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 --git a/security/dummy.c b/security/dummy.c
index 1c289598cc3dc7cbb3a815325dbf921a0c0ab02f..ce7f61be9b65b0d4744b8172ceb948c418afbc55 100644 (file)
--- a/security/dummy.c
+++ b/security/dummy.c
@@ -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 @@ static int dummy_sb_statfs (struct super_block *sb)
        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 @@ static int dummy_inode_getattr (struct vfsmount *mnt, struct dentry *dentry)
        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 @@ static void dummy_sem_free_security (struct sem_array *sma)
        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 @@ struct security_operations dummy_security_ops = {
        .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 @@ struct security_operations dummy_security_ops = {
        .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 @@ struct security_operations dummy_security_ops = {
        .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 --git a/security/security.c b/security/security.c
index 940f94181c991a65a246bd57f88abdfe70bc2ca9..3259b9980410015b97abd8904e85d752d44ba01a 100644 (file)
--- a/security/security.c
+++ b/security/security.c
@@ -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 security_scaffolding_startup (void)
  */
 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__);