git.oblomov.eu Git - git/blob - 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 "userdiff.h"
  10 #include "xdiff-interface.h"
  11
  12 static int zip_date;
  13 static int zip_time;
  14
  15 /* We only care about the "buf" part here. */
  16 static struct strbuf zip_dir;
  17
  18 static uintmax_t zip_offset;
  19 static uint64_t zip_dir_entries;
  20
  21 static unsigned int max_creator_version;
  22
  23 #define ZIP_STREAM      (1 <<  3)
  24 #define ZIP_UTF8        (1 << 11)
  25
  26 struct zip_local_header {
  27         unsigned char magic[4];
  28         unsigned char version[2];
  29         unsigned char flags[2];
  30         unsigned char compression_method[2];
  31         unsigned char mtime[2];
  32         unsigned char mdate[2];
  33         unsigned char crc32[4];
  34         unsigned char compressed_size[4];
  35         unsigned char size[4];
  36         unsigned char filename_length[2];
  37         unsigned char extra_length[2];
  38         unsigned char _end[1];
  39 };
  40
  41 struct zip_data_desc {
  42         unsigned char magic[4];
  43         unsigned char crc32[4];
  44         unsigned char compressed_size[4];
  45         unsigned char size[4];
  46         unsigned char _end[1];
  47 };
  48
  49 struct zip64_data_desc {
  50         unsigned char magic[4];
  51         unsigned char crc32[4];
  52         unsigned char compressed_size[8];
  53         unsigned char size[8];
  54         unsigned char _end[1];
  55 };
  56
  57 struct zip_dir_trailer {
  58         unsigned char magic[4];
  59         unsigned char disk[2];
  60         unsigned char directory_start_disk[2];
  61         unsigned char entries_on_this_disk[2];
  62         unsigned char entries[2];
  63         unsigned char size[4];
  64         unsigned char offset[4];
  65         unsigned char comment_length[2];
  66         unsigned char _end[1];
  67 };
  68
  69 struct zip_extra_mtime {
  70         unsigned char magic[2];
  71         unsigned char extra_size[2];
  72         unsigned char flags[1];
  73         unsigned char mtime[4];
  74         unsigned char _end[1];
  75 };
  76
  77 struct zip64_extra {
  78         unsigned char magic[2];
  79         unsigned char extra_size[2];
  80         unsigned char size[8];
  81         unsigned char compressed_size[8];
  82         unsigned char _end[1];
  83 };
  84
  85 struct zip64_dir_trailer {
  86         unsigned char magic[4];
  87         unsigned char record_size[8];
  88         unsigned char creator_version[2];
  89         unsigned char version[2];
  90         unsigned char disk[4];
  91         unsigned char directory_start_disk[4];
  92         unsigned char entries_on_this_disk[8];
  93         unsigned char entries[8];
  94         unsigned char size[8];
  95         unsigned char offset[8];
  96         unsigned char _end[1];
  97 };
  98
  99 struct zip64_dir_trailer_locator {
 100         unsigned char magic[4];
 101         unsigned char disk[4];
 102         unsigned char offset[8];
 103         unsigned char number_of_disks[4];
 104         unsigned char _end[1];
 105 };
 106
 107 /*
 108  * On ARM, padding is added at the end of the struct, so a simple
 109  * sizeof(struct ...) reports two bytes more than the payload size
 110  * we're interested in.
 111  */
 112 #define ZIP_LOCAL_HEADER_SIZE   offsetof(struct zip_local_header, _end)
 113 #define ZIP_DATA_DESC_SIZE      offsetof(struct zip_data_desc, _end)
 114 #define ZIP64_DATA_DESC_SIZE    offsetof(struct zip64_data_desc, _end)
 115 #define ZIP_DIR_HEADER_SIZE     offsetof(struct zip_dir_header, _end)
 116 #define ZIP_DIR_TRAILER_SIZE    offsetof(struct zip_dir_trailer, _end)
 117 #define ZIP_EXTRA_MTIME_SIZE    offsetof(struct zip_extra_mtime, _end)
 118 #define ZIP_EXTRA_MTIME_PAYLOAD_SIZE \
 119         (ZIP_EXTRA_MTIME_SIZE - offsetof(struct zip_extra_mtime, flags))
 120 #define ZIP64_EXTRA_SIZE        offsetof(struct zip64_extra, _end)
 121 #define ZIP64_EXTRA_PAYLOAD_SIZE \
 122         (ZIP64_EXTRA_SIZE - offsetof(struct zip64_extra, size))
 123 #define ZIP64_DIR_TRAILER_SIZE  offsetof(struct zip64_dir_trailer, _end)
 124 #define ZIP64_DIR_TRAILER_RECORD_SIZE \
 125         (ZIP64_DIR_TRAILER_SIZE - \
 126          offsetof(struct zip64_dir_trailer, creator_version))
 127 #define ZIP64_DIR_TRAILER_LOCATOR_SIZE \
 128         offsetof(struct zip64_dir_trailer_locator, _end)
 129
 130 static void copy_le16(unsigned char *dest, unsigned int n)
 131 {
 132         dest[0] = 0xff & n;
 133         dest[1] = 0xff & (n >> 010);
 134 }
 135
 136 static void copy_le32(unsigned char *dest, unsigned int n)
 137 {
 138         dest[0] = 0xff & n;
 139         dest[1] = 0xff & (n >> 010);
 140         dest[2] = 0xff & (n >> 020);
 141         dest[3] = 0xff & (n >> 030);
 142 }
 143
 144 static void copy_le64(unsigned char *dest, uint64_t n)
 145 {
 146         dest[0] = 0xff & n;
 147         dest[1] = 0xff & (n >> 010);
 148         dest[2] = 0xff & (n >> 020);
 149         dest[3] = 0xff & (n >> 030);
 150         dest[4] = 0xff & (n >> 040);
 151         dest[5] = 0xff & (n >> 050);
 152         dest[6] = 0xff & (n >> 060);
 153         dest[7] = 0xff & (n >> 070);
 154 }
 155
 156 static uint64_t clamp_max(uint64_t n, uint64_t max, int *clamped)
 157 {
 158         if (n <= max)
 159                 return n;
 160         *clamped = 1;
 161         return max;
 162 }
 163
 164 static void copy_le16_clamp(unsigned char *dest, uint64_t n, int *clamped)
 165 {
 166         copy_le16(dest, clamp_max(n, 0xffff, clamped));
 167 }
 168
 169 static void copy_le32_clamp(unsigned char *dest, uint64_t n, int *clamped)
 170 {
 171         copy_le32(dest, clamp_max(n, 0xffffffff, clamped));
 172 }
 173
 174 static int strbuf_add_le(struct strbuf *sb, size_t size, uintmax_t n)
 175 {
 176         while (size-- > 0) {
 177                 strbuf_addch(sb, n & 0xff);
 178                 n >>= 8;
 179         }
 180         return -!!n;
 181 }
 182
 183 static uint32_t clamp32(uintmax_t n)
 184 {
 185         const uintmax_t max = 0xffffffff;
 186         return (n < max) ? n : max;
 187 }
 188
 189 static void *zlib_deflate_raw(void *data, unsigned long size,
 190                               int compression_level,
 191                               unsigned long *compressed_size)
 192 {
 193         git_zstream stream;
 194         unsigned long maxsize;
 195         void *buffer;
 196         int result;
 197
 198         git_deflate_init_raw(&stream, compression_level);
 199         maxsize = git_deflate_bound(&stream, size);
 200         buffer = xmalloc(maxsize);
 201
 202         stream.next_in = data;
 203         stream.avail_in = size;
 204         stream.next_out = buffer;
 205         stream.avail_out = maxsize;
 206
 207         do {
 208                 result = git_deflate(&stream, Z_FINISH);
 209         } while (result == Z_OK);
 210
 211         if (result != Z_STREAM_END) {
 212                 free(buffer);
 213                 return NULL;
 214         }
 215
 216         git_deflate_end(&stream);
 217         *compressed_size = stream.total_out;
 218
 219         return buffer;
 220 }
 221
 222 static void write_zip_data_desc(unsigned long size,
 223                                 unsigned long compressed_size,
 224                                 unsigned long crc)
 225 {
 226         if (size >= 0xffffffff || compressed_size >= 0xffffffff) {
 227                 struct zip64_data_desc trailer;
 228                 copy_le32(trailer.magic, 0x08074b50);
 229                 copy_le32(trailer.crc32, crc);
 230                 copy_le64(trailer.compressed_size, compressed_size);
 231                 copy_le64(trailer.size, size);
 232                 write_or_die(1, &trailer, ZIP64_DATA_DESC_SIZE);
 233                 zip_offset += ZIP64_DATA_DESC_SIZE;
 234         } else {
 235                 struct zip_data_desc trailer;
 236                 copy_le32(trailer.magic, 0x08074b50);
 237                 copy_le32(trailer.crc32, crc);
 238                 copy_le32(trailer.compressed_size, compressed_size);
 239                 copy_le32(trailer.size, size);
 240                 write_or_die(1, &trailer, ZIP_DATA_DESC_SIZE);
 241                 zip_offset += ZIP_DATA_DESC_SIZE;
 242         }
 243 }
 244
 245 static void set_zip_header_data_desc(struct zip_local_header *header,
 246                                      unsigned long size,
 247                                      unsigned long compressed_size,
 248                                      unsigned long crc)
 249 {
 250         copy_le32(header->crc32, crc);
 251         copy_le32(header->compressed_size, compressed_size);
 252         copy_le32(header->size, size);
 253 }
 254
 255 static int has_only_ascii(const char *s)
 256 {
 257         for (;;) {
 258                 int c = *s++;
 259                 if (c == '\0')
 260                         return 1;
 261                 if (!isascii(c))
 262                         return 0;
 263         }
 264 }
 265
 266 static int entry_is_binary(const char *path, const void *buffer, size_t size)
 267 {
 268         struct userdiff_driver *driver = userdiff_find_by_path(path);
 269         if (!driver)
 270                 driver = userdiff_find_by_name("default");
 271         if (driver->binary != -1)
 272                 return driver->binary;
 273         return buffer_is_binary(buffer, size);
 274 }
 275
 276 #define STREAM_BUFFER_SIZE (1024 * 16)
 277
 278 static int write_zip_entry(struct archiver_args *args,
 279                            const struct object_id *oid,
 280                            const char *path, size_t pathlen,
 281                            unsigned int mode)
 282 {
 283         struct zip_local_header header;
 284         uintmax_t offset = zip_offset;
 285         struct zip_extra_mtime extra;
 286         struct zip64_extra extra64;
 287         size_t header_extra_size = ZIP_EXTRA_MTIME_SIZE;
 288         int need_zip64_extra = 0;
 289         unsigned long attr2;
 290         unsigned long compressed_size;
 291         unsigned long crc;
 292         int method;
 293         unsigned char *out;
 294         void *deflated = NULL;
 295         void *buffer;
 296         struct git_istream *stream = NULL;
 297         unsigned long flags = 0;
 298         unsigned long size;
 299         int is_binary = -1;
 300         const char *path_without_prefix = path + args->baselen;
 301         unsigned int creator_version = 0;
 302         unsigned int version_needed = 10;
 303         size_t zip_dir_extra_size = ZIP_EXTRA_MTIME_SIZE;
 304         size_t zip64_dir_extra_payload_size = 0;
 305
 306         crc = crc32(0, NULL, 0);
 307
 308         if (!has_only_ascii(path)) {
 309                 if (is_utf8(path))
 310                         flags |= ZIP_UTF8;
 311                 else
 312                         warning("Path is not valid UTF-8: %s", path);
 313         }
 314
 315         if (pathlen > 0xffff) {
 316                 return error("path too long (%d chars, SHA1: %s): %s",
 317                                 (int)pathlen, oid_to_hex(oid), path);
 318         }
 319
 320         if (S_ISDIR(mode) || S_ISGITLINK(mode)) {
 321                 method = 0;
 322                 attr2 = 16;
 323                 out = NULL;
 324                 size = 0;
 325                 compressed_size = 0;
 326                 buffer = NULL;
 327         } else if (S_ISREG(mode) || S_ISLNK(mode)) {
 328                 enum object_type type = oid_object_info(the_repository, oid,
 329                                                         &size);
 330
 331                 method = 0;
 332                 attr2 = S_ISLNK(mode) ? ((mode | 0777) << 16) :
 333                         (mode & 0111) ? ((mode) << 16) : 0;
 334                 if (S_ISLNK(mode) || (mode & 0111))
 335                         creator_version = 0x0317;
 336                 if (S_ISREG(mode) && args->compression_level != 0 && size > 0)
 337                         method = 8;
 338
 339                 if (S_ISREG(mode) && type == OBJ_BLOB && !args->convert &&
 340                     size > big_file_threshold) {
 341                         stream = open_istream(oid, &type, &size, NULL);
 342                         if (!stream)
 343                                 return error("cannot stream blob %s",
 344                                              oid_to_hex(oid));
 345                         flags |= ZIP_STREAM;
 346                         out = buffer = NULL;
 347                 } else {
 348                         buffer = object_file_to_archive(args, path, oid, mode,
 349                                                         &type, &size);
 350                         if (!buffer)
 351                                 return error("cannot read %s",
 352                                              oid_to_hex(oid));
 353                         crc = crc32(crc, buffer, size);
 354                         is_binary = entry_is_binary(path_without_prefix,
 355                                                     buffer, size);
 356                         out = buffer;
 357                 }
 358                 compressed_size = (method == 0) ? size : 0;
 359         } else {
 360                 return error("unsupported file mode: 0%o (SHA1: %s)", mode,
 361                                 oid_to_hex(oid));
 362         }
 363
 364         if (creator_version > max_creator_version)
 365                 max_creator_version = creator_version;
 366
 367         if (buffer && method == 8) {
 368                 out = deflated = zlib_deflate_raw(buffer, size,
 369                                                   args->compression_level,
 370                                                   &compressed_size);
 371                 if (!out || compressed_size >= size) {
 372                         out = buffer;
 373                         method = 0;
 374                         compressed_size = size;
 375                 }
 376         }
 377
 378         copy_le16(extra.magic, 0x5455);
 379         copy_le16(extra.extra_size, ZIP_EXTRA_MTIME_PAYLOAD_SIZE);
 380         extra.flags[0] = 1;     /* just mtime */
 381         copy_le32(extra.mtime, args->time);
 382
 383         if (size > 0xffffffff || compressed_size > 0xffffffff)
 384                 need_zip64_extra = 1;
 385         if (stream && size > 0x7fffffff)
 386                 need_zip64_extra = 1;
 387
 388         if (need_zip64_extra)
 389                 version_needed = 45;
 390
 391         copy_le32(header.magic, 0x04034b50);
 392         copy_le16(header.version, version_needed);
 393         copy_le16(header.flags, flags);
 394         copy_le16(header.compression_method, method);
 395         copy_le16(header.mtime, zip_time);
 396         copy_le16(header.mdate, zip_date);
 397         if (need_zip64_extra) {
 398                 set_zip_header_data_desc(&header, 0xffffffff, 0xffffffff, crc);
 399                 header_extra_size += ZIP64_EXTRA_SIZE;
 400         } else {
 401                 set_zip_header_data_desc(&header, size, compressed_size, crc);
 402         }
 403         copy_le16(header.filename_length, pathlen);
 404         copy_le16(header.extra_length, header_extra_size);
 405         write_or_die(1, &header, ZIP_LOCAL_HEADER_SIZE);
 406         zip_offset += ZIP_LOCAL_HEADER_SIZE;
 407         write_or_die(1, path, pathlen);
 408         zip_offset += pathlen;
 409         write_or_die(1, &extra, ZIP_EXTRA_MTIME_SIZE);
 410         zip_offset += ZIP_EXTRA_MTIME_SIZE;
 411         if (need_zip64_extra) {
 412                 copy_le16(extra64.magic, 0x0001);
 413                 copy_le16(extra64.extra_size, ZIP64_EXTRA_PAYLOAD_SIZE);
 414                 copy_le64(extra64.size, size);
 415                 copy_le64(extra64.compressed_size, compressed_size);
 416                 write_or_die(1, &extra64, ZIP64_EXTRA_SIZE);
 417                 zip_offset += ZIP64_EXTRA_SIZE;
 418         }
 419
 420         if (stream && method == 0) {
 421                 unsigned char buf[STREAM_BUFFER_SIZE];
 422                 ssize_t readlen;
 423
 424                 for (;;) {
 425                         readlen = read_istream(stream, buf, sizeof(buf));
 426                         if (readlen <= 0)
 427                                 break;
 428                         crc = crc32(crc, buf, readlen);
 429                         if (is_binary == -1)
 430                                 is_binary = entry_is_binary(path_without_prefix,
 431                                                             buf, readlen);
 432                         write_or_die(1, buf, readlen);
 433                 }
 434                 close_istream(stream);
 435                 if (readlen)
 436                         return readlen;
 437
 438                 compressed_size = size;
 439                 zip_offset += compressed_size;
 440
 441                 write_zip_data_desc(size, compressed_size, crc);
 442         } else if (stream && method == 8) {
 443                 unsigned char buf[STREAM_BUFFER_SIZE];
 444                 ssize_t readlen;
 445                 git_zstream zstream;
 446                 int result;
 447                 size_t out_len;
 448                 unsigned char compressed[STREAM_BUFFER_SIZE * 2];
 449
 450                 git_deflate_init_raw(&zstream, args->compression_level);
 451
 452                 compressed_size = 0;
 453                 zstream.next_out = compressed;
 454                 zstream.avail_out = sizeof(compressed);
 455
 456                 for (;;) {
 457                         readlen = read_istream(stream, buf, sizeof(buf));
 458                         if (readlen <= 0)
 459                                 break;
 460                         crc = crc32(crc, buf, readlen);
 461                         if (is_binary == -1)
 462                                 is_binary = entry_is_binary(path_without_prefix,
 463                                                             buf, readlen);
 464
 465                         zstream.next_in = buf;
 466                         zstream.avail_in = readlen;
 467                         result = git_deflate(&zstream, 0);
 468                         if (result != Z_OK)
 469                                 die("deflate error (%d)", result);
 470                         out_len = zstream.next_out - compressed;
 471
 472                         if (out_len > 0) {
 473                                 write_or_die(1, compressed, out_len);
 474                                 compressed_size += out_len;
 475                                 zstream.next_out = compressed;
 476                                 zstream.avail_out = sizeof(compressed);
 477                         }
 478
 479                 }
 480                 close_istream(stream);
 481                 if (readlen)
 482                         return readlen;
 483
 484                 zstream.next_in = buf;
 485                 zstream.avail_in = 0;
 486                 result = git_deflate(&zstream, Z_FINISH);
 487                 if (result != Z_STREAM_END)
 488                         die("deflate error (%d)", result);
 489
 490                 git_deflate_end(&zstream);
 491                 out_len = zstream.next_out - compressed;
 492                 write_or_die(1, compressed, out_len);
 493                 compressed_size += out_len;
 494                 zip_offset += compressed_size;
 495
 496                 write_zip_data_desc(size, compressed_size, crc);
 497         } else if (compressed_size > 0) {
 498                 write_or_die(1, out, compressed_size);
 499                 zip_offset += compressed_size;
 500         }
 501
 502         free(deflated);
 503         free(buffer);
 504
 505         if (compressed_size > 0xffffffff || size > 0xffffffff ||
 506             offset > 0xffffffff) {
 507                 if (compressed_size >= 0xffffffff)
 508                         zip64_dir_extra_payload_size += 8;
 509                 if (size >= 0xffffffff)
 510                         zip64_dir_extra_payload_size += 8;
 511                 if (offset >= 0xffffffff)
 512                         zip64_dir_extra_payload_size += 8;
 513                 zip_dir_extra_size += 2 + 2 + zip64_dir_extra_payload_size;
 514         }
 515
 516         strbuf_add_le(&zip_dir, 4, 0x02014b50); /* magic */
 517         strbuf_add_le(&zip_dir, 2, creator_version);
 518         strbuf_add_le(&zip_dir, 2, version_needed);
 519         strbuf_add_le(&zip_dir, 2, flags);
 520         strbuf_add_le(&zip_dir, 2, method);
 521         strbuf_add_le(&zip_dir, 2, zip_time);
 522         strbuf_add_le(&zip_dir, 2, zip_date);
 523         strbuf_add_le(&zip_dir, 4, crc);
 524         strbuf_add_le(&zip_dir, 4, clamp32(compressed_size));
 525         strbuf_add_le(&zip_dir, 4, clamp32(size));
 526         strbuf_add_le(&zip_dir, 2, pathlen);
 527         strbuf_add_le(&zip_dir, 2, zip_dir_extra_size);
 528         strbuf_add_le(&zip_dir, 2, 0);          /* comment length */
 529         strbuf_add_le(&zip_dir, 2, 0);          /* disk */
 530         strbuf_add_le(&zip_dir, 2, !is_binary);
 531         strbuf_add_le(&zip_dir, 4, attr2);
 532         strbuf_add_le(&zip_dir, 4, clamp32(offset));
 533         strbuf_add(&zip_dir, path, pathlen);
 534         strbuf_add(&zip_dir, &extra, ZIP_EXTRA_MTIME_SIZE);
 535         if (zip64_dir_extra_payload_size) {
 536                 strbuf_add_le(&zip_dir, 2, 0x0001);     /* magic */
 537                 strbuf_add_le(&zip_dir, 2, zip64_dir_extra_payload_size);
 538                 if (size >= 0xffffffff)
 539                         strbuf_add_le(&zip_dir, 8, size);
 540                 if (compressed_size >= 0xffffffff)
 541                         strbuf_add_le(&zip_dir, 8, compressed_size);
 542                 if (offset >= 0xffffffff)
 543                         strbuf_add_le(&zip_dir, 8, offset);
 544         }
 545         zip_dir_entries++;
 546
 547         return 0;
 548 }
 549
 550 static void write_zip64_trailer(void)
 551 {
 552         struct zip64_dir_trailer trailer64;
 553         struct zip64_dir_trailer_locator locator64;
 554
 555         copy_le32(trailer64.magic, 0x06064b50);
 556         copy_le64(trailer64.record_size, ZIP64_DIR_TRAILER_RECORD_SIZE);
 557         copy_le16(trailer64.creator_version, max_creator_version);
 558         copy_le16(trailer64.version, 45);
 559         copy_le32(trailer64.disk, 0);
 560         copy_le32(trailer64.directory_start_disk, 0);
 561         copy_le64(trailer64.entries_on_this_disk, zip_dir_entries);
 562         copy_le64(trailer64.entries, zip_dir_entries);
 563         copy_le64(trailer64.size, zip_dir.len);
 564         copy_le64(trailer64.offset, zip_offset);
 565
 566         copy_le32(locator64.magic, 0x07064b50);
 567         copy_le32(locator64.disk, 0);
 568         copy_le64(locator64.offset, zip_offset + zip_dir.len);
 569         copy_le32(locator64.number_of_disks, 1);
 570
 571         write_or_die(1, &trailer64, ZIP64_DIR_TRAILER_SIZE);
 572         write_or_die(1, &locator64, ZIP64_DIR_TRAILER_LOCATOR_SIZE);
 573 }
 574
 575 static void write_zip_trailer(const unsigned char *sha1)
 576 {
 577         struct zip_dir_trailer trailer;
 578         int clamped = 0;
 579
 580         copy_le32(trailer.magic, 0x06054b50);
 581         copy_le16(trailer.disk, 0);
 582         copy_le16(trailer.directory_start_disk, 0);
 583         copy_le16_clamp(trailer.entries_on_this_disk, zip_dir_entries,
 584                         &clamped);
 585         copy_le16_clamp(trailer.entries, zip_dir_entries, &clamped);
 586         copy_le32(trailer.size, zip_dir.len);
 587         copy_le32_clamp(trailer.offset, zip_offset, &clamped);
 588         copy_le16(trailer.comment_length, sha1 ? GIT_SHA1_HEXSZ : 0);
 589
 590         write_or_die(1, zip_dir.buf, zip_dir.len);
 591         if (clamped)
 592                 write_zip64_trailer();
 593         write_or_die(1, &trailer, ZIP_DIR_TRAILER_SIZE);
 594         if (sha1)
 595                 write_or_die(1, sha1_to_hex(sha1), GIT_SHA1_HEXSZ);
 596 }
 597
 598 static void dos_time(timestamp_t *timestamp, int *dos_date, int *dos_time)
 599 {
 600         time_t time;
 601         struct tm *t;
 602
 603         if (date_overflows(*timestamp))
 604                 die("timestamp too large for this system: %"PRItime,
 605                     *timestamp);
 606         time = (time_t)*timestamp;
 607         t = localtime(&time);
 608         *timestamp = time;
 609
 610         *dos_date = t->tm_mday + (t->tm_mon + 1) * 32 +
 611                     (t->tm_year + 1900 - 1980) * 512;
 612         *dos_time = t->tm_sec / 2 + t->tm_min * 32 + t->tm_hour * 2048;
 613 }
 614
 615 static int archive_zip_config(const char *var, const char *value, void *data)
 616 {
 617         return userdiff_config(var, value);
 618 }
 619
 620 static int write_zip_archive(const struct archiver *ar,
 621                              struct archiver_args *args)
 622 {
 623         int err;
 624
 625         git_config(archive_zip_config, NULL);
 626
 627         dos_time(&args->time, &zip_date, &zip_time);
 628
 629         strbuf_init(&zip_dir, 0);
 630
 631         err = write_archive_entries(args, write_zip_entry);
 632         if (!err)
 633                 write_zip_trailer(args->commit_sha1);
 634
 635         strbuf_release(&zip_dir);
 636
 637         return err;
 638 }
 639
 640 static struct archiver zip_archiver = {
 641         "zip",
 642         write_zip_archive,
 643         ARCHIVER_WANT_COMPRESSION_LEVELS|ARCHIVER_REMOTE
 644 };
 645
 646 void init_zip_archiver(void)
 647 {
 648         register_archiver(&zip_archiver);
 649 }