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
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
|
/* Copyright 2004 Roger Dingledine */
/* See LICENSE for licensing information */
/* $Id$ */
/**
* \file torgzip.c
*
* \brief Simple in-memory gzip implementation.
**/
#include "orconfig.h"
#include <stdlib.h>
#include <stdio.h>
#include <assert.h>
#include <zlib.h>
#include "util.h"
#include "log.h"
#include "torgzip.h"
static int gzip_is_supported = -1;
int
is_gzip_supported(void)
{
if (gzip_is_supported >= 0)
return gzip_is_supported;
if (!strcmpstart(ZLIB_VERSION, "0.") ||
!strcmpstart(ZLIB_VERSION, "1.0") ||
!strcmpstart(ZLIB_VERSION, "1.1"))
gzip_is_supported = 0;
else
gzip_is_supported = 1;
return gzip_is_supported;
}
static INLINE int
method_bits(compress_method_t method)
{
/* Bits+16 means "use gzip" in zlib >= 1.2 */
return method == GZIP_METHOD ? 15+16 : 15;
}
int
tor_gzip_compress(char **out, size_t *out_len,
const char *in, size_t in_len,
compress_method_t method)
{
struct z_stream_s *stream = NULL;
size_t out_size;
off_t offset;
tor_assert(out && out_len && in);
if (method == GZIP_METHOD && !is_gzip_supported()) {
/* Old zlib version don't support gzip in deflateInit2 */
log_fn(LOG_WARN, "Gzip not supported with zlib %s", ZLIB_VERSION);
return -1;
}
*out = NULL;
stream = tor_malloc_zero(sizeof(struct z_stream_s));
stream->zalloc = Z_NULL;
stream->zfree = Z_NULL;
stream->opaque = NULL;
stream->next_in = (unsigned char*) in;
stream->avail_in = in_len;
if (deflateInit2(stream, Z_BEST_COMPRESSION, Z_DEFLATED,
method_bits(method),
8, Z_DEFAULT_STRATEGY) != Z_OK) {
log_fn(LOG_WARN, "Error from deflateInit2: %s",
stream->msg?stream->msg:"<no message>");
goto err;
}
/* Guess 50% compression. */
out_size = in_len / 2;
if (out_size < 1024) out_size = 1024;
*out = tor_malloc(out_size);
stream->next_out = *out;
stream->avail_out = out_size;
while (1) {
switch (deflate(stream, Z_FINISH))
{
case Z_STREAM_END:
goto done;
case Z_OK:
/* In case zlib doesn't work as I think .... */
if (stream->avail_out >= stream->avail_in+16)
break;
case Z_BUF_ERROR:
offset = stream->next_out - ((unsigned char*)*out);
out_size *= 2;
*out = tor_realloc(*out, out_size);
stream->next_out = *out + offset;
stream->avail_out = out_size - offset;
break;
default:
log_fn(LOG_WARN, "Gzip compression didn't finish: %s",
stream->msg ? stream->msg : "<no message>");
goto err;
}
}
done:
*out_len = stream->total_out;
if (deflateEnd(stream)!=Z_OK) {
log_fn(LOG_WARN, "Error freeing gzip structures");
goto err;
}
tor_free(stream);
return 0;
err:
if (stream) {
deflateEnd(stream);
tor_free(stream);
}
if (*out) {
tor_free(*out);
}
return -1;
}
int
tor_gzip_uncompress(char **out, size_t *out_len,
const char *in, size_t in_len,
compress_method_t method)
{
struct z_stream_s *stream = NULL;
size_t out_size;
off_t offset;
tor_assert(out && out_len && in);
if (method == GZIP_METHOD && !is_gzip_supported()) {
/* Old zlib version don't support gzip in inflateInit2 */
log_fn(LOG_WARN, "Gzip not supported with zlib %s", ZLIB_VERSION);
return -1;
}
*out = NULL;
stream = tor_malloc_zero(sizeof(struct z_stream_s));
stream->zalloc = Z_NULL;
stream->zfree = Z_NULL;
stream->opaque = NULL;
stream->next_in = (unsigned char*) in;
stream->avail_in = in_len;
if (inflateInit2(stream,
method_bits(method)) != Z_OK) {
log_fn(LOG_WARN, "Error from inflateInit2: %s",
stream->msg?stream->msg:"<no message>");
goto err;
}
out_size = in_len * 2; /* guess 50% compression. */
if (out_size < 1024) out_size = 1024;
*out = tor_malloc(out_size);
stream->next_out = *out;
stream->avail_out = out_size;
while (1) {
switch(inflate(stream, Z_FINISH))
{
case Z_STREAM_END:
goto done;
case Z_OK:
/* In case zlib doesn't work as I think.... */
if (stream->avail_out >= stream->avail_in+16)
break;
case Z_BUF_ERROR:
offset = stream->next_out - ((unsigned char*)*out);
out_size *= 2;
*out = tor_realloc(*out, out_size);
stream->next_out = *out + offset;
stream->avail_out = out_size - offset;
break;
default:
log_fn(LOG_WARN, "Gzip decompression returned an error: %s",
stream->msg ? stream->msg : "<no message>");
goto err;
}
}
done:
*out_len = stream->total_out;
if (inflateEnd(stream)!=Z_OK) {
log_fn(LOG_WARN, "Error freeing gzip structures");
goto err;
}
tor_free(stream);
/* NUL-terminate output. */
if (out_size == *out_len)
*out = tor_realloc(*out, out_size + 1);
(*out)[*out_len] = '\0';
return 0;
err:
if (stream) {
inflateEnd(stream);
tor_free(stream);
}
if (*out) {
tor_free(*out);
}
return -1;
}
/*
Local Variables:
mode:c
indent-tabs-mode:nil
c-basic-offset:2
End:
*/
|