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, Version 1.0 only
6 * (the "License").  You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22/*
23 * Copyright (c) 1991, 1997-1998 by Sun Microsystems, Inc.
24 * All rights reserved.
25 */
26
27#ifndef	_SYS_BUFMOD_H
28#define	_SYS_BUFMOD_H
29
30#pragma ident	"%Z%%M%	%I%	%E% SMI"
31
32#include <sys/types.h>
33#include <sys/types32.h>
34
35#ifdef	__cplusplus
36extern "C" {
37#endif
38
39/*
40 * Definitions for the STREAMS Buffering module.
41 *
42 * The module gathers incoming (read-side) messages together into
43 * "chunks" and passes completed chunks up to the next module in
44 * line.  The gathering process is controlled by two ioctl-settable
45 * parameters:
46 *
47 * timeout	The maximum delay after passing the previous chunk
48 *		upward before passing the current one up, even if the
49 *		chunk isn't full.  If the timeout value passed in is
50 *		a null pointer, the timeout is infinite (as in the
51 *		select system call); this is the default.
52 * chunksize	The maximum size of a chunk of accumulated messages,
53 *		unless a single message exceeds the chunksize, in
54 *		which case it's passed up in a chunk containing only
55 *		that message.  Note that a given message's size includes
56 *		the length of any leading M_PROTO blocks it may have.
57 *
58 * There is one important side-effect: setting the timeout to zero
59 * (polling) will force the chunksize to zero, regardless of its
60 * previous setting.
61 */
62
63/*
64 * Ioctls.
65 */
66#define	SBIOC	('B' << 8)
67#define	SBIOCSTIME	(SBIOC|1)	/* set timeout info */
68#define	SBIOCGTIME	(SBIOC|2)	/* get timeout info */
69#define	SBIOCCTIME	(SBIOC|3)	/* clear timeout */
70#define	SBIOCSCHUNK	(SBIOC|4)	/* set chunksize */
71#define	SBIOCGCHUNK	(SBIOC|5)	/* get chunksize */
72#define	SBIOCSSNAP	(SBIOC|6)	/* set snapshot length */
73#define	SBIOCGSNAP	(SBIOC|7)	/* get snapshot length */
74#define	SBIOCSFLAGS	(SBIOC|8)	/* set buffering modes */
75#define	SBIOCGFLAGS	(SBIOC|9)	/* get buffering modes */
76
77/*
78 * Default chunk size.
79 */
80#define	SB_DFLT_CHUNK	8192	/* arbitrary */
81
82/*
83 * buffering flags
84 */
85
86#define	SB_SEND_ON_WRITE	1	/* return buffered read data on write */
87#define	SB_NO_HEADER		2	/* don't add header structure to data */
88#define	SB_NO_PROTO_CVT		4	/* don't convert proto to data */
89#define	SB_DEFER_CHUNK		8	/* fast response time buffering */
90#define	SB_NO_DROPS		16	/* Don't drop messages */
91
92/*
93 * buffering state
94 */
95#define	SB_FRCVD	1	/* first message in time window received */
96
97/*
98 * When adding a given message to an accumulating chunk, the module
99 * first converts any leading M_PROTO data block to M_DATA.
100 * It then constructs an sb_hdr (defined below), prepends it to
101 * the message, and pads the result out to force its length to a
102 * multiple of a machine-dependent alignment size guaranteed to be
103 * at least sizeof (ulong_t).  It then adds the padded message to the
104 * chunk.
105 *
106 * sb_origlen is the original length of the message after the M_PROTO => M_DATA
107 * conversion, but before truncating or adding the header.
108 *
109 * sb_msglen is the length of the message after truncation, but before
110 * adding the header.
111 *
112 * sb_totlen is the length of the message after truncation, and including
113 * both the header itself and the trailing padding bytes.
114 *
115 * sb_drops is the cumulative number of messages dropped by the module
116 * due to stream read-side flow control or resource exhaustion.
117 *
118 * sb_timestamp is the packet arrival time expressed as a 'struct timeval'.
119 */
120
121struct sb_hdr {
122	uint_t	sbh_origlen;
123	uint_t	sbh_msglen;
124	uint_t	sbh_totlen;
125	uint_t	sbh_drops;
126#if defined(_LP64) || defined(_I32LPx)
127	struct	timeval32 sbh_timestamp;
128#else
129	struct	timeval sbh_timestamp;
130#endif /* !_LP64 */
131};
132
133#ifdef	__cplusplus
134}
135#endif
136
137#endif	/* _SYS_BUFMOD_H */
138