1/* $OpenBSD: shm.h,v 1.31 2024/10/26 05:39:03 jsg Exp $ */
2/* $NetBSD: shm.h,v 1.20 1996/04/09 20:55:35 cgd Exp $ */
3
4/*
5 * Copyright (c) 1994 Adam Glass
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by Adam Glass.
19 * 4. The name of the author may not be used to endorse or promote products
20 * derived from this software without specific prior written permission
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34/*
35 * As defined+described in "X/Open System Interfaces and Headers"
36 * Issue 4, p. XXX
37 */
38
39#ifndef _SYS_SHM_H_
40#define _SYS_SHM_H_
41
42#ifndef _SYS_IPC_H_
43#include <sys/ipc.h>
44#endif
45
46#if __BSD_VISIBLE
47
48/* shm-specific sysctl variables corresponding to members of struct shminfo */
49#define KERN_SHMINFO_SHMMAX 1 /* int: max shm segment size (bytes) */
50#define KERN_SHMINFO_SHMMIN 2 /* int: min shm segment size (bytes) */
51#define KERN_SHMINFO_SHMMNI 3 /* int: max number of shm identifiers */
52#define KERN_SHMINFO_SHMSEG 4 /* int: max shm segments per process */
53#define KERN_SHMINFO_SHMALL 5 /* int: max amount of shm (pages) */
54#define KERN_SHMINFO_MAXID 6 /* number of valid shared memory ids */
55
56#define CTL_KERN_SHMINFO_NAMES { \
57 { 0, 0 }, \
58 { "shmmax", CTLTYPE_INT }, \
59 { "shmmin", CTLTYPE_INT }, \
60 { "shmmni", CTLTYPE_INT }, \
61 { "shmseg", CTLTYPE_INT }, \
62 { "shmall", CTLTYPE_INT }, \
63}
64
65/*
66 * Old (deprecated) access mode definitions--do not use.
67 * Provided for compatibility with old code only.
68 */
69#define SHM_R IPC_R
70#define SHM_W IPC_W
71
72#endif /* __BSD_VISIBLE */
73
74/*
75 * Shared memory operation flags for shmat(2).
76 */
77#define SHM_RDONLY 010000 /* Attach read-only (else read-write) */
78#define SHM_RND 020000 /* Round attach address to SHMLBA */
79
80/*
81 * Shared memory specific control commands for shmctl().
82 * We accept but ignore these (XXX).
83 */
84#define SHM_LOCK 3 /* Lock segment in memory. */
85#define SHM_UNLOCK 4 /* Unlock a segment locked by SHM_LOCK. */
86
87/*
88 * Segment low boundary address multiple
89 */
90#define SHMLBA (1U << _MAX_PAGE_SHIFT)
91
92typedef short shmatt_t;
93
94struct shmid_ds {
95 struct ipc_perm shm_perm; /* operation permission structure */
96 int shm_segsz; /* size of segment in bytes */
97 pid_t shm_lpid; /* process ID of last shm op */
98 pid_t shm_cpid; /* process ID of creator */
99 shmatt_t shm_nattch; /* number of current attaches */
100 time_t shm_atime; /* time of last shmat() */
101 long __shm_atimensec;
102 time_t shm_dtime; /* time of last shmdt() */
103 long __shm_dtimensec;
104 time_t shm_ctime; /* time of last change by shmctl() */
105 long __shm_ctimensec;
106 void *shm_internal; /* implementation specific data */
107};
108
109#if __BSD_VISIBLE
110/*
111 * System V style catch-all structure for shared memory constants that
112 * might be of interest to user programs. Do we really want/need this?
113 */
114struct shminfo {
115 int shmmax; /* max shared memory segment size (bytes) */
116 int shmmin; /* min shared memory segment size (bytes) */
117 int shmmni; /* max number of shared memory identifiers */
118 int shmseg; /* max shared memory segments per process */
119 int shmall; /* max amount of shared memory (pages) */
120};
121
122struct shm_sysctl_info {
123 struct shminfo shminfo;
124 struct shmid_ds shmids[1];
125};
126#endif /* __BSD_VISIBLE */
127
128#ifdef _KERNEL
129extern struct shminfo shminfo;
130extern struct shmid_ds **shmsegs;
131
132struct vmspace;
133
134void shminit(void);
135void shmfork(struct vmspace *, struct vmspace *);
136void shmexit(struct vmspace *);
137int sysctl_sysvshm(int *, u_int, void *, size_t *, void *, size_t);
138
139#else /* !_KERNEL */
140
141__BEGIN_DECLS
142void *shmat(int, const void *, int);
143int shmctl(int, int, struct shmid_ds *);
144int shmdt(const void *);
145int shmget(key_t, size_t, int);
146__END_DECLS
147
148#endif /* !_KERNEL */
149
150#endif /* !_SYS_SHM_H_ */