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 (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright (c) 1988, 2010, Oracle and/or its affiliates. All rights reserved.
  23  */
  24 /*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T     */
  25 /*        All Rights Reserved   */
  26 
  27 
  28 #ifndef _SYS_PTMS_H
  29 #define _SYS_PTMS_H
  30 
  31 #ifdef  __cplusplus
  32 extern "C" {
  33 #endif
  34 
  35 #ifdef _KERNEL
  36 
  37 /*
  38  * Structures and definitions supporting the pseudo-terminal drivers. This
  39  * structure is private and should not be used by any applications.
  40  */
  41 struct pt_ttys {
  42         queue_t *ptm_rdq;       /* manager's read queue pointer */
  43         queue_t *pts_rdq;       /* subsidiary's read queue pointer */
  44         mblk_t  *pt_nullmsg;    /* 0-bytes message block for pts close */
  45         pid_t    pt_pid;        /* process id (for debugging) */
  46         minor_t  pt_minor;      /* Minor number of this pty */
  47         int      pt_refcnt;     /* reference count for ptm_rdq/pts_rdq uses */
  48         ushort_t pt_state;      /* state of manager/subsidiary pair */
  49         kcondvar_t pt_cv;       /* condition variable for exclusive access */
  50         kmutex_t pt_lock;       /* Per-element lock */
  51         zoneid_t pt_zoneid;     /* Zone membership for this pty */
  52         uid_t    pt_ruid;       /* Real owner of pty */
  53         gid_t    pt_rgid;       /* Real group owner of pty */
  54 };
  55 
  56 /*
  57  * pt_state values
  58  */
  59 #define PTLOCK          0x01    /* manager/subsidiary pair is locked */
  60 #define PTMOPEN         0x02    /* manager side is open */
  61 #define PTSOPEN         0x04    /* subsidiary side is open */
  62 #define PTSTTY          0x08    /* subsidiary side is tty */
  63 
  64 /*
  65  * Multi-threading primitives.
  66  * Values of pt_refcnt: -1 if a writer is accessing the struct
  67  *                      0  if no one is reading or writing
  68  *                      > 0 equals to the number of readers accessing the struct
  69  */
  70 #define PT_ENTER_READ(p) {                      \
  71         mutex_enter(&(p)->pt_lock);              \
  72         while ((p)->pt_refcnt < 0)                \
  73                 cv_wait(&((p)->pt_cv), &(p)->pt_lock);    \
  74         (p)->pt_refcnt++;                    \
  75         mutex_exit(&(p)->pt_lock);               \
  76 }
  77 
  78 #define PT_ENTER_WRITE(p) {                     \
  79         mutex_enter(&(p)->pt_lock);              \
  80         while ((p)->pt_refcnt != 0)          \
  81                 cv_wait(&((p)->pt_cv), &(p)->pt_lock);    \
  82         (p)->pt_refcnt = -1;                 \
  83         mutex_exit(&(p)->pt_lock);               \
  84 }
  85 
  86 #define PT_EXIT_READ(p) {                       \
  87         mutex_enter(&(p)->pt_lock);              \
  88         ASSERT((p)->pt_refcnt > 0);               \
  89         if ((--((p)->pt_refcnt)) == 0)               \
  90                 cv_broadcast(&(p)->pt_cv);       \
  91         mutex_exit(&(p)->pt_lock);               \
  92 }
  93 
  94 #define PT_EXIT_WRITE(p) {                      \
  95         mutex_enter(&(p)->pt_lock);              \
  96         ASSERT((p)->pt_refcnt == -1);                \
  97         (p)->pt_refcnt = 0;                  \
  98         cv_broadcast(&(p)->pt_cv);               \
  99         mutex_exit(&(p)->pt_lock);               \
 100 }
 101 
 102 /*
 103  * ptms_lock and pt_cnt are defined in ptms_conf.c
 104  */
 105 extern kmutex_t         ptms_lock;
 106 extern dev_info_t       *pts_dip;       /* private copy of devinfo ptr */
 107 
 108 extern void ptms_init(void);
 109 extern struct pt_ttys *pt_ttys_alloc(void);
 110 extern void ptms_close(struct pt_ttys *, uint_t);
 111 extern struct pt_ttys *ptms_minor2ptty(minor_t);
 112 extern int ptms_attach_subsidiary(void);
 113 extern int ptms_minor_valid(minor_t ptmin, uid_t *uid, gid_t *gid);
 114 extern int ptms_minor_exists(minor_t ptmin);
 115 extern void ptms_set_owner(minor_t ptmin, uid_t uid, gid_t gid);
 116 extern major_t ptms_subsidiary_attached(void);
 117 
 118 #ifdef DEBUG
 119 extern void ptms_log(char *, uint_t);
 120 extern void ptms_logp(char *, uintptr_t);
 121 #define DDBG(a, b) ptms_log(a, b)
 122 #define DDBGP(a, b) ptms_logp(a, b)
 123 #else
 124 #define DDBG(a, b)
 125 #define DDBGP(a, b)
 126 #endif
 127 
 128 #endif /* _KERNEL */
 129 
 130 typedef struct pt_own {
 131         uid_t   pto_ruid;
 132         gid_t   pto_rgid;
 133 } pt_own_t;
 134 
 135 /*
 136  * IOCTL COMMANDS
 137  *
 138  *      ISPTM
 139  *              Determines whether the file descriptor is that of an open
 140  *              manager device.  Return code of zero indicates that the file
 141  *              descriptor represents a manager device.
 142  *
 143  *      UNLKPT
 144  *              Unlocks the manager and subsidiary devices.  It returns 0 on
 145  *              success.  On failure, the errno is set to EINVAL indicating
 146  *              that the manager device is not open.
 147  *
 148  *      ZONEPT
 149  *              Sets the zoneid of the pair of manager and subsidiary devices.
 150  *              It returns 0 upon success.  Used to force a pty 'into' a zone
 151  *              upon zone entry.
 152  *
 153  *      PT_OWNER
 154  *              Sets uid and gid for subsidiary device.  It returns 0 on
 155  *              success.
 156  */
 157 #define ISPTM           (('P'<<8)|1)  /* query for manager */
 158 #define UNLKPT          (('P'<<8)|2)  /* unlock manager/subsidiary pair */
 159 #define PTSSTTY         (('P'<<8)|3)  /* set tty flag */
 160 #define ZONEPT          (('P'<<8)|4)  /* set zone of manager/subsidiary pair */
 161 #define OWNERPT         (('P'<<8)|5)  /* set owner/group for subsidiary */
 162 
 163 #ifdef  __cplusplus
 164 }
 165 #endif
 166 
 167 #endif  /* _SYS_PTMS_H */