compress_zip.c

/*
 * CDDL HEADER START
 *
 * This file and its contents are supplied under the terms of the
 * Common Development and Distribution License ("CDDL"), version 1.0.
 * You may only use this file in accordance with the terms of version
 * 1.0 of the CDDL.
 *
 * A full copy of the text of the CDDL should have accompanied this
 * source.  A copy of the CDDL is also available via the Internet at
 * http://www.illumos.org/license/CDDL.
 *
 * CDDL HEADER END
*/
/*
 * Copyright 2018 Saso Kiselkov. All rights reserved.
 */
 
#include <string.h>
 
#include "acfutils/assert.h"
#include "acfutils/compress.h"
#include "acfutils/helpers.h"
#include "acfutils/safe_alloc.h"
 
#include "zip/zip.h"
 
typedef struct {
    void        *buf;
    size_t      len;
} outbuf_t;
 
static size_t
read_cb(void *arg, uint64_t offset, const void *data, size_t size)
{
    ASSERT(arg != NULL);
    outbuf_t *buf = arg;
    UNUSED(offset);
    ASSERT(data != NULL || size != 0);
 
    buf->buf = safe_realloc(buf->buf, buf->len + size);
    memcpy(buf->buf + buf->len, data, size);
    buf->len += size;
 
    return (size);
}
 
void *
decompress_zip(void *in_buf, size_t len, size_t *out_len)
{
    ASSERT(in_buf != NULL || len == 0);
    ASSERT(out_len != NULL);
    *out_len = 0;
    if (len == 0) {
        return (NULL);
    }
 
    struct zip_t *zip = zip_stream_open(in_buf, len, 0, 'r');
    if (zip == NULL) {
        return (NULL);
    }
    if (zip_entries_total(zip) <= 0) {
        goto errout;
    }
    outbuf_t buf = {};
    if (zip_entry_extract(zip, read_cb, &buf) != 0) {
        goto errout;
    }
    zip_stream_close(zip);
 
    *out_len = buf.len;
    return (buf.buf);
 
errout:
    zip_stream_close(zip);
    if (buf.buf != NULL) {
        free(buf.buf);
    }
    return (NULL);
}