1/*
2 * Copyright (c) 2004-2020 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28/*
29 * Copyright (c) 1996 John S. Dyson
30 * All rights reserved.
31 *
32 * Redistribution and use in source and binary forms, with or without
33 * modification, are permitted provided that the following conditions
34 * are met:
35 * 1. Redistributions of source code must retain the above copyright
36 * notice immediately at the beginning of the file, without modification,
37 * this list of conditions, and the following disclaimer.
38 * 2. Redistributions in binary form must reproduce the above copyright
39 * notice, this list of conditions and the following disclaimer in the
40 * documentation and/or other materials provided with the distribution.
41 * 3. Absolutely no warranty of function or purpose is made by the author
42 * John S. Dyson.
43 * 4. This work was done expressly for inclusion into FreeBSD. Other use
44 * is allowed if this notation is included.
45 * 5. Modifications may be freely made to this file if the above conditions
46 * are met.
47 *
48 * $FreeBSD: src/sys/sys/pipe.h,v 1.24 2003/08/13 20:01:38 alc Exp $
49 */
50/*
51 * NOTICE: This file was modified by SPARTA, Inc. in 2006 to introduce
52 * support for mandatory and extensible security protections. This notice
53 * is included in support of clause 2.2 (b) of the Apple Public License,
54 * Version 2.0.
55 */
56
57#ifndef _SYS_PIPE_H_
58#define _SYS_PIPE_H_
59
60#ifdef KERNEL
61#include <libkern/locks.h>
62#include <os/base.h>
63#endif
64#include <sys/queue.h> /* for TAILQ macros */
65#include <sys/ev.h>
66#include <sys/cdefs.h>
67#include <sys/_types/_caddr_t.h>
68#include <sys/_types/_u_int.h>
69
70/*
71 * Pipe buffer size, keep moderate in value, pipes take kva space.
72 */
73#ifndef PIPE_SIZE
74#define PIPE_SIZE 16384
75#endif
76
77#define PIPE_KVAMAX (1024 * 1024 * 16)
78
79#ifndef BIG_PIPE_SIZE
80#define BIG_PIPE_SIZE (64*1024)
81#endif
82
83#ifndef SMALL_PIPE_SIZE
84#define SMALL_PIPE_SIZE PAGE_SIZE
85#endif
86
87/*
88 * PIPE_MINDIRECT MUST be smaller than PIPE_SIZE and MUST be bigger
89 * than PIPE_BUF.
90 */
91#ifndef PIPE_MINDIRECT
92#define PIPE_MINDIRECT 8192
93#endif
94
95#define PIPENPAGES (BIG_PIPE_SIZE / PAGE_SIZE + 1)
96
97/*
98 * Pipe buffer information.
99 * Separate in, out, cnt are used to simplify calculations.
100 * Buffered write is active when the buffer.cnt field is set.
101 */
102struct pipebuf {
103 u_int cnt; /* number of chars currently in buffer */
104 u_int in; /* in pointer */
105 u_int out; /* out pointer */
106 u_int size; /* size of buffer */
107#if KERNEL
108 caddr_t OS_PTRAUTH_SIGNED_PTR("pipe.buffer") buffer; /* kva of buffer */
109#else
110 caddr_t buffer; /* kva of buffer */
111#endif /* KERNEL */
112};
113
114
115#ifdef PIPE_DIRECT
116/*
117 * Information to support direct transfers between processes for pipes.
118 */
119struct pipemapping {
120 vm_offset_t kva; /* kernel virtual address */
121 vm_size_t cnt; /* number of chars in buffer */
122 vm_size_t pos; /* current position of transfer */
123 int npages; /* number of pages */
124 vm_page_t ms[PIPENPAGES]; /* pages in source process */
125};
126#endif
127
128/*
129 * Bits in pipe_state.
130 */
131#define PIPE_ASYNC 0x004 /* Async? I/O. */
132#define PIPE_WANTR 0x008 /* Reader wants some characters. */
133#define PIPE_WANTW 0x010 /* Writer wants space to put characters. */
134#define PIPE_WANT 0x020 /* Pipe is wanted to be run-down. */
135// was PIPE_SEL 0x040 /* Pipe has a select active. */
136#define PIPE_EOF 0x080 /* Pipe is in EOF condition. */
137#define PIPE_LOCKFL 0x100 /* Process has exclusive access to pointers/data. */
138#define PIPE_LWANT 0x200 /* Process wants exclusive access to pointers/data. */
139#define PIPE_DIRECTW 0x400 /* Pipe direct write active. */
140#define PIPE_DIRECTOK 0x800 /* Direct mode ok. */
141// was PIPE_KNOTE 0x1000
142#define PIPE_DRAIN 0x2000 /* Waiting for I/O to drop for a close. Treated like EOF;
143 * only separate for easier debugging. */
144#define PIPE_WSELECT 0x4000 /* Some thread has done an FWRITE select on the pipe */
145#define PIPE_DEAD 0x8000 /* Pipe is dead and needs garbage collection */
146
147#ifdef KERNEL
148
149struct label;
150
151/*
152 * Per-pipe data structure.
153 * Two of these are linked together to produce bi-directional pipes.
154 */
155struct pipe {
156 struct pipebuf pipe_buffer; /* data storage */
157#ifdef PIPE_DIRECT
158 struct pipemapping pipe_map; /* pipe mapping for direct I/O */
159#endif
160 struct selinfo pipe_sel; /* for compat with select */
161 pid_t pipe_pgid; /* information for async I/O */
162 struct pipe *pipe_peer; /* link with other direction */
163 u_int pipe_state; /* pipe status info */
164 int pipe_busy; /* busy flag, mostly to handle rundown sanely */
165 lck_mtx_t *pipe_mtxp; /* shared mutex between both pipes */
166 struct timespec st_atimespec; /* time of last access */
167 struct timespec st_mtimespec; /* time of last data modification */
168 struct timespec st_ctimespec; /* time of last status change */
169 struct label *pipe_label; /* pipe MAC label - shared */
170};
171
172#define PIPE_MTX(pipe) ((pipe)->pipe_mtxp)
173
174#define PIPE_LOCK(pipe) lck_mtx_lock(PIPE_MTX(pipe))
175#define PIPE_UNLOCK(pipe) lck_mtx_unlock(PIPE_MTX(pipe))
176#define PIPE_LOCK_ASSERT(pipe, type) LCK_MTX_ASSERT(PIPE_MTX(pipe), (type))
177
178__BEGIN_DECLS
179extern int pipe_stat(struct pipe *, void *, int);
180#ifdef BSD_KERNEL_PRIVATE
181extern uint64_t pipe_id(struct pipe *);
182#endif
183__END_DECLS
184
185#endif /* KERNEL */
186
187#endif /* !_SYS_PIPE_H_ */
188