aboutsummaryrefslogtreecommitdiff
path: root/archive-zip.c
blob: 3cbf6bb8ac4045803140ca5019126015e817155e (plain)
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
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
/*
 * Copyright (c) 2006 Rene Scharfe
 */
#include "cache.h"
#include "commit.h"
#include "blob.h"
#include "tree.h"
#include "quote.h"
#include "builtin.h"
#include "archive.h"

static int verbose;
static int zip_date;
static int zip_time;

static unsigned char *zip_dir;
static unsigned int zip_dir_size;

static unsigned int zip_offset;
static unsigned int zip_dir_offset;
static unsigned int zip_dir_entries;

#define ZIP_DIRECTORY_MIN_SIZE	(1024 * 1024)

struct zip_local_header {
	unsigned char magic[4];
	unsigned char version[2];
	unsigned char flags[2];
	unsigned char compression_method[2];
	unsigned char mtime[2];
	unsigned char mdate[2];
	unsigned char crc32[4];
	unsigned char compressed_size[4];
	unsigned char size[4];
	unsigned char filename_length[2];
	unsigned char extra_length[2];
	unsigned char _end[1];
};

struct zip_dir_header {
	unsigned char magic[4];
	unsigned char creator_version[2];
	unsigned char version[2];
	unsigned char flags[2];
	unsigned char compression_method[2];
	unsigned char mtime[2];
	unsigned char mdate[2];
	unsigned char crc32[4];
	unsigned char compressed_size[4];
	unsigned char size[4];
	unsigned char filename_length[2];
	unsigned char extra_length[2];
	unsigned char comment_length[2];
	unsigned char disk[2];
	unsigned char attr1[2];
	unsigned char attr2[4];
	unsigned char offset[4];
	unsigned char _end[1];
};

struct zip_dir_trailer {
	unsigned char magic[4];
	unsigned char disk[2];
	unsigned char directory_start_disk[2];
	unsigned char entries_on_this_disk[2];
	unsigned char entries[2];
	unsigned char size[4];
	unsigned char offset[4];
	unsigned char comment_length[2];
	unsigned char _end[1];
};

/*
 * On ARM, padding is added at the end of the struct, so a simple
 * sizeof(struct ...) reports two bytes more than the payload size
 * we're interested in.
 */
#define ZIP_LOCAL_HEADER_SIZE	offsetof(struct zip_local_header, _end)
#define ZIP_DIR_HEADER_SIZE	offsetof(struct zip_dir_header, _end)
#define ZIP_DIR_TRAILER_SIZE	offsetof(struct zip_dir_trailer, _end)

static void copy_le16(unsigned char *dest, unsigned int n)
{
	dest[0] = 0xff & n;
	dest[1] = 0xff & (n >> 010);
}

static void copy_le32(unsigned char *dest, unsigned int n)
{
	dest[0] = 0xff & n;
	dest[1] = 0xff & (n >> 010);
	dest[2] = 0xff & (n >> 020);
	dest[3] = 0xff & (n >> 030);
}

static void *zlib_deflate(void *data, unsigned long size,
                          unsigned long *compressed_size)
{
	z_stream stream;
	unsigned long maxsize;
	void *buffer;
	int result;

	memset(&stream, 0, sizeof(stream));
	deflateInit(&stream, zlib_compression_level);
	maxsize = deflateBound(&stream, size);
	buffer = xmalloc(maxsize);

	stream.next_in = data;
	stream.avail_in = size;
	stream.next_out = buffer;
	stream.avail_out = maxsize;

	do {
		result = deflate(&stream, Z_FINISH);
	} while (result == Z_OK);

	if (result != Z_STREAM_END) {
		free(buffer);
		return NULL;
	}

	deflateEnd(&stream);
	*compressed_size = stream.total_out;

	return buffer;
}

static char *construct_path(const char *base, int baselen,
                            const char *filename, int isdir, int *pathlen)
{
	int filenamelen = strlen(filename);
	int len = baselen + filenamelen;
	char *path, *p;

	if (isdir)
		len++;
	p = path = xmalloc(len + 1);

	memcpy(p, base, baselen);
	p += baselen;
	memcpy(p, filename, filenamelen);
	p += filenamelen;
	if (isdir)
		*p++ = '/';
	*p = '\0';

	*pathlen = len;

	return path;
}

static int write_zip_entry(const unsigned char *sha1,
                           const char *base, int baselen,
                           const char *filename, unsigned mode, int stage)
{
	struct zip_local_header header;
	struct zip_dir_header dirent;
	unsigned long attr2;
	unsigned long compressed_size;
	unsigned long uncompressed_size;
	unsigned long crc;
	unsigned long direntsize;
	unsigned long size;
	int method;
	int result = -1;
	int pathlen;
	unsigned char *out;
	char *path;
	enum object_type type;
	void *buffer = NULL;
	void *deflated = NULL;

	crc = crc32(0, NULL, 0);

	path = construct_path(base, baselen, filename, S_ISDIR(mode), &pathlen);
	if (verbose)
		fprintf(stderr, "%s\n", path);
	if (pathlen > 0xffff) {
		error("path too long (%d chars, SHA1: %s): %s", pathlen,
		      sha1_to_hex(sha1), path);
		goto out;
	}

	if (S_ISDIR(mode) || S_ISDIRLNK(mode)) {
		method = 0;
		attr2 = 16;
		result = (S_ISDIR(mode) ? READ_TREE_RECURSIVE : 0);
		out = NULL;
		uncompressed_size = 0;
		compressed_size = 0;
	} else if (S_ISREG(mode) || S_ISLNK(mode)) {
		method = 0;
		attr2 = S_ISLNK(mode) ? ((mode | 0777) << 16) : 0;
		if (S_ISREG(mode) && zlib_compression_level != 0)
			method = 8;
		result = 0;
		buffer = convert_sha1_file(path, sha1, mode, &type, &size);
		if (!buffer)
			die("cannot read %s", sha1_to_hex(sha1));
		crc = crc32(crc, buffer, size);
		out = buffer;
		uncompressed_size = size;
		compressed_size = size;
	} else {
		error("unsupported file mode: 0%o (SHA1: %s)", mode,
		      sha1_to_hex(sha1));
		goto out;
	}

	if (method == 8) {
		deflated = zlib_deflate(buffer, size, &compressed_size);
		if (deflated && compressed_size - 6 < size) {
			/* ZLIB --> raw compressed data (see RFC 1950) */
			/* CMF and FLG ... */
			out = (unsigned char *)deflated + 2;
			compressed_size -= 6;	/* ... and ADLER32 */
		} else {
			method = 0;
			compressed_size = size;
		}
	}

	/* make sure we have enough free space in the dictionary */
	direntsize = ZIP_DIR_HEADER_SIZE + pathlen;
	while (zip_dir_size < zip_dir_offset + direntsize) {
		zip_dir_size += ZIP_DIRECTORY_MIN_SIZE;
		zip_dir = xrealloc(zip_dir, zip_dir_size);
	}

	copy_le32(dirent.magic, 0x02014b50);
	copy_le16(dirent.creator_version, S_ISLNK(mode) ? 0x0317 : 0);
	copy_le16(dirent.version, 10);
	copy_le16(dirent.flags, 0);
	copy_le16(dirent.compression_method, method);
	copy_le16(dirent.mtime, zip_time);
	copy_le16(dirent.mdate, zip_date);
	copy_le32(dirent.crc32, crc);
	copy_le32(dirent.compressed_size, compressed_size);
	copy_le32(dirent.size, uncompressed_size);
	copy_le16(dirent.filename_length, pathlen);
	copy_le16(dirent.extra_length, 0);
	copy_le16(dirent.comment_length, 0);
	copy_le16(dirent.disk, 0);
	copy_le16(dirent.attr1, 0);
	copy_le32(dirent.attr2, attr2);
	copy_le32(dirent.offset, zip_offset);
	memcpy(zip_dir + zip_dir_offset, &dirent, ZIP_DIR_HEADER_SIZE);
	zip_dir_offset += ZIP_DIR_HEADER_SIZE;
	memcpy(zip_dir + zip_dir_offset, path, pathlen);
	zip_dir_offset += pathlen;
	zip_dir_entries++;

	copy_le32(header.magic, 0x04034b50);
	copy_le16(header.version, 10);
	copy_le16(header.flags, 0);
	copy_le16(header.compression_method, method);
	copy_le16(header.mtime, zip_time);
	copy_le16(header.mdate, zip_date);
	copy_le32(header.crc32, crc);
	copy_le32(header.compressed_size, compressed_size);
	copy_le32(header.size, uncompressed_size);
	copy_le16(header.filename_length, pathlen);
	copy_le16(header.extra_length, 0);
	write_or_die(1, &header, ZIP_LOCAL_HEADER_SIZE);
	zip_offset += ZIP_LOCAL_HEADER_SIZE;
	write_or_die(1, path, pathlen);
	zip_offset += pathlen;
	if (compressed_size > 0) {
		write_or_die(1, out, compressed_size);
		zip_offset += compressed_size;
	}

out:
	free(buffer);
	free(deflated);
	free(path);

	return result;
}

static void write_zip_trailer(const unsigned char *sha1)
{
	struct zip_dir_trailer trailer;

	copy_le32(trailer.magic, 0x06054b50);
	copy_le16(trailer.disk, 0);
	copy_le16(trailer.directory_start_disk, 0);
	copy_le16(trailer.entries_on_this_disk, zip_dir_entries);
	copy_le16(trailer.entries, zip_dir_entries);
	copy_le32(trailer.size, zip_dir_offset);
	copy_le32(trailer.offset, zip_offset);
	copy_le16(trailer.comment_length, sha1 ? 40 : 0);

	write_or_die(1, zip_dir, zip_dir_offset);
	write_or_die(1, &trailer, ZIP_DIR_TRAILER_SIZE);
	if (sha1)
		write_or_die(1, sha1_to_hex(sha1), 40);
}

static void dos_time(time_t *time, int *dos_date, int *dos_time)
{
	struct tm *t = localtime(time);

	*dos_date = t->tm_mday + (t->tm_mon + 1) * 32 +
	            (t->tm_year + 1900 - 1980) * 512;
	*dos_time = t->tm_sec / 2 + t->tm_min * 32 + t->tm_hour * 2048;
}

int write_zip_archive(struct archiver_args *args)
{
	int plen = strlen(args->base);

	dos_time(&args->time, &zip_date, &zip_time);

	zip_dir = xmalloc(ZIP_DIRECTORY_MIN_SIZE);
	zip_dir_size = ZIP_DIRECTORY_MIN_SIZE;
	verbose = args->verbose;

	if (args->base && plen > 0 && args->base[plen - 1] == '/') {
		char *base = xstrdup(args->base);
		int baselen = strlen(base);

		while (baselen > 0 && base[baselen - 1] == '/')
			base[--baselen] = '\0';
		write_zip_entry(args->tree->object.sha1, "", 0, base, 040777, 0);
		free(base);
	}
	read_tree_recursive(args->tree, args->base, plen, 0,
			    args->pathspec, write_zip_entry);
	write_zip_trailer(args->commit_sha1);

	free(zip_dir);

	return 0;
}

void *parse_extra_zip_args(int argc, const char **argv)
{
	for (; argc > 0; argc--, argv++) {
		const char *arg = argv[0];

		if (arg[0] == '-' && isdigit(arg[1]) && arg[2] == '\0')
			zlib_compression_level = arg[1] - '0';
		else
			die("Unknown argument for zip format: %s", arg);
	}
	return NULL;
}