include/sys/logindmux_impl.h

   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 2003 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 #ifndef _SYS_LOGINDMUX_IMPL_H
  28 #define _SYS_LOGINDMUX_IMPL_H
  29
  30 #pragma ident   "%Z%%M% %I%     %E% SMI"
  31
  32 #include <sys/types.h>
  33 #include <sys/stream.h>
  34
  35 #ifdef  __cplusplus
  36 extern "C" {
  37 #endif
  38
  39
  40 /*
  41  * This structure is shared between two logindmux peer instances and
  42  * ensures that only one of the peers will be actively processing an
  43  * I_UNLINK ioctl at any one time.
  44  */
  45 typedef struct unlinkinfo {
  46         kmutex_t        state_lock;     /* serialize access to state */
  47         int             state;          /* state of I_UNLINK operation */
  48         mblk_t          *prot_mp;       /* carries protocol messages */
  49 } unlinkinfo_t;
  50
  51 /*
  52  * Logindmux state structure; one per open instance.
  53  */
  54 struct tmx {
  55         queue_t         *rdq;           /* our mux upper read queue */
  56         queue_t         *muxq;          /* our mux lower write queue */
  57         queue_t         *peerq;         /* peer mux lower write queue */
  58         minor_t         dev0;           /* our minor device number */
  59         boolean_t       isptm;          /* true if ptm is downstream */
  60         mblk_t          *unlink_mp;     /* mblk used in logdmux_unlink_timer */
  61         unlinkinfo_t    *unlinkinfop;   /* used during I_UNLINK processing */
  62         bufcall_id_t    wbufcid;        /* needed for recovery */
  63         bufcall_id_t    rbufcid;        /* needed for recovery */
  64         timeout_id_t    utimoutid;      /* unlink timer identifier */
  65         timeout_id_t    wtimoutid;      /* needed for recovery */
  66         timeout_id_t    rtimoutid;      /* needed for recovery */
  67 };
  68
  69 #define LOGDMX_ID               107     /* module id number */
  70
  71 /*
  72  * The arguments for calls to qtimeout, in microseconds.
  73  */
  74 #define SIMWAIT                 100000  /* logdmux_timer */
  75 #define LOGDMUX_POLL_WAIT       10      /* logdmux_unlink_timer */
  76
  77 /*
  78  * State of peer linkage.
  79  */
  80 enum {
  81         LOGDMUX_LINKED          = 1,    /* peer instances are in linked state */
  82         LOGDMUX_UNLINK_PENDING  = 2,    /* a peer is actively I_UNLINKing */
  83         LOGDMUX_UNLINKED        = 3     /* a peer has completed its I_UNLINK */
  84 };
  85
  86 /*
  87  * Protocol message magic cookie.
  88  */
  89 #define LOGDMUX_MCTL            (LOGDMX_ID << 16)
  90
  91 /*
  92  * peer to peer protocol messages.
  93  */
  94 #define LOGDMUX_UNLINK_REQ      (LOGDMUX_MCTL|1) /* peer wants to unlink */
  95 #define LOGDMUX_UNLINK_RESP     (LOGDMUX_MCTL|2) /* ok for peer to unlink */
  96
  97 /*
  98  * Macro to determine if an mblk is a logindmux protocol mblk.
  99  */
 100 #define LOGDMUX_PROTO_MBLK(mp)                                             \
 101         ((DB_TYPE(mp) == M_CTL)                                         && \
 102         ((mp)->b_cont != NULL)                                          && \
 103         (DB_TYPE((mp)->b_cont) == M_IOCTL)                              && \
 104         (((struct iocblk *)((mp)->b_cont->b_rptr))->ioc_cmd == I_UNLINK))
 105
 106
 107 #ifdef  __cplusplus
 108 }
 109 #endif
 110
 111 #endif  /* _SYS_LOGINDMUX_IMPL_H */