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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 1990-1998 by Sun Microsystems, Inc.
* All rights reserved.
*/
#ifndef _SYS_STRREDIR_H
#define _SYS_STRREDIR_H
#pragma ident "%Z%%M% %I% %E% SMI"
#ifdef __cplusplus
extern "C" {
#endif
/*
* strredir.h: Declarations for the redirection driver and its matching
* STREAMS module.
*/
/*
* The module's module id.
*
* XXX: Since there's no authority responsible for administering this name
* space, there's no guarantee that this value is unique. That wouldn't
* be so bad except that the DKI now suggests that ioctl cookie values
* should be based on module id to make them unique...
*/
#define _STRREDIR_MODID 7326
/*
* Redirection ioctls:
*/
#define SRIOCSREDIR ((_STRREDIR_MODID<<16) | 1) /* set redir target */
#define SRIOCISREDIR ((_STRREDIR_MODID<<16) | 2) /* is redir target? */
/*
* Everything from here on is of interest only to the kernel.
*/
#ifdef _KERNEL
#include <sys/types.h>
#include <sys/cred.h>
#include <sys/vnode.h>
/*
* Per-open instance driver state information.
*
* The underlying device potentially can be opened through (at least) two
* paths: through this driver and through the underlying device's driver. To
* ensure that reference counts are meaningful and therefore that close
* routines are called at the right time, it's important to make sure that the
* snode for the underlying device instance never has a contribution of more
* than one through this driver, regardless of how many times this driver's
* been opened. The wd_wsconsopen field keeps track of the necessary
* information to ensure this property.
*
* The structure also contains copies of the flag and cred values supplied
* when the device instance was first opened, so that it's possible to reopen
* the underlying device in srreset.
*/
typedef struct wcd_data {
struct wcd_data *wd_next; /* link to next open instance */
minor_t wd_unit; /* minor device # for this instance */
struct wcrlist *wd_list; /* the head of the redirection list */
vnode_t *wd_vp; /* underlying device instance vnode */
int wd_wsconsopen; /* see above */
int wd_flag; /* see above */
cred_t *wd_cred; /* see above */
} wcd_data_t;
/*
* Per-open instance module state information.
*
* An invariant: when wm_wd is non-NULL, wm_entry is also non-NULL and is on
* the list rooted at wm_wd->wd_list.
*/
typedef struct wcm_data {
struct wcd_data *wm_wd; /* Xref to redir driver data */
struct wcrlist *wm_entry; /* Redir entry that refers to us */
} wcm_data_t;
/*
* We record the list of redirections as a linked list of wcrlist
* structures.
*
* We need to keep track of:
* 1) The target's vp, so that we can vector reads, writes, etc. off to the
* current designee.
* 2) The per-open instance private data structure of the redirmod module
* instance we push onto the target stream, so that we can clean up there
* when we go away. (I'm not sure that this is actually necessary.)
*/
typedef struct wcrlist {
struct wcrlist *wl_next; /* next entry */
vnode_t *wl_vp; /* target's vnode */
struct wcm_data *wl_data; /* target's redirmod private data */
} wcrlist_t;
/*
* A given instance of the redirection driver must be able to open the
* corresponding instance of the underlying device when the redirection list
* empties. To do so it needs a vnode for the underlying instance. The
* underlying driver is responsible for supplying routines for producing and
* disposing of this vnode. The get routine must return a held vnode, so that
* it can't vanish while the redirecting driver is using it.
*/
typedef struct srvnops {
int (*svn_get)(); /* (minor #, vpp) --> errno value */
void (*svn_rele)(); /* (minor #, vp) */
} srvnops_t;
extern void srpop(wcm_data_t *, int, cred_t *);
#endif /* _KERNEL */
#ifdef __cplusplus
}
#endif
#endif /* _SYS_STRREDIR_H */
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