security/dummy.c

/*
 * Stub functions for the default security function pointers in case no
 * security model is loaded.
 *
 * Copyright (C) 2001 WireX Communications, Inc <chris@wirex.com>
 * Copyright (C) 2001 Greg Kroah-Hartman <greg@kroah.com>
 * Copyright (C) 2001 Networks Associates Technology, Inc <ssmalley@nai.com>
 *
 *	This program is free software; you can redistribute it and/or modify
 *	it under the terms of the GNU General Public License as published by
 *	the Free Software Foundation; either version 2 of the License, or
 *	(at your option) any later version.
 */

#undef DEBUG

#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/security.h>
#include <linux/skbuff.h>
#include <linux/netlink.h>


static int dummy_ptrace (struct task_struct *parent, struct task_struct *child)
{
	return 0;
}

static int dummy_capget (struct task_struct *target, kernel_cap_t * effective,
			 kernel_cap_t * inheritable, kernel_cap_t * permitted)
{
	*effective = *inheritable = *permitted = 0;
	if (!issecure(SECURE_NOROOT)) {
		if (target->euid == 0) {
			*permitted |= (~0 & ~CAP_FS_MASK);
			*effective |= (~0 & ~CAP_TO_MASK(CAP_SETPCAP) & ~CAP_FS_MASK);
		}
		if (target->fsuid == 0) {
			*permitted |= CAP_FS_MASK;
			*effective |= CAP_FS_MASK;
		}
	}
	return 0;
}

static int dummy_capset_check (struct task_struct *target,
			       kernel_cap_t * effective,
			       kernel_cap_t * inheritable,
			       kernel_cap_t * permitted)
{
	return -EPERM;
}

static void dummy_capset_set (struct task_struct *target,
			      kernel_cap_t * effective,
			      kernel_cap_t * inheritable,
			      kernel_cap_t * permitted)
{
	return;
}

static int dummy_acct (struct file *file)
{
	return 0;
}

static int dummy_capable (struct task_struct *tsk, int cap)
{
	if (cap_is_fs_cap (cap) ? tsk->fsuid == 0 : tsk->euid == 0)
		/* capability granted */
		return 0;

	/* capability denied */
	return -EPERM;
}

static int dummy_quotactl (int cmds, int type, int id, struct super_block *sb)
{
	return 0;
}

static int dummy_quota_on (struct file *f)
{
	return 0;
}

static int dummy_bprm_alloc_security (struct linux_binprm *bprm)
{
	return 0;
}

static void dummy_bprm_free_security (struct linux_binprm *bprm)
{
	return;
}

static void dummy_bprm_compute_creds (struct linux_binprm *bprm)
{
	return;
}

static int dummy_bprm_set_security (struct linux_binprm *bprm)
{
	return 0;
}

static int dummy_bprm_check_security (struct linux_binprm *bprm)
{
	return 0;
}

static int dummy_sb_alloc_security (struct super_block *sb)
{
	return 0;
}

static void dummy_sb_free_security (struct super_block *sb)
{
	return;
}

static int dummy_sb_statfs (struct super_block *sb)
{
	return 0;
}

static int dummy_sb_mount (char *dev_name, struct nameidata *nd, char *type,
			   unsigned long flags, void *data)
{
	return 0;
}

static int dummy_sb_check_sb (struct vfsmount *mnt, struct nameidata *nd)
{
	return 0;
}

static int dummy_sb_umount (struct vfsmount *mnt, int flags)
{
	return 0;
}

static void dummy_sb_umount_close (struct vfsmount *mnt)
{
	return;
}

static void dummy_sb_umount_busy (struct vfsmount *mnt)
{
	return;
}

static void dummy_sb_post_remount (struct vfsmount *mnt, unsigned long flags,
				   void *data)
{
	return;
}


static void dummy_sb_post_mountroot (void)
{
	return;
}

static void dummy_sb_post_addmount (struct vfsmount *mnt, struct nameidata *nd)
{
	return;
}

static int dummy_sb_pivotroot (struct nameidata *old_nd, struct nameidata *new_nd)
{
	return 0;
}

static void dummy_sb_post_pivotroot (struct nameidata *old_nd, struct nameidata *new_nd)
{
	return;
}

static int dummy_inode_alloc_security (struct inode *inode)
{
	return 0;
}

static void dummy_inode_free_security (struct inode *inode)
{
	return;
}

static int dummy_inode_create (struct inode *inode, struct dentry *dentry,
			       int mask)
{
	return 0;
}

static void dummy_inode_post_create (struct inode *inode, struct dentry *dentry,
				     int mask)
{
	return;
}

static int dummy_inode_link (struct dentry *old_dentry, struct inode *inode,
			     struct dentry *new_dentry)
{
	return 0;
}

static void dummy_inode_post_link (struct dentry *old_dentry,
				   struct inode *inode,
				   struct dentry *new_dentry)
{
	return;
}

static int dummy_inode_unlink (struct inode *inode, struct dentry *dentry)
{
	return 0;
}

static int dummy_inode_symlink (struct inode *inode, struct dentry *dentry,
				const char *name)
{
	return 0;
}

static void dummy_inode_post_symlink (struct inode *inode,
				      struct dentry *dentry, const char *name)
{
	return;
}

static int dummy_inode_mkdir (struct inode *inode, struct dentry *dentry,
			      int mask)
{
	return 0;
}

static void dummy_inode_post_mkdir (struct inode *inode, struct dentry *dentry,
				    int mask)
{
	return;
}

static int dummy_inode_rmdir (struct inode *inode, struct dentry *dentry)
{
	return 0;
}

static int dummy_inode_mknod (struct inode *inode, struct dentry *dentry,
			      int mode, dev_t dev)
{
	return 0;
}

static void dummy_inode_post_mknod (struct inode *inode, struct dentry *dentry,
				    int mode, dev_t dev)
{
	return;
}

static int dummy_inode_rename (struct inode *old_inode,
			       struct dentry *old_dentry,
			       struct inode *new_inode,
			       struct dentry *new_dentry)
{
	return 0;
}

static void dummy_inode_post_rename (struct inode *old_inode,
				     struct dentry *old_dentry,
				     struct inode *new_inode,
				     struct dentry *new_dentry)
{
	return;
}

static int dummy_inode_readlink (struct dentry *dentry)
{
	return 0;
}

static int dummy_inode_follow_link (struct dentry *dentry,
				    struct nameidata *nameidata)
{
	return 0;
}

static int dummy_inode_permission (struct inode *inode, int mask)
{
	return 0;
}

static int dummy_inode_permission_lite (struct inode *inode, int mask)
{
	return 0;
}

static int dummy_inode_setattr (struct dentry *dentry, struct iattr *iattr)
{
	return 0;
}

static int dummy_inode_getattr (struct vfsmount *mnt, struct dentry *dentry)
{
	return 0;
}

static void dummy_inode_post_lookup (struct inode *ino, struct dentry *d)
{
	return;
}

static void dummy_inode_delete (struct inode *ino)
{
	return;
}

static int dummy_inode_setxattr (struct dentry *dentry, char *name, void *value,
				size_t size, int flags)
{
	return 0;
}

static int dummy_inode_getxattr (struct dentry *dentry, char *name)
{
	return 0;
}

static int dummy_inode_listxattr (struct dentry *dentry)
{
	return 0;
}

static int dummy_inode_removexattr (struct dentry *dentry, char *name)
{
	return 0;
}

static int dummy_file_permission (struct file *file, int mask)
{
	return 0;
}

static int dummy_file_alloc_security (struct file *file)
{
	return 0;
}

static void dummy_file_free_security (struct file *file)
{
	return;
}

static int dummy_file_ioctl (struct file *file, unsigned int command,
			     unsigned long arg)
{
	return 0;
}

static int dummy_file_mmap (struct file *file, unsigned long prot,
			    unsigned long flags)
{
	return 0;
}

static int dummy_file_mprotect (struct vm_area_struct *vma, unsigned long prot)
{
	return 0;
}

static int dummy_file_lock (struct file *file, unsigned int cmd)
{
	return 0;
}

static int dummy_file_fcntl (struct file *file, unsigned int cmd,
			     unsigned long arg)
{
	return 0;
}

static int dummy_file_set_fowner (struct file *file)
{
	return 0;
}

static int dummy_file_send_sigiotask (struct task_struct *tsk,
				      struct fown_struct *fown, int fd,
				      int reason)
{
	return 0;
}

static int dummy_file_receive (struct file *file)
{
	return 0;
}

static int dummy_task_create (unsigned long clone_flags)
{
	return 0;
}

static int dummy_task_alloc_security (struct task_struct *p)
{
	return 0;
}

static void dummy_task_free_security (struct task_struct *p)
{
	return;
}

static int dummy_task_setuid (uid_t id0, uid_t id1, uid_t id2, int flags)
{
	return 0;
}

static int dummy_task_post_setuid (uid_t id0, uid_t id1, uid_t id2, int flags)
{
	return 0;
}

static int dummy_task_setgid (gid_t id0, gid_t id1, gid_t id2, int flags)
{
	return 0;
}

static int dummy_task_setpgid (struct task_struct *p, pid_t pgid)
{
	return 0;
}

static int dummy_task_getpgid (struct task_struct *p)
{
	return 0;
}

static int dummy_task_getsid (struct task_struct *p)
{
	return 0;
}

static int dummy_task_setgroups (int gidsetsize, gid_t * grouplist)
{
	return 0;
}

static int dummy_task_setnice (struct task_struct *p, int nice)
{
	return 0;
}

static int dummy_task_setrlimit (unsigned int resource, struct rlimit *new_rlim)
{
	return 0;
}

static int dummy_task_setscheduler (struct task_struct *p, int policy,
				    struct sched_param *lp)
{
	return 0;
}

static int dummy_task_getscheduler (struct task_struct *p)
{
	return 0;
}

static int dummy_task_wait (struct task_struct *p)
{
	return 0;
}

static int dummy_task_kill (struct task_struct *p, struct siginfo *info,
			    int sig)
{
	return 0;
}

static int dummy_task_prctl (int option, unsigned long arg2, unsigned long arg3,
			     unsigned long arg4, unsigned long arg5)
{
	return 0;
}

static void dummy_task_kmod_set_label (void)
{
	return;
}

static void dummy_task_reparent_to_init (struct task_struct *p)
{
	p->euid = p->fsuid = 0;
	return;
}

static int dummy_ipc_permission (struct kern_ipc_perm *ipcp, short flag)
{
	return 0;
}


static int dummy_msg_queue_alloc_security (struct msg_queue *msq)
{
	return 0;
}

static void dummy_msg_queue_free_security (struct msg_queue *msq)
{
	return;
}

static int dummy_shm_alloc_security (struct shmid_kernel *shp)
{
	return 0;
}

static void dummy_shm_free_security (struct shmid_kernel *shp)
{
	return;
}

static int dummy_sem_alloc_security (struct sem_array *sma)
{
	return 0;
}

static void dummy_sem_free_security (struct sem_array *sma)
{
	return;
}

static int dummy_register_security (const char *name, struct security_operations *ops)
{
	return -EINVAL;
}

static int dummy_unregister_security (const char *name, struct security_operations *ops)
{
	return -EINVAL;
}

struct security_operations dummy_security_ops = {
	.ptrace =			dummy_ptrace,
	.capget =			dummy_capget,
	.capset_check =			dummy_capset_check,
	.capset_set =			dummy_capset_set,
	.acct =				dummy_acct,
	.capable =			dummy_capable,
	.quotactl =			dummy_quotactl,
	.quota_on =			dummy_quota_on,

	.bprm_alloc_security =		dummy_bprm_alloc_security,
	.bprm_free_security =		dummy_bprm_free_security,
	.bprm_compute_creds =		dummy_bprm_compute_creds,
	.bprm_set_security =		dummy_bprm_set_security,
	.bprm_check_security =		dummy_bprm_check_security,

	.sb_alloc_security =		dummy_sb_alloc_security,
	.sb_free_security =		dummy_sb_free_security,
	.sb_statfs =			dummy_sb_statfs,
	.sb_mount =			dummy_sb_mount,
	.sb_check_sb =			dummy_sb_check_sb,
	.sb_umount =			dummy_sb_umount,
	.sb_umount_close =		dummy_sb_umount_close,
	.sb_umount_busy =		dummy_sb_umount_busy,
	.sb_post_remount =		dummy_sb_post_remount,
	.sb_post_mountroot =		dummy_sb_post_mountroot,
	.sb_post_addmount =		dummy_sb_post_addmount,
	.sb_pivotroot =			dummy_sb_pivotroot,
	.sb_post_pivotroot =		dummy_sb_post_pivotroot,
	
	.inode_alloc_security =		dummy_inode_alloc_security,
	.inode_free_security =		dummy_inode_free_security,
	.inode_create =			dummy_inode_create,
	.inode_post_create =		dummy_inode_post_create,
	.inode_link =			dummy_inode_link,
	.inode_post_link =		dummy_inode_post_link,
	.inode_unlink =			dummy_inode_unlink,
	.inode_symlink =		dummy_inode_symlink,
	.inode_post_symlink =		dummy_inode_post_symlink,
	.inode_mkdir =			dummy_inode_mkdir,
	.inode_post_mkdir =		dummy_inode_post_mkdir,
	.inode_rmdir =			dummy_inode_rmdir,
	.inode_mknod =			dummy_inode_mknod,
	.inode_post_mknod =		dummy_inode_post_mknod,
	.inode_rename =			dummy_inode_rename,
	.inode_post_rename =		dummy_inode_post_rename,
	.inode_readlink =		dummy_inode_readlink,
	.inode_follow_link =		dummy_inode_follow_link,
	.inode_permission =		dummy_inode_permission,
	.inode_permission_lite =	dummy_inode_permission_lite,
	.inode_setattr =		dummy_inode_setattr,
	.inode_getattr =		dummy_inode_getattr,
	.inode_post_lookup =		dummy_inode_post_lookup,
	.inode_delete =			dummy_inode_delete,
	.inode_setxattr =		dummy_inode_setxattr,
	.inode_getxattr =		dummy_inode_getxattr,
	.inode_listxattr =		dummy_inode_listxattr,
	.inode_removexattr =		dummy_inode_removexattr,

	.file_permission =		dummy_file_permission,
	.file_alloc_security =		dummy_file_alloc_security,
	.file_free_security =		dummy_file_free_security,
	.file_ioctl =			dummy_file_ioctl,
	.file_mmap =			dummy_file_mmap,
	.file_mprotect =		dummy_file_mprotect,
	.file_lock =			dummy_file_lock,
	.file_fcntl =			dummy_file_fcntl,
	.file_set_fowner =		dummy_file_set_fowner,
	.file_send_sigiotask =		dummy_file_send_sigiotask,
	.file_receive =			dummy_file_receive,

	.task_create =			dummy_task_create,
	.task_alloc_security =		dummy_task_alloc_security,
	.task_free_security =		dummy_task_free_security,
	.task_setuid =			dummy_task_setuid,
	.task_post_setuid =		dummy_task_post_setuid,
	.task_setgid =			dummy_task_setgid,
	.task_setpgid =			dummy_task_setpgid,
	.task_getpgid =			dummy_task_getpgid,
	.task_getsid =			dummy_task_getsid,
	.task_setgroups =		dummy_task_setgroups,
	.task_setnice =			dummy_task_setnice,
	.task_setrlimit =		dummy_task_setrlimit,
	.task_setscheduler =		dummy_task_setscheduler,
	.task_getscheduler =		dummy_task_getscheduler,
	.task_wait =			dummy_task_wait,
	.task_kill =			dummy_task_kill,
	.task_prctl =			dummy_task_prctl,
	.task_kmod_set_label =		dummy_task_kmod_set_label,
	.task_reparent_to_init =	dummy_task_reparent_to_init,

	.ipc_permission =		dummy_ipc_permission,
	
	.msg_queue_alloc_security =	dummy_msg_queue_alloc_security,
	.msg_queue_free_security =	dummy_msg_queue_free_security,
	
	.shm_alloc_security =		dummy_shm_alloc_security,
	.shm_free_security =		dummy_shm_free_security,
	
	.sem_alloc_security =		dummy_sem_alloc_security,
	.sem_free_security =		dummy_sem_free_security,

	.register_security =		dummy_register_security,
	.unregister_security =		dummy_unregister_security,
};

#define set_to_dummy_if_null(ops, function)				\
	do {								\
		if (!ops->function) {					\
			ops->function = dummy_##function;		\
			pr_debug("Had to override the " #function	\
				 " security operation with the dummy one.\n");\
			}						\
	} while (0)

void security_fixup_ops (struct security_operations *ops)
{
	set_to_dummy_if_null(ops, ptrace);
	set_to_dummy_if_null(ops, capget);
	set_to_dummy_if_null(ops, capset_check);
	set_to_dummy_if_null(ops, capset_set);
	set_to_dummy_if_null(ops, acct);
	set_to_dummy_if_null(ops, capable);
	set_to_dummy_if_null(ops, quotactl);
	set_to_dummy_if_null(ops, quota_on);
	set_to_dummy_if_null(ops, bprm_alloc_security);
	set_to_dummy_if_null(ops, bprm_free_security);
	set_to_dummy_if_null(ops, bprm_compute_creds);
	set_to_dummy_if_null(ops, bprm_set_security);
	set_to_dummy_if_null(ops, bprm_check_security);
	set_to_dummy_if_null(ops, sb_alloc_security);
	set_to_dummy_if_null(ops, sb_free_security);
	set_to_dummy_if_null(ops, sb_statfs);
	set_to_dummy_if_null(ops, sb_mount);
	set_to_dummy_if_null(ops, sb_check_sb);
	set_to_dummy_if_null(ops, sb_umount);
	set_to_dummy_if_null(ops, sb_umount_close);
	set_to_dummy_if_null(ops, sb_umount_busy);
	set_to_dummy_if_null(ops, sb_post_remount);
	set_to_dummy_if_null(ops, sb_post_mountroot);
	set_to_dummy_if_null(ops, sb_post_addmount);
	set_to_dummy_if_null(ops, sb_pivotroot);
	set_to_dummy_if_null(ops, sb_post_pivotroot);
	set_to_dummy_if_null(ops, inode_alloc_security);
	set_to_dummy_if_null(ops, inode_free_security);
	set_to_dummy_if_null(ops, inode_create);
	set_to_dummy_if_null(ops, inode_post_create);
	set_to_dummy_if_null(ops, inode_link);
	set_to_dummy_if_null(ops, inode_post_link);
	set_to_dummy_if_null(ops, inode_unlink);
	set_to_dummy_if_null(ops, inode_symlink);
	set_to_dummy_if_null(ops, inode_post_symlink);
	set_to_dummy_if_null(ops, inode_mkdir);
	set_to_dummy_if_null(ops, inode_post_mkdir);
	set_to_dummy_if_null(ops, inode_rmdir);
	set_to_dummy_if_null(ops, inode_mknod);
	set_to_dummy_if_null(ops, inode_post_mknod);
	set_to_dummy_if_null(ops, inode_rename);
	set_to_dummy_if_null(ops, inode_post_rename);
	set_to_dummy_if_null(ops, inode_readlink);
	set_to_dummy_if_null(ops, inode_follow_link);
	set_to_dummy_if_null(ops, inode_permission);
	set_to_dummy_if_null(ops, inode_permission_lite);
	set_to_dummy_if_null(ops, inode_setattr);
	set_to_dummy_if_null(ops, inode_getattr);
	set_to_dummy_if_null(ops, inode_post_lookup);
	set_to_dummy_if_null(ops, inode_delete);
	set_to_dummy_if_null(ops, inode_setxattr);
	set_to_dummy_if_null(ops, inode_getxattr);
	set_to_dummy_if_null(ops, inode_listxattr);
	set_to_dummy_if_null(ops, inode_removexattr);
	set_to_dummy_if_null(ops, file_permission);
	set_to_dummy_if_null(ops, file_alloc_security);
	set_to_dummy_if_null(ops, file_free_security);
	set_to_dummy_if_null(ops, file_ioctl);
	set_to_dummy_if_null(ops, file_mmap);
	set_to_dummy_if_null(ops, file_mprotect);
	set_to_dummy_if_null(ops, file_lock);
	set_to_dummy_if_null(ops, file_fcntl);
	set_to_dummy_if_null(ops, file_set_fowner);
	set_to_dummy_if_null(ops, file_send_sigiotask);
	set_to_dummy_if_null(ops, file_receive);
	set_to_dummy_if_null(ops, task_create);
	set_to_dummy_if_null(ops, task_alloc_security);
	set_to_dummy_if_null(ops, task_free_security);
	set_to_dummy_if_null(ops, task_setuid);
	set_to_dummy_if_null(ops, task_post_setuid);
	set_to_dummy_if_null(ops, task_setgid);
	set_to_dummy_if_null(ops, task_setpgid);
	set_to_dummy_if_null(ops, task_getpgid);
	set_to_dummy_if_null(ops, task_getsid);
	set_to_dummy_if_null(ops, task_setgroups);
	set_to_dummy_if_null(ops, task_setnice);
	set_to_dummy_if_null(ops, task_setrlimit);
	set_to_dummy_if_null(ops, task_setscheduler);
	set_to_dummy_if_null(ops, task_getscheduler);
	set_to_dummy_if_null(ops, task_wait);
	set_to_dummy_if_null(ops, task_kill);
	set_to_dummy_if_null(ops, task_prctl);
	set_to_dummy_if_null(ops, task_kmod_set_label);
	set_to_dummy_if_null(ops, task_reparent_to_init);
	set_to_dummy_if_null(ops, ipc_permission);
	set_to_dummy_if_null(ops, msg_queue_alloc_security);
	set_to_dummy_if_null(ops, msg_queue_free_security);
	set_to_dummy_if_null(ops, shm_alloc_security);
	set_to_dummy_if_null(ops, shm_free_security);
	set_to_dummy_if_null(ops, sem_alloc_security);
	set_to_dummy_if_null(ops, sem_free_security);
	set_to_dummy_if_null(ops, register_security);
	set_to_dummy_if_null(ops, unregister_security);
}