;
        case ANYXML_KEYWORD:
            ret = yang_check_string(module, &((struct lys_node_anyxml *) node)->dsc, "description", "anyxml", value, line);
            break;
        case CHOICE_KEYWORD:
            ret = yang_check_string(module, &((struct lys_node_choice *) node)->dsc, "description", "choice", value, line);
            break;
        case CASE_KEYWORD:
            ret = yang_check_string(module, &((struct lys_node_case *) node)->dsc, "description", "case", value, line);
            break;
        case GROUPING_KEYWORD:
            ret = yang_check_string(module, &((struct lys_node_grp *) node)->dsc, "description", "grouping", value, line);
            break;
        case LEAF_KEYWORD:
            ret = yang_check_string(module, &((struct lys_node_leaf *) node)->dsc, "description", "leaf", value, line);
            break;
        case LEAF_LIST_KEYWORD:
            ret = yang_check_string(module, &((struct lys_node_leaflist *) node)->dsc, "description", "leaflist", value, line);
            break;
        case LIST_KEYWORD:
            ret = yang_check_string(module, &((struct lys_node_list *) node)->dsc, "description", "list", value, line);
            break;
        case LENGTH_KEYWORD:
            ret = yang_check_string(module, &((struct lys_restr *) node)->dsc, "description", "length", value, line);
            break;
        case PATTERN_KEYWORD:
            ret = yang_check_string(module, &((struct lys_restr *) node)->dsc, "description", "pattern", value, line);
            break;
        case RANGE_KEYWORD:
            ret = yang_check_string(module, &((struct lys_restr *) node)->dsc, "description", "range", value, line);
            break;
        case ENUM_KEYWORD:
            ret = yang_check_string(module, &((struct lys_type_enum *) node)->dsc, "description", "enum", value, line);
            break;
        case BIT_KEYWORD:
            ret = yang_check_string(module, &((struct lys_type_bit *) node)->dsc, "description", "bit", value, line);
            break;
        case TYPEDEF_KEYWORD:
            ret = yang_check_string(module, &((struct lys_tpdf *) node)->dsc, "description", "typedef", value, line);
            break;
        }
    }
    return ret;
}

int
yang_read_reference(struct lys_module *module, void *node, char *value, int type, int line)
{
    int ret;

    if (!node) {
        ret = yang_check_string(module, &module->ref, "reference", "module", value, line);
    } else {
        switch (type) {
        case REVISION_KEYWORD:
            ret = yang_check_string(module, &((struct lys_revision *) node)->ref, "reference", "revision", value, line);
            break;
        case FEATURE_KEYWORD:
            ret = yang_check_string(module, &((struct lys_feature *) node)->ref, "reference", "feature", value, line);
            break;
        case IDENTITY_KEYWORD:
            ret = yang_check_string(module, &((struct lys_ident *) node)->ref, "reference", "identity", value, line);
            break;
        case MUST_KEYWORD:
            ret = yang_check_string(module, &((struct lys_restr *) node)->ref, "reference", "must", value, line);
            break;
        case WHEN_KEYWORD:
            ret = yang_check_string(module, &((struct lys_when *) node)->ref, "reference", "when", value, line);
            break;
        case CONTAINER_KEYWORD:
            ret = yang_check_string(module, &((struct lys_node_container *) node)->ref, "reference", "container", value, line);
            break;
        case ANYXML_KEYWORD:
            ret = yang_check_string(module, &((struct lys_node_anyxml *) node)->ref, "reference", "anyxml", value, line);
            break;
        case CHOICE_KEYWORD:
            ret = yang_check_string(module, &((struct lys_node_anyxml *) node)->ref, "reference", "choice", value, line);
            break;
        case CASE_KEYWORD:
            ret = yang_check_string(module, &((struct lys_node_anyxml *) node)->ref, "reference", "case", value, line);
            break;
        case GROUPING_KEYWORD:
            ret = yang_check_string(module, &((struct lys_node_grp *) node)->ref, "reference", "grouping", value, line);
            break;
        case LEAF_KEYWORD:
            ret = yang_check_string(module, &((struct lys_node_leaf *) node)->ref, "reference", "leaf", value, line);
            break;
        case LEAF_LIST_KEYWORD:
            ret = yang_check_string(module, &((struct lys_node_leaflist *) node)->ref, "reference", "leaflist", value, line);
            break;
        case LIST_KEYWORD:
            ret = yang_check_string(module, &((struct lys_node_list *) node)->ref, "reference", "list", value, line);
            break;
        case LENGTH_KEYWORD:
            ret = yang_check_string(module, &((struct lys_restr *) node)->ref, "reference", "length", value, line);
            break;
        case PATTERN_KEYWORD:
            ret = yang_check_string(module, &((struct lys_restr *) node)->ref, "reference", "pattern", value, line);
            break;
        case RANGE_KEYWORD:
            ret = yang_check_string(module, &((struct lys_restr *) node)->ref, "reference", "range", value, line);
            break;
        case ENUM_KEYWORD:
            ret = yang_check_string(module, &((struct lys_type_enum *) node)->ref, "reference", "enum", value, line);
            break;
        case BIT_KEYWORD:
            ret = yang_check_string(module, &((struct lys_type_bit *) node)->ref, "reference", "bit", value, line);
            break;
        case TYPEDEF_KEYWORD:
            ret = yang_check_string(module, &((struct lys_tpdf *) node)->ref, "reference", "typedef", value, line);
            break;
        }
    }
    return ret;
}

void *
yang_read_revision(struct lys_module *module, char *value)
{
    struct lys_revision *retval;

    retval = &module->rev[module->rev_size];

    /* first member of array is last revision */
    if (module->rev_size && strcmp(module->rev[0].date, value) < 0) {
        memcpy(retval->date, module->rev[0].date, LY_REV_SIZE);
        memcpy(module->rev[0].date, value, LY_REV_SIZE);
        retval->dsc = module->rev[0].dsc;
        retval->ref = module->rev[0].ref;
        retval = module->rev;
        retval->dsc = NULL;
        retval->ref = NULL;
    } else {
        memcpy(retval->date, value, LY_REV_SIZE);
    }
    module->rev_size++;
    free(value);
    return retval;
}

int
yang_add_elem(struct lys_node_array **node, uint32_t *size)
{
    if (!*size % LY_ARRAY_SIZE) {
        if (!(*node = ly_realloc(*node, (*size + LY_ARRAY_SIZE) * sizeof **node))) {
            LOGMEM;
            return EXIT_FAILURE;
        } else {
            memset(*node+*size,0,LY_ARRAY_SIZE*sizeof **node);
        }
    }
    (*size)++;
    return EXIT_SUCCESS;
}

void *
yang_read_feature(struct lys_module *module, char *value, int line)
{
    struct lys_feature *retval;

    /* check uniqueness of feature's names */
    if (lyp_check_identifier(value, LY_IDENT_FEATURE, line, module, NULL)) {
        goto error;
    }
    retval = &module->features[module->features_size];
    retval->name = lydict_insert_zc(module->ctx, value);
    retval->module = module;
    module->features_size++;
    return retval;

error:
    free(value);
    return NULL;
}

int
yang_read_if_feature(struct lys_module *module, void *ptr, char *value, struct unres_schema *unres, int type, int line)
{
    const char *exp;
    int ret;
    struct lys_feature *f;
    struct lys_node *n;

    if (!(exp = transform_schema2json(module, value, line))) {
        free(value);
        return EXIT_FAILURE;
    }
    free(value);

    /* hack - store pointer to the parent node for later status check */
    if (type == FEATURE_KEYWORD) {
        f = (struct lys_feature *) ptr;
        f->features[f->features_size] = f;
        ret = unres_schema_add_str(module, unres, &f->features[f->features_size], UNRES_IFFEAT, exp, line);
        f->features_size++;
    } else {
        n = (struct lys_node *) ptr;
        n->features[n->features_size] = (struct lys_feature *) n;
        ret = unres_schema_add_str(module, unres, &n->features[n->features_size], UNRES_IFFEAT, exp, line);
        n->features_size++;
    }

    lydict_remove(module->ctx, exp);
    if (ret == -1) {

        return EXIT_FAILURE;
    }
    return EXIT_SUCCESS;
}

static int 
yang_check_flags(uint8_t *flags, uint8_t mask, char *what, char *where, int value, int line)
{
    if (*flags & mask) {
        LOGVAL(LYE_TOOMANY, line, LY_VLOG_NONE, NULL, what, where);
        return EXIT_FAILURE;
    } else {
        *flags |= value;
        return EXIT_SUCCESS;
    }
}

int
yang_read_status(void *node, int value, int type, int line)
{
    int retval;

    switch (type) {
    case FEATURE_KEYWORD:
        retval = yang_check_flags(&((struct lys_feature *) node)->flags, LYS_STATUS_MASK, "status", "feature", value, line);
        break;
    case IDENTITY_KEYWORD:
        retval = yang_check_flags(&((struct lys_ident *) node)->flags, LYS_STATUS_MASK, "status", "identity", value, line);
        break;
    case CONTAINER_KEYWORD:
        retval = yang_check_flags(&((struct lys_node_container *) node)->flags, LYS_STATUS_MASK, "status", "container", value, line);
        break;
    case ANYXML_KEYWORD:
        retval = yang_check_flags(&((struct lys_node_anyxml *) node)->flags, LYS_STATUS_MASK, "status", "anyxml", value, line);
        break;
    case CHOICE_KEYWORD:
        retval = yang_check_flags(&((struct lys_node_anyxml *) node)->flags, LYS_STATUS_MASK, "status", "choice", value, line);
        break;
    case CASE_KEYWORD:
        retval = yang_check_flags(&((struct lys_node_case *) node)->flags, LYS_STATUS_MASK, "status", "case", value, line);
        break;
    case GROUPING_KEYWORD:
        retval = yang_check_flags(&((struct lys_node_grp *) node)->flags, LYS_STATUS_MASK, "status", "grouping", value, line);
        break;
    case LEAF_KEYWORD:
        retval = yang_check_flags(&((struct lys_node_leaf *) node)->flags, LYS_STATUS_MASK, "status", "leaf", value, line);
        break;
    case LEAF_LIST_KEYWORD:
        retval = yang_check_flags(&((struct lys_node_leaflist *) node)->flags, LYS_STATUS_MASK, "status", "leaflist", value, line);
        break;
    case LIST_KEYWORD:
        retval = yang_check_flags(&((struct lys_node_list *) node)->flags, LYS_STATUS_MASK, "status", "list", value, line);
        break;
    case ENUM_KEYWORD:
        retval = yang_check_flags(&((struct lys_type_enum *) node)->flags, LYS_STATUS_MASK, "status", "enum", value, line);
        break;
    case BIT_KEYWORD:
        retval = yang_check_flags(&((struct lys_type_bit *) node)->flags, LYS_STATUS_MASK, "status", "bit", value, line);
        break;
    case TYPEDEF_KEYWORD:
        retval = yang_check_flags(&((struct lys_tpdf *) node)->flags, LYS_STATUS_MASK, "status", "typedef", value, line);
        break;
    }
    return retval;
}

void *
yang_read_identity(struct lys_module *module, char *value)
{
    struct lys_ident *ret;

    ret = &module->ident[module->ident_size];
    ret->name = lydict_insert_zc(module->ctx, value);
    ret->module = module;
    module->ident_size++;
    return ret;
}

int
yang_read_base(struct lys_module *module, struct lys_ident *ident, char *value, struct unres_schema *unres, int line)
{
    const char *exp;

    if (ident->base) {
        LOGVAL(LYE_TOOMANY, line, LY_VLOG_NONE, NULL, "base", "identity");
        return EXIT_FAILURE;
    }
    exp = transform_schema2json(module, value, line);
    free(value);
    if (!exp) {
        return EXIT_FAILURE;
    }
    if (unres_schema_add_str(module, unres, ident, UNRES_IDENT, exp, line) == -1) {
        lydict_remove(module->ctx, exp);
        return EXIT_FAILURE;
    }

    /* hack - store some address due to detection of unresolved base*/
    if (!ident->base) {
        ident->base = (void *)1;
    }

    lydict_remove(module->ctx, exp);
    return EXIT_SUCCESS;
}

void *
yang_read_must(struct lys_module *module, struct lys_node *node, char *value, int type, int line)
{
    struct lys_restr *retval;

    switch (type) {
    case CONTAINER_KEYWORD:
        retval = &((struct lys_node_container *)node)->must[((struct lys_node_container *)node)->must_size++];
        break;
    case ANYXML_KEYWORD:
        retval = &((struct lys_node_anyxml *)node)->must[((struct lys_node_anyxml *)node)->must_size++];
        break;
    case LEAF_KEYWORD:
        retval = &((struct lys_node_leaf *)node)->must[((struct lys_node_leaf *)node)->must_size++];
        break;
    case LEAF_LIST_KEYWORD:
        retval = &((struct lys_node_leaflist *)node)->must[((struct lys_node_leaflist *)node)->must_size++];
        break;
    case LIST_KEYWORD:
        retval = &((struct lys_node_list *)node)->must[((struct lys_node_list *)node)->must_size++];
        break;
    }
    retval->expr = transform_schema2json(module, value, line);
    if (!retval->expr || lyxp_syntax_check(retval->expr, line)) {
        goto error;
    }
    free(value);
    return retval;

error:
    free(value);
    return NULL;
}

int
yang_read_message(struct lys_module *module,struct lys_restr *save,char *value, int type, int message, int line)
{
    int ret;
    char *exp;

    switch (type) {
    case MUST_KEYWORD:
        exp = "must";
        break;
    case LENGTH_KEYWORD:
        exp = "length";
        break;
    case PATTERN_KEYWORD:
        exp = "pattern";
        break;
    case RANGE_KEYWORD:
        exp = "range";
        break;
    }
    if (message==ERROR_APP_TAG_KEYWORD) {
        ret = yang_check_string(module, &save->eapptag, "error_app_tag", exp, value, line);
    } else {
        ret = yang_check_string(module, &save->emsg, "error_app_tag", exp, value, line);
    }
    return ret;
}

int
yang_read_presence(struct lys_module *module, struct lys_node_container *cont, char *value, int line)
{
    if (cont->presence) {
        LOGVAL(LYE_TOOMANY, line, LY_VLOG_LYS, cont, "presence", "container");
        free(value);
        return EXIT_FAILURE;
    } else {
        cont->presence = lydict_insert_zc(module->ctx, value);
        return EXIT_SUCCESS;
    }
}

int
yang_read_config(void *node, int value, int type, int line)
{
    int ret;

    switch (type) {
    case CONTAINER_KEYWORD:
        ret = yang_check_flags(&((struct lys_node_container *)node)->flags, LYS_CONFIG_MASK, "config", "container", value, line);
        break;
    case ANYXML_KEYWORD:
        ret = yang_check_flags(&((struct lys_node_anyxml *)node)->flags, LYS_CONFIG_MASK, "config", "anyxml", value, line);
        break;
    case CHOICE_KEYWORD:
        ret = yang_check_flags(&((struct lys_node_choice *)node)->flags, LYS_CONFIG_MASK, "config", "choice", value, line);
        break;
    case LEAF_KEYWORD:
        ret = yang_check_flags(&((struct lys_node_leaf *)node)->flags, LYS_CONFIG_MASK, "config", "leaf", value, line);
        break;
    case LEAF_LIST_KEYWORD:
        ret = yang_check_flags(&((struct lys_node_leaflist *)node)->flags, LYS_CONFIG_MASK, "config", "leaflist", value, line);
        break;
    case LIST_KEYWORD:
        ret = yang_check_flags(&((struct lys_node_list *)node)->flags, LYS_CONFIG_MASK, "config", "list", value, line);
        break;
    }
    return ret;
}

void *
yang_read_when(struct lys_module *module, struct lys_node *node, int type, char *value, int line)
{
    struct lys_when *retval;

    retval = calloc(1, sizeof *retval);
    if (!retval) {
        LOGMEM;
        free(value);
        return NULL;
    }
    retval->cond = transform_schema2json(module, value, line);
    if (!retval->cond || lyxp_syntax_check(retval->cond, line)) {
        goto error;
    }
    switch (type) {
    case CONTAINER_KEYWORD:
        if (((struct lys_node_container *)node)->when) {
            LOGVAL(LYE_TOOMANY, line, LY_VLOG_LYS, node, "when", "container");
            goto error;
        }
        ((struct lys_node_container *)node)->when = retval;
        break;
    case ANYXML_KEYWORD:
        if (((struct lys_node_anyxml *)node)->when) {
            LOGVAL(LYE_TOOMANY, line, LY_VLOG_LYS, node, "when", "anyxml");
            goto error;
        }
        ((struct lys_node_anyxml *)node)->when = retval;
        break;
    case CHOICE_KEYWORD:
        if (((struct lys_node_choice *)node)->when) {
            LOGVAL(LYE_TOOMANY, line, LY_VLOG_LYS, node, "when", "choice");
            goto error;
        }
        ((struct lys_node_choice *)node)->when = retval;
        break;
    case CASE_KEYWORD:
        if (((struct lys_node_case *)node)->when) {
            LOGVAL(LYE_TOOMANY, line, LY_VLOG_LYS, node, "when", "case");
            goto error;
        }
        ((struct lys_node_case *)node)->when = retval;
        break;
    case LEAF_KEYWORD:
        if (((struct lys_node_leaf *)node)->when) {
            LOGVAL(LYE_TOOMANY, line, LY_VLOG_LYS, node, "when", "leaf");
            goto error;
        }
        ((struct lys_node_leaf *)node)->when = retval;
        break;
    case LEAF_LIST_KEYWORD:
        if (((struct lys_node_leaflist *)node)->when) {
            LOGVAL(LYE_TOOMANY, line, LY_VLOG_LYS, node, "when", "leaflist");
            goto error;
        }
        ((struct lys_node_leaflist *)node)->when = retval;
        break;
    case LIST_KEYWORD:
        if (((struct lys_node_list *)node)->when) {
            LOGVAL(LYE_TOOMANY, line, LY_VLOG_LYS, node, "when", "list");
            goto error;
        }
        ((struct lys_node_list *)node)->when = retval;
        break;
    }
    free(value);
    return retval;

error:
    free(value);
    lys_when_free(module->ctx, retval);
    return NULL;
}

void *
yang_read_node(struct lys_module *module, struct lys_node *parent, char *value, int nodetype, int sizeof_struct)
{
    struct lys_node *node;

    node = calloc(1, sizeof_struct);
    if (!node) {
        LOGMEM;
        return NULL;
    }
    node->module = module;
    node->name = lydict_insert_zc(module->ctx, value);
    node->nodetype = nodetype;
    node->prev = node;

    /* insert the node into the schema tree */
    if (lys_node_addchild(parent, module->type ? ((struct lys_submodule *)module)->belongsto: module, node)) {
        lydict_remove(module->ctx, node->name);
        free(node);
        return NULL;
    }
    return node;
}

int
yang_read_mandatory(void *node, int value, int type, int line)
{
    int ret;

    switch (type) {
    case ANYXML_KEYWORD:
        ret = yang_check_flags(&((struct lys_node_anyxml *)node)->flags, LYS_MAND_MASK, "mandatory", "anyxml", value, line);
        break;
    case CHOICE_KEYWORD:
        ret = yang_check_flags(&((struct lys_node_choice *)node)->flags, LYS_MAND_MASK, "mandatory", "choice", value, line);
        break;
    case LEAF_KEYWORD:
        ret = yang_check_flags(&((struct lys_node_leaf *)node)->flags, LYS_MAND_MASK, "mandatory", "leaf", value, line);
        break;
    }
    return ret;
}

int
yang_read_default(struct lys_module *module, void *node, char *value, int type, int line)
{
    int ret;

    switch (type) {
    case LEAF_KEYWORD:
        ret = yang_check_string(module, &((struct lys_node_leaf *) node)->dflt, "default", "leaf", value, line);
        break;
    case TYPEDEF_KEYWORD:
        ret = yang_check_string(module, &((struct lys_tpdf *) node)->dflt, "default", "typedef", value, line);
        break;
    }
    return ret;
}

int
yang_read_units(struct lys_module *module, void *node, char *value, int type, int line)
{
    int ret;

    switch (type) {
    case LEAF_KEYWORD:
        ret = yang_check_string(module, &((struct lys_node_leaf *) node)->units, "units", "leaf", value, line);
        break;
    case LEAF_LIST_KEYWORD:
        ret = yang_check_string(module, &((struct lys_node_leaflist *) node)->units, "units", "leaflist", value, line);
        break;
    case TYPEDEF_KEYWORD:
        ret = yang_check_string(module, &((struct lys_tpdf *) node)->units, "units", "typedef", value, line);
        break;
    }
    return ret;
}

int
yang_read_key(struct lys_module *module, struct lys_node_list *list, struct unres_schema *unres, int line)
{
    char *exp, *value;

    exp = value = (char *) list->keys;
    while ((value = strpbrk(value, " \t\n"))) {
        list->keys_size++;
        while (isspace(*value)) {
            value++;
        }
    }
    list->keys_size++;
    list->keys = calloc(list->keys_size, sizeof *list->keys);
    if (!list->keys) {
        LOGMEM;
        goto error;
    }
    if (unres_schema_add_str(module, unres, list, UNRES_LIST_KEYS, exp, line) == -1) {
        goto error;
    }
    free(exp);
    return EXIT_SUCCESS;

error:
    free(exp);
    return EXIT_FAILURE;
}

int
yang_read_unique(struct lys_module *module, struct lys_node_list *list, struct unres_schema *unres)
{
    uint8_t k;
    int i, j;
    char *value, *vaux;
    struct lys_unique *unique;
    struct type_ident *ident;

    for(k=0; k<list->unique_size; k++) {
        unique = &list->unique[k];
        ident = (struct type_ident *)list->unique[k].expr;

        /* count the number of unique leafs in the value */
        vaux = value = ident->s;
        while ((vaux = strpbrk(vaux, " \t\n"))) {
           unique->expr_size++;
            while (isspace(*vaux)) {
                vaux++;
            }
        }
        unique->expr_size++;
        unique->expr = calloc(unique->expr_size, sizeof *unique->expr);
        if (!unique->expr) {
            LOGMEM;
            goto error;
        }

        for (i = 0; i < unique->expr_size; i++) {
            vaux = strpbrk(value, " \t\n");
            if (!vaux) {
                /* the last token, lydict_insert() will count its size on its own */
                vaux = value;
            }

            /* store token into unique structure */
            unique->expr[i] = lydict_insert(module->ctx, value, vaux - value);

            /* check that the expression does not repeat */
            for (j = 0; j < i; j++) {
                if (ly_strequal(unique->expr[j], unique->expr[i], 1)) {
                    LOGVAL(LYE_INARG, ident->line, LY_VLOG_LYS, list, unique->expr[i], "unique");
                    LOGVAL(LYE_SPEC, 0, 0, NULL, "The identifier is not unique");
                    goto error;
                }
            }

            /* try to resolve leaf */
            if (unres) {
                unres_schema_add_str(module, unres, (struct lys_node *)list, UNRES_LIST_UNIQ, unique->expr[i], ident->line);
            } else {
                if (resolve_unique((struct lys_node *)list, value, 0, ident->line)) {
                    goto error;
                }
            }

            /* move to next token */
            value = vaux;
            while(isspace(*value)) {
                value++;
            }
        }
        free(ident);
    }
    return EXIT_SUCCESS;

error:
    free(ident);
    return EXIT_FAILURE;
}

static int
yang_read_identyref(struct lys_module *module, struct lys_type *type, struct unres_schema *unres, int line)
{
    const char *value, *tmp;
    int rc, ret = EXIT_FAILURE;

    value = tmp = type->info.lref.path;
    /* store in the JSON format */
    value = transform_schema2json(module, value, line);
    if (!value) {
        goto end;
    }
    rc = unres_schema_add_str(module, unres, type, UNRES_TYPE_IDENTREF, value, line);
    lydict_remove(module->ctx, value);

    if (rc == -1) {
        goto end;
    }

    ret = EXIT_SUCCESS;

end:
    lydict_remove(module->ctx, tmp);
    return ret;
}

int
yang_check_type(struct lys_module *module, struct lys_node *parent, struct yang_type *typ, struct unres_schema *unres)
{
    int i, rc;
    int ret = -1;
    const char *name, *value;
    LY_DATA_TYPE base;
    struct yang_type *typ_tmp;

    base = typ->type->base;
    value = transform_schema2json(module, typ->name, typ->line);
    if (!value) {
        goto error;
    }

    i = parse_identifier(value);
    if (i < 1) {
        LOGVAL(LYE_INCHAR, typ->line, LY_VLOG_NONE, NULL, value[-i], &value[-i]);
        lydict_remove(module->ctx, value);
        goto error;
    }
    /* module name*/
    name = value;
    if (value[i]) {
        typ->type->module_name = lydict_insert(module->ctx, value, i);
        name += i;
        if ((name[0] != ':') || (parse_identifier(name + 1) < 1)) {
            LOGVAL(LYE_INCHAR, typ->line, LY_VLOG_NONE, NULL, name[0], name);
            lydict_remove(module->ctx, value);
            goto error;
        }
        ++name;
    }

    rc = resolve_superior_type(name, typ->type->module_name, module, parent, &typ->type->der);
    lydict_remove(module->ctx, value);
    if (rc == -1) {
        LOGVAL(LYE_INMOD, typ->line, LY_VLOG_NONE, NULL, typ->type->module_name);
        goto error;

    /* the type could not be resolved or it was resolved to an unresolved typedef*/
    } else if (rc == EXIT_FAILURE) {
        ret = EXIT_FAILURE;
        goto error;
    }
    typ->type->base = typ->type->der->type.base;
    if (base == 0) {
        base = typ->type->der->type.base;
    }
    switch (base) {
    case LY_TYPE_STRING:
        if (typ->type->base == LY_TYPE_BINARY) {
            if (typ->type->info.str.pat_count) {
                LOGVAL(LYE_SPEC, typ->line, LY_VLOG_NONE, NULL, "Binary type could not include pattern statement.");
                typ->type->base = base;
                goto error;
            }
            typ->type->info.binary.length = typ->type->info.str.length;
            if (typ->type->info.binary.length && lyp_check_length_range(typ->type->info.binary.length->expr, typ->type)) {
                LOGVAL(LYE_INARG, typ->line, LY_VLOG_NONE, NULL, typ->type->info.binary.length->expr, "length");
                goto error;
            }
        } else if (typ->type->base == LY_TYPE_STRING) {
            if (typ->type->info.str.length && lyp_check_length_range(typ->type->info.str.length->expr, typ->type)) {
                LOGVAL(LYE_INARG, typ->line, LY_VLOG_NONE, NULL, typ->type->info.str.length->expr, "length");
                goto error;
            }
        } else {
            LOGVAL(LYE_SPEC, typ->line, LY_VLOG_NONE, NULL, "Invalid restriction in type \"%s\".", parent->name);
            goto error;
        }
        break;
    case LY_TYPE_DEC64:
        if (typ->type->base == LY_TYPE_DEC64) {
            if (typ->type->info.dec64.range && lyp_check_length_range(typ->type->info.dec64.range->expr, typ->type)) {
                LOGVAL(LYE_INARG, typ->line, LY_VLOG_NONE, NULL, typ->type->info.dec64.range->expr, "range");
                goto error;
            }
            /* mandatory sub-statement(s) check */
            if (!typ->type->info.dec64.dig && !typ->type->der->type.der) {
                /* decimal64 type directly derived from built-in type requires fraction-digits */
                LOGVAL(LYE_MISSSTMT2, typ->line, LY_VLOG_NONE, NULL, "fraction-digits", "type");
                goto error;
            }
            if (typ->type->info.dec64.dig && typ->type->der->type.der) {
                /* type is not directly derived from buit-in type and fraction-digits statement is prohibited */
                LOGVAL(LYE_INSTMT, typ->line, LY_VLOG_NONE, NULL, "fraction-digits");
                goto error;
            }
        } else if (typ->type->base >= LY_TYPE_INT8 && typ->type->base <=LY_TYPE_UINT64) {
            if (typ->type->info.dec64.dig) {
                LOGVAL(LYE_SPEC, typ->line, LY_VLOG_NONE, NULL, "Numerical type could not include fraction statement.");
                typ->type->base = base;
                goto error;
            }
            typ->type->info.num.range = typ->type->info.dec64.range;
            if (typ->type->info.num.range && lyp_check_length_range(typ->type->info.num.range->expr, typ->type)) {
                LOGVAL(LYE_INARG, typ->line, LY_VLOG_NONE, NULL, typ->type->info.num.range->expr, "range");
                goto error;
            }
        } else {
            LOGVAL(LYE_SPEC, typ->line, LY_VLOG_NONE, NULL, "Invalid restriction in type \"%s\".", parent->name);
            goto error;
        }
        break;
    case LY_TYPE_ENUM:
        if (typ->type->base != LY_TYPE_ENUM) {
            LOGVAL(LYE_SPEC, typ->line, LY_VLOG_NONE, NULL, "Invalid restriction in type \"%s\".", parent->name);
            goto error;
        }
        if (!typ->type->der->type.der && !typ->type->info.enums.count) {
            /* type is derived directly from buit-in enumeartion type and enum statement is required */
            LOGVAL(LYE_MISSSTMT2, typ->line, LY_VLOG_NONE, NULL, "enum", "type");
            goto error;
        }
        if (typ->type->der->type.der && typ->type->info.enums.count) {
            /* type is not directly derived from buit-in enumeration type and enum statement is prohibited */
            LOGVAL(LYE_INSTMT, typ->line, LY_VLOG_NONE, NULL, "enum");
            goto error;
        }
        break;
    case LY_TYPE_LEAFREF:
        if (typ->type->base == LY_TYPE_IDENT && typ->flags & LYS_TYPE_BASE) {
            if (yang_read_identyref(module, typ->type, unres, typ->line)) {
                goto error;
            }
        } else if (typ->type->base == LY_TYPE_LEAFREF) {
            if (typ->type->info.lref.path && !typ->type->der->type.der) {
                value = typ->type->info.lref.path;
                /* store in the JSON format */
                typ->type->info.lref.path = transform_schema2json(module, value, typ->line);
                lydict_remove(module->ctx, value);
                if (!typ->type->info.lref.path) {
                    goto error;
                }
                if (unres_schema_add_node(module, unres, typ->type, UNRES_TYPE_LEAFREF, parent, typ->line) == -1) {
                    goto error;
                }
            } else if (!typ->type->info.lref.path && !typ->type->der->type.der) {
                LOGVAL(LYE_MISSSTMT2, typ->line, LY_VLOG_NONE, NULL, "path", "type");
                goto error;
            } else {
                LOGVAL(LYE_INSTMT, typ->line, LY_VLOG_NONE, NULL, "path");
                goto error;
            }
        } else {
            LOGVAL(LYE_SPEC, typ->line, LY_VLOG_NONE, NULL, "Invalid restriction in type \"%s\".", parent->name);
            goto error;
        }
        break;
    case LY_TYPE_IDENT:
        if (typ->type->der->type.der) {
            /* this is just a derived type with no base specified/required */
            break;
        } else {
            LOGVAL(LYE_MISSSTMT2, typ->line, LY_VLOG_NONE, NULL, "base", "type");
            goto error;
        }
        break;
    case LY_TYPE_UNION:
        if (typ->type->base != LY_TYPE_UNION) {
            typ->type->base = LY_TYPE_UNION;
            LOGVAL(LYE_SPEC, typ->line, LY_VLOG_NONE, NULL, "Invalid restriction in type \"%s\".", parent->name);
            goto error;
        }
        if (!typ->type->info.uni.types) {
            if (typ->type->der->type.der) {
                /* this is just a derived type with no additional type specified/required */
                break;
            }
            LOGVAL(LYE_MISSSTMT2, typ->line, LY_VLOG_NONE, NULL, "type", "(union) type");
            goto error;
        }
        for (i = 0; i < typ->type->info.uni.count; i++) {
            typ_tmp = (struct yang_type *)typ->type->info.uni.types[i].der;
            if (unres_schema_add_node(module, unres, &typ->type->info.uni.types[i], UNRES_TYPE_DER, parent, typ_tmp->line)) {
                goto error;
            }
            if (typ->type->info.uni.types[i].base == LY_TYPE_EMPTY) {
                LOGVAL(LYE_INARG, typ->line, LY_VLOG_NONE, NULL, "empty", typ->name);
                goto error;
            } else if (typ->type->info.uni.types[i].base == LY_TYPE_LEAFREF) {
                LOGVAL(LYE_INARG, typ->line, LY_VLOG_NONE, NULL, "leafref", typ->name);
                goto error;
            }
        }
        break;

    default:
        if (base >= LY_TYPE_BINARY && base <= LY_TYPE_UINT64) {
            if (typ->type->base != base) {
                LOGVAL(LYE_SPEC, typ->line, LY_VLOG_NONE, NULL, "Invalid restriction in type \"%s\".", parent->name);
                goto error;
            }
        } else {
            LOGINT;
            goto error;
        }
    }
    return EXIT_SUCCESS;

error:
    typ->type->base = base;
    if (typ->type->module_name) {
        lydict_remove(module->ctx, typ->type->module_name);
        typ->type->module_name = NULL;
    }
    return ret;
}

void *
yang_read_type(void *parent, char *value, int type, int line)
{
    struct yang_type *typ;

    typ = calloc(1, sizeof *typ);
    if (!typ) {
        LOGMEM;
        return NULL;
    }

    typ->flags = LY_YANG_STRUCTURE_FLAG;
    switch (type) {
    case LEAF_KEYWORD:
        ((struct lys_node_leaf *)parent)->type.der = (struct lys_tpdf *)typ;
        ((struct lys_node_leaf *)parent)->type.parent = (struct lys_tpdf *)parent;
        typ->type = &((struct lys_node_leaf *)parent)->type;
        break;
    case UNION_KEYWORD:
        ((struct lys_type *)parent)->der = (struct lys_tpdf *)typ;
        typ->type = (struct lys_type *)parent;
        break;
    case TYPEDEF_KEYWORD:
        ((struct lys_tpdf *)parent)->type.der = (struct lys_tpdf *)typ;
        typ->type = &((struct lys_tpdf *)parent)->type;
    }
    typ->name = value;
    typ->line = line;
    return typ;
}

void *
yang_read_length(struct lys_module *module, struct yang_type *typ, char *value, int line)
{
    struct lys_restr **length;

    if (typ->type->base == 0 || typ->type->base == LY_TYPE_STRING) {
        length = &typ->type->info.str.length;
        typ->type->base = LY_TYPE_STRING;
    } else if (typ->type->base == LY_TYPE_BINARY) {
        length = &typ->type->info.binary.length;
    } else {
        LOGVAL(LYE_SPEC, line, LY_VLOG_NONE, NULL, "Unexpected length statement.");
        goto error;
    }

    if (*length) {
        LOGVAL(LYE_TOOMANY, line, LY_VLOG_NONE, NULL, "length", "type");
    }
    *length = calloc(1, sizeof **length);
    if (!*length) {
        LOGMEM;
        goto error;
    }
    (*length)->expr = lydict_insert_zc(module->ctx, value);
    return *length;

error:
    free(value);
    return NULL;

}

void *
yang_read_pattern(struct lys_module *module, struct yang_type *typ, char *value, int line)
{
    pcre *precomp;
    int err_offset;
    const char *err_ptr;

    /* check that the regex is valid */
    precomp = pcre_compile(value, PCRE_NO_AUTO_CAPTURE, &err_ptr, &err_offset, NULL);
    if (!precomp) {
        LOGVAL(LYE_INREGEX, line, LY_VLOG_NONE, NULL, value, err_ptr);
        free(value);
        return NULL;
    }
    free(precomp);

    typ->type->info.str.patterns[typ->type->info.str.pat_count].expr = lydict_insert_zc(module->ctx, value);
    typ->type->info.str.pat_count++;
    return &typ->type->info.str.patterns[typ->type->info.str.pat_count-1];
}

void *
yang_read_range(struct  lys_module *module, struct yang_type *typ, char *value, int line)
{
    if (typ->type->base != 0 && typ->type->base != LY_TYPE_DEC64) {
        LOGVAL(LYE_SPEC, line, LY_VLOG_NONE, NULL, "Unexpected range statement.");
        goto error;
    }
    typ->type->base = LY_TYPE_DEC64;
    if (typ->type->info.dec64.range) {
        LOGVAL(LYE_TOOMANY, line, LY_VLOG_NONE, NULL, "range", "type");
        goto error;
    }
    typ->type->info.dec64.range = calloc(1, sizeof *typ->type->info.dec64.range);
    if (!typ->type->info.dec64.range) {
        LOGMEM;
        goto error;
    }
    typ->type->info.dec64.range->expr = lydict_insert_zc(module->ctx, value);
    return typ->type->info.dec64.range;

error:
    free(value);
    return NULL;
}

int
yang_read_fraction(struct yang_type *typ, uint32_t value, int line)
{
    if (typ->type->base == 0 || typ->type->base == LY_TYPE_DEC64) {
        typ->type->base = LY_TYPE_DEC64;
    } else {
        LOGVAL(LYE_SPEC, line, LY_VLOG_NONE, NULL, "Unexpected fraction-digits statement.");
        goto error;
    }
    if (typ->type->info.dec64.dig) {
        LOGVAL(LYE_TOOMANY, line, LY_VLOG_NONE, NULL, "fraction-digits", "type");
        goto error;
    }
    /* range check */
    if (value < 1 || value > 18) {
        LOGVAL(LYE_SPEC, line, LY_VLOG_NONE, NULL, "Invalid value \"%d\" of \"%s\".", value, "fraction-digits");
        goto error;
    }
    typ->type->info.dec64.dig = value;
    return EXIT_SUCCESS;

error:
    return EXIT_FAILURE;
}

void *
yang_read_enum(struct lys_module *module, struct yang_type *typ, char *value, int line)
{
    struct lys_type_enum *enm;
    int i;

    enm = &typ->type->info.enums.enm[typ->type->info.enums.count];
    enm->name = lydict_insert_zc(module->ctx, value);

    /* the assigned name MUST NOT have any leading or trailing whitespace characters */
    if (isspace(enm->name[0]) || isspace(enm->name[strlen(enm->name) - 1])) {
        LOGVAL(LYE_ENUM_WS, line, LY_VLOG_NONE, NULL, enm->name);
        goto error;
    }

    /* check the name uniqueness */
    for (i = 0; i < typ->type->info.enums.count; i++) {
        if (!strcmp(typ->type->info.enums.enm[i].name, typ->type->info.enums.enm[typ->type->info.enums.count].name)) {
            LOGVAL(LYE_ENUM_DUPNAME, line, LY_VLOG_NONE, NULL, typ->type->info.enums.enm[i].name);
            goto error;
        }
    }

    typ->type->info.enums.count++;
    return enm;

error:
    typ->type->info.enums.count++;
    return NULL;
}

int
yang_check_enum(struct yang_type *typ, struct lys_type_enum *enm, int64_t *value, int assign, int line)
{
    int i, j;

    if (!assign) {
        /* assign value automatically */
        if (*value > INT32_MAX) {
            LOGVAL(LYE_INARG, line, LY_VLOG_NONE, NULL, "2147483648", "enum/value");
            goto error;
        }
        enm->value = *value;
        enm->flags |= LYS_AUTOASSIGNED;
        (*value)++;
    }

    /* check that the value is unique */
    j = typ->type->info.enums.count-1;
    for (i = 0; i < j; i++) {
        if (typ->type->info.enums.enm[i].value == typ->type->info.enums.enm[j].value) {
            LOGVAL(LYE_ENUM_DUPVAL, line, LY_VLOG_NONE, NULL,
                   typ->type->info.enums.enm[j].value, typ->type->info.enums.enm[j].name);
            goto error;
        }
    }

    return EXIT_SUCCESS;

error:
    return EXIT_FAILURE;
}

void *
yang_read_bit(struct lys_module *module, struct yang_type *typ, char *value, int line)
{
    int i;
    struct lys_type_bit *bit;

    bit = &typ->type->info.bits.bit[typ->type->info.bits.count];
    if (lyp_check_identifier(value, LY_IDENT_SIMPLE, line, NULL, NULL)) {
        LOGVAL(LYE_PATH, 0, LY_VLOG_NONE, NULL);
        free(value);
        goto error;
    }
    bit->name = lydict_insert_zc(module->ctx, value);

    /* check the name uniqueness */
    for (i = 0; i < typ->type->info.bits.count; i++) {
        if (!strcmp(typ->type->info.bits.bit[i].name, bit->name)) {
            LOGVAL(LYE_BITS_DUPNAME, line, LY_VLOG_NONE, NULL, bit->name);
            typ->type->info.bits.count++;
            goto error;
        }
    }
    typ->type->info.bits.count++;
    return bit;

error:
    return NULL;
}

int
yang_check_bit(struct yang_type *typ, struct lys_type_bit *bit, int64_t *value, int assign, int line)
{
    int i,j;
    struct lys_type_bit bit_tmp;

    if (!assign) {
        /* assign value automatically */
        if (*value > UINT32_MAX) {
            LOGVAL(LYE_INARG, line, LY_VLOG_NONE, NULL, "4294967295", "bit/position");
            goto error;
        }
        bit->pos = (uint32_t)*value;
        bit->flags |= LYS_AUTOASSIGNED;
        (*value)++;
    }

    j = typ->type->info.bits.count - 1;
    /* check that the value is unique */
    for (i = 0; i < j; i++) {
        if (typ->type->info.bits.bit[i].pos == bit->pos) {
            LOGVAL(LYE_BITS_DUPVAL, line, LY_VLOG_NONE, NULL, bit->pos, bit->name);
            goto error;
        }
    }

    /* keep them ordered by position */
    while (j && typ->type->info.bits.bit[j - 1].pos > typ->type->info.bits.bit[j].pos) {
        /* switch them */
        memcpy(&bit_tmp, &typ->type->info.bits.bit[j], sizeof bit_tmp);
        memcpy(&typ->type->info.bits.bit[j], &typ->type->info.bits.bit[j - 1], sizeof bit_tmp);
        memcpy(&typ->type->info.bits.bit[j - 1], &bit_tmp, sizeof bit_tmp);
        j--;
    }

    return EXIT_SUCCESS;

error:
    return EXIT_FAILURE;
}

void *
yang_read_typedef(struct lys_module *module, struct lys_node *parent, char *value, int line)
{
    struct lys_tpdf *ret;

    if (lyp_check_identifier(value, LY_IDENT_TYPE, line, module, parent)) {
        free(value);
        return NULL;
    }
    if (!parent) {
        ret = &module->tpdf[module->tpdf_size];
        ret->type.parent = NULL;
        module->tpdf_size++;
    }

    ret->name = lydict_insert_zc(module->ctx, value);
    ret->module = module;
    return ret;
}