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Test universal hashing and fix bugs.
[mLib] / pkbuf.h
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436fddaa 1/* -*-c-*-
2 *
0daaeb18 3 * $Id: pkbuf.h,v 1.4 2002/01/13 13:33:51 mdw Exp $
436fddaa 4 *
5 * Simple packet buffering
6 *
7 * (c) 2000 Straylight/Edgeware
8 */
9
10/*----- Licensing notice --------------------------------------------------*
11 *
12 * This file is part of the mLib utilities library.
13 *
14 * mLib is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU Library General Public License as
16 * published by the Free Software Foundation; either version 2 of the
17 * License, or (at your option) any later version.
18 *
19 * mLib is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU Library General Public License for more details.
23 *
24 * You should have received a copy of the GNU Library General Public
25 * License along with mLib; if not, write to the Free
26 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
27 * MA 02111-1307, USA.
28 */
29
30/*----- Revision history --------------------------------------------------*
31 *
32 * $Log: pkbuf.h,v $
0daaeb18 33 * Revision 1.4 2002/01/13 13:33:51 mdw
34 * Packet handler functions now have a @typedef@ name.
35 *
3fd896a4 36 * Revision 1.3 2001/02/03 16:23:33 mdw
37 * Bug fix: handle a disable during a close-induced flush without dumping
38 * core.
39 *
393cf1d9 40 * Revision 1.2 2001/01/20 12:06:01 mdw
41 * Define flags with macros, to ensure unsignedness.
42 *
436fddaa 43 * Revision 1.1 2000/06/17 10:39:19 mdw
44 * Experimental new support for packet buffering.
45 *
46 */
47
48#ifndef MLIB_PKBUF_H
49#define MLIB_PKBUF_H
50
51#ifdef __cplusplus
52 extern "C" {
53#endif
54
55/*----- Header files ------------------------------------------------------*/
56
57#include <stddef.h>
58
59#ifndef MLIB_ARENA_H
60# include "arena.h"
61#endif
62
63#ifndef MLIB_BITS_H
64# include "bits.h"
65#endif
66
67/*----- Data structures ---------------------------------------------------*/
68
0daaeb18 69struct pkbuf;
70
71typedef void pkbuf_func(octet */*b*/, size_t /*sz*/,
72 struct pkbuf */*pk*/, size_t */*keep*/,
73 void */*p*/);
74
436fddaa 75typedef struct pkbuf {
76 size_t sz; /* Size of current buffer */
77 size_t len; /* Length of data in the buffer */
78 size_t want; /* Want this many bytes for packet */
79 unsigned f; /* Various state flags */
0daaeb18 80 pkbuf_func *func; /* Handler function */
436fddaa 81 void *p; /* Argument for handler */
82 arena *a; /* Memory allocation arena */
83 octet *buf; /* Actual buffer space */
84} pkbuf;
85
393cf1d9 86#define PKBUF_ENABLE 1u /* Buffer is currently enabled */
3fd896a4 87#define PKBUF_CLOSE 2u /* Buffer is now closed */
436fddaa 88
89/*----- Functions provided ------------------------------------------------*/
90
91/* --- @pkbuf_flush@ --- *
92 *
93 * Arguments: @pkbuf *pk@ = pointer to buffer block
94 * @octet *p@ = pointer to where to start searching
95 * @size_t len@ = length of new material added
96 *
97 * Returns: ---
98 *
99 * Use: Flushes any complete packets in a packet buffer. New
100 * material is assumed to have been added starting at @p@. If
101 * @p@ is null, then the scan starts at the beginning of the
102 * buffer, and the size of data already in the buffer is used in
103 * place of @len@.
104 *
105 * It is assumed that the buffer is initially enabled. You
106 * shouldn't be contributing data to a disabled buffer anyway.
107 * However, the buffer handler may at some point disable itself,
108 * and @pkbuf_flush@ can cope with this eventuality. Any
109 * pending data is left at the start of the buffer and can be
110 * flushed out by calling @pkbuf_flush(b, 0, 0)@ if the buffer
111 * is ever re-enabled.
112 */
113
114extern void pkbuf_flush(pkbuf */*pk*/, octet */*p*/, size_t /*len*/);
115
116/* --- @pkbuf_close@ --- *
117 *
118 * Arguments: @pkbuf *pk@ = pointer to buffer block
119 *
120 * Returns: ---
121 *
122 * Use: Informs the client that no more data is likely to arrive. If
123 * there is a partial packet in the buffer, it is discarded.
124 */
125
126extern void pkbuf_close(pkbuf */*pk*/);
127
128/* --- @pkbuf_free@ --- *
129 *
130 * Arguments: @pkbuf *pk@ = pointer to buffer block
131 * @octet **p@ = output pointer to free space
132 *
133 * Returns: Free buffer size.
134 *
135 * Use: Returns the free portion of a packet buffer. Data can then
136 * be written to this portion, and split out into packets by
137 * calling @pkbuf_flush@.
138 */
139
140extern size_t pkbuf_free(pkbuf */*pk*/, octet **/*p*/);
141
142/* --- @pkbuf_snarf@ --- *
143 *
144 * Arguments: @pkbuf *pk@ = pointer to buffer block
145 * @const void *p@ = pointer to input data buffer
146 * @size_t sz@ = size of data in input buffer
147 *
148 * Returns: ---
149 *
150 * Use: Snarfs the data from the input buffer and spits it out as
151 * packets. This interface ignores the complexities of dealing
152 * with disablement: you should be using @pkbuf_free@ to
153 * contribute data if you want to cope with that.
154 */
155
156extern void pkbuf_snarf(pkbuf */*pk*/, const void */*p*/, size_t /*sz*/);
157
158/* --- @pkbuf_want@ --- *
159 *
160 * Arguments: @pkbuf *pk@ = pointer to buffer block
161 * @size_t want@ = how many octets wanted for next packet
162 *
163 * Returns: ---
164 *
165 * Use: Sets the desired size for the next packet to be read. If
166 * it's larger than the current buffer, the buffer is extended.
167 */
168
169extern void pkbuf_want(pkbuf */*pk*/, size_t /*want*/);
170
171/* --- @pkbuf_init@ --- *
172 *
173 * Arguments: @pkbuf *pk@ = pointer to buffer block
0daaeb18 174 * @pkbuf_func *func@ = handler function
436fddaa 175 * @void *p@ = argument pointer for @func@
176 *
177 * Returns: ---
178 *
179 * Use: Initializes a packet buffer block. Any packets are passed to
180 * the provided function for handling.
181 */
182
0daaeb18 183extern void pkbuf_init(pkbuf */*pk*/, pkbuf_func */*func*/, void */*p*/);
436fddaa 184
185/* --- @pkbuf_destroy@ --- *
186 *
187 * Arguments: @pkbuf *pk@ = pointer to buffer block
188 *
189 * Returns: ---
190 *
191 * Use: Deallocates a packet buffer and frees any resources it owned.
192 */
193
194extern void pkbuf_destroy(pkbuf */*pk*/);
195
196/*----- That's all, folks -------------------------------------------------*/
197
198#ifdef __cplusplus
199 }
200#endif
201
202#endif