Git 2.45-rc1

[git.git] / archive-zip.c

/*
 * Copyright (c) 2006 Rene Scharfe
 */
#include "git-compat-util.h"
#include "config.h"
#include "archive.h"
#include "gettext.h"
#include "git-zlib.h"
#include "hex.h"
#include "streaming.h"
#include "utf8.h"
#include "object-store-ll.h"
#include "strbuf.h"
#include "userdiff.h"
#include "write-or-die.h"
#include "xdiff-interface.h"
#include "date.h"

static int zip_date;
static int zip_time;

/* We only care about the "buf" part here. */
static struct strbuf zip_dir;

static uintmax_t zip_offset;
static uint64_t zip_dir_entries;

static unsigned int max_creator_version;

#define ZIP_STREAM      (1 <<  3)
#define ZIP_UTF8        (1 << 11)

enum zip_method {
        ZIP_METHOD_STORE = 0,
        ZIP_METHOD_DEFLATE = 8
};

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 zip64_data_desc {
        unsigned char magic[4];
        unsigned char crc32[4];
        unsigned char compressed_size[8];
        unsigned char size[8];
        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_extra {
        unsigned char magic[2];
        unsigned char extra_size[2];
        unsigned char size[8];
        unsigned char compressed_size[8];
        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 ZIP64_DATA_DESC_SIZE    offsetof(struct zip64_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_EXTRA_SIZE        offsetof(struct zip64_extra, _end)
#define ZIP64_EXTRA_PAYLOAD_SIZE \
        (ZIP64_EXTRA_SIZE - offsetof(struct zip64_extra, size))
#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 copy_le32_clamp(unsigned char *dest, uint64_t n, int *clamped)
{
        copy_le32(dest, clamp_max(n, 0xffffffff, clamped));
}

static int strbuf_add_le(struct strbuf *sb, size_t size, uintmax_t n)
{
        while (size-- > 0) {
                strbuf_addch(sb, n & 0xff);
                n >>= 8;
        }
        return -!!n;
}

static uint32_t clamp32(uintmax_t n)
{
        const uintmax_t max = 0xffffffff;
        return (n < max) ? n : max;
}

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)
{
        if (size >= 0xffffffff || compressed_size >= 0xffffffff) {
                struct zip64_data_desc trailer;
                copy_le32(trailer.magic, 0x08074b50);
                copy_le32(trailer.crc32, crc);
                copy_le64(trailer.compressed_size, compressed_size);
                copy_le64(trailer.size, size);
                write_or_die(1, &trailer, ZIP64_DATA_DESC_SIZE);
                zip_offset += ZIP64_DATA_DESC_SIZE;
        } else {
                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);
                zip_offset += ZIP_DATA_DESC_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(struct index_state *istate, const char *path,
                           const void *buffer, size_t size)
{
        struct userdiff_driver *driver = userdiff_find_by_path(istate, 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 struct object_id *oid,
                           const char *path, size_t pathlen,
                           unsigned int mode,
                           void *buffer, unsigned long size)
{
        struct zip_local_header header;
        uintmax_t offset = zip_offset;
        struct zip_extra_mtime extra;
        struct zip64_extra extra64;
        size_t header_extra_size = ZIP_EXTRA_MTIME_SIZE;
        int need_zip64_extra = 0;
        unsigned long attr2;
        unsigned long compressed_size;
        unsigned long crc;
        enum zip_method method;
        unsigned char *out;
        void *deflated = NULL;
        struct git_istream *stream = NULL;
        unsigned long flags = 0;
        int is_binary = -1;
        const char *path_without_prefix = path + args->baselen;
        unsigned int creator_version = 0;
        unsigned int version_needed = 10;
        size_t zip_dir_extra_size = ZIP_EXTRA_MTIME_SIZE;
        size_t zip64_dir_extra_payload_size = 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, oid_to_hex(oid), path);
        }

        if (S_ISDIR(mode) || S_ISGITLINK(mode)) {
                method = ZIP_METHOD_STORE;
                attr2 = 16;
                out = NULL;
                compressed_size = 0;
        } else if (S_ISREG(mode) || S_ISLNK(mode)) {
                method = ZIP_METHOD_STORE;
                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 = ZIP_METHOD_DEFLATE;

                if (!buffer) {
                        enum object_type type;
                        stream = open_istream(args->repo, oid, &type, &size,
                                              NULL);
                        if (!stream)
                                return error(_("cannot stream blob %s"),
                                             oid_to_hex(oid));
                        flags |= ZIP_STREAM;
                        out = NULL;
                } else {
                        crc = crc32(crc, buffer, size);
                        is_binary = entry_is_binary(args->repo->index,
                                                    path_without_prefix,
                                                    buffer, size);
                        out = buffer;
                }
                compressed_size = (method == ZIP_METHOD_STORE) ? size : 0;
        } else {
                return error(_("unsupported file mode: 0%o (SHA1: %s)"), mode,
                                oid_to_hex(oid));
        }

        if (creator_version > max_creator_version)
                max_creator_version = creator_version;

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

        if (size > 0xffffffff || compressed_size > 0xffffffff)
                need_zip64_extra = 1;
        if (stream && size > 0x7fffffff)
                need_zip64_extra = 1;

        if (need_zip64_extra)
                version_needed = 45;

        copy_le32(header.magic, 0x04034b50);
        copy_le16(header.version, version_needed);
        copy_le16(header.flags, flags);
        copy_le16(header.compression_method, method);
        copy_le16(header.mtime, zip_time);
        copy_le16(header.mdate, zip_date);
        if (need_zip64_extra) {
                set_zip_header_data_desc(&header, 0xffffffff, 0xffffffff, crc);
                header_extra_size += ZIP64_EXTRA_SIZE;
        } else {
                set_zip_header_data_desc(&header, size, compressed_size, crc);
        }
        copy_le16(header.filename_length, pathlen);
        copy_le16(header.extra_length, header_extra_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 (need_zip64_extra) {
                copy_le16(extra64.magic, 0x0001);
                copy_le16(extra64.extra_size, ZIP64_EXTRA_PAYLOAD_SIZE);
                copy_le64(extra64.size, size);
                copy_le64(extra64.compressed_size, compressed_size);
                write_or_die(1, &extra64, ZIP64_EXTRA_SIZE);
                zip_offset += ZIP64_EXTRA_SIZE;
        }

        if (stream && method == ZIP_METHOD_STORE) {
                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(args->repo->index,
                                                            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);
        } else if (stream && method == ZIP_METHOD_DEFLATE) {
                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(args->repo->index,
                                                            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);
        } else if (compressed_size > 0) {
                write_or_die(1, out, compressed_size);
                zip_offset += compressed_size;
        }

        free(deflated);

        if (compressed_size > 0xffffffff || size > 0xffffffff ||
            offset > 0xffffffff) {
                if (compressed_size >= 0xffffffff)
                        zip64_dir_extra_payload_size += 8;
                if (size >= 0xffffffff)
                        zip64_dir_extra_payload_size += 8;
                if (offset >= 0xffffffff)
                        zip64_dir_extra_payload_size += 8;
                zip_dir_extra_size += 2 + 2 + zip64_dir_extra_payload_size;
        }

        strbuf_add_le(&zip_dir, 4, 0x02014b50); /* magic */
        strbuf_add_le(&zip_dir, 2, creator_version);
        strbuf_add_le(&zip_dir, 2, version_needed);
        strbuf_add_le(&zip_dir, 2, flags);
        strbuf_add_le(&zip_dir, 2, method);
        strbuf_add_le(&zip_dir, 2, zip_time);
        strbuf_add_le(&zip_dir, 2, zip_date);
        strbuf_add_le(&zip_dir, 4, crc);
        strbuf_add_le(&zip_dir, 4, clamp32(compressed_size));
        strbuf_add_le(&zip_dir, 4, clamp32(size));
        strbuf_add_le(&zip_dir, 2, pathlen);
        strbuf_add_le(&zip_dir, 2, zip_dir_extra_size);
        strbuf_add_le(&zip_dir, 2, 0);          /* comment length */
        strbuf_add_le(&zip_dir, 2, 0);          /* disk */
        strbuf_add_le(&zip_dir, 2, !is_binary);
        strbuf_add_le(&zip_dir, 4, attr2);
        strbuf_add_le(&zip_dir, 4, clamp32(offset));
        strbuf_add(&zip_dir, path, pathlen);
        strbuf_add(&zip_dir, &extra, ZIP_EXTRA_MTIME_SIZE);
        if (zip64_dir_extra_payload_size) {
                strbuf_add_le(&zip_dir, 2, 0x0001);     /* magic */
                strbuf_add_le(&zip_dir, 2, zip64_dir_extra_payload_size);
                if (size >= 0xffffffff)
                        strbuf_add_le(&zip_dir, 8, size);
                if (compressed_size >= 0xffffffff)
                        strbuf_add_le(&zip_dir, 8, compressed_size);
                if (offset >= 0xffffffff)
                        strbuf_add_le(&zip_dir, 8, offset);
        }
        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.len);
        copy_le64(trailer64.offset, zip_offset);

        copy_le32(locator64.magic, 0x07064b50);
        copy_le32(locator64.disk, 0);
        copy_le64(locator64.offset, zip_offset + zip_dir.len);
        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 struct object_id *oid)
{
        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.len);
        copy_le32_clamp(trailer.offset, zip_offset, &clamped);
        copy_le16(trailer.comment_length, oid ? the_hash_algo->hexsz : 0);

        write_or_die(1, zip_dir.buf, zip_dir.len);
        if (clamped)
                write_zip64_trailer();
        write_or_die(1, &trailer, ZIP_DIR_TRAILER_SIZE);
        if (oid)
                write_or_die(1, oid_to_hex(oid), the_hash_algo->hexsz);
}

static void dos_time(timestamp_t *timestamp, int *dos_date, int *dos_time)
{
        time_t time;
        struct tm tm;

        if (date_overflows(*timestamp))
                die(_("timestamp too large for this system: %"PRItime),
                    *timestamp);
        time = (time_t)*timestamp;
        localtime_r(&time, &tm);
        *timestamp = time;

        *dos_date = tm.tm_mday + (tm.tm_mon + 1) * 32 +
                    (tm.tm_year + 1900 - 1980) * 512;
        *dos_time = tm.tm_sec / 2 + tm.tm_min * 32 + tm.tm_hour * 2048;
}

static int archive_zip_config(const char *var, const char *value,
                              const struct config_context *ctx UNUSED,
                              void *data UNUSED)
{
        return userdiff_config(var, value);
}

static int write_zip_archive(const struct archiver *ar UNUSED,
                             struct archiver_args *args)
{
        int err;

        git_config(archive_zip_config, NULL);

        dos_time(&args->time, &zip_date, &zip_time);

        strbuf_init(&zip_dir, 0);

        err = write_archive_entries(args, write_zip_entry);
        if (!err)
                write_zip_trailer(args->commit_oid);

        strbuf_release(&zip_dir);

        return err;
}

static struct archiver zip_archiver = {
        .name = "zip",
        .write_archive = write_zip_archive,
        .flags = ARCHIVER_WANT_COMPRESSION_LEVELS|ARCHIVER_REMOTE,
};

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