Re: [PATCH] LSM changes for 2.5.50

From: Greg KH (gregat_private)
Date: Thu Dec 05 2002 - 08:33:39 PST

  • Next message: Greg KH: "Re: [PATCH] LSM changes for 2.5.50"

    ChangeSet 1.797.142.2, 2002/12/04 16:01:47-06:00, gregat_private
    
    LSM: Added security_fixup_ops()
    
    This allows LSM code to only define the functions that they want to,
    and not be forced to provide "dummy" functions for everything else.
    
    
    diff -Nru a/security/dummy.c b/security/dummy.c
    --- a/security/dummy.c	Thu Dec  5 01:19:17 2002
    +++ b/security/dummy.c	Thu Dec  5 01:19:17 2002
    @@ -12,6 +12,8 @@
      *	(at your option) any later version.
      */
     
    +#undef DEBUG
    +
     #include <linux/config.h>
     #include <linux/module.h>
     #include <linux/kernel.h>
    @@ -19,6 +21,7 @@
     #include <linux/skbuff.h>
     #include <linux/netlink.h>
     
    +
     static int dummy_ptrace (struct task_struct *parent, struct task_struct *child)
     {
     	return 0;
    @@ -122,55 +125,55 @@
     	return 0;
     }
     
    -static int dummy_mount (char *dev_name, struct nameidata *nd, char *type,
    -			unsigned long flags, void *data)
    +static int dummy_sb_mount (char *dev_name, struct nameidata *nd, char *type,
    +			   unsigned long flags, void *data)
     {
     	return 0;
     }
     
    -static int dummy_check_sb (struct vfsmount *mnt, struct nameidata *nd)
    +static int dummy_sb_check_sb (struct vfsmount *mnt, struct nameidata *nd)
     {
     	return 0;
     }
     
    -static int dummy_umount (struct vfsmount *mnt, int flags)
    +static int dummy_sb_umount (struct vfsmount *mnt, int flags)
     {
     	return 0;
     }
     
    -static void dummy_umount_close (struct vfsmount *mnt)
    +static void dummy_sb_umount_close (struct vfsmount *mnt)
     {
     	return;
     }
     
    -static void dummy_umount_busy (struct vfsmount *mnt)
    +static void dummy_sb_umount_busy (struct vfsmount *mnt)
     {
     	return;
     }
     
    -static void dummy_post_remount (struct vfsmount *mnt, unsigned long flags,
    -				void *data)
    +static void dummy_sb_post_remount (struct vfsmount *mnt, unsigned long flags,
    +				   void *data)
     {
     	return;
     }
     
     
    -static void dummy_post_mountroot (void)
    +static void dummy_sb_post_mountroot (void)
     {
     	return;
     }
     
    -static void dummy_post_addmount (struct vfsmount *mnt, struct nameidata *nd)
    +static void dummy_sb_post_addmount (struct vfsmount *mnt, struct nameidata *nd)
     {
     	return;
     }
     
    -static int dummy_pivotroot (struct nameidata *old_nd, struct nameidata *new_nd)
    +static int dummy_sb_pivotroot (struct nameidata *old_nd, struct nameidata *new_nd)
     {
     	return 0;
     }
     
    -static void dummy_post_pivotroot (struct nameidata *old_nd, struct nameidata *new_nd)
    +static void dummy_sb_post_pivotroot (struct nameidata *old_nd, struct nameidata *new_nd)
     {
     	return;
     }
    @@ -303,12 +306,12 @@
     	return 0;
     }
     
    -static void dummy_post_lookup (struct inode *ino, struct dentry *d)
    +static void dummy_inode_post_lookup (struct inode *ino, struct dentry *d)
     {
     	return;
     }
     
    -static void dummy_delete (struct inode *ino)
    +static void dummy_inode_delete (struct inode *ino)
     {
     	return;
     }
    @@ -529,12 +532,12 @@
     	return;
     }
     
    -static int dummy_register (const char *name, struct security_operations *ops)
    +static int dummy_register_security (const char *name, struct security_operations *ops)
     {
     	return -EINVAL;
     }
     
    -static int dummy_unregister (const char *name, struct security_operations *ops)
    +static int dummy_unregister_security (const char *name, struct security_operations *ops)
     {
     	return -EINVAL;
     }
    @@ -558,16 +561,16 @@
     	.sb_alloc_security =		dummy_sb_alloc_security,
     	.sb_free_security =		dummy_sb_free_security,
     	.sb_statfs =			dummy_sb_statfs,
    -	.sb_mount =			dummy_mount,
    -	.sb_check_sb =			dummy_check_sb,
    -	.sb_umount =			dummy_umount,
    -	.sb_umount_close =		dummy_umount_close,
    -	.sb_umount_busy =		dummy_umount_busy,
    -	.sb_post_remount =		dummy_post_remount,
    -	.sb_post_mountroot =		dummy_post_mountroot,
    -	.sb_post_addmount =		dummy_post_addmount,
    -	.sb_pivotroot =			dummy_pivotroot,
    -	.sb_post_pivotroot =		dummy_post_pivotroot,
    +	.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,
    @@ -591,8 +594,8 @@
     	.inode_permission_lite =	dummy_inode_permission_lite,
     	.inode_setattr =		dummy_inode_setattr,
     	.inode_getattr =		dummy_inode_getattr,
    -	.inode_post_lookup =		dummy_post_lookup,
    -	.inode_delete =			dummy_delete,
    +	.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,
    @@ -641,7 +644,113 @@
     	.sem_alloc_security =		dummy_sem_alloc_security,
     	.sem_free_security =		dummy_sem_free_security,
     
    -	.register_security =		dummy_register,
    -	.unregister_security =		dummy_unregister,
    +	.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);
    +}
     
    diff -Nru a/security/security.c b/security/security.c
    --- a/security/security.c	Thu Dec  5 01:19:17 2002
    +++ b/security/security.c	Thu Dec  5 01:19:17 2002
    @@ -20,59 +20,21 @@
     
     #define SECURITY_SCAFFOLD_VERSION	"1.0.0"
     
    -extern struct security_operations dummy_security_ops;	/* lives in dummy.c */
    +/* things that live in dummy.c */
    +extern struct security_operations dummy_security_ops;
    +extern void security_fixup_ops (struct security_operations *ops);
     
     struct security_operations *security_ops;	/* Initialized to NULL */
     
    -/* This macro checks that all pointers in a struct are non-NULL.  It 
    - * can be fooled by struct padding for object tile alignment and when
    - * pointers to data and pointers to functions aren't the same size.
    - * Yes it's ugly, we'll replace it if it becomes a problem.
    - */
    -#define VERIFY_STRUCT(struct_type, s, e) \
    -	do { \
    -		unsigned long * __start = (unsigned long *)(s); \
    -		unsigned long * __end = __start + \
    -				sizeof(struct_type)/sizeof(unsigned long *); \
    -		while (__start != __end) { \
    -			if (!*__start) { \
    -				printk(KERN_INFO "%s is missing something\n",\
    -					#struct_type); \
    -				e++; \
    -				break; \
    -			} \
    -			__start++; \
    -		} \
    -	} while (0)
    -
    -static int inline verify (struct security_operations *ops)
    +static inline int verify (struct security_operations *ops)
     {
    -	int err;
    -
     	/* verify the security_operations structure exists */
     	if (!ops) {
     		printk (KERN_INFO "Passed a NULL security_operations "
     			"pointer, %s failed.\n", __FUNCTION__);
     		return -EINVAL;
     	}
    -
    -	/* Perform a little sanity checking on our inputs */
    -	err = 0;
    -
    -	/* This first check scans the whole security_ops struct for
    -	 * missing structs or functions.
    -	 *
    -	 * (There is no further check now, but will leave as is until
    -	 *  the lazy registration stuff is done -- JM).
    -	 */
    -	VERIFY_STRUCT(struct security_operations, ops, err);
    -
    -	if (err) {
    -		printk (KERN_INFO "Not enough functions specified in the "
    -			"security_operation structure, %s failed.\n",
    -			__FUNCTION__);
    -		return -EINVAL;
    -	}
    +	security_fixup_ops (ops);
     	return 0;
     }
     
    @@ -106,12 +68,12 @@
      */
     int register_security (struct security_operations *ops)
     {
    -
     	if (verify (ops)) {
     		printk (KERN_INFO "%s could not verify "
     			"security_operations structure.\n", __FUNCTION__);
     		return -EINVAL;
     	}
    +
     	if (security_ops != &dummy_security_ops) {
     		printk (KERN_INFO "There is already a security "
     			"framework initialized, %s failed.\n", __FUNCTION__);
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