1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
|
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
* Functions for manipulating fifo buffers (that can grow if needed).
*
* As far as I am concerned, the code I have written for this software
* can be used freely for any purpose. Any derived versions of this
* software must be clearly marked as such, and if the derived work is
* incompatible with the protocol description in the RFC file, it must be
* called by a name other than "ssh" or "Secure Shell".
*/
#include "includes.h"
RCSID("$OpenBSD: buffer.c,v 1.16 2002/06/26 08:54:18 markus Exp $");
#include "xmalloc.h"
#include "buffer.h"
#include "log.h"
/* Initializes the buffer structure. */
void
buffer_init(Buffer *buffer)
{
buffer->alloc = 4096;
buffer->buf = xmalloc(buffer->alloc);
buffer->offset = 0;
buffer->end = 0;
}
/* Frees any memory used for the buffer. */
void
buffer_free(Buffer *buffer)
{
memset(buffer->buf, 0, buffer->alloc);
xfree(buffer->buf);
}
/*
* Clears any data from the buffer, making it empty. This does not actually
* zero the memory.
*/
void
buffer_clear(Buffer *buffer)
{
buffer->offset = 0;
buffer->end = 0;
}
/* Appends data to the buffer, expanding it if necessary. */
void
buffer_append(Buffer *buffer, const void *data, u_int len)
{
void *p;
p = buffer_append_space(buffer, len);
memcpy(p, data, len);
}
/*
* Appends space to the buffer, expanding the buffer if necessary. This does
* not actually copy the data into the buffer, but instead returns a pointer
* to the allocated region.
*/
void *
buffer_append_space(Buffer *buffer, u_int len)
{
void *p;
if (len > 0x100000)
fatal("buffer_append_space: len %u not supported", len);
/* If the buffer is empty, start using it from the beginning. */
if (buffer->offset == buffer->end) {
buffer->offset = 0;
buffer->end = 0;
}
restart:
/* If there is enough space to store all data, store it now. */
if (buffer->end + len < buffer->alloc) {
p = buffer->buf + buffer->end;
buffer->end += len;
return p;
}
/*
* If the buffer is quite empty, but all data is at the end, move the
* data to the beginning and retry.
*/
if (buffer->offset > buffer->alloc / 2) {
memmove(buffer->buf, buffer->buf + buffer->offset,
buffer->end - buffer->offset);
buffer->end -= buffer->offset;
buffer->offset = 0;
goto restart;
}
/* Increase the size of the buffer and retry. */
buffer->alloc += len + 32768;
if (buffer->alloc > 0xa00000)
fatal("buffer_append_space: alloc %u not supported",
buffer->alloc);
buffer->buf = xrealloc(buffer->buf, buffer->alloc);
goto restart;
/* NOTREACHED */
}
/* Returns the number of bytes of data in the buffer. */
u_int
buffer_len(Buffer *buffer)
{
return buffer->end - buffer->offset;
}
/* Gets data from the beginning of the buffer. */
void
buffer_get(Buffer *buffer, void *buf, u_int len)
{
if (len > buffer->end - buffer->offset)
fatal("buffer_get: trying to get more bytes %d than in buffer %d",
len, buffer->end - buffer->offset);
memcpy(buf, buffer->buf + buffer->offset, len);
buffer->offset += len;
}
/* Consumes the given number of bytes from the beginning of the buffer. */
void
buffer_consume(Buffer *buffer, u_int bytes)
{
if (bytes > buffer->end - buffer->offset)
fatal("buffer_consume: trying to get more bytes than in buffer");
buffer->offset += bytes;
}
/* Consumes the given number of bytes from the end of the buffer. */
void
buffer_consume_end(Buffer *buffer, u_int bytes)
{
if (bytes > buffer->end - buffer->offset)
fatal("buffer_consume_end: trying to get more bytes than in buffer");
buffer->end -= bytes;
}
/* Returns a pointer to the first used byte in the buffer. */
void *
buffer_ptr(Buffer *buffer)
{
return buffer->buf + buffer->offset;
}
/* Dumps the contents of the buffer to stderr. */
void
buffer_dump(Buffer *buffer)
{
int i;
u_char *ucp = buffer->buf;
for (i = buffer->offset; i < buffer->end; i++) {
fprintf(stderr, "%02x", ucp[i]);
if ((i-buffer->offset)%16==15)
fprintf(stderr, "\r\n");
else if ((i-buffer->offset)%2==1)
fprintf(stderr, " ");
}
fprintf(stderr, "\r\n");
}
|
