/*
* security/tomoyo/tomoyo.c
*
* LSM hooks for TOMOYO Linux.
*
* Copyright (C) 2005-2009 NTT DATA CORPORATION
*
* Version: 2.2.0 2009/04/01
*
*/
#include <linux/security.h>
#include "common.h"
#include "tomoyo.h"
#include "realpath.h"
static int tomoyo_cred_alloc_blank(struct cred *new, gfp_t gfp)
{
new->security = NULL;
return 0;
}
static int tomoyo_cred_prepare(struct cred *new, const struct cred *old,
gfp_t gfp)
{
/*
* Since "struct tomoyo_domain_info *" is a sharable pointer,
* we don't need to duplicate.
*/
new->security = old->security;
return 0;
}
static void tomoyo_cred_transfer(struct cred *new, const struct cred *old)
{
/*
* Since "struct tomoyo_domain_info *" is a sharable pointer,
* we don't need to duplicate.
*/
new->security = old->security;
}
static int tomoyo_bprm_set_creds(struct linux_binprm *bprm)
{
int rc;
rc = cap_bprm_set_creds(bprm);
if (rc)
return rc;
/*
* Do only if this function is called for the first time of an execve
* operation.
*/
if (bprm->cred_prepared)
return 0;
/*
* 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);
/*
* Tell tomoyo_bprm_check_security() is called for the first time of an
* execve operation.
*/
bprm->cred->security = NULL;
return 0;
}
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) {
/*
* We will need to protect whole execve() operation when GC
* starts kfree()ing "struct tomoyo_domain_info" because
* bprm->cred->security points to "struct tomoyo_domain_info"
* but "struct tomoyo_domain_info" does not have a refcounter.
*/
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.
* '1' is the result of open_to_namei_flags(O_RDONLY).
*/
return tomoyo_check_open_permission(domain, &bprm->file->f_path, 1);
}
static int tomoyo_path_truncate(struct path *path, loff_t length,
unsigned int time_attrs)
{
return tomoyo_check_1path_perm(tomoyo_domain(),
TOMOYO_TYPE_TRUNCATE_ACL,
path);
}
static int tomoyo_path_unlink(struct path *parent, struct dentry *dentry)
{
struct path path = { parent->mnt, dentry };
return tomoyo_check_1path_perm(tomoyo_domain(),
TOMOYO_TYPE_UNLINK_ACL,
&path);
}
static int tomoyo_path_mkdir(struct path *parent, struct dentry *dentry,
int mode)
{
struct path path = { parent->mnt, dentry };
return tomoyo_check_1path_perm(tomoyo_domain(),
TOMOYO_TYPE_MKDIR_ACL,
&path);
}
static int tomoyo_path_rmdir(struct path *parent, struct dentry *dentry)
{
struct path path = { parent->mnt, dentry };
return tomoyo_check_1path_perm(tomoyo_domain(),
TOMOYO_TYPE_RMDIR_ACL,
&path);
}
static int tomoyo_path_symlink(struct path *parent, struct dentry *dentry,
const char *old_name)
{
struct path path = { parent->mnt, dentry };
return tomoyo_check_1path_perm(tomoyo_domain(),
TOMOYO_TYPE_SYMLINK_ACL,
&path);
}
static int tomoyo_path_mknod(struct path *parent, struct dentry *dentry,
int mode, unsigned int dev)
{
struct path path = { parent->mnt, dentry };
int type = TOMOYO_TYPE_CREATE_ACL;
switch (mode & S_IFMT) {
case S_IFCHR:
type = TOMOYO_TYPE_MKCHAR_ACL;
break;
case S_IFBLK:
type = TOMOYO_TYPE_MKBLOCK_ACL;
break;
case S_IFIFO:
type = TOMOYO_TYPE_MKFIFO_ACL;
break;
case S_IFSOCK:
type = TOMOYO_TYPE_MKSOCK_ACL;
break;
}
return tomoyo_check_1path_perm(tomoyo_domain(),
type, &path);
}
static int tomoyo_path_link(struct dentry *old_dentry, struct path *new_dir,
struct dentry *new_dentry)
{
struct path path1 = { new_dir->mnt, old_dentry };
struct path path2 = { new_dir->mnt, new_dentry };
return tomoyo_check_2path_perm(tomoyo_domain(),
TOMOYO_TYPE_LINK_ACL,
&path1, &path2);
}
static int tomoyo_path_rename(struct path *old_parent,
struct dentry *old_dentry,
struct path *new_parent,
struct dentry *new_dentry)
{
struct path path1 = { old_parent->mnt, old_dentry };
struct path path2 = { new_parent->mnt, new_dentry };
return tomoyo_check_2path_perm(tomoyo_domain(),
TOMOYO_TYPE_RENAME_ACL,
&path1, &path2);
}
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 tomoyo_check_rewrite_permission(tomoyo_domain(), file);
return 0;
}
static int tomoyo_dentry_open(struct file *f, const struct cred *cred)
{
int flags = f->f_flags;
if ((flags + 1) & O_ACCMODE)
flags++;
flags |= f->f_flags & (O_APPEND | O_TRUNC);
/* 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);
}
static int tomoyo_file_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
return tomoyo_check_1path_perm(tomoyo_domain(), TOMOYO_TYPE_IOCTL_ACL,
&file->f_path);
}
static int tomoyo_path_chmod(struct dentry *dentry, struct vfsmount *mnt,
mode_t mode)
{
struct path path = { mnt, dentry };
return tomoyo_check_1path_perm(tomoyo_domain(), TOMOYO_TYPE_CHMOD_ACL,
&path);
}
static int tomoyo_path_chown(struct path *path, uid_t uid, gid_t gid)
{
int error = 0;
if (uid != (uid_t) -1)
error = tomoyo_check_1path_perm(tomoyo_domain(),
TOMOYO_TYPE_CHOWN_ACL, path);
if (!error && gid != (gid_t) -1)
error = tomoyo_check_1path_perm(tomoyo_domain(),
TOMOYO_TYPE_CHGRP_ACL, path);
return error;
}
static int tomoyo_path_chroot(struct path *path)
{
return tomoyo_check_1path_perm(tomoyo_domain(), TOMOYO_TYPE_CHROOT_ACL,
path);
}
static int tomoyo_sb_mount(char *dev_name, struct path *path,
char *type, unsigned long flags, void *data)
{
return tomoyo_check_1path_perm(tomoyo_domain(), TOMOYO_TYPE_MOUNT_ACL,
path);
}
static int tomoyo_sb_umount(struct vfsmount *mnt, int flags)
{
struct path path = { mnt, mnt->mnt_root };
return tomoyo_check_1path_perm(tomoyo_domain(), TOMOYO_TYPE_UMOUNT_ACL,
&path);
}
static int tomoyo_sb_pivotroot(struct path *old_path, struct path *new_path)
{
return tomoyo_check_2path_perm(tomoyo_domain(),
TOMOYO_TYPE_PIVOT_ROOT_ACL,
new_path, old_path);
}
/*
* tomoyo_security_ops is a "struct security_operations" which is used for
* registering TOMOYO.
*/
static struct security_operations tomoyo_security_ops = {
.name = "tomoyo",
.cred_alloc_blank = tomoyo_cred_alloc_blank,
.cred_prepare = tomoyo_cred_prepare,
.cred_transfer = tomoyo_cred_transfer,
.bprm_set_creds = tomoyo_bprm_set_creds,
.bprm_check_security = tomoyo_bprm_check_security,
.file_fcntl = tomoyo_file_fcntl,
.dentry_open = tomoyo_dentry_open,
.path_truncate = tomoyo_path_truncate,
.path_unlink = tomoyo_path_unlink,
.path_mkdir = tomoyo_path_mkdir,
.path_rmdir = tomoyo_path_rmdir,
.path_symlink = tomoyo_path_symlink,
.path_mknod = tomoyo_path_mknod,
.path_link = tomoyo_path_link,
.path_rename = tomoyo_path_rename,
.file_ioctl = tomoyo_file_ioctl,
.path_chmod = tomoyo_path_chmod,
.path_chown = tomoyo_path_chown,
.path_chroot = tomoyo_path_chroot,
.sb_mount = tomoyo_sb_mount,
.sb_umount = tomoyo_sb_umount,
.sb_pivotroot = tomoyo_sb_pivotroot,
};
/* Lock for GC. */
struct srcu_struct tomoyo_ss;
static int __init tomoyo_init(void)
{
struct cred *cred = (struct cred *) current_cred();
if (!security_module_enable(&tomoyo_security_ops))
return 0;
/* register ourselves with the security framework */
if (register_security(&tomoyo_security_ops) ||
init_srcu_struct(&tomoyo_ss))
panic("Failure registering TOMOYO Linux");
printk(KERN_INFO "TOMOYO Linux initialized\n");
cred->security = &tomoyo_kernel_domain;
tomoyo_realpath_init();
return 0;
}
security_initcall(tomoyo_init);
