archive-zip.c

   1 /*
   2  * Copyright (c) 2006 Rene Scharfe
   3  */
   4 #include "cache.h"
   5 #include "archive.h"
   6
   7 static int zip_date;
   8 static int zip_time;
   9
  10 static unsigned char *zip_dir;
  11 static unsigned int zip_dir_size;
  12
  13 static unsigned int zip_offset;
  14 static unsigned int zip_dir_offset;
  15 static unsigned int zip_dir_entries;
  16
  17 #define ZIP_DIRECTORY_MIN_SIZE  (1024 * 1024)
  18
  19 struct zip_local_header {
  20         unsigned char magic[4];
  21         unsigned char version[2];
  22         unsigned char flags[2];
  23         unsigned char compression_method[2];
  24         unsigned char mtime[2];
  25         unsigned char mdate[2];
  26         unsigned char crc32[4];
  27         unsigned char compressed_size[4];
  28         unsigned char size[4];
  29         unsigned char filename_length[2];
  30         unsigned char extra_length[2];
  31         unsigned char _end[1];
  32 };
  33
  34 struct zip_dir_header {
  35         unsigned char magic[4];
  36         unsigned char creator_version[2];
  37         unsigned char version[2];
  38         unsigned char flags[2];
  39         unsigned char compression_method[2];
  40         unsigned char mtime[2];
  41         unsigned char mdate[2];
  42         unsigned char crc32[4];
  43         unsigned char compressed_size[4];
  44         unsigned char size[4];
  45         unsigned char filename_length[2];
  46         unsigned char extra_length[2];
  47         unsigned char comment_length[2];
  48         unsigned char disk[2];
  49         unsigned char attr1[2];
  50         unsigned char attr2[4];
  51         unsigned char offset[4];
  52         unsigned char _end[1];
  53 };
  54
  55 struct zip_dir_trailer {
  56         unsigned char magic[4];
  57         unsigned char disk[2];
  58         unsigned char directory_start_disk[2];
  59         unsigned char entries_on_this_disk[2];
  60         unsigned char entries[2];
  61         unsigned char size[4];
  62         unsigned char offset[4];
  63         unsigned char comment_length[2];
  64         unsigned char _end[1];
  65 };
  66
  67 /*
  68  * On ARM, padding is added at the end of the struct, so a simple
  69  * sizeof(struct ...) reports two bytes more than the payload size
  70  * we're interested in.
  71  */
  72 #define ZIP_LOCAL_HEADER_SIZE   offsetof(struct zip_local_header, _end)
  73 #define ZIP_DIR_HEADER_SIZE     offsetof(struct zip_dir_header, _end)
  74 #define ZIP_DIR_TRAILER_SIZE    offsetof(struct zip_dir_trailer, _end)
  75
  76 static void copy_le16(unsigned char *dest, unsigned int n)
  77 {
  78         dest[0] = 0xff & n;
  79         dest[1] = 0xff & (n >> 010);
  80 }
  81
  82 static void copy_le32(unsigned char *dest, unsigned int n)
  83 {
  84         dest[0] = 0xff & n;
  85         dest[1] = 0xff & (n >> 010);
  86         dest[2] = 0xff & (n >> 020);
  87         dest[3] = 0xff & (n >> 030);
  88 }
  89
  90 static void *zlib_deflate(void *data, unsigned long size,
  91                 int compression_level, unsigned long *compressed_size)
  92 {
  93         git_zstream stream;
  94         unsigned long maxsize;
  95         void *buffer;
  96         int result;
  97
  98         memset(&stream, 0, sizeof(stream));
  99         git_deflate_init(&stream, compression_level);
 100         maxsize = git_deflate_bound(&stream, size);
 101         buffer = xmalloc(maxsize);
 102
 103         stream.next_in = data;
 104         stream.avail_in = size;
 105         stream.next_out = buffer;
 106         stream.avail_out = maxsize;
 107
 108         do {
 109                 result = git_deflate(&stream, Z_FINISH);
 110         } while (result == Z_OK);
 111
 112         if (result != Z_STREAM_END) {
 113                 free(buffer);
 114                 return NULL;
 115         }
 116
 117         git_deflate_end(&stream);
 118         *compressed_size = stream.total_out;
 119
 120         return buffer;
 121 }
 122
 123 static int write_zip_entry(struct archiver_args *args,
 124                 const unsigned char *sha1, const char *path, size_t pathlen,
 125                 unsigned int mode, void *buffer, unsigned long size)
 126 {
 127         struct zip_local_header header;
 128         struct zip_dir_header dirent;
 129         unsigned long attr2;
 130         unsigned long compressed_size;
 131         unsigned long uncompressed_size;
 132         unsigned long crc;
 133         unsigned long direntsize;
 134         int method;
 135         unsigned char *out;
 136         void *deflated = NULL;
 137
 138         crc = crc32(0, NULL, 0);
 139
 140         if (pathlen > 0xffff) {
 141                 return error("path too long (%d chars, SHA1: %s): %s",
 142                                 (int)pathlen, sha1_to_hex(sha1), path);
 143         }
 144
 145         if (S_ISDIR(mode) || S_ISGITLINK(mode)) {
 146                 method = 0;
 147                 attr2 = 16;
 148                 out = NULL;
 149                 uncompressed_size = 0;
 150                 compressed_size = 0;
 151         } else if (S_ISREG(mode) || S_ISLNK(mode)) {
 152                 method = 0;
 153                 attr2 = S_ISLNK(mode) ? ((mode | 0777) << 16) :
 154                         (mode & 0111) ? ((mode) << 16) : 0;
 155                 if (S_ISREG(mode) && args->compression_level != 0)
 156                         method = 8;
 157                 crc = crc32(crc, buffer, size);
 158                 out = buffer;
 159                 uncompressed_size = size;
 160                 compressed_size = size;
 161         } else {
 162                 return error("unsupported file mode: 0%o (SHA1: %s)", mode,
 163                                 sha1_to_hex(sha1));
 164         }
 165
 166         if (method == 8) {
 167                 deflated = zlib_deflate(buffer, size, args->compression_level,
 168                                 &compressed_size);
 169                 if (deflated && compressed_size - 6 < size) {
 170                         /* ZLIB --> raw compressed data (see RFC 1950) */
 171                         /* CMF and FLG ... */
 172                         out = (unsigned char *)deflated + 2;
 173                         compressed_size -= 6;   /* ... and ADLER32 */
 174                 } else {
 175                         method = 0;
 176                         compressed_size = size;
 177                 }
 178         }
 179
 180         /* make sure we have enough free space in the dictionary */
 181         direntsize = ZIP_DIR_HEADER_SIZE + pathlen;
 182         while (zip_dir_size < zip_dir_offset + direntsize) {
 183                 zip_dir_size += ZIP_DIRECTORY_MIN_SIZE;
 184                 zip_dir = xrealloc(zip_dir, zip_dir_size);
 185         }
 186
 187         copy_le32(dirent.magic, 0x02014b50);
 188         copy_le16(dirent.creator_version,
 189                 S_ISLNK(mode) || (S_ISREG(mode) && (mode & 0111)) ? 0x0317 : 0);
 190         copy_le16(dirent.version, 10);
 191         copy_le16(dirent.flags, 0);
 192         copy_le16(dirent.compression_method, method);
 193         copy_le16(dirent.mtime, zip_time);
 194         copy_le16(dirent.mdate, zip_date);
 195         copy_le32(dirent.crc32, crc);
 196         copy_le32(dirent.compressed_size, compressed_size);
 197         copy_le32(dirent.size, uncompressed_size);
 198         copy_le16(dirent.filename_length, pathlen);
 199         copy_le16(dirent.extra_length, 0);
 200         copy_le16(dirent.comment_length, 0);
 201         copy_le16(dirent.disk, 0);
 202         copy_le16(dirent.attr1, 0);
 203         copy_le32(dirent.attr2, attr2);
 204         copy_le32(dirent.offset, zip_offset);
 205         memcpy(zip_dir + zip_dir_offset, &dirent, ZIP_DIR_HEADER_SIZE);
 206         zip_dir_offset += ZIP_DIR_HEADER_SIZE;
 207         memcpy(zip_dir + zip_dir_offset, path, pathlen);
 208         zip_dir_offset += pathlen;
 209         zip_dir_entries++;
 210
 211         copy_le32(header.magic, 0x04034b50);
 212         copy_le16(header.version, 10);
 213         copy_le16(header.flags, 0);
 214         copy_le16(header.compression_method, method);
 215         copy_le16(header.mtime, zip_time);
 216         copy_le16(header.mdate, zip_date);
 217         copy_le32(header.crc32, crc);
 218         copy_le32(header.compressed_size, compressed_size);
 219         copy_le32(header.size, uncompressed_size);
 220         copy_le16(header.filename_length, pathlen);
 221         copy_le16(header.extra_length, 0);
 222         write_or_die(1, &header, ZIP_LOCAL_HEADER_SIZE);
 223         zip_offset += ZIP_LOCAL_HEADER_SIZE;
 224         write_or_die(1, path, pathlen);
 225         zip_offset += pathlen;
 226         if (compressed_size > 0) {
 227                 write_or_die(1, out, compressed_size);
 228                 zip_offset += compressed_size;
 229         }
 230
 231         free(deflated);
 232
 233         return 0;
 234 }
 235
 236 static void write_zip_trailer(const unsigned char *sha1)
 237 {
 238         struct zip_dir_trailer trailer;
 239
 240         copy_le32(trailer.magic, 0x06054b50);
 241         copy_le16(trailer.disk, 0);
 242         copy_le16(trailer.directory_start_disk, 0);
 243         copy_le16(trailer.entries_on_this_disk, zip_dir_entries);
 244         copy_le16(trailer.entries, zip_dir_entries);
 245         copy_le32(trailer.size, zip_dir_offset);
 246         copy_le32(trailer.offset, zip_offset);
 247         copy_le16(trailer.comment_length, sha1 ? 40 : 0);
 248
 249         write_or_die(1, zip_dir, zip_dir_offset);
 250         write_or_die(1, &trailer, ZIP_DIR_TRAILER_SIZE);
 251         if (sha1)
 252                 write_or_die(1, sha1_to_hex(sha1), 40);
 253 }
 254
 255 static void dos_time(time_t *time, int *dos_date, int *dos_time)
 256 {
 257         struct tm *t = localtime(time);
 258
 259         *dos_date = t->tm_mday + (t->tm_mon + 1) * 32 +
 260                     (t->tm_year + 1900 - 1980) * 512;
 261         *dos_time = t->tm_sec / 2 + t->tm_min * 32 + t->tm_hour * 2048;
 262 }
 263
 264 int write_zip_archive(struct archiver_args *args)
 265 {
 266         int err;
 267
 268         dos_time(&args->time, &zip_date, &zip_time);
 269
 270         zip_dir = xmalloc(ZIP_DIRECTORY_MIN_SIZE);
 271         zip_dir_size = ZIP_DIRECTORY_MIN_SIZE;
 272
 273         err = write_archive_entries(args, write_zip_entry);
 274         if (!err)
 275                 write_zip_trailer(args->commit_sha1);
 276
 277         free(zip_dir);
 278
 279         return err;
 280 }