/*
* Copyright (c) 2014 Martin Decky
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
// XXX: This file is a duplicate of the same in uspace/lib/compress
#include <stdint.h>
#include <stddef.h>
#include <errno.h>
#include <mem.h>
#include <byteorder.h>
#include <gzip.h>
#include <inflate.h>
#define GZIP_ID1 UINT8_C(0x1f)
#define GZIP_ID2 UINT8_C(0x8b)
#define GZIP_METHOD_DEFLATE UINT8_C(0x08)
#define GZIP_FLAGS_MASK UINT8_C(0x1f)
#define GZIP_FLAG_FHCRC UINT8_C(1 << 1)
#define GZIP_FLAG_FEXTRA UINT8_C(1 << 2)
#define GZIP_FLAG_FNAME UINT8_C(1 << 3)
#define GZIP_FLAG_FCOMMENT UINT8_C(1 << 4)
typedef struct {
uint8_t id1;
uint8_t id2;
uint8_t method;
uint8_t flags;
uint32_t mtime;
uint8_t extra_flags;
uint8_t os;
} __attribute__((packed)) gzip_header_t;
typedef struct {
uint32_t crc32;
uint32_t size;
} __attribute__((packed)) gzip_footer_t;
/** Check GZIP signature
*
* Checks whether the source buffer start with a GZIP signature.
*
* @param[in] src Source data buffer.
* @param[in] srclen Source buffer size (bytes).
*
* @return True if GZIP signature found.
* @return False if no GZIP signature found.
*
*/
bool gzip_check(const void *src, size_t srclen)
{
if ((srclen < (sizeof(gzip_header_t) + sizeof(gzip_footer_t))))
return false;
gzip_header_t header;
memcpy(&header, src, sizeof(header));
if ((header.id1 != GZIP_ID1) ||
(header.id2 != GZIP_ID2) ||
(header.method != GZIP_METHOD_DEFLATE) ||
((header.flags & (~GZIP_FLAGS_MASK)) != 0))
return false;
return true;
}
/** Get uncompressed size
*
* Note that the uncompressed size is read from the GZIP footer
* (and not calculated by acutally decompressing the GZip archive).
* Thus the source of the GZip archive needs to be trusted.
*
* @param[in] src Source data buffer.
* @param[out] srclen Source buffer size (bytes).
*
* @return Uncompressed size.
*
*/
size_t gzip_size(const void *src, size_t srclen)
{
if (!gzip_check(src, srclen))
return 0;
gzip_footer_t footer;
memcpy(&footer, src + srclen - sizeof(footer), sizeof(footer));
return uint32_t_le2host(footer.size);
}
/** Expand GZIP compressed data
*
* The routine compares the output buffer size with
* the size encoded in the input stream. This
* effectively limits the size of the uncompressed
* data to 4 GiB (expanding input streams that actually
* encode more data will always fail).
*
* So far, no CRC is perfomed.
*
* @param[in] src Source data buffer.
* @param[in] srclen Source buffer size (bytes).
* @param[out] dest Destination data buffer.
* @param[out] destlen Destination buffer size (bytes).
*
* @return EOK on success.
* @return ENOENT on distance too large.
* @return EINVAL on invalid Huffman code, invalid deflate data,
* invalid compression method or invalid stream.
* @return ELIMIT on input buffer overrun.
* @return ENOMEM on output buffer overrun.
*
*/
int gzip_expand(const void *src, size_t srclen, void *dest, size_t destlen)
{
if (!gzip_check(src, srclen))
return EINVAL;
/* Decode header and footer */
gzip_header_t header;
memcpy(&header, src, sizeof(header));
gzip_footer_t footer;
memcpy(&footer, src + srclen - sizeof(footer), sizeof(footer));
if (destlen != uint32_t_le2host(footer.size))
return EINVAL;
/* Ignore extra metadata */
const void *stream = src + sizeof(header);
size_t stream_length = srclen - sizeof(header) - sizeof(footer);
if ((header.flags & GZIP_FLAG_FEXTRA) != 0) {
uint16_t extra_length;
if (stream_length < sizeof(extra_length))
return EINVAL;
memcpy(&extra_length, stream, sizeof(extra_length));
stream += sizeof(extra_length);
stream_length -= sizeof(extra_length);
if (stream_length < extra_length)
return EINVAL;
stream += extra_length;
stream_length -= extra_length;
}
if ((header.flags & GZIP_FLAG_FNAME) != 0) {
while (*((uint8_t *) stream) != 0) {
if (stream_length == 0)
return EINVAL;
stream++;
stream_length--;
}
if (stream_length == 0)
return EINVAL;
stream++;
stream_length--;
}
if ((header.flags & GZIP_FLAG_FCOMMENT) != 0) {
while (*((uint8_t *) stream) != 0) {
if (stream_length == 0)
return EINVAL;
stream++;
stream_length--;
}
if (stream_length == 0)
return EINVAL;
stream++;
stream_length--;
}
if ((header.flags & GZIP_FLAG_FHCRC) != 0) {
if (stream_length < 2)
return EINVAL;
stream += 2;
stream_length -= 2;
}
/* Inflate the data */
return inflate(stream, stream_length, dest, destlen);
}