xref: /illumos-gate/usr/src/uts/common/sys/ptms.h (revision 1fa2a664)
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 */
168