Merge branch 'en/merge-recursive-oid-eq-simplify'
[git] / archive-zip.c
1 /*
2  * Copyright (c) 2006 Rene Scharfe
3  */
4 #include "cache.h"
5 #include "config.h"
6 #include "archive.h"
7 #include "streaming.h"
8 #include "utf8.h"
9 #include "object-store.h"
10 #include "userdiff.h"
11 #include "xdiff-interface.h"
12
13 static int zip_date;
14 static int zip_time;
15
16 /* We only care about the "buf" part here. */
17 static struct strbuf zip_dir;
18
19 static uintmax_t zip_offset;
20 static uint64_t zip_dir_entries;
21
22 static unsigned int max_creator_version;
23
24 #define ZIP_STREAM      (1 <<  3)
25 #define ZIP_UTF8        (1 << 11)
26
27 enum zip_method {
28         ZIP_METHOD_STORE = 0,
29         ZIP_METHOD_DEFLATE = 8
30 };
31
32 struct zip_local_header {
33         unsigned char magic[4];
34         unsigned char version[2];
35         unsigned char flags[2];
36         unsigned char compression_method[2];
37         unsigned char mtime[2];
38         unsigned char mdate[2];
39         unsigned char crc32[4];
40         unsigned char compressed_size[4];
41         unsigned char size[4];
42         unsigned char filename_length[2];
43         unsigned char extra_length[2];
44         unsigned char _end[1];
45 };
46
47 struct zip_data_desc {
48         unsigned char magic[4];
49         unsigned char crc32[4];
50         unsigned char compressed_size[4];
51         unsigned char size[4];
52         unsigned char _end[1];
53 };
54
55 struct zip64_data_desc {
56         unsigned char magic[4];
57         unsigned char crc32[4];
58         unsigned char compressed_size[8];
59         unsigned char size[8];
60         unsigned char _end[1];
61 };
62
63 struct zip_dir_trailer {
64         unsigned char magic[4];
65         unsigned char disk[2];
66         unsigned char directory_start_disk[2];
67         unsigned char entries_on_this_disk[2];
68         unsigned char entries[2];
69         unsigned char size[4];
70         unsigned char offset[4];
71         unsigned char comment_length[2];
72         unsigned char _end[1];
73 };
74
75 struct zip_extra_mtime {
76         unsigned char magic[2];
77         unsigned char extra_size[2];
78         unsigned char flags[1];
79         unsigned char mtime[4];
80         unsigned char _end[1];
81 };
82
83 struct zip64_extra {
84         unsigned char magic[2];
85         unsigned char extra_size[2];
86         unsigned char size[8];
87         unsigned char compressed_size[8];
88         unsigned char _end[1];
89 };
90
91 struct zip64_dir_trailer {
92         unsigned char magic[4];
93         unsigned char record_size[8];
94         unsigned char creator_version[2];
95         unsigned char version[2];
96         unsigned char disk[4];
97         unsigned char directory_start_disk[4];
98         unsigned char entries_on_this_disk[8];
99         unsigned char entries[8];
100         unsigned char size[8];
101         unsigned char offset[8];
102         unsigned char _end[1];
103 };
104
105 struct zip64_dir_trailer_locator {
106         unsigned char magic[4];
107         unsigned char disk[4];
108         unsigned char offset[8];
109         unsigned char number_of_disks[4];
110         unsigned char _end[1];
111 };
112
113 /*
114  * On ARM, padding is added at the end of the struct, so a simple
115  * sizeof(struct ...) reports two bytes more than the payload size
116  * we're interested in.
117  */
118 #define ZIP_LOCAL_HEADER_SIZE   offsetof(struct zip_local_header, _end)
119 #define ZIP_DATA_DESC_SIZE      offsetof(struct zip_data_desc, _end)
120 #define ZIP64_DATA_DESC_SIZE    offsetof(struct zip64_data_desc, _end)
121 #define ZIP_DIR_HEADER_SIZE     offsetof(struct zip_dir_header, _end)
122 #define ZIP_DIR_TRAILER_SIZE    offsetof(struct zip_dir_trailer, _end)
123 #define ZIP_EXTRA_MTIME_SIZE    offsetof(struct zip_extra_mtime, _end)
124 #define ZIP_EXTRA_MTIME_PAYLOAD_SIZE \
125         (ZIP_EXTRA_MTIME_SIZE - offsetof(struct zip_extra_mtime, flags))
126 #define ZIP64_EXTRA_SIZE        offsetof(struct zip64_extra, _end)
127 #define ZIP64_EXTRA_PAYLOAD_SIZE \
128         (ZIP64_EXTRA_SIZE - offsetof(struct zip64_extra, size))
129 #define ZIP64_DIR_TRAILER_SIZE  offsetof(struct zip64_dir_trailer, _end)
130 #define ZIP64_DIR_TRAILER_RECORD_SIZE \
131         (ZIP64_DIR_TRAILER_SIZE - \
132          offsetof(struct zip64_dir_trailer, creator_version))
133 #define ZIP64_DIR_TRAILER_LOCATOR_SIZE \
134         offsetof(struct zip64_dir_trailer_locator, _end)
135
136 static void copy_le16(unsigned char *dest, unsigned int n)
137 {
138         dest[0] = 0xff & n;
139         dest[1] = 0xff & (n >> 010);
140 }
141
142 static void copy_le32(unsigned char *dest, unsigned int n)
143 {
144         dest[0] = 0xff & n;
145         dest[1] = 0xff & (n >> 010);
146         dest[2] = 0xff & (n >> 020);
147         dest[3] = 0xff & (n >> 030);
148 }
149
150 static void copy_le64(unsigned char *dest, uint64_t n)
151 {
152         dest[0] = 0xff & n;
153         dest[1] = 0xff & (n >> 010);
154         dest[2] = 0xff & (n >> 020);
155         dest[3] = 0xff & (n >> 030);
156         dest[4] = 0xff & (n >> 040);
157         dest[5] = 0xff & (n >> 050);
158         dest[6] = 0xff & (n >> 060);
159         dest[7] = 0xff & (n >> 070);
160 }
161
162 static uint64_t clamp_max(uint64_t n, uint64_t max, int *clamped)
163 {
164         if (n <= max)
165                 return n;
166         *clamped = 1;
167         return max;
168 }
169
170 static void copy_le16_clamp(unsigned char *dest, uint64_t n, int *clamped)
171 {
172         copy_le16(dest, clamp_max(n, 0xffff, clamped));
173 }
174
175 static void copy_le32_clamp(unsigned char *dest, uint64_t n, int *clamped)
176 {
177         copy_le32(dest, clamp_max(n, 0xffffffff, clamped));
178 }
179
180 static int strbuf_add_le(struct strbuf *sb, size_t size, uintmax_t n)
181 {
182         while (size-- > 0) {
183                 strbuf_addch(sb, n & 0xff);
184                 n >>= 8;
185         }
186         return -!!n;
187 }
188
189 static uint32_t clamp32(uintmax_t n)
190 {
191         const uintmax_t max = 0xffffffff;
192         return (n < max) ? n : max;
193 }
194
195 static void *zlib_deflate_raw(void *data, unsigned long size,
196                               int compression_level,
197                               unsigned long *compressed_size)
198 {
199         git_zstream stream;
200         unsigned long maxsize;
201         void *buffer;
202         int result;
203
204         git_deflate_init_raw(&stream, compression_level);
205         maxsize = git_deflate_bound(&stream, size);
206         buffer = xmalloc(maxsize);
207
208         stream.next_in = data;
209         stream.avail_in = size;
210         stream.next_out = buffer;
211         stream.avail_out = maxsize;
212
213         do {
214                 result = git_deflate(&stream, Z_FINISH);
215         } while (result == Z_OK);
216
217         if (result != Z_STREAM_END) {
218                 free(buffer);
219                 return NULL;
220         }
221
222         git_deflate_end(&stream);
223         *compressed_size = stream.total_out;
224
225         return buffer;
226 }
227
228 static void write_zip_data_desc(unsigned long size,
229                                 unsigned long compressed_size,
230                                 unsigned long crc)
231 {
232         if (size >= 0xffffffff || compressed_size >= 0xffffffff) {
233                 struct zip64_data_desc trailer;
234                 copy_le32(trailer.magic, 0x08074b50);
235                 copy_le32(trailer.crc32, crc);
236                 copy_le64(trailer.compressed_size, compressed_size);
237                 copy_le64(trailer.size, size);
238                 write_or_die(1, &trailer, ZIP64_DATA_DESC_SIZE);
239                 zip_offset += ZIP64_DATA_DESC_SIZE;
240         } else {
241                 struct zip_data_desc trailer;
242                 copy_le32(trailer.magic, 0x08074b50);
243                 copy_le32(trailer.crc32, crc);
244                 copy_le32(trailer.compressed_size, compressed_size);
245                 copy_le32(trailer.size, size);
246                 write_or_die(1, &trailer, ZIP_DATA_DESC_SIZE);
247                 zip_offset += ZIP_DATA_DESC_SIZE;
248         }
249 }
250
251 static void set_zip_header_data_desc(struct zip_local_header *header,
252                                      unsigned long size,
253                                      unsigned long compressed_size,
254                                      unsigned long crc)
255 {
256         copy_le32(header->crc32, crc);
257         copy_le32(header->compressed_size, compressed_size);
258         copy_le32(header->size, size);
259 }
260
261 static int has_only_ascii(const char *s)
262 {
263         for (;;) {
264                 int c = *s++;
265                 if (c == '\0')
266                         return 1;
267                 if (!isascii(c))
268                         return 0;
269         }
270 }
271
272 static int entry_is_binary(struct index_state *istate, const char *path,
273                            const void *buffer, size_t size)
274 {
275         struct userdiff_driver *driver = userdiff_find_by_path(istate, path);
276         if (!driver)
277                 driver = userdiff_find_by_name("default");
278         if (driver->binary != -1)
279                 return driver->binary;
280         return buffer_is_binary(buffer, size);
281 }
282
283 #define STREAM_BUFFER_SIZE (1024 * 16)
284
285 static int write_zip_entry(struct archiver_args *args,
286                            const struct object_id *oid,
287                            const char *path, size_t pathlen,
288                            unsigned int mode)
289 {
290         struct zip_local_header header;
291         uintmax_t offset = zip_offset;
292         struct zip_extra_mtime extra;
293         struct zip64_extra extra64;
294         size_t header_extra_size = ZIP_EXTRA_MTIME_SIZE;
295         int need_zip64_extra = 0;
296         unsigned long attr2;
297         unsigned long compressed_size;
298         unsigned long crc;
299         enum zip_method method;
300         unsigned char *out;
301         void *deflated = NULL;
302         void *buffer;
303         struct git_istream *stream = NULL;
304         unsigned long flags = 0;
305         unsigned long size;
306         int is_binary = -1;
307         const char *path_without_prefix = path + args->baselen;
308         unsigned int creator_version = 0;
309         unsigned int version_needed = 10;
310         size_t zip_dir_extra_size = ZIP_EXTRA_MTIME_SIZE;
311         size_t zip64_dir_extra_payload_size = 0;
312
313         crc = crc32(0, NULL, 0);
314
315         if (!has_only_ascii(path)) {
316                 if (is_utf8(path))
317                         flags |= ZIP_UTF8;
318                 else
319                         warning(_("path is not valid UTF-8: %s"), path);
320         }
321
322         if (pathlen > 0xffff) {
323                 return error(_("path too long (%d chars, SHA1: %s): %s"),
324                                 (int)pathlen, oid_to_hex(oid), path);
325         }
326
327         if (S_ISDIR(mode) || S_ISGITLINK(mode)) {
328                 method = ZIP_METHOD_STORE;
329                 attr2 = 16;
330                 out = NULL;
331                 size = 0;
332                 compressed_size = 0;
333                 buffer = NULL;
334         } else if (S_ISREG(mode) || S_ISLNK(mode)) {
335                 enum object_type type = oid_object_info(args->repo, oid,
336                                                         &size);
337
338                 method = ZIP_METHOD_STORE;
339                 attr2 = S_ISLNK(mode) ? ((mode | 0777) << 16) :
340                         (mode & 0111) ? ((mode) << 16) : 0;
341                 if (S_ISLNK(mode) || (mode & 0111))
342                         creator_version = 0x0317;
343                 if (S_ISREG(mode) && args->compression_level != 0 && size > 0)
344                         method = ZIP_METHOD_DEFLATE;
345
346                 if (S_ISREG(mode) && type == OBJ_BLOB && !args->convert &&
347                     size > big_file_threshold) {
348                         stream = open_istream(oid, &type, &size, NULL);
349                         if (!stream)
350                                 return error(_("cannot stream blob %s"),
351                                              oid_to_hex(oid));
352                         flags |= ZIP_STREAM;
353                         out = buffer = NULL;
354                 } else {
355                         buffer = object_file_to_archive(args, path, oid, mode,
356                                                         &type, &size);
357                         if (!buffer)
358                                 return error(_("cannot read %s"),
359                                              oid_to_hex(oid));
360                         crc = crc32(crc, buffer, size);
361                         is_binary = entry_is_binary(args->repo->index,
362                                                     path_without_prefix,
363                                                     buffer, size);
364                         out = buffer;
365                 }
366                 compressed_size = (method == ZIP_METHOD_STORE) ? size : 0;
367         } else {
368                 return error(_("unsupported file mode: 0%o (SHA1: %s)"), mode,
369                                 oid_to_hex(oid));
370         }
371
372         if (creator_version > max_creator_version)
373                 max_creator_version = creator_version;
374
375         if (buffer && method == ZIP_METHOD_DEFLATE) {
376                 out = deflated = zlib_deflate_raw(buffer, size,
377                                                   args->compression_level,
378                                                   &compressed_size);
379                 if (!out || compressed_size >= size) {
380                         out = buffer;
381                         method = ZIP_METHOD_STORE;
382                         compressed_size = size;
383                 }
384         }
385
386         copy_le16(extra.magic, 0x5455);
387         copy_le16(extra.extra_size, ZIP_EXTRA_MTIME_PAYLOAD_SIZE);
388         extra.flags[0] = 1;     /* just mtime */
389         copy_le32(extra.mtime, args->time);
390
391         if (size > 0xffffffff || compressed_size > 0xffffffff)
392                 need_zip64_extra = 1;
393         if (stream && size > 0x7fffffff)
394                 need_zip64_extra = 1;
395
396         if (need_zip64_extra)
397                 version_needed = 45;
398
399         copy_le32(header.magic, 0x04034b50);
400         copy_le16(header.version, version_needed);
401         copy_le16(header.flags, flags);
402         copy_le16(header.compression_method, method);
403         copy_le16(header.mtime, zip_time);
404         copy_le16(header.mdate, zip_date);
405         if (need_zip64_extra) {
406                 set_zip_header_data_desc(&header, 0xffffffff, 0xffffffff, crc);
407                 header_extra_size += ZIP64_EXTRA_SIZE;
408         } else {
409                 set_zip_header_data_desc(&header, size, compressed_size, crc);
410         }
411         copy_le16(header.filename_length, pathlen);
412         copy_le16(header.extra_length, header_extra_size);
413         write_or_die(1, &header, ZIP_LOCAL_HEADER_SIZE);
414         zip_offset += ZIP_LOCAL_HEADER_SIZE;
415         write_or_die(1, path, pathlen);
416         zip_offset += pathlen;
417         write_or_die(1, &extra, ZIP_EXTRA_MTIME_SIZE);
418         zip_offset += ZIP_EXTRA_MTIME_SIZE;
419         if (need_zip64_extra) {
420                 copy_le16(extra64.magic, 0x0001);
421                 copy_le16(extra64.extra_size, ZIP64_EXTRA_PAYLOAD_SIZE);
422                 copy_le64(extra64.size, size);
423                 copy_le64(extra64.compressed_size, compressed_size);
424                 write_or_die(1, &extra64, ZIP64_EXTRA_SIZE);
425                 zip_offset += ZIP64_EXTRA_SIZE;
426         }
427
428         if (stream && method == ZIP_METHOD_STORE) {
429                 unsigned char buf[STREAM_BUFFER_SIZE];
430                 ssize_t readlen;
431
432                 for (;;) {
433                         readlen = read_istream(stream, buf, sizeof(buf));
434                         if (readlen <= 0)
435                                 break;
436                         crc = crc32(crc, buf, readlen);
437                         if (is_binary == -1)
438                                 is_binary = entry_is_binary(args->repo->index,
439                                                             path_without_prefix,
440                                                             buf, readlen);
441                         write_or_die(1, buf, readlen);
442                 }
443                 close_istream(stream);
444                 if (readlen)
445                         return readlen;
446
447                 compressed_size = size;
448                 zip_offset += compressed_size;
449
450                 write_zip_data_desc(size, compressed_size, crc);
451         } else if (stream && method == ZIP_METHOD_DEFLATE) {
452                 unsigned char buf[STREAM_BUFFER_SIZE];
453                 ssize_t readlen;
454                 git_zstream zstream;
455                 int result;
456                 size_t out_len;
457                 unsigned char compressed[STREAM_BUFFER_SIZE * 2];
458
459                 git_deflate_init_raw(&zstream, args->compression_level);
460
461                 compressed_size = 0;
462                 zstream.next_out = compressed;
463                 zstream.avail_out = sizeof(compressed);
464
465                 for (;;) {
466                         readlen = read_istream(stream, buf, sizeof(buf));
467                         if (readlen <= 0)
468                                 break;
469                         crc = crc32(crc, buf, readlen);
470                         if (is_binary == -1)
471                                 is_binary = entry_is_binary(args->repo->index,
472                                                             path_without_prefix,
473                                                             buf, readlen);
474
475                         zstream.next_in = buf;
476                         zstream.avail_in = readlen;
477                         result = git_deflate(&zstream, 0);
478                         if (result != Z_OK)
479                                 die(_("deflate error (%d)"), result);
480                         out_len = zstream.next_out - compressed;
481
482                         if (out_len > 0) {
483                                 write_or_die(1, compressed, out_len);
484                                 compressed_size += out_len;
485                                 zstream.next_out = compressed;
486                                 zstream.avail_out = sizeof(compressed);
487                         }
488
489                 }
490                 close_istream(stream);
491                 if (readlen)
492                         return readlen;
493
494                 zstream.next_in = buf;
495                 zstream.avail_in = 0;
496                 result = git_deflate(&zstream, Z_FINISH);
497                 if (result != Z_STREAM_END)
498                         die("deflate error (%d)", result);
499
500                 git_deflate_end(&zstream);
501                 out_len = zstream.next_out - compressed;
502                 write_or_die(1, compressed, out_len);
503                 compressed_size += out_len;
504                 zip_offset += compressed_size;
505
506                 write_zip_data_desc(size, compressed_size, crc);
507         } else if (compressed_size > 0) {
508                 write_or_die(1, out, compressed_size);
509                 zip_offset += compressed_size;
510         }
511
512         free(deflated);
513         free(buffer);
514
515         if (compressed_size > 0xffffffff || size > 0xffffffff ||
516             offset > 0xffffffff) {
517                 if (compressed_size >= 0xffffffff)
518                         zip64_dir_extra_payload_size += 8;
519                 if (size >= 0xffffffff)
520                         zip64_dir_extra_payload_size += 8;
521                 if (offset >= 0xffffffff)
522                         zip64_dir_extra_payload_size += 8;
523                 zip_dir_extra_size += 2 + 2 + zip64_dir_extra_payload_size;
524         }
525
526         strbuf_add_le(&zip_dir, 4, 0x02014b50); /* magic */
527         strbuf_add_le(&zip_dir, 2, creator_version);
528         strbuf_add_le(&zip_dir, 2, version_needed);
529         strbuf_add_le(&zip_dir, 2, flags);
530         strbuf_add_le(&zip_dir, 2, method);
531         strbuf_add_le(&zip_dir, 2, zip_time);
532         strbuf_add_le(&zip_dir, 2, zip_date);
533         strbuf_add_le(&zip_dir, 4, crc);
534         strbuf_add_le(&zip_dir, 4, clamp32(compressed_size));
535         strbuf_add_le(&zip_dir, 4, clamp32(size));
536         strbuf_add_le(&zip_dir, 2, pathlen);
537         strbuf_add_le(&zip_dir, 2, zip_dir_extra_size);
538         strbuf_add_le(&zip_dir, 2, 0);          /* comment length */
539         strbuf_add_le(&zip_dir, 2, 0);          /* disk */
540         strbuf_add_le(&zip_dir, 2, !is_binary);
541         strbuf_add_le(&zip_dir, 4, attr2);
542         strbuf_add_le(&zip_dir, 4, clamp32(offset));
543         strbuf_add(&zip_dir, path, pathlen);
544         strbuf_add(&zip_dir, &extra, ZIP_EXTRA_MTIME_SIZE);
545         if (zip64_dir_extra_payload_size) {
546                 strbuf_add_le(&zip_dir, 2, 0x0001);     /* magic */
547                 strbuf_add_le(&zip_dir, 2, zip64_dir_extra_payload_size);
548                 if (size >= 0xffffffff)
549                         strbuf_add_le(&zip_dir, 8, size);
550                 if (compressed_size >= 0xffffffff)
551                         strbuf_add_le(&zip_dir, 8, compressed_size);
552                 if (offset >= 0xffffffff)
553                         strbuf_add_le(&zip_dir, 8, offset);
554         }
555         zip_dir_entries++;
556
557         return 0;
558 }
559
560 static void write_zip64_trailer(void)
561 {
562         struct zip64_dir_trailer trailer64;
563         struct zip64_dir_trailer_locator locator64;
564
565         copy_le32(trailer64.magic, 0x06064b50);
566         copy_le64(trailer64.record_size, ZIP64_DIR_TRAILER_RECORD_SIZE);
567         copy_le16(trailer64.creator_version, max_creator_version);
568         copy_le16(trailer64.version, 45);
569         copy_le32(trailer64.disk, 0);
570         copy_le32(trailer64.directory_start_disk, 0);
571         copy_le64(trailer64.entries_on_this_disk, zip_dir_entries);
572         copy_le64(trailer64.entries, zip_dir_entries);
573         copy_le64(trailer64.size, zip_dir.len);
574         copy_le64(trailer64.offset, zip_offset);
575
576         copy_le32(locator64.magic, 0x07064b50);
577         copy_le32(locator64.disk, 0);
578         copy_le64(locator64.offset, zip_offset + zip_dir.len);
579         copy_le32(locator64.number_of_disks, 1);
580
581         write_or_die(1, &trailer64, ZIP64_DIR_TRAILER_SIZE);
582         write_or_die(1, &locator64, ZIP64_DIR_TRAILER_LOCATOR_SIZE);
583 }
584
585 static void write_zip_trailer(const struct object_id *oid)
586 {
587         struct zip_dir_trailer trailer;
588         int clamped = 0;
589
590         copy_le32(trailer.magic, 0x06054b50);
591         copy_le16(trailer.disk, 0);
592         copy_le16(trailer.directory_start_disk, 0);
593         copy_le16_clamp(trailer.entries_on_this_disk, zip_dir_entries,
594                         &clamped);
595         copy_le16_clamp(trailer.entries, zip_dir_entries, &clamped);
596         copy_le32(trailer.size, zip_dir.len);
597         copy_le32_clamp(trailer.offset, zip_offset, &clamped);
598         copy_le16(trailer.comment_length, oid ? the_hash_algo->hexsz : 0);
599
600         write_or_die(1, zip_dir.buf, zip_dir.len);
601         if (clamped)
602                 write_zip64_trailer();
603         write_or_die(1, &trailer, ZIP_DIR_TRAILER_SIZE);
604         if (oid)
605                 write_or_die(1, oid_to_hex(oid), the_hash_algo->hexsz);
606 }
607
608 static void dos_time(timestamp_t *timestamp, int *dos_date, int *dos_time)
609 {
610         time_t time;
611         struct tm tm;
612
613         if (date_overflows(*timestamp))
614                 die(_("timestamp too large for this system: %"PRItime),
615                     *timestamp);
616         time = (time_t)*timestamp;
617         localtime_r(&time, &tm);
618         *timestamp = time;
619
620         *dos_date = tm.tm_mday + (tm.tm_mon + 1) * 32 +
621                     (tm.tm_year + 1900 - 1980) * 512;
622         *dos_time = tm.tm_sec / 2 + tm.tm_min * 32 + tm.tm_hour * 2048;
623 }
624
625 static int archive_zip_config(const char *var, const char *value, void *data)
626 {
627         return userdiff_config(var, value);
628 }
629
630 static int write_zip_archive(const struct archiver *ar,
631                              struct archiver_args *args)
632 {
633         int err;
634
635         git_config(archive_zip_config, NULL);
636
637         dos_time(&args->time, &zip_date, &zip_time);
638
639         strbuf_init(&zip_dir, 0);
640
641         err = write_archive_entries(args, write_zip_entry);
642         if (!err)
643                 write_zip_trailer(args->commit_oid);
644
645         strbuf_release(&zip_dir);
646
647         return err;
648 }
649
650 static struct archiver zip_archiver = {
651         "zip",
652         write_zip_archive,
653         ARCHIVER_WANT_COMPRESSION_LEVELS|ARCHIVER_REMOTE
654 };
655
656 void init_zip_archiver(void)
657 {
658         register_archiver(&zip_archiver);
659 }