path: root/security/tomoyo/util.c

/*
 * security/tomoyo/util.c
 *
 * Utility functions for TOMOYO.
 *
 * Copyright (C) 2005-2010  NTT DATA CORPORATION
 */

#include <linux/slab.h>
#include "common.h"

/* Lock for protecting policy. */
DEFINE_MUTEX(tomoyo_policy_lock);

/* Has /sbin/init started? */
bool tomoyo_policy_loaded;

/**
 * tomoyo_parse_ulong - Parse an "unsigned long" value.
 *
 * @result: Pointer to "unsigned long".
 * @str:    Pointer to string to parse.
 *
 * Returns value type on success, 0 otherwise.
 *
 * The @src is updated to point the first character after the value
 * on success.
 */
static u8 tomoyo_parse_ulong(unsigned long *result, char **str)
{
	const char *cp = *str;
	char *ep;
	int base = 10;
	if (*cp == '0') {
		char c = *(cp + 1);
		if (c == 'x' || c == 'X') {
			base = 16;
			cp += 2;
		} else if (c >= '0' && c <= '7') {
			base = 8;
			cp++;
		}
	}
	*result = simple_strtoul(cp, &ep, base);
	if (cp == ep)
		return 0;
	*str = ep;
	switch (base) {
	case 16:
		return TOMOYO_VALUE_TYPE_HEXADECIMAL;
	case 8:
		return TOMOYO_VALUE_TYPE_OCTAL;
	default:
		return TOMOYO_VALUE_TYPE_DECIMAL;
	}
}

/**
 * tomoyo_print_ulong - Print an "unsigned long" value.
 *
 * @buffer:     Pointer to buffer.
 * @buffer_len: Size of @buffer.
 * @value:      An "unsigned long" value.
 * @type:       Type of @value.
 *
 * Returns nothing.
 */
void tomoyo_print_ulong(char *buffer, const int buffer_len,
			const unsigned long value, const u8 type)
{
	if (type == TOMOYO_VALUE_TYPE_DECIMAL)
		snprintf(buffer, buffer_len, "%lu", value);
	else if (type == TOMOYO_VALUE_TYPE_OCTAL)
		snprintf(buffer, buffer_len, "0%lo", value);
	else if (type == TOMOYO_VALUE_TYPE_HEXADECIMAL)
		snprintf(buffer, buffer_len, "0x%lX", value);
	else
		snprintf(buffer, buffer_len, "type(%u)", type);
}

/**
 * tomoyo_parse_name_union - Parse a tomoyo_name_union.
 *
 * @filename: Name or name group.
 * @ptr:      Pointer to "struct tomoyo_name_union".
 *
 * Returns true on success, false otherwise.
 */
bool tomoyo_parse_name_union(const char *filename,
			     struct tomoyo_name_union *ptr)
{
	if (!tomoyo_correct_word(filename))
		return false;
	if (filename[0] == '@') {
		ptr->group = tomoyo_get_group(filename + 1, TOMOYO_PATH_GROUP);
		ptr->is_group = true;
		return ptr->group != NULL;
	}
	ptr->filename = tomoyo_get_name(filename);
	ptr->is_group = false;
	return ptr->filename != NULL;
}

/**
 * tomoyo_parse_number_union - Parse a tomoyo_number_union.
 *
 * @data: Number or number range or number group.
 * @ptr:  Pointer to "struct tomoyo_number_union".
 *
 * Returns true on success, false otherwise.
 */
bool tomoyo_parse_number_union(char *data, struct tomoyo_number_union *num)
{
	u8 type;
	unsigned long v;
	memset(num, 0, sizeof(*num));
	if (data[0] == '@') {
		if (!tomoyo_correct_word(data))
			return false;
		num->group = tomoyo_get_group(data + 1, TOMOYO_NUMBER_GROUP);
		num->is_group = true;
		return num->group != NULL;
	}
	type = tomoyo_parse_ulong(&v, &data);
	if (!type)
		return false;
	num->values[0] = v;
	num->min_type = type;
	if (!*data) {
		num->values[1] = v;
		num->max_type = type;
		return true;
	}
	if (*data++ != '-')
		return false;
	type = tomoyo_parse_ulong(&v, &data);
	if (!type || *data)
		return false;
	num->values[1] = v;
	num->max_type = type;
	return true;
}

/**
 * tomoyo_byte_range - Check whether the string is a \ooo style octal value.
 *
 * @str: Pointer to the string.
 *
 * Returns true if @str is a \ooo style octal value, false otherwise.
 *
 * TOMOYO uses \ooo style representation for 0x01 - 0x20 and 0x7F - 0xFF.
 * This function verifies that \ooo is in valid range.
 */
static inline bool tomoyo_byte_range(const char *str)
{
	return *str >= '0' && *str++ <= '3' &&
		*str >= '0' && *str++ <= '7' &&
		*str >= '0'