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 "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 }