security/tomoyo/tomoyo.c - arm/linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * security/tomoyo/tomoyo.c
  *
  * Copyright (C) 2005-2011  NTT DATA CORPORATION
  */

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

 /**
  * tomoyo_cred_alloc_blank - Target for security_cred_alloc_blank().
  *
  * @new: Pointer to "struct cred".
  * @gfp: Memory allocation flags.
  *
  * Returns 0.
  */
 static int tomoyo_cred_alloc_blank(struct cred *new, gfp_t gfp)
 {
 	new->security = NULL;
 	return 0;
 }

 /**
  * tomoyo_cred_prepare - Target for security_prepare_creds().
  *
  * @new: Pointer to "struct cred".
  * @old: Pointer to "struct cred".
  * @gfp: Memory allocation flags.
  *
  * Returns 0.
  */
 static int tomoyo_cred_prepare(struct cred *new, const struct cred *old,
 			       gfp_t gfp)
 {
 	struct tomoyo_domain_info *domain = old->security;
 	new->security = domain;
 	if (domain)
 		atomic_inc(&domain->users);
 	return 0;
 }

 /**
  * tomoyo_cred_transfer - Target for security_transfer_creds().
  *
  * @new: Pointer to "struct cred".
  * @old: Pointer to "struct cred".
  */
 static void tomoyo_cred_transfer(struct cred *new, const struct cred *old)
 {
 	tomoyo_cred_prepare(new, old, 0);
 }

 /**
  * tomoyo_cred_free - Target for security_cred_free().
  *
  * @cred: Pointer to "struct cred".
  */
 static void tomoyo_cred_free(struct cred *cred)
 {
 	struct tomoyo_domain_info *domain = cred->security;
 	if (domain)
 		atomic_dec(&domain->users);
 }

 /**
  * tomoyo_bprm_set_creds - Target for security_bprm_set_creds().
  *
  * @bprm: Pointer to "struct linux_binprm".
  *
  * Returns 0 on success, negative value otherwise.
  */
 static int tomoyo_bprm_set_creds(struct linux_binprm *bprm)
 {
 	/*
 	 * Do only if this function is called for the first time of an execve
 	 * operation.
 	 */
 	if (bprm->called_set_creds)
 		return 0;
 #ifndef CONFIG_SECURITY_TOMOYO_OMIT_USERSPACE_LOADER
 	/*
 	 * Load policy if /sbin/tomoyo-init exists and /sbin/init is requested
 	 * for the first time.
 	 */
 	if (!tomoyo_policy_loaded)
 		tomoyo_load_policy(bprm->filename);
 #endif
 	/*
 	 * Release reference to "struct tomoyo_domain_info" stored inside
 	 * "bprm->cred->security". New reference to "struct tomoyo_domain_info"
 	 * stored inside "bprm->cred->security" will be acquired later inside
 	 * tomoyo_find_next_domain().
 	 */
 	atomic_dec(&((struct tomoyo_domain_info *)
 		     bprm->cred->security)->users);
 	/*
 	 * Tell tomoyo_bprm_check_security() is called for the first time of an
 	 * execve operation.
 	 */
 	bprm->cred->security = NULL;
 	return 0;
 }

 /**
  * tomoyo_bprm_check_security - Target for security_bprm_check().
  *
  * @bprm: Pointer to "struct linux_binprm".
  *
  * Returns 0 on success, negative value otherwise.
  */
 static int tomoyo_bprm_check_security(struct linux_binprm *bprm)
 {
 	struct tomoyo_domain_info *domain = bprm->cred->security;

 	/*
 	 * Execute permission is checked against pathname passed to do_execve()
 	 * using current domain.
 	 */
 	if (!domain) {
 		const int idx = tomoyo_read_lock();
 		const int err = tomoyo_find_next_domain(bprm);
 		tomoyo_read_unlock(idx);
 		return err;
 	}
 	/*
 	 * Read permission is checked against interpreters using next domain.
 	 */
 	return tomoyo_check_open_permission(domain, &bprm->file->f_path,
 					    O_RDONLY);
 }

 /**
  * tomoyo_inode_getattr - Target for security_inode_getattr().
  *
  * @mnt:    Pointer to "struct vfsmount".
  * @dentry: Pointer to "struct dentry".
  *
  * Returns 0 on success, negative value otherwise.
  */
 static int tomoyo_inode_getattr(const struct path *path)
 {
 	return tomoyo_path_perm(TOMOYO_TYPE_GETATTR, path, NULL);
 }

 /**
  * tomoyo_path_truncate - Target for security_path_truncate().
  *
  * @path: Pointer to "struct path".
  *
  * Returns 0 on success, negative value otherwise.
  */
 static int tomoyo_path_truncate(const struct path *path)
 {
 	return tomoyo_path_perm(TOMOYO_TYPE_TRUNCATE, path, NULL);
 }

 /**
  * tomoyo_path_unlink - Target for security_path_unlink().
  *
  * @parent: Pointer to "struct path".
  * @dentry: Pointer to "struct dentry".
  *
  * Returns 0 on success, negative value otherwise.
  */
 static int tomoyo_path_unlink(const struct path *parent, struct dentry *dentry)
 {
 	struct path path = { .mnt = parent->mnt, .dentry = dentry };
 	return tomoyo_path_perm(TOMOYO_TYPE_UNLINK, &path, NULL);
 }

 /**
  * tomoyo_path_mkdir - Target for security_path_mkdir().
  *
  * @parent: Pointer to "struct path".
  * @dentry: Pointer to "struct dentry".
  * @mode:   DAC permission mode.
  *
  * Returns 0 on success, negative value otherwise.
  */
 static int tomoyo_path_mkdir(const struct path *parent, struct dentry *dentry,
 			     umode_t mode)
 {
 	struct path path = { .mnt = parent->mnt, .dentry = dentry };
 	return tomoyo_path_number_perm(TOMOYO_TYPE_MKDIR, &path,
 				       mode & S_IALLUGO);
 }

 /**
  * tomoyo_path_rmdir - Target for security_path_rmdir().
  *
  * @parent: Pointer to "struct path".
  * @dentry: Pointer to "struct dentry".
  *
  * Returns 0 on success, negative value otherwise.
  */
 static int tomoyo_path_rmdir(const struct path *parent, struct dentry *dentry)
 {
 	struct path path = { .mnt = parent->mnt, .dentry = dentry };
 	return tomoyo_path_perm(TOMOYO_TYPE_RMDIR, &path, NULL);
 }

 /**
  * tomoyo_path_symlink - Target for security_path_symlink().
  *
  * @parent:   Pointer to "struct path".
  * @dentry:   Pointer to "struct dentry".
  * @old_name: Symlink's content.
  *
  * Returns 0 on success, negative value otherwise.
  */
 static int tomoyo_path_symlink(const struct path *parent, struct dentry *dentry,
 			       const char *old_name)
 {
 	struct path path = { .mnt = parent->mnt, .dentry = dentry };
 	return tomoyo_path_perm(TOMOYO_TYPE_SYMLINK, &path, old_name);
 }

 /**
  * tomoyo_path_mknod - Target for security_path_mknod().
  *
  * @parent: Pointer to "struct path".
  * @dentry: Pointer to "struct dentry".
  * @mode:   DAC permission mode.
  * @dev:    Device attributes.
  *
  * Returns 0 on success, negative value otherwise.
  */
 static int tomoyo_path_mknod(const struct path *parent, struct dentry *dentry,
 			     umode_t mode, unsigned int dev)
 {
 	struct path path = { .mnt = parent->mnt, .dentry = dentry };
 	int type = TOMOYO_TYPE_CREATE;
 	const unsigned int perm = mode & S_IALLUGO;

 	switch (mode & S_IFMT) {
 	case S_IFCHR:
 		type = TOMOYO_TYPE_MKCHAR;
 		break;
 	case S_IFBLK:
 		type = TOMOYO_TYPE_MKBLOCK;
 		break;
 	default:
 		goto no_dev;
 	}
 	return tomoyo_mkdev_perm(type, &path, perm, dev);
  no_dev:
 	switch (mode & S_IFMT) {
 	case S_IFIFO:
 		type = TOMOYO_TYPE_MKFIFO;
 		break;
 	case S_IFSOCK:
 		type = TOMOYO_TYPE_MKSOCK;
 		break;
 	}
 	return tomoyo_path_number_perm(type, &path, perm);
 }

 /**
  * tomoyo_path_link - Target for security_path_link().
  *
  * @old_dentry: Pointer to "struct dentry".
  * @new_dir:    Pointer to "struct path".
  * @new_dentry: Pointer to "struct dentry".
  *
  * Returns 0 on success, negative value otherwise.
  */
 static int tomoyo_path_link(struct dentry *old_dentry, const struct path *new_dir,
 			    struct dentry *new_dentry)
 {
 	struct path path1 = { .mnt = new_dir->mnt, .dentry = old_dentry };
 	struct path path2 = { .mnt = new_dir->mnt, .dentry = new_dentry };
 	return tomoyo_path2_perm(TOMOYO_TYPE_LINK, &path1, &path2);
 }

 /**
  * tomoyo_path_rename - Target for security_path_rename().
  *
  * @old_parent: Pointer to "struct path".
  * @old_dentry: Pointer to "struct dentry".
  * @new_parent: Pointer to "struct path".
  * @new_dentry: Pointer to "struct dentry".
  *
  * Returns 0 on success, negative value otherwise.
  */
 static int tomoyo_path_rename(const struct path *old_parent,
 			      struct dentry *old_dentry,
 			      const struct path *new_parent,
 			      struct dentry *new_dentry)
 {
 	struct path path1 = { .mnt = old_parent->mnt, .dentry = old_dentry };
 	struct path path2 = { .mnt = new_parent->mnt, .dentry = new_dentry };
 	return tomoyo_path2_perm(TOMOYO_TYPE_RENAME, &path1, &path2);
 }

 /**
  * tomoyo_file_fcntl - Target for security_file_fcntl().
  *
  * @file: Pointer to "struct file".
  * @cmd:  Command for fcntl().
  * @arg:  Argument for @cmd.
  *
  * Returns 0 on success, negative value otherwise.
  */
 static int tomoyo_file_fcntl(struct file *file, unsigned int cmd,
 			     unsigned long arg)
 {
 	if (!(cmd == F_SETFL && ((arg ^ file->f_flags) & O_APPEND)))
 		return 0;
 	return tomoyo_check_open_permission(tomoyo_domain(), &file->f_path,
 					    O_WRONLY | (arg & O_APPEND));
 }

 /**
  * tomoyo_file_open - Target for security_file_open().
  *
  * @f:    Pointer to "struct file".
  * @cred: Pointer to "struct cred".
  *
  * Returns 0 on success, negative value otherwise.
  */
 static int tomoyo_file_open(struct file *f, const struct cred *cred)
 {
 	int flags = f->f_flags;
 	/* Don't check read permission here if called from do_execve(). */
 	if (current->in_execve)
 		return 0;
 	return tomoyo_check_open_permission(tomoyo_domain(), &f->f_path, flags);
 }

 /**
  * tomoyo_file_ioctl - Target for security_file_ioctl().
  *
  * @file: Pointer to "struct file".
  * @cmd:  Command for ioctl().
  * @arg:  Argument for @cmd.
  *
  * Returns 0 on success, negative value otherwise.
  */
 static int tomoyo_file_ioctl(struct file *file, unsigned int cmd,
 			     unsigned long arg)
 {
 	return tomoyo_path_number_perm(TOMOYO_TYPE_IOCTL, &file->f_path, cmd);
 }

 /**
  * tomoyo_path_chmod - Target for security_path_chmod().
  *
  * @path: Pointer to "struct path".
  * @mode: DAC permission mode.
  *
  * Returns 0 on success, negative value otherwise.
  */
 static int tomoyo_path_chmod(const struct path *path, umode_t mode)
 {
 	return tomoyo_path_number_perm(TOMOYO_TYPE_CHMOD, path,
 				       mode & S_IALLUGO);
 }

 /**
  * tomoyo_path_chown - Target for security_path_chown().
  *
  * @path: Pointer to "struct path".
  * @uid:  Owner ID.
  * @gid:  Group ID.
  *
  * Returns 0 on success, negative value otherwise.
  */
 static int tomoyo_path_chown(const struct path *path, kuid_t uid, kgid_t gid)
 {
 	int error = 0;
 	if (uid_valid(uid))
 		error = tomoyo_path_number_perm(TOMOYO_TYPE_CHOWN, path,
 						from_kuid(&init_user_ns, uid));
 	if (!error && gid_valid(gid))
 		error = tomoyo_path_number_perm(TOMOYO_TYPE_CHGRP, path,
 						from_kgid(&init_user_ns, gid));
 	return error;
 }

 /**
  * tomoyo_path_chroot - Target for security_path_chroot().
  *
  * @path: Pointer to "struct path".
  *
  * Returns 0 on success, negative value otherwise.
  */
 static int tomoyo_path_chroot(const struct path *path)
 {
 	return tomoyo_path_perm(TOMOYO_TYPE_CHROOT, path, NULL);
 }

 /**
  * tomoyo_sb_mount - Target for security_sb_mount().
  *
  * @dev_name: Name of device file. Maybe NULL.
  * @path:     Pointer to "struct path".
  * @type:     Name of filesystem type. Maybe NULL.
  * @flags:    Mount options.
  * @data:     Optional data. Maybe NULL.
  *
  * Returns 0 on success, negative value otherwise.
  */
 static int tomoyo_sb_mount(const char *dev_name, const struct path *path,
 			   const char *type, unsigned long flags, void *data)
 {
 	return tomoyo_mount_permission(dev_name, path, type, flags, data);
 }

 /**
  * tomoyo_sb_umount - Target for security_sb_umount().
  *
  * @mnt:   Pointer to "struct vfsmount".
  * @flags: Unmount options.
  *
  * Returns 0 on success, negative value otherwise.
  */
 static int tomoyo_sb_umount(struct vfsmount *mnt, int flags)
 {
 	struct path path = { .mnt = mnt, .dentry = mnt->mnt_root };
 	return tomoyo_path_perm(TOMOYO_TYPE_UMOUNT, &path, NULL);
 }

 /**
  * tomoyo_sb_pivotroot - Target for security_sb_pivotroot().
  *
  * @old_path: Pointer to "struct path".
  * @new_path: Pointer to "struct path".
  *
  * Returns 0 on success, negative value otherwise.
  */
 static int tomoyo_sb_pivotroot(const struct path *old_path, const struct path *new_path)
 {
 	return tomoyo_path2_perm(TOMOYO_TYPE_PIVOT_ROOT, new_path, old_path);
 }

 /**
  * tomoyo_socket_listen - Check permission for listen().
  *
  * @sock:    Pointer to "struct socket".
  * @backlog: Backlog parameter.
  *
  * Returns 0 on success, negative value otherwise.
  */
 static int tomoyo_socket_listen(struct socket *sock, int backlog)
 {
 	return tomoyo_socket_listen_permission(sock);
 }

 /**
  * tomoyo_socket_connect - Check permission for connect().
  *
  * @sock:     Pointer to "struct socket".
  * @addr:     Pointer to "struct sockaddr".
  * @addr_len: Size of @addr.
  *
  * Returns 0 on success, negative value otherwise.
  */
 static int tomoyo_socket_connect(struct socket *sock, struct sockaddr *addr,
 				 int addr_len)
 {
 	return tomoyo_socket_connect_permission(sock, addr, addr_len);
 }

 /**
  * tomoyo_socket_bind - Check permission for bind().
  *
  * @sock:     Pointer to "struct socket".
  * @addr:     Pointer to "struct sockaddr".
  * @addr_len: Size of @addr.
  *
  * Returns 0 on success, negative value otherwise.
  */
 static int tomoyo_socket_bind(struct socket *sock, struct sockaddr *addr,
 			      int addr_len)
 {
 	return tomoyo_socket_bind_permission(sock, addr, addr_len);
 }

 /**
  * tomoyo_socket_sendmsg - Check permission for sendmsg().
  *
  * @sock: Pointer to "struct socket".
  * @msg:  Pointer to "struct msghdr".
  * @size: Size of message.
  *
  * Returns 0 on success, negative value otherwise.
  */
 static int tomoyo_socket_sendmsg(struct socket *sock, struct msghdr *msg,
 				 int size)
 {
 	return tomoyo_socket_sendmsg_permission(sock, msg, size);
 }

 /*
  * tomoyo_security_ops is a "struct security_operations" which is used for
  * registering TOMOYO.
  */
 static struct security_hook_list tomoyo_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(cred_alloc_blank, tomoyo_cred_alloc_blank),
 	LSM_HOOK_INIT(cred_prepare, tomoyo_cred_prepare),
 	LSM_HOOK_INIT(cred_transfer, tomoyo_cred_transfer),
 	LSM_HOOK_INIT(cred_free, tomoyo_cred_free),
 	LSM_HOOK_INIT(bprm_set_creds, tomoyo_bprm_set_creds),
 	LSM_HOOK_INIT(bprm_check_security, tomoyo_bprm_check_security),
 	LSM_HOOK_INIT(file_fcntl, tomoyo_file_fcntl),
 	LSM_HOOK_INIT(file_open, tomoyo_file_open),
 	LSM_HOOK_INIT(path_truncate, tomoyo_path_truncate),
 	LSM_HOOK_INIT(path_unlink, tomoyo_path_unlink),
 	LSM_HOOK_INIT(path_mkdir, tomoyo_path_mkdir),
 	LSM_HOOK_INIT(path_rmdir, tomoyo_path_rmdir),
 	LSM_HOOK_INIT(path_symlink, tomoyo_path_symlink),
 	LSM_HOOK_INIT(path_mknod, tomoyo_path_mknod),
 	LSM_HOOK_INIT(path_link, tomoyo_path_link),
 	LSM_HOOK_INIT(path_rename, tomoyo_path_rename),
 	LSM_HOOK_INIT(inode_getattr, tomoyo_inode_getattr),
 	LSM_HOOK_INIT(file_ioctl, tomoyo_file_ioctl),
 	LSM_HOOK_INIT(path_chmod, tomoyo_path_chmod),
 	LSM_HOOK_INIT(path_chown, tomoyo_path_chown),
 	LSM_HOOK_INIT(path_chroot, tomoyo_path_chroot),
 	LSM_HOOK_INIT(sb_mount, tomoyo_sb_mount),
 	LSM_HOOK_INIT(sb_umount, tomoyo_sb_umount),
 	LSM_HOOK_INIT(sb_pivotroot, tomoyo_sb_pivotroot),
 	LSM_HOOK_INIT(socket_bind, tomoyo_socket_bind),
 	LSM_HOOK_INIT(socket_connect, tomoyo_socket_connect),
 	LSM_HOOK_INIT(socket_listen, tomoyo_socket_listen),
 	LSM_HOOK_INIT(socket_sendmsg, tomoyo_socket_sendmsg),
 };

 /* Lock for GC. */
 DEFINE_SRCU(tomoyo_ss);

 /**
  * tomoyo_init - Register TOMOYO Linux as a LSM module.
  *
  * Returns 0.
  */
 static int __init tomoyo_init(void)
 {
 	struct cred *cred = (struct cred *) current_cred();

 	if (!security_module_enable("tomoyo"))
 		return 0;
 	/* register ourselves with the security framework */
 	security_add_hooks(tomoyo_hooks, ARRAY_SIZE(tomoyo_hooks), "tomoyo");
 	printk(KERN_INFO "TOMOYO Linux initialized\n");
 	cred->security = &tomoyo_kernel_domain;
 	tomoyo_mm_init();
 	return 0;
 }

 security_initcall(tomoyo_init);
	// SPDX-License-Identifier: GPL-2.0
	/*
	* security/tomoyo/tomoyo.c
	*
	* Copyright (C) 2005-2011 NTT DATA CORPORATION
	*/

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

	/**
	* tomoyo_cred_alloc_blank - Target for security_cred_alloc_blank().
	*
	* @new: Pointer to "struct cred".
	* @gfp: Memory allocation flags.
	*
	* Returns 0.
	*/
	static int tomoyo_cred_alloc_blank(struct cred *new, gfp_t gfp)
	{
	new->security = NULL;
	return 0;
	}

	/**
	* tomoyo_cred_prepare - Target for security_prepare_creds().
	*
	* @new: Pointer to "struct cred".
	* @old: Pointer to "struct cred".
	* @gfp: Memory allocation flags.
	*
	* Returns 0.
	*/
	static int tomoyo_cred_prepare(struct cred new, const struct cred old,
	gfp_t gfp)
	{
	struct tomoyo_domain_info *domain = old->security;
	new->security = domain;
	if (domain)
	atomic_inc(&domain->users);
	return 0;
	}

	/**
	* tomoyo_cred_transfer - Target for security_transfer_creds().
	*
	* @new: Pointer to "struct cred".
	* @old: Pointer to "struct cred".
	*/
	static void tomoyo_cred_transfer(struct cred new, const struct cred old)
	{
	tomoyo_cred_prepare(new, old, 0);
	}

	/**
	* tomoyo_cred_free - Target for security_cred_free().
	*
	* @cred: Pointer to "struct cred".
	*/
	static void tomoyo_cred_free(struct cred *cred)
	{
	struct tomoyo_domain_info *domain = cred->security;
	if (domain)
	atomic_dec(&domain->users);
	}

	/**
	* tomoyo_bprm_set_creds - Target for security_bprm_set_creds().
	*
	* @bprm: Pointer to "struct linux_binprm".
	*
	* Returns 0 on success, negative value otherwise.
	*/
	static int tomoyo_bprm_set_creds(struct linux_binprm *bprm)
	{
	/*
	* Do only if this function is called for the first time of an execve
	* operation.
	*/
	if (bprm->called_set_creds)
	return 0;
	#ifndef CONFIG_SECURITY_TOMOYO_OMIT_USERSPACE_LOADER
	/*
	* Load policy if /sbin/tomoyo-init exists and /sbin/init is requested
	* for the first time.
	*/
	if (!tomoyo_policy_loaded)
	tomoyo_load_policy(bprm->filename);
	#endif
	/*
	* Release reference to "struct tomoyo_domain_info" stored inside
	* "bprm->cred->security". New reference to "struct tomoyo_domain_info"
	* stored inside "bprm->cred->security" will be acquired later inside
	* tomoyo_find_next_domain().
	*/
	atomic_dec(&((struct tomoyo_domain_info *)
	bprm->cred->security)->users);
	/*
	* Tell tomoyo_bprm_check_security() is called for the first time of an
	* execve operation.
	*/
	bprm->cred->security = NULL;
	return 0;
	}

	/**
	* tomoyo_bprm_check_security - Target for security_bprm_check().
	*
	* @bprm: Pointer to "struct linux_binprm".
	*
	* Returns 0 on success, negative value otherwise.
	*/
	static int tomoyo_bprm_check_security(struct linux_binprm *bprm)
	{
	struct tomoyo_domain_info *domain = bprm->cred->security;

	/*
	* Execute permission is checked against pathname passed to do_execve()
	* using current domain.
	*/
	if (!domain) {
	const int idx = tomoyo_read_lock();
	const int err = tomoyo_find_next_domain(bprm);
	tomoyo_read_unlock(idx);
	return err;
	}
	/*
	* Read permission is checked against interpreters using next domain.
	*/
	return tomoyo_check_open_permission(domain, &bprm->file->f_path,
	O_RDONLY);
	}

	/**
	* tomoyo_inode_getattr - Target for security_inode_getattr().
	*
	* @mnt: Pointer to "struct vfsmount".
	* @dentry: Pointer to "struct dentry".
	*
	* Returns 0 on success, negative value otherwise.
	*/
	static int tomoyo_inode_getattr(const struct path *path)
	{
	return tomoyo_path_perm(TOMOYO_TYPE_GETATTR, path, NULL);
	}

	/**
	* tomoyo_path_truncate - Target for security_path_truncate().
	*
	* @path: Pointer to "struct path".
	*
	* Returns 0 on success, negative value otherwise.
	*/
	static int tomoyo_path_truncate(const struct path *path)
	{
	return tomoyo_path_perm(TOMOYO_TYPE_TRUNCATE, path, NULL);
	}

	/**
	* tomoyo_path_unlink - Target for security_path_unlink().
	*
	* @parent: Pointer to "struct path".
	* @dentry: Pointer to "struct dentry".
	*
	* Returns 0 on success, negative value otherwise.
	*/
	static int tomoyo_path_unlink(const struct path parent, struct dentry dentry)
	{
	struct path path = { .mnt = parent->mnt, .dentry = dentry };
	return tomoyo_path_perm(TOMOYO_TYPE_UNLINK, &path, NULL);
	}

	/**
	* tomoyo_path_mkdir - Target for security_path_mkdir().
	*
	* @parent: Pointer to "struct path".
	* @dentry: Pointer to "struct dentry".
	* @mode: DAC permission mode.
	*
	* Returns 0 on success, negative value otherwise.
	*/
	static int tomoyo_path_mkdir(const struct path parent, struct dentry dentry,
	umode_t mode)
	{
	struct path path = { .mnt = parent->mnt, .dentry = dentry };
	return tomoyo_path_number_perm(TOMOYO_TYPE_MKDIR, &path,
	mode & S_IALLUGO);
	}

	/**
	* tomoyo_path_rmdir - Target for security_path_rmdir().
	*
	* @parent: Pointer to "struct path".
	* @dentry: Pointer to "struct dentry".
	*
	* Returns 0 on success, negative value otherwise.
	*/
	static int tomoyo_path_rmdir(const struct path parent, struct dentry dentry)
	{
	struct path path = { .mnt = parent->mnt, .dentry = dentry };
	return tomoyo_path_perm(TOMOYO_TYPE_RMDIR, &path, NULL);
	}

	/**
	* tomoyo_path_symlink - Target for security_path_symlink().
	*
	* @parent: Pointer to "struct path".
	* @dentry: Pointer to "struct dentry".
	* @old_name: Symlink's content.
	*
	* Returns 0 on success, negative value otherwise.
	*/
	static int tomoyo_path_symlink(const struct path parent, struct dentry dentry,
	const char *old_name)
	{
	struct path path = { .mnt = parent->mnt, .dentry = dentry };
	return tomoyo_path_perm(TOMOYO_TYPE_SYMLINK, &path, old_name);
	}

	/**
	* tomoyo_path_mknod - Target for security_path_mknod().
	*
	* @parent: Pointer to "struct path".
	* @dentry: Pointer to "struct dentry".
	* @mode: DAC permission mode.
	* @dev: Device attributes.
	*
	* Returns 0 on success, negative value otherwise.
	*/
	static int tomoyo_path_mknod(const struct path parent, struct dentry dentry,
	umode_t mode, unsigned int dev)
	{
	struct path path = { .mnt = parent->mnt, .dentry = dentry };
	int type = TOMOYO_TYPE_CREATE;
	const unsigned int perm = mode & S_IALLUGO;

	switch (mode & S_IFMT) {
	case S_IFCHR:
	type = TOMOYO_TYPE_MKCHAR;
	break;
	case S_IFBLK:
	type = TOMOYO_TYPE_MKBLOCK;
	break;
	default:
	goto no_dev;
	}
	return tomoyo_mkdev_perm(type, &path, perm, dev);
	no_dev:
	switch (mode & S_IFMT) {
	case S_IFIFO:
	type = TOMOYO_TYPE_MKFIFO;
	break;
	case S_IFSOCK:
	type = TOMOYO_TYPE_MKSOCK;
	break;
	}
	return tomoyo_path_number_perm(type, &path, perm);
	}

	/**
	* tomoyo_path_link - Target for security_path_link().
	*
	* @old_dentry: Pointer to "struct dentry".
	* @new_dir: Pointer to "struct path".
	* @new_dentry: Pointer to "struct dentry".
	*
	* Returns 0 on success, negative value otherwise.
	*/
	static int tomoyo_path_link(struct dentry old_dentry, const struct path new_dir,
	struct dentry *new_dentry)
	{
	struct path path1 = { .mnt = new_dir->mnt, .dentry = old_dentry };
	struct path path2 = { .mnt = new_dir->mnt, .dentry = new_dentry };
	return tomoyo_path2_perm(TOMOYO_TYPE_LINK, &path1, &path2);
	}

	/**
	* tomoyo_path_rename - Target for security_path_rename().
	*
	* @old_parent: Pointer to "struct path".
	* @old_dentry: Pointer to "struct dentry".
	* @new_parent: Pointer to "struct path".
	* @new_dentry: Pointer to "struct dentry".
	*
	* Returns 0 on success, negative value otherwise.
	*/
	static int tomoyo_path_rename(const struct path *old_parent,
	struct dentry *old_dentry,
	const struct path *new_parent,
	struct dentry *new_dentry)
	{
	struct path path1 = { .mnt = old_parent->mnt, .dentry = old_dentry };
	struct path path2 = { .mnt = new_parent->mnt, .dentry = new_dentry };
	return tomoyo_path2_perm(TOMOYO_TYPE_RENAME, &path1, &path2);
	}

	/**
	* tomoyo_file_fcntl - Target for security_file_fcntl().
	*
	* @file: Pointer to "struct file".
	* @cmd: Command for fcntl().
	* @arg: Argument for @cmd.
	*
	* Returns 0 on success, negative value otherwise.
	*/
	static int tomoyo_file_fcntl(struct file *file, unsigned int cmd,
	unsigned long arg)
	{
	if (!(cmd == F_SETFL && ((arg ^ file->f_flags) & O_APPEND)))
	return 0;
	return tomoyo_check_open_permission(tomoyo_domain(), &file->f_path,
	O_WRONLY \| (arg & O_APPEND));
	}

	/**
	* tomoyo_file_open - Target for security_file_open().
	*
	* @f: Pointer to "struct file".
	* @cred: Pointer to "struct cred".
	*
	* Returns 0 on success, negative value otherwise.
	*/
	static int tomoyo_file_open(struct file f, const struct cred cred)
	{
	int flags = f->f_flags;
	/* Don't check read permission here if called from do_execve(). */
	if (current->in_execve)
	return 0;
	return tomoyo_check_open_permission(tomoyo_domain(), &f->f_path, flags);
	}

	/**
	* tomoyo_file_ioctl - Target for security_file_ioctl().
	*
	* @file: Pointer to "struct file".
	* @cmd: Command for ioctl().
	* @arg: Argument for @cmd.
	*
	* Returns 0 on success, negative value otherwise.
	*/
	static int tomoyo_file_ioctl(struct file *file, unsigned int cmd,
	unsigned long arg)
	{
	return tomoyo_path_number_perm(TOMOYO_TYPE_IOCTL, &file->f_path, cmd);
	}

	/**
	* tomoyo_path_chmod - Target for security_path_chmod().
	*
	* @path: Pointer to "struct path".
	* @mode: DAC permission mode.
	*
	* Returns 0 on success, negative value otherwise.
	*/
	static int tomoyo_path_chmod(const struct path *path, umode_t mode)
	{
	return tomoyo_path_number_perm(TOMOYO_TYPE_CHMOD, path,
	mode & S_IALLUGO);
	}

	/**
	* tomoyo_path_chown - Target for security_path_chown().
	*
	* @path: Pointer to "struct path".
	* @uid: Owner ID.
	* @gid: Group ID.
	*
	* Returns 0 on success, negative value otherwise.
	*/
	static int tomoyo_path_chown(const struct path *path, kuid_t uid, kgid_t gid)
	{
	int error = 0;
	if (uid_valid(uid))
	error = tomoyo_path_number_perm(TOMOYO_TYPE_CHOWN, path,
	from_kuid(&init_user_ns, uid));
	if (!error && gid_valid(gid))
	error = tomoyo_path_number_perm(TOMOYO_TYPE_CHGRP, path,
	from_kgid(&init_user_ns, gid));
	return error;
	}

	/**
	* tomoyo_path_chroot - Target for security_path_chroot().
	*
	* @path: Pointer to "struct path".
	*
	* Returns 0 on success, negative value otherwise.
	*/
	static int tomoyo_path_chroot(const struct path *path)
	{
	return tomoyo_path_perm(TOMOYO_TYPE_CHROOT, path, NULL);
	}

	/**
	* tomoyo_sb_mount - Target for security_sb_mount().
	*
	* @dev_name: Name of device file. Maybe NULL.
	* @path: Pointer to "struct path".
	* @type: Name of filesystem type. Maybe NULL.
	* @flags: Mount options.
	* @data: Optional data. Maybe NULL.
	*
	* Returns 0 on success, negative value otherwise.
	*/
	static int tomoyo_sb_mount(const char dev_name, const struct path path,
	const char type, unsigned long flags, void data)
	{
	return tomoyo_mount_permission(dev_name, path, type, flags, data);
	}

	/**
	* tomoyo_sb_umount - Target for security_sb_umount().
	*
	* @mnt: Pointer to "struct vfsmount".
	* @flags: Unmount options.
	*
	* Returns 0 on success, negative value otherwise.
	*/
	static int tomoyo_sb_umount(struct vfsmount *mnt, int flags)
	{
	struct path path = { .mnt = mnt, .dentry = mnt->mnt_root };
	return tomoyo_path_perm(TOMOYO_TYPE_UMOUNT, &path, NULL);
	}

	/**
	* tomoyo_sb_pivotroot - Target for security_sb_pivotroot().
	*
	* @old_path: Pointer to "struct path".
	* @new_path: Pointer to "struct path".
	*
	* Returns 0 on success, negative value otherwise.
	*/
	static int tomoyo_sb_pivotroot(const struct path old_path, const struct path new_path)
	{
	return tomoyo_path2_perm(TOMOYO_TYPE_PIVOT_ROOT, new_path, old_path);
	}

	/**
	* tomoyo_socket_listen - Check permission for listen().
	*
	* @sock: Pointer to "struct socket".
	* @backlog: Backlog parameter.
	*
	* Returns 0 on success, negative value otherwise.
	*/
	static int tomoyo_socket_listen(struct socket *sock, int backlog)
	{
	return tomoyo_socket_listen_permission(sock);
	}

	/**
	* tomoyo_socket_connect - Check permission for connect().
	*
	* @sock: Pointer to "struct socket".
	* @addr: Pointer to "struct sockaddr".
	* @addr_len: Size of @addr.
	*
	* Returns 0 on success, negative value otherwise.
	*/
	static int tomoyo_socket_connect(struct socket sock, struct sockaddr addr,
	int addr_len)
	{
	return tomoyo_socket_connect_permission(sock, addr, addr_len);
	}

	/**
	* tomoyo_socket_bind - Check permission for bind().
	*
	* @sock: Pointer to "struct socket".
	* @addr: Pointer to "struct sockaddr".
	* @addr_len: Size of @addr.
	*
	* Returns 0 on success, negative value otherwise.
	*/
	static int tomoyo_socket_bind(struct socket sock, struct sockaddr addr,
	int addr_len)
	{
	return tomoyo_socket_bind_permission(sock, addr, addr_len);
	}

	/**
	* tomoyo_socket_sendmsg - Check permission for sendmsg().
	*
	* @sock: Pointer to "struct socket".
	* @msg: Pointer to "struct msghdr".
	* @size: Size of message.
	*
	* Returns 0 on success, negative value otherwise.
	*/
	static int tomoyo_socket_sendmsg(struct socket sock, struct msghdr msg,
	int size)
	{
	return tomoyo_socket_sendmsg_permission(sock, msg, size);
	}

	/*
	* tomoyo_security_ops is a "struct security_operations" which is used for
	* registering TOMOYO.
	*/
	static struct security_hook_list tomoyo_hooks[] __lsm_ro_after_init = {
	LSM_HOOK_INIT(cred_alloc_blank, tomoyo_cred_alloc_blank),
	LSM_HOOK_INIT(cred_prepare, tomoyo_cred_prepare),
	LSM_HOOK_INIT(cred_transfer, tomoyo_cred_transfer),
	LSM_HOOK_INIT(cred_free, tomoyo_cred_free),
	LSM_HOOK_INIT(bprm_set_creds, tomoyo_bprm_set_creds),
	LSM_HOOK_INIT(bprm_check_security, tomoyo_bprm_check_security),
	LSM_HOOK_INIT(file_fcntl, tomoyo_file_fcntl),
	LSM_HOOK_INIT(file_open, tomoyo_file_open),
	LSM_HOOK_INIT(path_truncate, tomoyo_path_truncate),
	LSM_HOOK_INIT(path_unlink, tomoyo_path_unlink),
	LSM_HOOK_INIT(path_mkdir, tomoyo_path_mkdir),
	LSM_HOOK_INIT(path_rmdir, tomoyo_path_rmdir),
	LSM_HOOK_INIT(path_symlink, tomoyo_path_symlink),
	LSM_HOOK_INIT(path_mknod, tomoyo_path_mknod),
	LSM_HOOK_INIT(path_link, tomoyo_path_link),
	LSM_HOOK_INIT(path_rename, tomoyo_path_rename),
	LSM_HOOK_INIT(inode_getattr, tomoyo_inode_getattr),
	LSM_HOOK_INIT(file_ioctl, tomoyo_file_ioctl),
	LSM_HOOK_INIT(path_chmod, tomoyo_path_chmod),
	LSM_HOOK_INIT(path_chown, tomoyo_path_chown),
	LSM_HOOK_INIT(path_chroot, tomoyo_path_chroot),
	LSM_HOOK_INIT(sb_mount, tomoyo_sb_mount),
	LSM_HOOK_INIT(sb_umount, tomoyo_sb_umount),
	LSM_HOOK_INIT(sb_pivotroot, tomoyo_sb_pivotroot),
	LSM_HOOK_INIT(socket_bind, tomoyo_socket_bind),
	LSM_HOOK_INIT(socket_connect, tomoyo_socket_connect),
	LSM_HOOK_INIT(socket_listen, tomoyo_socket_listen),
	LSM_HOOK_INIT(socket_sendmsg, tomoyo_socket_sendmsg),
	};

	/* Lock for GC. */
	DEFINE_SRCU(tomoyo_ss);

	/**
	* tomoyo_init - Register TOMOYO Linux as a LSM module.
	*
	* Returns 0.
	*/
	static int __init tomoyo_init(void)
	{
	struct cred cred = (struct cred ) current_cred();

	if (!security_module_enable("tomoyo"))
	return 0;
	/* register ourselves with the security framework */
	security_add_hooks(tomoyo_hooks, ARRAY_SIZE(tomoyo_hooks), "tomoyo");
	printk(KERN_INFO "TOMOYO Linux initialized\n");
	cred->security = &tomoyo_kernel_domain;
	tomoyo_mm_init();
	return 0;
	}

	security_initcall(tomoyo_init);