OK!

Finally the cascaded VFS patch is in.
Testing is very welcome, specially with layered multiple vfs modules.
A big thank to Alexander Bokovoy for his work and patience :)

Simo.
(This used to be commit 56283601afe1836dafe0580532f014e29593c463)

1 files changed, 199 insertions, 2 deletions

diff --git a/source3/include/vfs.h b/source3/include/vfs.h
index 2f9fedf77d..1b1a13d7c1 100644
--- a/source3/include/vfs.h
+++ b/source3/include/vfs.h
@@ -1,7 +1,8 @@
 /* 
    Unix SMB/CIFS implementation.
    VFS structures and parameters
-   Copyright (C) Tim Potter 1999
+   Copyright (C) Tim Potter				1999
+   Copyright (C) Alexander Bokovoy			2002
    
    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
@@ -16,6 +17,8 @@
    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+   This work was sponsored by Optifacio Software Services, Inc.
 */
 
 #ifndef _VFS_H
@@ -40,7 +43,48 @@
 
 /* Changed to version 2 for CIFS UNIX extensions (mknod and link added). JRA. */
 /* Changed to version 3 for POSIX acl extensions. JRA. */
-#define SMB_VFS_INTERFACE_VERSION 3
+/* Changed to version 4 for cascaded VFS interface. Alexander Bokovoy. */
+#define SMB_VFS_INTERFACE_VERSION 5
+
+
+/* Version of supported cascaded interface backward copmatibility.
+   (version 4 corresponds to SMB_VFS_INTERFACE_VERSION 4)
+   It is used in vfs_init_custom() to detect VFS modules which conform to cascaded 
+   VFS interface but implement elder version than current version of Samba uses.
+   This allows to use old modules with new VFS interface as far as combined VFS operation
+   set is coherent (will be in most cases). 
+*/
+#define SMB_VFS_INTERFACE_CASCADED 4
+
+/*
+    Each VFS module must provide following global functions:
+    vfs_init	-- initialization function
+    vfs_done	-- finalization function
+    
+    vfs_init must return proper initialized vfs_op_tuple[] array
+    which describes all operations this module claims to intercept. This function
+    is called whenever module is loaded into smbd process using sys_dlopen().
+    
+    vfs_init must store somewhere vfs_handle reference if module wants to store per-instance
+    private information for further usage. vfs_handle->data should be used to
+    store such information. Do not try to change other fields in this structure
+    or results likely to be unpredictable.
+    
+    vfs_done must perform finalization of the module. In particular,
+    this function must free vfs_ops structure returned to module from smb_vfs_get_opaque_ops()
+    function if it is used (see below). This function is called whenever module 
+    is unloaded from smbd process using sys_dlclose().
+    
+    Prototypes:
+    vfs_op_tuple *vfs_init(int *vfs_version, const struct vfs_ops *def_vfs_ops,
+			    struct smb_vfs_handle_struct *vfs_handle);
+    void	  vfs_done(connection_struct *conn);
+    
+    All intercepted VFS operations must be declared as static functions inside module source
+    in order to keep smbd namespace unpolluted. See source of skel, audit, and recycle bin
+    example VFS modules for more details.
+    
+*/
 
 /* VFS operations structure */
 
@@ -135,4 +179,157 @@ struct vfs_options {
     char *value;
 };
 
+/*
+    Available VFS operations. These values must be in sync with vfs_ops struct.
+    In particular, if new operations are added to vfs_ops, appropriate constants
+    should be added to vfs_op_type so that order of them kept same as in vfs_ops.
+*/
+
+typedef enum _vfs_op_type {
+
+	SMB_VFS_OP_NOOP = -1,
+	
+	/* Disk operations */
+
+	SMB_VFS_OP_CONNECT = 0,
+	SMB_VFS_OP_DISCONNECT,
+	SMB_VFS_OP_DISK_FREE,
+
+	/* Directory operations */
+
+	SMB_VFS_OP_OPENDIR,
+	SMB_VFS_OP_READDIR,
+	SMB_VFS_OP_MKDIR,
+	SMB_VFS_OP_RMDIR,
+	SMB_VFS_OP_CLOSEDIR,
+
+	/* File operations */
+
+	SMB_VFS_OP_OPEN,
+	SMB_VFS_OP_CLOSE,
+	SMB_VFS_OP_READ,
+	SMB_VFS_OP_WRITE,
+	SMB_VFS_OP_LSEEK,
+	SMB_VFS_OP_RENAME,
+	SMB_VFS_OP_FSYNC,
+	SMB_VFS_OP_STAT,
+	SMB_VFS_OP_FSTAT,
+	SMB_VFS_OP_LSTAT,
+	SMB_VFS_OP_UNLINK,
+	SMB_VFS_OP_CHMOD,
+	SMB_VFS_OP_FCHMOD,
+	SMB_VFS_OP_CHOWN,
+	SMB_VFS_OP_FCHOWN,
+	SMB_VFS_OP_CHDIR,
+	SMB_VFS_OP_GETWD,
+	SMB_VFS_OP_UTIME,
+	SMB_VFS_OP_FTRUNCATE,
+	SMB_VFS_OP_LOCK,
+	SMB_VFS_OP_SYMLINK,
+	SMB_VFS_OP_READLINK,
+	SMB_VFS_OP_LINK,
+	SMB_VFS_OP_MKNOD,
+	SMB_VFS_OP_REALPATH,
+
+	/* NT ACL operations. */
+
+	SMB_VFS_OP_FGET_NT_ACL,
+	SMB_VFS_OP_GET_NT_ACL,
+	SMB_VFS_OP_FSET_NT_ACL,
+	SMB_VFS_OP_SET_NT_ACL,
+
+	/* POSIX ACL operations. */
+
+	SMB_VFS_OP_CHMOD_ACL,
+	SMB_VFS_OP_FCHMOD_ACL,
+
+	SMB_VFS_OP_SYS_ACL_GET_ENTRY,
+	SMB_VFS_OP_SYS_ACL_GET_TAG_TYPE,
+	SMB_VFS_OP_SYS_ACL_GET_PERMSET,
+	SMB_VFS_OP_SYS_ACL_GET_QUALIFIER,
+	SMB_VFS_OP_SYS_ACL_GET_FILE,
+	SMB_VFS_OP_SYS_ACL_GET_FD,
+	SMB_VFS_OP_SYS_ACL_CLEAR_PERMS,
+	SMB_VFS_OP_SYS_ACL_ADD_PERM,
+	SMB_VFS_OP_SYS_ACL_TO_TEXT,
+	SMB_VFS_OP_SYS_ACL_INIT,
+	SMB_VFS_OP_SYS_ACL_CREATE_ENTRY,
+	SMB_VFS_OP_SYS_ACL_SET_TAG_TYPE,
+	SMB_VFS_OP_SYS_ACL_SET_QUALIFIER,
+	SMB_VFS_OP_SYS_ACL_SET_PERMSET,
+	SMB_VFS_OP_SYS_ACL_VALID,
+	SMB_VFS_OP_SYS_ACL_SET_FILE,
+	SMB_VFS_OP_SYS_ACL_SET_FD,
+	SMB_VFS_OP_SYS_ACL_DELETE_DEF_FILE,
+	SMB_VFS_OP_SYS_ACL_GET_PERM,
+	SMB_VFS_OP_SYS_ACL_FREE_TEXT,
+	SMB_VFS_OP_SYS_ACL_FREE_ACL,
+	SMB_VFS_OP_SYS_ACL_FREE_QUALIFIER,
+	
+	/* This should always be last enum value */
+	
+	SMB_VFS_OP_LAST
+} vfs_op_type;
+
+/*
+    Possible VFS operation layers (per-operation)
+    
+    These values are used by VFS subsystem when building vfs_ops for connection
+    from multiple VFS modules. Internally, Samba differentiates only opaque and
+    transparent layers at this process. Other types are used for providing better
+    diagnosing facilities.
+    
+    Most modules will provide transparent layers. Opaque layer is for modules
+    which implement actual file system calls (like DB-based VFS). For example,
+    default POSIX VFS which is built in into Samba is an opaque VFS module.
+    
+    Other layer types (audit, splitter, scanner) were designed to provide different 
+    degree of transparency and for diagnosing VFS module behaviour.
+    
+    Each module can implement several layers at the same time provided that only
+    one layer is used per each operation.
+    
+*/
+
+typedef enum _vfs_op_layer {
+	SMB_VFS_LAYER_NOOP = -1,	/* - For using in VFS module to indicate end of array */
+					/*   of operations description */
+	SMB_VFS_LAYER_OPAQUE = 0,	/* - Final level, does not call anything beyond itself */
+	SMB_VFS_LAYER_TRANSPARENT,	/* - Normal operation, calls underlying layer after */
+					/*   possibly changing passed data */
+	SMB_VFS_LAYER_LOGGER,		/* - Logs data, calls underlying layer, logging does not */
+					/*   use Samba VFS */
+	SMB_VFS_LAYER_SPLITTER,		/* - Splits operation, calls underlying layer _and_ own facility, */
+					/*   then combines result */
+	SMB_VFS_LAYER_SCANNER		/* - Checks data and possibly initiates additional */
+					/*   file activity like logging to files _inside_ samba VFS */
+} vfs_op_layer;
+
+/*
+    VFS operation description. Each VFS module initialization function returns to VFS subsystem 
+    an array of vfs_op_tuple which describes all operations this module is willing to intercept. 
+    VFS subsystem initializes then vfs_ops using this information and passes it 
+    to next VFS module as underlying vfs_ops and to connection after all VFS modules are initialized.
+*/
+
+typedef struct _vfs_op_tuple {
+	void* op;
+	vfs_op_type type;
+	vfs_op_layer layer;
+} vfs_op_tuple;
+
+/*
+    Return vfs_ops filled with current opaque VFS operations. This function is designed to
+    be called from VFS module initialization function for those modules which needs 'direct' VFS
+    access (loggers or initiators of file operations other than connection asks for).
+    
+    Returned vfs_ops must be cleaned up in VFS module's finalizer function (vfs_done_<module_name>)
+    using safe_free().
+    
+    Prototype:
+    struct vfs_ops *smb_vfs_get_opaque_ops();
+    
+    This prototype will be available via include/proto.h
+*/
+
 #endif /* _VFS_H */