summaryrefslogtreecommitdiff
path: root/src/gunzip.c
blob: 944132e0cfc5eb3ab4f19f982c99ef3c094e0cc2 (plain) (blame)
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
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
/* gunzip.c - Alpine Package Keeper (APK)
 *
 * Copyright (C) 2008-2011 Timo Teräs <timo.teras@iki.fi>
 * All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published
 * by the Free Software Foundation. See http://www.gnu.org/ for details.
 */

#include <errno.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <malloc.h>
#include <zlib.h>

#include "apk_defines.h"
#include "apk_io.h"

struct apk_gzip_istream {
	struct apk_istream is;
	struct apk_bstream *bs;
	z_stream zs;
	int err;

	apk_multipart_cb cb;
	void *cbctx;
	void *cbprev;
	apk_blob_t cbarg;
};

static ssize_t gzi_read(void *stream, void *ptr, size_t size)
{
	struct apk_gzip_istream *gis =
		container_of(stream, struct apk_gzip_istream, is);
	int r;

	if (gis->err != 0) {
		if (gis->err > 0)
			return 0;
		return gis->err;
	}

	if (ptr == NULL)
		return apk_istream_skip(&gis->is, size);

	gis->zs.avail_out = size;
	gis->zs.next_out  = ptr;

	while (gis->zs.avail_out != 0 && gis->err == 0) {
		if (!APK_BLOB_IS_NULL(gis->cbarg)) {
			r = gis->cb(gis->cbctx,
				    gis->err ? APK_MPART_END : APK_MPART_BOUNDARY,
				    gis->cbarg);
			if (r > 0)
				r = -ECANCELED;
			if (r != 0) {
				gis->err = r;
				goto ret;
			}
			gis->cbarg = APK_BLOB_NULL;
		}
		if (gis->zs.avail_in == 0) {
			apk_blob_t blob;

			if (gis->cb != NULL && gis->cbprev != NULL &&
			    gis->cbprev != gis->zs.next_in) {
				gis->cb(gis->cbctx, APK_MPART_DATA,
					APK_BLOB_PTR_LEN(gis->cbprev,
					(void *)gis->zs.next_in - gis->cbprev));
			}
			blob = gis->bs->read(gis->bs, APK_BLOB_NULL);
			gis->cbprev = blob.ptr;
			gis->zs.avail_in = blob.len;
			gis->zs.next_in = (void *) gis->cbprev;
			if (blob.len < 0) {
				gis->err = blob.len;
				goto ret;
			} else if (gis->zs.avail_in == 0) {
				gis->err = 1;
				if (gis->cb != NULL) {
					r = gis->cb(gis->cbctx, APK_MPART_END,
						    APK_BLOB_NULL);
					if (r > 0)
						r = -ECANCELED;
					if (r != 0)
						gis->err = r;
				}
				goto ret;
			}
		}

		r = inflate(&gis->zs, Z_NO_FLUSH);
		switch (r) {
		case Z_STREAM_END:
			/* Digest the inflated bytes */
			if ((gis->bs->flags & APK_BSTREAM_EOF) &&
			    gis->zs.avail_in == 0)
				gis->err = 1;
			if (gis->cb != NULL) {
				gis->cbarg = APK_BLOB_PTR_LEN(gis->cbprev, (void *) gis->zs.next_in - gis->cbprev); 
				gis->cbprev = gis->zs.next_in;
			}
			/* If we hit end of the bitstream (not end
			 * of just this gzip), we need to do the
			 * callback here, as we won't be called again.
			 * For boundaries it should be postponed to not
			 * be called until next gzip read is started. */
			if (gis->err) {
				r = gis->cb(gis->cbctx,
					    gis->err ? APK_MPART_END : APK_MPART_BOUNDARY,
					    gis->cbarg);
				if (r > 0)
					r = -ECANCELED;
				goto ret;
			}
			inflateEnd(&gis->zs);
			if (inflateInit2(&gis->zs, 15+32) != Z_OK)
				return -ENOMEM;
			break;
		case Z_OK:
			break;
		default:
			gis->err = -EIO;
			break;
		}
	}

ret:
	if (size - gis->zs.avail_out == 0)
		return gis->err < 0 ? gis->err : 0;

	return size - gis->zs.avail_out;
}

static void gzi_close(void *stream)
{
	struct apk_gzip_istream *gis =
		container_of(stream, struct apk_gzip_istream, is);

	inflateEnd(&gis->zs);
	gis->bs->close(gis->bs, NULL);
	free(gis);
}

struct apk_istream *apk_bstream_gunzip_mpart(struct apk_bstream *bs,
					     apk_multipart_cb cb, void *ctx)
{
	struct apk_gzip_istream *gis;

	if (!bs) return NULL;

	gis = malloc(sizeof(struct apk_gzip_istream));
	if (!gis) goto err;

	*gis = (struct apk_gzip_istream) {
		.is.read = gzi_read,
		.is.close = gzi_close,
		.bs = bs,
		.cb = cb,
		.cbctx = ctx,
	};

	if (inflateInit2(&gis->zs, 15+32) != Z_OK) {
		free(gis);
		goto err;
	}

	return &gis->is;
err:
	bs->close(bs, NULL);
	return NULL;
}

struct apk_gzip_ostream {
	struct apk_ostream os;
	struct apk_ostream *output;
	z_stream zs;
};

static ssize_t gzo_write(void *stream, const void *ptr, size_t size)
{
	struct apk_gzip_ostream *gos = (struct apk_gzip_ostream *) stream;
	unsigned char buffer[1024];
	ssize_t have, r;

	gos->zs.avail_in = size;
	gos->zs.next_in = (void *) ptr;
	while (gos->zs.avail_in) {
		gos->zs.avail_out = sizeof(buffer);
		gos->zs.next_out = buffer;
		r = deflate(&gos->zs, Z_NO_FLUSH);
		if (r == Z_STREAM_ERROR)
			return -EIO;
		have = sizeof(buffer) - gos->zs.avail_out;
		if (have != 0) {
			r = gos->output->write(gos->output, buffer, have);
			if (r != have)
				return -EIO;
		}
	}

	return size;
}

static int gzo_close(void *stream)
{
	struct apk_gzip_ostream *gos = (struct apk_gzip_ostream *) stream;
	unsigned char buffer[1024];
	size_t have;
	int r, rc = 0;

	do {
		gos->zs.avail_out = sizeof(buffer);
		gos->zs.next_out = buffer;
		r = deflate(&gos->zs, Z_FINISH);
		have = sizeof(buffer) - gos->zs.avail_out;
		if (gos->output->write(gos->output, buffer, have) != have)
			rc = -EIO;
	} while (r == Z_OK);
	r = gos->output->close(gos->output);
	if (r != 0)
		rc = r;

	deflateEnd(&gos->zs);
	free(stream);

	return rc;
}

struct apk_ostream *apk_ostream_gzip(struct apk_ostream *output)
{
	struct apk_gzip_ostream *gos;

	if (output == NULL)
		return NULL;

	gos = malloc(sizeof(struct apk_gzip_ostream));
	if (gos == NULL)
		goto err;

	*gos = (struct apk_gzip_ostream) {
		.os.write = gzo_write,
		.os.close = gzo_close,
		.output = output,
	};

	if (deflateInit2(&gos->zs, 9, Z_DEFLATED, 15 | 16, 8,
			 Z_DEFAULT_STRATEGY) != Z_OK) {
		free(gos);
		goto err;
	}

	return &gos->os;
err:
	output->close(output);
	return NULL;
}