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git/archive-zip.c

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C
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/*
* Copyright (c) 2006 Rene Scharfe
*/
#include "cache.h"
#include "archive.h"
static int zip_date;
static int zip_time;
static unsigned char *zip_dir;
static unsigned int zip_dir_size;
static unsigned int zip_offset;
static unsigned int zip_dir_offset;
static unsigned int zip_dir_entries;
#define ZIP_DIRECTORY_MIN_SIZE (1024 * 1024)
struct zip_local_header {
unsigned char magic[4];
unsigned char version[2];
unsigned char flags[2];
unsigned char compression_method[2];
unsigned char mtime[2];
unsigned char mdate[2];
unsigned char crc32[4];
unsigned char compressed_size[4];
unsigned char size[4];
unsigned char filename_length[2];
unsigned char extra_length[2];
unsigned char _end[1];
};
struct zip_dir_header {
unsigned char magic[4];
unsigned char creator_version[2];
unsigned char version[2];
unsigned char flags[2];
unsigned char compression_method[2];
unsigned char mtime[2];
unsigned char mdate[2];
unsigned char crc32[4];
unsigned char compressed_size[4];
unsigned char size[4];
unsigned char filename_length[2];
unsigned char extra_length[2];
unsigned char comment_length[2];
unsigned char disk[2];
unsigned char attr1[2];
unsigned char attr2[4];
unsigned char offset[4];
unsigned char _end[1];
};
struct zip_dir_trailer {
unsigned char magic[4];
unsigned char disk[2];
unsigned char directory_start_disk[2];
unsigned char entries_on_this_disk[2];
unsigned char entries[2];
unsigned char size[4];
unsigned char offset[4];
unsigned char comment_length[2];
unsigned char _end[1];
};
/*
* On ARM, padding is added at the end of the struct, so a simple
* sizeof(struct ...) reports two bytes more than the payload size
* we're interested in.
*/
#define ZIP_LOCAL_HEADER_SIZE offsetof(struct zip_local_header, _end)
#define ZIP_DIR_HEADER_SIZE offsetof(struct zip_dir_header, _end)
#define ZIP_DIR_TRAILER_SIZE offsetof(struct zip_dir_trailer, _end)
static void copy_le16(unsigned char *dest, unsigned int n)
{
dest[0] = 0xff & n;
dest[1] = 0xff & (n >> 010);
}
static void copy_le32(unsigned char *dest, unsigned int n)
{
dest[0] = 0xff & n;
dest[1] = 0xff & (n >> 010);
dest[2] = 0xff & (n >> 020);
dest[3] = 0xff & (n >> 030);
}
static void *zlib_deflate(void *data, unsigned long size,
int compression_level, unsigned long *compressed_size)
{
z_stream stream;
unsigned long maxsize;
void *buffer;
int result;
memset(&stream, 0, sizeof(stream));
deflateInit(&stream, compression_level);
maxsize = deflateBound(&stream, size);
buffer = xmalloc(maxsize);
stream.next_in = data;
stream.avail_in = size;
stream.next_out = buffer;
stream.avail_out = maxsize;
do {
result = deflate(&stream, Z_FINISH);
} while (result == Z_OK);
if (result != Z_STREAM_END) {
free(buffer);
return NULL;
}
deflateEnd(&stream);
*compressed_size = stream.total_out;
return buffer;
}
static int write_zip_entry(struct archiver_args *args,
const unsigned char *sha1, const char *path, size_t pathlen,
unsigned int mode, void *buffer, unsigned long size)
{
struct zip_local_header header;
struct zip_dir_header dirent;
unsigned long attr2;
unsigned long compressed_size;
unsigned long uncompressed_size;
unsigned long crc;
unsigned long direntsize;
int method;
unsigned char *out;
void *deflated = NULL;
crc = crc32(0, NULL, 0);
if (pathlen > 0xffff) {
return error("path too long (%d chars, SHA1: %s): %s",
(int)pathlen, sha1_to_hex(sha1), path);
}
if (S_ISDIR(mode) || S_ISGITLINK(mode)) {
method = 0;
attr2 = 16;
out = NULL;
uncompressed_size = 0;
compressed_size = 0;
} else if (S_ISREG(mode) || S_ISLNK(mode)) {
method = 0;
attr2 = S_ISLNK(mode) ? ((mode | 0777) << 16) :
(mode & 0111) ? ((mode) << 16) : 0;
if (S_ISREG(mode) && args->compression_level != 0)
method = 8;
crc = crc32(crc, buffer, size);
out = buffer;
uncompressed_size = size;
compressed_size = size;
} else {
return error("unsupported file mode: 0%o (SHA1: %s)", mode,
sha1_to_hex(sha1));
}
if (method == 8) {
deflated = zlib_deflate(buffer, size, args->compression_level,
&compressed_size);
if (deflated && compressed_size - 6 < size) {
/* ZLIB --> raw compressed data (see RFC 1950) */
/* CMF and FLG ... */
out = (unsigned char *)deflated + 2;
compressed_size -= 6; /* ... and ADLER32 */
} else {
method = 0;
compressed_size = size;
}
}
/* make sure we have enough free space in the dictionary */
direntsize = ZIP_DIR_HEADER_SIZE + pathlen;
while (zip_dir_size < zip_dir_offset + direntsize) {
zip_dir_size += ZIP_DIRECTORY_MIN_SIZE;
zip_dir = xrealloc(zip_dir, zip_dir_size);
}
copy_le32(dirent.magic, 0x02014b50);
copy_le16(dirent.creator_version,
S_ISLNK(mode) || (S_ISREG(mode) && (mode & 0111)) ? 0x0317 : 0);
copy_le16(dirent.version, 10);
copy_le16(dirent.flags, 0);
copy_le16(dirent.compression_method, method);
copy_le16(dirent.mtime, zip_time);
copy_le16(dirent.mdate, zip_date);
copy_le32(dirent.crc32, crc);
copy_le32(dirent.compressed_size, compressed_size);
copy_le32(dirent.size, uncompressed_size);
copy_le16(dirent.filename_length, pathlen);
copy_le16(dirent.extra_length, 0);
copy_le16(dirent.comment_length, 0);
copy_le16(dirent.disk, 0);
copy_le16(dirent.attr1, 0);
copy_le32(dirent.attr2, attr2);
copy_le32(dirent.offset, zip_offset);
memcpy(zip_dir + zip_dir_offset, &dirent, ZIP_DIR_HEADER_SIZE);
zip_dir_offset += ZIP_DIR_HEADER_SIZE;
memcpy(zip_dir + zip_dir_offset, path, pathlen);
zip_dir_offset += pathlen;
zip_dir_entries++;
copy_le32(header.magic, 0x04034b50);
copy_le16(header.version, 10);
copy_le16(header.flags, 0);
copy_le16(header.compression_method, method);
copy_le16(header.mtime, zip_time);
copy_le16(header.mdate, zip_date);
copy_le32(header.crc32, crc);
copy_le32(header.compressed_size, compressed_size);
copy_le32(header.size, uncompressed_size);
copy_le16(header.filename_length, pathlen);
copy_le16(header.extra_length, 0);
write_or_die(1, &header, ZIP_LOCAL_HEADER_SIZE);
zip_offset += ZIP_LOCAL_HEADER_SIZE;
write_or_die(1, path, pathlen);
zip_offset += pathlen;
if (compressed_size > 0) {
write_or_die(1, out, compressed_size);
zip_offset += compressed_size;
}
free(deflated);
return 0;
}
static void write_zip_trailer(const unsigned char *sha1)
{
struct zip_dir_trailer trailer;
copy_le32(trailer.magic, 0x06054b50);
copy_le16(trailer.disk, 0);
copy_le16(trailer.directory_start_disk, 0);
copy_le16(trailer.entries_on_this_disk, zip_dir_entries);
copy_le16(trailer.entries, zip_dir_entries);
copy_le32(trailer.size, zip_dir_offset);
copy_le32(trailer.offset, zip_offset);
copy_le16(trailer.comment_length, sha1 ? 40 : 0);
write_or_die(1, zip_dir, zip_dir_offset);
write_or_die(1, &trailer, ZIP_DIR_TRAILER_SIZE);
if (sha1)
write_or_die(1, sha1_to_hex(sha1), 40);
}
static void dos_time(time_t *time, int *dos_date, int *dos_time)
{
struct tm *t = localtime(time);
*dos_date = t->tm_mday + (t->tm_mon + 1) * 32 +
(t->tm_year + 1900 - 1980) * 512;
*dos_time = t->tm_sec / 2 + t->tm_min * 32 + t->tm_hour * 2048;
}
int write_zip_archive(struct archiver_args *args)
{
int err;
dos_time(&args->time, &zip_date, &zip_time);
zip_dir = xmalloc(ZIP_DIRECTORY_MIN_SIZE);
zip_dir_size = ZIP_DIRECTORY_MIN_SIZE;
err = write_archive_entries(args, write_zip_entry);
if (!err)
write_zip_trailer(args->commit_sha1);
free(zip_dir);
return err;
}