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;

/*
 * 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,
};

/**
 * 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;
	return pos;
}

/**
 * tomoyo_parse_ulong - Parse an "unsigned long" value.
 *
 * @result: Pointer to "unsigned long".
 * @str:    Pointer to string to parse.
 *
 * Returns one of values in "enum tomoyo_value_type".
 *
 * 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 TOMOYO_VALUE_TYPE_INVALID;
	*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.
 *
 * @param: Pointer to "struct tomoyo_acl_param".
 * @ptr:   Pointer to "struct tomoyo_name_union".
 *
 * Returns true on success, false otherwise.
 */
bool tomoyo_parse_name_union(struct tomoyo_acl_param *param,
			     struct tomoyo_name_union