xref: /titanic_52/usr/src/uts/common/sys/ptms.h (revision 9512fe850e98fdd448c638ca63fdd92a8a510255)
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 2006 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
26 /*	  All Rights Reserved  	*/
27 
28 
29 #ifndef _SYS_PTMS_H
30 #define	_SYS_PTMS_H
31 
32 #pragma ident	"%Z%%M%	%I%	%E% SMI"
33 
34 #ifdef	__cplusplus
35 extern "C" {
36 #endif
37 
38 /*
39  * Structures and definitions supporting the pseudo terminal
40  * drivers. This structure is private and should not be used by any
41  * applications.
42  */
43 struct pt_ttys {
44 	queue_t *ptm_rdq; 	/* master's read queue pointer */
45 	queue_t *pts_rdq; 	/* slave's read queue pointer */
46 	mblk_t	*pt_nullmsg;	/* 0-bytes message block for pts close */
47 	pid_t	 pt_pid;	/* process id (for debugging) */
48 	minor_t	 pt_minor;	/* Minor number of this pty */
49 	int	 pt_refcnt;	/* reference count for ptm_rdq/pts_rdq uses */
50 	ushort_t pt_state;	/* state of master/slave pair */
51 	kcondvar_t pt_cv;	/* condition variable for exclusive access */
52 	kmutex_t pt_lock;	/* Per-element lock */
53 	zoneid_t pt_zoneid;	/* Zone membership for this pty */
54 	uid_t	 pt_ruid;	/* Real owner of pty */
55 	gid_t	 pt_rgid;	/* Real group owner of pty */
56 };
57 
58 /*
59  * pt_state values
60  */
61 #define	PTLOCK		0x01	/* master/slave pair is locked */
62 #define	PTMOPEN 	0x02  	/* master side is open */
63 #define	PTSOPEN 	0x04	/* slave side is open */
64 #define	PTSTTY		0x08	/* slave side is tty */
65 
66 #ifdef _KERNEL
67 
68 /*
69  * Multi-threading primitives.
70  * Values of pt_refcnt: -1 if a writer is accessing the struct
71  *			0  if no one is reading or writing
72  *			> 0 equals to the number of readers accessing the struct
73  */
74 #define	PT_ENTER_READ(p) {			\
75 	mutex_enter(&(p)->pt_lock);		\
76 	while ((p)->pt_refcnt < 0)		\
77 		cv_wait(&((p)->pt_cv), &(p)->pt_lock);	\
78 	(p)->pt_refcnt++;			\
79 	mutex_exit(&(p)->pt_lock);		\
80 }
81 
82 #define	PT_ENTER_WRITE(p) {			\
83 	mutex_enter(&(p)->pt_lock);		\
84 	while ((p)->pt_refcnt != 0)		\
85 		cv_wait(&((p)->pt_cv), &(p)->pt_lock);	\
86 	(p)->pt_refcnt = -1;			\
87 	mutex_exit(&(p)->pt_lock);		\
88 }
89 
90 #define	PT_EXIT_READ(p) {			\
91 	mutex_enter(&(p)->pt_lock);		\
92 	ASSERT((p)->pt_refcnt > 0);		\
93 	if ((--((p)->pt_refcnt)) == 0)		\
94 		cv_broadcast(&(p)->pt_cv);	\
95 	mutex_exit(&(p)->pt_lock);		\
96 }
97 
98 #define	PT_EXIT_WRITE(p) {			\
99 	mutex_enter(&(p)->pt_lock);		\
100 	ASSERT((p)->pt_refcnt == -1);		\
101 	(p)->pt_refcnt = 0;			\
102 	cv_broadcast(&(p)->pt_cv);		\
103 	mutex_exit(&(p)->pt_lock);		\
104 }
105 
106 /*
107  * ptms_lock and pt_cnt are defined in ptms_conf.c
108  */
109 extern kmutex_t		ptms_lock;
110 extern dev_info_t 	*pts_dip;	/* private copy of devinfo ptr */
111 
112 extern void ptms_init(void);
113 extern struct pt_ttys *pt_ttys_alloc(void);
114 extern void ptms_close(struct pt_ttys *, uint_t);
115 extern struct pt_ttys *ptms_minor2ptty(minor_t);
116 extern int ptms_attach_slave(void);
117 extern int ptms_minor_valid(minor_t ptmin, uid_t *uid, gid_t *gid);
118 extern int ptms_minor_exists(minor_t ptmin);
119 extern void ptms_set_owner(minor_t ptmin, uid_t uid, gid_t gid);
120 extern major_t ptms_slave_attached(void);
121 
122 #ifdef DEBUG
123 extern void ptms_log(char *, uint_t);
124 extern void ptms_logp(char *, uintptr_t);
125 #define	DDBG(a, b) ptms_log(a, b)
126 #define	DDBGP(a, b) ptms_logp(a, b)
127 #else
128 #define	DDBG(a, b)
129 #define	DDBGP(a, b)
130 #endif
131 
132 #endif /* _KERNEL */
133 
134 /*
135  * ioctl commands
136  *
137  *   ISPTM: Determines whether the file descriptor is that of an open master
138  *	    device. Return code of zero indicates that the file descriptor
139  *	    represents master device.
140  *
141  *  UNLKPT: Unlocks the master and slave devices.  It returns 0 on success. On
142  *	    failure, the errno is set to EINVAL indicating that the master
143  *	    device is not open.
144  *
145  *  ZONEPT: Sets the zoneid of the pair of master and slave devices.  It
146  *	    returns 0 upon success.  Used to force a pty 'into' a zone upon
147  *	    zone entry.
148  *
149  * PT_OWNER: Sets uid and gid for slave device.  It returns 0 on success.
150  *
151  */
152 #define	ISPTM	(('P'<<8)|1)	/* query for master */
153 #define	UNLKPT	(('P'<<8)|2)	/* unlock master/slave pair */
154 #define	PTSSTTY	(('P'<<8)|3)	/* set tty flag */
155 #define	ZONEPT	(('P'<<8)|4)	/* set zone of master/slave pair */
156 #define	PT_OWNER (('P'<<8)|5)	/* set owner and group for slave device */
157 
158 typedef struct pt_own {
159 	uid_t	pto_ruid;
160 	gid_t	pto_rgid;
161 } pt_own_t;
162 
163 #ifdef	__cplusplus
164 }
165 #endif
166 
167 #endif	/* _SYS_PTMS_H */
168