xref: /titanic_52/usr/src/uts/common/sys/ptms.h (revision 5c5f137104b2d56181283389fa902220f2023809)
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
39  * drivers. This structure is private and should not be used by any
40  * applications.
41  */
42 struct pt_ttys {
43 	queue_t *ptm_rdq; 	/* master's read queue pointer */
44 	queue_t *pts_rdq; 	/* slave's read queue pointer */
45 	mblk_t	*pt_nullmsg;	/* 0-bytes message block for pts close */
46 	pid_t	 pt_pid;	/* process id (for debugging) */
47 	minor_t	 pt_minor;	/* Minor number of this pty */
48 	int	 pt_refcnt;	/* reference count for ptm_rdq/pts_rdq uses */
49 	ushort_t pt_state;	/* state of master/slave pair */
50 	kcondvar_t pt_cv;	/* condition variable for exclusive access */
51 	kmutex_t pt_lock;	/* Per-element lock */
52 	zoneid_t pt_zoneid;	/* Zone membership for this pty */
53 	uid_t	 pt_ruid;	/* Real owner of pty */
54 	gid_t	 pt_rgid;	/* Real group owner of pty */
55 };
56 
57 /*
58  * pt_state values
59  */
60 #define	PTLOCK		0x01	/* master/slave pair is locked */
61 #define	PTMOPEN 	0x02  	/* master side is open */
62 #define	PTSOPEN 	0x04	/* slave side is open */
63 #define	PTSTTY		0x08	/* slave side is tty */
64 
65 /*
66  * Multi-threading primitives.
67  * Values of pt_refcnt: -1 if a writer is accessing the struct
68  *			0  if no one is reading or writing
69  *			> 0 equals to the number of readers accessing the struct
70  */
71 #define	PT_ENTER_READ(p) {			\
72 	mutex_enter(&(p)->pt_lock);		\
73 	while ((p)->pt_refcnt < 0)		\
74 		cv_wait(&((p)->pt_cv), &(p)->pt_lock);	\
75 	(p)->pt_refcnt++;			\
76 	mutex_exit(&(p)->pt_lock);		\
77 }
78 
79 #define	PT_ENTER_WRITE(p) {			\
80 	mutex_enter(&(p)->pt_lock);		\
81 	while ((p)->pt_refcnt != 0)		\
82 		cv_wait(&((p)->pt_cv), &(p)->pt_lock);	\
83 	(p)->pt_refcnt = -1;			\
84 	mutex_exit(&(p)->pt_lock);		\
85 }
86 
87 #define	PT_EXIT_READ(p) {			\
88 	mutex_enter(&(p)->pt_lock);		\
89 	ASSERT((p)->pt_refcnt > 0);		\
90 	if ((--((p)->pt_refcnt)) == 0)		\
91 		cv_broadcast(&(p)->pt_cv);	\
92 	mutex_exit(&(p)->pt_lock);		\
93 }
94 
95 #define	PT_EXIT_WRITE(p) {			\
96 	mutex_enter(&(p)->pt_lock);		\
97 	ASSERT((p)->pt_refcnt == -1);		\
98 	(p)->pt_refcnt = 0;			\
99 	cv_broadcast(&(p)->pt_cv);		\
100 	mutex_exit(&(p)->pt_lock);		\
101 }
102 
103 /*
104  * ptms_lock and pt_cnt are defined in ptms_conf.c
105  */
106 extern kmutex_t		ptms_lock;
107 extern dev_info_t 	*pts_dip;	/* private copy of devinfo ptr */
108 
109 extern void ptms_init(void);
110 extern struct pt_ttys *pt_ttys_alloc(void);
111 extern void ptms_close(struct pt_ttys *, uint_t);
112 extern struct pt_ttys *ptms_minor2ptty(minor_t);
113 extern int ptms_attach_slave(void);
114 extern int ptms_minor_valid(minor_t ptmin, uid_t *uid, gid_t *gid);
115 extern int ptms_minor_exists(minor_t ptmin);
116 extern void ptms_set_owner(minor_t ptmin, uid_t uid, gid_t gid);
117 extern major_t ptms_slave_attached(void);
118 
119 #ifdef DEBUG
120 extern void ptms_log(char *, uint_t);
121 extern void ptms_logp(char *, uintptr_t);
122 #define	DDBG(a, b) ptms_log(a, b)
123 #define	DDBGP(a, b) ptms_logp(a, b)
124 #else
125 #define	DDBG(a, b)
126 #define	DDBGP(a, b)
127 #endif
128 
129 #endif /* _KERNEL */
130 
131 typedef struct pt_own {
132 	uid_t	pto_ruid;
133 	gid_t	pto_rgid;
134 } pt_own_t;
135 
136 /*
137  * ioctl commands
138  *
139  *  ISPTM: Determines whether the file descriptor is that of an open master
140  *	   device. Return code of zero indicates that the file descriptor
141  *	   represents master device.
142  *
143  * UNLKPT: Unlocks the master and slave devices.  It returns 0 on success. On
144  *	   failure, the errno is set to EINVAL indicating that the master
145  *	   device is not open.
146  *
147  *  ZONEPT: Sets the zoneid of the pair of master and slave devices.  It
148  *	    returns 0 upon success.  Used to force a pty 'into' a zone upon
149  *	    zone entry.
150  *
151  * PT_OWNER: Sets uid and gid for slave device.  It returns 0 on success.
152  *
153  */
154 #define	ISPTM		(('P'<<8)|1)	/* query for master */
155 #define	UNLKPT		(('P'<<8)|2)	/* unlock master/slave pair */
156 #define	PTSSTTY		(('P'<<8)|3)	/* set tty flag */
157 #define	ZONEPT		(('P'<<8)|4)	/* set zone of master/slave pair */
158 #define	OWNERPT		(('P'<<8)|5)	/* set owner/group for slave device */
159 
160 #ifdef	__cplusplus
161 }
162 #endif
163 
164 #endif	/* _SYS_PTMS_H */
165