path: root/security/tomoyo/file.c

/*
 * security/tomoyo/file.c
 *
 * Implementation of the Domain-Based Mandatory Access Control.
 *
 * Copyright (C) 2005-2009  NTT DATA CORPORATION
 *
 * Version: 2.2.0   2009/04/01
 *
 */

#include "common.h"
#include "tomoyo.h"
#include "realpath.h"
#define ACC_MODE(x) ("\000\004\002\006"[(x)&O_ACCMODE])

/* Structure for "allow_read" keyword. */
struct tomoyo_globally_readable_file_entry {
	struct list_head list;
	const struct tomoyo_path_info *filename;
	bool is_deleted;
};

/* Structure for "file_pattern" keyword. */
struct tomoyo_pattern_entry {
	struct list_head list;
	const struct tomoyo_path_info *pattern;
	bool is_deleted;
};

/* Structure for "deny_rewrite" keyword. */
struct tomoyo_no_rewrite_entry {
	struct list_head list;
	const struct tomoyo_path_info *pattern;
	bool is_deleted;
};

/* Keyword array for single path operations. */
static const char *tomoyo_sp_keyword[TOMOYO_MAX_SINGLE_PATH_OPERATION] = {
	[TOMOYO_TYPE_READ_WRITE_ACL] = "read/write",
	[TOMOYO_TYPE_EXECUTE_ACL]    = "execute",
	[TOMOYO_TYPE_READ_ACL]       = "read",
	[TOMOYO_TYPE_WRITE_ACL]      = "write",
	[TOMOYO_TYPE_CREATE_ACL]     = "create",
	[TOMOYO_TYPE_UNLINK_ACL]     = "unlink",
	[TOMOYO_TYPE_MKDIR_ACL]      = "mkdir",
	[TOMOYO_TYPE_RMDIR_ACL]      = "rmdir",
	[TOMOYO_TYPE_MKFIFO_ACL]     = "mkfifo",
	[TOMOYO_TYPE_MKSOCK_ACL]     = "mksock",
	[TOMOYO_TYPE_MKBLOCK_ACL]    = "mkblock",
	[TOMOYO_TYPE_MKCHAR_ACL]     = "mkchar",
	[TOMOYO_TYPE_TRUNCATE_ACL]   = "truncate",
	[TOMOYO_TYPE_SYMLINK_ACL]    = "symlink",
	[TOMOYO_TYPE_REWRITE_ACL]    = "rewrite",
};

/* Keyword array for double path operations. */
static const char *tomoyo_dp_keyword[TOMOYO_MAX_DOUBLE_PATH_OPERATION] = {
	[TOMOYO_TYPE_LINK_ACL]    = "link",
	[TOMOYO_TYPE_RENAME_ACL]  = "rename",
};

/**
 * tomoyo_sp2keyword - Get the name of single path operation.
 *
 * @operation: Type of operation.
 *
 * Returns the name of single path operation.
 */
const char *tomoyo_sp2keyword(const u8 operation)
{
	return (operation < TOMOYO_MAX_SINGLE_PATH_OPERATION)
		? tomoyo_sp_keyword[operation] : NULL;
}

/**
 * tomoyo_dp2keyword - Get the name of double path operation.
 *
 * @operation: Type of operation.
 *
 * Returns the name of double path operation.
 */
const char *tomoyo_dp2keyword(const u8 operation)
{
	return (operation < TOMOYO_MAX_DOUBLE_PATH_OPERATION)
		? tomoyo_dp_keyword[operation] : NULL;
}

/**
 * tomoyo_strendswith - Check whether the token ends with the given token.
 *
 * @name: The token to check.
 * @tail: The token to find.
 *
 * Returns true if @name ends with @tail, false otherwise.
 */
static bool tomoyo_strendswith(const char *name, const char *tail)
{
	int len;

	if (!name || !tail)
		return false;
	len = strlen(name) - strlen(tail);
	return len >= 0 && !strcmp(name + len, tail);
}

/**
 * tomoyo_get_path - Get realpath.
 *
 * @path: Pointer to "struct path".
 *
 * Returns pointer to "struct tomoyo_path_info" on success, NULL otherwise.
 */
static struct tomoyo_path_info *tomoyo_get_path(struct path *path