archive-zip.c

   1 /*
   2  * Copyright (c) 2006 Rene Scharfe
   3  */
   4 #include "cache.h"
   5 #include "commit.h"
   6 #include "blob.h"
   7 #include "tree.h"
   8 #include "quote.h"
   9 #include "builtin.h"
  10 #include "archive.h"
  11
  12 static int zip_date;
  13 static int zip_time;
  14
  15 static unsigned char *zip_dir;
  16 static unsigned int zip_dir_size;
  17
  18 static unsigned int zip_offset;
  19 static unsigned int zip_dir_offset;
  20 static unsigned int zip_dir_entries;
  21
  22 #define ZIP_DIRECTORY_MIN_SIZE  (1024 * 1024)
  23
  24 struct zip_local_header {
  25         unsigned char magic[4];
  26         unsigned char version[2];
  27         unsigned char flags[2];
  28         unsigned char compression_method[2];
  29         unsigned char mtime[2];
  30         unsigned char mdate[2];
  31         unsigned char crc32[4];
  32         unsigned char compressed_size[4];
  33         unsigned char size[4];
  34         unsigned char filename_length[2];
  35         unsigned char extra_length[2];
  36         unsigned char _end[1];
  37 };
  38
  39 struct zip_dir_header {
  40         unsigned char magic[4];
  41         unsigned char creator_version[2];
  42         unsigned char version[2];
  43         unsigned char flags[2];
  44         unsigned char compression_method[2];
  45         unsigned char mtime[2];
  46         unsigned char mdate[2];
  47         unsigned char crc32[4];
  48         unsigned char compressed_size[4];
  49         unsigned char size[4];
  50         unsigned char filename_length[2];
  51         unsigned char extra_length[2];
  52         unsigned char comment_length[2];
  53         unsigned char disk[2];
  54         unsigned char attr1[2];
  55         unsigned char attr2[4];
  56         unsigned char offset[4];
  57         unsigned char _end[1];
  58 };
  59
  60 struct zip_dir_trailer {
  61         unsigned char magic[4];
  62         unsigned char disk[2];
  63         unsigned char directory_start_disk[2];
  64         unsigned char entries_on_this_disk[2];
  65         unsigned char entries[2];
  66         unsigned char size[4];
  67         unsigned char offset[4];
  68         unsigned char comment_length[2];
  69         unsigned char _end[1];
  70 };
  71
  72 /*
  73  * On ARM, padding is added at the end of the struct, so a simple
  74  * sizeof(struct ...) reports two bytes more than the payload size
  75  * we're interested in.
  76  */
  77 #define ZIP_LOCAL_HEADER_SIZE   offsetof(struct zip_local_header, _end)
  78 #define ZIP_DIR_HEADER_SIZE     offsetof(struct zip_dir_header, _end)
  79 #define ZIP_DIR_TRAILER_SIZE    offsetof(struct zip_dir_trailer, _end)
  80
  81 static void copy_le16(unsigned char *dest, unsigned int n)
  82 {
  83         dest[0] = 0xff & n;
  84         dest[1] = 0xff & (n >> 010);
  85 }
  86
  87 static void copy_le32(unsigned char *dest, unsigned int n)
  88 {
  89         dest[0] = 0xff & n;
  90         dest[1] = 0xff & (n >> 010);
  91         dest[2] = 0xff & (n >> 020);
  92         dest[3] = 0xff & (n >> 030);
  93 }
  94
  95 static void *zlib_deflate(void *data, unsigned long size,
  96                           unsigned long *compressed_size)
  97 {
  98         z_stream stream;
  99         unsigned long maxsize;
 100         void *buffer;
 101         int result;
 102
 103         memset(&stream, 0, sizeof(stream));
 104         deflateInit(&stream, zlib_compression_level);
 105         maxsize = deflateBound(&stream, size);
 106         buffer = xmalloc(maxsize);
 107
 108         stream.next_in = data;
 109         stream.avail_in = size;
 110         stream.next_out = buffer;
 111         stream.avail_out = maxsize;
 112
 113         do {
 114                 result = deflate(&stream, Z_FINISH);
 115         } while (result == Z_OK);
 116
 117         if (result != Z_STREAM_END) {
 118                 free(buffer);
 119                 return NULL;
 120         }
 121
 122         deflateEnd(&stream);
 123         *compressed_size = stream.total_out;
 124
 125         return buffer;
 126 }
 127
 128 static int write_zip_entry(struct archiver_args *args,
 129                 const unsigned char *sha1, const char *path, size_t pathlen,
 130                 unsigned int mode, void *buffer, unsigned long size)
 131 {
 132         struct zip_local_header header;
 133         struct zip_dir_header dirent;
 134         unsigned long attr2;
 135         unsigned long compressed_size;
 136         unsigned long uncompressed_size;
 137         unsigned long crc;
 138         unsigned long direntsize;
 139         int method;
 140         unsigned char *out;
 141         void *deflated = NULL;
 142
 143         crc = crc32(0, NULL, 0);
 144
 145         if (pathlen > 0xffff) {
 146                 return error("path too long (%d chars, SHA1: %s): %s",
 147                                 (int)pathlen, sha1_to_hex(sha1), path);
 148         }
 149
 150         if (S_ISDIR(mode) || S_ISGITLINK(mode)) {
 151                 method = 0;
 152                 attr2 = 16;
 153                 out = NULL;
 154                 uncompressed_size = 0;
 155                 compressed_size = 0;
 156         } else if (S_ISREG(mode) || S_ISLNK(mode)) {
 157                 method = 0;
 158                 attr2 = S_ISLNK(mode) ? ((mode | 0777) << 16) :
 159                         (mode & 0111) ? ((mode) << 16) : 0;
 160                 if (S_ISREG(mode) && zlib_compression_level != 0)
 161                         method = 8;
 162                 crc = crc32(crc, buffer, size);
 163                 out = buffer;
 164                 uncompressed_size = size;
 165                 compressed_size = size;
 166         } else {
 167                 return error("unsupported file mode: 0%o (SHA1: %s)", mode,
 168                                 sha1_to_hex(sha1));
 169         }
 170
 171         if (method == 8) {
 172                 deflated = zlib_deflate(buffer, size, &compressed_size);
 173                 if (deflated && compressed_size - 6 < size) {
 174                         /* ZLIB --> raw compressed data (see RFC 1950) */
 175                         /* CMF and FLG ... */
 176                         out = (unsigned char *)deflated + 2;
 177                         compressed_size -= 6;   /* ... and ADLER32 */
 178                 } else {
 179                         method = 0;
 180                         compressed_size = size;
 181                 }
 182         }
 183
 184         /* make sure we have enough free space in the dictionary */
 185         direntsize = ZIP_DIR_HEADER_SIZE + pathlen;
 186         while (zip_dir_size < zip_dir_offset + direntsize) {
 187                 zip_dir_size += ZIP_DIRECTORY_MIN_SIZE;
 188                 zip_dir = xrealloc(zip_dir, zip_dir_size);
 189         }
 190
 191         copy_le32(dirent.magic, 0x02014b50);
 192         copy_le16(dirent.creator_version,
 193                 S_ISLNK(mode) || (S_ISREG(mode) && (mode & 0111)) ? 0x0317 : 0);
 194         copy_le16(dirent.version, 10);
 195         copy_le16(dirent.flags, 0);
 196         copy_le16(dirent.compression_method, method);
 197         copy_le16(dirent.mtime, zip_time);
 198         copy_le16(dirent.mdate, zip_date);
 199         copy_le32(dirent.crc32, crc);
 200         copy_le32(dirent.compressed_size, compressed_size);
 201         copy_le32(dirent.size, uncompressed_size);
 202         copy_le16(dirent.filename_length, pathlen);
 203         copy_le16(dirent.extra_length, 0);
 204         copy_le16(dirent.comment_length, 0);
 205         copy_le16(dirent.disk, 0);
 206         copy_le16(dirent.attr1, 0);
 207         copy_le32(dirent.attr2, attr2);
 208         copy_le32(dirent.offset, zip_offset);
 209         memcpy(zip_dir + zip_dir_offset, &dirent, ZIP_DIR_HEADER_SIZE);
 210         zip_dir_offset += ZIP_DIR_HEADER_SIZE;
 211         memcpy(zip_dir + zip_dir_offset, path, pathlen);
 212         zip_dir_offset += pathlen;
 213         zip_dir_entries++;
 214
 215         copy_le32(header.magic, 0x04034b50);
 216         copy_le16(header.version, 10);
 217         copy_le16(header.flags, 0);
 218         copy_le16(header.compression_method, method);
 219         copy_le16(header.mtime, zip_time);
 220         copy_le16(header.mdate, zip_date);
 221         copy_le32(header.crc32, crc);
 222         copy_le32(header.compressed_size, compressed_size);
 223         copy_le32(header.size, uncompressed_size);
 224         copy_le16(header.filename_length, pathlen);
 225         copy_le16(header.extra_length, 0);
 226         write_or_die(1, &header, ZIP_LOCAL_HEADER_SIZE);
 227         zip_offset += ZIP_LOCAL_HEADER_SIZE;
 228         write_or_die(1, path, pathlen);
 229         zip_offset += pathlen;
 230         if (compressed_size > 0) {
 231                 write_or_die(1, out, compressed_size);
 232                 zip_offset += compressed_size;
 233         }
 234
 235         free(deflated);
 236
 237         return 0;
 238 }
 239
 240 static void write_zip_trailer(const unsigned char *sha1)
 241 {
 242         struct zip_dir_trailer trailer;
 243
 244         copy_le32(trailer.magic, 0x06054b50);
 245         copy_le16(trailer.disk, 0);
 246         copy_le16(trailer.directory_start_disk, 0);
 247         copy_le16(trailer.entries_on_this_disk, zip_dir_entries);
 248         copy_le16(trailer.entries, zip_dir_entries);
 249         copy_le32(trailer.size, zip_dir_offset);
 250         copy_le32(trailer.offset, zip_offset);
 251         copy_le16(trailer.comment_length, sha1 ? 40 : 0);
 252
 253         write_or_die(1, zip_dir, zip_dir_offset);
 254         write_or_die(1, &trailer, ZIP_DIR_TRAILER_SIZE);
 255         if (sha1)
 256                 write_or_die(1, sha1_to_hex(sha1), 40);
 257 }
 258
 259 static void dos_time(time_t *time, int *dos_date, int *dos_time)
 260 {
 261         struct tm *t = localtime(time);
 262
 263         *dos_date = t->tm_mday + (t->tm_mon + 1) * 32 +
 264                     (t->tm_year + 1900 - 1980) * 512;
 265         *dos_time = t->tm_sec / 2 + t->tm_min * 32 + t->tm_hour * 2048;
 266 }
 267
 268 int write_zip_archive(struct archiver_args *args)
 269 {
 270         int err;
 271
 272         dos_time(&args->time, &zip_date, &zip_time);
 273
 274         zip_dir = xmalloc(ZIP_DIRECTORY_MIN_SIZE);
 275         zip_dir_size = ZIP_DIRECTORY_MIN_SIZE;
 276
 277         err = write_archive_entries(args, write_zip_entry);
 278         if (!err)
 279                 write_zip_trailer(args->commit_sha1);
 280
 281         free(zip_dir);
 282
 283         return err;
 284 }