Introduce vfs_suser(), used to test if a user should have special privs

for a mount.

2 files changed, 17 insertions, 0 deletions

diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c
index 1c7a7fb..40b564c 100644
--- a/sys/kern/vfs_subr.c
+++ b/sys/kern/vfs_subr.c
@@ -358,6 +358,22 @@ vfs_getvfs(fsid)
 }
 
 /*
+ * Check if a user can access priveledged mount options.
+ */
+int
+vfs_suser(struct mount *mp, struct thread *td)
+{
+	int error;
+
+	if ((mp->mnt_flag & MNT_USER) == 0 ||
+	    mp->mnt_cred->cr_uid != td->td_ucred->cr_uid) {
+		if ((error = suser(td)) != 0)
+			return (error);
+	}
+	return (0);
+}
+
+/*
  * Get a new unique fsid.  Try to make its val[0] unique, since this value
  * will be used to create fake device numbers for stat().  Also try (but
  * not so hard) make its val[0] unique mod 2^16, since some emulators only
diff --git a/sys/sys/mount.h b/sys/sys/mount.h
index 9e3afe6..3f8f098 100644
--- a/sys/sys/mount.h
+++ b/sys/sys/mount.h
@@ -578,6 +578,7 @@ int	vfs_mountedon(struct vnode *);    /* is a vfs mounted on vp */
 void	vfs_mountroot(void);			/* mount our root filesystem */
 int	vfs_rootmountalloc(char *, char *, struct mount **);
 void	vfs_mount_destroy(struct mount *, struct thread *);
+int	vfs_suser(struct mount *, struct thread *);
 void	vfs_unbusy(struct mount *, struct thread *);
 void	vfs_unmountall(void);
 int	vfs_register(struct vfsconf *);