root/archive-zip.c

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DEFINITIONS

This source file includes following definitions.
  1. copy_le16
  2. copy_le32
  3. copy_le64
  4. clamp_max
  5. copy_le16_clamp
  6. zlib_deflate_raw
  7. write_zip_data_desc
  8. set_zip_dir_data_desc
  9. set_zip_header_data_desc
  10. has_only_ascii
  11. entry_is_binary
  12. write_zip_entry
  13. write_zip64_trailer
  14. write_zip_trailer
  15. dos_time
  16. write_zip_archive
  17. init_zip_archiver

/*
 * Copyright (c) 2006 Rene Scharfe
 */
#include "cache.h"
#include "archive.h"
#include "streaming.h"
#include "utf8.h"
#include "userdiff.h"
#include "xdiff-interface.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 uint64_t zip_dir_entries;

static unsigned int max_creator_version;

#define ZIP_DIRECTORY_MIN_SIZE  (1024 * 1024)
#define ZIP_STREAM      (1 <<  3)
#define ZIP_UTF8        (1 << 11)

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_data_desc {
        unsigned char magic[4];
        unsigned char crc32[4];
        unsigned char compressed_size[4];
        unsigned char size[4];
        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];
};

struct zip_extra_mtime {
        unsigned char magic[2];
        unsigned char extra_size[2];
        unsigned char flags[1];
        unsigned char mtime[4];
        unsigned char _end[1];
};

struct zip64_dir_trailer {
        unsigned char magic[4];
        unsigned char record_size[8];
        unsigned char creator_version[2];
        unsigned char version[2];
        unsigned char disk[4];
        unsigned char directory_start_disk[4];
        unsigned char entries_on_this_disk[8];
        unsigned char entries[8];
        unsigned char size[8];
        unsigned char offset[8];
        unsigned char _end[1];
};

struct zip64_dir_trailer_locator {
        unsigned char magic[4];
        unsigned char disk[4];
        unsigned char offset[8];
        unsigned char number_of_disks[4];
        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_DATA_DESC_SIZE      offsetof(struct zip_data_desc, _end)
#define ZIP_DIR_HEADER_SIZE     offsetof(struct zip_dir_header, _end)
#define ZIP_DIR_TRAILER_SIZE    offsetof(struct zip_dir_trailer, _end)
#define ZIP_EXTRA_MTIME_SIZE    offsetof(struct zip_extra_mtime, _end)
#define ZIP_EXTRA_MTIME_PAYLOAD_SIZE \
        (ZIP_EXTRA_MTIME_SIZE - offsetof(struct zip_extra_mtime, flags))
#define ZIP64_DIR_TRAILER_SIZE  offsetof(struct zip64_dir_trailer, _end)
#define ZIP64_DIR_TRAILER_RECORD_SIZE \
        (ZIP64_DIR_TRAILER_SIZE - \
         offsetof(struct zip64_dir_trailer, creator_version))
#define ZIP64_DIR_TRAILER_LOCATOR_SIZE \
        offsetof(struct zip64_dir_trailer_locator, _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 copy_le64(unsigned char *dest, uint64_t n)
{
        dest[0] = 0xff & n;
        dest[1] = 0xff & (n >> 010);
        dest[2] = 0xff & (n >> 020);
        dest[3] = 0xff & (n >> 030);
        dest[4] = 0xff & (n >> 040);
        dest[5] = 0xff & (n >> 050);
        dest[6] = 0xff & (n >> 060);
        dest[7] = 0xff & (n >> 070);
}

static uint64_t clamp_max(uint64_t n, uint64_t max, int *clamped)
{
        if (n <= max)
                return n;
        *clamped = 1;
        return max;
}

static void copy_le16_clamp(unsigned char *dest, uint64_t n, int *clamped)
{
        copy_le16(dest, clamp_max(n, 0xffff, clamped));
}

static void *zlib_deflate_raw(void *data, unsigned long size,
                              int compression_level,
                              unsigned long *compressed_size)
{
        git_zstream stream;
        unsigned long maxsize;
        void *buffer;
        int result;

        git_deflate_init_raw(&stream, compression_level);
        maxsize = git_deflate_bound(&stream, size);
        buffer = xmalloc(maxsize);

        stream.next_in = data;
        stream.avail_in = size;
        stream.next_out = buffer;
        stream.avail_out = maxsize;

        do {
                result = git_deflate(&stream, Z_FINISH);
        } while (result == Z_OK);

        if (result != Z_STREAM_END) {
                free(buffer);
                return NULL;
        }

        git_deflate_end(&stream);
        *compressed_size = stream.total_out;

        return buffer;
}

static void write_zip_data_desc(unsigned long size,
                                unsigned long compressed_size,
                                unsigned long crc)
{
        struct zip_data_desc trailer;

        copy_le32(trailer.magic, 0x08074b50);
        copy_le32(trailer.crc32, crc);
        copy_le32(trailer.compressed_size, compressed_size);
        copy_le32(trailer.size, size);
        write_or_die(1, &trailer, ZIP_DATA_DESC_SIZE);
}

static void set_zip_dir_data_desc(struct zip_dir_header *header,
                                  unsigned long size,
                                  unsigned long compressed_size,
                                  unsigned long crc)
{
        copy_le32(header->crc32, crc);
        copy_le32(header->compressed_size, compressed_size);
        copy_le32(header->size, size);
}

static void set_zip_header_data_desc(struct zip_local_header *header,
                                     unsigned long size,
                                     unsigned long compressed_size,
                                     unsigned long crc)
{
        copy_le32(header->crc32, crc);
        copy_le32(header->compressed_size, compressed_size);
        copy_le32(header->size, size);
}

static int has_only_ascii(const char *s)
{
        for (;;) {
                int c = *s++;
                if (c == '\0')
                        return 1;
                if (!isascii(c))
                        return 0;
        }
}

static int entry_is_binary(const char *path, const void *buffer, size_t size)
{
        struct userdiff_driver *driver = userdiff_find_by_path(path);
        if (!driver)
                driver = userdiff_find_by_name("default");
        if (driver->binary != -1)
                return driver->binary;
        return buffer_is_binary(buffer, size);
}

#define STREAM_BUFFER_SIZE (1024 * 16)

static int write_zip_entry(struct archiver_args *args,
                           const unsigned char *sha1,
                           const char *path, size_t pathlen,
                           unsigned int mode)
{
        struct zip_local_header header;
        struct zip_dir_header dirent;
        struct zip_extra_mtime extra;
        unsigned long attr2;
        unsigned long compressed_size;
        unsigned long crc;
        unsigned long direntsize;
        int method;
        unsigned char *out;
        void *deflated = NULL;
        void *buffer;
        struct git_istream *stream = NULL;
        unsigned long flags = 0;
        unsigned long size;
        int is_binary = -1;
        const char *path_without_prefix = path + args->baselen;
        unsigned int creator_version = 0;

        crc = crc32(0, NULL, 0);

        if (!has_only_ascii(path)) {
                if (is_utf8(path))
                        flags |= ZIP_UTF8;
                else
                        warning("Path is not valid UTF-8: %s", path);
        }

        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;
                size = 0;
                compressed_size = 0;
                buffer = NULL;
        } else if (S_ISREG(mode) || S_ISLNK(mode)) {
                enum object_type type = sha1_object_info(sha1, &size);

                method = 0;
                attr2 = S_ISLNK(mode) ? ((mode | 0777) << 16) :
                        (mode & 0111) ? ((mode) << 16) : 0;
                if (S_ISLNK(mode) || (mode & 0111))
                        creator_version = 0x0317;
                if (S_ISREG(mode) && args->compression_level != 0 && size > 0)
                        method = 8;

                if (S_ISREG(mode) && type == OBJ_BLOB && !args->convert &&
                    size > big_file_threshold) {
                        stream = open_istream(sha1, &type, &size, NULL);
                        if (!stream)
                                return error("cannot stream blob %s",
                                             sha1_to_hex(sha1));
                        flags |= ZIP_STREAM;
                        out = buffer = NULL;
                } else {
                        buffer = sha1_file_to_archive(args, path, sha1, mode,
                                                      &type, &size);
                        if (!buffer)
                                return error("cannot read %s",
                                             sha1_to_hex(sha1));
                        crc = crc32(crc, buffer, size);
                        is_binary = entry_is_binary(path_without_prefix,
                                                    buffer, size);
                        out = buffer;
                }
                compressed_size = (method == 0) ? size : 0;
        } else {
                return error("unsupported file mode: 0%o (SHA1: %s)", mode,
                                sha1_to_hex(sha1));
        }

        if (creator_version > max_creator_version)
                max_creator_version = creator_version;

        if (buffer && method == 8) {
                out = deflated = zlib_deflate_raw(buffer, size,
                                                  args->compression_level,
                                                  &compressed_size);
                if (!out || compressed_size >= size) {
                        out = buffer;
                        method = 0;
                        compressed_size = size;
                }
        }

        copy_le16(extra.magic, 0x5455);
        copy_le16(extra.extra_size, ZIP_EXTRA_MTIME_PAYLOAD_SIZE);
        extra.flags[0] = 1;     /* just mtime */
        copy_le32(extra.mtime, args->time);

        /* make sure we have enough free space in the dictionary */
        direntsize = ZIP_DIR_HEADER_SIZE + pathlen + ZIP_EXTRA_MTIME_SIZE;
        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, creator_version);
        copy_le16(dirent.version, 10);
        copy_le16(dirent.flags, flags);
        copy_le16(dirent.compression_method, method);
        copy_le16(dirent.mtime, zip_time);
        copy_le16(dirent.mdate, zip_date);
        set_zip_dir_data_desc(&dirent, size, compressed_size, crc);
        copy_le16(dirent.filename_length, pathlen);
        copy_le16(dirent.extra_length, ZIP_EXTRA_MTIME_SIZE);
        copy_le16(dirent.comment_length, 0);
        copy_le16(dirent.disk, 0);
        copy_le32(dirent.attr2, attr2);
        copy_le32(dirent.offset, zip_offset);

        copy_le32(header.magic, 0x04034b50);
        copy_le16(header.version, 10);
        copy_le16(header.flags, flags);
        copy_le16(header.compression_method, method);
        copy_le16(header.mtime, zip_time);
        copy_le16(header.mdate, zip_date);
        set_zip_header_data_desc(&header, size, compressed_size, crc);
        copy_le16(header.filename_length, pathlen);
        copy_le16(header.extra_length, ZIP_EXTRA_MTIME_SIZE);
        write_or_die(1, &header, ZIP_LOCAL_HEADER_SIZE);
        zip_offset += ZIP_LOCAL_HEADER_SIZE;
        write_or_die(1, path, pathlen);
        zip_offset += pathlen;
        write_or_die(1, &extra, ZIP_EXTRA_MTIME_SIZE);
        zip_offset += ZIP_EXTRA_MTIME_SIZE;
        if (stream && method == 0) {
                unsigned char buf[STREAM_BUFFER_SIZE];
                ssize_t readlen;

                for (;;) {
                        readlen = read_istream(stream, buf, sizeof(buf));
                        if (readlen <= 0)
                                break;
                        crc = crc32(crc, buf, readlen);
                        if (is_binary == -1)
                                is_binary = entry_is_binary(path_without_prefix,
                                                            buf, readlen);
                        write_or_die(1, buf, readlen);
                }
                close_istream(stream);
                if (readlen)
                        return readlen;

                compressed_size = size;
                zip_offset += compressed_size;

                write_zip_data_desc(size, compressed_size, crc);
                zip_offset += ZIP_DATA_DESC_SIZE;

                set_zip_dir_data_desc(&dirent, size, compressed_size, crc);
        } else if (stream && method == 8) {
                unsigned char buf[STREAM_BUFFER_SIZE];
                ssize_t readlen;
                git_zstream zstream;
                int result;
                size_t out_len;
                unsigned char compressed[STREAM_BUFFER_SIZE * 2];

                git_deflate_init_raw(&zstream, args->compression_level);

                compressed_size = 0;
                zstream.next_out = compressed;
                zstream.avail_out = sizeof(compressed);

                for (;;) {
                        readlen = read_istream(stream, buf, sizeof(buf));
                        if (readlen <= 0)
                                break;
                        crc = crc32(crc, buf, readlen);
                        if (is_binary == -1)
                                is_binary = entry_is_binary(path_without_prefix,
                                                            buf, readlen);

                        zstream.next_in = buf;
                        zstream.avail_in = readlen;
                        result = git_deflate(&zstream, 0);
                        if (result != Z_OK)
                                die("deflate error (%d)", result);
                        out_len = zstream.next_out - compressed;

                        if (out_len > 0) {
                                write_or_die(1, compressed, out_len);
                                compressed_size += out_len;
                                zstream.next_out = compressed;
                                zstream.avail_out = sizeof(compressed);
                        }

                }
                close_istream(stream);
                if (readlen)
                        return readlen;

                zstream.next_in = buf;
                zstream.avail_in = 0;
                result = git_deflate(&zstream, Z_FINISH);
                if (result != Z_STREAM_END)
                        die("deflate error (%d)", result);

                git_deflate_end(&zstream);
                out_len = zstream.next_out - compressed;
                write_or_die(1, compressed, out_len);
                compressed_size += out_len;
                zip_offset += compressed_size;

                write_zip_data_desc(size, compressed_size, crc);
                zip_offset += ZIP_DATA_DESC_SIZE;

                set_zip_dir_data_desc(&dirent, size, compressed_size, crc);
        } else if (compressed_size > 0) {
                write_or_die(1, out, compressed_size);
                zip_offset += compressed_size;
        }

        free(deflated);
        free(buffer);

        copy_le16(dirent.attr1, !is_binary);

        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;
        memcpy(zip_dir + zip_dir_offset, &extra, ZIP_EXTRA_MTIME_SIZE);
        zip_dir_offset += ZIP_EXTRA_MTIME_SIZE;
        zip_dir_entries++;

        return 0;
}

static void write_zip64_trailer(void)
{
        struct zip64_dir_trailer trailer64;
        struct zip64_dir_trailer_locator locator64;

        copy_le32(trailer64.magic, 0x06064b50);
        copy_le64(trailer64.record_size, ZIP64_DIR_TRAILER_RECORD_SIZE);
        copy_le16(trailer64.creator_version, max_creator_version);
        copy_le16(trailer64.version, 45);
        copy_le32(trailer64.disk, 0);
        copy_le32(trailer64.directory_start_disk, 0);
        copy_le64(trailer64.entries_on_this_disk, zip_dir_entries);
        copy_le64(trailer64.entries, zip_dir_entries);
        copy_le64(trailer64.size, zip_dir_offset);
        copy_le64(trailer64.offset, zip_offset);

        copy_le32(locator64.magic, 0x07064b50);
        copy_le32(locator64.disk, 0);
        copy_le64(locator64.offset, zip_offset + zip_dir_offset);
        copy_le32(locator64.number_of_disks, 1);

        write_or_die(1, &trailer64, ZIP64_DIR_TRAILER_SIZE);
        write_or_die(1, &locator64, ZIP64_DIR_TRAILER_LOCATOR_SIZE);
}

static void write_zip_trailer(const unsigned char *sha1)
{
        struct zip_dir_trailer trailer;
        int clamped = 0;

        copy_le32(trailer.magic, 0x06054b50);
        copy_le16(trailer.disk, 0);
        copy_le16(trailer.directory_start_disk, 0);
        copy_le16_clamp(trailer.entries_on_this_disk, zip_dir_entries,
                        &clamped);
        copy_le16_clamp(trailer.entries, zip_dir_entries, &clamped);
        copy_le32(trailer.size, zip_dir_offset);
        copy_le32(trailer.offset, zip_offset);
        copy_le16(trailer.comment_length, sha1 ? GIT_SHA1_HEXSZ : 0);

        write_or_die(1, zip_dir, zip_dir_offset);
        if (clamped)
                write_zip64_trailer();
        write_or_die(1, &trailer, ZIP_DIR_TRAILER_SIZE);
        if (sha1)
                write_or_die(1, sha1_to_hex(sha1), GIT_SHA1_HEXSZ);
}

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;
}

static int write_zip_archive(const struct archiver *ar,
                             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;
}

static struct archiver zip_archiver = {
        "zip",
        write_zip_archive,
        ARCHIVER_WANT_COMPRESSION_LEVELS|ARCHIVER_REMOTE
};

void init_zip_archiver(void)
{
        register_archiver(&zip_archiver);
}

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