1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright (c) 1990-1998 by Sun Microsystems, Inc. 24 * All rights reserved. 25 */ 26 27 #ifndef _SYS_STRREDIR_H 28 #define _SYS_STRREDIR_H 29 30 #pragma ident "%Z%%M% %I% %E% SMI" 31 32 #ifdef __cplusplus 33 extern "C" { 34 #endif 35 36 /* 37 * strredir.h: Declarations for the redirection driver and its matching 38 * STREAMS module. 39 */ 40 41 /* 42 * The module's module id. 43 * 44 * XXX: Since there's no authority responsible for administering this name 45 * space, there's no guarantee that this value is unique. That wouldn't 46 * be so bad except that the DKI now suggests that ioctl cookie values 47 * should be based on module id to make them unique... 48 */ 49 #define _STRREDIR_MODID 7326 50 51 /* 52 * Redirection ioctls: 53 */ 54 #define SRIOCSREDIR ((_STRREDIR_MODID<<16) | 1) /* set redir target */ 55 #define SRIOCISREDIR ((_STRREDIR_MODID<<16) | 2) /* is redir target? */ 56 57 58 /* 59 * Everything from here on is of interest only to the kernel. 60 */ 61 #ifdef _KERNEL 62 63 #include <sys/types.h> 64 #include <sys/cred.h> 65 #include <sys/vnode.h> 66 67 /* 68 * Per-open instance driver state information. 69 * 70 * The underlying device potentially can be opened through (at least) two 71 * paths: through this driver and through the underlying device's driver. To 72 * ensure that reference counts are meaningful and therefore that close 73 * routines are called at the right time, it's important to make sure that the 74 * snode for the underlying device instance never has a contribution of more 75 * than one through this driver, regardless of how many times this driver's 76 * been opened. The wd_wsconsopen field keeps track of the necessary 77 * information to ensure this property. 78 * 79 * The structure also contains copies of the flag and cred values supplied 80 * when the device instance was first opened, so that it's possible to reopen 81 * the underlying device in srreset. 82 */ 83 typedef struct wcd_data { 84 struct wcd_data *wd_next; /* link to next open instance */ 85 minor_t wd_unit; /* minor device # for this instance */ 86 struct wcrlist *wd_list; /* the head of the redirection list */ 87 vnode_t *wd_vp; /* underlying device instance vnode */ 88 int wd_wsconsopen; /* see above */ 89 int wd_flag; /* see above */ 90 cred_t *wd_cred; /* see above */ 91 } wcd_data_t; 92 93 /* 94 * Per-open instance module state information. 95 * 96 * An invariant: when wm_wd is non-NULL, wm_entry is also non-NULL and is on 97 * the list rooted at wm_wd->wd_list. 98 */ 99 typedef struct wcm_data { 100 struct wcd_data *wm_wd; /* Xref to redir driver data */ 101 struct wcrlist *wm_entry; /* Redir entry that refers to us */ 102 } wcm_data_t; 103 104 /* 105 * We record the list of redirections as a linked list of wcrlist 106 * structures. 107 * 108 * We need to keep track of: 109 * 1) The target's vp, so that we can vector reads, writes, etc. off to the 110 * current designee. 111 * 2) The per-open instance private data structure of the redirmod module 112 * instance we push onto the target stream, so that we can clean up there 113 * when we go away. (I'm not sure that this is actually necessary.) 114 */ 115 typedef struct wcrlist { 116 struct wcrlist *wl_next; /* next entry */ 117 vnode_t *wl_vp; /* target's vnode */ 118 struct wcm_data *wl_data; /* target's redirmod private data */ 119 } wcrlist_t; 120 121 /* 122 * A given instance of the redirection driver must be able to open the 123 * corresponding instance of the underlying device when the redirection list 124 * empties. To do so it needs a vnode for the underlying instance. The 125 * underlying driver is responsible for supplying routines for producing and 126 * disposing of this vnode. The get routine must return a held vnode, so that 127 * it can't vanish while the redirecting driver is using it. 128 */ 129 typedef struct srvnops { 130 int (*svn_get)(); /* (minor #, vpp) --> errno value */ 131 void (*svn_rele)(); /* (minor #, vp) */ 132 } srvnops_t; 133 134 extern void srpop(wcm_data_t *, int, cred_t *); 135 136 #endif /* _KERNEL */ 137 138 #ifdef __cplusplus 139 } 140 #endif 141 142 #endif /* _SYS_STRREDIR_H */ 143