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(args->repo, oid, &type, &size,
 349                                               NULL);
 350                         if (!stream)
 351                                 return error(_("cannot stream blob %s"),
 352                                              oid_to_hex(oid));
 353                         flags |= ZIP_STREAM;
 354                         out = buffer = NULL;
 355                 } else {
 356                         buffer = object_file_to_archive(args, path, oid, mode,
 357                                                         &type, &size);
 358                         if (!buffer)
 359                                 return error(_("cannot read %s"),
 360                                              oid_to_hex(oid));
 361                         crc = crc32(crc, buffer, size);
 362                         is_binary = entry_is_binary(args->repo->index,
 363                                                     path_without_prefix,
 364                                                     buffer, size);
 365                         out = buffer;
 366                 }
 367                 compressed_size = (method == ZIP_METHOD_STORE) ? size : 0;
 368         } else {
 369                 return error(_("unsupported file mode: 0%o (SHA1: %s)"), mode,
 370                                 oid_to_hex(oid));
 371         }
 372
 373         if (creator_version > max_creator_version)
 374                 max_creator_version = creator_version;
 375
 376         if (buffer && method == ZIP_METHOD_DEFLATE) {
 377                 out = deflated = zlib_deflate_raw(buffer, size,
 378                                                   args->compression_level,
 379                                                   &compressed_size);
 380                 if (!out || compressed_size >= size) {
 381                         out = buffer;
 382                         method = ZIP_METHOD_STORE;
 383                         compressed_size = size;
 384                 }
 385         }
 386
 387         copy_le16(extra.magic, 0x5455);
 388         copy_le16(extra.extra_size, ZIP_EXTRA_MTIME_PAYLOAD_SIZE);
 389         extra.flags[0] = 1;     /* just mtime */
 390         copy_le32(extra.mtime, args->time);
 391
 392         if (size > 0xffffffff || compressed_size > 0xffffffff)
 393                 need_zip64_extra = 1;
 394         if (stream && size > 0x7fffffff)
 395                 need_zip64_extra = 1;
 396
 397         if (need_zip64_extra)
 398                 version_needed = 45;
 399
 400         copy_le32(header.magic, 0x04034b50);
 401         copy_le16(header.version, version_needed);
 402         copy_le16(header.flags, flags);
 403         copy_le16(header.compression_method, method);
 404         copy_le16(header.mtime, zip_time);
 405         copy_le16(header.mdate, zip_date);
 406         if (need_zip64_extra) {
 407                 set_zip_header_data_desc(&header, 0xffffffff, 0xffffffff, crc);
 408                 header_extra_size += ZIP64_EXTRA_SIZE;
 409         } else {
 410                 set_zip_header_data_desc(&header, size, compressed_size, crc);
 411         }
 412         copy_le16(header.filename_length, pathlen);
 413         copy_le16(header.extra_length, header_extra_size);
 414         write_or_die(1, &header, ZIP_LOCAL_HEADER_SIZE);
 415         zip_offset += ZIP_LOCAL_HEADER_SIZE;
 416         write_or_die(1, path, pathlen);
 417         zip_offset += pathlen;
 418         write_or_die(1, &extra, ZIP_EXTRA_MTIME_SIZE);
 419         zip_offset += ZIP_EXTRA_MTIME_SIZE;
 420         if (need_zip64_extra) {
 421                 copy_le16(extra64.magic, 0x0001);
 422                 copy_le16(extra64.extra_size, ZIP64_EXTRA_PAYLOAD_SIZE);
 423                 copy_le64(extra64.size, size);
 424                 copy_le64(extra64.compressed_size, compressed_size);
 425                 write_or_die(1, &extra64, ZIP64_EXTRA_SIZE);
 426                 zip_offset += ZIP64_EXTRA_SIZE;
 427         }
 428
 429         if (stream && method == ZIP_METHOD_STORE) {
 430                 unsigned char buf[STREAM_BUFFER_SIZE];
 431                 ssize_t readlen;
 432
 433                 for (;;) {
 434                         readlen = read_istream(stream, buf, sizeof(buf));
 435                         if (readlen <= 0)
 436                                 break;
 437                         crc = crc32(crc, buf, readlen);
 438                         if (is_binary == -1)
 439                                 is_binary = entry_is_binary(args->repo->index,
 440                                                             path_without_prefix,
 441                                                             buf, readlen);
 442                         write_or_die(1, buf, readlen);
 443                 }
 444                 close_istream(stream);
 445                 if (readlen)
 446                         return readlen;
 447
 448                 compressed_size = size;
 449                 zip_offset += compressed_size;
 450
 451                 write_zip_data_desc(size, compressed_size, crc);
 452         } else if (stream && method == ZIP_METHOD_DEFLATE) {
 453                 unsigned char buf[STREAM_BUFFER_SIZE];
 454                 ssize_t readlen;
 455                 git_zstream zstream;
 456                 int result;
 457                 size_t out_len;
 458                 unsigned char compressed[STREAM_BUFFER_SIZE * 2];
 459
 460                 git_deflate_init_raw(&zstream, args->compression_level);
 461
 462                 compressed_size = 0;
 463                 zstream.next_out = compressed;
 464                 zstream.avail_out = sizeof(compressed);
 465
 466                 for (;;) {
 467                         readlen = read_istream(stream, buf, sizeof(buf));
 468                         if (readlen <= 0)
 469                                 break;
 470                         crc = crc32(crc, buf, readlen);
 471                         if (is_binary == -1)
 472                                 is_binary = entry_is_binary(args->repo->index,
 473                                                             path_without_prefix,
 474                                                             buf, readlen);
 475
 476                         zstream.next_in = buf;
 477                         zstream.avail_in = readlen;
 478                         result = git_deflate(&zstream, 0);
 479                         if (result != Z_OK)
 480                                 die(_("deflate error (%d)"), result);
 481                         out_len = zstream.next_out - compressed;
 482
 483                         if (out_len > 0) {
 484                                 write_or_die(1, compressed, out_len);
 485                                 compressed_size += out_len;
 486                                 zstream.next_out = compressed;
 487                                 zstream.avail_out = sizeof(compressed);
 488                         }
 489
 490                 }
 491                 close_istream(stream);
 492                 if (readlen)
 493                         return readlen;
 494
 495                 zstream.next_in = buf;
 496                 zstream.avail_in = 0;
 497                 result = git_deflate(&zstream, Z_FINISH);
 498                 if (result != Z_STREAM_END)
 499                         die("deflate error (%d)", result);
 500
 501                 git_deflate_end(&zstream);
 502                 out_len = zstream.next_out - compressed;
 503                 write_or_die(1, compressed, out_len);
 504                 compressed_size += out_len;
 505                 zip_offset += compressed_size;
 506
 507                 write_zip_data_desc(size, compressed_size, crc);
 508         } else if (compressed_size > 0) {
 509                 write_or_die(1, out, compressed_size);
 510                 zip_offset += compressed_size;
 511         }
 512
 513         free(deflated);
 514         free(buffer);
 515
 516         if (compressed_size > 0xffffffff || size > 0xffffffff ||
 517             offset > 0xffffffff) {
 518                 if (compressed_size >= 0xffffffff)
 519                         zip64_dir_extra_payload_size += 8;
 520                 if (size >= 0xffffffff)
 521                         zip64_dir_extra_payload_size += 8;
 522                 if (offset >= 0xffffffff)
 523                         zip64_dir_extra_payload_size += 8;
 524                 zip_dir_extra_size += 2 + 2 + zip64_dir_extra_payload_size;
 525         }
 526
 527         strbuf_add_le(&zip_dir, 4, 0x02014b50); /* magic */
 528         strbuf_add_le(&zip_dir, 2, creator_version);
 529         strbuf_add_le(&zip_dir, 2, version_needed);
 530         strbuf_add_le(&zip_dir, 2, flags);
 531         strbuf_add_le(&zip_dir, 2, method);
 532         strbuf_add_le(&zip_dir, 2, zip_time);
 533         strbuf_add_le(&zip_dir, 2, zip_date);
 534         strbuf_add_le(&zip_dir, 4, crc);
 535         strbuf_add_le(&zip_dir, 4, clamp32(compressed_size));
 536         strbuf_add_le(&zip_dir, 4, clamp32(size));
 537         strbuf_add_le(&zip_dir, 2, pathlen);
 538         strbuf_add_le(&zip_dir, 2, zip_dir_extra_size);
 539         strbuf_add_le(&zip_dir, 2, 0);          /* comment length */
 540         strbuf_add_le(&zip_dir, 2, 0);          /* disk */
 541         strbuf_add_le(&zip_dir, 2, !is_binary);
 542         strbuf_add_le(&zip_dir, 4, attr2);
 543         strbuf_add_le(&zip_dir, 4, clamp32(offset));
 544         strbuf_add(&zip_dir, path, pathlen);
 545         strbuf_add(&zip_dir, &extra, ZIP_EXTRA_MTIME_SIZE);
 546         if (zip64_dir_extra_payload_size) {
 547                 strbuf_add_le(&zip_dir, 2, 0x0001);     /* magic */
 548                 strbuf_add_le(&zip_dir, 2, zip64_dir_extra_payload_size);
 549                 if (size >= 0xffffffff)
 550                         strbuf_add_le(&zip_dir, 8, size);
 551                 if (compressed_size >= 0xffffffff)
 552                         strbuf_add_le(&zip_dir, 8, compressed_size);
 553                 if (offset >= 0xffffffff)
 554                         strbuf_add_le(&zip_dir, 8, offset);
 555         }
 556         zip_dir_entries++;
 557
 558         return 0;
 559 }
 560
 561 static void write_zip64_trailer(void)
 562 {
 563         struct zip64_dir_trailer trailer64;
 564         struct zip64_dir_trailer_locator locator64;
 565
 566         copy_le32(trailer64.magic, 0x06064b50);
 567         copy_le64(trailer64.record_size, ZIP64_DIR_TRAILER_RECORD_SIZE);
 568         copy_le16(trailer64.creator_version, max_creator_version);
 569         copy_le16(trailer64.version, 45);
 570         copy_le32(trailer64.disk, 0);
 571         copy_le32(trailer64.directory_start_disk, 0);
 572         copy_le64(trailer64.entries_on_this_disk, zip_dir_entries);
 573         copy_le64(trailer64.entries, zip_dir_entries);
 574         copy_le64(trailer64.size, zip_dir.len);
 575         copy_le64(trailer64.offset, zip_offset);
 576
 577         copy_le32(locator64.magic, 0x07064b50);
 578         copy_le32(locator64.disk, 0);
 579         copy_le64(locator64.offset, zip_offset + zip_dir.len);
 580         copy_le32(locator64.number_of_disks, 1);
 581
 582         write_or_die(1, &trailer64, ZIP64_DIR_TRAILER_SIZE);
 583         write_or_die(1, &locator64, ZIP64_DIR_TRAILER_LOCATOR_SIZE);
 584 }
 585
 586 static void write_zip_trailer(const struct object_id *oid)
 587 {
 588         struct zip_dir_trailer trailer;
 589         int clamped = 0;
 590
 591         copy_le32(trailer.magic, 0x06054b50);
 592         copy_le16(trailer.disk, 0);
 593         copy_le16(trailer.directory_start_disk, 0);
 594         copy_le16_clamp(trailer.entries_on_this_disk, zip_dir_entries,
 595                         &clamped);
 596         copy_le16_clamp(trailer.entries, zip_dir_entries, &clamped);
 597         copy_le32(trailer.size, zip_dir.len);
 598         copy_le32_clamp(trailer.offset, zip_offset, &clamped);
 599         copy_le16(trailer.comment_length, oid ? the_hash_algo->hexsz : 0);
 600
 601         write_or_die(1, zip_dir.buf, zip_dir.len);
 602         if (clamped)
 603                 write_zip64_trailer();
 604         write_or_die(1, &trailer, ZIP_DIR_TRAILER_SIZE);
 605         if (oid)
 606                 write_or_die(1, oid_to_hex(oid), the_hash_algo->hexsz);
 607 }
 608
 609 static void dos_time(timestamp_t *timestamp, int *dos_date, int *dos_time)
 610 {
 611         time_t time;
 612         struct tm tm;
 613
 614         if (date_overflows(*timestamp))
 615                 die(_("timestamp too large for this system: %"PRItime),
 616                     *timestamp);
 617         time = (time_t)*timestamp;
 618         localtime_r(&time, &tm);
 619         *timestamp = time;
 620
 621         *dos_date = tm.tm_mday + (tm.tm_mon + 1) * 32 +
 622                     (tm.tm_year + 1900 - 1980) * 512;
 623         *dos_time = tm.tm_sec / 2 + tm.tm_min * 32 + tm.tm_hour * 2048;
 624 }
 625
 626 static int archive_zip_config(const char *var, const char *value, void *data)
 627 {
 628         return userdiff_config(var, value);
 629 }
 630
 631 static int write_zip_archive(const struct archiver *ar,
 632                              struct archiver_args *args)
 633 {
 634         int err;
 635
 636         git_config(archive_zip_config, NULL);
 637
 638         dos_time(&args->time, &zip_date, &zip_time);
 639
 640         strbuf_init(&zip_dir, 0);
 641
 642         err = write_archive_entries(args, write_zip_entry);
 643         if (!err)
 644                 write_zip_trailer(args->commit_oid);
 645
 646         strbuf_release(&zip_dir);
 647
 648         return err;
 649 }
 650
 651 static struct archiver zip_archiver = {
 652         "zip",
 653         write_zip_archive,
 654         ARCHIVER_WANT_COMPRESSION_LEVELS|ARCHIVER_REMOTE
 655 };
 656
 657 void init_zip_archiver(void)
 658 {
 659         register_archiver(&zip_archiver);
 660 }