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Diffstat (limited to 'src/schema_features.c')
-rw-r--r-- | src/schema_features.c | 714 |
1 files changed, 714 insertions, 0 deletions
diff --git a/src/schema_features.c b/src/schema_features.c new file mode 100644 index 0000000..dca998e --- /dev/null +++ b/src/schema_features.c @@ -0,0 +1,714 @@ +/** + * @file schema_features.c + * @author Radek Krejci <rkrejci@cesnet.cz> + * @brief Schema feature handling + * + * Copyright (c) 2015 - 2020 CESNET, z.s.p.o. + * + * This source code is licensed under BSD 3-Clause License (the "License"). + * You may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * https://opensource.org/licenses/BSD-3-Clause + */ + +#define _GNU_SOURCE + +#include "schema_features.h" + +#include <assert.h> +#include <ctype.h> +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include "common.h" +#include "log.h" +#include "set.h" +#include "tree.h" +#include "tree_edit.h" +#include "tree_schema.h" +#include "tree_schema_internal.h" + +#define IFF_RECORDS_IN_BYTE 4 +#define IFF_RECORD_BITS 2 +#define IFF_RECORD_MASK 0x3 + +uint8_t +lysc_iff_getop(uint8_t *list, size_t pos) +{ + uint8_t *item; + uint8_t mask = IFF_RECORD_MASK, result; + + item = &list[pos / IFF_RECORDS_IN_BYTE]; + result = (*item) & (mask << IFF_RECORD_BITS * (pos % IFF_RECORDS_IN_BYTE)); + return result >> IFF_RECORD_BITS * (pos % IFF_RECORDS_IN_BYTE); +} + +static LY_ERR +lysc_iffeature_value_(const struct lysc_iffeature *iff, size_t *index_e, size_t *index_f) +{ + uint8_t op; + LY_ERR a, b; + + op = lysc_iff_getop(iff->expr, *index_e); + (*index_e)++; + + switch (op) { + case LYS_IFF_F: + /* resolve feature */ + return (iff->features[(*index_f)++]->flags & LYS_FENABLED) ? LY_SUCCESS : LY_ENOT; + case LYS_IFF_NOT: + /* invert result */ + return lysc_iffeature_value_(iff, index_e, index_f) == LY_SUCCESS ? LY_ENOT : LY_SUCCESS; + case LYS_IFF_AND: + case LYS_IFF_OR: + a = lysc_iffeature_value_(iff, index_e, index_f); + b = lysc_iffeature_value_(iff, index_e, index_f); + if (op == LYS_IFF_AND) { + if ((a == LY_SUCCESS) && (b == LY_SUCCESS)) { + return LY_SUCCESS; + } else { + return LY_ENOT; + } + } else { /* LYS_IFF_OR */ + if ((a == LY_SUCCESS) || (b == LY_SUCCESS)) { + return LY_SUCCESS; + } else { + return LY_ENOT; + } + } + } + + return LY_ENOT; +} + +LIBYANG_API_DEF LY_ERR +lysc_iffeature_value(const struct lysc_iffeature *iff) +{ + size_t index_e = 0, index_f = 0; + + LY_CHECK_ARG_RET(NULL, iff, LY_EINVAL); + + if (iff->expr) { + return lysc_iffeature_value_(iff, &index_e, &index_f); + } + return LY_ENOT; +} + +LIBYANG_API_DEF LY_ERR +lys_identity_iffeature_value(const struct lysc_ident *ident) +{ + LY_ARRAY_COUNT_TYPE u, v; + ly_bool enabled; + const struct lysp_ident *idents_p, *found_ident = NULL; + struct lysp_include *includes; + + assert(ident); + + /* Search parsed identity in the module. */ + idents_p = ident->module->parsed->identities; + LY_ARRAY_FOR(idents_p, u) { + if (idents_p[u].name == ident->name) { + found_ident = &idents_p[u]; + break; + } + } + + if (!found_ident) { + /* It is not in the module, so it must be in some submodule. */ + includes = ident->module->parsed->includes; + LY_ARRAY_FOR(includes, u) { + idents_p = includes[u].submodule->identities; + LY_ARRAY_FOR(idents_p, v) { + if (idents_p[v].name == ident->name) { + found_ident = &idents_p[v]; + break; + } + } + } + } + + assert(found_ident); + + /* Evaluate its if-feature. */ + LY_CHECK_RET(lys_eval_iffeatures(ident->module->ctx, found_ident->iffeatures, &enabled)); + if (!enabled) { + return LY_ENOT; + } + + return LY_SUCCESS; +} + +LIBYANG_API_DEF struct lysp_feature * +lysp_feature_next(const struct lysp_feature *last, const struct lysp_module *pmod, uint32_t *idx) +{ + struct lysp_feature *features; + + if (!*idx) { + /* module features */ + features = pmod->features; + } else if ((*idx - 1) < LY_ARRAY_COUNT(pmod->includes)) { + /* submodule features */ + features = pmod->includes[*idx - 1].submodule->features; + } else { + /* no more features */ + return NULL; + } + + /* get the next feature */ + if (features && (!last || (&features[LY_ARRAY_COUNT(features) - 1] != last))) { + return !last ? &features[0] : (struct lysp_feature *)last + 1; + } + + /* no more features in current (sub)module */ + ++(*idx); + return lysp_feature_next(NULL, pmod, idx); +} + +/** + * @brief Find a feature of the given name and referenced in the given module. + * + * @param[in] pmod Module where the feature was referenced (used to resolve prefix of the feature). + * @param[in] name Name of the feature including possible prefix. + * @param[in] len Length of the string representing the feature identifier in the name variable (mandatory!). + * @param[in] prefixed Whether the feature name can be prefixed. + * @return Pointer to the feature structure if found, NULL otherwise. + */ +static struct lysp_feature * +lysp_feature_find(const struct lysp_module *pmod, const char *name, size_t len, ly_bool prefixed) +{ + const struct lys_module *mod; + const char *ptr; + struct lysp_feature *f = NULL; + uint32_t idx = 0; + + assert(pmod); + + if (prefixed && (ptr = ly_strnchr(name, ':', len))) { + /* we have a prefixed feature */ + mod = ly_resolve_prefix(pmod->mod->ctx, name, ptr - name, LY_VALUE_SCHEMA, (void *)pmod); + LY_CHECK_RET(!mod, NULL); + + pmod = mod->parsed; + len = len - (ptr - name) - 1; + name = ptr + 1; + } + + /* feature without prefix, look in main module and all submodules */ + if (pmod->is_submod) { + pmod = pmod->mod->parsed; + } + + /* we have the correct module, get the feature */ + while ((f = lysp_feature_next(f, pmod, &idx))) { + if (!ly_strncmp(f->name, name, len)) { + return f; + } + } + + return NULL; +} + +LIBYANG_API_DEF LY_ERR +lys_feature_value(const struct lys_module *module, const char *feature) +{ + const struct lysp_feature *f; + + LY_CHECK_ARG_RET(NULL, module, module->parsed, feature, LY_EINVAL); + + /* search for the specified feature */ + f = lysp_feature_find(module->parsed, feature, strlen(feature), 0); + LY_CHECK_RET(!f, LY_ENOTFOUND); + + /* feature disabled */ + if (!(f->flags & LYS_FENABLED)) { + return LY_ENOT; + } + + /* feature enabled */ + return LY_SUCCESS; +} + +/** + * @brief Stack for processing if-feature expressions. + */ +struct iff_stack { + size_t size; /**< number of items in the stack */ + size_t index; /**< first empty item */ + uint8_t *stack; /**< stack - array of @ref ifftokens to create the if-feature expression in prefix format */ +}; +#define IFF_STACK_SIZE_STEP 4 + +/** + * @brief Add @ref ifftokens into the stack. + * @param[in] stack The if-feature stack to use. + * @param[in] value One of the @ref ifftokens to store in the stack. + * @return LY_EMEM in case of memory allocation error + * @return LY_ESUCCESS if the value successfully stored. + */ +static LY_ERR +iff_stack_push(struct iff_stack *stack, uint8_t value) +{ + if (stack->index == stack->size) { + stack->size += IFF_STACK_SIZE_STEP; + stack->stack = ly_realloc(stack->stack, stack->size * sizeof *stack->stack); + LY_CHECK_ERR_RET(!stack->stack, LOGMEM(NULL); stack->size = 0, LY_EMEM); + } + stack->stack[stack->index++] = value; + return LY_SUCCESS; +} + +/** + * @brief Get (and remove) the last item form the stack. + * @param[in] stack The if-feature stack to use. + * @return The value from the top of the stack. + */ +static uint8_t +iff_stack_pop(struct iff_stack *stack) +{ + assert(stack && stack->index); + + stack->index--; + return stack->stack[stack->index]; +} + +/** + * @brief Clean up the stack. + * @param[in] stack The if-feature stack to use. + */ +static void +iff_stack_clean(struct iff_stack *stack) +{ + stack->size = 0; + free(stack->stack); +} + +/** + * @brief Store the @ref ifftokens (@p op) on the given position in the 2bits array + * (libyang format of the if-feature expression). + * @param[in,out] list The 2bits array to modify. + * @param[in] op The operand (@ref ifftokens) to store. + * @param[in] pos Position (0-based) where to store the given @p op. + */ +static void +iff_setop(uint8_t *list, uint8_t op, size_t pos) +{ + uint8_t *item; + uint8_t mask = IFF_RECORD_MASK; + + assert(op <= IFF_RECORD_MASK); /* max 2 bits */ + + item = &list[pos / IFF_RECORDS_IN_BYTE]; + mask = mask << IFF_RECORD_BITS * (pos % IFF_RECORDS_IN_BYTE); + *item = (*item) & ~mask; + *item = (*item) | (op << IFF_RECORD_BITS * (pos % IFF_RECORDS_IN_BYTE)); +} + +#define LYS_IFF_LP 0x04 /**< Additional, temporary, value of @ref ifftokens: ( */ +#define LYS_IFF_RP 0x08 /**< Additional, temporary, value of @ref ifftokens: ) */ + +static LY_ERR +lys_compile_iffeature(const struct ly_ctx *ctx, const struct lysp_qname *qname, struct lysc_iffeature *iff) +{ + LY_ERR rc = LY_SUCCESS; + const char *c = qname->str; + int64_t i, j; + int8_t op_len, last_not = 0, checkversion = 0; + LY_ARRAY_COUNT_TYPE f_size = 0, expr_size = 0, f_exp = 1; + uint8_t op; + struct iff_stack stack = {0, 0, NULL}; + struct lysp_feature *f; + + assert(c); + + /* pre-parse the expression to get sizes for arrays, also do some syntax checks of the expression */ + for (i = j = 0; c[i]; i++) { + if (c[i] == '(') { + j++; + checkversion = 1; + continue; + } else if (c[i] == ')') { + j--; + continue; + } else if (isspace(c[i])) { + checkversion = 1; + continue; + } + + if (!strncmp(&c[i], "not", op_len = ly_strlen_const("not")) || + !strncmp(&c[i], "and", op_len = ly_strlen_const("and")) || + !strncmp(&c[i], "or", op_len = ly_strlen_const("or"))) { + uint64_t spaces; + + for (spaces = 0; c[i + op_len + spaces] && isspace(c[i + op_len + spaces]); spaces++) {} + if (c[i + op_len + spaces] == '\0') { + LOGVAL(ctx, LYVE_SYNTAX_YANG, "Invalid value \"%s\" of if-feature - unexpected end of expression.", qname->str); + return LY_EVALID; + } else if (!isspace(c[i + op_len])) { + /* feature name starting with the not/and/or */ + last_not = 0; + f_size++; + } else if (c[i] == 'n') { /* not operation */ + if (last_not) { + /* double not */ + expr_size = expr_size - 2; + last_not = 0; + } else { + last_not = 1; + } + } else { /* and, or */ + if (f_exp != f_size) { + LOGVAL(ctx, LYVE_SYNTAX_YANG, + "Invalid value \"%s\" of if-feature - missing feature/expression before \"%.*s\" operation.", + qname->str, op_len, &c[i]); + return LY_EVALID; + } + f_exp++; + + /* not a not operation */ + last_not = 0; + } + i += op_len; + } else { + f_size++; + last_not = 0; + } + expr_size++; + + while (!isspace(c[i])) { + if (!c[i] || (c[i] == ')') || (c[i] == '(')) { + i--; + break; + } + i++; + } + } + if (j) { + /* not matching count of ( and ) */ + LOGVAL(ctx, LYVE_SYNTAX_YANG, "Invalid value \"%s\" of if-feature - non-matching opening and closing parentheses.", + qname->str); + return LY_EVALID; + } + if (f_exp != f_size) { + /* features do not match the needed arguments for the logical operations */ + LOGVAL(ctx, LYVE_SYNTAX_YANG, "Invalid value \"%s\" of if-feature - number of features in expression does not match " + "the required number of operands for the operations.", qname->str); + return LY_EVALID; + } + + if (checkversion || (expr_size > 1)) { + /* check that we have 1.1 module */ + if (qname->mod->version != LYS_VERSION_1_1) { + LOGVAL(ctx, LYVE_SYNTAX_YANG, "Invalid value \"%s\" of if-feature - YANG 1.1 expression in YANG 1.0 module.", + qname->str); + return LY_EVALID; + } + } + + /* allocate the memory */ + LY_ARRAY_CREATE_RET(ctx, iff->features, f_size, LY_EMEM); + iff->expr = calloc((j = (expr_size / IFF_RECORDS_IN_BYTE) + ((expr_size % IFF_RECORDS_IN_BYTE) ? 1 : 0)), sizeof *iff->expr); + stack.stack = malloc(expr_size * sizeof *stack.stack); + LY_CHECK_ERR_GOTO(!stack.stack || !iff->expr, LOGMEM(ctx); rc = LY_EMEM, error); + + stack.size = expr_size; + f_size--; expr_size--; /* used as indexes from now */ + + for (i--; i >= 0; i--) { + if (c[i] == ')') { + /* push it on stack */ + iff_stack_push(&stack, LYS_IFF_RP); + continue; + } else if (c[i] == '(') { + /* pop from the stack into result all operators until ) */ + while ((op = iff_stack_pop(&stack)) != LYS_IFF_RP) { + iff_setop(iff->expr, op, expr_size--); + } + continue; + } else if (isspace(c[i])) { + continue; + } + + /* end of operator or operand -> find beginning and get what is it */ + j = i + 1; + while (i >= 0 && !isspace(c[i]) && c[i] != '(') { + i--; + } + i++; /* go back by one step */ + + if (!strncmp(&c[i], "not", ly_strlen_const("not")) && isspace(c[i + ly_strlen_const("not")])) { + if (stack.index && (stack.stack[stack.index - 1] == LYS_IFF_NOT)) { + /* double not */ + iff_stack_pop(&stack); + } else { + /* not has the highest priority, so do not pop from the stack + * as in case of AND and OR */ + iff_stack_push(&stack, LYS_IFF_NOT); + } + } else if (!strncmp(&c[i], "and", ly_strlen_const("and")) && isspace(c[i + ly_strlen_const("and")])) { + /* as for OR - pop from the stack all operators with the same or higher + * priority and store them to the result, then push the AND to the stack */ + while (stack.index && stack.stack[stack.index - 1] <= LYS_IFF_AND) { + op = iff_stack_pop(&stack); + iff_setop(iff->expr, op, expr_size--); + } + iff_stack_push(&stack, LYS_IFF_AND); + } else if (!strncmp(&c[i], "or", 2) && isspace(c[i + 2])) { + while (stack.index && stack.stack[stack.index - 1] <= LYS_IFF_OR) { + op = iff_stack_pop(&stack); + iff_setop(iff->expr, op, expr_size--); + } + iff_stack_push(&stack, LYS_IFF_OR); + } else { + /* feature name, length is j - i */ + + /* add it to the expression */ + iff_setop(iff->expr, LYS_IFF_F, expr_size--); + + /* now get the link to the feature definition */ + f = lysp_feature_find(qname->mod, &c[i], j - i, 1); + if (!f) { + LOGVAL(ctx, LYVE_SYNTAX_YANG, "Invalid value \"%s\" of if-feature - unable to find feature \"%.*s\".", + qname->str, (int)(j - i), &c[i]); + rc = LY_EVALID; + goto error; + } + iff->features[f_size] = f; + LY_ARRAY_INCREMENT(iff->features); + f_size--; + } + } + while (stack.index) { + op = iff_stack_pop(&stack); + iff_setop(iff->expr, op, expr_size--); + } + + if (++expr_size || ++f_size) { + /* not all expected operators and operands found */ + LOGVAL(ctx, LYVE_SYNTAX_YANG, "Invalid value \"%s\" of if-feature - processing error.", qname->str); + rc = LY_EINT; + } else { + rc = LY_SUCCESS; + } + +error: + /* cleanup */ + iff_stack_clean(&stack); + + return rc; +} + +LY_ERR +lys_eval_iffeatures(const struct ly_ctx *ctx, const struct lysp_qname *iffeatures, ly_bool *enabled) +{ + LY_ERR ret; + LY_ARRAY_COUNT_TYPE u; + struct lysc_iffeature iff; + struct lysf_ctx fctx = {.ctx = (struct ly_ctx *)ctx}; + + /* enabled by default */ + *enabled = 1; + + if (!iffeatures) { + return LY_SUCCESS; + } + + /* evaluate all if-feature conditions or until an unsatisfied one is found */ + LY_ARRAY_FOR(iffeatures, u) { + memset(&iff, 0, sizeof iff); + LY_CHECK_RET(lys_compile_iffeature(ctx, &iffeatures[u], &iff)); + + ret = lysc_iffeature_value(&iff); + lysc_iffeature_free(&fctx, &iff); + if (ret == LY_ENOT) { + *enabled = 0; + break; + } else if (ret) { + return ret; + } + } + + return LY_SUCCESS; +} + +LY_ERR +lys_check_features(const struct lysp_module *pmod) +{ + LY_ERR r; + uint32_t i = 0; + struct lysp_feature *f = NULL; + + while ((f = lysp_feature_next(f, pmod, &i))) { + if (!(f->flags & LYS_FENABLED) || !f->iffeatures) { + /* disabled feature or no if-features to check */ + continue; + } + + assert(f->iffeatures_c); + r = lysc_iffeature_value(f->iffeatures_c); + if (r == LY_ENOT) { + LOGERR(pmod->mod->ctx, LY_EDENIED, "Feature \"%s\" cannot be enabled because its \"if-feature\" is not satisfied.", + f->name); + return LY_EDENIED; + } else if (r) { + return r; + } /* else if-feature satisfied */ + } + + return LY_SUCCESS; +} + +LY_ERR +lys_set_features(struct lysp_module *pmod, const char **features) +{ + uint32_t i = 0, j; + struct lysp_feature *f = 0; + ly_bool change = 0; + + if (!features) { + /* do not touch the features */ + + } else if (!features[0]) { + /* disable all the features */ + while ((f = lysp_feature_next(f, pmod, &i))) { + if (f->flags & LYS_FENABLED) { + f->flags &= ~LYS_FENABLED; + change = 1; + } + } + } else if (!strcmp(features[0], "*")) { + /* enable all the features */ + while ((f = lysp_feature_next(f, pmod, &i))) { + if (!(f->flags & LYS_FENABLED)) { + f->flags |= LYS_FENABLED; + change = 1; + } + } + } else { + /* check that all the features exist */ + for (j = 0; features[j]; ++j) { + if (!lysp_feature_find(pmod, features[j], strlen(features[j]), 0)) { + LOGERR(pmod->mod->ctx, LY_EINVAL, "Feature \"%s\" not found in module \"%s\".", features[j], pmod->mod->name); + return LY_EINVAL; + } + } + + /* enable specific features, disable the rest */ + while ((f = lysp_feature_next(f, pmod, &i))) { + for (j = 0; features[j]; ++j) { + if (!strcmp(f->name, features[j])) { + break; + } + } + + if (features[j] && !(f->flags & LYS_FENABLED)) { + /* enable */ + f->flags |= LYS_FENABLED; + change = 1; + } else if (!features[j] && (f->flags & LYS_FENABLED)) { + /* disable */ + f->flags &= ~LYS_FENABLED; + change = 1; + } + } + } + + if (!change) { + /* features already set correctly */ + return LY_EEXIST; + } + + return LY_SUCCESS; +} + +/** + * @brief Check circular dependency of features - feature MUST NOT reference itself (via their if-feature statement). + * + * The function works in the same way as lys_compile_identity_circular_check() with different structures and error messages. + * + * @param[in] ctx Compile context for logging. + * @param[in] feature The feature referenced in if-feature statement (its depfeatures list is being extended by the feature + * being currently processed). + * @param[in] depfeatures The list of depending features of the feature being currently processed (not the one provided as @p feature) + * @return LY_SUCCESS if everything is ok. + * @return LY_EVALID if the feature references indirectly itself. + */ +static LY_ERR +lys_compile_feature_circular_check(const struct ly_ctx *ctx, struct lysp_feature *feature, struct lysp_feature **depfeatures) +{ + LY_ERR ret = LY_SUCCESS; + LY_ARRAY_COUNT_TYPE u, v; + struct ly_set recursion = {0}; + struct lysp_feature *drv; + + if (!depfeatures) { + return LY_SUCCESS; + } + + for (u = 0; u < LY_ARRAY_COUNT(depfeatures); ++u) { + if (feature == depfeatures[u]) { + LOGVAL(ctx, LYVE_REFERENCE, "Feature \"%s\" is indirectly referenced from itself.", feature->name); + ret = LY_EVALID; + goto cleanup; + } + ret = ly_set_add(&recursion, depfeatures[u], 0, NULL); + LY_CHECK_GOTO(ret, cleanup); + } + + for (v = 0; v < recursion.count; ++v) { + drv = recursion.objs[v]; + for (u = 0; u < LY_ARRAY_COUNT(drv->depfeatures); ++u) { + if (feature == drv->depfeatures[u]) { + LOGVAL(ctx, LYVE_REFERENCE, "Feature \"%s\" is indirectly referenced from itself.", feature->name); + ret = LY_EVALID; + goto cleanup; + } + ly_set_add(&recursion, drv->depfeatures[u], 0, NULL); + LY_CHECK_GOTO(ret, cleanup); + } + } + +cleanup: + ly_set_erase(&recursion, NULL); + return ret; +} + +LY_ERR +lys_compile_feature_iffeatures(struct lysp_module *pmod) +{ + LY_ARRAY_COUNT_TYPE u, v; + struct lysp_feature *f = NULL, **df; + uint32_t idx = 0; + + while ((f = lysp_feature_next(f, pmod, &idx))) { + if (!f->iffeatures) { + continue; + } + + /* compile if-features */ + LY_ARRAY_CREATE_RET(pmod->mod->ctx, f->iffeatures_c, LY_ARRAY_COUNT(f->iffeatures), LY_EMEM); + LY_ARRAY_FOR(f->iffeatures, u) { + LY_ARRAY_INCREMENT(f->iffeatures_c); + LY_CHECK_RET(lys_compile_iffeature(pmod->mod->ctx, &(f->iffeatures)[u], &(f->iffeatures_c)[u])); + } + LY_ARRAY_FOR(f->iffeatures_c, u) { + LY_ARRAY_FOR(f->iffeatures_c[u].features, v) { + /* check for circular dependency - direct reference first,... */ + if (f == f->iffeatures_c[u].features[v]) { + LOGVAL(pmod->mod->ctx, LYVE_REFERENCE, "Feature \"%s\" is referenced from itself.", f->name); + return LY_EVALID; + } + /* ... and indirect circular reference */ + LY_CHECK_RET(lys_compile_feature_circular_check(pmod->mod->ctx, f->iffeatures_c[u].features[v], f->depfeatures)); + + /* add itself into the dependants list */ + LY_ARRAY_NEW_RET(pmod->mod->ctx, f->iffeatures_c[u].features[v]->depfeatures, df, LY_EMEM); + *df = f; + } + } + } + + return LY_SUCCESS; +} |