Andrew's git - gitweb.git/blob

400ba38c7d601f1cab2b4e28400cf565d4d69bef
   1/*
   2 * Copyright (c) 2006 Rene Scharfe
   3 */
   4#include "cache.h"
   5#include "archive.h"
   6
   7static int zip_date;
   8static int zip_time;
   9
  10static unsigned char *zip_dir;
  11static unsigned int zip_dir_size;
  12
  13static unsigned int zip_offset;
  14static unsigned int zip_dir_offset;
  15static unsigned int zip_dir_entries;
  16
  17#define ZIP_DIRECTORY_MIN_SIZE  (1024 * 1024)
  18
  19struct 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
  34struct 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
  55struct 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
  76static void copy_le16(unsigned char *dest, unsigned int n)
  77{
  78        dest[0] = 0xff & n;
  79        dest[1] = 0xff & (n >> 010);
  80}
  81
  82static 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
  90static 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
 123static int write_zip_entry(struct archiver_args *args,
 124                           const unsigned char *sha1,
 125                           const char *path, size_t pathlen,
 126                           unsigned int mode)
 127{
 128        struct zip_local_header header;
 129        struct zip_dir_header dirent;
 130        unsigned long attr2;
 131        unsigned long compressed_size;
 132        unsigned long crc;
 133        unsigned long direntsize;
 134        int method;
 135        unsigned char *out;
 136        void *deflated = NULL;
 137        void *buffer;
 138        unsigned long size;
 139
 140        crc = crc32(0, NULL, 0);
 141
 142        if (pathlen > 0xffff) {
 143                return error("path too long (%d chars, SHA1: %s): %s",
 144                                (int)pathlen, sha1_to_hex(sha1), path);
 145        }
 146
 147        if (S_ISDIR(mode) || S_ISGITLINK(mode)) {
 148                method = 0;
 149                attr2 = 16;
 150                out = NULL;
 151                size = 0;
 152                compressed_size = 0;
 153                buffer = NULL;
 154                size = 0;
 155        } else if (S_ISREG(mode) || S_ISLNK(mode)) {
 156                enum object_type type;
 157                buffer = sha1_file_to_archive(args, path, sha1, mode, &type, &size);
 158                if (!buffer)
 159                        return error("cannot read %s", sha1_to_hex(sha1));
 160
 161                method = 0;
 162                attr2 = S_ISLNK(mode) ? ((mode | 0777) << 16) :
 163                        (mode & 0111) ? ((mode) << 16) : 0;
 164                if (S_ISREG(mode) && args->compression_level != 0)
 165                        method = 8;
 166                crc = crc32(crc, buffer, size);
 167                out = buffer;
 168                compressed_size = size;
 169        } else {
 170                return error("unsupported file mode: 0%o (SHA1: %s)", mode,
 171                                sha1_to_hex(sha1));
 172        }
 173
 174        if (method == 8) {
 175                deflated = zlib_deflate(buffer, size, args->compression_level,
 176                                &compressed_size);
 177                if (deflated && compressed_size - 6 < size) {
 178                        /* ZLIB --> raw compressed data (see RFC 1950) */
 179                        /* CMF and FLG ... */
 180                        out = (unsigned char *)deflated + 2;
 181                        compressed_size -= 6;   /* ... and ADLER32 */
 182                } else {
 183                        method = 0;
 184                        compressed_size = size;
 185                }
 186        }
 187
 188        /* make sure we have enough free space in the dictionary */
 189        direntsize = ZIP_DIR_HEADER_SIZE + pathlen;
 190        while (zip_dir_size < zip_dir_offset + direntsize) {
 191                zip_dir_size += ZIP_DIRECTORY_MIN_SIZE;
 192                zip_dir = xrealloc(zip_dir, zip_dir_size);
 193        }
 194
 195        copy_le32(dirent.magic, 0x02014b50);
 196        copy_le16(dirent.creator_version,
 197                S_ISLNK(mode) || (S_ISREG(mode) && (mode & 0111)) ? 0x0317 : 0);
 198        copy_le16(dirent.version, 10);
 199        copy_le16(dirent.flags, 0);
 200        copy_le16(dirent.compression_method, method);
 201        copy_le16(dirent.mtime, zip_time);
 202        copy_le16(dirent.mdate, zip_date);
 203        copy_le32(dirent.crc32, crc);
 204        copy_le32(dirent.compressed_size, compressed_size);
 205        copy_le32(dirent.size, size);
 206        copy_le16(dirent.filename_length, pathlen);
 207        copy_le16(dirent.extra_length, 0);
 208        copy_le16(dirent.comment_length, 0);
 209        copy_le16(dirent.disk, 0);
 210        copy_le16(dirent.attr1, 0);
 211        copy_le32(dirent.attr2, attr2);
 212        copy_le32(dirent.offset, zip_offset);
 213        memcpy(zip_dir + zip_dir_offset, &dirent, ZIP_DIR_HEADER_SIZE);
 214        zip_dir_offset += ZIP_DIR_HEADER_SIZE;
 215        memcpy(zip_dir + zip_dir_offset, path, pathlen);
 216        zip_dir_offset += pathlen;
 217        zip_dir_entries++;
 218
 219        copy_le32(header.magic, 0x04034b50);
 220        copy_le16(header.version, 10);
 221        copy_le16(header.flags, 0);
 222        copy_le16(header.compression_method, method);
 223        copy_le16(header.mtime, zip_time);
 224        copy_le16(header.mdate, zip_date);
 225        copy_le32(header.crc32, crc);
 226        copy_le32(header.compressed_size, compressed_size);
 227        copy_le32(header.size, size);
 228        copy_le16(header.filename_length, pathlen);
 229        copy_le16(header.extra_length, 0);
 230        write_or_die(1, &header, ZIP_LOCAL_HEADER_SIZE);
 231        zip_offset += ZIP_LOCAL_HEADER_SIZE;
 232        write_or_die(1, path, pathlen);
 233        zip_offset += pathlen;
 234        if (compressed_size > 0) {
 235                write_or_die(1, out, compressed_size);
 236                zip_offset += compressed_size;
 237        }
 238
 239        free(deflated);
 240        free(buffer);
 241
 242        return 0;
 243}
 244
 245static void write_zip_trailer(const unsigned char *sha1)
 246{
 247        struct zip_dir_trailer trailer;
 248
 249        copy_le32(trailer.magic, 0x06054b50);
 250        copy_le16(trailer.disk, 0);
 251        copy_le16(trailer.directory_start_disk, 0);
 252        copy_le16(trailer.entries_on_this_disk, zip_dir_entries);
 253        copy_le16(trailer.entries, zip_dir_entries);
 254        copy_le32(trailer.size, zip_dir_offset);
 255        copy_le32(trailer.offset, zip_offset);
 256        copy_le16(trailer.comment_length, sha1 ? 40 : 0);
 257
 258        write_or_die(1, zip_dir, zip_dir_offset);
 259        write_or_die(1, &trailer, ZIP_DIR_TRAILER_SIZE);
 260        if (sha1)
 261                write_or_die(1, sha1_to_hex(sha1), 40);
 262}
 263
 264static void dos_time(time_t *time, int *dos_date, int *dos_time)
 265{
 266        struct tm *t = localtime(time);
 267
 268        *dos_date = t->tm_mday + (t->tm_mon + 1) * 32 +
 269                    (t->tm_year + 1900 - 1980) * 512;
 270        *dos_time = t->tm_sec / 2 + t->tm_min * 32 + t->tm_hour * 2048;
 271}
 272
 273static int write_zip_archive(const struct archiver *ar,
 274                             struct archiver_args *args)
 275{
 276        int err;
 277
 278        dos_time(&args->time, &zip_date, &zip_time);
 279
 280        zip_dir = xmalloc(ZIP_DIRECTORY_MIN_SIZE);
 281        zip_dir_size = ZIP_DIRECTORY_MIN_SIZE;
 282
 283        err = write_archive_entries(args, write_zip_entry);
 284        if (!err)
 285                write_zip_trailer(args->commit_sha1);
 286
 287        free(zip_dir);
 288
 289        return err;
 290}
 291
 292static struct archiver zip_archiver = {
 293        "zip",
 294        write_zip_archive,
 295        ARCHIVER_WANT_COMPRESSION_LEVELS|ARCHIVER_REMOTE
 296};
 297
 298void init_zip_archiver(void)
 299{
 300        register_archiver(&zip_archiver);
 301}