Mercurial > dropbear

comparison circbuffer.c @ 108:10f4d3319780

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- added circular buffering for channels - added stderr support for the client - cleaned up a bunch of "unused" warnings, duplicated header definitions - added exit-status support for the client
author Matt Johnston <matt@ucc.asn.au>
date Thu, 26 Aug 2004 13:16:40 +0000
parents
children 0cfba3034be5
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107:d3eb1fa8484e 108:10f4d3319780
1 /*
2 * Dropbear SSH
3 *
4 * Copyright (c) 2002-2004 Matt Johnston
5 * All rights reserved.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
20 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
23 * SOFTWARE. */
24
25 #include "includes.h"
26 #include "dbutil.h"
27 #include "circbuffer.h"
28
29 #define MAX_CBUF_SIZE 100000000
30
31 circbuffer * cbuf_new(unsigned int size) {
32
33 circbuffer *cbuf = NULL;
34
35 if (size > MAX_CBUF_SIZE) {
36 dropbear_exit("bad cbuf size");
37 }
38
39 cbuf = (circbuffer*)m_malloc(sizeof(circbuffer));
40 cbuf->data = (unsigned char*)m_malloc(size);
41 cbuf->used = 0;
42 cbuf->readpos = 0;
43 cbuf->writepos = 0;
44 cbuf->size = size;
45
46 return cbuf;
47 }
48
49 void cbuf_free(circbuffer * cbuf) {
50
51 m_free(cbuf->data);
52 m_free(cbuf);
53 }
54
55 unsigned int cbuf_getused(circbuffer * cbuf) {
56
57 return cbuf->used;
58
59 }
60
61 unsigned int cbuf_getavail(circbuffer * cbuf) {
62
63 return cbuf->size - cbuf->used;
64
65 }
66
67 unsigned int cbuf_readlen(circbuffer *cbuf) {
68
69 assert(((2*cbuf->size)+cbuf->writepos-cbuf->readpos)%cbuf->size == cbuf->used%cbuf->size);
70 assert(((2*cbuf->size)+cbuf->readpos-cbuf->writepos)%cbuf->size == (cbuf->size-cbuf->used)%cbuf->size);
71
72 if (cbuf->used == 0) {
73 TRACE(("cbuf_readlen: unused buffer"));
74 return 0;
75 }
76
77 if (cbuf->readpos < cbuf->writepos) {
78 return cbuf->writepos - cbuf->readpos;
79 }
80
81 return cbuf->size - cbuf->readpos;
82 }
83
84 unsigned int cbuf_writelen(circbuffer *cbuf) {
85
86 assert(cbuf->used <= cbuf->size);
87 assert(((2*cbuf->size)+cbuf->writepos-cbuf->readpos)%cbuf->size == cbuf->used%cbuf->size);
88 assert(((2*cbuf->size)+cbuf->readpos-cbuf->writepos)%cbuf->size == (cbuf->size-cbuf->used)%cbuf->size);
89
90 if (cbuf->used == cbuf->size) {
91 TRACE(("cbuf_writelen: full buffer"));
92 return 0; /* full */
93 }
94
95 if (cbuf->writepos < cbuf->readpos) {
96 return cbuf->readpos - cbuf->writepos;
97 }
98
99 return cbuf->size - cbuf->writepos;
100 }
101
102 unsigned char* cbuf_readptr(circbuffer *cbuf, unsigned int len) {
103 if (len > cbuf_readlen(cbuf)) {
104 dropbear_exit("bad cbuf read");
105 }
106
107 return &cbuf->data[cbuf->readpos];
108 }
109
110 unsigned char* cbuf_writeptr(circbuffer *cbuf, unsigned int len) {
111
112 if (len > cbuf_writelen(cbuf)) {
113 dropbear_exit("bad cbuf write");
114 }
115
116 return &cbuf->data[cbuf->writepos];
117 }
118
119 void cbuf_incrwrite(circbuffer *cbuf, unsigned int len) {
120 if (len > cbuf_writelen(cbuf)) {
121 dropbear_exit("bad cbuf write");
122 }
123
124 cbuf->used += len;
125 assert(cbuf->used <= cbuf->size);
126 cbuf->writepos = (cbuf->writepos + len) % cbuf->size;
127 }
128
129
130 void cbuf_incrread(circbuffer *cbuf, unsigned int len) {
131 if (len > cbuf_readlen(cbuf)) {
132 dropbear_exit("bad cbuf read");
133 }
134
135 assert(cbuf->used >= len);
136 cbuf->used -= len;
137 cbuf->readpos = (cbuf->readpos + len) % cbuf->size;
138 }