linux/security/ipe/policy_parser.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved.
 */

#include <linux/err.h>
#include <linux/slab.h>
#include <linux/parser.h>
#include <linux/types.h>
#include <linux/ctype.h>

#include "policy.h"
#include "policy_parser.h"
#include "digest.h"

#define START_COMMENT …
#define IPE_POLICY_DELIM …
#define IPE_LINE_DELIM …

/**
 * new_parsed_policy() - Allocate and initialize a parsed policy.
 *
 * Return:
 * * a pointer to the ipe_parsed_policy structure	- Success
 * * %-ENOMEM						- Out of memory (OOM)
 */
static struct ipe_parsed_policy *new_parsed_policy(void)
{ … }

/**
 * remove_comment() - Truncate all chars following START_COMMENT in a string.
 *
 * @line: Supplies a policy line string for preprocessing.
 */
static void remove_comment(char *line)
{ … }

/**
 * remove_trailing_spaces() - Truncate all trailing spaces in a string.
 *
 * @line: Supplies a policy line string for preprocessing.
 *
 * Return: The length of truncated string.
 */
static size_t remove_trailing_spaces(char *line)
{ … }

/**
 * parse_version() - Parse policy version.
 * @ver: Supplies a version string to be parsed.
 * @p: Supplies the partial parsed policy.
 *
 * Return:
 * * %0		- Success
 * * %-EBADMSG	- Version string is invalid
 * * %-ERANGE	- Version number overflow
 * * %-EINVAL	- Parsing error
 */
static int parse_version(char *ver, struct ipe_parsed_policy *p)
{ … }

enum header_opt { … };

static const match_table_t header_tokens = …;

/**
 * parse_header() - Parse policy header information.
 * @line: Supplies header line to be parsed.
 * @p: Supplies the partial parsed policy.
 *
 * Return:
 * * %0		- Success
 * * %-EBADMSG	- Header string is invalid
 * * %-ENOMEM	- Out of memory (OOM)
 * * %-ERANGE	- Version number overflow
 * * %-EINVAL	- Version parsing error
 */
static int parse_header(char *line, struct ipe_parsed_policy *p)
{ … }

/**
 * token_default() - Determine if the given token is "DEFAULT".
 * @token: Supplies the token string to be compared.
 *
 * Return:
 * * %false	- The token is not "DEFAULT"
 * * %true	- The token is "DEFAULT"
 */
static bool token_default(char *token)
{ … }

/**
 * free_rule() - Free the supplied ipe_rule struct.
 * @r: Supplies the ipe_rule struct to be freed.
 *
 * Free a ipe_rule struct @r. Note @r must be removed from any lists before
 * calling this function.
 */
static void free_rule(struct ipe_rule *r)
{ … }

static const match_table_t operation_tokens = …;

/**
 * parse_operation() - Parse the operation type given a token string.
 * @t: Supplies the token string to be parsed.
 *
 * Return: The parsed operation type.
 */
static enum ipe_op_type parse_operation(char *t)
{ … }

static const match_table_t action_tokens = …;

/**
 * parse_action() - Parse the action type given a token string.
 * @t: Supplies the token string to be parsed.
 *
 * Return: The parsed action type.
 */
static enum ipe_action_type parse_action(char *t)
{ … }

static const match_table_t property_tokens = …;

/**
 * parse_property() - Parse a rule property given a token string.
 * @t: Supplies the token string to be parsed.
 * @r: Supplies the ipe_rule the parsed property will be associated with.
 *
 * This function parses and associates a property with an IPE rule based
 * on a token string.
 *
 * Return:
 * * %0		- Success
 * * %-ENOMEM	- Out of memory (OOM)
 * * %-EBADMSG	- The supplied token cannot be parsed
 */
static int parse_property(char *t, struct ipe_rule *r)
{ … }

/**
 * parse_rule() - parse a policy rule line.
 * @line: Supplies rule line to be parsed.
 * @p: Supplies the partial parsed policy.
 *
 * Return:
 * * 0		- Success
 * * %-ENOMEM	- Out of memory (OOM)
 * * %-EBADMSG	- Policy syntax error
 */
static int parse_rule(char *line, struct ipe_parsed_policy *p)
{ … }

/**
 * ipe_free_parsed_policy() - free a parsed policy structure.
 * @p: Supplies the parsed policy.
 */
void ipe_free_parsed_policy(struct ipe_parsed_policy *p)
{ … }

/**
 * validate_policy() - validate a parsed policy.
 * @p: Supplies the fully parsed policy.
 *
 * Given a policy structure that was just parsed, validate that all
 * operations have their default rules or a global default rule is set.
 *
 * Return:
 * * %0		- Success
 * * %-EBADMSG	- Policy is invalid
 */
static int validate_policy(const struct ipe_parsed_policy *p)
{ … }

/**
 * ipe_parse_policy() - Given a string, parse the string into an IPE policy.
 * @p: partially filled ipe_policy structure to populate with the result.
 *     it must have text and textlen set.
 *
 * Return:
 * * %0		- Success
 * * %-EBADMSG	- Policy is invalid
 * * %-ENOMEM	- Out of Memory
 * * %-ERANGE	- Policy version number overflow
 * * %-EINVAL	- Policy version parsing error
 */
int ipe_parse_policy(struct ipe_policy *p)
{ … }