1/*- 2 * Copyright (c) 1996 John S. Dyson 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice immediately at the beginning of the file, without modification, 10 * this list of conditions, and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Absolutely no warranty of function or purpose is made by the author 15 * John S. Dyson. 16 * 4. This work was done expressly for inclusion into FreeBSD. Other use 17 * is allowed if this notation is included. 18 * 5. Modifications may be freely made to this file if the above conditions 19 * are met. 20 */ 21 22#ifndef _SYS_PIPE_H_ 23#define _SYS_PIPE_H_ 24 25/* 26 * Pipe buffer size, keep moderate in value, pipes take kva space. 27 */ 28#ifndef PIPE_SIZE 29#define PIPE_SIZE 16384 30#endif 31 32#ifndef BIG_PIPE_SIZE 33#define BIG_PIPE_SIZE (64*1024) 34#endif 35 36#ifndef SMALL_PIPE_SIZE 37#define SMALL_PIPE_SIZE PAGE_SIZE 38#endif 39 40/* 41 * PIPE_MINDIRECT MUST be smaller than PIPE_SIZE and MUST be bigger 42 * than PIPE_BUF. 43 */ 44#ifndef PIPE_MINDIRECT 45#define PIPE_MINDIRECT 8192 46#endif 47 48#define PIPENPAGES (BIG_PIPE_SIZE / PAGE_SIZE + 1) 49 50#ifdef _KERNEL 51/* 52 * See sys_pipe.c for info on what these limits mean. 53 */ 54extern long maxpipekva; 55extern struct fileops pipeops; 56#endif 57 58/* 59 * Pipe buffer information. 60 * Separate in, out, cnt are used to simplify calculations. 61 * Buffered write is active when the buffer.cnt field is set. 62 */ 63struct pipebuf { 64 u_int cnt; /* number of chars currently in buffer */ 65 u_int in; /* in pointer */ 66 u_int out; /* out pointer */ 67 u_int size; /* size of buffer */ 68 caddr_t buffer; /* kva of buffer */ 69}; 70 71/* 72 * Information to support direct transfers between processes for pipes. 73 */ 74struct pipemapping { 75 u_int cnt; /* number of chars in buffer */ 76 u_int pos; /* current position of transfer */ 77 int npages; /* number of pages */ 78 vm_page_t ms[PIPENPAGES]; /* pages in source process */ 79}; 80 81/* 82 * Bits in pipe_state. 83 */ 84#define PIPE_ASYNC 0x004 /* Async? I/O. */ 85#define PIPE_WANTR 0x008 /* Reader wants some characters. */ 86#define PIPE_WANTW 0x010 /* Writer wants space to put characters. */ 87#define PIPE_WANT 0x020 /* Pipe is wanted to be run-down. */ 88#define PIPE_SEL 0x040 /* Pipe has a select active. */ 89#define PIPE_EOF 0x080 /* Pipe is in EOF condition. */ 90#define PIPE_LOCKFL 0x100 /* Process has exclusive access to pointers/data. */ 91#define PIPE_LWANT 0x200 /* Process wants exclusive access to pointers/data. */ 92#define PIPE_DIRECTW 0x400 /* Pipe direct write active. */ 93#define PIPE_DIRECTOK 0x800 /* Direct mode ok. */ 94 95/* 96 * Bits in pipe_type. 97 */ 98#define PIPE_TYPE_NAMED 0x001 /* Is a named pipe. */ 99 100/* 101 * Per-pipe data structure. 102 * Two of these are linked together to produce bi-directional pipes. 103 */ 104struct pipe { 105 struct pipebuf pipe_buffer; /* data storage */ 106 struct pipemapping pipe_pages; /* wired pages for direct I/O */ 107 struct selinfo pipe_sel; /* for compat with select */ 108 struct timespec pipe_atime; /* time of last access */ 109 struct timespec pipe_mtime; /* time of last modify */ 110 struct timespec pipe_ctime; /* time of status change */ 111 struct sigio *pipe_sigio; /* information for async I/O */ 112 struct pipe *pipe_peer; /* link with other direction */ 113 struct pipepair *pipe_pair; /* container structure pointer */ 114 u_short pipe_state; /* pipe status info */ 115 u_char pipe_type; /* pipe type info */ 116 u_char pipe_present; /* still present? */ 117 int pipe_waiters; /* pipelock waiters */ 118 int pipe_busy; /* busy flag, mostly to handle rundown sanely */ 119 int pipe_wgen; /* writer generation for named pipe */ 120 ino_t pipe_ino; /* fake inode for stat(2) */ 121}; 122 123/* 124 * Values for the pipe_present. 125 */ 126#define PIPE_ACTIVE 1 127#define PIPE_CLOSING 2 128#define PIPE_FINALIZED 3 129 130/* 131 * Container structure to hold the two pipe endpoints, mutex, and label 132 * pointer. 133 */ 134struct pipepair { 135 struct pipe pp_rpipe; 136 struct pipe pp_wpipe; 137 struct mtx pp_mtx; 138 struct label *pp_label; 139}; 140 141#define PIPE_MTX(pipe) (&(pipe)->pipe_pair->pp_mtx) 142#define PIPE_LOCK(pipe) mtx_lock(PIPE_MTX(pipe)) 143#define PIPE_UNLOCK(pipe) mtx_unlock(PIPE_MTX(pipe)) 144#define PIPE_LOCK_ASSERT(pipe, type) mtx_assert(PIPE_MTX(pipe), (type)) 145 146#ifdef _KERNEL 147void pipe_dtor(struct pipe *dpipe); 148int pipe_named_ctor(struct pipe **ppipe, struct thread *td); 149void pipeselwakeup(struct pipe *cpipe); 150#endif 151#endif /* !_SYS_PIPE_H_ */ 152