path: root/security/tomoyo/util.c

/*
 * security/tomoyo/util.c
 *
 * Copyright (C) 2005-2011  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;

/*
 * Mapping table from "enum tomoyo_mac_index" to
 * "enum tomoyo_mac_category_index".
 */
const u8 tomoyo_index2category[TOMOYO_MAX_MAC_INDEX] = {
	/* CONFIG::file group */
	[TOMOYO_MAC_FILE_EXECUTE]    = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_OPEN]       = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_CREATE]     = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_UNLINK]     = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_GETATTR]    = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_MKDIR]      = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_RMDIR]      = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_MKFIFO]     = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_MKSOCK]     = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_TRUNCATE]   = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_SYMLINK]    = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_MKBLOCK]    = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_MKCHAR]     = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_LINK]       = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_RENAME]     = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_CHMOD]      = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_CHOWN]      = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_CHGRP]      = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_IOCTL]      = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_CHROOT]     = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_MOUNT]      = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_UMOUNT]     = TOMOYO_MAC_CATEGORY_FILE,
	[TOMOYO_MAC_FILE_PIVOT_ROOT] = TOMOYO_MAC_CATEGORY_FILE,
	/* CONFIG::misc group */
	[TOMOYO_MAC_ENVIRON]         = TOMOYO_MAC_CATEGORY_MISC,
};

/**
 * tomoyo_convert_time - Convert time_t to YYYY/MM/DD hh/mm/ss.
 *
 * @time:  Seconds since 1970/01/01 00:00:00.
 * @stamp: Pointer to "struct tomoyo_time".
 *
 * Returns nothing.
 *
 * This function does not handle Y2038 problem.
 */
void tomoyo_convert_time(time_t time, struct tomoyo_time *stamp)
{
	static const u16 tomoyo_eom[2][12] = {
		{ 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
		{ 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
	};
	u16 y;
	u8 m;
	bool r;
	stamp->sec = time % 60;
	time /= 60;
	stamp->min = time % 60;
	time /= 60;
	stamp->hour = time % 24;
	time /= 24;
	for (y = 1970; ; y++) {
		const unsigned short days = (y & 3) ? 365 : 366;
		if (time < days)
			break;
		time -= days;
	}
	r = (y & 3) == 0;
	for (m = 0; m < 11 && time >= tomoyo_eom[r][m]; m++)
		;
	if (m)
		time -= tomoyo_eom[r][m - 1];
	stamp->year = y;
	stamp->month = ++m;
	stamp->day = ++time;
}

/**
 * tomoyo_permstr - Find permission keywords.
 *
 * @string: String representation for permissions in foo/bar/buz format.
 * @keyword: Keyword to find from @string/
 *
 * Returns ture if @keyword was found in @string, false otherwise.
 *
 * This function assumes that strncmp(w1, w2, strlen(w1)) != 0 if w1 != w2.
 */
bool tomoyo_permstr(const char *string, const char *keyword)
{
	const char *cp = strstr(string, keyword);
	if (cp)
		return cp == string || *(cp - 1) == '/';
	return false;
}

/**
 * tomoyo_read_token - Read a word from a line.
 *
 * @param: Pointer to "struct tomoyo_acl_param".
 *
 * Returns a word on success, "" otherwise.
 *
 * To allow the caller to skip NULL check, this function returns "" rather than
 * NULL if there is no more words to read.
 */
char *tomoyo_read_token(struct tomoyo_acl_param *param)
{
	char *pos = param->data;
	char *del = strchr(pos, ' ');
	if (del)
		*del++ = '\0';
	else
		del = pos + strlen(pos);
	param->data = del